Biomedical subjects

K Ouchi

Publications and source records attributed to K Ouchi.

At least 73 records · Page 4Linked to original sources

PubMed1994

The radiologic presentation of Osler-Weber-Rendu disease of the liver.

A case of Osler-Weber-Rendu disease with extensive hepatic arteriovenous fistulation is described in detail. Hemodynamic and imaging data indicated hepatic artery to hepatic vein shunting. Enhanced magnetic resonance imaging demonstrated the existence of arteriovenous fistulas by virtue of simultaneous enhancement of hepatic arteries and veins. Embolization treatment was not indicated because the patient was asymptomatic despite cardiac high output.

Arteriovenous Fistula↗

PubMed1993

Obstructive jaundice associated with extrahepatic portal vein obstruction: report of two cases.

We herein report two cases of obstructive jaundice with markedly dilated collateral veins either in or around the bile duct in the setting of extrahepatic portal vein obstruction (EHPO). In the first case, a proximal splenorenal shunt provided relief of biliary stenosis as well as eradication of esophageal varices due to a decompression of portal hypertension. This evidence proved that the markedly extended collateral veins in the hepatoduodenal ligament caused biliary stenosis by compressing the bile duct. In the second case, obstructive jaundice was probably caused by cholangitis and was relieved with biliary drainage. Portal decompressive surgery was not indicated because of the slight degree of esophageal varices. The relationship between cholangitis and EHPO in these patients calls for further investigation. In cases with EHPO manifesting obstructive jaundice associated with risky esophageal varices, portal decompressive surgery is recommended as the procedure of choice.

Adolescent↗

PubMed1993

Altered energy metabolism and oxidative injury following endotoxemia in rats with normal or cirrhotic livers.

The release of oxygen-derived free radicals has been implicated in endotoxin-mediated hepatic injury. The effect of hepatic lipid peroxidation on tissue energy reserves in the livers of normal and cirrhotic rats was studied following administration of E. coli endotoxin. Before endotoxin injection, the basal hepatic energy charge was lower and levels of hepatic malondialdehyde (MDA) and total glutathione (GSH) higher in cirrhotic rats than in normal rats. Virtually identical levels of blood endotoxin were obtained in the two groups 24 h after injection of LD50 doses of endotoxin (20 mg/kg and 1 mg/kg in normal and cirrhotic rats, respectively). Hepatic energy charge, tissue blood flow, GSH and glutathione peroxidase (GPX) were consistently or transiently decreased up to 24 h after the injection of endotoxin in both normal and cirrhotic rats. MDA, significantly increased in normal rats 1 h after injection of endotoxin, returned to normal levels 3-12 h after endotoxin administration, but was again elevated at 24 h. Cirrhotic rats did not show any significant change in MDA following endotoxin injection. In normal rats, endotoxin appears to trigger the liberation of free radicals accelerating depletion of hepatic energy reserves, over and above the effect of decreased hepatic blood flow. In contrast, increased lipid peroxidation was not detected in cirrhotic rats despite GSH and GPX consumption during endotoxemia (indicating oxygen radical generation). Cirrhotic livers were apparently protected against oxygen radical injury by higher levels of endogenous GSH and GPX. Reduced hepatic blood flow may be mainly responsible for the alteration in energy metabolism of the cirrhotic liver.

Animals↗

PubMed1993

Genetic transformation of industrial yeasts using an amino acid analog resistance gene as a directly selectable marker.

Prototrophic and often polyploid yeasts of industrial use require some dominant genes as directly selective markers for the transformation. We examined the applicability of a dominant gene, ARO4-OFP, which causes the resistance to PFP plus tyrosine, to direct selection of the transformants from 2 laboratory and 6 industrial strains, including bakers', distillers', winery, and saké yeasts. Although the transformation rates were low and seemed different among strains, the ARO4-OFP gene was applicable to all strains tested for direct selection of the transformants.

Biotechnology↗

PubMed1993

Recurrence of hepatocellular carcinoma in the liver remnant after hepatic resection.

We analyzed the results of 19 patients who had intrahepatic recurrence of hepatocellular carcinoma (HCC) among 47 patients who were discharged from the hospital after having a hepatic resection in order to evaluate the factors affecting recurrence and survival. Recurrence-free survival rates were 80%, 44%, and 28% at 1, 3, and 5 years, respectively. Of the 19 patients with recurrence, 14 had multiple lesions, and 16 of the recurrences were detected within 3 years of surgery. None of the following factors correlated with recurrence: hepatic function; tumor size; presence of tumor capsule; capsular invasion; vascular invasion and intrahepatic metastasis; extent of hepatic resection; and resection with tumor-free margins. Patients having multiple recurrent HCCs, however, had larger-sized tumors at the time of resection than those with a solitary recurrence. The survival rates after recurrence were significantly better in patients with a solitary recurrence, and these patients were treated with transcatheter arterial embolization (TAE) therapy. Early detection as well as TAE for recurrent HCCs is necessary to improve long-term survival.

Carcinoma, Hepatocellular↗

PubMed1993

Nosocomial outbreak of Pseudomonas cepacia respiratory infection in immunocompromised patients associated with contaminated nebulizer devices.

From May 1990 to August 1991, 36 patients admitted to the Department of Internal Medicine in a medical school hospital with hematological malignancies or solid tumors, developed respiratory tract colonization with Pseudomonas cepacia. Sixteen (44.4%) of these patients developed pneumonia, and four (11.1%) died of respiratory failure due to P. cepacia pneumonia. Extensive survey of the hospital environment as well as equipment showed that nebulizer devices used by the patients for inhalation were contaminated with P. cepacia. Phenotypic characteristics, (production of hemolysin and extracellular enzymes [lipase, lecithinase and protease]), the Analytical Profile Index 20 NE pattern, and the pattern of DNA fingerprinting by pulse-field gel electrophoresis in clinically isolated strains and strains derived from nebulizer devices were compared. The strains of P. cepacia obtained from patients in the Department of Internal Medicine were indistinguishable from each other and also from those isolated from nebulizer devices, but were different from those isolated from patients in other departments at the same time. These results demonstrated that the outbreak of P. cepacia respiratory colonization in immunocompromised patients was a nosocomial acquisition, and probably occurred by transmission through contaminated nebulizer devices.

Adolescent↗

PubMed1993

Clinical studies of oral quinolone once daily in the treatment of lower respiratory tract infections.

The efficacy and safety of oral ofloxacin, 400 mg once daily, for the treatment of patients with lower respiratory tract infections were studied. The most common species recovered from the sputum specimens of these patients were Haemophilus influenzae, followed by Streptococcus pneumoniae (S. pneumoniae), Staphylococcus aureus (S. aureus), Gram positive cocci unidentified, Pseudomonas aeruginosa (P. aeruginosa), Morexella catarrhalis, Streptococcus epidermidis, and another Haemophilus species in this order. All these bacteria were susceptible to ofloxacin except for one strain of methicillin resistant S. aureus. A satisfactory clinical outcome was achieved in 34 of 40 patients (85%). It is concluded that ofloxacin, 400 mg once daily, is useful for patients with respiratory tract infections.

Administration, Oral↗

PubMed1993

[Restriction endonuclease (NotI) analysis of chromosomal DNA of Helicobacter pylori by PFGE].

With the goal of differentiating H. pylori in order to clarify its pathogenicity, we have conducted a restriction endonuclease of the chromosomal DNA of 24 strains of H. pylori employing the restriction endonucleases, NotI, CPOI, KpnI, and SmaI using pulsed-field gel electrophoresis (PFGE). With NotI, these 16 strains out of 24 strains were completely digested, and 16 clearly different electrophoretic patterns of NotI digested chromosomal DNA fragments were seen, permitting us to successfully differentiate H. Pylori. We also estimated the genome size of each strain, ranging from 1326 to 2360 kilobases. Using this method, we confirmed our previously established nude mouse model of infection with H. pylori by demonstrating that the mice were infected with the H. pylori administered in this study. Thus, we have demonstrated the digested with NotI by PFGE is an effective method for differentiating H. pylori and estimating the size of DNA of H. pylori.

Adult↗

PubMed1993

[Effect of intra-venous hyperalimentation on hepatic energy metabolism after hepatic resection in the cirrhotic rat].

We evaluated experimentally the effect of administration of glucose on hepatic energy metabolism, mitochondrial functions and lipid metabolism after hepatic resection. The 75% hepatic resection was performed on thioacetamide induced cirrhotic rat. Glucose solution with 30 Cal/kg/day (group I) or 200 Cal/kg/day (group II) was administrated intravenously for 48 hours after hepatic resection. Blood levels of ketone bodies and glucagon, tissue activities of ATP synthesis and tissue content of adenine nucleotides were measured in both groups. Hepatic energy charge was significantly decreased in group II, comparing with group I. When fatty acid was used as a substrate for respiratory system, the activity of ATP synthesis on mitochondria after hepatic resection rose, while in case pyruvate was used as a substrate the value was declined. On the levels of serum free fatty acids and ketone bodies, there were no remarkable changes in group I, while in group II, obvious declines were investigated. It is suggested that the overload of glucose in the early stage after hepatic resection is unfavorable to hepatic energy metabolism because of decline of serum free fatty acid by hyperinsulinemia and suppression of fatty acid oxidation by decline of blood glucagon.

Animals↗

PubMed1993

Do recent advances in diagnosis and operative management improve the outcome of gallbladder carcinoma?

To study the effect of recent advances in diagnosis and operative management on survival of patients with gallbladder carcinoma, records of 26 patients who underwent resection between 1960 and 1978 (group 1) and 25 patients who underwent resection between 1979 and 1991 (group 2) were compared. The operative mortality rate was lower in group 2 (0%) than in group 1 (12%). The 5-year survival rate was higher in group 2 (60.8%) than in group 1 (30.4%; p < 0.01). Although preoperatively undiagnosed cases were not less in group 2 than in group 1, cases diagnosed with certainty before surgery were increased significantly and suspected cases of gallbladder carcinoma were decreased in group 2 (p < 0.05) as a result of recent advances in hepatobiliary imaging techniques. Twenty patients in group 2 (80%) and 13 in group 1 (50%) had tumors less than 30 mm in diameter (p < 0.05). Nine patients in group 2 (36%) had tumors at an early stage (tumors limited to mucosal or muscular layer), and only two (8%) in group 1 had early-stage tumors (p < 0.05). The incidence of curative resection was higher in group 2 (76%) than in group 1 (27%; p < 0.001). Earlier diagnosis and a higher chance of curative resection, together with improved surgical techniques, may contribute to the better survival seen in the recent 12-year period.

Adult↗

PubMed1992

Portal venous pressure following splenectomy in patients with portal hypertension of differing etiology.

To clarify the effect of splenomegaly on portal hemodynamics in patients with portal hypertension and esophageal varices, manometric studies were carried out before and after splenectomy during an operation for esophageal varices. The 118 patients evaluated retrospectively had underlying liver cirrhosis (LC) (62), idiopathic portal hypertension (IPH) (42), and extrahepatic portal occlusion (EHO) (14). The weight of the spleen did not differ significantly among the three diagnostic groups: 640 +/- 473.5 g for LC, 780 +/- 414.6 g for IPH, and 683 +/- 457.2 g for EHO. Before splenectomy, portal pressure was significantly elevated in the patients with EHO (410 +/- 85.2 mm H2O) as compared to either the LC or IPH groups (348 +/- 64.1 and 348 +/- 73.5 mm H2O). Following splenectomy the reduction of portal pressure was significantly greater in the EHO group (29 +/- 15.5%) than in either the LC (18 +/- 17.4%) or IPH (19 +/- 17.0%) groups. Each group was subdivided according to severity of splenomegaly: marked (spleen weight > or = 500 g) or slight (spleen weight < 500 g). Patients with LC and marked splenomegaly showed a reduction in liver function parameters as shown by the prolongation of indocyanine retention rate at 15 min as compared to those with slight splenomegaly. Though it is not statistically significant, the average portal pressure tended to be higher among those with marked splenomegaly.(ABSTRACT TRUNCATED AT 250 WORDS)

Esophageal and Gastric Varices↗

PubMed1991

Isolation and genetic study of p-fluoro-DL-phenylalanine-resistant mutants overproducing beta-phenethyl-alcohol in Saccharomyces cerevisiae.

p-Fluoro-DL-phenylalanine (PFP)-resistant mutants which produce a large amount of beta-phenethyl-alcohol, a rose-like flavor component, were isolated from the isogenic strains X2180-1A and X2180-1B of Saccharomyces cerevisiae. Cells of these mutants accumulated phenylalanine and tryptophan more than 3-fold times that of wild-type cells, while they accumulated less than half the tyrosine. The activity of prephenate dehydrogenase (PDG) (EC 1.3.1.12) was markedly decreased while that of 3-deoxy-D-arabino-heptulosonate-7-phosphate synthase (EC 4.1.2.15) was increased. Genetic analysis revealed that the mutation occurred at the TYR1 locus, encoding PDG, and that the mutated TYR1 gene, try1-pfp, caused both PFP resistance and beta-phenethyl-alcohol overproduction. This was supported by molecular genetic studies with cloned tyr1-pfp DNA.

Alleles↗

PubMed1991

A mutated ARO4 gene for feedback-resistant DAHP synthase which causes both o-fluoro-DL-phenylalanine resistance and beta-phenethyl-alcohol overproduction in Saccharomyces cerevisiae.

o-Fluoro-DL-phenylalanine (OFP)-resistant mutants which overproduce beta-phenethyl-alcohol were isolated from a laboratory strain of Saccharomyces cerevisiae. Cells of one of the mutants accumulated tyrosine and phenylalanine 1.5-3 fold more than did wild-type cells. Its 3-deoxy-D-arabino-hepturosonate-7-phosphate (DAHP) synthase (EC 4.1.2.15), encoded by ARO4, was free from feedback inhibition by tyrosine. Genetic analysis revealed that the mutation was controlled by a single dominant gene, ARO4-OFP, encoding feedback-resistant DAHP synthase by tyrosine, and that this gene caused both the OFP resistance and beta-phenethyl-alcohol overproduction. This was supported by molecular genetic studies using cloned ARO4 both from the wild-type and its mutant strain.

3-Deoxy-7-Phosphoheptulonate Synthase↗

PubMed1991

Energy metabolism changes and oxidative attack after hepatic arterial embolization and chemoembolization in thioacetamide-induced cirrhotic livers.

Hepatic energy metabolism and oxidative attack were studied after transcatheter arterial embolization (TAE) and chemoembolization (TAC) of the left and median lobes of the liver using thioacetamide (TAA)-induced cirrhotic rats. TAE was carried out using gelatin sponge (1.5 mg/cm3) dissolved in saline solution (SS). TAC was performed by adding mitomycin C (MMC) (1.6 mg/kg body weight) to the previous embolic solution. The energy charge (EC) of embolized lobes decreased from 0.86 to 0.78 and 0.74 1 h after TAE and TAC, respectively, but was restored 3 h later. Adenosine 5'-triphosphate (ATP) and total adenine nucleotide content (TAN) of embolized and non-embolized lobes was also temporarily decreased. Total hepatic blood flow (THBF) of embolized and chemoembolized lobes was reduced in almost 50%, and it took 1 week to become normalized. After TAC (3 and 6 h, respectively), total glutathione (TGSH) content was reduced from 7.02 mumol/g of liver to around 4.5 mumol/g, and malondialdehyde (MDA) content increased from 196.94 nmol/g of liver to values above 300 nmol/g. TAE in cirrhotic livers did not induce any changes in these parameters. In conclusion, after TAE and TAC the hepatic energy metabolism is temporarily altered by ischemia. TAC-induced oxidative attack, in addition to ischemia and MMC, could be one of the mechanisms explaining the effectiveness of this therapy.

Adenine Nucleotides↗

PubMed1991

Glucose overload and hepatic energy metabolism after resection of the cirrhotic liver in rats.

The effect of glucose hyperalimentation on energy metabolism in the cirrhotic rat liver after 70% hepatectomy was studied. After resection, rats received either 30 kcal/kg per day (group I) or 200 kcal/kg per day (group II) of glucose for 48 h. In both groups, hepatic mitochondrial ATP synthesis was accelerated when palmitic acid was used as substrate and suppressed when pyruvate was used. This suggests that the energy substrate of the remnant liver was principally fatty acids rather than glucose. Hepatic energy charge was within normal limits in group I, but decreased significantly in group II after hepatectomy. An abundance of glucose in the early postoperative period, therefore, caused a hepatic energy derangement by suppressing fatty acids utilization; this suppression was corroborated by the findings of lower immunoreactive glucagon and non-esterified fatty-acid concentrations in group II. To determine optimal glucose administration, the predicted value of glucose disposal rate (GDR) was calculated after an intravenous glucose tolerance test. GDR decreased significantly after hepatectomy and did not increase appreciably even with a large dose of insulin administration. These results suggest that glucose administration should be tailored to the GDR values after resection of the cirrhotic liver.

Adenosine Triphosphate↗

PubMed1991

Construction of a sucrose-fermenting bakers' yeast incapable of hydrolysing fructooligosaccharides.

Fructooligosaccharides stimulate the growth of intestinal bifidobacteria which are related to the favorable health and nutrition of humans and other animals. Since the efficient amount of fructooligosaccharide for an adult human is relatively large (about 5 g per day), its addition to daily foods like bakery goods might be beneficial. However, commercial Bakers' yeast hydrolyses fructooligosaccharides by the action of invertase encoded in SUC genes and ferments the resulting monosaccharides. According to the findings that strains carrying the MAL-constitutive gene and lacking the SUC gene fermented sucrose and not fructooligosaccharide, we constructed a sucrose-fermenting strain, YOY920, incapable of hydrolysing fructooligosaccharide, by cross-breeding a baking strain and a laboratory strain. In a molasses medium, the cell yield of YOY920 was comparable to that of a baking strain FSC6001, and much higher than that of the non-sucrose-fermenting strains. Although fructooligosaccharide inhibited the dough leavening ability of YOY920, white bread containing fructooligosaccharide could be produced in the defined dough formula using the new strain.

Animals↗

PubMed1991

Ultrastructure of neurofibrillary tangles in Alzheimer's disease by means of tilt-stage electron microscopy.

Neurofibrillary tangles (NFT) in the brains of patients with Alzheimer's disease were examined by means of tilt-stage electron microscopy. Observing a longitudinal direction, constricted parts of the NFT did not move in an axial direction. In a transverse section, a fibril of the NFT consisted of globular subunits having a hollow structure in the center and did not appear as paired filaments. From these findings, it was considered that a fibril of NFT consists of twisted protofilaments made up of globular subunits and does not consist of paired helical filaments.

Aged↗

PubMed1991

[Prevalence of antibodies to Chlamydia pneumoniae (strain TWAR) and other Chlamydia in Japan].

Chlamydia pneumoniae (Strain TWAR), the new third species of genus Chlamydia, is emerging as an important human respiratory pathogen in Western countries. However, little is known about it in Japan. In this study, 1330 serum samples were tested for seroprevalence of three species of genus Chlamydia including C. pneumoniae in Hiroshima. Microimmunofluorescence test was used to measure serum IgG antibody, and formalin fixed elementary bodies of C. trachomatis, C. psittaci, and C. pneumoniae were used as antigen. Serum titer of 1:32 or greater was considered positive. Seropositive rate of C. pneumoniae began to increase around the 6 month to 3 year old age group and reached 44% in the 8 to 11 year olds. A peak of seroprevalence according to age was around 20 year old, and about half of the adults were seropositive. Outpatients and healthy persons held almost the same seropositive rate. The positive rate in childhood was higher and the peak appeared earlier than some former studies in Western countries. The seropositive rate of C. trachomatis was noted 1-2% in the 6 month-7 year old age group, but no seropositive child was found in the 8-15 year olds. The rate was increased after adolescence and reached 10% in adults. The seroprevalence of C. psittaci was 1%. These data suggest C. pneumoniae is the most prevalent Chlamydia in Japan and as prevalent as in the Western countries.

Adolescent↗