556例多发伤患者的急诊救治临床分析

目的探讨多发伤患者的救治策略。方法回顾分析我科2000年1月至2008年5月急诊抢救的556例多发伤患者的临床资料。结果 16例患者经抢救无效死亡,死亡率2.88%;其余患者均经紧急抢救及行必要实验室检查,病情稳定,好转率达97.12%。平均抢救时间为(1.37±1.05)h。结论强化多发伤的急诊科早期救治,树立创伤急救"黄金1 h"观念,是提高多发伤患者生存率及降低死亡率的关键。     

Determination of absolute configuration in 4‐aryl‐3,4‐dihydro‐2(1H)‐pyrimidones by high performance liquid chromatography and CD spectroscopy

The absolute configuration of three 4‐aryl‐3,4‐dihydro‐2(1H)‐pyrimidones (Biginelli compounds, DHPMs) was established by comparison of the typical circular dichroism (CD) spectra of individual enantiomers with reference samples of known absolute configuration. The enantiomers were obtained by semipreparative separation of racemic mixtures on a Chiralcel OD‐H chiral stationary phase. The method was used to establish the enantiopreference of various lipases in biocatalytic kinetic resolution experiments employing activated DHPM esters. Chirality 11:659–662, 1999. © 1999 Wiley‐Liss, Inc.     

Maintaining nitric oxide-induced airway relaxation with superoxide dismutase

BACKGROUND: We have previously shown that the protective effect of inhaled nitric oxide (iNO) against methacholine-induced bronchoconstriction is negated in airways subjected to hyperosmotic stress. In this study, hypothesizing that the impaired efficiency of iNO was caused by release of reactive oxygen radicals, we examined the effect of the radical scavenging enzyme superoxide dismutase (SOD). METHODS: Hemodynamic and respiratory measurements were performed on anesthetized rabbits after (1) inhalation of methacholine (MCh), (2) iNO (80ppm), followed by MCh, (3) inhalation of hypertonic saline (HS), followed by iNO and MCh and (4) pre-treatment with inhalation of SOD, followed by HS, iNO and MCh. We analyzed plasma for a marker of oxidative stress, 8-iso-prostaglandin (PG)F(2alpha) and for a marker of activation of COX-mediated inflammatory cascades, PGF(2alpha) metabolite. RESULTS: Pre-treatment with SOD restored the bronchoprotective response to iNO in hyperosmotic airways. No direct effect was seen by SOD treatment on levels of 8-iso-PGF(2alpha), but this marker of oxidative stress correlated positively with increased bronchoconstriction. Hyperosmotic challenge elevated levels of PGF(2alpha) metabolite, and pre-treatment with SOD protected against this activation of the inflammatory cascade. CONCLUSION: SOD pre-treatment restores the relaxant effects of iNO in hyperosmotically challenged airways by attenuating oxidative stress and activation of COX-mediated inflammatory cascades.     

Effect of mycorrhization on the isoflavone content and the phytoestrogen activity of red clover

Red clover, known for its estrogenic activity due to its isoflavones content (biochanin A, genistein, daidzein and formononetin), was inoculated with the arbuscular mycorrhizal fungus Glomus mosseae. Once the symbiotic fungus was well established, plants were harvested and we determined the root and shoot dry weight as well as the P-content. In roots and leaves the levels of biochanin A, genistein, daidzein and formononetin were quantified by reversed-phase HPLC and the estrogenic activity of the leaves was measured by a transactivation assay using a yeast two-plasmid system. Mycorrhization increased the levels of biochanin A in the root and the shoot and reduced the levels of genistein in the shoot of red clover. The levels of the other isoflavones were not affected. The shoot biomass of mycorrhizal plants more than doubled compared with non-mycorrhizal control plants, and this growth-stimulating effect of arbuscular mycorrhiza did not affect the estrogenic activity of red clover. In a control P treatment, the biomass of red clover was greatly enhanced. However, the estrogenic activity was reduced. These results suggest that, in contrast to an enhanced shoot biomass production after P application with a reduced estrogenic activity, with arbuscular mycorrhiza the shoot biomass of red clover can be enhanced without a negative effect on estrogenic activity.     

Tet-system for the regulation of gene expression during embryonic development

The ability to control gene expression in a temporal and spatial manner provides a new tool for the study of mammalian gene function particularly during development and oncogenesis. In this study the suitability of the tet-system for investigating embryogenesis was tested in detail. The tTA ^CMV (M1) and rTA ^CMV-3 (reverse Tc-controlled transactivator) transgenic mice were bred with NZL-2 bi-reporter mice containing the vector with a tTA/rTA responsive bidirectional promoter that allows simultaneous regulation of expression of two reporter genes encoding luciferase and -galactosidase. In both cases reporter genes were found to be expressed in a wide spectrum of tissues of double transgenic embryos and adult mice. The earliest expression was detected in tTA ^CMV (M1)/NZL-2 embryos at embryonic day 10.5 (E10.5) and rTA ^CMV -3/NZL-2 embryos at E13.5. Doxycycline abolished -gal expression in tTA ^CMV (M1)/NZL-2 but induced it in rTA ^CMV -3/NZL-2 embryos including late stages of embryogenesis. The tTA and rtTA transactivators thus revealed a partially complementary mode of action during second half of embryonic development. These experiments demonstrated that both Tet regulatory systems function during embryonic development. We conclude that the Tet systems allows regulation of gene expression during embryonic development and that double reporter animals like the NZL-2 mice are useful tools for the characterization of newly generated tet transactivator lines expressing tTA (or rtTA) in embryonic as well as in adult tissues.     

Lessons from the stem cell proteome

The proteome of a cell is a molecular fingerprint directly relating to the gene expression snapshot profile at a certain point of time or developmental stage. Monitoring the expansion and the differentiation state of stem cells by proteomic means seems therefore a very attractive method for diagnostic as well as for therapeutic purposes. We have investigated the protein expression patterns of umbilical cord blood-derived CD34+/AC133+ cells in order to obtain a most comprehensive view of the stem cell proteome. For this purpose, we have applied 2-D gel electrophoresis and 2-D chromatography for most efficient protein/peptide separation and characterisation. The proteins were identified after tryptic digestion by nano-HPLC coupled directly to an ion trap mass spectrometer. An extensive bioinformatic analysis of the protein obtained revealed a dynamic stem cell proteome. This means that the heterogeneity of protein expression patterns obtained from different stem cell preparations refers to a limited set of stem cell-specific house keeping proteins as well as to a large number of proteins which depend on (marginal) stimuli from the environment. Since those are difficult to standardise, snapshot views of the stem cell proteome reflect not only stem cell-intrinsic metabolism but also the strong influence of the sample history on protein expression patterns.     

Plant diversity positively affects short‐term soil carbon storage in experimental grasslands

Increasing atmospheric CO₂ concentration and related climate change have stimulated much interest in the potential of soils to sequester carbon. In ‘The Jena Experiment’, a managed grassland experiment on a former agricultural field, we investigated the link between plant diversity and soil carbon storage. The biodiversity gradient ranged from one to 60 species belonging to four functional groups. Stratified soil samples were taken to 30 cm depth from 86 plots in 2002, 2004 and 2006, and organic carbon contents were determined. Soil organic carbon stocks in 0–30 cm decreased from 7.3 kg C m^?2 in 2002 to 6.9 kg C m^?2 in 2004, but had recovered to 7.8 kg C m^?2 by 2006. During the first 2 years, carbon storage was limited to the top 5 cm of soil while below 10 cm depth, carbon was lost probably as short‐term effect of the land use change. After 4 years, carbon stocks significantly increased within the top 20 cm. More importantly, carbon storage significantly increased with sown species richness (log‐transformed) in all depth segments and even carbon losses were significantly smaller with higher species richness. Although increasing species diversity increased root biomass production, statistical analyses revealed that species diversity per se was more important than biomass production for changes in soil carbon. Below 20 cm depth, the presence of one functional group, tall herbs, significantly reduced carbon losses in the beginning of the experiment. Our analysis indicates that plant species richness and certain plant functional traits accelerate the build‐up of new carbon pools within 4 years. Additionally, higher plant diversity mitigated soil carbon losses in deeper horizons. This suggests that higher biodiversity might lead to higher soil carbon sequestration in the long‐term and therefore the conservation of biodiversity might play a role in greenhouse gas mitigation.     

Plasma cell development in synovial germinal centers in patients with rheumatoid and reactive arthritis

Plasma cells are found surrounding the inflammatory infiltrates of macrophages, T, and B cells in the synovial tissue of patients with rheumatoid and reactive arthritis. This characteristic arrangement suggests that in the synovial tissue CD20+ B cells differentiate into plasma cells. To examine clonal relationships, we have used micromanipulation to separately isolate CD20+ B cells and plasma cells from single infiltrates. DNA was extracted, and from both populations the VH/VL gene repertoires was determined. The data show that in the inflamed synovial tissue activated B cells are clonally expanded. During proliferation in the network of follicular dendritic cells, V gene variants are generated by the hypermutation mechanism. Surprisingly, we do not find identical rearrangements between CD20+ B cells and plasma cells. Nevertheless, the finding of clonally related plasma cells within single infiltrates suggests that these cells underwent terminal differentiation in the synovial tissue. These results indicate that B cell differentiation in the synovial tissue is a dynamic process. Whereas CD20+ B cells may turnover rapidly, plasma cells may well be long lived and thus accumulate in the synovial tissue. The analysis of individual B cells recovered from synovial tissue opens a new way to determine the specificity of those cells that take part in the local immune reaction. This will provide new insights into the pathogenesis of chronic inflammatory diseases like rheumatoid or reactive arthritis.