恶性疟原虫氯喹敏感株与抗性株对青蒿素类药物体外敏感性的研究

目的 测定恶性疟原虫氯喹敏感株与抗性株对青蒿素类药物的体外敏感性. 方法 运用体外微量法与酶联免疫吸附试验(enzyme-linked immunosorbent assay,ELISA)测定青蒿琥酯、蒿甲醚及双氢青蒿素等3种青蒿素类抗疟药物对体外培养的恶性疟原虫氯喹敏感株与氯喹抗性株的体外敏感性,并比较两种方法测定的IC50值. 结果 体外微量法测定的3种药物对恶性疟原虫氯喹敏感株的IC50值依次为3.12 nmol/L、4.30 nmol/L、2.18 nmol/L,对恶性疟原虫氯喹抗性株的IC50值依次为4.31nmol/L、3.90 nmol/L、3.17 nmol/L;同时,将体外微量法与ELISA法所获的结果进行相关性分析,两种方法结果基本一致(r2=0.93,P＜0.001). 结论 恶性疟原虫氯喹抗性株对青蒿素类药物无明显的交叉抗性;ELISA法可用于恶性疟原虫对抗疟药物的体外敏感性检测.     

泰国的伯氨喹耐药性间日疟

伯氨喹是能杀灭间日疟原虫肝内休眠体、预防复发从而根治间日疟的唯一药物。在泰国,间日疟原虫引起的感染约占疟疾的50％;在经标准氯喹、伯氨喹合并治疗过的病例中,原虫血症复现率高达18％。本文根据曼谷热带病医院间日疟住院病例资料分析了泰国间日疟原虫对伯氨喹的耐药情况。     

闽北地区间日疟原虫对氯喹敏感性的调查

<正> 间日疟原虫对氯喹尚无抗性的征象,但只用氯喹治疗或氯喹加伯喹治疗间日疟原虫病人的复发率各 地报道不一。巴布新几内亚的溪桑株间日疟和一些泰国株间日疟已需用高于常用量的伯喹治疗。故于疟疾流行季节对闽北的建阳、崇安县进行调查及测试。     

高效液相色谱法测定人体血中氯喹含量

为了深入了解氯喹药代动力学有关情况,用高效液相色谱检测4名志愿者口服氯喹总量分别为600mg、600mg、900mg和1200mg后,血药浓度168h后尚有141ug/L、134ug/L、208ug/L和298ug/L,均明显高于有效杀灭疟原虫20ug/L浓度,用单剂600mg和首日300mg氯喹治疗间日疟现症病人各1例,追踪观察28h均无症状复发和原虫再现,获得痊愈。结果表明口服氯喹在人体内清除非常缓慢,维持有效杀灭疟原虫时间长,是治疗间日疟、三日疟和卵型疟的首选药。     

中缅边境西段缅甸恶性疟原虫对氯喹、青蒿琥酯及咯萘啶的敏感性体外测定

应用Rieckmann体外微量法测得中缅边境西段缅甸境内感染的恶性疟原虫对氯喹及我国抗疟新药青蒿琥酯及咯萘啶的抗性率分别为100％、14.3％及19.0％,半数抑制量(ID_(50)依次为249.5、4.2及12.1nmol/L。3例抗青蒿琥酯恶性疟原虫对氯喹和咯萘啶的ID_(50)分别为335.6nmol/L和43.1nmol/L;4例抗咯萘啶恶性疟原虫对氯喹和青蒿琥酯的ID_(50)分别为260.1nmol/L和5.0nmol/L。结果显示抗青蒿琥酯恶性疟原虫对咯萘啶及氯喹有明显的交叉抗性;抗咯萘啶恶性疟原虫对青蒿琥酯无交叉抗性。当地恶性疟原虫对氯喹的抗性程度明显高于云南南部恶性疟原虫,但对其它2种药物的敏感性则无明显差别,提示当地恶性疟原虫对青蒿琥酯及咯萘啶无交叉抗性。     

高效液相色谱法测定人体血中氯喹含量

为了深入了解氯喹药代动力学有关情况,用高效液相色谱检测4名志愿者口服氯喹总量分别为600mg、600mg、900mg和1200mg后,血药浓度168h后尚有141μg/L、134μg/L、208μg/L和298μg/L,均明显高于有效杀灭疟原虫20μg／L浓度。用单剂600mg和首日600mg,次日300mg氯喹治疗间日疟现症病人各1例,追踪观察28h均无症状复发和原虫再现,获得痊愈。结果表明口服氯喹在人体内清除非常缓慢,维持有效杀灭疟原虫时间长,是治疗间日疟、三日疟和卵型疟的首选药。     

缅甸拉咱市氯喹治疗间日疟的敏感性评价

缅甸拉咱市单纯间日疟原虫感染者48例分为氯喹A方案组（26例）和B方案组（22例）,分别采用成人总剂量1 200 mg （第1天顿服600 mg,第2、3天300 mg/d）和1 500 mg（第1天顿服750 mg,第2、3天375 mg/d）的三天疗法治疗。于服药当天、服药后第1、2、3、7、14、21和28天采集指血或耳垂血制作厚、薄血涂片检查疟原虫,测量体温和观察药物不良反应。氯喹治疗后,两组病例血内无性体原虫3 d内全部阴转。第28天随访治愈率为100%。结果表明,缅甸拉咱市的间日疟病例对氯喹治疗均敏感,该边境地区间日疟病例可采用氯喹进行临床治疗。     

印度加尔各答和奥里萨地区的间日疟原虫氯喹敏感性调查

自从 1 989年在巴布亚新几内亚地区发现间日疟原虫氯喹耐药性以来 ,在西南太平洋地区、印尼亦相继有报道。 1 995年印度也发现了氯喹耐药性间日疟病例。近十年来 ,印度卫生部门提倡对轻症、无并发症的疟疾患者都使用氯喹治疗 ,致使医生在处理发热患者时未经必要的辅助检查就常规用氯喹 ,这就使得印度部分地区恶性疟原虫对氯喹耐药性十分严重。Nandy等认为 1 995年在印度孟买报道的两例氯喹耐药性间日疟病例尚不确定 ,两个病例在氯喹治疗的第 3天都已有 6 8%～ 78%的疟原虫被清除 ,其中有一例在第 3天改用磺胺多辛 乙胺嘧啶进行治疗。由于…     

间日疟原虫氯喹抗性研究进展李

疟疾仍然是一个严重危害人类健康的公共卫生问题, 尤其多见于发展中国家。随着认识的深入, 间日疟也获得 越来越多的重视。有效的药物治疗是控制疟疾甚至消除疟疾的基石, 近年来已有越来越多的间日疟原虫氯喹抗性报道, 间日疟原虫氯喹抗性已成为间日疟防治中一个备受关注的问题。本文就间日疟原虫氯喹抗性的分布现状、 体内外检测方 法和分子检测标志物研究进展进行初步总结。     

氯喹在试管内对间日疟原虫红细胞内期无性体发育的影响

本实验的目的主要是:1)研究间日疟原虫红细胞内期无性体在试管中的发育情况;2)观察加入氯喹后对其发育有无抑制作用;3)找出可以作为鉴别原虫正常发育和药物抑制作用的定量指标的原虫形态特征或判断标准;4)得以了解应用这种方法测定间日疟原虫红细胞内期无性体对氯喹的敏感性的可能性。以13例出现间日疟无性体原虫血症者的血液作试验。在诊断并鉴定虫种后,用抗疟药治疗之前,从患者静脉采血。体外试验的方法与Riechmann等介绍的方法相似,即     

云南省恶性疟原虫对氯喹、氨酚喹、哌喹、甲氟喹、奎宁敏感性的体外测定

目的：了解云南省恶性疟原虫对氯喹、氨酚喹、哌喹、甲氟喹及奎宁的敏感性。方法：采用Ｒｉｅｃｋｍａｎｎ体外微量法测定采自云南省瑞丽１１个县、市的恶性疟原虫对以上药物的敏感性。结果：云南省南部、东南部及西部恶性疟原虫对氯喹抗性率分别为９６．７％、７８．９％及９５．７％,ＩＤ５０依次为１２５ｎｍｏｌ／Ｌ、１３６ｎｍｏｌ／Ｌ、及１７６ｎｍｏｌ／Ｌ;对氯酚喹的抗性率分别为１００％、８５．３％及８８．９％,ＩＤ５０依次为５２ｎｍｏｌ／Ｌ、５４ｎｍｏｌ／Ｌ及７２ｎｍｏｌ／Ｌ;对奎宁均为敏感,ＩＤ５０依次为４８０ｎｍｏｌ／Ｌ、３５２ｎｍｏｌ／Ｌ及６０８ｎｍｏｌ／Ｌ。南部及东南部原虫对哌喹的抗性率分别为６８及８８ｎｍｏｌ／Ｌ;结论：云南省恶性疟原虫对４－氨基喹啉类药物普遍产生抗性,其抗性程度来自滇西及其相连的缅甸感染的疟原虫明显高于滇东南;对奎宁及甲氟喹敏感。氯喹、氨酚喹及哌喹目前已不适应于云南恶性疟的治疗     

Amplification of pvmdr1 associated with multidrug-resistant Plasmodium vivax

BACKGROUND: Multidrug-resistant strains of Plasmodium vivax are emerging in Southeast Asia. METHODS: In vitro drug susceptibility and pvmdr1 genotype were determined in P. vivax field isolates from Indonesia and Thailand. RESULTS: Increased pvmdr1 copy number was present in 21% of isolates from Thailand (15/71) and none from Indonesia (0/114; P < .001). Compared with Indonesian isolates, the median IC(50) of Thai isolates was lower for chloroquine (36 vs. 114 nmol/L; P < .001) but higher for amodiaquine (34 vs. 13.7 nmol/L; P = .032), artesunate (8.33 vs. 1.58 nmol/L; P < .001), and mefloquine (111 vs. 9.87 nmol/L; P < .001). In 11 cryopreserved Thai isolates, those with increased pvmdr1 copy number had a higher IC(50) for mefloquine (78.6 vs. 38 nmol/L for single-copy isolates; P = .006). Compared with isolates with the wild-type allele, the Y976F mutation of pvmdr1 was associated with reduced susceptibility to chloroquine (154 nmol/L [range, 4.6-3505] vs. 34 nmol/L [range, 6.7-149]; P < .001) but greater susceptibility to artesunate (1.8 vs. 9.5 nmol/L; P = .009) and mefloquine (14 vs. 121 nmol/L; P < .001). CONCLUSIONS: Amplification of pvmdr1 and single-nucleotide polymorphisms are correlated with susceptibility of P. vivax to multiple antimalarial drugs. Chloroquine and mefloquine appear to exert competitive evolutionary pressure on pvmdr1, similar to that observed with pfmdr1 in Plasmodium falciparum.     

In vitro anti-malarial drug susceptibility of temperate Plasmodium vivax from central China

In the face of recent increase of Plasmodium vivax malaria in central China, we conducted a study to evaluate in vitro susceptibility of temperate-zone P. vivax parasites to antimalarial drugs. During 2005-2006, in vitro drug susceptibility was measured for 42 clinical P. vivax isolates by using a schizont maturation inhibition technique. Geometric means of 50% inhibitory concentrations (IC(50)s) and 95% confidence intervals (CIs) were 10.87 (4.50-26.26) ng/mL for chloroquine, 4.21 (1.88-9.42-8) ng/mL for mefloquine, 11.82 (6.20-22.56) ng/mL for quinine, 0.13 (0.09-0.20) ng/mL for artesunate, 18.32 (8.08-41.50) ng/mL for pyrimethamine, and 17.73 (10.29-30.57) ng/mL for piperaquine. The IC(50) for chloroquine was lower than those obtained from isolates from Thailand and South Korea, suggesting that chloroquine remained effective against P. vivax malaria in central China. The results further indicated that temperate-zone P. vivax isolates from China were more susceptible to chloroquine, quinine, and mefloquine than isolates from Thailand.     

体外测定恶性疟原虫对七种抗疟药的敏感性

１９９２年应用体外微量法在中老边境测得我国境内恶性疟原虫对氯喹、哌喹、青蒿琥酯、蒿甲醚、蒿乙醚、还原青蒿素及咯萘啶抗性率，分别为９７．０％、９６．４％、１２．１％、１６．０％、６．２％、１２．５％、３４．５％；半数抑制量（ＩＤ５０）依次为１１９．０、３２０、７．２、２９５．０、７４．４、５．４及３１．９ｎｍｏｌ／Ｌ。老挝境内恶性疟原虫分离株对氯喹、哌喹及咯萘啶的抗性率分别为９／１０、８／１０及１／５；ＩＤ５０依次为１１４．０、１６６．９及１６．４ｎｍｏｌ／Ｌ；对青蒿琥酯、蒿甲醚、蒿乙醚及还原青蒿素均敏感，ＩＤ５０分别为５．０、９１．６、５６．７及４．４ｎｍｏｌ／Ｌ。结果提示境内外恶性疟原虫株对氯喹的抗性程度相似，但对哌喹的抗性程度境外明显低于境内。对青蒿琥酯、蒿甲醚、蒿乙醚及还原青蒿素的敏感性境外明显高于境内。     

Field evaluation in Kenya of a 48-hour in vitro test for Plasmodium falciparum sensitivity to chloroquine

A 48-hour in vitro test for determining the chloroquine sensitivity of Plasmodium falciparum isolates was evaluated in Kisumu and Malindi, Kenya. P. falciparum isolates from 14 children, aged 5 to 13 years, were studied. In vivo and 48-hour in vitro tests were done on all 14. Successful Rieckmann macro and micro in vitro tests for chloroquine sensitivity were completed in nine isolates each. All 14 infections cleared within 3 days of beginning chloroquine treatment, and none recrudesced during a 7-day (8 patients) or 28-day (6 patients) follow-up period. The three in vitro tests gave comparable results. Although all isolates tested were chloroquine sensitive in vitro, different response patterns were observed. In the 48-hour test, 10 isolates were inhibited at chloroquine concentration less than or equal to 0.03 nmol/ml medium. These isolates were inhibited by less than or equal to 0.5 nmol of chloroquine per ml blood in the Rieckmann macro test and by 2-6 pmol/well in the micro test. The other four isolates had response patterns intermediate between those of previously reported sensitive and resistant strains. Complete inhibition did not occur until chloroquine concentrations of greater than or equal to 0.03 nmol/ml medium in the 48-hour test, greater than or equal to 0.5 nmol/ml blood in the macro test, and 6 pmol/well in the micro test. The results demonstrate that the 48-hour test is a useful addition to existing in vivo and in vitro methods for determining the chloroquine sensitivity of P. falciparum in the field.     

中缅边境地区恶性疟原虫对氯喹、哌喹、咯萘啶敏感性的体外测定

目的了解中缅边境地区恶性疟原虫（Plasmodium falciparum）对氯喹、哌喹和咯萘啶敏感性的变化。方法 2009年9～12月在中缅边境的缅甸拉咱市采集了51份恶性疟血样,采用Rieckmann体外微量测定法进行药物敏感性测定。结果敏感性测定结果有效的42份血样中、其恶性疟原虫对氯喹、哌喹和咯萘啶的抗性率分别为95.2%、7.1%和54.8%,半数抑制量(ID₅₀)分别为320.5、128.2和96.0 nmol/L。在抗咯萘啶的23份血样中,对氯喹和哌喹的交叉抗性率分别为91.3%（21/23）和13.0%（3/23）;抗氯喹的40份血样中,对哌喹和咯萘啶的交叉抗性率分别为7.5%（3/40）和52.5%（21/40）;抗哌喹的3份血样中,对氯喹和咯萘啶的交叉抗性率均为100%。结论在缅甸拉咱市调查点流行的恶性疟原虫对氯喹已普遍产生抗性,约半数对咯萘啶具有抗性,多数对哌喹则敏感。     

Plasmodium vivax malaria in Southeast Iran in 1999-2001: establishing the response to chloroquine in vitro and in vivo

Chloroquine-resistant Plasmodium vivax is emerging in Oceania, Asia and Latin America. The drug sensitivity of P. vivax to chloroquine both in vivo and in vitro in the southern part of Iran was assessed; chloroquine-resistant Plasmodium falciparum has already been documented in this area. The in vitro sensitivity of 39 P. vivax isolates was assessed: the mean IC50 and IC90 were 189 ng/ml and 698 ng/ml blood respectively; for in vivo testing, all 39 vivax malaria patients were treated with a standard regimen of chloroquine and followed-up at 28 days: the mean parasite clearance time was 67.2 +/- 22.5 hours. The in vitro development of young parasites to mature schizonts in standard test medium was compared with that obtained in McCoy's 5A medium: no significant difference was observed. Synchronization of the blood-stage parasites was performed according to Lambros' method: the method was not suitable because it was detrimental to the parasites. A number of in vitro tests were performed using both our own laboratory-predosed microplates and WHO microplates: there was no significant difference between the results.     

云南省恶性疟原虫对青蒿素类药物及咯萘啶与氯喹敏感性的体外测定

目的 :了解恶性疟原虫对青蒿素类药物及咯萘啶与氯喹等抗疟药的敏感性。方法 :采用Rieckmann体外微量法检测。结果 :滇东南、滇南、老挝、滇西及缅甸恶性疟原虫对氯喹的抗性率为79%— 96% ,半数抑制量 ( ID50 )为 12 2— 2 4 0 nmol/L;对咯萘啶的抗性率为 2 0 %— 35% ,ID50 为16— 32 nmol/L ;来自老挝感染的恶性疟原虫对青蒿素类药物 (青蒿琥酯 ,还原青蒿素、蒿乙醚、蒿甲醚 )均敏感 ,其他各地抗性率为5%— 16%。结论 :云南恶性疟原虫对氯喹普遍存在抗性 ,大部分原虫对青蒿素类药物及咯萘啶敏感 ,但也有部分原虫产生了低度抗性。     

恶性疟原虫青蒿琥酯敏感株与抗性株对氯喹及氨酚喹敏感性的比较

目的： 了解恶性疟原虫抗青蒿琥酯株对氯喹及氨酚喹 （阿莫地喹） 有无交叉抗性及其与青蒿琥酯联合使用是否有增效作用。方法： 用Ｒｉｅｃｋｍ ａｎｎ 体外微量法比较青蒿琥酯敏感株与抗性株恶性疟原虫对氯喹和氨酚喹的敏感性。结果： 氯喹对青蒿琥酯敏感株与抗性株原虫的ＩＤ５０ 分别为９０．９ 及１１２．０ ｎｍ ｏｌ／Ｌ, ＩＤ９５ 均为３２０．０ｎｍ ｏｌ／Ｌ; 氨酚喹ＩＤ５０ 分别为５０．９ 及１３３．５ ｎｍ ｏｌ／Ｌ, ＩＤ９５ 均为３２０．０ ｎｍ ｏｌ／Ｌ。在联合用药组中, 青蒿琥酯及氯喹的完全抑制浓度（ＩＤ９５） 分别为３．２ 及２０．０ ｎｍ ｏｌ／Ｌ,为单用组的１／１２５ 和１／１６;青蒿琥酯及氨酚喹的ＩＤ９５ 分别为３．２ 及５．０ ｎｍ ｏｌ／Ｌ, 为单用组的１／１２５ 和１／６４。结论： 抗青蒿琥酯恶性疟原虫对氯喹、氨酚喹无明显交叉抗性,青蒿琥酯与这２ 种药物联用在体外测试有明显增效作用。