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Biomedical subjects

E Rocha

Publications and source records attributed to E Rocha.

At least 199 records · Page 11Linked to original sources
PubMed1977

Interaction of uricine with uric acid and its effect on uric acid precipitation.

Uricine is a yellow-red pigment isolated from uric acid stones where it is always found. It binds to the uric acid, as shown by gel chromatography, at constant uric acid elution. It also increases the capacity of the uric acid to form larger aggregates and therefore the capacity of the uric acid to precipitate is enhanced. The uric acid-uricine aggregates may be separated by high speed sucrose centrifugation gradients.

Binding Sites↗
PubMed1977

Urinary excretion of uricine.

The excretion of uricine or yellowish-red pigment from uric acid stones and its binding by uric acid seems to affect the precipitation of uric acid. Uricine was determined by ion exchange chromatography followed by measurement of the alkaline fluorescence emission. The uricine urinary excretion and the uricine-uric acid potential binding were determined in 11 control subjects, 20 recurrent uric acid stone formers, seven calcium stone formers with hyperuricuria, and five gouty patients without urinary stone formation. Uricine excretion was increased in 11 uric acid stone formers, whereas it was normal in the rest of the patients. Uricine-uric acid potential binding was increased in many uric acid stone formers, despite the absence of uric acid urinary hyperexcretion, whereas it was normal in most of the calcium stone formers and was moderately increased in the gouty patients.

Adult↗
PubMed1976

Isolation and characterization of uricine from uric acid stones.

Uricine was found to be present in all uric acid stones tested, although another physiochemically related pigment was occasionally present. Uricine is of low molecular weight (28.2) and a preliminary analysis of its structure suggests that it is formed by two pyrrolic rings. It is a yellow pigment whose color is pH-dependent, shifting from reddish-yellow to green at pH 1.0. It is water soluble, but its solubility increases in alkaline solutions. Preliminary evidence suggests that uricine is related metabolically to bilirubin-like compounds.

Chemical Phenomena↗
PubMedDate not supplied

Role of sialic acid in acquired dysfibrinogenemia associated with liver cirrhosis.

The possible existence of acquired dysfibrinogenemia was investigated in blood samples from 30 patients with liver cirrhosis, 15 newborns and 30 healthy control subjects. Alterations of thrombin time were found in newborns and in 14 cirrhotic patients; glucide fraction levels were measured in these subjects and an increase in sialic acid content was observed. Its functional role was studied by comparing thrombin time and electrophoretic mobility of purified and desialylated forms of fibrinogen. We observed a thrombin time normalization, which was initially prolonged upon the removal of the sialic acid. The anodic electrophoretic mobility underwent changes due to the removal of sialic acid.

Adult↗
PubMedDate not supplied

Fibrinogen Logroño. A new case of congenital dysfibrinogenemia.

An abnormal fibrinogen was discovered in a 9-year-old male subject without history of hemorrhagic diathesis. Coagulation time, prothrombin time and Reptilase time were prolonged. The thrombin time was corrected using increasing concentrations of normal plasma and bovine thrombin; there was a partial correction at pH 6.5 and ionic strength 0.05. A study of the family showed that the mother and a brother of the propositus presented the same abnormalities. Analysis of the purified fibrinogen showed normal fibrinopeptide release and normal levels of sialic acid and hexosamines. However, coagulation index, polymerization of fibrin monomers, isoelectric point and sedimentation coefficient were abnormal. In view of the abnormalities described and by comparison with the data reported in the literature, we believe that this should be considered a new variant of the fibrinogen molecule and we have designated it 'fibrinogen Logroño'.

Blood Coagulation Disorders↗