Nervous end-structures in the human neurohypophysis

Different types of nervous terminations were described in the human neurohypophysis. The fibers of the hypothalamo-hypophysial tract terminate in the ventricular wall, on blood vessels and around pituicytes; they form terminal networks and end-glomeruli. Verschiedene Typen von Nervenendungen werden in der Neurohypophyse beschrieben. Die Fasern des Tractus hypothalamo-hypophyseus endigen in der Wand des Ventrikels, an Blutgefäen und um Pituicyten. Sie bilden ein terminales Netzwerk und Endglomeruli. Les différents types des terminaisons nerveuses sont décrits dans la neurohypophyse humaine. Les fibres du tractus hypothalamo-hypophysaire se terminent dans la paroi ventriculaire, près de vaisseaux sanguins et dans les environs de pituicites. Elles forment des réseaux terminaux et des glomerules terminaux.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/41655/1/702_2005_Article_BF01227771.pd

Acetate-induced apoptosis in colorectal carcinoma cells involves lysosomal membrane permeabilization and cathepsin D release

Colorectal carcinoma (CRC) is one of the most common causes of cancer-related mortality. Short-chain fatty acids secreted by dietary propionibacteria from the intestine, such as acetate, induce apoptosis in CRC cells and may therefore be relevant in CRC prevention and therapy. We previously reported that acetic acid-induced apoptosis in Saccharomyces cerevisiae cells involves partial vacuole permeabilization and release of Pep4p, the yeast cathepsin D (CatD), which has a protective role in this process. In cancer cells, lysosomes have emerged as key players in apoptosis through selective lysosomal membrane permeabilization (LMP) and release of cathepsins. However, the role of CatD in CRC survival is controversial and has not been assessed in response to acetate. We aimed to ascertain whether LMP and CatD are involved in acetate-induced apoptosis in CRC cells. We showed that acetate per se inhibits proliferation and induces apoptosis. More importantly, we uncovered that acetate triggers LMP and CatD release to the cytosol. Pepstatin A (a CatD inhibitor) but not E64d (a cathepsin B and L inhibitor) increased acetateinduced apoptosis of CRC cells, suggesting that CatD has a protective role in this process. Our data indicate that acetate induces LMP and subsequent release of CatD in CRC cells undergoing apoptosis, and suggest exploiting novel strategies using acetate as a prevention/therapeutic agent in CRC, through simultaneous treatment with CatD inhibitors.This work was supported by the Fundação para a Ciência e Tecnologia (FCT) research project PTDC/BIA-BCM/69448/2006 and FCT PhD grants for SA (SFRH/BD/64695/2009) and CO (SFRH/BD/77449/2011). This work was also supported by FEDER through POFC—COMPETE, and by national funds from FCT through the project PEst-C/BIA/UI4050/2011

Izolacija i sposobnost hvatanja slobodnih radikala cijanidin 3-O-glikozida iz plodova Ribes biebersteinii Berl.

The reversed-phase preparative high performance liquid chromatographic purification of the methanol extract of the fruits of Ribes biebersteinii Berl. (Grossulariaceae) afforded five cyanidin glycosides, 3-O-sambubiosyl-5-O-glucosyl cyanidin (1), cyanidin 3-O-sambubioside (2), cyanidin 3-O-glucoside (3), cyanidin 3-O-(2G-xylosyl)-rutinoside (4) and cyanidin 3-O-rutinoside (5). They showed considerable free-radical-scavenging properties in the 2,2-diphenyl-1-picrylhydrazyl (DPPH) assay with the RC50 values of 9.29 × 106, 9.33 × 106, 8.31 × 106, 8.96 × 106 and 9.55 × 106 mol L1, respectively. The structures of these compounds were elucidated by various chemical hydrolyses and spectroscopic means. The total anthocyanin content was 1.9 g per 100 g dried fruits on cyanidin 3-glucoside basis.Pet cijanidin glikozida, 3-O-sambubiozil-5-O-glukozil cijanidin (1), cijanidin 3-O-sambubiozid (2), cijanidin 3-O-glukozid (3), cijanidin 3-O-(2G-ksilozil)-rutinozid (4) i cijanidin 3-O-rutinosid (5) izolirani su iz metanolnog ekstrakta plodova Ribes biebersteinii Berl. (Grossulariaceae) koristeći reverzno-faznu preparativnu tekućinsku kromatografiju visoke učinkovitosti. Cijanidin glikozidi pokazali su sposobnost hvatanja slobodnih radikala u pokusu s 2,2-difenil-1-pikrilhidrazilom (DPPH). Dobivene su sljedeće RC50 vrijednosti: 9,29 × 106, 9,33 × 106, 8,31 × 106, 8,96 × 106, odnosno 9,55 × 106 mol L1. Strukture glikozida određene su kemijskom hidrolizom i spektroskopijom masa. Ukupni sadržaj antocijanina bio je 1,9 g na 100 g suhih plodova preračunato na cijanidin 3-glukozid

The main actors involved in parasitization of Heliothis virescens larva

At the moment of parasitization by another insect, the host Heliothis larva is able to defend itself by the activation of humoral and cellular defenses characterized by unusual reactions of hemocytes in response to external stimuli. Here, we have combined light and electron microscopy, staining reactions, and immunocytochemical characterization to analyze the activation and deactivation of one of the most important immune responses involved in invertebrates defense, i.e., melanin production and deposition. The insect host/parasitoid system is a good model to study these events. The activated granulocytes of the host insect are a major repository of amyloid fibrils forming a lattice in the cell. Subsequently, the exocytosed amyloid lattice constitutes the template for melanin deposition in the hemocel. Furthermore, cross-talk between immune and neuroendocrine systems mediated by hormones, cytokines, and neuromodulators with the activation of stress-sensoring circuits to produce and release molecules such as adrenocorticotropin hormone, alpha melanocyte-stimulating hormone, and neutral endopeptidase occurs. Thus, parasitization promotes massive morphological and physiological modifications in the host insect hemocytes and mimics general stress conditions in which phenomena such as amyloid fibril formation, melanin polymerization, pro-inflammatory cytokine production, and activation of the adrenocorticotropin hormone system occur. These events observed in invertebrates are also reported in the literature for vertebrates, suggesting that this network of mechanisms and responses is maintained throughout evolution

Extensive retreat of Greenland tidewater glaciers 2000-2010

Overall mass loss from the Greenland ice sheet nearly doubled during the early 2000s resulting in an increased contribution to sea-level rise, with this step-change being mainly attributed to the widespread frontal retreat and accompanying dynamic thinning of tidewater glaciers. Changes in glacier calving-front positions are easily derived from remotely sensed imagery and provide a record of dynamic change. However, ice-sheet-wide studies of calving fronts have been either spatially or temporally limited. In this study multiple calving-front positions were derived for 199 Greenland marine-terminating outlet glaciers with width greater than 1 km using Landsat imagery for the 11-year period 2000–2010 in order to identify regional seasonal and inter-annual variations. During this period, outlet glaciers were characterized by sustained and substantial retreat summing to more than 267 km, with only 11 glaciers showing overall advance. In general, the pattern of mass loss detected by GRACE (Gravity Recovery and Climate Experiment) and other measurements is reflected in the calving record of Greenland glaciers. Our results suggest several regions in the south and east of the ice sheet likely share controls on their dynamic changes, but no simple single control is apparent

Cardiovascular effects of sub-daily levels of ambient fine particles: a systematic review

<p>Abstract</p> <p>Background</p> <p>While the effects of daily fine particulate exposure (PM) have been well reviewed, the epidemiological and physiological evidence of cardiovascular effects associated to sub-daily exposures has not. We performed a theoretical model-driven systematic non-meta-analytical literature review to document the association between PM sub-daily exposures (≤6 hours) and arrhythmia, ischemia and myocardial infarction (MI) as well as the likely mechanisms by which sub-daily PM exposures might induce these acute cardiovascular effects. This review was motivated by the assessment of the risk of exposure to elevated sub-daily levels of PM during fireworks displays.</p> <p>Methods</p> <p>Medline and Elsevier's EMBase were consulted for the years 1996-2008. Search keywords covered potential cardiovascular effects, the pollutant of interest and the short duration of the exposure. Only epidemiological and experimental studies of adult humans (age > 18 yrs) published in English were reviewed. Information on design, population and PM exposure characteristics, and presence of an association with selected cardiovascular effects or physiological assessments was extracted from retrieved articles.</p> <p>Results</p> <p>Of 231 articles identified, 49 were reviewed. Of these, 17 addressed the relationship between sub-daily exposures to PM and cardiovascular effects: five assessed ST-segment depression indicating ischemia, eight assessed arrhythmia or fibrillation and five considered MI. Epidemiologic studies suggest that exposure to sub-daily levels of PM is associated with MI and ischemic events in the elderly. Epidemiological studies of sub-daily exposures suggest a plausible biological mechanism involving the autonomic nervous system while experimental studies suggest that vasomotor dysfunction may also relate to the occurrence of MI and ischemic events.</p> <p>Conclusions</p> <p>Future studies should clarify associations between cardiovascular effects of sub-daily PM exposure with PM size fraction and concurrent gaseous pollutant exposures. Experimental studies appear more promising for elucidating the physiological mechanisms, time courses and causes than epidemiological studies which employ central pollution monitors for measuring effects and for assessing their time course. Although further studies are needed to strengthen the evidence, given that exposure to sub-daily high levels of PM (for a few hours) is frequent and given the suggestive evidence that sub-daily PM exposures are associated with the occurrence of cardiovascular effects, we recommend that persons with cardiovascular diseases avoid such situations.</p

Amplified melt and flow of the Greenland ice sheet driven by late-summer cyclonic rainfall

Intense rainfall events significantly affect Alpine and Alaskan glaciers through enhanced melting, ice-flow acceleration and subglacial sediment erosion, yet their impact on the Greenland ice sheet has not been assessed. Here we present measurements of ice velocity, subglacial water pressure and meteorological variables from the western margin of the Greenland ice sheet during a week of warm, wet cyclonic weather in late August and early September 2011. We find that extreme surface runoff from melt and rainfall led to a widespread acceleration in ice flow that extended 140 km into the ice-sheet interior. We suggest that the late-season timing was critical in promoting rapid runoff across an extensive bare ice surface that overwhelmed a subglacial hydrological system in transition to a less-efficient winter mode. Reanalysis data reveal that similar cyclonic weather conditions prevailed across southern and western Greenland during this time, and we observe a corresponding ice-flow response at all land- and marine-terminating glaciers in these regions for which data are available. Given that the advection of warm, moist air masses and rainfall over Greenland is expected to become more frequent in the coming decades, our findings portend a previously unforeseen vulnerability of the Greenland ice sheet to climate change