PubMed Health⌕ Search

Biomedical subjects

J Camp

Publications and source records attributed to J Camp.

47 records · Page 3Linked to original sources

[Paganini].

Explore the source record for details and available documents.

Famous Persons↗

Farmworker exposure to organophosphorus pesticide residues during apple thinning in central Washington State.

The purpose of this study was to characterize worker exposure to azinphos-methyl (Guthion) over an entire 4-6 week apple-thinning season. Twenty workers from three work sites in the Chelan-Douglas County region of Washington state were recruited for the study. Exposure potential was estimated by dislodgeable foliar residue measurements, and individual exposures were estimated by biological monitoring through urinary metabolites. Measureable azinphos-methyl residues were found on apple foliage at all sites throughout the six-week sampling period, indicating continuous exposure potential (median residue level of 0.5 microgram/cm2). Measurable levels of the urinary dialkylphosphate metabolite, DMTP, were found in virtually all urine samples (limit of detection = 0.04 microgram/mL). Mean DMTP concentrations differed significantly across sites (0.53, 0.29, and 0.90 microgram/mL for Sites 1-3, respectively; analysis of variance, p < .002), and intraindividual variability was much greater than interindividual differences. Group mean DMTP concentrations at each site fluctuated according to foliar residue levels. Measurable DMTP concentrations were found in 9% of reference workers, ranging from 0.04-0.18 microgram/mL. Cholinesterase activity levels monitored with a field test kit were not considered reliable due to temperature changes of the instrument.

Adolescent↗

An assessment of occupational noise exposures in four construction trades.

Three hundred thirty-eight noise exposure samples were collected from 133 construction workers employed in 4 construction trades: carpenters, laborers, ironworkers, and operating engineers. Four sites using a variety of construction techniques were sampled at least 12 times on a randomly chosen date over a 22-week period. Up to 10 volunteer workers were sampled for an entire work shift on each sampling day using datalogging noise dosimeters, which recorded both daily time-weighted averages (TWAs) and 1-min averages. Workers also completed a questionnaire throughout the workday detailing the tasks performed and tools used throughout the day. Regression models identified work characteristics associated with elevated exposure levels. Comparisons were made between exposures measured using the Occupational Safety and Health Administration (OSHA) exposure metric and the 1996 draft National Institute for Occupational Safety and Health/International Organization for Standardization (NIOSH/ISO) metric to examine the effects of differing exchange rates and instrument response times on construction noise exposures. The mean OSHA TWA for 338 samples was 82.8 dBA +/- 6.8 dBA, whereas the mean NIOSH/ISO TWA for 174 samples was 89.7 dBA +/- 6.0 dBA. Forty percent of OSHA TWAs exceeded 85 dBA, and 13% exceeded 90 dBA, the OSHA permissible exposure limit. The tasks and tools associated with the highest exposure levels were those involving pneumatically operated tools and heavy equipment. Trade was a poor predictor of noise exposure; construction method, stage of construction, and work tasks and tools used were found to be better exposure predictors. An internal validation substudy indicated excellent agreement between worker self-reporting and researcher observation. These data provide substantial documentation that construction workers in several key trades are frequently exposed to noise levels that have been associated with hearing loss, and demonstrate the need for targeted noise reduction efforts and comprehensive hearing conservation programs in the industry.

Humans↗

Noise exposure among construction electricians.

Data-logging noise dosimetry was used to assess the exposure levels of electricians working for a major electrical subcontractor in Washington State at five sites using four types of construction methods. Subjects documented activities and work environment information throughout their work shift, resulting in an activity/exposure record for each of the 174 full-shift samples collected over the 4-month duration of the study. Over 24% of the TWA samples exceeded 85 dBA; 5.2% exceeded the federal Occupational Safety and Health Administration permissible exposure limit of 90 dBA. The National Institute for Occupational Safety and Health exposure metric, which specifies a 3-dB ER, was also utilized; using this metric, 67.8% of the samples exceeded 85 dBA and 27% exceeded 90 dBA. Subjects were directly observed for a subset of 4469 min during which more detailed activity and environmental information was recorded. Linear and logistic regression models using this subset were used to identify the determinants of average exposure, and exposure exceedences, respectively. These models demonstrated the importance of multiple variable modeling in interpreting exposure assessments, and the feasibility and utility of modeling exposure exceedences using logistic regression. The results further showed that presumably quiet trades such as electrician are at risk of exposure to potentially harmful noise exposures, and that other workers' activities and the general environment contribute substantially to that risk. These results indicate that noise control strategies will have to address the construction work environment as an integrated system.

Adult↗

Alteration of Baumann's angle by humeral position: implications for treatment of supracondylar humerus fractures.

To determine the effects of limb positioning on Baumann's angle, we made a controlled radiographic study of a 6-year-old cadaver upper extremity specimen. Radiographic measurement of Baumann's angle was obtained at 10 degrees increments of humeral rotation from 40 degrees of internal rotation to 40 degrees of external rotation. These measurements were obtained with the humerus parallel to the x-ray cassette and with the humerus flexed 30 degrees from the cassette. Measurement of Baumann's angle with radiographs obtained with the humerus parallel to the x-ray cassette was associated with less variation in the measured angle (6 degrees of change for every 10 degrees of rotation). The relevance of these findings in management of supracondylar fractures is discussed.

Biomechanical Phenomena↗

Comparison of inpatient and outpatient traction in developmental dislocation of the hip.

We studied 83 hips in 72 children being treated for developmental hip dislocation to assess the influence of home traction upon the incidence and severity of avascular necrosis (AVN). We compared two types of traction prior to closed or open reduction: inpatient Bryant's skin traction (40 hips), and outpatient (home) Bryant's skin traction (43 hips). No routine in-traction radiographs were taken in either group. After traction, a stable closed reduction was achieved in 55 hips (66%). Open reduction was performed on 28 hips (34%). The rate of severe AVN involving growth disturbance and resultant deformity (Bucholz types II, III, and IV) was low in both traction groups (inpatient, three out of 40, outpatient, one out of 43). These results demonstrate that an outpatient traction program without attention to radiographic hip station is as safe as identically instituted inpatient programs, as well as those that emphasize achievement of a traction reduction or a predetermined hip station.

Ambulatory Care↗

Pain after epithelial removal by ethanol-assisted mechanical versus transepithelial excimer laser debridement.

PURPOSE: To compare subjective pain responses between two techniques of epithelial removal prior to photorefractive keratectomy (PRK) treatment: ethanol-soaked pledget with mechanical debridement of the epithelium versus excimer laser transepithelial ablation. METHODS: Nine patients underwent bilateral PRK. Each had the epithelium in one eye debrided by placing a pledget soaked in 20% ethanol on the cornea for 2 minutes followed by gentle scraping with a blade. The epithelium in the other eye was removed by transepithelial phototherapeutic keratectomy (PTK) treatment. For each eye, PRK was initiated immediately after removal of the epithelium. On postoperative day one, each patient was asked to rate the level of pain suffered over the last 24 hours on a scale of 0 (minimal) to 10 (maximal). Data were analyzed in a masked fashion. RESULTS: Postoperative day one average pain level in the ethanol-assisted mechanically debrided eyes was 3.0 +/- 2.5 and in the transepithelial PTK eyes was 6.8 +/- 1.8. The difference was statistically significant by Student's t-test (P < .01). All epithelial defects healed within 3 days with no clinically significant difference in healing time between the two techniques. CONCLUSION: In preparation for PRK, ethanol-assisted mechanical debridement of the epithelium caused significantly less postoperative pain than epithelial removal using the excimer laser.

Adult↗

A multicenter comparison of adhesion, preference, tolerability, and safety characteristics of two transdermal nitroglycerin delivery systems: Transderm-Nitro and Deponit.

One hundred forty-two patients with stable angina were enrolled in a four-week, multicenter, office-based study to compare the adhesion properties, patient preference, and tolerability of two commercially available transdermal nitroglycerin patches. Data from 139 patients were analyzed. Each patient simultaneously wore one 5-mg Transderm-Nitro (TDN) patch and one 5-mg Deponit (DPT) patch. Patients daily recorded the following information in a diary format: number of angina attacks, frequency of sublingual nitroglycerin use, patch adhesion, and problems at the adhesion site or other medical problems. At the end of the study, patients rated their patch preferences based on ease of application and removal, ease of removing backing, overall adhesion, and adhesion under specific conditions, such as showering, swimming, exercise, hot weather, high humidity, and perspiration. They also specified which patch they would choose for their next prescription. Differences in adhesion properties (P less than 0.0001) and tolerability at the site of application favored TDN over DPT. In addition, significantly more patients (P less than 0.0001) specified TDN as their next prescription choice (83% vs 11%).

Adhesiveness↗