In vitro myogenesis induced by human recombinant elastin-like proteins

Mammalian adult skeletal muscle has a limited ability to regenerate after injury, usage or trauma. A promising strategy for successful regenerative technology is the engineering of bio interfaces that mimic the characteristics of the extracellular matrix. Human elastin-like polypeptides (HELPs) have been synthesized as biomimetic materials that maintain some peculiar properties of the native protein. We developed a novel Human Elastin Like Polypeptide obtained by fusing the elastin-like backbone to a domain present in the α2 chain of type IV collagen, containing two RGD motives. We employed this peptide as adhesion substrate for C2C12 myoblasts and compared its effects to those induced by two other polypeptides of the HELP series. Myoblast adhered to all HELPs coatings, where they assumed morphology and cytoarchitecture that depended on the polypeptide structure. Adhesion to HELPs stimulated at a different extent cell proliferation and differentiation, the expression of Myosin Heavy Chain and the fusion of aligned fibers into multinucleated myotubes. Adhesion substrates significantly altered myotubes stiffness, measured by Atomic Force Microscopy, and differently affected the cells Ca²⁺ handling capacity and the maturation of excitation-contraction coupling machinery, evaluated by Ca²⁺ imaging. Overall, our findings indicate that the properties of HELP biopolymers can be exploited for dissecting the molecular connections underlying myogenic differentiation and for designing novel substrates for skeletal muscle regeneration.     

八髎穴治疗出口梗阻型便秘的机制探讨

出口梗阻型便秘(outlet obstruction constipation,OOC)已经成为影响现代人生活质量的重要疾病之一。本文就近年来国内外有关OOC的发病机制及针刺八髎穴治疗OOC的研究进行了回顾,发现针刺八髎穴可能通过提高神经节内板状末梢改善机械扩张的敏感性,升高血清胆囊收缩素水平,抑制脊髓前角的γ-运动神经元、脊髓内侧角的交感中枢的兴奋性及减少5-羟色胺、组织胺的释放等多途径达到治疗OOC的作用。深入探讨八髎穴治疗OOC的作用机制,可为寻找更为特异和有效的治疗靶点提供实验依据和理论基础。     

Postural instability in Charcot-Marie-Tooth 1A disease

The aim of this study was to evaluate the influence of somatosensory impairment, distal muscle weakness and foot deformities on the balance in 21 CMT1A patients using a baropodometric platform.Stabilometric analysis by measuring sway area and velocity of a centre of pressure (CoP) both at open and closed eyes were used to assess postural imbalance. Static analysis, by measuring the load and the plantar surface of forefoot, midfoot and hindfoot was used to define the footprint shape and to assess as a whole foot deformities. Stabilometric and static results were compared with those of a control group. In CMT1A patients, stabilometric findings were correlated with static parameters, Achilles’ tendon retraction, distal muscle strength and CMT examination score (CMTES). CMT1A patients compared to controls had lower plantar surface and load on midfoot, and higher load on a forefoot. CMT1A patients had a greater postural instability, since they had a higher CoP velocity, both at open and closed eyes. Moreover, the CoP velocity correlated inversely with the strength of ankle dorsi-flexion muscles and directly with CMTES as whole and with the item “motor symptoms legs”. Postural imbalance was not correlated with sensory impairment and foot deformities as expressed by static analysis and Achilles’ tendon retraction.In this study we demonstrated an altered balance in CMT1A patients during upright standing. The imbalance in our CMT patients seems to be related to the weakness of ankle dorsi-flexor muscles rather than sensory impairment or foot deformities. These results could be due to a mildly affected CMT1A population, evaluated in an early stage of the disease.     

Orthogonally oriented scaffolds with aligned fibers for engineering intestinal smooth muscle

Controlling cellular alignment is critical in engineering intestines with desired structure and function. Although previous studies have examined the directional alignment of cells on the surface (x–y plane) of parallel fibers, quantitative analysis of the cellular alignment inside implanted scaffolds with oriented fibers has not been reported. This study examined the cellular alignment in the x–z and y–z planes of scaffolds made with two layers of orthogonally oriented fibers. The cellular orientation inside implanted scaffolds was evaluated with immunofluorescence. Quantitative analysis of coherency between cell orientation and fiber direction confirmed that cells aligned along the fibers not only on the surface (x–y plane) but also inside the scaffolds (x–z & y–z planes). Our study demonstrated that two layers of orthogonally aligned scaffolds can generate the histological organization of cells similar to that of intestinal circular and longitudinal smooth muscle.     

竖脊肌平面阻滞超前镇痛对老年胸腔镜肺癌根治术患者心肌的保护作用

目的探讨竖脊肌平面阻滞（ESPB）超前镇痛对老年胸腔镜肺癌根治术患者心肌的保护作用。 方法选择在惠州市中心人民医院择期行胸腔镜肺癌根治术的老年患者40例，按照患者意愿分组，其中19例采用ESPB联合全身麻醉（观察组），21例采用单纯全身麻醉（对照组）。在两组诱导前（T0）、手术开始1 h（T1）、手术结束时（T2）及术后4 h（T3）检测患者的肌钙蛋白Ⅰ（cTnⅠ）、心型脂肪酸结合蛋白（H-FABP）、肌酸激酶同工酶（CK-MB），并记录各时间点的平均动脉压（MAP）和心率。计量资料的组间比较采用t检验，重复测量资料采用重复测量方差分析。 结果两组患者MAP、心率、cTnⅠ、H-FABP、CK-MB的差异均呈现组间效应、时间效应和交互效应（MAP：F=24.021、33.512、9.184，心率：F=10.340、46.992、3.494，cTnⅠ：F=5.354、691.994、64.177，H-FABP：F=7.906、14.067、11.560，CK-MB：F=15.926、84.106、4.116，P<0.05或0.01）。与T0时间点比较，两组患者T1、T2、T3时间点MAP、心率、H-FABP、CK-MB均出现明显变化（P<0.05），T2、T3时间点cTnⅠ出现明显变化（P<0.05）。 结论老年胸腔镜肺癌根治术中应用ESPB超前镇痛，可明显降低心肌损伤相关因子水平，起到心肌保护作用。     

Relationship between EMG-detected and ultrasound-detected fasciculations in amyotrophic lateral sclerosis: A prospective cohort study

ObjectivesFasciculation potentials (FP) are an important consideration in the electrophysiological diagnosis of ALS. Muscle ultrasonography (MUS) has a higher sensitivity in detecting fasciculations than electromyography (EMG), while in some cases, it is unable to detect EMG-detected fasciculations. We aimed to investigate the differences of FP between the muscles with and without MUS-detected fasciculations (MUS-fas).MethodsThirty-one consecutive patients with sporadic ALS were prospectively recruited and in those, both needle EMG and MUS were performed. Analyses of the amplitude, duration, and number of phases of EMG-detected FPs were performed for seven muscles per patient, and results were compared between the muscles with and without MUS-fas in the total cohort.ResultsThe mean amplitude and phase number of FP were significantly lower in patients with EMG-detected FP alone (0.39 ± 0.25 mV and 3.21 ± 0.88, respectively) than in those with both FP and MUS-fas (1.22 ± 0.92 mV and 3.74 ± 1.39, respectively; p < 0.0001 and p = 0.017, Welch’s t-test).ConclusionSmall FP may be undetectable with MUS. MUS cannot replace EMG in the diagnostic approach for ALS.SignificanceClinicians should use a combination of EMG and MUS for the detection and quantitative analysis of fasciculation in ALS.