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H Nishihara

Publications and source records attributed to H Nishihara.

At least 19 recordsLinked to original sources
PubMed2002

Quantitative and rapid detection of the trichloroethylene-degrading bacterium Methylocystis sp. M in groundwater by real-time PCR.

We developed a method based on real-time PCR for the specific and rapid enumeration of a trichloroethylene-degrading methanotroph, Methylocystis sp. M, with the aim of monitoring the strain in groundwater. A primer set designed from the nucleotide sequence of the mmoC gene of a soluble methane monooxygenase (sMMO) gene cluster from Methylocystis sp. M was specific to amplify the DNA region from the strain and no PCR products were amplified with the sMMO gene clusters from six other methanotroph strains. The real-time PCR reliably quantified Methylocystis sp. M over at least five orders of magnitude (5x10(6) to 5x10(2 )cells/PCR tube, or 2x10(8) to 2x10(4 )cells/ml). Five cells of Methylocystis sp. M per PCR tube (2x10(2 )cells/ml) were detectable when the cells were suspended in distilled water. The concomitant presence of other methanotrophs in samples did not affect the reliability of enumeration; and recovery of the cells with a membrane filter enabled us to quantify cells of the strain in groundwater. This quantification procedure was completed within 3 h, including preparation time of environmental samples. We conclude that real-time PCR using the mmoC primer set can be used practically to analyze the behavior of Methylocystis sp. M at bioremediation sites.

DNA, Bacterial↗
PubMed2001

MM-1, a c-Myc-binding protein, is a candidate for a tumor suppressor in leukemia/lymphoma and tongue cancer.

The c-myc oncogene product (c-Myc) is a transcription factor that dimerizes with Max and recognizes the E-box sequence, and it plays key functions in cell proliferation, differentiation, and apoptosis. We previously showed that MM-1 bound to myc box II within the transactivation domain of c-Myc and repressed the E-box-dependent transcriptional activity of c-Myc. Here we report that MM-1 showed features of a tumor suppressor. In an EST data base search for cDNAs homologous to MM-1, we found a frequent substitution of amino acid 157 of MM-1, from alanine to arginine (A157R), and the substitution was observed more in tumor cells than in normal cells. A survey of the A157R mutation of MM-1 in 57 cultured cancer cells and 90 tissues from cancer patients showed that the A157R was present in about 50-60% of leukemia/lymphoma cells and in more than 75% of squamous cell carcinoma of tongue cancer. Although both the A157R and the wild-type MM-1 bound to c-Myc, only A157R lost the activities to repress both the E-box-dependent transcriptional activity of c-Myc and the myc/ras cooperative transforming activity in rat 3Y1 cells. Furthermore, the wild-type MM-1, but not A157R, arrested the growth of 3Y1 cells. The human MM-1 gene was mapped at chromosome 12q12-12q13, where many chromosome abnormalities in cancer cells have been reported. The results suggest that MM-1 is a novel candidate for a tumor suppressor that controls the transcriptional activity of c-Myc.

3T3 Cells↗
PubMed2001

Synthesis, characterization, and photochemical properties of azobenzene-conjugated Ru(II) and Rh(III) bis(terpyridine) complexes.

We synthesized azobenzene-conjugated bis(terpyridine) Ru(II) and Rh(III) mononuclear and dinuclear complexes and investigated their photochemical properties on excitation of the azo pi-pi band upon 366 nm light irradiation. The Ru mononuclear complex underwent trans-to-cis photoisomerization to reach the photostationary state with only 20% of the cis form, while the Ru dinuclear complex did not isomerize at all photochemically. On the other hand, the mononuclear and dinuclear Rh complexes showed almost complete trans-to-cis photoisomerization behavior. Cis forms of the Rh complexes thermally returned to the trans form at a much slower rate than those of organic azobenzenes, but they did not isomerize photochemically. The reduction potential of the cis forms was 80 mV more negative than that of the trans forms. The photoisomerization quantum yields of the Rh complexes were strongly dependent on the polarity, viscosity, and donor site of the solvents as well as the size of the counterions. We investigated the photoisomerization process of these complexes using femtosecond absorption spectroscopy. For the Rh complexes, we observed S(n) <-- S(2) and S(n) <-- S(1) absorption bands similar to those of organic azobenzenes. For the Ru complexes, we observed very fast bleaching of the MLCT band of the Ru complex, which indicated that the energy transfer pathway to the MLCT was the primary cause of the depressed photoisomerization. The electronic structures, which were estimated from ZINDO molecular orbital calculation, supported the different photochemical reaction behavior between the Ru and Rh complexes.

Journal Article↗
PubMed2001

Matrix vesicles and media vesicles as nonclassical pathways for the secretion of m-Calpain from MC3T3-E1 cells.

Calpain was generally believed to exist and function only in the cytoplasm. However, m-calpain has now been detected in the extracellular spaces of some kinds of tissue. In this study, we demonstrated the existence of m-calpain in the medium surrounding MC3T3-E1 cultures, and its activity by zymography. At the same time, the amount of lactate dehydrogenase in medium of MC3T3-E1 culture was extremely low compared with other cell cultures, suggesting that m-calpain found in the culture medium of MC3T3-E1 cells originated mainly from active secretion. Moreover, the secretion of m-calpain was not blocked by brefeldin A, implying that m-calpain may be secreted by a nonclassical pathway. Recently, MC3T3-E1 has been reported to produce matrix vesicles and media vesicles, and we demonstrated m-calpain in these vesicles produced by MC3T3-E1 cultures. We therefore concluded that these vesicles are partly responsible for the secretion of m-calpain into the culture medium of MC3T3-E1 cells.

Animals↗
PubMed2001

Broad distribution of the JC virus receptor contrasts with a marked cellular restriction of virus replication.

To investigate the early events of JC virus (JCV) infection, including attachment, penetration, transport to the nuclei, and replication of the virus, we analyzed the susceptibility of 15 different cell lines to infection using a semiquantitative polymerase chain reaction (PCR) assay, in situ hybridization, laser scanning confocal microscopy, and a viral replication assay. The cell lines examined were human permissive and nonpermissive cells as well as cells of monkey and mouse origin. JCV entry into the nuclei of the all cell lines was observed within 10 min after inoculation, demonstrating that the virus receptor is widely distributed among mammalian cells. Inhibition of viral entry by an anti-JCV VP1 antibody and sialidase treatment to remove sialic acid residues, which are considered a candidate for the JCV receptor, suggested that VP1 may interact with the cellular surface sialic acid. In addition, chlorpromazine, a clathrin-dependent pathway inhibitor, significantly suppressed entry of JCV into nuclei. In spite of the broad spectrum of cells susceptible to JCV entry, replication of the virus occurred exclusively in human neuroblastoma cell lines. These results suggest that whereas JCV can enter a wide variety of cell types and localize to the nuclei, cell-specific intranuclear mechanisms are required for virus replication.

HeLa Cells↗
PubMed2001

Analysis of transforming activity of human synovial sarcoma-associated chimeric protein SYT-SSX1 bound to chromatin remodeling factor hBRM/hSNF2 alpha.

Human synovial sarcoma has been shown to exclusively harbor the chromosomal translocation t(X;18) that produces the chimeric gene SYT-SSX. However, the role of SYT-SSX in cellular transformation remains unclear. In this study, we have established 3Y1 rat fibroblast cell lines that constitutively express SYT, SSX1, and SYT-SSX1 and found that SYT-SSX1 promoted growth rate in culture, anchorage-independent growth in soft agar, and tumor formation in nude mice. Deletion of the N-terminal 181 amino acids of SYT-SSX1 caused loss of its transforming activity. Furthermore, association of SYT-SSX1 with the chromatin remodeling factor hBRM/hSNF2 alpha, which regulates transcription, was demonstrated in both SYT-SSX1-expressing 3Y1 cells and in the human synovial sarcoma cell line HS-SY-II. The binding region between the two molecules was shown to reside within the N-terminal 181 amino acids stretch (aa 1--181) of SYT-SSX1 and 50 amino acids (aa 156--205) of hBRM/hSNF2 alpha and we found that the overexpression of this binding region of hBRM/hSNF2 alpha significantly suppressed the anchorage-independent growth of SYT-SSX1-expressing 3Y1 cells. To analyze the transcriptional regulation by SYT-SSX1, we established conditional expression system of SYT-SSX1 and examined the gene expression profiles. The down-regulation of potential tumor suppressor DCC was observed among 1,176 genes analyzed by microarray analysis, and semi-quantitative reverse transcription--PCR confirmed this finding. These data clearly demonstrate transforming activity of human oncogene SYT-SSX1 and also involvement of chromatin remodeling factor hBRM/hSNF2 alpha in human cancer.

Agar↗
PubMed2001

Clear cell variant of malignant melanoma of the uterine cervix: a case report and review of the literature.

BACKGROUND: A rare variant of malignant melanoma of the uterine cervix mimicking clear cell carcinoma or clear cell sarcoma is described. CASE: A 33-year-old Japanese woman was admitted to the hospital complaining of genital discharge and lower back pain. The stage was FIGO IIB and radical hysterectomy and pelvic lymphadenectomy were done. Pathological examination, immunohistochemical studies of melanin granules, and molecular analysis of the EWS/ATF-1 fusion gene were also done. A diffuse proliferation of amelanotic clear cells was detected in the uterine cervix. Tumor cells were positive for HMB 45, Melan-A (MART-1), and S-100 protein and negative for epithelial markers. The EWS/ATF-1 fusion gene was not detected. CONCLUSION: This is apparently the first report of a case of clear cell melanoma of the uterine cervix. Despite its rarity, this variant of malignant melanoma should be considered when diagnosing clear cell neoplasms of the uterine cervix.

Adenocarcinoma, Clear Cell↗
PubMed2001

HHV8-negative primary effusion lymphoma of the peritoneal cavity presenting with a distinct immunohistochemical phenotype.

Primary effusion lymphoma (PEL) has been recognized as a body-cavity-based lymphoma that was originally reported to be associated with human herpes virus 8 (HHV8) infection, and was frequently found in human immunodeficiency virus-positive (HIV) patients. Here we describe an autopsy case of PEL of the peritoneal cavity in an immunocompetent patient. Cytological analysis of tumor cells within ascites revealed immunocytochemical features of keratin positivity and CD45 negativity. At autopsy, the presence of a massive volume of ascites as well as diffuse tumor cell infiltrates within the serosa of the intestine and mesenterium were observed. Tumor cells were morphologically similar to anaplastic large-cell lymphoma, but were immunohistochemically positive for keratin and epithelial membrane antigen (EMA). They also showed no reactivity to representative lymphocyte surface markers including CD45, in addition to being negative for CD30 and p80NPM/ALK. Molecular analysis of the tumor cells revealed monoclonality of the immunoglobulin heavy-chain gene rearrangement which demonstrated a lymphoma of the B-cell lineage. Furthermore, HHV8 was not detected by immunohistochemical analysis, PCR or nested PCR technique. Based on these results, we consider the present case to be an HHV8-negative PEL with keratin and EMA positivity.

Adult↗
PubMed2001

Quantitative and specific detection of a trichloroethylene-degrading methanotroph, Methylocystis sp. strain M, by a most probable number-polymerase chain reaction method.

We developed a rapid and specific enumeration method for a trichloroethylene-degrading methanotroph, Methylocystis sp. strain M, based on a most probable number-polymerase chain reaction method for monitoring the bacterium at bioremediation sites. The primers designed for the mmoC gene of the soluble methane monooxygenase gene cluster were specific to strain M. Recovery of the cells with a membrane filter enabled us to detect strain M in trichloroethylene-contaminated groundwater. We used the enumeration method to monitor the number of strain M cells in effluent from soil columns supplied with trichloroethylene-contaminated groundwater. The number of strain M cells in the effluent depended on the amount of the strain M inoculated and the number of cells measured by the most probable number-polymerase chain reaction method was correlated with that measured by a culture method. The detection limit for strain M in effluent detected by MPN-PCR method was 4 to 8 x 10(2) cells/ml.

Biodegradation, Environmental↗
PubMed2001

Analysis of the molecular species of hydrogenase in the cells of an obligately chemolithoautotrophic, marine hydrogen-oxidizing bacterium, Hydrogenovibrio marinus.

Hydrogenovibrio marinus was suggested to have only membrane-bound hydrogenase (MBH). The change of cultivation pO2 did not affect the molecular species of hydrogenase expressed. We propose the MBH is grouped in class I [NiFe] MBH according to the subunit composition, size (Mw 38,000 and Mw 74,000 subunits) and N-terminal sequences of the subunits, and arrangement of the structural genes. Ni-requirement for the autotrophic growth on H2 also suggested the MBH is the Ni-containing type. Southern hybridization analysis using a part of the MBH gene showed a possibility of the presence of two highly homologous MBHs which were not separated by SDS-PAGE.

Amino Acid Sequence↗
PubMed2000

High-resolution CT findings of macrophage activation syndrome: a case report.

Macrophage activation syndrome (MAS) is a rare disorder characterised by benign, reactive, excessive, well-differentiated macrophage proliferation, secondary to an immune dysregulation in response to some triggering agents such as viral infection. We report a 3-year-old girl with MAS and pulmonary involvement. This is the first radiographic description of MAS on high-resolution CT.

Anti-Inflammatory Agents↗
PubMed2000

[Pediatric cataract surgery with posterior capsulorrhexis and optic capture of the intraocular lens].

We evaluated the result of the pediatric cataract surgery with optic capture. The intraocular lens (IOL) optic is subluxated to the vitreous body side through the posterior continuous curvilinear capsulorrhexis (PCCC). Five eyes with congenital or developmental cataracts were treated with phacoemulsification and IOL implantation, and then PCCC and optic capture was done. Three of the cases were bilateral and one case was unilateral. All cases have remained in good condition without secondary fibrous membrane formation, which influences visual acuity, and transparency of the posterior capsule was maintained in the visual axis area. We found one case of anterior capsule contraction. Long-term follow up should be continued.

Capsulorhexis↗