Method transfer for fast liquid chromatography in pharmaceutical analysis: application to short columns packed with small particle. Part I: isocratic separation.

Liquid chromatography (LC) is considered to be the gold standard in pharmaceutical analysis. Today, there is a need for fast and ultra-fast methods with good efficiency and resolution for achieving separations in few minutes or even seconds. The present work describes a simple methodology for performing a successful method transfer from conventional LC to fast and ultra-fast LC. In order to carry out fast separations, short columns (20-50mm) packed with small particles (3.5 and 1.7 microm) were used and their chromatographic performance was compared to that of a conventional column (150 mm, 5 microm). For that purpose, an optimized LC system was employed to limit extra-column volumes which can have a dramatic impact on efficiency and resolution. This paper reports the fundamental equations used for transferring an isocratic chromatographic separation performed with a given column geometry and chemistry to a smaller column packed with similar or identical stationary phase, without influence on chromatographic performance. For this purpose, the flow rate and the injected volume need to be adapted. The effect of column length and particle size reduction on chromatographic resolution and analysis time was described for an isocratic separation. Using the method transfer equations, it is possible to predict the new conditions to be used, for fast and ultra-fast separations. In this work, ultra-fast separations were achieved thanks to a new generation of instrumentation (ultra performance liquid chromatography, UPLC) which uses simultaneously short column packed with sub-2 microm particles and ultra-high pressure (up to 1000 bar). This work demonstrates an analysis time reduction up to a factor 12, compared to a conventional LC separation, without affecting the quality of separation. Therefore, the complete resolution of a pharmaceutical formulation was achieved in only a few seconds.     

论傣医药文化与贝叶文化的关系

我国“四大民族医药”（藏、蒙、维、傣）之一的傣族传统医药学,是祖国医学的重要组成部分。具有2000多年的悠久历史,傣医药文化蕴载着傣族人民的勤劳与睿智,体现了傣族文化的底蕴和内涵,是西双版纳一块摧璨的知识堡垒。据《贝叶经》记载,早在2500多年前傣族就有了自己的医药,但均为零散,大多以口传、手教形式相传,直到文字产生,佛教传入后,才以《贝叶经》记载相传。千百年来,傣族人民在长期的生活实践和与各种疾病作斗争的过程中,积累了许多宝贵的诊疗治病经验和方药,     

Basocellular epitheliomas of the eyelids

On the basis of a retrospective study of 354 basal-cell epitheliomas of the eyelids, we present a study of the most frequently used treatments: surgery, conventional radiation therapy and curietherapy. The results of treatment, both functional and oncological, are generally satisfactory, whatever the method chosen, but with a set of arguments in favor of surgery. The major therapeutic indications are discussed, without formally ruling out any treatment.     

Anthropometric status, serum prealbumin level and immune response to measles vaccination in Mali children.

Protein energy malnutrition (PEM) is known to depress cell-mediated immunity. Its effect on humoral immunity is less clear-cut. The purpose of the study was to assess seroconversion following measles vaccination according to child nutritional status as assessed by anthropometry and serum thyroxine-binding prealbumin (TBPA). Prior to vaccination, 200 Malian children aged 8-22 months (mode: 9 months) and free of infection were weighed and measured. A venous blood sample was drawn for determination of serum TBPA by radial immunodiffusion and of measles specific immunoglobulins (Ig) by Enzyme-linked Immuno-Sorbent Assay (ELISA). IgG and IgM were again assayed 6 weeks post-vaccination after excluding pre-immune subjects. Seroconversion took place in 91 per cent of the children (95 per cent confidence interval: 86-96 per cent). Based on the NCHS standards, 30 per cent of the children were wasted (weight-for-height less than -2.0 SD) and 18 per cent were stunted (height-for-age less than -2.0 SD). Low serum TBPA (less than 10 mg/dl) was found in 38 per cent of them. TBPA was significantly correlated with weight-for-height and weight-for-age (P less than 0.001), but not with height-for-age. Seroconversion was not significantly related to age, anthropometric indices or TBPA. This study using sensitive methods for the assessment of protein status and of the immune response confirms that children should be vaccinated against measles irrespective of their nutritional status, and PEM was not shown to impair their antibody response.     

中风病急性期证候演变规律的研究

应用证候量化诊断的方法,对733例经CT或MRT确诊的中风病始发态患者,进行了为期4周的7次追踪调查.结果显示:(1)证候的得分均值、发生概率、组合形式、组合形态是动态变化的随时间序列呈现一定的规律性,并受到病变性质的影响;(2)求得了不同时间序列6个基本证候的逐阶转移概率和高阶转移概率.研究结果对深入认识中风病急性期病因病机,判断病势转归,指导辨证治疗,防止向恶转变,具有重要的理论意义和应用价值.     

Incorporation and integration of implanted myogenic and stem cells into native myocardial fibers: anatomic basis for functional improvements

BACKGROUND: Myoblasts and stem cells implanted into myocardium can differentiate into myocytes and may functionally improve impaired ventricles. For implanted cells to actually contribute to the synchronous contractions of the heart, however, they must be anatomically integrated with the existing native myocardial fibers. METHODS: Isogenic Lewis rats were used as donors and recipients to simulate clinical autotransplantation. Either skeletal myoblasts or marrow stromal stem cells were isolated from donors, culture expanded, and labeled with 4',6-diamidino-2-phenylindole (4',6-diamidino-2-phenylindole). Labeled cells were then injected into the myocardium of recipients. At intervals specimens were obtained, sectioned, and stained with hematoxylin and eosin and immunohistochemically against connexin-43 to demonstrate gap junctions (intercalated discs). RESULTS: At 1 week the labeled cells were still undifferentiated, but early expression of connexin-43 could be detected at contact points between the implanted cells and the native myocytes. By 4 to 6 weeks, labeled, fully differentiated myocytes could be seen to interconnect among themselves and with native cardiomyocytes by means of intercalated discs. In sections parallel to the myofibers, full integration of new labeled myocytes with the native myofiber cells could be observed. Furthermore, the labeled myofibers were in parallel with the native, unlabeled fibers. We postulate that such supracellular structural integration was enhanced by fiber stretching during cardiac contractions, sending signals for cellular reorientation and incorporation, in which the cytoskeletal system may play an important role. CONCLUSION: We conclude that implanted precursor cells can be integrated into native myocardial structure so as to contribute to myocardial function. Direct cell-to-cell contact seems to be an important signaling mechanism, which has implications for cellular implantation strategies.     

糖尿病合并类鼻疽伯克霍尔德菌败血症临床研究

目的分析糖尿病合并类鼻疽伯克霍尔德菌败血症的临床特点，并探讨其诊疗策略和措施。方法回顾性分析21例糖尿病合并类鼻疽伯克霍尔德菌败血症的临床特点、诊疗经过和转归。结果类鼻疽伯克霍尔德菌败血症临床表现多样化，缺乏特异性，常表现为急性暴发性败血症和常伴组织器官脓肿形成及易诱发糖尿病酮症酸中毒（DKA），病情凶险，误诊率和死亡率高且可选用的有效抗生素较少，易复发，治疗周期长。结论早期诊断，尽旱足量应用敏感抗生素，有脓肿者宜配合外科治疗，以及使用胰岛素积极控制好血糖和加强支持疗法是治疗成功的关键。     

不同人群患代谢综合征调查分析

目的调查城市干部群体代谢综合征及其相关疾病的患病情况,并与农民群体对比。方法检测中山市1 116例处级干部血糖、血脂、血压和体重指数等,对结果进行统计分析并和同期农民群体相比较。结果干部体检人员中高血糖、高血压、血脂紊乱、超重或肥胖、代谢综合征的患病率分别为23.7%、52.6%、53.9%、31.5%、18.1%。明显高于农村群体的4.3%、32.4%、27.3%7、.8%、2.9%。结论干部群体中代谢综合征及其相关疾病的患病率较农民群体显著增高,应列为重点防治人群。