Biomedical subjects

S Matsuda

Publications and source records attributed to S Matsuda.

At least 289 records · Page 16Linked to original sources

PubMed1997

[Comparative studies on activities of antimicrobial agents against causative organisms isolated from patients with urinary tract infections (1995). II. Background of patients].

Clinical background was investigated on patients with urinary tract infections (UTIs) from whom 785 bacterial strains were isolated in 11 hospitals during the period from June, 1995 through May, 1996. 1. Distributions of age and sex of patients and type of infections. Among the patients examined, those with ages 50 years or older were the most frequent (males: 80.5%, females: 69.7%), and, among females, those with ages in the 20's were 12.6%. With regard to types of infections, more than a half of infections among males were of complicated types, but most of infections among females were of uncomplicated types, especially among females of ages less than 60 years. 2. Ages of patients and types of pathogens. The higher the ages of patients, the lesser became the isolation frequencies of Proteus spp. and Serratia spp., but the higher were those of Klebsiella spp. and Pseudomonas spp. 3. Effect of antibiotic use on isolation frequencies of pathogens. Use of antibiotics decreased pathogens isolated from patients with uncomplicated UTIs drastically (237 isolates before antibiotics compared to 33 after). Even isolated pathogens from patients with complicated UTIs decreased drastically with the use of antibiotics when indwelling catheters were not in use (200 isolates before antibiotics compared to 83 after), but when indwelling catheters were in use, antibiotics apparently failed to decrease the isolation frequency. 4. Surgical procedures and types of causative organisms for UTIs. Escherichia coli was the most frequently isolated organism from uncomplicated cases of UTIs. From cases of complicated UTIs without indwelling catheters, Enterococcus faecalis was the most frequently isolated, followed by E. coli, P. aeruginosa and Klebsiella spp. When a surgical procedures were not done, E. coli was isolated most frequently. From cases of complicated UTIs with indwelling catheters, P. aeruginosa, E. faecalis and S. aureus were the organisms that were mainly isolated, with isolation frequencies of 23.9%, 17.3% and 12.7%, respectively. When no surgical procedures were used, isolation frequencies of P. aeruginosa, Klebsiella spp. and E. faecalis were 25.7%, 14.3% and 14.3%, respectively.

Adolescent↗

PubMed1996

Suppression of nerve growth factor-induced neuronal differentiation of PC12 cells. N-acetylcysteine uncouples the signal transduction from ras to the mitogen-activated protein kinase cascade.

The cellular redox state is thought to play an important role in a wide variety cellular signaling pathways. Here, we investigated the involvement of redox regulation in the nerve growth factor (NGF) signaling pathway and neuronal differentiation in PC12 cells. N-acetyl-L-cysteine (NAC), which acts as a reductant in cells both by its direct reducing activity and by increasing the synthesis of the cellular antioxidant glutathione, inhibited neuronal differentiation induced by NGF or by the expression of oncogenic ras in PC12 cells. NAC suppressed NGF-induced c-fos gene expression and AP-1 activation. These results suggest that neuronal differentiation and NGF signaling are subject to regulation by the cellular redox state. NAC also suppressed the NGF-induced activation of mitogen-activated protein kinases (MAPKs) and decreased the amount of tyrosine phosphorylation of MAPKs. The suppression of MAPK by NAC was independent of glutathione synthesis. In parallel with the suppression of MAPK, the activation of MAPK kinase kinase activity was also suppressed in the presence of NAC. In contrast, NGF-induced activation of Ras was not inhibited by NAC. The inhibitory effect of NAC on the MAPK cascade was independent of transcription and translation. Thus, NAC suppresses NGF-induced neuronal differentiation by uncoupling the signal transduction from Ras to the MAP kinase cascade in PC12 cells.

Acetylcysteine↗

PubMed1996

Ras-dependent and Ras-independent activation pathways for the stress-activated-protein-kinase cascade.

We have previously shown that osmotic stress activates both the mitogen-activated protein kinase (MAPK) cascade and the stress-activated protein kinase (SAPK, also known as JNK) cascade in rat fibroblastic 3Y1 cells and rat PC12 cells. Here, we show that treatment of these cells with sodium arsenite, a chemical compound that mimics the effects of heat shock, or anisomycin, a protein synthesis inhibitor, induces activation of SAPKs potently. These chemical compounds also stimulated the activity of SEK1/MKK4/JNKK, SAPK activator, and the activity of MEKK, SEK1 activator. Expression of a dominant negative mutant of Ras blocked the anisomycin-induced activation of SAPK and SEK1, but did not affect markedly the arsenite-induced or heat shock-induced activation in PC12 cells. The osmotic-stress-induced activation of SAPK was insensitive to the expression of a dominant negative Ras, but was partly sensitive to down-regulation of protein kinase C. These results suggest the existence of Ras-dependent and Ras-independent activation pathways for the SAPK cascade triggered by environmental stresses including chemical stress in PC12 cells. Cell staining with a specific anti-SAPK serum showed that SAPKs were present in both the cytoplasm and the nucleus under normal conditions, and became located mainly in the nucleus after osmotic stress or ultraviolet treatment, suggesting the nuclear translocation of SAPKs.

Animals↗

PubMed1996

[An analysis of the relationship among functional fitness tests, life style and bone density of the elderly in O town, Fukuoka Prefecture].

A functional fitness test, which is composed of four tests-standing up, walking, hand working, and rope working, was applied to thirty-four elderly women (62.9 +/- 5.2 y.o.) living in O town, Fukuoka Prefecture. The functional fitness level was lower among obese women, and higher among women who were doing more physical activities, as well as those who have more subjects of pleasure in their daily life. Furthermore, there was a positive correlation between the bone density and functional fitness level. The functional fitness test has several favorable characteristics for use in the community based health education for the elderly. For example, 1) it is very easy to conduct and does not require any special pre-test training, 2) it is very safe, 3) as results directly correspond to daily activities, it is rather easy to give concrete advise regarding health promotion in daily life.

Activities of Daily Living↗

PubMed1996

Photoreceptor protein s26, a cone homologue of S-modulin in frog retina.

A frog retinal protein named s26 is a 26-kDa protein found during purification of S-modulin in frog retina (Kawamura, S. (1992) Photochem. Photobiol. 56, 1173-1180). To identify its role in frog retina, first s26 was purified to nearly homogeneity with three chromatographical steps. Based on the partial amino acid sequences of the proteolysed fragments of s26, we isolated cDNAs that encode s26. The analysis of its amino acid sequence revealed that s26 is an S-modulin-like protein, while it shows higher homology to visinin. Visinin is a Ca2+-binding protein reported to be present in chicken cones, but its localization in the retina had been a subject in dispute. The present study showed that s26 is present in cone photoreceptors. The study also showed that s26 inhibits phosphorylation of rhodopsin after a light flash at high Ca2+ concentrations as S-modulin does. From these results, we concluded that s26 is a cone homologue of S-modulin. The result is consistent with the idea that each type of photoreceptors expresses each cell-type specific version of phototransduction proteins.

Amino Acid Sequence↗

PubMed1996

[Analysis of financial statements of Japanese private hospitals (1982-1991)].

In order to clarify the financial situation of Japanese private hospitals, the financial statements provided by the Social Welfare and Medical Service Corporation were analyzed for the period from 1982 to 1991. The results clarified the low growth rate and low profitability of the Japanese private hospitals, although their financial situation was relatively stable. However, the efficiency of cost has been stalled in recent years and profitability has been declining due to the low turnover rate of capital. According to the CVP analysis, the Profit volume ratio of the investigated hospitals has been increased to the level of 95%. This situation means that, in the current financial situation, more than half of the Japanese private hospitals will go into the red if revenue declines 5% due to some short term change in the managerial environment.

Cost-Benefit Analysis↗

PubMed1996

Characterization of DNA ligase from the fungus Coprinus cinereus.

DNA ligase was highly purified from the fungus Coprinus cinereus at the miotic recombination stage, pachytene. The pachytene DNA ligase showed three polypeptides with molecular masses of 88, 84 and 80 kDa, as estimated by the [32P]AMP-labeling assay. These three polypeptides were susceptible to reaction with an mAb against a 16-amino-acid sequence in human DNA ligase I, which is conserved in C-terminal regions of mammalian, vaccinia virus and yeast DNA ligases. Since rapidly purified preparations from fresh pachytene cells exhibited a single polypeptide of DNA ligase with a molecular mass of 88 kDa, the smaller polypeptides seemed to be limited-degradation products of the 88-kDa polypeptide during the isolation and purification procedures. K(m) values for ATP and (dT)20 hybridized with (dA)n were 1.5 microM and 90 nM, respectively. This enzyme was capable of joining (dT)20.(rA)n and (rA)12-18 (dT)n as well as (dT)20.(dA)n and able to ligate blunt-ended DNA in the presence of poly(ethylene glycol) 6000. DNA ligases were also partially purified from zygotene cells at the meiotic pairing stage and mitotic mycelium cells. In their molecular mass, immuno-reactivity, K(m) value and substrate specificity, they were indistinguishable from pachytene DNA ligase. These results suggest that the fungus C. cinereus at the pachytene stage contains DNA ligase with a molecular mass of 88 kDa as a main or a single species, which is quite similar to DNA ligases from the zygotene and mycelium cells in molecular and catalytic properties.

Amino Acid Sequence↗

PubMed1996

Ciliary neurotrophic factor attenuates spatial cognition impairment, cortical infarction and thalamic degeneration in spontaneously hypertensive rats with focal cerebral ischemia.

Ciliary neurotrophic factor (CNTF) has been shown to exhibit potent neurotrophic activity on peripheral and central neurons in vitro and in vivo. However, it remains to be determined whether or not CNTF rescues neuronal loss due to focal cerebral ischemia and prevents ischemia-induced disability of space navigation in rats. In the present in vivo study, we infused CNTF continuously for 4 weeks into the lateral ventricle, starting just after permanent occlusion of the left middle cerebral artery (MCA) of stroke-prone spontaneous hypertensive rats. CNTF infusion prevented the occurrence of ischemia-induced learning disability in a dose-dependent manner in rats subjected to the Morris water maze task. Subsequent histological examinations showed that cortical infarction and retrograde degeneration of the ipsilateral thalamic neurons in ischemic rats infused with CNTF were significantly less severe than those in ischemic rats infused with vehicle alone. These findings suggest that postischemic CNTF treatment prevents the occurrence of spatial learning disability in rats with permanent MCA occlusion, possibly by reducing neuronal damage within the cerebral cortex and secondary retrograde degeneration of the thalamus.

Analysis of Variance↗

PubMed1996

[An AHP analysis of knowledge and skills necessary to become an occupational physician and required under- and post-graduate education and training system].

In order to clarify the knowledge and skills necessary to become occupational physicians and the required under- and post-graduate education and training system, an AHP (Analytic Hierarchy Process) analysis was conducted in colloboration with 10 occupational physicians who had graduated from UOEH. After classifying the contents of their work and the necessary knowledge and skills necessary to fulfill their duties by the KJ method, the AHP technique was employed in order to determine the relative importance of 5 education and training courses: 'Under-graduate general education', 'Under-graduate medical education', 'The fundamental occupational health course', 'Post-graduate clinical residency', and 'On the job training'. Regarding knowledge and skills to fulfill the duties of an occupational physician, those of 'Social medicine', 'Information science' and 'Clinical medicine', in this order, were regarded as important. For the contents of an Occupational physician's work, 'Medical surveillance of workers' and 'Environmental management of workplaces' were evaluated as important. For the educational setting in order to master the necessary knowledge and skills, 'On the job training' was regarded as the most important, and then 'The fundamental occupational health course', and 'Post-graduate clinical residency' followed in this order.

Clinical Competence↗

PubMed1996

Physical and functional interactions of protein tyrosine kinases, p59fyn and ZAP-70, in T cell signaling.

The src family protein tyrosine kinases participate in signaling through cell surface receptors that lack intrinsic tyrosine kinase domains. One of the src family kinases, p59fyn (Fyn), plays an important role in the TCR-mediated signaling. Here we report that Fyn becomes associated with the zeta-associated tyrosine kinase, ZAP-70, in a T cell hybridoma upon stimulation. The association was transient; it occurred as early as 10 s after stimulation and disappeared after 10 min. The two proteins were also associated with each other when coexpressed in COS cells. Coexpression of the zeta-chain was not required for their interaction. Mutational analysis of Fyn and ZAP-70 revealed that their kinase activities were relevant to the association. Deletion of both the SH2 and SH3 domains of Fyn resulted in the decrease of the association with ZAP-70. Consistently, Fyn-SH2 and Fyn-SH3 fused to glutathione S-transferase were able to bind to ZAP-70. These data suggest that multiple sites of Fyn and ZAP-70 are involved in the association. Furthermore, coexpression of the wild-type of both kinases in COS cells enhanced tyrosine phosphorylation of the helix-turn-helix-containing protein, HS1. HS1 was also tyrosine phosphorylated upon TCR stimulation. Thus, we propose that Fyn phosphorylates and activates ZAP-70 and that both kinases cooperate in TCR signaling.

Amino Acid Sequence↗

PubMed1996

Tob, a novel protein that interacts with p185erbB2, is associated with anti-proliferative activity.

We have molecularly cloned a cDNA for a novel protein termed Tob (Transducer of ErbB-2) that interacts with the c-erbB-2 gene product p185erbB2. Nucleotide sequencing reveals that the Tob protein is a 45 kDa protein that does not contain either SH2 (Src Homology 2) or SH3 domain but is homologous to the previously characterized anti-proliferative gene product BTG-1 at its amino-terminal half. The carboxyl-terminal half of Tob is characterized by the presence of a sequence rich in proline and glutamine and shows no homology to known proteins. Like BTG-1, exogenously expressed Tob is able to suppress growth of NIH3T3 cells, but the growth suppression is hampered by the presence of kinase-active p185erbB2. By using the GST-Tob protein that contains either full length or amino-terminal half of Tob, we show that the carboxyl-terminal half of Tob is relevant to its interaction with p185erbB2. Furthermore, we could co-immunoprecipitate the Tob protein with anti-ErbB-2 antibody, and reciprocally the p185erbB2 with anti-Tob antibodies. These data suggest that p185erbB2 negatively regulates the Tob-mediated anti-proliferative pathway through its interaction with Tob, resulting possibly in growth stimulation by p185erbB2. Finally, expression of the Tob mRNA is observed in various cell types and is not correlated with expression of c-erbB-2, suggesting that other receptor-type protein-tyrosine kinases are also involved in the Tob-mediated regulation of cell growth.

3T3 Cells↗

PubMed1996

A membrane-associated GDP/GTP exchange protein specific for Rho small GTP-binding protein - partial purification and characterization from rat brain.

The Rho subfamily, consisting of three members (RhoA, -B and -C), belongs to the small GTP-binding protein superfamily. The Rho subfamily is implicated in regulation of various actin filament-dependent cell functions, such as cell aggregation, cell motility and cytokinesis. The Rho subfamily receives an upstream signal and is converted from the GDP-bound inactive form to the GTP-bound active form which transduces a signal to a downstream pathway. This conversion is regulated by GDP/GTP exchange proteins (GEPs) and several GEPs for the Rho subfamily have been identified. The GEPs thus far reported are mainly isolated from the cytosol fraction of various tissues and are not specific for the Rho subfamily. Here we have partially purified a membrane-associated GEP specific for the Rho subfamily (mRho GEP). mRho GEP was extracted from the crude synaptic membrane fraction of rat brain by a combination of detergent and NaCl, and partially purified by several column chromatographies. The partially purified mRho GEP was active on RhoA but was inactive on other small GTP-binding proteins including at least Rac1, Ki-Ras and Rab3A. RhoA undergoes post-translational lipid modifications and mRho GEP required these lipid modifications for its GEP activity. mRho GEP was not active in the presence of Rho GDI, an inhibitory Rho GEP. These results indicate that there is a membrane-associated GEP specific for Rho and suggest that Rho is activated by this GEP on the membranes.

Animals↗

PubMed1996

Interleukin-6 prevents ischemia-induced learning disability and neuronal and synaptic loss in gerbils.

Interleukin-6 (IL-6) has been shown to have potent neurotrophic activity on peripheral and central neurons in vitro. However, it remains to be determined whether or not IL-6 rescues hippocampal CA1 neurons from lethal ischemia and prevents ischemia-induced learning disability. In the present in vivo study, we infused IL-6 continuously for 7 days into the lateral ventricle of gerbil starting 2 h before 3-min forebrain ischemia. IL-6 infusion prevented the occurrence of ischemia-induced learning disability in a dose-dependent manner as revealed by a step-down passive avoidance task. Subsequent light and electron microscopic examinations showed that pyramidal neurons in the CA1 region of the hippocampus as well as synapses within the strata moleculare, radiatum and oriens of the region were significantly more numerous in gerbils infused with IL-6 than in those receiving vehicle infusion. These findings suggest that IL-6 has a trophic effect on ischemic hippocampal neurons.

Animals↗

PubMed1996

Origins of nitric oxide synthase-containing nerve fibers in the rat basilar artery with reference to the fine structure of the nerve fibers.

The origins of nitric oxide synthase (NOS)-containing nerve fibers in the rat basilar artery were studied by a combination of Fluoro-Gold retrograde tracing and immunohistochemistry. After application of Fluoro-Gold onto the middle part of the basilar artery, the dye accumulated in the sphenopalatine, otic, trigeminal, superior cervical, nodose ganglia and in the spinal ganglia at level C2 and C3. Nerve cells with NOS-like immunoreactivity were detected in the above ganglia, except for the superior cervical ganglion. Neurons that showed both NOS-like immunoreactivity and Fluoro-Gold fluorescence were numerous in the sphenopalatine and otic ganglia, and less numerous in the trigeminal, nodose and spinal ganglia. Under electron microscopy, a number of unmyelinated nerve terminals with neuronal NOS-like immunoreactivity was seen in proximity to smooth muscle cells in the tunica media of the basilar artery. These findings provide morphological evidence that NOS-containing nerve fibers in the rat basilar artery have multiple origins, and suggest that the control of posterior cerebral circulation by the parasympathetic and sensory ganglia are more complex than previously considered.

Animals↗

PubMed1996

Molecular cloning and characterization of Byp, a murine receptor-type tyrosine phosphatase similar to human DEP-1.

Novel murine cDNAs encoding a receptor-like protein tyrosine phosphatase, termed Byp (HPTP beta-like tyrosine phosphatase) were cloned. The putative Byp protein consists of 1238 amino acids, which possesses a single catalytic domain in the cytoplasmic region. The extracellular region comprises eight repeats of a fibronectin type III module and contains multiple N-glycosylation sites. The byp mRNA was 7.7-kb long and expressed in every tissue examined, its level being high in the brain and kidney. Transfection of the byp cDNA expression plasmid into COS7 cells resulted in the expression of a 220-kDa tyrosine phosphorylated protein. Furthermore, co-expression of Byp and the Src family kinase Fyn increased the level of tyrosine phosphorylation of Byp, suggesting that Byp was tyrosine-phosphorylated by Fyn. Finally, the byp gene was located to mouse chromosome 2E1-2 and rat chromosome 3q32-33.

3T3 Cells↗

PubMed1996

ErbB-2 expression is correlated with poor prognosis for patients with osteosarcoma.

BACKGROUND: It has been reported that the c-erbB-2 protooncogene is frequently amplified and overexpressed in many types of cancers, except sarcomas and hematological malignancies. METHODS: Expression of ErbB-2 in the tumors of 26 patients with conventional osteosarcoma was evaluated by immunoblotting. DNA from osteosarcoma tissues that expressed ErbB-2 were analyzed by Southern blot hybridization to examine gross rearrangement of the gene. The DNA was also surveyed for the presence of genetic mutation in the transmembrane domain of ErbB-2 by polymerase chain reaction-single-stranded DNA conformation polymorphism analysis. In addition, possible correlation of ErbB-2 expression with gender, age, histopathologic subtype, and response to chemotherapy was analyzed. Survival analysis was performed by the Kaplan-Meier test using the approximate chi-square statistic for the log-rank test. RESULTS: The ErbB-2 protein was detected in 11 of 26 osteosarcoma tissues (42%) by immunoblot analysis. Expression of ErbB-2 was confirmed by immunohistochemical studies using specific anti-ErbB-2 monoclonal antibody. However, neither amplification of the c-erbB-2 gene nor evidence of significant genetic mutation was found in these osteosarcomas. Expression of ErbB-2 examined by immunoblotting was most strongly correlated with early pulmonary metastases (P < 0.05). Among the entire group of 26 patients in this study, Kaplan-Meier life table survival of the patients with apparent ErbB-2 expression was significantly worse than that of the patients with little ErbB-2 expression (P < 0.01). CONCLUSIONS: In 42% of the osteosarcomas, the tumor cells expressed ErbB-2. Expression of ErbB-2 was strongly correlated with early pulmonary metastasis and poor survival rate for the patient. These data suggest that ErbB-2 plays a significant role in aggressive tumor growth and in the promotion of metastatic potential in osteosarcomas. ErbB-2 in the osteosarcoma tissues would be a useful prognostic marker for patients.

Adolescent↗

PubMed1996

Effects of GM-CSF and ordinary supplements on the ramification of microglia in culture: a morphometrical study.

Microglia transform from ameboid to ramified cells during development and display an ameboid appearance again under certain pathological conditions. Some cytokines produced by astrocytes may be responsible for the microglial transformation. In the present study, we compared the effects of cytokines, granulocyte/macrophage colony-stimulating factor (GM-CSF), macrophage colony-stimulating factor (M-CSF), and interleukin-3 (IL-3) on the morphology of rat cultured microglia. For quantitative evaluation, we employed "transformation index" as calculated by (perimeter of cell)2/4 pi (cell area). GM-CSF facilitated the ramification of cultured rat microglia, which was effectively induced in a serum-free medium. However, M-CSF and IL-3 did not induce the ramification. A certain serum adhesion protein (possibly vitronectin) as well as other high molecular weight substances in fetal calf serum inhibited the GM-CSF-induced microglial ramification. Among ordinary supplements for a chemically defined medium, progesterone, insulin, and a high concentration of glucose suppressed the ramification. These findings suggest that GM-CSF may be involved in microglial ramification and that many kinds of supplements that are added to culture media profoundly affect the morphology of microglial cells.

Animals↗

PubMed1996

Peroneal osteocutaneous flap raised on reconstructed popliteal artery for delayed union following open tibial fractures.

Two cases of delayed union following type IIIC open tibial fracture were treated by a pedicled peroneal osteocutaneous flap raised on reconstructed popliteal vessels. Dissection of the peroneal vessels from the already traumatized extremity was tedious, but this technique provided a reliable vascularized skin and bone graft that was indispensable for the fracture healing. Peroneal osteocutaneous flaps raised on the reconstructed popliteal artery have not been reported to date; they appear to be a good alternative to free osteocutaneous flaps for non-union of the proximal tibia.

Adult↗