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Biomedical subjects

R H Warshaw

Publications and source records attributed to R H Warshaw.

At least 19 recordsLinked to original sources
PubMed1995

Do radiographic criteria for emphysema predict physiologic impairment?

OBJECTIVE: The functional consequences of pulmonary emphysema have been estimated from autopsy studies. This antemortem study correlates structure as assessed by criteria applied to chest radiographs and function in earlier disease. SUBJECTS AND METHODS: Four thousand one hundred seven male shipyard and construction workers had chest radiographs scored for asbestosis using International Labour Office criteria and for emphysema using five criteria: hyperlucent lung fields, low flat diaphragms on posteroanterior views, low flat diaphragms on lateral radiographs, a wide retrosternal space, and bullae. Total lung capacity (TLC) was measured by planimetry of radiographs and forced vital capacity (FVC) and flows by spirometry: TLC minus FVC equaled residual volume (RV). All were expressed as percentage of predicted (% pred) adjusted for height, age, and duration of cigarette smoking. Linear regression modeling examined the influence of each emphysema criterion on function measurements. RESULTS: Four hundred three (10.1%) of 4,107 men had two or more emphysema criteria and 24.5% had asbestosis. Prevalence of 2 criteria varied by smoking status and was present in 20% of current smokers, 7.5% of ex-smokers, and 2% of never smokers. The TLC % pred and RV/TLC increased and % pred of FEV1/FVC and FEF25-75, FEV1, and FVC decreased with increasing radiographic emphysema criteria. Forty-four (10%) had normal results of spirometry with two or more radiographic emphysema criteria. CONCLUSION: Impairment of airway function worsened with each additional radiographic criteria of emphysema. These criteria were more strongly associated with an increase in RV/TLC than an increase in TLC.

Asbestosis↗
PubMed1994

Balance measured by head (and trunk) tracking and a force platform in chemically (PCB and TCE) exposed and referent subjects.

To determine comparability of methods, postural sway was measured simultaneously with a force platform and a device that registers head (and trunk) movements (head tracking). The effects of age, sex, height, weight, shoe area, and grip strength on both measurements were examined in 162 subjects. To determine whether either method had advantages in detecting abnormal balance 46 reference subjects were compared with 116 people randomly selected from 500 residents whose well water was contaminated with polychlorinated biphenyls (PCBs) and trichloroethylene (TCE) from a metal casting plant. Speed, mean radius, and distance of sway were equally reproducible with both methods. Correlation coefficients were 0.672 with the eyes closed and 0.588 with the eyes open. The balance of those exposed to PCBs and TCE was significantly worse than that of unexposed subjects by both head tracking (1.50 + 71 cm/s v 1.27 + 0.36 cm/s; p < 0.034) and the force platform (4.93 + 1.56 N (kg force) v 4.29 + 1.14 N; p < 0.013) with the eyes closed and differences were also significant with the eyes open. Head tracking and the force platform produced equivalent results. Measurement by head tracking is recommended for field studies because the device is more portable and is less influenced by weight and height. Both methods showed impaired balance associated with years of exposure to PCBs and TCE.

Adult↗
PubMed1994

Airways obstruction from asbestos exposure. Effects of asbestosis and smoking.

OBJECTIVE: To define the apparent steps in developing airways obstruction vs restrictive lung disease in men exposed to asbestos for more than 20 years who had never smoked vs cigarette smokers. DESIGN: Physiologic signs of asbestosis were studied in cross-sectional age-matched groups of never, current, and ex-cigarette smoking workers. SETTING AND PARTICIPANTS: The study included 8,720 asbestos-exposed construction and shipyard workers in the United States. MEASUREMENTS: FVC, FEV1, FEF25-75, and FEF75-85 were measured by spirometry and total lung capacity (TLC) by planimetry of standard chest radiographs and adjusted for height, age, and duration of cigarette smoking and expressed as percentage of predicted. TLC minus FVC yielded RV. We compared means and mean residuals (measurement minus group mean) expiratory flows and lung volumes in 1,146 men with pulmonary asbestosis age matched to 1,146 without asbestosis who had similar durations of asbestos exposure and to 370 men without asbestos exposure. Next, flows and volumes were regressed against the International Labour Office (ILO) profusion scale of irregular opacities on chest radiographs (PIO) and the duration of asbestos exposure for 1,777 never smokers (NS), 4,550 current smokers, and 2,393 ex-smokers. RESULTS: Asbestos exposure in NS men decreased expiratory flows and increased TLCs compared with unexposed NS men. Further reductions in flows and FVC and increases RV/TLC with radiographic asbestosis were not statistically significant. As the PIO increased from 1/1 to 3/3, obstruction and air trapping increased significantly but TLC did not. CONCLUSIONS: Asbestos exposure reduced flows and produced air trapping after 20 years in workers who never smoked. Smoking increased these abnormalities.

Adult↗
PubMed1993

A reproducible trigger for the measurement of trigeminal latencies elicited by a glabellar tap.

In order to develop a screening test of trigeminal latencies which could be used in the field, a stimulator which delivered a "tap" consisting of a focused puff of air to the glabella was compared with a tap delivered by means of a lightweight hammer with a piezoelectric trigger similar to that described by Shahani (Shahani and Young, 1972, Neurology 22, 149-154). Results were similar for both methods although the mechanical tap failed to elicit a response from the left side in one subject. The benefit of the air tap is in the reproducible force of the tap and better aim than is possible with the hammer.

Blinking↗
PubMed1993

Measuring lung volumes in advanced asbestosis: comparability of plethysmographic and radiographic versus helium rebreathing and single breath methods.

Total lung capacity was measured in 16 workers with pulmonary asbestosis using four standard methods: body plethysmography, radiographic lung area, helium dilution by multiple breath and by single breath (alveolar volume). All men had irregular opacities of ILO profusion category 2/1 or greater and four had pleural plaques in addition. The radiographic and plethysmographic methods produced virtually identical mean values for TLC of 7.52 l and 7.64 l and for RV of 4.06 l and 4.32 l and all values were larger than those by helium dilution. The closed circuit helium dilution method systematically underestimated TLC with a mean of 5.89 l as did single breath helium dilution with a mean of 6.39 l. These men had a larger mean RV/TLC, measuring 56.9% by body plethysmography and 54.6% by X-ray area than by the rebreathing dilutional method which was 43.8%. Air trapping within a normal TLC which characterizes asbestosis is revealed by radiographic and plethysmographic methods but concealed by gas dilution methods. Use of the latter is at least partly responsible for the impression that asbestosis is a 'restrictive disease'.

Aged↗
PubMed1993

Neurobehavioral testing of subjects exposed residentially to groundwater contaminated from an aluminum die-casting plant and local referents.

Residents adjoining a die-casting plant had excessive headaches, numbness of hands and feet, dizziness, blurred vision, staggering, sweating, abnormal heart rhythm, and depression, which led to measurements of neurobehavioral performance, affective status, and the frequency of symptoms. They had all been exposed via well water and proximity to the plant to volatile organic chemicals (VOC) and to polychlorinated biphenyls (PCBs). The 117 exposed women and men and 46 unexposed referents were studied together for simple and choice visual reaction time, body sway speed, blink reflex latency, color discrimination, Culture Fair (a nonverbal nonarithmetic intelligence test), recall of stories, figures, and numbers, cognitive and psychomotor control (slotted pegboard and trail making A and B), long-term memory, profile of mood states (POMS), and scores and frequencies of 34 symptoms. Choice reaction time, sway speed, and blink latency were impaired in both sexes of the exposed group and trail making B was impaired in exposed women. The POMS scores and frequencies of 30 of 34 symptoms were elevated in both sexes, compared to referents. Recall, long-term memory, psychomotor speed, and other cognitive function tests were reduced in exposed subjects and in the referents as compared to national referents. Neurophysiological impairment, and cognitive and psychomotor dysfunction and affective disorders, especially depression and excessive frequency of symptoms, were associated with the use of wells contaminated with VOCs, TCE and PCBs.

Adolescent↗
PubMed1993

Total lung capacity in asbestosis: a comparison of radiographic and body plethysmographic methods.

The effect of asbestosis on lung volumes was studied in 46 workers by measuring total lung capacity (TLC), forced vital capacity, vital capacity, and residual volume using two standard methods: body plethysmography and radiographic lung area. Nine men had neither irregular opacities of any International Labour Office profusion category nor pleural abnormalities; 9 had pleural abnormalities only, 19 had irregular opacities only; and 9 had pulmonary asbestosis with pleural plagues. Of the 28 with irregular opacities, 18 had moderate or advanced asbestosis (category 2/1 or greater). The radiographic method gave a mean TLC of 8.11 L and the body plethysmographic mean was 8.09 L. Thus, the radiographic and plethysmographic methods produced virtually identical mean values for TLC and for residual volume 3.84 L and 3.8 L and residual volume/TLC, 47.3 and 47.3, respectively. Lung volumes measured by body plethysmography and by x-ray area were the same in each of the four radiographic categories of asbestosis. The air trapping and normal or slightly elevated TLC, which characterize asbestosis in men who have smoked cigarettes, are revealed by both methods. The radiographic method, when adequate measures are taken to obtain full inspirations, effectively duplicates the body plethysmographic method but is quicker and simpler, particularly for field studies.

Adult↗
PubMed1992

Irregular opacities in the lung, occupational asthma, and airways dysfunction in aluminum workers.

We examined chest X-rays, measured expiratory flows and FVC by spirometry and TLC by projected lung area, ascertained respiratory data by questionnaires, and performed chest examinations in 670 Southeastern aluminum workers and 659 unexposed regional controls. Both groups were asbestos exposed. More aluminum workers had irregular opacities and fewer had pleural abnormalities than did regional pipefitter referents. The pulmonary function tests were expressed as percentage of predicted to adjust for height, age and duration of smoking based on a randomly selected U.S. reference population. Data from aluminum workers were compared to regional controls with students "t" tests run for unequal size groups. Aluminum workers had significant reductions in FEV1 of 3.2% predicted (p less than .003), FEF25-75 of 11.3% predicted (p less than .0001), FEF75-85 of 22.5% predicted (p less than .0001), and an increased TLC of 2.0% predicted (p less than .005). The 145 who had never smoked (NS) were compared with 124 NS controls and showed this same pattern of differences; but in smokers, the differences were significant for mid and terminal flows, but not for FEV1. In aluminum workers who never smoked, asthma prevalence by history was 7.6% vs. 4.0% in controls, and wheezes were heard in 21.4% vs. 2.4% in controls. In aluminum workers who were current smokers, asthma prevalence was 16.4% vs. 9.4% in controls, and wheezes were heard in 43.7% vs. 21.1% in controls. Aluminum workers had significantly more asthma, wheezing, airways obstruction, and pulmonary parenchymal abnormalities similar to asbestosis than did regional blue collar controls not melting and casting aluminum.

Aluminum↗
PubMed1992

Prevalence of symptoms of systemic lupus erythematosus (SLE) and of fluorescent antinuclear antibodies associated with chronic exposure to trichloroethylene and other chemicals in well water.

Criteria for the recognition of systemic lupus erythematosus (SLE) were applied to 362 subjects exposed to trichloroethylene, trichloroethane, inorganic chromium, and other chemicals in water obtained from wells in an industrially contaminated aquifer in Tucson, Arizona. Their antinuclear autoantibodies were measured by fluorescence (FANA) in serum. Ten patients with clinical SLE and/or other collagen-vascular diseases were considered separately. Results were compared to an Arizona control group, to published series, and to laboratory controls. Frequencies of each of 10 ARA symptoms were higher in exposed subjects than in any comparison group except those with clinical SLE. The number of subjects than in any comparison group except those with clinical SLE. The number of subjects with 4 or more symptoms was 2.3 times higher compared to referent women and men. FANA titers greater than 1:80 was approximately 2.3 times higher in women but equally frequent in men as in laboratory controls. ARA score and FANA rank were correlated with a coefficient (cc) of .1251, r2 = .0205 (p less than 0.036) in women and this correlation was almost statistically significant in men cc = .1282, r2 = .0253 (p less than 0.059). In control men and women neither correlation was significant. Long-term low-dose exposure to TCE and other chemicals in contaminated well water significantly increased symptoms of lupus erythematosus as perceived by the ARA score and the increased FANA titers.

Antibodies, Antinuclear↗
PubMed1992

Neurobehavioral effects of formaldehyde and solvents on histology technicians: repeated testing across time.

Neurobehavioral functions were studied by periodic testing of 318 histology technicians and by a single session testing 494 of such technicians from 1982 through 1986. Tests included immediate recall of stories, of drawings, and of number series from the Wechsler Memory Scale, block designs from the Wechsler Adult Intelligence Scale (WAIS), slotted pegboard, trail making A and B, embedded figures, number writing on the fingers, visual simple and two-choice reaction times, balance (speed of body sway), and the profile of mood state (POMS) score. Mean test scores of four initial "first test" groups were not different from 1982 to 1986. Immediate recall of stories and drawings improved on the first retest as did the block design score. Other test scores showed insignificant variation over the 4 years, including memory for numbers forward and backward, trails A and B, number writing on fingers, radius of body sway, and choice reaction time. Only placing of pegs in the pegboard took longer. POMS score was lower in the second year in naive subjects and decreased from 39 to 13 in those retested. Variations in results of neurobehavioral tests given at intervals across 4 years were small. No cumulative effects of occupational exposures or of aging were found. However, small decreases may have been offset by increases due to test familiarity or learning.

Adult↗
PubMed1992

Expiratory flows decreased in Los Angeles children from 1984 to 1987: is this evidence of effects of air pollution?

To estimate the effects of air pollution we measured expiratory flows and vital capacities in 556 Mexican-American Los Angeles children in 1984 and 251 in 1987. They included 106 who were measured in 1984 and 1987 and 145 measured only in 1987. Pulmonary function values were standardized for growth be expressing them as percentages of predicted (% pred) based on sex and height. In 1987 mean values for FEV1 and FEF25-75 were lower by 4.5% pred and 13.6% pred respectively (P < 0.001), while vital capacities were not different in 213 children tested as fifth graders in 1984 and 251 fifth grade children in 1987. For the 106 children tested at both sessions (in second grade in 1984 and in fifth grade in 1987) FVC was also not different but FEV1 was 2.0% pred lower (P < 0.06) and FEF25-75 was 7.0% pred lower (P < 0.001). For the 450 children tested only in 1984 and the 106 retested in 1987 there were no significant differences in mean values for FVC, FEV1, and FEF 25-75. Similarly there were no significant differences between the 1987 mean values for 145 children who were studied longitudinally were not different from the 1984 and 1987 cross-sectional cohorts. Across this interval FEV1 and midflows diminished but vital capacities did not. Airways obstruction worsened during children's residence in Los Angeles from 1984 to 1987 and this is probably due to air pollution.

Air Pollutants↗
PubMed1992

Pulmonary effects of exposure to fine fibreglass: irregular opacities and small airways obstruction.

OBJECTIVE: Man made mineral fibres imitate asbestos and produce tumours of the pleura in animals. To answer the question, Does prolonged exposure to fibreglass adversely affect pulmonary function or produce radiographic abnormalities in human subjects? we studied workers in a midwestern appliance plant where refrigerator doors and previously entire cabinets were insulated with fibreglass sheeting and loose rotary spun fibreglass. METHODS: Spirometry and lung volumes were measured, respiratory and occupational questionnaires were administered, and chest x-ray films were read for pneumoconiosis using International Labour Office (ILO) 1980 criteria in 284 workers with exposure of 20 years or more. RESULTS: Expiratory flows were reduced including FEV1 (mean 90.3% of predicted (pr), FEF25-75 (85.5% pr), and FEF75-85 (76.2% pr). Forced vital capacity was significantly reduced (92.8% pr) and total lung capacity was significantly increased (109.2% pr). In white male smokers, a group large enough for comparisons, parameters of pulmonary function were reduced further in the presence of irregular opacities. Forty three workers (15.1%) had evidence of pneumoconiosis on chest radiographs: 26 of these (9.1%), had no known exposure to asbestos and 17 (6.0%) had some exposure. The best judgement was that in 36 (13.0%), pulmonary opacities or pleural abnormalities were due to fibreglass. CONCLUSION: Commercial rotary spun fibreglass used for insulating appliances appears to produce human disease that is similar to asbestosis.

Asthma↗
PubMed1992

Are hearing loss and balance dysfunction linked in construction iron workers?

The objective was to determine whether an association existed between hearing loss and balance dysfunction in construction workers exposed to noise. Screening pure tone audiometry and balance testing were performed using a sound emitter and dual microphone system to evaluate 78 iron workers who were compared with 128 histology technicians. Most iron workers showed hearing loss at frequencies below 3000 Hz. Their sway speeds were significantly faster both with the eyes open (1.05 (SD 0.39) v 0.91 (SD 0.22) cm/s) and with eyes closed (1.66 (SD 0.82) v 1.31 (SD 0.51) cm/s) than those of histology technicians. Coefficients for sway speed with the eyes closed and hearing loss in the left ear were significantly correlated at 500 to 8000 Hz. They were also correlated with the sway speed, eyes open, at low and high Hz. It is concluded that the use of air impact power tools in an inordinately noisy work environment makes iron workers prematurely deaf and impairs their balance. Falls may be related to balance dysfunction and impaired equilibrium. Falls from height injure and kill iron workers. Further investigations will determine whether injuries from falls are linked to these impairments.

Accidental Falls↗
PubMed1992

Predictive equations for total lung capacity and residual volume calculated from radiographs in a random sample of the Michigan population.

BACKGROUND: Published predicted values for total lung capacity and residual volume are often based on a small number of subjects and derive from different populations from predicted spirometric values. Equations from the only two large studies gave smaller predicted values for total lung capacity than the smaller studies. A large number of subjects have been studied from a population which has already provided predicted values for spirometry and transfer factor for carbon monoxide. METHODS: Total lung capacity was measured from standard posteroanterior and lateral chest radiographs and forced vital capacity by spirometry in a population sample of 771 subjects. Prediction equations were developed for total lung capacity (TLC), residual volume (RV) and RV/TLC in two groups--normal and total. Subjects with signs or symptoms of cardiopulmonary disease were combined with the normal subjects and equations for all subjects were also modelled. RESULTS: Prediction equations for TLC and RV in non-smoking normal men and women were square root transformations which included height and weight but not age. They included a coefficient for duration of smoking in current smokers. The predictive equation for RV/TLC included weight, age, age and duration of smoking for current smokers and ex-smokers of both sexes. For the total population the equations took the same form but the height coefficients and constants were slightly different. CONCLUSION: These population based prediction equations for TLC, RV and RV/TLC provide reference standards in a population that has provided reference standards for spirometry and single breath transfer factor for carbon monoxide.

Adult↗
PubMed1992

Severity of pulmonary asbestosis as classified by International Labour Organisation profusion of irregular opacities in 8749 asbestos-exposed American workers. Those who never smoked compared with those who ever smoked.

The profusion of irregular opacities on chest roentgenograms by International Labour Organisation pneumoconiosis criteria was used to assess the severity of asbestosis in 8749 asbestos-exposed active and retired American workers. Seventy-eight percent had no asbestosis (category 0/0 or 0/1), 18.6% had slight asbestosis (1/0 to 1/2), 3% had moderate asbestosis (2/1 to 2/3), and 0.3% had advanced disease (3/2 or greater). Significantly more current smokers had asbestosis than did those who had never smoked, and their average profusion of opacities was higher. The mean age of current smokers with asbestosis was 60 years, whereas subjects with the disease who had never smoked had a mean age of 64 years, a significant difference. Cigarette smoking and asbestosis appear to act synergistically to produce irregular opacities on chest roentgenograms of asbestos-exposed American workers.

Asbestosis↗
PubMed1991

Difficulties of attribution of effect in workers exposed to fiberglass and asbestos.

Man-made mineral fibers have many properties of asbestos that raise concern about their safety. We studied 175 fiberglass production workers, using chest radiographs, measurement of total lung capacity, chest examinations, and occupational and medical histories. Pulmonary volumes and flows were calculated as percent of predicted, adjusted for height, age, ethnicity, and cigarette smoking. Thirty-one men with radiographically evident small irregular opacities of profusion of 1/0 or greater and/or pleural abnormalities were observed. Eight of 38 men with such changes said they had been exposed only to fiberglass; the other 23 with radiologically detectable pleural and/or pulmonary changes were among the 137 whose histories indicated that they had been exposed to asbestos and to fiberglass. Pulmonary function measurements as group means were reduced in the 175: FVC was 94.8% predicted, FEV1 was 91.3% predicted, FEF25-75 was 80.7% predicted, FEF75-85 was 73.1% predicted and FEV1/FVC was 0.73. Total lung capacity (TLC) was elevated to 114.2% predicted (mean) and RV/TLC (mean 0.46) was also elevated. Although only 78% of fiberglass production workers gave histories of asbestos exposure, all had shared the air in a manufacturing plant where ovens insulated with asbestos were continuously cleaned, repaired, dismantled, and rebuilt. It appears that attribution of the effects of their exposure to fiberglass could not be estimated independently of the effects of asbestos exposure.

Adult↗