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Biomedical subjects

H Inoue

Publications and source records attributed to H Inoue.

At least 145 records · Page 8Linked to original sources
PubMed2001

Push-out testing and histological evaluation of glass reinforced hydroxyapatite composites implanted in the tibia of rabbits.

In vitro and in vivo bioactivity studies were performed to assess the biocompatibility of CaO-P2O5 glass-reinforced hydroxyapatite (GR-HA) composites. The ability to form an apatite layer by soaking in simulated body fluid (SBF) was examined and surfaces were characterized using FTIR reflection and thin-film X-ray diffraction analyses. Qualitative histology, histomorphometric measurements, and push-out testing were performed in a rabbit model for characterizing bone/implant bonding. Under the in vitro conditions using SBF, an apatite layer could not be formed on GR-HA composites within 8 weeks. Results of push-out testing showed bonding between the composites and bone, ranging from 130-145 N after 2 weeks of implantation. After the longest implantation period, 16 weeks, the GR-HA composite prepared with the higher content of CaO-P2O5 glass showed the highest bonding force, 606 +/- 45 N, compared to 459 +/- 30 N for sintered HA. Development of immature bone and modifications in the turnover of a more mature bone on the surface of GR-HA composites were similar to those on sintered HA.

Animals↗
PubMed2001

Apolipoprotein E genotype, serum lipids, and colorectal adenomas in Japanese men.

We examined the relation of serum lipids and apolipoprotein E genotype to colorectal adenomas among 205 cases and 220 controls with normal colonoscopy in Japanese men. With adjustment for body mass index, cigarette smoking, alcohol use, and other covaiates, odds ratios of proximal and distal adenomas associated with the presence of an allele varepsilon4 were 0.59 (95% confidence interval 0.23-1.45) and 0.99 (0.50-1.98), respectively. While serum total and LDL cholesterol were unrelated to both proximal and distal adenomas, serum triglycerides were positively related to distal adenomas. The findings suggest that altered lipid metabolism may be differentially associated with tumorigenesis in the proximal and distal colorectum.

Adenoma↗
PubMed2001

WFS1 (Wolfram syndrome 1) gene product: predominant subcellular localization to endoplasmic reticulum in cultured cells and neuronal expression in rat brain.

Wolfram (DIDMOAD) syndrome is an autosomal recessive neurodegenerative disorder accompanied by insulin-dependent diabetes mellitus and progressive optic atrophy. Recent positional cloning led to identification of the WFS1 (Wolfram syndrome 1) gene, a member of a novel gene family of unknown function. In this study, we generated a specific antibody against the C-terminus of the WFS1 protein and investigated its subcellular localization in cultured cells. We also studied its distribution in the rat brain. Biochemical studies indicated the WFS1 protein to be an integral, endoglycosidase H-sensitive membrane glycoprotein that localizes primarily in the endoplasmic reticulum (ER). Consistent with this, immunofluorescence cell staining of overexpressed WFS1 showed a characteristic reticular pattern over the cytoplasm and overlapped with the ER marker staining. No co-localization of WFS1 with mitochondria argues against an earlier clinical hypothesis that Wolfram syndrome is a mitochondria-mediated disorder. In the rat brain, at both the protein and mRNA level, WFS1 was found to be present predominantly in selected neurons in the hippocampus CA1, amygdaloid areas, olfactory tubercle and superficial layer of the allocortex. These expression sites, i.e. components of the limbic system or structures closely associated with this system, may be involved in the psychiatric, behavioral and emotional abnormalities characteristic of this syndrome. ER localization of WFS1 suggests that this protein plays an as yet undefined role in membrane trafficking, protein processing and/or regulation of ER calcium homeostasis. These studies represent a first step toward the characterization of WFS1 protein, which presumably functions to maintain certain populations of neuronal and endocrine cells.

Animals↗
PubMed2001

Angiopoietin-2 is related to tumor angiogenesis in gastric carcinoma: possible in vivo regulation via induction of proteases.

Tumor angiogenesis progresses by a dynamic balance between tumor vascular regression and growth. Angiopoietin (Ang)-2 (the natural antagonist for the angiogenic Tie-2 receptor) and vascular endothelial growth factor (VEGF) are thought to be critical regulators in this process; therefore, these may play a critical role in cancer aggressiveness. The aim of this study was to clarify the clinical and biological significance of the expression of Ang-2 in human gastric cancers and to investigate the relationship between Ang-2 together with VEGF and the induction of proteases such as matrix metalloproteinases (MMPs) in the process of tumor development. Eighty-five individuals with gastric cancer, who had undergone surgery without preoperative treatment, were studied. A stable transfectant of the human MKN-7 gastric cancer cell lines with an Ang-2 expression vector was used for the experimental study. First, we examined the relationship between the mRNA expression of Angs by Northern blot analysis and clinicopathological features. High Ang-2-expression cases showed more frequent vascular involvement and more advanced stages of disease compared with low Ang-2-expression cases (P < 0.05). With regard to prognosis, the survival time for patients in the high-Ang-2 mRNA group was significantly shorter (P < 0.05). When we examined the localization of Ang-2 in human gastric cancers, immunohistochemical analysis revealed that this protein was expressed predominantly in cancer tissues when compared with normal tissues. Interestingly it was expressed not only in endothelia cells (ECs) but also in cancer cells. Second, Ang-2-transfected cells were implanted in vivo into the gastric walls of nude mice. Ang-2-transfectant mice developed highly metastatic tumors with hypervascularity as compared with MKN-7 or control vector-transfectant tumors. There was a significant correlation between Ang-2 mRNA expression and lower grade of vessel maturation. Third, on the basis of the in vivo data, we focused on production of proteases such as MMPs to investigate possible mechanisms in these processes. MMP-1, MMP-9, and urokinase-type plasminogen activator in ECs were strongly up-regulated by Ang-2 in the presence of VEGF in vitro. These data suggest that production of Ang-2 is implicated in tumor development in human gastric cancers. Its production may contribute to tumor angiogenesis by induction of proteases in ECs, which may be enhanced in the presence of VEGF.

Angiopoietin-2↗
PubMed2001

Glutathione S-transferase polymorphisms and risk of colorectal adenomas.

Glutathione S-transferases (GSTs) are a superfamily of detoxification enzymes that may play an important role in human carcinogenesis. While the genetic polymorphisms GSTM1 and GSTT1 have drawn particular interest in relation to cancer susceptibility, previous studies of colorectal cancer are inconsistent regarding their role. We examined the relation between GSTM1 and GSTT1 genotypes combined and colorectal adenomas, and the interaction with cigarette smoking among 205 cases of colorectal adenomas and 220 controls with normal total colonoscopy in Japanese men. Neither GSTM1 nor GSTT1 was related to colorectal adenomas, nor were the null genotypes of GSTM1 and GSTT1 combined. The lack of an association with GSTM1 and GSTT1 genotypes combined persisted even when the analysis was done separately for proximal and distal colorectal adenomas. A three- to fivefold significant increase in the odds of colorectal adenomas was observed among men with a high exposure to cigarette smoking across the genotype groups, and a statistically significant increasing trend was noted within each genotype group. The present findings do not support the role for GSTM1 and GSTT1 genotypes in the development of colorectal adenomas.

Adenoma↗
PubMed2001

Blood concentrations of tetracaine and its metabolite following spinal anesthesia.

Blood concentrations of tetracaine and its metabolite, p-butylaminobenzoic acid, were measured after spinal anesthesia with tetracaine which had been administered to patients under going orthopedic surgery. Tetracaine, an ester anesthetic, was given to 10 patients, the dose was 8-14mg, and blood samples were collected 1, 2 and 6h after the injection of tetracaine. We used gas chromatography/mass spectrometry for purposes of analysis. Tetracaine was not detected in any blood sample, but the metabolite was detected in each sample with the mean concentrations of 126.5, 97.9 and 43.3ng/ml at 1, 2 and 6h, respectively. This data will be useful in determination of the cause of death after spinal anesthesia with tetracaine.

4-Aminobenzoic Acid↗
PubMed2001

Enhancement of human cord blood CD34+ cell-derived NK cell cytotoxicity by dendritic cells.

NK cells and dendritic cells (DCs) are both important in the innate host defense. However, the role of DCs in NK cell-mediated cytotoxicity is unclear. In this study, we designed two culture systems in which human cord blood CD34(+) cells from the same donor were induced to generate NK cells and DCs, respectively. Coculture of the NK cells with DCs resulted in significant enhancement of NK cell cytotoxicity and IFN-gamma production. However, NK cell cytotoxicity and IFN-gamma production were not increased when NK cells and DCs were grown together separated by a transwell membrane. Functional studies demonstrated that 1) concanamycin A, a selective inhibitor of perforin/granzyme B-based cytolysis, blocked DC-stimulated NK cytotoxicity against K562 cells; and 2) neutralizing mAb against Fas ligand (FasL) significantly reduced DC-stimulated NK cytotoxicity against Fas-positive Jurkat cells. In addition, a marked increase of FasL mRNA and FasL protein expression was observed in DC-stimulated NK cells. The addition of neutralizing mAb against IL-18 and IL-12 significantly suppressed DC-stimulated NK cell cytotoxicity. Neutralizing IFN-gamma Ab almost completely inhibited NK cell cytotoxicity against Jurkat cells. These observations suggest that DCs enhance NK cell cytotoxicity by up-regulating both perforin/granzyme B- and FasL/Fas-based pathways. Direct interaction between DCs and NK cells is necessary for DC-mediated enhancement of NK cell cytotoxicity. Furthermore, DC-derived IL-18 and IL-12 were involved in the up-regulation of NK cell cytotoxicity, and endogenous IFN-gamma production plays an important role in Fas-mediated cytotoxicity.

Anti-Bacterial Agents↗
PubMed2001

Pharmacological profile of T-1032, a novel specific phosphodiesterase type 5 inhibitor, in isolated rat aorta and rabbit corpus cavernosum.

This study was designed to examine the pharmacological properties of T-1032 (methyl-2-(4-aminophenyl)-1,2-dihydro-1-oxo-7-(2-pyridinylmethoxy)-4-(3,4,5-trimethoxyphenyl)-3-isoquinoline carboxylate sulfate), a novel phosphodiesterase type 5 inhibitor, in isolated rat aorta and rabbit corpus cavernosum. T-1032 (3x10(-11) to 3x10(-7) M) caused an endothelium-dependent relaxation in the isolated rat aorta precontracted with phenylephrine, and the relaxation was accompanied by an increase in cGMP but not cAMP levels. The T-1032-induced relaxation was attenuated by N(G)-nitro-L-arginine methyl ester (L-NAME) (10(-3) M), a nitric oxide (NO) synthase inhibitor, or 1H-[1,2,4]oxadiazolo[4,3-alpha]quinoxalin-1-one (ODQ) (10(-5) M), a guanylyl cyclase inhibitor. T-1032 (10(-9), 10(-8) M) produced a potentiation of the relaxation induced by sodium nitroprusside, but not of the relaxation induced by isoproterenol. In the isolated rabbit corpus cavernosum precontracted with phenylephrine, the electrical field stimulation-induced relaxation was attenuated by treatment with tetrodotoxin (10(-6) M) as well as L-NAME (10(-4) M). The L-NAME-inhibited relaxation was restored by treatment with L-arginine (5x10(-4) M). T-1032 (10(-9) to 10(-6) M) and sildenafil (10(-9) to 10(-6) M) produced a potentiation of the electrical field stimulation-induced relaxation as well as a decrease in basal tension in a concentration-dependent manner. It was concluded that T-1032 had potentiating effects on the NO/cGMP signaling pathway in isolated tissues, probably through specific blockade of phosphodiesterase type 5. T-1032 would be a useful compound to examine the physiologic functions of phosphodiesterase type 5 in mammalian tissues.

3',5'-Cyclic-GMP Phosphodiesterases↗
PubMed2001

Preoperative diagnosis of intraductal papillary-mucinous tumors of the pancreas with attention to telomerase activity.

BACKGROUND: It has been reported that, in patients with intraductal papillary-mucinous tumor (IPMT) of the pancreas, it is difficult to distinguish adenoma from carcinoma preoperatively. Recently, it has also been reported that telomerase activity was detected in many patients with carcinoma. In this report, the authors used the method of telomerase repeat amplification protocol (TRAP) assay on pancreatic juice retrieved by endoscopic retrograde pancreatic juice aspiration (ERP aspiration). METHODS: Pancreatic juice was collected from 28 patients (13 with intraductal carcinoma and 15 with adenoma) using ERP aspiration at either Hiroshima University Hospital or its affiliated hospitals. Two samples of pancreatic juice were collected from each patient. Each sample was examined by cytology for Papanicolaou staining and TRAP assay. RESULTS: Four of 13 IPMT patients (31%) with intraductal carcinoma were diagnosed accurately by cytology. Seven of nine patients who were classified with benign tumors by cytologic assessment had tumors that expressed telomerase activity. Overall, 11 of 13 IPMT patients (85%) with intraductal carcinoma were diagnosed correctly by cytology associated with telomerase activity. All of the IPMT patients with adenoma were classified with benign tumors by cytologic assessment, and telomerase activity was not expressed. CONCLUSIONS: In this study, the authors found that telomerase activity was expressed with a comparatively high probability in intraductal carcinoma. These results suggest that telomerase activity in pancreatic juices may be used as an adjunct to cytologic diagnosis and may aid further in distinguishing between benign IPMT and malignant IPMT of the pancreas preoperatively.

Adenocarcinoma, Mucinous↗
PubMed2001

Detection of the "midband" lipoprotein in patients with coronary artery spasm.

BACKGROUND: Dyslipidemia in patients with coronary vasospasm has been characterized by a low level of high-density lipoprotein (HDL) cholesterol without elevation of low-density lipoprotein (LDL) cholesterol, distinct from patients with organic coronary artery disease. HYPOTHESIS: Disordered triglyceride-rich lipoprotein metabolism may be linked to the genesis of coronary artery spasm. METHODS: The incidence of the "midband" lipoprotein observed between very low-density lipoprotein (VLDL) and LDL bands in the polyacrylamide disc gel electrophoretic analysis was determined in 48 patients with coronary spastic angina (CSA), in 50 patients with stable effort angina and a significant fixed coronary stenosis (SEA), and in 40 control subjects without coronary artery disease (Control). RESULTS: The incidence was significantly (p<0.05) higher in CSA (71%) than in SEA (50%) and Control (25%). Smoking was significantly (p < 0.05) more prevalent in CSA (77%) than in SEA (50%) and Control (50%). In SEA, serum levels of triglyceride and apoproteins C-II, C-III, and E were all significantly higher, and the serum level of HDL cholesterol was significantly lower in the midband-positive than in the midband-negative subgroup. In CSA, no significant differences were found in these serum levels between the midband-positive and -negative subgroups, except for a significantly (p < 0.05) lower level of HDL cholesterol in the former. However, a significantly (p < 0.05) higher incidence of diabetes mellitus or impaired glucose tolerance was noted in the midband-positive (41%) than in the midband-negative subgroup (7%) in CSA. The incidence of the detected midband lipoprotein was significantly decreased in the blood samples obtained from 20 of CSA after a > 6-month angina-free period (70-->25%, p < 0.05). CONCLUSIONS: The midband lipoprotein was frequently detected in patients with coronary vasospasm, suggesting that dyslipidemia with disordered triglyceride-rich lipoprotein metabolism may be linked to the genesis of coronary artery spasm.

Adult↗
PubMed2001

Exclusion of SMAD4 mutation as an early genetic change in human pancreatic ductal tumorigenesis.

Pancreatic ductal carcinoma is one of the malignant diseases with the poorest prognosis. To develop effective methods for better treatment of pancreatic cancer patients, we tried to analyze the course of multistep carcinogenesis of the pancreatic ductal cells. IPMT (intraductal papillary-mucinous tumor) is thought to be one of the premalignant lesions of the pancreas, which would transform into carcinomas. Loss of 18q at the SMAD4 locus is known to be an early genetic change in pancreatic ductal carcinomas. It is not clear, however, whether or not the target gene for inactivation is SMAD4. Using 18 IPMTs, we analyzed LOH at the SMAD4 locus and observed frequent LOH (7/14, 50%). No mutations were observed in any of the tumors. Moreover, the expression level of the SMAD4 protein did not show a reduction in IPMTs. These results suggested that (i) inactivating mutation of the SMAD4 gene is a rather late genetic change in pancreatic carcinogenesis, and (ii) there may be an unknown tumor suppressor gene in 18q, other than SMAD4, that is involved in pancreatic ductal carcinogenesis.

Carcinoma, Pancreatic Ductal↗
PubMed2001

A recurrent large Alu-mediated deletion in the hypoxanthine phosphoribosyltransferase (HPRT1) gene associated with Lesch-Nyhan syndrome.

We identified the identical large genomic deletion in the hypoxanthine phosphoribosyltransferase (HPRT1) gene in two Japanese patients with Lesch-Nyhan (LN) syndrome. This deletion spanned from an Alu sequence in the promoter region to another Alu-sequence in intron 1, a length of 2,969 base pairs including exon 1. In order to ask whether this deletion was a recurrent mutation, we developed a simple alternative method to determine the separate origin of the HPRT1 mutation of the patients as assessed with an apparent mtDNA polymorphism. Considering that an LN syndrome-causing mutation is not transmitted from patient to offspring as LN syndrome is a fatal disease in childhood and that mtDNA is maternally inherited, HPRT1 mutations and mtDNA would be co-transmitted from carrier mother to offspring since both appeared in females. Two bases were different in the hypervariable region I of the mtDNA between the two patients, indicating the separate origin of their mtDNA over at least several thousand years as calculated based on the molecular evolution rate in this region. We thus conclude that the identical deletion found in HPRT1 of the two patients was derived from recurrent events of genomic recombination. Given that the same Alu-mediated deletion of HPRT1 has not been reported among somatic mutations at the same locus, this region of the HPRT1 gene flanked by Alu-sequences is likely a mutational hot spot in the germline but not in somatic cells. In addition, we also report novel LN-syndrome-conferring mutations in intron 6 (IVS6+1G --> C) and intron 8 (IVS7-9T --> G) that resulted in exclusions of exon 6 and exon 8, respectively.

Alternative Splicing↗
PubMed2001

Divergence and convergence of TGF-beta/BMP signaling.

The transforming growth factor-beta (TGF-beta) superfamily includes more than 30 members which have a broad array of biological activities. TGF-beta superfamily ligands bind to type II and type I serine/threonine kinase receptors and transduce signals via Smad proteins. Receptor-regulated Smads (R-Smads) can be classified into two subclasses, i.e. those activated by activin and TGF-beta signaling pathways (AR-Smads), and those activated by bone morphogenetic protein (BMP) pathways (BR-Smads). The numbers of type II and type I receptors and Smad proteins are limited. Thus, signaling of the TGF-beta superfamily converges at the receptor and Smad levels. In the intracellular signaling pathways, Smads interact with various partner proteins and thereby exhibit a wide variety of biological activities. Moreover, signaling by Smads is modulated by various other signaling pathways allowing TGF-beta superfamily ligands to elicit diverse effects on target cells. Perturbations of the TGF-beta/BMP signaling pathways result in various clinical disorders including cancers, vascular diseases, and bone disorders.

Animals↗
PubMed2001

Effects of nitric oxide synthase inhibitors on vascular hyperpermeability with thermal injury in mice.

The role of nitric oxide and related synthase in thermal injury was investigated by using models of experimental burn to evaluate severity from the aspect of vascular permeability. Thermal injuries were produced in the murine right ear by pinching with a pair of preheated tweezers. Immediately thereafter, Evans blue dye was intravenously administered, and the mice injured with burns were sacrificed at various times. The burned ears were collected and hydrolyzed, and the level of extracted dye was measured as an indicator of inflammation. Vascular hyperpermeability was suppressed by the administration of nitric oxide synthase inhibitors. LNAME not only suppressed vascular hyperpermeability in thermal injuries in a dose-dependent manner but was also effective with either prophylactic or therapeutic administration. Although aminoguanidine also suppressed the inflammatory response, it had no effect on the early inflammatory phase. Nitric oxide synthase is well known to have two types of isozymes. Aminoguanidine, an inhibitor specific to inducible nitric oxide synthase, suppressed the late phase 6 h after injury, suggesting that inducible nitric oxide synthase is involved in inflammatory responses of thermal injuries. These results also demonstrated that inducible nitric oxide synthase-like protein stained the burned region immunohistochemically. Therefore, both types of enzymes mediating nitric oxide affect inflammatory responses, i.e., vascular hyperpermeability, and their regulation may lead to the development of new therapy for thermal injuries.

Animals↗
PubMed2001

Adequate endoscopic mucosal resection for early gastric cancer obtained from the dissecting microscopic features of the resected specimens.

BACKGROUND: We have employed endoscopic mucosal resection (EMR), using a cap-fitted panendoscope (EMRC), for early gastric cancer since 1992. The presence of an adequate surgical margin is a requirement because of the radicality of EMR, and dissecting microscopic examination is useful in regard to the diagnosis of spread of the disease. METHODS: To devise an adequate method of EMR that allows no lateral residue, we examined gastric mucosal specimens obtained by EMRC. One hundred and sixty-seven specimens from 97 lesions in 85 patients treated by EMRC were examined in regard to characteristic features, the recovery of marks made around the lesion, and the frequency of residue, and comparisons were made between the dissecting microscopic and histopathological findings. RESULTS: The first specimen obtained with a large cap under full suction was a circular shape measuring 21 x 19mm. The second specimen from fractionated resection was a half-moon or crescent shape, and the third specimen had a ginkgo leaflike or irregular shape. In the elevated lesions, coincidence regarding the spread, as determined by dissecting microscopy and histopathology, was present in 62 (93%) of the 67 lesions. In 16 (53%) of 30 flat or depressed lesions, there was a difference of 2 to 5 mm between the spread determined by these two examinations. CONCLUSION: It is important to place an adequate number of marks around the lesion and recover all marks by resection. When an elevated lesion measures 15mm or more, and a flat or depressed lesion is not clearly demarcated, aggressive use of planned fractionated resection seems to be the best way to prevent a lateral residue in EMR.

Aged↗
PubMed2001

An investigation of cell proliferation and soluble mediators induced by interleukin 1beta in human synovial fibroblasts: comparative response in osteoarthritis and rheumatoid arthritis.

OBJECTIVES AND DESIGN: The difference in cell proliferation and release of soluble factors in response to interleukin 1beta (IL-1beta) in fibroblasts obtained from patients with osteoarthritis (OA) and rheumatoid arthritis (RA) and from normal skin has been investigated. TREATMENT: The cells were treated with recombinant IL-1beta in the presence or absence of pharmacological agents for 24 h or 48 h. METHODS: Cell proliferation was examined by WST-1 assay, and the amounts of interleukin-6 (IL-6), interleukin-8 (IL-8), macrophage colony stimulating factor (M-CSF), vascular endothelial growth factor (VEGF), matrix metalloproteinase-1 (MMP-1), and prostaglandin E2 (PGE2) were measured by enzyme linked immunosorbent assay (ELISA). RESULTS: IL-1beta dose-dependently enhanced the proliferation of all fibroblasts. The proliferative response to IL-1beta in RA synovial fibroblasts was greater than that in OA synovial and skin fibroblasts. However, there was no difference in spontaneous levels of soluble factors between OA and RA fibroblasts, though medium concentrations of IL-1beta-released VEGF, MMP-1, and PGE2, but not cytokines, in RA were slightly higher than those in OA. Ability to release soluble mediators was pronouncedly increased at 3 h to 9 h after stimulating fibroblasts with IL-1beta for 1 h. The proliferative response to IL-1beta in all fibroblasts was inhibited by dexamethasone and the NF-kappaB inhibitor hymenialdisine but not the cyclooxygenase 2 (COX-2) inhibitor NS-398. But PGE2 prevented proliferation of RA fibroblasts when added to medium up to 3 h after IL-1beta stimulation. Dexamethasone also inhibited the release of IL-6, IL-8, and PGE2 induced by IL-1beta in both OA and RA fibroblasts. NS-398 exhibited an inhibition of IL-1beta-induced IL-6 production as well as PGE2 production. Hymenialdisine inhibited IL-6 production and reduced IL-8 production dependent on synovial cell strains. Methotrexate had no effect on the response to IL-1beta in synovial fibroblasts. CONCLUSION: The present results indicate that the activation of NF-kappaB plays an important role in the proliferative response to IL-1beta in human fibroblasts, and suggest that PGE2 acts as a modulator of cell proliferation in inflamed synovial tissue. It appears that the ability to produce soluble factors in RA synovial fibroblasts is not intrinsic. However, the response to IL-1beta in RA cells seems to be greater than that in OA cells.

Arthritis, Rheumatoid↗