India bears the largest Plasmodium (P.) vivax (Pv) malaria burden and contributes 48%of Pv cases globally[1]. The efforts of government and private bodies to control malaria have successfully reduced the number of Pla...India bears the largest Plasmodium (P.) vivax (Pv) malaria burden and contributes 48%of Pv cases globally[1]. The efforts of government and private bodies to control malaria have successfully reduced the number of Plasmodium falciparum (Pf) malaria cases in several countries, including India.展开更多
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
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
Objective:To compare the applicability of the SYBK Grcen-Ⅰ assay with the standard schizont maturalion assay,for determination of sensitivity of Plasmodium vivax(P.vivax) to chloroquine and a new antifolale WR 99210....Objective:To compare the applicability of the SYBK Grcen-Ⅰ assay with the standard schizont maturalion assay,for determination of sensitivity of Plasmodium vivax(P.vivax) to chloroquine and a new antifolale WR 99210.Methods:The study was conducted at Mae Tao Clinic for migrant workers,Tak Province during April 2009 to July 2010.A total of 64 blood samples(1 mL blood collected into sodium heparinized plastic tube) were collected from patients with monoinfection with P.vivax malaria prior to treatment with standard regimen of a 3-day chloroquine. In vitro sensitivity of P.vivax isolates was evaluated by schizont maturation inhibition and SYBR Green-Ⅰ assays.Results:A total of 30 out of 64 blood samples collected from patients with P.vivax malaria were successfully analyzed using both the microscopic schizont maturation inhibition and SYBR Green-I assays.The failure rates of the schizont maturation inhibition assay(50%) and the SYBR Green-I assay(54%) were similar(P=0.51).The median IC_(10)s,IC_(50)s and IC_(90)s of both chloroquine and WR99210 were not significantly different from the clinical isolates of P.vivax tested.Based on the cut-off of 100 nM,the prevalences of chloroquine resistance determined by schizont maturation inhibition and SYBR Green-I assays were 19 and 11 isolates,respectively.The strength of agreement between the two methods was very poor for both chloroquine and WR992I0.Conclusions:On the basis of this condition and its superior sensitivity,the microscopic method appears better than the SYUK Green-I Green assay for assessing in vitro sensitivity of fresh P.vivax isolates to antimalarial drugs.展开更多
Complicated malaria is usually due to Plasmodium falciparum.Nevertheless,Plasmodium vivax is infrequently related with life-threatening complications.Few cases have been reported of severe Plasmodium vivax infection,a...Complicated malaria is usually due to Plasmodium falciparum.Nevertheless,Plasmodium vivax is infrequently related with life-threatening complications.Few cases have been reported of severe Plasmodium vivax infection,and most of them from Southeast Asia and India.We report the first case of cerebral malaria due to Plasmodium vivax in Latin America,complicated with sagittal sinus thrombosis and confirmed by a molecular method.展开更多
Objective:To investigate the genetic polymorphism of Plasmodium vivax(P.vivax) PvCSP and PvMSP1 genes from field isolates at four endemic regions(North,East,West and South) of Thailand.Methods:The 152 P.vivax injected...Objective:To investigate the genetic polymorphism of Plasmodium vivax(P.vivax) PvCSP and PvMSP1 genes from field isolates at four endemic regions(North,East,West and South) of Thailand.Methods:The 152 P.vivax injected cases from dried blood spots were DMA extracted and confirmed by species-specific primer sets using multiplex PCR method.PvMSPI fragments F2 and F3:PvCSP were gcnotvped using RFLP-PCR method.Resuits:Totally amplified DNA which was multiple genotypes for PvMSP1 F2 and PvMSP1 F3 were 12.50%and 8.55%.respectively while PvCSP was 3.95%.The overall frequency of multiple genotypes was 25%.There were 12 allele tvpes of PvMSP1 F2 using AluI enzyme digestion and 8 size variations were found in P\MSP1 F3.The isolates from western region was highly genetic diverse when compare among all isolates.The predominant variant type of PvCSP gene was \ K2I0 type.Conclusions:The niulliple genotypes are common found in Thailand and it might hide the real genotype.PvCSP does not have extensive genetic diversity in this study.However.PvMSPI marker due to multiple genotypes is difficult In be analyzed.The multiple genotypes findings might stem from population migration and vector species findings.展开更多
Objective:To determine the range and incidence of complications associated with Plasmodium vivax[P.vivax) malaria.Methods:A retrospective analysis was performed of all patients of P.vivax malaria admitted in kasturba ...Objective:To determine the range and incidence of complications associated with Plasmodium vivax[P.vivax) malaria.Methods:A retrospective analysis was performed of all patients of P.vivax malaria admitted in kasturba Medical College.Manipal between January and December,2010.Patients with mixed malarial infection were excluded by appropriate tests. Clinical presentation and laboratory parameters were studied.Results:Medical records of 213 individuals who satisfied the inclusion criteria were reviewed.Anaemia was seen in 65 (30.5%),leucopenia in 38(17.8%]and thrombocytopenia in 184(86.4%l patients.Aspartate and alanine aminotransferases were elevated in 86(40.4%).and 89(41.9%) patients respectively. Hypoalbuminemia was observed in 157(73.6%) cases.Elevated serum creatinine was noted in in 59(27.5%) patients.Creatine kinase was elevated in 30 nut of 59 patients(50.8%).Overall.107 (50.2%) patients fulfilled WHO criteria for sever=e malaria.None of the patients succumbed to the disease.Conclusion:P.vivax malaria is a potentially severe disease,and the term ’ benign" tertian malaria is a misnomer.Despite significant morbidity,with timely and appropriate treatment P.rirax malaria has an excellent outcome.展开更多
Objective:To identify cases of severe Plasmodium vivax(P.vivax) mono-infections among adults.Methods:In this retrospective study,30 adult patients admitted to medical wards of a tertiary hospital in a malaria endemic ...Objective:To identify cases of severe Plasmodium vivax(P.vivax) mono-infections among adults.Methods:In this retrospective study,30 adult patients admitted to medical wards of a tertiary hospital in a malaria endemic urban area from March 2010 to April 2010 were included. The diagnosis of P.vivax malaria was established by peripheral blood film(PBF) examination, and severe malaria was categorized as per World Health Organization guidelines.Results: Complications observed were thrombocytopenia in 28(93.3%),hepatic dysfunction and jaundice in 13(433%),renal dysfunction in 8(26.7%),severe anaemia in 3(10.0%),cerebral malaria in 2 (6.7%),and acute respiratory distress syndrome(ARDS) in 1(3.3%) of 30 patients.Conclusions:P. vivax malaria with severe complications is common in the investigated area,and an intensive and large-scale study of the disease is necessary.展开更多
Objective:To evaluate microscopy,OptiMAL<sup>?</sup> and multiplex PCR for the identification of Plasmodium falciparum(P.falciparum) and Plasmodium vivax(P.vivax) from the field isolates of Bikaner,Raj...Objective:To evaluate microscopy,OptiMAL<sup>?</sup> and multiplex PCR for the identification of Plasmodium falciparum(P.falciparum) and Plasmodium vivax(P.vivax) from the field isolates of Bikaner,Rajasthan(Northwest India).Methods:In this study,a multiplex PCR(P.falciparum and P.vivax) was further developed with the incorporation of Plasmodium malariae(P.malariae) specific primer and also a positive control.The performance of microscopy,plasmodium lactate dehydrogenase(pLDH) based malaria rapid diagnostic test OptiMAL<sup>?</sup> and 18S rRNA gene based multiplex PCR for the diagnosis of P.falciparum and P.vivax was compared.Results:The three species multiplex PCR if.falciparum,P.vivax and P.malariae) with an inbuilt positive control was developed and evaluated.In comparison with multiplex PCR,which showed the sensitivity and specificity of 99.36%(95%CI,98.11%-100.00%) and 100.00%(95%CI,100.00%-100.00%),the sensitivity and specificity of microscopy was 90.44%(95%CI,88.849-95.04%) and 99.22%(95% CI,97.71%-100.00%),and OptiMAL<sup>?</sup> was 93.58%(95%CI,89.75%-97.42%) and 97.69%(95%CI, 95.10%-100.00%).The efficiencies were 99.65%,95.10%and 95.45%for multiplex PCK.microscopy and OptiMAL<sup>?</sup>.respectively.Conclusions:Our results raise concerns over the overall sensitivities of microscopy and OptiMAL<sup>?</sup>,when compared to the multiplex PCR and thus stress the need for new molecular interventions in the accurate detection of the malarial parasites.This further highlights the fact that further developments are needed to improve the performance of rapid diagnostic tests at field level.展开更多
In tropical countries like India,malaria has been one of the most common parasitic illnesses leading to frequent hospitalization and causing major economic burden among the masses. Although Plasmodium vivax infection ...In tropical countries like India,malaria has been one of the most common parasitic illnesses leading to frequent hospitalization and causing major economic burden among the masses. Although Plasmodium vivax infection is considered to be benign,in contrast to Plasmodium, falciparum infection which is notorious for its severe splenic complications can occur frequently. Splenomegaly tends not to receive special attention,as it is not usually accompanied by any symptoms and can be gradually resolved via standard antimalarial therapy.Splenic infarction, although rarely attributable to malaria in an endemic region with high parasitemia,can be a rare presentation of this disease entity.展开更多
Objective:To do mapping and modeling of conformational B cell epitope regions of highly conserved and protective regions of three merozoitecandidate vaccine proteins of Plasmodium vivax(P.vivax),ie.merozoite purface p...Objective:To do mapping and modeling of conformational B cell epitope regions of highly conserved and protective regions of three merozoitecandidate vaccine proteins of Plasmodium vivax(P.vivax),ie.merozoite purface protein-1(PvMSP-1),apical membrane antigen-1 domainⅡ(PvAMA1-DⅡ)and regionⅡof the Duffy binding protein(PvDBPⅡ).and to analyze the immunogenie properties of these predicted epitopes.Methods:3-D structures of amino acid haplotypes from Sri Lanka(available in GeneBank)of PvMSP-1_(19)(n=27),PvAMA1-DⅡ(n=21)and PvDBPⅡ(n=33)were modeled.SEPPA,selected as the best online server was used for conformational epitope predictions,while prediction and moodeling of protein structuve and properties related to immunogenicity was carried out with Geno3D server.SCRATCH Protein Server,NetSurfP Server and standaloneroftware,Genious 5.4.4.Results:SEPPA revealed that regions of predicted conformational epitopes formed 4 clusters in PvMSP-I_(19),and 3 clusters each in PvAMA1-DⅡand PvDBPⅡ,all of which displayed a high degree of hydrophilicity,contained solveut exposed residues,displayed high probability of antigenicity and showed positive antigenic propensity values,that indicated high degree of immunogenicity.Conclusions:Findings of this study revealed and confirmed that different parts of the sequences of each of the conserved regions of the three selected potential vaccine candidate antigens of P.vivax are important with regard to conformational epitope prediction that warrants further laboratory experimental invertigations in in vivo animal models.展开更多
A cloned DNA fragment specific for Plasmodium vivax was cleaved from theplasmid pVA1 and ligated into phage M13mp18.The nucleotides of the insert were se-quenced by the dideoxy-chain termination procedure.The fragment...A cloned DNA fragment specific for Plasmodium vivax was cleaved from theplasmid pVA1 and ligated into phage M13mp18.The nucleotides of the insert were se-quenced by the dideoxy-chain termination procedure.The fragment was composed of 261base pairs and 3 Hinf Ⅰ sites but no tandem repeat sequences.Computer retrieval andanalysis show that the nucleotide sequence of the cloned DNA fragment is unique,forthere has not been any significant homologue with that of other Plasmodium genes pub-lished as yet.展开更多
Hemophagocytic lymphohistiocytosis syndrome (HPS) is a potentially fatal hyperinflammatory response characterized by a generalized histiocytic proliferation with marked hemophagocytosis in bone marrow [1]. Hemophagocy...Hemophagocytic lymphohistiocytosis syndrome (HPS) is a potentially fatal hyperinflammatory response characterized by a generalized histiocytic proliferation with marked hemophagocytosis in bone marrow [1]. Hemophagocytic syndrome has been associated with genetic mutations, autoimmune diseases, hematological malignancies or infections [2,3]. According to the data from Centre for Disease Control and prevention (CDC) Plasmodium falciparum has been associated with HPS but not the Plasmodium vivax [4-7]. We report a case of hemophagocytic syndrome as a complication of Plasmodium vivax malaria which is a rare presentation according to the data. This patient presented with high grade fever with chills (P. vivax positive), fever however did not respond to anti-malarials. The patient continued to have high grade fever with altered sensorium and deranged liver function with pancytopenia. Since she fulfilled the criteria of (HPS), patient was put on injectable steroids and responded dramatically. Hemophagocytic syndrome is a potentially fatal syndrome and therefore high index suspicion and early treatment is the key to reduce the mortatlity.展开更多
Background:In most of the Americas,the recommended treatment to prevent relapse of Plasmodium vivax malaria is primaquine at a total dose of 3.5 mg per kilogram of body weight,despite evidence of only moderate efficac...Background:In most of the Americas,the recommended treatment to prevent relapse of Plasmodium vivax malaria is primaquine at a total dose of 3.5 mg per kilogram of body weight,despite evidence of only moderate efficacy.Methods:In this trial conducted in Brazil,we evaluated three primaquine regimens to prevent relapse of P.vivax malaria in children at least 5 years of age and in adults with microscopy-confirmed P.vivax monoinfection.All the patients received directly observed chloroquine for 3 days(total dose,25 mg per kilogram).Group 1 received a total primaquine dose of 3.5 mg per kilogram(0.5 mg per kilogram per day)over 7 days with unobserved administration;group 2 received the same regimen as group 1 but with observed administration;and group 3 received a total primaquine dose of 7.0 mg per kilogram over 14 days(also 0.5 mg per kilogram per day)with observed administration.We monitored the patients for 168 days.展开更多
Objective:To determine the involvement and the modulatory effects of IL-33 during Plasmodium berghei ANKA(PbA)infection.Methods:PbA infection in male ICR mice was utilized as a model of malaria.Systemically circulatin...Objective:To determine the involvement and the modulatory effects of IL-33 during Plasmodium berghei ANKA(PbA)infection.Methods:PbA infection in male ICR mice was utilized as a model of malaria.Systemically circulating IL-33 levels were determined in blood plasma by enzyme-linked immunosorbent assay(ELISA).After 24 hours post-inoculation of PbA,recombinant IL-33 and ST2,and antibodies against IL-33 and IgG treatments were administered daily for 3 days.Tissue expression and localization of IL-33 were assessed in organs generally affected by malaria via immunohistochemistry.Moreover,histopathological examination was performed to assess the effects of the treatments.Results:The levels of systemic IL-33 were elevated at the critical phase of PbA infection.Likewise,immunohistochemical analysis revealed a significant upregulation of IL-33 expression at the critical phase in the brain,lungs,and spleen of PbA-infected mice as compared to healthy controls.Treatment with IL-33 protected against experimental cerebral malaria development and reduced pathological features in the brain and lungs of the PbA-infected mice.Conclusions:A potential critical role and involvement of IL-33 in PbA infection may hint at the resolution of immunopathological sequelae associated with malaria.展开更多
Objective:To determine the genetic diversity,natural selection and mutations in Plasmodium(P.)knowlesi drug resistant molecular markers Kelch 13 and dhps gene in clinical samples of Malaysia.Methods:P.knowlesi full-le...Objective:To determine the genetic diversity,natural selection and mutations in Plasmodium(P.)knowlesi drug resistant molecular markers Kelch 13 and dhps gene in clinical samples of Malaysia.Methods:P.knowlesi full-length gene sequences Kelch 13 gene(PkK13)from 40 samples and dhps gene from 30 samples originating from Malaysian Borneo were retrieved from public databases.Genetic diversity,natural selection,and phylogenetic analysis of gene sequences were analysed using DNAsp v5.10 and MEGA v5.2.Results:Seventy-two single nucleotide polymorphic sites(SNPs)across the full-length PkK13 gene(63 synonymous substitutions and 9 non-synonymous substitutions)with nucleotide diversity ofπ~0.005 was observed.Analysis of the full-length Pkdhps gene revealed 73 SNPs andπ~0.006(44 synonymous substitutions and 29 non-synonymous substitutions).A high number of haplotypes(PkK13;H=37 and Pkdhps;H=29)with haplotype diversity of Hd~0.99 were found in both genes,indicating population expansion.Nine mutant alleles were identified in PkK13 amino acid alignment of which,7(Asp3Glu,Lys50Gln,Lys53Glu,Ser123Thr,Ser127Pro,Ser149Thr and Ala169Thr)were within the Plasmodium specific domain,2(Val372Ile and Lys424Asn)were in the BTB/POZ domain and no mutation was observed within the kelch propeller domain.The 29 non-synonymous mutations in the Pkdhps gene were novel and only presented in exon 1 and 2.Conclusions:Monitoring the mutations from clinical samples collected from all states of Malaysia along with clinical efficacy studies will be necessary to determine the drug resistance in P.knowlesi.展开更多
文摘India bears the largest Plasmodium (P.) vivax (Pv) malaria burden and contributes 48%of Pv cases globally[1]. The efforts of government and private bodies to control malaria have successfully reduced the number of Plasmodium falciparum (Pf) malaria cases in several countries, including India.
基金This study was supported by the Ministry of Higher Education,Malaysia(FRGS0322-SG-1/2013)Universiti Malaysia Sabah(GUG0521-2/2020).
文摘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.
文摘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.
基金Supported by the Commission on Higher EducationMinistry of Education of Thailand and Thailand National Research University(NRU)
文摘Objective:To compare the applicability of the SYBK Grcen-Ⅰ assay with the standard schizont maturalion assay,for determination of sensitivity of Plasmodium vivax(P.vivax) to chloroquine and a new antifolale WR 99210.Methods:The study was conducted at Mae Tao Clinic for migrant workers,Tak Province during April 2009 to July 2010.A total of 64 blood samples(1 mL blood collected into sodium heparinized plastic tube) were collected from patients with monoinfection with P.vivax malaria prior to treatment with standard regimen of a 3-day chloroquine. In vitro sensitivity of P.vivax isolates was evaluated by schizont maturation inhibition and SYBR Green-Ⅰ assays.Results:A total of 30 out of 64 blood samples collected from patients with P.vivax malaria were successfully analyzed using both the microscopic schizont maturation inhibition and SYBR Green-I assays.The failure rates of the schizont maturation inhibition assay(50%) and the SYBR Green-I assay(54%) were similar(P=0.51).The median IC_(10)s,IC_(50)s and IC_(90)s of both chloroquine and WR99210 were not significantly different from the clinical isolates of P.vivax tested.Based on the cut-off of 100 nM,the prevalences of chloroquine resistance determined by schizont maturation inhibition and SYBR Green-I assays were 19 and 11 isolates,respectively.The strength of agreement between the two methods was very poor for both chloroquine and WR992I0.Conclusions:On the basis of this condition and its superior sensitivity,the microscopic method appears better than the SYUK Green-I Green assay for assessing in vitro sensitivity of fresh P.vivax isolates to antimalarial drugs.
文摘Complicated malaria is usually due to Plasmodium falciparum.Nevertheless,Plasmodium vivax is infrequently related with life-threatening complications.Few cases have been reported of severe Plasmodium vivax infection,and most of them from Southeast Asia and India.We report the first case of cerebral malaria due to Plasmodium vivax in Latin America,complicated with sagittal sinus thrombosis and confirmed by a molecular method.
基金supported by "Strategic Scholarships Fellowships Fromtier Research Network"from the Commission Higher Education(Thailand) (Grant No.CHE-PhD-SW-INV-20060169)also parially supported by the China Medical Board,Faculty of Public Health,Mahidol University,Bangkok,Thailand
文摘Objective:To investigate the genetic polymorphism of Plasmodium vivax(P.vivax) PvCSP and PvMSP1 genes from field isolates at four endemic regions(North,East,West and South) of Thailand.Methods:The 152 P.vivax injected cases from dried blood spots were DMA extracted and confirmed by species-specific primer sets using multiplex PCR method.PvMSPI fragments F2 and F3:PvCSP were gcnotvped using RFLP-PCR method.Resuits:Totally amplified DNA which was multiple genotypes for PvMSP1 F2 and PvMSP1 F3 were 12.50%and 8.55%.respectively while PvCSP was 3.95%.The overall frequency of multiple genotypes was 25%.There were 12 allele tvpes of PvMSP1 F2 using AluI enzyme digestion and 8 size variations were found in P\MSP1 F3.The isolates from western region was highly genetic diverse when compare among all isolates.The predominant variant type of PvCSP gene was \ K2I0 type.Conclusions:The niulliple genotypes are common found in Thailand and it might hide the real genotype.PvCSP does not have extensive genetic diversity in this study.However.PvMSPI marker due to multiple genotypes is difficult In be analyzed.The multiple genotypes findings might stem from population migration and vector species findings.
文摘Objective:To determine the range and incidence of complications associated with Plasmodium vivax[P.vivax) malaria.Methods:A retrospective analysis was performed of all patients of P.vivax malaria admitted in kasturba Medical College.Manipal between January and December,2010.Patients with mixed malarial infection were excluded by appropriate tests. Clinical presentation and laboratory parameters were studied.Results:Medical records of 213 individuals who satisfied the inclusion criteria were reviewed.Anaemia was seen in 65 (30.5%),leucopenia in 38(17.8%]and thrombocytopenia in 184(86.4%l patients.Aspartate and alanine aminotransferases were elevated in 86(40.4%).and 89(41.9%) patients respectively. Hypoalbuminemia was observed in 157(73.6%) cases.Elevated serum creatinine was noted in in 59(27.5%) patients.Creatine kinase was elevated in 30 nut of 59 patients(50.8%).Overall.107 (50.2%) patients fulfilled WHO criteria for sever=e malaria.None of the patients succumbed to the disease.Conclusion:P.vivax malaria is a potentially severe disease,and the term ’ benign" tertian malaria is a misnomer.Despite significant morbidity,with timely and appropriate treatment P.rirax malaria has an excellent outcome.
文摘Objective:To identify cases of severe Plasmodium vivax(P.vivax) mono-infections among adults.Methods:In this retrospective study,30 adult patients admitted to medical wards of a tertiary hospital in a malaria endemic urban area from March 2010 to April 2010 were included. The diagnosis of P.vivax malaria was established by peripheral blood film(PBF) examination, and severe malaria was categorized as per World Health Organization guidelines.Results: Complications observed were thrombocytopenia in 28(93.3%),hepatic dysfunction and jaundice in 13(433%),renal dysfunction in 8(26.7%),severe anaemia in 3(10.0%),cerebral malaria in 2 (6.7%),and acute respiratory distress syndrome(ARDS) in 1(3.3%) of 30 patients.Conclusions:P. vivax malaria with severe complications is common in the investigated area,and an intensive and large-scale study of the disease is necessary.
文摘Objective:To evaluate microscopy,OptiMAL<sup>?</sup> and multiplex PCR for the identification of Plasmodium falciparum(P.falciparum) and Plasmodium vivax(P.vivax) from the field isolates of Bikaner,Rajasthan(Northwest India).Methods:In this study,a multiplex PCR(P.falciparum and P.vivax) was further developed with the incorporation of Plasmodium malariae(P.malariae) specific primer and also a positive control.The performance of microscopy,plasmodium lactate dehydrogenase(pLDH) based malaria rapid diagnostic test OptiMAL<sup>?</sup> and 18S rRNA gene based multiplex PCR for the diagnosis of P.falciparum and P.vivax was compared.Results:The three species multiplex PCR if.falciparum,P.vivax and P.malariae) with an inbuilt positive control was developed and evaluated.In comparison with multiplex PCR,which showed the sensitivity and specificity of 99.36%(95%CI,98.11%-100.00%) and 100.00%(95%CI,100.00%-100.00%),the sensitivity and specificity of microscopy was 90.44%(95%CI,88.849-95.04%) and 99.22%(95% CI,97.71%-100.00%),and OptiMAL<sup>?</sup> was 93.58%(95%CI,89.75%-97.42%) and 97.69%(95%CI, 95.10%-100.00%).The efficiencies were 99.65%,95.10%and 95.45%for multiplex PCK.microscopy and OptiMAL<sup>?</sup>.respectively.Conclusions:Our results raise concerns over the overall sensitivities of microscopy and OptiMAL<sup>?</sup>,when compared to the multiplex PCR and thus stress the need for new molecular interventions in the accurate detection of the malarial parasites.This further highlights the fact that further developments are needed to improve the performance of rapid diagnostic tests at field level.
文摘In tropical countries like India,malaria has been one of the most common parasitic illnesses leading to frequent hospitalization and causing major economic burden among the masses. Although Plasmodium vivax infection is considered to be benign,in contrast to Plasmodium, falciparum infection which is notorious for its severe splenic complications can occur frequently. Splenomegaly tends not to receive special attention,as it is not usually accompanied by any symptoms and can be gradually resolved via standard antimalarial therapy.Splenic infarction, although rarely attributable to malaria in an endemic region with high parasitemia,can be a rare presentation of this disease entity.
文摘Objective:To do mapping and modeling of conformational B cell epitope regions of highly conserved and protective regions of three merozoitecandidate vaccine proteins of Plasmodium vivax(P.vivax),ie.merozoite purface protein-1(PvMSP-1),apical membrane antigen-1 domainⅡ(PvAMA1-DⅡ)and regionⅡof the Duffy binding protein(PvDBPⅡ).and to analyze the immunogenie properties of these predicted epitopes.Methods:3-D structures of amino acid haplotypes from Sri Lanka(available in GeneBank)of PvMSP-1_(19)(n=27),PvAMA1-DⅡ(n=21)and PvDBPⅡ(n=33)were modeled.SEPPA,selected as the best online server was used for conformational epitope predictions,while prediction and moodeling of protein structuve and properties related to immunogenicity was carried out with Geno3D server.SCRATCH Protein Server,NetSurfP Server and standaloneroftware,Genious 5.4.4.Results:SEPPA revealed that regions of predicted conformational epitopes formed 4 clusters in PvMSP-I_(19),and 3 clusters each in PvAMA1-DⅡand PvDBPⅡ,all of which displayed a high degree of hydrophilicity,contained solveut exposed residues,displayed high probability of antigenicity and showed positive antigenic propensity values,that indicated high degree of immunogenicity.Conclusions:Findings of this study revealed and confirmed that different parts of the sequences of each of the conserved regions of the three selected potential vaccine candidate antigens of P.vivax are important with regard to conformational epitope prediction that warrants further laboratory experimental invertigations in in vivo animal models.
文摘A cloned DNA fragment specific for Plasmodium vivax was cleaved from theplasmid pVA1 and ligated into phage M13mp18.The nucleotides of the insert were se-quenced by the dideoxy-chain termination procedure.The fragment was composed of 261base pairs and 3 Hinf Ⅰ sites but no tandem repeat sequences.Computer retrieval andanalysis show that the nucleotide sequence of the cloned DNA fragment is unique,forthere has not been any significant homologue with that of other Plasmodium genes pub-lished as yet.
文摘Hemophagocytic lymphohistiocytosis syndrome (HPS) is a potentially fatal hyperinflammatory response characterized by a generalized histiocytic proliferation with marked hemophagocytosis in bone marrow [1]. Hemophagocytic syndrome has been associated with genetic mutations, autoimmune diseases, hematological malignancies or infections [2,3]. According to the data from Centre for Disease Control and prevention (CDC) Plasmodium falciparum has been associated with HPS but not the Plasmodium vivax [4-7]. We report a case of hemophagocytic syndrome as a complication of Plasmodium vivax malaria which is a rare presentation according to the data. This patient presented with high grade fever with chills (P. vivax positive), fever however did not respond to anti-malarials. The patient continued to have high grade fever with altered sensorium and deranged liver function with pancytopenia. Since she fulfilled the criteria of (HPS), patient was put on injectable steroids and responded dramatically. Hemophagocytic syndrome is a potentially fatal syndrome and therefore high index suspicion and early treatment is the key to reduce the mortatlity.
文摘Background:In most of the Americas,the recommended treatment to prevent relapse of Plasmodium vivax malaria is primaquine at a total dose of 3.5 mg per kilogram of body weight,despite evidence of only moderate efficacy.Methods:In this trial conducted in Brazil,we evaluated three primaquine regimens to prevent relapse of P.vivax malaria in children at least 5 years of age and in adults with microscopy-confirmed P.vivax monoinfection.All the patients received directly observed chloroquine for 3 days(total dose,25 mg per kilogram).Group 1 received a total primaquine dose of 3.5 mg per kilogram(0.5 mg per kilogram per day)over 7 days with unobserved administration;group 2 received the same regimen as group 1 but with observed administration;and group 3 received a total primaquine dose of 7.0 mg per kilogram over 14 days(also 0.5 mg per kilogram per day)with observed administration.We monitored the patients for 168 days.
基金supported by the Fundamental Research Grant Scheme(FRGS)from the Malaysia Ministry of Higher Education(FRGS/1/2016/SKK10/UPM/02/1).
文摘Objective:To determine the involvement and the modulatory effects of IL-33 during Plasmodium berghei ANKA(PbA)infection.Methods:PbA infection in male ICR mice was utilized as a model of malaria.Systemically circulating IL-33 levels were determined in blood plasma by enzyme-linked immunosorbent assay(ELISA).After 24 hours post-inoculation of PbA,recombinant IL-33 and ST2,and antibodies against IL-33 and IgG treatments were administered daily for 3 days.Tissue expression and localization of IL-33 were assessed in organs generally affected by malaria via immunohistochemistry.Moreover,histopathological examination was performed to assess the effects of the treatments.Results:The levels of systemic IL-33 were elevated at the critical phase of PbA infection.Likewise,immunohistochemical analysis revealed a significant upregulation of IL-33 expression at the critical phase in the brain,lungs,and spleen of PbA-infected mice as compared to healthy controls.Treatment with IL-33 protected against experimental cerebral malaria development and reduced pathological features in the brain and lungs of the PbA-infected mice.Conclusions:A potential critical role and involvement of IL-33 in PbA infection may hint at the resolution of immunopathological sequelae associated with malaria.
基金supported by the institutional funding committee of Najran University,Najran,Saudi Arabia(Project code:NU/IFC/ENT/01/007).
文摘Objective:To determine the genetic diversity,natural selection and mutations in Plasmodium(P.)knowlesi drug resistant molecular markers Kelch 13 and dhps gene in clinical samples of Malaysia.Methods:P.knowlesi full-length gene sequences Kelch 13 gene(PkK13)from 40 samples and dhps gene from 30 samples originating from Malaysian Borneo were retrieved from public databases.Genetic diversity,natural selection,and phylogenetic analysis of gene sequences were analysed using DNAsp v5.10 and MEGA v5.2.Results:Seventy-two single nucleotide polymorphic sites(SNPs)across the full-length PkK13 gene(63 synonymous substitutions and 9 non-synonymous substitutions)with nucleotide diversity ofπ~0.005 was observed.Analysis of the full-length Pkdhps gene revealed 73 SNPs andπ~0.006(44 synonymous substitutions and 29 non-synonymous substitutions).A high number of haplotypes(PkK13;H=37 and Pkdhps;H=29)with haplotype diversity of Hd~0.99 were found in both genes,indicating population expansion.Nine mutant alleles were identified in PkK13 amino acid alignment of which,7(Asp3Glu,Lys50Gln,Lys53Glu,Ser123Thr,Ser127Pro,Ser149Thr and Ala169Thr)were within the Plasmodium specific domain,2(Val372Ile and Lys424Asn)were in the BTB/POZ domain and no mutation was observed within the kelch propeller domain.The 29 non-synonymous mutations in the Pkdhps gene were novel and only presented in exon 1 and 2.Conclusions:Monitoring the mutations from clinical samples collected from all states of Malaysia along with clinical efficacy studies will be necessary to determine the drug resistance in P.knowlesi.