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Biomedical subjects

M Kasuga

Publications and source records attributed to M Kasuga.

At least 163 records · Page 9Linked to original sources
PubMed1997

[The effect on bowel sounds of very hot compresses applied to the lumbar region].

In Japan, very hot moist compresses applied to the lumbar region have been used to promote intestinal movement and flatus or defecation. This skill was based on empirical knowledge. One of the purposes of this study is to make clear the effect of very hot compresses on intestinal movement. The other purpose is to prove the safety of the skin where very hot compresses applied. The sample consisted of 8 healthy female volunteers, ranging in age from 27 to 47 with a mean age of 37.4. A very hot compress was applied to the lumbar region for 10 minutes. The results were as follows: 1) Bowel sounds immediately after hot compresses increased 1.7 times compared with bowel sounds before the hot compresses. 2) Skin temperature of the back increased to 41.1-43.1 degrees centigrade under the hot compresses, then decreased rapidly. 3) Blood flow to the back during hot compresses, increased to 156%. Blood flow to the upper arm also increased. 4) Body temperature, pulse rate and blood pressure were not remarkably changed by the hot compresses. The results of the experiments show that very hot compresses applied to the lumbar region affect intestinal movement. And the results suggest that a very hot compress is a useful nursing skill to promote flatus or defecation.

Adult↗
PubMed1997

[A case of MPO-ANCA positive progressive systemic sclerosis with status epileptics].

A 37-year-old female, who had been suffering from progressive systemic sclerosis (PSS) with long-term renal failure, was diagnosed as MPO-ANCA positive PSS in active stage. She had systemic scleroderma, normotensive renal failure and pulmonary fibrosis. Respiratory management and steroid therapy under the control of CVVH were done for her treatment. She developed hemolytic anemia and thrombocytopenia during the treatment. She was diagnosed as microangiopathic hemolytic anemia, and was treated with plasma exchange treatment. About eight weeks after her admission, she developed status epileptics. Cerebral computed tomography and lumbar puncture did not reveal any abnormal sign. The case reported herein is a MPO-ANCA positive PSS with normotensive renal failure. Generally, PSS rarely reveals neurological sign. This case suggests possibility of association between MPO-ANCA and systemic vasculitis in PSS.

Adult↗
PubMed1997

[A case of rheumatoid arthritis (RA) with drug-induced acute pancreatitis due to mizoribine].

A rare case of mizoribine-induced acute pancreatitis is presented. A 39-year-old female with RA was admitted to our hospital because of upper abdominal pain, fever and the elevation of serum amylase concentration. Acute pancreatitis was diagnosed. Mizoribine (MZB) had been administered for 12 days for the treatment of RA before the onset of pancreatitis. Withdrawal of MZB soon resulted in the improvement of the disease. She was asymptomatic for the next few weeks. The pancreatitis recurred 36 hours after she took MZB again on her own judgement for arthralgia. This clinical course strongly suggested that her pancreatitis was due to MZB. Acute pancreatitis due to MZB has never, to our knowledge, been reported. MZB is commonly used for the treatment of RA. Therefore the clinician should take care for the complication of acute pancreatitis even though it is rare.

Acute Disease↗
PubMed1996

Phosphatidylinositol 3-kinase-independent signal transduction pathway for platelet-derived growth factor-induced chemotaxis.

Platelet-derived growth factor (PDGF)-BB is a potent chemoattractant for mesenchymal cells. Intracellular signal transduction for PDGF-induced chemotactic response has been reported to be dependent on phosphatidylinositol 3-kinase (PI3K) activation. Here, we report a PI3K-independent pathway operating for PDGF-induced chemotaxis in vascular smooth muscle cells and other cell types. Two different PI3K inhibitors, wortmannin (WT, 1 nM-1 microM) and LY294002 (100 nM-10 microM), did not inhibit PDGF-induced chemotaxis in smooth muscle cells and Swiss 3T3 cells, whereas WT inhibited activity of PI3K that were immunopurified from PDGF-stimulated cells as well as PI3K purified from cells that were stimulated with PDGF in the presence of the same concentrations of WT. Similarly, WT (100 nM) abolished the increase in intracellular phosphatidylinositol 3,4,5-triphosphate after PDGF stimulation. Furthermore, Chinese hamster ovary/Deltap85 cells overexpressing a dominant negative p85 subunit of PI3K showed a chemotactic response comparable to that of parental cells while showing a remarkable decrease in PI3K activity. Rapamycin, a specific inhibitor of pp70 S6 kinase, which is one of the well characterized downstreams of PI3K, did not inhibit PDGF-induced chemotaxis. Both WT and LY294002 inhibited PDGF-induced amino acid uptake and actin-stress fiber reorganization and partly inhibited PDGF-induced glucose incorporation in Swiss 3T3 cells. Our findings indicate that, in vascular smooth muscle cells and other cell types, the signal transduction for PDGF-induced chemotaxis is independent of PI3K activity while the signal transduction for PDGF-induced amino acid uptake, glucose incorporation, and cytoskeletal reorganization is dependent on PI3K.

3T3 Cells↗
PubMed1996

Characterization of a 115-kDa protein that binds to SH-PTP2, a protein-tyrosine phosphatase with Src homology 2 domains, in Chinese hamster ovary cells.

SH-PTP2, a non-transmembrane-type protein-tyrosine phosphatase with two Src homology 2 domains, was previously shown to play a positive signaling role in the insulin-induced activation of Ras and mitogen-activated protein kinase. SH-PTP2 was shown to associate with a 115-kDa tyrosine-phosphorylated protein (pp115), as well as with insulin receptor substrate 1, in insulin-stimulated Chinese hamster ovary cells that overexpress human insulin receptors (CHO-IR cells). In vivo and in vitro binding experiments revealed that SH-PTP2 bound to pp115 through one or both of its SH2 domains. The pp115 protein was partially purified from insulin-stimulated CHO-IR cells that overexpress a catalytically inactive SH-PTP2 by a combination of immunoaffinity and lectin-affinity chromatography. A monoclonal antibody to pp115 was then generated by injecting the partially purified protein into mice. Experiments with this monoclonal antibody revealed that pp115 is a transmembrane protein with a domain exposed on the cell surface and that it binds to SH-PTP2 in response to insulin. The insulin receptor kinase appeared to phosphorylate pp115 on tyrosine residues both in vivo and in vitro. The extent of tyrosine phosphorylation of pp115 associated with SH-PTP2 was greatly increased in CHO-IR cells that overexpress catalytically inactive SH-PTP2 compared with that observed in CHO-IR cells overexpressing wild-type SH-PTP2. Furthermore, recombinant SH-PTP2 preferentially dephosphorylated pp115 in vitro, indicating that SH-PTP2 may catalyze the dephosphorylation of phosphotyrosine residues in pp115 after it binds to this protein. These results suggest that pp115 may act as a transmembrane anchor to which SH-PTP2 binds in response to insulin. Furthermore, pp115 may be a physiological substrate for both the insulin receptor kinase and SH-PTP2.

Animals↗
PubMed1996

A role for phosphoinositide 3-kinase in bacterial invasion.

Listeria monocytogenes is a bacterial pathogen that invades cultured nonphagocytic cells. Inhibitors and a dominant negative mutation were used to demonstrate that efficient entry requires the phosphoinositide (PI) 3-kinase p85alpha-p110. Infection with L. monocytogenes caused rapid increases in cellular amounts of PI(3, 4)P2 and PI(3,4,5)P3, indicating that invading bacteria stimulated PI 3-kinase activity. This stimulation required the bacterial protein InlB, host cell tyrosine phosphorylation, and association of p85alpha with one or more tyrosine-phosphorylated proteins. This role for PI 3-kinase in bacterial entry may have parallels in some endocytic events.

Androstadienes↗
PubMed1996

Induction of tolerance in murine autoimmune diabetes by transient blockade of leukocyte function-associated antigen-1/intercellular adhesion molecule-1 pathway.

The present study demonstrated that a short-term administration of mAbs against leukocyte function-associated antigen-1 (LFA-1) and intercellular adhesion molecule-1 (ICAM-1) at critical periods resulted in complete protection of autoimmune diabetes in non-obese diabetic (NOD) mice. When these mAbs were administered for only 6 days at 2 wk of age, neither diabetes nor insulitis was observed at 30 wk of age. It appears that the tolerance against beta cell Ag(s) was induced by this transient blockade of the LFA-1/ICAM-1 pathway. Protective suppressor activity was not enough to prevent diabetes because co-transfer of splenocytes from female NOD mice, which had received these mAbs at 2 wk of age, resulted in only a short delay of the diabetic onset caused by adoptive transfer of splenocytes from acutely diabetic NOD mice. Transfer of these splenocytes to young NOD mice could not also abrogate the spontaneous diabetes and insulitis. Furthermore, cyclophosphamide treatment could not abrogate the protection. When splenocytes from the treated NOD mice were transferred to NOD-SCID mice, none of the recipient mice developed significant insulitis and subsequent overt diabetes, suggesting the absence or the inactivation of diabetogenic effector T cells. However, splenic T cells from the insulitis-free NOD mice that had received the mAb treatment preserved proliferative responses to both islet cells and 65-kDa glutamic acid decarboxylase (GAD65) in vitro. These results suggest that a unique peripheral tolerance was induced by the transient blockade of the LFA-1/ICAM-1 pathway in an early age of NOD mice.

Adoptive Transfer↗
PubMed1996

Protein-free cell culture on an artificial substrate with covalently immobilized insulin.

Insulin was immobilized on a surface-hydrolyzed poly(methyl methacrylate) film. Chinese hamster ovary cells overexpressing human insulin receptors were cultured on the film in the absence of serum or soluble proteins. Small amounts of immobilized insulin (1-10% of the required amount of free insulin) were sufficient to stimulate cell proliferation. In addition, the maximal mitogenic effect of immobilized insulin was greater than that of free insulin. Immobilized insulin activated the insulin receptor and downstream signaling proteins, and this activation persisted for longer periods than that obtained with free insulin, probably explaining the greater mitogenic effect of the immobilized insulin. Finally the immobilized-insulin film was usable repeatedly without marked loss of activity.

Animals↗
PubMed1996

Subcellular trafficking kinetics of GLU4 mutated at the N- and C-terminal.

The glucose transporter isoform, GLUT4, has been expressed in Chinese hamster clones and its subcellular trafficking has been determined following labelling at the cell surface with the impermeant bis-mannose photolabel, 2-N-(1-azi-2,2,2-trifluoroethyl)benzoyl-1,3-bis(D-mannos -4-yloxy)-2-propylamine (ATM-BMPA). ATM-BMPA-tagged GLUT4 leaves the cell surface rapidly and equilibrates to give an internal/surface distribution ratio of approx. 3.5 after 60 min. GLUT4 in which the N-terminal phenylalanine-5 and glutamine-6 are mutated to alanine-N-(FQ-AA) and in which the C-terminal leucine-489 and -490 are mutated to alanine C-(LL-AA) have low internal/surface ratios of 0.64 and 1.24 respectively. If all cell-surface transporters are able to recycle, as would be the case for a two-pool recycling model with a single intracellular pool, then analysis suggests that the wild-type GLUT4 distribution ratio is dependent on endocytosis and exocytosis rate constants of 0.074 and 0.023 min(-1). These values are similar, but not identical, to those found for GLUT4 trafficking in adipocytes. The distribution of the N-(FQ-AA) transporter appears to be due to a decrease in endocytosis with reduced intracellular retention, while the distribution of the C-(LL_AA) transporter appears to be mainly due to poor intracellular retention. These results are also considered in terms of a consecutive intracellular pool model in which GLUT4 targeting domains alter the distribution between recycling endosomes and a slowly recycling compartment. In this case the more rapid apparent exocytosis of the mutated GLUT4 is due to their failure to reach a slowly recycling compartment with a consequent return to the plasma membrane by default. It is suggested that overexpression of transporters increases the proportion that are recycled in this way. Wortmannin is shown to decrease glucose transport activity and cell-surface photolabelled transporters in a manner consistent with an inhibition of transporter recycling. Studies on the rate of loss of transport activity and ATB-BMPA-tagged transporter in wortmannin-treated cells confirm that the N-(FQ-AA) mutant is endocytosed more slowly than the wild-type GLUT4. Taken together, these results suggest that the mutation at either the N- or the C-terminal domain can reduce movement to a slowly recycling intracellular compartment but that neither domain alone is entirely sufficient to produce wild-type GLUT4 trafficking behaviour.

Amino Acid Sequence↗
PubMed1996

Cleavage of vesicle-associated membrane protein (VAMP)-2 and cellubrevin on GLUT4-containing vesicles inhibits the translocation of GLUT4 in 3T3-L1 adipocytes.

We have identified VAMP isoforms, VAMP-2 and cellubrevin, on GLUT4-containing vesicle membranes isolated from 3T3-Ll adipocytes. These proteins translocate from a low density microsomal fraction to the plasma membrane upon insulin stimulation in a fashion similar to GLUT4. VAMP-1 was not detected in this low density microsomal fraction nor on purified GLUT4-containing vesicles. In streptolysin-O permeabilized 3T3-L1 adipocytes, both VAMP-2 and cellubrevin were cleaved with botulinum neurotoxin isoform B, BoNTx/B. In addition, BoNTx/B partially inhibited insulin-stimulated GLUT4 translocation and glucose transport activity. We conclude that the synaptobrevin isoforms are important components of the insulin-dependent translocation of GLUT4 to the cell surface in adipocytes.

3T3 Cells↗
PubMed1996

Interaction of Shc with adaptor protein adaptins.

The role of Shc as a substrate of receptors for growth factors and cytokines is well established. To gain further insight into the function of Shc in signal transduction, we used an affinity method to identify potential Shc-binding proteins. Incubation of bovine brain lysates with a glutathione S-transferase (GST)-Shc fusion protein immobilized on glutathione-Sepharose beads resulted in the binding of cellular proteins of approximately 115, 110, and 100 kDa as well as those of 50 and 17 kDa. Amino acid sequencing of tryptic peptides revealed that the 100-kDa protein was almost identical to beta-adaptin and that the 110- and 115-kDa proteins were almost identical to alphaA-adaptin. Using immunoblot analysis, anti-alpha-adaptin antibody recognized several proteins of 100 approximately 115 kDa, and anti-beta-adaptin antibody recognized a 100-kDa protein, suggesting that alphaA-, alphaC-, and beta-adaptins are bound to the GST-Shc fusion protein. Immunoblot analysis with anti-alpha-adaptin antibody revealed that alpha-adaptin was coimmunoprecipitated with Shc from PC12, KB, and COS cell lysates, suggesting a specific interaction of Shc and adaptins in intact cells. A binding study using mutant GST-Shc fusion proteins revealed that the collagen homologous region (amino acids 233-377) of Shc was required for adaptin binding. Conversely, the collagen homologous region of Shc inhibited the binding of adaptins to GST-Shc. In addition, adaptin was able to bind mutant fusion proteins containing amino acids 233-369, 233-355, 346-369, and 346-355 of Shc, but failed to bind a mutant containing amino acids 233-345, suggesting that amino acids 346-355 (RDLFDMKPFE) in the collagen homologous region of Shc are required for adaptin binding. Thus, this study indicates the specific interaction of Shc with alpha- and beta-adaptin components of plasma membrane adaptor proteins that are thought to be involved in receptor endocytosis.

Adaptor Protein Complex 2↗