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1.
Arch. argent. pediatr ; 122(1): e202302992, feb. 2024. tab
Artigo em Inglês, Espanhol | LILACS, BINACIS | ID: biblio-1525290

RESUMO

La resistencia a los antirretrovirales (ARV) es un problema de salud pública. Con el uso de inhibidores de la integrasa (INSTI) en pediatría, también comienzan a aparecer resistencias. El objetivo de esta comunicación es describir 3 casos con resistencia a los INSTI. Se describen 3 pacientes pediátricos con transmisión vertical del virus de la inmunodeficiencia humana (VIH). Iniciaron ARV de lactantes y preescolares, con mala adherencia al tratamiento, cursaron con diferentes planes secundarios a comorbilidades asociadas y fallas virológicas por resistencia. Los 3 casos clínicos describen la rápida aparición de resistencia frente a la falla virológica y el compromiso de los INSTI. La adherencia debe ser supervisada para detectar precozmente el aumento de la viremia. La falla virológica en un paciente tratado con raltegravir obliga a un rápido cambio de esquema ARV, ya que continuar utilizándolo podría favorecer nuevas mutaciones y resistencia a los INSTI de segunda generación.


Antiretroviral (ARV) drug resistance is a public health issue. Resistance has also been observed in the case of integrase strand transfer inhibitors (INSTIs) used in pediatrics. The objective of this article is to describe 3 cases of INSTI resistance. These are the cases of 3 children with vertically-transmitted human immunodeficiency virus (HIV). They were started on ARVs as infants and preschoolers, with poor treatment adherence, and had different management plans due to associated comorbidities and virological failure due to resistance. In the 3 cases, resistance developed rapidly as a result of virological failure and INSTI involvement. Treatment adherence should be monitored so that any increase in viremia can be detected early. Virological failure in a patient treated with raltegravir forces to a rapid change in ARV therapy because its continued use may favor new mutations and resistance to second-generation INSTIs.


Assuntos
Humanos , Masculino , Feminino , Pré-Escolar , Criança , Adolescente , Infecções por HIV/tratamento farmacológico , HIV-1/genética , Inibidores de Integrase de HIV/uso terapêutico , Inibidores de Integrase de HIV/farmacologia , Fármacos Anti-HIV/uso terapêutico , Uruguai , Raltegravir Potássico/uso terapêutico , Raltegravir Potássico/farmacologia , Mutação
2.
Arch Argent Pediatr ; 122(1): e202302992, 2024 02 01.
Artigo em Inglês, Espanhol | MEDLINE | ID: mdl-37216306

RESUMO

Antiretroviral (ARV) drug resistance is a public health issue. Resistance has also been observed in the case of integrase strand transfer inhibitors (INSTIs) used in pediatrics. The objective of this article is to describe 3 cases of INSTI resistance. These are the cases of 3 children with vertically-transmitted human immunodeficiency virus (HIV). They were started on ARVs as infants and preschoolers, with poor treatment adherence, and had different management plans due to associated comorbidities and virological failure due to resistance. In the 3 cases, resistance developed rapidly as a result of virological failure and INSTI involvement. Treatment adherence should be monitored so that any increase in viremia can be detected early. Virological failure in a patient treated with raltegravir forces to a rapid change in ARV therapy because its continued use may favor new mutations and resistance to second-generation INSTIs.


La resistencia a los antirretrovirales (ARV) es un problema de salud pública. Con el uso de inhibidores de la integrasa (INSTI) en pediatría, también comienzan a aparecer resistencias. El objetivo de esta comunicación es describir 3 casos con resistencia a los INSTI. Se describen 3 pacientes pediátricos con transmisión vertical del virus de la inmunodeficiencia humana (VIH). Iniciaron ARV de lactantes y preescolares, con mala adherencia al tratamiento, cursaron con diferentes planes secundarios a comorbilidades asociadas y fallas virológicas por resistencia. Los 3 casos clínicos describen la rápida aparición de resistencia frente a la falla virológica y el compromiso de los INSTI. La adherencia debe ser supervisada para detectar precozmente el aumento de la viremia. La falla virológica en un paciente tratado con raltegravir obliga a un rápido cambio de esquema ARV, ya que continuar utilizándolo podría favorecer nuevas mutaciones y resistencia a los INSTI de segunda generación.


Assuntos
Fármacos Anti-HIV , Infecções por HIV , Inibidores de Integrase de HIV , HIV-1 , Humanos , Criança , Inibidores de Integrase de HIV/uso terapêutico , Inibidores de Integrase de HIV/farmacologia , Uruguai , HIV-1/genética , Raltegravir Potássico/farmacologia , Raltegravir Potássico/uso terapêutico , Infecções por HIV/tratamento farmacológico , Fármacos Anti-HIV/uso terapêutico , Mutação
3.
Viruses ; 15(7)2023 07 04.
Artigo em Inglês | MEDLINE | ID: mdl-37515189

RESUMO

The Venezuelan equine encephalitis virus (VEEV) nonstructural protein 2 (nsP2) cysteine protease (EC 3.4.22.B79) is essential for viral replication. High throughput in silico/in vitro screening using a focused set of known cysteine protease inhibitors identified two epoxysuccinyl prodrugs, E64d and CA074 methyl ester (CA074me) and a reversible oxindole inhibitor. Here, we determined the X-ray crystal structure of the CA074-inhibited nsP2 protease and compared it with our E64d-inhibited structure. We found that the two inhibitors occupy different locations in the protease. We designed hybrid inhibitors with improved potency. Virus yield reduction assays confirmed that the viral titer was reduced by >5 logs with CA074me. Cell-based assays showed reductions in viral replication for CHIKV, VEEV, and WEEV, and weaker inhibition of EEEV by the hybrid inhibitors. The most potent was NCGC00488909-01 which had an EC50 of 1.76 µM in VEEV-Trd-infected cells; the second most potent was NCGC00484087 with an EC50 = 7.90 µM. Other compounds from the NCATS libraries such as the H1 antihistamine oxatomide (>5-log reduction), emetine, amsacrine an intercalator (NCGC0015113), MLS003116111-01, NCGC00247785-13, and MLS00699295-01 were found to effectively reduce VEEV viral replication in plaque assays. Kinetic methods demonstrated time-dependent inhibition by the hybrid inhibitors of the protease with NCGC00488909-01 (Ki = 3 µM) and NCGC00484087 (Ki = 5 µM). Rates of inactivation by CA074 in the presence of 6 mM CaCl2, MnCl2, or MgCl2 were measured with varying concentrations of inhibitor, Mg2+ and Mn2+ slightly enhanced inhibitor binding (3 to 6-fold). CA074 inhibited not only the VEEV nsP2 protease but also that of CHIKV and WEEV.


Assuntos
Cisteína Proteases , Vírus da Encefalite Equina Venezuelana , Animais , Cavalos , Replicação Viral , Inibidores de Cisteína Proteinase/farmacologia
4.
Antioxidants (Basel) ; 12(6)2023 May 29.
Artigo em Inglês | MEDLINE | ID: mdl-37371900

RESUMO

Herpes simplex virus type 1 (HSV-1) and type 2 (HSV-2) infections are highly prevalent in the human population and produce mild to life-threatening diseases. These viruses interfere with the function and viability of dendritic cells (DCs), which are professional antigen-presenting cells that initiate and regulate the host's antiviral immune responses. Heme oxygenase-1 (HO-1) is an inducible host enzyme with reported antiviral activity against HSVs in epithelial cells and neurons. Here, we sought to assess whether HO-1 modulates the function and viability of DCs upon infection with HSV-1 or HSV-2. We found that the stimulation of HO-1 expression in HSV-inoculated DCs significantly recovered the viability of these cells and hampered viral egress. Furthermore, HSV-infected DCs stimulated to express HO-1 promoted the expression of anti-inflammatory molecules, such as PDL-1 and IL-10, and the activation of virus-specific CD4+ T cells with regulatory (Treg), Th17 and Treg/Th17 phenotypes. Moreover, HSV-infected DCs stimulated to express HO-1 and then transferred into mice, promoted the activation of virus-specific T cells and improved the outcome of HSV-1 skin infection. These findings suggest that stimulation of HO-1 expression in DCs limits the deleterious effects of HSVs over these cells and induces a favorable virus-specific immune response in the skin against HSV-1.

5.
Rev Bras Farmacogn ; 33(3): 543-550, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37151219

RESUMO

Since ancient times, viruses such as dengue, herpes, Ebola, AIDS, influenza, chicken meat, and SARS have been roaming around causing great health burdens. Currently, the prescribed antiviral drugs have not cured the complications caused by viruses, whereas viral replication was not controlled by them. The treatments suggested are not only ineffectual, but also sometimes inefficient against viruses at all stages of the viral cycle as well. To fight against these contagious viruses, people rely heavily on medicinal plants to enhance their innate and adaptive immune systems. In this research, the preparation of ligands and proteins was performed using the Maestro V.13.2 module tool. This software, consisting of LigPrep, Grid Generation, SiteMap, and Glide XP, has each contributed significantly to the preparation of ligands and proteins. Ultimately, the research found that (R)-(+)-rosmarinic acid was found to have significant docking scores of - 10.847 for herpes virus, of - 10.033 for NS5, and - 7.259 for NS1. In addition, the Prediction of Activity Spectra for Substances (PASS) server indicates that rosmarinic acid possesses a diverse spectrum of enzymatic activities, as probability active (Pa) values start at > 0.751, whereas it has fewer adverse effects than the drugs prescribed for viruses. Accordingly, it was found the rate of acute toxicity values of (R)-(+)-rosmarinic acid at doses LD50 log10 (mmol/g) and LD50 (mg/g) in different routes of administration, such as intraperitoneal, intravenous, oral, and subcutaneous. Ultimately, the present study concluded that (R)-(+)-rosmarinic acid would expose significant antiviral effects in in vitro and in vivo experiments, and this research would be a valuable asset for the future, especially for those who wish to discover a drug molecule for a variety of viruses. Supplementary Information: The online version contains supplementary material available at 10.1007/s43450-023-00381-y.

6.
Curr Top Med Chem ; 21(23): 2134-2154, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34348625

RESUMO

BACKGROUND: Dihydroorotate dehydrogenase (DHODH) has long been recognized as an important drug target for proliferative and parasitic diseases, including compounds that exhibit trypanocidal action and broad-spectrum antiviral activity. Despite numerous and successful efforts in structural and functional characterization of DHODHs, as well as in the development of inhibitors, DHODH hot spots remain largely unmapped and underexplored. OBJECTIVE: This review describes the tools that are currently available for the identification and characterization of hot spots in protein structures and how freely available webservers can be exploited to predict DHODH hot spots. Moreover, it provides for the first time a review of the antiviral properties of DHODH inhibitors. METHODS: X-ray structures from human (HsDHODH) and Trypanosoma cruzi DHODH (TcDHODH) had their hot spots predicted by both FTMap and Fragment Hotspot Maps web servers. RESULTS: FTMap showed that hot spot occupancy in HsDHODH is correlated with the ligand efficiency (LE) of its known inhibitors, and Fragment Hotspot Maps pointed out the contribution of selected moieties to the overall LE. The conformational flexibility of the active site loop in TcDHODH was found to have a major impact on the druggability of the orotate binding site. In addition, both FTMap and Fragment Hotspot Maps servers predict a novel pocket in TcDHODH dimer interface (S6 site). CONCLUSION: This review reports how hot spots can be exploited during hit-to-lead steps, docking studies or even to improve inhibitor binding profile and by doing so using DHODH as a model, points to new drug development opportunities.


Assuntos
Di-Hidro-Orotato Desidrogenase/antagonistas & inibidores , Di-Hidro-Orotato Desidrogenase/química , Desenvolvimento de Medicamentos/tendências , Antivirais , Di-Hidro-Orotato Desidrogenase/metabolismo , Humanos , Trypanosoma cruzi/enzimologia
7.
Virus Res ; 292: 198251, 2021 01 15.
Artigo em Inglês | MEDLINE | ID: mdl-33259871

RESUMO

The resistance of hepatitis C virus (HCV) to direct-acting antiviral agents, used in chronic hepatitis C treatment, consists of a natural process resulting from resistance-associated substitutions (RASs) at specific amino acid regions. To identify and establish the natural prevalence of RASs in the NS3 gene in patients with chronic hepatitis C in the state of Pará, northern Brazil. Molecular analysis was performed on a total of 35 patients infected with HCV genotype 1, who were treatment-naive to protease inhibitors. HCV RNA was extracted from plasma and the NS3 region was amplified and submitted to DNA sequencing (Sanger). The general natural prevalence of RASs in the NS3 gene was 37.5 % (Y56F and S122T). The substitutions Y56F (34.3 %), S122T (3.1 %), V132I (15.6 %) and V170I (9.3 %) were identified. Y56F and S122T provide resistance to the protease inhibitors grazoprevir and simeprevir, respectively. All amino acid substitutions in the NS3 gene, including RASs, identified in patients from the state of Pará were present in other Brazilian studies. The natural presence of RASs in this study reflects the elevated genetic variability of HCV.


Assuntos
Substituição de Aminoácidos , Hepacivirus/genética , Hepatite C Crônica/virologia , Proteínas não Estruturais Virais/genética , Adulto , Idoso , Antivirais/farmacologia , Brasil , Farmacorresistência Viral , Feminino , Hepacivirus/efeitos dos fármacos , Hepacivirus/metabolismo , Humanos , Masculino , Pessoa de Meia-Idade , Mutação de Sentido Incorreto , Estudos Prospectivos , Inibidores de Proteases/farmacologia , Proteínas não Estruturais Virais/metabolismo
8.
Virology ; 543: 34-42, 2020 04.
Artigo em Inglês | MEDLINE | ID: mdl-32056845

RESUMO

Zika Virus (ZIKV) is a Flavivirus transmitted primarily via the bite of infected Aedes aegypti mosquitoes. Globally, 87 countries and territories have recorded autochthonous mosquito-borne transmission of ZIKV as at July 2019 and distributed across four of the six WHO Regions. Outbreaks of ZIKV infection peaked in 2016 and declined substantially throughout 2017 and 2018 in the Americas region. There is the likely risk for ZIKV to spread to more countries. There is also the potential for the re-emergence of ZIKV in all places with prior reports of the virus transmission. The current status of ZIKV transmission and spread is, however, a global health threat, and from the aforementioned, has the potential to re-emerge as an epidemic. This review summarizes the past and present spread of ZIKV outbreak-2007-2019, the genome, transmission cycle, clinical manifestations, vaccine and antiviral drug advancement.


Assuntos
Antivirais/uso terapêutico , Mosquitos Vetores/virologia , Vacinas Virais , Infecção por Zika virus/epidemiologia , Infecção por Zika virus/transmissão , Zika virus/genética , Brasil/epidemiologia , Cabo Verde/epidemiologia , Surtos de Doenças , Feminino , Genoma Viral , Humanos , Masculino , Ilhas do Pacífico/epidemiologia , Vacinas Virais/imunologia , Zika virus/imunologia , Zika virus/patogenicidade , Infecção por Zika virus/diagnóstico , Infecção por Zika virus/tratamento farmacológico
9.
Antiviral Res ; 164: 106-122, 2019 04.
Artigo em Inglês | MEDLINE | ID: mdl-30742841

RESUMO

The alphaviral nonstructural protein 2 (nsP2) cysteine proteases (EC 3.4.22.-) are essential for the proteolytic processing of the nonstructural (ns) polyprotein and are validated drug targets. A common secondary role of these proteases is to antagonize the effects of interferon (IFN). After delineating the cleavage site motif of the Venezuelan equine encephalitis virus (VEEV) nsP2 cysteine protease, we searched the human genome to identify host protein substrates. Here we identify a new host substrate of the VEEV nsP2 protease, human TRIM14, a component of the mitochondrial antiviral-signaling protein (MAVS) signalosome. Short stretches of homologous host-pathogen protein sequences (SSHHPS) are present in the nonstructural polyprotein and TRIM14. A 25-residue cyan-yellow fluorescent protein TRIM14 substrate was cleaved in vitro by the VEEV nsP2 protease and the cleavage site was confirmed by tandem mass spectrometry. A TRIM14 cleavage product also was found in VEEV-infected cell lysates. At least ten other Group IV (+)ssRNA viral proteases have been shown to cleave host proteins involved in generating the innate immune responses against viruses, suggesting that the integration of these short host protein sequences into the viral protease cleavage sites may represent an embedded mechanism of IFN antagonism. This interference mechanism shows several parallels with those of CRISPR/Cas9 and RNAi/RISC, but with a protease recognizing a protein sequence common to both the host and pathogen. The short host sequences embedded within the viral genome appear to be analogous to the short phage sequences found in a host's CRISPR spacer sequences. To test this algorithm, we applied it to another Group IV virus, Zika virus (ZIKV), and identified cleavage sites within human SFRP1 (secreted frizzled related protein 1), a retinal Gs alpha subunit, NT5M, and Forkhead box protein G1 (FOXG1) in vitro. Proteolytic cleavage of these proteins suggests a possible link between the protease and the virus-induced phenotype of ZIKV. The algorithm may have value for selecting cell lines and animal models that recapitulate virus-induced phenotypes, predicting host-range and susceptibility, selecting oncolytic viruses, identifying biomarkers, and de-risking live virus vaccines. Inhibitors of the proteases that utilize this mechanism may both inhibit viral replication and alleviate suppression of the innate immune responses.


Assuntos
Cisteína Proteases/metabolismo , Vírus da Encefalite Equina Venezuelana/enzimologia , Proteínas Virais/metabolismo , Zika virus/enzimologia , 5'-Nucleotidase/metabolismo , Linhagem Celular , Inibidores de Cisteína Proteinase/farmacologia , Vírus da Encefalite Equina Venezuelana/patogenicidade , Encefalomielite Equina Venezuelana/virologia , Fatores de Transcrição Forkhead/metabolismo , Interações Hospedeiro-Patógeno , Humanos , Peptídeos e Proteínas de Sinalização Intercelular/metabolismo , Proteínas de Membrana/metabolismo , Proteínas do Tecido Nervoso/metabolismo , Proteólise , Replicação Viral/efeitos dos fármacos , Zika virus/patogenicidade , Infecção por Zika virus/virologia
10.
Infect Disord Drug Targets ; 19(1): 2-16, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-29589547

RESUMO

BACKGROUND: B23/nucleophosmin (B23/NPM1) is an abundant multifunctional protein mainly located in the nucleolus but constantly shuttling between the nucleus and cytosol. As a consequence of its constitutive expression, intracellular dynamics and binding capacities, B23/NPM1 interacts with multiple cellular factors in different cellular compartments, but also with viral proteins from both DNA and RNA viruses. B23/NPM1 influences overall viral replication of viruses like HIV, HBV, HCV, HDV and HPV by playing functional roles in different stages of viral replication including nuclear import, viral genome transcription and assembly, as well as final particle formation. Of note, some virus modify the subcellular localization, stability and/or increases B23/NPM1 expression levels on target cells, probably to foster B23/NPM1 functions in their own replicative cycle. RESULTS: This review summarizes current knowledge concerning the interaction of B23/NPM1 with several viral proteins during relevant human infections. The opportunities and challenges of targeting this well-conserved host protein as a potentially new broad antiviral treatment are discussed in detail. Importantly, although initially conceived to treat cancer, a handful of B23/NPM1 inhibitors are currently available to test on viral infection models. CONCLUSION: As B23/NPM1 partakes in key steps of viral replication and some viral infections remain as unsolved medical needs, an appealing idea may be the expedite evaluation of B23/NPM1 inhibitors in viral infections. Furthermore, worth to be addressed is if the up-regulation of B23/NPM1 protein levels that follows persistent viral infections may be instrumental to the malignant transformation induced by virus like HBV and HCV.


Assuntos
Antivirais/farmacologia , Proteínas Nucleares/metabolismo , Proteínas Virais/metabolismo , Viroses/tratamento farmacológico , Replicação Viral/efeitos dos fármacos , Antivirais/uso terapêutico , Humanos , Terapia de Alvo Molecular/métodos , Proteínas Nucleares/antagonistas & inibidores , Nucleofosmina , Regulação para Cima , Viroses/patologia , Viroses/virologia
11.
Acta Crystallogr C Struct Chem ; 73(Pt 12): 1116-1120, 2017 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-29206123

RESUMO

Ganciclovir (GCV; systematic name: 2-amino-9-{[(1,3-dihydroxypropan-2-yl)oxy]methyl}-6,9-dihydro-1H-purin-6-one), C9H13N5O4, an antiviral drug for treating cytomegalovirus infections, has two known polymorphs (Forms I and II), but only the structure of the metastable Form II has been reported [Kawamura & Hirayama (2009). X-ray Struct. Anal. Online, 25, 51-52]. We describe a successful preparation of GCV Form I and its crystal structure. GCV is an achiral molecule in the sense that its individual conformers, which are generally chiral objects, undergo fast interconversion in the liquid state and cannot be isolated. In the crystalline state, GCV exists as two inversion-related conformers in Form I and as a single chiral conformer in Form II. This situation is similar to that observed for glycine, also an achiral molecule, whose α-polymorph contains two inversion-related conformers, while the γ-polymorph contains a single conformer that is chiral. The hydrogen bonds are exclusively intermolecular in Form I, but both inter- and intramolecular in Form II, which accounts for the different molecular conformations in the two polymorphs.


Assuntos
Antivirais/química , Ganciclovir/química , Cristalização , Cristalografia por Raios X , Ligação de Hidrogênio , Conformação Molecular
12.
Front Microbiol ; 8: 2108, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-29163402

RESUMO

Heme oxygenase-1 (HO-1) is an inducible enzyme that is expressed in response to physical and chemical stresses, such as ultraviolet radiation, hyperthermia, hypoxia, reactive oxygen species (ROS), as well as cytokines, among others. Its activity can be positively modulated by cobalt protoporphyrin (CoPP) and negatively by tin protoporphirin (SnPP). Once induced, HO-1 degrades iron-containing heme into ferrous iron (Fe2+), carbon monoxide (CO) and biliverdin. Importantly, numerous products of HO-1 are cytoprotective with anti-apoptotic, anti-oxidant, anti-inflammatory, and anti-cancer effects. The products of HO-1 also display antiviral properties against several viruses, such as the human immunodeficiency virus (HIV), influenza, hepatitis B, hepatitis C, and Ebola virus. Here, we sought to assess the effect of modulating HO-1 activity over herpes simplex virus type 2 (HSV-2) infection in epithelial cells and neurons. There are no vaccines against HSV-2 and treatment options are scarce in the immunosuppressed, in which drug-resistant variants emerge. By using HSV strains that encode structural and non-structural forms of the green fluorescent protein (GFP), we found that pharmacological induction of HO-1 activity with CoPP significantly decreases virus plaque formation and the expression of virus-encoded genes in epithelial cells as determined by flow cytometry and western blot assays. CoPP treatment did not affect virus binding to the cell surface or entry into the cytoplasm, but rather downstream events in the virus infection cycle. Furthermore, we observed that treating cells with a CO-releasing molecule (CORM-2) recapitulated some of the anti-HSV effects elicited by CoPP. Taken together, these findings indicate that HO-1 activity interferes with the replication cycle of HSV and that its antiviral effects can be recapitulated by CO.

13.
Artigo em Inglês | MEDLINE | ID: mdl-26442259

RESUMO

Shikimic acid (SA) is an intermediate of the SA pathway that is present in bacteria and plants. SA has gained great interest because it is a precursor in the synthesis of the drug oseltamivir phosphate (OSF), an efficient inhibitor of the neuraminidase enzyme of diverse seasonal influenza viruses, the avian influenza virus H5N1, and the human influenza virus H1N1. For the purposes of OSF production, SA is extracted from the pods of Chinese star anise plants (Illicium spp.), yielding up to 17% of SA (dry basis content). The high demand for OSF necessary to manage a major influenza outbreak is not adequately met by industrial production using SA from plants sources. As the SA pathway is present in the model bacteria Escherichia coli, several "intuitive" metabolically engineered strains have been applied for its successful overproduction by biotechnological processes, resulting in strains producing up to 71 g/L of SA, with high conversion yields of up to 0.42 (mol SA/mol Glc), in both batch and fed-batch cultures using complex fermentation broths, including glucose as a carbon source and yeast extract. Global transcriptomic analyses have been performed in SA-producing strains, resulting in the identification of possible key target genes for the design of a rational strain improvement strategy. Because possible target genes are involved in the transport, catabolism, and interconversion of different carbon sources and metabolic intermediates outside the central carbon metabolism and SA pathways, as genes involved in diverse cellular stress responses, the development of rational cellular strain improvement strategies based on omics data constitutes a challenging task to improve SA production in currently overproducing engineered strains. In this review, we discuss the main metabolic engineering strategies that have been applied for the development of efficient SA-producing strains, as the perspective of omics analysis has focused on further strain improvement for the production of this valuable aromatic intermediate.

14.
Mem. Inst. Oswaldo Cruz ; 107(3): 317-325, May 2012. graf, tab
Artigo em Inglês | LILACS | ID: lil-624012

RESUMO

The effectiveness of antiviral treatments of chronic hepatitis B has been poorly studied in Brazil. Here, hepatitis B virus (HBV) DNA positivity, drug resistance mutations and their association with HBV genotypes were evaluated in chronically HBV-infected patients under different drug regimens in Brazil. The study involved 129 patients under interferon or nucleos(t)ide analogue therapy for a median treatment time of 12 months. One hundred and five (81%) of these patients were treated with lamivudine (LAM), either in monotherapy or in combination with newer drugs, such as entecavir (ETV) or tenofovir (TDF). High (37.5-100%) rates of HBV DNA positivity were observed with all but one drug regimen (LAM + ETV). However, patients that were treated with ETV alone, TDF alone or with LAM combination therapies had a mean viral load that was 3-4 log lower than patients treated with LAM monotherapy. Of the patients treated with LAM, 47% developed resistance mutations. HBV genotypes A (59.1%), D (30.3%) and F (9.1%) were found. There was no association between the presence of LAM resistance mutations and genotypes, HBeAg status or treatment duration. Nevertheless, the rtM204V mutation was observed more frequently (12/13, 92%) in genotype A than in the others (p = 0.023). Six out of nine isolates that contained the rtM204I mutation belonged to genotype D and half of them displayed a single mutation. Genotype D isolates with the rtM204V variant preferentially displayed a triple mutation, while genotype A preferentially displayed a double mutation (p = 0.04).


Assuntos
Adolescente , Adulto , Idoso , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Adulto Jovem , Antivirais/administração & dosagem , Farmacorresistência Viral/genética , Vírus da Hepatite B/efeitos dos fármacos , Hepatite B Crônica/tratamento farmacológico , Lamivudina/administração & dosagem , Mutação/efeitos dos fármacos , Adenina/administração & dosagem , Adenina/análogos & derivados , Estudos Transversais , DNA Viral/análise , Quimioterapia Combinada/métodos , Genótipo , Guanina/administração & dosagem , Guanina/análogos & derivados , Vírus da Hepatite B/genética , Hepatite B Crônica/virologia , Mutação/genética , Organofosfonatos/administração & dosagem , Carga Viral
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