Assessment of malnutrition risk in post-stroke patients: a systematic literature review

Stroke is one of the main causes of death, especially when associated with malnutrition. Assessment of nutritional status in all stages of the disease is therefore mandatory to improve clinical outcome

Monocytes Contribute to Differential Immune Pressure on R5 versus X4 HIV through the Adipocytokine Visfatin/NAMPT

Background: The immune system exerts a diversifying selection pressure on HIV through cellular, humoral and innate mechanisms. This pressure drives viral evolution throughout infection. A better understanding of the natural immune pressure on the virus during infection is warranted, given the clinical interest in eliciting and sustaining an immune response to HIV which can help to control the infection. We undertook to evaluate the potential of the novel HIV-induced, monocyte-derived factor visfatin to modulate viral infection, as part of the innate immune pressure on viral populations. Results: We show that visfatin is capable of selectively inhibiting infection by R5 HIV strains in macrophages and resting PBMC in vitro, while at the same time remaining indifferent to or even favouring infection by X4 strains. Furthermore, visfatin exerts a direct effect on the relative fitness of R5 versus X4 infections in a viral competition setup. Direct interaction of visfatin with the CCR5 receptor is proposed as a putative mechanism for this differential effect. Possible in vivo relevance of visfatin induction is illustrated by its association with the dominance of CXCR4-using HIV in the plasma. Conclusions: As an innate factor produced by monocytes, visfatin is capable of inhibiting infections by R5 but not X4 strains, reflecting a potential selective pressure against R5 viruses. © 2012 Van den Bergh et al.SCOPUS: ar.jinfo:eu-repo/semantics/publishe

An integrated modelling approach for R5-X4 mutation and HAART therapy assessment

We have modelled the within-patient evolutionary process during HIV infection using different methodologies. New viral strains arise during the course of HIV infection. These multiple strains of the virus are able to use different coreceptors, in particular the CCR5 and the CXCR4 (R5 and X4 phenotypes, respectively)influence the progression of the disease to the AIDS phase. We present a model of HIV early infection and CTLs response which describes the dynamics of R5 quasispecies, specifying the R5 to X4 switch and effects of immune response. We illustrate dynamics of HIV multiple strains in the presence of multidrug HAART therapy. The HAART combined with X4 strain blocker drugs might help to reduce infectivity and lead to slower progression of disease. On the methodology side, our model represents a paradigm of integrating formal methods and mathematical models as a general framework to study HIV multiple strains during disease progression, and will inch towards providing help in selecting among vaccines and drug therapies. The results presented here are one of the rare cases of methodological cross comparison (stochastic and deterministic) and a novel implementation of model checking in therapy validation

Apparent fractal dimensions in the HMF model

We show that recent observations of fractal dimensions in the space of N body Hamiltonian systems with long range interactions are due to finite N and finite resolution effects. We provide strong numerical evidence that, in the continuum Vlasov limit, a set which initially is not a fractal e.g. a line in 2D remains such for all finite times. We perform this analysis for the Hamiltonian Mean Field HMF model, which describes the motion of a system of N fully coupled rotors. The analysis can be indirectly confirmed by studying the evolution of a large set of initial points for the Chirikov standard ma

Low cost laparoscopic training platform: Primary validation process

The use of simulation in laparoscopic surgery training appears to be qualitatively effective if supported by a suitable evaluation system. The increasing demand of more complex laparoscopic simulators has inspired the creation of a 4d simulator which is a physical low-cost laparoscopic training platform that reproduces the tactile feedback (eLaparo4d) integrated with a software for virtual anatomical realistic scenarios (Unity3D V 4.1). The aim of the present project is to show the validation process results of this system using two instruments: the face validity and the construct validity. The face validity was used for an ergonomic analysis of the simulator, the construct to test the system's ability to differentiate expert users (experienced surgeons in laparoscopy) from non-experts (student without experience in laparoscopic surgery). A sample of 20 students was selected, divided into 2 homogeneous groups with respect to the level of confidence with the use of video games, consolles, smartphones (this has been possible thanks to the use of a questionnaire, administered before the practical phase of training). The groups participated in a training program based on 5 basic laparoscopic skills (laparoscopic focusing and navigation, hand - eye - coordination and grasp coordination). So, a second and third study sample was chosen, consisting of 20 post graduate students (intermediate group) and 20 experienced surgeons in laparoscopy; for theese groups was provided a training program identical to the previous group as well as their subdivision into 2 group. We analyzed the results of the three samples obtained by comparing variables such as: score % of fullfillment panality time At the same time, the students improvements has been monitorized, developing a customized learning curve for each user. To evaluate the structural characteristics of the simulator a specific questionnaire has been used. The results encouraged us. The simulator is ergonomically satisfactory and its structural features are adapted to the training. The system was able to differentiate the level of experience and also has therefore met the requirements of "construct validity"