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1.
Efficacy of proteins can be enhanced by using polyethylene glycol (PEG) conjugation (PEGylation) to the protein molecules. Mobile non-toxic PEG chains conjugated to bio-therapeutics increase their hydrodynamic volume and in turn can prolong their plasma retention time and increase their solubility. An important aspect of PEGylation is the selection of PEG molecule with suitable structure and molecular weight. In this study, conceiving the idea that branched PEG-conjugates show superior efficacy over the linear PEG-conjugates, a tri-branched PEG-interferon (mPEG3L2-IFN) was synthesized by reacting a 30 KDa tri-branched mPEG3L2-NHS reagent with IFN to improve its pharmacokinetic properties and reduce the loss of in vitro bioactivity (which is generally exhibited by PEGylation) of the conjugated protein to some extent. The PEGylation procedure was optimized in terms of concentration and molar ratios of reactants, reaction time, temperature and pH conditions of the reaction mix. The conjugate was purified by cation exchange chromatography and characterized by SDS-PAGE and SE-HPLC. Trypsin digestion of mPEG3L2-IFN indicated a single site specificity of PEGylation. Anti viral bioactivity of mPEG3L2-IFN was found to be 2.38 × 107 IU/mg which is approximately 9.52% of native IFNα2 (2.5 × 108 IU/mg) and better than PEGasys from Roche Pharma. Therefore, it is reported that the tri-branched mPEG3L2-NHS reagent has the potential to be used to conjugate proteins for the promising therapeutic results.  相似文献
2.
Nitric oxide function and signalling in plant disease resistance   总被引:1,自引:0,他引:1  
Nitric oxide (NO) is one of only a handful of gaseous signalling molecules. Its discovery as the endothelium-derived relaxing factor (EDRF) by Ignarro revolutionized how NO and cognate reactive nitrogen intermediates, which were previously considered to be toxic molecules, are viewed. NO is now emerging as a key signalling molecule in plants, where it orchestrates a plethora of cellular activities associated with growth, development, and environmental interactions. Prominent among these is its function in plant hypersensitive cell death and disease resistance. While a number of sources for NO biosynthesis have been proposed, robust and biologically relevant routes for NO production largely remain to be defined. To elaborate cell death during an incompatible plant-pathogen interaction NO functions in combination with reactive oxygen intermediates. Furthermore, NO has been shown to regulate the activity of metacaspases, evolutionary conserved proteases that may be intimately associated with pathogen-triggered cell death. NO is also thought to function in multiple modes of plant disease resistance by regulating, through S-nitrosylation, multiple nodes of the salicylic acid (SA) signalling pathway. These findings underscore the key role of NO in plant-pathogen interactions.  相似文献
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4.
The role of Toll-like receptor 4 (TLR4) in the activation of innate immunity has been extensively studied in the past several years. Here, we are the first to report that myeloid-related protein 8 (MRP8), an endogenous TLR4 ligand, is involved in the epileptogenesis of mesial temporal lobe epilepsy (MTLE). We find that the expression of MRP8, TLR4, and interleukin 1-β (IL-1β) was upregulated in a MTLE model during both acute and chronic disease stages. We next investigated the possible roles played by astrocytes, which have been shown to be the major source of IL-1β during epilepsy. Stimulation via MRP8 led to the induction of IL-1β in astrocytes in vitro, accompanied by the activation of Nuclear Factor-κB, while knockdown of TLR4 or inhibition of NF-κB in astrocytes prevented this IL-1β induction. Thus, MRP8 may potentiate the perpetuation of MTLE by activating the NF-κB pathway in astrocytes, and could be a new target for anticonvulsant therapies.  相似文献
5.
The aim of the present work was to study the effects of photoperiod, salinity and pH on growth and lipid content of Pavlova lutheri microalgae for biodiesel production in small-scale and large-scale open-pond tanks. In a 250-mL flask, the cultures grew well under 24 h illumination with maximum specific growth rate, μ max , of 0.12 day?1 and lipid content of 35 % as compared to 0.1 day?1 and 15 % lipid content in the dark. The salinity was optimum for the cell growth at 30–35 ppt, but the lipid content of 34–36 % was higher at 35–40 ppt. Algal growth and lipid accumulation was optimum at pH 8–9. Large-scale cultivation in 5-L and 30-L tanks achieved μ max of 0.13–0.14 day?1 as compared to 0.12 day?1 in small-scale and 300L cultures.  相似文献
6.
Owing to better understanding of subsurface geochemical carbon recycling and real-time active methanogenesis in major coal basins around the globe, substantial share of subsurface methane generation is attributed to biogenic origin. Since coal, being complex geopolymer, does not appear to be a favorable microbial substrate, enhancement in biogenic methane yield depends on its degradation into simpler organic substrates. This review puts forward a comparative analysis of fungal and bacterial pretreatment for determining the extent of facilitation in initial degradation of coal, which is still rate limiting step in overall conversion of coal into methane. Primarily, the initial fungal degradation of coal differs from bacterial pretreatment of coal in terms of the nature of released organics. On the basis of previous reports, fungal pretreatment of coal yields, majorly, polyaromatic hydrocarbons, however, bacterial pretreatment results in the generation of mixed organics pool of aromatics and aliphatics. The presence of aliphatics may be prospected for achieving greater conversion rates of coal conversion into methane. Considering the criticality of preliminary degradation of coal and associated issues, the fate of commercial biogenic methane generation would be dictated by the factors pertaining to geological considerations and reservoir geology, chemistry of coal and associated water tables, geomicrobial considerations and economic viability.  相似文献
7.
Microbial fuel cell (MFC) technology is an emerging area for alternative renewable energy generation and it offers additional opportunities for environmental bioremediation. Recent scientific studies have focused on MFC reactor design as well as reactor operations to increase energy output. The advancement in alternative MFC models and their performance in recent years reflect the interests of scientific community to exploit this technology for wider practical applications and environmental benefit. This is reflected in the diversity of the substrates available for use in MFCs at an economically viable level. This review provides an overview of the commonly used MFC designs and materials along with the basic operating parameters that have been developed in recent years. Still, many limitations and challenges exist for MFC development that needs to be further addressed to make them economically feasible for general use. These include continued improvements in fuel cell design and efficiency as well scale-up with economically practical applications tailored to local needs.  相似文献
8.
Human biosynthetic insulin is a polypeptide hormone that plays an important and essential role in control of the level of carbohydrate, protein, and fat metabolism in the blood. Human pancreatic insulin was labeled with 99mTc to form a new radiopharmaceutical with a labeling yield of 99 ± 1% under optimum conditions: 0.1 mL insulin, pH 7, 25 μg stannous chloride, 1 mL (19 mCi) of pertechnetate, room temperature, and 10 min reaction time. The 99mTc–insulin complex was examined using paper chromatography, ITLC, electrophoresis, and HPLC. In addition, in vitro and in vivo study of 99mTc–insulin complex was performed at different time intervals.  相似文献
9.
This study investigates the potential health risk assessment of heavy metals consumption through wild plants (WPs) irrigated with wastewater and fresh water in the Bannu district, Pakistan. Therefore, soil and WP samples were collected and analyzed for heavy metals by atomic absorption spectrophotometer (Varian FAAS-240). Wastewater irrigated soil showed an elevated level for Cd (5.05–14.50 mg/Kg) and Ni (99.35–104.85 mg/Kg), while Cd (3.35–4.84 mg/Kg) concentration in the fresh water irrigated soil also surpassed the maximum allowable limits (MAL) set by the World Health Organization. Similarly, selected wastewater irrigated plants and fresh water irrigated plants also exceeded the MAL set by the Food and Agriculture Organization for Cd, Pb, and Cr (except for Cr in Vicia sativa). Heavy metal concentrations through WPs consumption were evaluated for the health risk index (HRI). The HRI value for each selected WPs was <1. However, total HRI values through WPs consumption was >1. Therefore, WPs consumption of the study area may pose a potential threat to the local community.  相似文献
10.
This study probes heavy metals (HMs) concentration in groundwater, soil, vegetables, chicken eggs, and buffalo milk samples collected from different land-use types (LUT) with special emphasis on human health risk via their consumption. Our results depicted that HMs (Ni, Cr, Pb, and Cd) concentration in groundwater of all LUT; Cd concentration in agricultural soil; Ni, Cr, Mn, Cd, and Pb concentration in buffalo milk; and Ni, Cd concentration in chicken eggs of all LUT surpassed the recommended permissible limits. While, on the other hand, Cr concentration in industrial and Pb concentration in agricultural LUT also exceeded permissible limits in the case of chicken egg samples. The concentration of Cr, Pb, and Cd in most of the vegetable samples of different LUT also crossed permissible limits. The accumulation factor for selected HMs followed trends for different LUT as Industrial > Agricultural > Residential, showing the transfer of risk from soil to vegetables. Our results for principle component analysis unravel that, unlike residential, industrial, and agricultural, LUT were highly affected from metals contaminations when different environmental matrices were studied. Health risk index (HRI) was chronicled >1 for Cd in groundwater of industrial and residential sites, in the eggs found in the industrial site, and for Pb in groundwater of industrial and agricultural sites due to higher daily intake of metal, while all other HMs revealed HRI < 1 in all LUT.  相似文献
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