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Biomedical subjects

R Harrist

Publications and source records attributed to R Harrist.

16 recordsLinked to original sources
PubMed2001

Safer choices: reducing teen pregnancy, HIV, and STDs.

OBJECTIVES: This study evaluated the long-term effectiveness of Safer Choices, a theory-based, multi-component educational program designed to reduce sexual risk behaviors and increase protective behaviors in preventing HIV, other STDs, and pregnancy among high school students. METHODS: The study used a randomized controlled trial involving 20 high schools in California and Texas. A cohort of 3869 ninth-grade students was tracked for 31 months from fall semester 1993 (baseline) to spring semester 1996 (31-month follow-up). Data were collected using self-report surveys administered by trained data collectors. Response rate at 31-month follow-up was 79%. RESULTS: Safer Choices had its greatest effect on measures involving condom use. The program reduced the frequency of intercourse without a condom during the three months prior to the survey, reduced the number of sexual partners with whom students had intercourse without a condom, and increased use of condoms and other protection against pregnancy at last intercourse. Safer Choices also improved 7 of 13 psychosocial variables, many related to condom use, but did not have a significant effect upon rates of sexual initiation. CONCLUSIONS: The Safer Choices program was effective in reducing important risk behaviors for HIV, other STDs, and pregnancy and in enhancing most psychosocial determinants of such behavior.

Adolescent↗
PubMed1999

Short-term impact of safer choices: a multicomponent, school-based HIV, other STD, and pregnancy prevention program.

This study evaluated the effectiveness of the first year of Safer Choices, a theoretically based, multicomponent HIV, STD, and pregnancy prevention program for high school youth. The study featured a randomized trial involving 20 schools in California and Texas, with a cohort of 3,869 ninth-grade students. Students who completed both the baseline and the first follow-up survey approximately seven months later were included in the analysis (n = 3,677). Safer Choices enhanced 9 of 13 psychosocial variables including knowledge, self efficacy for condom use, normative beliefs and attitudes regarding condom use, perceived barriers to condom use, risk perceptions, and parent-child communication. Safer Choices also reduced selected risk behaviors. Specifically, Safer Choices reduced the frequency of intercourse without a condom in the three months prior to the survey, increased use of condoms at last intercourse, and increased use of selected contraceptives at last intercourse.

Adolescent↗
PubMed1999

The impact of condom availability [correction of distribution] in Seattle schools on sexual behavior and condom use.

OBJECTIVES: Ten Seattle high schools made condoms available through vending machines, baskets in school clinics, or both. This study measured the number of condoms that students obtained and subsequent changes in sexual behavior and condom use. METHODS: Schoolwide surveys were administered in spring 1993 and in spring 1995, before and during the condom availability program. These data were compared with data from nationally representative surveys administered at the same time. RESULTS: Seattle students obtained an average of 4.6 condoms per year, the vast majority from baskets and very few from vending machines. Relative to the national samples, the percentage of Seattle students who had ever had sex remained stable after the program began; current sexual activity decreased significantly; and the percentage of sexually experienced students who used a condom the last time they had sex decreased significantly, particularly in the 5 schools with baskets of condoms in clinics. CONCLUSIONS: Making condoms available in Seattle schools enabled students to obtain relatively large numbers of condoms but did not lead to increases in either sexual activity or condom use.

Adolescent↗
PubMed1997

The safer choices project: methodological issues in school-based health promotion intervention research.

Randomized trials of school-based health promotion programs present unique design and analytical issues not widely discussed in the research literature. This article describes the Safer Choices study--a school-based program for prevention of HIV, other sexually transmitted diseases, and pregnancy--to illustrate critical methodological issues involved in large-scale, school-based intervention trials, particularly those evaluating interventions with a school-wide focus. The issues presented are: 1) comparability of the intervention and control groups even when few units are randomized; 2) factors that affect the decision to use a cohort or cross-sectional design; and 3) appropriate analysis strategy when the unit of randomization and intervention is at the school level, but observations are at the student level.

Adolescent↗
PubMed1996

Recruitment and enrollment for Project HeartBeat! Achieving the goals of minority inclusion.

OBJECTIVE: The inclusion of women and minorities in health research supported by the National Institutes of Health (NIH) has received increasing attention since the adoption of related guidelines by NIH in 1990. Investigators in population-based and clinical research may need to identify and recruit research participants from community settings in which little is known by investigators of the dynamics and day-to-day needs of the community. This was the case at the start of Project HeartBeat!, an intensive longitudinal study of the development of cardiovascular risk factors against the background of growth and maturation. This paper identifies those elements found essential when recruiting and enrolling minority participants for Project HeartBeat! METHODS: No prior experience had existed in the community from which the majority of Black participants were recruited to the Project. Therefore, recruitment methods were based on previous experience of the investigators as well as on the published reports of others. RESULTS: Immediate costs were substantially greater than projected, and the recruitment period was two years rather than one-a circumstance with longer-term implications as well. However, with the support of a community-based advisory committee, the school district, and a local recruitment staff, the recruitment goal was obtained. CONCLUSIONS: Recruitment and enrollment of minority participants can be especially challenging; however, many of those challenges are common to any target population. Elements that need to be adequately addressed include the researchers' involvement with the community in which the participants live, a tracking system to assess recruitment efforts, flexibility in the methods of recruitment, and adequate resources in time, money and personnel.

Adolescent↗
PubMed1992

Screening for patients with alcohol problems: severity of patients identified by the CAGE.

Primary care physicians are well situated to identify patients with substance abuse problems and motivate them to seek appropriate assistance, but active programs are the exception. A study in a community setting was undertaken to assess the CAGE (the first letters of key words in a series of four questions about drinking: cut down; annoyed; guilty; and eye-opener), instrument in the routine screening for alcohol problems in both new and established patients. The screening process identified subjects for a pilot evaluation of a motivational interview designed to encourage problem-solving behavior. This article focuses on the screening results and the use of the CAGE instrument. During June and July of 1990, 687 patients of two primary care physicians belonging to a large group practice were asked to complete a health questionnaire that included the CAGE. Those who responded affirmatively to at least two of the four CAGE questions were requested to participate in follow-up assessment of problems associated with alcohol and health. The type and severity of alcohol problems experienced by patients who scored positive on the CAGE are described. Prevalence of a positive score on the CAGE was 8.6 percent with males, smokers, and blue collar and unemployed persons being more likely to score positive. The positive predictive value was .68. Primarily, persons with moderate alcohol problems were identified. Results show that the CAGE instrument is a useful screening device for identifying those with mild to moderate substance abuse problems, increasing the opportunity for intervention prior to serious medical complications. The instrument is easily administered, and has demonstrated relatively high levels of sensitivity and specificity. When combined with assessment and motivational interviews, the CAGE shows promise in the secondary prevention of substance abuse and related health problems.

Adult↗
PubMed1985

Cardiovascular alterations in severe pregnancy-induced hypertension: relationship of central venous pressure to pulmonary capillary wedge pressure.

The relationship between central venous pressure and pulmonary capillary wedge pressure was studied in 18 patients with severe pregnancy-induced hypertension. Although statistically a linear relationship for the group as a whole could be identified, analysis on a case-by-case basis revealed different results. In 10 patients, a linear correlation between central venous pressure and pulmonary capillary wedge pressure was observed. However, accurate prediction of pulmonary capillary wedge pressure from central venous pressure was not possible even in this group because of large interindividual variations. In seven patients no correlation between central venous pressure and pulmonary capillary wedge pressure could be identified. In the last patient a curvilinear relationship existed between central venous pressure and pulmonary capillary wedge pressure. Additionally, in five cases of pulmonary edema, a negative gradient of colloid osmotic pressure to pulmonary capillary wedge pressure gradient was observed. Our data suggest that central venous pressure is not a clinically reliable predictor of pulmonary capillary wedge pressure.

Central Venous Pressure↗
PubMed1983

Effect of propranolol on ventricular arrhythmia. The beta-blocker heart attack trial experience.

The Beta-Blocker Heart Attack Trial (BHAT) was a multicenter, randomized, double-blind, placebo-controlled trial that tested the effectiveness of propranolol in reducing the mortality rate in patients after myocardial infarction (MI). Twenty-four hour ambulatory ECG monitoring was done on 3279 of the 3837 enrolled patients at baseline (5-21 days after hospital admission) and repeated after 6 weeks of therapy in a random sample of 25% of the study population. Ventricular arrhythmias were divided into seven different categories and the prevalence of each category is presented. Ventricular arrhythmia at baseline appears to increase with patient age, past history of myocardial infarction, and use of diuretics. Other selected variables--sex, CPK ratio and history of smoking, diabetes and hypertension--appear to be less clearly associated with ventricular arrhythmia. Paired data analysis performed on 826 patients who had ambulatory electrocardiograms both at baseline and after 6 weeks of treatment showed an increased prevalence of ventricular arrhythmia at 6 weeks. This increase was blunted by propranolol therapy.

Adult↗
PubMed1982

Effects of methods of collection and storage on nutrients in human milk.

The effects of collection technique, storage container, and the duration and temperature of storage on selected nutrient concentrations in mature human milk were evaluated. Milk samples were collected during the fourth week of lactation from women 20-35 years of age by hand expression or suction. Greater volumes and fat concentrations were observed in milks collected by suction. Vitamin A, zinc, iron, copper, sodium, and protein nitrogen concentrations were not affected by storage of milk in either pyrex or polypropylene containers for up to 24 h. The storage temperature had a significant effect on protein nitrogen and ascorbic acid concentrations. These findings indicate that collection methods and storage procedures used for comparatively brief periods will affect the concentrations of selected nutrients of mature human milk. Specific recommendations are made for the collection and storage of milk.

Adult↗
PubMed1980

Intracellular concentration of elements in normal and dystrophic skeletal muscles of the chicken.

In this study, the intracellular concentrations of six elements (mmole/kg dry weight) were directly measured in the muscle fibers of pectoralis major muscles of eight week old, genetically dystrophic and normal chickens by the X-ray microanalysis technique. The extent of muscle degeneration was evaluated by morphometric measurements of muscle fiber diameter and other histological changes. A significant increase in the concentration of intracellular sodium and chlorine was evident in dystrophic muscles. The concentration of intracellular sodium was 127.0 +/- 35.0 in the muscle fibers of dystrophic chicks compared to 65.7 +/- 16.5 in normal controls. The concentration of chlorine was 90.5 +/- 27.5 and 54.1 +/- 5.5 in the muscle fibers of dystrophic and normal chicks respectively. The intracellular concentrations of potassium, magnesium, phosphorous, and sulfur remained unchanged in the dystrophic condition. Morphometric studies revealed that the dystrophic pectoralis muscles contain fewer but thicker fibers per unit area compared to normal pectoralis muscles. The importance of these findings are discussed in relation to the results of earlier investigations.

Animals↗
PubMedDate not supplied

Scapular reactivity to contact irritants: application-time and area variations.

Twenty-two diurnally active, fair-skinned, male volunteers were repeatedly patch tested with 10, 15 and 20% lapyrium chloride (LC) and 0.3 and 0.5% sodium lauryl sulfate (SLS) for 5 consecutive days. A series of 5 patches containing SLS and LC were placed vertically once daily for 6 h on different sites of the scapula: paravertebral, lateral and medial. The sites of application were randomized over subjects for patch testing once a day per area at either 08%, 16% or 00%. Each patch was left in place 6 h; scoring of each site, using a 13-point scale, was done 2, 10 and 18 h after removal. The cutaneous reactivity varied in a statistically significant manner according to the time and area of patch application. For each day except the first, LC scores exhibited highest and lowest responses at 16% and 00%, respectively. For SLS, a statistically significant application-time difference in reactivity was detected only for the readings of day 2 when scores were highest at 00% and lowest at 16%. Intraregional variations in scapular reactivity were also exhibited. Strongest reactions to LC occurred in the center of each scapula; weakest reactions were elicited on either the lateral or paravertebral sites. For SLS, statistically significant intraregional differences in reactivity were detected only for the second day of patching, with strongest responses near the spinal column and weakest near the axilla.

Adult↗