炎症性肠病与营养支持治疗

营养不良在炎症性肠病尤其是克罗恩病患者中相当普遍,每位患者均应做好营养风险筛查,对有营养风险的患者做进一步的营养评估,以鉴别出需要营养支持治疗的患者。营养支持治疗包括肠内营养及肠外营养两种,肠道有一定功能且能耐受者首选肠内营养。肠内营养治疗不仅可以改善患者营养状态,对部分克罗恩病也有诱导缓解及维持缓解的作用。肠内营养作为诱导与维持儿童克罗恩病的一线治疗已成共识,针对成人克罗恩病患者,尤其是并发肠梗阻、肠瘘及围手术期患者,肠内营养也具有重要的辅助治疗作用。在无法实施肠内营养治疗的情况下,或营养需求较高或期望短期内改善营养状况时才考虑肠外营养治疗。本文通过复习文献阐述营养支持治疗在炎症性肠病中的机制及具体实施方法,对肠内营养和肠外营养的适应证、禁忌证、具体方案和并发症进行了总结,为规范制定炎症性肠病患者个体化营养计划与方案,促进患者病情改善提供参考。

Idiopathic ventricular fibrillation with fragmented QRS complex and J wave in resting electrocardiogram

Objective To describe the clinical characteristics of idiopathic ventricular fibrillation （IVF） with fragmented QRS complex （f-QRS） and J wave in resting electrocardiogram. Methods We reviewed data from 21 case subjects in our hospital who were resuscitated after cardiac arrest due to IVF and assessed the prevalence of f-QRS and J wave in resting electrocardiogram （ECG）. All the case subjects were classified among three groups based on the electrocardiographic morphology： group I, both f-QRS and J wave were observed （n = 6）, group II, only J wave was observed （n = 9）, group III, neither f-QRS nor J wave was observed （n = 6）. Population characteristics, history of syncope or sudden cardiac arrest, incidence of ventricular fibrillation （VF）, and circumstance of VF were evaluated among the three groups. Results The incidence of index events （syncope, survived cardiac arrest and VF episodes recorded in implantable cardioverter defibrillator （ICD） or pacemakers） was 13.4 ~ 5.6 per-year in group I, 10.8 ~ 3.9 per-year in group II, and 9.8 -4- 4.2 per-year in group HI. There were significant differences in incidences among the three groups, the most frequent index events were observed in group I. The hazard ratio for incidence was 3.2 （95%CI, 1.1-7.9; P = 0.01）. The history and circumstance of the index events were different among the groups. In group I, all the index events occurred during sleep in early morning. In group II, four subjects suffered VF during strenuous physical activities or agitation state, two during sleep in early morning, three in usual activity. In group III, one subject suffered VF during sleep in early morning, one in agitation state, four in usual activity. Conclusions This study suggests that the IVF patients with the combined appearance of f-QRS and J wave in the resting ECG suffer an increased risk of VF, this subgroup of IVF patients has a unique clinical feature.

Lithium promotes recovery after spinal cord injury

Lithium is associated with oxidative stress and apoptosis,but the mechanism by which lithium protects against spinal cord injury remains poorly understood.In this study,we found that intraperitoneal administration of lithium chloride(LiCl)in a rat model of spinal cord injury alleviated pathological spinal cord injury and inhibited expression of tumor necrosis factorα,interleukin-6,and interleukin 1β.Lithium inhibited pyroptosis and reduced inflammation by inhibiting Caspase-1 expression,reducing the oxidative stress response,and inhibiting activation of the Nod-like receptor protein 3 inflammasome.We also investigated the neuroprotective effects of lithium intervention on oxygen/glucose-deprived PC12 cells.We found that lithium reduced inflammation,oxidative damage,apoptosis,and necrosis and up-regulated nuclear factor E2-related factor 2(Nrf2)and heme oxygenase-1 in PC12 cells.All-trans retinoic acid,an Nrf2 inhibitor,reversed the effects of lithium.These results suggest that lithium exerts anti-inflammatory,anti-oxidant,and anti-pyroptotic effects through the Nrf2/heme oxygenase-1 pathway to promote recovery after spinal cord injury.This study was approved by the Animal Ethics Committee of Xi’an Jiaotong University(approval No.2018-2053)on October 23,2018.

Cell-based therapy for management of osteoarthritis

Osteoarthritis(OA)is a most common form of degenerative joint disease,primarily characterized by the degradation of articular cartilage,subchondral sclerosis and inflammation of the synovial membrane.Mesenchymal stem cells(MSCs),a multipotent adult stem cell population,can be isolated from many connective tissue lineages,including those of the diarthrodial joint.Joint-resident MSCs or MSC-like progenitor cells contribute to the maintenance of healthy microenvironment or to the response to trauma.The onset of degenerative changes in the joint related to abnormal condition or depletion of these endogenous MSCs and native host hyaline cartilage cells,leading to limited selfrepair potential of the joint and advance of the degradation.To date,no acknowledged medical treatment strategies,including non-operative and classical surgical techniques,are efficient in restoring normal anatomy and function of hyaline cartilage in OA.This highlights an urgent need for better celled-based therapeutic strategies that supplement these functional cel s exogenously to recover the tissue homeostasis and repair in joint cavity via chondrogenic and anti-in fl ammatory functions.In this review we focus on the role of native MSCs in healthy or OA joint and recent progress in cel-based researches utilizing culture-expanded chondrocytes,pluripotent stem cel s,or MSCs from different sources for treating OA.

Identification of microRNA precursors with new sequence-structure features

MicroRNAs are an important subclass of non-coding RNAs (ncRNA), and serve as main players into RNA interference (RNAi). Mature microRNA derived from stem-loop structure called precursor. Identification of precursor microRNA (pre-miRNA) is essential step to target microRNA in whole genome. The present work proposed 25 novel local features for identifying stem- loop structure of pre-miRNAs, which captures characteristics on both the sequence and structure. Firstly, we pulled the stem of hairpins and aligned the bases in bulges and internal loops used ‘―’, and then counted 24 base-pairs (‘AA’, ‘AU’, …, ‘―G’, except ‘――’) in pulled stem (formalized by length of pulled stem) as features vector of Support Vector Machine (SVM). Performances of three classifiers with our features and different kernels trained on human data were all superior to Triplet-SVM-classifier’s in po- sitive and negative testing data sets. Moreover, we achieved higher prediction accuracy through combining 7 global sequence-structure. The result indicates validity of novel local features.

Synthetic Two-dimensional Organic Structures

Synthetic two-dimensional（2 D） polymers have totally different topology structures compared with traditional linear or branched polymers. The peculiar 2 D structures bring superior properties. Although, from linear to 2 D polymers, the study of these new materials is still in its infancy, they already show potential applications especially in optoelectronics, membranes, energy storage and catalysis, etc. In this review, we summarize the recent progress of the 2 D materials from three respects：（1） Chemistry—different types of polymerization reactions or supramolecular assembly to construct the 2 D networks were described;（2） Preparation methods—surface science, crystal engineering approaches and solution synthesis were introduced;（3） Functionalization and some early applications.