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Biomedical subjects

L Dean

Publications and source records attributed to L Dean.

At least 19 recordsLinked to original sources
PubMed1999

Maintaining health: proactive client-oriented community day treatment centres for the chronic mentally ill.

This grounded theory study compared the definition of health by clients of two rural mental health day treatment centres, Big Sky Centre and Montana Centre. Based on an original grounded theory study of seven chronic mentally ill/disabled clients in Big Sky Centre (Yurkovich et al. 1997), the core variable, 'preventing loss of control' and related properties, were validated with nine residents of Montana Centre. While establishing a 'fit' with previous research findings, differences emerged between these two centres. These differences related to the staffs' philosophical approaches in providing treatment to the chronic mentally ill. Big Sky Centre care providers empowered their clients to learn new behaviours from their peers and assume new roles such as newcomer, member and leader. They also encouraged a prosocial attitude, and created a sense of belonging through valued involvement in their treatment. Montana Centre clients were not empowered to try out new behaviours in the treatment environment, or seek social support networks among their peers at the centre, which would foster a sense of belonging. The result was that clients from Montana Centre relied on the formal healthcare system more often than clients from the Big Sky Centre. The competing forces in healthcare today--family members, mental health providers, and insurance or managed care providers--make it easy to lose sight of or fail to gain the client's perspective about their health status and maintenance, particularly as it concerns day treatment centres. The importance of the day treatment centre as a therapeutic community which requires educational processes, innovative nursing practice, and client-centred interventions will be discussed.

Adult↗
PubMed1999

Symptom interpretation: implications for delay in HIV testing and care among HIV-infected late middle-aged and older adults.

Physical symptoms and the attributions assigned to them are fundamental aspects of individuals' illness representations and influence health behaviours. The effects of the presence or absence of symptoms and the interpretation of these symptoms on the initiation of HIV testing and medical care are explored using data from a psychosocial study of HIV illness in late middle-aged and older men and women. The absence of symptoms negatively influenced willingness both to seek testing and to seek medical care. While the presence of symptoms would be expected to lead to testing and the initiation of medical care, the effect of symptoms was dependent on causal interpretations of the symptoms. Symptoms attributed (or misattributed) to other illnesses or to normal aging did not lead to initiation of testing or care. These results appear to be due to people's lay belief that illness must include symptoms and due to a resistance against accepting an illness identity. This research suggests that HIV education and counselling should emphasize the need for individuals at risk for HIV to seek testing and medical care even if symptoms of the disease are absent.

Acquired Immunodeficiency Syndrome↗
PubMed1998

Better outcome for women compared with men undergoing coronary revascularization: a report from the bypass angioplasty revascularization investigation (BARI)

BACKGROUND: Numerous studies have shown that women undergoing coronary revascularization procedures do so at a higher risk for an adverse outcome compared with men. However, the impact of advances in technology and improvements in techniques on in-hospital and long-term outcome after revascularization in women is unclear. METHODS AND RESULTS: We evaluated 1829 patients with symptomatic multivessel coronary disease randomized to CABG or PTCA in the Bypass Angioplasty Revascularization Investigation (BARI), of whom 27% were women. As expected, women were older (64.0 versus 60.5 years), with more congestive heart failure (14% versus 7%), hypertension (68% versus 42%), treated diabetes mellitus (31% versus 15%), and unstable angina (67% versus 61%) than men but had similar preservation of left ventricular function and extent of multivessel disease. Women assigned to surgery received the same number of total grafts but fewer internal mammary artery grafts (72% versus 85%, P<0. 01), and those assigned to angioplasty had more intended lesions (76% versus 71%, P<0.01) successfully dilated than men. At an average of 5.4 years' follow-up, crude mortality rates were similar in women (12.8%) and men (12.0%). The Cox regression model adjusting for baseline differences revealed that women had a significantly lower risk of death (relative risk, 0.60; 95% CI, 0.43 to 0.84; P=0. 003) but not a significantly lower risk of death plus myocardial infarction (relative risk, 0.84; 95% CI, 0.66 to 1.07; P=0.16) than men. CONCLUSIONS: Although the unadjusted mortality rate suggests that women and men undergoing CABG and PTCA have a similar 5-year mortality, women have higher risk profiles; consequently, contrary to previous reports, female sex is an independent predictor of improved 5-year survival after we control for multiple risk factors.

Aged↗
PubMed1995

HIV prevalence and sexual behavior in a cohort of New York City gay men (aged 18-24).

An ethnically diverse cohort (n = 174) of New York City gay men (aged 18-24) was studied to determine human immunodeficiency virus (HIV) prevalence and to document sexual behavior patterns. Blood tests of 87 men showed an HIV prevalence of 9%, but only 3% of the previously tested men (n = 77) reported knowledge of a positive test result at baseline interview. An annual HIV seroconversion rate of 2% was observed. Ethnic minority men were more likely to test HIV positive. In addition, the median number of both sexual episodes and sex partners, and the proportion of men who engaged in anal intercourse, increased significantly from 1990 to 1991. During this 2-year period, 91% of the men engaged in unprotected receptive oral intercourse, and 37% engaged in unprotected receptive anal intercourse.

Adult↗
PubMed1995

Bacillaene, a novel inhibitor of procaryotic protein synthesis produced by Bacillus subtilis: production, taxonomy, isolation, physico-chemical characterization and biological activity.

Bacillaene, a novel polyene antibiotic, was discovered and isolated from fermentation broths of a strain of Bacillus subtilis. The novel antibiotic has a nominal molecular weight of 580 and an empirical formula of C35H48O7. Bacillaene is active against a broad spectrum of bacteria in agar-plate diffusion assays. Studies in vitro indicate that the antibiotic inhibits prokaryotic protein synthesis but not eukaryotic protein synthesis. Cell survival studies performed with strains of Escherichia coli indicate that the antibiotic is a bacteriostatic agent.

Anti-Bacterial Agents↗
PubMed1995

Patterns of sexual behavior and risk taking among young New York City gay men.

One-hundred and seventy-four young New York City gay men (aged 18-24) were studied over a two-year period. We describe patterns of HIV risk taking behavior and factors that predict risk taking. Among men who engaged in receptive anal intercourse we discerned different patterns of behaviors. We defined risk takers as men who engaged in receptive anal intercourse. About two-thirds of the men fall into this category in each year, and about half of those (one third of the total) engaged in unprotected anal intercourse. Most of these men seem to make implicit decisions in managing their risk for HIV. Men who engaged in receptive anal intercourse were more likely to be in a coupled relationship and to know their partners' HIV status. Alcohol and/or drug use during sex, earlier sexual experiences, and greater integration into the gay community were also related to receptive anal intercourse. By contrast, a significant minority of the men, about 6% of the sample, engaged in very high risk behavior in each year of the study-defined as unprotected receptive anal intercourse with multiple partners. It appears that very high risk takers are qualitatively different from other risk takers: They reported more mental health problems, including more drug use, and higher levels of internalized homophobia and AIDS-related traumatic stress response. Implications for AIDS education and prevention are discussed.

Acquired Immunodeficiency Syndrome↗
PubMed1995

Social and sexual networks: their role in the spread of HIV/AIDS among young gay men.

This article examines how networks of social and sexual relations affect risky sexual behavior and HIV seroprevalence among young gay men. Social networks can transmit information and cultural norms regarding safer sex, while networks of sexual partners channel the risk of exposure to HIV infection. These two network effects may help to explain some of the behavior and seroconversion differentials in the gay community. A number of recent studies have shown higher rates of unsafe sex among younger gay men. In the Longitudinal AIDS Impact Project, for example, younger gay men (18-24) report unsafe receptive anal sex at rates double that for any other age group (30% vs. 14-16%). One possible explanation is that younger men have watched fewer friends and colleagues contract HIV or AIDS, and are correspondingly less cautious. We test this hypothesis by comparing the personal networks of younger and older gay men to see whether those who practice safer sex have more exposure to persons with HIV or AIDS. The results give only weak support for the hypothesis that personal exposure to the effects of HIV and AIDS increases adherence to safer sex practices. Seroprevalence patterns among young men may be the result of their sexual networks, with those choosing older partners more likely to be exposed to HIV infection. We examine this hypothesis by comparing the age composition of the unsafe sexual partner network for seropositive and seronegative young men. The results strongly support the hypothesis that younger gay men with older partners are the leading edge of the epidemic in their cohort.

Acquired Immunodeficiency Syndrome↗
PubMed1995

Effects of AIDS-related bereavement on HIV progression among New York City gay men.

This study investigates the relationship between early AIDS-related bereavement and subsequent changes in CD4 T-cell levels and health over a three- to four-year follow-up period in 85 HIV positive gay men. In addition, two psychological responses to loss, grief, and depression were distinguished and used as predictors of changes in health following loss. Interview data collected each year was used to assess psychological, behavioral and health factors. Blood samples drawn yearly were used to assess CD4 T-cell levels. Results indicate that those who had experienced an AIDS-related bereavement event prior to entry into the study showed a more rapid loss of CD4 T-cells over time, controlling for age, initial health status, use of antiretrovirals, sedatives, recreational drugs, cigarettes, and alcohol as well as other potential confounding factors. CD4 loss-rate differences were observable by two years post-bereavement. In addition, grief reactions were distinguishable from depressive reactions. Grief reactions were unrelated to CD4 decline and symptom onset while aspects of depression, specifically self-reproach, were predictive of CD4 loss. These data suggest that bereavement may impact biological systems relevant to HIV progression and that distinguishing specific responses to loss may improve our understanding of these relationships.

Acquired Immunodeficiency Syndrome↗
PubMed1994

Effect of sexual behavior change on long-term human immunodeficiency virus prevalence among homosexual men.

Substantial changes in human immunodeficiency virus (HIV)-related sexual behavior have been reported by virtually every survey of homosexual/bisexual men in the last decade. This paper uses a behavior-based simulation to examine how such changes are likely to affect the long-term future of the acquired immunodeficiency syndrome (AIDS) epidemic among homosexual men. Data from the Longitudinal AIDS Impact Project in New York City are used to estimate age-specific patterns of unprotected anogenital contact and behavioral change from 1980 to 1991. Model projections are validated using New York City surveillance data on AIDS incidence from 1981 to 1991. The current levels of unsafe sex reported in the Longitudinal AIDS Impact Project are shown to be almost exactly on the epidemic threshold. If this behavior were maintained, HIV prevalence would slowly decline in the population, but with just one additional unsafe sexual partner per year HIV would instead become endemic, with seroprevalence of about 65% in the oldest group and about 25% in the youngest. Transmission dynamics in the youngest group are analyzed in detail. For this group, the assortative age-matching bias in partner selection patterns raises the unsafe behavior threshold slightly in the long run.

Acquired Immunodeficiency Syndrome↗
PubMed1993

Effects of AIDS-related bereavement and HIV-related illness on psychological distress among gay men: a 7-year longitudinal study, 1985-1991.

In this study we examined the influence of acquired immunodeficiency syndrome (AIDS)-related bereavement on psychological distress from 1985 through 1991. We predicted that this relation would be influenced by personal knowledge of human immunodeficiency virus (HIV) infection and symptoms consistent with HIV-related illness. Interview data collected each year on a cohort of 746 gay men included information on the deaths and illnesses of network members caused by AIDS, as well as on psychological distress, sedative use, HIV-related symptoms, and HIV infection status. Significant main effects of bereavement were found in each year after controlling for both losses occurring from 1 to 2 years previously and for AIDS and HIV health status. The intensity and duration of these bereavement effects diminished over time. Groups of men who were both bereaved and classified as having AIDS or were HIV positive reported the highest level of distress in every year compared with the 3 other groups.

Acquired Immunodeficiency Syndrome↗
PubMed1992

10'-Desmethoxystreptonigrin, a novel analog of streptonigrin.

10'-Desmethoxystreptonigrin, a novel analog of streptonigrin produced by Streptomyces albus, was discovered in a screen for inhibitors of farnesylation of RAS p21 protein. The compound was isolated from the fermentation broth and its structure determined. It is markedly cytotoxic to several human tumor cell lines and also exhibits potent broad-spectrum antibacterial activity.

Animals↗
PubMed1990

The influence of social support on AIDS-related grief reaction among gay men.

This paper examines the relationships between instrumental and emotional social support and the experience of grief reaction in a sample of 180 gay men who had lost a lover or close friend to AIDS during the first 5 years of the epidemic. Structured, face-to-face interviews were conducted in mid-1985. Grief reaction was assessed through a newly developed 12-item scale (alpha = 0.85). Availability and adequacy of instrumental and emotional support were assessed with reference to the tasks of caretaking and emotional pain experienced during the lover's or close friend's illness with AIDS. The findings indicate that gay men who lost a lover or close friend to AIDS experienced symptoms of grief similar to those reported in studies of bereaved spouses and parents. The intensity of these grief reactions appears to be influenced by a number of factors. First, more intense grief reactions were observed among those who had taken care of their lover or close friend during his illness compared with those who did not act as caretakers. Second, while the simple availability of instrumental and emotional support was unrelated to grief reactions, the perceived adequacy of both types of support was strongly related to the level of grief. Respondents who had received inadequate help with caretaking responsibilities experienced more intense symptoms of grief subsequent to the death compared with those who reported receiving adequate caretaking support. Similarly, respondents who did not obtain adequate emotional support for the pain they experienced during the course of the illness reported more intense symptoms of grief compared with those who felt they had received adequate support.(ABSTRACT TRUNCATED AT 250 WORDS)

Acquired Immunodeficiency Syndrome↗
PubMed1990

Left ventricular volume measurement using cardiac axis nuclear magnetic resonance imaging. Validation by calibrated ventricular angiography.

Proton nuclear magnetic resonance (NMR) imaging has the potential to serially assess left ventricular (LV) volumes with optimal accuracy because it is a high-resolution, three-dimensional, noninvasive modality. Previous NMR studies to assess LV volumes have been suboptimal, as they have used either planes aligned with the axes of the body, which are compromised by partial volume effects, or spin-echo techniques that have been time-consuming to acquire and analyze. Accordingly, for LV volume measurement, we developed a gradient-echo (cine) NMR strategy that uses two orthogonal planes intersecting along the intrinsic long axis of the heart (two-chamber and four-chamber). This approach was validated against calibrated contrast biplane LV cineangiography (CATH) and also compared with a previously reported short-axis spin-echo NMR method. Twenty-one patients underwent CATH and NMR (long-axis, n = 21; short-axis, n = 14) within a 3-day interval. Although both long- and short-axis NMR LV volumes and ejection fractions correlated well with CATH (r greater than 0.90, p less than 0.001 in all), end-diastolic volumes by both long-axis (161 +/- 85 ml) and short-axis (151 +/- 81 ml) NMR were systematically less than those by CATH (182 +/- 85 ml) (p less than 0.05). Consequently, ejection fractions by long-axis (48 +/- 17%) and short-axis (49 +/- 17%) NMR consistently underestimated those by CATH (54 +/- 16%, p less than 0.05). End-systolic volumes by long-axis (94 +/- 71 ml) and short-axis (87 +/- 72 ml) NMR were not significantly different from those by CATH (92 +/- 69 ml). Both NMR techniques had low intraobserver and interobserver variation (less than 11%); however, short-axis spin-echo NMR involved longer acquisition/reconstruction (35 versus 18 minutes) and analysis (25 versus 10 minutes) times. We conclude that both short-axis spin-echo and long-axis gradient-echo NMR approaches reliably estimate LV volumes. Currently, the long-axis strategy appears more practical for clinical use because the scan and analysis times are relatively short.

Adult↗
PubMed1990

Janthinocins A, B and C, novel peptide lactone antibiotics produced by Janthinobacterium lividum. I. Taxonomy, fermentation, isolation, physico-chemical and biological characterization.

Janthinocins A, B and C are novel antibacterial agents produced by Janthinobacterium lividum. They were isolated from fermentation broths and characterized by UV, IR, NMR and mass spectroscopy. They are cyclic decapeptide lactones with marked activity against aerobic and anaerobic Gram-positive bacteria and are 2 to 4 times more potent in vitro than vancomycin. Janthinocins A and B were also found to be effective in a Staphylococcus aureus systemic infection in mice.

Animals↗
PubMed1989

A worksite smoking cessation intervention involving the media and incentives.

This study evaluated an attempt at 38 workplaces to help employees stop or reduce their levels of smoking. In past research, worksite support groups, in combination with a media smoking cessation program and self-help manuals, were found to be effective in helping employees quit smoking. Unfortunately, recidivism was found at the follow-up evaluations. The present study replicated the results of the previous worksite smoking cessation program with support groups, a television intervention, and self-help manuals. At this postpoint, 42% of employees provided groups plus incentives were abstinent compared to only 15% who were only provided self-help materials. An important difference in this study was that there were also monthly follow-up support groups and incentives. Work settings can be a source of stress and conflict, which can precipitate relapse. At a 12-month follow-up, 26% of those participants who were provided support and incentives were abstinent compared to 16% who were only provided the self-help materials.

Adult↗