Biomedical subjects

Y Katayose

Publications and source records attributed to Y Katayose.

41 records · Page 3Linked to original sources

PubMed1988

Two linear plasmid-like DNA elements simultaneously maintained in Pleurotus ostreatus.

Two linear plasmid-like DNA elements, designated pLP01 and pLP02, have been isolated from a strain of Pleurotus ostreatus, an edible basidiomycete. pLP01 (10.0 kb) and pLP02 (9.4 kb) were found in mitochondrial preparations of the fungus and appear to have 5' ends blocked by association of a protein. Proteinase K cleavability of the 5'-terminal protein of pLP01 was higher than that of pLP02, indicating that the terminal proteins of both plasmid-like elements are distinct from one another. pLP01 and pLP02 were estimated to be present to the extent of 1-2 copies each per mitochondrial genome equivalent. The two plasmid-like elements had no homology between them and also were not homologous with the mitochondrial and nuclear genomic DNAs of the fungus.

Basidiomycota↗

PubMed1986

Cloning of Lentinus edodes mitochondrial DNA fragment capable of autonomous replication in Saccharomyces cerevisiae.

Mitochondrial (mt) DNA of the higher basidiomycetes Lentinus edodes with a molecular weight of about 69 kb was partially digested with Sau3AI, cloned with plasmid YIp32 (a hybrid of pBR322 and the yeast leu2 gene) and analyzed for sequences capable of autonomous replication (ARSs) in the eukaryote Saccharomyces cerevisiae. One recombinant plasmid was isolated which contained 3.2 kb fragment of the mtDNA with ARS activity. This plasmid (named pSK52) exhibited a high-frequency yeast transformation and was found to be maintained within the cell as an extrachromosomal element. The stability and copy number properties of pSK52 were similar to those of the recombinant plasmid of YIp32 and S. cerevisiae mt-ARS constructed as a reference. Subcloning experiments were carried out to assess the localization of ARS on the above 3.2 kb fragment, revealing that the fragment contains at least two ARSs.

Basidiomycota↗

PubMedDate not supplied

Detection of perfusion areas of the gallbladder vein on computed tomography during arterial portography (CTAP)--the background for dual S4a.S5 hepatic subsegmentectomy in advanced gallbladder carcinoma.

BACKGROUND/AIMS: It has been speculated that the veins of the gallbladder join the intrahepatic portal veins supplying the Couinaud's S4a-S5. This has been the theoretical ground for the resection of these 2 hepatic subsegments in advanced gallbladder carcinoma. However, no consensus has been reached on this concept. METHODOLOGY: The current study describes the non-neoplastic perfusion defects in connection with the gallbladder bed in 100 consecutive hepatic CTAP (computed tomographies during arterial portography). The suitability of S4a and S5 subsegmentectomies of the liver for advanced gallbladder carcinoma was also investigated by examining CTAP images of the branches of the portal vein involved in the perfusion defect. RESULTS: Two types of gallbladder venous perfusion were observed: 1) sphenoid distribution from the gallbladder bed into the P4a (37%), P5 (52%) and P6 (3%), and 2) perfusion into the P4 (9%) or directly into the middle hepatic vein (9%) after communicating with the hepatic hilum at the dorsal side of S4. CONCLUSIONS: These results support liver resection at S4a and S5 as the surgical approach for cases of advanced gallbladder carcinoma.

Gallbladder↗

PubMedDate not supplied

Surgical treatment and postoperative outcomes for middle and lower bile duct carcinoma in Japan--experience of a single institute.

BACKGROUND/AIMS: Recently, the Japanese Classification on Cancer of the Biliary Tract was revised and adopted the new comprehensive staging that is similar to UICC's TNM classification. We should be paying close attention to the significance of newly defined extensive factors of carcinomas on the long-term prognosis. METHODOLOGY: The surgical outcome for 99 patients who underwent resected middle (Bm) and lower (Bi) bile duct carcinomas was reviewed in order to evaluate the suitability of the surgical procedures employed for their treatment, namely, standard pancreatoduodenectomy for Bi carcinoma and bile duct resection with D2 lymph node dissection for Bm carcinoma. RESULTS: The overall 5-year cumulative survival rate (operative death excluded) of Bm and Bi carcinoma patients was 37.4% and the 5-year survival rate of the patients in whom surgical curability (curA) was accomplished was 51.6%. Recently, a new prognostic factor, "t-category", which indicates the degree of pericholedochal neoplastic invasion was proposed in the 4th edition of the Japanese General Rules for Surgical and Pathological Studies on Cancer of the Biliary Tract. The 10-year survival rates by t-category were 49.1% (t1), 19.7% (t2), and 0% (t3 and t4) respectively. For Bm carcinoma, the patients undergoing bile duct resection under the condition of curA showed excellent prognoses. For Bi carcinoma, the patients fulfilling particular histological criteria, i.e., those concerning the histological depth of neoplastic invasion (m, fm, panc1a), duodenal involvement (du0, du1), vascular invasion (pv0), pericholedochal neoplastic invasion (t1), lymph node metastasis (n0), and comprehensive stage I, had good postoperative outcomes. Taking into account the fact that the metastatic rate of paragastric lymph nodes was 1.3%, the cases of panc0,1 should be operated by pylorus-preserving pancreatoduodenectomy. The overall 5-year survival rates including far-advanced cases were 39.9% in Bm carcinoma patients and 36.9% in Bi carcinoma patients. However, these postoperative outcomes are far from satisfactory. CONCLUSIONS: Therefore, we concluded that pancreatoduodenectomy and pylorus-preserving pancreatoduodenectomy with extended D3 lymphadenectomy combined with systematic multimodal therapy are indicated in each and every case of Bm and Bi carcinoma.

Bile Duct Neoplasms↗

PubMedDate not supplied

Fuel utilization and glucose hyperalimentation after liver resection.

Clinical studies and experiments in rats were carried out to elucidate changes in fuel utilization after hepatectomy. In addition, the effect of glucose hyperalimentation on energy metabolism in the liver remnant was studied. Respiratory quotient (RQ) and substrate oxidation rate for fat and glucose were evaluated by indirect calorimetry in eight patients who had undergone liver resection. Patients had a reduced nonprotein RQ of approximately 0.85 and a reduced ratio of glucose to fat oxidation of approximately 2.0 on the 1st and 2nd postoperative days. After 80% hepatectomy, rats received either 30 kcal.kg-1.day-1 (group 1) or 200 kcal.kg-1.day-1 (group 2) of glucose for 48 h. In both rat groups, hepatic mitochondrial ATP synthesis 12 and 24 h after hepatectomy was accelerated when palmitic acid was used as the substrate and suppressed when pyruvate was used compared with sham-operated groups. This suggests that the energy substrate of the remnant liver was principally fatty acids rather than glucose, which seems to occur also in humans. Hepatic energy charge was within normal limits in group 1 (0.862 +/- 0.008) but decreased significantly in group 2 (0.818 +/- 0.006, p < 0.01) 12 h after hepatectomy. An abundance of glucose in the early postoperative period therefore caused a hepatic energy derangement by suppressing endogenous fat oxidation. This suppression was corroborated by the findings of lower immunoreactive glucagon and nonesterified fatty acid concentration in group 2. Therefore, glucose hyperalimentation in the early postoperative period after liver resection is not recommended.

Adenosine Triphosphate↗