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Biomedical subjects

A Quatraro

Publications and source records attributed to A Quatraro.

At least 37 records · Page 2Linked to original sources

Protein C deficiency in insulin-dependent diabetes: a hyperglycemia-related phenomenon.

In 30 insulin-dependent diabetic patients protein C (PC) antigen and PC activity were significantly lower than those of matched control healthy subjects. An inverse correlation between fasting plasma glucose and both PC concentration and activity was present in diabetics, while a direct correlation between PC concentration and PC activity was observed. Induced hyperglycemia in diabetic and normal subjects was able to decrease both PC antigen levels and PC activity, and heparin reversed in part this effect. In diabetic patients euglycemia obtained by insulin infusion restored to normal the depressed PC levels. Heparin did not alter both the basal PC concentration and activity in healthy controls. These data stress the major role of hyperglycemia in determining PC decrease in diabetics, and suggest that PC reduction is probably associated to hyperglycemia-enhanced thrombin formation.

Adult↗

Hydroxychloroquine in decompensated, treatment-refractory noninsulin-dependent diabetes mellitus. A new job for an old drug?

STUDY OBJECTIVE: To evaluate the usefulness and safety of hydroxychloroquine in patients with decompensated, treatment-refractory noninsulin-dependent diabetes mellitus. DESIGN: Prospective, randomized, placebo, double-blind 6-month trial. PATIENTS: Thirty-eight patients with noninsulin-dependent diabetes resistant to commonly used therapies (oral drugs, insulin, combination of insulin and oral drugs). INTERVENTIONS: Two study groups: one received insulin (n = 22) and the other, glibenclamide (n = 16). In each group, half of the patients were randomly allocated into two subgroups who continued the previous treatment but took either placebo tablets or hydroxychloroquine, 200 mg three times a day. The four subgroups were as follows: insulin and placebo (n = 11); insulin and hydroxychloroquine (n = 11); glibenclamide and placebo (n = 8); and glibenclamide and hydroxychloroquine (n = 8). MEASUREMENTS AND MAIN RESULTS: At 6 months, relevant and statistically significant improvement occurred in the 11 patients who received the insulin and hydroxychloroquine (glucose profile decrease, -11.7 mmol/L; 95% CI, -13.9 to -9.5, P = 0.001; glycated hemoglobin A1c decrease, -3.3%; 95% CI, -3.9 to -2.7, P = 0.001). No significant changes were seen in patients on placebo. The daily insulin dose in patients treated with the combined insulin and hydroxychloroquine therapy had to be reduced an average of 30%. No important side effects were detected. CONCLUSIONS: Combining antidiabetic therapy with hydroxychloroquine in decompensated, treatment-refractory patients with noninsulin-dependent diabetes may help to break the vicious circle of hyperglycemia and lead to better management of the disease.

Adult↗

Evidence for a hyperglycaemia-dependent decrease of antithrombin III-thrombin complex formation in humans.

In the presence of increased levels of fibrinopeptide A, decreased antithrombin III biological activity, and thrombin-antithrombin III complex levels are seen in diabetic patients. Induced-hyperglycaemia in diabetic and normal subjects decreased antithrombin III activity and thrombin-antithrombin III levels, and increased fibrinopeptide A plasma levels, while antithrombin III concentration did not change; heparin was shown to reduced these phenomena. In diabetic patients, euglycaemia induced by insulin infusion restored antithrombin III activity, thrombin-antithrombin III complex and fibrinopeptide A concentrations; heparin administration had the same effects. These data stress the role of a hyperglycaemia-dependent decrease of antithrombin III activity in precipitating thrombin hyperactivity in diabetes mellitus.

Adult↗

Non-enzymatic glycation reduces heparin cofactor II anti-thrombin activity.

The effects of non-enzymatic glycation on heparin cofactor II activity, at glucose concentrations which might be expected in physiological or diabetic conditions have been evaluated in this study. Radiolabelled glucose incorporation was associated with a loss of heparin cofactor anti-thrombin activity. The heparin cofactor heparin and dermatan sulfate-dependent inhibition of thrombin was significantly reduced, showing a remarkable decrease of the maximum second order rate constant. This study shows that heparin cofactor can be glycated at glucose concentrations found in the blood, and that this phenomenon produces a loss of heparin cofactor-antithrombin activity. These data suggest, furthermore, a possible link between heparin cofactor glycation and the pathogenesis of thrombosis in diabetes mellitus.

Antithrombins↗

The role of hyperglycaemia-induced alterations of antithrombin III and factor X activation in the thrombin hyperactivity of diabetes mellitus.

Factor X concentration and factor X activation, antithrombin III anti-Xa activity and plasma concentration, and fibrinopeptide A were measured in 20 diabetic patients and 20 normal subjects. Although factor X activation (81.3 +/- 2.2 vs 97.3 +/- 2.1%, p less than 0.01; mean +/- SE) and antithrombin III activity (76.5 +/- 2.2 vs 96.3 +/- 1.8%, p less than 0.01) were reduced in the diabetic patients, fibrinopeptide A concentration was increased (3.7 +/- 0.4 vs 1.7 +/- 0.2 ng ml-1, p less than 0.01). The ratio of factor X activation to antithrombin III anti-factor Xa activity was increased in the diabetic patients (1.10 +/- 0.01 vs 1.01 +/- 0.02, p less than 0.01). Induced hyperglycaemia was able to mimic all these abnormalities, without changing factor X or antithrombin III concentration. The results suggest that in vivo hyperglycaemia produces a decrease of factor X activation, but at the same time increases fibrinopeptide A formation due to a greater decrease of antithrombin III anti-Xa activity.

Adult↗

Evidence for a reduced heparin cofactor II biological activity in diabetes.

A reduction of heparin cofactor II (HCII) biological activity, despite its normal plasma concentration, is reported in insulin-dependent diabetic patients. A good linear correlation between HCII activity and concentration is present in normal controls but not in diabetics. In these subjects HCII activity correlates inversely with fasting blood glucose and glycated proteins but not with Hb A1. These data demonstrate the presence of a depressed HCII activity in the presence of its normal plasma concentration in insulin-dependent diabetics and suggest a role for short-term metabolic control in conditioning this phenomenon.

Adult↗

Possible role for increased C4b-binding-protein level in acquired protein S deficiency in type I diabetes.

In this study, total protein S (PS) immunological levels, free-PS and C4b-binding-protein (C4bBP) concentrations, and PS functional activity were investigated in insulin-dependent (type I) diabetic patients and compared with nondiabetic subjects. Mean total PS antigen concentration was not different between diabetic patients and nondiabetic subjects, whereas free-PS levels and PS functional activity were significantly reduced in diabetic patients. C4bBP was increased in diabetic patients and correlated with HbA1 levels. This study shows that type I diabetic patients have depressed free PS and PS activity despite the presence of normal total PS concentration and suggests that this phenomenon is probably linked to the increase of circulating C4bBP.

Adult↗

Hyperglycemia may determine fibrinopeptide A plasma level increase in humans.

The effects of hyperglycemia on plasma fibrinopeptide A (FPA) levels in normal subjects are reported. An increase of FPA concentration parallel to sustained hyperglycemia was observed; when the glycemia returned to basal values, FPA showed values in normal range. Heparin infusion was able to significantly decrease the hyperglycemia-induced augment of FPA levels. Isovolumic-isotonic NaCl solution infusion produced a slight (NS) increase in FPA levels; however, mild hyperglycemia, achieved by glucagon, was also able to produce a significant increase in FPA concentration. These data demonstrate the direct role of hyperglycemia in conditioning FPA level, and suggest that hyperglycemia, by itself, is a sufficient stimulus to produce thrombin activation in humans.

Adult↗

Hyperglycemia-conditioned increase in alpha-2-macroglobulin in healthy normal subjects: a phenomenon correlated with deficient antithrombin III activity.

Induced hyperglycemia in normal subjects increases alpha 2-macroglobulin (alpha 2M) activity and alpha 2M concentration and reduces antithrombin III (ATIII) activity, while it does not affect ATIII plasma concentration. Hyperglycemia-determined variations in ATIII activity and alpha 2M molecules are correlated in an inverse and parallel fashion. A compensatory role for the increase in alpha 2M in the regulation of the coagulation system may be hypothesized. Moreover, these data provide evidence that hyperglycemia may decrease, directly, the biological function of some proteins and may influence the levels of some risk factors for the development of complications in diabetes.

Adult↗

Blood glucose may condition factor VII levels in diabetic and normal subjects.

Increased factor VII levels have been reported in Type 1 (insulin-dependent) diabetic subjects. A direct correlation between fasting plasma glucose and factor VII level was found to exist in both diabetic and normal subjects. Induced-hyperglycaemia was able to increase factor VII levels in both diabetic patients and normal control subjects while, when euglycaemia was achieved in diabetic patients, factor VII values returned to normal range. This study shows that the level of factor VII may be directly conditioned by circulating blood glucose and, therefore, stresses the role of hyperglycaemia in conditioning coagulation abnormalities in diabetes mellitus.

Adult↗

Inhibitory effect of enkephalin on insulin secretion in healthy subjects and in non insulin-dependent diabetic subjects.

The administration of the long-acting met-enkephalin analogue (FK 33-824, Sandoz; Basel Switzerland) inhibits insulin secretion induced by glucose (oral and intravenous) and nonglucose (arginine and breakfast) secretagogues in both normal subjects and in patients with noninsulin-dependent diabetes mellitus. The plasma glucose rise triggered by oral glucose and breakfast is reduced by FK in both groups of subjects, suggesting for the opioid peptide an effect in delaying glucose absorption. The data suggest a negative role for enkephalin in the regulation of insulin secretion in both normal and noninsulin-dependent diabetic subjects.

Adult↗

Impaired glucose metabolism in heroin and methadone users.

Plasma glucose and insulin responses to both oral and intravenous glucose stimulation were evaluated in heroin and methadone addicts, compared to healthy control subjects. Both groups of addicts had an altered response to oral and intravenous glucose load. These phenomena were linked to a reduced insulin response. Moreover, increased fasting insulin levels in both groups of addicts were observed. These data show that both heroin and methadone addiction may alter glucose metabolism, and, furthermore, stress the findings of similarities between opiate addicts and non-insulin dependent diabetics.

Adult↗