Navegando por Assunto "Diagnóstico molecular"

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Acesso aberto (Open Access)
Nested-PCR do gene que codifica o antígeno b aplicada ao diagnóstico da tuberculose pulmonar
(2007-04) LIMA, Karla Valéria Batista; LOPES, Maria Luíza; LOUREIRO, Edvaldo Carlos Brito; COSTA, Maurimélia Mesquita da; CARDOSO, Ninarosa Calzavara; LIMA, George Leandro Ferreira; SOUSA, Maísa Silva de
The polymerase chain reaction used for amplifying an internal sequence of a previously amplified fragment (nested-PCR) was investigated as a complementary alternative for searching for alcohol-acid resistant bacilli and Mycobacterium tuberculosis cultures in Lowenstein-Jensen medium. 144 sputum samples were investigated from patients with suspected tuberculosis that were sent to the Tuberculosis Laboratory of the Evandro Chagas Institute in Belém, between June 2002 and December 2003. From the 144 samples, 121 were characterized as tuberculosis: 119 were positive in cultures, 95 under bacilloscopy and 128 using nested-PCR. The sensibility of the nested-PCR was 96% (116/121), while the specificity was 48% (11/23). Nested-PCR may be a complementary tool for diagnosing tuberculosis, since it presents sensitivity equivalent to that of cultures. However, further evaluations are needed with the aim of minimizing the number of false-positive results.
Acesso aberto (Open Access)
Variação morfológica, vocal e genética na espécie politípica Lepidocolaptes albolineatus (Aves – Dendrocolaptidae)
(Universidade Federal do Pará, 2008) RODRIGUES, Elinete Batista; ALEIXO, Alexandre Luis Padovan; http://lattes.cnpq.br/3661799396744570
Lepidocolaptes albolineatus (Aves: Dendrocolaptidae) is a polytypic biological species including the following taxa: L. a. albolineatus occurring in the Guiana Area of Endemism (hereafter AE), L. a. duidae (Imeri AE), L. a. fuscicapillus and L. a. madeirae (both in the Rondônia AE), and L. a. layardi (Tapajós, Xingu, and Belém AEs). The main goals of the present study were: (1) review the validity and diagnoses of the taxa grouped under L. albolineatus based on a combination of morphological, vocal, and molecular characters, and (2) re-evaluate inter-specific limits between among those taxa. A total of 150 specimens deposited in Brazilian and North American collections were measured. In the molecular analysis a total of 940 bp of the mitochondrial gene ND2 belonging to 35 individuals representing all taxa of L. albolineatus was sequenced. PAUP 4.0 b 10 and MrBayes 3.1 were used to generate phylogenetic trees under parsimony, maximum likelihood, and Bayesian approaches. Morphological and molecular data strongly supported the existence of five natural populations (clades) within L. albolineatus: clade 1 (grouping populations from the Rondônia AE), clade 2 (including populations of the Belém, Xingu, and Tapajós AEs), clade 3 (including specimens from the Inambari AE), clade 4 (grouping specimens from the Imeri AE), and clade 5 (including specimens of the Guiana AE). All clades corresponded to already named taxa, except clade 3, which has no valid name yet since the name fuscicapillus is in fact applicable to clade 1, and therefore must be considered the senior synonymous of madeirae. The main genetic and morphological separation in L. albolineatus occurs between the nominate taxon (clade 5) and all remaining taxa and clades, although each clade recognized in the analysis can be regarded as a separate species under the General Lineage Species Concept, since they are all mutually diagnosed based on a combination of morphological, vocal, and genetic characters.