New antibacterial germacrene from Verbesina negrensis.

Several health benefits have been attributed to members of the Verbesina genus, including promotion of urinary and gastrointestinal health. Verbesina species are also reported to exhibit antibacterial, antiparasitic, and antioxidant activities. Although members of the Verbesina genus produce various pharmacologically relevant chemicals as secondary metabolites, including eudesmanes, flavonoids, guanidine alkaloids, acetylenic compounds, and germacrenes, the active compounds required for these benefits remain unknown. To investigate potential antimicrobial activities of Verbesina negrensis, crude extracts from plant aerial structures were evaluated. Following chemical fractionation, the chloroformic extract from Verbesina negrensis was subjected to bioassay-guided isolation using disk diffusion assays to determine antimicrobial activity. The active compound was characterized as 6ß-cinnamoyloxy-1ß-hydroxy-10α-metoxy-3-oxo-germacra-4,5Z-ene (1). Fractions containing 1 inhibited both Enterococcus faecalis (ATCC 29 212) and Staphylococcus aureus (ATCC 29213). The MIC for 1 was determined by microbroth dilution assay to be 64 µg/mL for both E. faecalis and S. aureus.

Mechanism targeted discovery of antitumor marine natural products.

Antitumor drug discovery programs aim to identify chemical entities for use in the treatment of cancer. Many strategies have been used to achieve this objective. Natural products have always played a major role in anticancer medicine and the unique metabolites produced by marine organisms have increasingly become major players in antitumor drug discovery. Rapid advances have occurred in the understanding of tumor biology and molecular medicine. New insights into mechanisms responsible for neoplastic disease are significantly changing the general philosophical approach towards cancer treatment. Recently identified molecular targets have created exciting new means for disrupting tumor-specific cell signaling, cell division, energy metabolism, gene expression, drug resistance and blood supply. Such tumor-specific treatments could someday decrease our reliance on traditional cytotoxicity-based chemotherapy and provide new less toxic treatment options with significantly fewer side effects. Novel molecular targets and state-of-the-art, molecular mechanism-based screening methods have revitalized antitumor research and these changes are becoming an ever-increasing component of modern antitumor marine natural products research. This review describes marine natural products identified using tumor-specific mechanism-based assays for regulators of angiogenesis, apoptosis, cell cycle, macromolecule synthesis, mitochondrial respiration, mitosis, multidrug efflux and signal transduction. Special emphasis is placed on natural products directly discovered using molecular mechanism-based screening.

Antioxidant and antiangiogenic activity of Astronium graveolens Jacq. leaves.

Angiogenesis is involved in many physiological and pathological conditions. Natural compounds with antioxidant activity have also been reported to possess potent antiangiogenic properties by regulating angiogenesis modulators such as vascular endothelial growth factor (VEGF). Based on this, we screened the antioxidant and antiangiogenic activities of Astronium graveolens leaf extracts by a DPPH test and a competitive enzyme-linked immunosorbent assay, respectively. MeOH extract expressed a significant free radical-scavenging activity (EC50 = 37.65 µg/mL) and it was able to inhibit the interaction between placental growth factor (PlGF) (placental growth factor), a VEGF family member, and its receptor Flt-1 by more than 50% at 1 mg/mL. 1,2,3,4,6-Penta-O-galloyl-d-glucopyranose, 6 is the most active compound of the extract. It exhibited a high potency in scavenging DPPH (EC50 = 2.16 µg/mL) and reduced by 58% the PlGF/Flt-1 interaction at a concentration of 50 µM. Moreover, the known compounds (1-6) have been isolated for the first time in A. graveolens.

Chemical composition and antibacterial activity of the essential oil of Lantana camara var. moritziana.

The essential oil obtained from the leaves of Lantana camara var. moritziana (Otto & Dietr.) López-Palacios collected at Rubio, Táchira State, Venezuela, was obtained by hydrodistillation in a Clevenger trap (0.1% yield). The oil was analyzed by gas chromatography-mass spectrometry (GC/MS) on HP GC-MS System, model 5973, identifying 33 compounds (97.1%) of which the major components were germacrene D (31.0%), followed by beta-caryophyllene (14.8%), a-phellandrene (6.7%), limonene (5.7%) and 1,8-cineole (5.2%). Evaluation of the antibacterial activity by agar diffusion method with discs against international reference bacteria (Staphylococcus aureus, Enterococcus faecalis, Escherichia coli, Klebsiella pneumoniae, Salmonella Typhi, Pseudomonas aeruginosa) showed growing inhibition of E. faecalis and S. aureus at MIC of 350 mg/mL and 400 mg/mL, respectively.

Chemical composition and in vitro antibacterial activity of the essential oil of Phthirusa adunca from Venezuelan Andes.

In this paper, preliminary studies on the chemical characterization of Phthirusa adunca Meyer essential oil, obtained by hydrodistillation, is presented. The separation of the components was performed by GC-MS. Twenty-three compounds (94.5% of the sample) were identified of which the three major ones (76% of the sample) were beta-phellandrene (38.1%), germacrene D (26.8%) and beta-pinene (11.5%). The essential oil showed a broad spectrum of activity against Salmonella Typhi CDC 57 (100 microg/mL), Staphylococcus aureus ATCC 25923 (200 microg/mL), Enterococcus faecalis ATCC 29212 (250 microg/mL), Escherichia coli ATCC 25922 y Klebsiella pneumoniae ATCC 23357 (500 microg/mL). This is the first report on the composition and activity of the essential oil of this species.

Chemical composition and larvicidal activity of Eugenia triquetra essential oil from Venezuelan Andes.

The chemical constituents of the essential oil obtained by hydrodistillation of the leaves of Eugenia triquetra O. Berg, collected in Táchira State, Venezuela, were identified by GC-MS analysis. Twenty-six components, which made up 88.5% of the oil, were identified. The major constituents were linalool (17.5%), limonene (16.9%), alpha-pinene (11.6%), beta-pinene (8.7%), and p-cymene (3.7%). The essential oil was tested against third-instar larvae of Aedes aegypti, showing a LC50 value of 64.8 +/- 5.6 ppm.

Incidencia de la educación inicial en la construcción de subjetividad en niños y niñas de 3 a 5 años en situación de desplazamiento en un jardín en bogotá en el sector de bosa / Incidence of early childhood education in the construction of subjectivity of children aged from 3-5 years in displacement at kindergarten on bogota in the area of bosa

El presente artículo de investigación tuvo como finalidad comprender la incidencia de la educación inicial en la construcción de la subjetividad en siete niños y niñas de 3 a 5 años en situación de desplazamiento en un jardín infantil de la localidad de Bosa, en Bogotá. El diseño empleado fue el método cualitativo con un enfoque hermenéutico. El análisis de los resultados indica que los niños y niñas se adaptan fácilmente, identificándose con el jardín, con sus pares y con las maestras, que implica cambios profundos en sus subjetividades en la medida en que tienen más modelos a seguir, los cuales van redefiniendo sus sentidos de vida y les permiten experimentar nuevas prácticas, costumbres y vivencias.

This research paper aimed to understand the impact of the early childhood education in the construction of subjectivity in seven children in displacement aged 3 to 5 years in a kindergarten in the locality of Bosa, in Bogota. The design was the qualitative method with and hermeneutical approach. The analysis of the results indicates that children adapt easily, identifying themselves with the kindergarten, with their peers and their teachers. This implies profound changes in their subjectivity to the extent that they have more models, which are redefining their way of life and allowing them to experience new practices, customs and experiences.

Chemical composition and in vitro antibacterial activity of the essential oil of Minthostachys mollis (Kunth) Griseb Vaught from the Venezuelan Andes.

Chemical constituents of the essential oil from the leaves of Minthostachys mollis (Kunth) Griseb Vaught var. mollis collected in January 2008 at Tuñame, Trujillo State, Venezuela, were separated and identified by GC-MS analysis. The essential oil was obtained by hydrodistillation and thirteen components (98.5% of the sample) were identified by comparison with the Wiley GC-MS library data base. The two major components were pulegone (55.2%) and trans-menthone (31.5%). The essential oil showed a significant inhibitory effect against Gram-positive and Gram-negative bacteria, especially Bacillus subtilis and Salmonella typhi (4 microg/mL).

Bioassay for the identification of natural product-based activators of peroxisome proliferator-activated receptor-gamma (PPARgamma): the marine sponge metabolite psammaplin A activates PPARgamma and induces apoptosis in human breast tumor cells.

Peroxisome proliferator-activated receptors (PPARs), members of the nuclear hormone receptor (NHR) family, are ligand-activated transcription factors. Ligands (agonists) of PPARgamma have been shown to inhibit growth, promote terminal differentiation, and induce apoptosis in human breast tumor cells. A cell-based reporter assay was developed to examine extracts of terrestrial and marine organisms for the ability to activate PPARgamma. Bioassay-guided fractionation and isolation of an active extract from Pseudoceratina rhax yielded the known histone deacetylase (HDAC) inhibitor psammaplin A (1). Compound 1 activates PPARgamma in a MCF-7 cell-based reporter assay and induces apoptosis in human breast tumor cells in vitro. Molecular modeling studies suggest that 1 may interact with binding sites within the PPARgamma ligand-binding pocket. Therefore, in addition to its known effects on HDAC-mediated processes, activation of PPARgamma-regulated gene expression may play a role in the ability of 1 to induce apoptosis.

Prevención en hepatitis B / Prevention in hepatitis B

el virus de hepatitis B se propaga cuando la sangre o fluidos corporales de una persona infectada entra al cuerpo de una persona no infectada. Se ha demostrado que son infectantes la sangre, la saliva, el semen y las secreciones vaginales. Se han identificado cuatro formas de transmisión: vertical, contactos domiciliarios, sexual (horizontal) o por inyecciones o heridas de equipo contaminado, transfusión de sangre o tratamiento con derivados sanguíneos. Para la prevención de la transmisión del virus se utilizan medidas preventivas universales y la vacunación.

The virus of hepatitis B propagates when the blood or corporal fluids of an infected person enters in the body of a noninfected person. It has been proved that blood; saliva, semen and vaginal secretions are infectious. Four ways of transmission have been identified: vertical, domiciliary contacts, sexual (horizontal), or by injections or wounds from contaminated equipment; blood transfusions, or treatment with blood derivatives. To prevent virus transmission, preventive universal measures and vaccination are used.

Hepatitis por halothano: un problema no resuelto / Halothane hepatitis: an unsolved problem

Se revisaron 48.969 anestesias con halothano suministradas en las salas de operaciones del Hospital San Juan de Dios entre los años 1976 a 1982, con el propósito de determinar la incidencia de hepatitis por halothano. De este número de anestesias suministradas, 6 pacientes presentan dicha entidad lo que indica 1 caso por cada 8.000 anestesias suministradas, con una mortalidad del 50% o sea 1 caso fatal por cada 16.000 anestesias administradas con halothano. La eosinofilia no se presentó. Los casos fatales están en relación con una segunda exposición al anestésico antes de un mes de la primera. El uso de esteroides en forma temprana puede ser um factor decisivo para la sobrevida

Frecuencia respiratoria en lactantes y preescolares sanos y con infección respiratoria aguda / Respiratory rates in healthy infants and in children with acute respiratory infection

Se midió la frecuencia respiratoria (FR) a 966 niños sanos en vigilia y 263 niños sanos en sueño, estableciendo los rangos de normalidad y promedios de FR para niños de 15 días a 60 meses de vida, encontrando una gran variabilidad de este índice en relación a la edad y el estado de vigilia o sueño. Igual procedimiento se efectuó en 566 niños con infección respiratoria aguda (IRA) a los que se valoró además del estado de vigilia o sueño, el tipo de IRA baja que presentaban obstructiva o mixta y la gravedad de ésta a través de un sistema de puntuación clínica. Se mantuvo la variación de la frecuencia respiratoria en relación a los índices estudiados. Se concluye que la FR por sí sola no es un índice que sirva para catalogar la severidad de una IRA baja, aún cuando en IRA moderada y severa los niños menores de 2 años tienen una tendencia a presentar una FR sobre 60 respiraciones por minuto (resp/min) en vigilia y sobre 50 resp./min. en los mayores de 2 años