Ion Release,Porosity, Solubility,and Bioactivity of MTA Plus Tricalcium Silicate

Introduction

The aim of this study was to evaluate MTA Plus (Prevest Denpro Limited, Jammu, India, for Avalon Biomed Inc) material's properties, namely calcium release, the pH change, solubility, water sorption, porosity, surface morphology, and apatite-forming ability after immersion in simulated body fluid.

Methods

Two tricalcium silicate powders (MTA Plus and ProRoot MTA; Dentsply Tulsa Specialties, Tulsa, OK) and Dycal (Dentsply Caulk, Milford, DE) were tested. After incubation at 37°C and 99% relative humidity, calcium and hydroxyl ion release were tested up to 28 days in deionized water at 37°C. Water absorption, interconnected pores, apparent porosity, and solubility were measured after 24 hours of immersion in deionized water at 37°C. The morphologic and elemental analysis of the materials' surfaces were examined using an environmental scanning electron microscope/energy dispersive x-ray analysis after storage at 37°C for 1–28 days in simulated body fluid using the ISO 23317 method.

Results

All 3 materials created an alkaline pH within 3 hours, which continued for 28 days. MTA Plus had a higher ion release than ProRoot MTA and Dycal; the use of the MTA Plus gel enhanced the initial calcium release and the increase of the pH. Both MTA materials were more porous, water soluble, and water sorptive than Dycal and more bioactive. After aging in simulated body fluid, MTA Plus material caused precipitation of an apparent calcium phosphate layer.

Conclusions

MTA Plus showed improved reactivity and prolonged capability to release calcium and increase the local pH to alkaline values in comparison with ProRoot MTA. These pronounced ion-releasing properties are interlinked with its noticeable porosity, water sorption, and solubility and with the formation of calcium phosphorus minerals. The finer calcium silicate powder may explain the higher ion release, water sorption, porosity, and solubility of MTA Plus compared with ProRoot MTA. For clinicians, MTA Plus represents a lower-cost bioactive tricalcium silicate material with interesting chemical-physical properties that could be a convenient alternative to the conventional calcium silicate mineral trioxide aggregate–like cements.     

不同促排卵方案在多囊卵巢行体外受精-胚胎移植患者中的效果及对相关指标的影响

目的比较不同促排卵方案在多囊卵巢体外受精-胚胎移植(IVF-ET)患者中的效果及对相关指标表达的影响。方法选取56例多囊卵巢IVF-ET患者,随机分为A组(传统长效促性腺激素释放激素激动剂组)28例和B组(来曲唑组)28例。比较2组的促性腺激素(Gn)量、Gn时间、窦卵泡数、受精率、妊娠率、OHSS发生率及不同时间的抗苗勒氏管激素(AMH)水平、性激素水平。结果 B组的Gn量小于A组,Gn时间短于A组,窦卵泡数、受精率及妊娠率均高于A组,OHSS发生率低于A组,不同时间的AMH水平均高于A组,HCG日B组血清LH高于A组,血清E_2低于A组,移植日B组血清P低于A组,差异均有统计学意义(P0.05)。结论来曲唑在多囊卵巢IVF-ET患者中的效果较好,患者相关指标的表达状态也更好。     

Developmental changes in cellular and extracellular structural macromolecules in the secondary palate and in the nasal cavity of the mouse

Vaziri Sani F, Kaartinen V, El Shahawy M, Linde A, Gritli‐Linde A. Developmental changes in cellular and extracellular structural macromolecules in the secondary palate and nasal cavity of the mouse. Eur J Oral Sci 2010; 118: 221–236. © 2010 The Authors. Journal compilation© 2010 Eur J Oral Sci The aim of this study was to analyse the hitherto largely unknown expression patterns of some specific cellular and extracellular molecules during palate and nasal cavity development. We showed that epithelia of the developing palate and the vomerine epithelium express similar sets of structural proteins. With the exception of keratin 15, which becomes barely detectable in the elevated palatal shelves, nearly all of these proteins become upregulated at the presumptive areas of fusion and in the adhering epithelia of the palate and nasal septum. In vivo and in vitro analyses indicated that reduction in the amount of keratin 15 protein is independent of Tgfβ–Alk5 signalling. Foxa1 expression also highlighted the regionalization of the palatal and nasal epithelia. Owing to the lack of reliable markers of the palatal periderm, the fate of peridermal cells has been controversial. We identified LewisX/stage‐specific embryonic antigen‐1 as a specific peridermal marker, and showed that numerous peridermal cells remain trapped in the medial epithelial seam (MES). The fate of these cells is probably apoptosis together with the rest of the MES cells, as we provided strong evidence for this event. Heparan sulphate, chondroitin‐6‐sulphate, and versican displayed dynamically changing distribution patterns. The hitherto‐unknown innervation pattern of the developing palate was revealed. These findings may be of value for unravelling the pathogenesis of palatal clefting.     

Increased transvascular transport of WGA-peroxidase after chronic perinatal stress in the hippocampal microvasculature of the rat

Brain endothelial ultrastructural properties contribute to maintain proper blood-brain barrier (BBB) function. Several physiological and pathological conditions have been shown to alter BBB permeability to blood-borne molecules, acute and chronic stress among them. In the rat, early life stress increased transvascular transport of Evans blue, however, the route of tracer extravasation is not fully known; therefore the aim of the present experiment was to describe the ultrastructural changes in endothelial cells subsequent to chronic perinatal stress in order to ascertain the route for transvascular transport of an electrodense tracer. Pregnant Wistar rats and their litters were used. Four pregnant rats were subjected to forced swimming between gestational days 10 to 20. After delivery, half of the control litters underwent 180 min maternal separation from postnatal day 2 to 20. Controls were kept free of any stress manipulation. At sacrifice between postnatal days 1 to 30 subjects were given intracardially the lectin wheat germ agglutinin conjugated to horseradish peroxidase (WGA-HRP). WGA-HRP stained hippocampi were processed for ultrastructural analysis, transmission electron micrographs were obtained and endothelial ultrastructural parameters quantified using the ImageJ software. Both stress procedures accelerated gross microvessel development by decreasing capillary wall thickness and endothelial microvilli. However, early-life stress also neutralized endothelial glycocalyx, increased vesicle-mediated transport and tended to promote the formation of secondary lysosomes containing endocytosed WGA-HRP vesicles, all parameters of altered endothelial cell function. Tight junction development in both stress groups was similar to the control pups.     

胃泌素释放肽前体融合蛋白的制备及其在肿瘤研究中的应用

目的克隆胃泌素释放肽前体(pro-GRP)基因、构建重组质粒pGEM-T-pro-GRP和表达载体PMS-31b-pro-GRP、在大肠杆菌中热诱导表达并制备融合蛋白。方法从BGC823胃癌细胞中提取总RNA,利用pro-GRP特异引物,扩增人pro-GRP分子的cDNA全长。将pro-GRP基因定向克隆于pGEM-T载体转化JM109,DNA测序鉴定基因序列。将pro-GRP基因定向克隆于原核高效表达载体PMS-31b,转化大肠杆菌POP2136经42℃热诱导表达MS2-pro-GRP融合蛋白。将融合蛋白分离纯化后,十二烷基硫酸钠聚丙烯酰胺凝胶电泳(SDS-PAGE)凝胶鉴定。结果经聚合酶链反应(PCR)扩增成功获得210bp的pro-GRP基因,目的基因序列正确。SDS-PAGE显示热诱导后表达的融合蛋白分子量约为18000。结论成功克隆pro-GRP基因,并表达和纯化了PMS-31b-pro-GRP融合蛋白,为建立pro-GRP检测方法奠定了基础。     

餐后血糖对2型糖尿病诊断的意义

目的通过口服葡萄糖耐量（OGTT）和胰岛素释放（IRT）试验,解析空腹和餐后血糖对糖尿病诊断的意义。方法收集2005年1月—2007年6月,内分泌和代谢科门诊及住院患者共3 588例进行OGTT和IRT检测。以血浆葡萄糖5.6、6.1、7.0mmol/L为空腹血糖切点,7.8、11.1mmol/L为餐后血糖切点,分析患者分布情况以及空腹血糖（FPG）、餐后1h血糖（1 h PG）和餐后2 h血糖（2 h PG）等不同切点对糖尿病诊断的价值。结果依据1999年WHO糖尿病诊断标准,诊断糖尿病患者3097例。其中FPG≥7.0mmol/L者2654例,单独检测2hPG漏诊62例,占2.33%;单独检测1hPG仅漏诊18例,占0.68%,差别有统计学意义（P〈0.001）。2 h PG≥11.1 mmol/L者中FPG〈7.0 mmol/L的占14.60%（443/3 035）;1 h PG≥11.1mmol/L者中FPG〈7.0mmol/L的占14.00%（429/3065）,差别无有统计学意义（P=0.503）。FPG和餐后2hPG均正常202例〔但其中113例存在高胰岛素血症和（或）胰岛素分泌延迟,占55.94%〕,其余289例为糖耐量受损和（或）空腹血糖受损。在1 hPG≥11.1 mmol/L且2 h PG〈11.1 mmol/L的291例中,54例FPG≥7.0mmol/L经复查诊断为糖尿病,另有125例餐后30 min血糖≥11.1 mmol/L者的HOMA指数及胰岛素曲线下面积与FPG5.6～6.1mmol/L而2 h PG≥11.1mmol/L的糖尿病患者接近。结论1 h PG与FPG的一致性不比2 h PG差,且更敏感,提示1 h PG同2 h PG一样,可以作为糖尿病的餐后血糖诊断切点。     

手法松解配合中药薰洗治疗创伤性踝关节粘连临床观察

目的：探讨手法松解配合中药薰洗治疗创伤性踝关节粘连的临床疗效。方法：将创伤性踝关节粘连78例随机分为治疗组39例，对照组39例，对照组常规康复治疗、治疗组手法松解配合中药薰洗进行治疗。结果：治疗组主动及被动背伸、跖屈、内收、外展ROM改善情况明显优于对照组（P〈0．05或P〈0．01=。治疗前后两组AOFAS踝-后足评分比较。治疗组疼痛、功能评分改善情况明显优于对照组（P〈0．05=，治疗组总疗效优于对照组（P〈0．05=。结论：手法松解配合中药薰洗治疗创伤性踝关节粘连有良好疗效，值得临床上推广运用。