Comparing the efficacy of efavirenz and boosted lopinavir using viremia copy-years

Introduction

HIV-1 plasma viral load during treatment can be highly variable. Thus, there is the need to find a measure of cumulative viremia that can be used to assess both the short- and long-term efficacy of highly active antiretroviral therapy (HAART). Here, we validate a measure of cumulative viremia to evaluate HAART efficacy.

Methods

We accessed HAART efficacy using data from a randomized clinical trial conducted in Mexico. We compared the proportion of individuals achieving a viral load <50 and <400 copies/mL at week 48, against the cumulative plasma viral load, estimated as the area under the plasma viral load curve (AUVLC). High AUVLC indicates high cumulative viremia.

Results and discussion

There was a strong and significant association between the proportion of individuals achieving a viral load <50 and <400 copies/mL at week 48, with individuals suppressed having significant lower cumulative viremia. The median area was 7513 (25th–75th percentile [Q1–Q3] 6634−8180) if viral load <50 copies/mL and 7679 (Q1–Q3 6899−9373) if viral load ≥50 copies/mL (p-value 0.0284). When the analysis was stratified by study arm, individuals on efavirenz had lower cumulative viremia than those on boosted lopinavir.

Conclusions

Our findings suggest that cumulative viremia should be explored further as a tool to simultaneously evaluate the individual and public health efficacy of HAART. This is particularly relevant to the implementation and evaluation of the Treatment 2.0 strategy recently proposed by UNAIDS and the WHO, as a means to maximize the individual and public health benefit of HAART.     

Large-scale expansion of human stem and progenitor cells from bone marrow mononuclear cells in continuous perfusion cultures

There is a growing consensus that clinical practice in the areas of bone marrow (BM) transplantation and gene therapy will rely on the ex vivo expansion of hematopoietic cells. We report here on the development of continuously perfused culture systems (bioreactor systems) that expand human stem and progenitor cells from BM mononuclear cell (MNC) populations obtained without cell enrichment. In three separate experiments, 10 bioreactors were each inoculated with 3 x 10(7) BM MNC from patients undergoing marrow harvest for autologous transplantation. At various times thereafter (between days 6 and 16), duplicate bioreactors were harvested and cells were analyzed. The bioreactors contained three cell populations that were analyzed separately: nonadherent cells; cells that were loosely adherent to the endogenously formed stromal layer; and an adherent cell layer that required trypsinization for removal. Total cell numbers increased continuously to give an overall 10-fold (range, 8- to 11-fold) expansion by day 14. The adherent stromal layer significantly expanded to more than 2 x 10(7) cells, but remained less than 6% of the total cell population. Colony-forming unit-granulocyte-macrophage (CFU-GM) numbers expanded 21-fold (range, 12- to 34-fold) by day 14 and, because this expansion was greater than that for total cells, CFU-GM were enriched by as much as fourfold by day 14. Burst-forming unit-erythroid (BFU-E) numbers peaked earlier than did CFU-GM numbers, with a 12-fold (range, 6- to 18-fold) expansion obtained on day 8. In contrast to CFU- GM, which were predominantly nonadherent, BFU-E were more evenly distributed between the three cell populations. Stem cell activity was measured by the long-term culture-initiating cell (LTC-IC) limiting dilution assay. The number of LTC-IC per reactor consistently increased with time in all cultures, resulting in a 7.5-fold (range, 3.4- to 9.8- fold) expansion. In summary, more than 3 billion cells, containing 12 million CFU-GM, were reproducibly generated from the equivalent of a 10 to 15 ml BM aspirate. These data indicate that small numbers of BM MNC can be readily expanded ex vivo in continuous perfusion cultures, and that such ex vivo expansion may have direct applications in clinical and experimental BM transplantation.     

高+Gx对猴肝细胞c-fos表达的影响

目的:观察航天应急返回过程中高正加速度( Gx)对肝脏细胞c-fos基因表达的影响．方法:选用♂猕猴(共9只)为对象,随机分为4组,对照组承受 1Gx,300 s的超重作用;实验组根据承受过载峰值的大小分为3个亚组,其承受过载峰值分别为 15Gx,200 s; 18Gx, 165 s; 21Gx,140 s．观察高 Gx对猴肝脏细胞c-fos基因表达的影响．结果:实验组肝脏细胞胞质呈现不同程度的水肿及泡状变性,c-fos基因表达明显增强,呈弥漫性细胞质内棕黄色着色;肝细胞c-fos基因表达程度随超重剂量的增加有增强趋势．对照组肝脏组织病理学改变程度明显较实验组轻微,c-fos基因表达亦明显减弱．结论: Gx可引起猴肝脏组织细胞c-fos基因表达增强,提示有早期肝脏组织损伤．     

Screening with monoclonal anti-Fy3 to provide blood for phenotype- matched transfusions for patients with sickle cell disease

BACKGROUND: In the United States, there is a shortage of blood group phenotype-matched red cells (RBCs) for patients with sickle cell disease (SCD). A protocol designed to supply phenotype-matched RBCs for these patients by combining the recruitment of African American blood donors and automated testing of RBCs for these patients for the presumptive Fy(a-b-) phenotype using monoclonal anti-Fy3 was evaluated. STUDY DESIGN AND METHODS: African American donors were recruited, to increase the likelihood of phenotype matches in the donor population. Samples of RBCs were tested for the presumptive Fy(a-b-) phenotype by using monoclonal anti-Fy3 and an automated blood typing analyzer. RBCs confirmed to be Fy(a-b-) were retyped for selected Rh, MNS, Kell, Duffy, and Kidd blood system antigens. The extended phenotypes were matched with those of 41 SCD patients requiring transfusions. RESULTS: Of 8323 blood donations during the study, approximately 40 percent (3329) were made by African Americans. Approximately 22 percent (737) of African Americans were identified as Fy(a-b-) by this protocol and 12 percent (410) were phenotype matches for the 41 SCD patients. CONCLUSION: Combining the recruitment of African American blood donors and automated phenotyping using monoclonal anti-Fy3 offers a practical, relatively low-cost strategy for supplying phenotype-matched RBCs for SCD patients. This protocol increases the options for addressing the shortage of phenotype-matched RBCs for SCD patients.     

Dopamine-Dependent Inhibition of Glycine Release in the Nucleus Accumbens of the Rat Brain during Food Consumption

Studies of Sprague-Dawley rats using in vivo intracerebral dialysis and high-performance liquid chromatography with electrochemical detection were used to investigate glycine release into the intercellular space of the nucleus accumbens during food consumption. The results showed that food consumption led to decreases in glycine levels in the intercellular space of the nucleus accumbens. Administration of the sodium channel blocker tetrodotoxin (1 M), but not the glutamate reuptake blocker D,L-threo--hydroxyaspartate (1 mM), prevented the food-related behavior-induced decrease in glycine levels in the nucleus accumbens. Eating of food after administration of the dopamine D2 receptor blocker raclopride (10 M) into the nucleus accumbens was accompanied by an increase in the glycine level in the intercellular space of this structure. These data provide evidence for the neural regulation of glycine release in the nucleus accumbens during food-related behavior, mediated via dopamine D2 receptors.     

Enhanced translocation of single DNA molecules through α-hemolysin nanopores by manipulation of internal charge

Both protein and solid-state nanopores are under intense investigation for the analysis of nucleic acids. A crucial advantage of protein nanopores is that site-directed mutagenesis permits precise tuning of their properties. Here, by augmenting the internal positive charge within the α-hemolysin pore and varying its distribution, we increase the frequency of translocation of a 92-nt single-stranded DNA through the pore at +120 mV by ≈10-fold over the wild-type protein and dramatically lower the voltage threshold at which translocation occurs, e.g., by 50 mV for 1 event·s⁻¹·μM⁻¹. Further, events in which DNA enters the pore, but is not immediately translocated, are almost eliminated. These experiments provide a basis for improved nucleic acid analysis with protein nanopores, which might be translated to solid-state nanopores by using chemical surface modification.     

Lysine-based dendrimer with double arginine residues

Due to their well-defined structure, multivalency, biocompatibility, and low toxicity, lysine dendrimers can be used as safe and efficient nanocarriers for drug and gene delivery. One useful strategy for improving the gene delivery properties of dendrimers is modification with arginine amino acid (Arg) residues. Incorporation of Arg residues could be favorable for the enhancement in transfection efficiency of lysine based dendrimers. In this work, we have synthesized a new second-generation poly-l-lysine dendrimer with repeating units containing two linear Arg residues between neighboring lysine branching points (Lys-2Arg dendrimer) and studied its physicochemical properties. We confirmed the structure of Lys-2Arg dendrimer using various one- and two-dimensional ¹H and ¹³C NMR spectroscopy methods. Comparison of T_1H relaxation data for Lys-2Arg and Lys-2Lys dendrimers showed that the replacement of double Lys residues with double Arg residues resulted in a sharp decrease in the mobility of methylene groups in side segments and in the main chain of ε-Lys inner segments. We suggest that this unexpected effect is caused by a guanidine–guanidine pairing effect in water, which leads to entanglements between dendrimer branches.

A new poly-l-lysine dendrimer with arginine residues was synthesized and its structure and physical–chemical properties were analyzed by NMR spectroscopy.     

血管紧张素原基因5''''端启动子区A-20C和A-6G单核苷酸多态性与蒙古族人群原发性高血压的相关性

目的分析血管紧张素原基因启动子区A-20C和A-6G单核苷酸多态性与蒙古族人群原发性高血压的相关性.方法实验于2005-08/2006-01在北京华大实验室完成.选取对象均为生活在内蒙古乌拉特后旗的蒙古族牧民,三代血亲内无其他民族.采用基因测序技术对内蒙古蒙古族人群中107例原发性高血压患者和108例正常对照者进行A-20C和A-6G基因分型,观察高血压组和正常对照组不同基因型的分布和等位基因频率的差异.结果①两组受试者在性别、年龄及吸烟、饮酒、体质量指数和l临床化验检查指标有较好的匹配(P均＞0.05).②两组血管紧张素原基因A-20C位点AA,AC,CC基因型频率比较差异无显著性意义(高血压组分别为0.51,0.29,0.20;正常对照组分别为0.49,0.28,0.23,x2=0.395,P=0.529).A,C等位基因频率比较差异无显著性意义(高血压组分别为0.65,0.35;正常对照组分别为0.63,0.37,x2=0.015,P=0.904).③两组血管紧张素原基因A-6G位点AA,AG,GG基因型频率比较差异无显著性意义(高血压组分别为0.50,0.33,0.17;正常对照组分别为0.55,0.34,0.11,x2=1.924,P=0.165).A,G等位基因频率比较差异无显著性意义(高血压组分别为0.66,0.34;正常对照组分别为0.72,0.28,x2=1.728,P=0.189).④高血压组协同存在血管紧张素原基因A-20C基因型CC时,血管紧张素原基因A-6G基因型GG频率稍高于正常对照组,但差异无显著性意义(x2=2.395,P=0.122,OR=7.52,95%CI 0.014～1.250),高血压组G等位基因明显高于正常对照组(分别为0.37,0.22,x2=4.658,P=0.034),携带该等位基因的蒙古族人群发生原发性高血压的相对危险度升高(OR=2.80,95%CI.087～7.271).结论血管紧张素原基因A-20C和A-6G单核苷酸多态性与蒙古族人群原发性高血压相关,并可能具有协同作用.     

等离子体处理胶原锚定PLGA/脱细胞骨基质骨软骨双层支架材料的制备和评估

目的:分别以胶原锚定方法修饰的聚乳酸-聚羟基乙酸共聚物(PLGA)为组织工程软骨支架材料,以脱细胞骨基质为组织工程骨支架材料,将二者结合制备出结合良好的组织工程骨软骨双层支架,并观察结构特征,以评估其作为组织工程化骨软骨复合体支架材料的可行性。方法:实验于2006-02/2007-02在解放军总医院骨科研究所完成。①支架的制备:以犬新鲜松质骨为原料,制备脱细胞骨基质作为骨支架材料;将脱细胞骨基质浸于盛有PLGA溶液的模具中,采用固-液相分离法结合致孔剂溶出法制备出多孔的PLGA/脱细胞骨基质双层支架,然后对PLGA支架部分进行等离子体处理和Ⅰ型胶原锚定修饰。得到的新型组织工程骨软骨双层支架的上层为多孔PLGA,下层为脱细胞骨基质。②支架的特征观察:对支架行扫描电镜检测,并采用乙醇置换法测定PLGA层孔隙率,采用北京亚林公司提供的扫描电镜图像分析系统测定PLGA层支架的平均孔径。结果:扫描电镜显示双层支架的PLGA部分具有良好的孔隙贯通结构,孔径为(211±33)μm,孔隙率为(95.0±1.5)%;脱细胞骨基质骨支架部分具有天然骨的孔径和空隙率;PLGA材料渗入骨支架部分,双层支架结合良好。结论:等离子体处理后胶原锚定修饰的PLGA/脱细胞骨基质双层支架具有良好的结构和孔隙率,结合良好,可作为支架载体应用于组织工程骨软骨复合体的构建。