Case-control studies of sporadic enteric infections: a review and discussion of studies conducted internationally from 1990 to 2009

Epidemiologists have used case-control studies to investigate enteric disease outbreaks for many decades. Increasingly, case-control studies are also used to investigate risk factors for sporadic (not outbreak-associated) disease. While the same basic approach is used, there are important differences between outbreak and sporadic disease settings that need to be considered in the design and implementation of the case-control study for sporadic disease. Through the International Collaboration on Enteric Disease "Burden of Illness" Studies (the International Collaboration), we reviewed 79 case-control studies of sporadic enteric infections caused by nine pathogens that were conducted in 22 countries and published from 1990 through to 2009. We highlight important methodological and study design issues (including case definition, control selection, and exposure assessment) and discuss how approaches to the study of sporadic enteric disease have changed over the last 20 years (e.g., making use of more sensitive case definitions, databases of controls, and computer-assisted interviewing). As our understanding of sporadic enteric infections grows, methods and topics for case-control studies are expected to continue to evolve; for example, advances in understanding of the role of immunity can be used to improve control selection, the apparent protective effects of certain foods can be further explored, and case-control studies can be used to provide population-based measures of the burden of disease.     

Pathological findings and oncological control afforded by radical prostatectomy in men with high-risk prostate cancer: a single-centre study

Objective  

To assess pathological findings and oncological control afforded by radical prostatectomy (RP) in high-risk prostate cancers (PCa) at our institution.     

Oncologic control obtained after radical prostatectomy in men with a pathological Gleason score ≥ 8: A single-center experience

ObjectiveTo assess the oncologic control afforded by radical prostatectomy (RP) in high-risk prostate cancers with a Gleason score ≥ 8.Materials and methodsWe performed a retrospective review of prostate cancer patients who underwent RP between 1995 and 2005 for prostate cancer and who had a pathologic Gleason score ≥ 8. Biochemical recurrence was defined as a single rise in PSA levels over 0.2 ng/ml after surgery.ResultsOverall, 64 patients were included and followed for a median time of 84.3 months. The mean age was 63 ± 5.2 years. The mean preoperative PSA was 11.9 ± 7.3 ng/ml (1.9–31), and 29 patients (46%) had a PSA > 10 ng/ml. The biopsy Gleason score was ≤7 for 49 patients (76.6%). After pathologic analysis, there were 25 (39%) stage pT2, 37 (58%) stage pT3, and 2 (3%) stage pT4 patients. Nine patients had lymph node involvement (14%). The surgical margins were positive in 25 patients (39%). In 51 patients, (80%) the Gleason score was underestimated by biopsies: 40 patients with a definitive score of Gleason 8 had a Gleason score of 6 or 7 on biopsies, while 11 patients with a Gleason score of 9 initially, had a Gleason score of 7 or 8. Twenty-seven patients underwent adjuvant treatment: external radiation therapy (n = 19), HRT (n = 3), or both (n = 5). During follow-up, 41 patients (64%) presented with a biochemical recurrence, and 11 (17%) died. The PSA-free survival rate at five year was 44%.ConclusionRP remains a possible therapeutic option in certain cases of the high-risk cohort of patients with a Gleason score ≥ 8. However, patients should be warned that surgery might only be the first step of a multi-modal treatment approach. The modalities of adjuvant treatments and the right schedule to deliver it following RP still need to be defined.     

Assessing the complications of laparoscopic robot-assisted surgery: the case of radical prostatectomy

Background  

A robot-assisted laparoscopic approach for radical prostatectomy (RALRP) is being adopted increasingly worldwide for the treatment of localized prostate cancer (CaP). Complications assessment is essential to the objective evaluation of any new procedure. This study aimed to assess the perioperative complications encountered during the implementation of a robot-assisted urologic surgery program.     

Characterization of the eg95 gene family in the G6 genotype of Echinococcus granulosus

Cystic echinococcosis in humans and livestock animals is caused by infection with the cestode parasite Echinococcus granulosus. A number of genotypes of the parasite (designated G1-G10) are known to exist, with the genotype cluster G1-G3 and genotype G6 being responsible for the majority of humans infections. A recombinant vaccine has been developed for use in livestock to prevent infection with E. granulosus. The vaccine is based on the antigen EG95 which is expressed in the early larval stage (oncosphere) of the parasite. The EG95 antigen was originally cloned from the G1 genotype of E. granulosus and the protein has been found to be encoded by members of a small family of related genes in this genotype. Reliable information has not been available about the likely efficacy of the EG95 vaccine against genotypes other than G1. In this study, genomic DNA cloning techniques were used to characterize seven eg95-related gene fragments from the G6 genotype of E. granulosus. Three proteins appear to be encoded by these genes. Considerable differences were found between the EG95 related proteins from the G6 genotype compared with the EG95 protein from the G1 genotype. These differences suggest that the EG95-related proteins from the G6 genotype may have different antigenic epitopes compared with the current vaccine antigen. Data presented in this study have implications for future vaccine design and provide the information that would enable a G6 genotype-specific vaccine to be developed against E. granulosus, should this be considered a desirable addition to the available tools for control of cystic echinococcosis transmission.     

Antibody responses and epitope specificities to the Taenia solium cysticercosis vaccines TSOL18 and TSOL45-1A

Taenia solium is a cestode parasite that causes cysticercosis in humans and pigs. This study examined the antibody responses in pigs immunized with the TSOL18 and TSOL45-1A recombinant vaccines against T. solium cysticercosis. Immunization with these proteins induced specific, complement-fixing antibodies against the recombinant antigens that are believed to be associated with vaccine-induced protection against T. solium infection. Sera from immunized pigs were used to define the linear B-cell epitopes of TSOL18 and TSOL45-1A. Prominent reactivity was revealed to one linear epitope on TSOL18 and two linear epitopes on TSOL45-1A. These, and oncosphere antigens from other taeniid cestodes, contain a protein sequence motif suggesting that they may show a tertiary structure similar to the fibronectin type III domain (FnIII). Comparison of the location of linear antigenic epitopes in TSOL18 and TSOL45-1A within the proposed FnIII structure to those within related cestode vaccine antigens reveals conservation in the positioning of the epitopes between oncosphere antigens from different taeniid species.