絮状单位测定与小鼠体内中和试验法检测TAT效价的比较

目的为了更好地进行生产质量控制,快速准确地测定破伤风抗毒素(TAT)效价,以统计分析絮状单位测定法(体外法)和小鼠中和试验法(体内法)测定TAT效价的相关性。方法对2010—2013年破伤风抗毒素生产过程中的原料血浆、原液的絮状单位值与小鼠中和效价进行了统计分析和比较。结果体外法和体内法检测TAT原料血浆和原液效价的相关系数分别为r血浆=0.794 3,P0.001和r原液=0.901 6,P0.001,均呈显著性正相关。结论体外法可指导或替代体内法TAT效价测定应用于生产过程中间品的质量控制。     

化妆品眼刺激试验替代方法标准化与展望

眼刺激试验是化妆品安全评价的主要测试项目,目前正尝试建立代替传统动物实验的体外方法,这些方法处于研发、验证和认可的不同阶段。尽管还没有单一体外试验能完全替代兔眼实验,但系统分析替代方法建立的原理、科学相关性和标准化程度的不同,有助于合理选择运用体外方法指导化妆品眼刺激的标识分类、质量检验、产品开发和机制研究。     

乌梅酸枣仁提取物对人工感染鸡大肠杆菌病的防治效果

目的实验室评价乌梅酸枣仁提取物对鸡致病性大肠杆菌病的疗效。方法根据前期研究自拟乌梅酸枣仁提取物配方,以体外试管二倍稀释法测定其最小抑菌浓度（minimal inhibitory concentration,MIC）,建立鸡致病性大肠杆菌病模型,评价其预防和治疗鸡大肠杆菌病疗效。结果体外试验显示其最小抑菌浓度为12.5 mg/mL;人工感染鸡大肠杆菌病模型显示预防试验中乌梅酸枣仁提取物高、中、低剂量组、利好对照组、感染对照组的成活率分别为50%、70%、50%、60%、10%;肝脏细菌检出率均为100%。治疗试验中上述各组成活率分别为62.5%、50%、37.5%、62.5%、25%;肝脏细菌检出率均为100%。结论体外、体内试验结果表明,乌梅酸枣仁提取物能有效减少人工感染后的临床症状,保护率为50%～70%,推荐使用剂量为200 mg/kg体重,可以替代部分抗生素防治此病。     

皮肤刺激实验替代模型的研究新进展

皮肤刺激性是日常使用化妆品最常见的不良反应之一。人类健康相关产品危险性评价常做皮肤刺激性实验,皮肤刺激性试验是化妆品原料及产品安全性评价的主要项目。传统皮肤刺激试验采用实验动物进行,2013年3月11日欧盟已经禁止销售基于动物实验研发的化妆品原料及产品.随着组织工程技术和现代生物技术的发展,多种替代动物试验的体外模型被开发和应用,新的的皮肤刺激物陆续被发现。欧盟多采纳重组人表皮实验方法作为新体外皮肤实验指南(包括模型Episkin和模型Epiderm),随着体外模型重建技术的不断改善,不仅拓展了皮肤模型的临床应用范围,也必然推动新的敏感而特异的皮肤标志物的发现和应用。     

人促卵泡激素体外生物学活性测定方法的建立

目的:建立人促卵泡激素(FSH)体外生物学活性检测方法,并对方法进行验证。方法:以人卵巢颗粒细胞KGN为基质细胞,用不同浓度的FSH与KGN细胞表面的FSH受体结合,刺激细胞产生不同浓度的孕酮,通过测定细胞培养上清中的孕酮含量来评价FSH的生物学活性,结果用国际标准品进行校正;对方法的专属性、线性与范围、回收率、精密度、耐用性进行验证;对市售FSH产品进行检测,并与传统动物体内活性检测结果进行比较。结果:KGN细胞对FSH有很好的剂量反应关系,方法专属性符合要求;线性范围为0.1~200 ng/m L,相关系数R2≥0.99;回收率为80%~120%;经3次重复测定,3批市售样品和3批自制样品的活性分别为(13.4±0.4)~(13.5±0.8)和(12.9±0.7)~(14.3±1.2)IU/μg,变异系数在15%之内;结果显示该方法有很好的耐用性。测定3批市售重组人FSH产品和1批尿源FSH国家标准品,其体外活性测定结果与传统动物体内活性测定结果一致。结论:建立并验证了一种利用KGN细胞体外测定FSH生物学活性的方法,有望代替传统的动物体内活性测定方法,可用于FSH的生物学活性评价和质量控制。     

体外皮肤刺激模型的生物标志研究进展

皮肤刺激试验是人类健康相关产品危险性评价的常见项目,传统皮肤刺激试验采用实验动物进行,成本高周期长,给动物造成一定程度的痛苦。近年来,多种替代动物试验的体外模型被开发和应用。体外试验主要通过定量检测细胞活性和代谢变化的生物标志物预测体内的效应,应用最广泛的生物标志物是细胞活性、炎性因子、胞质酶等,在生物技术的推动下,新的特异性标志物被开发和验证。     

一种体外皮肤腐蚀性试验替代方法的建立

目的建立皮肤腐蚀性的体外检测方法—大鼠经皮电阻试验(TER),优化OECD指南标准TG 430大鼠经皮电阻方法结果判定标准,并评价该方法作为替代方法用于评估化妆品原料的皮肤腐蚀性检测可行性。方法参照经合组织(OECD)化学品检测指南中TG 430体外皮肤腐蚀性大鼠经皮电阻试验的流程,使用Wistar大鼠对16种参考化学物质进行皮肤腐蚀性检测,设定不同的判定标准方案,通过对比筛选出最优的判定标准方案;并在5个实验室间进行11种参考物质的结果比对。结果改良后的TER结果判定方案结论与参考化学物质的实际腐蚀性结果具一致性(Kappa值0.64),改良方案B的特异性为66.7%,敏感性为100%,效能最高;实验室间比对结论差异无显著性(P0.05),实验室间对11种参考物质的判定一致率为72.7%。结论经改良的大鼠经皮电阻试验可较好的筛选化学物质的腐蚀性,有望在我国的替代毒理学及化学物质安全性评价中发挥重要的作用。     

五倍子对铜绿假单胞菌R质粒消除作用的实验研究

探讨中药五倍子提取液对铜绿假单胞菌R质粒的消除作用。对老年呼吸系统感染患者痰中分离的铜绿假单胞菌R质粒进行了检测 ,并选用中药五倍子提取液对该质粒进行了体外体内消除试验。结果可见 ,体外药物作用 2 4 ,4 8,72hR质粒消除率分别为 0 ,10 .2 % ,3.4 % ,SDS对照组分别为 0 ,0 .8% ,1.6 %。体内药物作用 2 4 ,4 8,72h ,R质粒消除率分别为 0 ,2 % ,13.6 % ,对照组均为 0。可见 ,中药五倍子提取液对铜绿假单胞菌R质粒在体外、体内均具有消除作用 ,体内消除作用强于体外。     

成团泛菌低分子脂多糖的急性毒性、刺激性、致敏性及遗传毒性评估

本研究对成团泛菌低分子脂多糖(Pantoea agglomerans lipopolysaccharide,LPSp)的安全性进行初步评估.本研究采用一次限量法,用昆明种小鼠进行LPSp急性经口毒性试验,了解LPSp的急性毒性;采用新西兰兔分别进行LPSp急性和多次皮肤刺激性试验以及急性眼刺激性试验,了解LPSp的皮肤和粘膜刺激性;采用豚鼠进行LPSp皮肤变态反应试验,了解LPSp的致敏性;应用平板掺入法进行鼠伤寒沙门氏菌/回复突变试验和小鼠骨髓细胞微核试验考察LPSp的遗传危害.急性毒性试验结果显示,LPSp对小鼠经口一次灌胃的LD50大于5 000 mg/kg体重,属实际无毒级别;LPSp急性和多次皮肤刺激性试验以及急性眼刺激性试验结果显示,皮肤刺激和眼刺激积分均为0分,LPSp对皮肤无刺激性、对眼睛无急性刺激性;在皮肤变态反应试验中,LPSp在各观察时间点的皮肤变态反应积分均为0分,其致敏率均为0%,说明LPSp对豚鼠无致敏性; LPSp的鼠伤寒沙门氏菌/回复突变试验结果呈阴性(P>0.05);LPSp的小鼠骨髓细胞微核试验结果亦呈阴性,LPSp 各剂量组的微核发生率与阴性对照组未见统计学差异(P>0.05),而与阳性对照组有明显差异(P<0.01).本研究结果表明,在本实验剂量范围内,LPSp对小鼠经口毒性极低,属实际无毒级别,对家兔皮肤和眼睛无明显刺激性,对豚鼠无致敏性,对所试菌株和小鼠体细胞无诱变性和致突变性.     

MUTZ-3树突细胞对B型流感嗜血杆菌结合疫苗组分的应答

<正>对于疫苗注册和批签发而言,疫苗效力测定应该是指令性进行的,由于体内效力测定受到各种各样因素的限制,因此有必要采用相关的体外替代效力测定。这些替代试验应当最好包括来源于目标(人类)种系的细胞,针对人体体内发生的因免疫接种导致的一系列免疫应答是不可能通过使用单一细胞类型就可测定出来的,即使树突细胞能成为一种     

The use of HET-CAM test in detecting the ocular irritation

Agrochemicals must undergo numerous toxicological tests before registration. One of these experiments is the examination of eye irritation potential. To get knowledge about eye irritation, recently only the in vivo Draize-test is accepted, which is one of the most criticized methods because of the injuries inflicted on the test animals. Several in vitro methods have been used to investigate the toxicity of potential eye irritants with a view to replacing in vivo eye irritation testing. In the HET-CAM test chemicals are placed in direct contact with chorioallantoic membrane of the hen's egg. The occurrence of vascular injury or coagulation in response to a compound is the basis for employing this technique as an indication of the likelihood that a chemical would damage mucous membranes (especially the eye) in vivo. In our studies comparative screening was performed with a set of agrochemicals to establish paralell data on in vitro (HET-CAM) and in vivo (Draize) results in case of 6 agrochemicals. The solutions to be tested are added to the membrane and left in contact for 5 minutes and the membrane is examined for vascular damage at set time periods. Irritancy is scored according to the severity and speed at which damage occurs providing an indication of the likely irritant effect of the compound. Our study showed good correlation between results obtained by the HET-CAM test and those of the Draize rabbit eye test most cases. The present form of the HET-CAM test can be proposed as a pre-screen method of eye irritation tests.     

Irritative effects of some pesticides and a technical component on tissue structure of the chorioallantoic membrane

The chorioallantoic membrane (CAM) is a complete tissue that responds to injury with a complete inflammatory reaction, this process similar to that induced by chemicals in the conjunctival tissue of the rabbit eye. During the study chemicals are placed directly onto the chorioallantoic membrane and the occurrence of vascular injury or coagulation in response to a compound is as an indication of the potential of a chemical to damage mucous membranes. In our study irritant pesticides (Fusilade S, Karathane LC) and a technical pesticide component (Trend) were tested and their effects on the tissue structures of CAM were examined. After treatment with the test materials, first lysis and then haemorrhage were observed macroscopically on CAM. In histological pictures stained with H-E the rupture of the blood vessel wall was seen and blood was observed around the blood vessels in the middle layer. The histological findings correlated well with the macroscopic appearance in this study. In general a good correlation was found between the HET-CAM results and reported data from Draize test. The subjective nature of the evaluation is reduced through the histological examination of treated CAM. The HET-CAM test can be a useful component of a battery of tests needed for replacing the Draize rabbit eye irritation test.     

Assessment of the eye irritating properties of chemicals by applying alternatives to the Draize rabbit eye test: the use of QSARs and in vitro tests for the classification of eye irritation

Huggins has reported on the current situation relating to the development of alternatives to the Draize eye irritation test with rabbits, and an ECVAM Working Group have reviewed the efforts needed in order to replace this animal test within the next 10 years by using the results of non-animal assessment methods. Our report reviews regulatory experience gained over the last 20 years with the EU chemicals notification procedure with respect to the assessment of eye lesions observed in Draize tests. The nature of eye lesions and their importance for classification and labelling of possible hazards to human eyes are evaluated and discussed, with a view to promoting the development of specific in vitro assays which are able to discriminate between eye damage, moderate eye irritation, and minor irritation effects which are completely reversible within a few days. Structural alerts for the prediction of eye irritation/corrosion hazards to be classified and labelled according to international classification criteria, are presented, which should be validated in accordance with internationally agreed (OECD) principles for (Q)SAR system validation. Physicochemical limit values for prediction of the absence of any eye irritation potential relevant for human health can make available a definition of the applicability domains of alternative methods developed for the replacement of the Draize eye irritation test.     

A reassessment of the in vitro RBC haemolysis assay with defibrinated sheep blood for the determination of the ocular irritation potential of cosmetic products: comparison with the in vivo Draize rabbit test

We examined the correlation between results obtained from the in vivo Draize test for ocular irritation and in vitro results obtained from the sheep red blood cell (RBC) haemolytic assay, which assesses haemolysis and protein denaturation in erythrocytes, induced by cosmetic products. We sought to validate the haemolytic assay as a preliminary test for identifying highly-irritative products, and also to evaluate the in vitro test as alternative assay for replacement of the in vivo test. In vitro and in vivo analyses were carried out on 19 cosmetic products, in order to correlate the lesions in the ocular structures with three in vitro parameters: (i) the extent of haemolysis (H50); (ii) the protein denaturation index (DI); and (iii) the H50/DI ratio, which reflects the irritation potential (IP). There was significant correlation between maximum average scores (MAS) and the parameters determined in vitro (r = 0.752-0.764). These results indicate that the RBC assay is a useful and rapid test for use as a screening method to assess the IP of cosmetic products, and for predicting the IP value with a high level of concordance (94.7%). The assay showed high sensitivity and specificity rates of 91.6% and 100%, respectively.     

Using in vitro prediction models instead of the rabbit eye irritation test to classify and label new chemicals: a post hoc data analysis of the international EC/HO validation study

The international validation study on alternative methods to replace the Draize rabbit eye irritation test, funded by the European Commission (EC) and the British Home Office (HO), took place during 1992-1994, and the results were published in 1995. The results of this EC/HO study are analysed by employing discriminant analysis, taking into account the classification of the in vivo data into eye irritation classes A (risk of serious damage to eyes), B (irritating to eyes) and NI (non-irritant). A data set for 59 test items was analysed, together with three subsets: surfactants, water-soluble chemicals, and water-insoluble chemicals. The new statistical methods of feature selection and estimation of the discriminant functions classification error were used. Normal distributed random numbers were added to the mean values of each in vitro endpoint, depending on the observed standard deviations. Thereafter, the reclassification error of the random observations was estimated by applying the fixed function of the mean values. Moreover, the leaving-one-out cross-classification method was applied to this random data set. Subsequently, random data were generated r times (for example, r = 1000) for a feature combination. Eighteen features were investigated in nine in vitro test systems to predict the effects of a chemical in the rabbit eye. 72.5% of the chemicals in the undivided sample were correctly classified when applying the in vitro endpoints lgNRU of the neutral red uptake test and lgBCOPo5 of the bovine opacity and permeability test. The accuracy increased to 80.9% when six in vitro features were used, and the sample was subdivided. The subset of surfactants was correctly classified in more than 90% of cases, which is an excellent performance.     

Development of a sensory neuronal cell model for the estimation of mild eye irritation

In an attempt to improve the in vitro test strategy for the estimation of eye irritation, a neuronal cell model has been developed, with cells expressing vanilloid receptor type 1 (VR1) nociceptors. The currently accepted method for measuring eye irritancy is the ethically and scientifically criticised Draize rabbit eye test, despite the fact that alternative in vitro methods are available which have proved to be reliable and reproducible for predicting severe ocular toxicity. However, no alternative tests for measuring neuronal stimulation have yet been developed, and the prediction of eye irritation in the mild range is therefore insufficient. VR1 is a nociceptor localised in C-fibre neurons innervating the cornea and the surrounding tissue, and it responds to potentially damaging stimuli by releasing Ca2+ into the cytoplasm. As a sensory endpoint, [Ca2+]i was measured in VR1 transfected cells, as well as in control cells. Short-term cell cytotoxicity studies (cell membrane rupture and morphological divergence) were used to determine the non-corrosive concentrations of the test chemicals. Preliminary results indicated that hygiene products used daily may induce eye irritation via VR1 nociceptors. The lowest toxic concentration (0.025%) of liquid hand soap, as determined by morphologic divergences of cells, generated an 80% increase in [Ca2+]i over the basal [Ca2+]i in VR1 transfected cells, whereas the non-specific [Ca2+]i increased by 33%. Furthermore, all the endpoints studied indicated that shampoo for children was less active than shampoo for adults. If this method is successfully validated with standardised reference chemicals, the model could complete the test battery of in vitro alternatives, resulting in the saving of thousands of laboratory animals.     

In vitro cytotoxicity test for estimating non-ocular irritation dose of ophthalmic solutions

The in vitro cytotoxicity test for estimating the non-ocular irritation dose of ophthalmic solutions was investigated. In the in vitro test, normal human epidermal keratinocytes (NHEK) in a confluent monolayer were incubated for 48hr in a medium with test compounds. The concentration of a test compound which causes a 50% reduction in NHEK viability was determined as IC₅₀ by MTT colorimetric assay. For comparison, the in vivo rabbit ocular irritation tests were carried out by the standard Draize method. The maximum concentration, which did not show any ocular irritation, was determined as DS₀. The results showed the correlation coefficient between the IC₅₀ values and the DS₀ values for 19 test compounds to be 0.82. However, the correlation coefficients for 10 compounds, which have IC₅₀ values of less than 300g/ml, and for 7 alcohols were 0.99. The IC₅₀-DS₀ correlation curves obtained could be utilized as the critical concentrations for ocular irritation. These results suggest that our in vitrolin vivo test can estimate non-ocular irritation dose of the ophthalmicpreparations in advance of the in vivo tests.Abbreviations DS₀ Draize Score 0 - KGM keratinocyte growth medium - NHEK normal human epidermal keratinocytes     

Ocular safety: a silent (in vitro) success story

Ocular irritation testing has been one of the animal test methods most criticised by animal welfare advocates. Additional criticism has arisen from within the scientific community, based on the variability of the animal test results and the questionable relevance of the extremely high dose levels employed. As a result, the Draize eye irritation test has been one of the main targets for in vitro replacement. Despite extensive efforts, however, there is still no in vitro method that is fully validated as a regulatory replacement. In spite of this, many individual companies are using diverse in vitro ocular irritation tests to gain important safety and efficacy information about their products and raw materials, eliminating the need for animal testing in the process. This is done in a safe fashion by applying intelligent testing paradigms. ECVAM has played a major role in this success, through its many programmes that have emphasised the importance of understanding the true toxicological need, and then using in vitro tests to provide that information. Thus, even in the absence of a successfully validated regulatory assay, the desired result of reducing animal testing is being met.     

The use of bootstrap resampling to assess the variability of Draize tissue scores

The acute dermal and ocular effects of chemicals are generally assessed by performing the Draize skin and eye tests, respectively. Because the animal data obtained in these tests are also used for the development and validation of alternative methods for skin and eye irritation, it is important to assess the inherent variability of the animal data, since this variability places an upper limit on the predictive performance that can be expected of any alternative model. The statistical method of bootstrap resampling was used to estimate the variability arising from the use of different animals and time-points, and the estimates of variability were used to determine the maximal extent to which Draize test tissue scores can be predicted.     

A compartment model to calculate time-dependent concentration profiles of topically applied chemical compounds in the anterior compartments of the rabbit eye

Hitherto, none of the existing in vitro methods has been convincingly demonstrated to be suitable as a replacement for the Draize rabbit eye irritation test. We examine the hypothesis that one reason for this is that insufficient consideration has been given to the differences in the effective concentrations at which chemicals operate in vitro and in vivo. When a chemical is applied topically to the eye, the strength of the observed irritation that it elicits depends both on its toxic potential toward cells or tissues, and its effective concentration in the tissues of the eye. Most of the existing in vitro methods are based on isolated cells or tissues, and thus may be useful in assessing the cytotoxic potentials of chemicals. However, a reliable approach to assessing the effective concentrations of chemicals within the various tissues of the eye is lacking. A simplified compartment model is presented for calculating the time-dependent, intra-ocular concentration profiles of topically applied chemicals. The model encompasses the outer surface of the eye, three distinct segments of the cornea (subdivided into the epithelium, stroma and endothelium) and the conjunctiva. Transport through the membranes of these compartments is described as passive diffusion. For the transport coefficients, rate equations are established that contain, as free parameters, the molecular size and the partition coefficient of the chemical, as well as some intrinsic membrane parameters, such as thickness, viscosity and pore density. Numerical values for the unknown membrane parameters were estimated by fitting the theoretical rate equations to measured permeability coefficients. The compartment model was applied to an independent set of 52 test chemicals compiled from the European Commission/UK Home Office validation study. The calculated passage times (required to let 95% of the chemical reach the posterior eye tissues) varied between 0.33 minutes and 50.6 minutes, and are generally much shorter than the typical duration of observed impairments in the cornea or conjunctiva. This finding suggests that short-term contacts of the eye tissues with a chemical are sufficient to elicit long-term eye irritation. An example is given, showing how the conventional approach of using in vitro endpoints as predictors of eye irritation can be improved significantly by incorporating into the prediction the calculated intra-ocular concentration of a chemical.