牙龈间充质干细胞递送支架载体的研究进展

组织工程技术通过利用支架材料、种子细胞、生长因子以达到修复或再生组织器官的目的。支架材料的作用是为种子细胞提供机械支撑并且保护细胞免受体内有害微环境的影响。因此,选择或制备适当的支架材料是组织工程中的关键一步。近年来,将支架材料和牙龈间充质干细胞(gingival mesenchymal stem cells,GMSCs)联合应用于组织工程的研究逐渐走向成熟。本文就组织工程中牙龈间充质干细胞递送支架载体的研究现状进行综述,以期为GMSCs组织工程递送支架载体材料的开发和选择提供思路。     

Effects of the loss and reconstruction of molar occlusal support on memory retrieval and hippocampal neuron density in rats

PurposeAnimal experiments have shown that the loss of occlusal support causes impairments in spatial cognition. Many reports have focused on the memory encoding process, and only few studies have investigated the effect on memory retrieval. This study aimed to examine the effects of both the loss and reconstruction of occlusal support on the memory retrieval process and on the number of hippocampal pyramidal cells.MethodsThe experimental animals were divided into a molarless group, in which molars were extracted, a denture-wearing molarless group with experimental dentures inserted after molar extraction, and a control group. Radial maze trials were performed for 20 consecutive days (acquisition phase). The rats were tested on long-term memory retention following the acquisition phase in eight trials every five days, and in an additional trial 20 days later (probe phase).ResultsThe denture-wearing molarless group showed higher levels of spatial learning and memory than the molarless group. There were no significant differences in memory retrieval during the probe phase between the denture-wearing molarless and the control group. The molarless group showed significantly worse spatial learning and memory and had fewer neurons in the hippocampus than the control group.ConclusionsOur results suggest that the loss of occlusal support decreases the number of pyramidal cells in the hippocampus and impairs memory decoding and retrieval. However, this effect is suppressed by the reconstruction of occlusal support.     

Objective evaluation of abutment tooth preparation for preformed metal crowns for primary molars in Japanese preclinical training

Evaluation of abutment tooth shape for preformed metal crowns for primary teeth in preclinical training depends on the subjective opinion of the instructor providing the training. Thus, the student's grade will likely vary according to teacher grading. In this study, we explored the potential for objective evaluation by comparing evaluations performed by teaching personnel (teacher grading) of abutment teeth for preformed metal crowns for primary teeth prepared by students at a dental school with evaluation by a three-dimensional (3D) laser morphometric system (system grading). The subjects of the evaluations were 139 abutment teeth for preformed metal crowns for primary teeth that had been prepared by fourth-year students at Asahi University School of Dentistry during preclinical pediatric dentistry training. A tooth prepared by a teacher following instruction criteria was used as the reference tooth, and system grade points were calculated from deductions made for insufficient and excessive cutting. Teacher grade points varied among teachers. We found that teachers prioritized contours of the margin, buccal and lingual sides, and adjacent surfaces in their evaluations. System grading showed that most students carried out insufficient cutting. The mean (SD) teacher and system grade points were 57.7 (9.7) and 75.7 (4.7), respectively, and these grade points were positively correlated (r = 0.500). System grading provides a simple 3D visual assessment of insufficient and excessive cutting that can be used for instructing students.     

翻转课堂教学法在天然药物化学实验中的应用

目的利用翻转课堂教学法改进传统的天然药物化学实验课教学模式,提高该课程的教学效果。方法从实验教学的课程设计与开发,课前自主学习、课中内化及课后评估和讨论等环节进行了一系列的探讨与改革。结果翻转课堂教学模式为解决学生长期以来在天然药物化学实验课中缺乏主动参与性、探索性等问题提供一剂良方。结论在天然药物化学实验课教学中引入翻转课堂教学模式的初步探索为天然药物化学实验课的改革提供了依据和思路。     

含功能性油的水飞蓟宾超饱和自纳米乳的制备与体外评价

目的制备含功能性油的水飞蓟宾超饱和自纳米乳(SLB-S-SNEDDS),并对其进行表征及体外评价研究,以提高难溶性药物水飞蓟宾的生物利用度。方法铁氢化钾还原力与1,1-二苯基-2-苦肼基(DPPH)自由基清除实验筛选功能性油脂;伪三元相图考察乳化剂乳化能力;测定粒径、多分散指数(PDI)、Zeta电位等考察混合油相比例与载药量;相容性与溶出度实验筛选促过饱和物质并考察其质量浓度;从外观、粒径分布、自乳化效率、形态学等方面表征SLB-S-SNEDDS,并进行溶出度、抗氧化能力、细胞毒性等体外评价。结果所得SLB-S-SNEDDS处方为(1)小麦胚芽油/Capryol 90-Cremophor ELP-Transcutol HP与(2)沙棘籽油/Capryol 90-Cremophor ELP-Transcutol HP,1 g基质(包含0.043 g小麦胚芽油或沙棘籽油、0.387 g Capryol 90、0.380 g Cremophor ELP、0.190 g Transcutol HP),水飞蓟宾的添加量为各组分平衡溶解度之和的20%,Soluplus的添加量为上述总质量的0.1%。小麦胚芽油、沙棘籽油体系分别为淡黄色、亮黄色透明状均一液体,2种体系自乳化分散后均呈近球形白色扁平乳滴,粒径约为50 nm,乳化时间均为65 s。与药物原料及SLB-SNEDDS相比,SLB-S-SNEDDS中水飞蓟宾的累积溶出率8h内均维持在85%～110%,表明该体系能够显著提高药物的溶出度。SLB-S-SNEDDS与铁氰化钾反应后的吸光度(A值0.452～0.782,0.488～0.765)以及DPPH自由基清除率(39.09%～96.02%,30.54%～89.20%)均高于相应质量浓度下水飞蓟宾原料的A值与清除率(0.411～0.760,22.89%～63.21%),表明2种处方体系均能提高水飞蓟宾的抗氧化能力。细胞毒性实验结果显示,在5、10μmol/L药物浓度下,水飞蓟宾原料组、水飞蓟宾S-SNEDDS组及其相应的空白S-SNEDDS组细胞生存率均90%,说明SLB-S-SNEDDS及其所用辅料对人克隆结肠腺癌细胞(Caco-2)毒性较小、安全性较好。结论制备的含功能性油SLB-S-SNEDDS在提高水飞蓟宾累积溶出率的同时,增强了其抗氧化能力,为将超饱和自纳米乳(S-SNEDDS)用于改善难溶性药物水溶性及其生物活性提供有益参考。     

Antimicrobial and antileukemic effects: in vitro activity of Calyptranthes grandifolia aqueous leaf extract

ABSTRACT

Natural products are still a promising source of bioactive molecules. Food and Drug Administration data showed that approximately 49% of the approved molecules originate naturally or chemically-resemble these substances, of which more than 70% are being used in anticancer therapy. It is noteworthy that at present there are no scientific studies to prove the effectiveness and safety of a number of plants used in folk medicine such as in the case of Calyptranthes grandifolia O. Berg (Myrtaceae) originally from South America. The aim of the present study was to determine the biological potential and toxicological effects of the aqueous leaf extract of C. grandifolia. The main detected phytoconstituents were condensed tannins and flavonoids and a high quantity of polyphenols. Regarding the antimicrobial potential, the extract exerted inhibitory activity against Pseudomonas aeruginosa. The results also revealed the extract induced DNA damage in a concentration-dependent manner in RAW 264.7 cells. In addition, C. grandifolia produced cytotoxicity in leukemia cell lines (HL60 and Kasumi-1) without affecting isolated human lymphocytes but significantly inhibited JAK3 and p38α enzyme activity. Taken together, these findings add important information on the biological and toxicological effects of C. grandifolia, indicating that aqueous extract may be a source of natural antimicrobial and antileukemic constituents.     

Mesenchymal stem cells from orthodontic premolar teeth

BackgroundConsidering the limitations in isolating Bone Marrow Mesenchymal Stem Cells (BMSCs), alternate sources of Mesenchymal Stem Cells (MSCs) are being intensely investigated. This study evaluated dental pulp MSCs (DP-MSCs) isolated from orthodontically extracted premolar teeth from a bone tissue engineering perspective.MethodsMSCs isolated from premolar teeth pulp were cultured and studied using BMSCs as the control. Flow cytometry analysis was performed for the positive and negative MSC markers. Multilineage differentiation focusing on bone regeneration was evaluated by specific growth induction culturing media and by alkaline phosphatase (ALP) activity. Data were compared by repeated measurement analysis of variance and Student's t-test at a p value <0.05.ResultsProliferation rate, population doubling time, and colony formation of DP-MSCs were significantly higher (p < 0.001) than BMSCs. More than 85% of DP-MSCs expressed CD44, CD73, CD90, CD105, and CD166. Negative reaction was found for CD11b CD33, CD34, and CD45. Positive reaction was displayed by 7.2% of cells for early MSC marker, Stro-1. Both the cell populations differentiated into adipogenic, osteogenic, and chondrogenic lineages, with adequate ALP expression.ConclusionBecause DP-MSCs from orthodontic premolars hold a neural crest/ectomesenchymal ancestry, its prudent growth characteristics and multilineage differentiation open up exciting options in craniofacial tissue engineering.     

天灸罐联合少腹逐瘀汤治疗寒凝血瘀型原发性痛经临床观察

目的:观察天灸罐联合少腹逐瘀汤治疗寒凝血瘀型原发性痛经的临床疗效。方法:将90例寒凝血瘀型原发性痛经随机分为治疗组45例和对照组45例。对照组予少腹逐瘀汤治疗,治疗组在此基础上加用天灸罐治疗,均连续治疗5个月经周期。参照COX痛经症状量表(the Cox Menstrual Symptom Scale,CMSS)进行评价;测定两组治疗前后外周血中前列腺素F2a(Prostaglandin F2a,PGF2a)含量;比较两组痛经临床疗效。结果:总有效率组间比较,差异有统计学意义(P<0.05)。两组CMSS时间、程度及PGF2a含量治疗前后组内比较及治疗后组间比较,差异均具有统计学意义(P<0.05)。结论:天灸罐联合少腹逐瘀汤治疗寒凝血瘀型原发性痛经效果良好。