Titration of Cholera Antitoxin in Human Sera by Microhemagglutination with Formalinized Erythrocytes

Microtiter hemagglutination tests employing formalinized sheep erythrocytes sensitized with either crude or purified cholera toxin were used to assay the cholera antitoxin content of human sera. Comparable results were obtained with either crude or purified toxin-sensitized cells with the exception of two sera that gave unusually high hemagglutination titers with the crude toxin. Sera from 13 convalescent cholera patients showed a high degree of correlation between antitoxin levels as determined in vitro by the hemagglutination test and in vivo by the skin permeability factor neutralization test. Fourfold or greater rises in antitoxin levels between acute and convalescent sera were detected in 9 of 15 patients with bacteriologically proven cholera. No significant increases in titer were observed in 14 cases of noncholera diarrhea. Cholera antitoxin was detected by hemagglutination in only 1 of 33 sera, obtained from eight countries, containing vibriocidal antibodies. Formalinized sheep erythrocytes sensitized with toxin and stored at 4 C in the presence of 1:10,000 thimerosal were stable and sensitive for at least 6 months (the longest time tested).     

Calibration and commutability assessment of the 1st International Standard for Diphtheria Antitoxin Human

The 1st International Standard for Diphtheria Antitoxin Human (coded 10/262) was established by the World Health Organization Expert Committee on Biological Standardization in 2012. This paper describes the production, characterization and calibration of the new standard which is intended for use in the standardization of assays used to measure diphtheria antibody responses in human serum. The new standard was calibrated in terms of the International Standard for Diphtheria Antitoxin Equine in an international collaborative study. A total of 8 participants from 8 different countries performed in vivo and/or in vitro toxin neutralization tests and returned data that was used to assign units to the proposed new standard. The new standard has a diphtheria antitoxin potency of 2 IU/ampoule and is predicted to be stable. A follow up study was performed to assess commutability of the new standard. The follow up study was an existing external quality assessment, modified to include the new standard. Results obtained suggest that the new standard is commutable, showing comparable behaviour to native human serum samples in the majority of the assays compared, and is therefore suitable for use as a reference preparation in assays used to measure the level of anti-diphtheria antibodies in human serum.     

Vero细胞法检测白喉抗毒素的研究

参照Ｍｉｙａｍｕｒａ等报道,建立了微量细胞培养检测白喉抗毒素的方法。以家兔皮肤试验为参照,Ｖｅｒｏ细胞培养法敏感度为９８．１１％,特异度为８４．００％,符合率为９６．２０％,相关系数ｒ＝０．９３,在白喉血清抗毒素测定中值得推广     

Modified Microbiological Assay for Rapid Estimation of Antibiotic Concentrations in Human Sera

Antibiotic concentrations in human sera were estimated in 5 to 6 hr by a modified microbiological assay. By using Staphylococcus aureus and Streptococcus pyogenes as the assay organisms, the seeded assay plates were preincubated for 2 to 6 hr and then were stored at 4 C until used for assay. Paper discs saturated with the specimen were placed on the preincubated assay plates with reference discs saturated with known concentrations of antibiotic. After 5 to 6 hr of incubation, zones of antibacterial activity were measured and compared with a standard curve for estimation of antibiotic concentration. Results from this rapid assay method compared favorably with those from the commonly used 24-hr assay.     

Low Concentrations of Trifluoperazine Affect Striatal Cells in Culture

Abstract: Primary monolayer cultures of the newborn rat corpus striatum were treated with the phenothiazine trifluoperazine after various times in culture. When the drug is added to cells at least 3 weeks old, concentrations of 10⁻⁷ and 10⁻⁸ M appear morphologically identical to controls but show significant changes in synthesis of acetylcholine and γ-aminobutyric acid, particularly the former. The results with these very low concentrations suggest that the drug has a highly specific effect directly on striatal cells, and that it is not acting via calmodulin.     

利用猪血清短期培养人体外周血淋巴细胞的研究

用猪血清代替小牛血清作人体外周血淋巴细胞短期培养,进行染色体分析及淋巴细胞转化的研究。在94例姐妹染色单体差别染色的培养中,培养液分别加入小牛血清与猎血清,细胞有丝分裂指数分别为3.91％和3.78％;21例常规法培养中,分裂指数分别为9.10％和9.21％;5例淋巴细胞转化试验,小牛血清和猪血清培养的转化率分别为69.52％和69.59％;16例阉割后公、母猪血清加入培养基中,细胞分裂指数(SCD法)分别为2.96％和3.14％。以上各项对照试验,均无显著性差异(P>0.05)本研究证实,猪血清可用于人体外周血淋巴细胞短期培养。     

Progress in Tetanus Prophylaxis: The Advent of Human Antitoxin

Injections of tetanus antitoxin of animal origin frequently cause serious disability and sometimes death. Despite world-wide knowledge of these effects, millions of prophylactic injections of equine tetanus antitoxin are given annually, and it is continually proposed that the dosage be increased in order to obtain higher “protective” levels in the serum, a procedure which would increase the incidence and severity of reactions. Furthermore, equine antitoxin frequently fails to prevent tetanus.Tetanus antitoxin of human origin is available which carries no risk of complications and confers a higher degree of immunity more quickly than equine antitoxin. The cost of treating reactions to horse serum, together with the financial loss incurred by work-absence, far outweighs the cost of human antitoxin. In the author''s opinion, the use, in this country, of antitoxin of animal origin is no longer medically acceptable and may well prove legally indefensible.     

Automation of a Hemagglutination-Inhibition Test for Parainfluenza 3 Antibodies in Bovine Sera

An automated hemagglutination-inhibition (HI) test for the "shipping fever" strain (SF-4) of parainfluenza 3 antibody in bovine sera was developed and compared to manual tube and microtiter test procedures. The automated system operating at 60 samples per hr provided the most test results per specified time period, and the manual tube test provided the least. The manual microtiter test and the automated system at 40 samples per hr, falling between the two above procedures, were comparable in the number of sera that could be titrated in 1 day by one technician. There was little difference between automated and manual test reproducibility when measured at the twofold titer one-dilution difference level. However, the automated system titrated a higher number of sera at the same titer on repeat runs than either of the manual test procedures. The automated one-quartile difference reproducibility (each twofold dilution subdivided into 4 units-"quartiles") was equal to the manual test one-dilution difference reproducibility. The standard deviation of the per cent variation from the mean of paired serum titers for 40-sample-per-hr runs ranged from +/-3.49 to +/-5.36%. The manual and automated systems were of comparable sensitivity in their detection of negative sera.