影响家兔热原检查结果的因素分析

目的统计实验数据,分析影响家兔热原检查结果的因素。方法将一定剂量的供试品静脉注入家兔体内,在规定时间内,观察家兔体温升高的情况。结果基础体温≥38.9℃的家兔,其升温≥0.4℃及≥0.6℃的百分比与基础体温<38.9℃家兔相比具有显著性差异(P<0.05),且不同季节家兔升温≥0.4℃的家兔数百分比具有显著性差异(P<0.05),夏秋两季所占百分数高于冬春两季,夏季(6～8月)家兔基础体温较高。结论不同基础体温家兔对热原敏感程度不同,敏感性随家兔基础体温的升高而下降,为保证热原试验结果的准确性,夏季应适当提前热原质检查时间。     

基因治疗相关产品对热原检测提出的挑战

本文就基因治疗相关产品这一类新制品的热原检测问题进行了分析讨论。将现有的国家法规规定的家兔热原检查法和内毒素检查法对该类产品的检测中存在的缺陷进行了分析,提出了热原检测对该类制品检测时面对的三个挑战;并将国外正在研究、发展的一种新的体外热原检测方法的优势进行了介绍。     

探讨热原试验中影响试验数据的因素

目的通过几组试验,分析热原试验中存在常见影响试验数据的几个要素,并提出解决建议。方法对供试品、预选周期、基础体温、家兔的休息周期等多个方面进行统计,总结影响热原数据变化因素。结果家兔升温总和均值随着连续注射批次的增加而有所降低,体温灵敏度变差;合格家兔在4周以内再次预选,合格比例85%以上,6周符合要求的比例为79.1%,9周合格比例降至66.6%;基础体温38.0~38.4℃及39.3~39.6℃区间家兔实验中体温波动幅度≥0.6℃的动物例数较多,38.0~38.4℃区间家兔降温0℃动物数达到50.0%,39.3~39.6℃区间家兔最大升温≥0.4℃的动物数比例较高;家兔冬季基础体温略低于夏季(约0.2℃),休息72~96 h后对家兔基础体温均值、异常体温动物的数量有较好的控制。结论热原检查应尽量采用不同品种供试品交替试验,并通过控制预选兔的使用周期及合理安排家兔实验休息周期,选择基础体温适中的家兔进行试验,以保证热原试验数据的准确性。     

浙江省热原检查用兔敏感性状况调查

目的调查浙江省热原检查用兔对细菌内毒素的敏感性情况,为提高热原检查结果的准确性和可靠性提供参考。方法对全省所有取得生产许可证单位的家兔,用国家颁发的细菌内毒素标准品,＂热原检查法＂进行检查,剂量分别为5EU/Kg和10EU/Kg,记录并比较各单位家兔的平均升温值和升温率。结果对细菌内毒素,各兔场家兔的敏感性有一定的差异。静脉注射5EU/kg,平均升温值为0.40℃～0.87℃,升温率为35%～83%;静脉注射10EU/kg,平均升温值为0.74℃～1.16℃,升温率为70%～94%。结论不同生产单位的家兔对细菌内毒素的敏感性不同,有必要对热原检查用家兔进行细菌内毒素敏感性检查。     

不同影响因素对热原实验中兔筛选的影响

目的分析不同影响因素对新西兰兔的初次筛选合格率、二次筛选合格率的影响。方法根据2005版《中国药典》进行测定。结果初次筛选结果中,不同季节、体重值、性别、湿度新西兰兔的筛选率都有显著性差异,筛选时间在7～9月、体重值为1.7～2.0 kg、雄性的新西兰兔、在湿度为61～70%的条件下初次筛选率较高;在二次筛选结果中,不同季节、室温、湿度条件下新西兰兔的筛选率都有显著性差异,筛选时间在1～3月、在室温为22.1～23.0℃、湿度为61～70%的条件下新西兰兔的二次筛选率较高。结论在不同影响因素的条件下,新西兰兔的初次筛选合格率、二次筛选合格率均受到影响。     

实验兔脚皮炎与相对湿度的相关性及对热原筛选实验的影响分析

目的分析实验兔脚皮炎发病率与相对湿度的相关性及脚皮炎实验兔对热原筛选实验合格率的影响。方法将2006、2007年实验室相对湿度记录、实验兔脚皮炎记录及热原筛选实验记录进行汇总统计,并对数据进行生物学分析。结果实验室相对湿度超过70％时,可导致实验兔脚皮炎发病率的升高,二者存在显著相关性（P〈0．01）;有脚皮炎的实验兔可降低筛选实验的合格率,二者存在显著相关性（P〈0．01）;实验兔基础体温的高低,对筛选合格率有显著影响（P〈0．0001）。结论实验兔的脚皮炎发病率与环境相对湿度有显著的正相关性,当实验室相对湿度超过实验兔适宜湿度范围时,可导致其脚皮炎的发病率上升;有脚皮炎的实验兔与无脚皮炎的实验免相比,可显著降低热原筛选实验的合格率。     

重复-Gx加速度暴露对家兔心脏结构的影响*

目的: 重复-Gx加速度暴露对新西兰家兔心脏结构的影响。方法: 20只新西兰家兔随机分为2组(n=10):对照组、-Gx加速度暴露组。-3.6 Gx暴露2 s,间隔5 min,每天重复20次,共30 d;对照组不受加速度作用。末次-Gx加速度暴露后,用静脉注射空气法处死动物,迅速取左心室心肌组织,常规取样并采用光学显微镜及透射电镜进行组织学观察。结果: -Gx加速度暴露组家兔心肌切片在光学显微镜下可见心肌细胞的形态及排列等与对照组无显著区别;-Gx加速度暴露组家兔心肌在透射电镜下可见,心肌纤维断裂、排列紊乱、心肌细胞水肿、核膜扩张、血管内皮基膜分离。结论: -Gx加速度暴露可造成家兔心肌细胞超微结构损伤,提示应重视长期重复-Gx加速度暴露对舰载战斗机飞行员心脏功能的影响和防护。     

下游层析工艺中热原的去除

各国药审部门对于生物药品中热原物质的含量都有严格要求。较主要的热原是内毒素。由于内毒素性质极不均一 ,给除热原的工作带来不少挑战。通过分析内毒素在不同环境下的化学、物理性质 ,对于如何在下游层析工艺中去除热原 ,提出了多种方法和建议。     

错位双链核糖核酸的热原反应

由于错位dsRNA的毒副作用得到降低,因此是一类很有潜力的抗病毒、抗肿瘤物质。研究中利用家兔实验评价了PolyI:C和PolyI:C12U引起的热原反应。在10mgml、1mgml、005mgml剂量水平PolyI:C12U均未产生发热和其他毒副作用,而PolyI:C实验组均有发热现象,甚至有家兔死亡。     

重组细胞因子制品热原质试验中的降温现象

中国生物制品规程规定采用家兔试验法进行热原试验。规程要求当家兔降温≥０６℃或２只及２只以上降温在０４～０６℃时应重试。在４２０批各类细胞因子热原质试验中发现２３批出现降温,重试后合格率为１００％。降温原因分析表明降温现象与热原性物质无关,与制品种类不存在显著相关性。因此,热原试验中出现家兔降温时是否需要重试值得商榷     

抗狂犬病血清热原处理工艺的试验研究

作者对抗狂犬病血清精制工艺中明矾吸附步骤进行了试验研究。结果表明,采用合理的吸附剂浓度、适当的吸附时间,对制品中热原质的去除效果明显。改进工艺应用于大批量生产,取得满意效果。     

Effects of beta-endorphin on body temperature in mice at different ambient temperatures

The effect of intracerebroventricular injection of beta-endorphin (beta-END) on body temperature of mice was studied at ambient temperatures (Ta) of 10 degrees, 20 degrees and 31 degrees C. Doses between 0.1 and 10.0 microgram/mouse were studied. The lower (less than 1 microgram) doses of beta-END produced a hyperthermia at all Ta's studied. The higher doses of beta-END produced hyper- or hypothermia depending on the Ta. The subcutaneous injection of naloxone (1 mg/kg) antagonized the high dose hypothermic effects, but not the hyperthermic effect of beta-END. These data suggest that there may be different receptors and/or sites of action for high and low doses of beta-END.     

Nonshivering thermogenesis capacity versus basal metabolic rate in laboratory mice

I wanted to follow the correlation between level of basal metabolic rate (BMR) and maximum response to injection of noradrenaline (MMR_NA) in two lines of laboratory mice subjected to divergent, artificial selection toward high BMR (HBMR) and low BMR (LBMR). HBMR animals had heavier visceral organs (heart, liver, kidney, intestine), but their regulatory NST (MMR_NA–BMR) was lower and interscapular brown adipose tissue (IBAT) lighter than in LBMR mice. Obligatory part of nonshivering thermogenesis (NST) (in other words BMR) depended on visceral organ mass, whereas regulatory NST correlates with mass of IBAT. BMR was not correlated with total NST capacity, but phenotypic correlation between obligatory and regulatory NST was negative. This suggests possibility of substitution of obligatory NST to thermoregulation in a place of the regulatory NST. Then total thermoregulatory energy expenditures do not change.     

Applicability of bacterial endotoxins test to various blood products by the use of endotoxin-specific lysates

Endotoxin contamination is a serious threat to the safety of parenteral drugs, and the rabbit pyrogen test has played a crucial role in controlling this contamination. Although the highly sensitive endotoxin test has replaced the pyrogen test for various pharmaceuticals, the pyrogen test is still implemented as the control test for most blood products in Japan. We examined the applicability of the endotoxin test to blood products for reliable detection and quantification of endotoxin. Nineteen types of blood products were tested for interfering factors based on spike/recovery of endotoxin by using 2 types of endotoxin-specific lysate reagents for photometric techniques. Interfering effects on the endotoxin test by the products could be eliminated by diluting from 1/2 to 1/16, with the exception of antithrombin III. However, conventional lysate reagents that also react with non-pyrogenic substances, such as (1–3)-β-d-glucan, produced results that were not relevant to endotoxin content or pyrogenicity. Our results showed that the endotoxin test would be applicable to most blood products if used with appropriate endotoxin-specific lysate reagents.     

Effect of ivermectin on the cellular and humoral immune responses of rabbits

The objective of this paper is to determine the effect of ivermectin administration on cell mediated (CMI) and humoral immunity (HI) of rabbits. CMI against dinitrochlorobenzene (DNCB) and sheep red blood cells (SRBC) in rabbits was determined by delayed-type hypersensitivity and macrophage engulfment assay (MEA), respectively; whereas, HI to Pasteurella multocida B2 vaccine and SRBC was determined by indirect haemagglutination assay (IHA) and Jerne hemolytic plaque formation assay (JHPFA), respectively. The rabbits were divided into four major groups (A through D) each subdivided into four sub-groups (1 through 4). Rabbits of group A served as vehicle control while those of groups B, C and D were treated with ivermectin at the dose rates of 200 microg/kg, 400 microg/kg and 600 microg/kg b.w., respectively. Cellular immunity was determined in sub-groups 1 and 2 through DNCB and MEA, respectively while HI was determined in sub-groups 3 and 4 through IHA and JHPFA, respectively. The skin sensitivity to DNCB at 24 and 48 h and macrophage engulfment of SRBC were highest (P>0.05) in rabbits administered with 600 microg/kg b.w. The highest geometric mean titers (14.00+/-0.31) and number of plaque forming units (1860+/-0.75) were found in rabbits that received ivermectin at a dose of 600 microg/kg b.w. followed, in order by the groups that received 400 microg/kg, 200 microg/kg b.w. and controls. Leukocyte counts were significantly higher in ivermectin-treated groups (C and D) than group A (vehicle control) and B (ivermectin at the rate of 200 microg/kg). A graded dose immune response suggested an immunopotentiating effect of ivermectin at higher doses.