病毒性肝炎患者血小板减少与脾脏肿大和血小板生成素的关系

目的研究病毒性肝炎患者血小板减少、脾脏肿大及血清血小板生成素(TPO)水平之间的关系,以探讨病毒性肝炎患者血小板减少的发病机制。方法应用腹部彩色B超测量58例病毒性肝炎并血小板减少症患者(A组)以及48例病毒性肝炎血小板正常患者(B组)和20例健康志愿者(C组)的脾脏大小,并采用酶联免疫吸附法测定其血清TPO水平。结果A组脾脏厚度(50.49±13.58mm)明显大于B组(38.45±8.14mm,P<0.01)和C组(32.25±3.73mm,P<0.01)。血小板数与脾脏大小呈负相关(r=-0.553,P<0.01)。血清TPO水平A组(88.05±17.09pg/mL)明显低于B组(100.20±17.63pg/mL,P<0.01)和C组(108.96±25.90pg/mL,P<0.01)。血小板数与血清TPO水平呈正相关(r=0.407,P<0.01)。结论病毒性肝炎血小板减少与脾脏肿大、血清TPO水平下降有关。     

Serial cloning of pigs by somatic cell nuclear transfer: restoration of phenotypic normality during serial cloning.

Somatic cell nuclear transfer (scNT) is a useful way to create cloned animals. However, scNT clones exhibit high levels of phenotypic instability. This instability may be due to epigenetic reprogramming and/or genomic damage in the donor cells. To test this, we produced transgenic pig fibroblasts harboring the truncated human thrombopoietin (hTPO) gene and used them as donor cells in scNT to produce first-generation (G1) cloned piglets. In this study, 2,818 scNT embryos were transferred to 11 recipients and five G1 piglets were obtained. Among them, a clone had a dimorphic facial appearance with severe hypertelorism and a broad prominent nasal bridge. The other clones looked normal. Second-generation (G2) scNT piglets were then produced using ear cells from a G1 piglet that had an abnormal nose phenotype. We reasoned that, if the phenotypic abnormality of the G1 clone was not present in the G2 and third-generation (G3) clones, or was absent in the G2 clones but reappeared in the G3 clones, the phenotypic instability of the G1 clone could be attributed to faulty epigenetic reprogramming rather than to inherent/accidental genomic damage to the donor cells. Blastocyst rates, cell numbers in blastocyst, pregnancy rates, term placenta weight and ponderal index, and birth weight between G1 and G2 clones did not differ, but were significantly (P < 0.05) lower than control age- and sex-matched piglets. Next, we analyzed global methylation changes during development of the preimplantation embryos reconstructed by donor cells used for the production of G1 and G2 clones and could not find any significant differences in the methylation patterns between G1 and G2 clones. Indeed, we failed to detect the phenotypic abnormality in the G2 and G3 clones. Thus, the phenotypic abnormality of the G1 clone is likely to be due to epigenetic dysregulation. Additional observations then suggested that expression of the hTPO gene in the transgenic clones did not appear to be the cause of the phenotypic abnormality in the G1 clones and that the abnormality was acquired by only a few of the G1 clone's cells during its gestational development.     

Isolation of endothelial progenitor cells from cord blood and induction of differentiation by ex vivo expansion

Endothelial progenitor cells (EPCs) have been reported to possess the capacity to colonize vascular grafts and hold promise for therapeutic neovascularization. However, limited quantities of EPCs have been the major factor impeding effective research on vasculoangiogenesis. In this study, cytokine and culture conditions necessary for the provision of large quantities of endothelial cells (ECs) were investigated. Cord blood was collected from 18 normal full-term deliveries and CD34+ cells were isolated by MACS system (Miltenyi Biotech, Bergish-Gladbach, Germany). To evaluate the effect of cytokines, CD34+ cells were cultured with various cytokine combinations, such as stem cell factor (SCF), flt3-ligand (FL), and thrombopoietin (TPO) with vascular endothelial growth factor (VEGF), interleukin-1 beta , fibroblast growth factor-basic (FGF-b) as basic cytokines. The quantities of non-adherent and adherent cells were the greatest with SCF, FL and TPO. The addition of TPO to all other cytokines significantly increased the number of non-adherent and adherent cells (p< 0.05, Wilcoxon rank sum test). After four weeks of culture, adherent cells expressed endothelial specific markers such as KDR, CD31 and CD62E. Typical morphology of ECs was observed during culture, such as cord-like structure and cobblestone appearance, suggesting that the adherent cells were consistent with ECs. In this study, the experimental conditions that optimize the production of ECs for therapeutic neovascularization were described. And it was possibly suggested that TPO plays a major role in differentiation from EPCs to ECs.     

Thrombopoietin receptor agonist switch in children with persistent and chronic severe immune thrombocytopenia: A retrospective analysis in a large tertiary center

We retrospectively analyzed sequential therapy with romiplostim and eltrombopag in 23 children with immune thrombocytopenia: switching from romiplostim to eltrombopag (10 patients) or vice versa (13 patients). The median age of patients at enrollment in the study was 5.6 years (2‐15 years). Switching from romiplostim to eltrombopag was effective in eight (80%) patients, whereas switching from eltrombopag to romiplostim was effective in eight (62%) patients. The response rate was similar in patients failing the first thrombopoietin receptor agonist and those who had previous response. To date, all responders continue to maintain platelets over 50 × 10⁹/L at 13‐39 months after switching.     

重组人血小板生成素预防吉西他滨化疗相关血小板减少症的临床观察

目的：观察重组人血小板生成素（rhTPO）对吉西他滨相关血小板减少症（CIT）的预防作用。方法选择采用含吉西他滨化疗方案治疗出现Ⅱ级及以上血小板减少的恶性肿瘤患者74例,随机分为预防性注射重组人血小板生成素组（rhTPO组）和预防性注射重组人白细胞介素-11组（rhIL-11组）,在化疗的d3、d5、d7、d9,对rhTPO组和rhIL-11组患者分别进行皮下注射rhTPO和rhIL-11治疗,观察两组患者血小板下降情况、血小板开始恢复时间、血小板输注次数、治疗延迟及不良反应情况。结果预防性治疗后,两组患者血小板下降程度均较本组治疗前有改善,且rhTPO组患者Ⅲ~Ⅳ级血小板下降比例较rhIL-11组患者减少（P﹤0.05）;rhTPO组患者血小板开始恢复时间明显较rhIL-11组提前（P﹤0.01）;rhTPO组患者d8延迟、下周期（d22）延迟及心律失常发生率均较rhIL-11组降低（P﹤0.05）。结论预防性应用rhTPO和rhIL-11对CIT有积极的预防作用,rhTPO的疗效优于rhIL-11,且不良反应较轻。     

重组人血小板生成素与白介素-11治疗白血病化疗后血小板减少症的疗效比较

目的 以重组人白介素-11(rhIL-11)为对照评价重组人血小板生成素(rhTPO)治疗白血病化疗后血小板(PLT)减少症的疗效和安全性.方法 69例白血病患者随机分为治疗组与对照组,分别皮下注射rhTPO、rhIL-11,观察外周血小板变化.结果 治疗组血小板的最低值和恢复的最高值均显著高于对照组;治疗组的血小板<50×109L-1的持续时间、恢复至70×109L-1和100 ×109L-1所需的时间,均显著低于对照组;治疗组的不良反应较轻微.结论 重组人血小板生成素治疗白血病化疗后血小板减少症疗效显著,安全性好.