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Biomedical subjects

H Taguchi

Publications and source records attributed to H Taguchi.

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

Production and characterisation of monoclonal antibodies to heat-shock protein 60 of Helicobacter pylori.

Two monoclonal antibodies (MAbs), designated as H9 (IgG2a) and H20 (IgM), directed against heat-shock protein 60 (HSP60) of Helicobacter pylori strain TK1029 were established. Affinity-purified antigens cross-reacted in immunoblots with MAb H9 and MAb H20 respectively. These antigens also reacted with the 3C8 MAb previously established in this laboratory, which recognised Yersinia enterocolitica HSP60. By amino-acid sequence analysis, the N-terminal amino-acid sequence of the protein recognised by both H9 and H20 MAbs was confirmed as the amino-acid sequence of H. pylori HSP60 reported previously. Both MAbs reacted with nine strains of H. pylori in enzyme-linked immunosorbent assay (ELISA) and immunoblot analysis. In addition, MAb H9 reacted with extracts of other bacteria including H. mustelae, Pseudomonas aeruginosa, Vibrio cholerae, Serratia marcescens, Proteus mirabilis, Escherichia coli and Shigella sonnei. In contrast, MAb H20 reacted only with strains H. pylori. These results suggest that both the species-specific epitope recognised by MAb H20 and the common epitope recognised by MAb H9 exist on HSP60 of the bacterial cell. Both MAbs also reacted with the 60-kDa protein in the lysate of human gastric carcinoma (MKN45) cells. It was shown by immunohistochemical staining that gastric epithelial cells of four out of six biopsy specimens examined stained positively with MAb H20. These results suggest that there is a common epitope in H. pylori HSP60 and human gastric epithelial cells.

Amino Acid Sequence↗
PubMed1997

Heat-shock protein 60 homologue of Helicobacter pylori is associated with adhesion of H. pylori to human gastric epithelial cells.

A previous study reported a relationship between the expression of heat-shock protein 60 (HSP60) by Helicobacter pylori and its adhesion to human gastric carcinoma (MKN45) cells. To examine whether the HSP60 homologue of H. pylori is associated with the adhesion of H. pylori to human gastric epithelial cells, an inhibition assay of adhesion of H. pylori to MKN45 cells was performed by flow cytometric analysis with monoclonal antibody (MAb) designated as H20 recognising HSP60 of H. pylori. The rate of adhesion of H. pylori pretreated with MAbH20 to MKN45 cells was lower than that of untreated H. pylori. Primary human gastric epithelial cells from a patient with gastric cancer were also prepared for comparison in the inhibition assay with MAbH20. H. pylori adhered to the primary human gastric epithelial cells, and this adhesion was significantly inhibited by MAbH20. These results suggest that the H. pylori HSP60 homologue recognised by MAbH20 might be associated with the adhesion of H. pylori to primary human gastric epithelial cells as well as to cultured gastric cancer cells.

Adhesins, Bacterial↗
PubMed1997

Studies on the relationship between adhesive activity and haemagglutination by Helicobacter pylori.

The adhesion of Helicobacter pylori to gastric carcinoma cells (MKN45, KatoIII and MKN28) and Intestine-407 cells was tested by flow cytometric analysis. The mean adhesion rates of H. pylori strains to MKN45, KatoIII and Intestine-407 cells were 90.5, 42.7 and 15.1%, respectively. There was no statistical correlation between the adhesion rates to MKN45 cells and haemagglutination (HA) activity of H. pylori strains, although H. pylori strains with high HA activity with human type O erythrocytes tended to adhere effectively to MKN45 cells. No correlation between adhesion and production of vacuolating toxin was observed.

Animals↗
PubMed1997

PCR-RFLP analysis as an aid to genetic counseling of families of Japanese patients with group A xeroderma pigmentosum.

Because Japanese patients with complementation group A xeroderma pigmentosum (XP-A) show early skin cancer and severe neurologic dysfunction, their family members are greatly concerned about the risk of inherited disease. In contrast to western XP-A patients, almost all Japanese XP-A patients have two of the three mutations (nonsense mutation in exon 3, splicing mutation in intron 3, and non-sense mutation in exon 6), which are easily detected by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) analysis. This work was aimed to see whether PCR-RFLP analysis is useful for genetic counseling of XP patients' siblings who are potential carriers of an XP-A gene mutation. In two of the three case studies presented, the probands were homozygous for the splicing mutation in intron 3 of the gene. In their siblings receiving genetic counseling, no mutation was found in the mutation site in one case, and one splicing mutation was found in the second case. In the third case, the proband was a compound heterozygote for the splicing mutation and for an unidentified mutation; in her sibling, no mutation was found in either of these mutation sites. No mutation was found in the siblings' spouses. On the basis of these findings, we reassured the prospective parents that there was little probability of having XP children, but in the second and third cases, we told them that their apparently unaffected children might be carriers. Each couple subsequently had one unaffected child. Thus, PCR-RFLP analysis is useful for genetic counseling of family members of XP-A patients.

Adult↗
PubMed1997

Growth inhibition of Helicobacter pylori by monoclonal antibody to heat-shock protein 60.

The H20mAb recognizing the 60-kilodalton protein, which existed in the outer membrane and was induced by heat shock at 42 C, was established. The molecule recognized with the mAb was a heat-shock protein 60 (HSP60) of Helicobacter pylori. To understand the role of HSP60 on the cell surface of H. pylori, whether or not H20mAb affects the growth of H. pylori was investigated. When bacteria were cultured with H20mAb, growth was markedly inhibited after 24 hr, although an initial 5 hr-incubation with the mAb induced no significant inhibition of H. pylori growth. The 24- and 48 hr growth of the bacteria after washing to remove the mAb at 5 hr was also inhibited though the inhibitory effect was not strong. In electron microscopical analysis, the spots with high electron density in the cytoplasm of the bacteria treated with H20mAb were increased, depending on the length of incubation time from 5 to 24 hr. After 24 hr treatment with H20mAb, bacterial destruction was also observed, indicating bactericidal activity by H20mAb. These results suggest that the HSP60 on the cell surface of H. pylori might have an essential role in the growth of the bacteria.

Amino Acid Sequence↗
PubMed1997

[Trial for isolation of Helicobacter pylori form fecal specimen by immunomagnetic beads separation].

In order to clarify the possibility of feco-oral transmission of Helicobacter pylori, we have employed an immunomagnetic beads (IMB) separation technique and tried to isolate H. pylori from fecal samples. Microaerophilic cultivation and PCR of H. pylori were positive when H. pylori (10(3) cfu) was suspended in Hanks' balanced salt solution (HBSS) for the IMB separation technique. In contrast, when a lower number of H. pylori (10(2) cfu) was suspended in HBSS, 2nd PCR was positive but cultivation was negative. After IMB separation technique from fecal sample containing H. pylori (2 x 10(4) cfu), 20 cfu of H. pylori was recovered by culture. In this case, 1st PCR was negative but 2nd PCR was positive. From a fecal sample of a patient infected with H. pylori, H. pylori was detected only by combination of IMB separation and PCR, although H. pylori was not recovered by culture. These results indicate that IMB separation technique followed by cultivation or PCR would be useful for estimation of the presence of H. pylori fecal samples.

Enzyme-Linked Immunosorbent Assay↗
PubMed1997

A specific oligonucleotide primer for the rapid detection of Lactobacillus lindneri by polymerase chain reaction.

A polymerase chain reaction (PCR) method was developed for the rapid detection of the beer-spoilage heterofermentative lactic acid bacterium Lactobacillus lindneri. Three strains, the Chinese brewery isolate DA1, the Japanese commercial beer isolate BG2, and the Japanese brewery isolate SE3, which were serologically classified as belonging to L. lindneri, were used in this study. After sequencing the 16S rDNA of the isolates DA1 and BG2 and the typical beer-spoilage heterofermentative Lactobacillus brevis L63, these sequences were compared with published data. A L. lindneri specific PCR primer, DA-40, was then constructed based on the V1 variable region of 16S rDNA. The specificity of PCR using the L. lindneri specific primer DA-40 and the universal primer 907r was examined using five L. lidneri strains: the three isolates described above and two strains from culture collection, DSM 20690 and DSM 20692. A variety of beer-spoilage lactic acid bacteria, including 71 Lactobacillus strains and 13 Pediococcus strains, were also included in this examination. No PCR product was obtained from any DNA with the exception of the five L. lindneri strains, indicating that the L. lindneri specific primer DA-40 was highly specific. The detection limit for L. lindneri in beer was 63 CFU/100 mL of beer.

Antibodies, Bacterial↗
PubMed1997

Mildly oxidized low-density lipoprotein impairs responses of carotid but not basilar artery in rabbits.

BACKGROUND AND PURPOSE: Intracranial blood vessels appear to be relatively resistant to development of atherosclerosis. The goal of this study was to compare effects of mildly oxidized LDL (ox-LDL) on endothelium-dependent responses of intracranial and extracranial arteries in vitro. METHODS: LDL was purified from plasma of healthy subjects and mildly oxidized by means of a xanthine/xanthine oxidase reaction. Contraction of the rabbit basilar and carotid arteries in response to histamine and phenylephrine and relaxation in precontracted vessels to acetylcholine and sodium nitroprusside were evaluated after 30 minutes of exposure to LDL or ox-LDL (100 micrograms/mL). RESULTS: Exposure to LDL had little or no effect on vascular responses. After exposure to ox-LDL, contraction to histamine and phenylephrine and relaxation to acetylcholine were impaired significantly in carotid (P < .05) but not in basilar artery. Relaxation to sodium nitroprusside was not significantly impaired by ox-LDL in the basilar artery. In the carotid artery, relaxation to sodium nitroprusside was significantly impaired by ox-LDL when the vessels were precontracted with phenylephrine but not histamine. Impairment of vascular responses by ox-LDL was prevented by addition of superoxide dismutase, catalase, or dimethylthiourea to the LDL solution before addition of xanthine/xanthine oxidase. CONCLUSIONS: Mildly ox-LDL impairs contraction and endothelium-dependent relaxation in the carotid but not in basilar artery. Thus, intracranial arteries may be relatively resistant to mildly ox-LDL.

Animals↗
PubMed1997

The effects of niacin on DNA repair after N-methyl-N'-nitro-N-nitrosoguanidine treatment in normal human lymphocytes.

We have investigated the effects of niacin on NAD levels and on DNA repair in human lymphocytes. When lymphocytes were incubated in culture medium with various concentrations of niacin, incubation of lymphocytes with nicotinic acid at 5 microM or nicotinamide at 10 mM caused a 2-3 fold increase in NAD content. Under these conditions lymphocytes were treated with N-methyl-N'-nitro-N-nitrosoguanidine (MNNG). Interestingly, the rejoining of DNA strand breaks was promoted by nicotinic acid but nicotinamide inhibited the rejoining.

Carcinogens↗
PubMed1997

Polymerase chain reaction amplification of Asp f I and alkaline protease genes from fungus balls: clinical application in pulmonary aspergillosis.

Asp fI(18 kDa) and alkaline protease (33 kDa) are the 2 major antigens which are derived from Aspergillus (A.) fumigatus and have been implicated as possible virulence factors in the pathogenesis of Aspergillus-induced diseases. We attempted to detect fragments of genes encoding both proteins from fungus balls obtained at surgery or autopsy by polymerase chain reaction (PCR) amplification and then used PCR to test clinical samples. Frozen-stored fungus ball samples from a patient with acute myeloid leukemia complicated by Aspergillus pneumonia and from a patient with pulmonary aspergilloma were studied. We successfully amplified a 315 bp PCR product, the target sequence for Asp f I, and a 747 bp PCR product as a target sequence for alkaline protease (ALP) in both cases. In addition, 13 clinical samples including sputum specimens from patients with pulmonary aspergillosis were also examined. PCR analysis for the Asp f I (ALP) gene in clinical samples showed positive results in 5/10 (6/10) patients with pulmonary aspergilloma and in 3/3 (1/ 3) patients with invasive pulmonary aspergillosis. Culture data on A. fumigatus revealed positive results in 3/9 patients with pulmonary aspergilloma and in 2/3 patients with invasive pulmonary aspergillosis. This method can be used to recognize the involvement of A. fumigatus in various clinical settings where conventional culture results are not readily available.

Adult↗
PubMed1997

[Four cases of carotid body tumor--especially the usefulness of CT and MRI in preoperative diagnosis].

Four cases of carotid body tumor are reported. Surgical removal of the tumor was performed in all cases. The internal carotid artery (ICA) was preserved in only two cases. In the other two cases ICA was unavoidably replaced by an EPTFE (expanded polytetrafluoroethylene) graft. In addition to the size and mobility in the anterior and posterior direction of the tumor, we concluded that CT and MRI were useful in decision of the surgical method. In case the ICA cannot be distinguished from the tumor at the bifurcation of the carotid artery on enhanced CT, it should be considered to be difficult to remove the tumor. MRI is suitable for discerning the inner surface of the carotid artery, but it is significant that MRI cannot necessarily reveal tumor invasion of the carotid artery wall.

Adult↗
PubMed1997

[Propofol anesthesia for a schizophrenic patient].

A 41-year-old man weighing 68 kg was scheduled for bilateral tonsillectomy because of palmoplantar pustulosis. The patient had been diagnosed as schizophrenic 10 years earlier. Psychotropic agents, mosapramine (75 mg.day-1), bromperidol (6 mg.day-1), cloxazolam (3 mg.day-1), biperiden (1 mg.day-1) and nitrazepam (5 mg as needed), were administered until the day before surgery. On the day of surgery, atropine (0.g mg) and midazolam (4 mg) were administered intramuscularly as premedication. Anesthesia was induced by intravenous propofol (120 mg) and fentanyl (100 microgram) followed by nasotracheal intubation using vecuronium (7 mg). Anesthesia was maintained with inhalation of oxygen and nitrous oxide (2 l.min-1 each) and the intravenous infusion of propofol (5-10 mg.kg-1 x h-1) supplemented by fentanyl (100 microgram). The patient recovered from anesthesia uneventfully. Immediately after surgery, intravenous haloperidol (5 mg) and intramuscular biperiden (1 mg) were given. The daily oral administration of psychotropics was resumed on the first postoperative day. There were no complications such as hypotension, arrhythmia, or worsening of the mental condition, throughout the course.

Adult↗
PubMed1997

Fluorophotometric quantitation of oxidative stress in the retina in vivo.

PURPOSE: To establish a new fluorophotometric method to quantitate oxidative stress in the retina in vivo with a hydrogen peroxide (H2O2)-sensitive fluorescent dye. METHODS: For in vitro fluorophotometric study, nonfluorescent 2',7'-dichlorofluorescein (DCFH) was incubated with H2O2 (10 pM to 100 nM), and the production of fluorescent 2',7'-dichlorofluorescein (DCF) was measured with fluorophotometric analysis. The inhibitory effect of catalase was also examined. For in vivo fluorophotometric study, rabbit eyes received vitrectomy and were perfused with 5 microM 2',7'-dichlorofluorescein diacetate (DCF-DA) or 2',7'-dichlorofluorescein diacetate (DCFH-DA). For oxidative stress, 300 microM H2O2 was infused after perfusion of DCFH-DA. Fluorophotometric measurements of the chorioretinal peak were performed. The eyes were enucleated for fluorescent microscopic examination to determine the localization of DCF fluorescence. RESULTS: H2O2 converted DCFH to DCF in a dose-dependent manner, which was inhibited by catalase dose dependently. In vivo fluorophotometric study showed DCF-DA and DCFH-DA caused production of 2006 +/- 274 picomole/ml (mean +/- SD, n = 5) and 8.35 +/- 1.11 picomole/ml (n = 5), respectively, in the chorioretinal peak. DCFH-DA with stimulation by H2O2 induced 30.7 +/- 13.1 (n = 4) picomole/ml DCF. Fluorescent microscopy showed DCF production in the retina was significant in the eye treated with DCF-DA and minimal in the eye treated with DCFH-DA. Moderate DCF production in the nerve fiber layer was observed in the eye treated with DCFH-DA and H2O2. CONCLUSIONS: This new fluorophotometric method with DCFH-DA may be useful in quantitatively evaluating oxidative stress in the retina in vivo.

Animals↗
PubMed1996

Biphenotypic leukemia with a new translocation, t(2;6)(q31;q23).

A t(2;6)(q31;q23) was found in a patient with acute biphenotypic leukemia. This cytogenetic change has not been reported previously in acute lymphocytic leukemia (ALL) or biphenotypic leukemia, although deletion of 6q has been frequently found in ALL.

Cell Lineage↗