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Biomedical subjects

E Rocha

Publications and source records attributed to E Rocha.

At least 163 records · Page 9Linked to original sources
PubMed1986

Effects of 2-indolecarbohydrazides on thromboxane synthetase activity and on in vitro and ex vivo blood platelet aggregation. New selective inhibitors.

Platelet antiaggregatory action of 42 synthetic 2-indolecarbohydrazides was studied observing their actions on arachidonic acid (AA) and adenosine-5-diphosphate (ADP) induced platelet aggregation. Radioimmunoassay studies, following AA induced aggregation, measuring thromboxane B2 (TXB2) and prostaglandin E2 (PGE2) were carried out on those compounds whose previous activities included inhibition of AA induced platelet aggregation and inhibition of the second wave of aggregation using ADP as the aggregating agent. Those compounds which demonstrated inhibition of TXB2 with increased PGE2 were subsequently tested with PGH2 as the aggregating agent. Results of this work demonstrate that 3 of the 42 compounds have specific inhibitory activity for thromboxane synthetase. The most active compounds were 1-methyl-5-hydroxyindole derivatives.

Arachidonic Acid↗
PubMed1985

Postoperative changes in the plasmatic levels of tissue-type plasminogen activator and its fast-acting inhibitor--relationship to deep vein thrombosis and influence of prophylaxis.

Fibrinogen, euglobulin lysis time (ELT), tissue-type plasminogen activator (t-PA) antigen, plasminogen activator inhibitor activity (PA-inhibitor) and alpha 2-antiplasmin (alpha 2-AP) were measured pre- and postoperatively in 60 patients undergoing total hip replacement. Reduced fibrinolytic activity as assessed by the prolongation of euglobulin lysis time, decrease of t-PA and increase of PA-inhibitor and alpha 2-AP could be demonstrated. These changes did not correlate with the postoperative deep vein thrombosis (DVT) diagnosed with the 125I-fibrinogen test. However, preoperative PA-inhibitor activity was significantly higher in patients with postoperative DVT (p less than 0.01). The prophylactic treatment with aspirin (20 patients) and with heparin plus dihydroergotamine (20 patients) induced significant changes in some of those parameters. This study shows that the decrease of t-PA and the increase of PA-inhibitor may contribute to the reduced postoperative fibrinolytic activity after total hip replacement. PA-inhibitor level might be a useful marker in evaluating the risk of developing DVT in patients undergoing total hip replacement.

Aspirin↗
PubMed1985

Anomalous nuclease digestion of Holothuria sperm chromatin containing histone H1 variants.

We have investigated the micrococcal nuclease digestion of chromatin from the spermatozoa of the sea cucumber Holothuria tubulosa. This chromatin contains minor protein variants related to histone H1 with a high proportion of basic amino acids. One of these variants, protein phi 0, represents about 4% of the total histones. It is 78 amino acids long and its amino acid composition and sequence are related to the very basic C-terminal region of histone H1. The presence of these proteins induces an unusual digestion pattern. Oligonucleosomal particles which are soluble at 150 mM NaCl are depleted of protein phi 0 and they are also defective in histone H1. A low percentage of the insoluble material can be solubilized at lower NaCl concentrations (50 mM). These oligonucleosomal particles show a very peculiar protein content, since at early digestion times, they contain histone H1 and protein phi 0 exclusively. We conclude that these particles arise from a cooperative displacement of core histones by protein phi 0 and histone H1. These results show that minor changes in histone H1 complement can result in the formation of artifactual particles upon microccocal nuclease digestion. These observations may be of interest in other systems which contain H1 variants.

Animals↗
PubMed1985

Inherited haemorrhagic disease with abnormal prothrombin consumption.

The propositus is a 4-year-old boy who presented with a history of excessive bleeding after surgical procedures as well as haematomas and epistaxis. The defect in haemostasis consisted in an anomaly of the prothrombin consumption tests as the only abnormality while all the other conventional coagulation and fibrinolysis tests as well as platelet function tests were normal. The father of the propositus had no previous history of excessive bleeding but was found to have an abnormal prothrombin consumption index. The reaction to prothrombin conversion, normal at onset, slowed down to less than normal and did not reach completion until 24 h. The in vivo studies suggest that the effect does not act on the interaction between platelet phospholipid and plasma. The factor II dosage and the electrophoretic mobility of prothrombin of the plasma were normal; nevertheless when studying the purified prothrombin by means of crossed immunoelectrofocusing there appeared an anomaly of pI. This result suggests the possible existence of an abnormal prothrombin molecule responsible for a slow prothrombin conversion.

Blood Coagulation Disorders↗
PubMed1985

Changes in coagulation and fibrinolysis after total hip replacement and their relations with deep vein thrombosis.

Postoperative changes related to coagulation and fibrinolysis and their correlation with the incidence of deep venous thrombosis (DVT) were studied in 30 patients undergoing total hip replacement. Pre- and postoperative measurements of fibrinogen, factor Xa, VIII:C, VIIIR:Ag and its electrophoretic mobility, antifactor Xa activity, antithrombin III (AT III) and its electrophoretic mobility in plasma and serum, fibrin monomers, euglobulin lysis time, fibrinogen degradation products (FDP), alpha 2-antiplasmin and plasmin-antiplasmin complexes were determined. DVT was detected by 125I-fibrinogen leg scanning in 11 patients. There was a significant and progressive increase in fibrinogen, VIII:C, VIIIR:Ag, fibrin monomers, FDP and alpha 2-anti-plasmin levels after operation and likewise a prolongation of euglobulin lysis time. There were changes in electrophoretic mobility of AT III in plasma and serum in 12 patients. The presence of plasmin-antiplasmin complexes was demonstrated in 9 patients. No correlation between the changes in coagulation and fibrinolysis and the incidence of postoperative DVT was found. We conclude that important changes occur in several parameters of coagulation and fibrinolysis after total hip replacement. Such changes are not related to the development of postoperative DVT.

Antithrombin III↗
PubMed1985

Deep vein thrombosis and related platelet changes after total hip replacement.

Postoperative changes related to platelets and their correlation with the incidence of deep venous thrombosis (DVT) were studied in 30 patients undergoing total hip replacement. Levels of platelet count, platelet-crit, mean platelet volume, spontaneous platelet aggregation, platelet factor 4 (PF4) and beta-thromboglobulin (beta-TG) were measured before operation and on the 1st, 3rd and 7th postoperative days. DVT was detected by 125I-fibrinogen leg scanning in 11 of the patients. After the operation there was a significant and progressive increase (p less than 0.01) in PF4 and beta-TG, and the presence of circulating platelet aggregates was demonstrated. Platelet count levels and platelet-crit were decreased on the 1st and 3rd postoperative days followed by recovery on the 7th day. The changes observed following total hip replacement were not related to the development of postoperative DVT.

Blood Platelets↗
PubMed1984

Efficient method for visualization and isolation of proteins resolved in polyacrylamide gels.

Polyacrylamide gel electrophoresis is a popular method used to purify proteins for reconstitution experiments, amino acid composition and sequence determinations. In this report we describe methods that will be of general use in the isolation and characterization of proteins and the benefits of substituting boric acid for glycine in the electrophoresis tray buffers. We also describe how proteins resolved in a variety of gel systems (including those containing sodium dodecyl sulfate) may be rapidly visualized with 8-anilino-1-naphthalene sulfonic acid and efficiently transferred to a second gel for two-dimensional gel analysis, or isolated by electroelution for subsequent characterization.

Anilino Naphthalenesulfonates↗
PubMed1984

Differential salt fractionation of active and inactive genomic domains in chicken erythrocyte.

We have utilized the Sanders salt fractionation technique (Sanders, M. M. (1978) J. Cell Biol. 79, 97-109) to analyze the products of micrococcal nuclease digestion of adult chicken erythrocyte nuclei. By dot-blot hybridization with specific gene probes, it is found that nucleosomes from the globin gene domain, including a region extending to about 10 kilobase pairs 5' to the beta p gene are selectively enriched in the fractions eluted at low salt. In contrast, a single copy sequence located at about 10 kilobase pairs 5' to the beta p gene was concentrated in the less salt-soluble fractions. The vitellogenin and ovalbumin genes, which are never expressed in erythroid tissues, are also concentrated in the less salt-soluble fractions. Some more generally expressed genes (histone H4, thymidine kinase) appear to be more uniformly distributed. The low salt fractions are depleted in H1/H5, enriched in high mobility group 14 and 17, and contain somewhat more highly acetylated histones.

Animals↗
PubMed1983

Splenic hamartoma, vascular type, with endothelial proliferation.

Vascular tumors of the spleen have shown a wide spectrum of histologic features. We present the case history of a 65-year old woman with weight loss, anemia and thrombocytopenia associated with a vascular tumor of the spleen. Grossly, the tumor appeared like the red pulp of the spleen. On microscopic examination, however, a papillary proliferation of the endothelial cells which caused narrowing of the lumina of newly-formed vessels was seen. The endothelial cells further showed multiple cytoplasmic projections with few junctions under electron microscopy. In spite of the morphology the tumor proved to be benign. This appears to be the first ultrastructural study of such type of vascular tumor.

Aged↗
PubMed1982

[Cutaneous infiltration in multiple myeloma].

A 44 year old woman with multiple myeloma and cutaneous involvement is presented. She had a painless tumor over the malar region. Microscopic study showed a cutaneous infiltration of plasma cells. Survival from diagnosis lasted 5 months. Over this period, multiple and progressive cutaneous nodules appeared, having the same structural characteristics.

Adult↗