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Biomedical subjects

A Prokhorov

Publications and source records attributed to A Prokhorov.

9 recordsLinked to original sources
PubMed2002

In vivo impedance measurements on nerves and surrounding skeletal muscles in rats and human body.

The aim of the work was to use impedance measurements to find the location of nerves under the human skin. In vivo impedance measurements were performed on exposed nervous and muscular tissues of rats. Similarly, the impedance measurements were also performed on the skin of six men, over the median nerve at the wrist, as well as 4-5 mm away from this location. Results obtained with rats have shown that the relative permittivity and conductivity of nerves are larger (by almost two orders of magnitude) than those observed for the muscular tissues surrounding the nerve. The results obtained on human skin in the frequency range of 20-200 kHz, when the electrodes were placed over the nerve, show lower resistance and higher capacitance than in the other areas measured. These preliminary results indicate that it may be possible to use impedance measurements to find the location of exposed nerves and also nerves under the skin.

Adult↗
PubMed2001

Depression and substance use in minority middle-school students.

OBJECTIVES: This study investigated the association between depression and substance use in a sample of middle-school students. METHODS: The 5721 students (59%-63% Hispanic) completed self-report items on depressive symptoms, recent smoking and binge drinking, and lifetime use of marijuana, cocaine, and inhalants. RESULTS: Symptoms of depression were strongly and positively related to substance use. For every type of use, a stepwise increase was seen between the percentage of students with low symptom frequency and the percentage of students with more symptoms. A sizable number of users reported symptoms indicating major depression. Depression scores showed few clinically meaningful differences among demographic subgroups. Substance use scores, in contrast, showed meaningful intergroup differences for racial/ethnic group and other demographic variables. CONCLUSIONS: Depressive symptoms and substance use were associated in a sample of middle-school students who were largely non-White and predominantly Hispanic. Greater understanding of the nature of this association is needed; this understanding should be used to design prevention programs, and prevention programs should be introduced at least in the middle-school years.

Achievement↗
PubMed1999

Gender differences in chronic disease risk behaviors through the transition out of high school.

BACKGROUND: Major life transitions (e.g., graduation from high school) are times when many changes occur in a person's social and physical environment. Men and women likely experience aspects of these changes differently. As a result, health-related behaviors likely change at these times with possible differences in these changes by gender. METHODS: Gender differences in the performance of chronic disease risk-related behaviors (fruit, juice, and vegetable intake; physical activity; tobacco and alcohol use; and sexual practices) through the transition out of high school (HS) were assessed in a secondary analysis of a nationally representative sample from the 1992 National Health Interview Survey-Youth Risk Behavior Survey. The survey was completed by 5881 young people aged 14 to 21 years. Regression discontinuity analysis with piecewise regression was performed. RESULTS: Statistically significant gender by transition effects were obtained for exercise/physical activity (decreases at the transition point for males), snuff use (decrease for females in HS), binge drinking and number of days drinking alcohol (increases for males at the transition point), and use of alcohol or drugs before sexual intercourse (decrease for females post HS). Fruit intake decreased for males and females and daily and heavy cigarette smoking increased during the HS years. Effect sizes were small but promising, given that the data set was not designed to test this hypothesis. CONCLUSION: These data offer evidence of differences by gender in chronic disease risk behaviors through the HS transition. Longitudinal studies are needed to assess the true nature of these differences, the tracking of these risk behaviors and their personal, social, and environmental determinants, including gender-specific determinants, that may explain these changes and inform future intervention development.

Adolescent↗
PubMed1999

Ethnic differences in cancer risk behaviors through the transition out of high school.

Differences were assessed by ethnic group in the performance of cancer risk related lifestyle behaviors through the transition out of high school. Data were obtained from a nationally representative probability sample survey, the 1992 National Health Interview Survey-Youth Risk Behavior Survey. A cross-sectional sub-sample included adolescents with an age range from high school freshmen to young adults within four years after high school. Self reported indicators of diet, physical activity, cigarette smoking, smokeless tobacco use, alcohol use, and sexual practices were the primary dependent measures. Cancer risk increased at the transition out of high school through changes in cancer related behaviors. Hispanic-American males experienced somewhat higher risks after the transition for chewing tobacco and snuff. African Americans experienced somewhat higher risks after the transition for physical activity, chewing tobacco, and number of sexual partners. Further research needs to verify these findings with longitudinal designs, assessment of tracking of behaviors through the transition, and of the ecological, social and psychosocial correlates that may explain why these changes occurred.

Adolescent↗
PubMed1996

Current approaches in smoking cessation.

This review highlights the necessity of smoking cessation as a cornerstone of cancer prevention. We briefly review the literature linking smoking to various forms of cancer, the benefits of smoking cessation for cancer patients, and the Agency for Health Care Policy and Research Smoking Cessation Clinical Practice Guideline. Also provided is an update on controlled smoking cessation studies published between March 1995 and February 1996.

Antidepressive Agents↗
PubMed1988

Prevention of atherosclerosis among 11-year-old schoolchildren in two Moscow administrative districts.

A total of 4,213 boys and girls 11 years of age were screened in two Moscow administrative districts. Preventive measures were conducted in one district and were directed at excess body mass, systolic blood pressure, blood lipids (only among boys), cigarette smoking, and physical inactivity. A reference group of peers, who did not receive advice on prevention, was selected from another district. The intervention was targeted to three groups--schoolchildren, their parents, and teaching staff. It included round-table discussions, lectures, and the distribution of health-education materials relating to dietary habits and smoking. Over a 3-year period, these measures resulted in nonsignificant decline in the age-specific increase in body mass compared to the reference group. The intervention group had smaller subscapular skinfold thickness measurements than the reference group. These differences were significant. Mean systolic blood pressure increased with age in both groups. The increase was less in the intervention group than in the reference group and affected boys less than girls. A significant decrease in lipids (cholesterol and triglycerides) was observed in the intervention district. We conclude that additional study is needed to evaluate more precisely the effectiveness of such prevention efforts.

Arteriosclerosis↗
PubMedDate not supplied

A population-based survey of physician smoking cessation counseling practices.

BACKGROUND: To be most effective, physicians' smoking cessation interventions must go beyond advice, to include counseling and follow-up. A full profile of physician performance on the recommended activities to promote smoking cessation has not been provided previously. METHODS: We surveyed a representative sample of 246 community-based primary care physicians who had agreed to participate in a 3-year study to evaluate a strategy for disseminating smoking cessation interventions, based on the National Cancer Institute 4-A model and on the Transtheoretical Model of Change. RESULTS: A majority reported they Ask (67%) and Advise (74%) their patients about smoking, while few go beyond to Assist (35%) or Arrange follow-up (8%) with patients who smoke. The criteria for "thorough" counseling was met by only 27% of physicians. More than half were not intending to increase counseling activity in the next 6 months. After controlling for other variables, physicians in private offices were more likely than physicians in HMO or other settings to be active with smoking cessation counseling. General Internal Medicine physicians were most active, and Ob/Gyn physicians were least active, with smoking cessation counseling among primary care specialty groups. CONCLUSIONS: Innovative approaches are needed to motivate, support, and reward physicians to counsel their patients who smoke, especially when considering the movement toward managed health care. PRECIS: A survey of primary care physicians focusing on national guidelines for smoking cessation counseling showed a majority Ask (67%) and Advise (74%) patients about smoking, but few Assist (35%) or Arrange follow-up (8%).

Adult↗