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1.
Nature ; 605(7911): 653-658, 2022 05.
Artigo em Inglês | MEDLINE | ID: mdl-35364602

RESUMO

Before the Perseverance rover landing, the acoustic environment of Mars was unknown. Models predicted that: (1) atmospheric turbulence changes at centimetre scales or smaller at the point where molecular viscosity converts kinetic energy into heat1, (2) the speed of sound varies at the surface with frequency2,3 and (3) high-frequency waves are strongly attenuated with distance in CO2 (refs. 2-4). However, theoretical models were uncertain because of a lack of experimental data at low pressure and the difficulty to characterize turbulence or attenuation in a closed environment. Here, using Perseverance microphone recordings, we present the first characterization of the acoustic environment on Mars and pressure fluctuations in the audible range and beyond, from 20 Hz to 50 kHz. We find that atmospheric sounds extend measurements of pressure variations down to 1,000 times smaller scales than ever observed before, showing a dissipative regime extending over five orders of magnitude in energy. Using point sources of sound (Ingenuity rotorcraft, laser-induced sparks), we highlight two distinct values for the speed of sound that are about 10 m s-1 apart below and above 240 Hz, a unique characteristic of low-pressure CO2-dominated atmosphere. We also provide the acoustic attenuation with distance above 2 kHz, allowing us to explain the large contribution of the CO2 vibrational relaxation in the audible range. These results establish a ground truth for the modelling of acoustic processes, which is critical for studies in atmospheres such as those of Mars and Venus.

3.
Phytopathology ; 113(9): 1761-1772, 2023 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-37014099

RESUMO

Understanding the emergence and prevalence of viral diseases in crops requires the systematic epidemiological monitoring of viruses, as well as the analysis of how ecological and evolutionary processes combine to shape viral population dynamics. Here, we extensively monitored the occurrence of six aphid-transmitted viruses in melon and zucchini crops in Spain for 10 consecutive cropping seasons between 2011 and 2020. The most prevalent viruses were cucurbit aphid-borne yellows virus (CABYV) and watermelon mosaic virus (WMV), found in 31 and 26% of samples with yellowing and mosaic symptoms. Other viruses, such as zucchini yellow mosaic virus, cucumber mosaic virus, Moroccan watermelon mosaic virus, and papaya ring spot virus, were detected less frequently (<3%) and mostly in mixed infections. Notably, our statistical analysis showed a significant association between CABYV and WMV in melon and zucchini hosts, suggesting that mixed infections might be influencing the evolutionary epidemiology of these viral diseases. We then carried out a comprehensive genetic characterization of the full-length genome sequences from CABYV and WMV isolates by using the Pacific Biosciences single-molecule real-time (PacBio) high-throughput technology to assess the genetic variation and structure of their populations. Our results showed that the CABYV population displayed seven codons under positive selection, and although most isolates clustered in the Mediterranean clade, a subsequent analysis of molecular variance revealed a significant, fine-scale temporal structure, which was in part explained by the level of the variance between isolates from single and mixed infections. In contrast, the WMV population genetic analysis showed that most of the isolates grouped into the Emergent clade, with no genetic differentiation and under purifying selection. These results underlie the epidemiological relevance of mixed infections for CABYV and provide a link between genetic diversity and CABYV dynamics at the whole-genome level.


Assuntos
Afídeos , Coinfecção , Cucurbita , Cucurbitaceae , Luteoviridae , Viroses , Animais , Doenças das Plantas , Luteoviridae/genética , Produtos Agrícolas , Verduras , Variação Genética
4.
Rev Clin Esp ; 223(1): 32-39, 2023 Jan.
Artigo em Espanhol | MEDLINE | ID: mdl-36277866

RESUMO

Viral infections during pregnancy have been one of the leading causes associated with significant perinatal problems, such as congenital defects, fetal neurological syndromes, stillbirths, and adverse pregnancy outcomes. The mpox virus infection, caused by an Orthopoxvirus related to the human smallpox virus, was declared a global health emergency by the World Health Organization in July 2022 due to the large number of cases emerging outside the usual endemic area in Africa. There is little information on the impact of mpox virus infection during pregnancy, although the limited evidence available shows a high rate of fetal harm. This review addresses the problem of mpox virus infection in pregnant women and provides indications for its prevention, diagnosis, and treatment.

5.
Geophys Res Lett ; 49(17): e2022GL099776, 2022 Sep 16.
Artigo em Inglês | MEDLINE | ID: mdl-36245894

RESUMO

Observations by several cameras on the Perseverance rover showed a 22° scattering halo around the Sun over several hours during northern midsummer (solar longitude 142°). Such a halo has not previously been seen beyond Earth. The halo occurred during the aphelion cloud belt season and the cloudiest time yet observed from the Perseverance site. The halo required crystalline water-ice cloud particles in the form of hexagonal columns large enough for refraction to be significant, at least 11 µm in diameter and length. From a possible 40-50 km altitude, and over the 3.3 hr duration of the halo, particles could have fallen 3-12 km, causing downward transport of water and dust. Halo-forming clouds are likely rare due to the high supersaturation of water that is required but may be more common in northern subtropical regions during northern midsummer.

6.
Geophys Res Lett ; 49(17): e2022GL100126, 2022 Sep 16.
Artigo em Inglês | MEDLINE | ID: mdl-36245893

RESUMO

Rovers and landers on Mars have experienced local, regional, and planetary-scale dust storms. However, in situ documentation of active lifting within storms has remained elusive. Over 5-11 January 2022 (LS 153°-156°), a dust storm passed over the Perseverance rover site. Peak visible optical depth was ∼2, and visibility across the crater was briefly reduced. Pressure amplitudes and temperatures responded to the storm. Winds up to 20 m s-1 rotated around the site before the wind sensor was damaged. The rover imaged 21 dust-lifting events-gusts and dust devils-in one 25-min period, and at least three events mobilized sediment near the rover. Rover tracks and drill cuttings were extensively modified, and debris was moved onto the rover deck. Migration of small ripples was seen, but there was no large-scale change in undisturbed areas. This work presents an overview of observations and initial results from the study of the storm.

7.
Antimicrob Agents Chemother ; 65(9): e0043221, 2021 08 17.
Artigo em Inglês | MEDLINE | ID: mdl-34152813

RESUMO

Soil-transmitted-helminth (STH) infections are a persistent global public health problem. Control strategies for STH have been based on the use of mass drug administration (MDA) mainly targeting preschool- and school-aged-children, although there is increasing interest in expanding treatment to include adults and others through community-wide MDA. Coverage assessment is critical to understanding the real effectiveness of albendazole (ALB) treatment in those MDA programs. The work described here aims to (i) evaluate the effect of type of diet (a heavy or light meal) and fasting before ALB treatment on the systemic disposition of ALB and its metabolites in treated human volunteers and (ii) evaluate the potential feasibility of detecting albendazole metabolites in urine. The data reported here demonstrate that the systemic availability of the active ALB-sulfoxide (ALBSO) metabolite was enhanced more than 2-fold after food ingestion (a heavy or light meal). ALB dissolution improvement related to the ingestion of food may modify the amount of drug/metabolites reaching the parasite, affecting drug efficacy and the overall success of MDA strategies. The measurement in urine samples of the amino-ALB-sulfone (NHALBSO2) derivative and ALBSO for up to 96 h suggests that it may be feasible to develop a noninvasive tool to evaluate compliance/adherence to ALB treatment.


Assuntos
Anti-Helmínticos , Helmintíase , Absorção Fisiológica , Adulto , Albendazol/uso terapêutico , Anti-Helmínticos/uso terapêutico , Criança , Pré-Escolar , Voluntários Saudáveis , Helmintíase/tratamento farmacológico , Humanos , Administração Massiva de Medicamentos , Solo
8.
Ultrasound Obstet Gynecol ; 58(6): 900-908, 2021 12.
Artigo em Inglês | MEDLINE | ID: mdl-34580942

RESUMO

OBJECTIVE: Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) vertical transmission has been investigated extensively. Recently, the World Health Organization (WHO) published strict criteria to classify the timing of mother-to-child transmission of SARS-CoV-2 into different categories. The aim of this study was to investigate the possibility of vertical transmission in asymptomatic SARS-CoV-2-positive women. METHODS: Pregnant women attending for delivery at a perinatology center in Mexico City, Mexico, who had a SARS-CoV-2-positive nasopharyngeal swab 24-48 h before delivery, were asymptomatic at the time of the test and had an obstetric indication for Cesarean section were eligible for inclusion in this study. Amniotic fluid was collected during Cesarean delivery, and neonatal oral and rectal swabs were collected at birth and at 24 h after birth. SARS-CoV-2 detection was carried out using real-time reverse-transcription polymerase chain reaction in all samples. Relevant medical information was retrieved from clinical records. The WHO criteria for classifying the timing of mother-to-child transmission of SARS-CoV-2 were applied to the study population. RESULTS: Forty-two SARS-CoV-2-positive asymptomatic pregnant women fulfilled the inclusion criteria. Twenty-five (59%) women developed mild disease after discharge. Neonatal death occurred in three (7%) cases, of which one had a positive SARS-CoV-2 test at birth and none had coronavirus disease 2019-related symptoms. There were five (12%) cases with strong evidence of intrauterine transmission of SARS-CoV-2, according to the WHO criteria, as amniotic fluid samples and neonatal samples at birth and at 24 h after birth were positive for SARS-CoV-2. Our results also showed that 40-60% of infected neonates would have been undetected if only one swab (oral or rectal) was tested. CONCLUSION: This study contributes evidence to reinforce the potential for vertical transmission of SARS-CoV-2 even in asymptomatic women and highlights the importance of testing more than one neonatal sample in order to increase the detection rate of SARS-CoV-2 in affected cases. © 2021 The Authors. Ultrasound in Obstetrics & Gynecology published by John Wiley & Sons Ltd on behalf of International Society of Ultrasound in Obstetrics and Gynecology.


Assuntos
COVID-19/transmissão , Transmissão Vertical de Doenças Infecciosas , Adulto , COVID-19/diagnóstico , COVID-19/epidemiologia , Teste de Ácido Nucleico para COVID-19 , Cesárea , Estudos de Coortes , Feminino , Humanos , Recém-Nascido , México/epidemiologia , Pessoa de Meia-Idade , Triagem Neonatal , Gravidez , Complicações Infecciosas na Gravidez/diagnóstico , Complicações Infecciosas na Gravidez/epidemiologia , SARS-CoV-2/isolamento & purificação , SARS-CoV-2/patogenicidade
9.
Insect Mol Biol ; 29(5): 431-443, 2020 10.
Artigo em Inglês | MEDLINE | ID: mdl-32484986

RESUMO

Insect cuticle hydrocarbons are involved primarily in waterproofing the cuticle, but also participate in chemical communication and regulate the penetration of insecticides and microorganisms. The last step in insect hydrocarbon biosynthesis is carried out by an insect-specific cytochrome P450 of the 4G subfamily (CYP4G). Two genes (CYP4G106 and CYP4G107) have been reported in the triatomines Rhodnius prolixus and Triatoma infestans. In this work, their molecular and functional characterization is carried out in R. prolixus, and their relevance to insect survival is assessed. Both genes are expressed almost exclusively in the integument and have an expression pattern dependent on the developmental stage and feeding status. CYP4G106 silencing diminished significantly the straight-chain hydrocarbon production while a significant reduction - mostly of methyl-branched chain hydrocarbons - was observed after CYP4G107 silencing. Molecular docking analyses using different aldehydes as hydrocarbon precursors predicted a better fit of straight-chain aldehydes with CYP4G106 and methyl-branched aldehydes with CYP4G107. Survival bioassays exposing the silenced insects to desiccation stress showed that CYP4G107 is determinant for the waterproofing properties of the R. prolixus cuticle. This is the first report on the in vivo specificity of two CYP4Gs to make mostly straight or methyl-branched hydrocarbons, and also on their differential contribution to insect desiccation.


Assuntos
Família 4 do Citocromo P450/genética , Dessecação , Hidrocarbonetos/metabolismo , Proteínas de Insetos/genética , Rhodnius/fisiologia , Animais , Família 4 do Citocromo P450/metabolismo , Proteínas de Insetos/metabolismo , Ninfa/genética , Ninfa/crescimento & desenvolvimento , Ninfa/fisiologia , Rhodnius/genética , Rhodnius/crescimento & desenvolvimento
10.
Phytopathology ; 110(1): 49-57, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31524081

RESUMO

Mixed viral infections are common in plants, and the evolutionary dynamics of viral populations may differ depending on whether the infection is caused by single or multiple viral strains. However, comparative studies of single and mixed infections using viral populations in comparable agricultural and geographical locations are lacking. Here, we monitored the occurrence of pepino mosaic virus (PepMV) in tomato crops in two major tomato-producing areas in Murcia (southeastern Spain), supporting evidence showing that PepMV disease-affected plants had single infections of the Chilean 2 (CH2) strain in one area and the other area exhibited long-term (13 years) coexistence of the CH2 and European (EU) strains. We hypothesized that circulating strains of PepMV might be modulating the differentiation between them and shaping the evolutionary dynamics of PepMV populations. Our phylogenetic analysis of 106 CH2 isolates randomly selected from both areas showed a remarkable divergence between the CH2 isolates, with increased nucleotide variability in the geographical area where both strains cocirculate. Furthermore, the potential virus-virus interaction was studied further by constructing six full-length infectious CH2 clones from both areas, and assessing their viral fitness in the presence and absence of an EU-type isolate. All CH2 clones showed decreased fitness in mixed infections and although complete genome sequencing indicated a nucleotide divergence of those CH2 clones by area, the magnitude of the fitness response was irrespective of the CH2 origin. Overall, these results suggest that although agroecological cropping practices may be particularly important for explaining the evolutionary dynamics of PepMV in tomato crops, the cocirculation of both strains may have implications on the genetic variability of PepMV populations.


Assuntos
Variação Genética , Potexvirus , Solanum lycopersicum , Genética Populacional , Solanum lycopersicum/virologia , Filogenia , Doenças das Plantas/virologia , Potexvirus/genética , Espanha/epidemiologia
11.
Ecotoxicol Environ Saf ; 188: 109893, 2020 Jan 30.
Artigo em Inglês | MEDLINE | ID: mdl-31735370

RESUMO

Cellular and humoral responses were evaluated in Litopenaeus vannamei juveniles when exposed to malathion, endosulfan, and their mixture. Each experiment was performed in the hemolymph collected at each exposure time (5 and 96 h) in duplicate; total hemocyte count, coagulation time, hemocyanin concentration, phenoloxidase (PO) and superoxide dismutase (SOD) activities were quantified. Survival was not affected by pesticides applied individually and mixed. Clotting time did not show significant differences concerning increase of concentration percentage of the pesticides tested. In organisms exposed to the pesticide mixture, hemocyanin decreased at 5 h of exposure as the concentration increased. Only in the malathion experiment did exposed shrimp to 10 and 50% of the LC50-96 h show significantly (p < 0.05) higher hemocyte contents. For malathion, significantly (p < 0.05) lower PO values in shrimp exposed to higher concentrations (10 and 50% of the LC50-96 h) were determined. While for the mixture treatment, high SOD value was determined at high exposure time and concentration. Malathion was the pesticide that showed an effect on some variables even at sublethal concentrations. The Continuous Concentration Criteria of the United States Environmental Protection Agency did not represent effects on the variables when they were compared with the averages of the control group.


Assuntos
Endossulfano/toxicidade , Imunidade Celular/efeitos dos fármacos , Imunidade Humoral/efeitos dos fármacos , Malation/toxicidade , Penaeidae/efeitos dos fármacos , Animais , Sinergismo Farmacológico , Hemocianinas/sangue , Hemócitos/efeitos dos fármacos , Hemócitos/imunologia , Hemolinfa/efeitos dos fármacos , Hemolinfa/imunologia , Monofenol Mono-Oxigenase/metabolismo , Penaeidae/imunologia
12.
Rev Clin Esp ; 2020 Mar 20.
Artigo em Inglês, Espanhol | MEDLINE | ID: mdl-32204922

RESUMO

A new coronavirus outbreak emerged on the 31st of December 2019 in Wuhan, China, causing commotion among the medical community and the rest of the world. This new species of coronavirus has been termed 2019-nCoV and has caused a considerable number of cases of infection and deaths in China and, to a growing degree, beyond China, becoming a worldwide public health emergency. 2019-nCoV has high homology to other pathogenic coronaviruses, such as those originating from bat-related zoonosis (SARS-CoV), which caused approximately 646 deaths in China at the start of the decade. The mortality rate for 2019-nCoV is not as high (approximately 2-3%), but its rapid propagation has resulted in the activation of protocols to stop its spread. This pathogen has the potential to become a pandemic. It is therefore vital to follow the personal care recommendations issued by the World Health Organisation.

13.
Proc Biol Sci ; 286(1907): 20191091, 2019 07 24.
Artigo em Inglês | MEDLINE | ID: mdl-31311476

RESUMO

Malaria incidence has halved since the year 2000, with 80% of the reduction attributable to the use of insecticides. However, insecticide resistance is now widespread, is rapidly increasing in spectrum and intensity across Africa, and may be contributing to the increase of malaria incidence in 2018. The role of detoxification enzymes and target site mutations has been documented in the major malaria vector Anopheles gambiae; however, the emergence of striking resistant phenotypes suggests the occurrence of additional mechanisms. By comparing legs, the most relevant insect tissue for insecticide uptake, we show that resistant mosquitoes largely remodel their leg cuticles via enhanced deposition of cuticular proteins and chitin, corroborating a leg-thickening phenotype. Moreover, we show that resistant female mosquitoes seal their leg cuticles with higher total and different relative amounts of cuticular hydrocarbons, compared with susceptible ones. The structural and functional alterations in Anopheles female mosquito legs are associated with a reduced uptake of insecticides, substantially contributing to the resistance phenotype.


Assuntos
Anopheles/fisiologia , Extremidades/fisiologia , Resistência a Inseticidas , Inseticidas/farmacologia , Mosquitos Vetores/fisiologia , Animais , Anopheles/ultraestrutura , Feminino , Lipidômica , Malária/transmissão , Masculino , Microscopia Eletrônica de Transmissão , Mosquitos Vetores/ultraestrutura , Proteoma , Proteômica
14.
Insect Mol Biol ; 28(6): 850-861, 2019 12.
Artigo em Inglês | MEDLINE | ID: mdl-31125161

RESUMO

Fatty acid synthase is a multifunctional enzyme involved in the formation of fatty acids. Despite the role of fatty acids in cell signalling and energy metabolism, and as precursors to pheromones and hydrocarbons that waterproof the cuticle, the insect fatty acid synthases have been scarcely studied. Here we perform the molecular characterization of three fatty acid synthase genes (fatty acid synthase RPRC000123, RPRC000269 and RPRC002909) in the Chagas disease vector, Rhodnius prolixus. Gene expression screening by reverse transcription quantitative PCR showed that RPRC000123 and RPRC002909 are expressed almost exclusively in the integument tissue whilst RPRC000269 is mostly expressed in the fat body and also in several body organs. Phylogenetic analysis, together with gene expression results, showed that RPRC000269, RPRC002909 and RPRC000123 are orthologues of Drosophila melanogaster fatty acid synthase 1 (FASN1), FASN2 and FASN3 genes, respectively. After RNA interference-mediated knockdown of RPRC000123, insects died immediately after moulting to the next developmental stage. However, mortality was prevented by placing the insects under saturated humidity conditions, suggesting that dehydration might play a role in the insects' death. Lipid analyses in RPRC000123-silenced insects showed reduced amounts of integument fatty acids and methyl-branched hydrocarbons, compared to controls. These data support an important role for FASN3 in the biosynthesis of the precursors to hydrocarbons that waterproof the insect cuticle.


Assuntos
Ácido Graxo Sintases/genética , Proteínas de Insetos/genética , Água/metabolismo , Animais , Ácido Graxo Sintases/metabolismo , Proteínas de Insetos/metabolismo , Tegumento Comum/fisiologia , Ninfa/crescimento & desenvolvimento , Ninfa/fisiologia , Filogenia , Rhodnius , Perda Insensível de Água
15.
Virus Genes ; 55(3): 406-410, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-30758769

RESUMO

The respiratory syncytial virus (RSV) is the main pathogen associated with upper respiratory tract infections during early childhood. Vertical transmission of this virus has been suggested in humans, based on observations recorded during animal studies that revealed an association of RSV with persistent structural and functional changes in the developing lungs of the offspring. However, human placentas have not yet been evaluated for susceptibility to RSV infection. In this study, we examined the capacity of RSV to infect a human trophoblast model, the BeWo cell line. Our results suggest that BeWo cells are susceptible to RSV infection since they allow RNA viral replication, viral protein translation, leading to the production of infectious RSV particles. In this report, we demonstrate that a human placenta model system, consisting of BeWo cells, is permissive to RSV infection. Thus, the BeWo cell line may represent a useful model for studies that aim to characterize the events of a possible RSV infection at the human maternal-fetal interface.


Assuntos
Linhagem Celular Tumoral/virologia , Coriocarcinoma/virologia , Infecções por Vírus Respiratório Sincicial/genética , Vírus Sinciciais Respiratórios/genética , Coriocarcinoma/complicações , Coriocarcinoma/genética , Feminino , Humanos , Placenta/patologia , Placenta/virologia , Gravidez , RNA Viral/genética , Infecções por Vírus Respiratório Sincicial/complicações , Infecções por Vírus Respiratório Sincicial/virologia , Vírus Sinciciais Respiratórios/patogenicidade
16.
Subcell Biochem ; 88: 407-442, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-29900506

RESUMO

Flaviviruses are positive, single-stranded, enveloped cytoplasmic sense RNA viruses that cause a variety of important diseases worldwide. Among them, Zika virus, West Nile virus, Japanese encephalitis virus, and Dengue virus have the potential to cause severe disease. Extensive studies have been performed to elucidate the structure and replication strategies of flaviviruses, and current studies are aiming to unravel the complex molecular interactions between the virus and host during the very early stages of infection. The outcomes of viral infection and rapid establishment of the antiviral state, depends on viral detection by pathogen recognition receptors and rapid initiation of signalling cascades to induce an effective innate immune response. Extracellular and intracellular pathogen recognition receptors play a crucial role in detecting flavivirus infection and inducing a robust antiviral response. One of the main hallmarks of flaviviral nonstructural proteins is their multiple strategies to antagonise the interferon system. In this chapter, we summarize the molecular characteristics of flaviviral proteins and discuss how viral proteins target different components of the interferon signalling pathway by blocking phosphorylation, enhancing degradation, and downregulating the expression of major components of the Janus kinase/signal transducer and activator of transcription pathway. We also discuss how the interactions of viral proteins with host proteins facilitate viral pathogenesis. Due to the lack of antivirals or prophylactic treatments for many flaviviral infections, it is necessary to fully elucidate how these viruses disrupt cellular processes to influence pathogenesis and disease outcomes.


Assuntos
Infecções por Flavivirus/imunologia , Flavivirus/imunologia , Imunidade Inata , Interferons/imunologia , Transdução de Sinais/imunologia , Proteínas não Estruturais Virais/imunologia , Animais , Flavivirus/patogenicidade , Infecções por Flavivirus/patologia , Humanos , Janus Quinases/imunologia
17.
Bull Entomol Res ; 109(2): 178-190, 2019 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-29784067

RESUMO

Anastrepha fraterculus (Wiedemann), a pest of great economic importance in South America, needs urgently to be controlled by environmentally friendly methods such as the sterile insect technique for which mass rearing of insects is required. Because oogenesis takes place during the adult stage, mass-rearing facilities should provide the females a diet that maximizes egg production at the lowest cost. Accordingly, we investigated the effect of artificial protein sources in the adult diet (yeast derivatives of different cost but with similar amino acids profiles, and the addition of wheat germ) on fecundity. Additionally, we evaluated different ratios of yeast derivatives or wheat germ on ovary maturation, fecundity, and fertility as well as their association with the nutrient content of females. Females fed hydrolyzed yeast and yeast extract attained the highest fecundity level, and those fed brewer's yeast the lowest. Reducing the amount of hydrolyzed yeast, an expensive protein source, in the diet negatively affected fecundity and ovary maturation. Increasing the amount of brewer's yeast, a low-cost protein source, did not favor fecundity. The addition of wheat germ in the adult diet improved fecundity regardless of the yeast derivate considered. Percentage of egg hatch was not affected by the diet. Nutrient content of A. fraterculus females varied according to the adult diet provided and mating status. Our findings provide novel baseline information to understand the role of nutrition on reproductive performance of A. fraterculus females and are discussed in the context of resource allocation. They also provide valuable advances in the search for cost-effective adult diets at fruit fly mass rearing facilities.


Assuntos
Dieta , Oviparidade , Tephritidae/fisiologia , Animais , Feminino , Fertilidade , Ovário/fisiologia , Triticum , Leveduras
18.
Proc Natl Acad Sci U S A ; 113(33): 9268-73, 2016 08 16.
Artigo em Inglês | MEDLINE | ID: mdl-27439866

RESUMO

The role of cuticle changes in insecticide resistance in the major malaria vector Anopheles gambiae was assessed. The rate of internalization of (14)C deltamethrin was significantly slower in a resistant strain than in a susceptible strain. Topical application of an acetone insecticide formulation to circumvent lipid-based uptake barriers decreased the resistance ratio by ∼50%. Cuticle analysis by electron microscopy and characterization of lipid extracts indicated that resistant mosquitoes had a thicker epicuticular layer and a significant increase in cuticular hydrocarbon (CHC) content (∼29%). However, the CHC profile and relative distribution were similar in resistant and susceptible insects. The cellular localization and in vitro activity of two P450 enzymes, CYP4G16 and CYP4G17, whose genes are frequently overexpressed in resistant Anopheles mosquitoes, were analyzed. These enzymes are potential orthologs of the CYP4G1/2 enzymes that catalyze the final step of CHC biosynthesis in Drosophila and Musca domestica, respectively. Immunostaining indicated that both CYP4G16 and CYP4G17 are highly abundant in oenocytes, the insect cell type thought to secrete hydrocarbons. However, an intriguing difference was indicated; CYP4G17 occurs throughout the cell, as expected for a microsomal P450, but CYP4G16 localizes to the periphery of the cell and lies on the cytoplasmic side of the cell membrane, a unique position for a P450 enzyme. CYP4G16 and CYP4G17 were functionally expressed in insect cells. CYP4G16 produced hydrocarbons from a C18 aldehyde substrate and thus has bona fide decarbonylase activity similar to that of dmCYP4G1/2. The data support the hypothesis that the coevolution of multiple mechanisms, including cuticular barriers, has occurred in highly pyrethroid-resistant An gambiae.


Assuntos
Anopheles/metabolismo , Sistema Enzimático do Citocromo P-450/fisiologia , Hidrocarbonetos/metabolismo , Resistência a Inseticidas , Animais , Catálise , Feminino , Nitrilas/farmacocinética , Piretrinas/farmacocinética
19.
Bull Environ Contam Toxicol ; 102(6): 861-866, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-30937494

RESUMO

Shrimp of Farfantepenaeus californiensis (78 groups) and Litopenaeus stylirostris (14 groups) were caught in the northwestern fishing zones in Mexico during the 2014-2015 fishing season (September-February); both shrimp species have high commercial value. Muscle, hepatopancreas and exoskeleton were analyzed to determine their metal contents. For F. californiensis, the highest Cd, Pb and Zn contents were determined in specimens caught off the State of Baja California Sur (BCS) with 22.4 ± 8.9 (hepatopancreas), 2.83 ± 4.63 (muscle), and 748.5 ± 1567 (muscle) µg/g, in the regions off Mulegé, Los Cabos and Los Cabos, respectively. For L. stylirostris, the fishing zone of Comundú (BCS) showed higher Cd (12.3 ± 11.5 µg/g), Cu (569.1 ± 646.5 µg/g) and Zn (549.7 ± 400.7 µg/g) contents; all values were determined in the hepatopancreas. Regarding the hazard quotient and total hazard quotient calculated in this study, the consumption of marine shrimp caught off NW Mexico does not represent a risk to human health (both < 1).


Assuntos
Contaminação de Alimentos , Metais/análise , Penaeidae/química , Alimentos Marinhos , Animais , Monitoramento Ambiental , Hepatopâncreas/química , Humanos , México , Músculos/química , Medição de Risco
20.
Horm Behav ; 98: 77-87, 2018 02.
Artigo em Inglês | MEDLINE | ID: mdl-29269179

RESUMO

The present study assessed the participation of membrane G-protein coupled estrogen receptor 1 (GPER-1) and gonadotropin releasing hormone 1 (GnRH-1) receptor in the display of lordosis induced by intracerebroventricular (icv) administration of G1, a GPER-1 agonist, and by unesterified 17ß-estradiol (free E2). In addition, we assessed the participation of both estrogen and progestin receptors in the lordosis behavior induced by G1 in ovariectomized (OVX), E2-benzoate (EB)-primed rats. In Experiment 1, icv injection of G1 induced lordosis behavior at 120 and 240min. In Experiment 2, icv injection of the GPER-1 antagonist G15 significantly reduced lordosis behavior induced by either G1 or free E2. In addition, Antide, a GnRH-1 receptor antagonist, significantly depressed G1 facilitation of lordosis behavior in OVX, EB-primed rats. Similarly, icv injection of Antide blocked the stimulatory effect of E2 on lordosis behavior. In Experiment 3, systemic injection of either tamoxifen or RU486 significantly reduced lordosis behavior induced by icv administration of G1 in OVX, EB-primed rats. The results suggest that GnRH release activates both estrogen and progestin receptors and that this activation is important in the chain of events leading to the display of lordosis behavior in response to activation of GPER-1 in estrogen-primed rats.


Assuntos
Estradiol/farmacologia , Postura/fisiologia , Receptores de Estrogênio/fisiologia , Receptores Acoplados a Proteínas G/agonistas , Receptores LHRH/fisiologia , Receptores de Progesterona/fisiologia , Comportamento Sexual Animal/efeitos dos fármacos , Animais , Feminino , Antagonistas de Hormônios/farmacologia , Mifepristona/farmacologia , Oligopeptídeos/farmacologia , Ratos , Ratos Sprague-Dawley , Comportamento Sexual Animal/fisiologia , Tamoxifeno/farmacologia
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