摘除松果体对大鼠学习记忆及基底前脑胆碱能系统的影响

目的　探讨松果体功能减退对大鼠学习记忆及基底前脑胆碱能系统的影响。方法　选用 3月龄SD大鼠 2 4只 ,随机分为对照组、去松果体组和褪黑素 (MT)组。手术摘除松果体。饲养 1个月后用Morris水迷宫测试学习记忆功能 ,同时用组织化学和免疫组化方法测定海马、前额叶皮质AchE纤维和内侧隔核、斜角带核的ChAT神经元的数量。结果　与对照组比较 ,去松果体组逃避潜伏期明显增加 ,海马、前额叶皮质AchE纤维数量明显减少 ,但内侧隔核、斜角带核的ChAT神经元数量变化不明显。结论　大鼠去松果体可引起大鼠学习记忆能力减弱 ,这可能与基底前脑胆碱能神经元的功能下降有关     

医学图像光线投影体绘制中一种改进的快速算法

光线投影算法是体绘制算法中图像效果比较好的方法，但存在运算量大，绘制速度慢的问题。为此本文提出了一种新的光线投影体绘制的加速算法，利用重采样点在两坐标系中的矩阵变换特性。减少矩阵运算量，加快重采样计算过程，并且通过将Bresenham算法扩展至三维，利用包围盒技术避免对空体元的采样，从而加速了光线投影的效率。实验结果表明改进后的加速算法，既能保证绘制质量，又能显著减少计算量，提高体绘制的速度。     

大鼠失血性休克对内毒素诱导TNFα产生的影响及其分子机制

笔者观察了大鼠失血性休克（ＨＳ）对内毒素诱导肿瘤坏死因子α（ＴＮＦα）产生的影响及其细胞来源，并结合休克后组织内脂多糖结合蛋白（ＬＢＰ）ｍＲＮＡ的表达变化，对其分子机制进行了初步分析。研究结果显示，静脉注射ＬＰＳ后９０ｍｉｎ，ＨＳ＋ＬＰＳ组血浆ＴＮＦα水平分别较ＨＳ组高２０倍（Ｐ＜０．０１），ＬＰＳ组高２．７倍（Ｐ＜０．０５）；休克和复苏后，外周血白细胞产生ＴＮＦα的能力明显受抑，而肝Ｋｕｐｆｅｒ＇ｓ细胞产生ＴＮＦα的能力却明显增强；休克后不仅肝组织内ＬＢＰｍＲＮＡ表达增多，肺、肾组织内ＬＢＰｍＲＮＡ也相继表达增加。研究结果提示，失血性休克能显著增敏内毒素诱导ＴＮＦα的产生作用，其机制可能与休克后组织内ＬＢＰ表达上调有关，组织巨噬细胞群（如Ｋｕｐｆｅｒ细胞）可能是休克后细胞因子产生的主要来源。     

壳聚糖醋酸溶液对凝血作用的研究

研究了不同脱乙酰度和不同分子量壳聚糖醋酸溶液的凝血作用。发现壳聚糖醋酸溶液使抗凝血液中红细胞发生了明显的聚集和变形。通过不同分子量和脱乙酰度壳聚糖的促红细胞聚集实验,证明了低脱乙酰度壳聚糖(60%~70%)使红细胞聚集效果更好,分子量在105~106范围内作用不十分明显。对血液的凝血酶时间(TT)、凝血酶原时间(PT)、活化部分促凝血酶原激酶时间(APTT)和纤维蛋白原浓度(FIB)的测定结果验证了壳聚糖醋酸溶液凝血机理不依赖于血小板和常规“瀑布”凝血机制。     

Pleiotropic genomic variants at 17q21.31 associated with bone mineral density and body fat mass: a bivariate genome-wide association analysis

Osteoporosis and obesity are two severe complex diseases threatening public health worldwide. Both diseases are under strong genetic determinants as well as genetically correlated. Aiming to identify pleiotropic genes underlying obesity and osteoporosis, we performed a bivariate genome-wide association (GWA) meta-analysis of hip bone mineral density (BMD) and total body fat mass (TBFM) in 12,981 participants from seven samples, and followed by in silico replication in the UK biobank (UKB) cohort sample (N = 217,822). Combining the results from discovery meta-analysis and replication sample, we identified one novel locus, 17q21.31 (lead SNP rs12150327, {"type":"entrez-nucleotide","attrs":{"text":"NC_000017.11","term_id":"568815581"}}NC_000017.11:g.44956910G > A, discovery bivariate P = 4.83 × 10⁻⁹, replication P = 5.75 × 10⁻⁵) at the genome-wide significance level (ɑ = 5.0 × 10⁻⁸), which may have pleiotropic effects to both hip BMD and TBFM. Functional annotations highlighted several candidate genes, including KIF18B, C1QL1, and PRPF19 that may exert pleiotropic effects to the development of both body mass and bone mass. Our findings can improve our understanding of the etiology of osteoporosis and obesity, as well as shed light on potential new therapies.Subject terms: Genome-wide association studies, Gene expression profiling     

Protective efficacy in chickens, geese and ducks of an H5N1-inactivated vaccine developed by reverse genetics

We generated a high-growth H5N1/PR8 virus by plasmid-based reverse genetics. The virulence associated multiple basic amino acids of the HA gene were removed, and the resulting virus is attenuated for chickens and chicken eggs. A formalin-inactivated oil-emulsion vaccine was prepared from this virus. When SPF chickens were inoculated with 0.3 ml of the vaccine, the hemagglutinin-inhibition (HI) antibody became detectable at 1 week post-vaccination (p.v.) and reached a peak of 10log2 at 6 weeks p.v. then slowly declined to 4log2 at 43 weeks p.v. Challenge studies performed at 2, 3 and 43 weeks p.v. indicated that all of the chickens were completely protected from disease signs and death. Ducks and geese were completely protected from highly pathogenic H5N1 virus challenge 3 weeks p.v. The duration of protective immunity in ducks and geese was investigated by detecting the HI antibody of the field vaccinated birds, and the results indicated that 3 doses of the vaccine inoculation in geese could induce a 34 weeks protection, while 2 doses induced more than 52 weeks protection in ducks. We first reported that an oil-emulsion inactivated vaccine derived from a high-growth H5N1 vaccine induced approximately 10 months of protective immunity in chickens and demonstrated that the oil-emulsion inactivated avian influenza vaccine is immunogenic for geese and ducks. These results provide useful information for the application of vaccines to the control of H5N1 avian influenza in poultry, including chickens and domestic waterfowl.     

The role of dorsal respiratory group neurons studied with cross-correlation in the decerebrate rat

We examined the role of dorsal respiratory group (DRG) inspiratory neurons as transmitters of respiratory drive to phrenic and intercostal motoneurons and as relays of afferent information to ventral respiratory group (VRG) bulbospinal, inspiratory neurons. Attempts to antidromically activate 76 DRG neurons from the spinal cord at the C7 segment resulted in only 4 (5.3%) successes (3 contralateral, 1 ipsilateral). Cross-correlating DRG neuron discharge with that of the ipsilateral (56) and contralateral (20) phrenic nerve detected common activation peaks in 2 and 3 cases respectively, with no evidence for monosynaptic connections. Cross-correlating DRG neuron discharge with that of bulbospinal, inspiratory VRG neurons found some evidence for interaction. Peaks in 7 of 73 (10%) cross-correlation histograms were attributed to a monosynaptic excitation of DRG neurons by VRG neurons, although a common activation cannot be ruled out; troughs, some with an accompanying peak, in 9 (12.3%) histograms were interpreted as a combined excitation of the DRG neuron and delayed inhibition of the VRG neuron. In addition, 2 cross-correlation histograms showed peaks with latencies and half-amplitude widths consistent with a disynaptic excitation of a DRG neuron by a bulbospinal inspiratory VRG neuron. Cross-correlating the discharge of 57 pairs of DRG inspiratory neurons (6 contralateral) detected common activation peaks in 7 (12.3%) cases (none contralateral) and one case interpreted as evidence for a disynaptic excitation. These findings suggest that the role of the DRG inspiratory neurons in rats differs from that in cats, primarily because they do not act to transmit respiratory rhythmic drive directly to phrenic and intercostal motoneurons. The results offer some support for an excitation of DRG neurons by VRG inspiratory neurons, but no support for a role of DRG inspiratory neurons as mediators of afferent information transfer to VRG bulbospinal inspiratory neurons.     

长期慢性脑外伤大鼠脑线粒体功能的变化

研究长期慢性轻度脑外伤对大鼠脑线粒体功能的影响。大鼠连续1、5、10、15、20、25、30d轻度闭合性颅脑撞击后分离脑线粒体,测定线粒体肿胀度、膜流动性、膜磷脂含量、呼吸功能、线粒体呼吸酶、超氧化物歧化酶(SOD)、丙二醛(MDA)和Ca2 等指标以显示线粒体功能、抗氧化能力的变化。结果显示,第15、20、25、30d大鼠脑线粒体明显肿胀,膜磷脂降解,膜流动性下降,呼吸功能衰减,呼吸酶、SOD活性降低,Ca2 、MDA含量升高。由此认为,经常性头部撞击可造成大鼠脑线粒体功能受损,其机制可能与脑线粒体膜损伤后继发的自由基生成增加、脑线粒体能量代谢障碍有关。