Molecular mimicry and autoimmunity.

Molecular mimicry is one of the leading mechanisms by which infectious or chemical agents may induce autoimmunity. It occurs when similarities between foreign and self-peptides favor an activation of autoreactive T or B cells by a foreign-derived antigen in a susceptible individual. However, molecular mimicry is unlikely to be the only underlying mechanism for autoimmune responses; other factors such as breach in central tolerance, non-specific bystander activation, or persistent antigenic stimuli (amongst others) may also contribute to the development of autoimmune diseases. Host genetics, exposure to microbiota and environmental chemicals are additional links to our understanding of molecular mimicry. Our current knowledge of the detailed mechanisms of molecular mimicry is limited by the issues of prolonged periods of latency before the appearance of disease, the lack of enough statistical power in epidemiological studies, the limitations of the potential role of genetics in human studies, the relevance of inbred murine models to the diverse human population and especially the limited technology to systematically dissect the human T-cell repertoire and B-cell responses. Nevertheless, studies on the role of autoreactive T-cells that are generated secondary to molecular mimicry, the diversity of the T-cell receptor repertoires of auto-reactive T-cells, the role of exposure to cryptic antigens, the generation of autoimmune B-cell responses, the interaction of microbiota and chemical adjuvants with the host immune systems all provide clues in advancing our understanding of the molecular mechanisms involved in the evolving concept of molecular mimicry and also may potentially aid in the prevention and treatment of autoimmune diseases.

Factors contributing to depressive symptoms among Mexican Americans and Latinos.

Survey results from 90 Mexican Americans and Latinos found that individuals who experienced social and economic challenges were more likely to self-report depressive symptoms. The prevalence of depressive symptoms among this sample was 30 percent. Results from a logistic regression analysis identified three significant predictors for depressive symptoms: (1) Individuals concerned about discrimination were twice as likely to self-report depressive symptoms; (2) individuals with concerns about access to medical care had a greater likelihood of having depressive symptoms by 94.8 percent; and (3) those who had experienced a dramatic loss of income were 1.1 times more likely to have depressive symptoms than those who had not experienced income loss. Results from the study also confirmed that the majority of Mexican Americans and Latinos prefer to seek assistance for mental health issues from a medical doctoral or from indigenous community resources, such as family members, friends, and religious consultation. Strategies for overcoming barriers to receive adequate and culturally competent mental health care and for coping with dramatic loss of income may help to alleviate depressive symptoms among the Mexican American and Latino populations.

Effect of exercise dosages on adiposity indices in overweight girls.

OBJECTIVE: The primary purpose of this study was to determine the impact of two exercise dosages on reducing adiposity in minority girls. MATERIALS AND METHODS: Sixty-two overweight Hispanic and African-American girls participated in one of two intense summer interventions in Houston, TX: Intervention A (exposure to about 40 hours physical activities) or Intervention B (exposure to 60 hours of physical activities). Adiposity indices (percent body fat, waist circumference, body mass index) were taken pre- and post-intervention. RESULTS: Intervention B had a significantly greater decrease in adiposity indicators (p= 0.006) when compared to Intervention A. Waist circumference displayed the most significant decrease (p = 0.001). Both interventions significantly increased daily minutes of moderate-to-vigorous physical activity (p= 0.020). CONCLUSIONS: Intense physical activity interventions may effectively reduce abdominal fat in minority girls.

Effect of exercise dosages on adiposity indices in overweight girls / Efecto de programas de ejercicio en los índices de adiposidad en niñas con sobrepeso

Objective. The primary purpose of this study was to determine the impact of two exercise dosages on reducing adiposity in minority girls. Materials and methods. Sixty-two overweight Hispanic and African-American girls participated in one of two intense summer interventions in Houston, TX: Intervention A (exposure to about 40 hours physical activities) or Intervention B (exposure to 60 hours of physical activities). Adiposity indices (percent body fat, waist circumference, body mass index) were taken pre- and post-intervention. Results. Intervention B had a significantly greater decrease in adiposity indicators (p= 0.006) when compared to Intervention A. Waist circumference displayed the most significant decrease (p = 0.001). Both interventions significantly increased daily minutes of moderate-to-vigorous physical activity (p= 0.020). Conclusions. Intense physical activity interventions may effectively reduce abdominal fat in minority girls.

Objetivo. Determinar el impacto de dos programas de ejercicio en la reducción de los índices de adiposidad en niñas de grupos minoritarios. Material y métodos. Sesenta y dos niñas latinas y africano-americanas participaron en una de dos intervenciones intensivas durante el verano: la intervención A (exposición a aproximadamente 40 horas de actividad física) o la intervención B (exposición a 60 horas de actividad física) en Houston, TX. Los indicadores de adiposidad (índice de masa corporal, porcentaje de grasa corporal y grasa abdominal) se midieron antes y después de cada intervención. Resultados. La intervención B tuvo una disminución más significativa en el nivel de adiposidad (p=0.006) comparado con la intervención A. La circunferencia abdominal fue la que más disminuyó (p=0.001). Ambas intervenciones aumentaron significativamente la actividad física moderada a intensa (p=0.020). Conclusiones. Las intervenciones cortas e intensas pueden ser efectivas en la reducción de la grasa abdominal en niñas de grupos minoritarios.

Comparisons of problems reported by youths from seven countries.

OBJECTIVE: This study compared ratings for self-reported behavioral and emotional problems in adolescents from seven countries. METHOD: Youth Self-Report scores were analyzed for 7,137 adolescents ages 11-18 years from general population samples from Australia, China, Israel, Jamaica, the Netherlands, Turkey, and the United States. RESULTS: Comparisons of problems scores yielded small to medium effect sizes for cross-cultural variations. Youths from China and Jamaica had the highest and youths from Israel and Turkey had the lowest mean total problems scores. With cross-cultural consistency, girls scored higher for internalizing and lower for externalizing than boys. Cross-cultural correlations were high among the mean item scores. CONCLUSIONS: Empirically based assessment provided a robust method for assessing and comparing adolescents' self-reported problems. Self-reports thus supplemented empirically based assessments of parent-reported problems and offered a cost-effective way of identifying problems for which adolescents from diverse cultural backgrounds may need help.