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Biomedical subjects

Y Komatsu

Publications and source records attributed to Y Komatsu.

At least 127 records · Page 7Linked to original sources
PubMed1999

Eradication of Helicobacter pylori using 30 mg or 60 mg lansoprazole combined with amoxicillin and metronidazole: one and two weeks of a new triple therapy.

A new triple therapy using a proton pump inhibitor and two antibiotics shows high efficiency against Helicobacter pylori infection. The aim of this study was to determine the optimal dose and duration of lansoprazole (LA) administration in combination with amoxicillin (AMPC) and metronidazole (MNZ). A total of 91 patients were enrolled in this study. They were divided into four groups: group A, 2 weeks of 30mg LA once daily, 500mg AMPC tid, and 250mg MNZ tid; group B, 2 weeks of 30mg LA bid, 500mg AMPC tid, and 250mg MNZ tid; group C, 1 week of 30mg LA once daily, 500mg AMPC tid, and 250mg MNZ tid; group D, 1 week of 30mg LA bid, 500mg AMPC tid, and 250mg MNZ tid. H. pylori status was determined by the rapid urease test, culture, histology, and 13C-urea breath test before and at least 4 weeks after the end of therapy. The cure rates in a per-protocol analysis and the incidence of adverse events in the evaluated patients were, respectively, 89.5% and 21.1% in group A, 100% and 20.0% in group B, 96.8% and 12.9% in group C, and 92.3% and 26.9% in group D. Most of the adverse events were tolerated. All four regimens in this study showed the same cure rates, and they were effective and well tolerated. One week of triple therapy using once-daily administration of 30mg LA is a good alternative.

2-Pyridinylmethylsulfinylbenzimidazoles↗
PubMed1998

Effect of oral administration of Pinellia ternata, Zingiberis rhizoma and their mixture on the efferent activity of the gastric branch of the vagus nerve in the rat.

The effect of taste stimulation of Pinellia temata, Zingiberis rhizoma and their mixture on the efferent activity of the gastric branch of the vagus nerve was observed in the anesthetized rat. Taste stimulation by Pinellia ternata (50 mg/ml, 10 min) resulted in a suppression in vagal gastric nerve activity. On the contrary, stimulation by Zingiberis rhizoma (50 mg/ml, 10 min) caused a facilitation in efferent activity. The mixture of Pinellia ternata and Zingiberis rhizoma (5:1, 50 mg/ml, 10 min stimulation) demonstrated no suppressive effect on gastric nerve activity. These observations indicate that it is reasonable to prescribe Pinellia ternata with Zingiberis rhizoma in traditional Japanese medicine to prevent suppressive effect of the taste of Pinellia ternata on gastric function.

Administration, Oral↗
PubMed1998

Hsp104 responds to heat and oxidative stress with different intracellular localization in Saccharomyces cerevisiae.

TPN (tetrachloroisophthalonitrile) affected the growth in yeast Saccharomyces cerevisiae and enhanced the superoxide dismutase and glutathione reductase activity under sublethal concentration. Conversely, mild heat-shock treatment had no effect on the enzyme activities. These show they inhibit the metabolism diversely: TPN is an oxidative stressor and mild heat-shock treatment leads to thermogenesis. We have earlier reported that on exposure to TPN under sublethal concentration, heat-shock protein Hsp104 was induced in the same way as in the mild heat-shock treatment (Fujita et al., Biochem. Biophys. Res. Commun. (1995) 216, 1041-1047). However, intracellular localizations of Hsp104 showed different patterns in each treated cell according to immunoelectron microscopic observation. While Hsp104 was localized upon the circumference of the protein aggregates in mild heat-shocked cells, Hsp104 was distributed over the entire TPN-treated cells with no protein aggregates. These findings suggest Hsp104 adaptively responds to comprehensive stress and participates in an emergent rescue function as a molecular chaperone.

Cell Nucleus↗
PubMed1998

31P NMR study of the interactions between oligodeoxynucleotides containing (6-4) photoproduct and Fab fragments of monoclonal antibodies specific for (6-4) photoproduct.

A 31P nuclear magnetic resonance (NMR) study of the interactions between oligonucleotides containing the (6-4) photoproduct and the Fab fragments of monoclonal antibodies (64M3 and 64M5) recognizing the (6-4) photoproduct is reported. The 31P chemical shift data indicate that backbone conformation of (64) adduct is affected by the presence of flanking oligodeoxynucleotides, and (6-4) adducts with different backbone conformations are accommodated in the antigen binding sites of these antibodies. It was also revealed that epitopes for these antibodies consist of not only the (6-4) adduct but the flanking di- or tri-deoxynucleotides on both the 5' and 3' sides as well.

Antibodies, Monoclonal↗
PubMed1998

Involvement of the RpoN protein in the transcription of the oprE gene in Pseudomonas aeruginosa.

OprE is a channel-forming outer membrane protein of Pseudomonas aeruginosa, the expression of which is induced under anaerobic conditions. We constructed various mutants and observed the effects on oprE expression. Deficiency in RpoN, an alternative sigma factor for RNA polymerase, abolished oprE expression under aerobic conditions, but did not affect the expression under anaerobic conditions. One mutation on the putative RpoN recognition site also caused reduction of oprE expression. The region 500 nucleotides upstream of the mRNA start site was required for optimal oprE transcription, which contains an AT-rich region including a putative integration host factor binding site. These results indicate that OprE production is directly or indirectly controlled by RpoN but also require some other regulatory proteins bound to the upstream region.

Aerobiosis↗
PubMed1998

Characterization of the sheep apolipoprotein E (ApoE) gene and allelic variations of the ApoE gene in scrapie Suffolk sheep.

Apolipoprotein E (ApoE) plays a central role in lipid transport and is suggested to be involved in neuronal repair. Human ApoE epsilon 4 allele is known as a risk factor for Alzheimer's disease, and an association of the human ApoE genotype with the human prion disease, Creutzfeldt-Jakob disease, is suggested, albeit controversial. We analyzed the sheep ApoE gene to determine whether any association between the sheep ApoE genotype and the sheep prion disease, scrapie, existed. The sheep ApoE cDNA contained an open reading frame (ORF) consisting of 948 base pairs (bp) that encoded 316 amino acids (aa). The sheep ApoE gene was composed of four exons separated by three introns, and the ORF was encoded by three exons, designated exons 2, 3, and 4. Nucleotide sequence analysis also showed the presence of one G/T nucleotide polymorphism in the ORF that resulted in an Ala/Ser amino-acid substitution at codon 258. PCR-restriction fragment length polymorphism analysis of genomic DNA showed the presence of three sheep ApoE genotypes that were the result of the homologous and heterologous combinations of the two alleles. We analyzed the sheep ApoE genotypic and the allelic frequencies in scrapie and control Suffolk sheep, but they did not significantly differ from those in the control sheep, even though PrP genotype-matched populations were compared. The ApoE genotype appeared not to be associated with the progression of the disease when looking at the age at death. These results indicated that in Suffolk sheep, none of the ApoE genotypes was associated with scrapie.

Alleles↗
PubMed1998

Stabilization of two families of critical targets for hyperthermic cell killing and acquired thermotolerance of yeast cells.

Hyperthermic cell killing profiles of Saccharomyces cerevisiae cells were biphasic and a shoulder (phase 1) was followed by an exponential killing (phase 2). Assuming that (i) the rate of thermal damage in particular macromolecules or their assemblies limits the rate of hyperthermic cell killing (the critical target model), and (ii) the damages of two families of targets are lethal independently, we built a 'dual critical target model' in order to interpret the biphasic cell killing. Time-courses of temperature-programmed fractional survival were traced for S. cerevisiae cells in exponentially growing phase, heat shocked, and in stationary phase. Non-linear curve-fitting of the time-courses by using the dual critical target model provided the Arrhenius parameters of denaturation of the two families of targets. The cells were killed more slowly in phase 1 than in phase 2. Arrest in stationary phase, not heat shock, stabilizes the family of targets that is critical to phase 1 death. On the other hand, both heat-shock response and arrest in stationary phase stabilizes the other family of targets that, in addition to the previous one, is responsible for phase 2 death.

Hot Temperature↗
PubMed1998

Inhibition by dexamethasone of transforming growth factor beta1-induced apoptosis in rat hepatoma cells: a possible association with Bcl-xL induction.

The authors previously reported that transforming growth factor beta1 (TGF-beta1) induces apoptosis in McA-RH7777 (7777) and McA-RH8994 (8994) rat hepatoma cell lines. Although these cell lines exhibit different responses to glucocorticoid treatment in various cellular functions and gene expression, dexamethasone (DEX) inhibited spontaneous and TGF-beta1-induced apoptosis in both. Analysis of analogous hormones in TGF-beta1-induced apoptosis in 8994 cells suggested the inhibitory effect to be glucocorticoid-specific. By cell-cycle analysis and DNA fragmentation assay using sodium butyrate, a G1-arrest-inducing reagent, regulation of apoptosis by TGF-beta1 and DEX was shown independent of the cell cycle. For elucidation of the mechanisms of anti-apoptotic action of DEX, the effects of various chemical probes on this apoptosis model were examined, and various reagents known to exhibit anti-apoptotic activity in other experimental systems were found to be ineffective. The effect of TGF-beta1 and DEX on cellular amounts of several apoptosis-related proteins, members of the Bcl-2 family, Bcl-2, Bcl-xL, Bcl-xS, Bad, and Bax was also examined. DEX drastically increased Bcl-xL in both cell lines irrespective of the presence of TGF-beta1. Bcl-2 and Bcl-xS proteins were not detected, and Bax and Bad content did not change by treatment with TGF-beta1 or DEX. Progesterone (Prog), a partial antagonist for glucocorticoid receptor, inhibited the effects of DEX on apoptosis and Bcl-xL expression in 8994 cells. Thus, Bcl-xL induction by DEX would appear closely associated with its inhibitory effect on spontaneous and TGF-beta1-induced apoptosis in the hepatoma cell lines.

Animals↗
PubMed1998

pp60c-src activation in hepatocellular carcinoma of humans and LEC rats.

For the related Src kinases, a close correlation exists between elevated tyrosine kinase activity and cell transformation. However, the involvement of pp60c-src in hepatocellular carcinoma (HCC) remains obscure. The aim of this study was to evaluate whether pp60c-src tyrosine kinase activity is elevated in HCC. We analyzed the kinase activity of pp60c-src in normal liver tissue, chronic hepatitis liver tissue, and tumorous and adjacent nontumorous portions of HCC tissue from patients and Long-Evans cinnamon (LEC) rats that are known to develop liver cancer spontaneously. The kinase activity of pp60c-src was rarely detected in the normal human liver tissue and chronic hepatitis liver tissue, but it was elevated in tumorous and nontumorous portions of HCC tissue. Furthermore, the kinase activity of pp60c-src was significantly elevated in tumorous tissues compared with nontumorous tissues. The kinase activity of pp60c-src was also higher in poorly differentiated HCC. In addition, the kinase activity of pp60c-src increased proportionately with the development of HCC of LEC rats. Our results suggest that activation of the protooncogene product pp60c-src may play an important role in the malignant transformation of hepatocytes in human and LEC rats, and that it may be closely related to the histopathological grading of human HCC.

Animals↗
PubMed1998

Reduced reactivity of pancreatic exocrine secretion in response to gastrointestinal hormone in WBN/Kob rats.

We compared pancreatic exocrine secretion in 5-month-old WBN/Kob rats, a model of chronic pancreatitis, with that in Wistar rats of the same age in a conscious state. Basal pancreatic secretion and pancreatic wet weight in WBN/Kob rats were lower than the values for Wistar rats. There was no difference in plasma cholecystokinin (CCK) concentration between the two types of rats. When CCK-8 was intravenously administered, the stimulation of pancreatic protein secretion in WBN/Kob rats was weaker than that in Wistar rats. When bile and pancreatic juice were diverted from the duodenum, the resulting increase in the plasma CCK concentration was similar in both types of rats, but stimulation of the volume and protein output of pancreatic juice in WBN/Kob rats was weaker than that in Wistar rats. In addition, WBN/Kob rats exhibited little increase in pancreatic wet weight because of this diversion. When secretin was intravenously administered, the stimulation of fluid secretion in WBN/ Kob rats was also weaker than that in Wistar rats. The binding of CCK-8 to pancreatic membrane fractions in WBN/Kob rats was much weaker than that in Wistar rats. Histological findings in WBN/Kob rat pancreas showed proliferation of fibrous tissue and atrophy of acinar cells. In conclusion, pancreatic exocrine secretion in response to the gastrointestinal hormones, CCK and secretin, was lower in WBN/Kob rats than in Wistar rats. These findings suggest that the hyposecretion of pancreas in WBN/Kob rats is hyporeaction of pancreatic membrane to gastrointestinal hormones.

Animals↗
PubMed1998

Inhibitory effects of Dai-saiko-to (Da-Chai-Hu-Tang) on the progression of atherosclerotic lesions in Kurosawa and Kusanagi-hypercholesterolemic rabbits.

The inhibitory effects of the traditional herbal medicine Dai-saiko-to (Da-Chai-Hu-Tang) on the progression of the atherosclerotic lesions were studied using the spontaneous familial hypercholesterolemia (FH) model, Kurosawa and Kusanagi-hypercholesterolemic (KHC) rabbits. Changes in blood chemistry, pathology and low-density lipoprotein (LDL) oxidation were measured in a control group and a Dai-saiko-to-treated group. In the control group, the area of atheromatous plaques of the aorta progressed between week 12 (29.1%) and 26 (51.5%). This progression of atherosclerotic lesions did not happen in the Dai-saiko-to-treated group between week 12 (26%) and 26 (27.4%). Antioxidative effects on LDL were seen in the Dai-saiko-to-treated group in weeks 16 and 18. Dai-saiko-to did not improve the hypercholesterolemia in the KHC rabbits. These results suggest that Dai-saiko-to has inhibitory effects on the development of atheromatous plaque formation in spontaneous FH model rabbits. It is possible that the antioxidative effects of Dai-saiko-to on LDL led to the beneficial effects observed in this study.

Animals↗
PubMed1998

Quantitative analysis of ras gene mutation in pancreatic juice for diagnosis of pancreatic adenocarcinoma.

It has recently been demonstrated that mutant ras gene was also detected in patients with mucinous cell hyperplasia without adenocarcinoma, indicating that the presence of the mutation could not be a definite marker for pancreatic adenocarcinoma. The present study was performed to differentiate pancreatic adenocarcinoma from others by quantification of mutant ras gene in pancreatic juice. By measuring mutant ras gene by polymerase chain reaction (PCR) during its logarithmic phase, the amount was semiquantitatively evaluated between 0.1 and 10% of total DNA that was extracted from pancreatic juice obtained via endoscopy. Semiquantitative analysis revealed that the mutant gene occupied more than 1% of total DNA in eight of 15 patients (53%) with pancreatic adenocarcinoma, and in all three patients (100%) with intraductal papillary neoplasm of the pancreas, but in only two of 19 cases (11%) without neoplasm. Semiquantitative analysis may provide a clinical tool for the differential diagnosis of pancreatic carcinoma.

Adenocarcinoma↗
PubMed1998

Endoscopic papillary balloon dilation for the management of common bile duct stones: experience of 226 cases.

BACKGROUND AND STUDY AIMS: Endoscopic sphincterotomy is a widely accepted technique for the treatment of patients with common bile duct stones. However, it is still associated with occasional complications. The recently developed technique of endoscopic papillary balloon dilation seems to be a safe and effective procedure, and to have great potential for replacing endoscopic sphincterotomy. However, few reports have been published on the use of this technique for bile duct stones. The present study was undertaken to evaluate its safety and efficacy. PATIENTS AND METHODS: Endoscopic papillary balloon dilation was used to remove common bile duct stones in 226 consecutive patients including 41 patients of ASA classification III/IV, 41 elderly patients (> 80 years) 24 with liver cirrhosis, and 86 with periampullary diverticulum. After dilation of the papilla with a balloon diameter of 8 mm, the stones were retrieved. RESULTS: In conjunction with the use of a mechanical or/and electrohydraulic lithotriptor in 79 patients (35%) with large stones (> 10 mm in diameter), clearance of the common bile duct was achieved in 225 of 226 patients (99%) without serious complications, such as hemorrhage or severe pancreatitis; mild (n = 13) or moderate (n = 2) pancreatitis occurred in 7% of cases. CONCLUSIONS: Endoscopic papillary balloon dilation is a safe and effective technique for the treatment of common bile duct stones, even in high-risk patients.

Adult↗
PubMed1998

Modification and application of self-trimming hairpin ribozymes to targeting a transcribed RNA in vitro.

The three-domain hairpin ribozyme was improved by increasing the number of linker bases connecting domain I' with domain II from six to seven, and a new ribozyme was designed to release a trans-acting ribozyme that is able to bind with target RNAs by three hybridizing arms. The trans-cleavage activities of the trimmed ribozyme were used to cleave a long target RNA, with 85 bases transcribed from a synthetic gene encoding induced nitric oxide synthase (iNOS). Although the ribozyme with three-hybridizing arms did not efficiently cleave the long target RNA, the overall activity, from self-trimming to the trans-cleavage reaction of the target RNA, was higher than that of the ribozyme with two hybridizing arms.

Base Sequence↗
PubMed1998

The improved image of indocyanine green angiography in young healthy volunteers.

PURPOSE: The authors performed indocyanine green (ICG) angiography in healthy volunteers using a high resolution ICG video system to obtain baseline images for subsequent studies. METHODS: Ten eyes of 10 healthy, young volunteers were studied. Before ICG angiography, all eyes were examined ophthalmoscopically and biomicroscopically and found to be intact. Indocyanine green (50 mg) dissolved in 2 mL of distilled water was injected through the antecubital vein. Video ICG angiogram was recorded until 30 minutes after the dye injection. RESULTS: Although the choroidal dye filling varied among subjects, it always began in the macular area. In the 10 volunteers, initial dye filling had two patterns: flush (n = 2) and reticular (n = 8). Patchy dye-filling delay in the posterior fundus was a common finding (n = 9). Vertical filling delay running between the medial and nasal cilial arteries was observed in nine eyes. The choroidal circulation filled completely before the retinal circulation did. At 30 minutes after dye injection, interstitial tissue staining of the choroid and vascular silhouette resulting from dye washout was observed in all eyes. CONCLUSIONS: Arterioles and capillaries of the choroid were well delineated by ICG angiography, resulting in better understanding of the physiologic and pathologic conditions of the choroidal circulations and the chorioretina itself.

Adult↗