Exercise-Induced Neuroprotection in SMA Model Mice: A Means for Determining New Therapeutic Strategies

Due to the prevalence of neuromuscular disorders such as amyotrophic lateral sclerosis and spinal muscular atrophy in modern societies, defining new and efficient strategies for the treatment of these two neurodegenerative diseases has become a vital and still unfulfilled urge. Several lines of experimental evidence have emphasized the benefits of regular exercise training in mouse models for these affections in terms of life span increase and improvement of both motor capacities and motoneuron survival. Identifying molecules that could mimic the neuroprotective effects of exercise represents a promising way to find novel therapies. Some of the effects of exercise are caused by the overproduction of circulating neurotrophic factors, such as IGF-I, whereas others may be due to modifications of the intrinsic properties of the motoneurons within the spinal cord. The causal relationship that links these potential effects of exercise training and the improvement of motor capacity and life span expectancy is consequently discussed.     

Mitochondrial Regulation of Neuronal Plasticity

The structure and function of neurons is dynamic during development and in adaptive responses of the adult nervous system to environmental demands. The mechanisms that regulate neuronal plasticity are poorly understood, but are believed to involve neurotransmitter and neurotrophic factor signaling pathways. In the present article, I review emerging evidence that mitochondria play important roles in regulating developmental and adult neuroplasticity. In neurons, mitochondria are located in axons, dendrites, growth cones and pre- and post-synaptic terminals where their movements and functions are regulated by local signals such as neurotrophic factors and calcium influx. Mitochondria play important roles in fundamental developmental processes including the establishment of axonal polarity and the regulation of neurite outgrowth, and are also involved in synaptic plasticity in the mature nervous system. Abnormalities in mitochondria are associated with neurodegenerative and psychiatric disorders, suggesting a therapeutic potential for approaches that target mitochondrial mechanisms. Special issue dedicated to John P. Blass.     

Electromyographic evaluation of masseter and anterior temporalis muscles in rest position of edentulous patients with temporomandibular disorders, before and after using complete dentures with sliding plates

Objectives: This study was performed with the purpose of investigating electromyographic (EMG) activity of the anterior temporalis and masseter muscles in edentulous individuals with temporomandibular disorder (TMD), before and after using sliding plates on complete dentures in the mandibular rest position. Background: Edentulous patients may present TMD, which is characterised by pain in temporomandibular joints, masticatory and neck muscles, uncoordinated and limited mandible movements, joint sounds and an altered occlusal relationship. It is imperative to offer treatment in order to re‐establish stomatognathic system structures before submitting the individual to any definitive restorative treatment. Materials and methods: The patients were edentulous for at least 10 years. EMG recordings were made before the insertion of the dentures (0 months) and also after using the sliding plates at the fourth month, 9th month and 12th month, using computerised electromyography K6‐I/ EMG Light Channel Surface. EMG evaluations of the muscles were performed under the following clinical conditions: rest position with dentures (R1), rest position without dentures (R2), rest position with dentures post‐activity (chewing) (R3), rest position without dentures post‐activity (chewing) (R4). Results: All patients obtained remission of muscular fatigue and reduced pain in stomatognathic system structures. Temporalis muscle showed significant increase in EMG activity compared with initial values (p < 0.01). Masseter muscles showed significantly lower mean values (p < 0.01) compared with initial values. Conclusion: The sliding plates allowed the process of neuromuscular deprogramming, contributing to muscular balance of the masticatory system, and are therefore indicated to be used before the fabrication of definitive complete dentures in patients with TMD.     

Increased risk of COVID‐19 infection and mortality in people with mental disorders: analysis from electronic health records in the United States

Concerns have been expressed that persons with a pre‐existing mental disorder may represent a population at increased risk for COVID‐19 infec­tion and with a higher likelihood of adverse outcomes of the infection, but there is no systematic research evidence in this respect. This study assessed the impact of a recent (within past year) diagnosis of a mental disorder – including attention‐deficit/hyperactivity disorder (ADHD), bipolar disorder, depression and schizophrenia – on the risk for COVID‐19 infection and related mortality and hospitalization rates. We analyzed a nation‐wide database of electronic health records of 61 million adult patients from 360 hospitals and 317,000 providers, across 50 states in the US, up to July 29, 2020. Patients with a recent diagnosis of a mental disorder had a significantly increased risk for COVID‐19 infection, an effect strongest for depression (adjusted odds ratio, AOR=7.64, 95% CI: 7.45‐7.83, p<0.001) and schizophrenia (AOR=7.34, 95% CI: 6.65‐8.10, p<0.001). Among patients with a recent diagnosis of a mental disorder, African Americans had higher odds of COVID‐19 infection than Caucasians, with the strongest ethnic disparity for depression (AOR=3.78, 95% CI: 3.58‐3.98, p<0.001). Women with mental disorders had higher odds of COVID‐19 infection than males, with the strongest gender disparity for ADHD (AOR=2.03, 95% CI: 1.73‐2.39, p<0.001). Patients with both a recent diagnosis of a mental disorder and COVID‐19 infection had a death rate of 8.5% (vs. 4.7% among COVID‐19 patients with no mental disorder, p<0.001) and a hospitalization rate of 27.4% (vs. 18.6% among COVID‐19 patients with no mental disorder, p<0.001). These findings identify individuals with a recent diagnosis of a mental disorder as being at increased risk for COVID‐19 infection, which is further exacerbated among African Americans and women, and as having a higher frequency of some adverse outcomes of the infection. This evidence highlights the need to identify and address modifiable vulnerability factors for COVID‐19 infection and to prevent delays in health care provision in this population.     

微生物-肠-脑轴与神经系统疾病的研究进展

肠道微生物对神经系统疾病 (如帕金森病、抑郁症和阿尔兹海默症等) 的治疗具有辅助治疗的作用。其主要通过神经通路、免疫通路以及微生物代谢物等途径在肠-脑轴的作用下影响大脑功能和宿主行为。因此,文中结合国内外的研究进展,就微生物-肠-脑轴在神经系统疾病中的主要作用进行探讨,以期为神经退行性疾病的治疗提供新思路。     

Microbial community in human gut: a therapeutic prospect and implication in health and diseases

The interest in the working and functionality of the human gut microbiome has increased drastically over the years. Though the existence of gut microbes has long been speculated for long over the last few decades, a lot of research has sprung up in studying and understanding the role of gut microbes in the human digestive tract. The microbes present in the gut are highly instrumental in maintaining the metabolism in the body. Further research is going on in this field to understand how gut microbes can be employed as potential sources of novel therapeutics; moreover, probiotics have also elucidated their significant place in this direction. As regards the clinical perspective, microbes can be engineered to afford defence mechanisms while interacting with foreign pathogenic bodies. More investigations in this field may assist us to evaluate and understand how these cells communicate with human cells and promote immune interactions. Here we elaborate on the possible implication of human gut microbiota into the immune system as well as explore the probiotics in the various human ailments. Comprehensive information on the human gut microbiome at the same platform may contribute effectively to our understanding of the human microbiome and possible mechanisms of associated human diseases.