Spatio-temporal expression of a novel neuron-derived neurotrophic factor (NDNF) in mouse brains during development

<p>Abstract</p> <p>Background</p> <p>Neuron-derived neurotrophic factor (NDNF) is evolutionarily well conserved, being present in invertebrate animals such as the nematode, <it>Caenorhabditis elegans</it>, as well as in the fruit fly, <it>Drosophila melanogaster</it>. Multiple cysteines are conserved between species and secondary structure prediction shows that NDNF is mainly composed of beta-strands. In this study, we aimed to investigate the function of NDNF.</p> <p>Results</p> <p>NDNF is a glycosylated, disulfide-bonded secretory protein that contains a fibronectin type III domain. NDNF promoted migration and growth and elicited neurite outgrowth of mouse hippocampal neurons in culture. NDNF also protected cultured hippocamal neurons against excitotoxicity and amyloid beta-peptide toxicity. Western blotting showed that NDNF was exclusively expressed in the brain and spinal cord. Immunostaining indicated that NDNF was expressed by neurons and not by astrocytes. Cajal-Retzius cells, cortex neurons, hippocampus neurons, olfactory mitral cells, cerebellar purkinje cells, cerebellar granular cells and spinal neurons were found to be NDNF-positive. NDNF expression was observed in the neurons during development.</p> <p>Conclusions</p> <p>The results of this study indicated that NDNF is a novel neurotrophic factor derived from neurons that may be useful in the treatment of neuronal degeneration diseases and nerve injuries.</p

Ada-DQA: Adaptive Diverse Quality-aware Feature Acquisition for Video Quality Assessment

Video quality assessment (VQA) has attracted growing attention in recent years. While the great expense of annotating large-scale VQA datasets has become the main obstacle for current deep-learning methods. To surmount the constraint of insufficient training data, in this paper, we first consider the complete range of video distribution diversity (\ie content, distortion, motion) and employ diverse pretrained models (\eg architecture, pretext task, pre-training dataset) to benefit quality representation. An Adaptive Diverse Quality-aware feature Acquisition (Ada-DQA) framework is proposed to capture desired quality-related features generated by these frozen pretrained models. By leveraging the Quality-aware Acquisition Module (QAM), the framework is able to extract more essential and relevant features to represent quality. Finally, the learned quality representation is utilized as supplementary supervisory information, along with the supervision of the labeled quality score, to guide the training of a relatively lightweight VQA model in a knowledge distillation manner, which largely reduces the computational cost during inference. Experimental results on three mainstream no-reference VQA benchmarks clearly show the superior performance of Ada-DQA in comparison with current state-of-the-art approaches without using extra training data of VQA.Comment: 10 pages, 5 figures, to appear in ACM MM 202

3-(2-Bromo­phen­yl)thia­zolo[3,2-a]benzimidazole

The title compound, C15H9BrN2S, was prepared by the reaction of 1-bromo-2-(2,2-dibromo­vin­yl)benzene with 1H-benzo[d]imidazole-2(3H)-thione. The thia­zolo[3,2-a]benz­imidazole fused-ring system is nearly planar, the maximum atomic deviation being 0.049 (4) Å. This mean plane is oriented at a dihedral angle of 71.55 (17)° with respect ot the bromo­phenyl ring. π–π stacking is observed in the crystal structure, the centroid–centroid distance between the thia­zole and imidazole rings of adjacent mol­ecules being 3.582 (2) Å

The Expression of Netrin-1 in the Thymus and Its Effects on Thymocyte Adhesion and Migration

Netrin-1, a known axon guidance molecule, being a secreted laminin-related molecule, has been suggested to be involved in multiple physiological and pathological conditions, such as organogenesis, angiogenesis, tumorigenesis, and inflammation-mediated tissue injury. However, its function in thymocyte development is still unknown. Here, we demonstrate that Netrin-1 is expressed in mouse thymus tissue and is primarily expressed in thymic stromal cells, and the expression of Netrin-1 in thymocytes can be induced by anti-CD3 antibody or IL-7 treatment. Importantly, Netrin-1 mediates the adhesion of thymocytes, and this effect is comparable to or greater than that of fibronectin. Furthermore, Netrin-1 specifically promotes the chemotaxis of CXCL12. These suggest that Netrin-1 may play an important role in thymocyte development

Size-dependent in vivo toxicity of PEG-coated gold nanoparticles

Xiao-Dong Zhang, Di Wu, Xiu Shen, Pei-Xun Liu, Na Yang, Bin Zhao, Hao Zhang, Yuan-Ming Sun, Liang-An Zhang, Fei-Yue FanInstitute of Radiation Medicine, Chinese Academy of Medical Sciences and Peking Union Medical College, Tianjin Key Laboratory of Molecular Nuclear Medicine, Tianjin, People&amp;rsquo;s Republic of ChinaBackground: Gold nanoparticle toxicity research is currently leading towards the in vivo experiment. Most toxicology data show that the surface chemistry and physical dimensions of gold nanoparticles play an important role in toxicity. Here, we present the in vivo toxicity of 5, 10, 30, and 60 nm PEG-coated gold nanoparticles in mice.Methods: Animal survival, weight, hematology, morphology, organ index, and biochemistry were characterized at a concentration of 4000 &amp;micro;g/kg over 28 days.Results: The PEG-coated gold particles did not cause an obvious decrease in body weight or appreciable toxicity even after their breakdown in vivo. Biodistribution results show that 5 nm and 10 nm particles accumulated in the liver and that 30 nm particles accumulated in the spleen, while the 60 nm particles did not accumulate to an appreciable extent in either organ. Transmission electron microscopic observations showed that the 5, 10, 30, and 60 nm particles located in the blood and bone marrow cells, and that the 5 and 60 nm particles aggregated preferentially in the blood cells. The increase in spleen index and thymus index shows that the immune system can be affected by these small nanoparticles. The 10 nm gold particles induced an increase in white blood cells, while the 5 nm and 30 nm particles induced a decrease in white blood cells and red blood cells. The biochemistry results show that the 10 nm and 60 nm PEG-coated gold nanoparticles caused a significant increase in alanine transaminase and aspartate transaminase levels, indicating slight damage to the liver.Conclusion: The toxicity of PEG-coated gold particles is complex, and it cannot be concluded that the smaller particles have greater toxicity. The toxicity of the 10 nm and 60 nm particles was obviously higher than that of the 5 nm and 30 nm particles. The metabolism of these particles and protection of the liver will be more important issues for medical applications of gold-based nanomaterials in future.Keywords: gold nanoparticles, in vivo, toxicity, siz