Hypoxia and nutrient dynamics affected by marine aquaculture in a monsoon-regulated tropical coastal lagoon.

The Laoyehai (lagoon) is located at the east coast of Hainan Island in the South China Sea and has been subject to perturbations from human activities, notably marine aquaculture, and has eutrophic surface and hypoxic near-bottom waters. A lack of knowledge of hydrodynamic and biogeochemical processes is a challenge to the sustainable management of lagoon at the ecosystem level in science. Five field campaigns, including three during the southwest monsoon and two in the northeast monsoon periods, were carried out at the Laoyehai in 2008-2011. The aim of this study is to investigate the impacts of dynamic processes of hydrography and human activities on nutrient geochemistry and their relationships to the system eutrophication and hypoxia in the lagoon. In this coastal system, high levels of ammonium relative to nitrate are found, elevated phosphate skews the DIN/DIP relative to the Redfield ratio, and the dissolved silicate concentration is high because of submarine groundwater discharge. The organic fraction in the Laoyehai accounts for a large proportion of the total nutrients associated with the release of wastes from marine aquaculture. The hypoxia of near-bottom waters in the Laoyehai is created and maintained by heterotrophic processes that are fueled by organic matter, which are exacerbated by poor water exchange as a consequence of the geomorphology and weak tidal circulation.

Oncostatin M Confers Neuroprotection against Ischemic Stroke.

Cell-surface receptors provide potential targets for the translation of bench-side findings into therapeutic strategies; however, this approach for the treatment of stroke is disappointing, at least partially due to an incomplete understanding of the targeted factors. Previous studies of oncostatin M (OSM), a member of the gp130 cytokine family, have been limited, as mouse models alone may not strongly resemble the human condition enough. In addition, the precise function of OSM in the CNS remains unclear. Here, we report that human OSM is neuroprotective in vivo and in vitro by recruiting OSMRß in the setting of ischemic stroke. Using gain- and loss-of-function approaches, we demonstrated that decreased neuronal OSMRß expression results in deteriorated stroke outcomes but that OSMRß overexpression in neurons is cerebroprotective. Moreover, administering recombinant human OSM to mice before the onset of I/R showed that human OSM can be protective in rodent models of ischemic stroke. Mechanistically, OSM/OSMRß activate the JAK2/STAT3 prosurvival signaling pathway. Collectively, these data support that human OSM may represent a promising drug candidate for stroke treatment. SIGNIFICANCE STATEMENT: OSM, a member of the gp130 cytokine family, regulates neuronal function and survival. OSM engages a second receptor, either LIFRα or OSMRß, before recruiting gp130. However, it is not clear whether OSM/OSMRß signaling is involved in neuroprotection in the setting of ischemic stroke. Recent studies show that, compared with mouse disease models, the OSM receptor system in rats more closely resembles that in humans. In the present study, we use genetic manipulations of OSMRß in both mouse and rat stroke models to demonstrate that OSMRß in neurons is critical for neuronal survival during cerebral ischemic/reperfusion. Interestingly, administration of human OSM also leads to improved stroke outcomes. Therefore, OSM may represent a promising drug candidate for stroke treatment.

Hepatoprotective standardized EtOH-water extract of the leaves of Ziziphus jujuba.

The hepatoprotective activity of the EtOH-water extract of Ziziphus jujuba leaves was evaluated against CCl4-induced hepatic damage in mice. The EtOH-water extract significantly alleviated liver damage as indicated by the decreased levels of serum ALT and AST and the decreased MDA content, the increased levels of SOD, GSH and GSH-Px, and the reduced pathological tissue injury induced by CCl4. A quantitative analysis of fifteen major constituents (1-15) of the EtOH-water extract of the leaves of Z. jujuba was conducted by HPLC-DAD. Based on our research results, it can be concluded that the EtOH-water extract of the leaves of Z. jujuba is efficacious for prevention and treatment of CCl4-induced hepatic injury in mice. Flavonoids might be the active ingredients responsible for the biological and pharmacological activities towards hepatoprotection.