12 research outputs found

    Identification of Immunogenic Salmonella enterica Serotype Typhi Antigens Expressed in Chronic Biliary Carriers of S. Typhi in Kathmandu, Nepal

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    Background: Salmonella enterica serotype Typhi can colonize and persist in the biliary tract of infected individuals, resulting in a state of asymptomatic chronic carriage. Chronic carriers may act as persistent reservoirs of infection within a community and may introduce infection to susceptible individuals and new communities. Little is known about the interaction between the host and pathogen in the biliary tract of chronic carriers, and there is currently no reliable diagnostic assay to identify asymptomatic S. Typhi carriage. Methodology/Principal Findings To study host-pathogen interactions in the biliary tract during S. Typhi carriage, we applied an immunoscreening technique called in vivo-induced antigen technology (IVIAT), to identify potential biomarkers unique to carriers. IVIAT identifies humorally immunogenic bacterial antigens expressed uniquely in the in vivo environment, and we hypothesized that S. Typhi surviving in the biliary tract of humans may express a distinct antigenic profile. Thirteen S. Typhi antigens that were immunoreactive in carriers, but not in healthy individuals from a typhoid endemic area, were identified. The identified antigens included a number of putative membrane proteins, lipoproteins, and hemolysin-related proteins. YncE (STY1479), an uncharacterized protein with an ATP-binding motif, gave prominent responses in our screen. The response to YncE in patients whose biliary tract contained S. Typhi was compared to responses in patients whose biliary tract did not contain S. Typhi, patients with acute typhoid fever, and healthy controls residing in a typhoid endemic area. Seven of 10 (70%) chronic carriers, 0 of 8 bile culture-negative controls (0%), 0 of 8 healthy Bangladeshis (0%), and 1 of 8 (12.5%) Bangladeshis with acute typhoid fever had detectable anti-YncE IgG in blood. IgA responses were also present. Conclusions/Significance: Further evaluation of YncE and other antigens identified by IVIAT could lead to the development of improved diagnostic assays to identify asymptomatic S. Typhi carriers

    Formal Modelling of Incidents and Accidents as a Means for Enriching Training Material for Satellite Control Operations

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    International audiencePreventing incidents and accidents from recurring is a way of improving safety and reliability of safetycritical systems. When iterations of the development process can be rapid (as for instance for most web applications), the system can be easily modified and redeployed integrating behavioural changes that would prevent the same incident or accident from recurring. When the development process is more resource consuming by, for instance, the addition of certification phases and the need to abide by standards, the design and implementation of barriers (Hollnagel 2004) is considered. Previous research (Basnyat et al. 2007) proposes the specification and integration of barriers to existing systems in order to prevent undesired consequences. Such barriers are designed so that they can be considered as patches over an already existing and deployed system. These two aforementioned approaches are potentially complementary (typically, one would be preferred to the other depending on the severity of the failures or incidents that occurred), putting the system at the centre of the preoccupations of the devel

    Beyond usability for safety critical systems: How to be SURE (safe, usable, reliable, and evolvable)?

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    International audienceWhile a significant effort is currently being undertaken by the CHI community in order to apply and extend current usability evaluation techniques to new kinds of interaction techniques very little has been done to improve the reliability of software offering these kinds of interaction techniques. As these new interaction techniques are currently more and more used in the field of command and control safety critical systems the potential of incident or accidents increases. Similarly, the non reliability of interactive software can jeopardize usability evaluation by showing unexpected or undesired behaviors. Lastly, iterative design processes promote multiple designs through evolvable prototypes in order to accommodate requirements changes and results from usability evaluations thus reducing reliability of the final system by lack of global and structured design. The aim of this SIG is to provide a forum for both researchers and practitioners interested in safety critical interactive systems. Our goal is to define a roadmap of activities to cross fertilize usability, reliability and safety for these kinds of systems to minimize duplicate efforts and reuse knowledge in all the communities involved

    Characterization of anti- Vi immune responses.

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    <p>Anti- Vi antigen IgG (A) and IgA (B) responses were evaluated in <i>S.</i> Typhi carriers (Typhi carrier), <i>S.</i> Paratyphi A carriers (PTA carrier), Nepalese controls undergoing elective cholecystectomy with negative bile cultures (GB control), healthy Bangladeshi controls (HB control), and patients at the day 0–3 acute (Typhi acute) and day 14–28 convalescent phase (Typhi conv) of typhoid fever with confirmed <i>S.</i> Typhi bacteremia.</p

    Characterization of anti- YncE immune responses.

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    <p>Anti-YncE IgG (A) and IgA (B) responses in <i>S.</i> Typhi carriers (Typhi carrier), <i>S.</i> Paratyphi A carriers (PTA carrier), Nepalese controls undergoing elective cholecystectomy with negative bile cultures (GB control), Healthy Bangladeshi controls (HB control), and patients at the day 0–3 acute (Typhi acute) and day 14–28 convalescent phase (Typhi conv) of typhoid fever with confirmed <i>S.</i> Typhi bacteremia.</p

    The impact of surgical delay on resectability of colorectal cancer: An international prospective cohort study

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    AimThe SARS-CoV-2 pandemic has provided a unique opportunity to explore the impact of surgical delays on cancer resectability. This study aimed to compare resectability for colorectal cancer patients undergoing delayed versus non-delayed surgery.MethodsThis was an international prospective cohort study of consecutive colorectal cancer patients with a decision for curative surgery (January-April 2020). Surgical delay was defined as an operation taking place more than 4 weeks after treatment decision, in a patient who did not receive neoadjuvant therapy. A subgroup analysis explored the effects of delay in elective patients only. The impact of longer delays was explored in a sensitivity analysis. The primary outcome was complete resection, defined as curative resection with an R0 margin.ResultsOverall, 5453 patients from 304 hospitals in 47 countries were included, of whom 6.6% (358/5453) did not receive their planned operation. Of the 4304 operated patients without neoadjuvant therapy, 40.5% (1744/4304) were delayed beyond 4 weeks. Delayed patients were more likely to be older, men, more comorbid, have higher body mass index and have rectal cancer and early stage disease. Delayed patients had higher unadjusted rates of complete resection (93.7% vs. 91.9%, P = 0.032) and lower rates of emergency surgery (4.5% vs. 22.5%, P ConclusionOne in 15 colorectal cancer patients did not receive their planned operation during the first wave of COVID-19. Surgical delay did not appear to compromise resectability, raising the hypothesis that any reduction in long-term survival attributable to delays is likely to be due to micro-metastatic disease
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