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S Kamiya

Publications and source records attributed to S Kamiya.

At least 37 records · Page 2Linked to original sources
PubMed2000

Bioavailable acyl-CoA: cholesterol acyltransferase inhibitor with anti-peroxidative activity: synthesis and biological activity of novel indolinyl amide and urea derivatives.

We synthesized a series of indoline derivatives with an amide or urea moiety and examined their inhibitory effects on acyl-CoA:cholesterol acyltransferase (ACAT) activity, lipid-peroxidation and serum cholesterol levels in experimental animals. Among the derivatives synthesized, a series of N-(1-alkyl-4,6-dimethylindolin-7-yl)-2,2-dimethylpropanamides++ + potently inhibited rabbit intestinal ACAT activity and lipid-peroxidation of rat brain homogenate. The effect on ACAT activity was related to the length of the alkyl chain at the 1-position of indoline. N-(4,6-Dimethyl-1-octylindolindolin-7-yl)-2,2-dimethylpropanami de hydrochloride (55) showed inhibitory effects on intestinal and hepatic ACAT activity slightly weaker than those of YM-750, and an inhibitory effect on low density lipoprotein (LDL)-peroxidation similar to that of probucol. Compound 55 also reduced serum cholesterol at 10 mg/kg/d in hyperlipidemic rats and 20 mg/kg/d in normolipidemic hamsters. The plasma concentration of 55 reached 716 ng/ml in dogs (10 mg/kg, p.o.), which is an effective concentration against hepatic ACAT activity and LDL-peroxidation. In conclusion, compound 55 is a novel bioavailable ACAT inhibitor with anti-peroxidative activity and is thus a promising anti-atherosclerotic and anti-hyperlipidemic drug. Indoline proved to be a useful pharmacophore for molecular design of new anti-peroxidative drugs.

Amines↗
PubMed2000

Localized amyloidosis in canine mammary tumors.

Histopathologic and immunohistochemical examinations were performed on localized amyloidosis associated with mammary tumors in two dogs. These tumors were identified as adenoma and adenocarcinoma. An acellular, amorphous pale eosinophilic material (amyloid) was observed in the lumina of acini lined by neoplastic cells and in the stroma of the tumors. Concentrically laminated pale eosinophilic bodies (corpora amylacea) were also found in the lumina of the acini. Amyloid and corpora amylacea stained positively with Congo red with and without 5% potassium permanganate pretreatment and revealed a green birefringence under polarized light. Corpora amylacea showed an occasional Maltese-cross pattern. Immunohistochemically, amyloid and corpora amylacea usually stained positively with anti-bovine alpha-casein antibody but negatively with anti-human amyloid AA, anti-bovine kappa-light and lambda-light chains, anti-human lactoferrin, anti-human transferrin, anti-human secretory component, and anti-human polyglucosan antibodies. These findings suggested that the amyloid deposition in these canine mammary tumors was related to lactating casein.

Adenocarcinoma, Papillary↗
PubMed2000

[Personality correlates of autobiographical memory].

The purpose of this study was to examine the relationship between personality traits and autobiographical memory. Ninety-one (91) undergraduates completed an autobiographical memory questionnaire, describing experiences of unpleasant emotional episodes, and then rating their qualities: Vividness, emotionality, influence, and so on. They also completed a number of personality inventories, including the Yatabe-Guilford Personality Inventory and Self-Acceptance Inventory. Results indicated that emotionally stable and high-activity subjects perceived past unpleasant episodes as more positive, although there was no qualitative difference. Compared with emotionally unstable and low-activity subjects, they also had a higher self-acceptance score, and acknowledged and accepted own shortcomings. People with adaptive personality appear to have positive views on many aspects of the self. These findings were interpreted from the self-schema perspective of memory.

Adult↗
PubMed2000

Cloning, sequencing, and transcriptional analysis of the dnaK heat shock operon of Listeria monocytogenes.

The complete dnaK operon of Listeria monocytogenes was isolated by chromosome walking using the previously cloned dnaK gene as a probe. Molecular analysis of the locus identified 6 genes in the order hrcA, grpE, dnaK, dnaJ, orf35, and orf29. Primer extension analysis revealed 3 transcription start sites-S1, S2, and S3-upstream of the hrcA, grpE, and dnaJ, respectively. The transcription from S1 was heat inducible. Analysis of the sequences revealed the consensus promoter sequences of gram-positive bacteria, P1 and P2 upstream of the hrcA and dnaJ, respectively. The hrcA gene and a regulatory sequence, designated CIRCE (controlling inverted repeat of chaperone expression), play a role in the regulation of expression of the dnaK locus in response to heat shock in several gram-positive bacteria. Their presence upstream of the dnaK locus in L. monocytogenes suggested a similar regulatory mechanism for the transcription initiated at the promoter, P1. Northern blot analysis led to the detection of 4 mRNA species of 4.9 kb, 3.6 kb, 3.6 kb, and 1.2 kb; the first 2 species were heat inducible. The current results indicate that 4 distinct transcripts directed by 3 promoters are involved in the expression of the dnaK operon of L. monocytogenes.

Amino Acid Sequence↗
PubMed2000

The fibronectin-derived anti-adhesive peptide III14-2 suppresses adhesion and apoptosis of leukemic cell lines through down-regulation of protein-tyrosine phosphorylation.

We previously found that fibronectin (FN) has a cryptic functional site (YTIYVIAL, #1848-1855) opposing to cell adhesion to extracellular matrix (ECM). The present study demonstrates that the FN peptide containing this anti-adhesive site, termed peptide III14-2, affects programmed cell death (PCD) (apoptosis) as well as cell adhesion by down-regulating protein-tyrosine phosphorylation. Peptide III14-2 suppressed the integrin alpha5beta1-mediated adhesion of leukemic cell lines (K562 and HL60), and protein tyrosine phosphatase inhibitor, 1 microM phenylarsine oxide (PAO) blocked the anti-adhesive effect of peptide III14-2. These leukemic cells underwent PCD when exposed to PAO at the higher concentration (5 microM), as judged by nuclear and DNA fragmentations, and which was reversed by tyrosine kinase inhibitor, genistein. Peptide III14-2 suppressed the PAO-induced PCD, whereas a control peptide in which the anti-adhesive sequence YTIYVIAL is scrambled, was inactive. Western blotting showed that PAO stimulated the tyrosine phosphorylation of cellular proteins including focal adhesion kinase and that peptide III14-2 inhibited them, suggesting that protein-tyrosine phosphorylation represents a common early signal for the adhesion and PCD. The anti-adhesive site of FN molecule may play a crucial role also in a variety of cellular processes other than adhesion and PCD by down-regulating protein-tyrosine phosphorylation.

Apoptosis↗
PubMed1999

Analysis of brain proteins in Alzheimer's disease using high-resolution two-dimensional gel electrophoresis.

Two-dimensional gel electrophoresis (2-DE), a method which can be used to analyze the expression of many proteins, is a promising and powerful approach which we have begun to use in the characterization of the complex pathologic processes in Alzheimer's disease (AD). In the present study, a reliable 2-DE database of human brain proteins was created by improving the reproducibility of 2-DE images using an immobilized pH gradient (IPG) for the first dimension gel electrophoresis and Melanie II as the program for data analysis. The brain samples were taken from the temporal cortex of brains at autopsy from 15 AD patients and 15 age-matched controls with non-neurological disorders. About 700 spots were located as consistently expressed proteins in the human brain, all of which were expressed also in AD brains. Comparing the density of spots between AD and normal control, we found that five protein spots were significantly increased, 28 spots were significantly decreased and nine spots were detected only in AD. Two spots among those significantly increased and one spot among those significantly decreased were identified as glial fibrillary acidic proteins. The database of brain proteins in AD constructed for the present study, including the statistical data of density changes in AD, should be a useful beginning for a comprehensive human 2-DE database available via the Internet, which will facilitate further investigation of pathogenic protein alterations in AD.

Aged↗
PubMed1999

Colony formation by Helicobacter pylori after long-term incubation under anaerobic conditions.

To evaluate the viability of Helicobacter pylori cultured under anaerobic conditions, H. pylori strain TK1029 was grown on blood agar in a microaerophilic environment at 37 degrees C for 4 days, and subsequently cultured under anaerobic conditions for 1 to 35 days. Colony formation by bacteria on blood agar plates cultured under anaerobic conditions was observed only for up to 4 days of microaerophilic incubation. By Gram staining, the morphological form of the bacteria was shown to be predominantly coccoid. However, bacteria cultured under anaerobic conditions for 15 to 35 days formed colonies on blood agar after pre-incubation of bacteria with PBS, but not without pre-incubation. These results suggest that H. pylori survives long-term culture under anaerobic conditions and that both pre-incubation in non-nutrient solution and high density of bacterial concentration might be important for recovery of H. pylori cultured for a prolonged time under anaerobic conditions.

Anaerobiosis↗
PubMed1999

Mouse colitis induced by Escherichia coli producing Yersinia enterocolitica 60-kilodalton heat-shock protein: light and electron microscope study.

In patients with inflammatory bowel disease (IBD), including ulcerative colitis (UC), heat-shock protein (Hsp) 60 has been detected in serum and the intestinal tract. Our mouse colitis model was established using Escherichia coli transformed with Yersinia enterocolitica Hsp60 gene as an immunizing antigen, and examined light and electron microscopically as compared with lesions of UC. The large intestine of mice injected with Hsp60 antigen showed swollen goblet cells, glandular dilation, erosion, ulceration, and infiltration of inflammatory cells. The change like crypt abscesses was also found, and various phases of inflammation were observed simultaneously in individual mice. In addition, the reticulum fibers were absent ultrastructurally in the subepithelial reticular layer. Hyperplasia of the thymus was found in antigen-treated mice. These lesions were similar to those of UC. These results suggest that UC-like enteritis in mice was induced by using Hsp60, considered as one of the pathogens for UC.

Animals↗
PubMed1999

Heat shock protein 60 (HSP60) immunoreactivity in gastric epithelium associated with Helicobacter pylori infection: a pitfall in immunohistochemically interpreting HSP60-mediated autoimmune responses.

Previous studies have suggested that heat shock proteins (HSP) of Helicobacter pylori (H. pylori) are involved in the induction of autoimmunity mediated gastritis. In the present report, the cross-reactivity between H. pylori-related HSP60 and gastric epithelial cells was investigated by the indirect immunoperoxidase method using two monoclonal antibodies (mAb) against H. pylori-derived HSP60, H9 and H20. H9 is reactive with an epitope common to bacterial HSP60, while H20 is specific to H. pylori HSP60. A total of 70 paraffin-embedded gastric biopsy specimens were analyzed after heat-induced epitope retrieval. Both mAb were cross-reactive with the gastric epithelial cells, with a higher frequency seen for the H9-reactive epitope. The frequency of positive epithelial decoration was not significantly different between H. pylori-positive and H. pylori-negative gastric mucosae. A variety of epithelial and non-epithelial cells were immunostained with mAb H9, while mAb H20 was cross-reactive only with small intestinal epithelia. Reactivity was mainly located in the Golgi area and rarely in the cytoplasm. These results suggest a noteworthy pitfall in immunohistochemical interpretations of HSP60-associated autoimmune reactions in the gastric mucosa.

Antibodies, Bacterial↗
PubMed1999

Effect of an aluminum hydroxide-magnesium hydroxide combination drug on adhesion, IL-8 inducibility, and expression of HSP60 by Helicobacter pylori.

BACKGROUND: Co-magaldrox (Maalox) is used world-wide as an antacid and as a cytoprotective agent for gastritis and peptic ulcer diseases. We examined the effects of co-magaldrox on Helicobacter pylori. METHODS: Adhesion of H. pylori to human gastric epithelial cells (MKN45) was evaluated by flow cytometry. Morphologic changes in H. pylori caused by co-magaldrox were determined by scanning electron microscopy. Induction of interleukin-8 (IL-8) from MKN45 cells was examined with enzyme-linked immunosorbent assay, and the intracellular and extracellular expression of heat-shock protein 60 (HSP60) was analyzed with sodium dodecyl sulphate-polyacrylamide gel electrophoresis and flow cytometry. RESULTS: Adhesion of H. pylori to MKN 45 cells was significantly inhibited by 1.25%-5% comagaldrox. H. pylori aggregated with co-magaldrox according to an electron microscopic examination. IL-8 secretion from MKN45 cells after H. pylori infection was also inhibited by co-magaldrox. Extracellular expression of HSP60 on the surface of H. pylori was decreased after treatment with comagaldrox, whereas the intracellular synthesis of HSP60 was not. HSP60-induced IL-8 secretion was significantly inhibited by co-magaldrox in a dose-dependent manner. CONCLUSIONS: These results show that co-magaldrox suppressed the expression of the following virulence factors: adhesion, IL-8 inducibility, and expression of extracellular HSP60. Therefore, co-magaldrox is a potent anti-H. pylori and cytoprotective drug.

Aluminum Hydroxide↗
PubMed1999

Detection of Clostridium difficile toxin A by reversed passive latex agglutination.

A reversed passive latex agglutination (RPLA) assay for detecting Clostridium difficile toxin A is presented. Purified monoclonal antibody (mAb 37B5) was used for latex sensitization. The culture supernatants of 93 strains of C. difficile were tested by RPLA assay and the results compared with those of a commercially available latex agglutination test, PCR and cytotoxin assay with Vero cells. There was agreement between RPLA, cytotoxicity and PCR assays, but 29 strains were positive in the RPLA assay while 35 were positive in the cytotoxicity test and PCR using primer pair NK3-NK2 directed to the nonrepeating portion of the C. difficile toxin A gene. The 6 cytotoxic but RPLA-negative strains were demonstrated to be toxin A-negative/toxin B-positive strains in the PCR assay by using primer pair NK11-NK9 directed to the repeating portion of the C. difficile toxin A gene. There were no cross-reactions with culture supernatants of the other clostridial strains except for two strains of C. sordelli that produced hemorrhagic toxin (which is immunologically related to C. difficile toxin A).

Agglutination Tests↗
PubMed1999

[Antibacterial effects of cacao mass on enterohemorrhagic Escherichia coli O157:H7].

The antimicrobial activities of aqueous cacao mass extract against enterohemorrhagic Escherichia coli (EHEC) O157:H7 006 strain were studied. Hot water extract of cacao mass (cocoa extract) was shown to inhibit the growth of EHEC O157:H7 006 strain in PBS or CAYE medium. In addition, the production of verotoxins (types 1 and 2) of EHEC O157:H7 006 strain was significantly inhibited by 8.0% cocoa extract. The cocoa extract did not neutralize the cytotoxity of verotoxins, but had inhibitory effect on adhesion of verotoxins to the target Vero cells. These results demonstrate that cacao mass has antimicrobial effects on EHEC O157:H7.

Bacterial Toxins↗
PubMed1999

[Antagonistic interaction between Clostridium butyricum and enterohemorrhagic Escherichia coli O157:H7].

Antagonistic interaction between Clostridium butyricum strain MIYAIRI 588 and enterohemorrhagic Esherichia coli (EHEC) strain O157:H7 006 was examined using streptomycin-treated SPF mice and germ free mice. All SPF mice pretreated with streptomycin were colonized with EHEC O157:H7. On the other hand, only 20% of the SPF mice pretreated with streptomycin and C. butyricum were colonized with EHEC O157:H7. In addition, germ free mice died within 4-7 days after infection with EHEC O157:H7. In contrast, all gnotobiotic mice mono-associated with C. butyricum survived after the challenge with EHEC O157:H7. Both the number of EHEC and the amounts of shiga-like cytotoxin (SLT, type 1 and type 2) in fecal contents of gnotobiotic mice treated with C. butyricum were less than those of mice infected with only EHEC O157:H7. In conclusion, the probiotic bacterium, C. butyricum strain MIYAIRI 588, has a preventive effect against EHEC O157:H7 infection.

Animals↗
PubMed1999

Differential involvement of small G proteins in Alzheimer's disease.

Alzheimer's disease (AD) is a neurodegenerative disease characterized by the progressive deterioration of cognitive function and memory in association with the wide-spread presence of senile plaques, neurofibrillary tangles and neuronal cell death. However, its pathophysiology remains unknown. GTP-binding proteins with molecular weights of approximately 20,000 are designated small G proteins. In the present study we quantitatively analyzed the small G proteins, Ras, Rap, Ral and Rab in brains removed at autopsy from controls and AD patients to examine whether small G proteins are equally or differentially affected in AD. Western blot analysis indicated that the protein level of Ras and RalB in both the cytosolic and membranous fractions and that of Rap2 in the cytosolic fraction was significantly decreased, while that of Rab8 in the membranous fraction was significantly increased in AD brains compared with controls. The protein level of other small G proteins was not different between control and AD brains. These results suggest a differential involvement of small G proteins in AD.

Aged↗