Biomedical subjects

J C Reading

Publications and source records attributed to J C Reading.

At least 37 records · Page 2Linked to original sources

PubMed1986

Longitudinal evaluation of pulmonary function in copper smelter workers exposed to sulfur dioxide.

From 1973 to 1974, a longitudinal study of pulmonary function in 113 Utah copper smelter workers reported significant declines in FVC and FEV1 related to sulfur dioxide exposure. In 1980, we performed a 7-yr follow-up study, finding significant increases in FVC and FEV1. The 66 follow-up participants were similar to those 47 lost to follow-up with regard to age and initial pulmonary function. Subgroups of smelter workers with initial higher exposures to sulfur dioxide and FEV1 less than 90% predicted did not show an accelerated rate of decline. To reconcile these differences between the 2 studies, we reevaluated the spirometry curves from 1973 and 1974. All had short expiratory times, with none 6 s or longer, whereas all of the curves from the spirograms obtained in 1980 exceeded 6 s. In addition, from 1980 to 1983, we performed a longitudinal study of 48 of the original workers, finding small annual mean declines for FVC of 6 ml and FEV1 of 5 ml. Personal exposures to sulfur dioxide were not significantly different in 1982 than in 1976; thus, we were unable to corroborate the findings of the initial longitudinal study.

Copper↗

PubMed1986

Respiratory effects of mesquite broiling.

Mesquite wood charcoal has been widely promoted for the unique taste it imparts to broiled food. We recently examined a 21-year-old mesquite broiler cook with evidence suggestive of respiratory allergy or irritation following exposure to mesquite broiler smoke in a Salt Lake City restaurant. We subsequently surveyed 13 mesquite and 17 gas-flame ("charcoal") broiler cooks to determine the prevalence of respiratory symptoms among workers exposed to broiler smoke. The survey demonstrated statistically significant (P less than or equal to .05) respiratory irritation in the mesquite broiler group compared with the gas-flame broiler group in one of four symptom categories. Two other symptom categories strongly suggested the presence of (P less than .10) respiratory irritation in the mesquite broiler group. Personal air sampling was conducted or two mesquite broiler cooks and two gas-flame broiler cooks and compared. Unidentified saturated and unsaturated aliphatic hydrocarbons (C8 through C12) with high molecular weights from 108 to 182 were present in air samples from the mesquite broiler cooks and not in the air samples from the gas-flame broiler cooks.

Adult↗

PubMed1985

Reduced joint count indices in the evaluation of rheumatoid arthritis.

Two types of summary measures of joint disease were evaluated in 2 controlled clinical trials in rheumatoid arthritis patients. One measure was based solely on the clinical/biologic judgment approach; the other combined this methodology with statistical approaches using reliability and factor analyses. "Signal joint" indices, summarizing disease activity in 2-5 key joints, were found to be insensitive to deterioriation of nonsignal joints. Therefore, they are not recommended as replacements for the complete articular survey in rheumatoid arthritis. A reduced version of the complete articular survey was found to be desirable based on its validity, reliability, accuracy, precision, and sensitivity to active drugs. Its sensitivity can be slightly higher or lower than that of the full joint survey.

Arthritis, Rheumatoid↗

PubMed1985

Uses and abuses of analysis of covariance in clinical trials.

Measurement of improvement in clinical trials in chronic diseases commonly compares baseline data to endpoint values by performing t-tests or analysis of variance (ANOVA) on raw gains or percentage changes. This procedure can be misleading and the use of an analysis of covariance (ANCOVA) should be considered. Properly used, ANCOVA increases statistical power in a clinical trial. However, its advantage over t-tests can be nullified by small numbers of patients, violations of assumptions, and incorrect application of the techniques. An evaluation of ANCOVA in chronic disease studies is given, with examples of its strengths and weaknesses as seen in several drug trials in the rheumatic diseases. Recommendations on its use and a decision tree for the nonstatistician are provided.

Analysis of Variance↗

PubMed1984

Randomized, double-blind, placebo controlled trial of low-dose pulse methotrexate in psoriatic arthritis.

Thirty-seven patients with psoriatic arthritis were entered into a 12-week prospective, controlled, double-blind multicenter trial comparing placebo and oral pulse methotrexate therapy. Methotrexate was given in a dose of 2.5-5.0 mg every 12 hours in 3 consecutive doses per week. A stable background medication program with nonsteroidal antiinflammatory drugs was allowed. Methotrexate was superior to placebo only in physician assessment of arthritis activity and in improvement of the amount of skin surface area with psoriasis. A small but statistically significant rise of serum total bilirubin occurred in the methotrexate-treated patients. No patients were withdrawn from the study for adverse drug effects.

Adult↗

PubMed1984

Azathioprine versus D-penicillamine in rheumatoid arthritis patients who have been treated unsuccessfully with gold.

Two hundred six patients were entered into a prospective controlled, double-blind, multicenter trial comparing azathioprine (AZA) 1.25-1.5 mg/kg/day with D-penicillamine (DP) 10-12 mg/kg/day. One hundred thirty-four patients completed 24 weeks of therapy. Improvement in nearly all efficacy variables was seen in both groups. Patients taking DP demonstrated a greater rise in hemoglobin concentration and greater fall in erythrocyte sedimentation rate than patients receiving AZA; these were the only efficacy variables with a significant difference between the treatment groups. Fewer withdrawals for adverse reactions occurred among the patients receiving AZA, but the difference was not significant. Patients receiving AZA were withdrawn from the drug mainly for abnormal liver function test results, nausea and gastrointestinal upset, and leukopenia. The main reasons for withdrawal of patients receiving DP were nausea, rash and pruritus, thrombocytopenia, dysgeusia, and proteinuria.

Arthritis, Rheumatoid↗

PubMed1984

Auranofin, gold sodium thiomalate, and placebo in the treatment of rheumatoid arthritis. Cooperative systematic studies of rheumatic diseases.

Two hundred eight patients were studied in a prospective, controlled, double-blind multicenter trial comparing auranofin (AUR), gold sodium thiomalate (GST), and placebo. One hundred sixty-one patients completed at least 20 weeks of therapy. Response to a variety of measures of efficacy was generally modest for both gold treatment groups although improvement was continuing in both groups at the end of the study. There was statistically significant improvement with both gold preparations compared to placebo for the number of tender joints, the joint tenderness score, and physician assessment of disease severity. GST was also significantly better than placebo for the joint swelling score. GST demonstrated more improvement in patients with anemia and thrombocytosis compared to the other treatment groups and both gold preparations were superior to placebo in improvement of an elevated erythrocyte sedimentation rate. Twenty-seven percent of patients on GST were withdrawn from the study for adverse drug reaction with rash and stomatitis being the predominant cause. Only 6% of patients on AUR were withdrawn for untoward drug effect. The time of onset of the adverse reactions is discussed. The two gold preparations were similar in efficacy although AUR was better tolerated.

Anti-Inflammatory Agents↗

PubMed1983

Comparison of auranofin, gold sodium thiomalate, and placebo in the treatment of rheumatoid arthritis. Subsets of responses.

A comparison of placebo, auranofin, and parenteral gold sodium thiomalate therapy in 209 patients with active rheumatoid arthritis was performed in a 21-week prospective, controlled, double-blind multicenter trial. When the 161 patients who completed at least 20 weeks of treatment were analyzed for different degrees of response, no remissions were identified. When 50 percent or greater improvement of pain/tenderness scores were compared for end of trial versus entry values, 9 percent of placebo-treated patients, 34 percent of auranofin-treated patients, and 48 percent of gold sodium thiomalate-treated patients showed important improvement that was statistically significant for both gold treatments. When 50 percent improvement for joint swelling was analyzed, 12 percent of the placebo-treated group, 28 percent in the auranofin-treated group, and 37 percent in the gold sodium thiomalate-treated group showed this degree of improvement. Auranofin almost achieved statistical significance for improvement in joint swelling when compared with placebo (p = 0.07), but gold sodium thiomalate was much better than placebo (p = 0.009). There was no statistically significant difference between the two gold treatments. Thus it appears that a subset of patients had an important response to gold therapy that would not be evident by the usual analyses of mean or median changes. Analysis for predictors of response did not discriminate between responders and nonresponders. Because the trial was limited to 21 weeks of therapy, no prediction of the longer-term-effects, especially for auranofin, should be inferred.

Adolescent↗

PubMed1983

Low-dose D-penicillamine therapy in rheumatoid arthritis. A controlled, double-blind clinical trial.

Two hundred twenty-five patients with active severe rheumatoid arthritis were admitted to a multiclinic, controlled, double-blind trial comparing the use of 500 mg D-penicillamine per day, 125 mg D-penicillamine per day, and placebo. One hundred seventy-one patients completed at least 30 weeks of therapy. The 500 mg D-penicillamine group demonstrated statistically significant improvement over the placebo group in grip strength, average circumference of swollen proximal interphalangeal joints, and patient assessment. While the trend was for greater improvement with the larger dose of D-penicillamine, there was no statistically significant difference among the 3 groups in duration of morning stiffness, walking time, physician's assessment, number of swollen joints, or scores for tender and swollen joints. The slight increase in efficacy of higher dose D-penicillamine was associated with increased toxicity.

Adolescent↗

PubMed1983

Comparison of auranofin, gold sodium thiomalate, and placebo in the treatment of rheumatoid arthritis. A controlled clinical trial.

A prospective controlled, double-blind multicenter trial compared placebo, auranofin (an orally administered gold complex), and parenteral gold sodium thiomalate (GST) in patients with active rheumatoid arthritis (RA). Of 193 patients who received any treatment, the only important improvement identified for either auranofin or GST was for pain/tenderness scores. When 161 patients who completed 20 weeks of treatment were examined, both auranofin and GST treatments were superior to placebo as measured by improvement in number of painful and/or tender joints, joint pain/tenderness scores, physician's assessment of disease activity, and decrease in erythrocyte sedimentation rate when elevated at entry. GST was superior to placebo in improvement of joint swelling scores, anemia, thrombocytosis, and rheumatoid factor. No drug-related remissions were observed. The only statistically significant advantages of GST over auranofin for efficacy were an increase in hemoglobin concentration and decrease of thrombocytosis with GST. Withdrawals for adverse effects were 5 times more frequent with GST treatment. Thrombocytopenia, proteinuria, elevated liver enzymes, "nitritoid" reactions, and "gold pneumonitis" were observed only in the GST treatment group. These results confirm that both parenteral and oral gold may be effective for the treatment of RA, that GST tends to show greater efficacy than auranofin, and that auranofin has fewer significant adverse effects than GST. However, long-term benefits, tolerability, and safety cannot be inferred from this study.

Adolescent↗

PubMed1983

Evaluating slow-acting antirheumatic drug therapies for rheumatoid arthritis.

Clinical trials with slow-acting or disease-modifying drugs in rheumatoid arthritis are difficult to design and execute. Such trials are expensive and require long periods of observation. However, there is no acceptable alternative to the properly designed and completed controlled clinical trial. Broad principles for the design of such trials and the basic elements of the study design are outlined and discussed.

Anti-Inflammatory Agents↗

PubMed1983

Design and analysis of controlled clinical trials in rheumatic diseases.

Controlled clinical trials can be difficult, expensive, and time-consuming, but are necessary to advance the knowledge concerning rheumatic disease. Proper care in the design of the study and appropriate statistical analysis of the data can result in studies that answer specific questions and are well worth the effort and expense. If the design is well planned before the entry of the first patient, many problems will be avoided and the results will be credible.

Clinical Trials as Topic↗

PubMed1981

Risk factors for postoperative pneumonia.

Prospectively studied were 520 patients undergoing elective thoracic, upper abdominal and lower abdominal surgeries to analyze risk factors for postoperative pneumonias. Over-all, pneumonias developed in 91 of the 520 patients studied (17.5 percent). The acquisition of pneumonia was highly associated with preoperative markers of the severity of underlying diseases such as low serum albumin concentrations on admission (P less than 0.005) and high American Society of Anesthesiologists pre-anesthesia physical status classification (P less than 0.0001). History of smoking (P less than 0.001), longer preoperative stays (P less than 0.0001), longer operative procedures (P less than 0.0001) and thoracic or upper abdominal sites of surgery (P less than 0.0001) were also significant risk factors for postoperative pneumonias. Although massive obesity, old age and male sex were also associated with increased incidences of pneumonia, statistical significance was lost when these variables were controlled for site or duration of surgery. We were able to identify risk factors for pneumonia and to define a subpopulation of patients in which the risk of pneumonia was negligible. The acquisition of pneumonia by a low-risk patient should alert the physician to the possibility of a potentially preventable nosocomial infection.

Adult↗

PubMed1981

Myocardial infarction: a five-year follow-up of patients.

Patients with acute myocardial infarction (2,020) admitted to coronary care units (CCU) in Utah were studied for five years. Of these, 1,641 (81.4 percent) survived to leave the hospital. The male to female ratio was 3.5:1. At four months, one year and yearly thereafter from the date of admission to CCU, patients were mailed follow-up questionnaires. Cause of death was obtained from autopsy reports and death certificates. Patients were grouped yearly by the number of cardiac symptoms reported. Of patients discharged whose cases were followed, 925 (61.9 percent) were alive after five years. Reinfarction was the major cause of death in the hospital; however, during follow-up only 36.8 percent of deaths were attributable to myocardial infarction. At follow-up after a year, fewer cardiac symptoms were reported by patients who survived to the fifth year of follow-up than by patients who did not. Women were older and showed a higher death rate during follow-up. Increasing age was found to be a determining factor in long-term mortality after acute myocardial infarction.

Adult↗

PubMed1980

Chronic cadmium exposures associated with kidney function effects.

A follow-up study was conducted on 27 workers with a median of 25 years exposure to airborne cadmium. Two exposure groups had been selected a low exposure group of office, laboratory and supervisory personnel (n = 11, average urinary cadmium 13.1 micrograms/l); and a high exposure group of production workers with long histories of work in areas with substantial airborne cadmium (n = 16, average urinary cadmium 45.7 micrograms/l). An estimate of each subject's time-weighted-average inhalation exposure to cadmium was calculated from personal sampling data (1973-1976) and area sampling data (1943-1976). Based on the findings of another study, the average inhalation exposures in each of the work areas were adjusted for use of personal protective masks (respirators). Comparison of kidney function status between the high and low exposure groups showed a significant reduction in creatinine clearance, and increased uric acid and beta microglobulin excretion by the high group. Significant renal effects were associated with estimated average inhalation exposures of 63 micrograms/m3 over a 25 year period. The relationship between urinary cadmium excretion and cumulative exposure changed for higher exposures; this was consistent with the "critical concentration" model of cadmium's effects on the kidney.

Air Pollutants, Occupational↗

PubMed1980

Comparison of high and low dose cyclophosphamide therapy in rheumatoid arthritis.

Eighty-eight patients with active rheumatoid arthritis from 8 Cooperating Clinics were evaluated in a 32-week controlled, double-blind trial comparing 150 mg daily to 75 mg cyclophosphamide daily. Improvement in the arthritis was seen in both groups, and there were no important differences between the two treatment groups in any of the 8 variables used to measure disease activity. Untoward effects were also similar for the two groups. These results differ from preliminary results reported earlier.

Adult↗

PubMed1979

Attitudes of women toward the gynecologic examination.

This study was undertaken to determine why patients feel uncomfortable during the gynecologic examination, to assess general knowledge about the procedures, and to find out what would make the patient feel better about the examination. Nine hundred seventy-seven women sampled in 14 different health care facilities in the Salt Lake area in Utah filled out a two-page, self-administered questionnaire while waiting for a medical appointment. Results show that women feel less comfortable during the pelvic examination than they do during the breast examination; physical discomfort of the pelvic examination is the reason most frequently cited. There were 77.1 percent who stated they would feel better about the examination if the physician told them what was going to happen. Over 70 percent wanted to know more about their female organs, normal sexual functions and emotions, and reasons and procedures for the pelvic examination; 68.3 percent felt that knowing more would make them more comfortable. There were 46.5 percent who thought the use of a mirror for the woman to observe the examination was a good idea. Only 28.9 percent knew the rectum was examined. This study shows that women need and want to be educated about the gynecologic examination.

Attitude to Health↗

PubMed1977

Pulmonary impairment from chronic exposure to sulfur dioxide in a smelter.

The pulmonary function of 113 copper smelter workers was measured in 1973 and again in 1974 to asses the effects of chronic exposure to sulfur dioxide. Respiratory symptoms, smoking history, occupational history, and pulmonary function as measured by forced vital capacity and 1-sec forced expiratory volume were recorded. Exposures to sulfur dioxide, respirable particulates, sulfates, and copper were sampled at intervals throughout the year by personal monitoring. Exposure to 1.0 to 2.5 ppm of sulfur dioxide was associated with excessive loss of 1-sec forced expiratory volume during the year and an increase in respiratory symptoms, after controlling for smoking. No significant interaction between sulfur dioxide and concurrent exposure to respirable particulates on pulmonary function was found. Workers with 1-sec forced expiratory volume below normal on initial measurements (based on their age and height) showed evidence of even greater losses of pulmonary function related to sulfur dioxide exposure.

Adult↗