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1.
Trends Immunol ; 45(6): 419-427, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38762333

RESUMO

The humoral arm of mammalian innate immunity regulates several molecular mechanisms involved in resistance to pathogens, inflammation, and tissue repair. Recent studies highlight the crucial role played by humoral mediators in granulomatous inflammation. However the molecular mechanisms linking the function of these soluble molecules to the initiation and maintenance of granulomas remain elusive. We propose that humoral innate immunity coordinates fundamental physiological processes in macrophages which, in turn, initiate activation and transformation events that enable granuloma formation. We discuss the involvement of humoral mediators in processes such as immune activation, phagocytosis, metabolism, and tissue remodeling, and how these can dictate macrophage functionality during granuloma formation. These advances present opportunities for discovering novel disease factors and developing targeted, more effective treatments for granulomatous diseases.


Assuntos
Granuloma , Imunidade Humoral , Imunidade Inata , Macrófagos , Humanos , Animais , Granuloma/imunologia , Macrófagos/imunologia , Fagocitose/imunologia , Inflamação/imunologia , Transdução de Sinais/imunologia
2.
Trends Biochem Sci ; 45(9): 794-805, 2020 09.
Artigo em Inglês | MEDLINE | ID: mdl-32505636

RESUMO

Viruses rely on the host cell translation machinery for efficient synthesis of their own proteins. Emerging evidence highlights different roles for host transfer RNAs (tRNAs) in the process of virus replication. For instance, different RNA viruses manipulate host tRNA pools to favor viral protein translation. Interestingly, specific host tRNAs are used as reverse transcription primers and are packaged into retroviral virions. Recent data also demonstrate the formation of tRNA-derived fragments (tRFs) upon infection to facilitate viral replication. Here, we comprehensively discuss how RNA viruses exploit distinct aspects of the host tRNA biology for their benefit. In light of the recent advances in the field, we propose that host tRNA-related pathways and mechanisms represent promising cellular targets for the development of novel antiviral strategies.


Assuntos
Infecções por Vírus de RNA , Vírus de RNA , Humanos , Vírus de RNA/genética , RNA de Transferência/genética
3.
J Inherit Metab Dis ; 47(2): 217-219, 2024 03.
Artigo em Inglês | MEDLINE | ID: mdl-38326670

RESUMO

We report the case of a Syrian female refugee with late diagnosis of glutaric aciduria type 1 characterised by massive axial hypotonia and quadriplegia who only started adequate diet upon arrival in Switzerland at the age of 4 years, after a strenuous migration journey. Soon after arrival, she died from an unexpected severe upper cervical myelopathy, heralded by acute respiratory distress after a viral infection. This was likely due to repeated strains on her hypotonic neck and precipitated by an orthotopic os odontoideum who led to atlanto-axial subluxation. This case reminds us not to omit handling patients with insufficient postural control and hypotonia with great care to avoid progressive cervical myelopathy.


Assuntos
Erros Inatos do Metabolismo dos Aminoácidos , Encefalopatias Metabólicas , Glutaril-CoA Desidrogenase , Processo Odontoide , Doenças da Medula Espinal , Pré-Escolar , Feminino , Humanos , Erros Inatos do Metabolismo dos Aminoácidos/complicações , Erros Inatos do Metabolismo dos Aminoácidos/diagnóstico , Glutaril-CoA Desidrogenase/deficiência , Hipotonia Muscular
4.
Am J Respir Cell Mol Biol ; 68(3): 326-338, 2023 03.
Artigo em Inglês | MEDLINE | ID: mdl-36476191

RESUMO

Pulmonary fibrosis (PF) and pulmonary hypertension (PH) are chronic diseases of the pulmonary parenchyma and circulation, respectively, which may coexist, but underlying mechanisms remain elusive. Mutations in the GCN2 (general control nonderepressible 2) gene (EIF2AK4 [eukaryotic translation initiation factor 2 alpha kinase 4]) were recently associated with pulmonary veno-occlusive disease. The aim of this study is to explore the involvement of the GCN2/eIF2α (eukaryotic initiation factor 2α) pathway in the development of PH during PF, in both human disease and in a laboratory animal model. Lung tissue from patients with PF with or without PH was collected at the time of lung transplantation, and control tissue was obtained from tumor resection surgery. Experimental lung disease was induced in either male wild-type or EIF2AK4-mutated Sprague-Dawley rats, randomly receiving a single intratracheal instillation of bleomycin or saline. Hemodynamic studies and organ collection were performed 3 weeks after instillation. Only significant results (P < 0.05) are presented. In PF lung tissue, GCN2 protein expression was decreased compared with control tissue. GCN2 expression was reduced in CD31+ endothelial cells. In line with human data, GCN2 protein expression was decreased in the lung of bleomycin rats compared with saline. EIF2AK4-mutated rats treated with bleomycin showed increased parenchymal fibrosis (hydroxyproline concentrations) and vascular remodeling (media wall thickness) as well as increased right ventricular systolic pressure compared with wild-type animals. Our data show that GCN2 is dysregulated in both humans and in an animal model of combined PF and PH. The possibility of a causative implication of GCN2 dysregulation in PF and/or PH development should be further studied.


Assuntos
Hipertensão Pulmonar , Fibrose Pulmonar , Animais , Humanos , Masculino , Ratos , Bleomicina , Células Endoteliais/patologia , Hipertensão Pulmonar/patologia , Pulmão/patologia , Proteínas Serina-Treonina Quinases/metabolismo , Fibrose Pulmonar/patologia , Ratos Sprague-Dawley
5.
Int J Mol Sci ; 22(6)2021 Mar 14.
Artigo em Inglês | MEDLINE | ID: mdl-33799331

RESUMO

Transfer RNA (tRNA) molecules contain various post-transcriptional modifications that are crucial for tRNA stability, translation efficiency, and fidelity. Besides their canonical roles in translation, tRNAs also originate tRNA-derived small RNAs (tsRNAs), a class of small non-coding RNAs with regulatory functions ranging from translation regulation to gene expression control and cellular stress response. Recent evidence indicates that tsRNAs are also modified, however, the impact of tRNA epitranscriptome deregulation on tsRNAs generation is only now beginning to be uncovered. The 5-methyluridine (m5U) modification at position 54 of cytosolic tRNAs is one of the most common and conserved tRNA modifications among species. The tRNA methyltransferase TRMT2A catalyzes this modification, but its biological role remains mostly unexplored. Here, we show that TRMT2A knockdown in human cells induces m5U54 tRNA hypomodification and tsRNA formation. More specifically, m5U54 hypomodification is followed by overexpression of the ribonuclease angiogenin (ANG) that cleaves tRNAs near the anticodon, resulting in accumulation of 5'tRNA-derived stress-induced RNAs (5'tiRNAs), namely 5'tiRNA-GlyGCC and 5'tiRNA-GluCTC, among others. Additionally, transcriptomic analysis confirms that down-regulation of TRMT2A and consequently m5U54 hypomodification impacts the cellular stress response and RNA stability, which is often correlated with tiRNA generation. Accordingly, exposure to oxidative stress conditions induces TRMT2A down-regulation and tiRNA formation in mammalian cells. These results establish a link between tRNA hypomethylation and ANG-dependent tsRNAs formation and unravel m5U54 as a tRNA cleavage protective mark.


Assuntos
Estresse Oxidativo/genética , RNA de Transferência/genética , Ribonuclease Pancreático/genética , tRNA Metiltransferases/genética , Humanos , Clivagem do RNA/genética , Processamento Pós-Transcricional do RNA/genética , Estabilidade de RNA/genética , Pequeno RNA não Traduzido/genética , RNA de Transferência/química , Estresse Fisiológico/genética , Uridina/análogos & derivados , Uridina/genética
6.
Proc Natl Acad Sci U S A ; 114(42): 11127-11132, 2017 10 17.
Artigo em Inglês | MEDLINE | ID: mdl-28973954

RESUMO

Extracellular vesicles (EVs) are small vesicles released by cells to aid cell-cell communication and tissue homeostasis. Human islet amyloid polypeptide (IAPP) is the major component of amyloid deposits found in pancreatic islets of patients with type 2 diabetes (T2D). IAPP is secreted in conjunction with insulin from pancreatic ß cells to regulate glucose metabolism. Here, using a combination of analytical and biophysical methods in vitro, we tested whether EVs isolated from pancreatic islets of healthy patients and patients with T2D modulate IAPP amyloid formation. We discovered that pancreatic EVs from healthy patients reduce IAPP amyloid formation by peptide scavenging, but T2D pancreatic and human serum EVs have no effect. In accordance with these differential effects, the insulin:C-peptide ratio and lipid composition differ between EVs from healthy pancreas and EVs from T2D pancreas and serum. It appears that healthy pancreatic EVs limit IAPP amyloid formation via direct binding as a tissue-specific control mechanism.


Assuntos
Diabetes Mellitus Tipo 2/metabolismo , Vesículas Extracelulares/fisiologia , Polipeptídeo Amiloide das Ilhotas Pancreáticas/metabolismo , Ilhotas Pancreáticas/metabolismo , Placa Amiloide/metabolismo , Adulto , Idoso , Estudos de Casos e Controles , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Adulto Jovem
7.
Clin Exp Pharmacol Physiol ; 46(3): 255-265, 2019 03.
Artigo em Inglês | MEDLINE | ID: mdl-30339273

RESUMO

We have previously shown that treatment with recombinant human neuregulin-1 (rhNRG-1) improves pulmonary arterial hypertension (PAH) in a monocrotaline (MCT)-induced animal model, by decreasing pulmonary arterial remodelling and endothelial dysfunction, as well as by restoring right ventricular (RV) function. Additionally, rhNRG-1 treatment showed direct myocardial anti-remodelling effects in a model of pressure loading of the RV without PAH. This work aimed to study the intrinsic cardiac effects of rhNRG-1 on experimental PAH and RV pressure overload, and more specifically on diastolic stiffness, at both the ventricular and cardiomyocyte level. We studied the effects of chronic rhNRG-1 treatment on ventricular passive stiffness in RV and LV samples from MCT-induced PAH animals and in the RV from animals with compensated and decompensated RV hypertrophy, through a mild and severe pulmonary artery banding (PAB). We also measured passive tension in isolated cardiomyocytes and quantified the expression of myocardial remodelling-associated genes and calcium handling proteins. Chronic rhNRG-1 treatment decreased passive tension development in RV and LV isolated from animals with MCT-induced PAH. This decrease was associated with increased phospholamban phosphorylation, and with attenuation of the expression of cardiac maladaptive remodelling markers. Finally, we showed that rhNRG-1 therapy decreased RV remodelling and cardiomyocyte passive tension development in PAB-induced RV hypertrophy animals, without compromising cardiac function, pointing to cardiac-specific effects in both hypertrophy stages. In conclusion, we demonstrated that rhNRG-1 treatment decreased RV intrinsic diastolic stiffness, through the improvement of calcium handling and cardiac remodelling signalling.


Assuntos
Diástole/fisiologia , Hipertensão Pulmonar/patologia , Hipertensão Pulmonar/fisiopatologia , Neuregulina-1/farmacologia , Rigidez Vascular/efeitos dos fármacos , Disfunção Ventricular Direita/tratamento farmacológico , Animais , Sinalização do Cálcio/efeitos dos fármacos , Regulação da Expressão Gênica/efeitos dos fármacos , Humanos , Masculino , Miócitos Cardíacos/efeitos dos fármacos , Miócitos Cardíacos/metabolismo , Miócitos Cardíacos/patologia , Neuregulina-1/uso terapêutico , Ratos , Ratos Wistar , Proteínas Recombinantes/farmacologia , Proteínas Recombinantes/uso terapêutico , Remodelação Ventricular/efeitos dos fármacos
8.
Oral Dis ; 25(5): 1291-1301, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-30866167

RESUMO

OBJECTIVES: Bub3 and Spindly are essential proteins required for the activation and inactivation of the spindle assembly checkpoint, respectively. Here, we explored the clinicopathological significance and the therapeutic potential of the opposing roles of the two proteins in oral squamous cell carcinoma (OSCC). MATERIALS AND METHODS: Bub3 and Spindly expression was evaluated by immunohistochemistry in 62 tissue microarrays from OSCC and by real-time PCR in OSCC cell lines and in normal human oral keratinocytes. The results were analyzed as to their clinicopathological significance. RNA interference-mediated Spindly or Bub3 inhibition was combined with cisplatin treatment, and the effect on the viability of OSCC cells was assessed. RESULTS: Overexpression of Bub3 and Spindly was detected in OSCC patients. High expression of Spindly, Bub3, or both was an independent prognostic indicator for cancer-specific survival and was associated with increased cellular proliferation. Accordingly, Bub3 and Spindly were upregulated in OSCC cells comparatively to their normal counterpart. Inhibition of Bub3 or Spindly was cytotoxic to OSCC cells and enhanced their chemosensitivity to cisplatin. CONCLUSIONS: The data point out Bub3 and Spindly as potential markers of proliferation and prognosis, and highlight the potential therapeutic benefit of combining their inhibition with cisplatin.


Assuntos
Carcinoma de Células Escamosas/genética , Proteínas de Ciclo Celular/genética , Neoplasias Bucais/genética , Proteínas de Ligação a Poli-ADP-Ribose/genética , Antineoplásicos , Linhagem Celular Tumoral , Proliferação de Células , Cisplatino , Humanos , Prognóstico
9.
Molecules ; 23(5)2018 05 05.
Artigo em Inglês | MEDLINE | ID: mdl-29734739

RESUMO

Natural flavonoids and xanthone glycosides display several biological activities, with the glycoside moiety playing an important role in the mechanism of action of these metabolites. Herein, to give further insights into the inhibitory activity on cell growth of these classes of compounds, the synthesis of four flavonoids (5, 6, 9, and 10) and one xanthone (7) containing one or more acetoglycoside moieties was carried out. Acetyl groups were introduced using acetic anhydride and microwave irradiation. The introduction of one or two acetoglycoside moieties in the framework of 3,7-dihydroxyflavone (4) was performed using two synthetic methods: the Michael reaction and the Koenigs-Knorr reaction. The in vitro cell growth inhibitory activity of compounds 5, 6, 7, 9, and 10 was investigated in six human tumor cell lines: A375-C5 (malignant melanoma IL-1 insensitive), MCF-7 (breast adenocarcinoma), NCI-H460 (non-small cell lung cancer), U251 (glioblastoma astrocytoma), U373 (glioblastoma astrocytoma), and U87MG (glioblastoma astrocytoma). The new flavonoid 3-hydroxy-7-(2,3,4,6-tetra-O-acetyl-ß-glucopyranosyl) flavone (10) was the most potent compound in all tumor cell lines tested, with GI50 values < 8 µM and a notable degree of selectivity for cancer cells.


Assuntos
Antineoplásicos/síntese química , Astrócitos/efeitos dos fármacos , Células Epiteliais/efeitos dos fármacos , Flavonoides/síntese química , Neuroglia/efeitos dos fármacos , Xantonas/síntese química , Anidridos Acéticos/química , Acetilação , Antineoplásicos/farmacologia , Astrócitos/patologia , Linhagem Celular Tumoral , Sobrevivência Celular/efeitos dos fármacos , Desenho de Fármacos , Células Epiteliais/patologia , Flavonoides/farmacologia , Glicosilação , Humanos , Concentração Inibidora 50 , Células MCF-7 , Micro-Ondas , Neuroglia/patologia , Relação Estrutura-Atividade , Xantonas/farmacologia
10.
Molecules ; 24(1)2018 Dec 31.
Artigo em Inglês | MEDLINE | ID: mdl-30602686

RESUMO

The antitumor activity of natural flavonoids has been exhaustively reported. Previously it has been demonstrated that prenylation of flavonoids allows the discovery of new compounds with improved antitumor activity through the activation of caspase-7 activity. The synthesis of twenty-five flavonoids (4⁻28) with one or more alkyl side chains was carried out. The synthetic approach was based on the reaction with alkyl halide in alkaline medium by microwave (MW) irradiation. The in vitro cell growth inhibitory activity of synthesized compounds was investigated in three human tumor cell lines. Among the tested compounds, derivatives 6, 7, 9, 11, 13, 15, 17, and 18 revealed potent growth inhibitory activity (GI50 < 10 µM), being the growth inhibitory effect of compound 13 related with a pronounced caspase-7 activation on MCF-7 breast cancer cells and yeasts expressing human caspase-7. A quantitative structure-activity relationship (QSAR) model predicted that hydrophilicity, pattern of ring substitution/shape, and presence of partial negative charged atoms were the descriptors implied in the growth inhibitory effect of synthesized compounds. Docking studies on procaspase-7 allowed predicting the binding of compound 13 to the allosteric site of procaspase-7.


Assuntos
Antineoplásicos/síntese química , Caspase 7/metabolismo , Inibidores de Caspase/síntese química , Flavonas/síntese química , Antineoplásicos/química , Antineoplásicos/farmacologia , Inibidores de Caspase/química , Inibidores de Caspase/farmacologia , Ciclo Celular/efeitos dos fármacos , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Relação Dose-Resposta a Droga , Ensaios de Seleção de Medicamentos Antitumorais , Flavonas/química , Flavonas/farmacologia , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Humanos , Células MCF-7 , Simulação de Acoplamento Molecular , Estrutura Molecular , Relação Quantitativa Estrutura-Atividade
11.
Rev Med Suisse ; 12(539): 1958-1965, 2016 Nov 16.
Artigo em Francês | MEDLINE | ID: mdl-28696637

RESUMO

Eosinophilic pneumonia is characterized by pulmonary eosinophilia associated with and/or alveolar eosinophilia. Furthermore, blood eosinophilia may be absent particularly in patients who have benefited beforehand of corticosteroids. The most common causes are parasites and drugs. According to the classification, we distinguish idiopathic pneumonia with eosinophils, those related to vasculitis and those of known etiology. Extrapulmonary involvement is frequently found in the subgroup of vasculitis. It is important to diagnose and start treatment quickly to reduce the risk of complications. The primary treatment is based on corticosteroids and in severe cases of vasculitis immunosuppressants are necessary.


Les pneumopathies à éosinophiles se caractérisent par une atteinte pulmonaire associée à une éosinophilie alvéolaire et/ou une éosinophilie sanguine. Par ailleurs, l'éosinophilie sanguine peut être absente, notamment chez les patients qui sont au bénéfice d'une corticothérapie au préalable. Les étiologies les plus courantes sont les parasites et les médicaments. Selon la classification, on distingue les pneumopathies à éosinophiles idiopathiques, celles liées à une vascularite et celles d'étiologie secondaire. Une atteinte extrapulmonaire est fréquemment retrouvée dans le sous-groupe des vascularites. Il est important de poser le diagnostic et de débuter le traitement rapidement afin de diminuer le risque de complications. Le traitement primaire est basé sur la corticothérapie. Alors que dans les cas sévères ou les vasculites, les immunosuppresseurs sont nécessaires.


Assuntos
Corticosteroides/uso terapêutico , Imunossupressores/uso terapêutico , Eosinofilia Pulmonar/diagnóstico , Humanos , Eosinofilia Pulmonar/complicações , Eosinofilia Pulmonar/tratamento farmacológico , Vasculite/diagnóstico , Vasculite/tratamento farmacológico
12.
Eur J Pediatr ; 174(7): 911-7, 2015 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-25573461

RESUMO

UNLABELLED: Glucocorticosteroids (GCs) are the first-line treatment for idiopathic nephrotic syndrome (NS), but prolonged administration interferes with growth and bone mineralization. We conducted a retrospective study to analyze the long-term impact of prednisone on growth and bone mineral density (BMD) in children with NS. Data from children with NS followed during almost 10 years were analyzed. Height and spine BMD values were converted to Z-scores (standard deviation [SD]). The mean cumulative dose of GCs received was calculated and correlated to patient's growth and spine BMD using linear regression and subgroup analysis. We included 30 patients diagnosed at 3.7 years old (interquartile range (IQR) 2.6-4.8) and followed over 9.8 years (IQR 6.6-11.7). The one half of NS patients was steroid sensitive and one half dependent or resistant. The median cumulative dose of GCs received was 0.27 mg/kg/day (IQR 0.18-0.35). Growth and spine BMD were both negatively associated with the cumulative dose of GCs (P=0.001 and P=0.037, respectively). Final height Z-scores were significantly lower in patients receiving >0.2 mg/kg/day GCs (P=0.001). No difference was observed in spine BMD between subgroups. CONCLUSION: Increasing doses of GCs were significantly associated with lower height and BMD Z-scores. A significant effect on growth was observed with cutoff doses above 0.2 mg/kg/day.


Assuntos
Estatura/efeitos dos fármacos , Densidade Óssea/efeitos dos fármacos , Glucocorticoides/efeitos adversos , Síndrome Nefrótica/tratamento farmacológico , Prednisona/efeitos adversos , Absorciometria de Fóton , Criança , Relação Dose-Resposta a Droga , Feminino , Seguimentos , Glucocorticoides/administração & dosagem , Humanos , Masculino , Prednisona/administração & dosagem , Estudos Retrospectivos
13.
iScience ; 27(3): 109100, 2024 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-38405606

RESUMO

Influenza A virus (IAV) employs multiple strategies to manipulate cellular mechanisms and support proper virion formation and propagation. In this study, we performed a detailed analysis of the interplay between IAV and the host cells' proteostasis throughout the entire infectious cycle. We reveal that IAV infection activates the inositol requiring enzyme 1 (IRE1) branch of the unfolded protein response, and that this activation is important for an efficient infection. We further observed the accumulation of virus-induced insoluble protein aggregates, containing both viral and host proteins, associated with a dysregulation of the host cell RNA metabolism. Our data indicate that this accumulation is important for IAV propagation and favors the final steps of the infection cycle, more specifically the virion assembly. These findings reveal additional mechanisms by which IAV disrupts host proteostasis and uncovers new cellular targets that can be explored for the development of host-directed antiviral strategies.

14.
ESC Heart Fail ; 2024 Mar 28.
Artigo em Inglês | MEDLINE | ID: mdl-38549183

RESUMO

AIMS: Acute myocardial infarction (AMI) resulting from unprotected left main coronary artery (LMCA) occlusion and subtotal occlusion is a life-threatening condition. Although AMI management has improved in the past two decades, there is limited information on recent trends in patient characteristics, management, and outcomes for acute unprotected LMCA-related AMI. This study aims to assess such trends over a 12 year period. METHODS AND RESULTS: This retrospective multicentre study includes patients with unprotected LMCA occlusion/subtotal occlusion admitted to three tertiary hospitals between 2008 and 2020. The patients were divided into two groups based on the chronology of presentation: a 'past group' (January 2008 to December 2014) and a 'contemporary group' (January 2015 to December 2020). The study compares clinical characteristics, management approaches, and outcomes between the two groups. The study includes 128 patients, with 51 (40%) in the 'past group' and 77 (60%) in the 'contemporary group'. Baseline risk factors did not show statistically significant differences between the two groups, except for hypertension (49% vs. 74%; P = 0.005). Chest pain was more frequent in the 'past group' (98% vs. 89%; P = 0.014), and a trend towards more cardiac arrests was observed in the 'contemporary group' (18% vs. 31%; P = 0.087). Revascularization type did not differ significantly (P = 0.419), but manual thrombectomy was less frequently used (41% vs. 23%; P = 0.032) and stent implantation showed a trend towards higher rates (66% vs. 78%; P = 0.150) in the 'contemporary cohort'. There was a gradual shift from bare-metal to drug-eluting stents, with a significantly higher percentage of ticagrelor/prasugrel loading in the 'contemporary cohort' (5% vs. 79%; P < 0.001). The use of mechanical circulatory support (MCS), although not statistically significant, was higher among patients in the 'past group' (67% vs. 51%; P = 0.073). The type of MCS differed significantly between groups, with a decrease in intra-aortic balloon pump use (67% vs. 42%; P = 0.005) and an increase in veno-arterial extracorporeal membrane oxygenation (4% vs. 22%; P = 0.005) and Impella system (0% vs. 3%) over time. Survival analysis showed no significant differences (P = 0.599; log-rank test) in all-cause mortality between the different time groups, with the long-term survival rate being approximately 30%. CONCLUSIONS: In our real-world population, despite the progressive use of newer drugs and more advanced devices over time, patients with unprotected LMCA occlusion/subtotal occlusion remain a subpopulation with poor prognosis.

15.
Front Genet ; 14: 1245683, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37614818

RESUMO

Emerging evidence highlights the multifaceted roles of the RNA epitranscriptome during viral infections. By modulating the modification landscape of viral and host RNAs, viruses enhance their propagation and elude host surveillance mechanisms. Here, we discuss how specific RNA modifications, in either host or viral RNA molecules, impact the virus-life cycle and host antiviral responses, highlighting the potential of targeting the RNA epitranscriptome for novel antiviral therapies.

16.
J Struct Biol X ; 7: 100084, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-36660365

RESUMO

The Bacteroides thetaiotaomicron has developed a consortium of enzymes capable of overcoming steric constraints and degrading, in a sequential manner, the complex rhamnogalacturonan II (RG-II) polysaccharide. BT0996 protein acts in the initial stages of the RG-II depolymerisation, where its two catalytic modules remove the terminal monosaccharides from RG-II side chains A and B. BT0996 is modular and has three putative carbohydrate-binding modules (CBMs) for which the roles in the RG-II degradation are unknown. Here, we present the characterisation of the module at the C-terminal domain, which we designated BT0996-C. The high-resolution structure obtained by X-ray crystallography reveals that the protein displays a typical ß-sandwich fold with structural similarity to CBMs assigned to families 6 and 35. The distinctive features are: 1) the presence of several charged residues at the BT0996-C surface creating a large, broad positive lysine-rich patch that encompasses the putative binding site; and 2) the absence of the highly conserved binding-site signatures observed in CBMs from families 6 and 35, such as region A tryptophan and region C asparagine. These findings hint at a binding mode of BT0996-C not yet observed in its homologues. In line with this, carbohydrate microarrays and microscale thermophoresis show the ability of BT0996-C to bind α1-4-linked polygalacturonic acid, and that electrostatic interactions are essential for the recognition of the anionic polysaccharide. The results support the hypothesis that BT0996-C may have evolved to potentiate the action of BT0996 catalytic modules on the complex structure of RG-II by binding to the polygalacturonic acid backbone sequence.

17.
J Cardiovasc Dev Dis ; 10(9)2023 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-37754803

RESUMO

The clinical presentation of pulmonary embolism (PE) and acute coronary syndrome can be similar. We report a case of a patient presenting with antero-septal ST-segment elevation after cardiac arrest, found to have acute-PE-mimicking ST-segment elevation myocardial infarction (STEMI), treated with aspiration thrombectomy and catheter-directed thrombolysis (CDT). A 78-year-old man was admitted with dyspnea, chest pain and tachycardia. During evaluation, cardiac arrest in pulseless electrical activity was documented. Advanced life support was started immediately. ECG post-ROSC revealed ST-segment elevation in V1-V4 and aVR. Echocardiography showed normal left ventricular function but right ventricular (RV) dilation and severe dysfunction. The patient was in shock and was promptly referred to cardiac catheterization that excluded significant CAD. Due to the discordant ECG and echocardiogram findings, acute PE was suspected, and immediate invasive pulmonary angiography revealed bilateral massive pulmonary embolism. Successful aspiration thrombectomy was performed followed by local alteplase infusion. At the end of the procedure, mPAP was reduced and blood pressure normalized allowing withdrawal of vasopressor support. Twenty-four-hour echocardiographic reassessment showed normal-sized cardiac chambers with preserved biventricular systolic function. Bedside echocardiography in patients with ST-segment elevation post-ROSC is instrumental in raising the suspicion of acute PE. In the absence of a culprit coronary lesion, prompt pulmonary angiography should be considered if immediately feasible. In these cases, CDT and aspiration in high-risk acute PE seem safe and effective in relieving obstructive shock and restoring hemodynamics.

18.
Pulm Circ ; 13(1): e12177, 2023 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-36618712

RESUMO

Pulmonary hypertension (PH) is a chronic disorder of the pulmonary circulation that often associates with other respiratory diseases (i.e., group III PH), leading to worsened symptoms and prognosis, notably when combined with interstitial lung diseases such as pulmonary fibrosis (PF). PH may lead to right ventricular (RV) failure, which accounts for a substantial part of the mortality in chronic lung disease patients. The disappointing results of pulmonary arterial hypertension (PAH)-related therapies in patients with PF emphasize the need to better understand the pathophysiologic mechanisms that drive PH development and progression in this specific setting. In this work, we validated an animal model of group III PH associated with PF (PH-PF), by using bleomycin (BM) intratracheal instillation and characterizing the nature of induced lung and vascular remodeling, including the influence on RV structure and function. To our knowledge, this is the first work describing this dose of BM in Sprague Dawley rats and the effects upon the heart and lungs, using different techniques such as echocardiography, heart catheterization, and histology. Our data shows the successful implementation of a rat model that mimics combined PF-PH, with most features seen in the equivalent human disease, such as lung and arterial remodeling, increased mPAP and RV dysfunction.

19.
J Pers Med ; 12(9)2022 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-36143301

RESUMO

(1) Background: access cavity preparation is the first stage of non-surgical endodontic treatment. The inaccuracy of this step may lead to numerous intraoperative complications, which impair the root canal treatment's prognosis and therefore the tooth's survival. Guided endodontics, meaning computer-aided static (SN) and dynamic navigation (DN) techniques, has recently emerged as a new approach for root canal location in complex cases. This review aims to compare SN and DN guided endodontics' techniques in non-surgical endodontic treatment. (2) Methods: an electronic search was performed on PubMed, Scopus, and Cochrane Library databases until October 2021. Studies were restricted by language (English, Spanish and Portuguese) and year of publication (from 2011 to 2021). (3) Results: a total of 449, 168 and 32 articles were identified in PubMed, Scopus, and Cochrane Library databases, respectively, after the initial search. Of the 649 articles, 134 duplicates were discarded. In this case, 67 articles were selected after title and abstract screening, of which 60 were assessed for eligibility through full-text analysis, with one article being excluded. Four cross-references were added. Thus, 63 studies were included. (4) Conclusions: guided endodontics procedures present minimally invasive and accurate techniques which allow for highly predictable root canal location, greater tooth structure preservation and lower risk of iatrogenic damage, mainly when performed by less experienced operators. Both SN and DN approaches exhibit different advantages and disadvantages that make them useful in distinct clinical scenarios.

20.
Polymers (Basel) ; 14(22)2022 Nov 17.
Artigo em Inglês | MEDLINE | ID: mdl-36433108

RESUMO

Electrochemically mediated atom transfer radical polymerization (eATRP) is developed in dispersion conditions to assist the preparation of cellulose-based films. Self-degassing conditions are achieved by the addition of sodium pyruvate (SP) as a ROS scavenger, while an aluminum counter electrode provides a simplified and more cost-effective electrochemical setup. Different polyacrylamides were grown on a model cellulose substrate which was previously esterified with 2-bromoisobutyrate (-BriB), serving as initiator groups. Small-scale polymerizations (15 mL) provided optimized conditions to pursue the scale-up up to 1000 mL (scale-up factor ~67). Cellulose-poly(N-isopropylacrylamide) was then chosen to prepare the tunable, thermoresponsive, solvent-free, and flexible films through a dissolution/regeneration method. The produced films were characterized by Fourier-transform infrared (FTIR), scanning electron microscopy (SEM), dynamic scanning calorimetry (DSC), and thermogravimetric analysis (TGA).

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