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Biomedical subjects

S Horiuchi

Publications and source records attributed to S Horiuchi.

At least 271 records · Page 15Linked to original sources
PubMed1990

Purification and characterization of inhibitor against the cysteine proteinase of Rana catesbeiana.

1. Inhibitors of cysteine proteinase were found in tadpole tail of metamorphosing bullfrog. 2. One of the inhibitors was purified by affinity chromatography with CM-papain agarose, gel filtration with Superose 12 and ion exchange chromatography with Mono S. 3. The molecular weight of the inhibitor was 130,000-140,000 and the isoelectric point was pH 9.6. 4. The inhibitor had inhibitory effects on ficin, papain and tadpole tail cysteine proteinase. 5. The inhibitor is possibly involved in the regulation of muscle degradation in tail regression of metamorphosing tadpole.

Animals↗
PubMed1990

Age patterns of mortality for older women: an analysis using the age-specific rate of mortality change with age.

"In this paper we propose a mortality measure that seems useful in analyzing age patterns of death rates. The measure, which will be denoted by k(x), indicates the proportional increase or decrease with age in the risk of death at a given age x, and is called the age-specific rate of mortality change with age." Estimations are presented for women in 10 countries. "Eight of the selected sets of data are for developed nations in the 1960s and 1970s, and the other two sets of data, for Taiwan, 1931-35, and for Germany, 1910-11, represent relatively high mortality. For France and West Germany, three different periods are included for an investigation of cohort effects on the observed age patterns." Other mathematical models of age-specific mortality rates are discussed and compared. (SUMMARY IN FRE)

Adult↗
PubMed1990

[Experimental stomach-ulcer on pika].

Experimental gastric ulcer formation was performed in the pika and compared with that in the rat. Gastric ulcers were formed in pika that were subjected to water restraint for 4-5 days for 2 hours each day. Gastric ulcers were also formed under conditions of 1-4 days for 3 hours each day and 1-2 days for 5 hours each day. The severest (widest) ulcers were obtained under the condition of 5 hours' water restraint. Histopathologically, the ulcers were mostly erosions, but those formed under 5 hours' restraint reached the tunica muscularis mucosae. In addition, inflammatory changes were recognized. In contrast, while gastric ulcers in the rat formed within a short time, they were histopathologically less severe than those in the pika. Therefore, water restraint for 4 hours performed 4-5 times is suitable to obtain gastric ulcer formation in the pika and may result in more severe gastric ulcers than in the rat. Compared with the rat, the pika showed differences in the appearance and degree of gastric ulcers formed by the injection of serotonin and reserpine.

Animals↗
PubMed1990

Cholesterol uptake by human glioma cells via receptor-mediated endocytosis of low-density lipoprotein.

Low-density lipoprotein (LDL) is a carrier of the cholesterol found in human plasma. Cells utilize cholesterol for membrane synthesis by taking up LDL via receptor-mediated endocytosis. In the present study, interactions of LDL with human malignant glioma cell lines (U-251 MG and KMG-5) were investigated biochemically and morphologically. The LDL, labeled with the fluorescent dyes 1,1'-dioctadecyl-3,3,3',3'-tetramethylindocarbocyanine (DiI) and fluorescein isothiocyanate (FITC), was internalized by both cell processes and cell bodies. Reductive methylation of DiI-labeled LDL, which abolishes the ability of the cell to bind to the LDL receptor, prevented the internalization of the cholesterol moiety of LDL. Cellular binding of 125I-LDL to U-251 MG cells at 4 degrees C revealed the presence of a specific saturable-associated receptor (dissociation constant (Kd) approximately 38 micrograms/ml). Endocytic uptake of 125I-LDL or 3H-cholesterol oleate-labeled LDL (3H-LDL) at 37 degrees C demonstrated the cell-associated 125I-LDL and 3H-LDL increase. The intracellular degradation of protein moiety increased linearly with time. Reductive methylation of 3H-LDL led to a remarkable decrease in the cell-associated cholesterol moiety of LDL. The difference in uptake of the cholesterol moiety of LDL between U-251MG cells and KMG-5 cells showed that the U-251MG cells, which proliferate more actively than KMG-5 cells, take up more of the cholesterol moiety of LDL than do the KMG-5 cells. Thus, LDL cholesterol seems to be endocytosed predominantly via the LDL receptor present on the plasma membrane of malignant glioma cells. In addition, for growth, these cells may require large amounts of the cholesterol moiety of LDL.

Brain Neoplasms↗
PubMed1990

A consideration of salt intake from foods based on the simultaneous measurement of sodium and chlorine by neutron activation analysis.

Ordinary hospital meals for adults were simultaneously measured for Na and Cl by neutron activation analysis (NAA). Results obtained are summarized as follows: 1. Daily Na intake was estimated to be 4 to 8 g, corresponding to 11 to 18 g of salt. Daily Cl intake was estimated to be 5 to 9 g, corresponding to 7 to 12 g of salt. Their ratio was 1.6. 2. The higher values of salt intake obtained by conversion from Na intake are attributable to food additives. 3. In rating Na content, which has been reported to affect blood pressure, on the basis of salt intake, attention must be given to the fact that salt content converted from Cl content is rated to be lower than that converted from Na content.

Chlorine↗
PubMed1990

[Effect of tegafur administration combined with hormonal therapy in patients with newly diagnosed stage D prostatic cancer].

To study the effect of tegafur administration combined with hormonal therapy on the survival rate of newly diagnosed patients with stage D prostatic cancer, 66 patients, 70.9 years old in mean age, were treated from 1979 to 1986. The cancer was proven by the histological or cytological examination of the specimen which was obtained by the needle biopsy and/or aspiration biopsy of the prostate. The histopathological diagnosis of 59 patients was as follows: well differentiated type of adenocarcinoma was observed in 13 patients, moderately differentiated type in 19 cases, poorly differentiated type in 24 cases and mixed type in 3 cases. Daily 600 mg tegafur was administered orally as long as possible from the beginning of the treatment combined with hormonal therapy. Actual and relative 5 year survival rates calculated with Kaplan-Meier's method were 31.2% and 39.2%, respectively. When deaths other than prostatic cancer death were counted as lost cases, the actual survival rate was 47.5%. The present study also demonstrated that there were some factors affecting the patients' prognosis. They were the age of onset of the disease (patients under 64 years old were worse than those over 65 years old; p less than 0.05), performance status (patients with PS from 0 to 2 at the first admission were better than those with PS 3 to 4; p less than 0.025), differentiation of the tumor (well differentiated type was better than moderately; p less than 0.025 or poorly differentiated type; p less than 0.005).

Adenocarcinoma↗
PubMed1990

[Biological features of the skin of the pika, Ochotona rufescens rufescens--concentration of histamine in the skin].

The quantity of histamine and the number of mast cells in the skin of the pika were measured and compared with rabbits, guinea pigs and rats. The ranking of regional histamine levels in the skin of the pika was: perianal region greater than abdomen greater than interscapular region = back greater than lumbus greater than head greater than auricle, and the average value of the 7 regions was 22.6 micrograms/g. The level of histamine in the 6 regions, except the auricle, was 2-5 times that of rabbits and guinea pigs. In the auricle of each of the 4 kinds of animal (pika, rabbit, guinea pig and rat), the levels were almost identical. With respect to histamine levels, those in the pika resembled those in rats. The number of mast cells in the skin of the pika was less than in rats, and was greater than that in rabbits and guinea pigs. The average value was 9.9/mm2.

Animals↗
PubMed1989

Scavenger receptor of human monocytic leukemia cell line (THP-1) and murine macrophages for nonenzymatically glycosylated proteins.

Long-term incubation of proteins with glucose undergo a series of nonenzymatic reactions to form advanced glycosylation end product (AGE) with fluorescence and brown color. The receptor for AGE-proteins was demonstrated in murine macrophages (Vlassara et al. (1985) Proc. Natl. Acad. Sci. USA 82. 5588). Our recent study with rat macrophages revealed that the receptor also recognized proteins modified with aliphatic aldehydes such as formaldehyde or glycolaldehyde, indicating its close identity to a scavenger receptor for aldehyde-modified proteins (Takata, K. et al. (1988) J. Biol. Chem. 263. 14819). This notion was tested in the present study with human monocytic leukemia cell line (THP-1 cells), human monocyte macrophages and murine peritoneal macrophages. Endocytic uptake of AGE-proteins and aldehyde-modified proteins was inhibited in a cross-competitive fashion. The receptor activities of THP-1 cells for AGE-albumin and aldehyde-modified proteins were induced synchronously by phorbol 12-myristate 13-acetate. Furthermore, upon reduction by NaBH4 of the Schiff base formed between proteins and glucose or aldehydes, no ligand activity was generated. However, once the ligand activity was generated, NaBH4 was no longer effective for the ligand activity. Thus, a structure in common between AGE-proteins and aldehyde-modified proteins may be crucial for recognition by the human macrophage receptor.

Animals↗
PubMed1989

Protective effect of lipoproteins containing apoprotein A-I on Cu2+-catalyzed oxidation of human low density lipoprotein.

Two apoprotein A-I (apoA-I)-containing lipoproteins, one containing apoA-I and apoA-II (LpA-I/A-II) and the other containing only apoA-I (LpA-I), were examined for their effect on Cu2+-mediated oxidation of low density lipoprotein (LDL). The presence of LpA-I or LpA-I/A-II prevented LDL oxidation when assessed by the electrophoretic mobility, apoprotein B fragmentation and amounts of thiobarbituric acid-reactive substances. The protection of LDL oxidation by these lipoproteins was effective for up to 6 h, with LpA-I being more active than LpA-I/A-II. Results from these in vitro model experiments raise a possibility that LpA-I may play a role in protecting LDL from Cu2+-mediated oxidation.

Apolipoprotein A-I↗
PubMed1989

Scavenger receptor-mediated recognition of maleylated albumin and its relation to subsequent endocytic degradation.

Rat sinusoidal liver cells take up maleylated bovine serum albumin (maleyl-BSA) and its demaleylated form (demaleyl-BSA) by scavenger receptor-mediated endocytosis. Cellular binding of maleyl-BSA and demaleyl-BSA and its quantitative relation to subsequent intracellular degradation were investigated. The binding affinities of these ligands were almost equal whereas the number of binding sites for maleyl-BSA was more than twice as large than that for demaleyl-BSA. However, no difference was observed in their endocytic degradation. The amounts of maleyl-BSA degraded were proportional to those bound to the cell surface up to a certain level. However, a further increase in cell-bound ligands did not affect the degradation of maleyl-BSA. Several polyanions such as fucoidin and dextran sulfate of Mr = 5000 inhibited the binding of maleyl-BSA but did not affect its degradation. In contrast, acetylated or oxidized low density lipoprotein had virtually no effect on cellular binding of maleyl-BSA but exhibited profound effects on its intracellular degradation. Similar results were obtained with rat peritoneal macrophages. Based on these data, we would propose that two binding sites are involved in the receptor-mediated ligand recognition; one is coupled to subsequent endocytic degradation, and the other serves as a binding site for polyanionic compounds.

Albumins↗
PubMed1989

Antibodies to an NH2-terminal myristoyl glycine moiety can detect NH2-terminal myristoylated proteins in the retrovirus-infected cells.

Novel antibodies were raised against a synthetic NH2-terminal myristoyl glycine moiety which is characteristic of N-myristoyl-proteins. Antisera raised against N-myristoyl-Gly-hemocyanin reacted with N-myristoyl-Gly-[125I]albumin. The immunoreaction was competed for by albumin conjugated with N-myristoyl-glycine, while underivatized albumin had no effect. Of the [3H]myristate-labeled proteins detected, pp60v-src, which is a transforming protein of Rous sarcoma virus, and p19gag and p17gag, which are core proteins in the human T-cell leukemia virus and the human immunodeficiency virus, were identified as N-myristoylated proteins by the radioimmunoprecipitation analyses with the antibody.

Amino Acid Sequence↗
PubMed1989

Intracellular accumulation of cholesteryl esters suppresses production of lipopolysaccharide-induced interleukin 1 by rat peritoneal macrophages.

Interleukin 1 (IL-1) is a major cytokine of macrophages secreted by several stimulants such as lipopolysaccharide (LPS). Macrophages are known to possess the scavenger receptor for acetylated low density lipoprotein (acetyl-LDL) and maleylated albumin. In the present study we determined effects of these ligands on LPS-induced IL-1 production by rat peritoneal macrophages. These ligands themselves did not induce IL-1 production. However, upon short incubation with acetyl-LDL, LPS-induced IL-1 production was significantly suppressed. The extent of the suppression was proportional to cellular cholesteryl esters. Thus, intracellular accumulation of cholesteryl esters might be responsible for suppression of LPS-induced IL-1 production.

Albumins↗
PubMed1989

Regional ligand domain is involved in scavenger receptor-mediated recognition of maleyl-albumin by rat sinusoidal liver cells.

Scavenger receptor-mediated endocytosis of maleyl-albumin was studied with rat sinusoidal liver cells. Upon maleylation of greater than 28 mol lysine residues per protein, bovine serum albumin became an active ligand. Further modification of up to 37 mol lysine residues per protein resulted in a sharp increase in the ligand activity, reaching a maximum level thereafter. Removal of maleyl moieties from maleyl-albumin (demaleylation) from 53 mol to 14 mol lysine residues per protein did not affect the ligand activity. However, further demaleylation to less than 5 mol lysine residues per protein led to complete loss of the ligand activity. Thus, the covalently incorporated maleyl moieties are needed for the ligand activity. The ligand activity was also generated when two peptides (Frag N and Frag C) from cyanogen bromide-cleaved albumin were maleylated, indicating that the formation of an active ligand would not require a whole albumin molecule. Maleyl Frag C was further separated into three peptides; maleyl Frag C-1 (261 amino acid residues), maleyl Frag C-2 (102 residues) and maleyl Frag C-3 (36 residues). The cellular binding and endocytic degradation of maleyl-albumin or acetylated low density lipoprotein were effectively competed for by maleyl Frag C-1 and maleyl Frag C-2 but not by maleyl Frag C-3. Thus, regional domains might be involved in the ligand recognition by the scavenger receptor.

Albumins↗
PubMed1989

A novel antibody against a synthetic NH2-terminal myristoyl glycyl src peptide can detect pp60v-src, the transforming protein of Rous sarcoma virus.

Novel antibodies were raised against a synthetic NH2-terminal myristoyl(Myr-) tetrapeptide(N-Myr-Gly-Ser-Ser-Lys) which is characteristic of an NH2-terminal portion of pp60v-src, the transforming protein of Rous sarcoma virus. Antisera raised against N-Myr-Gly-Ser-Ser-Lys-haemocyanin reacted with 125I-albumin conjugates with N-Myr-Gly-Ser-Ser-Lys. The immunoreaction was competed for by haemocyanin as well as albumin conjugated with this N-Myr-peptide, while underivatized proteins or an NH2-terminal octapeptide (Gly-Ser-Ser-Lys-Ser-Lys-Pro-Lys) had no effect. N-Myr-Gly-Ser-Ser-Lys-(125I)tyramine was also recognized by the antibody. The reaction was competed for by N-Myr-Gly-Ser-Ser-Lys, but not by Gly-Ser-Ser-Lys-Ser-Lys-Pro-Lys. These results suggest a high affinity of the antibody for an N-Myr-peptide moiety. The major (3H)myristate-labelled protein of an apparent molecular weight of 60,000 was detected from chick embryo fibroblasts transformed by Rous sarcoma virus (tsNY68). This protein was demonstrated to possess N-Myr-Gly-Ser-Ser-Lys by the immunoprecipitation and HPLC analyses. Furthermore, the entire circumference of the transformed cells was stained by the antibody upon an immunofluorescent microscopic observation. Thus, these results taken together indicate that the haptenic antibody raised against the myristoyl peptide is useful to detect pp60v-src protein.

Amino Acid Sequence↗
PubMed1989

Partial purification and characterization of CA19-9 antigen from the ascitic fluid of a patient with pancreatic cancer.

CA19-9 immunoreactive protein was partially purified from the ascitic fluid of a patient with pancreatic cancer by perchloric acid fractionation, gel chromatography and Affi-gel Blue column chromatography, resulting in a purified sample of 5.0 x 10(6) CA19-9 units per milligram of protein (3700-fold purification). Western blotting analysis of this purified sample revealed a single band of molecular weight 210 kDa. Although the original ascitic fluid showed a high CA125 immunoreactivity, this purified sample had no CA125 immunoreactivity. The elution pattern for CA19-9 activity on Affi-gel Blue column is quite distinct from that for CA125. These results suggest that CA19-9 antigen in carcinoma patients may be identical or very similar to that recently purified from the culture media of the colorectal cell line SW1116 and is distinct from CA125 antigen.

Antigens, Tumor-Associated, Carbohydrate↗