Efeito fitotóxico do óleo volátil de Cleome guianensis Aubl. sobre o crescimento inicial de Senna occidentalis L. / Phytotoxic effect of Cleome guianensis Aubl. on the initial growth of Senna occidentalis L.

RESUMO Aleloquímicos são substâncias liberadas por certas espécies vegetais no ambiente que influenciam a germinação e o desenvolvimento de outras plantas. O objetivo desse estudo foi avaliar o potencial fitotóxico de Cleome guianensis Aubl., bem como determinar o grau de estresse oxidativo causado em Senna occidentalis L. Para isso, o óleo das folhas de C. guianensis, nas concentrações 0,5 µg/mL, 1,0 µg/mL, 2,5 µg/mL e 5,0 µg/mL, em solução de 5 ml foi testado em bioensaios de germinação e de crescimento da raiz primária e do hipocótilo de S. occidentalis. Os indivíduos de S. occidentalis foram macerados, homogeneizados e submetidos a ensaios de quantificação da catalase, peroxidase, SOD e de peroxidação lipídica. Os resultados indicam que todas as concentrações do óleo volátil causaram um efeito negativo sobre a germinação e crescimento de S. occidentalis. Na concentração 5,0 µg/mL, houve 56% de inibição da germinação e 83% de inibição de crescimento do hipocótilo. Ainda, o óleo aumentou a atividade das enzimas induzidas pelo estresse oxidativo catalase, peroxidase e superóxido dismutase (SOD). Quanto à peroxidação lipídica, o óleo nas concentrações 1,0 µg/mL, 2,5 µg/mL e 5,0 µg/mL aumentou a produção de malondialdeído. Sendo assim, conclui-se que C. guianensis apresenta aleloquímicos que influenciam na germinação e no crescimento de S. occidentalis, além de aumentar a atividade das enzimas catalase, peroxidase, SOD e a produção de malondialdeído em S. occidentalis. Dessa forma, sugere-se a realização de estudos sobre o perfil químico do óleo a fim de descobrir as substâncias responsáveis por tais resultados e consolidar o potencial fitotóxico de C. guianensis.

ABSTRACT Allelochemicals inhibit the germination and growth of other plants. The purpose of this study was to assess the phytotoxic potential of Cleome guianensis Aubl., as well as determine the degree of oxidative stress caused in Senna occidentalis L. For this purpose, oil from the leaves of C. guianensis in concentrations of 0.5 µg/mL, 1.0 µg/mL, 2.5 µg/mL, and 5.0 µg/mL were tested in bioassays on the germination and growth of S. occidentalis. Specimens of S. occidentalis were macerated, homogenized, and submitted to catalase, peroxidase, superoxide dismutase (SOD), and lipid peroxidation quantification tests. Results showed that all concentrations of the volatile oil had a negative effect on S. occidentalis germination and growth. In the 5.0 µg/mL concentration, the oil inhibited 56% of germination and 83% of hypocotyl growth. In addition, the oil increased the activity of the enzymes induced by oxidative stress: catalase, peroxidase, and superoxide dismutase SOD. For lipid peroxidation, the oil in the 1.0 µg/mL, 2.5 µg/mL and 5.0 µg/mL concentrations increased the production of malondialdehyde. In addition, C. guianensis presents allelochemicals that influence the germination and growth of S. occidentalis, also enhancing activity of the catalase, peroxidase, and SOD enxymes, as well as malondialdehyde production in S. occidentallis. Hence, further studies of the chemical profile of this oil should be performed in order to discover which allelochemicals are responsible for these results and consolidate the phytotoxic potential of C. guianensis.

Physical characteristics of the eggs of red-legged partridge (Alectoris rufa) reared in captivity / Características físicas dos ovos da perdiz vermelha (Alectoris rufa) criada em cativeiro

O objetivo do presente estudo foi avaliar os efeitos da idade das fêmeas (um, dois e três anos) e do mês de postura (março, abril e maio) sobre as características físicas dos ovos da perdiz vermelha (Alectoris rufa) criada em cativeiro. O peso (W), o comprimento máximo (L) e a largura máxima (B) de 2878 ovos foram determinados diretamente, enquanto o índice de forma (B/L), o volume (V) e a superfície (S) foram calculados com base nos parâmetros determinados diretamente. A análise mostrou diferenças significativas (P<0,01) no peso dos ovos entre as diferentes idades e entre meses de postura, com menor peso nas fêmeas mais jovens. Observaram-se diferenças significativas (P<0,01) no comprimento do ovo entre as classes de idade, mas não entre os meses de postura (P>0,05). Observaram-se diferenças significativas (P<0,01) na largura máxima e no índice de forma do ovo entre as diferentes classes de idades, com valores mais elevados nas fêmeas mais velhas e no período de postura mais tardio. O volume dos ovos estimados por meio de V1= 0,51LB2e V2=0,913W foi afetado significativamente (P<0,01) pela idade e pelo mês de postura, bem como as áreas, S1=4.835W0,662, S2=4,951V10,666e S3=4,951V20,666, as quais apresentaram os mesmos efeitos.

Structure of the phytoplankton community in the Cachoeira Dourada reservoir (GO/MG), Brazil / Estrutura da comunidade fitoplanctônica do reservatório de Cachoeira Dourada, GO/MG, Brasil

The limnological features and the phytoplankton community of the Cachoeira Dourada reservoir were analyzed in December 2006, May 2007 and November 2007. Temporal changes in the taxonomic composition, density, diversity and dominance of species were analyzed in relation to climatic factors and the physical and chemical characteristics of the water. A positive correlation was found between some of the physical and chemical variables and the phytoplankton community. According to the CCA, variables such as the extent of the euphotic zone, temperature, pH, nitrogen and phosphorus concentrations directly affected the phytoplankton dynamics. Organisms belonging to the class Cyanophyceae were the most representative in all the sampling periods, comprising the functional groups K, S1, M and H. Hydrodynamics and seasonal fluctuations of environmental factors were the driving forces determining the composition and abundance of the algal assemblages. Despite the prevalence of Cyanobacteria, the reservoir is still oligotrophic. The absence of blooms and the relatively low population abundances indicated that the quality of the reservoir's water still lies within the limits required for its multiples uses.

As características limnológicas e a comunidade fitoplanctônica do reservatório de Cachoeira Dourada foram analisadas nos meses de dezembro de 2006, maio de 2007 e novembro de 2007. As flutuações temporais na composição taxonômica, densidade, diversidade e dominância de espécies foram analisadas em relação aos fatores climáticos e às variáveis físicas e químicas da água. Uma correlação positiva foi encontrada entre algumas das variáveis físicas e químicas analisadas e a comunidade fitoplanctônica. De acordo com a CCA, variáveis como a extensão da zona eufótica, temperatura, pH, nitrogênio e fósforo influenciaram diretamente na dinâmica do fitoplâncton. Organismos pertencentes à classe Cyanophyceae foram as mais representativas em todos os períodos amostrais, abrangendo os grupos funcionais K, S1, M e H. A hidrodinâmica e a variação sazonal dos fatores ambientais foram as forças determinantes da composição e abundância das assembleias de algas. Apesar do predomínio de cianobactérias, o ambiente do reservatório ainda é oligotrófico. A ausência de florações e as abundâncias populacionais relativamente baixas indicaram que a qualidade da água do reservatório continua se mantendo dentro dos limites estipulados para seus usos múltiplos.

Implications of infectious diseases and the adrenal hypothesis for the etiology of childhood acute lymphoblastic leukemia

Acute leukemia is the most frequent cancer in children. Recently, a new hypothesis was proposed for the pathogenesis of childhood acute lymphoblastic leukemia (ALL). The so-called "adrenal hypothesis" emphasized the role of endogenous cortisol in the etiology of B-cell precursor ALL. The incidence peak of ALL in children between 3 to 5 years of age has been well documented and is consistent with this view. The adrenal hypothesis proposes that the risk of childhood B-cell precursor ALL is reduced when early childhood infections induce qualitative and quantitative changes in the hypothalamus-pituitary-adrenal axis. It suggests that the increased plasma cortisol levels would be sufficient to eliminate all clonal leukemic cells originating during fetal life. Because Brazil is a continental and tropical country, the exposure to infections is diversified with endemic viral and regionally non-viral infections, with some characteristics that support the recent adrenal hypothesis. Here we discuss this new hypothesis in terms of data from epidemiological studies and the possible implications of the diversity of infections occurring in Brazilian children.

Consideraciones diagnósticas de los trastornos del espectro autista. Experienia de un servicio / Diagnostic Considerations in autism spectrum disorders: experience of a department

El proceso diagnóstico de los Trastornos Generalizados del Desarrollo (TGD) es un camino arduo para la mayoria de las familias. El tiempo hasta el diagnóstico influye en el acceso al tratamiento especifico, en el pronóstico y en el nivel de estrés familiar. Objetivo: describir la población de niños con o sin diagnóstico previo de TGD que consultaron a nuestro servicio, así como también describir el proceso del diagnóstico a través del análisis de algunas variables como: tiempo entre preocupación paterna y diagnóstico, número de profesionales consultados, conducta pediatríca y sintomas más prevalentes como motivo de consulta. Métodos: estudio transversal y retrospectivo. Se incluyeron las historias clínicas de los 76 niños atendidos en el servidio de clínicas Interdisciplinarias del Hospital Garrahan desde enero de 2004 hasta mayo de 2006. Resultados: 76 niños; relación sexo masculino; femenino 3.75:1. Los padres notaron los síntomas a los 25.5 más menos 9,1 meses y se preocuparon a los 28,2 más menos 13,5 meses. La edad de la primera consulta a un profesional fue a los 32 más menos 13.6 meses. El pedíatra fue el primer profesional que consultaron en 67,1 por ciento. La conducta del pediatra, luego de la consulta de los padres fue en el 57,6 por ciento derivar a otros profesionales y 42,4 por ciento adoptaron conducta expectante. Los padres consultaron a 3 más menos 2,3 profesionales hasta el diagnóstico definitivo. Los niños llegaron a nuestro consultorio por primera vez a la edad de 48,8 más menos 15,9 meses, variando de 25 hasta 85 meses. En 73,6 por ciento de los casos consultaron por trastornos en la comunicación, en 50 por ciento por trastornos en la socialización, en 42,1 por ciento por trastornos en la conducta y en el 32,9 por ciento por trastornos asociados. En nuestro análisis encontramos que los padres llevaron un promedio de 20 más menos 14,8 meses hasta el diagnóstico.

Preparation and cytotoxicity of cisplatin-containing liposomes

We encapsulated cisplatin into stealth pH-sensitive liposomes and studied their stability, cytotoxicity and accumulation in a human small-cell lung carcinoma cell line (GLC4) and its resistant subline (GLC4/CDDP). Since reduced cellular drug accumulation has been shown to be the main mechanism responsible for resistance in the GLC4/CDDP subline, we evaluated the ability of this new delivery system to improve cellular uptake. The liposomes were composed of dioleoylphosphatidylethanolamine (DOPE), cholesteryl hemisuccinate (CHEMS), and distearoylphosphatidylethanolamine-polyethyleneglycol 2000 (DSPE-PEG2000) and were characterized by determining the encapsulation percentage as a function of lipid concentration. Among the different formulations, DOPE/CHEMS/DSPE-PEG liposomes (lipid concentration equal to 40 mM) encapsulated cisplatin more efficiently than other concentrations of liposomes (about 20.0 percent, mean diameter of 174 nm). These liposomes presented good stability in mouse plasma which was obtained using a 0.24-M EDTA solution (70 percent cisplatin was retained inside the liposomes after 30 min of incubation). Concerning cytotoxic effects, they are more effective (1.34-fold) than free cisplatin for growth inhibition of the human lung cancer cell line A549. The study of cytotoxicity to GLC4 and GLC4/CDDP cell lines showed similar IC50 values (approximately 1.4 æM), i.e., cisplatin-resistant cells were sensitive to this cisplatin formulation. Platinum accumulation in both sensitive and resistant cell lines followed the same pattern, i.e., approximately the same intracellular platinum concentration (4.0 x 10-17 mol/cell) yielded the same cytotoxic effect. These results indicate that long-circulating pH-sensitive liposomes, also termed as stealth pH-sensitive liposomes, may present a promising delivery system for cisplatin-based cancer treatment. This liposome system proved to be able to circumvent the cisplatin resistance, whereas...

Acute leukemia in early childhood

Acute leukemia in early childhood is biologically and clinically distinct. The particular characteristics of this malignancy diagnosed during the first months of life have provided remarkable insights into the etiology of the disease. The pro-B, CD10 negative immunophenotype is typically found in infant acute leukemia, and the most common genetic alterations are the rearrangements of the MLL gene. In addition, the TEL/AML1 fusion gene is most frequently found in children older than 24 months. A molecular study on a Brazilian cohort (age range 0-23 months) has detected TEL/AML1+ve (N = 9), E2A/PBX1+ve (N = 4), PML/RARA+ve (N = 4), and AML1/ETO+ve (N = 2) cases. Undoubtedly, the great majority of genetic events occurring in these patients arise prenatally. The environmental exposure to damaging agents that give rise to genetic changes prenatally may be accurately determined in infants since the window of exposure is limited and known. Several studies have shown maternal exposures that may give rise to leukemogenic changes. The Brazilian Collaborative Study Group of Infant Acute Leukemia has found that mothers exposed to dipyrone, pesticides and hormones had an increased chance to give birth to babies with infant acute leukemia [OR = 1.48 (95 percentCI = 1.05-2.07), OR = 2.27 (95 percentCI = 1.56-3.31) and OR = 9.08 (95 percentCI = 2.95-27.96)], respectively. This review aims to summarize recent clues that have facilitated the elucidation of the biology of early childhood leukemias, with emphasis on infant acute leukemia in the Brazilian population.

DNA extraction from fixed cytogenetic cell suspensions

We developed a procedure for DNA extraction from small volumes of fixed cell suspensions previously prepared for conventional cytogenetic analysis. Good quality DNA was isolated with a fast and simple protocol using DNAzol reagent. This provided suitable DNA for various types of molecular analyses, including polymerase chain reaction, restriction fragment length polymorphism, denaturing high-performance liquid chromatography, and direct sequencing. This technique provides sufficient material for such test, which are important for diagnosis of neoplastic diseases in pediatric patients.

Cytosine arabinoside-metabolizing enzyme genes are underexpressed in children with MLL gene-rearranged acute lymphoblastic leukemia

Infant acute lymphoblastic leukemia (IALL) is characterized by mixed lineage leukemia (MLL) gene rearrangements, unique gene expression profiles, poor prognosis, and drug resistance. One exception is cytosine arabinoside (Ara-C) to which IALL cells seem to be more sensitive. We quantified mRNA expression of Ara-C key enzymes in leukemic lymphoblasts from 64 Brazilian ALL children, 15 of them presenting MLL gene rearrangement, and correlated it with clinical and biological features. The diagnosis was based on morphological criteria and immunophenotyping using monoclonal antibodies. MLL gene rearrangements were detected by conventional cytogenetic analysis, RT-PCR and/or fluorescence in situ hybridization. The DCK and HENT1 expression levels were determined by real-time quantitative PCR using SYBR Green I. Relative quantification was made by the standard curve method. The results were analyzed by Mann-Whitney and Fisher exact tests. A P value of ú0.05 was considered to be statistically significant. DCK and HENT1 expression levels were significantly lower in children with MLL gene-rearranged ALL compared to children with MLL germ line ALL (P = 0.0003 and 0.03, respectively). Our results differ from previous ones concerning HENT1 mRNA expression that observed a higher expression level in MLL gene-rearranged leukemias. In conclusion, the expression of the genes related to Ara-C metabolism was lower in MLL-positive children in the sample studied, suggesting the presence of population differences in the expression profile of these genes especially for HENT1.

Control of attention by a peripheral visual cue depends on whether the target is difficult to discriminate

The influence of a peripheral cue represented by a gray ring on responsivity to a subsequent target varies. When a vertical line inside a ring was a go target and a white small ring inside a ring was a no-go target, reaction time was shorter at the same location relative to a different location. However, no reaction time difference between the two locations occurred when a white cross inside the ring, instead of the white vertical line inside the ring, was the go target. We investigated whether this last finding was due to a forward masking influence of the cue, a requirement of low attention for the discrimination or a lack of attention mobilization by the cue. In Experiment 1, the intensity of the cue was reduced in an attempt to reduce forward masking. In Experiment 2, the vertical line and the cross were presented in the same block of trials so as to be dealt with a common attentional strategy. In Experiments 3 and 4, the no-go target was a 45° rotated cross inside a ring to increase the difficulty of the discrimination. No evidence was obtained that the cross was forward masked by the cue nor that it demanded less attention to be discriminated from the small ring. There was a facilitation of responsivity by the cue when the small ring was replaced by the rotated cross. The results suggest that when the discrimination to be performed is too easy the cue does not mobilize attention.

Capitulo 8. Perfil demográfico e socioeconômico das pessoas que se autodeclaram 'indigenas' nos censos demográficos de 1991 e 2000 / Demographic and socioeconomic profile of the people who if declaredly 'indigene' in the demographic census of 1991 and 2000

Introdução: Há uma notável carência de dados demográficos sobre as populações indígenas no Brasil. Em face da diversidade histórica, social e cultural dos povos indígenas, que somam mais de 200 etnias, falantes de 180 línguas diferentes, é praticamente nulo o que se conhece não somente acerca de sua estrutura populacional, como também dos níveis e padrões de fecundidade, mortalidade e migração, dentre outros aspectos da dinâmica demográfica (Silva, 1994; Ricardo, 1996; Azevedo, 2000; Santos & Coimbra Jr., 2003; Pagliaro et al., neste volume). Se os dados são escassos para os indígenas residentes em terras oficialmente reconhecidas pelo Estado brasileiro, são ainda menos conhecidas as características demográficas dos que vivem em áreas urbanas.

CD44 Expression in T-cell lymphoblastic leukemia

1. CD44 is an adhesion molecule expressed by B and T lymphocytes that mediates cell attachment to extracellular matrix components and specific cell surface ligands. In normal process of T-cell development, CD44 can be implicated in homing of bone marrow-derived T-cell precursors into the thymus. In hematopoietic malignancies, CD44 and other adhesion molecules can mediate the behavior of neoplastic cells such as metastatic migration. In the leukemic process, CD44 and other adhesion molecules can mediate the behavior of neoplastic cell such as metastic migration. In the leukemic process, CD44 expression is correlated with increased numbers of circulating blasts and it is present at other sites such as the central nervous system. 2. In the present study, CD44 was investigated in lymphoblasts from 30 patients with T-cell lymphoblastic leukemia (T-ALL) and peripheral lymphocytes from 10 healthy individuals. CD44 expression was detected in 23 (77 per cent) of T-ALL cases studied and was correlated with clinical features such as mediatinal mass, adenomegaly, and infiltration of the central nervous system and other ortgans. Interestingly, CD44 expression in patient with tumor infiltration was higher than in patients with no tumor infiltration. 3. These data suggest that CD44 may be regarded as an additional marker for tumor expansion in T-cell leukemias

Two novel types of bistratified amacrine cells in the chick retina: a Golgi study

1. The correlation between neurotransmitter substances in specific cell types has renewed interest in the morphology of amacrine cells. In this paper we describe the morphology of two types of amacrine cells in Golgi-stained chick retinas. 2. The first cell type was classified as an asymmetric bistratified amacrine cell suggested to play a role in the formation of complex ganglion cell receptive fields. 3. The second was classified as a bistratified amacrine cell. Their processes were stratified at sublayers 1 and 4 of the inner plexiform layer and their morphological features were similar to those of dopaminergic cells in the chick retina.

Analgesic and anti-inflammatory effects of 3-3-(phenyl)-1, 2, 4-oxadiazol-5-yl propionic acid

Significant local analgesic and anti-inflammatory activity has been observed after oral administration of 3-[3-(phenyl)-1,2,4-oxadiazol-5-yl] propionic acid (POPA). Doses of 150 and 300 mg/kg body weight administered orally by gavage to adult (25-35 g) albino mice of both sexes can inhibit acetic acid-induced writhing by 31.0 and 49.5, respectively (mean +/- SEM writhing numbers during 20 min were 52.0 +/- 6.0 and 38.3 +/- 7.2 vs 75.8 +/- 6.6 for control group which received saline; N = 6). Carrageenin-induced inflammation in the female Wistar rat (200-250 g) can be reduced by 43.3 and 42.2 3 h after oral administration (gavage) of 75 and 150 mg/kg of POPA (mean +/- SEM, 30.0 +/- 1.3 and 30.6 +/- 2.4 vs 52.9 +/- 3.7 for control group which received saline; N = 5). In the hot plate test on adult albino mice (25-35 g) of both sexes, POPA (150 and 300 mg/kg, po) was totally ineffective (N = 10). Our results indicate that POPA appears to offer potential safety and efficacy as a local analgesic and anti-inflammatory agent with no central nervous system involvement