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Biomedical subjects

S Uno

Publications and source records attributed to S Uno.

102 records · Page 6Linked to original sources
PubMed1984

Importance of methionine residues in the enzymatic carboxylation of biotin-containing peptides representing the local biotinyl site of E. coli acetyl-CoA carboxylase.

A biotin-containing hexapeptide Ac-Glu-Ala-Met-Bct-Met-Met (1) that represents the local biotin-containing site of Escherichia coli acetyl-CoA carboxylase has been prepared by the solid phase method. Peptide 1 is carboxylated by the biotin carboxylase subunit dimer of E. coli acetyl-CoA carboxylase with the following kinetic parameters; Km 12 mM, Vmax 2.8 microM X min-1. These compare with the parameters for biotin of Km 214 mM and Vmax 28 microM X min -1. Hence, the overall reactivity (Vmax/Km) of 1 is 1.8 times greater than that of free biotin. When all methionines in 1 are replaced by alanine, the resulting peptide (2) retains a similar binding ability but with a much decreased Vmax. It was also found that peptide 3, which carries an N epsilon-benzyloxycarbonyllysine in place of biocytin in 1, decreases the Km of biotin threefold.

Acetyl-CoA Carboxylase↗
PubMed1983

Sensitive and simplified method for the differential determination of serum levels of ketone bodies.

A highly sensitive and simplified method for the differential determination of serum ketone bodies has been developed. Serum was deproteinized with perchloric acid, and acetoacetate contained in the supernate was reacted with newly synthesized p-nitrobenzene diazonium fluoroborate at 37 degrees C for 10 min. The formed hydrazo compound was converted by alkali to the more stable azo compound which has a peak absorbance at 645 nm. For the determination of 3-hydroxybutyrate, this was enzymatically converted to acetoacetate using 3-hydroxybutyrate dehydrogenase, LDH, NAD and pyruvate. Using 0.2 ml serum, acetoacetate and 3-hydroxybutyrate could be quantitated in 30 min. The described method is five times more sensitive than the enzymatic photometric method and can detect individual ketone bodies at concentrations as low as 20 mumol/l. Differential determination of serum levels of ketone bodies is clinically useful for the diagnosis of type 1 diabetes and in monitoring diabetic control.

3-Hydroxybutyric Acid↗
PubMed1976

2,7-Fluorenediamine and 2,5-fluorenediamine as peroxidase reagents for blood smears.

Our new histochemical methods for peroxidase activity, which do not require benzidine as a hydrogen donor, have been modified for hematological use. Diamine derivatives of fluorene (2,7-fluorenediamine and 2,5-fluorenediamine) were employed in place of benzidine and the result obtained was satisfactory. Two staining techniques were developed. (1) Smears of peripheral blood or bone marrow aspirates were fixed in 2.5 per cent glutaraldehyde solution for 1 minute. Smears were then washed in tap water and covered either by a saturated solution of 2,7-bluorenediamine or by a 0.05 per cent solution of 2,5-fluorenediamine in the presence of hydrogen peroxide for 5 minutes. After being washed in running tap water they were counterstained with Carazzi's hematoxylin solution for 10 minutes. (2) The second technique employs pretreatment of blood smears with 5 per cent CuSO4 solution and aldehyde fixation was omitted. Smears were counterstained by Giemsa stain. The nuclear chromatin structures were well preserved and nucleoli were easily distinguished in the immature cells. In the first method, clear brown granules were recognized in the cytoplasms. In the second method, peroxidase-positive granules were stained black and the staining of nucleus and cytoplasm resembled that of McJunkin's method.

Blood↗
PubMedDate not supplied

Motion perception tested with reversing grating in Duane's syndrome.

Many papers have reported that motion perception asymmetry (MPA) is replaced by motion perception symmetry (MPS) by the 4th to 5th month after birth, when stereopsis starts to occur in normal infants. Duane's syndrome is a congenital motor abnormality, it does, however, reportedly show good stereopsis. We confirmed the stereopsis in Duane's syndrome and checked the motion perception (MP) by using the Reversing Grating Test to investigate if the congenital motor abnormality affects the MP in patients whose binocular sensory system is well developed. Thirty-eight Duane's syndrome patients aged 3 to 45 years were included in the present study. They were divided into 24 cases of Duane I, 9 cases of Duane II, 5 cases of Duane III. The Titmus Stereo Tests, Lang Stereotest, and TV-Random Dot Stereo Test were used to examine the stereopsis. Thirty-four patients had good stereopsis, and 4 had poor stereopsis. None of them showed MPA in any spatial frequencies (1/ 4, 1/2, 1 cycles/degree) examined. The Reversing Grating Test is useful for examining MPA in strabismus patients with eye movement limitations.

Adolescent↗
PubMedDate not supplied

Contamination of organotin compounds and imposex in molluscs from Vancouver, Canada.

Gastropods and bivalves were collected at 15 sites at Vancouver and Victoria, Canada between 24 May and 7 June, 1999, to establish tissue concentrations of butyltin and phenyltin compounds, to record imposex symptoms in gastropods, and to assess the present status of organotin contamination around Vancouver. No neogastropods (such as Nucella lima) were found around Vancouver. Neogastropod populations could have been extirpated by severe TBT contamination in Vancouver, as relatively high concentrations of TBT were detected in tissues of Mytilus trossulus from Vancouver, and the neogastropods distributed in Vancouver might be sensitive to TBT. Recovery from imposex, however, was observed in neogastropod populations from three sites at Victoria and Mission Point. TBT contamination has continued around Vancouver, arising from continuous use of TBT in antifouling paints for vessels larger than 25 m in length; however, TBT has decreased around Victoria and Mission Point. Different patterns of TBT accumulation in tissue were observed among the bivalve species from Vancouver. The highest TBT concentration detected in Tresus capax suggested some possible adverse effects. TBT was the most predominant butyltin component in almost all bivalve specimens surveyed, suggesting a low rate of TBT metabolism. Phenyltin compounds were not detected in any molluscan specimens in this study.

Animals↗
PubMedDate not supplied

Effect of mode of conditioning treatment on efficacy of dentin bonding.

The effect of the mode of application of the Gluma bonding systems' conditioning agents on dentin bonding efficacy was investigated. The reason for this study was the apparent conflict between the manufacturer's instruction to rub the cavity for 30 seconds with a pellet soaked with the conditioning agent and the poor access to some cavity types, which may make it impossible to do so. The efficacy of dentin bonding with or without rubbing conditioning was not different in terms of shear bond strength and marginal cavity adaptation. SEM analysis of the coupling zone showed different resin-impregnated layer thicknesses resulting from the two modes of conditioning. These differences have, however, no impact on the quality of the bond mediated, provided that, as with the Gluma bonding systems, the primer and/or the adhesive resin have perfectly wetted and penetrated the surface collagen and that the degree of polymerization of the resin in the coupling hybrid layer is adequate. The mode of conditioning, therefore, is not critical for dentin bonding with the Gluma systems.

Acid Etching, Dental↗