AtNHX8, a member of the monovalent cation: proton antiporter-1 family in Arabidopsis thaliana, encodes a putative Li/H antiporter

The Arabidopsis monovalent cation:proton antiporter-1 (CPA1) family includes eight members, AtNHX1-8. AtNHX1 and AtNHX7/SOS1 have been well characterized as tonoplast and plasma membrane Na+/H+ antiporters, respectively. The proteins AtNHX2-6 have been phylogenetically linked to AtNHX1, while AtNHX8 appears to be related to AtNHX7/SOS1. Here we report functional characterization of AtNHX8. AtNHX8 T-DNA insertion mutants are hypersensitive to lithium ions (Li+) relative to wild-type plants, but not to the other metal ions such as sodium (Na+), potassium (K+) and caesium (Cs+). AtNHX8 overexpression in a triple-deletion yeast mutant AXT3 that exhibits defective Na+/Li+ transport specifically suppresses sensitivity to Li+, but does not affect Na+ sensitivity. Likewise, AtNHX8 overexpression complemented sensitivity to Li+, but not Na+, in sos1-1 mutant seedlings, and increased Li+ tolerance of both the sos1-1 mutant and wild-type seedlings. Results of Li+ and K+ measurement of loss-of-function and gain-of-function mutants indicate that AtNHX8 may be responsible for Li+ extrusion, and may be able to maintain K+ acquisition and intracellular ion homeostasis. Subcellular localization of the AtNHX8-enhanced green fluorescent protein (EGFP) fusion protein suggested that AtNHX8 protein is targeted to the plasma membrane. Taken together, our findings suggest that AtNHX8 encodes a putative plasma membrane Li+/H+ antiporter that functions in Li detoxification and ion homeostasis in Arabidopsis.     

Urothelial progenitor cells: regional differences in the rat bladder

OBJECTIVES: Because the trigone is a unique region in the caudal bladder with a higher risk of neoplasia, we hypothesized that this area would have a high proportion of progenitor cells. As yet there is no marker nor methodology to specifically isolate urothelial stem cells, and thus demonstrate multi-potential differentiation and self-renewal. Here, our goal was to evaluate the distribution of progenitor cells that carry two general major attributes of stem cells: clonogenicity and proliferative capacity. MATERIALS AND METHODS: The bladders of Fisher rats were divided into caudal and cephalic segments and primary cultures were established from the harvested urothelial cells. RESULTS: We found that colony-forming efficiency was almost 2-fold higher for cells from the caudal bladder compared to the cephalic bladder. Doubling time was significantly faster for cells harvested from the caudal bladder at initial plating. This suggested that the caudal bladder harbours a higher density of urothelial progenitor cells. With passage to p4, the differences between the upper and lower bladder were lost, suggesting selection of proliferative cells with serial passage. Based on Ki-67 staining, there was no geographical difference in cell proliferation under normal homeostatic in vivo conditions. CONCLUSIONS: These results demonstrate geographical sequestration of urothelial progenitor cells to the area of the bladder that encompasses the bladder neck and trigone, which may be a factor in pathological disparities between the trigone and remaining bladder.     

Oxazolidinones as novel human CCR8 antagonists

High-throughput screening of the corporate compound collection led to the discovery of a novel series of N-substituted-5-aryl-oxazolidinones as potent human CCR8 antagonists. The synthesis, structure-activity relationships, and optimization of the series that led to the identification of SB-649701 (1a), are described.     

Synthesis and biophysical evaluation of minor-groove binding C-terminus modified pyrrole and imidazole triamide analogs of distamycin

Five polyamide derivatives with rationally modified C-terminus moieties were synthesized and their DNA binding specificity and affinity determined. A convergent approach was employed to synthesize polyamides containing an alkylaminopiperazine (4 and 5), a truncated piperazine (6), or an alkyldiamino-C-terminus moiety (7 and 8) with two specific objectives: to investigate the effects of number of potential cationic centers and steric bulk at the C-terminus. CD studies confirmed that compounds 4, 5, 7, and 8 bind in the minor groove of DNA. The alkylpiperazine containing compounds (4 and 5) showed only moderate binding to DNA with DeltaT(m) values of 2.8 and 8.3 degrees C with their cognate sequence, respectively. The alkyldiamino compounds (7 and 8) were more impressive producing a DeltaT(m) of >17 and >22 degrees C, respectively. Compound 6 (truncated piperazine) did not stabilize its cognate DNA sequence. Footprints were observed for all compounds (except compound 6) with their cognate DNA sequence using DNase I footprinting, with compound 7 producing a footprint of 0.1 microM at the expected 5'-ACGCGT-3' site. SPR analysis of compound 7 binding to 5'-ACGCGT-3', 5'-ACCGGT-3', and 5'-AAATTT-3' produced binding affinities of 2.2x10(6), 3.3x10(5), and 1x10(5)M(-1), respectively, indicating a preference for its cognate sequence of 5'-ACGCGT-3'. These results are in good agreement with the footprinting data. The results indicate that steric crowding at the C-terminus is important with respect to binding. However, the number of cationic centers within the molecule may also play a role. The alkyldiamino-containing compounds (7 and 8) warrant further investigation in the field of polyamide research.     

猪冠状动脉前降支结扎位点和左室功能的线性回归

目的探讨猪冠状动脉前降支(LAD)结扎百分位点和心梗体积、左室射血分数的关系,以期指导研究者能够根据急性心肌梗死模型的心功能要求选择合适的LAD结扎百分位点。方法将47只小型猪开胸结扎心脏LAD中远段约30%~75%的不同百分位点,分别于术前、术后1 h心脏超声检查左室射血分数(LVEF),术后3 d进行常规冠状动脉造影,4周处死测量前降支结扎位点和梗死体积,最后用简单直线回归模型分析LAD结扎百分位点和心梗体积、左室射血分数回归方程和相关系数。结果47例动物手术过程中死亡8只,剩余39只存活动物冠状动脉造影均显示LAD中远段结扎部位处完全闭塞,表明手术成功。LAD结扎百分位点和术后1 h LVEF、术后1 hLVEF下降值、梗死心肌体积均明显相关(相关系数r分别为0.87、0.78和0.90,P均<0.001),其回归方程分别为:术后LVEF(%)=65.88-0.55x结扎百分位点;术后LVEF下降值(%)=0.12 0.59x结扎百分位点;心肌梗死体积(%)=0.53x结扎百分位点-5.43。结论猪LAD结扎百分位点和术后左室功能、梗死心肌体积均存在显著的相关性,可根据实验目的和对心功能的要求选择合适的结扎百分位点。     

野生湖南山核桃的营养成分研究

对野生湖南山核桃果仁的油脂及其组分、总糖、蛋白质及其氨基酸组成、维生素E、维生素B1、钙、铁、锌、铜、钼等元素含量进行分析.果仁中粗脂肪、总糖、粗蛋白质、维生素E、维生素B1的含量分别为56.57%、3.51%、8.18%、3.06 mg/100 g和1.19 mg/100 g;钙、铁、锌、铜、钼元素含量的含量分别为114.6 mg/100 g、3.26 mg/100g、5.14 mg/100g、1.69 mg/100g和0.12 mg/100g.果仁的脂肪主要由软脂酸、油酸,亚油酸、亚麻酸、花生四烯酸组成,其含量分别为6.41%,71.80%,19.28%,1.82%和0.69%;果仁中蛋白质氨基酸有16种,其中9种人体必需氨基酸都含有.     

Fluocinolone acetonide intravitreal sustained release device--a new addition to the armamentarium of uveitic management

Uveitis is a potentially sight-threatening inflammatory eye disease caused by multiple infectious and non-infectious etiologies for which the standard of care involves corticosteroids or various immunomodulary therapy (IMT) drugs. These available treatments, although effective, may cause significant morbidity and sometimes mortality in uveitis patients due to their toxic side-effects and the necessity of long-term therapy to prevent recurrences. In order to avoid the systemic toxicity ofcorticosteroids and IMT or the repeated injections of local steroids necessary to control ocular inflammation, and to prevent development of cumulative damage resulting from recurrent episodes of inflammation, researchers have developed a number of local corticosteroid sustained-release devices that can be implanted directly into the vitreous of the eye, at the site of the inflammatory disease. Preliminary studies of such a device, the fluocinolone acetonide (Retisert) implant, have shown significant reductions in the number of inflammatory episodes and decreased reliance on systemic corticosteroids or other IMT. This review explores the current research evaluating the fluocinolone sustained-release intravitreal implant in the treatment of posterior uveitis and the implications for its future use on a wider scale.     

Immunological roles of Pasteurella multocida toxin (PMT) using a PMT mutant strain

The immunological role of the Pasteurella multocida toxin (PMT) in mice was examined using a PMT mutant strain. After a nasal inoculation, the mutant strain failed to induce interstitial pneumonia. Moreover, PMT had no significant effect on the populations of CD4+, CD8+, CD3+, and CD19+ immunocytes in blood or on the populations of CD4+ and CD8+ splenocytes (P<0.01). However, there was a significant increase in the total number of cells in the BAL samples obtained from the wild-type P. multocida-inoculated mice. On the other hand, the level of IL-1 expression decreased when the macrophages from the bronchio-alveolar lavage were stimulated with PMT. Overall, PMT appears to play some role (stimulating and/or inhibiting) in the immunological responses but further studies will be required to confirm this.     

Expression of EuNOD-ARP1 encoding auxin-repressed protein homolog is upregulated by auxin and localized to the fixation zone in root nodules of Elaeagnus umbellata

Root nodule formation is controlled by plant hormones such as auxin. Auxin-repressed protein (ARP) genes have been identified in various plant species but their functions are not clear. We have isolated a full-length cDNA clone (EuNOD-ARP1) showing high sequence homology to previously identified ARP genes from root nodules of Elaeagnus umbellata. Genomic Southern hybridization showed that there are at least four ARP-related genes in the genome of E. umbellata. The cDNA clone encodes a polypeptide of 120 amino acid residues with no signal peptide or organelle-targeting signals, indicating that it is a cytosolic protein. Its cytosolic location was confirmed using Arabidopsis protoplasts expressing a EuNOD-ARP1:smGFP fusion protein. Northern hybridization showed that EuNOD-ARP1 expression was higher in root nodules than in leaves or uninoculated roots. Unlike the ARP genes of strawberry and black locust, which are negatively regulated by exogenous auxin, EuNOD-ARP1 expression is induced by auxin in leaf tissue of E. umbellata. In situ hybridization revealed that EuNOD-ARP1 is mainly expressed in the fixation zone of root nodules.     

Chitinophaga soli sp. nov. and Chitinophaga terrae sp. nov., isolated from soil of a ginseng field in Pocheon Province, Korea

Two novel strains of the Cytophaga-Flexibacter-Bacteroides (CFB) group, designated Gsoil 219" and Gsoil 2381, were isolated from soil of a ginseng field of Pocheon Province in Korea. Both strains were Gram-negative, aerobic, nonmotile, nonspore-forming, and rod-shaped. Phylogenetic analysis based on 16S rRNA gene sequences indicated that both isolates belong to the genus Chitinophaga but were clearly separated from established species of this genus. The sequence similarities between strain Gsoil 219T and type strains of the established species and between strain Gsoil 238T and type strains of the established species ranged from 91.4 to 94.7% and 91.6 to 94.2%, respectively. Phenotypic and chemotaxonomic data (major menaquinone, MK-7; major fatty acids, iso-C15:0 and C(16:1) omega5c; major hydroxy fatty acid, iso-C(17:0) 3-OH; major polyamine, homospermidine) supported the affiliation of both strains Gsoil 219T and Gsoil 238T to the genus Chitinophaga. Furthermore, the results of physiological and biochemical tests allowed genotypic and phenotypic differentiation of both strains from the other validated Chitinophaga species. Therefore, the two isolates represent two novel species, for which the name Chitinophaga soli sp. nov. (type strain, Gsoil 219T=KCTC 12650T=DSM 18093T) and Chitinophaga terrae sp. nov. (type strain, Gsoil 238T=KCTC 12651T=DSM 18078T) are proposed.