Effects of high and low inspired fractions of oxygen on horse erythrocyte membrane properties, blood viscosity and muscle oxygenation during anaesthesia

ObjectivesTo evaluate whether a period of hyperoxia or after a period of hypoxia produced changes attributable to reactive oxygen species in anaesthetized horses.Study designProspective randomized experimental study.AnimalsSix healthy (ASA I) geldings, aged 4.5–9.5 years and weighing 510–640 kg^?1.MethodsAfter 30 minutes breathing air as carrier gas for isoflurane, horses were assigned randomly to breathe air as carrier gas (CG0.21) or oxygen as carrier gas (CG1.00) for a further 90 minutes. After an interval of 1 month each horse was re-anaesthetized with the other carrier gas for the 90 minute test period. Ventilation was controlled throughout anaesthesia. Arterial blood was sampled to measure gas tensions, lactate, cholesterol, vitamin E, 4-hydroxy-alkenals, 8-epi-PGF_2α, half haemolysis time, half erythrolysis time, and erythrocyte membrane fluidity. Muscle blood flow and oxygenation were evaluated by near infrared spectroscopy and coloured Doppler.ResultsAfter the first 30 minutes horses were hypoxemic. Subsequently the CG1.00 group became hyperoxaemic (PaO₂～240 mmHg) whereas the CG0.21 group remained hypoxaemic (PaO₂～60 mmHg) and had increased lactate concentration. No significant changes in vitamin E, 4-hydroxy-alkenals, or 8-epi-PGF_2α concentrations were detected. During the 90 minute test period the CG0.21 group had increased resistance to free-radical-mediated lysis in erythrocytes, whereas the CG1.00 group had slightly decreased resistance of whole blood to haemolysis. CG0.21 induced a progressive muscle deoxygenation whereas CG1.00 induced an increase in muscle oxygen saturation followed by progressive deoxygenation towards baseline.Conclusions and clinical relevanceDuring isoflurane anaesthesia in horses, the hyperoxia induced by changing from air to oxygen induced minimal damage from reactive oxygen species. Using air as the carrier gas decreased skeletal muscle oxygenation compared with using oxygen.     

Effects of IL-32γ on proliferation and cell cycle of rat vascular smooth muscle cells

AIM: To observe the effects of interleukin-32γ (IL-32γ)on the proliferation and cell cycle of rat vascular smooth muscle cells (VSMCs). METHODS: The VSMCs were isolated from the thoracic aorta of SD rats by the method of tissue-piece inoculation. The cells were cultured and treated with different concentrations of IL-32γ. The proliferation of the cells was examined by MTT assay. The cell cycles were analyzed by flow cytometry. The protein levels of NF-κB p65 and cyclin D1 were detected by Western blotting. The expression of proliferating cell nuclear antigen (PCNA)was examined by immunocytochemical staining. RESULTS: Administration of IL-32γ at the concentrations of 10~50 μg/L for 24~48 h significantly promoted the proliferation of VSMCs in a dose- and time-dependent manner. After stimulation with IL-32γ at the concentration of 50 μg/L for 24 h, the cell cycle transition from G₁ phase to S/G₂ phase was accelerated and the expression levels of NF-κB p65, cyclin D1 and PCNA increased as compared with those in control group. CONCLUSION: IL-32γ promotes the proliferation of rat VSMCs and accelerates the cell cycle transition via upregulating the expression of NF-κB p65 and cyclin D1.     

Expression of alpha-smooth muscle actin in scar tissue and its relationship with apoptosis

AIM: To examine the expression of alpha-smooth muscle actin in scar tissue, and observe the phenomenon of apoptosis and its involvement in the process of pathological scarring and the presence of myofibroblasts or absence of cell in the dermis. To investigate the potential role of reparative cell apoptosis in hyperplastic scar formation. METHODS: The samples of scar were obtained from post-burn patients undergoing plastic operation in our burn unit recently, and the samples of control came from skin donor site of the same patient correspondingly. TUNEL assays were performed to evaluate the number of apoptotic cells in scar versus normal skin. In situ hybridization and immunohistochemistry staining technique were employed to determine the expression of different dermis cells markers in scar tissue and normal skin. RESULTS: There existed evident difference in apoptotic cells in the dermis between scars tissue and normal human skin. The expression positive cells were much more in hyperplastic scars than that in normal human skin; the apoptotic cells of proliferative stage were slight more than that of mature stage. However, in proliferative stage, the number of apoptotic cells was higher for the combination of hyperplastic scar than normally healed flat scars. But in mature stage, no obviously difference was detected between hyperplastic scar and normally healed flat scar. The monoclonal anti-α smooth muscle actin (ASMA) expression was significantly stronger in proliferative stage than that of mature stage. CONCLUSIONS: With reconstitution of dermal tissue, myofibroblasts containing alpha-SM actin disappear under normal wound healing, probably as a result of apoptosis. The myofibroblast play a critical role in wound closure and in the pathologic sequelae of healing.     

Inhibitory effect of 1,25-(OH)2D3 on proliferation of airway smooth muscle cells from passively-sensitized patients

AIM: To investigate the effects of 1,25-dihydroxyvitamin D₃ on the proliferation of passively-sensitized human airway smooth muscle cells (HASMCs), and to explore its potential role in asthmatic airway remodeling.METHODS: HASMCs were passively sensitized with 10% serum from asthmatic patients.1,25-(OH)₂D₃ was used as the interventor.The effect of 1,25-(OH)₂D₃ on the cell proliferation and its optimal concentration were determined by MTT colorimetric assay.The cell cycle analysis was performed by flow cytometry.The expression of proliferating cell nuclear antigen (PCNA) was measured by the method of immunocytochemical staining.RESULTS: 1,25-(OH)₂D₃ at the concentrations of 10^-9-10^-7 mol/L markedly inhibited the cell proliferation and the maximum effect was observed at the concentration of 10^-7 mol/L.This concentration of 1,25-(OH)₂D₃ markedly suppressed the PCNA-positive rate and hampered the G₁/S transition in HASMCs passively-sensitized by asthmatic serum.CONCLUSION: 1,25-(OH)₂D₃ has direct inhibitory effects on the proliferation of passively-sensitized HASMCs in vitro, which may be concerned with the beneficial role of 1,25-(OH)₂D₃ on the prevention and therapy of asthmatic airway remodeling.     

茶叶渣菌酶协同发酵饲料对青脚麻鸡生长性能、屠宰性能及肌肉风味的影响

试验旨在研究饲粮添加不同水平茶叶渣菌酶协同发酵饲料对肉鸡生产性能、屠宰性能和肌肉风味的影响.1080只25日龄青脚麻鸡随机分成5个组,每组6个重复,每重复36只.对照组饲喂基础日粮,试验Ⅰ组在基础日粮基础上添加5％的菌酶协同发酵饲料,试验Ⅱ、Ⅲ、Ⅳ组添加1％、3％、5％的茶叶渣菌酶协同发酵饲料,试验期为28 d.结果 ...     

夹竹桃花挥发油的GC-MS分析及β-葡萄糖苷酶对夹竹桃花的增香和豚鼠离体子宫平滑肌的作用

目的:建立夹竹桃花挥发油GC-MS的色谱分离鉴定方法,分析夹竹桃花挥发油的化学成分和对豚鼠离体子宫平滑肌的作用。方法:采用挥发油提取器提取夹竹桃花挥发油,以GC-MS法进行分析鉴定,建立了豚鼠离体子宫模型。结果:分别从无酶和有酶的夹竹桃花挥发油提取物中确证了58和57个化合物,挥发油对豚鼠离体子宫平滑肌有收缩作用。结论:对夹竹桃的挥发油化学成分进行了比较分析结果表明,β-葡萄糖苷酶对夹竹桃花有较弱增香作用,也能增加豚鼠离体子宫平滑肌收缩。     

A STATIC STRESS ANALYSIS OF THE EFFECT OF STRATIFICATION PLANE OF ROCK MASSES ON SMOOTH BLASTING

The influenfial factors of stratification plane to smooth blasting are studied according to the ti eory of smooth blasting and the anslysis of static stress. The results show that the angle p between the maximum principal plane and the rertical line of stratification plane has some influence on the fracture of rock masses.     

气动肌肉肘关节MPI迟滞模型与补偿控制

针对气动肌肉驱动的四连杆肘关节输入气压与输出角度间的迟滞进行分析。建立肘关节迟滞的PrandtlIshlinskii(PI)模型,采用Levenberg-Marquardt方法辨识模型参数;选择改进Play算子合适的包络函数,设计一种可描述非对称迟滞现象的改进PI(Modified PI,MPI)模型,相较于传统PI模型(Classical PI,CPI),MPI模型对非对称迟滞曲线拟合度更高。基于MPI模型,设计前馈积分逆补偿器,并与PID组成积分逆补偿控制器(MPI-I-I-PID);完成了MPI-I-I-PID、PID与基于CPI模型的积分逆补偿PID控制器(CPI-I-I-PID)的位置控制仿真。仿真结果表明,MPI-I-I-PID可以减小跟踪误差,提高跟踪精度。在不同负载下进行了控制实验,实验结果表明,随着负载增加,补偿效果减弱,为此在补偿器中加入分段PID,MPI-I-I-pPID可减小抖动幅度,降低肘关节跟踪误差,提高位置控制精度和稳定性,验证了迟滞补偿器的有效性。     

表面增强拉曼光谱快速检测生鲜肉中的瘦肉精

为了快速检测生鲜肉中的瘦肉精,该研究利用表面增强拉曼光谱技术,以沙丁胺醇为检测目标物,建立了一种快速检测肌肉组织和肝脏中瘦肉精含量的方法。在碱性环境下利用乙酸乙酯对样品中沙丁胺醇进行提取,采用Savitzky-Golay 5点平滑法和自适应迭代重加权惩罚最小二乘法消除光谱噪声以及荧光背景对分析建模的影响。为检测方法的重复性,对50个相同沙丁胺醇质量分数(1 mg/kg)的肌肉组织样品进行信号采集,对沙丁胺醇特征峰强度进行分析,621、814、1 253、1 489、1 609 cm~(-1) 5个特征峰强度的相对标准偏差(RSD)为6.54%、6.07%、8.65%、7.44%、6.81%,说明该方法具有较好的重复性。建立沙丁胺醇标准溶液的预测模型,沙丁胺醇浓度与其特征峰强度相关性较好,决定系数R~2为0.968。对肌肉组织和肝脏中沙丁胺醇含量进行检测,检测范围分别为0.01~5和0.02~5 mg/kg,检出限分别为0.01和0.02 mg/kg,其含量与预测实测值决定系数为0.912和0.921。研究表明,该方法可以实现肌肉组织和肝脏中沙丁胺醇含量的定量预测。