Naoto Senmaru

Suppression of Erk activation and in vivo growth in esophageal cancer cells by the dominant negative Ras mutant, N116Y.

Our previous studies demonstrated that introduction of a dominant negative H‐ras mutant, N116Y, inhibits the growth of various types of cancer cells in vitro. In this study, we tested the efficacy of N116Y in blocking the growth of esophageal cancer cells using an adenoviral vector. Infection with N116Y adenovirus, (AdCMV‐N116Y), in which N116Y expression is driven by the cytomegalovirus promoter, significantly reduced the in vitro growth of all esophageal cancer cell lines studied. Esophageal cancer cells that contained wild‐type K‐ras and H‐ras (TE8, SGF3, SGF7) were more sensitive to AdCMV‐N116Y than HEC46 cells that expressed mutant K‐ras protein. Most importantly, direct injection of AdCMV‐N116Y into TE8‐ or SGF3‐induced tumors in nude mice suppressed their growth significantly. To examine the suppressive mechanism of N116Y, cell cycle profile and the activation of extracellular signal‐regulated kinase 2 (Erk2) were examined by flow cytometry and Western blot analysis, respectively. In TE8 cells, progression into S phase was clearly blocked after infection with AdCMV‐N116Y. Infection with AdCMV‐N116Y did not strongly suppress the activation of Erk2 after EGF stimulation in serum‐starved HEC46 cells, whereas it completely suppressed activation in TE8, SGF3 and SGF7 cells. Our observations suggest that N116Y reduces growth of human esophageal cancer cells and suppresses the activation of Erk2; they also indicate that N116Y is a potential candidate gene for human esophageal cancer gene therapy. Int. J. Cancer 78:366–371, 1998.© 1998 Wiley‐Liss, Inc.

Adult Intussusception Due to Enteric Neoplasms

Adult intussusception is an infrequent disease and the cause of intussusception differs between children and adults [1–3]. Many of the cases in adults are secondary to an underlying lesion and adult intussusception of the colon is most often secondary to a malignant tumor. There are no typical complaints, signs, or symptoms often associated with the chronic process of bowel obstruction. The diagnosis of adult intussusception is usually made by preoperative radiological and endoscopic examinations, or during laparotomy. Surgical resection or operative reintegration is required. The aim of this study was to retrospectively evaluate the preoperative diagnoses and surgical treatments of patients with adult intussusception in our hospital.

Ischemic stricture of the small intestine associated with acute pancreatitis

SummaryA 37-yr-old man underwent an open drainage operation for severe acute pancreatitis and received respiratory ventilation support for 4 mo because of respiratory failure based on disseminated intravascular coagulation (DIC) and septic shock. Under intensive care, he sometimes had bloody diarrhea for about 6 wk. Colonoscopic findings suggested that the bleeding had derived from the small intestine. The patient then gradually recovered from acute pancreatitis and was discharged from the hospital. Thereafter, he suffered relapses of ileus and his symptoms progressively worsened. The patient underwent a second operation about 2 yr after the onset of acute pancreatitis. At celiotomy, multiple stenoses of the distal ileum measuring about 60 cm in length were found and the segment was resected. The resected specimen demonstrated six separate circumferential strictures and shallow ulcerations. Histologically, multiple ulcerations were restricted to the mucosa and were accompanied by marked submucosal edema and fibrosis. The mucosa between the ulcers revealed chronic regenerative changes: intimal thickening of small mesenteric arteries causing luminal narrowing and organized thrombosis in small mesenteric veins. Therefore, these were considered to be a series of segmental ischemic lesions. Note that delayed ischemic stricture of the small intestine may occur as a chronic complication of acute pancreatitis.

Risk Factors for Difficult Laparoscopic Cholecystectomy in Acute Cholecystitis

Background and Objectives: Factors that contribute to difficult laparoscopic cholecystectomy (LC) in acute cholecystitis (AC) that would affect the performance of early surgery remain unclear. The purpose of this study was to identify such risk factors. Methods: One hundred fifty-four patients who underwent LC for AC were retrospectively analyzed. The patients were categorized into early surgery and delayed surgery. Factors predicting difficult LC were analyzed for each group. The operation time, bleeding, and cases of difficult laparoscopic surgery (CDLS)/conversion rate were analyzed as an index of difficulty. Analyses of patients in the early group were especially focused on 3 consecutive histopathological phases: edematous cholecystitis (E), necrotizing cholecystitis (N), suppurative/subacute cholecystitis (S). Results: In the early group, the CDLS/conversion rate was highest in necrotizing cholecystitis. Its rate was significantly higher than that of the other 2 histopathological types (N 27.9% vs E and S 7.4%; P = .037). In the delayed-surgery group, a higher white blood cell (WBC) count and older age showed significant correlations with the CDLS/conversion rate (P = .034 and P = .004). Conclusion: In early surgery, histopathologic necrotizing cholecystitis is a risk factor for difficult LC in AC. A higher WBC count and older age are risk factors for delayed surgery.

Long-term Survival after Local Recurrence from Gastric Cancer: Report of a Case

症例は63歳の男性で, 1994年8月3日胃癌に対して幽門側胃切除術を施行した. 総合所見は中分化型腺癌, fT1 (SM), N1, H0, P0, M0, fStage IBであった. 1996年7 月の腹部CT で胃十二指腸吻合部から膵頭部前面にかけて腫瘤を認め, その後徐々に増大傾向を示したが他部位に再発巣を認めず1997年11月6日膵頭十二指腸切除術を施行した. 腫瘤は胃十二指腸吻合部から膵頭部にかけて一塊となっており膵との境界は不明瞭で剥離困難であった. 病理学的検査で胃癌の局所再発と判定された. 再発切除後6年6か月経過した現在, 再発徴候なく健在である. 本例は再発胃癌に対して膵頭十二指腸切除術を施行し長期生存が得られたまれな症例と考え若干の文献的考察を加え報告した.