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Biomedical subjects

E Benavides

Publications and source records attributed to E Benavides.

12 recordsLinked to original sources
PubMed2000

A minimalist approach to gene mapping: locating the gene for acheiropodia, by homozygosity analysis.

Acheiropodia is an autosomal recessive disease that results in hemimelia (lack of formation of the distal extremities). We performed a complete genome screen of seven members of an extended pedigree that included three siblings with acheiropodia. Homozygosity mapping was used to identify regions most likely to harbor the gene for acheiropodia in this pedigree. In these two key regions (14p and 7q), further genotyping of one additional affected member of this pedigree plus seven additional unaffected siblings provided evidence, through linkage analysis, that the 7q36 region contains the acheiropodia gene. In this region, a maximum two-point LOD score of 3.81 (4.2 with multipoint analysis) was achieved, and a homozygous haplotype spanning a region of 11.7 cM was seen in all affected in this pedigree. Finally, genotypic analysis of two additional cases of acheiropodia with no known relation to the other samples revealed homozygous sharing of a portion of the same haplotype on 7q36, which reduces the chromosomal location of the acheiropodia gene to an 8.6-cM region. Localization of this gene, at the screening level, by use of data from only three affected subjects, provides an example of how certain genes may be mapped by use of a minimal number of affected cases.

Brazil↗
PubMed1998

Peripheral axons of Wlds mice, which regenerate after a delay of several weeks, do so readily when transcription is inhibited in the distal stump.

We have raised the hypothesis that differentiated Schwann cells repress regrowth of axons but become permissive upon dedifferentiation. WId(S) mouse is a strain in which severed peripheral nerves do not degenerate for several weeks, and axonal regeneration does not occur either [5,11]. In this strain, we studied the role of resident cells upon axonal regeneration by inhibiting transcription. Regeneration was assessed with the pinch test, electron microscopy and Dil (a fluorescent lipid soluble dye). After a crush, WId(S) axons did not regenerate but they did so when the crush was made through a nerve segment treated with actinomycin D (ActD), an inhibitor of transcription. In contrast, when the crush was made distal to the treated segment no regeneration ensued. Our results support the notion that normal resident cells of peripheral nerves repress axonal growth.

Animals↗
PubMed1998

[Ulcerative colitis and pregnancy].

BACKGROUND: The evolution of ulcerative colitis in pregnancy is far from clear. While some authors state that the disease aggravates during this period, others do not share this opinion. AIM: To assess the evolution of ulcerative colitis in pregnancy. PATIENTS AND METHODS: A paired case-control design was used in which 15 women, with diagnosed ulcerative colitis at the moment of becoming pregnant, were followed for 12 months and the activity of the disease was compared with that of the 12 months preceding the pregnancy. The activity of the disease in the period preceding the pregnancy was gathered retrospectively from the patient's charts. RESULTS: The mean age of the first ulcerative colitis crisis was 24 years. It was moderate in 49% and severe in 35% of women. During pregnancy 55% of women did not have a crisis, compared with 26.7% during the period preceding pregnancy (relative risk of not having a crisis during pregnancy of 1.7). During both periods, seven women had digestive complications, whereas extra digestive complications were not observed in 60% of patients during pregnancy and 11.8% of patients during the preceding period. Perinatal results were similar to those of the general population. CONCLUSIONS: In our group of patients the evolution of ulcerative colitis was better during pregnancy, reflected by a lower number of crisis.

Colitis, Ulcerative↗
PubMed1997

[Mortality due to traffic accidents in Chile, 1994: an epidemiological approach].

BACKGROUND: Traffic accidents are one of the most important public health problems in the world and produce social, work and human resources losses. AIM: To perform an epidemiological description of traffic accidents occurred in Chile during 1994. MATERIAL AND METHODS: Data were obtained from death certificates in which the cause of death was a traffic accident. All death certificates obtained by the National Institute of Statistics during 1994 were used. Social, demographic and seasonal variables were recorded. RESULTS: During 1994, there were 1679 deaths due to traffic accidents (81% male), with a rate of 19.6 per 100,000 inhabitants. Gender specific risks were 19.62 and 4.48 for men and women, respectively. Mean age at the moment of death was 39 years old. Fifty three percent of deceased people were single, 42% married and 5% widowers. Ten percent had no formal education, 48% had basic education, 23% college education and 6.5% university education. Seventy seven percent of fatalities occurred in urban areas. The risk of death by traffic accidents was 7.02 per 100,000 inhabitants in the metropolitan region. CONCLUSIONS: The information obtained in the present study may help to generate preventive strategies to control deaths caused by traffic accidents.

Accidents, Traffic↗
PubMed1996

Evidence for linkage of regions on chromosomes 6 and 11 to plasma glucose concentrations in Mexican Americans.

The genetic factors involved in type II diabetes are still unknown. To address this problem, we are creating a 10 to 15 cM genetic map on 444 individuals from 32 Mexican American families ascertained on a type II diabetic proband. Using highly polymorphic microsatellite markers and a multipoint variance components method, we found evidence for linkage of plasma glucose concentration 2 hr after oral glucose administration to two regions on chromosome 11: beta-hemoglobin (HBB) and markers D11S899/D11S1324 near the sulfonylurea receptor (SUR) gene. Iod scores at these two loci were 2.77 and 3.37, respectively. The SUR gene region accounted for 44.7% of the phenotypic variance. Evidence for linkage to fasting glucose concentration was also observed for two loci on chromosome 6, one of which is identical to a proposed susceptibility locus for type I diabetes (D6S290). When diabetics were excluded from the analyses, all Iod scores became zero, suggesting that the observed linkages were with the trait diabetes rather than with normal variation in glucose levels. Results were similar whether all diabetics were included in the analyses or only those who were not under treatment with oral antidiabetic agents or insulin.

Blood Glucose↗
PubMed1986

A survey of homeless adults in urban emergency shelters.

Following a review of several studies of homeless populations, the authors describe a survey of 68 homeless adults in eight urban emergency shelters in Hennepin County, Minnesota. The results indicated impressive rates of mental illness, alcoholism, minor criminality, and chronic medical and dental problems. More significant, the authors believe, both for the homeless and for public policy planners, is that a majority of the interviewees were disconnected from supportive social networks and were underutilizing medical and welfare programs for which they were eligible. Almost 40 percent of those with chronic health problems were receiving no medical care, and only 6 percent were receiving mental health services, although more than 50 percent needed such care. The authors compare the findings with those of studies discussed in the literature review.

Adult↗
PubMed1984

Boophilus microplus tick burdens on grazing cattle in Colombia.

This study was conducted at Carimagua Research Centre in a well-drained savanna area in the eastern plains of Colombia. The objectives were to note the effect of ecological factors on tick burdens, principally the effect of the environment given by four grasses on the seasonal variations of tick populations. Adult female tick counts were carried out on heifers grazing four pastures and tick larvae on the grass detected by cloth dragging. Tick counts were significantly higher on animals grazing Brachiaria decumbens than those grazing Andropogon gayanus, Melinis minutiflora or native pastures. Tick larvae counts on the grass showed a similar tendency. Introduced grasses and intensification of production will require greater care to control tick infestations since increases in stocking rate and ground coverage could augment tick populations.

Animals↗