Biomedical subjects

Toshiaki Nakatsu

Publications and source records attributed to Toshiaki Nakatsu.

5 recordsLinked to original sources

PubMed2005

Estimation of the stent placement above the intact sphincter of Oddi against malignant bile duct obstruction.

BACKGROUND: In endoscopic biliary stenting against malignant biliary obstruction, stent blockage remains as an important problem. Stent blockage occurs as a result of bacterial adherence to the inner wall of the stent. We evaluated the stent placement above the intact sphincter of Oddi to retain the function of the sphincter of Oddi as a bacteriological barrier. METHODS: Sixteen patients with malignant biliary obstruction were assessed as the patients with the stent above the intact sphincter of Oddi. Sixteen patients with malignant biliary obstruction were assessed as the patients with the conventional stent placement across the sphincter of Oddi. Tannenbaum 10-Fr. stents were used in both the groups. RESULTS: The median patency periods of the stent were 255 days (25th to 75th percentiles, 212-454 days; range, 39-454 days) for the group of the stents placed above the sphincter of Oddi and 82 days (25th to 75th percentiles, 48-131 days; range, 22-196 days) for the group of the stents placed across the sphincter of Oddi, respectively, with significant difference (P = 0.0001). The occlusion rates of stents placed above and across the sphincter of Oddi were 37.5% and 93.8%, respectively, with significant difference (P = 0.0008). The dislocation rates of the stent were 0% and 6.3%, respectively (not significant). CONCLUSIONS: Placement of the stent above the intact sphincter of Oddi was associated with longer stent patency and lower occlusion rate.

Aged↗

PubMed2005

Pre-cutting using a noseless papillotome with independent lumens for contrast material and guidewire.

BACKGROUND: The technical success of therapeutic endoscopic retrograde cholangiopancreatography (ERCP) depends on selective cannulation into the bile duct. We have developed a new type of precut papillotome for selective cannulation. METHODS: The newly developed precut papillotome has been equipped not only with a lumen for contrast materials but also with an independent lumen for the guidewire. The operation of the guidewire and the injection of contrast material can be carried out simultaneously. The precut papillotome has a 20-mm-long knife and no leading tip. Half the proximal side of the knife is coated for insulation. RESULTS: Selective biliary cannulation failed in 26 of 293 patients (8.9%) in whom therapeutic ERCP was attempted. We applied the precut papillotome to these 26 patients and selective cannulation was successful in 24 of 26 patients (success rate: 92.3%). No major complications occurred, although mild bleeding, which did not require endoscopic hemostasis or blood transfusion, was observed only in one patient. CONCLUSIONS: Although further studies with a large number of patients are needed to evaluate the efficacy of the papillotome, this papillotome may contribute to increase the safety and the success rate of precutting.

Aged↗

PubMed2005

Enhanced expression of p46 Shc in the nucleus and p52 Shc in the cytoplasm of human gastric cancer.

Shc protein is known to be related to cell proliferation and carcinogenesis. However, the involvement of Shc in gastric cancer remains unknown. In the present study, we examined the expression and localization of Shc in human gastric cancer and the adjacent normal mucosa by Western blotting and immunohistochemical analyses. Furthermore, the expression of Shc in a gastric cancer cell line, MKN 28, was also studied. p66 Shc was not detected at all in gastric cancer or the adjacent normal mucosa. In contrast, immunohistochemical and Western blot analyses revealed that p52 Shc was detected in the cytoplasmic fractions obtained from gastric normal mucosa and cancer, while p46 Shc expression was observed in the nuclear fractions from gastric normal mucosa and cancer. Furthermore, not only p52 Shc expression in the cytoplasm but also p46 Shc expression in the nucleus was much higher in gastric cancer than in the adjacent normal mucosa. Subsequent in vitro experiments with MKN 28 gastric cancer cells also revealed that p52 Shc was expressed solely in the cytoplasm and p46 Shc was solely in the nucleus. These results suggest that the enhancement of p46 Shc and p52 Shc expression may be related to the occurrence of gastric cancer. Furthermore, unlike p52 Shc, p46 Shc was shown to be expressed solely in the nucleus, suggesting that p46 Shc expressed in the nucleus may play an important role in gastric carcinogenesis.

Adaptor Proteins, Signal Transducing↗

PubMed2003

Concomitant colitis associated with primary sclerosing cholangitis.

Between 1985 and 2001, seven Japanese patients (four males and three females) were diagnosed as having primary sclerosing cholangitis (PSC) in our hospital. All seven patients received total colonoscopy with distal ileoscopy. All four male patients were diagnosed as having colitis by colonoscopy, while none of the three female patients had colitis. The four patients with colitis did not have any symptoms attributable to colitis, such as diarrhea or hematochezia. In three of the four patients, unclassified colitis was the most suitable diagnosis, because there were no typical findings of ulcerative colitis or Crohn's disease. The remaining patient was diagnosed as having eosinophilic colitis. By colonoscopic visualization, the right-sided colon, including the terminal ileum, was mainly involved, but the lesions were not severe. The main findings were redness, erosion, stenosis, and insufficiency of haustral formation. Histologically, these lesions were nonspecific inflammatory changes in the three patients with unclassified colitis. In the patient with eosinophilic colitis, remarkable infiltration of eosinophils was observed. Thus, unclassified colitis appeared to be the main complication in these patients with PSC. Males predominated in regard to concomitant colitis, and they had no symptoms of the colitis. Colonoscopic examination revealed that the lesions were not severe. The main lesions were found in the right-sided colon, with nonspecific inflammatory changes. These results suggest that colonoscopic surveillance of patients with PSC should be performed even if they do not have any colitis symptoms.

Adult↗

PubMed2003

Combination of assay of human telomerase reverse transcriptase mRNA and cytology using bile obtained by endoscopic transpapillary catheterization into the gallbladder for diagnosis of gallbladder carcinoma.

OBJECTIVES: It is difficult to make accurate diagnoses of polypoid lesions in the gallbladder. To increase the diagnostic accuracy, we have developed an endoscopic technique to obtain gallbladder bile, termed endoscopic transpapillary catheterization into the gallbladder (ETCG). We evaluated the usefulness of a molecular biological approach to the diagnosis of gallbladder carcinoma, in which gallbladder bile obtained by the ETCG technique is used. METHODS: Twenty patients undergoing an operation because of suspicion of gallbladder carcinoma were enrolled. Twelve patients were confirmed to have gallbladder carcinoma, and four were found to have chronic cholecystitis. Two patients with polypoid lesion were diagnosed as having an inflammatory polyp and a hyperplastic polyp, respectively. The remaining two patients with polypoid lesions were diagnosed as having a cholesterol polyp. Gallbladder bile collected by the ETCG technique was evaluated cytologically and also analyzed for telomerase activity and mRNA for human telomerase reverse transcriptase (hTERT), the catalytic subunit of telomerase. In 14 patients, hTERT mRNA in resected specimens (fixed in 10% formalin and embedded in paraffin) was also examined. RESULTS: Cytology of gallbladder bile was positive in eight of 11 examined patients (72.7%) with gallbladder carcinoma. hTERT mRNA was detectable in gallbladder bile as well as in resected neoplastic tissues in four of 12 patients (33.3%) with carcinoma. Conversely, telomerase activity was negative in all eight examined patients with carcinoma. Overall, either cytology or hTERT mRNA of gallbladder bile was positive in 10 of 12 patients (83.3%) with gallbladder carcinoma. Cytology, hTERT mRNA, and telomerase activity were negative in eight patients with benign disease. CONCLUSIONS: The combination of cytology and hTERT mRNA analysis of gallbladder bile might be helpful for the preoperative diagnosis of gallbladder carcinoma.

Adult↗