恶性疟原虫带7蛋白家族蛋白Cdna的克隆及表达产物特征分析

目的 分离、克隆恶性疟原虫带7蛋白家族蛋白编码基因pfstom,并对其功能进行初步研究。方法 根据国际恶性疟研究公共数据库释放的已完成序列数据(CoDing Sequence,CDS数据)设计引物,用RT—PCR方法从恶性疟原虫中国海南株(FCCl／HN)中得到其带7蛋白家族蛋白基因cDNA-pfstom。应用多种软件对其结构功能、基因进化特征以及同源性分析。用PET30a系统表达其具有stomatin样蛋白结构域的C端蛋白,免疫新西兰大白兔并纯化抗体。Western杂交检测其在FCCl／HN表达情况。结果 pfstom基因编码区全长1125bP,编码374个氨基酸,C端具有和人红细胞整合膜蛋白带7蛋白家族中stomatin样蛋白类似的结构。进化特征分析显示：在带7蛋白家族中,Pfstom蛋白与stomatin样蛋白亲缘关系较近。Western杂交发现Pfstom蛋白在FCCl／HN的滋养体期呈期特异性表达,在与膜相关和与膜不相关的感染红细胞蛋白提取物中都存在。结论 Pfstom是带7蛋白家族蛋白,在FCCl／HN红内期的滋养体期呈特异性表达,环状体期不表达,该蛋白是膜相关蛋白。     

用双夹心斑点免疫金银染色法检测病人血中疟疾循环抗原

应用抗间日疟原虫和抗恶性疟原虫红内期抗原单克隆抗体建立了双夹心斑点免疫金银染色法和双夹心免疫酶斑点法并用于检测间日疟和恶性疟患者血清中循环抗原。共检测20份间日疟血清和15份恶性疟血清,双夹心斑点免疫金银染色法阳性率分别为90％和93％,可检出最低原虫密度为0.0009％;双夹心免疫酶斑点法阳性率分别为85％和87％,可检出最低原虫密度为0。0075％。与包虫病。弓形虫病和乙肝表面抗原阳性血清无交叉反应,检测60份健康献血员血清,两法分别有5％和8％假阳性。初步结果提示双夹心斑点免疫金银染色法检测疟疾循环抗原敏感度较高,若经过适当改进,有可能用于疟疾现场诊断和流行病学调查。     

阿奇霉素治疗间日型猴疟效果的研究

目的探讨阿奇霉素对疟原虫的杀灭作用及对疟原虫复燃的影响。方法健康和免疫缺陷的恒河猴(体重5 kg)各1只,血传感染食蟹猴疟原虫,待血液中疟原虫密度分别到达2 266.67个/μl和3 796.08个/μl时,每只猴每天口服阿奇霉素500 mg,健康猴和免疫缺陷猴分别连续服药12和19 d。每天采血镜检观察。结果健康猴感染后11 d,免疫缺陷猴感染后17 d血中疟原虫消失。两只猴连续7个月血检疟原虫均为阴性。结论单服阿奇霉素对间日型猴疟原虫具有直接杀灭作用,提示对间日型猴疟有较好的近期和远期疗效。     

New molecular marker for Trypanosoma (Duttonella) vivax identification.

Trypanosoma vivax is a widespread hemoparasite in tropical areas and is pathogenic to ruminant domestic livestock as well as wild ruminants. The accurate identification of parasites in both hosts and vectors is crucial for epidemiological studies and disease control programs. We describe here the development of molecular markers specific for T. vivax identification. These markers were used to identify mouthpart infections in field-collected tsetse flies from Cameroon. The markers target the genomic sequence of a species-specific antigen from the bloodstream stages. No cross amplification with other trypanosome species was observed, which makes the markers a reliable tool to detect T. vivax infections, both in hosts and vectors. The PCR-amplified sequence contains a (CA)_n microsatellite repeat for which 11 different alleles were identified. This microsatellite, which showed high polymorphism, provides a suitable marker for population genetic studies.     

间日疟红内期原虫单克隆抗体Ig类别检定及种、期特异性免疫荧光分析

作者用琼脂双向免疫扩散法检定20株抗间日疟红内期原虫杂交瘤McAbs 的Ig类别及IgG亚类。结果显示:其中8株属IgG_1、9株属IgM。用IFA法对此20株杂交瘤McAbs进行种、期特异性免疫荧光的检测和分析,发现它们对间日疟原虫红内期均呈阳性反应,其中 5株与三日疟、6株与恶性疟原虫红内期有交叉反应,而对同种疟原虫子孢子期却均呈阴性反应。     

Identification of Target Antigens of Asexual Blood Stages of Plasmodium falciparum

Seven monoclonal antibodies (McAbs) specific for Plasmodium falciparum (Pf), humanimmune sera of three individuals, two adults and one child, living in a malaria endemic area inHainan Island of China and immune sera of BALB/c mice immunized with the erythrocytic stages ofPF were used to identify the target antigens of asexual blood stages of Pf. The ~(125)I-labeled surfaceantigens with apparent molecular weights of 125, 115, 83, 74 and 67 KDa were mainly recognizedby McAbs 93A3, 94B5, 92D4 and 93D4, but the ~(125)I-labeled surface antigens of 200 and 19 KDawere recognized by McAb 94Dl alone. In addition, the ~(35)S-methionine- labeled target antigens of183, 125, 83 and 55 KDa were also recognized by McAbs 93A3, 94B5 and 94C3. The McAb21E3 against the culture supernatant antigen of Pf only recognized the antigen of 125 KDa labeledwith ~(15)S-methionine. The human immune sera from the adulst living in a malaria endemic area andmouse immune sera not only immunoprecipitated the target antigens which were recognized by theMcAbs but also immunoprecipitated the polypeptides of 140, 100 and some lower - molecularweight. But these target antigens recognized by McAbs, adult immune sera of and mouse immunesera could not be immunoprecipitated by human immune serum of the child with a primary infec-tion. With the antigen competition assay, the unlabeled antigens of Pf could strongly inhibit the im-mune reaction between the McAbs and the ~(125)I-labeled antigens of Pf. It suggested that the antigensrecognized by McAbs and polyvalent immune sera were specific target antigens.     

复方蒿甲醚和组份之一本芴醇两种剂型治疗恶性疟疾临床对比试验

目的 观察复方蒿甲醚及其组份之一本芴醇两种剂型治疗恶性疟疾的疗效和安全性。方法采用双盲（复方蒿甲醚组和本芴醇片剂组），随机对比的方法。病人入院后实行２８天封闭观察。结果 收治１５０例病人，其中复方蒿甲醚组（Ａ）５１例，本芴醇片剂组（Ｂ）５０例，本芴醇胶丸组（Ｃ）４９例；Ａ、Ｂ、Ｃ三组的平均退热时间分别为１７．１±８．６、３４．０±２３．２、２９．４±２４．９小时；平均原虫转阴时间分别为２９．７ ± ８．９、５１．６±１４ ．１、５４．７±１７．４小时；Ａ、Ｂ、Ｃ三组的治愈率分别为９８．２％、９２．０％、９５．８％。三组病人在观察期间均无明显不良反应发生，各项化验检查未见明显异常。结论 复方蒿甲醚和本芴醇两种剂型对恶性疟疾均有良好的治疗作用，但复方蒿甲醚在杀虫速度和控制患者症状方面明显优于本芴醇单药。     

Malaria epidemiology in a rural area of the Mekong Delta: a prospective community-based study

Over the past 10 years, the Mekong Delta region in Vietnam has experienced fast socio-economic development with subsequent changes in malaria vectors ecology. We conducted a 2-year prospective community-based study in a coastal rural area in the southern Mekong Delta to re-assess the malaria epidemiological situation and the dynamics of transmission. The incidence rate of clinical malaria, established on 558 individuals followed for 23 months by active case detection and biannual cross-sectional surveys, was 2.6/100 person-years. Over the 2-year study period, the parasite rate and malaria seroprevalence (Plasmodium falciparum and P. vivax) decreased significantly from 2.4% to almost 0%. Passive case detection (PCD) of clinical cases and serological follow-up of newborns carried out in a larger population confirmed the low and decreasing trend of malaria transmission. The majority of fever cases were seen in the private sector and most were unnecessarily treated with antimalarials. Training and involvement of the private sector in detection of malaria cases would greatly improve the quality of health care and health information system.     

Evaluation of Plasmodium vivax ELISA for the blood screen

Plasmodium vivax malaria is the indigenous strain in the Republic of Korea (ROK). Plasmodium vivax can be transmitted through the transfusions of various blood components, which became a severe problem with the safety of blood transfusions and blood‐related products in ROK. We evaluated a P. vivax‐specific enzyme‐linked immunosorbent assay (Genedia Malaria Ab ELISA 2.0, Green Cross, ROK) with blood samples from four groups: 251 samples from P. vivax‐infected patients, 39 samples from post‐treatment patients upon follow‐up, 200 samples from healthy volunteers and 421 samples from domestic travellers to and from high endemic areas of ROK. The positive cases from the ELISA test were confirmed by both Giemsa microscopic and polymerase chain reaction methods. The clinical sensitivity and specificity of detecting P. vivax with ELISA test were 94.4% and 99.0%, respectively. Thirteen of 421 domestic travellers (3.0%) to endemic areas tested positive. The results indicate the effectiveness of detecting antibodies against P. vivax in blood with Genedia Malaria Ab ELISA 2.0 test in a large blood screen setting.