Operation of a Benchtop Bioreactor

Fermentation systems are used to provide an optimal growth environment for many different types of cell cultures. The ability afforded by fermentors to carefully control temperature, pH, and dissolved oxygen concentrations in particular makes them essential to efficient large scale growth and expression of fermentation products. This video will briefly describe the advantages of the fermentor over the shake flask. It will also identify key components of a typical benchtop fermentation system and give basic instruction on setup of the vessel and calibration of its probes. The viewer will be familiarized with the sterilization process and shown how to inoculate the growth medium in the vessel with culture. Basic concepts of operation, sampling, and harvesting will also be demonstrated. Simple data analysis and system cleanup will also be discussed.     

新疆地区家庭肠内营养应用情况分析

目的:随着新疆地区医疗技术的进步,进行家庭肠内营养支持的患者越来越多.本研究旨在了解新疆地区家庭肠内营养实施现状,以便提出针对性建议.方法:患者出院时,进行肠内营养指导,教育.详细记录患者信息,患者出院后进行电话跟踪随访,出院后,由营养科专人按既定计划对病人进行随访,于病人出院后3天、15天进行电话随访,对于长期HEN支持的病人,以后每月1次.了解肠内营养使用情况并针对遇到的问题给出专业建议.结果:使用的肠内营养制剂包括商品化制剂、自制制剂及二者的联合使用.66.9％的患者使用注射器输注.常见的问题是堵管和肠内营养相关腹泻.结论:在科学指导下,家庭营养支持是安全可行的.通过我们近几年在家庭肠内营养所开展的工作,可以看出在科学指导下,患者及亲属的家庭护理能力将得到提高,家庭营养支持是安全可行的,同时在很大程度上减少了病人的治疗费用和负担.相信随着人民生活水平的不断提高和社会医疗保险的改革,HEN会更加普及.     

不同制剂中相同中草药薄层色谱鉴别探讨

目的探讨不同制剂中相同中药材统一鉴别的可行性。方法采用薄层色谱法,取不同制剂适量,按统一方法制备供试液、层析条件、显色与检视斑点。结果多种含大黄、人参的制剂,薄层色谱斑点清晰明显。结论本实验方法可行,在不同制剂中相同药材鉴别有较统一的方法为好。     

Toxicological Study and Oxidative Stress Evaluation for Safety Assessment of Xylanase Preparations in Wistar Rats

Acute and 90‐day subchronic oral toxicity studies were conducted to establish the safety evaluation of xylanases preparations. A potential oxidative stress evaluation was also performed through testing the generation of oxidative radicals, depletion of antioxidants via oxidative modification of lipids, proteins and DNA of organ cells. During the subchronic oral toxicity study, no mortality was observed, obvious treatment‐related clinical signs and urinalysis parameters were in normal range. Differences in some hematological parameters, biochemistry, relative organ weight, and histopathology examinations between the treated group and the control group were not judged to be adverse. Our results indicated that the no‐observed‐adverse‐effect level for xylanases was 1,500 TXU/kg/day and the plasma antioxidant assays showed that these xylanases did not produce free‐radicals nor oxidative injuries. On the basis of the bacterial reverse mutation assay data, it is concluded that the expressed xylanase in Pichia pastoris do not present any mutagenic potential when tested in relevant genotoxicological assays.     

Isolation of Viable Multicellular Glands from Tissue of the Carnivorous Plant,Nepenthes

Many plants possess specialized structures that are involved in the production and secretion of specific low molecular weight compounds and proteins. These structures are almost always localized on plant surfaces. Among them are nectaries or glandular trichomes. The secreted compounds are often employed in interactions with the biotic environment, for example as attractants for pollinators or deterrents against herbivores.Glands that are unique in several aspects can be found in carnivorous plants. In so-called pitcher plants of the genus Nepenthes, bifunctional glands inside the pitfall-trap on the one hand secrete the digestive fluid, including all enzymes necessary for prey digestion, and on the other hand take-up the released nutrients. Thus, these glands represent an ideal, specialized tissue predestinated to study the underlying molecular, biochemical, and physiological mechanisms of protein secretion and nutrient uptake in plants. Moreover, generally the biosynthesis of secondary compounds produced by many plants equipped with glandular structures could be investigated directly in glands.In order to work on such specialized structures, they need to be isolated efficiently, fast, metabolically active, and without contamination with other tissues. Therefore, a mechanical micropreparation technique was developed and applied for studies on Nepenthes digestion fluid. Here, a protocol is presented that was used to successfully prepare single bifunctional glands from Nepenthes traps, based on a mechanized microsampling platform. The glands could be isolated and directly used further for gene expression analysis by PCR techniques after preparation of RNA.     

MR Molecular Imaging of Prostate Cancer with a Small Molecular CLT1 Peptide Targeted Contrast Agent

Tumor extracellular matrix has abundance of cancer related proteins that can be used as biomarkers for cancer molecular imaging. In this work, we demonstrated effective MR cancer molecular imaging with a small molecular peptide targeted Gd-DOTA monoamide complex as a targeted MRI contrast agent specific to clotted plasma proteins in tumor stroma. We performed the experiment of evaluating the effectiveness of the agent for non-invasive detection of prostate tumor with MRI in a mouse orthotopic PC-3 prostate cancer model. The targeted contrast agent was effective to produce significant tumor contrast enhancement at a low dose of 0.03 mmol Gd/kg. The peptide targeted MRI contrast agent is promising for MR molecular imaging of prostate tumor.     

Models and Methods to Evaluate Transport of Drug Delivery Systems Across Cellular Barriers

Sub-micrometer carriers (nanocarriers; NCs) enhance efficacy of drugs by improving solubility, stability, circulation time, targeting, and release. Additionally, traversing cellular barriers in the body is crucial for both oral delivery of therapeutic NCs into the circulation and transport from the blood into tissues, where intervention is needed. NC transport across cellular barriers is achieved by: (i) the paracellular route, via transient disruption of the junctions that interlock adjacent cells, or (ii) the transcellular route, where materials are internalized by endocytosis, transported across the cell body, and secreted at the opposite cell surface (transyctosis). Delivery across cellular barriers can be facilitated by coupling therapeutics or their carriers with targeting agents that bind specifically to cell-surface markers involved in transport. Here, we provide methods to measure the extent and mechanism of NC transport across a model cell barrier, which consists of a monolayer of gastrointestinal (GI) epithelial cells grown on a porous membrane located in a transwell insert. Formation of a permeability barrier is confirmed by measuring transepithelial electrical resistance (TEER), transepithelial transport of a control substance, and immunostaining of tight junctions. As an example, ~200 nm polymer NCs are used, which carry a therapeutic cargo and are coated with an antibody that targets a cell-surface determinant. The antibody or therapeutic cargo is labeled with ¹²⁵I for radioisotope tracing and labeled NCs are added to the upper chamber over the cell monolayer for varying periods of time. NCs associated to the cells and/or transported to the underlying chamber can be detected. Measurement of free ¹²⁵I allows subtraction of the degraded fraction. The paracellular route is assessed by determining potential changes caused by NC transport to the barrier parameters described above. Transcellular transport is determined by addressing the effect of modulating endocytosis and transcytosis pathways.     

Proteolytic Activity in Commercial Triacylglycerol Hydrolase Preparations

The proteolytic activity of 34 commercial lipase preparations (CLP) was determined using a labeled casein substrate. Only three CLP were free from proteolytic activity. Porcine pancreatic lipases exhibited levels of proteolytic activity comparable to or greater than that of a reference porcine trypsin. Bacterial lipases contained up to 10% of the proteolytic activity of commercial trypsin. Proteolytic activities in lipases from fungal species were present at low levels (<1% of the activity in trypsin). Among preparations of fungal origin, lipases from Aspergillus niger and Mucor javanicus were highest in proteolytic activity; Aspergillus oryzae and Pseudomonas cepacia lipases were lowest. Proteins in CLP were separated by non-denaturing PAGE; between 4 and 17 protein bands in the range &#104 6.5- &#83 200 kDa were observed. With the exception of a single pair of Rhizomucor miehei lipases, the distribution of apparent molecular weights (AMW) was unique to each preparation. Bands of caseinolytic activity in commercial lipases were visualized by applying a zymographic technique. CLP contained between 0 (P. cepacia lipases) and 6 (porcine pancreas lipase and Rhizopus oryzae lipase) discrete proteolytic bands. Common themes of proteolytic AMW emerged, including 21-23 kDa and 30-35 kDa bands.     

茶尺蠖病毒杀虫剂田间使用技术的研究

茶尺蠖病毒杀虫剂应在每年茶尺蠖第1、2代和第5、6代的1～2龄幼虫期使用.在7.5×109 ～ 15.0×109 PIB/hm2的使用剂量下,幼虫期的防治效果可达98%以上.采用不同的喷雾器、不同的用水量及不同的喷施方式喷施,对防治效果无影响.但挑治和丛面喷施可大幅度节约防治成本费.     

茶尺蠖病毒杀虫剂田间使用技术的研究

茶尺蠖病毒杀虫剂应在每年茶尺蠖第1、2代和第5、6代的1～2龄幼虫期使用。在7.5×10~9～15.0×10~9PIB/hm~2的使用剂量下,幼虫期的防治效果可达98％以上。采用不同的喷雾器、不同的用水量及不同的喷施方式喷施,对防治效果无影响。但挑治和丛面喷施可大幅度节约防治成本费。