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Biomedical subjects

Y Kuyama

Publications and source records attributed to Y Kuyama.

At least 37 records · Page 2Linked to original sources

Intestinal Behçet's disease associated with non-Hodgkin's lymphoma.

A 45-year-old man with intestinal Behçet's disease noticed an enlarged right cervical lymph node, and was diagnosed with diffuse large cell type, non-Hodgkin's lymphoma. The intrapelvic lymph tract was markedly deformed because of recurrent ileocecal ulceration, and conventional lymphoscintigraphy with a common tracer did not abolish the suspicion that lymphoma cells may have invaded the lymph nodes. Dynamic lymphoscintigraphy with a new tracer, 99mtechnetium-diethylene triamine pentaacetic acid-human serum albumin, because of its high detection sensitivity, was very useful for excluding this suspicion, and for determining the clinical stage of lymphoma. Combination induction chemotherapy led to complete remission without any adverse effects, but subsequent supportive therapy with same protocol could not be completed because of progression of the intestinal lesions. Special management for the intestinal lesions, such as bowel rest, may be essential with chemotherapy for patients with intestinal Behçet's disease.

Antineoplastic Combined Chemotherapy Protocols↗

Absorption of unconjugated bile acids and tauroursodeoxycholate in the rat intestine.

The absorption of ursodeoxycholate and its tauro-conjugate by the jejunum and the terminal ileum of rat intestine was compared with that of other unconjugated bile acids and taurocholate. In the ligated jejunum, the efficacy of absorption of unconjugated bile acids was in the following order: ursodeoxycholate = deoxycholate > chenodeoxycholate = cholate > lithocholate. This order cannot be explained by the theory that the passive diffusion of bile acids is faster the less hydroxyl bonds in the molecule. These findings on the unconjugated bile acids in the ligated jejunum were further confirmed by perfusion experiments. In the ligated terminal ileum, ursodeoxycholate, cholate and deoxycholate were absorbed as fast as taurocholate or tauroursodeoxycholate, whereas absorption of chenodeoxycholate was significantly slower. The Na+-dependency of the absorption of ursodeoxycholate and cholate in the terminal ileum was confirmed by perfusion studies. In conclusion, intestinal absorption of ursodeoxycholate was efficient in both the jejunum and ileum and these results may contribute to the high availability of ursodeoxycholate in various hepatobiliary diseases.

Animals↗

Gastrointestinal stromal tumor of the stomach.

We report a case of gastrointestinal stromal tumor (GIST) of the stomach. The patient was a 79-year-old woman with two gastric submucosal tumors detected by ultrasonography. Proximal gastrectomy was carried out and the tumors were diagnosed as GIST by histological and immunohistochemical investigations. Mesenchymal tumors of the gastrointestinal tract have been traditionally regarded as largely leiomyomatous lesions. However, GIST and other tumors have been distinguished recently on the basis of tumor cell differentiation shown by immunohistochemical studies. We discuss the concept and the immunohistochemical characteristics of GIST.

Actins↗

A reliable and convenient parameter of the rate of paracetamol absorption to measure gastric emptying rate of liquids.

The rate of paracetamol absorption represents gastric emptying rate (GER) of liquids. Thus, the liquid GER is assessed by conventional pharmacokinetic parameters such as the maximum concentration and the time to maximum concentration after oral administration of paracetamol. However, the conventional parameters are subject not only to the rate but also to the extent of absorption. For the reliable assessment of GER we have proposed a new parameter, the C0.5/C0.25 ratio, for the rate of paracetamol absorption without being affected by the extent of absorption. Of 15 healthy male volunteers, 9 orally received 10 mg/kg of paracetamol with 200 ml of water as the "normal" GER group, and the other 6 took 10 mg/kg of paracetamol with 200 ml of a liquid nutrient (200 kcal/200 ml), which delays GER, as the "delayed" GER group. Blood samples were obtained at t = 0 (pre-dose), 0.25, 0.5, 0.75, 1.0, 1.5, 2.0, 3.0, 4.0, 6.0, and 8.0 hours (post-dose). In each subject, GER was assessed by the conventional parameters, the C0.5/C0.25 ratio, and the Wagner-Nelson method which provides an accurate estimate of the drug absorption rate. Using the C0.5/C0.25 ratio and the Wagner-Nelson method we could more clearly differentiate the delayed GER group from the normal GER group than by using the conventional parameters. This suggests that the C0.5/C0.25 ratio and the Wagner-Nelson method may be more reliable than the conventional parameters in detecting a delay in GER. Further, it should be noted that the C0.5/C0.25 ratio can be calculated from only 2 blood samples while the Wagner-Nelson method requires repeated blood sampling.

Acetaminophen↗

Luminal bile regulates cholecystokinin release in conscious rats.

The effects of intraluminal bile on cholecystokinin release and pancreatic exocrine secretion were studied in conscious rats. Since it has been suggested that bile acid may influence pancreatic secretion indirectly by interacting with luminal protease activities, intraduodenal protease activities were eliminated by pancreatic juice diversion accompanied with simultaneous intraduodenal infusion of aprotinin. This treatment resulted in gradual increases in pancreatic juice flow, bicarbonate and protein outputs, and an increase in plasma cholecystokinin levels, reaching plateau levels 2 hr after the start of the treatment. When endogenous bile was excluded from the intestine, the pancreatic secretion and plasma cholecystokinin concentrations further increased. The intraduodenal infusion of sodium taurocholate during bile pancreatic juice diversion inhibited cholecystokinin release, while pancreatic protein output was only transiently decreased. The results indicate that bile in the duodenum directly regulates cholecystokinin release, probably through its major components, bile salts.

Animals↗

[Basal plasma cholecystokinin levels in digestive diseases--comparison between CCK-8 like bioactivity by bioassay and CCK immunoreactivity by radioimmunoassay].

Basal plasma cholecystokinin levels were measured by a bioassay using dispersed rat pancreatic acini in various digestive diseases and compared with corresponding values by CCK-8 specific radioimmunoassay. The mean basal level in healthy volunteers was 0.40 +/- 0.06 pM. The basal level in liver cirrhosis was significantly elevated to 0.92 +/- 0.14 pM. The patients with cholestasis, that is, primary biliary cirrhosis and obstructive jaundice due to choledocholithiasis, bile duct cancer or lymph node metastasis , had markedly increased basal plasma CCK-8 like bioactivities from 1.88 pM to more than 25 pM. These CCK bioactivities were not correlative with CCK immunoreactivities. It was concluded not only that basal plasma CCK in patients with bile flow disturbance were truly increased, but also that interfering substances of the bioassay might appear in the plasma of these patients.

Adult↗