Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0011849 (diabetes)
 277,896 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Ticlopidine is an inhibitor of platelet action that has been used in the treatment of a variety of disease states in which platelets play a prominent role. Studies in animals and man have demonstrated that ticlopidine is a potent inhibitor of platelet aggregation induced by adenosine diphosphate (ADP), and variably inhibits aggregation due to collagen, adrenaline (epinephrine), arachidonic acid, thrombin, and platelet activating factor. Inhibition of platelet aggregation is both dose- and time-related, with its onset of activity being 24 to 48 hours, its maximal activity occurring after 3 to 5 days, and its activity still being present 72 hours after a final dose. Ticlopidine also inhibits the release reaction of platelets, prolongs bleeding time, reduces plasma levels of platelet factor 4 and beta-thromboglobulin in patients in whom these proteins are elevated, and may also inhibit platelet adhesion, increase red cell filtrability and decrease whole blood viscosity. In a large number of animal models, ticlopidine markedly inhibits thrombus formation or graft occlusion. Ticlopidine is well absorbed after oral administration. It is extensively metabolised and at least one of its metabolites is pharmacologically active. Therapeutic trials in patients with chronic arterial occlusion due to thrombangitis obliterans or arteriosclerosis obliterans, post-myocardial infarction, cerebrovascular thromboembolic disease, subarachnoid haemorrhage, vascular shunts or fistulas for haemodialysis, and sickle cell disease have shown promise for the use of ticlopidine. However, trials of patients with intermittent claudication, angina pectoris, diabetes mellitus with microvascular disease, aortocoronary bypass grafts, and vascular prostheses have had conflicting results or have shown an unfavourable side effect profile. Further studies are clearly required to establish the role of ticlopidine in many of these areas, some of which are already in progress. Overall, side effects occur in 10 to 15% of patients receiving ticlopidine. The most common side effects are gastrointestinal disturbances and skin rashes. Neither of these necessarily require discontinuation of therapy in most patients. Agranulocytosis, thrombocytopenia, and cholestatic jaundice have also been reported. Bleeding is infrequent except possibly in patients receiving ticlopidine prior to some surgical procedures.
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PMID:Ticlopidine. A review of its pharmacodynamic and pharmacokinetic properties, and therapeutic efficacy in platelet-dependent disease states. 330 67

Plasma fibrinopeptide A (FPA) concentration, as a measure of thrombin activity, was determined during an insulin tolerance test in 17 non-obese diabetics. FPA was measured by a modification of the Nossel method. Administration of insulin significantly lowered plasma glucose, accompanied by a significant increase in FPA from 0.9 +/- 0.1 ng/ml to 4.3 +/- 1.6 ng/ml (P less than 0.05) as well as a significant increase in circulating levels of epinephrine and growth hormone. The magnitude of the peak in epinephrine levels correlated well with both the rate of decline of plasma glucose and the magnitude of the peak of FPA. In addition, the FPA increment was suppressed by treatment with heparin. These results indicate that insulin-induced hypoglycemia or a rapid fall in plasma glucose is associated with enhanced thrombin generation and fibrin formation, which may be considered as a contributory factor to the development of diabetic microangiopathy through a hypercoagulable state.
Diabetes Res Clin Pract 1987 Nov
PMID:Plasma fibrinopeptide A levels during insulin-induced plasma glucose falls in diabetics. 331 68

The effect of nonenzymatic glycosylation on the kinetics and structure-function relationships of antithrombin III were investigated at normal physiologic concentrations of antithrombin III and glucose, which are 5.2 microM and 5 mM, respectively. The results were compared with antithrombin III incubated at the glucose concentration expected to be found in severely diabetic patients (15 mM). Antithrombin III incubated at 5 mM lost 33% of the heparin cofactor activity after 7 days, whereas antithrombin III incubated at 15 mM lost 50% for the same period. Under both conditions, half of the heparin cofactor activity was lost after 15 days. When D-[U-14C]glucose was used as tracer, approximately 0.6 mol glucose/mol protein was incorporated after 10 days at both concentrations of glucose. A detailed evaluation of the kinetics of inhibition of thrombin by glycosylated antithrombin III revealed that the second-order rate constant is three times smaller than that of normal antithrombin III. On the basis of these data, it is concluded that glycosylated antithrombin III with 50% depressed heparin cofactor activity is three times weaker than normal antithrombin III as an inhibitor of thrombin. The implications of these observations with respect to the possible pathogenesis of thrombosis in diabetes are discussed.
Diabetes 1988 Aug
PMID:Demonstration of altered antithrombin III activity due to nonenzymatic glycosylation at glucose concentration expected to be encountered in severely diabetic patients. 339 45

Vitamin E content and biosynthesis of 12-hydroxyeicosatetraenoic acid (12-HETE) have been measured in platelets from type I diabetic subjects and age- and sex-matched, nondiabetic control subjects. Platelets from diabetic subjects synthesized significantly greater quantities of 12-HETE than did platelets from control subjects when 12-HETE synthesis was induced by thrombin or collagen, either in the presence or absence of indomethacin. Platelet conversion of exogenously added arachidonic acid (AA) to 12-HETE was not significantly different between the diabetic and control groups in the absence of indomethacin, although a small but significant increase in the conversion of AA to 12-HETE was present in the diabetic group platelets when indomethacin was added to the reaction. Vitamin E content was significantly reduced in platelets from the diabetic subjects, when compared with platelets from the control subjects, although plasma vitamin E levels were not significantly different between the two groups. Thrombin- and collagen-induced platelet 12-HETE synthesis demonstrated a significant negative linear correlation with platelet vitamin E content when measurements from both diabetic and control groups were combined. The above data suggest a relationship between low vitamin E content and increased 12-HETE synthesis in platelets from type I diabetic subjects.
Diabetes 1985 Jun
PMID:Production of 12-hydroxyeicosatetraenoic acid and vitamin E status in platelets from type I human diabetic subjects. 392 90

Diabetes mellitus is associated with altered platelet function and endothelial damage, but their relationship remains unclear. We examined the effect of short-term metabolic control with insulin in 14- and 28-day streptozocin-induced diabetic rats on alterations in in vitro platelet aggregation and serotonin release. Endothelial damage was assessed by plasma concentrations of von Willebrand factor activity (VIIIR:WF) and factor VIII-related antigen (VIIIR:Ag). Insulin was administered for 5 or 7 days at 9 or 21 days, respectively, after streptozocin. Enhanced platelet aggregation responses to adenosine diphosphate (ADP) and thrombin occurred after both durations of diabetes. Insulin therapy returned ADP-induced, but not thrombin-induced, responses to normal. Enhanced thrombin-induced platelet release of serotonin occurred at both times. Collagen-induced platelet release was enhanced in 28-day diabetic rats. Insulin therapy returned these responses to normal. Plasma concentrations of VIIIR:WF and VIIIR:Ag were elevated in 28-day, but only VIIIR:WF was elevated in 14-day diabetic rats. Insulin therapy reduced the elevated levels of VIIIR:Ag in 28-day diabetic rats, but had little effect on either parameter after the shorter duration of diabetes. In summary, Enhanced platelet aggregation and increased release of serotonin occur shortly after the induction of diabetes by streptozocin in adult rats. These platelet changes precede alterations of endothelial function, as determined by plasma VIIIR:WF and VIIIR:Ag levels. Platelet changes respond more rapidly to insulin therapy than do endothelial changes in diabetic rats. The duration of diabetes before insulin therapy does not affect these relationships.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Effect of insulin treatment in streptozocin-induced diabetic rats on in vitro platelet function and plasma von Willebrand factor activity and factor VIII-related antigen. 392 83

In an attempt to elucidate the nature of the bleeding tendency in uremia, some in vitro functions of platelets from eight patients undergoing long-term hemodialysis were studied. None of the patients had diabetes. All had bleeding times longer than eight minutes. Threshold aggregating concentrations for collagen, adenosine diphosphate, and epinephrine, when used singly or in pairs, were two to three times higher than normal in platelet-rich plasmas from these patients. In contrast, those for arachidonic acid and U-46619, a cyclic endoperoxide/thromboxane A2 analogue, were within the normal ranges. Thromboxane B2 formation was normal in response to arachidonic acid (0.2 to 1 mM), whereas it was decreased by 30 to 50 percent in response to thrombin (0.5 to 10 units/ml), collagen (0.5 to 10 micrograms/ml), and the combination of collagen with adenosine diphosphate or epinephrine. There was a partial (about 35 percent) reduction of the platelet granular content of adenosine diphosphate. Secretion of adenosine triphosphate by 5 units/ml of thrombin was 25 to 50 percent less than in normal subjects. Thus, there was a storage pool defect as well. Similar but less severe defects were found in platelets from uremic patients who had never undergone hemodialysis. Partial correction of aggregation and thromboxane B2 formation was seen after dialysis, although platelet adenosine diphosphate content did not increase. It is concluded that the platelet dysfunction in uremia is multifaceted. There appears to be an aggregation and secretion defect related to impaired arachidonic acid release from platelet phospholipids as well as a storage pool defect. The first is improved with dialysis; the second is not.
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PMID:Platelet dysfunction in uremia. Multifaceted defect partially corrected by dialysis. 393 40

While it is known that platelets from diabetic patients bind more fibrinogen than do platelets from normal subjects, there has been no study comparing this phenomenon in platelets from nonretinopathic and retinopathic patients. We have made such a comparison and have found the following. In agreement with previous reports, platelets from nonretinopathic diabetic patients bind abnormally high amounts of fibrinogen. No differences in the amount of fibrinogen bound to platelets (stimulated by collagen or thrombin) were found when data from nonretinopathic and retinopathic patients were compared. However, while aspirin (an inhibitor of thromboxane synthesis) reduced the abnormally high fibrinogen binding of platelets from nonretinopathic patients to normal control levels, it did not normalize the high fibrinogen binding of platelets from retinopathic diabetic patients. The combination of aspirin plus apyrase (an ADP scavenger) almost suppressed fibrinogen binding and aggregation of platelets from normal or nonretinopathic diabetic subjects, whereas it had a somewhat lesser effect on binding and aggregation of platelets from retinopathic subjects. By using a monoclonal antibody (B59.2) to the platelet receptor for fibrinogen, we determined that this receptor was the same in platelets from normal as well as nonretinopathic diabetic subjects and that this antibody could suppress the binding of fibrinogen and the aggregation of platelets from both types of patients just as it did in platelets from normal subjects. Thus, our data indicate that, while platelets from both retinopathic and nonretinopathic patients are hyperaggregable and show abnormally high binding of fibrinogen, they differ in that these abnormalities can be normalized in platelets from nonretinopathic patients by suppressing prostaglandin/thromboxane formation and scavenging ADP, but not in those from retinopathic patients.
Diabetes 1986 Feb
PMID:Platelet fibrinogen binding in diabetes mellitus. Differences between binding to platelets from nonretinopathic and retinopathic diabetic patients. 394 66

Plasma and urine fibrinopeptide-A (FPA) levels were investigated in type I and II diabetic patients. Plasma FPA and 24-h urinary excretion of FPA were significantly elevated in diabetic patients compared with normal volunteers, indicating augmented thrombin activity in diabetes. Plasma and urine FPA did not differ between type I and type II diabetic subjects. Comparison of plasma FPA with blood glucose and hemoglobin A1 (HbA1) indicated that elevation of FPA is rapidly reversible and intermittent during hypo- and hyperglycemia. Although elevated plasma FPA was seen in patients of short as well as long duration of diabetes, plasma and urine FPA correlated with duration of diabetes in type I patients. In type I diabetic patients with vascular complications, hyperglycemia induced by an oral glucose challenge was accompanied by elevation of plasma FPA and acceleration of fibrinogen disappearance. These responses were not seen when the patients were treated with intravenous (i.v.) heparin before the glucose challenge. In patients without vascular complications, there was also an acceleration of fibrinogen disappearance and a marginal (not statistically significant) elevation of plasma FPA seen after the FPA response observed in vascular disease patients. In all patients, induced hyperglycemia resulted in a decrease in hematocrit and hemoglobin (blood volume expansion) and an increase in pulse pressure indicating hemodynamic changes. The association of hyperglycemia and hemodynamic changes with augmented thrombin activity is consistent with a mechanism for fibrin formation and deposition based on endothelial injury and/or increased vascular permeability. Fibrin deposition due to such a mechanism may participate in the development of the vascular complications of diabetes.
Diabetes 1985 Sep
PMID:Fibrinopeptide-A in diabetes mellitus. Relation to levels of blood glucose, fibrinogen disappearance, and hemodynamic changes. 402 10

37 type 2 diabetic patients with no clinical evidence of retinopathy or vascular disease were studied at diagnosis and following control of hyperglycaemia for evidence of abnormalities of coagulation, fibrinolysis and platelet behaviour. 38% showed hyperactive platelets, demonstrating either in vitro hyperaggregability, circulating platelet aggregates, or raised plasma beta-thromboglobulin levels. 36% showed abnormally raised factor VIII coagulant activity (FVIIIc) levels, though this was mainly in female patients. The mean level of FVIIIc decreased with treatment. Anti-thrombin III (AT-III) levels were decreased, and 33% of the patients had levels less than 80%. In this group AT-III increased following treatment. No abnormalities of fibrinolysis were demonstrated. These findings support the concept that diabetes can be associated with a hypercoagulable state, which is not necessarily dependent on the presence of overt vascular disease, or correlated with the degree of chronic hyperglycaemia (HbA1c levels).
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PMID:Diabetes, a hypercoagulable state? Hemostatic variables in newly diagnosed type 2 diabetic patients. 621 31

Haemostasis was studied in 34 diabetic patients with and without detectable vascular complications (micro- and macroangiopathy). Information on platelet functions was obtained by beta-thromboglobulin determination, and of heparin-thrombin coagulation time, platelet aggregation in vivo, and on the condition of the vessel walls by estimation of factor VIII-protein (VIIIR:Ag). The results were suggestive of an increased platelet activity, the most marked abnormalities having been found in cases of angiopathy. Attention is drawn to the therapeutic possibilities offered by studies of the pathogenetic role of the abnormalities of haemostasis in diabetes.
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PMID:Haemostasis in diabetics. 623 79


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