Anaesthesia in first degree atrioventricular block.

A patient with an intracardiac conduction defect characterised by first degree atrioventricular block due to slowed transmission through the atrioventricular node with increased refractoriness of the node, is described. Asymptomatic first degree block, rarely progressing to transient Wenckebach (type 1 second degree) block had been present for a period of 32 years until general anaesthesia was required, when profound bradycardia attributable to complete atrioventricular block developed abruptly. Subsequent investigations located delayed intracardiac conduction through the atrioventricular node, and indicated excess vagal activity rather than structural disease as the cause.

Glutathione adducts of N-methyl-4-aminoazobenzene formed in vivo and by reaction of N-benzoyloxy-N-methyl-4-aminoazobenzene with glutathione.

N-Benzoyloxy-N-methyl-4-aminoazobenzene (N-BzO-MAB) is believed to be an analogue of the ultimate carcinogenic form of N,N-dimethyl-4-aminoazobenzene (DAB). The reaction of N-BzO-MAB with glutathione in vitro yielded one major and two minor aminoazo dye-glutathione adducts. After purification by ion exchange chromatography and high pressure liquid chromatography, analysis of chemical properties, and the measurement of ultraviolet, visible, proton magnetic resonance, and mass spectra, the major and one minor adduct were identified as 3-(glutathion-S-yl)-N-methyl-4-aminoazobenzene (3-GS-MAB) and 2'-(glutathion-S-yl)-N-methyl-4-aminoazobenzene (2'-GS-MAB) respectively.

The effects of deliberate hypotension and foot down tilt on the incidence of deep vein thrombosis during plastic surgical operations: a pilot survey.

The incidence of postoperative deep vein thrombosis (DVT) has been investigated in a group of 88 patients undergoing plastic surgical operations on the head and neck, and upper limb. Fifty-two cases were operated upon in the foot-down tilt position and 36 were horizontal. With the effects of blood pressure ignored as a possible contributory factor, the incidence of thrombosis in the latter group was 8-3% and was slightly higher in the tilted group (11-5%).

The non-convalent binding of small molecules by ligandin. Interactions with steroids and their conjugates, fatty acids, bromosulphophthalein carcinogens, glutathione and realted compounds.

1. Equilibrium dialysis studies have been made of the binding of a number of small molecules by rat ligandin. Direct measurements of binding together with competition experiments indicated that bromosulphophthalein, oestrone sulphate and dehydroepiandrosterone sulphate each bind at the same single primary binding site with association constants of 1.

The interactions of haem with ligandin and aminoazo-dye-binding protein A.

1. The interactions of ferriprotoporphyrin IX with ligandin and aminoazo-dye-binding protein A result in absorption spectra in the Soret region characteristic of the ligand in its monomeric state. 2.

Spectroscopic studies of the binding of bilirubin by ligandin and aminoazo-dye-binding protein A.

Ligandin and aminoazo-dye-binding protein A both bind bilirubin at a single site. Quantitative studies of the interactions using difference spectrophotometry show that at pH 7.0, protein A binds the tetrapyrrole with an association constant (K) greater than or equal to 2 X 10(7) litre/mol, whereas binding by ligandin is slightly weaker (K = 7 X 10(6) litre/mol) at this pH.

Pharmacological blockade.

Our technique is essentially one of pharmacological blockade achieved for the most part by a combination of ganglion blocking drug, halothane and β-adrenergic blocker. To these are added the effects of posture and controlled respiration to reduce systolic blood pressure to 60-80 mmHg at heart level. Initially this is seldom difficult, but the maintenance of a steady hypotension often needs an increasing amount of halothane together with a rising end-tidal positive pressure.