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Biomedical subjects

G Mameli

Publications and source records attributed to G Mameli.

At least 37 records · Page 2Linked to original sources
PubMed1990

Is the imbalance between thrombin and plasmin activity in diabetes related to the behaviour of antiplasmin activity?

The aim of this study was to evaluate the balance between thrombin and plasmin activity in a group of 79 diabetic patients (IDDM and NIDDM). For this purpose we determined fibrinopeptide A (FPA) and B beta 15-42, specific products of thrombin and plasmin activity. Moreover we investigated the behaviour of antithrombin III and alpha 2 antiplasmin, important inhibitors of blood coagulation and fibrinolysis. Results show an increase both in FPA and B beta 15-42 in IDDM and NIDDM patients when compared to healthy controls. However the ratio between B beta 15-42 and FPA was lower than in controls indicating an imbalance between thrombin and plasmin activity. Antithrombin III levels were not different from the controls and no correlation was found with Hb A1c. alpha 2 antiplasmin was found to be higher in IDDM when compared both with NIDDM and controls. A non linear correlation was found between Hb A1c and alpha 2 AP in both diabetic groups. We conclude that the imbalance between thrombin and plasmin activity may have a role in determining fibrin deposition. These subclinical abnormalities, unrelated to vascular complications and duration of the disease, may progressively contribute to the development of the vascular complications in diabetes.

Adolescent↗
PubMed1989

Evidence for a relationship between high fibrinogen levels and decreased thrombin activity in vivo in elderly subjects.

In order to investigate whether high fibrinogen levels were associated with elevated thrombin activity, we measured fibrinogen and fibrinopeptide A in 37 elderly healthy subjects ranging from 60 to 93 years. Fibrinogen levels (519.1 +/- 127.0 mg/dl) and fibrinopeptide A (5.9, 0.9-18.1 ng/ml) were significantly higher than in younger controls. A highly significant negative linear correlation was found between fibrinogen and fibrinopeptide A in the elderly subjects (p less than 0.01). However, a polynomial regression showed that this negative relationship was present at the fibrinogen levels ranging between 420 and 700 mg/dl. Our results suggest that high fibrinogen levels in elderly subjects do not necessarily mean that their thrombin activity is concomitantly increased.

Aged↗
PubMed1989

Thrombin activity and oral anticoagulant therapy: a preliminary study.

The aim of this work was to investigate whether the thrombin activity is related to the degree of anticoagulation induced by oral anticoagulants. Moreover, we tried to detect an optimal anticoagulation range at which the lowest possible thrombin activity can be reached. We investigated 28 patients (19 women and 9 men, mean age 54 +/- 9 years). Anticoagulation had been induced by acenocoumarol for at least 1 year before the beginning of this study. The degree of anticoagulation was monitored by the thrombotest coagulation method. The therapeutic range was 5-13%. The thrombin activity was measured by means of the fibrinopeptide A radioimmunological assay. In 15, 7, and 6 of the patients, thrombotest and fibrinopeptide A were carried out twice, once, and three times, respectively. Our results show first of all a significant positive relationship between thrombotest and fibrinopeptide A (p less than 0.001). Once this result was obtained, we tried to improve our identification of the behaviour of the thrombin activity in relation to the degree of anticoagulation assessed by thrombotest. For this purpose we employed a third-degree polynomial regression analysis which showed a better fit of the data. Since the curve became steeper from about 10% thrombotest levels, we divided the FPA values on the basis of thrombotest ranges. FPA values for the 14- to 25% thrombotest range were significantly different from those in the thrombotest range of 4-10%. Moreover, FPA levels in the 11 to 13% thrombotest range were significantly different from those in the thrombotest range of 4-10%. Our results suggest that a significant decrease in thrombin activity may be achieved only with a deep anticoagulation.

Acenocoumarol↗
PubMed1989

[Activity of the coagulation and fibrinolysis in non-insulin-dependent diabetes mellitus. In vivo study].

In vivo study of blood coagulation and fibrinolysis activities in non insulin dependent diabetes mellitus. The aim of the study was to investigate in vivo blood coagulation and fibrinolysis activities in a group of diabetic patients NIDDM with and without vascular complications. For this purpose we determined two sensitive indicators in vivo of blood coagulation and fibrinolytic activities such as fibrinopeptide A and B beta 15-42 respectively. Moreover, we computed the ratio between B beta 15-42 and fibrinopeptide A in order to investigate a possible imbalance in vivo between blood coagulation and fibrinolysis. Control groups were 15 healthy subjects and 28 non diabetic patients affected by atherosclerotic disease. Fibrinopeptide A and B beta values were significantly higher in the diabetic patients than controls but there was no difference between the former group and the atherosclerotic patients. Also, no correlation was found for FPA, B beta, B beta/FPAr and HbAlc, fructosamine and blood glucose levels. There was no difference in B beta, FPA and B beta/FPAr values for patients treated with insulin and for those treated with either hypoglycemic agents or diet. Our data indicate that in diabetic patients fibrinolysis activity is increased, but it cannot counterbalance thrombin activity which appears much more enhanced. Finally, the lack of correlation for FPA, B beta, B beta/FPAr and HbAlc, fructosamine and blood glucose suggests that blood coagulation and fibronolysis abnormalities are not related to the degree of blood glucose control.

Adult↗
PubMed1988

Fibrinogen and fibrinolytic activity in hyperthyroidism before and after antithyroid treatment.

Plasma concentration of fibrinogen and B beta 15-42, a specific product of fibrinogen metabolism induced by plasmin, were measured in a group of patients with untreated hyperthyroidism and in controls. Significantly increased plasma levels of both parameters were observed in hyperthyroid patients. The restoration of euthyroidism either by antithyroid drug or by radioiodine caused a significant decrease of fibrinogen and B beta 15-42. These data indicate that hyperthyroidism is another clinical condition associated with increased concentration of fibrinogen and B beta 15-42.

Adult↗
PubMed1988

Fibrinopeptide A and B beta 15-42 in liver cirrhosis.

In order to detect even minimal fibrinolysis activation in liver cirrhosis, we measured fibrinopeptide B beta 15-42 (B beta 15-42), an indicator of plasmin activity in vivo and alpha 2-antiplasmin (alpha 2-AP) in a group of cirrhotic patients. The second goal of this study was to investigate whether an increased fibrinolytic activity is related to a chronic disseminated intravascular coagulation. For this purpose we concomitantly measured fibrinopeptide A (FPA), marker of thrombin activity in vivo. Results show significantly higher levels of B beta 15-42 in cirrhotic patients than in control (p less than 0.01). In patients with high FPA levels we found significantly higher values than in patients with normal FPA (p less than 0.01). alpha 2-AP was lower in patients with high FPA levels than in patients with normal FPA (p less than 0.05). A significant negative correlation was found between FPA and alpha 2-AP only in patients with high FPA (p less than 0.05). There was no relationship between B beta 15-42 and FPA nor between B beta 15-42 and alpha 2-AP when all patients were considered. These findings confirm that in liver cirrhosis fibrinolysis activation may occur. The primary pathogenetic role of DIC may be important in this respect. However the lack of correlation between FPA and B beta 15-42 suggests that other pathogenetic factors may be involved in determining fibrinolysis activation.

Adult↗
PubMed1987

Relationship between elevated fibrinopeptide A levels and alpha-2-antiplasmin.

In order to investigate whether alpha 2-antiplasmin (alpha 2-AP) levels may be related to thrombin activity, we measured alpha 2-AP and fibrinopeptide A (FPA) in 51 patients with clinical conditions frequently associated with increased thrombin activity. The diagnoses were: atherosclerotic disease, chronic inflammatory disease and hematological neoplastic disease. A significant negative correlation was found between alpha 2-AP and FPA (p less than 0.01). When patients were divided into three subgroups on the basis of their FPA levels, a significant reduction in alpha 2-AP was found in patients with the highest FPA concentration (greater than 9 ng/ml). Accordingly, a significant negative relationship between alpha 2-AP and FPA was found only in this subgroup (p less than 0.01). Our data suggest that the partial consumption of alpha 2-AP in patients with elevated FPA levels may reflect a subclinical fibrinolysis activation secondary to increased thrombin activity.

Adolescent↗
PubMed1985

alpha 2 Antiplasmin and disseminated intravascular coagulation in liver cirrhosis.

Subnormal concentrations of alpha 2 Antiplasmin (alpha 2 AP) in liver cirrhosis may be due to an impaired hepatic synthesis and/or to a fibrinolysis activation in disseminated intravascular coagulation (DIC). In order to clarify this problem, in 26 cirrhotic patients (15 compensated and 11 decompensated) alpha 2 AP plasma activity and plasma Fibrinopeptide A (FPA) were measured. Serum albumin, p-Cholinesterase (p-CHE), Fibrinogen and Fibrinogen Degradation Products (FDP) were also carried out. Our data show that alpha 2 AP and FPA were equally abnormal in compensated and decompensated cirrhosis. The significant negative correlation obtained between alpha 2 AP and FPA as well as the lack of correlation between alpha 2 AP and albumin, alpha 2 AP and p-CHE in both groups suggests that, in our patients, alpha 2 AP decrease may be due to a fibrinolysis activation induced by a DIC which appears chronic since Fibrinogen and FDP were normal. These findings are in agreement with the results obtained in the four subgroups a posteriori selected on the basis of FPA levels: alpha 2 AP in subgroups with high FPA was significantly different from controls while it did not differ in subgroups with normal FPA.

Adult↗
PubMedDate not supplied

Controlled vitamin K content diet for improving the management of poorly controlled anticoagulated patients: a clinical practice proposal.

The aim of our study was to investigate the effect of a diet with a known vitamin K content on the monitor test for oral anticoagulant therapy. We studied 10 poorly controlled patients (7 women and 3 men, mean age 48 +/- 15 years) in therapy with acenocoumarol for at least 1 year. Another group of 10 poorly controlled patients was considered as a control group. After a baseline period, during which a free diet was allowed, patients were administered a diet with a controlled vitamin K content; in the same period, control subjects were not subjected to any dietary restriction. Thrombotest (Nyegaard, Oslo) was employed for monitoring oral anticoagulant therapy, with a therapeutic range between 2.3 and 4.8 INR. We found a significant difference by thrombotest between the percentages within the therapeutic range obtained before and during dietary treatment (p = 0.0001). The difference in percentages was -0.31 and the 95% CI, of the difference ranged from -0.45 to -0.17. No significant difference was shown in the control group in the same periods. Our data suggest that a diet with a controlled vitamin K content is effective in increasing the percentage of tests within the therapeutic range in patients with poorly controlled anticoagulation.

Acenocoumarol↗
PubMedDate not supplied

Fibrinopeptide A, prothrombin fragment 1 + 2, thrombin-antithrombin complex and D dimer before and after injection of a nonionic contrast medium (iohexol).

The principal aim of this study was to evaluate, on biochemical grounds, whether injection of a low-osmolar nonionic contrast medium (iohexol) can induce a prothrombotic state and/or a change in fibrinolysis. Fifteen patients were submitted to urographic examination and the assays listed below were performed: before the injection (T0), 1 h after (T1), and 24 h after (T24) the injection of the contrast medium. The following assays were performed: fibrinopeptide A (FPA), prothrombin fragment 1+2 (F1+2), thrombin-antithrombin complex (TAT) and D dimer (D-D). The assays were carried out on 6 of the patients to whom a saline infusion was administered. Only a mild statistically significant increase was found in FPA levels at 1 h after injection of the contrast medium (mean and CI 95%: T0 4.4, 3.7-5.5; T1 6.0, 4.9-9.1; p = 0.003). F1+2, TAT and D-D did not show any significant change after the injection. These findings show that after injection of iohexol, only a mild, though statistically significant, increase in FPA levels was observed as an expression of increased thrombin activity. In the absence of any significant increases in TAT, F 1+2 and D-D, we have no evidence of a prethrombotic state.

Adult↗
PubMedDate not supplied

[Streptococcus mitis endocarditis. Description of a clinical case].

The diagnostic iter of a case of Streptococcus mitis endocarditis is reported. Bacterial endocarditis was diagnosed in a 32-year-old patient following ultrasound cardiography and microbiological tests. The paper stresses the importance of ultrasound cardiography in the diagnosis of bacterial endocarditis.

Adult↗