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Biomedical subjects

M Hampton

Publications and source records attributed to M Hampton.

10 recordsLinked to original sources
PubMed1998

Environmental tobacco smoke in the workplace induces oxidative stress in employees, including increased production of 8-hydroxy-2'-deoxyguanosine.

Environmental tobacco smoke (ETS) is a pervasive contaminant in the workplace. Our objective was to determine the oxidative stress effects of ETS on employees who are exposed. The results provide information that is useful to the resolution of risk assessment questions associated with ETS. We analyzed two blood draws from volunteers in our control and exposed groups. The level of exposure to ETS was determined through plasma cotinine measurements, which showed a 65% increase from the control group to the exposed group. Exposure to ETS resulted in a statistically significant increase of 63% of the oxidative DNA mutagen 8-hydroxy-2'-deoxyguanosine in the blood of exposed subjects. This oxidative DNA damage has been linked to an increased risk of developing several degenerative chronic diseases, including coronary heart disease and cancer. The exposed subjects also had increased levels of superoxide dismutase, catalase, glutathione peroxidase (GPOX), and glutathione reductase. However, these increases were only statistically significant in catalase and GPOX. Catalase levels were 13% higher in the exposed group, and GPOX levels were 37% higher in exposed volunteers. The biochemical evidence suggests that exposure to ETS causes oxidative stress, resulting in DNA damage that may increase the risk of certain diseases.

8-Hydroxy-2'-Deoxyguanosine↗
PubMed1998

Oxidative stress induced by environmental tobacco smoke in the workplace is mitigated by antioxidant supplementation.

Environmental tobacco smoke (ETS) is a pervasive contaminant in the workplace. Previous studies by this laboratory have shown that exposure to workplace ETS results in increased oxidative stress and damage, as measured by increased levels of the antioxidant enzymes superoxide dismutase, catalase, glutathione reductase, and glutathione peroxidase. 8-Hydroxy-2-deoxyguanosine, a marker of oxidative DNA damage, was also 63% greater in the exposed group compared with controls. Subjects in the previous study who reported workplace exposure to ETS were given a 60-day supply of an over-the-counter antioxidant formulation consisting of 3000 microg of beta-carotene, 60 mg of vitamin C, 30 I.U. of alpha-tocopherol, 40 mg of zinc, 40 microg of selenium, and 2 mg of copper. After the 60-day supplementation period, blood samples were again drawn, and the results were compared with the presupplementation values. A 62% decrease in 8-hydroxy-2-deoxyguanosine was observed after supplementation. Lipid peroxidation levels were also decreased, as were the antioxidant enzyme activities. The biochemical evidence suggests that exposure to ETS in the workplace increases oxidative stress and that antioxidant supplementation may provide some protection.

Adult↗
PubMed1996

A contaminant of L-tryptophan enhances expression of dermal collagen in a murine model of eosinophilia myalgia syndrome.

The eosinophilia-myalgia syndrome was associated with the ingestion of L-tryptophan products containing a number of contaminants, one of which has been identified as 1,1'-ethylidene-bis-(L-tryptophan) (EBT), also known as peak E or peak 97. In earlier studies, we demonstrated that EBT induces inflammation and fibrosis in dermal and subcutaneous tissue of C57BL/6 mice. Others have shown EBT to be a potent stimulus for fibroblast activation and collagen synthesis in vitro, and dermal tissue from EMS patients reveals evidence of enhanced collagen gene expression. In the present study using Northern blot analysis and in situ hybridization, we demonstrate enhanced expression of genes for types I, III, and VI collagen in the dermis and subcutis of C57BL/6 mice treated with EBT for 3-21 days. Increased type I procollagen mRNA was noted on day 6 of EBT treatment and was followed by enhanced expression of type III and VI procollagen mRNA at day 21. L-Tryptophan, free of contaminants associated with the eosinophilia-myalgia syndrome epidemic, increased dermal collagen mRNA to a lesser extent than did EBT. Increased procollagen gene expression was accompanied by evidence of enhanced TGF-beta 1 expression in the dermis and subcutis. This animal model provides additional evidence for EBT as a causal agent of the eosinophilia-myalgia syndrome and should prove useful in the study of the pathogenesis of that syndrome.

Animals↗
PubMed1994

A murine model of the eosinophilia-myalgia syndrome induced by 1,1'-ethylidenebis (L-tryptophan).

The eosinophilia-myalgia syndrome (EMS) is a recently described disease that has been associated with the ingestion of L-tryptophan containing trace amounts of several impurities. The first such contaminant to be identified and linked epidemiologically to the EMS epidemic was 1,1'-ethylidenebis(L-tryptophan) (EBT), but its role in the etiology and pathogenesis of the syndrome has been controversial. We report the development of inflammation and fibrosis affecting the dermis and subcutis, including the fascia and perimyseal tissues, after the daily intraperitoneal administration of EBT to female C57BL/6 mice. Such changes are accompanied by increased numbers of mast cells, many of which appear to be degranulating. Plasma levels of quinolinic acid, a metabolic product of L-tryptophan via the kynurenine pathway, are reduced initially, and then become elevated when inflammation and fibrosis are more pronounced. The nature and location of the inflammatory cell infiltrate and fibrosis, as well as the presence of mast cells and alterations of L-tryptophan metabolism, are consistent with findings reported in patients with EMS. This murine model suggests that EBT may have been one of the mediators of EMS and should facilitate studies of the pathogenesis of EMS.

Animals↗
PubMed1980

Racism.

Explore the source record for details and available documents.

Australia↗
PubMedDate not supplied

Provider resource planning. A study of methods in multispecialty groups and systems.

This article profiles the state of the art in provider resource planning based on a sample of large multispeciality group practices. Senior administrative representatives from a geographically dispersed sample of 12 practices, each employing over 100 physicians, participated in telephone interviews to discuss their respective organization's provider resource planning practices. There was significant variation with regard to the structural and process components and evaluation criteria used to plan provider resources. Variability was most pronounced by the lack of consensus and experience within and across organizations regarding the number and type of criteria deemed useful in evaluating new position requests. This research suggests that there is an opportunity to develop more objective provider resource planning methods that recognize differences across organizations and their respective markets. The authors recommend a series of research steps to develop methods that would identify needs prospectively, minimize the complexities of provider resource planning and maximize the alignment of strategic plans and operations.

Benchmarking↗
PubMedDate not supplied

The use of theory-based nursing practice in the Department of Veterans' Affairs Medical Centers.

In this study, the authors surveyed the chief nurses of 152 Veterans' Health Administration Medical Centers to determine which medical centers based their nursing practice on one or more nursing theories or models. Of the 76 medical centers responding, 24 (35%) stated theory-based practice was in use in their institutions. The greatest number (16 of the 24) reported use of Orem's Self-Care Deficit theory or a combination of Orem with other theories. Most of the 24 chief nurses agreed that theory-based practice: 1) improves patient outcomes; 2) maximizes patient health; and 3) provides a consistent approach to care. However, they were less convinced that theory-based practice reduces nursing staff turnover or improves job satisfaction. They also stated that theory-based practice is more important to nursing administrators than to staff nurses. A similar survey of staff nurses is recommended.

Data Collection↗