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1.
Nature ; 585(7826): 584-587, 2020 09.
Artigo em Inglês | MEDLINE | ID: mdl-32698191

RESUMO

Coronavirus disease 2019 (COVID-19) has rapidly become a global pandemic and no antiviral drug or vaccine is yet available for the treatment of this disease1-3. Several clinical studies are ongoing to evaluate the efficacy of repurposed drugs that have demonstrated antiviral efficacy in vitro. Among these candidates, hydroxychloroquine (HCQ) has been given to thousands of individuals infected with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2)-the virus that causes COVID-19-worldwide but there is no definitive evidence that HCQ is effective for treating COVID-194-7. Here we evaluated the antiviral activity of HCQ both in vitro and in SARS-CoV-2-infected macaques. HCQ showed antiviral activity in African green monkey kidney cells (Vero E6) but not in a model of reconstituted human airway epithelium. In macaques, we tested different treatment strategies in comparison to a placebo treatment, before and after peak viral load, alone or in combination with azithromycin (AZTH). Neither HCQ nor the combination of HCQ and AZTH showed a significant effect on viral load in any of the analysed tissues. When the drug was used as a pre-exposure prophylaxis treatment, HCQ did not confer protection against infection with SARS-CoV-2. Our findings do not support the use of HCQ, either alone or in combination with AZTH, as an antiviral drug for the treatment of COVID-19 in humans.


Assuntos
Betacoronavirus/efeitos dos fármacos , Infecções por Coronavirus/tratamento farmacológico , Infecções por Coronavirus/virologia , Hidroxicloroquina/uso terapêutico , Pneumonia Viral/tratamento farmacológico , Pneumonia Viral/virologia , Animais , Azitromicina/farmacologia , Azitromicina/uso terapêutico , COVID-19 , Chlorocebus aethiops , Infecções por Coronavirus/patologia , Infecções por Coronavirus/fisiopatologia , Citocinas/sangue , Modelos Animais de Doenças , Feminino , Humanos , Hidroxicloroquina/farmacocinética , Hidroxicloroquina/farmacologia , Técnicas In Vitro , Cinética , Macaca fascicularis , Masculino , Pandemias , Pneumonia Viral/patologia , Pneumonia Viral/fisiopatologia , Profilaxia Pré-Exposição , Mucosa Respiratória/citologia , Mucosa Respiratória/efeitos dos fármacos , Mucosa Respiratória/virologia , SARS-CoV-2 , Fatores de Tempo , Falha de Tratamento , Células Vero , Carga Viral/efeitos dos fármacos , Tratamento Farmacológico da COVID-19
2.
Emerg Infect Dis ; 29(3): 569-575, 2023 03.
Artigo em Inglês | MEDLINE | ID: mdl-36737101

RESUMO

We estimated comparative primary and booster vaccine effectiveness (VE) of SARS-CoV-2 Omicron BA.5 and BA.2 lineages against infection and disease progression. During April-June 2022, we implemented a case-case and cohort study and classified lineages using whole-genome sequencing or spike gene target failure. For the case-case study, we estimated the adjusted odds ratios (aORs) of vaccination using a logistic regression. For the cohort study, we estimated VE against disease progression using a penalized logistic regression. We observed no reduced VE for primary (aOR 1.07 [95% CI 0.93-1.23]) or booster (aOR 0.96 [95% CI 0.84-1.09]) vaccination against BA.5 infection. Among BA.5 case-patients, booster VE against progression to hospitalization was lower than that among BA.2 case-patients (VE 77% [95% CI 49%-90%] vs. VE 93% [95% CI 86%-97%]). Although booster vaccination is less effective against BA.5 than against BA.2, it offers substantial protection against progression from BA.5 infection to severe disease.


Assuntos
Vacinas contra COVID-19 , COVID-19 , Humanos , Portugal , Estudos de Coortes , SARS-CoV-2 , Progressão da Doença
3.
Diabetes Obes Metab ; 25(6): 1495-1502, 2023 06.
Artigo em Inglês | MEDLINE | ID: mdl-36722252

RESUMO

AIM: Glucagon-like peptide 1 receptor agonists (GLP1-RA) reduce atherosclerotic events in patients with type 2 diabetes (T2D) and a high cardiovascular risk. The effect of GLP1-RA to reduce heart failure (HF) has been inconsistent across T2D trials, and individual trials were underpowered to assess the effect of GLP1-RA according to HF history. In this meta-analysis we aim to assess the effect of GLP1-RA in patients with and without HF history in stable ambulatory patients with T2D. METHODS: Random-effects meta-analysis of placebo-controlled trials. The hazard ratio (HR) and 95% confidence intervals (95% CI) were extracted from the treatment effect estimates of HF subgroup analyses reported in each individual study. The primary outcome was a composite of HF hospitalization or cardiovascular death. RESULTS: In total, 54 092 patients with T2D from seven randomized controlled trials were included, of whom 8460 (16%) had HF history. Compared with placebo, GLP1-RA did not reduce the composite of HF hospitalization or cardiovascular death in patients with HF history: HR 0.96, 95% CI: 0.84-1.08, but reduced this outcome in patients without HF history: HR 0.84, 95% CI: 0.76-0.92. GLP1-RA did not reduce all-cause death in patients with HF history: HR 0.98, 95% CI: 0.86-1.11, but reduced mortality in patients without HF history: HR 0.85, 95% CI: 0.79-0.92. GLP1-RA reduced atherosclerotic events regardless of HF history: HR 0.85, 95% CI: 0.75-0.97 with HF, and HR 0.88, 95% CI: 0.83-0.93 without HF. CONCLUSIONS: Treatment with GLP1-RA did not reduce HF hospitalizations and mortality in patients with concomitant T2D and HF, but may prevent new-onset HF and mortality in patients with T2D without HF. The reduction of atherosclerotic events with GLP1-RA was not influenced by HF history status.


Assuntos
Aterosclerose , Sistema Cardiovascular , Diabetes Mellitus Tipo 2 , Insuficiência Cardíaca , Humanos , Diabetes Mellitus Tipo 2/complicações , Diabetes Mellitus Tipo 2/tratamento farmacológico , Hipoglicemiantes/uso terapêutico , Insuficiência Cardíaca/complicações , Insuficiência Cardíaca/epidemiologia , Insuficiência Cardíaca/tratamento farmacológico , Aterosclerose/complicações , Peptídeo 1 Semelhante ao Glucagon/uso terapêutico , Ensaios Clínicos Controlados Aleatórios como Assunto
4.
Cardiology ; 148(3): 239-245, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37285810

RESUMO

BACKGROUND: Thyroid dysfunction is common in patients with heart failure (HF). Impaired conversion of free T4 (FT4) into free T3 (FT3) is thought to occur in these patients, decreasing the availability of FT3 and contributing to HF progression. In HF with preserved ejection fraction (HFpEF), it is not known whether changes in conversion of thyroid hormones (THs) are associated with clinical status and outcomes. OBJECTIVES: The objective of this study was to evaluate the association of FT3/FT4 ratio and TH with clinical, analytical, and echocardiographic parameters, as well as their prognostic impact in individuals with stable HFpEF. METHODS: We evaluated 74 HFpEF participants of the NETDiamond cohort without known thyroid disease. We performed regression modeling to study the associations of TH and FT3/FT4 ratio with clinical, anthropometric, analytical, and echocardiographic parameters, and survival analysis to evaluate associations with the composite of diuretic intensification, urgent HF visit, HF hospitalization, or cardiovascular death over a median follow-up of 2.8 years. RESULTS: The mean age was 73.7 years and 62% were men. The mean FT3/FT4 ratio was 2.63 (standard deviation: 0.43). Subjects with lower FT3/FT4 ratio were more likely to be obese and have atrial fibrillation. Lower FT3/FT4 ratio was associated with higher body fat (ß = -5.60 kg per FT3/FT4 unit, p = 0.034), higher pulmonary arterial systolic pressure (PASP) (ß = -10.26 mm Hg per FT3/FT4 unit, p = 0.002), and lower left ventricular ejection fraction (LVEF) (ß = 3.60% per FT3/FT4 unit, p = 0.008). Lower FT3/FT4 ratio was associated with higher risk for the composite HF outcome (HR = 2.50, 95% CI: 1.04-5.88, per 1-unit decrease in FT3/FT4, p = 0.041). CONCLUSIONS: In patients with HFpEF, lower FT3/FT4 ratio was associated with higher body fat, higher PASP, and lower LVEF. Lower FT3/FT4 predicted a higher risk of diuretic intensification, urgent HF visits, HF hospitalization, or cardiovascular death. These findings suggest that decreased FT4 to FT3 conversion might be a mechanism associated with HFpEF progression.


Assuntos
Insuficiência Cardíaca , Tri-Iodotironina , Masculino , Humanos , Idoso , Feminino , Tiroxina , Volume Sistólico/fisiologia , Função Ventricular Esquerda/fisiologia
5.
Medicina (Kaunas) ; 59(9)2023 Sep 20.
Artigo em Inglês | MEDLINE | ID: mdl-37763804

RESUMO

Background and Objectives: Cardiopulmonary exercise testing (CPET) is a cornerstone of risk stratification in heart failure with reduced ejection fraction (HFrEF). However, there is a paucity of evidence on its predictive power in older patients. The aim of this study was to evaluate the prognostic power of current heart transplantation (HTx) listing criteria in HFrEF stratified according to age groups. Materials and Methods: Consecutive patients with HFrEF undergoing CPET between 2009 and 2018 were followed-up for cardiac death and urgent HTx. Results: CPET was performed in 458 patients with HFrEF. The composite endpoint occurred in 16.8% of patients ≤50 years vs. 14.1% of patients ≥50 years in a 36-month follow-up. Peak VO2 (pVO2), VE/VCO2 slope and percentage of predicted pVO2 were strong independent predictors of outcomes. The International Society for Heart and Lung Transplantation thresholds of pVO2 ≤ 12 mL/kg/min (≤14 if intolerant to ß-blockers), VE/VCO2 slope > 35 and percentage of predicted pVO2 ≤ 50% presented a higher overall diagnostic effectiveness in younger patients (≤50 years). Specific thresholds for each age subgroup outperformed the traditional cut-offs. Conclusions: Personalized age-specific thresholds may contribute to an accurate risk stratification in HFrEF. Further studies are needed to address the gap in evidence between younger and older patients.


Assuntos
Insuficiência Cardíaca , Transplante de Coração , Humanos , Idoso , Teste de Esforço , Volume Sistólico , Coração
6.
PLoS Comput Biol ; 17(3): e1008752, 2021 03.
Artigo em Inglês | MEDLINE | ID: mdl-33647008

RESUMO

Repurposed drugs that are safe and immediately available constitute a first line of defense against new viral infections. Despite limited antiviral activity against SARS-CoV-2, several drugs are being tested as medication or as prophylaxis to prevent infection. Using a stochastic model of early phase infection, we evaluate the success of prophylactic treatment with different drug types to prevent viral infection. We find that there exists a critical efficacy that a treatment must reach in order to block viral establishment. Treatment by a combination of drugs reduces the critical efficacy, most effectively by the combination of a drug blocking viral entry into cells and a drug increasing viral clearance. Below the critical efficacy, the risk of infection can nonetheless be reduced. Drugs blocking viral entry into cells or enhancing viral clearance reduce the risk of infection more than drugs that reduce viral production in infected cells. The larger the initial inoculum of infectious virus, the less likely is prevention of an infection. In our model, we find that as long as the viral inoculum is smaller than 10 infectious virus particles, viral infection can be prevented almost certainly with drugs of 90% efficacy (or more). Even when a viral infection cannot be prevented, antivirals delay the time to detectable viral loads. The largest delay of viral infection is achieved by drugs reducing viral production in infected cells. A delay of virus infection flattens the within-host viral dynamic curve, possibly reducing transmission and symptom severity. Thus, antiviral prophylaxis, even with reduced efficacy, could be efficiently used to prevent or alleviate infection in people at high risk.


Assuntos
Antivirais/uso terapêutico , Tratamento Farmacológico da COVID-19 , COVID-19/prevenção & controle , SARS-CoV-2 , Antivirais/administração & dosagem , Número Básico de Reprodução/estatística & dados numéricos , COVID-19/transmissão , COVID-19/virologia , Biologia Computacional , Reposicionamento de Medicamentos , Quimioterapia Combinada , Interações entre Hospedeiro e Microrganismos/efeitos dos fármacos , Interações entre Hospedeiro e Microrganismos/imunologia , Humanos , Modelos Biológicos , Pandemias/prevenção & controle , Prevenção Primária/métodos , Fatores de Risco , SARS-CoV-2/efeitos dos fármacos , SARS-CoV-2/patogenicidade , SARS-CoV-2/fisiologia , Processos Estocásticos , Fatores de Tempo , Resultado do Tratamento , Carga Viral/efeitos dos fármacos , Internalização do Vírus/efeitos dos fármacos , Replicação Viral/efeitos dos fármacos
7.
PLoS Comput Biol ; 17(3): e1008785, 2021 03.
Artigo em Inglês | MEDLINE | ID: mdl-33730053

RESUMO

Non-human primates infected with SARS-CoV-2 exhibit mild clinical signs. Here we used a mathematical model to characterize in detail the viral dynamics in 31 cynomolgus macaques for which nasopharyngeal and tracheal viral load were frequently assessed. We identified that infected cells had a large burst size (>104 virus) and a within-host reproductive basic number of approximately 6 and 4 in nasopharyngeal and tracheal compartment, respectively. After peak viral load, infected cells were rapidly lost with a half-life of 9 hours, with no significant association between cytokine elevation and clearance, leading to a median time to viral clearance of 10 days, consistent with observations in mild human infections. Given these parameter estimates, we predict that a prophylactic treatment blocking 90% of viral production or viral infection could prevent viral growth. In conclusion, our results provide estimates of SARS-CoV-2 viral kinetic parameters in an experimental model of mild infection and they provide means to assess the efficacy of future antiviral treatments.


Assuntos
COVID-19/virologia , Macaca fascicularis/virologia , SARS-CoV-2/fisiologia , Animais , Antivirais/farmacologia , Número Básico de Reprodução , COVID-19/sangue , COVID-19/prevenção & controle , Citocinas/sangue , Modelos Animais de Doenças , Nasofaringe/virologia , SARS-CoV-2/efeitos dos fármacos , Traqueia/virologia , Carga Viral , Replicação Viral/efeitos dos fármacos
8.
Diabetes Obes Metab ; 24(8): 1676-1680, 2022 08.
Artigo em Inglês | MEDLINE | ID: mdl-35373878

RESUMO

Our aim was to study the effect of glucagon-like peptide-1 receptor agonists (GLP-1 RA) on the risk of any cardiovascular event in adults with overweight or obesity and without diabetes. We conducted a random-effects meta-analysis of placebo-controlled randomized controlled trials. Nine trials were eligible and, in total, 11 430 patients were included, of which 7702 (67%) were submitted to treatment with GLP-1 RA. During follow-up, 673 participants receiving GLP-1 RA treatment (8.7%) and 416 participants receiving placebo (11.2%) had a cardiovascular event. Treatment with GLP-1 RA versus placebo resulted in a reduction in the risk of any cardiovascular event (RR = 0.81, CI 0.70-0.92; p = .001). In overweight or obese adults without diabetes, treatment with GLP-1 RA reduced the risk of cardiovascular events. Our findings support the use of GLP-1 RA for reducing the cardiovascular risk of these patients.


Assuntos
Doenças Cardiovasculares , Receptor do Peptídeo Semelhante ao Glucagon 1 , Obesidade , Sobrepeso , Adulto , Doenças Cardiovasculares/prevenção & controle , Diabetes Mellitus/epidemiologia , Peptídeo 1 Semelhante ao Glucagon/uso terapêutico , Receptor do Peptídeo Semelhante ao Glucagon 1/agonistas , Humanos , Obesidade/tratamento farmacológico , Sobrepeso/tratamento farmacológico , Ensaios Clínicos Controlados Aleatórios como Assunto
9.
J Viral Hepat ; 28(2): 383-392, 2021 02.
Artigo em Inglês | MEDLINE | ID: mdl-33074571

RESUMO

Hepatitis B virus RNA (HBV RNA)-containing particles are encapsidated pre-genomic RNA (pgRNA) detectable in chronically infected patients in addition to virions (HBV DNA) that have been suggested as a marker of the treatment efficacy. This makes promising the use of core protein allosteric modulators, such as RG7907, which disrupt the nucleocapsid assembly and profoundly reduce HBV RNA. Here, we developed a multiscale model of HBV extending the standard viral dynamic models to analyse the kinetics of HBV DNA and HBV RNA in 35 patients treated with RG7907 for 28 days. We compare the predictions with those obtained in patients treated with the nucleotide analog tenofovir. RG7907 blocked 99.3% of pgRNA encapsidation (range: 92.1%-99.9%) which led to a decline of both HBV DNA and HBV RNA. As a consequence of its mode of action, the first phase of decline of HBV RNA was rapid, uncovering the clearance of viral particles with half-life of 45 min. In contrast, HBV DNA decline was predicted to be less rapid, due to the continuous secretion of already formed viral capsids (t1/2  = 17 ± 6 h). After few days, both markers declined at the same rate, which was attributed to the loss of infected cells (t1/2  â‰… 6 ± 0.8 days). By blocking efficiently RNA reverse transcription but not its encapsidation, nucleotide analog in contrast was predicted to lead to a transient accumulation of HBV RNA both intracellularly and extracellularly. The model brings a conceptual framework for understanding the differences between HBV DNA and HBV RNA dynamics. Integration of HBV RNA in viral dynamic models may be helpful to better quantify the treatment effect, especially in viral-suppressed patients where HBV DNA is no longer detectable.


Assuntos
Vírus da Hepatite B , RNA Viral , DNA Viral , Vírus da Hepatite B/genética , Humanos , Vírion , Replicação Viral
10.
Br J Clin Pharmacol ; 87(9): 3439-3450, 2021 09.
Artigo em Inglês | MEDLINE | ID: mdl-32693436

RESUMO

AIM: We hypothesized that viral kinetic modelling could be helpful to prioritize rational drug combinations for COVID-19. The aim of this research was to use a viral cell cycle model of SARS-CoV-2 to explore the potential impact drugs, or combinations of drugs, that act at different stages in the viral life cycle might have on various metrics of infection outcome relevant in the early stages of COVID-19 disease. METHODS: Using a target-cell limited model structure that has been used to characterize viral load dynamics from COVID-19 patients, we performed simulations to inform on the combinations of therapeutics targeting specific rate constants. The endpoints and metrics included viral load area under the curve (AUC), duration of viral shedding and epithelial cells infected. Based on the known kinetics of the SARS-CoV-2 life cycle, we rank ordered potential targeted approaches involving repurposed, low-potency agents. RESULTS: Our simulations suggest that targeting multiple points central to viral replication within infected host cells or release from those cells is a viable strategy for reducing both viral load and host cell infection. In addition, we observed that the time-window opportunity for a therapeutic intervention to effect duration of viral shedding exceeds the effect on sparing epithelial cells from infection or impact on viral load AUC. Furthermore, the impact on reduction on duration of shedding may extend further in patients who exhibit a prolonged shedder phenotype. CONCLUSIONS: Our work highlights the use of model-informed drug repurposing approaches to better rationalize effective treatments for COVID-19.


Assuntos
Tratamento Farmacológico da COVID-19 , Reposicionamento de Medicamentos , SARS-CoV-2 , Combinação de Medicamentos , Humanos , Cinética , SARS-CoV-2/efeitos dos fármacos
11.
Br J Clin Pharmacol ; 87(9): 3425-3438, 2021 09.
Artigo em Inglês | MEDLINE | ID: mdl-33373059

RESUMO

AIMS: We propose the use of in silico mathematical models to provide insights that optimize therapeutic interventions designed to effectively treat respiratory infection during a pandemic. A modelling and simulation framework is provided using SARS-CoV-2 as an example, considering applications for both treatment and prophylaxis. METHODS: A target cell-limited model was used to quantify the viral infection dynamics of SARS-CoV-2 in a pooled population of 105 infected patients. Parameter estimates from the resulting model were used to simulate and compare the impact of various interventions against meaningful viral load endpoints. RESULTS: Robust parameter estimates were obtained for the basic reproduction number, viral release rate and infected-cell mortality from the infection model. These estimates were informed by the largest dataset currently available for SARS-CoV-2 viral time course. The utility of this model was demonstrated using simulations, which hypothetically introduced inhibitory or stimulatory drug mechanisms at various target sites within the viral life-cycle. We show that early intervention is crucial to achieving therapeutic benefit when monotherapy is administered. In contrast, combination regimens of two or three drugs may provide improved outcomes if treatment is initiated late. The latter is relevant to SARS-CoV-2, where the period between infection and symptom onset is relatively long. CONCLUSIONS: The use of in silico models can provide viral load predictions that can rationalize therapeutic strategies against an emerging viral pathogen.


Assuntos
Tratamento Farmacológico da COVID-19 , SARS-CoV-2 , Simulação por Computador , Humanos , Pandemias , SARS-CoV-2/efeitos dos fármacos , Carga Viral
12.
Euro Surveill ; 26(10)2021 03.
Artigo em Inglês | MEDLINE | ID: mdl-33706862

RESUMO

We show that the SARS-CoV-2 B.1.1.7 lineage is highly disseminated in Portugal, with the odds of B.1.1.7 proportion increasing at an estimated 89% (95% confidence interval: 83-95%) per week until week 3 2021. RT-PCR spike gene target late detection (SGTL) can constitute a useful surrogate to track B.1.1.7 spread, besides the spike gene target failure (SGTF) proxy. SGTL/SGTF samples were associated with statistically significant higher viral loads, but not with substantial shift in age distribution compared to non-SGTF/SGTL cases.


Assuntos
COVID-19/virologia , SARS-CoV-2/genética , COVID-19/transmissão , Humanos , Portugal/epidemiologia , Glicoproteína da Espícula de Coronavírus/genética
13.
Int Ophthalmol ; 41(1): 243-255, 2021 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-32845463

RESUMO

PURPOSE: To evaluate the feasibility and effects of the intrastromal implantation of chemically modified corneal stroma obtained from chicken into the corneas of rabbits for corneal thickening. METHODS: Chicken corneas were cut, debrided, treated with cross-linking and implanted in an intrastromal pouch created in the cornea of 10 white New Zealand rabbits with femtosecond laser. Slit-lamp biomicroscopy and optical coherence tomography were performed immediately, 7, 30 and 90 days postoperatively. Corneas were removed at 90 days and cut in two halves. One half was sent to histological analysis for the presence of necrosis, polymorphonuclear inflammatory cells, blood vessels and fibrosis, while the other half was evaluated with transmission electron microscopy to verify tissue organization and the presence of keratocytes and inflammatory cells. Corneal thicknesses were comparatively analyzed over time with Wilcoxon test (p ≤ 0.05). RESULTS: The chicken grafts were incorporated into the cornea of all animals over time. Mean rabbit cornea thickness increased from 338 µm preoperatively to 538 µm (p < 0.0077) at 90 days, while mean chicken graft thickness decreased from 350 to 215 µm (p < 0.0077). No clear signs of rejection attributable to the xenograft were observed in any of the implanted eyes. However, some macroscopic and histological events were observed in some of the eyes, probably due to procedural issues during implantation. CONCLUSION: The intrastromal implantation of chicken grafts was shown to be feasible and predictable to thicken the recipient rabbit cornea without apparent rejection. However, before being considered in humans, further meticulous clinical trials are required to establish the clinical utility, safety and efficacy of xenografts for the treatment of patients with advanced keratoconus.


Assuntos
Transplante de Córnea , Ceratocone , Animais , Galinhas , Córnea/cirurgia , Substância Própria/cirurgia , Humanos , Coelhos
14.
Biotechnol Bioeng ; 117(10): 2944-2956, 2020 10.
Artigo em Inglês | MEDLINE | ID: mdl-32573768

RESUMO

Chemoenzymatic approaches using carbohydrate-active enzymes (CAZymes) offer a promising avenue for the synthesis of glycans like oligosaccharides. Here, we report a novel chemoenzymatic route for cellodextrins synthesis employed by chimeric CAZymes, akin to native glycosyltransferases, involving the unprecedented participation of a "non-catalytic" lectin-like domain or carbohydrate-binding modules (CBMs) in the catalytic step for glycosidic bond synthesis using ß-cellobiosyl donor sugars as activated substrates. CBMs are often thought to play a passive substrate targeting role in enzymatic glycosylation reactions mostly via overcoming substrate diffusion limitations for tethered catalytic domains (CDs) but are not known to participate directly in any nucleophilic substitution mechanisms that impact the actual glycosyl transfer step. This study provides evidence for the direct participation of CBMs in the catalytic reaction step for ß-glucan glycosidic bonds synthesis enhancing activity for CBM-based CAZyme chimeras by >140-fold over CDs alone. Dynamic intradomain interactions that facilitate this poorly understood reaction mechanism were further revealed by small-angle X-ray scattering structural analysis along with detailed mutagenesis studies to shed light on our current limited understanding of similar transglycosylation-type reaction mechanisms. In summary, our study provides a novel strategy for engineering similar CBM-based CAZyme chimeras for the synthesis of bespoke oligosaccharides using simple activated sugar monomers.


Assuntos
Proteínas de Bactérias/metabolismo , Celulase/metabolismo , Clostridium thermocellum/enzimologia , Oligossacarídeos/metabolismo , Polissacarídeos/metabolismo , Proteínas de Bactérias/química , Sítios de Ligação , Domínio Catalítico , Celulase/química , Cristalografia por Raios X , Glicosilação , Modelos Moleculares , Oligossacarídeos/química , Polissacarídeos/química , Conformação Proteica , Especificidade por Substrato
15.
Am J Otolaryngol ; 41(6): 102694, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32854041

RESUMO

PURPOSE: Head and neck surgeons are among the highest risk for COVID-19 exposure, which also brings great risk to their mental wellbeing. In this study, we aim to evaluate mental health symptoms among head and neck surgeons in Brazil surrounding the time it was declared the epicenter of the virus. MATERIALS AND METHODS: A cross-sectional, survey-based study evaluating burnout, anxiety, distress, and depression among head and neck surgeons in Brazil, assessed through the single-item Mini-Z burnout assessment, 7-item Generalized Anxiety Disorder scale, 22-item Impact of Event Scale-Revised, and 2-item Patient Health Questionnaire, respectively. RESULTS: 163 physicians completed the survey (74.2% males). Anxiety, distress, burnout, and depression symptoms were reported in 74 (45.5%), 43 (26.3%), 24 (14.7%), and 26 (16.0%) physicians, respectively. On multivariable analysis, female physicians were more likely to report a positive screening for burnout compared to males (OR 2.88, CI [1.07-7.74]). Physicians 45 years or older were less likely to experience anxiety symptoms than those younger than 45 years (OR 0.40, CI [0.20-0.81]). Physicians with no self-reported prior psychiatric conditions were less likely to have symptoms of distress compared to those with such history (OR 0.11, CI [0.33-0.38]). CONCLUSION: Head and neck surgeons in Brazil reported symptoms of burnout, anxiety, distress and depression during our study period within the COVID-19 pandemic. Institutions should monitor these symptoms throughout the pandemic. Further study is required to assess the long-term implications for physician wellness.


Assuntos
Ansiedade/epidemiologia , Esgotamento Profissional/epidemiologia , Infecções por Coronavirus/epidemiologia , Depressão/epidemiologia , Estresse Ocupacional/epidemiologia , Otorrinolaringologistas/psicologia , Pneumonia Viral/epidemiologia , Cirurgiões/psicologia , Adulto , Fatores Etários , Idoso , Betacoronavirus , Brasil/epidemiologia , COVID-19 , Estudos Transversais , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Pandemias , SARS-CoV-2 , Fatores Sexuais , Estresse Psicológico/epidemiologia , Inquéritos e Questionários
16.
Electrophoresis ; 40(14): 1830-1838, 2019 07.
Artigo em Inglês | MEDLINE | ID: mdl-31111973

RESUMO

This paper reports a method for label-free single-cell biophysical analysis of multiple cells trapped in suspension by electrokinetic forces. Tri-dimensional pillar electrodes arranged along the width of a microfluidic chamber define actuators for single cell trapping and selective release by electrokinetic force. Moreover, a rotation can be induced on the cell in combination with a negative DEP force to retain the cell against the flow. The measurement of the rotation speed of the cell as a function of the electric field frequency define an electrorotation spectrum that allows to study the dielectric properties of the cell. The system presented here shows for the first time the simultaneous electrorotation analysis of multiple single cells in separate micro cages that can be selectively addressed to trap and/or release the cells. Chips with 39 micro-actuators of different interelectrode distance were fabricated to study cells with different sizes. The extracted dielectric properties of Henrietta Lacks, human embryonic kidney 293, and human immortalized T lymphocytes cells were found in agreements with previous findings. Moreover, the membrane capacitance of M17 neuroblastoma cells was investigated and found to fall in in the range of 7.49 ± 0.39 mF/m2 .


Assuntos
Dispositivos Lab-On-A-Chip , Análise de Célula Única , Condutividade Elétrica , Técnicas Eletroquímicas , Humanos , Dióxido de Silício/química
17.
Eur Arch Otorhinolaryngol ; 276(7): 2047-2053, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-31161362

RESUMO

PURPOSE: Many authors have described clinicopathologic parameters as factors related to cervical lymph node metastasis development in CN0 stage lip cancer. However, predictive factors for occult lymph node metastasis and criteria for elective neck dissection, especially for early tumour, remain undefined. METHODS: A multi-institutional study with 193 consecutive patients with early lip SCC treated from January 1990 to March 2006 was carried out retrospectively to determine factors predicting occult metastasis. RESULTS: The overall late LNM rate was 13% (25/193). In the multivariate logistic regression study, tumour size and pattern of tumour invasion were factors related to the occurrence of late LNM with rates of sensitivity, specifity and accuracy for occult LNM prediction of 50%, 89.5% and 87%, respectively. CONCLUSION: Our results indicate that patients with stage I and II SCC of the lip with tumour size greater than 18 mm and more aggressive pattern of invasion must be considered a high-risk group for LNM and an END should be performed.


Assuntos
Carcinoma de Células Escamosas , Neoplasias Labiais , Esvaziamento Cervical/métodos , Adulto , Idoso , Idoso de 80 Anos ou mais , Brasil , Carcinoma de Células Escamosas/diagnóstico , Carcinoma de Células Escamosas/patologia , Procedimentos Cirúrgicos Eletivos/métodos , Feminino , Humanos , Neoplasias Labiais/diagnóstico , Neoplasias Labiais/patologia , Modelos Logísticos , Linfonodos/patologia , Linfonodos/cirurgia , Metástase Linfática/patologia , Masculino , Pessoa de Meia-Idade , Pescoço , Invasividade Neoplásica , Estadiamento de Neoplasias , Prognóstico , Estudos Retrospectivos , Carga Tumoral
18.
Cardiol Young ; 29(12): 1445-1451, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31623696

RESUMO

INTRODUCTION: Both transposition of the great arteries (TGA) previously submitted to a Senning/Mustard procedure and congenitally corrected TGA (cc-TGA) have the systemic circulation supported by the morphological right ventricle, thereby rendering these patients to heart failure events risk. The aim of this study was to evaluate cardiopulmonary exercise test parameters for stratifying the risk of heart failure events in TGA patients. METHODS: Retrospective evaluation of adult TGA patients with systemic circulation supported by the morphological right ventricle submitted to cardiopulmonary exercise test in a tertiary centre. Patients were followed up for at least 1 year for the primary endpoint of cardiac death or heart failure hospitalisation. Several cardiopulmonary exercise test parameters were analysed as potential predictors of the combined endpoint and their predictive power were compared (area under the curve). RESULTS: Cardiopulmonary exercise test was performed in 44 TGA patients (8 cc-TGA), with a mean age of 35.1 ± 8.4 years. The primary endpoint was reached by 10 (22.7%) patients, with a mean follow-up of 36.7 ± 26.8 months. Heart rate at anaerobic threshold had the highest area under the curve value (0.864), followed by peak oxygen consumption (pVO2) (0.838). Heart rate at anaerobic threshold ≤95 bpm and pVO2 ≤20 ml/kg/min had a sensitivity of 87.5 and 80.0% and a specificity of 82.4 and 76.5%, respectively, for the primary outcome. CONCLUSION: Heart rate at anaerobic threshold ≤95 bpm had the highest predictive power of all cardiopulmonary exercise test parameters analysed for heart failure events in TGA patients with systemic circulation supported by the morphological right ventricle.


Assuntos
Limiar Anaeróbio/fisiologia , Transposição dos Grandes Vasos/fisiopatologia , Disfunção Ventricular Direita/fisiopatologia , Adulto , Teste de Esforço/métodos , Feminino , Insuficiência Cardíaca/mortalidade , Insuficiência Cardíaca/fisiopatologia , Humanos , Masculino , Pessoa de Meia-Idade , Portugal/epidemiologia , Prognóstico , Estudos Retrospectivos , Medição de Risco/métodos , Centros de Atenção Terciária , Adulto Jovem
19.
Inorg Chem ; 57(2): 754-767, 2018 Jan 16.
Artigo em Inglês | MEDLINE | ID: mdl-29266938

RESUMO

Recrystallization of amorphous compounds can lead to the stabilization of metastable crystalline phases, which offers an interesting way to unveil novel binary or ternary compounds and control the transport properties of the obtained glass ceramics. Here, we report on a systematic study of the Cu-As-Te glassy system and show that under specific synthesis conditions using the spark-plasma-sintering technique, the α-As2Te3 and ß-As2Te3 binary phases and the previously unreported AsTe3 phase can be selectively crystallized within an amorphous matrix. The microstructures and transport properties of three different glass ceramics, each of them containing one of these phases with roughly the same crystalline fraction (∼30% in volume), were investigated in detail by means of X-ray diffraction, scanning electron microscopy, neutron thermodiffraction, Raman scattering (experimental and lattice-dynamics calculations), and transport-property measurements. The physical properties of the glass ceramics are compared with those of both the parent glasses and the pure crystalline phases that could be successfully synthesized. SEM images coupled with Raman spectroscopy evidence a "coast-to-island" or dendriticlike microstructure with microsized crystallites. The presence of the crystallized phase results in a significant decrease in the electrical resistivity while maintaining the thermal conductivity to low values. This study demonstrates that new compounds with interesting transport properties can be obtained by recrystallization, which in turn provides a tuning parameter for the transport properties of the parent glasses.

20.
Adv Exp Med Biol ; 1049: 255-273, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-29427108

RESUMO

Machado-Joseph disease (MJD) also known as Spinocerebellar ataxia type 3, is a hereditary neurodegenerative disease associated with severe clinical manifestations and premature death. Although rare, it is the most common autosomal dominant spinocerebellar ataxia worldwide and has a distinct geographic distribution, reaching peak prevalence in certain regions of Brazil, Portugal and China. Due to its clinical heterogeneity, it was initially described as several different entities and as had many designations over the last decades. An accurate diagnosis become possible in 1994, after the identification of the MJD1 gene. Among its wide clinical spectrum, progressive cerebellar ataxia is normally present. Other symptoms include pyramidal syndrome, peripheral neuropathy, oculomotor abnormalities, extrapyramidal signs and sleep disorders. On the basis of the presence/absence of important extra-pyramidal signs, and the presence/absence of peripheral signs, five clinical types have been defined. Neuroimaging studies like MRI, DTI and MRS, can be useful as they can characterize structural and functional differences in specific subgroups of patients with MJD. There is no effective treatment for MJD. Symptomatic therapies are used to relieve some of the clinical symptoms and physiotherapy is also helpful in improving quality of live. Several clinical trials have been carried out using different molecules like sulfamethoxazole-trimethoprim, varenicline and lithium carbonate, but the results of these trials were negative or showed little benefit. Future studies sufficiently powered and adequately designed are warranted.


Assuntos
Ataxina-3 , Doença de Machado-Joseph , Neuroimagem , Proteínas Repressoras , Ataxina-3/genética , Ataxina-3/metabolismo , Ensaios Clínicos como Assunto , Humanos , Doença de Machado-Joseph/diagnóstico por imagem , Doença de Machado-Joseph/tratamento farmacológico , Doença de Machado-Joseph/genética , Doença de Machado-Joseph/metabolismo , Proteínas Repressoras/genética , Proteínas Repressoras/metabolismo
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