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Y Usui

Publications and source records attributed to Y Usui.

At least 19 recordsLinked to original sources
PubMed1997

Some biochemical properties of the components of Staphylococcus aureus binding to human platelets.

The binding properties of Staphylococcus aureus in relation to human platelets were investigated. Protease digestion (pronase E, proteinase K, trypsin), heat treatment (80 degrees C, 30 min), and sonication for 5 min significantly reduced the binding abilities of the staphylococcal cells to 0% (p < .01), 50 +/- 5% (p < .05), and 38 +/- 9% (p < .05), respectively, while mixed glycosidases did not. Inhibition experiments indicated that protein A and various sugars were ineffective. A binding study using biotinylated cell surface fractions extracted from the whole cells of S. aureus indicated that the proteins having apparent molecular weights of 14400 and 16500 estimated by sodium dodecylsulfate-polyacrylamide gel electrophoresis were involved in the binding between S. aureus and human platelets.

Bacterial Adhesion↗
PubMed1996

Shared amino acid motifs in T-cell receptor beta junctional regions of bronchoalveolar T cells in patients with pulmonary sarcoidosis.

To clarify the nature of the accumulated lung T cells of pulmonary sarcoidosis, we studied bronchoalveolar and peripheral blood (PB) lymphocytes from Japanese patients for expressed T-cell receptor beta-chain variable (TCR V beta) gene usage. Quantitative polymerase chain reaction technique revealed that the V beta repertoires of bronchoalveolar and PB T cells were heterogeneous. However, the bronchoalveolar lymphocytes from five out of 10 patients showed overrepresentation of T cells, with a few TCR V beta families, which varied among individuals, possibly reflecting a difference in the human leukocyte antigen (HLA) backgrounds. Nucleotide sequence analysis of third complementarity determining region (CDR3) segments in overrepresented V beta families demonstrated limited diversity of the transcripts. Two HLA-DR 12(5)+ individuals with overrepresented V beta 6 gene transcripts in the lungs shared a common amino acid motif within their CDR3. By contrast, non-overrepresented TCR V beta transcripts did not show clonal expansion, and the oligoclonal clones in the lung were not found in PB of the corresponding patient. These results showed that, at least in subsets of Japanese patients with pulmonary sarcoidosis, a limited number of T-cell clones are accumulated in the lung in response to a specific antigen. They may mediate an immune response to shape pathology of the disease.

Adult↗
PubMed1995

Analysis of the IgE-epitope of Der f 2, a major mite allergen, by in vitro mutagenesis.

Der f 2 is a major mite allergen composed of 129 amino acid residues. To determine the major epitopes on Der f 2 recognized by human IgE antibodies, artificial mutations were introduced to Der f 2 protein. The IgE-binding activity of Der f 2 was significantly decreased by deletion of 10 amino acids at the N-terminus or nine amino acids at the C-terminus. Site-directed mutagenesis with a single amino acid replacement by Ala or Leu in both N- and C-terminal regions as well as a central portion was performed to generate 42 single-site mutations. Amino acid replacement around a disulfide bond of Cys8-Cys119 caused a marked decrease in IgE-binding activity. Furthermore, a distinct decrease in IgE-binding was also caused by Ala-substitution close to a disulfide bond of Cys73-Cys78 and by mutations of a few charged residues. From these results, it was concluded that the two disulfide-forming regions of Der f 2 and several charged residues are important for forming major epitope structures recognized by human IgE antibodies.

Allergens↗
PubMed1994

Complete obstruction of the inferior vena cava due to chronic relapsing pancreatitis: a case report.

A woman aged 62 with long history of chronic relapsing pancreatitis presented with swelling and ulcer in the lower limbs and occasional gastrointestinal bleeding. The radiological imaging showed complete obstruction of Inferior Vena Cava (IVC) at the level of the pancreas and well developed collateral vessels. Portal vein and splenic vein were also obstructed and superior mesenteric venous blood drained into the liver via coronary vein. She was originally found to have pancreas head tumor, which was not resectable. A palliative operation was performed, but histological examination of pancreatic specimen suggested only chronic inflammation and no evidence of malignancy. She was diagnosed as tumor-forming type chronic pancreatitis. Although SPV or SMV-PV obstruction has been recognized as a complication of chronic pancreatitis, IVC obstruction can occur by the same mechanism. This is the only case but one ever reported. Not only splenoportography but IVC-graphy will contribute to more precise understanding of patient's condition with chronic pancreatitis.

Chronic Disease↗
PubMed1994

Effects of amino acid variations in recombinant Der fII on its human IgE and mouse IgG recognition.

Amino acid sequencing of the major mite allergen Der fII purified from mite body extract revealed that it is a mixture of at least two variants. Substitutions were found only at positions in which amino acid variations were predicted from the nucleotide sequences of three cloned cDNAs. When cDNAs corresponding to the three variants were expressed in Escherichia coli, Der fII proteins were produced as inclusion bodies. Denaturation and renaturation with urea converted recombinant Der fII into a protein with three intramolecular disulfide bonds (Cys8-Cys119, Cys21-Cys27, and Cys73-Cys78), which were identical to those previously identified in native Der fII. All the variants, including native Der fII, were equally recognized by human IgE antibodies from 14 different sera of mite-allergic patients. These results suggested that recombinant Der fII proteins assumed a conformation identical to that of the native Der fII and that all the Der fII variants acted as allergens. This result also suggested that IgE antibody binds to the region where there were no amino acid variations. The binding ability of the monoclonal antibody (mAb) 18G8 for the variant clones 1, 2, and 11 Der fII was almost the same. However, mAb 15E11 bound to clone 1 Der fII more efficiently than to clones 2 and 11, whereas mAb 13A4 recognized clone 2 Der fII as the most preferable antigen. This suggested that these antibodies recognized the region of amino acid variations. The stability of Der fII variants was analyzed by measuring their IgE antibody binding activity after heating, freezing, or acid treatment, and was analyzed by resistance to trypsin digestion.(ABSTRACT TRUNCATED AT 250 WORDS)

Allergens↗
PubMed1994

[Ectopic anus].

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Anal Canal↗
PubMed1994

[Ectopic anus].

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Anal Canal↗
PubMed1994

[Statistic studies on bacteria isolated from urinary tract infections (report 6: isolation rate and drug sensitivity from 1988 through 1989)].

We examined the bacteria isolated from urine of patients in our department from 1988 though 1989. A total of 809 strains were isolated from the outpatients. They were 241 strains of gram-positive bacteria (29.8%). E. coli (32.0%) was isolated most frequently, followed by Enterococcus spp. (9.9%), Proteus group (7.4%), S. epidermidis (6.2%), P. aeruginosa (5.1%) and others. A total of 412 strains were isolated from the inpatients. They consisted of 173 strains of gram-positive bacteria (42.0%). Enterococcus spp. (17.0%) was isolated most frequently, followed by P. aeruginosa (12.6%), S. epidermidis (9.7%), E. coli (7.3%), S. aureus (6.6%) and others. Fewer P. aeruginosa, S. marcescens and Proteus group were isolated from the outpatients and fewer S. marcescens, E. coli and K. pneumoniae from inpatients than previously. More S. aureus were isolated abruptly from the inpatients and more E. coli were isolated from the outpatients than previously. E. cloacae, S. epidermidis, S. aureus and Corynebacterium spp. all isolated from inpatients showed lower antimicrobial sensitivity than those isolated from the outpatients.

Bacteria↗
PubMed1993

Biochemical changes associated with the symptomatic human intervertebral disk.

Significant changes in disk biochemistry were evident in the nuclei pulposi of 25 symptomatic disks that demonstrated abnormal diskography. Compared with the results from ten normal disk from young subjects (mean age, ten years) and from ten asymptomatic disks from adult patients (mean age, 33 years), the symptomatic disks demonstrated significantly greater collagen content than the young and asymptomatic adult subjects, respectively. Significantly fewer total glycosaminoglycans (GAGs) and significantly less water content were also evident for the diseased disks. The mean pH of the nucleus pulposus from 23 patients was also significantly reduced for the symptomatic disks as compared with the mean pH measured for four asymptomatic adult subjects. Although significantly fewer total GAGs were observed for the symptomatic disks, there were no significant differences in the percent composition of hyaluronic acid (HA), chondroitin sulfate (CS), or keratan sulfate (KS) among the normal and symptomatic disks. Significant changes in disk biochemistry are associated with the symptomatic disk, and these changes could contribute to the development of the painful disk syndrome.

Adult↗
PubMed1993

Urinary calcium and renal function in the Japanese female population.

The Japanese have not reached the recommended daily allowance (RDA) for calcium (Ca, 600 mg/day), they are a Ca-deficient population. To determine factors influencing urinary Ca (U-Ca) in the Ca-deficient female population, age, body mass index (BMI), drinking habits, smoking habits and Ca intake were surveyed, and urinary albumin (U-Alb) and retinol binding protein (U-RBP) as renal function tests were analyzed in 210 Japanese females aged 24-76 years. The mean Ca intake for the subjects was 542.8 mg/day, which was less than the RDA for Ca. A significant positive correlation was found between U-RBP and U-Ca, but neither age, BMI, drinking habits, smoking habits, Ca intake nor U-Alb would affect U-Ca in the subjects. In a Ca-deficient status, a proximal tubular dysfunction may be a significant factor increasing Ca loss in urine, and may be a risk factor for osteoporosis.

Adult↗
PubMed1992

Comparative evaluation of the elasticity and flexibility of bioimpregnated knitted grafts.

Longitudinal elasticities of whole human blood clot, whole canine blood clot, Factor XIII cross-linked fibrin, glutaraldehyde-fixed human albumin, and formaldehyde-fixed collagen, gelatin and collagen/gelatin were determined and normalized to human whole blood clot. Matrices of a knitted Dacron graft were then impregnated with albumin, collagen, and collagen/gelatin and their longitudinal elasticities were determined and normalized to a preclotted graft. Comparisons were also made for the longitudinal elasticities of a virgin graft, a manipulated control for a preclotted graft, and a manipulated control for the matrix-impregnated grafts. Flexibilities were then calculated based on the weights and elasticities of these grafts and normalized to the flexibility of the preclotted graft. Fibrin had twice and 39 times more longitudinal elasticity than human blood clot and collagen, respectively. The preclotted graft has longitudinal elastic properties similar to a virgin graft, and is 2.8, 2, and 1.4 times more elastic than the albumin, collagen and collagen/gelatin grafts, respectively. The preclotted graft was 2.5, 2, and 1.4 times more flexible than the albumin, collagen and collagen/gelatin grafts, respectively.

Albumins↗
PubMed1992

Comparative metabolism and requirement of vitamin K in chicks and rats.

The metabolic basis for the high vitamin K requirement of chicks compared with rats was investigated. When chicks and rats were fed the same diet, containing 500 micrograms phylloquinone/kg, the total amounts of phylloquinone and its epoxide metabolite found in the liver and plasma were similar in both species. However, phylloquinone 2,3-epoxide was present in high concentrations in chick liver and serum but not in rat liver and serum. This metabolite of the vitamin is normally reduced by a hepatic vitamin K epoxide reductase. The activity of this enzyme in chicks was approximately 10% of that in rats, and the inability of chicks to effectively recycle the epoxide of vitamin K seems to be the major factor in its high requirement. Other species differences in vitamin K metabolism were observed. Much higher concentrations of bacterial menaquinones were present in rat feces compared with chick feces, but neither species had appreciable hepatic concentrations of menaquinones. Chicks, but not rats, were found to have a liver concentration of menaquinone-4 that exceeded that of phylloquinone. This vitamer was present even when its recognized precursor, menadione, was not present in the diet, and the data indicate that chicks convert phylloquinone to menaquinone-4 under the conditions of these experiments. The mechanism of this conversion was not established.

Alkylation↗