Biomedical subjects

Hiroshi Nishiyama

Publications and source records attributed to Hiroshi Nishiyama.

8 recordsLinked to original sources

PubMed2006

Influence of SNPs in cytokine-related genes on the severity of food allergy and atopic eczema in children.

Although many single nucleotide polymorphism (SNP) studies have reported an association of atopy, allergic diseases and total serum immunoglobulin E (IgE) levels, almost all of these studies sought risk factors for the onset of these allergic diseases. Furthermore, many studies have analyzed a single gene and hardly any have analyzed environmental factors. In these analyses, the results could be masked and the effects of other genes and environmental factors may be decreased. Here, we described the correlation between four genes [interleukin (IL)-4 (C-590T), IL-4 receptor (A1652G), FCER1B (G6842A) and STAT6 (G2964A)] in connection with IgE production; the role of IL-10 (C-627A) as a regulatory cytokine of allergy; and the severity of food allergy (FA) and atopic eczema (AE) in 220 Japanese allergic children. In addition to these SNPs, environmental factors, i.e., patient's attitude, indoor environment, and so on, were also investigated in this study. Our study was retrospective, and the correlation was analyzed by our defined clinical scores divided into three terms: worst symptoms, recent symptoms and general amelioration at the most recent examination during the disease course. Our results indicated that IL-10 AA, the genotype with lower IL-10 production, is associated with higher IgE levels in the serum (p < 0.0001, estimate; 0.912). Marginal liver abnormalities were observed in the subject group with both FA and AE (p < 0.1191, estimate; 0.1490). Our defined clinical scores enabled evaluation of various aspects of disease severity. Based on the scores, while no single SNP selected in this study determined severity, the combination of the SNP with laboratory data and environmental factors appeared to determine severity.

Adolescent↗

PubMed2004

New and highly efficient method for silkworm transgenesis using Autographa californica nucleopolyhedrovirus and piggyBac transposable elements.

We have developed a new method for the transgenesis of the silkworm, Bombyx mori. This method couples the use of recombinant baculoviruses with the use of the piggyBac transposable element. One recombinant AcNPV, designated the helper virus, is designed to express the piggyBac transposase under the control of the Drosophila hsp70 promoter. Another recombinant AcNPV encoded the gene to be incorporated into the silkworm genome, in this case a green fluorescent protein (GFP) gene, under the control of B. mori actin A3 promoter and franked by the piggyBac inverted terminal repeats. Preblastoderm eggs were inoculated with a fine needle coated with a mixture of these two recombinant baculoviruses. Most of the inoculated larvae hatched and a high proportion of the newly hatched G0 larvae expressed the GFP marker. Transgenesis was confirmed by Southern blot analysis of G1 insects, sequencing the insertion site junctions isolated by inverse PCR, and the marker segregated in Mendelian fashion, as evidenced by the appearance of green fluorescence in G2 insects. Thus, transgenic silkworms were easily and efficiently obtained using this new method.

Animals↗

PubMed2004

Differential maturation of climbing fiber innervation in cerebellar vermis.

Folding of the brain surface is a general morphological adaptation to maximize surface area in a limited cranial volume. Surface folding is present not only in the neocortex but also in the cerebellar cortex. This folding creates subdivisions of the cortical surface: the sulci, the gyri, and the straight bank region, which is interposed. Is cortical folding only the solution to a surface-volume problem or does it also confer functional differences on the subdivisions that are created by this geometry? Here we have used the innervation of Purkinje cells by climbing fibers as a model system to explore potential functional differences. Purkinje cells are innervated by multiple climbing fibers at birth but undergo an activity-dependent refinement, such that by postnatal day (P) 21, most are contacted by a single climbing fiber. Using whole-cell recording from slices of cerebellar vermis derived from juvenile (P18-25) or adult (P60-83) mice, we found that significantly more Purkinje cells in the sulcus were innervated by multiple climbing fibers than in the gyrus or bank subdivisions; however, the basic properties of climbing fiber-Purkinje cell EPSCs such as kinetics, amplitude, and paired-pulse ratio were similar across cortical subdivisions. To search for a morphological correlate of differential multiple climbing fiber innervation, we labeled climbing fibers and performed reconstructions of immunofluorescent images. These revealed that, unlike the bank-gyrus subdivisions, most of the climbing fibers in the sulcus do not innervate the superficial molecular layer. These findings suggest that the subdivisions of the cerebellar cortex produced by folding may create functionally distinct entities.

Afferent Pathways↗

PubMed2004

Prevalence of obstructive sleep apnoea and periodic limb movement in 45 subjects with heart transplantation.

BACKGROUND: Obesity, a major risk factor for obstructive sleep apnoea, is common after cardiac transplantation. Case reports have shown development of obstructive sleep apnoea in cardiac transplantation recipients. The present study represents the first systematic evaluation of sleep disorders after cardiac transplantation. OBJECTIVE: To determine the prevalence and clinical impact of sleep disorders in a cohort of cardiac transplant recipients. METHODS: This was a cross-sectional study at the Veterans Affairs Medical Center. Forty-five of 60 eligible subjects agreed to take part in the study. Polysomnography, sleep and health survey questionnaires, and laboratory tests were recorded. RESULTS: Thirty-six percent had obstructive sleep apnoea-hypopnoea with an index of 15 or more per hour. The average apnoea-hypopnoea index was about 50+/-27 (SD) per hour. Sleep apnoea resulted in arterial oxyhaemoglobin desaturation, excessive arousals, unrefreshing sleep, excessive daytime sleepiness, poor health-related quality of life, and hypertension (all P values <0.05). Weight gain since transplantation was significantly greater in recipients with obstructive sleep apnoea than those without. Thirty-three percent of patients had periodic limb movement with an index of >?15/hour and an average of 55+/-43/hour. Forty-five percent of these patients had restless legs syndrome. CONCLUSION: Thirty-six percent of cardiac transplant recipients have moderate to severe obstructive sleep apnoea. Sleep apnoea results in disrupted sleep, desaturation and impaired quality of life. Polysomnography should be routinely considered in the ongoing management of most cardiac transplant recipients. Treatment of obstructive sleep apnoea may improve quality of life and other outcomes of cardiac transplantation.

Cohort Studies↗

PubMed2002

Normal development of serotonergic neurons in mice lacking S100B.

S100B, a glia-derived calcium binding protein, exhibits strong neurite extension activity in cultured serotonergic neurons. Using S100B-knockout mice, we examined whether this protein possesses in vivo serotonergic trophic activity. The distribution of serotonergic fibers, determined by immunohistochemistry, in the brains of S100B-knockout mice was quite similar to that of wild-type mice. Furthermore, the content of serotonin and its metabolite 5-hydroxyindole-3-acetic acid in knockout mice was also indistinguishable from those of wild-type mice. Our findings argue against the hypothesis that S100B has a crucial role in neurite extension of serotonergic neurons.

Animals↗

PubMed2002

Glial protein S100B modulates long-term neuronal synaptic plasticity.

Glial cells are traditionally regarded as elements for structural support and ionic homeostasis, but have recently attracted attention as putative integral elements of the machinery involved in synaptic transmission and plasticity. Here, we demonstrate that calcium-binding protein S100B, which is synthesized in considerable amounts in astrocytes (a major glial cell subtype), modulates long-term synaptic plasticity. Mutant mice devoid of S100B developed normally and had no detectable abnormalities in the cytoarchitecture of the brain. These mutant mice, however, had strengthened synaptic plasticity as identified by enhanced long-term potentiation (LTP) in the hippocampal CA1 region. Perfusion of hippocampal slices with recombinant S100B proteins reversed the levels of LTP in the mutant slices to those of the wild-type slices, indicating that S100B might act extracellularly. In addition to enhanced LTP, mutant mice had enhanced spatial memory in the Morris water maze test and enhanced fear memory in the contextual fear conditioning. The results indicate that S100B is a glial modulator of neuronal synaptic plasticity and strengthen the notion that glial-neuronal interaction is important for information processing in the brain.

Animals↗

PubMed2002

Distribution of phosphorylated glial fibrillary acidic protein in the mouse central nervous system.

BACKGROUND: Glial fibrillary acidic protein (GFAP) is the principal component of intermediate filaments (IFs) in mature astrocytes in the central nervous system (CNS). Like other IF proteins, GFAP has multiple phosphorylation sites in the N-terminal head domain. The distribution of phospho-GFAP in vivo has not been elucidated. RESULTS: We generated Gfap(hwt) knock-in mice, in which the coding region for the head domain of GFAP is replaced with the corresponding human sequence. In combination with a series of monoclonal antibodies (mAbs) reactive to human phospho-GFAP, we visualized the distribution of phospho-GFAP in vivo in mice. GFAP phosphorylated at Thr7, Ser8 and/or Ser13 increased postnatally in the CNS of these mice. Limited populations of GFAP-positive astrocytes were labelled with anti-phospho-GFAP mAbs in most brain areas, whereas almost all the astrocytes in the optic nerve and spinal cord were labelled. Astrocytes in the subventricular zone and rostral migratory stream preferentially contained phospho-GFAP. In a cold injury model of the cerebral cortex, we detected phospho-GFAP in reactive astrocytes at 2-3 weeks after the injury. CONCLUSIONS: Phospho-GFAP provides a molecular marker indicating the heterogeneity of astrocytes, and Gfap(hwt) knock-in mice will aid in monitoring intracellular conditions of astrocytes, under various conditions. Our results suggest that the phosphorylation of GFAP plays a role in non-dividing astrocytes in vivo.

Animals↗

PubMedDate not supplied

Diagnosing endometrial carcinoma with cervical involvement by cervical cytology.

OBJECTIVE: To assess the relationship of a cervical cytologic diagnosis based on number, size and degeneration of malignant clusters and necrotic background to cervical involvement of endometrial carcinoma. STUDY DESIGN: Cervical smears of 53 women with endometrial carcinoma were evaluated for cervical involvement. The cytologic diagnosis was compared with actual involvement, and accuracy was calculated. Retrospectively, cytologic features, including number, size and degeneration of malignant clusters and necrotic background, were analyzed in involved and noninvolved cases. RESULTS: Cervical involvement was confirmed in 15 patients (28.3%). The number and size of malignant clusters in the involved cases were significantly larger than those in the noninvolved cases (P < .001 and < .01, respectively). The proportion of degenerated malignant cells and necrotic background in involved cases were significantly higher than those in noninvolved cases (P < .05). Cytologic diagnosis had a sensitivity and specificity of 62.5% and 86.8%, respectively. CONCLUSION: Cervical smears of involved cases revealed a large number and large size of malignant clusters. These findings support cytologic diagnosis based on number, size and degeneration of malignant cells and necrotic background. Cervical cytology is useful to exclude cervical involvement because of its high specificity and can help detect cervical involvement because of its moderately high sensitivity.

Adult↗