高效液相色谱法测定斑纹芦荟中芦荟苷含量

目的：采用高效液相色谱法测定斑纹芦蔡中芦荟苷含量。方法：芦荟叶汁浓缩物用甲醇超声提取总蒽醌,经薄层色谱分离后,用高效液相色谱法测定,结果：方法回收率为９６．１７％,ＲＳＤ为１．００％（ｎ＝５）。结论：该法准确,且简便可靠,重现性好,为开发利用芦荟资源提供依据。     

Ambient Temperature and Mortality From Unintentional Cocaine Overdose

Context.— Hot weather taxes cardiovascular function and is associated with increased deaths from heart disease. Cocaine can cause hypertension, tachycardia, coronary vasospasm, arrhythmias, and increased core temperature. Objective.— To determine the association between mortality from cocaine overdose and hot weather. Setting.— New York, NY. Design.— Retrospective review of medical examiner cases from 1990 through 1995. Subjects.— All fatal unintentional cocaine overdoses from 1990 through 1992 (n=1382) and all hyperthermia deaths of cocaine users (n=10) were used to identify a maximum daily temperature threshold above which mortality from cocaine intoxication increased. The study population consisted of all fatal unintentional cocaine overdoses from 1993 through 1995 (n=2008) and 4 contemporaneous comparison groups that included fatal unintentional opiate overdoses (n=793), all other fatal unintentional overdoses (n=85), and a subset of homicides (n=4638) and fatalities from motor vehicle crashes (n=815). Main Outcome Measures.— The number of overdose deaths and the proportion of homicides and traffic fatalities with a positive cocaine toxicology test result on days with a maximum temperature above or below the temperature threshold. Results.— A threshold temperature of 31.1°C (88°F) was identified, above which the mean daily number of fatal cocaine overdoses increased steadily. On days with a maximum daily temperature of 31.1°C (88°F) or higher ("hot days"), the mean daily number of cocaine overdose deaths was 2.34 (SD=1.68), which was 33% higher than the mean on days with a maximum temperature of less than 31.1°C (88°F) (mean=1.76 [SD=1.37] (P<.001). In contrast, the mean number of opiate overdose deaths per day was 0.81 (SD=0.94) on hot days and 0.71 (SD=0.86) on other days (P=.28). For other drug overdose deaths, the mean number of deaths per day was 0.08 (SD=0.28) on hot days and 0.08 (SD=0.28) on other days (P=.69). Among homicides, the proportion with a positive cocaine toxicology test result was 18.9% on hot days and 19.5% on other days (P=.69), and among traffic fatalities, the proportions with positive cocaine toxicology test results were 9.5% on hot days and 10.3% on other days (P=.91). Conclusions.— High ambient temperature is associated with a significant increase in mortality from cocaine overdose. Based on our comparison groups, the increase is not explained by changes in cocaine use among the general population. Although cocaine use is dangerous on all days, it appears to be even more dangerous on hot days.      

High-resolution method for regulatory control of Echinacea species in Nutraceuticals by CD-MEKC

One problem in the international regulatory control of Echinacea, a therapeutic Nutraceutical, is recognition of caffeoyl solutes and alkamides in different products. Cyclodextrin-modified micellar electrokinetic chromatography (CD-MEKC) has been applied to Echinacea spp. in combination with pattern recognition of some caffeoyl solutes. A novel metric based on relative migration time (RMT) data has been developed in CE to address the problem of variable reported migration time.The CD-MEKC method of Gotti's group using hydroxypropyl-β-cyclodexrin (HP-β-CD; 100 mM) with sodium dodecyl sulphate (SDS; 110 mM), in a triacid background electrolyte (10 mM, pH 8) under 19 kV was adapted to identify two key hydrophilic solutes: chlorogenic acid and cichoric acid present in all commercial products. Two internal markers were taken as reference points to calculate the RMT of any target peak: RMT = t_{m (target)}/t_{m (marker)}.The RMT method was robust to temperature change from 20 to 40 °C, but sensitive to pH. The lateral shift and reproducibility of the target peak t_{m (target)} were significantly reduced by this novel transformation. In the worst cases migration time variability ranged up to 12% (n = 6); the RMT algorithm reduced this to less than 1%. In general, the RMT transformation reduced the variability of migration time data by a factor of 2–5.For systematic comparison of electrophoretic profiles for test sample and standard, a new pattern recognition algorithm permits sequential peak-by-peak comparison using specified segments of the electropherograms for comparison of test and Echinacea purpurea (root product) as a standard. This algorithm was capable of rapidly characterising the similarity of target peaks in a test sample relative to those in the reference standard. Combination of the RMT algorithm and pattern recognition in CE is expected to offer a robust approach to international regulatory characterisation and control of Nutraceuticals.     

High-resolution real-time ultrasonography of thyroid nodules

High-resolution real-time ultrasonography was used to evaluate 98 patients with palpable abnormalities of the thyroid and positive isotopic studies. It confirmed 37 of 73 (51%) suspected solitary nodules. Of 25 patients thought to have multinodular goiter, sonography was supportive in 21 (84%). In patients with adenoma or adenomatous nodules, characteristic features included a sonolucent "halo". Colloid nodules tended to be more sonolucent than normal thyroid tissue, whereas Hashimoto thyroiditis was characterized by an enlarged gland and decreased echogenicity.     

Serum urate concentrations in homozygous sickle cell disease

Serum and urinary urate concentrations were studied in 44 patients with homozygous sickle cell (SS) disease, and in 27 controls with normal haemoglobin. Hyperuricaemia (>0·39 mmol/l (6·5 mg/100 ml)) occurred in 41% of SS patients and inversely correlated with renal urate clearance but not with indices of bone marrow turnover. Higher serum urate concentrations occurred in patients with proteinuria, probably due to associated tubular damage. Higher serum urate concentrations and lower urate clearance occurred in males compared to females.     

高低通量血液透析膜清除溶质能力的比较

目的：比较高通量和低通量聚砜膜血液透析器对慢性肾功能衰竭维持性血液透析患者尿素氮、肌酐、血磷及β2-微球蛋白的清除能力. 方法：于2004-09/2005-01选择上海交通大学医学院附属新华医院血液透析中心维持性血液透析患者43例,血透时间1.5～5.0年.实验经医院伦理委员会审批,患者均知情同意.①实验分组：按随机数字表法分为高通量透析组23例和低通量透析组20例.②实验方法：高通量透析组采用F60聚砜膜血液透析器,超滤系数Kuf为40 mL/（h·mm Hg）.低通量透析组采用F6聚砜膜血液透析器,超滤系数Kuf为5.5 mL/（h·mm Hg）.所有患者透析3次/周,4 h/次,均采用Fresenius 4008S容量控制型透析机和超纯净水碳酸氢盐透析液,透析液流量500 mL/min,血流量190～250 mL/min,采用肝素抗凝,共5个月.③实验评估：两组患者透析前后常规检测血尿素氮、肌酐、血磷浓度;采用放射免疫方法测定血β2-微球蛋白含量,观察透析前后各种溶质含量变化,计算其溶质清除率. 结果：①血尿素氮、肌酐和血磷浓度变化：两组患者透析前后血尿素氮、肌酐和血磷浓度均显著下降.两组血尿素氮、肌酐和血磷的清除率差异无显著性意义（P＞0.05）,表明高通量和低通量血液透析均能有效清除维持性血液透析患者血液中的小分子溶质.②β2-微球蛋白含量变化：高通量透析组透析后β2-微球蛋白含量显著下降,低通量透析组透析前后β2-微球蛋白含量无显著变化.清除率组间差异有显著性意义（t=3.62,P＜0.05）. 结论：应用高通量F60聚砜膜血液透析器和低通量F6聚砜膜血液透析器均能有效清除维持性血液透析患者血液中的小分子溶质,但高通量F60聚砜膜血液透析器对β2-微球蛋白的清除能力显著优于低通量F6聚砜膜血液透析器.     

The antineoplastic bryostatins affect human basophils and mast cells differently

Bryostatins, macrocyclic lactones from the marine bryozoan Bugula neritina, are potent antineoplastic agents and multi-potential stimulators of immune cells. We have examined the effects of bryostatins on mediator release from human basophilic leukocytes and human tissue mast cells. Bryostatins 1, 2, and 5 (10 to 3,000 nmol/L) induced histamine secretion from purified and unpurified peripheral blood basophils, whereas they caused no release of peptide-leukotriene C4 from these cells. The rate of histamine release caused by bryostatin 1 was slower than that caused by anti-IgE (t1/2 +/- SEM = 38.2 +/- 4.7 minutes v 8.9 +/- 0.2 minutes; P < .01), whereas the temperature dependence was similar (optimum release at 37 degrees C, approximately 30% less at 30 degrees C, and no release at 22 degrees C or 4 degrees C). The addition of increasing concentrations of extracellular Ca2+ to the medium caused histamine release in the presence of bryostatins. Subeffective concentrations of bryostatins and anti-IgE produced a synergistic effect on histamine release from basophils. Staurosporine, chelerythrine, and calphostin C (0.1 to 10 nmol/L), which are protein kinase C inhibitors, inhibited the histamine secretion activated by bryostatin 1 and tetradecanoylphorbol-acetate (TPA). Preincubation with granulocyte-monocyte colony-stimulating factor (GM-CSF; 1 and 5 nmol/L) and interleukin-3 (IL-3; 10 ng/mL) potentiated the activation of human basophils induced by bryostatin 1. Neither bryostatin 1 nor bryostatin 2 induced the release of histamine from mast cells isolated from human lung or skin tissues. However, brief (10 minutes) preincubation with bryostatin 1 (3 to 300 nmol/L) potently inhibited the histamine secretion induced by anti-IgE from skin or lung mast cells. Bryostatin 1 was a more potent (by approximately 30 times) inhibitor of IgE- mediated histamine release than was TPA. The heterogeneous effects exerted by bryostatins on human basophils and mast cells can be of interest for those designing therapeutic trials using these agents.     

An in vitro evaluation of injectable thermoplasticized gutta-percha, glass ionomer, and amalgam when used as retrofilling materials

An in vitro dye leakage study was performed to evaluate the sealing ability of the following retrofilling materials: high- and low-temperature injectable thermoplasticized gutta-percha with and without sealer, a glass ionomer cement, and amalgam with and without varnish. The roots of 105 extracted human maxillary anterior teeth were instrumented and obturated with single cones of gutta-percha and sealer. The apical 3 mm of the roots were then resected and 2-mm deep retrograde preparations were prepared. Each root was then randomly placed into one of seven groups and retrofilled with one of the test materials. After 72 h in India ink, the roots were cleared and evaluated for leakage using a stereomicroscope. Statistical analysis of the results indicated that injectable high-temperature gutta-percha without sealer demonstrated significantly more leakage than the other materials. There were no significant differences in leakage among the other evaluated materials.