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Biomedical subjects

E Márquez

Publications and source records attributed to E Márquez.

17 recordsLinked to original sources

Clonal population structure of Colombian sylvatic Trypanosoma cruzi.

Isoenzyme variability and evidence of genetic exchange were evaluated in 75 wild stocks of Trypanosoma cruzi obtained from different hosts from 5 geographical regions within the endemic area in Colombia. Cluster analysis of genetic variability was attempted. Thirty-three multilocus enzyme genotypes (clonets) were identified from 75 stocks, 27 of which clustered with zymodeme Z1 and 6 with zymodeme Z3. Two stocks isolated from human infections showed the potential risk to rural communities in Colombia. The stocks exhibited departures from Hardy-Weinberg expectations, including both fixed heterozygote and fixed homozygote demes, where both segregation and recombination were absent. To inspect for population subdivision that might falsely imply clonality in these stocks, Wright's F statistics were calculated. Theta values (Fst) were significantly different from 0 when 33 clonets, 27 Z1-like clonets, and 5 geographical subpopulations were compared; thus, a significant amount of divergence has occurred between and within them. In addition, linkage disequilibrium was detected for most possible pairwise comparisons of loci. In conclusion, the above results all support a scenario of long-term clonal evolution in Colombian sylvatic T. cruzi populations.

Animals

[Cholesterol content in longissimus muscle beef from slaughter cattle in Venezuela].

An observational study was conducted with 149 cattle, raised under tropical conditions of Venezuela (mostly grassfed), to study the relationships of sex class (62 bulls, 67 steers, 20 heifers), age by dentition (2.5; 3.0; 3.5 and 4.0 yr), physiological maturity (A or B), cattle type (17 Dairy or 132 Zebu type crossbreds), Venezuelan carcass grade (Optima, Excelente, Selecta or Superior), marbling level (four levels from "None" to "Small quantity"), carcass fat cover (four level: "Even", "Uneven", "patch-like" and "Devoid") and subcutaneous fat thickness (SFT) over the ribeye (1 = 0.1-0.2 cm; 2 = 0.3-0.4 cm; 3 = 0.5-0.9 cm and 4 = > 1.0 cm) on cholesterol content (mg/ 100 g wet weight) of longissimus muscle. Cholesterol content, as determined colormetrically, did not vary in response to the differences in sex class, age, maturity level, carcass grade, marbling level or SFT represented in the present survey. However, cattle type affected (P = 0.08) cholesterol content. Least square means analysis showed that dairy type contained 12.2 mg more of cholesterol/100 g of muscle than Zebu type. The overall mean (+/- SD) muscle cholesterol for the kind of cattle sampled herein (66.6 +/- 16 mg/100 g) was not considered to be different from those of cattle fed in other latitudes.

Animals

[Evaluation of the incidence of nephrotoxicity associated with the use of aminoglycosides in patients with extrahepatic biliary obstruction].

In the present publication we discuss nephrotoxicity (NT) incidence by reviewing all the clinical histories of one year (May 1989-May 1990) with diagnosis of obstructive jaundice or cholangitis. Of a total of 90 patients. 53 were treated with aminoglycosides and 37 received other antibiotics. Nephrotoxicity developed in nine patients of the group that received aminoglycosides (17%), versus only three patients (8%) in the other group. Both groups were comparable regarding sex, age and liver and renal basal functions. Analysis of the variables that could be associated with a higher incidence in the nephrotoxicity group that received aminoglycosides showed that there were no differences regarding age, sex, dosage, duration of treatment, plasmatic levels of aminoglycosides and liver and renal basal functions. Only simultaneous administration o furosemide was significantly associated with the development of nephrotoxicity. Results of this study underline the need of a prospective follow-up of patients with biliary obstruction during treatment with aminoglycosides. Meanwhile the evidence available allows us to recommend the monitoring of renal function in this type of patients.

Aged

[NKCELPRO: a program for microcomputer applicable to the study of responses of spontaneous cytotoxicity].

A microcomputer program (NKCELPRO) which expedites the exact quantification of various parameters referring to NK cell activities is described. The program is written in BASIC language and computes the activities of cell-mediated cytotoxicity by collating and reducing radioactive count data obtained from 51Cr releasing assays. The information generated by this program includes statistics such as the average values, fitting by last square regression line with its correlation coefficient, as well as determination of the percent specific lysis and lytic units/10(7) effector cells according to any reference value previously defined by the operator. Special program features allow for a certain flexibility in the experimental protocol design as well as in the graphic expression of the results. Data storage on a disk with filing purposes for subsequent studies is also available.

Computers

[Single photon emission tomography (SPECT) in severe infantile myoclonic epilepsy (EMS)].

Ten children, three boys and seven girls, with an average age of 7.5 years diagnosed as having severe myoclonic epilepsy (SME) underwent single photon emission computerised tomography (SPECT) with HMPAO. All had CT, nuclear MR and various EEG studies, these findings made at the same time as SPECT. CT and nuclear MR produced no relevant data. EEG, although without paroxystic abnormalities in two cases, showed generalised discharge in the remaining eight, predominantly in the right hemisphere in five. SPECT was normal in two cases (of 20 and 30 months) and showed areas of hypoperfusion localised in one hemisphere in five cases, three in the left and two in the right, and in both hemispheres in three cases. Areas of hypoperfusion were located in frontal and/or temporal and/or parietal regions. In two cases there was concordance with the prevalence of EEG paroxystic activity and in two other cases there was discordance. Our findings, with SPECT abnormalities after two years of age, suggest SME could be considered as a multifocal epilepsy brought on by secondary structural irregularities.

Adolescent