ABSTRACT
Abstract Variation in annual rainfall is considered the most important factor influencing population dynamics in dry environments. However, different factors may control population dynamics in different microhabitats. This study recognizes that microhabitat variation may attenuate the influence of climatic seasonality on the population dynamics of herbaceous species in dry forest (Caatinga) areas of Brazil. We evaluated the influence of three microhabitats (flat, rocky and riparian) on the population dynamics of four herbaceous species (Delilia biflora, Commelina obliqua, Phaseolus peduncularis and Euphorbia heterophylla) in a Caatinga (dry forest) fragment at the Experimental Station of the Agronomic Research Institute of Pernambuco in Brazil, over a period of three years. D. biflora, C. obliqua and P. peduncularis were found in all microhabitats, but they were present at low densities in the riparian microhabitat. There was no record of E. heterophylla in the riparian microhabitat. Population size, mortality rates and natality rates varied over time in each microhabitat. This study indicates that different establishment conditions influenced the population size and occurrence of the four species, and it confirms that microhabitat can attenuate the effect of drought stress on mortality during the dry season, but the strength of this attenuator role may vary with time and species.
Resumo A variação anual na precipitação é considerada o fator mais importante que influencia a dinâmica populacional em ambientes secos. No entanto, diferentes fatores podem controlar a dinâmica populacional em diferentes microhabitats. A hipótese deste estudo é que as variações de microhabitats podem atenuar a influência da sazonalidade climática sobre a dinâmica populacional de espécies herbáceas em uma áreas floresta seca (Caatinga) no Brasil. Então, objetivou-se avaliar a influência de três microhabitats (plano, rochoso e ciliar) sobre a dinâmica das populações de quatro espécies herbáceas (Delilia biflora, Commelina obliqua, Phaseolus peduncularis e Euphorbia heterophylla) em um fragmento de Caatinga da Estação Experimental do Instituto de Pesquisas Agronômicas de Pernambuco, no Brasil, durante um período de três anos. D. biflora, C. obliqua e P. peduncularis foram encontrados em todos os microhabitats, mas elas estavam presentes em baixas densidades no microhabitat ciliar. Não houve registro de E. heterophylla no microhabitat ciliar. O tamanho das populações, as taxas de mortalidade e de natalidade variaram ao longo do tempo em cada microhabitat. Este estudo indica que diferentes as condições de estabelecimento influenciaram o tamanho das populações e a ocorrência das quatro espécies e confirma que microhabitat pode atenuar o efeito do estresse hídrico sobre a mortalidade durante a estação seca, mas a força desse papel atenuador pode variar com o tempo e a espécie considerada.
Subject(s)
Magnoliopsida/physiology , Desert Climate , Forests , Brazil , Population Density , Seasons , Species SpecificityABSTRACT
Sentinel lymph node biopsy (SLNB) is an appropriate method for the evaluation of axillary status in cases of early breast cancer. We report our experience in treating cases evaluated using SLNB. We analyzed a total of 1192 cases assessed by means of SLNB from July 1999 to December 2007. SLNB processing was successfully completed in 1154 cases with the use of blue dye or radiolabeled 99mTc-Dextran-500, or both. Of these 1154 patients, 857 were N0(i-) (no regional lymph node metastasis, negative immunohistochemistry, IHC), 96 were N0(i+) (no regional lymph node metastasis histologically, positive IHC, no IHC cluster greater than 0.2 mm) and 201 were N1mi (greater than 0.2 mm, none greater than 2.0 mm). Most of the tumors (70 percent) were invasive ductal carcinomas and tumors were staged as T1 in 770 patients (65 percent). A total of 274 patients underwent SLNB and axillary dissections up to April 2003. The inclusion criteria were tumor size equal to or less than 3 cm in diameter, no clinically palpable axillary lymph nodes, no neoadjuvant therapy. In 19 cases, the SLN could not be identified intraoperatively. A false-negative rate of 11 percent and a negative predictive value of 88.2 percent were obtained for the 255 assessable patients. The overall concordance between SLNB and axillary lymph node status was 92 percent. SLNB sensitivity for nodes was 81 percent and specificity was 100 percent. The higher sensitivity, specificity, accuracy, and lower false-negative rates of SLNB suggest that this method may be an appropriate alternative to total axillary dissection in early breast cancer patients.
Subject(s)
Adult , Aged , Aged, 80 and over , Female , Humans , Middle Aged , Young Adult , Breast Neoplasms/pathology , Sentinel Lymph Node Biopsy , Breast Neoplasms/surgery , Lymph Node Excision , Lymphatic Metastasis/pathology , Neoplasm Staging , Predictive Value of Tests , Retrospective Studies , Sensitivity and Specificity , Young AdultABSTRACT
An anti-carcinoembryonic antigen (CEA) monoclonal antibody (mAb 6D1.1) was evaluated in vitro and in vivo to determine its suitability as a tracer for immunoscintigraphy of colorectal carcinomas. Determination of mAb affinity for CEA showed a constant of association of 0.63 + or - 0.11 x 109 M-1. Binding of technetium-99m (99mTc)-6D1.1, labeled by a direct method, to human cultured lineages was highly specific. Binding to only CEA-positive LS-174T cells resulted in a saturable curve inhibited by pre-incubation with unlabeled mAb. No binding at all was observed for the human lineages MeWo (melanoma) or ZR75-30 (breast carcinoma), neither of them expressing CEA cells. Intravenous injection of 99mTc-6D1.1 into nude mice xenografted with human LS-174T tumors resulted in planar images of excellent quality. Localization of an irrelevant mAb labeled with either 99mTc or iodine-125 was never observed in tumor masses. Biodistribution studies on excised tumoral tissue showed retention of 28.48 percent of the injected dose per gram of LS-174T tumor. The tumor-to-blood ratio was 3.46. The same analysis performed on the other three human xenografted tumors studied demonstrated that only the CEA-producing HT-29 (colorectal adenocarcinoma) retained 99mTc-6D1.1 while the other two (ZR75-30 and MeWo) did not. These data demonstrate that this mAb is an adequate tool for targeting CEA-expressing tumors in experimental models
Subject(s)
Mice , Animals , Antibodies, Monoclonal/analysis , Carcinoembryonic Antigen/immunology , Carcinoma , Colorectal Neoplasms , TechnetiumABSTRACT
Consideracoes gerais sobre a sindrome de Prune Belly. Estudo dos diferentes metodos auxiliares de diagnostico: radiologico, endoscopico e laboratorial. Apresentacao de 4 casos onde nao havia sintomatologia expressiva de sofrimento urinario