Biomedical subjects

M Bravo

Publications and source records attributed to M Bravo.

At least 73 records · Page 4Linked to original sources

PubMed1994

[Study of anti-loxosceles serum action on hemolytic and ulcero-necrotic cutaneous effects of Loxosceles laeta venom].

The action of an anti-loxosceles serum on in vitro human red blood cell hemolysis and on the development of ulcero-necrotic lesions in rabbit skin, induced by loxosceles laeta venom, was studied. An 81 +/- 3% hemolysis was obtained after 72 h incubation of a 2.5% Rh+ red blood cell solution with the equivalent of one Loxosceles laeta venom gland. This parameter was not modified adding anti-loxosceles serum before, along with or after the venom (79.7 +/- 0.8, 77.3 +/- 2.1 and 80.7 +/- 0.7% respectively). After the intradermic injection of a minimal necrotizing venom dose in rabbits, a skin necrotic lesion appeared. This lesion did not appear if anti-loxosceles serum was injected together with the venom; if the serum was injected one hour after the venom, the resulting skin lesion was inflammatory but not necrotic. It is concluded that anti-loxosceles serum does not inhibit loxosceles venom induced hemolysis and causes a time dependent inhibition on skin necrotic lesions.

Animals↗

PubMed1994

[Carotid artery dissection at the cervical level presenting as unilateral paresis of lower cranial nerves].

Internal carotid artery dissection at the cervical level is a known cause of stroke in young patients. The usual clinical presentation is strong ipsilateral cephalea and oculosympathetic paresis or ischemic symptoms in the affected artery. Paresis of the lower cranial nerves due to local compression in the space behind the parotid is rarely found and may complicate the diagnosis by leading physicians to look for anomalies in the vertebro-basilar territory. We present a patient with internal carotid artery dissection at the cervical level diagnosed by angiography. Symptoms at presentation were hemicranial cephalea accompanied by Villaret's syndrome. We point out the importance of keeping this diagnostic possibility in mind when looking for the etiology of subacute paresis of the lower cranial nerves.

Aortic Dissection↗

PubMed1993

The Spanish translation and cultural adaptation of the Diagnostic Interview Schedule for Children (DISC) in Puerto Rico.

This article illustrates a comprehensive cross-cultural adaptation model used to translate into Spanish and to culturally adapt the Diagnostic Interview Schedule for Children (DISC). The process strived to identify similar phenomena to those identified by the original English version in a dissimilar context. To attain cross-cultural equivalency five important dimensions were addressed: semantic, technical, content, criterion and conceptual. To meet this challenge various steps were taken, including bilingual committee, back-translation, reliability and validity testing. The result is an instrument which could be used, not only in Puerto Rico, but also in other Spanish-speaking child and adolescent populations after appropriate cultural adaptations.

Adolescent↗

PubMed1993

G2 repair and aging: influence of donor age on chromosomal aberrations in human lymphocytes.

The caffeine effects on chromosomal aberration frequency and mean G2 duration were studied in human lymphocytes in vitro from three age groups of normal donors (I: 1-5 years old; II: 30-40 years old; III: 60-70 years old). Under control conditions, the three age groups showed a similar frequency of chromosomal aberrations. All three age groups exhibited a linear dose response for aberrations with caffeine treatments. However, lymphocytes from aged individuals (groups II and III) showed higher chromosomal aberration frequencies and longer G2 duration than cells from young individuals (group I). The caffeine effect in reducing G2 length was rather similar in every age group. The reversion of caffeine effects by adenosine or niacinamide in lymphocytes from older individuals was higher than in cells from group I. The different caffeine effects and G2 values between lymphocytes from old and young individuals are most likely due to a higher number of DNA lesions reaching G2 phase and/or a decrease of the G2 repair capability of lymphocytes from older individuals.

Adenosine↗

PubMed1993

The prevalence of ataques de nervios in the Puerto Rico disaster study. The role of culture in psychiatric epidemiology.

This paper presents one of the few epidemiological studies of a popular category of distress, ataques de nervios (attacks of nerves), in the cross-cultural psychiatric literature. As part of a major study of the psychological consequences of the 1985 floods and mudslides which caused considerable damage and death in Puerto Rico, a question was added to the Diagnostic Interview Schedule/Disaster Supplement concerning ataques de nervios. This additional item provided the opportunity to carry out the first study of this important Puerto Rican popular category of distress using a representative, community-based sample. This paper addresses several key questions about ataques de nervios which come from previous psychiatric and anthropological literatures concerning the social correlates of who experiences an ataque de nervios and the relationship of ataques to social distress and psychiatric disorder. People who reported an ataque de nervios were more likely to be female, older, less educated, and formerly married. They were also more likely to meet criteria for anxiety and depressive disorders than those who had not experienced an ataque. The picture that emerges from our analyses is that those who suffer from a combination of social disadvantage, psychiatric disorder, and poor perceived health are more likely to experience an ataque de nervios.

Adolescent↗

PubMed1993

Factors influencing the effectiveness of sealants--a meta-analysis.

Meta-analysis of published studies was applied to analyze the effectiveness of fissure sealants in preventing dental caries. Studies were identified by a MEDLINE search, supplemented by a hand search of the references in the articles recovered. All articles were assessed on the basis of quality, and were combined with the Mantel-Haenszel method. The prevented fraction in the exposed population (PF) was estimated using pooled relative risk. Heterogeneity of the effect and publication bias were also analyzed. Twenty-four studies were included in the meta-analysis. The overall effectiveness of autopolymerized fissure sealants was 71.36% (95% confidence interval 69.69-72.94%). Effectiveness in preventing caries decreased with time, and increased when drinking water was fluoridated (82.69% vs 72.28%). Heterogeneity was significant in most cases, and was further studied with multiple linear regression analysis. It is concluded that autopolymerizing sealants should be used. More research is needed to compare the effectiveness of dental hygienists and dentists in applying sealants.

Adolescent↗

PubMed1993

[Hemolysis induced by Loxosceles laeta venom. In vitro experience].

To study the effects of loxosceles laeta venom on red blood cells and the possible factors involved in hemolysis during arachnidism, in vitro models were designed to measure the role of loxosceles venom, calcium, complement and antibodies in the mechanism of red blood cell destruction. The degree of basal hemolysis was measured in a 5% suspension of group O, Rh (+) red blood cells in pH 7.4 buffer. In a similar suspension spider venom was added in amounts equivalent to one venom gland. After 72 hours of incubation, basal hemolysis was 5.59 +/- 2.04% which increased to 26.01 +/- 7.9% adding venom (p < 0.001). Adding calcium to the incubation medium, hemolysis increased to 88.5 +/- 7.16% (p < 0.001). Incubating red blood cells with control human serum and venom, hemolysis was 14.58 +/- 2.42%, which decreased significantly to 6.85 +/- 3.35% when serum was heat inactivated; this demonstrates an effect of the presence of complement. We did not find antivenom antibody production in patients with arachnidism 10, 15 or 30 days after the spider bite. It is thus demonstrated that loxosceles laeta venom has a direct lytic action on red blood cells that is calcium and complement dependent and is not mediated by antibodies or other substance.

Animals↗

PubMed1993

[Neurologic complications induced by the treatment of the acute renal allograft rejection with the monoclonal antibody OKT3].

The treatment of the acute renal allograft rejection with the monoclonal antibody orthoclone OKT3 produces both systemic and neurologic alterations. In a series of 21 patients with an acute renal allograft rejection treated with this monoclonal antibody, 20 with a renal allograft transplantation and one with a renal and pancreatic allograft transplantation, 29% referred headache associated with fever and vomiting, and 14.2% presented severe neurological alterations induced by the treatment. We stress the need to know these secondary effects to differentiate them from other central nervous system disorders, particularly those of infectious origin.

Adolescent↗

PubMed1993

[Leiomyosarcoma of the saphenous vein].

A 48 years old male presenting with a painless tumor of the right thigh is reported. An initial surgical excision showed that the tumor was joint to the saphenous vein. The histopathological study showed that it was a venous vascular leiomyosarcoma of intermediate degree of malignancy. The patients was re-operated performing a resection of the abductor muscle and two weeks later was subjected to radiotherapy (50 Gray). The only postoperative sequel was a moderate lymphedema of the right limb. This is the first reported case in the Chilean literature.

Humans↗

PubMed1992

Somatic symptoms after a natural disaster: a prospective study.

The authors prospectively examined the prevalence of somatization symptoms among community respondents after a natural disaster in Puerto Rico. Exposure to the disaster was related to a higher prevalence of medically unexplained physical symptoms, particularly gastrointestinal ones (abdominal pain, vomiting, nausea, excessive gas) and pseudoneurological ones (amnesia, paralysis, fainting, unusual spells/double vision).

Disasters↗

PubMed1992

Mental health status among Puerto Ricans, Mexican Americans, and non-Hispanic whites.

Compared mental health characteristics of island Puerto Ricans to three groups from the Los Angeles Epidemiologic Catchment Area Study: Mexican American immigrants, U.S.-born Mexican Americans, and Non-Hispanic whites. The Diagnostic Interview Schedule was used to obtain both diagnostic and symptom scale information about affective disorders, alcohol abuse/dependence, somatization, phobic disorder, and psychotic disorder. Mexican American immigrants had the fewest mental health problems of all groups. Puerto Ricans had more somatization disorder, but less affective and alcohol disorders than U.S.-born Mexican Americans or non-Hispanic whites. Results are considered in the light of selection factors, relative disadvantage of groups and methodological problems.

Adolescent↗

PubMed1992

[Ataxia telangiectasia: effects of cycloheximide on G2 repair of chromosome damage in lymphocytes cultured in vitro].

The chromosomal sensitivity to the spontaneous and induced DNA damage detected in lymphocytes from patients affected with ataxia telangiectasia (AT) might be related with disturbances in DNA repair mechanisms. We have studied the effect of caffeine, an inhibitor of G2 repair and the enlargement of G2 by 0.5 ug/ml cycloheximide on chromosomal aberration frequencies in AT lymphocytes, both in control and X-ray irradiated conditions. The increase of spontaneous and X-ray induced chromosomal aberrations by caffeine treatments during G2 in AT lymphocytes was higher than in control cells. The number of spontaneous and X-ray induced lesions repaired during G2 in AT cells was higher than in normal cells. The enlargement of G2 duration by 0.5 ug/ml cycloheximide decreased the spontaneous and X-ray induced chromosomal aberrations in AT cells, whereas no such effect was observed in control cells. We postulate that disturbances in the mechanism that control G2 duration might be involved in the high frequency of spontaneous and induced chromosomal aberrations detected in AT lymphocytes.

Ataxia Telangiectasia↗

PubMed1991

A cross-cultural adaptation of a psychiatric epidemiologic instrument: the diagnostic interview schedule's adaptation in Puerto Rico.

The advent of the use of structured interview schedules that generate psychiatric diagnoses in epidemiologic studies has promoted an intense interest in its cross-cultural use. However, the valid use of these instruments across cultures requires a careful adaptation process which goes beyond mere language translation. In this article the authors illustrate the application of a comprehensive cross-cultural adaptation model to both the translation into Spanish and the adaptation to the population of Puerto Rico of a widely used psychiatric epidemiologic research instrument: the Diagnostic Interview Schedule (DIS). The process aimed to ensure the development of a research instrument that is not only in correct Spanish and comprehensible for most Spanish-speaking people, but also culturally adapted to Puerto Rico's population. Various steps were taken (including bilingual committee, back-translation, instrument testing and diagnostic comparisons) to address cross-cultural validity in five important dimensions (i.e., semantic, technical, content, criterion and conceptual equivalence). The result is an interview schedule that is not only linguistically and culturally adequate for the targeted population but also includes elements which can contribute to the development of the instrument both in its original English language and in its translated versions.

Cross-Cultural Comparison↗

PubMed1991

Production of platelet-derived growth factor by human lung cancer.

The production of platelet-derived growth factor (PDGF) was studied in small cell lung carcinoma, lung squamous carcinoma and lung adenocarcinoma cell lines, and in seven human lung tissues obtained from each type of lung cancer. By indirect immunofluorescence, PDGF was detected in all the cell lines. Likewise, five out of seven biopsies derived from patients with adenocarcinoma and squamous carcinoma, and four out of seven specimens with small cell carcinoma displayed a positive pattern for PDGF. In addition, lung carcinoma cell lines expressed both PDGF-A and PDGF-B/sis genes, as judged by Northern blot analysis. Biologically active, serum-free conditioned media obtained from all three cell lines stimulated the incorporation of [3H]thymidine into quiescent BALB/c-3T3 cells. This effect was abolished when IgG-PDGF antiserum was used. These findings suggest that an abnormal expression of PDGF occurs in the three more frequent types of lung cancer, which can play a potential role in neoplastic transformation and uncontrolled cell growth.

Adenocarcinoma↗

PubMed1991

Children of alcoholic parents in the community.

The relationship between parental alcoholism and risk for maladjustment in the offspring was investigated in a community sample. Children of parents who met criteria for DIS/DSM-III alcohol abuse or dependence and children of parents who met criteria for ten other diagnoses were compared to children of "normal" parents. The data were obtained from the merging of the data banks of two major psychiatric epidemiology studies of the adult (17-64) and child (4-16) population of Puerto Rico. Results indicated that parental alcoholism in addition to creating an adverse family environment had an effect on the relative risk for maladjustment in the offspring (as measured by scores on the Child Behavior Checklist). Although previous studies have reported higher levels of externalizing behaviors in children of alcoholics, an increased risk for internalizing symptoms was observed in the children studied. Similar findings were obtained for the children of parents with other psychiatric disorders suggesting that the effects of parental alcoholism in children ages 4 to 16 may not be different from the consequences of parental mental illness per se.

Adolescent↗

PubMed1991

[Importance of the family as a resource in social support in Puerto Rico].

In this article we examine the role of the family in the provision of social support by studying the identity of persons which the participants consider available for providing support. We define social support as that human relationship in which socio-emotional (closeness, intimacy counseling), instrumental (goods and services) and recreational (companionship for recreation) resources are interchanged. Based on a probabilistic sample of the adult (17-68 yrs.) population, 912 persons were successfully interviewed (response rate = 90.4%) using a structured interview schedule. Results indicate that close relatives (parents, brothers/sisters, sons/daughters) are the main resource of all types of support, not only of the general population but also of specific demographic groups defined by their gender, age (17-39, 40-68) and schooling (0-11, 12 + yrs). The marital partner was also identified as an important support resource, especially emotional and recreational; more distant relatives were also important for providing instrumental support. Although the compared groups showed many similarities, they also differed in various aspects both when individually and jointly analyzed. It is concluded that the family is very important in the provision of social support in Puerto Rico (PR).

Adolescent↗

PubMed1991

[Use of health services in Puerto Rico by persons with mental disorders].

As part of a major study on the prevalence of mental disorders in Puerto Rico, this paper describes the mental health care utilization patterns of persons with a DIS/DSM-III disorder within the last year. The main findings of this analysis show that (a) There is a high rate of health service utilization, (b) The public sector is the main provider of services, (c) People with a DIS disorder tend to resort to the non-psychiatric physician, (d) People with alcohol abuse and/or dependence tend to use the services of general practitioners while schizophrenics, somatizers, and people with cognitive impairment tend to apply for the services of mental health specialists. Seeking help from other sources such as clergymen or spiritualists does not substitute the use of health services.

Adolescent↗

PubMed1991

[The Composite International Diagnostic Interview (CIDI): an epidemiologic instrument suitable for using in conjunction with different diagnostic systems in different cultures].

The Composite International Diagnostic Interview (CIDI), written at the request of the World Health Organization/US Alcohol, Drug Abuse, and Mental Health Administration Task Force on Psychiatric Assessment Instruments, combines questions from the Diagnostic Interview Schedule with questions designed to elicit Present State Examination items. It is fully structured to allow administration by lay interviewers and scoring of diagnoses by computer. A special Substance Abuse Module covers tobacco, alcohol, and other drug abuse in considerable detail, allowing the assessment of the quality and severity of dependence and its course. This article describes the design and development of the CIDI and the current field testing of a slightly reduced "core" version in Puerto Rico. The field test was being conducted in 19 centers around the world to assess the interviews' reliability and its acceptability to clinicians and general people in different cultures and providing data on which to base revisions that may be found necessary. In addition, questions to assess International Classification of Diseases, ninth revision, and the revised DSM-III diagnoses are being written. If all goes well, the CIDI will reliably allow investigators to assess mental disorders according to the most widely accepted nomenclatures in many different populations and cultures.

Cross-Cultural Comparison↗