Yoshiaki Haba

Stromal tumor of the pancreas with expression of c-kit protein: Report of a case

Abstract We report on a case of a stromal tumor, similar to a gastrointestinal stromal tumor, originating from the pancreas. The patient was a 54‐year‐old woman, who was seen at the Kofu Municipal Hospital because of an abdominal tumor. On abdominal computed tomography and splenic arteriography, the tumor was detected in the pancreatic tail. The patient underwent distal pancreatectomy with splenectomy. Macroscopically, the cut surface of the tumor showed almost completely surrounded by the normal pancreatic tissue. Microscopically, the tumor composed of spindle‐shaped cells that were immunoreactive for vimentin, CD34, and c‐kit protein. Therefore, the tumor was diagnosed as a stromal tumor of the pancreas. The expression of c‐kit protein suggests that this pancreatic stromal tumor may originate from primitive mesenchymal cells which can be a logical candidate for the origin of gastrointestinal stromal tumors and extra‐gastrointestinal stromal tumors.

Gas-forming liver abscess after transcatheter arterial embolization for hepatocellular carcinoma: Report of a case

A case of a gas-forming liver abscess developing after transcatheter arterial embolization for recurrent hepatocellular carcinoma (HCC) in a 65-year-old man is presented herein. He was admitted to hospital with fever and jaundice, following which ultrasonography (US) and computed tomography revealed a gas-containing abscess in the posterior segment of the hepatic lobe with multiple HCC. Percutaneous transhepatic drainage was performed using US. Antibiotics which were sensitive to theEscherichia coli bacteria detected in the abscess were administered both intravenously and through the drainage tube into the abscess. Four months later, the abscess had diminished and the patient was discharged after receiving percutaneous ultrasonographically guided ethanol injection therapy for the recurrent HCC.

Stratifying the risk of lymph node metastasis in undifferentiated-type early gastric cancer

AIM To study how lymph node metastasis (LNM) risk is stratified in undifferentiated-type early gastric cancer (undiff-EGC) dependent on combinations of risk factors. METHODS Five hundred and sixty-seven cases with undiff-EGC undergoing gastrectomy with lymphadenectomy were examined retrospectively. Using clinicopathological factors of patient age, location, size, an endoscopic macroscopic tumor form, ulceration, depth, histology, lymphatic involvement (LI) and venous involvement (VI), LNM risk was examined and stratified by conventional statistical analysis and data-mining analysis. RESULTS LNM was positive in 44 of 567 cases (7.8%). Univariate analysis revealed > 2 cm, protrusion, submucosal (sm), mixed type, LI and VI as significant prognostic factors and > 2 cm and LI-positive were independent factors by multivariate analysis. In preoperatively evaluable factors excluding LVI, sm and > 2 cm were independent factors. According to the depth and size, cases were categorized into the low-risk group [m and ≤ 2 cm, 0% (LNM incidence)], the moderate-risk group (m and > 2 cm, 5.6%; and sm and ≤ 2 cm, 6.0%), and the high-risk group (sm and > 2 cm, 19.3%). On the other hand, LNM occurred in 1.4% in all LI-negative cases, greatly lower than 28.2% in all LI-positive cases, and LNM incidence was low in LI-negative cases even in the moderate- and high-risk groups. CONCLUSION LNM-related factors in undiff-EGC were depth and size preoperatively while those were LI and size postoperatively. Among these factors, LI was the most significantly correlated factor.

The effect of a thromboxane A2 receptor antagonist (ONO 3708) on ischemia-reperfusion injury of the dog pancreas

The effects of a thromboxane A2 receptor antagonist, ONO 3708, on ischemia-reperfusion injury of the pancreas were evaluated using an isolated in-vivo-perfused dog pancreas model. Pancreatic endocrine and exocrine function were stimulated with cholecystokinin octapeptide (10(-12) mol). This dose significantly increased endogenous prostaglandin I2 and thromboxane A2 production by the pancreas (both P < 0.001). A period of 60 min of ischemia and subsequent reperfusion induced an increase of pancreatic amylase release (P < 0.01) and a decrease of insulin release (P < 0.01). There was also a decrease of pancreatic juice and pancreatic bicarbonate and amylase output (au P < 0.01), suggesting damage to the acinar, ductular, and beta cells. Intravenous administration of ONO 3708 (200 micrograms/kg/min) throughout the experiment prevented these abnormalities of pancreatic secretion. It also reduced the plasma lipid peroxide level in the venous drainage (P < 0.01) and elevated the prostaglandin I2 level (P < 0.01) without changing thromboxane A2 levels. ONO 3708 thus appeared to protect the pancreas from ischemia-reperfusion injury by reducing the peroxidation of cell membrane lipids and by decreasing the thromboxane A2/prostaglandin I2 ratio, which is a predictor of cellular injury.

Effects of parathyroid hormone on pancreatic exocrine secretion.

The role of parathyroid hormone (PTH) and calcium on pancreatic exocrine secretion were observed using sham-operated and parathyroidectomized dogs. First, exocrine secretion of the pancreas stimulated with secretin and cholecystokinin octapeptide (CCK-8) was examined in vivo 3 weeks after parathyroidectomy. Secondly, perfusion experiments of isolated pancreas in the sham-operated and parathyroidectomized dogs were examined. In one experiment, volume of pancreatic juice and bicarbonate output, but not amylase output, was decreased in the parathyroidectornized dogs compared with those in the sham-operated dogs; no participation of calcium in exocrine secretion was revealed. In another experiment, high doses of PTH evoked increases of pancreatic juice and bicarbonate output without changing amylase output; as before, no participation of calcium in the exocrine secretion was observed. We conclude that (a) FTH increases volume of pancreatic juice and bicarbonate output, and (b) pancreatic exocrine secretion is modified by direct effect of PTH, and the pancreatic ductular cells, not the acinar cells, are the target for PTH.

Mediastinal Mature Teratoma With Rupture Into Pleural Cavity Due to Blunt Trauma

We report a rare case of mediastinal mature teratoma with rupture due to blunt trauma. A 15-year-old boy had received a strong head-butt in the left upper chest wall and was admitted with the sudden onset of left-sided severe chest pain and dyspnea. Chest computed tomography (CT) scan on admission revealed a heterogeneous mass lesion in the anterior mediastinum. The contrast-enhanced CT scans obtained 2 days after admission showed not only mediastinal mass lesion but also left pleural effusion. On the radiologic finding at 5 months later, the lesion became larger and was thought to be a typical mediastinal mature teratoma. The patient underwent extirpation of the tumor. Microscopically, the tumor was typically composed of adult-type tissues and was confirmed to be mature teratoma.

Metabolism of insulin and glucagon in liver and pancreas in dogs with obstructive jaundice.

Insulin and glucagon metabolism in the pancreas with obstructive jaundice caused by complete ligation of the common bile duct and in the cholestatic liver caused by hepatic duct ligation was evaluated experimentally using dogs. The isolated perfused pancreas in obstructive jaundiced dogs, which showed a low insulin response in the peripheral blood after intravenous glucose administration, revealed depression of insulin production and no change of glucagon production in response to cholecystokinin octapeptide. The extraction of insulin in the cholestatic lobe of the liver was decreased compared with that in the noncholestatic lobe. The extraction of glucagon, on the other hand, in the cholestatic lobe and in the noncholestatic lobe showed no significant difference. So the imbalance of glucose metabolism in obstructive jaundice does not depend on the enhanced extraction of insulin in the liver, but on the depression of insulin production in the pancreas.

Prostaglandin E1 protects dog pancreas from ischemia-reperfusion injury

Effects of prostaglandin (PG) El on ischemia-reperfusion (I-R) injury to the pancreas was evaluated using isolated in vivo perfused dog pancreas. Pancreatic endocrine and exocrine functions were stimulated with 10−12 M cholecystokinin octapeptide (CCK-8). This amount of CCK-8 promoted production of insulin, glucagon, PGI2, and thromboxane (Tx) A2 in the pancreas. Sixty minutes of ischemia and subsequent reperfusion induced damage to pancreatic ductular, acinar, and β cells. Intra-arterial administration of PGE, at a dose of 0.5 pg/kg/min throughout the experiment prevented the I-R injury, reducing plasma lipid peroxides, and elevating PGI, without changing TxA2 in the pancreas. PGE2 thus appears to protect pancreatic function from I-R injury both by depressing the effect of free-radicals and by decreasing TxA2PGI2which predicts cell injury.

Enhanced sensitivity of pancreatic cells to cholecystokinin octapeptide in obstructive jaundice

Exocrine function of the pancreas in obstructive jaundice was examined using dogs. Jaundice induced by choledochal ligation over 3 weeks showed pancreatic hypersecretion in response to cholecystokinin octapeptide (CCK-8) stimulation. To clarify the mechanism of pancreatic hypersecretion in obstructive jaundice, three experiments were undertaken. In a perfusion experiment performed on isolated pancreas, hypersecretion in obstructive jaundice was observed in response to CCK-8 stimulation. An incubation experiment showed an increase in secretion in response to CCK-8 stimulation in a dose-dependent manner, producing a greater increase in dogs with obstructive jaundice than in controls, despite the fact that basal secretion in both groups was the same. This would suggest that at least one of the mechanisms of pancreatic hypersecretion in obstructive jaundice may be related to the degree of sensitivity of acinar cells to CCK- 8. In morphological observation of acinar cells by electron microscopy, the average number of zymogen granules and total granular area per unit of cytoplasm in both groups before and after stimulation with CCK-8 were compared. There was no difference between the groups before stimulation. Following stimulation, values for the control group decreased but appeared to increase in the jaundiced pancreas. These results strongly suggest that pancreatic acinar cells in obstructive jaundice may retain their secretory potential after stimulation for 60 min, though the potential in nonjaundiced pancreatic acinar cells may decrease after stimulation.Exocrine function of the pancreas in obstructive jaundice was examined using dogs. Jaundice induced by choledochal ligation over 3 weeks showed pancreatic hypersecretion in response to cholecystokinin octapeptide (CCK-8) stimulation. To clarify the mechanism of pancreatic hypersecretion in obstructive jaundice, three experiments were undertaken. In a perfusion experiment performed on isolated pancreas, hypersecretion in obstructive jaundice was observed in response to CCK-8 stimulation. An incubation experiment showed an increase in secretion in response to CCK-8 stimulation in a dose-dependent manner, producing a greater increase in dogs with obstructive jaundice than in controls, despite the fact that basal secretion in both groups was the same. This would suggest that at least one of the mechanisms of pancreatic hypersecretion in obstructive jaundice may be related to the degree of sensitivity of acinar cells to CCK-8. In morphological observation of acinar cells by electron microscopy, the average number of zymogen granules and total granular area per unit of cytoplasm in both groups before and after stimulation with CCK-8 were compared. There was no difference between the groups before stimulation. Following stimulation, values for the control group decreased but appeared to increase in the jaundiced pancreas. These results strongly suggest that pancreatic acinar cells in obstructive jaundice may retain their secretory potential after stimulation for 60 min, though the potential in nonjaundiced pancreatic acinar cells may decrease after stimulation.