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Massive Release (massive + release)

Distribution by Scientific Domains

Medical Sciences	50%
Life Sciences	50%

Selected Abstracts

PRODUCTION AND RELEASE OF GEOSMIN BY THE CYANOBACTERIUM OSCILLATORIA SPLENDIDA ISOLATED FROM A PHOENIX WATER SOURCE

JOURNAL OF PHYCOLOGY, Issue 2001
Article first published online: 24 SEP 200
Hu, Q.1, Sommerfeld, M.1 Lowry, D.1, Dempster, T.1, Westerhoff, P.2, Baker, L.3, Bruce, D. & Nguyen, M. L.2 1Department of Plant Biology and 2Department of Civil and Environmental Engineering, Arizona State University, Tempe, Arizona 85287; 3Baker Environmental Consulting, 8001 Greenwood Drive, Moundview, MN 55112 Geosmin is a common component of the off-flavors detected in the drinking water supply sources of metropolitan Phoenix (Arizona). A cyanobacterium, Oscillatoria splendida, was isolated from source water during incidents of elevated geosmin production and was implicated as a cause of earthy/musty off-flavors in the drinking water. Production of geosmin was found to be constitutive in O. splendida during all growth stages. Effects of environmental parameters on the growth characteristics, and on production and release of geosmin by O. splendida, was studied under laboratory conditions. The specific growth rate and cell-bound geosmin increased with increasing temperature from 12 to 26 °C, the range of water temperatures that occur in the drinking water supply. On a per-chlorophyll a basis, however, more geosmin was released from the cells at lower temperatures. An inverse relationship was evident between light intensity and O. splendida growth and the release of geosmin. Cell-bound geosmin, however, was higher at higher light intensities. Dark incubation initially stimulated the biosynthesis of geosmin, whereas a prolonged period of darkness (2-3 weeks) resulted in massive release of geosmin into the culture medium from lysis and cellular decomposition. Dissolved nitrogen appeared to be the limiting nutrient for O. splendida in the local water supply source. When nitrate was added to laboratory cultures, both growth and geosmin production increased. These results will be discussed in context with episodes of off-flavors in drinking waters in metropolitan Phoenix, Arizona. [source]

Release of prostaglandin D2 and leukotriene C4 in response to hyperosmolar stimulation of mast cells

ALLERGY, Issue 12 2006
M. Gulliksson
Background:, Mannitol-induced bronchoconstriction in subjects with exercise-induced asthma is associated with increased urinary excretion of 9,, 11, -PGF2, a metabolite of prostaglandin D2 (PGD2) serving as a mast cell marker. It has however been questioned whether or not human mast cells release PGD2 and leukotriene C4 (LTC4) after osmotic challenge with mannitol in vitro. Methods:, Cord blood-derived human mast cells were stimulated osmotically, immunologically or with a combination of both. Supernatants were analysed for PGD2, LTC4 and histamine contents with enzyme immunoassays. Results:, Significant release of de novo synthesized eicosanoids, predominantly PGD2 [12 (8.8, 14) pmol/106cells; median (25th, 75th percentile) but also LTC4 (0.1 (0.08, 0.15) pmol/106 cells] were found in mast cells in vitro in response to 0.7 M mannitol stimulation. A massive release of histamine [70 (5.3)% of total; mean (SEM)] was also found. There were no correlations between the levels of released mediators after mannitol stimulation. In contrast, there was a correlation between release of PGD2 and LTC4, following immunological stimulation. Conclusion:, The findings support that hyperosmolar challenge activates mast cells, but different than antigen stimulation. [source]

Early Renal Ischemia-Reperfusion Injury in Humans Is Dominated by IL-6 Release from the Allograft

AMERICAN JOURNAL OF TRANSPLANTATION, Issue 7 2009
D. K. De Vries
The pathophysiology of ischemia/reperfusion (I/R) injury is complex, and current knowledge of I/R injury in humans is incomplete. In the present study, human living-donor kidney transplantation was used as a highly reproducible model to systematically study various processes potentially involved in early I/R injury. Unique, direct measurements of arteriovenous concentration differences over the kidney revealed massive release of interleukin (IL)-6 in the first 30 minutes of graft reperfusion and a modest release of IL-8. Among the assessed markers of oxidative and nitrosative stress, only 15(S)-8- iso -PGF2, was released. When assessing cell activation, release of prothrombin factor 1 + 2 indicated thrombocyte activation, whereas there was no release of markers for endothelial activation or neutrophil activation. Common complement activation complex sC5b-9 was not released into the bloodstream, but was released into urine rapidly after reperfusion. To investigate whether IL-6 plays a modulating role in I/R injury, a mouse experiment of renal I/R injury was performed. Neutralizing anti-IL-6 antibody treatment considerably worsened kidney function. In conclusion, this study shows that renal I/R in humans is dominated by local IL-6 release. Neutralization of IL-6 in mice resulted in a significant aggravation of renal I/R injury. [source]

Detecting hybridization between wild species and their domesticated relatives

MOLECULAR ECOLOGY, Issue 1 2008
ETTORE RANDI
Abstract The widespread occurrence of free-ranging domestic or feral carnivores (dogs, cats) or ungulates (pigs, goats), and massive releases of captive-reproduced game stocks (galliforms, waterfowl) is raising fear that introgressive hybridization with wild populations might disrupt local adaptations, leading to population decline and loss of biodiversity. Detecting introgression through hybridization is problematic if the parental populations cannot be sampled (unlike in classical stable hybrid zones), or if hybridization is sporadic. However, the use of hypervariable DNA markers (microsatellites) and new statistical methods (Bayesian models), have dramatically improved the assessment of cryptic population structure, admixture analyses and individual assignment testing. In this paper, I summarize results of projects aimed to identify occurrence and extent of introgressive hybridization in European populations of wolves (Canis lupus), wildcats (Felis silvestris), rock partridges and red-legged partridges (Alectoris graeca and Alectoris rufa), using genetic methods. Results indicate that introgressive hybridization can be locally pervasive, and that conservation plans should be implemented to preserve the integrity of the gene pools of wild populations. Population genetic methods can be fruitfully used to identify introgressed individuals and hybridizing populations, providing data which allow evaluating risks of outbreeding depression. The diffusion in the wild of invasive feral animals, and massive restocking with captive-reproduced game species, should be carefully controlled to avoid loss of genetic diversity and disruption of local adaptations. [source]