Biomedical subjects

M Watanabe

Publications and source records attributed to M Watanabe.

At least 37 records · Page 2Linked to original sources

PubMed2006

Establishment of an animal model with side effects induced by mycophenolate mofetil and pharmacohistological analysis of them.

UNLABELLED: Mycophenolate mofetil (MMF) is used for immunosuppression after organ transplantation, but gastrointestinal side effects including diarrhea are sometimes observed with this drug. We sought to construct on animal model of diarrhea with MMF in rodents. MATERIALS AND METHODS: BALB/Cj mice, weighing 25 g received 500 mg /kg of MMF, 60 mg/kg of levofloxacin (LVFX), 1000 mg/kg of Hangeshashin-to (HST), which is traditional Kampo medicine. This cocktail was administered orally to MMF, LVFX, HST, MMF+LVFX, and MMF+LVFX+HST groups for 21 days. We measured the water content fecal collected on days 1, 4, 8, 11, 14, 18, and 21. Feces on day 21 were cultured for identification of fecal flora. Mice were sacrificed on day 21, with blood samples collected to measure mycophenolic acid (MPA) concentrations by HPLC. Jejunum, cecum, and colon were taken for histological evaluation. RESULTS: Significant weight loss of mice and increased fecal water content of were observed in MMF and MMF+LVFX but not in MMF+LVFX+HST groups. Serum MPA levels didn't differ in MMF-administered groups. Inflammatory changes in intestinal villi were observed in the cecum in MMF and MMF+LVFX groups. A change in fecal flora was observed in LVFX-administered groups. CONCLUSION: Diarrhea induced by MMF in a rodent model produced inflammatory changes in the cecum. LVFX seemed to change the activity of beta-glucuronidase in the fecal flora. HST suppressed fecal softening induced by MMF in this animal model.

Animals↗

PubMed2006

DHMEQ, a new NF-kappaB inhibitor, induces apoptosis and enhances fludarabine effects on chronic lymphocytic leukemia cells.

Chronic lymphocytic leukemia (CLL) is a low-grade lymphoid malignancy incurable with conventional modalities of chemotherapy. Strong and constitutive nuclear factor kappa B (NF-kappaB) activation is a characteristic of CLL cells. We examined the effects of a new NF-kappaB inhibitor, dehydroxymethylepoxyquinomicin (DHMEQ), on CLL cells. Dehydroxymethylepoxyquinomicin completely abrogated constitutive NF-kappaB activity and induced apoptosis of CLL cells. Apoptosis induced by DHMEQ was accompanied by downregulation of NF-kappaB-dependent antiapoptotic genes: c-IAP, Bfl-1, Bcl-X(L) and c-FLIP. Dehydroxymethylepoxyquinomicin also inhibited NF-kappaB induced by CD40 and enhanced fludarabine-mediated apoptosis of CLL cells. Results of this study suggest that inhibition of constitutive and inducible NF-kappaB by DHMEQ in combination with fludarabine is a promising strategy for the treatment of CLL.

Aged↗

PubMed2006

Multiple extradural arachnoid cysts at the spinal cord and cauda equina levels in the young.

STUDY DESIGN: A case report of multiple extradural arachnoid cysts at the spinal cord and cauda equina levels in the young. OBJECTIVE: To report an exceedingly rare case of multiple extradural arachnoid cysts at the spinal cord and cauda equina levels in the young. SETTING: Department of Orthopaedic Surgery, Tokai, Japan. CASE REPORT: An 11-year-old boy was diagnosed with multiple extradural arachnoid cysts at the spinal cord and cauda equina levels extending from the T5 to L5 vertebrae and surgery was performed. At 2 years after surgery, no recurrence was observed and muscle weakness of the lower extremities and sensory disturbance improved. CONCLUSION: Excision of only the arachnoid cysts at the spinal cord level led to a favorable outcome.

Arachnoid Cysts↗

PubMed2006

Restoration of transforming growth factor-beta type II receptor reduces tumorigenicity in the human adrenocortical carcinoma SW-13 cell line.

Transforming growth factor-beta (TGF-beta) is a potent growth suppressor. Acquisition of TGF-beta resistance has been reported in many tumors, and has been associated with reduced TGF-beta receptor expression. In this study, we examined TGF-beta 1, TGF-beta type I receptor (TbetaRI) and TGF-beta type II receptor (TbetaRII) expression in SW-13 adrenocortical carcinoma cells by Northern and Western blot analysis. SW-13 cells did not express TbetaRII mRNA or protein. We have investigated the role of TbetaRII in modulating tumorigenic potential using stably transfected SW-13 cells with TbetaRII expression plasmid. TbetaRII-positive SW-13 cell growth was inhibited by exogenous human TGF-beta1 (hTGF-beta1) in a dose-dependent manner. In contrast, SW-13 cells and control clones transfected with empty vector remained hTGF-beta1-insensitive. Xenograft examination in athymic nude mice demonstrated that TbetaRII-positive SW-13 cells reduced tumor-forming activity. Reconstructing the TbetaRII can lead to reversion of the malignant phenotype of TbetaRII-negative human adrenocortical carcinoma, which contains SW-13 cells. Reduced TbetaRII expression may play a critical role in determining the malignant phenotype of human adrenocortical carcinoma.

Adrenal Cortex Neoplasms↗

PubMed2006

Transient local overexpression of human vascular endothelial growth factor (VEGF) in mouse feto-maternal interface during mid-term pregnancy lowers systemic maternal blood pressure.

The effect on maternal circulation of transient human vascular endothelial growth factor (VEGF) (165) cDNA transfection into the mouse feto-maternal interface at day 14.5 post coitus (p.c.) using a hemagglutinating virus of Japan-envelope (HVJ-E) vector system is reported. On day 15.5 p.c., Western blotting clearly showed overexpression of 18 kD VEGF protein in the uterus. After VEGF transfection, the blood pressure was significantly lowered for 48 hours. On day 17.5 p.c., the blood pressure returned to the control level. Proteinuria was not observed after VEGF transfection. No preterm birth was observed during the course of pregnancy after the transfection procedure. After 24 hours of transfection, human VEGF was not detectable and the mouse VEGF level was similar to that in peripheral blood. However, the soluble fms-like tyrosine kinase (Flt)-1 concentration was significantly lower in VEGF-transfected mice. These results suggest that extraamniotic VEGF overexpression lowered the systemic blood pressure without altering the VEGF concentration in the peripheral blood. Local overexpression of VEGF may become a novel treatment for pregnancy-related disorders such as hypertension complicated-pregnancy and preeclampsia.

Animals↗

PubMed2006

The quantitative analysis of thin specimens: a review of progress from the Cliff-Lorimer to the new zeta-factor methods.

A new quantitative thin-film X-ray analysis procedure termed the zeta-factor method is proposed. This new zeta-factor method overcomes the two major limitations of the conventional Cliff-Lorimer method for quantification: (1) use of pure-element rather than multielement, thin-specimen standards and (2) built-in X-ray absorption correction with simultaneous thickness determination. Combined with a universal, standard, thin specimen, a series of zeta-factors covering a significant fraction of the periodic table can be estimated. This zeta-factor estimation can also provide information about both the detector efficiency and the microscope-detector interface system. Light-element analysis can also be performed more easily because of the built-in absorption correction. Additionally, the new zeta-factor method has several advantages over the Cliff-Lorimer ratio method because information on the specimen thickness at the individual analysis points is produced simultaneously with compositions, thus permitting concurrent determination of the spatial resolution and the analytical sensitivity. In this work, details of the zeta-factor method and how it improves on the Cliff-Lorimer approach are demonstrated, along with several applications.

Journal Article↗

PubMed2006

Functional properties and regional differences of human masseter motor units related to three-dimensional bite force.

The aim of this study was to estimate numerically the properties of masseter motor units (MUs) in relation to bite force magnitude and direction three-dimensionally and to confirm the hypothesis that the properties differ between different parts of the muscle by means of simultaneous recording of MU activity along with the MU location and three-dimensional (3D) bite force. The MU activity of the right masseter of four healthy men was recorded using a monopolar needle electrode in combination with a surface reference electrode. The location of the needle electrode was estimated stereotactically with the aid of magnetic resonance images and a reference plate. The magnitude and direction of the bite force was recorded with a custom-made 3D bite force transducer. The recorded bite force was displayed on a signal processor, which enabled the participant to adjust the direction and magnitude of the force. The activities of 65 masseter MUs were recorded. Each MU had specific ranges of bite force magnitude and direction (firing range: FR) and an optimum direction for recruitment (minimum firing threshold: MFT). There was a significant negative correlation between MFT and FR width. There were functional differences in MU properties between the superficial and deep masseter and between the superficial layer and deep layer in the superficial masseter. These results indicate that the contribution of human masseter motor units to bite force production is heterogeneous within the muscle.

Action Potentials↗

PubMed2006

Expressional screening of interferon-stimulated genes for antiviral activity against hepatitis C virus replication.

Type-I interferons (IFNs) and the interferon-stimulated genes (ISGs) play a major role in antivirus responses against hepatitis C virus (HCV) infection. In this study, we studied expression profiles of ISGs in cells supporting subgenomic HCV replication (Huh7/Rep), and screened their activities to suppress HCV replication. Real-time PCR analyses showed that the expression levels of 23 ISGs were significantly lower in Huh7/Rep than naive Huh7 cells due to transcriptional suppression of the interferon-stimulated response element (ISRE). Furthermore, the expression level of ISGs was also decreased in the cured Huh7 cells in which replicon had been eliminated (cHuh7), indicating adaptation of the cells to support HCV replication by downregulating ISGs. On the other hand, expression of HCV replicon was significantly suppressed by overexpression of several ISGs including PKR, MxA, IRF-9, GBP-1, IFI-6-16, IFI-27, 25OAS and IRF-1. Knock down of GBP-1, IFI-6-16 and IFI-27 by short hairpin RNA resulted in increase of HCV replication. Thus, we conclude that downregulation of ISG expression is required in the host cells supporting HCV replication and that several ISGs directly suppress HCV replication. The search for ISGs that regulate HCV replication may help to elucidate the cellular antiviral defence mechanisms against HCV infection.

Cell Line↗

PubMed2006

Site-specific mutation of the interferon sensitivity-determining region (ISDR) modulates hepatitis C virus replication.

The number of amino acid substitutions in the interferon sensitivity-determining region (ISDR) in the nonstructural 5A (NS5A) gene of hepatitis C virus (HCV) is closely associated with the interferon (IFN) response and viral load. Several HCV replicon-based studies have reported that ISDR sequences had an influence on viral replication in vitro. However, it is unclear as to how different ISDR sequences affect HCV replication. Various clinically observed ISDR sequences were introduced into HCV replicons and their contribution to viral replication was investigated using a colony formation assay and/or a transient replication assay. A mapping study of the ISDR was performed to identify the amino acid positions that critically affect replication. While no colonies were formed in the colony formation assay using HCV replicons with few mutations (0, 1 and 3) in the ISDR, numerous colonies (>200) appeared when using constructs with six mutations. Introduction of various distinct ISDR sequences with multiple mutations resulted in replication enhancement in transient assays. A mapping study identified several specific sites in the ISDR that critically affected replication, including codon 2209 which, in patients, was closely associated with a strong response to IFN. ISDR sequences associated with a clinical IFN response and viral load modulated the replication of HCV replicons, suggesting the importance of the ISDR sequence in HCV infection.

Amino Acid Sequence↗

PubMed2006

Antigen-presenting cells expressing glutamate decarboxylase 67 were identified as epithelial cells in glutamate decarboxylase 67-GFP knock-in mouse thymus.

Glutamate decarboxylase (GAD), which has two isoforms, GAD65, and GAD67, is responsible for synthesis of the major inhibitory neurotransmitter, gamma-aminobutyric acid. GAD is expressed predominantly in the central nervous system; recent reports suggest that GAD is also expressed in non-neuronal organs including the pancreas. In the pancreatic islets, GAD serves as one of the autoantigens in type I diabetes mellitus. Recent flow cytometric analyses have shown that a variety of self-antigens, including GAD, are ectopically transcribed and expressed in particular cell populations of the thymus, although consensus concerning the cellular phenotype has not been obtained. The aim of this study was to clarify the localization and cellular phenotype of GAD67-expressing cells in the thymus at a cellular level with a novel approach using GAD67-green fluorescent protein (GFP) knock-in mice, in which GFP is expressed specifically in GAD67-positive cells. GFP-positive cells were detected in the thymic medulla and were identified as epithelial cells by immunohistochemistry. Almost all GFP-positive cells were positive for major histocompatibility complex (MHC) class II antigen staining and were positive for both cytokeratin and Ulex Europaeus Agglutinin I, markers of medullary thymic epithelial cells, but were negative for CD11c, Gr-1, and CD45, markers of dendritic cells, macrophages, and B-lymphocytes, respectively.

Animals↗

PubMed2006

A local GABAergic system within rat trigeminal ganglion cells.

We investigated the GABAergic system within the Sprague-Dawley rat (2-3-weeks old) trigeminal ganglion (TG). Reverse transcription-polymerase chain reaction (RT-PCR) analysis revealed expression of glutamate decarboxylase (GAD) 65 and GAD67 mRNAs and mRNAs encoding GABA(A) receptor subunits alpha1-6, beta1-3, gamma1-3, and delta. In situ hybridization revealed that GAD65 and GAD67 mRNAs were expressed in neuronal cell bodies but not satellite cells. Immunohistochemical analysis showed that only GAD65 was expressed in all neuronal cell bodies, and approximately 70% of all neurons exhibited GABA immunoreactivity. Satellite cells were strongly immunopositive for GABA. GABA(A) receptor alpha1, alpha5, beta2/3 and gamma1/2/3 subunit immunoreactivities were observed in the majority of neurons, but no immunoreactivity for alpha2 was observed. Two types of cells were identified in TG based on cell size and morphology, type A and B. The percentage of cells expressing alpha3, alpha4, alpha6, and delta subunits appeared to be dependent on cell size, as delta and alpha6 expression were only observed in small (B-type) neurons. In whole-cell patch clamp experiments, GABA application induced inward Cl- currents in all neurons examined. The EC50 for GABA varied from 5.3 to 240 microm, and the Hill Coefficient (nH) varied between 0.98 and 2.6 at -60 mV. We found that GABA was released from TG cells by increasing extracellular K+ concentration to 100 mm. We speculate that GABA acts as a nonsynaptically released diffusible neurotransmitter, which may modulate somatic inhibition of neurons within the TG.

Animals↗

PubMed2006

Are comprehensive environmental changes as effective as health education for smoking cessation?

OBJECTIVES: To compare the effectiveness of health education on smoking cessation for all smokers regardless of their willingness to quit smoking and cumulative environmental changes including designation of smoking places, legislation, and price rise. DESIGN: Comparison of smoking cessation rates over two time periods: the period of health education on smoking cessation (1997-1999), and the period of cumulative environmental changes (2002-2004). SETTING: An occupational setting in a radiator manufacturing factory in Japan. SUBJECTS: All habitual male smokers who remained in the worksite through the pertinent time period (n = 202 in the period of health education and n = 170 in the period of environmental changes). MAIN OUTCOME MEASUREMENTS: Smoking cessation rates at the end of each time period. RESULTS: The smoking cessation rates over the periods of health education and environmental changes were 8.9% and 7.1%, respectively. There was no difference between these two proportions in a chi2 test (p = 0.513). The age adjustment did not significantly alter the cessation rate. CONCLUSIONS: Cumulative environmental changes are fairly effective in promoting smoking cessation, and may yield similar smoking cessation rates as a health education intervention reaching all smokers regardless of their willingness to quit smoking.

Adolescent↗

PubMed2006

Overall activity of all masticatory muscles during lateral excursion.

Quantification of the overall activity of every masticatory muscle is requisite for the analysis of stomatognathic function, which has not been accomplished by conventional electromyography. We used positron emission tomography and 18F-fluoro-deoxy-glucose to quantify the overall activity of every masticatory muscle during lateral excursion, and to evaluate the relative contribution of each masticatory muscle to lateral excursion. The present study suggested that lateral and medial pterygoid muscles are more responsible for lateral excursion than are masseter and temporal muscles. In particular, the contralateral lateral pterygoid muscle plays a major role, followed by the contralateral medial pterygoid muscle.

Adult↗

PubMed2006

Hypermethylation of CpGs in the promoter of the COL1A1 gene in the aged periodontal ligament.

Although the human periodontal ligament shows age-associated histological alterations, the molecular mechanisms are not yet understood. We previously found that COL1A1 gene expression declines with age. In this study, we asked whether DNA methylation in the regulatory region of the gene alters in the aging process, as a possible cause of the decline. The method used was a bisulfite modification of cytosine and nucleotide sequencing of DNA. While the 1st intron region was kept demethylated at young and old ages, the levels of methylation at most CpG sites in the proximal and distal regions of the promoter showed elevation at older ages. Analysis of the data indicates the possible importance of DNA hypermethylation in the promoter region for the age-associated decrease of COL1A1 gene expression.

Adolescent↗

PubMed2006

Dynamic compressive properties of the mandibular condylar cartilage.

The mandibular condylar cartilage plays an important role as a stress absorber during function. However, relatively little information is available on its dynamic properties under compression. We hypothesized that these properties are region-specific and depend on loading frequency. To characterize the viscoelastic properties of the condylar cartilage, we performed dynamic indentation tests over a wide range of loading frequencies. Ten porcine mandibular condyles were used; the articular surface was divided into 4 regions, anteromedial, anterolateral, posteromedial, and posterolateral. The dynamic complex, storage, and loss moduli increased with frequency, and these values were the highest in the anteromedial region. Loss tangent decreased with frequency from 0.68 to 0.17, but a regional difference was not found. The present results suggest that the dynamic compressive modulus is region-specific and is dependent on the loading frequency, which might have important implications for the transmission of load in the temporomandibular joint.

Animals↗

PubMed2006

Gamma-aminobutyric acid (GABA) and cell proliferation: focus on cancer cells.

In addition to its role in the adult mammalian nervous system as an inhibitory neurotransmitter, gamma-aminobutyric acid (GABA) is involved in the proliferation, differentiation, and migration of several kinds of cells including cancer cells. GABA is synthesized predominantly from glutamate by glutamate decarboxylase and exerts its effects via ionotropic GABA(A) receptors and/or metabotropic GABA(B) receptors. In this review, the current state of knowledge regarding the role of the GABAergic system in peripheral nonneuronal cell proliferation is described, and recent advances in elucidation of the mechanisms leading to cell proliferation are discussed.

Animals↗

PubMed2006

[Extensive educational program for high performance medical technologists].

The education system for medical technologists has recently been revolutionized, their educational periods vary from 2 to 9 years, and some already have doctoral degrees. In such a new situation, our faculty thinks that the most important point for new medical technologists is the ability to have a broad view of the clinical fields, especially the view of patients. Special training in bed-side education and a stint in several divisions, such as the surgical operation room, rehabilitation. radiological examination room, pharmacy, central storage room of medical records, and medical informatics, and so on, of the hospital is a powerful tool to obtain a broad view of the various clinical fields and can be essential for developing high performance medical technologists. As nine years have passed since starting this education, we evaluated this practice through systematic personal communication. As a result, it was found to be extremely effective for many reasons such as having a continuous image of the patient when they examine the blood sample in the hospital laboratory, showing advanced laboratory performance, and having no mental barrier to visiting the wards and so on. The abilities of our alumni are praised highly by many large scale hospitals around the country and 50% of them are working in the clinical laboratory division of these hospitals. About 40% are working in the division of research and development in various companies. We express sincere thanks to the director and all cooperative individuals for this course in the Osaka University Hospital.

Curriculum↗

PubMed2006

Clot removal therapy by aspiration and extraction for acute embolic carotid occlusion.

BACKGROUND AND PURPOSE: The purpose of our retrospective study was to investigate the feasibility, safety, and efficacy of clot removal therapy by aspiration and extraction for patients with acute stroke with embolic internal carotid artery (ICA) occlusion. METHODS: Of 814 consecutive patients with acute ischemic stroke admitted to our institution from March 2003 to April 2005, clot removal therapy was performed for 14. Inclusion criteria were patients (1) presenting within 6 hours of onset of cardioembolic stroke, (2) with serious neurologic symptoms defined by a National Institutes of Health Stroke Scale (NIHSS) score of at least 11, (3) without extensive high signal intensity on diffusion-weighted MR images but with decreased ipsilateral hemispheric cerebral blood flow on perfusion-weighted images (perfusion/diffusion mismatch), and (4) with total ICA occlusion on angiograms. We removed clots by aspiration and extraction with a microsnare through either a guiding or balloon guide catheter. Radiographic results, 7-day NIHSS, 3-month modified Rankin Scale, and procedure-related complications were evaluated. RESULTS: Of 10 patients treated with the balloon guide catheter to temporarily interrupt proximal flow, 7 obtained complete or partial recanalization. The 4 patients treated with the guiding catheter had no recanalization. Of the 7 patients with recanalization, 6 had favorable 7-day neurologic and 3-month functional outcome; all showed anatomic crossflow via the anterior communicating artery. A procedure-related complication, distal embolization into the ipsilateral anterior cerebral artery, occurred in 1 patient. CONCLUSION: Balloon guide catheter-assisted clot removal therapy for embolic ICA occlusion may provide a high recanalization rate and good clinical outcome in patients with anatomic crossflow.

Adult↗