Decomposition time,chemical traits and climatic factors determine litter-mixing effects on decomposition in an alpine steppe ecosystem in Northern Tibet

Plant and Soil - In the context of rapid species diversity loss, whether and how species diversity affects litter decomposition in alpine ecosystems remain unclear. Here, we aimed to assess the...     

Human Equilibrative Nucleoside Transporter-3 (hENT3) Spectrum Disorder Mutations Impair Nucleoside Transport,Protein Localization,and Stability

Accumulating evidence reveals that sole mutations in hENT3 cause a spectrum of human genetic disorders. Among these include H syndrome, characterized by scleroderma, hyperpigmentation, hypertrichosis, hepatomegaly, cardiac abnormalities and musculoskeletal deformities, pigmented hypertrichotic dermatosis with insulin-dependent diabetes syndrome, characterized by autoantibody-negative diabetes mellitus and skin deformities, familial Rosai-Dorfman disease, characterized by short stature, familial histiocytosis and sinus histiocytosis with massive lymphadenopathy (SHML), characterized by severe tissue infiltration of immune cells and swollen lymph nodes. hENT3 spectrum disorders share a common mutation and share overlapping clinical manifestations that display many intriguing resemblances to mitochondrial and lysosomal disorders. Although earlier studies identify hENT3 as a mitochondrial and a lysosomal nucleoside transporter, the precise connections between hENT3 and the pathophysiology of these disorders remain unresolved. In this study, we performed functional and biochemical characterization of these mutations in hENT3. We report severe reductions/losses of hENT3 nucleoside transport functions of hENT3 syndrome mutants. In addition to transport alterations, we provide evidence for possible loss of hENT3 functions in all H and pigmented hypertrichotic dermatosis with insulin-dependent diabetes syndromes due to either mistrafficking or altered stability of mutant hENT3 proteins.     

Effects of neutrophil adherence on the characteristics of receptors for tumor necrosis factor-alpha.

Human recombinant [125I]TNF-alpha was incubated with non-adherent human neutrophils, cells adherent to fibronectin-coated plastic, or adherent cells scraped into suspension (post-adherent). Binding of TNF to all cells increased with doses of added TNF but adherent cells bound little TNF. Binding of TNF by post-adherent cells was greater than when adherent, but still significantly less than that of non-adhered neutrophils, suggesting that TNF receptors were relocated on the adherent surface of neutrophils. Scatchard analysis showed that adherent cells expressed significantly fewer TNF receptors, but of higher affinity, than non-adherent cells. The results suggest that altered expression of TNF receptors might contribute to the differential effects of TNF on adherent and non-adherent neutrophils.     

Comparative Microdistribution of the Activity of Catecholamine-Synthesizing Enzymes in Horizontal Sections of the Rat Lower Brainstem

The activities of the three major catecholamine-synthesizing enzymes were determined in brain tissue pellets dissected from 500-micrometers thick horizontal sections of rat lower brainstem. The rostrocaudal distributions of the three enzymatic activities were generally not parallel, suggesting differences in the respective localization of the noradrenergic and adrenergic neurons. The difference was most important in the A2-C2 region where the maximal activity of phenylethanolamine-N-methyltransferase (EC 2.1.1.28) was located 1.5 mm more rostrally than the maximal activities of the tyrosine hydroxylase (EC 1.14.16.2) and dopamine beta-hydroxylase (EC1.14.17.1). This result indicates that a more specific dissection of the adrenergic and noradrenergic neurons could be performed in the A2-C2 area of the rat brainstem.     

Development and validation of PCR primers to assess the diversity of Clostridium spp. in cheese by temporal temperature gradient gel electrophoresis

A nested-PCR temporal temperature gradient gel electrophoresis (TTGE) approach was developed for the detection of bacteria belonging to phylogenetic cluster I of the genus Clostridium (the largest clostridial group, which represents 25% of the currently cultured clostridial species) in cheese suspected of late blowing. Primers were designed based on the 16S rRNA gene sequence, and the specificity was confirmed in PCRs performed with DNAs from cluster I and non-cluster I species as the templates. TTGE profiles of the PCR products, comprising the V5-V6 region of the 16S rRNA gene, allowed us to distinguish the majority of cluster I species. PCR-TTGE was applied to analyze commercial cheeses with defects. All cheeses gave a signal after nested PCR, and on the basis of band comigration with TTGE profiles of reference strains, all the bands could be assigned to a clostridial species. The direct identification of Clostridium spp. was confirmed by sequencing of excised bands. C. tyrobutyricum and C. beijerinckii contaminated 15 and 14 of the 20 cheese samples tested, respectively, and C. butyricum and C. sporogenes were detected in one cheese sample. Most-probable-number counts and volatile fatty acid were determined for comparison purposes. Results obtained were in agreement, but only two species, C. tyrobutyricum and C. sporogenes, could be isolated by the plating method. In all cheeses with a high amount of butyric acid (>100 mg/100 g), the presence of C. tyrobutyricum DNA was confirmed by PCR-TTGE, suggesting the involvement of this species in butyric acid fermentation. These results demonstrated the efficacy of the PCR-TTGE method to identify Clostridium in cheeses. The sensitivity of the method was estimated to be 100 CFU/g.     

Selection of a suitable plant for phytoremediation in mining artisanal zones

A study was undertaken with the aim of identifying a suitable plant for the phytoremediation of metal-polluted soil from an artisanal mining area in Ecuador. Three zones including a natural zone (NZ), abandoned zone (AZ) and intensively mined zone (IZ) were selected. Three common native plants grown in the three zones were identified and collected, including Miconia zamorensis, Axonopus compressus and Erato polymnioides. The percentage of arbuscular mycorrhizal colonization that benefits their own survival in polluted soil was analyzed in the root samples of these candidate species. Analysis of the soils and plants collected from the different zones showed that the concentrations of Pb, Zn, Cu and Cd were comparatively lower in the NZ, higher in the AZ and IZ, and highest in the AZ for all the metals. The concentration of all these metals in plant tissues was the highest in E. polymnioides. The data analysis including the metal accumulation index, bioconcentration factor and translocation factor strongly identified E. polymnioides as a hyperaccumulator plant suitable for phytoremediation.     

藏鸡心脏高海拔低氧适应相关酶的研究

目的：研究藏鸡心脏对高海拔低氧适应性的生理特征。方法：本研究将藏鸡、矮小隐性白和寿光鸡分别饲养在低海拔和高海拔环境,测定10周龄时心脏重量、心肌乳酸（LA）和乳酸脱氢酶（LDH）、琥珀酸脱氢酶（SDH）活性。结果：结果显示藏鸡在高海拔环境中,心脏相对重量未明显增加,心肌LA低于对照鸡,LDH与对照鸡差异不显著,而SDH活性明显高于对照鸡。结论：结果说明了藏鸡对高海拔低氧环境的适应,不是通过增加心脏器官的重量,也不是通过提高无氧代谢的水平,较高的SDH活力对藏鸡心肌低氧适应有一定的意义。SDH是藏鸡适应低氧的一种标志酶。