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Biomedical subjects

H E Rockette

Publications and source records attributed to H E Rockette.

At least 73 records · Page 4Linked to original sources
PubMed1985

Equivalency of alternative cotton dust samplers to the vertical elutriator.

The OSHA standard for measuring cotton dust permits the use of samplers which have been demonstrated to be equivalent to the vertical elutriator (VE). The standard does not include enough criteria for the equivalency of an alternative device to be determined. Furthermore, the impact of the inherent variability of the VE on the ability to establish equivalency is not addressed in the standard. We propose a protocol which will be statistically sound and, by means of which, the equivalency of any other device to the VE may be determined. We also assess the impact of the variability of the VE on the probability of demonstrating the equivalence of another VE.

Air Pollutants, Occupational↗
PubMed1985

Selection, follow-up, and analysis in the Coke Oven Study.

The current standard for exposure to coke oven emissions sets a permissible exposure of 150 micrograms benzene-soluble fraction of total particulate matter/m3. The major epidemiologic study that formed the basis for this standard including a review of the evidence of a dose-response relationship between exposure to coal tar pitch volatiles and lung cancer is reviewed. Particular attention was given to the selection of the cohort, follow-up procedures, and the evolution of the analysis.

Coal↗
PubMed1984

Evaluation of habitual excessive alcohol consumption on myocardial infarction risk in coronary disease patients.

Overt coronary heart disease does occur at times in a setting of alcoholism. In an attempt to test the hypothesis that habitual excessive drinking may have an aggravating effect upon coexisting ischemic heart disease and may help precipitate new coronary events, we compared myocardial infarct prevalence among heavy drinkers and non-heavy drinkers with angiographically documented coronary artery disease. Infarct prevalence was found to be higher for heavy drinkers than for non-heavy drinkers under age 60 years, after controlling for differences in smoking habits and underlying atherosclerosis severity. A reversal in trend which may be due to the operation of selective factors causing premature coronary death among alcoholics was observed for individuals above age 60 years. These results, although open to differing interpretations, are consistent with the notion that heavy drinking has a destabilizing effect upon preexisting ischemic heart disease and may increase acute coronary event risk.

Adult↗
PubMed1984

Diabetes and hypercholesterolemia among patients with calcific aortic stenosis.

To help clarify the etiology and pathogenesis of calcific aortic stenosis, we studied retrospectively the relationship existing between that condition and two presumptive risk factors: diabetes and hypercholesterolemia. Fifty-four patients with isolated aortic stenosis, undergoing cardiac catheterization, were compared to patients without aortic stenosis who underwent angiography for unrelated reasons. The effect of diabetes and hypercholesterolemia, singly and in combination, upon the prevalence of aortic stenosis, was tested by various methods, including mathematical model fitting: Both study factors were found to be associated with aortic stenosis; their combined effect upon the prevalence of that disease appeared to be multiplicative. These findings suggest that diabetes and hypercholesterolemia may play a role in the causation of aortic stenosis. Further studies among unselected populations are needed to confirm the existence of the associations uncovered.

Age Factors↗
PubMed1983

Lack of efficacy of a decongestant-antihistamine combination for otitis media with effusion ("secretory" otitis media) in children. Results of a double-blind, randomized trial.

In a double-blind, randomized trial of 553 infants and children who had otitis media with effusion ("secretory" otitis media), we compared the efficacy of a four-week course of an oral decongestant-antihistamine combination (pseudoephedrine hydrochloride, 4 mg per kilogram of body weight per day, and chlorpheniramine maleate, 0.35 mg per kilogram per day) with that of placebo. Among patients with initially unilateral disease, resolution of middle-ear effusion occurred at four weeks in 38 per cent of those treated with placebo and 34 per cent of those treated with drug (P = 0.74). Among patients with initially bilateral disease the corresponding proportions were 19 and 21 per cent, respectively (P = 0.67). Side effects were reported more often among drug-treated than placebo-treated patients. Decongestant-antihistamine combinations do not appear to be indicated for the treatment of otitis media with effusion in infants and children.

Child↗
PubMed1983

Relation of estrogen and/or progesterone receptor content of breast cancer to patient outcome following adjuvant chemotherapy.

In 1977 the National Surgical Adjuvant Breast and Bowel Project (NSABP) initiated a prospectively randomized clinical trial to evaluate the relative merits of 1-phenylalanine mustard and 5-fluorouracil (PF) with and without tamoxifen (T) as adjuvant therapy for patients with primary breast cancer and positive axillary nodes. A previous presentation of findings noted that there was a strong relationship between the outcome of those receiving PFT and the estrogen receptor (ER) and progesterone receptor (PR) content of their tumors. This report relates the outcome of the PF-treated patients in that trial with these tumor receptors. It indicates that the results observed following nonhormonal therapy (PF) are also related to tumor receptors. Both the disease-free survival (DFS) and survival (S) of women following PF therapy were influenced by the ER and PR content of their tumors. Subsequent to adjustment for other prognostic variables, the predictive influence of tumor ER persisted. Both the DFS (p = 0.0003) and the S (p = 0.00003) were significantly higher in those with greater than or equal to 10 fmol tumor ER than in those with less than 10 fmol ER. The PR significantly added to the predictive value of ER. Thus, this analysis is the first to demonstrate that having information on both ER and PR is important for predicting outcome of patients receiving adjuvant chemotherapy. The study does not provide information which correlates receptor status with the response of patients to adjuvant chemotherapy since there is no similar nonchemotherapy-treated group of patients in the trial. The findings continue to emphasize that there is a heterogeneity in outcome of breast cancer patients to adjuvant chemotherapy which is related to an increasing number of host and tumor variables. For proper assessment of overall results, it is essential that analyses employ tests for interaction to indicate homogeneity or heterogeneity of patient subsets and that adjustments be made for imbalances in tumor ER and PR as well as in other prognostic factors.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed1983

The prognostic significance of tumor location and bowel obstruction in Dukes B and C colorectal cancer. Findings from the NSABP clinical trials.

The present study examines the prognostic significance of tumor location and bowel obstruction in Dukes B and C colorectal cancer. Data were obtained from 1021 patients entered into two randomized prospective clinical trials of the NSABP. Tumor location proved to be a strong prognostic discriminant. Lesions located in the left colon demonstrated the most favorable prognosis. Tumors of the rectosigmoid and rectum had the worst prognosis with the relative risk of treatment failure for the latter being over three fold that of the left colon. When the relative risks associated with tumor location were adjusted for nodal imbalances, the left colon continued to demonstrate the most favorable prognosis. The presence of bowel obstruction also strongly influenced the prognostic outcome. Examination of the data without considering tumor location disclosed that patients with bowel obstruction were at greater risk for treatment failure than those without obstruction. The effect of bowel obstruction was influenced by the location of the tumor. The occurrence of bowel obstruction in the right colon was associated with a significantly diminished disease-free survival, whereas obstruction in the left colon demonstrated no such effect. This phenomenon was independent of nodal status and tumor encirclement, the latter two factors proving to be of prognostic significance independent of tumor obstruction. A multivariate analysis in which the covariate effects of sex, age, nodal status, tumor obstruction, encirclement, and tumor location were adjusted underscored the role of tumor location and obstruction as prognostic discriminants. The results indicate that the definition of prognostic factors can identify patient subsets with unique characteristics.

Carcinoma↗
PubMed1983

A comparison of methods to interpret the basal body temperature graph.

Specific criteria are given for several methods of determining the basal body temperature shift. The specific criteria selected have been coded for a uniform interpretation by computer, and interpretations have been compared for 8496 charts. Our results indicate that the method that defines the temperature shift as 0.3 degrees F or more above the running low average for at least 3 consecutive days provides the best concurrent chart interpretation method. A method that creates a smoothed curve that transects the average of all temperatures on a completed graph provides a good retrospective method for identifying the temperature shift. Both the temperature averaging technique and curve smoothing technique identified a temperature shift in more than 95% of the charts with complete temperature readings.

Adolescent↗
PubMed1983

Mortality studies of aluminum reduction plant workers: potroom and carbon department.

The purpose of this study was to investigate mortality patterns of aluminum reduction plant workers. A cohort was formed of 21,829 workers with five or more years employment in 14 reduction plants. Progress of the study was reported quarterly to a Tripartite Committee consisting of representatives from labor, management and government. Although the results of other studies relative to an excess of lung cancer in aluminum workers were not confirmed, there were indications of a higher than expected mortality in pancreatic cancer, lymphohematopoietic cancers, genitourinary cancer, nonmalignant respiratory disease and benign and unspecified neoplasms.

Aluminum↗
PubMed1982

Impact of randomized clinical trials on therapy of primary breast cancer: the NSABP overview.

The history of treatment for early breast cancer, particularly as it relates to the most recent calendar decade, exemplifies the contribution that can be made to resolving therapeutic controversies by well-designed prospective randomized clinical trials (RCTs). In this article we provide an overview of the breast cancer clinical trials that have been conducted by the National Surgical Adjuvant Project for Breast and Bowel Cancers (NSABP) since 1971. These trials have had a strong impact in changing the clinical management of breast cancer over the past decade. Emphasis will be given to those aspects of the studies that demonstrate the advantages and/or necessity for RCTs to evaluate alternative therapeutic approaches to the management of breast cancer.

Antineoplastic Agents↗
PubMed1978

Evaluation of multiple causes of death in occupational mortality studies.

An exploratory examination of the possibility of using multiple causes of death information from death certificates in mortality studies has been undertaken. The formation of a matrix of primary by contributory causes has been suggested. The matrix gives an overall picture of mortality patterns, serves as a scheme to identify disease combinations, and can be utilized as a data-editing device. From the matrix, several conventional, as well as several new statistics can be computed. The methodology has been illustrated with data from a cohort of steelworkers. The gain in information as a result of routinely recording multiple causes of death has also been discussed.

Age Factors↗
PubMed1977

Cause specific mortality of coal miners.

The purpose of this study was to compare the cause specific mortality of the U.S. coal miner to the mortality of the total U.S. male population. A 10% sample was taken of those men covered by the United Mine Workers Health and Retirement Funds on January 1, 1959, and the resultant 23,232 miners were followed through December 31, 1971. The overall SMR was 102.1, and there was higher than expected mortality in several categories of nonmalignant respiratory disease, accidents and stomach cancer. The excess in stomach cancer occurred only for those men 70 years of age or older.

Accidents↗
PubMed1976

Long-term mortality study of steelworkers.

This study examines the cause-specific mortality of men employed as masons in the steel industry. Their mortality experience is compared with the mortality predicted by the age--and race--specific death rates for a control group consisting of those steelworkers whose first job in 1953 was not in the mason department. The relative risks of dying from selected causes were highly dependent on race. The most important observations are: (1) The nonwhites have an overall excess risk when compared to the nonmason group. This excess is not confined to any particular category and appears to be due to the cumulative effect of an excess in many different categories. (2) The white masons have an excess risk for nonmalignant respiratory disease. Furthermore, this risk increases with length of exposure. (3) The whites have an excess risk for respiratory cancer when compared to the nonmason group. This excess is not present in the later years of the follow-up period. (4) The interpretation of the findings for cardiovascular disease remain unclear. Results for cerebral vascular disease and hypertensive disease in nonwhites are suggestive, but need further investigation before any strong statements can be made.

Adult↗
PubMedDate not supplied

Evaluation of the proportionate mortality index in the presence of multiple comparisons.

We investigate the frequency in occupational studies of falsely identifying significantly elevated cause-specific mortality in the presence of multiple comparisons. When one investigates a standard battery of causes of death, use of a standardized mortality ratio as a summary index results in an excessive experimental error rate, but one can control the error rate with use of standard procedures that limit the type I error. When a major disease category for an occupational cohort has a lower rate than expected, then with use of a proportionate mortality ratio as a summary index, the standard procedures for control of the type I error are inadequate. In this situation, use of a proportionate mortality ratio as a summary index is likely to result in the false identification of an excess cause-specific mortality more often than previously acknowledged.

Biometry↗
PubMedDate not supplied

Normal subject postural sway during the Romberg test.

Analysis of fixed force platform recordings of Romberg tests performed by 132 normal subjects demonstrated no statistically significant sex or age effect for adults aged 20 through 49 years. There was a strong stabilizing influence of vision upon postural control in most, but not all, normal subjects. Comparison trials showed no statistically significant differences between trials for the standard Romberg eyes-open maneuver. However, a significant improvement was demonstrated for the second trial for all other Romberg maneuvers. Tests repeated over a period of five consecutive days yielded results with large variances within normal limits and no systematic individual or group trends. Normal percentiles and confidence intervals for the 95th percentile were calculated for use as a normal data base. These percentile distributions derived from a relatively large population of normal subjects provide a normal statistical base for comparison with postural sway from abnormal subjects.

Adult↗
PubMedDate not supplied

Duration of effusion after antibiotic treatment for acute otitis media: comparison of cefaclor and amoxicillin.

A double-blind randomized clinical trial was conducted at two sites comparing cefaclor and amoxicillin for the treatment of acute otitis media with effusion in 214 children (293 ears). Each child underwent unilateral or bilateral tympanocentesis and then was randomly assigned to receive a 14-day course of either amoxicillin or cefaclor. The symptomatic clinical response was the same for the two antibiotics, with four children considered "treatment failures" in each antibiotic treatment group. By 14 days after entry into the study 59 of 106 children (55.7%) in the cefaclor group had ears that were effusion-free as compared to 40 of 97 children (41.2%) in the amoxicillin group (P = 0.05). When considering all children with effusion-free ears as well as those "improved" from their original status (those with bilateral middle ear effusions at entry but only unilateral after treatment), 68 of 106 children (64.2%) receiving cefaclor were effusion-free or "improved," compared to 43 of 97 children (44.3%) receiving amoxicillin (P = 0.01). However, by 42 days after entry the percentage of children whose ears were without effusion or "improved" was equal in both treatment groups (68.9% in the cefaclor group and 67.5% in the amoxicillin group). The reasons for the differences observed at 14 days after entry are not readily apparent.

Acoustic Impedance Tests↗