骨髓移植诱导临床心脏移植后供者特异性免疫耐受方案的探讨

目的 探讨骨髓移植诱导临床心脏移植后供者特异性免疫耐受的可行性.方法 采取供心的同时采用改良"灌流法"获取供者的骨髓350 ml,经过滤及离心处理后,加入细胞冷冻保护液共80ml,分装于低温冻存袋,经程序降温,置于-80℃冰箱中保存.在常规原位心脏移植术后40 d,取冻存骨髓快速复温,穿刺受者双侧髂后上嵴,立即行骨髓腔内骨髓细胞输注(IBM-BMT),共输注单核细胞1.2×107/kg,CD34+细胞2.38×105/kg.骨髓输注前3 d行预处理,包括应用氟达拉滨、抗胸腺细胞球蛋白及全身淋巴结照射.骨髓移植后静脉应用他克莫司(Tac),维持血Tac浓度谷值在10～20μg/L;3周后改为口服Tac+吗替麦考酚酯(MMF);6周后改为环孢素A及MMF.分别于心脏移植后2、4、8和12周采集受者外周血,分别于术后4、8和12周采集受者的骨髓,应用短串联重复序列-聚合酶链反应法检测供者嵌合体.心脏移植后每周行心肌内心电图检查,每月行心肌活检1次.术后3个月,取受者及第三者外周血单核细胞,行混合淋巴细胞反应(MLR).结果心脏移植后1、2及3个月时受者的外周血及髂骨内骨髓细胞中供者来源的细胞比例分别为26.3%、19.1%、4.8%和46.3%、24.4%、7.6%.IBM-BMT后心肌内心电图监测显示心肌阻抗及R波波幅无明显变化.术后3个月行心内膜心肌活检,未见排斥反应征象.术后3个月时行超声心动图检查,提示心脏舒张、收缩功能良好.MLR提示受者对供者特异性刺激呈现低反应性,而对第三者仍保持良好的免疫活性(P＜0.01).结论 采取分期骨髓移植免疫耐受诱导方案可安全、有效地建立嵌合体,成功诱导心脏移植后供者特异性免疫耐受,但远期效果有待进一步研究.

Abstract：

Objective To investigate a new strategy of bone marrow transplantation (BMT) for donor-specific tolerance induction after heart transplantation. Methods Donor bone marrow cells (BMCs)were harvested simultaneously with donor cardiac graft using modified perfusion method (PM) ,then stored in a -80 ℃ refrigerator after filtration and centrifugation. Whole BMCs (IBM-BMT) (monocytes 1.2 ×107/kg,CD34+ cells 2.38× 105/kg) in host iliac bones were injected into the bone marrow cavity 40 days after heart transplantation. Preconditoning regimens that consisted of fludarabine, antithymoctye globin and total lymphoid irradiation were performed 3 days before BMT. Tacrolimus (Tac) was administrated intravenously after BMT or orally in conjunction with mycophenolate mofetil (MMF) 3 weeks later.Cyclosporine and MMF were orally administrated 6 weeks later. Donor chimerism was detected using short tandem repeats-polymerase chain reaction in monocytes from peripheral blood at the 2nd,4th, 8th or 12th week after BMT or BMCs at the 4th, 8th or 12th week after BMT. Intramyocardium electrocardiography examination or endomyocardial biopsy was performed weekly or monthly respectively. Mixed lymphocyte reactions (MLR) were performed 3 months after BMT. Results Donor chimerism in monocytes in peripheral blood or BMCs in iliac bones measured at the 1 st,2nd and 3rd month after BMT was 26.3%, 19.1%,4.8% ,and 46.3%, 24.4%, 7.6%, respectively. After 3-month follow-up, there was no rejection confirmed by endomyocardial biopsy or intramyocardium electrocardiography. Echocardiography revealed that the diastolic and systolic function of the cardiac graft was maintained well 3 months after BMT. MLR revealed donor-specific hyporesponsiveness while immunocompetence was preserved to third-party antigens. Conclusion These findings indicate that the two-stage BMT strategy is a safe and feasible method for the induction of donor-specific tolerance via stable mixed chimerism and needs to be further confirmed after a long-term observation.     

Determination of the median effective dose (ED50) of bupivacaine and ropivacaine unilateral spinal anesthesia

Background

Unilateral spinal anesthesia (USpA) has been reported to potentiate spinal anaesthesia and is used in geriatric patients. The purpose of this study was to determine the median effective dose (ED₅₀) of 0.5% hypobaric bupivacaine and 0.5% hypobaric ropivacaine USpA for geriatric patients (age ≥ 70 years) undergoing elective hip replacement surgery.

Methods

A total of 60 geriatric patients (age ≥ 70 years) undergoing elective hip replacement surgery were enrolled in this study. The patients were randomized into 2 groups to receive either intrathecal 0.5% hypobaric bupivacaine USpA (group B) or 0.5% hypobaric ropivacaine USpA (group R). Effective anesthesia was defined as a T10 sensory blockade level maintained for more than 60 min, and a Bromage score of 3 on the operation side within 10 min after injection with no additional epidural anesthetic required during surgery. The ED₅₀ of 0.5% hypobaric bupivacaine and 0.5% hypobaric ropivacaine was calculated using the Dixon and Massey formula.

Results

No significant differences were found between the two groups in terms of demographic data. The ED₅₀ of 0.5% hypobaric bupivacaine USpA was 4.66 mg (95% confidence interval CI 4.69–4.63 mg) mg and that of 0.5% hypobaric ropivacaine USpA was 6.43 mg (95% CI 6.47–6.39 mg) for geriatric patients undergoing hip replacement surgery.

Conclusion

We find the ED₅₀ were lower, and the ED50 of 0.5% hypobaric bupivacaine and ropivacaine was 4.66 mg (95% CI 4.69–4.63 mg) and 6.43 mg (95% CI 6.47–6.39 mg), respectively, for USpA in geriatric patients (age ≥ 70 years) undergoing elective hip replacement surgery.

     

Transplanted L1 expressing radial glia and astrocytes enhance recovery after spinal cord injury

A major obstacle for the transplantation of neural stem cells (NSCs) into the lesioned spinal cord is their predominant astrocytic differentiation after transplantation. We took advantage of this predominant astrocytic differentiation of NSCs and expressed the paradigmatic beneficial neural cell adhesion molecule L1 in radial glial cells and reactive and nonreactive astrocytes as novel cellular vehicles to express L1 under the control of the promoter for the human glial fibrillary acidic protein (GFAP-L1 NSCs). Behavioral analysis and electrophysiological H-reflex recordings revealed that mice transplanted with GFAP-L1 NSCs showed enhanced locomotor recovery in comparison to mice injected with wild type (WT) NSCs or control mice injected with phosphate-buffered saline (PBS). This functional recovery was further accelerated in mice transplanted with L1-expressing radial glial cells that had been immunoisolated from GFAP-L1 NSCs (GFAP-L1-i cells). Morphological analysis revealed that mice grafted with GFAP-L1 NSCs exhibited increased neuronal differentiation and migration of transplanted cells, as well as increased soma size and cholinergic synaptic coverage of host motoneurons and increased numbers of endogenous catecholaminergic nerve fibers caudal to the lesion site. These findings show that L1-expressing astrocytes and radial glial cells isolated from GFAP-L1 NSC cultures represent a novel strategy for improving functional recovery after spinal cord injury, encouraging the use of the human GFAP promoter to target beneficial transgene expression in transplanted stem cells.     

Comparison of the 6th and 7th Editions of the UICC TNM Staging System for Gastric Cancer: Results of a Chinese Single-Institution Study of 1,503 Patients

Aim

To evaluate the prognostic efficacy of the 7th edition tumor–node–metastasis (TNM) classification compared with the 6th edition in gastric cancer patients.

Methods

A total of 1,503 gastric cancer patients undergoing surgical resection were staged using the 6th and 7th edition staging systems. Homogeneity, discriminatory ability, and monotonicity of gradients of the two systems were compared using linear trend χ², likelihood ratio χ² statistics, and Akaike information criterion (AIC) calculations.

Results

Significant differences in 5-year survival rates were observed for the T, N, and M subgroups using the 7th edition system, except for stage N2 and N3 patients in the 6th edition system. There were no significant differences in survival between IB and IIA in the 7th edition system. Patients with stage IV disease due to T4/N3 in the 6th edition system who were downstaged to stage III in the 7th edition system had significantly better survival than those who remained at stage IV. The 7th edition system had higher linear trend and likelihood ratio χ² scores, and smaller AIC values compared with those for the 6th edition, which represented the optimum prognostic stratification.

Conclusions

Our study suggests that the 7th edition system performs better than the 6th edition in several aspects.     

高渗氯化钠对单肺通气时呼吸力学的影响

目的 探讨高渗氯化钠对单肺通气患者呼吸力学参数的影响.方法 选择拟单肺通气剖胸手术患者60例,随机均分为高渗氯化钠治疗组(H组)和对照组(C组).在单肺通气30 min后经中心静脉导管输注7.5％氯化钠溶液(H组)或生理盐水(C组)2 ml/kg.观察单肺通气前(T1)、单肺通气后30 min(T2)、输注后30 min(T3)、60 min(T4)、单肺通气结束时(T5)的动态肺顺应性(Cdyn)、气道峰压(Ppeak)、气道平均压(Pmean)、动脉血氧分压(PaO2)、血清Na+浓度.结果 与T1时比较,两组患者T2时的Cdyn、PaO2明显降低,Ppeak、Pmean明显升高(P＜0.05).与T2时比较,T3～Ts时H组Cdyn、PaO2逐渐升高,Ppeak、Pmean逐渐下降(P＜0.05),且Cdyn、PaO2明显高于C组,Ppeak明显低于C组(P＜0.05).T4、T5时H组Pmean明显低于C组(P＜0.05).结论 7.5％氯化钠溶液对单肺通气患者的各呼吸力学参数有改善作用,对肺通气功能具有保护作用.     

Tibial compression is anabolic in the adult mouse skeleton despite reduced responsiveness with aging

The ability of the skeleton to adapt to mechanical stimuli diminishes with age in diaphyseal cortical bone, making bone formation difficult for adults. However, the effect of aging on adaptation in cancellous bone, tissue which is preferentially lost with age, is not well characterized. To develop a model for early post-menopausal women and determine the effect of aging on cancellous bone adaptation in the adult mouse skeleton, in vivo tibial compression was applied to adult (26 week old) osteopenic female mice using loading parameters, peak applied load and peak diaphyseal strain magnitude, that were previously found to be osteogenic in young, growing (10 week old) mice. A Load-Matched group received the same peak applied loads (corresponding to +2100 με at the medial diaphysis of the tibia) and a Strain-Matched group received the same peak diaphyseal strains (+1200 με, requiring half the load) as the young mice. The effects of mechanical loading on bone mass and architecture in adult mice were assessed using micro-computed tomography and in vivo structural stiffness measures. Adaptation occurred only in the Load-Matched group in both the metaphyseal and diaphyseal compartments. Cancellous bone mass increased 54% through trabecular thickening, and cortical area increased 41% through medullary contraction and periosteal expansion. Adult mice were able to respond to an anabolic stimulus and recover bone mass to levels seen in growing mice; however, the adaptive response was reduced relative to that in 10 week old female mice for the same applied load. Using this osteogenic loading protocol, other factors affecting pathological bone loss can be addressed using an adult osteopenic mouse model.     

肝素标记SPIO增强MRI诊断大鼠肝癌病灶

目的:探讨肝素标记超顺磁氧化铁粒子(HepSPIO) 对大鼠肝癌灶的增强作用。材料和方法:应用Gouys 法测定磁化率;应用二乙基亚硝胺建立大鼠化学诱导性肝癌模型;观察静注Hepspio 前后大鼠肝癌的显示情况,并与病理检查对照分析。结果:HepSPIO 的磁化率为201-5 ×10 - 3/g(25 ℃) ;4 只大鼠肝癌模型共有27 个瘤结,平均直径2-4 ±1-3m m 。增强后质子加权像癌灶检出率由平扫的33-3 % (9/27) 提高到74-1 % (20/27) ,病灶对比度/ 噪声比(CNR) 由0-7±1-9 提高至4-2 ±4-0 ;T2 加权像癌灶检出率由平扫的59-3 % (18/27) 提高到77-8 % (22/27) ,CNR 由2-8 ±2-1 上升至3-9 ±3-3 。结论:HEPSPIO 是一种新型磁共振肝网状内皮系统显影剂,对提高肝脏微小病灶的检出率有重要帮助。     

鼠抗人纤维蛋白单链抗体-低分子量尿激酶融合蛋白在中国仓鼠卵巢细胞中的高效表达

目的：构建鼠抗人纤维蛋白单链抗体－低分子量尿激酶融合基因,并在中国仓鼠卵巢细胞（ＣＨＯ）中高效表达。方法：应用重组ＤＮＡ 技术,将编码尿激酶原信号肽的ＤＮＡ 片段,与鼠抗人纤维蛋白单链抗体－低分子量尿激酶基因融合在一起,并插入真核表达载体ｐＭＪＫ３ 中,构建成重组质粒ｐＭＪＫ３Ｄ。通过细胞电击穿孔法,将该重组质粒转染到中国仓鼠卵巢细胞二氢叶酸还原酶基因缺陷株（ＣＨＯ－ｄｈｆｒ－ ）中,转染细胞经选择培养基筛选,并采用ＭＴＸ加压扩增培养。结果：得到了高效表达融合蛋白的细胞株,表达水平为３００ Ｕ／（１０６ 细胞·ｄ）。通过ＥＬＩＳＡ 和溶解圈方法鉴定,该融合蛋白可与Ｄ－二聚体结合,并具有激活纤溶酶原溶解纤维蛋白的活性。结论：成功构建并获得高效表达双功能融合蛋白的细胞株,为进一步研究这一双功能融合蛋白的体内外特异溶栓活性以及评价其作为新型导向溶栓制剂奠定了基础。     

通脉活血灵胶囊对大鼠实验性高脂血症的影响

目的：观察通脉活血灵胶囊对大鼠高脂血症的影响,并探讨其疗效。方法：采用高脂饲料造成实验性高脂血症大鼠模型。实验组给予药物治疗,测定各组动物血脂、血流变性、血小板聚集功能及过氧化脂质（ＭＤＡ） 含量。结果：通脉活血灵胶囊能降低血脂,改善血流变,抑制血小板聚集,明显降低过氧化脂质。结论：通脉活血灵胶囊对实验性大鼠高脂血症有防治作用。     

门静脉高压侧支循环的螺旋CT表现

探讨肝硬化门脉高压侧支循环的螺旋ＣＴ表现。材料与方法,搜索肝硬化门脉高压患者５２例,其中２３例采用３ｍｍ薄层容积扫描,重建层厚１．５ｍｍ,并进行ＭＩＰ管重建。结果螺旋ＣＴ显示脐周静脉曲张１２例,胆囊周围静脉曲张８例,脾肾静脉侧支开放９例,腹膜后静脉曲线１０例,食管静脉曲张２４例,