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Biomedical subjects

C D Boysen

Publications and source records attributed to C D Boysen.

9 recordsLinked to original sources
PubMed2000

Increased lymphocyte replicative index following 2,4-dichlorophenoxyacetic acid herbicide exposure.

OBJECTIVE: Evaluate peripheral blood lymphocyte proliferation (replicative index:RI) and micronuclei frequency (MF) among 2,4-D herbicide applicators. METHODS: Twelve applicators spraying only 2,4-D provided a blood and urine specimen upon enrollment, several urine samples during the spraying season, and a blood specimen at the study's end. Nine controls provided blood and urine specimens upon enrollment and at the study's end. Gas chromatography/tandem mass spectroscopy determined urinary 2,4-D levels and standard in-vitro assays determined RI and MF scores. Applicator RI and MF were compared before and after spraying and with controls. RESULTS: Applicators contributed 45 urine specimens with concentrations ranging from 1.0 to 1700 (microg 2,4-D/g creatinine/L urine) that logarithmically (In) increased as spraying time increased. Applicator RI increased after spraying (p = 0.016), independent of tobacco and alcohol use, and demonstrated a weak dose-response with increasing urinary 2,4-D levels (p = 0.15). Among 2,4-D applicators, pre-exposure complete blood counts and lymphocyte immunophenotypes were not significantly different from post-exposure measurements. CONCLUSION: Urinary 2,4-D concentration, an exposure biomarker, may be associated with lymphocyte replicative index, a cell proliferation biomarker.

2,4-Dichlorophenoxyacetic Acid↗
PubMed1999

An analysis of the suitability of home health visits for telemedicine.

To determine what percentage of traditional home health nursing visits could be done by telemedicine, we carried out a retrospective review of nursing charts (clinical records). Data of two types were recorded. The objective data, which were abstracted from the records, included demographic information, patient assessments, teaching activities and interventions. The subjective data were the opinions of four observers as to whether the visit could have been done using currently available telemedicine technology. Records were sampled randomly for patients who had received home nursing care from three home health agencies in rural and urban areas during the winter and summer of 1996. A 54-item coding instrument was applied to 906 different charted home nursing visits. For 412 (46%) of these, the on-site nursing could reasonably have been replaced by telenursing. Significant factors determining the possible use of telenursing included primary diagnosis, number of interventions and patient age. Among the 10 most common primary diagnoses, the most amenable to telenursing care were chronic airway obstruction and joint disorders; the least amenable were coagulation disorders and anaemia. Telenursing visits could substitute for a substantial fraction of on-site home nursing visits. This has important implications in terms of reducing the cost of home nursing care.

Feasibility Studies↗
PubMed1999

Very long survival in pediatric cancer between 1944 and 1993.

OBJECTIVE: To identify factors associated with very long survival among all cancer cases diagnosed at age 19 years or younger registered by the Cancer Data Service at the University of Kansas Medical Center in Kansas City, Kansas, U.S.A. in the 40-year period between 1944 and 1983, with follow-up to 1993. METHODS: There were 2720 pediatric patients with 2750 cancers who were studied. Forty-four types of cancer were grouped into 11 diagnostic categories. Diagnosis years spanned four eras: 1944-1953, 1954-1963, 1964-1973, and 1974-1983. Cases were compared using specific characteristics and were divided into short-term and long-term survivors with the division generously set at seven years. The proportions of the long-term survivors were compared by specific characteristics. RESULTS: Among the diagnostic categories, leukemias were the most common (29.8%), followed by CNS tumors (15.2%), and Hodgkin's disease (9.0%). Male to female ratio was 4:3; average age at diagnosis was 8.83 +/- 6.08 years. Long-term survivors totaled 1148 (41.7%). Prognosis was better in cases diagnosed in earlier stages and in later eras. Proportion of long-term survivors increased from 18.7% in era I to 52.6% in era IV. Improvement of survival was statistically significant in most diagnostic categories. CONCLUSIONS: This study shows continuing improvement of survival during four consecutive eras for childhood and adolescent cancer. Early diagnosis was associated with better survival. Unstaged cases decreased over time reflecting progress in diagnostic techniques. Many patients died before seven years after diagnosis. Those who survived more than seven years had excellent survival. Pediatricians can expect to participate in the care of these patients long after the original dianosis and treatment.

Child↗
PubMed1998

A cost measurement study for a tele-oncology practice.

The costs of providing oncology services in three different ways were measured. Services were provided to a peripheral hospital by: conventional clinics, in which the oncologist worked at the hospital concerned; outreach clinics, in which an oncologist was flown in periodically from a central hospital; telemedicine clinics, in which the oncologist at the central hospital practised via a video-link. During a one-year study period, 2400 patients were seen in conventional clinics, 81 in outreach clinics and 103 in telemedicine clinics. At these workloads the average costs per patient were $149, $897 and $812, respectively. However, the average costs cannot be compared directly without further information about the shape of the unit cost curves.

Cost-Benefit Analysis↗
PubMed1997

A cost analysis of a tele-oncology practice.

Costs were monitored for three different types of oncology practice: a telemedicine clinic and a fly-in outreach clinic, both held in rural areas, and a traditional clinic held in a city hospital. Total expenses were calculated over the year May 1995 to April 1996. The average cost per telemedicine visit was $812. The average cost per outreach clinic visit was $897. Flying in oncology support for this practice was therefore about 10% more costly than telemedicine. While the outreach cost may have been inappropriately high due to a slow start-up phase, it was still less expensive during this period to be seen via telemedicine. For comparison, the average cost per traditional oncology clinic visit was $149. However, this figure does not take into account the costs of access to a city-based service by rural patients.

Cost-Benefit Analysis↗
PubMed1989

A case-control study of soft-tissue sarcoma.

The roles of nonagricultural occupations, tobacco use, beverage consumption, medical history, and other factors in the development of soft-tissue sarcoma were examined in a population-based case-control study in Kansas. Based on 133 cases diagnosed between 1976-1982 and 948 controls, there were significant excesses associated with use of the drug chloramphenicol (odds ratio (OR) = 5.4, 95% confidence interval (Cl) 1.2-23.9) and chewing tobacco or snuff (OR = 1.8, 95% Cl 1.1-2.9). The risk associated with smokeless tobacco varied with the location of the tumors; greater risks were observed for tumors of the upper gastrointestinal tract (OR = 3.3), the lung, pleura, and thorax (OR = 3.1), and the head, neck, and face region (OR = 2.4) than other regions of the body (OR = 1.4). A nonsignificant excess was seen with the use of cholesterol-lowering drugs, such as clofibrate (OR = 1.7). Four cases reported histories of prior radiation treatment to the same area of their bodies as their tumors. Soft-tissue sarcoma was also associated with employment in woodworking occupations (OR = 1.7, 95% Cl 0.9-3.2) and risk increased with increasing duration of employment. Persons with first-degree blood relatives with a history of Hodgkin's disease, lymphoma, or cancers of the pancreas, prostate, brain, or skin were at increased risk. Many of the associations observed in this study, notably the risk of soft-tissue sarcoma with smokeless tobacco and medications such as chloramphenicol, deserve further evaluation.

Adult↗
PubMed1988

A case-referent study of soft-tissue sarcoma and Hodgkin's disease. Farming and insecticide use.

A population-based case-referent study in Kansas examined the relationship between exposure to insecticides and the development of soft-tissue sarcoma (STS) and Hodgkin's disease (HD). Data from telephone interviews for 133 STS cases, 121 HD cases, and 948 referents indicated that STS was associated with use of insecticides on animals, but not on crops. HD was not significantly associated with either use. STS risk was higher among the farmers who themselves mixed or applied insecticides to animals than among farmers who did not. Farmers who failed to use any protective equipment to reduce insecticide exposure were at a significantly elevated risk of STS. Risk rose with early calendar year of first use. The excess risk appeared to be primarily among fibrous and myomatous sarcomas with little association seen for lipomatous or other STS neoplasms. Myomatous sarcomas increased significantly with duration and time since first use of insecticides on animals. If the reported association between STS and insecticides is causal, the data suggest that exposure to the agent(s) responsible may have been reduced in the mid-1950s or the agent(s) have an average latency period for STS of at least 20 years.

Aged↗
PubMed1986

Agricultural herbicide use and risk of lymphoma and soft-tissue sarcoma.

A population-based case-control study of soft-tissue sarcoma (STS), Hodgkin's disease (HD), and non-Hodgkin's lymphoma (NHL) in Kansas found farm herbicide use to be associated with NHL (odds ratio [OR], 1.6; 95% confidence interval [CI], 0.9, 2.6). Relative risk of NHL increased significantly with number of days of herbicide exposure per year and latency. Men exposed to herbicides more than 20 days per year had a sixfold increased risk of NHL (OR, 6.0; 95% CI, 1.9, 19.5) relative to nonfarmers. Frequent users who mixed or applied the herbicides themselves had an OR of 8.0 (95% CI, 2.3, 27.9) for NHL. Excesses were associated with use of phenoxyacetic acid herbicides, specifically 2,4-dichlorophenoxyacetic acid. Neither STS nor HD was associated with pesticide exposure. This study confirms the reports from Sweden and several US states that NHL is associated with farm herbicide use, especially phenoxyacetic acids. It does not confirm the case-control studies or the cohort studies of pesticide manufacturers and Vietnam veterans linking herbicides to STS or HD.

Adult↗