原癌基因BMI-1的研究进展

BMI-1(B-cell specific moloneyleukemia virusinsertion site 1,BMI-1)是PcG(Polycomb group,PcG)家族的一员,同时也是一种原癌基因,与c-myc一起参与小鼠T、B细胞淋巴瘤的发生。选择性敲除BMI-1可导致出生后进行性发育迟缓、神经系统异常和严重的造血缺陷等。本文就原癌基因BMI-1的研究进展作一综述。1 PcG家族的概述PcG基因家族最初是在果蝇体内作为HOX的抑制因子被鉴定出,迄今为止已发现30~40种PcG基因,它们协同作用以维持机体内细胞的转录抑制状态。PcG家族调节许多生命过程中的基因表达,包括造血、前后轴形成以及调控靶基…     

Current state of vitiligo therapy – evidence-based analysis of the literature

Vitiligo is a skin disease with a worldwide prevalence ranging from 0.5% to 4%. Conservative therapies include photochemotherapy, phototherapy with UVB radiation (broadband UVB 290–320 nm, narrow band UVB 311 nm), systemic steroids and pseudocatalase. Modern therapeutic options include treatment with topical immunomodulators (tacrolimus, pimecrolimus), analogues of vitamin D3, excimer laser and surgery/transplantation. Our analysis compares these therapies for vitiligo and the evidence levels supporting their effectiveness. Conclusions: The face and neck respond best to all therapeutic approaches, while the acral areas are least responsive. For generalized vitiligo, phototherapy with UVB radiation is most effective with the fewest side effects; PUVA is the second best choice.Topical corticosteroids are the preferred drugs for localized vitiligo. They may be replaced by topical immunomodulators which display comparable effectiveness and fewer side effects.The effectiveness of vitamin D analogues is controversial with limited data. Surgical therapy can be very successful, but requires an experienced surgeon and is very demanding of time and facilities, thus limiting its widespread use. L-phenylalanine therapy appears effective on the face but enjoys neither widespread use nor extensive data support. No single therapy for vitiligo can be regarded as the most effective as the success of each treatment modality depends on the type and location of vitiligo.     

锁骨上神经营养血管皮瓣的应用解剖

目的为临床应用锁骨上神经营养血管皮瓣提供解剖学依据。方法在36侧经股动脉插管灌注红色乳胶溶液的成人尸体标本上,对锁骨上神经营养血管的横径、长度及穿深筋膜点的位置,进行了观测,并在标本上模拟手术设计。结果锁骨上神经营养血管包括颈升动脉肌皮支、颈横动脉颈段皮支、胸廓内动脉穿支、胸肩峰动脉胸肌支与肩峰支皮动脉,其穿深筋膜点外径分别为0.75、1.12、1.36、0.70、0.79mm;且穿深筋膜点位置相对恒定,节段性地分布于锁骨上神经,为整段皮神经提供营养。结论以上述节段动脉为蒂,设计锁骨上神经营养血管皮瓣。     

金属蛋白酶2、血管内皮生长因子和肿瘤抑制因子在人脑胶质瘤中的表达和临床意义

目的:探讨人脑胶质瘤中的金属蛋白酶2(MMP-2)、血管内皮生长因子(VEGF)和肿瘤抑制因子(P16)的表达。方法:应用免疫组化法检测55例胶质瘤组织中的MMP-2、VEGF和P16蛋白的表达,通过原位杂交检测MMP-2 mRNA的表达。结果:胶质瘤的恶性程度与MMP-2、VEGF表达和P16的缺失表达呈正相关,随着胶质瘤的恶性程度的增高而增加。结论:胶质瘤的恶性程度由多种因素决定。胶质瘤中MMP-2含量越高,肿瘤细胞在浸润的过程中突破血脑屏障的能力越强;VEGF的表达增加,肿瘤的血液供应越丰富,恶性程度越高。P16蛋白缺失率高,组织学分化程度低,在一定程度上反映了胶质瘤细胞的恶性生物学行为。     

海人酸致大鼠海马结构GABA_B受体亚单位表达的研究

目的:探讨海人酸诱导大鼠颞叶癫(EP)发作后2种γ-氨基丁酸(GABA)受体亚单位GABABR亚单位1a(GBR1a)和GABABR亚单位2(GBR2)在EP发生、发展中的作用。方法:运用原位杂交及免疫组化法,检测EP发作后GABABR亚单位mRNA及蛋白在海马的表达。结果:致早期CA1和CA3区2种亚单位mRNA表达持续低下后逐渐增加,DG区则暂时性下降后很快回升;而免疫反应早期却未见明显改变,随后CA1和CA3区表达处于低水平,DG区和颞叶皮质表达下降后很快恢复。结论:致后2种GABAB受体亚单位基因和蛋白表达上调为颞叶EP的内源性自我保护机制。     

Compensation for spin-lock artifacts using an off-resonance rotary echo in T1rhooff-weighted imaging.

The origin of image artifacts in an off-resonance spin-locking experiment is shown to be imperfections in the excitation flip angle. A pulse sequence for off-resonance spin locking is implemented that compensates for imperfections in the excitation flip angle through an off-resonance rotary echo. The off-resonance rotary echo alternates the frequency offset and phase of the RF transmitter during two spin-locking pulses of equal duration. The underlying theory is detailed, and MR images demonstrate the effectiveness of the technique in agarose gel phantoms and in in vivo human brain at 3T.     

糖尿病大鼠骨折后骨形态发生蛋白-2、胰岛素样生长因子-1的变化

目的 观察糖尿病大鼠骨折后骨形态发生蛋白-2(BMP-2)、胰岛素样生长因子-1(IGF-1)的变化,探讨糖尿病对骨折愈合的影响.方法 70只大鼠随机分为对照组和糖尿病组,均造成左侧胫骨骨折.定期摄X线片,取骨痂HE染色,免疫组化检测骨痂BMP-2、IGF-1,ELISA法检测血清BMP-2、IGF-1.结果 2周BMP-2灰度值:实验组为149±8,对照组为107±7(P＜0.01);2周IGF-1灰度值:实验组为137±9,对照组为103±8(P＜0.01).2周血清BMP-2含量:实验组为(3.45±0.12) ng/ml,对照组为(5.60±0.11) ng/ml(P＜0.01);2周IGF-1含量:实验组为(5.89±0.12) ng/ml,对照组为(8.36±0.11) ng/ml(P＜0.01).结论 糖尿病大鼠骨折后血清及骨痂中BMP-2、IGF-1减少是导致糖尿病大鼠骨折愈合差的原因之一;BMP-2与IGF-1可能存在相互作用.     

Impact of Increasing Margin Around the Lumpectomy Cavity to Define the Planning Target Volume for 3D Conformal External Beam Accelerated Partial Breast Irradiation

The purpose of this study was to evaluate the dose to normal tissues as a function of increasing margins around the lumpectomy cavity in accelerated partial breast irradiation (APBI) using 3D-conformal radiotherapy (3DCRT). Eight patients with Stage 0-I breast cancer underwent treatment planning for 3DCRT APBI. The clinical target volume (CTV) was defined as a 15-mm expansion around the cavity limited by the chest wall and skin. Three planning target volumes (PTV1, PTV2, PTV3) were generated for each patient using a 0, 5-, and 10-mm expansion around the CTV, for a total margin of 15, 20, and 25 mm. Three treatment plans were generated for every patient using the 3 PTVs, and dose-volume analysis was performed for each plan. For each 5-mm increase in margin, the mean PTV:total breast volume ratio increased 10% and the relative increase in the mean ipsilateral breast dose was 15%. The mean volume of ipsilateral breast tissue receiving 75%, 50%, and 25% of the prescribed dose increased 6% to 7% for every 5 mm increase in PTV margin. Compared to lesions located in the upper outer quadrant, plans for medially located tumors revealed higher mean ipsilateral breast doses and 20% to 22% more ipsilateral breast tissue encompassed by the 25% IDL. The use of 3DCRT for APBI delivers higher doses to normal breast tissue as the PTV increases around the lumpectomy cavity. Efforts should be made to minimize the overall PTV when this technique is used. Ongoing studies will be necessary to determine the clinical relevance of these findings.     

Co-segregation of the PROS1 locus and protein S deficiency in families having no detectable mutations in PROS1.

Inherited deficiency of protein S constitutes an important risk factor of venous thrombosis. Many reports have demonstrated that causative mutations in the protein S gene are found only in approximately 50% of the cases with protein S deficiency. It is uncertain whether the protein S gene is causative in all cases of protein S deficiency or if other genes are involved in cases where no mutation is identified. The aim of the current study was to determine whether haplotypes of the protein S gene cosegregate with the disease phenotype in cases where no mutations have been found. Eight protein S-deficient families comprising 115 individuals where previous DNA sequencing had failed to detect any causative mutations were analyzed using four microsatellite markers in the protein S gene region. Co-segregation between microsatellite haplotypes and protein S deficiency was found in seven of the investigated families, one family being uninformative. This suggests that the causative genetic defects are located in or close to the protein S gene in a majority of such cases where no mutations have been found.     

磁共振成像对脑静脉畸形的诊断价值

目的 探讨磁共振成像各种方法对脑静脉畸形的诊断价值。方法 收集本院6例脑静脉畸形病例，均进行过磁共振T1WI、T2WI扫描，其中部分病例做过DWI、T2FLAIR、MRA、MRV、T1WI增强扫描及DSA。结果 幕上4例，幕下2例，T1WI、T2WI表现：引流静脉均为流空的低信号，深髓静脉为细条状长T1、长T2信号。其中1例DWI引流静脉及深髓静脉区域低信号；1例T2 FLAIR引流静脉流空的低信号，深髓静脉高信号；2例MRA均阴性，但MRV显示深髓静脉汇入引流静脉；2例T1 WI增强扫描：深髓静脉呈轮辐状汇入引流静脉；1例DSA：动脉期阴性，静脉期见典型的“海蛇头”征。结论 磁共振能明确诊断脑静脉畸形，T1WI增强扫描及MRV均较敏感，DSA为诊断脑静脉畸形金标准。