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Biomedical subjects

Y Saitoh

Publications and source records attributed to Y Saitoh.

At least 307 records · Page 17Linked to original sources
PubMed1996

Effect of a parenteral nucleoside-nucleotide mixture on hepatic metabolism in partially hepatectomized cirrhotic rats.

After hepatectomy, purine and pyrimidine metabolism is a key process in synthesis of DNA and RNA and in energy metabolism. To supply nucleosides for salvage synthesis, nucleoside-nucleotide mixture solutions have been developed, and they have been found to improve protein metabolism and hepatic regeneration after partial hepatectomy in normal rats. However, the effect of the solution in cirrhotic liver, common in patients with hepatocellular carcinoma, has not been reported. The aim of this study was to evaluate the metabolic effect of the nucleoside-nucleotide mixture on cirrhotic rats after partial hepatectomy. Seventy percent partial hepatectomy was performed in thioacetamide-administered cirrhotic rats. The fractional protein synthetic rate, nitrogen balance, hepatic content of nucleic acid, and blood chemistry after the administration of the nucleoside-nucleotide mixture solution (OG-VI) with total parenteral nutrition was evaluated at 7 d after partial hepatectomy. OG-VI increased hepatic RNA level and hepatic fractional protein synthetic rate (p < 0.05). It is concluded that the nucleoside-nucleotide mixture solution is an effective nutritional supplement to the metabolism of cirrhotic rats after partial hepatectomy.

Animals↗
PubMed1996

Evidence for developmentally regulated transcriptional, translational and post-translational control of metallothionein gene expression in hair follicles.

The distribution of metallothionein (MT) and MT mRNAs was examined in hair (wool) follicles, where high levels of cell proliferation are found and where the resulting cells provide a temporal record of differentiation events. MT was found in the cytoplasm and some nuclei of follicle bulb cells of the proliferative zone, outer root sheath cells and in basal layer cells of sebaceous glands and sweat glands. The population of 5-bromo-2'-deoxyuridine (BrdU)+ cells in these tissues overlapped, but were not completely coincident with the distribution of MT staining. MT mRNA expression in hair (wool) follicles was assessed by in situ hybridization with four gene-specific sheep MT (sMT) isoforms. Intense signals were obtained with the sMT-Ib probe in follicle bulb cells from the proliferative zone to the keratogenous zone. Signals from the sMT-Ia probe were present in the same cells, but were much weaker. No signals were detected using the sMT-Ic and sMT-II gene-specific probes. The findings suggest that: (1) MT is important in cell proliferation and/or cell differentiation in the hair follicle bulb; (2) MT translation is inhibited during cell differentiation and migration; and (3) tissue-specific expression of uncharacterized sMT isoforms is likely.

Animals↗
PubMed1996

Activation of the osmo-sensitive chloride conductance involves P21rho and is accompanied by a transient reorganization of the F-actin cytoskeleton.

Hypo-osmotic stimulation of human Intestine 407 cells rapidly activated compensatory CL- and K+ conductances that limited excessive cell swelling and, finally, restored the original cell volume. Osmotic cell swelling was accompanied by a rapid and transient reorganization of the F-actin cytoskeleton, affecting both stress fibers as well as apical ruffles. In addition, an increase in total cellular F-actin was observed. Pretreatment of the cells with recombinant Clostridium botulinum C3 exoenzyme, but not with mutant enzyme (C3-E173Q) devoid of ADP-ribosyltransferase activity, greatly reduced the activation of the osmo-sensitive anion efflux, suggesting a role for the ras-related GTPase p21rho. In contrast, introducing dominant negative N17-p21rac into the cells did not affect the volume-sensitive efflux. Cell swelling-induced reorganization of F-actin coincided with a transient, C3 exoenzyme-sensitive tyrosine phosphorylation of p125 focal adhesion kinase (p125FAK) as well as with an increase in phosphatidylinositol-3-kinase (PtdIns-3-kinase) activity. Pretreatment of the cells with wortmannin, a specific inhibitor of PtdIns-3-kinase, largely inhibited the volume-sensitive ion efflux. Taken together, our results indicate the involvement of a p21rho signaling cascade and actin filaments in the activation of volume-sensitive chloride channels.

ADP Ribose Transferases↗
PubMed1996

Significant elevation of serum human hepatocyte growth factor levels in patients with acute pancreatitis.

Serum levels of human hepatocyte growth factor (HGF) were determined in 38 patients with acute pancreatitis by an enzyme-linked immunosorbent assay. The mean value of serum HGF levels on admission in the 38 patients was 1.69 +/- 0.40 (SEM) ng/ml. In 35 patients, serum HGF levels were found to be positive (> 0.39 ng/ml), with an incidence of 92.1%. In 17 patients, they were > 1.0 ng/ml, which was the cutoff value for fulminant hepatic failure. Serum HGF levels in the patients with severe acute pancreatitis (2.30 +/- 0.61 ng/ml; mean +/- SEM) were significantly higher than those in the patients with mild and moderate acute pancreatitis (0.63 +/- 0.06 ng/ml). Sixteen of seventeen patients whose serum HGF levels were > 1.0 ng/ml were evaluated as severe acute pancreatitis. Serum HGF levels were significantly elevated in the patients with higher Ranson scores, higher APACHE II scores, or higher computed tomography grades. Serum HGF levels in the patients with organ dysfunction (liver, kidney, or lung) were significantly higher than those in the patients without organ dysfunction. Moreover, serum HGF levels on admission in the nonsurvivors (3.17 +/- 1.30 ng/ml) were significantly higher than those in the survivors (1.22 +/- 0.33 ng/ml). The mortality rate of the patients showing serum HGF levels > 2.0 ng/ml on admission was 50%. In the patients with a lethal outcome, the mean serum HGF level remained constantly > 2.50 ng/ml during hospitalization. The serum HGF level reflected the clinical course of the disease rapidly and distinctly. Serum HGF levels increased with complications such as organ failure, infected pancreatic necrosis, and sepsis and decreased with successful intensive and surgical treatments. These results suggest that serum human HGF levels may reflect the severity, organ dysfunction, and prognosis in acute pancreatitis.

Acute Disease↗
PubMed1996

Recovery of adenosine triphosphate tissue levels of grafts preserved by the two-layer method after reperfusion.

Recovery of tissue adenosine triphosphate (ATP) levels after transplantation is very important for graft survival. We examined whether the pancreas grafts preserved by the two-layer method have the ability to synthesize ATP after reperfusion, and this is one of the mechanisms of action for the two-layer method in successful pancreas preservation. After preservation by the two-layer method using Euro-Collins' solution (EC) for 48 h (Group 1, n = 5) or simple cold storage in EC for 48 h (Group 2, n = 5), canine pancreas grafts were autotransplanted. In controls (Group 3, n = 5), canine pancreas grafts were autotransplanted without preservation. Graft viability was judged from graft survival after transplantation. Tissue adenine nucleotide concentrations were measured using high performance liquid chromatography after preservation, before reperfusion, and after 1 and 2 h of reperfusion. Graft survival rates were 5 of 5, 0 of 5, and 5 of 5, in Groups 1, 2, and 3, respectively. However ATP tissue levels in Group 1 were significantly higher compared with those in Group 2 after preservation and before reperfusion, respectively (10.95 +/- 1.52 vs. 2.75 +/- 0.33 and 2.90 +/- 0.51 vs. 2.03 +/- 0.68 mumol/g dry weight, p < 0.01 and p < 0.05, respectively). Total tissue adenine nucleotide levels in Group 1 before reperfusion were 7.41 +/- 1.47 mumol/g dry weight, and there was no significant difference compared with Group 2, 6.64 +/- 2.23 mumol/g dry weight. After reperfusion, there was no significant difference of ATP tissue levels between Groups 1 and 2 (4.07 +/- 1.18 vs. 4.48 +/- 1.32, not significant [NS]) after 1 h of reperfusion. However, after 2 h of reperfusion, tissue ATP levels in Group 1 (6.71 +/- 1.19 mumol/g dry weight) were significantly higher than were those in Group 2 (4.51 +/- 0.51 mumol/g dry weight, p < 0.01) and almost at the same levels as control (6.32 +/- 1.62 mumol/g dry weight). It was clear that recovery of ATP after reperfusion did not depend on the residual nucleotides pool but on the ability of the pancreas graft to synthesize ATP after reperfusion. We conclude that oxygenation of the pancreas graft during preservation by the two-layer method allows for ATP synthesis, which is essential in maintaining cellular integrity and leads to maintaining the graft's ability to synthesize ATP promptly after reperfusion. This is one of the mechanisms of action of the two-layer method in successful pancreas preservation.

Adenosine Triphosphate↗
PubMed1996

Isolation of methicillin-resistant coagulase-negative staphylococci from chickens.

Methicillin-resistant coagulase-negative staphylococci were isolated from the nares and skin of 1- to 8-week-old healthy chickens in three flocks from a farm. Isolation of methicillin-resistant coagulase-negative staphylococci was positive for 72 (25.7%) of the 280 chickens tested, with the frequency varying from 2.2 to 100% according to flock. A total of 45 appropriate isolates were selected and subjected to identification. Of the 45 methicillin-resistant coagulase-negative staphylococcal isolates selected, 37 were identified as Staphylococcus sciuri, 5 were identified as Staphylococcus epidermidis, and 3 were identified as Staphylococcus saprophyticus. The distribution of the species was different among the flocks. Comparative analysis of the SmaI-digested chromosomal DNA by pulsed-field gel electrophoresis revealed that the isolates could have originated from a single clone of each of S. sciuri and S. saprophyticus and three clones of S. epidermidis. By two methods based on the PCR technique, the mecA gene was detected in all five representative isolates of each methicillin-resistant coagulase-negative staphylococcal clone. The nucleotide sequence of a PCR fragment obtained from an isolate of S. sciuri was completely identical to the corresponding region of mecA genes reported in human methicillin-resistant Staphylococcus aureus isolates and Staphylococcus epidermidis isolates. The representative methicillin-resistant coagulase-negative staphylococcal isolates were resistant to many beta-lactam antibiotics, and some isolates were also resistant to macrolide and aminoglycoside antibiotics. This is the first evidence of the existence of methicillin-resistant coagulase-negative staphylococci from animals possessing the mecA gene.

Animals↗
PubMed1996

K-ras gene mutation in gall bladder carcinomas and dysplasia.

Epithelial dysplasia of gall bladder is an important precancerous lesion of gall bladder carcinogenesis. To investigate the frequency of K-ras gene mutation in gall bladder carcinoma and dysplasia, K-ras codon 12 mutations were investigated by the polymerase chain reaction/restriction enzyme based method following direct sequencing. Mutation was detected in 59% (30 of 51) of gall bladder carcinomas, in 73% (8 of 11) of gall bladder dysplasia in gall stone cases, and in 0% of the normal gall bladder epithelium. There was, however, no correlation between K-ras mutation and clinicopathological factors of gall bladder carcinoma. K-ras gene mutation occurs even in gall bladder dysplasia at an incidence similar to that in carcinomas, suggesting that testing for K-ras gene mutation may prove useful as an adjunct to bile cytological or biopsy analysis.

Base Sequence↗
PubMed1996

Airway wall dimensions during carbachol-induced bronchoconstriction in rabbits.

Airway wall area is an important determinant of airway narrowing. We hypothesized that in cross-sectioned peripheral airways, the wall area internal to the outer smooth muscle border (inner wall area) would decrease and the airway wall area external to the outer smooth muscle layer (adventitial area) would increase during bronchoconstriction because of the relocation of blood and/or fluid between these compartments. To test this hypothesis, we used anesthetized open-chest rabbits and measured airway wall dimensions and smooth muscle shortening of membranous airways after carbachol-induced bronchoconstriction using morphometric techniques. Acute (3-min) and sustained (40-min) bronchoconstriction was induced by aerosol nebulization of carbachol and compared with saline treatment. After physiological measurements, the heart base was snared, and the lung and heart were excised en bloc and frozen by using liquid nitrogen while a transpulmonary pressure of 2 cmH2O was maintained. The lung was processed for light-microscopic examination by using a freeze substitution technique. Results show that adventitial area was significantly decreased after sustained but not acute bronchonconstriction. The mechanism of this change, which contradicts our hypothesis, is unclear. However, the decrease of adventitial area could increase rather than decrease the effect of lung parenchymal tethering and attenuate airway narrowing.

Administration, Inhalation↗
PubMed1996

Reactivity of glomerular and serum IgA1 to jacalin in IgA nephropathy.

To analyze O-linked oligosaccharides (O-glycans) in the hinge region of IgA1 in IgA nephropathy (IgAN), the reactivity of IgA1 to jacalin, which specifically binds to O-glycans, was investigated. Initially, renal biopsy specimens from 5 patients with IgAN and 3 patients with other renal diseases were investigated in an immunofluorescence study with jacalin, monoclonal antihuman IgA1 and IgA2 antibodies. All of the renal biopsy specimens of IgAN and none of other renal diseases were positively stained by both FITC-labeled jacalin and monoclonal anti-IgA1 antibody. The glomerular staining patterns of FITC-jacalin were similar to those of the monoclonal anti-IgA1 antibody. IgA2 was negative in all specimens. Based on the positive reactivity of deposited IgA1 to jacalin, the binding ability of serum IgA1 to jacalin was evaluated by inhibition assay using D-galactose in patients with IgAN (n = 58), other primary glomerulonephritides (PGN) (n = 41), and healthy controls (n = 52). The frequencies of the patients with serum IgA1 having a high affinity for jacalin were significantly greater in IgAN (19/58, 32.8%) compared with the healthy controls (2/52, 3.8%) and other PGN (4/41, 9.8%). These results suggested that the increased reactivity of O-glycan(s) in the IgA1 hinge region to jacalin is due to an unusual glycosylation of serum IgA1 in IgAN.

Adult↗
PubMed1996

Factors influencing survival following pulmonary resection for metastatic colorectal carcinoma.

The results of pulmonary resection and clinical factors relating to long-term survival were evaluated in 29 patients with histologically proven pulmonary metastasis from colorectal carcinoma. The patients were followed up from 4 months to 120 months, with an average of 43.7 months. Overall 5- and 10-year survival rates were 41% and 34% respectively. The 5- and 10-year survival rates in patients with metastatic nodules 30 cm or less in diameter were 77% and 58%, respectively, a significantly better result than in those with metastatic nodules over 30 mm in diameter. Survival in patients without nodal involvement was significantly better than that in patients with lymph node metastases. Multivariate analysis according to Cox proportional hazards model demonstrated that the size of the metastasis was an independent prognostic factor.

Adult↗
PubMed1996

EI-1507-1 and -2, novel interleukin-1 beta converting enzyme inhibitors produced by Streptomyces sp. E-1507.

EI-1507-1 and -2, novel interleukin-1 beta converting enzyme (ICE) inhibitors, were isolated from the culture broths of Streptomyces sp. E-1507. EI-1507-1 and EI-1507-2 selectively inhibited the recombinant human ICE activity with IC50 values of 0.23 and 0.42 microM, respectively. EI-1507-1 and EI-1507-2 also inhibited mature interleukin-1 beta secretion from THP-1 cells with IC50 values of 1.1 and 1.4 microM, respectively.

Amino Acid Sequence↗
PubMed1996

Usefulness of Japanese staging in the prognosis of patients treated operatively for adenocarcinoma of the head of the pancreas.

BACKGROUND: Differences in the clinical staging in Japan from that of the Union Internationale Contre le Cancer (UICC) staging system may account for discrepancies in the prognosis of carcinoma of the pancreas between Japan and the United States of America. STUDY DESIGN: This study compares the usefulness of Japanese staging with the UICC staging in 1,689 patients who underwent resection for carcinoma of the pancreatic head registered with the Japan Pancreas Society. RESULTS: The survival rate was correlated with the Japanese stage classification. The survival rate of patients with T4 tumors was surprisingly better than for those with T2 or T3 tumors. The extent of lymph node involvement and of extrapancreatic tissue invasion reflected the prognosis. The UICC staging system did not reflect differences in prognosis among the four stages, especially between stages II and III. CONCLUSIONS: To establish a more practical and universal staging system for carcinoma of the pancreas, the Japanese system may offer improvements in predicting the prognosis of American or European patients with this disease.

Adenocarcinoma↗
PubMed1996

[Hyperintense brain lesions on T1-weighted MRI after parenteral nutrition].

We experienced five children having T1-shortening lesions in basal ganglia or thalami on magnetic resonance imaging (MRI), which were supposed to be caused by manganese (Mn) overdoses. Instead of the presence of above mentioned lesions, no neurological manifestations corresponding to them had developed in all patients. This observation suggests that a MRI is useful for detecting the side effects caused by overdoses of Mn in patients having parenteral nutrition.

Adolescent↗