Floristic and structural status of forests in permanent preservation areas of Moju river basin, Amazon region / Comparação florística e estrutural de florestas em áreas de preservação permanente do rio Moju, região Amazônica

Abstract The goal of this study is to analyze the floristic patterns and the structure of disturbed and undisturbed upland forests, in Permanent Preservation Areas (PPAs) along the Moju river, in the Brazilian state of Pará. Trees with a diameter equal to or larger than 10cm at 1.30m from the ground (DBH) ≥10cm were analyzed for the upper stratum. For the middle stratum, individuals with DBH between 4.99 and 9.99cm were sampled. Forty-five families and 221 species were found in disturbed forests, and 43 families and 208 species in undisturbed forests. Floristic similarity was high between strata and between forest types, with values above 50%. Similarity was highest between middle strata. The most species-abundant families in undisturbed forests were Fabaceae, Sapotaceae, Chrysobalanaceae and Myrtaceae; the species with the highest density there were Eschweilera grandiflora, Licania sclerophylla and Zygia cauliflora. In disturbed forests, the dominant families were Fabaceae, Sapotaceae, Lecythidaceae and Melastomataceae. The Shannon-Wiener diversity index was 3.21 for undisturbed forests and 2.85 for disturbed forests. Non-metric multidimensional scaling (MDS) analysis did not group the forests by their floristic composition in both upper and middle strata. Overall, the PPA forests along the Moju river, even if disturbed, did not show major floristic changes but substantially change their structural characteristics.

Resumo Este estudo teve como objetivo analisar os padrões florísticos e a estrutura de florestas ripárias perturbadas e não perturbadas inseridas em Áreas de Preservação Permanente ao longo do rio Moju, Pará. A análise do estrato superior foi realizada em árvores com diâmetro a 1,30 m do solo (DAP) ≥10 cm. No estrato médio, amostrou-se os indivíduos com DAP entre 4,99 e 9,99 cm DAP. Nas florestas perturbadas foram encontradas 45 famílias e 221 espécies e nas florestas não perturbadas, 43 famílias e 208 espécies. A similaridade florística foi elevada entre os estratos e entre os tipos de florestas, alcançando valores maiores de que 50%. A maior semelhança foi encontrada entre os estratos médios. As famílias mais abundantes em espécies nas florestas não perturbadas foram Fabaceae, Sapotaceae, Chrysobalanaceae e Myrtaceae. As espécies com maiores densidades foram Eschweilera grandiflora, Licania sclerophylla e Zygia cauliflora. Nas florestas perturbadas, as famílias dominantes foram Fabaceae, Sapotaceae, Lecythidaceae e Melastomataceae. A diversidade (Shannon) nas florestas não perturbadas foi de 3,21, e nas florestas perturbadas, alcançaram 2,85. A ordenação feita pelo escalonamento multidimensional MDS, não agrupou as florestas por sua composição florística, tanto no estrato superior como no médio. Em geral, as florestas perturbadas das APPs do rio Moju, mesmo se perturbadas, não evidenciam grandes mudanças florísticas, mas apresentam alterações nas suas características estruturais.

Low expression of antigen-presenting and costimulatory molecules by lung cells from tuberculosis patients

Costimulatory and antigen-presenting molecules are essential to the initiation of T cell immunity to mycobacteria. The present study analyzed by immunocytochemistry, using monoclonal antibodies and alkaline phosphatase-anti-alkaline phosphatase method, the frequency of costimulatory (CD86, CD40, CD40L, CD28, and CD152) and antigen-presenting (MHC class II and CD1) molecules expression on human lung cells recovered by sputum induction from tuberculosis (TB) patients (N = 22) and non-TB controls (N = 17). TB cases showed a statistically significant lower percentage of HLA-DR+ cells than control subjects (21.9 ± 4.2 vs 50.0 ± 7.2 percent, P < 0.001), even though similar proportions of TB cases (18/22) and control subjects (16/17, P = 0.36) had HLA-DR-positive-stained cells. In addition, fewer TB cases (10/22) compared to control subjects (16/17) possessed CD86-expressing cells (P = 0.04; OR: 0.05; 95 percentCI = 0.00-0.51), and TB cases expressed a lower percentage of CD86+ cells (P = 0.04). Moreover, TB patients with clinically limited disease (£1 lobe) on chest X-ray exhibited a lower percentage of CD86-bearing cells compared to patients with more extensive lung disease (>1 lobe) (P = 0.02). The lower expression by lung cells from TB patients of HLA-DR and CD86, molecules involved in antigen presentation and activation of T cells, may minimize T cell recognition of Mycobacterium tuberculosis, fostering an immune dysfunctional state and active TB.