White matter damage precedes that in gray matter despite similar magnetic resonance imaging changes following cerebral hypoxia-ischemia in neonatal rats

We hypothesized that the cerebral injury produced by hypoxia-ischemia (HI) in neonatal rats would differ in white compared with gray matter as detected histologically or with magnetic resonance (MR) imaging methods. Maps of T₂ and the apparent diffusion coefficient (ADC) of water were acquired in 1-week-old rats at times prior to cerebral HI (right carotid artery occlusion plus 1.5 h of hypoxia), within the last 5–10 min of HI, and 1 h or 24 h after HI. Near the end of HI, ADC decreased and T₂ increased in both cortical gray and subcortical white matter within the cingulum of the HI hemisphere. One hour after HI, ADC partially recovered, but T₂ remained increased and then increased further by 24 h post-HI. In contrast to the similar MR responses in white and gray matter, histological evidence for irreversible cell damage occurred in white matter earlier than in gray matter within the HI hemisphere. At 1 h post-HI, rarefied or disrupted nerve fibers and an increase in TUNEL-positive cells were observed within white matter in the cingulum, whereas neurons within the cortical gray matter appeared normal. By 24 h post-HI, damage was apparent in both white and gray matter. Thus, MR imaging detected acute tissue edema following cerebral HI in both gray and white matter but did not distinguish between the early irreversible tissue injury detected histologically in white but not gray matter in this rather severe model of neonatal encephalopathy.     

Screening of human anti-TNF-alpha scFv from large phage library

AIM: To clone human anti-TNF-alpha scFv from large phage antibody library. METHODS: Panning of large phage library against TNF-alpha was conducted to select specific antibodies. The antigen binding activity and DNA sequence were determined and analyzed by ELISA, restriction enzyme map. RESULTS: After 4 rounds of panning, 62 positive clones were obtained and 27 clones had specific binding ability to TNF-alpha. DNA fingerprinting of the 27 clones showed 7 different stripes indicated 7 different positive clones. 5 of the 7 clones expressed soluble anti-TNF-alpha activity. DNA sequence analysis showed that the variable regions of these scFvs belonged to different subgroups. CONCLUSION: Human TNF-alpha scFv have been successfully obtained from large phage antibody library.     

基于USB2.0的医用内窥镜超声探头旋转扫描成像系统

介绍基于USB2．0接口的医用超声内窥镜旋转扫描成像的设计与实现。根据超声成像的特点，本系统采取脉冲回波成像方式，文中介绍了超声波激发、接收电路以及收发隔离电路。针对旋转扫描的特点，设计了基于FPGA的同步控制电路和基于USB2．0接口的数据传输电路。对采集到的原始图像，进行坐标变换，获得了按直角坐标显示的灰度图像。利用连续旋转马达对实际物体扫描成像的实验结果，验证了系统的正确性。     

纤维蛋白原Bβ链基因-1420G/A、-993C/T和-854G/A多态性与冠状动脉粥样硬化性心脏病的关联研究

目的调查健康人和冠状动脉粥样硬化性心脏病(简称冠心病)患者的纤维蛋白原B(fibrino-genB,FGB)β基因-1420G/A、-993C/T和-854G/A的基因多态性频率分布,以及与血浆Fg水平的关系。方法应用等位基因特异性PCR扩增技术和限制性片段长度多态性技术对186例冠心病患者和149名健康对照者进行分析。比浊法测定血浆Fg浓度。结果等位基因频率-1420A在冠心病组为0.33,在对照组为0.26,冠心病组明显比对照组升高,两者比较差异有统计学意义(P<0.05)。等位基因频率-993T和-854A在两组之间无差别。Logistic回归分析显示β-1420G/A与冠心病相关(OR=1.922,P=0.003)。冠心病组血浆Fg水平(3.87±1.75)g/L较健康人组(3.10±0.77)g/L明显升高,且差异有统计学意义(P<0·05)。结论纤维蛋白原Bβ-1420G/A可能与冠心病发病相关联。     

The critical role of ocular-infiltrating macrophages in the development of choroidal neovascularization

Choroidal neovascularization (CNV) is directly related to visual loss in some eye diseases, such as age-related macular degeneration. Although several human histological studies have suggested the participation of macrophages in CNV formation, the precise mechanisms are still not fully understood. In this study, we elucidated the role of ocular-infiltrating macrophages in experimental CNV using CCR2 knockout (KO) mice, wild-type mice, and C57BL/6 (B6) mice. CCR2 is the receptor of monocyte chemoattractant protein-1, and the number of infiltrating macrophage and the area of CNV were significantly reduced in CCR2 KO mice. Enriched ocular-infiltrating macrophages from B6 mice actually showed angiogenic ability in a dorsal air sac assay. Moreover, their expression of class II, CD40, B7-1 and B7-2 molecules, and the mRNA for potential angiogenic factors, such as vascular endothelial growth factor, basic fibroblast growth factor, and tumor necrosis factor alpha, was also observed. Collectively, we conclude that ocular-infiltrating macrophages play an important role in CNV generation.     

老年人脑白质疏松症血液流变性及血液成分的改变

对３８例老年脑白质疏松症（ＬＡ）患者进行了部分血液流变性和血液成分指标的测定。结果：与健康者比较，ＬＡ患者全血粘度、血浆粘度、ＲＢＣ刚性指数和聚集指数、纤维蛋白原显著增高，ＲＢＣ变形能力明显降低，血Ｈｂ、ＭＣＶ、ＭＣＨ、ＭＣＨＣ、ＲＤＷ－ＣＶ显著增高。提示：血液流变性异常和红细胞老化参与了ＬＡ的发生。设法纠正患者高粘和高凝状态、提高红细胞变形能力有益于阻止该病的进展     

学龄期儿童记忆发展特点研究

目的:研究学龄期儿童记忆发展特点.方法:以285名7-15岁儿童为研究对象,以龚氏记忆成套测验(儿童本)为测评工具,以7岁组平均成绩为基线值,观察各分测验及各项记忆指数随年龄发展的特点.结果:理解记忆、联想记忆、听觉广度等分测验成绩在整个学龄期持续上升,于13岁左右达到峰值;图片记忆、空间广度等分测验成绩在7-11岁之间上升较快,11岁以后不再有明显上升;再认测验成绩在整个学龄期有上升,但上升趋势平缓,幅度小.结论:学龄期儿童各种记忆能力均有明显提高,但不同记忆成分的发展特点不同.听觉记忆上升时间长,达到成熟的时间晚,视觉记忆达到成熟的时间较早,再认记忆成绩上升幅度最小.     

单侧外周伤害性刺激诱发大鼠脊髓中转录因子CREB的双侧磷酸化(英文)

c AMP反应成分结合蛋白 (c AMP response elem ent-binding protein,CREB)是一种转录因子 ,它在磷酸化之后可调节靶基因的转录。 CREB在 13 3位置的丝氨酸的磷酸化 ,与脊髓中伤害性传入的处理有关 ,本文作者等用特殊抗体对此进行了免疫细胞化学研究。在正常大鼠 ,虽然几乎所有脊髓神经元的核中都可见 CREB的轻度着色 ,但磷酸化的 CREB仅见于双侧腰段脊髓的 ～ 层 (75± 15 vs60± 18)和 层 (9± 3 )。用福尔马林注射引起一侧后脚掌出现炎症时 ,可在双侧腰段脊髓看到磷酸化CREB细胞核的快速 (小于 5 min)和节段性的显著增多 ;它们主要分布在双侧背角表层 ～ 层 (2 5 4± 2 0 vs 2 62± 2 3 )、 层(115± 13 )和双侧 ～ 层 (3 46± 2 0 vs3 2 8± 2 6) ;而在对照和炎症组大鼠的胸段脊髓中均未见磷酸化 CREB的增加。在注射CFA诱发一侧炎症或切断一侧坐骨神经的实验组大鼠 ,也可看到至少延续到第三天的强而双侧性的 CREB的磷酸化。这种由一侧后肢伤害性传入引致腰段脊髓中镜像式双侧 CREB磷酸化的出现 ,与一般看到的损伤传入只在同侧脊髓背角引起某些神经化学改变的结果不同 ,可能是人神经损伤后或在实验动物中出现对侧镜像式疼痛过敏现象的基础     

6024例分娩的方式选择与新生儿结局

目的探讨阴道分娩和剖宫产对新生儿的风险。方法对6024例妊娠的分娩方式、剖宫产指征以及新生儿结局回顾性分析。结果剖宫产率为35.3%,其指征主要是头盆不称、社会因素、宫内窘迫、臀位等。分娩新生儿6016例,其中因各种疾患转儿科822例,占13.5%。主要转科原因为早产儿低体重、窒息、高胆红素血症和吸入综合症,各疾病发病率与分娩方式无关。结论剖宫产没有增加新生儿的风险,仍是解决难产的重要手段,但应严格控制手术指征。     

超声手术刀组织切割的实验研究

用国产超声手术刀，在大白兔活体上进行切割实验．并与普通手术刀和高频电刀进行了比较．结果显示超声手术刀的组织切割速度和切缘整齐情况不及普通手术刀，但有一定的止血功能，组织损伤不如高额电刀大，也不引起肌肉收缩，无组织烧焦气味；术后切缘愈合良好．认为超声手术刀更适合于肝、脾等实质性组织的切割．如在操作柄、刀具、仪器性能等方面能进一步改进，应用效果会更好。