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Biomedical subjects

M Kobayashi

Publications and source records attributed to M Kobayashi.

At least 91 records · Page 5Linked to original sources
PubMed2003

Impact of postural deformities and spinal mobility on quality of life in postmenopausal osteoporosis.

The objective of the study was to evaluate the impact of postural deformities and spinal mobility on quality of life (QOL) in patients with spinal osteoporosis. A total of 157 postmenopausal women aged over 60 years with osteoporosis were divided into five groups according to their postural deformities: round back (RB, n=41), hollow round back (HRB, n=33), whole kyphosis (WK, n=40), lower acute kyphosis (LAK, n=18), and normal posture (NP, n=25). QOL was evaluated using the Japanese Osteoporosis QOL Questionnaire (JOQOL) proposed by the Japanese Society for Bone and Mineral Research. This questionnaire contains six domains, with higher scores indicating higher levels of QOL. The number of vertebral fractures, thoracic kyphosis and lumbar lordosis angles, and spinal range of motion (ROM) during maximum flexion and extension were also measured with radiographs. Total QOL scores in RB, HRB, WK, and LAK groups were significantly lower than those in the NP group, and those in WK group were even lower compared with the other groups ( P<0.05). All the groups with postural deformities, but not the NP group, showed significant positive correlations between total QOL score and spinal ROM (0.521</= r</=0.747, P<0.05). Total QOL score showed a significant correlation with age, number of vertebral fractures, lumbar lordosis angle, and spinal ROM in a total of 157 patients. However, multiple regression analysis revealed that spinal ROM best correlated with total QOL score. We concluded that QOL in patients with osteoporosis was impaired by postural deformities, especially by whole kyphosis, and that spinal mobility has a strong effect on QOL in these patients.

Activities of Daily Living↗
PubMed2003

Lytic infection of Epstein-Barr virus (EBV) in hemophagocytic syndrome associated with EBV-induced lymphoproliferative disorder.

This report describes lytic infection with Epstein-Barr virus (EBV) in three cases of hemophagocytic syndrome (HPS) presumably associated with EBV-induced lymphoproliferative disorder. All cases were previously healthy females with ages ranging from 52 to 87 years who showed a fulminant clinical course with accompanying fever, liver dysfunction, and disseminated intravascular coagulation. Cases 1 and 2 showed proliferation of atypical T lymphocytes, and case 3 showed proliferation of atypical B lymphocytes. Hemophagocytic histiocytes were observed in the bone marrow, lymph nodes, spleen, and liver. Atypical lymphocytes in all cases showed a positive reaction for both EBV-encoded small RNA (EBER) indicating latent infection with EBV and immediate early mRNAs of the Bam HI fragment of lower stranded frame (BHLF), indicating lytic infection by in situ hybridization. Interestingly, BHLF-positive cells were predominant in all cases. It is possible that reactivation of EBV infection may be involved in triggering the induction of cytokines and abnormal activation of histiocytes.

Aged↗
PubMed2003

Immunosuppressive therapy with antithymocyte globulin and cyclosporine for prolonged marrow failure after hemophagocytic syndrome.

We describe a patient with typical hemophagocytic syndrome (HPS) in whom pancytopenia was refractory to steroid pulse therapy. He was successfully treated with immunosuppressive therapy using antithymocyte globulin (ATG) and cyclosporine (CyA), which is known to be effective for aplastic anemia (AA). Activation of histiocytes occurs in HPS as a response to several cytokines produced by activated T lymphocytes, while apoptosis of hematopoietic stem cells in AA is caused by T lymphocyte-derived cytokines. The response of this patient indicated that both diseases may have some similar immune-mediated conditions involving the activation of T lymphocytes and that intensive immunosuppressive therapy with ATG and CyA might be a useful strategy for steroid-resistant HPS.

Adult↗
PubMed2003

Secondary polycythemia as a paraneoplastic syndrome of testicular seminoma.

A 45-year-old man was referred to our hospital because of polycythemia. A physical examination revealed a large tumor in his scrotum enlarged to the size of 13 x 10 cm. A laboratory examination revealed severe erythrocytosis with a red blood cell count of 6,820 x 10(9)/L, a hemoglobin concentration of 21.2 g/dL, and a hematocrit of 59.8%. The total red cell volume was increased. A right radical orchidectomy was done with minimum bleeding, and he was diagnosed as having pure seminoma. After the operation, polycythemia improved spontaneously. Polycythemia is a rare complication of seminoma and only two cases have been reported previously. The precise mechanism of polycythemia in our patient could not be clearly evaluated, but clinical course did indicate a close relationship between two distinct disorders.

Hematologic Tests↗
PubMed2003

The combination of angiogenesis and blood vessel invasion as a prognostic indicator in primary breast cancer.

This study was undertaken to examine the interaction between the combination of angiogenesis and blood vessel invasion (BVI) and haematogenous metastasis, and to determine the prognostic significance of that combination in predicting 20-year relapse-free survival (RFS) and overall survival (OS) rates in primary breast cancer. Five hundred and nine patients were studied. We investigated 11 factors, including average microvessel count (AMC)/BVI, lymph-node status (n), clinical tumour size (T), histological grade (HG), lymphatic vessel invasion (LVI), p53, proliferating cell nuclear antigen (PCNA), c-erbB-2, mitotic index (MI), apoptotic index, and tumour necrosis (TN). Blood vessel invasion was detected by both factor VIII-related antigen and elastica van Gieson staining. To evaluate the best objective method to quantify microvessel density in angiogenesis, AMC was employed. The rate of AMC-high and BVI-positive tumours was 32.6 and 29.3%, respectively. That of both AMC-high and BVI-positive tumours was 10.1%. Univariate analysis showed that AMC/BVI, n, T, HG, LVI, p53, PCNA, MI, and TN were significantly predictive of RFS and OS. By multivariate analysis, AMC/BVI was the strongest independent prognostic factor for 20-year RFS (relative risk (RR)=5.5; P<0.0001) and for 20-year OS (RR=4.3; P<0.0001). Lymph-node status was still considered a powerful prognostic indicator; however, the combination of AMC and BVI provided more reliable prognostic information than lymph-node status for haematogenous dissemination.

Adolescent↗
PubMed2003

Inhibition of attachment of virions of Norwalk virus to mammalian cells by soluble histone molecules.

Viral infection is usually initiated by the binding of virus particles to specific receptor molecule(s) on the host cell surface. Blocking of this step prevents the following step, penetration into the cell. In the present study, we investigated the virus-cell interactions of virions of Norwalk virus (NV), a major etiological agent for viral diarrhea. We found that histone was an extremely strong NV-binding protein. Histone H1, a heterologous histone molecule, appeared to be able to interact not only with NV particles, but also with the cell surface. Histone H1 appeared capable of effectively preventing the attachment of NV to intestinal cells, but not of other viruses. No cytotoxic effects of histone were observed under the assay conditions. These results indicate that nonsecretory histone molecules may inhibit the attachment of viruses to cells like lactoferrins. Our results suggest that by searching virus-binding molecules, we might find antiviral agents, even for new viruses.

Animals↗
PubMed2003

Effects of cilostazol on serum lipid concentrations and plasma fatty acid composition in type 2 diabetic patients with peripheral vascular disease.

Cilostazol is an anti-thrombotic and vasodilating agent, reported to have both anti-thrombotic and cerebral vasodilating effects. We investigated the effects of cilostazol on serum lipid concentrations and plasma fatty acid composition in type 2 diabetic patients with peripheral vascular disease. The serum concentrations of total cholesterol, triglycerides, high-density lipoprotein-cholesterol, lipoprotein (a), remnant-like particles-cholesterol, apolipoproteins, and plasma fatty acid composition were measured in 17 diabetic patients with peripheral vascular disease before and 1, 3, and 6 months after administration of cilostazol (200 mg/day). Serum triglyceride concentrations were significantly decreased after cilostazol (from 1.31+/-0.17 mmol/l to 0.86+/-0.07 mmol/l at 6 months, P<0.01). Plasma docosahexaenoic acid levels were significantly increased after cilostazol (4.11+/-0.26% to 4.94+/-0.26% at 6 months, P<0.01). Our findings show that cilostazol can induce some beneficial changes in serum lipid profile and plasma fatty acid composition.

Aged↗
PubMed2003

Cardiac myxoma of the tricuspid valve in a dog.

A case of cardiac myxoma arising from the tricuspid valve is described in an 8-year-old dog that had suffered intermittent episodes of syncope. At surgical operation, a large, irregular, gelatinous mass was found attached to the septal leaflet of the tricuspid valve. The excised tumour, measuring 5x4x3.5 cm, had a grey-to-yellow, friable, mucoid, multilobulated and polypoid appearance, with focal haemorrhage. Histologically, the tumour consisted of a hypocellular mass of a myxoid matrix, rich in acid mucopolysaccharides, with a supporting structure of spindle-like, elongated or stellate cells scattered in an abundant stroma. The surface of the mass was covered by a single layer of endothelial-like cells. Immunohistochemistry revealed that the surface cells of the mass were positive for the endothelial marker CD34 and the constituent cells within the mass reacted positively and uniformly with antibodies to vimentin and alpha-smooth muscle actin. The dog died 36 h after the operation and, at necropsy, wide dissemination of myxomatous embolization to the intrapulmonary arteries was found.

Actins↗
PubMed2003

Simplified method for estimation of microbial activity in compost by ATP analysis.

A simplified method using ATP analysis was proposed to estimate the time course of microbial activity during composting. A compost sample was suspended in distilled water and its filtrate was used to estimate the ATP content in the compost by the luciferine-luciferase fluorescence reaction. The method permitted the rapid and simple determination of ATP in the compost and was successfully applied to monitor the time course of the microbial activity in the laboratory-scale composting process. The analytical simplicity in this method greatly improved the field-applicability of the ATP analysis for the composting process monitoring.

Adenosine Triphosphate↗
PubMed2003

Finite element analysis of the stresses around fixtures in various reconstructed mandibular models--part II (effect of horizontal load).

UNLABELLED: AIM OF EXPERIMENT: Having already studied the effect of vertical load (Nagasao et al., 2002), the purpose of this study was to investigate the effect of horizontal load on implants embedded into a virtually reconstructed mandible. MATERIAL AND METHODS: Three-dimensional virtual models of various reconstructed mandibles were designed on a PC and 50 N horizontal loads were applied on the cantilever portion of the upper structure. Then, using a finite element analysis, stresses occurring around the implants were calculated, and the directions of the forces that cause the maximum von Mises stresses were evaluated. Finally, the results were compared with those from vertical loading. RESULTS: In all models, the maximum stresses occurred around the implants embedded on the premolar region of the loaded side. In addition, the locations at which the maximum von Mises stresses occurred were greatly influenced by the structural character of the loaded side. CONCLUSION: When horizontal loads were applied to reconstructed mandibles, the location and direction of the maximum stresses around the dental implants appeared to be influenced much more by the structural characters of the reconstructed mandibles when compared with vertical loads.

Bone Transplantation↗
PubMed2003

Simultaneous stimulation of EP2 and EP4 is essential to the effect of prostaglandin E2 in chondrocyte differentiation.

OBJECTIVE: Prostaglandin E(2)(PGE(2)) has been reported to stimulate chondrocyte differentiation. However, the precise actions and signal transduction pathways of PGE(2)in cartilage are largely unknown. Our purpose is to identify which of the four PGE(2)receptor subtype(s), EP1-4, mediates the action of PGE(2)on chondrocyte differentiation. DESIGN: We used primary chondrocytes derived from the resting zone of rat rib cartilage. The effects on chondrocyte differentiation were assessed by measuring the Alcian blue-stainable proteoglycan content and the expression levels of type II collagen mRNA by Northern blot analysis. The expression of the four PGE(2)receptor subtypes in rat primary chondrocytes was examined by reverse transcription-polymerase chain reaction. RESULTS: PGE(2)stimulated the accumulation of proteoglycan and up-regulated the expression of type II collagen mRNA in primary chondrocytes. Dibutyryl cAMP, a cell-permeable analog of cAMP, an important intracellular mediator of PGE(2)signaling, also enhanced the expression of type II collagen mRNA and proteoglycan accumulation in chondrocytes. No EP agonist alone induced the expression of type II collagen mRNA. However, simultaneous administration of EP2 and EP4 agonists at high concentrations cooperatively induced the expression of type II collagen mRNA, mimicking the PGE(2)effect. The simultaneous stimulation of EP2 and EP4 also cooperatively enhanced proteoglycan accumulation and intracellular cAMP production. Moreover, an EP4 antagonist partially blocked the stimulatory actions of PGE(2)on the expression of type II collagen mRNA. CONCLUSION: These results suggest that simultaneous stimulation of EP2 and EP4 is necessary and sufficient to elicit the effect of PGE(2)on rat primary chondrocyte differentiation.

Animals↗
PubMed2003

Resting T cells negatively regulate osteoclast generation from peripheral blood monocytes.

There is accumulating evidence that T cells may be involved in osteoclastogenesis in a variety of murine systems. However, the precise role of human T cells in the regulation of osteoclast generation is still unclear. To address this issue, we investigated the effect of resting peripheral T cells on receptor activator of NF-kappaB ligand (RANKL)-induced osteoclast generation from human peripheral monocytes. Although osteoclasts were not generated in the culture of human peripheral blood mononuclear cells (PBMC) in the presence of RANKL and macrophage colony-stimulating factor (M-CSF), the addition of cyclosporine A (CsA), a potent inhibitor of T-cell function, resulted in the formation of an increasing number of lacunae resorption on dentine, suggesting T cells may inhibit osteoclast formation. In a coculture of T cells and monocytes, which were isolated from PBMC, T cells inhibited the osteoclast generation from monocytes, as determined by tartrate-resistant acid phosphatase (TRAP) staining and a pit assay using dentine. This inhibition of osteoclast generation by T cells was also observed in a culture of the parathyroid hormone-stimulated SaOS4/3 osteoblast cell line and monocytes. The culture in Transwell plates revealed that the cell-to-cell interaction was not required for the inhibition, suggesting that T-cell cytokines may be responsible for the inhibition. Among inhibitory T-cell cytokines on osteoclastogenesis, granulocyte-macrophage colony-stimulating factor (GM-CSF) and interferon-gamma (IFN-gamma) were actively produced by CD4 T cells but not CD8 T cells in the coculture of T cells with monocytes, and the neutralizing antibodies to these cytokines partially rescued the T-cell-induced inhibition of osteoclast formation. Although CsA did not affect RANKL-induced osteoclast generation in the culture of monocytes alone, it completely rescued the T-cell-induced inhibition of osteoclast formation and strongly inhibited the production of GM-CSF and IFN-gamma. Thus, we demonstrate that resting T cells negatively regulate the osteoclast generation via production of GM-CSF and IFN-gamma by CD4 T cells and that CsA stimulates the osteoclast generation through the inhibition of the production of these cytokines. These findings provide new insight into therapeutic strategies for immunosuppression-induced bone loss in transplant and other diseases.

Bone Remodeling↗
PubMed2003

Participation of endogenous IGF-I and TGF-beta 1 with enamel matrix derivative-stimulated cell growth in human periodontal ligament cells.

Previous studies have provided the biological basis for the therapeutic use of enamel matrix derivative (EMD) at sites of periodontal regeneration. A purpose of this study is to determine effects of EMD on cell growth, osteoblastic differentiation and insulin-like growth factor-I (IGF-I) and transforming growth factor-beta 1 (TGF-beta 1) production in human periodontal ligament cells (HPLC). We also examined participation of endogenous IGF-I and TGF-beta 1 with EMD-stimulated cell growth in these cells. HPLCs used in this study were treated with EMD alone or in combination with antihuman IGF-I antibody (anti-hIGF-I) or anti-hTGF-beta 1, recombinant human bone morphogenetic protein-2 (rhBMP-2), 1,25-dihydroxyvitamin D3[1,25(OH)2D3], rhTGF-beta 1 or rhIGF-I. After each treatment, cell growth, the production of IGF-I and TGF-beta 1 and the expression of osteoblastic phenotypes were evaluated. EMD stimulated cell growth in dose-dependent and time-dependent manners. EMD was also stimulated to express IGF-I and TGF-beta 1 at protein and mRNA levels. The EMD-stimulated cell growth was partially suppressed by cotreatment with anti-hIGF-I or anti-hTGF-beta 1, and cell growth was also stimulated by treatment with rhIGF-I or rhTGF-beta 1. rhBMP-2 stimulated alkaline phosphatase (ALPase) activity and ALPase mRNA expression, and 1,25(OH)2D3 stimulated ALPase and osteocalcin mRNA expression. However, EMD showed no effect on the osteoblastic phenotypes expression. These results demonstrated that EMD has no appreciable effect on osteoblastic differentiation, however it stimulates cell growth and IGF-I and TGF-beta 1 production in HPLC, and that these endogenous growth factors partially relate to the EMD-stimulated cell growth in HPLC.

Alkaline Phosphatase↗
PubMed2003

Adhesion molecule expression by bone marrow CD34-positive cells in aplastic anemia before and after immunosuppressive therapy.

Appropriate adhesion between bone marrow stem cells and the marrow microenvironment is necessary for hematopoiesis, since signals that promote maturation or apoptosis are transmitted from stromal cells to stem cells. In aplastic anemia (AA), interferon-gamma produced by stromal cells has more influence on the pathogenesis of marrow failure than interferon-gamma produced by lymphocytes. We evaluated the expression of cell adhesion molecules, such as very late antigen-4 (CD49d), and -5 (CD49e) or c-kit receptor (CD117), by CD34-positive bone marrow cells in patients with AA who achieved hematological complete remission after immunosuppressive therapy. Before treatment, CD34-positive cells showed markedly higher expression of CD49d and CD49e than cells from healthy controls, indicating the strong adhesion of stem cells to the bone marrow stroma. Expression of CD49d and CD49e was significantly decreased, reaching normal levels, after hematological recovery. These findings suggest that changes in adhesion molecule expression by stem cells are important in the pathology of AA.

Adult↗
PubMed2003

Effect of different proton pump inhibitors, differences in CYP2C19 genotype and antibiotic resistance on the eradication rate of Helicobacter pylori infection by a 1-week regimen of proton pump inhibitor, amoxicillin and clarithromycin.

AIM: To investigate the effect of different proton pump inhibitors, S-mephenytoin 4'-hydroxylase (CYP2C19) genotype and antibiotic susceptibility on the eradication rate of Helicobacter pylori. METHODS: One hundred and eighty-seven H. pylori-infected peptic ulcer patients were randomly treated with either rabeprazole (10 mg b.d.) or lansoprazole (30 mg b.d.) plus amoxicillin (750 mg b.d.) and clarithromycin (400 mg b.d.) for 1 week. The antibiotic susceptibility and CYP2C19 genotype (extensive or poor metabolizer) were investigated. RESULTS: The eradication rates in the rabeprazole-amoxicillin-clarithromycin (RAC) and lansoprazole-amoxicillin-clarithromycin (LAC) groups were 75% and 69%, respectively, on an intention-to-treat basis, and 80% and 75%, respectively, on a per protocol basis. The eradication rate for clarithromycin-resistant strains was significantly lower than that for clarithromycin-sensitive strains (24% vs. 86%, P < 0.05). For clarithromycin-sensitive strains in the LAC group, there was a tendency for a lower eradication rate in extensive than poor metabolizers. The eradication rate in extensive metabolizers in the RAC group tended to be higher than that in extensive metabolizers in the LAC group (89% vs. 78%, P = 0.079726). CONCLUSIONS: The success of the 1-week proton pump inhibitor-amoxicillin-clarithromycin regimen depends on the susceptibility of H. pylori to clarithromycin. Moreover, differences in CYP2C19 genotype influence the eradication rates of lansoprazole-based therapy, and the rabeprazole-based regimen has an advantage especially in extensive metabolizers.

2-Pyridinylmethylsulfinylbenzimidazoles↗