Association between hepatitis B or hepatitis C virus infection and risk of pancreatic adenocarcinoma development: a systematic review and meta-analysis.

BACKGROUND: Pancreatic adenocarcinoma (PAC) is an aggressive cancer with a poor prognosis. To date, PAC causes are still largely unknown. Antigens and replicative sequences of oncogenic hepatitis B (HBV) and hepatitis C (HCV) virus were detected in different extra-hepatic tissues, including pancreas. OBJECTIVE: a systematic review and meta-analysis of epidemiological studies assessing PAC risk in patients with HBV/HCV chronic infections. METHODS: In September 2012, we extracted the articles published in Medline, Embase and the Cochrane Library, using the following search terms: "chronic HBV" and "HCV", "hepatitis", "PAC", "risk factors", "epidemiology". Only case/control (C/C), prospective/retrospective cohort studies (PCS/RCS) written in English were collected. RESULTS: four hospital-based C/C studies and one PCS, in HBV-infected patients and two hospital-based C/C studies and one RCS in HCV-infected subjects met inclusion criteria. In these studies HBsAg positivity enhanced significantly PAC risk (RR = 1.18, 95% CI:1.04-1.33), whereas HBeAg positivity (RR = 1.31, 95% CI:0.85-2.02) as well as HBsAg negative/HBcAb positive/HBsAb positive pattern (RR = 1.12, 95% CI:0.78-1.59) and HBsAg negative/HBcAb positive/HBsAb negative pattern (RR = 1.30, 95% CI:0.93-1.84) did not. Relationship between PAC risk and anti-HCV positivity was not significant, although it reached a borderline value (RR = 1.160, 95% CI:0.99-1.3). CONCLUSIONS: HBV/HCV infection may represent a risk factor for PAC, but the small number of available researches, involving mainly populations of Asian ethnicity and the substantial variation between different geographical areas in seroprevalence of HBV/HCV-antigens/antibodies and genotypes are limiting factors to present meta-analysis.

Prognostic factors in periampullary and pancreatic tumor resection in elderly patients.

BACKGROUND: More than half of all patients with pancreatic adenocarcinoma are over 70 years of age. Life expectancy for the elderly population is increasing and currently major pancreatic resection provides the only meaningful chance of cure for periampullary and pancreatic tumors. Controversy over what constitutes the correct treatment of these tumors in elderly patients continues to this day. The aim of our study was to determine whether age alone or age plus some prognostic factors constitute contraindications to major pancreatic resections. METHODS: Between 2000 and 2005, data from 88 consecutive patients who had major pancreatic resection for periampullary or pancreatic tumors were entered into a prospective database. Fifty-three patients under 70 years of age (young patients), and 35 patients 70 years of age or older (elderly patients) were compared with respect to several characteristics and the postoperative course. RESULTS: Postoperative mortality and morbidity, length of hospital stay, and long-term survival were similar in the two groups. In the elderly group, the mortality rate was significantly higher in patients with chronic obstructive pulmonary disease (COPD), and the morbidity rate was significantly higher in patients with ASA 3 than in patients with ASA 1-2, in whom a pancreaticoduodenectomy or total pancreatectomy had been performed. CONCLUSIONS: Age alone is not a contraindication for major pancreatic resection. In elderly patients a careful evaluation of the co-morbidities and of the type of surgical procedure is mandatory in order to allow the proper selection of those patients best suited for surgery in specialized centers.

Parasite-altered behavior in a crustacean intermediate host: field and laboratory studies.

The effects of the acanthocephalan parasite Pomphorhynchus laevis on the behavior of its crustacean intermediate host, the amphipod Echinogammarus stammeri, were studied. A drift study revealed that infected amphipods were disproportionately represented in drift samples taken throughout a 24-hr period; infection with more than 1 parasite enhanced this effect. Infection also interacted with the daily timing of drift, with parasitized amphipods beginning to drift earlier in the evening. Two distinct behaviors quantified in laboratory settings may play a role in this increased drifting behavior: parasitized amphipods showed (1) an increased preference for an illuminated environment and (2) increased activity in comparison to nonparasitized conspecifics. These results are consistent with previous studies on the effects of P. laevis on another amphipod host, Gammarus pulex, and provide new data on the activity level of P. laevis-infected amphipods.

Occurrence of Acanthocephalus clavula (Acanthocephala) in Echinogammarus pungens (Amphipoda) from the River Adige.

Cystacanths of Acanthocephalus clavula Dujardin 1845 (Acanthocephala) were found in the hemocoels of naturally infected Echinogrammarus pungens M. Edwards 1840 (Amphipoda). Crustaceans were collected in Porto Frossone, an estuarine locality of the River Adige. Only 3 out of 562 E. pungens specimens were infected by A. clavula cystacanths; the larvae were enclosed in a thin acellular envelope. Infected amphipods were all females, and their total length was greater than that of uninfected females. Moreover, adult specimens of this acanthocephalan were found in the alimentary tract of Anguilla anguilla (L.) eels sampled in the crustacean collecting site. A description of cystacanths and their stages of development is reported here.