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Biomedical subjects

T Tobe

Publications and source records attributed to T Tobe.

At least 343 records · Page 19Linked to original sources
PubMed1987

Effect of synthetic neuromedin-N, a novel neurotensin-like peptide, on exocrine pancreatic secretion and splanchnic blood flow in dogs.

Neuromedin-N, a novel neurotensin-like peptide, has recently been identified from porcine spinal cord by using a bioassay for a stimulatory effect on guinea pig ileum. The amino acid sequence of the peptide has been determined to be Lys-Ile-Pro-Tyr-Ile-Leu, which is quite homologous to the COOH-terminal sequence of neurotensin. In this study, the effect of neuromedin-N on pancreas and splanchnic blood flow was investigated in eight dogs. Intravenous injections of graded doses of synthetic neuromedin-N caused a dose-dependent decrease of systemic arterial pressure and a dose-dependent increase in both portal and superior mesenteric arterial blood flow, which were measured with transit time ultrasonic flow meter. Volume and protein output of the pancreatic juice were also increased significantly by Neuromedin-N. Pancreatic capillary blood flow measured with laser Doppler flowmetry was increased in a dose-related manner. The present study first demonstrated that neuromedin-N retains a potent stimulatory effect on the pancreas and splanchnic circulation, indicating that this peptide is one of the biological active forms of neurotensin-like peptide in mammals. This study also leads to the suggestion that this peptide possesses physiological significance as a novel neuropeptide.

Animals↗
PubMed1987

Sequence of an intestinal cDNA encoding human gastric inhibitory polypeptide precursor.

Gastric inhibitory polypeptide (GIP) is a 42-amino acid hormone that stimulates insulin secretion in the presence of glucose. Complementary DNA clones encoding human GIP were isolated from a library prepared with RNA from duodenum. The predicted amino acid sequence indicates that GIP is derived by proteolytic processing of a 153-residue precursor, preproGIP. The GIP moiety is flanked by polypeptide segments of 51 and 60 amino acids at its NH2 and COOH termini, respectively. The former includes a signal peptide of about 21 residues and an NH2-terminal propeptide of 30 amino acids. GIP is released from the precursor by processing at single arginine residues. There is a region of nine amino acids in the COOH-terminal propeptide of the GIP precursor that has partial homology with a portion of chromogranin A as well as pancreastatin.

Amino Acid Sequence↗
PubMed1987

Usefulness of selective arterial secretin injection test for localization of gastrinoma in the Zollinger-Ellison syndrome.

Secretin was injected into a feeding or nonfeeding artery of a gastrinoma and blood samples were taken from the hepatic vein (HV) or a peripheral artery (PA) to measure the changes of serum immunoreactive gastrin concentration (IRG). The IRG in the HV rose within 40 seconds and in the PA rose within 60 seconds after the injection of secretin into a feeding artery, but not after secretin was injected into a nonfeeder. These results indicated that secretin directly stimulates a gastrinoma to release gastrin in vivo. The selective arterial secretin injection test (SASI test) was applied in three patients in whom gastrinomas could not be located by computed tomography, ultrasonography, or arteriography, and functioning gastrinomas were located in all three patients. In one patient, malignant gastrinomas in the head of the pancreas and in the duodenum could be resected radically with the help of this test.

Adult↗
PubMed1987

Plasma cholecystokinin and pancreatic polypeptide response after radical pancreatoduodenectomy with Billroth I and Billroth II type of reconstruction.

This study was conducted to elucidate plasma cholecystokinin (CCK) and pancreatic polypeptide (PP) response after pancreatoduodenectomy and to compare response of CCK and PP in patients who had pancreatoduodenectomy with Billroth I and Billroth II type of reconstruction. Basal levels of plasma CCK were significantly lower in patients who had pancreatoduodenectomy (9.6 +/- 0.8 pmol/L) than in the control (preoperative patients: 14.6 +/- 2.0 pmol/L) probably because of the removal of the entire duodenum due to pancreatoduodenectomy, since vagotomy, which is concomitantly brought about by pancreatoduodenectomy, does not appear to interfere with release of CCK. Significant amounts of CCK (integrated CCK: 497 +/- 111 pmol-120 min/L), although less amounts than in the preoperative patients (integrated CCK: 901 +/- 167 pmol-120 min/L), were still released in response to oral fatty meal after pancreatoduodenectomy. Plasma CCK response to oral fatty meal was significantly greater in patients who had pancreatoduodenectomy with Billroth I type of reconstruction (integrated CCK: 705 +/- 153 pmol-120 min/L) than in patients who had pancreatoduodenectomy with Billroth II type of reconstruction (248 +/- 63 pmol-120 min/L). Simultaneous measurement of plasma levels of PP revealed complete abolishment of PP response by pancreatoduodenectomy. Since PP secretion can be produced by vagal stimulation, it is most likely that the decreased PP secretion is due to vagotomy rather than removal of the duodenum and pancreas. Significant amounts of CCK released after pancreatoduodenectomy, in which the main sources of release of CCK are removed, may suggest the compensatory mechanism of the remnant upper small intestine. This study also suggests the necessity of re-evaluating Billroth I type of anastomosis as a physiologic reconstruction procedure for the remnant alimentary tract after pancreatoduodenectomy.

Adult↗
PubMed1987

Exocrine and endocrine stomach after gastrobulbar preserving pancreatoduodenectomy.

Exocrine and endocrine stomach was studied serially in 13 patients who had gastrobulbar preserving pancreatoduodenectomy (GPPD). In most of them, acid output temporarily increased just after operation but recovered. Gastrin response level decreased transiently but returned to the preoperative level. A negative correlation was observed between the acid and gastrin levels, which suggests that the negative feedback mechanism between parietal cells and G cells was maintained. Acid and gastrin levels in GPPD were higher than those in conventional pancreatoduodenectomy (cPD) but not remarkably different from those of the controls. No peptic ulcer was detected after the operation. These findings indicated that GPPD poses little problem concerning offensive factors. Postoperative ulcer formation is considered to be prevented by the authors' procedure, which is devised to best preserve defensive mechanisms so that duodenectomy is minimized and the gastrointestinal continuity is reconstructed physiologically from mouth to anus by end-to-end duodenoduodenestomy, end-to-side pancreatojejunostomy, and end-to-side choledochojejunostomy.

Adult↗
PubMed1987

Synthetic neuromedin C stimulates exocrine pancreatic secretion in dogs and rats.

We have examined the effect of neuromedin C on exocrine pancreatic secretion both in vivo and in vitro, and compared its bioactivity with those of related peptides. In anesthetized dogs, neuromedin C caused a dose-dependent initial reduction of pancreatic blood flow and an increase in secretin-stimulated exocrine pancreatic secretion, and had almost the same potency as gastrin-releasing peptide (GRP) in decreasing pancreatic blood flow. A potent stimulatory effect on exocrine pancreatic secretion was found in conscious dogs accompanied by a significant elevation in the circulating cholecystokinin (CCK) levels. In isolated rat pancreatic acini, amylase was released dose-dependently in response to neuromedin C. This study demonstrates that neuromedin C (a smaller molecular form of GRP) possesses potent bioactivity on exocrine pancreas and suggests that two factors may be involved in the mechanism by which this peptide effects exocrine secretion, namely; direct stimulation on acinar cells and stimulation of CCK release.

Amino Acid Sequence↗
PubMed1987

High levels of anti-mitochondrial antibodies in MRL mice. Influence of anti-DNA antibodies on anti-mitochondrial antibodies measured by an enzyme-linked immunosorbent assay.

We developed an easy enzyme-linked immunosorbent assay (ELISA) for anti-mitochondrial antibodies, and detected high levels of anti-mitochondrial antibodies in MRL/Mp-lpr/lpr (MRL1/l) mice. The influence of the presence of anti-DNA antibodies in the tested sera on this assay was also evaluated. The monoclonal anti-DNA antibodies, which were made from non-immunized MRL1/l mice, did not react with the mitochondrial antigens adhering to polystyrene plates. Absorption with DNA had little effect on the levels of mitochondrial antibodies in MRL1/l sera. Our assay for mitochondria-binding antibody was very easy and sensitive, although it could not differentiate among heterogeneous anti-mitochondrial antibodies.

Animals↗
PubMed1987

Synthesis of porcine neuropeptide Y(NPY) in solution.

The porcine neuropeptide Y (NPY), a 36-residue peptide amide, was synthesized by assembling six peptide fragments followed by thioanisole-mediated deprotection with trifluoromethanesulfonic acid in trifluoroacetic acid. beta-Cycloheptyl aspartate, Asp(OChp), was employed to suppress base-catalyzed succinimide formation. When administered to dogs, the purified peptide (10 micrograms/kg) caused prolonged increase of systemic arterial blood pressure and decreased pancreatic blood flow.

Animals↗
PubMed1987

Suppression of rpoH (htpR) mutations of Escherichia coli: heat shock response in suhA revertants.

Temperature-resistant pseudorevertants were isolated from rpoH (htpR) mutants of Escherichia coli K-12 that cannot grow at a high temperature owing to a deficiency in sigma 32 required for the induction of heat shock proteins. Among them was a class of revertants carrying a suppressor mutation, designated suhA, that suppressed all the nonsense and missense rpoH mutations tested. suhA is located at 77 min, about 1 min away from rpoH, on the genetic map. In contrast to the rpoH mutants, the suhA revertants that contained both rpoH (nonsense) and suhA mutations were fully or partially proficient in the induction of heat shock proteins upon exposure to a high temperature. Under these conditions, transcription from two heat shock promoters as determined by operon fusion was transiently activated. In one of the rpoH(Am) suhA revertants studied in detail, an increase in temperature caused the synthesis of significant amounts of sigma 32, accompanied by increased stability and accumulation of rpoH mRNAs. On the other hand, the same mutation (suhA6) only weakly suppressed the rpoH deletion mutant; however, two of the major heat shock genes, dnaK and groE, were apparently induced in the absence of sigma 32. Thus, suhA6 seems to bring about the induction of heat shock genes by at least two mechanisms, one increasing the level of sigma 32 synthesis, and the other activating some transcription factor other than sigma 32.

Chromosome Mapping↗
PubMed1987

[An immunohistochemical study on esophageal carcinomas with various kinds of antikeratin antibodies].

Fifty five formalin-fixed, paraffin-embedded, pronase-pretreated esophageal carcinomas and their metastatic nodes were studied immunohistochemically with peroxidase-antiperoxidase technique for keratins using polyclonal antibody (DAKO), antibody against keratins of keratinocyte (KL1), against high molecular weight-keratin (EY904), and against low molecular weight-keratins (EY902, PKK1). The suprabasal layer of the esophageal epithelium was stained diffusely with DAKO, KL1 and EY902 and faintly or locally with EY904 and PKK1. Esophageal ducts were positive with any antibodies. We classified staining pattern of the esophageal carcinoma according to the localization and proportion of the positive cells in the cancer nests. No significant correlation of the staining pattern was found between the primary lesions and metastatic nodes. The proportion of the EY904-positive cells correlated significantly with the degree of lymph node metastasis, histologic stage, and prognosis by rank correlation method and generalized Wilcoxon test, but not with the depth of invasion nor histologic degree of differentiation. The proportion of DAKO-positive cells correlated significantly only with histologic degree of differentiation. It was supposed that esophageal carcinomas with high molecular weight-keratin had less tendency to metastasize to nodes.

Antibodies↗
PubMed1987

[Breast cancer-specific immunity evaluated by a new in vitro method--IL-2 enhanced MLTR].

Peripheral blood lymphocytes from 81 patients with breast cancer were stimulated in vitro with solubilized sonicated autologous tumor extract as an antigen source . The significance of tumor-stimulation (mixed lymphocyte tumor reaction; MLTR) was evaluated with or without the addition of interleukin-2 (IL-2,90 U/ml). As a result, MLTR with the addition of IL-2 (IL-2 enhanced MLTR) showed a higher significance even at a stimulation index (S.I.) of 1.5 than MLTR without IL-2. The values of S. I. in IL-2 enhanced MLTR in preoperative cancer patients were the highest in the patients without lymph node metastasis (n0). The patients with advanced lymph node metastasis (n2) showed a lower response preoperatively but their response was similar to that of the n0-patients 1 to 2 was after operation. These difference were not observed in the blastogenic response to IL-2. These results suggest that IL-2 enhanced MLTR is a useful method to assess the tumor-specific immunological status of the cancer patients.

Antigen-Antibody Reactions↗
PubMed1987

Retrosternal esophagogastrostomy with the EEA stapler.

We performed an anastomosis of the cervical esophagus to the retrosternally shifted gastric tube with a new technique. The technique was applied successively to ten patients undergoing distal subtotal esophagectomy for carcinoma of the esophagus. In every patient, the technique was done easily and anastomoses were completed without any leakage, bleeding or stricture.

Carcinoma↗