Kazuhito Oka

DNA damage signaling is activated during cancer progression in human colorectal carcinoma

Purpose: Recent studies have shown that the DNA damage response (DDR) is activated in precancerous lesions, suggesting that neoplastic cells may avoid apoptosis by impairing the DDR which acts as a barrier against tumor progression. To define the role of the DDR pathway in human colorectal carcinoma, we investigated the level of phosphorylated proteins of the DDR pathway. Experimental Design: Colorectal tissue samples were obtained at the time of surgery, from 55 patients at two hospitals. The tissues were classified into four groups according to pathology: normal mucosa, adenoma, early carcinoma and advanced carcinoma. We evaluated phosphorylated ataxia telangiectasia mutated (pATM), phosphorylated H2AX (γH2AX) and Chk2 (pChk2) protein levels by immunohistochemistry and Western blot analysis. We also evaluated apoptosis by the TUNEL assay. Results: Immunostaining for pATM, γH2AX and pChk2 revealed that all were significantly expressed during tumor progression in advanced carcinoma (vs. normal tissue for pATM [p

Laparoscopic resection of an ileal lipoma : Report of a case

A 63-year-old woman was admitted to our hospital for investigation of upper abdominal pain and vomiting. Ultrasonography (US) showed a hyperechoic mass in the right lower abdomen, and computed tomography (CT) showed a low-density mass and intestinal invagination. Thus, we made a diagnosis of intestinal lipoma with intussusception and performed laparoscopic partial resection of the ileum, including the tumor. The resected specimen contained a round tumor, 25 × 22 × 20 mm, which was identified as an intestinal lipoma histopathologically. Our experience supports earlier reports that US and CT are effective tools in the diagnosis of bowel lipoma. Laparoscopic surgery is the treatment of choice for benign tumors of the small intestine because it is minimally invasive, with cosmetic, physical, and economic benefits.

Laparoscopic cecopexy for mobile cecum syndrome manifesting as cecal volvulus: Report of a case

A 44-year-old woman was admitted to our hospital for investigation and treatment of sudden abdominal pain and distention. Plain abdominal radiography and abdominal computed tomography (CT) findings were suggestive of sigmoid volvulus. She underwent an emergency colonoscopy, and the scope passed easily through the sigmoid colon and reached the ascending colon quickly. However, stenosis with concentricity of the fold was observed in the cecum, which was shifted upward and to the left. Based on these findings, we diagnosed cecal volvulus caused by mobile cecum syndrome. The patient’s symptoms resolved quickly after colonoscopic reduction and elective laparoscopic surgery was performed 18 days after admission. Perioperative examination revealed a mobile cecum caused by an elongated ascending colon. We sutured the cecum and ascending colon to the lateral peritoneum laparoscopically with interrupted sutures. The patient recovered well and was discharged on postoperative day 7. An unfixed intestine can be detected easily during laparoscopic surgery, which is minimally invasive and cosmetically, physically, and economically beneficial. Thus, we recommend laparoscopic cecopexy for mobile cecum syndrome.

Early laparoscopic cholecystectomy for acute gangrenous cholecystitis.

Treatment of severe acute cholecystitis by laparoscopic cholecystectomy remains controversial because of technical difficulties and high rates of complications and conversion to open cholecystectomy. We investigated whether early laparoscopic cholecystectomy is appropriate for acute gangrenous cholecystitis. Pathologic diagnoses and outcomes were analyzed in patients who underwent laparoscopic or open cholecystectomy at our hospital, January 2002 to September 2005. Of 30 patients with acute gangrenous cholecystitis, 16 underwent early laparoscopic cholecystectomy, 10 underwent open cholecystectomy, and 4 were converted to open cholecystectomy (conversion rate, 20.0%). There was no significant difference in operation time or intraoperative bleeding. The requirement for postoperative analgesics was significantly lower (6.4±7.3 vs. 1.5±1.2 doses, P<0.05) and hospital stay significantly shorter (8.6±2.1 vs. 15.6±6.3 d, P<0.01) after laparoscopic cholecystectomy. There were no postoperative complications in either group. Thus, early laparoscopic cholecystectomy seems appropriate for acute gangrenous cholecystitis. Conversion to open cholecystectomy may be required in difficult cases with complications.

Loss of skeletal muscle mass after curative gastrectomy is a poor prognostic factor

Sarcopenia has been reported to relate to poor prognosis in various malignant cancer types. The present study aimed to clarify the prognostic impact of skeletal muscle mass (SMM) loss after curative gastrectomy in patients with gastric cancer. A total of 119 patients who underwent curative gastrectomy for gastric cancer between 2009 and 2016 were analyzed. The SMM loss at 6 months postoperatively compared with the SMM prior to surgery was calculated using the hospital records. The median loss of SMM was 3.8%. Multivariate logistic regression analysis demonstrated that total gastrectomy was a significant and independent risk factor for SMM loss of ≥5% (odds ratio=2.58; P=0.02). Results from multivariate analysis using stepwise Cox proportional hazards regression indicated that the following factors were significantly associated with shorter overall survival after curative gastrectomy: Age [>70 years; hazard ratio (HR)=2.46, P=0.04], TNM stage (≥2; HR=2.65, P=0.04) and loss of SMM (≥5%; HR=2.57, P=0.03). The present findings suggested that loss of SMM after curative gastrectomy for gastric cancer is an independent predictive factor for poor prognosis.