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Biomedical subjects

A Yasui

Publications and source records attributed to A Yasui.

At least 127 records · Page 7Linked to original sources
PubMed1989

Sphincter of Oddi response to caerulein after endoscopic sphincterotomy for papillary stenosis.

Using a percutaneous transhepatic cholangioscopy (PTCS) catheter, sphincter of Oddi motility was measured in a patient with papillary stenosis secondary to bile duct stones. Prior to sphincterotomy, intramuscular injection of 20 micrograms caerulein did not inhibit pathological contraction waves of the sphincter of Oddi or relieve abdominal pain. Endoscopic sphincterotomy of the lower segment of the sphincter of Oddi resulted in recovery of the normal response to caerulein, i.e. relaxation of the sphincter of Oddi. This observation indicates that the pathological contraction and lack of relaxation to cholecystokinin in a patient with papillary stenosis is due to high common bile duct pressure. The measurement of motility of sphincter of Oddi via the PTCS route is useful in diagnosing motor disorders in the sphincter of Oddi and is helpful in deciding to perform endoscopic sphincterotomy.

Aged↗
PubMed1989

Existence and expression of photoreactivation repair genes in various yeast species.

Photoreactivation repair (Phr) activities in cell extracts of 13 different yeast species were measured by the Haemophilus influenzae transformation assay. Five species including Schizosaccharomyces pombe showed no or low enzymatic activity. In contrast to the other species, chromosomal DNAs of these 5 species did not show detectable hybridization using a DNA fragment of the photolyase PHR1 gene of Saccharomyces cervisiae as a probe even at a low stringency condition. When the PHR1 gene was attached to the 5'-flanking sequence of the iso-1-cytochrome c (CYC-1) gene of S. cerevisiae and introduced into S. pombe cells, the transformants acquired a high Phr activity, indicating that the PHR1 gene alone can provide a Phr-negative species with this repair activity and the light-absorbing cofactor(s) must be present in S. pombe. Our results also demonstrated that the 5'-flanking sequence of the S. cerevisiae CYC-1 gene works in S. pombe as a regulatory element.

DNA Probes↗
PubMed1989

Molecular cloning of rat type 2C (IA) protein phosphatase mRNA.

A full-length cDNA encoding rat type 2C (IA) protein phosphatase was isolated from a kidney cDNA library. The cDNA was identified by screening the library with oligonucleotides based on a partial amino acid sequence determined from purified rat liver phosphatase. This clone is 2.35 kilobase pairs long and has a single extended translation reading frame that predicts a 382-amino acid protein of 42,416 daltons. The deduced amino acid sequence contains segments corresponding to three peptides from rat liver type 2C protein phosphatase and two peptides from rabbit skeletal muscle type 2C phosphatase. Rat kidney type 2C protein phosphatase is distantly related to yeast adenylate cyclase but is not related to the catalytic subunits of two other protein phosphatases (types 1 and 2A).

Adenylyl Cyclases↗
PubMed1989

Expression of an Anacystis nidulans photolyase gene in Escherichia coli; functional complementation and modified action spectrum of photoreactivation.

The Anacystis nidulans photolyase gene inserted in an expression vector plasmid was introduced into Escherichia coli cells and the production of Anacystis photolyase protein was confirmed by reaction with antibodies raised against photolyase purified from A. nidulans cells. The Anacystis photolyase functioned in photoreactivation repair defective E. coli cells. The E. coli transformants exhibited an action spectrum with a maximum around 380 nm similar to that of E. coli photolyase in contrast with the action spectrum of A. nidulans cells which has a maximum at 437 nm. These results indicate that the Anacystis photolyase produced in E. coli cells has enzymatic activity in spite of the apparent lack of its intrinsic 8-hydroxy-5-deazaflavin cofactor.

Base Sequence↗
PubMed1989

Tandem arrangement of photolyase and superoxide dismutase genes in Halobacterium halobium.

A DNA fragment containing the photolyase gene was cloned from Halobacterium halobium. The deduced amino acid sequence is highly similar to those of four known photolyases from eubacteria and a eucaryote. The cloned gene expressed in Escherichia coli increased the survival of UV-irradiated host cells by photoreactivation. These results indicate that photolyases of eucaryotes, eubacteria, and archaebacteria are derived from a common origin. In this cloned DNA fragment, two additional open reading frames (ORFs), ORF 151 and ORF 200, were found in the 5' and 3' adjacent flanking regions of the photolyase gene. ORF 200 shows unequivocal amino acid sequence homology to all known manganese and iron superoxide dismutases. Northern (RNA) hybridization analysis of H. halobium RNA revealed the existence of three transcripts, one of which covered all three ORFs, indicating that photolyase and superoxide dismutase are partly cotranscribed in this bacterium.

Amino Acid Sequence↗
PubMed1989

[Possibility of performing a modified operation on the depressed type early gastric carcinoma].

To study of the possibility of performing a modified operation in cases of a depressed early gastric carcinoma, we have investigated the possibility of stage I early gastric carcinoma detection. Examined were 196 cases of depressed early gastric carcinomas out of a total of 394 cases of a depressed gastric carcinoma. Further, the relationship between lymph node metastasis and the clinicopathological indicators was the following: 1) the macroscopical type grade was simple IIc; 2) the size of tumor was less than 50 mm; 3) the ulceration in the cancerous lesion was under (a) shallow Ul-II; and 4) the depressed floor showed a granular pattern. According to these indicators, we feel that it is possible to detect stage I early depressed carcinoma prior to operation.

Gastrectomy↗
PubMed1988

Cloning and characterization of a photolyase gene from the cyanobacterium Anacystis nidulans.

A 2 kb fragment was isolated from an Anacystis nidulans genomic DNA library by hybridization with synthetic oligonucleotide probes derived from the N-terminal amino acid sequence of Anacystis photolyase. This fragment contains a 1452 bp-long open reading frame encoding a polypeptide of 484 amino acids (Mr 54475). Antibodies raised against purified Anacystis photolyase reacted with extracts of cells harboring fused genes between lacZ of Escherichia coli and this gene. A 40.7% similarity was found between the deduced amino acid sequences of Anacystis and E. coli photolyases, notwithstanding the difference in chromophore structure.

Amino Acid Sequence↗
PubMed1988

Value of percutaneous transhepatic cholangioscopy (PTCS).

Since July 1975, percutaneous transhepatic biliary drainage (PTBD) has been performed in 533 cases, and since April 1977 we have developed percutaneous transhepatic cholangioscopy (PTCS) as a diagnostic and therapeutic endoscopical tool in 198 cases of malignant disease and 195 benign cases. After dilating the sinus tract of PTBD using a 15-Fr catheter about 2 weeks after PTBD, PTCS was carried out through the sinus tract. PTCS has diagnostic advantages: the lesion can be accurately diagnosed histologically and the extent of cancer in the biliary tract can be assessed by taking biopsy specimens before the operation. PTCS has been applied for cholangioscopic lithotripsy in 145 cases of gallstone disease. In 44 cases, the Nd-YAG laser and/or electrohydraulic shock wave has been used to break up the stones. The PTCS morbidity was 6% and mortality was 0.3%.

Biliary Tract Diseases↗
PubMed1988

Isolation and sequence determination of the chicken rhodopsin gene.

A chicken genomic library was screened with a bovine opsin cDNA probe. A clone isolated under high stringency hybridization conditions contained DNA sequences highly homologous to all of the five exons of bovine and human opsin genes. Sequence comparison of the putative open reading frame in the chicken DNA fragment of 4.3 kb with bovine opsin cDNA revealed 82% identity for the nucleotide and 87% for the deduced amino acid sequence, indicating that this DNA fragment contains the complete chicken opsin gene. The position of four introns and amino acid sequences at all putative cytoplasmic loops are exactly conserved in chicken and mammals.

Animals↗
PubMed1988

Feedback regulation of basal pancreatic secretion in humans.

The effect of intrajejunal infusion of pancreatic juice on basal pancreatic secretion was studied in patients who had received pancreatoduodenectomy for pancreatic, biliary, or duodenal malignancy. Pure pancreatic juice was obtained through a drainage tube inserted into the main pancreatic duct. There was little fibrosis in the pancreatic remnant and daily pancreatic juice output was more than 200 ml. After intraluminal infusion of pancreatic juice, water, protein, bicarbonate, and enzyme outputs were decreased significantly by about 30%. Intraluminal trypsin also reduced pancreatic secretion. Trypsin inhibitor (aprotinin) suppressed the significant decrease caused by autopancreatic juice or trypsin solution. We conclude that basal pancreatic secretion in humans is under negative feedback control by intestinal pancreatic juice or tryptic activity.

Adult↗
PubMed1987

Corelease of PHI and VIP by vagal stimulation in the dog.

Electrical vagal stimulation increased immunoreactive peptide histidine isoleucine (IR-PHI) and vasoactive intestinal polypeptide (IR-VIP) levels in the portal plasma in anesthetized dogs, depending on the stimulation frequency. Atropine failed to suppress the vagal release of IR-PHI and IR-VIP, whereas hexamethonium abolished the increase of both peptide immunoreactivities. Gel filtration profiles of IR-PHI and IR-VIP in the portal plasma obtained during vagal stimulation revealed major peaks of IR-PHI and IR-VIP eluting in the same positions as synthetic PHI-27 and VIP-28, respectively. These data demonstrate that PHI and VIP are coreleased by vagal stimulation via a nicotinic ganglionic mechanism. An additional peak of larger molecular weight IR-PHI was observed in gel filtration of the portal plasma obtained under higher frequency vagal stimulation, when measured by the N-terminal-specific PHI antiserum. The presence of this larger form of IR-PHI together with a PHI-27-like component was also demonstrated in tissue extracts of the entire length of the gastrointestine, particularly in higher concentration in the stomach. The structure and the physiological significance of this larger form of IR-PHI remains to be elucidated.

Animals↗
PubMed1987

[Randomized comparison of continuous and intermittent oral administration of 5'-deoxy-5-fluorouridine in the treatment of advanced gastric cancer; a phase II trial by the Multi-institutional Cooperative Study Group].

To investigate the optimal dosage schedule for 5'-deoxy-5-fluorouridine (5'-DFUR), a randomized comparative study was performed in patients with inoperable or advanced gastric cancer. Eight hundred mg/m2/day of 5'-DFUR was administered in the continuous administration group, while in the intermittent administration group 1,400 mg/m2/day was given for 4 days followed by 3 days with no medication in a one-week cycle, making the total dose 5,600 mg/m2/week in both regimens. In both groups, 5'-DFUR was administered for more than 4 weeks. Overall response rate was 14.3% (3/21) for both administration methods. The response rate for the primary site was 9.5% (2/21) in the continuous administration group, and 14.3% (3/21) in the intermittent group. As to toxicity, the incidence of diarrhea was 26.7% in the continuous group and 4.2% in the intermittent group. Although there was no significant difference between these two dosage schedules in efficacy and toxicity, the lower incidence of diarrhea suggested the clinical usefulness of the intermittent administration method. This result emphasized the need to further studies to investigate the most appropriate dosage schedule for fluorinated pyrimidine derivatives.

Administration, Oral↗
PubMed1987

[Esophageal adenocarcinoma in an 81-year-old man].

Adenocarcinoma of the esophagus is relatively rare. An 81-year-old man with the chief complaints of loss of appetite and general fatigue was admitted to our hospital. By X-ray and endoscopic examination, a diagnosis of esophageal carcinoma in the Ei and Ea areas was made. A biopsy specimen obtained by endoscopy showed moderately differentiated adenocarcinoma, and the tumor origin was recognized in the cardia of the stomach. Lower esophagofundectomy by left thoracolaparotomy was performed. The postoperative pathological diagnosis showed adenocarcinoma of the esophagus and the tumor expansively invading to the cardiac portion.

Adenocarcinoma↗
PubMed1986

Molecular characterization of the human excision repair gene ERCC-1: cDNA cloning and amino acid homology with the yeast DNA repair gene RAD10.

The human excision repair gene ERCC-1 was cloned after DNA mediated gene transfer to the CHO mutant 43-3B, which is sensitive to ultraviolet light and mitomycin-C. We describe the cloning and sequence analysis of the ERCC-1 cDNA and partial characterization of the gene. ERCC-1 has a size of 15 kb and is located on human chromosome 19. The ERCC-1 precursor RNA is subject to alternative splicing of an internal 72 bp coding exon. Only the cDNA of the larger 1.1 kb transcript, encoding a protein of 297 amino acids, was able to confer resistance to ultraviolet light and mitomycin-C on 43-3B cells. Significant amino acid sequence homology was found between the ERCC-1 gene product and the yeast excision repair protein RAD10. The most homologous region displayed structural homology with DNA binding domains of various polypeptides.

Amino Acid Sequence↗
PubMed1986

Helodermin has a VIP-like effect upon canine blood flow.

The effect of helodermin on vascular physiology was studied in anesthetized dogs using a synthetic replicate of helodermin and helodermin related peptides. Intraarterial infusion of helodermin caused a dose-dependent increase in femoral blood flow. Helodermin was 16 times less potent than VIP and 5 times more potent than PHM (human PHI). The helodermin effect lasted significantly longer; the half-life of the helodermin effect was 6.5 times longer than VIP. Synthetic helodermin (Hd) N-terminal fragment Hd(1-27)NH2 retained substantial activity similar to the full helodermin molecule but the prolonged effect was lost. Hd(7-35) and Hd(22-35) were inactive in this system. Intravenous injection of synthetic helodermin produced prolonged systemic hypotension and tachycardia; and, similar to VIP, it increased the common carotid arterial blood flow while those of the superior mesenteric and femoral arteries were decreased. The results demonstrate the VIP-like vasodilating activity and cardiovascular effects of helodermin in anesthetized dogs.

Animals↗