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Biomedical subjects

D Hemenway

Publications and source records attributed to D Hemenway.

18 recordsLinked to original sources
PubMed1992

Loaded guns in the home. Analysis of a national random survey of gun owners.

OBJECTIVE: To identify factors associated with keeping guns loaded. Four hypotheses were tested: that people are more likely to keep their firearms loaded if (1) the primary reason for owning a gun is protection, (2) the gun is a handgun, (3) there are no children in the household, or (4) the gun owner has not received training in the proper use of firearms. DESIGN AND SETTING: A random national telephone survey of gun owners conducted in December 1989. A screening question was used to identify individuals as gun owners. Participants were called at home. PARTICIPANTS: 605 individuals (approximately two thirds of the population contacted) participated in the survey. All were 18 years and older, most were men (64%), and a few were nonwhite (12%). The majority owned more than one gun (77%). RESULTS: Three of the four hypotheses were substantiated by the data. Handgun owners (odds ratio [OR], 2.17; 95% confidence interval [CI], 1.67 to 2.82), individuals who owned a firearm principally for protection (OR, 1.65; 95% CI, 1.30 to 2.11), and people who lived in households without children (OR, 1.42; 95% CI, 1.13 to to 1.82) were all more likely to keep a gun loaded than other individuals. Instruction in the proper use of firearms did not seem to affect the probability of keeping guns loaded (OR, 0.86; 95% CI, 0.69 to 1.07). CONCLUSIONS: The spontaneous nature of many firearm deaths has led to speculation that a substantial proportion of firearm-related morbidity and mortality could be prevented if easy access to loaded weapons were reduced through appropriate storage practices. Our findings show that a significant proportion of gun owners disregard basic safety procedures. However, without information on the specific content of safety instruction, we cannot say that education about safe storage practices is ineffective.

Adult↗
PubMed1992

Expression of antioxidant enzymes in rat lungs after inhalation of asbestos or silica.

Several studies indicate that active oxygen species play an important role in the development of pulmonary disease (asbestosis and silicosis) after exposure to mineral dust. The present study was conducted to determine if inhaled fibrogenic minerals induced changes in gene expression and activities of antioxidant enzymes (AOE) in rat lung. Two different fibrogenic minerals were compared, crocidolite, an amphibole asbestos fiber, and cristobalite, a crystalline silicon dioxide particle. Steady-state mRNA levels, immunoreactive protein, and activities of selected AOE were measured in lungs 1-10 days after initiation of exposure and at 14 days after cessation of a 10-day exposure period. Exposure to asbestos resulted in significant increases in steady-state mRNA levels of manganese-containing superoxide dismutase (MnSOD) at 3 and 9 days and of glutathione peroxidase at 6 and 9 days. An increase in steady-state mRNA levels of copper, zinc-containing superoxide dismutase (CuZnSOD), was observed at 6 days. Exposure to asbestos also resulted in overall increased enzyme activities of catalase, glutathione peroxidase and total superoxide dismutase in lung. In contrast, silica caused a dramatic increase in steady-state levels of MnSOD mRNA at all time periods and an increase in glutathione peroxidase mRNA levels at 9 days. Activities of AOE remained unchanged in silica-exposed lungs. In both models, increases in gene expression of MnSOD correlated with increased amounts of MnSOD immunoreactive protein in lung and the pattern and extent of inflammation. These data indicate that the profiles of AOE are dissimilar during the development of experimental asbestosis or silicosis and suggest different mechanisms of lung defense in response to these minerals.

Animals↗
PubMed1992

What is the dentist's occupational risk of becoming infected with hepatitis B or the human immunodeficiency virus?

Surveys have shown that dentists are reluctant to treat persons infected with the human immunodeficiency virus (HIV). However, dentists are much more willing to treat patients with infectious hepatitis B virus (HBV). This study shows that the annual cumulative risk of infection from routine treatment of patients whose seropositivity is undisclosed is 57 times greater from HBV than from HIV, and that the risk of dying from HBV infection is 1.7 times greater than the risk of HIV infection, for which mortality is almost certain.

Attitude of Health Personnel↗
PubMed1991

The second best in statistics.

When estimating a parameter, it may not be possible to remove all sources of bias. Yet a priori we do not know whether eliminating some sources will improve or worsen the estimate.

Bias↗
PubMed1991

Quality of care in a chain of walk-in centers.

Several aspects of quality of care at one chain of freestanding ambulatory health care walk-in centers were evaluated. Those areas for which data were available--medical record review, physician credentials, and patient satisfaction--suggest that for primary acute episodic care, HSMMI walk-in centers provided care comparable to that which would have been received in traditional health care settings. In fact, HSMMI offices were found to be similar in organizational structure and appeared very much like private physicians' offices in management, staffing, patient flow, and physician performance. The corporation's QA program evolved from a series of informal managers' meetings (in 1986), to a detailed and structured program involving a CEO and regional medical directors by the end of 1990. The exact way in which HSMMI's new emphasis on formal quality-of-care assessment and assurance will affect patient care will be seen as the program fully matures. The issue of the proper relationship between money and medicine remains a problem. As health services organizations are increasingly influenced by market forces and consumers have ever-higher expectations, patients and physicians alike want to be sure that high-quality health care remains the first priority. Although this is an issue for all providers, it is much more visible in proprietary offices, making physicians as well as the public uneasy. For this reason, HSMMI's burden of proof regarding quality may be higher--particularly within the medical community--than the burden on traditional private practice physicians.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1991

Development and characterization of a rapid-onset rodent inhalation model of asbestosis for disease prevention.

A short-term inhalation model of asbestosis was developed in rodents to examine possible preventive approaches to lung disease. Fischer 344 (F344) rats were exposed for 10 and 20 days to National Institute of Environmental Health Sciences (NIEHS) crocidolite asbestos while sham controls were exposed to air only. To determine quantitative biochemical indicators of asbestos-induced lung disease, bronchoalveolar lavage (BAL) fluids were analyzed for lactic dehydrogenase (LDH), alkaline phosphatase, angiotensin-converting enzyme (ACE), and protein. Total and differential cell counts were performed on cell pellets from BAL. Lungs from additional rats were processed for histopathology, measurement of hydroxyproline, and autoradiography after injection of rats with 3H-thymidine. Exposure to asbestos for 10 and 20 days caused increases in LDH, alkaline phosphatase, and protein in BAL. In contrast, ACE was undetectable in BAL fluids from sham or asbestos-exposed rats. At both time periods, the percentages of polymorphonuclear leukocytes (PMNs) and lymphocytes in BAL were increased in asbestos-exposed rats. Total cell numbers in BAL were increased significantly at 20 days in animals inhaling asbestos. Exposure to asbestos for 10 and 20 days caused elevated amounts of hydroxyproline in lung and the development of fibrotic lesions. Asbestos-exposed rats exhibited increased numbers of interstitial cells and airspace epithelial cells incorporating 3H-thymidine, whereas labeled bronchiolar epithelial cells were not elevated significantly. The quantitative changes in asbestos-associated enzyme levels, cell types and protein in BAL, as well as increases in hydroxyproline and morphologic evidence of fibrosis, are useful indices of asbestos-related lung injury which enable preventive and therapeutic approaches to disease.

Administration, Inhalation↗
PubMed1991

Radiographic abnormalities in Vermont granite workers exposed to low levels of granite dust.

The issue of whether low levels of granite dust exposure lead to radiographic abnormalities after a lifetime of exposure has not been settled. In 1983, we carried out a radiographic survey of the Vermont granite industry, consisting of quarry and stone shed workers who had been exposed to the low dust levels prevailing in the industry since 1938 to 1940. Films were read by three "B" readers, using the ILO classification system, which requires the identification of both rounded and irregular opacities, as well as combinations of both. X-ray films were taken of 972 workers, out of a total work force of approximately 1,400. Of these films, 28 (3 percent) were interpreted by either two or three of the three readers as showing abnormalities consistent with pneumoconiosis. Only seven films (or 0.7 percent of the entire cohort) showed nodular or rounded opacities of the type typically seen in uncomplicated silicosis. The remainder of the abnormal x-ray films showed irregular opacities, largely in the lower lung zones, which are of uncertain significance, but may be related to heavy cigarette smoking and aging, and possibly dust inhalation. In addition, total gravimetric dust concentrations in the workplace were measured; 417 respirable-size mass samples showed concentrations of 601 micrograms/cu m +/- 368 micrograms/cu m. Using previously published estimates of 10 percent quartz in granite dust, the average quartz concentration was 60 micrograms/cu m. Twelve percent of the samples exceeded 100 micrograms/cu m, the current OSHA standard for quartz. We conclude that control of quartz exposure in the Vermont granite industry to levels which are on average less than the current OSHA standard has essentially eliminated definite radiographic changes of silicosis. The significance of the irregular opacities in the lower lung zones seen on a majority of the 28 x-ray films judged to be abnormal is not clear.

Adult↗
PubMed1991

Injury prevention.

Explore the source record for details and available documents.

Accident Prevention↗
PubMed1990

Physicians' responses to financial incentives. Evidence from a for-profit ambulatory care center.

Health Stop is a major chain of ambulatory care centers operating for profit. Until 1985 its physicians were paid a flat hourly wage. In the middle of that year, a new compensation plan was instituted to provide doctors with financial incentives to increase revenues. Physicians could earn bonuses the size of which depended on the gross incomes they generated individually. We compared the practice patterns of 15 doctors, each employed full time at a different Health Stop center in the Boston area, in the same winter months before and after the start of the new arrangement. During the periods compared, the physicians increased the number of laboratory tests performed per patient visit by 23 percent and the number of x-ray films per visit by 16 percent. The total charges per month, adjusted for inflation, grew 20 percent, mostly as a result of a 12 percent increase in the average number of patient visits per month. The wages of the seven physicians who regularly earned the bonus rose 19 percent. We conclude that substantial monetary incentives based on individual performance may induce a group of physicians to increase the intensity of their practice, even though not all of them benefit from the incentives.

Ambulatory Care Facilities↗
PubMed1990

The effect of climate on fractures and deaths due to falls among white women.

Climatic conditions may affect the incidence of fractures and fall deaths. Analysis of national fatality data shows that among white women, those living in colder climates have higher rates of fall deaths. Fall deaths increase in winter in all regions, but especially so in colder states. In a prospective cohort study of 96,506 predominantly white female nurses 35-59 years of age, we found that, after controlling for personal and lifestyle characteristics, those women residing in colder climate also had a higher incidence of hip and forearm fracture. In colder states, fracture rates were substantially higher in winter than in summer. A cold climate appears to be a significant risk factor for both fractures and fall deaths among white women, particularly as they age.

Accidental Falls↗
PubMed1990

Physician satisfaction in a major chain of investor-owned walk-in centers.

This article describes physicians at a major chain of investor-owned free-standing walk-in centers and reports on their job satisfaction. They derived satisfaction from a sense of autonomy and the corporation's reliable provision of staff and supplies. Their job dissatisfaction results from the corporate emphasis on generating revenue and the lack of opportunity for professional interaction with colleagues.

Adult↗
PubMed1990

Inhibition of lung injury, inflammation, and interstitial pulmonary fibrosis by polyethylene glycol-conjugated catalase in a rapid inhalation model of asbestosis.

Several in vitro studies suggest the involvement of active oxygen metabolites in cell damage caused by asbestos. To determine if lung injury, inflammation, and asbestosis could be inhibited in vivo in a rapid-onset, inhalation model of disease, a novel method of chronic administration of antioxidant enzymes was developed. In brief, Fischer 344 rats were treated with polyethylene glycol-conjugated (PEG-) superoxide dismutase or catalase in osmotic pumps over a 10-day (5 days/wk for 2 wk) or 20-day (5 days/wk for 2 wk) period of exposure to crocidolite asbestos. Control rats included sham-exposed animals and those exposed to asbestos but receiving chemically inactivated enzymes. After 10 days of exposure to asbestos, lactic dehydrogenase (LDH), alkaline phosphatase, and total protein in bronchoalveolar lavage (BAL) were measured in one group of rats. Total and differnetial cell counts in BAL also were assessed. After 20 days of exposure, lungs of an additional group of rats were evaluated by histopathology and by measurement of hydroxyproline. Asbestos-associated elevations in LDH, protein, and total cell numbers in BAL were reduced in rats receiving PEG-catalase. Decreases in numbers of alveolar macrophages, polymorphonuclear leukocytes, and lymphocytes occurred in these animals. Exposure to asbestos for 20 days caused significant increases in both the amount of hydroxyproline in lung and the severity and extent of fibrotic lesions as determined by histopathology. These indicators of asbestosis were inhibited in a dosage-dependent fashion in rats receiving PEG-catalase. Use of inactivated PEG-catalase failed to boost serum levels of catalase and did not inhibit asbestos-induced elevation of hydroxyproline in lung.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1988

Fractures and lifestyle: effect of cigarette smoking, alcohol intake, and relative weight on the risk of hip and forearm fractures in middle-aged women.

Cigarette smoking, alcohol consumption and low relative weight are often cited as risk factors for osteoporosis. In a prospective cohort study of 96,508 middle-aged nurses 35 to 59 years of age we found that smoking was not a risk factor for hip and forearm fracture. Women who drank more than 15 grams of alcohol per day and whose relative weight was less than 21 kg/m2 were at increased risk of fractures, but these risk factors were not independent. Only the combination of alcohol intake and thinness substantially increased the likelihood of fracture. The low weight women consuming more than one drink per day comprised but 4 per cent of our population of middle-class women and sustained 6 per cent of the fractures.

Adult↗
PubMed1986

Benefits of experience. Treating coronary artery disease.

The authors examined the issue of learning by doing in terms of both the cost and outcome of treating coronary artery disease at one hospital between 1977 and 1981. Over time, the quality of outcome improved for both medical and surgical patients. During this time of cost-plus reimbursement, there was less conclusive evidence of concurrent technical efficiency gains. These findings are consistent with the hypothesis that the benefits of experience can be substantial but they do not just happen: they require proper provider motivation.

Boston↗