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1.
Nature ; 629(8012): 555-560, 2024 May.
Artículo en Inglés | MEDLINE | ID: mdl-38658758

RESUMEN

The tokamak approach, utilizing a toroidal magnetic field configuration to confine a hot plasma, is one of the most promising designs for developing reactors that can exploit nuclear fusion to generate electrical energy1,2. To reach the goal of an economical reactor, most tokamak reactor designs3-10 simultaneously require reaching a plasma line-averaged density above an empirical limit-the so-called Greenwald density11-and attaining an energy confinement quality better than the standard high-confinement mode12,13. However, such an operating regime has never been verified in experiments. In addition, a long-standing challenge in the high-confinement mode has been the compatibility between a high-performance core and avoiding large, transient edge perturbations that can cause very high heat loads on the plasma-facing-components in tokamaks. Here we report the demonstration of stable tokamak plasmas with a line-averaged density approximately 20% above the Greenwald density and an energy confinement quality of approximately 50% better than the standard high-confinement mode, which was realized by taking advantage of the enhanced suppression of turbulent transport granted by high density-gradients in the high-poloidal-beta scenario14,15. Furthermore, our experimental results show an integration of very low edge transient perturbations with the high normalized density and confinement core. The operating regime we report supports some critical requirements in many fusion reactor designs all over the world and opens a potential avenue to an operating point for producing economically attractive fusion energy.

3.
Cryobiology ; 115: 104888, 2024 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-38508357

RESUMEN

The experiment evaluated the effect of adding cholesterol-loaded cyclodextrin (CLC) to Prochilodus lineatus fish (Curimata) semen on post-thaw sperm quality. Twelve adult fish were used for sperm collection after induced spermiation with carp pituitary gland. The semen was diluted and treated with CLC in concentrations of 0 (control), 0.5, 1.0, 2.0, 3.0, and 4.0 mg for 120 × 106 spermatozoa/ml, loaded in 0.5 ml straws, packaged and placed in dry vapor vessel cylinders for 24 h before being submerged in liquid nitrogen for storage. The samples were thawed in a water bath at 60 °C for 8 s, and the sperm parameters evaluated were motility, activation duration, longevity, plasma membrane integrity, and morphology. Data were tested for normal distribution and ANOVA, followed by Friedman test (P < 0.05). Spermatozoa treated with CLC displayed higher motility than the control (P < 0.05). The duration of sperm activation was longer in sperm treated with 0.5, 1.0, and 2.0 mg of CLC than in control (P < 0.05). The membrane integrity was higher in sperm treated with 0.5, 1.0, 2.0, and 3.0 mg of CLC than in control and four mg-treated samples (P < 0.05). The sperm longevity and morphology alterations did not differ between treatments (P > 0.05). Adding 0.5, 1.0, or 2.0 mg of CLC in Prochilodus lineatus semen before cryopreservation improves sperm motility and membrane integrity.


Asunto(s)
Colesterol , Criopreservación , Crioprotectores , Ciclodextrinas , Preservación de Semen , Motilidad Espermática , Espermatozoides , Animales , Masculino , Criopreservación/métodos , Criopreservación/veterinaria , Preservación de Semen/métodos , Preservación de Semen/veterinaria , Motilidad Espermática/efectos de los fármacos , Ciclodextrinas/farmacología , Ciclodextrinas/química , Espermatozoides/efectos de los fármacos , Colesterol/farmacología , Crioprotectores/farmacología , Membrana Celular/efectos de los fármacos , Characiformes , Análisis de Semen
4.
Proc Biol Sci ; 290(2010): 20232024, 2023 Nov 08.
Artículo en Inglés | MEDLINE | ID: mdl-37935365

RESUMEN

Foraging animals commonly choose whether to find new food (as 'producers') or scavenge from others (as 'scroungers'), and this decision has ecological and evolutionary consequences. Understanding these tactic decisions is particularly vital for naturally occurring producer-scrounger systems of economic importance, because they determine the system's productivity and resilience. Here, we investigate how individuals' traits predict tactic decisions, and the consistency and pay-offs of these decisions, in the remarkable mutualism between humans (Homo sapiens) and greater honeyguides (Indicator indicator). Honeyguides can either guide people to bees' nests and eat the resulting beeswax (producing), or scavenge beeswax (scrounging). Our results suggest that honeyguides flexibly switched tactics, and that guiding yielded greater access to the beeswax. Birds with longer tarsi scrounged more, perhaps because they are more competitive. The lightest females rarely guided, possibly to avoid aggression, or because genetic matrilines may affect female body mass and behaviour in this species. Overall, aspects of this producer-scrounger system probably increase the productivity and resilience of the associated human-honeyguide mutualism, because the pay-offs incentivize producing, and tactic-switching increases the pool of potential producers. Broadly, our findings suggest that even where tactic-switching is prevalent and producing yields greater pay-offs, certain phenotypes may be predisposed to one tactic.


Asunto(s)
Aves , Simbiosis , Humanos , Femenino , Abejas , Animales , Agresión , Evolución Biológica , Alimentos
5.
Phys Rev Lett ; 131(7): 075101, 2023 Aug 18.
Artículo en Inglés | MEDLINE | ID: mdl-37656860

RESUMEN

The fusion-born alpha particle heating in magnetically confined fusion machines is a high priority subject for studies. The self-heating of thermonuclear fusion plasma by alpha particles was observed in recent deuterium-tritium (D-T) experiments on the joint European torus. This observation was possible by conducting so-called "afterglow" experiments where transient high fusion yield was achieved with neutral beam injection as the only external heating source, and then termination of the heating at peak performance. This allowed the first direct evidence for electron heating of plasmas by fusion-born alphas to be obtained. Interpretive transport modeling of the relevant D-T and reference deuterium discharges is consistent with the alpha particle heating observation.

6.
Microb Ecol ; 83(1): 202-215, 2022 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-33758979

RESUMEN

Exposure to environmental stressors, an increasingly recurring event in natural communities due to anthropogenic-induced environmental change, profoundly impacts disease emergence and spread. One mechanism through which this occurs is through stress-induced immunosuppression increasing disease susceptibility, prevalence, intensity and reactivation in hosts. We experimentally evaluated how exposure to stressors affected both the physiology of avian hosts and the prevalence of the zoonotic bacteria Borrelia burgdorferi sensu lato (s.l.), in two model species-the blackbird Turdus merula and the robin Erithacus rubecula captured in the wild, using xenodiagnoses and analysis of skin biopsies and blood. Although exposure to stressors in captivity induced physiological stress in birds (increased the number of circulating heterophils), there was no evidence of increased infectivity to xenodiagnostic ticks. However, Borrelia detection in the blood for both experimental groups of blackbirds was higher by the end of the captivity period. The infectivity and efficiency of transmission were higher for blackbirds than robins. When comparing different methodologies to determine infection status, xenodiagnosis was a more sensitive method than skin biopsies and blood samples, which could be attributed to mild levels of infection in these avian hosts and/or dynamics and timing of Borrelia infection relapses and redistribution in tissues.


Asunto(s)
Grupo Borrelia Burgdorferi , Borrelia burgdorferi , Borrelia , Ixodes , Enfermedad de Lyme , Pájaros Cantores , Animales , Grupo Borrelia Burgdorferi/fisiología , Ixodes/microbiología , Enfermedad de Lyme/microbiología , Enfermedad de Lyme/veterinaria , Pájaros Cantores/microbiología
7.
J Virol ; 92(11)2018 06 01.
Artículo en Inglés | MEDLINE | ID: mdl-29563290

RESUMEN

Highly pathogenic influenza A viruses (IAV) from avian hosts were first reported to directly infect humans 20 years ago. However, such infections are rare events, and our understanding of factors promoting or restricting zoonotic transmission is still limited. One accessory protein of IAV, PB1-F2, was associated with pathogenicity of pandemic and zoonotic IAV. This short (90-amino-acid) peptide does not harbor an enzymatic function. We thus identified host factors interacting with H5N1 PB1-F2, which could explain its importance for virulence. PB1-F2 binds to HCLS1-associated protein X1 (HAX-1), a recently identified host restriction factor of the PA subunit of IAV polymerase complexes. We demonstrate that the PA of a mammal-adapted H1N1 IAV is resistant to HAX-1 imposed restriction, while the PA of an avian-origin H5N1 IAV remains sensitive. We also showed HAX-1 sensitivity for PAs of A/Brevig Mission/1/1918 (H1N1) and A/Shanghai/1/2013 (H7N9), two avian-origin zoonotic IAV. Inhibition of H5N1 polymerase by HAX-1 can be alleviated by its PB1-F2 through direct competition. Accordingly, replication of PB1-F2-deficient H5N1 IAV is attenuated in the presence of large amounts of HAX-1. Mammal-adapted H1N1 and H3N2 viruses do not display this dependence on PB1-F2 for efficient replication in the presence of HAX-1. We propose that PB1-F2 plays a key role in zoonotic transmission of avian H5N1 IAV into humans.IMPORTANCE Aquatic and shore birds are the natural reservoir of influenza A viruses from which the virus can jump into a variety of bird and mammal host species, including humans. H5N1 influenza viruses are a good model for this process. They pose an ongoing threat to human and animal health due to their high mortality rates. However, it is currently unclear what restricts these interspecies jumps on the host side or what promotes them on the virus side. Here we show that a short viral peptide, PB1-F2, helps H5N1 bird influenza viruses to overcome a human restriction factor of the viral polymerase complex HAX-1. Interestingly, we found that human influenza A virus polymerase complexes are already adapted to HAX-1 and do not require this function of PB1-F2. We thus propose that a functional full-length PB1-F2 supports direct transmission of bird viruses into humans.


Asunto(s)
Proteínas Adaptadoras Transductoras de Señales/metabolismo , Subtipo H5N1 del Virus de la Influenza A/patogenicidad , Gripe Aviar/transmisión , Gripe Humana/transmisión , Proteínas Virales/metabolismo , Replicación Viral/genética , Células A549 , Proteínas Adaptadoras Transductoras de Señales/genética , Animales , Aves , Sistemas CRISPR-Cas , Línea Celular Tumoral , Perros , Técnicas de Inactivación de Genes , Células HEK293 , Células HeLa , Humanos , Subtipo H1N1 del Virus de la Influenza A/metabolismo , Subtipo H3N2 del Virus de la Influenza A/metabolismo , Subtipo H5N1 del Virus de la Influenza A/metabolismo , Subtipo H7N9 del Virus de la Influenza A/metabolismo , Gripe Aviar/virología , Gripe Humana/virología , Pulmón/virología , Células de Riñón Canino Madin Darby , Unión Proteica , Proteínas Virales/genética , Zoonosis/transmisión , Zoonosis/virología
8.
Trop Anim Health Prod ; 50(5): 1089-1097, 2018 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-29429115

RESUMEN

Staphylococcus aureus is among the microorganisms more frequently associated with subclinical bovine mastitis. S. aureus may produce several virulence factors. This study aimed at determining the frequency of virulence factors such as enterotoxins, toxic shock syndrome toxin 1, and ica adhesion genes. In addition, we assessed antimicrobial drug resistance in S. aureus isolated from clinical and subclinical cases of mastitis. A total of 88 cows with clinical or subclinical mastitis were sampled, resulting in 38 S. aureus isolates, from which 25 (65.78%) carried toxin genes, including seb, sec, sed, tst, and icaD adhesion gene. These S. aureus isolates belong to 21 ribotypes and three S. aureus strains belonged to the same ribotype producing ica adhesion gene. Approximately 90% of S. aureus strains obtained in our study demonstrated multiple resistance to different antimicrobial agents. The most efficacious antimicrobial agents against the isolates were gentamicin, amoxicillin, and norfloxacin. Gentamicin was the most efficacious agent inhibiting 78.95% of the S. aureus isolates. The least efficacious were penicillin, streptomycin, and ampicillin. Our results can help in understanding the relationship between virulence factors and subclinical mastitis caused by S. aureus. Further research about diversity of S. aureus isolates and genes responsible for the pathogenicity of subclinical mastitis is essential.


Asunto(s)
Toxinas Bacterianas/genética , Biopelículas , Enterotoxinas/genética , Mastitis Bovina/microbiología , Infecciones Estafilocócicas/veterinaria , Staphylococcus aureus/genética , Superantígenos/genética , Amoxicilina/administración & dosificación , Animales , Brasil , Bovinos , Femenino , Gentamicinas/administración & dosificación , Norfloxacino/administración & dosificación , Staphylococcus aureus/aislamiento & purificación , Virulencia , Factores de Virulencia/genética
9.
Genet Mol Res ; 16(1)2017 Mar 22.
Artículo en Inglés | MEDLINE | ID: mdl-28340272

RESUMEN

Methodologies using restricted maximum likelihood/best linear unbiased prediction (REML/BLUP) in combination with sequential path analysis in maize are still limited in the literature. Therefore, the aims of this study were: i) to use REML/BLUP-based procedures in order to estimate variance components, genetic parameters, and genotypic values of simple maize hybrids, and ii) to fit stepwise regressions considering genotypic values to form a path diagram with multi-order predictors and minimum multicollinearity that explains the relationships of cause and effect among grain yield-related traits. Fifteen commercial simple maize hybrids were evaluated in multi-environment trials in a randomized complete block design with four replications. The environmental variance (78.80%) and genotype-vs-environment variance (20.83%) accounted for more than 99% of the phenotypic variance of grain yield, which difficult the direct selection of breeders for this trait. The sequential path analysis model allowed the selection of traits with high explanatory power and minimum multicollinearity, resulting in models with elevated fit (R2 > 0.9 and ε < 0.3). The number of kernels per ear (NKE) and thousand-kernel weight (TKW) are the traits with the largest direct effects on grain yield (r = 0.66 and 0.73, respectively). The high accuracy of selection (0.86 and 0.89) associated with the high heritability of the average (0.732 and 0.794) for NKE and TKW, respectively, indicated good reliability and prospects of success in the indirect selection of hybrids with high-yield potential through these traits. The negative direct effect of NKE on TKW (r = -0.856), however, must be considered. The joint use of mixed models and sequential path analysis is effective in the evaluation of maize-breeding trials.


Asunto(s)
Modelos Genéticos , Zea mays/genética , Cruzamientos Genéticos , Grano Comestible/genética , Técnicas de Genotipaje/métodos , Funciones de Verosimilitud , Fitomejoramiento/métodos , Probabilidad , Sitios de Carácter Cuantitativo , Análisis de Regresión , Reproducibilidad de los Resultados , Selección Genética
10.
Genet Mol Res ; 16(3)2017 Aug 31.
Artículo en Inglés | MEDLINE | ID: mdl-28873210

RESUMEN

Genetic improvement is essential to achieve increments in maize (Zea mays L.) grain yield components. It may be obtained through crosses, which enable to exploit the effects of intervarietal heterosis, allelic complementarity, as well as gene actions and effects. This study estimated the components of variance and genetic parameters (REML/BLUP) of an intervarietal diallel to select and predict the best genotypes for maize yield components. The experimental design was randomized blocks containing 60 intervarietal maize hybrids arranged in three repetitions. They were obtained through intervarietal crosses and evaluated in a diallel scheme, where 14 open-pollinated varieties were designated as parentals. Thus, 10 crosses were performed for each hybrid combination to obtain the number of seeds necessary for the competition test. The measured traits were: grain volume relative index, the mass of one hundred grains, and grain yield. The male parents and the additive genetic fraction were determinants for grain volume relative index. Mass of one hundred grains and grain yield were defined by the specific combining ability, and female parents revealed low narrow sense heritability. The female parent Taquarão and male parent Argentino Amarelo presented the best general combining abilities for the measured traits. The specific combining abilities were expressed for crosses AL 25 x Dente de Ouro Roxo, AL 25 x BRS Pampeano, and Taquarão x Argentino Branco. Genetic estimates and predictions were consistent and applicable to breeding programs and could be applied in future quantitative genetic studies of maize.


Asunto(s)
Hibridación Genética , Modelos Genéticos , Fitomejoramiento/métodos , Polimorfismo Genético , Zea mays/genética , Alelos , Genotipo , Carácter Cuantitativo Heredable , Semillas/genética , Semillas/crecimiento & desarrollo , Zea mays/crecimiento & desarrollo
11.
Genet Mol Res ; 16(2)2017 Jun 20.
Artículo en Inglés | MEDLINE | ID: mdl-28653744

RESUMEN

The REML/BLUP statistics are analyses that can be used as selective criteria in the routine of maize breeding programs. The present study aims to determine the genetic potential in crosses of landrace populations applying the REML/BLUP methodology, and to identify populations for the synthesis of new populations and intrapopulation selection for family farming systems, as well as genetic constitutions for use in maize breeding programs. Nine top cross hybrids obtained in the 2012/2013 harvest were evaluated along with their testator, the landraces used as parents, and four commercial hybrids, in a randomized block design, with information taken from the average of each plot. The evaluated traits were: leaf angle, number of ramifications of the tassel, spike insertion height, plant height, spike diameter, number of grains per spike, mass of grains per spike, spike mass, spike length, prolificity, mass of one hundred grains, and grain yield per plot. The data were analyzed using the Selegen-REML/BLUP software. The top cross hybrids Cateto Branco x Planalto, Amarelão x Planalto and the population Cateto Branco are ranked among the ten best crosses, simultaneously, for the traits: leaf angle, number of ramifications of the tassel, spike insertion height, and plant height (Cateto Branco x Planalto), and leaf angle, spike insertion height, and plant height (Amarelão x Planalto and Cateto Branco). The top cross hybrids Criolão x Planalto, Branco 8 Carreiras x Planalto, Caiano Rajado x Planalto, Amarelão x Planalto, Branco Roxo Índio x Planalto stand out for their high genotypic value of the individual BLUP mean components among the ten best genotypes for grain yield, and by combining three or more traits of interest together, being, for effects of selection, the most indicated.


Asunto(s)
Cruzamiento/métodos , Cruzamientos Genéticos , Zea mays/genética , Carácter Cuantitativo Heredable
12.
Trop Anim Health Prod ; 49(8): 1557-1576, 2017 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-28884331

RESUMEN

Latin America is the definition of the American group, where languages of Latin origin are spoken, including countries in South, Central, and North America. Paratuberculosis is a gastrointestinal contagious chronic disease that affects ruminants, whose etiological agent is the bacilli Mycobacterium avium subsp. paratuberculosis (MAP). Paratuberculosis is characterized by intermittent diarrhea, decreased milk production, dehydration, and progressive weight loss and is possibly involved in Crohn's disease, a human intestinal disease. MAP is resistant to environmental factors, pasteurization, and water disinfection, which coupled with the subclinical-clinical nature of the disease, and makes paratuberculosis a relevant socioeconomic and public health issue, justifying the descriptive review of research on the disease carried out in Latin American countries. A survey of articles, published until September 2016, on the Scopus database, PubMed, Agris, and Science Direct, about detection of the agent and the disease in Latin America, without restrictions to the date of the research was performed. The keywords were as follows: "paratuberculosis," "Mycobacterium avium subsp. paratuberculosis," "cattle," "milk," "wildlife," "goat," "ovine," "dairy," and the name of each country in English. Studies found from nine of the 20 Latin America countries, 31 related to Brazil, 17 to Argentina, 14 to Chile, eight to Colombia, six to Mexico, two to Peru, two to Venezuela, and one to Panama and to Bolivia, each. The agent was detected in cattle, goats, sheep, domesticated water buffalo, and wild animals. Microbiological culture, PCR, and ELISA were the frequent techniques. The small number of studies may result in overestimation or underestimation of the real scenario.


Asunto(s)
Mycobacterium avium subsp. paratuberculosis , Paratuberculosis/epidemiología , Animales , Humanos , América Latina/epidemiología , Paratuberculosis/microbiología
13.
Int J Cosmet Sci ; 38(2): 109-19, 2016 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-25923295

RESUMEN

Nowadays, the consumers around the world are increasingly focused on health and beauty. The renewed consumer interest in natural cosmetic products creates the demand for new products and reformulated others with botanical and functional ingredients. In cosmetic products, essential oils (EOs) play a major role as fragrance ingredients. They can optimize its proprieties and preservation, as well as the marketing image of the final product. Microencapsulation of EOs can protect and prevent the loss of volatile aromatic ingredients and improve the controlled release and stability of this core materials. The importance of EOs for cosmetic industry and its microencapsulation was reviewed in this study. Also a briefly introduction about the preparation of microparticles was presented. Some of the most important and usual microencapsulation techniques of EOs, as well as the conventional encapsulating agents, were discussed. Despite the fact that microencapsulation of EOs is a very promising and extremely attractive application area for cosmetic industry, further basic research needs to be carried out, for a better understanding of the biofunctional activities of microencapsulated EOs and its release modulation, as well as the effects of others cosmetic ingredients and the storage time in the microparticles properties.


Asunto(s)
Cosméticos , Higiene , Aceites Volátiles/administración & dosificación , Emulsiones
14.
J Dairy Sci ; 97(7): 4111-4, 2014 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-24797534

RESUMEN

Mycobacterium avium ssp. paratuberculosis (MAP) is the etiologic agent of paratuberculosis and it potentially plays a role in Crohn's disease. In humans, the main route of transmission of MAP might be the intake of contaminated milk and dairy products. Considering that MAP has already been detected in many types of cheese in different counties, and that Coalho cheese is an important dairy product in northeastern Brazil, the aim of this study was to report the first detection of MAP in retail Coalho cheese in Brazil by PCR and culture. Of 30 retail Coalho cheese samples, 3 (10%) amplified fragments of a similar size to that expected (626 bp) were obtained and viable MAP was recovered by culture from 1 (3.3%) sample. The DNA from the positive culture sample was sequenced and showed 99% identity with the insertion sequence IS900 deposited in GenBank. It was possible to identify the presence of MAP-specific DNA in the analyzed samples for the first time in Brazil, and to recover viable cells from retail Coalho cheese.


Asunto(s)
Queso/microbiología , Mycobacterium avium subsp. paratuberculosis/aislamiento & purificación , Animales , Brasil , Recuento de Colonia Microbiana , Elementos Transponibles de ADN , ADN Bacteriano/genética , Datos de Secuencia Molecular , Mycobacterium avium subsp. paratuberculosis/genética , Reacción en Cadena de la Polimerasa , Análisis de Secuencia de ADN
15.
J Mol Model ; 30(8): 268, 2024 Jul 16.
Artículo en Inglés | MEDLINE | ID: mdl-39012396

RESUMEN

CONTEXT: In the realm of quantum chemistry, the accurate prediction of electronic structure and properties of nanostructures remains a formidable challenge. Density functional theory (DFT) and density matrix renormalization group (DMRG) have emerged as two powerful computational methods for addressing electronic correlation effects in diverse molecular systems. We compare ground-state energies ( e 0 ), density profiles ( n ), and average entanglement entropies ( S ¯ ) in metals, insulators and at the transition from metal to insulator, in homogeneous, superlattices, and harmonically confined chains described by the fermionic one-dimensional Hubbard model. While for the homogeneous systems, there is a clear hierarchy between the deviations, D % ( S ¯ ) < D % ( e 0 ) < D ¯ % ( n ) , and all the deviations decrease with the chain size; for superlattices and harmonic confinement, the relation among the deviations is less trivial and strongly dependent on the superlattice structure and the confinement strength considered. For the superlattices, in general, increasing the number of impurities in the unit cell represents lower precision in the DFT calculations. For the confined chains, DFT performs better for metallic phases, while the highest deviations appear for the Mott and band-insulator phases. This work provides a comprehensive comparative analysis of these methodologies, shedding light on their respective strengths, limitations, and applications. METHODS: The DFT calculations were performed using the standard Kohn-Sham scheme within the BALDA approach. It integrated the numerical Bethe-Ansatz (BA) solution of the Hubbard model as the homogeneous density functional within a local-density approximation (LDA) for the exchange-correlation energy. The DMRG algorithms were implemented using the ITensor library, which is based on the matrix product states (MPS) ansatz. The calculations were performed until the energy reaches convergence of at least 10 - 8 .

16.
Environ Microbiol ; 15(2): 386-97, 2013 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-22882497

RESUMEN

Birds are important in the ecology of Borrelia burgdorferi sensu lato (s.l.) because they are important hosts for vector tick immature stages and are known reservoirs for some Borrelia genospecies. The aim of our study was to assess the role of common passerine bird species as reservoirs for B. burgdorferi s.l. in Western Europe. We surveyed birds in enzootic areas in Portugal, where no information is available for birds as reservoirs for this aetiologic agent and where B. lusitaniae, for which few reservoirs have been identified, is the dominant genospecies. Twenty-three birds (2.9%), including Turdus merula, T. philomelos, Parus major and Fringilla coelebs harboured infected ticks, but only Turdus sp. harboured infected tick larvae. In one study area, although B. lusitaniae was dominant in questing Ixodes ricinus, no ticks feeding on birds were infected with this genospecies, and B. valaisiana was the dominant genospecies in I. ricinus larvae feeding on birds. In the other area ticks collected from birds were mainly I. frontalis which were infected with B. turdi. Two skin biopsies (4.2%) from two T. merula were positive, one for B. valaisiana and the other for B. turdi. This is the first report for B. turdi in Western Europe.


Asunto(s)
Borrelia burgdorferi/fisiología , Borrelia/fisiología , Reservorios de Enfermedades , Infestaciones Ectoparasitarias/veterinaria , Passeriformes/microbiología , Passeriformes/parasitología , Garrapatas/microbiología , Animales , Borrelia/clasificación , Borrelia/genética , Borrelia burgdorferi/genética , Infestaciones Ectoparasitarias/microbiología , Interacciones Huésped-Patógeno , Enfermedad de Lyme/transmisión , Datos de Secuencia Molecular , Filogenia , Portugal , ARN Ribosómico 23S/genética , ARN Ribosómico 5S/genética
17.
J Viral Hepat ; 20(6): 414-21, 2013 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-23647958

RESUMEN

Several new direct-acting antiviral (DAA) drugs are in development for chronic hepatitis C viral (HCV) infection, and NS3-NS4A serine protease and the NS5B RNA-dependent RNA polymerase have been the major targets. HCV variants displaying drug-resistant phenotypes have been observed both in vitro and during clinical trials. Our aim was to characterize amino acid changes at positions previously associated with resistance in protease (NS3) and polymerase (NS5B) regions from treatment-naïve HCV patients infected with genotypes 1a, 1b and 3a. All 1383 NS3 protease sequences (genotype 1a = 680, 1b = 498 and 3a = 205) and 806 NS5B polymerase sequences (genotypes 1a = 471, 1b = 329, 3a = 6) were collected from Los Alamos databank. Genotype 3a protease sequences showed the typical low-level resistance mutation V36L. NS3 sequences from other genotypes presented mutations on positions 36, 39, 41, 43, 54, 80, 109, 155 and 168 in a frequency lower than 2%, except for the mutation Q80R found in 35% of genotype 1a isolates. Polymerase sequences from genotype 3a patients showed five typical mutations: L419I, I424V, I482L, V499A and S556G. Two positions presented high polymorphism in the NS5B region from genotype 1a (V499A) and genotype 1b (C316N) subjects. Our results demonstrated a natural profile of genotype 3a that can be associated with the pre-existence of HCV variants resistant to first-generation protease inhibitors and to non-nucleoside polymerase inhibitors. Likewise, genotype 1b isolates and genotype 1a sequences exhibited pre-existing mutations associated with resistance to Palm II and Thumb I polymerase inhibitors, respectively.


Asunto(s)
Farmacorresistencia Viral , Hepacivirus/genética , Inhibidores de Proteasas/farmacología , Proteínas no Estructurales Virales/genética , Sustitución de Aminoácidos , Antivirales/farmacología , Secuencia de Bases , Dominio Catalítico , Bases de Datos Genéticas , Genotipo , Hepacivirus/efectos de los fármacos , Hepacivirus/enzimología , Hepatitis C Crónica/tratamiento farmacológico , Humanos , Tasa de Mutación , Proteínas no Estructurales Virales/antagonistas & inhibidores
18.
Parasitol Res ; 112(5): 1903-12, 2013 May.
Artículo en Inglés | MEDLINE | ID: mdl-23430359

RESUMEN

Ticks consume resources from their hosts shaping their life-history traits and are vectors of many zoonotic pathogens. Several studies have focused on the health effects of blood-sucking ectoparasites on avian hosts, but there is limited information on the effects of ticks on adult and sub-adult birds, which may actively avoid ticks and are likely to present low infestation intensities. We evaluated the effects of the presence of feeding ticks and intensity of infestation on health variables of avian hosts. We also evaluated whether these variables were affected by tick infection by Borrelia burgdorferi sensu lato (s.l.) and by the presence of Borrelia infection on the birds' skin. Presence of parasite association among ticks, haemosporidea and Borrelia within the bird-host was also tested. We found that infestation by ticks significantly increased heterophyl/lymphocyte ratio in Turdus merula suggesting increased stress. This was especially evident at high infestation intensities when a significant decrease in body mass and body condition (body mass corrected for size) was also observed. Erithacus rubecula infested with more than 10 larvae tended to have lower haematocrit and blood haemoglobin. Plasma globulin concentration in T. merula tended to be affected by the presence of attached ticks and their infection with Borrelia, but this depended on the age of the bird. No association was detected among ticks, haemosporidea and Borrelia infection. We showed that ticks have detrimental effects on their avian hosts even under natural infestation conditions and that confirmed Borrelia reservoir hosts may also present symptoms of infection, though these may be subtle.


Asunto(s)
Enfermedades de las Aves/fisiopatología , Aves , Borrelia burgdorferi/patogenicidad , Enfermedad de Lyme/veterinaria , Infestaciones por Garrapatas/veterinaria , Garrapatas , Animales , Vectores Arácnidos/parasitología , Enfermedades de las Aves/parasitología , Enfermedades de las Aves/transmisión , Aves/microbiología , Aves/parasitología , Reservorios de Enfermedades/veterinaria , Femenino , Enfermedad de Lyme/fisiopatología , Enfermedad de Lyme/transmisión , Masculino , Infestaciones por Garrapatas/parasitología , Infestaciones por Garrapatas/patología , Infestaciones por Garrapatas/transmisión , Garrapatas/microbiología , Garrapatas/parasitología
19.
Pulmonology ; 29 Suppl 4: S36-S43, 2023 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-34544672

RESUMEN

BACKGROUND: Tuberculosis (TB) incidence declined in Portugal in recent decades, but trends differ between regions and population subgroups. We investigated these differences to inform prevention and control programmes. METHODS: We extracted TB notifications from the Portuguese National TB Surveillance System (SVIG-TB) in 2010-2017, disaggregated by region, age group, nationality and HIV status. We calculated notification rates using denominators from the Portuguese National Institute of Statistics and the Joint United Nations Programme on HIV/AIDS and performed stratified time series analysis. We estimated interannual decline percentages and 95% confidence intervals (CI) using Poisson and binomial negative regression models. RESULTS: The overall TB notification rate decreased from 25.7 to 17.5/100,000 population from 2010 to 2017 (5.2%/year) in Portugal. Interannual decline did not differ significantly between regions, but it was smaller amongst non-Portuguese nationals (-1.57% [CI: -4.79%, 1.75%] vs -5.85% [CI: -6.98%, -4.70%] in Portuguese nationals); children under five years of age (+1.77% [CI: -4.61%, 8.58%] vs -5.38% [CI: -6.33%, -4.42%] in other age groups); and HIV-negative people (-6.47% [CI: -9.10%, -3.77%] vs -11.29% [CI; -17.51%, -4.60%] in HIV-positive). CONCLUSIONS: The decline in TB notification rates in Portugal during the study period has been steady. However, the decline amongst non-Portuguese nationals, children under five years of age and non-infected-HIV patients was lower. No significant differences were observed between regions. Changes in TB epidemiology in specific risk groups and geographical areas should be closely monitored to achieve the objectives of the End TB Strategy. We recommend intensifying screening of TB in the subpopulations identified.


Asunto(s)
Infecciones por VIH , Tuberculosis , Niño , Humanos , Preescolar , Portugal/epidemiología , Infecciones por VIH/epidemiología , Tuberculosis/epidemiología , Tuberculosis/diagnóstico , Factores de Riesgo , Incidencia
20.
Int J Tuberc Lung Dis ; 27(7): 506-519, 2023 Jul 01.
Artículo en Inglés | MEDLINE | ID: mdl-37353868

RESUMEN

BACKGROUND: Adverse effects (AE) to TB treatment cause morbidity, mortality and treatment interruption. The aim of these clinical standards is to encourage best practise for the diagnosis and management of AE.METHODS: 65/81 invited experts participated in a Delphi process using a 5-point Likert scale to score draft standards.RESULTS: We identified eight clinical standards. Each person commencing treatment for TB should: Standard 1, be counselled regarding AE before and during treatment; Standard 2, be evaluated for factors that might increase AE risk with regular review to actively identify and manage these; Standard 3, when AE occur, carefully assessed and possible allergic or hypersensitivity reactions considered; Standard 4, receive appropriate care to minimise morbidity and mortality associated with AE; Standard 5, be restarted on TB drugs after a serious AE according to a standardised protocol that includes active drug safety monitoring. In addition: Standard 6, healthcare workers should be trained on AE including how to counsel people undertaking TB treatment, as well as active AE monitoring and management; Standard 7, there should be active AE monitoring and reporting for all new TB drugs and regimens; and Standard 8, knowledge gaps identified from active AE monitoring should be systematically addressed through clinical research.CONCLUSION: These standards provide a person-centred, consensus-based approach to minimise the impact of AE during TB treatment.


Asunto(s)
Efectos Colaterales y Reacciones Adversas Relacionados con Medicamentos , Hipersensibilidad , Tuberculosis , Humanos , Tuberculosis/diagnóstico , Tuberculosis/tratamiento farmacológico , Efectos Colaterales y Reacciones Adversas Relacionados con Medicamentos/etiología , Personal de Salud
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