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1.
Biol. Res ; 56: 4-4, 2023. ilus, graf
Artigo em Inglês | LILACS | ID: biblio-1420302

RESUMO

BACKGROUND: Spermatogonial stem cells (SSCs) are critical for sustaining spermatogenesis. Even though several regulators of SSC have been identified in rodents, the regulatory mechanism of SSC in humans has yet to be discovered. METHODS: To explore the regulatory mechanisms of human SSCs, we analyzed publicly available human testicular single-cell sequencing data and found that Ankyrin repeat and SOCS box protein 9 (ASB9) is highly expressed in SSCs. We examined the expression localization of ASB9 using immunohistochemistry and overexpressed ASB9 in human SSC lines to explore its role in SSC proliferation and apoptosis. Meanwhile, we used immunoprecipitation to find the target protein of ASB9 and verified its functions. In addition, we examined the changes in the distribution of ASB9 in non-obstructive azoospermia (NOA) patients using Western blot and immunofluorescence. RESULTS: The results of uniform manifold approximation and projection (UMAP) clustering and pseudotime analysis showed that ASB9 was highly expressed in SSCs, and its expression gradually increased during development. The immunohistochemical and dual-color immunofluorescence results displayed that ASB9 was mainly expressed in nonproliferating SSCs. Overexpression of ASB9 in the SSC line revealed significant inhibition of cell proliferation and increased apoptosis. We predicted the target proteins of ASB9 and verified that hypoxia-inducible factor 1-alpha inhibitor (HIF1AN), but not creatine kinase B-type (CKB), has a direct interaction with ASB9 in human SSC line using protein immunoprecipitation experiments. Subsequently, we re-expressed HIF1AN in ASB9 overexpressing cells and found that HIF1AN reversed the proliferative and apoptotic changes induced by ASB9 overexpression. In addition, we found that ABS9 was significantly downregulated in some NOA patients, implying a correlation between ASB9 dysregulation and impaired spermatogenesis. CONCLUSION: ASB9 is predominantly expressed in human SSCs, it affects the proliferation and apoptotic process of the SSC line through HIF1AN, and its abnormal expression may be associated with NOA.


Assuntos
Humanos , Masculino , Testículo/metabolismo , Ubiquitina-Proteína Ligases/metabolismo , Proteínas Repressoras/metabolismo , Espermatogênese/fisiologia , Ubiquitinas/metabolismo , Linhagem Celular , Apoptose , Proliferação de Células , Proteínas Supressoras da Sinalização de Citocina/metabolismo , Oxigenases de Função Mista/metabolismo
2.
J. coloproctol. (Rio J., Impr.) ; 42(3): 193-202, July-Sept. 2022. tab, graf, ilus
Artigo em Inglês | LILACS | ID: biblio-1421988

RESUMO

Background: It is important to detect novel biomarkers responsible for the progression and spread of colorectal cancer (CRC) to better evaluate the prognosis of the patients, provide better management, and foster the development of therapeutic targets. In humans, pyrroline-5-carboxylate reductase 2 (PYCR2) is encoded on chromosome 1q42.12, and its metabolic activity has been linked to oncogenesis in many cancers. Zinc finger and broad-complex, tramtrack, and bric-à-brac (BTB) domain-containing protein 18 (ZBTB18), a zinc finger transcriptional repressor, has been found to have a tumor-suppressor role and to be methylated in CRCs. To date, the prognostic roles of PYCR2 and ZBTB18 in CRC patients have not been thoroughly studied. Objective: To evaluate the tissue protein expression of PYCR2 and ZBTB18 in CRC and adjacent non-neoplastic intestinal tissues, to detect their roles in CRC carcinogenesis, progression and metastases. Patients and methods: After applying the inclusion criteria, 60 CRC patients were included in the study. Tissue samples from the tumor and the adjacent non-neoplastic tissues were stained with PYCR2 and ZBTB18. The patients were followed up for about 30 months (range: 10 to 36 months). We performed a correlation regarding the expression of the markers, and clinicopathological and prognostic parameters. Results Upregulation of PYCR2 and downregulation of ZBTB18 were found to be higher in CRC tissue than in the adjacent non-neoplastic colonic mucosa (p = 0.026 and p < 0.001 respectively). High expression of PYCR2 and low expression of ZBTB18 were positively correlated with large tumor size, higher tumor grade, advanced tumor stage, presence of spread to lymph nodes, and presence of distant metastases (p < 0.001). High PYCR2 and low ZBTB18 expressions were significantly associated with poor response to therapy (p = 0.008 and 0.0.17 respectively), as well as high incidence of progression and recurrence (p = 0.005), and unfavorable overall survival (OS) rates (p = 0.001). Conclusion: High expression of PYCR2 and low expression of ZBTB18 were independent predictors of CRC, progression, poor prognosis and unfavorable patient OS and progression-free survival (PFS) rates. (AU)


Assuntos
Humanos , Masculino , Feminino , Adulto , Pessoa de Meia-Idade , Idoso , Idoso de 80 Anos ou mais , Pirrolina Carboxilato Redutases , Neoplasias Retais/terapia , Proteínas Repressoras , Neoplasias do Colo/terapia , Prognóstico , Carcinoma , Resultado do Tratamento , Estadiamento de Neoplasias
3.
Biol. Res ; 55: 7-7, 2022. ilus, graf
Artigo em Inglês | LILACS | ID: biblio-1383911

RESUMO

BACKGROUND: Aerobic metabolism generates reactive oxygen species that may cause critical harm to the cell. The aim of this study is the characterization of the stress responses in the model aromatic degrading bacterium Paraburkholderia xenovorans LB400 to the oxidizing agents paraquat and H 2 O2. METHODS: Antioxidant genes were identified by bioinformatic methods in the genome of P. xenovorans LB400, and the phylogeny of its OxyR and SoxR transcriptional regulators were studied. Functionality of the transcriptional regulators from strain LB400 was assessed by complementation with LB400 SoxR of null mutant P. aeruginosa ΔsoxR, and the construction of P. xenovorans pIZ oxyR that overexpresses OxyR. The effects of oxidizing agents on P. xenovorans were studied measuring bacterial susceptibility, survival and ROS formation after exposure to paraquat and H 2 O2. The effects of these oxidants on gene expression (qRT PCR) and the proteome (LC-MS/MS) were quantified. RESULTS: P. xenovorans LB400 possesses a wide repertoire of genes for the antioxidant defense including the oxyR , ahpC , ahpF , kat , trxB , dpsA and gorA genes, whose orthologous genes are regulated by the transcriptional regulator OxyR in E. coli . The LB400 genome also harbors the soxR, fumC , acnA , sodB , fpr and fldX genes, whose orthologous genes are regulated by the transcriptional regulator SoxR in E. coli . The functionality of the LB400 soxR gene was confirmed by complementation of null mutant P. aeruginosa Δ soxR . Growth, susceptibility, and ROS formation assays revealed that LB400 cells were more susceptible to paraquat than H2O2. Transcriptional analyses indicated the upregulation of the oxyR , ahpC1 , katE and ohrB genes in LB400 cells after exposure to H2O2, whereas the oxyR , fumC , ahpC1 , sodB1 and ohrB genes were induced in presence of paraquat. Proteome analysis revealed that paraquat induced the oxidative stress response proteins AhpCF and DpsA, the universal stress protein UspA and the RNA chaperone CspA. Both oxidizing agents induced the Ohr protein, which is involved in organic peroxide resistance. Notably, the overexpression of the LB400 oxyR gene in P. xenovorans significantly decreased the ROS formation and the susceptibility to paraquat, suggesting a broad OxyR regulated antioxidant response. CONCLUSIONS: This study showed that P. xenovorans LB400 possess a broad range oxidative stress response, which explain the high resistance of this strain to the oxidizing compounds paraquat and H2O2.


Assuntos
Regulação Bacteriana da Expressão Gênica , Proteínas de Escherichia coli/genética , Proteínas de Escherichia coli/metabolismo , Oxirredução , Proteínas Repressoras/genética , Proteínas Repressoras/metabolismo , Proteínas de Bactérias/genética , Proteínas de Bactérias/metabolismo , Cromatografia Líquida , Estresse Oxidativo , Burkholderiaceae , Escherichia coli/genética , Espectrometria de Massas em Tandem , Peróxido de Hidrogênio/farmacologia
4.
Rev. invest. clín ; 73(1): 17-22, Jan.-Feb. 2021. tab, graf
Artigo em Inglês | LILACS | ID: biblio-1289740

RESUMO

ABSTRACT Background: Decreased levels of repressor element-1 silencing transcription (REST) factor in the brain, plasma, and neuron-derived exosomes are associated with Alzheimer’s disease (AD). Objective: The objective of the study was to test the viability of serum REST as a possible blood-based biomarker for AD, comparing serum REST levels in AD patients from a National Institute of Health in Mexico City (with different levels of severity and comorbidities), with elderly controls (EC) and young controls (YC). Methods: We used an enzyme-linked immunosorbent assay to determine serum REST levels in AD patients (n = 28), EC (n = 19), and YC (n = 24); the AD patients were classified by dementia severity and comorbidities (depression and microangiopathy) using clinimetric tests and magnetic resonance imaging. Results: Mean serum REST levels did not differ between AD patients, EC, and YC. The severity of AD and the presence of depression or microangiopathy were not associated with serum REST levels. Conclusion: Our results differ from previously published patterns found for plasma and cerebral REST levels. Free serum REST levels may not be a viable AD blood-based biomarker. (REV INVEST CLIN. 2021;73(1):17-22)


Assuntos
Humanos , Masculino , Feminino , Idoso , Idoso de 80 Anos ou mais , Adulto Jovem , Proteínas Repressoras/sangue , Doença de Alzheimer/sangue , Biomarcadores/sangue , Estudos de Casos e Controles , Fatores Etários , México
5.
Electron. j. biotechnol ; 46: 8-13, jul. 2020. tab, graf
Artigo em Inglês | LILACS | ID: biblio-1223212

RESUMO

BACKGROUND: Poly-3-hydroxybutyrate (PHB) can be efficiently produced in recombinant Escherichia coli by the overexpression of an operon (NphaCAB) encoding PHB synthetase. Strain improvement is considered to be one of critical factors to lower the production cost of PHB in recombinant system. In this study, one of key regulators that affect the cell growth and PHB content was confirmed and analyzed. RESULT: S17-3, a mutant E. coli strain derived from S17-1, was found to be able to achieve high cell density when expressing NphaCAB with the plasmid pBhya-CAB. Whole genome sequencing of S17-3 revealed genetic alternations on the upstream regions of csrA, encoding a global regulator cross-talking between stress response, catabolite repression and other metabolic activities. Deletion of csrA or expression of mutant csrA resulted in improved cell density and PHB content. CONCLUSION: The impact of gene deletion of csrA was determined, dysfunction of the regulators improved the cell density of recombinant E. coli and PHB production, however, the detail mechanism needs to be further clarified.


Assuntos
Escherichia coli/metabolismo , Hidroxibutiratos/metabolismo , Proteínas Repressoras/genética , Biopolímeros/genética , Proteínas Recombinantes , Proteínas de Ligação a RNA/genética , Deleção de Genes , Proteínas de Escherichia coli/genética , Escherichia coli/genética , Engenharia Metabólica , Ligases/metabolismo
6.
São Paulo med. j ; 137(3): 255-261, May-June 2019. tab, graf
Artigo em Inglês | LILACS | ID: biblio-1020958

RESUMO

ABSTRACT BACKGROUND: There is evidence that genetic predisposition and epigenetic alteration (e.g. DNA methylation) play major roles in lung cancer. In our genetic epidemiological studies, rs1970764 in oncogene PPP1R13L was most consistently associated with lung cancer risk. Here, we explored the role of PPP1R13L methylation in lung cancer development. DESIGN AND SETTING: Analytical cross-sectional study (45 lung cancer cases and 45 controls), conducted in China. METHODS: We investigated the DNA methylation status of 2,160 cytosine-phosphate-guanine (CpG) sites in the PPP1R13L promoter region using the EpiTYPER assay of the Sequenom MassARRAY platform. RESULTS: In the whole study group, the methylation levels of CpG-6, CpG-9, CpG-20 and CpG-21 were significantly lower and those of CpG-16 were significantly higher in cases than in controls. Among smokers, the methylation levels at five CpG sites (CpG-6, CpG-11, CpG-15, CpG-20 and CpG-21) were statistically significantly lower among cases. Among men, the methylation levels at four CpG sites (CpG-11, CpG-15, CpG-20 and CpG-21) were significantly lower among cases. Regarding smokers, the methylation levels at CpG-7.8 and CpG-21 among cases and at CpG-22 among controls were significantly lower, compared with nonsmokers. The frequency of positivity for methylation was not significantly different between lung cancer cases and controls (68.22% for cases and 71.87% for controls; P = 0.119). CONCLUSION: Our study on a Chinese population suggests that lung cancer patients have aberrant methylation status (hypomethylation tended to be more frequent) in peripheral blood leukocytes at several CpG sites in the PPP1R13L promoter region and that exposure to smoking may influence methylation status.


Assuntos
Humanos , Masculino , Feminino , Pessoa de Meia-Idade , Idoso , Proteínas Repressoras/genética , Metilação de DNA/genética , Predisposição Genética para Doença/genética , Peptídeos e Proteínas de Sinalização Intracelular/genética , Neoplasias Pulmonares/genética , Estudos de Casos e Controles , Estudos Transversais , Regiões Promotoras Genéticas
7.
Braz. j. med. biol. res ; 52(8): e8341, 2019. tab, graf
Artigo em Inglês | LILACS | ID: biblio-1011606

RESUMO

MicroRNAs (miRNAs), as post-transcriptional regulators, have been reported to be involved in the initiation and progression of various types of cancer, including gastric cancer (GC). The present study aimed to investigate the role of miR-383-5p in gastric carcinogenesis. Cell viability was analyzed using CCK-8 kit. Annexin V-fluorescein isothiocyanate/propidium iodide double staining was used to evaluate cell apoptosis. The expression levels of miR-383-5p and histone deacetylase 9 (HDAC9) mRNA in GC tissues and cell lines were analyzed using RT-qPCR. The protein expression of HDAC9 was detected by western blotting. We found that HDAC9 was up-regulated and miR-383-5p was down-regulated in GC tissues and cell lines. High HDAC9 expression or low miR-383-5p expression was closely related to poor prognosis and metastasis in GC patients. HDAC9 knockout or miR-383-5p mimics led to growth inhibition and increased apoptosis in AGS and SGC-7901 cells. More importantly, we validated that miR-383-5p as a post-transcriptional regulator inhibited HDAC9 expression and was inversely correlated with HDAC9 expression in GC tissues. miR-383-5p had the opposite effects to HDAC9 in gastric carcinogenesis. miR-383-5p played an important role in gastric carcinogenesis, and it is one of the important mechanisms to regulate oncogenic HDAC9 in GC, which might be helpful in the development of novel therapeutic strategies for the treatment of GC.


Assuntos
Humanos , Masculino , Feminino , Pessoa de Meia-Idade , Proteínas Repressoras/metabolismo , Neoplasias Gástricas/patologia , Carcinoma/patologia , MicroRNAs/metabolismo , Histona Desacetilases/metabolismo , Neoplasias Gástricas/genética , Neoplasias Gástricas/metabolismo , RNA Mensageiro/metabolismo , Carcinoma/genética , Carcinoma/metabolismo , Regulação para Baixo , Regulação Neoplásica da Expressão Gênica , Apoptose , Progressão da Doença , Proliferação de Células/genética , Carcinogênese/genética , Estadiamento de Neoplasias
8.
Braz. j. microbiol ; 49(1): 200-206, Jan.-Mar. 2018. tab, graf
Artigo em Inglês | LILACS | ID: biblio-889189

RESUMO

ABSTRACT Bacteroides fragilis is the strict anaerobic bacteria most commonly found in human infections, and has a high mortality rate. Among other virulence factors, the remarkable ability to acquire resistance to a variety of antimicrobial agents and to tolerate nanomolar concentrations of oxygen explains in part their success in causing infection and colonizing the mucosa. Much attention has been given to genes related to multiple drug resistance derived from plasmids, integrons or transposon, but such genes are also detected in chromosomal systems, like the mar (multiple antibiotic resistance) locus, that confer resistance to a range of drugs. Regulators like MarR, that control expression of the locus mar, also regulate resistance to organic solvents, disinfectants and oxygen reactive species are important players in these events. Strains derived from the parental strain 638R, with mutations in the genes hereby known as marRI (BF638R_3159) and marRII (BF638R_3706) were constructed by gene disruption using a suicide plasmid. Phenotypic response of the mutant strains to hydrogen peroxide, cell survival assay against exposure to oxygen, biofilm formation, resistance to bile salts and resistance to antibiotics was evaluated. The results showed that the mutant strains exhibit statistically significant differences in their response to oxygen stress, but no changes were observed in survival when exposed to bile salts. Biofilm formation was not affected by either gene disruption. Both mutant strains however, became more sensitive to multiple antimicrobial drugs tested. This indicates that as observed in other bacterial species, MarR are an important resistance mechanism in B. fragilis.


Assuntos
Humanos , Antibacterianos/farmacologia , Proteínas de Bactérias/genética , Bacteroides fragilis/efeitos dos fármacos , Bacteroides fragilis/genética , Infecções por Bacteroides/microbiologia , Proteínas Repressoras/genética , Proteínas de Bactérias/metabolismo , Bacteroides fragilis/isolamento & purificação , Bacteroides fragilis/metabolismo , Regulação Bacteriana da Expressão Gênica/efeitos dos fármacos , Inativação Gênica , Testes de Sensibilidade Microbiana , Proteínas Repressoras/metabolismo
9.
Arch. endocrinol. metab. (Online) ; 62(2): 205-211, Mar.-Apr. 2018. tab, graf
Artigo em Inglês | LILACS | ID: biblio-887654

RESUMO

ABSTRACT Objective The transcriptional repressor DREAM is involved in thyroid-specific gene expression, thyroid enlargement and nodular development, but its clinical utility is still uncertain. In this study we aimed to investigate whether DREAM mRNA levels differ in different thyroid tumors and how this possible difference would allow the use of DREAM gene expression as molecular marker for diagnostic and/or prognosis purpose. Materials and methods We quantified DREAM gene mRNA levels and investigated its mutational status, relating its expression and genetic changes to diagnostic and prognostic features of 200 thyroid tumors, being 101 malignant [99 papillary thyroid carcinomas (PTC) and 2 anaplastic thyroid carcinomas] and 99 benign thyroid lesions [49 goiter and 50 follicular adenomas (FA)]. Results Levels of mRNA of DREAM gene were higher in benign (0.7909 ± 0.6274 AU) than in malignant (0.3373 ± 0.6274 AU) thyroid lesions (p < 0.0001). DREAM gene expression was able to identify malignancy with 66.7% sensitivity, 85.4% specificity, 84.2% positive predictive value (PPV), 68.7% negative predictive value (NPV), and 75.3% accuracy. DREAM mRNA levels were also useful distinguishing the follicular lesions FA and FVPTC with 70.2% sensitivity, 73.5% specificity, 78.5% PPV, 64.1% NPV, and 71.6% accuracy. However, DREAM gene expression was neither associated with clinical features of tumor aggressiveness, nor with recurrence or survival. Six different genetic changes in non-coding regions of DREAM gene were also found, not related to DREAM gene expression or tumor features. Conclusion We suggest that DREAM gene expression may help diagnose thyroid nodules, identifying malignancy and characterizing follicular-patterned thyroid lesions; however, it is not useful as a prognostic marker.


Assuntos
Humanos , Masculino , Feminino , Pessoa de Meia-Idade , Proteínas Repressoras/genética , RNA Mensageiro/genética , Neoplasias da Glândula Tireoide/diagnóstico , Biomarcadores Tumorais/genética , Proteínas Interatuantes com Canais de Kv/genética , Elementos Reguladores de Transcrição/genética , Prognóstico , Proteínas Repressoras/metabolismo , RNA Mensageiro/metabolismo , Neoplasias da Glândula Tireoide/genética , Neoplasias da Glândula Tireoide/metabolismo , Biomarcadores Tumorais/metabolismo , Sensibilidade e Especificidade , Proteínas Interatuantes com Canais de Kv/metabolismo , Reação em Cadeia da Polimerase em Tempo Real , Estadiamento de Neoplasias
10.
Braz. j. med. biol. res ; 49(12): e5805, 2016. graf
Artigo em Inglês | LILACS | ID: biblio-828178

RESUMO

Machado-Joseph disease (MJD) or spinocerebellar ataxia type 3 (SCA3) is an autosomal dominant neurodegenerative disorder caused by expansion of the polyglutamine domain of the ataxin-3 (ATX3) protein. MJD/SCA3 is the most frequent autosomal dominant ataxia in many countries. The mechanism underlying MJD/SCA3 is thought to be mainly related to protein misfolding and aggregation leading to neuronal dysfunction followed by cell death. Currently, there are no effective treatments for patients with MJD/SCA3. Here, we report on the potential use of lithium carbonate and coenzyme Q10 to reduce cell death caused by the expanded ATX3 in cell culture. Cell viability and apoptosis were evaluated by MTT assay and by flow cytometry after staining with annexin V-FITC/propidium iodide. Treatment with lithium carbonate and coenzyme Q10 led to a significant increase in viability of cells expressing expanded ATX3 (Q84). In addition, we found that the increase in cell viability resulted from a significant reduction in the proportion of apoptotic cells. Furthermore, there was a significant change in the expanded ATX3 monomer/aggregate ratio after lithium carbonate and coenzyme Q10 treatment, with an increase in the monomer fraction and decrease in aggregates. The safety and tolerance of both drugs are well established; thus, our results indicate that lithium carbonate and coenzyme Q10 are good candidates for further in vivo therapeutic trials.


Assuntos
Humanos , Ataxina-3/efeitos dos fármacos , Morte Celular/efeitos dos fármacos , Carbonato de Lítio/farmacologia , Doença de Machado-Joseph , Proteínas Repressoras/efeitos dos fármacos , Ubiquinona/análogos & derivados , Diferenciação Celular/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Doença de Machado-Joseph/tratamento farmacológico , Ubiquinona/farmacologia
11.
Biomédica (Bogotá) ; 35(3): 437-443, jul.-sep. 2015. tab
Artigo em Inglês | LILACS | ID: lil-765472

RESUMO

Introduction: Fetal hemoglobin is an important factor in modulating the severity of sickle cell anemia. Its level in peripheral blood underlies strong genetic determination. Associated loci with increased levels of fetal hemoglobin display population-specific allele frequencies. Objective: We investigated the presence and effect of known common genetic variants promoting fetal hemoglobin persistence (rs11886868, rs9399137, rs4895441, and rs7482144) in 60 Colombian patients with sickle cell anemia. Materials and methods: Four single nucleotide polymorphisms (SNP) were genotyped by restriction fragment length polymorphisms (RFLP) and the use of the TaqMan procedure. Fetal hemoglobin (HbF) from these patients was quantified using the oxyhemoglobin alkaline denaturation technique. Genotype frequencies were compared with frequencies reported in global reference populations. Results: We detected genetic variants in the four SNPs, reported to be associated with higher HbF levels for all four SNPs in the Colombian patients. Genetic association between SNPs and HbF levels did not reach statistical significance. The frequency of these variants reflected the specific ethnic make-up of our patient population: A high prevalence of rs7482144-'A' reflects the West-African origin of the sickle cell mutation, while high frequencies of rs4895441-'G' and rs11886868-'C' point to a significant influence of an Amerindian ethnic background in the Colombian sickle cell disease population. Conclusion: These results showed that in the sickle cell disease population in Colombia there is not a unique genetic background, but two (African and Amerindian). This unique genetic situation will provide opportunities for a further study of these loci, such as fine-mapping and molecular-biological investigation. Colombian patients are expected to yield a distinctive insight into the effect of modifier loci in sickle cell disease.


Introducción. La hemoglobina fetal es un importante factor modulador de la gravedad de la anemia falciforme, cuya expresión está muy condicionada por el factor genético. Los loci asociados con el incremento de la hemoglobina fetal pueden presentar frecuencias alélicas específicas para cada población. Objetivo. Investigar la presencia y el efecto de las variantes genéticas rs11886868, rs9399137, rs4895441 y rs7482144 asociadas con la persistencia de hemoglobina fetal, en 60 pacientes colombianos con anemia falciforme. Materiales y métodos. Se hizo la genotipificación de los polimorfismos de nucleótido simple ( Single Nucleotide Polymorphisms, SNP) mediante la técnica de polimorfismos de longitud de fragmentos de restricción ( Restriction Fragment Length Polymorphisms, RFLP) y el procedimiento TaqMan. La hemoglobina fetal (HbF) se cuantificó utilizando la técnica de desnaturalización alcalina de la oxihemoglobina. Las frecuencias genotípicas se compararon con las reportadas en poblaciones de referencia global. Resultados. Se observaron variantes genéticas ya reportadas para aumento de HbF en los cuatro SNP. La asociación genética entre los SNP y el incremento de la HbF no alcanzó significancia estadística. La frecuencia de estos alelos reflejó la siguiente composición específica en esta muestra de pacientes colombianos: una gran prevalencia de rs7482144-'A', lo que indica que el origen de la mutación para la anemia falciforme es África occidental, y una gran frecuencia de rs4895441-'G' y rs11886868-'C', lo que denota la influencia significativa del origen genético amerindio. Conclusión. Los resultados evidenciaron que la población con anemia falciforme de Colombia no tiene un único origen genético, sino que existen dos (africano y amerindio). Esta situación genética única ofrece la oportunidad de llevar a cabo un estudio más amplio de estos loci a nivel molecular. Se espera que el estudio de pacientes colombianos permita una visión diferente del efecto de los loci modificadores en esta enfermedad.


Assuntos
Adolescente , Adulto , Criança , Pré-Escolar , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Adulto Jovem , Hemoglobina Fetal/genética , Proteínas Nucleares/genética , Etnicidade/genética , Proteínas de Transporte/genética , Polimorfismo de Nucleotídeo Único , Locos de Características Quantitativas/genética , gama-Globinas/genética , Anemia Falciforme/genética , Proteínas Repressoras , Senegal/etnologia , Serra Leoa/etnologia , Polimorfismo de Fragmento de Restrição , Indígenas Sul-Americanos/genética , Colômbia/epidemiologia , Negro ou Afro-Americano/genética , Genótipo , Anemia Falciforme/sangue , Anemia Falciforme/etnologia
12.
Radiol. bras ; 48(2): 93-100, Mar-Apr/2015. graf
Artigo em Inglês | LILACS | ID: lil-746612

RESUMO

Objective: To present a detailed explanation on the processing of magnetic susceptibility weighted imaging (SWI), demonstrating the effects of echo time and sensitive mask on the differentiation between calcification and hemosiderin. Materials and Methods: Computed tomography and magnetic resonance (magnitude and phase) images of six patients (age range 41– 54 years; four men) were retrospectively selected. The SWI images processing was performed using the Matlab’s own routine. Results: Four out of the six patients showed calcifications at computed tomography images and their SWI images demonstrated hyperintense signal at the calcification regions. The other patients did not show any calcifications at computed tomography, and SWI revealed the presence of hemosiderin deposits with hypointense signal. Conclusion: The selection of echo time and of the mask may change all the information on SWI images, and compromise the diagnostic reliability. Amongst the possible masks, the authors highlight that the sigmoid mask allows for contrasting calcifications and hemosiderin on a single SWI image. .


Objetivo: Expor em detalhes o processamento da imagem ponderada em suscetibilidade magnética (susceptibility weighted imaging – SWI), destacando o efeito da escolha do tempo de eco e da máscara sensível à diferenciação de calcificação e hemossiderina simultaneamente. Materiais e Métodos: Imagens de tomografia computadorizada e por ressonância magnética (magnitude e fase) foram selecionadas, retrospectivamente, de seis pacientes (idades entre 41 e 54 anos; quatro homens). O processamento das imagens SWI foi realizado em rotina própria no programa Matlab. Resultados: Dos seis pacientes estudados, quatro apresentaram calcificações nas imagens de tomografia computadorizada. Nestes, as imagens SWI mostraram sinal hiperintenso para as regiões de calcificações. Os outros dois pacientes não apresentaram calcificações nas imagens de tomografia computadorizada e apresentaram depósito de hemossiderina com sinal hipointenso na imagem SWI. Conclusão: A escolha do tempo de eco e da máscara pode alterar toda a informação da imagem SWI e comprometer a confiabilidade diagnóstica. Dentre as possíveis máscaras, destacamos que a máscara sigmoide permite contrastar calcificação e hemossiderina em uma única imagem SWI. .


Assuntos
Animais , Camundongos , Processamento Alternativo/genética , Proteínas de Transporte/genética , Proteínas de Transporte/metabolismo , Proteínas Nucleares/genética , Proteínas Nucleares/metabolismo , Proteína de Ligação a Regiões Ricas em Polipirimidinas/genética , Tropomiosina/genética , Sequência de Bases , Sítios de Ligação , Primers do DNA , Éxons , Vetores Genéticos , Ligantes , Fases de Leitura Aberta , Reação em Cadeia da Polimerase , Proteína de Ligação a Regiões Ricas em Polipirimidinas/metabolismo , Proteínas Recombinantes/metabolismo , Proteínas Repressoras/metabolismo , Transfecção
13.
Cad. saúde pública ; 31(4): 722-732, 04/2015.
Artigo em Inglês | LILACS | ID: lil-744848

RESUMO

We aimed to verify doctor's perception of the qualitative research method, via a qualitative study of interviews with questions on the academic profile of doctors and on the methodology. We interviewed 42 professionals, of which 18 had experience with the qualitative method and 24 with the quantitative method. The results showed that knowledge on the qualitative method was virtually nil among "quantitative researchers", who did not value qualitative research, although some of those realized that it would be important to be more accepting in clinical practice. Others only considered the method as subsidiary to quantitative. The majority considered qualitative methods as lacking academic structure, taking too long to conduct empirical studies, and being difficult to publish. All of them criticized the misuse of the method, and the "quantitatives" pointed out the problem of being unable to reproduce. We concluded that widening the use of the qualitative method by doctors requires investment from the beginning of the academic career and participation in qualitative research projects.


El objetivo es verificar la percepción de médicos sobre el método de investigación cualitativa. Se trata de un estudio cualitativo por medio de entrevistas con preguntas sobre el perfil de los médicos y sobre el método. Entrevistamos a 42 profesionales, 18 con experiencia en el método cualitativo y 24 con el cuantitativo. Los resultados mostraron que el conocimiento sobre lo cualitativo es casi nulo entre los "cuantitativistas", que no valoran la investigación cualitativa, aunque algunos se dan cuenta de que sería importante tener un enfoque más amplio en la práctica clínica. Otros la ven como subsidiaria a lo cuantitativo. Sus dificultades para utilizar ese abordaje son: falta de formación, cantidad de tiempo que exigen y problemas de publicación. Todos han criticado el mal uso del método. Los "cuantitativistas" han destacado como fragilidad, la no reproductibilidad. Llegamos a la conclusión de que para ampliar el uso de los abordajes cualitativos entre los médicos es importante invertir en su formación desde el inicio del curso y la participación en proyectos de investigación cualitativa.


Objetivamos verificar a percepção de médicos sobre o método qualitativo de pesquisa. Estudo qualitativo por meio de entrevistas com questões sobre o perfil acadêmico do médico e perguntas abertas a respeito do método. Entrevistamos 42 profissionais, sendo 18 com experiência no método qualitativo e 24 com o quantitativo. Os resultados evidenciaram que o conhecimento sobre o qualitativo é quase nulo entre os pesquisadores "quantitativistas", os quais não valorizam a pesquisa qualitativa, embora alguns percebam que seria importante ter uma postura mais compreensiva na prática clínica. Outros só a veem como subsidiária ao quantitativo. As principais dificuldades da maioria são: falta de formação, tempo longo despendido nos estudos empíricos e dificuldade de publicação. Todos os entrevistados criticaram o mau uso do método, e os "quantitativistas" ressaltaram, como problema, sua não reprodutibilidade. Concluímos que ampliar o uso do método qualitativo por médicos exige investimento na formação desde o início da graduação e participação em projetos de pesquisa qualitativa.


Assuntos
Animais , Humanos , Camundongos , Anilidas/farmacologia , Benzodiazepinonas/farmacologia , /farmacologia , Inibidores de Proteínas Quinases/farmacologia , Proteínas Serina-Treonina Quinases/antagonistas & inibidores , Pirimidinas/farmacologia , Proteínas Repressoras/antagonistas & inibidores , Células Cultivadas , Movimento Celular/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Avaliação Pré-Clínica de Medicamentos , Ativação Enzimática/efeitos dos fármacos , Neoplasias/patologia , Proteínas Quinases/genética , Proteínas Serina-Treonina Quinases/genética , Proteínas Serina-Treonina Quinases/metabolismo , Proteínas Serina-Treonina Quinases/fisiologia , Proteínas Repressoras/agonistas , Proteínas Repressoras/genética , Especificidade por Substrato , Proteínas Supressoras de Tumor/fisiologia
14.
Braz. J. Psychiatry (São Paulo, 1999, Impr.) ; 37(1): 49-54, Jan-Mar/2015. tab, graf
Artigo em Inglês | LILACS | ID: lil-741937

RESUMO

Objective: Peritraumatic reactions feature prominently among the main predictors for development of posttraumatic stress disorder (PTSD). Peritraumatic tonic immobility (PTI), a less investigated but equally important type of peritraumatic response, has been recently attracting the attention of researchers and clinicians for its close association with traumatic reactions and PTSD. Our objective was to investigate the role of PTI, peritraumatic panic, and dissociation as predictors of PTSD symptoms in a cohort of police recruits (n=132). Methods: Participants were asked to complete the following questionnaires during academy training and after the first year of work: Posttraumatic Stress Disorder Checklist - Civilian Version (PCL-C), Physical Reactions Subscale (PRS), Peritraumatic Dissociative Experiences Questionnaire (PDEQ), Tonic Immobility Scale (TIS), and Critical Incident History Questionnaire. Results: Employing a zero-inflated negative binomial regression model, we found that each additional point in the TIS was associated with a 9% increment in PCL-C mean scores (RM = 1.09), whereas for PRS, the increment was 7% (RM = 1.07). As the severity of peritraumatic dissociation increased one point in the PDEQ, the chance of having at least one symptom in the PCL-C increased 22% (OR = 1.22). Conclusions: Our findings highlight the need to expand investigation on the incidence and impact of PTI on the mental health of police officers. .


Assuntos
Animais , Humanos , Camundongos , Proteínas Cromossômicas não Histona/fisiologia , Leucemia/patologia , Proteína de Leucina Linfoide-Mieloide/genética , Células-Tronco Neoplásicas/patologia , Oncogenes , Proteínas Repressoras/fisiologia , Apoptose , Proteínas Cromossômicas não Histona/genética , Citometria de Fluxo , Leucemia/genética , Leucemia/metabolismo , Reação em Cadeia da Polimerase , Proteínas Repressoras/genética
15.
Arq. neuropsiquiatr ; 73(1): 12-17, 01/2015. tab, graf
Artigo em Inglês | LILACS | ID: lil-732211

RESUMO

Objective To present a seven-cases serie of Mowat-Wilson syndrome (MWS). Method All patients with positive mutation for the ZEB2 were evaluated by a geneticist and a neurologist, with clinical and laboratorial characterization. Results A peculiar facies and mental retardation were present in all patients. The Denver II scale showed intense delay in all aspects, especially fine motor and adaptive. Acquired microcephaly was observed in five patients. Only one patient did not present epilepsy. Epilepsy was focal and predominating in sleep, with status epilepticus in three patients. The initial seizure was associated with fever in most patients (4/6). The EEG showed epileptic focal activity (5/7). The imaging studies revealed total agenesis (4/7) and partial agenesis of the corpus callosum (1/7). Conclusion Physicians who care for patients with mental retardation and epilepsy should be aware of SMW. .


Objetivo Apresentar uma série de sete casos da síndrome de Mowat-Wilson (SMW). Método Todos os pacientes com estudo positivo para a mutação ZEB2 foram avaliados por um geneticista e um neurologista, com a caracterização clínica e laboratorial. Resultados Todos apresentavam fácies peculiar e retardo mental. A escala de Denver II evidenciou intenso atraso em todos os aspectos, sobretudo motor fino e adaptativo. Microcefalia adquirida foi observada em cinco pacientes. Apenas um paciente não apresentava epilepsia, sendo esta focal e predominando no sono, sendo relatado estado de mal em três pacientes. A crise inicial estava associada à febre na maioria dos pacientes (4/6). O EEG evidenciou atividade epiléptica focal na maioria (5/7). Ao estudo de imagem foi observada agenesia total (4/7) e parcial do corpo caloso (1/7). Conclusão Médicos que lidam com pacientes com retardo mental e epilepsia devem saber distinguir as características peculiares da SMW. .


Assuntos
Criança , Pré-Escolar , Feminino , Humanos , Lactente , Masculino , Doença de Hirschsprung/genética , Proteínas de Homeodomínio/genética , Deficiência Intelectual/genética , Mutação , Microcefalia/genética , Proteínas Repressoras/genética , Fácies , Doença de Hirschsprung/fisiopatologia , Deficiência Intelectual/fisiopatologia , Microcefalia/fisiopatologia , Estudos Retrospectivos
16.
Biol. Res ; 48: 1-8, 2015. graf
Artigo em Inglês | LILACS | ID: biblio-950791

RESUMO

BACKGROUND: The CCCTC-binding factor (CTCF) is a highly conserved insulator protein that plays various roles in many cellular processes. CTCF is one of the main architecture proteins in higher eukaryotes, and in combination with other architecture proteins and regulators, also shapes the three-dimensional organization of a genome. Experiments show CTCF partially remains associated with chromatin during mitosis. However, the role of CTCF in the maintenance and propagation of genome architectures throughout the cell cycle remains elusive. RESULTS: We performed a comprehensive bioinformatics analysis on public datasets of Drosophila CTCF (dCTCF). We characterized dCTCF-binding sites according to their occupancy status during the cell cycle, and identified three classes: interphase-mitosis-common (IM), interphase-only (IO) and mitosis-only (MO) sites. Integrated function analysis showed dCTCF-binding sites of different classes might be involved in different biological processes, and IM sites were more conserved and more intensely bound. dCTCF-binding sites of the same class preferentially localized closer to each other, and were highly enriched at chromatin syntenic and topologically associating domains boundaries. CONCLUSIONS: Our results revealed different functions of dCTCF during the cell cycle and suggested that dCTCF might contribute to the establishment of the three-dimensional architecture of the Drosophila genome by maintaining local chromatin compartments throughout the whole cell cycle.


Assuntos
Animais , Proteínas Repressoras/fisiologia , Cromatina/fisiologia , Proteínas de Drosophila/fisiologia , Drosophila melanogaster/química , Genoma de Inseto/genética , Mitose/fisiologia , Sítios de Ligação , Sequência de Bases , Ciclo Celular/fisiologia , Sequência Conservada , Biologia Computacional , Sintenia , Montagem e Desmontagem da Cromatina/fisiologia , Anotação de Sequência Molecular , Conjuntos de Dados como Assunto , Fator de Ligação a CCCTC , Interfase/fisiologia
17.
Hist. ciênc. saúde-Manguinhos ; 21(4): 1151-1177, Oct-Dec/2014.
Artigo em Português | LILACS | ID: lil-732520

RESUMO

Investiga o estatuto e as condições de emergência da categoria nosológica de síndrome do coração irritável presente nos discursos médicos anglo-americanos na segunda metade do século XIX. No contexto da Guerra Civil Americana, examina elementos sócio-históricos que configuraram a atenção médica sobre os sintomas de ordem cardíaca de soldados. Destacam-se os valores morais de médicos-militares frente aos sintomas de medo em combatentes, assim como as hipóteses etiológicas britânicas e norte-americanas que consolidaram o estatuto nosológico do sofrimento dos soldados com palpitações. Propõe análise da especificidade da síndrome do coração irritável frente às categorias nosológicas do medo descritas pela nosologia psiquiátrica atual.


This paper examines the characteristics and the conditions for the emergence of the nosological category known as irritable heart syndrome to be found in Anglo-American medical literature in the second half of the nineteenth century. In the context of the American Civil War, it looks at some of the socio-historical elements, which comprised the medical care given to certain cardiac symptoms shown by soldiers. It emphasizes the moral values influencing the medical attitudes of military physicians towards symptoms of fear experienced by combatants, as well as the British and American etiological theories, which contributed to the nosological characterization of the suffering of soldiers afflicted with palpitations. Finally, it offers a brief analysis of the specific nature of the medical category known as irritable heart syndrome in the light of the categories of fear described by current psychiatric nosology.


Assuntos
Acetilcoenzima A/fisiologia , Aspergillus nidulans/metabolismo , Proteínas Fúngicas/fisiologia , Fenilacetatos/metabolismo , Proteínas Repressoras/fisiologia , Ácido Acético/farmacologia , Transporte Biológico
18.
Rev. bras. enferm ; 67(5): 722-729, Sep-Oct/2014. tab
Artigo em Português | LILACS, BDENF - Enfermagem | ID: lil-731212

RESUMO

Objetivou-se estimar o tempo de decisão para procura de atendimento (TD) para homens e mulheres com infarto agudo do miocárdio (IAM); analisar a influência de variáveis ambientais no TD e a interação entre gênero e variáveis ambientais para o desfecho TD. Estudo transversal, envolvendo cem pacientes, entrevistados em hospitais de Salvador. Na análise dos dados empregou-se o Qui-quadrado ou Exato de Fisher e o Modelo de Regressão Linear Robusto. Predominou o IAM ocorrido no domicílio, familiares no entorno, e os pacientes sendo alvo de ações equivocadas. Observou-se TD elevado para mulheres (0,9h) e homens (1,4h). Aqueles em casa no início dos sintomas tiveram maior TD, comparados aos no trabalho e menor em relação aos em via pública (p=0,047). Houve interação estatisticamente significante entre gênero e viver acompanhado; e entre gênero e ter companheiro e filhos no entorno, para o desfecho TD. O cuidar em enfermagem focalizado nas especificidades de fatores ambientais e de gênero pode otimizar o atendimento precoce.


The purpose was to estimate the decision time (DT) for searching for attendance for men and women suffering from acute myocardial infarction (AMI); and to analyze the influence of surrounding variables in the DT. Transversal study, involving one hundred patients interviewed in hospitals of Salvador-BA, Brazil. For data analysis, it was used the chi-squared or Fisher’s exact test, and the Robust Linear Regression Model. AMI at the home predominated, with family members and patients receiving mistaken actions. A high DT was observed both, for women (0.9h) and men (1.4h). Those at home during the initial symptoms had higher DT, compared to those at work; and lower in relation to those in public spaces (p=0.047). Statistically significant interaction occurred among gender and the fact of living with company; and among gender and having a companion and children, for the outcome of the DT. Nursing care focused on the specificity of surrounding factors and gender can optimize early attendance.


Se objetivó estimar el tiempo de decisión para buscar atendimiento (TD) para hombres y mujeres con infarto agudo de miocardio (IAM); analizar la influencia de variables ambientales en TD y la interacción entre genero y variables ambientales para el desfecho del TD. Estudio transversal, envolviendo cien pacientes entrevistados en hospitales de Salvador-BA, Brasil. En el análisis se utilizó el chi-cuadrado o el Teste Exacto de Fisher y el Modelo de Regresión Linear Robusto. Predominó el IAM en el domicilio, familiares en el entorno y con pacientes siendo objeto de acciones equivocadas. Se observó TD elevados para mujeres (0,9h) y hombres (1,4h). Aquellos en sus casas en el inicio de los síntomas tuvieron mayor TD, comparados a los en el trabajo, y menor en relación aquellos en vía pública (p=0,047). Hubo interacción estadísticamente significante entre genero y vivir acompañado y entre genero y tener compañero e hijos en el entorno, para el desfecho del TD. El cuidar en enfermería focalizado en especificidades de factores ambientales y de géneros puede optimizar el atendimiento precoce.


Assuntos
Animais , Masculino , Ratos , Hormônio do Crescimento/farmacologia , /farmacologia , Lipopolissacarídeos/toxicidade , Proteínas Repressoras , Fatores de Transcrição , Fator de Necrose Tumoral alfa/farmacologia , Resistência a Medicamentos , Fator de Crescimento Insulin-Like I/genética , Proteínas/genética , Ratos Sprague-Dawley , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Receptores da Somatotropina/genética , Proteínas Supressoras da Sinalização de Citocina
19.
Rev. Esc. Enferm. USP ; 48(spe): 16-22, 08/2014. tab
Artigo em Inglês | LILACS, BDENF - Enfermagem | ID: lil-731304

RESUMO

Objective To analyze the determinants of emergency contraception non-use among women in unplanned and ambivalent pregnancies. Method Cross-sectional study with a probabilistic sample of 366 pregnant women from 12 primary health care units in the city of São Paulo, Brazil. A multinomial logistic regression was performed, comparing three groups: women who used emergency contraception to prevent ongoing pregnancies (reference); women who made no use of emergency contraception, but used other contraceptive methods; and women who made no use of any contraceptive methods at all. Results Cohabitation with a partner was the common determinant of emergency contraception non-use. No pregnancy risk awareness, ambivalent pregnancies and no previous use of emergency contraception also contributed to emergency contraception non-use. Conclusion Apart from what is pointed out in the literature, knowledge of emergency contraception and the fertile period were not associated to its use. .


Objetivo Analizar los determinantes del no uso de la anticoncepción de emergencia entre las mujeres con embarazo no planeado o ambivalente. Método Estudio transversal en una muestra probabilística de 366 mujeres embarazadas de 12 Unidades Básicas de Salud de São Paulo. Mediante regresión logística multinomial, se comparó tres grupos de mujeres: aquellas que usaron la anticoncepción de emergencia para prevenir el embarazo en curso (referencia), aquellas que usaron algún método anticonceptivo, pero no la anticoncepción de emergência; y aquellas que no usaron ningún método. Resultados Los hallazgos mostraron que vivir com la pareja fue el determinante común del no uso de la anticoncepción de emergencia. No tener conciencia del riesgo de embarazo, estar en un embarazo ambivalente y nunca tener utilizado la anticoncepción de emergencia también fueron associados con su no uso para prevenir el embarazo en curso. Conclusión Contrariamente a lo que reporta la literatura, el conocimiento de la anticoncepción de emergencia y el período fértil no mostró asociación con el no uso. .


Objetivo Analisar os determinantes do não uso da anticoncepção de emergência entre mulheres com gravidez não planejada ou ambivalente. Método Estudo transversal com amostra probabilística de 366 gestantes de 12 Unidades Básicas de Saúde da cidade de São Paulo. Por meio de regressão logística multinomial, compararam-se três grupos de mulheres: as que usaram anticoncepção de emergência para prevenir a gravidez em curso (referência); as que usaram algum método contraceptivo, mas não anticoncepção de emergência; e as que não usaram nenhum método. Resultados Os achados mostraram que morar com o parceiro foi o determinante comum do não uso da anticoncepção de emergência. Não ter consciência do risco de engravidar, estar em uma gravidez ambivalente e nunca ter usado anticoncepção de emergência também foram associados ao seu não uso para prevenir a gravidez em curso. Conclusão Diferentemente do que relata a literatura, o conhecimento sobre anticoncepção de emergência e sobre o período fértil não mostrou qualquer associação ao não uso. .


Assuntos
Proteínas de Ligação a DNA , Escherichia coli/genética , Mapeamento de Interação de Proteínas/métodos , Técnicas do Sistema de Duplo-Híbrido , Bacteriófago lambda/genética , DNA Bacteriano/genética , RNA Polimerases Dirigidas por DNA/biossíntese , RNA Polimerases Dirigidas por DNA/genética , RNA Polimerases Dirigidas por DNA/fisiologia , Proteínas de Escherichia coli/biossíntese , Proteínas de Escherichia coli/genética , Proteínas de Escherichia coli/fisiologia , Escherichia coli/enzimologia , Genes Reporter/genética , Fosforilação , Plasmídeos/biossíntese , Plasmídeos/genética , Regiões Promotoras Genéticas/genética , RNA Bacteriano/genética , Proteínas Recombinantes de Fusão/biossíntese , Proteínas Recombinantes de Fusão/genética , Proteínas Recombinantes de Fusão/fisiologia , Proteínas Repressoras/biossíntese , Proteínas Repressoras/genética , Proteínas Repressoras/fisiologia , Transcrição Gênica/genética , Transcrição Gênica/fisiologia , Proteínas Virais/biossíntese , Proteínas Virais/genética , Proteínas Virais/fisiologia , Proteínas Virais Reguladoras e Acessórias , beta-Galactosidase/biossíntese , beta-Lactamases/biossíntese
20.
Rio de Janeiro; s.n; 2014. 135 p
Tese em Português | Inca, LILACS | ID: biblio-1117754

RESUMO

A LMA é uma neoplasia hematológica caracterizada pela proliferação anormal de precursores mielóides na medula óssea decorrente de uma parada no processo de diferenciação destas células. A etiologia da leucemia ainda é desconhecida, mas alguns fatores, incluindo a presença de translocações cromossômicas podem contribuir para o aparecimento desta neoplasia.Três subgrupos de alterações genéticas vêm sendo definidos nos últimos anos como os de maior freqüência em LMA primária da criança. O grupo que envolve rearranjos do gene CBF (core binding factor): t(8;21)(q22;q22) e inv(16)(p13;q22); as leucemias associadas a alterações no gene MLL (anormalidades da região 11q23); e as leucemias associadas ao rearranjo PML-RAR: t(15;17)(q22;q12). Apesar de todo o conhecimento já acumulado sobre as bases moleculares dos processos leucemogênicos da LMA, alterações em reguladores epigenéticos vem ganhando destaque na patologia da leucemia. Neste contexto, os genes pertencentes ao complexo Gênico Polycomb (PcG) estão associados ao silenciamento epigenético durante o desenvolvimento embrionário e durante a carcinogênese de diversos tumores, incluindo a leucemia mielóide aguda (LMA). Portanto, o objetivo deste estudo foi realizar uma análise citogenética e de expressão dos genes do complexo PcG em crianças diagnosticadas com LMA para contribuir para o entendimento da biologia desta neoplasia tão heterogênea. As amostras de medula óssea de 84 pacientes foram tratadas de acordo com os protocolos padrões e, as técnicas de citogenética, envolvendo técnicas moleculares foram realizadas, sendo possível evidenciar uma alta taxa de anormalidades cromossômicas de 89%. Além disso, uma alta taxa da t(15;17)(q22;q12) pode ser observada, assim como, várias alterações não-recorrentes puderam ser identificadas, já que várias técnicas de citogenética molecular de alta resolução foram utilizadas. Dos 84 pacientes, 52 pacientes foram avaliados quanto ao perfil de expressão de alguns dos genes PcG, utilizando a metodologia de PCR em tempo real (RT-qPCR). Com isso, foi possível observar altos níveis relativos de mRNA dos genes PcG nos pacientes quando comparados com os doadores saudáveis. Quando foram comparados os níveis de expressão destes genes de acordo com os subtipos morfológicos, o subtipo LMA-M3 apresentou os níveis mais aumentados, principalmente nos pacientes menores de 8 anos de idade. Com relação aos dados clínicos, apesar da grande variação, a LMA apresentou altos níveis de mRNA dos genes PcG em pacientes com mais de 50.000 leucócitos e a LMA-M3 apresentou níveis aumentados de mRNA destes genes nos pacientes com baixa contagem de plaquetas. Com isso, podemos concluir que apesar da variação nos níveis de mRNA dos genes PcG estudados na LMA, foi possível observar uma correlação destes níveis com os dados clínicos dos pacientes, como os subtipos morfológicos, com a idade, contagem leucocitária e plaquetas na LMA-M3. (AU)


AML is a hematologic malignancy characterized by the abnormal proliferation of myeloid precursors in the bone marrow due to an arrest of differentiation process of these cells. The etiology of leukemia is unknown, but some factors, including the presence of chromosomal translocations may contribute to the emergence of this neoplasia. Three subgroups of genetic alterations have been defined in recent years as the most frequent in primary childhood AML. The group involving core binding factor gene rearrangements: t(8;21)(q22; q22), and inv(16)(p13;q22); leukemias associated with alterations in the MLL gene (11q23 abnormalities in the region ); leukemias associated with PML-RARa rearrangement: t(15;17)(q22;q12). Despite all the knowledge already accumulated regarding the molecular basis of AML leukemogenic processes, changes in epigenetic regulators have been gaining attention in the pathology of leukemia. In this context, the Polycomb Complex genes (PcG) are associated with epigenetic silencing during embryonic development and during carcinogenesis of several tumors, including acute myeloid leukemia (AML). Therefore, the aim of this study was to evaluate a cytogenetic and PcG genes expression profiles in children diagnosed with AML to contribute to the understanding of the biology of this heterogeneous tumor. The bone marrow samples of 84 patients were treated according to standard protocols, and the cytogenetic analysis involving molecular techniques were performed, and were able to demonstrate a high rate of chromosomal abnormalities in 89% of cases. In addition, a high rate of t(15;17)(q22;q12) may be observed, as well as several non -recurring changes could be identified, since several high resolution molecular cytogenetic techniques were used. From the 84 patients' samples, 52 were evaluated for the expression of some of the PcG genes profile, using the real-time PCR methodology. Thus, it was possible to observe mRNA high relative levels of PcG genes in patients compared with healthy donors. When the expression levels of these genes according to the morphological subtypes were compared, AML-M3 subtype showed the most increased levels, mainly in children under the age of 8. Regarding clinical data, despite the wide variation AML showed high mRNA levels of PcG genes in patients with more than 50,000 leukocytes and AML - M3 showed increased mRNA levels of these genes in patients with low platelet counts. Thus, we conclude that despite the variation in mRNA levels of PcG genes studied in AML, we observed a correlation of these levels with clinical patient data, such as morphological subtypes, with age, white blood count and platelets in AML - M3. (AU)


Assuntos
Humanos , Criança , Adolescente , Leucemia Mieloide Aguda/genética , Proteínas Repressoras , Criança , Adolescente , Análise Citogenética
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