Evaluation of the antiparasitic activity of the chitosan-silver nanocomposites in the treatment of experimentally infested pigeons with Pseudolynchia canariensis

This study aimed to evaluate the efficacy of chitosan-silver nanocomposites in the treatment of experimentally infested pigeons with Pseudolynchia canariensis (P. canariensis) with evaluation of different immunological parameters before and after treatment. Therefore, fourteen birds were divided into 2 groups; group1(infested group including 12 birds) which subdivided into 6 sub-groups experimentally infested pigeons 2 pigeons each, and five group of them were treated with chitosan-silver nanocomposites and sub-group number 6 was treated with deltamethrin while, group 2 including two pigeons were kept as control negative ones. P. canariensis flies distributed under the wing and /or under the tail in infested group and these pigeons showed significantly lower RBCs and higher WBCs than that in non-infested pigeons. The cell mediated immune response against experimentally infested pigeons with P. canariensis was studied. P. canariensis infestation in pigeons have a negative impact on pigeon’s blood parameters, increase TNF-α and IL-1β cytokines levels. This study cleared out the role of P. canariensis in the induction of a case of oxidative stress indicated by high level of nitric oxide and malondialdehyde (MDA) with low antioxidant capacity in shape of reduced zinc concentration in the sera of experimentally infested pigeon. Chitosan-silver nanocomposite has a promising effect in the elimination of P. canariensis infestation in pigeons.     

Effect of ion channel blockers on germination of Bacillus megaterium spores

Abstract We surveyed 23 drugs that can interact with membrane components, such as ion channels, for their effect on spore germination. The results showed that triggering of spore germination was inhibited by specific calcium (Ca²⁺) potassium (K⁺) and sodium (Na⁺) channel blockers.     

The mode of action of thidiazuron: auxins,indoleamines, and ion channels in the regeneration of <Emphasis Type="Italic">Echinacea purpurea</Emphasis> L.

The biochemical mechanisms underlying thidiazuron (TDZ)-induced regeneration in plant cells have not been clearly elucidated. Exposure of leaf explants of Echinacea purpurea to a medium containing TDZ results in undifferentiated cell proliferation and differentiated growth as mixed shoot organogenesis and somatic embryogenesis. The current studies were undertaken to determine the potential roles of auxin, indoleamines, and ion signaling in the dedifferentiation and redifferentiation of plant cells. E. purpurea leaf explants were found to contain auxin and the related indoleamine neurotransmitters, melatonin, and serotonin. The levels of these endogenous indoleamines were increased by exposure to TDZ associated with the induction of regeneration. The auxin-transport inhibitor 2,3,5-triiodobenzoic acid and auxin action inhibitor, p-chlorophenoxyisobutyric acid decreased the TDZ-induced regeneration but increased concentrations of endogenous serotonin and melatonin. As well, inhibitors of calcium and sodium transport significantly reduced TDZ-induced morphogenesis while increasing endogenous indoleamine content. These data indicate that TDZ-induced regeneration is the manifestation of a metabolic cascade that includes an initial signaling event, accumulation, and transport of endogenous plant signals such as auxin and melatonin, a system of secondary messengers, and a concurrent stress response.     

Combined effect of sodium dodecyl sulfate and enzyme on waste activated sludge hydrolysis and acidification

The combined effect of sodium dodecyl sulfate (SDS) and enzyme system on hydrolysis and acidification of waste activated sludge (WAS) was investigated. The results showed that the combined system was more effective in the promotion of sludge hydrolysis than sole SDS and sole enzyme, and the SDS + mixed-enzymes (ME) system had better hydrolysis performance than SDS + single enzyme system. Compared with SDS + protease and SDS + amylase systems, the soluble protein concentration in SDS + ME system increased respectively by 20.0% and 44.4%, and the soluble carbohydrate concentration increased by 78.3% and 37.0%, respectively. During the WAS acidification stage, the SDS, ME and SDS + ME system could make the maximum short-chain fatty acids (SCFAs) concentration increased by 1.82 (6th day), 2.04 (5th day), 2.32 (7th day) times, respectively. The composition analysis of SCFAs produced in SDS + ME system indicated that acetic acid was the most prevalent product and propionic acid was the second one.     

BACE1 modulates filopodia-like protrusions induced by sodium channel beta4 subunit

Processing of APP by BACE1 plays a crucial role in the pathogenesis of Alzheimer disease (AD). Recently, the voltage-gated sodium channel (Na_v) β4 subunit (β4), an auxiliary subunit of Na_v that is supposed to serve as a cell adhesion molecule, has been identified as a substrate for BACE1. However, the biological consequence of BACE1 processing of β4 remains illusive. Here, we report the biological effects of β4 processing by BACE1. Overexpression of β4 in Neuro2a cells promoted neurite extension and increased the number of F-actin rich filopodia-like protrusions. While coexpression of BACE1 together with β4 further accelerated neurite extension, the number of filopodia-like protrusions was reduced. Overexpression of C-terminal fragment of β4 that was generated by BACE1 (β4-CTF) partially recapitulated the results obtained with BACE1 overexpression. These results suggest that the processing of β4 by BACE1 regulates neurite length and filopodia-like protrusion density in neurons.     

新型生物微胶囊体系的生物相容性研究

一种由硫酸纤维素钠(NaCS)和聚二丙烯基二甲基氯化铵(PDADMAC)形成的新型生物微胶囊已开始被用于生物物质的固定化。根据生物物质生长的情况,考察了这两种固定化材料各自对微生物和动物细胞生长的副作用及由NaCS和PDADMAC形成的微胶囊对微生物细胞生长的影响。实验结果表明这个新微胶囊体系具有良好的生物相容性。     

On-line stoichiometry and identification of metabolic state under dynamic process conditions

A method for the on-line calculation of conversion rates and yield coefficients under dynamic process conditions was developed. The method is based on cumulated mass balances using a moving average method. Elemental balances were used to test the measured cumulated quantities for gross errors and inappropriate stoichiometry definition followed by data reconciliation and estimation of non-measured conversion rates, using a bioprocess set-up including multiple on-line analysis techniques. The quantitative potential of the proposed method is demonstrated by executing transient experiments in aerobic cultures of Saccharomyces cerevisiae on glucose. Rates and yield coefficients could be consistently quantified in shift-up, shift-down, and accelerostat experiments. The method shows the capability to describe quantitatively transient changes in metabolism including uncoupling of catabolism and anabolism, also for the case when multiple components of metabolism are not measured. The validity of the experiment can be evaluated on-line. Additionally, the method detects with high sensitivity inappropriate stoichiometry definition, such as a change in state of metabolism. It was shown that concentration values can be misleading for the identification of the metabolic state. In contrast, the proposed method provides a clear picture of the metabolic state and new physiological regulations could be revealed. Hence, the novelty of the proposed method is the on-line availability of consistent stoichiometric coefficients allowing a significant speed up in strain characterization and bioprocess development using minimal knowledge of the metabolism. Additionally, it opens up the use of transient experiments for physiological studies.     

植物瞬间表达系统与功能基因组学研究

结构基因组学和功能基因组学的发展使特定植物基因组和转录组序列的获取更为方便和快捷。随之而来的是对各种基因和调控序列的功能注释,探索植物生长和发育的遗传机理。表达和调控表达是遗传物质的自身语言和动态属性,因此通过植物细胞内表达来分析目标基因和序列的表达和调控行为是功能分析的主要立足点。除创造转基因植株外,近几年来植物细胞瞬间表达系统得到了广泛的使用,与基因重排、病毒诱导基因沉默和RNA干扰等新兴技术的结合使其在植物功能基因组研究中扮演了越来越重要的角色。     

瞬时受体电位香草酸亚型1激活释放的P物质在小鼠急性心肌梗死后凋亡中的保护作用

瞬时受体电位香草酸亚型1 (transient receptor potential vanilloid 1, TRPV1)在心肌缺血激活后可传导心绞痛信号和释放P物质(substance P, SP).SP是速激肽家族成员之一,主要通过结合并激活神经激肽1 (neurokinin 1,NK1)受体发挥作用. TRPV1和SP在缺血性心脏病中对心功能的恢复和重塑有一定保护作用,但对心肌梗死后凋亡的作用及具体机制尚不明确.本研究用TRPV1基因敲除(TRPV1-/- )小鼠和野生型(wide type, WT)小鼠建立心肌梗死模型,并外源性给予SP和NK1受体拮抗剂RP67580,用TTC染色法观察梗死的面积,TUNEL法检测心肌细胞凋亡指数,Western印迹方法检测caspase-3、Bcl-2、Bax、p53的蛋白表达.结果发现,心肌梗死24 h后,TRPV1-/-小鼠比WT小鼠梗死面积更大,凋亡指数和caspase-3活性更高,Bcl-2/Bax和p53蛋白表达更低. SP预处理可以明显缩小TRPV1-/-小鼠梗死面积,降低凋亡指数、caspase-3活性和升高Bcl-2/Bax比值,而在WT小鼠中改善不明显.外源性给予RP67580,阻断SP与NK1受体结合后,与相应对照组相比,WT小鼠梗死面积和凋亡指数更大,caspase-3蛋白表达更高,Bcl-2/Bax比值更低;TRPV1-/-小鼠与相应对照组比较,凋亡指数和caspase-3表达升高,Bcl-2/Bax比值降低.研究结果表明,SP可能介导了TRPV1在急性心肌梗死后凋亡中的保护作用.