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1.
J Cardiothorac Vasc Anesth ; 38(3): 649-659, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38228424

RESUMO

OBJECTIVE: To verify the impact of preoperative levosimendan on patients with severe left ventricular dysfunction (ejection fraction <35%) undergoing isolated coronary artery bypass grafting. DESIGN: A meta-analysis. SETTING: Hospitals. PARTICIPANTS: The authors included 1,225 patients from 6 randomized controlled trials. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: The authors performed a meta-analysis of trials that compared preoperative levosimendan with placebo or no therapy, reporting efficacy and safety endpoints. Statistical analyses used mean differences and risk ratios (RR), with a random effects model. Six studies were included, comprising 1,225 patients, of whom 615 (50.2%) received preoperative levosimendan, and 610 (49.8%) received placebo/no therapy. Preoperative levosimendan showed a lower risk of all-cause mortality (RR 0.31; 95% CI 0.16-0.60; p < 0.01; I2 = 0%), postoperative acute kidney injury (RR 0.44; 95% CI 0.25-0.77; p < 0.01; I2 = 0%), low-cardiac-output syndrome (RR 0.45; 95% CI 0.30-0.66; p < 0.001; I2 = 0%), and postoperative atrial fibrillation (RR 0.49; 95% CI 0.25-0.98; p = 0.04; I2 = 85%) compared to control. Moreover, levosimendan significantly reduced the need for postoperative inotropes and increased the cardiac index at 24 hours postoperatively. There were no differences between groups for perioperative myocardial infarction, hypotension, or any adverse events. CONCLUSION: Preoperative levosimendan in patients with severe left ventricular dysfunction undergoing isolated coronary artery bypass grafting was associated with reduced all-cause mortality, low-cardiac-output syndrome, acute kidney injury, postoperative atrial fibrillation, and the need for circulatory support without compromising safety.


Assuntos
Injúria Renal Aguda , Fibrilação Atrial , Simendana , Disfunção Ventricular Esquerda , Humanos , Injúria Renal Aguda/etiologia , Fibrilação Atrial/etiologia , Baixo Débito Cardíaco/tratamento farmacológico , Baixo Débito Cardíaco/etiologia , Cardiotônicos/uso terapêutico , Ponte de Artéria Coronária/efeitos adversos , Complicações Pós-Operatórias/epidemiologia , Complicações Pós-Operatórias/prevenção & controle , Complicações Pós-Operatórias/tratamento farmacológico , Ensaios Clínicos Controlados Aleatórios como Assunto , Simendana/uso terapêutico
2.
PLoS Pathog ; 17(6): e1009703, 2021 06.
Artigo em Inglês | MEDLINE | ID: mdl-34181702

RESUMO

Prion diseases are transmissible neurodegenerative disorders that affect mammals, including humans. The central molecular event is the conversion of cellular prion glycoprotein, PrPC, into a plethora of assemblies, PrPSc, associated with disease. Distinct phenotypes of disease led to the concept of prion strains, which are associated with distinct PrPSc structures. However, the degree to which intra- and inter-strain PrPSc heterogeneity contributes to disease pathogenesis remains unclear. Addressing this question requires the precise isolation and characterization of all PrPSc subpopulations from the prion-infected brains. Until now, this has been challenging. We used asymmetric-flow field-flow fractionation (AF4) to isolate all PrPSc subpopulations from brains of hamsters infected with three prion strains: Hyper (HY) and 263K, which produce almost identical phenotypes, and Drowsy (DY), a strain with a distinct presentation. In-line dynamic and multi-angle light scattering (DLS/MALS) data provided accurate measurements of particle sizes and estimation of the shape and number of PrPSc particles. We found that each strain had a continuum of PrPSc assemblies, with strong correlation between PrPSc quaternary structure and phenotype. HY and 263K were enriched with large, protease-resistant PrPSc aggregates, whereas DY consisted primarily of smaller, more protease-sensitive aggregates. For all strains, a transition from protease-sensitive to protease-resistant PrPSc took place at a hydrodynamic radius (Rh) of 15 nm and was accompanied by a change in glycosylation and seeding activity. Our results show that the combination of AF4 with in-line MALS/DLS is a powerful tool for analyzing PrPSc subpopulations and demonstrate that while PrPSc quaternary structure is a major contributor to PrPSc structural heterogeneity, a fundamental change, likely in secondary/tertiary structure, prevents PrPSc particles from maintaining proteinase K resistance below an Rh of 15 nm, regardless of strain. This results in two biochemically distinctive subpopulations, the proportion, seeding activity, and stability of which correlate with prion strain phenotype.


Assuntos
Difusão Dinâmica da Luz/métodos , Fotometria/métodos , Proteínas PrPSc/análise , Proteínas PrPSc/química , Animais , Cricetinae , Hidrodinâmica , Camundongos , Estrutura Quaternária de Proteína
3.
PLoS Pathog ; 17(7): e1009795, 2021 07.
Artigo em Inglês | MEDLINE | ID: mdl-34310662

RESUMO

Chronic wasting disease (CWD) is a prion disease affecting cervids. Polymorphisms in the prion protein gene can result in extended survival of CWD-infected animals. However, the impact of polymorphisms on cellular prion protein (PrPC) and prion properties is less understood. Previously, we characterized the effects of a polymorphism at codon 116 (A>G) of the white-tailed deer (WTD) prion protein and determined that it destabilizes PrPC structure. Comparing CWD isolates from WTD expressing homozygous wild-type (116AA) or heterozygous (116AG) PrP, we found that 116AG-prions were conformationally less stable, more sensitive to proteases, with lower seeding activity in cell-free conversion and reduced infectivity. Here, we aimed to understand CWD strain emergence and adaptation. We show that the WTD-116AG isolate contains two different prion strains, distinguished by their host range, biochemical properties, and pathogenesis from WTD-116AA prions (Wisc-1). Serial passages of WTD-116AG prions in tg(CerPrP)1536+/+ mice overexpressing wild-type deer-PrPC revealed two populations of mice with short and long incubation periods, respectively, and remarkably prolonged clinical phase upon inoculation with WTD-116AG prions. Inoculation of serially diluted brain homogenates confirmed the presence of two strains in the 116AG isolate with distinct pathology in the brain. Interestingly, deglycosylation revealed proteinase K-resistant fragments with different electrophoretic mobility in both tg(CerPrP)1536+/+ mice and Syrian golden hamsters infected with WTD-116AG. Infection of tg60 mice expressing deer S96-PrP with 116AG, but not Wisc-1 prions induced clinical disease. On the contrary, bank voles resisted 116AG prions, but not Wisc-1 infection. Our data indicate that two strains co-existed in the WTD-116AG isolate, expanding the variety of CWD prion strains. We argue that the 116AG isolate does not contain Wisc-1 prions, indicating that the presence of 116G-PrPC diverted 116A-PrPC from adopting a Wisc-1 structure. This can have important implications for their possible distinct capacities to cross species barriers into both cervids and non-cervids.


Assuntos
Proteínas Priônicas/genética , Doença de Emaciação Crônica/genética , Animais , Arvicolinae , Cricetinae , Cervos , Mesocricetus , Camundongos , Polimorfismo de Nucleotídeo Único , Doença de Emaciação Crônica/transmissão
4.
Cell Tissue Res ; 392(1): 135-148, 2023 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-36201049

RESUMO

Chronic wasting disease (CWD) strains present a novel challenge to defining and mitigating this contagious prion disease of deer, elk, moose, and reindeer. Similar to strains of other prion diseases (bovine spongiform encephalopathy, sheep scrapie), CWD strains can affect biochemical and neuropathological properties of the infectious agent, and importantly interspecies transmission. To date, ten CWD strains have been characterized. The expanding range of CWD in North America and its presence in South Korea as well as Scandinavian countries will potentially result in millions of cervids infected with CWD; thus, novel strains will continue to emerge. In this review, we will summarize the characteristics of known CWD strains and describe the impact of prion protein gene polymorphisms on the generation of strains. We will also discuss the evidence that individual cervids can harbor more than one CWD strain, complicating strain analysis, and affecting selection and adaptation of strains in new hosts.


Assuntos
Cervos , Príons , Doença de Emaciação Crônica , Bovinos , Animais , Ovinos , Doença de Emaciação Crônica/genética , Doença de Emaciação Crônica/metabolismo , Cervos/metabolismo , Proteínas Priônicas/metabolismo , Príons/genética
5.
J Biol Chem ; 295(15): 4985-5001, 2020 04 10.
Artigo em Inglês | MEDLINE | ID: mdl-32111742

RESUMO

Chronic wasting disease (CWD) is caused by an unknown spectrum of prions and has become enzootic in populations of cervid species that express cellular prion protein (PrPC) molecules varying in amino acid composition. These PrPC polymorphisms can affect prion transmission, disease progression, neuropathology, and emergence of new prion strains, but the mechanistic steps in prion evolution are not understood. Here, using conformation-dependent immunoassay, conformation stability assay, and protein-misfolding cyclic amplification, we monitored the conformational and phenotypic characteristics of CWD prions passaged through deer and transgenic mice expressing different cervid PrPC polymorphisms. We observed that transmission through hosts with distinct PrPC sequences diversifies the PrPCWD conformations and causes a shift toward oligomers with defined structural organization, replication rate, and host range. When passaged in host environments that restrict prion replication, distinct co-existing PrPCWD conformers underwent competitive selection, stabilizing a new prion strain. Nonadaptive conformers exhibited unstable replication and accumulated only to low levels. These results suggest a continuously evolving diversity of CWD conformers and imply a critical interplay between CWD prion plasticity and PrPC polymorphisms during prion strain evolution.


Assuntos
Encéfalo/patologia , Adaptação ao Hospedeiro , Polimorfismo Genético , Proteínas PrPC/genética , Doença de Emaciação Crônica/genética , Animais , Encéfalo/metabolismo , Cervos , Camundongos , Camundongos Transgênicos , Doença de Emaciação Crônica/patologia
6.
Vet Res ; 52(1): 115, 2021 Sep 06.
Artigo em Inglês | MEDLINE | ID: mdl-34488900

RESUMO

The spread of chronic wasting disease (CWD) during the last six decades has resulted in cervid populations of North America where CWD has become enzootic. This insidious disease has also been reported in wild and captive cervids from other continents, threatening ecosystems, livestock and public health. These CWD "hot zones" are particularly complex given the interplay between cervid PRNP genetics, the infection biology, the strain diversity of infectious prions and the long-term environmental persistence of infectivity, which hinder eradication efforts. Here, we review different aspects of CWD including transmission mechanisms, pathogenesis, epidemiology and assessment of interspecies infection. Further understanding of these aspects could help identify "control points" that could help reduce exposure for humans and livestock and decrease CWD spread between cervids.


Assuntos
Cervos , Príons/efeitos adversos , Doença de Emaciação Crônica , Animais , Canadá/epidemiologia , Estados Unidos/epidemiologia , Doença de Emaciação Crônica/epidemiologia , Doença de Emaciação Crônica/etiologia , Doença de Emaciação Crônica/transmissão
7.
Sensors (Basel) ; 21(16)2021 Aug 13.
Artigo em Inglês | MEDLINE | ID: mdl-34450916

RESUMO

Coffee Leaf Rust (CLR) is a fungal epidemic disease that has been affecting coffee trees around the world since the 1980s. The early diagnosis of CLR would contribute strategically to minimize the impact on the crops and, therefore, protect the farmers' profitability. In this research, a cyber-physical data-collection system was developed, by integrating Remote Sensing and Wireless Sensor Networks, to gather data, during the development of the CLR, on a test bench coffee-crop. The system is capable of automatically collecting, structuring, and locally and remotely storing reliable multi-type data from different field sensors, Red-Green-Blue (RGB) and multi-spectral cameras (RE and RGN). In addition, a data-visualization dashboard was implemented to monitor the data-collection routines in real-time. The operation of the data collection system allowed to create a three-month size dataset that can be used to train CLR diagnosis machine learning models. This result validates that the designed system can collect, store, and transfer reliable data of a test bench coffee-crop towards CLR diagnosis.


Assuntos
Basidiomycota , Café , Coleta de Dados , Doenças das Plantas , Tecnologia de Sensoriamento Remoto
8.
Anal Chem ; 92(1): 1276-1284, 2020 01 07.
Artigo em Inglês | MEDLINE | ID: mdl-31815434

RESUMO

Chronic wasting disease (CWD) is the only prion disease naturally transmitted among farmed and free-ranging cervids (deer, elk, moose, etc.). These diseases are always fatal and have long asymptomatic incubation periods. By 2019, CWD-infected cervids had been detected in 26 states, three Canadian provinces, South Korea, Norway, Finland, and Sweden. Prions (PrPSc) replicate by inducing a normal cellular prion protein (PrPC) to adopt the prion conformation. This prion templated conformational conversion is influenced by PrPC polymorphisms. Cervid PrPC contains at least 20 different polymorphic sites. By using chymotrypsin, trypsin, or trypsin followed by chymotrypsin to digest denatured cervid PrP, 19 peptides suitable for multiple reaction monitoring (MRM)-based analysis and spanning positions 30-51, 61-112, and 114-231 of cervid PrP were identified. Ten of these peptides span polymorphism-containing regions of cervid PrP. The other nine contain no polymorphisms, so they can be used as internal standards. Calibration curves relating the area ratios of MRM signals from polymorphism-containing peptides to appropriate internal standard peptides were linear and had excellent correlation coefficients. Samples from heterozygous (G96/S96) white-tailed deer orally dosed with CWD from homozygous (G96/G96) deer were analyzed. The G96 polymorphism comprised 75 ± 5% of the total PrP from the G96/S96 heterozygotes. Heterozygous animals facilitate conversion of different PrPC polymorphisms into PrPSc. This approach can be used to quantitate the relative amounts of the polymorphisms present in other animal species and even humans.


Assuntos
Polimorfismo Genético/genética , Proteínas Priônicas/genética , Doença de Emaciação Crônica/genética , Animais , Animais Selvagens , Cervos , Espectrometria de Massas , Camundongos , Camundongos Transgênicos
9.
J Vasc Surg ; 71(6): 2004-2011, 2020 06.
Artigo em Inglês | MEDLINE | ID: mdl-31708305

RESUMO

OBJECTIVE: The Kommerell diverticulum (KD) is an extremely rare developmental abnormality of the aorta related to an aberrant subclavian artery (ASCA). The objective of our study was to review the natural history of KD and ASCA using our single-center experience in diagnosing and managing KD and ASCA. METHODS: A retrospective review of the Yale radiological database from January 1999 to December 2016 was performed. Only patients with KD/ASCA and a computed tomography (CT) scan of the chest were selected for review. The primary goal was to examine the natural history of KD and ASCA and the secondary goals were to review the management and outcomes of those patients treated for KD and ASCA. RESULTS: There were 75 patients with KD/ASCA identified, with a mean age of 63 ± 19 years; 49 were female (65%). On CT scans, left- and right-sided aortas were present in 47 (63%) and 28 (37%) patients. A right ASCA or a left ASCA were present in 47 (63%) and 28 (37%) patients. Six patients were symptomatic on presentation. Symptoms included dysphagia, chest or back pain, and emboli to the fingers. The mean KD diameter was 21.8 ± 6.0 mm and the distance to the opposite aortic wall (DAW) was 48.3 ± 10.8 mm. Sixty-six patients were followed for a mean of 31.7 ± 32.5 months. One patient ruptured without repair. Nine patients underwent operative intervention, including eight open and one endovascular repair. Complications from operative intervention included ischemic stroke with hemorrhagic transformation, deep vein thrombosis and pneumonia. The mean growth rate for KD and DAW was 1.45 ± 0.39 mm/year and 2.29 ± 0.47 mm/year, respectively. On multivariable regression analysis, hypertension was a predictor of growth of DAW (P = .03). CONCLUSIONS: KD is uncommon and shows a female predominance. The diverticulum grows, albeit slowly (KD and DAW growth rates of 1.45 ± 0.39 mm/year and 2.29 ± 0.47 mm/year). Most patients are asymptomatic, but dysphagia, chest/back pain, and distal emboli may occur. Rupture is rare. Symptomatic patients should be operated. Asymptomatic patients can be followed with serial CT scans.


Assuntos
Aorta/cirurgia , Anormalidades Cardiovasculares/cirurgia , Divertículo/cirurgia , Artéria Subclávia/anormalidades , Malformações Vasculares/cirurgia , Procedimentos Cirúrgicos Vasculares , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Aorta/anormalidades , Aorta/diagnóstico por imagem , Ruptura Aórtica/etiologia , Aortografia , Anormalidades Cardiovasculares/complicações , Anormalidades Cardiovasculares/diagnóstico por imagem , Angiografia por Tomografia Computadorizada , Connecticut , Bases de Dados Factuais , Progressão da Doença , Divertículo/congênito , Divertículo/diagnóstico por imagem , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Complicações Pós-Operatórias/etiologia , Estudos Retrospectivos , Fatores de Risco , Fatores Sexuais , Artéria Subclávia/diagnóstico por imagem , Artéria Subclávia/cirurgia , Centros de Atenção Terciária , Resultado do Tratamento , Malformações Vasculares/complicações , Malformações Vasculares/diagnóstico por imagem , Procedimentos Cirúrgicos Vasculares/efeitos adversos , Adulto Jovem
10.
PLoS Pathog ; 13(8): e1006553, 2017 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-28800624

RESUMO

Prion diseases are infectious neurodegenerative disorders of humans and animals caused by misfolded forms of the cellular prion protein PrPC. Prions cause disease by converting PrPC into aggregation-prone PrPSc. Chronic wasting disease (CWD) is the most contagious prion disease with substantial lateral transmission, affecting free-ranging and farmed cervids. Although the PrP primary structure is highly conserved among cervids, the disease phenotype can be modulated by species-specific polymorphisms in the prion protein gene. How the resulting amino-acid substitutions impact PrPC and PrPSc structure and propagation is poorly understood. We investigated the effects of the cervid 116A>G substitution, located in the most conserved PrP domain, on PrPC structure and conversion and on 116AG-prion conformation and infectivity. Molecular dynamics simulations revealed structural de-stabilization of 116G-PrP, which enhanced its in vitro conversion efficiency when used as recombinant PrP substrate in real-time quaking-induced conversion (RT-QuIC). We demonstrate that 116AG-prions are conformationally less stable, show lower activity as a seed in RT-QuIC and exhibit reduced infectivity in vitro and in vivo. Infectivity of 116AG-prions was significantly enhanced upon secondary passage in mice, yet conformational features were retained. These findings indicate that structurally de-stabilized PrPC is readily convertible by cervid prions of different genetic background and results in a prion conformation adaptable to cervid wild-type PrP. Conformation is an important criterion when assessing transmission barrier, and conformational variants can target a different host range. Therefore, a thorough analysis of CWD isolates and re-assessment of species-barriers is important in order to fully exclude a zoonotic potential of CWD.


Assuntos
Polimorfismo de Nucleotídeo Único , Proteínas Priônicas/genética , Doença de Emaciação Crônica/genética , Animais , Western Blotting , Cervos , Modelos Animais de Doenças , Interações Hidrofóbicas e Hidrofílicas , Camundongos , Modelos Moleculares , Simulação de Dinâmica Molecular , Reação em Cadeia da Polimerase , Conformação Proteica
11.
BMC Vet Res ; 15(1): 50, 2019 Feb 04.
Artigo em Inglês | MEDLINE | ID: mdl-30717795

RESUMO

BACKGROUND: Chronic wasting disease (CWD) is a prion disease affecting members of the Cervidae family. PrPC primary structures play a key role in CWD susceptibility resulting in extended incubation periods and regulating the propagation of CWD strains. We analyzed the distribution of abnormal prion protein (PrPCWD) aggregates in brain and peripheral organs from orally inoculated white-tailed deer expressing four different PRNP genotypes: Q95G96/Q95G96 (wt/wt), S96/wt, H95/wt and H95/S96 to determine if there are substantial differences in the deposition pattern of PrPCWD between different PRNP genotypes. RESULTS: Although we detected differences in certain brain areas, globally, the different genotypes showed similar PrPCWD deposition patterns in the brain. However, we found that clinically affected deer expressing H95 PrPC, despite having the longest survival periods, presented less PrPCWD immunoreactivity in particular peripheral organs. In addition, no PrPCWD was detected in skeletal muscle of any of the deer. CONCLUSIONS: Our data suggest that expression of H95-PrPC limits peripheral accumulation of PrPCWD as detected by immunohistochemistry. Conversely, infected S96/wt and wt/wt deer presented with similar PrPCWD peripheral distribution at terminal stage of disease, suggesting that the S96-PrPC allele, although delaying CWD progression, does not completely limit the peripheral accumulation of the infectious agent.


Assuntos
Encéfalo/patologia , Cervos , Proteínas Priônicas/genética , Doença de Emaciação Crônica/patologia , Animais , Cerebelo/patologia , Suscetibilidade a Doenças , Lobo Frontal/patologia , Genótipo , Intestinos/patologia , Rim/patologia , Tecido Linfoide/patologia , Músculo Esquelético/patologia , Pâncreas/patologia , Polimorfismo Genético/genética , Doenças Priônicas/patologia , Doenças Priônicas/veterinária , Glândulas Salivares/patologia
12.
Catheter Cardiovasc Interv ; 91(7): 1331-1338, 2018 06.
Artigo em Inglês | MEDLINE | ID: mdl-29405592

RESUMO

OBJECTIVE: Treatment for lifestyle limiting claudication (LLC) that is due to infra-inguinal peripheral artery disease relies on either bypass, angioplasty, and/or stenting. Given the enthusiasm and shift toward more endovascular therapy for treatment of LLC, we sought to analyze whether octogenarians benefit from infra-inguinal interventions in the same manner as their younger counterparts. METHODS: We identified all patients admitted for elective treatment of LLC from the Nationwide Inpatient Sample from 2003 to 2012, who received open surgical or endovascular intervention for infra-inguinal peripheral arterial disease. These patients were divided into two groups including those between the ages 60-80 years (younger cohort) and those older than 80 years (octogenarians). Primary end-points included morbidity and mortality and the secondary end-points were length of hospital stay (LOS) and disposition after dismissal. RESULTS: Among 59,323 discharges identified in the dataset, 34,658 (58%) were males. There were 50,323 (85%) patients in the younger cohort and 9,000 (15%) octogenarians. The mean age was 69.9 ± 5.7 years and 84.2 ± 3.0 years for the younger cohort and octogenarians, respectively. The mean Charlson comorbidity index (CCI) was higher in our younger cohort (2.1 ± 1.1, P < 0.001). Octogenarians mainly treated with open surgery prior to 2004 are now treated endovascularly and this trend has remained stable. The younger cohort's treatment modality has fluctuated through the study period and most recently is treated mainly with open surgery. The rate of acute kidney injury, exacerbation of congestive heart failure and mortality was higher in octogenarians (P < 0.001). The rate of infectious wound complications was higher in the younger cohort (P < 0.05). Octogenarians have longer LOS and are dismissed in higher percentage to a skilled nursing facility (P < 0.001). On binary logistic regression analysis, age over 80 years, female sex, higher CCI and having an open as opposed to an endovascular procedure are independent predictors of in-hospital mortality. CONCLUSIONS: Although endovascular techniques seem to dominate the care for octogenarians with LLC, the overall morbidity and mortality rates are significantly higher in this patient population. Other options such as medical management and/or supervised exercise therapy should be explored in this patient group.


Assuntos
Procedimentos Endovasculares/mortalidade , Claudicação Intermitente/mortalidade , Claudicação Intermitente/cirurgia , Doença Arterial Periférica/cirurgia , Procedimentos Cirúrgicos Vasculares/mortalidade , Fatores Etários , Idoso , Idoso de 80 Anos ou mais , Comorbidade , Bases de Dados Factuais , Procedimentos Endovasculares/efeitos adversos , Feminino , Nível de Saúde , Humanos , Claudicação Intermitente/diagnóstico , Claudicação Intermitente/fisiopatologia , Tempo de Internação , Masculino , Pessoa de Meia-Idade , Doença Arterial Periférica/diagnóstico , Doença Arterial Periférica/mortalidade , Doença Arterial Periférica/fisiopatologia , Estudos Retrospectivos , Fatores de Risco , Fatores de Tempo , Resultado do Tratamento , Estados Unidos , Procedimentos Cirúrgicos Vasculares/efeitos adversos
13.
Emerg Infect Dis ; 23(9): 1598-1600, 2017 09.
Artigo em Inglês | MEDLINE | ID: mdl-28820384

RESUMO

Human and mouse prion proteins share a structural motif that regulates resistance to common chronic wasting disease (CWD) prion strains. Successful transmission of an emergent strain of CWD prion, H95+, into mice resulted in infection. Thus, emergent CWD prion strains may have higher zoonotic potential than common strains.


Assuntos
Especificidade de Hospedeiro , Príons/química , Doença de Emaciação Crônica/transmissão , Animais , Cricetinae , Cervos , Humanos , Camundongos , Príons/metabolismo , Conformação Proteica em alfa-Hélice , Conformação Proteica em Folha beta , Estabilidade Proteica , Especificidade da Espécie , Doença de Emaciação Crônica/patologia
14.
J Virol ; 89(24): 12362-73, 2015 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-26423950

RESUMO

UNLABELLED: Transmission of chronic wasting disease (CWD) between cervids is influenced by the primary structure of the host cellular prion protein (PrP(C)). In white-tailed deer, PRNP alleles encode the polymorphisms Q95 G96 (wild type [wt]), Q95 S96 (referred to as the S96 allele), and H95 G96 (referred to as the H95 allele), which differentially impact CWD progression. We hypothesize that the transmission of CWD prions between deer expressing different allotypes of PrP(C) modifies the contagious agent affecting disease spread. To evaluate the transmission properties of CWD prions derived experimentally from deer of four PRNP genotypes (wt/wt, S96/wt, H95/wt, or H95/S96), transgenic (tg) mice expressing the wt allele (tg33) or S96 allele (tg60) were challenged with these prion agents. Passage of deer CWD prions into tg33 mice resulted in 100% attack rates, with the CWD H95/S96 prions having significantly longer incubation periods. The disease signs and neuropathological and protease-resistant prion protein (PrP-res) profiles in infected tg33 mice were similar between groups, indicating that a prion strain (Wisc-1) common to all CWD inocula was amplified. In contrast, tg60 mice developed prion disease only when inoculated with the H95/wt and H95/S96 CWD allotypes. Serial passage in tg60 mice resulted in adaptation of a novel CWD strain (H95(+)) with distinct biological properties. Transmission of first-passage tg60CWD-H95(+) isolates into tg33 mice, however, elicited two prion disease presentations consistent with a mixture of strains associated with different PrP-res glycotypes. Our data indicate that H95-PRNP heterozygous deer accumulated two CWD strains whose emergence was dictated by the PrP(C) primary structure of the recipient host. These findings suggest that CWD transmission between cervids expressing distinct PrP(C) molecules results in the generation of novel CWD strains. IMPORTANCE: CWD prions are contagious among wild and captive cervids in North America and in South Korea. We present data linking the amino acid variant Q95H in white-tailed deer cellular prion protein (PrP(C)) to the emergence of a novel CWD strain (H95(+)). We show that, upon infection, deer expressing H95-PrP(C) molecules accumulated a mixture of CWD strains that selectively propagated depending on the PRNP genotype of the host in which they were passaged. Our study also demonstrates that mice expressing the deer S96-PRNP allele, previously shown to be resistant to various cervid prions, are susceptible to H95(+) CWD prions. The potential for the generation of novel strains raises the possibility of an expanded host range for CWD.


Assuntos
Genótipo , Proteínas PrPC/genética , Proteínas PrPC/metabolismo , Doença de Emaciação Crônica/genética , Doença de Emaciação Crônica/metabolismo , Animais , Cervos , Camundongos , Camundongos Transgênicos
15.
PLoS Pathog ; 9(11): e1003755, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-24244171

RESUMO

Prion diseases are driven by the strain-specific, template-dependent transconformation of the normal cellular prion protein (PrP(C)) into a disease specific isoform PrP(Sc). Cell culture models of prion infection generally use replicating cells resulting in lower levels of prion accumulation compared to animals. Using non-replicating cells allows the accumulation of higher levels of PrP(Sc) and, thus, greater amounts of infectivity. Here, we infect non-proliferating muscle fiber myotube cultures prepared from differentiated myoblasts. We demonstrate that prion-infected myotubes generate substantial amounts of PrP(Sc) and that the level of infectivity produced in these post-mitotic cells, 10(5.5) L.D.50/mg of total protein, approaches that observed in vivo. Exposure of the myotubes to different mouse-adapted agents demonstrates strain-specific replication of infectious agents. Mouse-derived myotubes could not be infected with hamster prions suggesting that the species barrier effect is intact. We suggest that non-proliferating myotubes will be a valuable model system for generating infectious prions and for screening compounds for anti-prion activity.


Assuntos
Proliferação de Células , Proteínas PrPSc/metabolismo , Animais , Linhagem Celular , Cricetinae , Camundongos , Fibras Musculares Esqueléticas , Especificidade da Espécie
16.
Nanoscale Adv ; 6(17): 4426-4433, 2024 Aug 20.
Artigo em Inglês | MEDLINE | ID: mdl-39170979

RESUMO

The development of highly active, low-cost, and robust electrocatalysts for the oxygen evolution reaction (OER) is a crucial endeavor for the clean and economically viable production of hydrogen via electrochemical water splitting. Herein, cuprous oxide (Cu2O) thin films are deposited on silver nanowire (AgNW) networks by atmospheric-pressure spatial atomic layer deposition (AP-SALD). AgNW@Cu2O nanocomposites supported on conductive copper electrodes exhibited superior OER activity as compared to bare copper substrate and bare AgNWs. Moreover, a relationship between Cu2O thickness and OER activity was established. Notably, the most effective catalyst (AgNW@50nm-thick Cu2O) demonstrated very high OER activity with a low overpotential of 409 mV to deliver a current density of 10 mA cm-2 (η 10), a Tafel slope of 47 mV dec-1, a turnover frequency (TOF) of 4.2 s-1 at 350 mV, and good durability in alkaline media (1 M KOH). This highlights the potential of AgNWs as a powerful platform for the formation of highly efficient copper oxide catalysts towards OER. This work provides a foundation for the development of nanostructured Cu-based electrocatalysts for future clean energy conversion and storage systems.

17.
ACS Appl Mater Interfaces ; 16(8): 10439-10449, 2024 Feb 28.
Artigo em Inglês | MEDLINE | ID: mdl-38380672

RESUMO

The development of electrochromic systems, known for the modulation of their optical properties under an applied voltage, depends on the replacement of the state-of-the-art ITO (In2O3:Sn) transparent electrode (TE) as well as the improvement of electrochromic films. This study presents an innovative ITO-free electrochromic film architecture utilizing oxide-coated silver nanowire (AgNW) networks as a TE and V2O5 as an electrochromic oxide layer. The TE was prepared by simple spray deposition of AgNWs that allowed for tuning different densities of the network and hence the resistance and transparency of the film. The conformal oxide coating (SnO2 or ZnO) on AgNWs was deposited by atmospheric-pressure spatial atomic layer deposition, an open-air fast and scalable process yielding a highly stable electrode. V2O5 thin films were then deposited by radio frequency magnetron sputtering on the AgNW-based TE. Independent of the oxide's nature, a 20 nm protective layer thickness was insufficient to prevent the deterioration of the AgNW network during V2O5 deposition. On the contrary, crystalline V2O5 films were grown on 30 nm thick ZnO or SnO2-coated AgNWs, exhibiting a typical orange color. Electrochromic characterization demonstrated that only V2O5 films deposited on 30 nm thick SnO2-coated AgNW showed characteristic oxidation-reduction peaks in the Li+-based liquid electrolyte associated with a reversible orange-to-blue color switch for at least 500 cycles. The electrochromic key properties of AgNW/SnO2 (30 nm)/V2O5 films are discussed in terms of structural and morphological changes due to the AgNW network and the nature and thickness of the two protective oxide coatings.

18.
Mol Ecol Resour ; 23(3): 712-724, 2023 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-36377253

RESUMO

Whole-genome alignment allows researchers to understand the genomic structure and variation among genomes. Approaches based on direct pairwise comparisons of DNA sequences require large computational capacities. As a consequence, pipelines combining tools for orthologous gene identification and synteny have been developed. In this manuscript, we present the latest functionalities implemented in NGSEP 4, to identify orthogroups and perform whole genome alignments. NGSEP implements functionalities for identification of clusters of homologus genes, synteny analysis and whole genome alignment. Our results showed that the NGSEP algorithm for orthogroups identification has competitive accuracy and efficiency in comparison to commonly used tools. The implementation also includes a visualization of the whole genome alignment based on synteny of the orthogroups that were identified, and a reconstruction of the pangenome based on frequencies of the orthogroups among the genomes. NGSEP 4 also includes a new graphical user interface based on the JavaFX technology. We expect that these new developments will be very useful for several studies in evolutionary biology and population genomics.


Assuntos
Genoma , Software , Genômica/métodos , Algoritmos , Metagenômica
19.
Sci Rep ; 11(1): 11193, 2021 05 27.
Artigo em Inglês | MEDLINE | ID: mdl-34045540

RESUMO

PrPC variation at residue 96 (G/S) plays an important role in the epidemiology of chronic wasting disease (CWD) in exposed white-tailed deer populations. In vivo studies have demonstrated the protective effect of serine at codon 96, which hinders the propagation of common CWD strains when expressed in homozygosis and increases the survival period of S96/wt heterozygous deer after challenge with CWD. Previous in vitro studies of the transmission barrier suggested that following a single amplification step, wt and S96 PrPC were equally susceptible to misfolding when seeded with various CWD prions. When we performed serial prion amplification in vitro using S96-PrPC, we observed a reduction in the efficiency of propagation with the Wisc-1 or CWD2 strains, suggesting these strains cannot stably template their conformations on this PrPC once the primary sequence has changed after the first round of replication. Our data shows the S96-PrPC polymorphism is detrimental to prion conversion of some CWD strains. These data suggests that deer homozygous for S96-PrPC may not sustain prion transmission as compared to a deer expressing G96-PrPC.


Assuntos
Cervos/genética , Proteínas Priônicas/química , Doença de Emaciação Crônica/etiologia , Substituição de Aminoácidos , Animais , Proteínas Priônicas/genética , Dobramento de Proteína
20.
Animals (Basel) ; 11(5)2021 May 07.
Artigo em Inglês | MEDLINE | ID: mdl-34067229

RESUMO

Mammary epithelial cells (MECs) in culture are a useful model for elucidating mammary gland metabolism and changes that occur under different nutrient disponibility. MECs were exposed to different treatments: 100% EAA for 8 h and 24 h restriction (R); 2% EAA for 8 h and 24 h R; 2% EAA for 8 h and 24 h + 100% EAA for 8 h and 24 h restriction + re-feeding (R + RF). Western blotting and protein quantification was performed. The Kyoto Encyclopedia of Genes and Genomes (KEGG) software identified the amino acids (AAs) and signaling pathways. The chi-squared test, multiple classification analysis, and analysis of variance were used for the purification and identification of data. Intracellular casein levels were not affected. The KEGG analysis revealed that the important pathways of metabolism of AAs, which were involved in processes related to metabolism and biosynthesis of phenylalanine, tyrosine, and tryptophan (fumarate, acetyl-CoA, and tricarboxylic acid (TCA) cycle), were affected by both R and R + RF treatments, mainly through the glutamic-oxaloacetic transaminase-2 enzyme. Additionally, metabolic processes mediated by the mitochondrial malate dehydrogenase, S-adenosylmethionine synthetase, and asparagine synthase proteins positively regulated the carbohydrate pathway, pyruvate, and TCA cycles, as well as the metabolism of alanine, aspartate, and glutamate metabolism (carbohydrate and TCA cycle). We hypothesized that MECs have the capacity to utilize alternative pathways that ensure the availability of substrates for composing milk proteins.

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