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Biomedical subjects

J R Wilson

Publications and source records attributed to J R Wilson.

315 records · Page 18Linked to original sources
PubMedDate not supplied

Characterization of firefighter exposures during fire overhaul.

Previous studies have characterized firefighter exposures during fire suppression. However, minimal information is available regarding firefighter exposures during overhaul, when firefighters look for hidden fire inside attics, ceilings, and walls, often without respiratory protection. A comprehensive air monitoring study was conducted to characterize City of Phoenix firefighter exposures during the overhaul phase of 25 structure fires. Personal samples were collected for aldehydes; benzene; toluene; ethyl benzene; xylene; hydrochloric acid; polynuclear aromatic hydrocarbons (PNA); respirable dust; and hydrogen cyanide (HCN). Gas analyzers were employed to continuously monitor carbon monoxide (CO), HCN, nitrogen dioxide (NO2), and sulfur dioxide (SO2). Area samples were collected for asbestos, metals (Cd, Cr, Pb), and total dust. During overhaul the following exceeded published ceiling values: acrolein (American Conference of Governmental Industrial Hygienists [ACGIH] 0.1 ppm) at 1 fire; CO (National Institute for Occupational Safety and Health [NIOSH] 200 ppm) at 5 fires; formaldehyde (NIOSH 0.1 ppm) at 22 fires; and glutaraldehyde (ACGIH 0.05 ppm) at 5 fires. In addition, the following exceeded published short-term exposure limit values: benzene (NIOSH 1 ppm) at two fires, NO2 (NIOSH 1 ppm) at two fires, and SO2 (ACGIH 5 ppm) at five fires. On an additive effects basis, PNA concentrations exceeded the NIOSH recommended exposure limits (0.1 mg/M3) for coal tar pitch volatiles at two fires. Maximum concentrations of other sampled substances were below their respective permissible exposure limits. Initial 10-min average CO concentrations did not predict concentrations of other products of combustion. The results indicate that firefighters should use respiratory protection during overhaul. In addition, these findings suggest that CO should not be used as an indicator gas for other contaminants found in this atmosphere.

Air Pollutants, Occupational↗
PubMedDate not supplied

Effects of ethanol: II. Behavioral sensitivity and acute behavioral tolerance.

Two doses of ethyl alcohol were administered to 48 young male subjects (24 brother-pairs), and placebo doses were administered to five brother-pairs (controls). Dose 1 amount was calculated to result in a peak blood alcohol content (BAC) of 100 mg/100 ml; dose 2 was given when BAC had fallen to one-half the peak BAC resulting from dose 1, in an attempt to raise BAC back to 100 mg/100 ml. Prior to alcohol dosage, baseline measurements were made on a number of behavioral tests. Behavioral performances during metabolism of doses 1 and 2 were compared to baseline performance. Sensitivity to ethanol was indicated by performance decrements on nearly all tests after ethanol dosing. Acute behavioral tolerance to ethanol (ABTE) was indicated for some tests by improved performance after dose 2 compared to performance at a time after dose 1 when BACs were about equivalent. A preliminary search for possible genetic components of sensitivity and ABTE was undertaken by comparing the scores of the brothers.

Adolescent↗
PubMedDate not supplied

Effects of ethanol: I. Acute metabolic tolerance and ethnic differences.

Forty-five young men were given an initial dose of ethanol calculated to achieve a blood alcohol concentration (BAC) of 100 mg of ethanol/100 ml of blood. Using breath analysis, the rates of ethanol clearance were calculated over a period of a few hours. When each individual reached a BAC level exactly one-half (about 50 mg%) that seen at his peak BAC, he was given a second dose of ethanol amounting to 45% of his initial dose, and the clearance rate was again determined. Estimates of absorption time, peak BAC, volume of distribution, clearance rate, and other metabolic parameters were made separately following each dose of ethanol. As intended, there was no significant difference between peak 1 and peak 2; however, there was a significant increase in clearance rate (beta 60) after dose 2. We term this phenomenon acute metabolic tolerance to ethanol ( AMTE ). When the sample was stratified by ethnicity, there was a trend for men of Oriental ancestry to clear the drug at a faster rate than was the case for men of Caucasian or Polynesian ancestry. The data also indicated that prior drinking history may have had an effect on clearance rate, though this differed by ethnicity. Two different methods for estimating volume of distribution (V) were used. The correlation between the separate estimates obtained was poor, and is probably an indication of the need for development of more accurate methods for estimating V.

Adolescent↗
PubMedDate not supplied

Electrodiagnostic criteria in CIDP: comparison with diabetic neuropathy.

This study examines current criteria for CIDP by comparing the electrodiagnostic data from 17 patients who have biopsy proven CIDP with 29 patients with diabetic neuropathy. The groups were comparable in age. Data were examined using four sets of published criteria for primary demyelination. Two sets (A & B) defined demyelination based on distal motor latencies, F-wave latencies, motor conduction velocities, and temporal dispersion or conduction block. The other two sets defined demyelination based on slowing of motor conduction velocity < 70% of the lower limit of normal (LLN) in either 2 nerves (set C), or in a single nerve (set D). Using set A, 3/17 patients with CIDP met the criteria for a demyelinating neuropathy, while this was true in 2/29 of the patients with diabetic neuropathy. For sets B and C, data consistent with a demyelinating neuropathy were identified in 2/17 and 1/29 patients, respectively. Using set D criteria for demyelination was met in 6/17 of the patients with CIDP and in 5/29 of the diabetic patients. None of the criteria sets showed a significant difference between CIDP and diabetic neuropathy (p = 0.3 to 0.5). Though electrodiagnosis is an important element in the diagnosis of CIDP, current electrodiagnostic criteria alone are insufficient for defining many cases of CIDP.

Adult↗
PubMedDate not supplied

Electrodiagnostic patterns in MGUS neuropathy.

Monoclonal gammopathies of undetermined significance (MGUS) are frequently associated with neuropathies, particularly in the elderly. To better characterize the electrodiagnostic findings in MGUS-associated neuropathies, we analyzed electrodiagnostic data from 35 patients with MGUS-associated neuropathies (mean age 70.6; 12 IgM, 19 IgG, 4 IgA) who had no other cause for their neuropathies. Data was also analyzed for 29 age-matched patients (mean age 69.8) with diabetic neuropathies. Using electrodiagnostic criteria, studies were classified as being consistent with demyelination; 9 patients had findings consistent with axonal injury; and, in 3 patients, criteria for both demyelination and axonal injury were present. However, 24 of the 35 patients with MGUS-associated neuropathies had dyssummetric findings. In contrast, only 4 of the 29 patients with only diabetes had a dyssymmetric process (p < 0.0001). In MGUS-associated neuropathies, dyssymmetry is the most common, definable abnormal electrodiagnostic pattern.

Aged↗