特发性血小板减少性紫癜患儿血清微小病毒检测

目的 :探讨人微小病毒B19(HPVB19)感染与儿童特发性血小板减少性紫癜 (ITP)发病的关系。方法 :采用聚合酶链反应 (PCR)技术对 4 8例ITP患儿和 32例健康儿童的血清标本进行HPVB19-DNA检测 ,并用酶联免疫法 (ELISA)检测血小板相关抗体。结果 :4 8例ITP患儿血清中HPVB19-DNA阳性率 37.5 % (18/48) ,32例健康儿童HPVB19-DNA均为阴性 ,2组间差异有统计学意义 (P <0 .0 0 5 ) ;ITP组中急性型与慢性型之间HPVB19阳性率差异有统计学意义 (P <0 .0 1) ;病毒感染阳性患儿的血小板相关抗体明显高于病毒感染阴性患儿 ,差异有统计学意义(P <0 .0 1)。结论 :ITP患儿血清中HPVB19-DNA阳性率高 ,尤其是急性型 ;HPVB19感染可导致血小板相关抗体升高而致血小板减少     

Successful treatment of severe refractory idiopathic thrombocytopenic purpura with liposomal doxorubicin

Idiopathic thrombocytopenic purpura (ITP) is refractory to initial treatment (steroids and splenectomy) in 25 to 30% of patients. These patients have a significant risk of fatal hemorrhage. Two patients with ITP refractory to multiple interventions and severe depression of platelet counts responded to treatment with liposomal doxorubicin with a return of platelet counts to normal. The drug is easily administered and was well tolerated. Use of this drug in refractory ITP merits further study. Am. J. Hematol. 57:85–86, 1998. © 1998 Wiley-Liss, Inc.     

Magnetic resonance imaging of reticulo-endothelial system in patients with idiopathic thrombocytopenic purpura

Idiopathic thrombocytopenic purpura (ITP) is characterized by accelerated platelet destruction in the reticulo-endothelial system (RES). We performed magnetic resonance imaging (MRI) to estimate the degree of activated RES. MRI was performed with a Gyroscan S-15 (1.5 tesla) in 7 healthy volunteers and 22 patients with ITP. The 22 patients included 19 who were at initial diagnosis or were nonresponders to the therapy (non-DX group), and 3 who were responders. For the non-DX group, the T1 relaxation time of the spleen was initially significantly shorter than for healthy volunteers, but normalized after responding to the therapy. The initially shorter T1 values of the spleen for ITP patients correlated with a low platelet count (P < 0.05). This condition may indicate foam cells or fatty components due to platelet destruction. There was no significant relationship between the sequestration in ¹¹¹In-scan and T1 values of the liver or spleen. However, MRI is a noninvasive method, and it may be a clinically useful tool in the evaluation of RES in patients with ITP. Am. J. Hematol. 56:52–58, 1997. © 1997 Wiley-Liss, Inc.     

中西医结合治疗特发性血小板减少性紫癜60例临床观察

目的观察中西医结合治疗特发性血小板减少性紫癜的临床疗效。方法将60例患者随机分为2组,治疗组33例,对照组27例,两组均给予强的松1mg／（kg·d）,分次或顿服,病情严重者用等效量地塞米松或甲泼尼龙静滴,好转后改口服,待血小板升至正常或接近正常逐步减量（每周减5mg）,以5-10mg／d维持,持续3-6月。同时配合对症支持疗法,防治感染。血小板太低,有自发出血倾象的用丙种球蛋白或输血小板,病情重者加用长春新碱1mg静脉注射,每周1次,4-6周为1疗程。治疗组在此基础上加用健脾活血为主,兼以清热凉血、滋阴降火、益气温阳等中药汤剂,有效时逐渐减少西药的用量及疗程。结果：治疗组血小板上升优于对照组,（p〈0．05）,总有效率治疗组为90．9％,对照组为77．7％,两组总疗效比较,有显著性差异（P〈0．05）．结论中医西结合治疗特发性血小板减少性紫癜比单用西药疗效显著。     

Effect of steroids on the activation status of platelets in patients with Immune thrombocytopenia (ITP)

The activation status of platelets in Immune Thrombocytopenia (ITP) patients – which is still somewhat controversial – is of potential interest, because activated platelets tend to aggregate (leading to excessive clotting or thromboembolic events) but cannot do so when platelet numbers are low, as in ITP. Although corticosteroids are the first line of therapy in ITP, the effect of steroids on activation of platelets has not been evaluated so far. We examined the status of platelet activation (with and without stimulation with ADP) in ITP patients, at the start of therapy (pre-steroid treatment, naive) and post-steroid treatment (classified on the basis of steroid responsiveness). We used flow cytometry to evaluate the levels of expression of P-selectin, and PAC-1 binding to platelets of 55 ITP patients and a similar number of healthy controls, treated with and without ADP. We found that platelets in ITP patients exist in an activated state. In patients who are responsive to steroids, the treatment reverses this situation. Also, the fold activation of platelets upon treatment with ADP is more in healthy controls than in ITP patients; treatment with steroids causes platelets in steroid-responsive patients to become more responsive to ADP-activation, similar to healthy controls. Thus steroids may cause changes in the ability of platelets to get activated with an agonist like ADP. Our results provide new insights into how, and why, steroid therapy helps in the treatment of ITP.     

联合使用免疫抑制剂对难治性ITP患者巨核细胞相关IgG水平影响及疗效分析

目的：探讨联合使用免疫抑制剂对难治性 ITP 患者巨核细胞相关 IgG 水平的影响及疗效。方法将18例难治性 ITP 患者随机分为联合治疗组和单药治疗组。联合治疗组先予2至3种静脉药物治疗3～5d,血小板值上升后联合使用2至3种不同组合的免疫抑制剂;单药治疗组先予甲基强的松龙或静脉免疫球蛋白滴注3～5d,血小板值上升后单用一种免疫抑制剂治疗。维持治疗3～6个月,随访4～24个月。运用免疫荧光法观察上述对象治疗前后巨核细胞相关IgG 情况。结果两组对象治疗后巨核细胞相关 IgG 水平均明显降低,且联合治疗组明显低于单药治疗组,差异有统计学意义（P 〈0.05）;联合治疗组总有效率88.9%,高于对照组的33.3%,差异有统计学意义（P 〈0.05）。结论联合使用免疫抑制剂对难治性 ITP 患者巨核细胞相关抗体水平有明显降低作用,同时能取得较好的临床疗效。     

VP方案治疗难治性ITP20例

目的研究VP方案治疗难治性ITP的治疗效果。方法用长春新碱、强的松组成VP方案治疗难治性特发性血小板减少性紫癜20例。结果其中显效8例,良效5例,进步6例,无效1例,有效率65%。结论 VP方案治疗难治性ITP疗效确切,无严重副作用,值得推广应用。     

H‐Phosphonic Acid Derivatives as Catalysts for Reversible Chain Transfer Catalyzed Polymerization (RTCP) at Ambient and High Pressure

Several H‐phosphonic acid derivatives (PADs) were analyzed regarding their ability to perform as effective catalysts in reversible chain transfer catalyzed polymerization (RTCP), a relatively new type of controlled radical polymerization. Therefore, bulk polymerizations of styrene at 100 °C using different PADs were studied in detail. The obtained number‐average molar masses and polydispersities of the polymeric products showed that a cyclic PAD derived from pinacol was found to be a very well suited catalyst for RTCP under the chosen conditions. In addition, RTCPs at high pressure up to 2000 bar were conducted indicating poor molar mass control compared to the systems at ambient pressure.

     

Bayesian indirect and mixed treatment comparisons across longitudinal time points

Meta‐analysis has become an acceptable and powerful tool for pooling quantitative results from multiple studies addressing the same question. It estimates the effect difference between two treatments when they have been compared head‐to‐head. However, limitations occur when there are more than two treatments of interest, and some of them have not been compared in the same study. Indirect and mixed treatment modeling extends meta‐analysis methods to enable data from different treatments and trials to be synthesized, without requiring head‐to‐head comparisons among all treatments; thus, allowing different treatments to be compared. Traditional indirect and mixed treatment comparison methods consider a single endpoint for each trial. We extend the current methods and propose a Bayesian indirect and mixed treatment comparison longitudinal model that incorporates multiple time points and allows indirect comparisons of treatment effects across different longitudinal studies. The proposed model only uses summary level longitudinal data. This model is particularly useful when a meta‐analysis is performed on studies with different durations. It enables the borrowing of information from shorter studies even in the situation where the primary interest is in a time point beyond the duration of some of these shorter studies. We performed simulation studies, which demonstrate that the proposed method performs well and yields better estimations compared with other single time point meta‐analysis methods. We apply our method to a set of studies from patients with type 2 diabetes. Copyright © 2012 John Wiley & Sons, Ltd.