1,303 research outputs found

    Pattern of humoral immune response to Plasmodium falciparum blood stages in individuals presenting different clinical expressions of malaria

    Get PDF
    Abstract\ud \ud \ud \ud Background\ud \ud The development of protective immunity against malaria is slow and to be maintained, it requires exposure to multiple antigenic variants of malaria parasites and age-associated maturation of the immune system. Evidence that the protective immunity is associated with different classes and subclasses of antibodies reveals the importance of considering the quality of the response. In this study, we have evaluated the humoral immune response against Plasmodium falciparum blood stages of individuals naturally exposed to malaria who live in endemic areas of Brazil in order to assess the prevalence of different specific isotypes and their association with different malaria clinical expressions.\ud \ud \ud \ud Methods\ud \ud Different isotypes against P. falciparum blood stages, IgG, IgG1, IgG2, IgG3, IgG4, IgM, IgE and IgA, were determined by ELISA. The results were based on the analysis of different clinical expressions of malaria (complicated, uncomplicated and asymptomatic) and factors related to prior malaria exposure such as age and the number of previous clinical malaria attacks. The occurrence of the H131 polymorphism of the FcγIIA receptor was also investigated in part of the studied population.\ud \ud \ud \ud Results\ud \ud The highest levels of IgG, IgG1, IgG2 and IgG3 antibodies were observed in individuals with asymptomatic and uncomplicated malaria, while highest levels of IgG4, IgE and IgM antibodies were predominant among individuals with complicated malaria. Individuals reporting more than five previous clinical malaria attacks presented a predominance of IgG1, IgG2 and IgG3 antibodies, while IgM, IgA and IgE antibodies predominated among individuals reporting five or less previous clinical malaria attacks. Among individuals with uncomplicated and asymptomatic malaria, there was a predominance of high-avidity IgG, IgG1, IgG2 antibodies and low-avidity IgG3 antibodies. The H131 polymorphism was found in 44.4% of the individuals, and the highest IgG2 levels were observed among asymptomatic individuals with this allele, suggesting the protective role of IgG2 in this population.\ud \ud \ud \ud Conclusion\ud \ud Together, the results suggest a differential regulation in the anti-P. falciparum antibody pattern in different clinical expressions of malaria and showed that even in unstable transmission areas, protective immunity against malaria can be observed, when the appropriated antibodies are produced.We would like to especially thank Dr. Cristóvão Luis Pitangueira Mangueira, Flávia Cristina Kinskowski and Milca Geane de Lamos Valim at the Central Laboratory of the Clinical Hospital for participating in the determination of the total IgE and IgA levels. This work was supported by FAPESP (process number 2001/04073-5) and Laboratório de Investigações Médicas do Hospital das Clínicas da Faculdade de Medicina da Universidade de São Paulo (LIM-48/HCFMUSP)We would like to especially thank Dr. Cristóvão Luis Pitangueira Mangueira, Flávia Cristina Kinskowski and Milca Geane de Lamos Valim at the Central Laboratory of the Clinical Hospital for participating in the determination of the total IgE and IgA levels. This work was supported by FAPESP (process number 2001/040735) and Laboratório de Investigações Médicas do Hospital das Clínicas da Faculdade de Medicina da Universidade de São Paulo (LIM48/HCFMUSP

    Survey of Zoonotic Diarrheagenic Protist and Hepatitis E Virus in Wild Boar (Sus scrofa) of Portugal

    Get PDF
    Simple Summary Enteropathogenic viruses, such as hepatitis E virus, and diarrhoeagenic protists have been frequently reported in swine and can infect a wide range of mammals, including humans. Data on their fecal shedding and circulation pathways are still lacking or incomplete. Hence, the aim of the present study was to characterize the presence of microeukaryotes and HEV in the wild boar of Portugal. Of the 144 samples tested, 2 showed the presence of Cryptosporidium scrofarum, 21 Balantioides coli, 42 Blastocystis ST5, and 4 HEV genotype 3. The present work shows that potentially zoonotic protozoa and HEV are circulating in wild boar populations in Portugal. Enteropathogenic parasites and viruses have been frequently reported in swine and can infect a wide range of mammals, including humans. Among the wide variety of parasites infecting swine, diarrhoeagenic protists are among those that cause significant morbidity. Hepatitis E virus (HEV) has also been reported both in domestic pigs and wild boar and is known to have an important public health significance. These agents share the fecal-oral transmission route, but data on their fecal shedding and circulation pathways are still lacking or incomplete. Hence, the aim of the present study was to characterize the presence of microeukaryotes and HEV in the wild boar of Portugal. Wild boar stool samples (n = 144) were obtained during the official hunting seasons (October to February) in 2018/2019, 2019/2020, and 2021/2022 and tested for Cryptosporidium spp., Balantioides coli, Giardia duodenalis, Blastocystis sp., Enterocytozoon bieneusi and HEV by molecular assays, followed by sequencing and phylogenetic analysis. We have detected Cryptosporidium scrofarum (1.4%, 95% CI: 0.2-4.9), B. coli (14.6%, 95% CI: 9.2-21.4), Blastocystis ST5 (29.2%, 95% CI: 21.9-37.2) and HEV genotype 3 (2.8%, 95% CI: 0.7-6.9; subgenotypes 3e and 3m). Co-infections were observed in thirteen animals where two were positive for both HEV and B. coli, one was positive for both C. scrofarum and Blastocystis ST5, and ten were positive for both B. coli and Blastocystis ST5. Giardia duodenalis and E. bieneusi were not detected in the surveyed wild boar population. As far as we know, this is the first report describing protist infections by Cryptosporidium spp., B. coli, and Blastocystis sp., as well as the first identification of the emerging HEV genotype 3m in wild boar of Portugal. The present work shows that potentially zoonotic protozoa and HEV are circulating in wild boar populations in Portugal. Awareness and epidemic-surveillance network implementation measures targeting wild boar are needed to prevent the spread of these pathogenic agents to humans.This research was funded by Fundacao para Ciencia e Tecnologia (FCT), grant number 2021.09461.BD

    Phenotyping Superagers Using Resting-State fMRI

    Get PDF
    BACKGROUND AND PURPOSE: Superagers are defined as older adults with episodic memory performance similar or superior to that in middle-aged adults. This study aimed to investigate the key differences in discriminative networks and their main nodes between superagers and cognitively average elderly controls. In addition, we sought to explore differences in sensitivity in detecting these functional activities across the networks at 3T and 7T MR imaging fields. MATERIALS AND METHODS: Fifty-five subjects 80 years of age or older were screened using a detailed neuropsychological protocol, and 31 participants, comprising 14 superagers and 17 cognitively average elderly controls, were included for analysis. Participants underwent resting-state-fMRI at 3T and 7T MR imaging. A prediction classification algorithm using a penalized regression model on the measurements of the network was used to calculate the probabilities of a healthy older adult being a superager. Additionally, ORs quantified the influence of each node across preselected networks. RESULTS: The key networks that differentiated superagers and elderly controls were the default mode, salience, and language networks. The most discriminative nodes (ORs > 1) in superagers encompassed areas in the precuneus posterior cingulate cortex, prefrontal cortex, temporoparietal junction, temporal pole, extrastriate superior cortex, and insula. The prediction classification model for being a superager showed better performance using the 7T compared with 3T resting-state-fMRI data set. CONCLUSIONS: Our findings suggest that the functional connectivity in the default mode, salience, and language networks can provide potential imaging biomarkers for predicting superagers. The 7T field holds promise for the most appropriate study setting to accurately detect the functional connectivity patterns in superagers

    Clinical safety of dichlorvos (45%), cypermethrin (5%) and piperonyl butoxide (25%) administered by spray on the skin of cattle

    Get PDF
    ABSTRACT Objective. Due to the importance of controlling ectoparasites, associated with the necessity of technical knowledge on the safety of topical treatment with organophosphates, pyrethroids and piperonyl butoxide to the animal organism, this bioassay was carried out to evaluate the clinical safety of the association of dichlorvos (45%) + cypermethrin (5%) + piperonyl butoxide (25%) administered by spray on the skin of cattle, through the study of clinical parameters, biochemical, haematological and behavioral changes. Materials and methods. Sixteen crossbred animals with a mean age of 18 months, males and females grouped into two treatments with eight animals each: T1 (1:800 v/v) and T2 (1:200 v/v). Were collected blood samples at six different times: before treatment (BT), 24, 48, 72, 96 and 192 hours post treatment (HPT). Results. The antiparasitic association administered by spray on the skin did not result in changes in the enzymatic activity of ALT, AST, GGT and ALP, as well as in serum albumin, triglycerides, cholesterol, urea and creatinine, demonstrating the safety of this antiparasitic compound for maintaining hepatic and renal functionality. The erythrocyte, leukocyte and platelet studies showed no changes caused by treatments, and no clinical signs and behavioral changes were observed after treatment. Conclusions. These findings demonstrated good safety margin for spray treatment on the skin with this antiparasitic compound, even when administered at a dilution of 1:200 v/v, which is four times the dose recommended for ectoparasite control

    Biological evaluation of hydroxynaphthoquinones as anti-malarials

    Get PDF
    Abstract\ud \ud \ud \ud Background\ud The hydroxynaphthoquinones have been extensively investigated over the past 50 years for their anti-malarial activity. One member of this class, atovaquone, is combined with proguanil in Malarone®, an important drug for the treatment and prevention of malaria.\ud \ud \ud \ud Methods\ud Anti-malarial activity was assessed in vitro for a series of 3-alkyl-2-hydroxy-1,4-naphthoquinones (N1-N5) evaluating the parasitaemia after 48 hours of incubation. Potential cytotoxicity in HEK293T cells was assessed using the MTT assay. Changes in mitochondrial membrane potential of Plasmodium were measured using the fluorescent dye Mitrotracker Red CMXROS.\ud \ud \ud \ud Results\ud Four compounds demonstrated IC50s in the mid-micromolar range, and the most active compound, N3, had an IC50 of 443 nM. N3 disrupted mitochondrial membrane potential, and after 1 hour presented an IC50ΔΨmit of 16 μM. In an in vitro cytotoxicity assay using HEK 293T cells N3 demonstrated no cytotoxicity at concentrations up to 16 μM.\ud \ud \ud \ud Conclusions\ud N3 was a potent inhibitor of mitochondrial electron transport, had nanomolar activity against cultured Plasmodium falciparum and showed minimal cytotoxicity. N3 may serve as a starting point for the design of new hydroxynaphthoquinone anti-malarials.This work was supported by FAPESP (Fundação de Amparo a Pesquisa de São Paulo) (07/52924-0), by Malaria Pronex, and by a INCT-INBqMed (Instituto Nacional de Ciência e Tecnologia- Instituto Nacional de Ciência e Tecnologia de Biotecnologia Estrutural e Química Medicinal em Doenças Infecciosa) grant. C.R.S. Garcia and V. Ferreira are CNPQ (Conselho Nacional de Pesquisa) fellows. D.S. received a CAPES (Coordenação de Aperfeiçoamento de Pessoal de Nível Superior) Fellowship. D.R. da Rocha thanks FAPERJ (Fundação de Amparo a Pesquisa do Rio De Janeiro) for their doctoral fellowship. LNC and MM received a FAPESP Fellowship. Thanks are due to the CNPQ, CAPES and FAPERJ for funding this work.This work was supported by FAPESP (Fundação de Amparo a Pesquisa de São Paulo) (07/529240), by Malaria Pronex, and by a INCTINBqMed (Instituto Nacional de Ciência e Tecnologia Instituto Nacional de Ciência e Tecnologia de Biotecnologia Estrutural e Química Medicinal em Doenças Infecciosa) grant. C.R.S. Garcia and V. Ferreira are CNPQ (Conselho Nacional de Pesquisa) fellows. D.S. received a CAPES (Coordenação de Aperfeiçoamento de Pessoal de Nível Superior) Fellowship. D.R. da Rocha thanks FAPERJ (Fundação de Amparo a Pesquisa do Rio De Janeiro) for their doctoral fellowship. LNC and MM received a FAPESP Fellowship. Thanks are due to the CNPQ, CAPES and FAPERJ for funding this work

    Chromatin differentiation between Theobroma cacao L. and T. grandiflorum Schum

    Get PDF
    A comparative analysis of mitotic chromosomes of Theobroma cacao (cacao) and T. grandiflorum (cupuaçu) was performed aiming to identify cytological differences between the two most important species of this genus. Both species have symmetric karyotypes, with 2n = 20 metacentric chromosomes ranging in size from 2.00 to 1.19 μm (cacao) and from 2.21 to 1.15 μm (cupuaçu). The interphase nuclei of both species were of the arreticulate type, displaying up to 20 chromocentres, which were more regularly shaped in cacao than in cupuaçu. Prophase chromosomes of both species were more condensed in the proximal region, sometimes including the whole short arm. Both species exhibited only one pair of terminal heterochromatic bands, positively stained with chromomycin A 3 , which co-localized with the single 45S rDNA site. Each karyotype displayed a single 5S rDNA site in the proximal region of another chromosome pair. Heterochromatic bands were also observed on the centromeric/pericentromeric regions of all 20 chromosomes of cacao after C-banding followed by Giemsa or DAPI staining, whereas in cupuaçu they were never detected. These data suggest that the chromosomes of both species have been largely conserved and their pericentromeric chromatin is the only citologically differentiated region

    Factors associated with involuntary hospital admissions in technology-dependent children

    Get PDF
    Abstract OBJECTIVE To identify the factors associated with involuntary hospital admissions of technology-dependent children, in the municipality of Ribeirão Preto, São Paulo State, Brazil. METHOD A cross-sectional study, with a quantitative approach. After an active search, 124 children who qualified under the inclusion criteria, that is to say, children from birth to age 12, were identified. Data was collected in home visits to mothers or the people responsible for the children, through the application of a questionnaire. Analysis of the data followed the assumptions of the Generalized Linear Models technique. RESULTS 102 technology-dependent children aged between 6 months and 12 years participated in the study, of whom 57% were male. The average number of involuntary hospital admissions in the previous year among the children studied was 0.71 (±1.29). In the final model the following variables were significantly associated with the outcome: age (OR=0.991; CI95%=0.985-0.997), and the number of devices (OR=0.387; CI95%=0.219-0.684), which were characterized as factors of protection and quantity of medications (OR=1.532; CI95%=1.297-1.810), representing a risk factor for involuntary hospital admissions in technology-dependent children. CONCLUSION The results constitute input data for consideration of the process of care for technology-dependent children by supplying an explanatory model for involuntary hospital admissions for this client group

    Impact of the COVID-19 Pandemic on Elective and Emergency Surgeries, and Postoperative Mortality in a Brazilian Metropolitan Area: A Time-Series Cohort Study

    Get PDF
    Dilson Palhares Ferreira,1,&ast; Claudia Vicari Bolognani,2,3,&ast; Levy Aniceto Santana,2,&ast; Sergio Eduardo Soares Fernandes,2,3,&ast; Matheus Serwy Fiuza de Moraes,3,&ast; Luana Argollo Souza Fernandes,3,&ast; Daniella Queiroz de Oliveira,3,&ast; Rosália Bezerra de Santana,3,&ast; Leila Bernarda Donato Gottems,2,3,&ast; Fabio Ferreira Amorim1– 4,&ast; 1Graduation Program in Health Sciences, University of Brasília (Unb), Brasília, Brazil; 2Department of Research and Scientific Communication, Escola Superior de Ciências da Saúde (ESCS), Brasília, Brazil; 3Medical School, Escola Superior de Ciências da Saúde (ESCS), Brasília, Brazil; 4Graduation Program in Health Sciences of School Health Sciences, Escola Superior de Ciências da Saúde (ESCS), Brasília, Brazil&ast;These authors contributed equally to this workCorrespondence: Fabio Ferreira Amorim; Dilson Palhares Ferreira, Graduation Program in Health Sciences, University of Brasília (UnB), Faculty of Health Sciences Campus University Darcy Ribeiro S/N - Asa Norte, Federal District, Brasília, CEP: 70910-900, Brazil, Email [email protected]; [email protected]: The COVID-19 pandemic posed a worldwide challenge, leading to radical changes in surgical services. The primary objective of the study was to assess the impact of COVID-19 on elective and emergency surgeries in a Brazilian metropolitan area. The secondary objective was to compare the postoperative hospital mortality before and during the pandemic.Patients and Methods: Time-series cohort study including data of all patients admitted for elective or emergency surgery at the hospitals in the Public Health System of Federal District, Brazil, between March 2018 and February 2022, using data extracted from the Hospital Information System of Brazilian Ministry of Health (SIH/DATASUS) on September 30, 2022. A causal impact analysis was used to evaluate the impact of COVID-19 on elective and emergency surgeries and hospital mortality.Results: There were 174,473 surgeries during the study period. There was a reduction in overall (absolute effect per week: − 227.5; 95% CI: − 307.0 to − 149.0), elective (absolute effect per week: − 170.9; 95% CI: − 232.8 to − 112.0), and emergency (absolute effect per week: − 57.7; 95% CI: − 87.5 to − 27.7) surgeries during the COVID-19 period. Comparing the surgeries performed before and after the COVID-19 onset, there was an increase in emergency surgeries (53.0% vs 68.8%, P < 0.001) and no significant hospital length of stay (P = 0.112). The effect of the COVID-19 pandemic on postoperative hospital mortality was not statistically significant (absolute effect per week: 2.1, 95% CI: − 0.01 to 4.2).Conclusion: Our study showed a reduction in elective and emergency surgeries during the COVID-19 pandemic, possibly due to disruptions in surgical services. These findings highlight that it is crucial to implement effective strategies to prevent the accumulation of surgical waiting lists in times of crisis and improve outcomes for surgical patients.Keywords: COVID-19, surgical procedures, operative, elective surgical procedures, acute care surgery, hospital mortalit

    Verified and potential pathogens of predatory mites (Acari: Phytoseiidae)

    Get PDF
    Several species of phytoseiid mites (Acari: Phytoseiidae), including species of the genera Amblyseius, Galendromus, Metaseiulus, Neoseiulus, Phytoseiulus and Typhlodromus, are currently reared for biological control of various crop pests and/or as model organisms for the study of predator¿prey interactions. Pathogen-free phytoseiid mites are important to obtain high efficacy in biological pest control and to get reliable data in mite research, as pathogens may affect the performance of their host or alter their reproduction and behaviour. Potential and verified pathogens have been reported for phytoseiid mites during the past 25 years. The present review provides an overview, including potential pathogens with unknown host effects (17 reports), endosymbiotic Wolbachia (seven reports), other bacteria (including Cardinium and Spiroplasma) (four reports), cases of unidentified diseases (three reports) and cases of verified pathogens (six reports). From the latter group four reports refer to Microsporidia, one to a fungus and one to a bacterium. Only five entities have been studied in detail, including Wolbachia infecting seven predatory mite species, other endosymbiotic bacteria infecting Metaseiulus (Galendromus, Typhlodromus) occidentalis (Nesbitt), the bacterium Acaricomes phytoseiuli infecting Phytoseiulus persimilis Athias-Henriot, the microsporidium Microsporidium phytoseiuli infecting P. persimilis and the microsporidium Oligosproridium occidentalis infecting M. occidentalis. In four cases (Wolbachia, A. phytoseiuli, M. phytoseiuli and O. occidentalis) an infection may be connected with fitness costs of the host. Moreover, infection is not always readily visible as no obvious gross symptoms are present. Monitoring of these entities on a routine and continuous basis should therefore get more attention, especially in commercial mass-production. Special attention should be paid to field-collected mites before introduction into the laboratory or mass rearing, and to mites that are exchanged among rearing facilities. However, at present general pathogen monitoring is not yet practical as effects of many entities are unknown. More research effort is needed concerning verified and potential pathogens of commercially reared arthropods and those used as model organisms in research
    corecore