期刊文献+
共找到3,139篇文章
< 1 2 157 >
每页显示 20 50 100
The Relationship between the Plasmodium Falciparum Clearance and the Clinical Effect of the Case with Cerebral Malaria Treated with Artemisinin
1
作者 Guo-li Lin Hong Shi +3 位作者 Yuan-kai Wu Xiang-yong Li Jian-hua Huang Wei-min Ke 《国际感染病学(电子版)》 CAS 2014年第3期129-132,共4页
Malaria is 1 mosquito-borne disease,which is most commonly caused by a parasite called Plasmodium falciparum(P.falciparum).Cerebral malaria is the most severe neurological complication presented in
关键词 The Relationship between the plasmodium Falciparum Clearance and the Clinical Effect of the Case with Cerebral Malaria Treated with artemisinin RBC Figure Email
下载PDF
Therapeutic efficacy of artemisinin combination therapies and prevalence of S769N mutation in PfATPase6 gene of Plasmodium falciparum in Kolkata,India
2
作者 Pabitra Saha Arindam Naskar +9 位作者 Swagata Ganguly Sonali Das Subhasish K Guha Asit Biswas Dilip K Bera Pratip K Kundu Madhusudan Das Shrabanee Mullick Krishnangshu Ray Ardhendu K Maji 《Asian Pacific Journal of Tropical Medicine》 SCIE CAS 2013年第6期443-448,共6页
Objective:To study the in vivo efficacy of these two ACTs in the treatment of Plasmodium falciparum {P.falciparum malaria) in Kolkata and to detennine the prevalence of mutant S769N codon of the PfATPase6 gene among f... Objective:To study the in vivo efficacy of these two ACTs in the treatment of Plasmodium falciparum {P.falciparum malaria) in Kolkata and to detennine the prevalence of mutant S769N codon of the PfATPase6 gene among field isolates of P.falciparum collected from the study area. Methods:A total of 207 P.falciparum positive cases were enrolled randomly in two study arms and followed up for 42 days as per WHO(2009) protocol.A portion of PfATPase6 gene spanning codon S769N was amplified and sequenced by direct sequencing method.Results:It was observed that the efficacy of bodi the ACT regimens were highly effective in the study area and no mutant S769N was detected from any isolate.Conclusions:The used,combination AS+SP is effective and the other combination AM+I.F might be an alternative,if needed. 展开更多
关键词 ACTS plasmodium FALCIPARUM PfATPase6
下载PDF
Overview of the improvement of the ring-stage survival assay - a novel phenotypic assay for the detection of artemisinin-resistant Plasmodium falciparum 被引量:1
3
作者 Jie Zhang Guo-Hua Feng +3 位作者 Chun-Yan Zou Pin-Can Su Huai-E Liu Zhao-Qing Yang 《Zoological Research》 CAS CSCD 2017年第6期317-320,共4页
Artemisinin resistance in Plasmodium falciparum threatens the remarkable efficacy of artemisininbased combination therapies worldwide. Thus, greater insight into the resistance mechanism using monitoring tools is esse... Artemisinin resistance in Plasmodium falciparum threatens the remarkable efficacy of artemisininbased combination therapies worldwide. Thus, greater insight into the resistance mechanism using monitoring tools is essential. The ring-stage survival assay is used for phenotyping artemisinin-resistance or decreased artemisinin sensitivity. Here, we review the progress of this measurement assay and explore its limitations and potential applications. 展开更多
关键词 Malaria artemisinin Resistant phenotype Ring-stage survival assay IMPROVEMENT Application
下载PDF
A Comparative Study on the Efficacy of Some Artemisinin Combination Therapies on <i>Plasmodium berghei</i>in Swiss Albino Mice
4
作者 U. O. Georgewill O. O. Ebong 《Pharmacology & Pharmacy》 2012年第1期109-112,共4页
This study evaluated and compared the efficacy of five brands of Artemisinin Combination Therapies (ACTs);Dihydroartemisinin plus Piperaquine, Artesunate plus Amodiaquine, Artesunate plus Sulphadoxine/Pyrimethamine, A... This study evaluated and compared the efficacy of five brands of Artemisinin Combination Therapies (ACTs);Dihydroartemisinin plus Piperaquine, Artesunate plus Amodiaquine, Artesunate plus Sulphadoxine/Pyrimethamine, Artemether plus lumefantrine and Artesunate plus mefloquine combinations in vivo in P.berghei infected swiss albino mice. The experimental animals were pre-screened to rule out infection. All drugs were administered as clinical doses for the curative test and the Mean Percentage Parasitemia level assessed daily for seven days and on day 60. The results showed that all the drugs were effective with artesunate plus amodiaquine combination being the most efficacious followed by dihydroartemisinin plus piperaquine and artesunate plus sulphadoxine plus pyrimethamine combinations followed by artesunate plus mefloquine combination and artemether plus lumefantrine combination which was the least efficacious. Results on day 60 showed increasing parasitemia levels in mice which received Artemether plus lumefantrine and Artesunate plus mefloquine combinations which is indicative of recrudescence. The results of this study showed that the ACT’s used in the experiment were all efficacious. The possible development of resistance to some of the drugs was shown by the increasing parasitemia levels following treatment with artesunate plus lumefantrine and artesunate plus mefloquine combinations on day 60. 展开更多
关键词 EFFICACY Malaria artemisinin Combination Therapies RECRUDESCENCE Resistance
下载PDF
Resistance of <i>Plasmodium falciparum</i>to Sulfadoxine-Pyrimethamine (<i>Dhfr</i>and <i>Dhps</i>) and Artemisinin and Its Derivatives (K13): A Major Challenge for Malaria Elimination in West Africa
5
作者 Valérie BBazie Abdoul Karim Ouattara +5 位作者 Tani Sagna TegwindéRebeca Compaore Serge Théophile Soubeiga PegdwendéAbel Sorgho Albert Théophane Yonli Jacques Simpore 《Journal of Biosciences and Medicines》 2020年第2期82-95,共14页
The spread of resistance to antimalarials is a major public health problem worldwide and especially in sub-Saharan Africa where the highest morbidity and mortality rates are found with a critical scarcity of data on r... The spread of resistance to antimalarials is a major public health problem worldwide and especially in sub-Saharan Africa where the highest morbidity and mortality rates are found with a critical scarcity of data on resistance. The objective of this review is to describe the mutations in the pfdhfr, pfdhps and k13 genes associated with resistance to artemisinin and Sulfadoxine-Pyrimethamine reported in West Africa during the decade 2007 to 2017 followed by a meta-analysis of their prevalence. A bibliographic search on the MEDLINE, PubMed, EMBASE and Sciences Direct databases made it possible to find 405 scientific papers relating to resistance to artemisinin and to Sulfadoxine-Pyrimethamine during the period 2007-2017. The analysis has concerned 217 scientific articles after the elimination of duplicates with 57 articles included in this review after the examination of titles and abstracts. The results of the present review show that the dhfr and dhps mutants are widespread in sub-Saharan Africa. Although, Kelch 13 mutants from Southeast Asia associated with artemisinin resistance are still absent in West Africa, studies have reported the presence of synonymous or non-K13 mutations correlated with a delay in parasite clearance in Burkina Faso (2.26%), Senegal (5.5%) and Togo (1.8%). The increased prevalence of dhfr and dhps mutants in West Africa could jeopardize its use for intermittent preventive treatment in the near future. Despite the absence of strains resistant to artemisinin-based combination therapy in the West African region, increased surveillance is necessary to prevent the rapid occurrence of possible resistance, especially in the context of synonymous or non-K13 mutations correlated with a delay in parasitic clearance. 展开更多
关键词 Resistance Mutations artemisinin SULFADOXINE-PYRIMETHAMINE WEST AFRICA
下载PDF
Noscapine shows antimalarial activity against Plasmodium falciparum 3D7,its clinical isolate Pf140/SS,and Plasmodium berghei ANKA
6
作者 Swaraj Kumar Babu Sameer Maharana +7 位作者 Satyaranjan Chhatria Dibya Ranjan Sahoo Ashirbad Nanda Satish Kanhar Prativa KBehera Sanjib Mohanty Pradeep Kumar Naik Praveen Kishore Sahu 《Asian Pacific Journal of Tropical Biomedicine》 SCIE CAS 2024年第8期350-358,共9页
Objective:To evaluate the antimalarial activity of noscapine against Plasmodium falciparum 3D7 strain(Pf3D7),its clinical isolate(Pf140/SS),and Plasmodium berghei ANKA(PbA).Methods:Using ring-stage survival assay,phen... Objective:To evaluate the antimalarial activity of noscapine against Plasmodium falciparum 3D7 strain(Pf3D7),its clinical isolate(Pf140/SS),and Plasmodium berghei ANKA(PbA).Methods:Using ring-stage survival assay,phenotypic assessments,and SYBR-green-based fluorescence assay,the antimalarial activities of noscapine were assessed compared with dihydroartemisinin(DHA)in in vivo and in vitro studies.In addition,hemolysis and cytotoxicity tests were carried out to evaluate its safety.RT-PCR assay was also conducted to determine the effect of noscapine on papain-like cysteine protease Plasmodium falciparum falcipain-2(PfFP-2).Results:The antimalarial efficacy of noscapine against Pf3D7 and Pf140/SS was comparable to DHA,with IC50 values of(7.68±0.88)and(5.57±0.74)nM/mL,respectively,and>95%inhibition of PbA infected rats.Noscapine also showed a safe profile,as evidenced by low hemolysis and cytotoxicity even at high concentrations.Moreover,PfFP-2 expression was significantly inhibited in both noscapine-treated Pf3D7 and Pf140/SS(P<0.01).Conclusions:Noscapine has antimalarial properties comparable to standard antimalarial DHA with better safety profiles,which may be further explored as a therapeutic candidate for the treatment of malaria. 展开更多
关键词 MALARIA plasmodium falciparum plasmodium berghei NOSCAPINE ANTIMALARIAL DIHYDROartemisinin CYTOTOXICITY Falcipain-2
下载PDF
Genetic diversity of the S-type small subunit ribosomal RNA gene of Plasmodium knowlesi isolates from Sabah,Malaysian Borneo and Peninsular Malaysia
7
作者 Eric Tzyy Jiann Chong Joveen Wan Fen Neoh +3 位作者 Tiek Ying Lau Kek Heng Chua Yvonne Ai-Lian Lim Ping-Chin Lee 《Asian Pacific Journal of Tropical Medicine》 SCIE CAS 2024年第2期84-90,共7页
Objective:To determine the genetic diversity of Plasmodium(P.)knowlesi isolates from Sabah,Malaysian Borneo and Peninsular Malaysia,targeting the S-type SSU rRNA gene and including aspects of natural selection and hap... Objective:To determine the genetic diversity of Plasmodium(P.)knowlesi isolates from Sabah,Malaysian Borneo and Peninsular Malaysia,targeting the S-type SSU rRNA gene and including aspects of natural selection and haplotype.Methods:Thirty-nine blood samples infected with P.knowlesi were collected in Sabah,Malaysian Borneo and Peninsular Malaysia.The S-type SSU rRNA gene was amplified using polymerase chain reaction,cloned into a vector,and sequenced.The natural selection and haplotype of the S-type SSU rRNA gene sequences were determined using DnaSP v6 and illustrated using NETWORK v10.This study's 39 S-type SSU rRNA sequences and eight sequences from the Genbank database were subjected to phylogenetic analysis using MEGA 11.Results:Overall,the phylogenetic analysis showed no evidence of a geographical cluster of P.knowlesi isolates from different areas in Malaysia based on the S-type SSU rRNA gene sequences.The S-type SSU rRNA gene sequences were relatively conserved and with a purifying effect.Haplotype sharing of the S-type SSU rRNA gene was observed between the P.knowlesi isolates in Sabah,Malaysian Borneo,but not between Sabah,Malaysian Borneo and Peninsular Malaysia.Conclusions:This study suggests that the S-type SSU rRNA gene of P.knowlesi isolates in Sabah,Malaysian Borneo,and Peninsular Malaysia has fewer polymorphic sites,representing the conservation of the gene.These features make the S-type SSU rRNA gene suitable for comparative studies,such as determining the evolutionary relationships and common ancestry among P.knowlesi species. 展开更多
关键词 plasmodium knowlesi S-type small subunit ribosomal RNA Genetic diversity Natural selection HAPLOTYPE
下载PDF
In silico antiplasmodial effects of phytocompounds derived from Andrographis paniculata on validated drug targets of different stages of Plasmodium falciparum
8
作者 Funmilayo I.D.Afolayan Sayo Ebenezer Oladokun 《Infectious Diseases Research》 2024年第2期1-11,共11页
Background:Andrographis paniculata has been widely reported as an herbal plant for malaria treatment.The increasing rate of resistance to recommended antimalarial drugs has justified the need for a continuous search f... Background:Andrographis paniculata has been widely reported as an herbal plant for malaria treatment.The increasing rate of resistance to recommended antimalarial drugs has justified the need for a continuous search for new and more potent drugs that target all stages of the Plasmodium falciparum life cycle from natural plant sources.This study aimed to determine the antiplasmodial effect of phytocompounds derived from A.paniculata on the stages of plasmodium falciparum.Methods:Phytocompounds from A.paniculata were identified by Gas Chromatography-Mass Spectrophotometry(GCMS)analysis.The phytocompounds were screened for their druggability using Lipinski’s rule of five and subjected to Absorption,Distribution,Metabolism,Excretion,Toxicity(ADMET)and druglikeness analysis.The phytocompounds were docked against some validated drug targets at different stages of Plasmodium falciparum(hepatic,asexual,sexual,and vector targets)using PyRx software to analyze the inhibitory potential and protein-ligand interaction.Thereafter,the stability and flexibility of the best complexes were assessed through molecular dynamics simulations at 50ns using WebGRO.Result:The 7a-Isopropenyl-4,5-dimethyloctahydroinden-4-yl exhibited a higher binding affinity and better stability throughout the simulation period with P.falciparum dihydrofolate reductase-thymidylate synthase and Plasmodium falciparum M1 alanyl aminopeptidase for asexual blood stage and gametocyte stage of Plasmodium falciparum,respectively than the existing drugs.Meanwhile,N-Ethyl-3-methoxy-4-methylphenethylamine was also found to have a higher binding affinity and more stability throughout the simulation period with P.falciparum purine nucleoside phosphorylase and Plasmodium falciparum gametocyte surface protein for Hepatic schizonts stage of Plasmodium falciparum and gametocyte transmission blocking stage,respectively,than the existing drugs.Conclusion:The 7a-Isopropenyl-4,5-dimethyloctahydroinden-4-yl and N-Ethyl-3-methoxy-4 methylphenethylamine from A.paniculata are predicted as an antimalarial drug candidate.Thus,it is recommended that in vitro and in vivo bioassays be conducted on these hit compounds to validate these predictions. 展开更多
关键词 plasmodium falciparum drug targets Andrographis paniculata molecular docking molecular dynamics
下载PDF
Association of ABO blood group and Plasmodium falciparum malaria in Dore Bafeno Area,Southern Ethiopia 被引量:10
9
作者 Tewodros Zerihun Abraham Degarege Berhanu Erko 《Asian Pacific Journal of Tropical Biomedicine》 SCIE CAS 2011年第4期289-294,共6页
Objective:To assess the distribution of ABO blood group and their relationship with Plasmodium falciparum(P.falciparum) malaria among febrile outpatients who sought medical attention at Dore Bafeno Health Center,South... Objective:To assess the distribution of ABO blood group and their relationship with Plasmodium falciparum(P.falciparum) malaria among febrile outpatients who sought medical attention at Dore Bafeno Health Center,Southern Ethiopia.Methods:A total of 269 febrile outpatients who visited Dore Bafeno Health Center,Southern Ethiopia,were examined for malaria and also tested for ABO blood groups in January 2010.The blood specimens were collected by finger pricking,stained with Geimsa,and examined microscopically.Positive cases of the parasitemia were counted.CareStart^(TM) Malaria PflPv Combo was also used to test the blood specimens for malaria.ABO blood groups were determined by agglutination test using ERYCLONE antisera.Data on socio-demographic characteristics and treatment status of the participants were also collected.Chi-square and ANOVA tests were used to assess the difference between frequencies and means,respectively.Results:Out of a total of 269 participants,178(66.2%) febrile patients were found to be infected with Plasmodium parasites,among which 146(54.3%),28(10.4%),and 4(1.5%) belonged to P.falciparum,P.vivax,and mixed infections,respectively.All febrile patients were also tested for ABO blood groups and 51.3%,23.5%,21.9%and 3.3%were found to be blood types of 0,A,B and AB,respectively.Both total malaria infection and P.falciparum infection showed significant association with blood types(P<0.05).The proportion of A or B but not 0 phenotypes was higher(P<0.05) in individuals with P.falciparum as compared with non-infected individuals.The chance of having P.falciparum infection in patients with blood groups A,B and AB was 2.5,2.5 and 3.3times more than individuals showing blood 0 phenotypes,respectively.The mean P.falciparum malaria parasitemia for blood groups A,B,AB,and 0 were 3 744/μ L,1 805/ μ L,5 331/μ L,and1 515/μ L,respectively(P<0.01).Conclusions:The present findings indicate that individuals of blood groups A,B and AB are more susceptible to P.falciparum infection as compared with individuals of blood group O.Nevertheless,further in depth studies are required to clearly establish the role that ABO blood group plays in P.falciparum malaria. 展开更多
关键词 plasmodium falciparum malaria ABO blood groups Ethiopia Febrile outpatient PARASITEMIA ASSOCIATION Blood specimen Geimsa CareStart^(TM) Malaria Pf/Pv Combo ERYCLONE antisera plasmodium parasite Malaria infection Distribution Agglutination test plasmodium vivax
下载PDF
Reversal of tamoxifen resistance by artemisinin in ER+breast cancer:bioinformatics analysis and experimental validation 被引量:1
10
作者 ZHILI ZHUO DONGNI ZHANG +4 位作者 WENPING LU XIAOQING WU YONGJIA CUI WEIXUAN ZHANG MENGFAN ZHANG 《Oncology Research》 SCIE 2024年第6期1093-1107,共15页
Breast cancer is the leading cause of cancer-related deaths in women worldwide,with Hormone Receptor(HR)+being the predominant subtype.Tamoxifen(TAM)serves as the primary treatment for HR+breast cancer.However,drug re... Breast cancer is the leading cause of cancer-related deaths in women worldwide,with Hormone Receptor(HR)+being the predominant subtype.Tamoxifen(TAM)serves as the primary treatment for HR+breast cancer.However,drug resistance often leads to recurrence,underscoring the need to develop new therapies to enhance patient quality of life and reduce recurrence rates.Artemisinin(ART)has demonstrated efficacy in inhibiting the growth of drug-resistant cells,positioning art as a viable option for counteracting endocrine resistance.This study explored the interaction between artemisinin and tamoxifen through a combined approach of bioinformatics analysis and experimental validation.Five characterized genes(ar,cdkn1a,erbb2,esr1,hsp90aa1)and seven drug-disease crossover genes(cyp2e1,rorc,mapk10,glp1r,egfr,pgr,mgll)were identified using WGCNA crossover analysis.Subsequent functional enrichment analyses were conducted.Our findings confirm a significant correlation between key cluster gene expression and immune cell infiltration in tamoxifen-resistant and-sensitized patients.scRNA-seq analysis revealed high expression of key cluster genes in epithelial cells,suggesting artemisinin’s specific impact on tumor cells in estrogen receptor(ER)-positive BC tissues.Molecular target docking and in vitro experiments with artemisinin on LCC9 cells demonstrated a reversal effect in reducing migratory and drug resistance of drug-resistant cells by modulating relevant drug resistance genes.These results indicate that artemisinin could potentially reverse tamoxifen resistance in ER-positive breast cancer. 展开更多
关键词 artemisinin Tamoxifen resistance Breast cancer
下载PDF
食蟹猴疟原虫 (Plasmodium cynomolgi)中一个真核翻译起始因子4A(eIF-4A)同源蛋白的cDNA克隆、表达和ATP酶活性测定(英文) 被引量:4
11
作者 宋平 张竞男 +1 位作者 胡珈瑞 李奎 《中国生物化学与分子生物学报》 CAS CSCD 北大核心 2004年第3期294-304,共11页
真核翻译起始因子 4A(eukaryoticinitiationfactor 4A ,eIF 4A)是DEAD盒蛋白家族的ATP依赖性的RNA解旋酶类中的一个原型成员 .它在真核细胞的蛋白质合成的起始过程中起着关键性作用 .通过PCR扩增和放射探针杂交相结合的方法筛选食蟹猴... 真核翻译起始因子 4A(eukaryoticinitiationfactor 4A ,eIF 4A)是DEAD盒蛋白家族的ATP依赖性的RNA解旋酶类中的一个原型成员 .它在真核细胞的蛋白质合成的起始过程中起着关键性作用 .通过PCR扩增和放射探针杂交相结合的方法筛选食蟹猴疟原虫 (Plasmodiumcynomolgi)的cDNA文库 ,克隆了一个eIF 4A同源蛋白的完整cDNA序列 ,命名为CH1F .CH1F全长 1 75 3bp ,包含一个1 1 97bp的完整阅读框 ,推测编码一个由 398个氨基酸组成的蛋白 .对CH1F的蛋白序列用BlastP进行搜索和分析 ,提示它应该是DEAD盒家族的一个eIF 4A同源蛋白 ;用DNAStar将其与许多典型的DEAD盒蛋白序列进行比对分析 ,结果显示 :比起其它的DEAD盒蛋白 ,它与eIF 4A或eIF 4A的同源蛋白具有更高的同源性和更多序列上的相似结构域 .将包含完整阅读框的片段亚克隆进表达载体pET 2 8a (+) ,在大肠杆菌DH5α中表达 ,产生的融合蛋白大小在 4 5kD左右 .对该融合蛋白进行纯化、重新折叠和初步鉴定 .ATP酶活性检测显示 ,该融合蛋白只有很低的ATP酶活性 ,而且它的ATP酶活性似乎不依赖于核酸底物 .对这一检测结果给出 3种可能的原因 .这一检测结果与根据序列分析得到的推论———CH1F蛋白可能是一个eIF 展开更多
关键词 真核翻译起始因子4A(eukaryotic initiation factor 4A eIF-4A) RNA解旋酶 ATP酶 食蟹猴 疟原虫(plasmodium cynomolgi)
下载PDF
Selective Effect of Qinghaosu on Different Stages of Plasmodium falciparum in Vitro 被引量:1
12
作者 叶祖光 CarolynDoak KnoxVanDyke 《Journal of Chinese Pharmaceutical Sciences》 CAS 1993年第1期64-68,共5页
Using highly synchronous cultures of Plasmodium falciparum in vitro,the susceptibi- lity of the different stages of the intraerythrocytic parasites to Qinghaosu (QHS) was assessed.The anti- parasitic effect of QHS was... Using highly synchronous cultures of Plasmodium falciparum in vitro,the susceptibi- lity of the different stages of the intraerythrocytic parasites to Qinghaosu (QHS) was assessed.The anti- parasitic effect of QHS was measured by comparing the changes of irradiation of^3 H-hypoxanthine in- corporated into the nucleic acids of parasites exposed to various concentrations of QHS at different stages of growth.It was found that the trophozoite stage of the parasite was the most sensitive to QHS, whereas the early ring stage was the least sensitive,and the sensitivities of the late ring and schizont stages fell between those of the early ring and trophozoite stages.The results revealed the correlation of stage-dependent effects of QHS with the blockade of the protein metabolism of the parasite. 展开更多
关键词 Qinghaosu(artemisinin) Antimalarial drug plasmodium falciparum MALARIA
下载PDF
Antimalarial activity of a novel series of artemisinin-derived 1, 2, 3-triazole dimers
13
作者 Kabita Gogoi Gokul Baishya +10 位作者 Biswajit Saikia Nabin Chandra Barua Chandrajit Dohutia Akalesh Kumar Verma Anil Prakash ICMR-Regional Medical Research Centre,N.E. CSIR-North-East Institute of Science and Technology Digboi College,Chemistry Department Pratiksha Institute of Pharmaceutical Scinces Cotton University,Zoology Department ICMR-National Institute for Research in Environmental Health 《Asian Pacific Journal of Tropical Medicine》 SCIE CAS 2019年第5期195-203,共9页
Objective: To obtain suitable artimisinin-based drug candidates with high antimalarial activity.Methods: Three different reaction schemes were used to synthesize a total of 15 artemisininbased compounds.The first synt... Objective: To obtain suitable artimisinin-based drug candidates with high antimalarial activity.Methods: Three different reaction schemes were used to synthesize a total of 15 artemisininbased compounds.The first synthetic scheme involved the synthesis of diazido aliphatic and aromatic compounds from commercially available dihalides and azido derivatives of artemisinin.The second scheme consisted of the reaction of dibromoaliphatic compounds with sodium azide in dimethylformamide which yielded the desired compounds.Artemisinin-based compounds on treatment with sodium azide and bromotrimethylsilane in dichloromethane produced the most potent compound GB-2.Another potent compound GB-1 was synthesized from artemisinin by treatment with alcohols in the presence of Aberlyst-15 in anhydrous dichloromethane.The third scheme involved the Huisgen 1,3-dipolar cycloaddition between the synthesized aliphatic and aromatic diazides and two alkyne derivatives of artemisinin to obtain the desired artemisinin dimers with average yields.Results: The best in vitro antiplasmodial activity was shown by the compound GB-2 registering IC_(50) value 0.066 μg/mL against chloroquine-sensitive and 0.865 μg/mL against chloroquineresistant strains of Plasmodium falciparum.It suppressed 59.0% parasitaemia in vivo of rodent malaria parasite Plasmodium berghei in Swiss albino model at 50 μg/kg body weight dosage.Molecular docking interactions of Plasmodium falciparum ATP6(PfATP6) protein revealed strong bonding of GB-2 with Thr255 residue which is likely to be the reason for excellent antimalarial activity of this compound.Conclusion: Two compounds GB-1 and GB-2 exhibited excellent in vitro antiplasmodial activity and fair in vivo antimalarial activity.Of the two, GB-2 showed better activity which could be attributed to its strong bonding interactions with Thr255 as evidenced from the molecular docking study.Study helped in identifying artemisinin analogues possessing good antimalarial properties and further research in structural alterations of the selected molecules should be carried out which may result in obtaining potent drug candidates against the malarial parasite. 展开更多
关键词 Antimalarial activity artemisinin derivatives Huisgen reaction Triazole dimers plasmodium berghei plasmodium falciparum Molecular docking
下载PDF
Comparison of microscopy and PCR for the detection of human Plasmodium species and Plasmodium knowlesi in southern Myanmar
14
作者 Thu Zar Han Kay Thwe Han +3 位作者 Kyin Hla Aye Thaung Hlaing Kyaw Zin Thant Indra Vythilingam 《Asian Pacific Journal of Tropical Biomedicine》 SCIE CAS 2017年第8期680-685,共6页
To determine the distribution of Plasmodium (P) species including Plasmodium knowlesi and to compare the specificity and sensitivity of microscopy with nested PCR in malaria diagnosis.MethodsThe study was conducted in... To determine the distribution of Plasmodium (P) species including Plasmodium knowlesi and to compare the specificity and sensitivity of microscopy with nested PCR in malaria diagnosis.MethodsThe study was conducted in Kawthaung, southern Myanmar. Ninety clinically suspected malaria patients were screened for malaria by Giemsa stained microscopy and confirmed by nested PCR.ResultsAmong the participants, 57 (63.3%) were positive and 33 (36.7%) were negative by microscopy. Of positive samples, 39 (68.4%) were Plasmodium falciparum, 17 (29.8%) Plasmodium vivax and 1 (1.8%) Plasmodium malariae, whereas 59-amplified by PCR were 40 (67.8%), 18 (30.5%) and 1 (1.7%) respectively. PCR amplified 2 microscopy negative samples. Two samples of P. falciparum detected by microscopy were amplified as P. vivax and vice versa. All samples were negative for Plasmodium ovale, P. knowlesi and mixed infections. Microscopy had a very good measure of agreement (κ = 0.95) compared to nested PCR. Sensitivity and specificity of microscopy for diagnosis of P. falciparum were 92.5% (95% CI: 79.6-98.4) and 96.0% (95% CI: 86.3-99.5) respectively, whereas for P. vivax were 83.3% (95% CI: 58.6-96.4) and 97.2% (95% CI: 90.3-99.7).ConclusionsP. knowlesi was not detected by both microscopy and PCR. Giemsa stained microscopy can still be applied as primary method for malaria diagnosis and is considered as gold standard. As to the lower sensitivity of microscopy for vivax malaria, those with previous history of malaria and relapse cases should be diagnosed by RDT or PCR combined with microscopy. Inaccuracy of species diagnosis highlighted the requirement of training and refresher courses for microscopists. 展开更多
关键词 MALARIA plasmodium plasmodium knowlesi MICROSCOPY
下载PDF
Effects of Fungal Elicitors on Cell Growth and Artemisinin Accumulation in Hairy Root Cultures of Artemisia annua 被引量:13
15
作者 王红 叶和春 +2 位作者 李国凤 刘本叶 种康 《Acta Botanica Sinica》 CSCD 2000年第9期905-909,共5页
The artemisinin accumulation in the hairy root cultures of Artemisia annua L. was enhanced via a treatment of three fungal elicitors separately ( Verticillium dahliae Kleb., Rhizopus stolonifer (Ehrenb. ex ... The artemisinin accumulation in the hairy root cultures of Artemisia annua L. was enhanced via a treatment of three fungal elicitors separately ( Verticillium dahliae Kleb., Rhizopus stolonifer (Ehrenb. ex Fr.) Vuill and Colletotrichum dematium (Pers.) Grove). Among these three elicitors, V. dahliae had the highest inducing efficiency, but none of them manifests any noticeable effects on the cell growth of the hairy root cultures. The artemisinin content of the hairy root cultures treated with V. dahliae elicitor was 1.12 mg/g DW, which was 45% higher than the control (0.77 mg/g DW). The results showed that elicitation was dependent on the elicitor concentration, the incubation period and the physiological stage at which the hairy root cultures were treated. In addition, the authors found that for V. dahliae , the optimum concentration was 0.4 mg carbohydrate per millilitre medium, the strongest response of A. annua hairy root cultures to the elicitation was at the late exponential growth stage, and the highest artemisinin content of the hairy root cultures was on the 4th day post treatment. 展开更多
关键词 Artemisia annua hairy root cultures artemisinin fungal elicitor
下载PDF
Elicitation on Artemisinin Biosynthesis in Artemisia annua Hairy Roots by the Oligosaccharide Extract from the Endophytic Colletotrichum sp. B501 被引量:12
16
作者 王剑文 夏仲豪 谭仁祥 《Acta Botanica Sinica》 CSCD 2002年第10期1233-1238,共6页
The oligosaccharide elicitor from the mycelial wall of an endophytic Colletotrichum sp. B501 promoted the production of artemisinin in Artemisia annua L. hairy root culture. When hairy roots of 22-day-old cultures (la... The oligosaccharide elicitor from the mycelial wall of an endophytic Colletotrichum sp. B501 promoted the production of artemisinin in Artemisia annua L. hairy root culture. When hairy roots of 22-day-old cultures (later growth phase) were exposed to the elicitor (20 mg/L) for 4 d, the maximum content of artemisinin reached 1.15 mg/g, a 64.29% increment over the control. The electron X-ray microanalysis disclosed the rapid accumulation of Ca 2+ in the elicited cortical cells of hairy root. The electronic microscope observation revealed the high electron density area in vacuole of elicited cells. During the first day of elicitation the peroxidase activity of hairy roots was improved sharply. Some cellular morphological changes including cell shrinkage, condensation of cytoplasm and nuclear fragmentation, coincident with the appearance of DNA ladders, were observed after the third day of elicitation. It was suggested that the oligosaccharide elicitor triggered the programmed cell death, which may provide the substance or chemical signal for artemisinin biosynthesis. 展开更多
关键词 Artemisia annua Colletotrichum sp. B501 a fungal endophyte oligosaccharide elicitor artemisinin eliciting response
下载PDF
Antimalarial potential of kolaviron,a biflavonoid from Garcinia kola seeds,against Plasmodium berghei infection in Swiss albino mice 被引量:3
17
作者 Adaramoyc Oluwatosin Akinpelu Tolulope +4 位作者 Kosoko Ayokulchin Okoric Patricia Kehinde Aderemi Falade Catherine Ademowo Olusegun 《Asian Pacific Journal of Tropical Medicine》 SCIE CAS 2014年第2期97-104,共8页
Objective:To investigate the antimalarial potential of kolaviron(KV),a biflavonoid fraction from Garcinia kola seeds,against Plasmodium berghei(P.berghei)infection in Swiss albino mice.Methods:The study consists of se... Objective:To investigate the antimalarial potential of kolaviron(KV),a biflavonoid fraction from Garcinia kola seeds,against Plasmodium berghei(P.berghei)infection in Swiss albino mice.Methods:The study consists of seven groups of ten mice each.Groups I,II and III were normal mice that received com oil.KV1 and chloroquine(CQ),respectively.Groups IV,V,ⅥandⅦwere infected mice that received corn oil.CQ,KYI and KV2.respectively.CQ.KY1 and KV2were given at 10-,100-and 200-mg/kg daily,respectively for three consecutive days.Results:Administration of KV1 and KV2 significantly(P<0.05)suppressed P.berghei-infection in the mice by 85%and 90%.respectively,while CQ produced 87%suppression relative to untreated infected group after the fifth day of treatment.Also,KV2 significantly(P<0.05)increased the mean survival time of the infected mice by 175%.The biflavonoid prevented a drastic reduction in HCV from day4 of treatment,indicating its efficacy in ameliorating anaemia.Significant(P<0.05)oxidative stress assessed by the elevation of serum and hepatic malondialdehydewere observed in unlrealed P.berghei-infected mice.Specifically,senum and hepatic malondialdehyde levels increased by93%and 78%,resjiectively in the unlrealed infecled mice.Furlhennore,antioxidant indices,viz;superoxide dismutase.catalase,glutathione-s-transferasc.glualhione peroxidase and reduced gluathione decreased significantly(P<0.05)in the tissues of untreated P.berghei-infected mice.KV significantly(P<0.05)ameliorated the P.berghei-induced decrease in antioxidant status of the infected mice.Conclusions:This study shows that kolaviron,especially at 200 mg/kg,has high antimalarial activities in P.berghei-infected mice,in addition to its known antioxidant properties. 展开更多
关键词 ANTIMALARIA Antioxidant BIFLAVONOID KOLAVIRON plasmodium BERGHEI
下载PDF
Indicators of fatal outcome in severe Plasmodium falciparum malaria:a study in a tertiary-care hospital in Thailand 被引量:4
18
作者 Noppadon Tangpukdee Khin Myat Wai +5 位作者 Sant Muangnoicharoen Shigeyuki Kano Nanthaporn Phophak Janram Tiemprasert Srivicha Krudsood Polrat Wilairatana 《Asian Pacific Journal of Tropical Medicine》 SCIE CAS 2010年第11期855-859,共5页
Objective:To illustrate the clinical features and investigate the indicators associated with a fatal outcome in adult patients with severe Plasmodium falciparum malaria admitted to the Hospital for Tropical Diseases,B... Objective:To illustrate the clinical features and investigate the indicators associated with a fatal outcome in adult patients with severe Plasmodium falciparum malaria admitted to the Hospital for Tropical Diseases,Bangkok,Thailand.Methods:We studied 202 adult malaria patients admitted to the Intensive Care Unit.A total of 43 clinical variables were identified by univariate and logistic regression analyses,to eliminate confounding factors.Results:Regarding the statistical methods,only 6 variables-jaundice,cerebral malaria,metabolic acidosis,body mass index,initial respiratory rate,and white blood cell count-were significant indicators of death, with adjusted odds ratios(95%CI) of 15.2(2.1-32.3).4.3(2.3-12.6),3.3(2.3-5.7),2.4(1.9-3.5),2.2 (1.5-2.6),and 1.7(1.2-3.1),respectively.Conclusions:Our study found that jaundice,cerebral malaria,metabolic acidosis,body mass index,initial respiratory rate and white blood cell count were indicators of fatal outcome in severe Plasmodium falciparum malaria.Further studies on the fatal indicators in severe malaria need to be compared with data from different geographical areas,to construct practical measures to address potentially fatal indicators in different settings. 展开更多
关键词 plasmodium FALCIPARUM SEVERE malaria FATAL indicator TERTIARY CARE Thailand
下载PDF
Bioinformatics analysis for structure and function of CPR of Plasmodium falciparum 被引量:3
19
作者 Zhigang Fan Lingmin Zhang +4 位作者 Guogang Yan Qiang Wu Xiufeng Gan Saifeng Zhong Guifen Lin 《Asian Pacific Journal of Tropical Medicine》 SCIE CAS 2011年第2期85-87,共3页
Objective:To analyse the structure and function of NADPH-cytochrome p450 reductase(CYPOR or CPR) from Plasmodium falciparum(Pf),and to predict its’ drug target and vaccine target. Methods:The structure,function,drug ... Objective:To analyse the structure and function of NADPH-cytochrome p450 reductase(CYPOR or CPR) from Plasmodium falciparum(Pf),and to predict its’ drug target and vaccine target. Methods:The structure,function,drug target and vaccine target of CPR from Plasmodium falciparum were analyzed and predicted by bioinformatics methods.Results:PfCPR,which was older CPR,had close relationship with the CPR from other Plasmodium species,but it was distant from its hosts,such as Homo sapiens and Anopheles.PfCPR was located in the cellular nucleus of Plasmodium falciparum.335aa-352aa and 591aa - 608aa were inserted the interior side of the nuclear membrane,while 151aa-265aa was located in the nucleolus organizer regions.PfCPR had 40 function sites and 44 protein-protein binding sites in amino acid sequence.The teriary structure of laa-700aa was forcep-shaped with wings.15 segments of PfCPR had no homology with Homo sapien CPR and most were exposed on the surface of the protein.These segments had 25 protein-protein binding sites.While 13 other segments all possessed function sites. Conclusions:The evolution or genesis of Plasmodium falciparum is earlier than those of Homo sapiens.PfCPR is a possible resistance site of antimalarial drug and may involve immune evasion, which is associated with parasite of sporozoite in hepatocytes.PfCPR is unsuitable as vaccine target,but it has at least 13 ideal drug targets. 展开更多
关键词 plasmodium FALCIPARUM NADPH-cytochrome p450 reductase Origin Immune EVASION Drug TARGET Vaccine TARGET
下载PDF
Schistosoma haematobium and Plasmodium falciparum coinfection with protection against Plasmodium falciparum malaria in Nigerian children 被引量:2
20
作者 Nmorsi OPG Isaac C +2 位作者 Ukwandu NCD Ekundayo AO Ekozien MI 《Asian Pacific Journal of Tropical Medicine》 SCIE CAS 2009年第2期16-20,共5页
Objective:Malaria remains the single leading killer of children in sub - Sahara Africa and Schistosomiasis is considered to be second to malaria in global importance.Co - infection of malaria and urinary schistosomias... Objective:Malaria remains the single leading killer of children in sub - Sahara Africa and Schistosomiasis is considered to be second to malaria in global importance.Co - infection of malaria and urinary schistosomiasis has been reported to exacerbate disease morbidity such as anaemia.In different part of the globe,the co - infection between malaria and schistosomiasis provides some protections on the infected persons.The protective effect of this co - infection elucidated immunologically using cytokines is lacking in our locality.Methods:Urine and blood samples obtained from the 160 volunteers were subjected to standard parasitological techniques for diagnosis of urinary schistosomiasis and malaria respectively.Blood samples collected from these volunteers comprising 80 children with schistosomiasis and malaria and the 80 children who had malaria only were subjected to cytokines concentration determination using commercial standard enzyme linked immunosorbent assay kits(Abeam,UK).Results:Eighty participants with co - infection had a mean malarial parasitaemia of 662±201.1μL while the 80 participants with only P.falciparum malaria had a mean malarial parasiteamia of 5943±3270.7μL.Also the volunteers had mean haemoglobin of 11.2 g/dL for co - infected individuals and 5.7 g/dL for participants with single infection of malaria.The serum cytokine levels of the children with S. haematobium and P.falciparum and only P.falciparum infection are as follows;interleukin - 4(16.6 pg/ mL versus 5.2 pg/mL),IL - 5(501.3 pg/mL versus 357.5 pg/mL);IL -8(2 550 pg/mL versus 309 pg/mL),IL - 10(273 pg/mL versus 290 pg/mL),TNF -α(25 pg/mL versus 290 pg/mL) and IFN -γ(21.9 pg/mL versus 2.5 pg/mL).The TNF -α/IL - 10 ratio is 7 for the children with co - infection while those with only P.falciparum malaria infection had a TNF -α/IL - 10 ratio of 0.9.Conclusion:We conclude that the elevated IL - 4,IL - 5,IL - 8 and IFN -γconcentration induced by schistosomiasis altered the Th1/Th 2 profile and protected the children against the morbidity and severity of malaria attack among the children with co - infection. 展开更多
关键词 SCHISTOSOMA haematobium plasmodium FALCIPARUM MALARIA
下载PDF
上一页 1 2 157 下一页 到第
使用帮助 返回顶部