Osteopenia is defined as a reduction in bone mass. It is commonly known to occur in elderly people or women who are postmenopausal due to hormonal imbalances. This condition, however, can result because of many other factors, such as poor nutrition, prolonged pharmacological intervention, disease, and decreased mobility. Because patients with cancer experience many of these factors, they are often predisposed to osteopenia. Currently, patients with cancer are living longer and leading more fulfilling lives after treatment. Therefore, it is imperative that therapists who are responsible for these patients understand the risk factors for osteopenia and their relevance to a patient with cancer. (+info)
Onchocerciasis and epilepsy: a matched case-control study in the Central African Republic.
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The occurrence of epileptic seizures during onchocercal infestation has been suspected. Epidemiologic studies are necessary to confirm the relation between onchocerciasis and epilepsy. A matched case-control study was conducted in dispensaries of three northwestern towns of the Central African Republic. Each epileptic case was matched against two nonepileptic controls on the six criteria of sex, age (+/-5 years), residence, treatment with ivermectin, date of last ivermectin dose, and the number of ivermectin doses. Onchocerciasis was defined as at least one microfilaria observed in iliac crest skin snip biopsy. A total of 561 subjects (187 cases and 374 controls) were included in the study. Of the epileptics, 39.6% had onchocerciasis, as did 35.8% of the controls. The mean dermal microfilarial load was 26 microfilariae per mg of skin (standard deviation, 42) in the epileptics and 24 microfilariae per mg of skin (standard deviation, 48) in the controls. This matched case-control study found some relation (odds ratio = 1.21, 95% confidence interval 0.81-1.80), although it was nonstatistically significant. (+info)
Evaluation of the quality of an injury surveillance system.
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The sensitivity, positive predictive value, and representativeness of the Canadian Hospitals Injury Reporting and Prevention Program (CHIRPP) were assessed. Sensitivity was estimated at four centers in June through August 1992, by matching independently identified injuries with those in the CHIRPP database. The positive predictive value was determined by reviewing all "injuries" in the database (at Montreal Children's Hospital) that could not be matched. Representativeness was assessed by comparing missed with captured injuries (at Montreal Children's Hospital) on demographic, social, and clinical factors. Sensitivity ranged from 30% to 91%, and the positive predictive value was 99.9% (i.e., the frequency of false-positive capture was negligible). The representativeness study compared 277 missed injuries with 2,746 captured injuries. The groups were similar on age, sex, socioeconomic status, delay before presentation, month, and day of presentation. Injuries resulting in admissions, poisonings, and those presenting overnight were, however, more likely to be missed. The adjusted odds ratio of being missed by CHIRPP for admitted injuries (compared with those treated and released) was 13.07 (95% confidence interval 7.82-21.82); for poisonings (compared with all other injuries), it was 9.91 (95% confidence interval 5.39-18.20); and for injuries presenting overnight (compared with those presenting during the day or evening), it was 4.11 (95% confidence interval 3.11-5.44). These injuries were probably missed because of inadequate education of participants in the system. The authors conclude that CHIRPP data are of relatively high quality and may be used, with caution, for research and public health policy. (+info)
Power and sample size calculations in case-control studies of gene-environment interactions: comments on different approaches.
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Power and sample size considerations are critical for the design of epidemiologic studies of gene-environment interactions. Hwang et al. (Am J Epidemiol 1994;140:1029-37) and Foppa and Spiegelman (Am J Epidemiol 1997;146:596-604) have presented power and sample size calculations for case-control studies of gene-environment interactions. Comparisons of calculations using these approaches and an approach for general multivariate regression models for the odds ratio previously published by Lubin and Gail (Am J Epidemiol 1990; 131:552-66) have revealed substantial differences under some scenarios. These differences are the result of a highly restrictive characterization of the null hypothesis in Hwang et al. and Foppa and Spiegelman, which results in an underestimation of sample size and overestimation of power for the test of a gene-environment interaction. A computer program to perform sample size and power calculations to detect additive or multiplicative models of gene-environment interactions using the Lubin and Gail approach will be available free of charge in the near future from the National Cancer Institute. (+info)
An IgG1 titre to the F1 and V antigens correlates with protection against plague in the mouse model.
(5/1739)
The objective of this study was to identify an immunological correlate of protection for a two-component subunit vaccine for plague, using a mouse model. The components of the vaccine are the F1 and V antigens of the plague-causing organism, Yersinia pestis, which are coadsorbed to alhydrogel and administered intramuscularly. The optimum molar ratio of the subunits was determined by keeping the dose-level of either subunit constant whilst varying the other and observing the effect on specific antibody titre. A two-fold molar excess of F1 to V, achieved by immunizing with 10 micrograms of each antigen, resulted in optimum antibody titres. The dose of vaccine required to protect against an upper and lower subcutaneous challenge with Y. pestis was determined by administering doses in the range 10 micrograms F1 + 10 micrograms V to 0.01 microgram F1 + 0.01 microgram V in a two-dose regimen. For animals immunized at the 1-microgram dose level or higher with F1 + V, an increase in specific IgG1 titre was observed over the 8 months post-boost and they were fully protected against a subcutaneous challenge with 10(5) colony-forming units (CFU) virulent Y. pestis at this time point. However, immunization with 5 micrograms or more of each subunit was required to achieve protection against challenge with 10(7) CFU Y. pestis. A new finding of this study is that the combined titre of the IgG1 subclass, developed to F1 plus V, correlated significantly (P < 0.05) with protection. The titres of IgG1 in vaccinated mice which correlated with 90%, 50% and 10% protection have been determined and provide a useful model to predict vaccine efficacy in man. (+info)
Is perforation of the appendix a risk factor for tubal infertility and ectopic pregnancy? An appraisal of the evidence.
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OBJECTIVE: To critically assess the evidence that appendiceal perforation is a risk factor for subsequent tubal infertility or ectopic pregnancy. DATA SOURCES: Epidemiologic studies investigating the relationship between appendectomy and infertility or ectopic pregnancy were identified by searching the MEDLINE database from 1966 to 1997. Appropriate citations were also extracted from a manual search of the bibliographies of selected papers. STUDY SELECTION: Twenty-three articles were retrieved. Only 4 presented original data including comparisons to a nonexposed control group and they form the basis for this study. DATA EXTRACTION: Because the raw data or specific techniques of data analysis were not always explicitly described, indices of risk for exposure were extracted from the data as presented and were analysed without attempting to convert them to a common measure. DATA SYNTHESIS: Articles were assessed according to the criteria of the Evidence-Based Medicine Working Group for evaluating articles on harm. Review of the literature yielded estimates of the risk of adverse fertility outcomes ranging from 1.6 (95% confidence interval [CI] 1.1 to 2.5) for ectopic pregnancy after an appendectomy to 4.8 (95% CI 1.5 to 14.9) for tubal infertility from perforation of the appendix. Recall bias, and poor adjustment for confounding variables in some reports, weakened the validity of the studies. CONCLUSIONS: The methodologic weaknesses of the studies do not permit acceptance of increased risk of tubal pregnancy or infertility as a consequence of perforation of the appendix, so a causal relationship cannot be supported by the data currently available. Only a well-designed case-control study with unbiased ascertainment of exposure and adjustment for confounding variables will provide a definitive answer. (+info)
Assessing public health capacity to support community-based heart health promotion: the Canadian Heart Health Initiative, Ontario Project (CHHIOP).
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This paper presents initial findings of the Canadian Heart Health Initiative, Ontario Project (CHHIOP). CHHIOP has two primary objectives. The programmatic objective is to coordinate and refine a system for supporting effective, sustained community-based heart health activities. This paper addresses the scientific objective: to develop knowledge of factors that influence the development of predisposition and capacity to undertake community-based heart health activities in public health departments. A systems theory framework for an ecological approach to health promotion informs the conceptualization of the key constructs, measured using a two-stage longitudinal design which combines quantitative and qualitative methods. This paper reports the results of the first round of quantitative survey data collected from all health departments in Ontario (N = 42) and individuals within each health department involved in heart health promotion (n = 262). Results indicate low levels of implementation of heart health activities, both overall and for particular risk factors and settings. Levels of capacity are also generally low, yet predisposition to undertake heart health promotion activities is reportedly high. Analyses show that implementation is positively related to capacity but not predisposition, while predisposition and capacity are positively related. Overall, results suggest predisposition is a necessary but not sufficient condition for implementation to occur; capacity-related factors appear to be the primary constraint. These findings are used to inform strategies to address CHHIOP's programmatic objective. (+info)
Immunologic parameters as predictive factors of cytomegalovirus disease in renal allograft recipients.
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Cytomegalovirus (CMV) disease is a major problem in renal transplant recipients, but few predictive markers of the disease are known. Several immunologic parameters of potential relevance for the defense against CMV were measured after renal transplantation in 25 patients before any manifestations of CMV infection occurred. In 10 patients who later developed CMV disease, plasma levels of interleukin-8 were significantly higher, whereas the levels of macrophage inflammatory protein-1alpha (MIP-1alpha) were significantly lower than in 15 patients who did not develop CMV disease. Also, lower numbers of CD4+ and CD8+ lymphocytes were observed in patients who later had CMV disease. These findings were independent of previous rejection therapy and were particularly pronounced in patients with primary CMV infection. Interleukin-8 and MIP-1alpha may be predictive markers of CMV disease and could be of potential use in selecting patients for prophylactic treatment. (+info)