612 research outputs found
A new animal model of spontaneous autoimmune peripheral polyneuropathy: implications for Guillain-Barré syndrome
BACKGROUND: Spontaneous autoimmune peripheral neuropathy including Guillain-Barré Syndrome (GBS) represents as one of the serious emergencies in neurology. Although pathological changes have been well documented, molecular and cellular mechanisms of GBS are still under-explored, partially due to short of appropriate animal models. The field lacks of spontaneous and translatable models for mechanistic investigations. As GBS is preceded often by viral or bacterial infection, a condition can enhance co-stimulatory activity; we sought to investigate the critical role of T cell co-stimulation in this autoimmune disease. RESULTS: Our previous study reported that transgene-derived constitutive expression of co-stimulator B7.2 on antigen presenting cells of the nervous tissues drove spontaneous neurological disorders. Depletion of CD4(+) T cells in L31 mice accelerated the onset and increased the prevalence of the disease. In the current study, we further demonstrated that L31/CD4(-/-) mice exhibited both motor and sensory deficits, including weakness and paresis of limbs, numbness to mechanical stimuli and hypersensitivity to thermal stimulation. Pathological changes were characterized by massive infiltration of macrophages and CD8(+) T cells, demyelination and axonal damage in peripheral nerves, while changes in spinal cords could be secondary to the PNS damage. In symptomatic L31/CD4(-/-) mice, the disruption of the blood neural barriers was observed mainly in peripheral nerves. Interestingly, the infiltration of immune cells was initiated in pre-symptomatic L31/CD4(-/-) mice, prior to the disease onset, in the DRG and spinal roots where the blood nerve barrier is virtually absent. CONCLUSIONS: L31/CD4(-/-) mice mimic most parts of clinical and pathological signatures of GBS in human; thus providing an unconventional opportunity to experimentally explore the critical events that lead to spontaneous, autoimmune demyelinating disease of the peripheral nervous system
SLS4D: Sparse Latent Space for 4D Novel View Synthesis
Neural radiance field (NeRF) has achieved great success in novel view
synthesis and 3D representation for static scenarios. Existing dynamic NeRFs
usually exploit a locally dense grid to fit the deformation field; however,
they fail to capture the global dynamics and concomitantly yield models of
heavy parameters. We observe that the 4D space is inherently sparse. Firstly,
the deformation field is sparse in spatial but dense in temporal due to the
continuity of of motion. Secondly, the radiance field is only valid on the
surface of the underlying scene, usually occupying a small fraction of the
whole space. We thus propose to represent the 4D scene using a learnable sparse
latent space, a.k.a. SLS4D. Specifically, SLS4D first uses dense learnable time
slot features to depict the temporal space, from which the deformation field is
fitted with linear multi-layer perceptions (MLP) to predict the displacement of
a 3D position at any time. It then learns the spatial features of a 3D position
using another sparse latent space. This is achieved by learning the adaptive
weights of each latent code with the attention mechanism. Extensive experiments
demonstrate the effectiveness of our SLS4D: it achieves the best 4D novel view
synthesis using only about parameters of the most recent work.Comment: 10 pages, 6 figure
ISSR Analysis on Genetic Diversity of Wild \u3ci\u3eAgrostis stolonifera\u3c/i\u3e L. Germplasm Resources
ISSR Analysis on Genetic Diversity of Wild \u3ci\u3eAgrostis stolonifera\u3c/i\u3e L. Germplasm Resources
Prevalence of Clonorchis sinensis infection in dogs and cats in subtropical southern China
<p>Abstract</p> <p>Background</p> <p>Clonorchiasis, caused by <it>Clonorchis sinensis</it>, is one of the major parasitic zoonoses in China, particularly in China's southern Guangdong province where the prevalence of <it>C. sinensis </it>infection in humans is high. However, little is known of the prevalence of <it>C. sinensis </it>infection in its reservoir hosts dogs and cats. Hence, the prevalence of <it>C. sinensis </it>infection in dogs and cats was investigated in Guangdong province, China between October 2006 and March 2008.</p> <p>Results</p> <p>A total of 503 dogs and 194 cats from 13 administrative regions in Guangdong province were examined by post-mortem examination. The worms were examined, counted, and identified to species according to existing keys and descriptions. The average prevalences of <it>C. sinensis </it>infection in dogs and cats were 20.5% and 41.8%, respectively. The infection intensities in dogs were usually light, but in cats the infection intensities were more serious. The prevalences were higher in some of the cities located in the Pearl River Delta region which is the most important endemic area in Guangdong province, but the prevalences were relatively lower in seaside cities.</p> <p>Conclusions</p> <p>The present investigation revealed a high prevalence of <it>C. sinensis </it>infection in its reservoir hosts dogs and cats in China's subtropical Guangdong province, which provides relevant "base-line" data for conducting control strategies and measures against clonorchiasis in this region.</p
A novel prognostic model for predicting the risk of first variceal hemorrhage in patients with HBV-related cirrhosis
BackgroundVariceal hemorrhage (VH) is a life-threatening complication of cirrhosis. An accurate VH risk evaluation is critical to determine appropriate prevention strategies. We aimed to develop an individualized prediction model to predict the risk of first VH in hepatitis B virus (HBV)-related cirrhotic patients.MethodsA nomogram was developed based on a retrospective analysis of 527 consecutive HBV-related cirrhotic patients with gastroesophageal varices (GEVs). The nomogram evaluation was performed using the area under the receiver operating characteristic curve (AUC), concordance index (C-index), calibration plot, and decision curve analysis (DCA). The results were verified using an external cohort (n = 187).ResultsWe developed a nomogram based on clinical and endoscopic features, including the size of varices, red wale marks, ascites, spleen thickness, γ‐glutamyltransferase, and hematocrit. The C-index of the nomogram in the derivation and validation cohort was 0.806 and 0.820, respectively, and the calibration plot fitted well. Compared with those of the North Italian Endoscopic Club (NIEC) and revised NIEC indexes, the AUC (derivation cohort: 0.822 vs. 0.653 vs. 0.713; validation cohort: 0.846 vs. 0.685 vs. 0.747) and DCA curves of this nomogram were better. Further, based on the risk scores, patients were classified into low-, medium-, and high-risk groups, and significant differences were noted in VH incidence among the three risk groups (P <0.001 for each cohort).ConclusionsAn effective individualized nomogram to predict the risk of first VH in HBV-related GEV patients was established, which can assist clinicians in developing more appropriate prevention strategies
Mapping the distribution of Anthrax in Mainland China, 2005-2013
Anthrax in China was characterized by significant seasonality and spatial clustering. The spatial distribution of human anthrax was largely driven by livestock husbandry, human density, land cover, elevation, topsoil features and climate. Enhanced surveillance and intervention for livestock and human anthrax in the high-risk regions, particularly on the Qinghai-Tibetan Plateau, is the key to the prevention of human infections
Tip-enhanced Raman spectroscopy for investigating adsorbed species on a single-crystal surface using electrochemically prepared Au tips
A tip-enhanced Raman instrument was set up based on a homemade optical fiber Raman head, a dispersive spectrograph, and a scanning tunneling microscope (STM) system. Electrochemical preparation of tip-enhanced Raman spectroscopy (TERS) Au tips was refined by using the etching current as ending point control, resulting in a success rate as high as 90%. The high quality Au tips allow the recording of STM images with molecular resolution and TERS spectra of nonresonant surface species on a single-crystal surface. (c) 2007 American Institute of Physics
Mycobacterium vaccae as Adjuvant Therapy to Anti-Tuberculosis Chemotherapy in Never-Treated Tuberculosis Patients: A Meta-Analysis
OBJECTIVE: To evaluate the effectiveness and safety of heat-killed M. vaccae added to chemotherapy of never-treated tuberculosis (TB) patients. METHODS: The databases of Medline, Embase, Biosis, Cochrane Central Register of Controlled Trials, SCI, CBM, VIP and CNKI were searched. Randomized controlled trials (RCT) and Controlled clinical trials (CCT) comparing M. vaccae with or without a placebo-control injection as adjuvant therapy in the chemotherapy of never-treated TB patients were included. Two reviewers independently performed data extraction and quality assessment. Data were analyzed using RevMan 5.0 software by The Cochrane Collaboration. RESULTS: Fifty four studies were included. At the end of the follow-up period, Pooled RR (Risk Ratio) and its 95% CI of sputum smear conversion rate were 1.07 (1.04, 1.10) in TB patients without complications, 1.17 (0.92, 1.49) in TB patients with diabetes mellitus, 1.02 (0.94, 1.10) in TB patients with hepatitis B, and 1.46 (0.21, 10.06) in TB patients with pneumosilicosis. In elderly TB patients the RR was 1.22 (1.13, 1.32). Analysis of each time point during the follow-up period showed that M. vaccae could help to improve the removal of acid-fast bacilli from the sputum, and promote improvement of radiological focal lesions and cavity closure. Compared with the control group, the differences in levels of immunological indicators of Th1 such as IL-2 and TNF-α were not statistical significant (P = 0.65 and 0.31 respectively), and neither was that of IL-6 produced by Th2 (P = 0.52). An effect of M. vaccae of prevention of liver damage was found in TB patients with hepatitis B (RR 0.20 and 95% CI (0.12, 0.33). No systemic adverse events were reported. CONCLUSION: Added to chemotherapy, M. vaccae is helpful in the treatment of never-treated TB patients in terms of improving both sputum conversion and X-ray appearances
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