A rapid enzymatic assay for high-throughput screening of adenosine-producing strains

Adenosine is a major local regulator of tissue function and industrially useful as precursor for the production of medicinal nucleoside substances. High-throughput screening of adenosine overproducers is important for industrial microorganism breeding. An enzymatic assay of adenosine was developed by combined adenosine deaminase (ADA) with indophenol method. The ADA catalyzes the cleavage of adenosine to inosine and NH₃, the latter can be accurately determined by indophenol method. The assay system was optimized to deliver a good performance and could tolerate the addition of inorganic salts and many nutrition components to the assay mixtures. Adenosine could be accurately determined by this assay using 96-well microplates. Spike and recovery tests showed that this assay can accurately and reproducibly determine increases in adenosine in fermentation broth without any pretreatment to remove proteins and potentially interfering low-molecular-weight molecules. This assay was also applied to high-throughput screening for high adenosine-producing strains. The high selectivity and accuracy of the ADA assay provides rapid and high-throughput analysis of adenosine in large numbers of samples.     

Adaptive Evolution of Defense Ability Leads to Diversification of Prey Species

In this paper, by using the adaptive dynamics approach, we investigate how the adaptive evolution of defense ability promotes the diversity of prey species in an initial one-prey–two-predator community. We assume that the prey species can evolve to a safer strategy such that it can reduce the predation risk, but a prey with a high defense ability for one predator may have a low defense ability for the other and vice versa. First, by using the method of critical function analysis, we find that if the trade-off is convex in the vicinity of the evolutionarily singular strategy, then this singular strategy is a continuously stable strategy. However, if the trade-off is weakly concave near the singular strategy and the competition between the two predators is relatively weak, then the singular strategy may be an evolutionary branching point. Second, we find that after the branching has occurred in the prey strategy, if the trade-off curve is globally concave, then the prey species might eventually evolve into two specialists, each caught by only one predator species. However, if the trade-off curve is convex–concave–convex, the prey species might eventually branch into two partial specialists, each being caught by both of the two predators and they can stably coexist on the much longer evolutionary timescale.     

Significance of consensus CYC‐binding sites found in the promoters of both ChCYC and ChRAD genes in Chirita heterotricha (Gesneriaceae)

Abstract CYC‐like genes are widely conserved in controlling floral dorsoventral asymmetry (zygomorphy) through persistent expression in corresponding domains in core eudicots. To understand how CYC‐like gene expression is maintained during flower development, we selected Chirita heterotricha as a material and isolated the promoter sequences of the ChCYC1C and ChCYC1D genes, homologs of CYC, by inverse polymerase chain reaction. Further promoter analyses led to the identification of a putative cis‐regulatory element in each promoter matching the consensus DNA binding site for Antirrhinum CYC protein: GGCCCCTC at ?165 for ChCYC1C, and GGCCCCCC at ?163 for ChCYC1D. This indicates that both the ChCYC1C and ChCYC1D genes have probably evolved autoregulatory loops to sustain their expression in developing flowers. We also isolated the coding and promoter sequences of the ChRAD gene, a homolog of Antirrhinum RAD. Promoter analysis showed that the ChRAD gene promoter also contained a putative CYC‐binding site (GGCCCAC at ?134). Therefore, ChRAD is likely a direct target of the ChCYC1 genes, which is similar to Antirrhinum RAD. These results imply that the establishment of floral zygomorphy in Chirita may have been achieved by the evolution of an autoregulatory loop for CYC‐like genes, which was probably accompanied by simultaneous co‐option of the RAD‐like gene into their regulatory network.     

Increased expression of costimulatory markers CD134 and CD80 on interleukin-17 producing T cells in patients with systemic lupus erythematosus

Introduction  

There is growing evidence that interleukin 17 (IL-17) producing T cells are involved in the pathogenesis of systemic lupus erythematosus (SLE). Previous studies showed that increased percentages of T-cell subsets expressing the costimulatory molecules CD80 and CD134 are associated with disease activity and renal involvement in SLE. The aim of this study was to investigate the distribution and phenotypical characteristics of IL-17 producing T-cells in SLE, in particular in patients with lupus nephritis, with emphasis on the expression of CD80 and CD134.     

Molecular and nanoparticle postcolumn reagents for assay of low-molecular-mass biothiols using high-performance liquid chromatography

Determination of low-molecular-mass (LMM) biothiols in biological matrixes is of importance in the studies of their related bio-processes and for the clinical diagnostics of a variety of diseases. Standard method for the assay of the small biothiols is in demand. Postcolumn techniques used in high-performance liquid chromatography (HPLC) allow automation of the derivatization step and, therefore, are suitable for standardization of HPLC analysis. This paper gives an overview of the existing reaction systems useful for the postcolumn assay of the LMM biothiol molecules in conjunction with HPLC. The postcolumn reagents are classified by the types of their reactions with thiol-containing compounds. The chemical reactivity and selectivity as well as the spectroscopic characteristics of the postcolumn reagents have been addressed. The emerging strategies of using nanoparticles as thiol-reactive reagents and their applications in postcolumn detection of the LMM biothiols have also been discussed in detail.     

Effects of Alzheimer's amyloid-beta and tau protein on mitochondrial function -- role of glucose metabolism and insulin signalling

Alzheimer's disease (AD) is the most frequent form of dementia among the elderly and is characterized by neuropathological hallmarks of extracellular amyloid-beta (Abeta) plaques and intracellular neurofibrillary tangles composed of abnormally hyperphosphorylated microtubular protein tau in the brains of AD patients. Of note, current data illustrate a complex interplay between the amyloid and tau pathology during the course of the disease. We hypothesize a direct impact of abnormally phosphorylated tau and Abeta on proteins/enzymes involved in metabolism, respiratory chain function and cellular detoxification. Probably at the level of mitochondria, both Alzheimer proteins exhibit synergistic effects finally leading to/accelerating neurodegenerative mechanisms. Moreover, accumulating evidence that mitochondria failure, reduced glucose utilization and deficient energy metabolism occur already very early in the course of the disease suggests a role of impaired insulin signalling in the pathogenesis of AD. Thus, this review addresses also the question if mitochondrial dysfunction may represent a link between diabetes and AD.     

重金属污染土壤稳定/固化修复技术研究进展

修复重金属污染土壤一直是国际上的难点和热点研究课题.目前常用的污染场地修复技术主要包括挖掘、稳定/固化(solidification/stabilization,S/S)、化学淋洗、气提、热处理、生物修复等.本文在参考美国环境保护署(EPA)、英国环境署的S/S技术规范、国内外发明专利基础上,对S/S的概念、国内外发展现状及今后的发展方向进行了系统论述.固定化技术通过把污染物囊封入惰性基材中,或在污染物外面加上低渗透性的材料,来减少污染物暴露的淋滤面积以达到限制污染物迁移的目的.稳定化技术是从改变污染物的有效性出发,将污染物转化为不易溶解、迁移能力或毒性更小的形式.S/S技术包括:水泥固化、石灰火山灰固化、塑性材料包容固化、玻璃化技术、药剂稳定化.在稳定化技术中,加入药剂的目的是改变土壤的物理、化学性质,通过pH控制技术、氧化还原电势技术、沉淀技术、吸附技术、离子交换技术等改变重金属在土壤中的存在状态,从而降低其生物有效性和迁移性.本文还论述了S/S修复效果评价方法,并指出需加强S/S技术中的分子键合技术、土聚合物以及我国的S/S技术导则制定等工作.     

Baseline predictors of response and discontinuation of tumor necrosis factor-alpha blocking therapy in ankylosing spondylitis: a prospective longitudinal observational cohort study

Introduction  

Identifying ankylosing spondylitis (AS) patients who are likely to benefit from tumor necrosis factor-alpha (TNF-α) blocking therapy is important, especially in view of the costs and potential side effects of these agents. Recently, the AS Disease Activity Score (ASDAS) has been developed to assess both subjective and objective aspects of AS disease activity. However, data about the predictive value of the ASDAS with respect to clinical response to TNF-α blocking therapy are lacking. The aim of the present study was to identify baseline predictors of response and discontinuation of TNF-α blocking therapy in AS patients in daily clinical practice.