Search PubMed⌕ Search

Biomedical subjects

W H Anderson

Publications and source records attributed to W H Anderson.

At least 109 records · Page 6Linked to original sources
PubMed1977

Carpal tunnel syndrome: contribution of flexor tendons.

Tension in flexor tendons during wrist flexion may play a role in otherwise unexplained instances of the carpal tunnel syndrome. As the wrist is flexed, the median nerve in the tunnel bends around the taut flexor retinaculum. At the same time, the nerve is subject to compression against this ligament by tensed overlying flexor tendons that also bend around the ligament. Experimental data to support this possibility have been collected from cadaver hands. A pressure transducer has been substituted for the median nerve in the tunnel and registered sizable pressures when tension was applied to the flexor digitorum profundus tendons of the second and third digits during varying degrees of wrist flexion. If the profundus tendons are not tensed, pressure in the tunnel remains negligible until wrist flexion reaches its extreme. Thus, repetitive hand activities involving pinch or grasp during wrist flexion may be a contributing factor in some instances of the carpal tunnel syndrome.

Biomechanical Phenomena↗
PubMed1976

Rifampin, oral contraceptives, and pregnancy.

Rifampin is a drug used in the treatment of tuberculosis. In the literature, there are reports of seven patients who became pregnant while taking a combination of rifampin and oral contraceptives. We report an eighth case involving a woman who became pregnant twice on this drug combination.

Adult↗
PubMed1976

Synthesis of anacardic acids in seeds of Ginkgo biloba.

Anacardic (6-alkylsalicylic) acids and common lipids are efficiently synthesized by immature seeds of Ginkgo biloba. The seeds were incubated with 14C-labeled acetic, malonic and palmitoleic acids, glucose, and other potential precursors. Levels of 14C in common lipids and in anacardic acids, and the distribution of 14C in anacardic acids were determined. The results show that the salicylic moiety is synthesized by a polyketide pathway via malonic acid. The chain moiety for anacardic acid synthesis is in a different state of activation and/or site than chains that are used for synthesis of the common lipids. Labeled shikimic acid did not contribute 14C to anacardic acids, nor to other lipids, and palmitoleic acid was incorporated only into common lipids.

Acetates↗
PubMed1976

Rapid treatment of acute psychosis.

Twenty-four patients with acute functional psychoses were treated with intramuscular haloperidol in a three-hour period. There was almost complete remission of cardinal symptoms (thought disorder, hallucinations, and delusional activity) in this period for 11 patients. Acute dystonia, easily reversed, was the only significant side effect. The authors therefore suggest that outpatient management may be feasible and preferable in the treatment of some acute psychotic episodes.

Acute Disease↗
PubMed1975

Distribution of arachidonic and eicosapentaenoic acids in the lipids of mosses.

Lipid classes from four species of mosses, Mnium cuspidatum, and Mnium medium from Minnesota, and Hylocomium splendens and Pleurozium schreberi from Alaska, were analyzed. The total lipids of all species contained 30-40% arachidonic and eicosapentaenoic acids. However, the lipids from the Alaskan mosses contained about 75% neutral lipids (triacylglycerols, steryl esters and wax esters) whereas the lipids of the other species contained only 20% or less of these neutral lipids. Consistently, monogalactosyldiacylglycerols and phosphatidylethanol-amines were enriched in arachidonic acid and the galactolipids in eicosapentaenoic acid. The distribution of these acids in the phospholipids shows some preference for position 2. Together, the highly unsaturated C20 acids represented 80% of acyl groups in steryl esters. In triacylglycerols they were at average levels, while they were much less in sulfolipids and phosphatidylglycerols. Wax esters contained very little of the highly unsaturated acids but appreciable amounts of phytol and phytenic acid were found as wax constituents.

Arachidonic Acids↗
PubMed1975

Acetylenic acids from mosses.

Two new acetylenic fatty acids, 9, 12-octadecadien-6-ynoic and 11, 14-eicosadien-8-ynoic, were identified from lipids of the moss, Fontinalis antipyretica. They resemble the previously identified 9,12,15-octadecatrien-6-ynoic acid by having a methylene interrupted unsaturated system. The C20 acetylenic acid shows that the capability of mosses to synthesize polyolefinic acids of this chain length applies, in certain species, also to olefinic-acetylenic acids.

Acetylene↗
PubMed1975

Synthesis and analysis of phytyl and phytenoyl wax esters.

An efficient procedure for preparing phytenic acid methyl ester, free of isomers, from phytol is reported. Phytyl phytenate and other isoprenoid wax esters were synthesized. Gas liquid chromatography of these wax esters and other compounds related to phytol and phytenic acid is described. The alkyl constituents of isoprenoid wax esters can be analyzed after alkaline methanolysis and the acyl constituents after acidic methanolysis. The applicability of these methods to natural mixtures was demonstrated with wax esters from mosses which contained both types of isoprenoids and with wax esters from healthy and frost damaged grass which contained phytol, but not phytenic acid.

Chemical Phenomena↗
PubMed1975

The effect of local anesthetic, lidocaine, on guinea pig trachealis muscle in vitro.

The effect of lidocaine was studied in guinea pig trachealis muscle by dose-response reversal and protection of agonist-induced contractures in a superfusion system. Lidocaine reversed histamine, acetylcholine, and depolarizing hypertonic potassium contractures with the median effective doses of 2.8, 6.0, and 3.2 mg. Lidocaine presuperfusion shifted in a nonparallel fashion (P less than 0.05) the dose-response of histamine, acetylcholine, depolarizing potassium, and supramaximal electrical stimulation by contact electrodes. Pretreatment with 7 x 10(-6) M atropine did not modify lidocaine's inhibition of the hypertonic potassium contractions. These findings and the decrease in maximal response indicated noncompetitive antagonism. In contrast to isoproterenol, the action of lidocaine was not influenced by beta-blockade induced by superfusate propranolol, 1.0 mug per ml (P = 0.2). Lidocaine's effect on trachealis smooth muscle was facilitated by a decrease in hydrogen ion activity from pH 6.71 to 7.90, consistent with enhanced penetration of the free base. Low bolus dose lidocaine-induced contractures were noted in many studies. The potency of isoproterenol in comparison to lidocaine, as indexed by median effective doses, was 10(5) greater for reversal of histamine contractures and 10(4) greater for acetylcholine. The data were consistent with a nonspecific, reversible antagonism on the smooth muscle cell and may involve an effect on calcium activity.

Acetylcholine↗