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Biomedical subjects

M Cattaneo

Publications and source records attributed to M Cattaneo.

At least 73 records · Page 4Linked to original sources

Isolation of a pancreas-specific gene located on human chromosome 14q31: expression analysis in human pancreatic ductal carcinomas.

We have isolated a novel cDNA (SEL1L) that shows sequence similarities to SEL-1, a gene identified as an extragenic suppressor of the lin-12 hypomorphic mutant from Caenorhabditis elegans (7, 8). SEL1L exhibits a tissue-specific pattern of expression: a single poly(A)+ RNA species of 7.5 kb is abundantly expressed only in the pancreas of healthy individuals, whereas low to undetectable levels are observed in other adult and in some fetal tissues. Somatic hybrid panel and fluorescence in situ hybridization positioned this gene in the q31 band of human chromosome 14. The tissue-specific expression of this gene induced us to study its role in human pancreatic carcinomas. Our analysis revealed that 17% of adenocarcinomas of the pancreas did not express SEL1L to a detectable level; however, no gross genomic alterations were apparent in the few hundred kilobases of the relevant region.

Adult↗

Risk factors for deep venous thrombosis of the upper extremities.

BACKGROUND: Hypercoagulable states and triggering factors (surgery, trauma, immobilization, pregnancy, and use of oral contraceptives) are associated with an increased risk for deep venous thrombosis of the lower extremities. In contrast, risk factors for deep venous thrombosis of the upper extremities have not been identified. OBJECTIVE: To evaluate the prevalence of hypercoagulable states and triggering factors in patients with primary deep venous thrombosis of the upper extremities. DESIGN: Frequency-matched case-control study. SETTING: Hemophilia and thrombosis center at a university hospital. PATIENTS: 36 patients who had primary deep venous thrombosis of the upper extremities, 121 patients who had primary deep venous thrombosis of the lower extremities, and 108 healthy controls. Patients who had deep venous thrombosis of the lower extremities and study controls were frequency-matched by age, sex, geographic origin, and social status with patients who had deep venous thrombosis of the upper extremities. MEASUREMENTS: Resistance to activated protein C was evaluated by a clotting method based on the activated partial thromboplastin time. If test results were abnormal or borderline, DNA analysis for substitution in coagulation factor V gene was done. Antithrombin, protein C, protein S, antiphospholipid antibodies, and total plasma homocysteine levels were also measured. RESULTS: Prevalences of abnormalities of the natural anticoagulant system (9%) and hyperhomocysteinemia (6%) in patients who had deep venous thrombosis of the upper extremities were similar to prevalences of both factors in controls (6% and 7%, respectively) but lower than in patients who had deep venous thrombosis of the lower extremities (31% and 14%, respectively). Antiphospholipid antibodies were found only in patients who had venous thrombosis of the lower extremities (7%). The overall prevalence of hypercoagulable states in patients who had thrombosis of the upper extremities (15%) was similar to that in controls (12%) but was significantly lower than that in patients who had thrombosis of the lower extremities (56%). A recent history of strenuous exercise of muscles in the affected extremity was the most frequent triggering factor for patients who had deep venous thrombosis in the upper extremities (33%). CONCLUSIONS: This preliminary study indicates that the prevalence of hypercoagulable states is low in patients who have primary deep venous thrombosis of the upper extremities.

Adult↗

Hyperhomocysteinemia: a risk factor for arterial and venous thrombotic disease.

Patients with the rare homozygous hereditary defects of homocysteine metabolism that cause severe hyperhomocysteinemia and homocystinuria are at high risk of arterial and venous thrombosis. This prompted studies of the relationship between moderate hyperhomocysteinemia and thrombotic risk in the general population. In the last 2 decades, retrospective case-control studies and prospective cohort studies have demonstrated moderate hyperhomocysteinemia to be a frequent and independent risk factor for premature vascular disease in the coronary, cerebral, and peripheral arteries. More recently, the association of moderate hyperhomocysteinemia with venous thrombosis was shown in patients with early-onset or recurrent disease and in the general population. Genetic and environmental factors act in concert to cause moderate hyperhomocysteinemia. Since inadequate intake of folic acid, vitamin B12, or vitamin B6 are most frequently associated with hyperhomocysteinemia, dietary supplementation of these vitamins could have a tremendous impact on the epidemiology and natural history of arterial and venous thrombotic diseases.

Amino Acid Metabolism, Inborn Errors↗

Review of clinical experience of desmopressin in patients with congenital and acquired bleeding disorders.

This paper discusses clinical experience of the use of desmopressin in patients with either congenital or acquired bleeding disorders. The bleeding disorders reviewed herein are haemophilia A, von Willebrand's disease and platelet function disorders (congenital bleeding disorders); uraemia, liver cirrhosis and drug-induced bleeding (acquired bleeding disorders).

Deamino Arginine Vasopressin↗

The UK guidelines for the use of desmopressin in patients with von Willebrand's disease. Von Willebrand Working Party of the United Kingdom Haemophilia Centre Director's Organization.

A document entitled Guidelines for the Diagnosis and Management of von Willebrand's Disease was produced by the von Willebrand Working Party of the United Kingdom Haemophilia Centre Directors' Organization. Under the chairmanship of Dr Beverley Hunt, an independent board of haematologists and anaesthesiologists reviewed the use of a synthetic vasopressin analogue, desmopressin (DDAVP), in the management of patients with von Willebrand's disease. The Advisory Board considered that production of the guidelines was to be applauded, but that the contraindications for DDAVP were imprecisely defined and may thus be misleading. This paper summarizes the Advisory Board's discussion of the suggestions.

Deamino Arginine Vasopressin↗

A common mutation in the methylenetetrahydrofolate reductase gene (C677T) increases the risk for deep-vein thrombosis in patients with mutant factor V (factor V:Q506).

Hyperhomocysteinemia is a frequent risk factor for deep-vein thrombosis. A common mutation (C677T) in the gene encoding for methylenetetrahydrofolate reductase (MTHFR) is responsible, in the homozygous state, for decreased enzyme activity and mild hyperhomocysteinemia and is associated with increased risk for cardiovascular disease. We studied the prevalence of C677T MTHFR in 77 patients with deep-vein thrombosis and in 154 age- and sex-matched healthy control subjects. In the same individuals, we also evaluated the frequency of the coexistence of C677T MTHFR with mutant factor V:Q506, a common risk factor for deep-vein thrombosis. Sixteen patients (20.8%) and 35 control subjects (22.7%) were homozygous for the C677T MTHFR mutation (odds ratio [OR] = 0.8, 95% confidence interval [CI] = 0.4-2.0). Sixteen patients (20.8%) and 4 control subjects (2.6%) had factor V:Q506; of them, 10 patients and 3 control subjects had isolated factor V:Q506 (adjusted OR = 6.3, 95% CI = 1.6-25.3) and 6 patients and 1 control subject also had C677T MTHFR (adjusted OR = 17.3, 95% CI = 2.0-152.9). The OR for the coexistence of the two mutations was 65% to 75% higher than the expected joint effect calculated by either an additive (OR = 6.0) or multiplicative (OR = 4.4) model. The homozygous C677T mutation of MTHFR per se is not a risk factor for deep-vein thrombosis but increases the risk associated with factor V:Q506. Due to the high prevalence of C677T MTHFR, it is likely that previous studies, which did not look for this mutation, overestimated the relative risk of thrombosis associated with factor V:Q506 alone.

Adolescent↗

Low prevalence of factor V:Q506 in 41 patients with isolated pulmonary embolism.

In 70-80% of cases, pulmonary embolism is the consequence of lower extremity deep vein thrombosis. It has been demonstrated that the most common coagulation defect predisposing to venous thrombosis, resistance to activated protein C (APC), is not associated with an increased risk for pulmonary embolism, but the evidence was based on a functional assay to diagnose APC resistance and no information about concomitant deep vein thrombosis was provided. The aim of our study was to evaluate the prevalence of factor V:Q506, the gene mutation responsible for APC resistance, in patients with symptomatic non-fatal pulmonary embolism, whether or not associated with deep vein thrombosis. Patients with uncomplicated deep vein thrombosis and healthy controls were investigated as comparison groups. The overall prevalence of factor V:Q506 in 106 patients with pulmonary embolism was 12.3%, lower than that found in 106 patients with deep vein thrombosis (22.6%, OR 0.5, 95% CI 0.2-1.0) but significantly higher than that found in 212 healthy subjects taken as controls (2.8%, OR 4.8, 95% CI 1.8-13.0). In the 41 patients with isolated pulmonary embolism, i.e., without the presence of deep vein thrombosis, the prevalence was 4.9%, similar to that in controls (OR 1.8, 95% CI 0.3-9.6), while in the remaining 65 patients with pulmonary embolism associated with deep vein thrombosis the prevalence was significantly higher (16.9%, OR 5.5, 95% CI 2.0-15.8). In conclusion, the prevalence of factor V:Q506 is high in patients with pulmonary embolism associated with deep vein thrombosis, whereas in patients with isolated pulmonary embolism it is similar to that found in control subjects. This intriguing finding is of difficult interpretation and needs confirmation by further studies.

Adolescent↗

Deficiency of (33P)2MeS-ADP binding sites on platelets with secretion defect, normal granule stores and normal thromboxane A2 production. Evidence that ADP potentiates platelet secretion independently of the formation of large platelet aggregates and thromboxane A2 production.

By the term "Primary Secretion Defect" (PSD), we mean a common heterogeneous group of congenital defects of platelet secretion, characterized by a normal primary wave of platelet aggregation induced by ADP and other agonists, a normal concentration of platelet granule contents, and normal production of thromboxane A2. The biochemical abnormalities responsible for PSD are not well known. Since a secretion defect similar to PSD is found in platelets that are severely deficient of binding sites for the ADP analogue 2MeS-ADP and do not aggregate in response to ADP, we tested the hypothesis that PSD platelets have moderately decreased 2MeS-ADP binding sites, which may be sufficient for normal ADP-induced aggregation but not for potentiating platelet secretion. The specific binding of [33P]2MeS-ADP to platelets from 3 PSD patients (347, 443 and 490 sites/platelet; KD 2.8-3.9 nM) was lower than to platelets from 24 normal subjects (647 [530-1102]; KD = 3.8 [2.3-7.3]) (median [range]). Normal values were found in a fourth PSD patient (710; KD 3.7). The degree of inhibition of PGE1-induced cAMP increase by 0.1 microM ADP was lower in patients than in controls. The secretion induced by the endoperoxide analogue U46619 from normal, acetylsalicylic acid-treated platelets under conditions that prevented the formation of large aggregates was potentiated by 1 mumol/l ADP and inhibited by apyrase. These findings indicate that a partial deficiency of the platelet ADP receptor(s) might be responsible for the defect of platelet secretion in some PSD patients and that ADP potentiates platelet secretion independently of the formation of large aggregates and thromboxane A2 production.

Adenosine Diphosphate↗

Evaluation of the abnormal platelet function in von Willebrand disease by the blood filtration test.

We have evaluated platelet function in different subtypes of von Willebrand disease (vWD) by pushing blood through the capillary-sized channels of a glass filter. Patients, including those with type IIB vWD, showed lower than normal platelet retention and increased cumulative number of blood drops passing through the filter as a function of time. In contrast, shear-induced platelet aggregation, measured in the cone-and-plate viscometer, was paradoxically increased in type IIB patients. Treatment with 1-desamino-8-D-arginine vasopressin (DDAVP) tended to normalize the filter test in patients with type I-platelet normal and type I-platelet low vWD, but infusion of a factor VIII/von Willebrand factor (vWF) concentrate lacking the largest vWF multimers was without effect in type 3 patients. Experiments with specific monoclonal antibodies demonstrated that the A1 and A3 domains of vWF, as well as the glycoproteins Ib alpha and IIb-IIIa on platelets, are required for platelet retention in the filter. Thus, the test may reflect vWF function with regard to both platelet adhesion and aggregation under high shear stress, and provide relevant information on mechanisms involved in primary hemostasis.

Adolescent↗

[Prevention of thromboembolism in atrial fibrillation of non-valvular etiology].

Atrial fibrillation is an independent risk factor for cerebral and systemic embolism. The risk increases with the patient's age and the presence of other risk factors: hypertension, diabetes, cardiac failure, prior transient ischemic attacks or embolic stroke. Risk stratification is of essential importance to allow the choice of the most suitable prophylaxis with antithrombotic drugs for the individual patient. On the basis of the results of controlled clinical trials, it is possible to suggest the following guidelines: a) in patients at low risk (< 65 years, with no other risk factor) the drug of first choice should be acetylsalicylic acid; b) in patients at high risk (> 65 years, with one or more risk factors) the drugs of first choice are oral anticoagulants, given at doses that prolong the prothrombin time to INR values of 2-3; c) in patients at high risk with contraindications to oral anticoagulants, acetylsalicylic acid or indobufen (shown to be as effective as oral anticoagulants in patients with prior transient ischemic attacks or stroke) should be considered.

Anticoagulants↗

Thrombin generation and activity during thrombolysis and concomitant heparin therapy in patients with acute myocardial infarction.

OBJECTIVES: This prospective study investigated the behavior of thrombin generation and activity during thrombolysis and concomitant heparin administration. BACKGROUND: It has been shown that during thrombolytic therapy there is an increase in thrombin generation and activity. Increased thrombin activity is suppressed by concomitant intravenous heparin, but it is unknown whether thrombin generation is also affected. METHODS: Thrombin generation was assessed by measuring prothrombin fragment 1 + 2 and thrombin-antithrombin complex plasma levels and thrombin activity by measuring fibrinopeptide A plasma levels. Serial blood samples were obtained before and at 90 min and 24 and 48 h after the administration of streptokinase (15 patients), recombinant tissue-type plasminogen activator (15 patients) or anistreplase (13 patients). An intravenous bolus of heparin (5,000 IU) was administered before the start of thrombolytic therapy, followed by an infusion of 1,000 U/h to maintain an activated partial thromboplastin time > 1.5 times baseline. RESULTS: During thrombolytic and concomitant heparin therapy, there was an increase in the plasma levels of prothrombin fragment 1 + 2 (baseline 1.08 vs. 2.73 nmol/liter, p < 0.001) and thrombin-antithrombin complex (baseline 6.5 vs. 17.1 micrograms/ml, p < 0.01) at 90 min, whereas no change was observed in fibrinopeptide A at 90 min (baseline 2.8 vs. 3.0 nmol/liter, p = NS). CONCLUSIONS: During thrombolytic therapy with both fibrin-specific and non-fibrin-specific drugs, there is an increase in thrombin generation despite concomitant administration of intravenous heparin.

Aged↗

Purinoceptors on blood platelets: further pharmacological and clinical evidence to suggest the presence of two ADP receptors.

Platelet aggregation by ADP plays a major role in the development and extension of arterial thrombosis. The antithrombotic thienopyridine compounds ticlopidine and clopidogrel have proved useful tools to investigate the mechanisms of ADP-induced platelet activation. In essence, although clopidogrel has been shown to completely and selectively block ADP-induced platelet aggregation, G protein activation and inhibition of adenylyl cyclase, this drug does not affect shape change and Ca2+ influx. Binding studies, using the non-hydrolysable ligand [33P]2MeSADP, have shown that human platelets contain about 600 high-affinity binding sites for 2MeSADP (Kd approximately 5 nM). These sites present pharmacological characteristics of a P2T receptor. Clopidogrel treatment reduces the number of sites by 70% on rat platelets (from 1200 to 450) and leaves the residual binding sites resistant to clopidogrel. Moreover, patients with congenital impairment of ADP-induced platelet aggregation but normal shape change display very low levels of [33P]2MeSADP binding sites. The current data thus strongly suggest the presence of two ADP receptors, one responsible for shape change and rapid Ca2+ influx and the other a Gi protein-coupled receptor responsible for Ca2+ mobilization from internal stores, inhibition of adenylyl cyclase and platelet aggregation.

Adenosine Diphosphate↗