2,130 results on '"Pedro Da Silva"'
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2. Tuberculosis testing patterns in South Africa to identify groups that would benefit from increased investigation
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Anne N. Shapiro, Lesley Scott, Harry Moultrie, Karen R. Jacobson, Jacob Bor, Abdou M. Fofana, Graeme Dor, Norbert O. Ndjeka, Pedro da Silva, Koleka Mlisana, Helen E. Jenkins, and Wendy S. Stevens
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Medicine ,Science - Abstract
Abstract The National Health Laboratory Service (NHLS) collects all public health laboratory test results in South Africa, providing a cohort from which to identify groups, by age, sex, HIV, and viral suppression status, that would benefit from increased tuberculosis (TB) testing. Using NHLS data (2012–2016), we assessed levels and trends over time in TB diagnostic tests performed (count and per capita) and TB test positivity. Estimates were stratified by HIV status, viral suppression, age, sex, and province. We used logistic regression to estimate the odds of testing positive for TB by viral suppression status. Nineteen million TB diagnostic tests were conducted during period 2012–2016. Testing per capita was lower among PLHIV with viral suppression than those with unsuppressed HIV (0.08 vs 0.32) but lowest among people without HIV (0.03). Test positivity was highest among young adults (aged 15–35 years), males of all age groups, and people with unsuppressed HIV. Test positivity was higher for males without laboratory evidence of HIV than those with HIV viral suppression, despite similar individual odds of TB. Our results are an important national baseline characterizing who received TB testing in South Africa. People without evidence of HIV, young adults, and males would benefit from increased TB screening given their lower testing rates and higher test positivity. These high-test positivity groups can be used to guide future expansions of TB screening.
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- 2023
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3. Characteristics of women diagnosed with mpox infection compared to men: A case series from Brazil
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Carolina Coutinho, Mayara Secco Torres Silva, Thiago S. Torres, Eduardo Peixoto, Monica Avelar Magalhães, Sandra Wagner Cardoso, Gabriela Nazário, Maíra Mendonça, Mariana Menezes, Paula Maria Almeida, Paula Rita Dias de Brito de Carvalho, Shenon Bia Bedin, Aline Maria Almeida, Silvia Carvalho, Valdilea Gonçalves Veloso, Beatriz Grinsztejn, Luciane Velasque, André Figueiredo Accetta, André Miguel Japiassu, Bruna Rendelli, Desirée Vieira Santos, Gabriela Lisseth Umaña Robleda, Guilherme Amaral Calvet, Hugo Perazzo Pedroso Barbosa, Italo Guariz Ferreira, Jadir Rodrigues Fagundes Neto, João Paulo Bortot Soares, João Victor Jaegger de França, José Ricardo Hildebrant Coutinho, Katia Maria Azevedo, Larissa Villela, Luciana Truccoli, Luisa Fares, Luiz Ricardo Siqueira Camacho, Maira Braga Mesquita, Marcel Cunha, Marcel Trepow, Marcela Terra, Maria Roberta Meneguetti, Mariah Castro de Souza Pires, Pedro Amparo, Pedro da Silva Martins, Rafael Teixeira Fraga, Rodrigo Caldas Menezes, Rodrigo Otavio da Silva Escada, Rosangela Vieira Eiras, Sandro Antônio Pereira, and Wladmyr Davila da Silva
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Mpox ,HIV ,Women ,Gender identity ,Latin America ,Brazil ,Arctic medicine. Tropical medicine ,RC955-962 ,Infectious and parasitic diseases ,RC109-216 - Abstract
Background: Cisgender men were mostly affected during the 2022 mpox multinational outbreak, with few cases reported in women. This study compares the characteristics of individuals diagnosed with mpox infection according to gender in Rio de Janeiro. Methods: We obtained surveillance data of mpox cases notified to Rio de Janeiro State Health Department (June 12 to December 15, 2022). We compared women (cisgender or transgender) to men (cisgender or transgender) using chi-squared, Fisher's exact, and Mood's median tests. Results: A total of 1306 mpox cases were reported; 1188 (91.0%) men (99.8% cisgender, 0.2% transgender), 108 (8.3%) women (87.0% cisgender, 13.0% transgender), and 10 (0.8%) non-binary persons. Compared to men, women were more frequently older (40+years: 34.3% vs. 25.1%; p
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- 2023
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4. IRIS LEISHMANIOSE VISCERAL EM ÁREA NÃO ENDÊMICA: UM RELATO DE CASO
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Saulo Cristian Lima de Souza, Lucas Pereira Lima, Lucas Borges Gomes Ferreira Pinto, Luiza Britto Gomes, and Pedro da Silva Martins
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Leishmaniose Visceral Resconstituição Imune Hepatoesplenomegalia febril HIV ,Infectious and parasitic diseases ,RC109-216 ,Microbiology ,QR1-502 - Abstract
A supressão do HIV com a terapia antirretroviral (TAR) pode ser acompanhada pela piora paradoxal ou pelo desmascaramento de infecções oportunistas (IO) em decorrência da Síndrome Inflamatória de Reconstituição Imune (IRIS). A Leishmaniose Visceral (LV), geralmente subnotificada, é uma protozoose de alta letalidade quando não tratada e quase sempre uma hipótese negligenciada fora das áreas endêmicas. Neste trabalho, relatamos o caso de um homem, 24 anos, natural de Ipaporanga/CE, residente há 6 anos no Rio de Janeiro/RJ. Diagnosticado com HIV em dez/22, assintomático, iniciou TDF/3TC e DTG, apresentando carga viral (CV) de 1751cps/ml e CD4 de 60cel/mm3 (9%), coletados logo após a introdução da TAR. Em jan/23, ele é internado em hospital de referência com quadro agudo de febre, pancitopenia e hepatoesplenomegalia. Diante da suspeita clínica de otmailstoqu disseminada, foi iniciada Anfotericina B lipossomal (ABL) e realizada biópsia e aspirado de medula óssea para diagnósticos diferenciais. As pesquisas para tuberculose (BAAR, TRM-TB, cultura de escarro), criptococose (CrAg), sífilis (VDRL), hepatites virais e hemoculturas para fungos e bactérias foram todas negativas. Em uso regular da TAR, apresentava CV 630cps/ml e CD4 53cel/mm3 (10%). Após dez dias, diante de resultados negativos de otmailstoqu (Western Blot e antígeno urinário), a Anfotericina B foi suspensa. Entretanto, o paciente persistiu com visceromegalias e pancitopenia, com Coombs direto positivo e o mielograma demonstrando hiperplasia eritroide sem hemofagocitose, mantendo-se a suspeita de IO e motivando início de corticoterapia. Em fev/23, após revisão clínico-epidemiológica, foi solicitada sorologia para LV, com resultado reagente. Assim, a ABL foi reiniciada até a dose acumulada de 3g, tendo alta hospitalar subsequente. Desde mar/23, segue em profilaxia secundária ambulatorial com ABL quinzenal, com boa evolução clínica, resolução das citopenias e visceromegalias, sem recaídas ou reações adversas, alcançando CV 56cps/ml e CD4 162cel/mm3 (16%) em maio/23. Este caso sugere um desmascaramento de LV em área não endêmica, possivelmente deflagrada pela IRIS em um indivíduo previamente infectado. Neste contexto, o diagnóstico da LV exige alta suspeição clínica frente aos diversos diagnósticos diferenciais da hepatoesplenomegalia febril. Além do tratamento precoce e uso da profilaxia secundária, a supressão viral sustentada do HIV é primordial para resolução do quadro e prevenção de recidivas.
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- 2023
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5. Storage of Mycobacterium tuberculosis culture isolates in MicrobankTM beads at a South African laboratory
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Anura David, Lesley E. Scott, Pedro Da Silva, Elizabeth Mayne, and Wendy S. Stevens
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mycobacterium tuberculosis ,culture isolates ,storage ,liquid culture ,microbank beads ,Public aspects of medicine ,RA1-1270 ,Medicine (General) ,R5-920 - Abstract
Background: Mycobacterium tuberculosis complex (MTBC) isolates are typically stored at −70 °C in cryovials containing 1 mL aliquots of a liquid medium, with or without 50% glycerol. Multiple uses of the culture stock may decrease the strain viability while increasing the risk of culture contamination. Small culture aliquots may be more practical; however, storage capacity remains challenging. MicrobankTM beads (25 beads/vial) for the long-term storage of fungal cultures is well documented, but their use for storing MTBC isolates is uninvestigated. Objective: The study aimed to determine the feasibility of using MicrobankTM beads for long-term storage of MTBC isolates at a laboratory in South Africa. Methods: In February 2020, 20 isolates in liquid culture were stored in MicrobankTM beads, following an in-house developed protocol, at −70 °C. At defined time points (16 months [15 June 2021] and 21 months [18 November 2021]), two beads were retrieved from each storage vial and assessed for viability and level of contamination. Results: Stored liquid isolates demonstrated MTBC growth within an average time-to-detection of 18 days following retrieval, even at 21 months post storage. Contaminating organisms were detected in 2 of 80 (2.5%) culture isolates. Conclusion: MicrobankTM beads will allow for the reculture of up to 25 culture isolates using a reduced culture volume compared to current storage methods. MicrobankTM beads represent a storage solution for the medium-term storage of MTBC isolates. What this study adds: This study evaluated the use of MicrobankTM beads as an alternate method for storing MTBC culture isolates at −70 °C and provided a suitable option for medium-term storage of MTBC.
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- 2023
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6. Cross-municipality migration and spread of tuberculosis in South Africa
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Abdou M. Fofana, Harry Moultrie, Lesley Scott, Karen R. Jacobson, Anne N. Shapiro, Graeme Dor, Beth Crankshaw, Pedro Da Silva, Helen E. Jenkins, Jacob Bor, and Wendy S. Stevens
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Medicine ,Science - Abstract
Abstract Human migration facilitates the spread of infectious disease. However, little is known about the contribution of migration to the spread of tuberculosis in South Africa. We analyzed longitudinal data on all tuberculosis test results recorded by South Africa’s National Health Laboratory Service (NHLS), January 2011–July 2017, alongside municipality-level migration flows estimated from the 2016 South African Community Survey. We first assessed migration patterns in people with laboratory-diagnosed tuberculosis and analyzed demographic predictors. We then quantified the impact of cross-municipality migration on tuberculosis incidence in municipality-level regression models. The NHLS database included 921,888 patients with multiple clinic visits with TB tests. Of these, 147,513 (16%) had tests in different municipalities. The median (IQR) distance travelled was 304 (163 to 536) km. Migration was most common at ages 20–39 years and rates were similar for men and women. In municipality-level regression models, each 1% increase in migration-adjusted tuberculosis prevalence was associated with a 0.47% (95% CI: 0.03% to 0.90%) increase in the incidence of drug-susceptible tuberculosis two years later, even after controlling for baseline prevalence. Similar results were found for rifampicin-resistant tuberculosis. Accounting for migration improved our ability to predict future incidence of tuberculosis.
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- 2023
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7. A Nonspecific Lipid Transfer Protein with Potential Functions in Infection and Nodulation
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Mélanie Gasser, Nicole Alloisio, Pascale Fournier, Severine Balmand, Ons Kharrat, Joris Tulumello, Lorena Carro, Abdelaziz Heddi, Pedro Da Silva, Philippe Normand, Petar Pujic, and Hasna Boubakri
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Alnus glutinosa ,antimicrobial peptide ,Frankia ,immunity ,infection threads ,nitrogen fixation ,Microbiology ,QR1-502 ,Botany ,QK1-989 - Abstract
The response of Alnus glutinosa to Frankia alni ACN14a is driven by several sequential physiological events from calcium spiking and root-hair deformation to the development of the nodule. Early stages of actinorhizal symbiosis were monitored at the transcriptional level to observe plant host responses to Frankia alni. Forty-two genes were significantly upregulated in inoculated compared with noninoculated roots. Most of these genes encode proteins involved in biological processes induced during microbial infection, such as oxidative stress or response to stimuli, but a large number of them are not differentially modulated or downregulated later in the process of nodulation. In contrast, several of them remained upregulated in mature nodules, and this included the gene most upregulated, which encodes a nonspecific lipid transfer protein (nsLTP). Classified as an antimicrobial peptide, this nsLTP was immunolocalized on the deformed root-hair surfaces that are points of contact for Frankia spp. during infection. Later in nodules, it binds to the surface of F. alni ACN14a vesicles, which are the specialized cells for nitrogen fixation. This nsLTP, named AgLTP24, was biologically produced in a heterologous host and purified for assay on F. alni ACN14a to identify physiological effects. Thus, the activation of the plant immunity response occurs upon first contact, while the recognition of F. alni ACN14a genes switches off part of the defense system during nodulation. AgLTP24 constitutes a part of the defense system that is maintained all along the symbiosis, with potential functions such as the formation of infection threads or nodule primordia to the control of F. alni proliferation. [Graphic: see text] Copyright © 2022 The Author(s). This is an open access article distributed under the CC BY-NC-ND 4.0 International license.
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- 2022
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8. Pesticide-Free Robotic Control of Aphids as Crop Pests
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Virginie Lacotte, Toan NGuyen, Javier Diaz Sempere, Vivien Novales, Vincent Dufour, Richard Moreau, Minh Tu Pham, Kanty Rabenorosoa, Sergio Peignier, François G. Feugier, Robin Gaetani, Thomas Grenier, Bruno Masenelli, Pedro da Silva, Abdelaziz Heddi, and Arnaud Lelevé
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farming ,robotics ,aphid detection ,laser-based neutralization ,deep learning ,image-based visual servoing ,Agriculture (General) ,S1-972 ,Engineering (General). Civil engineering (General) ,TA1-2040 - Abstract
Because our civilization has relied on pesticides to fight weeds, insects, and diseases since antiquity, the use of these chemicals has become natural and exclusive. Unfortunately, the use of pesticides has progressively had alarming effects on water quality, biodiversity, and human health. This paper proposes to improve farming practices by replacing pesticides with a laser-based robotic approach. This study focused on the neutralization of aphids, as they are among the most harmful pests for crops and complex to control. With the help of deep learning, we developed a mobile robot that spans crop rows, locates aphids, and neutralizes them with laser beams. We have built a prototype with the sole purpose of validating the localization-neutralization loop on a single seedling row. The experiments performed in our laboratory demonstrate the feasibility of detecting different lines of aphids (50% detected at 3 cm/s) and of neutralizing them (90% mortality) without impacting the growth of their host plants. The results are encouraging since aphids are one of the most challenging crop pests to eradicate. However, enhancements in detection and mainly in targeting are necessary to be useful in a real farming context. Moreover, robustness regarding field conditions should be evaluated.
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- 2022
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9. Intestinal GCN2 controls Drosophila systemic growth in response to Lactiplantibacillus plantarum symbiotic cues encoded by r/tRNA operons
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Théodore Grenier, Jessika Consuegra, Mariana G Ferrarini, Houssam Akherraz, Longwei Bai, Yves Dusabyinema, Isabelle Rahioui, Pedro Da Silva, Benjamin Gillet, Sandrine Hughes, Cathy I Ramos, Renata C Matos, and François Leulier
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symbiosis ,Lactobacillus ,GCN2 ,Medicine ,Science ,Biology (General) ,QH301-705.5 - Abstract
Symbiotic bacteria interact with their host through symbiotic cues. Here, we took advantage of the mutualism between Drosophila and Lactiplantibacillus plantarum (Lp) to investigate a novel mechanism of host-symbiont interaction. Using chemically defined diets, we found that association with Lp improves the growth of larvae-fed amino acid-imbalanced diets, even though Lp cannot produce the limiting amino acid. We show that in this context Lp supports its host’s growth through a molecular dialogue that requires functional operons encoding ribosomal and transfer RNAs (r/tRNAs) in Lp and the general control nonderepressible 2 (GCN2) kinase in Drosophila’s enterocytes. Our data indicate that Lp’s r/tRNAs are packaged in extracellular vesicles and activate GCN2 in a subset of larval enterocytes, a mechanism necessary to remodel the intestinal transcriptome and ultimately to support anabolic growth. Based on our findings, we propose a novel beneficial molecular dialogue between host and microbes, which relies on a non-canonical role of GCN2 as a mediator of non-nutritional symbiotic cues encoded by r/tRNA operons.
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- 2023
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10. Weevil Carbohydrate Intake Triggers Endosymbiont Proliferation: A Trade-Off between Host Benefit and Endosymbiont Burden
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Elisa Dell’Aglio, Virginie Lacotte, Sergio Peignier, Isabelle Rahioui, Fadéla Benzaoui, Agnès Vallier, Pedro Da Silva, Emmanuel Desouhant, Abdelaziz Heddi, and Rita Rebollo
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coevolution ,endosymbiosis ,species interaction ,symbiosis ,Microbiology ,QR1-502 - Abstract
ABSTRACT Nutritional symbioses between insects and intracellular bacteria (endosymbionts) are a major force of adaptation, allowing animals to colonize nutrient-poor ecological niches. Many beetles feeding on tyrosine-poor substrates rely on a surplus of aromatic amino acids produced by bacterial endosymbionts. This surplus of aromatic amino acids is crucial for the biosynthesis of a thick exoskeleton, the cuticle, which is made of a matrix of chitin with proteins and pigments built from tyrosine-derived molecules, providing an important defensive barrier against biotic and abiotic stress. Other endosymbiont-related advantages for beetles include faster development and improved fecundity. The association between Sitophilus oryzae and the Sodalis pierantonius endosymbiont represents a unique case study among beetles: endosymbionts undergo an exponential proliferation in young adults concomitant with the cuticle tanning, and then they are fully eliminated. While endosymbiont clearance, as well as total endosymbiont titer, are host-controlled processes, the mechanism triggering endosymbiont exponential proliferation remains poorly understood. Here, we show that endosymbiont exponential proliferation relies on host carbohydrate intake, unlike the total endosymbiont titer or the endosymbiont clearance, which are under host genetic control. Remarkably, insect fecundity was preserved, and the cuticle tanning was achieved, even when endosymbiont exponential proliferation was experimentally blocked, except in the context of a severely unbalanced diet. Moreover, a high endosymbiont titer coupled with nutrient shortage dramatically impacted host survival, revealing possible environment-dependent disadvantages for the host, likely due to the high energy cost of exponentially proliferating endosymbionts. IMPORTANCE Beetles thriving on tyrosine-poor diet sources often develop mutualistic associations with endosymbionts able to synthesize aromatic amino acids. This surplus of aromatic amino acids is used to reinforce the insect’s protective cuticle. An exceptional feature of the Sitophilus oryzae/Sodalis pierantonius interaction is the exponential increase in endosymbiotic titer observed in young adult insects, in concomitance with cuticle biosynthesis. Here, we show that host carbohydrate intake triggers endosymbiont exponential proliferation, even in conditions that lead to the detriment of the host survival. In addition, when hosts thrive on a balanced diet, endosymbiont proliferation is dispensable for several host fitness traits. The endosymbiont exponential proliferation is therefore dependent on the nutritional status of the host, and its consequences on host cuticle biosynthesis and survival depend on food quality and availability.
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- 2023
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11. A comparative study revealed hyperspectral imaging as a potential standardized tool for the analysis of cuticle tanning over insect development
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Virginie Lacotte, Elisa Dell’Aglio, Sergio Peignier, Fadéla Benzaoui, Abdelaziz Heddi, Rita Rebollo, and Pedro Da Silva
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Science (General) ,Q1-390 ,Social sciences (General) ,H1-99 - Abstract
Cereal-feeding beetles are a major risk for cereal crop maintenance. Cereal weevils such as Sitophilus oryzae have symbiotic intracellular bacteria that provide essential aromatic amino acid to the host for the biosynthesis of their cuticle building blocks. Their cuticle is an important protective barrier against biotic and abiotic stresses, providing high resistance from insecticides. Quantitative optical methods specialized in insect cuticle analysis exist, but their scope of use and the repeatability of the results remain limited. Here, we investigated the potential of Hyperspectral Imaging (HSI) as a standardized cuticle analysis tool. Based on HSI, we acquired time series of average reflectance profiles from 400 to 1000 nm from symbiotic (with bacteria) and aposymbiotic (without bacteria) cereal weevils S. oryzae exposed to different nutritional stresses. We assessed the phenotypic changes of weevils under different diets throughout their development and demonstrated the agreement of the results between the HSI method and the classically used Red-Green-Blue analysis. Then, we compared the use of both technologies in laboratory conditions and highlighted the assets of HSI to develop a simple, automated, and standardized analysis tool. This is the first study showing the reliability and feasibility of HSI for a standardized analysis of insect cuticle changes.
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- 2023
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12. Discovery of an Insect Neuroactive Helix Ring Peptide from Ant Venom
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Valentine Barassé, Laurence Jouvensal, Guillaume Boy, Arnaud Billet, Steven Ascoët, Benjamin Lefranc, Jérôme Leprince, Alain Dejean, Virginie Lacotte, Isabelle Rahioui, Catherine Sivignon, Karen Gaget, Mélanie Ribeiro Lopes, Federica Calevro, Pedro Da Silva, Karine Loth, Françoise Paquet, Michel Treilhou, Elsa Bonnafé, and Axel Touchard
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ant venoms ,neurotoxins ,Tetramorium bicarinatum ,potassium channel ,helix peptide ,Medicine - Abstract
Ants are among the most abundant terrestrial invertebrate predators on Earth. To overwhelm their prey, they employ several remarkable behavioral, physiological, and biochemical innovations, including an effective paralytic venom. Ant venoms are thus cocktails of toxins finely tuned to disrupt the physiological systems of insect prey. They have received little attention yet hold great promise for the discovery of novel insecticidal molecules. To identify insect-neurotoxins from ant venoms, we screened the paralytic activity on blowflies of nine synthetic peptides previously characterized in the venom of Tetramorium bicarinatum. We selected peptide U11, a 34-amino acid peptide, for further insecticidal, structural, and pharmacological experiments. Insecticidal assays revealed that U11 is one of the most paralytic peptides ever reported from ant venoms against blowflies and is also capable of paralyzing honeybees. An NMR spectroscopy of U11 uncovered a unique scaffold, featuring a compact triangular ring helix structure stabilized by a single disulfide bond. Pharmacological assays using Drosophila S2 cells demonstrated that U11 is not cytotoxic, but suggest that it may modulate potassium conductance, which structural data seem to corroborate and will be confirmed in a future extended pharmacological investigation. The results described in this paper demonstrate that ant venom is a promising reservoir for the discovery of neuroactive insecticidal peptides.
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- 2023
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13. Estimating the effect of a rifampicin resistant tuberculosis diagnosis by the Xpert MTB/RIF assay on two-year mortality
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Elise De Vos, Daniel Westreich, Lesley Scott, Yara Voss de Lima, Wendy Stevens, Cindy Hayes, Pedro da Silva, and Annelies Van Rie
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Public aspects of medicine ,RA1-1270 - Abstract
Studies assessing patient-centred outcomes of novel rifampicin resistant tuberculosis (RR-TB) diagnostics are rare and mostly apply conventional methods which may not adequately address biases. Even though the Xpert MTB/RIF molecular assay was endorsed a decade ago for simultaneous diagnosis of tuberculosis and RR-TB, the impact of the assay on mortality among people with RR-TB has not yet been assessed. We analysed data of an observational prospective cohort study (EXIT-RIF) performed in South Africa. We applied a causal inference approach using inverse odds of sampling weights to rectify survivor bias and selection bias caused by differing screening guidelines. We also adjusted for confounding using a marginal structural model with inverse probability of treatment weights. We estimated the total effect of an RR-TB diagnosis made by the Xpert assay versus the pre-Xpert diagnostic algorithm (entailing a targeted Line Probe Assay (LPA) among TB-confirmed patients) on two-year mortality and we assessed mediation by RR-treatment initiation. Of the 749 patients diagnosed with RR-TB [247 (33%) by the pre-Xpert diagnostic algorithm and 502 (67%) by the Xpert assay], 42.7% died. Of these, 364 (48.6%) patients died in the pre-Xpert group and 200 (39.8%) in the Xpert group. People diagnosed with RR-TB by the Xpert assay had a higher odds of RR-TB treatment initiation compared to those diagnosed by the targeted LPA-based diagnostic process (OR 2.79; 95%CI 2.19–3.56). Receiving an RR-TB diagnosis by Xpert resulted in a 28% reduction in the odds of mortality within 2 years after presentation to the clinic (ORCI 0.72; 95%CI 0.53–0.99). Causal mediation analysis suggests that the higher rate of RR-TB treatment initiation in people diagnosed by the Xpert assay explains the effect of Xpert on 2-year mortality [natural indirect effect odds ratio 0.90 (95%CI 0.85–0.96). By using causal inference methods in combination with high quality observational data, we could demonstrate that the introduction of the Xpert assay caused a 28% reduction in 2-year odds of mortality of RR-TB. This finding highlights the need for advocacy for a worldwide roll-out of rapid molecular tests. Because the effect is mainly caused by increased RR-TB treatment initiation, health care systems should also ensure timely initiation of effective treatment upon an RR-TB diagnosis.
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- 2023
14. Ambulatory and hospitalized patients with suspected and confirmed mpox: an observational cohort study from BrazilResearch in context
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Mayara Secco Torres Silva, Carolina Coutinho, Thiago Silva Torres, Eduardo Peixoto, Ronaldo Ismério, Flavia Lessa, Estevão Portela Nunes, Brenda Hoagland, Amanda Dolores Echeverria Guevara, Matheus Oliveira Bastos, Isabel Cristina Ferreira Tavares, Maria Pia Diniz Ribeiro, Maria Roberta Meneguetti Seravalli Ramos, Hugo Boechat Andrade, Ana Paula Lovetro Santana, Marilia Santini-Oliveira, Juliana Barbosa Santos Netto, Paula Reges, Monica Avelar Magalhães, Leonardo Azevedo Silva Rosadas, Sandro Nazer, Luciane Velasque, Sandra Wagner Cardoso, Edson Elias da Silva, Valdilea Gonçalves Veloso, Mayumi Duarte Wakimoto, Beatriz Grinsztejn, André Miguel Japiassu, Marcel Trepow, Italo Guariz Ferreira, Larissa Villela, Rafael Teixeira Fraga, Mariah Castro de Souza Pires, Rodrigo Otavio da Silva Escada, Leonardo Paiva de Sousa, Gabriela Lisseth Umaña Robleda, Desirée Vieira Santos, Luiz Ricardo Siqueira Camacho, Pedro Amparo, João Victor Jaegger de França, Felipe de Oliveira Heluy Correa, Bruno Ivanovinsky Costa de Sousa, Bernardo Vicari do Valle, João Paulo Bortot Soares, Livia Cristina Fonseca Ferreira, Pedro da Silva Martins, Maira Braga Mesquita, José Ricardo Hildebrant Coutinho, Raissa de Moraes Perlingeiro, Priscila Peixoto de Castro Oliveira, Hugo Perazzo Pedroso Barbosa, André Figueiredo Accetta, Marcelo Cunha, Rosangela Vieira Eiras, Ticiana Martins dos Santos, Wladmyr Davila da Silva, Monique do Vale Silveira, Tania de Souza Brum, Guilherme Amaral Calvet, Rodrigo Caldas Menezes, and Sandro Antônio Pereira
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Mpox ,Outbreaks ,STI ,HIV ,Pre-exposure prophylaxis (PrEP) ,Men who have sex with men ,Public aspects of medicine ,RA1-1270 - Abstract
Summary: Background: By October 30, 2022, 76,871 cases of mpox were reported worldwide, with 20,614 cases in Latin America. This study reports characteristics of a case series of suspected and confirmed mpox cases at a referral infectious diseases center in Rio de Janeiro, Brazil. Methods: This was a single-center, prospective, observational cohort study that enrolled all patients with suspected mpox between June 12 and August 19, 2022. Mpox was confirmed by a PCR test. We compared characteristics of confirmed and non-confirmed cases, and among confirmed cases according to HIV status using distribution tests. Kernel estimation was used for exploratory spatial analysis. Findings: Of 342 individuals with suspected mpox, 208 (60.8%) were confirmed cases. Compared to non-confirmed cases, confirmed cases were more frequent among individuals aged 30–39 years, cisgender men (96.2% vs. 66.4%; p
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- 2023
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15. AVALIAÇÃO DO CONHECIMENTO SOBRE CHEMSEX EM PROFISSIONAIS DE SAÚDE DO DEPARTAMENTO DE MOLÉSTIAS INFECCIOSAS E PARASITÁRIAS DE UM COMPLEXO HOSPITALAR
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Felipe Arthur Faustino Medeiros, Pedro da Silva Campana, and Gabriel Trova Cuba
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Infectious and parasitic diseases ,RC109-216 ,Microbiology ,QR1-502 - Abstract
Introdução: Chemsex é definida como a prática sexual com uso de substâncias psicoativas (SP). Há poucos estudos sobre a prevalência de Chemsex no Brasil, refletindo a precariedade de discussão acerca do tema, muito baseado no modelo de sociedade brasileira, o qual ainda tem o sexo como tabu. O uso de aditivos recreativos durante o sexo pode afetar nas práticas de prevenção à aquisição de infecções sexual transmissíveis (IST), diminuindo, por exemplo, o uso de preservativos e aumentando a exposição dos praticantes à adquirirem tais infecções. A necessidade de se conhecer sobre Chemsex dentro da prática de saúde se dá na urgência de se criar formas de acolher, respeitar e abrir diálogos acerca de formas de prevenção e promoção de saúde para com aquisição de ISTs dentro do atendimento diário. Objetivo: O estudo visou averiguar o conhecimento dos profissionais acerca do tema, acessando conceitos de prevenção e promoção de saúde para com os usuários do nosso serviço. Método: Estudo de coorte transversal, prospectivo, com aplicação de um questionário aplicado pelo REDCap, nos locais de atuação de profissionais do departamento de Moléstias Infecciosas e Parasitárias do Complexo HC-FMUSP. Resultados: Foram avaliados 62 profissionais no total, com prevalência de médicas e médicos (75%), mostrando 93% de respostas afirmativas entre médicos assistentes e 90% entre médicos residentes (p = 0,594) sobre o conhecimento acerca de Chemsex. Na discussão sobre orientação de redução de danos e efeitos no uso de Chemsex, apenas 30% dos profissionais médicos assistentes responderam afirmativamente sobre acreditar conseguir realizar tal orientação, comparado com 14% dos médicos residentes (p = 0,183). Quando comparados profissionais médicos com os demais profissionais da equipe multidisciplinar, obtivemos 23% e 21%, respectivamente (p = 0,610). Sobre o serviço de saúde, 87% dos participantes afirmaram que seus serviços nunca realizaram avaliação direta sobre uso de Chemsex entre seus pacientes. Apenas 29% dos participantes afirmaram ter recebido algum treinamento ou participado de alguma aula/palestra que abordasse sobre Chemsex e os riscos associados à sua prática. Conclusão: O estudo mostrou que há uma paridade entre o conhecimento acerca de Chemsex e as principais substâncias envolvidas nessa prática, porém ainda um conhecimento limitado para orientação de práticas sexuais seguras no contexto de uso de SP e insegurança para orientar redução de danos aos seus pacientes na prática clínica.
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- 2022
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16. HIV Viral Load Testing in the South African Public Health Setting in the Context of Evolving ART Guidelines and Advances in Technology, 2013–2022
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Lucia Hans, Naseem Cassim, Somayya Sarang, Diana Hardie, Silence Ndlovu, W.D. Francois Venter, Pedro Da Silva, and Wendy Stevens
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HIV viral load ,national program ,guidelines ,advances ,technology ,South Africa ,Medicine (General) ,R5-920 - Abstract
HIV viral load (VL) testing plays a key role in the clinical management of HIV as a marker of adherence and antiretroviral efficacy. To date, national and international antiretroviral treatment recommendations have evolved to endorse routine VL testing. South Africa (SA) has recommended routine VL testing since 2004. Progressively, the centralised HIV VL program managed by its National Health Laboratory Service (NHLS) has undergone expansive growth. Retrospective de-identified VL data from 2013 to 2022 were evaluated to review program performance. Test volumes increased from 1,961,720 performed in 2013 to 45,334,864 in 2022. The median total in-laboratory turnaround time (TAT) ranged from 94 h (2015) to 51 h (2022). Implementation of two new assays improved median TATs in all laboratories. Samples of VL greater than 1000 copies/mL declined steadily. Despite initial increases, samples of fewer than 50 copies/mL stagnated at about 70% from 2019 and declined to 68% in 2022. Some variations between assays were observed. Overall, the SA VL program is successful. The scale of the VL program, the largest of its kind in the world by some margin, provides lessons for future public health programs dependent on laboratories for patient outcome and program performance monitoring.
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- 2023
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17. Detection of Aphids on Hyperspectral Images Using One-Class SVM and Laplacian of Gaussians
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Sergio Peignier, Virginie Lacotte, Marie-Gabrielle Duport, Patrice Baa-Puyoulet, Jean-Christophe Simon, Federica Calevro, Abdelaziz Heddi, and Pedro da Silva
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hyperspectral images ,one-class SVM ,aphids detection ,Science - Abstract
Aphids cause severe damage to agricultural crops, resulting in significant economic losses, and an increased use of pesticides with decreased efficiency. Monitoring aphid infestations through regular field surveys is time-consuming and does not always provide an accurate spatiotemporal representation of the distribution of pests. Therefore, an automated, non-destructive method to detect and evaluate aphid infestation would be beneficial for targeted treatments. In this study, we present a machine learning model to identify and quantify aphids, localizing their spatial distribution over leaves, using a One-Class Support Vector Machine and Laplacian of Gaussians blob detection. To train this model, we built the first large database of aphids’ hyperspectral images, which were captured in a controlled laboratory environment. This database contains more than 160 images of three aphid lines, distinctive in color, shape, and developmental stages, and are displayed laying on leaves or neutral backgrounds. This system exhibits high-quality validation scores, with a Precision of 0.97, a Recall of 0.91, an F1 score of 0.94, and an AUPR score of 0.98. Moreover, when assessing this method on new and challenging images, we did not observe any false negatives (and only a few false positives). Our results suggest that a machine learning model of this caliber could be a promising tool to detect aphids for targeted treatments in the field.
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- 2023
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18. Pediatric tuberculosis in the metropolitan area of Rio de Janeiro
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Anna Cristina C. Carvalho, Pedro da Silva Martins, Claudete Aparecida Araújo Cardoso, Ana Lúcia Miceli, Terezinha Martire, Maria de Fátima B. Pombo Sant'Anna, Christiane Mello Schmidt, Luiza Martins Vieira, Selma Maria de Azevedo Sias, Ana Paula Quintanilha, Ana Paula Barbosa, Adriana da Silva Rezende Moreira, Carla Fernandes dos Santos Lara, Lorrayne Isidoro-Gonçalves, Rafaela Baroni Aurilio, Suzana Aparecida Greggi de Alcantara, André Luis Bezerra, Laura Saderi, Giovanni Sotgiu, Giovanni Battista Migliori, Afrânio L. Kritski, and Clemax Couto Sant’Anna
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Infectious and parasitic diseases ,RC109-216 - Abstract
Aim: To evaluate the clinical characteristics, diagnostic approach, and treatment outcomes of tuberculosis (TB) in children living in a high-burden metropolitan area. Methods: This was a retrospective study, based on a medical chart review, involving children under 15 years old treated for TB between 2007 and 2016, in four primary health units (PHU) and three reference centers (RC) in five cities of Rio de Janeiro metropolitan area. Factors associated with TB treatment setting, microbiological diagnosis, and treatment outcomes were evaluated. Results: A total of 544 children were enrolled; 71% were treated in PHU, 36% were under 5 years old, and 72% had pulmonary TB (PTB). The HIV prevalence was 10% (31/322). Fifty-three percent had at least one microbiological test for TB, 68% of them (196/287) had TB confirmed. Among 222 children with previous TB contact, information on LTBI was available for 78 (35%), and only 17% (13/78) were treated. Extrapulmonary TB (56% vs 32%), microbiologically confirmed TB (77% vs 60%), and HIV positivity (18.5% vs 4.0%) were significantly more frequent in RC. Treatment in RC (odds ratio (OR) 3.08, 95% confidence interval (CI) 1.74–5.44) and PTB (OR 2.47, 95% CI 1.34–4.56) were independently associated with a microbiological diagnosis of TB. The treatment success rate was 85%. In the logistic regression analysis, HIV-infected children had a 2.5-fold higher risk of an unfavorable outcome (OR 2.53, 95% CI 1.0–6.38; p = 0.05). Conclusions: Opportunities for TB prevention and early TB treatment are missed due to suboptimal close contact screening. Microbiological diagnosis of TB and drug susceptibility testing in children should be made available through more sensitive and accessible tests.
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- 2020
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19. Continuous quality monitoring in the field: an evaluation of the performance of the Fio Deki Reader™ for rapid HIV testing in South Africa
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Lara Noble, Lesley Scott, Lynsey Stewart-Isherwood, Seponono John Molifi, Ian Sanne, Pedro Da Silva, and Wendy Stevens
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Automated rapid strip reader ,Continuous quality monitoring ,HIV ,Rapid diagnostic test ,Deki reader ,Infectious and parasitic diseases ,RC109-216 - Abstract
Abstract Background Rapid diagnostic tests (RDTs) are a cornerstone of HIV diagnosis and rely on good quality processing and interpretation, particularly in the era of test and treat. The Deki Reader (Fio Corporation®, Toronto, Ontario, Canada) is a portable device designed specifically for analysing RDTs and was selected for evaluation in South Africa in the context of HIV RDT analysis. Methods This study consisted of a laboratory evaluation and two-part field evaluation of the Deki Reader v100, covering two RDT testing algorithms, and an evaluation of the continuous quality monitoring through the Fionet™ web portal. Based on user feedback from the field evaluation, the device underwent hardware and software redesign, and the Deki Reader v200 was evaluated in the laboratory. Ethics approval for this evaluation was obtained from the University of the Witwatersrand Human Research Ethics Committee: M150160. Results The intra- and inter-device laboratory precision of the Deki Reader v100 were 98.3 and 99.2% respectively, and 99.3 and 100% for the Deki Reader v200. The laboratory concordances compared to standard-of-care reporting were 99.5 and 98.0% for the two respective models, while sensitivity and specificity were 99.5 and 99.4% for the Deki Reader V100 and 100 and 93.1% for the Deki Reader V200 respectively. Screening and confirmatory concordances in the field were 99.3 and 96.5% under algorithm 1 and 99.7 and 100% under algorithm 2. Sensitivity and specificity for the field evaluation were 99.8 and 97.7%. Overall robustness of the device was acceptable and continuous quality monitoring through Fionet™ was feasible. Conclusions The Deki Reader provides an option for improved and reliable quality assessment for rapid diagnosis of HIV using RDTs to enhance the quality of healthcare at the point-of-care. However, the introduction of new RDTs and modification of current algorithms necessitates ongoing and agile RDT reader adjustments, which will require cost modelling to ensure sustainability of devices implemented into national HIV programs.
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- 2020
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20. ESPIROQUETOSE INTESTINAL COMO MANIFESTAÇÃO DE SÍFILIS EM PACIENTE VIVENDO COM HIV
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Felipe Arthur Faustino de Medeiros, Vitor Falcão de Oliveira, Julia Ferreira Mari, Lara Silva Pereira Guimarães, Juliana Cavadas Teixeira, and Pedro da Silva Campana
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Infectious and parasitic diseases ,RC109-216 ,Microbiology ,QR1-502 - Abstract
Homem cisgênero, 43 anos, vivendo com HIV desde 2018, em uso de Tenofovir 300 mg + Lamivudina 300 mg + Dolutegravir 50 mg desde 2019, carga viral indetectável, com contagem de LTCD4+ de 1268 células, vem com quadro de hematoquezia intermitente, associada a evacuação pastosa com muco, de evolução há um mês, não acompanhada de febre ou perda de peso. Realizada colonoscopia diagnóstica, sendo visualizadas lesões ulceradas com fundo de fibrina, não sangrantes, em todo o intestino grosso, sendo realizadas biópsias, com anátomo-patológico evidenciando espiroquetose intestinal colônica (EIC), com presença de espiroquetas filamentosas densamente compactadas na superfície do intestino grosso. Em exames laboratoriais, paciente com VDRL 1/32, sendo o anterior ½, interpretado como cicatriz sorológica após tratamento de Neurossífilis há 04 anos. Paciente foi tratado com Penicilina G Benzatina 7.200.000 UI, divididas em três tomadas, com melhora completa dos sintomas após início do tratamento. A espiroquetose intestinal causada pelo Treponema pallidum, agente etiológico da Sífilis, é uma apresentação incomum e pouco descrita na literatura da doença. Na descrição original da patologia, vemos espiroquetose intestinal humana caracterizada pela presença de espiroquetas na superfície luminal da mucosa do intestino grosso, sendo usualmente causada por um grupo heterogêneo de organismos relacionados, principalmente Brachyspira aalborgi e Brachyspira pilosicoli, que são geneticamente não relacionados ao Treponema pallidum. A apresentação clínica é espectral, sendo desde assintomática até quadros de diarréia crônica persistente, constipação, dor abdominal, sangue nas fezes, vômitos ou náuseas, ou muco nas fezes, ou até mesmo quadros que podem mimetizar apendicite aguda. Ademais, podem apresentar abscessos ou úlceras na macroscopia devido à reação inflamatória à presença das espiroquetas na mucosa colônica. Segundo estudos, as pessoas que vivem com HIV têm uma maior chance de apresentarem EIC em comparação com os casos HIV-negativos, e não está correlacionada com a carga viral. O diagnóstico direto consiste na visualização de espiroquetas na mucosa intestinal, e o indireto pode ser feito com exames treponêmicos e não-treponêmicos séricos, em comparação com anteriores do paciente. Identificada como uma manifestação de visceralização da Sífilis mas também como uma manifestação de Sífilis secundária, o tratamento pode variar entre 2.4 a 7.2 milhões de unidades de Penicilina G Benzatina.
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- 2022
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21. FENÔMENO DE LÚCIO: UMA MANIFESTAÇÃO GRAVE DE UMA DOENÇA MILENAR
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Pedro da Silva Martins, Maíra Braga Mesquita, Natália Serra de Sousa e Silva, Ariane Gomes Paixão, Andréa D'avila Freitas, Marcelo Luiz Carvalho Gonçalves, and Cássio Porto Ferreira
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Infectious and parasitic diseases ,RC109-216 ,Microbiology ,QR1-502 - Abstract
A Hanseníase é uma doença negligenciada com alto estigma e carga em países em desenvolvimento. Infecção crônica, granulomatosa, causada pelo M. leprae que afeta principalmente a pele e nervos periféricos. O Fenômeno de Lúcio (FL) é uma manifestação incomum com graves lesões cutâneas necróticas em pacientes com Hanseníase Lepromatosa. Dentre os fatores precipitantes, destacam-se infecções, uso de drogas e gravidez. JAFS, 17 anos, Nova Iguaçu, RJ, é admitida com lesões disseminadas, recebendo antibióticos sob suspeita de sepse cutânea. História pregressa de abortamento de 1º trimestre há 2 meses da internação; e Hanseníase com Poliquimioterapia (PQT-MB) por 1 ano com Rifampicina (RMP), Clofazimina (CFZ) e Dapsona. É transferida para serviço de referência após 7 dias, mantendo febre, taquicardia e astenia. Ao exame: regular estado, desidratada, com máculas hipercrômicas e purpúricas, placas eritematosas, bolhas serohemáticas e ulcerações necróticas nos membros, orelhas, nariz, palmas e plantas. Artrite do punho e 1º quirodáctilo esquerdos, além de amiotrofias, dor e espessamento dos nervos ulnares, parestesias em bota e em luva, bilaterais, mas assimétricas. Laboratório: Anemia (Hb 7.2 g/dL), trombocitose (624.000), leucocitose (28.040/mm3-0/0/3/5/17/59/12/4), e PCR elevada (29 mg/dL). Sorologias para HIV, Hepatites e Sífilis, hemoculturas para bactérias, fungos, e teste de gravidez foram negativos. Baciloscopia: BAAR e globias em todos os sítios (Índice Baciloscópico: 2.5+) e no aspirado das bolhas. A histopatologia da pele demonstrou inflamação superficial e profunda, perivascular, dermatite granulomatosa perianexial e depósitos fibrinoides vasculares. Com os achados clínicos, histopatológicos e baciloscópicos, foi feito o diagnóstico de Hanseníase Borderline-Lepromatosa em estado reacional - Fenômeno de Lúcio. Recebeu pulsoterapia com metilprednisolona por 3 dias, reduzindo as áreas hipercrômicas e maculares e resolvendo a febre, taquicardia e artrite. A PQT-MB foi reintroduzida com RMP, CFZ, Ofloxacino, Prednisona e Pentoxifilina. Teve alta hospitalar com acompanhamento mensal ambulatorial, com resolução das lesões após desbridamento cirúrgico do material necrótico em 3 meses de seguimento. O FL é raro e potencialmente fatal pela extensão e gravidade das lesões cutâneas, favorecendo complicações discrásicas ou infecciosas. A gravidez é descrita como deflagradora ou exacerbadora de quadros de Hanseníase devido às alterações hormonais e imunológicas.
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- 2022
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22. AVALIAÇÃO DA APLICABILIDADE DA TELEMEDICINA EM UM CENTRO DE REFERÊNCIA PARA IMUNOBIOLÓGICOS ESPECIAIS NO CONTEXTO DE PANDEMIA PELO SARS-COV-2
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Luciana Gomes Pedro Brandão, Marcellus Dias da Costa, Pedro da Silva Martins, Margareth Catoia Varela, Daniele Fernandes de Aguiar, Sergio Carlos Assis de Jesus Junior, Ananza Tainá da Silva Santos, Flavio de Carvalho, Diogo Vicente Bittencourt Sacramento Dias, and Leandro dos Santos da Silva
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Infectious and parasitic diseases ,RC109-216 ,Microbiology ,QR1-502 - Abstract
A pandemia causada pelo SARS-CoV-2 mudou de forma abrupta toda a dinâmica da assistência básica de saúde, havendo a necessidade de adaptações dos serviços considerados essenciais. O objetivo desse trabalho é avaliar a aplicabilidade e o impacto da telemedicina em um Centro de Referência para Imunobiológicos Especiais (CRIE). Métodos Foram incluídos pacientes com 18 anos ou mais de idade que, após leitura e assinatura do TCLE eletrônico, completaram formulário de solicitação de consulta online com o upload do encaminhamento para o CRIE. Após avaliação de elegibilidade, a confirmação do agendamento é enviada por e-mail com o link e orientações para o acesso à consulta virtual. A consulta entre médico e paciente acontece com hora marcada em uma sala virtual privada por meio da Rede Universitária de Telemedicina (RUTE). As fichas para registro das informações foram construídas utilizando o REDCap. Resultados De abril a setembro/2021, foram atendidos 410 pacientes por telemedicina, sendo 90% para programação vacinal, 4,4% eventos adversos pós-vacinais, 5,1% para orientações e 0,5% para interconsulta entre profissionais de saúde. A idade média dos pacientes foi de 54,8 anos, 63,2% eram do sexo feminino, 31% tinham nível superior ou mais de escolaridade, 29,9% residiam fora do Município do RJ. As indicações mais frequentes para o encaminhamento ao CRIE foram: nefropatia crônica (n 75), pneumopatia (n 69), doença autoimune (n 43), cardiopatia (n 40) e diabetes mellitus (n 35). Foram prescritas por mais de 1.700 vacinas por este canal, sendo as mais frequentes: pneumo 23 (n 344), pneumo 13 (n 328), dT (231) e meningo C (197). Do total dos participantes que responderam ao questionário de satisfação (n 319), 99,7% dos participantes recomendariam o serviço para outras pessoas. Conclusões O CRIE é a unidade do Programa Nacional de Imunização que atende indivíduos que necessitam receber imunobiológicos especiais. A centralização do atendimento no CRIE permite um maior controle do uso desses imunobiológicos que, em geral, são de maior custo e/ou menor disponibilidade no mercado; entretanto dificulta o acesso da população às vacinas especiais. Nos primeiros meses da pandemia pelo SARS-CoV-2, houve uma redução significativa do número de atendimentos no CRIE. A telemedicina se mostrou uma ferramenta útil para o atendimento no CRIE e com boa aceitação pelos usuários, com potencial de facilitar o acesso e aumentar o alcance do atendimento do CRIE.
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- 2022
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23. Residues of Legume AG41 Peptide Crucial to Its Bio-Insecticidal Activity
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Fatima Diya, Laurence Jouvensal, Isabelle Rahioui, Karine Loth, Catherine Sivignon, Lamis Karaki, Linda Kfoury, Francine Rizk, and Pedro Da Silva
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peptide 3D structure ,knottin peptide ,bio-insecticidal peptide ,structure function relationships ,legume plant ,Microbiology ,QR1-502 - Abstract
Currently, crop protection relies heavily on chemical treatments, which ultimately leads to environmental contamination and pest resistance. Societal and public policy considerations urge the need for new eco-friendly solutions. In this perspective, biopesticides are effective alternatives to chemical insecticides for the control of various insect pests. Legumes contain numerous insecticidal proteins aimed at protecting their high nitrogen content from animal/insect predation. Investigating one such protein family at genome scale, we discovered a unique diversity of the albumin 1 family in the (model) barrel medic genome. Only some members retained very high insecticidal activity. We uncovered that AG41 peptide from the alfalfa roots displays an outstanding insecticidal activity against several pests such as aphids and weevils. Here we report the 3D structure and activity of AG41 peptide. Significant insights into the structural/functional relationships explained AG41 high insecticidal activity. Such observations pave the way for the development of bio-insecticides, with AG41 peptide as the lead compound.
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- 2023
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24. Cytotype Affects the Capability of the Whitefly Bemisia tabaci MED Species To Feed and Oviposit on an Unfavorable Host Plant
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Sylvain Benhamou, Isabelle Rahioui, Hélène Henri, Hubert Charles, Pedro Da Silva, Abdelaziz Heddi, Fabrice Vavre, Emmanuel Desouhant, Federica Calevro, and Laurence Mouton
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cytotype ,symbionts ,plant utilization ,Bemisia tabaci ,Microbiology ,QR1-502 - Abstract
ABSTRACT The acquisition of nutritional obligate primary endosymbionts (P-symbionts) allowed phloemo-phageous insects to feed on plant sap and thus colonize novel ecological niches. P-symbionts often coexist with facultative secondary endosymbionts (S-symbionts), which may also influence their hosts’ niche utilization ability. The whitefly Bemisia tabaci is a highly diversified species complex harboring, in addition to the P-symbiont “Candidatus Portiera aleyrodidarum,” seven S-symbionts whose roles remain poorly understood. Here, we compare the phenotypic and metabolic responses of three B. tabaci lines differing in their S-symbiont community, reared on three different host plants, hibiscus, tobacco, or lantana, and address whether and how S-symbionts influence insect capacity to feed and produce offspring on those plants. We first show that hibiscus, tobacco, and lantana differ in their free amino acid composition. Insects’ performance, as well as free amino acid profile and symbiotic load, were shown to be plant dependent, suggesting a critical role for the plant nutritional properties. Insect fecundity was significantly lower on lantana, indicating that it is the least favorable plant. Remarkably, insects reared on this plant show a specific amino acid profile and a higher symbiont density compared to the two other plants. In addition, this plant was the only one for which fecundity differences were observed between lines. Using genetically homogeneous hybrids, we demonstrate that cytotype (mitochondria and symbionts), and not genotype, is a major determinant of females’ fecundity and amino acid profile on lantana. As cytotypes differ in their S-symbiont community, we propose that these symbionts may mediate their hosts’ suitable plant range. IMPORTANCE Microbial symbionts are universal in eukaryotes, and it is now recognized that symbiotic associations represent major evolutionary driving forces. However, the extent to which symbionts contribute to their hosts’ ecological adaptation and subsequent diversification is far from being fully elucidated. The whitefly Bemisia tabaci is a sap feeder associated with multiple coinfecting intracellular facultative symbionts. Here, we show that plant species simultaneously affect whiteflies’ performance, amino acid profile, and symbiotic density, which could be partially explained by differences in plant nutritional properties. We also demonstrate that, on lantana, the least favorable plant used in our study, whiteflies’ performance is determined by their cytotype. We propose that the host plant utilization in B. tabaci is influenced by its facultative symbiont community composition, possibly through its impact on the host dietary requirements. Altogether, our data provide new insights into the impact of intracellular microorganisms on their animal hosts’ ecological niche range and diversification.
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- 2021
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25. Rapid Evaluation of the Xpert® Xpress CoV-2 plus and Xpert® Xpress CoV-2/Flu/RSV plus Tests
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Lara Dominique Noble, Lesley Erica Scott, Riffat Munir, Mignon Du Plessis, Kim Steegen, Lucia Hans, Puleng Marokane, Pedro Da Silva, and Wendy Susan Stevens
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SARS-CoV-2 ,respiratory tests ,Xpert® Xpress CoV-2 plus ,Xpert® ,Xpress CoV-2/Flu/RSV plus ,diagnostic evaluation ,Medicine (General) ,R5-920 - Abstract
The Xpert® Xpress SARS-CoV-2 and Xpert® Xpress SARS-CoV-2/Flu/RSV tests were rapidly developed and widely used during the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pandemic. In response to emerging genetic variability, a new SARS-CoV-2 target (RNA-dependent RNA-polymerase) has been added to both tests: Xpert® Xpress CoV-2 plus and Xpert® Xpress CoV-2/Flu/RSV plus test. A rapid evaluation of both tests was performed in South Africa, using residual respiratory specimens. Residual respiratory specimens (n = 125) were used to evaluate the Xpert® Xpress CoV-2 plus test and included 50 genotyped specimens. The Xpert® Xpress CoV-2/Flu/RSV plus test was assessed using 45 genotyped SARS-CoV-2 specimens, 10 influenza A, 10 influenza B and 20 respiratory syncytial virus specimens. Results were compared to in-country standard-of-care tests. Genotyped specimens tested the performance of the test under pressure from circulating SARS-CoV-2 variants of concern. Reference material was included to assess the test limits and linearity. The Xpert® Xpress CoV-2 plus test performance compared to reference results across residual respiratory specimens was good (positive percentage agreement (PPA) = 95.2%, negative percentage agreement (NPA) = 95.0%) The Xpert® Xpress CoV-2/Flu/RSV plus test showed good performance across all residual respiratory specimens (PPA = 100%, NPA = 98.3%). All genotyped variants of concern were detected by both tests. The Xpert® Xpress CoV-2 plus and Xpert® Xpress CoV-2/Flu/RSV plus tests can be used to diagnose SARS-CoV-2, and to diagnose and differentiate SARS-CoV-2, influenza A, influenza B and respiratory syncytial virus, respectively. The NPA was lower than the recommended 99%, but was influenced by the low number of negative specimens tested. The variants of concern assessed did not affect test performance. It is recommended that sites perform their own assessments compared to in-country standard-of-care tests.
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- 2022
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26. Aphid BCR4 Structure and Activity Uncover a New Defensin Peptide Superfamily
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Karine Loth, Nicolas Parisot, Françoise Paquet, Hugo Terrasson, Catherine Sivignon, Isabelle Rahioui, Mélanie Ribeiro Lopes, Karen Gaget, Gabrielle Duport, Agnès F. Delmas, Vincent Aucagne, Abdelaziz Heddi, Federica Calevro, and Pedro da Silva
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aphid BCR ,3D structure ,defensin peptide ,bioinsecticidal peptide ,symbiosis ,Biology (General) ,QH301-705.5 ,Chemistry ,QD1-999 - Abstract
Aphids (Hemiptera: Aphidoidea) are among the most detrimental insects for agricultural plants, and their management is a great challenge in agronomical research. A new class of proteins, called Bacteriocyte-specific Cysteine-Rich (BCR) peptides, provides an alternative to chemical insecticides for pest control. BCRs were initially identified in the pea aphid Acyrthosiphon pisum. They are small disulfide bond-rich proteins expressed exclusively in aphid bacteriocytes, the insect cells that host intracellular symbiotic bacteria. Here, we show that one of the A. pisum BCRs, BCR4, displays prominent insecticidal activity against the pea aphid, impairing insect survival and nymphal growth, providing evidence for its potential use as a new biopesticide. Our comparative genomics and phylogenetic analyses indicate that BCRs are restricted to the aphid lineage. The 3D structure of BCR4 reveals that this peptide belongs to an as-yet-unknown structural class of peptides and defines a new superfamily of defensins.
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- 2022
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27. Spatial–Spectral Analysis of Hyperspectral Images Reveals Early Detection of Downy Mildew on Grapevine Leaves
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Virginie Lacotte, Sergio Peignier, Marc Raynal, Isabelle Demeaux, François Delmotte, and Pedro da Silva
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bioinformatics ,hyperspectral imaging ,Plasmopara viticola ,grapevine ,disease management ,early detection ,Biology (General) ,QH301-705.5 ,Chemistry ,QD1-999 - Abstract
Downy mildew is a highly destructive disease of grapevine. Currently, monitoring for its symptoms is time-consuming and requires specialist staff. Therefore, an automated non-destructive method to detect the pathogen before the visible symptoms appear would be beneficial for early targeted treatments. The aim of this study was to detect the disease early in a controlled environment, and to monitor the disease severity evolution in time and space. We used a hyperspectral image database following the development from 0 to 9 days post inoculation (dpi) of three strains of Plasmopara viticola inoculated on grapevine leaves and developed an automatic detection tool based on a Support Vector Machine (SVM) classifier. The SVM obtained promising validation average accuracy scores of 0.96, a test accuracy score of 0.99, and it did not output false positives on the control leaves and detected downy mildew at 2 dpi, 2 days before the clear onset of visual symptoms at 4 dpi. Moreover, the disease area detected over time was higher than that when visually assessed, providing a better evaluation of disease severity. To our knowledge, this is the first study using hyperspectral imaging to automatically detect and show the spatial distribution of downy mildew on grapevine leaves early over time.
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- 2022
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28. Accounting for Sources of Information in Trade Fairs: Evidence from Portuguese Exhibitors
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Pedro da Silva, José Santos, and Victor Moutinho
- Subjects
trade fairs ,information sources ,information exchange ,exhibitors' perspective ,Business ,HF5001-6182 - Abstract
Trade fairs are important sources of information for decision making in marketing management. Currently, trade fairs are places where participants share useful data and information, while creating relationships between customers (visitors) and suppliers (exhibitors). However, only a limited number of studies have focused on the identification of the sources of information that exhibitors can provide for marketing managers at trade fairs. This study examines the importance of the different types of information resources that can be delivered by exhibitors to managers in order to transfer information about product and market trends. Based on the data from a survey of 172 Portuguese executives from different industries, the theoretical hypotheses are tested, using CFA (Confirmatory Factor Analysis). Consistent with our hypotheses, the results show that Direct Marketing techniques, such as face-to-face contacts and product/service demonstrations, are often used by exhibitors. Information in digital formats and demonstration in digital equipment (Digital Marketing) are also used in trade fairs to display information to potential customers. Additionally, the organization of parallel events (Event Marketing) during a trade fair supplements the package of activities developed by exhibitors to transmit and capture information for their companies. These results provide certain support for the importance of trade fairs in view of being a rich source of market information about not only new technological developments of products, but also major strengths and weaknesses of competitors, and future market trends, among other types of information needed for the marketing planning.
- Published
- 2021
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29. Analysis and improvement of a semi-Lagrangian exponential scheme for the shallow-water equations on the rotating sphere
- Author
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Steinstraesser, João Guilherme Caldas, Schreiber, Martin, and Peixoto, Pedro da Silva
- Subjects
Mathematics - Numerical Analysis ,65M12, 65M22, 76U60 ,G.1.8 ,G.1.10 - Abstract
In this work, we study and extend a class of semi-Lagrangian exponential methods, which combine exponential time integration techniques, suitable for integrating stiff linear terms, with a semi-Lagrangian treatment of nonlinear advection terms. Partial differential equations involving both processes arise for instance in atmospheric circulation models. Through a truncation error analysis, we show that previously formulated semi-Lagrangian exponential schemes are limited to first-order accuracy due to the discretization of the linear term; we then formulate a new discretization leading to second-order accuracy. Also, a detailed stability study is conducted to compare several Eulerian and semi-Lagrangian exponential schemes, as well as a well-established semi-Lagrangian semi-implicit method, which is used in operational atmospheric models. Numerical simulations of the shallow-water equations on the rotating sphere are performed to assess the orders of convergence, stability properties, and computational cost of each method. The proposed second-order semi-Lagrangian exponential method was shown to be more stable and accurate than the previously formulated schemes of the same class at the expense of larger wall-clock times; however, the method is more stable and has a similar cost compared to the well-established semi-Lagrangian semi-implicit method; therefore, it is a competitive candidate for potential operational applications in atmospheric circulation modeling., Comment: 35 pages, 10 figures
- Published
- 2024
30. Diagnosis of pulmonary tuberculosis in children and adolescents: comparison of two versions of the Brazilian Ministry of Health scoring system
- Author
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Roberta Feijó Carvalho, Anna Cristina Calçada Carvalho, Luis Guillermo Coca Velarde, Andrea Maciel de Oliveira Rossoni, Rafaela Baroni Aurilio, Selma Maria de Azevedo Sias, Christiane Mello Schmidt, Adriana da Silva Rezende Moreira, Pedro da Silva Martins, Lorrayne Isidoro Gonçalves, Terezinha Miceli Martire, Ana Paula Ferreira Barbosa, Ana Paula Quintanilha dos Santos, Roberta Maia de Castro Romanelli, Maria das Graças Rodrigues de Oliveira, Lilian Martins Oliveira Diniz, Andrea Lucchesi de Carvalho, Sheila Cunha Lucena, Maria Letícia Santos Cruz, Mariza Curto Saavedra, Tony Tannous Tahan, Cristina de Oliveira Rodrigues, Afrânio Lineu Kritski, Clemax Couto Sant’Anna, Claudete Aparecida Araújo Cardoso, and Maria de Fátima Bazhuni Pombo Sant’Anna
- Subjects
Pulmonary tuberculosis ,Children ,Diagnosis ,Clinical protocols ,Tuberculin skin test ,Tuberculosis scoring system ,Arctic medicine. Tropical medicine ,RC955-962 ,Infectious and parasitic diseases ,RC109-216 - Abstract
ABSTRACT The aim of this study was to evaluate the concordance between two versions of the scoring system (2011 and 2019), recommended by the Brazilian Ministry of Health, for the diagnosis of pulmonary tuberculosis (PTB) in children and adolescents. A retrospective descriptive study was performed to assess the medical records of children and adolescents with PTB, in TB units from Brazilian cities located in Rio de Janeiro, Minas Gerais, and Parana States, from January 1 st , 2004, to December 1 st , 2018. Patients aged 0 to 18 years old with a diagnosis of PTB were included. The comparison between the two scoring systems showed a moderate concordance according to the κ coefficient value = 0.625. Fourteen patients showed a reduction in the TB score, going from 30 points in the 2011, to 25 points or less in the 2019 one. Seventy one percent of these 14 patients had radiological changes suggestive of PTB and 86% had tuberculin skin tests greater than 10 mm. The study concluded that a moderate agreement was observed between the 2011 and 2019 scoring systems, with an increase in the number of patients scoring 25 points or less in 2019, which can eventually hinder the diagnosis of PTB.
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- 2020
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31. The relationship between clinics and the venom of the causative Amazon pit viper (Bothrops atrox).
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Ana Maria Moura-da-Silva, Jorge Carlos Contreras-Bernal, Sarah Natalie Cirilo Gimenes, Luciana Aparecida Freitas-de-Sousa, José Antonio Portes-Junior, Pedro da Silva Peixoto, Leo Kei Iwai, Valéria Mourão de Moura, Pedro Ferreira Bisneto, Marcus Lacerda, Iran Mendonça da Silva, Luiz Carlos de Lima Ferreira, Sâmella Silva de Oliveira, Fan Hui Wen, Jacqueline de Almeida Gonçalves Sachett, and Wuelton M Monteiro
- Subjects
Arctic medicine. Tropical medicine ,RC955-962 ,Public aspects of medicine ,RA1-1270 - Abstract
Snake venoms are complex mixtures of proteins with toxic activities, with many distinct isoforms, affecting different physiological targets, comprised in a few protein families. It is currently accepted that this diversity in venom composition is an adaptive advantage for venom efficacy on a wide range of prey. However, on the other side, variability on isoforms expression has implications in the clinics of human victims of snakebites and in the efficacy of antivenoms. B. atrox snakes are responsible for most of the human accidents in Brazilian Amazon and the type and abundance of protein families on their venoms present individual variability. Thus, in this study we attempted to correlate the individual venom proteome of the snake brought to the hospital by the patient seeking for medical assistance with the clinical signs observed in the same patient. Individual variability was confirmed in venoms of the 14 snakes selected for the study. The abundance of each protein family was quite similar among the venom samples, while the isoforms composition was highly variable. Considering the protein families, the SVMP group presented the best correlation with bleeding disorders and edema. Considering individual isoforms, some isoforms of venom metalloproteinase (SVMP), C-type lectin-like toxins (CTL) and snake venom serine proteinases (SVSP) presented expression levels that with statistically significant positive correlation to signs and symptoms presented by the patients as bleeding disorders, edema, ecchymosis and blister formation. However, some unexpected data were also observed as the correlation between a CTL, CRISP or LAAO isoforms with blister formation, still to be confirmed with a larger number of samples. Although this is still a small number of patient samples, we were able to indicate that venom composition modulates clinical manifestations of snakebites, to confirm at the bedside the prominent role of SVMPs and to include new possible toxin candidates for the development of toxin inhibitors or to improve antivenom selectiveness, important actions for the next generation treatments of snakebites.
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- 2020
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32. Metabolic Cooperation among Commensal Bacteria Supports Drosophila Juvenile Growth under Nutritional Stress
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Jessika Consuegra, Théodore Grenier, Houssam Akherraz, Isabelle Rahioui, Hugo Gervais, Pedro da Silva, and François Leulier
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Biological Sciences ,Microbiology ,Microbiome ,Science - Abstract
Summary: The gut microbiota shapes animal growth trajectory in stressful nutritional environments, but the molecular mechanisms behind such physiological benefits remain poorly understood. The gut microbiota is mostly composed of bacteria, which construct metabolic networks among themselves and with the host. Until now, how the metabolic activities of the microbiota contribute to host juvenile growth remains unknown. Here, using Drosophila as a host model, we report that two of its major bacterial partners, Lactobacillus plantarum and Acetobacter pomorum, engage in a beneficial metabolic dialogue that boosts host juvenile growth despite nutritional stress. We pinpoint that lactate, produced by L. plantarum, is utilized by A. pomorum as an additional carbon source, and A. pomorum provides essential amino acids and vitamins to L. plantarum. Such bacterial cross-feeding provisions a set of anabolic metabolites to the host, which may foster host systemic growth despite poor nutrition.
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- 2020
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33. Drosophila-associated bacteria differentially shape the nutritional requirements of their host during juvenile growth.
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Jessika Consuegra, Théodore Grenier, Patrice Baa-Puyoulet, Isabelle Rahioui, Houssam Akherraz, Hugo Gervais, Nicolas Parisot, Pedro da Silva, Hubert Charles, Federica Calevro, and François Leulier
- Subjects
Biology (General) ,QH301-705.5 - Abstract
The interplay between nutrition and the microbial communities colonizing the gastrointestinal tract (i.e., gut microbiota) determines juvenile growth trajectory. Nutritional deficiencies trigger developmental delays, and an immature gut microbiota is a hallmark of pathologies related to childhood undernutrition. However, how host-associated bacteria modulate the impact of nutrition on juvenile growth remains elusive. Here, using gnotobiotic Drosophila melanogaster larvae independently associated with Acetobacter pomorumWJL (ApWJL) and Lactobacillus plantarumNC8 (LpNC8), 2 model Drosophila-associated bacteria, we performed a large-scale, systematic nutritional screen based on larval growth in 40 different and precisely controlled nutritional environments. We combined these results with genome-based metabolic network reconstruction to define the biosynthetic capacities of Drosophila germ-free (GF) larvae and its 2 bacterial partners. We first established that ApWJL and LpNC8 differentially fulfill the nutritional requirements of the ex-GF larvae and parsed such difference down to individual amino acids, vitamins, other micronutrients, and trace metals. We found that Drosophila-associated bacteria not only fortify the host's diet with essential nutrients but, in specific instances, functionally compensate for host auxotrophies by either providing a metabolic intermediate or nutrient derivative to the host or by uptaking, concentrating, and delivering contaminant traces of micronutrients. Our systematic work reveals that beyond the molecular dialogue engaged between the host and its bacterial partners, Drosophila and its associated bacteria establish an integrated nutritional network relying on nutrient provision and utilization.
- Published
- 2020
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34. Rhodococcus hoagii bloodstream infection in an allogeneic hematopoietic stem cell transplantation patient: Case report and review of literature
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Pedro da Silva Campana, Lorena Zaine Matos Martinho, Marjorie Vieira Batista, Hermes Higashino, Camila Rizek, Flavia Rossi, Fernando Nivaldo Oliveira, Vanderson Rocha, and Silvia Figueiredo Costa
- Subjects
Rhodococcus hoagie ,Bacteremia ,Hematopoietic stem cell transplantation ,Infectious and parasitic diseases ,RC109-216 - Abstract
We report a case of bloodstream infection caused by R. hoagii in a woman with acute myeloid leukemia, 37-years-old, who received an allogeneic hematopoietic stem cell transplant. She developed cutaneous and gastrointestinal tract graft versus host disease, respectively on day 29 and day 69. On day 157 she developed to acute severe respiratory failure. Rhodococcus sp was identified by MALDI-TOF and 16S rRNA sequencing from blood culture as Rhodococcus hoagii. The patient was a nurse that lived in urban areas, and stated no recent trips to countryside areas neither contacted with animals. Despite of the treatment with antibiotics with action against R. hoagii such as linezolid and meropenem the patient evolved to multiorgan dysfunction and death. Our case-report emphasizes the importance of early diagnosis and the use of 16S rRNA sequencing to confirmed the identification of species of Rhodococcus infection.
- Published
- 2020
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35. The interaction of the bioinsecticide PA1b (Pea Albumin 1 subunit b) with the insect V-ATPase triggers apoptosis
- Author
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Vanessa Eyraud, Séverine Balmand, Lamis Karaki, Isabelle Rahioui, Catherine Sivignon, Agnès F. Delmas, Corinne Royer, Yvan Rahbé, Pedro Da Silva, and Frédéric Gressent
- Subjects
Medicine ,Science - Abstract
Abstract PA1b (Pea Albumin 1, subunit b) peptide is an entomotoxin, extracted from Legume seeds, with a lethal activity towards several insect pests, such as mosquitoes, some aphids and cereal weevils. This toxin acts by binding to the subunits c and e of the plasma membrane H+-ATPase (V-ATPase) in the insect midgut. In this study, two cereal weevils, the sensitive Sitophilus oryzae strain WAA42, the resistance Sitophilus oryzae strain ISOR3 and the insensitive red flour beetle Tribolium castaneum, were used in biochemical and histological experiments to demonstrate that a PA1b/V-ATPase interaction triggers the apoptosis mechanism, resulting in insect death. Upon intoxication with PA1b, apoptotic bodies are formed in the cells of the insect midgut. In addition, caspase-3 enzyme activity occurs in the midgut of sensitive weevils after intoxication with active PA1b, but not in the midgut of resistant weevils. These biochemical data were confirmed by immuno-histochemical detection of the caspase-3 active form in the midgut of sensitive weevils. Immuno-labelling experiments also revealed that the caspase-3 active form and V-ATPase are close-localized in the insect midgut. The results concerning this unique peptidic V-ATPase inhibitor pave the way for the utilization of PA1b as a promising, more selective and eco-friendly insecticide.
- Published
- 2017
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36. Clonal evolution in myelodysplastic syndromes
- Author
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Pedro da Silva-Coelho, Leonie I. Kroeze, Kenichi Yoshida, Theresia N. Koorenhof-Scheele, Ruth Knops, Louis T. van de Locht, Aniek O. de Graaf, Marion Massop, Sarah Sandmann, Martin Dugas, Marian J. Stevens-Kroef, Jaroslav Cermak, Yuichi Shiraishi, Kenichi Chiba, Hiroko Tanaka, Satoru Miyano, Theo de Witte, Nicole M. A. Blijlevens, Petra Muus, Gerwin Huls, Bert A. van der Reijden, Seishi Ogawa, and Joop H. Jansen
- Subjects
Science - Abstract
Myelodysplastic syndromes are a broad group of haematopoietic malignancies that often progress to acute myeloid leukaemia. Here, the authors show that linear and branched evolution occurs within myelodysplastic syndrome and these patterns can be impacted by treatment.
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- 2017
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37. MENSURAÇÃO E ESPACIALIZAÇÃO DA CONDUTIVIDADE HIDRÁULICA SATURADA: APLICAÇÃO NO EIXO VIÁRIO SUL DA AVENIDA TEOTÔNIO SEGURADO EM PALMAS/TO
- Author
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PEDRO DA SILVA AGUIAR NETO, WILLIAN GOMES BATISTA, BRUNO CARRILHO DE CASTRO, CLERSON DELVANI REIS, GUILHERME ALVES MORAIS, and FLAVIO ROLDÃO DE CARVALHO LELIS
- Subjects
River, lake, and water-supply engineering (General) ,TC401-506 ,Physical geography ,GB3-5030 - Abstract
Com o crescimento acelerado e desordenado dos centros urbanos, deficiências existentes no planejamento urbano são acentuados. Uma das mais visíveis é a drenagem urbana, pois no adensamento da ocupação humana, aumentasse o nível de impermeabilização. Diferente do método comumente adotado, existe uma alternativa compensatória que trabalha em semelhança ao antigo estado natural pela maximização da retenção e infiltração das águas pluviais. A capital Palmas (TO), sofrendo uma desconfortável situação de drenagem urbana, produziu um Plano Municipal de Saneamento Básico que informa o uso dessas técnicas compensatórias para reduzir ou controlar os excedentes pluviais gerados pela impermeabilização. Todavia ainda não existem trabalhos que caracterizem rigorosamente as propriedades físicas de infiltração, elemento essencial a esses projetos. Limitando como área de caracterização o Canteiro Central Sul da Avenida Teotônio Segurado, utilizou-se Permeâmetro de Guelph e análise geoestatística para determinar o parâmetro de infiltração. O dado trabalho observou que as taxas de infiltração estiveram numa maioria entre 1e-5 e 1e-4 m3/s.m2.
- Published
- 2019
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38. PGRP-LB: An Inside View into the Mechanism of the Amidase Reaction
- Author
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Julien Orlans, Carole Vincent-Monegat, Isabelle Rahioui, Catherine Sivignon, Agata Butryn, Laurent Soulère, Anna Zaidman-Remy, Allen M. Orville, Abdelaziz Heddi, Pierre Aller, and Pedro Da Silva
- Subjects
peptidoglycan recognition protein ,PGRP-LB ,X-ray crystallography ,Drosophila melanogaster ,innate immunity ,Biology (General) ,QH301-705.5 ,Chemistry ,QD1-999 - Abstract
Peptidoglycan recognition proteins (PGRPs) are ubiquitous among animals and play pivotal functions in insect immunity. Non-catalytic PGRPs are involved in the activation of immune pathways by binding to the peptidoglycan (PGN), whereas amidase PGRPs are capable of cleaving the PGN into non-immunogenic compounds. Drosophila PGRP-LB belongs to the amidase PGRPs and downregulates the immune deficiency (IMD) pathway by cleaving meso-2,6-diaminopimelic (meso-DAP or DAP)-type PGN. While the recognition process is well analyzed for the non-catalytic PGRPs, little is known about the enzymatic mechanism for the amidase PGRPs, despite their essential function in immune homeostasis. Here, we analyzed the specific activity of different isoforms of Drosophila PGRP-LB towards various PGN substrates to understand their specificity and role in Drosophila immunity. We show that these isoforms have similar activity towards the different compounds. To analyze the mechanism of the amidase activity, we performed site directed mutagenesis and solved the X-ray structures of wild-type Drosophila PGRP-LB and its mutants, with one of these structures presenting a protein complexed with the tracheal cytotoxin (TCT), a muropeptide derived from the PGN. Only the Y78F mutation abolished the PGN cleavage while other mutations reduced the activity solely. Together, our findings suggest the dynamic role of the residue Y78 in the amidase mechanism by nucleophilic attack through a water molecule to the carbonyl group of the amide function destabilized by Zn2+.
- Published
- 2021
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39. Accuracy and stability analysis of horizontal discretizations used in unstructured grid ocean models
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Lapolli, Fabricio Rodrigues, Peixoto, Pedro da Silva, and Korn, Peter
- Subjects
Physics - Fluid Dynamics - Abstract
One important tool at our disposal to evaluate the robustness of Global Circulation Models (GCMs) is to understand the horizontal discretization of the dynamical core under a shallow water approximation. Here, we evaluate the accuracy and stability of different methods used in, or adequate for, unstructured ocean models considering shallow water models. Our results show that the schemes have different accuracy capabilities, with the A- (NICAM) and B-grid (FeSOM 2.0) schemes providing at least 1st order accuracy in most operators and time integrated variables, while the two C-grid (ICON and MPAS) schemes display more difficulty in adequately approximating the horizontal dynamics. Moreover, the theory of the inertia-gravity wave representation on regular grids can be extended for our unstructured based schemes, where from least to most accurate we have: A-, B, and C-grid, respectively. Considering only C-grid schemes, the MPAS scheme has shown a more accurate representation of inertia-gravity waves than ICON. In terms of stability, we see that both A- and C-grid MPAS scheme display the best stability properties, but the A-grid scheme relies on artificial diffusion, while the C-grid scheme doesn't. Alongside, the B-grid and C-grid ICON schemes are within the least stable. Finally, in an effort to understand the effects of potential instabilities in ICON, we note that the full 3D model without a filtering term does not destabilize as it is integrated in time. However, spurious oscillations are responsible for decreasing the kinetic energy of the oceanic currents. Furthermore, an additional decrease of the currents' turbulent kinetic energy is also observed, creating a spurious mixing, which also plays a role in the strength decrease of these oceanic currents.
- Published
- 2023
40. The Development of a Standardized Quality Assessment Material to Support Xpert® HIV-1 Viral Load Testing for ART Monitoring in South Africa
- Author
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Lara Dominique Noble, Lesley Erica Scott, Asiashu Bongwe, Pedro Da Silva, and Wendy Susan Stevens
- Subjects
HIV viral load ,external quality assessment ,verification ,quality ,thermostable ,PrimeStore MTM0 ,Medicine (General) ,R5-920 - Abstract
The tiered laboratory framework for human immunodeficiency virus (HIV) viral load monitoring accommodates a range of HIV viral load testing platforms, with quality assessment critical to ensure quality patient testing. HIV plasma viral load testing is challenged by the instability of viral RNA. An approach using an RNA stabilizing buffer is described for the Xpert® HIV-1 Viral Load (Cepheid) assay and was tested in remote laboratories in South Africa. Plasma panels with known HIV viral titres were prepared in PrimeStore molecular transport medium for per-module verification and per-instrument external quality assessment. The panels were transported at ambient temperatures to 13 testing laboratories during 2017 and 2018, tested according to standard procedures and uploaded to a web portal for analysis. A total of 275 quality assessment specimens (57 verification panels and two EQA cycles) were tested. All participating laboratories met study verification criteria (n = 171 specimens) with an overall concordance correlation coefficient (ρc) of 0.997 (95% confidence interval (CI): 0.996 to 0.998) and a mean bias of −0.019 log copies per milliliter (cp/mL) (95% CI: −0.044 to 0.063). The overall EQA ρc (n = 104 specimens) was 0.999 (95% CI: 0.998 to 0.999), with a mean bias of 0.03 log cp/mL (95% CI: 0.02 to 0.05). These panels are suitable for use in quality monitoring of Xpert® HIV-1 VL and are applicable to laboratories in remote settings.
- Published
- 2021
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41. Parallel-in-time integration of the shallow water equations on the rotating sphere using Parareal and MGRIT
- Author
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Steinstraesser, João Guilherme Caldas, Peixoto, Pedro da Silva, and Schreiber, Martin
- Subjects
Mathematics - Numerical Analysis ,65Y05, 65M99 ,G.1.8 ,G.1.10 - Abstract
Despite the growing interest in parallel-in-time methods as an approach to accelerate numerical simulations in atmospheric modelling, improving their stability and convergence remains a substantial challenge for their application to operational models. In this work, we study the temporal parallelization of the shallow water equations on the rotating sphere combined with time-stepping schemes commonly used in atmospheric modelling due to their stability properties, namely an Eulerian implicit-explicit (IMEX) method and a semi-Lagrangian semi-implicit method (SL-SI-SETTLS). The main goal is to investigate the performance of parallel-in-time methods, namely Parareal and Multigrid Reduction in Time (MGRIT), when these well-established schemes are used on the coarse discretization levels and provide insights on how they can be improved for better performance. We begin by performing an analytical stability study of Parareal and MGRIT applied to a linearized ordinary differential equation depending on the choice of a coarse scheme. Next, we perform numerical simulations of two standard tests to evaluate the stability, convergence and speedup provided by the parallel-in-time methods compared to a fine reference solution computed serially. We also conduct a detailed investigation on the influence of artificial viscosity and hyperviscosity approaches, applied on the coarse discretization levels, on the performance of the temporal parallelization. Both the analytical stability study and the numerical simulations indicate a poorer stability behaviour when SL-SI-SETTLS is used on the coarse levels, compared to the IMEX scheme. With the IMEX scheme, a better trade-off between convergence, stability and speedup compared to serial simulations can be obtained under proper parameters and artificial viscosity choices, opening the perspective of the potential competitiveness for realistic models., Comment: 35 pages, 23 figures
- Published
- 2023
42. A comunicação ambiental e suas potencialidades no enfrentamento dos dilemas socioambientais
- Author
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Myrian Del Vecchio de Lima, Pedro da Silva Júnior, Eloísa Belling Loose, Danielle Scheffelmeier Mei, Thaís Cristina Schneider, and Valéria Sousa Duarte
- Subjects
communication ,environment ,environmental communication ,interfaces ,epistemology ,Environmental sciences ,GE1-350 - Abstract
This paper provides reflections over the notion of environmental communication, seeking to contribute on the construction of the concept that defines this kind of communication, considered specialized and of interface. The argument stated is that environmental communication is characterized by embracing perspectives and fundamentals of both the communication and the environmental fields, since it is situated in their interweave, emphasizing its interdisciplinary character. Initially, the epistemological bases of both fields are presented, in order to highlight the practical and theoretical articulations that occur between them. A literature review about the term is then provided, considering national and international authors, followed by the argumentation that environmental communication is not simply about dealing with thematic features of the environmental field. Finally, some reflections on its possibilities to assist in coping actions of contemporary social and environmental problems are offered.
- Published
- 2015
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43. Implementation of erythroid lineage analysis by flow cytometry in diagnostic models for myelodysplastic syndromes
- Author
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Eline M.P. Cremers, Theresia M. Westers, Canan Alhan, Claudia Cali, Heleen A. Visser-Wisselaar, Dana A. Chitu, Vincent H.J. van der Velden, Jeroen G. te Marvelde, Saskia K. Klein, Petra Muus, Edo Vellenga, Georgina E. de Greef, Marie-Cecile C.J.C. Legdeur, Pierre W. Wijermans, Marian J.P.L. Stevens-Kroef, Pedro da Silva-Coelho, Joop H. Jansen, Gert J. Ossenkoppele, and Arjan A. van de Loosdrecht
- Subjects
Diseases of the blood and blood-forming organs ,RC633-647.5 - Abstract
Flow cytometric analysis is a recommended tool in the diagnosis of myelodysplastic syndromes. Current flow cytometric approaches evaluate the (im)mature myelo-/monocytic lineage with a median sensitivity and specificity of ~71% and ~93%, respectively. We hypothesized that the addition of erythroid lineage analysis could increase the sensitivity of flow cytometry. Hereto, we validated the analysis of erythroid lineage parameters recommended by the International/European LeukemiaNet Working Group for Flow Cytometry in Myelodysplastic Syndromes, and incorporated this evaluation in currently applied flow cytometric models. One hundred and sixty-seven bone marrow aspirates were analyzed; 106 patients with myelodysplastic syndromes, and 61 cytopenic controls. There was a strong correlation between presence of erythroid aberrancies assessed by flow cytometry and the diagnosis of myelodysplastic syndromes when validating the previously described erythroid evaluation. Furthermore, addition of erythroid aberrancies to two different flow cytometric models led to an increased sensitivity in detecting myelodysplastic syndromes: from 74% to 86% for the addition to the diagnostic score designed by Ogata and colleagues, and from 69% to 80% for the addition to the integrated flow cytometric score for myelodysplastic syndromes, designed by our group. In both models the specificity was unaffected. The high sensitivity and specificity of flow cytometry in the detection of myelodysplastic syndromes illustrates the important value of flow cytometry in a standardized diagnostic approach. The trial is registered at www.trialregister.nl as NTR1825; EudraCT n.: 2008-002195-10
- Published
- 2017
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44. EXPANSÃO URBANA NO MUNICÍPIO DE PINDAMONHANGABA, SP: QUESTÔES DE ESTUDO DO PLANEJAMENTO URBANO E REGIONAL
- Author
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Pedro da Silva Corrêa, Daniel José de Andrade, and Cilene Gomes
- Subjects
Expansão urbana ,Planejamento urbano e regional ,Interesse público. ,General Works - Abstract
O artigo trata da expansão urbana do município de Pindamonhangaba (SP), no contexto da urbanização do Vale do Paraíba paulista, nas imediações da Rodovia Presidente Dutra. Promovendo o crescimento da área urbanizada, a expansão urbana se desenvolve segundo um modelo específico do tecido urbano, resultando em uma configuração de cidade mais ou menos compacta ou dispersa. A expansão urbana acarreta diversas mudanças na estrutura espacial da cidade, podendo criar problemas para a vida social urbana, e por isso, é pensada e questionada em sua relação com o planejamento urbano e regional. Por meio de um controle público e social, deve-se evitar que a expansão urbana agrave os problemas pré-existentes, ou crie novos problemas. O artigo traz uma caracterização de Pindamonhangaba, correlacionada a uma leitura da expansão urbana, ocorrida nas últimas quatro décadas, e a uma breve discussão sobre as relações entre o modelo da expansão urbana e questões de estudo do planejamento urbano e regional, na perspectiva de ordenação territorial e urbana fundada no interesse público, no interesse de todos e do espaço de todos.
- Published
- 2016
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45. Pea Albumin 1 Subunit b (PA1b), a Promising Bioinsecticide of Plant Origin
- Author
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Corinne Royer, Vanessa Eyraud, Lamis Karaki, Frédéric Gressent, and Pedro Da Silva
- Subjects
PA1b ,insect ,bioinsecticide ,Legumes ,Medicine - Abstract
PA1b (Pea Albumin 1, subunit b) is a peptide extract from pea seeds showing significant insecticidal activity against certain insects, such as cereal weevils (genus Sitophilus), the mosquitoes Culex pipiens and Aedes aegyptii, and certain species of aphids. PA1b has great potential for use on an industrial scale and for use in organic farming: it is extracted from a common plant; it is a peptide (and therefore suitable for transgenic applications); it can withstand many steps of extraction and purification without losing its activity; and it is present in a seed regularly consumed by humans and mammals without any known toxicity or allergenicity. The potential of this peptide to limit pest damage has stimulated research concerning its host range, its mechanism of action, its three-dimensional structure, the natural diversity of PA1b and its structure–function relationships.
- Published
- 2011
- Full Text
- View/download PDF
46. Development and validation of natural user interfaces for semantic enrichment of BIM models using open formats
- Author
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Matoseiro Dinis, Fábio, Rodrigues, Raquel, and Pedro da Silva Poças Martins, João
- Published
- 2024
- Full Text
- View/download PDF
47. Expression and biological activity of the cystine knot bioinsecticide PA1b (Pea Albumin 1 Subunit b).
- Author
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Vanessa Eyraud, Lamis Karaki, Isabelle Rahioui, Catherine Sivignon, Pedro Da Silva, Yvan Rahbé, Corinne Royer, and Frédéric Gressent
- Subjects
Medicine ,Science - Abstract
The PA1b (Pea Albumin 1, subunit b) peptide is an entomotoxin extract from Legume seeds with lethal activity on several insect pests, such as mosquitoes, some aphids and cereal weevils. This 37 amino-acid cysteine-rich peptide has been, until now, obtained by biochemical purification or chemical synthesis. In this paper, we present our results for the transient production of the peptide in Nicotiana benthamiana by agro-infiltration, with a yield of about 35 µg/g of fresh leaves and maximum production 8 days after infiltration. PA1b is part of the PA1 gene which, after post-translational modifications, encodes two peptides (PA1b and PA1a). We show that transforming tobacco with the PA1b cDNA alone does not result in production of the toxin and, in fact, the entire cDNA is necessary, raising the question of the role of PA1a. We constructed a PA1-cassette, allowing for the quick "cut/paste" of different PA1b mutants within a conserved PA1 cDNA. This cassette enabled us to produce the six isoforms of PA1b which exist in pea seeds. Biological tests revealed that all the isoforms display similar activity, with the exception of one which is inactive. The lack of activity in this isoform led us to conclude that the amphiphilic nature of the peptide is necessary for activity. The possible applications of this expression system for other cysteine-rich biomolecules are discussed.
- Published
- 2013
- Full Text
- View/download PDF
48. MUSICAL EDUCATION: NEWS SUPPORTS AND PROJECTS
- Author
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Pedro da Silva Guimarães
- Subjects
inclusão ,educação ,musica ,projetos de trabalho. ,Arts in general ,NX1-820 ,Language and Literature - Abstract
This paper focuses on the search for new proposals in the musical education, which enable the work with children with special needs in the school network. The article was produced specifically for a field research with people with serious disorders, including autistic children and children with psychosis. The objective of this work is to present a practical work undertaken in a therapeutic area for a focus on inclusion and work with heterogeneous classes. Emphasizes the search for new media and tools, such as the use of concrete materials and to address the visual and musical sound parameters and methodology of project work (Hernndez F. VENTURA M., 1998). This work has the assumption that a musical education based on the search for new supports for the symbolic encoding and decoding of sound projects and the development of work, bring positive results in inclusive classes.
- Published
- 2009
49. Characterization of modified titanium surfaces by anodisation and immersion tests
- Author
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Palma, Dener Pedro da Silva, Silva, Giovana Pedroso, Zago, Fernanda Mathidios, Codaro, Eduardo Norberto, and Acciari, Heloisa Andréa
- Published
- 2024
- Full Text
- View/download PDF
50. BIM in construction waste management: A conceptual model based on the industry foundation classes standard
- Author
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Schamne, Annelise Nairne, Nagalli, André, Soeiro, Alfredo Augusto Vieira, and Poças Martins, João Pedro da Silva
- Published
- 2024
- Full Text
- View/download PDF
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