Relating influenza epidemics to childhood leukemia in tumor registries without a defined population base: a critique with suggestions for improved methods.
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Biomedical subjects
Publications and source records attributed to B S Pasternack.
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To determine the risks of reoperation and clinical recurrence in Crohn's disease involving the colon, we analyzed by both crude and actuarial (life-table) methods follow-up data from 160 patients hospitalized with Crohn's colitis or ileocolitis from 1964 through 1973. A total of 100 patients (63 per cent) underwent major operation; of these, 58 required reoperation. By the 15th year after initial operation, there was a cumulative reoperation rate of 89 and an overall clinical recurrence rate of 94 per cent. Crude data implied that the reoperation rate diminished with each succeeding operative procedure, from 58 per cent after the first operation to 47 per cent after the fourth. By contrast, actuarial analysis revealed that at the three-year follow-up point, the cumulative chance of reoperation increased from 37 per cent after the first surgical procedure to 60 per cent after the fourth. The inexorable tendency of Crohn's ileocolitis to require repeated operations is demonstrable by actuarial methods.
Chloromethyl methyl ether (CMME) has been used extensively as a crosslinking agent for ion-exchange resins. Commercial grades of CMME are contaminated to the extent of 2-8% with bischloromethyl ether, an alkylating agent which has been shown to be a very potent lung carcinogen in animals. Reports by other investigators in this and other countries have implicated CMME as a lung carcinogen in chemical workers. The purpose of the study reported here was to examine the lung cancer mortality experience with respect to intensity and duration of exposure in six of the seven chemical companies that account for virtually all of the CMME use in the United States. The study included about 1800 workers who were exposed in the period 1948 to 1972 and about 8000 workers not exposed to CMME from the same plants who served as controls. Exposed workers were characterized according to job description and duration of exposure. In several plants the intensity of exposure was numerically graded for each job category with adjustment for temporal changes in the plant processes. Social Security records were used to identify deaths among workers who had left the companies and death certificates have been obtained for virtually all known deaths. The age-adjusted death rate for respiratory cancer in the CMME exposed group as a whole was 2.5 times that in the control group, whereas death rates due to other causes were comparable. There was also a gradation of lung cancer risk according to intensity and duration of exposure and the time elapsed since the onset of exposure.
To assess the influence of coronary revascularization on the long-term survival of patients with debilitating angina and significant impairment of left ventricular function, analysis was done of 62 consecutive patients with severe angina and hypokinetic left ventricles (LVED larger than or equal to 20) undergoing coronary bypass at N.Y.U. Medical Center between January, 1971 and May 1974. Follow-up was 98% complete, range 4 to 41 months with a mean of 23 months. Multiple bypasses were done in 94% of the group; a left-ventricular scar was excised in 16%. There were six operative deaths (mortality 9.7%) and three late deaths, all within eight months after operation. Angina was either absent or substantially improved in 90% of surviving patients. Life-table analysis shows a two-year survival of 85%, very similar to the survival rate for patients with good ventricular function. Hence, with current techniques impaired ventricular function is not a major contraindication to bypass grafting.
A method of clinical staging of chronic lymphocytic leukemia (CLL) has been proposed which is based on the concept that CLL is a disease of progressive accumulation of nonfunctioning lymphocytes: stage O, bone marrow and blood lymphocytosis only; stage 1, lymphocytosis with enlarged nodes; stage II, lymphocytosis with enlarged spleen or liver or both; stage III, lymphocytosis with anemia; and stage IV:lymphocytosis with thrombocytopenia. Analysis of 125 patients. in the present series showed the following median survival times (in months) from diagnosis: stage 0, is greater than 150; stage I 101; stage II, 71; stage III, 19; stage IV, 19, The median survival for the entire series was 71 mo. The prognostic significance of the stage remained even after adjustment was made for age and sex. However, both sex and age were shown to be poor predictors of survival after adjustment for stage. The method of staging proved to be a reliable predictor of survival whether used at diagnosis or during the course of the disease. The proposed staging system was an equally accurate indicator for survival when applied to two other previously published studies of large series of patients
Exposure of Rabbits to 1.0 ppm ozone for 90 minutes results in a decrease in lung microsomal cytochrome P-450 levels.
Approximately 1,000 coronary bypass procedures were performed at New York University between February 1968 and December 1973. This report reviews all elective operations performed for angina between 1968 and 1972, a total of 448 patients. In this five-year period the percentage of diseased arteries bypassed rose from 40% to 84%, and operative mortality decreased from 28% to less than 3%. There were a total of 28 operative deaths, mostly from myocardial infarction and low cardiac output. Operability was nearly 95%. The only fixed contraindication was chronic congestive failure. Over one-half of the patients had an abnormal ventriculogram, and there was some history of mild congestive failure in nearly 20%. Elevation of left ventricular end-diastolic pressure above 20 mm before operation was associated with a higher operative mortality, but the late mortality was similar to those with a normal preoperative end-diastolic pressure. In 383 surviving patients, angina was eliminated or greatly improved in 86%, unimproved in 12% and worse in 2%. Late angiograms were performed on 201 patients, studying a total of 445 venous grafts with an overall patency rate of 71%. Graft occlusion was sporadic and unpredictable, but over 90% of patients with multiple grafts remained with at least one patent graft. A late myocardial infarction occurred in 32 out of 420 patients surviving operation, and was fatal in eight. The cumulative incidence over a period of five years was 17%. Twenty-three deaths occurred following discharge from the hospital. Life-table analyses showed a five-year survival of 77% when all deaths were included, and a five-year cardiac survival of 81% when non-cardiac deaths were withdrawn alive at the time of death. The expected survival in a comparable population group without coronary disease was 92%, while data published by Sones of patients treated without operation showed a five-year cardiac survival of 66%. Current operative techniques have an operative mortality of 2-3% and a subclinical infarction rate of 5-10%. The ideal graft is yet evolving, but data with internal mammary artery grafts are most encouraging. A future goal should be a five-year graft patency of at least 80%. Because many infarcts probably develop from a relatively small decrease in coronary blood flow, either during rest or mild activity, the likelihood that future data will demonstrate a marked increase in longevity with bypass grafting is great.
The purpose of this study is to assess the nature and magnitude of the deleterious health effects of subclinical over-exposure to lead in children. The study stems from concerns about the impact on the health of children in city slums who ingest leaded paint without overt evidence of poisoning and the health implication of rising levels of lead in the environment from automotive emissions. The study sample was derived mainly from a registry of children on whom blood lead determinations had been made by the New York City Department of Health and was supplemented by siblings of the registry cases and children from a lead belt area who had extractions of deciduous teeth in dental clinics. Information was obtained through parental interview, medical records, and psychometric evaluation. The data show that deleterious health effects occur in children who were treated for severe lead poisoning and in children without diagnosed lead poisoning who had elevated blood leads (>/=0.06 mg-%). In the absence of diagnosed lead poisoning or elevated blood leads, excess lead exposure, measured in terms of high levels of lead in teeth, was not associated with deleterious health effects.
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