Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 25
Filtrar
Mais filtros

Base de dados
País/Região como assunto
Tipo de documento
Intervalo de ano de publicação
1.
J Environ Manage ; 229: 102-111, 2019 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-30001886

RESUMO

Volunteers are increasingly involved in the delivery of nature conservation policies, usually supported by a twofold rationale: volunteering can (a) enhance citizen participation in environmental governance and (b) ensure a workforce is in place to support conservation work in times of budget shortages. Here, we ask how these two rationales correspond to volunteers' own motivations to engage in a specific nature conservation activity, namely the control of invasive alien species (IAS). We use qualitative interviews with professional project managers, local group leaders, and volunteers to examine the interactions between policies aiming to rationalise the management of IAS and the motivations for and goals of volunteer engagement. Our findings suggest that although volunteering can lead to positive conservation outcomes, satisfying experiences and empowerment, the different interests do not always align in practice. We investigate the implications of strategies that aim to improve the efficiency of invasive species and volunteer management, and discuss organisational arrangements that reconcile different objectives.


Assuntos
Espécies Introduzidas , Humanos , Motivação , Reino Unido , Voluntários
2.
Blood ; 121(13): 2415-23, 2013 Mar 28.
Artigo em Inglês | MEDLINE | ID: mdl-23321258

RESUMO

The aim of our study was to analyze the factors contributing to heterogeneity of prognosis in patients with hyperdiploidy>50 chromosomes (HD>50), a group of B-cell precursor acute lymphoblastic leukemia with favorable outcome. The 541 HD>50 patients registered prospectively in the 58951 European Organisation for Research and Treatment of Cancer (EORTC) Children's Leukemia Group (CLG) trial, identified by karyotype (446 patients) and by DNA index (DI) (490 patients), had a 6-year event-free survival (EFS) of 89.0% (standard error [SE] = 1.5%) and a 6-year overall survival (OS) of 95.9% (SE = 0.9%). The strongest prognostic factor was the modal number of chromosomes (MNC): the 6-year EFS of 51-53, 54-57, and 58-66 MNC groups were 80%, 89%, and 99%, respectively (P < .0001). Ploidy assessed by DI was also a favorable factor: the higher the DI, the better the outcome. The 6-year EFS of the 3 subgroups of DI < 1.16/≥1.16-<1.24/≥1.24 were 83%, 90%, and 95%, respectively (P = .009). All usual combinations of trisomies (chromosomes 4, 10, 17, 18) were significant favorable factors but had lower EFS when MNC was lower than 58. In multivariate analysis, MNC remained the strongest factor. Consequently, the best indicator for excellent outcome was ploidy assessed by karyotype because patients with 58-66 chromosomes stood every chance of being cured (OS of 100% at 6-year follow-up) with less-intensive therapy. This trial was registered at www.clinicaltrials.gov as #NCT00003728. Registered: http://www.eortc.org/, http://clinicaltrials.gov/show/NCT00003728.


Assuntos
Ensaios Clínicos como Assunto , Diploide , Poliploidia , Leucemia-Linfoma Linfoblástico de Células Precursoras B/genética , Leucemia-Linfoma Linfoblástico de Células Precursoras B/terapia , Adolescente , Idade de Início , Criança , Pré-Escolar , Aberrações Cromossômicas/estatística & dados numéricos , Cromossomos/genética , Ensaios Clínicos como Assunto/métodos , Feminino , Seguimentos , Heterogeneidade Genética , Humanos , Lactente , Recém-Nascido , Cariotipagem , Masculino , Leucemia-Linfoma Linfoblástico de Células Precursoras B/epidemiologia , Leucemia-Linfoma Linfoblástico de Células Precursoras B/patologia , Indução de Remissão
3.
BMC Evol Biol ; 13: 194, 2013 Sep 12.
Artigo em Inglês | MEDLINE | ID: mdl-24028551

RESUMO

BACKGROUND: In vertebrates, it has been repeatedly demonstrated that genes encoding proteins involved in pathogen-recognition by adaptive immunity (e.g. MHC) are subject to intensive diversifying selection. On the other hand, the role and the type of selection processes shaping the evolution of innate-immunity genes are currently far less clear. In this study we analysed the natural variation and the evolutionary processes acting on two genes involved in the innate-immunity recognition of Microbe-Associated Molecular Patterns (MAMPs). RESULTS: We sequenced genes encoding Toll-like receptor 4 (Tlr4) and 7 (Tlr7), two of the key bacterial- and viral-sensing receptors of innate immunity, across 23 species within the subfamily Murinae. Although we have shown that the phylogeny of both Tlr genes is largely congruent with the phylogeny of rodents based on a comparably sized non-immune sequence dataset, we also identified several potentially important discrepancies. The sequence analyses revealed that major parts of both Tlrs are evolving under strong purifying selection, likely due to functional constraints. Yet, also several signatures of positive selection have been found in both genes, with more intense signal in the bacterial-sensing Tlr4 than in the viral-sensing Tlr7. 92% and 100% of sites evolving under positive selection in Tlr4 and Tlr7, respectively, were located in the extracellular domain. Directly in the Ligand-Binding Region (LBR) of TLR4 we identified two rapidly evolving amino acid residues and one site under positive selection, all three likely involved in species-specific recognition of lipopolysaccharide of gram-negative bacteria. In contrast, all putative sites of LBRTLR7 involved in the detection of viral nucleic acids were highly conserved across rodents. Interspecific differences in the predicted 3D-structure of the LBR of both Tlrs were not related to phylogenetic history, while analyses of protein charges clearly discriminated Rattini and Murini clades. CONCLUSIONS: In consequence of the constraints given by the receptor protein function purifying selection has been a dominant force in evolution of Tlrs. Nevertheless, our results show that episodic diversifying parasite-mediated selection has shaped the present species-specific variability in rodent Tlrs. The intensity of diversifying selection was higher in Tlr4 than in Tlr7, presumably due to structural properties of their ligands.


Assuntos
Evolução Molecular , Murinae/classificação , Murinae/genética , Receptor 4 Toll-Like/genética , Receptor 7 Toll-Like/genética , Animais , Imunidade Inata , Murinae/imunologia , Filogenia , Estrutura Terciária de Proteína , Especificidade da Espécie , Receptor 4 Toll-Like/química , Receptor 4 Toll-Like/imunologia , Receptor 7 Toll-Like/química , Receptor 7 Toll-Like/imunologia
4.
Mol Ecol ; 22(4): 1019-34, 2013 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-23278980

RESUMO

Black rats are major invasive vertebrate pests with severe ecological, economic and health impacts. Remarkably, their evolutionary history has received little attention, and there is no firm agreement on how many species should be recognized within the black rat complex. This species complex is native to India and Southeast Asia. According to current taxonomic classification, there are three taxa living in sympatry in several parts of Thailand, Cambodia and Lao People's Democratic Republic, where this study was conducted: two accepted species (Rattus tanezumi, Rattus sakeratensis) and an additional mitochondrial lineage of unclear taxonomic status referred to here as 'Rattus R3'. We used extensive sampling, morphological data and diverse genetic markers differing in rates of evolution and parental inheritance (two mitochondrial DNA genes, one nuclear gene and eight microsatellite loci) to assess the reproductive isolation of these three taxa. Two close Asian relatives, Rattus argentiventer and Rattus exulans, were also included in the genetic analyses. Genetic analyses revealed discordance between the mitochondrial and nuclear data. Mitochondrial phylogeny studies identified three reciprocally monophyletic clades in the black rat complex. However, studies of the phylogeny of the nuclear exon interphotoreceptor retinoid-binding protein gene and clustering and assignation analyses with eight microsatellites failed to separate R. tanezumi and R3. Morphometric analyses were consistent with nuclear data. The incongruence between mitochondrial and nuclear (and morphological) data rendered R. tanezumi/R3 paraphyletic for mitochondrial lineages with respect to R. sakeratensis. Various evolutionary processes, such as shared ancestral polymorphism and incomplete lineage sorting or hybridization with massive mitochondrial introgression between species, may account for this unusual genetic pattern in mammals.


Assuntos
Evolução Molecular , Filogenia , Ratos/genética , Isolamento Reprodutivo , Animais , Sudeste Asiático , Núcleo Celular/genética , DNA Mitocondrial/genética , Especiação Genética , Variação Genética , Repetições de Microssatélites , Modelos Genéticos , Análise de Sequência de DNA
5.
Blood ; 117(15): e161-70, 2011 Apr 14.
Artigo em Inglês | MEDLINE | ID: mdl-21325596

RESUMO

Fanconi anemia (FA) is a genetic condition associated with bone marrow (BM) failure, myelodysplasia (MDS), and acute myeloid leukemia (AML). We studied 57 FA patients with hypoplastic or aplastic anemia (n = 20), MDS (n = 18), AML (n = 11), or no BM abnormality (n = 8). BM samples were analyzed by karyotype, high-density DNA arrays with respect to paired fibroblasts, and by selected oncogene sequencing. A specific pattern of chromosomal abnormalities was found in MDS/AML, which included 1q+ (44.8%), 3q+ (41.4%), -7/7q (17.2%), and 11q- (13.8%). Moreover, cryptic RUNX1/AML1 lesions (translocations, deletions, or mutations) were observed for the first time in FA (20.7%). Rare mutations of NRAS, FLT3-ITD, MLL-PTD, ERG amplification, and ZFP36L2-PRDM16 translocation, but no TP53, TET2, CBL, NPM1, and CEBPα mutations were found. Frequent homozygosity regions were related not to somatic copy-neutral loss of heterozygosity but to consanguinity, suggesting that homologous recombination is not a common progression mechanism in FA. Importantly, the RUNX1 and other chromosomal/genomic lesions were found at the MDS/AML stages, except for 1q+, which was found at all stages. These data have implications for staging and therapeutic managing in FA patients, and also to analyze the mechanisms of clonal evolution and oncogenesis in a background of genomic instability and BM failure.


Assuntos
Subunidade alfa 2 de Fator de Ligação ao Core/genética , Anemia de Fanconi/genética , Instabilidade Genômica/genética , Leucemia Mieloide Aguda/genética , Síndromes Mielodisplásicas/genética , Adolescente , Adulto , Medula Óssea/fisiologia , Criança , Pré-Escolar , Anemia de Fanconi/complicações , Feminino , Dosagem de Genes/genética , Perfilação da Expressão Gênica , Regulação Leucêmica da Expressão Gênica , Genes Supressores de Tumor , Homozigoto , Humanos , Leucemia Mieloide Aguda/etiologia , Masculino , Pessoa de Meia-Idade , Síndromes Mielodisplásicas/etiologia , Nucleofosmina , Polimorfismo de Nucleotídeo Único , Adulto Jovem
6.
Blood ; 115(15): 3089-97, 2010 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-20160164

RESUMO

PAX5 is the main target of somatic mutations in acute B lymphoblastic leukemia (B-ALL). We analyzed 153 adult and child B-ALL harboring karyotypic abnormalities at chromosome 9p, to determine the frequency and the nature of PAX5 alterations. We found PAX5 internal rearrangements in 21% of the cases. To isolate fusion partners, we used classic and innovative techniques (rolling circle amplification-rapid amplification of cDNA ends) and single nucleotide polymorphism-comparative genomic hybridization arrays. Recurrent and novel fusion partners were identified, including NCoR1, DACH2, GOLGA6, and TAOK1 genes showing the high variability of the partners. We noted that half the fusion genes can give rise to truncated PAX5 proteins. Furthermore, malignant cells carrying PAX5 fusion genes displayed a simple karyotype. These data strongly suggest that PAX5 fusion genes are early players in leukemogenesis. In addition, PAX5 deletion was observed in 60% of B-ALL with 9p alterations. Contrary to cases with PAX5 fusions, deletions were associated with complex karyotypes and common recurrent translocations. This supports the hypothesis of the secondary nature of the deletion. Our data shed more light on the high variability of PAX5 alterations in B-ALL. Therefore, it is probable that gene fusions occur early, whereas deletions should be regarded as a late/secondary event.


Assuntos
Análise Citogenética , Mutação/genética , Fator de Transcrição PAX5/genética , Leucemia-Linfoma Linfoblástico de Células Precursoras B/genética , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Pontos de Quebra do Cromossomo , Cromossomos Humanos Par 9/genética , Clonagem Molecular , Estudos de Coortes , Feminino , França , Regulação Leucêmica da Expressão Gênica , Humanos , Cariotipagem , Masculino , Pessoa de Meia-Idade , Proteínas de Fusão Oncogênica/genética , Proteínas de Fusão Oncogênica/metabolismo , Leucemia-Linfoma Linfoblástico de Células Precursoras B/patologia , Adulto Jovem
7.
J Pediatr Hematol Oncol ; 33(7): 570-2, 2011 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-21941152

RESUMO

Cryptosporidium is recognized as a cause of diarrhea associated with a high mortality in immunocompromised patients. We report on 2 pediatric cases of cryptosporidiosis during maintenance chemotherapy of acute lymphoblastic leukemia. The patients presented severe diarrheas, 1 of them was complicated by a cholangitis. Withdrawal of immunosuppressive treatments and adjunction of an adequate antiparasitic treatment cured the Cryptosporidium infection in both cases.


Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica/efeitos adversos , Criptosporidiose/complicações , Quimioterapia de Manutenção , Leucemia-Linfoma Linfoblástico de Células Precursoras/complicações , Adolescente , Protocolos de Quimioterapia Combinada Antineoplásica/administração & dosagem , Antiparasitários/uso terapêutico , Pré-Escolar , Criptosporidiose/diagnóstico , Criptosporidiose/tratamento farmacológico , Humanos , Quimioterapia de Manutenção/efeitos adversos , Masculino , Leucemia-Linfoma Linfoblástico de Células Precursoras/diagnóstico , Leucemia-Linfoma Linfoblástico de Células Precursoras/tratamento farmacológico , Resultado do Tratamento
8.
BMC Evol Biol ; 10: 184, 2010 Jun 18.
Artigo em Inglês | MEDLINE | ID: mdl-20565819

RESUMO

BACKGROUND: Rodents are recognized as hosts for at least 60 zoonotic diseases and may represent a serious threat for human health. In the context of global environmental changes and increasing mobility of humans and animals, contacts between pathogens and potential animal hosts and vectors are modified, amplifying the risk of disease emergence. An accurate identification of each rodent at a specific level is needed in order to understand their implications in the transmission of diseases. Among the Muridae, the Rattini tribe encompasses 167 species inhabiting South East Asia, a hotspot of both biodiversity and emerging and re-emerging diseases. The region faces growing economical development that affects habitats, biodiversity and health. Rat species have been demonstrated as significant hosts of pathogens but are still difficult to recognize at a specific level using morphological criteria. DNA-barcoding methods appear as accurate tools for rat species identification but their use is hampered by the need of reliable identification of reference specimens. In this study, we explore and highlight the limits of the current taxonomy of the Rattini tribe. RESULTS: We used the DNA sequence information itself as the primary information source to establish group membership and estimate putative species boundaries. We sequenced two mitochondrial and one nuclear genes from 122 rat samples to perform phylogenetic reconstructions. The method of Pons and colleagues (2006) that determines, with no prior expectations, the locations of ancestral nodes defining putative species was then applied to our dataset. To give an appropriate name to each cluster recognized as a putative species, we reviewed information from the literature and obtained sequences from a museum holotype specimen following the ancient DNA criteria. CONCLUSIONS: Using a recently developed methodology, this study succeeds in refining the taxonomy of one of the most difficult groups of mammals. Most of the species expected within the area were retrieved but new putative species limits were also indicated, in particular within Berylmys and Rattus genera, where future taxonomic studies should be directed. Our study lays the foundations to better investigate rodent-born diseases in South East Asia and illustrates the relevance of evolutionary studies for health and medical sciences.


Assuntos
Filogenia , Ratos/classificação , Animais , Sudeste Asiático , Teorema de Bayes , Núcleo Celular/genética , DNA Mitocondrial/genética , Evolução Molecular , Funções Verossimilhança , Ratos/genética , Alinhamento de Sequência , Análise de Sequência de DNA , Especificidade da Espécie
9.
Eur J Haematol ; 85(4): 300-8, 2010 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-20561032

RESUMO

OBJECTIVES: Patients with near-tetraploid (karyotype: 81 - 103 chromosomes) acute lymphoblastic leukemia (NT-ALL) constitute about 1% of childhood ALL and data reported on them are limited and controversial. The aim of the study was to enlarge the knowledge on these rarely occurring ALL. METHODS: The members of the European Group for Immunophenotyping of Leukemias (EGIL) searched retrospectively their databases for NT-ALL patients. RESULTS: We collected data of 36 European children from seven European countries with NT-ALL diagnosed since 1992. All patients reached complete remission (CR) after induction chemotherapy. Their blasts were negative for peroxidase and BCR-ABL1. Ten children were diagnosed as T-cell ALL (T-ALL) EGIL categories (T-I n=2, T-II n=2, T-III n=3, T-IV n=3) and four displayed various structural chromosomal abnormalities. Eight of 10 T-ALL remained in 1st CR; one died in CR from sepsis and one is alive in 2nd CR. Median survival was 88 (7-213) months. B-cell precursor (BCP) ALL was diagnosed in 26 children. Thirteen were positive for ETV6-RUNX1 and are alive in 1st CR for 32-147 months. Ten children were ETV6-RUNX1 negative and remained in 1st CR for 16-163 months. One girl with hypodiploid and NT metaphases and ETV6-RUNX1-negative BCP-ALL and one of two boys with NT-BCP-ALL not examined for ETV6-RUNX1 died of infection after stem cell transplantation in 2nd/3rd CR. Secondary myelodysplastic syndrome developed in two patients with NT-BCP-ALL. CONCLUSIONS: Our data demonstrate immunophenotypic, cytogenetic, and molecular heterogeneity of NT-ALL and favorable prognosis of most NT-ALL across different immunophenotypic and/or genetic ALL subtypes.


Assuntos
Leucemia-Linfoma Linfoblástico de Células Precursoras , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Criança , Aberrações Cromossômicas , Subunidade alfa 2 de Fator de Ligação ao Core , Europa (Continente) , Feminino , Proteínas de Fusão bcr-abl/genética , Humanos , Imunofenotipagem , Cariotipagem , Masculino , Proteínas de Fusão Oncogênica/genética , Leucemia-Linfoma Linfoblástico de Células Precursoras/tratamento farmacológico , Leucemia-Linfoma Linfoblástico de Células Precursoras/epidemiologia , Leucemia-Linfoma Linfoblástico de Células Precursoras/genética , Leucemia-Linfoma Linfoblástico de Células Precursoras/imunologia , Leucemia-Linfoma Linfoblástico de Células Precursoras/mortalidade , Prognóstico , Indução de Remissão , Estudos Retrospectivos , Análise de Sobrevida , Resultado do Tratamento
10.
J Pediatr Hematol Oncol ; 30(12): 972-5, 2008 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-19131795

RESUMO

Short-term intensive chemotherapy regimens have substantially improved the prognosis of pediatric patients with Burkitt lymphoma (BL), which now has an excellent overall outcome. However, central nervous system (CNS) involvement at diagnosis remains a poor prognostic factor, and progressive or relapsed disease in the CNS is associated with even worse outcomes. We report 3 boys aged 4, 7, and 12 years treated under the French Société Française d'Oncologie Pédiatrique LMB 89/96 protocols who presented, respectively, with CNS-/bone marrow+ stage-IV BL; CNS+ stage-IV BL; and stage-I BL. Each experienced an isolated CNS relapse, which was treated with CNS-directed salvage chemotherapy. All 3 are alive after 11 years of median follow-up, indicating that this chemotherapy regimen can be curative in pediatric BL with isolated CNS relapse.


Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Linfoma de Burkitt/tratamento farmacológico , Neoplasias do Sistema Nervoso Central/tratamento farmacológico , Recidiva Local de Neoplasia/tratamento farmacológico , Terapia de Salvação , Linfoma de Burkitt/patologia , Neoplasias do Sistema Nervoso Central/patologia , Criança , Pré-Escolar , Ciclofosfamida/uso terapêutico , Citarabina/uso terapêutico , Humanos , Imageamento por Ressonância Magnética , Masculino , Metotrexato/uso terapêutico , Recidiva Local de Neoplasia/patologia , Indução de Remissão , Resultado do Tratamento
11.
World J Stem Cells ; 9(12): 227-234, 2017 Dec 26.
Artigo em Inglês | MEDLINE | ID: mdl-29321824

RESUMO

AIM: To evaluate the importance of the CD34+CD38- cell population when compared to the CD34+CD38+/low and CD34+CD38+/high leukemic cell sub-populations and to determine its correlations with leukemia characteristics and known prognostic factors, as well as with response to therapy and survival. METHODS: Two hundred bone marrow samples were obtained at diagnosis from 200 consecutive patients with newly diagnosed acute myeloid leukemia (AML) were studied between September 2008 and December 2010 at our Institution (Hematology Department, Lyon, France). The CD34/CD38 cell profile was analyzed by multiparameter flowcytometry approach using 8C panels and FACS CANTO and Diva software (BD Bioscience). RESULTS: We analyzed CD34 and CD38 expression in bone marrow samples of 200 AML patients at diagnosis, and investigated the prognostic value of the most immature CD34+CD38- population. Using a cut-off value of 1% of CD34+CD38- from total "bulk leukemic cells" we found that a high (> 1%) level of CD34+CD38- blasts at diagnosis was correlated with advanced age, adverse cytogenetics as well as with a lower rate of complete response after induction and shorter disease-free survival. In a multivariate analysis considering age, leukocytosis, the % of CD34+ blasts cells and the standardized cytogenetic and molecular risk subgroups, a percentage of CD34+CD38- leukemic cells > 1% was an independent predictor of DFS [HR = 2.8 (1.02-7.73), P = 0.04] and OS [HR = 2.65 (1.09-6.43), P = 0.03]. CONCLUSION: Taken together, these results show that a CD34/CD38 "backbone" for leukemic cell analysis by multicolour flowcytometry at diagnosis provides useful prognostic information.

12.
Cancer Genet Cytogenet ; 166(1): 1-11, 2006 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-16616106

RESUMO

Chromosome 21 is frequently rearranged in hematopoietic malignancies. In order to detect new chromosomal aberrations, the Groupe Français de Cytogénétique Hématologique collected a series of 107 patients with various hematologic disorders and acquired structural abnormalities of the long arm of chromosome 21. The abnormalities were subclassified into 10 groups, according to the location of the 21q breakpoint and the type of abnormality. Band 21q22 was implicated in 72 patients (excluding duplications, triplications, and amplifications). The involvement of the RUNX1 gene was confirmed in 10 novel translocations, but the gene partners were not identified. Eleven novel translocations rearranging band 21q22 with bands 1q25, 2p21, 2q37, 3p21, 3p23, 4q31, 6p24 approximately p25, 6p12, 7p15, 16p11, and 18q21 were detected. Rearrangements of band 21q11 and 21q21 were detected in six novel translocations with 5p15, 6p21, 15q21, 16p13, and 20q11 and with 1p33, 3q27, 5p14, 11q11, and 14q11, respectively. Duplications, triplications, amplifications, and isodicentric chromosomes were detected in eight, three, eight, and three patients, respectively. The present study shows both the wide distribution of the breakpoints on the long arm of chromosome 21 in hematopoietic malignancy and the diversity of the chromosomal rearrangements and the hematologic disorders involved. The findings invite further investigation of the 21q abnormalities to detect their associated molecular rearrangements.


Assuntos
Aberrações Cromossômicas , Cromossomos Humanos Par 21/genética , Subunidade alfa 2 de Fator de Ligação ao Core/genética , Doenças Hematológicas/genética , Translocação Genética , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Criança , Pré-Escolar , Comportamento Cooperativo , Feminino , França/epidemiologia , Doenças Hematológicas/epidemiologia , Doenças Hematológicas/patologia , Humanos , Cariotipagem , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos
13.
Leuk Lymphoma ; 44(1): 49-58, 2003 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-12691142

RESUMO

Since the WHO classification of haematological malignancies recommended the description of global entities, we performed a national M7-AML study to correlate morphological, immunological and cytogenetic features, and to find new clinically relevant M7 entities. This study is based on accurate morphological and immunological study to select pure megakaryoblastic proliferations and to eliminate megakaryocytic participation in haemopathies. We collected 53 cases: 23 adults and 30 children. We confirm the wide heterogeneity of adult M7. In adults, the cytogenetic abnormalities are frequently those of secondary leukaemia while a few patients have a previous history and morphological features of dyshaematopoiesis; their outcome is very poor. Among children, besides the well-known Down syndrome M7, we in particular, studied ten t(1;22) M7 and one OTT-MAL transcript positive case with normal karyotype presenting specific features. We were already aware of their younger age, female and tumoral presentation, but we also found a lower percentage of bone marrow blasts, sometimes without any megakaryoblastic bone marrow involvement, but always, with a dysmegakaryocytopoiesis associated with micromegakaryocytes. They are generally good responders to intensive AML chemotherapy with very long disease-free survivals (DFS). Accordingly, OTT-MAL transcript study, in infant M7 with normal karyotype, is recommended and we feel that this entity should be added to the WHO AML classification.


Assuntos
Leucemia Megacarioblástica Aguda/classificação , Leucemia Megacarioblástica Aguda/patologia , Adulto , Fatores Etários , Idoso , Crise Blástica/genética , Crise Blástica/patologia , Células Sanguíneas/patologia , Medula Óssea/patologia , Diferenciação Celular , Tamanho Celular , Pré-Escolar , Análise Citogenética , Feminino , Humanos , Imunofenotipagem , Lactente , Recém-Nascido , Leucemia Megacarioblástica Aguda/complicações , Leucemia Megacarioblástica Aguda/terapia , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos
14.
Viruses ; 6(5): 2214-41, 2014 May 26.
Artigo em Inglês | MEDLINE | ID: mdl-24859344

RESUMO

We reviewed the associations of immunity-related genes with susceptibility of humans and rodents to hantaviruses, and with severity of hantaviral diseases in humans. Several class I and class II HLA haplotypes were linked with severe or benign hantavirus infections, and these haplotypes varied among localities and hantaviruses. The polymorphism of other immunity-related genes including the C4A gene and a high-producing genotype of TNF gene associated with severe PUUV infection. Additional genes that may contribute to disease or to PUUV infection severity include non-carriage of the interleukin-1 receptor antagonist (IL-1RA) allele 2 and IL-1ß (-511) allele 2, polymorphisms of plasminogen activator inhibitor (PAI-1) and platelet GP1a. In addition, immunogenetic studies have been conducted to identify mechanisms that could be linked with the persistence/clearance of hantaviruses in reservoirs. Persistence was associated during experimental infections with an upregulation of anti-inflammatory responses. Using natural rodent population samples, polymorphisms and/or expression levels of several genes have been analyzed. These genes were selected based on the literature of rodent or human/hantavirus interactions (some Mhc class II genes, Tnf promoter, and genes encoding the proteins TLR4, TLR7, Mx2 and ß3 integrin). The comparison of genetic differentiation estimated between bank vole populations sampled over Europe, at neutral and candidate genes, has allowed to evidence signatures of selection for Tnf, Mx2 and the Drb Mhc class II genes. Altogether, these results corroborated the hypothesis of an evolution of tolerance strategies in rodents. We finally discuss the importance of these results from the medical and epidemiological perspectives.


Assuntos
Suscetibilidade a Doenças , Infecções por Hantavirus/imunologia , Infecções por Hantavirus/veterinária , Orthohantavírus/imunologia , Polimorfismo Genético , Doenças dos Roedores/imunologia , Animais , Citocinas/genética , Europa (Continente) , Infecções por Hantavirus/genética , Infecções por Hantavirus/virologia , Humanos , Imunogenética , Receptores Imunológicos/genética , Doenças dos Roedores/genética , Doenças dos Roedores/virologia , Roedores
16.
PLoS One ; 7(11): e48374, 2012.
Artigo em Inglês | MEDLINE | ID: mdl-23144869

RESUMO

Rodentia is the most diverse order among mammals, with more than 2,000 species currently described. Most of the time, species assignation is so difficult based on morphological data solely that identifying rodents at the specific level corresponds to a real challenge. In this study, we compared the applicability of 100 bp mini-barcodes from cytochrome b and cytochrome c oxidase 1 genes to enable rodent species identification. Based on GenBank sequence datasets of 115 rodent species, a 136 bp fragment of cytochrome b was selected as the most discriminatory mini-barcode, and rodent universal primers surrounding this fragment were designed. The efficacy of this new molecular tool was assessed on 946 samples including rodent tissues, feces, museum samples and feces/pellets from predators known to ingest rodents. Utilizing next-generation sequencing technologies able to sequence mixes of DNA, 1,140 amplicons were tagged, multiplexed and sequenced together in one single 454 GS-FLX run. Our method was initially validated on a reference sample set including 265 clearly identified rodent tissues, corresponding to 103 different species. Following validation, 85.6% of 555 rodent samples from Europe, Asia and Africa whose species identity was unknown were able to be identified using the BLASTN program and GenBank reference sequences. In addition, our method proved effective even on degraded rodent DNA samples: 91.8% and 75.9% of samples from feces and museum specimens respectively were correctly identified. Finally, we succeeded in determining the diet of 66.7% of the investigated carnivores from their feces and 81.8% of owls from their pellets. Non-rodent species were also identified, suggesting that our method is sensitive enough to investigate complete predator diets. This study demonstrates how this molecular identification method combined with high-throughput sequencing can open new realms of possibilities in achieving fast, accurate and inexpensive species identification.


Assuntos
Código de Barras de DNA Taxonômico/métodos , Sequenciamento de Nucleotídeos em Larga Escala , Roedores/classificação , Animais , Gatos , Citocromos b/genética , Código de Barras de DNA Taxonômico/normas , Complexo IV da Cadeia de Transporte de Elétrons/genética , Fezes/química , Raposas , Haplótipos , Funções Verossimilhança , Filogenia , Padrões de Referência , Roedores/genética , Pele/química , Manejo de Espécimes , Estrigiformes
17.
PLoS One ; 7(2): e31123, 2012.
Artigo em Inglês | MEDLINE | ID: mdl-22363563

RESUMO

BACKGROUND: The lava mouse, Malpaisomys insularis, was endemic to the Eastern Canary islands and became extinct at the beginning of the 14(th) century when the Europeans reached the archipelago. Studies to determine Malpaisomys' phylogenetic affinities, based on morphological characters, remained inconclusive because morphological changes experienced by this insular rodent make phylogenetic investigations a real challenge. Over 20 years since its first description, Malpaisomys' phylogenetic position remains enigmatic. METHODOLOGY/PRINCIPAL FINDINGS: In this study, we resolved this issue using molecular characters. Mitochondrial and nuclear markers were successfully amplified from subfossils of three lava mouse samples. Molecular phylogenetic reconstructions revealed, without any ambiguity, unsuspected relationships between Malpaisomys and extant mice (genus Mus, Murinae). Moreover, through molecular dating we estimated the origin of the Malpaisomys/mouse clade at 6.9 Ma, corresponding to the maximal age at which the archipelago was colonised by the Malpaisomys ancestor via natural rafting. CONCLUSION/SIGNIFICANCE: This study reconsiders the derived morphological characters of Malpaisomys in light of this unexpected molecular finding. To reconcile molecular and morphological data, we propose to consider Malpaisomys insularis as an insular lineage of mouse.


Assuntos
Extinção Biológica , Camundongos/genética , Paleontologia , Filogenia , Roedores/genética , Animais , Artefatos , Evolução Biológica , DNA/genética , Fósseis , Geografia , Funções Verossimilhança , Dados de Sequência Molecular , Mutação/genética , Reação em Cadeia da Polimerase , Análise de Sequência de DNA , Espanha , Fatores de Tempo , Dente/anatomia & histologia
18.
Mol Phylogenet Evol ; 47(1): 73-83, 2008 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-18328735

RESUMO

Despite numerous studies, questions remain about the evolutionary history of Ursidae and additional independent genetic markers were needed to elucidate these ambiguities. For this purpose, we sequenced ten nuclear genes for all the eight extant bear species. By combining these new sequences with those of four other recently published nuclear markers, we provide new insights into the phylogenetic relationships of the Ursidae family members. The hypothesis that the giant panda was the first species to diverge among ursids is definitively confirmed and the precise branching order within the Ursus genus is clarified for the first time. Moreover, our analyses indicate that the American and the Asiatic black bears do not cluster as sister taxa, as had been previously hypothesised. Sun and sloth bears clearly appear as the most basal ursine species but uncertainties about their exact relationships remain. Since our larger dataset did not enable us to clarify this last question, identifying rare genomic changes in bear genomes could be a promising solution for further studies.


Assuntos
Núcleo Celular/genética , Filogenia , Ursidae/classificação , Ursidae/genética , Animais , Sequência de Bases , DNA/isolamento & purificação , Primers do DNA , Reação em Cadeia da Polimerase
19.
Biol Lett ; 3(1): 57-9; discussion 60-3, 2007 Feb 22.
Artigo em Inglês | MEDLINE | ID: mdl-17443966

RESUMO

Pigmy elephants inhabited the islands from the Mediterranean region during the Pleistocene period but became extinct in the course of the Holocene. Despite striking distinctive anatomical characteristics related to insularity, some similarities with the lineage of extant Asian elephants have suggested that pigmy elephants could be most probably seen as members of the genus Elephas. Poulakakis et al (2006) have recently challenged this view by recovering a short mtDNA sequence from an 800 000 year old fossil of the Cretan pigmy elephant (Elephas creticus). According to the authors of this study, a deep taxonomic revision of Cretan dwarf elephants would be needed, as the sequence exhibits clear affinities with woolly mammoth haplotypes. However, we point here many aspects that seriously weaken the strength of the ancient DNA evidence reported.


Assuntos
DNA Mitocondrial/genética , Elefantes/genética , Fósseis , Animais , Sequência de Bases , Osso e Ossos/química , Primers do DNA , DNA Mitocondrial/análise , Ilhas do Mediterrâneo , Dados de Sequência Molecular , Filogenia , Reação em Cadeia da Polimerase/métodos , Análise de Sequência de DNA/métodos
20.
J Med Virol ; 78(4): 514-6, 2006 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-16482541

RESUMO

Two cases of varicella zoster virus (VZV) meningitis are described in an 18-year-old girl and an 18-year-old boy. They occurred, respectively, 9 days and 9 months after allogeneic bone marrow transplantation. VZV nucleic acid was detected in the cerebrospinal fluid during the 1st week of illness. This recurrence occurred despite valaciclovir prophylaxis and without skin lesions. The two patients received aciclovir intravenously and immunoglobulins infusion. They responded to treatment and their clinical state improved rapidly.


Assuntos
Aciclovir/análogos & derivados , Antivirais/uso terapêutico , Transplante de Medula Óssea/efeitos adversos , Herpesvirus Humano 3/isolamento & purificação , Meningite Viral/virologia , Valina/análogos & derivados , Aciclovir/uso terapêutico , Adolescente , Líquido Cefalorraquidiano/virologia , Quimioprevenção , Varicela/prevenção & controle , Varicela/virologia , Feminino , Herpes Zoster/prevenção & controle , Herpes Zoster/virologia , Humanos , Masculino , Meningite Viral/prevenção & controle , Valaciclovir , Valina/uso terapêutico
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA