Altered GABAB receptor immunoreactivity in the gerbil hippocampus induced by baclofen and phaclofen, not seizure activity

The present study was performed to determine whether the effects induced by GABA(B) receptor-acting drugs would be related with the alteration in GABA(B) receptor expression in the hippocampus using Mongolian gerbil, a genetic epilepsy model. The distribution patterns of both GABA(B) receptor 1A/B and GABA(B)receptor 2 immunoreactivities were similarly detected in the hippocampi of normal and seizure-prone gerbils. Following baclofen (GABA(B) receptor agonist) or phaclofen (GABA(B) receptor antagonist) treatment, GABA(B) receptor immunoreactivities were decreased or increased by dose-dependent manners, respectively. Vigabatrin (GABA transaminase inhibitor) or 3-mercaptopropionic acid (GAD inhibitor) treatment did not affect GABA(B) receptor expressions. These findings suggest that GABA(B) receptor expression in the gerbil hippocampus may be altered by baclofen or phaclofen treatment.     

Ly49E expression points toward overlapping,but distinct,natural killer (NK) cell differentiation kinetics and potential of fetal versus adult lymphoid progenitors

Using a new antibody, we found previously that contrary to adult natural killer (NK) cells, fetal NK cells have a unique phenotype, as they exclusively express Ly49E. This can be explained by an intrinsic different NK differentiation potential of fetal versus adult lymphoid progenitors, by immaturity of fetal NK cells or by instability of Ly49E expression. Here, we show that adult progenitor cells were still capable of differentiating into Ly49E-expressing NK cells but at a much lower frequency. Surprisingly, Ly49E expression in vitro did not require stromal cells. Kinetic analysis in vivo showed that Ly49E was expressed early, together with CD94/NKG2 and Ly49G2, followed by Ly49C, and finally Ly49D. Transfer of sorted Ly49E-positive fetal NK cells showed stable Ly49E expression, and later, part of these cells up-regulated other Ly49 members. These data indicate that although there are intrinsic differences, there is no strict fetal and adult wave of NK cell differentiation.     

胰腺癌微淋巴管的分布及其临床意义

目的探讨胰腺癌组织周边和内部VEGF-C、VEGF-D蛋白表达与微淋巴管密度(microlymphtic vesseles density,MLVD)及淋巴结转移之间的相关关系,阐明癌周淋巴管增生的机制及意义。方法免疫组化检测30例胰腺癌组织周边和内部VEGF-C、VEGF-D、VEGFR-3(MLVD)蛋白的表达。结果肿瘤周边部位VEGF-C、VEGF-D蛋白阳性率分别为73.3%(22/30)、56.7%(17/30),显著高于肿瘤中心部位;在VEGF-C蛋白阳性组,MLVD显著高于阴性组(P<0.01),淋巴结转移发生率增高(P=0.0318);VEGF-D蛋白阳性组MLVD高于阴性组(P<0.01),淋巴结转移发生率增加(P=0.0179)。结论胰腺癌癌周VEGF-C、VEGF-D蛋白表达、MLVD显著高于肿瘤中心部位;癌周VEGF-C、VEGF-D蛋白表达、MLVD与淋巴结转移发生率呈正相关;提示VEGF-C和VEGF-D诱导胰腺癌癌周淋巴管生成,促进肿瘤细胞淋巴道转移。     

The effects of tibial rotation on patellar position

The effects of external and internal tibial rotation on patellar motion were investigated using a magnetic 3Space^® tracker system (Polhemus, Colchester, VT 05446, USA). Seven fresh-frozen adult cadaver knees were used in this study. The muscle alignment of each quadriceps muscle was measured to determine the direction of loading forces. Three loading patterns were used to simulate the unresisted knee extension during sitting, standing from squatting and the stance phase of walking, with different weights applied to each quadriceps muscle at each knee flexion angle. The position of the patella, along with patellar shift, tilt and rotation was measured and compared to external or internal tibial rotation and neutral rotation. In the sitting and squatting simulations the patella showed at the terminal extension of the knee more lateral shift and a more lateral tilt with tibial external rotation than in a neutral position (P < 0.05). In walking simulation, the patella showed more external rotation with external rotation of the tibia than with a neutral one, at the 0, 72 and 90% of the stance phase of walking (P < 0.05). These results demonstrate the importance of external tibial rotation as a factor in the development of patellar dislocations or subluxations, especially in athletes.     

Dynamic pressure transmission through agarose gels

In biomedical research, agarose gel is widely used in tissue culture systems because it permits growing cells and tissues in a three-dimensional suspension. This is especially important in the application of tissue engineering concepts to cartilage repair because it supports the cartilage phenotype. Mechanical loading, especially compression, plays a fundamental role in the development and repair of cartilage. It would be advantageous to develop a system where cells and tissues could be subjected to compression so that their responses can be studied. There is currently no information on the pressure response of agarose gel when pressure is applied to the gas phase of a culture system. To understand the transmission of pressure through the gel, we set up an apparatus that would mimic an agarose suspension tissue culture system. This consisted of a sealed metal cylinder containing air as well as a layer of agarose submerged in culture medium. Pressure responses were recorded in the air, fluid, gel center, and gel periphery using various frequencies, pressures, gel volumes, and viscosities. Regression analyses show an almost perfect linear relation between gas and gel pressures (r(2) = 0.99987, p < 0.0001, f(x) = 0.9982 x - 0.0286). The pressure transmission was complete and immediate, throughout the range of the applied pressures, frequencies, volumes, and viscosities tested. Applying dynamic pressure to the gas phase results in reproducible pressure in the agarose and, therefore, validates the use of agarose tissue culture systems in studies employing dynamic pressurization in cartilage tissue engineering.     

胶质瘤bcd—2基因表达水平与其细胞增殖和凋亡关系的研究

目的 探讨胶质瘤细胞ｂｃｌ－２基因表达水平与肿瘤恶性程度、细胞增殖活性及凋亡程度的关系。方法 以６９例不同级别的人胶质瘤组织为研究对象,用原位杂交及免疫组化染色ＡＢＣ法分别检测ｂｃｌ－２ｍＲＮＡ、ｂｃｌ－２蛋白和增殖细胞核抗原（细胞增殖活性标记物）的表达,并用３’末标记法做原位细胞凋亡检测。结果 ６４例（９２．８％）表达ｂｃｌ－２ｍＲＮＡ,６０例（８７．０％）表达ｂｃｌ－２蛋白,两者的表达水平呈正     

重组人bFGF的原核表达及其高效价抗血清的制备

目的 以重组人碱性成纤维生长因子为免疫原，制备高效价抗hbFGF抗血清。方法通过PCR方法改造5’编码区的12个密码子，构建hbFGF’原核表达载体并在大肠杆菌(E．coli)中表达，以纯化的hbFGF、免疫新西兰兔，制备高效价抗血清，用于重组hbFGF、的免疫印迹分析。结果经过改造的hbFGF基因在E．coli中获得较高水平表达。从可溶性部分纯化得到纯度95％以上的重组hbFGF，以该重组蛋白免疫兔子，在二次加强后以间接ELISA检测抗血清效价可达1：512000。免疫印迹分析显示该抗血清与E．coli中表达的重组hbFGF、和标准hbFGF、均有特异性反应，但与某些细菌蛋白存在弱交叉反应，经E．coli菌体蛋白吸附的抗血清，与菌体蛋白的弱交叉反应消失。结论以纯化的重组hbFGF为免疫原制备了高效价的特异性抗血清，经菌体蛋白吸附可消除存在的交叉反应性。     

KChIP1 and frequenin modify shal-evoked potassium currents in pyloric neurons in the lobster stomatogastric ganglion

The transient potassium current (I(A)) plays an important role in shaping the firing properties of pyloric neurons in the stomatogastric ganglion (STG) of the spiny lobster, Panulirus interruptus. The shal gene encodes I(A) in pyloric neurons. However, when we over-expressed the lobster Shal protein by shal RNA injection into the pyloric dilator (PD) neuron, the increased I(A) had somewhat different properties from the endogenous I(A). The recently cloned K-channel interacting proteins (KChIPs) can modify vertebrate Kv4 channels in cloned cell lines. When we co-expressed hKChIP1 with lobster shal in Xenopus oocytes or lobster PD neurons, they produced A-currents resembling the endogenous I(A) in PD neurons; compared with currents evoked by shal alone, their voltage for half inactivation was depolarized, their kinetics of inactivation were slowed, and their recovery from inactivation was accelerated. We also co-expressed shal in PD neurons with lobster frequenin, which encodes a protein belonging to the same EF-hand family of Ca(2+) sensing proteins as hKChIP. Frequenin also restored most of properties of the shal-evoked currents to those of the endogenous A-currents, but the time course of recovery from inactivation was not corrected. These results suggest that lobster shal proteins normally interact with proteins in the KChIP/frequenin family to produce the transient potassium current in pyloric neurons.