Autonomously Bioluminescent Mammalian Cells for Continuous and Real-time Monitoring of Cytotoxicity

Mammalian cell-based in vitro assays have been widely employed as alternatives to animal testing for toxicological studies but have been limited due to the high monetary and time costs of parallel sample preparation that are necessitated due to the destructive nature of firefly luciferase-based screening methods. This video describes the utilization of autonomously bioluminescent mammalian cells, which do not require the destructive addition of a luciferin substrate, as an inexpensive and facile method for monitoring the cytotoxic effects of a compound of interest. Mammalian cells stably expressing the full bacterial bioluminescence (luxCDABEfrp) gene cassette autonomously produce an optical signal that peaks at 490 nm without the addition of an expensive and possibly interfering luciferin substrate, excitation by an external energy source, or destruction of the sample that is traditionally performed during optical imaging procedures. This independence from external stimulation places the burden for maintaining the bioluminescent reaction solely on the cell, meaning that the resultant signal is only detected during active metabolism. This characteristic makes the lux-expressing cell line an excellent candidate for use as a biosentinel against cytotoxic effects because changes in bioluminescent production are indicative of adverse effects on cellular growth and metabolism. Similarly, the autonomous nature and lack of required sample destruction permits repeated imaging of the same sample in real-time throughout the period of toxicant exposure and can be performed across multiple samples using existing imaging equipment in an automated fashion.     

A Laser-induced Mouse Model of Chronic Ocular Hypertension to Characterize Visual Defects

Glaucoma, frequently associated with elevated intraocular pressure (IOP), is one of the leading causes of blindness. We sought to establish a mouse model of ocular hypertension to mimic human high-tension glaucoma. Here laser illumination is applied to the corneal limbus to photocoagulate the aqueous outflow, inducing angle closure. The changes of IOP are monitored using a rebound tonometer before and after the laser treatment. An optomotor behavioral test is used to measure corresponding changes in visual capacity. The representative result from one mouse which developed sustained IOP elevation after laser illumination is shown. A decreased visual acuity and contrast sensitivity is observed in this ocular hypertensive mouse. Together, our study introduces a valuable model system to investigate neuronal degeneration and the underlying molecular mechanisms in glaucomatous mice.     

市售冷却牛肉中主要细菌的常规分离与鉴定

利用常用纯培养的方法, 根据细菌的菌落形态、菌落颜色、革兰氏染色等常见特征, 从市售冷却牛肉中, 选取菌落形态差别比较明显的菌株共32株, 其中保鲜膜包装冷却牛肉样品共12株, 未包装冷却牛肉样品共20株; 同时选取两样品中的优势菌株各4株进行进一步的研究(8株细菌编号为：S01~S08, 其中S01~S04为未包装冷却牛肉样品; S05~S08为保鲜膜包装冷却牛肉样品), 通过ARDRA(Amplified ribosomal DNA restriction analysis) 以及16S rDNA 序列等进行分类研究, 确定该细菌的分类地位, 并结合形态、常规生理生化特性进行鉴定, 确定各细菌所属种。实验表明：S01为假单胞菌属中的恶臭假单胞菌(Pseudomonas putida), S02为希瓦氏菌属下的(Shewanella cincia sp.), 而S03和S05为希瓦氏菌属下的腐败希瓦氏菌(Shewanella putrefaciens), S04为窄食单胞菌属中的嗜麦芽窄食单胞菌(Stenotrophomonas maltophilia), S06为嗜冷杆菌(Psychrobacter sp.), S07为葡萄球菌属中的松鼠葡萄球菌(Staphylococcu sciuri), S08为微杆菌属中的产左聚糖微杆菌(Microbacterium laevaniformans)。证明两样品的共有优势菌为希瓦氏菌属。通过对样品可培养微生物情况进行初步的调查分析, 为冷却肉加工工艺提供一定的理论基础。     

Envejecer sin ver: evaluación del ajuste a la pérdida visual sobrevenida en la vejez

Introduction

The adjustment process to visual impairment can be approached by using theoretical models. The key variables in these models are usually measured by using psychometric instruments. The measurements can be taken from those already existing for the general population or be specifically designed for the visually impaired population. If the chosen measurements are reasonably valid and behave as the model predicts, they can be further used for designing programs that improve the process of adjusting.We describe the identification, adaptation and validation of some theses measurements.

Method

We selected the psychometrics instruments to be used in the research: the Age-Related Vision Loss Scale (AVL) by Horowitz and Reinhardt; the Nottingham Adjustment Scale (NAS) by Dodds, and the Geriatric Depression Scale (GDS) by Brink and Yesavage. The AVL and NAS were adapted for use in Spain. The referred measurements were applied to a sample of 335 respondents together with the Scale of Subjective Wellbeing (EBS), and their psychometric properties were assessed.

Results

The estimated reliabilities were: AVL (0.80), NASA2 (0.87), NASB (0.81), NASC (0.75), NASE (0.87), GDS (0.90). The relationships between the measurements were all in the expected direction, and the magnitude of the convergent-validity coefficients was considered as acceptable.

Conclusions

Our results suggests that the available measurements discussed above are appropriate for assessing the adjustment process, and are useful tools for individual assessment, as well as for designing intervention programs.All the measurements are available in computerized form in www.proyectotarragona.es.     

The Reliability of Tests of Hypotheses when Overdispersed Logistic-Linear Models are Fitted by Maximum Quasi-Likelihood

When overdispersed logistic-linear models are fitted by maximum quasi-likelihood hypotheses can be tested by comparing either the Wald statistic, or the quasi-likelihood score statistic, or the quasi likelihood-ratio statistic, with the approximating null X² distribution. This paper reports a simulation study of the reliability of these tests. Some factors affecting their relative reliabilities are identified. An extended quasi-likelihood ratio test is also considered.     

抗H5N1亚型禽流感病毒血凝素单克隆抗体的制备及鉴定

目的建立稳定分泌抗H5N1亚型禽流感病毒血凝素单克隆抗体的杂交瘤细胞系,为进一步研究禽流感诊断技术奠定基础。方法以纯化的H5亚型禽流感病毒按常规方法免疫BALBc小鼠,最后一次免疫后第3天取其脾细胞与SP20细胞在聚乙二醇作用下融合,用选择性培养、有限稀释法克隆和血凝抑制试验进行筛选,对获得阳性克隆株用ELISA方法进行亚型鉴定,并用37株H5、H7、H9亚型AIV测定其特异性、覆盖性。结果最后获得了3株分泌特异性抗体的杂交瘤细胞,命名为1E5、4A4、4B1,经长期体外培养和冻存后复苏能稳定地分泌抗体。经鉴定,其亚型均为IgG1、kappa链。腹水HI效价1∶210～1∶216,细胞培养上清HI效价1∶26～1∶28。3株杂交瘤所分泌的单克隆抗体均能与本中心保存的全部20株H5亚型禽流感病毒分离株发生反应,而与15株H9亚型禽流感病毒分离株、2株H7亚型禽流感病毒分离株以及H1H4、H6H15亚型禽流感病毒标准毒株均不反应,与鸡新城疫病毒、鹅新城疫病毒、鹅腺病毒和鸡产蛋下降综合征病毒等均无交叉反应。结论所获3株单克隆抗体可用于禽流感病毒特异性诊断试剂的研制。     

Informed Consent and Genetic Information

In the last 25 years writing in bioethics, particularly in medical ethics, has generally claimed that action is ethically acceptable only if it receives informed consent from those affected. However, informed consent provides only limited justification, and may provide even less as new information technologies are used to store and handle personal data, including personal genetic data. The central philosophical weakness of relying on informed consent procedures for ethical justification is that consent is a propositional attitude, so referentially opaque: consent is given to specific propositions describing limited aspects of a situation, and does not transfer even to closely related propositions. Assembling genetic data in databases creates additional difficulties for ethical justification. This is not because genetic information is intrinsically exceptional, but because the merger of genetic and information technologies make it possible to assemble massive quantities of complex information that defeat individuals' best efforts to grasp what is at stake, or to give or withhold informed consent. The future agenda for bioethics will need to take account of both these limitations of appeals to informed consent.     

A Shift Algorithm for Exact Computation in Sequential Tests with Binary Outcome

A simple shift algorithm is described enabling the exact determination of power functions and sample size distributions for a large variety of closed sequential two‐sample designs with a binary outcome variable. The test statistics are assumed to be based on relative frequencies of successes or failures, but the number of interim analyses, the monitoring times, and the continuation regions may be specified as desired. To give examples, exact properties of designs proposed by the program package EaSt (Cytel , 1992) are determined, and plans with interim analyses are considered where decisions are based on the conditional power given the observations obtained so far.