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Biomedical subjects

D Mari

Publications and source records attributed to D Mari.

At least 55 records · Page 3Linked to original sources
PubMed1986

Pregnancy in women with different types of von Willebrand disease.

The course and outcome of pregnancy in women with different types of von Willebrand disease (3 type I, 1 subtype IIA, and 1 subtype IIB) are described. In all patients, factor VIII increased and reached normal levels before delivery, whereas the bleeding time remained prolonged; in subtypes IIA and IIB the abnormal multimeric structure of von Willebrand factor remained unchanged. Deliveries were uneventful in all patients, with two spontaneous vaginal deliveries and three cesarean sections, despite the fact that no replacement therapy was given. Hence, the most important determinant of abnormal hemorrhage during delivery is low factor VIII; the prolonged bleeding time can be compensated for by meticulous surgical hemostasis and efficient contraction of the uterus. Replacement therapy with plasma derivatives can usually be avoided providing that normal factor VIII levels have been attained at delivery.

Adult↗
PubMed1986

Controlled trial of desmopressin in liver cirrhosis and other conditions associated with a prolonged bleeding time.

The synthetic vasopressin derivative desmopressin (DDAVP) shortens a prolonged bleeding time (BT) in patients with uremia, congenital platelet dysfunction, and von Willebrand disease. To establish the limits of the clinical usefulness of DDAVP, a controlled randomized study was carried out in 53 patients and ten volunteers with different conditions that have in common a prolonged BT. DDAVP significantly shortened the BT in 21 cirrhotics (P less than .01), in eight patients with unclassified prolonged BT (P less than .05) and in ten volunteers taking the antiplatelet drugs aspirin (P less than .05) and ticlopidine. The BT changes were not statistically significant in 15 patients with severe thrombocytopenia nor in nine with congenital platelet dysfunction, even though a few patients with storage pool deficiency responded with a marked BT shortening. Our findings indicate that DDAVP might be given when biopsies or other surgical procedures must be carried out in patients with prolonged BT. However, the compound is often ineffective in patients with thrombocytopenia or congenital platelet dysfunction.

Adolescent↗
PubMed1985

Hemostatic alterations are unrelated to the stage of tumor in untreated malignant melanoma and breast carcinoma.

A study of hemostatic variables was carried out in 80 untreated patients with breast adenocarcinoma or malignant melanoma, chosen as examples of tumors that can be accurately staged for localization or spread. The most marked abnormalities were high levels of clotting factors V and VIII, plasminogen, von Willebrand factor and fibrogen-fibrin degradation products. These abnormalities occurred in both types of tumors, albeit slightly more markedly in melanomas, and were also present in localized tumors. Our data indicate that in tumors, abnormalities of the hemostatic system are an early phenomenon unrelated to the presence of widespread malignancy.

Adenocarcinoma↗
PubMed1985

[The role of erythrocyte deformability in the prolonged bleeding time in liver disease patients].

Hematocrit (Ht), red cell deformability (RCD) determined using a filtration method and bleeding time (BT) have been studied in 28 patients with severe chronic liver disease. Our results show a decrease of Ht (p less than 0.001), RCD (p less than 0.05) and a prolongation of BT (p less than 0.001) not related to the platelet count. Moreover, inverse relationships between Ht and BT (r = -0.52; p less than 0.01) and between RCD and BT (r = -0.54; p less than 0.01) have been found. We conclude that hemorheological alterations, such as decreased Ht and RCD, play an important role in primary hemostasis of patients with chronic liver disease.

Adult↗
PubMed1984

Abnormalities of lymphocyte subsets are correlated with concentrate consumption in asymptomatic Italian hemophiliacs treated with concentrates made from American plasma.

Eighty-three symptom-free hemophiliacs were studied clinically, serologically and by in vitro tests for cellular immunity in a geographical area in which AIDS has not yet been encountered despite the exclusive use of concentrates manufactured from American sources of plasma. Some patients showed the following abnormalities: lymphopenia (4%), decreased T-helper/T-suppressor (Th/Ts) cell ratios (49%), or both abnormalities (2%). Low Th/Ts were mostly due to absolute or, less frequently, relative increases in Ts cells. The prevalence rates for these abnormalities were the same in patients treated with factor VIII or factor IX concentrates. There was an association between the higher Ts and lower Th cells counts and the low Th/Ts ratios and greater annual consumption of factor VIII and factor IX concentrates. These results support the view that protein load might be an important pathogenetic factor in lymphocyte abnormalities in symptom-free hemophiliacs.

Acquired Immunodeficiency Syndrome↗
PubMed1983

[Fibrinolytic and defibrinogenation therapy].

Plasma fibrinogen is one of the main determinants of blood viscosity and is known to play an important role in the pathogenesis of venous and arterial thromboembolism. The pharmacological intervention on these factors can be achieved by lowering fibrinogen. Plasma fibrinogen concentrations can be lowered by fast-acting and slow-acting drugs. Among fast-acting drugs, fibrinolytic agents (such as streptokinase, urokinase, brinase and plasmin) act by cleaving FGN directly or indirectly through the formation of the proteolytic enzyme plasmin. Defibrinogenating agents (ancrod and batroxobin) are thrombin-like enzymes which induce the in vivo formation of fibrin microclots characterized by a peculiar physicochemical structure rendering them more easily cleared by the reticuloendothelial system. There is a clear-cut evidence for the clinical efficacy of fast-acting FGN-lowering drugs in the prevention and treatment of a number of clinical conditions associated with thromboembolic manifestations. However, it is not well established to which extent the effectiveness is due to their action on blood viscosity rather than to their fibrinolytic and anticoagulant properties. Slow-acting drugs (such as anabolic steroids, clofibrate, ticlopidine and pentoxifylline) decrease plasma FGN less rapidly and to a smaller extent than fast-acting drugs. Unlike these, they can be employed in long-term treatments. Clinical trials have clearly shown their clinical efficacy in a number of conditions associated with an altered microcirculation (Raynaud's syndrome, liposclerosis and postphlebitic syndrome). Their effect on blood viscosity is likely to be an important determinant of the clinical efficacy of these drugs.

Ancrod↗
PubMed1982

Coagulation and platelet activation after retinal vein occlusions.

The role played by coagulation and platelet activation in the pathogenesis of retinal vein occlusions (RVO) has been evaluated by measuring beta-thromboglobulin (B-TG), circulating platelet aggregates (CPA), thromboxane B2 (TxB2) and fibrinopeptide A (FPA) in 25 patients less than 40 years old, investigated after the acute phase of RVO. FPA nd B-TG were significantly higher than in healthy subjects; CPA and TxB2 were not different. These abnormalities, found in patients free from apparent generalized vascular disease, suggest that a thrombophilic state characterized by coagulation and platelet activation is present in a high proportion of young patients with RVO.

Adolescent↗
PubMed1981

[Retinal vascular changes and haemostatic function in young patients (author's transl)].

Haemostatic function was studied in 40 patients between one and 12 months from the occurrence of retinal vein occlusion (RVO); 25 patients aged 40 years, or less and 15 were more than 45 years old. The following tests were performed : plasma beta-thromboglobuline (beta-TG) fibrinopeptide A (FpA), PTT, spontaneous in vitro platelet aggregation (SpA), circulating platelet aggregates (CPA), platelet retention (PR) to glass beads, serum thromboxane B2 (TxB2). In the group of older patients, there was a significant increase of beta-TG, FpA, PR, SPA, TxB2, and a reduction in the PTT. CPA was not significantly changed. In the group of younger patients (less than 40 yrs) only FpA and beta TG levels showed significant differences from the control group of age-matched healthy subjects. These findings suggest that the alterations present in older patients are likely to be secondary to generalized vascular damage, whereas a state of activation of the coagulation system appears to be present in younger patients with RVO.

Adult↗
PubMed1979

The varied sensitivity of partial thromboplastin and prothrombin time reagents in the demonstration of the lupus-like anticoagulant.

An acquired inhibitor of blood coagulation, similar to that described in patients with Systemic Lupus Erythematosus (SLE), was detected during routine coagulation screening in 10 patients who did not meet the criteria for a diagnosis of SLE. The lupus-like anticoagulant (LLAC) was diagnosed on the basis of prolonged activated partial thromboplastin time (APTT) and/or prothrombin time (PT) which failed to correct when patient plasma was added to normal plasma; an additional criterion was an abnormal tissue thromboplastin inhibition test. No patient had a specific inhibitor directed against factors VIII and IX. Demonstration of LLAC was highly dependent upon the type of reagents adopted in the APTT and PT: the abnormality was detected consistently by one reagent only. One-stage assays of factors VIII and IX were characteristic of the presence of an inhibitor, showing non-parellel dose-response curves or decreased activity at low dilutions which were partially corrected at higher dilutions. Although 7 patients were free of abnormal bleeding, unequivocal signs of haemorrhagic tendency after a surgery were present in the remaining 3 patients. The findings suggest that LLAC is a non-exceptional cause of prolonged coagulation screening tests, and that it may sometimes be associated with impaired haemostasis.

Adolescent↗