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Biomedical subjects

B S Cohen

Publications and source records attributed to B S Cohen.

At least 37 records · Page 2Linked to original sources
PubMed1986

The effect of aerosol on estimates of inhalation exposure to airborne styrene.

Exposure to volatile organic contaminants usually is attributed to vapors alone; samples are collected on charcoal tubes or by passive dosimeters. This study demonstrated that aerosols, generated during the spraying of polyester resin solution, can contribute significantly to the exposure to volatile organic contaminants. Four spraying experiments were performed during which 64 samples were collected and analyzed to determine the styrene air concentrations. The results from the four spraying experiments showed that aerosols represented 30% +/- 3% of the total air concentration of styrene. The contribution of aerosols to inhalation exposure needs to be considered in other industrial situations where spray processes are used.

Aerosols↗
PubMed1986

Superior vena caval blood flow velocities in adults: a Doppler echocardiographic study.

Superior vena caval blood flow velocity was measured in 30 normal adults (age 20-65, mean 36 yr). The flow velocities were measured by pulsed Doppler echocardiography, using a Duplex system with the transducer at the right supraclavicular fossa, approximating a 0 degrees Doppler angle. Four distinct flow waveforms were found during each cardiac cycle: A, a small retrograde flow during right atrial contraction (peak flow velocity 12.4 +/- 2.2 cm/s); B, a small antegrade flow during right atrial relaxation (15.7 +/- 5.0 cm/s); S, a large antegrade flow during ventricular systole (35.2 +/- 7.3 cm/s); and D, a large antegrade flow during ventricular diastole (23.2 +/- 3.1 cm/s). The wave duration was inversely related to heart rate. The peak flow velocities of the S and D waves were inversely related to the patients' ages. This study provides recognition of the pattern and range of normality essential to extension of this noninvasive technique to the diagnosis of pathological conditions.

Adult↗
PubMed1985

Clearance of polonium-210-enriched cigarette smoke from the rat trachea and lung.

The distribution and clearance of alpha radioactivity in the lungs of rats were measured after inhalation of smoke from cigarettes highly enriched in 210Po. Female Fischer rats were exposed daily for 6 months to smoke from cigarettes with 500 times the normal content of 210Po. Control rats were exposed to standard cigarette smoke. Animals were serially withdrawn and killed. After necropsy the trachea, major bronchi, larynx, and nasopharynx were examined for surface alpha activity by an etched track technique utilizing cellulose nitrate detectors. Areas of accumulated activity were seen on samples of larynx from rats exposed to the 210Po-enriched cigarettes. No other local accumulations were seen on the airways. The lower lungs were analyzed radiochemically for 210Po. Both radiochemical analysis and track measurements showed highly elevated activity concentrations in rats exposed to the 210Po-enriched cigarettes. Following withdrawal from smoking, both short- and long-term clearance components were seen. The parameters which fit the postexposure data for clearance of the lung burden cannot fit the buildup during the exposure period.

Animals↗
PubMed1985

Normalization of venous pH, pCO2, and bicarbonate levels after blockade of panic attacks.

Recent evidence suggests that hyperventilation may be associated with spontaneous panic attacks in patients with panic disorder. This is reflected in abnormal patterns of blood gas and blood pH levels in these patients. In this study, absolute levels and variances of pH, pCO2, and bicarbonate were compared between controlled patients before and after successful pharmacological treatment. The results indicate that successful treatment of panic disorder results in a normalization of pH, pCO2, and bicarbonate levels.

Adult↗
PubMed1985

Aerosol resuspension from fabric: implications for personal monitoring in the beryllium industry.

The fabric used for work clothing at an industrial site can significantly influence personal monitor (PM) exposure estimates because dust resuspension from clothing can increase the concentration at the sampler inlet. The magnitude of the effect depends on removal forces and on the interaction of the contaminant particles with work garments. Aerosol deposition and resuspension on cotton and Nomex aramid fabrics was evaluated at a beryllium refinery. Electrostatically charged cotton backdrops collected more beryllium than neutral controls, but electronegative Nomex backdrops did not. Moving fabrics collected more beryllium than did stationary controls. When contaminated fabrics were agitated, PMs mounted 2.5 cm in front of the fabric collected more beryllium than monitors above the fabric, positioned to simulate the nose or mouth. The difference between the air concentrations measured by these PMs increased with Be loading and tended to level off for highly contaminated fabric. Cotton resuspended a larger fraction of its contaminant load than Nomex. These results are consistent with current knowledge of the behavior of particles on fabric fibers. Aerosol resuspension from garments is an important consideration in assessing inhalation exposure to toxic dusts. A garment may attract and retain toxic particles. This contamination is then available for later resuspension.

Aerosols↗
PubMed1985

Specificity of lactate infusions in social phobia versus panic disorders.

Lactate infusions produced panic attacks in one of 15 patients with social phobia, four of nine with agoraphobia, and 10 of 20 with panic disorder in a blind study. The proportion of patients with social phobia who panicked in response to lactate was significantly lower than that of patients with agoraphobia or panic disorder. These findings lend validity to the DSM-III classification of anxiety states. They also suggest that the pathophysiology of social phobia differs from that of disorders characterized by spontaneous panic attacks.

Adult↗
PubMed1984

Bias in air sampling techniques used to measure inhalation exposure.

Factors have been evaluated which contribute to the lack of agreement between inhalation exposure estimates obtained by time-weighted averaging of samples taken with mini hi-volume samplers, and those measured by time integrating, low-volume, lapel mounted, personal monitors. Measurements made with real-time aerosol monitors on workers at a Be-Cu production furnace show that part of the discrepancy results from variability of the aerosol concentration within the breathing zone. Field studies of sampler inlet bias, the influences of the electrostatic fields around polystyrene filter holders, and resuspension of dust from work clothing, were done in three areas of a Be plant. No significant differences were found in Be air concentrations measured simultaneously by open and closed face cassettes, and "mini hi-volume" samplers mounted on a test stand. No significant influence on Be collection was detected between either positively or negatively charged monitors and charge neutralized control monitors. The effect of contaminated work clothing on dust collection by lapel mounted monitors is most important. Beryllium release from the fabrics affected air concentrations measured by fabric mounted monitors more than it affected concentrations measured by monitors positioned above the fabrics. The latter were placed 16 cm from the vertically mounted fabrics, to simulate the position of the nose or mouth. We conclude that dust resuspended from work clothing is the major source of the observed discrepancy between exposures estimated from lapel mounted samplers and time-weighted averages.

Aerosols↗
PubMed1984

Effects of electrostatic charge on aerosol collection with polystyrene filter cassettes.

Electrostatic fields are present on polystyrene cassette filter holders commonly used to measure the concentration of particles in air. Beryllium concentrations were determined at a beryllium refinery using neutral, and positively and negatively charged cassettes. In laboratory experiments, tobacco smoke, magnetite and polyvinyltoluene latex spheres were collected by both charged and neutral cassettes. No differences in concentration measurements were observed in the experiments at the refinery. In the laboratory experiments, the concentration of a charged negative aerosol collected by a highly charged negative cassette was reduced. Thus, when collecting charged aerosols, the polystyrene cassettes should be charge neutralized.

Aerosols↗
PubMed1984

Geriatric rehabilitation.

Elderly people experience motor, sensory and cognitive losses that affect their mobility and their ability to perform activities of daily living. There is often gradual loss of function, which requires recognition and correction. Sudden events, such as stroke, amputation or trauma, may occur in an environment of diminished function and reserve. Rehabilitation measures must be directed toward prevention of dysmobility, correction of functional losses and provision for continuing aftercare.

Activities of Daily Living↗
PubMed1984

The physiatrist as primary physician for patients on an inpatient rehabilitation unit.

Eighty-two patients admitted to a predominantly geriatric inpatient rehabilitation unit were followed throughout their stay in order to document their need for medical management. Their average age was 74.1 years and mean length of stay was 27.9 days. A total of 302 indications for medical intervention (3.7/patient) were found. In addition there were 2.8 medication changes/patient found when comparing admission to discharge medications, and 0.7 medications/patient prescribed for intercurrent illnesses. Actual documented loss of planned therapy time was found 21 times, involving 19 patients but exceeded 1 day in only six patients. Fifty-eight patients were ultimately discharged home, 14 were discharged to nursing homes (7 for social reasons), and 10 were transferred to an acute general hospital. Adverse drug reactions occurred in 27% of the patients and incidence rate paralleled the number of medications prescribed for the patient. This study indicates that the physiatrist on an inpatient rehabilitation unit must function as team manager or program director, and as the patient's primary physician. By managing medical problems effectively, the physician limits the loss of therapy time, thus shortening the length of stay and enabling the patient to continue to participate in his rehabilitation program.

Aged↗
PubMed1983

Monitoring real-time aerosol distribution in the breathing zone.

A prototype air sampling, data recording, and data retrieval system was developed for monitoring aerosol concentrations in a worker's breathing zone. Three continuous-reading, light-scattering aerosol monitors and a tape recorder were incorporated into a specially designed and fabricated backpack for detailed field monitoring of both temporal and spatial variability in aerosol concentrations within the breathing zone. The backpack was worn by workers in a beryllium refinery. The aerosol which passed through each monitor was collected on a back-up filter for later chemical analysis for Be and Cu. The aerosol concentrations were recorded on magnetic tape as a function of time. The recorded signals were subsequently transcribed onto a strip chart recorder, then evaluated using a microcomputer with graphics capability. Field measurements made of the aerosol concentration at the forehead, nose, and lapel of operators during the melting and casting of beryllium-copper alloy demonstrated that there is considerable variability in concentration at different locations within the breathing zone. They also showed that operations resulting in worker exposure can be identified, and the precise time and duration of exposure can be determined.

Aerosols↗