正常兔眼后房压强及前后房压强差值的在体监测

目的 寻求一种眼后房穿刺方法,并在体测量兔眼的前、后房压强差.方法 利用高精度压力传感器与空气差压传感器,采用＂从角巩膜缘外周1～1.5mm处进针穿透巩膜,使针水平滑行于虹膜下而进入后房＂的扎针方法,实现在体连续监测正常兔眼麻醉状态下的后房压强与前后房压强差值.结果 麻醉状态下兔眼后房压强的范围在839.93～2662.48Pa;前、后房压强差范围是46.15～85.52Pa,均值为59.73Pa,变化周期为11.17min.结论 扎针方法测量兔眼后房压强及前后房压强差值对眼球损伤较小,监测到的正常兔眼后房压强及前后房压强差值均在合理可信的范围内.监测方法的可行性为青光眼前后房压强差值的在体监测提供了新的思路.     

在体兔眼压强-体积关系的实验研究

目的 获得在体兔眼眼内压与眼球体积变化的关系。方法 通过对在体兔眼前房以20 μL/min的速度注入生理盐水100 min,记录眼内压随注水时间的变化数据。结果 眼内压随注水时间的曲线呈非线性变化,可用分段函数拟合。曲线的上升段存在一特殊点（定义为拐点）,此点前后的眼球刚度系数分别为（4.02±0.86) mmH2O/μL和(2.43±0.94) mmH2O/μL (1 mmH2O=9.8 Pa),有显著性差异。结论 拐点的存在具有普遍性,注水速度和拐点位置均对眼球刚度系数有影响。眼内压随注水时间的拟合函数中部分拟和参数具有较明确的生理意义。     

氧分压在体监测仪的研制

作者报道一种稳定性较高的氧分压在体监测，为医学研究、临床诊断提供一种新的可靠的测试方法及设备，具有较大的应用价值。     

大鼠离体作功心脏对冠脉压强变化的反应

目的:研究离体作功心脏对其冠脉压强变化的反应.方法:采用分离式离体作功心脏模型.用上海产SJ-42型四导生理记录仪测定生理参数左心室收缩压LVSP,左心室内压上升的最大速率(dp/dt)max,冠脉流量CF,心率HR和心电图ECG.结果:离体作功心脏的工作状态受其冠脉压强变化的影响,当灌注压Pc=9 kPa时,心脏处于最佳状态.灌注压过高或过低均可导致心脏功能减弱.结论:心脏自身存在冠脉压强感受系统,在冠脉压强发生变化时,心脏自主地调节着工作状态.     

改进型在体张力传感器及在跟腱张力测定中的应用

作者对环扣式张力传感器在结构上作了改进，改单片梁为双层工字梁，改平面框架为立体异型框架，改进后的双层工字梁，立体框架张力传感器，具有灵敏度高，附加应力小，数据重复性好，能实测在体生物组织张力的特点，提出了传感器横梁高度的计算公式，并且用该传感器实测了４５只家兔跟腱的张力值，测得跟腱张力波主要有四种类型。     

在体和离体兔组织射频介电特性的测量

作者制作了同轴线传感器，根据同轴传输线反射原理，建立起计算机控制的生物组织介电测量系统，在６０～３０００ＭＨｚ频率范围对兔器官组织进行了有效在体和离体介电测量，５０只兔器官组织的统计分析结果表明，不同兔器官组织之间介电参数的最大差异可达３０．４％，在体和离体测量得出介电常数之间未见显著性差异，但电导率有频率依赖性的显著差异，因此将人体的离体介电参数延用到实际活体场合时，必须慎重。     

在体兔眼虹膜材料模型的确定

【摘 要】 目的:确定适合表征在体虹膜力学行为的材料模型。 方法:基于在体动物实验,建立眼前节有限元模型。假设虹膜材料分别为线弹性模型、Neo-Hookean模型和二阶Ogden模型,参考相应文献,设定材料参数范围,计算对应的虹膜特征点位移。基于在体实验的测量结果,利用目标函数,比较不同模型间的差异。 结果:二阶Ogden模型对应的目标函数的最小值和平均值均最小,Neo-Hookean模型次之,线弹性模型的最大。 结论:3种模型相比,二阶Ogden模型最适合用于描述在体虹膜的力学行为。     

大鼠心血管系统内血液压强分布的研究

目的研究大鼠心血管内血液压强的分布。方法实验动物采用Wistar大鼠(n=15)。在封闭条件下用4导生理记录仪记录大鼠心血管系统内各部位的血液压强。本方法较传统的液体检压计法更为精确。结果本实验得出大鼠心血管系统内血液压强的分布及其特点为(1)左室收缩压(LVSP)为(145．00±5．61)mmHg,主动脉收缩压(ASP)为(126．87±11．16)mmHg即LVSP高于ASP;右室收缩压(RVSP)为(35．04±3．95)mmHg,肺动脉收缩压(PASP)为(27．03±3．46)mmHg,即RySP高于PASP。上述血液压强的分布与人类有所差异。(2)大鼠血管系统各部位压强(包括ASP、ADP、MAP、PASP、PADP、MPAP、CVP、WP)的数值大小和变化范围大致与人类相同。结论(1)大鼠的LSP高于ASP,RVSP高于PASP,此血压分布不同于人类。(2)与人类相比,大鼠的LVSP和RPSP较高,而其血管系统各部位的血液压强的大小和分布情况大致与人类相同。     

血液微循环灌流状态的在体实验研究

血液是具有微观结构的生命流体,血液中有形成份一红细胞,白细胞和血小板,在其生命周期内,流经做血管时,发生碰撞,聚集,分离,旋转,变形等流变性征最为突出,向时由于微血管（微流场）具有舒张与收缩运动,血细胞与微流场相互作用,并形成动态耦合关系。因此体内血液微循环血流呈现出脉动性。不稳定性和随机性,微血管中血流的复杂多变状态是血液对微循环有效灌注的基础。通过动物体内实验,从微观血液流变学角度,来揭示微血管的舒缩运动,微流场中的动态耦合现象,网络流动,微血流的反馈调节机制等,对于深刻认识血液对微循环的灌…     

离体兔眼实验的建立及其初步评价

目的 建立离体兔眼实验方法,评价此实验的预测力和可靠性.方法 参照欧洲替代方法验证中心推荐的离体兔眼实验方法并结合具体条件,建立适合本实验室的离体兔眼实验方法.同步采用离体兔眼实验和兔眼刺激实验对26种受试物的眼刺激性进行检测,对2种实验分级结果的一致性和可靠性进行统计分析.结果 离体兔眼实验对26种受试物的眼刺激性分...     

The Effect of Alpha-2 Macroglobulin on the Healing of Ruptured Anterior Cruciate Ligament in Rabbits

To investigate the effect of modification of biological environmental conditions, one of the factors influencing the healing of anterior cruciate ligament rupture, we performed experimental anterior cruciate ligament ruptures on New Zealand rabbits. After experimental rupture, intra-articular alpha-2 macroglobulin was injected into the knees of the rabbits in the experiment group to prevent structural changes resulting from the enzymatic reactions in the ruptured anterior cruciate ligament. At the end of 10th day of the experiment, we observed that the anterior cruciate ligaments in the experiment group had retained their prerupture brightness and volume when compared with the control group in which intra-articular alpha-2 macroglobulin had not been injected. We also noted that the anterior cruciate ligaments in the experiment group had not retracted or swollen, the incision sites were regular and clean, and they did not show any signs of degeneration. In the histological examination, the anterior cruciate ligaments in the control groups showed disruption of the collagen network and a significant diminution in number of fibroblasts and fibrocytes (p <. 001). At the end of this study, we concluded that the necessary conditions for the healing and repair of ruptured anterior cruciate ligament could exist if the enzymatic and biological environments were under control.     

眼压测量中电磁压力控制系统的设计

目的：本文研究眼压自动测量中利用电磁驱动的压力控制系统。压力控制的精度直接影响眼压测量值的正确性,故要求能实现压力精确闭环控制。方法：根据眼压测量的实际需求,通过数值计算和ANSYS仿真相结合的方法,得到电磁驱动系统的结构参数和电磁参数;通过单片机利用12C总线和模数、数模转换,通过数字量精确控制驱动电流的大小以实现压力的闭环控制。结果：由实验测量结果可知,该电磁压力控制系统的压力范围为0N～0．48982N,精度为0．00058N,驱动电流控制的误差平均在1％左右,且在行程不变时,电磁力和激励电流呈较好的线性关系。结论：该电磁压力控制系统实现了压力的闭环控制,可控压力范围和控制精度都符合Goldmann压平眼压计的标准,为眼压自动测量仪的研制打下了基础。     

哮喘大鼠气管微循环中白细胞粘附的活体观察

哮喘大鼠气管微循环中白细胞粘附的活体观察苗会１胡清华１薛全福２新见英幸３庄逢源１支气管哮喘（简称哮喘）是当今世界常见的慢性呼吸道疾病，近年的报道表明其患病率及死亡率有上升趋势［１］。哮喘的发病机制至今尚未完全阐明。自１９８０年代提出气道慢性炎症学说以...     

In Vivo Kinematics of the Rabbit Knee in Unstable Models of Osteoarthrosis

The effects of osteoarthrosis inducing surgery on the kinematics of the rabbit knee were evaluated in vivo. A video motion analysis system was used to track reflective markers attached to two pins fixed in both femur and tibia, and from these data knee kinematics were computed. The control for all measurements was the gait after pins were implanted, but the knee was unaltered. Both a release of the anterior cruciate ligament and a partial medial meniscectomy were then performed, and the animals' gait was recorded at 4, 8 and 12 weeks after knee surgery. Knee kinematics were described by three translations and three rotations and were analyzed in terms of maximum and minimum values and range of motion. Statistical comparisons of these data between control and operated knees were made using Wilcoxon's signed rank test. Results showed an initial increase in maximum anterior displacement which returned to normal after 12 weeks. In addition there was a persistent increase in knee adduction and an increase in the minimum value of external rotation over the 12 week period. At 12 weeks after surgery there was no change in range of any measurable kinematic parameter. Overall, the changes in joint kinematics following partial medial meniscectomy and release of the anterior cruciate ligament were small, suggesting that altered joint kinematics might not be a critical factor in the development of osteoarthrosis in this animal model.     

Expression of Glutamate and GABA during the Process of Rat Retinal Synaptic Plasticity Induced by Acute High Intraocular Pressure

Acute high intraocular pressure (HIOP) can induce plastic changes of retinal synapses during which the expression of the presynaptic marker synaptophysin (SYN) has a distinct spatiotemporal pattern from the inner plexiform layer to the outer plexiform layer. We identified the types of neurotransmitters in the retina that participated in this process and determined the response of these neurotransmitters to HIOP induction. The model of acute HIOP was established by injecting normal saline into the anterior chamber of the rat eye. We found that the number of glutamate-positive cells increased successively from the inner part to the outer part of the retina (from the ganglion cell layer to the inner nuclear layer to the outer nuclear layer) after HIOP, which was similar to the spatiotemporal pattern of SYN expression (internally to externally) following HIOP. However, the distribution and intensity of GABA immunoreactivity in the retina did not change significantly at different survival time post injury and had no direct correlation with SYN expression. Our results suggested that the excitatory neurotransmitter glutamate might participate in the plastic process of retinal synapses following acute HIOP, but no evidence was found for the role of the inhibitory neurotransmitter GABA.     

Commingling Analysis of Intraocular Pressure and Glaucoma in an Older Australian Population

Purpose : To test the hypothesis of a major genetic determinant of intraocular pressure (IOP) under the mixed genetic model in a defined population, and to elucidate the relationship between IOP and glaucoma. Methods : IOP was measured in 3654 persons attending the Blue Mountains Eye Study. A commingling analysis on IOP was performed using a new program, SKUDRIVER. The goodness of fit of 1‐, 2‐ and 3‐distribution models was measured. This was repeated after the glaucoma cases had been removed from the dataset, and further repeated on the glaucoma cases in the dataset. Results : The best model was 3‐distribution with no evidence for Hardy‐Weinberg disequilibrium. The proportion of variance explained by this major effect was 0.18. When glaucoma cases were removed, the best model had 2 distributions. There was no evidence of admixture in glaucoma patients. Conclusions : The findings of this study are consistent with the presence of a major gene accounting for 18% of the variance of IOP, which could therefore influence the risk of glaucoma, in this population. These findings suggest methods of optimizing strategies for family and association studies to identify quantitative trait loci for IOP. No evidence for distinct IOP‐dependent and IOP‐independent subgroups of glaucoma was found.     

In vivo robotic capsules: determination of the number of turns of its power receiving coil

This paper introduces a strategy how to determine the number of turns of the receiving coil for in vivo robotic capsules to maximize the regulated load power. For the expected functionality additional to the endoscopic function, it is necessary to employ wireless power transmission and increase the receiving power to a maximum. The functional relation between the number of turns and the power is derived and verified by implementing a ferrite-loaded receiver coil.     

Differential effects of prenatal cocaine exposure on selected subunit mRNAs of the GABA(A) receptor in rabbit anterior cingulate cortex

We have previously shown that in the dopamine-rich anterior cingulate cortex (ACC), significant changes in γ-aminobutyric acid (GABA) immunoreactivity occur in the offspring of rabbits given intravenous injections of cocaine (3 mg/kg) twice daily during pregnancy. In the present study, the effects of prenatal cocaine exposure on the developmental expression of specific GABA_A receptor subunit mRNAs were investigated. We compared the distribution of the 1, β2, and γ2 subunit mRNAs in cocaine- and saline-treated offspring aged postnatal days 20 and 60 (P20, P60). At P20, prenatal cocaine exposure resulted in a significant increase in 1 subunit mRNA in ACC lamina III and a significant reduction in the amounts of the β2 subunit mRNA in ACC lamina II. No differences between cocaine- and saline-treated controls were detected for γ2 subunit mRNA levels in ACC. Although the pattern of labeling was altered in cocaine-exposed animals, Nissl sections revealed no differences in lamination, indicating that the changes in GABA_A subunit mRNAs could not be attributed to abnormal cytoarchitectonics. In P60 brains, no significant differences were observed between cocaine- and saline-treated material, indicating that the observed differences were transient. Collectively, our data show that prenatal cocaine exposure elicits differential, lamina-specific changes in mRNA levels encoding selected subunits of the GABA_A receptor. Since these changes occur during a critical period when fine tuning of synaptic organization is achieved by processes of selective elimination or stabilization of synapses, we suggest that specific subunit mRNAs of the GABA_A receptor play a role in cortical development.