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Biomedical subjects

T Colton

Publications and source records attributed to T Colton.

At least 73 records · Page 4Linked to original sources

Thyroid function after mantle irradiation in Hodgkin's disease.

We studied the thyroid function of 64 patients with Hodgkin's disease who received mantle irradiation during the period 1966 to 1976. More than two thirds (44 of 64) had some thyroid dysfunction. Twenty had mild dysfunction manifested by an abnormal thyroid-stimulating hormone response to thyrotropin-releasing hormone. Twenty had what could be termed compensated hypothyroidism while four were overtly hypothyroid. The severity of dysfunction was not related to age, sex, or chemotherapy. We found, however, that decreased thyroid function was inversely proportional to the length of time between a diagnostic lymphangiogram and the radiation therapy. These results are consistent with the hypothesis that the iodine load of the lymphangiogram renders the thyroid gland more radiosensitive. Thyroxine suppression of the thyroid gland during the period from the lymphangiogram through the termination of radiation therapy is suggested as a means of avoiding thyroid injury.

Ethiodized Oil↗

Attempts to enhance light microscopic diagnosis of cutaneous T-cell lymphoma (mycosis fungoides).

Precise pathologic criteria for the diagnosis of mycosis fungoides (MF) remain controversial. With the use of a specific counting technique and defined criteria for cell types, we attempted to differentiate between a series of slides from patients with eczematous dermatitis, large plaque parapsoriasis, and atypical dermatitis with features that suggest MF, the plaque stage of MF, and the tumor stage of MF. This could not be done on the basis of cellular density in e defined field in the papillary dermis or on the basis of the percentage of atypical lymphocytes in the fields counted. Furthermore, individual investigator variance was shown to be highly significant despite efforts to minimize this factor.

Cell Count↗

Fertility and outcome of pregnancy in women exposed in utero to diethylstilbestrol.

Fertility and outcome of pregnancy were examined in women participating in the National Cooperative Diethylstilbestrol Adenosis (DESAD) Project. We compared 618 subjects who had prenatal exposure to DES with 618 control subjects. Fertility, measured in terms of pregnancies achieved, did not differ between the women exposed to DES and the controls. An increased risk of unfavorable outcome of pregnancy was associated with DES exposure (the relative risk of any unfavorable outcome of pregnancy was 1.69; P less than 0.001). Speculation on biologic mechanisms that might produce this difference is premature, since additional data about these subjects must be collected. Among DES-exposed women who became pregnant, 81 per cent had at least one full-term live birth.

Abnormalities, Drug-Induced↗

Mortality from leukaemia and cancer in shipyard nuclear workers.

A review of death certificates in New Hampshire, Maine, and Massachusetts for 1959-77 yielded a total of 1722 deaths among former workers at the Portsmouth Naval Shipyard where nuclear submarines are repaired and refuelled. Next of kin were contacted for 592. All deaths under age 80 were classified as being in former nuclear or non-nuclear workers depending on information supplied by next of kin. With U.S. age-specific proportional cancer mortality for White males as a standard, the observed/expected ratio of leukaemia deaths was 5.62 (6 observed, 1.1 expected) among the 146 former nuclear workers. For all cancer deaths, this ratio was 1.78. Among non-nuclear workers there was no statistically significant increase in proportional mortality from either leukaemia or from all cancers. The excess proportional leukaemia and cancer mortality among nuclear workers exceeds predictions based on previous data of radiation effects in man.

Aged↗

Surgeons in the United States. Practice characteristics.

Data on practice characteristics were obtained as part of a national questionnaire study of surgeons in the United States. These included location and organization of surgeons' practices, use of nonphysician personnel, provision of ambulatory care, other professional activities, and variables associated with work load volume. A multivariate analysis was done to examine the relation between operative work loads and various practice characteristics. The variables associated with larger operative work loads were group or partnership practice, principal office not in a hospital, more nonphysician assistants in direct contact with patients, more hospitals in which operations were regularly done, and smaller proportions of nonsurgical patients. Group or partnership practice and nonsurgical practice were found to be most strongly related to operative work load.

Ambulatory Care↗

Prevalence of senile cataract, diabetic retinopathy, senile macular degeneration, and open-angle glaucoma in the Framingham eye study.

Of the Framingham, Massachusetts Heart Study population, 2,675 individuals underwent an ophthalmologic evaluation that stressed detection of senile cataract, diabetic retinopathy, open-angle glaucoma, and senile macular degeneration. Those examined were 52 to 85 years old at the time this study was initiated. The prevalence rate of each of these ocular conditions increased with age. Prevalence of senile cataracts ranged from 4.6% for those between the ages of 52 to 64 years to 46% for those 75 to 85 years of age. Diabetic retinopathy was present in 2% of those between 52 and 64 years of age or older. Overall prevalence of senile macular degeneration was 9%, with a prevalence rate of 2% in our youngest age group and 28% in the oldest age group. Open-angle glaucoma had an overall prevalence of approximately 3%. This disease also showed a statistically significant (P less than .01) increase with age from 1.4% (52 to 64 years old) to 7.2% (75 to 85 years old).

Aged↗

Comparison of luteolytic potencies of aminoglutethimide enantiomers in the rabbit and rat.

The luteolytic potency of D- and L-aminoglutethimide (D- and L-AG) was compared in in vivo assays in the rat and rabbit. By assay of plasma progesterone depletion in the rabbit, the potency of L-AG relative to D-AG was 0.21. By the plasma procedure in the rat, the relative potencies of L-AG and of the racemic mixture to D-AG were 0.04 and 0.37, respectively. By the ovarian progesterone depletion method, the L-form had very little activity and the DL-mixture was half as active as the D-isomer. Thus, in both species, almost all of the activity of the racemic mixture results from the content of D-AG. Interpretation of paradoxical data implies that in the rat, L-AG may inhibit liver degradation of progesterone at levels which do not modify secretion from the corpus luteum.

Aminoglutethimide↗

Age-incidence and risk of diethylstilbestrol-related clear cell adenocarcinoma of the vagina and cervix.

This study was based on cases accessioned in the Registry of Clear Cell Adenocarcinoma of the Genital Tract in Young Females to ascertain the incidence of diethylstilbestrol (DES)-related cancers by age and year of birth. For accuracy in estimating the size of the reference population for the incidence rates, calculations were restricted to 127 white residents of the United States who were exposed prenatally to DES or other nonsteroidal synthetic estrogens. The disease is exceedingly rare prior to age 14 when the incidence rate begins to rise rapidly. The incidence peaks at age 19 (median 19.2 years) and then drops precipitately. Thus, DES-related clear cell adenocarcinoma is unusual in that nearly all cancers have been diagnosed in a narrow age range of 10 years (14 to 23 years). Women born in 1951 to 1953 have higher incidence rates than those born in the previous or subsequent three-year period. This suggests that the prevalence of pregnancy-related use of DES was at a peak in the early 1950's. The cumulative risk of this type of genital cancer, through age 24, for DES-exposed female subjects is estimated to be in the range of 0.14 to 1.4 per thousand. The wide limits are due to the fact that the number of young women exposed is not known precisly. The low risk of disease and the narrow age range of the cases, relative to the long latency period, suggest that DES is an incomplete carcinogen. Other factors, possibly related to puberty, may be involved in the causation of this disease.

Adenocarcinoma↗

The Framingham Eye Study. I. Outline and major prevalence findings.

During the period 1973--1975, 2675 out of 3977 still-living members of the Framingham, Massachusetts, study population, who have been under investigation for coronary disease risk factors since 1948 and who were in 1973--1975 aged 52 to 85, were given an eye examination stressing cataract, diabetic retinopathy, macular degeneration and glaucoma. Of 2940 subjects who still lived in the local Framingham area, 2477 were examined. Local population prevalence for one or both eyes positive was: 15.5% for senile cataract, 3.1% for diabetic retinopathy, 8.8% for senile macular degeneration and 3.3% for open-angle glaucoma. The proportion of adults with poor "best" visual acuity may be much less than has been estimated by the National Health Survey and the proportion with open-angle glaucoma much more than currently suspected on the basis of foreign studies.

Age Factors↗

The Framingham Eye Study. II. Association of ophthalmic pathology with single variables previously measured in the Framingham Heart Study.

Using the age-sex-specific data collected in the Framingham Heart Study 1948--1964 together with ophthalmic diagnoses made in the Framingham Eye Study in 1973--1975, the following variables were found to be associated with senile cataract: education, casual blood sugar, systemic blood pressure, height, vital capacity, serum phospholipid and hand strength; with senile macular degeneration: systemic blood pressure, height, vital capacity, left ventricular hypertrophy, hand strength and history of lung infection; with diabetic retinopathy: casual blood sugar, urine sugar and other specific elements of diabetes; with ocular hypertension: systemic blood pressure, height, casual blood sugar and pulse rate. No variables were identified as associated with open-angle glaucoma. The paper stresses the need for corroboration of these findings, which may be a mix of real and chance associations, and the need for additional analyses before any of these associations are considered evidence of factors related to risk of ophthalmic disease.

Aged↗

Quality of care and unnecessary operations: a comment on The Condition of Surgery.

Issues of quality of surgical care and unnecessary operations are complex, and they will require more objective and clinically based investigations before reasonable economic judgements can be made. SOSSUS did not shy away from these questions; rather, it kept to its assigned task of describing the distribution and workloads of physicians.

Clinical Competence↗

Doctors who perform operations. A study on in-hospital surgery in four diverse geographic areas (first of two parts).

The generous supply of surgeons in the United States stimulated a study of their operative work based on all operations performed by all physicians in hospitals of four geographic areas. Each operation was assigned a California Relative Value to permit work-load comparisons between specialties and practices. General practitioners constituted more than one quarter of physicians who performed operations but accounted for less than one tenth of total work. Surgical specialists, about half the physicians in the study, performed about 80 per cent of total operative work. Work loads of surgical specialists varied by certification, specialty, age and practice organization status. We conclude that far too many physicians perform surgical operations and that work loads of surgical specialists are modest. Calculations involving reallocation of operative work loads suggest that the total volume of operations in this study could have been handled by a substantially smaller cadre of busier surgical specialists.

Certification↗

Surgeons in the United States. Activities, output and income.

In a national surgical manpower questionnaire survey, 76% of those MD and DO surgeons who were contactable returned questionnaires that included a log diary reporting details of their daily activities. Comparisons were made of allocation of professional time, number of operations performed, and net income of respondents by physician classification (including certification), specialty, practice arrangement, age, and census division. The mean professional workweek was estimated at 46 hours for all respondents. More than two thirds of the total professional time was spent in direct patient care; about half the surgeon's time was spent in the hospital, with nearly 20% in the operating room. The median annual work load of respondents was 170 operations. Their median annual net income was $45,700.

Adult↗

An inventory of biostatistics teaching in American and Canadian Medical Schools.

During the academic year 1969-70 a detailed inventory was conducted of biostatistics teaching in American and Canadian medical schools. Approximately two-thirds of schools required a separate, distinct biostatistics course. This report describes these courses, their content, and the characteristics of the individuals who taught the courses and their perception of the medical student's reaction to biostatistics. A more recent survey covering the academic year 1973-74 revealed that the situation had not changed; slightly more than two-thirds of respondents indicated that exposure to biostatistics was required in their schools' curricula.

Attitude↗