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Biomedical subjects

S Horiuchi

Publications and source records attributed to S Horiuchi.

At least 253 records · Page 14Linked to original sources
PubMed1992

The effects of interferon-beta on phorbol ester or calcium ionophore-induced intercellular adhesion molecule-I expression in epidermal carcinoma cells.

Keratinocyte intercellular adhesion molecule (ICAM)-I expression is induced by interferon (IFN)-gamma. It has been previously reported that IFN-beta suppresses IFN-gamma-induced ICAM-I expression in A431 cells, a human squamous cell carcinoma cell line. In this study, the suppression mechanisms were investigated at the post second messenger level. Both 12-O-tetradecanoylphorbol-13-acetate (TPA) and calcium ionophore (A23187) induce ICAM-I expression in A431 cells. ICAM-I expression induced by either was not suppressed with cotreatment with IFN-beta. Furthermore, IFN-beta did not inhibit the translocation of protein kinase C (PKC) by TPA. It appears that the pathways involved in ICAM-I expression induced by activation of PKC or increased in intracellular Ca++ are not affected by IFN-beta.

Calcimycin↗
PubMed1992

Type 1 pili enhance the invasion of Salmonella braenderup and Salmonella typhimurium to HeLa cells.

The relationship between type 1 pili-associated adhesion and invasion to HeLa cells by Salmonella braenderup and S. typhimurium was studied. When the clinical isolates of these strains were grown in L-broth, they showed both type 1 pili formation and mannose-sensitive adhesion to HeLa cells. On the other hand, the type 1 pili-defective mutants, which were obtained either by repeated subcultures on L-agar plates or by the transposon Tn1-insertion mutagenesis of the S. braenderup and S. typhimurium strains, concomitantly lost mannose-sensitive adhesion to HeLa cells. When the HeLa cells were incubated with Salmonella, the type 1 piliated strains invaded the HeLa cells with much higher infection rate than did the type 1 pili-defective strains. The invasion of type 1 piliated strains to HeLa cells was markedly inhibited in the presence of D-mannose. The infectivity of the strain, which lost type 1 pili but still had mannose-resistant adhesion, was slightly higher than that of the strains defective in both mannose-sensitive and mannose-resistant adhesion. These results suggested that type 1 pili have a role in enhancing the invasion of S. braenderup and S. typhimurium to HeLa cells.

Acute Disease↗
PubMed1992

[In vitro antimicrobial activity of DR-3355, a new quinolone antibacterial agent, against clinical isolates of enteritis-causing bacteria].

We determined the minimum inhibitory concentration (MIC) of DR-3355, a newly developed quinolone-derivative antibacterial agent, against clinical isolates of various bacterial species from enteritis patients, and compared them with those of ofloxacin (OFLX), ciprofloxacin (CPFX), nalidixic acid (NA), ampicillin (ABPC), kanamycin (KM). MIC90 of DR-3355 against 94 strains of Shigella spp. and 5 strains of Escherichia coli, 36 strains of Salmonella spp., 22 strains of Vibrio cholerae, 5 strains of Vibrio parahaemolyticus, and 19 strains of Campylobacter jejuni were 0.05, 0.10, 0.0025, 0.39, and 0.78 micrograms/ml, respectively. These values were 1/2 of that of OFLX, and two times of that of CPFX. MIC90 of DR-3355, OFLX and CPFX against C. jejuni were 0.78 micrograms/ml. MIC90 of DR-3355 against isolates from enteritis patients except for Vibrio spp., were 1/30 to 1/60 of those of NA, ABPC, and KM.

Bacteria↗
PubMed1992

[Thrombosis of the posterior scrotal vein: report of two cases].

A 47-year-old architect and a 30-year-old designer of audio goods presented with thrombosis of left and right posterior scrotal vein, respectively. Both had scrotal masses associated with a feeling of heaviness. Physical, operative and microscopic findings were similar. The lesions were palpated as nontender, slender, elastic masses and located parallel to the urethra in the posterior aspect of the scrotum. At surgical exploration the lesions appeared to be thrombosis of posterior scrotal vein and were removed. Both patients have remained well one year in one and four months in the other after operation. Pathological diagnosis for both surgical specimens was organized thrombosis of vein with eosinophilic infiltration. Eosinophilic infiltration to lesions in the present cases and the occupation of patients suggested that some immunological disorders and localized venous stasis for long time during their sitting work might relate to the formation of thrombosis in the posterior scrotal vein. To our knowledge this is the first report of thrombosis of the posterior scrotal vein.

Adult↗
PubMed1991

Immunochemical approach to characterize advanced glycation end products of the Maillard reaction. Evidence for the presence of a common structure.

Reaction of protein amino groups with glucose (the Maillard reaction) leads from early stage products such as Schiff base and Amadori products to advanced glycation end products (AGE), structures implicated in diabetic complications and the aging process. We have prepared the polyclonal anti-AGE antibody and the monoclonal anti-AGE antibody against AGE-bovine serum albumin and made an immunochemical approach to characterize AGE structures. Both polyclonal and monoclonal antibodies reacted with AGE-proteins such as AGE-bovine serum albumin, AGE-human serum albumin, and AGE-hemoglobin but not with unmodified counterparts. Treatments of these AGE-proteins with borohydride had no effect on the immunoreactivity. Moreover, fructosyl-epsilon-caproic acid, a synthetic Amadori compound, did not serve as an antigen, indicating that these antibodies were specific for AGE products but not for early stage products of the Maillard reaction. In addition, these antibodies were also able to recognize AGE products prepared either from alpha-tosyl-1-lysine, alpha-tosyl-1-lysine methyl ester, monoaminocarboxylic acid such as epsilon-aminocaproic acid, gamma-amino-n-butyric acid, and beta-alanine. Thus, these results strongly suggest the presence of a common structure in AGE preparations, regardless of whether AGE products are generated from proteins, amino acids, or monoaminocarboxylic acids.

Antibodies, Monoclonal↗
PubMed1991

Chemical cross-linking alters high-density lipoprotein to be recognized by a scavenger receptor in rat peritoneal macrophages.

Rat peritoneal macrophages possess a surface receptor for high-density lipoprotein (HDL). To obtain the functional aspect of the HDL receptor, the present study was undertaken to modify HDL with three different cross-linkers; dimethylsuberimidate, disuccinimidylsuberate and dithiobissuccinimidylpropionate (DSP) and determine their effect on the ligand activity for the HDL receptor. Upon modification at a low reagent concentration, DSP was found to be most effective in cross-linking of HDL apolipoproteins. The ligand activity of DSP-HDL for the HDL receptor was reduced by greater than 60%. Experiments with these macrophages at 37 degrees C showed; (i) the amounts of the cell-associated [125I]DSP-HDL as 3.5-fold higher than [125I]HDL; (ii) the cell-association of [125I]DSP-HDL was effectively (greater than 70%) inhibited by unlabeled DSP-HDL, whereas HDL showed a partial inhibition (30%); (iii) [125I]DSP-HDL underwent chloroquine-sensitive intracellular degradation; and (iv) DSP-HDL induced a 3-fold increase in the incorporation of [14C]oleic acid into cholesteryl oleate when compared with unmodified HDL. Experiments at 0 degrees C showed that the cellular binding of [125I]DSP-HDL was competed by acetylated low-density lipoprotein and dextran sulfate. These findings indicate that DSP-HDL is recognized as a ligand by a scavenger receptor of rat peritoneal macrophages, a notion consistent with HDL modified with tetranitromethane (Kleinherenbrink-Stins, M.F. et al. (1989) J. Lipid Res. 39, 511-520).

Animals↗
PubMed1991

Biochemical demonstration of endocytosis and subsequent resecretion of high-density lipoprotein by rat peritoneal macrophages.

To investigate the post-binding events of high-density lipoprotein (HDL), rat peritoneal macrophages were enriched by collagen gel-coated plates and incubated in a cell-suspension system with fluorescein isothiocyanate-labeled HDL (FITC-HDL), followed by fluorescence spectroscopic analyses. Upon incubation with FITC-HDL at 37 degrees C for 30 min, the microenvironmental pH of the cell-associated FITC-HDL was 6.50, whereas a 0 degree C-incubation gave a corresponding pH of 7.15. Carbonyl cyanide m-chlorophenylhydrazone, a protonophore known to dissipate the proton gradient, restored the former acidic pH (pH 6.40) to pH 7.20, but had no effect on the latter. This indicates that cell surface-bound HDL is internalized and exposed to an acidic compartment. When cells were incubated with FITC-HDL at 37 degrees C for 30 min and the cell-associated FITC-HDL was chased at 37 degrees C, the fluorescence intensity at 490 nm showed a time-dependent increase. This increase was explained by a release of endocytosed FITC-HDL into the extracellular medium but not by a simple outward dissociation of the cell-associated FITC-HDL. The microenvironmental acidic pH of the cell-associated FITC-HDL changed to a less acidic pH during the chase whereas that of FITC-HDL became constant after released into the medium, indicating that endocytosed HDL was resected back into the extracellular medium. This resection process was temperature-dependent and accelerated by HDL itself. These results provide the biochemical evidence for the presence of an endocytic-exocytic pathway for HDL in rat peritoneal macrophages.

Animals↗
PubMed1991

Acid proteinases of the fore-gut in metamorphosing tadpoles of Rana catesbeiana.

1. Two types of acid proteinases were found in the adult stomach of the bullfrog, Rana catesbeiana. 2. The first type of enzyme appeared in the developing stomach and esophagus and contained more than two kinds of acid proteinases. 3. These enzymes were identified as pepsin-type enzymes. 4. The second type of enzyme existed from the larva to adult stage and was also present in the adult duodenum. 5. This enzyme was different from pepsin and thought to be cathepsin E.

Animals↗
PubMed1991

The 106-kilobase plasmid of Salmonella braenderup and the 100-kilobase plasmid of Salmonella typhimurium are not necessary for the pathogenicity in experimental models.

Among 1.041 clinical isolates (77 serovars) of Salmonella which had been derived from cases with acute enterocolitis, 601 (58%) contained one or more plasmids. Large serovar-specific plasmids were seen in 95 of 307 isolates (31%) of Salmonella typhimurium, in 34 of 34 isolates (100%) of Salmonella enteritidis and in 36 of 38 isolates (94.7%) of Salmonella braenderup: the sizes of which were 100, 60 and 106 kilobases (kb), respectively. In order to determine the role of these plasmids in pathogenicity for enterocolitis, the plasmids were eliminated from some strains of S. braenderup and S. typhimurium and the pathogenicity of the plasmid-less strains was compared with that of the parent strains by invasiveness to HeLa cells, fluid accumulation in the rabbit ligated ileal loop, lesion of mucosal tissue and the Sereny test. The virulence of all the plasmid-less strains was as strong as that of the plasmid-bearing strains in these pathogenicity assay systems. We therefore concluded that the 106-kb plasmid of S. braenderup and the 100-kb plasmid of S. typhimurium are not necessary for their pathogenicity in the experimental models: invasiveness to HeLa cells, fluid accumulation in the rabbit ligated ileal loop, and Sereny test.

Animals↗
PubMed1991

[In vitro antimicrobial activity of rokitamycin, a macrolide antibacterial agent, against clinically isolated strains of Campylobacter and other enteritis-causing bacteria].

We determined the minimum inhibitory concentrations (MICs) of rokitamycin (TMS-19-Q, RKM), a macrolide antimicrobial agent, against strains of various bacterial species isolated from enteritis patients, and compared them with those of josamycin (JM), erythromycin (EM) and ofloxacin (OFLX). MIC90 of RKM against 147 strains of Campylobacter jejuni, and each 25 strains of Shigella spp., Salmonella spp. and diarrheagenic Escherichia coli were 1.56, 200, 800 and 200 micrograms/ml, respectively. There was only one RKM resistant (MIC greater than 100 micrograms/ml) C. jejuni strain, while most of the strains of the other species were resistant to RKM. MIC values of the other drugs were all similar to those of RKM. MIC90 of OFLX against 147 strains of C. jejuni was 0.78 micrograms/ml, lower than other drugs.

Campylobacter↗
PubMed1991

[Concentration of nitrosodimethylamine in commercial pelleted experimental animal diets].

To know the conditions of contamination by the chemicals in the experimental animal diets, the contents of nitrosodimethylamine (NDMA) were analyzed in the diets for mice and rats. The raw materials of the diets were also analyzed. In addition, NDMA levels were determined in the diets which were stored long or heated in the autoclaves. The averages of NDMA in these diets were less than 10 ppb. In the raw materials, alfalfa contained a higher levels of NDMA. There was no clear tendency of increase or decrease in NDMA levels, when the diets were stored for six months at room temperature (23-25 degrees C) or at low temperature (7-10 degrees C). Heating the diets at 121 degrees C, no remarkable changes were observed in NDMA levels. It seems that little adverse influences on the conduct of the animal experiments would be anticipated by the NDMA in the commercial diets.

Animal Feed↗
PubMed1991

[A study of the metabolism of vitamin D in patients with renal cell carcinoma--with special reference to serum concentration of 1 alpha, 25-(OH)2D and its clinical significance].

Recently it has been known that the active form of vitamin D, 1 alpha, 25-dihydroxyvitamin D (1 alpha, 25-(OH)2D), plays some immunological roles in controlling cell differentiation and carcinogenesis. Moreover, 1 alpha, 25-(OH)2D is said to have some effects in the changes of several numbers of oncogenes. In this study, the serum concentrations of 1 alpha, 25(OH)2D and 25-hydroxyvitamin D (25-(OH)2D) were measured in 30 patients with renal cell carcinoma. The two vitamin D metabolites were separated and purified using high performance liquid chromatography, and each fraction was subjected to competitive protein binding assay using vitamin D deficient rat serum for 25-(OH)2D and chick embryo intestinal receptors for 1 alpha, 25-(OH)2D as the binder. The average concentration of serum 1 alpha, 25-(OH)2D was 28.9 +/- 5.2 pg/ml for controls whereas the average in patients with renal cell carcinoma was 19.7 +/- 5.9 pg/ml. The concentration of 1 alpha, 25-(OH)2D was significantly lower in the patients with renal cell carcinoma compared to in the controls (p less than 0.01). The average concentrations of serum 25-(OH)2D had no significant differences between the two groups. Comparison between the stage I + II and stage III + IV, T1 + T2 and T3 + T4, rapid type and slow type groups showed that the average serum 1 alpha, 25-(OH)2D concentrations was significantly lower in the stage III + IV, T3 + T4, and rapid type groups compared to the other groups (p less than 0.01, p less than 0.05, p less than 0.01). And besides there were no significant correlations between the concentration of serum 1 alpha, 25-(OH)2D and creatinine clearance in patients with renal cell carcinoma. Taken together, it is suggested that the serum concentration of 1 alpha, 25-(OH)2D is in some way correlated with the progression of renal cell carcinoma.

Adult↗
PubMed1991

Measurement and analysis of cohort-size variations.

"This article discusses two measures of cohort-size variations: the age-standardized cohort size, and the growth rate of the number of births.... The usefulness of the two measures in analysing recent demographic trends is demonstrated....[The author] discusses meanings and usefulness of the ratio of the crude birth rate (CBR)/total fertility rate (TFR) in studying the effects of age structure changes on population growth." The geographical scope is worldwide, with particular attention to China, Indonesia, Japan, the Philippines, and Thailand.

Age Distribution↗
PubMed1991

Assessing the effects of mortality reduction on population ageing.

"This article presents a new method for decomposing age distribution changes into changes in the number of births and changes in age-specific rates of mortality and migration. The method is developed on the basis of the equation for the age-specific growth rate proposed by Horiuchi and Preston (1988). Using this method, it is shown that the increase in the proportion of women in Japan during 1970-1980 is mainly due to the reduction of mortality, particularly at old ages. The results lend support to the proposed idea that the pattern of age structure changes in developed countries is now shifting from fertility-dominated to mortality-dominated ageing." This is a revised version of a paper originally presented at the 1989 Annual Meeting of the Population Association of America.

Age Distribution↗
PubMed1991

Pyrogenic responses of the pika, Ochotona rufescens rufescens.

In 3-month-old male and female pikas, Ochotona rufescens rufescens, reared at an ambient temperature of 25 degrees C, the mean within-day body temperature was 39.2 degrees C without significant variance. At an ambient temperature of 35 degrees C it increased markedly in males while decreased slightly at 5 degrees C. The pikas showed lower sensitivity than Japanese white rabbits to a pyrogenic E. coli endotoxin.

Animals↗
PubMed1991

[A case of infantile Sertoli cell tumor].

A case of infantile Sertoli cell tumor of the testis is presented. A 2-year-old child visited our hospital with the complaint of painless swelling of the left scrotal content. A solid tumor was demonstrated in the left testis by scrotal echography. Physical and laboratory examinations were within normal limits and alpha-fetoprotein and beta-HCG were not elevated. The left testis was removed. The tumor sized 3.0 x 3.0 x 2.2 cm and weighted 14.5 g. Pathohistological diagnosis was benign Sertoli cell tumor. Tumor cells were vimentin positive and TM-1 reactive antigen positive and revealed electronmicroscopically some features of Sertoli cells such as intermediated microfilament, rich lysosomes and interdigitation between adjacent cells. The patient was well with no evidence of diseases one and a half years after the operation.

Age Factors↗
PubMed1990

Microquantification of cholesterol and cholesteryl esters in rat peritoneal macrophages by reverse-phase high-performance liquid chromatography.

A simple and rapid method for the microquantification of cholesterol and cholesteryl esters by reverse-phase high performance liquid chromatography has been established. Comparison of elution patterns of authentic cholesterol and cholesteryl esters revealed that a mu Bondasphere reverse-phase C8 (300-A) column was more suitable than a corresponding reverse-phase C4 or C18 column in terms of rapidity and sensitivity. Recovery of cholesterol and cholesteryl esters from a C8 column was greater than 98% when determined either by radioactive cholesterol and cholesteryl oleate or by cholesteryl heptadecanoate. The sensitivity of the quantification ranged from 5 ng to 50 micrograms for both cholesterol and cholesteryl esters. This method was applied to determination of cellular cholesterol and cholesteryl esters of rat peritoneal macrophages. Lipid extracts of these cells were found to contain 38.01 +/- 2.60 micrograms of cholesterol and 3.18 +/- 0.36 micrograms of cholesteryl esters per milligram of cell protein. When the cells were loaded with cholesteryl esters by incubation for 24 h with various concentrations of acetylated low-density lipoprotein, a cellular level of cholesteryl esters showed a dose-dependent increase and reached a maximal level of 106.60 +/- 3.05 micrograms/mg cell protein. Thus, the present method is useful for the microquantification of cholesterol and cholesteryl esters from lipid extracts of biological samples.

Animals↗