Biomedical subjects

Atsutake Okamoto

Publications and source records attributed to Atsutake Okamoto.

53 records · Page 3Linked to original sources

PubMed2003

[Metastatic gastrointestinal stromal tumors responded to the treatment with STI571 after polysurgery for recurrent lesions--report of two cases].

Two cases of metastatic gastrointestinal stromal tumors (GIST) that had responded to the treatment with STI571 were presented. Case 1 was a 49-year-old woman who had undergone proximal gastrectomy because of a giant submucosal tumor of the stomach. For 21 months after surgery, the patient received repeated tumor removal four times due to hepatic metastasis and/or peritoneal recurrence. Thereafter, the treatment with STI571 at a dose of 400 mg/day was initiated. Eight months after the administration, only a small hepatic metastasis was detected on a film of CT scan, and any signs of peritoneal recurrence were observed. Case 2 was a 61-year-old man who underwent emergency surgery for a retroperitoneal tumor that had caused massive intestinal hemorrhage resulting in critical shock. The patient underwent the surgery three times for recurrent lesions. Because further tumor removal had become nearly impossible, STI571 at a dose of 400 mg/day was administered 35 months after initial surgery. Six months after treatment the hepatic lesions were shrunk, but the number of retroperitoneal lesions increased. At present, the patient has no abdominal complaints and has a good quality of life. GIST was confirmed in both cases, by histopathological analyses of the resected specimens: positive expression of c-kit and CD34. These clinical observations suggest that ST1571 therapy for metastatic lesions from GIST may be preferred over aggressive, repeated tumor removal.

Administration, Oral↗

PubMed2003

[Novel chemoradiotherapy for locally advanced pancreatic cancer using arterial infusion chemotherapy following the alteration of peripancreatic blood flow].

Radiotherapy employing intraoperative radiation therapy (IORT) in combination with postoperative external beam radiation therapy (EBRT) is an effective treatment for unresectable pancreatic cancer. To achieve an even greater therapeutic outcome, 13 patients with unresectable pancreatic cancer were treated by IORT in combination with EBRT plus locally intensive arterial infusion chemotherapy. In order to increase drug delivery to the primary tumor, the splenic and major pancreatic arteries, except for the gastroduodenal artery (GDA), were embolized by radiological intervention prior to the arterial infusion chemotherapy, and the administration of gemcitabine, CDDP, and 5-FU to the primary tumors via GDA was followed during EBRT. The values of serum tumor markers were decreased in all patients, and tumor regression was detected on CT scans in 6 patients. The evaluation of survival benefit of this treatment modality is ongoing, but it did not prolong the survival time of patients with second stage lymph node metastases. One of the advantages of this method was able to perform also in charge of hepatic arterial infusion chemotherapy concurrently, but we experienced liver abscess in 2 patients.

Aged↗

PubMed2002

Clinical significance of a long common channel.

BACKGROUND/AIM: It was reported that in only 19 (11%) of 173 patients was the common channel at the junction of the pancreatic and bile ducts found to be 6 mm or longer. Pancreaticobiliary maljunction (PBM) is defined as an anomaly with a markedly long common channel with the junction located outside the duodenal wall, so the action of the sphincter of Oddi does not functionally affect the junction. We defined high confluence of pancreaticobiliary ducts (HCPBD) as a length of the common channel > or = 6 mm, in which the communication between the pancreatic and bile ducts was occluded when the sphincter was contracted. This study aims at investigating the clinical significance of HCPBD. METHODS: 2,980 consecutive cases with an adequate endoscopic retrograde cholangiopancreatography were reviewed. PBM and HCPBD were diagnosed according to the above definitions. PBM was divided into two groups: with or without biliary dilatation. RESULTS: PBM and HCPBD were detected in 63 (2.1%) and 50 (1.7%) cases, respectively. Biliary dilatation was detected in 30 cases having PBM. The incidences of gallbladder carcinoma associated with PBM with or without biliary dilatation and HCPBD were 13, 67, and 12%, being significantly higher than in controls (p < 0.05, p < 0.01, and p < 0.05). Pancreatic ductal reflux was detected in 11 (85%) of 13 patients with HCPBD in whom postoperative T tube cholangiograms were performed, and acute pancreatitis occurred in 14 (24%) of the 50 patients with HCPBD. CONCLUSIONS: HCPBD may be an intermediate variant of PBM. It is necessary to pay attention to an associated gallbladder carcinoma in patients with HCPBD as well as in those with PBM.

Adolescent↗

PubMed2002

A case of solid pseudopapillary neoplasm of the pancreas and tumor doubling time.

BACKGROUND: Solid pseudopapillary neoplasm of the pancreas is a rare tumor with unique clinicopathological features. Although it is considered to grow slowly, little is known about its doubling time. METHOD: We encountered a young Japanese woman with a solid pseudopapillary neoplasm of the pancreas that had been detected at another hospital 5 years previously but was resected at our hospital. The tumor showed only a solid component without any cysts. Computed tomographic scans taken 5 years apart were compared to determine the tumor doubling time. RESULT: The tumor doubling time according to the formula of Schwartz and co-workers was determined to be 765 days. CONCLUSION: These findings confirm that this tumor grows quite slowly and also support long disease-free periods even in patients who have recurrence or metastases.

Adult↗

PubMedDate not supplied

Acute pancreatitis and a long common channel.

BACKGROUND: As sphincter action does not functionally affect the union in pancreaticobiliary maljunction (PBM), two-way regurgitation occurs. We investigated the features of acute pancreatitis associated with patients displaying a long common channel. METHODS: We reviewed 3210 endoscopic retrograde cholangiopancreatograms. PBM was diagnosed in 107 patients with a long common channel in which communication between the pancreatic and bile duct was maintained even during sphincter contraction. High confluence of pancreaticobiliary ducts (HCPBD) was diagnosed in 60 patients with a common channel >or=6 mm long in which communication between the two ducts was occluded with sphincter contraction. RESULTS: Of patients with PBM, four had acute pancreatitis. Etiology of acute pancreatitis in the two patients was suspected to involve impaction in a long common channel. Of patients with HCPBD, 17 displayed acute pancreatitis. Three patients had a history of excessive alcohol intake and 10 patients were associated with choledocholithiasis or cholecystitis. The remaining four patients had no history of them. CONCLUSIONS: Acute pancreatitis occurs in 13% of patients with a long common channel. Obstruction of a long common channel by stones easily induces bile flow into the pancreas. Even if no obstruction is present, biliopancreatic reflux induces acute pancreatitis in some patients.

Acute Disease↗

PubMedDate not supplied

Extrapancreatic lesions in autoimmune pancreatitis.

GOALS: To examine extrapancreatic lesions associated with autoimmune pancreatitis. BACKGROUND: Autoimmune pancreatitis is a unique clinical entity proposed recently, and is reported to occasionally be associated with other autoimmune diseases. STUDY: Extrapancreatic lesions were examined clinically, radiologically, and histologically in 25 patients with autoimmune pancreatitis. RESULTS: Stenosis of the bile duct was observed in 22 patients (lower bile duct [n = 19], upper bile duct [n = 1], intrahepatic bile duct [n = 2]). Marked extrapancreatic bile duct wall thickening not associated with obvious cholangiographic abnormality was seen on ultrasound in 3 patients. Enlargement of the salivary glands and cervical lymph nodes was detected in 4 patients. Abdominal lymphadenopathy was observed in 5 of 8 patients at laparotomy. Retroperitoneal fibrosis was noted in 2 patients. Obliterative phlebitis of the pancreatic and peripancreatic veins was observed histologically in all 6 resected specimens. Marked stenosis of the portal vein and encasement of the peripancreatic arteries was observed in 4 and 8 of 14 patients who underwent abdominal angiography, respectively. Diabetes mellitus was diagnosed in 13 patients. All associated extrapancreatic lesions except diabetes mellitus improved after steroid therapy. CONCLUSIONS: Extrapancreatic lesions found to be occasionally associated with autoimmune pancreatitis were stenosis of the bile duct, enlargement of the salivary glands, abdominal or cervical lymphadenopathy, retroperitoneal fibrosis, stenosis of the peripancreatic arteries or portal vein, and diabetes mellitus. It is possible that these lesions are induced by the same inflammatory mechanisms as autoimmune pancreatitis.

Autoimmune Diseases↗

PubMedDate not supplied

Impact of selective Glisson transection on survival of hepatocellular carcinoma.

BACKGROUND/AIMS: The aim of this study is to assess whether selective transection of tumor-bearing portal pedicle before dissection of the liver parenchyma in hepatectomy for hepatocellular carcinoma can prevent intraoperative spread of the tumor and can lead to the prolongation of postoperative survival. METHODOLOGY: Survival for 159 patients who underwent hepatectomies with selective portal transection by Glissonean pedicle transection method was retrospectively compared with that of 100 patients who underwent hepatectomies with Pringle maneuver. According to the number of recurrent tumors, intrahepatic recurrence was divided into two types: nodular type of 3 or less, diffuse type of 4 or more. RESULTS: The 5-year survival for the patients who underwent hepatectomies with Glissonean pedicle transection method was significantly higher than that with Pringle maneuver (64.7% vs. 36.4%, p < 0.0001, log-rank test). The diffuse type recurrence, which occurred early and resulted in the unfavorable prognosis compared with the nodular type, was significantly reduced in patients treated with Glissonean pedicle transection method compared with those with Pringle maneuver (p = 0.0013). Multivariate analyses demonstrated that Glissonean pedicle transection method was a potent independent prognostic indicator for survival. CONCLUSIONS: Glissonean pedicle transection method prevented intraoperative metastasis and significantly improved the postoperative survival in patients with hepatocellular carcinoma.

Carcinoma, Hepatocellular↗

PubMedDate not supplied

Survival benefit of KRN7000 immune therapy in combination with TNP470 in hamster liver metastasis model of pancreatic cancer.

Pancreatic cancer is a solid malignancy with the poor prognosis largely due to frequent and lethal liver metastases. The combination of immunotherapy and anti-angiogenesis therapy might be a hopeful strategy for the treatment of distant metastases. The benefits of the combination therapy by an immune stimulator alpha-galactosylceramide (KRN7000) and an angiogenesis inhibitor AGM-1470 (TNP470) were evaluated on the hamster highly aggressive liver metastasis model using the syngeneic pancreatic cancer cell line HPD-NR. KRN7000 immediately activated hepatic mono-nuclear cells to produce IFN-gamma in vitro. Intraportal injection of KRN7000 exhibited a dense accumulation of CD4-CD8- natural killer T cells, around the liver metastases in vivo. KRN7000 treatment significantly inhibited the growth of liver metastases, and importantly, significant survival prolongation was confirmed when TNP470 treatment was added to it. Furthermore, cytotoxic T lymphocytes were induced at the sites of a few residual metastases in the liver of a long-term survivor. Thus, the combination of KRN7000 and TNP470 showed a high effectiveness for the treatment of liver metastases of pancreatic cancer.

Adjuvants, Immunologic↗

PubMedDate not supplied

Pancreatitis associated with pancreaticobiliary maljunction.

BACKGROUND/AIMS: Pancreaticobiliary maljunction is a rare anomaly, but causes various pathological conditions in the biliary tract and the pancreas. This study aims at clarifying the features of pancreatitis associated with pancreaticobiliary maljunction. METHODOLOGY: A total of 100 patients with pancreaticobiliary maljunction were reviewed. Clinical findings and cholangiopancreatographic results in patients with acute or chronic pancreatitis associated with pancreaticobiliary maljunction were analyzed. RESULTS: Of 100 patients, 14 had pancreatic disorders: acute pancreatitis (n = 3), chronic pancreatitis (n = 5), hyperamylasemia (n = 4), and pancreatic carcinoma (n = 2). The acute pancreatitis was mild (n = 3) and relapsing (n = 2). In patients with chronic pancreatitis, pancreatic stones (n = 2) and radiolucent protein plugs (n = 2) were detected only in the dilated common channel or in the main pancreatic duct near the common channel. Two patients received cyst-duodenostomy in the infant developed chronic pancreatitis 11 and 27 years later. CONCLUSIONS: Acute or chronic pancreatitis was sometimes associated with pancreaticobiliary maljunction. These pancreatitis cases showed different clinical and pancreatographic findings from others. These differences might be due to the peculiar mechanism that they were induced by bile reflux into the pancreatic duct via the anomalous connection.

Acute Disease↗

PubMedDate not supplied

Clinical significance of the accessory pancreatic duct.

BACKGROUND/AIMS: The accessory pancreatic duct is the smaller and less constant pancreatic duct in comparison with the main pancreatic duct. We investigated the patency of the accessory pancreatic duct and its role in pancreatic pathophysiology. METHODOLOGY: Dye-injection endoscopic retrograde pancreatography was performed in 411 patients. In patients in whom the main pancreatic duct could be selectively cannulated, contrast medium with indigo carmine was injected through the catheter. Excretion of the dye from the minor duodenal papilla was observed endoscopically. RESULTS: Patency of the accessory pancreatic duct was 43% of the 291 control cases. In the 46 patients with acute pancreatitis, 8 (17%) had a patent accessory pancreatic duct. The difference in patency between this group and the normal group was significant (p < 0.01). Especially, patency of the accessory pancreatic duct was only 8% of the 13 patients with acute biliary pancreatitis. In the patients with pancreaticobiliary maljunction, biliary carcinoma occurred in 72% of patients with a nonpatent accessory pancreatic duct, but in contrast, it occurred only in 30% of those with a patent accessory pancreatic duct. This difference was significant (p < 0.05). Lower amylase level in the bile of patients with pancreaticobiliary maljunction with a patent accessory pancreatic duct was frequently observed than those with a nonpatent accessory pancreatic duct. CONCLUSIONS: A patent accessory pancreatic duct may prevent acute pancreatitis by lowering the pressure in the main pancreatic duct. In cases of pancreaticobiliary maljunction with a patent accessory pancreatic duct, the incidence of carcinogenesis of the bile duct might be lower, as the reflux of the pancreatic juice to the bile duct might be reduced by the flow of the pancreatic juice into the duodenum through the accessory pancreatic duct.

Acute Disease↗

PubMedDate not supplied

An investigation of primary malignancies associated with ampullary carcinoma.

BACKGROUND/AIMS: As ampullary carcinoma has a favorable prognosis, associated malignancies have potential prognostic significance in these patients. This study focused on the incidence and characteristics of preexisting, coexisting and subsequent malignancies in patients with ampullary carcinoma. METHODOLOGY: Sixty-four cases of ampullary carcinoma were retrospectively identified. Fifty-four patients underwent surgical resection, while in the other ten, histological diagnosis was reached after biopsy and/or autopsy. Other primary malignancies associated with ampullary carcinoma, occurring in the prediagnostic or postdiagnostic period, were investigated. The mean postdiagnostic follow-up period was 3.9 years (range, 0-23 years). RESULTS: Other malignancies occurred in 17 patients (27%), being found before (n=9), at (n=7), or after (n=5) diagnosis of ampullary carcinoma. The total number of associated lesions was 23, including one case of quadruple and four cases of triple carcinoma. The major associated malignancies were colonic carcinoma (n=9), gastric carcinoma (n=5), and uterine carcinoma (n=3). Twenty-one lesions were treated surgically or endoscopically. One patient died from synchronous extrahepatic bile duct carcinoma and one from leukemia, and one died from subsequent urinary bladder carcinoma. Development of other malignancies was related to age but not to gender, family history, adjuvant chemo/radiotherapy, or tumor pathology. CONCLUSIONS: Ampullary carcinoma is associated with a high incidence of other malignancies, particularly colonic and gastric carcinomas. The possibility of associated malignancies should therefore be considered in preoperative screening and postoperative follow-up of patients with ampullary carcinoma.

Aged↗

PubMedDate not supplied

Pancreatitis associated with congenital abnormalities of the pancreaticobiliary system.

BACKGROUND/AIMS: The relationship between pancreas divisum and pancreatitis remains controversial. The aim of this study was to examine the frequency and features of pancreatitis associated with congenital abnormalities of the pancreaticobiliary system, and the role that these malformations have in the occurrence of pancreatitis. METHODOLOGY: We retrospectively examined endoscopic retrograde cholangiopancreatograms of 6850 patients including 186 patients who were diagnosed clinically as having acute pancreatitis and 211 who were diagnosed as having chronic pancreatitis. RESULTS: A total of 175 patients were diagnosed as having congenital abnormalities of pancreaticobiliary system. Acute and chronic pancreatitis was associated respectively with 3.0% and 5.0% of patients with pancreaticobiliary maljunction (n=100), 17.1% and 28.6% of those with pancreas divisum (n=35), 6.6% and 20.0% of those with partial pancreas divisum (n=30), and 16.7% and 33.3% of those with choledochocele (n=6). These anomalies were present in 6.5% and 10.9% of patients with acute and chronic pancreatitis, respectively. Isolated chronic dorsal pancreatitis was detected in 8 patients with pancreas divisum. In chronic pancreatitis associated with pancreaticobiliary maljunction, pancreatic stones or protein plugs were situated only in the dilated common channel or main pancreatic duct of the head. CONCLUSIONS: Congenital abnormalities of the pancreaticobiliary system constitute one etiology of pancreatitis.

Acute Disease↗

PubMedDate not supplied

Thermo-chemo-radiotherapy for advanced gallbladder carcinoma.

BACKGROUND/AIMS: Many gallbladder carcinomas are detected at an advanced stage, and the outcome of the patients with these tumors is dismal despite aggressive tumor removal. We have treated advanced gallbladder carcinoma with chemoradiotherapy combined with hyperthermia. In this study, clinical effectiveness of thermo-chemo-radiotherapy (TCRT) for advanced gallbladder carcinoma was evaluated in comparison with other treatment modalities. METHODOLOGY: Two hundred and seventy patients with advanced gallbladder carcinoma (Stage VI) were treated. According to treatments received, they were divided into five groups as follows: group 1; 30 patients treated with TCRT, group 2; 19 patients underwent R0-resection, group 3; 39 patients underwent R1,2-resection, group 4; 57 patients treated with chemo- and/or radiotherapy, group 5; 125 patients with only supportive therapy. RESULTS: In group 1, there were 19 objective responses (5 complete response and 14 partial response) in respect to tumor regression, and 15 (6 complete response and 9 partial response) of 20 patients with obstructed bile duct showed resolution of the bile duct. The survival rate was best in group 2. A significant improvement of long-term survival was exhibited in group 1 and 3 compared to group 4 and 5, and there was no significant difference between group 1 and 3 (p<0.01). CONCLUSIONS: TCRT can produce significant response and improvement of survival time in patients with advanced gallbladder carcinoma, and may be a favorable alternative to aggressive surgical approaches.

Adult↗

PubMedDate not supplied

Chronic pancreatitis progressing from segmental lesions.

BACKGROUND/AIMS: Chronic pancreatitis is histologically and functionally a progressive disease. To examine the natural history of chronic pancreatitis, we evaluated serial pancreatography in cases of chronic pancreatitis, focusing on the progression of diffuse-type chronic pancreatitis from the segmental type. METHODOLOGY: We reviewed 57 patients with chronic pancreatitis who had undergone endoscopic retrograde pancreatography on more than 2 occasions at intervals of at least 1 year. Cases of chronic pancreatitis were categorized as diffuse (n=37) and segmental (n=20) on the findings of initial endoscopic retrograde pancreatography. RESULTS: Twenty-three cases of diffuse-type chronic pancreatitis showed progression of pancreatic duct abnormalities. Segmental abnormalities of the main pancreatic duct at the body or tail of the pancreas spread to the head of the pancreas in 8 cases. Etiologies of these cases of chronic pancreatitis were alcoholic, in which patients continued drinking after initial endoscopic retrograde pancreatography. In 2 patients who underwent distal pancreatectomy, although segmental lesions showed typical histological findings of alcoholic chronic pancreatitis, appearances near the margin of these lesions were almost normal or indicated slight interlobular fibrosis. CONCLUSIONS: The pancreatic tail might represent the site of the initial lesion in some cases of alcoholic pancreatitis.

Adult↗

PubMedDate not supplied

Digestion and absorption of patients with autoimmune pancreatitis.

BACKGROUND/AIMS: In patients with autoimmune pancreatitis, radiological, serological and pancreatic functional abnormalities usually improve with steroid therapy. However, no studies have specifically focused on digestion and absorption in such patients. This study aims to investigate digestion and absorption, in addition to pancreatic endocrine and exocrine function, and their responses to steroid therapy in patients with autoimmune pancreatitis. METHODOLOGY: Ideal body weight index, levels of serum albumin, total cholesterol and glucose, or glycosylated hemoglobin values were investigated in 22 patients with autoimmune pancreatitis. N-benzoyl-L-tyrosyl-paraminobenzoic acid excretion test was performed in 9 patients. In 10 patients treated with steroids, these factors were examined again about 2 months after medication. RESULTS: Levels of serum albumin decreased, while ideal body weight index and levels of serum albumin and cholesterol significantly increased after steroid therapy. Eleven (50%) patients showed evidence of diabetes mellitus, but this improved in 6 of 8 patients treated with steroids. Pancreatic exocrine function was reduced in 88% of patients. Impaired pancreatic exocrine function improved after steroid therapy in 3 of 7 patients treated. CONCLUSIONS: Mild malnutrition as well as impaired pancreatic endocrine and exocrine function were frequently detected in patients with autoimmune pancreatitis. Steroid therapy was occasionally effective for these conditions.

Adult↗

PubMedDate not supplied

Biliary carcinoma risk in patients with pancreaticobiliary maljunction and the degree of extrahepatic bile duct dilatation.

BACKGROUND/AIMS: Pancreaticobiliary maljunction (PBM) carries a high risk of biliary carcinoma. This study aimed to examine the biliary complications of patients with PBM in relation to the degree of extra-hepatic bile duct dilatation. METHODOLOGY: Ninety-eight cases of PBM could be divided into 5 groups according to the maximum diameter of the extrahepatic bile duct: < or = 10mm, 11-15mm, 16-20mm, 21-30mm, > or = 31mm. The clinicopathological findings of biliary carcinomas associated with PBM were compared with 232 cases of gallbladder carcinoma and 159 cases of bile duct carcinoma that were not associated with PBM. RESULTS: Gallbladder carcinoma occurred in 36 of 65 patients (55%) with PBM whose maximum diameter of the extrahepatic bile duct was < or = 30mm, but no gallbladder carcinoma occurred in patients with PBM whose diameter was > or = 31mm. Bile duct carcinoma occurred in 6 of 52 patients (12%) with PBM whose diameter was > or = 21mm, but no bile duct carcinoma occurred in patients with PBM whose diameter was < or = 20mm. The age at diagnosis of the patients with gallbladder or bile duct carcinoma associated with PBM was significantly younger than those without PBM (p<0.01). CONCLUSIONS: PBM with an extrahepatic bile duct diameter < or = 30mm is associated with a high risk of gallbladder carcinoma. PBM with an extrahepatic bile duct diameter > or = 21mm is associated with a high risk of bile duct carcinoma. Prophylactic cholecystectomy is recommended for patients with PBM without biliary dilatation.

Adolescent↗

PubMedDate not supplied

Comparison of radiological and histological findings in autoimmune pancreatitis.

BACKGROUND/AIMS: Autoimmune pancreatitis displays radiological findings that are sometimes difficult to differentiate from pancreatic carcinoma. To understand the essential radiological features of autoimmune pancreatitis (AIP), we compared imaging and histological findings in resected AIP specimens. METHODOLOGY: Findings of ultrasonography, computed tomography, endoscopic retrograde cholangiopancreatography and angiography were examined retrospectively for 6 patients who underwent pancreatoduodenectomy on suspicion of pancreatic carcinoma, and compared with histological findings of the resected specimens. RESULTS: Ultrasonography showed an enlarged hypoechoic pancreas with sausage-like appearance and no lobulation in the contour of the pancreas. On computed tomography imaging, delayed enhancement of the swollen pancreatic parenchyma became evident. Dense lymphoplasmacytic infiltration with fibrosis involving peripancreatic tissue was observed throughout almost the entire pancreas. Periductal non-occlusive fibrosis with lymphoplasmacytic infiltration induced narrowing of the pancreatic duct. Stenosis of the common bile duct is frequently associated with autoimmune pancreatitis and is induced by diffuse thickening of the duct wall by the same inflammatory process as that of the pancreas. The fibroinflammatory process also involves blood vessels. CONCLUSIONS: Characteristic radiological findings of autoimmune pancreatitis are induced with systemic histological changes of lymphoplasmacytic infiltration with fibrosis, and differ from schirrous invasion of pancreatic carcinoma.

Aged↗