Search PubMed⌕ Search

Biomedical subjects

H Inoue

Publications and source records attributed to H Inoue.

At least 955 records · Page 53Linked to original sources
PubMed1995

Microsatellite instability in multiple gastric cancers.

To better elucidate the role of genetic instability in the development of gastric cancer, microsatellite alterations were examined in a total of 30 gastric cancers that developed in 14 Japanese patients with multiple gastric cancers, which are considered to have possibly occurred under the same genetic background and in the same microenvironment of the stomach. Microsatellite instability (MSI) in multiple gastric cancers was recognized in 11 out of 14 cases (78.5%) and in 16 out of 30 cancers (53.3%). Eight out of 11 cases showing MSI exhibited a heterogeneity of microsatellite alterations. The incidence of microsatellite instability in the multiple gastric cancers cases was significantly higher than that in the solitary gastric cancer cases reported previously (20.8%: 5 out of 24 cases). These results suggested that (1) genetic instability plays a more important role in the development of multiple gastric cancers than in that of solitary gastric cancer and (2) the heterogeneity of MSI in multiple gastric cancers may not be a rare event, although the significance of the heterogeneity could not be clarified.

Adenoma↗
PubMed1995

Microsatellite instability in Japanese esophageal carcinoma.

Recent studies have shown that microsatellite instability (MSI) may play an important role in the development of various types of cancer. However, there have been only 2 reports describing MSI in esophageal carcinoma and the clinicopathologic significance of MSI in this malignancy has not yet been clarified. To better elucidate the role of genetic instability in the development of esophageal carcinoma, we investigated the presence of MSI in 32 cases of esophageal cancer using paired samples of fresh frozen tumor and normal tissue by a method based on the polymerase chain reaction. MSI was defined as occurring in tumors which showed altered banding patterns at one or more microsatellite loci. The incidence of MSI in esophageal carcinoma was 6 out of 32 patients. MSI was observed more frequently in cases with small-cell carcinoma (2 out of 2) than in cases with squamous-cell carcinoma (4 out of 29). No cases with adenocarcinoma or Barrett's metaplasia were included in our series. No significant correlations between MSI and other clinicopathologic parameters were observed. The present study suggests that (1) some Japanese esophageal carcinomas certainly correlate with DNA replication error, and (2) MSI may be more frequent in small-cell carcinoma of the esophagus than in squamous-cell carcinoma of the esophagus.

Aged↗
PubMed1995

8-Hydroxyadenine (7,8-dihydro-8-oxoadenine) induces misincorporation in in vitro DNA synthesis and mutations in NIH 3T3 cells.

An oligodeoxyribonucleotide containing 8-hydroxyadenine (OH8Ade) was chemically synthesized and single- and double-stranded c-Ha-ras gene fragments with OH8Ade at the second position of codon 61 were prepared. The single-stranded ras gene fragment was used as a template for in vitro DNA synthesis with the Klenow fragment of Escherichia coli DNA polymerase I, Taq DNA polymerase, rat DNA polymerase beta and mouse DNA polymerase alpha. The former two enzymes exclusively incorporated dTMP opposite OH8Ade. The DNA polymerases alpha and beta misinserted dGMP, and dAMP and dGMP, respectively. The c-Ha-ras gene was constructed using the double-stranded ras gene fragment containing OH8Ade and was transfected into NIH 3T3 cells. The gene with OH8Ade induced focus formation, indicating that OH8Ade elicited point mutations in cells. When c-Ha-ras genes present in transformed cells were analyzed, an A-->G transition and an A-->C transversion were detected. These results indicate that OH8Ade induced misincorporation in in vitro DNA synthesis and mutations in mammalian cells.

3T3 Cells↗
PubMed1995

Detection of cancer micrometastases in lymph nodes by reverse transcriptase-polymerase chain reaction.

There are few DNA-based studies that detect cancer micrometastases in lymph nodes. We have assayed for the specific detection of carcinoembryonic antigen (CEA)-expressing carcinoma cells in the lymph nodes of patients with gastrointestinal or breast carcinomas. A CEA-specific nested reverse transcriptase (RT)-PCR assay was optimized using limiting dilutions of a CEA-positive cancer cell line mixed with normal lymphocytes. The expression of CEA mRNA was studied in 100 carcinoma tissues, 75 normal mucosal tissues, and 15 lymph nodes from patients with cholelithiasis. Each of 117 lymph nodes from 13 patients with carcinoma was divided into two pieces: one was used for histological examination and the other for RT-PCR, and the results were compared. The sensitivity ratio was one CEA-expressing cancer cell detected in 1 x 10(5) normal lymphocytes. All carcinoma tissues and normal mucosal tissues expressed CEA mRNA, while no amplification was detected in any control lymph nodes. Thirty of 117 lymph nodes were histologically involved by carcinoma cells, and all of these yielded the expected product by RT-PCR. Of the remaining 87 histologically negative nodes, CEA mRNA was detected in 47 lymph nodes by RT-PCR. The positive rate increased from 26% by histological examination to 66% by RT-PCR. The assay by CEA-specific nested RT-PCR is not only sensitive but widely applicable for the detection of cancer micrometastases in lymph nodes. This method may lead to an earlier diagnosis and treatment of patients with subclinical lymph node metastasis.

Adult↗
PubMed1995

Suppression of v-Src transformation in primary rat embryo fibroblasts.

To understand the mechanism for resistance of primary cultures of rat embryo fibroblasts (REFs) to oncogene-induced transformation, we studied the transforming ability of a recombinant retrovirus, ZSV, containing v-src and neo genes in REFs and in the rat cell line F2408. The susceptibility of REFs to p60v-src transformation was markedly reduced when compared with that of F2408 cells, despite high levels of expression of functional p60v-src tyrosine kinase in the two systems. In hybrid cells obtained by somatic cell fusion between F2408 cells transformed by v-src and uninfected REFs, the transformed phenotype was suppressed despite persistent expression of p60v-src tyrosine kinase. On the other hand, hybrid cells between v-src transformed F2408 cells and uninfected F2408 cells retained the transformed phenotypes. These results indicate that primary cells possess an intracellular function(s) that cause suppression of the transformed phenotype induced by the v-src gene. In ZSV-infected REFs, tyrosine phosphorylation of cellular proteins, including p125 focal adhesion kinase, p70 paxillin and p130 was similar to that in the ZSV-infected F2408 cells, indicating that tyrosine phosphorylation of these proteins is not sufficient for the expression of transformed phenotype. On the other hand, cellular fibronectin and one of integrin receptors were downregulated in the ZSV-transformed F2408 cells but not in ZSV-infected REFs, suggesting that fibronectin and/or its receptor might play a role in suppressing v-src transformation in primary rat cells.

Animals↗
PubMed1995

Nitric oxide synthase inhibited by audouine in the rat brain.

Nitric oxide synthase (NOS) synthesizes nitric oxide (NO) from L-arginine (Arg) which has a guanidino group in its molecule. Audouine, a derivative of Arg, is the diguanidino compound. In this study, the effects of audouine on rat brain NOS activity were investigated by measuring nitrite and nitrate formation. Audouine inhibited NOS activity in a competitive (Ki = 2.10 microM) and partially uncompetitive (Ki = 49.7 microM) manner. Audouine is not substituted at the guanidino nitrogen, in contrast to most previously reported NOS inhibitors which were synthesized by substituting the guanidino nitrogen of Arg. Audouine is a novel inhibitor of NOS and should be useful for investigating the chemical nature of NOS and the roles of NO in the central nervous system.

Amino Acid Oxidoreductases↗
PubMed1995

Potential role of protein phosphorylation in GTP-gamma-S-dependent activation of phospholipase D.

Mammalian phospholipase D (PLD) is known to require nearly absolutely guanosine 5'-Q-3-thiotriphosphate (GTP-gamma-S) and a small G-protein for its activation. In streptolysin-Q-permeabilized HL-60 cells, phorbol ester or diacylglycerol enhanced greatly this PLD activation in the presence of ATP-Mg2+. Non-hydrolysable ATP analogue was inactive. This phorbol-ester-induced PLD activation was completely counteracted not only by protein kinase C (PKC) inhibitors but also by tyrosine kinase inhibitors. In cell-free lysates, the GTP-gamma-S-dependent activation of PLD was stimulated by ATP-Mg2+. This stimulation by ATP-Mg2+ did not respond to phorbol ester nor was it inhibited by PKC inhibitors, but was fully restrained by tyrosine kinase inhibitors. The results suggest that protein phosphorylation reactions by PKC and tyrosine kinase may take part, possibly in this order, in the small G-protein-coupled PLD activation.

Adenosine Triphosphate↗
PubMed1995

A eukaryotic gene encoding an endonuclease that specifically repairs DNA damaged by ultraviolet light.

Many eukaryotic organisms, including humans, remove ultraviolet (UV) damage from their genomes by the nucleotide excision repair pathway, which requires more than 10 separate protein factors. However, no nucleotide excision repair pathway has been found in the filamentous fungus Neurospora crassa. We have isolated a new eukaryotic DNA repair gene from N.crassa by its ability to complement UV-sensitive Escherichia coli cells. The gene is altered in a N.crassa mus-18 mutant and responsible for the exclusive sensitivity to UV of the mutant. Introduction of the wild-type mus-18 gene complements not only the mus-18 DNA repair defect of N.crassa, but also confers UV-resistance on various DNA repair-deficient mutants of Saccharomyces cerevisiae and a human xeroderma pigmentosum cell line. The cDNA encodes a protein of 74 kDa with no sequence similarity to other known repair enzymes. Recombinant mus-18 protein was purified from E.coli and found to be an endonuclease for UV-irradiated DNA. Both cyclobutane pyrimidine dimers and (6-4)photoproducts are cleaved at the sites immediately 5' to the damaged dipyrimidines in a magnesium-dependent, ATP-independent reaction. This mechanism, requiring a single polypeptide designated UV-induced dimer endonuclease for incision, is a substitute for the role of nucleotide excision repair of UV damage in N.crassa.

Amino Acid Sequence↗
PubMed1995

Essential aspartic acid residues, Asp-133, Asp-163 and Asp-164, in the transmembrane helices of a Na+/H+ antiporter (NhaA) from Escherichia coli.

The importance of negatively charged residues in transmembrane helices of many cation-coupled transporters has been widely demonstrated. Four Asp residues were located in the putative transmembrane helices of the Escherichia coli Na+/H+ antiporter, NhaA. We replaced each of these Asp residues by Asn in plasmid encoded nhaA and expressed these constructs in an E. coli mutant defective in both nhA and nhaB. Substitution of Asp-65 or Asp-282 (in the extramembrane region) had no effect on supporting the host mutant growth in the high NaCl- or LiCl-containing medium, and these two mutants had normal Na+/H+ and Li+/H+ antiporter activities. In contrast, substitution of Asp-133, Asp-163 or Asp-164 was detrimental to survival of the host mutant and impaired both Na+/H+ and Li+/H+ antiporter activities. These three Asp residues, conserved in the nhaA homologs from different species and which are located closely in the 3rd and 4th putative transmembrane helices, appear to play important roles in cation binding and transport.

Amino Acid Sequence↗
PubMed1995

Dibutyryl cyclic AMP protects Corynebacterium parvum-treated mice against lipopolysaccharide-induced lethal toxicity.

The effects of dibutyryl cyclic AMP (DBcAMP) on the lethal toxicity of lipopolysaccharide (LPS) were investigated in mice made hypersensitive to LPS by administration with Corynebacterium parvum (C. parvum). The peritoneal macrophages in C. parvum-treated mice released a conspicuous level of TNF alpha in response to LPS in vitro. These macrophages exhibited much higher susceptibility to LPS-induced cytotoxicity than with resident or peptone-induced macrophages. Pretreatment of the C. parvum-induced macrophages with DBcAMP significantly inhibited the TNF alpha production in response to LPS and decreased the susceptibility to LPS-induced cytotoxicity in vitro. Similar to the findings seen in in vitro experiments, in vivo administration with DBcAMP significantly inhibited the TNF alpha release in the sera of C. parvum-treated mice after LPS challenge and consequently decreased the susceptibility to LPS-induced shock. These results suggest that raising level of intracellular cAMP protects C. parvum-treated mice from hypersensitivity to lethal toxicity of LPS through downregulating TNF alpha synthesis.

Animals↗
PubMed1995

Microsatellite instability in Japanese gastric cancer.

BACKGROUND: Recent studies have shown that microsatellites are unstable in various types of cancers, and such genetic instability at the microsatellite loci (microsatellite instability) has been considered to play an important role in the development of cancer. However, the clinicopathologic significance of microsatellite instability in gastric cancer has not been clarified. METHODS: To elucidate the role of genetic instability in the development of gastric cancer, the presence of microsatellite instability was examined in 25 cases of gastric cancer using fresh-frozen tumor-normal paired samples using a polymerase chain reaction (PCR)-based method. Microsatellite instability was defined as tumors that showed altered banding patterns at two or more microsatellite loci. RESULTS: The incidence of microsatellite instability in gastric cancer cases was 4 of 25 patients (16%) and 4 of 26 cancers (15%). A significantly high incidence of microsatellite instability was observed in both the elderly (P < 0.01) and in lymph node metastasis-negative patients (P < 0.05). All patients with gastric cancer showing microsatellite instability were negative for lymphatic or venous permeation. A statistically significant association of microsatellite instability with no lymphatic permeation was thus observed (P < 0.05). CONCLUSIONS: This study revealed infrequent lymph node metastasis and lymph vessel invasion in the patients with gastric cancer demonstrating microsatellite instability. Although the number of examined cases was small, these findings suggest that gastric cancer that shows microsatellite instability may thus behave in a less malignant manner.

Chromosome Banding↗
PubMed1995

[Mycoplasma pneumonia found by the occurrence of atelectasis during the induction of anesthesia in a child with tetralogy of Fallot].

A 3-yr-old girl was scheduled to undergo surgical repair of tetralogy of Fallot. She had no sign or data indicating an infectious disease, other than a slight dry cough for a few days prior to the proposed operation. During the induction of anesthesia with nitrous oxide, oxygen and sevoflurane, transient moist rale was noticed with a precordial stethoscope. Her trachea was intubated without any difficulty after the administration of pancuronium, followed by a chest auscultation, which revealed vesicular sound bilaterally but no rale. However, a chest X-ray taken after the right subclavian vein catheterization showed a massive hypoaeration in the upper left pulmonary region. The presence of the right-to-left intracardiac shunt made it impossible to detect the occurrence of atelectasis by a decrease in SpO2. Fiberoptic bronchoscopy showed no obstruction of the bronchus and no hypersecretion initially, but physical therapy and humidification made it possible to aspirate intratracheal sputum. Because there seemed to be an imbalance between the relatively uneventful induction of anesthesia and the relative resistance of atelectasis to authentic therapies, the operation was postponed, and the antibody to mycoplasma pneumoniae was titrated. The titer in the serum was 1:80, and increased to 1:560 6 days later. Chest X-rays revealed normal lung condition 3 days later, and she was given erythromycin, 800 mg.day-1 for 2 weeks. We conclude that we should be alert to possible asymptomatic mycoplasma infection, which potentially makes patients susceptible to atelectasis during the perioperative period.

Anesthesia, Inhalation↗
PubMed1995

Effects of transient forebrain ischemia on long-term enhancement of dopamine release in rat striatal slices.

We studied the effects of transient forebrain ischemia in vivo on long-term enhancement of dopamine (DA) release from rat striatal slices. One hour after the high-frequency tetanic stimulation (HFTS) or L-glutamate (10(-6) M) application in Mg(2+)-free medium to striatal slices, the high concentration of KCl (high K+)-evoked DA release was measured. Tetanic stimulation or L-glutamate application significantly potentiated the high-K(+)-evoked DA release. When striatal slices were prepared from rats exposed to 3 min of ischemia followed by 24-h survival, the enhancement of DA release by HFTS was unaffected by ischemia. In contrast, the enhancement of DA release by HFTS was impaired in rats exposed to 5 min or 10 min of ischemia. In addition, high K(+)-evoked DA release per se was significantly impaired by 10 min of ischemia. The enhancement of DA release elicited by pretreatment with L-glutamate was also impaired in the rats exposed to 5 min of ischemia. When striatal slices were prepared from rats exposed to 5 min of ischemia with 7-day survival, the enhancement of DA release by HFTS was still impaired. The present results indicate that the neuronal mechanisms of the enhancement of DA release may be more sensitive to impairment from short periods of ischemia. Furthermore, the results suggest that an impairment of long-term enhancement of DA release by ischemia may be related the dysfunction of motor performance in rats exposed to ischemia.

Animals↗