Propagacion germinativa de haplopappus multifolius y haplopappus taeda

Resumen (Spaniah, English)44 p.Haplopappus multifolius y Haplopappus taeda pertenecen a la flora nativa chilena. Ambas especies han sido tradicionalmente usadas en la medicina popular de nuestro país y se comercializan en el mercado informal con el nombre de Bailahuén. Con el objetivo de buscar la mejor forma de propagación por semillas de Haplopappus multifolius y Haplopappus taeda se realizaron cuatro estudios de laboratorio en el Campus Lircay de la Universidad de Talca en los meses de Mayo a Septiembre de 2000 siendo la propagación el primer paso en la domesticación de esta especie. Se determinó el porcentaje de viabilidad de las semillas con el método del tetrazolio y la germinación en condiciones de luz y de oscuridad para ambas especies. El máximo porcentaje de germinación sin pretratamientos fue de 86% para H. multifolius y de 56% para H. taeda. Para H. Taeda se evaluó el efecto de diferentes tratamientos pregerminativos para H. taeda (estratificación fría por 60 días, maceradas en agua durante 24 horas a temperatura ambiente, aplicación de ácido giberélico al 0,1% y escarificación mecánica) y la evaluación de distintos tratamientos de escarificación (mecánica y ácida, con diferentes concentraciones de ácido sulfúrico). Además se realizó un estudio complementario de propagación in vitro para Haplopappus taeda en el Laboratorio de Fisiología Vegetal de la Facultad de Química de la Universidad de Santiago en la segunda quincena de Junio de 2000. Las variables estudiadas fueron capacidad germinativa, valor máximo de Czabator y sobrevivencia. Se pudo observar que la viabilidad era mayor para Haplopappus multifolius con un valor de 86% sobre Haplopappus taeda, que obtuvo un valor de 71%. La capacidad germinativa fue mayor en H. multifolius (86%) que en H. taeda (56%); además, la presencia o ausencia de luz durante la germinación no tuvo efecto en las variables evaluadas. Para la especie H. taeda el tratamiento mejor evaluado fue el de escarificación mecánica con bisturí, alcanzando un valor de 98%. El valor máximo de Czabator también fue favorecido con este tratamiento con 6,0. Debido a la dificultad de remover la testa con bisturí se comparó un método de escarificación ácida (0,20, 40 y 100% de ácido sulfúrico por un minuto) con dos métodos de escarificación mecánica (papel lija y bisturí). La escarificación ácida (60% de ácido sulfúrico por un minuto) junto con la escarificación mecánica con papel lija resultaron ser los tratamientos mejor evaluados, con valores de 92 y 94%, respectivamente

Possible Consequences for TGF-β1 Signaling

Glycosaminoglycans are known to bind biological mediators thereby modulating their biological activity. Sulfated hyaluronans (sHA) were reported to strongly interact with transforming growth factor (TGF)-β1 leading to impaired bioactivity in fibroblasts. The underlying mechanism is not fully elucidated yet. Examining the interaction of all components of the TGF-β1:receptor complex with sHA by surface plasmon resonance, we could show that highly sulfated HA (sHA3) blocks binding of TGF-β1 to its TGF-β receptor-I (TβR-I) and -II (TβR-II). However, sequential addition of sHA3 to the TβR-II/TGF-β1 complex led to a significantly stronger recruitment of TβR-I compared to a complex lacking sHA3, indicating that the order of binding events is very important. Molecular modeling suggested a possible molecular mechanism in which sHA3 could potentially favor the association of TβR-I when added sequentially. For the first time bioactivity of TGF-β1 in conjunction with sHA was investigated at the receptor level. TβR-I and, furthermore, Smad2 phosphorylation were decreased in the presence of sHA3 indicating the formation of an inactive signaling complex. The results contribute to an improved understanding of the interference of sHA3 with TGF-β1:receptor complex formation and will help to further improve the design of functional biomaterials that interfere with TGF-β1-driven skin fibrosis

Risk of decompression illness among 230 divers in relation to the presence and size of patent foramen ovale

Background The risk of developing decompression illness (DCI) in divers with a patent foramen ovale (PFO) has not been directly determined so far; neither has it been assessed in relation to the PFO's size. Methods In 230 scuba divers (age 39±8 years), contrast trans-oesophageal echocardiography (TEE) was performed for the detection and size grading (0-3) of PFO. Prior to TEE, the study individuals answered a detailed questionnaire about their health status and about their diving habits and accidents. For inclusion into the study, ⩾200 dives and strict adherence to decompression tables were required. Results Sixty-three divers (27%) had a PFO. Overall, the absolute risk of suffering a DCI event was 2.5 per 104 dives. There were 18 divers (29%) with, and 10 divers (6%) without, PFO who had experienced ⩾1 major DCI events \batchmode \documentclass[fleqn,10pt,legalpaper]{article} \usepackage{amssymb} \usepackage{amsfonts} \usepackage{amsmath} \pagestyle{empty} \begin{document} $(P=0.016)$ \end{document}. In the group with PFO, the incidence per 104 dives of a major DCI, a DCI lasting longer than 24 h and of being treated in a decompression chamber amounted to 5.1 (median 0, interquartile range [IQR] 0-10.0), 1.9 (median 0, IQR 0-4.0) and 3.6 (median 0, IQR 0-9.8), respectively and was 4.8-12.9-fold higher than in the group without PFO \batchmode \documentclass[fleqn,10pt,legalpaper]{article} \usepackage{amssymb} \usepackage{amsfonts} \usepackage{amsmath} \pagestyle{empty} \begin{document} $(P{<}0.001)$ \end{document}. The risk of suffering a major DCI, of a DCI lasting longer than 24 h and of being treated by recompression increased with rising PFO size. Conclusion The presence of a PFO is related to a low absolute risk of suffering five major DCI events per 104 dives, the odds of which is five times as high as in divers without PFO. The risk of suffering a major DCI parallels PFO siz

Enzyme-Mediated Quenching of the Pseudomonas Quinolone Signal (PQS):A Comparison between Naturally Occurring and Engineered PQS-Cleaving Dioxygenases

The opportunistic pathogen Pseudomonas aeruginosa employs quorum sensing to govern the production of many virulence factors. Interference with quorum sensing signaling has therefore been put forward as an attractive approach to disarm this pathogen. Here, we analyzed the quorum quenching properties of natural and engineered (2-alkyl-)3-hydroxy-4(1H)-quinolone 2,4-dioxygenases (HQDs) that inactivate the P. aeruginosa signal molecule PQS (Pseudomonas quinolone signal; 2-heptyl-3-hydroxy-4(1H)-quinolone). When added exogenously to P. aeruginosa cultures, all HQDs tested significantly reduced the levels of PQS and other alkylquinolone-type secondary metabolites deriving from the biosynthetic pathway, such as the respiratory inhibitor 2-heptyl-4-hydroxyquinoline N-oxide. HQDs from Nocardia farcinica and Streptomyces bingchenggensis, which combine low K(M) values for PQS with thermal stability and resilience in the presence of P. aeruginosa exoproducts, respectively, attenuated production of the virulence factors pyocyanin and pyoverdine. A delay in mortality was observed when Galleria mellonella larvae were infected with P. aeruginosa suspensions treated with the S. bingchenggensis HQD or with inhibitors of alkylquinolone biosynthesis. Our data indicate that quenching of PQS signaling has potential as an anti-virulence strategy; however, an efficient anti-virulence therapy against P. aeruginosa likely requires a combination of agents addressing multiple targets

Pulmonary exposure to carbonaceous nanomaterials and sperm quality

Abstract Background Semen quality parameters are potentially affected by nanomaterials in several ways: Inhaled nanosized particles are potent inducers of pulmonary inflammation, leading to the release of inflammatory mediators. Small amounts of particles may translocate from the lungs into the lung capillaries, enter the systemic circulation and ultimately reach the testes. Both the inflammatory response and the particles may induce oxidative stress which can directly affect spermatogenesis. Furthermore, spermatogenesis may be indirectly affected by changes in the hormonal milieu as systemic inflammation is a potential modulator of endocrine function. The aim of this study was to investigate the effects of pulmonary exposure to carbonaceous nanomaterials on sperm quality parameters in an experimental mouse model. Methods Effects on sperm quality after pulmonary inflammation induced by carbonaceous nanomaterials were investigated by intratracheally instilling sexually mature male NMRI mice with four different carbonaceous nanomaterials dispersed in nanopure water: graphene oxide (18 μg/mouse/i.t.), Flammruss 101, Printex 90 and SRM1650b (0.1 mg/mouse/i.t. each) weekly for seven consecutive weeks. Pulmonary inflammation was determined by differential cell count in bronchoalveolar lavage fluid. Epididymal sperm concentration and motility were measured by computer-assisted sperm analysis. Epididymal sperm viability and morphological abnormalities were assessed manually using Hoechst 33,342/PI flourescent and Spermac staining, respectively. Epididymal sperm were assessed with regard to sperm DNA integrity (damage). Daily sperm production was measured in the testis, and testosterone levels were measured in blood plasma by ELISA. Results Neutrophil numbers in the bronchoalveolar fluid showed sustained inflammatory response in the nanoparticle-exposed groups one week after the last instillation. No significant changes in epididymal sperm parameters, daily sperm production or plasma testosterone levels were found. Conclusion Despite the sustained pulmonary inflammatory response, an eight week exposure to graphene oxide, Flammruss 101, Printex 90 and the diesel particle SRM1650b in the present study did not appear to affect semen parameters, daily sperm production or testosterone concentration in male NMRI mice

Format zorgpad Voeding bij kanker

Het zorgpad ‘Voeding bij kanker’ beschrijft het (logistiek) pad dat de oncologische patiënt doorloopt binnen de voedingszorg vanaf het moment dat screening op behoefte aan voedingszorg plaatsvindt en verwijzing naar de diëtist tot en met follow-up of palliatieve fase. Hierbij zijn het format en de indeling aangehouden van de IKNL-formats van (niet-)tumorspecifieke zorgpade

Feasibility Assessment of Micro-Electrode Chip Assay as a Method of Detecting Neurotoxicity in vitro

Detection and characterization of chemically induced toxic effects in the nervous system represent a challenge for the hazard assessment of chemicals. In vivo, neurotoxicological assessments exploit the fact that the activity of neurons in the central and peripheral nervous system has functional consequences. And so far, no in vitro method for evaluating the neurotoxic hazard has yet been validated and accepted for regulatory purpose. The micro-electrode array (MEA) assay consists of a culture chamber into which an integrated array of micro-electrodes is capable of measuring extracellular electrophysiology (spikes and bursts) from electro-active tissues. A wide variety of electrically excitable biological tissues may be placed onto the chips including primary cultures of nervous system tissue. Recordings from this type of in vitro cultured system are non-invasive, give label free evaluations and provide a higher throughput than conventional electrophysiological techniques. In this paper, 20 substances were tested in a blinded study for their toxicity and dose–response curves were obtained from fetal rat cortical neuronal networks coupled to MEAs. The experimental procedure consisted of evaluating the firing activity (spiking rate) and modification/reduction in response to chemical administration. Native/reference activity, 30 min of activity recording per dilution, plus the recovery points (after 24 h) were recorded. The preliminary data, using a set of chemicals with different mode-of-actions (13 known to be neurotoxic, 2 non-neuroactive and not toxic, and 5 non-neuroactive but toxic) show good predictivity (sensitivity: 0.77; specificity: 0.86; accuracy: 0.85). Thus, the MEA with a neuronal network has the potency to become an effective tool to evaluate the neurotoxicity of substances in vitro

Assessing the discordance rate between local and central HER2 testing in women with locally determined HER2-negative breast cancer.

BackgroundThe importance of human epidermal growth factor receptor 2 (HER2) as a prognostic and predictive marker in invasive breast cancer is well established. Accurate assessment of HER2 status is essential to determine optimal treatment options.MethodsBreast cancer tumor tissue samples from the VIRGO observational cohort tissue substudy that were locally HER2-negative were retested centrally with both US Food and Drug Administration (FDA)-approved immunohistochemistry (IHC) and fluorescence in situ hybridization (FISH) assays, using FDA-approved assay cutoffs; results were compared.ResultsOf the 552 unique patient samples centrally retested with local HER2-negative results recorded, tumor samples from 22 (4.0%) patients were determined to be HER2-positive (95% confidence interval [CI] = 2.5%-5.7%). Of these, 18 had been tested locally by only one testing methodology; 15 of 18 were HER2-positive after the central retesting, based on the testing methodology not performed locally. Compared with the 530 patients with centrally confirmed HER2-negative tumors, the 22 patients with centrally determined HER2-positive tumors were younger (median age 56.5 versus 60.0 years) and more likely to have ER/PR-negative tumors (27.3% versus 22.3%). These patients also had shorter median progression-free survival (6.4 months [95% CI = 3.8-15.9 months] versus 9.1 months [95% CI = 8.3-10.3 months]) and overall survival (25.9 months [95% CI = 13.8-not estimable] versus 27.9 months [95% CI = 25.0-32.9 months]).ConclusionsThis study highlights the limitations of employing just one HER2 testing methodology in current clinical practice. It identifies a cohort of patients who did not receive potentially efficacious therapy because their tumor HER2-positivity was not determined by the test initially used. Because of inherent limitations in testing methodologies, it is inadvisable to rely on a single test to rule out potential benefit from HER2-targeted therapy