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Biomedical subjects

J Velasco

Publications and source records attributed to J Velasco.

At least 91 records · Page 5Linked to original sources
PubMed1984

Comparative characterization of Venezuelan Trypanosoma cruzi stocks by electron microscopy, isoelectrofocusing and lectin typing.

The intraspecific variation among culture forms of 14 Venezuelan Trypanosoma cruzi stocks were examined by kDNA configuration, isoenzymes, and agglutination behaviour of lectins. The results have shown that in all of the stocks the central band of kDNA is present, showing that the stocks are parasites of the subgenus Schizotrypanum. By isoenzymes and lectin typing it has been found that the stocks belong to the isoenzyme group I and the lectin-type PNA which were already described for other Venezuelan stocks. The homogeneous results of intraspecific characterization contrast to those found in other countries in South America south of the Amazon basin and seem to be a further evidence that in countries north of the Amazon basin mainly on T. cruzi-type exists.

Agglutination Tests↗
PubMed1982

Hepatobiliary scanning in cholecystitis.

To validate the use of 99mTc-PIPIDA in the diagnosis of biliary tract disease, 117 patients with clinical symptoms of acute cholecystitis were prospectively scanned as an initial screening test. The accuracy of the test was evaluated on the basis of surgical pathology in 59 patients. Three groups were defined: cystic duct obstruction, common duct obstruction, and normal scan. The diagnostic accuracy of the test for acute cholecystitis was 97%. Complete common duct obstruction was confirmed at surgery in 12 patients (100%). A normal scan helped to rule out acute cholecystitis. Jaundice did not influence the reliability of the method. Hepatobiliary scanning is an accurate, safe, and rapid diagnostic test for acute cholecystitis.

Acute Disease↗
PubMed1975

Fluorometric measurement of aflatoxin adsorbed on florisil in minicolumns.

Filter fluorometers have been adapted to measure the fluorescence intensity of aflatoxin absorbed on a Florisil layer in minicolumns. The relationship between concentration and intensity is near linear in the aflatoxin range from 10 to 100 ng. Although individual aflatoxin fractions cannot be resolved, since the measure is one of total intensity, fluorometric measurements advance the minicolumn screening procedure to a semiquantitative level. The detection of 1 ng aflatoxin B1 is well within the limits of a filter fluorometer with a photomultiplier detector. A precision, expressed as per cent coefficient of variation, ranging from 1.2 to 4.2%, was obtained for standard B1 columns.

Adsorption↗
PubMedDate not supplied

Prospective study of the enzymatic activities in urine of N-acetyl-beta-D-glucosaminidase, alpha-D-mannosidase, alpha- and beta-D-glucosidases, alpha-L- and beta-D-fucosidases, and beta-D-galactosidase in type I diabetes mellitus with early nephropathy.

Different surveys have been carried out on the plasma activities of different glycosidases in patients with insulin-dependent diabetes mellitus, but research on urinary glycosidases in this disease is scanty and incomplete. To elucidate the behavior of these lysosomal enzymes in the metabolic alterations occurring in the glomerular basal membrane during the initial stages of diabetic nephropathy, we conducted a prospective study to examine the urinary activities of N-acetyl-beta-D-glucosaminidase (NAG), alpha-D-mannosidase, alpha- and beta-D-glucosidase, alpha-L- and beta-D-fucosidase, and beta-D-galactosidase in patients with type I insulin-dependent diabetes mellitus, surveyed over 18 months, whose early diabetic nephropathy was detected by the presence of microalbuminuria. The simultaneous determination of beta 2-microglobulin in urine confirmed the glomerular origin of the albuminuria. No statistically significant correlation was found between the levels of albuminuria and the activities of any of the glycosidases analyzed. In the diabetic patients, a significant decrease was observed in the activities of all the enzymes (p < 0.05), except NAG and alpha-D-mannosidase, although the decrease in the latter was very close to statistical significance (p = 0.028, unilateral; p = 0.057 bilateral). Similarly, in the patients, there was a significant negative correlation (p < 0.05) with the serum levels of fructosamine, except with beta-D-galactosidase, which showed a positive correlation (p < 0.05) with fructosamine and blood HbA1c.(ABSTRACT TRUNCATED AT 250 WORDS)

Acetylglucosaminidase↗