Identification of passion fruit (Passiflora edulis) chromosomes using BAC-FISH.

Passiflora edulis, the yellow passion fruit, is the main crop from the Passiflora genus, which comprises 525 species with its diversity center in South America. Genetic maps and a BAC (bacterial artificial chromosome) genomic library are available, but the nine chromosome pairs of similar size and morphology (2n = 18) hamper chromosome identification, leading to different proposed karyotypes. Thus, the aim of this study was to establish chromosome-specific markers for the yellow passion fruit using single-copy and repetitive sequences as probes in fluorescent in situ hybridizations (FISH) to allow chromosome identification and future integration with whole genome data. Thirty-six BAC clones harboring genes and three retrotransposons (Ty1-copy, Ty3-gypsy, and LINE) were selected. Twelve BACs exhibited a dispersed pattern similar to that revealed by retroelements, and one exhibited subtelomeric distribution. Twelve clones showed unique signals in terminal or subterminal regions of the chromosomes, allowing their genes to be anchored to six chromosome pairs that can be identified with single-copy markers. The markers developed herein will provide an important tool for genomic and evolutionary studies in the Passiflora genus.

Temporal change in species and functional plant traits in the moist grassland on the Sete Cidades National Park, Piauí, Brazil.

The present study investigated the dynamic on a short-time scale in the vegetation in moist grassland of the Sete Cidades National Park, Piauí. Herb-subshrub layer samples was carried out in July 2007, 2009 and 2011. Changes in structural, floristic and functional traits in the community were assessed by species richness, diversity and similarity indices between those periods, as well as by hierarchical classification and ordination. Cluster and Principal Component Analyses identified functional groups according to 23 species trait state. To distinguish the contribution of space and time configuration in the community structure, we used the variance partition technique. The functional groups of chamaephytes and therophytes II were associated with wetter sites, while the groups of non-tussock hemicriptophytes I, tussock hemicriptophytes (FG4), and geophytes (FG5) were associated to the drier ones. We found a non-accelerated dynamics, at least on a short-time scale, represented by some descriptors in the community, such as the close similarity between the inventories and ordering of sampling transects in moist grassland. Therefore, besides considering the partition of the temporal niche as a mechanism for the co-existence of species, the heterogeneity of space dictated by environmental filters seems to determine the stability of the this grassland communities over time.

Temporal change in species and functional plant traits in the moist grassland on the Sete Cidades National Park, Piauí, Brazil / Mudança temporal nas espécies e atributos funcionais de plantas em campo limpo úmido de Cerrado no Parque Nacional de Sete Cidades, Piauí, Brasil

The present study investigated the dynamic on a short-time scale in the vegetation in moist grassland of the Sete Cidades National Park, Piauí. Herb-subshrub layer samples was carried out in July 2007, 2009 and 2011. Changes in structural, floristic and functional traits in the community were assessed by species richness, diversity and similarity indices between those periods, as well as by hierarchical classification and ordination. Cluster and Principal Component Analyses identified functional groups according to 23 species trait state. To distinguish the contribution of space and time configuration in the community structure, we used the variance partition technique. The functional groups of chamaephytes and therophytes II were associated with wetter sites, while the groups of non-tussock hemicriptophytes I, tussock hemicriptophytes (FG4), and geophytes (FG5) were associated to the drier ones. We found a non-accelerated dynamics, at least on a short-time scale, represented by some descriptors in the community, such as the close similarity between the inventories and ordering of sampling transects in moist grassland. Therefore, besides considering the partition of the temporal niche as a mechanism for the co-existence of species, the heterogeneity of space dictated by environmental filters seems to determine the stability of the this grassland communities over time.(AU)

O presente estudo investigou a dinâmica em uma curta escala de tempo na vegetação de campo limpo úmido do Parque Nacional Sete Cidades Park, Piauí. Amostragens da camada herbáceo-subarbustiva foram realizadas em julho de 2007, 2009 e 2011. Mudanças estruturais, florísticas e de atributos funcionais da comunidade foram avaliadas por índices de riqueza de espécies, diversidade e similaridade entre esses períodos, bem como por classificação hierárquica e ordenação. Análise de Componentes Principais e de Cluster identificaram grupos funcionais de acordo com 23 atributos das espécies. Para distinguir a contribuição do espaço e do tempo nas análises, usamos técnicas de partição de variância. Os grupos funcionais das caméfitas e terófitas II foram associados com os locais mais úmidos, enquanto os grupos de hemicriptófitas I não entouceiradas, hemicriptófitos entouceiradas e das geófitas (GF5) foram associados aos mais secos. Nós encontramos uma dinâmica não-acelerada, pelo menos em uma escala de curta duração, representada por alguns descritores da comunidade, tais como a similaridade entre os inventários e a ordenação dos transectos no campo limpo úmido. Assim, além de considerar a partição do nicho temporal como um mecanismo para a coexistência de espécies, a heterogeneidade do espaço ditada por filtros ambientais parece determinar a estabilidade destas comunidades campestres ao longo do tempo.(AU)

Ouabain activates NFκB through an NMDA signaling pathway in cultured cerebellar cells.

Na,K-ATPase, an ion pump, has been shown to interact with other proteins in signaling complexes in cardiac myocytes, renal and glial cells, and several other cell types. Our previous in vivo studies indicated that intrahippocampal administration of ouabain (OUA), an inhibitor of Na,K-ATPase, induces NFκB activation, leading to an increase in mRNA levels of target genes of this transcription factor in the rat hippocampus. The present work investigated whether OUA can regulate NF-κB in primary cultured rat cerebellar cells. Cells were treated with different concentrations of OUA (1, 10 or 100 µM) for different periods of time (1, 2 and 4 h). OUA induced a time- and concentration-dependent activation of NFκB (peak of activation: 10 µM, 2 h), involving both p50/p65 and p50/p50 NFκB dimers. OUA (10 µM, 2 h) induced upregulation of tumor necrosis factor α (Tnf-α), interleukin-1ß (Il-1ß), and brain derived neurotrophic factor (Bdnf) mRNA levels. Both NFκB activation and gene expression activation induced by OUA (10 µM) were abolished when cells were pre-treated for 20 min with MK-801 (N-Methyl-D-Aspartate (NMDA) receptor antagonist), manumycin A (farnesyltransferase inhibitor), PP-1(Src-family tyrosine kinase inhibitor) and PD98059 (mitogen-activated protein kinase (MAPK) inhibitor). OUA (10 µM) alone or in the presence of MK-801, PP-1, PD98059 did not cause cell death or DNA fragmentation. These findings suggest that OUA activates NFκB by NMDA-Src-Ras-like protein through MAPK pathways in cultured cerebellar cells. This pathway may mediate an adaptive response in the central nervous system.

Influence of N-methyl-D-aspartate receptors on ouabain activation of nuclear factor-κB in the rat hippocampus.

It has been shown that ouabain (OUA) can activate the Na,K-ATPase complex and mediate intracellular signaling in the central nervous system (CNS). Inflammatory stimulus increases glutamatergic transmission, especially at N-methyl-D-aspartate (NMDA) receptors, which are usually coupled to the activation of nitric oxide synthase (NOS). Nuclear factor-κB (NF-κB) activation modulates the expression of genes involved in development, plasticity, and inflammation. The present work investigated the effects of OUA on NF-κB binding activity in rat hippocampus and the influence of this OUA-Na,K-ATPase signaling cascade in NMDA-mediated NF-κB activation. The findings presented here are the first report indicating that intrahippocampal administration of OUA, in a concentration that did not alter Na,K-ATPase or NOS activity, induced an activation of NF-κB, leading to increases in brain-derived neurotrophic factor (Bdnf), inducible NOS (iNos), tumor necrosis factor-α (Tnf-α), and B-cell leukemia/lymphoma 2 (Bcl2) mRNA levels. This response was not linked to any significant signs of neurodegeneration as showed via Fluoro-Jade B and Nissl stain. Intrahippocampal administration of NMDA induced NF-κB activation and increased NOS and α(2/3) -Na,K-ATPase activities. NMDA treatment further increased OUA-induced NF-κB activation, which was partially blocked by MK-801, an antagonist of NMDA receptor. These results suggest that OUA-induced NF-κB activation is at least in part dependent on Na,K-ATPase modulatory action of NMDA receptor in hippocampus. The interaction of these signaling pathways could be associated with biological mechanisms that may underlie the basal homeostatic state linked to the inflammatory signaling cascade in the brain.

Genetic diversity and a PCR-based method for Xanthomonas axonopodis detection in passion fruit.

Xanthomonas axonopodis pv. passiflorae causes bacterial spot in passion fruit. It attacks the purple and yellow passion fruit as well as the sweet passion fruit. The diversity of 87 isolates of pv. passiflorae collected from across 22 fruit orchards in Brazil was evaluated using molecular profiles and statistical procedures, including an unweighted pair-group method with arithmetical averages-based dendrogram, analysis of molecular variance (AMOVA), and an assigning test that provides information on genetic structure at the population level. Isolates from another eight pathovars were included in the molecular analyses and all were shown to have a distinct repetitive sequence-based polymerase chain reaction profile. Amplified fragment length polymorphism technique revealed considerable diversity among isolates of pv. passiflorae, and AMOVA showed that most of the variance (49.4%) was due to differences between localities. Cluster analysis revealed that most genotypic clusters were homogeneous and that variance was associated primarily with geographic origin. The disease adversely affects fruit production and may kill infected plants. A method for rapid diagnosis of the pathogen, even before the disease symptoms become evident, has value for producers. Here, a set of primers (Xapas) was designed by exploiting a single-nucleotide polymorphism between the sequences of the intergenic 16S-23S rRNA spacer region of the pathovars. Xapas was shown to effectively detect all pv. passiflorae isolates and is recommended for disease diagnosis in passion fruit orchards.

Stress-induced neuroinflammation: mechanisms and new pharmacological targets

Stress is triggered by numerous unexpected environmental, social or pathological stimuli occurring during the life of animals, including humans, which determine changes in all of their systems. Although acute stress is essential for survival, chronic, long-lasting stress can be detrimental. In this review, we present data supporting the hypothesis that stress-related events are characterized by modifications of oxidative/nitrosative pathways in the brain in response to the activation of inflammatory mediators. Recent findings indicate a key role for nitric oxide (NO) and an excess of pro-oxidants in various brain areas as responsible for both neuronal functional impairment and structural damage. Similarly, cyclooxygenase-2 (COX-2), another known source of oxidants, may account for stress-induced brain damage. Interestingly, some of the COX-2-derived mediators, such as the prostaglandin 15d-PGJ2 and its peroxisome proliferator-activated nuclear receptor PPARγ, are activated in the brain in response to stress, constituting a possible endogenous anti-inflammatory mechanism of defense against excessive inflammation. The stress-induced activation of both biochemical pathways depends on the activation of the N-methyl-D-aspartate (NMDA) glutamate receptor and on the activation of the transcription factor nuclear factor kappa B (NFκB). In the case of inducible NO synthase (iNOS), release of the cytokine TNF-α also accounts for its expression. Different pharmacological strategies directed towards different sites in iNOS or COX-2 pathways have been shown to be neuroprotective in stress-induced brain damage: NMDA receptor blockers, inhibitors of TNF-α activation and release, inhibitors of NFκB, specific inhibitors of iNOS and COX-2 activities and PPARγ agonists. This article reviews recent contributions to this area addressing possible new pharmacological targets for the treatment of stress-induced neuropsychiatric disorders.

Species-environment relationship in the herb-subshrub layer of a moist Savanna site, Federal District, Brazil.

The soils are seasonally or permanently saturated in the moist grassland savanna, locally known as Campo Limpo Umido. Soil moisture variation seems to determine spatial distribution of communities. The objective of this study is to analyse the relationship between environmental variables and the patterns of spatial distribution of species in the herbaceous-subshrub layer of an area of moist grassland at the Agua Limpa Farm, Brasília, DF (15 degrees 56' to 15 degrees 59' S and 47 degrees 55' to 47 degrees 58' W Gr.). An area of 400 x 400 m was divided into four sections of 200 x 200 m where four transects were randomly sampled. A line intercept method was adopted for the phytossociological study. Superficial soils samples (0-20 cm) were collected for chemical and textural analyses. Gravimetric soil moisture was measured quarterly during the study-year. A total of 85 species in 67 genera and 24 families were found. The diversity was high, Shannon's index, H', was 2.60 nats.cover(-1). Floristic composition of the transects in soils with a high gravimetric soil moisture and high content of organic matter and sand differed from those transects in soils with a lower gravimetric soil moisture indicating seasonal variation. A Canonical Correspondence Analysis (CCA) showed significant correlations between soil texture and soil moisture features and species distribution. Gravimetric soil moisture, organic matter, clay, silt and sand were significantly correlated to species distribution in the moist grassland determining mosaics in the vegetation.

Species-environment relationship in the herb-subshrub layer of a moist Savanna site, Federal District, Brazil

The soils are seasonally or permanently saturated in the moist grassland savanna, locally known as Campo Limpo Úmido. Soil moisture variation seems to determine spatial distribution of communities. The objective of this study is to analyse the relationship between environmental variables and the patterns of spatial distribution of species in the herbaceous-subshrub layer of an area of moist grassland at the Água Limpa Farm, Brasília, DF (15° 56’ to 15° 59’ S and 47° 55’ to 47° 58’ W Gr.). An area of 400 x 400 m was divided into four sections of 200 x 200 m where four transects were randomly sampled. A line intercept method was adopted for the phytossociological study. Superficial soils samples (0-20 cm) were collected for chemical and textural analyses. Gravimetric soil moisture was measured quarterly during the study-year. A total of 85 species in 67 genera and 24 families were found. The diversity was high, Shannon’s index, H’, was 2.60 nats.cover-1. Floristic composition of the transects in soils with a high gravimetric soil moisture and high content of organic matter and sand differed from those transects in soils with a lower gravimetric soil moisture indicating seasonal variation. A Canonical Correspondence Analysis (CCA) showed significant correlations between soil texture and soil moisture features and species distribution. Gravimetric soil moisture, organic matter, clay, silt and sand were significantly correlated to species distribution in the moist grassland determining mosaics in the vegetation.

O solo é sazonal ou permanentemente saturado nas savanas campestres úmidas, localmente conhecidas como Campo Limpo Úmido. A variação na umidade do solo parece determinar a distribuição espacial desta comunidade. O objetivo deste estudo foi analisar a relação entre as variáveis ambientais e o padrão de distribuição espacial das espécies do estrato herbáceo-subarbustivo em uma área de Campo Limpo Úmido na Fazenda Água Limpa, Brasília, DF (15° 56’ a 15° 59’ S e 47° 55’ a 47° 58’ WGr.). Uma área de 400 x 400 m foi subdividida em quatro porções de 200 x 200 m onde foram sorteadas as linhas de amostragem. No levantamento, fitossociológico adotou-se o método de inventário por interseção na linha. Foram coletadas amostras de solo superficial (0-20 cm) para análise química e textural. A umidade gravimétrica do solo foi obtida quinzenalmente durante o ano de estudo. Foram amostradas 85 espécies incluídas em 67 gêneros e 24 famílias. A diversidade da área segundo o índice de Shannon foi de H’ = 2,60 nats.cobertura-1. A composição florística dos transectos em solos com alta umidade gravimétrica, altos teores de matéria orgânica e areia diferiu da dos transectos em solos com menor umidade gravimétrica e com variação sazonal na umidade. Uma análise de correspondência canônica (CCA) mostrou correlações significativas entre a textura e a umidade do solo e a distribuição das espécies. As variáveis ambientais mais fortemente correlacionadas foram umidade gravimétrica, matéria orgânica, argila, silte e areia, que foram preponderantes na determinação da distribuição das espécies do campo limpo úmido da FAL, determinando a formação de mosaicos na vegetação.

Amyloid beta-peptide activates nuclear factor-kappaB through an N-methyl-D-aspartate signaling pathway in cultured cerebellar cells.

Amyloid beta-peptide (A beta) likely causes functional alterations in neurons well prior to their death. Nuclear factor-kappaB (NF-kappaB), a transcription factor that is known to play important roles in cell survival and apoptosis, has been shown to be modulated by A beta in neurons and glia, but the mechanism is unknown. Because A beta has also been shown to enhance activation of N-methyl-D-aspartate (NMDA) receptors, we investigated the role of NMDA receptor-mediated intracellular signaling pathways in A beta-induced NF-kappaB activation in primary cultured rat cerebellar cells. Cells were treated with different concentrations of A beta1-40 (1 or 2 microM) for different periods (6, 12, or 24 hr). MK-801 (NMDA antagonist), manumycin A and FTase inhibitor 1 (farnesyltransferase inhibitors), PP1 (Src-family tyrosine kinase inhibitor), PD98059 [mitogen-activated protein kinase (MAPK) inhibitor], and LY294002 [phosphatidylinositol 3-kinase (PI3-k) inhibitor] were added 20 min before A beta treatment of the cells. A beta induced a time- and concentration-dependent activation of NF-kappaB (1 microM, 12 hr); both p50/p65 and p50/p50 NF-kappaB dimers were involved. This activation was abolished by MK-801 and attenuated by manumycin A, FTase inhibitor 1, PP1, PD98059, and LY294002. A beta at 1 microM increased the expression of inhibitory protein I kappaB, brain-derived neurotrophic factor, inducible nitric oxide synthase, tumor necrosis factor-alpha, and interleukin-1 beta as shown by RT-PCR assays. Collectively, these findings suggest that A beta activates NF-kappaB by an NMDA-Src-Ras-like protein through MAPK and PI3-k pathways in cultured cerebellar cells. This pathway may mediate an adaptive, neuroprotective response to A beta.

Stress-induced neuroinflammation: mechanisms and new pharmacological targets.

Stress is triggered by numerous unexpected environmental, social or pathological stimuli occurring during the life of animals, including humans, which determine changes in all of their systems. Although acute stress is essential for survival, chronic, long-lasting stress can be detrimental. In this review, we present data supporting the hypothesis that stress-related events are characterized by modifications of oxidative/nitrosative pathways in the brain in response to the activation of inflammatory mediators. Recent findings indicate a key role for nitric oxide (NO) and an excess of pro-oxidants in various brain areas as responsible for both neuronal functional impairment and structural damage. Similarly, cyclooxygenase-2 (COX-2), another known source of oxidants, may account for stress-induced brain damage. Interestingly, some of the COX-2-derived mediators, such as the prostaglandin 15d-PGJ2 and its peroxisome proliferator-activated nuclear receptor PPARgamma, are activated in the brain in response to stress, constituting a possible endogenous anti-inflammatory mechanism of defense against excessive inflammation. The stress-induced activation of both biochemical pathways depends on the activation of the N-methyl-D-aspartate (NMDA) glutamate receptor and on the activation of the transcription factor nuclear factor kappa B (NFkappaB). In the case of inducible NO synthase (iNOS), release of the cytokine TNF-alpha also accounts for its expression. Different pharmacological strategies directed towards different sites in iNOS or COX-2 pathways have been shown to be neuroprotective in stress-induced brain damage: NMDA receptor blockers, inhibitors of TNF-alpha activation and release, inhibitors of NFkappaB, specific inhibitors of iNOS and COX-2 activities and PPARgamma agonists. This article reviews recent contributions to this area addressing possible new pharmacological targets for the treatment of stress-induced neuropsychiatric disorders.

Reproductive phenology of an herbaceous-subshrub layer of a Savannah (Campo Sujo) in the Cerrado Biosphere Reserve I, Brazil.

The objective of this study was to analyse the phenological events in the herbaceous and subshrub layer in relation to rainfall and the dispersion syndromes of the species at a Campo Sujo community in the Agua Limpa Farm (FAL), Brasília-DF. Campo Sujo is a grassland Savannah with a few scattered shrubs and small trees. The climate is Aw by Köppen classification with a mean annual precipitation of 1500 mm. Herbaceus species with three to ten individuals were monitored totalling 519 individuals of 61 species. The individuals were observed quarterly from October 1999 to February 2001. An accidental fire happened in the area two months before the beginning of this study and stimulated flowering and fruiting of the studied species. Flowering at the community level was distributed all over the study period with a concentration of flowering species in the rainy season. The pattern of fruiting was similar to the flowering, with most species maturing their diaspore from the middle to the end of the rainy season. The correlation between anemochoric species producing mature fruits and precipitation was significant and inverse. Anemochoric and autochoric species are dominant at the herbaceous-subshrub layer of the Campo Sujo and they determine the phenological pattern of the community.

Neutrophil function and metabolism in individuals with diabetes mellitus.

Neutrophils act as first-line-of-defense cells and the reduction of their functional activity contributes to the high susceptibility to and severity of infections in diabetes mellitus. Clinical investigations in diabetic patients and experimental studies in diabetic rats and mice clearly demonstrated consistent defects of neutrophil chemotactic, phagocytic and microbicidal activities. Other alterations that have been reported to occur during inflammation in diabetes mellitus include: decreased microvascular responses to inflammatory mediators such as histamine and bradykinin, reduced protein leakage and edema formation, reduced mast cell degranulation, impairment of neutrophil adhesion to the endothelium and migration to the site of inflammation, production of reactive oxygen species and reduced release of cytokines and prostaglandin by neutrophils, increased leukocyte apoptosis, and reduction in lymph node retention capacity. Since neutrophil function requires energy, metabolic changes (i.e., glycolytic and glutaminolytic pathways) may be involved in the reduction of neutrophil function observed in diabetic states. Metabolic routes by which hyperglycemia is linked to neutrophil dysfunction include the advanced protein glycosylation reaction, the polyol pathway, oxygen-free radical formation, the nitric oxide-cyclic guanosine-3'-5'monophosphate pathway, and the glycolytic and glutaminolytic pathways. Lowering of blood glucose levels by insulin treatment of diabetic patients or experimental animals has been reported to have significant correlation with improvement of neutrophil functional activity. Therefore, changes might be primarily linked to a continuing insulin deficiency or to secondary hyperglycemia occurring in the diabetic individual. Accordingly, effective control with insulin treatment is likely to be relevant during infection in diabetic patients.

Neutrophil function and metabolism in individuals with diabetes mellitus

Neutrophils act as first-line-of-defense cells and the reduction of their functional activity contributes to the high susceptibilityto and severity of infections in diabetes mellitus. Clinical investigations in diabetic patients and experimental studies in diabetic rats and mice clearly demonstrated consistent defects of neutrophil chemotactic, phagocytic and microbicidal activities. Other alterations that have been reported to occur during inflammation in diabetes mellitus include: decreased microvascular responses to inflammatory mediators such as histamine and bradykinin, reduced protein leakage and edema formation, reduced mast cell degranulation, impairment of neutrophil adhesionto the endothelium and migration to the site of inflammation, production of reactive oxygen species and reduced release of cytokines and prostaglandin by neutrophils, increased leukocyte apoptosis, and reduction in lymph node retention capacity. Since neutrophil function requires energy, metabolic changes (i.e., glycolytic and glutaminolytic pathways) may be involved in the reduction of neutrophil function observed in diabetic states. Metabolic routes by which hyperglycemia is linked to neutrophil dysfunction include the advanced protein glycosylation reaction, the polyol pathway, oxygen-free radical formation, the nitric oxide-cyclic guanosine-3'-5'monophosphate pathway, and the glycolytic and glutaminolytic pathways. Lowering of blood glucose levels by insulin treatment of diabetic patients or experimental animals has been reported to have significant correlation with improvement of neutrophil functional activity. Therefore, changes might be primarily linked to a continuing insulin deficiency or to secondary hyperglycemia occurring in the diabetic individual. Accordingly, effective control with insulin treatment is likely to be relevant during infection in diabetic patients.

Reproductive phenology of an herbaceous-subshrub layer of a Savannah (Campo Sujo) in the Cerrado Biosphere Reserve I, Brazil

The objective of this study was to analyse the phenological events in the herbaceous and subshrub layer in relation to rainfall and the dispersion syndromes of the species at a Campo Sujo community in the Agua Limpa Farm (FAL), Brasília-DF. Campo Sujo is a grassland Savannah with a few scattered shrubs and small trees. The climate is Aw by Kõppen classification with a mean annual precipitation of 1500 mm. Herbaceus species with three to ten individuals were monitored totalling 519 individuals of 61 species. The individuals were observed quarterly from October 1999 to February 2001. An accidental fire happened in the area two months before the beginning of this study and stimulated flowering and fruiting of the studied species. Flowering at the community level was distributed all over the study period with a concentration of flowering species in the rainy season. The pattern of fruiting was similar to the flowering, with most species maturing their diaspore from the middle to the end of the rainy season. The correlation between anemochoric species producing mature fruits and precipitation was significant and inverse. Anemochoric and autochoric species are dominant at the herbaceous-subshrub layer of the Campo Sujo and they determine the phenological pattern of the community.

O objetivo deste estudo foi analisar os eventos fenológicos na camada herbácea subarbustiva em relação à precipitação e às síndromes de dispersão das espécies em uma comunidade de Campo Sujo na Fazenda Agua Limpa (FAL), Brasília-DF. O Campo Sujo é uma savana predominantemente herbácea com poucos arbustos e pequenas árvores. O clima da região é do tipo Aw, segundo a classificação de Kõppen, com uma precipitação média anual de 1500 mm. Foram selecionadas as espécies que possuíam de 3 a 10 indivíduos, resultando em 61 espécies e 519 indivíduos amostrados. Os indivíduos foram observados quinzenalmente de outubro de 1999 a fevereiro de 2001. O fogo ocorrido na área dois meses antes do início do estudo estimulou a floração e a frutificação das espécies amostradas. A floração na comunidade apresentou-se distribuída por todo o período estudado com concentração de espécies florescendo na estação chuvosa. A produção de frutos foi similar, com a maioria das espécies amadurecendo seus diásporos do meio para o final da estação chuvosa. A correlação entre as espécies anemocóricas produzindo frutos maduros e a precipitação foi significativa e inversa. As espécies anemocóricas e autocóricas são dominantes na camada herbácea subarbustiva de Campo Sujo e determinam o padrão fenológico da comunidade.

Influência das condições hídricas do solo e da temperatura na sobrevivência e alimentação de oncometopia facialis (hemiptera: cicadellidae) em "seedlings" de citros/ / Influence of soil water conditions and temperature on survival and feeding of oncometopia facialis (hemiptera: cicadellidae) on citrus seedlings

RESUMO O comportamento alimentar de cigarrinhas vetoras de Xylella fastidiosa, agente causal da clorose variegada dos citros, pode influenciar sua eficiência de transmissão. Avaliou-se a influência das condições hídricas do solo e da temperatura ambiente na sobrevivência e alimentação do vetor Oncometopia facialis (Hemiptera: Cicadellidae) em "seedlings" de laranjeira doce (Citrus sinensis).O estudo foi realizado em câmara de crescimento, simulando-se condições de temperatura média e de fotofase de verão (24º C e 13h) e de inverno (19º C e 11h) da região Central do Estado de São Paulo. As plantas foram submetidas a dois regimes hídricos: capacidade de campo e déficit hídrico. A sobrevivência de O. facialis foi menor quando mantida em "seedlings" sob déficit hídrico, independentemente das condições de temperatura ("verão" ou "inverno"). A taxa de ingestão de seiva, medida indiretamente pela excreção de "honeydew", foi maior nos tratamentos mantidos em capacidade de campo para as duas condições de temperatura. Comprovou-se, então, que o déficit hídrico do solo reduz a sobrevivência e a taxa de alimentação de O. facialis em "seedlings" de citros. Os resultados sugerem uma menor adequação da planta cítrica às cigarrinhas durante épocas mais secas do ano.

ABSTRACT The feeding behavior of the leafhopper vectors of Xylella fastidiosa, the causal agent of Citrus Variegated Chlorosis, can influence its transmission efficiency. The influence of soil water conditions and environmental temperature on survival and feeding behavior of the leafhopper Oncometopia facialis (Hemiptera: Cicadellidae) was evaluated on sweet orange (Citrus sinensis) seedlings. This study was carried out in a growth chamber adjusted for mean temperature and photophase of summer (24º C and 13h) and winter (19º C and 11h) seasons in the Central Region of Sao Paulo State. The plants were submitted to two soil water treatments: field capacity and water deficit. The survival of the O. facialis was lower on seedlings under water deficit, regardless of the temperature conditions (summer or winter). The sap ingestion rates, which were indirectly measured by the honeydew excretion, were higher on seedlings under field capacity for both temperature conditions. This study shows that soil water deficit reduces leafhopper survival and ingestion rates on citrus seedlings, thus providing evidence that host plant suitability to the vector is affected during the dry season.

Samarium-153 for intravascular irradiation therapy with liquid-filled balloons to prevent restenosis: acute and long-term results in a hypercholesterolemic rabbit restenosis model.

BACKGROUND: It has been shown that irradiation with either beta and gamma sources inhibit neointimal formation. Samarium-153 ((153)Sm) is an isotope with 0.8 MeV, subdivided in three different beta energies and 103 keV of gamma energy. This compound has been tested and used in humans for palliation of pain from bone metastases. The aim of the present study was to evaluate the feasibility and efficacy of brachytherapy with (153)Sm-filled balloon to inhibit neointimal formation in rabbits after balloon overstretch injury. METHODS: Nineteen rabbits underwent balloon injury in their iliac arteries. In 12 animals (control), oversized balloons filled with saline solution were inflated up to 5 atm for a period of 5 min. In 7 rabbits, the same procedure was performed but using balloons filled with (153)Sm. In all cases, both iliac arteries were treated. The prescribed radiation dose was 15 Gy at 1 mm depth. After 30 days, the animals were sacrificed and their arterial segments were analyzed. Radiation exposure at the animal chest to the table and at a distance of 1 m from the table was measured. RESULTS: Histopathologic analysis showed a striking reduction in the amount of neointima in the irradiated arteries compared with control vessels (0.36+/-0.21 vs. 1.07+/-0.56 mm(2), P<.01). The dose delivered to the animal chest was 21.5 mR/h, whereas only 1.9 mR/h was measured at the table and virtually no radiation could be detected at a distance of 1 m from the table. CONCLUSIONS: Brachytherapy with (153)Sm was feasible with minimal personnel exposure radiation and effectively inhibited neointimal formation in this experimental model. These results warrant further experimental and clinical investigations.

Influence of age on nitric oxide modulatory action on Na(+), K(+)-ATPase activity through cyclic GMP pathway in proximal rat trachea.

Age-related changes in the modulatory action of nitric oxide (NO) on cyclic GMP levels and Na(+),K(+)-ATPase activity in the proximal rat trachea were investigated using sodium nitroprusside, 8-bromo-cyclic GMP and okadaic acid. At 24 months, both control activities of Na(+), K(+)-ATPase and Mg(2+)-ATPase were decreased when compared to the segments from 4- and 12-month-old animals. However, cyclic GMP levels were similar among the three ages. Sodium nitroprusside (100 microM) induced stimulation of Na(+),K(+)-ATPase activity in segments from both 4- and 12-month-old animals, but not 24-month-old animals. The effect was specific for Na(+),K(+)-ATPase since Mg(2+)-ATPase activity was unaffected. Sodium nitroprusside induced an increase in nitrates/nitrites and cyclic GMP levels in proximal segments at 4, 12 and 24 months. The 8-bromo-cyclic GMP (100 microM) induced a similar specific stimulation of Na(+),K(+)-ATPase activity in segments from 4- and 12- but not 24-month-old animals. Okadaic acid (1 microM), a phosphatase-1 inhibitor, increased proximal Na(+), K(+)-ATPase but not Mg(2+)-ATPase activity in tissues from 4-, 12- and 24-month-old animals. Our results suggest that aging affects cyclic GMP pathway in proximal rat trachea by an action at the level of the cyclic GMP-dependent protein kinase.

Temporal hemodynamic effects of permissive hypercapnia associated with ideal PEEP in ARDS.

The associated use of permissive hypercapnia (PHY) and high PEEP levels (PEEP(IDEAL)) has been recently indicated as part of a lung-protective-approach (LPA) in acute respiratory distress syndrome (ARDS). However, the net hemodynamic effect produced by this association is not known. We analyzed the temporal hemodynamic effects of this combined strategy in 48 patients (mean age 34 +/- 13 yr) with ARDS, focusing on its immediate (after 1 h), early (first 36 h), and late (2nd-7th d) consequences. Twenty-five patients were submitted to LPA--with the combined use of permissive hypercapnia (PHY), VT < 6 ml/kg, distending pressures above PEEP < 20 cm H2O, and PEEP 2 cm H2O above the lower inflection point on the static inspiratory P-V curve (P(FLEX))- and 23 control patients were submitted to conventional mechanical ventilation. LPA was initiated at once, resulting in an immediate increase in heart rate (p = 0.0002), cardiac output (p = 0.0002), oxygen delivery (DO2l, p = 0.0003), and mixed venous Po2 (p = 0.0006), with a maintained systemic oxygen consumption (p = 0.52). The mean pulmonary arterial pressure markedly increased (mean increment 8.8 mm Hg; p < 0.0001), but the pulmonary vascular resistance did not change (p = 0.32). Cardiac filling pressures increased (p < 0.001) and the systemic vascular resistance fell (p = 0.003). All these alterations were progressively attenuated in the course of the first 36 h, despite persisting hypercapnia. Plasma lactate suffered a progressive decrement along the early period in LPA but not in control patients (p < 0.0001). No hemodynamic consequences of LPA were noticed in the late period and renal function was preserved. A multivariate analysis suggested that these acute hyperdynamic effects were related to respiratory acidosis, with no depressant effects ascribed to high PEEP levels. In contrast, high plateau pressures were associated with cardiovascular depression. Thus, as long as sufficiently low distending pressures are concomitantly applied, the sudden installation of PHY plus PEEP(IDEAL) induces a transitory hyperdynamic state and pulmonary hypertension without harmful consequences to this young ARDS population.