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Forty-two patients who had a Porous Coated Anatomic (PCA) "E" series, second-generation, cementless hip arthroplasty (Howmedica, Rutherford, NJ) were compared with 42 patients who had a first-generation PCA prosthesis. Patients were directly matched for age, sex, diagnosis, weight, Charnley functional status, and duration of follow-up. All of the operations were done by the same two surgeons, who used the same operative approach and the same postoperative rehabilitation plan. All of the patients were followed up for at least 5 years (range, 60 to 76 months). In the "E" series group, there were 41 of 42 (98%) good and excellent clinical results with a mean Harris hip score of 94 points (range, 46 to 100 points); the first-generation group had 34 of 42 (81%) good and excellent clinical results and a mean Harris score of 81 points (range, 42 to 100 points) (P = 0.001). There was one acetabular component revision in the "E" series group (2%), which can be compared with eight revisions (19%) in the first-generation group (P = 0.012). The incidence of femoral radiolucencies was 19% (eight hips) for the "E" series group compared with 50% (21 hips) in the first-generation group (P = 0.009). The radiolucencies in the "E" series group were small, nonprogressive, and confined typically to zone I. We believe that the improvements in design of the "E" series component may account for these differences.

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An analysis was conducted of 27,982 deaths among 106,020 persons employed at four Federal nuclear plants in Oak Ridge, Tennessee, between 1943 and 1985. The main objectives were to extend the evaluation of the health effects of employment in the nuclear industry in Oak Ridge to include most workers who were omitted from earlier studies, to compare the mortality experience of workers among the facilities, to address methodological problems that occur when individuals employed at more than one facility are included in the analysis, and to conduct dose-response analyses for those individuals with potential exposure to external radiation. All-cause mortality and all-cancer mortality were in close agreement with national rates. The only notable excesses occurred for white males for lung cancer [standardized mortality ratio (SMR) = 1.18, 1,849 deaths] and non-malignant respiratory disease (SMR = 1.12, 1,568 deaths). A more detailed analysis revealed substantial differences in death rates among workers at the Oak Ridge plants. Evaluation of internally adjusted log SMRs using Poisson regression showed that workers employed only at Tennessee Eastman Corporation or K-25 and at multiple facilities had higher death rates than similar workers employed only at X-10 or Y-12, and that the differences were primarily due to non-cancer causes. Analysis of selected cancer causes for white males indicated large differences among the workers at the different facilities for lung cancer, leukemia and other lymphatic cancer. Dose-response analyses for external penetrating radiation were limited to a subcohort of 28,347 white males employed at X-10 or Y-12. Their collective recorded dose equivalent was 376 Sv. There was a strong "healthy worker effect" in this subcohort-all-cause SMR = 0.80 (4,786 deaths) and all-cancer SMR = 0.87 (1,134 deaths). Variables included in the analyses were age, birth cohort, a measure of socioeconomic status, length of employment, internal radiation exposure potential and facility. For external radiation dose with a 10-year lag, the excess relative risk was 0.31 per Sv (95% CI = -0.16, 1.01) for all causes and 1.45 per Sv (95% CI = 0.15, 3.48) for all cancer. The estimated excess relative risk for leukemia was negative but imprecisely determined. A preliminary dose adjustment procedure was developed to compensate for missing dose but not other dosimetry errors. Results of the analyses using the adjusted doses suggest that the effect of missing dose is an upward bias in dose-response coefficients and test statistics.

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Occupational monitoring data are typically in the form of air samples or biological samples. Air samples are more frequently available and often have been used to characterize personnel exposure in epidemiological studies. Air samples that are not specific to individual employees are easier and cheaper to procure than biological samples such as urinalyses. However, the correlation between concurrent air samples and urinalyses has not always been found to be strong. The purpose of this paper is to compare internal radiation doses for uranium workers estimated from air sample results with those estimated from urine sample results. The comparison was made on results associated with individuals who worked in a uranium processing and fabrication facility between 1950 and 1956. Independent lung dose estimates were made for individuals for whom both types of data were available for periods of 300-365 d. Plots of the data and statistical analyses failed to show evidence of correlation of any practical significance between the data generated by the two methods. A number of unquantifiable variables were enumerated for both types of estimates. It is concluded that within this study (1) only minimal correlation was demonstrable between lung doses based on air monitoring and doses based on urinalysis data because of the number of such variables affecting the measurements; and (2) general air data would not be the most useful measure of exposure upon which to base lung dose estimates.

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Twenty-six total knee arthroplasties were performed on 20 patients who were 85 years or older (mean, 87 years). Only those patients with a minimum of 3 years' followup are reported here. One patient died approximately 1 year after surgery, and 4 patients (5 knees) were lost to followup, leaving 20 total knee arthroplasties in 15 patients to be reported. Postoperative results were based on a 100-point scoring system that is a modification of the Knee Society scoring system. Eleven knees received an excellent rating, 4 good, 2 fair, and 3 poor. The primary indication for surgery in this patient population was pain control. Most patients required the continued use of ambulatory assistive devices such as a cane after surgery, but pain relief was good or excellent in 19 of 20 knees and quality of life improved. All patients tolerated the procedure well, with few postoperative complications noted. There was no perioperative mortality, and all wounds healed normally. Total knee arthroplasty is a safe and reliable procedure in the very aged patient for management of pain and deformity secondary to arthritis of the knee.

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We examined the relation between uranium dust exposure and lung cancer mortality among workers employed in four uranium processing or fabrication operations located in Missouri, Ohio, and Tennessee. Among workers who had at least 30 years of potential follow-up, we identified 787 lung cancer cases from death certificates and matched one control to each case. Health physicists estimated individual annual lung doses from occupational exposure primarily to insoluble uranium compounds, using contemporary monitoring data. With a 10-year lag, cumulative lung doses ranged from 0 to 137 centigrays (cGy) for cases and from 0 to 80 cGy for controls. Health physicists assigned annual external radiation doses to workers having personal monitoring records. Archivists collected smoking information from occupational medical records. Odds ratios for lung cancer mortality for seven cumulative internal dose groups did not demonstrate increasing risk with increasing dose. We found an odds ratio of 2.0 for those exposed to 25 cGy and higher, but the 95% confidence interval of 0.20 to 20 showed great uncertainty in this estimate. There was a suggestion of an exposure effect for workers hired at age 45 years or older. Further analyses for cumulative external doses and exposures to thorium, radium, and radon did not reveal any clear association between exposure and increased risk, nor did dichotomizing workers by facility.

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Dosimetry data are required for many epidemiologic studies of radiation workers. For several reasons, these data may not be available for some workers for some periods of time. An estimate of a worker's dose for such a time period can be made using data from nearby time periods for the worker or using data obtained for other workers during the same time period. This paper reports the results of an evaluation of a procedure for estimating external doses for workers included in retrospective epidemiologic studies. This evaluation was conducted using data for workers who had recorded doses for each year in a 5-y period. The dose for the middle year of the 5-y period was treated as unavailable and the dose was estimated several ways. These estimates were compared with the recorded dose. It was observed that averaging a worker's dose data for the years preceding and following a year for which data hypothetically were not available most often yielded the best estimate of the dose. At one facility studied, the use of nearby data for the same worker was a more reliable estimate for a dose than was the department or facility median or mean dose. However, at another facility, use of the department median or mean dose produced a more accurate estimate than did nearby data for the worker. These results indicate that a single procedure for estimating doses is not best for all facilities, and it is recommended that a test of the type reported in this paper be performed before a decision is made on how to estimate doses. The use of department medians or means to estimate doses consistently produced better estimates than were obtained using facility medians or means.

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Accurate measurements of radiation exposure for individuals are critical to assessing radiation-mortality associations. This paper is based on a study of changes in recorded doses and in radiation monitoring programs at Oak Ridge National Laboratory, a U.S. Department of Energy facility where whole body external penetrating radiation exposures have been of primary epidemiological interest. External radiation monitoring data from 1943-1984 are analyzed for a group of white males (N = 8,318). The proportion of workers monitored for external radiation increased from about 50% in 1943 to over 80% in 1944 to above 98% after 1948. Mean radiation doses showed maxima in 1944 and 1957, followed by steady and long-term declines. Numerous changes in monitoring programs occurred during the study period, including changes in the types of dosimeters used, the frequency of reading dosimeters, methods of calculating doses, and practices of recording doses. Temporal patterns of doses in the lower range of the distribution showed some changes suggestive of changes in policies and practices for recording doses, which would influence dose values used in epidemiological studies. Reliable and accurate exposure measurements are especially important in studies of low level exposures due to small differences in outcomes between exposure groups. Evidence of changes in recorded doses due to monitoring and recording practices, rather than to actual changes in exposures in this well-monitored population, suggests the importance of comparable studies of other populations used for epidemiological studies of radiation-mortality associations.

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A previous study of mortality among white men hired at Oak Ridge National Laboratory between 1943 and 1972 (n = 8,318) revealed an association between low-dose external penetrating ionizing radiation and cancer mortality in follow-up through 1984. The association was not observed in follow-up through 1977. This report considers the role of possible selection and confounding factors not previously studied. Control for hire during the World War II era and employment duration of less than 1 year had little effect on the radiation risk estimates. Risks associated with length of time spent in 15 job categories were considered as proxies for the effects of other occupational carcinogens. Adjustment for employment duration in each job category one at a time produced only small changes in the radiation risk estimate. Adjustment for potential exposures to beryllium, lead, and mercury also had little effect on the radiation risk estimates. These analyses suggest that selection factors and potential for chemical exposure do not account for the previously noted association of external radiation dose with cancer mortality. However, power to detect effects of chemical exposures is limited by a lack of individual exposure measures.

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A retrospective cohort mortality study was conducted in a population of workers employed at a facility with the primary task of production of nuclear fuels and other materials. Data for hourly and salaried employees were analyzed separately by time period of first employment and length of employment. The hourly (N = 6,687 with 728 deaths) and salaried (N = 2,745 with 294 deaths) employees had a mortality experience comparable to that of the United States and, in fact, exhibited significant fewer deaths in many categories of diseases that are traditionally associated with the healthy worker effect. Specifically, fewer deaths were noted in the categories of all causes, all cancers, cancer of the digestive organs, lung cancer, brain cancer (hourly workers only), diabetes, all diseases of the circulatory system, all respiratory diseases, all digestive system diseases, all diseases of the genitourinary system (hourly only), and all external causes of death. A statistically significant, and as yet unexplained increase in leukemia mortality (6 observed vs. 2.18 expected) appeared among a subset of the hourly employees, first hired before 1955, and employed between 5-15 years.

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In a nested case-control study of workers employed between 1943 and 1977 at two nuclear facilities, we evaluated the possible association of primary CNS cancers with occupational exposure to chemicals. Seventy-two white male and 17 white female workers who, according to the information on death certificates, died of primary CNS cancers were identified as cases. For each case, four controls were matched on race, sex, facility at which initially employed (cohort), year of birth, and year of hire. Each job title/department combination was subjectively evaluated for potential exposure to each of 26 chemicals or chemical groups. Statistically significant associations were not found between CNS cancer deaths and any of the 26 chemicals. An increased risk of CNS cancer occurrence was observed among subjects employed for more than 20 yr (OR = 7.0, 95% CI = 1.2,41.1, cases = 9).

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A retrospective cohort mortality study was conducted among 8375 white male employees who had worked at the Oak Ridge National Laboratory for at least one month between 1943 and 1972. This plant has been the site of energy related research, including uranium and plutonium reactor technology and radioisotope production. Radiation doses, primarily from gamma rays, were generally low; the median cumulative exposure for workers was 0.16 rems. Historical follow up was conducted for the years 1943-77 and ascertainment of vital status was achieved for 92.3% of the cohort. Standardised mortality ratios (SMRs) were computed to contrast the subjects' cause specific mortality experience with that of the United States white male population. The observed number of 966 deaths from all causes was 73% of the number expected. Mortality deficits were also seen for arteriosclerotic heart disease (SMR = 0.75; 344 observed) and all cancers (SMR = 0.78; 194 observed). These results are indicative of the healthy worker effect and the favourable influence on health of the cohort's relatively high socioeconomic status. Non-statistically significant raised SMRs were seen for all leukaemias (SMR = 1.49, 16 observed), cancer of the prostate (SMR = 1.16, 14 observed), and Hodgkin's disease (SMR = 1.10, 5 observed). Internal comparisons of mortality (standardised rate ratios, SRRs) were made between subgroups of the cohort according to radiation dose level and duration of employment in various job categories. No consistent gradients of cause specific mortality were detected for radiation exposure. Leukaemia mortality was highest among workers with greater than or equal to 10 years employment in engineering (SRR = 2.40) and maintenance (SRR = 3.12) jobs. The association of leukaemia with employment in engineering was unexpected; maintenance jobs entail potential exposures to radiation and to a wide range of organic chemicals; metals, and other substances.

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A cohort of 2,133 white males who were exposed to elemental mercury vapors between 1953 and 1963 was followed up through the end of 1978. Death certificates were obtained for 371 of the 378 workers who were reported by the Social Security Administration to be deceased. The mortality experience of this group was compared with the age-adjusted mortality experience of the U.S. white male population. Mortality has not been studied previously in assessing the long-term health effects of mercury exposure. Standardized mortality ratios (SMRs) were calculated for a comparable unexposed worker population to determine the mortality patterns among workers at the same plant who were not involved in the mercury process. Statistically significant excesses of deaths from cancer of the lung (SMR = 1.34; 71 observed, 52.9 expected) and cancer of the brain and other CNS tissues (SMR = 2.30; 13 observed, 5.65 expected) were observed among the plant workers who were not involved in the mercury process. An excess of deaths from cancer of the lung was also observed among the mercury workers (SMR = 1.34; 42 observed, 31.36 expected), although the elevation of this SMR was not statistically significant. Since excesses of lung cancer were evident in both groups of workers, it is unlikely that they are related to the mercury exposure and more probable that they are due to some other factor present in the plant or to some life-style factor prevalent among the plant workers.(ABSTRACT TRUNCATED AT 250 WORDS)

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A regimen of thiacetarsamide sodium (0.22 ml/kg twice daily for 2 days) plus levamisole phosphate (11 mg/kg/day for 10 days) was effective in eliminating unidentified microfilariae from the blood in seven of eight tamarins. No serious side effects resulted from the treatment. All of the animals were initially freed of circulating microfilariae after treatment, and five have remained microfilaria-negative for 1 year. Two of the tamarins died of causes unrelated to filariasis and were microfilaria-negative before death. One tamarin remained microfilaria-positive after two courses of this treatment.

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