945 research outputs found
Timing for treatment of HCV recurrence after liver transplantation: the earlier the better.
HCV is the leading cause of death from liver disease and is the most common indication for a liver transplantation. Although HCV is a widespread health problem, disease management is particularly challenging in several key subpopulations, including liver transplant recipients. HCV recurrence after liver transplantation constituted a major challenge for the physicians during the last years. The recommended standard of care before the advent of new regimen was the treatment of confirmed recurrent disease, based either on persistent, unexplained elevated alanine aminotransferase levels or on histologically confirmed fibrosis, once rejection, biliary obstruction, and vascular damage have been ruled out. Moreover, early therapy (including interferon) has been associated with high rates of adverse effects, an increased risk of graft rejection, and higher proportions of patients requiring dose reductions. We are now facing a "new era" of direct antiviral agents that is already changing the approach to HCV burden in the post liver transplantation setting. Available data on treatment of HCV recurrence with the new antiviral drugs showed sustained virological response that ranges between 60 to 100%. In this comment we have focused on both the utility of non invasive test to evaluate the fibrosis progression and on timing of antiviral therapy for HCV recurrence. This article is protected by copyright. All rights reserved
Cancer-Associated Thrombosis in Cirrhotic Patients with Hepatocellular Carcinoma.
It is common knowledge that cancer patients are more prone to develop venous thromboembolic complications (VTE). It is therefore not surprising that patients with hepatocellular carcinoma (HCC) present with a significant risk of VTE, with the portal vein being the most frequent site (PVT). However, patients with HCC are peculiar as both cancer and liver cirrhosis are conditions that can perturb the hemostatic balance towards a prothrombotic state. Because HCC-related hypercoagulability is not clarified at all, the aim of the present review is to summarize the currently available knowledge on epidemiology and pathogenesis of non-malignant thrombotic complications in patients with liver cirrhosis and HCC. They are at increased risk to develop both PVT and non-splanchnic VTE, indicating that both local and systemic factors can foster the development of site-specific thrombosis. Recent studies have suggested multiple and often interrelated mechanisms through which HCC can tip the hemostatic balance of liver cirrhosis towards hypercoagulability. Described mechanisms include increased fibrinogen concentration/polymerization, thrombocytosis, and release of tissue factor-expressing extracellular vesicles. Currently, there are no specific guidelines on the use of thromboprophylaxis in this unique population. There is the urgent need of prospective studies assessing which patients have the highest prothrombotic profile and would therefore benefit from early thromboprophylaxis
Phytoplasma Infection of a Tropical Root Crop Triggers Bottom-Up Cascades by Favoring Generalist Over Specialist Herbivores
Global interest on plant-microbe-insect interactions is rapidly growing, revealing the multiple ways in which microorganisms mediate plant-herbivore interactions. Phytopathogens regularly alter whole repertoires of plant phenotypic traits, and bring about shifts in key chemical or morphological characteristics of plant hosts. Pathogens can also cause cascading effects on higher trophic levels, and eventually shape entire plant-associated arthropod communities. We tested the hypothesis that a Candidatus Phytoplasma causing cassava witches’ broom (CWB) on cassava (Manihot esculenta Grantz) is altering species composition of invasive herbivores and their associated parasitic hymenopterans. We conducted observational studies in cassava fields in eastern Cambodia to assess the effect of CWB infection on abundance of specialist and generalist mealybugs (Homoptera: Pseudococcidae), and associated primary and hyper-parasitoid species. CWB infection positively affects overall mealybug abundance and species richness at a plant- and field-level, and disproportionately favors a generalist mealybug over a specialist feeder. CWB phytoplasma infection led to increased parasitoid richness and diversity, with richness of ‘comparative’ specialist taxa being the most significantly affected. Parasitism rate did not differ among infected and uninfected plants, and mealybug host suppression was not impacted. CWB phytoplasma modifies host plant quality for sap-feeding homopterans, differentially affects success rates of two invasive species, and generates niche opportunities for higher trophic orders. By doing so, a Candidatus phytoplasma affects broader food web structure and functioning, and assumes the role of an ecosystem engineer. Our work unveils key facets of phytoplasma ecology, and sheds light upon complex multi-trophic interactions mediated by an emerging phytopathogen. These findings have further implications for invasion ecology and management
Influence of Air pollution on Central Nervous System –An Overview
Air pollution is a multifaceted environmental toxin capable of assaulting the CNS through diverse pathways. Air pollution is a complex mixture of environmental toxicants that assault the CNS through several cellular and molecular pathways to cause disease. Air pollution effects cross from the periphery to the brain through systemic inflammation, and translocation of nanoparticles to the brain, where both the physical characteristics of the particle itself and the toxic compounds adsorbed on the particle may cause damage. Air pollution has also been associated with diseases of the central nervous system (CNS), including stroke, Alzheimer’s disease, Parkinson’s disease, and neurodevelopmental disorders. Air pollution causes neuroin?ammation, oxidative stress, microglial activation, cerebrovascular dysfunction, and alterations in the blood-brain barrier contribute to CNS pathology. The central nervous system (CNS) is the target organ for the detrimental effects of airborne pollutants. Air pollutants such as gases (e.g., ground-level ozone, carbon monoxide, sulfur oxides, and nitrogen oxides), organic compounds (e.g., polycyclic aromatic hydrocarbons and bacterial endotoxins), and toxic metals (e.g., vanadium, lead, nickel, copper, and manganese) that can be found in outdoor and indoorair affect the CNS. Air pollution is a global problem and has become one of the major issues of public health as well as climate and environmental protection. Heavy traffic causes Air pollution, those effects on CNS damage and that there is a clear link between air pollution and neurological diseases. Understanding of the mediators and mechanisms of CNS injury due to air pollution will help to develop preventive and treatment strategies for the protection of individuals at risk
Drop-out rate from the liver transplant waiting list due to HCC progression in HCV-infected patients treated with direct acting antivirals.
BACKGROUND & AIM: concerns about an increased hepatocellular carcinoma (HCC) recurrence rate following directly acting antiviral (DAA) therapy in cirrhotic patients with a prior complete oncological response have been raised. Data regarding the impact of HCV-treatment with DAAs on waiting list drop-out rates in patients with active HCC and HCV-related cirrhosis awaiting liver transplantation (LT) are lacking.
MATERIALS AND METHODS: HCV-HCC patients listed for LT between January 2015 and May 2016 at Padua Liver Transplant Centre were considered eligible for the study. After enrollment patients were divided into 2 groups, depending on whether they underwent DAAs treatment while awaiting LT or not. For each patient clinical, serological and virological data were collected. HCC characteristics were radiologically evaluated at baseline and during follow-up (FU). For transplanted patients, pathological assessment of the explants was performed and recurrence-rates were calculated.
RESULTS: twenty-three patients treated with DAAs and 23 controls were enrolled. HCC characteristics at time of LT-listing were comparable between the 2 groups. Median FU was 10 and 7 months, respectively, during which 2/23 (8.7%) and 1/23 (4.3%) drop-out events due to HCC-progression were registered (p = 0.9). No significant differences in terms of radiological progression were highlighted (p = 0.16). Nine out of 23 cases (39%) and 14/23 (61%) controls underwent LT, and histopathological analysis showed no differences in terms of median number and total tumor volume of HCC nodules, tumor differentiation or microvascular invasion. During post-LT FU, 1/8 DAAs treated patient (12,5%) and 1/12 control (8,3%) experienced HCC recurrence (p = 0.6).
CONCLUSIONS: Viral eradication does not seem to be associated with an increased risk of drop-out due to neoplastic progression in HCV-HCC patients awaiting LT
Universality of Level Spacing Distributions in Classical Chaos
We suggest that random matrix theory applied to a classical action matrix can
be used in classical physics to distinguish chaotic from non-chaotic behavior.
We consider the 2-D stadium billiard system as well as the 2-D anharmonic and
harmonic oscillator. By unfolding of the spectrum of such matrix we compute the
level spacing distribution, the spectral auto-correlation and spectral
rigidity. We observe Poissonian behavior in the integrable case and Wignerian
behavior in the chaotic case. We present numerical evidence that the action
matrix of the stadium billiard displays GOE behavior and give an explanation
for it. The findings present evidence for universality of level fluctuations -
known from quantum chaos - also to hold in classical physics
Recommended from our members
Mapping individual brains to guide restorative therapy after stroke: rationale and pilot studies.
Some treatments under development to improve motor outcome after stroke require information about organization of individual subject's brain. The current study aimed to characterize normal inter-subject differences in localization of motor functions, and to consider these findings in relation to a potential treatment of motor deficits after stroke. Functional MRI (fMRI) scanning in 14 subjects examined right index finger tapping, shoulder rotation, or facial movement. The largest activation cluster in left sensorimotor cortex was identified for each task, and its center expressed in Talairach stereotaxic coordinates. Across subjects, each task showed considerable variability in activation site coordinates. For example, during finger tapping, the range for center of activation was 7 mm in the x-axis, 19 mm in the y-axis, and 11 mm in the z-axis. The mean value for center of activation was significantly different for all three coordinates for all pairwise task comparisons. However, the distribution of activation site centers for the finger task overlapped with the other two tasks in the x- and y-axes, and with the shoulder task in the z-axis. On average, the center of activation for the three motor tasks were spatially separated and somatotopically distributed. However, across the population, there was considerable overlap in the center of activation site, especially for finger and shoulder movements. Restorative therapies that aim to target specific body segments, such as the hand, in the post-stroke motor system may need to map the individual brain rather than rely on population averages. Initial details are presented of a study using this approach to evaluate such a therapy
Recommended from our members
Use of functional MRI to guide decisions in a clinical stroke trial.
Background and purposeAn investigational trial examined safety and efficacy of targeted subthreshold cortical stimulation in patients with chronic stroke. The anatomical location for the target, hand motor area, varies across subjects, and so was localized with functional MRI (fMRI). This report describes the experience of incorporating standardized fMRI into a multisite stroke trial.MethodsAt 3 enrollment centers, patients moved (0.25 Hz) the affected hand during fMRI. Hand motor function was localized at a fourth center guiding intervention for those randomized to stimulation.ResultsThe fMRI results were available within 24 hours. Across 12 patients, activation site variability was substantial (12, 23, and 11 mm in x, y, and z directions), exceeding stimulating electrode dimensions.ConclusionsUse of fMRI to guide decision-making in a clinical stroke trial is feasible
MobileNetV2-based Transfer Learning Model with Edge Computing for Automatic Fabric Defect Detection
In textile manufacturing, fabric defect detection is an essential quality control step and a challenging task. Earlier, manual efforts were applied to detect defects in fabric production. Human exhaustion, time consumption, and lack of concentration are the main problems in the manual defect detection process. Machine vision systems based on deep learning play a vital role in the Industrial Internet of things (IIoT) and fully automated production processes. Deep learning centered on Convolution Neural Network (CNN) models have been commonly used in fabric defect detection, but most of these models require high computing resources. This work presents a lightweight MobileNetV2-based Transfer Learning model to assist defect detection with low power consumption, low latency, easy upgrade, more efficiency, and an automatic visual inspection system with edge computing. Firstly, different image transformation techniques were performed as data augmentation on four fabric datasets for the model's adaptability in various fabrics. Secondly, fine-tuning hyperparameters of the MobileNetV2 with transfer learning gives a lightweight, adaptable and scalable model that suits the resource-constrained edge device. Finally, deploy the trained model to the NVIDIA Jetson Nano-kit edge device to make its detection faster. We assessed the model based on its accuracy, sensitivity rate, specificity rate, and F1 measure. The numerical simulation reveals that the model accuracy is 96.52%, precision is 96.52%, recall is 96.75%, and F1-Score is 96.52%
Management of infections pre- and post-liver transplantation: Report of an AISF consensus conference
The burden of infectious diseases both before and after liver transplantation is clearly attributable to the dysfunction of defensive mechanisms of the host, both as a result of cirrhosis, as well as the use of immunosuppressive agents. The present document represents the recommendations of an expert panel commended by the Italian Association for the Study of the Liver (AISF), on the prevention and management of infectious complications excluding hepatitis B, D, C, and HIV in the setting of liver transplantation. Due to a decreased response to vaccinations in cirrhosis as well as within the first six months after transplantation, the best timing for immunization is likely before transplant and early in the course of disease. Before transplantation, a vaccination panel including inactivated as well as live attenuated vaccines is recommended, while oral polio vaccine, Calmette-Guerin's bacillus, and Smallpox are contraindicated, whereas after transplantation, live attenuated vaccines are contraindicated. Before transplant, screening protocols should be divided into different levels according to the likelihood of infection, in order to reduce costs for the National Health Service. Recommended preoperative and postoperative prophylaxis varies according to the pathologic agent to which it is directed (bacterial vs. viral vs. fungal). Timing after transplantation greatly determines the most likely agent involved in post-transplant infections, and specific high-risk categories of patients have been identified that warrant closer surveillance. Clearly, specifically targeted treatment protocols are needed upon diagnosis of infections in both the pre- as well as the post-transplant scenarios, not without considering local microbiology and resistance patterns
- …