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Biomedical subjects

M Barrera

Publications and source records attributed to M Barrera.

At least 37 records · Page 2Linked to original sources
PubMed1998

Prospective differential prediction of adolescent alcohol use and problem use: examining the mechanisms of effect.

This prospective study tested the assertion that psychopathology would predict both adolescent alcohol use and problem use, whereas socialization factors would predict only use, and explored mechanisms by which predictors led to problem use in a community sample of families (N = 216). Externalizing symptoms, parental alcoholism, peer influences, and parental support were indirectly related to negative consequences through their effects on use level. Externalizing symptoms, internalizing symptoms, peer influences, and parental approval of use directly predicted consequences, controlling for the indirect effects through use level. Internalizing pathology potentiated the relation between consumption and consequences, whereas parental support and control mitigated this relation. Collectively, findings provided mixed support for the assertion that psychopathology would predict both use and problem use, whereas socialization factors would predict only use.

Adolescent↗
PubMed1998

Transformation of ministries of health in the era of health reform: the case of Colombia.

Ministries of health are being called upon to lead major health reforms; at the same time they must reform themselves to become more modern institutions and assume new and different functions and roles in the more dynamic reformed system. The literature on public administration and on health reform has recommended many processes of institutional reform and development, building on private sector management techniques, popularized by 'reinventing government' and 'total quality management'. More recently, thoughtful insights have emphasized improving public management through a focus on creating 'public value'; on political, as well as administrative, leadership; improving institutional performance through strengthening the 'task networks' of organizations needed to achieve strategic objectives; and creating a learning culture within the organization. This article applies these recent approaches to the specific needs of ministries of health in order to improve their capacity to lead major health reforms. This combined approach is then used to analyze and make recommendations to the Ministry of Health in Colombia where the authors were providing technical support for a major new health reform.

Colombia↗
PubMed1995

Effects of parental alcoholism and life stress on Hispanic and Non-Hispanic Caucasian adolescents: a prospective study.

Investigated ethnicity and parental alcoholism as factors that might influence the stress vulnerability of adolescents. It extended an initial cross-sectional study of this same sample by adding two annual assessments which allowed for additional cross-sectional analyses and longitudinal tests. Hispanic and Caucasian adolescents (N = 306 at Time 1) completed measures of their own life stress, family conflict, and alcohol use. Their parents reported on adolescents' internalizing and externalizing symptoms. Cross-sectional analyses at Time 2, and prospective analyses involving Time 1 and Time 2 measures were, for the most part, consistent with the original study's results. Caucasian adolescents and children of alcoholic parents appeared to be more vulnerable to stress than Hispanic adolescents and children of nonalcoholic parents. Family conflict was a partial explanation for this increased vulnerability.

Adolescent↗
PubMed1995

[Surgical cryoablation in a child with malignant ventricular tachycardia refractory to drugs and radiofrequency ablation].

A ten-months-old child with incessant monomorphic ventricular tachycardia is presented. Tachyarrhythmia is refractory to antiarrhythmic drugs and refractory to endocardial radiofrequency current ablation. Epicardial cryoablation of arrhythmogenic area without artificial circulation resulted in the abrupt termination of tachycardia. No tachyarrhythmias were inducible postoperatively. The reduction of ventricular rate by surgical cryoablation does produces resolution of the arrhythmia-induced cardiomyopathy.

Anti-Arrhythmia Agents↗
PubMed1995

[Diagnosis of Babesia bigemina with the immunoperoxydase test].

An immunoperoxidase assay for the serological diagnosis of Babesia bigemina was developed. The antigen slides were prepared from B. bigemina-infected blood and stored at -20 degrees C. One hundred and sixty five sera were tested, comparing the immunoperoxidase assay to the indirect fluorescent antibody test. A coincidence of 95% was observed between both tests. For the immunoperoxidase assay, a relative sensitivity of 94.8%, a relative specificity of 95.5%, and a positive predictive value of 96.8% were calculated. The results demonstrated the efficacy of this technique for detecting antibodies to B. bigemina.

Animals↗
PubMed1994

Detection of antibodies to Babesia bovis using an ELISA test.

An enzyme-linked immunoassay (ELISA) is described for the detection of antibodies to Babesia bovis using a partially purified antigen. The optimum conditions required to perform the test were determined and 210 serum samples were comparatively tested using ELISA and indirect immunofluorescence (IFA) tests, finding a diagnostic coincidence of 96.1%, a relative sensitivity of 96%, and a relative specificity of 96.4%.

Animals↗
PubMed1993

Relation of parental support and control to adolescents' externalizing symptomatology and substance use: a longitudinal examination of curvilinear effects.

Past research has generated inconsistent findings regarding the relation of parental control and support to adolescent problem behaviors. Using two waves of data collected 1 year apart, the current study examined the influence of parental control and support on adolescents' externalizing symptoms, alcohol use, and illicit substance use. A sample of adolescents and their parents (N = 454) was studied, within which approximately half of the adolescents were at high risk because of parental alcoholism. Multiple-regression analyses of cross-sectional data showed a negative quadratic relation between parental control and adolescent externalizing symptomatology, and between parental control and adolescent illicit substance use. Parental control had a negative linear relation to adolescent alcohol use. Parental support showed a negative quadratic relation to adolescent illicit substance use, and negative linear relations to adolescent alcohol use and externalizing symptoms. Although longitudinally adjusted contemporaneous results were consistent with cross-sectional findings, parental support and control were prospectively related only to adolescent alcohol use. The quadratic relations suggest that adolescents who receive either extreme of parental support or control are at risk for problem behaviors.

Adolescent↗
PubMed1993

Ethnic group differences in vulnerability to parental alcoholism and life stress: a study of Hispanic and non-Hispanic Caucasian adolescents.

Tested Hispanic and Caucasian adolescents' vulnerability to parental alcoholism and life stress. Sixty-nine Hispanic and 237 Caucasian adolescents completed measures of life stress, social support, and alcohol use. Their parents reported on the adolescents' psychological symptoms and their own alcohol and substance use. Parental alcoholism and life stress were related to almost all indicators of adolescents' psychological distress and alcohol use. In addition, results showed some evidence that Caucasian adolescents were more vulnerable to the effects of life stress and parental alcoholism than Hispanics. Neither social support nor the higher substance use of Caucasian parents provided a good explanation for this differential vulnerability.

Adolescent↗
PubMed1993

Relation of parental alcoholism to early adolescent substance use: a test of three mediating mechanisms.

The current study assessed 3 hypothesized mediating mechanisms underlying the relation between parental alcoholism and adolescent substance use. Using structural equation modeling, we analyzed data obtained from a large community sample of adolescent children of alcoholics and a demographically matched comparison group. Results suggested that parental alcoholism influenced adolescent substance use through stress and negative affect pathways, through decreased parental monitoring, and through increased temperamental emotionality (which was associated with heightened negative affect). Both negative affect and impaired parental monitoring were associated with adolescents' membership in a peer network that supported drug use behavior. The data did not support a link between parental alcoholism and temperamental sociability.

Adolescent↗
PubMed1993

Effects of social support and conflict on adolescent children of alcoholic and nonalcoholic fathers.

Studies of positive and negative social ties usually are done in isolation of each other, precluding an understanding of their relative contributions to psychological functioning. This research evaluated the effects of adolescents' conflict with and social support from key relationships (parents, siblings, and best friends) on adolescents' self-esteem, substance use, and externalizing symptoms. Ss were 296 adolescents and their parents; 145 families had alcoholic fathers, and 151 had nonalcoholic parents. Support and conflict provided by each network member showed only a mild negative correlation. Support from parents, but not siblings or best friends, was related to adolescents' reports of substance use and externalizing. Conflict with parents was consistently related to externalizing behaviors. There was no evidence that conflict within a relationship neutralizes the effectiveness of the support it provides.

Adolescent↗
PubMed1992

[Logistic model for predicting the prognosis in patients with intra-abdominal infection based on the APACHE II index].

BACKGROUND: The APACHE II method has been widely used to classify patients according to disease severity. The high mortality and the lack of reliable prognostic parameters justify the study and application of indexes of severity (IS) and prognostic indexes (PI) in patients with intraabdominal sepsis. METHODS: A prospective study is presented concerning 100 patients with intraabdominal sepsis in whom a prognostic index derived from the APACHE II method by means of a logistic regression model was applied. In this model the APACHE II score is used as the only independent variable with the aim of predicting the outcome (mortality or survival) at the time of hospital admission. RESULTS: The predictive values obtained, with a 70% probability of mortality taken as the cut-off point, were: sensitivity 100%, specificity 87.7% and total predictive capacity 91%. CONCLUSIONS: It was concluded that the logistic prediction model of prognosis shows a high correlation with patient outcome and the application of the APACHE II score is useful in patients with intraabdominal infection.

Abdomen↗
PubMed1992

Family and peer social support as specific correlates of adolescent depressive symptoms.

Depression models that emphasize the social environment have not been tested with adolescents and their specificity to depressive symptoms has not been demonstrated. In a study of 94 adolescent inpatients, distinctions were drawn between family and peer support to determine if these sources of support were differentially related to depression symptoms. Step-down multivariate multiple-regression analyses showed that depression symptoms were uniquely predicted by social relationship variables after accounting for the effects of anxiety and conduct disorder symptoms. Depression was negatively related to family and paternal support, but it was positively related to peer support. Furthermore, family and paternal support interacted with peer support in the prediction of depression. The results are consistent with the assertion that disturbances in important supportive attachments have special significance for the experience of depressive symptoms by adolescents.

Adolescent↗
PubMed1992

Recruiting a community sample of adolescent children of alcoholics: a comparison of three subject sources.

Although there has been substantial research interest in adolescent children of alcoholics, the generalizability and consistency of previous findings have been limited by the specialized nature of the research samples (e.g., treatment samples, school-based samples). However, attempting to address this problem by recruiting subjects from community sources raises a variety of sampling issues, including the comparability and accessibility of subjects from different sources. This article compares the recruitment rates and characteristics of families enrolled from three sources--DUI records, HMO records and telephone surveys. Implications for research on children of alcoholics are discussed.

Adolescent↗
PubMed1991

Social support interventions and the third law of ecology.

Most of what we know about the effectiveness of social support is based on field studies of naturalistic relationships and transactions. Social support interventions, particularly those that attempt to create new support providers, stretch the limits of our knowledge base. The article by Heller et al. (1991) highlights gaps in our knowledge, suggests the importance of intimacy in support exchanges, and identifies possible limitations in trying to compensate for deficiencies in family support with new friendships.

Aged↗
PubMed1991

Substance use and symptomatology among adolescent children of alcoholics.

This study assessed the magnitude and specificity of parental alcoholism as a risk factor for internalizing symptomatology, externalizing symptomatology, and alcohol and drug use in adolescence. We evaluated parents' and children's reports of symptomatology and children's reports of alcohol and drug use in a community sample of 454 adolescents. The results showed that parental alcoholism was a moderate to strong risk factor, with stronger risk associated with recent (rather than remitted) parental alcoholism. Multivariate analyses showed that the specificity of risk varied with the outcome measure. In predicting externalizing symptomatology, the risk associated with parental alcoholism was mediated by co-occurring parental psychopathology and environmental stress. However, in predicting alcohol use, the father's alcoholism was a specific risk factor above and beyond the more generalized effects of stress and family disruption.

Adolescent↗