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Biomedical subjects

K Yoshida

Publications and source records attributed to K Yoshida.

At least 73 records · Page 4Linked to original sources
PubMed2005

The effects of ice application over the vastus medialis on the activity of quadriceps femoris assessed by muscle function magnetic resonance imaging.

AIM: The purpose of this study was to investigate the effect of ice application for the muscle vastus medialis (VM) on the activation pattern of the quadriceps femoris muscle during repetitive knee extensions using muscle function magnetic resonance imaging (mfMRI) technique. METHODS: Seven men underwent transverse relaxation time (T2)-weighted magnetic resonance imaging (spin echo, TR/TE=1500/25, 80 ms, 10 mm slice thickness and gap) of their right thigh at rest and immediately after isotonic knee extension exercise with 5 sets of 10 repetitions at a load equal to 70% of their 10 repetitions with and without skin cooling. Cooling over surface skin of the VM was carried out for 3 min before and during 60-s of each rest interval between the knee extension exercise. RESULTS: The relative change in T2 of the muscle vastus intermedius increased significantly more by skin cooling than the control (p<0.01), but not the muscle rectus femoris (RF), muscle vastus lateralis, and VM. CONCLUSION: These results suggest that selective skin cooling combined with repeated muscle contraction facilitates the activation of other synergistic muscles, making this technique useful for activating the agonist muscles expected for injured muscle in training and rehabilitation.

Adult↗
PubMed2004

Contribution of CD4+ and CD8+ T cells and interferon-gamma to the progress of chronic rejection of kidney allografts: the Th1 response mediates both acute and chronic rejection.

T cells mediating chronic rejection (CR) of human kidney allografts were characterized by comparing them with those mediating acute rejection (AR). Two lines of analysis were performed using biopsy specimens (23 CR and 8 AR). First, the extent of infiltration of CD4+ and CD8+ T cells into allografts was assessed from mRNA expression of CD4 and CD8. The group of CR specimens was not significantly different from the group of AR specimens in terms of the extent of CD4+ and CD8+ T cell infiltration, underlining the importance of the immunological contribution to the progress of CR. Second, Th1/Th2 polarization in infiltrating T cells was investigated by measuring mRNA expression of interferon gamma (IFN-gamma; a Th1 cytokine) and interleukin 4 (IL-4; a Th2 cytokine). IFN-gamma expression was detected in most CR specimens, and was not significantly different between the group of CR specimens and the group of AR specimens. On the other hand, IL-4 expression was detected in only two CR specimens and one AR specimen; from its pathological features, the AR in this last case was concomitant with CR. These results suggest that most cases of CR and of AR are mediated by Th1 mechanisms, although some cases of CR show features of both Th1 and Th2.

Acute Disease↗
PubMed2004

Nucleotide polymorphism in the Adh1 locus region of the wild rice Oryza rufipogon.

Nucleotide variation in the alcohol dehydrogenase (Adh1) locus region of the wild rice Oryza rufipogon and its related species was analysed to clarify the maintenance mechanism of DNA variation in Oryza species. The estimated nucleotide diversity in the Adh1 locus region of O. rufipogon was 0.002, which was one of the lowest values detected in nuclear loci of plant species investigated so far. Tests of neutrality detected significantly negative deviation from the neutral mutation model for the coding region, especially for replacement sites. When each of the ADH1 domains was considered, significance was detected only for the catalytic domain 1. These results suggest purifying selection in the Adh1 coding region. In the phylogenetic tree of Oryza species based on Adh1 variation, cultivated rice O. sativa subspp. japonica and indica were included in the cluster of O. rufipogon. The genetic distance of the Adh1 region between O. rufipogon and O. sativa was as low as the nucleotide diversity of O. rufipogon. These results imply that O. rufipogon and O. sativa cannot be classified based on the nucleotide variation of Adh1. No replacement divergence between O. rufipogon and the other three A-genome species (O. glumaepatula, O. barthii and O. meridionalis) were detected, indicating that ADH1 is conserved in the A-genome species. On the other hand, between O. rufipogon and the E-genome species O. australiensis, replacement changes were detected only in the catalytic domain 1. The difference in replacement substitutions between the A- and E-genome species may be related to adaptive changes in the ADH1 domains, reflecting environmental differences where the species encounter anaerobic stress.

Alcohol Dehydrogenase↗
PubMed2004

Multi-institutional phase II trial of irinotecan, cisplatin, and etoposide for sensitive relapsed small-cell lung cancer.

Irinotecan (CPT-11) has been shown to exhibit excellent antitumour activity against small-cell lung cancer (SCLC). A multi-institutional phase II study was therefore conducted to evaluate the efficacy and toxicity of CPT-11 combined with cisplatin (CDDP) and etoposide (ETOP) (PEI regimen) for the treatment of sensitive relapsed SCLC. Patients who responded to first-line chemotherapy but relapsed more than 8 weeks after the completion of first-line therapy (n=40) were treated using the PEI regimen, which consisted of CDDP (25 mg m(-2)) weekly for 9 weeks, ETOP (60 mg m(-2)) for 3 days on weeks 1, 3, 5, 7, and 9, and CPT-11 (90 mg m(-2)) on weeks 2, 4, 6, and 8 with granulocyte colony-stimulating factor support. Five complete responses and 26 partial responses were observed, and the overall response rate was 78% (95% confidence interval 61.5-89.2%). The median survival time was 11.8 months, and the estimated 1-year survival rate was 49%. Grade 3/4 leucocytopenia, neutropenia, and thrombocytopenia were observed in 55, 73, and 33% of the patients, respectively. Nonhaematological toxicities were mild and transient in all patients. In conclusion, the PEI regimen is considered to be highly active and well tolerated for the treatment of sensitive relapsed SCLC.

Adult↗
PubMed2004

Hypoxia-induced nitric oxide protects chondrocytes from damage by hydrogen peroxide.

OBJECTIVE: Because articular cartilage has no vascular supply, chondrocytes are hypoxic under normal physiological conditions. Nitric oxide (NO) plays an important role in chondrocyte damage, such as apoptosis. Although oxygen stress with hydrogen peroxide was found to cause chondrocyte damage, these data were obtained under normoxic (21% O2) conditions. We investigated the effects of hypoxia on hydrogen peroxide-induced chondrocyte damage METHODS: Bovine articular chondrocytes were used in this study. Proteoglycan (PG) synthesis and the induction of apoptosis were analyzed with [(35)S]-sulfate incorporation and annexin V staining, respectively. The induction of NO was examined using a fluorescent probe and RT-PCR. RESULTS: Cells maintained at 5% O2 had the maximum PG synthesis. Under normoxic conditions, hydrogen peroxide inhibited PG synthesis and induced annexin V positive cells in a dose-dependent fashion. However, in those cells cultured under hypoxic (5%) conditions, the hydrogen peroxide-induced annexin V expression was attenuated. Chondrocytes exposed to hypoxia showed induction of NO. When the hypoxia-induced NO was inhibited, the hypoxia-enhanced PG synthesis was abolished and hydrogen peroxide clearly induced cell damage. CONCLUSIONS: Endogenous NO induced by hypoxia protects chondrocytes from apoptosis induced by an oxidative stress.

Animals↗
PubMed2004

A new diagnostic test for VLCAD deficiency using immunohistochemistry.

BACKGROUND: Muscle pathology is often unhelpful in elucidating the specific underlying abnormality in patients with metabolic myopathy with rhabdomyolysis, including very-long chain acyl-CoA dehydrogenase (VLCAD) deficiency. Biochemical analyses require large amounts of biopsy samples for each enzyme assay. OBJECTIVE: To develop a more efficient diagnostic method for VLCAD deficiency. METHODS: The authors performed immunohistochemical analysis using an antibody to VLCAD on muscles from 344 patients (226 men and 118 women) without a specific diagnosis who had at least one of the following symptoms: myoglobinuria, high CK level, muscle pain, muscle stiffness, sudden infant death syndrome, and Reye-like syndrome. RESULTS: Immunoreactivity to VLCAD was absent or markedly reduced in 13 patients. Biochemical analyses confirmed that all these patients had low enzymatic activity and reduced amount of protein. They all had the myopathic phenotype. The authors identified homozygous or compound heterozygous mutations in all of them. All recombinant proteins had reduced enzymatic activity except for 128G>A (G43D) and 796C>G (P266A) mutants, indicating that they are neutral polymorphisms. CONCLUSIONS: The new screening method for the detection of VLCAD deficiency using an immunohistochemical technique identified 13 new Japanese patients with VLCAD deficiency.

Acyl-CoA Dehydrogenase, Long-Chain↗
PubMed2004

Enhancement of nitric oxide and proteoglycan synthesis due to cyclic tensile strain loaded on chondrocytes attached to fibronectin.

OBJECTIVE: Mechanical stress is an essential factor in the pathogenesis of osteoarthrosis. We sought to determine whether the strain-mediated alteration in proteoglycan (PG) synthesis was modulated by nitric oxide (NO) synthesis. METHODS: Cyclic tensile strain was applied to bovine articular chondrocytes. PG and NO synthesis were determined by [35S] sulfate incorporation and chemiluminescence analysis, respectively. To determine the expression of inducible NO synthase (iNOS), quantitative RT-PCR was used. RESULTS: Enhanced PG and NO synthesis were evident when cyclic tensile strain was applied to chondrocytes seeded on fibronectin-coated plates. When NO production was inhibited, PG synthesis was further enhanced. CONCLUSIONS: Cyclic tensile strain loaded on the chondrocytes enhanced NO synthesis and this enhanced NO inhibited PG synthesis.

Animals↗
PubMed2004

The emergence in Japan of Sathuperi virus, a tropical Simbu serogroup virus of the genus Orthobunyavirus.

In 1999, two viruses were isolated from blood samples of sentinel cattle in the Western part of Japan. The physiochemical and morphological properties of these viruses indicated that they belonged to the family Bunyaviridae. Sequence analysis of the S segment indicates that the two viruses are closely related to Sathuperi virus (SATV). The N-terminal 168 amino acid of the G2 protein of the M segment was highly homologous with that of SATV (98.2%). Given these results, we conclude that the newly isolated viruses are closest to SATV, which was initially isolated in India and Nigeria over 30 years ago.

Amino Acid Sequence↗
PubMed2004

Clonality analysis of T cells mediating acute and chronic rejection in kidney allografts.

The clonality of T-cell populations mediating acute and chronic rejection (AR and CR, respectively) of kidney allografts was ascertained by investigating the diversity of TCRBV genes expressed by allograft-infiltrating T cells. Both oligoclonality and polyclonality cases were found in biopsy specimens of AR as well as CR. These results indicated that the T-cell clonality in each specimen did not correlate directly with the mode of rejection. When AR and CR specimens were compared, however, the CR specimen group was significantly more polyclonal (or less oligoclonal) than the AR group. This result may reflect the higher chance of epitope spreading in the more slowly progressing CR than in AR.

Clone Cells↗
PubMed2004

Okadaic acid stimulates expression of Fas receptor and Fas ligand by activation of nuclear factor kappa-B in human oral squamous carcinoma cells.

In the present study, we used western blot and RT-PCR analysis to examine the expression of proteins and mRNAs of Fas receptor and Fas ligand in human oral squamous carcinoma SCC-25 cells treated with okadaic acid. Treatment with okadaic acid enhanced the expression of proteins and mRNAs of both Fas receptor and Fas ligand in SCC-25 cells. The amount of IkappaB-alpha in whole cell lysates decreased, while the level of NF-kappaB in nucleus increased, in the okadaic acid-treated cells. Okadaic acid-treatment also alters the cellular localization of NF-kappaB, from cytoplasm to nuclei. To investigate the activation of NF-kappaB in okadaic acid-treated SCC-25 cells, we performed electrophoretic mobility gel shift assay using nuclear extracts and the consensus oligonucleotide for NF-kappaB DNA binding site. The binding of nuclear proteins to the oligonucleotide of NF-kappaB increased when the cells had been treated with 20 nM okadaic acid for 4 h. We transfected the cells with pFLF1, which has the promoter region of Fas receptor gene containing NF-kappaB binding site. A luciferase reporter gene assay demonstrated that the activity in the cells transfected with pFLF1 and treated with 20 nM okadaic acid increased in a time-dependent manner and that the activity was more than three-fold over that in the control cells. Our results suggest that NF-kappaB activated at early stages in the okadaic acid-treated SCC-25 cells stimulated the promoter activity of Fas receptor in the cells leading to the apoptotic death of these cells.

Carcinoma, Squamous Cell↗
PubMed2004

Characterization of the 5' regulatory region of the mouse angiopoietin-like protein 4.

The 5' regulatory region of the mouse angiopoietin-like protein 4 (mANGPTL4), a remarkably versatile secreted protein responsible for hyperlipidaemia and angiogenesis, was cloned and functionally characterized. Three potential transcriptional start sites were determined by 5'-RACE and found to be at -129, -126 and -118, relative to the translation initiation codon. The activities of the putative promoters were confirmed using a firefly luciferase reporter gene assay system, following transient transfection into COS-1 cells. The PPAR alpha-regulated region and the minimal region required for basal activity of the mANGPTL4 promoter were determined by generating a series of deletion constructs, and were found to be encoded by a sequence between -2761 to -383 and -50 to -30, relative to the transcription start site. Putative recognition sequences for the transcription factor AP2 were identified in the minimal promoter sequences. These results are the first molecular characterization of the regulatory region of this important gene.

Angiopoietin-Like Protein 4↗
PubMed2004

Acute peripheral nerve recording characteristics of polymer-based longitudinal intrafascicular electrodes.

We examined the recording characteristics of two different types of polymer-based longitudinal intrafascicular electrodes (LIFEs) in peripheral nerve: single-stranded (s-polyLIFEs) and multistranded (m-polyLIFEs). Recordings were also made from Pt-Ir wire-based electrodes (PtIrLIFEs) as a control. The electrodes were implanted in either tibial or medial gastrocnemius branches of the rabbit sciatic nerve, and in the sciatic nerve of rats. Recorded neural activity induced by manually elicited afferent neural activity showed that both polyLIFE versions performed comparably to PtIrLIFEs.

Action Potentials↗
PubMed2004

Unresponsiveness to factor VIII inhibitor bypassing agents during haemostatic treatment for life-threatening massive bleeding in a patient with haemophilia A and a high responding inhibitor.

We report a case of haemophilia A with a high responding inhibitor of factor VIII (FVIII) who had a serious retroperitoneal haematoma caused by penetration of a duodenal ulcer. Inhibitor-bypassing therapy was commenced immediately on admission. On the 17th day of treatment with activated prothrombin complex concentrate (APCC; FEIBA, re-bleeding occurred and thrombelastography (TEG) demonstrated resistance to therapy. Treatment was changed to recombinant activated factor VII (rFVIIa; NovoSeven and resulted in clinical improvement together with an improvement in TEG parameters. On the 10th day of continuous infusion with NovoSeven, however, TEG again showed resistance to therapy. FEIBA infusions were re-introduced and TEG results remained satisfactory for 7 days. On day 34, however, further retroperitoneal bleeding was evident and a decline in the haemostatic efficiency of FEIBA was recorded by TEG. NovoSeven was again successfully administered for 7 days. There were no laboratory findings to indicate disseminated intravascular coagulation (DIC), hypercoagulability or abnormal fibrinolysis. The plasma-based clotting tests did not show any additional prolongation on the occasions when the TEG demonstrated unresponsiveness to FEIBA or NovoSeven. These findings suggested that some component of whole blood, other than plasma might have governed the TEG data. The long-term use of APCC such as FEIBA or rFVIIa, requires careful monitoring in terms of FVIII inhibitor bypassing activity as well as the tendency to DIC.

Adolescent↗
PubMed2004

Bonding between resin luting cement and glass infiltrated alumina-reinforced ceramics with silane coupling agent.

The purpose of this study was to evaluate the shear bond strengths of three dual-cured resin luting cements (Linkmax HV, Panavia Fluoro Cement, and RelyX ARC) to glass-infiltrated alumina-reinforced ceramic material and the effect of four silane coupling agents (Clearfil Porcelain Bond, GC Ceramic Primer, Porcelain LinerM, and Tokuso Ceramic Primer) on the bond strength. The two type-shaped of In-Ceram alumina ceramic glass-infiltrated specimens were untreated or treated with one of the four ceramic primers and then cemented together with one of the three dual-cured resin luting cements. Half of the specimens were stored in water at 37 degrees C for 24 h and the other half thermocycled 20,000 times before shear bond strength testing. Surface treatment by all silane coupling agents improved the shear bond strength compared with non-treatment. The specimens treated with Clearfil Porcelain Bond showed significantly greater shear bond strength than any of the other three silane coupling agents regardless of resin luting cements and thermocycling except for the use of Panavia Fluoro Cement at 20,000 thermocycles. When the alumina-reinforced ceramic material was treated with any silane coupling agent except GC Ceramic Primer and cemented with Linkmax HV, no significant differences in bond strength were noted between after water storage and after 20,000 thermocycles. After 20,000 thermocycles, all specimens except for the combined use of Clearfil Porcelain Bond or GC Ceramic Primer and Linkmax HV and GC Ceramic Primer and Panavia Fluoro Cement showed adhesive failures at the ceramic-resin luting cement interface.

Aluminum Oxide↗
PubMed2004

Activation of nuclear factor-kappa B in the conjunctiva with the epithelial scraping of the mouse cornea and human epidemic keratoconjunctivitis.

AIM: To examine the expression of p65, one of nuclear factor-kappa B (NF-kappa B), in the conjunctival epithelium of the C57Bl6 mouse and a patient with epidemic keratoconjunctivitis (EKC). METHODS: Normal and epithelial scraped cornea obtained 6 hours after the injury were processed for paraffin section. Samples of a normal and an EKC conjunctival epithelium were obtained using impression cytology. Both samples were analysed by immunocytochemistry using anti-p65 antibody. RESULTS: Immunocytochemistry with the anti-NF-kappa B p65 antibody revealed that p65 was localised in the cytoplasm of the conjunctival epithelium in the C57Bl6 mouse without the treatment. Six hours after the scraping of the cornea, p65 protein was expressed in the nuclei of the conjunctival epithelium. p65 was localised in the cytoplasm of the conjunctival epithelium in the human normal eye. p65 protein was expressed in the nuclei of the conjunctival epithelial cells in the EKC patient. CONCLUSION: These findings suggest that NF-kappa B was activated in the conjunctiva in the epithelial scraping of the mouse cornea and in human EKC.

Animals↗
PubMed2004

Sudden death of a patient with primary hypereosinophilia, colon tumours, and pulmonary emboli.

A 33 year old man was admitted to hospital six days after the onset of abdominal pain. There was hypereosinophilia, but the cause could not be identified (primary hypereosinophilia). The hypereosinophilia, high C reactive protein concentration, and gastrointestinal symptoms were alleviated by corticosteroid treatment. Unexpectedly, after this apparent recovery, he was found dead on the 27th day after admission. Necropsy disclosed two solid tumours primarily composed of eosinophils in the ascending and transverse colon. The cause of the sudden death was pulmonary artery emboli, derived from a thrombus in the left iliac vein.

Adult↗
PubMed2004

The perforin mediated apoptotic pathway in lung injury and fibrosis.

AIMS: The perforin mediated pathway is the major pathway of cytotoxicity induced by activated T cells and natural killer cells, and may be involved in the development of pulmonary fibrosis. METHODS: Perforin and granzyme B expression were examined in idiopathic pulmonary fibrosis by means of immunohistochemistry, and perforin knockout mice were used to examine whether or not perforin mediated cytotoxicity participates in the pathophysiology of bleomycin induced pneumopathy. RESULTS: Perforin and granzyme B expression were upregulated in infiltrating lymphocytes in lung tissue from patients with idiopathic pulmonary fibrosis compared with normal lung parenchyma. Perforin and granzyme B expression were upregulated predominantly in infiltrating mononuclear cells after bleomycin instillation in wild-type mice. Although the development of bleomycin induced pneumopathy was not completely prevented, the pathological grade of inflammation and fibrosis, and the number of apoptotic cells in lung tissue, were significantly decreased in perforin knockout mice compared with wild-type mice. CONCLUSIONS: These results suggest that perforin mediated apoptosis may be associated with the pathophysiology of lung injury and fibrosis.

Animals↗