Your browser doesn't support javascript.
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 1.487
Filtrar
1.
Phys Chem Chem Phys ; 22(8): 4464-4480, 2020 Feb 26.
Artigo em Inglês | MEDLINE | ID: mdl-32057044

RESUMO

Infection by human immunodeficiency virus type 1 (HIV-1) not only destroys the immune system bringing about acquired immune deficiency syndrome (AIDS), but also induces serious neurological diseases including behavioral abnormalities, motor dysfunction, toxoplasmosis, and HIV-1 associated dementia. The emergence of HIV-1 multidrug-resistant mutants has become a major problem in the therapy of patients with HIV-1 infection. Focusing on the wild type (WT) and G48T/L89M mutated forms of HIV-1 protease (HIV-1 PR) in complex with amprenavir (APV), indinavir (IDV), ritonavir (RTV), and nelfinavir (NFV), we have investigated the conformational dynamics and the resistance mechanism due to the G48T/L89M mutations by conducting a series of molecular dynamics (MD) simulations and free energy (MM-PBSA and solvated interaction energy (SIE)) analyses. The simulation results indicate that alterations in the side-chains of G48T/L89M mutated residues cause the inner active site to increase in volume and induce more curling of the flap tips, which provide the main contributions to weaker binding of inhibitors to the HIV-1 PR. The results of energy analysis reveal that the decrease in van der Waals interactions of inhibitors with the mutated PR relative to the wild-type (WT) PR mostly drives the drug resistance of mutations toward these four inhibitors. The energy decomposition analysis further indicates that the drug resistance of mutations can be mainly attributed to the change in van der Waals and electrostatic energy of some key residues (around Ala28/Ala28' and Ile50/Ile50'). Our work can give significant guidance to design a new generation of anti-AIDS inhibitors targeting PR in the therapy of patients with HIV-1 infection.


Assuntos
Protease de HIV/metabolismo , Simulação de Dinâmica Molecular , Fármacos Anti-HIV/química , Fármacos Anti-HIV/metabolismo , Carbamatos/química , Carbamatos/metabolismo , Resistência a Medicamentos/efeitos dos fármacos , Resistência a Medicamentos/genética , Protease de HIV/genética , Indinavir/química , Indinavir/metabolismo , Conformação Molecular , Mutação , Nelfinavir/química , Nelfinavir/metabolismo , Ligação Proteica , Ritonavir/química , Ritonavir/metabolismo , Sulfonamidas/química , Sulfonamidas/metabolismo
2.
Aquat Toxicol ; 218: 105334, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31743820

RESUMO

Tributyltin (TBT) and dioxin-like polychlorinated biphenyls (PCBs) are environmental contaminants that are highly toxic to fish and co-occur in New Bedford Harbor (NBH), an estuarine Superfund site located in Massachusetts, USA. Atlantic killifish (Fundulus heteroclitus) that reside in NBH (and other highly contaminated sites along the east coast of the United States) have developed resistance to activation of the aryl hydrocarbon receptor (AHR) pathway and the toxicity of dioxin-like chemicals, such as 3,3',4,4',5-pentachlorobiphenyl, PCB126. In many biological systems, TBT disregulates adipose and bone development via the PPARγ-RXR pathway; AHR activation also disrupts adipose and bone homeostasis, potentially through molecular crosstalk between AHR and PPARγ. However, little is known about how co-exposure and the interaction of these pathways modulate the toxicological effects of these contaminants. Here, we tested the hypotheses that TBT would induce teratogenesis in killifish via activation of PPARγ and that PCB126 co-exposure would suppress PPARγ pathway activation in PCB-sensitive killifish from a reference site (Scorton Creek, SC, PCB-sensitive) but not in PCB-tolerant NBH killifish. Killifish embryos from both populations exposed to TBT (50 and 100 nM) displayed caudal fin deformities. TBT did not change the expression of pparg or its target genes related to adipogenesis (fabp11a and fabp1b) in either population. However, expression of osx/sp7, an osteoblast marker gene, and col2a1b, a chondroblast marker gene, was significantly suppressed by TBT only in SC killifish. An RXR-specific agonist, but not a PPARγ-specific agonist, induced caudal fin deformities like those observed in TBT-treated embryos. PCB126 did not induce caudal fin deformities and did not exacerbate TBT-induced fin deformities. Further, PCB126 increased expression of pparg in SC embryos and not NBH embryos, but did not change the expression of fabp1b. Taken together, these results suggest that in killifish embryos the PPARγ pathway is regulated in part by AHR, but is minimally active at least in this early life stage. In killifish, RXR activation, rather than PPARγ activation, appears to be the mechanism by which TBT induces caudal fin teratogenicity, which is not modulated by AHR responsiveness.


Assuntos
Nadadeiras de Animais/efeitos dos fármacos , Embrião não Mamífero/efeitos dos fármacos , Fundulidae , PPAR gama/metabolismo , Bifenilos Policlorados/toxicidade , Receptores de Hidrocarboneto Arílico/metabolismo , Compostos de Trialquitina/toxicidade , Poluentes Químicos da Água/toxicidade , Nadadeiras de Animais/anormalidades , Animais , Resistência a Medicamentos/efeitos dos fármacos , Sinergismo Farmacológico , Embrião não Mamífero/anormalidades , Embrião não Mamífero/metabolismo , Desenvolvimento Embrionário/efeitos dos fármacos , Regulação da Expressão Gênica no Desenvolvimento/efeitos dos fármacos , Massachusetts , PPAR gama/genética , Receptor Cross-Talk , Receptores de Hidrocarboneto Arílico/genética , Transdução de Sinais/efeitos dos fármacos
3.
Chemosphere ; 240: 124857, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31726599

RESUMO

Colorado potato beetle, Leptinotarsa decemlineata Say (coleoptera: chrysomelidae), is the important pest of potato all over the world. This insect pest is resistant to more than 50 active compounds belonging to various chemical groups. Potential of RNA interference (RNAi) was explored to knock down transcript levels of imidacloprid resistant genes in Colorado potato beetle (CPB) under laboratory conditions. Three important genes belonging to cuticular protein (CP), cytochrome P450 monoxygenases (P450) and glutathione synthetase (GSS) families encoding imidacloprid resistance were targeted. Feeding bio-assays were conducted on various stages of imidacloprid resistant CPB lab population by applying HT115 expressing dsRNA on potato leaflets. Survival rate of insects exposed to CP-dsRNA decreased to 4.23%, 15.32% and 47.35% in 2nd, 3rd and 4th instar larvae respectively. Larval weight and pre-adult duration were also affected due to dsRNAs feeding. Synergism of RNAi with imidacloprid conducted on the 2nd instar larvae, exhibited 100% mortality of larvae when subjected to reduced doses of GSS and CP dsRNAs along with imidacloprid. Utilization of three different dsRNAs against imidacloprid resistant CPB population reveal that dsRNAs targeting CP, P450 and GSS enzymes could be useful tool in management of imidacloprid resistant CPB populations.


Assuntos
Besouros/genética , Resistência a Medicamentos/genética , Genes de Insetos , Inseticidas/farmacologia , Larva/metabolismo , Neonicotinoides/farmacologia , Nitrocompostos/farmacologia , Animais , Besouros/efeitos dos fármacos , Besouros/crescimento & desenvolvimento , Sistema Enzimático do Citocromo P-450/genética , Regulação para Baixo , Resistência a Medicamentos/efeitos dos fármacos , Glutationa Sintase/genética , Larva/efeitos dos fármacos , Larva/genética , Interferência de RNA/efeitos dos fármacos , Solanum tuberosum/crescimento & desenvolvimento
4.
Ann Hematol ; 99(2): 343-349, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31879790

RESUMO

Ruxolitinib is a promising option for treating steroid-refractory acute graft-versus-host disease (SR-aGVHD) after allogeneic hematopoietic stem cell transplantation (allo-HSCT). In this study, we describe ruxolitinib treatment for SR-aGVHD in HSCT patients with Epstein-Barr virus-associated hemophagocytic lymphohistiocytosis (EBV-HLH) to evaluate its effectiveness. We evaluated the outcomes of 12 patients who received ruxolitinib for SR-aGVHD between January 2017 and March 2019. Of the 12 patients who received ruxolitinib, 7 patients achieved a complete response (CR), 3 had a partial response (PR), and 2 experienced treatment failure (TF). OS and CR rates were 83.3% and 58.3%, respectively. Moreover, CR was achieved by the six patients who had aGVHD with skin involvement. The mean time of steroid application in the patients who received ruxolitinib was 28.1 days. Median survival after HSCT was 64.6 weeks. The adverse effects of ruxolitinib included grades 3 to 4 neutropenia (n = 7) and grades 3 to 4 thrombocytopenia (n = 6). Cytomegalovirus reactivation was observed in three patients. A high rate of CR and short steroid application time of ruxolitinib as a salvage treatment were observed in HSCT patients with EBV-HLH. Consequently, from this study, it was determined that ruxolitinib is an optimal choice to treat SR-aGVHD in patients with EBV-HLH.


Assuntos
Infecções por Vírus Epstein-Barr , Doença Enxerto-Hospedeiro , Transplante de Células-Tronco Hematopoéticas , Herpesvirus Humano 4 , Linfo-Histiocitose Hemofagocítica , Pirazóis/administração & dosagem , Dermatopatias , Doença Aguda , Adolescente , Adulto , Aloenxertos , Criança , Intervalo Livre de Doença , Resistência a Medicamentos/efeitos dos fármacos , Infecções por Vírus Epstein-Barr/mortalidade , Infecções por Vírus Epstein-Barr/terapia , Doença Enxerto-Hospedeiro/tratamento farmacológico , Doença Enxerto-Hospedeiro/mortalidade , Humanos , Linfo-Histiocitose Hemofagocítica/mortalidade , Linfo-Histiocitose Hemofagocítica/terapia , Masculino , Estudos Retrospectivos , Dermatopatias/tratamento farmacológico , Dermatopatias/mortalidade , Esteroides/administração & dosagem , Taxa de Sobrevida
5.
Acta Trop ; 201: 105213, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31600523

RESUMO

The aim of the present study was to evaluate the in vitro effect of quercetin combined with ivermectin (IVM) on Haemonchus contortus larvae and adults with different resistance profiles and demonstrate the in vivo anthelmintic action of this combination when used in sheep naturally infected. The effect of combination was evaluated based on the analysis of the mean effective concentration (EC50) obtained for larvae using the larval migration inhibition test and for adults using the motility test on females. The tests with larvae and adults were conducted using isolates with different degrees of susceptibility to IVM (sensitive, intermediate and highly resistant). The in vivo effect was evaluated based on the reduction in the egg count (FEC) and reduction in the count of adult helminths recovered after parasitological necropsy. Using the combination of quercetin with IVM, it was observed that in larvae, quercetin did not significantly reduce the EC50 for IVM in the sensitive and highly resistant isolates, but led to a significant reduction in the EC50 for IVM in the intermediate isolate. In adults, quercetin did not significantly reduce the EC50 for IVM in any of the isolates. No significant effect of the combination was found regarding the reduction in FEC or total count of parasites. The results of the in vitro and in vivo tests performed in the present study on quercetin activity underscore the importance of evaluating resistance-reversing agents among different stages of parasite development as well as among isolates with different resistance profiles. The action of quercetin combined with IVM on the motility of H. contortus larvae and adults was influenced by the degree of resistance and development stage of the parasite. The combination was effective only on intermediate resistant larvae. No action of the combination against adults was found. Moreover, this combination, when administered through the intra-abomasal route, was not effective at reducing the FEC and parasite load of naturally infected sheep.


Assuntos
Anti-Helmínticos/uso terapêutico , Resistência a Medicamentos/efeitos dos fármacos , Hemoncose/tratamento farmacológico , Haemonchus/efeitos dos fármacos , Ivermectina/uso terapêutico , Larva/efeitos dos fármacos , Quercetina/uso terapêutico , Doenças dos Ovinos/tratamento farmacológico , Animais , Feminino , Masculino , Contagem de Ovos de Parasitas , Ovinos/parasitologia , Doenças dos Ovinos/parasitologia
7.
Arch. bronconeumol. (Ed. impr.) ; 55(12): 627-633, dic. 2019. graf
Artigo em Espanhol | IBECS | ID: ibc-186396

RESUMO

Introduction: Lung cancer is a major public health problem, as the second causes of cancer related death worldwide, with relatively low survival rates, and accessible drug resistance. Long non-coding RNAs (LncRNAs) have been identified as activator in lung cancer with elusive mechanisms. We aimed to detect the regulation of LncRNA MALAT1 in the proliferation and gefitinib resistance in lung cancer cells. Methods: MALAT1 in A549 and HCC 1299 human lung adenocarcinoma cell lines was silenced by shRNA or overexpressed using plasmid, and the cell viability and cell proliferation were evaluated by MTT assay and soft agar colony formation assay. RNA levels were detected by RT-PCR, and the protein expression was measured by western blot. The binding between MALAT1 and miR-200a was validated by luciferase reporter assays using pSi-Chech 2 vectors. Results: The cell viability and proliferation of A549 cells transfected with MALAT1 shRNA were significantly lower than the control. The MALAT1 expression in gefitinib resistant A549 cells was upregulated. miR-200a significantly inhibited the fluorescence of pSi-Check 2 vector with MALAT1 gene, suggesting the direct binding between MALAT1 and miR-200a. In addition, LncRNA MALAT1 promotes ZEB1 expression in A549 cells. Conclusion: Our study showed that MALAT1 promoted the proliferation and gefitinib resistance of lung cancer cells by sponging miR-200a, which regulates expression of ZEB1 in the A549 cells. This MALAT1/miR-200a axis could serve as new therapeutic target for lung cancer treatment


Introducción: El cáncer de pulmón es un importante problema de salud pública. Constituye la segunda causa de muerte por cáncer en el mundo y se asocia a tasas de supervivencia relativamente bajas y a resistencia a fármacos accesibles. Los RNA largos no-codificantes (lncRNA) se han identificado como activadores en el cáncer de pulmón con mecanismos aún no esclarecidos. El objetivo de este estudio fue detectar la regulación del LncRNA MALAT1 en la proliferación y la resistencia de las células tumorales de pulmón. Métodos: La expresión de MALAT1 se silenció con un shRNA o se sobreexpresó mediante el uso de un plásmido en las líneas celulares de adenocarcinoma pulmonar humano A459 y HCC. La viabilidad celular y la proliferación se evaluaron mediante un ensayo MTT y el ensayo de formación de colonias en agar blando. Los niveles de RNA se detectaron con RT-PCR y los niveles de proteína se midieron con Western Blot. La unión entre MALAT1 y miR-200a se validó gracias a un ensayo de luciferasa utilizando vectores pSi-Chech 2. Resultados: La viabilidad y la proliferación de las células A549 transfectadas con el shRNA contra MALAT1 resultaron significativamente más bajas que en el control. Se produjo un incremento en la expresión de MALAT1 en las células A549 resistentes a gefitinib. MiR-200a inhibió significativamente la fluorescencia del vector pSi-Check 2 que contenía el gen MALAT1, sugiriendo la unión directa entre MALAT1 y miR-200a. Además, el LncRNA de MALAT1 promovió la expresión de ZEB1 en las células A549. Conclusión: Nuestro estudio demuestra que MALAT1 promovió la proliferación y resistencia a gefitinib en células tumorales de pulmón actuando como "esponja" de miR-200a, que regula la expresión de ZEB1 en células A549


Assuntos
Humanos , MicroRNAs/genética , Proteínas de Ligação a RNA/genética , RNA Longo não Codificante/genética , Regulação Neoplásica da Expressão Gênica , Neoplasias Pulmonares/diagnóstico , Resistência a Medicamentos/efeitos dos fármacos , Adenocarcinoma/diagnóstico , Gefitinibe/uso terapêutico , Reação em Cadeia da Polimerase
8.
PLoS One ; 14(12): e0225882, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31856172

RESUMO

BACKGROUND: The WHO recommends artemisinin-based combination therapies (ACTs) for the treatment of uncomplicated falciparum malaria. Hence, monitoring the efficacy of antimalarial drugs is a key component of malaria control and elimination. The published randomized trials that assessed comparisons of ACTs for treating uncomplicated falciparum malaria reported conflicting results in treatment efficacy. A network meta-analysis is an extension of pairwise meta-analysis that can synthesize evidence simultaneously from both direct and indirect treatment comparisons. The objective was to synthesize evidence on the comparative efficacy of antimalarial drugs for treatment of uncomplicated falciparum malaria in Asian region. METHODS: Relevant randomized trials that assessed efficacy of antimalarial drugs for patients having uncomplicated falciparum malaria in Asian region were searched in health-related databases. We evaluated the methodological quality of the included studies with the Cochrane risk of bias tool. Main outcome was treatment success at day 28 as determined by the absence of parasiteamia. We performed network meta-analysis of the interventions in the trials, and assessed the overall quality of evidence using the GRADE approach. RESULTS: Seventeen randomized trials (n = 5043) were included in this network meta-analysis study. A network geometry was formed with 14 antimalarial treatment options such as artemether-lumefantrine (AL), artemisinin-piperaquine, artesunate-amodiaquine, artesunate-mefloquine (ASMQ), artesunate-chloroquine, artesunate-mefloquine home treatment, artesunate-mefloquine 2-day course, artesunate plus sulfadoxine-pyrimethamine, chloroquine, dihydroartemisinin-piperaquine (DHP), dihydroartemisinin-piperaquine home treatment, dihydroartemisinin-piperaquine 4-day course, dihydroartemisinin-piperaquine and added artesunate, sulfadoxine-pyrimethamine. A maximum number of trials included was DHP compared to ASMQ (n = 5). In general, DHP had better efficacy than AL at day 28 (DHP vs AL: OR 2.5, 95%CI:1.08-5.8). There is low certainty evidence due to limited number of studies and small trials. DISCUSSION/ CONCLUSIONS: The findings suggest the superiority of DHP (3-day course) to AL and other comparator ACTs are with the overall low/very low quality of evidence judgements. Moreover, one drug regimen is better than another is only if current drug-resistance patterns are at play. For example, the AL might be better than DHP in areas where both artemisinin and piperaquine resistance patterns are prevalent. For substantiation, well-designed larger trials from endemic countries are needed. In the light of benefit versus harm concept, future analysis with safety information is recommended.


Assuntos
Antimaláricos/uso terapêutico , Bases de Dados Factuais , Resistência a Medicamentos/efeitos dos fármacos , Malária Falciparum/tratamento farmacológico , Antimaláricos/efeitos adversos , Ásia , Humanos , Malária Falciparum/epidemiologia , Ensaios Clínicos Controlados Aleatórios como Assunto
9.
Presse Med ; 48(12): 1445-1455, 2019 Dec.
Artigo em Francês | MEDLINE | ID: mdl-31761607

RESUMO

The Hormonal assessment of Arterial Hypertension (HTA) is an important part of the balance of resistant hypertension. This assessment - going well beyond the search for primary hyperaldosteronism (PHA) - requires a rigorous methodology and a robust experience of the nursing team within a dedicated unit: the HTA Day Hospital. If all the conditions are met and the assessment carried out well, it will allow a significant profitability since in this resistant hypertensive population it will detect a particular mechanism or secondary hypertension in 70% of patients. Since the diagnosis of PHA is essentially biological, the proper execution of the various stages of the assessment is essential to its documentation.


Assuntos
Técnicas de Diagnóstico Endócrino , Hormônios/análise , Hipertensão/diagnóstico , Aldosterona/análise , Aldosterona/sangue , Anti-Hipertensivos/uso terapêutico , Análise Química do Sangue/métodos , Análise Química do Sangue/normas , Diagnóstico Diferencial , Técnicas de Diagnóstico Endócrino/normas , Resistência a Medicamentos/efeitos dos fármacos , Hormônios/sangue , Humanos , Hiperaldosteronismo/diagnóstico , Hipertensão/sangue , Hipertensão/tratamento farmacológico , Hipertensão/etiologia , Renina/análise , Renina/sangue
10.
Nature ; 576(7786): 315-320, 2019 12.
Artigo em Inglês | MEDLINE | ID: mdl-31776516

RESUMO

The emergence and spread of drug-resistant Plasmodium falciparum impedes global efforts to control and eliminate malaria. For decades, treatment of malaria has relied on chloroquine (CQ), a safe and affordable 4-aminoquinoline that was highly effective against intra-erythrocytic asexual blood-stage parasites, until resistance arose in Southeast Asia and South America and spread worldwide1. Clinical resistance to the chemically related current first-line combination drug piperaquine (PPQ) has now emerged regionally, reducing its efficacy2. Resistance to CQ and PPQ has been associated with distinct sets of point mutations in the P. falciparum CQ-resistance transporter PfCRT, a 49-kDa member of the drug/metabolite transporter superfamily that traverses the membrane of the acidic digestive vacuole of the parasite3-9. Here we present the structure, at 3.2 Å resolution, of the PfCRT isoform of CQ-resistant, PPQ-sensitive South American 7G8 parasites, using single-particle cryo-electron microscopy and antigen-binding fragment technology. Mutations that contribute to CQ and PPQ resistance localize primarily to moderately conserved sites on distinct helices that line a central negatively charged cavity, indicating that this cavity is the principal site of interaction with the positively charged CQ and PPQ. Binding and transport studies reveal that the 7G8 isoform binds both drugs with comparable affinities, and that these drugs are mutually competitive. The 7G8 isoform transports CQ in a membrane potential- and pH-dependent manner, consistent with an active efflux mechanism that drives CQ resistance5, but does not transport PPQ. Functional studies on the newly emerging PfCRT F145I and C350R mutations, associated with decreased PPQ susceptibility in Asia and South America, respectively6,9, reveal their ability to mediate PPQ transport in 7G8 variant proteins and to confer resistance in gene-edited parasites. Structural, functional and in silico analyses suggest that distinct mechanistic features mediate the resistance to CQ and PPQ in PfCRT variants. These data provide atomic-level insights into the molecular mechanism of this key mediator of antimalarial treatment failures.


Assuntos
Microscopia Crioeletrônica , Resistência a Medicamentos/efeitos dos fármacos , Proteínas de Membrana Transportadoras/química , Proteínas de Membrana Transportadoras/ultraestrutura , Plasmodium falciparum/química , Proteínas de Protozoários/química , Proteínas de Protozoários/ultraestrutura , Cloroquina/metabolismo , Cloroquina/farmacologia , Resistência a Medicamentos/genética , Concentração de Íons de Hidrogênio , Malária Falciparum/tratamento farmacológico , Malária Falciparum/parasitologia , Proteínas de Membrana Transportadoras/genética , Proteínas de Membrana Transportadoras/metabolismo , Modelos Moleculares , Mutação , Plasmodium falciparum/genética , Plasmodium falciparum/ultraestrutura , Proteínas de Protozoários/genética , Proteínas de Protozoários/metabolismo , Quinolinas/metabolismo , Quinolinas/farmacologia
11.
BMC Infect Dis ; 19(1): 872, 2019 Oct 22.
Artigo em Inglês | MEDLINE | ID: mdl-31640574

RESUMO

BACKGROUND: Drug resistant malaria is a growing concern in the Democratic Republic of the Congo (DRC), where previous studies indicate that parasites resistant to sulfadoxine/pyrimethamine or chloroquine are spatially clustered. This study explores longitudinal changes in spatial patterns to understand how resistant malaria may be spreading within the DRC, using samples from nation-wide population-representative surveys. METHODS: We selected 552 children with PCR-detectable Plasmodium falciparum infection and identified known variants in the pfdhps and pfcrt genes associated with resistance. We compared the proportion of mutant parasites in 2013 to those previously reported from adults in 2007, and identified risk factors for carrying a resistant allele using multivariate mixed-effects modeling. Finally, we fit a spatial-temporal model to the observed data, providing smooth allele frequency estimates over space and time. RESULTS: The proportion of co-occurring pfdhps K540E/A581G mutations increased by 16% between 2007 and 2013. The spatial-temporal model suggests that the spatial range of the pfdhps double mutants expanded over time, while the prevalence and range of pfcrt mutations remained steady. CONCLUSIONS: This study uses population-representative samples to describe the changing landscape of SP resistance within the DRC, and the persistence of chloroquine resistance. Vigilant molecular surveillance is critical for controlling the spread of resistance.


Assuntos
Antimaláricos/uso terapêutico , Resistência a Medicamentos/efeitos dos fármacos , Malária Falciparum/tratamento farmacológico , Plasmodium falciparum/efeitos dos fármacos , Adolescente , Adulto , Álcool Desidrogenase/genética , Cloroquina/uso terapêutico , Estudos Transversais , República Democrática do Congo/epidemiologia , Combinação de Medicamentos , Resistência a Medicamentos/genética , Frequência do Gene , Humanos , Estudos Longitudinais , Malária Falciparum/epidemiologia , Malária Falciparum/parasitologia , Proteínas de Membrana Transportadoras/genética , Pessoa de Meia-Idade , Mutação , Plasmodium falciparum/genética , Prevalência , Proteínas de Protozoários/genética , Pirimetamina/uso terapêutico , Análise Espaço-Temporal , Sulfadoxina/uso terapêutico , Adulto Jovem
12.
Mar Drugs ; 17(10)2019 Sep 26.
Artigo em Inglês | MEDLINE | ID: mdl-31561525

RESUMO

Pyrazinamide (PZA) is the only drug for the elimination of latent Mycobacterium tuberculosis (MTB) isolates. However, due to the increased number of PZA-resistance, the chances of the success of global TB elimination seems to be more prolonged. Recently, marine natural products (MNPs) as an anti-TB agent have received much attention, where some compounds extracted from marine sponge, Haliclona sp. exhibited strong activity under aerobic and hypoxic conditions. In this study, we screened articles from 1994 to 2019 related to marine natural products (MNPs) active against latent MTB isolates. The literature was also mined for the major regulators to map them in the form of a pathway under the dormant stage. Five compounds were found to be more suitable that may be applied as an alternative to PZA for the better management of resistance under latent stage. However, the mechanism of actions behind these compounds is largely unknown. Here, we also applied synthetic biology to analyze the major regulatory pathway under latent TB that might be used for the screening of selective inhibitors among marine natural products (MNPs). We identified key regulators of MTB under latent TB through extensive literature mining and mapped them in the form of regulatory pathway, where SigH is negatively regulated by RshA. PknB, RshA, SigH, and RNA polymerase (RNA-pol) are the major regulators involved in MTB survival under latent stage. Further studies are needed to screen MNPs active against the main regulators of dormant MTB isolates. To reduce the PZA resistance burden, understanding the regulatory pathways may help in selective targets of MNPs from marine natural sources.


Assuntos
Antituberculosos/uso terapêutico , Produtos Biológicos/uso terapêutico , Resistência a Medicamentos/efeitos dos fármacos , Tuberculose Latente/tratamento farmacológico , Humanos , Testes de Sensibilidade Microbiana/métodos , Mutação/efeitos dos fármacos , Mycobacterium tuberculosis/efeitos dos fármacos , Pirazinamida/uso terapêutico
13.
Eur J Med Chem ; 181: 111353, 2019 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-31525705

RESUMO

Malaria is a life threatening disease caused by microscopic parasites called Plasmodium that are transmitted to human beings by mosquitoes. Single celled Eukaryotic plasmodium parasite is responsible to cause malaria in human beings and is transmitted by bite of Anopheles species mosquitoes. Resurgence of malaria towards the end of 20th Century is due to failure of its eradication completely. Parasite recurrence occurs due to high densities of parasite, low immunity and non opimized drug concentration. The ineffective eradications strategies were due to indefinable complex life cycle of Plasmodium and emergence of drugs resistant strains of Plasmodium falciparum (Pf) including Artemisinin and Artemisinin based combination therapy (ACT). The vector of the disease i.e. mosquitoes became resistive towards Pyrethroids, which are only class of insecticides recommended for vector control. Artemisinin based combination therapy gained acceptance as an effective approach to counter the spread of disease resistance to chloroquine, sulfadoxine, pyrimethamine and other anti malarial drugs. Understanding the underlying molecular basis of the pathogenesis led to the development of some new diagnostic, drugs and insecticides. Reports on the use of new combination therapies reduced the burden of disease worldwide. Some of the new combination therapies are in clinical stage of development that have efficacy against drug resistant parasites and the potential to use in single dose regimens to improve compliance. The current review represents the recent anti-malarial research carried out globally especially in the class of synthesis of small molecule and natural product derivatives as potent anti-malarial drugs. The review also covers the advancement in the anti-malarial vaccine development although goal for vaccine development still remains elusive.


Assuntos
Antimaláricos/farmacologia , Artemisininas/farmacologia , Malária/tratamento farmacológico , Plasmodium falciparum/efeitos dos fármacos , Animais , Antimaláricos/química , Artemisininas/química , Resistência a Medicamentos/efeitos dos fármacos , Humanos
14.
Biomed Pharmacother ; 119: 109432, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31521892

RESUMO

OBJECTIVE: Methotrexate (MTX) is a commonly used drug for the treatment of rheumatoid arthritis (RA) and it has been studied in RA resistance recently. P-glycoprotein (P-gp) is one of the important transporters that mediate MTX resistance. This study investigated the effect of Paeoniflorin-6'-O-benzene sulfonate (code: CP-25) in the resistance of P-gp-mediated MTX to RA. METHODS: Adjuvant arthritis (AA) was induced in rats via complete Freund's adjuvant. The experimental groups were divided into normal group; AA model group; monotherapy groups, including CP-25, MTX and dexamethasone; and CP-25 combined with MTX group. The expression of P-gp in synovial tissue was measured by western blot and histochemistry. Besides, P-gp high expression of human hepatoma cell line Bel7402/5-FU and Bel7402 were chose to study in MTX resistance and the function of P-gp was detected by Flow cytometry. RESULTS: CP-25 had a good therapeutic effect on AA rats, significantly improved manifestations and reduced the expression of P-gp in synovial tissue, spleen medulla and small intestinal epithelial cells in the apical tissues of AA rats. In addition, CP-25 significantly inhibited the up-regulation of P-gp induced by TNF-α stimulation in synoviocytes. Furthermore, according to the accumulation and efflux of rhodamine 123 in Bel7402/5-FU resistant cells and Bel7402 sensitive cells, CP-25 could reverse the resistance of MTX in Bel7402/5-FU cells compared with Bel7402 cells, which was reflected by the reduced IC50 values of MTX. Further study indicated that CP-25 could decrease P-gp expression and inhibit P-gp function in Bel7402/5-FU cells. CONCLUSION: CP-25 regulates the expression of P-gp and inhibits the function of P-gp, thereby improving the resistance of MTX.


Assuntos
Membro 1 da Subfamília B de Cassetes de Ligação de ATP/metabolismo , Artrite Experimental/tratamento farmacológico , Artrite Experimental/metabolismo , Glucosídeos/uso terapêutico , Monoterpenos/uso terapêutico , Sinoviócitos/metabolismo , Animais , Artrite Experimental/patologia , Linhagem Celular Tumoral , Resistência a Medicamentos/efeitos dos fármacos , Glucosídeos/farmacologia , Inflamação/tratamento farmacológico , Inflamação/patologia , Intestino Delgado/efeitos dos fármacos , Intestino Delgado/patologia , Articulações/efeitos dos fármacos , Articulações/patologia , Masculino , Metotrexato/farmacologia , Metotrexato/uso terapêutico , Monoterpenos/farmacologia , Ratos Sprague-Dawley , Rodamina 123/metabolismo , Baço/efeitos dos fármacos , Baço/patologia , Sinoviócitos/efeitos dos fármacos , Sinoviócitos/patologia , Fator de Necrose Tumoral alfa/farmacologia
15.
Acta Diabetol ; 56(12): 1341-1350, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31541334

RESUMO

AIMS: To provide 2-year follow-up data on eyes with diabetic macular edema (DME) that were non-responsive after three initial anti-vascular endothelial growth factor (VEGF) injections, comparing functional and anatomical outcomes under continued anti-VEGF therapy versus dexamethasone (DEX) implant. METHODS: Multicenter, retrospective chart review comparing eyes with treatment-naïve DME and a suboptimal response to a loading phase of anti-VEGF therapy (3 injections given monthly) which were then treated with (a) further anti-VEGF (n = 72) or (b) initially switched to DEX implant (n = 38). Main outcome measures were change in visual acuity (VA) and central subfield thickness (CST) from the end of the loading phase to 24 months. RESULTS: In 79% of the 12-month study population (87/110 eyes), 24-month data were available. One quarter of eyes in each group switched treatments during the second year. Eyes that were switched early to DEX implant maintained the functional and anatomical improvements at 24 months which were seen in the first year (from month 3: + 8.9 letters, - 214 µm). Eyes that were switched from anti-VEGF therapy to steroids in the second year improved VA and reduced CST at 24 months (from month 12: + 6.8 letters, p = 0.023; - 226 µm, p = 0.004). In eyes continued on anti-VEGF therapy, VA and CST were stable at 24 months (from month 3: + 2.8 letters, p = 0.254; - 24 µm, p = 0.243). Eyes that were non-responsive to anti-VEGF therapy for 12 months had similar chances to experience a VA gain from further therapy as eyes that were non-responsive for 3 months only (23.8 vs. 31.0%, p = 0.344). CONCLUSIONS: The beneficial effect of an early switch to DEX implant in DME non-responders seen at month 12 was maintained during the second year. A later switch from anti-VEGF to steroids still provided significant improvement. Eyes continued on anti-VEGF over a period of 24 months maintained vision. A quarter of eyes, which had not improved vision at 12 months, exhibited a delayed response to treatment.


Assuntos
Inibidores da Angiogênese/administração & dosagem , Dexametasona/administração & dosagem , Retinopatia Diabética/tratamento farmacológico , Edema Macular/tratamento farmacológico , Fator A de Crescimento do Endotélio Vascular/antagonistas & inibidores , Idoso , Bevacizumab/administração & dosagem , Retinopatia Diabética/epidemiologia , Esquema de Medicação , Implantes de Medicamento , Resistência a Medicamentos/efeitos dos fármacos , Substituição de Medicamentos , Feminino , Humanos , Injeções Intravítreas , Edema Macular/epidemiologia , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Fatores de Tempo , Resultado do Tratamento , Fator A de Crescimento do Endotélio Vascular/imunologia , Acuidade Visual/efeitos dos fármacos
16.
Eur J Med Chem ; 183: 111676, 2019 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-31542713

RESUMO

Leishmaniasis, a major health problem worldwide, has a limited arsenal of drugs for its control. The appearance of resistance to first- and second-line anti-leishmanial drugs confirms the need to develop new and less toxic drugs that overcome spontaneous resistance. In the present study, we report the design and synthesis of a novel library of 38 flavonol-like compounds and their evaluation in a panel of assays encompassing parasite killing, pharmacokinetics, genomics and ADME-Toxicity resulting in the progression of a compound in the drug discovery value chain. Compound 19, 2-(benzo[b]thiophen-3-yl)-3-hydroxy-6-methoxy-4H-chromen-4-one, exhibited a broad-spectrum activity against Leishmania spp. (EC50 1.9 µM for Leishmania infantum, 3.4 µM for L. donovani, 6.7 µM for L. major), Trypanosoma cruzi (EC50 7.5 µM) and T. brucei (EC50 0.8 µM). Focusing on anti-Leishmania activity, compound 19 challenge in vitro did not select for resistance markers in L. donovani, while a Cos-Seq screening for dominant resistance genes identified a gene locus on chromosome 36 that became ineffective at concentrations beyond EC50. Thus, compound 19 is a promising scaffold to tackle drug resistance in Leishmania infection. In vivo pharmacokinetic studies indicated that compound 19 has a long half-life (intravenous (IV): 63.2 h; per os (PO): 46.9 h) with an acceptable ADME-Toxicity profile. When tested in Leishmania infected hamsters, no toxicity and limited efficacy were observed. Low solubility and degradation were investigated spectroscopically as possible causes for the sub-optimal pharmacokinetic properties. Compound 19 resulted a specific compound based on the screening against a protein set, following the intrinsic fluorescence changes.


Assuntos
Antiprotozoários , Flavonóis , Leishmania/efeitos dos fármacos , Leishmaniose/tratamento farmacológico , Fosforilcolina/análogos & derivados , Tiofenos , Animais , Antiprotozoários/síntese química , Antiprotozoários/química , Antiprotozoários/farmacologia , Cricetinae , Avaliação Pré-Clínica de Medicamentos , Resistência a Medicamentos/efeitos dos fármacos , Flavonóis/síntese química , Flavonóis/química , Flavonóis/farmacologia , Genômica , Humanos , Fosforilcolina/química , Fosforilcolina/farmacologia , Tiofenos/síntese química , Tiofenos/química , Tiofenos/farmacologia
17.
Mol Carcinog ; 58(12): 2207-2217, 2019 12.
Artigo em Inglês | MEDLINE | ID: mdl-31544294

RESUMO

Recent evidence indicates that long noncoding RNA colon cancer-associated transcript-1 (lncRNA CCAT1) is abundantly expressed in esophageal cancer and is closely related to the occurrence, development, invasion, metastasis, and drug resistance of this disease. However, the role and molecular mechanisms of CCAT1 in the cell proliferation and chemoresistance of esophageal cancer are largely unknown. The correlation between CCAT1 expression and drug resistance to cisplatin (CDDP) in esophageal squamous cell carcinoma (ESCC) cells was analyzed using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-tetrazolium bromide (MTT) and quantitative real-time polymerase chain reaction (qRT-PCR) assays. CCAT1 knockdown and miR-143 overexpression or inhibition were used to verify the effects on proliferation and drug resistance via MTT, western blotting, flow cytometry, and immunofluorescence assays. qRT-PCR and western blotting were applied to detect the potential regulatory relationship among CCAT1, miR-143, PLK1, and BUBR1. A xenograft tumor assay was performed to validate the role of CCAT1 in vivo. The expression of CCAT1 was positively correlated with drug resistance in several ESCC cell lines. CCAT1 knockdown and miR-143 overexpression inhibited cell proliferation and CDDP drug resistance. Moreover, the downstream target of CCAT1 was found to be miR-143, which can regulate the expression of PLK1 and BUBR1. In vivo assays showed that CCAT1 knockdown suppressed tumor growth and enhanced the sensitivity of tumors to CDDP in nude mice. Taken together, we discovered a novel mechanism by which CCAT1 promotes cell proliferation and enhances drug resistance by regulating the miR-143/PLK1/BUBR1 signaling axis both in vitro and in vivo. Our findings further suggest that lncRNA CCAT1 may be a potential therapeutic target for overcoming chemoresistance in esophageal cancer.


Assuntos
Carcinoma de Células Escamosas/tratamento farmacológico , Proliferação de Células/efeitos dos fármacos , Cisplatino/farmacologia , Resistência a Medicamentos/efeitos dos fármacos , Neoplasias Esofágicas/tratamento farmacológico , MicroRNAs/genética , RNA Longo não Codificante/genética , Animais , Antineoplásicos/farmacologia , Biomarcadores Tumorais/genética , Carcinoma de Células Escamosas/genética , Carcinoma de Células Escamosas/metabolismo , Proteínas de Ciclo Celular/genética , Proteínas de Ciclo Celular/metabolismo , Linhagem Celular Tumoral , Proliferação de Células/genética , Resistência a Medicamentos/genética , Neoplasias Esofágicas/genética , Neoplasias Esofágicas/metabolismo , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Humanos , Masculino , Camundongos Endogâmicos BALB C , Camundongos Nus , MicroRNAs/metabolismo , Proteínas Serina-Treonina Quinases/genética , Proteínas Serina-Treonina Quinases/metabolismo , Proteínas Proto-Oncogênicas/genética , Proteínas Proto-Oncogênicas/metabolismo , Ensaios Antitumorais Modelo de Xenoenxerto/métodos
18.
Presse Med ; 48(12): 1431-1438, 2019 Dec.
Artigo em Francês | MEDLINE | ID: mdl-31473027

RESUMO

Resistant hypertension is defined as uncontrolled blood pressure (BP) despite three antihypertensive agents including a diuretic (thiazide diuretic if renal function is normal or loop diuretic in case of chronic kidney disease with eGFR<30mL/min), a renin-angiotensin system blocker (ARB or ACEI) and a calcium channel blocker, at optimal doses. Resistance must be confirmed by out-of-office measurements (ambulatory blood pressure monitoring or home blood pressure monitoring) and patients should be asked about treatment compliance and excessive salt or alcohol intake. If the diagnosis of resistant hypertension is confirmed, the patient should be referred to a hypertension specialist to screen for secondary causes of hypertension as they are frequent in this context. If essential resistant hypertension is confirmed, the mineralocorticoid receptor antagonist, spironolactone, should be added (25 to 50mg daily). In the event of a contraindication to spironolactone, or if adverse effects occur, a beta-blocker, an alpha-blocker, or a centrally acting antihypertensive drug should be prescribed.


Assuntos
Anti-Hipertensivos/uso terapêutico , Resistência a Medicamentos , Hipertensão Essencial/tratamento farmacológico , Espironolactona/uso terapêutico , Pressão Sanguínea/efeitos dos fármacos , Resistência a Medicamentos/efeitos dos fármacos , Quimioterapia Combinada , Hipertensão Essencial/epidemiologia , Humanos , Resultado do Tratamento
19.
Parasitol Res ; 118(10): 2877-2883, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31422463

RESUMO

Anthelmintic resistance in equine cyathostomin parasites is widespread. A surveillance-based parasite control program using fecal egg counts (FECs) and fecal egg count reduction tests (FECRTs) to decrease anthelmintic use and monitor treatment efficacy is recommended. The purpose of this study was to examine shifts in equine parasite control program management practices via a short course presented by the Penn State Extension, and to highlight how data collected from these programs is useful for monitoring anthelmintic efficacy on a large scale. Horse owners were enrolled after participating in a short course and filled out questionnaire surveys about their parasite management programs pre and post study, horse information, and farm information. FECs were performed at three time points, and horses above a 300 strongyle eggs per gram cut-off were treated with pyrantel pamoate, fenbendazole, or ivermectin. Two weeks post-treatment, FECRTs were performed to determine treatment efficacy, which included 29 farms with 513 individual treatments. Prior to the study, only 30.6% of farms used FECs, but after the study, 97.3% of farms said they would use FECs in the future. Horses were given an average of 4.1 anthelmintic treatments per year before the study, and post study 89.2% of farms were able to reduce the number of anthelmintic treatments used. Fenbendazole was effective on zero farms, pyrantel pamoate on 7.4% of farms, and ivermectin on 92.9% of farms. This outreach project helped generate information about anthelmintic efficacy levels, causing a shift in practices on participating farms, and collected useful anthelmintic resistance data.


Assuntos
Antinematódeos/uso terapêutico , Fenbendazol/uso terapêutico , Doenças dos Cavalos/epidemiologia , Ivermectina/uso terapêutico , Contagem de Ovos de Parasitas/veterinária , Pamoato de Pirantel/uso terapêutico , Animais , Resistência a Medicamentos/efeitos dos fármacos , Fazendas , Fezes/parasitologia , Doenças dos Cavalos/tratamento farmacológico , Doenças dos Cavalos/parasitologia , Cavalos , Inquéritos e Questionários
20.
Mem Inst Oswaldo Cruz ; 114: e190111, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31433006

RESUMO

BACKGROUND: In addition to the limited therapeutic arsenal and the side effects of antileishmanial agents, drug resistance hinders disease control. In Brazil, Leishmania braziliensis causes atypical (AT) tegumentary leishmaniasis lesions, frequently refractory to treatment. OBJECTIVES: The main goal of this study was to characterise antimony (Sb)-resistant (SbR) L. braziliensis strains obtained from patients living in Xakriabá indigenous community, Minas Gerais, Brazil. METHODS: The aquaglyceroporin 1-encoding gene (AQP1) from L. braziliensis clinical isolates was sequenced, and its function was evaluated by hypo-osmotic shock. mRNA levels of genes associated with Sb resistance were measured by quantitative reverse transcription polymerase chain reaction (qRT-PCR). Atomic absorption was used to measure Sb uptake. FINDINGS: Although clinical isolates presented delayed recovery time in hypo-osmotic shock, AQP1 function was maintained. Isolate 340 accumulated less Sb than all other isolates, supporting the 65-fold downregulation of AQP1 mRNA levels. Both 330 and 340 isolates upregulated antimony resistance marker (ARM) 56/ARM58 and multidrug resistant protein A (MRPA); however, only ARM58 upregulation was an exclusive feature of SbR field isolates. CA7AE seemed to increase drug uptake in L. braziliensis and represented a tool to study the role of glycoconjugates in Sb transport. MAIN CONCLUSIONS: There is a clear correlation between ARM56/58 upregulation and Sb resistance in AT-harbouring patients, suggesting the use of these markers as potential indicators to help the treatment choice and outcome, preventing therapeutic failure.


Assuntos
Antimônio/farmacologia , Resistência a Medicamentos/genética , Leishmania braziliensis/efeitos dos fármacos , Leishmaniose Cutânea/parasitologia , Proteínas de Protozoários/genética , Tripanossomicidas/farmacologia , Aquagliceroporinas/metabolismo , Resistência a Medicamentos/efeitos dos fármacos , Humanos , Leishmania braziliensis/genética , Testes de Sensibilidade Parasitária , Proteínas de Protozoários/metabolismo , Reação em Cadeia da Polimerase em Tempo Real
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA