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J Lynch

Publications and source records attributed to J Lynch.

297 records · Page 17Linked to original sources
PubMedDate not supplied

Role of exposure databases in risk assessment.

Risk assessments have assumed an increasingly important role in the management of risks in this country. The determination of which pollutants or public health issues are to be regulated, the degree and extent of regulation, and the priority assigned to particular problems are all areas of risk assessment that influence the country's $100 billion annual investment in environmental protection. Recent trends in public policy have brought the practice of risk assessment under greater scrutiny. As policy makers increasingly insist that specific numerical risk levels (so-called bright lines) be incorporated into regulatory decisions, the stakes for good risk assessment practice, already high, are raised even further. Enhancing the scientific basis of risk assessments was a major goal of the Workshop on Exposure Databases. In this article, we present the Risk Assessment Work Group's evaluation of the use of exposurerelated databases in risk assessment and the group's recommendations for improvement. The work group's discussion focused on the availability, suitability, and quality of data that underly exposure assessments, a critical component of risk assessment. The work group established a framework for evaluation, based on exposure scenarios typically used in regulatory decisions. The scenarios included examples from Superfund, the Clean Air Act, the Toxic Substances Control Act, and other regulatory programs. These scenarios were used to illustrate current use of exposure data, to highlight gaps in existing data sources, and to discuss how improved exposure information can improve risk assessments. The work group concluded that many of the databases available are designed for purposes that do not meet exposure and risk assessment needs. Substantial gaps exist in measurements of actual human exposure and in the data necessary to model exposures, to characterize distributions of exposure, to identify high-risk groups, and to identify possible environmental inequities in exposure. The work group, on the basis of its findings, made both short-term and longer-term recommendations for improving the collection of exposure data in the future.

Animals↗
PubMedDate not supplied

Relationship between premature mortality and socioeconomic factors in black and white populations of US metropolitan areas.

OBJECTIVE: examined the association of mortality with selected socioeconomic indicators of inequality and segregation among blacks and whites younger than age 65 in 267 US metropolitan areas. The primary aim of the analysis was to operationalize the concept of institutional racism in public health. METHODS: Socioeconomic indicators were drawn from Census and vital statistics data for 1989-1991 and included median household income; two measures of income inequality; percentage of the population that was black; and a measure of residential segregation. RESULTS: Age-adjusted premature mortality was 81% higher in blacks than in whites, and median household income was 40% lower. Income inequality, as measured by the Gini coefficient, was greater within the black population (0.45) than within the white population (0.40; p < 0.001). To confirm that the proxy socioeconomic variables were relevant markers of population health status, regression analysis was performed initially on data for the total population. These variables were all independently and significantly related to premature mortality (p < or = 0.01; R(2) = 0.74). Income inequality for the total population was significantly correlated with premature mortality (r = 0.33). Black (r = 0.26) and white (r = 0.20) population-specific correlations between income inequality and premature mortality, while still significant, were smaller. Residential segregation was significantly related to premature mortality and income inequality for blacks (r = 0.38 for both); among whites, however, segregation was modestly correlated with premature mortality (r = 0.19) and uncorrelated with income inequality. Regional analyses demonstrated that the association of segregation with premature mortality was much more pronounced in the South and in areas with larger black populations. CONCLUSION: Social factors such as income inequality and segregation strongly influence premature mortality in the US. Ecologic studies of the relationships among social factors and population health can measure attributes of the social context that may be relevant for population health, providing the basis for imputing macro-level relationships.

Adolescent↗
PubMedDate not supplied

Eradication of Cryptosporidium in a child undergoing maintenance chemotherapy for leukemia using high dose azithromycin therapy.

PURPOSE: To describe a case of severe diarrhea caused by Cryptosporidium in a patient undergoing maintenance chemotherapy. Important aspects of disease caused by Cryptosporidium, including diagnosis and treatment, are also reviewed. METHODS AND RESULTS: A 4-year-old boy with acute lymphoblastic anemia in remission had a prolonged course of diarrhea and wasting. C. parvum was identified in the gastrointestinal tract by biopsy and in the stool using modified acid fast staining. Improvement in the stool consistency was noted after 3 days of therapy with azithromycin, and, after 14 days of therapy, Cryptosporidium oocysts could no longer be identified in the stool. CONCLUSIONS: C. parvum should be considered in all immunocompromised patients with severe or prolonged diarrhea, especially if there is no blood or leukocytes in the stool. Because Cryptosporidium is not always tested for in a routine ova and parasite examination, the lab should be notified if it is in the differential diagnosis. Azithromycin therapy may prove beneficial in the treatment of intestinal Cryptosporidium in immunocompromised individuals.

Anti-Bacterial Agents↗
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Isolation and experimental chicken-embryo-inoculation studies with budgerigar papovavirus.

Attempts to isolate and identify budgerigar papovavirus (BPV) were made during three separate outbreaks of disease diagnosed on pathological grounds. Direct electron microscopy was successful only when large areas of skin were extensively disrupted to release virus and then extracted with fluorocarbon to remove lipids. Direct inoculation of budgerigar tissue suspensions into chicken embryos or chicken cell cultures failed to produce detectable virus. However, when primary cultures of liver and kidney were prepared from affected budgerigars, BPV could be detected by electron microscopy and by the production of a cytopathic effect at the third or fourth passage in cell cultures. The isolated virus was pathogenic for 10-day-old but not 11- or 12-day-old chicken embryos. Inoculated 11- and 12-day-old embryos produced antibodies to BPV that were detectable 2 weeks after hatching by agar-gel-immunodiffusion tests.

Animals↗
PubMedDate not supplied

Genetic counseling and HNPCC.

Cancer control objectives in HNPCC can be realized when patients who are at increased genetic risk receive intensive education about the natural history, as well as the surveillance and management recommendations that this diagnosis entails. It is only when family members are sufficiently informed about all of the pertinent clinical and genetic aspects of HNPCC that they can make the best possible decisions about those cancer control strategies which will likely impact heavily upon their lives. The sum total of these ramifications come under the rubric of genetic counseling. Our experience indicates that genetic counseling must embody all of the trust and confidence which is inherent in a physician/patient relationship. This involves the understanding that one is dealing with an ego-involved patient who may be very anxious and apprehensive about his or her cancer risk, as well as that of siblings and progeny. We have described the importance of psychodynamic factors which impact upon the genetic counseling process and often compel the counselor to assume the role of a psychotherapist.

Colorectal Neoplasms, Hereditary Nonpolyposis↗
PubMedDate not supplied

A working formulation for the standardization of nomenclature and for clinical staging of chronic dysfunction in lung allografts. International Society for Heart and Lung Transplantation.

A clinically applicable, standardized method for assessing functional results after lung transplantation is required to evaluate factors that may affect long-term outcome, to permit comparison of results from different centers, and to evaluate results of clinical trials. An ad hoc working group was established under the auspices of the International Society for Heart and Lung Transplantation for the purpose of developing such a clinically applicable system. Chronic allograft dysfunction is often associated with pathologic findings of obliterative bronchiolitis, the cause of which has not been defined. Physiologically, such dysfunction is associated with obstructive airways disease. The group concluded that the forced expiratory volume in 1 second was the most reliable and consistent indicator of graft dysfunction, excluding other identifiable causes. The term bronchiolitis obliterans syndrome was adopted to describe such dysfunction, recognizing that there may or may not be pathologic evidence of bronchiolitis obliterans present. Four stages of bronchiolitis obliterans syndrome were defined, each with two subcategories to indicate whether pathologic evidence of obliterative bronchiolitis had been identified. This working formulation will require reappraisal in the future to reassess its practical application and to make such adjustments as may seem appropriate.

Bronchiolitis Obliterans↗