白首乌化学成分的研究

自白首乌主要品种耳叶牛皮消(Cynanchum auriculatum Royle ex Wight)根中首次分得三个已知甾体酯型甙元:告达亭(caudatin),开德甙元(kidjolanin),萝藦甙元(Metaplexigenin)和一种新的二苯酮衍生物(Ⅳ),经光谱分析推定其结构为2,6,2′,5′-四羟基,3-乙酰基,6′-甲基二苯酮,命名白首乌二苯酮。     

用差示扫描量热法及激光拉曼光谱研究足叶乙甙对二棕榈酰磷脂酰胆碱脂质体膜流动性影响

本文用DSC和激光拉曼光谱研究抗癌药物足叶乙甙(4-去甲基表鬼臼毒素-β-D-乙叉吡喃葡萄糖甙,简称VP 16-213)与二棕榈酰磷脂酰胆碱(DPPC)脂质体的作用。VP 16-213分子掺入DPPC脂质体双层中,不但使相转变温度向高温移动,而且吸热峰的半高宽度随VP 16-213浓度增加而变宽。其Raman光谱在频率2850 cm~(-1)处的C-H键对称伸缩振动亦随着药物浓度增加而减弱。这些结果表明VP 16-213分子是定域在脂双层中DPPC分子链的C_1～C_9亚甲基区域,使脂质体的有序性提高而流动性降低。     

白首乌化学成分的研究

自白首乌主要品种耳叶牛皮消(Cynanchum auriculatum Royle ex Wight)根中首次分得三个已知甾体酯型甙元:告达亭(caudatin),开德甙元(kidjolanin),萝藦甙元(Metaplexigenin)和一种新的二苯酮衍生物(Ⅳ),经光谱分析推定其结构为2,6,2′,5′-四羟基,3-乙酰基,6′-甲基二苯酮,命名白首乌二苯酮。     

急性心肌梗死后CD34+干细胞自体动员的意义

目的:已有理论提出急性心肌梗死后骨髓和外周血中的CD34 干细胞具有自身动员的潜能,观察这一潜能的变化特征及其对心肌梗死组织再生能力的影响。方法:实验于2004-09/2005-02在阜外心血管病医院完成。①实验动物:雄性SD大鼠40只,随机数字表法分为心肌梗死组、假手术组,20只/组。②实验方法:心肌梗死组大鼠采用冠状动脉结扎法建立心肌梗死模型。心电图ST段抬高或有室性心律出现,前壁心肌呈苍白色为造模成功。假手术组仅作开胸手术,前降支不予结扎。③实验评估:于心肌梗死后3,7,14,28d,流式细胞仪检测骨髓和外周血中CD34 干细胞的含量。用免疫组化方法检测梗死心肌组织中的Ki67细胞和毛细血管数量。结果:①外周血及骨髓CD34 干细胞含量的变化:心肌梗死组外周血中的CD34 干细胞数量于造模后3d开始上升,7d后明显高于假手术组(P<0.01),至14,28d时逐渐回落至假手术组水平(P>0.05)。心肌梗死组骨髓中的CD34 干细胞数量于造模后各时间点始终无明显变化(P>0.05)。②组织学评定:心肌梗死组梗死区Ki67细胞和毛细血管数量于造模后3d开始增多,7d时明显多于非梗死区(P<0.05);至14,28d梗死区Ki67细胞数量明显少于造模后7d(P<0.05),毛细血管数量的减少不明显(P>0.05)。免疫组化染色显示少数Ki67细胞分化为血管内皮细胞,未见向心肌细胞分化。③相关性分析:梗死区Ki67细胞、毛细血管数量于造模后7d与外周血中CD34 干细胞数量呈显著正相关(r=0.913,P=0.021;r=0.887,P=0.035)。结论:机体CD34 干细胞的自体动员、增殖反应的潜能随急性心肌梗死时间的延长而逐渐减弱,自体动员的干细胞功能尚不足以达到修复梗死心肌组织的效果。     

继续医学教育活动的有效性

继续医学教育的目的是通过向医生提供最新的医学知识和技能,使医生在其整个职业生涯中,一直保持较高的医疗水平.但目前还没有充足的证据能证明继续医学教育活动的有效性,以及在继续医学教育活动中哪些教育方法和技术能最有效地传播和记忆医学知识.为了全面、系统地评估继续医学教育活动的有效性,以及了解不同的教育手段对医生知识、态度、技能、临床表现和临床效果的作用.美国约翰·霍普金斯大学医学院、美国医疗保健研究与质量管理署和美国胸科医师学会的专家共同进行了一项系统回顾性研究.     

Purified murine hematopoietic stem cells function longer on nonirradiated W41/Wv than on +/+ irradiated stroma

Mouse bone marrow (BM) was separated into low-density, lineage- negative, wheat germ agglutinin-positive (WGA+), Rhodamine-123 bright (Rhbright) or dim (Rhdim) cells to obtain populations that were highly enriched for committed progenitors (Rhbright cells) or for more primitive stem cells (Rhdim). When 2,500 Rhbright or Rhdim cells were seeded onto 6-week-old irradiated (20 Gy) long-term BM cultures (LTBMC), the nonadherent cell production from Rhbright cells was transient and ended after 5 weeks. Production from Rhdim cells did not begin until week 3, peaked at week 5, and ended at week 8, when the irradiated stroma seemed to fail. Termination of cell production from Rhdim cells did not occur in nonirradiated LTBMC from W41/Wv mice. During peak nonadherent cell production, 25% to 30% of the cells in the nonirradiated LTBMC from W41/Wv mice had donor cell markers. Two approaches were tested to try to enhance the proportion or number of donor cells. Addition of Origen-HGF at the time of seeding Rhdim cells caused a nonspecific increase in both host and donor cell production, but a specific increase in production of donor cells was obtained by seeding the cultures at 2 weeks rather than 6 weeks. Limiting dilution of Rhdim cells gave the same frequency of wells producing cells on both irradiated +/+ and nonirradiated W41/Wv or W/Wv cultures.     

Exotic and indigenous problem plants species used,by the Bapedi,to treat sexually transmitted infections in Limpopo Province,South Africa

Background

The ethnic usage of exotics and indigenous problem plants is a highly debated topic, as legislative requirements over-shadow their potential medicinal value, particularly to treat sexually transmitted infections (STIs). Limited information exists regarding their medicinal value among the Bapedi.

Objectives

To ascertain the importance of exotics and indigenous problem plants in the treatment of STIs, a major global primary health care challenge.

Methods

A field observation and semi-structured questionnaire focussing on species diversity, types of STIs treated and medicinal preparation as well as application was used to collect data from 34 traditional healers.

Results

Seven exotics and three indigenous problem species were identified. These species were used to treat four STIs; with Catharanthus roseus illustrating its dominance in the treatment of gonorrhoea. Some medicinal species used by Bapedi traditional healers have been validated through scientific research or through their extensive use by various cultures in South Africa and other parts of Africa. To the best of our knowledge Alternanthera pungens, Caesalpinia decapetala, Cinnamomum verum, and Citrullus lanatus are reported for the first time in the treatment of the investigated STIs.

Conclusions

Exotic and indigenous problem species constitute an important component of the STIs treatment protocol. Their utilization by Bapedi cautions against the narrow-minded approach of indiscriminate eradication, as these species can play a significant role in the primary health care needs of socio-economic vulnerable people.