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Biomedical subjects

M Kuroda

Publications and source records attributed to M Kuroda.

At least 199 records · Page 11Linked to original sources
PubMed1997

Oncogenic transformation and inhibition of adipocytic conversion of preadipocytes by TLS/FUS-CHOP type II chimeric protein.

Myxoid liposarcomas are characterized by t(12; 16)(q13;p11) translocation and expression of TLS/ FUS-CHOP chimeric transcripts (types I to III). Among these, the type II transcript is expressed in the majority of cases of myxoid and round cell liposarcoma. To investigate the function of the type II chimeric protein, we obtained stable transformants of ST-13, a murine preadipocytic cell line, which express TLS/FUS-CHOP type II protein (ST-TC) or CHOP protein (ST-C) as well as vector-transfected controls (ST-V). ST-TC and ST-C cells showed almost complete or partial resistance to adipogenic conversion by insulin and thiazolidinedione, respectively. Induction by adipogenic stimulation of the adipocytic genes such as C/EBP alpha, aP2, and adipsin was almost totally suppressed in the ST-TC cells, whereas in ST-C cells C/EBP alpha alone was induced without induction of aP2 and adipsin. Transcriptional suppression of the C/EBP alpha gene in ST-TC cells was suggested by the results of chloramphenicol acetyltransferase (CAT) assay showing a significantly lower C/EBP alpha promoter activity compared with findings in ST-C and ST-V cells. Failure to rescue adipogenic conversion by ectopic expression of C/EBP alpha in ST-TC cells suggested a functional impairment of C/EBP alpha to induce expression of downstream genes. TLS/FUS-CHOP type II protein showed transforming activity, as evidenced by loss of contact inhibition of growth, anchorage-independent growth in soft agar, and tumor formation in nude mice, showing typical histological features of myxoid liposarcoma seen in humans. These findings suggest important roles for TLS/FUS-CHOP type II protein in the oncogenesis of myxoid liposarcoma.

Adipocytes↗
PubMed1997

[A case of scrotal cancer with inguinal lymph node metastasis treated by multidisciplinary modalities including chemotherapy with methotrexate, bleomycin and cisplatin].

We report a case of scrotum with inguinal lymph node metastasis which was successfully treated by multidisciplinary modalities including combination chemotherapy and radiotherapy. A 60-year-old man was admitted with ulcerative induration of the scrotum and inguinal lymph node swelling. Biopsy of the scrotal skin showed squamous cell carcinoma. He received 4 courses of combination chemotherapy with methotrexate, bleomycin and cisplatin. The primary lesion disappeared macroscopically and metastatic lymphadenopathy showed 50% reduction in size. Both lesions were further treated with radiotherapy (60 Gy). Because the primary lesion became ulcerative 7 months after irradiation, partial resection of the scrotum was performed. He has been free of recurrence 22 months after chemotherapy.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed1997

Deuterium oxide (heavy water) accelerates actin assembly in vitro and changes microfilament distribution in cultured cells.

While deuterium oxide (D2O) is known to produce various biological effects in living animals and cultured cells, the detailed mechanisms by which it does so remain unclear. The present study was designed to assess the effects of D2O on microfilaments (MFs) via fluorescence staining of BALB 3T3 cells and in vitro actin polymerization studies. After BALB 3T3 cells had been exposed to a concentration of more than 30% D2O for several hours, stress fibers in the peripheral region became thick and distinct, while the quantity of perinuclear MFs was drastically reduced. This effect was transient and returned to the original distribution within 12 h. Cytoplasmic F-actin (FA) also increased transiently coincident with the enhancement of stress fibers. The pattern of cell locomotion became simpler, and total locomotor activity was suppressed in a D2O concentration-dependent manner. Analysis of in vitro studies demonstrated that, when purified G-actin was polymerized in D2O at a concentration greater than 10%, the rate of actin polymerization was accelerated, whereas the total amount of polymerized actin at the steady state in D2O was the same as that in H2O controls. A gelation assay and transmission electron microscopy (TEM) showed that the network of crosslinked FA with alpha-actinin became denser in 30% D2O than in H2O. These findings concerning actin polymerization and FA gelation suggest that the alteration of stress fibers in cultured cells is caused by a direct effect of D2O on cellular MF dynamics.

3T3 Cells↗
PubMed1996

Atomic force microscopy proposes a novel model for stem-loop structure that binds a heat shock protein in the Staphylococcus aureus HSP70 operon.

The Staphylococcus aureus HSP70 operon produces a polycistronic RNA in response to heat shock, and ORF37 is the first protein to be translated. The promoter of this operon contains a palindromic nucleotide sequence that may form a stem-loop structure. Structural analysis of the promoter regions by atomic force microscopy (AFM) revealed a quadruplet that consists of a pair of stem-loops. A novel "SL2S' (Stem-Loop-Loop-Stem) model was proposed for this structure. AFM also revealed the binding of ORF37 to the quadruplet, establishing a molecular mechanism for this heat shock gene expression; ORF37 acts as a regulator by binding to the SL2S structure in the promoter.

Base Sequence↗
PubMed1996

Soyacystatin, a novel cysteine proteinase inhibitor in soybean, is distinct in protein structure and gene organization from other cystatins of animal and plant origin.

Cystatins, cysteine proteinase inhibitors, deserve note because of their regulatory and protective functions in plant tissues. We isolated both genomic DNA and cDNA clones from soybean that encode a cystatin consisting of 245 amino acid residues (soyacystatin). It is, while basically similar in sequence to known cystatins that are generally in the range of 12-15 kDa, characterized by having extremely large extension sequences in both its amino and carboxyl termini. The genomic DNA encoding soyacystatin is also unique in that it consists of four exons with three introns in its coding regions. The mRNA for soyacystatin is distinctly expressed in soybean seeds 2 weeks after flowering. Soyacystatin purified from mature soybean seeds had a molecular mass of about 26 kDa on SDS/PAGE which suggests that it contains the extension sequences. Papain-inhibition experiments demonstrate that this endogenous soyacystatin has almost the same inhibitory activity as that of its deletion mutant (102 amino acid residues) recombinantly produced by truncation of the amino and carboxyl terminal extensions, indicating that the occurrence of the extensions does not affect the cystatin activity. Immunohistochemical experiments reveal that soyacystatin is expressed nearly uniformly in the cotyledons. These results also suggest the possible occurrence of a cysteine proteinase as the target enzyme of soyacystatin.

Amino Acid Sequence↗
PubMed1996

Synaptic relationships between axon terminals from the mediodorsal thalamic nucleus and layer III pyramidal cells in the prelimbic cortex of the rat.

A combined study of anterograde axonal degeneration and Golgi electron microscopic technique was designed to examine the distribution and density of axon terminals from the mediodorsal thalamic nucleus (MD) over layer III pyramidal cells in the prelimbic cortex of the rat. The reconstructive analysis of serial ultrathin sections of gold-toned apical and basal dendrites of layer III pyramidal cells showed that degenerating thalamocortical axon terminals from MD formed asymmetrical synaptic contacts predominantly with dendritic spines of the identified basal dendrites as well as apical dendrites. There was little difference in the numerical density of thalamocortical synapses from MD per unit length of both apical and basal dendrites.

Animals↗
PubMed1996

Intraductal papillary adenocarcinoma with mucin hypersecretion and coexistent invasive ductal carcinoma of the pancreas with apparent topographic separation.

We report a 66-year-old man who had a cystic intraductal papillary adenocarcinoma containing a papillary adenoma, in the head of the pancreas and a coexistent invasive, well differentiated solid tubular adenocarcinoma in the tail of the pancreas. He was hospitalized with acute epigastralgia. Computed tomography demonstrated a multilocular cystic mass in the head of the pancreas and a solid tumor in the tail. Endoscopic retrograde pancreatography showed mucin secretion from an enlarged papilla of Vater, marked dilatation of the main pancreatic duct in the head and body, cystic dilatation of the uncinate branch, and irregular narrowing of the main pancreatic duct in the tail. Total pancreatectomy was performed. Between the cystic tumor and the solid tumor there was a distance of 4.8 cm of normal pancreatic parenchyma and duct, recognized both grossly and microscopically. The patient died 35 months after the operation. At autopsy, peritonitis carcinomatosa was found in the abdominal cavity. Microscopically, disseminated nodules were also well differentiated tubular adenocarcinoma. The apparent anatomic separation of these two tumors within the pancreas is extremely unusual.

Aged↗
PubMed1996

Potent growth inhibitory activity of a novel Ornithogalum cholestane glycoside on human cells: induction of apoptosis in promyelocytic leukemia HL-60 cells.

Growth inhibitory activities of a novel 22-homo-23-norcholestane glycoside found in bulbs of Ornithogalum saundersiae were examined in vitro using human promyelocytic leukemia HL-60 cells, human T-lymphocytic leukemia MOLT-4 cells, and mitogen-stimulated human peripheral-blood mononuclear cells (PBMC). The growth of HL-60 cells and MOLT-4 cells was strongly suppressed in the presence of the glycoside; the IC50s of which were 21.0 and 18.0 nM, respectively. Suppressive effect of the glycoside on HL-60 cell growth appears to be mediated partially through induction of apoptosis which was demonstrated by the presence of DNA fragmentation of the leukemic cells. Flow cytometric analysis of glycoside-treated HL-60 cells also demonstrated apoptotic cells with low DNA content and showed a decrease of G0/G1 cells and a concomitant increase of S and/or G2M cells. The growth inhibiting effect of the glycoside on HL-60 cells was promoted by calcium and was inhibited in the presence of zinc, which support involvement of endonuclease activation in the glycoside-induced apoptosis. The glycoside also inhibited mitogen-stimulated blastogenesis of PBMC, the IC50 of which was 6.2 nM. These results provided the first evidence ever for the potent growth inhibitory activity of Ornithogalum glycoside on human leukemia cell lines and PBMC.

Antineoplastic Agents↗
PubMed1996

A pyrroline glucoside ester and steroidal saponins from Lilium martagon.

A new phenylpropanoid ester of a pyrroline derivative and two new steroidal saponins were isolated from the fresh bulbs of Lilium martagon, along with several previously known compounds. The structures of the new compounds were determined by spectroscopic data, hydrolysis, and by comparison with spectral data of known compounds to be (-)-5-hydroxy-3-methyl-3-pyrrolin-2-one 5-O-(6-O-p-coumaroyl-beta-D- glucopyranoside), (25S)-spirost-5-ene-3 beta,17 alpha, 27-triol 3-O-[O-beta-D-glucopyranosyl-(1-->2)-O-beta-D-glucopyranosyl- (1-->4)-beta-D-glucopyranoside] and (25S)-5 alpha-spirostane-3 beta,17 alpha,27-triol 3-O-[O-beta-D-glucopyranosyl-(1-->2)-O-beta-D-glucopyranosyl-(1-->4)-bet a-D- glucopyranoside], respectively. Lilium martagon crosses well with L. hansonii to produce a valuable garden hybrid lily. In this study, the secondary metabolites of L. martagon were revealed to be closely related to those of L. hansonii, giving a good example of the correlation between the secondary metabolites and cross-compatibility.

Carbohydrate Sequence↗
PubMed1996

Steroidal saponins from Hosta longipes and their inhibitory activity on tumour promoter-induced phospholipid metabolism of HeLa cells.

Three new spirostanol saponins and two new furostanol saponins were isolated from the underground parts of Hosta longipes. Their structures were determined to be (25R)-5 alpha-spirostane-2 alpha, 3 beta-diol (gitogenin) 3-O-{O-alpha-L -rhamnopyranosyl-(1-->2)-beta-D-galactopyranoside}, gitogenin 3-O-{O-alpha-L-rhamnopyranosyl-(1-->2) -O-[beta-D-glucopyranosyl-(1-->4)]-beta-D-galactopyranoside-, (25R)-5 alpha-spirostan-3 beta-ol (tigogenin) 3-O-{O-alpha-L-rhamnopyranosyl-(1-->2) -O-[beta-D-glucopyranosyl-(1-->4)]-beta-D-galactopyranoside-, 26-O-beta-D-glucopyranosyl-22-O-methyl-(25R)-5 alpha-furostane-2 alpha,3 beta, 22 xi,26-tetrol 3-O-{O-alpha-L-rhamnopyranosyl -(1-->2)-beta-D-galactopyranoside} and 26-O-beta -D-glucopyranosyl-22-O-methyl-(25R)-5 alpha-furostane-2 alpha,3 beta,22 xi,26-tetrol 3-O-{O-alpha-L -rhamnopyranosyl-(1-->2)-O-[beta-D-glucopyranosyl -(1-->4)]-beta-D-galactopyranoside}, respectively. The isolated saponins and their derivatives were examined for inhibitory activity on 12-O-tetradecanoylphorbor-13-acetate-stimulated 32P-incorporation into phospholipids of HeLa cells as the primary screening test to find new antitumour-promoter compounds.

Carbohydrate Conformation↗
PubMed1996

Steroidal saponins from Nolina recurvata stems and their inhibitory activity on cyclic AMP phosphodiesterase.

Seven steroidal saponins were isolated from the stems of Nolina recurvata, five of which appeared to be new compounds and were assigned as spirosta-5,25(27)-diene-1 beta,3 beta-diol (neoruscogenin) 1-O--O-alpha-L-rhamnopyranosyl-(1--> 2)-O-[beta-D-xylopyranosyl-(1-->3)]-alpha-L-arabinopyranoside-, (25S)-spirost-5-ene-1 beta,3 beta-diol [(25S)-ruscogenin] 1-O-{O-alpha-L-rhamnopyranosyl-(1-->2)-O-[beta-D-xylopyranosyl-(1--> 3)]-alpha-L-arabinopyranoside}, neoruscogenin 1-O-{O-alpha-L-rhamnopyranosyl-(1-->2)-O-[beta-D-xylopyranosyl-(1--> 3)]-beta-D-fucopyranoside}, 26-O-beta-D-glucopyranosyl-22-O-methylfurosta-5,25(27)-diene-1 beta,3 beta,22 xi,26-tetrol 1-O--O-alpha-L-rhamnopyranosyl-(1--> 2)-O-[beta-D-xylopyranosyl-(1-->3)]-alpha-L-arabinopyranoside- and 26-O-beta-D-glucopyranosylfurosta-5,20(22),25(27)-triene-1 beta,3 beta,26-triol 1-O-{O-alpha-L-rhamnopyranosyl-(1--> 2)-alpha-L-arabinopyranoside}. The isolated saponins were evaluated for their inhibitory activity on cyclic AMP phosphodiesterase to identify new compounds with medicinal potential.

3',5'-Cyclic-AMP Phosphodiesterases↗
PubMed1996

Steroidal saponins from Sansevieria trifasciata.

The methanol extract of the whole plant of Sansevieria trifasciata has yielded 12 steroidal saponins, 10 of which are new constituents. The respective structures of the new compounds have been shown by the spectroscopic evidence, and alkaline- and acid-catalysed degradation. This is the first report of the isolation of steroidal saponins from S. trifasciata.

Carbohydrate Sequence↗
PubMed1996

Antibodies to E1 and E2/Protein X components of pyruvate dehydrogenase complex in sera of patients with primary biliary cirrhosis.

AIMS/METHODS: Using purified E1 component of pyruvate dehydrogenase complex (PDC) from bovine heart, we measured the levels of anti-E1 antibodies in PBC sera using ELISA and determined the degree of inhibition that these antibodies exerted on E1 enzyme activity. We also estimated levels of anti-E2/Protein X (Pro-X) antibodies in PBC sera using purified E2 and Pro-X of PDC which were copurified with E1. RESULTS/CONCLUSIONS: Anti-E1 antibodies were detected in 87.5% (35/40) of PBC sera. Some of these sera inhibited E1 enzyme activity but inhibition did not correlate with levels of anti-E1 antibodies. A high positive correlation (r = 0.918) was found between levels of anti-E1 and anti-E2/Pro-X antibodies, suggesting that anti-PDC antibody production was stimulated by PDC itself. Levels of IgG class anti-E2/Pro-X antibodies were significantly higher in sera of symptomatic PBC patients than in those of asymptomatic PBC patients. It was also found that patients who were positive for only IgM class anti-E2/Pro-X antibodies had early-stage PBC.

Animals↗
PubMed1996

Interleukin-6 induces proliferation of rat hepatocytes in vivo.

BACKGROUND/AIMS: The aim of this study was to assess the effect of interleukin-6 (IL-6) on the proliferation of hepatocytes and to study the interaction between IL-6 and hepatocyte growth factor (HGF) in vivo. METHODS: IL-6 was injected at a dose of 200 micrograms/mg subcutaneously into rats every day for 14 days. Liver and blood samples were obtained at 1, 3, 7 and 14 days during IL-6 administration. Hepatocyte proliferative activity of sera was measured using 3H-thymidine incorporation into cultured rat hepatocytes. To evaluate the proliferative activity of the hepatocytes in tissue sections, hepatic DNA content and immunostaining of the liver tissue sections for proliferating cell nuclear antigen (PCNA) were performed. Plasma HGF levels were measured using specific EIA. In addition, total RNA was extracted from the liver and expression of HGF mRNA was detected by RT-PCR. RESULTS: The DNA contents of liver taken from IL-6-treated rats were increased during IL-6 administration compared with untreated rats. Sera taken from IL-6-treated rats at various intervals during administration also significantly increased 3H-thymidine incorporation by cultured rat hepatocytes compared with sera from untreated rats, suppressing 3H-thymidine incorporation at day 1 and 3 by anti-HGF antibody. IL-6 itself did not increase 3H-thymidine incorporation. Increased expression of PCNA in these hepatocytes was noted from 1 day after IL-6 administration, and at 14 days, the number of PCNA-positive cells was sevenfold greater than in the livers of untreated rats. However, plasma HGF levels showed a peak at day 1, decreased gradually from day 3, and became undetectable by day 14. HGF mRNA expression in livers of IL-6-treated rats was suppressed from day 3 to day 14 of IL-6 administration. CONCLUSIONS: These data show that IL-6 induces an early phase of liver cell growth in vivo and suggest that an increase level of HGF mediates this effect.

Animals↗
PubMed1996

Detection of intraoperative incidents by electronic scanning of computerized anesthesia records. Comparison with voluntary reporting.

BACKGROUND: The use of a computerized anesthesia information management system provides an opportunity to scan case records electronically for deviations from specific limits for physiologic variables. Anesthesia department policy may define such deviations as intraoperative incidents and may require anesthesiologists to report their occurrence. The actual incidence of such events is not known. Neither is the level of compliance with voluntary reporting. METHODS: Using automated anesthesia record-keeping with long-term storage, physiologic data were recorded every 15 s from 5,454 patients undergoing noncardiothoracic surgery. Recorded measurements of blood pressure, heart rate, arterial oxygen saturation, and temperature were electronically analyzed for deviations from defined limits. The computer system also was used by anesthesiologists to report voluntarily those deviations as intraoperative incidents. For each electronically detected incident: 1) the complete automated anesthesia record was examined by two senior anesthesiologists who, by consensus, eliminated case records with artifact or in which context suggested that the incident was not clinically relevant, and 2) the anesthesia information management system database was checked for voluntary reporting. RESULTS: In 473 automated anesthesia records, 494 incidents were found by electronic scanning of 5,454 automated anesthesia records. Sixty intraoperative incidents were eliminated, 25 due to artifact and 35 due to context. When the remaining 434 intraoperative incidents were checked for voluntary reporting, 18 (4.1%) matching voluntary reports were found. All intraoperative incidents that were reported voluntarily also were detected by electronic scanning. Based on a 10% sample, the sensitivity rate of electronic scanning was 97.2% (35/36), and the specificity rate was 98.4% (427/434). Among 413 cases with electronically detected intraoperative incidents, there were 29 deaths (7.0%), whereas there were only 79 deaths (1.6%) among 5,041 cases without incidents (chi 2 = 58.5, P < 0.001). CONCLUSIONS: The use of an anesthesia information management system facilitated analysis of intraoperative physiologic data and identified certain intraoperative incidents with high sensitivity and specificity. A low level of compliance with voluntary reporting of defined intraoperative incidents was found for all anesthesiologists studied. Finally, there was a strong association between intraoperative incidents and in-hospital mortality.

Anesthesiology↗
PubMed1996

Case report: hepatic adenoma with bone marrow metaplasia in a patient with glycogen storage disease type 1a.

A 34 year old man with glycogen storage disease type 1a had two hepatic tumours since 18 years of age. They had continued to grow until he was 24 years old, but showed no further growth since then. He underwent a right hepatic trisegmentectomy with caudate lobectomy under veno-venous bypass. The tumour in the posterior segment showed nodule-within-nodule appearance. Histologically, the inner adenoma with dysplasia, bone marrow metaplasia and lymphocytic infiltration was separated by a fibrous band from the outer adenoma of usual histology.

Adenoma↗