Biomedical subjects

I Weisgerber

Publications and source records attributed to I Weisgerber.

17 recordsLinked to original sources

PubMed1992

The use of neuromuscular blocking agents by air medical services.

Neuromuscular blocking agents (NMBs) are frequently used to facilitate intubations in the hospital. The 1987 membership of the Association of Air Medical Services (AAMS) was surveyed to determine the frequency of NMB use by flight programs both before and after definitive airway control. Out of 141 programs, 101 returned completed survey forms. Of those responding, 39 of 101 used NMBs before intubation, and 67 programs used NMBs after intubation. The use of NMBs in the base hospital by emergency physicians was a significant predictor of the use by the air medical service. No other factors studied, including flight volume, percentage of trauma-related flights, percentage of flights to an accident scene, or the specialty of the service's medical director, predicted use of the agents after intubation. The presence of a physician on the flight crew was associated with the use of succinylcholine prior to definitive airway control. Reported complications included three deaths attributed to use of NMBs in the preceding two years. We conclude that NMBs are commonly used following intubation, and that NMBs are used before intubation by some flight programs, especially those that have physician crew members.

Aircraft↗

PubMed1976

Contributions to ecological chemistry CVII1. Fate of lindane-14C in lettuce, endives and soil under outdoor conditions.

In seven successive outdoor experiments, lindane-14C was applied to lettuce or endive leaves as an aqueous formulation (about 12 mg on 20 plants for each experiment). The growing periods varied between 21 and 37 days. After this time, between 4.5% and 13.9% of the applied radiocarbon was recovered from the plants. Conversion rates to soluble metabolites as well as to unextractable residues appeared to be dependent on weather conditions. During the summer months, the radiocarbon in plants consisted of 36% soluble metabolites and of 30% unextractable residues (average of 4 experiments); in autumn, the conversion rates were much lower. The following metabolites were identified in both plant species by gas chromatography/mass spectrometry: a polar group (a free trichlorophenol, 2,3,4,6-tetrachlorophenol, pentachlorophenol, conjugates of the latter two compounds, and unidentified water-soluble products) amounting to 35% of the radioactivity in plants cultivated in summer, and a nonpolar group (a dichlorobenzene, 1,2,3-trichlorobenzene, 1,2,4-trichlorobenzene, 1,2,3,5, and/or 1,2,4,5-tetrachlorobenzene, pentachlorobenzene, hexachlorobenzene, and gamma-pentachlorocyclohexene) amounting to 1% of the radioactivity in plants cultivated in summer. The 20 cm top-soil layer had about 14% of the total radioactivity applied to all plants. Six % of the radioactivity recovered from the soil was soluble metabolites and about 50% was not extractable. The soluble metabolites comprised a polar group (free and conjugated 2,3,4,6-tetrachlorophenol, pentachlorophenol, and unidentified water soluble products) amounting to 5% of the radioactivity in the soil as well as a nonpolar group (1,2,3-trichlorobenzene, 1,2,3,4-tetrachlorobenzene, 1,2,3,5 and/or 1,2,4,5-tetrachlorobenzene, pentachlorobenzene, hexachlorobenzene, and gamma-pentachlorocyclohexene) amounting to 1% of the radioactivity in the soil.

Biodegradation, Environmental↗

PubMed1976

Contributions to ecological chemistry CXII1. Balance of conversion of buturon-14C in wheat under outdoor conditions.

The urea herbicide buturon (N-[p-chlorophenyl]-N'-methyl-N'-isobutinyl-urea), 14C-labeled, was sprayed on winter wheat as an aqueous formulation (2.98 kg/ha) under outdoor conditions. Upon harvest (three months after application), a total of 49.2% of the applied radiocarbon was recovered: 2.0% in the plants, 46.9% in the soil, and 0.3% in the leaching water (depth greater than 50 cm); less than 0.1% was in the grains (0.464 ppm). Only about half of the radioactivity present in plants could be recovered under mild extraction conditions; about half of this was unchanged buturon. In straw and husk extracts, the following metabolites were identified by gaschromatography/mass spectrometry:N-(p-chlorophenyl)-N-methyl-O-methyl-carbamate (metabolite I), N-phenyl-N'-formyl-urea (metabolite II), two unstable metabolites giving (p-chlorophenyl)-isocyanate upon purification (metabolites III and IV), N-(p-chlorophenyl)-N'-methyl-N'-isobutenylol-urea (metabolite V), p-chloroformanilide (metabolite VI) and biologically bound p-chloroaniline (metabolite VII). In the root and basal stem extract, the following metabolites were identified by gas chromatography/mass spectrometry: N-(p-chlorophenyl)-O-methyl-carbamate (metabolite VIII) and N-(p-chlorophenyl)-N'-methyl-urea (metabolite IX).

Chromatography, Gas↗

PubMed1976

Contributions to ecological chemistry, CXIV1. Fate of 2,2'-dichlorobiphenyl-14C in rats upon long-term feeding.

Each of five male and five female rats was orally dosed with 49.2 mug 2,2'-dichlorobiphenyl-14C daily for 42 days. After 36 days, the radioactivity in the body reached a plateau level, and male rats had excreted 84.5% of the applied radioactivity, females 87.9%; the residues in most organs were below 0.2 mg/kg. The daily excreted radioactivity after 50 days had decreased to 0.7% (males) and 0.5% (females) of the daily dose; the total excretion was then 86.2% (males) and 89.4% (females) of the total applied dose, and the organs contained less than 0.1 mg/kg. More than 90% of the radioactivity in the excreta was due to metabolites (one monomethoxy-, three monohydroxy-, three dihydroxy-, one trihydroxy-2, 2' -dichlorobiphenyl, conjugates, and a dechlorinated derivative).

Animals↗

PubMed1976

PCBs and environmental contamination.

A survey is given on reported PCB-residues and accumulation in various environmental media including water and aquatic environment, flora, animals, food, and humans. Model studies with technical PCB, as well as with pure individual components, are presented from various working groups. As examples, metabolic studies and photochemical experiments are discussed. According to our present knowledge, a major metabolic pathway in animals and plants is hydroxylation, often followed by methylation or conjugation. By UV-irradiation, however, oxygenation, dechlorination and chlorination, polymerization and isomerization may occur.

Animals↗

PubMed1974