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Einstein (Säo Paulo) ; 13(2): 221-225, Apr-Jun/2015. tab
Artigo em Inglês | LILACS | ID: lil-751414


ABSTRACT Objective: To assess adherence of the prescribing physicians in a private cancer care center to the American Society of Clinical Oncology guideline for antiemetic prophylaxis, in the first cycle of antineoplastic chemotherapy. Methods: A total of 139 chemotherapy regimens, of 105 patients, were evaluated retrospectively from 2011 to 2013. Results: We observed 78% of non-adherence to the guideline rate. The main disagreements with the directive were the prescription of higher doses of dexamethasone and excessive use of 5-HT3 antagonist for low risk emetogenic chemotherapy regimens. On univariate analysis, hematological malignancies (p=0.005), the use of two or more chemotherapy (p=0.05) and high emetogenic risk regimes (p=0.012) were factors statistically associated with greater adherence to guidelines. Treatment based on paclitaxel was the only significant risk factor for non-adherence (p=0.02). By multivariate analysis, the chemotherapy of high emetogenic risk most correlated with adherence to guideline (p=0.05). Conclusion: We concluded that the adherence to guidelines is greater if the chemotherapy regime has high emetogenic risk. Educational efforts should focus more intensely on the management of chemotherapy regimens with low and moderate emetogenic potential. Perhaps the development of a computer generated reminder may improve the adherence to guidelines. .

RESUMO Objetivo: Avaliar a adesão dos médicos prescritores, de um centro privado especializado em oncologia, à diretriz de antiêmese profilática da American Society of Clinical Oncology, no primeiro ciclo de quimioterapia antineoplásica. Métodos: Foram avaliados retrospectivamente 139 esquemas de quimioterapia, de 105 pacientes, tratados no período de 2011 a 2013. Resultados: Foram observados 78% de taxa de não adesão à diretriz. As principais discordâncias com a diretriz foram prescrição de doses mais elevadas de dexametasona e uso excessivo de antagonista 5-HT3 para regimes de quimioterapia de risco emetogênico baixo. Pela análise univariada, malignidades hematológicas (p=0,005), uso de dois ou mais quimioterápicos (p=0,05) e regimes de alto risco emetogênico (p=0,012) foram fatores estatisticamente associados a maior adesão à diretriz. O tratamento baseado em paclitaxel foi o único fator estatisticamente significativo para a não adesão (p=0,02). Pela análise multivariada, a quimioterapia de alto risco emetogênico apresentou maior correlação com a adesão à diretriz (p=0,05). Conclusão: Houve maior aderência para a quimioterapia de alto risco emetogênico. Esforços educacionais devem se concentrar mais intensamente na gestão de regimes de quimioterapia com potencial emetogênico baixo e moderado. Talvez o desenvolvimento de lembretes gerados por sistemas informatizados possa melhorar a aderência à diretriz. .

Animais , Humanos , Camundongos , Dano ao DNA , Reparo de DNA por Recombinação , Ubiquitina-Proteína Ligases/química , Motivos de Aminoácidos , Sequência de Aminoácidos , Proteína BRCA1/antagonistas & inibidores , Linhagem Celular , Quebra Cromossômica , Sequência Conservada , Reparo do DNA , Proteínas de Ligação a DNA/antagonistas & inibidores , Desoxirribonucleases/metabolismo , Histonas/metabolismo , Estrutura Terciária de Proteína , Ubiquitinação , Ubiquitina-Proteína Ligases/metabolismo
Arch. endocrinol. metab. (Online) ; 59(3): 245-251, 06/2015. tab, graf
Artigo em Inglês | LILACS | ID: lil-751309


Objective Evaluate the effect of glycemic index (GI) on biochemical parameters, food intake, energy metabolism, anthropometric measures and body composition in overweight subjects.Materials and methods Simple blind study, in which nineteen subjects were randomly assigned to consume in the laboratory two daily low GI (n = 10) or high GI (n = 9) meals, for forty-five consecutive days. Habitual food intake was assessed at baseline. Food intake, anthropometric measures and body composition were assessed at each 15 days. Energy metabolism and biochemical parameters were evaluated at baseline and the end of the study.Results Low GI meals increased fat oxidation, and reduced waist circumference and HOMA-IR, while high GI meals increased daily dietary fiber and energy intake compared to baseline. There was a higher reduction on waist circumference and body fat, and a higher increase on postprandial fat oxidation in response to the LGI meals than after high GI meals. High GI meals increased fasting respiratory coefficient compared to baseline and low GI meals.Conclusion The results of the present study showed that the consumption of two daily low GI meals for forty-five consecutive days has a positive effect on obesity control, whereas, the consumption of high GI meals result has the opposite effect. Arch Endocrinol Metab. 2015;59(3):245-51.

Proteínas de Bactérias/química , Escherichia coli/enzimologia , Proteínas de Membrana/química , Fenilalanina/química , Motivos de Aminoácidos , Sequência de Aminoácidos , Proteínas de Bactérias/genética , Proteínas de Bactérias/metabolismo , Quimiotaxia , Sequência Conservada , Dimerização , Escherichia coli/química , Escherichia coli/genética , Escherichia coli/fisiologia , Dados de Sequência Molecular , Proteínas de Membrana/genética , Proteínas de Membrana/metabolismo , Conformação Proteica , Fenilalanina/genética , Fenilalanina/metabolismo
Mem. Inst. Oswaldo Cruz ; 109(8): 1045-1049, 12/2014. tab
Artigo em Inglês | LILACS | ID: lil-732608


Helicobacter pylori infection is one of the most common infections worldwide and is associated with gastric diseases. Virulence factors such as VacA and CagA have been shown to increase the risk of these diseases. Studies have suggested a causal role of CagA EPIYA-C in gastric carcinogenesis and this factor has been shown to be geographically diverse. We investigated the number of CagA EPIYA motifs and the vacA i genotypes in H. pylori strains from asymptomatic children. We included samples from 40 infected children (18 females and 22 males), extracted DNA directly from the gastric mucus/juice (obtained using the string procedure) and analysed the DNA using polymerase chain reaction and DNA sequencing. The vacA i1 genotype was present in 30 (75%) samples, the i2 allele was present in nine (22.5%) samples and both alleles were present in one (2.5%) sample. The cagA-positive samples showed distinct patterns in the 3’ variable region of cagA and 18 of the 30 (60%) strains contained 1 EPIYA-C motif, whereas 12 (40%) strains contained two EPIYA-C motifs. We confirmed that the studied population was colonised early by the most virulent H. pylori strains, as demonstrated by the high frequency of the vacA i1 allele and the high number of EPIYA-C motifs. Therefore, asymptomatic children from an urban community in Fortaleza in northeastern Brazil are frequently colonised with the most virulent H. pylori strains. .

Adolescente , Criança , Feminino , Humanos , Masculino , Antígenos de Bactérias/genética , Proteínas de Bactérias/genética , Helicobacter pylori , Infecções por Helicobacter/microbiologia , Neoplasias Gástricas/microbiologia , Alelos , Motivos de Aminoácidos , Infecções Assintomáticas , Antígenos de Bactérias/metabolismo , Proteínas de Bactérias/metabolismo , Brasil/epidemiologia , Doenças Endêmicas , Detecção Precoce de Câncer/métodos , Genótipo , Helicobacter pylori/genética , Helicobacter pylori/patogenicidade , Fosforilação , Fatores de Risco , População Urbana , Fatores de Virulência/genética , Virulência/genética
Braz. j. med. biol. res ; 47(10): 834-841, 10/2014. tab, graf
Artigo em Inglês | LILACS | ID: lil-722173


In this study, biomarkers and transcriptional factor motifs were identified in order to investigate the etiology and phenotypic severity of Down syndrome. GSE 1281, GSE 1611, and GSE 5390 were downloaded from the gene expression ominibus (GEO). A robust multiarray analysis (RMA) algorithm was applied to detect differentially expressed genes (DEGs). In order to screen for biological pathways and to interrogate the Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway database, the database for annotation, visualization, and integrated discovery (DAVID) was used to carry out a gene ontology (GO) function enrichment for DEGs. Finally, a transcriptional regulatory network was constructed, and a hypergeometric distribution test was applied to select for significantly enriched transcriptional factor motifs. CBR1, DYRK1A, HMGN1, ITSN1, RCAN1, SON, TMEM50B, and TTC3 were each up-regulated two-fold in Down syndrome samples compared to normal samples; of these, SON and TTC3 were newly reported. CBR1, DYRK1A, HMGN1, ITSN1, RCAN1, SON, TMEM50B, and TTC3 were located on human chromosome 21 (mouse chromosome 16). The DEGs were significantly enriched in macromolecular complex subunit organization and focal adhesion pathways. Eleven significantly enriched transcription factor motifs (PAX5, EGR1, XBP1, SREBP1, OLF1, MZF1, NFY, NFKAPPAB, MYCMAX, NFE2, and RP58) were identified. The DEGs and transcription factor motifs identified in our study provide biomarkers for the understanding of Down syndrome pathogenesis and progression.

Animais , Humanos , Camundongos , Ratos , Motivos de Aminoácidos/genética , Biologia Computacional/métodos , Síndrome de Down/genética , Redes Reguladoras de Genes/genética , Fatores de Transcrição/análise , Algoritmos , Biomarcadores/análise , Bases de Dados Genéticas , Síndrome de Down/etiologia , Expressão Gênica , Ontologia Genética , Anotação de Sequência Molecular/métodos , Fenótipo , Análise Serial de Proteínas/métodos , Regulação para Cima/genética
Braz. j. med. biol. res ; 47(5): 369-375, 02/05/2014. tab, graf
Artigo em Inglês | LILACS | ID: lil-709431


To investigate signal regulation models of gastric cancer, databases and literature were used to construct the signaling network in humans. Topological characteristics of the network were analyzed by CytoScape. After marking gastric cancer-related genes extracted from the CancerResource, GeneRIF, and COSMIC databases, the FANMOD software was used for the mining of gastric cancer-related motifs in a network with three vertices. The significant motif difference method was adopted to identify significantly different motifs in the normal and cancer states. Finally, we conducted a series of analyses of the significantly different motifs, including gene ontology, function annotation of genes, and model classification. A human signaling network was constructed, with 1643 nodes and 5089 regulating interactions. The network was configured to have the characteristics of other biological networks. There were 57,942 motifs marked with gastric cancer-related genes out of a total of 69,492 motifs, and 264 motifs were selected as significantly different motifs by calculating the significant motif difference (SMD) scores. Genes in significantly different motifs were mainly enriched in functions associated with cancer genesis, such as regulation of cell death, amino acid phosphorylation of proteins, and intracellular signaling cascades. The top five significantly different motifs were mainly cascade and positive feedback types. Almost all genes in the five motifs were cancer related, including EPOR, MAPK14, BCL2L1, KRT18, PTPN6, CASP3, TGFBR2, AR, and CASP7. The development of cancer might be curbed by inhibiting signal transductions upstream and downstream of the selected motifs.

Humanos , Mineração de Dados , Redes Reguladoras de Genes , Transdução de Sinais/genética , Neoplasias Gástricas/genética , Motivos de Aminoácidos/genética , Morte Celular , Carcinogênese/genética , Retroalimentação Fisiológica , Regulação da Expressão Gênica , Ontologia Genética , Anotação de Sequência Molecular , Fosforilação , Neoplasias Gástricas/metabolismo
Mem. Inst. Oswaldo Cruz ; 108(6): 735-740, set. 2013. tab
Artigo em Inglês | LILACS | ID: lil-685483


Typical human immunodeficiency virus-1 subtype B (HIV-1B) sequences present a GPGR signature at the tip of the variable region 3 (V3) loop; however, unusual motifs harbouring a GWGR signature have also been isolated. Although epidemiological studies have detected this variant in approximately 17-50% of the total infections in Brazil, the prevalence of B"-GWGR in the southernmost region of Brazil is not yet clear. This study aimed to investigate the C2-V3 molecular diversity of the HIV-1B epidemic in southernmost Brazil. HIV-1 seropositive patients were ana-lysed at two distinct time points in the state of Rio Grande do Sul (RS98 and RS08) and at one time point in the state of Santa Catarina (SC08). Phylogenetic analysis classified 46 individuals in the RS98 group as HIV-1B and their molecular signatures were as follows: 26% B"-GWGR, 54% B-GPGR and 20% other motifs. In the RS08 group, HIV-1B was present in 32 samples: 22% B"-GWGR, 59% B-GPGR and 19% other motifs. In the SC08 group, 32 HIV-1B samples were found: 28% B"-GWGR, 59% B-GPGR and 13% other motifs. No association could be established between the HIV-1B V3 signatures and exposure categories in the HIV-1B epidemic in RS. However, B-GPGR seemed to be related to heterosexual individuals in the SC08 group. Our results suggest that the established B"-GWGR epidemics in both cities have similar patterns, which is likely due to their geographical proximity and cultural relationship.

Feminino , Humanos , Masculino , Infecções por HIV/epidemiologia , Infecções por HIV/transmissão , Soropositividade para HIV/virologia , HIV-1 , Motivos de Aminoácidos , Sequência de Aminoácidos , Transfusão de Sangue/efeitos adversos , Brasil/epidemiologia , Usuários de Drogas/estatística & dados numéricos , Heterossexualidade , HIV-1 , Homossexualidade Masculina , Epidemiologia Molecular , Filogenia , Prevalência , Parceiros Sexuais , Alinhamento de Sequência/estatística & dados numéricos
Braz. j. infect. dis ; 16(3): 250-255, May-June 2012. tab
Artigo em Inglês | LILACS | ID: lil-638558


OBJECTIVE: This study aimed to determine the natural prevalence of variants of tyrosine-methionine-aspartic acid-aspartic acid (YMDD) motif in patients with chronic hepatitis B (CHB), and to explore its relation with demographic and clinical features, hepatitis B virus (HBV) genotypes, and HBV DNA levels. METHODS: A total of 1,042 antiviral treatment naïve CHB patients (including with lamivudine [LAM]) in the past year were recruited from outpatient and inpatient departments of six centers from December 2008 to June 2010. YMDD variants were analyzed using the HBV drug resistance line probe assay (Inno-Lipa HBV-DR). HBV genotypes were detected with polymerase chain reaction (PCR) microcosmic nucleic acid cross-ELISA, and HBV deoxyribonucleic acid (DNA) was quantitated with real-time PCR. All serum samples underwent tests for HBV, HCV, and HDV with ELISA. RESULTS: YMDD variants were detected in 23.3% (243/1042) of CHB patients. YMDD mutation was accompanied by L180M mutation in 154 (76.9%) patients. Both wild-type HBV and YMDD variant HBV were present in 231 of 243 patients. Interestingly, 12 patients had only YIDD and/or YVDD variants without wild YMDD motif. In addition, 27.2% (98/359) of HbeAg-positive patients had YMDD mutations, which was higher than that in HbeAg-negative patients (21.2%, 145/683). The incidence of YMDD varied among patients with different HBV genotypes, but the difference was not significant. Moreover, the incidence of YMDD in patients with high HBV DNA level was significantly higher than that in those with low HBV DNA level. CONCLUSION: Mutation of YMDD motif was detectable at a high rate in CHB patients in this study. The incidence of YMDD may be correlated with HBeAg and HBV DNA level.

Adulto , Feminino , Humanos , Masculino , Antivirais/uso terapêutico , Ácido Aspártico/genética , Vírus da Hepatite B/genética , Hepatite B Crônica/tratamento farmacológico , Metionina/genética , Mutação/genética , Tirosina/genética , Motivos de Aminoácidos/efeitos dos fármacos , Motivos de Aminoácidos/genética , DNA Viral/análise , Genótipo , Vírus da Hepatite B/efeitos dos fármacos , Hepatite B Crônica/virologia , Reação em Cadeia da Polimerase
Biomédica (Bogotá) ; 32(1): 23-31, ene.-mar. 2012. ilus, tab
Artigo em Espanhol | LILACS | ID: lil-639808


Introduction. It is known that polymorphisms in C-terminal region of CagA influence gastric disease development on Helicobacter pylori infection. Additionally, the geographic distribution of these polymorphisms has been associated with the appearance of more severe gastroduodenal pathologies. Objective. To determine the CagA phosphorylation motifs pattern (EPIYA pattern) in Cuban H. pylori isolates, and to study its association with patient´s pathologies. Materials and methods. DNAs from 95 H. pylori cagA-positive strains were used to amplify the 3´ variable region of cagA gene by PCR using two different strategies. Additionally, new primers were designed to identify either Western or Eastern CagAEPIYA motiftype by PCR. To confirm the PCR results, PCR products from 14 representative isolates were purified and sequenced Results. The distribution of the EPIYA motif found was: 2 AB (2.1 %), 1 AC (1.1 %), 1 BC (1.1 %), 70 ABC (73.6 %), 19 ABCC (20 %), and 2 ABCCC (2.1 %). Sequencing analysis confirmed the PCR classification in the 14 studied strains and showed three strains with unusual nucleotide sequences, not reported before. Distribution of the EPIYA-ABC pattern was equivalent in all pathologies (78.9 % in gastric ulcer, 72.5 % in duodenal ulcer and 72.2 % in non-ulcer dyspepsia). Conclusion. The PCR results using the new primers confirmed that all studied strains carried the Western CagA type. No specific EPIYA motif was associated with peptic ulcer. This is the first report that shows EPIYA motif distribution in H. pylori isolates from the Caribbean region.

Introducción. Se sabe que el polimorfismo en la región C-terminal de la citotoxina asociada al gen A (CagA) influye en el desarrollo de la enfermedad gástrica durante la infección por Helicobacter pylori. Objetivo. Determinar el número y el tipo de patrones de fosforilación de CagA (patrón EPIYA) en aislamientos cubanos de H. pylori, y estudiar su asociación con las enfermedades gástricas. Materiales y métodos. Se empleó el ADN de 95 cepas de H. pylori positivas paraCagA, para amplificar la región 3´ variable del gen cagA por PCR, mediante el empleo de diferentes estrategias. Además, se diseñaron nuevos cebadores para clasificar por PCR los aislamientos según el tipo de CagA, occidental o del este asiático. Los productos de PCR obtenidos de 14 aislamientos representativos se purificaron y secuenciaron para confirmar los resultados de la PCR. Resultados. La distribución de los patrones EPIYA encontrada, fue: 2 AB (2,1 %), 1 AC (1,1 %), 1 BC (1,1 %), 70 ABC (73,6 %), 19 ABCC (20 %), y 2 ABCCC (2,1 %). El análisis de la secuenciación confirmó las clasificaciones hechas por PCR en las 14 cepas estudiadas y demostró tres cepas con secuencias únicas de nucleótídos, no reportadas anteriormente. La distribución del patrón EPIYA-ABC fue equivalente en todas las enfermedades encontradas: 78,9 % en úlcera gástrica, 72,5 % en úlcera duodenal y 72,2 % en dispepsia no ulcerada. Conclusión. La mayoría de los aislamientos cubanos presentaron las combinaciones de motivos EPIYA menos virulentas (ABC). Los resultados del empleo de los nuevos cebadores y el análisis de la secuenciación, confirmaron que todas las cepas estudiadas portaban el gen cagA de tipo occidental. Ninguno de los patrones específicos de EPIYA se asoció con úlcera péptica. Este es el primer reporte que muestra la distribución de los motivos EPIYA en los aislamientos de H. pylori de la región del Caribe.

Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Adulto Jovem , Antígenos de Bactérias/química , Proteínas de Bactérias/química , Gastrite/microbiologia , Infecções por Helicobacter/microbiologia , Helicobacter pylori/genética , Processamento de Proteína Pós-Traducional , Úlcera Péptica/microbiologia , Motivos de Aminoácidos , Sequência de Aminoácidos , Antígenos de Bactérias/genética , Antígenos de Bactérias/metabolismo , Proteínas de Bactérias/genética , Proteínas de Bactérias/metabolismo , Cuba/epidemiologia , Primers do DNA , DNA Bacteriano/genética , Dispepsia/microbiologia , Infecções por Helicobacter/epidemiologia , Helicobacter pylori/isolamento & purificação , Helicobacter pylori/patogenicidade , Dados de Sequência Molecular , Fosforilação , Reação em Cadeia da Polimerase , /metabolismo , Alinhamento de Sequência , Homologia de Sequência de Aminoácidos , Virulência
Rev. colomb. psiquiatr ; 41(1): 217-228, ene.-abr. 2012. ilus, graf, tab
Artigo em Espanhol | LILACS | ID: lil-639942


Introducción: En psiquiatría de enlace se logra obtener una visión integral del tratamiento y de las necesidades de cada paciente prestando especial atención a las interacciones medicamentosas y a las contraindicaciones. Algunos casos particulares motivaron la descripción, reporte y revisión bibliográfica acerca de otras posibles aplicaciones de fármacos antagonistas de los recetores 5HT2A y 3, particularmente mirtazapina y olanzapina, en síndrome de hiperalgesia, tinitus y leucoencefalopatía multifocal progresiva por virus JC. Método: reporte de casos. Resultados y Conclusiones: Se describen los casos de tres pacientes en los cuales fue necesario usar mirtazapina y olanzapina no solo para el control de los síntomas psiquiátricos (afectivos, comportamentales y trastorno del sueño), sino también como coadyuvantes en las patologías de base de cada paciente. El uso de cualquier medicamento en psiquiatría de enlace debe tener en cuenta el contexto del paciente, la comorbilidad, las contraindicaciones y las interacciones farmacológicas para garantizar un desenlace positivo, además de promover el trabajo multidisciplinario entre especialistas.

Introduction: In liaison psychiatry it is possible to get an integral view of patient's treatment and needs, paying special attention to pharmacological interactions and contraindications. Some particular cases motivated the description, report and review about other possible applications of 5HT2A and 5HT3 antagonist, particularly Mirtazapine and Olanzapine, in hyperalgesia syndrome, tinnitus and Progressive Multifocal Leukoencephalopathy by JC virus. Method: Cases report. Results: We describe 3 cases of patients in which Mirtazapine and Olanzapine were necessary not only to control psychiatric symptoms (affective / behavioral symptoms and insomnia) but to act as adjuvant therapy in axis III diseases. The use of any drug in psychiatry must take in to account the context of the patient, the presence of comorbidity, contraindications and pharmacological interactions so as to grant a positive outcome also promoting the multidisciplinary work between specialists.

Humanos , Proteínas Adaptadoras de Transdução de Sinal/metabolismo , Núcleo Celular/metabolismo , Cisteína/metabolismo , Neurônios/metabolismo , Tiorredoxinas/metabolismo , Fatores de Transcrição/metabolismo , Motivos de Aminoácidos , Proteínas Adaptadoras de Transdução de Sinal/genética , Linhagem Celular Tumoral , Cisteína/química , Citoplasma/metabolismo , Dissulfetos/química , Perfilação da Expressão Gênica , Regulação da Expressão Gênica , Anotação de Sequência Molecular , Dados de Sequência Molecular , Mutação , Neurônios/citologia , Oxirredução , Mapeamento de Interação de Proteínas , Transdução de Sinais , Transcrição Genética , Tiorredoxinas/genética , Fatores de Transcrição/genética
Braz. j. med. biol. res ; 40(12): 1605-1614, Dec. 2007. graf, tab
Artigo em Inglês | LILACS | ID: lil-466741


Given the loss of therapeutic efficacy associated with the development of resistance to lamivudine (LMV) and the availability of new alternative treatments for chronic hepatitis B patients, early detection of viral genotypic resistance could allow the clinician to consider therapy modification before viral breakthrough and biochemical relapse occur. To this end, 28 LMV-treated patients (44 ± 12 years; 24 men), on their first therapy schedule, were monitored monthly at four Brazilian centers for the emergence of drug resistance using the reverse hybridization-based INNO-LiPA HBV DR assay and occasionally sequencing (two cases). Positive viral responses (HBV DNA clearance) after 6, 12, and 18 months of therapy were achieved by 57, 68, and 53 percent of patients, while biochemical responses (serum alanine aminotransferase normalization) were observed in 82, 82, and 53 percent of cases. All viral breakthrough cases (N = 8) were related to the emergence of YMDD variants observed in 7, 21, and 35 percent of patients at 6, 12, and 18 months, respectively. The emergence of these variants was not associated with viral genotype, HBeAg expression status, or pretreatment serum alanine aminotransferase levels. The detection of resistance-associated mutations was observed before the corresponding biochemical flare (41 ± 14 and 60 ± 15 weeks) in the same individuals. Then, if highly sensitive LMV drug resistance testing is carried out at frequent and regular intervals, the relatively long period (19 ± 2 weeks) between the emergence of viral resistance and the onset of biochemical relapse can provide clinicians with ample time to re-evaluate drug therapy.

Adulto , Idoso , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Motivos de Aminoácidos/genética , Farmacorresistência Viral/genética , Vírus da Hepatite B/genética , Hepatite B Crônica/tratamento farmacológico , Lamivudina/uso terapêutico , Inibidores da Transcriptase Reversa/uso terapêutico , Alanina Transaminase/sangue , DNA Viral/sangue , Seguimentos , Antígenos E da Hepatite B/sangue , Vírus da Hepatite B/efeitos dos fármacos , Vírus da Hepatite B/imunologia , Hepatite B Crônica/imunologia , Hepatite B Crônica/virologia , Mutação/genética , Reação em Cadeia da Polimerase , Estudos Prospectivos
NOVA publ. cient ; 1(1): 65-71, ene.-dic. 2003. ilus, tab, graf
Artigo em Espanhol | LILACS | ID: lil-438620


Ante el incremento creciente de estructuras tridimensionales (3D) de proteínas determinadas por rayos X y tecnologías de NMR, así como de estructuras obtenidas mediante métodos computacionales, resulta necesaria la utilización de métodos automatizados para obtener anotaciones iniciales. Hemos desarrollado un nuevo método para reconocer sitios en estructuras tridimensionales de proteínas. Este método está basado en un algoritmo previamente informado para crear descripciones de microambientes proteicos, utilizando propiedades físicas y químicas muy específicas. El método de reconocimiento tiene 3 entradas: 1. Un juego de sitios que comparten alguna función estructural o funcional; 2. Un juego de sitios que no comparten funciones estructurales o funcionales; 3. Un sólo sitio para análisis. Una máquina clasificadora con vector de soporte utiliza detalles del vector, donde cada componente representa una propiedad en volumen dado. La validación contra tests independientes muestra que esta prueba de reconocimiento tiene una alta sensibilidad y especificidad. También describimos los resultados de examinar 4 proteínas de unión a calcio (y con el calcio removido) utilizando una rejilla tridimensional de puntos de prueba en un espacio de 1.25Ao. Nuestros resultados muestran que descripciones basadas en propiedades con máquinas de soporte de vectores pueden ser utilizadas para el reconocimiento de sitios de proteínas en estructuras no anotadas.

Algoritmos , Motivos de Aminoácidos