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Biomedical subjects

J Zamora

Publications and source records attributed to J Zamora.

66 records · Page 4Linked to original sources
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Hemolysins and verotoxin (VT) in enteric Escherichia coli isolated from pigs.

One hundred and three E. coli strains isolated from the intestinal contents of pigs were examined for hemolysis and verotoxin production on Vero monolayer cells. Hemolysins were produced by 18 (17.5%) strains;--hemolysin was produced by 6 strains of which 4 belonged to serotype O149:K91, K88ac;--hemolysin was produced by 8 strains which could no be serotyped; 1 strain produced-hemolysin and possessed fimbrial antigens K88; the remaining 3 strains were enterohemolytic and VT producers. Among the 85 non-hemolytic strains, 11 showed some antigenic properties. Only 3 could be serotyped (O64:K 'V142'; O157:K 'V17' and O149:K91); 4 had fimbrial antigens K88 and 1 strain was K99, and 3 possessed capsular antigen (K89). According to these results it is possible to conclude that both hemolytic and non-hemolytic E. coli strains could be pathogenic.

Age Factors↗
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A serological survey of leptospirosis in sheep in Chile.

In order to investigate exposure to Leptospira spp. in sheep in the Xth Region in the south of Chile, 629 ovine serum samples were collected from 11 convenience selected sheep farms, using within farm random sampling. The sera collected were examined for antibodies to the following serovars; icterohaemorrhagiae, autumnalis, hardjo, pomona, ballum, and canicola, using the Microscopic Agglutination Test. Ten out of eleven flocks had sheep which were seropositive for at least one Leptospira spp. Positive tests, the majority at low titres, were obtained from 36/629 (5.7%) of all the serum samples tested. The most frequently detected serovars were, in descending order: icterohaemorrhagiae, autumnalis and hardjo. The greatest proportion of positive samples came from sheep which were over 30 months old.

Age Factors↗
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[Fasting and postprandial lipids and lipoproteins during the chronic administration of antihypertensive drugs].

To evaluate the effect of various antihypertensive drugs on fasting and postprandial lipids and lipoproteins, we studied 39 normolipidemic hypertensive patients, 28 men and 11 women aged 52.3 +/- 9.0 and 58.5 +/- 7 years, respectively. After four weeks of placebo administration, lipids and lipoproteins were measured in the fasting state and every three hours for a period of nine hours after intake of a standardized fat mixed load (65 g/m2). Following this test, the patients were randomly assigned to one of four treatment groups: group I metoprolol (n = 10), 100 mg/day; group II nicardipine (n = 9), 90 mg/day; group III captopril (n = 11), 75 mg/day. At the end of week four of treatment the fasting and postprandial lipid measurements were repeated. Blood pressure mean values were significantly (p < 0.05) reduced in the four treatment groups. We found no statistically significant lipids or lipoproteins changes neither in the fasting nor in the postprandial state, but a trend toward lower concentrations in the postprandial lipemia after treatment was observed in three groups (metoprolol, nicardipine and captopril), whereas no change was observed in the chlorthalidone group. These data confirm that fasting lipids and lipoproteins in normolipidemic hypertensive patients are not unfavorably changed by low doses of the drugs studied. In addition, we inform that postprandial lipemia is not affected by these four drugs in the doses used.

Adult↗
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[Comparison of 4 microscopy techniques for the diagnosis of leptospirosis in wild rodents in a rural area of Valdivia, Chile].

Kidneys of six different species of 93 wild rodents captured in the rural area of Valdivia (Chile) were simultaneously examined for leptospira infection by means of Levaditi silver stain, dark ground microscopy in wet smears, and immunofluorescence and immunoperoxidase techniques using pooled antiserum against hardjo and pomona serovars. Leptospira was shown to be present in 40 (43.0%) rodents. They were detected in five of the six species: Akodon olivaceus, Akodon longipilis, Rattus rattus, Oryzomis longicaudatus and Mus musculus. Levaditi's technique detected the highest number of positive samples (67.5%) and the dark field microscopy the lowest (32.5%). The detection of leptospira in the kidneys of these wild rodents suggests that their urine may play an important role in the dissemination of leptospirosis in this area of Valdivia.

Animals↗