恶性疟原虫乳酸脱氢酶单克隆抗体的制备及其特性鉴定

为制备抗恶性疟原虫乳酸脱氢酶（LDHp）单克隆抗体（McAb）,并对其特异性进行鉴定,用纯化的LDHp重组抗原免疫BALB/c小鼠,采用杂交瘤技术制备McAb,筛选出分泌高滴度McAb的杂交瘤细胞株,测定其免疫球蛋白亚类及其效价,ELISA、Westen blotting试验分析其特导性。结果,制备出2A5和 1H10两株能稳定分泌抗LDHp　McAb的杂交瘤细胞株,两株单抗均为IgG2b,2A5和1H10培养上清的ELISA效价分别为1:512和1:256,腹水效价分别为1:25600和1:12800,两株单抗与间日疟、红细胞、弓形虫、日本血吸虫等抗原均不发生交叉反应,能识别恶性疟原虫的33Kda虫源蛋白。证明制备的抗LDHp杂交瘤细胞株能分泌高滴度和高特异性的单抗。     

胶体金层析法检测恶性疟原虫HRPII抗原的应用研究

目的 :建立一种简易快速 ,适于基层或流行病学调查的自测式胶体金免疫层析法 (GICA)用于检测恶性疟原虫中 H RPII抗原 ,判定是否现症感染。方法 :用 GICA测试条检测全血及滤纸血样中的 H RPII抗原。结果 :40例恶性疟全血及滤纸血 H RPII抗原阳性检出率均为 1 0 0 ,与镜检结果相符合 ;2 5例间日疟均为阴性。结论 :GICA检测血中恶性疟原虫 H RPII抗原特异性强、灵敏度高、简便快速 ,无需特殊仪器设备 ,滤纸血的应用使样本的采集、保存和运输更为便利 ,适合大规模流行病学调查和基层使用 ,有广泛应用价值。     

恶性疟原虫多表位重组疫苗在大肠杆菌中的表达及纯化

目的 在体外表达和纯化目的的蛋白,为下一步抗攻击试验提供安全有效的产品。方法 将化学合成的恶生疟原虫保护性抗原复合基因（ＨＧＦＳＰ）与表达载体ｐＲＳＥＴ重组,在大肠杆菌ＧＩ２１进行表达;工程菌经超声破菌、离心、离子交换层析、疏水层析、分子支析等步骤纯化。结果 ＳＤＳ－ＰＡＧＥ显示表达产物以非融合、可溶性的形式表达,相对分子质量为２３ｋＤａ,占总菌体蛋白的２３．６５％,纯度可达９５％以上。Ｗｅｓｔｅ     

Human phase I vaccine trials of 3 recombinant asexual stage malaria antigens with Montanide ISA720 adjuvant

Two phase I vaccine trials were conducted to test the immunogenicity and safety of a vaccine containing three recombinant malaria antigens from the asexual stage of Plasmodium falciparum. The three antigens are a fragment of MSP1 (190LCS.T3); MSP2 and a portion of RESA and were formulated in Montanide ISA720 adjuvant. These trials investigated the dose response of each antigen for eliciting both antibody and T-cell responses and the immunogenicity of a mixture of the antigens compared with the antigens injected separately. All three antigens elicited both antibody and T-cell responses. Strong T-cell responses were observed with 190LCS.T3 and RESA with stimulation indices exceeding 100 for peripheral blood leucocytes in some individuals. The antibody responses were generally weak. The human antibody responses observed with MSP2 in Montanide ISA720 were not significantly different from those obtained in an earlier trial which used MSP2 with alum as the adjuvant. No antigenic competition was observed: volunteers receiving a mixture of antigens had similar responses to those receiving the three antigens at separate sites. Tenderness and pain at the injection site were common over the first few days following immunization. In some volunteers, especially those receiving the highest doses tested, there was a delayed reaction at the injection site with pain and swelling occurring approximately 10 days after injection.     

Clinical efficacy and pharmacokinetics of artemisinin monotherapy and in combination with mefloquine in patients with falciparum malaria

1The aim of this study was to assess the pharmacokinetics, clinical efficacy and safety of artemisinin alone and in combination with mefloquine. 2Thirty-eight adults with symptomatic Plasmodium falciparum malaria were randomly assigned to receive either artemisinin (500 mg single dose followed by another 500 mg on day 1 and then 250 mg twice daily for 4 days) or artemisinin (500 mg single dose followed by 750 mg on day 1 and then 250 mg three times daily for one more day) in co-administration with mefloquine (250 mg three times daily for the first day). All drug administration was by the oral route. Patients were hospitalized at the Kibaha Designated District Hospital, Kibaha, Tanzania, for 6 days and a follow up for 3 weeks was performed. 3Treatment with the artemisinin/mefloquine combination resulted in a shorter parasite clearance time (PCT) of 24 (22, 27; 95% confidence interval) h vs 31 (27, 36) h and fever subsidence time (FST) of 14 (12, 16) h vs 20 (18, 23) h compared with artemisinin monotherapy. The 95% CI for the difference of the PCT and FST were 1.7, 12 and 3, 10, respectively. Parasites were detected in 7 out of 17 patients (41%) receiving artemisinin monotherapy at the 3rd and 4th week follow up visits. No parasites were detected after the combination therapy. 4The maximum plasma concentrations ( C_max) were similar after artemisinin monotherapy (615.4±387.0 ng ml⁻¹) and in combination with mefloquine (851.8±523.6 ng ml⁻¹). Elimination half-lives (t_1/2) were also identical at 2.2±0.6 h and 2.5±0.7 h, respectively. However, the AUC values were higher ( P<0.05) after combination therapy (3252±1873 ng  ml⁻¹ h) than after monotherapy (2234±1502 ng ml⁻¹ h). The oral clearance values were lower ( P<0.05) after combination therapy (195.4±86.9 l h⁻¹) than after monotherapy (314.3±189.4 l h⁻¹). PCT and FST normalized to initial parasitaemia correlated with AUC(0,  t) (r_s=0.56, P=0.02, r_s=0.58, P=0.01, respectively) and with C_max (r_s=0.62, P=0.01, r_s=0.68, P=0.005, respectively) in the artemisinin monotherapy only. 5One patient on the combination therapy developed a psychiatric condition and two patients on the monotherapy developed skin itch.     

Plasmodium vivax CS peptides display conformational preferences for folded forms in solution

Abstract: Spectroscopic techniques have been used to study the conformations of several synthetic peptides with sequences corresponding to the repeat regions of the circumsporozoite proteins of Plasmodium vivax, variants vk‐210 and vk‐247. As has previously been shown for P. falciparum, turn‐like folded conformations are observed, in rapid dynamic equilibrium with extended‐chain forms. These results are consistent with the known similarity of the structural, biosynthetic and immunological properties of the circumsporozoite proteins of different plasmodial species. Additionally, the observation of folded conformers provides a rationale for the effectiveness of these peptides as immunogens and potential vaccines.     

Impact of the malaria parasite on reproductive indices of male mice

Aim:  To investigate the impact and possible mechanism of action of the rodent malarial parasite on reproduction.
Methods:  Male albino mice were infected with 15, 30 and 45% Plasmodium berghei berghei through inoculation with 10⁷ parasitized red blood cells. Each experiment had its own control that was not infected with P. berghei berghei . Mice infected with 15% P. berghei berghei were killed on days 0, 5, 10 and 15; those infected with 30% P. berghei berghei were killed on days 0, 3, 6 and 10; and those infected with 45% P. berghei berghei were killed on days 1–7 after infection. Caudal epididymal sperm motility, counts and morphology, body and wet organ weights and hematological indices were determined.
Results:  The results showed a progressive duration dependent decrease in sperm motility, sperm count and viability ( P  < 0.01) in parasitized mice. There were significant decreases in serum testosterone and increases in cortisol levels ( P  < 0.05) in the infected mice compared with the controls. There was also a progressive decrease ( P  < 0.05) in red blood cell count and packed cell volume. However, there was a progressive increase ( P  < 0.01) in white blood cell count and weight of the spleen and liver. There was no significant change in weight of the testis and epididymides.
Conclusion:  The results suggest that the malaria parasite could depress male fertility indices. (Reprod Med Biol 2006; 5 : 201–209)     

Evaluation of the ICT Malaria Pf test for rapid post-mortem diagnosis of Plasmodium falciparum malaria in corpses examined for forensic reasons

To test the diagnostic value of a rapid and simple immunochromatographic test (ICT) based on the detection of Plasmodium falciparum histidine-rich protein 2 (PfHRP2) for post-mortem examination, blood samples from 30 consecutive corpses were analysed by ICT and Giemsa-stained blood films. Compared to microscopy, ICT had 100% sensitivity and 100% specificity even after a considerable time had passed between the presumed time of death and testing or after prolonged storage of whole blood samples. The ICT yielded positive results for four travellers who had returned from Kenya and died from Pl. falciparum malaria. The ICT might therefore serve as an additional tool for rapid malaria diagnosis, especially in non-endemic countries where experience with microscopic malaria detection is limited. Received: 5 August 1999 / Received in revised form: 7 October 1999     

Plasmepsin inhibitors: design,synthesis, inhibitory studies and crystal structure analysis

Abstract: Plasmepsin group of enzymes are key enzymes in the life cycle of malarial parasites. As inhibition of plasmepsins leads to the parasite's death, these enzymes can be utilized as potential drug targets. Although many drugs are available, it has been observed that Plasmodium falciparum, the species that causes most of the malarial infections and subsequent death, has developed resistance against most of the drugs. Based on the cleavage sites of hemglobin, the substrate for plasmepsins, we have designed two compounds (p‐nitrobenzoyl‐leucine‐β‐alanine and p‐nitrobenzoyl‐leucine‐isonipecotic acid), synthesized them, solved their crystal structures and studied their inhibitory effect using experimental and theoretical (docking) methods. In this paper, we discuss the synthesis, crystal structures and inhibitory nature of these two compounds which have a potential to inhibit plasmepsins.     

外周血出现裂殖体非重症恶性疟1例分析

2020年1月腾冲市报告的1例非洲输入性恶性疟病例,曾到刚果金务工,自述在国外期间曾患疟疾,于回国途中发病。实验室检查白细胞3.89×10⁹/L,血红蛋白141 g/L,血小板75×10⁹/L,丙氨酸转氨酶188 U/L,天门冬氨酸转氨酶110 U/L,总胆红素29.3 μmol/L,血糖6.66 mmol/L,尿素氮3.8 mmol/L,肌酐95 μmol/L。其血涂片显微镜下可见环状体、大滋养体、未成熟裂殖体,疟原虫密度54 846 个/μL血,环状体占86.38%（8 640/10 002）、大滋养体占13.51%（1 351/10 002）、裂殖体占0.11%（11/10 002）,PCR基因检测确诊为恶性疟,经抗疟及对症支持治疗后痊愈。恶性疟外周血中出现裂殖体期原虫较少见,镜检时应注意与其他疟原虫鉴别。