PubMed Health⌕ Search

Biomedical subjects

N Lovell

Publications and source records attributed to N Lovell.

4 recordsLinked to original sources

Associations of sociodemographic, psychosocial, and behavioral factors with sexual risk and sexually transmitted diseases in teen clinic patients.

PURPOSE: To examine the influence of sociodemographic characteristics, sexually transmitted disease (STD)/human immunodeficiency virus knowledge, and psychosocial and behavioral risk factors on sexual risk and STDs in adolescents using constructs from the Information, Motivation, and Behavioral Skills model (IMB). METHODS: A convenience sample of 303 sexually experienced, racially diverse adolescents (mean age 16.7 years, 57.9% female) who were seeking health care at a general health maintenance organization teen clinic were recruited for the study and completed a self-reported questionnaire which assessed sociodemographic, knowledge, and psychosocial factors, risk behaviors, and history of STDs. Multiple regression analyses were used to assess factors associated with sexual risk behavior and STD history. RESULTS: Many of the study participants were at risk for STDs; 43.8% had four or more lifetime sexual partners, 62.8% did not consistently use condoms, 21.1% had a history of pregnancy or impregnation, and 28.2% had a history of STDs. A multiple linear regression model to assess factors associated with sexual risk behavior (a nine-item index) indicate that perceptions of higher STD risk, perceptions that friends engage in risk behaviors, perceptions that friends will not support their STD risk-reduction efforts, knowing someone of a similar age who has had an STD, and having no intention of using condoms in the future are significantly associated with sexual behavioral risk (R(2) =.22, p <.000). A logistic regression model to examine history of STDs reveals that teens who are female, African-American, frequently use marijuana, have an older steady sexual partner, have a history of pregnancy or impregnation, have a greater number of lifetime sexual partners, and perceive that monogamy will not decrease STD risk are significantly more likely to report a history of STDs. CONCLUSIONS: Sociodemographic factors and constructs of the IMB model are associated with adolescents' risk and acquisition of STDs. Teens with such risk profiles should be targeted for risk-reduction intervention.

Adolescent↗

Research and clinical assessment of eating and exercise behaviour.

The Eating and Exercise Examination (EEE-C) is an efficient, self-report, computer-generated and computer-reported examination of eating and exercise behaviour, attitudes and feelings. It is clinically useful for assessment of eating and exercise disorders, as a therapeutic tool to provide feedback to patients and as an instrument to provide standardized data for cost effective and relapse prevention studies.

Body Image↗

Ion currents underlying sinoatrial node pacemaker activity: a new single cell mathematical model.

The ionic currents underlying autorhythmicity of the mammalian sinoatrial node and their wider contribution to each phase of the action potential have been investigated in this study using a new single cell mathematical model. The new model provides a review and update of existing formulations of sinoatrial node membrane currents, derived from a wide range of electrophysiological data available in the literature. Simulations of spontaneous activity suggest that the dominant mechanism underlying pacemaker depolarisation is the inward background Na+ current, ib,Na. In contrast to previous models, the decay of the delayed rectifying K+ current, iK, was insignificant during this phase. Despite the presence of a pseudo-outward background current throughout the pacemaker range of potentials (Na-K pump+leak currents), the hyperpolarisation-activated current i(f) was not essential to pacemaker activity. A closer inspection of the current-voltage characteristics of the model revealed that the "instantaneous" time-independent current was inward for holding potentials in the pacemaker range, which rapidly became outward within 2 ms due to the inactivation of the L-type Ca2+ current, iCa,L. This suggests that reports in the literature in which the net background current is outward throughout the pacemaker range of potentials may be exaggerated. The magnitudes of the action potential overshoot and the maximum diastolic potential were determined largely by the reversal potentials of iCa,L and iK respectively. The action potential was sustained by the incomplete deactivation of iCa,L and the Na-Ca exchanger, iNaCa. Despite the incorporation of "square-root" activation by [K]o of all K+ currents, the model was unable to correctly simulate the response to elevated [K]o.

Action Potentials↗