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1.
Appl Microbiol Biotechnol ; 107(11): 3495-3508, 2023 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-37126083

RESUMEN

Due to the high number of doses required to achieve adequate coverage in the context of COVID-19 pandemics, there is a great need for novel vaccine developments. In this field, there have been research approaches that focused on the production of SARS-CoV-2 virus-like particles. These are promising vaccine candidates as their structure is similar to that of native virions but they lack the genome, constituting a biosafe alternative. In order to produce these structures using mammal cells, it has been established that all four structural proteins must be expressed. Here we report the generation and characterization of a novel chimeric virus-like particle (VLP) that can be produced by the expression of a single novel fusion protein that contains SARS-CoV-2 spike (S) ectodomain fused to rabies glycoprotein membrane anchoring region in HEK293 cells. This protein is structurally similar to native S and can autonomously bud forming enveloped VLPs that resemble native virions both in size and in morphology, displaying S ectodomain and receptor binding domain (RBD) on their surface. As a proof of concept, we analyzed the immunogenicity of this vaccine candidate in mice and confirmed the generation of anti-S, anti-RBD, and neutralizing antibodies. KEY POINTS: • A novel fusion rabies glycoprotein containing S ectodomain was designed. • Fusion protein formed cVLPs that were morphologically similar to SARS-CoV-2 virions. • cVLPs induced anti-S, anti-RBD, and neutralizing antibodies in mice.


Asunto(s)
COVID-19 , Rabia , Vacunas Virales , Animales , Ratones , Humanos , SARS-CoV-2/genética , COVID-19/prevención & control , Anticuerpos Antivirales , Células HEK293 , Anticuerpos Neutralizantes , Glicoproteína de la Espiga del Coronavirus/genética , Mamíferos
2.
Appl Microbiol Biotechnol ; 107(11): 3429-3441, 2023 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-37093307

RESUMEN

Spike protein from SARS-CoV-2, the etiologic agent of the COVID-19 pandemic disease, constitutes a structural protein that proved to be the main responsible for neutralizing antibody production. Thus, its sequence is highly considered for the design of candidate vaccines. Animal cell culture represents the best option for the production of subunit vaccines based on recombinant proteins since they introduce post-translational modifications that are important to mimic the natural antigenic epitopes. Particularly, the human cell line HEK293T has been explored and used for the production of biotherapeutics since the products derived from them present human-like post-translational modifications that are important for the protein's activity and immunogenicity. The aim of this study was to produce and characterize a potential vaccine for COVID-19 based on the spike ectodomain (S-ED) of SARS-CoV-2 and two different adjuvants: aluminum hydroxide (AH) and immune-stimulating complexes (ISCOMs). The S-ED was produced in sHEK293T cells using a 1-L stirred tank bioreactor operated in perfusion mode and purified. S-ED characterization revealed the expected size and morphology. High N-glycan content was confirmed. S-ED-specific binding with the hACE2 (human angiotensin-converting enzyme 2) receptor was verified. The immunogenicity of S-ED was evaluated using AH and ISCOMs. Both formulations demonstrated the presence of anti-RBD antibodies in the plasma of immunized mice, being significantly higher for the latter adjuvant. Also, higher levels of IFN-γ and IL-4 were detected after the ex vivo immune stimulation of spleen-derived MNCs from ISCOMs immunized mice. Further analysis confirmed that S-ED/ISCOMs elicit neutralizing antibodies against SARS-CoV-2. KEY POINTS: Trimeric SARS-CoV-2 S-ED was produced in stable recombinant sHEK cells in serum-free medium. A novel S-ED vaccine formulation induced potent humoral and cellular immunity. S-ED formulated with ISCOMs adjuvant elicited a highly neutralizing antibody titer.


Asunto(s)
COVID-19 , ISCOMs , Humanos , Ratones , Animales , Vacunas contra la COVID-19 , Glicoproteína de la Espiga del Coronavirus/genética , COVID-19/prevención & control , SARS-CoV-2 , Complejo Antígeno-Anticuerpo , Pandemias/prevención & control , Células HEK293 , Anticuerpos Antivirales , Anticuerpos Neutralizantes , Adyuvantes Inmunológicos , Hidróxido de Aluminio
3.
Bioorg Med Chem Lett ; 29(2): 262-266, 2019 01 15.
Artículo en Inglés | MEDLINE | ID: mdl-30501966

RESUMEN

Bovine viral diarrhea virus (BVDV) is a pestivirus whose infection in cattle is globally distributed. The use of antivirals could complement vaccination as a tool of control and reduce economic losses. The RNA-dependent RNA polymerase (RdRp) of the virus is essential for its genome replication and constitutes an attractive target for the identification of antivirals. With the aim of obtaining selective BVDV inhibitors, the crystal structure of BVDV RdRp was used to perform a virtual screening. Approximately 15,000 small molecules from commercial and in-house databases were evaluated and several structurally different compounds were tested in vitro for antiviral activity. Interestingly, of twelve evaluated compounds, five were active and displayed EC50 values in the sub and low-micromolar range. Time of drug addition experiment and measured intracellular BVDV RNA showed that compound 7 act during RNA synthesis. Molecular Dynamics and MM/PBSA calculation were done to characterize the interaction of the most active compounds with RdRp, which will allow future ligand optimization. These studies highlight the use of in silico screening to identify a new class of BVDV inhibitors.


Asunto(s)
Antivirales/farmacología , Virus de la Diarrea Viral Bovina/efectos de los fármacos , Animales , Antivirales/síntesis química , Antivirales/química , Bovinos , Relación Dosis-Respuesta a Droga , Evaluación Preclínica de Medicamentos , Pruebas de Sensibilidad Microbiana , Simulación de Dinámica Molecular , Estructura Molecular , Relación Estructura-Actividad
4.
Bioorg Med Chem ; 25(15): 4055-4063, 2017 08 01.
Artículo en Inglés | MEDLINE | ID: mdl-28600079

RESUMEN

A series of N4-arylsubstituted thiosemicarbazones derived from 1-indanones and a set of compounds lacking such substitution in the N4 position of the thiosemicarbazone moiety were synthesized and evaluated for their anti-bovine viral diarrhea virus (BVDV) activity. Among these, derivatives 2 and 15 displayed high activity (EC50=2.7±0.4 and 0.7±0.1µM, respectively) as inhibitors of BVDV replication. Novel key structural features related to the anti-BVDV activity were identified by structure-activity relationship (SAR) analysis. In a previous study, the thiosemicarbazone of 5,6-dimethoxy-1-indanone (5,6-TSC) was characterized as a non-nucleoside inhibitor (NNI) of the BVDV RNA-dependent RNA polymerase. In the present work, cross-resistance assays were performed with the most active compounds. Such studies were carried out on 5,6-TSC resistant BVDV (BVDV-TSCr T1) carrying mutations in the viral polymerase. This BVDV mutant was also resistant to compound 15. Molecular docking studies and MM/PBSA calculations were performed to assess the most active derivatives at the 5,6-TSC viral polymerase binding site. The differences in the interaction pattern and the binding affinity of derivative 15 either to the wild type or BVDV-TSCr T1 polymerase were key factors to define the mode of action of this compound.


Asunto(s)
Antivirales/síntesis química , Antivirales/farmacología , Virus de la Diarrea Viral Bovina/efectos de los fármacos , Indanos/química , Tiosemicarbazonas/síntesis química , Tiosemicarbazonas/farmacología , Animales , Antivirales/química , Bovinos , Línea Celular , Virus de la Diarrea Viral Bovina/fisiología , Simulación del Acoplamiento Molecular , Análisis Espectral/métodos , Relación Estructura-Actividad , Tiosemicarbazonas/química , Ensayo de Placa Viral , Replicación Viral/efectos de los fármacos
5.
J Nanosci Nanotechnol ; 15(6): 4224-8, 2015 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-26369033

RESUMEN

The current standard of care of the infection by hepatitis C virus (HCV) is effective in a limited number of patients and the high cost hinders therapy affordability and compliance. In this context, the research of new direct-acting antiviral agents (DAAs) for a more effective and long-lasting therapy is an urgent need and an area of active investigation. In an effort to develop novel DAAs, a series of 1-indanone thiosemicarbazones (TSCs) was synthesized and fully characterized. However, the high self-aggregation tendency and extremely poor aqueous solubility of these antiviral candidates often preclude their reliable biological evaluation in vitro. To maintain constant TSC concentrations over the biological assays, different TSC/cyclodextrin complexes were produced. In the present work, we report for the first time the cytotoxicity and antiviral activity of 5,6-dimethoxy TSC inclusion complexes with hydroxypropyl-ß-cyclodextrin on bovine viral diarrhea virus (BVDV) as HCV surrogate model. Results showed a potent suppression of the virus replication, with greater activity for the inclusion complexes than the free compound.


Asunto(s)
Virus de la Diarrea Viral Bovina/efectos de los fármacos , Indanos/química , Modelos Biológicos , Tiosemicarbazonas/química , beta-Ciclodextrinas/química , 2-Hidroxipropil-beta-Ciclodextrina , Animales , Antivirales/química , Antivirales/farmacología , Antivirales/toxicidad , Bovinos , Línea Celular , Supervivencia Celular/efectos de los fármacos , Hepacivirus , Humanos , Indanos/farmacología , Indanos/toxicidad , Tiosemicarbazonas/farmacología , Tiosemicarbazonas/toxicidad , beta-Ciclodextrinas/farmacología , beta-Ciclodextrinas/toxicidad
6.
Ecohealth ; 2024 Jun 06.
Artículo en Inglés | MEDLINE | ID: mdl-38844740

RESUMEN

The current pandemic produced by SARS-CoV-2 and its variants represent an example of the one health concept in which humans and animals are components of the same epidemiologic chain. Animal reservoirs of these viruses are thus the focus of surveillance programs, to monitor their circulation and evolution in potentially new hosts and reservoirs. In this work, we report the detection of the SARS-CoV-2 Gamma variant infection in four specimens of Chaetophractus villosus (big hairy armadillo/armadillo peludo) in Argentina. In addition to the finding of a new wildlife species susceptible to SARS-CoV-2 infection, the identification of the Gamma variant three months after its last detection in humans in Argentina is a noteworthy result, which can be due to alternative non-exclusive scenarios, such as unidentified viral reservoirs, unrecognized circulation in humans or species-specific variation in incubation periods.

7.
Nat Commun ; 15(1): 997, 2024 Feb 02.
Artículo en Inglés | MEDLINE | ID: mdl-38307851

RESUMEN

In the context of continuous emergence of SARS-CoV-2 variants of concern (VOCs), one strategy to prevent the severe outcomes of COVID-19 is developing safe and effective broad-spectrum vaccines. Here, we present preclinical studies of a RBD vaccine derived from the Gamma SARS-CoV-2 variant adjuvanted with Alum. The Gamma-adapted RBD vaccine is more immunogenic than the Ancestral RBD vaccine in terms of inducing broader neutralizing antibodies. The Gamma RBD presents more immunogenic B-cell restricted epitopes and induces a higher proportion of specific-B cells and plasmablasts than the Ancestral RBD version. The Gamma-adapted vaccine induces antigen specific T cell immune responses and confers protection against Ancestral and Omicron BA.5 SARS-CoV-2 challenge in mice. Moreover, the Gamma RBD vaccine induces higher and broader neutralizing antibody activity than homologous booster vaccination in mice previously primed with different SARS-CoV-2 vaccine platforms. Our study indicates that the adjuvanted Gamma RBD vaccine is highly immunogenic and a broad-spectrum vaccine candidate.


Asunto(s)
COVID-19 , SARS-CoV-2 , Animales , Ratones , Humanos , Anticuerpos ampliamente neutralizantes , Vacunas contra la COVID-19 , COVID-19/prevención & control , Vacunas de Subunidad , Adyuvantes Inmunológicos , Epítopos de Linfocito B , Anticuerpos Antivirales , Anticuerpos Neutralizantes , Glicoproteína de la Espiga del Coronavirus/genética
8.
mSphere ; 8(3): e0066222, 2023 Jun 22.
Artículo en Inglés | MEDLINE | ID: mdl-37070983

RESUMEN

SARS-CoV-2 vaccine protection has encountered waning of immune response and breakthrough infections. The hybrid immune response generated by the combination of vaccination and infection was shown to offer higher and broader protection. Here, we present a seroprevalence study of anti-SARS-CoV-2 spike/RBD IgG in 1,121 health care workers immunized with Sputnik V and a follow-up of humoral response at 2 and 24 weeks postvaccination (wpv), including neutralizing antibody response (NAT) against ancestral, Gamma, and Delta variants. The first seroprevalence study showed that among 122 individuals with one dose, 90.2% were seropositive versus 99.7% seropositivity among volunteers with the complete two-dose regimen. At 24 wpv, 98.7% of the volunteers remained seropositive, although antibody levels decreased. IgG levels and NAT were higher in individuals that had acquired COVID-19 previous to vaccination than in naive individuals at 2 and 24 wpv. Antibody levels dropped over time in both groups. In contrast, IgG levels and NAT increased after vaccine breakthrough infection. At 2 wpv, 35/40 naive individuals had detectable NAT against SARS-CoV-2 Gamma and 6/40 against Delta. In turn, 8/9 previously infected individuals developed a neutralizing response against SARS-CoV-2 Gamma and 4/9 against Delta variants. NAT against variants followed a trajectory similar to NAT against ancestral SARS-CoV-2, and breakthrough infection led to an increase in NAT and complete seroconversion against variants. In conclusion, Sputnik V-induced humoral response persisted at 6 months postvaccination, and hybrid immunity induced higher levels of anti-S/RBD antibodies and NAT in previously exposed individuals, boosted the response after vaccination, and conferred wider breadth of protection. IMPORTANCE Since December 2020, Argentina has begun a mass vaccination program. The first vaccine available in our country was Sputnik V, which has been approved for use in 71 countries with a total population of 4 billion people. Despite all the available information, there are fewer published studies on the response induced by Sputnik V vaccination compared to that of other vaccines. Although the global political context has paralyzed the verification by the WHO of the efficacy of this vaccine, our work aims to add new clear and necessary evidence to Sputnik V performance. Our results contribute to general knowledge of the humoral immune response developed by vaccines based on viral vector technology, highlighting the higher immune protection conferred by hybrid immunity and reinforcing the importance of completing vaccination schedules and booster doses to maintain adequate antibody levels.


Asunto(s)
COVID-19 , SARS-CoV-2 , Humanos , Argentina/epidemiología , Vacunas contra la COVID-19 , Estudios de Seguimiento , Estudios Seroepidemiológicos , COVID-19/prevención & control , Vacunación , Anticuerpos Neutralizantes , Anticuerpos Antivirales , Infección Irruptiva , Personal de Salud
9.
Artículo en Inglés | MEDLINE | ID: mdl-37682578

RESUMEN

Introduction: Cannabidiol (CBD), the main non-psychoactive cannabinoid of the Cannabis sativa plant, is a powerful antioxidant compound that in recent years has increased interest due to causes effects in a wide range of biological functions. Zika virus (ZIKV) is a virus transmitted mainly by the Aedes aegypti mosquitoes, which causes neurological diseases, such as microcephaly and Guillain-Barre syndrome. Although the frequency of viral outbreaks has increased recently, no vaccinations or particular chemotherapeutic treatments are available for ZIKV infection. Objectives: The major aim of this study was to explore the in vitro antiviral activity of CBD against ZIKV, expanding also to other dissimilar viruses. Materials and Methods: Cell cultures were infected with enveloped and nonenveloped viruses and treated with non-cytotoxic concentrations of CBD and then, viral titers were determined. Additionally, the mechanism of action of the compound during ZIKV in vitro infections was studied. To study the possible immunomodulatory role of CBD, infected and uninfected Huh-7 cells were exposed to 10 µM CBD during 48 h and levels of interleukins 6 and 8 and interferon-beta (IFN-ß) expression levels were measured. On the other hand, the effect of CBD on cellular membranes was studied. For this, an immunofluorescence assay was performed, in which cell membranes were labeled with wheat germ agglutinin. Finally, intracellular cholesterol levels were measured. Results: CBD exhibited a potent antiviral activity against all the tested viruses in different cell lines with half maximal effective concentration values (CE50) ranging from 0.87 to 8.55 µM. Regarding the immunomodulatory effect of CBD during ZIKV in vitro infections, CBD-treated cells exhibited significantly IFN-ß increased levels, meanwhile, interleukins 6 and 8 were not induced. Furthermore, it was determined that CBD affects cellular membranes due to the higher fluorescence intensity that was observed in CBD-treated cells and lowers intracellular cholesterol levels, thus affecting the multiplication of ZIKV and other viruses. Conclusions: It was demonstrated that CBD inhibits structurally dissimilar viruses, suggesting that this phytochemical has broad-spectrum antiviral effect, representing a valuable alternative in emergency situations during viral outbreaks, like the one caused by severe acute respiratory syndrome coronavirus 2 in 2020.

10.
J Virol ; 85(11): 5436-45, 2011 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-21430053

RESUMEN

In the present work, we described the activity of the thiosemicarbazone derived from 5,6-dimethoxy-1-indanone (TSC), which we previously characterized as a new compound that inhibits bovine viral diarrhea virus (BVDV) infection. We showed that TSC acts at a point of time that coincides with the onset of viral RNA synthesis and that it inhibits the activity of BVDV replication complexes (RCs). Moreover, we have selected five BVDV mutants that turned out to be highly resistant to TSC but still susceptible to ribavirin (RBV). Four of these resistant mutants carried an N264D mutation in the viral RNA-dependent RNA polymerase (RdRp). The remaining mutant showed an A392E mutation within the same protein. Some of these mutants replicated slower than the wild-type (wt) virus in the absence of TSC, whereas others showed a partial reversion to the wt phenotype over several passages in the absence of the compound. The docking of TSC in the crystal structure of the BVDV RdRp revealed a close contact between the indane ring of the compound and several residues within the fingers domain of the enzyme, some hydrophobic contacts, and hydrogen bonds with the thiosemicarbazone group. Finally, in the mutated RdRp from resistant BVDV, these interactions with TSC could not be achieved. Interestingly, TSC inhibited BVDV replication in cell culture synergistically with RBV. In conclusion, TSC emerges as a new nonnucleoside inhibitor of BVDV RdRp that is synergistic with RBV, a feature that turns it into a potential compound to be evaluated against hepatitis C virus (HCV).


Asunto(s)
Antivirales/farmacología , Virus de la Diarrea Viral Bovina/efectos de los fármacos , Indanos/farmacología , ARN Viral/biosíntesis , Tiosemicarbazonas/farmacología , Replicación Viral/efectos de los fármacos , Sustitución de Aminoácidos , Animales , Antivirales/química , Línea Celular , Virus de la Diarrea Viral Bovina/fisiología , Farmacorresistencia Viral , Humanos , Indanos/química , Modelos Moleculares , Mutación Missense , Estructura Terciaria de Proteína , ARN Polimerasa Dependiente del ARN/genética , ARN Polimerasa Dependiente del ARN/metabolismo , Ribavirina/farmacología , Tiosemicarbazonas/química , Proteínas Virales/genética , Proteínas Virales/metabolismo
11.
Vet Immunol Immunopathol ; 254: 110519, 2022 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-36434944

RESUMEN

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the etiological agent of coronavirus disease 2019 (COVID-19), has rapidly spread worldwide. The monitoring of animals has shown that certain species may be susceptible to be infected with the virus. The present study aimed to evaluate the presence of SARS-CoV-2 antibodies by ELISA and virus neutralization (VN) in pets from owners previously confirmed as COVID-19-positive in Argentina. Serum samples of 38 pets (seven cats and 31 dogs) were obtained for SARS-CoV-2 antibody detection. Three out of the seven cats and 14 out of the 31 dogs were positive for SARS-CoV-2 by ELISA, and one cat and six dogs showed the presence of neutralizing antibodies in which the cat and two of the six dogs showed high titers. Another dog from which three serum samples had been obtained within eight months from the diagnosis of its owner showed the presence of antibodies at different times by both ELISA and VN. However, the results showed that the antibodies decreased slightly from the first to the third sample. Our results provide evidence that SARS-CoV-2 infection in pets living with COVID-19-positive humans from Argentina during the outbreak of SARS-CoV-2 can be detected by serology assay.


Asunto(s)
COVID-19 , Enfermedades de los Gatos , Enfermedades de los Perros , Humanos , Perros , Animales , Gatos , COVID-19/epidemiología , COVID-19/veterinaria , SARS-CoV-2 , Brotes de Enfermedades , Anticuerpos Antivirales , Anticuerpos Neutralizantes , Enfermedades de los Gatos/epidemiología , Enfermedades de los Perros/epidemiología
12.
Front Immunol ; 13: 844837, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-35296091

RESUMEN

In this work, we evaluated recombinant receptor binding domain (RBD)-based vaccine formulation prototypes with potential for further clinical development. We assessed different formulations containing RBD plus alum, AddaS03, AddaVax, or the combination of alum and U-Omp19: a novel Brucella spp. protease inhibitor vaccine adjuvant. Results show that the vaccine formulation composed of U-Omp19 and alum as adjuvants has a better performance: it significantly increased mucosal and systemic neutralizing antibodies in comparison to antigen plus alum, AddaVax, or AddaS03. Antibodies induced with the formulation containing U-Omp19 and alum not only increased their neutralization capacity against the ancestral virus but also cross-neutralized alpha, lambda, and gamma variants with similar potency. Furthermore, the addition of U-Omp19 to alum vaccine formulation increased the frequency of RBD-specific geminal center B cells and plasmablasts. Additionally, U-Omp19+alum formulation induced RBD-specific Th1 and CD8+ T-cell responses in spleens and lungs. Finally, this vaccine formulation conferred protection against an intranasal severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) challenge of K18-hACE2 mice.


Asunto(s)
Adyuvantes Inmunológicos/metabolismo , Linfocitos B/inmunología , Proteínas de la Membrana Bacteriana Externa/metabolismo , Brucella/metabolismo , Vacunas contra la COVID-19/inmunología , COVID-19/inmunología , Centro Germinal/inmunología , SARS-CoV-2/fisiología , Compuestos de Alumbre/metabolismo , Animales , Anticuerpos Neutralizantes/sangre , Anticuerpos Antivirales , Formación de Anticuerpos , Proteínas de la Membrana Bacteriana Externa/inmunología , Brucella/inmunología , Resistencia a la Enfermedad , Femenino , Humanos , Ratones , Ratones Endogámicos BALB C , Ratones Endogámicos C57BL , Glicoproteína de la Espiga del Coronavirus/inmunología
13.
Front Chem ; 8: 590235, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-33425849

RESUMEN

Bovine viral diarrhea virus (BVDV) belongs to the Pestivirus genus (Flaviviridae). In spite of the availability of vaccines, the virus is still causing substantial financial losses to the livestock industry. In this context, the use of antiviral agents could be an alternative strategy to control and reduce viral infections. The viral RNA-dependent RNA polymerase (RdRp) is essential for the replication of the viral genome and constitutes an attractive target for the identification of antiviral compounds. In a previous work, we have identified potential molecules that dock into an allosteric binding pocket of BVDV RdRp via a structure-based virtual screening approach. One of them, N-(2-morpholinoethyl)-2-phenylquinazolin-4-amine [1, 50% effective concentration (EC50) = 9.7 ± 0.5 µM], was selected to perform different chemical modifications. Among 24 derivatives synthesized, eight of them showed considerable antiviral activity. Molecular modeling of the most active compounds showed that they bind to a pocket located in the fingers and thumb domains in BVDV RdRp, which is different from that identified for other non-nucleoside inhibitors (NNIs) such as thiosemicarbazone (TSC). We selected compound 2-[4-(2-phenylquinazolin-4-yl)piperazin-1-yl]ethanol (1.9; EC50 = 1.7 ± 0.4 µM) for further analysis. Compound 1.9 was found to inhibit the in vitro replication of TSC-resistant BVDV variants, which carry the N264D mutation in the RdRp. In addition, 1.9 presented adequate solubility in different media and a high-stability profile in murine and bovine plasma.

14.
Eur J Med Chem ; 43(8): 1767-73, 2008 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-18063227

RESUMEN

Identification of new therapeutic agents for the treatment of viral diseases represents an area of active investigation. In an effort to develop new antiviral compounds, a series of 1-indanone thiosemicarbazone derivatives were synthesized. These derivatives were structurally characterized using several spectroscopic techniques and evaluated against bovine viral diarrhoea virus as a surrogate model for hepatitis C virus. Thiosemicarbazone 2m showed potent anti-bovine viral diarrhoea virus activity with a higher selectivity index (SI=80.29) than that of ribavirin (SI=11.64). This result determines the potentiality of these thiosemicarbazones as antiviral agents for the treatment of infections caused by other highly related members of Flaviviridae family, as hepatitis C virus.


Asunto(s)
Antivirales/síntesis química , Antivirales/farmacología , Virus de la Diarrea Viral Bovina/efectos de los fármacos , Indanos/química , Tiosemicarbazonas/síntesis química , Tiosemicarbazonas/farmacología , Animales , Antivirales/química , Bovinos , Línea Celular , Indanos/síntesis química , Indanos/farmacología , Estructura Molecular , Relación Estructura-Actividad , Tiosemicarbazonas/química
15.
PLoS One ; 9(6): e100528, 2014.
Artículo en Inglés | MEDLINE | ID: mdl-24950191

RESUMEN

Bovine viral diarrhea virus (BVDV) is the prototype Pestivirus. BVDV infection is distributed worldwide and causes serious problems for the livestock industry. The thiosemicarbazone of 5,6-dimethoxy-1-indanone (TSC) is a non-nucleoside polymerase inhibitor (NNI) of BVDV. All TSC-resistant BVDV variants (BVDV-TSCr T1-5) present an N264D mutation in the NS5B gene (RdRp) whereas the variant BVDV-TSCr T1 also presents an NS5B A392E mutation. In the present study, we carried out twenty passages of BVDV-TSCr T1-5 in MDBK cells in the absence of TSC to evaluate the stability of the resistance. The viral populations obtained (BVDV R1-5) remained resistant to the antiviral compound and conserved the mutations in NS5B associated with this phenotype. Along the passages, BVDV R2, R3 and R5 presented a delay in the production of cytopathic effect that correlated with a decrease in cell apoptosis and intracellular accumulation of viral RNA. The complete genome sequences that encode for NS2 to NS5B, Npro and Erns were analyzed. Additional mutations were detected in the NS5B of BVDV R1, R3 and R4. In both BVDV R2 and R3, most of the mutations found were localized in NS5A, whereas in BVDV R5, the only mutation fixed was NS5A V177A. These results suggest that mutations in NS5A could alter BVDV cytopathogenicity. In conclusion, the stability of the resistance to TSC may be due to the fixation of different compensatory mutations in each BVDV-TSCr. During their replication in a TSC-free medium, some virus populations presented a kind of interaction with the host cell that resembled a persistent infection: decreased cytopathogenicity and viral genome synthesis. This is the first report on the stability of antiviral resistance and on the evolution of NNI-resistant BVDV variants. The results obtained for BVDV-TSCr could also be applied for other NNIs.


Asunto(s)
ARN Polimerasas Dirigidas por ADN/antagonistas & inhibidores , Virus de la Diarrea Viral Bovina/efectos de los fármacos , Virus de la Diarrea Viral Bovina/enzimología , Farmacorresistencia Viral/efectos de los fármacos , Indanos/química , Tiosemicarbazonas/química , Tiosemicarbazonas/farmacología , Secuencia de Aminoácidos , Animales , Apoptosis/efectos de los fármacos , Secuencia de Bases , Bovinos , Línea Celular , Secuencia Conservada , Efecto Citopatogénico Viral/efectos de los fármacos , Virus de la Diarrea Viral Bovina/genética , Virus de la Diarrea Viral Bovina/fisiología , Farmacorresistencia Viral/genética , Inhibidores Enzimáticos/química , Inhibidores Enzimáticos/farmacología , Datos de Secuencia Molecular , Mutación , ARN Viral/metabolismo , Proteínas no Estructurales Virales/química , Proteínas no Estructurales Virales/genética , Replicación Viral/efectos de los fármacos
16.
Int J Antimicrob Agents ; 36(6): 566-9, 2010 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-20947311

RESUMEN

The antiviral activities of lamivudine (3TC; 2',3'-dideoxy-3'-thiacytidine) and six 5'-O-carbonates of 3TC were determined by inhibition of hepatitis B virus (HBV) replication in HepG2 2.2.15 cells. HBV DNA in cell supernatants was quantified by real-time polymerase chain reaction (PCR). The results showed that 3TC-Etha was six times more active than 3TC and that 3TC-Buta, 3TC-Hexa and 3TC-Octa were approximately three times more active than 3TC. In contrast, 3TC-Penta and 3TC-Metha showed anti-HBV activity similar to that of the parent compound 3TC. In conclusion, 5'-O-carbonates of 3TC appear to be promising candidates as anti-HBV compounds. This modification could optimise the use of 3TC, a well-tolerated, effective and inexpensive drug, in monotherapy or combined therapy for chronic HBV infections as well as human immunodeficiency virus (HIV)/HBV co-infections.


Asunto(s)
Antivirales/farmacología , Desoxicitidina/análogos & derivados , Virus de la Hepatitis B/efectos de los fármacos , Profármacos/farmacología , Línea Celular , Medios de Cultivo/química , ADN Viral/análisis , ADN Viral/genética , Desoxicitidina/farmacología , Hepatocitos/virología , Humanos , Lamivudine/farmacología , Replicación Viral/efectos de los fármacos
17.
Rev. Fac. Nac. Salud Pública ; 29(4): 504-512, dic. 2011.
Artículo en Español | LILACS | ID: lil-651168

RESUMEN

Gestionar la salud y la seguridad en el trabajo implica considerarprocesos internos de las organizaciones, como son lagestión del conocimiento y del talento humano, procesos afectadospor fenómenos globalizadores que impactan en diferentesdimensiones (económica, ambiental, laboral), con especialacento en países como Colombia. Objetivo: presentar una alternativapedagógica que aporte a la gestión del conocimientoen pymes para mejorar condiciones laborales y apoyar procesosde innovación en ellas. Metodología: estudio exploratorioy descriptivo. Se parte de analizar conceptos relacionados conel mejoramiento de condiciones de trabajo, así como de experienciasobtenidas en proyectos desarrollados, que incluyeronla relación universidad-empresa, con una visión sistémica propiade la ergonomía y de la interdisciplinariedad característicadel ejercicio del diseño industrial. Resultado: la propuesta,avalada por instituciones regionales para adelantar una pruebapiloto, se enmarca en los principios que establece la promociónde la salud en los lugares de trabajo y vincula una metodologíaque impacta en el núcleo tecnológico de las empresasy contribuye con el empoderamiento del personal involucrado.Conclusión: resulta indispensable el apoyo y compromiso dela organización a través de una política que facilite la participaciónactiva de los trabajadores en estos procesos.


Managing health and safety at work involves considering twointernal processes common to all organizations: knowledge andhuman talent management. These two processes are affectedby globalizing phenomena that have an effect at the economic,environmental, and occupational levels. This is especially true forcountries like Colombia. Objective: to provide an educationalalternative that contributes to knowledge management in SME’sin order to improve the working conditions and to supporttheir innovation processes. Methodology: an exploratory anddescriptive study. We start by analyzing the concepts related tothe improvement of working conditions and experiences fromprevious projects involving the university-industry relationship.This is done from the systemic viewpoint that characterizesthe ergonomics and interdisciplinary perspectives of theprofessional practice of industrial design. Result: the proposalwas approved by regional institutions wishing to conducta pilot study, and is based on principles establishing healthpromotion at the workplace. It also includes a methodology foraffecting the technological core of companies and contributesto the empowerment of the personnel involved. Conclusion:it is mandatory that organizations express their supportand commitment through a policy that facilitates the activeparticipation of employees in these processes.


Asunto(s)
Promoción de la Salud , Ergonomía , Gestión del Conocimiento , Innovación Organizacional , Condiciones de Trabajo
18.
Rev. Fac. Nac. Salud Pública ; 29(4): 484-493, dic. 2011.
Artículo en Español | LILACS | ID: lil-651166

RESUMEN

Objetivo: exponer aspectos relevantes para implementar lapromoción de la salud en los lugares de trabajo (pslt) en procesosde organización del sector salud, asumida como una herramientaestratégica para gestionar la salud y la seguridad enambientes laborales. Metodología: tras una revisión conceptualsobre pslt en el 2009, se realizó un estudio de caso sobreel desarrollo de la estrategia en tres hospitales de tercer nivelde Bogotá. Se trata de un estudio descriptivo-transversal aprobadopor el Comité de Ética de la Facultad de Enfermería de laUniversidad Nacional de Colombia. Resultados: aunque existenprogramas de salud ocupacional que imprimen el espíritude la pslt en su contenido, el nivel de desarrollo no es coherente con ello. Se analizaron los siguientes criterios: estrategia y compromiso, recursos humanos y organización, responsabilidad social, planificación, desarrollo y resultados, que no fueron bien valorados por trabajadores. Discusión: el enfoque tradicional sobre salud ocupacional y la precaria incorporación de los principios de la pslt en procesos organizacionales se refleja en las acciones desarrolladas y en las expectativas frente al tema; por tanto, es necesario desarrollar acciones desde la política pública y fortalecer la capacidad institucional para garantizar la viabilidad de la pslt en el sector salud.


Objective: to discuss issues that are relevant to theimplementation of workplace health promotion (whp) inorganization processes of the health sector as a strategic toolto manage health and safety at the workplace. Methods: aftera conceptual review of whp in 2009, a qualitative case studyon the development of this strategy in third level hospitals ofBogotá was carried out. This descriptive and cross-sectionalstudy was approved by the Ethics Committee of the Faculty ofNursing at the National University of Colombia. Results:although there are occupational health programs that conveythe spirit of whp in their content, its level of developmentis not consistently linked to it. The following criteria were analyzed: strategy and commitment, human resources and organization, social responsibility, planning, and development and results, all of which were not well valued by workers. Final considerations: the traditional approach to occupational health and the poor integration of the WHP principles into organizational processes are reflected in the actions taken and the expectations regarding the subject. Therefore, actions should be taken in terms of public policies to strengthen the institutional capacity to ensure the feasibility of whp in the health sector.


Asunto(s)
Promoción de la Salud , Hospitales , Salud Laboral , Administración de Personal en Hospitales
19.
Arq. neuropsiquiatr ; 45(1): 72-80, mar. 1987. tab, ilus
Artículo en Portugués | LILACS | ID: lil-39863

RESUMEN

A síndrome de Russel é caracterizada por emaciaçäo e hiperatividade da criança e é decorrente de processo expansivo hipotalâmico. O caso relatado apresenta os sinais típicos da síndrome associados a distúrbios na secreçäo do hormônio do crescimento e quadro de puberdade precoce desenvolvimento aos 4 anos de idade. A patogênese das alteraçöes é discutida e relacionada com a disfunçäo do eixo hipotálamo-hipofisário, produzida pela evoluçäo do crescimento tumoral


Asunto(s)
Lactante , Humanos , Femenino , Astrocitoma/complicaciones , Neoplasias Encefálicas/complicaciones , Diencéfalo , Emaciación/etiología , Pubertad Precoz/etiología , Síndrome
20.
Rev. méd. Minas Gerais ; 18(4,supl.1): S98-S106, nov. 2008.
Artículo en Portugués | LILACS | ID: lil-557667

RESUMEN

Os pacientes portadores de epilepsia têm, potencialmente, condições de desenvolver alterações de ordem cognitiva e/ou psíquicas, seja pela multiplicidade de possibilidades de desenvolvimento do foco irritativo cerebral ou proporcional à diversificação e funcionalidade dos grupamentos neuronais. O propósito do presente estudo é mostrar a importância da abordagem desses pacientes e seus transtornos fora do ictus epiléptico. Sabe-se que os transtornos mentais são mais comuns em epilépticos do que na população em geral, entretanto, esta correlação ainda é motivo de controvérsias. A diversidade de linhas de pesquisas tenta desvendar esta instigante relação de causa-efeito. Estudos revelam que essa vinculação se deve à inadequada avaliação de grupos-controle, isto é, falhas metodológicas ou, ainda, conseqüência dos mecanismos envolvidos com a própria doença: neuropatologia comum, predisposição genética, transtornos de desenvolvimento, efeitos epilépticos ictal e subictal, hipometabolismo, alterações de receptores sensitivos, alterações secundárias endocrinológicas, doenças psiquiátricas primárias, efeitos colaterais de drogas antiepilépticas e transtornos psicossociais. Outras linhas de pesquisas, contudo, ressaltam a importância de se focalizarem esses transtornos como depressão, ansiedade e psicoses e sua relação com a epilepsia nas fases pré-ictal, interictal e pós-ictal. Destacam também que a maior incidência desses transtornos ocorre em pacientes que têm focos de suas crises no lobo frontal, lobo temporal – sistema límbico. Estima-se que 30% a 70% dos pacientes epilépticos tenham algum déficit cognitivo ou alterações de humor e, em menor incidência, psicoses.


Patients suffering from epilepsy are prone to cognitive and/or psychical alterations, whether for their multiplicity opportunities for the development of irritative focus or it is proportional to the diverse functions neuronal groupings. The aim of the present study is to demonstrate the importance of assisting these patients and taking care of their disorders out of an epileptic ictus. It is known that mental disorders are more frequent in epileptic patients than in the general population, but there are still some voices of dissent about this correlation. Several different lines of research are striving to understand this instigating cause and effect relationship. Studies have revealed that this correlation results from an inadequate evaluation of control groups; that is, methodological shortcomings or, still, the consequence of some mechanisms inherent to the disease itself: common neuropathology, genetic predisposition, development disorders, subictal and ictal epilepti effects, hypometabolism, sensitive receptor alterations, secondary endocrinologic alterations, primary psychiatric diseases, side effects of antiepileptic drugs and psychosocial disorders. Other lines of research, however, highlight the importance of regard these disorders as depression, anxiety and psychoses and their relationship with the pre-ictal, interictal and post-ictal stages of epilepsy. They also point out that these disorders are more frequent in patients whose crises’ focal points are the frontal lobe, temporal lobe – limbic system. It is estimated that 30 to 70% of the epileptic patients have a cognitive deficit or humor alterations, and less frequently, psychoses.


Asunto(s)
Humanos , Epilepsia/complicaciones , Trastornos Mentales/etiología , Epilepsia/etiología , Trastornos Psicóticos/fisiopatología
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