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Biomedical subjects

R Guerra

Publications and source records attributed to R Guerra.

113 records · Page 7Linked to original sources

[Study on 190 strains of "staphylococcus aureus" isolated in a department of ophthalmology (author's transl)].

Biochemical features and sensitivity to chemotherapeutic agents of 190 strains of Staphylococcus isolated from pharinx and conjunctiva of ophtalmological patients and staff were studied. Each strain was investigated for: pigment, coagulase, hemolysis (alpha-toxin), phosphatase and penicillinase production and mannite fermentation. Twentyfour chemotherapeutic angents were used for sensitivity tests. The Authors emphasize that a positive coagulase test is the best laboratory evidence for pathogenicity of a given strain of Staphylococcus, and that the site of isolation of the examined strains is not related with their biochemical features and sensitivity to chemotherapeutic agents.

Anti-Bacterial Agents↗

Acute effects of soft drink intake on calcium and phosphate metabolism in immature and adult rats.

OBJECTIVE: To test the acute effects of the intake of a phosphoric acid containing soft drink on acid-base balance and on calcium and phosphate metabolism. MATERIAL AND METHODS: We studied 14 young adult male Sprague-Dawley rats aged 90 days, and 14 immature animals aged 30 days. Half of the animals in each group were randomly assigned to receive either tap water (controls), or Coca-Cola ad libitum for seven days. After this period, the rats were individually placed in metabolic cages to collect 24 hours urine, and they were exsanguinated by aortic puncture. Immediately, pH and ionized calcium were measured in whole blood. Creatinine, phosphate and total calcium were determined in the urine and plasma. Plasma levels of PTH, 1 alpha, 25 (OH)2 D3 and 25 OH D3 were measured by IRMA and RIA commercial kits. RESULTS: The animals receiving the soft drink, both adults and immature, developed significant hypercalciuria and hyperphosphaturia. In immature animals, the plasma pH dropped from 7.45 +/- 0.04 to 7.33 +/- 0.02 (p < 0.05) but did not change in adult animals. Ionized calcium dropped significantly from 1.06 +/- 0.04 to 0.80 +/- 0.06 meq/L (p < 0.05) in immature animals but not in the adult animals. Only immature rats developed significant reduction of 1 alpha, 25 (OH)2 D3 and 25 OH D3, whereas only the adult rats developed significant hyperparathyroidism. Immature animals showed more severe derangement of calcium and phosphate metabolism related to soft drink intake.

Acid-Base Equilibrium↗