Vibriocidal antibody responses in North American volunteers exposed to wild-type or vaccine Vibrio cholerae O139: specificity and relevance to immunity.

The emergence of a new agent of cholera, Vibrio cholerae O139, has prompted a reevaluation of the vibriocidal antibody assay. This assay, primarily directed to lipopolysaccharide, is an important correlate of O1 immunity. V. cholerae O139 strains are encapsulated, rendering them relatively resistant to killing by serum. Recent reports suggest that there is strain-to-strain variability in the sensitivity of the vibriocidal assay to fully encapsulated O139 strains. We have assessed a modified vibriocidal assay for fully encapsulated O139 strain AI-1837 and its unencapsulated mutant 2L in sera from 53 volunteers given wild-type AI-1837 or its attenuated derivative CVD 112 and from 48 controls challenged with V. cholerae O1 or strains of the family Enterobacteriaceae. Vibriocidal responses to the AI-1837 and 2L strains were seen in 67 and 89% of volunteers, respectively, following a single exposure to the wild-type strain. However, >50% of all controls had low-level vibriocidal responses to both strains. These nonspecific responses were transient and of the immunoglobulin G isotype. No binding activity against purified O139 lipopolysaccharide (LPS) by immunoblotting was seen in control sera. In contrast, vibriocidal assay and strain 2L LPS responses by immunoblotting were detectable in 91% of tested volunteers following a single exposure to O139. The presence of vibriocidal antibody to AI-1837 or 2L was not associated with protection in rechallenge studies with O139 strain AI-1837. The vibriocidal assay with unencapsulated strain 2L may be used to detect exposure to O139 strain AI-1837 in controlled research trials. However, its lack of specificity does not make it useful for determining exposure to V. cholerae O139 in the field.     

Investigation of the Roles of Toxin-Coregulated Pili and Mannose-Sensitive Hemagglutinin Pili in the Pathogenesis of Vibrio cholerae O139 Infection

In this study, adult volunteers were fed tcpA and mshA deletion mutants of V. cholerae O139 strain CVD 112 to determine the role of toxin-coregulated pili (TCP) and mannose-sensitive hemagglutinin (MSHA) in intestinal colonization. Eight of 10 volunteers who received CVD 112 or CVD 112 ΔmshA shed the vaccine strains in their stools; the geometric mean peak excretion for both groups was 1.4 × 10⁵ CFU/g of stool. In contrast, only one of nine recipients of CVD 112 ΔtcpA shed vibrios in his stool (P < 0.01); during the first 24 h after inoculation, 3 × 10² CFU/g was recovered from this volunteer. All recipients of CVD 112 and 8 (80%) of the recipients of CVD 112 ΔmshA developed at least a fourfold rise in vibriocidal titer after immunization. In contrast, only one (11%) of the nine recipients of CVD 112 ΔtcpA developed a fourfold rise in vibriocidal titer (P < 0.01). We conclude that TCP are an important colonization factor of V. cholerae O139 and probably of El Tor V. cholerae O1. In contrast, MSHA does not appear to promote intestinal colonization in humans.     

咳特灵胶囊中扑尔敏含量及均匀度的考察

测定扑尔敏含量及均匀度，用以考察咳特灵胶囊的质量标准，本文采用锌试剂络合，二氯乙烷萃取及分光光度法，测定咳特灵胶囊中扑尔敏的含量及均匀度。结果表明此方法准确、可靠，可作为控制其内在质量的一项指标。     

HPLC法对抗生素发酵中几种培养基的氨基酸含量测定

为使抗生素发酵取得较好的效果，我们对在抗生素发酵中起重要作用的培养基进行了比较试验，对目前已有的三种培养基：麸质粉、玉米浆和药媒——2000进行分析比较，采用高效液相色谱法对其中氨基酸含量进行检测，结果表明，药媒——2000中氨基酸含量高，优于其他氮源，更适于作培养基。     

后补玉米浆提高青霉素发酵水平

对后补玉米浆提高青霉素发酵水平的工艺进行实验。结果表明，用5m^3自动发酵罐，采用半连续发酵，从60小时到180小时之间每天补入玉米浆0．2m^3，发酵单位平均提高2400μ／ml。体积增加1m^3，提高率为9．1％。     

粉针分装过程中影响粉针剂质量的因素

目的：为了减少抗生素粉针剂在有效期内发生结块、变黄问题。方法：通过对粉针分装工艺进行研究及对比实验,总结粉针分装过程中使粉针结块变黄的几个因素：西林瓶干燥灭菌情况;胶塞的吸湿性及透气性;铝盖及封蜡严密度。结论：为减少粉针剂结块、变黄,西林瓶在红外线隧道中的干燥灭菌段应停留5分钟以上,胶塞与西林瓶密封严密,铝盖不松动,沾蜡均匀、严密。     

无菌原粉生产过程中澄明度的控制

改进原粉包装方式,提高无菌原粉的澄明度。通过对无菌原粉生产过程中影响原粉澄明度的有关因素进行分析判断,从而采取一系列相应的措施,如取消生产过程中使用的硫酸纸和胶布,达到改进澄明度及杜绝异物发生的目的,以提高产品的质量。新包装方式的采用,提高了产品的澄明度,并减少了异物发生隐惠,确保患者的用药安全。     

过氧化氢稳定性研究

目的：研究脂肪醇聚氧乙烯醚(AEO)对过氧化氢稳定性的影响。方法：配制含有不同浓度脂肪醇聚氧乙烯醚AEO的过氧化氢溶液,混合后,采用滴定法对其含量进行检测,并利用电导仪对其进行检测。结果：通过对溶液的含量进行检测,可以看出,适量的AEO能提高过氧化氢溶液稳定性。     

影响阿莫西林胶囊分装的因素

目的：解决阿莫西林胶囊分装过程中的装量差异问题,提高阿莫西林胶囊的质量。方法：通过分析阿莫西林胶囊分装过程中的影响因素,找出主要影响因素,并采取有效措施加以控制。结果：采取有效措施以后,解决了阿莫西林胶囊分装中的装量差异问题。结论：采取有效措施,控制阿莫西林胶囊分装中的主要影响因素,能够保证产品质量。     

过氧乙酸稳定性的研究

目的：研究脂肪醇聚氧乙烯醚(AEO)与聚氧乙烯醚脂肪醇钠(AES)对过氧乙酸稳定性的影响。方法：配制含有不同浓度的脂肪醇聚氧乙烯醚(AEO)与聚氧乙烯醚脂肪醇钠(AES)的过氧乙酸溶液,用电导法检测其在不同温度下的电导,并用滴定法对其含量进行检测。结果：通过实验证明,适量AEO和AES能提高过氧乙酸稳定性。