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Biomedical subjects

L Vargas

Publications and source records attributed to L Vargas.

At least 55 records · Page 3Linked to original sources
PubMed1986

Alcohol use and interpersonal violence: alcohol detected in homicide victims.

To characterize the relationship between alcohol use and homicide victimization, we used data from the Los Angeles City Police Department and the Los Angeles Medical Examiner's Office to study 4,950 victims of criminal homicides in Los Angeles in the period 1970-79. Alcohol was detected in the blood of 1,883 (46 per cent) of the 4,092 victims who were tested. In 30 per cent of those tested, the blood alcohol level was greater than or equal to 100 mg/100 ml, the level of legal intoxication in most states. Blood alcohol was present most commonly in victims who were male, young, and Latino, categories where rates have been increasing at an alarming pace. Alcohol was also detected most commonly in victims killed during weekends, when homicides occurred in bars or restaurants, when homicides resulted from physical fights or verbal arguments, when victims were friends or acquaintances of offenders, and when homicides resulted from stabbings. The evidence for alcohol use by homicide victims focuses attention on the need for controlled epidemiologic studies of the role played by alcohol as a risk factor in homicide and on the importance of considering situational variables in developing approaches to homicide prevention.

Adolescent↗
PubMed1985

Control of directionality in lambda site specific recombination.

The simple relation between the substrates and products of site-specific recombination raises questions about the control of directionality often observed in this class of DNA transactions. For bacteriophage lambda, viral integration and excision proceed by discrete pathways, and DNA substrates with the intrinsic property of recombining in only one direction can be constructed. These pathways display an asymmetric reliance on a complex array of protein binding sites, and they respond differently to changes in the concentrations of the relevant proteins. The Escherichia coli protein integration host factor (IHF) differentially affects integrative and excisive recombination, thereby influencing directionality. A four- to eightfold increase in intracellular IHF coincides with the transition from exponential to stationary phase; this provides a mechanism for growth phase-dependent regulation of recombination that makes the cellular physiology an intrinsic part of the recombination reaction.

Bacterial Proteins↗
PubMed1984

Effect of age on poly- and monoglutamyl folacin absorption in human subjects.

Intestinal folacin absorption and mucosal conjugase activities were assessed in healthy male elderly (65-83 years) and young (20-29 years) human subjects. Luminal disappearance as measured simultaneously from the perfused jejunum of 3 mumol of both [3H]pteroylmonoglutamate [( 3H]PG-1) and pteroyl-[14C]glutamyl-hexaglutamate [( 14C]PG-7) as well as the urinary recovery of each isotope and mucosal conjugase activities were compared. Luminal disappearance of either [3H]PG-1 or [14C]PG-7 was not different for the two age groups (P greater than 0.05). The average (mean +/- SD) disappearance of [3H]PG-1 was 63 +/- 12% in the elderly and 67 +/- 6% in the young groups. In contrast, the disappearance of [14C]PG-7 averaged 51 +/- 6% in the elderly and 48 +/- 3% in the young group. Urinary recovery (percent in 48 hours) was not different for either isotope when the two age groups were compared (P greater than 0.05). The urinary recovery of 3H averaged 60 +/- 21% in the elderly and 59 +/- 13% in the young in contrast to 35 +/- 22% and 35 +/- 7% for 14C recovery in the elderly and young groups, respectively. Folacin conjugase activities measured at pH 6.5 and at pH 4.5 were not different between the groups (P greater than 0.05). The findings indicate that intestinal absorption of folacin and activity of folacin conjugases are not affected by the aging process.

Adult↗
PubMed1981

[Practical introduction of the medical student to biomedical research].

This paper reports on a course being given in the Institute of Biological Sciences of the Catholic University of Chile in which third-year medical students are introduced to biomedical research participating in it as assistants. The primary aim of the course is instruction in the scientific method on a tutorial basis. The course is elective; it is directed and coordinated by a professor, and conducted by tutoring professors engaged in research. The student chooses a research project from a list presented by the tutoring professors through the professor in charge. His performance is evaluated on the basis of his participation in the work itself and discussions of it, his presentation to the final session of the course, and his manuscript. In the last ten years, 47 per cent of the third-year medical students have taken and passed this course. Performance has been on the rise as shown by the fact that the results of ten of the research projects conducted in the course have been published in the last six years. A student who wishes to continue in a research project may compete for the position of student assistant offered by the School of Medicine, in which post he is enabled to complete his scientific training and the project he had started in.

Chile↗
PubMed1980

Entomologic considerations in the study of onchocerciasis transmission.

The entomological resources utilized for a better understanding of Onchocerca volvulus transmission are discussed in this paper. Vector density, anthropohilia, gonotrophic cycyle, parous condition longevity and probability of survival in days after the infectious meal are assessed here in order to integrate an overall picture. The concept of vectorial capacity is developed stressing the quantitative aspects. Parasitism of the black-flies by filariae that are doubtfully identified as O. volvulus is also mentioned here.

Animals↗