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Biomedical subjects

H C Tseng

Publications and source records attributed to H C Tseng.

At least 37 records · Page 2Linked to original sources

Insulinoma. An immunocytochemical and morphologic analysis of 95 cases.

One hundred twenty-seven insulinomas from 95 cases (1 malignant and 94 benign) were studied pathologically. Thirty-six tumors (35 cases) were examined by electron microscopy. Typical beta-cell secretory granules of crystalloid-form cores and/or atypical secretory granules were discerned in all tumors examined. A new type of secretory granule, with high electron-dense crystalloid-form cores and moderate electron-dense granular substance filling the space between the core and the limiting membrane, were observed in two cases. Among 68 insulinomas (67 cases) subjected to immunocytochemical investigations with ten peptide hormones (insulin, glucagon, somatostatin, pancreatic polypeptide (PP), gastrin, motilin, secretin, vasoactive intestinal polypeptide (VIP), gastric inhibitory polypeptide (GIP), and neurotensin), 42 were found to be multihormonal, varying from two to four peptides secreted. The hormones contained were insulin, glucagon, PP, somatostatin, and gastrin in different combinations. One patient had hyperinsulinemia and hypergastrinemia concurrently, and two islet tumors were excised at an interval of 10 months. Both electron microscopy and immunocytochemistry confirmed the presence of beta- and alpha-cells in the first tumor, whereas the second tumor revealed only G-cells by electron microscopy, and G- and beta-cells on immunocytochemical staining. The morphologic and immunocytochemical characteristics of the insulinomas in this series are discussed.

Adenoma, Islet Cell↗

Regulation of digestion. I. Effects of glucose and lysine on pancreatic secretion.

Previous cell-free studies have shown that glucose selectively elicits the release of amylase from pancreatic zymogen granules, whereas lysine promotes the selective release of trypsinogen. To investigate the expression of these effects in situ, glucose or lysine was injected into the celiac artery of anesthetized rats, either alone or together with the pancreatic secretagogue cholecystokinin, to evaluate their effects on the secretion of amylase and trypsinogen by the pancreas. When given alone neither substance significantly changed the output of either enzyme. However, when given with cholecystokinin, each altered the effect observed with injection of cholecystokinin alone. The injection of glucose resulted in a twofold increase in both peak and total amylase output without significantly increasing trypsinogen secretion, whereas lysine increased both peak and total trypsinogen output by about 50%, leaving amylase output unchanged. These findings provide in situ confirmation for the selective enzyme release produced by glucose and lysine in cell-free studies and suggest that such end products of digestion can regulate the digestive process by modifying the secretory response of the pancreas to cholecystokinin.

Animals↗

Regulation of digestion. II. Effects of insulin and glucagon on pancreatic secretion.

The endocrine islet-cell hormones insulin and glucagon are secreted at high concentrations into an intrapancreatic portal circulation and have been reported to affect the secretion of digestive enzyme by the exocrine pancreas. In the present experiments, insulin and glucagon were injected into the celiac artery of anesthetized rats to evaluate their effects on the secretion of amylase and trypsinogen by the pancreas. Neither hormone when given alone significantly changed the output of either enzyme. However, when given with the pancreatic secretagogue cholecystokinin, each altered the effect of injection of cholecystokinin. In a dose-dependent fashion insulin increased trypsinogen output without affecting amylase output, whereas glucagon inhibited amylase output and left trypsinogen output unchanged. Thus, both hormones produced a more trypsinogen-dominant pancreatic juice than that observed with cholecystokinin alone, although in different ways. These findings suggest that the endocrine hormones insulin and glucagon may regulate secretion of digestive enzymes by the pancreas by modulating the response to stimuli of overall protein secretion such as cholecystokinin.

Animals↗

Current surgical interests in China.

Until recently, China had been isolated from Western countries for almost 30 years. Surgeons of Western countries, perhaps, are interested to know what is happening in surgery in China. This communication reviews the current interests in Chinese surgery. It is by no means complete, nor is that the intention. The intention is to introduce to our foreign colleagues a general overview of some highlights in Chinese surgery.

Bone and Bones↗

Food, duodenal extracts, and enzyme secretion by the pancreas.

Previous studies have reported that injection of duodenal extracts from rats fed different meals into the celiac artery of recipient rats elicited the secretion of related pancreatic enzymes. We have been unable to reproduce the enzyme-specific increases in the average output of particular enzymes that were observed but did find changes similar in direction, although not magnitude, to those reported previously. The outputs of amylase and trypsinogen were compared by plotting individual data points and performing a regression analysis on them. The injection of duodenal extracts from lactalbumin hydrolysate-fed rats led to trypsinogen secretion being favored over that of amylase and vice versa for extracts from rats fed a glucose meal. In addition, it was found that cholecystokinin-pancreozymin produced a dramatic nonparallel transport of these two enzymes with amylase secretion being augmented to a greater degree than trypsinogen secretion. The relation between their outputs was curvilinear, i.e., the amylase dominance of secretion became more pronounced as overall enzyme output (not dose of hormone) increased. Thus, this nonparallel secretion does not seem to be the results of a discontinuous switch in the character of enzyme secretion produced by the hormone but a graded effect reflecting the magnitude of the response.

Amylases↗

Salmonellae in Tan-Shui River (author's transl).

A total of 61 water samples collected from 10 stations along the Chilung River, Hsintien Chi, Ta-han River were examined for salmonellae from Sep. 1978 to July 1979. There were 227 Salmonella strains isolated. After biochemical test and serological identification, 31 serotypes were verified. They were classified into 12 groups: B, C1, C2, C3, D1, E1, E2, E4, F, G2, H and R. S. derby was isolated in the highest rate (27.75%) and was followed by S. kuru (11.89%), S. worthington (7.93%), S. cambridge (5.73%), S. panama (4.41%). Twenty-three serotypes were firstly recovered from Taiwan area.

Salmonella↗

Insulinoma. Experience in surgical treatment.

Sixty cases of insulinoma were treated surgically. The possible causes for failure to find the tumor during exploratory surgery are discussed. Simple enucleation is preferred in most cases of single or a few insulinomas. A technique of enucleation with minimal chance of injury to adjacent pancreatic ducts and larger blood vessels can be used. When no tumor is found after thorough exploratory procedures, controlled staged resection of the pancreas under blood glucose monitoring is the procedure of choice. Postoperative complications are common but the late results are gratifying provided the operation is carried out early in the course of the disease.

Adenoma, Islet Cell↗