石菖蒲乙醇提取物石油醚部分化学成分的研究

目的:对石菖蒲乙醇提取物的石油醚部分进行化学成分研究.方法:采用柱色谱、重结晶等分离纯化化合物,应用EI-MS,NMR等波谱技术鉴定化合物结构.结果:从石菖蒲乙醇提取物石油醚萃取部分分得7个化合物,经波谱分析鉴定为1-hydroxy-7(11),9-guaiadien-8-one(1),菖蒲醇酮(2),α-细辛醚(3),1,8二羟基-3-甲基蒽醌(4),1,8-二羟基-3-甲氧基-6-甲基蒽醌(5),1,3,8-三羟基-6-甲基蒽醌(6),(+)-galbacin(7).结论:化合物l为新化合物,化合物4～7均为首次从该植物中分到.     

酶化学发光法测定何首乌中四羟基二苯乙烯葡萄糖甙的含量

报道一种新的何首乌中二苯乙烯甙含量的测定方法──酶化学发光法。该方法对二苯乙烯甙的检测限量为２．５×１０－７ｍｏｌ／Ｌ标准偏差小于２％，标准回收率在９６％～１０４％之间，线性范围为５．０×１０－７～１．０×１０－４ｍｏｌ／Ｌ。测定结果与紫外分光光度法基本一致。本法灵敏度较高，稳定性好，可用于中草药何首乌中二苯乙烯甙含量的测定。     

Treatment of recurrent periodontal disease by root planing and Ornidazole (Tiberal®)

The purpose of this study was to evaluate the use of Ornidazole as an adjunct to root planing in the therapy of patients suffering from recurrent periodontal disease. In 10 individuals who had previously been treated with scaling, root planing and periodontal surgery and who had followed a regular maintenance program including recall visits every 3-5 months for 1-7 years, 2 sites with recurrent periodontitis and 1 shallow site were selected. Reinfected sites had a record of losing clinical attachment of more than 3 mm since the completion of initial therapy, were bleeding upon probing and had a mean pocket probing depth of 7.85 +/- 1.31 mm. They had been reinstrumented several times by a registered dental hygienist, when clinical signs of recurrence of disease had appeared and the root surfaces were judged to be smooth and free of deposits. Clinical parameters were recorded and microbial samples were collected twice prior to retreatment. Then, 500 mg Ornidazole, to be taken twice a day for 10 days, was administered, and the whole dentition was thoroughly scaled and root planed. At day 10 as well as 2, 5, 8 and 11 months thereafter, samples were again obtained. At baseline, reinfected sites showed over 20% spirochetes, over 20% motile rods and over 9% fusiform organisms in darkfield preparations of subgingival plaque samples. Culturally, over 1/10 of organisms were identified as black pigmenting Bacteroides and in 18% of all baseline samples collected, B. gingivalis was found.(ABSTRACT TRUNCATED AT 250 WORDS)     

Species Differences of Serum Albumins: II. Chemical and Thermal Stability

Purpose. The chemical and thermal stability of five species of mammalian serum albumins (human, bovine, dog, rabbit, and rat) were investigated, and conformational stabilities were compared to obtain structural information about the different albumins. Methods. The chemical stability was estimated by using guanidine hydrochloride (GdnCl), and monitored by fluorometry and circular dichroism (CD). Thermal stability was evaluated by differential scanning calorimetry (DSC). Results. In human, bovine, and rat albumin, two transitions were observed when GdnCl-induced denaturation was monitored fluorometrically, indicating at least one stable intermediate, although, in dog and rabbit albumin, only one transition was observed. However, GdnCl denaturation, as monitored by the ellipticity, showed a two-state transition in all species used in this study. Since these proteins, showing two transitions, contained a conserved tryptophan residue within domain II, these structural changes might have occurred in domain II during intermediate formation. DSC measurements showed that human, bovine, and rat albumin exhibited single sharp endotherms and these were clearly consistent with a two-state transition, while the deconvolution analysis of broad thermograms observed for dog and rabbit albumin showed that the absorption peaks could be approximated by a two-component composition, and were consistent with independent transitions of two different cooperative blocks. Conclusions. These experimental results demonstrate that species differences exist with respect to the conformational stability and the mechanism of the unfolding pathway for mammalian albumin.     

Studies on the Chemical Constituents of Epimedium koreanum Nakai and Epimedium wanshanense,S.Z.He et Guo

ＳｔｕｄｉｅｓｏｎｔｈｅＣｈｅｍｉｃａｌＣｏｎｓｔｉｔｕｅｎｔｓｏｆＥｐｉｍｅｄｉｕｍｋｏｒｅａｎｕｍＮａｋａｉａｎｄＥｐｉｍｅｄｉｕｍｗａｎｓｈａｎｅｎｓｅＳ．Ｚ．ＨｅｅｔＧｕｏＰｈ．Ｄ．ＤｅｇｒｅｅＷｅｎ－ＫｕｉＬｉ１ＳｕｐｅｒｖｉｓｏｒｓＰｒｏ...     

顺铂壳聚糖微球制备工艺的研究

选择壳聚糖为材料，用乳化化学交联技术制备顺铂壳聚糖微球，研究了影响微球制备的因素，在此基础上选择壳聚糖浓度（因素Ａ）、水／油相体积比（因素Ｂ）、搅拌速度（因素Ｃ）、药物与鞯体材料用量比（因素Ｄ）、油相类型（因素Ｅ）、壳聚糖种类（因素Ｆ）及固化时间（因素Ｇ）七个因素，每个因素选择三水平，用正交实验设计安排实验，并以微球 载药量，药物包封率，粒子分布百分数为指标优化微球的制备工艺。     

有机磷化合物~(31)P-NMR及其规律研究——Ⅰ.~(31)P-NMR化学位移变化新的经验规律和原理

由于影响~(31)P-NMR化学位移变化的结构因素极其复杂,科学家们试图建立一个统一的理论模型来说明各类磷化合物的~(31)P-NMR没有获得成功。我们在总结归纳自己200个和文献近千个实验数据的基础上,分析比较了有机磷酸酯结构类型与~(31)P-NMR化学位移的关系。首次观察到~(31)P-NMR化学位移可用5条经验规律来说明。研究表明:有机磷化合物的~(31)P-NMR化学位移及其经验规律是由核外电子云球对称性(而非电子云密度)决定的。     

Effect of glycaemic control on myocardial sympathetic innervation assessed by [123I]metaiodobenzylguanidine scintigraphy: a 4-year prospective study in IDDM patients

Summary Diabetic cardiovascular autonomic neuropathy (CAN) has been directly characterized by reduced or absent myocardial [¹²³I]metaiodobenzylguanidine (MIBG) uptake, but there is no information available on the relationship between the myocardial adrenergic innervation defects and long-term glycaemic control. In a prospective study over a mean of 4 years we examined myocardial sympathetic innervation in 12 Type 1 (insulin-dependent) diabetic patients using MIBG scintigraphy (absolute and relative global MIBG uptake at 2 h p. i.) in conjunction with cardiovascular autonomic function tests, QTc interval, and QT dispersion. Six healthy non-diabetic subjects served as controls for the MIBG scintigraphy at baseline. HbA_1c was measured twice a year. One patient, in whom MIBG accumulation was reduced maximally, died during follow up. Among the remaining patients 5 had good or borderline glycaemic control (mean HbA_1c < 7.6 %; Group 1), whereas 6 patients were poorly controlled (mean HbA_1c L 7.6 %; Group 2). Absolute global MIBG uptake increased from baseline to follow-up by 260 (−190–540) [median (range) ] cpm/g in Group 1 and decreased by −150 (−450–224) cpm/g in Group 2 (p < 0.05 vs Group 1). Relative global MIBG uptake decreased by −1.7 (−3.4–9.4) % in Group 1 and by −4.7 (−17.4–1.3) % in Group 2 (p < 0.05 vs Group 1). No differences between the groups were noted for the changes in the automatic function tests, QTc interval, and QT dispersion. In conclusion, long-term poor glycaemic control constitutes an essential determinant in the progression of left ventricular adrenergic dysinnervation which may be prevented by near-normoglycaemia. Evaluation of susceptibility to metabolic intervention may be superior when CAN is characterized directly by MIBG scintigraphy rather than by indirect autonomic function testing. [Diabetologia (1998) 41: 443–451] Received: 15 July 1997 and in revised form: 25 November 1997     

Optimization of chemical shift selective suppression of fat

Strategies to optimize flip angles for chemical shift selective fat suppression are discussed. Mathematical models for fat suppression in spoiled gradient recalled acquisition, spin echo, and RARE, which incorporate steady state conditions and multiple spectral components of fat, are developed. The optimal suppression flip angle is found to be larger than that determined with a single fat component model by more than 10° due to contributions from unflipped components such as olefinic and glycerol protons that lie outside the suppression band.