Nerve conduction studies in upper extremities: skin temperature corrections.

The relationship of skin to near nerve (NN) temperature and to nerve conduction velocity (NCV) and distal latency (DL) was studied in 34 normal adult subjects before and after cooling both upper extremities. Median and ulnar motor and sensory NCV, DL, and NN temperature were determined at ambient temperature (mean X skin temp = 33 C) and after cooling, at approximately 26, 28, and 30 C of forearm skin temperature. Skin temperatures on the volar side of the forearm, wrist, palm, and fingers and NN temperature at the forearm, midpalm, and thenar or hypothenar eminence were compared with respective NCV and DL.

Diabetic neuropathy: a clinical, laboratory and electrodiagnostic study.

The objective of this study was to determine the relationship between nerve conduction velocity (NCV) and hyperglycemia and to assess the extent of NCV changes in adult-onset diabetic patients before and after diabetic treatment. Twenty-five diabetic males (mean age = 50.9 years) were tested twice prior to beginning diabetic treatment.

Preparation of semisynthetic (+)-tubocurarine chloride.

Semisynthetic (+)-tubocurarine chloride (II) was prepared by monoquaternization of (+)-tubocurine. The method involved treating (+)-tubocurine with a 0.5 M equivalent of hydrochloric acid prior to quaternization with methyl iodide, followed by neutralization and iodide-chloride ion-exchange.

Stereochemical preferences for curarimimetic neuromuscular junction blockade IV: Monoquaternary ammonium probes possessing carbon and nitrogen asymmetry.

Two enantiomeric pairs of neuromuscular junction blocking agents were prepared in which an asymmetric carbon atom is adjacent to an asymmetric quaternized nitrogen moiety. The blocking agents were obtained from the enantiomers of laudanosine by stereoselective quaternization with benzyl and ethyl iodides. Curarimimetic potencies were measured with an in vivo cat hypoglossal nerve-tongue muscle preparation.

Dequaternization of curare bases with sodium thiophenoxide and ethanolamine.

To prepare (+)-tubocurine and O,O-dimethyl-(+)-tubocurine, the commonly used dequaternization procedures with sodium theophenoxide and ethanolamine were investigated. The quaternary compounds were (+)-tubocurarine chloride and the chloride and iodide salts of O,O-dimethyl-(+)-chondocurarine. The results obtained with ethanolamine indicate that Hofmann elimination is a major pathway and that N-demethylation is minor.

Hofmann elimination with diazomethane on curare bases and selected quaternary tetrahydroisoquinoline alkaloids.

Use of a large excess of alkali-free diazomethane resulted in a Hofmann elimination with selected curare bases and some other quaternary tetrahydroisoquinoline alkaloids. (+)-Tubocurarine chloride provided a monostilbene methine, O,O-dimethyltubocurinemethine, and a monostilbene--monostyrene compound, O,O-dimethyltubocurinedimethine. The major elimination products of (+)-isotubocurarine chloride and (+)-carnegine methiodide were monostyrene methines, O,O-dimethyltubocurineisomethine and carneginemethine, respectively.

Coumarins XIV: high-resolution mass spectra of 3',4'-disubstituted 3',4'-dihydroseselins.

High-resolution mass spectra of 14 3',4'-disubstituted 3',4'-dihydroseselins were examined. The nature of the substituents determinines the mode of fragmentation. Compounds having one or two acyloxy substituents fragment mainly by a pathway leading to the stable coumarinopyrilium ion.

Synthesis and blood pressure lowering activity of benzylic ethers of 2-diethylaminoethanol and a related diamine.

Based upon the unpublished finding that 3'-hydroxy-4'-(beta-diethylaminoethoxy)-3',4'-dihydroseselin possessed a potent blood pressure lowering effect in the cat at a dose of 1 mg/kg, the present study examined the activities of several related compounds. These compounds were derived by dissection of the parent compound to give four benzylic ethers of 2-diethylaminoethanol and a diamine, derived by replacing the ether oxygen of the parent compound with an N--CH3 function. The simplest compounds were the benzyl and 2,6-dimethoxybenzyl ethers of the aminoalcohol.

Sterochemical preferences for curarimimetic neuromuscular junction blockade III: enantiomeric bisquaternary amines related to benzoquinonium as probes.

Enantiomeric neuromuscular junction blocking agents, which are of the benzoquinonium type but which have a methyl group introduced adjacent to the quaternary moieties to provide an asymmetric center were synthesized and tested to determine whether the neuromuscular junction exhibits the relatively modest (R) greater than (S) superiority shown toward previously tested bisquaternaries. Testing included a mouse inclined screen assay and an in vivo cat hypoglossal nerve-tongue preparation, as well as standard estimations of anticholinesterase activity since the candidate compounds are known to have such a component in their activity spectrum. The observed 2:1 difference in blocking activity favoring the compound with an (R)-configuration is the same as that for previously tested bisquaternaries, both in direction and magnitude.

Stereochemical preferences for curarimimetic neuromuscular junction blockade II. enantiomeric bisquaternary amines as probes.

Two pairs of bisquaternary enantiomeric neuromuscular junction blocking agents as well as their diasteriomeric mesoforms were prepared in which the carbon asymmetry is adjacent to the quaternary center. The tertiary amines from which the blocking species were obtained by methyl iodide treatment were N-methylpavine and 1,1'-dodecamethylenebis(6,7-dimethoxy-2-methyl-1,2,3,4-tetrahydroisoquinoline). Blocking potencies were determined by the mouse inclined screen assay and by the cat tongue-hypoglossal nerve technique.

Stereochemical preferences for curarimimetic neuromuscular junction blockade I: enantiomeric monoquaternary amines as probes.

Seven pairs of monoquaternary enantiomeric neuromuscular junction blocking agents were prepared in which the carbon asymmetry is adjacent to the quaternized nitrogen moiety. The tertiary amines from which the blocking species were obtained are carnegine, laudanosine, N-methylpavine, corydine, isocorydine, glaucine, and boldine. Curarimimetic potencies, obtained with an in vivo cat tongue-hypoglossal nerve preparation, were obtained for the enantiomeric methiodides of each of these amines.