Publication Type: Abstract
Abstract: Diagnostic agents capable of accurately identifying a causative bacterial pathogen would allow clinicians to more rapidly provide appropriate treatment to patients. Such diagnostic agents would decrease unnecessary use of broad-spectrum antibiotics and allow a more tailored approach to treatment. We propose the development of radiolabeled bacteriophage that would specifically identify the causative bacterial agents. Bacteriophage (phage) are viruses that infect bacteria exclusively, showing no affinity for mammalian cells. Our work involved radiolabeling bacteria-specific phage. Our hypothesis is that Tc-99m-labeled phage with the correct specificity could be utilized as a valuable diagnostic aids via nuclear medicine imaging, in cases where bacterial infections were suspected. Objectives: to show 1) that Tc-99m-MAG3 could be used to label a phage of interest; 2) that the labeled phage could differentiate between different bacteria in-vitro; and 3) that a radiolabeled phage could specifically bind bacteria in-vivo. Methods: Escherichia coli (strains ER2537 and 25922), Staphylococcus aureus (strain 29213) and Salmonella typhimurium were used as targets for M13KE and P-22 phage. S-acetyl NHS-MAG3 was conjugated to the phage, then radiolabeled with Tc-99m. Experiments were performed to assess in-vitro specificity of the phage, stability of the radiolabel in serum, and the biodistribution of radiolabeled phage in mice. Results: Radiolabeled phage displayed selectivity in bacterial binding in-vitro, stability in serum, and their biodistribution revealed selectivity of uptake in infected versus inflamed tissue, though liver uptake was also noted. Implications: Radiolabeled phage may be useful tools for in-vivo identification of bacteria

Publication Type: Conference Paper/Unpublished Manuscript
Review Method: Peer Reviewed
Abstract: Acute respiratory infection (ARI) is the most prevalent illness globally, and is a leading cause of child death in developing countries. In Vietnam, this disease remains the leading cause of mortality and morbidity in children under five years of age. Although research in other developing countries has found that maternal education has a strong effect on children’s health, such studies have not been widely undertaken in Vietnam.

Using data drawn from the 1997 Vietnam Demographic and Health Survey, this study examines the relationship between maternal education and knowledge and practice in childhood acute respiratory infections care in Vietnam. The paper also attempts to identify the mechanisms that underlying these relationships. Logistic regression is used for the analysis.

The results indicate that maternal education has a significant impact on both knowledge and practice in ARI care. Educated mothers are more likely to have better knowledge of ARI care and are more likely to seek for medical treatment when their children had ARI. Other factors such as mothers’ occupation, fathers’ education and the availability of health programs also play a role in predicting the likelihood of mothers’ knowledge of ARI. The economic condition in the household is found to have an impact on mothers’ health seeking practice when their children had ARI.

My research suggests that the Vietnamese government needs to not only improve the level of schooling for women, but also provide them with more specific health education regarding child ARI care. By doing so, mothers will be able to provide correct and timely treatment to minimize the level of preventable deaths in children due to ARI.

Publication Type: Conference Paper/Unpublished Manuscript
Review Method: Peer Reviewed
Abstract: This paper has two primary goals. (1) Based on the interview records of Syphilis infected people in eight STD specialty clinics in Chicago area, it identifies bridging communities that mediates or bridges two otherwise sexually-rarely-connected communities. Quite interesting and important is the finding that there exist communities that have low infection rates and thus, are largely ignored in the previous studies because of their own low infection rates although they may require special preventive efforts because of their essential role as bridges in transmitting STDs to the whole population. (2) It examines the racial/ethnic difference in the structure of inter-community sexual ties in order to explain the discrepancy in the prevalence of STDs. African Americans are more active in bridging than whites: on average, African Americans are eight times more likely to have non-redundant sexual ties between communities: 2.9 ties vs. 0.5 ties. This fact alone makes the odd of being infected among African Americans be necessarily higher than the one among white people even after controlling for other risk factors. This network effect cannot be detected in traditional regressions that include only individual-level risk factors.

Publication Type: Conference Paper/Unpublished Manuscript
Review Method: Peer Reviewed
Abstract: This presentation investigates behaviors that may be associated with HIV infection among women who use and/or sell crack, powder cocaine and heroin in Central Harlem. Chain referral sampling and other strategies were combined to interview 281 female drug users (N=248) and sellers (N=33) who were tested for HIV infection. Chi-square analysis was used to identify factors associated with HIV infection, and logistic regression analysis was used to ascertain the relative importance of these factors.
More than a fourth (28.5 percent) of all respondents were HIV positive. Thirteen factors were significantly associated with HIV infection in chi-square analyses. In logistic regression analyses, injection drug users were three times more likely to be HIV positive than other women (OR=3.29; 95 percent CI: 1.63—6.66). Latinas (OR=2.84; 95 percent CI: 1.12—7.16), women involved in illegal activities (OR=2.82; 95 percent CI: 1.55—5.14) or women who were separated, divorced or widowed (OR=2.13, 95 percent CI: 1.16—3.90) were more than twice as likely to have HIV. This study adds to previous research that drug injection was the most statistically significant factor associated with HIV infection. However, Latina ethnicity and lifestyle factors that involve income from illegal activities and relationship status were independently associated with HIV infection.

Publication Type: Conference Paper/Unpublished Manuscript
Abstract: Why do children get sick more often when in nonmaternal child care and what are the consequences for maternal employment? We propose that a complete answer to this question requires moving beyond simple analyses of the location of care (center or private home) to identifying characteristics of care settings that bridge children to additional disease networks and bridge providers to information about infection control practices. We estimate fixed effects models using a hospital-based sample of over 1,100 children from the 1991 National Institute of Child Health and Human Development Study of Early Child Care. We document that the incidence of respiratory illness is greater for children in large family day care homes (with five or more children in care) relative to small family day care homes. Unexpectedly, disease incidence does not differ when in-home caregivers live inside or outside of the child’s home. And, children in small, home-based care show lower disease risk than do children in exclusive maternal care. Risk of disease transmission is lower when small family day care providers belong to professional organizations, apparently due to their more effective infection control practices which in turn reduce disease risk. We also document that differential disease risks associated with different settings exacerbate social inequality, since the settings most associated with child illness – centers and large family day care – are also the settings most associated with mothers staying home from work when the child is ill.

Supporting Publications:
Supporting Document