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Biomedical subjects

K G Brown

Publications and source records attributed to K G Brown.

At least 37 records · Page 2Linked to original sources

Phase transitions in combined rabbit muscle sarcoplasmic reticulum lipids by Raman spectroscopy.

Using Raman spectroscopy, we found that the sarcoplasmic reticulum lipids of combined muscles from rabbit leg undergo at least two reversible temperature phase changes, centered at about -15 and 13 degrees C. Below the first transition, the lipid Raman CH st region is characteristic of the hexagonal lamellar gel phase. Above the second transition, the Raman CH stretch region is that of a "melted" lamellar phase, somewhat more rigid than a monophasic lipid system. The composition of the lipids was determined and the possibility of a relation between the major head group types and the phase transitions is discussed. Since SR Ca2+ATPase activity is enhanced at about 14-19 degrees C, the Raman studies suggest that ATPase activity is enhanced when the 13 degrees C transition is complete.

Animals↗

The nephrotic syndrome in Malawian blacks.

This study deals with the nephrotic syndrome in 34 Malawian Blacks, Plasmodium malariae infection and the use of mercury-containing skin lightening creams (Butone 3) must be included among the usual causes of nephrotic syndrome in the Malawian Black.

Adolescent↗

Cardiac disease in Malawi.

A prospective clinical study of 114 Malawian patients with cardiac disease seen at Queen Elizabeth Central Hospital, Blantyre, is presented. Rheumatic and hypertensive heart disease, cardiorenal failure and severe anaemia were the most common causes. Pericardial disease, mainly due to tuberculosis, was an important treatable cause of cardiac disease. Endomyocardial fibrosis was not diagnosed with certainty and cardiomyopathy was relatively uncommon. Ischaemic heart disease was not seen.

Adolescent↗

Vessel dimensions in premature altheromatous disease of aortic bifurcation.

The area ratio of the abdominal aortic bifurcation is defined as the ratio of the sum of the cross-sectional areas of the common iliac arteries to the cross-sectional area of the aorta. Abnormality of the area ratio is associated with initiation of atheroma of the lower aorta. Hypoplasia of the abdominal aorta predisposes to early occlusion as the atheromatous process advances.In five out of six women with thrombosis at the aortic bifurcation the area ratio was low. Hypoplasia of the abdominal aorta was present in two of these patients. All six patients were successfully treated by aortoiliac disobliteration and reconstruction.

Adult↗

Conformationally dependent low-frequency motions of proteins by laser Raman spectroscopy.

Low-frequency Raman bands (lower than 50 cm(-1)) exist in certain proteins. They are dependent upon the conformation of the protein molecule, but are relatively independent of the form of the sample, i.e., whether it is a film or a crystal.Low-frequency Raman spectra were obtained from samples of alpha-chymotrypsin that had been prepared in several ways. A peak at about 29 cm(-1) was found for all samples except the one that had been denatured with sodium dodecyl sulfate. Such low frequency motions must arise from vibrations that involve all, or very large portions, of the protein molecule.

Acylation↗

Bactericidal action of nalidixic acid on Bacillus subtilis.

Cook, Thomas M. (Sterling-Winthrop Research Institute, Rensselaer, N.Y.), Karen G. Brown, James V. Boyle, and William A. Goss. Bactericidal action of nalidixic acid on Bacillus subtilis. J. Bacteriol. 92:1510-1514. 1966.-Nalidixic acid at moderate concentrations exerts a bactericidal action upon the gram-positive bacterium Bacillus subtilis. The synthesis of deoxyribonucleic acid (DNA) in B. subtilis is selectively inhibited by nalidixic acid at concentrations approximating the minimal growth inhibitory concentration. Higher concentrations (25 mug/ml) result in a 30 to 35% degradation of DNA. After extended exposure to nalidixic acid, protein synthesis is also depressed. Cells of B. subtilis treated with nalidixic acid exhibit characteristic morphological abnormalities including cell elongation and development of gram-negative areas. From the results presented, it can be concluded that the mode of action of nalidixic acid upon susceptible bacteria is similar for both gram-positive and gram-negative species.

Anti-Bacterial Agents↗