Serum magnesium levels in asthmatic patients during acute exacerbations of asthma.

The purpose of this study was to determine whether serum magnesium levels in asthmatic patients during acute exacerbations differ from those of a control population. Twenty-three known asthmatics presenting to the emergency department in acute exacerbation (cases) and 15 nonasthmatic patients (controls) matched for age, sex, race, and socioeconomic status had serum magnesium assays drawn. Admission criteria were: age 18 to 50 years with no history of alcoholism, heart disease, renal disease, or diuretic use. Patients giving a history of pregnancy were excluded. Serum magnesium levels were not significantly different in the two study populations, nor did they correlate with the severity of asthma (mean values: cases, 2.04 +/- 0.159 versus controls, 2.03 +/- 0.134 mg/dL; SD of the difference of the means = .048). An analysis for beta-error demonstrated the true difference of the means to be less than .1 (95% confidence) or less than .13 (99% confidence). In conclusion, serum magnesium levels in asthmatics are not significantly different from those of a control nonasthmatic population. They are not clinically useful for predicting the severity of disease.     

Case mix measures and diagnosis-related groups: opportunities and threats for inpatient dermatology

OBJECTIVE: The changing healthcare environment world-wide is leading to extensive use of per case payment systems based on diagnosis-related groups (DRG). The aim of this study was to examine the impact of application of different DRG systems used in the German healthcare system. METHODS: We retrospectively analysed 2334 clinical data sets of inpatients discharged from an academic dermatological inpatient unit in 2003. Data were regarded as providing high coding quality in compliance with the diagnosis and procedure classifications as well as coding standards. The application of the Australian AR-DRG version 4.1, the German G-DRG version 1.0, and the German G-DRG version 2004 was considered in detail. To evaluate more specific aspects, data were broken down into 11 groups based on the principle diagnosis. MAIN OUTCOME MEASURE: DRG cost weights and case mix index were used to compare coverage of inpatient dermatological services. Economic impacts were illustrated by case mix volumes and calculation of DRG payments. RESULTS: Case mix index results and the pending prospective revenues vary tremendously from the application of one or another of the DRG systems. The G-DRG version 2004 provides increased levels of case mix index that encourages, in particular, medical dermatology. CONCLUSIONS: The AR-DRG version 4.1 and the first German DRG version 1.0 appear to be less suitable to adequately cover inpatient dermatology. The G-DRG version 2004 has been greatly improved, probably due to proceeding calculation standards and DRG adjustments. The future of inpatient dermatology is subject to appropriate depiction of well-established treatment standards.     

Spatial and evolutionary predictability of phytochemical diversity

To cope with environmental challenges, plants produce a wide diversity of phytochemicals, which are also the source of numerous medicines. Despite decades of research in chemical ecology, we still lack an understanding of the organization of plant chemical diversity across species and ecosystems. To address this challenge, we hypothesized that molecular diversity is not only related to species diversity, but also constrained by trophic, climatic, and topographical factors. We screened the metabolome of 416 vascular plant species encompassing the entire alpine elevation range and four alpine bioclimatic regions in order to characterize their phytochemical diversity. We show that by coupling phylogenetic information, topographic, edaphic, and climatic variables, we predict phytochemical diversity, and its inherent composition, of plant communities throughout landscape. Spatial mapping of phytochemical diversity further revealed that plant assemblages found in low to midelevation habitats, with more alkaline soils, possessed greater phytochemical diversity, whereas alpine habitats possessed higher phytochemical endemism. Altogether, we present a general tool that can be used for predicting hotspots of phytochemical diversity in the landscape, independently of plant species taxonomic identity. Such an approach offers promising perspectives in both drug discovery programs and conservation efforts worldwide.

Phytochemical diversity describes the richness and abundance of the specialized metabolites produced by vegetation. It is a key aspect of plant functional diversity and, thus, affects plant fitness (1), ecosystem functioning (2), and services to humankind (3). Despite its relevance, chemical ecologists still struggle to understand both the evolutionary origin of phytochemical diversity and its variation across ecosystems (4). Only a small fraction of the >300,000 currently described phytochemicals (5) has been ascribed to a known ecosystem function or process (6). This is because most identification work has been undertaken on model organisms, such as crop plants (7), and because drug discovery programs have so far been based on prior ethno-medicinal knowledge or random sampling, rather than systematic sampling from the tree of life (8) or guided by ecologically relevant information (9). The ability to better predict the presence and diversity of phytochemicals of interest from phylogenetic information, or from specific environments or habitat types, could uncover the full spectrum and function of phytochemicals in the landscape while also orienting drug discovery research (10). Moreover, documenting landscape variability in phytochemical diversity is particularly important in the context of land use change, which is causing losses of plants that possess a yet-unknown value to medicine and science (11).The plant metabolome includes both primary functions, expected to be conserved across species, and specialized functions, associated to specific lineages or environments (1). Thus, phytochemical variation in the landscape is expected to arise from a combination of evolutionary (12, 13) and ecological (14, 15) constraints. From a macroevolutionary standpoint, some classes of phytochemical compounds are specific to plant clades (e.g., glucosinolates in Brassicaceae, or tropane alkaloids in Solanales; ref. 16). Such lineage-dependent variation is thought to be driven by chemical defense innovations followed by coevolutionary dynamics with herbivores (17, 18). In particular, the escape-and-radiate model (13) predicts that plant lineages diversify by creating novel, more potent, or complex chemical mixtures in response to biotic pressure (19). Therefore, plant lineages that have experienced more evolutionary split events are predicted to have evolved higher levels of phytochemical diversity (13). From an ecological perspective, phytochemical diversity is expected to be the result of plant adaptation to abiotic and biotic conditions, both of which vary along ecological gradients in landscapes (2, 20). For example, habitats that impose constraints on plant growth, such as cold and resource-poor environments, may be expected to drive selection toward potent chemical defense mechanisms that reduce tissue loss (21). At the same time, it is well established that herbivores and pathogens can promote divergent selection between plant congeners, leading to increasing chemical dissimilarity (22). As such, species relatedness alone is a poor predictor of site-level phytochemical diversity.Here, we questioned whether phytochemical diversity can be predicted from the phylogenetic and ecological heterogeneity observed in the landscape. We hypothesized that phytochemical diversity is not only related to local plant species diversity but is also constrained by other ecological factors, especially trophic, climatic, edaphic, and topographic variation. We developed a methodological framework involving: 1) comprehensive sampling of plant species along ecological transects that cover the entire range of regional vegetation ecological boundaries; 2) assessing species-level phytochemical composition and combining it with species distribution models (SDMs) for extrapolating phytochemical diversity across the landscape based on species occurrences; 3) extracting climatic and topographical variables associated with each unique molecule observed across all species to build molecular distribution models (MDMs); and 4) projecting phytochemical diversity and composition across the landscape based on these MDMs (SI Appendix, Fig. S1). Here, we consider phytochemical diversity both as the richness of clustered metabolic features and the presence/absence of the families of compounds they represent. We expected that phytochemical diversity values compiled from the projected MDMs would better explain plot-level phytochemical diversity and composition than phytochemical diversity calculated from plant species composition alone.     

Increased infection mortality and decreased neutrophil migration due to a component of an artificial blood substitute

We previously showed that an artificial blood substitute containing perfluorocarbons, Fluosol-DA, inhibited both neutrophil migration and adherence, due to its detergent component, Pluronic F-68. The purpose of the studies we report here was to determine if Fluosol or Pluronic might also reduce in vivo neutrophil migration and impair host resistance to bacterial infection. We studied in vivo PMN migration by injecting mice intraperitoneally (IP) with glycogen, followed by intravenous (IV) infusion of saline, Fluosol, or Pluronic. Peritoneal lavage after eight hours showed a significant decrease in the accumulation of PMN in lavage fluids of animals given either Fluosol or Pluronic (control--.19 +/- .03 X 10(6) PMN/mL, glycogen--1.35 +/- .14; glycogen/Fluosol--0.63 +/- .12; glycogen/Pluronic--0.69 +/- .07). We ascertained the effect of Fluosol and Pluronic on infection mortality by injecting mice IV with saline, Fluosol, or Pluronic, followed by a quantity of E coli (0.6 X 10(7] IP shown in preliminary studies to kill 20% to 50% of the mice in 24 hours. The 24-hour mortality was 14/45- saline, 24/32-Fluosol (chi 2 = 17.1; P less than .001) and 17/23 - Pluronic (chi = 11.2; P less than .001). Neither Fluosol nor Pluronic caused mortality without E coli. The increase in infection mortality occurred when Fluosol was given either two hours before, or simultaneously with E coli, but only with the simultaneous administration of bacteria and Pluronic. Pluronic did not alter reticuloendothelial system (RES) clearance function. These studies indicate that, in an animal model, Fluosol-DA, due to its detergent component Pluronic F-68, impaired neutrophil delivery to an inflammatory locus, and resulted in an increased rate of infection mortality. Since Pluronic did not result in RES blockade, but did impair the delivery of PMN to an inflammatory locus, our results suggest that the latter effect is responsible for the increase in infection mortality.     

The global burden of headache in children and adolescents – developing a questionnaire and methodology for a global study

Background

Burden of headache has been assessed in adults in countries worldwide, and is high, but data for children and adolescents are sparse. The objectives of this study were o develop a questionnaire and methodology for the global estimation of burden of headache in children and adolescents, to test these in use and to present preliminary data.

Methods

We designed structured questionnaires for mediated-group self-administration in schools by children aged 6-11 years and adolescents aged 12-17 years. In two pilot studies, we offered the questionnaires to pupils in Vienna and Istanbul. We performed face-to-face interviews in a randomly selected subsample of 199 pupils to validate the headache diagnostic questions.

Results

Data were collected from 1,202 pupils (mean 13.9 ± 2.4 years; 621 female, 581 male). The participation rate was 81.1% in Istanbul, 67.2% in Vienna. The questionnaire proved acceptable: ≤5% of participants disagreed partially or totally with its length, comprehensibility or simplicity. The sensitivity, specificity, positive and negative predictive values ranged between 0.71 and 0.76 for migraine and between 0.61 and 0.85 for tension-type headache (TTH). Cronbach’s alpha was 0.83. The 1-year prevalence of headache was 89.3%, of migraine 39.3% and of TTH 37.9%. The prevalence of headache on ≥15 days/month was 4.5%. One fifth (20.7%) of pupils with headache lost ≥1 day of school during the preceding 4 weeks and nearly half (48.8%) reported ≥1 day when they could not do activities they had wanted to. The vast majority of pupils with headache experienced difficulties in coping with headache and in concentrating during headache. Quality of life was poorer in pupils with headache than in those without.

Conclusion

These pilot studies demonstrate the usefulness of the questionnaires and feasibility of the methodology for assessing the global burden of headache in children and adolescents, and predict substantial impact of headache in these age groups.     

高钠血症影响重型颅脑损伤预后的临床分析及处理

目的分析并探讨高钠血症对重型颅脑损伤患者预后产生的影响及处理对策。方法对我院自2007年11月至2010年10月期间收治的78例重型颅脑损伤后伴高钠血症患者的临床资料做回顾性分析。78例患者按血清钠水平分为高血钠组及高血钠组。结果全部78例重型颅脑损伤患者中继发高钠血症者37例,发生高钠血症组的GCS评分为3～5分者30例,GCS评分为6～8分者7例,两组相比差异显著（P〈0.01）,具有统计学意义。高钠血症患者有27例死亡,10例生存,两组的病死率相比,差异亦显著（P〈0.01）,具有统计学意义。结论患者高钠血症的病情程度和GCS分值具有密切的相关性。对于高钠血症,临床工作中必须充分提高预防意识,重视其严重后果尽早采取纠正高钠血症措施,在保守治疗无效的情况下,应尽早开始血液净化治疗,改善患者的预后。