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M Kurihara

Publications and source records attributed to M Kurihara.

At least 19 recordsLinked to original sources
PubMed2005

Short communication: Amino acids antagonistic to the amino acids inhibitory for growth rate of mixed ruminal bacteria.

Antagonism of some amino acids (AA) to the inhibitory effects of other AA (Ile, Phe, and Thr) on the growth rate of mixed ruminal bacteria was investigated. In vitro growth rate of the mixed ruminal bacteria was inhibited when the 3 inhibitory AA (1 mM each) were each added to individual control treatments in which an ammonium salt was included as a sole N source. The inhibitory effect caused by Ile was relieved by addition of Leu or Val (equimolar to Ile), and no significant inhibition was shown when both Leu and Val were added together with Ile. The growth inhibition caused by Phe was also alleviated by supplementing with Trp, and was completely negated by adding Tyr. The inhibitory effect of Thr, on the other hand, was not affected by addition of Lys or Met (which are synthesized using a common pathway with Thr), but was mitigated by supplementation with Glu, Ser, Val, Ala, or Gln. Among the antagonistic AA, Leu, Val, Trp, Tyr, and Glu were indispensable for the maximum growth rate of the ruminal bacteria under the experimental condition of supplementation of amino-N, the removal of which from a mixture of 20 protein AA caused the growth rate to decline. Removals of Ile along with Leu or Val or both, of Phe along with Trp or Tyr, and of Thr along with Glu recovered the promotion of bacterial growth rate. It was concluded that inhibitions of the bacterial growth rate caused by Ile, Phe, or Thr could be antagonized by some other AA (Leu, Val, Tyr, Trp, or Glu), and the role of these latter AA as relievers of the inhibitory effects could explain why they are indispensable for maximum growth rate of ruminal bacteria.

Amino Acids↗
PubMed2004

Bombyx mori nucleopolyhedrovirus orf8 encodes a nucleic acid binding protein that colocalizes with IE1 during infection.

This report describes the characterization of the Bombyx mori nucleopolyhedrovirus (BmNPV) orf8 gene. Immunoblot analyses demonstrated that orf8 was expressed as an early gene. The ORF8 protein accumulated in the nucleus, and was maintained at relatively constant levels from 4 to 24 h postinfection. Immunoblot analysis failed to detect ORF8 protein associated with budded virus and occlusion derived virus. In addition, immunohistochemical analysis by confocal microscopy showed that ORF8 protein colocalized with IE1 to specific nuclear foci throughout infection. To further examine the function of ORF8, a reporter gene was inserted into the orf8 reading frame. One orf8 disruption mutant (BmD8), which expressed the N-terminal half of ORF8, was isolated. However, it was not possible to isolate a null mutant, suggesting that orf8 may have an important role during viral infection. Single-step growth curves showed that BV production was reduced in BmD8 infected cells. Biochemical analyses indicated that ORF8 bound to nucleic acids. Together, these results suggest that BmNPV ORF8 may be involved in viral DNA replication and/or transcription.

Animals↗
PubMed2004

Phylogenetic analysis of methyl coenzyme-M reductase detected from the bovine rumen.

AIMS: The object of the present study is isolation of methyl coenzyme-M reductase (MCR) genes (mcrA) from the bovine rumen fluid and determination of phylogenetical placements of the genes to investigate mechanisms of methanogenesis in the rumen from a point of view of mcrA genes. METHODS: Genes for methanogen-specific MCR were isolated from the bovine rumen by PCR amplification. The deduced amino acid sequences were fitted to the alignments of mcrA gene products from the referred sequences. SIGNIFICANCE AND IMPACT OF THE STUDY: Although the deduced amino acid sequences of mcrA genes, isolated from the bovine rumen in the present study, were close to that of Methanobrevibacter ruminantium, these amino acid sequences did not fall into known clusters of MCR. The findings suggest that methanogenesis in the rumen would be partially carried out by unknown methanogens.

Animals↗
PubMed2004

Meta-analysis on the validity of pepsinogen test for gastric carcinoma, dysplasia or chronic atrophic gastritis screening.

AIM: To assess the validity of the measurement of pepsinogen I and II as a screening test for gastric cancer and pre-malignant lesions, namely low-grade dysplasia, both in the general population and in selected groups of patients. METHODS: A meta-analysis of sensitivity and specificity results from individual papers on the use of the pepsinogen test. An intrinsic cut-off effect was assumed and a random effect model was used for pooling. RESULTS: Forty-two data sets were included: 27 (64%) population-based screening studies (n=296,553) and 15 (36%) sets of selected individuals (n=4385). Homogenous sensitivity and diagnostic odds ratio (DOR) estimates were found in studies using both pepsinogen I levels and pepsinogen I/II ratio calculations. Pooled pairs of sensitivity and false positive rates (FPr) for pepsinogen I < or = 70; pepsinogen I/II ratio < or = 3, pepsinogen I < or =50; pepsinogen I/II ratio < or = 3, and pepsinogen I < or = 30; pepsinogen I/II ratio < or = 2, were sensitivity 77%/FPr 27%, sensitivity 68%/FPr 31%, and sensitivity 52%/FPr 84%, respectively. Positive predictive values (PPV) varied between 0.77% and 1.25%, and negative predictive values (NPV) varied between 99.08% and 99.90%. In selected groups, pooling was only possible when considering pepsinogen I < or = 70; pepsinogen I/II ratio < or = 3: giving sensitivity 57%, specificity 80%, PPV 15% and NPV 83%. As for the diagnosis of dysplasia, studies considering pepsinogen I <50; pepsinogen I/II ratio <3 obtained sensitivity 65% and specificity ranging from 74%-85%, both with NPV >95%. CONCLUSION: Pepsinogen test definition should include pepsinogen I/II ratio as consistency was obtained, both in population based studies and in selected groups for those studies that used pepsinogen I serum levels together with pepsinogen I/II ratio for screening for gastric cancer in high-incidence regions other than Japan. Further studies of this test in the management of high-risk patients seem to be worthwhile.

False Positive Reactions↗
PubMed2002

Detection of Proteobacteria from the rumen by PCR using methanotroph-specific primers.

AIMS: To detect Proteobacteria, including methanotrophs, from the rumen fluid and the bacteria inhabiting the rumen epithelium. METHODS AND RESULTS: Proteobacteria inhabiting the rumen were detected by PCR using methanotroph-specific primers. The detected Proteobacteria were divided into clusters A, B, and C in addition to one clone, which was distinct from the clusters and closely related to Nitrosomonas sp. The clusters A, B, and C were close to Succinivibrio dextrinosolvens, Enterobacter cloacae, and Actinobacillus minor, respectively. The clones obtained from the rumen fluid each belonged to cluster A or B. The clones obtained from the rumen epithelium belonged to cluster B or C or to Nitrosomonas sp. CONCLUSIONS: It has been assumed that the rumen fluid and the rumen epithelium host different populations of Proteobacteria. Moreover, detection of Nitrosomonas from the rumen epithelium would indicate the possibility that the bacterium oxidizes ammonia and methane on the rumen surface. SIGNIFICANCE AND IMPACT OF THE STUDY: These findings suggest that the rumen fluid and the epithelium support different microbial populations, which would play specific roles in rumen function. Future study should focus on the relationship between these communities and physiological functions in the rumen.

Animals↗
PubMed2001

Efficient and versatile synthesis of novel 2alpha-substituted 1alpha,25-dihydroxyvitamin D(3) analogues and their docking to vitamin D receptors.

Novel 2alpha-substituted 1alpha,25-dihydroxyvitamin D(3) analogues with 2alpha-alkyl and 2alpha-hydroxyalkyl groups were systematically synthesized from D-xylose. Their conformation on binding to the ligand binding domain (LBD) of the vitamin D receptor was analyzed. It has been found that the 2alpha-hydroxypropyl group best fits the cavity of the LBD, and the binding activity is three times higher than that for the natural hormone.

Calcitriol↗
PubMed2001

Photochemical generation of nitric oxide from 6-nitrobenzo[a]pyrene.

Photolabile 6-nitrobenzo[a]pyrene (6-nitroBaP) released nitric oxide (NO) under visible-light irradiation. The generation of NO and the concomitant formation of the 6-oxyBaP radical were confirmed by ESR. BaP quinones were also detected as further oxidized products of the 6-oxyBaP radical. No such photodegradation was observed with other nitrated BaPs, such as 1-nitroBaP and 3-nitroBaP. DNA-strand breakage, caused by photoexcited 6-nitroBaP, was closely related to its NO-releasing activity. MO calculations of nitrated BaP suggest that the perpendicular conformation of the nitro substituent to the aromatic ring is important for the release of NO with light. These findings may be useful for the development of a new type of NO donor.

Benzopyrenes↗
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

The impact of traumatic brain injury on family members living with patients: a preliminary study in Japan and the UK.

PURPOSE: To ascertain the views of families living with TBI patients about the nature of the problems experienced as a result of TBI, and to compare the views of Japanese family members (J-FM) and British family members (B-FM) in order to find out whether there were cultural differences in family response to TBI. METHODS: Family members involved in providing care were identified by the patients. Face to face interviews were conducted with all 18 carers in B-FM and four carers in J-FM. The remaining eight carers in J-FM participated in the postal questionnaire. Questionnaires were developed to explore the nature of problems and the involvement of family such as social embarrassment. RESULTS: Problems arising in families were almost the same reported from both groups. However families in B-FM were likely to know more about how to cope with these problems. Family members in J-FM reported more statistically significant increases in social embarrassment than those in B-FM. CONCLUSION: The preliminary results showed that family members living with TBI patients in both groups had experienced problems. Appropriate rehabilitation services should be developed to help families as well as TBI patients in Japan.

Adaptation, Psychological↗