脐血间充质干细胞分离培养的理论研究与应用

目的:间充质干细胞具有多向分化潜能,在一定的实验条件控制下可分化为骨、软骨、肌肉、神经、肝和内皮等多种细胞,本文在于进一步综合分析脐血间充质干细胞的优化分离培养条件。资料来源:应用计算机检索Medline、PubMed数据库1980-01/2006-12期间有关脐血间充质干细胞分离培养的文献,检索词“mesenchymal stem cells,human umbilical cord blood(HUCB),isolation,culture”,并限定文章语言种类为English。同时计算机检索CNKI,万方数据库1990-01/2006-12期间相关文献,限定文章语言种类为中文,检索词“间充质干细胞,脐血,分离,培养”。并手工查阅相关书籍。资料选择:检索有关脐血间充质干细胞分离培养的综述和实验论据,参考综合各文献中脐血间充质干细胞培养的方法条件,选择比较典型和比较新颖的文献进行综合。资料提炼:共检索到79篇有关脐血间充质干细胞分离纯化、培养扩增的文献,纳入30篇。资料综合:国内外有大量的实验证实,间充质干细胞具有肯定的支持造血功能,而且在一定实验条件控制下可分化为骨、软骨、脂肪、肌腱、肌肉、神经、基质、肝、内皮等多种细胞。脐血来源间充质干细胞具有低免疫原性等很多优点已成为干细胞研究领域的热点,目前分离培养间充质干细胞的方法多样,日趋成熟,但仍存在许多不足,需进一步探索间充质干细胞的分离纯化技术。结论:目前已经建立了多种脐血间充质干细胞分离纯化培养扩增的方法,为其在细胞工程和组织工程的应用提供了基础。     

肾移植术后乙型肝炎病毒拉米夫定耐药的治疗

目的:观察肾移植术后乙型肝炎病毒患者发生拉米夫定耐药后,应用新一代核苷类抗乙型肝炎病毒药物阿德福韦和恩替卡韦的治疗效果。方法:选择2001-05/2006-09于南方医科大学南方医院器官移植科就诊的乙型肝炎病毒感染并发生病毒多聚酶催化域YMDD基序变异,对拉米夫定耐药的肾移植患者4例,患者均知情同意。定期复查血清丙氨酸转氨酶、天冬氨酸转氨酶、总胆红素、乙型肝炎病毒DNA定量及乙型肝炎病毒YMDD变异情况,先后采用拉米夫定、阿德福韦及恩替卡韦进行治疗,并观察其治疗效果。结果:①4例患者分别随访16,26,63,67个月,移植肾功能良好。②4例患者分别在服用拉米夫定14,24,51和62个月(术后12个月)时出现乙型肝炎病毒YMDD变异,乙型肝炎病毒DNA升高至105～109拷贝/mL,肝功能异常。2例加用阿德福韦3个月后撤除拉米夫定,单用阿德福韦治疗,乙型肝炎病毒DNA均降为104拷贝/mL,肝功能正常,其中1例单用阿德福韦9个月后乙型肝炎病毒YMDD变异转阴,另1例单用阿德福韦2个月,乙型肝炎病毒YMDD变异仍为阳性;2例停用拉米夫定,直接换为恩替卡韦,其中1例2个月后肝功能正常,乙型肝炎病毒DNA阴性,乙型肝炎病毒YMDD变异阴性,另1例服药2个月后肝功能正常,乙型肝炎病毒DNA降为104拷贝/mL,乙型肝炎病毒YMDD变异仍为阳性。结论:新型抗乙型肝炎病毒药物阿德福韦和恩替卡韦可有效抑制拉米夫定耐药的乙型肝炎病毒复制,有利于乙型肝炎病毒阳性肾移植患者长期存活。     

Differential effects of airway anesthesia on ozone-induced pulmonary responses in human subjects

We examined the effect of tetracaine aerosol inhalation, a local anesthetic, on lung volume decrements, rapid shallow breathing, and subjective symptoms of breathing discomfort induced by the acute inhalation of 0.30 ppm ozone for 65 min in 22 ozone-sensitive healthy human subjects. After 50 min of ozone inhalation FEV(1) was reduced 24%, breathing frequency was increased 40%, tidal volume was decreased 31%, and total subjective symptom score was increased (71.2, compared with 3.8 for filtered air exposure). Inhalation of tetracaine aerosol resulted in marked reductions in ozone-induced subjective symptoms of throat tickle and/or irritation (92.1%), cough (78.5%), shortness of breath (72.5%), and pain on deep inspiration (69.4%). In contrast, inhalation of tetracaine aerosol (mass median aerodynamic diameter of 3.52 microm with a geometric standard deviation of 1.92) resulted in only minor and inconsistent rectification of FEV(1) decrements (5.0%) and breathing frequency (-3.8%) that was not significantly different from that produced by saline aerosol alone (FEV(1), 5.1% and breathing frequency, -2.7%). Our data are consistent with afferent endings located within the large conducting airways of the tracheobronchial tree being primarily responsible for ozone-induced subjective symptoms and provides strong evidence that ozone-induced inhibition of maximal inspiratory effort is not dependent on conscious sensations of inspiratory discomfort.     

Carpal avascular necrosis: MR imaging

The authors evaluated the use of magnetic resonance (MR) imaging in diagnosis of avascular necrosis (AVN) of carpal bones by examining 21 patients with wrist pain and two healthy volunteers. MR images were compared with conventional radiographs in every case and with bone scintigrams in 18 cases. MR imaging was slightly less sensitive than bone scintigraphy in depicting AVN, but in patients who were imaged with long repetition time (TR)/long echo time (TE) sequences in addition to short TR/short TE sequences, MR imaging was found to be more specific. While the authors believe that bone scintigraphy remains the screening test of choice for patients with wrist pain and normal plain radiographs, MR imaging promises to add significant diagnostic information in cases in which bone scans are abnormal.     

Spinal cord compression by amyloid tissue

Spinal cord compression by a mass of amyloid tissue arising from the thoracic vertebrae is described in a 72-year-old female. Investigations failed to provide a primary cause for this amyloid tissue.     

Graphical method for comparative statistical study of vaccine potency tests

Producers and consumers are interested in some of the intrinsic characteristics of vaccine potency assays for the comparative evaluation of suitable experimental design. A graphical method is developed which represents the precision of test results, the sensitivity of such results to changes in dosage, and the relevance of the results in the way they reflect the protection afforded in the host species. The graphs can be constructed from Producer's scores and Consumer's scores on each of the scales of test score, antigen dose and probability of protection against disease. A method for calculating these scores is suggested and illustrated for single and multiple component vaccines, for tests which do or do not employ a standard reference preparation, and for tests which employ quantitative or quantal systems of scoring.