Mature circulating polymorphonuclear cells (PMN) have the shortest half- life among leukocytes and undergo rapid programmed cell death in vitro. In this study, we have examined the possibility that inflammatory signals (cytokines and bacterial products) can regulate PMN survival. PMN in culture were found to rapidly die, with percentages of survival at 24, 48, 72, and 96 hours of 97.3% +/- 1.9%, 36.8% +/- 5.3%, 14.5% +/- 3.1%, and 4.2% +/- 2.9%, respectively (mean +/- SE of 20 different donors). PMN incubated with interleukin-1 beta (IL-1 beta), tumor necrosis factor, granulocyte-macrophage colony-stimulating factor (CSF), granulocyte-CSF, and interferon-gamma (IFN-gamma), but not with prototypic chemoattractants (fMLP, recombinant C5a, and IL-8), showed a marked increase in survival, with values ranging at 72 hours of incubation from 89.5% +/- 5.8% for IL-1 beta to 47.6% +/- 6.4% for IFN- gamma. The calculated half-life was 35 hours for untreated and 115 hours for IL-1-treated PMN. PMN activated with lipopolysaccharide (LPS) or inactivated streptococci also showed a longer survival compared with untreated cells (94.4% +/- 3.2% and 95.5% +/- 2.4%, respectively, at 72 hours). PMN surviving in response to LPS or IL-1 beta retained the capacity to produce superoxide anion when treated with phorbol esters or fMLP. All inducers of PMN survival protect these cells from programmed cell death because they reduced cells with morphologic features of apoptosis and the fragmentation of DNA in multiples of 180 bp. Thus, certain cytokines and bacterial products can prolong PMN survival by interfering with the physiologic process of apoptosis. Prolongation of survival may be important for the regulation of host resistance and inflammation, and may represent a crucial permissive step for certain cytokines and microbial products that activate gene expression and function in PMN.

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Euterpe edulis (Martius) is a single‐stemmed, abundant Neotropical palm of the Brazilian Atlantic Forest (Mata Atlântica). The species produces the heart of palm, locally called palmito, which is an important source of income for forest owners. Because of its high market value, its short‐term demands of the forest environment, and its important interactions with animal species, this palm is suitable for sustainable management and conservation purposes. In this paper, we present the results from a 15‐year investigation of this species, synthesizing results on its demography, seed dispersion, reproductive biology, genetics, and economics. We have linked these results in a proposal for the species' sustainable management and conservation.

-(Reproductive phenology and seed production of Araucaria angustifolia (Bert.) O. Kuntze). The knowledge about the reproductive phenology of Araucaria angustifolia has applications to the seed harvest for "ex situ" conservation, for commercial use of the seeds and to understand the dynamic and regeneration of its natural populations. The reproductive phenology and seed production of A. angustifolia were evaluated for a natural population occurring at Parque Estadual Campos de Jordão, São Paulo State, Brazil. The present study investigates: (i) how is the reproductive cycle and the phenological pattern of araucaria? (ii) how is the potential of seed production and its variability? Sixty adult plants (30 males and 30 females) were marked for phenological observations. Seed production was estimated based on the number of female plants in a 10 ha area, number of cones per plant, number of seeds per cone and seed weight. The reproductive cycle of A. angustifolia extended for 20 to 24 months, from the observation of the first cone to seed fall. The pollination occurred between September and October and seed maturation and seed fall from March to June. Seed production was significantly different between years (117 kg.ha -1 in 2001 e 160 kg.ha -1 in 2002). The duration of ripe seed offer was also different between years. The variation observed in the amount and availability of seeds suggests that the observation of reproductive phenology and estimation of seed production are important to guide strategies for conservation and management of this resource.Key words -Araucaria angustifolia, Araucaria forest, reproductive phenology, seed production RESUMO -(Fenologia reprodutiva e produção de sementes em Araucaria angustifolia (Bert.) O. Kuntze). O estudo da fenologia reprodutiva de A. angustifolia tem aplicação na coleta de sementes destinadas à conservação de germoplasma, à obtenção de sementes para fins comerciais e ao entendimento da dinâmica de regeneração das populações naturais. Este trabalho teve como objetivo investigar a fenologia reprodutiva em uma população natural de A. angustifolia localizada no Parque Estadual Campos do Jordão, SP, procurando entender: (i) Qual é o seu ciclo reprodutivo e o comportamento fenológico? (ii) Como varia e qual o potencial de produção de sementes desta espécie? Para o acompanhamento da fenologia reprodutiva foram marcados 60 indivíduos (30 masculinos e 30 femininos), observados de novembro de1999 a agosto de 2002. A produção de sementes foi estimada com base na contagem do número de plantas femininas, número de estróbilos por planta, número de sementes por estróbilo e peso de sementes. O ciclo reprodutivo da A. angustifolia foi de 20 a 24 meses, do aparecimento dos estróbilos até a queda das sementes. A polinização ocorreu entre setembro e outubro e a maturação e queda das sementes de março a junho. A produção de sementes mostrou diferença significativa entre os anos (117 kg.ha -1 em 2001 e 160 kg.ha -1 em 2002) e a duração da oferta foi distinta entre anos. As variações na...