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Biomedical subjects

T Ohtani

Publications and source records attributed to T Ohtani.

At least 73 records · Page 4Linked to original sources
PubMed1997

Intraoperative ultrasonography versus cholangiography during laparoscopic cholecystectomy: a prospective comparative study.

BACKGROUND: The purpose of this study was to compare the functional utility of intraoperative ultrasonography (IOUS) and cholangiography (IOC) during a laparoscopic cholecystectomy for the treatment of gallstone disease. STUDY DESIGN: A prospective study comparing IOUS and IOC was carried out in 65 patients. Intraoperative ultrasonography was conducted first using a 7.5-MHz linear array probe. After IOUS, IOC was then conducted in all patients. The respective usefulness of IOUS and IOC in the identification of gallstones, detection of hepatobiliary structures, and demonstration of congenital anomalies was then compared. RESULTS: Intraoperative ultrasonography was successful in all 65 patients, and IOC was successful only in 54. The time required for IOUS was significantly shorter (p < 0.0001) than for IOC. Intraoperative ultrasonography imaged the hepatic ducts and their confluence, the common hepatic duct, the common bile duct, and the ampulla of Vater in 97, 100, 97, and 51% of cases, respectively. Intraoperative cholangiography, on the other hand, depicted these structures in 85, 89, 100, and 94% of cases, respectively. Intraoperative ultrasonography demonstrated the cystic duct and its confluence in 94% of cases. Biliary anomalies were identified by IOUS in 12 patients and by IOC in 13. Intraoperative ultrasonography could detect the hilar vascular structures in most patients and visualized anomalies of the hepatic arteries in 5 patients. In this series, 5 patients had choledocholithiasis. The sensitivities, specificities, positive and negative predictive values, and accuracies in identifying these bile duct stones were 80, 98, 80, 98, and 97% by IOUS, and 80, 97, 67, 98, and 95% by IOC, respectively. CONCLUSIONS: Intraoperative ultrasonography is superior to cholangiography with respect to its safety, shorter examination period, and ease of administration in all patients. In addition, IOUS is also better for identifying subtle anatomic detail. Intraoperative ultrasonography compares favorably with IOC in terms of utility in exploring bile ducts for stones. Intraoperative ultrasonography is an effective procedure for biliary exploration during a laparoscopic cholecystectomy.

Cholangiography↗
PubMed1997

Production of monoclonal antibody discriminating serological difference in Escherichia coli O9 and O9a polysaccharides.

A monoclonal antibody (mAb) with a unique antigenic specificity against Escherichia coli O9 was produced. The O9a mAb was reactive with a part of the strains in E. coli O9. The O9a mAb did not react with LPS from the E. coli O9 test strain Bi316-42. The distribution of the antigen defined by the O9a mAb in E. coli O9 was consistent with that of E. coli O9a present in E. coli O9 strains. The chemical structure of the repeating unit of the O-specific polysaccharide detected by the mAb was demonstrated to be a mannotetraose by two-dimensional nuclear magnetic resonance spectroscopy. It was confirmed that the mAb recognized E. coli O9a serotype in E. coli O9 serotype strains, suggesting that E. coli O9a serotype might be a dominant strain in E. coli O9.

Animals↗
PubMed1996

Molecular cloning and analysis of the dominant flocculation gene FLO8 from Saccharomyces cerevisiae.

A flocculation gene was cloned from a Saccharomyces cerevisiae ATCC60715 genomic library, known to contain the FLO8 gene, on the basis of its ability to confer a flocculation phenotype on a nonflocculent strain. From a total of 11 130 clones, four clones sharing the several restriction fragments were isolated, suggesting that these were derived from the same locus. The results of integration mapping and disruption of the cloned gene indicated that this gene was the FLO8 gene. After disruption of the FLO8 gene, the strain lost its ability to flocculate. The DNA sequence of the FLO8 gene was determined. This gene includes a 2187-bp open reading frame that encodes a 729-amino acid protein. Computer analysis indicated that the FLO8 gene has a significant degree of homology with a S. cerevisiae chromosome V DNA sequence, but no homology with the FLO1 gene. The hydrophobicity profile of the putative FLO8 gene product did not indicate the presence of any significantly hydrophobic regions. Southern analysis of the FLO8 gene present in various yeast strains indicated that the FLO8 gene is highly conserved in yeast strains having a variety of flocculation phenotypes and genotypes. Northern analysis revealed that the level of FLO1 gene transcription is dependent on the rate of transcription of the FLO8 gene. These results suggest that the FLO8 gene mediates flocculation via transcriptional activation of the FLO1 gene.

Amino Acid Sequence↗
PubMed1996

Colorectal carcinoma metastases to the liver. Does primary tumor location affect its lobar distribution?

BACKGROUND: There is considerable evidence that blood returning from different abdominal organs does not mix completely but maintains streamline flow in the portal vein. This study tested the hypothesis that the location of primary colorectal carcinoma affects the intrahepatic distribution of liver metastases according to streamline flow in the portal vein. METHODS: Eighty-five patients with histologically verified liver metastases from colorectal carcinoma underwent potentially curative hepatectomy. Primary tumor location was the right-sided colon in 18 patients and the left-sided colon in 67. The liver was divided into two lobes by Cantlie's line. RESULTS: A total of 195 metastatic deposits were resected: 135 in the right lobe and 60 in the left. In the right-sided colon carcinoma group, 29 deposits were in the right lobe and 3 in the left. In the left-sided colon carcinoma group, 106 deposits were in the right lobe and 57 in the left. The pattern of lobar distribution was significantly different in the two groups (P = 0.003). CONCLUSIONS: Right-sided colon cancers selectively involve the right lobe, while left-sided tumors involve the entire liver, considering the ratio of weights of the right to left lobe is 2:1. This difference suggests that primary tumor location affects the pattern of lobar distribution of colorectal carcinoma liver metastases according to streamline flow in the portal vein.

Carcinoma↗
PubMed1996

Carcinoma of the ampulla of Vater: is radical lymphadenectomy beneficial to patients with nodal disease?

This study was undertaken to evaluate the effectiveness of radical lymphadenectomy in ampullary cancer with nodal disease. Thirty-five patients underwent the Whipple procedure with radical lymphadenectomy. The location and number of positive nodes was characterized. Eighteen patients (51%) had positive nodes. Patients without nodal disease (pN0 group) had an actuarial 5-year survival rate of 81%. Seven patients with metastasis confined to the pancreaticoduodenal nodes had a 5-year survival rate of 67%, which was comparable for the pN0 group (N.S.) and better than the 27% 5-year survival rate in patients with positive superior mesenteric nodes (P<0.05). Eleven patients with one to three positive nodes had a 5-year survival rate of 71%, which was also comparable to the pN0 group (N.S.) and better than the 0% 5-year survival rate in patients with four or more positive nodes (P<0.01). Radical lymphadenectomy is effective against a limited degree of nodal disease.

Actuarial Analysis↗
PubMed1996

Low-temperature resistance of higher plants is significantly enhanced by a nonspecific cyanobacterial desaturase.

A broad-specificity delta 9 desaturase gene was cloned from the cyanobacterium Anacystis nidulans. The enzyme introduces a cis-double bond at the delta 9 position of both 16 and 18 carbon saturated fatty acids linked to many kinds of membrane lipids. The gene was stably introduced into tobacco plants under transcriptional control of the cauliflower mosaic virus 35S promoter, and the enzyme was targeted into plastids by the transit peptide of the pea RuBisCO small subunit. The transgenic plants had a highly reduced level of saturated fatty acid content in most membrane lipids and exhibited a significant increase in chilling resistance.

Adaptation, Physiological↗
PubMed1996

Junction of the cystic duct with the left hepatic duct: report of a case discovered during laparoscopic cholecystectomy.

We report a case of an anomalous junction of the cystic duct with the left hepatic duct found during laparoscopic cholecystectomy. Only five other patients with this anatomy have been reported. Two of these five patients had left-sided gallbladders, and the remaining patients (including ours) had their gallbladder in its normal location. Although the prevalence of this anomaly associated with left-sided gallbladders is 5.6 to 14.3%, this anomaly appears to be quite rare in patients with gallbladders in the normal position. In four cases, it was accompanied by left-sided gallbladder or low bifurcation of the common hepatic duct. This rare condition may accompany other biliary anomalies and should be kept in mind when performing cholecystectomy.

Bile Duct Diseases↗
PubMed1995

Canthaxanthin biosynthesis by the conversion of methylene to keto groups in a hydrocarbon beta-carotene by a single gene.

Compounds that include (a) keto group(s) in a molecule are ubiquitous natural components. A novel gene involved in ketocompound biosynthesis, designated crtW, was isolated from the marine bacteria Agrobacterium aurantiacum and Alcaligenes PC-1 that produce ketocarotenoids such as astaxanthin. When this gene was introduced into Escherichia coli that accumulated beta-carotene due to the Erwinia carotenogenic genes, the E. coli transformants synthesized canthaxanthin, one of ketocarotenoids, which was identified after purification by its visible, FD-MS and 1H-NMR spectral analysis. It has been demonstrated for the first time that one gene encodes an enzyme "ketolase" that catalyzes the conversion of methylene groups of a hydrocarbon beta-carotene to keto groups for synthesizing canthaxanthin via echinenone.

Alcaligenes↗
PubMed1995

Hepatic metastases from carcinoma of the gallbladder.

BACKGROUND: The optimal hepatic resection margin for gallbladder cancer (GBC) is still debated. To explore this issue, the authors analyzed the mode of hepatic spread of GBC. METHODS: Of 85 patients undergoing radical cholecystectomy, 20 had hepatic metastases. The pattern of hepatic metastasis was examined grossly and histologically in specimens. RESULTS: Twelve patients had evidence of microscopic angiolymphatic portal tract invasion, with or without direct liver invasion. Four had direct invasion alone, and three had distant hepatic metastatic nodules. The distance (y axis) between the farthest angiolymphatic lesion and primary tumor (mm) correlated significantly with the gross depth (x axis) of direct invasion (mm): y = 1.3 + 0.33x (r = 0.88, P < 0.01). Three patients with metastatic nodules died of blood-borne disease within a year. Eight of the others obtained either long-term palliation or cure after potentially curative resection. Lymph node metastases were detected in 90% of patients. CONCLUSIONS: The extent of microscopic angiolymphatic portal tract invasion correlates well with the gross depth of direct invasion of the liver. This correlation may be useful for estimating adequate hepatectomy margins. A hepatectomy with an adequate margin combined with a radical lymphadenectomy provides benefit for selected patients with hepatic metastases.

Aged↗
PubMed1995

Isolation and functional identification of a novel cDNA for astaxanthin biosynthesis from Haematococcus pluvialis, and astaxanthin synthesis in Escherichia coli.

We succeeded in isolating a novel cDNA involved in astaxanthin biosynthesis from the green alga Haematococcus pluvialis, by an expression cloning method using an Escherichia coli transformant as a host that synthesizes beta-carotene due to the Erwinia uredovora carotenoid biosynthesis genes. The cloned cDNA was shown to encode a novel enzyme, beta-carotene ketolase (beta-carotene oxygenase), which converted beta-carotene to canthaxanthin via echinenone, through chromatographic and spectroscopic analysis of the pigments accumulated in an E. coli transformant. This indicates that the encoded enzyme is responsible for the direct conversion of methylene to keto groups, a mechanism that usually requires two different enzymatic reactions proceeding via a hydroxy intermediate. Northern blot analysis showed that the mRNA was synthesized only in the cyst cells of H. pluvialis. E. coli carrying the H. pluvialis cDNA and the E. uredovora genes required for zeaxanthin biosynthesis was also found to synthesize astaxanthin (3S, 3'S), which was identified after purification by a variety of spectroscopic methods.

Amino Acid Sequence↗
PubMed1995

Blunt pancreatic trauma with main pancreatic duct disruption managed successfully with total parenteral nutrition: report of a case.

Although surgery is the usual treatment of choice for pancreatic trauma with disruption of the main pancreatic duct, we report herein the case of a patient in whom blunt pancreatic trauma with disruption of the proximal main pancreatic duct was successfully managed by conservative treatment. An 18-year-old women presented with abdominal pain 22 days after being involved in a car accident in which her upper abdomen was thrust against the steering wheel. Computed tomography revealed a pancreatic pseudocyst and a prevertebral pancreatic fracture, and endoscopic retrograde pancreatography showed complete disruption of the main pancreatic duct at the neck. Considering that the patient had been clinically stable since the accident, we elected to continue with conservative management and placed her on total parenteral nutrition. Rapid recovery followed and 6 years later, the patient remains well without any exocrine or endocrine insufficiency despite atrophy of the distal pancreas. This experience indicates that selected cases of main pancreatic duct disruption following blunt trauma may be amenable to conservative management.

Adolescent↗
PubMed1995

Focal dermal hypoplasia (Goltz syndrome) associated with multiple giant papillomas.

We report a case of focal dermal hypoplasia (FDH) with multiple giant papillomas on nonperimucosal areas. The patient had had cribriform hyperpigmented and depigmented plaques on the trunk and extremities since birth. There were also hypoplastic skin lesions on the right arm, left elbow and right thigh. The multiple giant papillomas began to appear, when she was 22 years old, on the trunk and extremities. Cryotherapy was effective in controlling them.

Adult↗
PubMed1995

Structure and functional analysis of a marine bacterial carotenoid biosynthesis gene cluster and astaxanthin biosynthetic pathway proposed at the gene level.

A carotenoid biosynthesis gene cluster for the production of astaxanthin was isolated from the marine bacterium Agrobacterium aurantiacum. This cluster contained five carotenogenic genes with the same orientation, which were designated crtW, crtZ, crtY, crtI, and crtB. The stop codons of individual crt genes except for crtB overlapped the start codons of the following crt genes. Escherichia coli transformants carrying the Erwinia uredovora carotenoid biosynthesis genes provide suitable substrates for carotenoid biosynthesis. The functions of the five crt genes of A. aurantiacum were determined through chromatographic and spectroscopic analyses of the pigments accumulated in some E. coli transformants carrying various combinations of the E. uredovora and A. aurantiacum carotenogenic genes. As a result, the astaxanthin biosynthetic pathway is proposed for the first time at the level of the biosynthesis genes. The crtW and crtZ gene products, which mediated the oxygenation reactions from beta-carotene to astaxanthin, were found to have low substrate specificity. This allowed the production of many presumed intermediates of astaxanthin, i.e., adonixanthin, phoenicoxanthin (adonirubin), canthaxanthin, 3'-hydroxyechinenone, and 3-hydroxyechinenone.

Amino Acid Sequence↗