Genetic analysis of Escherichia coli mutants defective in adenylate kinase and sn-glycerol 3-phosphate acyltransferase

Complementation analysis with independently isolated plA and adk (adenylate kinase) mutants of Escherichia coli showed that all the mutants belong to the same complementation group. The results suggest that the adk (plsA) locus is the structural gene for adenylate kinase.

Membranous lipodystrophy: a clinicopathological study of six cases

Membranous lipodystrophy apparently is a new disease, first reported and named by Nasu and associates 31 in 1971. We have collected six cases of this disease. The initial manifestation was articular pain at adolescence. Symmetrical changes in the bones of the extremities then appeared and the disease seemed to progress slowly with age. The younger patients exhibited only skeletal pain or fractures, while the older patients had some neuropsychiatric changes. Three of the patients died in middle age. The cystic bone lesions contained a yellow, lipid-like substance which histologically showed a characteristic membranocystic appearance. Electron microscopic study showed unique features, but biochemical analysis of the substance did not reveal a definable abnormality.

Moonquakes: Mechanisms and Relation to Tidal Stresses

Observed features of moonquakes are combined with theoretical calculations of the tidal stresses to interpret the moonquake mechanisms. Tidal stresses, together with a postulated ambient tectonic stress, are sufficient to explain the depth, periodicity, and polarity reversal of moonquakes. Both of these stresses are small (on the order of 1 bar) and consistent with the small magnitudes of moonquakes.

Leukocyte transketolase activity as an indicator of thiamin nutriture in rats

The purpose of this study was to evaluate the possibility of using leukocyte transketolase activity (TKA) as an index of thiamin status. It was shown previously that hepatic TKA in rats is altered by changes in the type and amounts of carbohydrate, protein, and fat in the diet. It was, therefore, essential to determine whether leukocyte TKA in rats is affected by dietary factors other than thiamin intake. Hepatic TKA and leukocyte TKA both varied with dietary thiamin intake; maximum activity was attained when the diet contained 3 to 4 mg thiamin/kg diet. Administration of oxythiamin resulted in decreases in TKA in both liver and leukocytes. The changes in leukocyte and hepatic TKA induced by varying degrees of thiamin deficiency were closely correlated. The responses of thiamin content were also closely correlated in liver and leukocytes. However, only hepatic TKA was altered by increasing the fat or protein content of the diet or by substituting fructose for glucose. None of the dietary manipulations studied except the production of thiamin deficiency had any effect on leukocyte TKA. We conclude from our results that leukocyte TKA is a sensitive and specific indicator of thiamin nutriture in rats.