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Biomedical subjects

T Nakano

Publications and source records attributed to T Nakano.

At least 289 records · Page 16Linked to original sources
PubMed2000

Multivariate analysis of prognostic determinants after surgery for renal cell carcinoma at Himeji National Hospital.

A clinico-pathological study was performed retrospectively on 62 patients who underwent surgery for renal cell carcinoma between January 1992 and October 1998 at Himeji National Hospital to clarify the prognostic determinants for survival. The median follow-up period was 32 months and the cause-specific survival rates at 1, 3 and 5 years were 86.7, 81.3, 81.3%, respectively. Of the 62 patients, 11 (17.7%) patients died of renal cell carcinoma and 2 (3.2%) patients died of unrelated causes. Of the variables related to survival, presenting symptoms, C-reactive protein (CRP), erythrocyte sedimentation rate (ESR), alkaline phosphatase (ALP), tumor size, pathological tumor grade, infiltration pattern, pathological tumor stage, N classification and M classification were significant risk factors for survival by univariate analysis. However, ALP, N classification and M classification were significant for survival as determined by the step-wise procedure and M classification was the most significant factor according to Cox's proportional hazard model analysis.

Adult↗
PubMed2000

Chronic graft-versus-host disease in children and adolescents after bone marrow transplantation from HLA-matched donors.

We analyzed 98 pediatric patients who underwent bone marrow transplantation (BMT) from serologically HLA-matched related donors (RD) or unrelated donors (UD) at our institute to clarify the actual status of chronic graft-versus-host disease (cGVHD). There were 36 evaluable cases of RD-BMT and 35 of UD-BMT. cGVHD was observed in 8 RD-BMT cases (22.2%) and in 23 UD-BMT cases (65.7%). In the RD-BMT cases, the limited and extensive types of cGVHD were observed in 4 cases each, whereas in the UD-BMT cases, the limited type was seen in 11 cases and the extensive type in 12. Prior acute GVHD was observed in 6 RD-BMT cases and in 18 UD-BMT cases. Two RD-BMT patients with extensive type cGVHD died of relapse and cytomegalovirus infection, and 4 UD-BMT patients died because of bronchiolitis obliterans, fungal infection, liver failure, and multiple organ failure, respectively. The incidence of cGVHD in these pediatric patients was as high as that in adult patients when UD-BMT was performed. Some UD-BMT patients required long-term immunosuppressive therapy after BMT. These findings suggest that cGVHD is a serious problem in pediatric UD-BMT. Therefore, intensive prophylaxis and treatment of GVHD must always be performed after UD-BMT.

Adolescent↗
PubMed2000

[Susceptibilities of bacteria isolated from patients with lower respiratory infectious diseases to antibiotics (1998)].

The bacteria isolated from the patients with lower respiratory tract infections were collected by institutions located throughout Japan, since 1981. Ikemoto et al. have been investigating susceptibilities of these isolates to various antibacterial agents and antibiotics, and analyzed some characteristics of the patients and isolates from them each year. Results obtained from these investigations are discussed. In these 18 institutions around the entire Japan, 532 strains of presumably etiological bacteria were isolated mainly from the sputa of 438 patients with lower respiratory tract infections during the period from October in 1998 to September in 1999. MICs of various antibacterial agents and antibiotics were determined against 85 strains of Staphylococcus aureus, 100 strains of Streptococcus pneumoniae, 96 strains of Haemophilus influenzae, 75 strains of Pseudomonas aeruginosa (non-mucoid strains), 6 strains of Pseudomonas aeruginosa (mucoid strains), 38 strains of Moraxella subgenus Branhamella catarrhalis, 26 strains of Klebsiella pneumoniae etc., and the susceptibilities of 517 strains were assessed except for those strains that died during transportation. S. aureus strains for which MICs of oxacillin (MPIPC) were higher than 4 micrograms/ml (methicillin-resistant S. aureus: MRSA) accounted for 60.0%. Vancomycin (VCM) and arbekacin (ABK) showed the most potent activities against MRSA. But one of MRSA showed resistance to ABK with the MIC of 64 micrograms/ml. The sensitive strains of MRSA to VCM have decreased. The frequency of penicillin (PC)-intermediate S. pneumoniae (PISP) + PC-resistant S. pneumoniae (PRSP) have increased in 46.0% for 1998 comparatively from 30.9% of 1997's. But PRSP decreased, and PISP increased into 39.0% of 1998 years from 19.8% of 1997's. Panipenem (PAPM), imipenem (IPM) and faropenem (FRPM) showed the most potent activities against S. pneumoniae with MIC80s of 0.125 microgram/ml or below. Against H. influenzae and M. (B.) catarrhalis, almost all the drugs showed good activities. The sensitive strains of them against ceftazidime (CAZ) decreased in 1997, but those have increased in 1998. Inversely, the susceptibility of them against cefotiam (CTM) had been higher in 1997, but those have been lower in 1998. Tobramycin (TOB) showed the most potent activity against P. aeruginosa (both mucoid and nonmucoid strains). All drugs except ampicillin (ABPC) were active against K. pneumoniae. A quite few of K. pneumoniae showed low susceptibilities. Also, we investigated year to year changes in the characteristics of patients, their respiratory infectious diseases, and the etiology. The examination of age distribution indicated that the proportion of patients with ages over 70 years was 48.6% of all the patients showing a slight increase in every year. About the proportion of diagnosed diseases as follows: Bacterial pneumonia was the most frequent with 40.2%. The ratio of it has increased slightly, and the increased rate was 10% in patients with ages over 70 years compared with the results in 1997. Chronic bronchitis have decreased slightly with 27.6% in 1998. Number of strains isolated from patients before administration of antibiotics were more than those after administration of them in chronic bronchitis, but these were almost same number in bacterial pneumonia. Administration of antibiotics has changed the results of the frequency of isolation of bacterial species. Bacterial isolations before administration of antibiotics were as follows: S. pneumoniae 26.7%, H. influenzae 23.8%, S. aureus 13.3% and M. (B.) catarrhalis 10.8%. The frequencies of S. aureus decreased after antibiotics administration over 15 days, but the frequencies of P. aeruginosa (both mucoid and non-mucoid) was not affected. The frequencies of P. aeruginosa was 45.5% after administration over 15 days. The frequencies of S. pneumoniae decreased upon administration of antibiotics, these were only 4.5% over 15 days. The frequencies of H. (

Anti-Bacterial Agents↗
PubMed2000

Effects of intra-aortic ballon pumping on renal sympathetic nerve activity and renal circulation in dogs.

BACKGROUND: Little is known on how intra-aortic balloon pumping (IABP) affects neural circulatory regulation, even though many studies have been done to clarify the effects of IABP on hemodynamics. Although IABP is used clinically in patients with severe heart failure, whose sympathetic nerve activity is increased, there are no previous reports that demonstrate the effects of IABP on neural regulation in heart failure. The aim of this study is to determine the effects of IABP on neural regulation of renal circulation with both normal and failing heart condition in dogs. METHODS: We directly measured renal sympathetic nerve activity and hemodynamic parameters (heart rate, central venous pressure, distal aortic pressure, proximal aortic pressure, left ventricular pressure, renal sympathetic nerve activity, ascending aortic flow, and renal arterial flow) before and during IABP driving in both normal and failing heart condition in dogs (n=7). Acute heart failure models were made by coronary ligation. RESULTS: IABP driving inhibits renal sympathetic nerve activity and improves renal circulation in failing heart condition, while these phenomena do not occur in normal heart condition. CONCLUSIONS: These findings suggest that IABP may show its full effect on renal circulation via neural regulation especially in failing heart condition.

Animals↗
PubMed2000

[The status of NIHS Information and Computing Infrastructure (NICI)].

From 1999 to 2000, NIHS Information and Computing Infrastructure (NICI) were newly renovated. The purposes of the renovation are (1) the improvement of the communication for business works in NIHS, (2) supporting for the research, (3) supporting for the administration work. The Internet connection speed was upgraded from 256 Kbps to 1.5 Mbps. The high quality network sever machines and database server machines were installed. The large-scale software systems were renewed their versions. Four experimental stations for medical plants at Hokkaido, Izu, Wakayama and Tanegashima connected to NIHS at Tokyo or Osaka branch by ISDN. We describe the providing information on NIHS home page, and how to utilize NICI for our research and official works.

Databases, Factual↗
PubMed2000

[Development of research support environment for molecular pharmacology and toxicology].

The Chem-Bio Informatics division has developed the institute-wide computer network which is connected to the Internet via IMnet (Inter Ministry Network) sponsored by the Government. We call the network and associated information and computing infrastructure as NICI, the NIHS Information and Computing Infrastructure. The primary goal of NICI is to provide general communication environment such as e-mails, and the second goal is to provide WWW environment. Accomplishing these two goals the division is now challenging to develop information and computing environment that directly supports pharmaceutical and toxicological research. The prototype of this environment which consists of various chemical and biomolecular databases and computing tools has been developed under the name of MOBI-DICS. The concept and vision on how to extend the prototype to institute-wide infrastructure was discussed.

Computational Biology↗
PubMed2000

Enzymic chemical reaction under microgravity environment in space.

In recent years, some papers have reported synergism in the biological effects of space radiation and microgravity. However, there is no direct evidence for these phenomena. As one possible mechanism, we investigated whether DNA ligation in the final step of DSBs repair of DNA molecules induced by radiation is depressed by microgravity. Therefore, we have scheduled the space experiments of the effects of microgravity on repair activity of T4 DNA ligase for DSBs prepared with digestion of a restriction enzyme (Sma I) to plasmid DNA. As another possible mechanism, the high mutation frequency may be induced from abnormal base-incorporation during DNA replication under microgravity. Using the Taq polymerase and polymerase III, we have also scheduled whether mutation frequency is affected by microgravity during DNA replication for a damaged DNA base induced by an alkylating agent (N-methyl-N-nitrosourea, MNU).

Cosmic Radiation↗
PubMed1999

Inhibitory phosphorylation site for Rho-associated kinase on smooth muscle myosin phosphatase.

It is clear from several studies that myosin phosphatase (MP) can be inhibited via a pathway that involves RhoA. However, the mechanism of inhibition is not established. These studies were carried out to test the hypothesis that Rho-kinase (Rho-associated kinase) via phosphorylation of the myosin phosphatase target subunit 1 (MYPT1) inhibited MP activity and to identify relevant sites of phosphorylation. Phosphorylation by Rho-kinase inhibited MP activity and this reflected a decrease in V(max). Activity of MP with different substrates also was inhibited by phosphorylation. Two major sites of phosphorylation on MYPT1 were Thr(695) and Thr(850). Various point mutations were designed for these phosphorylation sites. Following thiophosphorylation by Rho-kinase and assays of phosphatase activity it was determined that Thr(695) was responsible for inhibition. A site- and phosphorylation-specific antibody was developed for the sequence flanking Thr(695) and this recognized only phosphorylated Thr(695) in both native and recombinant MYPT1. Using this antibody it was shown that stimulation of serum-starved Swiss 3T3 cells by lysophosphatidic acid, thought to activate RhoA pathways, induced an increase in Thr(695) phosphorylation on MYPT1 and this effect was blocked by a Rho-kinase inhibitor, Y-27632. In summary, these results offer strong support for a physiological role of Rho-kinase in regulation of MP activity.

3T3 Cells↗
PubMed1999

Application of real-time radiation dosimetry using a new silicon LET sensor.

A new type of real-time radiation monitoring device, RRMD-III, consisting of three double-sided silicon strip detectors (DSSDs), has been developed and tested on-board the Space Shuttle mission STS-84. The test succeeded in measuring the linear energy transfer (LET) distribution over the range of 0.2 keV/micrometer to 600 keV/micrometer for 178 h. The Shuttle cruised at an altitude of 300 to 400 km and an inclination angle of 51.6 degrees for 221.3 h, which is equivalent to the International Space Station orbit. The LET distribution obtained for particles was investigated by separating it into galactic cosmic ray (GCR) particles and trapped particles in the South Atlantic Anomaly (SAA) region. The result shows that the contribution in dose-equivalent due to GCR particles is almost equal to that from trapped particles. The total absorbed dose rate during the mission was 0.611 mGy/day; the effective quality factor, 1.64; and the dose equivalent rate, 0.998 mSv/day. The average absorbed dose rates are 0.158 mGy/min for GCR particles and 3.67 mGy/min for trapped particles. The effective quality factors are 2.48 for GCR particles and 1.19 for trapped particles. The absorbed doses obtained by the RRMD-III and a conventional method using TLD (Mg(2)SiO(4)), which was placed around the RRMD-III were compared. It was found that the TLDs showed a lower efficiency, just 58% of absorbed dose registered by the RRMD-III.

Calibration↗
PubMed1999

On the Cusp around Central Black Holes in Luminous Elliptical Galaxies.

In this Letter, we show that a massive black hole (MBH) that falls into the center of a galaxy on the dynamical timescale leaves a weak cusp (rho~r-1&solm0;2) around it, which is in good agreement with the recent observations of luminous elliptical galaxies by the Hubble Space Telescope. Such an event is a natural outcome of the merging of two galaxies that have central MBHs. This is the only known mechanism for forming weak cusps in luminous elliptical galaxies. Therefore, the existence of the weak cusps indicates that the central black holes of luminous elliptical galaxies have fallen to the center from outside, most likely during a major merger event.

Journal Article↗
PubMed1999

Different roles of glycosylphosphatidylinositol in various hematopoietic cells as revealed by a mouse model of paroxysmal nocturnal hemoglobinuria.

Patients with paroxysmal nocturnal hemoglobinuria (PNH) have one or a few clones of mutant hematopoietic stem cells defective in glycosylphosphatidylinositol (GPI) synthesis as a result of somatic mutation in the X-linked gene PIG-A. The mutant stem cell clone dominates hematopoiesis by a mechanism that is unclear. To test whether a lack of multiple GPI-anchored proteins results in dysregulation and expansion of stem cells, we generated mice in which GPI-anchor negative cells are present only in the hematopoietic system. We transplanted lethally irradiated mice with female fetal liver cells bearing one allele of the Piga gene disrupted by conditional gene targeting. Because of the X-chromosome inactivation, a significant fraction of the hematopoietic stem cells in fetal livers was GPI-anchor negative. In the transplanted mice, cells of all hematopoietic lineages contained GPI-anchor negative cells. The percentage of GPI-anchor negative cells was much higher in T lymphocytes including immature thymocytes than in other cell types, suggesting a regulatory role for GPI-anchored proteins at an early stage of T-lymphocyte development. However, the proportions of GPI-anchor negative cells in various blood cell lineages were stable over a period of 42 weeks, indicating that Piga mutation alone does not account for the dominance of the mutant stem cells and that other phenotypic changes are involved in pathogenesis of PNH.

Animals↗
PubMed1999

A product of growth arrest-specific gene 6 modulates scavenger receptor expression in human vascular smooth muscle cells.

Although Gas6 is identified as a growth factor for vascular smooth muscle cells (VSMCs), its roles in these cells have not been clearly elucidated. To examine the role of Gas6 in atherosclerosis, we examined the effects of Gas6 on scavenger receptor family expression in VSMCs. Scavenger receptor class A, one of the scavenger receptor family members, was upregulated in VSMCs by Gas6. Furthermore, the atherogenic lipoprotein, oxidized LDL, induced Gas6 production in these cells. These results indicate that Gas6 plays an important role in foam cell formation in human VSMCs.

Cell Line↗
PubMed1999

Isoforms of the small non-catalytic subunit of smooth muscle myosin light chain phosphatase.

Chicken gizzard smooth muscle myosin light chain phosphatase is composed of a approximately 37 kDa catalytic subunit, a approximately 110 kDa myosin binding or targeting subunit and a approximately 20 kDa subunit (MPs) whose function is as yet undefined. It was reported previously that a cloned chicken gizzard MPs cDNA encodes a protein of 186 amino acids (aa) [Y.H. Chen, M.X. Chen, D.R. Alessi, D.G. Gampbell, C. Shanahan, P. Cohen, P.T.W. Cohen, FEBS Lett. 356 (1994) 51-55]. More recently, we obtained by PCR amplification another MPs cDNA that encodes a protein of only 161 aa [Y. Zhang, K. Mabuchi, T. Tao, Biochim. Biophys. Acta 1343 (1997) 51-58]. In this work we obtained cDNAs corresponding to both sequences using a different set of PCR primers, indicating that the two sequences correspond to isoforms that most likely arose from alternative splicing of the same gene. Using two polyclonal antibodies, one raised against the recombinant 161 aa isoform of chicken gizzard MPs and the other against a C-terminal polypeptide that is present only in the 186 aa isoform, we found that while the 161 aa isoform is the predominant one in chicken gizzard, in chicken aorta it is the 186 aa one; in chicken stomach both isoforms are present, and in mammalian tissues such as ferret and rat only the 186 aa isoform is detected. Furthermore, we purified the MPs associated with the chicken gizzard myosin light chain phosphatase holoenzyme and determined its molecular weight, amino acid composition and six residues of its C-terminal sequence. The results from these analyses showed conclusively that the predominant isoform in chicken gizzard is the 161 aa one.

Amino Acid Sequence↗
PubMed1999

Measurement of the directional distribution of incident particles in the Shuttle-Mir mission orbit.

The measurement of the directional distribution of incident particles was made by using the Real time Radiation Monitoring Device (RRMD)-III placed inside the Space Shuttle STS-84 cruised at an altitude of 400 km and an inclination angle of 51.6 degrees, which are the same as the cruising orbit of the International Space Station (ISS). The directional distributions of incident particles were evaluated over the observed linear energy transfer (LET) range (1-100 keV/micrometers). The pitch angle distribution is also obtained using the geomagnetic model of IGRF-95. The result is roughly in good agreement with the distribution obtained by the VF1-MIN anisotropy model calculation within the present experimental errors, if the shielding distribution is assumed to be uniform.

Anisotropy↗
PubMed1999

Receptor-mediated modulation of murine mast cell function by alpha-melanocyte stimulating hormone.

The proopiomelanocortin (POMC)-derived neuropeptide alpha-melanocyte stimulating hormone (alpha-MSH) is known to modulate some aspects of inflammation through direct effects on T cells, B cells, and monocytes. To determine whether alpha-MSH might similarly influence mast cell responsiveness, mast cells were examined to see if they expressed the receptor for alpha-MSH, melanocortin-1 (MC-1), and whether alpha-MSH altered mast cell function. We thus first identified MC-1 on bone marrow cultured murine mast cells (BMCMC) and a murine mast cell line (MCP-5) employing flow cytometry and through detection of specific binding. Subsequent treatment of mast cells with alpha-MSH increased the cAMP concentration in a characteristic biphasic pattern, demonstrating that alpha-MSH could affect intracellular processes. We next examined the effect of alpha-MSH on mediator release and cytokine expression. IgE/DNP-human serum albumin-stimulated histamine release from mast cells was inhibited by approximately 60% in the presence of alpha-MSH. Although activation of BMCMC induced the expression of mRNAs for the inflammatory cytokines IL-1beta, IL-4, IL-6, TNF-alpha, and the chemokine lymphotactin, mRNAs for IL-1beta, TNF-alpha, and lymphotactin were down-modulated in the presence of alpha-MSH. Finally, IL-3-dependent proliferative activity of BMCMC was slightly but significantly augmented by alpha-MSH. Taken together, these observations suggest that alpha-MSH may exert an inhibitory effect on the mast cell-dependent component of a specific inflammatory response.

Animals↗
PubMed1999

[Clinical usefulness of half-dose gadolinium-enhanced MR angiography of portal venous system (MR portography)--combined use with conventional dynamic MR imaging].

The clinical usefulness of half-dose Gadolinium-enhanced MR portography combined with the conventional full-dose dynamic MR imaging was evaluated on normal volunteers and patients. Half-dose MR portography was performed immediately following conventional full-dose Gd-enhanced dynamic MR imaging. The visualization of the extrahepatic portal system was either good or excellent in most cases excluding the splenic vein which was poor in 20.7%. That of the right and left main portal branches was also excellent. As for segmental branches, the visualization was poor of the left lobe. The comparison with digital subtraction angiography showed that the visualization of the right and left main portal branches was mostly equal. That of the splenic vein alone was worse on MR portography. We conclude that half-dose Gadolinium-enhanced MR portography is useful for the overall assessment of the portal venous system and can be added to the conventional dynamic MR imaging.

Adult↗