Labetalol in controlled hypotension: administration of labetalol when adequate hypotension is difficult to achieve.

A study of controlled hypotension was undertaken in 50 major surgical patients using labetalol, a drug with both alpha- and beta-adrenoceptor blocking activity. The patients were such that difficulty in achieving controlled hypotension could be anticipated: the young, the anxious and those for whom halothane was contraindicated. The administration of labetalol quickly induced hypotension which was controlled easily and was rapidly antagonized.

Use of labetalol during halothane anaesthesia.

The drugs that are available to attain controlled hypotension during anaesthesia are not entirely satisfactory. Problems in controlling hypotension are encountered in the young, the anxious, patients with a tachycardia, and in those for whom halothane is contra-indicated. Labetalol has been investigated as an adjunct to controlled hypotension in 150 major surgical procedures.

The effects of enzymatic digestion on the elastic properties of isolated human cerebral arteries.

Measurement of volume, pressure, and length were made on eight segments of human cerebral arteries perfused with chymotrypsin (CT) (EC 3.4.21.

Effects of high static pressures on human cerebral arteries in vitro.

Static elastic properties were obtained from pressure, volume, and length measurements of 34 isolated human cerebral arteries from 23 circles of Willis of patients aged 23-76 years. No significant difference in initial or final elastance was observed with age or branch in the circle of Willis. Twenty-four of the arteries from 18 circles of Willis were then subjected to transmural pressures of 200-300 mm Hg for periods of less than or equal to 5 minutes and the elastic properties restudied.

A scanning electron microscope study of human cerebral arteries.

Human cerebral arteries were obtained from autopsy, fixed under pressure, cut open, and tacked onto pieces of cork. For one artery the intima was partly teased away, exposing the media, and treated with a silver nitrate process. For another artery the adventitia was exposed.

Identification and distribution of epoxyacyl groups in new, natural epoxy oils.

New high-epoxy vegetable oils from nine species representing three plant families and four genera have been investigated. The epoxyacyl moiety in at least one oil from each genus was characterized and shown to be the (+)-vernoloyl (cis-12,13-epoxy-cis-9-octadecenoyl) group. Intraglyceride distribution studies revealed a general preference of the (+)-vernoloyl groups for the beta-position of triglyceride molecules.

Gas--liquid chromatography of silylated mixtures from lipolysis of triglycerides containing unusual fatty acyl groups.

A convenient and rapid procedure involving methylation, silylation, and temperature-programmed gas-liquid chromatography (GLC) is described for analyzing unfractionated products from the hydrolysis of triglycerides with pancreatic lipase. The conditions employed for GLC were selected to provide maximum and rapid separation of silylated monoglycerides in which the acyl moieties differ in chain length or degree of substitution with oxygen-containing functional groups. Derivatives differing only in the number of double bonds present were not separated.