Circumsporozoite protein gene diversity among temperate and tropical Plasmodium vivax isolates from Iran

To date, there is no information on the genetic diversity of the circumsporozoite protein (CSP), a leading vaccine candidate, in Plasmodium vivax populations circulating in Iran. The gene for this protein, Pvcsp, was amplified from 374 P. vivax isolates collected in the temperate northern, and in the tropical southern endemic areas. PCR-RFLP analysis of the repeated central region revealed that the parasites collected in the northern area were almost exclusively of the VK210 type. Parasites collected in the south-eastern areas were of both VK210 and VK247 types. We detected VK210 parasite in 70.5% of the samples, VK247 parasites in 17.5% and mixed type infections in 12% of the isolates. Sequence analysis of 137 isolates obtained from both areas identified a total of 25 distinct genotypes. The degree of genetic diversity was generally higher for the tropical (21 genotypes) than the temperate (7 genotypes) P. vivax populations, a difference possibly reflecting the high cross-border exchanges between Afghanistan and Pakistan and southern Iran. Interestingly, all but two VK210 type isolates sequenced harboured a 36-bp post-repeat insert previously only observed in North Korea and China. This large-scale survey of parasite diversity in the Eastern Mediterranean Region provides a set of baseline data suitable for future molecular epidemiological studies of P. vivax.     

广西微小按蚊和中华按蚊对海南株间日疟原虫易感性研究

广西微小按蚊和中华按蚊感染海南株间日疟原虫，发现广西微小按蚊对海南株间日疟原虫易感性较高，卵囊阳性率为８５．２％（２３／２７），腺感染率为７０．６％（１２／１７）；中华按蚊卵囊阳性率为１．９％（２／１０６），腺感染率为０（０／９３）；而对照组海南大劣按蚊卵囊阳性率为３８．０％（３５／９２），腺感染率为５６．５％（３９／６９）。     

肿瘤坏死血清诱生条件及小鼠体内抗疟原虫作用

本文就含肿瘤坏死因子(TNF)的肿瘤坏死血清(TNS)产生的适宜条件及小鼠体内抗疟原虫作用进行研究。结果表明:NZW兔在卡介苗(BCG)注射二周后经细菌内毒素(LPS)攻击1.5小时在其血清中出现最高活性TNF;TNS对感染疟原虫小鼠体内实验显示:实验组与对照组小鼠疟原虫血症有显著性差异,提示TNS有体内抗疟原虫作用。     

恶性疟原虫疫苗研究Ⅱ．一种新的化学拼接法重组多价保护性抗原的基因

将恶性疟原虫保护性抗原环子孢子蛋白（ＣＳＰ）、环状体感染红细胞表面抗原（ＲＥＳＡ）、裂殖子表面抗原１和２（ＭＳＡ１和ＭＳＡ２）４种抗原中具有Ｔ和／或Ｂ细胞表位的６个基因片段，按照我们设计的方案排成一条线性序列，经在计算机上分析比较后，分成长短不一的８个基因片段（Ｆ１～Ｆ８），其中Ｆ１、Ｆ３、Ｆ５和Ｆ７为正链片段，Ｆ２、Ｆ４、Ｆ６和Ｆ８为负链片段。每相邻两个片段间预设１５个互补碱基搭头。在ＤＮＡ合成仪上分别合成这８个片段后，把Ｆ２～Ｆ７６个片段分别磷酰化，按等摩尔浓度混合。经３０℃退火，使８个片段连接起来，然后按基因体外扩增的原理，填补互补碱基以外的缺口，重组成新的多价基因。我们把这种化学拼接法取名为“缺口填补法（Ｆｉｌｌｉｎｇ－ｑａｐＭｅｔｈｏｄ）”，经克隆和测序验证，表明这种方法具有效果好、经济、简便等优点。     

急性期间日疟患者血浆γ-干扰素和白细胞介素-17水平分析

目的：分析急性期间日疟患者血浆中γ-干扰素（IFN-γ）和白细胞介素-17（IL-17）水平。方法：用酶联免疫吸附方法检测19名急性期间日疟患者（间日疟组）和20名健康志愿者（对照组）血浆中IFN-γ IL-17水平。结果：间日疟组患者血浆中IFN-γ和IL-17水平分别为（18．86±6．77）pg／ml和（41．46±21．03）pg／ml,均明显高于对照组的（9．99±8．78）pg／ml和（25.23±11．83）pg／ml（P〈0．01）。结论：间日疟患者血浆中IFN-γ和IL-17的水平均升高。     

Current developments in malaria transmission-blocking vaccines

Malaria is still a leading cause of morbidity and mortality in human populations. Problems, including drug-resistant parasites and insecticide resistant mosquitoes, ensure the continued hold of malaria in the tropics and sub-tropics. Each year around 100 million cases of malaria result in at least 50,000 deaths outside of sub-Saharan Africa; within sub-Saharan Africa itself, malaria causes around one million child deaths per year. New approaches for malaria control are badly needed and much effort has gone to develop malaria vaccines. In addition to giving personal protection, most such vaccines would also tend to reduce the transmission of malaria. One class of vaccine is being developed specifically for this purpose - the malaria transmission-blocking vaccines (TBVs). TBVs are based upon antigens expressed on the surface of the sexual and mosquito mid-gut stages of malaria parasites. These antigens are the targets of antibodies induced by vaccination of the host and ingested with the parasites in a mosquito blood meal. The antibodies act by inhibiting the parasite’s development within the mosquito itself and they thereby prevent the onward transmission of the parasites. TBVs could contribute to the total interruption of malaria transmission in many locations with relatively low transmission rates, mostly outside sub-Saharan Africa. Under almost all transmission rates, however, TBVs would help reduce malaria incidence and malaria-related morbidity and mortality. Promising recombinant TBV candidate antigens for the two main human malaria parasite species, Plasmodium falciparum and Plasmodium vivax, have been produced and tested in the laboratory; one has undergone early clinical trials.     

色氨酸对疟原虫配子体激活因子的影响

目的 探讨色氨酸代谢产物对斯氏按蚊唾液腺抽提物中疟原虫配子体激活因子的影响。方法 应用柏氏疟原虫体外雄配子体出丝分析方法检测果糖喂饲液中掺入色氨酸后斯氏按蚊唾液腺抽提物疟原虫配子体激活因子的活性变化。结果 斯氏按蚊唾液腺中柏氏疟原虫配子体激活因子与按蚊生长发育程度呈同步变化；喂饲液中掺入色氨酸可增强按蚊唾液腺的出丝诱导活性。结论 喂饲液中掺入色氨酸可提高斯氏按蚊唾液腺中疟原虫配子体激活因子的含量。     

Immunosuppression in murine malaria. IV. The secondary response to bovine serum albumin

The anamnestic antibody response of CBA mice to bovine serum albumin was characterized by a rapid production of high-avidity antibody. After 3 weeks both the total amount of antibody and its avidity declined but still remained above those seen in the primary response for at least 6 weeks. The effects of acute Plasmodium berghei and Plasmodium yoelii yoelii infections upon the induction and the expression of this anamnestic response were studied. Mice infected with these malaria parasites responded poorly to primary immunization and the immunological memory generated was quantitatively subnormal. In addition, presence of the infection during a period between approximately the second and third weeks of the primary response prejudiced the development of high-avidity memory. Optimally primed mice, challenged during a subsequent acute infection, responded well initially, but were unable to maintain the secondary response at a normal level in terms of both quantity and avidity of the antibody. However, if challenge was delayed until after recovery from the infection, a normal secondary response ensued. Antibody concentrations in the sera of primed animals declined rapidly during infection. This was at least partly due to increased catabolism.     

Thrombocytopenia and other hematological complications in children with malaria

Fifteen cases with malarial infection were studied for hematological complications. Thrombocytopenia was observed with P. vivax infection. This complication is otherwise regarded as uncommon with P. vivax malaria. Possible mechanism and effects thereof are discussed.     

磷酸咯萘啶治疗恶性疟疾140例临床疗效观察

应用国产磷酸咯萘啶治疗非洲桑给巴尔籍140例恶性反复发作性疟疾,应用4mg/kg 体重深部肌肉注射,6小时后复注一次。若48小时后疟原虫不转阴者再给药一次。观察退热时间及疟原虫转阴时间均显著短于30例应用氯喹治疗的对照组(P<0.001)。且对氯喹耐药虫株同样有效。治疗期间作用药前后ECG,肝功能及尿常规检查说明本品杀虫作用强、副作用少。