Brain-derived neurotropic factor and GABAergic transmission in neurodegeneration and neuroregeneration

Neurotoxicity induced by stress,radiation,chemicals,or metabolic diseases,is commonly associated with excitotoxicity,oxidative stress,and neuroinflammation.The pathological process of neurotoxicity induces neuronal death,interrupts synaptic plasticity in the brain,and is similar to that of diverse neurodegenerative diseases.Animal models of neurotoxicity have revealed that clinical symptoms and brain lesions can recover over time via neuroregenerative processes.Specifically,brain-derived neurotropic factor（BDNF） and gamma-aminobutyric acid（GABA）-ergic transmission are related to both neurodegeneration and neuroregeneration.This review summarizes the accumulating evidences that suggest a pathogenic role of BDNF and GABAergic transmission,their underlying mechanisms,and the relationship between BDNF and GABA in neurodegeneration and neuroregeneration.This review will provide a comprehensive overview of the underlying mechanisms of neuroregeneration that may help in developing potential strategies for pharmacotherapeutic approaches to treat neurotoxicity and neurodegenerative disease.

Excitation Prediction by Dynamic Transmission Error under Sliding Friction in Helical Gear System

Monte Carlo method was adopted to calculate the meshing error considering the manufacture error and assembly error of the meshing point along the time-varying contact line for helical gear pair. The flexural-torsion-axis dynamic model coupled was established under the tooth friction force and solved by the perturbation method to compute real dynamic tooth load. The change laws of the friction force and friction torque were obtained in a meshing period. The transmission error formulation was analyzed to introduce meshing excitations. The maximum dynamic transmission error, the maximum meshing force and the maximum dynamic factor were calculated under different speeds, external loads and damping factors. The conclusions can provide theoretical basis for the gear design especially in tooth profile correction.

Knowledge, attitudes and practices with regard to the presence, transmission, impact, and control of cystic echinococcosis in Sidi Kacem Province, Morocco

Background:This study is a component of a large research project on five major neglected zoonotic diseases(NZDs)including cystic echinococcosis and was undertaken in the Province of Sidi Kacem over a period of four years(April 2009-March 2013).Methods:Questionnaires were administered at community level in a total of 27 communes and visits were made to all of the 10 abattoirs situated in the Province,to collect qualitative data on determinants of transmission for disease in humans and animals.More specifically,community knowledge,attitudes and practices related to cystic echinococcosis were assessed,as well as the extent to which local customs and behaviours may promote transmission.Abattoir infrastructure and practices,and their role in perpetuating disease transmission were also critically evaluated.Results:The results show that only 50%of people have heard of the disease,and of those,only 21%are aware of the dog’s role in disease transmission.Sixty-seven per cent of respondents stated that dogs are fed ruminant organs deemed unfit for human consumption.Owned dogs have access to the family home,including the kitchen,in 39%of households.The extent of this close proximity between humans and animals is even more pertinent when one considers that dogs are omnipresent in the community,with an average of 1.8 dogs owned per household.The unrestricted access of dogs to abattoirs is a huge issue,which further promotes disease transmission.Conclusion:This study would suggest that the high prevalence of cystic echinococcosis in humans and animals in Morocco is largely due to three factors:1)abundance of dogs 2)engagement in risky behaviour of the local population and 3)poor abattoir infrastructure and practices.This has serious implications in terms of the socio-economic impact of the disease,especially for rural poor communities.

Heijiangdan Ointment(黑绛丹膏)Relieves Oxidative Stress from Radiation Dermatitis Induced by ^(60)Co γ-Ray in Mice

Objective：To investigate the effects of Heijiangdan Ointment（黑绛丹膏,HJD） on oxidative stress in （60）Co γ-ray radiation-induced dermatitis in mice.Methods：Female Wistar mice with grade 4 radiation dermatitis induced by ^（60）Co γ-rays were randomly divided into four groups（n=12 per group）;the HJD-treated,recombinant human epidermal growth factor（rhEGF）-treated,Trolox-treated,and untreated groups,along with a negative control group.On the 11 th and 21 st days after treatment,6 mice in each group were chosen for evaluation.The levels of superoxide dismutase（SOD）,malondialdehyde（MDA）,and lactate dehydrogenase（LDH） were detected using spectrophotometric methods.The fibroblast mitochondria were observed by transmission electron microscopy（TEM）.The expressions of fibroblast growth factor 2（FGF-2） and transforming growth factor β1（TGF-β1） were analyzed by western blot.Results：Compared with the untreated group,the levels of SOD,MDA and LDH,on the 11 th and 21 st days after treatment showed significant difference（P〈0.05）.TEM analysis indicated that fibroblast mitochondria in the untreated group exhibited swelling and the cristae appeared fractured,while in the HJD group,the swelling of mitochondria was limited and the rough endoplasmic reticulum appeared more relaxed.The expressions of FGF-2 and TGF-β1 increased in the untreated group compared with the negative control group（P〈0.05）.After treatment,the expression of FGF-2,rhEGF and Trolox in the HJD group were significantly increased compared with the untreated group（P〈0.05）,or compared with the negative control group（P〈0.05）.The expression of TGF-β1 showed significant difference between untreated and negative control groups（P〈0.05）.HJD and Trolox increased the level of TGF-β1 and the difference was marked as compared with the untreated and negative control groups（P〈0.05）.Conclusion：HJD relieves oxidative stress-induced injury,increases the antioxidant activity,mitigates the fibroblast mitochondrial damage,up-regulates the expression of growth factor,and promotes mitochondrial repair in mice.