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Biomedical subjects

H Yoshida

Publications and source records attributed to H Yoshida.

At least 127 records · Page 7Linked to original sources
PubMed2002

Ultrasound-guided surgical drainage of face and neck abscesses.

An ultrasound-guided surgical drainage technique in which grey-scale and colour Doppler ultrasonography were combined is described. The technique was performed for eight deep subcutaneous abscesses subsequent to odontogenic infection, and provided easy detection and accurate, reliable penetration of abscesses that were difficult to locate by physical examination. Colour Doppler ultrasonography is particularly useful for differentiating blood vessels from the static space of abscesses.

Abscess↗
PubMed2002

Weak response of helicobacter pylori antibody is high risk for gastric cancer: a cross-sectional study of 10,234 endoscoped Japanese.

BACKGROUND: A large number of endoscoped members of the general Japanese population were surveyed to investigate the relationship between Helicobacter pylori infection and gastric cancer. Special attention was given to antibody titer and age of the subjects. METHODS: We performed gastrointestinal endoscopy and measured serum anti-H. pylori antibody in 10,234 consecutive Japanese who participated in a health examination program. Gastric cancer, when suspected, was confirmed by histology. We graded the H. pylori antibody titer into three groups in accordance with optical density values by ELISA: 'strongly positive', 'weakly positive', and 'negative'. RESULTS: Among the 10,234 subjects (men/women, 7.021/3,213; mean age, 49.1 years), 4,909 (48%) were strongly positive, 1,750 (17%) were weakly positive, and 3,575 (35%) were negative for H. pylori antibody. Thirty-seven cases of gastric cancer were found among the 10,234 subjects (0.36%); 23/4,909 (0.47%) in the strongly positive group, 9/1,750 (0.51%) in the weakly positive group, and 5/3,575 (0.14%) in the negative group. Both the strongly and weakly positive groups showed a higher risk of gastric cancer than the negative group. In the subjects over age 60, the weakly positive group seemed to show the highest risk for gastric cancer. CONCLUSIONS: In this investigation of 10,234 Japanese, based on endoscopy results, those with serum H. pylori antibody had an increased risk for gastric cancer, while those 'weakly positive' showed a high risk, particularly in the elderly.

Antibodies, Bacterial↗
PubMed2002

Localization of [14C]clarithromycin in rat gastric tissue when administered with lansoprazole and amoxicillin.

After oral and intravenous administration of [14C]clarithromycin to rats, c. 60-70% of the radioactivity in the gastric tissue was found to be distributed in the mucosal layer. Co-administration of lansoprazole and amoxicillin had no apparent effect on this distribution pattern of [14C]clarithromycin. The amount of unchanged [14C]clarithromycin in gastric contents increased with co-administration of lansoprazole and amoxicillin. Microautoradiograms of the gastric mucosa showed that [14C]clarithromycin was highly distributed in the mucous layer and in surface epithelial cells following oral administration. Homogeneous distribution of radioactivity was evident in the fundic gland. With iv administration, [14C]clarithromycin seemed to be secreted by both secreting cells in the gland base and surface epithelial cells.

2-Pyridinylmethylsulfinylbenzimidazoles↗
PubMed2002

Analysis of apoptotic and antiapoptotic signalling pathways induced by Helicobacter pylori.

BACKGROUND AND AIMS: Although it is reported that Helicobacter pylori induces apoptosis on gastric epithelial cells, the mechanism remains unknown. Antiapoptotic effects generated by H pylori have not yet been evaluated. METHODS: (1) H pylori strains (type 1 wild, TN2-DeltacagE, TN2-DeltavacA) were cocultured with MKN45, TMK1, and HeLa cells, and cell viability and apoptosis were assessed by trypan blue exclusion and DNA laddering, respectively. (2) Activation of caspases-3, 7, and 8, cytochrome c release from the mitochondria, and Fas, Fas associated death domain protein (FADD), Bax, Bak, and Bcl-X expression were evaluated by immunoblot analysis. (3) To investigate whether nuclear factor kappa B (NFkappaB) activation induced by cag pathogenicity island (PAI) positive H pylori affects antiapoptosis, MKN45 cells stably expressing super-repressor Ikappabetaalpha were cocultured with H pylori, and cell viability and caspase activation were evaluated. NFkappaB regulated gene expression was also evaluated by ribonuclease protection assay. RESULTS: (1) Wild-type and DeltavacA mutant H pylori induced apoptosis more potently than the DeltacagE mutant. Inhibition of cell contact between H pylori and cancer cells and heat killing H pylori diminished cell death. (2) Caspases-3, 7, and 8 were activated time dependently by H pylori as well as by the agonist anti-Fas. Cytochrome c release from mitochondria was observed and was not inhibited by caspase-8 inhibitor. Although protein expression of Fas, FADD, Bax, Bak, and Bcl-X in the whole cell lysates was not changed by H pylori, Bax was decreased from mitochondria free cytosol suggesting that Bax was translocated into mitochondria. (3) Cell death and the activities of caspases-3 and 8 were promoted in MKN45 cells stably expressing super-repressor Ikappabetaalpha that inhibits NFkappaB activation. Antiapoptotic proteins c-IAP1 and c-IAP2 were upregulated by the wild-type strains. CONCLUSION: cag PAI positive H pylori is capable of inducing apoptotic effects mainly through the mitochondrial pathway. Antiapoptotic effects mediated by NFkappaB activation were also observed.

Adaptor Proteins, Signal Transducing↗
PubMed2002

Analysis of apoptotic and antiapoptotic signalling pathways induced by Helicobacter pylori.

BACKGROUND AND AIMS: Although it is reported that Helicobacter pylori induces apoptosis on gastric epithelial cells, the mechanism remains unknown. Antiapoptotic effects generated by H pylori have not yet been evaluated. METHODS: (1) H pylori strains (type 1 wild, TN2-deltacagE, TN2-deltavacA) were cocultured with MKN45, TMK1, and HeLa cells, and cell viability and apoptosis were assessed by trypan blue exclusion and DNA laddering, respectively. (2) Activation of caspases-3, 7, and 8, cytochrome c release from the mitochondria, and Fas, Fas associated death domain protein (FADD), Bax, Bak, and Bcl-X expression were evaluated by immunoblot analysis. (3) To investigate whether nuclear factor kappa B (NFkappaB) activation induced by cag pathogenicity island (PAI) positive H pylori affects antiapoptosis, MKN45 cells stably expressing super-repressor IkappaBalpha were cocultured with H pylori, and cell viability and caspase activation were evaluated. NFkappaB regulated gene expression was also evaluated by ribonuclease protection assay. RESULTS: (1) Wild-type and deltavacA mutant H pylori induced apoptosis more potently than the deltacagE mutant. Inhibition of cell contact between H pylori and cancer cells and heat killing H pylori diminished cell death. (2) Caspases-3, 7, and 8 were activated time dependently by H pylori as well as by the agonist anti-Fas. Cytochrome c release from mitochondria was observed and was not inhibited by caspase-8 inhibitor. Although protein expression of Fas, FADD, Bax, Bak, and Bcl-X in the whole cell lysates was not changed by H pylori, Bax was decreased from mitochondria free cytosol suggesting that Bax was translocated into mitochondria. (3) Cell death and the activities of caspases-3 and 8 were promoted in MKN45 cells stably expressing super-repressor IkappaBalpha that inhibits NFkappaB activation. Antiapoptotic proteins c-IAP1 and c-IAP2 were upregulated by the wild-type strains. CONCLUSION: cag PAI positive H pylori is capable of inducing apoptotic effects mainly through the mitochondrial pathway. Antiapoptotic effects mediated by NFkappaB activation were also observed.

Apoptosis↗
PubMed2002

Experimental nephropathy induced by Haemophilus parainfluenzae antigens.

BACKGROUND: We have demonstrated that outer membrane antigens of Haemophilus parainfluenzae (OMHP) are potentially involved in IgA nephropathy (IgAN). In this study, we established an experimental model of IgAN using OMHP antigens and investigated the nephritogenicity of OMHP antigens. METHODS: One hundred and twenty C3H/HeN mice were administered OMHP antigens orally (PO group) or intraperitoneally (IP group). Mice were sacrificed at 10, 20, 30, 40, and 50 weeks of age to examine sequential glomerular changes and to measure levels of IgG, IgA, and IgM antibody against OMHP by ELISA. RESULTS: Glomerular deposition of IgA and increases in the amount of mesangial matrix were observed in the PO group and the IP group from 40 and 30 weeks of age, respectively. Mice in both groups showed glomerular deposition of OMHP antigens from 30 or 40 weeks of age. Levels of IgA antibodies against OMHP were significantly increased in the PO and IP groups compared with controls. There was a significant correlation between mesangial proliferation and glomerular deposition of IgA. CONCLUSIONS: Administration of OMHP antigens to mice may induce glomerular deposition of IgA and mesangial proliferation, resembling the changes seen in IgAN, with increases in IgA antibodies against OMHP antigens. This is the first use of OMHP antigens to establish an active model of IgAN.

Animals↗
PubMed2002

Association of parvovirus B19 infection with acute glomerulonephritis in healthy adults: case report and review of the literature.

An otherwise healthy 20-year-old woman presented with an erythematous rash on her face as well as arthralgia and anemia. She also had systemic edema, proteinuria and hypertension. Laboratory data on admission showed hypocomplementemia, human parvovirus B 19 (HPV) DNA and both immunoglobulin (Ig) M and IgG antibodies to HPV in her serum. Renal biopsy specimens showed features of endocapillary glomerulonephritis under light microscopy. Electron microscopy showed massive subendothelial electron-dense deposits. No cause was probable other than immune complex-mediated glomerulonephritis associated with HPV infection. In a review of this and similar cases reported in the literature, several characteristic features come to light: female dominance, onset in the second or third decade of life, hypocomplementemia, histologic renal endocapillary and/or mesangioproliferative glomerulonephritis with subendothelial deposits and spontaneous recovery.

Adult↗
PubMed2002

Acute renal failure and hearing loss due to sodium bromate poisoning: a case report and review of the literature.

Acute renal failure with hearing loss due to sodium bromate intoxication is described. A 48-year-old woman who ingested permanent wave neutralizer in a suicide attempt and developed anuria was admitted to our hospital for hemodialysis. Bromate intoxication was suspected and hemodialysis was carried out; she required maintenance dialysis 3 times a week. Irreversible severe sensorineural hearing loss continued and peripheral polyneuropathy developed in the lower limbs. We measured the concentration of bromine in the serum before and after the first hemodialysis and found its removal rate to be 61.3%. This is the first report that proved the utility of hemodialysis for bromate intoxication in a clinical setting.

Acute Kidney Injury↗
PubMed2002

[Aneurysm of the diverticulum of the ductus arteriosus in the adult with left pneumonectomy; report of a case].

A 51-year-old man with dyspnea was admitted to our hospital. Chest computed tomography (CT) scan and aortogram indicated a diagnosis of aneurysm of diverticulum of the ductus arteriosus. Aneurysm of the diverticulum of the ductus arteriosus in the adult is rare. To our knowledge, 34 cases have been reported in the Japanese literature. Operation was performed through standard left postero-lateral thoracotomy. Initially left pneumonectomy was performed because of severe left lung collapse. And subsequently graft replacement of distal aortic arch was performed with hypothermic retrograde cerebral perfusion. The aneurysmal wall directly penetrated into the trachea with occluded orifice by thrombus. The penetrating wall of the trachea was closed by mattress suture with pericardial pledget. And an omental graft was placed. Five weeks after surgery, high fever and pus discharge from the wound of the thoracotomy developed. The debridement of the thoracic cavity was performed, and the cavity was intermittently irrigated with an electrolyzed strong acid solution. The infection successfully subsided gradually and the patient has been well for 9 months after the initial surgery.

Aneurysm↗
PubMed2002

[DeBakey IIIb type dissecting aneurysm with adrenal myelolipoma; report of a case].

We report a case of DeBakey IIIb type dissecting aneurysm with adrenal myelo-lipoma in a 50-year-old woman. The patient was referred to our hospital for severe back pain with severe hypertension. The chest computed tomography (CT) scans and aortography showed the DeBakey IIIb type dissecting aneurysm. And the round-shaped masses on her both side adrenal glands were detected by abdominal CT scans. First, the thoracic aneurysm was replaced with a 26 mm woven dacron graft under cardiopulmonary bypass. Six months later a right adrenal tumor was removed under a postero lateral approach. Her postoperative course was uneventful. And her blood pressure control was good with no antihypertensive drug. Pathological findings for the resected tumor was diagnosed as myelolipoma. To our knowledge, a dissecting aneurysm with adrenal myelolipoma has not been previously reported.

Adrenal Gland Neoplasms↗
PubMed2001

XBP1 mRNA is induced by ATF6 and spliced by IRE1 in response to ER stress to produce a highly active transcription factor.

In yeast, the transmembrane protein kinase/endoribonuclease Ire1p activated by endoplasmic reticulum stress cleaves HAC1 mRNA, leading to production of the transcription factor Hac1p that activates the unfolded protein response (UPR). In mammals, no Hac1p counterpart has yet been discovered despite the presence of Ire1p homologs in the endoplasmic reticulum. Instead, the transcription factor ATF6 specific to the mammalian UPR is regulated by intramembrane proteolysis. Here, we identified the transcription factor XBP1, a target of ATF6, as a mammalian substrate of such an unconventional mRNA splicing system and showed that only the spliced form of XBP1 can activate the UPR efficiently. Our results reveal features of the UPR conserved during evolution and clarify the relationship between IRE1- and ATF6-dependent pathways.

Activating Transcription Factor 6↗
PubMed2001

Complementary signaling pathways regulate the unfolded protein response and are required for C. elegans development.

The unfolded protein response (UPR) is a transcriptional and translational intracellular signaling pathway activated by the accumulation of unfolded proteins in the lumen of the endoplasmic reticulum (ER). We have used C. elegans as a genetic model system to dissect UPR signaling in a multicellular organism. C. elegans requires ire-1-mediated splicing of xbp-1 mRNA for UPR gene transcription and survival upon ER stress. In addition, ire-1/xbp-1 acts with pek-1, a protein kinase that mediates translation attenuation, in complementary pathways that are essential for worm development and survival. We propose that UPR transcriptional activation by ire-1 as well as translational attenuation by pek-1 maintain ER homeostasis. The results demonstrate that the UPR and ER homeostasis are essential for metazoan development.

Animals↗
PubMed2001

The membrane-anchored MMP inhibitor RECK is a key regulator of extracellular matrix integrity and angiogenesis.

Matrix metalloproteinases (MMPs) are essential for proper extracellular matrix remodeling. We previously found that a membrane-anchored glycoprotein, RECK, negatively regulates MMP-9 and inhibits tumor invasion and metastasis. Here we show that RECK regulates two other MMPs, MMP-2 and MT1-MMP, known to be involved in cancer progression, that mice lacking a functional RECK gene die around E10.5 with defects in collagen fibrils, the basal lamina, and vascular development, and that this phenotype is partially suppressed by MMP-2 null mutation. Also, vascular sprouting is dramatically suppressed in tumors derived from RECK-expressing fibrosarcoma cells grown in nude mice. These results support a role for RECK in the regulation of MMP-2 in vivo and implicate RECK downregulation in tumor angiogenesis.

Animals↗
PubMed2001

Interleukin-1beta stimulates galectin-9 expression in human astrocytes.

Galectin-9 is an eosinophil chemoattractant produced by activated T lymphocytes. We have addressed expression of galectin-9 in normal human astrocytes in culture. Expression of galectin-9 mRNA and protein were examined by reverse transcription-polymerase chain reaction (RT-PCR), Western blotting, and immunofluorescent staining. Interleukin-1beta (IL-1beta) was found to enhance the galectin-9 expression in time- and concentration-dependent manners. Galectin-9 protein was detected in the membrane fraction, 105 000 x g precipitate, and immunofluorescent staining revealed diffuse cellular and perinuclear distributions. Dexamethasone pretreatment almost completely suppressed the production. We conclude that astrocytes produce galectin-9 in response to the stimulation with IL-1beta, and this may contribute to inflammatory reactions in the CNS.

Anti-Inflammatory Agents↗
PubMed2001

Isoform-specific effects of apolipoprotein E on atherogenesis: gene transduction studies in mice.

BACKGROUND: We recently used a bone marrow-based gene therapy approach to show that small amounts of retrovirus-derived human apolipoprotein E3 (apoE3) produced by macrophages are protective against early atherosclerosis in apoE-deficient mice. METHODS AND RESULTS: In the present study, we evaluated whether the effect produced by macrophage-derived apoE3 is related to its ability to bind cellular membranes. To this end, we used apoE2 and apoEcys142, dysfunctional human variants with reduced binding to the LDL receptor or to heparan sulfate proteoglycans, respectively. ApoE-deficient mice, 5 weeks of age, received transplants of apoE(-/-) bone marrow cells transduced with either parental retrovirus or apoE3, apoE2, or apoEcys142 retroviral vectors. Human apoE was detected by ELISA in the serum of apoE3, apoE2, and apoEcys142 mice as early as 4 weeks after bone marrow transplantation, and at 8 weeks, plasma apoE levels were 55.5+/-20.3, 50.5+/-8.7, and 15.3+/-7.3 microgram/dL, respectively. In all groups, cholesterol levels increased with age but were not affected by apoE expression. As previously demonstrated, the lesion area in male apoE3 mice (3808+/-2224 micrometer(2)/section) was 40% smaller than that in control mice (6503+/-3475 micrometer(2)/section). In apoE2 mice, however, the lesion area was similar to that of controls (5991+/-2771 micrometer(2)/section), and apoEcys142 mice showed an unexpected and significant increase in lesion size (10 320+/-6128 micrometer(2)/section). Thus, transplantation with marrow transfected with receptor binding-defective apoE variants did not replicate the antiatherogenic effect of apoE3. CONCLUSIONS: These data provide in vivo evidence suggesting that macrophage-derived apoE delays development of atherosclerosis through a receptor-dependent pathway.

Animals↗
PubMed2001

Inactivation of the retinoblastoma tumor suppressor induces apoptosis protease-activating factor-1 dependent and independent apoptotic pathways during embryogenesis.

Inactivation of the retinoblastoma (Rb) tumor suppressor in the mouse induces mid-gestational death accompanied by massive apoptosis in certain tissues. Herein, we analyzed the role of the apoptosis protease-activating factor Apaf-1, an essential component of the apoptosome, in mediating apoptosis in Rb-deficient mice. Analysis of compound mutant embryos lacking Rb and Apaf-1 revealed that Apaf-1 was absolutely required for apoptosis in the central nervous system and lens. In contrast, apoptosis in the peripheral nervous system and skeletal muscles only partly depended on Apaf-1 function. The dependency on Apaf-1 coincided with the requirement documented previously for E2F1 and p53 in the respective tissues. Loss of Apaf-1 specifically suppressed apoptosis but not the proliferation and differentiation defects in Rb-mutant embryos. We also show that the Apaf1+ but not the Rb+ allele is retained in pituitary tumors arising in Rb+/-:Apaf1+/- double heterozygous mice. Our results indicate that Apaf-1 plays a critical role in apoptosis in a subset of tissues and that both E2F1:p53:Apaf-1-dependent and -independent apoptotic pathways operate downstream of Rb.

Animals↗
PubMed2001

New basic mesoporous silica catalyst obtained by ammonia grafting.

NH3-treated mesoporous silica (FSM-16) contains SiNH2 sites which exhibit basic catalytic activity for Knoevenagel condensation; SiNH2 and SiOH pair sites formed at lower NH3-treatment temperatures exhibit higher turnover frequencies (TFs) in comparison with SiNH2 single sites.

Journal Article↗