Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 1.158
Filtrar
Mais filtros

Intervalo de ano de publicação
1.
Nature ; 2024 Jun 11.
Artigo em Inglês | MEDLINE | ID: mdl-38862026

RESUMO

Human spaceflight has historically been managed by government agencies, such as in the NASA Twins Study1, but new commercial spaceflight opportunities have opened spaceflight to a broader population. In 2021, the SpaceX Inspiration4 mission launched the first all-civilian crew to low Earth orbit, which included the youngest American astronaut (aged 29), new in-flight experimental technologies (handheld ultrasound imaging, smartwatch wearables and immune profiling), ocular alignment measurements and new protocols for in-depth, multi-omic molecular and cellular profiling. Here we report the primary findings from the 3-day spaceflight mission, which induced a broad range of physiological and stress responses, neurovestibular changes indexed by ocular misalignment, and altered neurocognitive functioning, some of which match those of long-term spaceflight2, but almost all of which did not differ from baseline (pre-flight) after return to Earth. Overall, these preliminary civilian spaceflight data suggest that short-duration missions do not pose a significant health risk, and moreover present a rich opportunity to measure the earliest phases of adaptation to spaceflight in the human body at anatomical, cellular, physiological and cognitive levels. Finally, these methods and results lay the foundation for an open, rapidly expanding biomedical database for astronauts3, which can inform countermeasure development for both private and government-sponsored space missions.

2.
Nature ; 2024 Jun 11.
Artigo em Inglês | MEDLINE | ID: mdl-38862027

RESUMO

The recent acceleration of commercial, private, and multi-national spaceflight has created an unprecedented level of activity in low Earth orbit (LEO), concomitant with the highest-ever number of crewed missions entering space and preparations for exploration-class (>1 year) missions. Such rapid advancement into space from many new companies, countries, and space-related entities has enabled a"Second Space Age." This new era is also poised to leverage, for the first time, modern tools and methods of molecular biology and precision medicine, thus enabling precision aerospace medicine for the crews. The applications of these biomedical technologies and algorithms are diverse, encompassing multi-omic, single-cell, and spatial biology tools to investigate human and microbial responses to spaceflight. Additionally, they extend to the development of new imaging techniques, real-time cognitive assessments, physiological monitoring, and personalized risk profiles tailored for astronauts. Furthermore, these technologies enable advancements in pharmacogenomics (PGx), as well as the identification of novel spaceflight biomarkers and the development of corresponding countermeasures. In this review, we highlight some of the recent biomedical research from the National Aeronautics and Space Administration (NASA), Japan Aerospace Exploration Agency (JAXA), European Space Agency (ESA), and other space agencies, and also detail the commercial spaceflight sector's (e.g. SpaceX, Blue Origin, Axiom, Sierra Space) entrance into aerospace medicine and space biology, the first aerospace medicine biobank, and the myriad upcoming missions that will utilize these tools to ensure a permanent human presence beyond LEO, venturing out to other planets and moons.

3.
J Cell Mol Med ; 27(22): 3423-3430, 2023 11.
Artigo em Inglês | MEDLINE | ID: mdl-37882471

RESUMO

Monocytes and neutrophils play key roles in the cytokine storm triggered by SARS-CoV-2 infection, which changes their conformation and function. These changes are detectable at the cellular and molecular level and may be different to what is observed in other respiratory infections. Here, we applied machine learning (ML) to develop and validate an algorithm to diagnose COVID-19 using blood parameters. In this retrospective single-center study, 49 hemogram parameters from 12,321 patients with clinical suspicion of COVID-19 and tested by RT-PCR (4239 positive and 8082 negative) were analysed. The dataset was randomly divided into training and validation sets. Blood cell parameters and patient age were used to construct the predictive model with the support vector machine (SVM) tool. The model constructed from the training set (5936 patients) achieved an accuracy for diagnosis of SARS-CoV-2 infection of 0.952 (95% CI: 0.875-0.892). Test sensitivity and specificity was 0.868 and 0.899, respectively, with a positive (PPV) and negative (NPV) predictive value of 0.896 and 0.872, respectively (prevalence 0.50). The validation set model (4964 patients) achieved an accuracy of 0.894 (95% CI: 0.883-0.903). Test sensitivity and specificity was 0.8922 and 0.8951, respectively, with a positive (PPV) and negative (NPV) predictive value of 0.817 and 0.94, respectively (prevalence 0.34). The area under the receiver operating characteristic curve was 0.952 for the algorithm performance. This algorithm may allow to rule out COVID-19 diagnosis with 94% of probability. This represents a great advance for early diagnostic orientation and guiding clinical decisions.


Assuntos
COVID-19 , Humanos , COVID-19/diagnóstico , Teste para COVID-19 , SARS-CoV-2 , Estudos Retrospectivos , Técnicas de Laboratório Clínico , Sensibilidade e Especificidade , Aprendizado de Máquina
4.
Mol Genet Genomics ; 298(2): 455-472, 2023 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-36604348

RESUMO

The PumAB type-II toxin-antitoxin (TA) system is encoded by pumAB genes that are organized into an operon. This system is encoded by the pUM505 plasmid, isolated from a Pseudomonas aeruginosa clinical strain. The pumA gene encodes a putative RelE toxin protein (toxic component), whereas the pumB gene encodes a putative HTH antitoxin protein. The expression of the PumAB system in Escherichia coli confers plasmid stability. In addition, PumA toxin overexpression in P. aeruginosa possesses the capability to increase bacterial virulence, an effect that is neutralized by the PumB antitoxin. The aim of this study was to establish the mechanism of regulation of the PumAB toxin-antitoxin system from pUM505. By an in silico analysis of the putative regulatory elements, we identified two putative internal promoters, PpumB and PpumB-AlgU (in addition to the already reported PpumAB), located upstream of pumB. By RT-qPCR assays, we determined that the pumAB genes are transcribed differentially, in that the mRNA of pumB is more abundant than the pumA transcript. We also observed that pumB could be expressed individually and that its mRNA levels decreased under oxidative stress, during individual expression as well as co-expression of pumAB. However, under stressful conditions, the pumA mRNA levels were not affected. This suggests the negative regulation of pumB by stressful conditions. The PumB purified protein was found to bind to a DNA region located between the PpumAB and the pumA coding region, and PumA participates in PumB binding, suggesting that a PumA-PumB complex co-regulates the transcription of the pumAB operon. Interestingly, the pumA mRNA levels decreased after incubation in vitro with PumB protein. This effect was repressed by ribonuclease inhibitors, suggesting that PumB could function as an RNAse toward the mRNA of the toxin. Taken together, we conclude that the PumAB TA system possesses multiple mechanisms to regulate its expression, as well as that the PumB antitoxin generates a decrease in the mRNA toxin levels, suggesting an RNase function. Our analysis provides new insights into the understanding of the control of TA systems from mobile plasmid-encoded genes from a human pathogen.


Assuntos
Antitoxinas , Toxinas Bacterianas , Sistemas Toxina-Antitoxina , Humanos , Antitoxinas/genética , Antitoxinas/metabolismo , Toxinas Bacterianas/genética , Sistemas Toxina-Antitoxina/genética , Proteínas Reguladoras de Apoptose/metabolismo , Escherichia coli/genética , Escherichia coli/metabolismo , Endorribonucleases/genética , Endorribonucleases/metabolismo , RNA Mensageiro , Ribonucleases/genética , Ribonucleases/metabolismo , Proteínas de Bactérias/genética , Proteínas de Bactérias/metabolismo , Regulação Bacteriana da Expressão Gênica
5.
Nature ; 546(7658): 406-410, 2017 06 15.
Artigo em Inglês | MEDLINE | ID: mdl-28538727

RESUMO

Transmission of Zika virus (ZIKV) in the Americas was first confirmed in May 2015 in northeast Brazil. Brazil has had the highest number of reported ZIKV cases worldwide (more than 200,000 by 24 December 2016) and the most cases associated with microcephaly and other birth defects (2,366 confirmed by 31 December 2016). Since the initial detection of ZIKV in Brazil, more than 45 countries in the Americas have reported local ZIKV transmission, with 24 of these reporting severe ZIKV-associated disease. However, the origin and epidemic history of ZIKV in Brazil and the Americas remain poorly understood, despite the value of this information for interpreting observed trends in reported microcephaly. Here we address this issue by generating 54 complete or partial ZIKV genomes, mostly from Brazil, and reporting data generated by a mobile genomics laboratory that travelled across northeast Brazil in 2016. One sequence represents the earliest confirmed ZIKV infection in Brazil. Analyses of viral genomes with ecological and epidemiological data yield an estimate that ZIKV was present in northeast Brazil by February 2014 and is likely to have disseminated from there, nationally and internationally, before the first detection of ZIKV in the Americas. Estimated dates for the international spread of ZIKV from Brazil indicate the duration of pre-detection cryptic transmission in recipient regions. The role of northeast Brazil in the establishment of ZIKV in the Americas is further supported by geographic analysis of ZIKV transmission potential and by estimates of the basic reproduction number of the virus.


Assuntos
Infecção por Zika virus/transmissão , Infecção por Zika virus/virologia , Zika virus/isolamento & purificação , América/epidemiologia , Número Básico de Reprodução , Brasil/epidemiologia , Variação Genética , Genoma Viral/genética , Humanos , Microcefalia/epidemiologia , Microcefalia/virologia , Epidemiologia Molecular , Filogeografia , Análise Espaço-Temporal , Zika virus/genética , Infecção por Zika virus/epidemiologia
6.
Can J Microbiol ; 69(5): 185-198, 2023 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-36753728

RESUMO

Dimorphic species of Mucor, which are cosmopolitan fungi belonging to subphylum Mucoromycotina, are metabolically versatile. Some species of Mucor are sources of biotechnological products, such as biodiesel from Mucor circinelloides and expression of heterologous proteins from Mucor lusitanicus. Furthermore, Mucor lusitanicus has been described as a model for understanding mucormycosis infections. However, little is known regarding the relationship between Mucor lusitanicus and other soil inhabitants. In this study, we investigated the potential use of Mucor lusitanicus as a biocontrol agent against fungal phytopathogens, namely Fusarium oxysporum f. sp. lycopersici, Fusarium solani, and Alternaria solani, which destroy economically important crops. Results showed that aerobic cell-free supernatants of the culture broth (SS) from Mucor lusitanicus inhibited the growth of the fungal phytopathogens in culture, soil, and tomato fruits. The SS obtained from a strain of Mucor lusitanicus carrying the deletion of rfs gene, which encodes an enzyme involved in the synthesis of siderophore rhizoferrin, had a decreased inhibitory effect against the growth of the phytopathogens. Contrarily, this inhibitory effect was more evident with the SS from an rfs-overexpressing strain compared to the wild-type. This study provides a framework for the potential biotechnological use of the molecules secreted from Mucor lusitanicus in the biocontrol of fungal phytopathogens.


Assuntos
Mucor , Mucormicose , Mucor/genética , Sideróforos , Mucormicose/microbiologia , Doenças das Plantas
7.
Cleft Palate Craniofac J ; 60(8): 917-927, 2023 08.
Artigo em Inglês | MEDLINE | ID: mdl-35382604

RESUMO

To assess the range and frequency of additional congenital malformations identified among children born alive with CL/P.Analysis of patient-level data from a national registry of cleft births linked to national administrative data of hospital admissions.National Health Service, England.Children born between 2000 and 2012 receiving cleft care in English NHS hospitals.The proportion of children with ICD-10 codes for additional congenital malformations, according to cleft type.The study included 9403 children. Of these 2114 (22.5%) had CL±A, 4509 (48.0%) had CP, 1896 (20.2%) had UCLP, and 884 (9.4%) had BCLP. A total of 3653 (38.8%) children had additional congenital malformations documented in their hospital admission records. The prevalence of additional congenital malformations was greatest among children with CP (53.0%), followed by those with BCLP (33.5%), UCLP (26.3%), and then CL±A (22.2%) (P < .001). Among those with UCLP, children with right-sided clefts were more likely to have additional malformations than those with left-sided clefts (31.6% vs 23.0%, P < .001). Malformations of the skeletal system and circulatory system were most common, affecting 10.5% and 10.2% of the included children, respectively. A total of 16.8% of children had additional congenital malformations affecting 2 or more structural systems.Congenital malformations are common among children born alive with a cleft, affecting over half of some cleft subgroups. Given the frequency of certain structural malformations, clinicians should consider standardized screening for these children. Establishing good links with pediatric and genetic services is recommended.


Assuntos
Fenda Labial , Fissura Palatina , Criança , Humanos , Fenda Labial/epidemiologia , Fenda Labial/genética , Medicina Estatal , Fissura Palatina/epidemiologia , Fissura Palatina/genética , Hospitalização
8.
Adv Exp Med Biol ; 1395: 69-73, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36527616

RESUMO

Supplementation of oxygen at concentrations significantly above environmental level for prolonged periods may lead to hyperoxia and tissue toxicity. The mammalian brain undergoes structural and functional changes during adaptation to hypoxia and hyperoxia. In this study we investigated the effect of prolonged hyperoxic exposure on cognitive and motor performance in mice. Two-month-old male mice were placed in either hyperoxic (50% O2) or normoxic conditions for 3 weeks. Cognitive function was measured using the Y-maze test. High alteration rate between the three arms of the maze is indicative of sustained memory and cognitive function. Motor function was measured using the grip strength and rotarod tests. In the rotarod test high speed and long latency are indicative of coordination and resistance. After 3 weeks of exposure, hematocrit levels were significantly decreased in the hyperoxia group compared to normoxic control littermates (%, mean ± SD, 37.8 ± 1.3, n = 15 vs. 49.9 ± 5.1, n = 15, p < 0.05). In the Y-maze test, chronic hyperoxic exposure resulted in a statistically significant decrease in alteration rate compared to normoxic control (%, mean ± SD, 53.4 ± 9.9, n = 30 vs. 61.2 ± 9.5, n = 15, p < 0.05). The rotarod and grip strength tests did not show statistically significant changes between the two groups. Our data suggest that chronic hyperoxia may lead to decreased cognitive performance in adult mice, which may be secondary to structural and functional changes in the brain.


Assuntos
Hiperóxia , Animais , Camundongos , Masculino , Hipóxia , Oxigênio , Adaptação Fisiológica , Cognição , Mamíferos
9.
Br J Surg ; 108(2): 160-167, 2021 03 12.
Artigo em Inglês | MEDLINE | ID: mdl-33711149

RESUMO

BACKGROUND: Studies reporting lower rates of surgery for older women with early invasive breast cancer have focused on women with oestrogen receptor (ER)-positive tumours. This study examined the factors that influence receipt of breast surgery in older women with ER-positive and ER-negative early invasive breast cancer . METHODS: Women aged 50 years or above with unilateral stage 1-3A early invasive breast cancer diagnosed in 2014-2017 were identified from linked English and Welsh cancer registration and routine hospital data sets. Logistic regression analysis was used to evaluate the influence of tumour and patient factors on receipt of surgery. RESULTS: Among 83 188 women, 86.8 per cent had ER-positive and 13.2 per cent had ER-negative early invasive breast cancer. These proportions were unaffected by age at diagnosis. Compared with women with ER-negative breast cancer, a higher proportion of women with ER-positive breast cancer presented with low risk tumour characteristics: G1 (20.0 versus 1.5 per cent), T1 (60.8 versus 44.2 per cent) and N0 (73.9 versus 68.8 per cent). The proportions of women with any recorded co-morbidity (13.7 versus 14.3 per cent) or degree of frailty (25 versus 25.8 per cent) were similar among women with ER-positive and ER-negative disease respectively. In women with ER-positive early invasive breast cancer aged 70-74, 75-79 and 80 years or above, the rate of no surgery was 5.6, 11.0 and 41.9 per cent respectively. Among women with ER-negative early invasive breast cancer, the corresponding rates were 3.8, 3.7 and 12.3 per cent. The relatively lower rate of surgery for ER-positive breast cancer persisted in women with good fitness. CONCLUSION: The reasons for the observer differences should be further explored to ensure consistency in treatment decisions.


Assuntos
Neoplasias da Mama/cirurgia , Tomada de Decisão Clínica , Mastectomia , Fatores Etários , Idoso , Idoso de 80 Anos ou mais , Neoplasias da Mama/diagnóstico , Neoplasias da Mama/patologia , Feminino , Humanos , Modelos Logísticos , Mastectomia/psicologia , Mastectomia/estatística & dados numéricos , Pessoa de Meia-Idade , Estadiamento de Neoplasias
10.
Antonie Van Leeuwenhoek ; 114(10): 1619-1632, 2021 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-34338933

RESUMO

Fusarium oxysporum f. sp. lycopersici is an important plant pathogen that has been used to understand the virulence mechanisms that soil inhabiting fungi exhibit during the infection process. In F. oxysporum many of the virulence factors are secreted, and the secretion process requires the formation of vesicles. Arf family members, represented by Arf (ADP- Ribosylation Factor), Arl (Arf-like), and Sar (Secretion-associated and Ras-related) proteins, are involved in the vesicle creation process. In this study we identified the Arf family members in F. oxysporum f. sp. lycopersici, which includes seven putative proteins: Arf1, Arf3, Arl1 through Arl3, Arl8B, and Sar1. Quantification of the mRNA levels of each arf encoding gene revealed that the highest expression corresponds to arf1 in all tested conditions. The phylogenetic analysis revealed that no other Arf1 paralogue, such as Arf2 from yeast, is present in F. oxysporum f. sp. lycopersici. The essential function suggested of Arf1 in F. oxysporum f. sp. lycopersici was corroborated experimentally when, after several attempts, it was impossible to obtain a knockout mutant in arf1. Moreover, arl3 mRNA levels increased significantly when plant tissue was added as a sole carbon source, suggesting that the product of these genes could play pivotal roles during plant infection, the corresponding mutant ∆arl3 was less virulent compared to the wild-type strain. These results describe the role of arl3 as a critical regulator of the virulence in F. oxysporum f. sp. lycopersici and stablish a framework for the arf family members to be studied in deeper details in this phytopathogen.


Assuntos
Fusarium , Solanum lycopersicum , Fusarium/genética , Filogenia , Doenças das Plantas , Virulência/genética
11.
Adv Exp Med Biol ; 1269: 271-276, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33966229

RESUMO

Hypoxia-inducible factors (HIFs) are transcriptional regulators that mediate in mice for HIF-1 and HIF-2. The objective of this study was to investigate the effect of neuronal deletion of HIF-1 and HIF-2 in hypoxic adaptation by using the neuron-specific knockout (KO) mice. The floxed control and KO mice were used. Hypoxic mice were kept in a hypobaric chamber at a pressure of 300 torr (0.4 ATM, which was equivalent to 8% oxygen under normobaric condition) for 3 weeks. The littermate, normoxic control mice were housed in the same room next to the chamber to match ambient conditions. Body weights were monitored throughout the 3-week course. Cognitive function was measured using a Y-maze test; motor functions were measured using the rotarod test and the grip strength test. The hematocrit increased significantly at the end of 3-week hypoxic exposure in both control and KO mice. In the Y-maze test, the alternation rate (indicative of sustained cognition) trended lower in the KO mice compared to the controls following hypoxia (%, 51.3 ± 13.1, n = 6 vs. 63.2 ± 12.0, n = 8). In the rotarod test, the latency (seconds) in the KO mice was significantly lower compared to the controls (50.4 ± 5.7 vs. 77.1 ± 5.0, n = 3 each before hypoxia and 66.4 ± 3.4, n = 6 vs. 98.1 ± 15.4 after hypoxia, n = 3). The grip strength in the KO mice was similar compared to the control mice before hypoxia, but the strength of KO mice trended higher after hypoxic exposure. Our data suggest that deficiency of neuronal HIF-1 and HIF-2 may result in changes in behavioral performance and other adaptative responses to hypoxia.


Assuntos
Hipóxia , Neurônios , Animais , Fatores de Transcrição Hélice-Alça-Hélice Básicos , Hipóxia/genética , Fator 1 Induzível por Hipóxia , Subunidade alfa do Fator 1 Induzível por Hipóxia/genética , Camundongos , Camundongos Knockout , Oxigênio
12.
Water Sci Technol ; 84(5): 1125-1135, 2021 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-34534110

RESUMO

The Water Network of the National Autonomous University of Mexico (Red del Agua UNAM) and the Program for the Management, Use, and Reuse of Water in UNAM (PUMAGUA) carried out a survey with the aim of knowing the water consumption practices of the university community in its campuses located in the Metropolitan Area of the Valley of Mexico. A sample of 2,095 students, academics, administrative and support staff participated in this survey. The results show that 74% of the sample consume bottled water and that their average spending is between 0.50 and 1 dollar per day (11 to 20 Mexican pesos). The rates of bottled water consumption contrasts with the perception about water quality, since only 13% consider water quality distributed in the water fountains located within university campuses as 'poor' or 'very poor'. The rates of bottled water consumption among university community are similar to the ones reported by studies in Mexico City and in Mexico as a whole, even though UNAM has a Water Observatory that allows people to know in real time water quantity and quality in university campuses.


Assuntos
Água Potável , Universidades , Ingestão de Líquidos , Humanos , México , Qualidade da Água , Abastecimento de Água
13.
Med Oral Patol Oral Cir Bucal ; 26(2): e195-e207, 2021 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-33037800

RESUMO

BACKGROUND: to systematically review the literature, comparing the healing of osteoradionecrosis (ORN) among the therapeutic alternatives: surgical, pharmacological and combined. MATERIAL AND METHODS: The review was organized according to the PRISMA protocol with regards to the following PICO question: patients with ORN of the jaws (P=Patient); all interventions reported (I = intervention); between all therapies (C=Comparison); healing of lesions (O=outcome). RESULTS: Surgical treatment was the most common choice (46.3%) followed by pharmacological treatment, exclusively (25.9%) or combined (26.9%). Treatment exclusively by surgical intervention seems to be most effective option, with 51.2% of the lesions healed, OR for healing of 5.7 (CI95% 1.9-16.9, p=0.002). Only 1 case (0.9%) corresponded to low level laser therapy. CONCLUSIONS: It seems clear that early intervention with conservative surgical combined with pharmacological methods improves the prognosis of ORN.


Assuntos
Neoplasias de Cabeça e Pescoço , Doenças Maxilomandibulares , Osteorradionecrose , Humanos , Arcada Osseodentária , Doenças Maxilomandibulares/etiologia , Osteorradionecrose/cirurgia , Prognóstico
14.
Infect Immun ; 88(2)2020 01 22.
Artigo em Inglês | MEDLINE | ID: mdl-31685547

RESUMO

The fungus Mucor circinelloides undergoes yeast-mold dimorphism, a developmental process associated with its capability as a human opportunistic pathogen. Dimorphism is strongly influenced by carbon metabolism, and hence the type of metabolism likely affects fungus virulence. We investigated the role of ethanol metabolism in M. circinelloides virulence. A mutant in the adh1 gene (M5 strain) exhibited higher virulence than the wild-type (R7B) and the complemented (M5/pEUKA-adh1+) strains, which were nonvirulent when tested in a mouse infection model. Cell-free culture supernatant (SS) from the M5 mutant showed increased toxic effect on nematodes compared to that from R7B and M5/pEUKA-adh1+ strains. The concentration of acetaldehyde excreted by strain M5 in the SS was higher than that from R7B, which correlated with the acute toxic effect on nematodes. Remarkably, strain M5 showed higher resistance to H2O2, resistance to phagocytosis, and invasiveness in mouse tissues and induced an enhanced systemic inflammatory response compared with R7B. The mice infected with strain M5 under disulfiram treatment exhibited only half the life expectancy of those infected with M5 alone, suggesting that acetaldehyde produced by M. circinelloides contributes to the toxic effect in mice. These results demonstrate that the failure in fermentative metabolism, in the step of the production of ethanol in M. circinelloides, contributes to its virulence, inducing a more severe tissue burden and inflammatory response in mice as a consequence of acetaldehyde overproduction.


Assuntos
Fermentação/fisiologia , Mucor/metabolismo , Mucor/patogenicidade , Virulência/fisiologia , Álcool Desidrogenase/metabolismo , Animais , Linhagem Celular , Fermentação/efeitos dos fármacos , Proteínas Fúngicas/metabolismo , Peróxido de Hidrogênio/farmacologia , Inflamação/metabolismo , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Mucor/efeitos dos fármacos , Fagocitose/efeitos dos fármacos , Fagocitose/fisiologia , Células RAW 264.7 , Virulência/efeitos dos fármacos
15.
Nanotechnology ; 31(50): 505715, 2020 Dec 11.
Artigo em Inglês | MEDLINE | ID: mdl-33025922

RESUMO

The design of optoelectronic devices made with ZnO superlattices requires the knowledge of the refractive index, which currently can be done only for films thicker than 30 nm. In this work, we present an effective medium approach to determine the refractive index of ZnO layers as thin as 2 nm. The approach was implemented by determining the refractive index of ZnO layers ranging from 2 nm to 20 nm using spectroscopic ellipsometry measurements in multilayers. For a precise control of morphology and thickness, the superlattices were fabricated with atomic layer deposition (ALD) with alternating layers of 2 nm thick Al2O3 and ZnO, labeled as N ZnO-Al2O3, where N = 10, 20, 30, 50, 75 and 100. The total thickness of all superlattices was kept at 100 nm. The approach was validated by applying it to similar superlattices reported in the literature and fitting the transmittance spectra of the superlattices.

16.
Fungal Genet Biol ; 129: 40-51, 2019 08.
Artigo em Inglês | MEDLINE | ID: mdl-31014992

RESUMO

Mucor circinelloides is an etiologic agent of mucormycosis, a fungal infection produced by Mucorales often associated with mortality due to unavailability of antifungal drugs. Arl proteins belong to the Arf family and are involved in vesicle trafficking and tubulin assembly. This study identified two Arl (Arf-like)-encoding genes, arl1 and arl2, in M. circinelloides and explored their function in morphogenesis, virulence, and antifungal susceptibility. Although Arl1 and Arl2 proteins shared 55% amino acid sequence identity, arl1 and arl2 genes showed distinct transcriptional expression patterns. arl1 was expressed at higher levels than arl2 and induced in mycelia, suggesting a role in morphological transitions. Disruption of the arl1 and arl2 genes led to heterokaryon (Δarl1(+)(-)) and homokaryon (Δarl2) genotypes, respectively. The incapacity to generate homokaryon mutants for arl1 suggested that it is essential for growth of M. circinelloides. Deletion of each gene reduced the expression of the other, suggesting the existence of a positive cross-regulation between them. Thus, deletion of arl2 resulted in a ~60% reduction of arl1 expression, whereas the Δarl1(+)(-) showed ∼90% reduction of arl1 expression. Mutation of arl2 showed no phenotype or a mild phenotype between Δarl1(+)(-) and wild-type (WT), suggesting that all observed phenotypes in both mutant strains corresponded to arl1 low expression. The Δarl1(+)(-) produced a small amount of spores that showed increased sensitivity to dodecyl-sulfate and azoles, suggesting a defect in the cell wall that was further supported by decrease in saccharide content. These defects in the cell wall were possibly originated by abnormal vesicle trafficking since FM4-64 staining of both mutants Δarl1(+)(-) and Δarl2 revealed less well-localized endosomes compared to the WT. Moreover, aberrant vesicle trafficking may be responsible for the secretion of specific virulence-related proteins since cell-free medium from Δarl1(+)(-) were found to increase killing of Caenorhabditis elegans compared to WT.


Assuntos
Antifúngicos/farmacologia , Proteínas Fúngicas/genética , Mucor/efeitos dos fármacos , Mucor/genética , Genótipo , Mucor/patogenicidade , Mutação , Filogenia , Transporte Proteico , Esporos Fúngicos/patogenicidade , Proteínas de Transporte Vesicular/genética , Virulência
17.
Microb Pathog ; 137: 103737, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31513895

RESUMO

Mucor circinelloides is an opportunistic human pathogen that is used to study mucormycosis, a rare but lethal infection in susceptible immunosuppressed patients. However, the virulence characteristics of this pathogen have not been fully elucidated. In this study, sporangiospores (spores) produced on YPG medium supplemented with native blood serum increased the virulence of M. circinelloides compared with spores produced on YPG supplemented with denatured blood serum or on YPG alone. The spores produced from YPG supplemented with native blood serum increased nematode death and led to significant increases in interleukin (IL)-6, IL-1ß, macrophage inhibitory protein-2, and tumour necrosis factor α mRNA levels in liver and lung tissues from infected diabetic mice compared with those in tissues from animals infected with spores produced in the presence of YPG supplemented with denatured blood serum or of YPG alone. Moreover, spores produced from cultures supplemented with native blood serum showed increased germination rates and longer hyphae compared with other spores. The spores produced in YPG supplemented with native blood serum also enhanced resistance to stress factors and H2O2 and increased thermotolerance compared with spores produced under other conditions. In addition, spores produced in presence of blood serum increased the ability of the pathogen to survive in the presence of macrophages. Taken together, our results showed that these factors were important features for fungal virulence in humans and suggested that thermolabile components in the blood serum may induce M. circinelloides virulence.


Assuntos
Mucor/patogenicidade , Mucormicose/sangue , Soro/microbiologia , Esporos Fúngicos/metabolismo , Animais , Citocinas/metabolismo , Diabetes Mellitus Experimental , Humanos , Peróxido de Hidrogênio , Hifas/crescimento & desenvolvimento , Interleucina-1beta/metabolismo , Interleucina-6/metabolismo , Pulmão , Macrófagos/microbiologia , Masculino , Camundongos , RNA Mensageiro/metabolismo , Esporos Fúngicos/crescimento & desenvolvimento , Virulência
18.
Phys Rev Lett ; 123(4): 042502, 2019 Jul 26.
Artigo em Inglês | MEDLINE | ID: mdl-31491269

RESUMO

We report the first measurement of the neutron cross section on argon in the energy range of 100-800 MeV. The measurement was obtained with a 4.3-h exposure of the Mini-CAPTAIN detector to the WNR/LANSCE beam at LANL. The total cross section is measured from the attenuation coefficient of the neutron flux as it traverses the liquid argon volume. A set of 2631 candidate interactions is divided in bins of the neutron kinetic energy calculated from time-of-flight measurements. These interactions are reconstructed with custom-made algorithms specifically designed for the data in a time projection chamber the size of the Mini-CAPTAIN detector. The energy averaged cross section is 0.91±0.10(stat)±0.09(syst) b. A comparison of the measured cross section is made to the GEANT4 and FLUKA event generator packages, where the energy averaged cross sections in this range are 0.60 and 0.68 b, respectively.

19.
BMC Cancer ; 19(1): 1241, 2019 Dec 21.
Artigo em Inglês | MEDLINE | ID: mdl-31864338

RESUMO

BACKGROUND: To investigate the incidence of non-cancer mortalities and prognostic factors associated with competitive causes of death in a homogeneous cohort of patients with locally advanced head and neck cancer treated with radiotherapy and systemic treatment. METHODS: This study included 284 patients with locally advanced head and neck cancer treated with radiotherapy and systemic treatment between 2005 and 2017. The cumulative incidence of death associated with tumour, second tumours, treatment, side effects and comorbidity was calculated. A Fine and Gray regression model was used to investigate factors associated with cancer and competitive mortality. RESULTS: The cumulative incidence of tumoral death at 5 and 10 years were 35 and 47% respectively, whereas the cumulative incidence of competitive mortality were 10 and 12% respectively. In the multivariate analysis, age and comorbidity were independent factors for non-cancer mortality. Patients with a high risk of non-cancer mortality presented a cumulative incidence of 17.3% at 5 years and 18.4% at 10 years. CONCLUSIONS: This study demonstrated a high incidence of competing mortality in older patients with comorbidities. Non-cancer deaths should be considered when selecting patients for combination therapies and in the study design ofclinical trials.


Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Causas de Morte , Recidiva Local de Neoplasia/mortalidade , Recidiva Local de Neoplasia/terapia , Adulto , Fatores Etários , Idoso , Idoso de 80 Anos ou mais , Quimiorradioterapia/mortalidade , Comorbidade , Feminino , Neoplasias de Cabeça e Pescoço/tratamento farmacológico , Neoplasias de Cabeça e Pescoço/epidemiologia , Neoplasias de Cabeça e Pescoço/radioterapia , Neoplasias de Cabeça e Pescoço/terapia , Humanos , Masculino , Pessoa de Meia-Idade , Recidiva Local de Neoplasia/tratamento farmacológico , Recidiva Local de Neoplasia/radioterapia , Estudos Retrospectivos , Espanha/epidemiologia , Taxa de Sobrevida
20.
Scand J Rheumatol ; 48(6): 454-459, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31210075

RESUMO

Objective: To evaluate the reliability and prevalence of enthesis ultrasound (US) elemental lesions in patients with psoriatic arthritis (PsA), using the Madrid Sonographic Enthesis Index (MASEI) and Outcome Measures in Rheumatology (OMERACT) definitions.Methods: The study included 27 PsA patients with metacarpophalangeal joint swelling. An US rheumatologist performed the MASEI examination. Prevalence and reliability of the included elemental lesions [structure, thickness, erosion, enthesophytes, power Doppler (PD), and bursae] were evaluated. In addition, three other PD definitions were checked: PD OMERACT (≤ 2 mm to the bone profile), PD enthesis-tendon (> 2 mm from the bone profile), and PD bursa. Short (3-5 s) videos of US examinations were recorded for reliability assessment.Results: MASEI and all PD definitions showed good to excellent reliability. The best reliability values were found in erosions, bursae, and PD. When present, the PD signal always appeared in more than one location of the evaluated areas. Enthesis Doppler was present in 81.5% of patients. Abnormal tendon structure and enthesophytes were the most prevalent lesions.Conclusion: MASEI demonstrates to be a reliable tool in PsA. All enthesis US Doppler definitions demonstrate to be reliable for its use in PsA with minimal differences, being PD MASEI the most sensitive in active patients.


Assuntos
Artrite Psoriásica/diagnóstico por imagem , Entesopatia/diagnóstico por imagem , Ultrassonografia Doppler/métodos , Adulto , Artrite Psoriásica/patologia , Entesopatia/patologia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Reprodutibilidade dos Testes
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA