These results suggest that LA for perforated appendicitis is a safe procedure that may prove to have significant clinical advantages over conventional surgery.

Extrahepatic cholestasis often evokes liver injury with hepatocyte apoptosis, aberrant cytokine production, and-most importantly-postoperative septic complications. To clarify the involvement of aberrant cytokine production and hepatocyte apoptosis in impaired resistance to bacterial infection in obstructive cholestasis, C57BL/6 mice or Fas-mutated lpr mice were inoculated intraperitoneally with 10 7 colony-forming units of Escherichia coli 5 days after bile duct ligation (BDL) or sham celiotomy. Cytokine levels in sera, liver, and immune cells were assessed via enzyme-linked immunosorbent assay or real-time reverse-transcriptase polymerase chain reaction. BDL mice showed delayed clearance of E. coli in peritoneal cavity, liver, and spleen. Significantly higher levels of serum interleukin (IL) 10 with lower levels of IL-12p40 were observed in BDL mice following E. coli infection. Interferon ␥ production from liver lymphocytes in BDL mice was not increased after E. coli infection either at the transcriptional or protein level. Kupffer cells from BDL mice produced low levels of IL-12p40 and high levels of IL-10 in vitro in response to lipopolysaccharide derived from E. coli. In vivo administration of anti-IL-10 monoclonal antibody ameliorated the course of E. coli infection in BDL mice. Furthermore, BDL-lpr mice did not exhibit impairment in E. coli killing in association with little hepatic injury and a small amount of IL-10 production. In conclusion, increased IL-10 and reciprocally suppressed IL-12 production by Kupffer cells are responsible for deteriorated resistance to bacterial infection in BDL mice. Fasmediated hepatocyte apoptosis in cholestasis may be involved in the predominant IL-10 production by Kupffer cells. (HEPATOLOGY 2004;40:414 -423.)

Interleukin (IL)-15, a potent inhibitor of tumor necrosis factor (TNF)-alpha-mediated apoptosis, causes multiple organ failure during endotoxic shock. We investigated the potential role of IL-15 in protection against Escherichia coli-induced shock by using IL-15 transgenic (Tg) mice. These mice were resistant to an otherwise lethal challenge with E. coli, although bacterial burden and serum levels of TNF-alpha were similar in non-Tg mice. Apoptosis in cells of the peritoneal cavity, liver, spleen, or lung was significantly suppressed in IL-15 Tg mice after E. coli infection. Peritoneal cells from naive IL-15 Tg mice were also resistant to TNF-alpha-induced apoptosis in vitro, and neutralization of endogenous IL-15 significantly aggravated TNF-alpha-induced apoptosis. Exogenous IL-15 prevented TNF-alpha-induced apoptosis in normal mice in vitro and improved the survival rate after E. coli challenge. These results suggest that IL-15 overexpression can prevent TNF-alpha-induced apoptosis and protect against E. coli-induced shock, indicating a possible therapeutic application of IL-15 for septic shock.

Although fluorine-18 deoxyglucose-positron emission tomography (FDG-PET) is a sensitive diagnostic modality in detecting malignant tumors, differential diagnosis of malignant tumors from inflammatory lesion is challenging. We experienced a case of acute degenerative necrosis superimposed on chronic pancreatitis, which was difficult to distinguish from pancreatic cancer. The patient was a 66-year-old man with a complaint of upper abdominal pain. Abdominal computed tomography revealed low-density masses in the head and body of the pancreas. FDG-PET revealed intense accumulations at the head and body of the pancreas (mean standard uptake value for the head and body pancreatic tumors was 4.1 and 6.7, respectively) corresponding to the 2 tumors detected by computed tomography. Because of a possible malignant pancreatic tumor, the patient underwent pylorus-preserving pancreatoduodenectomy. Histologic examination of the resected specimen revealed a characteristic of chronic pancreatitis in a nontumorous area. Two tumors detected by FDG-PET consisted of degenerative necrosis surrounded by granulation tissue. The amount of granulation tissue was correlated to the levels of standard uptake value. No malignant tumors were observed. This case suggests a limitation of FDG-PET in distinguishing malignant neoplastic lesions in the pancreas, especially from acute degenerative changes in chronic pancreatitis. Repetitive PET examination is recommended for the accurate diagnosis.

Fas ligand (Fas L) expression was induced on intrahepatic NK1.1 + T cells in vivo after an intraperitoneal inoculation of Escherichia coli. Liver injury after E. coli infection, as assessed by serum GPT level and histological examination, was significantly reduced in J § 281 -/-mice lacking NK1.1 + T cells or in gld/gld mice bearing mutated Fas L, indicating that NK T cells at least partly contribute to E. coli-induced liver injury in a Fas/Fas L-dependent manner. Bacterial numbers in organs and cytokine levels in serum of J § 281 -/-mice did not differ from those of J § 281 +/+ mice following E. coli infection. Intrahepatic NK1.1 + T cells, which preferentially expressed Toll-like receptor 2 (TLR2) mRNA, responded in vitro to synthetic lipoprotein, a ligand for TLR2, by inducing Fas L expression on their surface. In a manner analogous to E. coli infection, lipoprotein and LPS could additively induce Fas L expression on NK1.1 + T cells, leading to liver injury in vivo in normal mice but not in gld/gld mice. In conclusion, it is suggested that induction of Fas L on NK T cells in response to bacterial components such as lipoproteins plays an important role in pathogenesis of E. coli-induced liver injury in mice.