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Biomedical subjects

R S Bernstein

Publications and source records attributed to R S Bernstein.

At least 19 recordsLinked to original sources
PubMed1991

Pulmonary health risks among northwest loggers.

Spirometry, respiratory symptom questionnaires, and chest radiographs were obtained from 688 loggers in Oregon and Washington. These were compared against previously published National Institute for Occupational Safety and Health studies of nonexposed blue-collar workers to determine if these predictions fit our population. The loggers forced expiratory volume in 1 second and forced vital capacity values were significantly greater than predicted, and their forced expiratory volume in 1 second/forced vital capacity values were less than predicted. The only consistent difference in symptoms between the sample and reference populations was for recent chest illnesses, which were more prevalent in the loggers than in the reference population. The chest radiographs showed a small excess of pleural thickening that we believe is most likely due to chest trauma. We conclude that the National Institute for Occupational Safety and Health studies spirometry prediction equations may not be generalized to other blue-collar populations.

Aged↗
PubMed1991

A new approach to serial monitoring of ultra-high frequency hearing.

Early detection of drug-induced hearing loss is best accomplished by monitoring hearing at the ultra-high frequencies. Unfortunately, at these frequencies, sound pressure at the tympanic membrane (TM) critically depends on the placement of the sound source and on the size and shape of each individual external ear. Thus, presentation of the same sound may yield substantially different sound pressures in different ears. Moreover, only a slight change in the position of an earphone may yield large changes in sound pressure at the tympanic membrane. As a consequence of these characteristics, the reliability of ultra-high-frequency audiometry is poorer than at conventional audiometric frequencies. However, for the early detection of ototoxicity, it is necessary only to monitor for increases in thresholds. Accordingly, a sound-delivery system was developed which fixes the relative position of the sound source and the ear. This system ensures that sounds at the same level may be presented during different test sessions. To assess the stability of ultra-high-frequency thresholds, normal hearing subjects were tested in sessions separated by several weeks. Thresholds were obtained between 1 and 16 kHz and were found to be reliable. It is concluded that this type of system can be used for monitoring the ototoxic effects of drug therapy.

Acoustics↗
PubMed1990

The effects of bandwidth on the detectability of narrow- and wideband signals.

The effects of masker bandwidth on the detection of narrow- and wideband signals have been investigated. For both kinds of signals, plots of threshold as a function of masker bandwidth yielded by both narrow- and wideband signals are reasonably described with two intersecting lines. Threshold initially increase with masker bandwidth and then become independent of further increases. The rate of increase depends on the signal spectrum. The bandwidth at which the lines intersect varies with signal bandwidth and also mode of masker presentation (i.e., whether the masker is gated with the signal or is present continuously). Internal filtering is most accurate when the masker is present continuously. A model is proposed in which a listener's decisions about the presence of narrow-band signals are based upon estimates of stimulus energy within a critical band. These estimates are degraded by bandwidth-dependent processing errors. When the signal to be detected spans several critical bands (i.e., is wideband), the model forms a test statistic by summing the outputs of the relevant critical bands. The model permits the contribution of each band to the sum to vary with masker bandwidth because it incorporates a form of lateral suppression. Thresholds of narrow-band signals in gated maskers and wideband signals in gated and continuous maskers are predicted by the model. However, the model fails to account for the detectability of narrow-band signals in continuous maskers.

Attention↗
PubMed1990

A method for determining hearing sensitivity in infants: the interweaving staircase procedure (ISP).

A computer-assisted adaptive (staircase) threshold acquisition procedure (the ISP) has been developed to determine hearing sensitivity of infants. A visually-reinforced head turn procedure is utilized. Thresholds at three frequencies are obtained with independent and concurrent staircases. Thus, motivation and attention to the task are the same for the three test frequencies. On each trial, the test frequency is randomly selected and then presented at a level determined by the response history at that frequency. The use of Probe and Catch trials permit learning and motivation to be continuously monitored. In the event of marked changes in motivation or attention, trial-by-trial history allows threshold estimates to be adjusted.

Acoustic Stimulation↗
PubMed1988

Estimation of human dose of staphylococcal enterotoxin A from a large outbreak of staphylococcal food poisoning involving chocolate milk.

An outbreak of gastroenteritis in a school district in the United States was determined to be staphylococcal food poisoning due to 2% chocolate milk containing staphylococcal enterotoxin A (SEA). Twelve one-half pint (approx 0.28 l) cartons of the 2% chocolate milk from this outbreak were analyzed for the quantity of SEA present in the milk. The amount of SEA in the cartons varied from 94 to 184 ng with the average being 144 ng (mean = 139 +/- 45). The attack rate for vomiting among those who consumed more than one carton was greater (38.3%) than among those who consumed only one carton (31.5%) with the highest attack rate among those who consumed three or more cartons (44.4%).

Animals↗
PubMed1988

Otitis media, auditory sensitivity, and language outcomes at one year.

The relationship among otitis media, auditory sensitivity, and emerging language was examined in a group of 1-year-old children who were prospectively followed since birth. Pneumatic otoscopy was used to document the otologic status of the children's ears at each medical visit. There were 13 babies with normal ratings in each ear at 80% more of their visits (designated as "otitis free") and 12 babies with bilaterally positive otoscopy results at 30% or more of their first year visits (designated "otitis positive"). In comparison to the otitis free infants, the group of otitis positive babies demonstrated reduced auditory sensitivity as measured by auditory brain stem response (ABR) and poorer expressive language abilities. However, differences in receptive language were not detected. These results suggest that otitis media may have an impact on auditory sensitivity and developing language as early as 1 year of age.

Audiometry, Evoked Response↗
PubMed1987

Obesity and serum lipids: an evaluation of the relative contribution of body fat and fat distribution to lipid levels.

The association of obesity and hyperlipidemia does not mean that fatness per se is the primary determinant of the lipid abnormality. To evaluate the contribution of fatness to fasting levels of serum triglycerides (TG), LDL cholesterol (LDL-C), and HDL cholesterol (HDL-C), we analyzed data on 368 caucasian adults (286 women, 82 men) consecutively entering a weight control program. Although most subjects were overweight, the population represented a wide spectrum of body weights and lipid levels. Study variables included body fat mass (by total body water), fat free mass (FFM), body build (chest to height ratio), fat cell size and number (from bilateral buttock biopsy specimens), upper-lower body fat pattern by arm to thigh circumference ratio, central-peripheral fat pattern by subcapsular to triceps skinfold ratio, waist to hip ratio, and the presence or absence of diabetes. Our results concurred with previously noted correlations of body weight with TG (r = 0.29, P less than 0.0001) and with HDL-C (r = -0.28, P less than 0.0001) at least in the larger sample of women, but there was no significant correlation with LDL-C (r = -0.06). In order to evaluate the relative contribution of the various components of body composition and fat distribution to lipid levels, stepwise regression analyses were performed on the subgroups of women and men. Among women: TG level was predicted best by FFM, upper body fat pattern, age, and diabetes (explaining 30 percent of TG variance); LDL-C level was predicted by age only (explaining 12 percent of variance); and HDL-C level was predicted by body build only (8 percent). Among men: TG level was predicted best by central and upper body fat patterns and diabetes (31 percent of variance); LDL-C and HDL-C levels were not significantly predicted by any of the 11 study variables. These results, obtained from cross-sectional analysis of a predominantly obese sample, suggest that lipid levels may be more directly related to body fat pattern, fat free mass and body build than to body fatness itself.

Adipose Tissue↗
PubMed1986

A four-year prospective study of the respiratory effects of volcanic ash from Mt. St. Helens.

This report describes the 4-yr follow-up of 712 loggers exposed over an extended period to varying levels of fresh volcanic ash from the 1980 eruptions of Mt. St. Helens. Concerns related to the irritant effect the ash might have on the airways and also to its fibrogenic potential if exposures were intense and continued over many years. Our subjects were divided into 3 groups: high, low, and no exposure. Baseline testing was begun in June 1980, 1 month after the major eruption, and follow-up testing continued on an annual basis through 1984; 88% of the loggers have been tested at least 3 times. Analysis of lung function data showed that a significant, exposure-related decline in FEV1 occurred during the first year after the eruption. The decline was short-lived, however, and by 1984 the differences between exposure groups were no longer significant. Self-reported symptoms of cough, phlegm, and wheeze showed a similar pattern. No ash-related changes were seen in chest roentgenograms taken in 1980 and in 1984. Our findings are consistent with the hypothesis that the inhaled ash caused mucus hypersecretion and/or airway inflammation that reversed when the exposure levels decreased. The ash levels to which the loggers were exposed were low compared with permissible occupational levels for nuisance dusts, but generally higher than the total suspended particulate levels permissible in ambient air.

Adolescent↗
PubMed1986

Immediate public health concerns and actions in volcanic eruptions: lessons from the Mount St. Helens eruptions, May 18-October 18, 1980.

A comprehensive epidemiological evaluation of mortality and short-term morbidity associated with explosive volcanic activity was carried out by the Centers for Disease Control in collaboration with affected state and local health departments, clinicians, and private institutions. Following the May 18, 1980 eruption of Mount St. Helens, a series of public health actions were rapidly instituted to develop accurate information about volcanic hazards and to recommend methods for prevention or control of adverse effects on safety and health. These public health actions included: establishing a system of active surveillance of cause-specific emergency room (ER) visits and hospital admissions in affected and unaffected communities for comparison; assessing the causes of death and factors associated with survival or death among persons located near the crater; analyzing the mineralogy and toxicology of sedimented ash and the airborne concentration of resuspended dusts; investigating reported excesses of ash-related adverse respiratory effects by epidemiological methods such as cross-sectional and case-control studies; and controlling rumors and disseminating accurate, timely information about volcanic hazards and recommended preventive or control measures by means of press briefings and health bulletins. Surveillance and observational studies indicated that: excess in morbidity were limited to transient increases in ER visits and hospital admissions for traumatic injuries and respiratory problems (but not for communicable disease or mental health problems) which were associated in time, place, and person with exposures to volcanic ash; excessive mortality due to suffocation (76 per cent), thermal injuries (12 per cent), or trauma (12 per cent) by ash and other volcanic hazards was directly proportional to the degree of environmental damage--that is, it was more pronounced among those persons (48/65, or about 74 per cent) who, at the time of the eruption, were residing, camping, or sightseeing (despite restrictions) or working (with permission) closer to the crater in areas affected by the explosive blast, pyroclastic and mud flows, and heavy ashfall; and de novo appearance of ash-related asthma was not observed, but transient excesses in adverse respiratory effects occurred in two high-risk groups--hypersusceptibles (with preexisting asthma or chronic bronchitis) and heavily exposed workers. Laboratory and field studies indicated that: volcanic ash had mild to moderate fibrogenic potential, consisting of greater than 90 per cent (by count) respirable size particles which contained 4-7 per cent (by weight) crystalline free silica (SiO2).(ABSTRACT TRUNCATED AT 400 WORDS)

Air↗
PubMed1986

Preventive health measures in volcanic eruptions.

Medical treatment has only a small role in severe volcanic eruptions and so preventive measures are paramount if injuries and loss of life are to be reduced. The health team must be incorporated in emergency planning and response at the earliest stage. Guidance on the interpretation of geological information about a volcano and the appropriate health measures that should be adopted before and after an eruption are summarized for the benefit of health workers.

Air↗
PubMed1986

Serum insulin and blood pressure in an obese population.

Serum insulin has been implicated as a determinant of blood pressure (BP) level in obese hypertensive individuals. We examined the relationships among fasting insulin, mean arterial pressure (MAP), body composition, and fat distribution in 204 subjects unselected for glucose tolerance. All met the criteria of taking no oral hypoglycemic agents, insulin or antihypertensive medications. 95 percent were considered obese and 78 percent were female. Mean age was 39 years (range 15-71), percent ideal body weight (IBW) 171 percent (109-332), BP 125/81 mmHg (80-181/50-110) and fasting insulin 44 microU/ml (4-196). Lean body mass (LBM) and body fat were measured by tritium dilution. The correlation coefficient between insulin and MAP was 0.32 (P less than 0.0001). Both insulin and MAP correlated highly with percentage IBW, percentage body fat, fat mass, LBM, body build and upper fat pattern. Controlling for these variables simultaneously eliminated the association between insulin and BP. By contrast, the correlations between MAP and measures of body composition and fat distribution retained significance after controlling for insulin level. These findings suggest that measures of body composition and fat distribution have a relationship with BP that is not entirely accounted for by serum insulin level, and the relationship between serum insulin and BP is indirect and largely accounted for by their mutual association with measures of body composition and fat distribution.

Adipose Tissue↗
PubMed1984

Inhalation exposure to formaldehyde: an overview of its toxicology, epidemiology, monitoring, and control.

Increasing production and use of formaldehyde in consumer products have resulted in widespread recognition of its acute irritant effects at exposure levels below the current occupational health standard [3 parts per million parts of air (ppm)]. Formaldehyde is an allergic (immunologically mediated) skin sensitizer which may also cause or exacerbate respiratory distress in individuals with preexisting or formaldehyde-induced bronchial hyperreactivity. Formaldehyde gas is a very reactive alkylating agent which is mutagenic in several in vitro test systems. At exposure levels less than one order of magnitude greater than those often found in human occupational and nonoccupational environments, it induces squamous cell carcinomas in the nasal cavity of rats. Recent reviews suggest that formaldehyde exposure should be treated as though it poses a carcinogenic risk to humans and should be reduced to the lowest feasible level. This report reviews information on the epidemiologic evaluation of health effects which may result from hazardous levels of exposure to formaldehyde. Methods for monitoring exposure are discussed in detail because of considerable diversity in the methods used by state health departments for recognition, evaluation and control of nonoccupational exposures. Current guidelines for the evaluation and control of exposures to formaldehyde gas are suggested.

Acute Disease↗