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Biomedical subjects

A Yasui

Publications and source records attributed to A Yasui.

At least 73 records · Page 4Linked to original sources
PubMed1994

A new method of anterior mediastinal tracheostomy following resection of cervical esophagus and the larynx: report of a case.

We report herein the case of a 52-year-old man for whom a split pectoralis major myocutaneous flap was applied at the time of extended radical surgery for esophageal carcinoma with tracheal involvement, to avoid the postoperative complications of anterior tracheostomy such as tracheal necrosis and rupture of the major vessels. Laryngopharyngectomy and extended resection of the proximal trachea was performed through a manubrectomy, leaving the tracheal remnant only 4 cm above the carina. A pectoralis major myocutaneous flap was split into two with one piece being wrapped around the trachea at the anterior mediastinal tracheostomy site, and the other being placed between the trachea and brachiocephalic artery. The postoperative course was uneventful and the patient was discharged from hospital on the 34th postoperative day. A split pectoralis major myocutaneous flap may be effective not only for filling the dead space between the trachea and brachiocephalic artery, but also for reducing tension at the tracheocutaneous anastomosis and protecting against circulatory damage at the mediastinal tracheostomy site to minimize stomal retraction.

Carcinoma, Squamous Cell↗
PubMed1994

Sphincter of Oddi motility in patients with bile duct stones. A comparative study using percutaneous transhepatic manometry.

The motility of the sphincter of Oddi was measured by percutaneous transhepatic manometry of the sphincter of Oddi (PTMSO) in three groups of 57 patients with bile duct stones. The three groups were: (1) cholecystectomy group (N = 10)--patients with common bile duct stones (CBDS) who had already undergone cholecystectomy; (2) noncholecystectomy group (N = 37)--patients with CBDS who had not undergone cholecystectomy; and (3) intrahepatic stone (IHS) group (N = 10). The basal pressure, amplitude, frequency, and propagation direction of contraction waves and the response to cerulein injection or dried egg yolk ingestion were analyzed and compared among these groups. No significant differences in the basal pressure, amplitude, frequency, and propagation direction of the contraction waves were found among the three groups. There were also no differences in the response to cerulein or dried egg yolk ingestion. The frequency and duration of the burst contractions occurring in duodenal phase III of the migrating motor complex were significantly higher (P < 0.05) in the cholecystectomy group than in the other two groups. These two differences in the burst contractions may be ascribed to the absence of the gallbladder.

Adult↗
PubMed1994

DNA photolyase from the fungus Neurospora crassa. Purification, characterization and comparison with other photolyases.

A phr-gene from the filamentous fungus Neurospora crassa was overexpressed in Escherichia coli cells, yielding a biologically active photolyase. After purification till apparent homogeneity, the 66 kDa protein was found to contain equimolar amounts of 5,10-methenyltetrahydrofolic acid (MTHF) and FAD, classifying it as an MTHF-type photolyase. Compared to other MTHF photolyases the absorption maximum of Neurospora photolyase is shifted from ca 380 nm to 391 nm (epsilon = 34,800), while an additional shoulder is present at 465 nm. In dark-adapted enzyme the FAD chromophore is predominantly present in the oxidized form, in contrast with E. coli and Saccharomyces cerevisiae photolyase, which contain mainly semiquinone or fully reduced FAD, respectively. Preillumination or dithionite treatment converted oxidized FAD in Neurospora photolyase into the fully reduced form, with a concomitant shift of the absorption maximum from 391 to 396 nm and disappearance of the 465 nm shoulder. The action spectrum of photoreactivation coincides with the absorption spectrum of preilluminated (reduced) photolyase, extending the spectral region of MTHF-type photolyases from 380 till 396 nm. A quantum yield of 0.57 was obtained for the overall repair reaction. Comparison of spectral properties of FAD in Neurospora photolyase and the model compound lumiflavin points to an apolar microenvironment of photolyase-bound FAD. Neurospora photolyase has distinct advantages over E. coli photolyase as it is more stable and contains a full complement of chromophores.

Deoxyribodipyrimidine Photo-Lyase↗
PubMed1994

The effect of epidural morphine on human intestinal motility in the early postoperative period.

The early postoperative recovery of intestinal motility and the response of motility to epidural morphine were investigated in 20 patients. Periodic motor activities in the jejunum were recovered within 32 hours in all cases. The length of these cycles increased gradually from the 1st (23.2 min) to the 4th (41.7 min) postoperative day. Morphine and lignocaine were given through an epidural catheter. Morphine induced premature migrating motor complexes (MMC) in all cases, whereas lidocaine failed to evoke this response in every case. The mean duration (19.8 min) and maximal amplitude (62.8 mmHg) of the burst activities induced by morphine were significantly longer and higher than those occurring spontaneously (7.7 min and 35.6 mmHg, respectively). The intervals between the induced and the subsequent spontaneous contractions were the same as the intervals between spontaneous contractions. These observations indicate that epidural morphine induced premature MMC without interrupting recovery patterns from postoperative gastrointestinal paralysis.

Adult↗
PubMed1993

Molecular cloning and expression of cDNA encoding rat skeletal muscle cytosolic sialidase.

We have isolated a cDNA clone encoding the cytosolic sialidase of rat skeletal muscle. Degenerate oligonucleotides, based on amino acid sequence data for the purified enzyme, were used as primers to amplify fragments of the gene from rat skeletal muscle cDNA by the polymerase chain reaction. The amplified cDNA fragment was then applied as probe to screen a rat skeletal muscle cDNA library. The longest cDNA clone thus isolated was incomplete at the 5'-end, and therefore an amplified cDNA from the 5'-end portion of the gene was further generated by polymerase chain reaction. These two cDNAs were used to construct a cDNA encoding the entire sequence of rat sialidase. The composite sequence encodes an open reading frame of 379 amino acids that include all sequenced peptides. Although the deduced amino acid sequence is not largely similar to those of bacterial and parasite sialidases, it contains two Asp blocks, the conserved sequence of the sialidases from these microorganisms. When the cDNA was inserted into an expression vector followed by transformation in Escherichia coli, sialidase activity appeared in the cell extract. The sialidase could be completely immunoprecipitated by antiserum against the cytosolic sialidase of rat skeletal muscle.

Amino Acid Sequence↗
PubMed1993

Crystallization and preliminary X-ray diffraction studies of photolyase (photoreactivating enzyme) from the cyanobacterium Anacystis nidulans.

Photolyase (photoreactivating enzyme) from the cyanobacterium Anacystis nidulans was crystallized by the hanging drop vapor diffusion procedure using ammonium sulfate as a precipitant. The pale-yellow crystals were grown to a size of 0.4 mm in length and 0.1 mm in diameter. They belong to the tetragonal space group P4(1)2(1)2 or P4(3)2(1)2 with unit cell dimensions of a = b = 90.7 A and c = 135 A. Assuming that the asymmetric unit contains one molecule, the Vm value is calculated as 2.6 A3/dalton. The crystals are stable towards X-ray exposure and diffract beyond 2.5 A resolution.

Crystallization↗
PubMed1993

Precise mapping and molecular characterization of the MFT1 gene involved in import of a fusion protein into mitochondria in Saccharomyces cerevisiae.

Garrett et al. [Mol. Gen. Genet. 225 (1991) 483-491] recently reported that an Atp2-lacZ fusion protein was transported into mitochondria in yeast, thus identifying the MFT1 (mitochondrial fusion targeting) gene as a genomic fragment which complements a mutation (mft1) that failed in targeting a fusion protein into mitochondria. They mapped this gene to the ORF, which we have independently identified as a gene homologous to the cyc07 gene, which is expressed specifically in the S phase during the plant cell cycle. We have mapped the MFT1 gene precisely and found that this gene should correspond to the neighboring ORF, rather than the ORF they identified.

Amino Acid Sequence↗
PubMed1993

Identification of cellular defect in UVS1, a UV-sensitive Chinese hamster ovary mutant cell line.

UVS1 is an intermediately UV-sensitive Chinese hamster ovary mutant originally isolated by its hypersensitivity to an anticancer drug, 1-[(4-amino-2-methyl-5-pyrimidinyl)methyl]-3-(2-chloroethyl)-3-nitrosour ea hydrochloride. By cell fusion analysis, UVS1 complemented the UV sensitivity of the mouse lymphoma cell line US31 from the eighth complementation group of UV-sensitive rodent cell lines. By enzyme-linked immunosorbent assay we found that within 3 h after UV irradiation both pyrimidine dimers and (6-4)photoproducts in UVS1 were not removed from chromosomal DNA in UVS1 at all. Twenty-four h after UV irradiation the removal rate of (6-4)photoproducts was intermediate between CHO9, the parental cell line, and 43-3B, a UV-hypersensitive Chinese hamster ovary mutant of the complementation group 1, whereas the pyrimidine dimers in UVS1 were removed less efficiently as 43-3B. Alkaline elution assay showed that the incising activity to damaged DNA after UV irradiation of UVS1 was as low as that of 43-3B. The number of 1-[(4-amino-2-methyl-5-pyrimidinyl)methyl]-3-(2-chloroethyl)-3-nitrosour ea hydrochloride-induced DNA interstrand cross-links of UVS1 was almost equal to that of 43-3B and about 1.5 times more than that of CHO9, suggesting that the gene products defective in UVS1 and 43-3B are essential for the excision repair of DNA damages produced by 1-[(4-amino-2-methyl-5-pyrimidinyl)methyl]-3-(2-chloroethyl)-3-nitrosour ea hydrochloride.

Animals↗
PubMed1993

Evidence for a repair enzyme complex involving ERCC1 and complementing activities of ERCC4, ERCC11 and xeroderma pigmentosum group F.

Nucleotide excision repair (NER), one of the major cellular DNA repair systems, removes a wide range of lesions in a multi-enzyme reaction. In man, a NER defect due to a mutation in one of at least 11 distinct genes, can give rise to the inherited repair disorders xeroderma pigmentosum (XP), Cockayne's syndrome or PIBIDS, a photosensitive form of the brittle hair disease trichothiodystrophy. Laboratory-induced NER-deficient mutants of cultured rodent cells have been classified into 11 complementation groups (CGs). Some of these have been shown to correspond with human disorders. In cell-free extracts prepared from rodent CGs 1-5 and 11, but not in a mutant from CG6, we find an impaired repair of damage induced in plasmids by UV light and N-acetoxy-acetylaminofluorene. Complementation analysis in vitro of rodent CGs is accomplished by pairwise mixing of mutant extracts. The results show that mutants from groups 2, 3, 5 and XP-A can complement all other CGs tested. However, selective non-complementation in vitro was observed in mutual mixtures of groups 1, 4, 11 and XP-F, suggesting that the complementing activities involved somehow affect each other. Depletion of wild-type human extracts from ERCC1 protein using specific anti-ERCC1 antibodies concomitantly removed the correcting activities for groups 4, 11 and XP-F, but not those for the other CGs. Furthermore, we find that 33 kDa ERCC1 protein sediments as a high mol. wt species of approximately 120 kDa in a native glycerol gradient.(ABSTRACT TRUNCATED AT 250 WORDS)

Acetoxyacetylaminofluorene↗
PubMed1993

The usefulness of postoperative continuous epidural morphine in abdominal surgery.

The influence of continuous epidural morphine on the recovery course of intestinal activity, urinary function, and ambulation after surgery was studied in 40 patients who underwent either gastrectomy for gastric cancer or cholecystectomy for cholelithiasis. Compared with a control group of patients whose postoperative pain was managed by pentazocine or hydroxyzine as before, the length of time before passing flatus or faeces was significantly shortened in the morphine groups (P < 0.05). Following gastrectomy, the urinary catheter was able to be removed significantly earlier in the morphine group (P < 0.05) although there was no statistical difference between both cholecystectomy groups. The morphine group experienced no difficulty with postoperative ambulation and exercise, although the difference in time before ambulation between the two groups was not considered significant. The results of this study led us to conclude that the postoperative continuous epidural infusion of morphine would be more beneficial following major abdominal surgery than the conventionally used methods of administering postoperative analgesia.

Abdomen↗
PubMed1993

The significance of preoperative chemotherapy for early gastric carcinoma.

In order to achieve a complete prognosis for early gastric carcinoma, a greater effort must be made to improve its present treatment, considering the small percentage of patients who still die from recurrence despite the prompt initiation of surgery. Over the past 9 years, 26 patients with early gastric carcinoma have undergone surgical resection after receiving preoperative chemotherapy in the form of oral 5-FU or 5'-DFUR in our institute. The effectiveness of preoperative chemotherapy was evaluated by histopathological examination of the resected stomachs. Of a total of 24 patients with depressed type gastric cancer, 19 were histologically found to have a cancerless area within the cancerous lesion, 8 of whom were classified as being over Grade 1b. Gross changes were observed in 13 of these 24 patients. The frequency of multiple early gastric cancer occurring in patients who had not received chemotherapy was 11.6%, whereas in those who had received chemotherapy it was 3.8%. The findings of this study thus indicate that preoperative chemotherapy is useful for reducing minute cancer foci and microscopic metastatic lesions.

Adult↗
PubMed1993

Expression of biologically active C3a as fusion proteins.

We selected three kinds of plasmids for expression of C3a as fusion proteins. The proteins were purified by affinity chromatography using the respective specific resins, and their activities were measured by guinea pig platelet aggregation. We showed that polyhistidine (polyHis)-C3a fusion protein was able to exhibit 30% of the activity of natural C3a. However, glutathione S-transferase (GST)-C3a fusion protein exhibited only 10% of such activity, and no activity was measured for maltose binding protein (MBP)-C3a fusion protein. The purified polyHis-C3a fusion protein was attached to the Ni-NTA agarose column in an attempt to isolate the C3a receptor from guinea pig platelets. The C3a binding protein isolated from digitonin-solubilized guinea pig platelet membrane was approximately 50 kDa on SDS-polyacrylamide gel. This is the first report of C3a fusion protein production with biological activity.

Adenosine Triphosphate↗
PubMed1992

Visible light-inducible photolyase gene from the goldfish Carassius auratus.

By introducing and expressing a cDNA library constructed from mRNA of the cultured goldfish Carassius auratus cells in Escherichia coli, a gene encoding photolyase of the vertebrate was isolated, the first example from metazoa. The amino acid sequence deduced from the nucleotide sequence differs significantly from those of microorganisms. Five out of 6 tryptophan residues strictly conserved in photolyases from microorganisms and thought to play important roles in DNA and chromophore binding of the enzyme are substituted by other residues of different characteristics. By Northern analysis the expression of the photolyase gene was found to be induced more than 10 times by exposure of the cells to visible light. These results indicate a unique evolution of the photolyase gene and a novel mechanism of gene regulation, in which visible light triggers the production of the light-dependent enzyme for repair of DNA damages induced by harmful ultraviolet part of sunlight.

Amino Acid Sequence↗
PubMed1992

Identification of the eleventh complementation group of UV-sensitive excision repair-defective rodent mutants.

The drug-sensitive mutant UVS1, isolated from the Chinese hamster cell line CHO9, was previously found to complement the UV sensitivity of the excision repair-defective rodent mutants representative of groups 1 to 8 (Hata et al., Cancer Res., 51: 195-198, 1991; M. Numata et al., personal communication). Recently two new complementation groups of UV-sensitive CHO mutants, e.g., groups 9 and 10, have been identified (Stefanini et al., Cancer Res., 51: 3965-3971, 1991). In this paper we demonstrate that the repair defect in UVS1 cells is genetically different from those present in the mutants CHO7PV and CHO4PV, representing groups 9 and 10, respectively. Therefore, UVS1 represents a new complementation group of UV-sensitive rodent cell lines, the eleventh group.

Animals↗
PubMed1992

A gene family homologous to the S-phase specific gene in higher plants is essential for cell proliferation in Saccharomyces cerevisiae.

Previously we reported the isolation and characterization of the gene, cyc07, which was specifically expressed in the S phase during the cell cycle in synchronous cell division cultures of the higher plant, Catharanthus roseus. We found that the yeast Saccharomyces cerevisiae contains two closely related genes which show a high degree of similarity (about 64% at the amino acid level) to cyc07 of C. roseus. Site-directed disruption mutations demonstrated that the two yeast genes, homologous to cyc07, constitute an essential gene family for cell proliferation in yeast cells. Furthermore, the rate of cell proliferation varied with the gene copy number.

Amino Acid Sequence↗
PubMed1992

Paradoxical response to cerulein on sphincter of Oddi in the patient with gastrectomy.

Sphincter of Oddi motility was measured in 55 gallstone patients either through the sinus tract of percutaneous transhepatic biliary drainage or through the T tube. The influence of cholecystectomy and gastrectomy on the sphincter of Oddi was analyzed by comparing responses in patients with or without surgery to the administration of cerulein and the ingestion of dry egg yolk. When comparing cholecystectomized patients to nonsurgical subjects, cholecystectomy revealed no influence on the response to cerulein and feeding. Both groups showed relaxation of contraction waves after provocations. On the other hand, two thirds of the postgastrectomy patients showed an acceleration in the contractions of the sphincter of Oddi after provocations (one third showed no change), while all of the nongastrectomy group saw the disappearance of the wave after cerulein administration and 83% revealed complete suppression of the wave after feeding. It is suspected that this paradoxical response to CCK on the sphincter of Oddi is a lithogenic factor after gastrectomy.

Ceruletide↗
PubMed1992

Effect of duodenal switch procedure on gastric acid production, intragastric pH, gastric emptying, and gastrointestinal hormones.

The duodenal switch operation preserves the pylorus and the proximal 3 to 7 cm of duodenum in continuity with the stomach while diverting pancreaticobiliary secretions. We compared it with the Roux-en-Y without vagotomy or antrectomy in 12 dogs with innervated gastric pouches. Acid secretion was inhibited between tests using ranitidine in the Roux-en-Y group only, but two of the six dogs still developed stomal ulcers and the remainder showed stomal hyperemia. This may be due to a significant increase in gastric acid output after Roux-en-Y, but gastric emptying and plasma gastrin, cholecystokinin, secretin, gastric inhibitory polypeptide, peptide YY, and neurotensin were similar after both procedures. In 12 patients and a further 6 dogs, the duodenal switch caused no significant change in the intragastric pH environment as assessed by intragastric pH monitoring. The duodenal switch is a suitable procedure for pancreaticobiliary diversion.

Anastomosis, Roux-en-Y↗