Biomedical subjects
Publications and source records attributed to K Sugimoto.
The sequence of the 6,408 nucleotides of bacteriophage fd DNA has been determined. This allows to deduce the exact organisation of the filamentous phage genome and provides easy access to DNA segments of known structure and function.
The preceding paper in this journal has reported that pyruvate could be substituted for 2-oxo-glutarate as a substrate of saccharopine dehydrogenase [epsilon-N-(L-glutaryl-2)-L-lysine:NAD oxidoreductase (L-lysine-forming) in the direction of reductive condensation. In the present communication, the kinetic mechanism of saccharopine dehydrogenase reaction with NADH, L-lysine and pyruvate as reactants is reported. The results of initial velocity study, inhibition studies with lysine analogs and a reaction product, NAD+, are consistent with an ordered mechanism with the coenzyme binding first and pyruvate last. The reaction mechanism is at variance with that of the normal reaction in which 2-oxoglutarate is the substrate, in that the order of addition of the amino and oxo acid substrates is reversed. This fact suggests that there exists a small degree of randomness in the binding of amino and oxo acid substrates. From a product inhibition study, NAD+ was shown to be the last reactant released. Saccharopine [epsilon-N-(L-glutaryl-2)-L-lysine] was found to act as a potent dead-end inhibitor of the condensation reactions (of lysine and 2-oxoglutarate, and of lysine and pyruvate) by forming an abortive E. NADH. saccharopine complex.
A coupling sugar preparation (sucrose-free [CSSF]), which contains a mixture of sugars, oligosaccharides, and oligosaccharides terminated at the reducing end by sucrose, served as a substrate for growth and acid production by Streptococcus mutans 6715. However, CSSF was a poor substrate for cellular aggregation, glucosyltransferase activity, plaque formation, and adherence of cells to glass surfaces. In the presence of sucrose, CSSF inhibited glucosyltransfer activity and adherence of cells. The substitution of CSSF for sucrose in a rat diet significantly reduced caries score. Furthermore, rats fed diets containing sucrose and CSSF had significantly fewer carious lesions than did rats fed a sucrose diet.
The occurrences of retinopathy (microaneurysms/small dot hemorrhages) and the coded resting and postexercise ECG findings suggestive of coronary heart disease (CHD) were studied among 420 Japanese male workers exposed to carbon disulfide and 390 men not exposed to such a solvent. Retinopathy was detected in 24.4% of the exposed group and in 3.8% of the nonexposed group by color fundus photography. Among workers of the former group there was a significant correlation between retinopathy prevalences and the index of exposure dosages (r = 0.925, P less than 0.01). However, correlation between the prevalence of retinopathy and duration of exposure was not so high (r = 0.647, 0.10 less than P less than 0.25). The occurrences of coded resting and postexercise "coronary" ECG findings were not related to the index of exposure dosages. Some risk factors for CHD such as total serum cholesterol, triglycerides, beta-lipoproteins, blood pressure, obesity, and skinfold thickness were simultaneously studied. But these variables did not prove to be important in the development of angiopathy due to carbon disulfide, especially the so-called retinopathia sulfocarbonica.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
The promoter for the major coat protein gene of bacteriophage fd contains a unique sequence. TATAAT, in the non-transcribed region corresponding to the Pribnow box. A R-Hha I cleavage site which destroys functions is located five pairs upstream from the TATAAT sequence (fifteen base pairs upstream from the RNA initiation site). The promoter was cleaved into two fragments by R-Hha I and each promoter fragment was joined to DNA fragments derived from other regions. Ligation of the TATAAT-containing fragment to any of the DNA fragments examined resulted in recovery of promoter function. The results suggest for this type of promoter that no unique sequence is necessary upstream from the R-Hha I cleavage site although a contiguous DNA chain must be present in this area.
Immunofluorescent staining of urinary casts of patients with chronic glomerulonephritis or with acute renal failure was performed. Urinary and cast Tamm-Horsfall mucoproteins were purified by a modified McQueen's method. Rabbits were immunized by both of these materials to obtain antisera. The antigenic specificity of the prepared material was examined by Ouchterlony gel diffusion method and immunoelectrophoresis. Indirect and direct immunofluorescent staining methods were done using Tamm-Horsfall mucoprotein antiserum and FITC-GARG, FITC-labelled IgG, IgA, IgM, C3 and albumin. Hyaline casts of both chronic glomerulonephritis and acute renal failure demonstrated fluorescence with Tamm-Horsfall mucoprotein antiserum. The nature of the granular casts of chronic glomerulonephritis seemed to be different from those of acute renal failure because the granules of the former fluoresced for some serum protein fractions, but the latter fluoresced only for Tamm-Horsfall mucoprotein. The absence of fluorescence with epithelial casts for any serum protein fractions implied a different pathogenesis for epithelial casts as compared to granular casts, contrary to Lippman's assumption. A routine technique of immunofluorescent staining of urinary casts was developed. The interpretation of urinary casts should be more specific by this new technique.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.