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Biomedical subjects

V Jimenez

Publications and source records attributed to V Jimenez.

At least 19 recordsLinked to original sources
PubMed1996

Epidemiological survey of hypodermosis in western Spain.

A serological survey was carried out to establish the prevalence of hypodermosis in Extremadura, a region of western Spain. Direct clinical methods and an enzyme linked immunosorbent assay (ELISA) were used to examine 1668 cattle between February 1992 and March 1993. An overall prevalence of 19.54 per cent was observed by the direct methods, and a prevalence of 42.3 per cent by the ELISA. The sensitivity and specificity of the ELISA for hypodermosis were assessed, and the fluctuation of antibody levels was studied throughout the year and correlated with the age of the host, the intensity of parasitism and the mean larval burden.

Animals↗
PubMed1996

Use of persistent infections with vaccinia virus recombinants to introduce alterations in foreign proteins: an application to HIV-1 env protein.

With the aim of generating a virus-cell system to introduce alterations in proteins of interest--which may be of use in studies of their biological functions--we established a persistent infection on a B-lymphoma cell line (A20.2J) with vaccinia virus (VV) recombinants. As a model, we used a vaccinia virus recombinant expressing the human immunodeficiency virus HIV-1 env gene. In this unique virus-cell system, we found that it is possible to introduce several structural and functional alterations in the env protein with passage numbers. From passage 10-20, two new env products emerged: an uncleaved gp160 and a glycoprotein fragment of 110 kDa. The uncleaved gp160 exhibit interesting properties as an immunogen. This protein forms stable oligomers, is not released from the cells, cannot fuse CD4+ presenting HeLa cells and activates a stronger cellular immune response than the parental cleaved env. In contrast, the 110 kDa product is a poor immunogen, since it lacks the gp41 domain, cannot form oligomers, accumulates intracellularly and cannot fuse CD4+ cells. In the persistently infected cells we have also found alterations in another heterologous protein-beta-galactosidase-a gene inserted in the same locus of VV as the env gene. This alteration resulted in a truncation of the (beta-galactosidase protein from 125 kDa to about 70 kDa. A similar size truncation of env and of beta-galactosidase was observed in many of the isolated VV recombinants.

Animals↗
PubMed1996

Chlorothalonil, a possible cause of erythema dyschromicum perstans (ashy dermatitis).

We studied 39 patients with erythema-dyschromicum-perstans-like dermatitis seen at Changuinola Hospital in Panama. They were compared with 41 controls. The 2 groups were native field workers of the banana plantations exposed to many pesticides. In 34 patients, there was a positive patch test reaction to 2,4,5,6-1,3-tetrachloroisophthalonilnitrile (chlorothalonil, TCPN) 0.001% in acetone. In 39 cases, biopsies showed a lichenoid tissue reaction compatible with a chronic pigmented dermatitis or erythema-dyschromicum-perstans-like dermatitis. Chlorothalonil is possibly the cause of the pigmented dermatitis observed in the 39 banana farm workers studied. Until additional studies are carried out, we consider this a possible rather than definite cause-and-effect relationship.

Adult↗
PubMed1996

Plasma neurotransmitters, blood pressure and heart rate during supine resting, orthostasis and moderate exercise in severely ill patients: a model of failing to cope with stress.

BACKGROUND: Previous clinical research has shown that severely ill (somatic) as well as many psychosomatic patients show raised noradrenaline (NA), adrenaline (AD), cortisol, free serotonin (f5HT) and platelet aggregability. Conversely, they show reduced NA/AD plasma ratio and platelet serotonin (p5HT). They also show adrenal hyperresponsiveness to an oral glucose load. These findings are opposed to those observed in depressed patients who show adrenal gland sympathetic hyporesponsiveness and neural sympathetic hyperactivity. OBJECTIVE: To investigate adrenal gland and neural sympathetic systems as well as the other parameters in nondrepressed severely ill patients through the orthostasis exercise stress test which in normals triggers NA but no AD rise. METHODS: We investigated 35 severely ill patients and their age- and sex-paired controls. Systolic, diastolic pulse pressure (PP), heart rate and neuroendocrine parameters were measured supine (0 min), at orthostasis (1 min) and exercise (5 min). A second test was performed 2 weeks later, after atropine injection. Multivariate analysis of variance, paired t test and Pearson product-moment test were employed. RESULTS: The normal PP orthostasis fall was not observed in patients. At this period, an abnormal AD peak substituted the normal NA peak. The normal p5HT-f5HT orthostasis-exercise peaks were absent in patients. Cortisol and platelet aggregability were raised in patients. CONCLUSIONS: Severely ill (somatic) patients responded to the orthostasis-exercise stress test with adrenal and corticosuprarenal but not neural sympathetic activity. They did not show the normal parasympathetic activity at orthostasis. This adrenal gland sympathetic hyperactivity registered in somatic patients is similar to that observed in mammals which fail to cope with stress and contrary to the profile registered in depressed subjects who show NA but not AD rise.

Adolescent↗
PubMed1996

Tuberculosis.

Dental health care providers must play an active role in preventing the transmission of tuberculosis. The information presented here should allow them to appropriately identify and refer patients who may be infectious, identify oral lesions which may be due to tuberculosis, and develop and implement an infection control plan to prevent transmission in the dental setting.

Dental Care for Chronically Ill↗
PubMed1996

Multizone versus monozone in the treatment of high and moderate myopia with an excimer laser.

BACKGROUND AND OBJECTIVE: Numerous modifications have been proposed to photorefractive keratectomy (PRK) in the treatment of myopia in excess of 6.00 diopters (D). One of the techniques employed in an attempt to achieve better refractive results and to avoid, above all, the appearance of an intense haze, is the technique known as multizone. PATIENTS AND METHODS: We have attempted, in a prospective study, to compare the refractive results and the complications of monozone and multizone techniques for the treatment of moderate and high myopia. We performed 139 monozone PRKs and 30 multizone PRKs with a one-year follow-up. RESULTS: We did not find statistically significant differences between the two groups either in the degree of correction obtained nor in the final visual acuity. A statistically significant difference was found only in the number of cases with severe haze (greater than 3) which proved more frequent in the monozone group. CONCLUSION: Our results suggest the techniques are comparable in predictability and effectiveness. However, the incidence of severe haze was lower in the multizone group, which may render its use preferable in the treatment of myopias in excess of 6.00 D.

Corneal Opacity↗
PubMed1996

Knowledge gained following Neonatal Resuscitation Program courses.

BACKGROUND: This study evaluated the knowledge gained and retained by family practice residents who participated in the Neonatal Resuscitation Program (NRP) course. METHODS: Knowledge attainment and its retention was assessed by the administration of pre-, post-, and 6-month follow-up tests using the standard NRP written examination. Twenty-nine residents from the Department of Family Medicine at McGill University completed the pretests and posttests, and 10 of these completed the follow-up tests. The data were analyzed using repeated measures analysis of variance and Student's t tests. RESULTS: The average score was 60.6% (n = 29) for pretest, 90.7% (n = 29) for posttest, and 75.4% (n = 10) for the follow-up test. A significant improvement was shown in posttest examination scores when compared to pretest scores and in the follow-up test scores when compared to pretest scores. No significant difference existed between the posttest and follow-up test scores. However, small sample size may have prevented detection of significant differences. Further, follow-up scores for some subjects had fallen to below the level required to pass the course. CONCLUSIONS: The results suggest that participation in an NRP course significantly increased knowledge of neonatal resuscitation by family practice residents, but that knowledge may decrease over time.

Analysis of Variance↗
PubMed1990

The effect of early post-partum mother-infant contact and breast-feeding promotion on the incidence and continuation of breast-feeding.

Three maternity hospital practices of post-partum mother-infant contact and breast-feeding promotion on the incidence and continuation of breast-feeding among 375 urban poor healthy Nicaraguan primigravid women were investigated. Infant feeding patterns were evaluated at 1 week and 4 months post-partum. Eighty-seven per cent of all infants initiated breast-feeding, but only 54% continued breast-feeding for at least 4 months. There was a significant association between both a short 45-min contact period and rooming-in combined with standard breast-feeding promotion, resulting in greater initial rates of breast-feeding (P less than 0.05). There was only a significant relationship between prolonged contact (rooming-in) and standard breast-feeding promotion and the continuation of breast-feeding (P less than 0.05). These findings suggest that in populations in which a majority of women initiate breast-feeding, post-partum mother-infant contact practices combined with standardized breast-feeding promotion may influence the initial choice to breast-feed, but these practices alone are clearly not enough to prolong breast-feeding.

Adult↗
PubMed1990

Regulated expression of nuclear genes by T3 RNA polymerase and lac repressor, using recombinant vaccinia virus vectors.

Recombinant vaccinia viruses that express the bacteriophage T3 RNA polymerase (VV-T3pol) or the Escherichia coli lac repressor (VV-lacI) under control of the early-late vaccinia promoter P7.5 were constructed. To determine whether phage polymerase and lac repressor can function in the nucleus of mammalian cells, the bacterial chloramphenicol acetyltransferase (CAT) gene was cloned downstream of a T3 promoter (PT3-CAT) or downstream of a T3 promoter-lac operator fusion element (PT3Olac-CAT), and these reporter gene cassettes were introduced stably into NIH 3T3 or Ltk- cells. Infection of 3T3/PT3-CAT or Ltk-/PT3-CAT cells by VV-T3pol led to rapid expression of CAT (greater than 20 ng of CAT protein per 10(6) cells). The presence of hydroxyurea (which blocks virus DNA replication) did not prevent CAT production. When 3T3/PT3Olac-CAT cells were infected with both VV-T3pol and VV-lacI (multiplicities of infection of 2.5 and 10, respectively), greater than 30-fold repression of CAT gene activity by lac repressor was observed. This could be reversed to unrepressed levels by the presence of 10 mM o-nitrophenyl-beta-D-galactoside (IPTG) in the medium. Regulated expression of the target gene was observed with cell lines that had been maintained for over 1 year (greater than 50 passages in culture), and Southern blot analysis revealed the presence of the CAT gene only in the nuclear fraction in these cells, demonstrating the stability of the target gene. These results indicate that vaccinia virus-encoded proteins can function in the mammalian nucleus and provide the basis for a genetic system in which essential vaccinia virus genes, placed in the chromosome of a cell, can be used to complement defective virus particles. This approach may prove useful for other virus systems.

Animals↗
PubMed1989

Recurrent gastroesophageal symptoms and precordial pain in a gastrectomized man improved by amitriptyline. Physiologic, metabolic, endocrine, neurochemical and psychiatric findings.

A 57-year-old white man presenting frequent recurrent chest and precordial pain, heartburn (pyrosis) and post-prandial vomiting for the previous 33 years (one to two years after Bilroth II gastrectomy) was submitted to cardiovascular, endoscopic, radiologic and biochemical studies with negative results. Doctors recommended surgical operation because of an excessively long afferent loop, Several biologic markers were performed at our hospital (intestinal pharmacomanometry, i.m. clonidine test, plasma neurotransmitters plus hormones, oral glucose tolerance test, plasma insulin, etc.), revealing an autonomic nervous system (ANS) imbalance characterized by hyperactivity of the cholinergic plus hypoactivity of the noradrenergic central system. Psychiatric evaluation demonstrated Dysthymic Depression. Treatment with a small daily dose of amitriptyline (a drug which enhances central noradrenergic activity and exerts powerful anticholinergic effects) suppressed symptoms, normalized physiological plus hormonal plus neurochemical parameters and made depressive manifestations disappear. The results suggest that the ANS imbalance was related to depressive syndrome and potentiated by neurohumoral disorders depending on duodenal and jejunal exclusion, and on intestinal post-prandial hyper-osmolarity.

Amitriptyline↗