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Biomedical subjects

D Hoel

Publications and source records attributed to D Hoel.

At least 19 recordsLinked to original sources
PubMed2000

Racial, age, and rural/urban disparity in cervical cancer incidence.

PURPOSE: High mortality rates of cervical cancer among black women have been observed for several decades in the Southeast. The purpose of this study is to assess the factors associated with this geographic and racial enigma, and to see if incidence is consistent with mortality.METHODS: Using the Savannah River Regional Health Information System (SRRHIS), a 5-year cancer registry from 1991-1995, incidence rates were calculated and compared to rates from Surveillance, Epidemiology, and End Results (SEER). The rates per 100,000/year were analyzed by race, rural/nonrural, and age (<45 and >/=45).Rates are similar between SRRHIS and SEER except in the case of black women over the age of 45. These women in rural SRRHIS have 1.66 times the incidence rate compared to those in nonrural SRRHIS and 1.97 times the rate of rural SEER.RESULTS:Table 1CONCLUSIONS: The results of the study suggest that the incidence of cervical cancer in the region is consistent with the mortality rates. The age-group with the highest rates are black women over 45 in rural areas, suggesting the need to target this group to reduce the racial disparity in cervical cancer.

Journal Article↗
PubMed2000

Geographic patterns of pulmonary disease in south carolina.

PURPOSE: The purpose of this study is to assess the patterns of geographic variation of the following pulmonary diseases: tuberculosis (TB), lung cancer (LC), berylliosis (BR), sarcoidosis (SR), and asthma (AS).METHODS: Hospitalization rates for the five diseases were calculated for the 46 South Carolina (SC) counties from 1985-1995. Variation in rates was assessed by county, region, and urban/rural status using analysis of variance. SC was divided into 4 regions, according to proximity to the coastline and to physiographic characteristics. Region 1 comprised counties in the western-most part of the state, and region 4 comprised the counties closest to the coastline. SC was also divided into 5 population density settings: extreme rural (<15,000), rural (15,000-30,000), middle-size (30,000-50,000), middle-urban (50,000-100,000) and urban (>100,000). Statistical analyses were performed with SAS Version 8.RESULTS:Table 1The rates of SR, TB, and BR were significantly higher in the coastal region. In contrast, no coastal pattern was detected by population density.CONCLUSIONS: The consistent association of SR, TB, and BR with geographical region, as opposed to the inconsistent association with population density, suggests that environmental factors may be involved in these pulmonary diseases. These results demonstrate the need for further analysis of the relationship between socio-economic, behavioral, and environmental factors and the development of these diseases.

Journal Article↗
PubMed2000

Possible relationship between birth weight and cancer incidence among young adults.

PURPOSE: Fetal and early life events have been associated with diseases that develop later in life. Low birth weight and the adult onset of hypertension, coronary heart disease, cerebrovascular disease, and non-insulin dependent diabetes have been identified. As well, associations with breast, ovarian, and prostate cancer to high birth weight have been found. An assessment of birth weight and cancer incidence was conducted in a cohort of black and white residents under the age of 46 years.METHODS: Cases were obtained from the Savannah River Region Health Information System cancer registry incident cases (1991-1995) and were limited to South Carolinians born in 1950 and later. Controls were obtained from birth certificate records by choosing the next two records after a cancer case record that matched on year of birth, race, and sex. Results were obtained for 117 cancer cases and 238 controls.RESULTS: After examining the birth distribution, the births were split into two groups based on mean birth weight among controls (3215 grams). Conditional logistic regression (CLR) showed that individuals with higher birth weights (> = 3215 g) were 1.65 (95% CI = 1.03-2.64) times more likely to be cancer cases than those with lower birth weights. When weights were categorized into 500 g increments, a CLR Score statistic showed there was a significant trend (p = 0.0006) of increasing proportion of cancer cases with increasing birth weight. Eight out of the eight cases of lymphoma had birth weights greater than 3579 g.CONCLUSIONS: The results of this preliminary study suggest that cancer incidence among the young may be associated with higher birth weights. One possible reason for this finding, which requires further investigation, might be that larger infants are exposed to higher levels of hormones and/or growth factor than smaller infants in utero that might increase the risk of certain cancers later in life. This may be suggestive of possible environmental factors affecting early growth. These findings support the need for additional study of this association.

Journal Article↗
PubMed2000

Magnetic field exposure of commercial airline pilots.

PURPOSE: Airline pilots are exposed to magnetic fields generated by the aircraft's electrical and electronic systems. The purpose of this study was to directly measure the flight deck magnetic fields to which commercial airline pilots are exposed when flying on different aircraft types over a 75-hour flight-duty month.METHODS: Magentic field measurements were taken using personal dosimeters capable of measuring magnetic fields in the 40-800 Hz frequency range. Dosimeters were carried by either the Captain or the First Officer on Boeing 737/200, Boeing 747/400, Boeing 767/300ER, and Airbus 320 aircraft. The data were analyzed by aircraft type, with statistics based on block hours. Block hours begin when the aircraft departs the gate prior to take off and end when the aircraft returns to the gate after landing.RESULTS: Approximately 1008 block hours were recorded at a sampling rate of 3 seconds. Total block time exposure to the pilots ranged from a harmonic geometric mean of 6.7 milliGauss (mG) for the Boeing 767/300ER to 12.7 mG for the Boeing 737/200.CONCLUSIONS: Measured flight deck magnetic field levels were substantially above the 0.8 to 1 mG level typically found in the home or office and suggest the need for further study to evaluate potential health effects of long-term exposure.

Journal Article↗
PubMed1999

Leukaemia in the vicinity of two tritium-releasing nuclear facilities: a comparison of the Kruemmel Site, Germany, and the Savannah River Site, South Carolina, USA.

In 1991, an increased rate of childhood leukaemia was reported from the small northern German community of Elbmarsch, which is located on the banks of the River Elbe opposite the Kruemmel nuclear power plant. Owing to the fact that the increase occurred six years after the start-up of the plant, radioactive discharges were suspected as being implicated in the development of the cases. Previous investigations have failed to identify any exposure which might be associated with the cluster. Nonetheless, concern regarding the increased tritium burden in the environment remains. To further assess the impact of tritium releases to the environment upon population cancer rates, the releases and leukaemia rates at the Savannah River site, USA, were compared with the Kruemmel site. Based on the data from 1991 to 1995, the incidence of childhood leukaemia in the vicinity of the Savannah River site was non-significantly less than expected compared with the significantly higher than expected rates close to the German plant. In contrast, tritium releases from the Savannah River site exceed those from the Kruemmel site by several orders of magnitude. The results of this observational study suggest that factors other than environmental tritium releases are associated with the increased number of leukaemia cases near the Kruemmel site.

Child↗
PubMed1999

Knee replacement.

Explore the source record for details and available documents.

Arthroplasty, Replacement, Knee↗
PubMed1997

Raising the curtain on cancer. Is the puzzle finally becoming clear?

Looking back at the long history of cancer, we can still relate to that POSTGRADUATE MEDICINE editorial written 50 years ago: "None of the basic problems of cancer has been solved. The death rate is constantly mounting. Small wonder that many doctors face cancer with a pessimism bordering on resignation." The temptation is still to prepare for the worst. Nonetheless, cautious optimism is evident among cancer researchers. As Eugenie Kleinerman, a pediatric oncologist at M.D. Anderson Cancer Center in Houston, recently explained, "We're running a marathon, not a sprint. What's important is not how fast we run the first two miles but when we cross the finish line." In many ways, cancer is still a derogatory word used figuratively in reference to uncontrolled evil. But progress against this common disease is real, as evidenced by the growing population of long-term survivors. New discoveries are expanding therapeutic options every year. The challenge continues to be educating health professionals and patients alike about environmental risks and warning signs, recognizing cancer early, and finding more effective and less toxic therapies. In addition, we need to learn about the prevention, detection, and treatment of late effects of long-term survivors. The curtain is rising on a new era of cancer management, and we all have fron-row seats.

Egypt↗
PubMed1993

Ligand/receptor binding for 2,3,7,8-TCDD: implications for risk assessment.

There is renewed controversy regarding safe exposure levels for dioxin. At the heart of this controversy is the hypothesis that toxic effects of dioxin are receptor-mediated and therefore a "threshold" should exist below which no toxic effects can occur. Our research focuses on the ability of dioxin to alter protein levels in rodent livers. Established effects of exposure to dioxin are the induction of cytochrome P450-1A1 and P450-1A2 and a reduction in the maximal binding of the epidermal growth factor receptor in rat livers. An initiation-promotion protocol was used to study the effects of dioxin in female Sprague-Dawley rats. Animals were administered a single initiating dose of diethylnitrosamine followed by 16 biweekly gavage doses of 2,3,7,8-TCDD. Steady-state pharmacodynamic models were fit to these data assuming a combination of Hill kinetics and Michaelis-Menten kinetics. Two classes of models were developed which postulate two different mechanisms for the constitutive expression and TCDD-induced alterations in the levels of these proteins. The results are consistent with models which follow proportionate response in the low-dose region (no threshold) and with models which allow for a low-dose threshold. In all cases studied, the best fitting model exhibited no "threshold" for the effects of TCDD on the modulation of these proteins. The finding is consistent with the knowledge that for some receptor-mediated responses, there is a proportional relationship between receptor occupancy and biological response, even at low ligand concentrations.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1992

Perspective and overview of the concepts and value of hazard identification as the initial phase of risk assessment for cancer and human health.

The identification of potential human health hazards stems from the obvious need to prevent, avoid, reduce, and eliminate exposure to hazardous agents, mixtures of agents, or exposure circumstances. The first step in the risk assessment process centers on determining if a hazard exists. The following strategies are used for this purpose: (i) epidemiologic investigations, (ii) long-term chemical toxicology and carcinogenesis studies on laboratory animals, (ii) shorter-term in vivo and in vitro assays, and (iv) physicochemical structure-activity relationships. Indicator 1 is the most relevant and reliable if adequate data are available; indicator 2 is the most valid and useful alternative for human experience; indicator 3 allows certain toxicologic end points to be identified, but generally needs confirmatory and supportive information; and indicator 4 has made gains in the area of predictivity. The advantages and limitations of each are given. The magnitude of the overall cancer hazard identification effort and a likelihood number of eventual chemical carcinogens have also been estimated.

Animals↗
PubMed1991

Is brain cancer mortality increasing in industrial countries?

This paper analyzes age-specific trends in brain and other central nervous system cancer mortality from 1968 to 1987 in several major industrial countries. It also examines changes in the use of diagnostic confirmation technology and trends in incidence in the U.S. National Cancer Institute, Surveillance, Epidemiology, and End Results (SEER) program from 1973 to 1987 to estimate the influence of diagnostic factors on recent mortality trends. Other sources of error have not been evaluated in this paper. Age-specific analyses of brain and other nervous system cancer mortality show drastic increases in persons ages 75-84 and consistent increases in younger age groups in most countries, although mortality declined in the U.S. in persons 0-24 by 2% annually. In the SEER program, brain cancer incidence increased significantly by 2%, 1%, and 5% annually in persons aged 0-44, 65-74, and 75-84, respectively. Throughout this time period, microscopic or radiographic confirmation occurred in at least 96% of all incident cases of brain and other central nervous system cancers diagnosed before death, with older persons receiving consistently more radiographic tests than younger persons. Changes in diagnoses across populations and over time are unlikely to account completely for these increasing trends which are occurring simultaneously in both males and females in major industrial countries. Additional studies need to be conducted, to exclude artifacts, to assist health care planners in anticipating treatment demands, and to detect preventable causes of these changing trends.

Adult↗