The culture of human skin fibroblasts on microcarriers in the presence of serum substitute: Ultroser G

The effects of the substitution of serum by Ultroser G on human skin fibroblasts cultured on microcarriers were analysed. Cultures could not be established on microcarriers in the presence of Ultroser G. However, microcarrier cultures started in the presence of 10% foetal calf serum, and transferred to 2% Ultroser G after 7 days resulted in high cell densities.     

啤酒酵母的开发应用及其制代可可粉的研究

本文介绍了啤酒酵母营养的成分和医用价值,概述了国内外开发应用啤酒酵母的研究功态,研究了用啤酒酵母加工代可可粉的工艺路线和方法,同时回收了啤酒,测定了代可可粉的营养成分,并用之加工巧克力和可可饮料,结果表明,其效果与天然可可粉类同。     

从绿色荧光蛋白的发现谈如何提出新颖的科研问题

为了使研究生在获得专业知识的同时,还可以依据文献提出新的科研问题,并设计实验方案来解决提出的问题,我们以绿色荧光蛋白为案例教学,谈谈在其发现过程中是如何提出问题以及提出问题所用的思维方式。启发研究生运用求异和置换的思维方式来提出新颖的科研问题,并设计实验来回答提出的问题,从而为研究生完成学术论文奠定良好的基础。     

In vitro cytotoxicity of a novel injectable and biodegradable alveolar bone substitute

The unsaturated polyphosphoester (UPPE) polymer is being investigated as an injectable and biodegradable system for alveolar bone repair in the treatment of periodontal diseases. The incorporation of β-tricalcium phosphate (β-TCP) particles into the UPPE polymer was previously shown to significantly increase the material’s mechanical properties. Moreover, in vitro experiments demonstrated that the UPPE/β-TCP composite was capable of zero-order release of tetracycline for over 2 weeks. In this study, we investigated the in vitro cytotoxicity of each individual component, the resulting cross-linked network and the degradation products of the UPPE/β-TCP composite using an AlamarBlue viability assay. We confirmed that each individual component except β-TCP and the in vitro degradation products of the composite displayed a dose-dependent cytotoxic response. Once cross-linked, however, the composite did not demonstrate an adverse response. Our results suggest that the UPPE/β-TCP composite holds great promise for use as an injectable and biodegradable alveolar bone substitute.     

不同人工代花粉对蜂群群势和生产性能的影响

早春将群势、蜂王年龄和质量基本一致的25群意大利蜜蜂Apis melliferaL.,随机分为5个处理,分别饲喂纯花粉和4种不同的人工代用花粉,观测它们对蜂群群势和生产性能的影响。结果表明,含有添加剂的各代用花粉组与纯花粉组的蜂群的蜂子数量差异均不显著,但均显著高于纯豆粕组(P<0.01);各组产蜜量随着纯花粉所占比例的减少而呈现递减的趋势,但饲喂含有60%花粉+40%豆粕+添加剂1组与纯花粉组没有明显的差异;含有添加剂的各代用花粉组的王台接受率均显著高于纯花粉组(P<0.01);饲喂含有添加剂的各代用花粉组与饲喂纯花粉组相比,王浆产量及蜂王浆中的10-HDA、水分、蛋白质的含量及酸度均没有差异。     

Development of genetically engineered human intestinal cells for regulated insulin secretion using rAAV-mediated gene transfer

Cell-based therapies for treating insulin-dependent diabetes (IDD) can provide a more physiologic regulation of blood glucose levels in a less invasive fashion than daily insulin injections. Promising cells include intestinal enteroendocrine cells genetically engineered to secrete insulin in response to physiologic stimuli; responsiveness occurs at the exocytosis level to regulate the acute release of recombinant insulin. In this work, we established a human cellular model to demonstrate that meat hydrolysate can simultaneously stimulate glucagon-like peptide-1 (GLP-1, an enteroendocrine cell-derived incretin hormone) and recombinant insulin secretion from the engineered human NCI-H716 intestinal cell line. Cells were genetically modified using the recombinant adeno-associated virus (rAAV)-mediated insulin gene transfer. Recombinant cells were then differentiated to display endocrine features, in particular the formation of granule-like compartments. A fusion protein of insulin and enhanced green fluorescence protein (EGFP) was designed to reveal the compartments of localization of the fusion protein and assess its co-localization with endogenous GLP-1. Our work provides a unique human cellular model for regulated insulin release through genetic engineering of GLP-1-secreting intestinal cells, which is expected to be useful for cell-based therapies of IDD.     

Influence of larval rearing diet on the intensive searching behaviour ofHarmonia axyridis [Col.: Coccinellidae] Larvae

The capture of prey by last instar larvae of the aphidophagous coccinellidHarmonia axyridis Pallas (Col.,Coccinellidae) modified larval movement so that extensive search was replaced by intensive search. The continuous rearing of this species on eggs ofEphestia kühniella Zell. (Lep.,Pyralidae) or on the aphidAcyrthosiphon pisum Harris (Homopt.,Aphidae) led to conditioning. Only larvae that ate the same prey as they were reared on, adopted intensive searching movements after feeding. Using larvae reared on substitute prey in biological control systems may decrease the efficiency of the released predators.     

Biocompatibility Studies of a New Biosynthetic Dermal Substitute Based on Collagen/Hyaluronan Conjugate

The use of glycosaminoglycans (GAGs) as the second macromolecular component with collagen for the membrane preparation is based on the idea to create a biodegradable scaffold for new tissue. A hybrid collagen/hyaluronan membrane with specific bubble macrostructure was designed to serve as a synthetic dermal substitute. The objectives were to explain the two questions: what is the local biological response to the implanted membrane, and what is its reconstruction rate in tissue. The histological study proved low irritability, good compatibility, ingrowth of autologous tissue starting on day 7 post implantation, and resorption within four weeks. The major part of the implant was replaced by autologous tissue at the end of three weeks post implantation. The overall local biological response to implant was very good.     

Biocompatibility studies of modified collagen/Hyaluronan membranes after implantation

Two varieties of collagen/sodium hyaluronan membranes were used asdermal substitutes in a biocompatibility implantation study on rats. In ordertoimprove especially the physical and mechanical properties of the material, themembranes were chemically modified using a combination ofhexamethylenediisocyanate (HMDC) as a crosslinker and polyoxy-ethylene (POE) asa spacer. According to both macroscopic and microscopic histologicalobservations, the membranes were well accepted by the surrounding host tissueinall the animals. No major differences in relation to the outgrowth of thematerial by host tissue have been observed between the implant varieties A andB. The most important finding was that no pathological changes or importantalterations of the host tissues were detected.