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Biomedical subjects

T Tobe

Publications and source records attributed to T Tobe.

At least 307 records · Page 17Linked to original sources

Effect of synthetic human cholecystokinin-33 on exocrine pancreas.

Synthetic human cholecystokinin-33 was first evaluated with respect to the biological activity on the pancreatic protein secretion. Human cholecystokinin-33 increased pancreatic protein secretion in a dose-related manner. The relative molar potency of this substance compared to that of synthetic cholecystokinin-8 (taken as 1.0) was 0.92. This study supports the concept that longer molecular forms of cholecystokinin are quantitatively important mediators of biological action of cholecystokinin on the pancreas.

Animals↗

Effect of natural peptide YY on blood flow and exocrine secretion of pancreas in dogs.

Little is known regarding the mechanism by which peptide YY exerts an inhibitory effect on exocrine pancreatic secretion. The purpose of this study is to determine if peptide YY affects pancreatic blood flow with simultaneous measurement of exocrine pancreatic secretion in dogs. Pancreatic blood flow was measured by a laser Doppler flowmeter which allows continuous measurement of tissue blood flow. Natural peptide YY (0.1, 0.5, 1 microgram/kg) was infused intravenously as a bolus under background infusion of secretin (1 unit/kg/hr) in combination with cholecystokinin-octapeptide (0.1 microgram/kg/hr). Peptide YY caused a reduction of pancreatic blood flow in a dose-dependent manner as well as inhibition of pancreatic protein output, attaining the maximal reduction (28 +/- 4%) and inhibition (45 +/- 9%) at a dose of 1 microgram/kg, respectively. Simultaneous and continuous observation on tissue blood flow and exocrine secretion of the pancreas revealed that there was a highly significant correlation between the percent reduction of pancreatic blood flow and that of volume of pancreatic juice in response to peptide YY (r = 0.849, P less than 0.001). This study provides evidence that the mechanism of peptide YY-induced inhibition of exocrine pancreatic secretion is mediated, at least partly, through the decreased pancreatic blood flow.

Animals↗

Comparative studies on immunoglobulins, complement component (C3), albumin, and immunoglobulin A-containing circulating immune complexes in serum and bile of patients with biliary obstruction.

We measured the concentrations of IgA, IgG, IgM, secretory IgA, albumin, complement component (C3), and IgA-containing circulating immune complex (IgA-CIC) in the serum and bile of patients with biliary obstruction. The bile-to-serum (BS) ratio of the concentrations of albumin and IgG increased with the increase in total serum bilirubin. This indicates that the permeability from blood to bile increases with the degree of biliary obstruction, and the blood-bile barrier function breaks down. The BS ratios of IgA and IgM, which are selectively secreted into bile, did not show a significant correlation with total serum bilirubin. The index of the BS ratio to the BS ratio of albumin (BS/BS-Alb index) of IgA and IgM was significantly larger than that of IgG. This indicates that the selective transport of IgA and IgM into bile is present even in patients with obstructive jaundice. Since the BS/BS-Alb index of C3 is larger than that of IgG, and the SGOT correlated directly with the BS ratio of C3, some of the C3 in bile may come from damaged hepatocytes.

Albumins↗

Effects of intravenous ethanol on hepatic and pancreatic blood flow in dogs.

Changes in hepatic and pancreatic blood flow in response to ethanol infusion were determined simultaneously and continuously in anesthetized dogs, using a transit-time ultrasonic flowmeter and a laser-Doppler flowmeter. In addition, the effect of intravenous ethanol on exocrine pancreatic secretion was investigated. With a background infusion of secretin, ethanol (1.3 g/kg body wt) was infused intravenously over a 40-min period. Ethanol infusion significantly increased blood flow in the common hepatic artery (by 49%, at the time of the cessation of ethanol infusion), and this increased flow was maintained for 60 min after the cessation of ethanol infusion. In contrast, blood flow in the portal vein was not altered significantly by ethanol. Pancreatic blood flow and secretion showed no significant difference from those seen in the controls. Our data suggest that intravenous ethanol induces a redistribution of the splanchnic blood flow. The increased hepatic arterial flow seen in response to ethanol may play an important role in preventing ethanol-induced hypoxic liver damage.

Animals↗

The three different phases of reticuloendothelial system phagocytic function in rats with liver injury.

In the present study, reticuloendothelial system (RES) phagocytic function of rats with partial hepatectomy or experimentally induced liver cirrhosis was investigated by determining the phagocytic index, the opsonic index, and uptake rate in liver, spleen, and lung of a 51Cr-labeled endotoxin-injected rat. In both the partially hepatectomized and the cirrhotic rats, all three indicators varied markedly according to the elapsed period since liver injury. The changes in RES phagocytic function were classified into three different phases: compromised, compensatory, and enhanced. The compromised phase, consisting of a decrease in the phagocytic index, was observed during the first 24 hr after 67% hepatectomy and in advanced liver cirrhosis. This represented the failure of RES phagocytic function. The compensatory phase, in which the phagocytic index was maintained at nearly normal levels mainly by a compensatory enhancement in the opsonic index, was seen during the first to second postoperative day and in moderate liver cirrhosis. The enhanced phase, with a high phagocytic index, was observed from Day 4 to approximately Day 14 after surgery, and in the cases of mild liver damage. In the compromised and compensatory phases, the liver uptake rate was significantly decreased compared with the control. However, the uptake in the spleen and lung were markedly increased. In conclusion, the phagocytic function of the RES was significantly affected to a degree which changed with the extent of liver damage.

Animals↗

Japan gastric trials in intraoperative radiation therapy.

Based upon our clinical results indications of intraoperative radiotherapy (IORT) for gastric cancer were summarized as follows: (a) The primary tumor must be surgically removed. (b) There must be no metastases to the liver or peritoneum. (c) Serosal invasion must be limited to the posterior wall of the stomach. IORT is not adaptable to patients in whom there is direct invasion of the peritoneum beyond the anterior wall because of the ease of peritoneal dissemination. (d) All unresectable lesions must be encompassed by a single radiation field. (e) No significant difference between cumulative survival of patients with Stage I gastric cancer who were treated by IORT or surgery alone was found. Therefore IORT may be of no benefit to the prognosis of patients with Stage I gastric cancer. As for the IORT dose, it is recommended that for clinically undetectable lesions a single dose of 28 Gy be delivered. For macroscopic remnants 30-35 Gy should be delivered depending upon the residual tumor size. The electron energy is selected so that the entire lesion is included by the 90% isodose line. When IORT is applied to a curative operation, the radiation field is positioned toward the lymph node groups around the celiac axis, which are hard to eliminate by a surgical procedure.

Combined Modality Therapy↗

Circulating immune complex, endotoxin, and biliary infection in patients with biliary obstruction.

Immunoglobulin A-containing circulating immune complexes, immunoglobulin G-containing circulating immune complexes, and endotoxin were measured in the sera of patients with obstructive jaundice. The bile of patients with percutaneous transhepatic biliary drainage was also cultured for bacteriologic studies. There was a significantly positive correlation between the endotoxin levels and both immunoglobulin A-containing circulating immune complex and immunoglobulin G-containing circulating immune complex. The endotoxin levels of the patients with gram-negative infections were significantly increased compared with those of the patients with sterile cultures. The immunoglobulin G-containing circulating immune complex levels of the patients with bacteria in bile were significantly increased compared with those of the patients with sterile cultures. The immunoglobulin A-containing circulating immune complex levels of the patients with bacteria in bile were slightly increased, but the difference did not reach statistical significance. These results indicate that one of the causes of increased circulating immune complex levels may be endotoxemia in combination with biliary infection in patients with biliary obstruction.

Antigen-Antibody Complex↗

Effects of synthetic human gastric inhibitory polypeptide on splanchnic circulation in dogs.

Changes in blood flow in the celiac artery, superior mesenteric artery, and pancreas in response to an intravenous injection of synthetic human gastric inhibitory polypeptide (GIP) were determined simultaneously and continuously in anesthetized dogs, using a transit-time ultrasonic flowmeter and a laser-Doppler flowmeter. Injection of GIP significantly increased superior mesenteric arterial flow in a dose-related manner (by 9%, 43%, and 139% at 30 s after an injection at the doses of 3, 50, and 800 pmol/kg, respectively). In contrast, celiac arterial flow was not significantly altered by GIP at any of the three doses. Calculated vascular resistance in the superior mesenteric artery decreased after GIP infusion, whereas that in the celiac artery was not changed by GIP. Pancreatic blood flow decreased significantly after GIP injection at the doses of 50 and 800 pmol/kg (by 11% and 17%, respectively). Our data indicate that there is a substantial difference in the hemodynamic responses to GIP among splanchnic organs, and suggest that GIP acts specifically on the mesenteric vasculature.

Animals↗

Transthoracic resection of esophageal cancer in patients with pulmonary dysfunction. Usefulness of high frequency ventilation during thoracotomy.

Although curative resection of esophageal cancer has become a safe procedure, in patients with pulmonary dysfunction, postoperative complications remain a serious problem. Of 122 patients who had transthoracic resection of esophageal cancer, 27 had pulmonary dysfunction; in six, the forced vital capacity was less than 70% (minimum of 42.8%, mean +/- SD of 56.6 +/- 8.9%); in 18, forced expiratory volume for one second (FEV1%) was less than 70% (minimum of 34.6%, mean +/- SD of 60 +/- 10%); and in three, both forced vital capacity and forced expiratory volume was less than 70%. Two patients had undergone hemipneumonectomy before receiving resection of the esophagus. During the intrathoracic operative procedure, high frequency ventilation was used, providing good surgical exposure and contributing to a decrease of postoperative pulmonary complications. There were no deaths during the month after surgery. The survival curve of these patients was not significantly different from that of other patients who had had esophagectomy for cancer of the esophagus. These patients survived for an average of 24 months. The patient who survived the longest has been alive for more than 11 years.

Aged↗

The effect of splenectomy on antibody response to lipopolysaccharide (E. coli) immunization.

The influence of splenectomy on the antibody response to lipopolysaccharide (LPS: E. coli 0128:B12) was investigated in mice. Splenectomy had little effect on the primary response to the LPS. However, the level of IgG anti-LPS antibodies of splenectomized mice was significantly lower than that of sham-operated mice when the mice were immunized 1, 3, and 7 days after the operation and reimmunized 7 days after the first immunization. There was no significant difference in those immunized 30 days after the operation and reimmunized 7 days later. In mice immunized before splenectomy and reimmunized 30 days after splenectomy, the level of IgG anti-LPS antibodies was low, even in the mice splenectomized 30 days after primary immunization. Our results indicate that splenectomy impairs the antibody response to lipopolysaccharides.

Animals↗

Effects of sera from patients with obstructive jaundice on the generation of oxygen intermediates by normal polymorphonuclear leukocytes.

Recently it has been suggested that oxygen intermediates play an important role in the pathogenesis of tissue damage. The effect of sera from patients with obstructive jaundice on the generation of oxygen intermediates by normal polymorphonuclear leukocytes (PMNs) was investigated. Sera from patients with obstructive jaundice increased superoxide anion (O2-), hydrogen peroxide (H2O2) and hydroxol radical (OH.) generation compared with sera from healthy individuals or patients with biliary tract stones and/or tumors of the biliary tract or pancreas (without obstructive jaundice). In particular, the hydroxyl radical, which is one of the most potent oxidants capable of causing tissue damage, was produced in large quantities. Sera from patients with obstructive jaundice have a strong capacity to induce production of oxygen intermediates from PMNs, and oxygen intermediates may play a role in the pathogenesis of hepatic and other organ injury in obstructive jaundice.

Cholestasis↗