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Biomedical subjects

A Kawakami

Publications and source records attributed to A Kawakami.

At least 163 records · Page 9Linked to original sources
PubMed1995

Digit and shape memory function in soroban learners: are soroban learners superior in general?

The memory function of 15 soroban learners and 13 novices was examined on visual memory tasks. Analysis showed soroban learners were superior in performance of digit recall but not of shape recall. This result seems to reflect the tendency for soroban groups to be better in processing some kinds of spatial than categorical properties. Based upon these results, effects of soroban learning on brain function were discussed.

Attention↗
PubMed1994

Assignment of disulfide bond location in prothoracicotropic hormone of the silkworm, Bombyx mori: a homodimeric peptide.

The disulfide bond location of a homodimeric peptide, prothoracicotropic hormone (PTTH) of the silkworm, Bombyx mori, was determined by a combination of partial reduction and sequence analysis of peptide fragments generated through a partial reduction of PTTH followed by alkylation and enzyme digestion. The partial reduction and S-alkylation broke the interchain disulfide bond but did not affect the intrachain disulfide bonds, generating monomeric PTTH whose intrachain disulfide bonds were kept intact. This monomeric PTTH has about one-half the biological activity of intact PTTH. Sequence analysis of the fragments generated by lysyl endopeptidase digestion of this monomeric PTTH after complete reduction and S-alkylation by another S-alkylating reagent showed that only the Cys15 residue was reduced and S-alkylated by the foregoing partial reduction, indicating that this residue formed the interchain disulfide bond. The other disulfide bonds which formed intrachain bridgings were determined by sequence and mass analyses of the fragments generated by two successive enzyme digestions of the monomeric PTTH. In conclusion, the disulfide bond location of PTTH was assigned to Cys15-Cys15' as an interchain disulfide linkage and Cys17-Cys54, Cys40-Cys96, and Cys48-Cys98 as intrachain disulfide linkages.

Amino Acid Sequence↗
PubMed1994

Intron-exon organization and chromosomal localization of the human TIA-1 gene.

TIA-1 is a 40-kDa cytotoxic granule-associated RNA-binding protein (p40-TIA-1), the expression of which is restricted to cytolytic lymphocytes. The major granule-associated species is a 15-kDa protein (p15-TIA-1) that seems to be derived from the carboxyl terminus of p40-TIA-1. Although some evidence suggests that p15-TIA-1 is derived from p40-TIA-1 by proteolytic processing, it is also possible that each isoform is derived from discrete mRNA initiated from alternative promoters within the TIA-1 gene. To learn more about the relationship between p15-TIA-1 and p40-TIA-1, we have determined the complete intron-exon organization of the TIA-1 gene. The gene consists of 13 exons separated by 12 intervening sequences and spans greater than 46 kb of DNA located on chromosome 2, band p13. The transcription start site of the mRNA transcript encoding p40-TIA-1 was identified by primer extension and S1 mapping analysis. The putative promoter region preceding this transcription start site stimulated the expression of a reporter gene in transfected Jurkat and YT cells. Attempts to identify a second promoter capable of initiating an mRNA encoding p15-TIA-1 were unsuccessful, supporting the possibility that p15-TIA-1 can be derived from p40-TIA-1 proteolytically. Granule-associated serine proteases that have been implicated in cytolytic lymphocyte killing (granzyme A and granzyme B) were unable to cleave TIA-1, suggesting that processing may occur before TIA-1 enters the cytotoxic granule.

Amino Acid Sequence↗
PubMed1994

Cohort effects in the lateral preference of Japanese people.

Handedness data of the Japanese were collected twice with an interval of 20 years, using an identical handedness inventory. In the second cohort, non-right-handers among male and female students numbered 11.5% and 5.9%, respectively. The results showed that the incidence of non-right-handedness among Japanese females has increased from 20 years ago.

Adult↗
PubMed1994

[A case of post-rubella Guillain-Barré syndrome associated with ulcerative colitis].

A 56-year-old female with post-rubella Guillain-Barré syndrome (GBS) associated with ulcerative colitis (UC) was described. The patient dramatically recovered with plasmapheresis. It is very rare to encounter the neurological complication following rubella, especially polyradiculoneuropathy as observed in the present case. Significantly high titer of anti rubella antibody at admission and subsequent decrease in the titer suggest that rubella infection is likely to involve the development of GBS. Although GBS and UC are currently regarded as autoimmune disorders, association of GBS and UC is extremely rare and only a few cases have been reported. All of them including the present case developed GBS while UC was in remission. Similarly to previous reports of GBS or UC, our case also had an HLA type of B35 and DR2. Thus the present data suggest that infectious agents as well as individual susceptibilities are important for the development of GBS.

Colitis, Ulcerative↗
PubMed1993

Stimulation of mitogenesis in human thyroid epithelial cells by endothelin.

We investigated whether a potent vasoconstrictor, endothelin, stimulated the proliferation of human thyroid epithelial cells (thyrocytes). [3H]-thymidine incorporation into normal thyrocytes and thyrocytes from patients with Graves' disease was significantly increased at 10(-9) mol/l endothelin, reaching a plateau at 10(-8) mol/l. The proliferative responses of the thyrocytes obtained from patients with Graves' disease were similar to those of normal thyrocytes. Furthermore, the cell number of thyrocytes stimulated by endothelin was increased as compared with that of unstimulated thyrocytes. Neither indomethacin nor heparin affected this endothelin-stimulated thyrocyte proliferation. When thyrocytes were cultured with both endothelin and recombinant interleukin 1 beta, there was an additive effect on thyrocyte proliferation. The Ca2+ entry blocker, verapamil, inhibited both the proliferative responses of thyrocytes to endothelin and the additive effect of endothelin and recombinant interleukin 1 beta on thyrocyte proliferation. These results suggest that endothelin functions as a growth-promoting factor for human thyrocytes, presumably through intracellular calcium influx.

Calcium↗
PubMed1993

[Blood purification after aorto-coronary bypass grafting for dialysis patients].

Four dialysis patients received aorto-coronary bypass grafting (CABG) at Fukuyama cardiovascular hospital from April 1989 to March 1992. We employed continuous ambulatory peritoneal dialysis (CAPD) in two cases, hemodialysis with extracorporeal ultrafiltration method (ECUM + HD) in one case and hemodiafiltration with continuous veno-venous hemofiltration (CVVHF + HDF) in one case for perioperative management. In each cases, intermittent HD was undergone during 4 days before operation. Intraoperatively, HD was used together with extracorporeal circulation. Blood pressure in the postoperative course changed more frequently in CAPD cases than ECUM + HD or CVVHF + HDF case. Especially, CVVHF + HDF stabilized the movement of circulation and kept balance of serum BUN, Cr after the operation (BUN; 27.2 +/- 6.3, Cr; 5.0 +/- 0.6). We concluded that CVVHF + HDF would be the most favorable method to maintain the fluid balance stably for the uremic patients after CABG.

Adult↗
PubMed1992

Identification and functional characterization of a TIA-1-related nucleolysin.

We recently reported the molecular cloning of a cytotoxic granule-associated RNA-binding protein designated TIA-1. The ability of recombinant TIA-1 to induce DNA fragmentation in permeabilized cells suggested that this protein is the granule component responsible for inducing apoptosis in cytolytic lymphocyte (CTL) targets. Here we report the characterization of a cDNA encoding a TIA-1-related protein designated TIAR. The deduced amino acid sequence of TIAR reveals it to be a 42-kDa protein possessing three RNA-binding domains and a carboxyl-terminal auxiliary domain. Although the RNA-binding domains of TIA-1 and TIAR share greater than 85% amino acid homology, their carboxyl-terminal auxiliary domains are only 51% homologous. The carboxyl terminus of TIAR contains a lysosome-targeting motif, indicating that TIAR is probably a cytotoxic granule-associated protein. Like TIA-1, purified recombinant TIAR induced DNA fragmentation in permeabilized target cells. Although immunoblotting analysis of post-nuclear supernatants revealed TIA-1 protein to be restricted to CTLs, PCR analysis revealed the expression of TIA-1 and TIAR mRNA transcripts in a wide variety of cell types. Our data suggest that the granules of CTLs contain at least two candidate nucleolysins involved in CTL killing.

Amino Acid Sequence↗
PubMed1992

Increased adherence of T cells to human endothelial cells in patients with human T-cell lymphotropic virus type I-associated myelopathy.

We investigated the adherence of T cells to human umbilical vein endothelial cells in seven patients with human T-lymphotropic virus type I (HTLV-I)-associated myelopathy. The adherence of T cells to endothelial cells increased significantly in all the patients with HTLV-I-associated myelopathy when compared with the adherence in the seronegative controls (1.3- to 2.8-fold) and compared with the adherence in the anti-HTLV-I-seropositive non-HTLV-I-associated myelopathy carriers (1.4- to 2.8-fold). Prior treatment of the endothelial cell monolayer with recombinant interferon gamma (50 IU/mL) enhanced the T cell-endothelial cell adhesion in both the controls and patients with HTLV-I-associated myelopathy. However, values after prior treatment in the patients with HTLV-I-associated myelopathy were significantly higher than those in seronegative controls and carriers. The results suggest that the significantly increased T cell-endothelial cell adherence may be related to the initial stages of lymphocyte migration from the blood to the central nervous system in patients with HTLV-I-associated myelopathy.

Aged↗
PubMed1992

Magnetic resonance imaging detection of aortic and pulmonary artery wall thickening in the acute stage of Takayasu arteritis. Improvement of clinical and radiologic findings after steroid therapy.

OBJECTIVE: Early diagnosis of Takayasu arteritis in the acute stage (prepulseless stage) is extremely difficult. Identification of a useful approach to detecting the initial changes of arteritis is therefore desirable. METHODS: Careful clinical examination of a young woman with persistent fever and dry cough revealed faintly audible bruits at the cervical, supraclavicular, and abdominal regions. Aortographic features suggested thickening of the wall of the descending thoracic aorta. Magnetic resonance imaging (MRI) of this area was diagnostic. RESULTS: MRI demonstrated involvement of the ascending aorta and right main pulmonary artery. Steroid therapy (prednisolone 60 mg/day) induced dramatic clinical and radiologic improvement in 2 months. CONCLUSION: This is the first report of MRI-documented reduction in the thickness of the walls of both the aorta and the pulmonary artery following steroid therapy.

Acute Disease↗
PubMed1992

Structure and expression of bombyxin-related peptide genes of the moth Samia cynthia ricini.

From the genomic DNA of the moth Samia cynthia ricini, we cloned and characterized six clustered genes that encode precursor molecules for peptides structurally related to bombyxin, a Bombyx mori brain secretory peptide that is structurally like insulin and functionally like the prothoracicotropic hormone. The precursor molecules deduced from these genes have the domain organization of signal peptide/B-chain/C-peptide/A-chain, as in preprobombyxins and preproinsulins. The Samia bombyxin-related peptide (SBRP) genes are classified into families A and B according to their sequence homology. Two genes belonging to different families are arranged close to each other to form a pair with opposite transcriptional orientations (A-1/B-1, A-2/B-2, and A-3/B-3). None of these genes have introns, and gene B-3 has an in-frame stop codon representing a pseudogene. Four genes, A-1, A-3, B-1, and B-2, are expressed in Samia brain. Genomic Southern hybridization suggests that the Samia genome contains many other SBRP genes.

Amino Acid Sequence↗
PubMed1992

Interferon-alpha and dexamethasone inhibit adhesion of T cells to endothelial cells and synovial cells.

We investigated whether interferon-gamma (IFN-gamma), interferon-alpha (IFN-alpha) and glucocorticoids affected the adhesion of T cells to human umbilical endothelial cells or human synovial cells. About 30% of peripheral blood T cells could bind to unstimulated endothelial cells, but only a few T cells could bind to unstimulated synovial cells. When both endothelial cells and synovial cells were cultured with recombinant IFN-gamma (rIFN-gamma), the percentage of T cell binding to both types of cells increased in a dose-dependent manner. rIFN-alpha and dexamethasone blocked the T cell binding to unstimulated endothelial cells. Furthermore, rIFN-alpha and dexamethasone suppressed T cell binding to both endothelial cells and synovial cells stimulated by IFN-gamma, and also inhibited intercellular adhesion molecule-1 (ICAM-1) expression on both endothelial cells and synovial cells stimulated by IFN-gamma. These results suggest that IFN-alpha and glucocorticoids may inhibit T cell binding to endothelial cells or synovial cells by modulating adhesion molecule expression on these cells.

Arthritis, Rheumatoid↗
PubMed1992

HTLV-I associated arthritis: characteristics of an HTLV-I virus infected T cell line from synovial fluid.

A T cell line from mononuclear cells in the synovial fluid of a patient with polyarthritis was established. The T cell line reacted with serum samples positive for antibodies to human T cell lymphotropic virus type I (HTLV-I) and with monoclonal antibody to HTLV-I p19. In Southern blotting with an env-pX-LTR HTLV-I probe and digestion of T cell line DNA with the restriction enzymes ClaI, DraI, and PstI generated fragments that were identical to those found in two HTLV-I infected T cell lines established from adult T cell leukaemia or HTLV-I associated myelopathy. The T cell line expressed CD2, CD3, CD4, CD45RA, CD29, HLA-DR, CD25, and CD26 antigens, but not CD8 and CD20 antigens. Large amounts of interleukin 6, interferon gamma, and tumour necrosis factor alpha were secreted in the culture supernatants of this cell line. This line helped immunoglobulin production by B cells, but not K562, Raji, and synovial cell lysis.

Aged↗
PubMed1992

Primary Sjögren's syndrome with antibodies to HTLV-I: clinical and laboratory features.

The prevalence of antibodies to human T lymphotropic virus type I (HTLV-I) was studied in patients with primary Sjögren's syndrome. Thirteen of 36 serum samples were positive by enzyme linked immunosorbent assay (ELISA) and particle agglutination assay for antibodies to HTLV-I and were confirmed by western blotting. The presence of antibodies to HTLV-I may signify an HTLV-I carrier state. These patients had a high occurrence of extraglandular manifestations such as uveitis, myopathy, and recurrent high fever compared with patients who did not have antibodies to HTLV-I. Patients with antibodies to HTLV-I had an increased spontaneous proliferation of peripheral blood mononuclear cells compared with those without the antibodies. The proportions of activated and memory T cells (HLA-DR+ CD3+, CD25+ CD3+, and CD29+ CD4+ cells) were higher in HTLV-I carriers than in non-carriers. The presence of antibodies to HTLV-I in some patients with primary Sjögren's syndrome suggests that HTLV-I may cause primary Sjögren's syndrome or its extraglandular manifestations, or both.

Adult↗
PubMed1992

Oxidative damage to the membrane of canine erythrocytes with inherited high Na, K-ATPase activity.

Oxidative damage to the membrane in canine erythrocytes with inherited high Na, K-ATPase activity (HK cells) was compared with that in normal canine cells (LK cells). When 30 mM beta-acetylphenylhydrazine (APH) was applied to HK and LK cells, lipid peroxidation and hemoglobin denaturation occurred. Lipid peroxidation determined from malondialdehyde (MDA) formation was significantly lower in HK than in LK cells so far as endogenous glutathione (GSH) concentration was maintained at appropriate levels. With the depletion of GSH, MDA formation was accelerated and difference between HK and LK cells was not significant. Denatured hemoglobin bound to the membrane protein was less in HK than in LK cells. During incubation with APH, osmotic fragility increased markedly in LK cells, while HK cells showed very little change. The amounts of total lipid, total and free cholesterol, glycolipid, phospholipid and fatty acids were essentially the same in both cell types. Fatty acid compositions showed very small differences. The membrane of HK cells thus appear to have greater protection against oxidative damage induced by APH, owing to the presence of excess GSH in HK cells. The capability of HK cells to withstand oxidative damage would not be due to differences in membrane lipid compositions.

Animals↗
PubMed1992

WF11605, an antagonist of leukotriene B4 produced by a fungus. I. Producing strain, fermentation, isolation and biological activity.

WF11605, a new antagonist of leukotriene B4 (LTB4) was isolated as a product of fungal strain F11605. The molecular formula of WF11605 was determined to be C38H60O11. WF11605 inhibited LTB4-induced chemotaxis of rabbit polymorphonuclear leukocytes (PMNLs) with an IC50 value of 1.7 x 10(-7) M and blocked 3H-LTB4 binding to PMNL membranes at 5.6 x 10(-6) M (IC50). WF11605 also inhibited LTB4-induced degranulation of rabbit PMNLs at 3.0 x 10(-6) M (IC50). However, WF11605 did not show any inhibitory effect on platelet activating factor (PAF)- and N-formyl-L-methionyl-L-leucyl-L-phenylalanine (FMLP)-induced degranulation at concentrations up to 10(-4) M. These results suggest that WF11605 is a specific antagonist of LTB4.

Animals↗