Carbaryl (1-naphthyl methylcarbamate), labeled with 14C in the C1-naphthyl, carbonyl, or N-methyl position, was introduced into the culture medium of tobacco cells in suspension culture. Following incubation, cells were homogenized in water, centrifugated, and supernatants hydrolyzed with beta-glucosidase or HCl. Organic moieties (moieties) were characterized by two-dimensional thin-layer chromatography (TLC), and many were subsequently identified by infrared and mass spectrometry. On the basis of the data obtained with 14C1-naphthyl-labeled carbaryl, it appeared that 18.4% of the total characterized metabolites represented unconjugated N-CH2OH- carbaryl [1-naphthyl N-(hydroxymethyl)carbamate], excreted by the cells into the culture medium. The metabolites found in the cells primarily consisted of conjugates of 1-naphthol (73.6% of the total characterized metabolites) and N-CH2OH-carbaryl (2.5%). Conjugates of 7-hydroxycarbaryl (7-hydroxy-1-napthyl methylcarbamate), 4-hydroxycarbaryl (4-hydroxy-1-naphthyl methylcarbamate), and 5-hydroxycarbaryl (5-hydroxy-1-naphthyl methylcarbamate) were also detected in small amounts. Of five unknown 14C1-naphthyl-labeled carbaryl metabolites, three were tentatively characterized as: O-1-naphthylcholesterol (Cholest-5-en-3beta-yl-1-napthol: 3.0%); an unconjugated hydroxylated 1,4-dihydro-1,4-epiperoxynapththalene (1.4%); and an acidlabile, beta-glucosidase-resistant conjugate of a cis-dihydrodiol of 1-naphthol (0.3%; other than the trans-5,6-dihydrodiol). The cholesterol derivative may represent a new "detoxification mechanism" in plants; the epiperoxide may help to elucidate plant oxidation mechanisms. A new TLC procedure was developed which successfully separated the acetate derivative of N-hydroxycarbaryl (1-naphthyl N-hydroxy-N-methylcarbamate) from 12 other common moieties of carbaryl metabolites and their acetate derivatives. A new two-dimensional TLC system was developed for the separation of underivatized N-hydroxycarbaryl from 14 other moieties of carbaryl metabolites; two additional two-dimensional TLC systems were utilized for moiety separations. With these TLC procedures, no conjugated or unconjugated N-hydroxycarbaryl could be detected in any tobacco cell culture fraction after incubation of cells in medium containing radiolabeled carbaryl. Authentic 14C1-naphthyl-labeled N-CH2OH-carbaryl was shown to be converted to desmethylcarbaryl (1-naphthylcarbamate) 97%) and 1-naphthol (3%) by 0.1N HCl hydrolysis.

Carbaryl↗

PubMed1976

Nerve blocks of the foot.

Emergency treatment of foot injuries can be made less painful by regional block anesthesia. There is limited medical literature on these techniques and many physicians, while familiar with regional anesthesia of the upper extremity, are not experienced with nerve blocks in the lower extremity. Infiltration anesthesia of the plantar structures of the foot and toes can be very painful and may inhibit healing. Regional anesthesia avoids both of these problems and can prove effective and useful. This paper discusses the techniques and possible complications of nerve block anesthesia of the foot.

Ankle↗

PubMed1975