Clotting Factors, Vascular Hormones and Ischemic Disease

Alagozlu H, Bakici Z, Gultekin F, Yildirim B, Sezer H: Anticardiolipin antibody positivity in diabetic patients with and without diabetic foot. J Diabetes Complications 16(2):172-5, 2002. Anticardiolipin (aCL) antibodies may play a role in the enhancement of platelet aggregation and/or progression of the macrovascular diabetic complications. Also, aCL antibodies may cause or promote ischemia and thrombosis. Therefore, we aimed to investigate IgG aCL and IgM aCL antibodies positivity in type 2 diabetic patients with and without ischemic diabetic foot. In this case-control study, we examined 40 diabetic patients without diabetic foot problem and 35 diabetic patients with ischemic diabetic foot. Forty diabetic patients (19 females, 21 males) without diabetic foot served as Group 1 and 35 diabetic patients (17 females, 18 males) who had ischemic diabetic foot served as Group 2. In the control group, 35 nondiabetic healthy subjects (18 females, 17 males) were included in Group 3. The groups were similar in age and sex, which is not statistically significant (P>.05). There was no difference in the IgG aCL antibodies positivity between Groups 1 and 3 (P>.05). However, IgG aCL antibodies positivity in Group 2 was significantly higher than those of the other groups (P<.05). IgG aCL antibodies were found positive in 10% (4/40) of Group 1, 34.3% (12/35) of Group 2 and 8.6% (3/35) of Group 3. When Groups 1 and 2 were compared, the odds ratio adjusted for age, gender, hypertension, coronary artery disease history, cigarette smoking, duration of diabetes mellitus, cholesterol, and haemoglobin A(1C) (HbA1c) was 6.8 [95% confidence interval (CI), 1.41-32.66; P=.016] for aCL positivity. In conclusion, although available evidence does not prove a causal association between positivity of aCL and diabetic foot, we believe that a causal association is supported by the data obtained from this study. Comments: Anticardiolipin antibodies (G and M) are found in sera of some patients with SLE and are associated clinically with spontaneous abortion, placental infarction, and thrombotic episodes. In the laboratory, they are frequently associated with the lupus anticoagulant, another antiphospholipid antibody. These antibodies are commonly meassured in patients with PVD when there is no obvious explanation for the clinical picture. They are not commonly measured in patients with diabetes.

Albertini J-P, Valensi P, Lormeau B, Aurousseau M-H, Ferriere F, Attali J-R, Gattegno L: Elevated concentrations of soluble E-selectin and vascular cell adhesion Molecule-1 in NIDDM. Effect of intensive insulin treatment. Diabetes Care 21: 1008-1013, 1998. Authors' conclusions: In poorly controlled NIDDM patients, sE-selectin levels are increased and fall to normal after short-term improvement of glycemia control. This suggests that assaying sE-selectin makes it possible to detect endothelium activation and to follow its reversal with euglycemia. Comments: E-selectin is one of the adhesion molecules that may play a role in the development of atherosclerosis and may stabilize the adhesion of leukocytes to endothelium and be involved in cellular interactions within the tissues. Physicians who practice tight control of diabetes will be pleased to note its normalization with glycemic control.

Back N et al: Fibrinolytic studies with biguanide derivatives. Ann NY Acad Sci 148:691, 1969. The authors noted an increase in fibrinolysis in animals chronically treated with phenformin and suggest a possible role for phenformin in the prophylaxis and treatment of thromboembolic disease. Comment: The use of biguanides as fibrinolytic agents seems to have been lost in the recent decades. Case 135 in our case studies provides an illustration where both phenformin and metformin appeared to be quite helpful. The combination of phenformin and ethylestrenol has been shown to increase the level of plasminogen activator in the blood, making it truly a fibrinolytic combination (Fearnley GR et al. Lancet 1:723, 1971). The same combination increases the serum concentration of fibrin breakdown products in patients with occlusive vascular disease or rheumatoid arthritis (Fearnley GR et al. Lancet 1:910, 1969). In diabetics, phenformin has been shown to return lysis time to normal when it was pathologically increased (Fiaschi E. Et al. Arzneimittelforschung 19:638, 1969); such was also the result in our case 135 in whom both biguanides or booting improved clot lysis. Again, the fibrinolytic action of phenformin was reported to be beneficial in a patient with recurrent pulmonary emboli and refractory deep vein thromboses and leg ulcers (Lancet 1: 1239, 1969). If the euglobulin lysis time were more commonly available, the clinician might use it to find diabetic patients with occlusive vascular disease and prolonged lysis times; they might be expected to benefit from biguanide therapy.

Benedict CR, Mueller S, Anderson HV and Willerson JT: Thrombolytic therapy: a state of the art review. Hosp Practice p61-72, June 15, 1992. A good review. In briefly discussing peripheral arterial ischemia, the authors note the presence of a lysable clot of as long as 12 months in the iliac arteries, 6 months in the superficial femorals and one month in the crural arteries. &Quot; Pooled results of several studies of locally infused thrombolytic therapy showed a 67% success rate with streptokinase, 81% with urokinase and 90% with t-PA in lysing such thrombus and restoring blood flow. Major complications were reported in 19%, 12% and 9% of patients respectively. Comment: Boot therapy presumably stimulates local fibrinolytic activity possibly explaining the success of boot therapy in some patients in restoring blood flow. We have in some difficult patients successfully combined boot therapy with streptokinase infusions but have made no organized study of the benefit of such combined therapy.

Bhatnagar PK, Ierardi RP, Ikeda Y, Wada H, Wilson A, Khoury P, Karamonte C, Kerstein M and Matsumoto T: The impact of thrombolytic therapy on arterial and graft occlusions: A critical analysis. J Cardiovasc Surg 37: 105-12, 1996. Summary: Study design. A retrospective review of 55 patients undergoing 55 lytic treatments with high dose urokinase from February 1989 to February 1993 was performed. The cases were divided into three groups: Group I: successful thrombolysis with residual defects followed by surgical reconstruction or percutaneous transluminal angioplasty (PTA); Group II: successful thrombolysis alone; and Group III: failure of thrombolysis requiring reconstruction or leading to amputation. No effort was made to analyze the particular type of reconstruction. Follow-up ranged from 1 to 1627 days (4 yrs and 5.5 mos). Results: One, two and three year patency rates were 47%, 24% and 8% for Group I; 57%, 46% and 46% for Group II; and 24%, 10% and 10% for Group III respectively. The one, two and three year limb salvage rates were 92%, 76%, and 76% for Group I; 82%, 82% and 82% for Group II; and 48%, 37% and 37% for Group III respectively. Forty-one complications occurred in 35 of the 81 (43%) lytic treatments. Conclusions: Intraarterial thrombolytic therapy can be regarded as a possible consideration in the initial management of acute lower extremity arterial and synthetic graft occlusions especially in patients with multiple prior vascular reconstructions. Unsuccessful thrombolysis results in a poor outcome despite surgical reconstruction in the majority of cases.

Boykin Jr JV, Kalns JE, Shawler LG, Sommer VL and Crossland MC: Diabetes-impaired wound healing predicted by urinary nitrate assay: A preliminary, retrospective study. Wounds 11(3): 62-69, 1999. Abstract: Diabetic wound healing is occasionally impaired and associated with chronic ulceration and lower extremity amputation (LEA). Topically applied platelet-derived growth factor (rhPDGF-BB) increases healing in less than 50% of these cases suggesting that other factors are involved. In a preliminary, retrospective study of diabetic ulcer patients receiving rhPDGF-BB (becaplermin*), we show that urinary concentrations of nitric oxide (NO) metabolite nitrate are significantly reduced (p<0.05) in patients with poor or absent ulcer healing as compared to patients with healed ulcers or non-diabetic controls. This suggests that significantly decreased endogenous NO production predicts diabetic wound outcomes in patients treated with becaplermin. These preliminary findings also appear to support further investigations of the clinical use of urinary nitrate levels as a tool to guide therapy during treatment of diabetic ulcers. * Regranex, Ortho-McNeil Pharm. Comments: Nitric oxide, of course, can be generated in many tissues in the body of the diabetic patient besides that of the wound. The significance of the urinary level of nitrate, hence, is as likely to reflect systemic disease as disease local to the wound. In their discussion, Boykin et al list an impressive number of roles for NO in wound healing: promotion of angiogenesis and cellular migration, increased wound collagen deposition and collagen cross-linking, promotion of vasodilatation, inhibition of platelet aggregation and endothelial-leukocyte adhesions, modulation of endothelial proliferation and apoptosis, increase in the viability of random cutaneous flaps, and enhancement of cellular immunomodulation and bacterial cytotoxicity. Nitric oxide, of course, is generated also by acetylcholine and, we presume, by cholinergic agonists. It is for this reason, we add urecholine commonly to our Mini-Boot bath or inject it locally into neuropathic wounds (see Dillon, Angiology 1991 in our Neuropathy library). Morgan et al (below) think pneumatic boots may also increase nitric oxide.

Buchan KW, Hassall DG: PPAR agonists as direct modulators of the vessel wall in cardiovascular disease. Med Res Rev 20(5):350-66, 2000. Successful management of cardiovascular (CV) disease and associated metabolic syndromes, such as diabetes, is a major challenge to the clinician. Reducing CV risk factors, such as abnormal lipid profiles, insulin resistance or hypertension is the foundation of such therapy. A relatively new class of therapeutic agent, activators of peroxisome proliferator-activated receptors (PPAR), is poised to make a major impact with regard to several areas of risk factor management. However, there is growing evidence that PPAR agonists may also influence the CV system directly by modulating vessel wall function. These observations suggest that additional benefit, in the treatment of CV disease, may derive not only from the ability of agents to modify risk factors but also to influence directly the cellular mechanisms of disease within the vessel wall. A precedent for this dual action comes from examination of the effects of inhibitors of HMG CoA reductase (statins), where risk factor modulation is accompanied by direct actions on the vessel wall. In this review, we summarize the evidence suggesting that PPAR agonists may directly modulate vessel wall function, and that these may parallel those effects reported recently for the statins.

Cees JJ, Smits P, Willemsen JJ, Lenders JWM, Thien T and Lutterman JA: Effects of insulin on vascular tone and sympathetic nervous system in NIDDM. Diabetes 45:15-22, 1996. The authors conclude, "Therefore, because of daily life hyperinsulinemia, chronic sympathetic stimulation could be operative in these patients and may explain the increased incidence of hypertension and/or cardiovascular complications". Comments: These authors compared 12 "lean" normotensive subjects with well-controlled NIDDM with 13 matched controls. Like all of the literature describing studies in lean NIDDM subjects, these subjects were described as lean because their body mass index was under 27 kg/m2 . They found these lean NIDDM patients among 700 in their outpatient department and among 50 candidates from their general practitioners; lean NIDDM patients obviously were not common. It is possible that they do not exist. If one takes patients at age 20 who are in the lower 5-20% weight category for their height and allows them to gain 20-30% in weight in the next 20-30 years, most will also have a BMI under 27 and be classified at normal weight. Now, the Metropolitan 1959 blood pressure study pointed out in their massive data that such weight gain is detrimental. Such weight gain in lean-framed individuals is harmful. Indeed, such individuals should be labeled as obese. If one accepts this principle, then virtually all of the hyperinsulinemia data is in error. Hyperinsulinemia becomes merely a marker for obesity. For more discussion on these points see the comments following the article by Facchini et al below.

Chae JK, Kim I, Lim ST, Chung MJ, Kim WH, Kim HG, Ko JK, Koh GY: Coadministration of angiopoietin-1 and vascular endothelial growth factor enhances collateral vascularization. Arterioscler Thromb Vasc Biol 20:2573-8, 2000. National Creative Research Initiatives Center for Cardiac Regeneration and Institute of Cardiovascular Research (J.K.C., I.K., H.G.K, J.K.K., G.Y.K.) and the Departments of Nuclear Medicine (S.T. L), Pathology (M.J.C), and Internal Medicine -Using growth factors to induce vasculogenesis is a promising approach in the treatment of ischemic legs and myocardium. Because the vasculogenesis requires a cascade of growth factors, their receptors, and intracellular signals, such therapies may require the application of more than a single growth factor. We examined the effect of 2 endothelial cell-specific growth factors, angiopoietin-1 (Ang1) and vascular endothelial growth factor (VEGF), on primary cultured porcine coronary artery endothelial cells. VEGF, but not Ang1, increased DNA synthesis and cell number. Ang1 or VEGF induced migration and sprouting activity, increased plasmin and matrix metalloproteinase-2 secretion, and decreased tissue inhibitors of metalloproteinase type 2 secretion. A combination of the submaximal doses of Ang1 and VEGF enhanced these effects and was more potent than the maximal dose of either alone. In a rabbit ischemic hindlimb model, a combination of Ang1 and VEGF gene delivery produced an enhanced effect on resting and maximal blood flow and capillary formation that was greater than that of either factor alone. Angiographic analyses revealed that larger blood vessels were formed after gene delivery of Ang1 or Ang1 plus VEGF than after VEGF gene delivery. These results suggest that combined treatment of Ang1 and VEGF could be used to produce therapeutic vascularization.

Chang CH, Yu HS, Wang MT, Ko SS: Study on blackfoot disease: with special reference to evaluating its cutaneous microcirculatory status. Kao-Hsiung I Hsueh Ko Hsueh Tsa Chih (Kaohsiung J of Medical Sciences) 9 (10): 559-66, 1993. Abstract: We evaluated the microcirculatory status of blackfoot disease by skin temperature measurement, laser Doppler flowmetry and capillary microscopy. The results of these assessments revealed a good correlation between the disease stage and the microcirculatory status. No effective therapy other than surgical amputation was recommended before. In this study, we treated this endemic disease with prostaglandin E1 (PGE1) infusion therapy. PGE1 was most effective in the erythematous stage and some minor ulcer with an improvement of microcirculatory status. However, PGE1 had no effect in severe ulcerative (ulcer >0.5 cm) and gangrenous stages. These microcirculatory improvements foreshadowed the improvement of clinical manifestations. The microcirculatory status after PGE1 treatment demonstrated the effectiveness of the therapy. Comments: Like the reader, we also have only the abstract here. And if the article was written in Chinese, the full article will not help us. This article was included because of their reported experience with PGE1 infusions, which seemed most effective to them in pre-ulcerative disease. The latter, of course, may include a broad spectrum from normal to pre-gangrene. They found PGE1 no help in patients with ulcers over 0.5 cm. It would appear that PGE1, hence, would not benefit most of our "boot patients" who seem to be referred only if their ulcers are quite large.

Cho YP, Lee DH, Jang HJ, Kim JS, Han MS, Lee SG: Peripheral arterial insufficiency associated with protein C deficiency. British Journal of Radiology 75 :843-846, 2002. Abstract: Two patients with protein C deficiency who presented with peripheral arterial insufficiency were successfully managed. One patient was managed with bypass surgery for focal gangrene followed by full anticoagulation whilst the other patient was managed with full anticoagulation. Both patients showed characteristic arteriographic findings. Patients who present with peripheral arterial insufficiency demonstrating thrombotic occlusion of main peripheral artery without atherosclerosis and other risk factors should be evaluated for hypercoagulable states.Comments: This paper points to the common sense fact that is often lost: if things do not appear to be typical, consider other possibilities. Regarding boot therapy in these cases, it is all right to pump on arterial thrombi in an attempt to break them up... but care must be taken to rule out the presence of large deep vein thrombi.

Christen Y, Wutschert R, Weimer D, de Moerloose P, Kruithof EK, Bounameaux H: Effects of intermittent pneumatic compression on venous haemodynamics and fibrinolytic activity. Blood Coagul Fibrinolysis 3:185-90, 1997. Pneumatic intermittent compression is an effective method to prevent postoperative venous thromboembolism. Its efficacy has been ascribed to both a haemodynamic action (increase of blood flow velocity) and a stimulation of endogenous fibrinolytic activity [via the production of tissue-type plasminogen activator (t-PA) by the vascular endothelium]. The relative contribution of these two effects is still debated. In a randomized, cross-over study in ten healthy volunteers, we compared the haemodynamic and fibrinolytic effects of two different pneumatic intermittent compression devices: a classical, low-pressure, whole-leg boots system, and a novel, high-pressure, plantar compression system. The study was performed at rest, to compare haemodynamics and fibrinolytic activity modifications, and under induced venous leg stasis, in order to compare the two compression systems in experimental conditions mimicking laparoscopic surgery. Our data show that (1) a pneumatic compression device that exerts its compression on the plantar venous plexus only induced an increase of venous blood peak velocity and flow in the common femoral vein that is very similar to that induced by the classical whole-leg boots compression system; (2) the venous stasis induced by an external pressure mimicking the conditions of laparoscopic surgery further increased the absolute velocity and flow increase, with the two intermittent compression systems tested; (3) no changes of t-PA or plasminogen activator-inhibitor 1 antigens were observed with either pneumatic compression device. In conclusion, the present study indicates that the antithrombotic effect of mechanical prophylaxis is probably mainly due to its ability to increase venous peak velocity and flow, especially under venous stasis conditions.

Comerota AJ, Chouhan V, Harada RN, Sun L, Hosking J, Veermansunemi R, Comerota AJ Jr, Schlappy D, Rao AK: The fibrinolytic effects of intermittent pneumatic compression: mechanism of enhanced fibrinolysis. Ann Surg 226:306-13, 1997. Abstract: BACKGROUND AND OBJECTIVES: Intermittent pneumatic compression (IPC) is an effective form of deep vein thrombosis prophylaxis for general surgery patients. The antithrombotic effect of IPC is thought to be the result of increased venous velocity and stimulation of endogenous fibrinolysis. However, the mechanism of enhanced fibrinolytic activity and the relative effects on normal and postthrombotic veins have not been defined. The purposes of this study are 1) to quantify changes in fibrinolytic activity with IPC; 2) to study the mechanism of fibrinolytic enhancement with IPC; and 3) to evaluate whether postthrombotic patients have the same capacity for fibrinolytic enhancement with IPC as do normal subjects. METHODS: Twelve volunteers (6 normal and 6 postthrombotic) had 5 IPC devices applied for 120 minutes in random fashion, 1 per week x 5 weeks. The devices included single-chamber, sequential, foot, calf, and long-leg compression. Subjects had an indwelling antecubital venous cannula placed for blood drawn at baseline, 60, 120, and 180 minutes after IPC devices were applied. Global fibrinolytic activity (euglobulin fraction, fibrin plate assay), tissue plasminogen activator (tPA) antigen (Ag) and activity (Act), plasminogen activator inhibitor-1 (PAI-1) Ag and Act, alpha-2-antiplasmin-plasmin complexes, and von Willebrand factor (vWF) antigen were assayed. RESULTS: A striking elevation in fibrinolytic activity was noted at 180 minutes with all devices in normal subjects and postthrombotic patients (p = 0.01-0.0001); however, baseline and stimulated fibrinolytic activity was attenuated in postthrombotic patients (<0.03). The tPA-Act increased only in normal subjects (3.8 +/- 1.9%) (p = 0.057), despite a decrease in plasma tPA-Ag, which was observed in both normal subjects (-12.4 +/- 3.8%) (p = 0.009) and patients (-17.2 +/- 3.1%) (p = 0.001). PAI-1-Ag decreased in both normal subjects (-13.4 +/- 3.8%) (p = 0.007) and patients (-12.0 +/- 3.1%) (p = 0.013) with a marked reduction in PAI-1-Act in both normal subjects (p = 0.003) and patients (p = 0.004). There were no changes in vWF, and alpha-2-antiplasmin-plasmin complexes increased only in postthrombotic patients (p = 0.021). CONCLUSIONS: Stimulation of endogenous fibrinolytic activity occurs after IPC, both in normal subjects and postthrombotic patients; however, baseline and overall fibrinolytic response in postthrombotic patients is reduced. The mechanism of increased fibrinolytic activity is likely because of a reduction in PAI-1, with a resulting increase of tPA activity.

Conchonnet Ph, Mismetti P, Reynaud J, Laporte-Simitsidis S, Tardy-Poncet B, Boissier C, Rambaud C and Decousus H: Fibrinolysis and elastic compression; no fibrinolytic effect of elastic compression in healthy volunteers. Blood Coagulation and Fibrinolysis 5: 949-953, 1994. While pneumatic boot therapies do have a profibrinolytic effect and a platelet anti-aggregant action in the literature, here the application of Biflex elastic bandages for 24 hours at a pressure of 35mm Hg had no effect on the euglobulin lysis time or other various factors in healthy volunteers. Comment: Compression stockings and intermittent pneumatic booting differ in their effects on fibrinolysis.

Dai G, Tsukurov O, Orkin RW, Abbott WM, Kamm RD, Gertler JP: An in vitro cell culture system to study the influence of external pneumatic compression on endothelial function. J Vasc Surg 32:977-87, 2000. PURPOSE: External pneumatic compression (EPC) is an effective means of prophylaxis against deep venous thrombosis. However, its mechanism remains poorly understood. Understanding of the biological consequences of EPC is an important goal for optimizing performance of the EPC-generating device and providing guidance for clinical use. We present a new in vitro cell culture system (Venous Flow Simulator) that simulates blood flow and vessel collapse conditions during EPC, and we examine the influence of these factors on endothelial cell (EC) fibrinolytic activity and vasomotor function. METHODS: An in vitro cell culture system was designed to replicate the hemodynamic shear stress and vessel wall strain associated with induced blood flow during different modes of EPC. Human umbilical vein endothelial cells were cultured in the system and subjected to intermittent flow, vessel collapse, or a combination of the two. The biologic response was assessed through changes in EC morphology and the expression of fibrinolytic factors tissue plasminogen activator, plasminogen activator inhibitor type 1, profibrinolytic receptor (annexin II), and vasomotor factors endothelial nitric oxide synthase and endothelin-1. RESULTS: The cells remained attached and viable after being subjected to intermittent pulsatile flow (F) and tube compression (C). In F and F + C, cells aligned in the direction of flow after 6 hours. Northern blot analysis of messenger RNA shows that there is an upregulation of tissue plasminogen activator expression (1.95 +/- 0.19 in F and 2.45 +/- 0.46 in FC) and endothelial nitric oxide synthase expression (2.08 +/- 0.25 in F and 2.11 +/- 0.21 in FC). Plasminogen activator inhibitor type 1, annexin II, and endothelin 1 show no significant change under any experimental conditions. The results also show that pulsatile flow, more than vessel compression, influences EC morphology and function. CONCLUSION: Effects on ECs of intermittent flow and vessel collapse, either individually or simultaneously, were simulated with an in vitro system of new design. Initial results show that intermittent flow associated with EPC upregulates EC fibrinolytic potential and influences factors altering vasomotor tone. The system will facilitate future studies of EC function during EPC.

Facchini FS, Hua N, Abbasi F, Reaven GM: Insulin resistance as a predictor of age-related diseases. J Clin Endocrinol Metab 86(8):3574-3578, 2001. Departments of Medicine (F.S.F., N.H., F.A., G.M.R.), Stanford University, School of Medicine Stanford, California 94305. The current study was initiated to evaluate the ability of insulin resistance to predict a variety of age-related diseases. Baseline measurements of insulin resistance and related variables were made between 1988-1995 in 208 apparently healthy, nonobese (body mass index < 30 kg/m(2)) individuals, who were then evaluated 4-11 yr later (mean +/- SEM = 6.3 +/- 0.2 yr) for the appearance of the following age-related diseases: hypertension, coronary heart disease, stroke, cancer, and type 2 diabetes. The effect of insulin resistance on the development of clinical events was evaluated by dividing the study group into tertiles of insulin resistance at baseline and comparing the events in these 3 groups. Clinical endpoints (n = 40) were identified in 37 individuals (18%) of those evaluated, including 12 with hypertension, 3 with hypertension + type 2 diabetes, 9 with cancer, 7 with coronary heart disease, 4 with stroke, and 2 with type 2 diabetes. Twenty-eight out of the total 40 clinical events were seen in 25 individuals (36%) in the most insulin-resistant tertile, with the other 12 occurring in the group with an intermediate degree of insulin resistance. Furthermore, insulin resistance was an independent predictor of all clinical events, using both multiple logistic regression and Cox's proportional hazards analysis. The fact that an age-related clinical event developed in approximately 1 out of 3 healthy individuals in the upper tertile of insulin resistance at baseline, followed for an average of 6 yr, whereas no clinical events were observed in the most insulin-sensitive tertile, should serve as a strong stimulus to further efforts to define the role of insulin resistance in the genesis of age-related diseases. Comments: The concept of insulin resistance independent of obesity as an important clinical entity has always bothered some. First, it is to be appreciated that the concentraton of insulin rises in the serum with increasing body fat:

Bagdade JD et al: The significance of basal insulin levels in the evaluation of the insulin response to glucose in diabetic and nondiabetic subjects. J Clin Invest 46:1549, 1967. An example of hyperinsulinemia in a non-obese person? Patients with lipoatrophic diabetes are extremely insulin-resistant; in the absence of fat cells they have a significant reduction in sites to store fuel and are slow to clear their blood after meals. Insulin resistance is seen, thus, if the fat cell is stuffed (obesity) or absent (lipoatrophy).

Next, the elevation of the BMI the above authors use as a dividing line between normal weight and obesity is to be noted. For comparison, I have modified the data from the 1959 Build and Blood Pressure Study:

Princeton University Varsity wrestling team 1952-1953. From right to left are shown the coach, the 123 pounder, the 130 pounder (70 inches tall), the 137, 147, 157, 167 pounders, the heavy-weight (70 inches tall) and 177 pounder. The wrestlers have little extra fat. Their heights differ little from the 130 pounder to the heavyweight in spite of an increase in weight of 60% between the 130 pounder and the heavyweight. The heavyweight was national intercollegiate wrestling champion and an All-American football player on Princeton's nationally rated undefeated 1952 football team. Note that he is shorter than the 177 pounder and the same height as the 130 pounder. Without his weight training after graduation, he found himself getting obese. He began an aerobic exercise and diet program and returned several years later to his college reunion weighing 165 lbs. The 130 pounder also returned weighing 165 pounds. The latter developed hyperlipidemia, which he successfully treated with weight reduction down to 150 pounds. Both had the same BMI at reunions. Who would consider them similar individuals? Or will the reader allow that these wrestlers differed considerably in body frame?

As wrestlers train and diet to make weight classes, are they a special class irrevelant to the general population? Perhaps, more relevant is the report by Paris et al (diabetes Care 24:1894-1898, 2001) on the characteristics of U.S. Military personnel at entry who develop type 2 diabetes. They found that the incidence of diabetes increased 3-fold for persons with a BMI >=30 and two-fold for those with BMI's between 25.0 and 29.9. Again, the propriety of considering a BMI value as high as 30 as a dividing line between normal and obese persons may be examined further in considering mortality data. The following graph is reproduced from Sjostrom in "Obesity, Theory and Therapy", second edition, ed. by Stunkard and Wadden, Raven Press, NY, 1993, p13.

Fernandez-Real JM, Broch M, Vendrell J, Ricart W: Insulin resistance, inflammation, and serum fatty acid composition.Diabetes Care 26:1362-8, 2003. OBJECTIVE: Fatty acids (FAs) have been involved in the development of chronic inflammatory conditions such as insulin resistance and obesity. However, the relation among insulin resistance, obesity, inflammatory activity (circulating interleukin [IL]-6) and dietary FAs has been scarcely studied in otherwise healthy subjects. RESEARCH DESIGN AND METHODS: We aimed to study these interactions in 123 overweight (BMI 26.9 +/- 2.4 kg/m(2) [means +/- SD]) subjects and 109 lean (BMI 21.7 +/- 1.7 kg/m(2), P < 0.000001) subjects. IL-6 was measured by immunoassay and FA by gas liquid cromatography. RESULTS: The percentage of saturated FAs (r = 0.30, P = 0.01) and omega-6 FAs (r = -0.32, P = 0.001) were significantly associated with circulating IL-6, whereas the percentage of omega-3 FAs correlated negatively with C-reactive protein in overweight subjects (P = 0.04). Saturated-to-omega-3 and saturated-to-omega-6 FA ratios were significantly and positively associated with C-reactive protein (P < 0.0001) and IL-6 (P < 0.001), respectively. In contrast, none of these associations reached statistical significance in lean subjects. Those subjects in the most insulin-sensitive quintile (homeostasis model assessment value) showed a significantly higher percentage of linoleic acid (C18:2 varpi6) (P = 0.03) and a significantly lower level of araquidic (C20:0) (P = 0.04), behenic (C22:0) (P = 0.009), lignoceric (C24:0) (P = 0.02), and nervonic (C24:1 varpi9) (P = 0.001) FAs than the remaining subjects. In parallel, the most insulin-sensitive subjects showed significantly decreased C-reactive protein (P = 0.03). Serum C-reactive protein was significantly associated with percent linoleic acid and eicosapentaenoic acid in nonsmoking men (P = 0.03 and P = 0.04, respectively) and with docosahexaenoic acid in nonsmoking women (r = -0.46, P < 0.0001). We constructed a multivariant regression analysis to predict circulating IL-6. Age, BMI, waist-to-hip ratio (WHR), smoking status, and the relation of saturated to omega-6 or saturated to omega-3 FAs were considered as independent variables separately in men and women. In overweight men, the ratio of saturated to omega-3 FAs (P = 0.01), but not age, sex, BMI, WHR, or smoking status, independently contributed to 17% of IL-6 variance. In lean men, smoking status (P = 0.02), but not the remaining variables, contributed to 8% of IL-6 variance. CONCLUSIONS: Dietary FAs (as inferred from plasma FA concentration) seem to be linked to inflammatory activity in overweight subjects and in subjects with insulin resistance. Being overweight modulates the relation of FAs to inflammatory markers.

Freeman BD, Buchman TG: Coagulation inhibitors in the treatment of sepsis. Expert Opin Investig Drugs11:69-74, 2002. Despite advances in supportive care, sepsis and septic shock continue to be major causes of morbidity and mortality in critically ill patients. The lack of efficacy of anti-inflammatory drugs in patients with sepsis has shifted interest toward developing alternative treatments. The observation that clotting system activation may in part underlie the physiological derangements of sepsis has resulted in efforts to target the clotting cascade as a therapeutic strategy. Anticoagulants have been shown to ameliorate physiological derangements and improve survival in animal sepsis models. Three agents have undergone extensive study in humans: recombinant human activated protein C (rhAPC, drotrecogin-alpha), antithrombin III (ATIII) and tissue factor pathway inhibitor (TFPI). While a recent Phase III study of rhAPC suggests a survival benefit in patients with sepsis, major concerns about this trial include the manner in which the study was conducted, the potential toxicity of rhAPC and the questionable efficacy of this agent in patients with low mortality risk. Further clinical testing of rhAPC appears to be necessary to better define the target population most appropriate for its use. In contrast, a large Phase III study of high dose ATIII in patients with sepsis failed to show a treatment benefit with this agent. Finally, while TFPI has undergone extensive preclinical and Phase II testing, the results of Phase III studies have not been published. In summary, while coagulation inhibitors may ultimately have a therapeutic role in selected subgroups of patients with sepsis, the efficacy and safety of this class of agents remain to be proven.

Galvan L:Effects of heparin on wound healing. J WOCN 23:224-6, 1966. Portions of abstract: ..." In cell culture studies, heparin and growth factors are associated with rapid and effective endothelial cell repair. In clinical studies, patients with burns and diabetic foot ulcers showed an increase in capillary circulation and deceased healing time. In contrast, heparin may not be beneficial in populations with ischemia, malnourishment, and vascular problems, although research in these populations is limited..." Comment: Actually, research data supporting the use of heparin in wound healing is scanty. Certainly, it would appear to have a role in patients in whom abnormal clotting is present. This article was added to help us keep an open mind.

Garcia-Unzueta MT, Montalban C, Pesquera C, Berrazueta JR, Amado JA: Plasma adrenomedullin levels in type 1 diabetes. Relationship with clinical parameters. Diabetes Care 21:999-1003, 1998. Authors' conclusions: Plasma adrenomedullin (AM) and cyclic-AMP are increased in type 1 diabetic patients with renal insufficiency. Creatinine clearance (CrClc) and duration of the disease are related to the plasma AM levels in these patients. Comment: Adrenomedullin gets its name from its initial site of discovery: a pheochromocytoma extract. It has a sequence homology to calcitonin gene-related peptide. The major source of circulating AM is likely the vascular endothelium where it may function as an autocrine vasorelaxing factor. The authors point out that plasma levels may be increased in essential hypertension, congestive heart failure, acute myocardial infarction, chronic renal failure, cirrhosis, and sepsis. This article is included to list another endothelial vascular factor for the reader. Its long term importance remains to be shown.

Gimbrone MA Jr,Topper JN,Nagel T,Anderson KR,Garcia-Cardena G: Endothelial dysfunction, hemodynamic forces, and atherogenesis. Ann N Y Acad Sci 902:230-9, 2000. Phenotypic modulation of endothelium to a dysfunctional state contributes to the pathogenesis of cardiovascular diseases such as atherosclerosis. The localization of atherosclerotic lesions to arterial geometries associated with disturbed flow patterns suggests an important role for local hemodynamic forces in atherogenesis. There is increasing evidence that the vascular endothelium, which is directly exposed to various fluid mechanical forces generated by pulsatile blood flow, can discriminate among these stimuli and transduce them into genetic regulatory events. At the level of individual genes, this regulation is accomplished via the binding of certain transcription factors, such as NF kappa B and Egr-1, to shear-stress response elements (SSREs) that are present in the promoters of biomechanically inducible genes. At the level of multiple genes, distinct patterns of up- and downregulation appear to be elicited by exposure to steady laminar shear stresses versus comparable levels of non-laminar (e.g., turbulent) shear stresses or cytokine stimulation (e.g., IL-1 beta). Certain genes upregulated by steady laminar shear stress stimulation (such as eNOS, COX-2, and Mn-SOD) support vasoprotective (i.e., anti-inflammatory, anti-thrombotic, anti-oxidant) functions in the endothelium. We hypothesize that the selective and sustained expression of these and related "atheroprotective genes" in the endothelial lining of lesion-protected areas represents a mechanism whereby hemodynamic forces can influence lesion formation and progression.

Griffith TM, Lewis MJ, Newby AC, Henderson AH: Endothelium derived relaxing factor. J Am College Cardiol 12:797-806, 1988. Abstract: This article reviews what is known of endothelium-derived relaxing factor and its possible physiologic and pathophysiologic roles. This relaxing factor is now thought to be nitric oxide or a ready source of it. It acts as an endogenous nitrovasodilator, stimulating soluble guanylate cyclase to increase cyclic guanosine monophosphate (GMP) levels in vascular smooth muscle and platelets, with consequent relaxant and anti-aggregatory effects (predominantly when stimulated through receptor-operated channels). Its actions are thus synergistic with those of cyclic adenosine monophosphate (AMP)-mediated stimulation (for example, adenosine, prostacyclin). Endothelium-derived relaxing factor is unstable and is thought to act only very locally in vivo. Its release is continuous in the basal state and is stimulated by a number of neuropeptides and by agents released during platelet activation and thrombosis--with large differences in activity among different vessels. Endothelium-derived relaxing factor activity is also flow related, thereby coordinating vasomotor behavior in an intact vascular tree in response to changes in flow. Endothelium-derived relaxing factor activity is reduced in several pathologic states, including atherosclerosis.

Gruden G, Cavallo-Perin P, Bazzan M, Stella S, Vuolo A: PA1-1 and factor VII activity are higher in IDDM patients with microalbuminuria. Diabetes 43426-29, 1994. Microalbuminuria is associated with an increased risk of cardiovasular disease. In this study, tissue plasminogen activator (t-PA), plasminogen activator inhibitor-1 (PA1-1), factor VII activity, plasma fibrinogen and endothelin-1 (ET-1) were measured in 13 IDDM patients with microalbumin excretion greater than 20ug/min and 13 with excretion less than 20 ug/min. ET-1 and t-PA were similar in the two groups while the other factors were higher in the patients with microalbuminuria: PA1-1 5.65+/-1.92vs0.85+/-0.58 IU/ml; factor VII 87.85+/-4.94vs 76.54+/-2.31%; fibrinogen 3.38+/-0.21 vs 2.65+/-0.13 g/L. Plasma fibrinogen was significantly related to the albumen excretion rate while triglycerides and factor VII were related to PA1-1. "These results suggest that microalbuminuria is associated with a hypercoagulative and hypofibrinolytic state. Hemostatic dysfunctions might be a pathogenetic link between microalbuminuria and CVD."

Guyton DP, Khayat A, Husni EA and Schreiber H: Elevated levels of 6-keto-prostaglandin-F1a from lower extremity during external pneumatic compression. Surg Gynecol Obstet 166: 338-342, 1988. Blood from one leg given pneumatic compression therapy was compared with blood from the other leg and one arm. The stable metabolite of prostacyclin (PGI2), 6-keto-prostaglandin-F1a, rose from 0.40+/-0.07ng/ml (untreated leg) to 0.71+/-0.13 (treated leg) by 60 minutes (P<0.005). "PGI2 is a vasodilator and a strong inhibitor of platelet aggregation and may be of importance in the antithrombotic functions of the intact endothelial lining."

Hanada T, Hashimoto M, Nosaka S et al: Shear stress enhances prostacyclin release from endocardial endothelial cells. Life Sci 66:215-20, 2000. The effect of shear stress on the release of prostacyclin (PGI2) from cultured endocardial endothelial cells (EECs) was investigated. EECs were harvested from the right ventricle (RV) and the left ventricle (LV) of porcine heart. Confluent EECs were incubated under various degrees of shear stress (0.2, 1, 4 and 6 dyne/cm2) and PGI2 release from each cell was measured. PGI2 release from LV-EECs and RV-EECs was enhanced by the elevation of shear stress in a shear-dependent manner with a rapid increase at the onset of flow; however, there was no significant difference in PGI2 production between RV-EECs and LV-EECs. production of PGI2 was significantly inhibited from cells exposed to 8-(dimetilamino) octyl 3,4,5-trymethoxybenzoate hydrochloride (10 and 100 microM: an inhibitor of intracellular calcium mobilization) or cyclopiazonic acid (10 microM: an endoplasmic reticulum Ca2+-ATPase inhibitor). These results indicate that shear stress enhances PGI2 release from cultured EECs and that mechanotransduction of shear stress depends on calcium mobilization in EECs.

He H, Venema VJ, Gu X, Venema RC, Marrero MB, Caldwell RB: Vascular endothelial growth factor signals endothelial cell production of nitric oxide and prostacyclin through flk-1/KDR activation of c-Src.J Biol Chem 274(35):25130-5, 1999. Abstract: Vascular endothelial growth factor (VEGF) is a potent endothelial cell-specific mitogen that promotes angiogenesis, vascular hyperpermeability, and vasodilation by autocrine mechanisms involving nitric oxide (NO) and prostacyclin (PGI(2)) production. These experiments used immunoprecipitation and immunoassay procedures to characterize the signaling pathways by which VEGF induces NO and PGI(2) formation in cultured endothelial cells. The data showed that VEGF stimulates complex formation of the flk-1/kinase-insert domain-containing receptor (KDR) VEGF receptor with c-Src and that Src activation is required for VEGF induction of phospholipase C gamma1 activation and inositol 1,4,5-trisphosphate formation. Reporter cell assays showed that VEGF promotes a approximately 50-fold increase in NO formation, which peaks at 5-20 min. This effect is mediated by a signaling cascade initiated by flk-1/KDR activation of c-Src, leading to phospholipase C gamma1 activation, inositol 1,4,5-trisphosphate formation, release of [Ca(2+)](i) and nitric oxide synthase activation. Immunoassays of VEGF-induced 6-keto prostaglandin F(1alpha) formation as an indicator of PGI(2) production revealed a 3-4-fold increase that peaked at 45-60 min. The PGI(2) signaling pathway follows the NO pathway through release of [Ca(2+)](i), but diverges prior to NOS activation and also requires activation of mitogen-activated protein kinase. These results suggest that NO and PGI(2) function in parallel in mediating the effects of VEGF.Comments: Guyton (reference above) showed that "booting" the leg raises prostacyclin. Here we see that VEGF also stimulates prostacyclin.

Heeschen C, Jang JJ, Weis M, Pathak A, Kaji S, Hu RS, Tsao PS, Johnson FL, Cooke JP: Nicotine stimulates angiogenesis and promotes tumor growth and atherosclerosis. Nat Med 7(7):833-9, 2001. We provide anatomic and functional evidence that nicotine induces angiogenesis. We also show that nicotine accelerates the growth of tumor and atheroma in association with increased neovascularization. Nicotine increased endothelial-cell growth and tube formation in vitro, and accelerated fibrovascular growth in vivo. In a mouse model of hind-limb ischemia, nicotine increased capillary and collateral growth, and enhanced tissue perfusion. In mouse models of lung cancer and atherosclerosis, we found that nicotine enhanced lesion growth in association with an increase in lesion vascularity. These effects of nicotine were mediated through nicotinic acetylcholine receptors at nicotine concentrations that are pathophysiologically relevant. The endothelial production of nitric oxide, prostacyclin and vascular endothelial growth factor might have a role in these effects. Comments: In other work, Cooke's laboratory has shown that nitric oxide induces synthesis of vascular endothelial growth factor by rat vascular smooth muscle cells (Arterioscler Thromb Vasc Biol 20:659-66, 2000) and that angiogenesis is impaired by hypercholesterolemia (Circulation 102:1.414-9, 2000). The latter effect is related to nitric oxide through the endogenous inhibitor of NOS, ADMA. ADMA or asymmetric dimethylarginine is an arginine analogue that competes with arginine for NOS. The effect of ADMA is reversed by supplemental arginine. Elevated plasma levels of ADMA and an impairment of the NOS pathway potentially adversely affecting angiogenesis is seen in hypertension, hyperglycemia, hyperhomocysteinemia, hypertriglyceridemia and insulin resistance. The effects of nicotine and cholinergic agents on wound healing that Cooke's group has reported is discussed further in our Neuropathy section (see Dillon, Angiology 1991).

Hofmann MA, Kohl B, Zumbach MS, Borcea V, Bierhaus A, Henkels M, Amiral J, Schmidt AM, Fiehn W, Ziegler R, Wahl P and Nawroth PP: Hyperhomocyst(e)inemia and endothelial dysfunction in IDDM. Diabetes Care 21:841-848, 1998. Author's conclusions: Hyperhomocyst(e)inemia is common in nephropathic diabetic patients and may contribute to enchanced morbidity and mortality from cardiovascular diseases characteristically observed in IDDM patients with diabetic nephropathy. Comments: Any article with 12 authors must be important. Elevated levels of homocyst(e)ine have been associated with several mechanisms promoting vascular disease. Fasting levels may be determined by remethylation (vitamin B-12 and folate- dependent) while post load levels may be related to abnormalities in transsulfation (vitamin B-6 dependent). This article is included because any vascular specialist worth his salt should remember to prescribe simple vitamins (folate, vitamin B-12 and possibly vitamin B6) if homocyst(e)ine levels are elevated... and should suspect elevations in IDDM patients especially in those with nephropathy.

Hu GF: Neomycin inhibits angiogenin-induced angiogenesis.Proc Natl Acad Sci 95: 9791-5, 1998.Abstract: A class of angiogenesis inhibitor has emerged from our mechanistic study of the action of angiogenin, a potent angiogenic factor. Neomycin, an aminoglycoside antibiotic, inhibits nuclear translocation of human angiogenin in human endothelial cells, an essential step for angiogenin-induced angiogenesis. The phospholipase C-inhibiting activity of neomycin appears to be involved, because U-73122, another phospholipase C inhibitor, has a similar effect. In contrast, genistein, oxophenylarsine, and staurosporine, inhibitors of tyrosine kinase, phosphotyrosine phosphatase, and protein kinase C, respectively, do not inhibit nuclear translocation of angiogenin. Neomycin inhibits angiogenin-induced proliferation of human endothelial cells in a dose-dependent manner. At 50 microM, neomycin abolishes angiogenin-induced proliferation but does not affect the basal level of proliferation and cell viability. Other aminoglycoside antibiotics, including gentamicin, streptomycin, kanamycin, amikacin, and paromomycin, have no effect on angiogenin-induced cell proliferation. Most importantly, neomycin completely inhibits angiogenin-induced angiogenesis in the chicken chorioallantoic membrane at a dose as low as 20 ng per egg. These results suggest that neomycin and its analogs are a class of agents that may be developed for anti-angiogenin therapy. Comments: Human angiogenin is a plasma protein with angiogenic and ribonucleolytic activities. Angiogenin inhibits both DNA replication and proliferation of aortic smooth muscle cells. Serum angiogenin levels are increased among diabetic youngsters, irrespective of the duration and metabolic control of the disease, as well as in female subjects, with or without diabetes. In the ladies, a significant difference exists between levels in the proliferative and secretory phase of the menstrual cycle. Furthermore, serum angiogenin levels increase significantly from fetal life to adulthood, possibly implying additional biological functions to that of angiogenesis. In patients with advanced arteriosclerosis obliterans, raised levels of angiogenin (and laminin) may be found possibly indicating endothelial damage caused by reduced vascular perfusion or compensatory revascularization, or both. As with VEGF, values rise with growing tumors and inhibition of its action may become a means to inhibit tumor growth. A similar protein is found in bovine milk. Clinically, this paper is important because it raises the possibility of inhibiting the healing of an ischemic ulcer with the application of ointments containing neomycin, but not gentamicin and other aminoglycosides.

Huang P, Li S, Han M, Xiao Z, Yang R, Han ZC: Autologous transplantation of granulocyte colony-stimulating factor-mobilized peripheral blood mononuclear cells improves critical limb ischemia in diabetes. Diabetes Care 28:2155-60, 2005. OBJECTIVE: To assess the application of autologous transplantation of granulocyte colony-stimulating factor (G-CSF)-mobilized peripheral blood mononuclear cells (PBMNCs) in the treatment of critical limb ischemia (CLI) of diabetic patients and to evaluate the safety, efficacy, and feasibility of this novel therapeutic approach. RESEARCH DESIGN AND METHODS: Twenty-eight diabetic patients with CLI were enrolled and randomized to either the transplant group or the control group. In the transplant group, the patients received subcutaneous injections of recombinant human G-CSF (600 mug/day) for 5 days to mobilize stem/progenitor cells, and their PBMNCs were collected and transplanted by multiple intramuscular injections into ischemic limbs. All of the patients were followed up after at least 3 months. RESULTS: At the end of the 3-month follow-up, the main manifestations, including lower limb pain and ulcers, were significantly improved in the patients of the transplant group. Their laser Doppler blood perfusion of lower limbs increased from 0.44 +/- 0.11 to 0.57 +/- 0.14 perfusion units (P < 0.001). Mean ankle-brachial pressure index increased from 0.50 +/- 0.21 to 0.63 +/- 0.25 (P < 0.001). A total of 14 of 18 limb ulcers (77.8%) of transplanted patients were completely healed after cell transplantation, whereas only 38.9% of limb ulcers (7 of 18) were healed in the control patients (P = 0.016 vs. the transplant group). No adverse effects specifically due to cell transplantation were observed, and no lower limb amputation occurred in the transplanted patients. In contrast, five control patients had to receive a lower limb amputation (P = 0.007, transplant vs. control group). Angiographic scores were significantly improved in the transplant group when compared with the control group (P = 0.003). CONCLUSIONS: These results provide pilot evidence indicating that the autologous transplantation of G-CSF-mobilized PBMNCs represents a simple, safe, effective, and novel therapeutic approach for diabetic CLI. Comments: The provision of normal substances (growth hormone, insulin, glucagon, cortisone etc) to normal subjects has in general provided no clinical benefit. Here we are told that G-CSF had benefit in patients with critical leg ischemia. Time will tell.

Inada K, Koike S, Shirai N, Matsumoto K, and Hirose M: Effects of intermittent pneumatic leg compression for prevention of postoperative deep venous thrombosis with special reference to fibrinolytic activity. Am J of Surg 155: 602-605, 1988. Summary...."A significant shortening of the euglobulin lysis time by intermittent pneumatic leg compression, in addition to its hemodynamic effects, is considered an important factor in the prevention of postoperative deep venous thrombosis." Discussion...."It is important to start leg compression before induction of anesthesia because venous return is apt to be lower at the beginning of anesthesia, and deep vein thrombosis develops during operation in in the early postoperative period, as confirmed by fibrinogen uptake tests."

Jacobs DG, Piotrowski JJ, Hoppensteadt DA, Salvator AE, Fareed J: Hemodynamic and fibrinolytic consequences of intermittent pneumatic compression: preliminary results. J Trauma 40:710-16.1996. Abstract: OBJECTIVE: To elucidate the time course and magnitude of hemodynamic and fibrinolytic changes associated with sequential gradient intermittent pneumatic compression (SGIPC). DESIGN: Two-phase, intervention and response investigation in normal volunteers. MATERIALS AND METHODS: Subjects were assigned to control (phase I) or compression (phase II) groups. Serial blood samples were obtained via femoral venous catheters for tissue plasminogen activator (tPA), plasminogen activator inhibitor (PAI-1), tPA-PAI-1 complex (tPA-PAI), and euglobulin lysis time (ELT) from all subjects and for fibrin degradation products (FbDP) and fibrinogen degradation products (FgDP) from phase II subjects. Duplex venous scanning was carried out on phase II subjects before and during SGIPC. RESULTS: Catheter placement caused elevations in PAI-1 and tPA-PAI, which stabilized within 4 hours of catheter insertion. In phase II, SGIPC induced significant increases in FbDP, FgDP, and tPA-PAI and decreases in ELT and PAI-1, all of which quickly reverted to baseline on termination of compression. Femoral venous blood flow increased by more than 100% with SGIPC. CONCLUSIONS: Sequential gradient intermittent pneumatic compression induces prompt, but short-lived, alterations in both fibrinolytic and hemodynamic function. Noncontinuous SGIPC may result in suboptimal thromboembolic prophylaxis.

Kim C-H, Park H-J, Park J-Y, Hong S-K, Yoon Y-H, Lee K-U: High serum lipoprotein(a) levels in Korean type 2 diabetic patients with proliferative diabetic retinopathy. Diabetes Care 21:2149-2151, 1998. Authors conclusions: "Korean type 2 diabetic patients with PDR had higher serum Lp(a) levels versus those with no diabetic retinopathy or with NPDR. Although these results suggest that Lp(a) might play a role in the occlusion of retinal capillaries leading to PDR, further prospective studies are required to prove the causal relationship." Comments: This article was included because apo(a) has a structural similarity to plasminogen and, hence, has been suggested to have antifibrinolytic properties. High serum Lp(a) levels may be an independent risk factor for atherogenesis and thromboembolism. We are hoping that some of the clinics using our boot systems may show increased fibrinolytic activity induced by booting may neutralize the effects of factors like Lp(a) and explain the long term benefits of booting as seen in our patient history section (case 2 long term benefits in spite of poor glycemic control and cases 143, 147 and 149 in whom improvement in retinopathy was associated with booting).

Klein KL and Pittelkow MR: Tissue plasminogen activator for treatment of livedoid vasculitis. May Clin Proc 67:923-933, 1992. Summary: "Livedoid vasculitis, a hyalinizing vasculopathy, is characterized by extensive formation of microthrombi and deposition of fibrin in the middermal vessels, which result in epidermal infarction"..."In a prospective study of nonhealing ulcers"..."high incidence of anticardiolipin antibodies, lupus anticoagulants, increased levels of plasminogen activator inhibitor, and low levels of endogenous tissue plasminogen activator (t-PA) activity"..."low-dose t-PA (10 mg) was administered intravenously during a four hour period daily for 14 days"...dramatic effect in 5/6 patients...the 6th rethrombosed but responded to retreatment with concurrent anticoagulation. Comments: Would therapy with the Circulator Boot have done as well?

Knight MTN and Dawson R: Effect of intermittent compression of the arms on deep vein thrombosis in the legs. Lancet II: 1265-1267, 1976. Summary: Despite the presence of venostasis in the legs, intermittent compression of the arms during and after surgery reduced the incidence of deep venous thrombosis (D.V.T.) in the legs to half that in control patients and maintained blood fibrinolytic activity at preoperative values. It is suggested that the release of fibrinolytic activators is essential to the prophylactic action of pneumatic leggings.Comments: This is an old but important study. 128 cancer-free patients over age fifty without histories of diabetes, D.V.T., pulmonary embolism, thyroid or renal disease and varicose veins were studied. Not only was a fibrinolytic effect noted but a important clinical benefit found also; a decrease in postoperative D.V.T. was documented with the use of I-125 labelled fibrinogen leg scans.

Koksch M, Zeiger F, Wittig K, Pfeiffer D, Ruehlmann C: Haemostatic derangement in advanced peripheral occlusive arterial disease. Int Angiol 18:256-62, 1999. BACKGROUND: Dysbalance of the coagulation and fibrinolysis system was suspected to be a further risk factor for the progression of peripheral occlusive arterial disease (POAD). Reports on disturbed platelet function in advanced disease, however, were contradictory. Therefore, we studied haemostasis parameters and platelet function in symptomatic patients with peripheral arterial disease. METHODS: 60 peripheral arterial disease patients hospitalised for invasive diagnostic procedures were included into this comparative study. Patients were clinically stratified according to the criteria for chronic limb ischemia (grade I: n=36; grade II: n=11; grade III: n=13). Plasma fibrinogen, antithrombin III, von Willebrand factor, tissue plasminogen activator (tPA), plasminogen activator inhibitor-1 (PAI-1) prothrombin time, and activated partial thromboplastin time were determined using standard methods. We measured flow cytometrically, the platelet activation marker P-selectin on nonstimulated, ADP- and TRAP-6-stimulated platelets. Angiographic data were assessed using the Bollinger score. RESULTS: Plasma levels of the procoagulant proteins fibrinogen (grade I: 3.7/grade II: 3.9/grade m: 4.0 g/l) and vWF (158/156/178%) increased and of antithrombin III (109/103/102%) and the PAI-1/tPA ratio (5.2/5.0/4.1) decreased with progressive disease. Highest platelet activation levels were observed in the CLI grade II subgroup. A significant correlation of disease severity was seen with the ankle-brachial pressure index (p=0.006; r=0.39) and with the Bollinger score (p=0.002; r=-0.41). CONCLUSIONS: Progressive peripheral obstructive arterial disease was associated with platelet hyper-reactivity, haemostatic dysbalance of pro- and anticoagulant proteins, and a counterregulatory increase of fibrinolytic activity. Therapeutic concepts should include these pathogenetic mechanisms.

Kosir MA, Schmittinger L, Barno-Winarski L, Duddella P, Pone M, Perales A, Lange P, Brish LK, McGee K, Beleski K, Pawlak J, Mammen E, Sajahan NP, Kozol RA: Prospective double-arm study of fibrinolysis in surgical patients.J Surg Res 74:96-101, 1998. Summary: BACKGROUND: During surgery, the balance between thrombosis and fibrinolysis is altered. Methods reported to increase fibrinolysis, such as compression devices, may reduce venous thrombosis. However, there are no prospective studies comparing methods and the effect on fibrinolysis. MATERIALS AND METHODS: In a prospective study, general surgical patients were randomized to either sequential compression devices (Group 1) or subcutaneous heparin (Group 2), and fibrinolysis factors were measured in order to determine the effect on the fibrinolysis system. Blood samples were drawn at a similar time of the day with the tourniquet off. Specifically, t-PA antigen, plasminogen activator inhibitor-1 (PAI-1), and D-dimer were measured preoperatively (preop) and on Postoperative Days (POD) 1 and 7 by the ELISA method. Fibrinolysis factors were reported as the mean +/- SD and as percentage change from preoperative values. Noninvasive vascular studies were performed preop, and on POD 1, 7, and 30, by an examination of the infrainguinal venous system and external iliac veins in bilateral lower extremities. Nonambulatory patients were excluded from the study and DVT prophylaxis methods were initiated at surgery and used through POD 2. RESULTS: For the 136 patients in the study, there were no differences in clinical characteristics such as age, surgical time (all > 60 min), anesthesia type (general or spinal), type of surgical procedure, or other risk factors for DVT. Two DVTs occurred at POD 1 and 30 (both Group 2), and one pulmonary embolism in each group (POD 7 for Group 1; POD 1 for Group 2). For subjects without thrombosis, D-dimer changes were parallel for both groups, increasing through POD 7. Similarly, t-PA antigen levels rose from baseline on POD 1 in both groups, with a return toward baseline by POD 7. The PAI-1 levels increased on POD 1 in both groups, but severalfold more in Group 1 (compression devices). The elevation in PAI-1 decreased by 50% in Group 1 by POD 7, while values returned to normal in Group 2. These changes were not significant using the Mann-Whitney test. Only three patients had thrombotic episodes so that data on changes in fibrinolysis factors are difficult to compare with the larger group. CONCLUSIONS: This is the first report of a prospective, randomized comparison of fibrinolysis factors using sequential compression devices in comparison to low dose unfractionated heparin in general surgical patients, and comparing postoperative values to preop. Both groups showed an enhanced fibrinolysis by elevation in t-PA antigen and D-dimer on POD 1, as expected when fibrinolysis occurs. While PAI-1 and t-PA work in parallel, the marked elevation of PAI-1 on POD 1 (although only slightly above reference values) and continuing into POD 7 for subjects using compression devices requires further inquiry. The elevation of PAI-1 in the face of elevated t-PA and D-dimer has been reported, but the comparison between patients using sequential compression devices and mini-dose heparin has not been reported. The reason for the elevation requires additional study into other influences on the synthesis, secretion, and/or function of PAI-1 that do not affect t-PA.

Kraegen EW, Cooney GJ, Ye J, Thompson AL.: Triglycerides, fatty acids and insulin resistance--hyperinsulinemia. Exp Clin Endocrinol Diabetes 109(4):S516-S526, 2001. There is now much interest in the mechanisms by which altered lipid metabolism might contribute to insulin resistance as is found in Syndrome X or in Type II diabetes. This review considers recent evidence obtained in animal models and its relevance to humans, and also likely mechanisms and strategies for the onset and amelioration of insulin resistance. A key tissue for development of insulin resistance is skeletal muscle. Animal models of Syndrome X (eg high fat fed rat) exhibit excess accumulation of muscle triglyceride coincident with development of insulin resistance. This seems to also occur in humans and several studies demonstrate increased muscle triglyceride content in insulin resistant states. Recently magnetic resonance spectroscopy has been used to demonstrate that at least some of the lipid accumulation is inside the muscle cell (myocyte). Factors leading to this accumulation are not clear, but it could derive from elevated circulating free fatty acids, basal or postprandial triglycerides, or reduced muscle fatty acid oxidation. Supporting a link with adipose tissue metabolism, there appears to be a close association of muscle and whole body insulin resistance with the degree of abdominal obesity. While causal relationships are still to be clearly established, there are now quite plausible mechanistic links between muscle lipid accumulation and insulin resistance, which go beyond the classic Randle glucose-fatty acid cycle. In animal models, dietary changes or prior exercise which reduce muscle lipid accumulation also improve insulin sensitivity. It is likely that cytosolic accumulation of the active form of lipid in muscle, the long chain fatty acyl CoAs, is involved, leading to altered insulin signalling or enzyme activities (eg glycogen synthase) either directly or via chronic activation of mediators such as protein kinase C. Unless there is significant weight loss, short or medium term dietary manipulation does not alter insulin sensitivity as much in humans as in rodent models, and there is considerable interest in pharmacological intervention. Studies using PPARgamma receptor agonists, the thiazolidinediones, have supported the principle that reduced muscle lipid accumulation is associated with increased insulin sensitivity. Other potent systemic lipid-lowering agents such as PPARalpha receptor agonists (eg fibrates) or antilipolytic agents (eg nicotinic acid analogues) might improve insulin sensitivity but further work is needed, particularly to clarify implications for muscle metabolism. In conclusion, evidence is growing that excess muscle and liver lipid accumulation causes or exacerbates insulin resistance in Syndrome X and in Type II diabetes; development of strategies to prevent this seem very worthwhile.

Lang EK: Streptokinase therapy: Complications of intra-arterial use. Radiology 154: 75-77, 1985. Author's abstract: An inordinately high rate of renal complications was encountered among 35 patients treated for thrombotic or thromboembolic occlusion of the leg by injection of streptokinase into a bypass graft or a native artery. Five patients demonstrated massive myoglobinuria following restoration of flow to ischemic and necrotic tissue; acute tubular necrosis developed in 2 of them, and 1 patient died as a result of renal shutdown, electrolyte imbalance, hypofibrinogenemia, and mediastinal and retroperitoneal hemorrhage. Massive myoglobinuria was also noted in 5 out of 13 patients with compartment syndrome but no evidence of ischemic necrosis. This complication could be lessened by fasciotomy and resection of the upper third of the fibula. Although myoglobinuria and complications such as acute tubular necrosis are rarely reported, they are not unexpected following muscular ischemia. Attempts to salvage irreparably damaged tissues by re-establishing circulation appear to carry an unacceptably high risk of renal complications and may even threaten the life of the patient. Comments: The author points out that a tissue pressure of 30 mm Hg existing for 8 hours or longer may be the critical point at which tissue necrosis ensues and compartment syndrome may develop. His group apparently, however, did not use pressure measurements as a guide to need for fasciotomy. Among thousands of boot patients, we have not recognized re-perfusion complications due to boot therapy. Among our web case reports, patient #182 developed renal shutdown after fasciotomy. Boot therapy may have helped restore his kidney function. Renal function was generally benefited in case #32 and progression of his disease was attributed to increasing renal failure over time; myoglobin from his foot might have also contributed but was not considered. Fasciotomy was considered in case #122 but Long-Boot therapy was used successfully instead and also supported her heart.

Law MM, Gelabert HA, Colburn MD, Quiñones-Baldrich WJ, Aln SS and Moore WS: Continuous postoperative intra-arterial urokinase infusion in the treatment of no reflow following revascularization of the acutely ischemic limb. Ann Vasc Surg 8: 66-73, 1994. The loss of distal tissue perfusion sufficient for limb salvage following restoration of inflow to an acutely ischemic extremity has been referred as the "no-reflow" phenomenon. In this report 12 such patients were treated with intra-arterial urokinase infusions in the immediate postoperative period. The procedure was complicated by bleeding sufficient to require transfusions in seven patients. One patient required reoperation for a groin hematoma. Limb salvage resulted in 7 of the 12 patients. Six patients had viable functional limbs at follow-up 6.4 to 49.7 months later. The authors felt their results supported the theory that the no-reflow phenomenon is due in part to distal intravascular fibrin deposition. Comments: Why not boot these patients?

Le BD, Addo T and de Lemos JA,: The endocrine heart: B-type natriuretic peptide as a diagnostic and therapeutic agent in cardiovascular disease. The Endocrinologist 13: 97-105, 2003. Authors' Conclusion: Since the discovery of natiuretic peptides 5 decades ago, the integration of basic science and clinical pharmacology has brought natriuretic peptides, in particular brain natriuretic peptide, into the forefront of clinical medicine. The first and most important use of BNP is as a biomarker to assist in the diagnosis and prognostic assessment of patients with suspected heart failure. Here, the remarkably high negative predictive value of BNP allows clinicians to exclude the presence of heart failure in patients with acute dypsnea. A high BNP value, however, suggests decompensated heart failure, but intermediate values lack specificity given multiple disease entities that may elevate BNP within this range. Therefore, an intermediate range BNP value should prompt further evaluation, and the results should be interpreted in the appropriate clinical context. As a prognostic indicator, BNP elevation is associated with a higher likelihood of mortality and heart failure progression in patients with chronic congestive heart failure, acute myocardial infarction, and acute coronary syndromes with or without myocardial necrosis. Finally, BNP has also been developed as a therapeutic agent: nesiritide (recombinant human BNP) improves hemodynamic indices and clinical symptoms in patients with decompensated heart failure. Many other potential uses for BNP have been explored, but further large randomized trials are needed to validate these findings before incorporation into clinical practice. Comments: BNP determinations would appear to be a natural for any studies on the effects of Circulator Boot therapy in patients with heart disease. BNP levels correlate nicely with the New York Heart Association classification (see Maisel A et al, N Engl J Med 347:161-167, 2002)

Levy AP: A cellular paradigm for the failure to increase vascular endothelial growth factor in chronically hypoxic states. Coron Artery Dis 10:427-30, 1999. BACKGROUND: Angiogenesis, or new blood vessel formation, is the physiological adaptation of a tissue to hypoxia or ischemia. However, this compensatory response to hypoxic stress in vivo is often insufficient. In many of the conditions in which the angiogenic response to tissue hypoxia is insufficient, such as chronic critical limb ischemia or myocardial hibernation, the hypoxic stress is chronic and persistent, lasting for days or even months. Vascular endothelial growth factor (VEGF) has been demonstrated in vivo and in vitro to be the principal mediator of hypoxia-induced angiogenesis. We propose that the lack of compensatory angiogenesis in response to tissue hypoxia in many clinical syndromes characterized by chronic hypoxia is due to a failure to induce VEGF appropriately. METHODS AND RESULTS: Heart or liver cells were grown under conditions of chronic hypoxia, returned to a normoxic environment, and then rechallenged with hypoxia. We found that the hypoxic induction of VEGF mRNA was markedly blunted using this algorithm. Furthermore, transient transfection studies using the VEGF promoter containing an oxygen-responsive enhancer element failed to show induction in cells pretreated by subjection to chronic hypoxia. CONCLUSIONS: Hypoxic pretreatment results in a blunting of the ability of a cell to induce VEGF in response to subsequent episodes of hypoxia. This may provide a rationale for the inadequate amount of compensatory angiogenesis seen in many chronic ischemic disorders. Comments: It would make sense that there would be a state sufficiently anoxic in degree and chronicity that VEGF might not work. Tissues with severe anoxia commonly have no pulsatile blood flow. Will VEGF work if there is no pulsatile flow in the capillary bed? In our patient history section, we show patients with pulseless feet and non-healing ulcers who have had very low transcutaneous PO2 levels (0 to 20 mm Hg) and who have healed with boot therapy. Booting restores some pulsatile flow during the therapy and over time is associated with improvement in vascular tests

Levy PJ, Cooper CF and Gonzalez MF: Massive lower extremity arterial thrombosis and acute hepatic insufficiency in a young adult with premature atherosclerosis associated with hyperlipoprotein(a)emia and antiphospholipid syndrome. A case report. Angiology 46: 853-858, 1995. The laboratory findings included abnormal liver function studies, moderately elevated antiphospholipid antibodies, elevated fibrinogen and lipoprotein (a) levels, and deficient fibrinolysis. He was treated by femoral thrombectomy and meticulous anticoagulation.

Lieber CS:Alcohol and health: a drink a day won't keep the doctor away. Cleve Clin J Med 70:945-6, 948, 951-3, 2003. We should not advise patients to start drinking alcohol for its alleged cardiovascular benefits. The negative effects of alcohol are well established, and the evidence of alcohol's benefits comes mainly from epidemiologic studies that were not well controlled for other influences, such as lifestyle factors. Moreover, we have other means of lowering cardiovascular risk that are safe and proven. Those who are healthy and whose drinking history shows little risk of developing alcohol dependency may continue to drink moderate amounts. Heavy drinkers should be advised to quit. Comments: Heavy drinkers may lose weight and become malnourished; they may die with cirrhosis, osteoporosis and other complications, but not coronary heart disease. Moderate drinkers may have a rise in HDL that commonly was embraced as an explanation for their having less coronary heart disease. However, they get a rise in HDL3 not HDL2 which offers some cardiac protection. Alcohol is, of course, a vasodilator that operates on normal vessels but not arteriosclerotic ones (red nose and a cold foot). Further, alcohol has adverse effects on our immune system and leukocyte function. Alcohol would appear to have no beneficial role in the treatment of peripheral vascular disease and the diabetic foot ulcer.

Lim HS, Blann AD, Chong AY, Freestone B, Lip GY: Plasma vascular endothelial growth factor, angiopoietin-1, and angiopoietin-2 in diabetes: implications for cardiovascular risk and effects of multifactorial intervention. Diabetes Care 27:2918-24, 2004. OBJECTIVE: Vascular endothelial growth factor (VEGF) and angiopoietin (Ang)-1 and Ang-2 are mediators of angiogenesis. More recent data suggest that the balance between these growth factors may affect vascular endothelial integrity. Because diabetes is closely associated with endothelial perturbation, we studied plasma levels of these angiogenic growth factors in patients with diabetes; their relationship with glycemia, inflammation, and endothelial damage/dysfunction; and the effect of intensified cardiovascular risk management. RESEARCH DESIGN AND METHODS: We measured plasma VEGF, Ang-1, and Ang-2 alongside plasma von Willebrand factor (vWf) and urine albumin-to-creatinine ratio (marking endothelial damage/dysfunction) and interleukin (IL)-6 in 94 patients (38 with overt cardiovascular disease [CVD]) with diabetes and 34 normal control subjects. RESULTS: Plasma vWf (P=0.009), IL-6 (P <0.001), VEGF (P=0.001), and Ang-2 (P=0.001), but not Ang-1 (P=0.635), were higher in diabetic patients with and without CVD than in control subjects. On multivariate analysis, HbA1c was an independent predictor of plasma VEGF (P=0.032) and Ang-2 (P=0.015). Of the 94 patients, a subgroup of 33 patients with and 31 patients without CVD participated in a year of intensified cardiovascular risk management. HbA1c and LDL cholesterol reduced significantly with treatment, along with associated reductions in plasma vWf and VEGF in both groups (P <0.001). Ang-2 decreased (P <0.001) only in patients without CVD. There were no significant changes in plasma IL-6 levels in both groups. CONCLUSIONS: Plasma Ang-2 (but not Ang-1), like VEGF levels, are selectively elevated in patients with diabetes and are associated with indexes of endothelial damage/dysfunction, regardless of vascular disease. Intensive multifactorial intervention is associated with reductions in plasma VEGF, vWf, and (in patients without CVD) Ang-2 levels, possibly reflecting an improved vascular profile with treatment.

Lottermoser K, Hertfelder HJ, Vetter H, Dusing R: Fibrinolytic function in diuretic-induced volume depletion. Am J Hypertens 13(4 Pt 1):359-63, 2000. Abstract: Accumulating evidence suggests that the renin-angiotensin system (RAS) may participate in the regulation of fibrinolytic function. In clinical studies, however, angiotensin-converting enzyme (ACE) inhibitors and the angiotensin II receptor antagonist losartan have failed to consistently affect endogenous fibrinolysis. Because such an effect may depend on the degree of prestimulation of the RAS, we have studied parameters of fibrinolytic function in 15 healthy volunteer subjects during baseline (day 1) and after 10 days of treatment with 25 mg of hydrochlorothiazide (HCT)/day (day 11). On the last day of the study (day 12), a single oral dose of 50 mg of losartan was given to the volunteers in addition to HCT and fibrinolytic function was assessed at the peak effect of losartan (5 h later). Plasma renin activity (PRA) was significantly stimulated during diuretic treatment (1.35 +/- 0.21 v 0.34 +/- 0.06 ng mL(-1) x h(-1) [P < .001]) and further increased after losartan (6.39 +/- 1.16 ng mL(-1) x h(-1) [P < .001]). No effects of either the diuretic or losartan could be observed on tissue-type plasminogen activator (t-PA) antigen concentration and activity. However, 10 days of treatment with HCT significantly increased plasminogen activator inhibitor-1 (PAI-1) antigen (26.8 +/- 5.8 v 21.1 +/- 3.4 ng/mL [p = .037]). In addition, PAI-1 activity was also tentatively raised by HCT treatment (5.48 +/- 1.82 v 3.88 +/- 0.79 IU/mL [P = .067]). In spite of the marked further rise in PRA after losartan, the stimulation of PAI-1 antigen and activity was blunted by losartan (24.4 +/- 3.6 ng/mL and 4.55 +/- 0.99 IU/mL, respectively). Our results demonstrate that volume depletion induced by HCT treatment is associated with a rise in PAI-1. Acute administration of losartan is capable of blunting this effect, suggesting that the angiotensin II type 1 receptor may participate in this effect of angiotensin II. Comments: Hypovolemia and hypotension are not an uncommon accompaniment to vigorous hemodialysis, leading the dialysis nurse to elevate the feet to prevent syncope. The diabetic arteriosclerotic patient, of course, may not perfuse his/her legs under such circumstances. Here we learn that such hypovolemia may also promote a hypercoagulable state.

Matsuzawa Y, Funahashi T, Nakamura T: Molecular mechanism of metabolic syndrome X: contribution of adipocytokines adipocyte-derived bioactive substances. Ann N Y Acad Sci 892:146-54, 1999. Syndrome X is a clinical syndrome in which multiple risks cluster in an individual, and it is a common basis of vascular disease in the industrial countries. The molecular basis of Syndrome X, however, has not been elucidated. We have analyzed body fat distribution using CT scan and have shown that people who have accumulated intra-abdominal visceral fat frequently have multiple risks and vascular diseases. Thus, "visceral fat syndrome" is a clinical entity compatible with Syndrome X. To clarify the molecular mechanism of the disorders in visceral fat syndrome, we analyzed the expressed genes in adipose tissue by a large-scale random sequencing. Unexpectedly, visceral fat expressed a variety of the genes for secretory proteins including various bioactive substances; we designated them adipocytokines. One of them, plasminogen activator inhibitor-1, was overproduced in accumulated visceral fat and might contribute to the development of vascular disease. We have also cloned a novel adipose-specific gene named adiponectin. Adiponectin is a collagen-like plasma protein which has an inhibitory effect on proliferation of vascular smooth muscle cells; its plasma levels are paradoxically decreased in obesity. Adipocytokines may play important roles in the development of the disorders in Syndrome X. Comments: Not only does obesity promote hyperlipidemia, hypertension and diabetes, all of which we learn elsewhere in these papers may promote abnormal clotting, but here we learn that adipocytokines may increase PAI-1. Valle M et al (Infantile obesity: a situation of atherothrombotic risk? Metabolism 49:672-5, 2000) reported similar problems in children. Obesity in all ages should be considered a disease and not a social variant!

Mavrommatis AC, Theodoridis T, Economou M, Kotanidou A, El Ali M, Christopoulou-Kokkinou V, Zakynthinos SG: Activation of the fibrinolytic system and utilization of the coagulation inhibitors in sepsis: comparison with severe sepsis and septic shock. Intensive Care Med 27:1853-1859, 2001. OBJECTIVES: To determine whether the fibrinolytic system is activated and coagulation inhibitors are utilized in sepsis, to compare the findings detected in sepsis with those found in severe sepsis and septic shock, and to compare the role played by different infectious pathogens on fibrinolysis and coagulation inhibitors. DESIGN AND SETTING: Prospective study comparing patients with sepsis, severe sepsis, and septic shock and healthy volunteers in the general intensive care unit of a tertiary university hospital. PATIENTS: Eighty-two consecutive septic patients (47 with sepsis, 18 with severe sepsis, and 17 with septic shock), and 14 healthy volunteers (controls). MEASUREMENTS AND RESULTS: After blood sampling we measured activation markers of fibrinolysis [plasmin/alpha(2)-antiplasmin complexes (PAP), complexes of tissue plasminogen activator/plasminogen activator inhibitor (tPA/PAI), fibrin(ogen) degradation products (FDPs), D-dimmers fibrin degradation products (D-d)], the utilization marker of antithrombin III (ATIII) thrombin/antithrombin complexes (TAT), several factors of fibrinolysis [plasminogen, tissue plasminogen activator (tPA), plasminogen activator inhibitor 1 (PAI-1), alpha(2)-antiplasmin], and the natural coagulation inhibitors [ATIII, protein C (PrC), protein S (PrS)]. In sepsis, PAP, FDPs, D-d, and TAT were increased to 439.8+/-32.35 &mgr;g/l, 57% positive, 49% positive, and 3.46+/-0.27 &mgr;g/l, respectively, compared with control subjects (205.57+/-28.58 &mgr;g/l, 0% positive, 7% positive, and 1.61+/-0.1 &mgr;g/l, respectively). These markers further increased in severe sepsis and septic shock. With the exception of a decrease in ATIII and an increase in tPA and PAI-1, coagulation inhibitors and factors of fibrinolysis were not changed in sepsis. In severe sepsis and mainly in septic shock, coagulation inhibitors (ATIII, PrC) and plasminogen were markedly decreased, whereas tPA and PAI-1 were further increased. All changes were independent of the causative infectious pathogen. CONCLUSIONS: Fibrinolysis is strongly activated and ATIII is utilized in sepsis. These findings are further enhanced in severe sepsis and septic shock. In sepsis only ATIII is decreased. In contrast, in severe sepsis and mainly in septic shock plasminogen and the main coagulation inhibitors (i.e., ATIII, PrC) are depleted, indicating exhaustion of fibrinolysis and coagulation inhibitors. Finally, Gram-positive, Gram-negative and other micro-organisms produce identical impairment.Comments: Many of our patients with cellulitis (See Case #1 in our Case History section, for example)have been toxic and unresponsive to appropriate systemic antibiotics. An infective arteritis and thrombosis of small vessels have been partial explanations why such patients had not responded to their intravenous antibiotics; the antibiotics just did not get to the infection. Our injection of antibiotics locally and pumping on the infected tissue has improved both the systemic status and the status of the infected limb rapidly. We do not know what effects the pumping has had on Protein C.

Maxwell AJ, Anderson BE, Cooke JP: : Nutritional therapy for peripheral arterial disease: a double-blind, placebo-controlled, randomized trial of HeartBar.Vasc Med 5:11-9, 2000. Division of Research and Development. Cooke Pharma, Inc., Belmont, CA 94002, USA. We investigated the clinical effects of a food bar enriched with L-arginine and a combination of other nutrients known to enhance the activity of endothelium-derived nitric oxide (EDNO) in individuals with claudication from atherosclerotic peripheral arterial disease. The study was a 2-week, double-blind, placebo-controlled trial of subjects randomized to three groups (two active bars, one active and one placebo bar, and two placebo bars per day) followed by an 8-week open-label period. Subjects (n=41) were outpatient volunteers with intermittent claudication. Pain-free and total walking distances were measured by variable-grade, treadmill exercise testing. Quality of life was assessed using the Medical Outcome Survey (SF-36). After 2 weeks of treatment, the pain-free walking distance increased 66% while the total walking distance increased 23% in the group taking two active bars/day. The general and emotional/social functioning components of the SF-36 also improved. These effects were not observed in the one active bar/day and placebo groups. The effects were maintained after 10 weeks and, in addition, an improvement in walking distance was observed in the group taking one active bar. These findings reveal that use of a nutrient bar designed to enhance EDNO activity improves pain-free and total walking distance as well as quality of life in individuals with intermittent claudication. Comments:Here we see basic research taken to a potentially practical and effective therapy. For more on this work see Jang JJ, Ho HK, Kwan HH, Fajardo LF, Cooke JP: Angiogenesis is impaired by hypercholesterolemia : role of asymmetric dimethylarginine. Circulation 102:1414-9, 2000.

Midorikawa S, Sanada H, Hashimoto S, Watanabe T: Enhancement by homocysteine of plasminogen activator inhibitor-1 gene expression and secretion from vascular endothelial and smooth muscle cells. Biochem Biophys Res Commun 272:182-5, 2000. In order to elucidate the relationship between homocysteine and the fibrinolytic system, we examined the effect of homocysteine on plasminogen activator inhibitor-1 (PAI-1) and tissue-type plasminogen activator (tPA) gene expression and protein secretion in cultured human vascular endothelial and smooth muscle cells in vitro. PAI-1 mRNA and secreted protein levels were both enhanced by homocysteine in a dose dependent manner, with significant stimulation of PAI-1 secretion observed at concentrations greater than 0.5 mM homocysteine. In contrast, secretion and mRNA expression of tPA were not significantly altered by homocysteine stimulation. Secretion of TGFbeta (transforming growth factor beta) and TNFalpha (tumor necrosis factor alpha), possible regulators of PAI-1 expression and secretion, were not stimulated by treatment with 1.0 mM homocysteine. These results suggests that hyperhomocysteinemia-induced atherosclerosis and/or thrombosis may be caused by homocysteine-induced stimulation of PAI-1 gene expression and secretion in the vasculatures by a mechanism independent from paracrine-autocrine activity of TGFbeta and TNFalpha. Comments: And through homocysteine a means for vitamins B12 and folic acid to alter fibrinolysis?

Missov RM, Stolk RP, van der Bom JG, Hofman A, Bots ML, Pols HAP and GrobbeeDE: Plasma fibrinogen in NIDDM, The Rotterdam Study. Diabetes Care 19:157-159, 1996. While plasma fibrinogen levels did not differ among individuals with and without NIDDM, after adjustment for age, sex, smoking, BMI and waist-to-hip ratios, they were higher in those receiving insulin therapy possibly reflecting worse metabolic control in this subgroup. Adjustment of fructosamine levels decreased the differences. Likewise the erythrocyte sedimentation rate was increased in those taking insulin. The authors pursued their study as elevated fibrinogen levels, possibly through associated changes in platelet aggregability, plasma viscosity and organ blood flow, have been recognized as a risk factor for myocardial infarction, stroke and albuminuria. Comment: The sed rate is cheaper. Does anyone know if it is as a good marker for arteriosclerotic disease?

Mohler ER III, Rajagopalan S, Olin JW, Trachtenberg JD, et al: Adenoviral-mediated gene transfer of vascular endothelial growth factor in criticl limb ischemia: safety results from a phase I trial. Vascular Medicine 8: 9-13, 2003. Abstract: Critical limb ischemia (CLI) is typified by rest pain and/or tissue necrosis secondary to advanced peripheral arterial disease (PAD) and is characterized by diminution in limb perfusion at rest. We tested the safety of an angiogenic strategy with CI-1023 (Ad(GV)VEGF121.10), a replication-deficient adenovirus encoding human vascular endothelial growth factor isoform 121 in patients with CLI as part of a phase I trial. Fifteen subjects >35 years of age with CLI and angiographic disease involving the infra-inguinal vessels underwent intramuscular injection of CI-1023 (4 x 10(8) to 4 x 10(10) particle units, n = 13) or placebo (n = 2). All of the patients tolerated the injection well and there were no serious complications related to the procedure. Transient edema was noted in one patient. A total of 79 adverse events were reported over the course of one year. One death (day 136) and one malignancy (day 332) occurred in the CI-1023 group. CI-1023 appears to be well tolerated and safe for single-dose administration in patients with critical limb ischemia due to PAD. Further studies are needed to determine the efficacy of this form of therapeutic angiogenesis. Care of these difficult patients is expensive and frustrating. I suspect that long-term booting is both more efficacious and economical. Comments: How did the patients fare? Among the 15 patients, ten bypass operations were done: one leg was bypassed twice in three patients, both legs were bypassed in one patient, one leg was bypassed and amputated three weeks later in one patient, and one patient had a single bypass. Overall, there were nine amputations. Serial ABI data were available in seven patients. A marked increase was noted in one placebo patient (to 0.91) and one study patient (to 0.75) who had had successful bypasses. Among four other bypass patients, no or mild improvement in ABI was seen. Among the four patients with serial studies and no bypasses, two had slight decreases in ABI and two had increases (0.11 and 0.14). The significnce of the outcome data is limited by the small size of the study. The care of these difficult patients is both expensive and frustrating. I suspect that long-term booting is both more efficacious and economical.

Morgan RH, Carolan G, Dsaila JV et al.: Arterial flow enhancement by impulse compression. Vasc Surg 25: 8-15, 1991. See Pneumatic Boot section. Here the authors suggest that the effects they measured were to the liberation of endothelial-derived relaxing factor.. or nitric oxide.

Nakamura H, Ariizumi M, Okazawa T, Nagase H, Yoshida M, Okada A: Involvement of endothelin in peripheral circulatory change induced by hand-arm vibration. Central European J of Public Health 3 Suppl: 27-30, 1995. Abstract: Physiologic mechanisms involving local vasoregulating factor, endothelium-derived relaxing factor (EDRF) and endothelium-derived constricting factors (EDCF) have been postulated to play a role in VWF. Recent evidence that endothelin is a potent vasoconstrictor peptide indicates that it may play a role in vasoregulation during vibration exposure through the local actions of EDRF or EDCF. Therefore, we examined the effects of grasping (50N) and hand-arm vibration with an unweighted acceleration of 50 m/s2 rms at a frequency of 120 Hz in the direction of the X-axis on digital blood flow (DBF) and on the level of plasma endothelin in 7 healthy male office workers. DBF was measured by an apparatus based on the thermal diffusion method where the thermal diffusion flow probe was incorporated in the Peltier's stack. In the grasping test, DBF decreased by about 40% from resting level within 1 minute after the grasping was begun, and was maintained at almost the same level during grasping, but increased immediately after cessation of grasping. In the vibration exposure test, initial decrease in DBF due to grasping was the same as that observed in the grasping test, but DBF gradually increased when exposure to vibration was performed simultaneously. No significant change in plasma endothelin level was induced by grasping. Endothelin was significantly lower after exposure to vibration than at rest and after grasping. The grasping-induced decrease in DBF seemed to be due to mechanical compression of the vessels. The negative correlation between DBF and endothelin during vibration exposure suggests that a reduction in release of endothelin from smooth muscle into the vessel cavity during vibration leads to vasodilatation, possibly attributable to the local axon reflex. Comments: Here we see that one form of physical therapy (vibration) is associated with a falloff in plasma endothelin level, vasodilatation and increased digital blood flow. Does another form of physical therapy (end-diastolic limb compressions) likewise decrease endothelin levels? And, if so, how long does the effect last?

Nakamura S, Nakamura I, Ma L, Vaughan DE, Fogo AB:Plasminogen activator inhibitor-1 expression is regulated by the angiotensin type 1 receptor in vivo. Kidney Int 58:251-9, 2000. Abstract: Plasminogen activator inhibitor-1 expression is regulated by the angiotensin type 1 receptor in vivo. BACKGROUND: The fibrinolytic system plays an important role in degrading fibrin-rich thrombi and in vascular and tissue remodeling. Elevated levels of plasminogen activator inhibitor-1 (PAI-1) can reduce the efficiency of the endogenous fibrinolytic system. Angiotensin (Ang) has been shown to regulate PAI-1 expression via the Ang type 1 (AT1) receptor in some tissues and via the AT4 receptor in cultured endothelium. The purpose of this study was to examine the tissue-specific pattern of PAI-1 expression in response to infusion of Ang II in vivo. METHODS: Adult male Sprague-Dawley rats (N = 5 in each group) were treated with four hours of intravenous infusions of Ang II or vehicle control while mean arterial pressure (MAP) was monitored: group 1, 600 ng/kg/min Ang II; group 2, Ang II + 10 mg/kg of the AT1 receptor antagonist (AT1RA) L158-809 q2 hour; group 3, Ang II + 0.01 to 0.1 mg/kg hydralazine as required to maintain normal blood pressure; and group 4, saline-infused controls. After infusion, tissue was harvested for Northern blotting, immunohistochemical analysis, and in situ hybridization. RESULTS: In group 1, Ang II infusion increased MAP from 105 +/- 8 to 160 +/-9 mm Hg (mean +/- SE, P < 0. 01). Ang II induced increased expression of PAI-1 mRNA in all tissues examined from 5.1-fold in the heart, 9.7-fold in the kidney, 10.0-fold in the aorta, and up to 30.0-fold in the liver (all P < 0. 01 vs. control). While both AT1RA (group 3) and hydralazine (group 4) prevented Ang II-induced elevation in blood pressure, the Ang II-dependent expression of PAI-1 mRNA was reduced by only AT1 receptor blockade. CONCLUSIONS: We conclude that in the rat, PAI-1 is induced in a variety of tissues by Ang II directly through the AT1 receptor, independent of its effects on blood pressure. Comments: Another possible means for drug therapy to alter fibrinolysis by AT1 receptor blockade?

Nitta K, Uchida K, Kimata N, Honda K, Kobayashi H, Kawashima A, Yumura W, Nihei H: Recombinant human erythropoietin stimulates vascular endothelial growth factor release by glomerular endothelial cells. Eur J Pharmacol 373:121-4, 1999. Abstract: We designed the present study to address the question of whether recombinant human erythropoietin stimulates DNA synthesis and vascular endothelial growth factor (VEGF) secretion in vitro using cultured bovine glomerular endothelial cells (GENs). Recombinant human erythropoietin dose-dependently stimulated the proliferation of GENs in culture, and this proliferative effect was inhibited by 1 microg/ml anti-VEGF antiserum. The increase in VEGF concentrations in the supernatants containing 10 U/ml rHuEpo was abolished by incubation with 10 microg/ml of anti-human rHuEPO antiserum, 0.2 microg/ml actinomycin D or 10 microg/ml cycloheximide. Taken together, rHuEpo stimulates GEN proliferation in vitro and VEGF release from these cells is associated with stimulation of RNA-dependent DNA and protein synthesis. Comments: Many diabetic patients referred for booting have both foot ulcers and renal failure. BUN and creatinine levels commonly improve up to 50% with regular Long-Booting. In this article, one is led to wonder if all patients with renal failure might benefit from erythropoietin even in the absence of a significant anemia.

Numminen H, Syrjala M, Benthin G, Kaste M, Hillbom M:The effect of acute ingestion of a large dose of alcohol on the hemostatic system and its circadian variation. Stroke 31:1269-73, 2000. BACKGROUND AND PURPOSE: Heavy binge drinking may trigger the onset of embolic stroke and acute myocardial infarction, but the underlying mechanisms are unclear. The effects of binge drinking on the hemostatic system and its circadian variation have not been investigated. We investigated the effects of an acute intake of a large dose of alcohol (1.5 g/kg). METHODS: Twelve healthy, nonsmoking men participated in sessions where they were served ethanol in fruit juice or served fruit juice alone and, lying in a supine position, were followed up for 12 to 24 hours. The treatments were randomized and separated from each other by a 1-week washout period. Blood and urine were collected for hemostatic measurements. RESULTS: The urinary excretion of the platelet thromboxane A(2) metabolite 2, 3-dinor-thromboxane B(2) was significantly (P<0.05) greater during the night after an evening intake of alcohol than during the control night. A smaller increase was observed during the daytime after an intake of alcohol in the morning. The effects on the endothelial prostacyclin metabolite 2,3-dinor-6-ketoprostaglandin F(1alpha) excretion were negligible. A 7-fold increase in plasminogen activator inhibitor 1 activity was observed after both morning (P><0. 05) and evening (P><0.01) intakes of alcohol. CONCLUSIONS: This is the first study to suggest that acute ingestion of a relatively large but tolerable dose of alcohol transiently enhances thromboxane-mediated platelet activation. The observations also demonstrate alcohol-induced changes in the normal circadian periodicity of the hemostatic system in subjects not accustomed to consumption of alcohol.>

Palmer RMJ, Ferrige AG and Moncada S: Nitric oxide release accounts for the biological activity of endothelium-derived relaxing factor. Nature 327:524-526, 1987.

Peng T, Jiang X, Wang Y, Hand A, Gillies C, Cone RE, O'Rourke J: Sympathectomy decreases and adrenergic stimulation increases the release of tissue plasminogen activator (t-PA) from blood vessels: functional evidence for a neurologic regulation of plasmin production within vessel walls and other tissue matrices. J Neurosci Res 1;57(5):680-92, 1999. Summary: Our recent morphologic studies indicated that peripheral nervous system (PNS) adrenergic neurons synthesize, transport, and store the serene protease, tissue plasminogen activator (t-PA) in axon terminals, many of which innervate vessel walls. Sympathoadrenal stimulation induces a surge of t-PA from vessel walls into the blood. The vascular endothelium, which constitutively secretes t-PA into blood also has long been widely assumed to be the principal source of this stress-induced release, but has not been verified as such. A neurologically regulated release from adrenergic stores could thus augment the known constitutive endothelial release. To functionally test this possibility, we quantitated the effects of guanethidine-induced systemic sympathectomy on the basal and stimulated release of t-PA from isolated vessel explants in superfused organ cultures. Moment-to-moment changes in the release rate were plotted from serial assays of the t-PA free activity. The effects of endothelial and adventitial nerve plexus ablations were also tested. Sympathectomy induced 30-50% reductions in t-PA release from both arterial and microvascular explants. An acute release induced by alpha-1 adrenergic receptor stimulations was also strongly suppressed, as were basal levels of the circulating enzyme in vivo. Adventitial and endothelial ablations from normal large vessel explants produced greater reductions than small vessel endothelial ablations. Ganglion electrical stimulation also induced an acute microvascular release in vivo. These and past morphologic findings indicate a physiological infusion of t-PA into the vessel walls, blood, and other innervated matrices by sympathetic neurons. Copyright 1999 Wiley-Liss, Inc. Comments: An exciting paper relating nerve function to clotting factors and revealing another means whereby diabetic neuropathy may promote vascular disease. Here we see also that the adventitia is more than a mechanical supporting structure.

Ren S, Shen GX: Impact of antioxidants and HDL on glycated LDL-induced generation of fibrinolytic regulators from vascular endothelial cells. Arterioscler Thromb Vasc Biol 20:1688-93, 2000. Hyperglycemia and dyslipoproteinemia are biochemical markers of diabetes mellitus (DM). Elevated levels of plasminogen activator inhibitor-1 (PAI-1) with and without reduction of tissue plasminogen activator (tPA) in plasma have been frequently found in patients with DM. Our previous studies indicated that glycation enhances low density lipoprotein (LDL)-induced production of PAI-1 and further decreases tPA generation in vascular endothelial cells (ECs). The present study demonstrated that treatment with antioxidants, butylated hydroxytoluene or vitamin E, blocked native LDL- and glycated LDL-induced changes in PAI-1 and tPA generation in ECs. Native or glycated high density lipoprotein (HDL) did not significantly alter tPA generation in ECs. Glycated but not native HDL (>/=100 microg/mL) moderately increased PAI-1 release from ECs. Cotreatment with native or glycated HDL inhibited LDL-induced or glycated LDL-induced changes in PAI-1 and tPA generation in ECs. The abundance of conjugated dienes was increased in glycated or EC-modified LDL. Treatment with butylated hydroxytoluene, vitamin E, or HDL reduced the abundance of conjugated dienes in glycated or EC-modified LDL. The effects of antioxidants and HDL on LDL-induced or its glycated LDL-induced changes in the generation of PAI-1 and tPA were also found in cultured human coronary artery ECs. The findings of the present study suggest that antioxidants and HDL may attenuate native LDL- or glycated LDL-induced changes in the generation of fibrinolytic regulators from vascular ECs, which possibly results from their inhibition on the lipid peroxidation of LDL particles. Treatment with antioxidants or hypolipidemic agents potentially improves fibrinolytic activity and reduces thrombotic tendencies in patients with DM. Comments: See Zhang and Rey below.

Ridker PM, Glynn RJ, Miletich JP, Goldhaber SZ, Stampfer MJ and Hennekens CH: Age-specific rates of venous thromboembolism among heterozygous carriers of factor V Leiden mutation. Ann Intern Med 126:528-31, 1997. While for most genetically influenced disorders it is commonly assumed that affected persons have clinical events at a younger age than do noninfected persons, the authors here show a significantly greater increase of venous thromboembolism with increasing age.

Rubanyi GM, Romero JC, Vanhoutte PM:Flow-induced release of endothelium-derived relaxing factor. Am J Physiol 250:1145-1149, 1986. To analyze the potential mediator(s) involved in flow-induced endothelium-dependent vasodilatation, we measured the wall tension of intraluminally perfused canine femoral artery segments and compared the content of 6-ketoprostaglandin F1( (determined by radioimmunoassay) and relaxing activity of the effluent (determined by bioassay on canine coronary artery rings). During perfusion at a steady flow of 2 ml/min the effluent contained 6-ketoprostaglandin F1( and relaxed the bioassay rings. Sudden increase in steady flow rate to 4 ml/min, or the introduction of pulsatile flow, increased the release of 6-ketoprostaglandin F1( and induced further relaxations of the bioassay ring. No relaxations were observed with the effluent passing through a femoral artery segment without endothelium. Indomethacin significantly depressed the release of 6-ketoprostaglandin F1( during increases in flow but had no significant effect on the relaxing activity of the effluent. In the presence of indomethacin, increases in flow produced significant relaxation in the perfused femoral artery segments with endothelium. Superoxide dismutase restored relaxing activity of the effluent during increases in flow at a transit time of 30 seconds. These data demonstrate that in addition to prostacyclin, flow triggers the release of another relaxing substance (or substances) from vascular endothelial cells that has the characteristics similar to the endothelial-derived relaxing factor released by acetylcholine. Comments: We believe (?hope) that the rapid pulsations of the Circulator Boots promote the release of these vascular factors helping to produce increases in flow both in the area being pumped and in remote vascular beds (heart, brain and kidney).

Salomon O, Huna-Baron R, Moisseiev J, Rosenberg N, Rubovitz A, Steinberg DM, Davidson J, Sela BA, Seligsohn U: Thrombophilia as a cause for central and branch retinal artery occlusion in patients without an apparent embolic source. Eye 2001 Aug;15(Pt 4):511-4, 2001. PURPOSE: To assess the prevalence of vascular risk factors and thrombophilias in central and branch retinal artery occlusion in patients in whom an embolic source is not apparent. METHODS: The study group consisted of 21 consecutive patients with retinal artery occlusion (RAO) in whom Doppler ultrasonography of the carotid arteries and transthoracic or transoesophageal echocardiography were normal. Laboratory methods included polymerase chain reaction for detection of factor V G1691A, factor II G20210A and methylentetrahydrofolate reductase C677T mutations, assays of plasma levels of protein C, free protein S, antithrombin, fibrinogen and homocysteine; and tests for the presence of lupus anticoagulant and anticardiolipin antibodies. Controls for the laboratory tests were 243 healthy subjects. RESULTS: Nine of the 21 (43%) patients had at least one thrombophilic marker: 4 were homozygous for MTHFR C677T, 1 was heterozygous for factor V G1691A, 1 had a high titre of IgM anticardiolipin, 2 were heterozygous for factor V G1691A and homozygous for MTHFR C677T, and 1 had lupus anticoagulant, a high titre of IgM anticardiolipin, homozygosity for MTHFR C677T and hyperhomocysteinaemia. An interaction between vascular risk factors and thrombophilias seemed important since out of 14 patients with hypertension, diabetes and/or hypercholesterolaemia 7 (50%) had a thrombophilia. Homozygous MTHFR C677T was a significant risk factor with odds ratio of 3.18 (95% CI 1.20-8.47). The prevalence of factor V G1691A was also higher in the RAO patients versus controls with an odds ratio of 2.36 (95% CI 0.63-8.88), but this value did not reach significance, probably due to the small sample size. CONCLUSION: A search for thrombophilia in RAO is advisable in patients without evident source of emboli even when vascular risk factors are identified. Comments: Among our patients in the Case History section, one will find various patients with vascular occlusions in their retinal vessels that have improved with boot therapy. Would they have improved without our therapy? If he therapy helped , what did it do? These authors point our the complexity of the clotting problems that might be present in such patients

Salzman EW, McManama GP, Shapiro AH, Robertson LK, Donovan AS, Blume HW, Sweeney J, Kamm RD, Johnson MC and Black P McL: Effect of optimization of hemodynamics on fibrinolytic activity and antithrombotic efficacy of external pneumatic calf compression. Ann Surg 206: 636-641, 1987. Authors compared sequential application of graded pressure versus uniform pressure applied either to a segmented bladder or a single bladder. They found no significant difference in the prevention of venous thrombosis and concluded that if a larger study showed some benefit to a sequential apparatus, the benefit/cost of the more complex system was not likely to be great.

Sartori MT, Patrassi GM, Rigotti P, Marchini F, Fioretti M, Spiezia L, Girolami A: Improved fibrinolytic capacity after withdrawal of steroid immunosuppression in renal transplant recipients. Transplantation 69:2116-21, 2000. BACKGROUND: Long-term steroid immunosuppression has been associated with the prothrombotic state observed in renal transplant (RT) patients, in whom both hypercoagulability due to an increase of von Willebrand factor/factor VIII complex, and impaired fibrinolysis due to PAI-1 excess have been demonstrated. Our aim was to investigate the effect of steroid withdrawal on fibrinolytic capacity in a group of RT patients. METHODS: The fibrinolytic study was performed in 28 RT patients under stable immunosuppression therapy with cyclosporine, azathioprine, and methylprednisolone; only 12 of these patients could repeat the study