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M Nakahara

Publications and source records attributed to M Nakahara.

At least 37 records · Page 2Linked to original sources
PubMed2001

Standardization of laboratory data and establishment of reference intervals in the Fukuoka Prefecture: a Japanese perspective.

Standardization of 22 clinical chemistry analytes and five serum protein constituents has been performed in the Fukuoka Prefecture, which has a population of approximately five million. The standardization project was established to determine reference intervals for these analytes by educating physicians, medical technologists and staff of medical institutions, and by daily or monthly monitoring the use of common control samples through e-mail. Standardization extended to 97% of the institutions in the prefecture. Results for 14 of the 22 clinical chemistry analytes have become highly reliable and differences between institutions decreased. Standardization of other analytes is now in progress. Regional collaboration based on international guidelines led to a significant improvement in interlaboratory comparability. Areas where further improvements are needed have been identified.

Adolescent↗
PubMed2001

Proinflammatory cytokines regulate the gene expression of hyaluronic acid synthetase in cultured rabbit synovial membrane cells.

To elucidate the mechanism of accumulation and fragmentation of hyaluronic acid (HA) under inflammatory conditions, we investigated the effect of proinflammatory cytokines on hyaluronic acid synthetase (HAS) mRNA expression using cultured rabbit synovial membrane cells. HASs mRNA levels were determined by real-time PCR. HAS2 mRNA expression was maximally enhanced 3.3- and 2.8-fold after 3-hour stimulation with IL-1beta (1 ng/ml) and after 1-hour stimulation with TNF-alpha (10 ng/ml). HAS3 mRNA expression was increased by a maximum of 4.3 times after 3-hour stimulation with IL-1beta (10 ng/ml), whereas 1-hour stimulation with TNF-alpha (10 ng/ml) and IFN-gamma (10 ng/ml) induced around a 2.5-fold increase in HAS3 mRNA. Although IFN-gamma (1-100 ng/ml) alone showed little effect on HAS2 mRNA expression, the effect was synergized by combined with both IL-1beta and TNF-alpha, substantially increasing HAS2 mRNA expression. These results suggest that proinflammatory cytokines regulate the HAS expression, and consequently may contribute to the accumulation and fragmentation of HA.

Animals↗
PubMed2001

[Clinical laboratory data and reference intervals standardized in Fukuoka].

In Fukuoka whose population is approximately five million inhabitants, surveys on the accuracy of laboratory data have been performed by the Fukuoka Prefecture Medical Association for the last 30 years. We have been attempting to evaluate the data for routine use since 1988, and it has become possible to share laboratory data between all institutions in Fukuoka prefectures. As a result, reference intervals for 23 clinical chemistry analytes were established in 1995, to which were added in 1996 five serum protein constituents that have been utilized for clinical examinations. Methods for documentations and monitorings the data obtained in the prefecture were also established, standardization of the above analytes extended to 97% of the institutions in the prefecture. Results for 14 of the 23 clinical chemistry analytes have become highly reliable and clinically useful as differences between institutions in terms of results have narrowed. Standardization of other analytes is now in progress.

Aged↗
PubMed2000

Molecular evidence for the early evolution of photosynthesis.

The origin and evolution of photosynthesis have long remained enigmatic due to a lack of sequence information of photosynthesis genes across the entire photosynthetic domain. To probe early evolutionary history of photosynthesis, we obtained new sequence information of a number of photosynthesis genes from the green sulfur bacterium Chlorobium tepidum and the green nonsulfur bacterium Chloroflexus aurantiacus. A total of 31 open reading frames that encode enzymes involved in bacteriochlorophyll/porphyrin biosynthesis, carotenoid biosynthesis, and photosynthetic electron transfer were identified in about 100 kilobase pairs of genomic sequence. Phylogenetic analyses of multiple magnesium-tetrapyrrole biosynthesis genes using a combination of distance, maximum parsimony, and maximum likelihood methods indicate that heliobacteria are closest to the last common ancestor of all oxygenic photosynthetic lineages and that green sulfur bacteria and green nonsulfur bacteria are each other's closest relatives. Parsimony and distance analyses further identify purple bacteria as the earliest emerging photosynthetic lineage. These results challenge previous conclusions based on 16S ribosomal RNA and Hsp60/Hsp70 analyses that green nonsulfur bacteria or heliobacteria are the earliest phototrophs. The overall consensus of our phylogenetic analysis, that bacteriochlorophyll biosynthesis evolved before chlorophyll biosynthesis, also argues against the long-held Granick hypothesis.

Bacteria↗
PubMed2000

Mutations of the bak gene in human gastric and colorectal cancers.

The Bcl-2 homologue Bak is a potent inducer of apoptosis. We performed PCR-based single-strand conformational polymorphism and sequencing analysis of the entire coding region of the bak gene (exons 2-6) in 24 primary gastric cancers (6 early-stage and 18 advanced-stage cancers) and 20 primary colorectal cancers (6 early-stage and 14 advanced-stage cancers). The data herein demonstrate, for the first time, the mutation of the bak gene in gastric and colorectal cancers. Missense bak gene mutations were observed in 3 of 24 (12.5%) gastric cancers and 2 of 20 (10.0%) colorectal cancers. Sequence alterations without amino acid alteration were observed 1 of 24 (4.2%) gastric cancers and 2 of 20 (10.0%) colorectal cancers. Mutations in the bak gene were observed only in advanced-stage gastrointestinal cancers but not in early-stage cancers. Our observations suggest that mutations in this gene predispose bearers to the development of gastrointestinal malignancies in at least a subset of the cases.

Colorectal Neoplasms↗
PubMed2000

Endoscopic resection of a pelvic neurogenic tumor through the retroperitoneal approach.

A pelvic neurogenic tumor resected endoscopically through the retroperitoneal approach is described. Close examination of a 62-year-old man who complained of dull pain in the lower abdomen revealed a tumor on the posterior surface of the iliacus muscle. The tumor was extracted endoscopically without the need for a laparotomy. This procedure involves a less invasive approach that may be useful for benign retroperitoneal pelvic tumors.

Endoscopy↗
PubMed2000

Identification of a marine benthic P(3HB)-degrading bacterium isolate and characterization of its P(3HB) depolymerase.

A poly[(R)-3-hydroxybutyrate] (P(3HB))-degrading marine bacterium (strain NK-1, JCM10458) was isolated from the Pacific Ocean deep-sea floor (1165 m in depth) in Japan. The organism was a motile and Gram negative, aerobic, and rod-shaped bacterium, and its DNA had a guanine-plus-cytosine content of 57.7 mol%. On the basis of several phenotypic characters and a phylogenetic analysis of the gene coding for 16S rRNA, this strain was identified as Marinobacter sp. The strain required sodium salt for growth in the medium and secreted a P(3HB) depolymerase into the supernatant when it was cultivated on (S)-3-hydroxybutyric acid or P(3HB) as the sole carbon source. The P(3HB) depolymerase (PhaZMsp) was purified to homogeneity from the culture supernatant of Marinobacter sp. by hydrophobic and ion exchange column chromatography and showed a molecular mass of 70 kDa. PhaZMsp was stable at temperatures below 37 degrees C and at pH values of 7.5-10.0. The N-terminal amino acid sequences of both the purified enzyme and the truncated one shared high homologies to the N-terminal and internal sequences of Pseudomonas stutzeri depolymerase, respectively. High-performance liquid chromatography analysis revealed that the enzymatic products of P(3HB) yielded monomer, dimer, and trimer of 3-hydroxybutyric acid. PhaZMsp was capable of hydrolyzing P(3HB), poly(3-hydroxypropionate), and poly(4-hydroxybutyrate).

Amino Acid Sequence↗
PubMed2000

Involvement of nitric oxide in UVB-induced pigmentation in guinea pig skin.

Ultraviolet (UV) B irradiation evokes erythema and delayed pigmentation in skin, where a variety of toxic and modulating events are known to be involved. Nitric oxide (NO) is generated from L-arginine by NO synthases (NOS). Production of NO is enhanced in response to UVB-stimulation and has an important role in the development of erythema. NO has recently been demonstrated as a melanogen which stimulates melanocytes in vitro, however, no known in vivo data has been reported to support this finding. In this study, we investigated the contribution of NO with UV-induced pigmentation in an animal model using an NOS inhibitor. UVB-induced erythema in guinea pig skin was reduced when an NOS inhibitor, L-NAME (N-nitro-L-arginine methylester hydrochloride), was topically applied to the skin daily, beginning 3 days before UVB-irradiation. Delayed pigmentation and an increased number of DOPA-positive melanocytes in the skin were markedly suppressed by sequential daily treatment with L-NAME. Furthermore, melanin content 13 days after UVB-irradiation was significantly lower in skin treated with L-NAME than in the controls. In contrast, D-NAME (N-nitro-D-arginine methylester hydrochloride), an ineffective isomer of L-NAME, demonstrated no effect on these UV-induced skin responses. These results suggest that NO production may contribute to the regulation of UVB-induced pigmentation.

Animals↗
PubMed2000

Expression of the insulin-like growth factor system and cancer progression in hormone-treated prostate cancer patients.

BACKGROUND: The insulin-like growth factor (IGF) system, which is composed of two ligands (IGF-I and IGF-II), two receptors (IGFR-I and IGFR-II) and six binding proteins (IGFBP-1 to -6), plays an important role in cell biology. To identify the main components in the IGF system that contribute to human prostate cancer progression after hormone therapy, mRNA expression of the IGF system in human prostate cancer tissue was systematically examined. METHODS: Expression of the IGF system in 24 carcinomas obtained from total prostatectomies after hormone therapy was examined. Expression levels of mRNA of each component of the IGF system were analyzed by quantitative reverse transcription-polymerase chain reaction procedures and compared with clinicopathologic parameters. RESULTS: Expression of the IGF system, except IGFBP-1, was detected in all prostate cancer tissue samples. The expression of IGF-II and IGFBP-2 significantly correlated with pathologic stage, lymph node metastasis, histologic differentiation and serum prostate-specific antigen (PSA) levels after hormone therapy. However, expression of IGF-I was significantly lower in locally advanced prostate cancer tissue than in tissue from the early stage. Expression of IGFBP-5 was significantly related to only serum PSA levels after hormone therapy. CONCLUSIONS: In the IGF system, IGF-II and IGFBP-2 play a role in human prostate cancer progression and their increased expression is a possible candidate for a prognostic indicator in hormone-treated prostate cancer patients.

Aged↗
PubMed2000

The status of Fas and Fas ligand expression can predict recurrence of hepatocellular carcinoma.

The status of Fas and Fas ligand (Fas L) expression was investigated in this study for 103 hepatocellular carcinomas (HCC). We studied the expression of the following three factors, Fas and Fas L expression in carcinoma cells and Fas L expression in stromal mononuclear cells (defined as stromal Fas L index). Fas expression in HCC cells was significantly decreased in cases with poor differentiation (P < 0.0001) and of larger size (P = 0.0058). Fas L expression in carcinoma cells was observed exclusively in moderately or poorly differentiated cases. Furthermore, each factor had prognostic significance for disease-free survival (DFS) (P< 0.0001, P = 0.0222 and 0.0027 respectively). We then scored the results of each factor and defined the total score as 'Fas-Fas L risk score'. The P-value of the score for DFS was even lower than that of the clinical stage by multivariate analysis. These results suggest that the evaluation of Fas and Fas ligand expression potentially has a significant prognostic value for DFS of HCC patients, in addition to the clinical stage, and can be regarded as a new prognostic marker.

Aged↗
PubMed2000

Crystallization and preliminary X-ray diffraction studies of cytochrome c6 from Porphyra yezoensis.

Cytochrome c(6) from the red alga Porphyra yezoensis has been purified and crystallized by the sitting-drop vapour-diffusion method. Two different crystal forms, tetragonal and orthorhombic, were obtained. The tetragonal crystals belong to space group P4(1)2(1)2 or P4(3)2(1)2, with unit-cell dimensions a = 49.33 (2), c = 83.70 (10) A. The orthorhombic crystals belong to space group P2(1)2(1)2(1), with unit-cell dimensions a = 46.74 (2), b = 49.42 (1), c = 37.11 (1) A. Absorption spectra of the crystals showed that the tetragonal form was oxidized and the orthorhombic form was reduced.

Crystallization↗
PubMed2000

An increased number of CD40-high monocytes in patients with Crohn's disease.

OBJECTIVE: CD40-CD40 ligand (CD40L) interaction is essential for the T-lymphocyte-dependent immune response. This interaction may be operational in the pathogenesis of inflammatory bowel diseases (IBD). The present study examined the expression of CD40 in peripheral blood mononuclear cells (PBMNCs) and tissue specimens, and CD40-stimulated interleukin (IL)-12 release from PBMNCs in IBD. METHODS: The expression of CD40 in PBMNCs and tissue inflammatory cells was examined by flowcytometry and immunohistochemistry, respectively. IL-12 release was measured in cultured media of PBMNCs by an enzyme-linked immunosorbent assay. RESULTS: Most peripheral blood B-lymphocytes expressed CD40 in all subjects. However, in ulcerative colitis (UC) patients, a significantly increased mean fluorescence intensity (MFI) of CD40 on B-lymphocytes was detected, compared with control subjects and patients with Crohn's disease (CD). In contrast, both the percentage positivity and MFI of CD40 on monocytes of active CD subjects were significantly increased, compared with the other groups. In active CD patients, a high level of IL-12 release from PBMNCs was observed by CD40 stimulation, compared with those of the other groups. When primed with IFN-gamma, PBMNCs from inactive CD patients released a significantly high level of IL-12, probably via stimulation by the CD40 monoclonal antibody. In the affected mucosa of CD, numerous CD40-positive cells were demonstrated, and they were also CD68-positive, suggesting these double CD40/ CD68-positive cells are tissue macrophages. CONCLUSIONS: These results suggest that the examination of CD40 expression in PBMNCs might enable the differentiation of CD from UC. CD40-high monocytes in CD patients may play a role in the pathogenesis of CD.

Adolescent↗
PubMed2000

A case of congenital afibrinogenemia: fibrinogen Hakata, a novel nonsense mutation of the fibrinogen gamma-chain gene.

Congenital afibrinogenemia due to a novel homozygous nonsense mutation of the fibrinogen gamma-chain gene, fibrinogen Hakata, was found in an 18-year-old Japanese girl who had received supplemental fibrinogen therapy since she was 4 months old. The plasma fibrinogen concentrations of the proband were measured as less than 10 mg/dl by a functional method and less than 17 mg/dl by an immunological method. Fibrinogen concentrations of her family were in the range of 94-164 mg/dl. The proband and her family had no other clinical symptoms. Genomic DNA of the proband and her family was isolated from leukocytes, and all exons of fibrinogen subunits and their intron/exon boundaries were analyzed. A genetic mutation, a guanine-to-thymine (G-to-T) transversion at the nucleotide position of 5860, was identified on exon 7 of the gamma-chain gene. This mutation changed the codon for the 231st residue of the gamma-chain from GAG (Glu) to TAG (stop). No other mutation was observed. Aalpha, Bbeta and gamma chains were observed in plasma of the heterozygous family members. However, only a trace amount of Aalpha chain and no gamma chain was detected in the plasma of the proband.

Afibrinogenemia↗
PubMed2000

[A case report of unresectable colon cancer that disappeared following pharmacokinetic modulation chemotherapy (PMC)].

We encountered a case of unresectable colon cancer that disappeared following pharmacokinetic modulating chemotherapy (PMC). A 41-year-old male underwent ileotransverse anastomosis following a diagnosis of ileus due to unresectable colon cancer with peritoneal dissemination and multiple liver metastases. He was treated weekly with an intravenous infusion of 5-FU, 1,000 mg/body/24 hours and an oral administration of UFT 400 mg/day (PMC). After 6 months of weekly treatment of PMC, colon tumor disappeared and metastatic liver tumors decreased in size. PMC can be administered to outpatients without serious side effects; thus, this therapy improves the prognosis and the patient's quality of life.

Administration, Oral↗
PubMed1999

Effect of amino acid substitution in amphiphilic alpha-helical peptides on peptide-phospholipid membrane interaction.

It was previously found that a cationic amphiphilic peptide, Ac-(Leu-Ala-Arg-Leu)3-NHCH3 (4(3)), caused the destabilization of a phospholipid membrane and showed strong antibacterial activity [Lee et al. Biochim. Biophys. Acta 1986; 862: 211-219]. In order to investigate the effect of changing alpha-helix propensity, hydrophobicity and basicity in 4(3) on the peptide conformation and activity, the 4(3) analogs, [Gly (or Val)6]4(3), [Gly (or Val)2,6]4(3), [Gly (or Val)2,6,10]4(3), [Gln3]4(3), [Gln3,7]4(3) and [Gln3,7,11]4(3) were synthesized. Except for [Val2,6]4(3) and [Val2,6,10]4(3), which mainly formed a beta-structure, other peptides formed an alpha-helix and showed moderate membrane-perturbing activity toward neutral and acidic lipid vesicles. All the peptides other than [Val2,6,10]4(3) and [Gln3,7,10]4(3) had the antibacterial activity comparable with that of 4(3). The relationship between the membrane-perturbing activity and the antibacterial activity was not always parallel. Conclusively, the Ala-->Val substitution in 4(3) causes the change of peptide conformation and the presence of a cationic amino acid residue is necessary for the antibacterial activity.

Amino Acid Sequence↗
PubMed1999

Expression and prognostic roles of the G1-S modulators in hepatocellular carcinoma: p27 independently predicts the recurrence.

Expression of cell-cycle modulators at the G1-S boundary, retinoblastoma gene product (pRb), p21, p16, p27, p53, cyclin D1, and cyclin E was investigated with 104 hepatocellular carcinomas (HCC), as well as 90 of their adjacent noncancerous lesions and 9 normal liver control specimens. The labeling indices (LI) of pRb, p21, p16, and p27 were higher in HCC lesions than in the adjacent noncancerous lesions and normal controls. Especially, p27 LI in noncancerous lesions was significantly higher than that in normal livers (P =.011). Aberrant p53 expression and cyclin D1 and E overexpression were observed exclusively in HCC lesions. pRb was positive in 85.6% of the HCC cases and was not related to any clinicopathological parameters. The p21 LI was generally low (average, 5.5 +/- 9.8). Although a negative regulator, p21 LI was higher in cases with intrahepatic metastasis (P =.0359). The p16 LI was significantly decreased (P =.0121) in cases with advanced stage. p27 LI was significantly decreased in cases with portal invasion (P =.0409), poor differentiation (P <.0001), larger size (P =.0421), and intrahepatic metastasis (P =.0878, borderline significance). On the other hand, aberrant p53 expression showed positive relationships with poor differentiation (P =.0004) and Ki-67 LI (P =. 0047). Cyclin D1 overexpression was found in 32.6% of the cases and occurred more frequently in those with high Ki-67 LI (P =.0032), pRb expression (P =.0202), poor differentiation (P =.0612, borderline significance), and intrahepatic metastasis (P =.0675, borderline significance). Cyclin E was overexpressed in 35.5% and had positive relationships with Ki-67 LI (P =.0269) and stage (P =.0125). In univariate analysis, cases with p27 LI < 50 (P =.0004), cyclin D1 overexpression (P =.0041), and cyclin E overexpression (P =.0572, borderline significance) showed poorer outcomes for disease-free survival (DFS). In multivariate analysis, p27 expression could be recognized as an independent prognostic marker for DFS. These findings suggest that in HCC: 1) p27 is active against HCC progression in early phases and, possibly, hepatocarcinogenesis as a negative regulator and can be a novel prognostic marker for DFS; and 2) cyclin D1 predominantly works for cell-cycle progression at the G1-S boundary.

Adult↗
PubMed1999

Biliary bacterial infection decreased the secretion of bile acids and bilirubin into bile.

BACKGROUND: Bacterial cholangitis is frequently associated with serious complications. METHODS: The plasma disappearance rates and the biliary output of bile acids and bilirubin after percutaneous transhepatic biliary drainage (PTBD) were examined in 29 patients with extrahepatic biliary obstruction. RESULTS: Twenty-nine patients were divided into the bacteria-minus (n = 17) and bacteria-plus (n = 12) groups. Decreases in the plasma bile acid and bilirubin levels of the bacteria-minus group (t1/2 = 0.38 and 3.8 days for bile acids and bilirubin, respectively) were faster than those of the bacteria-plus group (t1/2 = 1.7 and 7.5 days). The bile flow rate was significantly increased in the bacteria-plus group compared with the bacteria-minus group. The calculated values of bilirubin and bile acid in the bile were higher in the bacteria-minus group than in the bacteria-plus group. CONCLUSIONS: Bacterial colonization in the bile stimulates bile duct cells to increase bile volume and inhibits the hepatocyte transport activity of bile acids and bilirubin.

Aged↗