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Biomedical subjects

S Kamiya

Publications and source records attributed to S Kamiya.

At least 109 records · Page 6Linked to original sources
PubMed1995

Determination of growth fraction index in mammary carcinoma using MIB-1 monoclonal antibody: estimation of whole tumor proliferative potential using biopsy specimens.

We labeled the Ki-67 antigen in mammary carcinomas, using a MIB-1 monoclonal antibody, to evaluate the usefulness of MIB-1 Ki-67 Growth Fraction Indices (GFI; number of Ki-67 positive cells/total number of cells) of biopsy specimens in estimating the proliferative potential of the carcinomas. Formalin-fixed paraffin sections prepared from biopsy material, primary tumors, and axillary lymph nodes of ten invasive mammary carcinomas were chosen for immunohistochemical study. Bound antibody was detected using the avidin-biotin-complex peroxidase method. The GFI of the resected mammary carcinomas was similar to the estimated values based on the GFI of the biopsy specimens. The GFIs of the metastatic nodes in seven of the carcinomas were similar to those of the primary carcinomas, whereas two carcinomas yielded significantly different GFIs in the metastatic foci. These results suggest that the GFI of a mammary carcinoma biopsy specimen may reflect the proliferative ability of the whole carcinoma.

Adult↗
PubMed1994

Polyglucosan bodies in the brain of a cow.

Polyglucosan bodies (PGBs) in the brain of a 12-year-old Holstein cow exhibiting no signs of neurological abnormality were examined by light and electron microscopy and immunohistochemistry. PGBs were disseminated throughout the brain, especially in the pallidum, thalamus and cerebellum. Cow PGBs were found in the neuronal perikaryon and in the neuropil. These were round, slightly to severely basophilic, and were strongly positive for the periodic acid-Schiff reaction. The cow PGBs were immunoreactive for monoclonal antibodies raised against human polyglucosan. Electron microscopic analysis revealed that they were composed of branching filaments, glycogen granules and electron-dense material. These findings indicate that cow PGBs closely resemble human or canine PGBs in Lafora's disease and PGBs found in aged animals that have been reported previously.

Animals↗
PubMed1994

Growth inhibition of Clostridium difficile by intestinal flora of infant faeces in continuous flow culture.

Growth of Clostridium difficile was inhibited more strongly in continuous flow (CF) culture with C. difficile-negative faeces of infants than with C. difficile-positive faeces. Culture of faecal flora of infants yielded a greater variety of bacterial species in C. difficile-negative than in C. difficile-positive faeces. In the mixed CF culture of C. difficile with Enterococcus avium, Bacteroides distasonis, Eubacterium lentum, C. ramosum, C. perfringens and either Escherichia coli or Klebsiella pneumoniae isolated from C. difficile-negative faeces, inhibition of growth of C. difficile was demonstrated when the pH of the culture medium was decreased. Amino-acid analysis of CF cultures showed considerable utilisation of aspartic acid, serine, threonine, arginine and asparagine. A marked increase in concentrations of citrulline and ornithine was found in the culture that inhibited growth of C. difficile. The addition of citrulline and ornithine into a Gifu anaerobic medium (GAM) broth produced no inhibition of growth of C. difficile. The addition of the mixture of the depleted amino acids (aspartic acid, serine, threonine, arginine and asparagine) to the culture filtrate or adjustment of the pH of the culture filtrate induced considerable growth of C. difficile. These results suggest that the inhibition of growth of C. difficile may be due to consumption of amino acids by intestinal flora, and not to the presence of inhibitors produced by the intestinal flora.

Amino Acids↗
PubMed1994

Toxin production by Clostridium difficile in a defined medium with limited amino acids.

Basal defined medium (BDM) containing vitamins, minerals and seven amino acids--(/L) tryptophan 0.1 g, methionine 0.2 g, valine 0.3 g, isoleucine 0.3 g, proline 0.3 g, leucine 0.4 g and cysteine 0.5 g--which appeared to be essential for good growth of Clostridium difficile was prepared. Addition of glycine 0.2 g/L and threonine 0.4 g/L to BDM produced better growth of strain VPI 10463, and this defined medium was designated minimum amino acid-defined medium (MADM). Production of toxins A and B by strain VPI 10463 in 6 x MADM containing (/L) tryptophan 0.6 g, methionine 1.2 g, valine 1.8 g, isoleucine 1.8 g, proline 1.8 g, leucine 2.4 g, cysteine 0.5 g, glycine 0.2 g and threonine 0.4 g, was much greater than in MADM. Toxin production by 20 C. difficile strains was examined in two defined media--6 x MADM and complete amino acid-defined medium (CADM) containing 18 amino acids--and one complex medium, modified brain heart infusion medium (m-BHI). Simultaneous production of toxins A and B by all test strains was demonstrated in m-BHI and the two defined media. It was also shown that 6 x MADM was generally better than CADM and as effective as m-BHI for stimulating toxin production by 13 strains. This defined medium would be useful for studies on the physiology, metabolism and pathogenicity of C. difficile.

Amino Acids↗
PubMed1994

Preparation and taste of certain glycosides of flavanones and of dihydrochalcones.

The 7-O-[2-O-(alpha-L-Rhamnopyranosyl)-beta-L-quinovoside] of naringenin and of hesperetin, and their dihydrochalcone (DHC) derivatives were synthesized by the method of Koenigs-Knorr (Ag2CO3 and quinoline). The reaction of TMS ethers of naringenin and of hesperetin with each of the alpha-acetofluoro derivatives of D-glucose, L-rhamnose, 2-O-(alpha-L-rhamnopyranosyl)-L-rhamnose, and 2-O-(alpha-L-rhamnopyranosyl)-D-glucose (neohesperidose), using boron trifluoride etherate as an activator, yielded coupling products which, after deprotection, gave naringenin 4'-O-beta-D-glucoside, naringenin 4'-O-alpha-L-rhamnoside, naringenin 4'-O-[2-O-(alpha-L-rhamnopyranosyl)-alpha-L-rhamnoside], hesperetin 3'-O-[2-O-(alpha-L-rhamnopyranosyl)-alpha-L-rhamnoside], and naringenin 4'-O-beta-neohesperidoside, respectively. Catalytic hydrogenation of these flavanones gave the corresponding DHC derivatives. Hesperetin DHC 4'-O-[2-O-(alpha-L-rhamnopyranosyl-beta-L-quinovoside] was 300 times sweeter than sucrose, while the other compounds were bitter or tasteless.

Carbohydrate Sequence↗
PubMed1994

BE-23372M, a novel protein tyrosine kinase inhibitor. I. Producing organism, fermentation, isolation and biological activities.

BE-23372M, a novel protein tyrosine kinase inhibitor, was isolated from the culture broth of a fungus. The producing strain, F23372, was identified as Rhizoctonia solani, based on the cultural and morphological characteristics. The active principle was extracted from the mycelium with acetone and purified by solvent extraction, silica gel column chromatography and Sephadex LH-20 column chromatography. BE-23372M showed strong inhibitory activity against EGF receptor kinase with IC50 values of 0.02 and 0.03 microM on two different substrates, whereas IC50 values against protein kinase C and cAMP-dependent protein kinase were 4.5 and > 20 microM, respectively. The compound inhibited the growth of A431 human epidermoid carcinoma and MKN-7 human stomach cancer cell lines with IC50 values of 8 and 24 microM, respectively.

Amino Acid Sequence↗
PubMed1994

Characteristics of vacuolating toxin produced by Helicobacter pylori.

OBJECTIVE: We sought a good indicator cell line to use in detecting the vacuolating toxin produced by Helicobacter pylori and in examining the characteristics of the toxin. DESIGN AND METHODS: Using five cell lines [baby hamster kidney (BHK-21), human amnion (FL), human uterine cancer (HeLa), rabbit kidney (RK-13) and African green monkey kidney (Vero)], cytotoxicity assays were performed with 33 H. pylori strains. To analyse the proteins produced by toxigenic and non-toxigenic strains, immunoblotting was done with the sera of patients with gastroduodenal diseases. RESULTS: When RK-13, FL, Vero, BHK-21 and HeLa cells were used for the assay, 73, 61, 27, 27 and 21% of strains, respectively, were toxigenic. The vacuolating toxin is sensitive to heat at 70 degrees C. By immunoblot analysis, under non-denaturing conditions, immune sera recognized proteins with molecular weights of 600,000 and 500,000 in the toxigenic but not in the non-toxigenic strains. CONCLUSION: H. pylori produces vacuolating toxin, which is a heat-sensitive protein at 70 degrees C and is easily detectable by cytotoxicity assay using the RK-13 cell line. Toxigenic H. pylori strains produce various proteins, including this toxin, which are recognized by sera from patients with gastroduodenal diseases.

Animals↗
PubMed1994

[Tissue concentration of tegafur suppository in patients with head and neck cancer--concentration of 5-FU in cancer tissue].

Fifty patients with head and neck cancer were treated with tegafur suppository for 7 days preoperatively. The tissues were obtained during surgical operation and the concentrations of 5-FU in cancer tissue, normal tissue and blood were measured. It was revealed that a high concentration of 5-FU was seen in cancer tissue and then metastatic lymph nodes. The 5-FU concentration in cancer tissue was parallel with T stage of the patients. Subsites which showed a high concentration of 5-FU were nasal-paranasal cavity, tongue and mesopharynx. The tegafur suppository was useful because of the high concentration in cancer tissue and metastatic lymph nodes without any obvious side effects in the head and neck region.

Adult↗
PubMed1994

[Evaluation of polymerase chain reaction for diagnosis of Helicobacter pylori infection].

To evaluate diagnostic tests of Helicobacter pylori (H. pylori), we compared polymerase chain reaction (PCR) for the specific detection of H. pylori, culture and positivity of serum antibody against the bacteria in 59 patients with gastroduodenal disease. PCR assay was designed to amplify 203bp of DNA fragments. PCR detected 10pg of H. pylori DNA, or 40 CFU of the bacteria. PCR was positive in 82.1% of histological gastritis with neutrophil infiltration. Culture and serum antibody to H. pylori were positive in 65.0%, and 94.1% of those patients. Detection rate by PCR was significantly higher than that by the culture methods in patients with chronic gastritis. These results demonstrate that PCR is a sensitive diagnostic test for H. pylori infection.

Adult↗
PubMed1993

Evaluation of rapid urease test for detection of Helicobacter pylori in gastric biopsy specimens.

Using 80 gastric biopsy specimens from patients with various gastroduodenal diseases, the isolation rate of H. pylori and urease activity of the biopsy specimens were examined. The sensitivity and specificity of the rapid urease test was 84.6% and 75.9%, respectively, for the cultivation of H. pylori. The mean number of H. pylori detected in urease-positive and negative biopsy specimens was 10(6.1 +/- 0.9) and 10(4.5 +/- 1.2) cfu/g specimens, respectively.

Adult↗
PubMed1993

Purification and characterisation of intracellular toxin A of Clostridium difficile.

After sonic disintegration of Clostridium difficile cells, intracellular toxin A was purified to homogeneity by thyroglobulin affinity chromatography (TGAC) followed by anion-exchange (Mono Q) by fast protein liquid chromatography (FPLC). High haemagglutinating (HA) activity was detected in TGAC-unbound fractions (2(9)/50 microliters), but not in TGAC thermal eluates (2(0)/50 microliters). The low HA titre of the thermal eluates was markedly increased to 2(5)/50 microliters after dialysis against 0.02 M Tris-HCl (pH 7.5). A disparity in the position of the peaks containing cytotoxic and HA activity was observed in the first Mono Q-FPLC step. Intracellular toxin A without HA activity was obtained by a second Mono Q-FPLC step. The M(r) of the intracellular toxin A was estimated by polyacrylamide gel electrophoresis (PAGE) to be 580 kDa under non-denaturing conditions. The minimum doses of the toxin causing cytotoxicity, mouse lethality and enterotoxicity were 0.83 ng, 8.7 ng and 5 micrograms, respectively.

Animals↗
PubMed1993

Rapid detection of Mycoplasma pneumoniae in clinical samples by the polymerase chain reaction.

A DNA amplification method was used to detect Mycoplasma pneumoniae in clinical samples. M. pneumoniae 16S ribosomal RNA gene sequences were selected as the amplification target region. The polymerase chain reaction (PCR) with purified DNA fragments as templates yielded an expected 88-bp fragment from M. pneumoniae but not from other Mycoplasma spp. nor from any of the other bacteria assayed. With this method, the 88-bp product specific for M. pneumoniae could be obtained from a minimum of 0.05 pg of M. pneumoniae DNA. Subsequently this PCR technique was used for the detection of M. pneumoniae in throat-swab samples. Twenty-two of 30 culture-positive clinical samples gave positive results in the PCR test. Thirty-two culture-negative clinical samples and 33 samples from healthy volunteers, of which only one was culture-positive, gave negative results in the same PCR test. This PCR method is useful for the direct detection of M. pneumoniae in clinical samples.

Base Sequence↗
PubMed1993

Analysis of intestinal flora of a patient with congenital absence of the portal vein.

A 14-year-old female patient, admitted for a closer examination of liver tumour (hepatocellular adenoma), was diagnosed as having a congenital absence of the portal vein. The blood ammonia level (approximately 120 micrograms dl-1) in the superior mesenteric vein was markedly low compared to the normal value of 300-350 micrograms dl-1 in the portal vein. The decreased ammonia concentration and urease activity of the patient's faeces were demonstrated. The dominant intestinal flora in the faeces of the patient, before operation, was Bifidobacterium sp., Bifidobacterium breve, Bifidobacterium lonqum, Lactobacillus plantarum, and after the operation Bacteroides vulgatus, Veillonella parvula, Peptococcus magnus Bifidobacterium longum. In contrast, Bifidobacterium bifidum, Bacteroides ureolyticus, Bacteroides ovatus and Bacteroides distasonis, B. ovatus, Bifidobacterium adolescentis were dominant flora in the faeces of two healthy volunteers, respectively. Among microorganisms isolated from the patient, Morganella morganii, Candida sp., Eubacterium aerofacience and Eubacterium rectale were strongly positive in urease activity in vitro; Streptococcus mitior, Staphylococcus intermedius, Micrococcus kristinae, Selenomonas ruminantum, Bacteroides ureolyticus and Lactobacillus casei ss. pseudoplantarum from the healthy volunteers. These results imply the homeostatic regulation system of faecal ammonia concentration by urease-producing microorganisms in the patient.

Adolescent↗
PubMed1993

Synthesis of alpha-L-mannopyranosyl-containing disaccharides and phenols as substrates for the alpha-L-mannosidase activity of commercial naringinase.

In order to clarify the substrate specificity of the alpha-L-mannosidase activity of naringinase (Sigma), the following disaccharides and phenol glycosides were freshly prepared: methyl 2-O-(alpha-L-mannopyranosyl)-beta-D-glucoside (1), methyl 3-O-(alpha-L-mannopyranosyl)-alpha-D-glucoside (2), methyl 4-O-(alpha-L-mannopyranosyl)-alpha-D-glucoside (3), methyl 5-O-(alpha-L-mannopyranosyl)-beta-D-glucoside (4), methyl 6-O-(alpha-L-mannopyranosyl)-alpha-D-glucoside (5), 6-O-(alpha-L-mannopyranosyl)-D-galactose (6), p-nitrophenyl alpha-L-mannoside (7), and 4-methyl umbelliferone alpha-L-mannoside (8). These compounds, except for 3 and 5 were hydrolyzed with naringinase.

Carbohydrate Sequence↗
PubMed1992

The energy transduction mechanism is different among P-type ion-transporting ATPases. Acetyl phosphate causes uncoupling between hydrolysis and ion transport in H+,K(+)-ATPase.

H+,K(+)-ATPase, Na+,K(+)-ATPase, and Ca(2+)-ATPase belong to the P-type ATPase group. Their molecular mechanisms of energy transduction have been thought to be similar until now. Ca(2+)-ATPase and Na+,K(+)-ATPase are phosphorylated from both ATP and acetyl phosphate (ACP) and dephosphorylated, resulting in active ion transport. However, we found that H+,K(+)-ATPase did not transport proton nor K+ when ACP was used as a substrate, resulting in uncoupling between energy and ion transport. ACP bound competitively to the ATP-binding site of H+,K(+)-ATPase. The hydrolysis of ACP by H+,K(+)-ATPase was stimulated by cytosolic K+, the half-maximal stimulating K+ concentration (K0.5) being 2.5 mM, whereas the hydrolysis of ATP was stimulated by luminal K+, the K0.5 being 0.2 mM. Furthermore, during the phosphorylation from ACP in the absence of K+, the fluorescence intensity of H+,K(+)-ATPase labeled with fluorescein isothiocyanate increased, but those of Na+,K(+)-ATPase and Ca(2+)-ATPase decreased. These results indicate that phosphorylated intermediates of H+,K(+)-ATPase formed from ACP are not rich in energy and that there is a striking difference(s) in the mechanism of energy transduction between H+,K(+)-ATPase and other cation-transporting ATPases.

Adenosine Triphosphatases↗
PubMed1992

A non-haemagglutinating form of Clostridium difficile toxin A.

Analysis of crude culture filtrate of Clostridium difficile by Mono Q-anion exchange fast protein liquid chromatography (FPLC) demonstrated that toxin A had distinct peaks of activity for cytotoxicity and haemagglutination, as also did highly purified toxin A obtained by thyroglobulin affinity chromatography (TG) followed by two sequential anion-exchange chromatographic steps with Q-Sepharose FF and Mono Q. From TG unbound fractions a highly cytotoxic but weakly haemagglutinating variant (toxin A') of toxin A was obtained by Q-Sepharose FF and Mono Q chromatography. Analysis of toxins A and A' from cultures of C. difficile in a chemically defined medium, and of toxin A dialysed against brain heart infusion broth, indicated that A' was not merely toxin A coupled to a component of the growth medium. Polyacrylamide gel electrophoresis under non-denaturing conditions showed that toxins A and A' had the same Mr. Immunoblotting with mouse monospecific A antitoxin showed that five bands larger than the major 240-Kda band were more strongly developed in toxin A than in A' in denaturing but non-reducing conditions, and in reducing conditions eight bands (38-175 Kda) were seen in toxin A but not A'. Immunoblotting with a monoclonal antibody (PCG-4) showed that, in both reducing and non-reducing conditions, two bands of 160 and 155 Kda were more prominent in toxins A and A' respectively, and four bands (195, 180, 175 and 125 Kda) were detected only in toxin A'.

Animals↗