Bi-layer collagen/microporous electrospun nanofiber scaffold improves the osteochondral regeneration

An optimal scaffold is crucial for osteochondral regeneration. Collagen and electrospun nanofibers have been demonstrated to facilitate cartilage and bone regeneration, respectively. However, the effect of combining collagen and electrospun nanofibers on osteochondral regeneration has yet to be evaluated. Here, we report that the combination of collagen and electrospun poly-l-lactic acid nanofibers synergistically promotes osteochondral regeneration. We first fabricated bi-layer microporous scaffold with collagen and electrospun poly-l-lactic acid nanofibers (COL-nanofiber). Mesenchymal stem cells were cultured on the bi-layer scaffold and their adhesion, proliferation and differentiation were examined. Moreover, osteochondral defects were created in rabbits and implanted with COL-nanofiber scaffold. Cartilage and subchondral bone regeneration were evaluated at 6 and 12 weeks after surgery. Compared with COL scaffold, cells on COL-nanofiber scaffold exhibited more robust osteogenic differentiation, indicated by higher expression levels of OCN and runx2 genes as well as the accumulation of calcium nodules. Furthermore, implantation of COL-nanofiber scaffold seeded with cells induced more rapid subchondral bone emergence, and better cartilage formation, which led to better functional repair of osteochondral defects as manifested by histological staining, biomechanical test and micro-computed tomography data. Our study underscores the potential of using the bi-layer microporous COL-nanofiber scaffold for the treatment of deep osteochondral defects.     

Lipid droplets may lay a spacial foundation for vasculogenic mimicry formation in hepatocellular carcinoma

Vasculogenic mimicry is a highly patterned vascular channel distinguished from the endothelium-dependent blood vessel. Vasculogenic mimicry is lined by highly aggressive tumor cells, and is associated with tumor grade, invasion and metastasis, and poor clinical prognosis. Much attention has been focused on the signaling pathways and the tumor microenvironment needed for vasculogenic mimicry formation, however, the studies on the spacial foundation for vasculogenic mimicry formation are limited. There are many lipid droplets in hepatocellular carcinoma due to steatosis, while increased numbers of lipid droplets also have been reported in many other neoplastic processes. The role of lipid droplets in tumor is still unclear. Based on the similar structural and morphological characteristics between vasculogenic mimicry and lipid droplet, we speculate that the lipid droplets may lay a spacial foundation for vasculogenic mimicry formation by a way of “space placeholder” in HCC. Experimental data and limited clinical literatures support the hypothesis to a certain degree. This hypothesis may provide a new idea for the study of vasculogenic mimicry and also provide a new direction for the functional study of lipid droplets in tumor.     

One‐Step Preparation of Reduction‐Responsive Biodegradable Polymers as Efficient Intracellular Drug Delivery Platforms

Reduction‐responsive biodegradable polymeric micelles based on functional 2‐methylene‐1,3‐dioxepane (MDO) copolymers are developed and investigated for triggered doxorubicin (DOX) release. The MDO‐based copolymers P(MDO‐co‐PEGMA‐co‐PDSMA) are synthesized via the simple one‐step radical ring‐opening copolymerization of MDO, poly(ethylene glycol) methyl ether methacrylate (PEGMA), and pyridyldisulfide ethylmethacrylate (PDSMA). The copolymers can self‐assemble to form micelles in aqueous solution. DOX, a model anticancer drug, is loaded into the micelles with the drug loading content (DLC) of 11.3%. The micelles can be disassembled under a reductive environment (10 × 10^?3m glutathione), which results in a triggered drug release behavior. The glutathione‐mediated intracellular drug release of DOX‐loaded micelles is investigated against A549 cells. Confocal laser scanning microscopy (CLSM) results demonstrated that DOX‐loaded micelles exhibits faster drug release in glutathione monoester (GSH‐OEt)‐pretreated A549 cells, compared with untreated and buthionine sulfoximine (BSO)‐pretreated A549 cells. Based on the facile synthetic strategy, the reduction‐sensitive biodegradable micelles with triggered intracellular drug release are promising for anticancer drug delivery.

     

Synthesis of a Multiblock Copolymer of cis‐1,4‐Polybutadiene and Poly(3‐buten‐1‐ol)

Synthesis of a multiblock copolymer composed of cis‐1,4‐polybutadiene (PBd) segments and poly(3‐buten‐1‐ol) segments is performed via successive hydroboration and oxidation of cis‐1,4/syn‐1,2‐multiblock PBd. The ratio of functionalization can be controlled by changing the amount of the borane reagent. The obtained polymer shows two distinctive glass‐transition temperatures, which correspond to the cis‐1,4‐PBd block and the poly(3‐buten‐1‐ol) block. These thermal properties clearly show that the functionalization of the PBd proceeds keeping the elastic property derived from cis‐1,4 segment.

     

Biomechanical analysis of the acetabular buttress-plate: are complex acetabular fractures in the quadrilateral area stable after treatment with anterior construct plate-1/3 tube buttress plate fixation?

OBJECTIVE:

The acetabular buttress-plate has been widely used in treating difficult cases with satisfying clinical results. However, the biomechanical properties of a postoperative acetabular fracture fixed by the buttress-plate are not clear. The purpose of this study was to evaluate the biomechanical properties of stability after the anterior tube buttress-plate fixation of complex acetabular fractures in the quadrilateral area.

METHODS:

A construct was proposed based on anterior construct plate - 1/3 tube buttress plate fixation for acetabular both-column fractures. Two groups of six formalin-preserved cadaveric pelvises were analyzed: (1) group A, the normal pelvis and (2) group B, anterior construct plate-1/3 tube buttress plate with quadrilateral area fixation. The displacements were measured, and cyclical loads were applied in both standing and sitting simulations.

RESULTS:

As the load was added, the displacements were Ap = 0.013; sitting position: p = 0.009) between groups A and B.

CONCLUSION:

The anterior construct plate - 1/3 tube buttress plate fixation provided a better stable construct for early sitting. The standing mode yielded more significant differences between the groups. Placing a 1/3 tube buttress-plate via an anterior approach is a novel method of providing quadrilateral area support in this setting.     

Wnt信号分子在大鼠中枢神经系统的表达及其共存

目的:通过研究Wnt信号分子在大鼠中枢神经系统(CNS)的表达及分布,以探讨Wnt信号分子在CNS早期发育的可能调控机制,以及Wnt信号分子之间的功能联系.方法:应用免疫组织化学及双标记技术,观察了Wnt信号分子β-catenin、糖原合成酶激酶3β(Gsk-3β)、大肠腺瘤样息肉基因(APC)等关键调控分子在成年大鼠CNS的表达分布、细胞定位及共存关系.结果:免疫组织化学显色显示Gsk-3β阳性细胞多为具有突起的神经元样细胞,其主要分布区域包括新皮层、背内侧丘脑、海马、小脑浦肯野细胞及脑干多个核团.β-catenin与APC在分布模式上与Gsk-3β高度一致.双标记实验显示β-catenin与APC除神经元外,在部分星形胶质细胞也存在表达,而Gsk-3β则主要显示神经元定位.部分β-catenin阳性细胞,特别是室下层及海马区阳性细胞还呈现与神经前体细胞标记物巢蛋白的共存.结论:Wnt信号分子在CNS存在着密切相关的功能联系,同时在不同细胞及组织区域可能还具有其特有的生物效应,与神经前体细胞和神经胶质细胞增殖分化密切相关,对其相关信号机制有待深入研究.     

Blunted growth hormone response to hGRF 1-29 NH2 in patients with non-insulin-dependent diabetes mellitus]

Basal serum growth hormone and response of GH to GRF in 10 patients with noninsulin-dependent diabetes and in 10 control subjects were studied. The basal GH level in NIDDM was higher than that in control subjects. There was a significant difference. After an intravenous bolus of hGRF 1-29 NH2 with the dose of 1 microgram/kg body weight, GH (Peak level-basal level) decreased in NIDDM patients in comparing with control group (P < 0.05). These findings may suggest that the pituitary GH reserve is reduced in patients with NIDDM. There exists some defect in central GH control in diabetics with enhanced somatostatin secretion and abnormal sensitivity of the GH secretion cells to a variety of regulatory factors including GRF, glucose, amino-acids, free fat acid.     

系统性红斑狼疮继发难治性血小板减少的临床特征分析

目的 分析SLE患者合并难治性血小板减少(RLTP)的临床特征及其影响因素.方法 回顾性分析2015年1月至2018年6月经苏州大学附属第一医院风湿免疫科门诊和住院部诊断为SLE合并血小板减少的患者113例,收集患者的病史及实验室检查,分为难治组(RLTP组,25例)和非难治性组(NRLTP,88例),采用t检验、Mann-Whitney检验及χ^2检验方法比较分析2组临床表现、血常规、生化及免疫学等指标,进一步采用非条件Logistic回归分析影响RLTP患者预后的因素以及Kaplan-Meier生存曲线分析RLTP患者的累积生存率.结果 与NRLTP患者比较,RLTP患者的病程更长[72(30,120)个月与38.5(8.5,93)个月,H=-2.401,P=0.016)],神经系统损害(28%与7%,χ^2=8.58,P=0.016)比例更高、出血风险更高[(4.6±1.7)与(3.8±1.3),t=2.548,P=0.012]及病死率更高(8%与0,χ^2=7.167,P<0.01);同时RLTP组抗GP Ⅰ b/Ⅸ阳性率显著高于NRLTP组(27%与4%,χ^2=8.647,P<0.01);采用非条件多因素Logistic回归分析显示,抗GP Ⅰ b/Ⅸ阳性是RLTP的主要影响因素之一.采用Kaplan-Meier生存曲线分析结果显示RLTP组的累积生存率较NLTP组明显降低(χ^2=7.909,P<0.01).结论 RLTP病程长、易合并神经系统损害及抗GPIb/IX阳性率高并且出血风险高及预后差,应早期识别该类患者,调整治疗策略,改善患者预后.     

Expression of SOCS-1 in the liver tissues of chronic hepatitis B and its clinical significance

AIM： To study the expression of suppressor of cytokine signaling-1 （SOCS-1） in the liver tissues of chronic hepatitis 13 （CHB） and the clinical significance of this expression. METHODS： The expression of SOCS-1 in liver tissues of 45 cases of CHB was investigated by immunohistochemical staining, and its correlations with inflammation grades and fibrosis stage were analyzed by SPSS statistics software. RESULTS： The result showed SOCS-1 expressing could be observed in the liver tissue of CriB. The expression of SOCS-1 was mainly distributed near the portal area in the liver tissue of mild inflammation CriB group, and was diffusely distributed in the liver tissue of moderate and severe inflammation groups. SOCS-1 positive stains mainly appear in the hepatocytes, only a few of liver interstitial cells were involved. Inside the hepatocyte, SOCS-1 positive stains are mainly distributed in the plasma. Some of the staining was observed on the membrane. The inclusion bodies in the plasma of hepatocytes were observed occasionally. There were both obvious correlations between the expression of SOCS-1 and the inflammatory grade, and that between the expression of SOCS-1 and the fibrosis stage, CONCLUSION： The distribution of SOCS-1 in the liver tissue of CriB is variable. This expression was correlated with the inflammation grade and fibrosis stage.