The effect of ultraviolet radiation on the pathogenesis of {\it Candida albicans} in mice

Ultraviolet (UV) radiation produces immunological alterations in both humans and animals that include a decrease in the delayed type hypersensitivity (DTH) response to complex antigens, and to the induction of the suppressor T cell pathway. Cell-mediated immunity of the type that is altered by UV radiation has been shown to be important in host resistance against microorganisms. My dissertation addresses questions concerning the effects of UV radiation on the pathogenesis of opportunistic fungal pathogens such as Candida albicans.^ The (DTH) response of C3H mice exposed to ultraviolet (UV) radiation before (afferent arm of DTH) or after (efferent arm of DTH) infection with Candida albicans was markedly and systemically suppressed. Although suppression of both the afferent and efferent phases of DTH were caused by similar wavebands within the ultraviolet region, the dose of UV radiation that suppressed the efferent arm of DTH was 10-fold higher than the dose that suppressed the afferent arm of the DTH reaction.^ The DTH response of C57BL/6 mice was also suppressed by UV radiation; however the suppression was accomplished by exposure to significantly lower doses UV radiation compared to C3H mice. In C57BL/6 mice, the dose of UV radiation that suppressed the afferent phase of DTH was 5-fold higher than the dose that suppressed the efferent phase.^ Exposure of C3H mice to UV radiation before sensitization induced splenic suppressor T cells that upon transfer to normal recipients, impaired the induction of DTH to Candida. In contrast, the suppression caused by UV irradiation of mice after sensitization was not transferable. Spleen cells from sensitized mice exhibited altered homing patterns in animals that were exposed to UV radiation shortly before receiving cells, suggesting that UV-induced suppression of the efferent arm of DTH could result from an alteration in the distribution of effector cells.^ UV radiation decreased the survival of Candida-infected mice; however, no correlation was found between suppression of the DTH response and the course of lethal infection. This suggested that DTH was not protective against lethal disease with this organism. UV radiation also changed the persistence of the organism in the internal organs. UV-irradiated, infected animals had increased numbers of Candida in their kidneys compared to non-irradiated mice. Sensitization prior to UV irradiation aided clearance of the organism from the kidneys of UV-irradiated mice.^ These data show that UV radiation suppresses cell-mediated immunity to Candida albicans in mice and increases mortality of Candida-infected mice. Moreover, the data suggest that an increase in environmental UV radiation could increase the severity of pathogenic infections. ^

The effect of alcohol consumption on mortality among idiosyncratic drug induced liver injury (IDILI) patients

Severe liver injury (SLI) due to drugs is a frequent cause of catastrophic illness and hospitalization. Due to significant morbidity, mortality, and excess medical care costs, this poses a challenge as a public health problem. The role of associated risk factors like alcohol consumption in contributing to the high mortality remains to be studied. This study was conducted to assess the impact of alcohol use on mortality in IDILI patients, while adjusting for age, gender, race/ethnicity, and education level. The data from this study indicate only a small excess risk of death among IDILI patients using alcohol, but the difference was not statistically significant. The major contribution of this study to the field of public health is that it excludes a large hazard of alcohol consumption on the mortality among idiosyncratic drug induced liver injury (IDILI) patients. ^

The effect of immigration status on racial differences in health insurance coverage, access to care, and utilization in the United States

Background. Lack of coverage, lack of access, and failure to utilize health care services have all been linked to dismal health outcomes in the US. Such consequences have been a longstanding challenge that US minorities are faced with, in the context of a health care system believed to be lacking efficiency and equity. National population surveys in the US suggest that the number of uninsured approaches 50 millions, while some concerns and suspicions are raised by opponents to the growing number of foreign born US residents, many of whom are Hispanic. Research shows that race is a significant predictor of lack of coverage, access, and utilization, while age, gender, education, and income are also linked to these outcomes. We investigated the potential effect of immigration status or duration in the US on the association between coverage, access, use, and race. Methods. Using National Health Interview Survey (NHIS) data of 2006, we selected 22, 667 individuals of Non-Hispanic Black, Hispanic, and Non-Hispanic White descent, at least 18 years of age, US-born and foreign-born who reported their duration of residence in the US. Through complex sample survey logistic regression analysis, we computed odds ratios, beta coefficients, and 95% confidence intervals using models which excluded then included immigration status. Results. Although a significant predictor of the outcomes, immigration status did not change the relationship between each of the dependent variables (coverage, access, utilization), and the factor race, while adjusting for age, gender, education, and income. Our results show that Hispanics were least likely to have coverage (OR=.58; 95% CI[.49, .68]), access (OR=.62; 95% CI[.50, .76]), and to utilize services (OR=.60; 95% CI[.46, .79]) followed by Non-Hispanic Blacks, and Non-Hispanic Whites. These results were not changed by stratification, or the inclusion of interaction terms to eliminate the potential effect of relationships between independent variables. Recent immigrants (<5 years in US) were 0.12 times less likely to be insured, but also 0.26 times less likely to utilize services (p<0.001), and in addition they represented only 7.3% of the uninsured and 1.9% of the US population in 2006. Furthermore, 12% of the Non-Hispanic White population in the US was not covered, and 65% of the uninsured individuals were US-Born Citizens. Other predictors of lack of coverage, access and use were age below 45, male gender, education at high school or below, and income of less than $20,000. Conclusion. This investigation shows that the high percentage of uninsured was not directly caused by Hispanics, and immigration status alone could not explain racial differences in coverage, access, and utilization. An immigration reform may not be the solution to the healthcare crisis, and more specifically, will not stop the increase in the number of uninsured in the US, nor reduce the cost of health care. As a better alternative, universal health insu rance coverage should be considered, when aiming to eliminate racial disparities, and to solve the health care crisis. ^ Keywords. health insurance, coverage, access, utilization, race, immigration, disparities.^

THE EFFECT OF IRON SUPPLEMENT ON THE GROWTH OF RURAL INDONESIAN SCHOOL CHILDREN

The effect of oral iron supplementation on blood iron levels and physical growth in 119 Indonesian rural school children was assessed in the double-blind study. The children were classified into anemic and normal groups according to their initial hemoglobin and transferrin saturation levels and were randomly assigned to either iron or placebo treatment for twelve weeks. Biochemical, anthropometric and morbidity data were collected prior to and after the treatment period. Before treatment, anemic subjects were smaller and had higher morbidity than normal subjects. Treatment with 10 mg ferrous sulfate/kg/day for twelve weeks resulted in a significant improvement in blood iron biochemical status of the anemic subjects and in their growth velocity and morbidity. ^