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Biomedical subjects

E L Petsonk

Publications and source records attributed to E L Petsonk.

29 records · Page 2Linked to original sources
PubMed1995

Comparing MiniWright and spirometer measurements of peak expiratory flow.

The accuracy and instrument variability of the MiniWright (Clement Clarke) peak expiratory flow (PEF) meter was determined with 6 of the 24 American Thoracic Society's (ATS) standard waveforms using a mechanical pump. Both room air and air heated to 37 degrees C and saturated with water vapor were used. In addition, MiniWright-determined PEF measurements were compared with those obtained using a dry rolling-seal spirometer (Ohio No. 822; Ohio Medical Products; Madison, Wis) from 75 subjects on 2 different days. The MiniWright average coefficient of variation within a waveform was found to be 2.8%. Results using heated and humidified air (body temperature, ambient pressure, and saturated with water: body conditions) were 2.5% lower than those obtained using room air. Comparisons with mechanically simulated PEF and with spirometry-determined peak flow in 75 human subjects showed that MiniWright meters over-estimated flows at lower flow rates and slightly under-estimated flows at higher flow rates. These results suggest that the new "mechanical PEF" MiniWright scale should be used instead of the "traditional" MiniWright scale.

Evaluation Studies as Topic↗
PubMed1994

BTPS correction for ceramic flow sensor.

Several commercially available spirometers use unheated ceramic elements as flow sensors to determine flow and calculate volume of air. The usual method of correcting the resulting flow and volume values to body temperature pressure saturated (BTPS) is to apply a constant factor approximately equal to 30 percent of the full BTPS correction factor. To evaluate the usual BTPS correction factor technique, we tested several sensors with a mechanical pump using both room air and air heated to 37 degrees C and saturated with water vapor. The volume signals used to test the sensors were volume ramps (constant flow) and the first four American Thoracic Society (ATS) standard waveforms. The percent difference in FEV1 obtained using room vs heated-humidified air (proportional to the magnitude of the BTPS correction factor needed) ranged from 0.3 percent to 6.2 percent and varied with the number of maneuvers previously performed, the time interval between maneuvers, the volume of the current and previous maneuvers, and the starting temperature of the sensor. The temperature of the air leaving the sensor (exit temperature) showed a steady rise with each successive maneuver using heated air. When six subjects performed repeated tests over several days (each test consisting of at least three maneuvers), a maneuver order effect was observed similar to the results using the mechanical pump. These results suggest that a dynamic, rather than static, BTPS correction factor is needed for accurate estimations of forced expiratory volumes and to reduce erroneous variability between successive maneuvers. Use of exit air temperature provides a means of estimating a dynamic BTPS correction factor, and this technique may be sufficient to provide an FEV1 accuracy of less than +/- 3 percent for exit air temperatures from 5 degrees to 28 degrees C.

Body Temperature↗
PubMed1993

Organic dust exposure from compost handling: response of an animal model.

The objective of this investigation was to elucidate the pulmonary responses of an animal model to dust generated from leaf/wood compost which had caused a severe case of acute respiratory illness in an individual. Guinea pigs were exposed for 4 hr to 30 mg/m3 of aerosolized leaf/wood compost dust. Inhalation resulted in significant cellular activation and changes in pulmonary mechanics. Maximal elevation in breathing rate (increases 36%) was observed 12-18 hr postexposure. Similarly, maximal granulocyte infiltration (increases 1,600%) and activation of alveolar macrophages (increases 65%) occurred 18 hr postexposure. In contrast, maximal airway obstruction (increases 120%) occurred immediately after exposure and returned toward normal (increases 53%) by 18 hr postexposure. In several respects, the airway obstruction and pulmonary inflammation described in the animal model were comparable to the human response to compost dust. Therefore, this animal model may be useful in predicting the potential respiratory hazard associated with exposure to various organic dusts.

Agriculture↗
PubMed1988

Pneumoconiosis in carbon electrode workers.

Pneumoconiosis was diagnosed in five workers involved in the manufacture of carbon electrodes. Possible etiologies are discussed. It is generally believed that pneumoconiosis ceased to be a problem in this industry after World War II; however, the reported cases all resulted from exposures after 1940. These findings question the efficacy of recent and current engineering controls and suggest the need for further study of this industry.

Carbon↗
PubMed1986

Human ventilatory response to washed and unwashed cottons from different growing areas.

Thirty volunteer subjects were exposed to controlled amounts of respirable dust generated by the carding of cotton in an experimental cardroom. Eighteen exposures each lasting six hours were performed while carding unwashed and washed cottons from the three major growing regions of the United States. Elutriated dust was analysed gravimetrically and was comparable (0.59 mg/m3 +/- 0.04) for all exposures. Spirometry was recorded before and after each exposure. California cotton resulted in a significantly smaller fall in FEV1 than cotton of the same grade from Texas or Mississippi. All washed cottons resulted in reduced declines when compared with unwashed cottons. For 17 subjects breathing zone personal total dust samples were analysed for airborne endotoxin and compared with the individual's pulmonary function response. A significant correlation between endotoxin exposure and acute decrease in FEV1 was seen. The effect on FEV1 per nanogram of airborne endotoxin was greater for Mississippi cotton than for cotton from the other regions. Airborne endotoxin appears to be an important determinant of acute pulmonary effects of cotton dust. Water washing of cotton results in reduced airborne endotoxin and less bronchoconstriction.

Byssinosis↗
PubMed1983

Physiologic effects of a self-contained self-rescuer.

Recently promulgated federal regulations mandate the provision of an emergency, self-contained, oxygen-supplying breathing device (self-contained self-rescuer, SCSR) to all underground coalminers. In order to assist in defining the potential limitations of this new device, we measured the responses of ten healthy coal mine inspectors to submaximal steady-state treadmill exercise with and without the SCSR. During the last minute of exercise, blood oxygen saturation averaged 98.3% and mouth pressure swing 15.6 cm H2O with the device, compared to 94.8% and 10.4 cm H2O without it. Mean respiratory rates were decreased to 25/min with the SCSR from 28/min without it. Blood pressure, core temperature and heart rate were unaffected. We conclude that in healthy individuals on submaximal exercise there is little evidence of a significant adverse effect of the new device.

Adult↗
PubMed1983

Transbronchial biopsy of pulmonary alveolar microlithiasis.

A middle-aged woman was initially seen with mild breathlessness and a fine reticulonodular pattern noted on chest roentgenogram. Pulmonary alveolar microlithiasis was demonstrated by transbronchial biopsy. Although microlithiasis calcispherites have been described as appearing in bronchial walls, at necropsy, and in lavage fluid, we have found only one previous report of a case diagnosed by transbronchial biopsy.

Biopsy↗
PubMedDate not supplied

Couriers of asthma: antigenic proteins in natural rubber latex.

Natural rubber latex (NRL) is a milky, white liquid containing the polymer cis-1,4-polyisoprene, derived from the laticifer cells of the rubber tree, Hevea brasiliensis. Reports of allergic reactions to NRL, ranging in severity from skin rashes to anaphylaxis and death, have been increasing. High rates of latex allergy are seen in children with spina bifida. Healthcare workers, especially those who frequently use powdered latex medical gloves, can develop NRL allergy and asthma, often resulting in considerable disability. Atopy and, possibly, pre-existing dermatitis predispose to sensitization and allergic symptoms. NRL protein antigens are found in many NRL products and also have been shown to bind to cornstarch glove-donning powders. Of the approximately 240 polypeptides in NRL, nearly 60 are antigenic, and nine have been identified and registered (Hev b 1&ndash9). Many natural latex antigens share epitopes with structural proteins and enzymes from other plant species. Current knowledge indicates that proposed reductions in total glove protein and limitations on the use of powder on NRL gloves are likely to result in a decline in the prevalence and severity of NRL allergies among healthcare workers.

Antigens↗
PubMedDate not supplied

Respiratory health risks among nonmetal miners.

The risks of occupational respiratory disease faced by nonmetal miners are the focus of this review. An understanding of the respiratory risks requires an understanding of the minerology of the ground and rock around the materials being mined. Relevant exposures encompass radon gas and deisel fumes, as well as mineral and rock dusts, including free silica. The types of materials mined and their associated health effects are examined, including the silicates (fibrous silicates such as asbestos, asbestiform fibrous minerals such as wollastonite and fuller's earth, and nonfibrous silicates such as talc and kaolin), sedimentary precipitates such as phosphates, potash, gypsum, and salt, as well as hydrocarbon-containing sedimentary rock such as oil shale.

Humans↗