Gender differences in condom-related behaviors and attitudes among Mexican adolescents living on the U.S.-Mexico border.

Adolescents are at increasing risk for HIV infection in Mexico. Research on gender differences in risk behaviors and determinants is needed to develop effective HIV prevention interventions targeting Mexican adolescents. This study examined gender differences in the likelihood of unprotected sex and theoretical correlates among high school students in the border city of Tijuana. Three hundred seventy high-school students completed a face-to-face interview and a self-administered survey. Differences in sexual initiation, condom use, intentions to use condoms in the future, and attitudes towards condoms in this population were assessed. Although male students initiated sexual practices earlier than females, females were more likely to have unprotected sex. Females perceived themselves as more likely to avoid unprotected sex in the future and held more favorable attitudes about condoms. The results suggest that stereotypical gender roles and communication barriers place Tijuana female high school students at higher risk for HIV infection than their male peers.     

Smoking, exposure to secondhand smoke, and smoking restrictions in Tijuana, Mexico.

OBJECTIVE: To estimate the prevalence of tobacco use, exposure to secondhand smoke, and smoking restrictions in the home and workplace among residents of Tijuana, one of Mexico's largest cities. METHODS: This cross-sectional household survey was conducted in Tijuana, Baja California, Mexico, during 2003 and 2004. A population-based sample of 400 Tijuana adult residents responded to a tobacco survey, and 397 of the surveys were analyzed. RESULTS: About 22.9% (95% confidence interval (CI): 18.7%-27.1%) of Tijuana adults reported current smoking, and 53.9% (95% CI: 48.8%-58.9%) reported chronic exposure to secondhand smoke. Approximately 44.4% (95% CI: 37.9%-50.9%) of Tijuana adults had a nonsmoking policy in their workplace, while 65.8% (95% CI: 61.0%-70.6%) of Tijuana households were smoke-free. CONCLUSIONS: The results underline the need for increased tobacco control efforts, particularly stricter enforcement of existing passive smoking regulations, in order to expand protection from secondhand smoke from private settings to public ones and to curb the tobacco epidemic in Tijuana and elsewhere in Mexico.     

A Two-Way Road: Rates of HIV Infection and Behavioral Risk Factors Among Deported Mexican Labor Migrants

A large number of Mexican migrants are deported to Mexico and released in the North Mexican border region every year. Despite their volume and high vulnerability, little is known about the level of HIV infection and related risk behaviors among this hard-to-reach population. We conducted a cross-sectional, probability survey with deported Mexican migrants in Tijuana, Mexico (N = 693) and estimated levels of HIV infection and behavioral risk factors among this migrant flow. The sample and population estimated rates of HIV for deported males were 1.23 and 0.80 %, respectively. No positive cases were found among the female sample. We found high lifetime rates of reported sexually transmitted infections (22.3 %) and last 12-months rates of unprotected sex (63.0 %), sex with multiple sexual partners (18.1 %), casual partners (25.7 %), and sex workers (8.6 %), compared to U.S. and Mexico adults. HIV prevention, testing, and treatment programs for this large, vulnerable, and transnational population need to be implemented in both the U.S. and Mexico.     

Variation between sheep in renal excretion of [14C]allantoin

The objectives of the present study were to investigate the recovery of [14C]allantoin in urine of sheep dosed intravenously and degradation of allantoin by rumen micro-organisms. The recovery of [14C]allantoin in the urine of eight sheep was measured during three periods in two experiments. Individual values of [14C]allantoin recovery varied from 66 to 95 % (mean value 83 (se 1.6) %). The recovery of [14C]allantoin showed no relation to the level of feed intake. There was some evidence that glomerular filtration rate was an important factor affecting the amount of urinary allantoin recovered in one experiment. Incomplete recovery of plasma [14C]allantoin in the urine indicated losses of plasma [14C]allantoin via non-renal routes. This is supported by the disappearance of 14C from rumen contents incubated in vitro with [14C]allantoin for 48 h (88 %) and the presence of 14C in saliva in vivo from sheep sampled after dosing with [14C]allantoin. However, the amount of 14C activity in the saliva was very low (equivalent to only 1.5 % of the total dose in sheep producing saliva at a rate of 15 litres/d). The proportion of renal and non-renal excretion of purine derivatives was found to be unpredictable both between and within individual animals. The factors responsible for this variability need to be identified, and existing models of excretion of purine derivatives may need to be modified accordingly to improve their accuracy of prediction. A single intravenous injection of [4,5-14C]allantoin provides a simple alternative to infusion methods used to measure the proportion of plasma allantoin excreted in the urine of sheep. Using this method it may be feasible to validate PD excretion models in other ruminant livestock.     

The effects of lay counseling on medication adherence and blood pressure: adjunctive treatment for hypertension

Ten noncompliant hypertensive patients were monitored and received counseling from trained aides. Monitoring and lay counseling was associated with a reduction of -10 mmHg in systolic blood pressure and of -7 mmHg in diastolic pressure (P less than 0.05). Medication adherence increased from 69% to 84%. Counseling resulted in pressure decreases equal to those obtained by usual care for similar but compliant patients. This analysis provides a model for paraprofessional adjunctive counseling of patients thought to be adhering poorly to their medication regimen, which may improve control of hypertension.     

Involuntary smoking and asthma

Involuntary smoking is the third leading preventable cause of death, and among children it causes lower respiratory infections, middle ear disease, sudden infant death syndrome, and asthma. Half the world's children may be exposed to environmental tobacco smoke (ETS), exacerbating symptoms in 20% of children with asthma. Recent studies have reinforced previous conclusions that ETS exposure causes onset of childhood asthma and exacerbation of symptoms throughout life. The exact mechanisms by which this is accomplished are still unclear, as are the relative contributions of prenatal versus postnatal exposure. However, favorable health outcomes can be attained with reduced exposure. Among the few studies of ETS exposure reduction interventions, low-intensity advice methods appeared ineffective, and counseling parent smokers appeared successful. Direct counseling of school-aged children to avoid ETS has yet to be tested. Community norms may need to shift further in favor of protecting children and others from ETS before minimal interventions can be successful. This will require combined and ongoing efforts of the medical and public health establishments, in concert with legislation mandating tobacco-free public places and with ETS-related media campaigns.     

计划生育工作人员咨询服务状况调查

目的:了解计划生育工作人员的咨询服务状况及可能的影响因素,为下一步在该人群中开展咨询培训提供依据。方法:通过结构式问卷,调查了来自于全国31个省、市、自治区和直辖市的271名计划生育工作人员,对他们的咨询服务状况及可能的影响因素进行分析。结果:271名调查对象中,255人曾为服务对象提供过咨询服务。咨询服务相关知识得分最高为100.0分,中位数为76.9分;咨询服务知识得分单因素分析显示,不同年龄组、不同文化程度对象之间的差别有统计学意义(P<0.05);多分类反应变量多元Logistic回归分析显示,文化程度越高,研究对象的咨询服务知识得分越高。结论:计划生育工作人员咨询服务的总体状况良好,但研究对象的年龄,文化程度等因素可能对他们的咨询服务产生影响。建议加强咨询培训的针对性,提高计划生育工作人员的整体素质。     

Undernutrition in sheep. Nitrogen repletion by N-depleted sheep

Wether lambs of 29-44 kg live-weight, totally nourished by the infusion of volatile fatty acids (VFA) into the rumen and casein into the abomasum, were given five treatments in consecutive periods. The treatments were (daily amounts per kg live weight (W)0.75): (a) high-protein for 7 d (2500 mg nitrogen, 650 kJ VFA); (b) low-protein for 7-15 d (525 mg N, 650 kJ VFA); (c) N-free for 7 d (no N, 450 kJ VFA); (d) very-low-protein for 24-28 d (300 mg N, 400 kJ VFA); (e) high-protein for 40 d (2500 mg N, 650 kJ VFA). Nine lambs were subjected to treatments (a), (b) and (c) (Expt 1) and four of the lambs additionally received treatments (d) and (e) (Expt 2). In Expt 1 all nine lambs had a positive N retention on treatment (a) but abrupt change to treatment (b) resulted in substantial negative N balances initially, and a period of approximately 5 d adaptation was required before N equilibrium was re-established. Animals again exhibited negative N balances when the N-free infusion (treatment c) was introduced and during that period there was no evidence of adaptation. Basal urinary N excretion was estimated to be 356 (SE 12) mg N/kg W 0.75. In Expt 2 all four lambs were depleted of N when receiving the very-low-protein treatment (d). The progressively decreasing N losses recorded during days 1 to 12 of the treatment period were slightly greater than those recorded during days 13 to 28 but the difference between the means was not significant (P greater than 0.05). There was no evidence of an adaptation in N retention between days 13 and 28 of the treatment. As assessed during days 13 to 28 of the treatment the efficiency of utilization of infused casein N was 1.0; this compared with a value of 0.66 recorded during treatment (b) in Expt 1. Live weight loss during the period of N depletion was 101 (SE 27) g/d. When lambs were given treatment (e) during the last period of Expt 2, N repletion was rapid and complete within a few days. Ten days after the introduction of the treatment the rate of N retention was estimated to be 1019 (SE 38) mg/kg W 0.75 per d and this value declined at a rate of 9.5 (SE 1.9) mg N/kg W 0.75 per d for the following 30 d.(ABSTRACT TRUNCATED AT 400 WORDS)     

Identification of correlates of physical activity among Latino adults

127 Latino adults responded to a survey concerning physical activity. Respondents over-represented well educated and middle class Latinos. Subjects reported a mean of 48 minutes/week of walking for exercise. This sample reported less than two episodes per week of vigorous physical activity, again below the recommended 3/wk needed to insure cardiovascular fitness. We expect more representative samples to engage in less physical activity. Stepwise multiple regression analyses were conducted using 24 variables based on Social Learning Theory. A multiple R of 0.66 accounted for over 27% of the variance in walking for exercise (p<0.001). Older adults, those with a history of childhood injury, and those who reported friend support were more likely to walk for exercise. Respondents who participated in physical activity during childhood and adolescence (including formal physical education in school) and, paradoxically, those who had models for exercise in childhood were less likely to walk for exercise. A multiple R of 0.75 accounted for 43% of the variance in vigorous physical activity and reached significance (p<0.001). Self-efficacy, friends' support, childhood physical activity, and eating a heart healthy diet were positively related to vigorous activity. These results suggest that different correlates influence walking versus vigorous activity, and that correlates of physical activity are different for Latinos compared to Anglos. The findings emphasize the need for larger scale investigations of the determinants of activity within the Latino population.M. Hovell, E. Barrington, M. Hackley, J. Elder, F. Castro, Kristin Kilbourne; Division of Health Promotion, Graduate School of Public Health, San Diego State University, San Diego, CA 92182, J. Sallis; Department of Psychology, San Diego State University, San Diego, CA 92182, R. Hofstetter; Department of Political Science, San Diego State University, San Diego, CA 92182.This research was supported by grants to Drs. Hovell and Sallis: ASPH/CDC Cooperative Agreement Contract; NHLBI (40575).