Health issues associated with societal evolution.
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Biological Evolution↗
Biomedical subjects
Gregory Taylor
Publications and source records attributed to Gregory Taylor.
Mice deficient in LRG-47 display enhanced susceptibility to Trypanosoma cruzi infection associated with defective hemopoiesis and intracellular control of parasite growth.
IFN-gamma is known to be required for host control of intracellular Trypanosoma cruzi infection in mice, although the basis of its protective function is poorly understood. LRG-47 is an IFN-inducible p47GTPase that has been shown to regulate host resistance to intracellular pathogens. To investigate the possible role of LRG-47 in IFN-gamma-dependent control of T. cruzi infection, LRG-47 knockout (KO) and wild-type (WT) mice were infected with the Y strain of this parasite, and host responses were analyzed. When assayed on day 12 after parasite inoculation, LRG-47 KO mice, in contrast to IFN-gamma KO mice, controlled early parasitemia almost as effectively as WT animals. However, the infected LRG-47 KO mice displayed a rebound in parasite growth on day 15, and all succumbed to the infection by day 19. Additional analysis indicated that LRG-47-deficient mice exhibit unimpaired proinflammatory responses throughout the infection. Instead, reactivated disease in the KO animals was associated with severe splenic and thymic atrophy, anemia, and thrombocytopenia not observed in their WT counterparts. In addition, in vitro studies revealed that IFN-gamma-stimulated LRG-47 KO macrophages display defective intracellular killing of amastigotes despite normal expression of TNF and NO synthetase type 2 and that both NO synthetase type 2 and LRG-47 are required for optimum IFN-gamma-dependent restriction of parasite growth. Together, these data establish that LRG-47 can influence pathogen control by simultaneously regulating macrophage-microbicidal activity and hemopoietic function.
Animals↗
In a retrospective study of chronic obstructive pulmonary disease inpatients, respiratory comorbidities were significantly associated with prognosis.
BACKGROUND AND OBJECTIVE: Comorbidities may be related to the prognosis for chronic obstructive pulmonary disease (COPD). We examined respiratory comorbidities associated with length of stay and in-hospital mortality among COPD patients. METHODS: We used the Hospital Person Oriented Information (HPOI) database of Statistics Canada for a 5-year period. Over 4 years (fiscal years 1994-1995 to 1998-1999), 143,135 records listed COPD as the most responsible diagnosis for men and 122,065 records for women aged 40 years or more, and 75,780 men and 69,539 women were admitted to hospital at least once. Logistic regression modeling was used to examine the relationships between respiratory comorbidities and hospital outcomes adjusting for covariates. RESULTS: Of the COPD patients, 10% had pneumonia-influenza and 3% had asthma as comorbid conditions. Women had a higher prevalence of asthma than men. The median length of stay at hospital was approximately 7 days, and 95% of patients were discharged alive. The odds ratio (95% confidence interval) for pneumonia-influenza in relation to in-hospital death was 3.56 (3.31, 3.83) for men and 3.29 (3.00, 3.61) for women. For comorbid asthma the corresponding odds ratios were 0.56 (0.36, 0.61) and 0.54 (0.35, 0.57), respectively. CONCLUSIONS: COPD inpatients with pneumonia-influenza had a worse prognosis and those with asthma had a better prognosis.
Adult↗
Changing age-pattern of hospitalisation risk of chronic obstructive pulmonary disease in men and women in Canada.
OBJECTIVE: To examine the changing pattern of age distributions of hospitalisation for chronic obstructive pulmonary disease (COPD) among Canadian men and women. DESIGN: Retrospective cohort study. PARTICIPANTS: 257,604 COPD inpatients aged 55-90 years with 463,089 hospital admissions during a 3-year study period (1994/95, 1995/96 and 1996/97) in Canada. MAIN OUTCOME MEASURES: COPD listed as one of the first five underlying diagnoses (broad definition, 463,089 hospitalisations) or as first diagnosis (narrow definition, 142,770 hospitalisations). RESULTS: Overall, men were more likely to have hospitalisations for COPD and had a higher proportion of death at hospital than did women. The 3-year cumulative incidence was 42.2/1,000 for the broadly defined COPD hospitalisation and 14.0/1,000 for the narrowly defined COPD hospitalisation, and steadily increased with increasing age. The relative risk for women versus men gradually increased with decreasing age, and was significantly greater than unity in the 55-59 year group for narrowly defined COPD hospitalisation. CONCLUSIONS: In terms of impact on secondary care COPD is a disease of the elderly and is becoming more common in women, particularly in younger age groups.
Age Distribution↗
Issues influencing development of the Canadian Cardiovascular Information Network.
The 1995 Consensus Conference of the Canadian Cardiovascular Society on "Indications for and Access to Revascularization" recommended that Canadian centres with invasive cardiovascular facilities should participate in a national observational database that monitors the selection of patients, as well as evaluate outcomes. The Canadian Cardiovascular Society, the Heart and Stroke Foundation of Canada, and Health Canada with IBM as a partner, initiated a process to identify factors influencing the development of the Canadian Cardiovascular Information Network. IBM's "Business Discovery Methodology" was adapted for health care. Structured interviews with representatives of health organizations, cardiovascular databases and research institutes were conducted across Canada, followed by a workshop to identify goals, issues and challenges. Participants identified goals for a cardiovascular database (eg, evidence-based decision-making), project related issues (eg, respecting the integrity of existing databases) and health care related issues (eg, cardiac waiting lists). Challenges included initial mistrust between representatives of provincial cardiovascular databases and national agencies, and a lack of sustained funding. A Project Team was formed to address 'cardiac waiting lists'. Analysis of Alberta and Ontario data identified differences in definitions, such as when the waiting time for bypass surgery began, that impeded detailed comparisons. Development of a centralized national database was not feasible at this time for political, technical and financial reasons. However, provincial cardiovascular database representatives agreed to work together and to share aggregate data and analyses. A first step toward developing a national surveillance system for cardiovascular services will be achieving consensus about standardizing data definitions. This process will require sustained funding.
Canada↗
Ecological measures of socioeconomic status and hospital readmissions for asthma among Canadian adults.
BACKGROUND: Lack of an association between area-based socioeconomic status (SES) and readmission for asthma was investigated in a country with a universal health care system. METHODS: Data linkage analysis was conducted based on hospitalization data from Statistics Canada's Person-oriented Information Database and area-based SES data from the 1996 Census. Hospital records for 8333 asthma patients aged 20-64 years in all Canadian provinces except Quebec who were admitted in 1995/1996 were linked to determine the number of patients who were rehospitalized within the same fiscal year. The area-based SES of the patients was defined according to the average personal income and proportion of residents with a university degree in an enumeration area (EA). Incidence rates of readmission for asthma were calculated based on the total years at risk. Cox's proportional hazard model was used to adjust for age, sex, province, and length of stay for first admission. RESULTS: The incidence rate of asthma rehospitalization was 31.6 per 100 person-years for men and 37.2 per 100 person-years for women. Neither average EA income or education level was significantly associated with rehospitalization for asthma. Women living in poor areas tended to have an increased incidence of asthma rehospitalization, but the difference was not significant after adjustment for covariates using the Cox regression model. CONCLUSION: Socioeconomic status measured at the neighborhood level has no significant impact on rehospitalization for asthma among Canadian adults.
Adult↗
Report of the 2003 pan-Canadian forum on cervical cancer prevention and control.
OBJECTIVE: To develop evidence-based consensus recommendations on the delivery of cervical cancer screening, human papillomavirus (HPV) education, HPV testing, and the optimal tool for cervical cytology within the Canadian health system. PARTICIPANTS: Leading up to a forum held in Ottawa on November 21 and 22, 2003, 254 registrants reviewed position papers through a Web-based discussion group. Experts in program management, clinical practice, epidemiology, public health, economics, and women's health, representing 48 organizations, then participated in the 2-day forum to develop consensus recommendations. EVIDENCE: Writing groups prepared position papers on optimal methods for cervical cytology; education concerning HPV; HPV testing in primary screening; HPV testing as a triage tool in cytopathology; and delivery mechanisms for cervical screening. Systematic reviews were the primary source of evidence supplemented by literature searches. CONSENSUS PROCESS: Feedback from Web-based discussions was incorporated into consecutive drafts of position papers. At the forum, recommendations and supporting evidence were presented, further debated in small-group sessions, and discussed in a plenary session. Despite divergent professional mandates and opinions, consensus was achieved on 15 recommendations across all areas. Final recommendations were posted to the Web for further input and circulated for written consensus by participants. CONCLUSIONS: The recommendations cover the use of new evidence and technologies in cervical cancer prevention in Canada and provide a framework for provision of HPV education, planning the implementation of new cervical screening technologies in Canada, the development of evaluation plans, and new research areas.
Canada↗
Challenges for social work in hemophilia care.
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British Columbia↗
Accumulation of 1,3-beta-D-glucans, in response to aluminum and cytosolic calcium in Triticum aestivum.
One of the most rapid responses to aluminum (Al) stress in plants is enhanced synthesis and deposition of 1,3-beta-D-glucans (callose) in root tips. Ironically, Al-induced synthesis and deposition of callose occurs in vivo, despite evidence from in vitro systems that suggests that Al is a powerful inhibitor of 1,3-beta-D-glucan synthase. We set out to test the hypothesis that an Al-induced increase in the activity of free calcium in the cytoplasm ([Ca(2+)](cyt)) is the trigger for enhanced synthesis of callose in in vivo systems, an effect that would not be observed in in vitro systems. Root tips of an Al-sensitive cultivar of Triticum aestivum were treated with Al (0-100 microM) or the Ca ionophore A23187 (0-3 micro M) for 3-24 h, and the effects on [Ca(2+)](cyt) and synthesis of callose were measured using confocal laser scanning microscopy. Treatment with Al induced a rapid increase in both [Ca(2+)](cyt) (4.7-fold) and synthesis of callose (30-fold). Treatment with the Ca ionophore, A23187, also elicited an increase in [Ca(2+)](cyt) (6.6-fold). Despite a greater increase in [Ca(2+)](cyt) in the presence of A23187, this increase was accompanied by a smaller increase in callose deposition (11-fold) than was observed in the presence of Al. These data suggest that an increase in [Ca(2+)](cyt) is not the only factor modulating increases in callose synthesis and deposition in the presence of Al.
Aluminum↗
Hospital readmissions for asthma in children and young adults in Canada.
To examine the incidence rate of hospital readmission for asthma in relation to sex and age among Canadian children and young adults, we used data from 86,863 subjects under age 20 years when they had a first admission for asthma as 1 of first 5 diagnoses in Canada between April 1, 1994 and March 31, 1997. We calculated age- and sex-specific incidence rates, and used the Cox proportional hazards model for multivariate analysis. Of these subjects, 20,277 (23.3%) were readmitted to hospital for asthma during the study period. After adjusting for length of stay for first admission and province, the rate ratio for females vs. males was 0.86 for those under age 1 year, and close to unity for the 1-4-year and 5-9-year age groups, whereas it was 1.47 and 1.35 for the 10-14-year and 15-19-year age groups, respectively. The data showed similar trends for rehospitalization asthma as a primary diagnosis. The incidence rate of rehospitalization showed little sex difference between ages 1-9 years, but was markedly higher in females than in males 10-19 years of age. Airway size, female hormonal changes, increased use of cosmetic products, and cigarette smoking among adolescent girls may contribute to the age- and sex-differences in adolescence.
Adolescent↗
Sex difference in hospitalization due to asthma in relation to age.
To describe the sex and age differences in asthma hospitalization among the Canadian population, we conducted an analysis based on a total of 9,486,173 hospital records in Canada for a 3-year period (1994/1995, 1995/1996, and 1996/1997), including 204,304 asthma patients and 288,977 asthma-related records. Asthma as one of the first five diagnoses, accounted for 3.0% of total hospitalizations, which was almost constant across the 3-year study period. The 3-year cumulative incidence of asthma hospitalization was substantially higher for young boys than girls, and it was reversed for adults. The incidence ratio for females vs. males for asthma hospitalization reached 2.8 for individuals 25 to 34 years of age, decreased gradually with increasing age, and then approached unity for those aged 80 years or more. The data suggest that sex is an important determinant for asthma, and the sex effect varies considerably over a life span.
Adolescent↗
Genital dysplasia in women infected with human immunodeficiency virus.
BACKGROUND: Women infected with human immunodeficiency virus (HIV) are at increased risk for the development of dysplastic genital lesions. Traditionally, markers of immunosuppression were predictive of the development of dysplasia. Recent advances in antiretroviral medications allow restoration of a once-depressed CD4+ cell count and suppression of HIV replication. In this new era, additional predictive markers of genital dysplasia are needed for management of women infected with with HIV. OBJECTIVE: To find predictive markers of genital dysplasia in women infected with HIV. DESIGN: Observational study of a consecutive sample of 200 women infected with HIV from an urban university clinic. Measurements of histopathology, CD4+ count, CD4+ nadir, HIV viral load, human papillomavirus (HPV), and usage of highly active antiretroviral therapy (HAART) were evaluated for an association with genital dysplasia. RESULTS: There was a trend toward a protective effect against any genital dysplasia when HAART had been prescribed [relative risk = 0.77, 95% confidence interval (CI) 0.56, 1.06] and HAART therapy resulted in an immune response (relative risk, 0.61; 95% CI, 36, 1.02). High-risk HPV DNA was a strong predictor of dysplasia (P =.0003). A lower CD4+ count nadir was strongly associated with genital dysplasia (P =.0003). CONCLUSION: A history of greater immunosuppression, as measured by the nadir of a patient's CD4+ count, is the strongest predictor of genital dysplasia in women infected with HIV.
AIDS-Related Opportunistic Infections↗