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Biomedical subjects

S Kitaoka

Publications and source records attributed to S Kitaoka.

At least 19 recordsLinked to original sources
PubMed2004

Fhit expression in human gastric adenomas and intramucosal carcinomas: correlation with Mlh1 expression and gastric phenotype.

The fragile histidine triad (FHIT) gene, encompassing the FRA3B fragile site at chromosome 3p14.2, is a candidate tumour suppressor gene involved in a variety of tumours, including gastric carcinomas. Recently, it has been reported that the FHIT gene may be a target of damage in some of mismatch-deficient tumours. To clarify further the role of the Fhit protein in gastric carcinogenesis, we investigated whether Fhit expression in early gastric neoplasia is associated with mismatch repair protein expression and cellular phenotype. Fhit, Mlh1 and phenotypic expression were evaluated immunohistochemically in 87 early gastric neoplasias, comprising 32 adenomas and 55 intramucosal carcinomas, resected by endoscopic mucosal resection therapy. Significant loss or reduction of Fhit expression was noted in four (12.5%) of the 32 adenomas and 21 (38.2%) of the 55 intramucosal carcinomas. The rate of abnormal Fhit expression was significantly higher in intramucosal carcinomas than in adenomas (P=0.021). Moreover, reduced Fhit expression was found to be significantly associated with loss of Mlh1 expression in early gastric neoplasia (P=0.0011). Furthermore, we also detected a significant association between reduced Fhit expression and gastric phenotype (P=0.0018). These results suggested that reduced Fhit expression occurs in the early stage of gastric carcinogenesis and could be correlated with a lack of Mlh1 expression and gastric phenotype.

Acid Anhydride Hydrolases↗
PubMed2003

Effects of deicing salt on the vitality and health of two spruce species, Picea abies Karst., and Picea glehnii Masters planted along roadsides in northern Japan.

In northern Japan, the growth of Picea abies Karst., and Picea glehnii Masters, which have been planted along the highways, is often suppressed due to several environmental stresses. To examine the adverse effects of deicing salt, the primary source of stress,we measured needle life span, photosynthetic capacity, and water potential and transpiration rate of the two spruce species at a site with damaged trees, near the roadside and a site with healthy trees, located far from the highway. Results from the analysis showed large amounts of sodium and chlorine in the soil and snow at the damaged site. These elements had accumulated in the needles of the spruce. Moreover, physiological traits of the spruce, at the damaged site were also affected. Therefore, we concluded that poor physiological traits might be attributed to an accumulation of deicing salt in the needles, resulting in the suppression of tree growth.

Absorption↗
PubMed2001

Transfection of fluorescent probed antisense compounds: L-cysteine derivatives of nucleic acid bases.

Antisense with L-cysteine derivative (CAS) can recognize DNA and forms the complementary duplex with DNA. So the properties of CAS in vitro and in vivo were examined in this study. CAS was resistant to proteinase K and stabilized RNA against RNase HI. Moreover using fluorescent CAS, the localization was observed by fluorescence microscope and confocal microscope. As a result, CASs were accumulated inside the nucleus in NG108-15.

Adenine↗
PubMed2001

Study about the inhibition of L-cysteine derivatives of nucleic acid bases in protein production.

Isopoly (S-carboxymethyl-L-cysteine) derivatives of nucleic acids bases were prepared as antisense compounds. In past study, we investigated the properties of these compounds in vitro, and revealed that these compounds in vivo regulated the cell death presumably due to the inhibition of protein production. In this study, western and northern blots were carried out in order to reveal the mechanism of this inhibition for N-methyl-D-aspartate receptor in neuroblastoma x glioma hybrid NG108-15 cell line. In addition, we investigated the resistance of these compounds against cell extract and the metabolism. In conclusion, we proved that these compounds inhibited the protein production by antisense mechanism.

Animals↗
PubMed2001

Declining trend in the in-hospital case-fatality rate from acute myocardial infarction in Miyagi Prefecture from 1980 to 1999.

The case-fatality rate from acute myocardial infarction (AMI) appears to have been declining in recent decades, so the present study reviewed the trend in in-hospital case-fatalities from AMI in Miyagi Prefecture, Japan, 1980-1999. The causes of death and the effects of gender and age on the trend were also analyzed. From the AMI registration database of the Miyagi Study Group for AMI, 12,961 cases of AMI were analyzed. The 30-day in-hospital case-fatality was calculated from the data for 1980-1999: data for causes of death were available for 1980-1997, and the data concerning primary percutaneous transluminal coronary angioplasty (PTCA) for AMI were available for 1997-1999. The in-hospital case-fatality rate declined from 17.0% in the early 80s to 7.3% in the late 90s (approximately 57% reduction). The in-hospital case-fatality rate was higher in female patients. Rhythm failure substantially decreased in the late 1980s. Pump failure is decreasing, but is still the biggest problem. The in-hospital case-fatality rate was significantly lower in patients received PTCA. The declining trend in the in-hospital case-fatality rate suggests the benefits of current therapeutic procedures, including primary PTCA, for AMI. Pump failure is an important target for further decreasing the trend.

Adult↗
PubMed2001

Uptake and accumulation of exogenous docosahexaenoic acid by Chlorella.

Tuna oil or its hydrolysate was added to a culture of Chlorella for its nutritional fortification as a feed for rotifer. Exogenous docosahexaenoic acid (DHA) in its free form was taken up by the cells of Chlorella vulgaris strain K-22 and by other strains, but tuna oil was not taken up by the cells. Accumulated DHA was found by electron microscopy in the cells in oil droplets. All strains of Chlorella used in these experiments took up exogenous DHA into the cells. It seems that the structure of the cell wall did not affect the uptake of DHA into the Chlorella cells.

Animals↗
PubMed2000

The behavior and effect of isopoly (S-carboxymethyl-L-cysteine) derivatives of nucleic acid bases.

Isopoly(S-carboxymethyl-L-cysteine) derivatives of nucleic acid bases were prepared as antisense compounds. These compounds in vitro have been found to form stable complex with oligo-DNA or RNA. This paper deals with effect of antisense compounds in vivo. The target in this paper is the sequence of the PSD-95 protein linked with NMDA receptor. Excess passing of calcium ions through the loss of the signal pathway without PSD-95 proteins caused by antisense compound. The cells detailing with L-cysteine derivatives showed the lowest percentage of 19.1%. The data were compared with that of phosphotioate antisense compound.

Animals↗
PubMed1999

Fluorescent probe and permeability to cells of isopoly (S-carboxymethyl-L-cysteine) derivative of nucleic acid bases.

Isopoly(S-carboxymethyl-L-cysteine) derivatives of nucleic acid bases were found to form stable complex with oligo-DNA in vitro. Fluorescent probed isopoly(S-carboxymethyl cysteine) derivatives of nucleic acid bases were prepared as antisense oligomers. The transfection of the oligomer into cells was carried out by HVJ-liposome method. Fluorescence was observed from the cells treated with HVJ-liposome including fluorescent probed oligomers.

Animals↗
PubMed1998

Mutation in the exon 10 (R173W) of the hydroxymethylbilane synthase gene in two unrelated Japanese families with acute intermittent porphyria.

Acute intermittent porphyria (AIP) is an inherited disorder characterized by a deficiency of hydroxymethylbilane synthase (EC 4.3.1.8.; HMBS), the third enzyme in the heme biosynthetic pathway. To date, 113 different HMBS gene mutations have been reported in the world. However, there were a few reports of the gene mutations in the Japanese AIP patients. We studied the gene mutation in two unrelated AIP families in the San-in district, a local area of Western Japan. The overlapping 6 fragments of the HMBS gene, amplified by the reverse transcript-polymerase chain reaction, were analyzed by the single-strand conformation polymorphism with silver staining technique. The abnormal fragment from a member of one family was sequenced to detect the C to T substitution at 517 nucleic acid position of cDNA, which led to a missense mutation of arginine to tryptophan exchange at an amino acid level (R173W). This mutation located in exon 10 created a new site of the MSP 1 restriction endonuclease and was screened by the amplified fragment of exon 10 from genomic DNA with the MSP 1 digestion. The mutation was detected totally in three members of the family and interestingly also in two patients of an unrelated family. This mutation has been reported widely in the world independently, such as in a Swedish, a Canadian, a Finnish, and a French family, but is the first in Japanese patients. The screening method for this mutation is useful for diagnosis in Japanese AIP patients.

Adult↗
PubMed1998

Clinical significance of serum soluble Fas ligand in patients with acute self-limited and fulminant hepatitis.

The Fas ligand (FasL), a member of the tumor necrosis factor family, induces apoptosis in Fas-expressing cells. A matrix metalloproteinase-like enzyme cleaves the membrane-bound FasL to produce the soluble FasL (sFasL). Since FasL has been reported to play a pivotal role in the development of hepatitis, we evaluated clinical significance of serum sFasL in acute liver injury including acute self-limited and fulminant hepatitis. Serum sFasL in 19 patients including 12 with acute self-limited hepatitis and 7 with fulminant hepatitis was measured by an enzyme-linked immunosorbent assay (ELISA). The clinical data consisted of 18 indices including age, sex, liver function tests, hepatocyte growth factor (HGF), outcome and sFasL. Serum sFasL in fulminant hepatitis is 0.06+/-0.01 ng/ml, being identical to that in acute self-limited hepatitis, Serum sFasL is positively correlated with AST and ALT (p<0.0001 and p<0.0001). The factors associated with outcome of the patients were HGF, albumin, prothrombin time, platelet count, cholinesterase and leukocyte count in this order. Serum sFasL serves as an indicator of liver injury in acute self-limited and fulminant hepatitis.

Acute Disease↗
PubMed1996

Transmural potential changes associated with the in vitro absorption of theanine in the guinea pig intestine.

Theanine, L-N-ethylglutamine, is one of the major components of amino acids in Japanese green tea. To characterize the mode for intestinal absorption of theanine, the ionic dependency and kinetic properties of the theanine- and glutamine-evoked transmural electrical potential difference changes (delta PD) were investigated in vitro by using everted sacs prepared from the guinea pig ileum. Both theanine and glutamine applied to the luminal side induced dose-dependent increases in delta PD (increase in serosal positive value). The theanine- and glutamine-evoked delta PD values conformed to the Michaelis-Menten relationship, with delta PDmax not being different, whereas the half-saturation concentration was lower for glutamine (3.1 +/- 0.2 mM) than for theanine (21.4 +/- 0.6 mM). The theanine-evoked delta PD value was much smaller when theanine was applied in the presence of glutamine than when applied alone. The theanine- and glutamine-evoked delta PD values were both inhibited by removing Na+ from the luminal solution. These results suggest that the intestinal absorption of theanine and glutamine is mediated by a common Na(+)-coupled co-transporter in the brush-border membrane, the affinity of which is lower for theanine than for glutamine.

Animals↗
PubMed1995

Mitochondrial alcohol dehydrogenase from ethanol-grown Euglena gracilis.

The inducing effects of ethanol on alcohol dehydrogenase and the key enzymes of the glyoxylate cycle, isocitrate lyase and malate synthase, in Euglena cells were investigated. Ethanol as the sole carbon source resulted in increases in alcohol dehydrogenase and the two glyoxylate cycle enzymes. The experimental results indicated that ethanol is assimilated by alcohol dehydrogenase and the glyoxylate cycle in Euglena. Mitochondria from aerobically grown Euglena contain a unique type of alcohol dehydrogenase that accounts for their ability to respire with ethanol as a substrate. This alcohol dehydrogenase was purified to homogeneity from ethanol-grown Euglena gracilis. The mitochondrial alcohol dehydrogenase was NAD(+)-specific but not NADP(+)-specific. Ethanol was the most active substrate, but the enzyme was also active towards 1-butanol, 1-heptanol, cinnamyl alcohol, and myristyl alcohol. These results indicated that mitochondrial alcohol dehydrogenase participated in alcohol metabolism in Euglena gracilis.

Alcohol Dehydrogenase↗
PubMed1995

Detection of Rickettsia japonica in Haemaphysalis longicornis ticks by restriction fragment length polymorphism of PCR product.

PCR was applied to the detection of Rickettsia japonica, the causative agent of Oriental spotted fever (OSF), in ticks collected at two sites of the Muroto area on Shikoku Island, a major area in Japan where OSF is endemic. Primer pair Rr190.70p and Rr190.602n of the R. rickettsii 190-kDa antigen gene sequence of Regnery and others (R.L. Regnery, C.L. Spruill, and B.D. Plikaytis, J. Bacteriol. 173:1576-1589, 1991) primed the DNA extracted from Haemaphysalis longicornis ticks but not those extracted from Haemaphysalis formosensis, Haemaphysalis flava, Haemaphysalis hystricis, or Amblyomma testudinarium ticks. Digestion of the amplification product with the restriction endonucleases PstI and AluI produced the restriction fragment length polymorphism pattern specific to R. japonica. The HindIII and MspI digests gave restriction fragment length polymorphism patterns identical to those of the PCR product from R. japonica DNA. Hemolymph preparations of H. longicornis ticks were demonstrated to contain rod-shaped organisms that were detected by immunofluorescence with the monoclonal antibody specific to R. japonica species. The primer pair did not amplify the DNA of a laboratory colony of H. longicornis ticks originally collected at an area where OSF is not endemic. Our results provided evidence that H. longicornis ticks might be an arthropod reservoir for R. japonica and a vector of OSF.

Animals↗
PubMed1995

[Treatment of the porphyrias].

There are seven porphyrias which are caused by defective functions of the enzymes in the haem biosynthesis. The clinical classification of porphyrias are divided into three types which are neuroporphyria, neurocutaneous porphyria and cutaneous porphyria. For acute porphyric attack of neuroporphyria and neurocutaneous porphyria, the treatments of choice are administration of glucose and/or hematin, haem arginate and tinprotoporphyrin. Porphyria cutanea tarda in cutaneous porphyria is controlled by removal of iron by phrebotomies or low-dose chloriquine. A novel approach of intravenous administration of interferon may be useful to control the associated case of chronic hepatitis type C. Skin symptoms in erythropoietic protoporphyria can be alleviated with beta carotene. Hepatic failure due to protoporphyria may need a liver transplantation. Cimetidine, a H2-receptor antagonist, may be useful in the treatment of acute porphyric attack and in remission stage in neuroporphyrias, neurocutaneous porphyrias and cutaneous porphyrias such as porphyria cutanea tarda and protoporphyria.

Bloodletting↗