Bacillus halodurans菌株xynM基因的克隆、表达和序列分析

目的:用2株新分离鉴定的细菌克隆与最近源种(Bacillus halodurans C-125)木聚糖酶基因的同源序列,并对其进行序列分析。方法:根据已发表的近源种(C-125)的保守区序列设计引物,扩增出与其同源的木聚糖酶基因,进而用pQE31载体对该基因进行表达。同时对表达蛋白的三维空间结构进行网络模拟分析,对蛋白同源性进行比对分析。结果:克隆的木聚糖酶基因片段分别为1284bp和1236bp,而且该基因也成功表达;该蛋白是(α/α)6折叠构象,与C-125三者同属于一个分支上。结论:通过分析、表达蛋白编码外切-1,4-β-木聚糖酶,属于M家族。这该新分离菌株木聚糖酶的研究和应用提供了重要线索。     

Co-culture of rat luteal cells with islet cells enhances islet viability and revascularization

Islet cell transplantation is a major treatment strategy for type I diabetes, and has proven to be effective for maintaining glucose homeostasis. However, this treatment requires an extended period of immunosuppression to prevent rejection and recurrent transplantation to maintain function. Thus, to enhance the properties of transplanted islet cells, we examined the effect of the co-culture of luteal cells, which secrete progesterone, on islet cell viability, functionality, and revascularization. It was found that islet viability and functionality were higher in the co-cultured group than in single cultures of islets at 48 and 96 h, in parallel with increased progesterone and vascular endothelial growth factor (VEGF) secretion from luteal cells. In the co-culture groups, VEGF levels at 48 and 96 h and CD31 levels at 48 h were significantly higher than those in the islet groups (p?<?0.001 and p?<?0.05, respectively), and basic fibroblast growth factor (bFGF) levels were increased at 96 h (p?<?0.001). Thus, co-culture with luteal cells may increase islet vascularity by enhancing VEGF and bFGF levels for up to 96 h, which could help to markedly increase the pre-transplantation time to allow for effective immunosuppression therapy. This method may also promote islet cell viability and functionality. Progesterone and angiogenic factors secreted from luteal cells may be responsible for these positive effects.     

Timelessness in Sleep: Multidimensional Scope

Sleep and Biological Rhythms -     

The Dutch N-cascade in the European perspective

The Netherlands is "well known" for its nitrogen problems; it has one of the highest reactive nitrogen (Nr) emission densities in the world. It is a small country at the delta of several large European rivers. Ever since the industrial revolution, there has been a growing excess of nutrients and related emissions into the atmosphere (ammonia, nitrogen oxides and nitrous oxide) and into groundwater and surface water (nitrate), leading to a large range of cascading environmental impacts. Vehicular traffic, sewage and animal husbandry are the main sources of oxidized and reduced forms of Nr. This paper provides an overview of the origin and fate of nitrogen in the Netherlands, the various reported impacts of nitrogen, the Dutch and European policies to reduce nitrogen emissions and related impacts. In addition, ways are presented to go forward to potentially solve the problems in a European perspective. Solutions include the improvement of nitrogen efficiencies in different systems, technological options and education.     

Synemin Isoforms in Astroglial and Neuronal Cells from Human Central Nervous System

The intermediate filament (IF) synemin gene encodes three IF proteins (H 180, M 150, L 41 kDa) with overlapping distributions. Synemin M was present early with vimentin and nestin. Synemin H was found later in the nervous system and mesodermic derivatives concomitantly with angiogenesis and the migration of neural crest cells. Synemin L appeared later in neurons. A series of in vitro cell cultures were done to identify the linkage between synemin isoforms and specific cell types of the central nervous system (CNS). The neurons and glia from the brains of humans and rats were cultured and double immunostaining done with antibodies against the H/M or L synemin isoforms and neural cell types (βIII-tubulin or NeuN) or astrocyte intermediate filaments (GFAP or vimentin). In neurons of the CNS, synemin H/M were co-expressed with GFAP, vimentin or nestin in glial cells, whereas synemin L was found in neurons.     

Mitochondrial DNA evolution in the Montium-species subgroup of Drosophila

Mitochondrial DNA (mtDNA) restriction-site maps for six species (10 strains) of the Drosophila montium subgroup were established. A total of 50 restriction sites were mapped, corresponding to 1.67% of the mtDNA genome. On the basis of differences in the restriction sites, nucleotide divergence (delta) was calculated for each pair of species (strains), and phylogenetic trees were constructed by using distance- matrix and parsimony methods. Comparison of the resultant phylogenetic trees shows that the sibling species D. auraria and D. quadraria are closely related. At the other extreme, considerable divergence was observed between the two strains of D. serrata and between D. serrata and D. birchii, a finding that contrasts with their grouping within the same species complex. Nevertheless, our data indicate that these six oriental montium species are rather closely related.      

Ensiling whole-crop wheat and corn in large containers with Lactobacillus plantarum and Lactobacillus buchneri

The effect of applying Lactobacillus buchneri, alone or in combination with Lactobacillus plantarum, at ensiling, on the aerobic stability of wheat and corn silages was studied in 50-l plastic containers. Treatments comprised control (no additives), L. plantarum, L. buchneri and a combination of L. plantarum+L. buchneri. After 3 months of storage, the wheat silages treated with L. buchneri had higher acetic acid contents than the control or L. plantarum-treated silages, and were free of mold, whereas the top layers of the control or L. plantarum-treated silages were moldy. In an aerobic stability test the L. buchneri-treated silages were stable, whereas those treated with L. plantarum deteriorated. In the corn silages the effects of L. buchneri were not as clear and the top layer was moldy in all silages. However, L. buchneri also improved the aerobic stability of the corn silage, as indicated by lower yeast numbers, less CO₂ production and stable pH. It is concluded that L. buchneri has a potential as a silage additive that protects the silage upon aerobic exposure. The 50-l plastic containers can serve as an appropriate model to test silage additives before conducting full-scale farm experiments. Journal of Industrial Microbiology & Biotechnology (2002) 28, 7–11 DOI: 10.1038/sj/jim/7000207 Received 17 April 2001/ Accepted in revised form 25 August 2001     

Chemical Chaperone PBA Attenuates ER Stress and Upregulates SOCS3 Expression as a Regulator of Leptin Signaling

Biochemistry (Moscow) - Endoplasmic reticulum (ER) is very sensitive to the nutritional and energy states of the cells. Disruption of ER homeostasis leads to the accumulation of unfolded/misfolded...