Intraperitoneal injection of zymosan in mice induces pain,inflammation and the synthesis of peptidoleukotrienes and prostaglandin E2

Intraperitoneal injection of zymosan in mice induced rapid extravasation and accumulation of plasma proteins in the peritoneal cavity. Neutrophils began to appear in the peritoneal cavity after a lag period of approximately 3 hours. The injected mice exhibited a pain response (writhing) during the first 30 minutes after injection, but writhing ceased before protein or cell accumulation had reached maximum levels. The injection of zymosan induced synthesis of PGE₂ (measured by RIA) which reached maximum levels of 30 minutes, then declined slowly. Peptido-leukotriene levels (detected by bioassay, RIA and HPLC) increased rapidly after injection, reached a peak within an hour of injection and declined to undetectable levels within 4 hours. The early peptido-LT was predominantly LTC₄, while later, LTE₄ was the major component. LTD₄ levels remained low throughout and no LTB₄ was detected at any time. Indomethacin treatment elevated levels of peptido-LTs, recued PGE₂ levels and inhibited writhing. Phenidone reduced peptido-LT levels. $\text{In}$$\text{vitro}$ studies demonstrated that zymosan stimulates LTC4 synthesis by peritoneal cells whereas LTE₄, LTD₄, LTB₄ or monoHETES were not detectable (using HPLC methods). The source of enzymes responsible for the $\text{in}$$\text{vivo}$ metabolism of LTC₄ to LTD₄ and LTE₄ could not be identified.     

Biogenic Manganese Oxides Facilitate Iodide Oxidation at pH ≤ 5

Radioactive ¹²⁹I, a byproduct of nuclear power generation, can pose risks to human health if released into the environment, where its mobility is highly dependent on speciation. Based on thermodynamic principles, ¹²⁹I should exist primarily as iodide (I^?) in most terrestrial environments; however, organo-¹²⁹I and ¹²⁹iodate are also commonly detected in contaminated soils and groundwater. To investigate the capability of biogenic manganese oxides to influence iodide speciation, 17 manganese-oxidizing bacterial strains, representing six genera, were isolated from soils of the Savannah River Site, South Carolina. The isolates produced between 2.6 and 67.1 nmole Mn oxides (ml^?1 media after 25 days, pH 6.5). Results from inhibitor assays targeting extracellular enzymes and reactive oxygen species indicated that both play a role in microbe-induced Mn(II) oxidation among the strains examined. Iodide oxidation was not observed in cultures of the most active Mn-oxidizing bacteria, Chryseobacterium sp. strain SRS1 and Chromobacterium sp. strain SRS8, or the fungus, Acremonium strictum strain KR21–2. While substantial amounts of Mn(III/IV) oxides were only generated in cultures at ≥pH 6, iodide oxidation was only observed in the presence of Mn(III/IV) oxides when the pH was ≤5. Iodide oxidation was promoted to a greater extent by synthetic Mn(IV)O₂ than biogenic Mn(III/IV) oxides under these low pH conditions (≤pH 5). These results indicate that the influence of biogenic manganese oxides on iodide oxidation and immobilization is primarily limited to low pH environments.     

Recovery of plankton from hurricane impacts in a large shallow lake

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Long-term trends in seasonal plankton dynamics in Lake Mead (Nevada-Arizona,USA) and implications for climate change

Where biodiversity conservation and environmental preservation are significant concerns, rapid assessment and monitoring of the colonization and spread of non-native species are essential for timely decision-making and response. We developed and evaluated the adequacy of a rapid assessment protocol (RAP) for detecting non-native fish species in 74 Eastern Brazilian lakes. The RAP consists of a single field day employing two surveyors to conduct interviews with local sport fishers, visual surveys of fish, angling with lures, and gillnetting. We compared our results with those from separate, intense, large sampling effort (LSE) field surveys. Despite requiring less than 1/100th of the field effort, the RAP was able to detect the presence of most non-native fish species that were reported in the same lakes by LSE surveys. Information from local sport fishers was invaluable, particularly for detecting species that were in low abundance, but was not available for lakes within a forest preserve area. Non-native introductions commonly lead to rapid and widespread invasion and adverse effects on native biota. Our results strongly suggest that the RAP could function as a cost-effective tool for efficiently assessing the presence of non-native fishes in lakes and monitoring their colonization and spread over large geographic areas.