Probing the regioselective C‐deuteriation of lithium enolates derived from 2‐methyl‐tetralone in the presence of substituted tertiary amines

Results are reported on the regioselective C‐deuteriation of 2‐methyl‐tetralone using a series of D‐sources and tertiary amines as potential mediators. The results presented further aid the understanding of kinetic deuteriation of both ‘base‐containing’ and ‘base‐free’ enolates. Copyright © 2006 John Wiley & Sons, Ltd.     

A critical assessment of allergen component-based in vitro diagnosis in cherry allergy across Europe

BACKGROUND: Food allergy to cherry occurs throughout Europe, typically with restricted oral reactions in the central and northern parts but with frequent systemic reactions in the Mediterranean region. Previous studies have demonstrated insufficient sensitivity of commercially available cherry extract reagents in the diagnosis of cherry allergy. OBJECTIVE: To assess the diagnostic performance of specific IgE tests based on recombinant cherry allergens in comparison with an extract-based assay and to skin prick test (SPT). A secondary objective was to analyse the frequency of systemic reactions in cherry-allergic subjects across Europe, including the largest population of LTP-sensitized subjects from central Europe studied to date. METHODS: A total of 186 subjects from central Europe and Spain were studied. Serum IgE was analysed with ImmunoCAP tests carrying rPru av 1, 3 and 4, combined and separately, and cherry extract. RESULTS: Among the central European cherry allergics, the mix of rPru av 1, 3 and 4 had a sensitivity of 95%, compared with 65% for cherry extract, and the IgE binding capacity of the recombinant mix was considerably higher. The sensitivity of the two tests was more comparable in the Spanish population, 95% and 86%, respectively. The recombinant allergen ImmunoCAP equalled SPT in terms of sensitivity and specificity. Consistent with previous reports, major geographic differences in sensitization pattern and prevalence of systemic reactions were found. A significantly higher rate of systemic reactions was found in Spanish patients sensitized to Pru av 3 whereas German patients sensitized to LTP only had oral allergy syndrome. CONCLUSIONS: The recombinant cherry allergen ImmunoCAP is a highly sensitive diagnostic tool, clearly superior to any diagnostic method based on cherry extract. Three cherry allergens are sufficient for detecting sensitization in 95% of cherry-allergic subjects. Systemic reactions are common in LTP-sensitized individuals but seem to require at least one additional causative factor.     

Gaseous homeostasis during low-flow anaesthesia

The object of this clinical study was to investigate the circle system gas homeostasis during low-flow anaesthesia using a technique designed to keep a constant inspired oxygen fraction of 0.30. Denitrogenation was adequately accomplished with mask preoxygenation, 10 l/min, for 1 min and an initial fresh gas flow of 5 l/min for 6 min after intubation. There was no need to wash out accumulated nitrogen at intervals, since the already low nitrogen concentration in the system tended to decrease after 1 h. The fresh gas flow of nitrous oxide to oxygen ratio and the inspiratory to end-expiratory oxygen concentration difference both reflected the uptake of nitrous oxide. The calculated rates of uptake of nitrous oxide, a subject of controversy, were in accordance with those found by Severinghaus and Barton & Nunn.     

人PD-L2基因克隆及其在大肠杆菌中的表达

目的 克隆人PD-L2基因并构建PD-L2胞外区的原核表达载体，在大肠杆菌中进行表达。方法 以RT-PCR方法从活化的人外周血单个核细胞总RNA中克隆PD-L2基因的cDNA，构建PD-L2胞外区的原核表达载体，在大肠杆菌BL21(ED3)中进行表达并鉴定。结果 克隆到PD-L2基因cDNA编码区全长序列，经DNA测序证明其与已报道的序列一致。进而构建了PD-L2胞外区的原核表达载体，并在大肠杆菌表达，免疫印迹分析表明在IPTG诱导后表达PD-L2胞外区蛋白，相对分子质量Mr为22000，与理论值大小相符。结论 成功克隆PD-L2基因，其胞外区蛋白在大肠杆菌中获得表达，为进一步研究PD-L2功能提供了条件。     

慢性乙型病毒性肝炎治疗新方法

就当前慢性乙肝治疗的新方法、新进展作一综述。     

转化生长因子β对人颈椎关节突关节软骨细胞基质金属蛋白酶13基因表达的调节作用及意义

目的 探讨转化生长因子β（TGF-β）对人的颈椎关节突关节透明软骨细胞基质金属蛋白酶13（MMP-13）基因表达的作用，旨在阐明颈椎退行性变的相关发生机理。方法 应用逆转录方法PCR及实时荧光定量方法，检测不同浓度TGF-β作用传代培养人的透明软骨细胞MMP-13mRNA的含量。另外3种不同浓度分别与10ng／ml IL-1β组成联合作用组，共计6个实验组及1个正常对照组。结果 正常对照组中透明软骨细胞仅见MMP-13mRNA扩增产物，实验组TGF-β1、10和100ng／ml作用12h后，MMP-13mRNA表达逐渐增强；而联合作用组中，随着TGF-β1浓度的升高，MMP-13mRNA表达逐渐降低，并且各组之间存在明显的差异（P〈0．05）。结论 TGF-β可按剂量依赖方式调节颈椎关节突关节软骨细胞MMP-13mRNA的表达。     

Seminal Fluid and the Expression of MHC Class I Antigens in the Placenta of the Rat

PROBLEM : To determine whether seminal fluid influences the expression of MHC class I antigens on the surface of basal trophoblast cells in the placenta of the rat. METHODS : Transfer of DA × DA embryos into a WF (allogeneic) or DA (syngeneic) recipient made pseudopregnant by hormonal treatment followed by mating with a vasectomized male (seminal fluid) or by mechanical stimulation (no seminal fluid). Antigen expression was determined by electron microscopic immunocytochemistry using the appropriate gold-labeled monoclonal antibodies. RESULTS : Seminal fluid did not affect the expression of MHC class I antigens on the surface of the basal trophoblast in either allogeneic or syngeneic matings. CONCLUSIONS : The suppression of the expression of paternal class I antigens on the surface of the basal trophoblast cells in allogeneic pregnancies most likely occurs at the genome level shortly after fertilization.     

Macular electroretinogram as a function of age of subjects

Macular and paramacular electroretinograms in response to two adjacent checks (6 deg/side), alternating at constant mean luminance, were recorded in 34 normal subjects ranging in age from 16 to 74 years. The macular electroretinogram declines progressively in amplitude with age (R = –0.42; P = 0.013). The amplitude ratio between macular and paramacular responses tends to be independent of age (R = -0.21; P = 0.22).Age-related changes in the macular electroretinogram shown in our study are consistent with previous anatomical and functional studies, which indicate a deterioration of photoreceptors beyond 20 years of age. These results suggest a possible use of this technique for future studies on macular degeneration.     

人碱性成纤维细胞生长因子基因在大肠杆菌中的克隆与表达

应用DNA重组技术将编码人碱性成纤维细胞生长因子（bbFGF）的基因克隆至原核高效表达质粒pBV_(221)的启动子下游。SDS-SAGE、ELISA和NTT活性监测结果表明:该重组质粒pBV-hbFGF在大肠杆菌DH5α中,经42℃诱导后,可表达出有较高生物活性的hbFGF。     

Magnetization Transfer and T2 Relaxation Components in Tissue

T₂ relaxation makes an important contribution to tissue contrast in magnetic resonance (MR) imaging. Many tissues are known to exhibit multicomponent T₂ relaxation that suggests some compartmental segregation of mobile protons on a T₂ timescale. Magnetization transfer (MT) is another relaxation mechanism that can be used to produce tissue contrast in MR imaging. The MT process depends strongly on water-macromolecular interactions. To investigate the relationship between multicomponent T₂ relaxation and the MT process, multiecho T₂ measurements have been combined with MT measurements for freshly excised samples of cardiac muscle, striated muscle, and white matter. For muscle, short T₂ components show greater MT than long T₂ components, consistent with the belief that they represent distinct water environments. For white matter, quantitative MT measurements were identical for the two major T₂ components, apparently because of exchange between the T₂ compartments on a timescale characteristic of the MT experiment. Implications for accurate modeling of MT in tissue and the use of MT for MR image contrast are discussed.