A critical commentary and updating of the guinea pig maximization test

The guinea pig maximization test (GPMT) of Magnusson and Kligman was published in 1969. Since then, a vast body of practical experience with the test has been accumulated. New information requires that certain aspects of the procedure be reevaluated, especially with regard to the interpretation of challenge results. In particular, awareness of the phenomenon of hyperirritable skin (the 'angry back' phenomenon) suggests that presently used controls are not always adequate and may overstate allergenicity owing to false-positive reactions. The control group should be exposed to a chemical insult at induction which provokes an inflammatory reaction comparable to the test substance. We present strategies to distinguish irritant from allergic responses. Allergic reactions should persist on rechallenge weeks later, while nonspecific irritant reactions generally fade and are irreproducible in particular animals. Finally, when a chemical is identified as a contact sensitizer of risk is necessary to estimate the relevance of the test result to usage in the real world.     

Treatment of diabetic autonomic neuropathy with an aldose reductase inhibitor

To evaluate the effects of the aldose reductase inhibitor Ponalrestat (Statil) on diabetic autonomic neuropathy, a double-blind placebo controlled trial was carried out on a group of 34 diabetic patients with documented cardiac autonomic neuropathy. After a 4-week, placebo run-in period, patients were randomised for treatment with 600 mg Statil or placebo for another 24 weeks. Moreover, the reliability of the autonomic nerve function tests was investigated by comparing the results at onset and at week 4. Fifteen patients treated with Statil and 12 with placebo completed the study. Neither symptom scores nor cardiovascular reflexes, pupil reflexes and skin vasomotor reflexes improved after Statil therapy, which led us to conclude that Statil is not effective in the treatment of diabetic autonomic neuropathy. Reliability coefficients for cardiovascular reflexes and pupil reflex showed high values, ranging from 60% to 80%. Therefore these methods are recommended in future therapy trials.     

Studies on the optimal conditions for inactivation of Bordetella pertussis organisms with glutaraldehyde for preparation of a safe and potent pertussis vaccine

The optimal conditions for inactivation of Bordetella pertussis organisms with glutaraldehyde for the production of a safe and potent whole cell pertussis vaccine were investigated. Two bacterial harvests from B. pertussis strain 10536 were treated with glutaraldehyde, each with 0.025, 0.05 and 0.1% concentrations of glutaraldehyde for 10, 60 and 120 min. The nine types of glutaraldehyde-inactivated pertussis vaccine (GIPV) and conventional heat-inactivated pertussis vaccine (HIPV) preparations made from two bacterial harvests were comparatively evaluated for the mouse weight gain test (MWGT), potency, and the histamine-sensitization (HS) and leucocytosis-promoting-factor (LPF) tests. The minimum period for killing the B. pertussis organisms with glutaraldehyde was>10 min for 0.025%, 10 min for 0.05% and 5 min for 0.1% concentration. The average loss in opacity varied from 5 to 10% for GIPV preparations and was 14% for HIPV preparations. The GIPV preparations except those inactivated with 0.025% glutaraldehyde for 10 min (GIPV-A) were much less toxic than the HIPV preparations in the MWGT. The GIPV-A preparations did not pass the MWGT. The GIPV preparations were also much less toxic in HS and LPF tests than the HIPV preparation. The potency of GIPV preparations inactivated with 0.05% glutaraldehyde for 10 min (GIPV-D) was similar to that of HIPV preparations. The prolonged treatments with glutaraldehyde reduced the potency. The GIPV-D preparation with good potency and less toxicity was found to be inactivated with glutaraldehyde under optimal conditions. All the preparations were innocuous in the abnormal toxicity test.     

Optimal Selection of Sib Pairs from Random Samples for Linkage Analysis of a QTL Using the EDAC Test

Percentages of extremely concordant and extremely discordant sib pairs are calculated that maximize the power to detect a quantitative trait locus (QTL) under a variety of circumstances using the EDAC test. We assume a large fixed number of randomly sampled sib pairs, such as one would hope to find in the large twin registries, and limited resources to genotype a certain number of selected sib pairs. Our aim is to investigate whether optimal selection can be achieved when prior knowledge concerning the QTL gene action, QTL allele frequency, QTL effect size, and background (residual) sib correlation is limited or absent. To this end we calculate the best selection percentages for a large number of models, which differ in QTL gene action allele frequency, background correlation, and QTL effect size. By averaging these percentages over gene action, over allele frequency, over gene action, and over allele frequencies, we arrive at general recommendations concerning selection percentages. The soundness of these recommendations is subsequently in a number of test cases.     

电位滴定法测定胰激肽释放酶活力测试条件探讨

本文用ＦＩＰ推荐的方法，以具有国际单位的参照品为标样，滴定液为０．０１ｍｏｌ／ＬＮａＯＨ标准溶液，考查了以ＢＡＥＥ为底物的电位滴定法测定胰激肽释放酶活力的实验条件，通过正交试验得出直观和方差分析的结果，依据酶活力单位高、ＳＤ和ＲＳＤ％较小的原则，求出酶活力测定的最适条件是：酶反应温度为２５℃；缓冲液为０．００１５ｍｏｌ／ＬＮａ２Ｂ４Ｏ７－０．２５ｍｏｌ／ＬＮａＣＬ－２×１０（－４）ｍｏｌ／ＬＥＤＴＡ，ｐＨ为８．００；反应液中酶浓度为０．４８ＩＵ／ｍｌ；底物浓度为５×１０（－３）ｍｏｌ／Ｌ；胰蛋白酶抑制剂浓度为１２５μｇ／ｍｌ。胰激肽释放酶活力测定的实验数据的相对标准偏差小于５％。     

胎盘组织液氨基酸的含量测定及层析鉴别

本文采用层析法进行鉴定,用氨基酸分析仪测氨基酸的含量,为胎盘组织液的质量标准提供可靠依据。本法准确率为99%。     

135例海洛因依赖者乙型肝炎病毒标志检测结果分析

１３５例海洛因依赖者乙型肝炎病毒标志检测结果分析张立学，郑纳新，赖倩（解放军３０７医院．北京．１０００３９）摘要＊＊本文对１３５例海洛因依赖者做乙型肝炎病毒（ＨＢＶ）标志物栓测，结果显示：ＨＢＶ感染阳性率为６５．９％，ＨＢｓＡｇ阳性携带率为７．４％．...     

药物敏感试验指导肺癌合并恶性胸腔积液的顺铂联合其他药物胸腔内化疗

目的用药物敏感试验预测肺癌合并恶性胸腔积液癌细胞对顺铂联合其他药物的敏感度，观察其在指导此类患者的顺铂联合其他化疗药物胸腔内化疗的价值。方法将44例胸腔积液癌细胞阳性肺癌患者随机分为两组：药物敏感试验组（20例，有2例因体外药物敏感试验失败而被排除）和对照组（22例）。药物敏感试验组患者用三磷酸腺苷-肿瘤细胞药物敏感试验（ATP-TCA）法分别检测胸腔积液癌细胞对顺铂加香菇多糖、顺铂加甘露聚糖肽、顺铂加A群链球菌制剂、顺铂加干扰素、顺铂加金黄色葡萄球菌滤液制剂、顺铂加卡介苗多糖核酸、顺铂加红色诺卡菌细胞壁骨架、顺铂加白细胞介素-2的敏感度，并选择抑瘤率最高的联合化疗药物对患者进行胸腔内化疗，观察治疗后胸腔积液完全缓解率及胸腔积液癌细胞转阴率，并与对照组比较。结果药物敏感试验组患者对各联合化疗药物敏感的例数为：顺铂加香菇多糖14例、顺铂加甘露聚糖肽18例、顺铂加A群链球菌制剂17例、顺铂加干扰素10例、顺铂加金黄色葡萄球菌滤液制剂16例、顺铂加卡介苗多糖核酸15例、顺铂加红色诺卡菌细胞壁骨架17例、顺铂加白细胞介素-216例。药物敏感试验组完全缓解率为65．0％，对照组为27．3％（P〈0．05）。药物敏感试验组胸腔积液癌细胞转阴率为80．0％，对照组为45．5％（P〈0．05）。结论用药物敏感试验指导肺癌合并恶性胸腔积液的胸腔内个体化化疗可提高完全缓解率和胸腔积液癌细胞转阴率，该方法具有临床实用价值。     

动物喂养辐照食品的安全性评价

本试验是在多种食品的基础上,加大照射剂量(吸收剂量为0.1～8.0 kGy)和提高辐照食品在膳食中比例(千重80％以上)的条件下,进行了150d的大白鼠喂养试验。通过对饲料的营养成分分析及其利用,对动物的生长发育、血液学、致突变性及病理学等项指标的检测,结果证明是安全的。本试验结果为今后辐照食品商业化提供了安全的证据。