Complete remission of TEL-PDGFRB-induced myeloproliferative disease in mice by receptor tyrosine kinase inhibitor SU11657

The TEL-PDGFRB fusion oncogene is associated with chronic myelomonocytic leukemia (CMML) and results in the expression of a constitutively active tyrosine kinase. SU11657 is a multitargeted selective inhibitor of class III/V receptor tyrosine kinases, including the platelet-derived growth factor (PDGF) and vascular endothelial growth factor (VEGF) receptors KIT and FLT3. SU11657 inhibited TEL/PDGFbetaR kinase activity at nanomolar concentrations and inhibited TELPDGFRB-mediated factor-independent growth in myeloblastic 32D cells. Daily oral administration of SU11657 at 40 mg/kg suppressed myeloproliferation and significantly prolonged survival in TELPDGFRB mice treated prior to disease development, as well as in those with large tumor burdens. Our findings suggest that SU11657 or similar agents may have therapeutic potential in humans with hematologic malignancies expressing PDGFR fusion oncogenes.     

A systematic review of the psychometric properties of transition readiness assessment tools in adolescents with chronic disease

Background

Health care transition of adolescents with chronic conditions may be unsuccessful when patients have not acquired the necessary skills and developmental milestones. It is therefore critical for health care providers to assess the readiness for transition of their adolescent patients. This is currently hindered by the lack of a recognised, well-established transition-readiness assessment tool.

Methods

We conducted a systematic review of all transition-readiness tools for adolescents with chronic medical conditions published in peer-reviewed journals. Tools were rated by the methodological quality of the validation studies, and the psychometric measurement qualities of each tool.

Results

Ten different assessment tools were identified. Seven targeted specific diseases and 3 tools were generic. Most tools were poorly validated with only one tool, the Transition Readiness Assessment Questionnaire (TRAQ) demonstrating adequate content validity, construct validity, and internal consistency.

Conclusion

The TRAQ was the best-validated transition-readiness tool, with additional benefits of disease-neutrality. Further research should focus on testing the predictive validity of this tool, and exploring correlation with transition-outcomes, in an international population.     

Mutations in the C-terminal domain of Sonic Hedgehog cause holoprosencephaly

Holoprosencephaly (HPE) is the most common brain anomaly in humans, involving abnormal formation and septation of the developing central nervous system. Among the heterogeneous causes of HPE, mutations in the Sonic Hedgehog (SHH) gene have been shown to result in an autosomal dominant form of the disorder. Here we describe a total of five different mutations in the processing domain encoded by exon 3 of SHH in familial and sporadic HPE. This is the first instance in humans where SHH mutations in the domain responsible for autocatalytic cleavage and cholesterol modification of the N-terminal signaling domain of the protein have been observed.      

Dopamine increases renal oxygenation: a clinical study in post‐cardiac surgery patients

Background: Imbalance of the renal medullary oxygen supply/demand relationship can cause ischaemic acute renal failure (ARF). The use of dopamine for prevention/treatment of ischaemic ARF has been questioned. It has been suggested that dopamine may increase renal oxygen consumption (RVO₂) due to increased solute delivery to tubular cells, which may jeopardise renal oxygenation. Information on the effects of dopamine on renal perfusion, filtration and oxygenation in man is, however, lacking. We evaluated the effects of dopamine on renal blood flow (RBF), glomerular filtration rate (GFR), RVO₂ and renal O₂ demand/supply relationship, i.e. renal oxygen extraction (RO₂Ex). Methods: Twelve uncomplicated, mechanically ventilated and sedated post‐cardiac surgery patients with pre‐operatively normal renal function were studied. Dopamine was sequentially infused at 2 and 4 ug/kg/min. Systemic haemodynamics were evaluated by a pulmonary artery catheter. Absolute RBF was measured using two independent techniques: by the renal vein thermodilution technique and by infusion clearance of paraaminohippuric acid (PAH), with a correction for renal extraction of PAH. The filtration fraction (FF) was measured by the renal extraction of ⁵¹Cr‐EDTA. Results: Neither GFR, tubular sodium reabsorption nor RVO₂ was affected by dopamine, which increased RBF (45–55%) with both methods, decreased renal vascular resistance (30–35%), FF (21–26%) and RO₂Ex (28–34%). The RBF/CI ratio increased with dopamine. Dopamine decreased renal PAH extraction, suggestive of a flow distribution to the medulla. Conclusions: In post‐cardiac surgery patients, dopamine increases the renal oxygenation by a pronounced renal pre‐and post‐glomerular vasodilation with no increases in GFR, tubular sodium reabsorption or renal oxygen consumption.     

功能磁共振成像与弥散张量成像联合监测视觉通路异常在高压氧治疗前后的结构及功能变化

目的:联合应用血氧依赖功能磁共振成像(BOLD-fMRI)和弥散张量成像技术评价视觉通路异常高压氧患者在康复过程中脑功能和解剖结构的重组特点。方法:①临床资料:选择2006-01/2007-05解放军南京军区福州总医院收治的因视觉通路病变致单侧或双侧视觉障碍的16例患者为病变组,均接受2个标准大气压高压氧治疗3个疗程。以性别、年龄与病变组大致匹配的正常视力者12例作为正常对照组。②磁共振扫描及分析:两组以相同条件,采用黑白棋盘格变化刺激双眼,应用Signa xcite HD 1.5T双梯度16通道磁共振成像系统进行测试。BOLD-fMRI数据处理采用AFNI软件包进行,弥散张量成像应用日本东京大学影像计算和分析实验室开发的Volume-one 1.64下的dTV.II.R1软件进行数据处理。③观察指标:病变组高压氧干预前后BOLD-fMRI激活体数和弥散张量成像表现,并与正常对照组比较。结果:28例受试者均进入结果分析。①BOLD-fMRI激活体数值:病变组高压氧治疗前视皮质激活体数低于正常对照组(P<0.01),高压氧治疗后视皮质激活体数与正常对照组比较差异不显著(P>0.05),但高于高压氧治疗前(P<0.05)。②弥散张量成像示视放射部分各向异性值:病变组高压氧治疗前部分各向异性值低于正常对照组(P<0.05),高压氧治疗后与正常对照组比较差异不显著(P>0.05),且显著高于高压氧治疗前(P<0.05)。病变组中的6例视神经病变患者视放射显示完整,康复前后的视放射部分各向异性值与正常对照组比较无显著性差异(P>0.05),10例枕叶视中枢病变患者视放射纤维部分中断,视放射各向异性值低于视神经病变患者(P<0.05)。结论:BOLD-fMRI联合弥散张量成像能从功能和结构方面探讨视觉通路病变的发生、发展及康复过程,为脑功能的康复提供较为可靠的治疗依据。     

犬骨髓单个核细胞诱导分化为平滑肌样细胞

目的:探讨体外诱导骨髓单个核细胞分化为平滑肌样细胞的可行性,为构建组织工程器官提供种子细胞。方法:实验于2005-10/2006-12在教育部重点实验室,实验室等级1级的首都医科大学宣武医院外科实验室完成。实验材料:体质量20～30kg成年雌性杂种犬6只,由北京市科宇实验动物养殖中心提供(许可证号为SCXK(京)2000-0015),动物饲养级别1级。实验方法:①骨髓单个核细胞的分离培养:穿刺健康成年实验犬髂前上棘,抽取骨髓10mL,加入肝素抗凝,以等体积PBS充分混匀,4℃条件下转入离心管中,取20mL淋巴细胞分离液,将稀释骨髓按1∶1小心加在分离液的界面上,用水平离心机以1500r/min离心10min后,单个核细胞位于血浆和离心液界面层。吸取界面层单个核细胞层,以含体积分数为0.1胎牛血清的PBS冲洗3次,备用。②骨髓单个核细胞诱导分化为平滑肌样细胞:将收获的犬骨髓单个核细胞以由含体积分数为0.15胎牛血清的DMEM/F12混合培养液、0.5μg/L内皮细胞生长因子、2μg/L碱性成纤维生长因子、10μg/L血小板源性生长因子BB、100μg/L胰岛素样生长因子、1mmol/L磷酸维生素C、0.04mmol/L脯氨酸组成的诱导培养基重悬,以1×109L-1种植于胶原铺底的培养瓶中,置37℃、含50mL/LCO2饱和湿度培养箱中,进行诱导培养。倒置相差显微镜下观察细胞形态特征。在诱导培养后第1,3,5,7,9,11天绘制细胞生长曲线。采用免疫组织化学方法进行细胞表型鉴定,并评价细胞生长增殖情况。结果:①骨髓单个核细胞向平滑肌样细胞诱导的细胞生长曲线:接种第1,3,5,7,9,11天计数每孔细胞数分别为(2.73±0.18)×108,(3.17±0.36)×108,(7.35±1.28)×108,(23.61±1.56)×108,(53.48±3.47)×108,(48.51±5.36)×108L-1。②免疫组织化学方法鉴定细胞表型:原代细胞仅少数α-平滑肌肌动蛋白染色明显阳性,明显阳性细胞约占总数的(60.5±5.9)%,细胞内肌丝样结构不明显,而平滑肌肌球蛋白重链、碱性钙调宁蛋白染色阴性;P3代细胞生长5d,细胞生长汇合后,绝大部分诱导后细胞α-平滑肌肌动蛋白、平滑肌肌球蛋白重链、碱性钙调宁蛋白染色阳性,可见胞浆内清晰的肌丝样结构,明显阳性细胞分别占细胞总数的(86.2±13.5)%,(78.7±10.2)%,(76.63±13.8)%,明显高于原代细胞(P<0.05)。③平滑肌样细胞的亚型分析:原代细胞爬片标本Flk-1染色多数呈阳性,第3代细胞Flk-1染色几乎阴性,阳性细胞胞膜、胞浆着色呈棕黄色。原代及传代细胞Vimentin染色均呈阳性,阳性细胞胞浆着棕黄色。本组细胞Desmin染色阴性。结论:骨髓单个核细胞可以被定向诱导成为平滑肌样细胞,能够满足组织工程种子细胞的要求。     

骨髓干细胞移植后Western blot免疫印迹分析鼠抗肌萎缩蛋白表达的变化

目的:Western blot免疫印迹分析骨髓干细胞移植后mdx鼠抗肌萎缩蛋白表达的变化。方法:实验于2004-09/12在中山大学附属第一医院神经科实验室完成。①选取7～8周龄mdx鼠25只,随机数字表法分为骨髓移植4,8,12,16周组、空白对照组,5只/组。另选取4～6周龄C57鼠20只作为供体鼠,10周龄C57鼠5只作为阳性对照组。②各组在移植前均给予照射剂量为7Gy的放疗预处理。放疗完毕后,骨髓移植4,8,12,16周组均进行尾静脉细胞移植,移植细胞数为2×107/只,0.3～0.5mL;空白对照组、阳性对照组尾静脉输入0.3mL磷酸盐缓冲液。③骨髓移植4,8,12,16周组分别于对应时间点处死,取其腓肠肌,制备抗肌萎缩蛋白样品,进行抗肌萎缩蛋白Western blot免疫印迹分析,以GAPDH作为内参。结果:25只7～8周龄mdx鼠、5只10周龄C57鼠全部进入结果分析。骨髓干细胞移植后抗肌萎缩蛋白Western Blot免疫印迹分析结果:空白对照组无抗肌萎缩蛋白的表达;骨髓移植4周组仅可见抗肌萎缩蛋白的微弱表达,dystrophin/GAPDH灰度比值约为0.095±0.267;骨髓移植12周组约为0.218±0.338;随骨髓移植时间的延长抗肌萎缩蛋白表达量逐渐增加,移植后16周的表达量较移植后8周明显增加(0.393±0.385,0.173±0.284;t=6.062,P<0.05),但仍明显低于阳性对照组1.172±0.328(t=3.14,P<0.05)。结论:骨髓干细胞移植mdx鼠后应用WesternBlot免疫印迹分析可于不同时间检测到抗肌萎缩蛋白的表达,且随移植时间延长表达量增多,提示骨髓干细胞移植可长久持续参与受损骨骼肌的修复与再生。