Capillary zone electrophoresis and MALDI-mass spectrometry for the monitoring of in vitro O-glycosylation of a threonine/serine-rich MUC5AC hexadecapeptide.

The in vitro N-acetylgalactosaminylation by human gastric UDP-GalNAc:polypeptide N-acetylgalactosaminyltransferases was assessed using the peptide motif GTTPSPVPTTSTTSAP, which is found naturally in the tandem repeat domains of the apomucin encoded by the gene MUC5AC. This peptide appeared to be an excellent tool for obtaining an insight into the extensive O-glycosylation processes of apomucins. Up to six N-acetylgalactosamines were added and the given glycopeptide species were well separated by capillary zone electrophoresis. Moreover, the degree of glycosylation (number of monosaccharide O-linked attachments) could be determined by MALDI-mass spectrometry without prior separation. Using different incubation times, we evidenced the accumulation of various glycopeptides, suggesting that the total glycosylation of an apomucin-peptide requires orderly N-acetylgalactosaminylation processing. This information was completed by experimental data showing that N-acetylgalactosaminylated octapeptides (the peptide backbones of which are part of GTTPSPVPTTSTTSAP) were able to selectively inhibit some N-acetylgalactosaminyltransferases. Our results suggest that this inhibition may influence the quality of the intermediate products appearing during the in vitro O-glycosylation process.     

Femoral capital osteonecrosis: MR finding of diffuse marrow abnormalities without focal lesions

Six painful hips in five patients were examined with magnetic resonance (MR) imaging and were found to have diffuse signal abnormalities in the marrow of the femoral head and neck, which extended into the intertrochanteric area in five cases. The abnormal regions were low in signal intensity on images obtained with a short repetition time (TR) and a short echo time (TE) and were isointense or hyperintense on long TR/TE images--findings that have been attributed by others to bone marrow edema. Edema was also seen in marrow just above the acetabulum in two cases. No focal abnormalities characteristic of osteonecrosis were seen. Osteonecrosis was subsequently shown to be present in all six femoral heads at core biopsy (three cases) or by subsequent development of focal MR abnormalities reported to be highly specific for osteonecrosis (three cases). The affected hips had been radiographically normal or subtly osteopenic and had shown intense radionuclide uptake in the femoral head at scintigraphy, with lesser abnormality in the neck and intertrochanteric region. Follow-up MR examinations of five of the six femoral heads showed the diffuse abnormalities to have been transient. Although diffuse MR abnormalities in the proximal femur are not specific, they may indicate the presence of osteonecrosis of the femoral head.     

关节部位Ⅲ度烧伤削痂植皮与切痂植皮的效果比较

目的:Ⅲ度烧伤创面的处理临床上仍然以切痂植皮术治疗为主,由于切痂时切除了并未损伤的皮下脂肪组织,使其愈后外观变化明显。实验拟观察关节部位Ⅲ度烧伤削痂后于脂肪层移植大张自体中厚皮的疗效,并与切痂植皮进行比较。方法:①于2001-01/2007-06南昌大学第一附属医院烧伤科收治的关节Ⅲ度烧伤患者中抽取39例(45个关节)作为削痂组,同时抽取45例(共60个关节)作为切痂组。所有患者对治疗及实验方案均知情同意,且得到医院伦理道德委员会批准。②削痂组削痂植皮,保留正常皮下脂肪等组织。切痂组切痂植皮,切痂平面包括全层皮肤和皮下脂肪组织一并切除直至深筋膜层。削痂或切痂后植大张自体中厚皮。③创面修复后4￣6周观察两组患者的关节外观和关节活动功能;比较两组患者术后2周的植皮成活率和创面修复时间。结果:两组患者均进入结果分析。①两组患者烧伤关节创面修复后与对称的正常关节比较,削痂组外观变化不明显,周径缩小3.6%(P>0.05),功能好,关节活动度减少5.3%(P>0.05);切痂组外观变化明显,周径缩小23.4%(P<0.05),功能较差,关节活动度减少21.9%(P<0.05)。②两组患者术后2周植皮成活率和创面修复时间差异均无显著性意义(P>0.05)。结论:脂肪层移植大张自体中厚皮于Ⅲ度烧伤削痂后关节部位,能够维护肢体的美观,保护关节功能,疗效优于切痂植皮。     

紫杉醇药物涂层支架植入术后患者外周血单核细胞中热休克蛋白70的变化：生物材料临床应用近期效果随访

目的:植入材料、靶血管病变特征、术前状态、炎症因子及急性期蛋白均对急性冠状动脉综合征接受支架材料介入治疗后的效果有影响,为验证紫杉醇涂层支架临床应用后材料及宿主的相关反应,实验观察了接受紫杉醇涂层支架介入治疗的急性冠状动脉综合征患者的外周血热休克蛋白70水平变化,并分析其临床意义。方法:①连续性入选2004-12/2006-03在江苏大学附属人民医院行经皮冠状动脉介入治疗的78例急性冠状动脉综合征患者,全部病例均置入紫杉醇药物涂层支架。采用流式细胞仪测定症状发作平均(34.1±16.2)h的外周血单核细胞热休克蛋白70阳性表达水平。②所有患者随访至术后6个月,出现心源性死亡、再次心肌梗死、再发心绞痛、再次血运重建术和继发心衰等主要心脏不良事件者为近期预后不良组,无上述情况者判定为近期预后良好组,用logistic多元回归法分析术前状态、靶血管病变特征、植入支架的各项参数及外周血热休克蛋白70水平与主要心脏不良事件发生率的关系,并以同期健康体检者20例为正常对照组。结果:68例患者完成随访进入结果分析。①外周血热休克蛋白70水平:急性心肌梗死患者和不稳定型心绞痛患者比较差异无统计学意义(P>0.05),但均显著高于正常对照组(P<0.05)。②在多变量的logistic回归分析中,外周血热休克蛋白70独立于其危险因素,能预测急性冠状动脉综合征患者经皮冠状动脉介入治疗后近期主要心脏不良事件发生率(OR值为0.904,P<0.05)。结论:回归分析结果提示,应用紫杉醇涂层支架临床治疗近期效果评估中,外周血热休克蛋白70水平高的急性冠状动脉综合征患者近期心脏事件发生率较高,说明外周血热休克蛋白70可能成为判断紫杉醇涂层支架介入治疗后不良事件发生率的独立因素之一。     

A cost-effectiveness analysis of the use of a mechanical barrier system to reduce the risk of mistransfusion

BACKGROUND: A blood component is transfused to a patient other than the intended recipient because of patient and sample identification problems once in about every 24,000 transfusions. An investigation was performed of the cost-effectiveness of a barrier system to prevent mistransfusion of a unit of red cells through this kind of error. STUDY DESIGN AND METHODS: A decision analysis model was constructed that took into account nonfatal and fatal events, costs of patient care, and legal costs. The model was used to determine the cost-effectiveness of the barrier system in terms of cost per year of life saved and lives saved per million transfusions. RESULTS: The barrier system is predicted to save 1.5 lives per million transfusions when used as intended. If the cost-effectiveness calculations are based on an average damage award for a fatality of more than $725,000 and a chance of mistransfusion exceeding 1 in 16,700, use of the system results in reduced healthcare expenditures. If no legal costs are included in the cost-effectiveness calculations, use of the system costs $197,000 per year of life saved. Routine use of the system extends patient life by 1 year per 60,000 units transfused. CONCLUSION: The application of a barrier system to prevent mistransfusion and related morbidity and mortality can be cost-effective. If legal costs are included in the calculations, the use of a barrier system reduces total costs.     

组织工程化仿生人工骨修复兔桡骨节段性骨缺损

目的:观察自体骨髓基质细胞复合多孔仿生人工骨后修复节段性骨缺损的效果。方法:实验于2002-01/2003-05在解放军第四军医大学西京医院全军骨科研究所完成。①抽取成年家兔骨髓并分离、培养和诱导骨髓基质细胞。②采用纳米晶羟基磷灰石-胶原中羟基磷灰石和胶原的比例为4∶1,仿生材料中纳米晶羟基磷灰石和聚左旋乳酸的比例为1∶1;孔隙率>90%,孔径50～300μm;规格15mm×3mm×3mm材料。使用前分别经乙醇、无菌双蒸水和离心等处理。将第3代骨髓基质细胞按3×1010L-1接种于上述材料中常规培养。体外构建骨髓基质细胞和仿生基质材料复合体。③手术造成兔右桡骨干15mm骨缺损动物模型,随机分为实验组14只、对照组14只和空白组6只,实验组植入自体骨髓基质细胞/仿生材料复合体,对照组仅植入仿生材料,空白组不作任何处理。通过X射线、骨密度、组织学以及计算机图象分析等手段观察各组在不同时相的骨缺损修复情况。结果:34只兔全部进入结果分析。①骨髓基质细胞和多孔纳米晶羟基磷灰石-胶原/聚左旋乳酸材料体外复合培养结果:7d后细胞基本汇合成片,细胞表面和周围出现较多网状胶原纤维。②各组兔骨缺损区X射线检查:实验组术后24周骨缺损区密度较高,与截骨端骨性融合,接近形成正常骨干结构;对照组术后24周可见少量骨痂自截骨端向材料内长入,但未见材料表面连续性骨痂形成。空白组术后24周两截骨端硬化封闭,形成骨不连。③骨密度测定:术后16周、24周实验组骨缺损区骨密度明显高于对照组(16周:(0.152±0.041),(0.092±0.029)g/cm2,24周:(0.177±0.044),(0.113±0.026)g/cm2,t=2.67,2.80,P<0.05),而与对侧正常桡骨无明显差异。④组织学观察:实验组术后24周植入材料大部分降解并为新生骨替代,新生骨和两端皮质骨融为一体;对照组术后24周材料部分降解成颗粒状,缺损区中央为纤维组织充填,仅两端有部分新生骨组织;空白组术后24周断端封闭形成骨不连。⑤计算机图象分析:8,16,24周,实验组修复性新骨占原骨缺损面积百分数随着观察时间的延长而增加,并显著高于同一时间点对照组(t=8.971,11.240,12.836,P<0.01)。结论:①通过微创方式获取大量成骨性骨髓基质细胞,并将其与多孔纳米晶羟基磷灰石-胶原/聚左旋乳酸材料复合培养后植入骨缺损区,可以发挥多重成骨效应,从而较快地启动骨修复反应。②采用组织工程学技术修复节段性骨缺损是一条切实有效的治疗手段,有较广泛的临床应用前景。     

Antitumor vaccination using a major histocompatibility complex (MHC) class I-restricted pseudopeptide with reduced peptide bond

Synthetic peptides have raised a considerable interest in the fields of vaccines and immunotherapy. The authors previously introduced modifications into the peptide backbone of the H-2Kd-restricted epitope CW3. One of these pseudopeptides, C7, bound to Kd with an affinity identical to the parent peptide and was recognized by T cells specific for the parent peptide. The authors now show that this analog has an increased resistance to trypsin and displays an extended half-life in serum. The authors further tested its immunogenicity both in vitro and in vivo and found that cytotoxic T lymphocytes (CTL) induced against the peptide analog recognize the parent peptide. Moreover, analysis of T-cell receptor rearrangements by Immunoscope software revealed that C7-induced CTL display the hallmarks of the response against the parental epitope CW3. Administration of the pseudopeptide into DBA/2 mice induces a protective immune response against a lethal challenge with tumor cells expressing the parent peptide. Therefore, modifications in the backbone of antigenic peptides can decrease protease susceptibility while preserving immunogenicity. Such peptide analogues may therefore prove useful for the development of new therapeutic tools aimed at eradicating pathogens or tumors.     

Pharmacokinetics of perindopril and its metabolites in healthy volunteers

Perindopril, an angiotensin converting enzyme (ACE) inhibitor, is converted in vivo to its active diacid metabolite, perindoprilat and to a perindoprilat glucuronide. The pharmacokinetic parameters of perindopril, perindoprilat and perindoprilat glucuronide were evaluated after single administration to healthy volunteers (N = 12) of 8 mg of perindopril tert-butylamine salt by oral route (treatment A), by intravenous route (bolus in 5 min, treatment B) and of an equimolar dose of perindoprilat (6.1 mg) by intravenous route (infusion over 2 h, treatment C). The treatments were administered as a randomised 3-way cross-over design. Plasma samples were collected up to 96 h and urines up to 120 h. Perindopril is rapidly absorbed with an oral bioavailability of 95% and is mainly eliminated by metabolic processes. The formation of perindoprilat is slow and about 20% of the available parent drug is transformed into this metabolite. Elimination profile of perindoprilat is biphasic, with a rapid renal excretion of the free fraction and a long terminal half-life of the fraction bound to ACE. Perindoprilat glucuronide is mainly obtained from perindopril by a pre-systemic first pass metabolism.     

Predictors of One Year Outcome in Lupus Nephritis: The Importance of Renal Biopsy

The short-term prognosis of lupus nephritis was evaluated byassessing serum creatinine 12 months after renal biopsy in 87patients with lupus nephritis. On univariate analysis, significantclinical and laboratory predictors of this outcome includedclinical signs of renal injury (serum creatinine, 24-hour urinaryprotein, prolonged renal disease, nephrotic syndrome, serumalbumin), as well as thrombocytopenia, older age, and coexistingillness or hypertension at the time of biopsy. On renal biopsy,diffuse proliferative nephritis, higher activity, chronicity,or tubulointerstitial scores, or subendothelial or subepithelialelectron dense deposits predicted a higher serum creatinine12 months after biopsy. A clinical predictive model was developed which included asindependent predictors serum creatinine, age, platelet countand 24-hour urinary protein. Any one of three biopsy variablesadded information to the clinical prediction model: a markedquantity of subendothelial deposits (p=0.02), a higher activityindex score (p=0.02), or the presence of diffuse proliferativelupus nephritis (p=0.05). However, the relative predictive accuracyof the clinical model did not improve with the addition of anyof the biopsy variables. The value of renal biopsy in lupus nephritis is discussed basedon the ability of biopsy information to confirm the prognosis,to add new predictive information for a group of subjects, andto improve predictive accuracy for individual patients.