Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 99
Filtrar
Mais filtros

Intervalo de ano de publicação
1.
Am J Hum Genet ; 111(4): 701-713, 2024 Apr 04.
Artigo em Inglês | MEDLINE | ID: mdl-38531366

RESUMO

Copy-number variants (CNVs) play a substantial role in the molecular pathogenesis of hereditary disease and cancer, as well as in normal human interindividual variation. However, they are still rather difficult to identify in mainstream sequencing projects, especially involving exome sequencing, because they often occur in DNA regions that are not targeted for analysis. To overcome this problem, we developed OFF-PEAK, a user-friendly CNV detection tool that builds on a denoising approach and the use of "off-target" DNA reads, which are usually discarded by sequencing pipelines. We benchmarked OFF-PEAK on data from targeted sequencing of 96 cancer samples, as well as 130 exomes of individuals with inherited retinal disease from three different populations. For both sets of data, OFF-PEAK demonstrated excellent performance (>95% sensitivity and >80% specificity vs. experimental validation) in detecting CNVs from in silico data alone, indicating its immediate applicability to molecular diagnosis and genetic research.


Assuntos
Algoritmos , Neoplasias , Humanos , Sequenciamento de Nucleotídeos em Larga Escala , Análise de Sequência de DNA , Exoma , Variações do Número de Cópias de DNA/genética , Neoplasias/genética
2.
Biochem Biophys Res Commun ; 706: 149748, 2024 Apr 30.
Artigo em Inglês | MEDLINE | ID: mdl-38460450

RESUMO

Angiogenesis is a process that is controlled by a delicate combination of proangiogenic and antiangiogenic molecules and can be disrupted in various illnesses, including cancer. Non-cancerous diseases can also have an abnormal or insufficient vascular growth, inflammation and hypoxia, which exacerbate angiogenesis. These conditions include atherosclerosis, psoriasis, endometriosis, asthma, obesity and AIDS. Based on that, the present work assessed the in vitro and ex vivo antiangiogenic properties stemming from BthMP, a P-I metalloproteinase from Bothrops moojeni snake venom, via the VEGF pathway. BthMP at a concentration of 5 and 40 µg/mL showed no toxicity to endothelial cells (HUVEC) in the MTT assay and was not able to induce necrosis and colony proliferation. Interestingly, BthMP inhibited adhesion, migration and invasion of HUVECs in Matrigel and arrested in vitro angiogenesis by reducing the average number of nodules in toxin-treated cells by 9.6 and 17.32 at 5 and 40 µg/mL, respectively, and the number of tubules by 15.9 at 5 µg/mL and 21.6 at 40 µg/mL in a VEGF-dependent way, an essential proangiogenic property. Furthermore, BthMP inhibited the occurrence of the angiogenic process in an ex vivo aortic ring test by decreasing new vessel formation by 52% at 5 µg/mL and by 66% at 40 µg/mL and by increasing the expression of an antiangiogenic gene, SFLT-1, and decreasing the expression of the proangiogenic genes VEGFA and ANGPT-1. Finally, this toxin reduces the production of nitric oxide, a marker that promotes angiogenesis and VEGF modulation, and decreases the protein expression of VEGFA in the supernatant of the HUVEC culture by about 30 %. These results suggest that BthMP has a promising antiangiogenic property and proves to be a biotechnological mechanism for understanding the antiangiogenic responses induced by snake venom metalloproteinases, which could be applied to a variety of diseases that exhibit an imbalance of angiogenesis mechanisms.


Assuntos
Bothrops , Células Endoteliais , Serpentes Peçonhentas , Animais , Feminino , Humanos , Células Endoteliais/metabolismo , Fator A de Crescimento do Endotélio Vascular/metabolismo , Bothrops/metabolismo , Metaloproteases/metabolismo , Venenos de Serpentes , Células Endoteliais da Veia Umbilical Humana/metabolismo , Inibidores da Angiogênese/farmacologia
3.
Graefes Arch Clin Exp Ophthalmol ; 262(6): 1883-1897, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38189974

RESUMO

PURPOSE: Retinitis pigmentosa (RP) comprises a genetically and clinically heterogeneous group of inherited retinal degenerations, where 20-30% of patients exhibit extra-ocular manifestations (syndromic RP). Understanding the genetic profile of RP has important implications for disease prognosis and genetic counseling. This study aimed to characterize the genetic profile of syndromic RP in Portugal. METHODS: Multicenter, retrospective cohort study. Six Portuguese healthcare providers identified patients with a clinical diagnosis of syndromic RP and available genetic testing results. All patients had been previously subjected to a detailed ophthalmologic examination and clinically oriented genetic testing. Genetic variants were classified according to the American College of Medical Genetics and Genomics; only likely pathogenic or pathogenic variants were considered relevant for disease etiology. RESULTS: One hundred and twenty-two patients (53.3% males) from 100 families were included. Usher syndrome was the most frequent diagnosis (62.0%), followed by Bardet-Biedl (19.0%) and Senior-Løken syndromes (7.0%). Deleterious variants were identified in 86/100 families for a diagnostic yield of 86.0% (87.1% for Usher and 94.7% for Bardet-Biedl). A total of 81 genetic variants were identified in 25 different genes, 22 of which are novel. USH2A and MYO7A were responsible for most type II and type I Usher syndrome cases, respectively. BBS1 variants were the cause of Bardet-Biedl syndrome in 52.6% of families. Best-corrected visual acuity (BCVA) records were available at baseline and last visit for 99 patients (198 eyes), with a median follow-up of 62.0 months. The mean BCVA was 56.5 ETDRS letters at baseline (Snellen equivalent ~ 20/80), declining to 44.9 ETDRS letters (Snellen equivalent ~ 20/125) at the last available follow-up (p < 0.001). CONCLUSION: This is the first multicenter study depicting the genetic profile of syndromic RP in Portugal, thus contributing toward a better understanding of this heterogeneous disease group. Usher and Bardet-Biedl syndromes were found to be the most common types of syndromic RP in this large Portuguese cohort. A high diagnostic yield was obtained, highlighting current genetic testing capabilities in providing a molecular diagnosis to most affected individuals. This has major implications in determining disease-related prognosis and providing targeted genetic counseling for syndromic RP patients in Portugal.


Assuntos
Testes Genéticos , Mutação , Retinose Pigmentar , Humanos , Retinose Pigmentar/genética , Retinose Pigmentar/diagnóstico , Retinose Pigmentar/epidemiologia , Portugal/epidemiologia , Masculino , Feminino , Estudos Retrospectivos , Pessoa de Meia-Idade , Adulto , Adolescente , Adulto Jovem , Criança , Idoso , Linhagem , Síndromes de Usher/genética , Síndromes de Usher/diagnóstico , Síndromes de Usher/epidemiologia , Pré-Escolar , Análise Mutacional de DNA , Seguimentos , DNA/genética , Proteínas do Olho/genética
4.
Biomed Chromatogr ; : e5949, 2024 Jul 02.
Artigo em Inglês | MEDLINE | ID: mdl-38956820

RESUMO

α-Bisabolol (α-BIS) is a sesquiterpene alcohol present in chamomile essential oil [Chamomilla recutita (L.) Rauschert]. Despite its numerous pharmacological effects, its pharmacokinetics remain understudied. An analytical method capable of quantifying α-BIS in plasma is crucial to enable pharmacokinetic analysis. Presently, only one study has quantified it using mass spectrometry. Administering α-BIS requires a nanoemulsion for intravenous injection. This study aimed to develop and validate a bioanalytical method using high-performance liquid chromatography with an ultraviolet detector to quantify α-BIS in rat plasma. The method employed acetonitrile and ultrapure water (80:20, v/v) as the mobile phase, with a flow rate of 1 ml/min and concentrations ranging from 465 to 29.625 µg/ml. All US Food and Drug Administration-designated assays were successful, indicating the method's precision, accuracy, sensitivity and linearity in determining α-BIS in rat plasma. The developed nanoemulsion, assessed through dynamic light scattering analysis, the ensemble collection of particles and polydispersity index evaluation, proved safe and effective for intravenous administration. The pharmacokinetic parameters such as volume of distribution, clearance and half-life indicated that α-BIS tends to persist in the body. This study provides a foundation for further research to explore α-BIS's potential pharmaceutical applications in the future.

5.
J Clin Ultrasound ; 52(6): 680-686, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38587238

RESUMO

OBJECTIVE: To evaluate the association between Doppler patterns in fetuses with Down syndrome (DS) and their placental histopathologic findings. METHODS: A retrospective cross-sectional study was performed by collecting data from medical records of singleton pregnancies between January 2014 and January 2022, whose fetuses had a confirmed diagnosis of DS either prenatally or postnatally. Placental histopathology, maternal characteristics, and prenatal ultrasound (biometric parameters and umbilical artery [UA] Doppler) were evaluated. RESULTS: Of 69 eligible pregnant women, 61 met the inclusion and exclusion criteria. In the sample, 15 fetuses had an estimated fetal weight < 10th percentile for gestational age (GA) and were considered small for gestational age (SGA). Thirty-eight fetuses had increased resistance on the UA Doppler. Histologic changes were detected in 100% of the placentas, the most common being delayed villous maturation, alterations associated with poor fetal vascular perfusion, and villous dysmorphism. More than 50% of the placentas showed alterations related to placental insufficiency. We did not observe a statistically significant association between UA Doppler examination and placental alterations. All placentas analyzed in the SGA subgroup showed findings compatible with placental insufficiency. CONCLUSION: We found no statistically significant association between placental histopathologic findings and UA Doppler abnormalities in fetuses with DS. The placental alterations identified were delayed villous maturation, alterations associated with poor fetal vascular perfusion, and villous dysmorphism.


Assuntos
Síndrome de Down , Placenta , Ultrassonografia Pré-Natal , Humanos , Feminino , Síndrome de Down/diagnóstico por imagem , Síndrome de Down/complicações , Síndrome de Down/fisiopatologia , Gravidez , Estudos Transversais , Estudos Retrospectivos , Ultrassonografia Pré-Natal/métodos , Adulto , Placenta/diagnóstico por imagem , Placenta/patologia , Placenta/irrigação sanguínea , Hemodinâmica/fisiologia , Ultrassonografia Doppler/métodos , Artérias Umbilicais/diagnóstico por imagem , Artérias Umbilicais/fisiopatologia , Feto/diagnóstico por imagem
6.
Inflamm Res ; 72(3): 475-491, 2023 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-36617343

RESUMO

BACKGROUND: Cysteinyl leukotrienes (CysLT) are potent inflammation-promoting mediators, but remain scarcely explored in COVID-19. We evaluated urinary CysLT (U-CysLT) relationship with disease severity and their usefulness for prognostication in hospitalized COVID-19 patients. The impact on U-CysLT of veno-venous extracorporeal membrane oxygenation (VV-ECMO) and of comorbidities such as hypertension and obesity was also assessed. METHODS: Blood and spot urine were collected in "severe" (n = 26), "critically ill" (n = 17) and "critically ill on VV-ECMO" (n = 17) patients with COVID-19 at days 1-2 (admission), 3-4, 5-8 and weekly thereafter, and in controls (n = 23) at a single time point. U-CysLT were measured by ELISA. Routine markers, prognostic scores and outcomes were also evaluated. RESULTS: U-CysLT did not differ between groups at admission, but significantly increased along hospitalization only in critical groups, being markedly higher in VV-ECMO patients, especially in hypertensives. U-CysLT values during the first week were positively associated with ICU and total hospital length of stay in critical groups and showed acceptable area under curve (AUC) for prediction of 30-day mortality (AUC: 0.734, p = 0.001) among all patients. CONCLUSIONS: U-CysLT increase during hospitalization in critical COVID-19 patients, especially in hypertensives on VV-ECMO. U-CysLT association with severe outcomes suggests their usefulness for prognostication and as therapeutic targets.


Assuntos
COVID-19 , Humanos , COVID-19/terapia , Leucotrienos , Biomarcadores , Cisteína , Estudos Retrospectivos
7.
BMC Public Health ; 23(1): 1905, 2023 10 02.
Artigo em Inglês | MEDLINE | ID: mdl-37784133

RESUMO

BACKGROUND: Worsening environmental conditions may amplify people's emotional responses to an environmental crisis (eco-anxiety). In Portugal, young people seem to be especially concerned about climate change. However, this phenomenon needs to be interpreted using accurate instruments. Thus, this study aimed to validate the Portuguese version of the Hogg Eco-Anxiety Scale (HEAS) in young adults and examine the associations among eco-anxiety, sociodemographic characteristics, and pro-environmental behaviours. METHODS: A survey was administered to 623 Portuguese university students aged between 18 and 25 years. The survey included our Portuguese translation of the HEAS (obtained through a back-translation and pretesting process), a sociodemographic assessment, and questions related to pro-environmental behaviours. Confirmatory factor analysis was conducted to assess the construct validity of the Portuguese version of the HEAS, and global fit indices were used to assess whether the original four-dimensional structure of the scale was reproduced. The reliability of the Portuguese version of the HEAS was evaluated by Cronbach's alpha and the intraclass correlation coefficient. Measurement invariance examined sex differences in scale interpretation. Linear regressions were used to detect whether sociodemographic variables predict eco-anxiety and whether eco-anxiety predicts pro-environmental behaviours. RESULTS: The factorial structure of the original scale was replicated in the Portuguese version of the HEAS, showing good internal consistency, reliability over time and strict invariance between men and women. A higher paternal education level predicted greater eco-anxiety in children. Two dimensions of eco-anxiety-namely, rumination and anxiety about personal impacts on the environment-predicted higher engagement in pro-environmental behaviours. CONCLUSIONS: The translated scale is an appropriate tool to measure eco-anxiety in the Portuguese context and should be used to collect evidence to drive environmental and health policies. An individual's education level should be considered a determinant of their emotional response to environmental conditions. Importantly, eco-anxiety can act as a protective emotional response to preserving the planet.


Assuntos
Ansiedade , Traduções , Criança , Humanos , Masculino , Feminino , Adulto Jovem , Adolescente , Adulto , Portugal , Reprodutibilidade dos Testes , Ansiedade/epidemiologia , Inquéritos e Questionários , Psicometria/métodos
8.
Mem Inst Oswaldo Cruz ; 118: e220225, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-38018570

RESUMO

BACKGROUND: Leishmaniasis, a neglected disease caused by the parasite Leishmania, is treated with drugs associated with high toxicity and limited efficacy, in addition to constant reports of the emergence of resistant parasites. In this context, snake serums emerge as good candidates since they are natural sources with the potential to yield novel drugs. OBJECTIVES: We aimed to show the antileishmanial effects of γCdcPLI, a phospholipase A2 inhibitor from Crotalus durissus collilineatus snake serum, against Leishmania (Leishmania) amazonensis. METHODS: Promastigotes forms were exposed to γCdcPLI, and we assessed the parasite viability and cell cycle, as well as invasion and proliferation assays. FINDINGS: Despite the low cytotoxicity effect on macrophages, our data indicate that γCdcPLI has a direct effect on parasites promoting an arrest in the G1 phase and reduction in the G2/M phase at the highest dose tested. Moreover, this PLA2 inhibitor reduced the parasite infectivity when promastigotes were pre-treated. Also, we demonstrated that the γCdcPLI treatment modulated the host cell environment impairing early and late steps of the parasitism. MAIN CONCLUSIONS: γCdcPLI is an interesting tool for the discovery of new essential targets on the parasite, as well as an alternative compound to improve the effectiveness of the leishmaniasis treatment.


Assuntos
Antiprotozoários , Leishmania , Leishmaniose , Animais , Humanos , Camundongos , Crotalus , Leishmaniose/tratamento farmacológico , Antiprotozoários/farmacologia , Antiprotozoários/uso terapêutico , Camundongos Endogâmicos BALB C
9.
Liver Int ; 42(8): 1879-1890, 2022 08.
Artigo em Inglês | MEDLINE | ID: mdl-35304813

RESUMO

BACKGROUND & AIM: Liver transplantation (LT) selection models for hepatocellular carcinoma (HCC) have not been proposed to predict waitlist dropout because of tumour progression. The aim of this study was to compare the alpha-foetoprotein (AFP) model and other pre-LT models in their prediction of HCC dropout. METHODS: A multicentre cohort study was conducted in 20 Latin American transplant centres, including 994 listed patients for LT with HCC from 2012 to 2018. Longitudinal tumour characteristics, and patterns of progression were recorded at time of listing, after treatments and at last follow-up over the waitlist period. Competing risk regression models were performed, and model's discrimination was compared estimating Harrell's adapted c-statistics. RESULTS: HCC dropout rate was significantly higher in patients beyond (24% [95% CI 16-28]) compared to those within Milan criteria (8% [95% IC 5%-12%]; p < .0001), with a SHR of 3.01 [95% CI 2.03-4.47]), adjusted for waiting list time and bridging therapies (c-index 0.63 [95% CI 0.57; 0.69). HCC dropout rates were higher in patients with AFP scores >2 (adjusted SHR of 3.17 [CI 2.13-4.71]), c-index of 0.71 (95% CI 0.65-0.77; p = .09 vs Milan). Similar discrimination power for HCC dropout was observed between the AFP score and the Metroticket 2.0 model. In patients within Milan, an AFP score >2 points discriminated two populations with a higher risk of HCC dropout (SHR 1.68 [95% CI 1.08-2.61]). CONCLUSIONS: Pre-transplant selection models similarly predicted HCC dropout. However, the AFP model can discriminate a higher risk of dropout among patients within Milan criteria.


Assuntos
Carcinoma Hepatocelular , Neoplasias Hepáticas , Carcinoma Hepatocelular/diagnóstico , Carcinoma Hepatocelular/patologia , Carcinoma Hepatocelular/cirurgia , Estudos de Coortes , Indicadores Básicos de Saúde , Humanos , Neoplasias Hepáticas/diagnóstico , Neoplasias Hepáticas/patologia , Neoplasias Hepáticas/cirurgia , Transplante de Fígado , Pacientes Desistentes do Tratamento , Seleção de Pacientes , Estudos Retrospectivos , Listas de Espera , alfa-Fetoproteínas
10.
PLoS Genet ; 15(8): e1008315, 2019 08.
Artigo em Inglês | MEDLINE | ID: mdl-31425546

RESUMO

Cilia are evolutionarily conserved hair-like structures with a wide spectrum of key biological roles, and their dysfunction has been linked to a growing class of genetic disorders, known collectively as ciliopathies. Many strides have been made towards deciphering the molecular causes for these diseases, which have in turn expanded the understanding of cilia and their functional roles. One recently-identified ciliary gene is ARL2BP, encoding the ADP-Ribosylation Factor Like 2 Binding Protein. In this study, we have identified multiple ciliopathy phenotypes associated with mutations in ARL2BP in human patients and in a mouse knockout model. Our research demonstrates that spermiogenesis is impaired, resulting in abnormally shaped heads, shortened and mis-assembled sperm tails, as well as in loss of axonemal doublets. Additional phenotypes in the mouse included enlarged ventricles of the brain and situs inversus. Mouse embryonic fibroblasts derived from knockout animals revealed delayed depolymerization of primary cilia. Our results suggest that ARL2BP is required for the structural maintenance of cilia as well as of the sperm flagellum, and that its deficiency leads to syndromic ciliopathy.


Assuntos
Proteínas de Transporte/genética , Ciliopatias/genética , Infertilidade Masculina/genética , Proteínas de Membrana Transportadoras/genética , Fotofobia/genética , Adulto , Animais , Cílios/patologia , Ciliopatias/patologia , Modelos Animais de Doenças , Feminino , Humanos , Infertilidade Masculina/patologia , Masculino , Camundongos , Camundongos Knockout , Microtúbulos/metabolismo , Pessoa de Meia-Idade , Linhagem , Fotofobia/patologia , Motilidade dos Espermatozoides/genética , Cauda do Espermatozoide/patologia , Espermatogênese/genética , Síndrome , Fatores de Transcrição
11.
Transfus Med Hemother ; 49(4): 250-257, 2022 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-36159955

RESUMO

Introduction: Leukostasis refers to clinical symptoms caused by hyperleukocytosis seen in some haematological diseases such as leukaemia. Cytoreduction can be achieved by therapeutic leukapheresis. The aim of this study was to retrospectively analyse the procedures performed in our Centre and to evaluate their efficacy and safety. Methods: This was a retrospective study of all the therapeutic leukapheresis procedures carried out in our Centre between January 1998 and December 2020. The sample collection was obtained through the review of the clinical files of the respective patients. Statistical analysis was performed using the software R v.4.0.1. A total of 54 therapeutic leukapheresis procedures were performed in 31 patients in our Centre. Results: After these procedures clinical improvement was observed in 16 patients and we verify that there was a significant difference in survival between the group that improved and the group that maintained the same clinical condition or worsened. The lack of immediate clinical improvement was a sign of a poor prognosis. Laboratory efficacy occurred in 16 patients who had a reduction in white blood cell count, with a 39.1% reduction after 24 h, and did not succeed in 15 patients, who had no reduction. However, in this case there is no significant difference in survival between the two groups. There was some complication in 53.9% of the procedures, with hypocalcaemia being the most frequent, which was observed in 22 procedures. Only 4 patients experienced serious side effects but these adverse reactions cannot be attributed to the procedures carried out. The overall survival rate 6 months after this treatment was 51.6%. Conclusion: Despite the reduced number of patients, we conclude that therapeutic leukapheresis is a safe and effective option that may still have a therapeutic role in some cases.

12.
Hum Mutat ; 42(3): 261-271, 2021 03.
Artigo em Inglês | MEDLINE | ID: mdl-33300174

RESUMO

In murine and canine animal models, mutations in the Arylsulfatase G gene (ARSG) cause a particular lysosomal storage disorder characterized by neurological phenotypes. Recently, two variants in the same gene were found to be associated with an atypical form of Usher syndrome in humans, leading to visual and auditory impairment without the involvement of the central nervous system. In this study, we identified three novel pathogenic variants in ARSG, which segregated recessively with the disease in two families from Portugal. The probands were affected with retinitis pigmentosa and sensorineural hearing loss, generally with an onset of symptoms in their fourth decade of life. Functional experiments showed that these pathogenic variants abolish the sulfatase activity of the Arylsulfatase G enzyme and impede the appropriate lysosomal localization of the protein product, which appears to be retained in the endoplasmic reticulum. Our data enable to definitely confirm that different biallelic variants in ARSG cause a specific deaf-blindness syndrome, by abolishing the activity of the enzyme it encodes.


Assuntos
Arilsulfatases , Retinose Pigmentar , Síndromes de Usher , Arilsulfatases/genética , Arilsulfatases/metabolismo , Humanos , Mutação , Linhagem , Fenótipo , Portugal , Retinose Pigmentar/genética , Síndromes de Usher/genética , Síndromes de Usher/metabolismo
13.
Appl Environ Microbiol ; 87(24): e0138021, 2021 11 24.
Artigo em Inglês | MEDLINE | ID: mdl-34586912

RESUMO

The production of specialized metabolites by Streptomyces bacteria is usually temporally regulated. This regulation is complex and frequently involves both global and pathway-specific mechanisms. Streptomyces ambofaciens ATCC23877 produces several specialized metabolites, including spiramycins, stambomycins, kinamycins and congocidine. The production of the first three molecules has been shown to be controlled by one or several cluster-situated transcriptional regulators. However, nothing is known regarding the regulation of congocidine biosynthesis. Congocidine (netropsin) belongs to the family of pyrrolamide metabolites, which also includes distamycin and anthelvencins. Most pyrrolamides bind into the minor groove of DNA, specifically in A/T-rich regions, which gives them numerous biological activities, such as antimicrobial and antitumoral activities. We previously reported the characterization of the pyrrolamide biosynthetic gene clusters of congocidine (cgc) in S. ambofaciens ATCC23877, distamycin (dst) in Streptomyces netropsis DSM40846, and anthelvencins (ant) in Streptomyces venezuelae ATCC14583. The three gene clusters contain a gene encoding a putative transcriptional regulator, cgc1, dst1, and ant1, respectively. Cgc1, Dst1, and Ant1 present a high percentage of amino acid sequence similarity. We demonstrate here that Cgc1, an atypical orphan response regulator, activates the transcription of all cgc genes in the stationary phase of S. ambofaciens growth. We also show that the cgc cluster is constituted of eight main transcriptional units. Finally, we show that congocidine induces the expression of the transcriptional regulator Cgc1 and of the operon containing the resistance genes (cgc20 and cgc21, coding for an ABC transporter), and propose a model for the transcriptional regulation of the cgc gene cluster. IMPORTANCE Understanding the mechanisms of regulation of specialized metabolite production can have important implications both at the level of specialized metabolism study (expression of silent gene clusters) and at the biotechnological level (increase of the production of a metabolite of interest). We report here a study on the regulation of the biosynthesis of a metabolite from the pyrrolamide family, congocidine. We show that congocidine biosynthesis and resistance are controlled by Cgc1, a cluster-situated regulator. As the gene clusters directing the biosynthesis of the pyrrolamides distamycin and anthelvencin encode a homolog of Cgc1, our findings may be relevant for the biosynthesis of other pyrrolamides. In addition, our results reveal a new type of feed-forward induction mechanism, in which congocidine induces its own biosynthesis through the induction of the transcription of cgc1.


Assuntos
Regulação Bacteriana da Expressão Gênica , Netropsina , Streptomyces , Distamicinas , Genes Bacterianos , Família Multigênica , Netropsina/biossíntese , Streptomyces/genética , Streptomyces/metabolismo
14.
Transpl Int ; 34(1): 97-109, 2021 01.
Artigo em Inglês | MEDLINE | ID: mdl-33040420

RESUMO

This study aimed to compare liver transplantation (LT) outcomes and evaluate the potential rise in numbers of LT candidates with hepatocellular carcinoma (HCC) of different allocation policies in a high waitlist mortality region. Three policies were applied in two Latin American cohorts (1085 HCC transplanted patients and 917 listed patients for HCC): (i) Milan criteria with expansion according to UCSF downstaging (UCSF-DS), (ii) the AFP score, and (iii) restrictive policy or Double Eligibility Criteria (DEC; within Milan + AFP score ≤2). Increase in HCC patient numbers was evaluated in an Argentinian prospective validation set (INCUCAI; NCT03775863). Expansion criteria in policy A showed that UCSF-DS [28.4% (CI 12.8-56.2)] or "all-comers" [32.9% (CI 11.9-71.3)] had higher 5-year recurrence rates compared to Milan, with 10.9% increase in HCC patients for LT. The policy B showed lower recurrence rates for AFP scores ≤2 points, even expanding beyond Milan criteria, with a 3.3% increase. Patients within DEC had lower 5-year recurrence rates compared with those beyond DEC [13.3% (CI 10.1-17.3) vs 24.2% (CI 17.4-33.1; P = 0.0006], without significant HCC expansion. In conclusion, although the application of a stricter policy may optimize the selection process, this restrictive policy may lead to ethical concerns in organ allocation (NCT03775863).


Assuntos
Carcinoma Hepatocelular , Neoplasias Hepáticas , Transplante de Fígado , Carcinoma Hepatocelular/cirurgia , Estudos de Coortes , Humanos , Neoplasias Hepáticas/cirurgia , Recidiva Local de Neoplasia , Seleção de Pacientes , Estudos Prospectivos , Estudos Retrospectivos
15.
Clin Gastroenterol Hepatol ; 18(11): 2554-2563.e3, 2020 10.
Artigo em Inglês | MEDLINE | ID: mdl-32113892

RESUMO

BACKGROUND & AIMS: Little is known about how a sustained virologic response (SVR) to treatment of hepatitis C virus infection with direct-acting antivirals (DAAs) affects patient mortality and development of new liver-related events. We aimed to evaluate the incidence of disease progression in patients treated with DAAs. METHODS: We performed a prospective multicenter cohort study of 1760 patients who received DAA treatment at 23 hospitals in Latin America, from May 1, 2016, through November 21, 2019. We excluded patients with a history of liver decompensation, hepatocellular carcinoma (HCC), or solid-organ transplantation. Disease progression after initiation of DAA therapy included any of the following new events: liver decompensation, HCC, liver transplantation, or death. Evaluation of variables associated with the primary outcome was conducted using a time-dependent Cox proportional hazards models. RESULTS: During a median follow-up period of 26.2 months (interquartile range, 15.3-37.5 mo), the overall cumulative incidence of disease progression was 4.1% (95% CI, 3.2%-5.1%), and after SVR assessment was 3.6% (95% CI, 2.7%-4.7%). Baseline variables associated with disease progression were advanced liver fibrosis (hazard ratio [HR], 3.4; 95% CI, 1.2-9.6), clinically significant portal hypertension (HR, 2.1; 95% CI, 1.2-3.8), and level of albumin less than 3.5 mg/dL (HR, 4.1; 95% CI, 2.3-7.6), adjusted for SVR achievement as a time covariable. Attaining an SVR reduced the risk of liver decompensation (HR, 0.3; 95% CI, 0.1-0.8; P = .016) and de novo HCC (HR, 0.2; 95% CI, 0.1%-0.8%; P = .02) in the overall cohort. CONCLUSIONS: Treatment of hepatitis C virus infection with DAAs significantly reduces the risk of new liver-related complications and should be offered to all patients, regardless of disease stage. Clinicaltrials.gov: NCT03775798.


Assuntos
Carcinoma Hepatocelular , Hepatite C Crônica , Neoplasias Hepáticas , Antivirais/uso terapêutico , Carcinoma Hepatocelular/tratamento farmacológico , Carcinoma Hepatocelular/epidemiologia , Estudos de Coortes , Progressão da Doença , Hepacivirus , Hepatite C Crônica/complicações , Hepatite C Crônica/tratamento farmacológico , Humanos , Cirrose Hepática/tratamento farmacológico , Cirrose Hepática/epidemiologia , Neoplasias Hepáticas/tratamento farmacológico , Neoplasias Hepáticas/epidemiologia , Estudos Prospectivos , Fatores de Risco , Resposta Viral Sustentada
16.
Liver Transpl ; 26(5): 640-650, 2020 05.
Artigo em Inglês | MEDLINE | ID: mdl-32133773

RESUMO

The association between direct-acting antivirals (DAAs) and hepatocellular carcinoma (HCC) wait-list progression or its recurrence following liver transplantation (LT) remains uncertain. We evaluated the impact of DAAs on HCC wait-list progression and post-LT recurrence. This Latin American multicenter retrospective cohort study included HCC patients listed for LT between 2012 and 2018. Patients were grouped according to etiology of liver disease: hepatitis C virus (HCV) negative, HCV+ never treated with DAAs, and HCV+ treated with DAAs either before or after transplantation. Multivariate competing risks models were conducted for both HCC wait-list progression adjusted by a propensity score matching (pre-LT DAA effect) and for post-LT HCC recurrence (pre- or post-LT DAA effect). From 994 included patients, 50.6% were HCV-, 32.9% were HCV+ never treated with DAAs, and 16.5% were HCV+ treated with DAAs either before (n = 66) or after LT (n = 98). Patients treated with DAAs before LT presented similar cumulative incidence of wait-list tumor progression when compared with those patients who were HCV+ without DAAs (26.2% versus 26.9%; P = 0.47) and a similar HCC-related dropout rate (12.1% [95% CI, 0.4%-8.1%] versus 12.9% [95% CI, 3.8%-27.2%]), adjusted for baseline tumor burden, alpha-fetoprotein values, HCC diagnosis after listing, bridging therapies, and by the probability of having received or not received DAAs through propensity score matching (subhazard ratio [SHR], 0.9; 95% CI, 0.6-1.6; P = 0.95). A lower incidence of posttransplant HCC recurrence among HCV+ patients who were treated with pre- or post-LT DAAs was observed (SHR, 0.7%; 95% CI, 0.2%-4.0%). However, this effect was confounded by the time to DAA initiation after LT. In conclusion, in this multicenter cohort, HCV treatment with DAAs did not appear to be associated with an increased wait-list tumor progression and HCC recurrence after LT.


Assuntos
Carcinoma Hepatocelular , Hepatite C Crônica , Neoplasias Hepáticas , Transplante de Fígado , Antivirais/uso terapêutico , Carcinoma Hepatocelular/tratamento farmacológico , Carcinoma Hepatocelular/epidemiologia , Carcinoma Hepatocelular/cirurgia , Hepatite C Crônica/complicações , Hepatite C Crônica/tratamento farmacológico , Hepatite C Crônica/epidemiologia , Humanos , Neoplasias Hepáticas/tratamento farmacológico , Neoplasias Hepáticas/epidemiologia , Neoplasias Hepáticas/cirurgia , Transplante de Fígado/efeitos adversos , Recidiva Local de Neoplasia/tratamento farmacológico , Recidiva Local de Neoplasia/epidemiologia , Estudos Retrospectivos
17.
J Med Virol ; 92(12): 3545-3555, 2020 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-32749710

RESUMO

INTRODUCTION: Although the effectiveness of direct-acting antivirals (DAAs) for the treatment of chronic hepatitis C virus (HCV) has been reported in real-world settings, predictive factors of treatment failure are lacking. Therefore, we sought to explore the baseline predictors of treatment response to DAAs. METHODS: This was a prospective multicenter cohort study from the Latin American Liver Research Educational and Awareness Network (LALREAN) including patients who received DAA treatment from May 2016 to April 2019. A multivariate logistic regression model was conducted to identify variables associated with unachieved sustained virological response (SVR), defined as treatment failure (odds ratios [OR] and 95% confidence intervals [CIs]). RESULTS: From 2167 patients (55.2% with cirrhosis) who initiated DAA therapy, 89.4% completed a full-course treatment (n = 1938). Median treatment duration was 12 weeks, and 50% received ribavirin. Definitive suspension due to intolerance or other causes was observed in only 1.0% cases (n = 20). Overall non-SVR12 was 4.5% (95% CI, 3.5-5.7). There were no significant differences in treatment failure according to HCV genotypes and the degree of fibrosis. Independently associated variables with DAA failure were liver function impairment according to the Child-Pugh score B OR, 2.09 (P = .06), Child-Pugh C OR, 11.7 (P < .0001); and liver transplant (LT) recipient OR, 3.75 (P = .01). CONCLUSION: In this real-life setting, higher DAA treatment failure rates were observed in patients with decompensated cirrhosis and in LT recipients. These predictive baseline factors should be addressed to individualize the appropriate time-point of DAA treatment (NCT03775798; www. CLINICALTRIALS: gov).

18.
Pharmacol Res ; 162: 105280, 2020 12.
Artigo em Inglês | MEDLINE | ID: mdl-33161139

RESUMO

Neuropathic pain (NP) is a chronic condition that results from a lesion or disease of the nervous system, greatly impacting patients' quality of life. Current pharmacotherapy options deliver inadequate and/or insufficient responses and thus a significant unmet clinical need remains for alternative treatments in NP. Neuroinflammation, oxidative stress and their reciprocal relationship are critically involved in NP pathophysiology. In this context, new pharmacological approaches, aiming at enhancing the resolution phase of inflammation and/or restoring redox balance by targeting specific reactive oxygen species (ROS) sources, are emerging as potential therapeutic strategies for NP, with improved efficacy and safety profiles. Several reports have demonstrated that administration of exogenous specialized pro-resolving mediators (SPMs) ameliorates NP pathophysiology. Likewise, deletion or inhibition of the ROS-generating enzyme NADPH oxidase (NOX), particularly its isoforms 2 and 4, results in beneficial effects in NP models. Notably, SPMs also modulate oxidative stress and NOX also regulates neuroinflammation. By targeting neuroinflammatory and oxidative pathways, both SPMs analogues and isoform-specific NOX inhibitors are promising therapeutic strategies for NP.


Assuntos
Anti-Inflamatórios/uso terapêutico , NADPH Oxidases/antagonistas & inibidores , Neuralgia/tratamento farmacológico , Estresse Oxidativo/efeitos dos fármacos , Fatores Etários , Animais , Humanos , Inflamação/tratamento farmacológico , Caracteres Sexuais
19.
Nitric Oxide ; 82: 1-11, 2019 01 01.
Artigo em Inglês | MEDLINE | ID: mdl-30423454

RESUMO

We evaluated whether l-proline (Pro) supplementation improves redox status and nitric oxide (NO) bioavailability and prevents or delays angiotensin II (AngII)-induced hypertension. Male Sprague-Dawley rats were distributed to four experimental groups: Pro + AngII (Pro-Ang), Pro + Saline (Pro-Sal), Vehicle + AngII (Veh-Ang) and Veh + Saline (Veh-Sal). Pro solution (2 g.kg-1·day-1) or water (vehicle) were orally administered, from day 0 to day 21. AngII (200 ng.kg-1.min-1) or saline were infused (s.c.) from day 7 to day 21. Systolic blood pressure (SBP) was measured by the tail-cuff method. From day 20-21, animals were kept on metabolic cages for 24h-urine collection. On day 21, urine and blood were collected for further quantification of redox status biomarkers, NO-related markers (urinary nitrates and nitrites, U-NOx; plasma asymmetric dimethylarginine, P-ADMA), metabolic and renal parameters. Pro prevented the AngII-induced SBP rise [mean (95% CI), Day 19: Pro-AngII, 137 (131; 143) vs. Veh-AngII, 157 (151; 163) mm Hg, P < 0.001]. Pro-AngII rats also had increased values of U-NOx, systemic and urinary total antioxidant status (TAS), urinary H2O2 and plasma urea, as well as reduced P-ADMA and unaltered urinary isoprostanes. Plasma Pro was inversely correlated with P-ADMA (r = -0.52, p = 0.0009) and positively correlated with urinary TAS (r = 0.55, p = 0.0005) which, in turn, was inversely correlated with P-ADMA (r = -0.56, p = 0.0004). Furthermore, urinary H2O2 values decreased across P-ADMA tertiles (p for linear trend = 0.023). These results suggest that Pro reduces P-ADMA levels and improves redox status, thereby increasing NO bioavailability and counteracting the AngII-induced SBP rise. H2O2 and TAS modulation by Pro may contribute to the reduced P-ADMA concentration.


Assuntos
Angiotensina II/farmacologia , Pressão Sanguínea/efeitos dos fármacos , Suplementos Nutricionais , Óxido Nítrico/metabolismo , Prolina/farmacologia , Animais , Disponibilidade Biológica , Hipertensão/induzido quimicamente , Hipertensão/tratamento farmacológico , Masculino , Prolina/administração & dosagem , Ratos , Ratos Sprague-Dawley
20.
Liver Int ; 39(6): 1033-1043, 2019 06.
Artigo em Inglês | MEDLINE | ID: mdl-30636361

RESUMO

BACKGROUND & AIMS: Data from Europe and North America have been published regarding the risk of developing hepatocellular carcinoma (HCC) after treatment with direct antiviral agents (DAA). We proposed to evaluate cumulative incidence and associated risk factors for de novo HCC. METHODS: This was a prospective multicentre cohort study from Latin America including 1400 F1-F4-treated patients with DAAs (F3-F4 n = 1017). Cox proportional regression models (hazard ratios, HR and 95% CI) were used to evaluate independent associated variables with HCC. Further adjustment with competing risk regression and propensity score matching was carried out. RESULTS: During a median follow-up of 16 months (IQR 8.9-23.4 months) since DAAs initiation, overall cumulative incidence of HCC was 0.02 (CI 0.01; 0.03) at 12 months and 0.04 (CI 0.03; 0.06) at 24 months. Cumulative incidence of HCC in cirrhotic patients (n = 784) was 0.03 (CI 0.02-0.05) at 12 months and 0.06 (CI 0.04-0.08) at 24 months of follow-up. Failure to achieve SVR was independently associated with de novo HCC with a HR of 4.9 (CI 1.44; 17.32), after adjusting for diabetes mellitus, previous interferon non-responder, Child-Pugh and clinically significant portal hypertension. SVR presented an overall relative risk reduction for de novo HCC of 73% (CI 15%-91%), 17 patients were needed to be treated to prevent one case of de novo HCC in this cohort. CONCLUSIONS: Achieving SVR with DAA regimens was associated with a significant risk reduction in HCC. However, this risk remained high in patients with advanced fibrosis, thus demanding continuous surveillance strategies in this population.


Assuntos
Antivirais/uso terapêutico , Carcinoma Hepatocelular/epidemiologia , Hepatite C Crônica/tratamento farmacológico , Cirrose Hepática/complicações , Neoplasias Hepáticas/epidemiologia , Idoso , Carcinoma Hepatocelular/virologia , Feminino , Hepacivirus/efeitos dos fármacos , Hepatite C Crônica/complicações , Humanos , Incidência , América Latina/epidemiologia , Cirrose Hepática/virologia , Neoplasias Hepáticas/virologia , Masculino , Pessoa de Meia-Idade , Pontuação de Propensão , Modelos de Riscos Proporcionais , Estudos Prospectivos , Fatores de Risco , Resposta Viral Sustentada
SELEÇÃO DE REFERÊNCIAS
Detalhe da pesquisa