Direct peroral cholangioscopy with red dichromatic imaging 3 detected the perihilar margin of superficial papillary extension in a patient with intraductal papillary neoplasm of the bile duct.

Intraductal papillary neoplasms of the bile duct (IPNB) are a tumor derived from bile duct epithelium that tends to spread laterally and non-invasively. Surgery is the first-choice treatment for IPNB. It is extremely important to accurately diagnose the extent of lateral tumor extension. Although peroral cholangioscopy (POCS) is a potentially useful modality for detecting tumor range with direct observation, poor image quality is a limitation of POCS. Recently, a new-generation endoscopy system (EVIS X1) was equipped with functions such as red dichromatic imaging to improve image quality. A 75-year-old man with cholangitis was referred to our department. Various imaging studies showed a mass in the middle to lower bile duct and dilatation of the common bile duct and the intrahepatic bile duct. Endoscopic retrograde cholangiopancreatography was performed. A biopsy of the main tumor in the lower common bile duct revealed IPNB. It was difficult to determine the extent of superficial tumor extension with modalities such as contrast-enhanced computed tomography, magnetic resonance imaging, and endoscopic ultrasonography but the detailed evaluation was possible using POCS with red dichromatic imaging 3. The patient underwent hepatopancreatoduodenectomy. This case suggests the usefulness of direct observation using POCS with red dichromatic imaging 3 to determine the range of IPNB.

Comparison of CEA and CA19-9 as a predictive factor for recurrence after curative gastrectomy in gastric cancer.

BACKGROUND: Our aim of was to compare importance of the tumor markers (TMs) serum carcinoembryonic antigen (CEA) and carbohydrate antigen (CA) 19-9 in prediction of recurrence after curative gastrectomy for gastric cancer. METHODS: We reviewed retrospectively the clinical records of 149 patients who underwent curative gastrectomy for stage I-III gastric cancer and whose CEA and CA19-9 levels were determined once preoperatively and for more than 3 years postoperatively. We investigated whether the clinicopathological characteristics of patients including age, sex, pathological disease stage, operative approach, type of gastrectomy, and degree of lymph node dissection as well as preoperative positivity of CEA and CA19-9 were risk factors for recurrence in univariate and multivariate analyses. Rate of recurrence was compared between patients positive and negative for postoperative CEA or CA19-9. We also calculated sensitivity, specificity, positive and negative predictable values of postoperative positivity of CEA and CA19-9 for recurrence. The lead time was compared between CEA and CA19-9 that was defined as the time of the first detection of increases in tumor markers and confirmation of recurrence on imaging modalities. RESULTS: The number of patients positive for preoperative CEA was 25 (17%) and for CA19-9 was 11 (7%). Recurrence was confirmed in 29 (19%) patients. Stage III disease, preoperative positivity for CA19-9 but not CEA, and total gastrectomy were risk factors for recurrence in univariate analysis, but stage III disease was the only risk factor for recurrence in multivariate analysis. Forty and 15 patients were positive for postoperative CEA and CA19-9, respectively. The recurrence rate of 47% (7/15) in patients positive for postoperative CA19-9 was greater than that in negative patients (22/134 = 16%), but it did not differ between patients who were positive or negative for postoperative CEA. Specificity for CA19-9 was greater than that for CEA (P < 0.05). The lead time of CEA (3.9 ± 4.7 months) was not different from that of CA19-9 (6.1 ± 7.1 months). CONCLUSIONS: These results indicate that CA19-9 rather than CEA is likely to be more useful for the detection of recurrence after curative gastrectomy for gastric cancer.

Biliary Schwannoma That Required Differentiation from Bile Duct Cancer.

Schwannomas are benign tumors originating from Schwann cells, which are the main component of the neural sheath. Biliary schwannomas are extremely rare. We report the case of a 78-year-old man who presented with no abdominal symptoms or jaundice. CT imaging showed a hyperdense mass extending along the extrahepatic bile duct, and the upstream bile ducts were dilated. We performed extrahepatic bile duct resection under a preoperative diagnosis of the extrahepatic bile duct cancer. A histopathological examination of the resected specimen revealed that the tumor consisted of spindle cells which exhibited a palisading arrangement. Immunohistochemical staining was positive for protein S-100 and vimentin. Based on these pathological findings, we diagnosed the patient with schwannoma of the extrahepatic bile duct. Our search of the relevant literature revealed 19 case studies of biliary schwannomas. In our case, the surgical findings showed that the tumor was noninvasive and mobile. During surgery, a fast frozen section analysis was performed, and no malignant findings were observed. These results enabled us to avoid extrahepatic bile duct resection with major hepatectomy. We experienced a case of biliary schwannoma that was difficult to distinguish from bile duct cancer.

Influence of age on postoperative complications especially pneumonia after gastrectomy for gastric cancer.

BACKGROUND: The aim of this study was to investigate the influence of patients' age on postoperative morbidities including pneumonia. METHODS: We reviewed the clinical records of 211 patients with stages I - III gastric cancer undergoing curative distal gastrectomy (DG) or total gastrectomy (TG). Patients were classified into an elderly (≧80 y.o.) or a control (< 80 y.o.) group. We compared patient characteristics (sex ratio, disease stage, degree of lymph node dissection, number of retrieved lymph nodes, and type of reconstruction) and early postoperative outcomes (operation time, intra-operative blood loss, and postoperative morbidity including pneumonia, and mortality) between the two groups separately in DG and TG. RESULTS: There were 134 and 77 patients who underwent DG and TG, respectively. The numbers of patients in the elderly and control groups were 25 and 109 in DG and 12 and 65 in TG. The percentage of female patients in the elderly group was greater than that in the control group in both DG and TG. The extent of lymph node dissection did not differ between two groups in TG; in contrast in DG, the rate of a D1 dissection was greater in the elderly group than in the control group. There were no differences between the two groups in distribution of disease stage, number of retrieved lymph nodes, operation time, and blood loss in DG and in TG. Overall postoperative morbidity did not differ between two groups after DG and after TG. The rate of infectious complications in the elderly group was not different from that in the control group after DG and after TG. The incidence of pneumonia was more frequent in the elderly group compared to the control group after DG (8% vs. 1%, P < 0.05) but not after TG (17% vs. 5%). When patients were compared between the elderly and the control groups regardless of type of gastrectomy, the incidence of pneumonia in the elderly group (4/37 (11%)) was greater than that in the control group (4/174 (2%), P < 0.05). CONCLUSIONS: These results suggest that pneumonia is increased in patients older than 80 years after DG.

Development and application of multiple-probe scanning probe microscopes.

In the research of advanced materials based on nanoscience and nanotechnology, it is often desirable to measure nanoscale local electrical conductivity at a designated position of a given sample. For this purpose, multiple-probe scanning probe microscopes (MP-SPMs), in which two, three or four scanning tunneling microscope (STM) or atomic force microscope (AFM) probes are operated independently, have been developed. Each probe in an MP-SPM is used not only for observing high-resolution STM or AFM images but also for forming an electrical contact enabling nanoscale local electrical conductivity measurement. The world's first double-probe STM (DP-STM) developed by the authors, which was subsequently modified to a triple-probe STM (TP-STM), has been used to measure the conductivities of one-dimensional metal nanowires and carbon nanotubes and also two-dimensional molecular films. A quadruple-probe STM (QP-STM) has also been developed and used to measure the conductivity of two-dimensional molecular films without the ambiguity of contact resistance between the probe and sample. Moreover, a quadruple-probe AFM (QP-AFM) with four conductive tuning-fork-type self-detection force sensing probes has been developed to measure the conductivity of a nanostructure on an insulating substrate. A general-purpose computer software to control four probes at the same time has also been developed and used in the operation of the QP-AFM. These developments and applications of MP-SPMs are reviewed in this paper.

Adenocarcinoma of the minor duodenal papilla: report of a case.

An 81-year-old male was found to have a duodenal tumor by screening upper gastrointestinal endoscopy. The tumor was located in the minor duodenal papilla. Pathological examination of the biopsy specimen revealed adenocarcinoma, and endoscopic ultrasound showed an elevated hypoechoic mass in the minor duodenal papilla. The preoperative diagnosis was therefore considered to be either adenocarcinoma of the minor duodenal papilla or duodenal cancer. We performed a subtotal stomach-preserving pancreaticoduodenectomy. Histopathological examination of the resected specimen showed the tumor cells to be primarily located in the submucosa of the minor duodenal papilla, with slight invasion into the pancreatic parenchyma through the accessory pancreatic duct. We therefore diagnosed a primary adenocarcima of the minor duodenal papilla. Adenocarcinoma of the minor duodenal papilla is considered to be a rare disease, but it may be underestimated because of the difficulty in distinguishing advanced adenocarcinoma of the minor duodenal papilla from primary duodenal cancer and cancer of the pancreatic head.

Down-regulation of cIAP2 enhances 5-FU sensitivity through the apoptotic pathway in human colon cancer cells.

Currently 5-fluorouracil (5-FU) plays a central role in the chemotherapeutic regimens for colorectal cancers and thus it is important to understand the mechanisms that determine 5-FU sensitivity. The expression profiles of human colon cancer cell line DLD-1, its 5-FU-resistant subclone DLD-1/FU and a further 21 types of colon cancer cell lines were compared to identify the novel genes defining the sensitivity to 5-FU and to estimate which population of genes is responsible for 5-FU sensitivity. In the hierarchical clustering, DLD-1 and DLD-1/FU were most closely clustered despite over 100 times difference in their 50% inhibitory concentration of 5-FU. In DLD-1/FU, the population of genes differentially expressed compared to DLD-1 was limited to 3.3%, although it ranged from 4.8% to 24.0% in the other 21 cell lines, thus indicating that the difference of 5-FU sensitivity was defined by a limited number of genes. Next, the role of the cellular inhibitor of apoptosis 2 (cIAP2) gene, which was up-regulated in DLD-1/FU, was investigated for 5-FU resistance using RNA interference. The down-regulation of cIAP2 efficiently enhanced 5-FU sensitivity, the activation of caspase 3/7 and apoptosis under exposure to 5-FU. The immunohistochemistry of cIAP2 in cancer and corresponding normal tissues from colorectal cancer patients in stage III revealed that cIAP2 was more frequently expressed in cancer tissues than in normal tissues, and cIAP2-positive patients had a trend toward early recurrence after fluorouracil-based chemotherapy. Although the association between drug sensitivity and the IAP family in colorectal cancer has not yet been discussed, cIAP2 may therefore play an important role as a target therapy in colorectal cancer.

Granulocyte-colony stimulating factor-producing pancreatic cancer: report of a case.

A 74-year-old man was hospitalized for the investigation of fever and severe general fatigue. Laboratory examinations revealed severe leukocytosis, with a leukocyte count of 29 500/mm(3). Computed tomography, ultrasonography, and endoscopic retrograde cholangiopancreatography showed a pancreatic tumor with a diameter of 70 mm. We performed distal pancreatectomy with splenectomy and gastrectomy because there was invasion of the posterior wall of the stomach. The leukocyte count decreased to 16 900/mm(3) immediately following the operation, but it began to increase again a week later, ultimately reaching 213 000/mm(3). We measured the serum granulocyte-colony stimulating factor (G-CSF) concentration and the G-CSF expressions in the resected specimens with immunohistochemistry, the findings of which confirmed the diagnosis of G-CSF-producing pancreatic cancer. G-CSF-producing tumors are considered to be in a category of rare malignant diseases originating in various organs, which carry a poor prognosis. However, G-CSF-producing pancreatic cancer is extremely rare. On postoperative day (POD) 35, an intraabdominal recurrence was detected with marked leukocytosis, and on POD 42 the patient died without receiving postoperative cancer therapy.

Development of a scanning tunneling microscope for in situ experiments with a synchrotron radiation hard-X-ray microbeam.

A scanning tunneling microscope dedicated to in situ experiments under the irradiation of highly brilliant hard-X-rays of synchrotron radiation has been developed. In situ scanning tunneling microscopy (STM) observation was enabled by developing an accurate alignment system in ultrahigh vacuum. Despite the noisy conditions of the synchrotron radiation facility and the radiation load around the probe tip, STM images were successfully obtained at atomic resolution. Tip-current spectra were obtained for Ge nano-islands on a clean Si(111) surface by changing the incident photon energy across the Ge absorption edge. A current modification was detected at the absorption edge with a spatial resolution of the order of 10 nm.