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Biomedical subjects

Y Inoue

Publications and source records attributed to Y Inoue.

At least 631 records · Page 35Linked to original sources
PubMed1998

Regional differences in the effect of exercise intensity on thermoregulatory sweating and cutaneous vasodilation.

To investigate regional body differences in the effect of exercise intensity on the thermoregulatory sweating response, nine healthy male subjects (23.2 +/- 0.4 year) cycled at 35, 50 and 65% of their maximal O2 uptake (VO2max) for 30 min at an ambient temperature of 28.3 +/- 0.2 degrees C and a relative humidity of 42.6 +/- 2.4%. Local sweating rate (msw) on the forehead, chest, back, forearm and thigh increased significantly with increases in the exercise intensity from 35 to 50% VO2max and from 50 to 65% VO2max (P < 0.05). The mean values for the density of activated sweat glands (ASG) at 50 and 65% VO2max at the five sites were significantly greater than at 35% VO2max. The mean value of the sweat output per gland (SGO) also increased significantly with the increase in exercise intensity (P < 0.05). The patterns of changes in ASG and SGO with an increase in exercise intensity differed from one region of the body to another. Although esophageal temperature (Tes) threshold for the onset of sweating at each site was not altered by exercise intensity, the sensitivity of the sweating response on the forehead increased significantly from 35 to 50 and 65% VO2max (P < 0.05). The threshold for cutaneous vasodilation tend to increase with exercise intensity, although the exercise intensity did not affect the sensitivity (the slope in the relationship Tes vs. percentage of the maximal skin blood flow) at each site. Tes threshold for cutaneous vasodilation on the forearm was significantly higher at 65% VO2max than at either 35 or 50% VO2max, but this was not observed at the other sites, such as on the forehead and chest. These results suggest that the increase in msw seen with an increasing intensity of exercise depends first on ASG, and then on SGO, and the dependence of ASG and SGO on the increase in msw differs for different body sites. In addition, there are regional differences in the Tes threshold for vasodilation in response to an increase in exercise intensity.

Adult↗
PubMed1998

Modulation of melanocyte-stimulating hormone receptor expression on normal human melanocytes: evidence for a regulatory role of ultraviolet B, interleukin-1alpha, interleukin-1beta, endothelin-1 and tumour necrosis factor-alpha.

Melanocyte-stimulating hormone (MSH) receptor binding activity and melanocortin-1 receptor (MC1-R) gene expression on normal human melanocytes have been studied as responses to the effects of ultraviolet B (UVB), interleukin-1 (IL-1), endothelin-1 (ET-1) and tumour necrosis factor-alpha (TNF-alpha), which are known as UV sensitive regulators of melanocytic function. MSH receptor (MSH-R) binding activity was upregulated by UVB, IL-1alpha, -1beta and ET-1, but was downregulated by TNF-alpha. Northern blot analysis showed that MC1-R mRNA expression was induced 24 h after UVB irradiation in a dose-dependent manner, and that 24-h treatment with ET-1 also induced an expression of MC1-R mRNA, whereas TNF-alpha downregulated the expression. In addition, IL-1alpha and -1beta have a small but real inductive effect on MC1-R mRNA expression. Taken together, our results suggest a model in which higher MC1-R mRNA expression is accompanied by upregulation of MSH-R binding activity, and enhanced by UVB or cytokines sensitive to UVB. Such a regulatory system would enable normal human melanocytes to respond to MSH more efficiently and induce an increase of melanization of the skin through the MSH/MSH-R system after UVB radiation.

Adolescent↗
PubMed1998

Anti-DNA IgA autoantibodies are spontaneously generated in mouse Peyer's patches.

IgA antibodies in the mucosal immune system are produced specifically to environmental antigens such as virus and bacteria, and possibly to some food components, which will provide a potential luminal antigen, DNA. To study the immune response to DNA in the gut, we established B-cell hybridomas producing IgA monoclonal antibodies (mAb) from Peyer's patches (PP) of non-immunized, non-autoimmune, specific pathogen-free BALB/c mice, and examined their specificity by enzyme-linked immunosorbent assay (ELISA). Three mAb out of 18 bound strongly to self, bacterial and synthetic DNA, with Kd of about 10-7 m. One of the three mAb also reacted with the histone component and another reacted with some mouse food component. The VH genes of these three mAb have not previously been reported to have anti-DNA specificity, and carry putative somatically mutated sites favouring DNA binding in CDR. The features resemble those of anti-DNA antibodies found in human and murine models of systemic lupus erythmatosus (SLE), and are indicative of an antigen-driven selection process. Our findings suggest that even in normal healthy animals, anti-DNA antibodies of IgA isotype can be produced in certain peripheral environments such as in PP by spontaneous antigenic stimulation.

Amino Acid Sequence↗
PubMed1998

Selective scarcity of NMDA receptor channel subunits in the stratum lucidum (mossy fibre-recipient layer) of the mouse hippocampal CA3 subfield.

Hippocampal synapses express two distinct forms of the long-term potentiation (LTP), i.e. NMDA receptor-dependent and -independent LTPs. To understand its molecular-anatomical basis, we produced affinity-purified antibodies against the GluRepsilon1 (NR2A), GluRepsilon2 (NR2B), and GluRzeta1 (NR1) subunits of the N-methyl-D-aspartate (NMDA) receptor channel, and determined their distributions in the mouse hippocampus. Using NMDA receptor subunit-deficient mice as the specificity controls, section pretreatment with proteases (pepsin and proteinase K) was found to be very effective to detect authentic NMDA receptor subunits. As the result of modified immunohistochemistry, all three subunits were detected at the highest level in the strata oriens and radiatum of the CA1 subfield, and high levels were also seen in most other neuropil layers of the CA1 and CA3 subfields and of the dentate gyrus. However, the stratum lucidum, a mossy fibre-recipient layer of the CA3 subfield, contained low levels of the GluRepsilon1 and GluRzeta1 subunits and almost excluded the GluRepsilon2 subunit. Double immunofluorescence with the AMPA receptor GluRalpha1 (GluR1 or GluR-A) subunit further demonstrated that the GluRepsilon1 subunit was colocalized in a subset, not all, of GluRalpha1-immunopositive structures in the stratum lucidum. Therefore, the selective scarcity of these NMDA receptor subunits in the stratum lucidum suggests that a different synaptic targeting mechanism exerts within a single CA3 pyramidal neurone in vivo, which would explain contrasting significance of the NMDA receptor channel in LTP induction mechanisms between the mossy fibre-CA3 synapse and other hippocampal synapses.

Animals↗
PubMed1998

Motor discoordination and increased susceptibility to cerebellar injury in GLAST mutant mice.

To study the function of GLAST, a glutamate transporter highly expressed in the cerebellar Bergmann astrocytes, the mouse GLAST gene was inactivated. GLAST-deficient mice developed normally and could manage simple coordinated tasks, such as staying on a stationary or a slowly rotating rod, but failed more challenging task such as staying on a quickly rotating rod. Electrophysiological examination revealed that Purkinje cells in the mutant mice remained to be multiply innervated by climbing fibres even at the adult stage. We also found that oedema volumes in the mutant mice increased significantly after cerebellar injury. These results indicate that GLAST plays active roles both in the cerebellar climbing fibre synapse formation and in preventing excitotoxic cerebellar damage after acute brain injury.

ATP-Binding Cassette Transporters↗
PubMed1998

Patterns of expression for the mRNA corresponding to the four isoforms of phospholipase Cbeta in mouse brain.

Ligand binding to neurotransmitter and hormone receptors which couple to the Gq subclass of GTP-binding protein leads to the activation of phospholipase Cbeta (PLCbeta) which hydrolyses phosphatidyl-inositol 4,5-bisphosphate, yielding a pair of second messengers, diacylglycerol and inositol 1,4,5-trisphosphate (IP3). The expression of PLCbeta1-4 mRNAs was comparatively examined by in situ hybridization in the mouse brain. In adults, PLCbeta1 mRNA was expressed predominantly in the telencephalon, including the cerebral cortex, hippocampus, amygdala, lateral septum and olfactory bulb, with little expression in most thalamic nuclei. PLCbeta2 mRNA was distributed in the white matter, suggesting its expression in non-neuronal cells, most likely oligodendrocytes. PLCbeta3 mRNA was specifically expressed in cerebellar Purkinje cells. The highest levels of PLCbeta4 mRNA were detected in Purkinje cells. High levels of PLCbeta4 mRNA were also found in the thalamus and medial septum, whereas weak signals were detected in most telencephalic regions, thus showing an expression pattern almost reciprocal to that of PLCbeta1 mRNA. During development, such characteristic regional expression of PLCbeta1 and PLCbeta4 were observed starting in late foetal stages, while specific expression of PLCbeta2 and PLCbeta3 appeared in early postnatal stages. We conclude that despite the existence of four PLCbeta isoforms, only one or two of them is expressed in individual neurons and glial cells. The distinct expression of PLCbetas provides a molecular basis for analysing the nature of the specific signal transduction pathway leading to the production of diacylglycerol and IP3 in distinct cell types and in different regions of the brain.

Aging↗
PubMed1998

Semi-quantitative analysis of telomerase activity in exfoliated human urothelial cells and bladder transitional cell carcinoma.

OBJECTIVE: To determine the utility of detecting telomerase activity in transitional cell bladder cancer, using the telomeric repeat amplification protocol (TRAP) assay, and thus provide a test for the detection and monitoring of bladder cancer, especially low-grade tumours. PATIENTS, SUBJECTS AND METHODS: Telomerase activity was assayed in bladder cancer tissues and the exfoliated urothelial cells from 29 patients with bladder cancer, 10 with benign disease, and in 10 healthy subjects using the TRAP assay. The levels were assessed semiquantitatively by calculating the ratio to an internal telomerase assay standard. RESULTS: Telomerase activity was very low in the exfoliated urothelial cells from all healthy subjects and patients with benign disease, with a mean (SD) ratio of 0.25 (0.03) and 0.33 (0.04), respectively. A threshold ratio of 0.4 was calculated as the mean +/- 2 SD of the telomerase activity level of the exfoliated urothelial cells from patients with benign disease. Using this threshold, telomerase activity was negative in exfoliated urothelial cells from all benign cases (100% specificity) and positive in all 26 bladder cancer tissue samples assayed. In tumour tissue, telomerase activity was not associated with tumour grade, size or stage. Telomerase activity in exfoliated urothelial cells from patients with bladder cancer was positive in 25 of 29 samples (86% sensitivity). The sensitivity of telomerase activity in exfoliated cells was seven of nine in G1, 10 of 12 in G2 and all eight G3 tumours; the corresponding sensitivity for voided urine cytology in G1, G2 and G3 tumours was two of nine, six of 12 and six of eight, respectively. CONCLUSION: These results indicate that telomerase activation occurs as an early step in carcinogenesis and the semi-quantitative analysis of telomerase activity in exfoliated urothelial cells could be a minimally invasive and useful method for detecting bladder cancer, even in low-grade tumours.

Aged↗
PubMed1998

Platelet-activating factor acetylhydrolase gene mutation in Japanese nephrotic children.

BACKGROUND: Platelet-activating factor (PAF) may be involved in the pathogenesis of steroid-responsive nephrotic syndrome (SRNS). PAF is degraded to inactive products by PAF acetylhydrolase. We have investigated whether PAF acetylhydrolase gene mutation is involved in SRNS in Japanese children. METHODS: We identified a point mutation in the PAF acetylhydrolase gene (G994T) using the polymerase chain reaction in 101 Japanese children with SRNS and 100 healthy Japanese. RESULTS: There was no difference in the genotype and allele frequencies between patients with SRNS and normal controls. The mean number of relapses during the first year after onset was significantly higher in the 26 patients who were heterozygous for the mutant allele (GT) than in 75 wild-type homozygotes (GG) (2.61 +/- 1.98 vs. 1.33 +/- 1.35; P = 0.0019). CONCLUSIONS: We conclude that analysis of the PAF acetylhydrolase gene mutation at position 994 in Japanese children with SRNS allows the identification of patients who are more likely to have a disease relapse.

1-Alkyl-2-acetylglycerophosphocholine Esterase↗
PubMed1998

Effects of gamma-rays on the populations of the steady-state ecological microcosm.

PURPOSE: To investigate the dose-response of an aquatic microcosm exposed to gamma-rays and to test the suitability of microcosms for elucidation of the mechanisms that account for such ecological effects. MATERIALS AND METHODS: The microcosm used in this study consisted of algae Euglena gracilis Z as a producer, protozoa Tetrahymena thermophila B as a consumer and bacteria Escherichia coli DH5alpha as a decomposer. After the steady-state microcosm was irradiated with 60Co gamma-rays at various dose levels, the population densities of each species were measured. RESULTS: Irradiation at up to 100 Gy did not affect the population of the microcosm except for a temporary decrease of E. coli just after irradiation. At 500 or 1000Gy, E. coli died out just after irradiation. Only Eu. gracilis and T. thermophila could survive. Their populations, however, decreased compared with that of each control, except for a temporary increase of T. thermophila after 1000 Gy irradiation. These population changes were attributable to the extinction of E. coli in addition to the direct effects of radiation. Irradiation at 5000 Gy extinguished all species in the microcosm. CONCLUSIONS: The response of the microcosm to radiation was dose-dependent over a range of high doses. The microcosm was also shown to be suitable for examining not only direct effects but also secondary effects.

Animals↗
PubMed1998

Homozygosity mapping of a gene responsible for gelatinous drop-like corneal dystrophy to chromosome 1p.

Gelatinous drop-like corneal dystrophy (GDLD) is a rare autosomal recessive disorder characterized clinically by grayish corneal deposits of amyloid and by severely impaired visual acuity. Most patients require corneal transplantation. To localize a gene responsible for GDLD, we performed linkage analysis of 10 consanguineous Japanese families with a total of 13 affected members. Homozygosity mapping provided a maximum LOD score of 9.80 at the D1S2741 marker locus on the short arm of chromosome 1. Haplotype analysis further defined the disease locus within a region of approximately 2.6 cM between D1S2890 and D1S2801.

Chromosome Mapping↗
PubMed1998

Possible involvement of Fas-mediated apoptosis in eye muscle tissue from patients with thyroid-associated ophthalmopathy.

In order to investigate the possible involvement of apoptosis in the pathogenesis of thyroid-associated ophthalmopathy (TAO), we studied the expression of Fas, Fas ligand (FasL), and Bcl-2 in extraocular muscle tissues from patients with TAO by immunohistochemistry using monoclonal antibodies against Fas, FasL, and Bcl-2. Apoptosis was detected by in situ end-labeling of fragmented DNA. Apoptosis was detected in extraocular muscle tissues from 17 of 19 patients with TAO and, to a smaller degree in 4 of 7 normal control subjects. The mean percentages of apoptotic nuclei were 12.1% in TAO eye muscle fibers and 16.4% in TAO interstitial cells, compared with 2.2% and 0.4% in normal eye muscle fibers and interstitial cells, respectively. The percentage of apoptotic nuclei in eye muscle fibers correlated with the enlargement of eye muscle tissue (r = 0.47, p < 0.05). Fas was demonstrated on the surfaces of extraocular muscle fibers in 11 of 18 patients with TAO, but not in normal extraocular muscle tissues. Neither TAO nor normal extraocular muscle tissues expressed Bcl-2. FasL was detected in infiltrating mononuclear cells in extraocular muscle tissue from a patient with TAO. These data suggest that Fas-mediated apoptosis may occur in extraocular muscle tissue from patients with TAO and may be involved in the late stage of TAO.

Adult↗
PubMed1998

Cloning and expression of an alpha-2,8-polysialyltransferase (STX) from Xenopus laevis.

Polysialic acid (polySia) is a carbohydrate structure found on neural cell adhesion molecules (N-CAM). Two polysialyltransferases (polySiaTs) that catalyze synthesis of polySia have been described, and designated PST-1/PST/ST8SiaIV and STX/ST8SiaII. We cloned a polySiaT (xSTX) from a nonmammalian vertebrate, Xenopus laevis . xSTX had 80% amino acid similarity to the rat STX. This clone induced polySia expression when transfected into polySia-negative COS-1 cells. Northern blot analysis of whole embryos at different stages of development revealed that xSTX mRNA was most abundantly expressed in premetamorphic stages. The relative level of xSTX and N-CAM mRNAs was also examined and found to change in parallel to the extent of polysialylation on N-CAM. In adult tissues, the expression of xSTX mRNA was restricted to brain, eye and heart, which also expressed polySia. These results suggest that xSTX is the major enzyme responsible for the synthesis of polysialylated N-CAM in embryos at certain stages of development and also in adult tissues.

Amino Acid Sequence↗
PubMed1998

Guanidine hydrochloride-induced changes of the E2 inner core of the Bacillus stearothermophilus pyruvate dehydrogenase complex.

The limited proteolysis of the Bacillus stearothermophilus pyruvate dehydrogenase complex by V8 protease yields its core structure solely composed of lipoate acetyltransferase (E2) fragments. The changes in the core with guanidine hydrochloride (GdnHCl) were biphasic: below 0.8 M (first) and above 1.0 M (second) GdnHCl. The changes in the first phase were slight but significant: decreases in ellipticity and light scattering, and an increase in E2 activity. Insignificant changes in the molecular shape and size of the core were detected on fluorescence spectroscopy, ultracentrifugation, gel filtration, and electron microscopy. On the other hand, the changes in the second phase were drastic; the core was disassembled and denatured.

Chromatography, Gel↗
PubMed1998

Interaction mode of the phe-phenyl group of thrombin receptor-tethered ligand SFLLRNP in receptor activation.

Phenylalanine at position 2 of thrombin receptor-tethered ligand peptide (SFLLRNP) is crucially important for the activation of thrombin receptor. Its substitution by para-fluorophenylalanine [(p-F)Phe] enhanced several times the activity in human epithelial-like SH-EP cells [Nose et al. (1993) Biochem. Biophys. Res. Commun. 193, 694-699]. To clarify the interaction mode of Phe-2-phenyl in receptor activation, a series of analogs having chemical modifications on the benzene ring of Phe-2 were synthesized and examined for their ability to induce the aggregation of human platelets. When the fluorine atom was placed at the meta or ortho position, the resulting analogs exhibited considerably diminished activity (about 10-20% of para-derivative), indicating that the substitution is allowed only at the para position. The derivative with pentafluorophenylalanine was totally devoid of activity. These results suggested that Phe-2 requires hydrogen atom(s) on the benzene ring presumably for interaction with the receptor. No activity enhancement was observed for analogs with para-chloro-, bromo-, or iodophenylalanine, indicating the importance of the high electronegativity of fluorine to intensify the dipole of CH(s) remaining in the Phe-2-benzene ring. Inactivity of analogs having para-iodophenylalanine and homophenylalanine indicated the importance of the size of para substituents, and the placement of hydroxyl, nitro, and trifluoromethyl groups at the para position led to no activity. The interaction of Phe-2 of SFLLRNP appeared to be structurally restricted to a limited space in the receptor. The results suggested the presence of face-to-edge pi-pi interaction based upon the CH/pi interaction between the ligand Phe-2-phenyl group and the receptor aromatic group.

Amino Acid Sequence↗
PubMed1998

Breast reconstruction after mastectomy without additional scarring: application of endoscopic latissimus dorsi muscle harvest.

Breast reconstruction with the latissimus dorsi muscle flap combined with a saline-filled implant was performed. Using an endoscope, additional operative scarring due to muscle harvesting was avoided. The operative techniques were easier than usual endoscopic surgery because most of the procedures were performed under direct vision. The procedures are presented in this article.

Adult↗