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1.
Nucleic Acids Res ; 52(2): 660-676, 2024 Jan 25.
Artigo em Inglês | MEDLINE | ID: mdl-38038269

RESUMO

Various origin mapping approaches have enabled genome-wide identification of origins of replication (ORI) in model organisms, but only a few studies have focused on divergent organisms. By employing three complementary approaches we provide a high-resolution map of ORIs in Plasmodium falciparum, the deadliest human malaria parasite. We profiled the distribution of origin of recognition complex (ORC) binding sites by ChIP-seq of two PfORC subunits and mapped active ORIs using NFS and SNS-seq. We show that ORIs lack sequence specificity but are not randomly distributed, and group in clusters. Licensing is biased towards regions of higher GC content and associated with G-quadruplex forming sequences (G4FS). While strong transcription likely enhances firing, active origins are depleted from transcription start sites. Instead, most accumulate in transcriptionally active gene bodies. Single molecule analysis of nanopore reads containing multiple initiation events, which could have only come from individual nuclei, showed a relationship between the replication fork pace and the distance to the nearest origin. While some similarities were drawn with the canonic eukaryote model, the distribution of ORIs in P. falciparum is likely shaped by unique genomic features such as extreme AT-richness-a product of evolutionary pressure imposed by the parasitic lifestyle.


Assuntos
Plasmodium falciparum , Origem de Replicação , Humanos , Sítios de Ligação , Mapeamento Cromossômico , Replicação do DNA , Genômica , Plasmodium falciparum/genética , Origem de Replicação/genética , Transcrição Gênica
3.
Cell Host Microbe ; 31(9): 1539-1551.e6, 2023 09 13.
Artigo em Inglês | MEDLINE | ID: mdl-37708854

RESUMO

Malaria remains one of the most devastating infectious diseases. Reverse genetic screens offer a powerful approach to identify genes and molecular processes governing malaria parasite biology. However, the complex regulation of gene expression and genotype-phenotype associations in the mosquito vector, along with sexual reproduction, have hindered the development of screens in this critical part of the parasite life cycle. To address this, we developed a genetic approach in the rodent parasite Plasmodium berghei that, in combination with barcode sequencing, circumvents the fertilization roadblock and enables screening for gametocyte-expressed genes required for parasite infection of the mosquito Anopheles coluzzii. Our results confirm previous findings, validating our approach for scaling up, and identify genes necessary for mosquito midgut infection, oocyst development, and salivary gland infection. These findings can aid efforts to study malaria transmission biology and to develop interventions for controlling disease transmission.


Assuntos
Anopheles , Esporozoítos , Animais , Esporozoítos/genética , Mosquitos Vetores/genética , Plasmodium berghei/genética , Anopheles/genética
4.
Rev Port Cardiol ; 42(2): 113-120, 2023 02.
Artigo em Inglês, Português | MEDLINE | ID: mdl-36163139

RESUMO

INTRODUCTION AND OBJECTIVES: Cardiogenic shock (CS) complicates 5-10% of cases of myocardial infarction (MI). Whether glycoprotein IIb/IIIa inhibitors (GPIs) are beneficial in these patients is controversial. Our aim is to assess the prognostic impact of GPI use on in-hospital mortality and outcomes in patients with MI and CS undergoing percutaneous coronary intervention (PCI). METHODS: Between October 2010 and December 2019, 27578 acute coronary syndrome (ACS) patients were included in the multicenter Portuguese Registry of Acute Coronary Syndromes. Of these, 357 with an MI complicated by CS were included in the analysis and grouped based on whether they received GPI therapy (with GPI, n=107 and without GPI, n=250). The primary endpoint was in-hospital mortality. Secondary endpoints included successful PCI and in-hospital reinfarction and major bleeding. RESULTS: Demographics and cardiovascular risk factors did not differ between groups. ST-elevation MI patients were more likely to receive GPIs (95% vs. 83%, p=0.002). In-hospital mortality was similar between groups (OR 1.80, 95% CI 0.96-3.37). Only age and the use of inotropes or intra-aortic balloon pump were predictors of mortality. Also, no differences between groups were noted for successful PCI (OR 0.33, 95% CI 0.62-4.06), reinfarction (OR 0.77, 95% CI 0.15-3.90), or major bleeding (OR 1.68, 95% CI 0.75-3.74). CONCLUSION: The use of GPIs in the context of MI with CS did not significantly impact in-hospital outcomes.


Assuntos
Síndrome Coronariana Aguda , Infarto do Miocárdio , Intervenção Coronária Percutânea , Humanos , Síndrome Coronariana Aguda/etiologia , Choque Cardiogênico/etiologia , Choque Cardiogênico/terapia , Intervenção Coronária Percutânea/efeitos adversos , Portugal , Infarto do Miocárdio/complicações , Hemorragia/etiologia , Sistema de Registros , Glicoproteínas , Resultado do Tratamento , Inibidores da Agregação Plaquetária/efeitos adversos
5.
PLoS Negl Trop Dis ; 16(12): e0010935, 2022 12.
Artigo em Inglês | MEDLINE | ID: mdl-36512510

RESUMO

Aedes mosquito vectors transmit many viruses of global health concern, including dengue, chikungunya and Zika. These vector-borne viral diseases have a limited number of treatment options, and vaccines vary in their effectiveness. Consequently, integrated vector management is a primary strategy for disease control. However, the increasing emergence and spread of insecticide resistance is threatening the efficacy of vector control methods. Identifying mutations associated with resistance in vector populations is important to monitor the occurrence and evolution of insecticide resistance and inform control strategies. Rapid and cost-effective genome sequencing approaches are urgently needed. Here we present an adaptable targeted amplicon approach for cost-effective implementation within next generation sequencing platforms. This approach can identify single nucleotide polymorphisms (SNPs) and small insertions and deletions (indels) in genes involved in insecticide resistance in Aedes aegypti mosquitoes. We designed and tested eleven amplicons, which included segments of the ace-1 (carbamate target), the Voltage-Gated Sodium Channel (vgsc; pyrethroids, DDT and organochlorines), and rdl (dieldrin) genes; thereby covering established knockdown resistance (kdr) mutations (e.g., S989P, I1011M/V, V1016G/I and F1534C), with the potential to identify novel ones. The amplicon assays were designed with internal barcodes, to facilitate multiplexing of large numbers of mosquitoes at low cost, and were sequenced using an Illumina platform. Our approach was evaluated on 152 Ae. aegypti mosquitoes collected in Cabo Verde, an archipelago with a history of arbovirus outbreaks. The amplicon sequence data revealed 146 SNPs, including four non-synonymous polymorphisms in the vgsc gene, one in ace-1 and the 296S rdl mutation previously associated with resistance to organochlorines. The 296S rdl mutation was identified in 98% of mosquitoes screened, consistent with the past use of an organochlorine compound (e.g., DDT). Overall, our work shows that targeted amplicon sequencing is a rapid, robust, and cost-effective tool that can be used to perform high throughput monitoring of insecticide resistance.


Assuntos
Aedes , Inseticidas , Piretrinas , Canais de Sódio Disparados por Voltagem , Infecção por Zika virus , Zika virus , Animais , Resistência a Inseticidas/genética , Aedes/genética , DDT , Cabo Verde , Inseticidas/farmacologia , Piretrinas/farmacologia , Mosquitos Vetores/genética , Canais de Sódio Disparados por Voltagem/genética , Mutação
6.
Sci Rep ; 12(1): 11719, 2022 07 09.
Artigo em Inglês | MEDLINE | ID: mdl-35810191

RESUMO

In November 2015, cases of Zika virus infection were recorded in Cabo Verde (Africa), originating from Brazil. The outbreak subsided after seven months with 7580 suspected cases. We performed a serological survey (n = 431) in Praia, the capital city, 3 months after transmission ceased. Serum samples were screened for arbovirus antibodies using ELISA techniques and revealed seroconverted individuals with Zika (10.9%), dengue (1-4) (12.5%), yellow fever (0.2%) and chikungunya (2.6%) infections. Zika seropositivity was predominantly observed amongst females (70%). Using a logistic model, risk factors for increased odds of Zika seropositivity included age, self-reported Zika infection, and dengue seropositivity. Serological data from Zika and dengue virus assays were strongly correlated (Spearman's rs = 0.80), which reduced when using a double antigen binding ELISA (Spearman's rs = 0.54). Overall, our work improves an understanding of how Zika and other arboviruses have spread throughout the Cabo Verde population. It also demonstrates the utility of serological assay formats for outbreak investigations.


Assuntos
Infecções por Arbovirus , Febre de Chikungunya , Vírus da Dengue , Dengue , Infecção por Zika virus , Zika virus , Infecções por Arbovirus/epidemiologia , Cabo Verde , Febre de Chikungunya/epidemiologia , Surtos de Doenças , Feminino , Humanos , Infecção por Zika virus/epidemiologia
7.
PLoS One ; 17(1): e0262388, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35015781

RESUMO

The management of myeloma in the elderly is shifting its focus towards reducing the risk of under-treating fit patients and the risk of over-treating frail patients. Frailty assessment is required in this patient group in order to individualise treatment decisions. In addition to the proven prognostic values of the International Myeloma Working Group (IMWG) frailty score and the revised Myeloma Co-morbidity Index (R-MCI), a new easy-to-use frailty-based risk profile score (high-risk (i.e. frail), medium risk (i.e. intermediate-fitness) and low-risk (i.e. fit)) named Myeloma Risk Profile (MRP) was shown to be predictive of survival in the clinical trial setting. In this retrospective real-world study, we set out to evaluate the frailty characteristics and clinical outcomes according to the different MRP scoring algorithm categories (frail vs. intermediate vs fit), in a high risk cohort of elderly newly diagnosed myeloma patients treated with the fixed-duration triplet therapy VCD (bortezomib with cyclophosphamide and dexamethasone). Clinical outcomes included: reason for treatment discontinuation, overall response rate (ORR), overall survival (OS), progression-free survival (PFS), and adverse events (AEs). Out of 100 patients, 62 were frail, 27 were intermediate and 11 were fit, according to MRP scores. To enable meaningful comparisons between comparable numbers, subgroups analyses for ORR, OS, PFS, and AEs focused on frail (n = 62) versus intermediate or fit (n = 38) patients. The proportion of patients in each subgroup who were able to complete the planned course of treatment was (frail: 43.5% vs. intermediate or fit: 55.3%). A higher proportion in the frail subgroup discontinued therapy due to progressive disease (19.4% vs. 2.6%). Discontinuation due to toxicity was comparable across subgroups (14.5% vs. 15.8%), ORR in the total cohort was 75%, and this was comparable between subgroups (frail: 74.2% vs. intermediate or fit: 76.3%). There was a trend for a shorter median OS in the frail subgroup but without a statistical significance: (frail vs. intermediate or fit): (46 months vs. not reached, HR: 1.94, 95% CI 0.89-4.2, p = 0.094). There was no difference in median PFS between subgroups: (frail vs. intermediate or fit): (11.8 vs. 9.9 months, HR: 0.99, 95% CI: 0.61-1.61, P = 0.982). This cohort demonstrated a higher incidence rate of AEs in frail patients compared to those in the intermediate or fit group: patients with at least one any grade toxicity (85.5% vs. 71.1%), patients with at least one ≥G3 AE (37.1% vs. 21.1%). In conclusion, our study is to the first to evaluate clinical outcomes according to MRP in a high risk real-world cohort of patients treated exclusively with the proteasome inhibitor-based VCD therapy. Our study demonstrated a trend for worse OS in addition to worse AE outcomes in the frail group, but no difference in PFS with this fixed-duration therapy. MRP is an easy-to-use tool in clinical practice; its prognostic value was validated in the real-world in a large cohort of patients from the Danish Registry. Further evaluation of MRP in the real-world when continuous therapies are used, can further support the generalisability of its prognostic value in elderly myeloma patients.


Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Fragilidade/diagnóstico , Modelos Estatísticos , Mieloma Múltiplo/mortalidade , Idoso , Idoso de 80 Anos ou mais , Bortezomib/administração & dosagem , Ciclofosfamida/administração & dosagem , Dexametasona/administração & dosagem , Feminino , Seguimentos , Humanos , Lenalidomida/administração & dosagem , Masculino , Mieloma Múltiplo/tratamento farmacológico , Mieloma Múltiplo/epidemiologia , Mieloma Múltiplo/patologia , Prognóstico , Estudos Retrospectivos , Taxa de Sobrevida , Reino Unido/epidemiologia
8.
Tuberculosis (Edinb) ; 131: 102137, 2021 12.
Artigo em Inglês | MEDLINE | ID: mdl-34673379

RESUMO

Treatment of drug-resistant tuberculosis requires extended use of more toxic and less effective drugs and may result in retreatment cases due to failure, abandonment or disease recurrence. It is therefore important to understand the evolutionary process of drug resistance in Mycobacterium tuberculosis. We here in describe the microevolution of drug resistance in serial isolates from six previously treated patients. Drug resistance was initially investigated through phenotypic methods, followed by genotypic approaches. The use of whole-genome sequencing allowed the identification of mutations in the katG, rpsL and rpoB genes associated with drug resistance, including the detection of rare mutations in katG and mixed populations of strains. Molecular docking simulation studies of the impact of observed mutations on isoniazid binding were also performed. Whole-genome sequencing detected 266 single nucleotide polymorphisms between two isolates obtained from one patient, suggesting a case of exogenous reinfection. In conclusion, sequencing technologies can detect rare mutations related to drug resistance, identify subpopulations of resistant strains, and identify diverse populations of strains due to exogenous reinfection, thus improving tuberculosis control by guiding early implementation of appropriate clinical and therapeutic interventions.


Assuntos
Resistência a Medicamentos/genética , Estudo de Associação Genômica Ampla/estatística & dados numéricos , Mycobacterium tuberculosis/efeitos dos fármacos , Brasil , Resistência a Medicamentos/imunologia , Estudo de Associação Genômica Ampla/métodos , Humanos , Testes de Sensibilidade Microbiana/métodos , Testes de Sensibilidade Microbiana/estatística & dados numéricos , Mycobacterium tuberculosis/imunologia , Mycobacterium tuberculosis/isolamento & purificação , Tuberculose Resistente a Múltiplos Medicamentos/microbiologia
9.
Prog Neurobiol ; 205: 102124, 2021 10.
Artigo em Inglês | MEDLINE | ID: mdl-34314775

RESUMO

With a diverse set of neuronal and glial cell populations, Central Nervous System (CNS) has one of the most complex structures in the body. Intercellular communication is therefore highly important to coordinate cell-to-cell interactions. Besides electrical and chemical messengers, CNS cells also benefit from another communication route, what is known as extracellular vesicles, to harmonize their interactions. Extracellular Vesicles (EVs) and their subtype exosomes are membranous particles secreted by cells and contain information packaged in the form of biomolecules such as small fragments of DNA, lipids, miRNAs, mRNAs, and proteins. They are able to efficiently drive changes upon their arrival to recipient cells. EVs actively participate in all stages of CNS development by stimulating neural cell proliferation, differentiation, synaptic formation, and mediating reciprocal interactions between neurons and oligodendrocyte for myelination process. The aim of the present review is to enlighten the presence and contribution of EVs at each CNS developmental milestone.


Assuntos
Vesículas Extracelulares , Comunicação Celular , Sistema Nervoso Central , Exossomos , Neurônios
10.
Int J Mol Sci ; 22(9)2021 May 10.
Artigo em Inglês | MEDLINE | ID: mdl-34068678

RESUMO

The liver is among the most frequently targeted organs by noxious chemicals of diverse nature. Liver toxicity testing using laboratory animals not only raises serious ethical questions, but is also rather poorly predictive of human safety towards chemicals. Increasing attention is, therefore, being paid to the development of non-animal and human-based testing schemes, which rely to a great extent on in vitro methodology. The present paper proposes a rationalized tiered in vitro testing strategy to detect liver toxicity triggered by chemicals, in which the first tier is focused on assessing general cytotoxicity, while the second tier is aimed at identifying liver-specific toxicity as such. A state-of-the-art overview is provided of the most commonly used in vitro assays that can be used in both tiers. Advantages and disadvantages of each assay as well as overall practical considerations are discussed.


Assuntos
Doença Hepática Induzida por Substâncias e Drogas/genética , Técnicas In Vitro/tendências , Fígado/efeitos dos fármacos , Testes de Toxicidade/tendências , Animais , Doença Hepática Induzida por Substâncias e Drogas/patologia , Humanos , Modelos Animais , Medição de Risco
11.
Future Cardiol ; 17(8): 1359-1369, 2021 11.
Artigo em Inglês | MEDLINE | ID: mdl-33871286

RESUMO

Aim: Patients with chronic kidney disease (CKD) are at increased cardiovascular risk. Methods: Patients with acute coronary syndrome were retrospectively allocated to three groups (stage 3A, stage 3B or stage 4) based on the Kidney Disease Improving Global Outcomes classification formulas: the CKD Epidemiology Collaboration (CKD-EPI; N = 401) and the modification of diet in renal disease (n = 355). The primary end point was all-cause mortality (median follow-up time, 32 months [15-70]). Results: Study results showed decreased median survival was associated with poor renal function for both the CKD-EPI (78 vs 61 vs 40 months, p = 0.014) and modification of diet in renal disease groups (68 vs 57 vs 32 months, p = 0.006). After adjustment, age (OR: 1.07; 95% CI: 1.01-1.14) and pulmonary artery systolic pressure (OR: 1.08; 95% CI: 1.03-1.14), but not estimated glomerular filtration rate, were associated with decreased survival. Conclusion: Study results suggest that poor outcomes after an acute coronary syndrome were associated with comorbidities rather than estimated glomerular filtration rate level.


Lay abstract Patients with chronic kidney failure have an elevated risk of heart attack or death. We studied patients with kidney failure and concurrent heart attack for 32 months (median). Our results suggest that poorer renal function was associated with an increased risk of death. However, the most important factors associated with survival were patient age and pulmonary artery systolic pressure and not the particular kidney function. Therefore, in this group of patients, comorbidities appear to play a role as survival determinants.


Assuntos
Síndrome Coronariana Aguda , Insuficiência Renal Crônica , Síndrome Coronariana Aguda/complicações , Síndrome Coronariana Aguda/epidemiologia , Taxa de Filtração Glomerular , Humanos , Rim , Insuficiência Renal Crônica/complicações , Insuficiência Renal Crônica/epidemiologia , Estudos Retrospectivos
12.
Int J Mol Sci ; 22(7)2021 Apr 03.
Artigo em Inglês | MEDLINE | ID: mdl-33916879

RESUMO

Rett syndrome (RTT) is a neurodevelopmental disorder caused by mutations in the gene encoding the methyl-CpG-binding protein 2 (MeCP2). Among many different roles, MeCP2 has a high phenotypic impact during the different stages of brain development. Thus, it is essential to intensively investigate the function of MeCP2, and its regulated targets, to better understand the mechanisms of the disease and inspire the development of possible therapeutic strategies. Several animal models have greatly contributed to these studies, but more recently human pluripotent stem cells (hPSCs) have been providing a promising alternative for the study of RTT. The rapid evolution in the field of hPSC culture allowed first the development of 2D-based neuronal differentiation protocols, and more recently the generation of 3D human brain organoid models, a more complex approach that better recapitulates human neurodevelopment in vitro. Modeling RTT using these culture platforms, either with patient-specific human induced pluripotent stem cells (hiPSCs) or genetically-modified hPSCs, has certainly contributed to a better understanding of the onset of RTT and the disease phenotype, ultimately allowing the development of high throughput drugs screening tests for potential clinical translation. In this review, we first provide a brief summary of the main neurological features of RTT and the impact of MeCP2 mutations in the neuropathophysiology of this disease. Then, we provide a thorough revision of the more recent advances and future prospects of RTT modeling with human neural cells derived from hPSCs, obtained using both 2D and organoids culture systems, and its contribution for the current and future clinical trials for RTT.


Assuntos
Células-Tronco Pluripotentes Induzidas , Proteína 2 de Ligação a Metil-CpG , Modelos Neurológicos , Mutação , Organoides , Síndrome de Rett , Humanos , Células-Tronco Pluripotentes Induzidas/metabolismo , Células-Tronco Pluripotentes Induzidas/patologia , Proteína 2 de Ligação a Metil-CpG/genética , Proteína 2 de Ligação a Metil-CpG/metabolismo , Organoides/metabolismo , Organoides/patologia , Síndrome de Rett/genética , Síndrome de Rett/metabolismo , Síndrome de Rett/patologia
13.
Int J Mol Sci ; 22(7)2021 Mar 28.
Artigo em Inglês | MEDLINE | ID: mdl-33800706

RESUMO

Gap junctions and connexin hemichannels mediate intercellular and extracellular communication, respectively. While gap junctions are seen as the "good guys" by controlling homeostasis, connexin hemichannels are considered as the "bad guys", as their activation is associated with the onset and dissemination of disease. Open connexin hemichannels indeed mediate the transport of messengers between the cytosol and extracellular environment and, by doing so, fuel inflammation and cell death in a plethora of diseases. The present mini-review discusses the mechanisms involved in the activation of connexin hemichannels during pathology.


Assuntos
Membrana Celular/metabolismo , Conexinas/metabolismo , Junções Comunicantes/fisiologia , Inflamação/metabolismo , Animais , Morte Celular , Conexina 43/metabolismo , Citosol/metabolismo , Homeostase , Humanos , Concentração de Íons de Hidrogênio , Moléculas com Motivos Associados a Patógenos , Peptídeos/química , Fosforilação , Estresse Mecânico
14.
Acta Reumatol Port ; 46(1): 58-68, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33820892

RESUMO

Vasculitides have been classically considered to be mostly of autoimmune origin, but the role of the innate immune system is being increasingly recognized among primary systemic vasculitides. For example, Behçet's syndrome (BS) shares more common features with autoinflammatory disorders (AIDs) than autoimmune diseases (ADs) and has recently been considered to be a polygenic AID by several authors, while others have classified it as a "mixed-pattern" disorder. This review aims to make a balance between autoinflammatory and autoimmune features of primary systemic vasculitides, including sex prevalence, association and/or familial aggregation with others AIDs or ADs, with human leukocyte antigen (HLA) system and/or disease-specific autoantibodies, type of cellular infiltration (neutrophilic or lymphocytic), clinical pattern (episodic or progressive), size of involved joints when articular involvement occurs, presence of lymphadenopathy or hypergammaglobulinemia, and therapeutic benefit of colchicine, IL-1 inhibitors and rituximab. Except for Henöch-Schonlein purpura, autoimmunity is usually predominant in small vessel vasculitides, where disease-specific autoantibodies are common. On the other hand, medium vessel and even variable vessel vasculitides such as BS often course with autoinflammatory features (e.g. increased levels of IL-1, neutrophilic infiltration) are often more obvious than those typical of autoimmunity. Therefore, it is possible that disorders like polyarteritis nodosa or Kawasaki disease may be considered as "mixed-pattern" diseases in the future. Finally, both the innate and adaptive immune systems can have significant roles in large vessel vasculitis.


Assuntos
Doenças Autoimunes , Vasculite Sistêmica , Vasculite , Animais , Autoimunidade , Galinhas , Humanos
15.
Eur J Haematol ; 106(4): 563-573, 2021 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-33496996

RESUMO

OBJECTIVE: There are limited data on the efficacy and tolerability of VCD chemotherapy in transplant-non-eligible (TNE) newly diagnosed myeloma (NDMM) patients. In this retrospective study, we set out to evaluate this triplet combination in this setting across Thames Valley Cancer Network (UK). METHODS: The primary end point was overall response rate (ORR). Secondary outcomes included event-free survival (EFS), overall survival (OS) and adverse events (AEs). RESULTS: In a total cohort of 158 patients, ORR for total cohort was 72.1%. Median EFS was 10.5 months, and for subgroups by age (<75:11.7 vs ≥75:10.3 months, P = .124), by Charlson Co-morbidity Index (CCI) (<5:11.1 vs ≥5:8.2 months, P = .345). The 4-month landmark analysis showed the following median EFS results: by cumulative bortezomib dose (≥26 mg/m2 : 9.0 months vs <26 mg/m2 : 6.4, P = .13), by cumulative cyclophosphamide dose (≥7000 mg: 9.2 vs <7000 mg: 7.0 months, P = .02) and by cumulative dexamethasone dose (>600 mg: 7.8 vs ≤600 mg: 8.3 months, P = .665). Median OS was 46.9 months. The incidence rate of AE was as follows: any grade (76.8%), ≥G3 (27.1%), ≥G3 haematological AEs (7.9%), any grade infections (31.1%) and ≥G3 infections (11.9%). CONCLUSION: This study demonstrated a good ORR achieved from fixed duration VCD, which was reasonably well tolerated. This was followed by modest median EFS. We envisage that the latter may be improved in this patient group with the use of a higher cumulative bortezomib dose (≥26 mg/m2 ) which showed a trend for improved EFS although without statistical significance (P = .13), and with the use of a higher cumulative cyclophosphamide doses (≥7000 mg, P = .02), subject to tolerability and close monitoring.


Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Mieloma Múltiplo/tratamento farmacológico , Mieloma Múltiplo/epidemiologia , Idoso , Idoso de 80 Anos ou mais , Protocolos de Quimioterapia Combinada Antineoplásica/efeitos adversos , Tomada de Decisão Clínica , Ciclofosfamida/efeitos adversos , Ciclofosfamida/uso terapêutico , Dexametasona/efeitos adversos , Dexametasona/uso terapêutico , Gerenciamento Clínico , Feminino , Pesquisas sobre Atenção à Saúde , Humanos , Masculino , Pessoa de Meia-Idade , Mieloma Múltiplo/diagnóstico , Mieloma Múltiplo/mortalidade , Prognóstico , Teniposídeo/efeitos adversos , Teniposídeo/uso terapêutico , Resultado do Tratamento , Reino Unido/epidemiologia
16.
Cell Microbiol ; 23(4): e13303, 2021 04.
Artigo em Inglês | MEDLINE | ID: mdl-33340385

RESUMO

Guanine-quadruplexes (G4s) are non-canonical DNA structures that can regulate key biological processes such as transcription, replication and telomere maintenance in several organisms including eukaryotes, prokaryotes and viruses. Recent reports have identified the presence of G4s within the AT-rich genome of Plasmodium falciparum, the protozoan parasite causing malaria. In Plasmodium, potential G4-forming sequences (G4FS) are enriched in the telomeric and sub-telomeric regions of the genome where they are associated with telomere maintenance and recombination events within virulence genes. However, there is a little understanding about the biological role of G4s and G4-binding proteins. Here, we provide the first snapshot of G4-interactome in P. falciparum using DNA pull-down assay followed by LC-MS/MS. Interestingly, we identified ~24 potential G4-binding proteins (G4-BP) that bind to a stable G4FS (AP2_G4). Furthermore, we characterised the role of G-strand binding protein 2 (PfGBP2), a putative telomere-binding protein in P. falciparum. We validated the interaction of PfGBP2 with G4 in vitro as well as in vivo. PfGBP2 is expressed throughout the intra-erythrocytic developmental cycle and is essential for the parasites in the presence of G4-stabilising ligand, pyridostatin. Gene knockout studies showed the role of PfGBP2 in the expression of var genes. Taken together, this study suggests that PfGBP2 is a bona fide G4-binding protein, which is likely to be involved in the regulation of G4-related functions in these malarial parasites. In addition, this study sheds light on this understudied G4 biology in P. falciparum.


Assuntos
Quadruplex G , Proteínas de Ligação ao GTP/genética , Proteínas de Ligação ao GTP/metabolismo , Plasmodium falciparum/genética , Proteínas de Transporte , Cromatografia Líquida , Humanos , Plasmodium falciparum/metabolismo , Regiões Promotoras Genéticas , Ligação Proteica , Espectrometria de Massas em Tandem
17.
Front Cell Dev Biol ; 8: 610427, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33363173

RESUMO

Engineering brain organoids from human induced pluripotent stem cells (hiPSCs) is a powerful tool for modeling brain development and neurological disorders. Rett syndrome (RTT), a rare neurodevelopmental disorder, can greatly benefit from this technology, since it affects multiple neuronal subtypes in forebrain sub-regions. We have established dorsal and ventral forebrain organoids from control and RTT patient-specific hiPSCs recapitulating 3D organization and functional network complexity. Our data revealed a premature development of the deep-cortical layer, associated to the formation of TBR1 and CTIP2 neurons, and a lower expression of neural progenitor/proliferative cells in female RTT dorsal organoids. Moreover, calcium imaging and electrophysiology analysis demonstrated functional defects of RTT neurons. Additionally, assembly of RTT dorsal and ventral organoids revealed impairments of interneuron's migration. Overall, our models provide a better understanding of RTT during early stages of neural development, demonstrating a great potential for personalized diagnosis and drug screening.

18.
Int J Mol Sci ; 21(24)2020 Dec 11.
Artigo em Inglês | MEDLINE | ID: mdl-33322331

RESUMO

The central nervous system (CNS) is the most complex structure in the body, consisting of multiple cell types with distinct morphology and function. Development of the neuronal circuit and its function rely on a continuous crosstalk between neurons and non-neural cells. It has been widely accepted that extracellular vesicles (EVs), mainly exosomes, are effective entities responsible for intercellular CNS communication. They contain membrane and cytoplasmic proteins, lipids, non-coding RNAs, microRNAs and mRNAs. Their cargo modulates gene and protein expression in recipient cells. Several lines of evidence indicate that EVs play a role in modifying signal transduction with subsequent physiological changes in neurogenesis, gliogenesis, synaptogenesis and network circuit formation and activity, as well as synaptic pruning and myelination. Several studies demonstrate that neural and non-neural EVs play an important role in physiological and pathological neurodevelopment. The present review discusses the role of EVs in various neurodevelopmental disorders and the prospects of using EVs as disease biomarkers and therapeutics.


Assuntos
Doenças do Sistema Nervoso Central/metabolismo , Exossomos/metabolismo , Vesículas Extracelulares/metabolismo , Animais , Humanos , Neurônios/metabolismo
19.
Parasit Vectors ; 13(1): 481, 2020 Sep 21.
Artigo em Inglês | MEDLINE | ID: mdl-32958043

RESUMO

BACKGROUND: Aedes spp. are responsible for the transmission of many arboviruses, which contribute to rising human morbidity and mortality worldwide. The Aedes aegypti mosquito is a main vector for chikungunya, dengue and yellow fever infections, whose incidence have been increasing and distribution expanding. This vector has also driven the emergence of the Zika virus (ZIKV), first reported in Africa which spread rapidly to Asia and more recently across the Americas. During the outbreak in the Americas, Cape Verde became the first African country declaring a Zika epidemic, with confirmed cases of microcephaly. Here we investigate the prevalence of ZIKV and dengue (DENV) infected Ae. aegypti mosquitoes in the weeks following the outbreak in Cape Verde, and the presence of insecticide resistance in the circulating vector population. Genetic diversity in the mosquito population was also analysed. METHODS: From August to October 2016, 816 Ae. aegypti mosquitoes were collected in several locations across Praia, Cape Verde, the major hot spot of reported ZIKV cases in the country. All mosquitoes were screened by reverse transcription PCR for ZIKV and DENV, and a subset (n = 220) were screened for knockdown insecticide resistance associated mutations in the voltage gated sodium channel (VGSC) gene by capillary sequencing. The mitochondrial NADH dehydrogenase subunit 4 (nad4) gene was sequenced in 100 mosquitoes. These data were compared to 977 global sequences in a haplotype network and a phylogenetic tree analysis. RESULTS: Two Ae. aegypti mosquitoes were ZIKV positive (0.25%). There were no SNP mutations found in the VGSC gene associated with insecticide resistance. Analysis of the nad4 gene revealed 11 haplotypes in the Cape Verdean samples, with 5 being singletons. Seven haplotypes were exclusive to Cape Verde. Several of the remaining haplotypes were frequent in the global dataset, being present in several countries (including Cape Verde) across five different continents. The most common haplotype in Cape Verde (50.6 %) was also found in Africa and South America. CONCLUSIONS: There was low-level Zika virus circulation in mosquitoes from Praia shortly after the outbreak. The Ae. aegypti population did not appear to have the kdr mutations associated with pyrethroid resistance. Furthermore, haplotype and phylogenetic analyses revealed that Cape Verde Ae. aegypti mosquitoes are most closely related to those from other countries in Africa and South America.


Assuntos
Aedes/genética , Resistência a Inseticidas , Mosquitos Vetores/genética , Infecção por Zika virus/transmissão , Zika virus/fisiologia , Aedes/efeitos dos fármacos , Aedes/fisiologia , Aedes/virologia , Animais , Cabo Verde , Dengue/transmissão , Dengue/virologia , Vírus da Dengue/genética , Vírus da Dengue/fisiologia , Feminino , Variação Genética , Humanos , Inseticidas/farmacologia , Masculino , Mosquitos Vetores/efeitos dos fármacos , Mosquitos Vetores/fisiologia , Mosquitos Vetores/virologia , Filogenia , Dinâmica Populacional , Zika virus/genética , Infecção por Zika virus/virologia
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