Immune Responses to Defined Plasmodium Falciparum Antigens and Disease Susceptibility in Two Subpopulations of Northern India

The aim of this study was to investigate the prevalence of naturally acquired immune response to malaria in individuals of different age groups belonging to areas of northern India, Loni PHC (LN) and Dhaulana PHC (SD) of district Ghaziabad. Plasmodium falciparum-infected erythrocyte lysate and six synthetic peptides from different stages of P. falciparum (CSP, MSP1, AMA1, RAP1, EBA175 and PfG27) were used to determine both humoral and cellular immune responses. Plasma of individual subject was also analyzed for IL-4, IL-10, IFN-γ and TNF-α level. We observed an age-wise increasing trend of immunity in these two populations. There was a significant association between the number of antibody responders and recognition of stage-specific epitopes by antibodies. Peripheral blood mononuclear cells of more than 75% of individuals proliferated in response to stimulation by all the antigens in LN area. IL-4 and IL-10 responses were significantly higher in individuals of LN Area; whereas IFN-g and   TNF-a responses were higher in individuals of SD Area. It was also noticed that the frequency of responders to stage-specific antigens was higher in individuals from the LN area where the frequency of malaria was lower. The naturally acquired immune responses to P. falciparum antigens reflected the reduced risk of malaria in the study groups. The results demonstrated immunogenicity of the epitopes to P. falciparum in population of this endemic zone

Isolation and Purification of C-phycocyanin From Nostoc Muscorum (Cyanophyceae and Cyanobacteria) Exhibits Antimalarial Activity in Vitro

The phycobilin pigments are intensively fluorescent and water soluble. They are categorized into three types, such as pigments containing high, intermediate and low energies are phycoerythrins (phycoerythrocyanins), phycocyanins and allophycocyanins, respectively. Besides light harvesting, the phycobiliproteins have shown industrial and biomedical importance. Among them, C-phycocyanin (C-PC) has been considered to be the most preferred one. The present study was undertaken to evaluate the antimalarial activity of C-PC isolated from a nitrogen-fixing cyanobacterium and Nostoc muscorum. C-PC was extracted and purified by acetone extraction and ammonium sulfate precipitation and dialysis followed by amicon filtration. It was isolated as a~124 kDa water soluble protein molecule. It showed antimalarial activity in vitro against chloroquine sensitive and resistant Plasmodium falciparum strains. Inhibitory concentrations at 50%, 90% and 95% were determined as 10.27±2.79, 53.53±6.26 and 73.78±6.92 µg/ml against the chloroquine-sensitive strains; 10.37±1.43, 56.99±11.07 and 72.79±8.59 µg/ml against chloroquine resistant of Plasmodium falciparum strains. C-PC was found to have antimalarial activity even at a concentration of 3.0µg/ml. The possible mechanism might be relied on the destruction of polymerization of haemozoin by binding of C-PC with ferriprotoporphyrin-IX at the water surface of the plasma membrane

Isolation and Purification of C-phycocyanin From Nostoc Muscorum (Cyanophyceae and Cyanobacteria) Exhibits Antimalarial Activity in Vitro

The phycobilin pigments are intensively fluorescent and water soluble. They are categorized into three types, such as pigments containing high, intermediate and low energies are phycoerythrins (phycoerythrocyanins), phycocyanins and allophycocyanins, respectively. Besides light harvesting, the phycobiliproteins have shown industrial and biomedical importance. Among them, C-phycocyanin (C-PC) has been considered to be the most preferred one. The present study was undertaken to evaluate the antimalarial activity of C-PC isolated from a nitrogen-fixing cyanobacterium and Nostoc muscorum. C-PC was extracted and purified by acetone extraction and ammonium sulfate precipitation and dialysis followed by amicon filtration. It was isolated as a~124 kDa water soluble protein molecule. It showed antimalarial activity in vitro against chloroquine sensitive and resistant Plasmodium falciparum strains. Inhibitory concentrations at 50%, 90% and 95% were determined as 10.27±2.79, 53.53±6.26 and 73.78±6.92 µg/ml against the chloroquine-sensitive strains; 10.37±1.43, 56.99±11.07 and 72.79±8.59 µg/ml against chloroquine resistant of Plasmodium falciparum strains. C-PC was found to have antimalarial activity even at a concentration of 3.0µg/ml. The possible mechanism might be relied on the destruction of polymerization of haemozoin by binding of C-PC with ferriprotoporphyrin-IX at the water surface of the plasma membrane

Assessment of therapeutic efficacy of chloroquine and sulphadoxine-pyrimethamine in uncomplicated falciparum malaria

A standardised protocol has been developed by World Health Organization (CDS/RBM/2002) toassess the efficacy of common antimalarials in the treatment of clinically manifested infection withuncomplicated P. falciparum malaria for areas with low to moderate transmission. The therapeuticefficacy protocol is based on clinical and parasitological responses of the patients and it has thepurpose of determining the practical efficacy of the drug regimen in study areas with the ultimateobjective of ascertaining its continued usefulness or the necessity for replacing it in the routinetreatment. Present study has been conducted at seven sites—Kathiatali and Simonabasti of DistrictNowgaon, Assam; Sonapur and Boko of District Kamrup, Assam; Keonjhar Town, Padampur andBasudebpur of District Keonjhar, Orissa. In order to reduce the patient recruitment time, health centreclose to well-defined community was identified to conduct the activities at peak malaria seasonby selecting local pockets and organising mobile clinics. Microscopically confirmed cases of P. falciparumwere enrolled according to the criteria for inclusion and exclusion. Treatment with recommendeddrug was given under supervision and a follow-up schedule at various intervals for 28days was maintained. In chloroquine (CQ) study areas, wherever patients showed treatment failure,they were treated with second line drug—sulphadoxine-pyrimethamine (SP) combination and thenfollowed-up as per study protocol. It was observed that 30% cases showed treatment failure to CQin District Nowgaon, where revised drug policy has already been introduced. In Kamrup district,treatment failure with CQ was found to be less than 25%, which denotes the said regimen is still effective.Almost all the patients from Padampur and Basudebpur of District Keonjhar responded toCQ, treatment failure was noticed only in two patients (3%). The antifolate combination found to befully effective as second line and also as first line wherever revised drug policy has been introduced

Congenital malaria with atypical presentation: A case report from low transmission area in India

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Molecular screening of blue mussels indicated high mid-summer prevalence of human genogroup II Noroviruses, including the pandemic “GII.4 2012” variants in UK coastal waters during 2013

Pandemic norovirus in coastal blue mussels during summer in UK This molecular study is the first report, to the best of our knowledge, on identification of norovirus, NoV GII.4 Sydney 2012 variants, from blue mussels collected from UK coastal waters. Blue mussels (three pooled samples from twelve mussels) collected during the 2013 summer months from UK coastal sites were screened by RT-PCR assays. PCR products of RdRP gene for noroviruses were purified, sequenced and subjected to phylogenetic analysis. All the samples tested positive for NoVs. Sequencing revealed that the NoV partial RdRP gene sequences from two pooled samples clustered with the pandemic “GII.4 Sydney variants” whilst the other pooled sample clustered with the NoV GII.2 variants. This molecular study indicated mussel contamination with pathogenic NoVs even during mid-summer in UK coastal waters which posed potential risk of NoV outbreaks irrespective of season. As the detection of Sydney 2012 NoV from our preliminary study of natural coastal mussels interestingly corroborated with NoV outbreaks in nearby areas during the same period, it emphasizes the importance of environmental surveillance work for forecast of high risk zones of NoV outbreaks

Genetic structure of Plasmodium falciparum field isolates in eastern and north-eastern India

<p>Abstract</p> <p>Background</p> <p>Molecular techniques have facilitated the studies on genetic diversity of <it>Plasmodium </it>species particularly from field isolates collected directly from patients. The <it>msp-1 </it>and <it>msp-2 </it>are highly polymorphic markers and the large allelic polymorphism has been reported in the block 2 of the <it>msp-1 </it>gene and the central repetitive domain (block3) of the <it>msp-2 </it>gene. Families differing in nucleotide sequences and in number of repetitive sequences (length variation) were used for genotyping purposes. As limited reports are available on the genetic diversity existing among <it>Plasmodium falciparum </it>population of India, this report evaluates the extent of genetic diversity in the field isolates of <it>P. falciparum </it>in eastern and north-eastern regions of India.</p> <p>Methods</p> <p>A study was designed to assess the diversity of <it>msp-1 </it>and <it>msp-2 </it>among the field isolates from India using allele specific nested PCR assays and sequence analysis. Field isolates were collected from five sites distributed in three states namely, Assam, West Bengal and Orissa.</p> <p>Results</p> <p><it>P. falciparum </it>isolates of the study sites are highly diverse in respect of length as well as sequence motifs with prevalence of all the reported allelic families of <it>msp-1 </it>and <it>msp-2</it>. Prevalence of identical allelic composition as well as high level of sequence identity of alleles suggest a considerable amount of gene flow between the <it>P. falciparum </it>populations of different states. A comparatively higher proportion of multiclonal isolates as well as multiplicity of infection (MOI) was observed among isolates of highly malarious districts Karbi Anglong (Assam) and Sundergarh (Orissa). In all the five sites, R033 family of <it>msp-1 </it>was observed to be monomorphic with an allele size of 150/160 bp. The observed 80–90% sequence identity of Indian isolates with data of other regions suggests that Indian <it>P. falciparum </it>population is a mixture of different strains.</p> <p>Conclusion</p> <p>The present study shows that the field isolates of eastern and north-eastern regions of India are highly diverse in respect of <it>msp-1 </it>(block 2) and <it>msp-2 </it>(central repeat region, block 3). As expected Indian isolates present a picture of diversity closer to southeast Asia, Papua New Guinea and Latin American countries, regions with low to meso-endemicity of malaria in comparison to African regions of hyper- to holo-endemicity.</p

Stage-specific cytosolic protein kinase C-like activity in human malarial parasite Plasmodium falciparum

145-151Protein kinase C (PKC)-like activity was characterized in malarial parasite Plasmodium falciparum and its involvement in growth, maturation and differentiation functions, during the asexual stages (ring, trophozoite and schizont) of development was studied. PKC-like activity was found distributed in all the stages of the parasite maturation. The activity was predominantly cytosolic, however it was also present in the membrane fraction. The activation of cytosolic PKC required Ca²⁺, phosphatidyl serine (PS), and either diacylglycerol or phorbol myristate acetate (PMA). The 9-fold increase in the activity was observed in the presence of the co-factors (Ca²⁺, PS and PMA) in the late trophozoite stage, as compared to the ring stage. The activation of trophozoites with PMA resulted in redistribution of PKC-like activity from cytosol to membrane fractions. An antimalarial drug, chloroquine (CQ) inhibited directly the PKC-like activity in a dose-dependent manner (IC₅₀ of 45 nM) in trophozoites of chloroquine-sensitive CQ(S) strains, however, the activity remained unaltered in the chloroquine-resistant CQ(R) strains. Kinetic studies showed that the inhibition of cytosolic PKC-like activity by CQ was non-competitive with respect to ATP, histone and PS. The results suggest that the PKC-like activity is developmentally expressed during the parasitic survival and development

CAD Model to Predict the Effect of Radome on the Characteristics of Rectangular Patch Antenna

A simple CAD model based on cavity model analysis is proposed to compute accurately the resonant frequency, input impedance, and gain of radome loaded rectangular patch antenna. The computed values using present model for wide range of radome parameters are compared with different theoretical and experimental values available in open literature. To validate the present model, we have performed several sets of experiments. The present model shows very close agreements with the experiments compared to the other models. We have also used electromagnetic software (HFSS) to generate simulated data. (c) 2013 Wiley Periodicals, Inc

Enhanced expression of Plasmodium falciparum heat shock protein PFHSP70-I at higher temperatures and parasite survival

The effect of various body temperatures, encountered during malaria fever, on the synthesis of Plasmodium falciparum heat-shock protein called PFHSP70-I and parasite growth rates among five different isolates are described. The results show that after the exposure of parasites at 39°C for 30 min the amount of PFHSP70-I in all five isolates increased markedly and significantly, whereas parasite growth rates and the amount of total blood stage antigens remained almost unaffected. This indicates that the PFHSP70-I gene responds to heat-shock by producing higher amounts of PFHSP70-I protein, presumably to protect the parasite from being killed during malaria fever