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Biomedical subjects

David Moore

Publications and source records attributed to David Moore.

At least 19 recordsLinked to original sources

Aboriginal status is a prognostic factor for mortality among antiretroviral naïve HIV-positive individuals first initiating HAART.

BACKGROUND: Although the impact of Aboriginal status on HIV incidence, HIV disease progression, and access to treatment has been investigated previously, little is known about the relationship between Aboriginal ethnicity and outcomes associated with highly active antiretroviral therapy (HAART). We undertook the present analysis to determine if Aboriginal and non-Aboriginal persons respond differently to HAART by measuring HIV plasma viral load response, CD4 cell response and time to all-cause mortality. METHODS: A population-based analysis of a cohort of antiretroviral therapy naïve HIV-positive Aboriginal men and women 18 years or older in British Columbia, Canada. Participants were antiretroviral therapy naïve, initiated triple combination therapy between August 1, 1996 and September 30, 1999. Participants had to complete a baseline questionnaire as well as have at least two follow-up CD4 and HIV plasma viral load measures. The primary endpoints were CD4 and HIV plasma viral load response and all cause mortality. Cox proportional hazards models were used to determine the association between Aboriginal status and CD4 cell response, HIV plasma viral load response and all-cause mortality while controlling for several confounder variables. RESULTS: A total of 622 participants met the study criteria. Aboriginal status was significantly associated with no AIDS diagnosis at baseline (p = 0.0296), having protease inhibitor in the first therapy (p = 0.0209), lower baseline HIV plasma viral load (p < 0.001), less experienced HIV physicians (P = 0.0133), history of IDU (p < 0.001), not completing high school (p = 0.0046), and an income of less than $10,000 per year (p = 0.0115). Cox proportional hazards models controlling for clinical characteristics found that Aboriginal status had an increased hazard of mortality (HR = 3.12, 95% CI: 1.77-5.48) but did not with HIV plasma viral load response (HR = 1.15, 95% CI: 0.89-1.48) or CD4 cell response (HR = 0.95, 95% CI: 0.73-1.23). CONCLUSION: Our study demonstrates that HIV-infected Aboriginal persons accessing HAART had similar HIV treatment response as non-Aboriginal persons but have a shorter survival. This study highlights the need for continued research on medical interventions and behavioural changes among HIV-infected Aboriginal and other marginalized populations.

Journal Article↗

Impact of baseline viral load and adherence on survival of HIV-infected adults with baseline CD4 cell counts > or = 200 cells/microl.

BACKGROUND: Baseline plasma HIV RNA levels > 100 000 copies/ml have been associated with elevated mortality rates after the initiation of HAART. There is uncertainty regarding the optimal strategy for patients with high plasma HIV RNA but CD4 cell count > or = 200 cells/microl. OBJECTIVE: To evaluate the impact of baseline plasma HIV RNA on survival among patients with CD4 cell counts > or = 200 cells/microl. METHODS: Patients were stratified by plasma HIV RNA, CD4 cell count and adherence level. Mortality rates were evaluated using Kaplan-Meier methods and Cox regression. RESULTS: Among 1166 patients initiating HAART with a CD4 cell count > or = 200 cells/microl, a baseline HIV RNA > or = 100 000 copies/ml was statistically associated with elevated mortality among non-adherent patients (log-rank P = 0.032), but not for adherent patients (log-rank P = 0.690). In a multivariate Cox model comparing patients with a baseline CD4 cell count > or = 200 cells/microl and a baseline plasma HIV RNA < 100 000 copies/ml, the mortality rate was statistically similar among patients with a baseline CD4 cell count > or = 200 cells/microl and a baseline plasma HIV RNA > or = 100 000 copies/ml (relative hazard, 1.21; 95% confidence interval, 0.89-1.65; P = 0.232). CONCLUSION: HIV RNA > or = 100 000 copies/ml was only associated with mortality among HIV-infected patients initiating HAART with CD4 cell counts > or= 200 cells/microl if the patients were non-adherent.

Adolescent↗

When is a little knowledge dangerous? Circumstances of recent heroin overdose and links to knowledge of overdose risk factors.

OBJECTIVES: To describe the circumstances surrounding recent heroin overdose among a sample of heroin overdose survivors and the links to their knowledge of overdose risk. METHODS: A cross-sectional survey of 257 recent non-fatal heroin overdose survivors was undertaken to examine self-reported knowledge of overdose risk reduction strategies, behaviour in the 12 h prior to overdose and attributions of overdose causation. RESULTS: Most of the overdoses occurred in public spaces as a result of heroin use within 5 min of purchasing the drug. A substantial number of overdoses occurred with no one else present and/or involved the concomitant use of other drugs. While knowledge of at least one overdose prevention strategy was reported by 90% of the sample, less then half of the sample knew any single strategy. Furthermore knowledge of the dangers of mixing benzodiazepines and/or alcohol with heroin was associated with an increased likelihood of such mixing being reported prior to overdose. CONCLUSIONS: While heroin users can articulate knowledge of key overdose risk reduction strategies, this knowledge was not generally associated with a reduction in risk behaviours but was in some cases associated with increased reports of overdose risk behaviours. Further research is required in order to better understand this paradoxical effect, focussing on risk reduction education amenable to the social contexts in which heroin use takes place.

Adolescent↗

A comprehensive comparative analysis of the occurrence of developmental sequences in fungal, plant and animal genomes.

We report a fully comprehensive data-mining exercise, involving an estimated total of 590,000 similarity searches, using agents available on the Internet to search for homologies to polypeptide sequences assigned to the category 'development' in the Gene Ontology Consortium AmiGO database (www.godatabase.org). The results indicate that of 552 such developmental sequences only 78 are shared between all three kingdoms, 72 are shared only between fungi and animals, 58 sequences are shared between plants and fungi, and four sequences were common only to Dictyostelium and fungi. No sequences were strictly fungus specific, but 68 occurred only in plants (Viridiplantae) and 239 occurred only in animals (Metazoa). Although some homology was indicated for a total of 219 fungal sequences, 143 (65%) of the matches returned were assigned E-values of 0.05 and must be categorised as weak similarities at best. The majority of the highly similar matches found in this survey proved to be between sequences involved in basic cell metabolism or essential eukaryotic cell processes (enzymes in common metabolic pathways, transcription regulators, binding proteins, receptors and membrane proteins). What is lacking is cross-kingdom similarity in the management processes that regulate multicellular development. The crown group of eukaryotic kingdoms control and regulate their developmental processes in very different ways. Unfortunately, we know nothing about molecular control of multicellular fungal developmental biology.

Amino Acid Sequence↗

Putting at risk what we know: reflecting on the drug-using subject in harm reduction and its political implications.

This paper provides a poststructuralist analysis of the cultural inscription of drug-using subjects in the neo-liberal discourses of contemporary harm reduction. We argue that although neo-liberal discourses downplay material constraints on individual human agency, divert policy and practice away from structural issues, limit the conception of effective strategies for harm reduction and ignore alternative formulations of the subject, they are also potentially empowering for drug users. Approximating the neo-liberal subject offers political benefits in terms of recognition, trust and legitimation, even as those values assume and reproduce understandings of behaviour, thought and sociality that fit only poorly the realities faced by many drug users. We explore this dilemma and consider three available directions in formulating the subject of harm reduction: (1) embracing the neo-liberal subject; (2) employing a more contextualised version of the neo-liberal subject; and (3) adopting alternative notions of subjectivity, extending the critique of the neo-liberal subject to all citizens, not solely drug users. To clarify some of these issues surrounding this strategic process, the paper considers another field in which struggles over the nature of the subject have been conducted--feminism. The intention is not to resolve the question of the most appropriate subject for harm reduction, but to sketch the political consequences of adopting particular models of the subject as a stimulus to further discussion and debate.

Culture↗

Engagement, reciprocity and advocacy: ethical harm reduction practice in research with injecting drug users.

In this paper, we contribute to the ethical challenges of harm reduction-based research by describing and reflecting on our experiences of initiating and maintaining relationships with research participants during an innovative neighbourhood-based study of the social and molecular epidemiology of the hepatitis C virus among injecting drug users over a 2-year period. We show through examples of our work how recruitment to our study had practical value for both researchers and study participants including advocacy and reciprocity. We argue that the recruitment process needed to be flexible, able to cope with the demands of the street drug market, and that we as researchers need to engage participants in their own environments as much as possible. We conclude with a series of recommendations for other researchers such as the need to employ appropriately skilled researchers who are flexible, innovative and comfortable in street settings, and for the setting of realistic time-frames for preliminary research, data collection and feedback and analysis.

Biomedical Research↗

Correlates of self-rated successful aging among community-dwelling older adults.

OBJECTIVE: There is no consensus on how to define successful aging. The authors sought to determine the correlates of self-rated successful aging as well as its correspondence with major researcher-defined criteria. METHODS: Participants were 205 community-dwelling adults over age 60. A questionnaire survey asked the participants to rate their own degree of successful aging and inquired about demographic characteristics, medical history, activity levels, resilience, daily functioning, and health-related quality of life (Medical Outcomes study 36-item Short-Form [MOS-SF-36]). Participants' subjective ratings of successful aging were contrasted with sets of researcher-defined criteria, and correlates of subjectively rated successful aging were examined. RESULTS: Ninety-two percent of the participants rated themselves as aging successfully. A majority of them also met other research criteria for successful aging such as independent living, mastery/growth, and positive adaptation but not those requiring an absence of chronic medical illness or physical disability. Higher SF-36 scores as compared with a published sample indirectly corroborated participants' subjectively rated successful aging. Subjective ratings of successful aging were significantly correlated with higher scores on health-related quality of life as well as resilience, greater activity, and number of close friends but not with several demographic characteristics. CONCLUSION: Most community-dwelling older adults viewed themselves as aging successfully despite having chronic physical illnesses and some disability. Longitudinal studies of the reliability and validity of subjective ratings of successful aging are warranted.

Aged↗

Immunologic response to antiretroviral therapy in hepatitis C virus-coinfected adults in a population-based HIV/AIDS treatment program.

BACKGROUND: We sought to characterize the impact that hepatitis C virus (HCV) infection has on CD4 cells during the first 48 weeks of antiretroviral therapy (ART) in previously ART-naive human immunodeficiency virus (HIV)-infected patients. METHODS: The HIV/AIDS Drug Treatment Programme at the British Columbia Centre for Excellence in HIV/AIDS distributes all ART in this Canadian province. Eligible individuals were those whose first-ever ART included 2 nucleoside reverse transcriptase inhibitors and either a protease inhibitor or a nonnucleoside reverse transcriptase inhibitor and who had a documented positive result for HCV antibody testing. Outcomes were binary events (time to an increase of > or = 75 CD4 cells/mm3 or an increase of > or = 10% in the percentage of CD4 cells in the total T cell population [CD4 cell fraction]) and continuous repeated measures. Statistical analyses used parametric and nonparametric methods, including multivariate mixed-effects linear regression analysis and Cox proportional hazards analysis. RESULTS: Of 1186 eligible patients, 606 (51%) were positive and 580 (49%) were negative for HCV antibodies. HCV antibody-positive patients were slower to have an absolute (P<.001) and a fraction (P = .02) CD4 cell event. In adjusted Cox proportional hazards analysis (controlling for age, sex, baseline absolute CD4 cell count, baseline pVL, type of ART initiated, AIDS diagnosis at baseline, adherence to ART regimen, and number of CD4 cell measurements), HCV antibody-positive patients were less likely to have an absolute CD4 cell event (adjusted hazard ratio [AHR], 0.84 [95% confidence interval [CI], 0.72-0.98]) and somewhat less likely to have a CD4 cell fraction event (AHR, 0.89 [95% CI, 0.70-1.14]) than HCV antibody-negative patients. In multivariate mixed-effects linear regression analysis, HCV antibody-negative patients had increases of an average of 75 cells in the absolute CD4 cell count and 4.4% in the CD4 cell fraction, compared with 20 cells and 1.1% in HCV antibody-positive patients, during the first 48 weeks of ART, after adjustment for time-updated pVL, number of CD4 cell measurements, and other factors. CONCLUSION: HCV antibody-positive HIV-infected patients may have an altered immunologic response to ART.

Acquired Immunodeficiency Syndrome↗

Development and pilot testing of a new psychosocial intervention for older Latinos with chronic psychosis.

Latinos constitute the largest minority in the United States, and there is an increasing number of Latino patients with schizophrenia and other psychoses living into old age. However, few specific behavioral interventions have been developed aimed at improving the functioning of this group. We evaluated a psychosocial intervention designed to improve the everyday living skills of middle-aged and older outpatients with very chronic psychotic disorders. Three psychiatric clinics, specializing in care of Latinos, were randomly assigned to (1) a 24-session intervention entitled Programa de Entrenamiento para el Desarrollo de Aptitudes para Latinos (PEDAL) group therapy (n = 21) targeting areas identified in our previous work as being problematic for this population (e.g., using public transportation) or (2) a time-equivalent friendly support group (SG; n = 8). Compared to the patients randomized to SG, PEDAL-treated patients' performance on everyday living skills improved significantly postintervention and was still significantly better at a 6-month maintenance follow-up period and at a 12-month no-treatment follow-up period. There was no significant change in psychopathology. Limitations of this pilot study are discussed. Results suggest that participation in this skills training program, designed specifically for older Latino patients with long-standing psychotic disorders, has the potential to significantly increase the patients' independence and improve functional skills.

Activities of Daily Living↗

Effect of serostatus for hepatitis C virus on mortality among antiretrovirally naive HIV-positive patients.

BACKGROUND: We examined the effect of hepatitis C virus (HCV) seropositivity on risk of death among people receiving their first antiretroviral treatment (ART) for HIV infection. METHODS: In British Columbia, the HIV/ AIDS Drug Treatment Program is the only source of free ART. Patients who initiated a triple-drug ART regimen between July 31, 1996, and July 31, 2000, were included if they were ART-naive and had baseline HCV serological data. Outcomes of interest for survival analysis were deaths from natural and HIV-related causes, with a data cutoff of June 30, 2003. RESULTS: Of 1186 eligible subjects, 606 (51%) were HCV positive and 580, negative. Fewer HCV-positive people were male (78% v. 93%, p < 0.001) and had an AIDS diagnosis at baseline (11% v. 15%, p = 0.028). Their CD4 fraction was significantly higher at baseline (19% v. 16% of T lymphocytes, p < 0.001) but their absolute CD4 counts, log HIV viral load and the type of ART initiated were similar to those of HCV negative people. Of 163 deaths (from natural causes only) during the study period, 118 (19%) were in HCV positive and 45 (8%) in HCV negative patients (p < 0.001); of the 114 deaths attributed to HIV infection, these proportions were 79 (13%) versus 35 (6%; p < 0.001). After adjustment for potential confounders, HCV seropositivity remained predictive of death (adjusted hazard ratio [HR] 2.20, 95% confidence interval [CI] 1.50- 3.21, p < 0.001), especially HIV-related death (adjusted HR 1.75, 95% CI 1.13- 2.72, p = 0.012). INTERPRETATION: In this population-based HIV treatment program, we found HCV seropositivity to be an independent predictor of mortality, especially death related to HIV infection.

Adult↗

Global IDEA.

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Biomedical Research↗

Impact of vitamin E and C supplementation on serum adhesion molecules in chronic degenerative aortic stenosis: a randomized controlled trial.

BACKGROUND: An inflammatory component has been identified in degenerative aortic stenosis (AS). The combination of vitamins E and C has been shown to have anti-inflammatory properties. The aim of this study was to determine the impact of the combination of vitamins C and E or vitamin C only on serum levels of cell adhesion molecules and C-reactive protein in patients with chronic degenerative AS, with or without concomitant coronary artery disease. METHODS AND RESULTS: One hundred patients with asymptomatic or mildly symptomatic moderate AS were randomized in 2:2:1 format in an open-label trial. Forty-one patients received vitamin E (400 IU) and vitamin C (1000 mg) daily, 39 patients received vitamin C (1000 mg) only, and 20 patients were followed as controls. Serum intracellular adhesion molecule (ICAM-1), E selectin, P selectin, vascular-cellular adhesion molecule (VCAM-1), C-reactive protein, and alpha-tocopherol (vitamin E) were measured by enzyme-linked immunosorbent assay at baseline and 6 months postsupplementation. Half of the patients from each of the 2 active groups were followed for further 6 months to determine any changes after cessation of therapy. In the vitamin E and C, group there was reduction in serum ICAM-1 (298 +/- 12 to 272 +/- 12 ng/mL at 6 months, P = .0015) with a return to base line 6 months after cessation of therapy. In the vitamin C only group, there was a reduction in serum P selectin (134 +/- 10 to 118 +/- 10 ng/mL at 6 months, P = .033). All the inflammatory markers were unchanged in control group over 6 months of follow-up. CONCLUSION: Vitamin E and C supplementation had modest anti-inflammatory effect in chronic degenerative AS. The clinical relevance of this would require further clarification.

Aged↗

Protecting health care workers from SARS and other respiratory pathogens: organizational and individual factors that affect adherence to infection control guidelines.

BACKGROUND: Traditional infection control policies have focused on engineering controls, specific protocols, and personal protective equipment (PPE). In light of the variable success in protecting health care workers (HCWs) from Severe Acute Respiratory Syndrome (SARS) in 2003, organizational and individual factors related to self-protective behavior in health care settings may also play an important role. METHODS: A critical review of the literature was conducted, directed at understanding what organizational and individual factors are important in protecting HCWs from infectious diseases at work. RESULTS: Organizational factors, such as a positive safety climate, have been associated with increased HCW adherence to universal precautions. There is some evidence that appropriate training of HCWs could be effective in changing HCW behavior if appropriate follow-up is applied. Very little research into these factors has been conducted with regard to preventing exposures to respiratory tract pathogens, but there was evidence from the SARS outbreaks that training programs and the availability of adequate PPE were associated with a decrease risk of infection. CONCLUSION: Variations in organizational and individual factors can explain much of the variations in self-protective behavior in health care settings. It is likely that these factors were also important determinants during the SARS outbreaks, but they have not been extensively studied.

Canada↗

Protecting health care workers from SARS and other respiratory pathogens: a review of the infection control literature.

BACKGROUND: Severe Acute Respiratory Syndrome (SARS) was responsible for outbreaks in Canada, China, Hong Kong, Vietnam, and Singapore. SARS focused attention on the adequacy of and compliance with infection control practices in preventing airborne and droplet-spread transmission of infectious agents. METHODS: This paper presents a review of the current scientific knowledge with respect to the efficacy of personal protective equipment in preventing the transmission of respiratory infections. The effectiveness of infection control policies and procedures used in clinical practice is examined. RESULTS: Literature searches were conducted in several databases for articles published in the last 15 years that related to infection control practices, occupational health and safety issues, environmental factors, and other issues of importance in protecting workers against respiratory infections in health care settings. CONCLUSION: Failure to implement appropriate barrier precautions is responsible for most nosocomial transmissions. However, the possibility of a gradation of infectious particles generated by aerosolizing procedures suggests that traditional droplet transmission prevention measures may be inadequate in some settings. Further research is needed in this area.

Humans↗

Molecular characterisation of Beauveria bassiana isolates obtained from overwintering sites of Sunn Pests (Eurygaster and Aelia species).

110 isolates of Beauveria (104 B. bassiana, 5 Beauveria spp., 1 B. brongniartii) were obtained from Sunn Pests (Eurygaster and Aelia species), litter, and other insect samples at overwintering sites in seven countries in the Middle East and West Asia. DNA was extracted from these isolates, and four techniques were used to characterize and to investigate genetic diversity at the molecular level: ITS-RFLP, ITS sequencing, ISSR-PCR, and AFLP. The ITS-RFLP and ITS sequences did not detect significant genetic variation among the isolates. However, both ISSR-PCR and AFLP analyses gave indications of intraspecific groupings correlated with geographical origin and relative genetic diversity among some isolates, but no obvious association with Sunn Pest hosts. There was no obvious genotypic grouping of B. bassiana isolates from E. integriceps, perhaps suggesting the overwintering populations were infected by generalist native isolates rather than by host-specific ones that might be more suitable for biocontrol purposes.

Animals↗

Back to work: correlates of employment among persons receiving highly active antiretroviral therapy.

The aim of this study was to quantify the level of employment at one-year and to determine potential predictors of future employment among HIV-positive persons on highly active antiretroviral therapy (HAART) in the province of British Columbia. Of the 392 individuals that were initially unemployed at baseline 63 (16.1%) found a job over the subsequent year. Factors associated with becoming employed included a baseline income over 10,000 dollars, having long-term disability or unemployment insurance as an income source, having higher CD4 cell counts, and better physical, social, and role functioning. Factors negatively associated with finding employment included having provincial assistance as an income source and having ever been an injection drug user (IDU). In multivariate analyses, not using provincial assistance as a source of income (Odds Ratio [OR] = 7.39; 95% CI: 3.26-16.7; p < 0.001) and higher MOS-SF role functioning (OR = 1.12 per 10 point increment; 95% CI: 1.03-1.21; p = 0.005) were independent predictors of becoming employed. In conclusion, our study demonstrates that while significant advances have been made in the reduction of HIV-related mortality, the majority of HIV-infected individuals on adequate treatment are still unable to be gainfully employed.

Adolescent↗