Biomedical subjects

T R Fears

Publications and source records attributed to T R Fears.

60 records · Page 4Linked to original sources

PubMed1976

Skin cancer, melanoma, and sunlight.

Recent theoretical studies suggest that the earth's ozone layer which filters ultraviolet radiation may be depleted by a fleet of supersonic transports or by continued use of chlorofluoromethanes. It is now generally accepted that short wavelength ultraviolet radiation leads to the development of skin cancer. In this report we demonstrate an approach to estimating the increase in skin cancer incidence associated with increases in skin cancer incidence associated with increases in ultraviolet radiation. The purpose is to demonstrate the logic used and the assumptions that must be made when such estiamtes are made or cited. We emphasize that such estimates should be considered crude until the many assumptions can be investigated.

Environmental Exposure↗

PubMedDate not supplied

Late effects of therapy in survivors of Ewing's sarcoma family tumors.

PURPOSE: This late effects study was designed to determine if survivors of Ewing's sarcoma family tumors (ESFT) had adverse outcomes in employment, marital status, fertility, and functional status when compared to sibling controls. SUBJECTS AND METHODS: Eighty-nine survivors (case subjects) of ESFT treated at the National Cancer Institute between 1965 and 1992 and 97 sibling controls completed a questionnaire probing aspects of quality of life. The answers from case subjects were compared to pooled and matched sibling controls for all key variables. Odds ratios (OR) and p values from pooled analyses are presented. RESULTS: Although case subjects and controls did not differ in educational achievement, case subjects were less likely to be employed full-time (OR 0.4, p < 0.01), to be married (OR 0.2, p < 0.01), and to have children (OR 0.3, p < 0.01). Their most common treatment-related difficulties included permanent hair and skin changes (43%), lung problems (18%), neurologic problems (14%), visual difficulties (10%), second malignancy (7%), and amputation (5%). Functional status, measured by Karnofsky performance scale, was also adversely affected in case subjects. Case subjects did not differ from sibling controls in health care insurance status or in utilization of health services. CONCLUSIONS: Important aspects of life such as employment, marital status, fertility, and functional status are affected in survivors of ESFT. More studies are needed to better define the health status of adult survivors of pediatric cancer and the impact of cancer in adolescence on psychosocial development.

Adolescent↗

PubMedDate not supplied

Increased risk of secondary leukemia after single-agent treatment with etoposide for Langerhans' cell histiocytosis.

The study evaluated 139 patients diagnosed with Langerhans' cell histiocytosis (LCH) and enrolled in any protocol of the Italian Association of Pediatric Hematology/Oncology since 1982. Treatment was etoposide (VP-16) only in 50 patients, VP-16 and other drugs with an already established leukemogenic effect in 17 patients, only drugs with leukemogenic effect in 6 patients, other drugs in 35 patients, and surgery only in 31 patients. Median length of follow-up after diagnosis was 65 months (range, 1 to 126 months) for a total of 742.5 person-years at risk (PYRs). Three cases of acute myelogenous leukemia (AML) were reported; only 0.0044 case was expected. The standard incidence ratio (SIR) of AML in this cohort was 680.5 [95% confidence interval (CI), 140.2-1988.5], and the incidence rate per 1000 PYRs was 4.0 (95% CI, 0.8-11.8). For the subgroup treated with single-agent VP-16, the SIR after treatment was 2270.0 (95% CI, 275-8199), and the incidence rate after treatment was 14.7 (95% CI, 1.8-42.8). The study confirms a higher risk of leukemia after LCH and supports the hypothesis of an association between treatment-related acute nonlymphocytic leukemia and single-agent treatment with VP-16.

Antineoplastic Combined Chemotherapy Protocols↗

PubMedDate not supplied

Population-based monitoring of an urban HIV/AIDS epidemic. Magnitude and trends in the District of Columbia.

OBJECTIVE: To assess the extent of the human immunodeficiency virus (HIV)/acquired immunodeficiency syndrome (AIDS) epidemic in the District of Columbia and demonstrate an approach to monitoring HIV infection and projecting AIDS incidence at a community level. DESIGN: Backcalculation methods to reconstruct HIV incidence from AIDS incidence in subgroups. Results were compared with directly measured HIV seroprevalence in selected sentinel populations: childbearing women, civilian applicants for military service, and hospital patients admitted for conditions unrelated to HIV infection. RESULTS: Between the start of the epidemic in 1980 and January 1, 1991, one in 57 District of Columbia men aged 20 to 64 years was diagnosed with AIDS. Unlike the plateau projected for the nation, AIDS incidence for the District of Columbia was projected to increase by 34% between 1990 and 1994. Models of HIV infection incidence suggested two broad epidemic waves of approximately equal size. The first occurred in men who have sex with men and peaked during the period from 1982 through 1983. The second began in the mid-1980s in injecting drug users and heterosexuals. We estimated that among District of Columbia residents aged 20 to 64 years, 0.3% of white women, 2.9% of white men, 1.6% of black women, and 4.9% of black men were living with HIV infection as of January 1, 1991. These estimates are broadly consistent with survey data: among black childbearing women in their 20s, HIV prevalence doubled to 2% between the fall of 1989 and the spring of 1991; from military applicant data, we estimated that over 5% of black men born from 1951 through 1967 were HIV-positive; in the sentinel hospital, HIV prevalence rates among male patients aged 25 to 34 years were 11.3% in white men and 16.9% in black men. CONCLUSION: Backcalculation and surveys yielded quantitatively consistent estimates of HIV prevalence. Many injecting drug users and heterosexuals in the District of Columbia were infected after January 1, 1986. Similar monitoring of the epidemic in other localities is needed to focus efforts to reduce the incidence of HIV transmission.

Acquired Immunodeficiency Syndrome↗

PubMedDate not supplied

Suggested procedures for reducing the pathology workload in a carcinogen bioassay program, Part I.

Large test programs have been set up to help assess the carcinogenic potential of chemicals introduced into the environment. Most test protocols used in these programs require large numbers of animals and extensive pathologic evaluation of all test and control animals. In this paper we describe modifications to the present pathology protocol which will reduce the pathology workload of the program and make only small changes in the operational character of the screen. The first modification derives from the fact that a tumorigenic effect may be ruled out by looking at the treated animals only. The second procedure suggested uses simple random samples to provide information about the treated groups with still less pathology work. It is emphasized that these proposed modifications should be regarded as a starting point for further discussion and that we encourage comments from all interested scientists.

Animals↗

PubMedDate not supplied

Suggested procedures for reducing the pathology workload in a carcinogen bioassay program, Part II: Incorporating blind pathology techniques and analysis for animals with tumors.

Large testing programs have been set up to help assess the carcinogenic potential of chemicals introduced into the environment. Most test protocols used in these programs require extensive pathologic evaluations of all test and control animals. In Part I we proposed modifications to such complete pathology protocols which would allow substantial reduction in pathology workload while making only small changes in the operational character of the screen. The modifications suggested did require that slides from controls and treatment animals be handled differently and they did not call for a total tumor analysis (i.e. they do not allow blind pathology). In this paper we discuss how blind pathology can be incorporated and suggest a procedure to recover the "total tumor" aspect. It is emphasized that these modifications should be regarded as a starting point for further discussion and that we encourage comments from all interested scientists.

Animals↗