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Biomedical subjects

K R Smith

Publications and source records attributed to K R Smith.

At least 55 records · Page 3Linked to original sources

Detection of Chlamydia trachomatis endocervical infections by ligase chain reaction versus ACCESS Chlamydia antigen assay.

Ligase chain reaction (LCR) was compared with ACCESS immunoassay for detection of chlamydial infections in females. Despite efforts to improve ACCESS performance by evaluation of specimens that were in the test performance "grey zone," LCR remained more sensitive and was less expensive to perform. ACCESS had a sensitivity of 83.9%, a specificity of 99.7%, a positive predictive value of 96.3%, and a negative predictive value of 98.5%.

Antigens, Bacterial↗

Familial context of genetic testing for cancer susceptibility: moderating effect of siblings' test results on psychological distress one to two weeks after BRCA1 mutation testing.

OBJECTIVES: To determine whether psychological distress differs among individuals tested for a BRCA1 mutation and is moderated by the pattern of their siblings' test results. MATERIALS AND METHODS: Participants in this study are members of a large kindred identified with a BRCA1 mutation. Subjects included 87 males and 125 females who completed a baseline interview, were tested for a BRCA1 gene mutation, received their results in person from a genetic counselor, completed a follow-up interview 1-2 weeks after the receipt of their test results, and had complete data on all variables used in the analysis. The main outcome of the study was psychological distress as measured by the Impact of Event Scale during the 1-2 week follow-up interview. Data were analyzed based on multiple regression. RESULTS: Male carriers, relative to noncarriers, experienced significantly more distress if they were the first tested than when all of their tested siblings were already known to be negative. Noncarrier males whose siblings all tested positive also encountered significant test-related distress. The largest adverse psychological consequences for female carriers, relative to noncarriers, were for those who were tested first and those whose tested siblings were noncarriers. CONCLUSIONS: The familial context in which genetic testing is conducted may be important for understanding how individuals react to their own test results.

Adult↗

How much global ill health is attributable to environmental factors?

Over the years, estimates have been made of the portions of human mortality and morbidity that can be attributed to environmental factors. Frustratingly, however, even for a single category of disease such as cancer, these estimates have often varied widely. Here we attempt to explain why such efforts have come to such different results in the past and to provide guidance for doing such estimates more consistently in the future to avoid the most important pitfalls. We do so by carefully defining what we mean by the terms "environmental," "ill health," and "attributable." Finally, based on these recommendations, we attempt our own estimate, appropriately qualified according to the many remaining uncertainties. Our estimate is that 25-33% of the global burden of disease can be attributed to environmental risk factors. Children under 5 years of age seem to bear the largest environmental burden, and the portion of disease due to environmental risks seems to decrease with economic development. A summary of these estimates first appeared in the 1997 report, "Health and Environment in Sustainable Development," which was the World Health Organization's contribution to the 5-year anniversary of the Rio Earth Summit. A full explanation of how these estimates were made is first presented here. We end with a call for a program of "strategic epidemiology," which would be designed to fill important gaps in the understanding of major environmental health risks in important population groups worldwide.

Causality↗

Health, environment and sustainable development: identifying links and indicators to promote action.

This paper discusses the links among health, environment, and sustainable development and presents a framework that extends from the epidemiological domain to the policy domain and includes the driving forces that generate environmental pressures, creating changes in the state of the environment and eventually contributing to human exposures. Health effects are the end result of this complex net of events. Environmental health interventions should not be limited to treatment of cases and directly reducing human exposures. The paper discusses the need for integrated action at all levels and, in particular, on the need to focus on long-term action directed at reducing the driving forces that generate the environmental health threats. Only this approach can achieve sustained health benefits and environmental protection in accord with the principles of sustainable development.

Decision Support Techniques↗

Against homoeopathy.

Explore the source record for details and available documents.

Evidence-Based Medicine↗

Privacy and confidentiality in the publication of pedigrees: a survey of investigators and biomedical journals.

CONTEXT: Pedigree diagrams efficiently communicate family information to genetics investigators; however, the publication of pedigrees poses a risk to the privacy and confidentiality of individuals depicted in the diagrams. Two sets of authoritative guidelines have been published to protect the privacy and confidentiality of subjects, but the influence of these guidelines on publication practices for pedigrees is unknown. OBJECTIVE: To determine the attitudes, practices, and experiences of investigators and journals with respect to privacy and confidentiality concerns in the publication of pedigrees. DESIGN: Investigators who have published pedigrees and editors of 26 biomedical journals were surveyed. Journals were reviewed for content in their "information for authors" sections and for documentation of informed consent in articles containing pedigrees. OUTCOME MEASURES: Practices regarding confidentiality and privacy reported by investigators and editors. RESULTS: Of 226 surveys sent to investigators, 177 were returned (78% response rate). Sixty-one investigators (36%) stated that family members were not informed that their pedigree would be published; 131 (78%) do not obtain informed consent specifically for pedigree publication and only 12 (28%) of the 43 who obtained consent obtained consent from all family members depicted. Thirty-two individuals (19%) reported having altered published pedigrees and 14 (45%) of 31 who had altered pedigrees stated that alterations were not disclosed to journals. Of the 14 journals that responded (54% response rate), only 3 reported written policies for managing potentially identifying information. Two journals reported having asked authors to alter pedigrees and 3 stated they had permitted alterations. A review of 5 genetics journals over a 2-year period revealed no documentation of consent for pedigree publication. CONCLUSIONS: Current practices in the publication of pedigrees do not conform with established recommendations and risk the privacy and confidentiality of subjects, often without informed consent. Attempts to address this problem through the alteration of data are being used, although this practice impairs the integrity of scientific communication.

Confidentiality↗

Urine-based screening of adolescents in detention to guide treatment for gonococcal and chlamydial infections. Translating research into intervention.

OBJECTIVES: To determine the utility of urine-based ligase chain reaction assays for Neisseria gonorrhoeae and Chlamydia trachomatis in (1) the acceptability of such testing to adolescent detainees, (2) the potential use of these tests for identifying asymptomatic infections, and (3) the effectiveness of this approach for ensuring treatment of infected adolescents. DESIGN: Cross-sectional screening and verification of treatment for infected cases. SUBJECTS: Adolescents admitted to a short-term juvenile detention center. MAIN OUTCOME MEASURES: Neisseria gonorrhoeae and C trachomatis infection rates, and timing and location of treatment for infected patients. RESULTS: Refusal rate was 1.5%. Of 263 participants, 46 (17.5%) were female subjects. Chlamydia trachomatis infections were identified in 28.3% of the female and 8.8% of the male subjects. Neisseria gonorrhoeae infections were present in 13.1% of the female and 2.8% of the male subjects. Overall, 37 participants (14%) were positive for N gonorrhoeae, C trachomatis, or both, only one of whom had symptoms. Almost 70% (25/36) of asymptomatic infected subjects were treated within 28 days of screening. A treatment was documented in 36 of the 37 infected youth, including 20 who were followed up and treated after release from the detention center, by 6 months after testing. CONCLUSION: Urine ligase chain reaction tests were effective for identifying and guiding treatment of unsuspected N gonorrhoeae and C trachomatis infections in teenagers admitted to a short-term detention center where traditional swab specimens may be difficult to obtain.

Adolescent↗

Manganese enhances phosphorylation of a 47 kD protein in retinoic acid-induced HL-60 cells.

We previously observed that HL-60 cells treated with manganese (Mn) during differentiation displayed an enhanced oxidative burst. Since a Mn-dependent kinase has been identified and phosphorylation is involved in burst activation, the objective of this research was to identify proteins in retinoic acid-induced HL-60 cells whose phosphorylation after phorbol myristate acetate (PMA) stimulation was affected by Mn treatment. Cells received Mn during differentiation and were then harvested, labeled with [32]P-orthophosphate, and stimulated with PMA. Cytosolic proteins were separated by isoelectric focusing, SDS-PAGE, and two-dimensional (2-D) gel electrophoresis. Time studies showed that Mn treatment did not alter the rate of PMA activated phosphorylation. Isoelectric focusing revealed that PMA stimulation resulted in the appearance of three phosphoproteins at pI's of 6.8, 7.3, and 7.8. Size separation gels showed a 200% increase in phosphorylation of a 47 kD protein in Mn-treated cells after stimulation. The 2-D gels showed that the pI of this protein was 6.8. Therefore, Mn treatment resulted in greater phosphorylation of a 47 kD protein, pI 6.8, in phorbol ester-stimulated cells.

Cell Differentiation↗

Mobilization of iron from coal fly ash was dependent upon the particle size and the source of coal.

Particulate air pollution, including coal fly ash, contains iron, and some of the pathological effects after inhalation may be due to reactive oxygen species produced by iron-catalyzed reactions. The objective of this study was to determine whether iron, present in coal fly ash, was mobilized, leading to ferritin induction in human airway epithelial cells, and whether the size of the particles affected the amount of iron mobilized. Three types of coal were used to generate the three size fractions of fly ash collected. The Utah coal fly ash was generated from a bituminous b coal, the Illinois coal fly ash from a bituminous c coal, and the North Dakota coal fly ash from a lignite a coal. Three size fractions were studied to compare the amount of iron mobilized in human airway epithelial (A549) cells and by citrate in cell-free suspensions. The size fractions selected were fine (<2.5 microm) and coarse (2.5-10 microm) components of PM10, airborne particulate matter <10 microm in diameter, and the fraction greater than 10 microm. Coal fly ash samples were incubated with 1 mM citrate to determine if iron associated with coal fly ash could be mobilized. Iron was mobilized by citrate from all three size fractions of all three coal types to levels as high as 56.7 nmol of Fe/mg of coal fly ash after 24 h. With all three coal types, more iron was mobilized by citrate from the <2.5 microm fraction than from the >2.5 microm fractions. Further, the mobilized iron was in the Fe(III) form. To determine if iron associated with the coal fly ash could be mobilized by A549 cells, cells were treated with coal fly ash, and the amount of the iron storage protein ferritin was determined after 24 h. Ferritin levels were increased by as much as 11.9-fold in cells treated with coal fly ash. With two of the three types of coal studied, more ferritin was induced in cells treated with the <2.5 microm fraction than with the >2.5 microm fractions. Further, inhibition of the endocytosis of the coal fly ash by the cells resulted in ferritin levels that were near that of the untreated cells, suggesting that iron was mobilized intracellularly, not in the culture medium. The results of this study suggest that differences in particle size and speciation of iron may affect the release of iron in human airway epithelial cells.

Air Pollutants, Occupational↗

Outcomes management of mechanically ventilated patients: utilizing informatics technology.

This article examines an informatics system developed for outcomes management of the mechanically ventilated adult population, focusing on weaning the patient from mechanical ventilation. The link between medical informatics and outcomes management is discussed, along with the development of methods, tools, and data sets for outcomes management of the mechanically ventilated adult population at an acute care academic institution. Pros and cons of this system are identified, and specific areas for improvement of future health care outcomes medical informatics systems are discussed.

Adult↗

Separate but lethal: the effects of economic segregation on mortality in metropolitan America.

The increase in income inequality in the United States over the past 20 years has been accompanied by a pronounced increase in economic segregation in urban areas. No research to date has analyzed the potential effects of such spatial segregation on mortality. To investigate these effects, the mortality experience of respondents aged 30 years and older on the 1986-94 National Health Interview Surveys residing in any one of 30 large metropolitan areas in the United States was analyzed. Concentrated poverty was associated with significantly elevated risk of mortality, even after controlling for individual household income. Concentrated affluence showed a consistent, protective effect only among the elderly. The effects were most pronounced among the poor, but were not confined to them. Urban planning should take into account the effects associated with economic residential segregation.

Health Status Indicators↗

13th meeting of the Scientific Group on Methodologies for the Safety Evaluation of Chemicals (SGOMSEC): alternative testing methodologies and conceptual issues.

Substantial world-wide resources are being committed to develop improved toxicological testing methods that will contribute to better protection of human health and the environment. The development of new methods is intrinsically driven by new knowledge emanating from fundamental research in toxicology, carcinogenesis, molecular biology, biochemistry, computer sciences, and a host of other disciplines. Critical evaluations and strong scientific consensus are essential to facilitate adoption of alternative methods for use in the safety assessment of drugs, chemicals, and other environmental factors. Recommendations to hasten the development of new alternative methods included increasing emphasis on the development of mechanism-based methods, increasing fundamental toxicological research, increasing training on the use of alternative methods, integrating accepted alternative methods into toxicity assessment, internationally harmonizating chemical toxicity classification schemes, and increasing international cooperation to develop, validate, and gain acceptance of alternative methods.

Animal Testing Alternatives↗

Phantom of the area: poverty-area residence and mortality in the United States.

OBJECTIVES: The purpose of the study was to conduct a national multivariate analysis on poverty-area residence and mortality in the United States. METHODS: Proportional hazards analyses were performed of the effect of poverty-area residence on the risk of mortality among adult examinees in the 1971 through 1974 National Health and Nutrition Examination Survey who were followed through 1987. RESULTS: Poverty-area residence was associated with significantly elevated risk of all-cause mortality (rate ratio = 1.78, 95% confidence interval = 1.33, 2.38) and some cause-specific mortality among those aged 25 through 54 years, but not among those aged 55 through 74 years, at baseline after adjustment for several individual and household characteristics. CONCLUSIONS: Residence in poverty areas contributes to socioeconomic gradients in mortality among nonelderly adults in the United States.

Adult↗

Effects of marital status on the risk of mortality in poor and non-poor neighborhoods.

PURPOSE: The purpose of this paper is to consider whether the mortality risks associated with marital status are conditioned by the socioeconomic quality of neighborhoods. METHODS: The analysis is based on the first National Health and Nutrition Examination Survey 1971-1974 (NHANES I), and the 1987 NHANES I Epidemiologic Followup Survey (NHEFS). Cox proportional hazards regressions were used to assess whether the effect of marital status on the risk of all-cause and cause-specific mortality is altered by local area poverty. Analyses are stratified by age, sex, and urbanicity. RESULTS: The interaction between neighborhood poverty and marital status is suggested for non-elderly men, particularly for cancer mortality and for men in urban areas. Interaction effects are evident among older women residing in urban areas. CONCLUSIONS: The absence of a spouse elevates the risk of mortality but this risk is moderately higher in impoverished neighborhoods, notably in urbanized areas, for non-elderly men and elderly women. Future studies with larger samples of non-married persons where marital status changes are incorporated are needed to improve our understanding of the joint mortality effects of local area poverty and marital status.

Adult↗