Microspheres of essential oil in polylactic acid and poly(methyl methacrylate) matrices and their blends

This study is focussed on micro-encapsulation of essential oils in polylactic acid (PLA) and a poly(methyl methacrylate) (PMMA) matrix as well as blends of the same. Microspheres were prepared by the solvent evaporation technique and characterised by scanning electron microscopy (SEM), differential scanning calorimetry (DSC) and Fourier transform infra-red spectroscopy (FTIR). The encapsulation efficiencies and release profiles of the essential oils were studied by gas chromatography mass spectrometry (GC-MS) and head-space solid-phase microextraction GC-MS, respectively. Furthermore, the microspheres were tested for antibacterial activity against both Gram-negative and Gram-positive bacterial strains.

The results showed that the microspheres compositions (PLA/PMMA ratio) have significant effect on their characteristics. The process adopted for preparing the microspheres promoted formation of spherical particles at the sizes of 1.5–9.5?µm. The highest encapsulation efficiency of the prepared microspheres was observed in systems consisting of linalool (81.10?±?10.0?wt. % for PLA system and 76.0?±?3.3?wt. % for PMMA system). Confirmation was also made that the release rate of the microspheres was affected by the size of the same.     

股骨转子间骨折的稳定性重建概念演化与研究进展

目的总结近年来股骨转子间骨折在稳定性重建方面的概念演化与研究进展。方法查阅国内外相关文献并结合自身经验，从股骨转子间骨折的解剖特点、稳定型骨折与不稳定型骨折分类、稳定性复位与不稳定性复位、术中加压初始稳定与术后滑动二次稳定、内固定术后稳定性评估、早期下地站立负重等方面进行总结分析。结果股骨转子间骨折发生于股骨颈干骺端转换区，具有天然的内翻不稳定倾向。骨折复位质量是影响后续内固定物安放的最重要前提因素。判断骨折复位质量有对线和对位两方面，对线采用 Garden 指数；在对位方面，随着皮质对位理念（正性、中性、负性）的提出，特别强调前内侧皮质的相互砥住支撑（解剖、正性），是获得骨折稳定性复位的关键，而不再强调后内侧小转子骨块的作用。术后影像学的稳定性评分为早期下地站立负重提供了量化指标。但术中的前内侧皮质支撑复位，在术后头颈骨块滑动获得二次稳定的过程中，仍有皮质对位丢失现象，需研究其危险因素和防范措施。结论股骨转子间骨折在取得良好对线的基础上，只要获得了前内侧皮质的相互砥住和支撑，并用内固定器械维持住，就获得了术后稳定性。术后稳定性评分优良者，可以安全地早期下地负重、站立行走活动。     

Effect of stromal cell-derived factor-1/CXCR4 axis in neural stem cell transplantation for Parkinson’s disease

Previous studies have shown that neural stem cell transplantation has the potential to treat Parkinson’s disease,but its specific mechanism of action is still unclear.Stromal cell-derived factor-1 and its receptor,chemokine receptor 4(CXCR4),are important regulators of cell migration.We speculated that the CXCR4/stromal cell-derived factor 1 axis may be involved in the therapeutic effect of neural stem cell transplantation in the treatment of Parkinson’s disease.A Parkinson’s disease rat model was injected with 6-hydroxydopamine via the right ascending nigrostriatal dopaminergic pathway,and then treated with 5μL of neural stem cell suspension(1.5×104/L)in the right substantia nigra.Rats were intraperitoneally injected once daily for 3 days with 1.25 mL/kg of the CXCR4 antagonist AMD3100 to observe changes after neural stem cell transplantation.Parkinson-like behavior in rats was detected using apomorphine-induced rotation.Immunofluorescence staining was used to determine the immunoreactivity of tyrosine hydroxylase,CXCR4,and stromal cell-derived factor-1 in the brain.Using quantitative real-time polymerase chain reaction,the mRNA expression of stromal cell-derived factor-1 and CXCR4 in the right substantia nigra were measured.In addition,western blot assays were performed to analyze the protein expression of stromal cell-derived factor-1 and CXCR4.Our results demonstrated that neural stem cell transplantation noticeably reduced apomorphine-induced rotation,increased the mRNA and protein expression of stromal cell-derived factor-1 and CXCR4 in the right substantia nigra,and enhanced the immunoreactivity of tyrosine hydroxylase,CXCR4,and stromal cell-derived factor-1 in the brain.Injection of AMD3100 inhibited the aforementioned effects.These findings suggest that the stromal cell-derived factor-1/CXCR4 axis may play a significant role in the therapeutic effect of neural stem cell transplantation in a rat model of Parkinson’s disease.This study was approved by the Animal Care and Use Committee of Kunming Medical University,China(approval No.SYXKK2015-0002)on April 1,2014.     

温阳解毒化瘀颗粒对肝衰竭IETM大鼠TLR4 mRNA,TNF-α及肝细胞凋亡的影响

目的:研究Toll样受体4(TLR4) mRNA及其下游炎性因子肿瘤坏死因子-α(TNF-α)与肝衰竭肠源性内毒素血症(IETM)大鼠肝细胞凋亡的关系,并探索温阳解毒化瘀颗粒对内毒素介导的肝细胞凋亡的调控机制。方法:SPF级雄性SD大鼠85只,随机分为正常组,模型组,TLR4单克隆抗体组和温阳解毒化瘀颗粒组(8.925 g·kg^-1)。采用D-半乳糖胺(D-Gal)腹腔注射建立肝衰竭IETM模型,TLR4单克隆抗体组和温阳解毒化瘀颗粒组在造模前5 d给予温阳解毒化瘀颗粒溶液灌胃,正常组、模型组以等容积蒸馏水代替,直至处死。各组分别在24,48,72 h随机处死大鼠并采集标本。检测24,48,72 h各组时间点血清丙氨酸氨基转移酶(ALT),天门冬氨酸氨基转移酶(AST)水平,苏木素-伊红(HE)染色观察肝组织病理变化,实时荧光定量聚合酶链式反应(Real-time PCR)检测肝组织TLR4 mRNA表达,酶联免疫吸附测定法(ELISA)检测肝组织TNF-α表达,流式细胞仪检测肝细胞凋亡率。结果:与正常组比较,模型组ALT,AST升高,肝组织病理损伤程度明显加重,TLR4mRNA,TNF-α表达均增高(P<0.05,P<0.01),肝细胞凋亡率明显上升(P<0.05,P<0.01);与模型组比较,温阳解毒化瘀颗粒组ALT,AST显著降低(P<0.01),肝组织病理损伤程度明显减轻(P<0.05),TLR4 mRNA,TNF-α表达显著下降(P<0.01),肝细胞凋亡率亦显著降低(P<0.01)。结论:TLR4 mRNA,TNF-α在肝衰竭时与肝细胞凋亡呈正相关,温阳解毒化瘀颗粒能够改善肝衰竭IETM大鼠肝功能,减轻肝细胞损伤,减少肝细胞凋亡,其机制可能与其下调肝脏TLR4 mRNA表达,抑制TNF-α释放,降低肝细胞凋亡率有关。     

Microinjection of a growth factor cocktail affects activated microglia in the neocortex of adult rats

Microglia, as the resident immune cells in the central nervous system, play important roles in regulating neuronal processes, such as neural excitability, synaptic activity, and apoptotic cell clearance. Growth factors can activate multiple signaling pathways in central nervous system microglia and can regulate their immune effects, but whether growth factors can affect the morphological characteristics and ultrastructure of microglia has not been reported. After microinjecting 300 nL of a growth factor cocktail, including 10 μg/mL epidermal growth factor, 10 μg/mL basic fibroblast growth factor, 10 μg/mL hepatocyte growth factor and 10 μg/mL insulin-like growth factor into adult rat cortex, we found that the number of IBA1-positive microglia around the injection area increased significantly, indicating local activation of microglia. All CD68-positive labeling co-localized with IBA1 in microglia. Cell bodies and protrusions of CD68-positive cells were strongly attached to or were engulfing neurons. Characteristic huge phagosomes were observed in activated phagocytes by electron microscopy. The phagosomes generally included non-degraded neuronal protrusions and mitochondria, yet they contained no myelin membrane or remnants, which might indicate selective phagocytosis by the phagocytes. The remnant myelin sheath after phagocytosis still had regenerative ability and formed "myelin-like" structures around phagocytes. These results show that microinjection of a growth factor cocktail into the cerebral cortex of rodents can locally activate microglia and induce selective phagocytosis of neural structures by phagocytes. The study was approved by the Institute of Laboratory Animal Science, Beijing Institute of Basic Medical Sciences(approval No. IACUC-AMMS-2014-501) on June 30, 2014.     

Resistin is elevated in cystic fibrosis sputum and correlates negatively with lung function

Background

Resistin is an immunometabolic mediator that is elevated in several inflammatory disorders. A ligand for Toll-like receptor 4, resistin modulates the recruitment and activation of myeloid cells, notably neutrophils. Neutrophils are major drivers of cystic fibrosis (CF) lung disease, in part due to the release of human neutrophil elastase- and myeloperoxidase-rich primary granules, leading to tissue damage. Here we assessed the relationship of resistin to CF lung disease.