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Biomedical subjects

M Ueda

Publications and source records attributed to M Ueda.

At least 433 records · Page 24Linked to original sources
PubMed1997

Interleukin 1 receptor blockade reduces tumor necrosis factor production, tissue injury, and mortality after hepatic ischemia-reperfusion in the rat.

The inflammatory cytokines interleukin (IL) 1 and tumor necrosis factor (TNF) may play an important role in hepatic ischemia-reperfusion (I/R) injury. To study the role of IL-1 in hepatic I-R injury, we investigated the effect of pretreatment with IL-1 receptor antagonist (IL-1ra) on the production of IL-1, TNF, histological findings in the liver, and the survival rate for 7 days. Rats were subjected to 90 min of partial liver warm ischemia by clamping the vessels of the left and middle lobes. In the IL-1ra-treated group, IL-1ra was given 5 min before liver ischemia was induced. IL-1alpha and TNF levels were determined in blood and liver at 0, 30, 90, and 180 min after reperfusion. In a second experiment to determine the effect of IL-1ra pretreatment on survival rate, after 90 min of partial liver ischemia, the right lateral and caudate lobes were excised, leaving only the ischemic lobes. In both groups, IL-1alpha was undetectable in blood, but increased in liver tissue. TNF increased in both blood and liver tissue as reperfusion time increased. Histological evidence of tissue injury was minimal in the IL-1ra-treated group. Furthermore, in the IL-1ra-treated group, the production of TNF decreased in both blood and liver tissue compared with the nontreated group. Survival rates in the IL-1ra-treated and nontreated group were 80% and 30%, respectively. The data demonstrated that the production of IL-1 and TNF increases in hepatic I-R injury and that pretreatment with IL-1ra protects the liver from ischemic insult, indicating an important role for IL-1 in I-R injury.

Animals↗
PubMed1997

Analysis of carbon source-regulated gene expression by the upstream region of the Candida tropicalis malate synthase gene in Saccharomyces cerevisiae.

We investigated the regulation of expression of a gene encoding malate synthase (MS) of an n-alkane-utilizable yeast Candida tropicalis in the yeast Saccharomyces cerevisiae, where its expression is highly induced by acetate. By comparing levels of gene expression in cells grown on glucose, acetate, lactate, and oleic acid, we found that the increase in gene expression was due to a glucose repression-derepression mechanism. In order to obtain information concerning the regulation of the gene expression, a fusion gene which consists of the 5'-upstream region of MS-2 (UPR-MS-2) and the lacZ gene (encoding Escherichia coli beta-galactosidase), was introduced into S. cerevisiae, and beta-galactosidase activities were measured with cells grown on glucose or acetate. Deletion analysis of UPR-MS-2 revealed that the region between -777 and -448 (against the translation initiation codon) enhanced the level of gene expression in both glucose- and acetate-grown cells. In this region, sequences which resemble binding sites of Rap1p/Grf1p/Tufp, a global transcription activator, were found at seven locations and one was found for another pleiotropic activator Abf1p. The result also suggested the presence of multiple upstream repression sequences (URSs), which function specifically in glucose-grown cells, in the region between -368 and -126. In the repressing region, there were three tandem C(A/T)CTCCC sequences and also a putative binding site of Mig1p, a transcriptional repressor which mediates glucose repression of several other genes. When MIG1 gene of S. cerevisiae was disrupted, the expression of the UPR-MS-2-lacZ gene in glucose-grown cells increased approx. 10-fold. Furthermore, the effect of deletion of a putative Mig1p binding site was abolished in the MIG1-disrupted strain, suggesting Mig1p binds to this site and brings about glucose repression. When the SNF1 gene was disrupted, the high level gene expression observed in acetate-grown cells bearing UPR-MS-2 was abolished. This indicated that derepression of UPR-MS-2 -mediated gene expression was dependent on Snf1p, as is the case of genes encoding isocitrate lyase and gluconeogenic enzymes in S. cerevisiae.

Acetates↗
PubMed1997

Reevaluation of postoperative radiotherapy for thoracic esophageal carcinoma.

PURPOSE: To reevaluate postoperative radiotherapy for thoracic esophageal carcinoma. METHODS AND MATERIALS: Reviewed were the outcome of 89 patients who underwent esophagectomy with systematic dissection of regional lymph nodes between 1988 and 1993. Of the 89 patients, 19 underwent no adjuvant treatment, 22 underwent adjuvant chemotherapy alone, and 48 underwent postoperative radiotherapy. Twelve of the 48 also underwent adjuvant chemotherapy. RESULTS: All patients who experienced local-regional recurrence had lymph node metastases at the time of surgery. The actuarial local-regional control rate at 2-year of follow-up was 94% for patients with lymph node metastases at the time of surgery who underwent postoperative radiotherapy alone or plus chemotherapy, and 74% for those who underwent adjuvant chemotherapy alone. The local-regional control rate was significantly better for those who had undergone postoperative radiotherapy (p < 0.01). CONCLUSIONS: Postoperative radiotherapy still plays an important role as adjuvant treatment.

Adult↗
PubMed1997

Scrape cytology of pemphigus vulgaris of the nipple, a mimicker of Paget's disease.

A case of histologically and immunocytochemically confirmed pemphigus vulgaris of the nipple examined by scrape cytology is reported. The scrape cytology showed isolated and somewhat loosely clustered cells with basophilic cytoplasm and vesicular hyperchromatic nuclei dysplaying prominent nucleoli, suggesting Paget's disease of the nipple. However, histological examination of the resected tissue together with the direct immunofluorescence technique for demonstration of in vivo-bound immunoglobulin to epithelium confirmed the diagnosis of pemphigus vulgaris. The use of an immunoperoxidase stain for IgG on the Papaniolaou-destained smear also gave a positive reaction on the cell membranes and provided a precise cellular diagnosis of the lesions. Cytodiagnostic pitfalls of these rare breast lesions are discussed, as well as the diagnostic value of immunocytochemistry.

Aged↗
PubMed1997

Malignant pleural effusions due to adeno-endocrine-cell carcinoma of the appendix: a case report.

The cellular features of adeno-endocrine-cell carcinoma of appendiceal origin are presented. The pleural fluid contained metastatic predominantly atypical cells in linear cluster accompanied by numerous mesothelial cells. The cells had small round nuclei, with a slight tendency to molding; nucleoli were absent. The cytologic findings in Papanicolaou-stained smears of the pleural fluid suggested a metastatic small-cell carcinoma of the lung. Subsequently, adeno-endocrine-cell carcinoma of the appendix was demonstrated at autopsy. Reports of such occurrences are few; no study, to the best of our knowledge, has previously documented the cytologic diagnosis in pleural fluid.

Adenocarcinoma↗
PubMed1997

Position-independent and high-level expression of human alpha-lactalbumin in the milk of transgenic rats carrying a 210-kb YAC DNA.

The level of expression of transgenes in transgenic animals varies among lines, and is often much lower than that of endogenous genes (position effects). In order to surmount position effects and establish a more efficient production system of transgenic animals producing pharmaceutical proteins in their milk, transgenic rats carrying 210-kb YAC DNA containing the human alpha-lactalbumin gene were produced. Three transgenic lines transmitted the transgene to the next generation. They had one copy of the alpha-lactalbumin gene and secreted human alpha-lactalbumin in their milk at concentrations of 2.0-4.3 mg/ml. No position effect was seen. The transgene was expressed specifically in the mammary gland of the transgenic rats. The 210-kb region is thought to contain all the DNA elements required for proper expression of the human alpha-lactalbumin gene. The YAC carrying the human alpha-lactalbumin gene is a potential vector for the expression of foreign genes in the mammary gland.

Animals↗
PubMed1997

Reorientation of large DNA molecules in concentrated polyacrylamide solution during crossed-field electrophoresis.

Recently, we found that, in concentrated neutral solutions, DNA molecules migrate in linear conformation under steady electric field. In this paper, we report the conformational change of DNA during 120 degree crossed-field electrophoresis in the same polymer solution. We found that, in concentrated polyacrylamide solutions, the reorientation process of DNAs becomes simple: the DNA goes back along the previous track and the reorientation time is longer for larger DNA. Such a backtrack motion has been thought to be an essential motion for the separation of DNA fragments in pulsed field gel electrophoresis. We expect that this phenomenon is useful for a more efficient separation technique of large DNAs than the current pulsed field gel electrophoresis.

Acrylic Resins↗
PubMed1997

Expression of 17 beta-hydroxysteroid dehydrogenase type IV in chick retinal pigment epithelium.

Retinal pigment epithelium (RPE) has essential roles that maintain functions of the neural retina. Previously, we described that the 3b5 monoclonal antibody (3b5 mAb) recognized the RPE cells in the chick embryonic eye. In the present study, a gene coding for the 3b5 antigen has been cloned and sequenced. A 10-day-old embryonic RPE cDNA library was constructed in lambda Uni-ZAP XR, and screened with the 3b5 mAb as a probe. The complete nucleotide sequence of the antigen recognized by the 3b5 mAb was obtained. The cDNA encodes a 735 amino acid protein with a calculated molecular mass of 80,147 Da. The deduced amino acid sequence shares 72% identity with the human 17 beta-hydroxysteroid dehydrogenase (17 beta-HSD) type IV. Northern blot analysis detected a 2.9 kb transcript. Immunohistochemical and in-situ hybridization studies revealed that 17 beta-HSD type IV was preferentially expressed in the RPE cells. The expression of steroid metabolizing enzymes in the RPE cells is able to create estrogenic environment, which may have a role of maintenance of the neural retina.

17-Hydroxysteroid Dehydrogenases↗
PubMed1997

Characterization of the intron-containing citrate synthase gene from the alkanotrophic yeast Candida tropicalis: cloning and expression in Saccharomyces cerevisiae.

Citrate synthase, an essential enzyme of the tricarboxylic acid cycle in mitochondria, was purified from acetate-grown Candida tropicalis. Results from SDS-PAGE and gel filtration showed that this enzyme was a dimer composed of 45-kDa subunits. A citrate synthase cDNA fragment was amplified by the 5'-RACE method. Nucleotide sequence analysis of this cDNA fragment revealed that the deduced amino acid sequence contained an extended leader sequence which is suggested to be a mitochondrial targeting signal, as judged from helical wheel analysis. Using this cDNA probe, one genomic citrate synthase clone was isolated from a yeast lambdaEMBL3 library. The nucleotide sequence of the gene encoding C. tropicalis citrate synthase, CtCIT, revealed the presence of a 79-bp intron in the N-terminal region. Sequences essential as yeast splicing motifs were present in this intron. When the CtCIT gene including its intron was introduced into Saccharomyces cerevisiae using the promoter UPR-ICL, citrate synthase activity was highly induced, which strongly indicated that this intron was correctly spliced in S. cerevisiae.

Amino Acid Sequence↗
PubMed1997

Immunochemically distinct NADP-linked isocitrate dehydrogenase isozymes in mitochondria and peroxisomes of Candida tropicalis.

Although peroxisomal localization of NADP-linked isocitrate dehydrogenase (Idp) was first demonstrated in Candida tropicalis, the mitochondrial isozyme has not been found in this yeast. Here we report that the presence of mitochondrial Idp in the yeast was demonstrated by screening for its gene with a DNA probe containing conserved sequences of Idps from various organisms. The nucleotide sequence of the gene (CtIDP1) revealed a 1,290-bp open reading frame corresponding to a 430-amino-acid protein with a high similarity to previously reported Idps. Overexpression of CtIDP1 in Saccharomyces cerevisiae gave a high intracellular Idp activity, and the purified recombinant Idp was shown to be a homodimer with a subunit molecular mass of approximately 44 kDa, different from that of peroxisomal Idp (45 kDa) previously purified from C. tropicalis. Western blot analysis of the subcellular fractions from acetate-grown C. tropicalis with polyclonal antibodies raised against the recombinant CtIdp1 showed that the CtIdp1 in C. tropicalis was localized in mitochondria but not in peroxisomes. Similar levels of CtIDP1 mRNA and its protein product were detected in cells grown on glucose, acetate, and n-alkane, although a slight decrease was observed in n-alkane-grown cells. From these results, CtIdp1 was demonstrated to be mitochondrial Idp. The properties of mitochondrial Idp and peroxisomal Idp isozymes were proven to be similar, but they were immunochemically distinct, suggesting the presence of another gene responsible for peroxisomal Idp in C. tropicalis.

Amino Acid Sequence↗
PubMed1997

Genetic immobilization of cellulase on the cell surface of Saccharomyces cerevisiae.

We tried genetically to immobilize cellulase protein on the cell surface of the yeast Saccharomyces cerevisiae in its active form. A cDNA encoding FI-carboxymethylcellulase (CMCase) of the fungus Aspergillus aculeatus, with its secretion signal peptide, was fused with the gene encoding the C-terminal half (320 amino acid residues from the C terminus) of yeast alpha-agglutinin a protein involved in mating and covalently anchored to the cell wall. The plasmid constructed containing this fusion gene was introduced into S. cerevisiae and expressed under the control of the glyceraldehyde-3-phosphate dehydrogenase promoter from S. cerevisiae. The CMCase activity was detected in the cell pellet fraction. The CMCase protein was solubilized from the cell wall fraction by glucanase treatment but not by sodium dodecyl sulphate treatment, indicating the covalent binding of the fusion protein to the cell wall. The appearance of the fused protein on the cell surface was further confirmed by immunofluorescence microscopy and immunoelectron microscopy. These results proved that the CMCase was anchored on the cell wall in its active form.

Aspergillus↗
PubMed1997

Genomic organization and chromosomal localization of the human casein gene family.

Five yeast artificial chromosome (YAC) clones containing the human casein gene family were isolated and characterized to study the control mechanisms for the expression of these genes. Partial restriction analysis in conjunction with the chromosomal fragmentation method and fluorescence in situ hybridization (FISH) analysis were performed to construct a detailed physical map of the casein gene family and to determine the chromosomal localization of these genes. The isolated YAC clones 748F3, 750D11, 882G11, 886B3 and 960D2 were 1.2 Mb, 860 kb, 800 kb, 1.5 Mb and 1.5 Mb in size, respectively. The clones 748F3, 882G11, 886B3 and 960D2 contained the entire casein gene family, while the kappa-casein gene was absent in 750D11. The human alphaS1-, beta- and kappa-casein genes were found to be closely linked and arranged in the order alphaS1-beta-kappa. The distance between alphaS1 and beta, and between alphaS1 and kappa was approximately 10 and 300 kb, respectively. The beta-casein gene was oriented in the opposite direction to the alphaS1- and kappa-casein genes. The casein gene family was localized to chromosome 4q21.1 by FISH analysis.

Caseins↗
PubMed1997

Two-directional aortic annular enlargement for aortic valve replacement in the small aortic annulus.

We have encountered 3 patients with a small aortic annulus for whom the conventional posterior enlargement alone was not extensive enough to implant an artificial valve of acceptable size. Therefore, we performed two-directional enlargement, which is a combination of posterior and anterior enlargement. First, the posterior enlargement was done, and then an additional aortotomy was made anteriorly and extended to the ventricular septum. The aortic annulus was enlarged by 68% after the two-directional enlargement. At a follow-up of 31 months, the patients' functional status was New York Heart Association class I.

Adult↗
PubMed1997

Dibutyryl cyclic adenosine monophosphate attenuates lung injury caused by cold preservation and ischemia-reperfusion.

OBJECTIVE: Dibutyryl adenosine 3',5'cyclic monophosphate (db-cAMP) is a membrane-permeable analog of adenosine 3',5'cyclic monophosphate (cAMP). We examined the effect of db-cAMP against lung injury caused by cold preservation and ischemia-reperfusion. METHODS: Rats were divided into three groups (each n = 6) according to the presence or absence of db-cAMP in the preservative solution and cold ischemia (4 degrees C for 15 hours). In the fresh group, the lung was flushed with the preservative solution and reperfusion was performed immediately. In the control group and the db-cAMP group, the lung was flushed either with the solution or with a combination of the solution plus db-cAMP, respectively, and preserved at 4 degrees C for 15 hours. The lung was reperfused for 60 minutes in an ex vivo rat lung perfusion model. RESULTS: The shunt ratios of the reperfused lung in the db-cAMP group were 4.0% +/- 1.6% and 3.4% +/- 1.2% 10 and 60 minutes, respectively, after the initiation of reperfusion, being as low as those in the fresh group and significantly lower than those in the control group (p < 0.01). The wet/dry weight ratio of the lung tissue after reperfusion was 5.99 +/- 1.50 in the db-cAMP group, which was similar to that in the fresh group (5.45 +/- 0.23) and significantly lower than that in the control group (14.20 +/- 3.43) (p < 0.01). Electron microscopic examination showed less damage in the pulmonary arterial endothelium in the db-cAMP group. CONCLUSIONS: We conclude that db-cAMP attenuates the lung injury by cold preservation and ischemia-reperfusion, at least partly by protection of the vascular endothelium.

Animals↗
PubMed1997

Renoprotective effects of a combined endothelin type A/type B receptor antagonist in experimental malignant hypertension.

We previously showed that plasma endothelin-1 (ET-1) concentration was increased in deoxycorticosterone acetate (DOCA)-salt-induced malignant hypertension in spontaneously hypertensive rats (SHR). In contrast, in normal SHR, this value is similar to that seen in Wistar-Kyoto (WKY) rats. The purpose of this study was to examine the effects of the new combined ET type A/type B (ETA/B) receptor antagonist, TAK-044, on the development of hypertension in this model of malignant hypertension. TAK-044 10 mg/kg, which effectively blocks both ETA and ETB receptors, was administered intraperitoneally once per day for 4 weeks in DOCA-salt SHR, and the effects on ET-1 and other parameters were compared with the same values in untreated WKY rats, untreated DOCA-salt SHR, and hydralazine-treated DOCA-salt SHR. DOCA-salt caused marked increases in blood pressure, blood urea nitrogen (BUN), serum creatinine, and plasma ET-1 concentrations in SHR. Both TAK-044 and hydralazine significantly suppressed the increase in blood pressure in DOCA-salt SHR to the same extent. Both treatments also suppressed the increase in BUN and serum creatinine, but this attenuation was less marked with hydralazine than with TAK-044. Neither TAK-044 nor hydralazine affected plasma ET-1 concentration in this model. TAK-044 significantly reduced kidney weight in DOCA-salt SHR, whereas the decrease seen with hydralazine was less marked. Prevention of DOCA-salt-induced renal structural injury (mesangial hypercellularity, glomerular sclerotic changes, and tubulointerstitial damage) in this model was clearly greater with TAK-044 treatment than with hydralazine treatment. These results suggest that endogenous ET-1 may, at least in part, contribute to renal functional and structural damage in malignant DOCA-salt SHR. Our results raise the possibility of renoprotective effects of ETA/B receptor blockers in certain forms of malignant hypertension.

Animals↗
PubMed1997

Surgical treatment for primary esophageal cancer developing after pharyngolaryngectomy for head and neck cancer.

BACKGROUND: Primary esophageal cancer developing after hypopharyngeal or laryngeal cancer is increasing in frequency, but operative treatment of such cases is not well established. The proximity of both cancers could produce interactive influence on surgical procedures and risk factors. There have been few reports focusing on surgical strategy for such cases. METHODS: We retrospectively investigated the most recent series of 18 patients who had previously undergone pharyngolaryngectomy for cancer and subsequently underwent esophagectomy for second primary cancer of the esophagus. At esophagectomy special care was taken to preserve the tracheal vascularity and to select adequate procedures for lymph node dissection and bowel reconstruction. RESULTS: Curative resection as confirmed macroscopically was achieved in all cases except one. Lymph node involvement was found in half of the patients. No major postoperative complication was observed except for partial necrosis of the trachea in two cases that were conservatively treated. No patient died during hospitalization. The 3-year survival rate was 64% overall and 55% in cases with lymph node involvement. CONCLUSIONS: Although increased operative risk was expected in esophagectomy after pharyngolaryngectomy, our operative results were acceptable. Most risk factors were controllable by selecting appropriate operation procedures. In patients with technically resectable cancer, esophagectomy with systematic lymph node dissection is recommended as in ordinary esophageal cancer.

Aged↗