Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 18 de 18
Filtrar
Más filtros










Intervalo de año de publicación
1.
Sci Rep ; 14(1): 10696, 2024 05 10.
Artículo en Inglés | MEDLINE | ID: mdl-38730068

RESUMEN

COVID-19, caused by SARS-CoV-2, affects neuronal cells, causing several symptoms such as memory loss, anosmia and brain inflammation. Curcuminoids (Me08 e Me23) and curcumin (CUR) are derived from Curcuma Longa extract (EXT). Many therapeutic actions have been linked to these compounds, including antiviral action. Given the severe implications of COVID-19, especially within the central nervous system, our study aims to shed light on the therapeutic potential of curcuminoids against SARS-CoV-2 infection, particularly in neuronal cells. Here, we investigated the effects of CUR, EXT, Me08 and Me23 in human neuroblastoma SH-SY5Y. We observed that Me23 significantly decreased the expression of plasma membrane-associated transmembrane protease serine 2 (TMPRSS2) and TMPRSS11D, consequently mitigating the elevated ROS levels induced by SARS-CoV-2. Furthermore, Me23 exhibited antioxidative properties by increasing NRF2 gene expression and restoring NQO1 activity following SARS-CoV-2 infection. Both Me08 and Me23 effectively reduced SARS-CoV-2 replication in SH-SY5Y cells overexpressing ACE2 (SH-ACE2). Additionally, all of these compounds demonstrated the ability to decrease proinflammatory cytokines such as IL-6, TNF-α, and IL-17, while Me08 specifically reduced INF-γ levels. Our findings suggest that curcuminoid Me23 could serve as a potential agent for mitigating the impact of COVID-19, particularly within the context of central nervous system involvement.


Asunto(s)
Antiinflamatorios , Antioxidantes , Antivirales , Tratamiento Farmacológico de COVID-19 , Curcumina , SARS-CoV-2 , Humanos , Curcumina/farmacología , Curcumina/análogos & derivados , Antioxidantes/farmacología , Antivirales/farmacología , SARS-CoV-2/efectos de los fármacos , SARS-CoV-2/fisiología , Antiinflamatorios/farmacología , Línea Celular Tumoral , Curcuma/química , Serina Endopeptidasas/metabolismo , COVID-19/virología , COVID-19/metabolismo , Especies Reactivas de Oxígeno/metabolismo , Factor 2 Relacionado con NF-E2/metabolismo , Extractos Vegetales/farmacología , Citocinas/metabolismo , NAD(P)H Deshidrogenasa (Quinona)/metabolismo , Neuronas/efectos de los fármacos , Neuronas/metabolismo , Neuronas/virología
2.
J Med Virol ; 96(2): e29416, 2024 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-38285457

RESUMEN

The raising of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) variants led to the use of COVID-19 bivalent vaccines, which include antigens of the wild-type (WT) virus, and of the Omicron strain. In this study, we aimed to evaluate the impact of bivalent vaccination on the neutralizing antibody (NAb) response. We enrolled 93 volunteers who had received three or four doses of monovalent vaccines based on the original virus (n = 61), or a booster shot with the bivalent vaccine (n = 32). Serum samples collected from volunteers were subjected to neutralization assays using the WT SARS-CoV-2, and Omicron subvariants. In addition, immunoinformatics to quantify and localize highly conserved NAb epitopes were performed. As main result, we observed that the neutralization titers of samples from individuals vaccinated with the bivalent vaccine were higher for the original virus, in comparison to their capacity of neutralizing the Omicron variant and its subvariants. NAb that recognize epitopes mostly conserved in the WT SARS-CoV-2 were boosted, while those that recognize epitopes mostly present in the Omicron variant, and subvariants were primed. These results indicate that formulation of future vaccines shall consider to target present viruses, and not viruses that no longer circulate.


Asunto(s)
Vacunas contra la COVID-19 , COVID-19 , Humanos , COVID-19/prevención & control , SARS-CoV-2/genética , Vacunación , Inmunización Secundaria , Anticuerpos Neutralizantes , Epítopos/genética , Vacunas Combinadas
3.
J Allergy Clin Immunol Glob ; 2(2): 100083, 2023 May.
Artículo en Inglés | MEDLINE | ID: mdl-36845213

RESUMEN

Background: The pandemic unleashed by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has infected more than 500 million people worldwide and caused more than 6 million deaths. Cellular and humoral immunity induced by infection or immunization are key factors in controlling the viral burden and avoiding the recurrence of coronavirus disease. The duration and effectiveness of immunity after infection is relevant to pandemic policy interventions, including the timing of vaccine boosters. Objectives: We sought to evaluate longitudinal binding and functional antibodies against SARS-CoV-2 receptor-binding domain in police officers and health care workers with a history of coronavirus disease 2019 and compare with SARS-CoV-2-naive individuals after vaccination with adenovirus-based ChAdOx1 nCoV-19 (AstraZeneca-Fiocruz) or the inactivated CoronaVac vaccine (Sinovac-Butantan Institute). Methods: A total of 208 participants were vaccinated. Of these, 126 (60.57%) received the ChAdOx1 nCoV-19 vaccine and 82 (39.42%) received the CoronaVac vaccine. Prevaccination and postvaccination blood was collected, and the amount of anti-SARS-CoV-2 IgG and the neutralizing ability of the antibodies to block the interaction between angiotensin-converting enzyme 2 and receptor-binding domain were determined. Results: Subjects with preexisting SARS-CoV-2 immunity and who received a single dose of ChAdOx1 nCoV-19 or CoronaVac have similar or superior antibody levels when compared with levels in seronegative individuals even after 2 doses of the vaccine. Neutralizing antibody titers of seropositive individuals were higher with a single dose of either ChAdOx1 nCoV-19 or CoronaVac compared with those of seronegative individuals. After 2 doses, both groups reached a plateau response. Conclusions: Our data reinforce the importance of vaccine boosters to increase specific binding and neutralizing SARS-CoV-2 antibodies.

4.
J Nanostructure Chem ; 13(2): 263-281, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-35251554

RESUMEN

The outbreak of coronavirus (COVID-19) has put the world in an unprecedented scenario. To reestablish the world routine as promote the effective treatment of this disease, the world is looking for new (and old) drug that can efficiently kill the virus. In this study, we have developed two nanosystems: polymeric nanoparticles and nanomicelles-based on hydroxychloroquine and azithromycin. The nanosystem was fully characterized by AFM and DLS techniques. Also, the nanosystems were radiolabeled with 99mTc and pulmonary applied (installation) in vivo to evaluate the biological behavior. The toxicity of both nanosystem were evaluated in primary cells (FGH). Finally, both nanosystems were evaluated in vitro against the SARS-CoV-2. The results demonstrated that the methodology used to produce the nanomicelles and the nanoparticle was efficient, the characterization showed a nanoparticle with a spherical shape and a medium size of 390 nm and a nanomicelle also with a spherical shape and a medium size of 602 nm. The nanomicelles were more efficient (~ 70%) against SARS-CoV-2 than the nanoparticles. The radiolabeling process with 99mTc was efficient (> 95%) in both nanosystems and the pulmonary application demonstrated to be a viable route for both nanosystems with a local retention time of approximately, 24 h. None of the nanosystems showed cytotoxic effect on FGH cells, even in high doses, corroborating the safety of both nanosystems. Thus, claiming the benefits of the nanotechnology, especially with regard the reduced adverse we believe that the use of nanosystems for COVID-19 treatment can be an optimized choice. Supplementary Information: The online version contains supplementary material available at 10.1007/s40097-022-00476-3.

5.
J Water Health ; 20(2): 471-490, 2022 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-36366999

RESUMEN

The current COVID-19 pandemic has emphasized the vulnerability of communities living in the urban outskirts and informal settlements. The lack of reliable COVID-19 case data highlights the importance and application of wastewater-based epidemiology. This study aimed to monitor the COVID-19 trends in four vulnerable urban communities (slums and low-income neighborhoods) in metropolitan São Paulo by assessing the SARS-CoV-2 RNA viral load in wastewater. We analyzed 160 samples from May 2020 to June 2021 with weekly or fortnightly samplings. The samples were ultracentrifuged with glycine elution and quantified by N1/N2 SARS-CoV-2 RT-qPCR. The results of positivity were 100% (Paraisópolis, Heliópolis and Cidade Tiradentes) and 76.9% (Vila Brasilândia). The new case numbers of COVID-19, counted from the onset of symptoms, positively correlated with SARS-CoV-2 N1 viral loads from the two largest communities (p<0.001). SARS-CoV-2 infectivity was tested in Vero E6 cells after concentration with the two techniques, ultrafiltration (Centricon® Plus-70 10 kDa) and sucrose cushion ultracentrifugation, but none of the evaluated samples presented positive results. Next-generation sequencing (NGS) analysis from samples collected in March and August 2021 revealed the presence of the clade 20 J (lineage P.1) belonging to the most prevalent circulating variant in the country. Our results showed that wastewater surveillance data can be used as complementary indicators to monitor the dynamics and temporal trends of COVID-19. The infectivity test results strengthened the evidence of low risk of infection associated with SARS-CoV-2 in wastewater.


Asunto(s)
COVID-19 , SARS-CoV-2 , Humanos , Aguas Residuales , Pandemias , COVID-19/epidemiología , ARN Viral , Brasil/epidemiología , Monitoreo Epidemiológico Basado en Aguas Residuales
6.
Eur J Pharm Biopharm ; 180: 91-100, 2022 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-36154904

RESUMEN

The use of graphene quantum dots as biomedical devices and drug delivery systems has been increasing. The nano-platform of pure carbon has shown unique properties and is approved to be safe for human use. In this study, we successfully produced and characterized folic acid-functionalized graphene quantum dots (GQD-FA) to evaluate their antiviral activity against Zika virus (ZIKV) infection in vitro, and for radiolabeling with the alpha-particle emitting radionuclide radium-223. The in vitro results exhibited the low cytotoxicity of the nanoprobe GQD-FA in Vero E6 cells and the antiviral effect against replication of the ZIKV infection. In addition, our findings demonstrated that functionalization with folic acid doesn't improve the antiviral effect of graphene quantum dots against ZIVK replication in vitro. On the other hand, the radiolabeled nanoprobe 223Ra@GQD-FA was also produced as confirmed by the Energy Dispersive X-Ray Spectroscopy analysis. 223Ra@GQD-FA might expand the application of alpha targeted therapy using radium-223 in folate receptor-overexpressing tumors.


Asunto(s)
Grafito , Puntos Cuánticos , Infección por el Virus Zika , Virus Zika , Humanos , Puntos Cuánticos/química , Grafito/química , Ácido Fólico/química , Antivirales/farmacología
7.
Life Sci ; 308: 120930, 2022 Nov 01.
Artículo en Inglés | MEDLINE | ID: mdl-36075471

RESUMEN

AIMS: This study evaluated SARS-CoV-2 replication in human cell lines derived from various tissues and investigated molecular mechanisms related to viral infection susceptibility and replication. MAIN METHODS: SARS-CoV-2 replication in BEAS-2B and A549 (respiratory tract), HEK-293 T (kidney), HuH7 (liver), SH-SY5Y (brain), MCF7 (breast), Huvec (endothelial) and Caco-2 (intestine) was evaluated by RT-qPCR. Concomitantly, expression levels of ACE2 (Angiotensin Converting Enzyme) and TMPRSS2 were assessed through RT-qPCR and western blot. Proteins related to autophagy and mitochondrial metabolism were monitored in uninfected cells to characterize the cellular metabolism of each cell line. The effect of ACE2 overexpression on viral replication in pulmonary cells was also investigated. KEY FINDINGS: Our data show that HuH7, Caco-2 and MCF7 presented a higher viral load compared to the other cell lines. The increased susceptibility to SARS-CoV-2 infection seems to be associated not only with the differential levels of proteins intrinsically related to energetic metabolism, such as ATP synthase, citrate synthase, COX and NDUFS2 but also with the considerably higher TMPRSS2 mRNA expression. The two least susceptible cell types, BEAS-2B and A549, showed drastically increased SARS-CoV-2 replication capacity when ACE2 was overexpressed. These modified cell lines are relevant for studying SARS-CoV-2 replication in vitro. SIGNIFICANCE: Our data not only reinforce that TMPRSS2 expression and cellular energy metabolism are important molecular mechanisms for SARS-CoV-2 infection and replication, but also indicate that HuH7, MCF7 and Caco-2 are suitable models for mechanistic studies of COVID-19. Moreover, pulmonary cells overexpressing ACE2 can be used to understand mechanisms associated with SARS-CoV-2 replication.


Asunto(s)
COVID-19 , Neuroblastoma , Adenosina Trifosfato , Enzima Convertidora de Angiotensina 2/genética , Autofagia , Células CACO-2 , Citrato (si)-Sintasa , Células HEK293 , Humanos , Peptidil-Dipeptidasa A/metabolismo , ARN Mensajero/genética , SARS-CoV-2
8.
J Immunol Res ; 2021: 2939693, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-34604391

RESUMEN

All extracellular forms of Trypanosoma cruzi, the causative agent of Chagas disease, release extracellular vesicles (EVs) containing major surface molecules of the parasite. EV release depends on several mechanisms (internal and external). However, most of the environmental conditions affecting this phenomenon are still unknown. In this work, we evaluated EV release under different stress conditions and their ability to be internalized by the parasites. In addition, we investigated whether the release conditions would affect their immunomodulatory properties in preactivated bone marrow-derived macrophages (BMDM). Sodium azide and methyl-cyclo-ß-dextrin (CDB) reduced EV release, indicating that this phenomenon relies on membrane organization. EV release was increased at low temperatures (4°C) and acidic conditions (pH 5.0). Under this pH, trypomastigotes differentiated into amastigotes. EVs are rapidly liberated and reabsorbed by the trypomastigotes in a concentration-dependent manner. Nitrosative stress caused by sodium nitrite in acid medium or S-nitrosoglutathione also stimulated the secretion of EVs. EVs released under all stress conditions also maintained their proinflammatory activity and increased the expression of iNOS, Arg 1, IL-12, and IL-23 genes in IFN-γ and LPS preactivated BMDM. In conclusion, our results suggest a budding mechanism of release, dependent on the membrane structure and parasite integrity. Stress conditions did not affect functional properties of EVs during interaction with host cells. EV release variations under stress conditions may be a physiological response against environmental changes.


Asunto(s)
Vesículas Extracelulares/inmunología , Macrófagos/inmunología , Estrés Fisiológico/inmunología , Trypanosoma cruzi/inmunología , Animales , Línea Celular , Células Cultivadas , Frío , Vesículas Extracelulares/metabolismo , Femenino , Regulación de la Expresión Génica/inmunología , Concentración de Iones de Hidrógeno , Inmunidad/genética , Inmunidad/inmunología , Interleucina-10/genética , Interleucina-10/inmunología , Interleucina-10/metabolismo , Macrófagos/metabolismo , Ratones Endogámicos C57BL , Óxido Nítrico Sintasa de Tipo II/genética , Óxido Nítrico Sintasa de Tipo II/inmunología , Óxido Nítrico Sintasa de Tipo II/metabolismo , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Nitrito de Sodio/metabolismo , Trypanosoma cruzi/metabolismo , Trypanosoma cruzi/fisiología
9.
Biomed J ; 44(1): 31-42, 2021 03.
Artículo en Inglés | MEDLINE | ID: mdl-33602633

RESUMEN

The pandemic caused by Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) is receiving worldwide attention, due to the severity of the disease (COVID-19) that resulted in more than a million global deaths so far. The urgent need for vaccines and antiviral drugs is mobilizing the scientific community to develop strategies for studying the mechanisms of SARS-CoV-2 infection, replication kinetics, pathogenesis, host-virus interaction, and infection inhibition. In this work, we review the strategies of tissue engineering in the fabrication of three-dimensional (3D) models used in virology studies, which presented many advantages over conventional cell cultures, such as complex cytoarchitecture and a more physiological microenvironment. Scaffold-free (spheroids and organoids) and scaffold-based (3D scaffolding and 3D bioprinting) approach allow the biofabrication of more realistic models relevant to the pandemic, to be used as in vitro platforms for the development of new vaccines and therapies against COVID-19.


Asunto(s)
Bioimpresión , SARS-CoV-2/patogenicidad , Esferoides Celulares , Ingeniería de Tejidos/métodos , Enzima Convertidora de Angiotensina 2/fisiología , Animales , Antivirales/farmacología , Humanos , Organoides , SARS-CoV-2/efectos de los fármacos , Andamios del Tejido
10.
Cell Rep ; 28(12): 3120-3130.e5, 2019 Sep 17.
Artículo en Inglés | MEDLINE | ID: mdl-31533035

RESUMEN

Noradrenaline (NE), the main neurotransmitter released by sympathetic nerve terminals, is known to modulate the immune response. However, the role of the sympathetic nervous system (SNS) on the development of autoimmune diseases is still unclear. Here, we report that the SNS limits the generation of pathogenic T cells and disease development in the experimental autoimmune encephalomyelitis (EAE) model of multiple sclerosis (MS). ß2-Adrenergic receptor (Adrb2) signaling limits T cell autoimmunity in EAE through a mechanism mediated by the suppression of IL-2, IFN-γ, and GM-CSF production via inducible cAMP early repressor (ICER). Accordingly, the lack of Adrb2 signaling in immune cells is sufficient to abrogate the suppressive effects of SNS activity, resulting in increased pathogenic T cell responses and EAE development. Collectively, these results uncover a suppressive role for the SNS in CNS autoimmunity while they identify potential targets for therapeutic intervention.


Asunto(s)
Encefalomielitis Autoinmune Experimental/inmunología , Inmunidad Celular , Esclerosis Múltiple/inmunología , Receptores Adrenérgicos beta 2/inmunología , Transducción de Señal/inmunología , Sistema Nervioso Simpático/inmunología , Linfocitos T/inmunología , Animales , Citocinas/genética , Citocinas/inmunología , Encefalomielitis Autoinmune Experimental/patología , Ratones , Ratones Noqueados , Esclerosis Múltiple/genética , Esclerosis Múltiple/patología , Receptores Adrenérgicos beta 2/genética , Transducción de Señal/genética , Sistema Nervioso Simpático/patología , Linfocitos T/patología
11.
J Leukoc Biol ; 106(3): 581-594, 2019 09.
Artículo en Inglés | MEDLINE | ID: mdl-31299112

RESUMEN

Chronic lymphocytic leukemia (CLL) is a chronic form of leukemia that originates from an abnormal expansion of CD5+ B-1 cells. Deregulation in the BCR signaling is associated with B-cell transformation. Contrariwise to B-2 cells, BCR engagement in B-1 cells results in low proliferation rate and increased apoptosis population, whereas overactivation may be associated with lymphoproliferative disorders. It has been demonstrated that several transcription factors that are involved in the B cell development play a role in the regulation of BCR function. Among them, Ikaros is considered an essential regulator of lymphoid differentiation and activation. Several reports suggest that Ikaros expression is deregulated in different forms of leukemia. Herein, we demonstrated that CLL cells show decreased Ikaros expression and abnormal cytoplasmic cell localization. These alterations were also observed in radioresistant B-1 cells, which present high proliferative activity, suggesting that abnormal localization of Ikaros could determine its loss of function. Furthermore, Ikaros knockdown increased the expression of BCR pathway components in murine B-1 cells, such as Lyn, Blnk, and CD19. Additionally, in the absence of Ikaros, B-1 cells become responsive to BCR stimulus, increasing cell proliferation even in the absence of antigen stimulation. These results suggested that Ikaros is an important controller of B-1 cell proliferation by interfering with the BCR activity. Therefore, altered Ikaros expression in CLL or radioresistant B-1 cells could determine a responsive status of BCR to self-antigens, which would culminate in the clonal expansion of B-1 cells.


Asunto(s)
Transformación Celular Neoplásica/genética , Regulación Leucémica de la Expresión Génica , Factor de Transcripción Ikaros/genética , Leucemia Linfocítica Crónica de Células B/genética , Adulto , Anciano , Anciano de 80 o más Años , Animales , Linfocitos B/inmunología , Transformación Celular Neoplásica/patología , Citoplasma/metabolismo , Femenino , Humanos , Factor de Transcripción Ikaros/metabolismo , Leucemia Linfocítica Crónica de Células B/patología , Masculino , Ratones , Ratones Endogámicos C57BL , Persona de Mediana Edad , Modelos Biológicos , Unión Proteica , Tolerancia a Radiación , Receptores de Antígenos de Linfocitos B/metabolismo , Transducción de Señal
12.
J Immunol ; 196(2): 637-44, 2016 Jan 15.
Artículo en Inglés | MEDLINE | ID: mdl-26663782

RESUMEN

Despite accumulating evidence indicating that neurotransmitters released by the sympathetic nervous system can modulate the activity of innate immune cells, we still know very little about how norepinephrine impacts signaling pathways in dendritic cells (DC) and the consequence of that in DC-driven T cell differentiation. In this article, we demonstrate that ß2-adrenergic receptor (ß2AR) activation in LPS-stimulated DC does not impair their ability to promote T cell proliferation; however, it diminishes IL-12p70 secretion, leading to a shift in the IL-12p70/IL-23 ratio. Although ß2AR stimulation in DC induces protein kinase A-dependent cAMP-responsive element-binding protein phosphorylation, the effect of changing the profile of cytokines produced upon LPS challenge occurs in a protein kinase A-independent manner and, rather, is associated with inhibition of the NF-κB and AP-1 signaling pathways. Moreover, as a consequence of the inverted IL-12p70/IL-23 ratio following ß2AR stimulation, LPS-stimulated DC promoted the generation of CD4(+) T cells that, upon TCR engagement, produced lower amounts of IFN-γ and higher levels of IL-17. These findings provide new insights into molecular and cellular mechanisms by which ß2AR stimulation in murine DC can influence the generation of adaptive immune responses and may explain some aspects of how sympathetic nervous system activity can modulate immune function.


Asunto(s)
Linfocitos T CD4-Positivos/inmunología , Células Dendríticas/inmunología , Norepinefrina/inmunología , Receptores Adrenérgicos beta 2/inmunología , Transducción de Señal/inmunología , Animales , Western Blotting , Diferenciación Celular/inmunología , Ensayo de Inmunoadsorción Enzimática , Femenino , Citometría de Flujo , Activación de Linfocitos/inmunología , Ratones , Ratones Endogámicos C57BL , FN-kappa B/inmunología , Reacción en Cadena en Tiempo Real de la Polimerasa , Factor de Transcripción AP-1/inmunología
13.
AIDS Res Hum Retroviruses ; 30(9): 867-80, 2014 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-25065371

RESUMEN

Hypermutation alludes to an excessive number of specific guanine-to-adenine (G- >A) substitutions in proviral DNA and this phenomenon is attributed to the catalytic activity of cellular APOBECs. Population studies relating hypermutation and the progression of infection by human immunodeficiency virus type 1 (HIV-1) have been performed to elucidate the effect of hypermutation on the natural course of HIV-1 infection. However, the many different approaches employed to assess hypermutation in nucleotide sequences render the comparison of results difficult. This study selected 157 treatment-naive patients and sought to correlate the hypermutation level of the proviral sequences in clinical samples with demographic variables, HIV-1 RNA viral load, and the level of CD4(+) T cells. Nested touchdown polymerase chain reaction (PCR) was performed with specific primers to detect hypermutation in the region of HIV-1 integrase, and the amplified sequences were run in agarose gels with HA-Yellow. The analysis of gel migration patterns using the k-means clustering method was validated by its agreement with the results obtained with the software Hypermut. Hypermutation was found in 31.2% of the investigated samples, and a correlation was observed between higher hypermutation levels and higher viral load levels. These findings suggest a high frequency of hypermutation detection in a Brazilian cohort, which can reflect a particular characteristic of this population, but also can result from the method approach by aiming at hypermutation-sensitive sites. Furthermore, we found that hypermutation events are pervasive during HIV-1 infection as a consequence of high viral replication, reflecting its role during disease progression.


Asunto(s)
Fármacos Anti-VIH/uso terapéutico , Infecciones por VIH/tratamiento farmacológico , Infecciones por VIH/virología , VIH-1/genética , Mutación , Carga Viral , Secuencia de Bases , Brasil , Cartilla de ADN , Humanos , Reacción en Cadena de la Polimerasa
14.
PLoS One ; 9(1): e84066, 2014.
Artículo en Inglés | MEDLINE | ID: mdl-24404149

RESUMEN

The present study investigated the prevalence of HIV-1 multiple infections in a population composed by 47 patients under HAART failure and enrolled at the National DST/AIDS, Program, Ministry of Health, Brazil.Detection of multiple infections was done using a previously published RFLP assay for the HIV-1 protease gene, which is able of distinguishing between infections caused by a single or multiple HIV-1 subtypes. Samples with multiple infections were cloned, and sequence data submitted to phylogenetic analysis. We were able to identify 17 HIV-1 multiple infections out of 47 samples. Multiple infections were mostly composed by a mixture of recombinant viruses (94%), with only one case in which protease gene pure subtypes B and F were recovered. This is the first study that reports the prevalence of multiple infections and intersubtype recombinants in a population undergoing HAART in Brazil. Based on the data there was a steep increase of multiple infections after the introduction of the combined antiretroviral therapy in Brazil. Cases of multiple infections may be associated with HIV-1 genetic diversity through recombination allowing for the generation of viruses showing a combination of resistance mutations.


Asunto(s)
Infecciones por VIH/virología , Proteasa del VIH/genética , VIH-1/genética , Recombinación Genética , Fármacos Anti-VIH/farmacología , Brasil , Farmacorresistencia Viral , Genotipo , Infecciones por VIH/epidemiología , VIH-1/clasificación , Humanos , Datos de Secuencia Molecular , Filogenia , Virus Reordenados/clasificación , Virus Reordenados/genética
15.
PLoS One ; 8(7): e69590, 2013.
Artículo en Inglés | MEDLINE | ID: mdl-23922749

RESUMEN

Paracoccidioides brasiliensis, a causative agent of paracoccidioidomycosis (PCM), should be able to adapt to dramatic environmental changes inside the infected host after inhalation of air-borne conidia and transition to pathogenic yeasts. Proteins with antioxidant functions may protect fungal cells against reactive oxygen (ROS) and nitrogen (RNS) species generated by phagocytic cells, thus acting as potential virulence factors. Ras GTPases are involved in stress responses, cell morphology, and differentiation in a range of organisms. Ras, in its activated form, interacts with effector proteins and can initiate a kinase cascade. In lower eukaryotes, Byr2 kinase represents a Ras target. The present study investigated the role of Ras in P. brasiliensis after in vitro stimulus with ROS or RNS. We have demonstrated that low concentrations of H2O2 (0.1 mM) or NO2 (0.1-0.25 µM) stimulated P. brasiliensis yeast cell proliferation and that was not observed when yeast cells were pre-incubated with farnesyltransferase inhibitor. We constructed an expression plasmid containing the Byr2 Ras-binding domain (RBD) fused with GST (RBD-Byr2-GST) to detect the Ras active form. After stimulation with low concentrations of H2O2 or NO2, the Ras active form was observed in fungal extracts. Besides, NO2 induced a rapid increase in S-nitrosylated Ras levels. This alternative posttranslational modification of Ras, probably in residue Cys123, would lead to an exchange of GDP for GTP and consequent GTPase activation in P. brasiliensis. In conclusion, low concentrations of H2O2 or NO2 stimulated P. brasiliensis proliferation through Ras activation.


Asunto(s)
Peróxido de Hidrógeno/farmacología , Nitritos/farmacología , Paracoccidioides/citología , Paracoccidioides/metabolismo , Proteínas ras/metabolismo , Proliferación Celular/efectos de los fármacos , Paracoccidioides/efectos de los fármacos , Proteínas ras/genética
16.
Arq Bras Oftalmol ; 74(5): 338-42, 2011.
Artículo en Portugués | MEDLINE | ID: mdl-22183993

RESUMEN

PURPOSE: To evaluate the comparative in-vitro antiangiogenic effect of Bevacizumab and Ranibizumab. METHODS: Endothelial venous umbilical cells culture (ECV304) cultivated in F12 media with addition of 10% Fetal Bovine Serum, were plaqued and treated with clinically relevant concentrations of Bevacizumab and Ranibizumab just after the scratch done in the middle of the culture (scratch methodology). Measurements of the linear size of the area free of cell proliferation were done 24, 48 and 72 hours after the scratch day point. All the experiments were done in triplicate and statistical analysis were done with T-student test. RESULTS: Inhibitory effect was observed just at the concentrations of 0.5 and 0.7 mg/ml in both drugs. At 0.7 mg/ml, Ranibizumab demonstrated a more potent proliferative inhibitory effect than Bevacizumab. At the same concentration, Ranibizumab was three times more potent than Ranibizumab. Inhibitory effect was observed just in the first 24 hours for both drugs. CONCLUSION: Ranibizumab demonstrates an increased effect when compared to Bevacizumab and this is related more to the different molar rate of each drug than related to a real better proliferative inhibitory effect.


Asunto(s)
Inhibidores de la Angiogénesis/farmacología , Anticuerpos Monoclonales Humanizados/farmacología , Proliferación Celular/efectos de los fármacos , Células Endoteliales de la Vena Umbilical Humana/efectos de los fármacos , Bevacizumab , Células Cultivadas , Humanos , Ranibizumab , Factores de Tiempo
17.
Arq. bras. oftalmol ; 74(5): 338-342, set.-out. 2011. ilus
Artículo en Portugués | LILACS | ID: lil-608405

RESUMEN

Objetivo: Comparar o efeito anti-angiogênico in vitro do Bevacizumab e do Rani bizumab. Métodos: Células endotelias venosas de cordão umbilical (ECV304), cultivadas em meio F12 com adição de 10 por cento de soro fetal bovino, foram plaqueadas e tratadas com concentrações clinicamente relevantes de Bevacizumab e Ranibizumab. As drogas foram administradas logo após risco realizado no meio da cultura (metodologia de scratch). Medidas lineares do espaço livre de proliferação celular foram realizadas 24, 48 e 72 horas após o momento da realização do risco. Todos os experimentos foram realizados em triplicata e a análise estatística foi feita pelo teste T-student. Resultados: O efeito inibitório foi observado em ambas as drogas, apenas nas concentrações 0,5 e 0,7 mg/ml. Na concentração 0,7 mg/ml, o Ranibizumab demonstrou efeito inibitório maior do que o Bevacizumab. Na mesma concentração, o Ranibizumab foi três vezes mais potente que o Bevacizumab. O efeito inibitório foi observado apenas nas primeiras 24 horas para ambas as drogas. Conclusão: O Ranibizumab demonstrou efeito maior quando comparado com o Bevacizumab, porém tal efeito está mais relacionado à diferença na razão molar das drogas do que relacionada com uma diferença real no efeito anti-proliferativo.


Purpose: To evaluate the comparative in-vitro antiangiogenic effect of Bevacizumab and Ranibizumab. Methods: Endothelial venous umbilical cells culture (ECV304) cultivated in F12 media with addition of 10 percent Fetal Bovine Serum, were plaqued and treated with clinically relevant concentrations of Bevacizumab and Ranibizumab just after the scratch done in the middle of the culture (scratch methodology). Measurements of the linear size of the area free of cell proliferation were done 24, 48 and 72 hours after the scratch day point. All the experiments were done in triplicate and statistical analysis were done with T-student test. Results: Inhibitory effect was observed just at the concentrations of 0.5 and 0.7 mg/ml in both drugs. At 0.7 mg/ml, Ranibizumab demonstrated a more potent proliferative inhibitory effect than Bevacizumab. At the same concentration, Ranibizumab was three times more potent than Ranibizumab. Inhibitory effect was observed just in the first 24 hours for both drugs. Conclusion: Ranibizumab demonstrates an increased effect when compared to Bevacizumab and this is related more to the different molar rate of each drug than related to a real better proliferative inhibitory effect.


Asunto(s)
Humanos , Inhibidores de la Angiogénesis/farmacología , Anticuerpos Monoclonales Humanizados/farmacología , Proliferación Celular/efectos de los fármacos , Células Endoteliales de la Vena Umbilical Humana/efectos de los fármacos , Células Cultivadas , Factores de Tiempo
18.
Microbes Infect ; 13(3): 251-60, 2011 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-21070862

RESUMEN

This work was conducted to identify virulence biomarkers for Paracoccidioides brasiliensis (Pb), the fungus responsible for Paracoccidioidomycosis (PCM), a systemic disease endemic in Latin America. Measurement of mortality showed that all B10.A mice were killed after 250 days by the virulent Pb18 isolate while only one of the mice that received the attenuated counterpart died. Also, number of lung CFUs from virulent Pb18 inoculated mice were much higher when these isolates were compared. Phage display methodology allowed selection of three phages that specifically bound to virulent Pb18. Variability of p04 phage binding to different Pb isolates were examples of variability of expression by the fungus of its binding molecule, strongly suggesting p04 as a biomarker of virulence. In vitro, its derived peptide pep04 killed only virulent fungi, and confocal microscopy showed that it was internalized only by the virulent isolate. Pep04 blocked establishment of Pb infection in mice and virulent Pb18 pre-incubated with p04 showed significantly inhibited lung infection. Furthermore, infected mice treated with p04 showed highly significant reduction in lung CFUs. These findings firmly establish p04 as a biomarker of Pb virulence. Therefore, after proper peptide engineering, p04 may become a useful adjuvant for the distressing treatment of PCM.


Asunto(s)
Antifúngicos/farmacología , Paracoccidioides/efectos de los fármacos , Péptidos/farmacología , Análisis de Varianza , Animales , Antifúngicos/metabolismo , Biomarcadores/análisis , Biomarcadores/metabolismo , Recuento de Colonia Microbiana , Histocitoquímica , Hígado/microbiología , Pulmón/microbiología , Masculino , Ratones , Microscopía Fluorescente , Paracoccidioides/metabolismo , Biblioteca de Péptidos , Péptidos/metabolismo , Reproducibilidad de los Resultados , Bazo/microbiología , Virulencia
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA
...