Biomedical subjects

H Taniguchi

Publications and source records attributed to H Taniguchi.

At least 523 records · Page 29Linked to original sources

PubMed1989

Catalytic subunit of cAMP-dependent protein kinase from bovine heart: several isoforms demonstrated by high resolution focusing in immobilized pH gradient.

The catalytic subunit (C) of cAMP-dependent protein kinase holoenzyme type II from bovine cardiac muscle was separated by isoelectric focusing in Immobiline polyacrylamide gels into 9 protein forms. The major forms (i) appeared at pH 7.1, 7.4, 7.5, and 7.7, (ii) exhibited protein kinase activity and were inhibited by heat and acid stable inhibitor, (iii) represented approx. 30%, 4%, 64%, and 1% of the protein respectively, (iv) refocused in the same position from which they had been eluted from the first gel. Antibodies against C detected additional proteins at approx. pH 7.55, 7.75, and 7.8. Two more bands became detectable at approx. pH 7.3 and 7.45 by application of antibody against C beta (Uhler, M.D. & McKnight G.S. 1987, J.Biol.Chem. 262, 15202-15207). The relation of the different forms of C to the fractions CA and CB (Kinzel V. et al. 1987 Arch. Biochem. Biophys. 253, 341-349) is demonstrated.

Acrylamides↗

PubMed1989

Prospective evaluation of diagnostic accuracy of gastrofiberscopic biopsy in diagnosis of gastric cancer.

The accuracy of gastrofiberscopic biopsy in diagnosis of gastric malignancies has been evaluated by studying operative and postmorten findings and clinical follow-up data in linkages at Osaka Cancer Registry, Japan, after an average of 7.7 years. Satisfactory data were obtained in follow-ups of all 1331 patients examined. There were only 31 (3.7%) false-negative diagnoses of malignancy among 858 patients diagnosed as having benign lesions, and only three (0.6%) false-positive diagnoses among 473 patients diagnosed as having malignant tumors. The false-negative diagnoses were most frequent in cases of elevated types of early cancer, advanced cancer of type 4 and leiomyosarcoma, or in cases located in the posterior wall and in the antrum. The three benign lesions that were diagnosed as malignant by biopsy were all associated with active ulceration, indicating that care is necessary in taking biopsy specimens of ulcerated lesions. From these findings the sensitivity and specificity of the gastrofiberscopic biopsy method for detection of gastric malignancies were calculated to be 93.8% and 99.6%, respectively, and the overall accuracy for all the patients was 97.4%. These results reconfirm that gastrofiberscopic biopsy is very useful for diagnosis of gastric malignancies.

Adenocarcinoma↗

PubMed1989

Target antigen of islet cell antibody in Japanese insulin-dependent diabetes mellitus.

The target antigens of islet cell antibody (ICA) have not been clarified. We tried to modify the antigen in human pancreatic tissues and characterize the ICA with immunohistochemical methods. Human pancreatic tissues were treated with periodate (A), borohydride (B), neuraminidase (C), methanol (D), chloroform-methanol (E), or protease (F) to modify the antigens, and stained by an immunofluorescent method using ICA-positive sera from five Japanese insulin-dependent diabetes mellitus (IDDM) patients. In all sera the fluorescence of islets disappeared or waned after A, C, D, and E, and did not change after F. The disappearance or loss of fluorescence induced by A was recovered after B. It is, therefore, suggested that one of the antigens of ICA in Japanese IDDM patients is the sialic acid residue of glycolipid.

Adolescent↗

PubMed1989

Effect of dimethylthiourea on syngeneic rodent islet transplantation.

We studied the effects of a hydroxyl radical scavenger, dimethylthiourea (DMTU), on syngeneic islet grafts. Six hundred fresh islets taken from two Wistar rats were transplanted intraportally into other Wistar rats made diabetic with streptozotocin. DMTU was given to five recipients intraperitoneally for a month while nine controls received only intraperitoneal saline. The DMTU-treated group had significantly lower fasting plasma glucose levels at 1.5, 4.5, 5, 5.5, 6, 7, 9 and 11 weeks and had higher mean fasting body weights between the 2.5th week and their eventual sacrifice. Their islets also survived significantly longer than did those of the controls (73.6 +/- 3.4 vs. 21.6 +/- 9.4 days). This suggests that oxygen free radical production endangers graft survival and that the hydroxyl radical scavenger DMTU protects syngeneic islet grafts.

Animals↗

PubMed1989

Effects of propranolol and cimetidine on cysteamine inhibition of gastric carcinogenesis induced in Wistar rats by N-methyl-N'-nitro-N-nitrosoguanidine.

The effects of propranolol and cimetidine on inhibition by cysteamine (2-aminoethanethiol hydrochloride) of gastric carcinogenesis induced by N-methyl-N'-nitro-N-nitrosoguanidine (MNNG) and on gastric acid secretion, serum gastrin level, and labelling index of the gastric mucosa were investigated in inbred Wistar rats. Rats received alternate-day injections of cysteamine (25 mg/kg body weight) with or without propranolol (dl-propranolol hydrochloride) (2 mg/kg bw) or cimetidine (50 mg/kg bw) in depot form after 25 weeks of oral treatment with MNNG. Prolonged administration of cysteamine significantly reduced the incidence of adenocarcinoma of the glandular stomach. A combination of cysteamine and propranolol significantly accelerated the inhibitory effect of cysteamine on gastric carcinogenesis. However, with concomitant administration of cysteamine and cimetidine, the incidence of adenocarcinoma was slightly but not significantly increased as compared to that after treatment with cysteamine alone. Administration of cysteamine caused a significant increase in gastric acid secretion and serum gastrin level, and a significant decrease in the labelling index of the antral mucosa. A combination of cysteamine and propranolol significantly increased gastric acid secretion by cysteamine alone and significantly decreased the labelling index of the antral mucosa. With this treatment, the serum gastrin level was significantly higher than the basal level, but the stimulated serum gastrin level was significantly lower than observed that after administration of cysteamine alone. In contrast, concomitant administration of cysteamine and cimetidine caused a significant decrease in gastric acid secretion and significant increase in the serum gastrin level as compared to the levels seen after treatment with cysteamine alone, but had no influence on the labelling index of the antral mucosa. These findings indicate that hypersecretion of acid, but not hypergastrinemia associated with hyposecretion of acid or achlorhydria, exerts a protective effect against gastric carcinogenesis, and that this effect may be related to its activity in decreasing proliferation of the antral mucosa.

Adenocarcinoma↗

PubMed1989

Pupillary light reflex in borderline diabetes mellitus.

It is well known that in diabetes mellitus the early phase insulin release response to glucose becomes blunted. Besides, autonomic neuropathy develops frequently. The autonomic nerve function is related to insulin release in normal subjects. Therefore, in the present study the autonomic function was investigated in different degrees of the early phase insulin release response to glucose loading in borderline diabetes mellitus (B-DM) as well as the early stage of diabetes mellitus (E-DM). In our study the pupillary light reflex seemed to be more sensitive for the detection of autonomic neuropathy than the cardiac beat-to-beat variation in B-DM and E-DM. The light reflex, therefore, was used and the following results were obtained. (1) Autonomic neuropathy was detected even in B-DM, though it was slighter than in E-DM. (2) The parasympathetic nerve appeared to be impaired more than the sympathetic in B-DM and this was especially the case in subjects with relatively good insulin release response. Therefore, the suppression of the early phase insulin release in B-DM may be caused by this autonomic neuropathy already present. (3) In B-DM with reduced insulin release autonomic neuropathy seemed to be more advanced and it became more remarkable in E-DM. Particularly the sympathetic abnormality was loaded in this regard. These observations suggest that it is necessary to consider an involvement of autonomic nerve dysfunction for the understanding of the pathogenesis of B-DM.

Adult↗

PubMed1989

Sophisticated mesh filtration technique of a large-scale isolation of islets and their function.

A large-scale isolation of islets is required for islet transplantation. We improved our conventional method, and could obtain about three times more islets than by the conventional methods. Pancreata of adult Wistar rats were inflated by injection of buffer with (A) or without 1.3 mg/ml collagenase (B). The rats were bled from the inferior vena cava and the aorta in (A) simultaneously with the inflation. They were further digested with collagenase and filtered through two different meshes (pore size: 1190 and 590 microns) (A1) or three different meshes (pore size: 1190, 590 120 microns) (A2) in order. Insulin released from islets isolated in this manner was determined by 1-h incubation with 3.3 and 16.7 mM glucose. Besides, 600 islets each were transplanted into the liver of streptozotocin-induced diabetic Wistar rats and their fasting plasma glucose was measured at weekly intervals. (1) With these methods more numerous islets were harvested by A1 (mean: 554) and A2 (mean: 746) than B (mean: 224). (2) Insulin released at both glucose concentrations was similar among islets obtained by A1, A2 and B. (3) The plasma glucose-lowering effect was similar among the islets obtained by these methods. (4) A more selected range of islet sizes was obtained by A2 than A1. These observations indicate that the present techniques (A1 and A2) are less time-consuming and simpler for a large-scale isolation of islets.

Animals↗

PubMed1989

Islet function after storage at -2 degrees C and -196 degrees C.

The radical treatment of type 1 diabetes by transplantation requires the extracorporeal storage of islets, and this has frequently been studied. Damage from ice formation, however, has prevented the development of any satisfactory method for preservation. We compared islet function after frozen storage with that after non-frozen storage. Isolated rat islets immersed in 10% dimethyl sulfoxide were kept at -2 degrees C (group A) and -196 degrees C (group B) for 7 days. After one day of culture, some of the islets were incubated in 3.3 and 16.7 mM glucose-containing Krebs--Henseleit bicarbonate buffer for 60 min. The other islets were incubated with 3H-leucine for 2 h. The radioactivity of whole-islet homogenate and the insulin extracted from it were measured. We also counted the number of islets before and after the 7-day storage. The islets thus preserved were transplanted into streptozotocin-induced diabetic rats and the fasting plasma glucose was determined weekly. Non-cooled islets were used as controls (group C). Insulin release in the presence of 16.7 mM glucose did not significantly differ between groups C and A, whereas it was lower in group B than in groups A or C. The islet uptake of 3H-leucine was lower in A and B compared with C, but the insulin synthesis was similar in all three groups. More islets were recovered from A than B. Fasting plasma glucose was lowered similarly in the diabetic rats after transplantation of islets from A and B. The relative ease of preservation at -2 degrees C, and the positive results of this experiment, favor this method of preservation.

Animals↗

PubMed1989

Enhancement of experimental gastric carcinogenesis induced in spontaneously hypertensive rats by N-methyl-N'-nitro-N-nitrosoguanidine.

The incidence, number, and histological types of gastric cancers induced by N-methyl-N'-nitro-N-nitrosoguanidine and the tissue norepinephrine concentration of the gastric wall were investigated in spontaneously hypertensive rats and in control Wistar Kyoto rats and Wistar rats. All rats were given drinking water containing 25 micrograms/ml of N-methyl-N'-nitro-N-nitrosoguanidine for 25 weeks. During Week 52, the incidence and number per rat of gastric cancers were significantly greater in spontaneously hypertensive rats than in Wistar Kyoto and Wistar rats. All tumors induced in the glandular stomach were adenocarcinomas, but no significant difference was found in the histological types of adenocarcinoma in the three strains of rats. At Weeks 15, 30, and 52, norepinephrine concentrations in the fundic and antral portion of the gastric walls and labeling indices in the antral and fundic mucosa were significantly higher in spontaneously hypertensive rats than in Wistar Kyoto and/or Wistar rats. These findings indicate that increased sympathetic nervous system activity enhances the development of gastric cancers, but immunological dysfunction in spontaneously hypertensive rats may contribute to the increased susceptibility to gastric cancer.

Adenocarcinoma↗

PubMed1989

Promotion by neurotensin of gastric carcinogenesis induced by N-methyl-N'-nitro-N-nitrosoguanidine in Wistar rats.

The effects of neurotensin on the incidence and histology of gastric cancers induced by N-methyl-N'-nitro-N-nitrosoguanidine were investigated in Wistar rats. Rats were given 100 or 200 micrograms per kg of body weight of neurotensin s.c. every other day in depot form after 25 wk of p.o. treatment with the carcinogen. Prolonged alternate-day administration of neurotensin at 200 micrograms per kg of body weight resulted in a significant increase in the incidence of gastric cancers of the glandular stomach by Wk 52. However, it did not influence the histological appearance of the gastric cancers. Furthermore, it caused a significant increase in the labeling indices of the epithelial cells of the antrum and of gastric cancers. In contrast, the administration of neurotensin at 100 micrograms per kg of body weight had a slight, but not significant, influence on the development of gastric cancers. These findings indicate that neurotensin promotes gastric carcinogenesis, and that this effect may be related to its effect in increasing proliferation of epithelial cells in the antral mucosa and in gastric cancers.

Animals↗

PubMed1989

Androgen dependency of a tumor produced by a cell line derived from androgen-responsive Shionogi carcinoma 115.

An androgen-dependent tumor (SCC8 tumor) was obtained by inoculating an androgen-responsive cell line derived from the androgen-responsive Shionogi carcinoma 115 (SC115) into mice and then treating the mice with testosterone propionate (TP) at a pharmacological dose (400 micrograms/day). The SCC8 tumor differed in histological appearance from the SC115 tumor and its growth was less stimulated by androgen than that of the SC115 tumor. However, its growth was completely androgen dependent; SCC8 tumors did not develop in castrated mice and regressed when TP treatment was discontinued. The decreased sensitivity of the SCC8 tumor seemed to be attributable in part to its rapid metabolism of testosterone to metabolites with lower androgenic actions. The effects of TP at doses of 0, 100, 200, and 400 micrograms/day on cell division and cell death in SCC8 tumors of medium size were examined by measurements of the mitotic index and the retention of 5-[125I]iodo-2'-deoxyuridine incorporated into the whole tumor. TP increased the mitotic index dose dependently and at all doses reduced the decrease in the retention of 5-[125I]iodo-2'-deoxyuridine. These results suggest that steroids may not only stimulate cell division but also reduce cell death in steroid-dependent tumors.

Androgens↗

PubMed1989

Production of anti-insulin monoclonal antibody and its application to immunoassay of insulin and immunohistochemistry.

An unlimited supply of suitable antisera is wanted for immunoassays, analysis of antigenic determinants and precise localization of antigens in biological systems. Therefore, we produced a monoclonal antiporcine insulin antibody by the hybridoma technology and assessed it in comparison with polyclonal antibody. The spleen cells of BALB/c mice immunized against porcine insulin were hybridized with mouse myeloma cells (P3-X63-Ag8-U1). The monoclonal antibody thus generated was shown to have high binding capacity and specificity to porcine insulin in radioimmunoassay. It reacted with human insulin as well, but did not crossreact with other polypeptide hormones produced in the pancreatic islets such as glucagon, somatostatin and pancreatic polypeptide. In immunohistochemistry human and dog islets were stained by this monoclonal antibody. Rat islets were not stained, although they reacted with polyclonal anti-insulin antibody. The insulin of human serum samples measured using the monoclonal antibody was tightly correlated with that using the polyclonal antibody. These observations indicate that our hybridoma-derived monoclonal antibody is useful for immunoassay as well as localization of insulin.

Animals↗

PubMed1989

Participation of nicotinic receptor in hormone release from isolated rat islets of Langerhans.

Pancreatic hormone release is generally thought to be regulated through adrenergic as well as muscarinic receptors. We have previously observed possible nicotinic involvement in insulin release. In the present study, we incubated isolated rat islets for 60 min with various concentrations of atropine (a muscarinic receptor blocker), alpha-bungarotoxin (alpha-Btx, a nicotinic receptor blocker), and anti-acetylcholine receptor antibody (IgG) (anti-Ach.R.Ab) obtained from a patient with myasthenia gravis. Atropine suppressed insulin release, and alpha-Btx and anti-Ach.R.Ab potentiated it; atropine did not suppress glucagon release, while alpha-Btx and anti-Ach.R.Ab raised it. None of these agents influenced somatostatin release. These observations suggest that muscarinic as well as nicotinic receptors influence insulin release, as nicotinic receptors do glucagon release. Neither nicotinic nor muscarinic receptors seem to regulate somatostatin release.

Acetylcholine↗

PubMed1989

The presence of islet cell antibodies in malnutrition-related diabetes mellitus.

The etiology of malnutrition-related diabetes mellitus (MRDM), mostly seen in the developing countries, is still unknown, though an excessive consumption of cassava and a low intake of protein are considered to be its causative factors. Previous immunological studies, though rarely performed, have so far, to our knowledge, shown no case of MRDM with iselt cell antibodies (ICA). We found a 16-year-old MRDM boy with ICA and report on this in the present communication.

Adolescent↗

PubMed1989

Phosphorylation of hepatic phenobarbital-inducible cytochrome P-450.

The major phenobarbital-inducible cytochrome P-450 purified from rat liver, a member of family II of the cytochrome P-450 gene superfamily, is rapidly phosphorylated by cAMP-dependent protein kinase. The phosphorylation reaches greater than 0.5 mol phosphate/mol P-450 after 5 min and is accompanied by a decrease in enzyme activity. The serine residue in position 128 was shown to be the sole phosphorylation site and a conformational change of the protein was indicated by a shift of the carbon monoxide difference spectrum of the reduced cytochrome from 450 to 420 nm. Comparison of amino acid sequences of various cytochrome P-450 families revealed a highly conserved arginine residue in the immediate vicinity of the phosphorylated serine residue which constitutes the kinase recognition sequence. It also revealed that only the members of the cytochrome P-450 family II carry this kinase recognition sequence. To find out whether this phosphorylation also occurs in vivo, the exchangeable phosphate pool of intact hepatocytes derived from phenobarbital-pretreated rats was labeled with 32Pi followed by an incubation of the cells with the membrane-permeating dibutyryl-cAMP or with the adenylate cyclase stimulator glucagon to activate endogenous kinase. As a result, a microsomal polypeptide with the same electrophoretic mobility as cytochrome P-450 became strongly labeled. Peptide mapping and immunoprecipitation with monospecific antibodies identified this protein as the major phenobarbital-inducible cytochrome P-450. It becomes phosphorylated at the same serine residues as in the cell-free phosphorylation.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

PubMed1989

Multimodal treatment of hepatocellular carcinoma.

Our multimodal treatment of hepatocellular carcinoma (HCC) has brought about a significant improvement of the survival rate. It consists of a combination of hepatectomy and transcatheter arterial embolization using lipiodol (L-TAE). In order to facilitate L-TAE, we have developed a special catheter with notches. A group of patients with HCC (124 cases), excluding cases with absolutely non-curative resections and operative deaths, were treated between December 1980 and November 1986. Each case was treated for more than 1 year after hepatectomy. The patients were divided into two groups: A, patients with a single tumor not larger than 5 cm, and B, cases with larger tumors or more than one lesion. Some patients in each group were treated with L-TAE after hepatectomy. In group A, there was no significant difference in survival between treated and non-treated cases. In group B, L-TAE gave a significantly better survival than no postoperative treatment.

Carcinoma, Hepatocellular↗

PubMed1989

High levels of manganese-containing superoxide dismutase and thermally induced DNA disruption in a dnaK7(Ts) mutant of Escherichia coli K12.

In dnaK7(Ts) mutant cells, scission of DNA strands occurred after temperature shift up. When cells at 30 degrees C were labeled with [3H]-thymidine and then shifted to 46 degrees or 49 degrees C for 20 min, the profiles of sedimentation of their cellular DNA in an alkaline sucrose gradient revealed a decrease in the size of DNA to a quarter of that at 30 degrees C in the mutant, but not in wild-type cells. The level of manganese-containing superoxide dismutase (MnSOD) in the mutant was about twice that in wild-type cells, even at the permissive temperature, implying increased production of superoxide radical anion, which may cleave DNA strands directly or indirectly in the mutant. Moderate increase in the MnSOD level on temperature shift up was observed in both strains. These results indicated that some components of the DnaK protein participate in protection of cellular membrane functions from thermal damage resulting from elevated production of the superoxide anion radical.

Bacterial Proteins↗

PubMed1989

Vacor inhibits insulin release from islets in vitro.

It has been reported that Vacor, a rodenticide containing N-3-pyridylmethyl-N'-p-nitrophenyl urea, causes insulin-dependent diabetes mellitus. The pathomechanism of Vacor-induced diabetes mellitus has not been clarified yet. The effect of Vacor, therefore, was studied in terms of insulin release from isolated rat pancreatic islets. Vacor suppressed glucose-stimulated insulin release, but did not affect the insulin release induced by theophylline or 12-o-tetra-decanoylphorbol 13-acetate. It is suspected that the suppression of insulin release from pancreatic islets by Vacor may contribute to the pathogenesis of Vacor-induced diabetes mellitus and that this suppression might not be related to cAMP and C-kinase.

Animals↗