RESUMO
Many previous studies have shown a great phylogenetic and biological variability of Trypanosoma cruzi using different molecular and biochemical methods. Populations of T. cruzi were initially clustered into two main lineages called TcI and TcII by the size of the mini-exon PCR product. In the present study, 33 isolates derived from three triatomine taxa, which belong to the Triatoma brasiliensis species complex (Triatoma juazeirensis, Triatoma melanica and Triatoma sherlocki); collected in three distinct areas of Bahia state were characterized by PCR. The isolates were identified by the size of the mini-exon gene, 18S rRNA and 24Sα rRNA amplicons. T. cruzi isolates obtained in sylvatic and intradomiciliar ecotopes, derived from T. juazeirensis and T. melanica, were identified as TcI while the parasites originated from T. sherlocki were characterized as TcI and TcII genotypes, respectively. Those species are present in sylvatic ecotopes but are able to infest intradomiciliar areas. Therefore, it would be important to maintain studies in those localities of Bahia and further investigate the possibilities of Chagas disease transmission. Human disease may occur by any T. cruzi genotype and not only by TcII as it is the case in Amazonia.
Assuntos
Genótipo , Triatoma/parasitologia , Trypanosoma cruzi/genética , Animais , Brasil , Éxons , Genes de Protozoários , RNA de Protozoário/análise , RNA Ribossômico 18S/análise , Especificidade da Espécie , Trypanosoma cruzi/classificação , Trypanosoma cruzi/isolamento & purificaçãoRESUMO
Background: Mismatch repair (MMR)-deficiency analysis is increasingly recommended for all endometrial cancers, as it identifies Lynch syndrome patients, and is emerging as a prognostic classifier to guide adjuvant treatment. The aim of this study was to define the optimal approach for MMR-deficiency testing and to clarify discrepancies between microsatellite instability (MSI) analysis and immunohistochemical (IHC) analysis of MMR protein expression. Patients and methods: Six hundred ninety- six endometrial cancers were analyzed for MSI (pentaplex panel) and MMR protein expression (IHC). Agreement between methodologies was calculated using Cohen's Kappa. MLH1 promoter hypermethylation, dinucleotide microsatellite markers and somatic MMR and POLE exonuclease domain (EDM) gene variants (using next-generation/Sanger sequencing) were analyzed in discordant cases. Results: MSI was found in 180 patients. Complete loss of expression of one or more MMR proteins was observed in 196 cases. A PMS2- and MSH6-antibody panel detected all cases with loss of MMR protein expression. The results of MSI and MMR protein expression were concordant in 655/696 cases (kappa = 0.854, P < 0.001). Ambiguous cases (n = 41, 6%) included: subclonal loss of MMR protein expression (n = 18), microsatellite stable or MSI-low cases with loss of MMR protein expression (n = 20), and MSI-low or MSI-high cases with retained MMR protein expression (n = 3). Most of these cases could be explained by MLH1 promoter hypermethylation. Five of seven cases with solitary loss of PMS2 or MSH6 protein expression carried somatic gene variants. Two MSI-high cases with retained MMR protein expression carried a POLE-EDM variant. Conclusion: MSI and IHC analysis are highly concordant in endometrial cancer. This holds true for cases with subclonal loss of MMR protein expression. Discordant MMR-proficient/MSI-high cases (<1%), may be explained by POLE-EDM variants.
Assuntos
Neoplasias Encefálicas/diagnóstico , Neoplasias Colorretais/diagnóstico , Reparo de Erro de Pareamento de DNA/genética , Neoplasias do Endométrio/genética , Instabilidade de Microssatélites , Síndromes Neoplásicas Hereditárias/diagnóstico , Neoplasias Encefálicas/complicações , Neoplasias Colorretais/complicações , Feminino , Humanos , Imuno-Histoquímica , Síndromes Neoplásicas Hereditárias/complicações , Reação em Cadeia da PolimeraseRESUMO
Teenagers and young adults (TYA) cancer contributes substantially to morbidity and mortality in a population with much to offer society. TYA place distinct challenges upon cancer care services, many reporting feeling marginalized and their needs not being met in adult or paediatric cancer services. Bone tumours such as osteosarcoma and Ewing sarcoma, because of their age at presentation and the complexity of their care, are where challenges in managing (TYA) with cancer have often been most readily apparent. Bone sarcomas may be managed by paediatric or medical oncologists, and require fastidious attention to protocol. A lack of recent improvement in survival in TYA with bone tumours may be linked to a lack of specialist care, poor concordance with therapy in some situations and TYA-specific pharmacology. Participation in clinical trials, particularly of young adults, is low, hindering progress. All these requirements may be best met by a concerted effort to create collaborative care between adult and paediatric experts in bone sarcoma, working together to meet TYA patients' needs.
Assuntos
Neoplasias Ósseas , Osteossarcoma , Adolescente , Adulto , Idade de Início , Neoplasias Ósseas/epidemiologia , Neoplasias Ósseas/terapia , Consenso , Humanos , Osteossarcoma/epidemiologia , Osteossarcoma/terapia , Sarcoma de Ewing/epidemiologia , Sarcoma de Ewing/terapia , Adulto JovemRESUMO
OBJECTIVE: The term 'vulnerable' is often used to describe women facing psychosocial adversity during pregnancy, implying a heightened risk of experiencing suboptimal pregnancy outcomes. While this label might facilitate the pathway to appropriate care, it can be perceived as stigmatizing by the women it intends to help, which could deter their interaction with healthcare services. This study explores how women facing psychosocial adversity before, during and after pregnancy perceive the concept of vulnerability and experience being labeled as such. METHODS: We conducted a thematic analysis of semi-structured, in-depth interviews. Through purposive sampling targeting maximum variation, ten women of diverse backgrounds were included. RESULTS: Three central themes emerged: defining vulnerability, embracing vulnerability and the feeling of being stigmatized. Women perceived vulnerability as an inability to adequately care for themselves or their children, necessitating additional support alongside routine antenatal care. Acceptance of the 'vulnerable' label came when it also acknowledged their proactive efforts and strengths to improve their situation. Conversely, if discussions surrounding vulnerability failed to recognize women's agency - specifically, their personal journeys and the courage needed to seek support - the label was perceived as stigmatizing. CONCLUSIONS: Addressing vulnerability effectively in maternity care requires a nuanced, patient-centered approach, acknowledging both the challenges and strengths of women facing psychosocial adversities. Emphasizing personal narratives and their courage in seeking support can mitigate the stigmatizing effects of the 'vulnerable' label. Integrating these narratives into maternal healthcare practices can foster deeper connections with the women involved, enhancing the overall quality of care.
Assuntos
Cuidado Pré-Natal , Pesquisa Qualitativa , Estigma Social , Populações Vulneráveis , Humanos , Feminino , Gravidez , Adulto , Populações Vulneráveis/psicologia , Cuidado Pré-Natal/psicologia , Gestantes/psicologia , Entrevistas como Assunto , Complicações na Gravidez/psicologia , Estereotipagem , Percepção , Adulto JovemRESUMO
BACKGROUND: Osteosarcoma (OS) is the most common bone tumour in children and adolescents. Despite aggressive therapy regimens, treatment outcomes are unsatisfactory. Targeted delivery of drugs can provide higher effective doses at the site of the tumour, ultimately improving the efficacy of existing therapy. Identification of suitable receptors for drug targeting is an essential step in the design of targeted therapy for OS. METHODS: We conducted a comparative analysis of the surface proteome of human OS cells and osteoblasts using cell surface biotinylation combined with nano-liquid chromatography - tandem mass spectrometry-based proteomics to identify surface proteins specifically upregulated on OS cells. This approach generated an extensive data set from which we selected a candidate to study for its suitability as receptor for targeted treatment delivery to OS. First, surface expression of the ephrin type-A receptor 2 (EPHA2) receptor was confirmed using FACS analysis. Ephrin type-A receptor 2 expression in human tumour tissue was tested using immunohistochemistry. Receptor targeting and internalisation studies were conducted to assess intracellular uptake of targeted modalities via EPHA2. Finally, tissue micro arrays containing cores of human OS tissue were stained using immunohistochemistry and EPHA2 staining was correlated to clinical outcome measures. RESULTS: Using mass spectrometry, a total of 2841 proteins were identified of which 156 were surface proteins significantly upregulated on OS cells compared with human primary osteoblasts. Ephrin type-A receptor 2 was highly upregulated and the most abundant surface protein on OS cells. In addition, EPHA2 was expressed in a vast majority of human OS samples. Ephrin type-A receptor 2 effectively mediates internalisation of targeted adenoviral vectors into OS cells. Patients with EPHA2-positive tumours showed a trend toward inferior overall survival. CONCLUSION: The results presented here suggest that the EPHA2 receptor can be considered an attractive candidate receptor for targeted delivery of therapeutics to OS.
Assuntos
Neoplasias Ósseas/metabolismo , Osteossarcoma/metabolismo , Receptor EphA2/análise , Receptor EphA2/metabolismo , Neoplasias Ósseas/química , Neoplasias Ósseas/tratamento farmacológico , Linhagem Celular Tumoral , Cromatografia Líquida/métodos , Mineração de Dados , Feminino , Citometria de Fluxo/métodos , Humanos , Masculino , Proteínas de Membrana/análise , Proteínas de Membrana/metabolismo , Pessoa de Meia-Idade , Terapia de Alvo Molecular , Osteossarcoma/química , Osteossarcoma/tratamento farmacológico , Prognóstico , Proteoma/análise , Proteoma/metabolismo , Proteômica/métodos , Espectrometria de Massas em Tandem/métodos , Regulação para CimaRESUMO
The allele sizes of polymorphic microsatellite repeats in DNA from human cancers were compared to normal DNA from the same patients. In 16 out of 196 paired samples (8%), we found evidence of an extra allele of a different size in the tumour which was not present in the normal DNA. Sequence analysis confirmed that the extra allele originates from the appropriate locus and that the size change is attributable to alteration in the number of repeat units. This form of instability was more common in tri- and tetranucleotide repeats than in dinucleotide repeats. In any single tumour sample only one repeat in the set examined was abnormal, the remainder showing identical patterns in normal and tumour DNA or evidence of allele loss. The pattern of instability in diverse types of cancer differs from that reported in colorectal neoplasms.
Assuntos
DNA Satélite/genética , Neoplasias/genética , Polimorfismo Genético , Sequências Repetitivas de Ácido Nucleico/genética , Alelos , Sequência de Bases , Neoplasias Encefálicas/genética , Neoplasias da Mama/genética , DNA de Neoplasias/genética , Feminino , Humanos , Masculino , Dados de Sequência Molecular , Distrofia Miotônica/genética , Oligodesoxirribonucleotídeos , Neoplasias Ovarianas/genética , Sarcoma/genética , Análise de Sequência de DNARESUMO
BACKGROUND: Chondrosarcomas are malignant cartilage-forming tumors notorious for their resistance to conventional chemo- and radiotherapy. Postulated explanations describe the inaccessibility due to abundant hyaline cartilaginous matrix, presence of multidrug resistance (MDR) pumps, and expression of anti-apoptotic BCL-2 family members. MATERIALS AND METHODS: We studied the sensitivity of chondrosarcoma cell lines (SW1353, CH2879, JJ012, OUMS27) and two primary cultures for doxorubicin and cisplatin. We examined the role of extracellular matrix using three-dimensional (3D) pellet models and MDR pump activity using fluorescence-activated cell sorter analysis. The role of BCL-2 family members was investigated using the BH3 mimetic ABT-737. RESULTS: Chondrosarcoma cells showed highest resistance to cisplatin. 3D cell pellets, morphologically strongly resembling chondrosarcoma in vivo, confirmed nuclear incorporation of doxorubicin. MDR pump activity was heterogeneous among cultures. Chondrosarcoma cells responded to ABT-737 and combination with doxorubicin led to complete loss of cell viability and apoptosis with cytochrome C release. CONCLUSIONS: Despite MDR pump activity and abundance of hyaline cartilaginous matrix, doxorubicin is able to accumulate in the cell nuclei. By repairing the apoptotic machinery, we were able to sensitize chondrosarcoma cells to doxorubicin and cisplatin, indicating an important role for BCL-2 family members in chemoresistance and a promising new treatment strategy for inoperable chondrosarcoma.
Assuntos
Antineoplásicos/farmacologia , Cisplatino/farmacologia , Doxorrubicina/farmacologia , Proteínas Proto-Oncogênicas c-bcl-2/metabolismo , Proteína bcl-X/metabolismo , Subfamília B de Transportador de Cassetes de Ligação de ATP , Membro 1 da Subfamília B de Cassetes de Ligação de ATP/metabolismo , Membro 2 da Subfamília G de Transportadores de Cassetes de Ligação de ATP , Transportadores de Cassetes de Ligação de ATP/metabolismo , Antineoplásicos/metabolismo , Apoptose/efeitos dos fármacos , Compostos de Bifenilo/farmacologia , Técnicas de Cultura de Células , Núcleo Celular/metabolismo , Proliferação de Células/efeitos dos fármacos , Forma Celular/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Condrossarcoma , Relação Dose-Resposta a Droga , Doxorrubicina/metabolismo , Resistencia a Medicamentos Antineoplásicos , Sinergismo Farmacológico , Expressão Gênica , Células HL-60 , Humanos , Concentração Inibidora 50 , Proteínas Associadas à Resistência a Múltiplos Medicamentos/metabolismo , Proteína de Sequência 1 de Leucemia de Células Mieloides , Proteínas de Neoplasias/metabolismo , Nitrofenóis/farmacologia , Piperazinas/farmacologia , Proteínas Proto-Oncogênicas c-bcl-2/antagonistas & inibidores , Proteínas Proto-Oncogênicas c-bcl-2/genética , Sulfonamidas/farmacologia , Proteína bcl-X/genéticaRESUMO
BACKGROUND: It is important to gain insight into opportunities for secondary prevention of cardiovascular disease. Our aim was to investigate levels and trends in cardiovascular risk factors and drug treatment in Dutch post-myocardial infarction (MI) patients between 2002 and 2006 and to make comparisons with the EUROASPIRE surveys (1999-2007). METHODS: We analysed data from 4837 post-MI patients (aged 69 years, 78% men) from 32 Dutch hospitals, using baseline cross-sectional data from the Alpha Omega Trial. RESULTS: Between 2002 and 2006, significant declines were found in the prevalence of smoking (23% to 16%, p < 0.001), hypercholesterolaemia (≥5 mmol/l; 54% to 27%, p < 0.0001) and hypertension (≥140/90 mmHg; 58% to 48%, p < 0.001). The prevalence of antithrombotic drugs was high (97%). The prevalence of lipid-modifying drugs and antihypertensives was high, and increased (74% to 90%, p < 0.0001 and 82% to 93%, p < 0.001, respectively). The prevalence of obesity (27%) was high in 2002 and decreased to 24% in 2006, albeit not significantly. Diabetes prevalence was high and increased between 2002 and 2006 (18% to 22%, p = 0.02). In comparison with EUROASPIRE patients, who were on average 8-10 years younger, our study in 2006 included patients with lower levels of obesity, hypertension, hypercholesterolaemia, diabetes and lower use of antiplatelets and ß-blockers, but similar levels of lipid-modifying drugs. CONCLUSIONS: This study showed that older Dutch post-MI patients were adequately treated with drugs, and that risk factors reached lower levels than in the younger EUROASPIRE patients. However, there is room for improvement in diet and lifestyle, given the high prevalence of smoking, obesity, and diabetes.
RESUMO
Mucosal melanomas are rare and only a small portion bear BRAF mutations while cutaneous melanomas have a much higher prevalence and often harbor BRAF mutations. We present two cases in which, after a malignant melanocytic mucosal lesion with a BRAF mutation was found, the primary cutaneous source was identified and clonality confirmed between the lesions. In both cases, primary lesions occurred on the scalp, an often-overlooked site. Both lesions showed signs of regression implying that in due time these lesions could have been fully regressed and might never have been detected. In that case, the metastatic mucosal lesion would erroneously be identified as a BRAF-mutated mucosal melanoma. These cases give warrant; a careful dermatological inspection should be instigated when confronted with a BRAF-mutated mucosal melanoma. We hypothesize that some BRAF-mutated mucosal melanomas might actually represent metastases of regressed cutaneous melanomas.
Assuntos
Melanoma , Neoplasias Cutâneas , Humanos , Melanoma/genética , Melanoma/patologia , Mutação , Proteínas Proto-Oncogênicas B-raf/genética , Couro Cabeludo/patologia , Neoplasias Cutâneas/genética , Neoplasias Cutâneas/patologiaRESUMO
INTRODUCTION: In 1-3% of non-small cell lung cancer (NSCLC) human epidermal growth factor 2 (HER2) mutations are identified as a genomic driver. Nevertheless, no HER2-targeted treatment is approved for NSCLC. In the Drug Rediscovery Protocol (DRUP), patients are treated with off-label drugs based on their molecular profile. Here, we present the results of the cohort 'trastuzumab/pertuzumab for HER2 exon20 mutation positive (HER2m+) NSCLC'. METHODS: Patients with treatment refractory, advanced HER2m+ NSCLC with measurable disease (RECISTv1.1) were eligible. Treatment with intravenous trastuzumab combined with pertuzumab every 3 weeks was administered. The primary end-point was clinical benefit (CB: either objective response or stable disease ≥ 16 weeks). Patients were enrolled using a Simon-like 2-stage design, with 8 patients in stage 1 and up to 24 patients in stage 2 if at least 1 patient had CB in stage 1. At baseline, a biopsy for biomarker analysis, including whole genome sequencing, was obtained. RESULTS: Twenty-four evaluable patients were enrolled and treated between May 2017 and August 2020. CB was observed in 9 patients (38%); including an objective response rate of 8.3% (2 patients had a partial response) and 7 patients with stable disease ≥ 16 weeks. The most frequently observed HER2 mutation was p.Y772_A775dup (71%, n = 20). Median follow-up was 13 months, median progression-free survival and overall survival 4 (95% CI 3-6) and 10 months (95% CI 4 - not reached), respectively. Whole genome sequencing data (available for 67% of patients) confirmed the inclusion mutation in all cases. No unexpected toxicity was observed. CONCLUSION: Despite the fact that the study did meet its primary end-point, trastuzumab/pertuzumab was only marginally active in a subset of patients with heavily pre-treated HER2m+ NSCLC.
Assuntos
Neoplasias da Mama , Carcinoma Pulmonar de Células não Pequenas , Neoplasias Pulmonares , Anticorpos Monoclonais Humanizados , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Neoplasias da Mama/tratamento farmacológico , Carcinoma Pulmonar de Células não Pequenas/tratamento farmacológico , Carcinoma Pulmonar de Células não Pequenas/genética , Éxons , Feminino , Humanos , Neoplasias Pulmonares/tratamento farmacológico , Neoplasias Pulmonares/genética , Receptor ErbB-2/metabolismo , Trastuzumab/uso terapêuticoRESUMO
Previous studies on the counsellees' perception of DNA test results did not clarify whether counsellees were asked about their recollections or interpretations, and focused only on patients' own risks and not on the likelihood that cancer is heritable in the family. We tested differences and correlations of four perception aspects: recollections and interpretations of both cancer risks and heredity likelihood. In a retrospective study, women tested for BRCA1/2 on average, 5 years ago, completed questionnaires about their perception. Participants had received an unclassified variant (n = 76), uninformative (n = 76) or pathogenic mutation (n = 51) result in BRCA1/2. Analyses included t-tests, correlations and structural equation modelling. The counsellees' perception showed to consist of four distinctive phenomena: recollections and interpretations of cancer risks and of heredity likelihood. This distinctiveness was suggested by significant differences between these perception variables. Moderate to strong correlations were found between these variables, suggesting that these differences between variables were consistent. The relationships between these variables were not influenced by actually communicated DNA test results, sociodemographics, medical and pedigree information, or framing of cancer risk questions. The largest differences between recollections and interpretations were found in the unclassified variant group and the smallest in uninformatives. Cancer risks and heredity likelihood correlated least in the pathogenic mutation group. Communication of ambiguous genetic information enlarged the differences. To understand the counsellees' perception of genetic counselling, researchers should study recollections and interpretations of cancer risks and heredity likelihood. Genetic counsellors should explicitly address the counsellees' recollections and interpretations, and be aware of possible inaccuracies.
Assuntos
Neoplasias da Mama , Aconselhamento Genético , Testes Genéticos/estatística & dados numéricos , Rememoração Mental , Neoplasias Ovarianas , Percepção , Risco , Neoplasias da Mama/genética , Neoplasias da Mama/psicologia , Feminino , Genes BRCA1 , Genes BRCA2 , Humanos , Pessoa de Meia-Idade , Modelos Teóricos , Neoplasias Ovarianas/genética , Neoplasias Ovarianas/psicologia , Estudos Retrospectivos , Inquéritos e QuestionáriosRESUMO
Chagas disease is an enzootic disease, in which the flagellate Trypanosoma cruzi infects a large variety of animals. Humans are accidentally infected due to the migration into wild environments. To identify T. cruzi discrete typing units (DTUs), 19 Brazilian isolates from different biomes and hosts were analyzed by PCR amplification of 24Sα rRNA, 18S rRNA and mini-exon gene sequences. The majority of the isolates was classified as TcIIb (TcII) but subtypes TcIIc (TcIII) and TcIId (TcV) were also identified. In addition, in monkeys TcI was detected.
Assuntos
Doença de Chagas/parasitologia , Trypanosoma cruzi/classificação , Animais , Brasil , Didelphis/parasitologia , Éxons/genética , Genótipo , Humanos , Leontopithecus/parasitologia , Reação em Cadeia da Polimerase , Doenças dos Primatas/parasitologia , Primatas , RNA Ribossômico/genética , Doenças dos Roedores/parasitologia , Roedores , Triatominae/parasitologia , Trypanosoma cruzi/genéticaRESUMO
The molecular background of a significant proportion of spitzoid neoplasms is still unknown. Recently, activating mutations in MAP2K1 have been described in a few spitzoid lesions, but not in benign Spitz nevi. We report four cases of melanocytic tumors with spitzoid features in which a MAP2K1 mutation was detected. The lesions did not show a single distinct phenotype and ranged from benign to malignant. Two cases resembled desmoplastic Spitz nevi. Based on the combination of morphological, immunohistochemical, and molecular findings, one case was classified as benign, one as probably benign, possibly intermediate low-grade (MELTUMP-melanocytic tumor of unknown malignant potential), one case was classified as intermediate (MELTUMP), and one case was considered a superficial spreading melanoma with spitzoid features. Based on this, we conclude that MAP2K1 mutations can indicate a spitzoid genetic signature and can be found in both benign and malignant spitzoid neoplasms.
Assuntos
Biomarcadores Tumorais/genética , MAP Quinase Quinase 1/genética , Melanoma/genética , Mutação , Nevo de Células Epitelioides e Fusiformes/genética , Neoplasias Cutâneas/genética , Adolescente , Idoso , Feminino , Predisposição Genética para Doença , Humanos , Masculino , Melanoma/enzimologia , Melanoma/patologia , Pessoa de Meia-Idade , Nevo de Células Epitelioides e Fusiformes/enzimologia , Nevo de Células Epitelioides e Fusiformes/patologia , Fenótipo , Neoplasias Cutâneas/enzimologia , Neoplasias Cutâneas/patologiaRESUMO
BACKGROUND: Osteosarcoma is the most prevalent primary malignant bone tumour in children and young adults, with poor survival in 40% of patients. To identify the signalling pathways involved in tumourigenesis, we compared gene expression in osteosarcoma with that in its presumed normal counterparts. METHODS: Genome-wide expression profiles were generated from 25 high-grade central osteosarcoma prechemotherapy biopsies, 5 osteoblastomas, 5 mesenchymal stem cell (MSC) populations and these same MSCs differentiated into osteoblasts. Genes that were differentially expressed were analysed in the context of the pathways in which they function using the GenMAPP programme. RESULTS: MSCs, osteoblasts, osteoblastomas and osteosarcomas clustered separately and thousands of differentially expressed genes were identified. The most significantly altered pathways are involved in cell cycle regulation and DNA replication. Several upstream components of the Wnt signalling pathway are downregulated in osteosarcoma. Two genes involved in degradation of beta-catenin protein, the key effectors of Wnt signalling, Axin and GSK3-beta, show decreased expression, suggesting that Wnt signalling is no longer under the control of regular signals. Comparing benign osteoblastomas with osteosarcomas identified cell cycle regulation as the most prominently changed pathway. CONCLUSION: These results show that upregulation of the cell cycle and downregulation of Wnt signalling have an important role in osteosarcoma genesis. Gene expression differences between highly malignant osteosarcoma and benign osteoblastoma involve cell cycle regulation.
Assuntos
Neoplasias Ósseas/patologia , Células-Tronco Mesenquimais/patologia , Células-Tronco Neoplásicas/patologia , Osteossarcoma/patologia , Adolescente , Adulto , Neoplasias Ósseas/genética , Neoplasias Ósseas/metabolismo , Ciclo Celular/fisiologia , Diferenciação Celular , Linhagem Celular Tumoral , Criança , Pré-Escolar , Regulação para Baixo , Feminino , Perfilação da Expressão Gênica , Humanos , Masculino , Células-Tronco Mesenquimais/metabolismo , Células-Tronco Neoplásicas/metabolismo , Osteoblastoma/genética , Osteoblastoma/metabolismo , Osteoblastoma/patologia , Osteossarcoma/genética , Osteossarcoma/metabolismo , Transdução de Sinais , Regulação para Cima , Proteínas Wnt/genética , Proteínas Wnt/metabolismo , Adulto JovemRESUMO
Protease expression among TCI and TCII field isolates was analysed. Gelatin-containing gels revealed hydrolysis bands with molecular masses ranging from 45 to 66 kDa. The general protease expression profile showed that TCII isolates presented higher heterogeneity compared to TCI. By utilizing protease inhibitors, we showed that all active proteases at acid pH are cysteine-proteases and all proteases active at alkaline pH are metalloproteases. However, the expression of cruzipain, the T. cruzi major cysteine-protease, did not reproduce a heterogeneous TCII cysteine zymogram profile. Dendogram analyses based on presence/absence matrices of proteases and cruzipain bands showed a TCI separation from the TCII group with 50-60% similarity. We suggest that the observed cysteine protease diversification contributes to differential host infection between TCI and II genotypes.
Assuntos
Cisteína Endopeptidases/genética , Peptídeo Hidrolases/genética , Trypanosoma cruzi/enzimologia , Animais , Western Blotting , Cisteína Endopeptidases/metabolismo , Regulação Enzimológica da Expressão Gênica/efeitos dos fármacos , Genótipo , Interações Hospedeiro-Parasita/genética , Filogenia , Inibidores de Proteases/farmacologia , Proteínas de Protozoários , Trypanosoma cruzi/genéticaRESUMO
Many publications have documented loss of heterozygosity (LOH) on many different chromosomes in a wide variety of tumours, implicating the existence of multiple tumour suppressor genes (TSGs). Knudson's two-hit hypothesis predicts that these LOH events are the second step in the inactivation of both alleles of a TSG. However, to date the number of TSGs identified that are inactivated mainly at the somatic level in cancers and are not inherited has remained disappointingly small. Here we postulate that the accurate mapping of LOH events in a series of tumours to define a common LOH region is greatly confounded by deficient LOH detection, genetic instability and intertumour heterogeneity. Finding the TSGs in chromosomal regions of frequent LOH might require 'brute-force' genomic approaches.
Assuntos
Perda de Heterozigosidade , Modelos Genéticos , Neoplasias/genética , Alelos , Mapeamento Cromossômico , Cocarcinogênese , Genes Supressores de Tumor , Humanos , Neoplasias/etiologiaRESUMO
An evaluation was made on how the landscape and cattle ranching affect the transmission cycles and the patterns of tripanosomatid infection (Trypanosoma cruzi and Trypanosoma evansi) of small wild mammals in the Pantanal. This region comprises a large natural environment with a multiplicity of habitats, wide variety of biodiversity besides the presence of livestock. T. cruzi and T. evansi infections were evaluated by parasitological and serological methods in one preserved and one cattle ranching area. The diversity of the small mammal fauna showed to be the same in the two studied areas, however, their relative abundance was different. Distinct enzootiological scenarios of both trypanosomatids could be observed. Transmission of T. cruzi occurred mainly in forested areas, in the two study areas, while T. evansi occurred dispersed among all habitats studied in the unpreserved area. The arboreal rodent Oecomys mamorae, the most abundant species in both areas, displayed high T. cruzi and T. evansi serum prevalence and parasitemias. Also, the caviomorph rodent Thrichomys pachyurus was shown to be an important host due to its expressive relative abundance, prevalence of infection by both trypanosomatid species and a broad range use of habitats. The role of the small mammal fauna in the transmission cycle of both trypanosomes species seems to be distinct according to land use since we found a broad range of T. evansi infected hosts in the preserved area in contrast to cattle ranching area and a half number of the rodents species infected with T. cruzi in unpreserved in comparison to protect area. The present study showed that cattle ranching in this study area did not enhance overall prevalence of T. cruzi infection among small wild mammals. Together with the observation that small mammals diversity in FA is similar to RN area suggest that ranching activity may also not necessarily conduct to biodiversity loss or risk of Chagas disease.
Assuntos
Animais Selvagens/parasitologia , Doença de Chagas/veterinária , Ecossistema , Marsupiais/parasitologia , Doenças dos Roedores/epidemiologia , Roedores/parasitologia , Trypanosoma cruzi/isolamento & purificação , Trypanosoma/isolamento & purificação , Tripanossomíase/veterinária , Criação de Animais Domésticos , Animais , Anticorpos Antiprotozoários/sangue , Brasil/epidemiologia , Bovinos , Doença de Chagas/epidemiologia , Doença de Chagas/parasitologia , Doença de Chagas/transmissão , Parasitemia/epidemiologia , Parasitemia/parasitologia , Parasitemia/veterinária , Prevalência , Doenças dos Roedores/parasitologia , Trypanosoma/classificação , Trypanosoma/imunologia , Trypanosoma cruzi/imunologia , Tripanossomíase/epidemiologia , Tripanossomíase/parasitologia , Tripanossomíase/transmissãoRESUMO
Maps are a useful tool that permits correlation of landscapes with hotspots of parasite transmission. Here, they were used as a tool for geovisualization to evaluate variables involved in the transmission of Trypanosoma cruzi among small wild mammals in an area endemic for Chagas disease, the "Serra da Capivara" National Park (PARNA) and its surroundings in Piauí State, Northeast Brazil. The implementation of a Geographical Information System (GIS) allowed the observation that a previously noted aggregated distribution of Triatoma sordida and Triatoma brasiliensis, T. cruzi prevalence and infection pattern of small wild mammals was directly or indirectly influenced by the local relief and human action. Small mammalian species diversity was higher in mesic refugia inside the park and in its buffer zone and lower in the disturbed area by anthropic activities. Didelphis albiventris was more abundant in the areas affected by human action. Thrichomys laurentius demonstrated to be an eclectic species and a competent reservoir of T. cruzi, being infected in all study areas. Small wild mammals infected with the TCII genotype of T. cruzi were localized only in the buffer zone of PARNA while TCI infected specimens were found in both areas, inside the PARNA and its buffer zone. The impact of biodiversity loss on the transmission cycle of T. cruzi in the wild environment was discussed.
Assuntos
Animais Selvagens/parasitologia , Doença de Chagas/veterinária , Conservação dos Recursos Naturais , Sistemas de Informação Geográfica , Mamíferos/parasitologia , Trypanosoma cruzi/isolamento & purificação , Animais , Brasil/epidemiologia , Carnívoros/parasitologia , Doença de Chagas/epidemiologia , Reservatórios de Doenças , Humanos , Marsupiais/parasitologia , Roedores/parasitologia , Triatominae/classificação , Triatominae/parasitologia , Triatominae/fisiologia , Trypanosoma cruzi/classificação , Trypanosoma cruzi/genéticaRESUMO
The cDNAs encoding an intestinal defensin (def1) and lysozyme (lys1) of the reduviid bug Triatoma brasiliensis have been amplified by PCR using specific oligonucleotide primers and 5'- and 3'-RACE, cloned and sequenced. The 576 bp clone has an open reading frame of 282 bp and encodes a pre-prodefensin with 94 amino acid residues, containing a putative signal and activation peptide cleavage site at Ser19 and Arg51, respectively. The genomic DNA contains a second defensin gene with similar characteristics, 88.3% identity and also one intron of 107 nucleotides. The 538 bp clone has an open reading frame of 417 bp, encoding a pre-lysozyme with 139 amino acid residues. The putative signal peptide is cleaved at alanine 18. Using whole mount in situ hybridization, high expression of both genes has been found, distributed uniformly throughout the entire cardia and the blood-storing stomach and to a much lower extent in the digesting small intestine. Using quantitative real-time PCR, the expression level of def1 was also shown to be very low in small intestine, rectum and salivary glands; in the stomach, expression was 500-2500 times higher than in the cardia and fat body. No expression of lys1 could be detected in the salivary glands and rarely a very low expression in the small intestine, rectum and fat body. Lys1 expression in the stomach was 60-300 times higher than in the cardia. Comparing the levels in unfed fifth instars and up to 15 days after feeding, a strong def1 induction was evident in the fat body at 15 days after feeding and in the stomach a maximum level of def1 and lys1 at 5 days after feeding.
Assuntos
Defensinas/genética , Expressão Gênica , Genes de Insetos , Insetos/genética , Muramidase/genética , Sequência de Aminoácidos , Animais , Sequência de Bases , Primers do DNA , DNA Complementar , Dados de Sequência Molecular , Reação em Cadeia da Polimerase , Homologia de Sequência de AminoácidosRESUMO
BACKGROUND: Epidemiologic studies have shown that the association of genital human papillomavirus (HPV) with cervical cancer is strong, independent of other risk factors, and consistent in several countries. There are more than 20 different cancer-associated HPV types, but little is known about their geographic variation. PURPOSE: Our aim was to determine whether the association between HPV infection and cervical cancer is consistent worldwide and to investigate geographic variation in the distribution of HPV types. METHODS: More than 1000 specimens from sequential patients with invasive cervical cancer were collected and stored frozen at 32 hospitals in 22 countries. Slides from all patients were submitted for central histologic review to confirm the diagnosis and to assess histologic characteristics. We used polymerase chain reaction-based assays capable of detecting more than 25 different HPV types. A generalized linear Poisson model was fitted to the data on viral type and geographic region to assess geographic heterogeneity. RESULTS: HPV DNA was detected in 93% of the tumors, with no significant variation in HPV positivity among countries. HPV 16 was present in 50% of the specimens, HPV 18 in 14%, HPV 45 in 8%, and HPV 31 in 5%. HPV 16 was the predominant type in all countries except Indonesia, where HPV 18 was more common. There was significant geographic variation in the prevalence of some less common virus types. A clustering of HPV 45 was apparent in western Africa, while HPV 39 and HPV 59 were almost entirely confined to Central and South America. In squamous cell tumors, HPV 16 predominated (51% of such specimens), but HPV 18 predominated in adenocarcinomas (56% of such tumors) and adenosquamous tumors (39% of such tumors). CONCLUSIONS: Our results confirm the role of genital HPVs, which are transmitted sexually, as the central etiologic factor in cervical cancer worldwide. They also suggest that most genital HPVs are associated with cancer, at least occasionally. IMPLICATION: The demonstration that more than 20 different genital HPV types are associated with cervical cancer has important implications for cervical cancer-prevention strategies that include the development of vaccines targeted to genital HPVs.