Kengo Kanetaka

Overexpression of osteopontin in hepatocellular carcinoma.

Human hepatocellular carcinoma (HCC) is one of the most common and aggressive malignancies. In order to identify genes involved in HCC progression, we conducted a differential display analysis and found osteopontin (OPN) to be overexpressed in HCC. OPN is known to be a secreted adhesive glycoprotein, associated with tumorigenesis and metastasis in several cancers. Quantitative polymerase chain reaction analysis of 30 HCC cases revealed the average ratio of OPN to glyceraldehyde‐3‐phosphate dehydrogenase in tumors to be significantly higher than that in the surrounding non‐cancerous liver (4.7 ± 1.6 vs 0.18 ± 0.04, P = 0.0072). Immunohistochemistry confirmed the OPN protein was expressed mainly on cancer cells, and was positive in 12 of 30 HCC, most of which showed transcript overexpression. Both OPN transcript and OPN protein were significantly overexpressed in HCC with capsular infiltration, compared with HCC without capsular infiltration. Moreover, OPN‐positive cancer cells were often dispersed in the periphery of cancer nodules and were adjacent to stromal cells. Although OPN overexpression was not related to vascular invasion or intrahepatic metastasis, OPN was suggested to play a role in HCC, especially in cancer–stromal interactions.

Orthotopic Transplantation Models of Pancreatic Adenocarcinoma Derived From Cell Lines and Primary Tumors and Displaying Varying Metastatic Activity

Objective: To establish a series of clinically relevant orthotopic transplantation models of human pancreatic adenocarcinoma from both cell lines and primary tumors under uniform experimental conditions. Methods: Ten pancreatic cancer cell lines and 12 primary tumors were orthotopically transplanted in SCID mice. The cell lines and xenografts were characterized for K-ras, BRAF, p53, p16, and DPC4 aberrations employing direct sequencing, immunohistochemistry, and Western blotting. Results: All xenografts showed high intrapancreatic tumorigenicity and extensive local tumor growth, and each showed a unique behavioral and genetic profile. Tumor characteristics were retained during serial passaging. The cell line–derived xenografts represented the entire expected range of histologic differentiation. Although the overall metastatic rate was moderate to high, the metastatic pattern varied; 4 cell lines showed a high metastatic rate to the liver. The primary tumor–derived xenografts retained their similarity to the corresponding original donor tumors with regard to histologic presentation and biologic behavior. K-ras, p53, p16, and DPC4 aberrations were revealed in 80%, 70%, 50%, and 40% of cell lines and 100%, 33%, 75%, and 58% of primary tumor derived xenografts, respectively. No BRAF mutations were present. The metastatic behavior of the xenografts was significantly associated with the degree of histologic differentiation, number of genes altered, and p53 status. Conclusions: The new models reflected the wide range of patho-biological features and genetic alterations that characterize human pancreatic cancer and may be used collectively or selectively as a markedly improved in vivo tool for preclinical and molecular studies of pancreatic cancer.

Overexpression of tetraspanin CO-029 in hepatocellular carcinoma

BACKGROUND/AIMS The molecules involved in the progression of hepatocellular carcinoma (HCC) are not fully understood. The aim of this study was to elucidate the crucial genes involved in cancer progression and metastasis. METHODS Selectively expressed genes were screened using differential display analysis, and then further analyzed by real-time quantitative reverse-transcription polymerase chain reaction (RT-PCR) and immunohistochemistry. RESULTS Tetraspanin CO-029 was found to be frequently and significantly overexpressed in HCC. Real-time quantitative RT-PCR showed that the CO-029 mRNA level was 1.7 times higher (P=0.030) in cancerous tissues than in non-cancerous tissues. mRNA expression of the other tetraspanins, CD9 and CD82, was downregulated in HCC, especially in tumors with intrahepatic spreading (portal vein invasion and/or intrahepatic metastasis). In contrast, mRNA expression of CO-029 tended to be increased in cancerous tissue showing intrahepatic spreading compared with tumors without such spreading. Immunohistochemical analysis revealed that CO-029 was overexpressed in poorly differentiated HCCs compared with well to moderately differentiated tumors (P<0.001), and in HCCs showing intrahepatic spreading compared with those without spreading (P=0.019). CONCLUSIONS Our findings suggest that CO-029 has some roles in the promotion of metastasis of HCC.

Possible involvement of tetraspanin CO-029 in hematogenous intrahepatic metastasis of liver cancer cells.

Background and Aim:  A correlation between overexpression of tetraspanin CO‐029 and the intrahepatic spread of hepatocellular carcinoma (HCC) has been observed in surgically resected specimens from humans. However, the cellular mechanisms involved in CO‐029 protein modulation of the metastatic phenotype are unknown. In the present study, CO‐029 cDNA was stably transfected into a non‐metastatic human HCC cell line to investigate whether it could directly promote metastasis.

An Unusual Perforation of the Colon : Report of Two Cases

Abstract.We herein present two cases of a colorectal perforation due to uncommon reasons. First, we treated a 45-year-old woman for a stercoral perforation of the sigmoid colon. The pathognomonic etiology was a barium fecaloma originating from an upper gastrointestinal series 9 months before admission. The second case was a 46-year-old woman who was admitted with a perforation of the transverse colon. She had experienced perforations of the sigmoid colon at 32 years of age and of the rectum at 44 years of age, respectively. The second and third conditions were diagnosed to be idiopathic, and were histologically proven by an abrupt obliteration and a thinness of the colonic wall with some infiltration of inflammatory cells. The first condition, however, was most likely a stercoral perforation. The postoperative course of these patients was uneventful, and both are doing well at this writing.

Efficacy of Multilayered Hepatocyte Sheet Transplantation for Radiation-Induced Liver Damage and Partial Hepatectomy in a Rat Model

Although cell sheet technology has recently been developed for use in both animal experiments and in the clinical setting, it remains unclear whether transplanted hepatocyte sheets improve the liver function in vivo. Radiation-induced liver damage (RILD) combined with partial hepatectomy (PH) has been reported to suppress the proliferation of host hepatocytes and induce critical liver failure. The aim of this study was to improve the liver function in the above-mentioned diseased rat model (RILD + PH) using multilayered hepatocyte sheet transplantation. In this study, we used Fischer rats as a donor for primary hepatocytes and dermal fibroblast isolation. Cocultured multilayered hepatocyte sheets were generated by disseminating hepatocytes onto fibroblasts cultured beforehand on temperature-responsive culture dishes. Four cell sheets were transplanted into the recipient rats subcutaneously. Prior to transplantation, RILD (50 Gy) with 2/3PH was induced in the recipients. The same model was applied in the control group without transplantation. The serum was collected each week. The rats in both groups were sacrificed at 2 months after transplantation for the histological analysis. Consequently, the serum albumin concentrations were significantly higher in the transplant group than in the control group (54.3 ± 9.6 vs. 32.7 ± 5.7 mg/ml; p < 0.01) after 2 months and comparable to the serum albumin levels in the normal rats (58.1 ± 6.4 mg/ml). In addition, treatment with the transplanted sheets significantly improved the survival rate (57% vs. 22%, p < 0.05), and the hepatocyte sheets showed the storage of albumin, glycogen, and bile canaliculus structures. Some hepatocytes and fibroblasts were positive for Ki-67, and vascularization was observed around the cell sheets. Transplanted multilayered hepatocyte sheets can survive with additional proliferative activity, thereby maintaining the liver function in vivo for at least 2 months, providing metabolic support for rats with RILD.

Successful laparoscopic repair of a lumbar hernia occurring after iliac bone harvest.

Introduction Many techniques have been described for the surgical repair of lumbar hernias, including primary repair, local tissue flaps, and conventional mesh repair. All these open techniques require a large incision plus extensive dissection to expose the hernia ring. This report presents a case of a recurrent lumbar hernia, which was successfully repaired using a laparoscopic approach. Case Report A 75-year-old female presented with a symptomatic right lumbar hernia, 1-year after an iliac bone harvest for knee surgery. Under general anesthesia, the patient was placed in a lateral decubitus position. A 3 trocar technique was used to do adhesiolysis of the surrounding tissues, to provide an ample working space to identify the hernia. A composix dual mesh (bard) was tailored so that it would overlap the defect with intermittent fixation by a spiral tacker (protac). No hernia recurrence occurred over 2 years after surgery. Conclusion The laparoscopic approach has significant advantages for the repair a lumbar hernia: it enables the exact localization of the anatomic defect, and the mesh can be placed deep into the defect, thus allowing the intraabdominal pressure to hold it in position.

Gastric Necrosis After an Infarction of the Spleen : Report of a Case

Gastric necrosis is a rare and often fatal condition. A few reports of gastric necrosis of various etiologies have been published in the literature. This report deals with a case in which gastric necrosis and perforation occurred several years after an infarction of the spleen. Preoperative computed tomography showed the existence of splenic vein thrombosis accompanying splenic infarction. A laparotomy revealed an 8-cm-long laceration with ragged margins in the posterior of the stomach along the greater curvature. Furthermore, massive venous thrombosis was found in the major omentum. As a result, the reduced arterial blood supply and insufficient venous drainage due to splenic venous thrombosis may have together played a major role in the development of gastric necrosis.

A novel animal model of long-term sustainable anal sphincter dysfunction

BACKGROUND Although intersphincteric resection can avoid the need for permanent colostomy in patients with lower rectal cancer, it sometimes causes anal sphincter dysfunction, thus resulting in a lifelong, debilitating disorder due to incontinence of solid and liquid stool. The development of regenerative medicine could improve this condition by regenerating impaired anal muscle. In order to prove this hypothesis, preliminary experiments in animals will be indispensable; however, an adequate animal model is currently lacking. The purpose of this study was to establish a novel animal model with long-term sustainable anal sphincter dysfunction. MATERIALS AND METHODS Twenty male Sprague-Dawley rats were allocated into sham operation (n = 10) and anal sphincter resection (ASR) (n = 10) groups. The ASR group underwent removal of the left half of both the internal and external anal sphincters. Both groups were evaluated for anal function by measuring their resting pressure before surgery and on postoperative day (POD) 1, 7, 14, and 28. RESULTS The rats in the sham operation group recovered their anal pressure up to baseline on POD 7. The rats in the ASR group showed a significant decrease in anal pressure on POD 1 (P < 0.0001) compared with the baseline, and kept this low pressure until POD 28 (P < 0.0001). The defect of the anal sphincter muscle was confirmed histologically in the ASR group on POD 28. CONCLUSIONS The present novel model exhibits continuous anal sphincter dysfunction for at least 1 mo and may contribute to further studies evaluating the efficacy of therapies such as regenerative medicine.

Prediction and management of a low-lying costal arch which restricts the operative working space during laparoscopic cholecystectomy.

Background/purposeLaparoscopic cholecystectomy is difficult to perform in patients with a low-lying costal arch that entirely covers the liver. We conducted this study to clarify the factors related to a low-lying costal arch and establish countermeasures to circumvent this characteristic.MethodsThe study included 103 consecutive patients who underwent a laparoscopic cholecystectomy. The possible clinical factors associated with a low-lying costal arch restricting the operative working space were analyzed. The position of the liver against the costal arch and the presumed surgical visual angle for laparoscopic cholecystectomy, comprising the hepatic porta, umbilicus, and costal arch, were estimated with abdominal multidetector computed tomography (MDCT).ResultsSeven (7%) patients had a low-lying costal arch presenting an inadequate exposure of Calot’s triangle and restricted instrument mobility during laparoscopic cholecystectomy, and three patients required conversion to a laparotomy. A low-lying costal arch was significantly associated with advanced age, shorter stature, lighter body weight, coexisting kyphoscoliosis, gallbladder pathology, laparotomy conversion, and most of all, the liver edge lying above the costal arch and a narrow surgical visual angle upon MDCT. Of the seven patients with a critical low-lying costal arch, four underwent a successful laparoscopic cholecystectomy, this being done by lifting the right costal arch to create a workable surgical field; the rib-lifting procedure was planned as part of the scheduled procedure in the other three patients because the preoperative MDCT examination indicated a poor working space for a laparoscopic cholecystectomy.ConclusionsA low-lying costal arch is a substantial risk factor for conversion to a laparotomy when performing a laparoscopic cholecystectomy. However, the operative difficulty related to a low-lying costal arch can be predicted by using preoperative MDCT images and can be managed with proper planning and the appropriate use of the rib-lifting technique.