The effects of acid etching on the in-vivo permeability of dentine in the dog.

Cavities were cut in both lower molars of 11 anaesthetized dogs. Dentine permeability was quantitated in these teeth using a filtration technique before and after acid etching to remove the smear layer. Acid-etching increased 5-fold the ease with which fluid could flow across dentine.

A second function of the S gene of bacteriophage lambda.

Infection of Escherichia coli by bacteriophage lambda caused an immediate inhibition of uptake by members of all three classes of E. coli active transport systems and made the inner membrane permeable to sucrose and glycine; however, infection stimulated alpha-methyl glucoside uptake. Phage infection caused a dramatic drop in the ATP pool of the cell, but the membrane did not become permeable to nucleotides.

[Two-dimensional echocardiographic findings during syncopal attack due to obstruction in the outflow tract of the left ventricle in a patient with hypertrophic obstructive cardiomyopathy (author's transl)].

The two-dimensional echocardiogram was successfully obtained during syncopal attack due to obstruction in the outflow tract of the left ventricle in a 52 years old male with hypertrophic obstructive cardiomyopathy (HOCM). The diagnosis of HOCM was confirmed by cardiac catheterization which revealed a pressure gradient of 65 mmHg in the outflow tract of the left ventricle during intravenous infusion of isoproterenol (2 micrograms/min). During the test, the patient developed convulsion as well as syncopal attack.

Alteration in phospholipid composition of Staphylococcus aureus during formation of autoplast.

The phospholipid composition of autoplasts (protoplasts made by autolysis of Staphylococcus aureus 209P was examined. The autoplasts were prepared by incubation of 209P cells in 1.2 M sucrose--0.

Stable state conditions of population-dependent migration models under a zero natural growth rate.

The author "attempts to examine the stable conditions of regional population under a zero natural growth rate in the context of a certain general class of [population-dependent] nonlinear migration models." Theorems regarding the stable state conditions of the migration models are presented. The parameters of the gravity migration model are then estimated empirically using data on Japanese inter-prefectural migration flows in 1966, 1970, and 1975.

Presence and synthesis of cholesterol in stable staphylococcal L-forms.

The sterol which was present in two strains of a stable staphylococcal L-form was analyzed by gas-liquid chromatography and combined gas-liquid chromatography-mass spectrometry. The retention time of the sterol on gas-liquid chromatography was the same as that of authentic cholesterol. Analysis of the sterol by mass spectrometry showed a molecular ion at an m/e of 386 and the same patterns of major ions above an m/e of 145 as those of authentic cholesterol.

Lipid composition of Staphylococcus aureus and its derived L-forms.

Two strains of Staphylococcus aureus (Newman and Tazaki) and their derived L-forms were cultured in serum-containing broth and the differences in their lipid compositions were analyzed. Cardiolipin accounted for more than 50% of the total phospholipid phosphorus in L-forms, but for less than 25% in parent bacteria. The cardiolipin content of L-forms was very high through all growth phases, although it increased gradually as growth proceeded.

Adaptational change in proline and water content of Staphylococcus aureus after alteration of environmental salt concentration.

Adaptation of Staphylococcus aureus to a change in salinity was studied by estimating the intracellular content of water and proline after alteration of the salt concentration of the culture medium. The intracellular water content of S. aureus cultured in normal broth was 1.

A method for microdetermination of major neutral lipids and an application of the procedure to tissue lipids.

Cholesterol, cholesteryl esters, triglycerides and fatty acids as major neutral lipids and phospholipids were examined in quantitative analysis. The method consisted of three steps: (1) separation of lipids by one-dimensional thin-layer chromatography on silica gel plates; (2) elution of neutral lipids from scraped silica gel with chloroform-methanol (4:1); and (3) colorimetric determination of individual neutral lipids in eluates and phospholipids in silica gel. The conditions were modified for chromotropic acid reaction for determining triglycerides.