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Biomedical subjects

T Frazier

Publications and source records attributed to T Frazier.

11 recordsLinked to original sources
PubMed1999

The effect of temperature and solution pH on the nucleation of tetragonal lysozyme crystals.

Part of the challenge of macromolecular crystal growth for structure determination is obtaining crystals with a volume suitable for x-ray analysis. In this respect an understanding of the effect of solution conditions on macromolecule nucleation rates is advantageous. This study investigated the effects of supersaturation, temperature, and pH on the nucleation rate of tetragonal lysozyme crystals. Batch crystallization plates were prepared at given solution concentrations and incubated at set temperatures over 1 week. The number of crystals per well with their size and axial ratios were recorded and correlated with solution conditions. Crystal numbers were found to increase with increasing supersaturation and temperature. The most significant variable, however, was pH; crystal numbers changed by two orders of magnitude over the pH range 4.0-5.2. Crystal size also varied with solution conditions, with the largest crystals obtained at pH 5.2. Having optimized the crystallization conditions, we prepared a batch of crystals under the same initial conditions, and 50 of these crystals were analyzed by x-ray diffraction techniques. The results indicate that even under the same crystallization conditions, a marked variation in crystal properties exists.

Animals↗
PubMed1995

Assessment of mortality in the construction industry in the United States, 1984-1986.

Construction, one of the larger industries in the United States, employs 7.6 million workers, many in skilled trades occupations. Previously published data about potential worksite exposures and mortality of construction site workers are limited. We analyzed occupation and industry codes on death certificates from 19 U.S. states to evaluate mortality risks among men and women usually employed in construction occupations. Proportionate mortality ratios (PMRs) for cancer and several other chronic diseases were significantly elevated among 61,682 white male construction workers who died between 1984 and 1986. Men younger than age 65, who were probably still employed immediately prior to death, had significantly elevated PMRs for cancer, asbestos-related diseases, mental disorders, alcohol-related disease, digestive diseases, falls, poisonings, traumatic fatalities that are usually work-related, and homicides. Elevated PMRs for many of the same causes were observed to a lesser degree for black men and white women whose usual industry was construction. In addition, women experienced excess cancer of the connective tissue and suicide mortality. Various skilled construction trades had elevated PMRs for specific sites, such as bone cancer and melanoma in brickmasons, stomach cancer in roofers and brickmasons, kidney and bone cancer in concrete/terrazzo finishers, nasal cancer in plumbers, pulmonary tuberculosis in laborers, scrotal cancer and aplastic anemia in electricians, acute myeloid leukemia in boilermakers, rectal cancer and multiple sclerosis in electrical power installers, and lung cancer in structural metal workers. Using a standard population of blue collar workers did not result in fewer elevated PMRs for construction workers. Despite lifestyle differences and other limitations of the study, the large numbers of excess deaths observed in this study indicate the need for preventive action for construction workers.

Accidents, Occupational↗
PubMed1988

Smoking characteristics of US workers, 1978-1980.

Data from the 1978-1980 National Health Interview Survey smoking questionnaire were used to analyze prevalence and levels of cigarette smoking among groups of US workers. This information is valuable for indirect adjustment in occupational epidemiology studies as well as for describing smoking patterns of workers in a wide range of job settings. Although there was a higher percentage of current smokers among men than women in the general population, there were few differences in prevalence of smoking among men and women for specific occupations. Also, race and employment status had an influence on prevalence of smoking, where both the currently unemployed and blacks generally had a higher proportion of current smokers, although blacks generally had a higher proportion of current smokers, although blacks smoked fewer cigarettes. Industry also played a major role in the variation of smoking habits. For instance, the percentage of current smokers of a given occupation had as much as a 25% difference depending on the industry they were employed, such as 52% vs 26% for managers and administrators. Detailed data will be made available as microcomputer files for interested researchers.

Adolescent↗
PubMed1981

Occupational information on death certificates: a survey of state practices.

A national survey was conducted in 1979 to determine the extent to which state and local vital registration offices coded and stored occupational information reported on death certificates. This survey found that 11 states routinely code occupation, seven routinely code industry, and six have coded occupation and/or industry on a limited basis. State and federal cooperation is needed to facilitate increased use of mortality data for environmental and occupational health research.

Death Certificates↗
PubMed1980

Ambulatory medical care: a comparison of internists and family-general practitioners.

We analyzed data from the National Ambulatory Medical Care Survey to compare the style of practice of two primary-care providers, general internists and family-general practitioners. Whereas internists spent 18.4 minutes with the average patient, family-general practitioners spent 13.0 minutes. Whereas internists used laboratory tests in 73 per cent of visits and x-ray tests in 53 per cent, family-general practitioners used these studies in 34 and 19 per cent of visits. Internists provided instructions regarding health problems in 17.8 per cent of visits, and family-general practitioners in 12.4 per cent. The two provider groups did not differ in terms of therapy for emotional problems, both providing it in a relatively low proportion of visits (3 per cent). Whether by choice or necessity, family-general practitioners spent less time examining and instructing patients, and they ordered fewer laboratory and x-ray studies. The implications of these differences for the cost and quality of primary care need further study.

Ambulatory Care↗