Therapeutic potential of peptides with neutralizing ability towards the venom and toxin (CaTx-I) of crotalus adamanteus

The CaTx-I (PLA2) toxin of Crotalus adamanteus venom is responsible for most of the symptoms observed during envenomation. Synthetic peptides were designed and screened for venom (0.8 μg/ml) and CaTx-I (0.1 μM) inhibition at varying doses of the peptide (10000- 0.0001 μM) using a Cayman chemical human secretory phospholipase A2 (sPLA2, Type II) assay kit. Further, in vitro neutralization studies were evaluated by a fixed dose of peptide (1 μM) against venom (0.8 μg/ml) and toxin (0.1 μM). Among the linear peptides (PIP-18, cyclic C and PIP59-67) that showed potent neutralizing effects against the venom/toxin of C. adamanteus. PIP-18 [IC50, 1.23 μM] and cyclic C [IC50, 1.27 μM] peptides possessed the strongest inhibitory effect against CaTx-I. A fixed dose of CaTx-I (75 μg/kg) was administered intraperitoneally (i.p.) into mice followed by an i.p. injection of peptides PIP-18 and cyclic C at (6 μg/mouse), venom (150 μg/kg) and toxin CaTx-I alone served as references. Mice treated with PIP-18 and cyclic C showed a very strong neutralizing effect and markedly reduced mortality compared to the control after 24 h. The CA venom and CaTx-I injected mice showed severe toxicity after 24 h. Peptides PIP-18 and cyclic C were non-hemolytic at 100 μM. They produced a significant decrease in lipid peroxidase (LPx) and enhancement of superoxide dismutase (SOD), catalase (CAT) and Glutathione-s-transferase (GST) levels indicating their antioxidant property against venom-induced changes in mice. This study confirmed the potent snake venom neutralizing properties of peptides.     

细菌内毒素与抗内毒素治疗

综述了有关细菌内毒素的分子结构及其特征、识别机制、生物学效应及抗内毒素治疗的研究进展     

Endotoxin contamination of engineered nanomaterials

Abstract

Endotoxin has established health impacts and may be a potential confounding factor in toxicity studies of engineered nanomaterials (ENM). We aimed to characterize endotoxin contamination for a representative set of carbon-based ENM. The established method for quantifying endotoxin relies on its activity in a complex biochemical assay system. Because of their physical and chemical properties, measurement of endotoxin associated with many ENM presents non-trivial technical challenges. We have made progress in identifying and implementing methods for ENM analysis with respect to endotoxin content, revealing varying levels of endotoxin contamination in the ENM examined here. The physical association of ENM and endotoxin and their shared physiological effects suggest the possibility that contaminating endotoxin may contribute to the toxicity that is ascribed to ENM. We found in this small number of samples that endotoxin levels were not related to type of ENM or surface area but may be introduced randomly during manufacture.     

牛磺酸注射液细菌内毒素检查法

目的:探讨牛磺酸注射液的细菌内毒素检查法.方法:按照2000年版<中国药典(二部)>收载的细菌内毒素检查法及其应用指导原则的要求进行试验.结果:对于牛磺酸注射液(原液),可用标示灵敏度为0.5 EU/mL的鲎试剂进行细菌内毒素检查.结论:鲎试剂可用于牛磺酸注射液的细菌内毒素检查.     

牛血清的细菌内毒素检测

目的 考察牛血清细菌内毒素检查法的可行性。方法 采用不同厂家生产的不同批号、不同灵敏度的鲎试剂进行干扰试验，按2005年版《中华人民共和国药典（三部）》附录收载的细菌内毒素凝胶限量检查法进行试验。结果 选用灵敏度为0．125EU／mL的鲎试剂时，牛血清稀释80倍后不会对细菌内毒素检查产生干扰。结论 用鲎试剂检查牛血清细菌内毒素的方法是可行的。     

替硝唑注射液的细菌内毒素检测

目的: 建立替硝唑注射液细菌内毒素检测方法.方法: 应用不同厂家鲎试剂对替硝唑注射液进行干扰实验.结果: 替硝唑注射液2倍稀释液对细菌内毒素不产生干扰.结论: 细菌内毒素检测方法可取代替硝唑注射液热原的检查.     

红花注射液细菌内毒素的检测

目的:建立快速的红花注射液细菌内毒素检查法来替代热原检查法。方法:用不同厂家的鲎试剂对不同批号的红花注射液分别进行干扰试验,考察确立红花注射液内毒素检查法。结果:将红花注射液稀释40倍可消除干扰作用,结果准确可靠。结论:利用细菌内毒素检查法代替红花注射液热原检查是可行的。     

氟康唑注射液细菌内毒素检查法

目的：确立氟康唑注射液细菌内毒素检查方法。方法：参照中国药典2000年版二部细菌内毒素检查法要求进行试验。结果：该药在稀释4倍后不干扰内毒素试验。结论：该药采用内毒素检查法代替热原检查法，方法可行。     

氯法拉宾注射液细菌内毒素检查法的建立

目的建立氯法拉宾注射液细菌内毒素检查方法。方法根据中国药典2005年版二部附录收载的细菌内毒素检查方法进行实验。结果氯法拉宾注射液稀释4倍以后,对细菌内毒素检查无干扰;3批样品细菌内毒素检查均符合规定。结论细菌内毒素检查方法可用于该产品的质量控制。     

丁酸氯维地平的细菌内毒素检查法

目的 建立丁酸氯维地平的细菌内毒素检查方法。方法 以60%乙醇溶液溶解丁酸氯维地平,再用细菌内毒素检查用水稀释后按中国药典2010年版二部附录细菌内毒素检查法,采用2个不同厂家的鲎试剂进行干扰试验。结果 根据临床实际应用情况,确定丁酸氯维地平的内毒素限值L=4.7 EU·mg^-1;在本实验条件下,丁酸氯维地平的最大不干扰浓度为0.013 3 mg·mL^-1,可用灵敏度0.06 EU·mL^-1及以上的鲎试剂检测丁酸氯维地平中的细菌内毒素。结论 本试验建立的细菌内毒素检查方法可用于丁酸氯维地平的细菌内毒素检查,控制其产品质量。     

环组己酰胺注射液细菌内毒素检查法的研究

目的:建立环组己酰胺注射液细菌内毒素检查法。方法:参照中国药典2000年版二部附录XI E细菌内毒素检查法和附录XI XF细菌内毒素检查法应用指导原则进行试验。结果:供试品按1:4稀释液检查无干扰作用。结论:细菌内毒素检查法可适用于该制剂。     

蛋白质补充液的细菌内毒素检测

目的 考察蛋白质补充液的细菌内毒素检查方法的可行性.方法 依据《中华人民共和国药典》2010年版附录XIE细菌内毒素检查法和美国FDA的鲎试验应用指南,使用内毒素分散剂消除供试品的干扰作用,检测蛋白质补充液的细菌内毒素含量是否符合规定.结果 蛋白质补充液在使用内毒素分散剂稀释2倍后对细菌内毒素实验无干扰作用,其细菌内毒素限值符合规定.结论 该产品可以采用细菌内毒素检查法.     

果糖二磷酸钠注射液的细菌内毒素检查方法探讨

目的：建立果糖二磷酸钠注射液的细菌内毒素检查法。方法：参考中国药典2005年版二部附录XIE,确定果糖二磷酸钠注射液的细菌内毒素限值及进行干扰试验测定最大非干扰浓度。结果：果糖二磷酸钠注射液对细菌内毒素检查有抑制作用,稀释成4mg/mL的供试品溶液后,用0.125EU/mL的鲎试剂对细菌内毒素检查无干扰。结论：果糖二磷酸钠注射液适用于细菌内毒素检查法。     

血凝酶细菌内毒素检查法建立

目的：建立血凝酶原料药的细菌内毒素检查方法,以控制产品热原.方法：按2010年版《中国药典》（二部）细菌内毒素检查法,用不同厂家鲎试剂对3个批号的血凝酶进行细菌内毒素检查和干扰试验.结果：样品浓度稀释到0.005 KU·ml-1时对细菌内毒素检查法无干扰作用.结论：血凝酶可以通过细菌内毒素检查法控制其细菌内毒素含量.     

Endotoxin and tryptophan-induced hypoglycaemia in rats

Pretreatment of rats with increasing, but non-lethal, doses of endotoxin was associated with a parallel increase in sensitivity to induction of hypoglycaemia by tryptophan. Acutely streptozocin-diabetic animals became hypoglycaemic with endotoxin alone, and this was increased further by tryptophan. Variations in tryptophan sensitivity between rat populations cannot be explained by previous history of exposure to endotoxin. Endotoxin abolished the increase in tryptophan dioxygenase activity caused by triamcinolone, but not that caused by tryptophan. Triamcinolone was effective, however, when given together with tryptophan to endotoxin-treated rats. The activity of tryptophan dioxygenase in vivo and in liver cells in vitro is unchanged by exposure to endotoxin at 1 mg/kg body wt. Turnover studies indicated that hypoglycaemia resulted from inhibition of gluconeogenesis. There was no evidence to support a role for insulin in this process and results were consistent with an endotoxin-mediated hepatic insensitivity to glucagon. They also suggested that quinolinate, rather than 5-hydroxytruptamine, may be the intracellular agent responsible for inhibition of gluconeogenesis.     

葛根素注射液细菌内毒素检查

目的:建立葛根素注射液细菌内毒素检查方法。方法:根据2005年版《中国药典》(二部)附录收载的细菌内毒素检查方法进行试验。结果:葛根素注射液的检测浓度为0.625mg.mL-1时对细菌内毒素检查法无干扰;6批样品细菌内毒素检查均符合规定。结论:细菌内毒素检查方法可取代热原检查法检查葛根素注射液。     

Interferon beta neutralizing antibodies in multiple sclerosis: neutralizing activity and cross-reactivity with three different preparations

The presence and titer of neutralizing antibodies (NABs) was evaluated by an antiviral biological assay in 387 samples of 111 multiple sclerosis (MS) patients treated with one of the three commercial preparations of interferon beta (IFNbeta). Fifty NAB positive samples were found in 19 patients: 11 treated with IFNbeta-1b (Betaferon(R)) and eight with IFNbeta-1a (five with Avonex(R) and three with Rebif(R)). All the 38 NABs+ samples of patients treated with IFNbeta-1b cross-reacted with IFNbeta-1a of both commercial types. The median level of neutralizing units (NUs) of the sera was higher when tested against IFNbeta-1a than against IFNbeta-1b (p=0.000 vs. Avonexr(R) and p=0.003 vs. Rebif(R)). In line with these data, the NABs+ sera of patients treated with IFNbeta-1a cross-reacted with IFNbeta-1b and the level of NUs were lower when tested against IFNbeta-1b than against IFNbeta-1a (p=0.003). The different amount of NUs against IFNbeta types 1a and 1b could be due to the presence of aggregates in the IFNbeta-1b preparation. The different levels of cross-reactivity of NABs could reduce the bioavailability and therapeutic efficacy of IFNbeta in NABs+ patients switching from IFNbeta-1b to IFNbeta-1a.     

鲎试剂用于葛根素注射液细菌内毒素的检测

本文参考<中国药典>2000年版"细菌内毒素检查法"和"细菌内毒素检查法应用指导原则",对葛根素注射液细菌内毒素检查进行了研究.     

Endotoxin limits in formulations for preclinical research

This brief commentary discusses a review of the current status on endotoxin limits, a critical parameter, for formulations to be administered to animals. The endotoxin units set by United States Pharmacopoeia (USP), and the techniques specified by USP for endotoxin testing are described. Endotoxin limits for preclinical research animal models were derived based on the threshold pyrogenic human dose of 5 E.U. per kg. The limits calculated would act as a guideline for endotoxin limits in preclinical species. A quick reference chart for endotoxin limits is included to provide a guideline for endotoxin limits for animal models used in preclinical research. Derivation of endotoxin limits from K/M for doses and animal models not included in the chart could be calculated as described.