Deletion of a Malaria Invasion Gene Reduces Death and Anemia, in Model Hosts

Malaria parasites induce complex cellular and clinical phenotypes, including anemia, cerebral malaria and death in a wide range of mammalian hosts. Host genes and parasite ‘toxins’ have been implicated in malarial disease, but the contribution of parasite genes remains to be fully defined. Here we assess disease in BALB/c mice and Wistar rats infected by the rodent malaria parasite Plasmodium berghei with a gene knock out for merozoite surface protein (MSP) 7. MSP7 is not essential for infection but in P. falciparum, it enhances erythrocyte invasion by 20%. In vivo, as compared to wild type, the P. berghei Δmsp7 mutant is associated with an abrogation of death and a decrease from 3% to 2% in peak, circulating parasitemia. The Δmsp7 mutant is also associated with less anemia and modest increase in the size of follicles in the spleen. Together these data show that deletion of a single parasite invasion ligand modulates blood stage disease, as measured by death and anemia. This work is the first to assess the contribution of a gene present in all plasmodial species in severe disease

RIC-7 Promotes Neuropeptide Secretion

Secretion of neurotransmitters and neuropeptides is mediated by exocytosis of distinct secretory organelles, synaptic vesicles (SVs) and dense core vesicles (DCVs) respectively. Relatively little is known about factors that differentially regulate SV and DCV secretion. Here we identify a novel protein RIC-7 that is required for neuropeptide secretion in Caenorhabditis elegans. The RIC-7 protein is expressed in all neurons and is localized to presynaptic terminals. Imaging, electrophysiology, and behavioral analysis of ric-7 mutants indicates that acetylcholine release occurs normally, while neuropeptide release is significantly decreased. These results suggest that RIC-7 promotes DCV–mediated secretion

Measurement of the inclusive and dijet cross-sections of b-jets in pp collisions at sqrt(s) = 7 TeV with the ATLAS detector

The inclusive and dijet production cross-sections have been measured for jets containing b-hadrons (b-jets) in proton-proton collisions at a centre-of-mass energy of sqrt(s) = 7 TeV, using the ATLAS detector at the LHC. The measurements use data corresponding to an integrated luminosity of 34 pb^-1. The b-jets are identified using either a lifetime-based method, where secondary decay vertices of b-hadrons in jets are reconstructed using information from the tracking detectors, or a muon-based method where the presence of a muon is used to identify semileptonic decays of b-hadrons inside jets. The inclusive b-jet cross-section is measured as a function of transverse momentum in the range 20 < pT < 400 GeV and rapidity in the range |y| < 2.1. The bbbar-dijet cross-section is measured as a function of the dijet invariant mass in the range 110 < m_jj < 760 GeV, the azimuthal angle difference between the two jets and the angular variable chi in two dijet mass regions. The results are compared with next-to-leading-order QCD predictions. Good agreement is observed between the measured cross-sections and the predictions obtained using POWHEG + Pythia. MC@NLO + Herwig shows good agreement with the measured bbbar-dijet cross-section. However, it does not reproduce the measured inclusive cross-section well, particularly for central b-jets with large transverse momenta.Comment: 10 pages plus author list (21 pages total), 8 figures, 1 table, final version published in European Physical Journal

Hexahydroquinolines are antimalarial candidates with potent blood-stage and transmission-blocking activity

Hexahydroquinolines are antimalarial candidates with potent blood-stage and transmission-blocking activityAntimalarial compounds with dual therapeutic and transmission-blocking activity are desired as high-value partners for combination therapies. Here, we report the identification and characterization of hexahydroquinolines (HHQs) that show low nanomolar potency against both pathogenic and transmissible intra-erythrocytic forms of the malaria parasite Plasmodium falciparum. This activity translates into potent transmission-blocking potential, as shown by in vitro male gamete formation assays and reduced oocyst infection and prevalence in Anopheles mosquitoes. In vivo studies illustrated the ability of lead HHQs to suppress Plasmodium berghei blood-stage parasite proliferation. Resistance selection studies, confirmed by CRISPR-Cas9-based gene editing, identified the digestive vacuole membrane-spanning transporter PfMDR1 (P. falciparum multidrug resistance gene-1) as a determinant of parasite resistance to HHQs. Haemoglobin and haem fractionation assays suggest a mode of action that results in reduced haemozoin levels and might involve inhibition of host haemoglobin uptake into intra-erythrocytic parasites. Furthermore, parasites resistant to HHQs displayed increased susceptibility to several first-line antimalarial drugs, including lumefantrine, confirming that HHQs have a different mode of action to other antimalarials drugs for which PfMDR1 is known to confer resistance. This work evokes therapeutic strategies that combine opposing selective pressures on this parasite transporter as an approach to countering the emergence and transmission of multidrug-resistant P. falciparum malaria.The authors thank T.T. Diagana (Novartis Institute for Tropical Diseases, Singapore) for provision of the compounds, the Red Cross (Australia and the USA) for the provision of human blood for cell cultures, and G. Stevenson for assistance with the triaging of compounds following screening. The authors acknowledge the Bill and Melinda Gates Foundation (grant OPP1040399 to D.A.F. and V.M.A. and grant OPP1054480 to E.A.W. and D.A.F.), the National Institutes of Health (grant R01 AI103058 to E.A.W. and D.A.F., grant R01 AI50234 to D.A.F, and R01 AI110329 to T.J.E.), the Australian Research Council (LP120200557 to V.M.A.) and the Medicines for Malaria Venture for their continued support. P.E.F. and M.I.V. are supported by the Northern Portugal Regional Operational Programme (NORTE 2020), under the Portugal 2020 Partnership Agreement, through the European Regional Development Fund (FEDER).info:eu-repo/semantics/publishedVersio

Disruption of plasmepsin-4 and merozoites surface protein-7 genes in Plasmodium berghei induces combined virulence-attenuated phenotype

Blood stage malaria parasites causing a mild and self limited infection in mice have been obtained with either radiation or chemical mutagenesis showing the possibility of developing an attenuated malaria vaccine. Targeted disruption of plasmepsin-4 (pm4) or the merozoite surface protein-7 (msp7) genes also induces a virulence-attenuated phenotype in terms of absence of experimental cerebral malaria (ECM), delayed increase of parasitemia and reduced mortality rate. The decrease in virulence in parasites lacking either pm4 or msp7 is however incomplete and dependent on the parasite and mouse strain combination. The sequential disruption of both genes induced remarkable virulence-attenuated blood-stage parasites characterized by a self-resolving infection with low levels of parasitemia and no ECM. Furthermore, convalescent mice were protected against the challenge with P. berghei or P. yoelii parasites for several months. These observations provide a proof-of-concept step for the development of human malaria vaccines based on genetically attenuated blood-stage parasites

Bacterial endosymbiont Cardinium cSfur genome sequence provides insights for understanding the symbiotic relationship in Sogatella furcifera host

Background: Sogatella furcifera is a migratory pest that damages rice plants and causes severe economic losses. Due to its ability to annually migrate long distances, S.furcifera has emerged as a major pest of rice in several Asian countries. Symbiotic relationships of inherited bacteria with terrestrial arthropods have significant implications. The genus Cardinium is present in many types of arthropods, where it influences some host characteristics. We present a report of a newly # identified strain of the bacterial endosymbiont Cardinium cSfur in S. furcifera. Result: From the whole genome of S. furcifera previously sequenced by our laboratory, we assembled the whole genome sequence of Cardinium cSfur. The sequence comprised 1,103,593 bp with a GC content of 39.2%. The phylogenetic tree of the Bacteroides phylum to which Cardinium cSfur belongs suggests that Cardinium cSfur is closely related to the other strains (Cardinium cBtQ1 and cEper1) that are members of the Amoebophilaceae family. Genome comparison between the host-dependent endosymbiont including Cardinium cSfur and freeliving bacteria revealed that the endosymbiont has a smaller genome size and lower GC content, and has lost some genes related to metabolism because of its special environment, which is similar to the genome pattern observed in other insect symbionts. Cardinium cSfur has limited metabolic capability, which makes it less contributive to metabolic and biosynthetic processes in its host. From our findings, we inferred that, to compensate for its limited metabolic capability, Cardinium cSfur harbors a relatively high proportion of transport proteins, which might act as the hub between it and its host. With its acquisition of the whole operon related to biotin synthesis and glycolysis related genes through HGT event, Cardinium cSfur seems to be undergoing changes while establishing a symbiotic relationship with its host. Conclusion: A novel bacterial endosymbiont strain (Cardinium cSfur) has been discovered. A genomic analysis of the endosymbiont in S. furcifera suggests that its genome has undergone certain changes to facilitate its settlement in the host. The envisaged potential reproduction manipulative ability of the new endosymbiont strain in its S. furcifera host has vital implications in designing eco-friendly approaches to combat the insect pest

Multidimensional pain assessment of preterm newborns at the 1st, 3rd and 7th days of life

CONTEXT AND OBJECTIVE: It is challenge to assess and treat pain in premature infants. The objective of this study was to compare the multidimensional pain assessment of preterm neonates subjected to an acute pain stimulus at 24 hours, 72 hours and seven days of life. DESIGN AND SETTING: Prospective cohort study, at Universidade Federal de São Paulo (UNIFESP). METHODS: Eleven neonates with gestational age less than 37 weeks that needed venepuncture for blood collection were studied. The exclusion criteria were Apgar score < 7 at five minutes, presence of any central nervous system abnormality, and discharge or death before seven days of life. Venepuncture was performed in the dorsum of the hand, and the heart rate, oxygen saturation and pain scales [Neonatal Facial Coding System (NFCS), Neonatal Infant Pain Scale (NIPS), and Premature Infant Pain Profile (PIPP)] were assessed at 24 hours, 72 hours and 7 days of life. NFCS and NIPS were evaluated prior to procedure (Tpre), during venepuncture (T0), and two (T2) and five (T5) minutes after needle withdrawal. Heart rate, O2 saturation and PIPP were measured at Tpre and T0. Mean values were compared by repeated-measurement analysis of variance. RESULTS: The pain parameters did not differ at 24 hours, 72 hours and 7 days of life: heart rate (p = 0.22), oxygen saturation (p = 0.69), NFCS (p = 0.40), NIPS (p = 0.32) and PIPP (p = 0.56). CONCLUSION: Homogeneous pain scores were observed following venepuncture in premature infants during their first week of life.CONTEXTO E OBJETIVO: É um desafio avaliar e tratar a dor do bebê prematuro. O objetivo deste estudo foi comparar, diante de um mesmo estímulo doloroso agudo, as respostas multidimensionais à dor obtidas ao longo da primeira semana de vida de prematuros. TIPO DE ESTUDO E LOCAL: Coorte prospectiva, na Universidade Federal de São Paulo (UNIFESP). MÉTODOS: Estudo de 11 neonatos com idade gestacional inferior a 37 semanas e necessidade de punção venosa para coleta de sangue, sendo excluídos aqueles com Apgar < 7 aos cinco minutos, alterações do sistema nervoso central e os que faleceram ou tiveram alta até sete dias de vida. A punção venosa foi feita no dorso da mão e avaliou-se a freqüência cardíaca, a saturação de oxigênio e as seguintes escalas de dor: NFCS (Neonatal Facial Coding System), NIPS (Neonatal Infant Pain Scale) e PIPP (Premature Infant Pain Profile) com 24, 72 horas e no sétimo dia de vida. A NFCS e a NIPS foram pontuadas antes da punção venosa (Tpré), durante (T0), dois (T2) e cinco (T5) minutos após. A freqüência cardíaca, a saturação de oxigênio e a PIPP foram analisadas em Tpré e T0. Compararam-se os valores médios das variáveis nos três momentos por análise de variância com medidas repetidas. RESULTADOS: Não houve diferenças no primeiro, terceiro e sétimo dias para freqüência cardíaca (p = 0,22), saturação de oxigênio (p = 0,69), NFCS (p = 0,40), NIPS (p = 0,32) e PIPP (p = 0,56). CONCLUSÃO: Houve homogeneidade da avaliação da dor causada por punção venosa em prematuros, ao longo da primeira semana de vida.Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Universidade Federal de São Paulo (UNIFESP) Escola Paulista de Medicina Department of PediatricsUniversidade Federal de São Paulo (UNIFESP) Escola Paulista de Medicina Department of Preventive MedicineUNIFESP, EPM, Department of PediatricsUNIFESP, EPM, Department of Preventive MedicineCAPES: 1068-02SciEL