Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 17 de 17
Filtrar
1.
Front Oncol ; 13: 1133277, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-36969061

RESUMEN

Background: Endometrial cancer is of increasing concern in several countries, including Brazil, in part because of an ageing population, declines in fertility, and the increasing prevalence of obesity. Although endometrial tumors had lagged behind other cancer types in terms of treatment improvements, molecular characterization of these tumors is paving the way for novel therapies and an expansion of the therapeutic arsenal. We aimed to help medical oncologists who manage patients with recurrent or metastatic endometrial cancer in the Brazilian healthcare setting. Methods: The panel, composed of 20 medical oncologists, convened in November 2021 to address 50 multiple-choice questions on molecular testing and treatment choices. We classified the level of agreement among panelists as (1) consensus (≥75% choosing the same answer), (2) majority vote (50% to <75%), or (3) less than majority vote (<50%). Results: Consensus was present for 25 of the 50 questions, whereas majority vote was present for an additional 23 questions. Key recommendations include molecular testing for every patient with recurrent/metastatic endometrial cancer; choice of first-line treatment according to microsatellite instability and HER2, with the addition of programmed death ligand 1 (PD-L1) and hormone receptors (HRs) for second-line therapy; carboplatin and paclitaxel as the preferred option in first-line treatment of HER2-negative disease, with the addition of trastuzumab in HER2-positive disease; pembrolizumab plus lenvatinib as a key option in second line, regardless of HER2, PD-L1 or HRs; and various recommendations regarding treatment choice for patients with distinct comorbidities. Conclusion: Despite the existing gaps in the current literature, the vast majority of issues addressed by the panel provided a level of agreement sufficient to inform clinical practice in Brazil and in other countries with similar healthcare environments.

2.
Psychiatry Res ; 311: 114477, 2022 05.
Artículo en Inglés | MEDLINE | ID: mdl-35245744

RESUMEN

Brazil is a continental country with a history of massive immigration waves from around the world. Consequently, the Brazilian population is rich in ethnic, cultural, and religious diversity, but suffers from tremendous socioeconomic inequality. Brazil has a documented history of categorizing individuals with culturally specific behaviors as mentally ill, which has led to psychiatric institutionalization for reasons that were more social than clinical. To address this, a "network for psychosocial care" was created in Brazil, that included mental health clinics and community services distributed throughout the country. This generates local support for mental health rehabilitation, integrating psychiatric care, family support and education/work opportunities. These clinics and community services are tailored to provide care for each specific area, and are more attuned to regional culture, values and neighborhood infrastructure. Here we review existing reports about the Brazilian experience, including advances in public policy on mental health, and challenges posed by the large diversity to the psychosocial rehabilitation.  In addition, we show how new digital technologies in general, and computational speech analysis in particular, can contribute to unbiased assessments, resulting in decreased stigma and more effective diagnosis of the mental diseases, with methods that are free of gender, ethnic, or socioeconomic biases.


Asunto(s)
Trastornos Mentales , Servicios de Salud Mental , Enfermos Mentales , Brasil/epidemiología , Humanos , Trastornos Mentales/terapia , Salud Mental , Estigma Social
4.
Future Sci OA ; 7(1): FSO655, 2020 Nov 23.
Artículo en Inglés | MEDLINE | ID: mdl-33437507

RESUMEN

OBJECTIVES: The presence of autoimmune events were recorded in patients receiving immune checkpoint inhibitors. MATERIALS & METHODS: Retrospective study in patients receiving immune checkpoint inhibitors (ICIs) during the period of 2012-2019. RESULTS: A total of 554 patients received ICIs of which 123 developed an immune related adverse event. Twenty one (17%) with toxicity were identified as having a pre-existing autoimmune disease and 88 required treatment with corticosteroids or hormone replacement. Thirty two (26%) out of 123 had to temporarily discontinue ICIs due to autoimmune manifestations. Endocrine and skin manifestations were the most prevalent immune disorders in our cohort. In melanoma better efficacy was seen in patients with immune toxicity. CONCLUSION: Autoimmune diseases appear in patients receiving ICIs in this real world experience. Our results differ from other series on the frequency of autoimmunity. Complete discontinuation of ICIs due to autoimmunity was rare.

5.
Crit Rev Oncol Hematol ; 141: 163-173, 2019 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-31306986

RESUMEN

INTRODUCTION: PARP inhibitors are a new class of drugs that are currently being studied in several malignancies. Olaparib is FDA-approved for advanced breast cancer and advanced ovarian cancer patients. Fatigue and anemia are among the most common cancer and treatment-related symptoms. Therefore, we conducted a meta-analysis of randomized controlled trials (RCT) to characterize the incidence and relative risks (RRs) of fatigue and anemia associated with olaparib. METHODS: PubMed, Cohrane, Embase and abstracts presented at the annual meeting of the American Society of Clinical Oncology (ASCO) were searched for articles published from 2000 to June 2018. The eligible studies were phase II and III RCT of olaparib. Safety profile from each selected study was evaluated for all-grade and high-grade fatigue and anemia adverse events. Summary incidences and the RR, with 95% confidence intervals, of all-grade and high-grade events were calculated using random-effects or fixed-effects model based on the heterogeneity of selected studies. RESULTS: A total of 9 trials were selected, and included 2074 patients with advanced ovarian, gastric, prostate, lung or breast cancer. 908 patients received placebo/control treatments and 1166 received olaparib alone or combination with other active cancer treatments. The RR of all-grade and high fatigue was 1.24 (95% CI, 1.10-1.39) and 1.71 (95% CI, 1.06-2.77), respectively. The RR of all-grade and high-grade anemia was 2.10 (95% CI, 1.48-2.98) and 3.15 (95% CI, 1.73-5.71), respectively. CONCLUSION: Our findings suggest that the olaparib treatment is associated with an increased risk of fatigue and anemia. Since fatigue and anemia are very common treatment related adverse events, and both can impair the quality of life of patients, it is important to identify them early and manage it accordingly in order to optimize the overall treatment.


Asunto(s)
Anemia/etiología , Fatiga/etiología , Neoplasias/tratamiento farmacológico , Ftalazinas/uso terapéutico , Piperazinas/uso terapéutico , Ensayos Clínicos Controlados Aleatorios como Asunto/estadística & datos numéricos , Adulto , Anciano , Anciano de 80 o más Años , Anemia/inducido químicamente , Anemia/epidemiología , Progresión de la Enfermedad , Fatiga/inducido químicamente , Fatiga/epidemiología , Femenino , Humanos , Incidencia , Masculino , Persona de Mediana Edad , Neoplasias/epidemiología , Neoplasias/patología , Calidad de Vida , Riesgo , Factores de Riesgo , Adulto Joven
6.
Breast Cancer Res Treat ; 172(2): 265-272, 2018 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-30099633

RESUMEN

PURPOSE: Breast cancer neoadjuvant chemotherapy (NAC) consists of the administration of cytotoxic and targeted drugs prior to breast surgery, with the objective of reducing the tumor burden to allow breast conservation. NAC also aims to improve long-term treatment outcomes such as disease-free and overall survival. To optimize clinical practice with the best available evidence for breast cancer patients in the setting of neoadjuvant treatment, the Brazilian Society of Breast Surgeons (Sociedade Brasileira de Mastologia-SBM) held a consensus conference to develop this guideline. METHODS: Twenty-two questions addressing relevant breast cancer neoadjuvant treatment were previously formulated. The voting panel comprised 25 specialists from the SBM. A consensus was established if there was 75% agreement. If there was less concordance, after discussion, the consensus was determined by a 51% concordance. RESULTS: The recommendations were based on the best level of scientific evidence and the opinion from breast cancer experts, when no such research data were available. CONCLUSION: This manuscript provides updated guidance according to the views of the SBM's experts for the clinical practice of breast cancer surgeons. This manuscript depicts the summarized recommendations for NAC treatment.


Asunto(s)
Neoplasias de la Mama/tratamiento farmacológico , Neoplasias de la Mama/epidemiología , Neoplasias de la Mama/cirugía , Terapia Neoadyuvante , Brasil/epidemiología , Neoplasias de la Mama/patología , Femenino , Humanos , Mastectomía , Cirujanos
7.
Rio de Janeiro; s.n; 2015. 151 f p.
Tesis en Portugués | LILACS | ID: biblio-905422

RESUMEN

O diagnóstico do transtorno bipolar na infância só foi recentemente reconhecido na psiquiatria infantil, particularmente nos Estados Unidos. Até meados do século vinte não se acreditava que crianças pré-púberes pudessem apresentar sintomatologia compatível com esse diagnóstico, que foi descrito pela primeira vez por Emil Kraepelin no final do século XIX, com o nome de Psicose Maníaco-Depressiva. O termo Transtorno Bipolar foi usado em substituição à psicose maníaco-depressiva na passagem da segunda edição do manual diagnóstico e estatístico norte americano, DSM II, para o DSM III, em 1980. Entre 1994 e 2004 o número de crianças que receberam esse diagnóstico nos Estados Unidos sofreu aumento de 40 vezes, representando a maior bolha diagnóstica desde a primeira edição do DSM. Esse fenômeno resulta da modificação dos critérios diagnósticos pra o transtorno bipolar dos adultos, que são transpostos para a infância modificando seu pilar, que é a alternância entre estados opostos de humor, em um quadro crônico, não mais de depressão e euforia, mas agora de irritabilidade. Isso não aconteceu da mesma forma em outros países, onde as taxas de prevalência são infinitamente menores. No Brasil esses dados são ainda escassos. Nosso objetivo primário com esta pesquisa foi averiguar se o debate acerca do transtorno bipolar na infância é conhecido pelos psiquiatras infantis brasileiros e de que maneira essa discussão se reflete na prática clínica no Brasil. Essa avaliação foi realizada através da aplicação de entrevistas semiestruturadas a 20 psiquiatras infantis, localizados em cinco cidades de grande porte nos principais centros de formação e pesquisa do País. Pode ser constatado que os centros de pesquisa especializados no diagnóstico do transtorno bipolar na infância brasileiros repetem o modelo norte-americano, encontrando taxas muito próximas às encontradas naquele país, enquanto que serviços cujo atendimento não é organizado em função dos diagnósticos (CAPSi, por exemplo) apresentam um quadro bem diferente. O principal fator determinante desse cenário é a transposição da lógica da pesquisa, com suas escalas e instrumentos diagnósticos, para o campo complexo da prática clínica cotidiana, reproduzindo um modelo de avaliação descontextualizada e que desvaloriza a história pessoal da criança. Esta tese contribui para a ampliação do conhecimento sobre como parte importante dos psiquiatras infantis brasileiros lidam com a questão do transtorno bipolar na infância


Asunto(s)
Humanos , Niño , Adolescente , Trastorno Bipolar/diagnóstico , Psiquiatría Infantil/clasificación , Manual Diagnóstico y Estadístico de los Trastornos Mentales , Trastornos del Neurodesarrollo/historia
8.
PLoS Negl Trop Dis ; 6(7): e1722, 2012.
Artículo en Inglés | MEDLINE | ID: mdl-22802979

RESUMEN

Trypanosoma cruzi, the etiological agent of Chagas disease, is a polymorphic species. Evidence suggests that the majority of the T. cruzi populations isolated from afflicted humans, reservoir animals, or vectors are multiclonal. However, the extent and the complexity of multiclonality remain to be established, since aneuploidy cannot be excluded and current conventional cloning methods cannot identify all the representative clones in an infection. To answer this question, we adapted a methodology originally described for analyzing single spermatozoids, to isolate and study single T. cruzi parasites. Accordingly, the cloning apparatus of a Fluorescence-Activated Cell Sorter (FACS) was used to sort single T. cruzi cells directly into 96-wells microplates. Cells were then genotyped using two polymorphic genomic markers and four microsatellite loci. We validated this methodology by testing four T. cruzi populations: one control artificial mixture composed of two monoclonal populations--Silvio X10 cl1 (TcI) and Esmeraldo cl3 (TcII)--and three naturally occurring strains, one isolated from a vector (A316A R7) and two others derived from the first reported human case of Chagas disease. Using this innovative approach, we were able to successfully describe the whole complexity of these natural strains, revealing their multiclonal status. In addition, our results demonstrate that these T. cruzi populations are formed of more clones than originally expected. The method also permitted estimating of the proportion of each subpopulation of the tested strains. The single-cell genotyping approach allowed analysis of intrapopulation diversity at a level of detail not achieved previously, and may thus improve our comprehension of population structure and dynamics of T. cruzi. Finally, this methodology is capable to settle once and for all controversies on the issue of multiclonality.


Asunto(s)
Enfermedad de Chagas/parasitología , Trypanosoma cruzi/clasificación , Trypanosoma cruzi/aislamiento & purificación , Animales , Coinfección/parasitología , Citometría de Flujo , Genotipo , Ratones , Repeticiones de Microsatélite , Polimorfismo Genético , Trypanosoma cruzi/genética
9.
Int J Parasitol ; 38(7): 839-50, 2008 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-18154957

RESUMEN

The investigation of the importance of the genetics of Trypanosoma cruzi in determining the clinical course of Chagas disease will depend on precise characterisation of the parasites present in the tissue lesions. This can be adequately accomplished by the use of hypervariable nuclear markers such as microsatellites. However the unilocal nature of these loci and the scarcity of parasites in chronic lesions make it necessary to use high sensitivity PCR with nested primers, whose design depends on the availability of long flanking regions, a feature not hitherto available for any known T. cruzi microsatellites. Herein, making use of the extensive T. cruzi genome sequence now available and using the Tandem Repeats Finder software, it was possible to identify and characterise seven new microsatellite loci--six composed of trinucleotide (TcTAC15, TcTAT20, TcAAT8, TcATT14, TcGAG10 and TcCAA10) and one composed of tetranucleotide (TcAAAT6) motifs. All except the TcCAA10 locus were physically mapped onto distinct intergenic regions of chromosome III of the CL Brener clone contigs. The TcCAA10 locus was localised within a hypothetical protein gene in the T. cruzi genome. All microsatellites were polymorphic and useful for T. cruzi genetic variability studies. Using the TcTAC15 locus it was possible to separate the strains belonging to the T. cruzi I lineage (DTU I) from those belonging to T. cruzi II (DTU IIb), T. cruzi III (DTU IIc) and a hybrid group (DTU IId, IIe). The long flanking regions of these novel microsatellites allowed construction of nested primers and the use of full nested PCR protocols. This strategy enabled us to detect and differentiate T. cruzi strains directly in clinical specimens including heart, blood, CSF and skin tissues from patients in the acute and chronic phases of Chagas disease.


Asunto(s)
Enfermedad de Chagas/genética , Genes Protozoarios , Repeticiones de Microsatélite , Trypanosoma cruzi/genética , Animales , Enfermedad de Chagas/parasitología , Mapeo Cromosómico , Enfermedad Crónica , Cartilla de ADN/genética , Electroforesis en Gel de Poliacrilamida , Femenino , Frecuencia de los Genes , Corazón/parasitología , Humanos , Masculino , Ratones , Ratones Endogámicos BALB C , Parasitemia , Reacción en Cadena de la Polimerasa , Polimorfismo Genético , Embarazo , Recto/parasitología , Alineación de Secuencia , Piel/parasitología , Trypanosoma cruzi/aislamiento & purificación
10.
Arq Neuropsiquiatr ; 65(4A): 960-4, 2007 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-18094854

RESUMEN

OBJECTIVE AND METHOD: To review the clinical and neuropathological findings as well as the type of therapy and outcome in 20 infants under 3 years-old with central nervous system (CNS) tumor. They were treated at the Department of Neurology, "Hospital das Clínicas" University of São Paulo Medical School, from January 1997 to May 2001. RESULTS: Astrocytoma was the most common histological type (n=7), followed by ependymoma (n=3), medulloblastoma (n=2), craniopharyngioma (n=2) and desmoplastic ganglioglioma (n=2). The location of the tumor was predominantly supratentorial. Mean follow-up time was 20.2 months with recurrence in 7 cases. For each type of tumor we have emphasized the treatment currently recommended. CONCLUSION: Although follow-up time is not sufficient for analyzing survival, a trend of improvement in prognosis was noted, compared to another series of cases from our Institution that had been evaluated before 1990.


Asunto(s)
Neoplasias Encefálicas , Neoplasias Encefálicas/complicaciones , Neoplasias Encefálicas/diagnóstico , Neoplasias Encefálicas/cirugía , Preescolar , Femenino , Estudios de Seguimiento , Humanos , Lactante , Imagen por Resonancia Magnética , Masculino , Recurrencia Local de Neoplasia , Estudios Retrospectivos , Resultado del Tratamiento
11.
Arq. neuropsiquiatr ; 65(4a): 960-964, dez. 2007. tab
Artículo en Inglés | LILACS | ID: lil-470122

RESUMEN

OBJECTIVE AND METHOD: To review the clinical and neuropathological findings as well as the type of therapy and outcome in 20 infants under 3 years-old with central nervous system (CNS) tumor. They were treated at the Department of Neurology, "Hospital das Clínicas" University of São Paulo Medical School, from January 1997 to May 2001. RESULTS: Astrocytoma was the most common histological type (n=7), followed by ependymoma (n=3), medulloblastoma (n=2), craniopharyngioma (n=2) and desmoplastic ganglioglioma (n=2). The location of the tumor was predominantly supratentorial. Mean follow-up time was 20.2 months with recurrence in 7 cases. For each type of tumor we have emphasized the treatment currently recommended. CONCLUSION: Although follow-up time is not sufficient for analyzing survival, a trend of improvement in prognosis was noted, compared to another series of cases from our Institution that had been evaluated before 1990.


OBJETIVO E MÉTODO: Avaliar os aspectos clínicos e histopatológicos, o tipo de tratamento e a evolução de 20 crianças menores de três anos de idade, com o diagnóstico de tumor de sistema nervoso central, que foram tratadas em nossa Instituição no período de janeiro de 1997 a maio de 2001. RESULTADOS: O astrocitoma foi o tumor mais comum (n=7), seguido pelo ependimoma (n=3), meduloblastoma (n=2), craniofaringioma (n=2) e ganglioglioma desmoplásico infantil (n=2). A localização do tumor foi predominantemente supratentorial. A média de seguimento foi 20,2 meses e houve recidiva em sete casos. Para cada tipo de tumor enfatizamos o tipo de tratamento recomendado na atualidade. CONCLUSÃO: Embora o tempo de seguimento não seja suficiente, ainda, para analisar a sobrevida, foi notada nítida tendência a melhor prognóstico em comparação com a casuística proviniente de nossa Instituição que analisou casos abordados antes da década de 90.


Asunto(s)
Preescolar , Femenino , Humanos , Lactante , Masculino , Neoplasias Encefálicas , Neoplasias Encefálicas/complicaciones , Neoplasias Encefálicas/diagnóstico , Neoplasias Encefálicas/cirugía , Estudios de Seguimiento , Imagen por Resonancia Magnética , Recurrencia Local de Neoplasia , Estudios Retrospectivos , Resultado del Tratamiento
12.
Hum Hered ; 62(4): 190-5, 2006.
Artículo en Inglés | MEDLINE | ID: mdl-17106202

RESUMEN

The population of Brazil, formed by extensive admixture between Amerindians, Europeans and Africans, is one of the most variable in the world. We have recently published a study that used ancestry-informative markers to conclude that in Brazil, at an individual level, color, as determined by physical evaluation, was a poor predictor of genomic ancestry, estimated by molecular markers. To corroborate these findings we undertook the present investigation based on data from 12 commercially available forensic microsatellites that were utilized to estimate the personal genomic origin for each of 752 individuals from the city of São Paulo, belonging to different Brazilian color categories (275 Whites, 192 Intermediates and 285 Blacks). The genotypes permitted the calculation of a personal likelihood-ratio estimator of African or European ancestry. Although the 12 marker set proved capable of discriminating between European and African individuals, we observed very significant overlaps among the three color categories of Brazilians. This was confirmed quantitatively using a Bayesian analysis of population structure that did not demonstrate significant genetic differentiation between the three color groups. These results corroborate and validate our previous conclusions using ancestry-informative markers that in Brazil at the individual level there is significant dissociation of color and genomic ancestry.


Asunto(s)
Repeticiones de Microsatélite , Pigmentación de la Piel/genética , Población Negra , Brasil , Genética de Población/métodos , Humanos , Población Blanca/genética
13.
Ann Hum Genet ; 70(Pt 5): 658-65, 2006 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-16907710

RESUMEN

In a landmark study Rosenberg et al. (2002) analyzed human genome diversity with 377 microsatellites in the HGDP-CEPH Genome Diversity Panel and reported that the populations were structured into five geographical regions: America, Sub-Saharan Africa, East Asia, Oceania and a cluster composed of Europe, the Middle East and Central Asia. They also observed that the within-population component accounted for 93-95%, and that the among-regions portion was only 3.6%, of the total genetic variance. We have also studied the HGDP-CEPH Diversity Panel (1,064 individuals from 52 populations) with a set of 40 biallelic slow-evolving short insertion-deletion polymorphisms (indels). We confirmed the partition of worldwide diversity into five genetic clusters that correspond to major geographic regions. Using the indels we have also disclosed an among-regions component of genetic variance considerably larger (12.1%) than had been estimated using microsatellites. Our study demonstrates that a set of 40 well-chosen biallelic markers is sufficient for the characterization of human population structure at the global level.


Asunto(s)
Elementos Transponibles de ADN , Eliminación de Gen , Genética de Población , Genoma Humano , Polimorfismo Genético , Variación Genética , Geografía , Humanos
14.
PLoS Pathog ; 2(3): e24, 2006 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-16609729

RESUMEN

Acquisition of detailed knowledge of the structure and evolution of Trypanosoma cruzi populations is essential for control of Chagas disease. We profiled 75 strains of the parasite with five nuclear microsatellite loci, 24Salpha RNA genes, and sequence polymorphisms in the mitochondrial cytochrome oxidase subunit II gene. We also used sequences available in GenBank for the mitochondrial genes cytochrome B and NADH dehydrogenase subunit 1. A multidimensional scaling plot (MDS) based in microsatellite data divided the parasites into four clusters corresponding to T. cruzi I (MDS-cluster A), T. cruzi II (MDS-cluster C), a third group of T. cruzi strains (MDS-cluster B), and hybrid strains (MDS-cluster BH). The first two clusters matched respectively mitochondrial clades A and C, while the other two belonged to mitochondrial clade B. The 24Salpha rDNA and microsatellite profiling data were combined into multilocus genotypes that were analyzed by the haplotype reconstruction program PHASE. We identified 141 haplotypes that were clearly distributed into three haplogroups (X, Y, and Z). All strains belonging to T. cruzi I (MDS-cluster A) were Z/Z, the T. cruzi II strains (MDS-cluster C) were Y/Y, and those belonging to MDS-cluster B (unclassified T. cruzi) had X/X haplogroup genotypes. The strains grouped in the MDS-cluster BH were X/Y, confirming their hybrid character. Based on these results we propose the following minimal scenario for T. cruzi evolution. In a distant past there were at a minimum three ancestral lineages that we may call, respectively, T. cruzi I, T. cruzi II, and T. cruzi III. At least two hybridization events involving T. cruzi II and T. cruzi III produced evolutionarily viable progeny. In both events, the mitochondrial recipient (as identified by the mitochondrial clade of the hybrid strains) was T. cruzi II and the mitochondrial donor was T. cruzi III.


Asunto(s)
Evolución Biológica , Genoma de Protozoos , Factores Sexuales , Trypanosoma cruzi/genética , Animales , Secuencia de Bases , Genes Mitocondriales , Marcadores Genéticos , Genética de Población , Genotipo , Repeticiones de Microsatélite , Datos de Secuencia Molecular , Filogenia
15.
Ann Hum Genet ; 70(5): 658-665, 2006 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-29488221

RESUMEN

In a landmark study Rosenberg et al. (2002) analyzed human genome diversity with 377 microsatellites in the HGDP-CEPH Genome Diversity Panel and reported that the populations were structured into five geographical regions: America, Sub-Saharan Africa, East Asia, Oceania and a cluster composed of Europe, the Middle East and Central Asia. They also observed that the within-population component accounted for 93-95%, and that the among-regions portion was only 3.6%, of the total genetic variance. We have also studied the HGDP-CEPH Diversity Panel (1064 individuals from 52 populations) with a set of 40 biallelic slow-evolving short insertion-deletion polymorphisms (indels). We confirmed the partition of worldwide diversity into five genetic clusters that correspond to major geographic regions. Using the indels we have also disclosed an among-regions component of genetic variance considerably larger (12.1%) than had been estimated using microsatellites. Our study demonstrates that a set of 40 well-chosen biallelic markers is sufficient for the characterization of human population structure at the global level.

16.
Mem. Inst. Oswaldo Cruz ; 96(3): 407-413, Apr. 2001. ilus, tab
Artículo en Inglés | LILACS | ID: lil-282855

RESUMEN

Through microsatellite analysis of 53 monoclonal populations of Trypanosoma cruzi, we found a remarkable degree of genetic polymorphism with no single multilocus genotype being observed more than once. The microsatellite profile proved to be stable during 70 generations of the CL Brener clone in culture. The microsatellite profiling presented also high diagnostic sensitivity since DNA amplifications could be achieved with less than 100 fg DNA, corresponding to half parasite total DNA content. Based on these technical attributes the microsatellite assay turns out to be an important tool for direct typing T. cruzi in biological samples. By using this approach we were able to type T. cruzi in feces of artificially infected bugs and in single cells sorted by FACS. The microsatellites have shown to be excellent markers for T. cruzi phylogenetic reconstruction. We used maximum parsimony based on the minimum number of mutational steps to build an unrooted Wagner network, which confirms previous conclusions based on the analysis of the D7 domain of the LSU rDNA gene that T. cruzi is composed by two major groups. We also obtained evidence that strains belonging to rRNA group 2 are subdivided into two genetically distant clusters, and that one of these clusters is more related to rRNA group 1/2. These results suggest different origins for these strains


Asunto(s)
Animales , Humanos , Repeticiones de Microsatélite , Trypanosoma cruzi/genética , ADN Protozoario/análisis , ADN Protozoario/genética , Genotipo , Técnicas de Amplificación de Ácido Nucleico , Filogenia , Reacción en Cadena de la Polimerasa , Polimorfismo Genético/genética , Sensibilidad y Especificidad
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA
...