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Y Maehara

Publications and source records attributed to Y Maehara.

At least 19 recordsLinked to original sources
PubMed2006

A case of an inflammatory myofibroblastic tumor in the lung which expressed TPM3-ALK gene fusion.

We herein describe a 4-year-old boy who after being treated for pneumonia showed an abnormal shadow at the hilus of the right lung on chest X-rays with continued inflammatory findings in his laboratory data. CT and MR investigations suggested the existence of a neoplasm at that site. An open biopsy was thus performed for a definite diagnosis. The histological findings and the expression of TPM3-ALK fusion gene confirmed a diagnosis of an inflammatory myofibroblastic tumor. A right upper and middle lobectomy including the tumor was thus performed for a complete resection. In addition to the histological diagnosis, the detection of the tumor specific fusion gene provided objective evidence in making a diagnosis.

Anaplastic Lymphoma Kinase↗
PubMed2006

Development and assessment of morphologic criteria for diagnosing gastric cancer using confocal endomicroscopy: an ex vivo and in vivo study.

BACKGROUND AND STUDY AIMS: The Confocal Endomicroscopy System (Optiscan Pty Ltd. and Pentax Corp.) is a newly developed imaging tool that uses laser light and optical technology to visualize living tissue at the cellular level. Digital images of cells magnified 1000-fold appear in real time on a computer screen, which enables immediate detection of changes in cellular structure without the need for a biopsy. The aim of this study was to assess the features of the cellular architecture of cancerous tissue that can be used in the differential diagnosis of cancerous tissue and normal mucosa using this system's image-processing software. PATIENTS AND METHODS: A total of 27 gastric cancers were examined ex vivo using confocal endomicroscopy. A fluorescent contrast agent, acriflavine, was applied topically to normal and to cancerous mucosa. In vivo imaging of the gastric mucosa after intravenous injection of fluorescein sodium was also performed in nine patients with gastritis or gastric cancer. RESULTS: The nuclear area in the ex vivo specimens was calculated using Scion Image software. The mean nuclear area of cancer cells was found to be significantly larger than that of normal cells in 18/27 gastric cancers (67 %). The mean nuclear area of the cancers tended to be larger than that of normal mucosa, especially in cases of differentiated adenocarcinoma. In more than half the cases, it was possible to diagnose malignancy automatically using confocal endomicroscopy and image-processing software without the need for biopsy and pathological examination. In vivo imaging of cancerous lesions showed irregularity in cellularity and vascularity. CONCLUSION: The ability of this imaging device to differentiate between normal tissue and cancerous tissues gives it potential value as a new screening tool for early detection of malignancy.

Adenocarcinoma↗
PubMed2006

Gastric mucin phenotype defines tumour progression and prognosis of intrahepatic cholangiocarcinoma: gastric foveolar type is associated with aggressive tumour behaviour.

AIMS: To identify the role of mucus core protein (MUC) in intrahepatic cholangiocarcinoma (ICC). METHODS AND RESULTS: We examined the expression profile of MUC2, MUC5AC and MUC6 by immunohistochemical staining in 100 ICCs and compared the clinicopathological factors and the immunohistochemical results. The expression frequency was: MUC2, 9%; MUC5AC, 40%; and MUC6, 21%. According to the gastric mucin expression profile, ICCs were classified into the following groups: null type (n = 43), gastric foveolar type (n = 36), pyloric gland type (n = 11) and gastric combined type (n = 10). Half of the gastric foveolar type and the gastric combined type were located in the hilar region, but the other types were predominant at the periphery (P = 0.0004). Well-differentiated components were more often detected in the gastric combined type and the pyloric gland type (P = 0.0281). The gastric foveolar type was associated with a higher incidence of lymph node metastasis (P < 0.0001). The pyloric gland type was associated with better survival and the gastric foveolar type was associated with worse survival. The gastric mucin phenotype was an independent prognostic factor by multivariate survival analysis. CONCLUSION: The gastric foveolar type of ICC was more often associated with aggressive tumour development, whereas the pyloric gland type exhibited less aggressive behaviour.

Adult↗
PubMed2006

Incidence of venous thromboembolism following major abdominal surgery: a multi-center, prospective epidemiological study in Japan.

BACKGROUND: Venous thromboembolism (VTE) has been considered to be a rare surgical complication in Japan. AIM: To investigate the incidence and risk factors of VTE in Japanese patients undergoing major abdominal surgery. METHODS: A prospective, multi-center epidemiological study was conducted from December, 2001 to August 2002 in 39 medical institutes throughout Japan. A total of 173 patients with general (n = 128), gynecologic (n = 23), and urologic (n = 22) surgery were analyzed. For the diagnosis of deep vein thrombosis (DVT), bilateral venography was performed in all patients. Lung ventilation/perfusion scintigraphy was carried out in patients suspected of pulmonary thromboembolism (PTE). RESULTS: There were 36 patients with distal DVT (20.8%) and five patients with proximal DVT (2.9%). One patient was diagnosed as PTE. Overall, VTE was diagnosed in 42 patients (24.3%). By univariate analysis, only age (60 years or older) was identified as a significant risk factor in the whole study population. When analyzed by the stepwise multiple logistic regression model, female gender, operation site, age, and operation time were four risk factors found to be significant. The incidence of VTE was closely related to the number of risk factors that patients had. As many as 44% of patients with three or four risk factors developed VTE while those with one or two risk factors showed about a 17% incidence of VTE. Four patients lacking any risk factors did not develop VTE. CONCLUSIONS: Venous thromboembolism is common in Japanese patients undergoing major abdominal surgery. Pharmacologic thromboprophylaxis is considered essential, particularly in those patients with multiple, potential risk factors.

Abdomen↗
PubMed2006

Feasibility of left lobe living donor liver transplantation between adults: an 8-year, single-center experience of 107 cases.

Operative mortality for a right lobe (RL) donor in adult living donor liver transplantation (LDLT) is estimated to be as high as 0.5-1%. To minimize the risk to the donor, left lobe (LL)-LDLT might be an ideal option in adult LDLT. The aim of the study was to assess the feasibility of LL-LDLT between adults based on a single-center experience of 107 LL-LDLTs performed over 8 years. The mean graft weight of LL grafts was 452 g, which amounted to 40.5% of the estimated standard liver volume of the recipients. The overall 1-, 3- and 5-year patient survival rates in LL-LDLT were 81.4, 76.9 and 74.7%, respectively, which were comparable to those of RL-LDLT. Twenty-six grafts (24.3%) were lost for various reasons with three losses directly attributable to small-for-size graft syndrome. Post-operative liver function and hospital stay in LL donors were significantly better and shorter than that in RL donors, while the incidence of donor morbidity was comparable between LL and RL donors. In conclusion, LL-LDLT was found to be a feasible option in adult-to-adult LDLT. Further utilization of LL grafts should be undertaken to keep the chance of donor morbidity and mortality minimal.

Adult↗
PubMed2005

Laparoscopic cholecystectomy using a newly developed laparoscope manipulator for 10 patients with cholelithiasis.

BACKGROUND: Laparoscopic surgery has continued to gain popularity in almost all fields of abdominal surgery, and robotic systems have been introduced in general surgery. Naviot is a new remote-controlled laparoscope manipulator system controlled by the operator's hand. This study assessed its introduction into clinical practice. METHODS: A group of 10 consecutive patients with cholelithiasis underwent laparoscopic cholecystectomy assisted by the Naviot system (Naviot group). Another group of 41 patients who underwent laparoscopic cholecystectomy with a conventional human camera holder (human camera group) were selected for a comparison of their operative results with those of the Naviot group. RESULTS: The operative time of 89.3 +/- 27.1 min for the Naviot group was significantly longer than that of 74.8 +/- 28.1 min for the human camera group (p < 0.05). However, when the setup time for the Naviot system was excluded, the operative time was not significantly different from that for the human camera group. Other operative results showed no significant difference between the two groups. CONCLUSIONS: The authors believe that the new Naviot system is feasible for clinical use, and that it enables surgeons to perform solo gastrointestinal surgery.

Aged↗
PubMed2005

Effective follow-up for recurrence or a second primary cancer in patients with early gastric cancer.

BACKGROUND: Patients with early gastric cancer have an excellent prognosis with low rates of recurrence, but may have an increased risk of developing a second primary cancer. Because the number of early gastric cancers has increased, clarification of both recurrences and second primary cancers is important for the development of effective postoperative follow-up programmes. METHODS: Data on 1070 patients with early gastric cancer were analysed retrospectively with respect to the clinicopathological features of both recurrence and second primary cancers after surgical treatment. RESULTS: Multivariate analysis showed that lymph node metastasis and older age were independent risk factors for recurrence of early gastric cancer. The incidence of second primary cancers was 5.0 per cent; lung and colorectal cancers were detected most frequently, followed by cancers in the oesophagus, breast and remnant stomach. CONCLUSION: Clinicopathological features of patients with early gastric cancer can be used to identify those most at risk of developing either recurrence or a second primary cancer.

Age Factors↗
PubMed2005

Living donor liver transplantation for hepatocellular carcinoma: a special reference to a preoperative des-gamma-carboxy prothrombin value.

BACKGROUND: Des-gamma-carboxy prothrombin (DCP) is a sensitive marker related to vascular invasion of hepatocellular carcinoma (HCC). The aim of this study was to clarify the risk factors of HCC recurrence in living donor liver transplantation (LDLT) with special reference to preoperative DCP values. METHODS: Forty consecutive adult HCC patients who underwent LDLT were examined for a correlation between the DCP value and vascular invasion. Risk factors for recurrence were also investigated using clinicopathological variables including preoperative DCP levels. RESULTS: The incidence of positive histological vascular invasion in patients with DCP values above 300 mAU/mL was higher than that with those with DCP value below 300 mAU/mL. Other significant risk factors for recurrence were over 5 cm tumor diameter, not meeting the Milan criteria, AFP value >400 ng/mL, histological vascular invasion, poorly differentiated histology, and male gender. Among the patients who did not meet the Milan criteria, those with both no more than 5 cm of tumor diameter and no more than 300 mAU/mL DCP exhibited a good prognosis. CONCLUSIONS: A high DCP value, namely >300 mAU/mL correlated with histological vascular invasion and was one of the strongest prognostic variables. Therefore, special attention should be paid to HCC patients with high DCP values. No correlation between the number of tumor nodules and recurrence was found; therefore, the Milan criteria may require revision regarding the number of tumor nodules.

Adult↗
PubMed2005

Loss of phenotypic expression is related to tumour progression in early gastric differentiated adenocarcinoma.

AIMS: To evaluate the relationship between phenotypic expression and tumour progression as represented by macroscopic features, submucosal invasion and lymph node metastasis in early differentiated gastric adenocarcinoma. METHODS: One hundred and fifty-five cases of early gastric differentiated adenocarcinoma without any poorly differentiated components were studied. The mucosal and submucosal components of carcinomas and lymph node metastatic lesions were classified into four categories, gastric type (G-type), incomplete intestinal type (I-type), complete intestinal type (C-type) and unclassified type (U-type), based on the combination of the phenotypic expression of HGM (gastric foveolar epithelium), MUC 6 (gastric pyloric glands), MUC 2 (intestinal goblet cells) and CD 10 (small intestinal brush border). In addition, a new classification representing a phenotypic shift from mucosa to submucosa or from primary lesion to lymph node metastasis was established with the categories of preserved group (P-group), loss group (L-group) and acquired group (A-group). RESULTS: (1) In submucosal carcinoma, U-type was more common in the submucosa (39%) than in the mucosa (9%). (2) U-type was more common in the metastatic lesions (42%) than in the primary lesions (5%). (3) The submucosal component and lymph node metastatic lesions were classified as P-group in 48% and 43% of cases, respectively, and as L-group in 50% and 52% of cases, respectively. (4) Lymph node metastatic lesions comprising undifferentiated carcinoma were classified as L-group in 100% of cases. CONCLUSION: During the course of tumour progression, early differentiated adenocarcinoma at first tends to lose its phenotypic expression despite preserving its morphology, but subsequently morphological dedifferentiation occurs.

Adenocarcinoma↗
PubMed2005

Two-field lymph-node dissection may be enough to treat patients with submucosal squamous cell carcinoma of the thoracic esophagus.

Significance of extended radical surgical treatment including three-field lymph node dissection for squamous cell carcinoma (SCC) of the esophagus remains debatable. The aim of the current study was to reconsider the merits and demerits obtained by three-field lymph node dissection for esophageal carcinoma and also to attempt to elucidate an appropriate surgical strategy for submucosal SCC of the thoracic esophagus. Thirty-one patients with SCC of the thoracic esophagus who had been treated with esophagectomy and two-field (thoracic and abdominal) lymph node dissection without preoperative therapies were enrolled. Five-year survival rate was 75.0% and the incidence proportion of postoperative complication was 9.7%. These data regarding postoperative outcome of patients were by no means inferior to those in the previous reports referring the prognosis of patients with esophageal carcinoma who had been treated with three-field lymph node dissection. Authors would like to mention that two-field lymph node dissection associated with reduced incidence of postoperative complications might be enough to treat the submucosal SCC of the thoracic esophagus.

Adult↗
PubMed2005

A case of esophageal small cell carcinoma with multiple liver metastases responding to chemotherapy with irinotecan plus cisplatin.

We report a case of small cell esophageal carcinoma (SCEC) with multiple liver metastases treated with some success by chemotherapy with irinotecan (CPT-11) plus cisplatin (CDDP). Radiologic and endoscopic examination of a 75-year-old man with multiple liver tumors disclosed a 4.0-cm type 2 tumor in the middle third of the esophagus. An endoscopically obtained biopsy specimen was diagnosed as undifferentiated small cell carcinoma. Multiple liver metastases were confirmed but lymph node metastases and distant metastases other than those in the liver were not detected. After six courses of chemotherapy with CPT-11 plus CDDP, the primary lesion showed complete response and liver metastases showed partial response. However, because all lesions almost immediately relapsed or progressed, arterial infusion chemotherapy for liver metastases and radiation for the primary lesion were given as second-line treatment. The primary lesion showed complete response with radiation. Arterial infusion chemotherapy prevented the progression of liver metastases once, but the patient died of liver failure at last. No distant lesions including metastatic lymph nodes were confirmed over the course of his illness, and the patient survived for a year after first diagnosis. Although the prognosis of SCEC is quite unfavorable due to highly aggressive behavior, a better prognosis is possible with effective chemotherapy and second-line treatment is important in improving prognosis.

Aged↗
PubMed2004

Relationship between intracellular localization of p34cdc2 protein and differentiation of esophageal squamous cell carcinoma.

PURPOSE: G2/M cyclins including cyclins A and B can exert their biologic functions of mitosis and proliferation of the tumor cells by being combined by protein kinase p34cdc2. The aim of the current study was to elucidate the clinicopathologic significance of immunohistochemical expression of p34(cdc2) in esophageal squamous cell carcinoma (ESCC), which has not been resolved. METHODS: Immunohistochemical expression of p34(cdc2) was examined for 91 cases of ESCC, and the relationship between the type of p34(cdc2) expression and the clinicopathologic features of the patients and tumors was analyzed. RESULTS: Forty-one ESCCs demonstrated cytoplasm dominant expression of p34(cdc2) and the other 50 ESCCs showed nuclei dominant p34(cdc2) expression. This differential expression pattern of p34(cdc2) did not reflect a prognostic aspect; however, the proportion of keratinizing tumors ESCCs with cytoplasm dominant expression of p34(cdc2) was significantly higher than that among ESCCs presenting nuclei-dominant p34(cdc2) expression (P=0.006). CONCLUSION: Cellular differentiation in squamous cell carcinoma of the esophagus may be mediated by an intracellular localization of p34(cdc2).

Aged↗
PubMed2004

Is graft size a major risk factor in living-donor adult liver transplantation?

Graft size is known to be a major risk factor in living donor adult liver transplantation (LDALT). The aim of this study is to reassess whether graft size is a critical factor in LDALT or not. A series of 75 LDALTs excluding auxiliary transplantation and ABO blood-type incompatible transplantation were analyzed. The patients were divided into two groups, according to graft volume (GV) and standard liver volume (SLV): group 1 (small-size group) (GV/SLV: <40%), and group 2 (non-small-size group) (> or =40%). Perioperative clinical data were compared between the two groups, including graft survival and postoperative complications. These parameters were also compared under the conditions of cirrhotic recipients. No difference in graft survival was found between the two groups. No difference was found in incidence of postoperative complications, such as intractable ascites and persistent hyperbilirubinemia. Even in cirrhotic patients with Child-Pugh's class C, there was no difference in graft survival between the two groups. Risk factors related to graft loss were a preoperative urgent status due to chronic liver disease, pre-operative hyperbilirubinemia of over 10 mg/dl, and ABO blood type of not identical but compatible combination between donor and recipient. Graft size is not always considered to be a major risk factor in LDALT, although the number of patients was small in this study. Therefore, a left-lobe graft, even a "small-for-size" graft for adult recipients, remains a feasible option in LDALT.

Adolescent↗
PubMed2004

Significance of immunohistochemical over-expression of CD44v6 as an indicator of malignant potential in esophageal squamous cell carcinoma.

PURPOSE: The aim of the current study was to find out a clinicopathologic significance of CD44v6 over-expression in esophageal squamous cell carcinoma (ESCC), which has not been elucidated fully. METHODS: Immunohistochemical expression of CD44v6 was examined for 81 ESCCs. Correlation of CD44 over-expression with the clinicopathologic features were investigated. RESULTS: Thirty-eight ESCCs (46.9%) had over-expression of CD44v6. The proportions of the incidence of lymph node metastasis (P=0.039), lymphatic permeation (P=0.003), and blood vessel invasion (P=0.037) in ESCCs with over-expression of CD44v6 were significantly higher than those in ESCCs without over-expression of CD44v6. The stage of the tumor in ESCCs with over-expression of CD44v6 was significantly more advanced (P=0.045). Survival rates of patients with ESCC with over-expression of CD44v6 were significantly worse (P=0.0005). Moreover, CD44v6 over-expression (P=0.048) as well as blood vessel invasion (P=0.014) and stage of the tumor ( P=0.010) were factors independently associated with the unfavorable prognosis of the patients with ESCC. CONCLUSIONS: Over-expression of CD44v6 can be an indicator of the malignant potential of ESCC.

Aged↗
PubMed2004

The hydroxyl radical scavenger MCI-186 protects the liver from experimental cold ischaemia-reperfusion injury.

BACKGROUND: Oxidative stress contributes to hepatic ischaemia-reperfusion (IR) injury in a biphasic pattern. In addition to direct cytotoxic effects, oxidative stress also initiates the signal transduction processes that promote second-phase liver injury. The present study investigated the effects of the hydroxyl radical scavenger MCI-186 on the biphasic process of hepatic cold IR injury. METHODS: After cold preservation for 16 h, rat livers were reperfused on an isolated liver perfusion system for 120 min with oxygenated Krebs-Henseleit bicarbonate buffer. Perfusate samples were obtained serially, and portal flow rates were also recorded. To determine whether MCI-186 affected cytokine levels that control the second-phase injury, levels of interleukin (IL) 10 and tumour necrosis factor (TNF) alpha were measured in the perfusate. RESULTS: Addition of MCI-186 1 mg/l into the perfusate significantly improved portal flow (P<0.050), hepatic enzyme release into the perfusate (P=0.038), total bile production (P=0.029) and malondialdehyde concentration (P=0.038). Furthermore, treatment with MCI-186 led to a substantial increase in IL-10 release (P=0.032). TNF-alpha levels were not affected. CONCLUSIONS: MCI-186, an agent ready for clinical use, appears to have direct and indirect protective effects against hepatic cold IR injury.

Animals↗
PubMed2004

S100 beta protein: the preoperative new clinical indicator of brain damage in patients with fulminant hepatic failure.

The aim of this study was to clarify the role of serum S100 beta on the accurate assessment of reversibility of brain damage after fulminant hepatic failure (FHF). Among the 13 patients with FHF enrolled in this study, 12 underwent living donor liver transplantation; one patient could not the procedure because of volvulus of the sigmoid colon. Serum S100 beta was serially measured using a chemiluminescent immunoassay. Preoperative serum S100 beta in patients with diffuse brain edema was significantly higher than that in patients with localized brain edema (P < 0.05). Patients with preoperative brain death showed serum S100 beta levels over 7.0 microg/L. Serum S100 beta levels correlated with the degree of brain edema of FHF. It has the potential to be a new clinical, noninvasive indicator of brain damage due to FHF.

Adult↗
PubMed2004

Renal artery clamping and left renal vein division during abdominal aortic aneurysm repair.

OBJECTIVES: To determine whether renal artery clamping and division of the left renal vein affects renal function in the patients who undergo repair of infrarenal abdominal aortic aneurysm (AAA). METHODS: Between 1992 and 2000, 267 patients had open surgery for infrarenal AAA. Of these, 22 (8%) required temporary bilateral (15) or unilateral (7) renal artery clamping. 8 also had the left renal vein divided, three of which were re-anastomosed. RESULTS: Renal artery clamping and/or renal vein divisions did not affect the incidence of complications and long term renal failure. CONCLUSIONS: Clamping of the renal arteries and/or renal vein division during AAA surgery does not in itself compromise short or long term renal function.

Aged↗