量子点技术在生物成像中的应用进展

目的：介绍量子点材料的特点及其在生物成像中的应用,并对其前景进行展望. 资料来源：应用计算机检索PubMed 1998-01/2007-04关于量子点生物成像文章.检索词“quantum dots,biological imaging,bioconjugates,fluorescence imaging”限定文章的语言种类为“English”. 资料选择：对资料进行初审,纳入标准：①量子点的特点及表面修饰.②量子点在不同的生物组织细胞中的成像应用.排除标准：重复性研究. 资料提炼：共收集到符合上述要求的文献31篇,关于量子点的特点及表面修饰的14篇,关于量子点在不同的生物组织细胞中的成像应用17篇. 资料综合：量子点（quantum dots,QDs）是一种新型纳米荧光材料,现有技术能将量子点与生物分子结合在一起作为一种高亮度而稳定的荧光探针用于生物成像.作为一种新型的荧光纳米材料量子点,在多种类型的生物成像研究中较传统的有机荧光素和荧光蛋白而言具有更加优越的特性,使研究者能够以一种全新的方法对单个细胞、组织、甚至活动物的基因、蛋白质和药物靶点进行研究,为疾病机制的阐明和临床诊疗提供有力帮助. 结论：量子点荧光标记材料具有信号稳定、标记简便、检测灵敏的优点,在生物成像中具有良好的应用前景.     

Th activation of maternal and cord blood

Th activation of red cells is characterized by agglutination with the peanut lectin from Arachis hypogaea and is diminished by treatment with proteolytic enzymes. The first cases of Th activation were associated with bacterial infections. More recently, a high incidence of Th activation in congenital hypoplastic anemia has been reported, along with the finding that 13.5 percent of cord bloods are Th activated. The incidence of Th reactivity in newborn infants was confirmed by studying 200 paired samples of maternal and cord blood. Twenty-two (11%) of the cord samples and 13 (6.5%) of the maternal samples were Th activated. In 6 paired samples (6/22), both the mother and child had Th activation, a finding that demonstrates a high degree of concordance. Additionally, 3 (6%) of 50 pregnant women were Th positive. These findings indicate that Th activation is another of the red cell antigen alterations related to pregnancy.     

High rates of early HBeAg seroconversion and relapse in Indian patients of chronic hepatitis B treated with Lamivudine: results of an open labeled trial

Background  

The use of Lamivudine in chronic hepatitis B (CHB) is well known, however the reported rate of HBeAg sero-conversion and its durability post-treatment have varied considerably. We undertook the present study to study the effect of Lamivudine on HBeAg loss and seroconversion rates in Indian patients of CHB in relation to frequency, predictors and durability.     

Variation in blood sample collection for determination of hemodialysis adequacy. Council on Renal Nutrition National Research Question Collaborative Study Group

Inadequate dialysis has been associated with high morbidity and mortality in end-stage renal disease (ESRD) patients receiving maintenance hemodialysis. The accurate estimation of dialysis adequacy, measured either as a calculated urea kinetics (Kt/V) or a simple urea reduction ratio (URR) is dependent on the proper collection of blood samples for predialysis and postdialysis blood urea nitrogen (BUN) determination. Because no established protocol exists for blood sampling, we surveyed the study cohort of dialysis centers participating in the National Kidney Foundation Council on Renal Nutrition National Research Question Collaborative Study to determine the comparability of BUN data that were collected to calculate URR to determine adequacy of dialysis. Surveys were completed by 100% of the 202 units participating: 195 in the United States (from 43 states) and seven from Canada, treating approximately 15,000 hemodialysis patients in total. The distribution of the sample by the type of facility mirrored that of 1996 United States Renal Data System (USRDS) Annual Report facilities data. Results showed a 5.0% error in predialysis blood draw and an 8.4% to 41.6% error in the postdialysis counterpart. There was a large variability in the observed postdialysis methods in general. Dilution of predialysis sample with either heparin or saline will falsely underestimate Kt/V and URR. The presence of access-derived, recirculated blood in the postdialysis sample will falsely overestimate Kt/V and URR. Excessive delay in drawing postdialysis sample will reduce Kt/V and URR because of urea rebound. Adoption by all dialysis providers of a uniform blood sample draw procedure will result in a consistency necessary to allow reliable and valid comparison of adequacy of dialysis parameters within and between ESRD patients, units, and clinical trials.