Cold-passaged isolates and bat-swine influenza a chimeric viruses as modified live-attenuated vaccines against influenza a viruses in pigs

Swine influenza A virus (swIAV) infections in pig populations cause considerable morbidity and economic losses. Frequent reverse zoonotic incursions of human IAV boost reassortment opportunities with authentic porcine and avian-like IAV in swine herds potentially enhancing zoonotic and even pre-pandemic potential. Vaccination using adjuvanted inactivated full virus vaccines is frequently used in attempting control of swIAV infections. Accelerated antigenic drift of swIAV in large swine holdings and interference of maternal antibodies with vaccine in piglets can compromise these efforts. Potentially more efficacious modified live-attenuated vaccines (MLVs) bear the risk of reversion of MLV to virulence. Here we evaluated new MLV candidates based on cold-passaged swIAV or on reassortment-incompetent bat-IAV-swIAV chimeric viruses. Serial cold-passaging of various swIAV subtypes did not yield unambiguously temperature-sensitive mutants although safety studies in mice and pigs suggested some degree of attenuation. Chimeric bat-swIAV expressing the hemagglutinin and neuraminidase of an avian-like H1N1, in contrast, proved to be safe in mice and pigs, and a single nasal inoculation induced protective immunity against homologous challenge in pigs. Reassortant-incompetent chimeric bat-swIAV vaccines could aid in reducing the amount of swIAV circulating in pig populations, thereby increasing animal welfare, limiting economic losses and lowering the risk of zoonotic swIAV transmission.     

小颗粒致密低密度脂蛋白氧化特性及对血管内皮细胞脂质过氧化的影响

了解小颗粒致密低密度脂蛋白中抗氧化维生素含量、氧化特性 ,探讨其对血管内皮细胞脂质过氧化的影响。采用二次密度梯度超速离心的方法分离制备小颗粒致密低密度脂蛋白 ,高压液相色谱测定其抗氧化物质维生素A、E和 β 胡萝卜素 ;连续监测小颗粒致密低密度脂蛋白在 2 34nm的吸光度以测定其氧化敏感曲线 ;在血管内皮培养液中分别加入不同浓度的小颗粒致密低密度脂蛋白 ,培养后测定培养液丙二醛的浓度。实验成功分离小颗粒致密低密度脂蛋白 ,与大而轻低密度脂蛋白相比 ,维生素A、E和 β 胡萝卜素等抗氧化物质及总抗氧化能力明显减少 ,只有大而轻低密度脂蛋白的 6 5 %、39%和 2 4 % ,故小颗粒致密低密度脂蛋白氧化的延迟时间只有大而轻低密度脂蛋白的 37.5 % ,但硫代巴比妥酸反应物质值及氧化速率分别是大而轻低密度脂蛋白的 1 .7倍和 1 .2 8倍 ;培养液中丙二醛含量随加入脂蛋白的浓度和作用时间而增高 ,2 4h时小颗粒致密低密度脂蛋白 5 0mg组、1 0 0mg组、1 5 0mg组与相同剂量大而轻低密度脂蛋白组比较丙二醛显著增高 (P <0 .0 5 )。上述结果提示 :小颗粒致密低密度脂蛋白中抗氧化物质及抗氧化能力下降 ,氧化敏感性增高 ,并促进内皮细胞过氧化损伤     

改良的HAMPT方案治疗难治性急性淋巴细胞性白血病

我们将常规的ＨＡＭＰＴ方案中的氨甲喋呤（ＭＴＸ）剂量改为大剂量组成良的ＨＡＭＰＴ方案治疗难治性急性淋巴细胞白血病（ＡＬＬ）２０例，１７例完全缓解，３例部分缓解。其中１６／１７例一疗程则获完全缓解（ＣＲ），ＣＲ率８５％，诱导缓解时间平均１７天。本方案疗效较满意，副作小用，可作为难治作ＡＬＬ治疗的较好方法。     

荷包环扎式结直肠吻合保肛术治疗低位直肠癌*

目的 :评价荷包环扎式结直肠吻合保肛术治疗低位直肠癌的价值。方法 :对低位直肠癌采用荷包环扎结直肠吻合保肛术治疗 2 3例 (A组 ) ,采用Miles手术治疗 2 6例 (B组 )。结果 :A组术后 1、3年生存率分别为 10 0 % (2 3/ 2 3) ,95 7% (2 2 / 2 3) ,术后无局部复发病例 ;排便功能优 16例 (6 9 6 % ) ,良 7例 (30 4 % )。B组术后 1、3年生存率分别为 10 0 % (2 6 / 2 6 ) ,96 2 % (2 5 /2 6 ) ,术后局部复发率 3 8% (1/ 2 6 )。两组术后 1、3年生存率 ,局部复发率经统计检验 ,均无显著差异 (P值均 >0 0 5 )。术后并发症 :A组无吻合口瘘及吻合口狭窄发生 ,盆腔感染 1例。B组 :切口感染 1例 ,人工肛门狭窄 1例。结论 :采用螺纹支架管荷包环扎结直肠吻合保肛术治疗低位直肠癌既能达到根治目的 ,又有保留肛门的良好排便功能 ,且并发症少 ,操作简便易行 ,不用特殊器械 ,值得推广应用     

Cutaneous afferent activity in the median nerve during grasping in the primate

Neural activity was recorded from the median nerve of a monkey during grasping and lifting, using a chronically implanted cuff electrode. At the onset of lifting, there was an initial dynamic response during which the intensity of the neural signal increased rapidly. This neural response attained its peak value well before the displacement, the load force or the grip force. The time course and peak of the rectified, integrated neurogram were best correlated with the rate of change of grip force. The neural activity declined exponentially to a steady value following the initial peak. During steady holding the mean amplitude of the neurogram was best correlated with the mean grip force. At the end of the holding phase there was a short burst of neural activity as the monkey relaxed the grip force and released the object. During some blocks of trials pulse perturbations were applied to the object. When the monkey did not increase the grip force in advance of the perturbation, the perturbation produced a relatively large displacement of the object and a burst of neural activity whose onset coincided with the onset of displacement. When the monkey anticipated the perturbation by increasing the grip force during the holding period preceding the perturbation, the perturbation produced a relatively small displacement and relatively little increase in neural activity.     

使用新型倒刺电极的骶神经调节治疗神经源性膀胱的初步临床结果

目的探讨应用新型倒刺电极（Tined-lead）对神经源性膀胱患者行S骶神经调节（SNM）的初步疗效。方法对5例神经源性膀胱患者采用新型倒刺电极，在X线监测下将电极植入S3骶神经孔，进行SNM。术前、术后详细记录排尿日记，用影像尿动力学方法评估患者的膀胱尿道功能。结果患者1（隐性骶裂）术后排尿次数和排尿量分别改善22％和49％；患者2（隐性骶裂）术后排尿次数、排尿量和残余尿量分别改善0．7％、11％和46％；患者3（隐性骶裂）术后排尿次数、排尿量和残余尿量分别改善0．4％、18％和44％。患者4（脑外伤）术后漏尿次数和漏尿量分别改善36％和54％。患者5（高位截瘫）术后间歇导尿次数和导尿量分别改善42％和54％，尿动力学参数改善37％～45％。结论用新型倒刺电极进行SNM为神经源性膀胱的治疗提供了一条新的可供选择的微创方法。     

氨气敏电极法快速测定血氨

本文介绍使用氨气敏电极,采用标准曲线法简便、快速、准确测定血氨的方法。取空腹血1ml,用1M HClO_4沉淀蛋白,以0.1M NH_4Cl—0.6MNa_2SO_4作内充液,碱化后的上清液可在2～3min内测试完毕。40例正常成人血氨的测定结果:■=31.4μmol/L N;S=6.4μmol/L N;■±2S(正常值范围)为18.6～44.2μmol/L N。10份血样的平均回收率为100.4％。该法用血少、简便、快速;结果较稳定、准确,适用于临床检验。     

The growth of the second underpotentially deposited silver layer on Pt(100)

The electrodeposition of Ag on Pt(100)-(1 × 1) in perchlorate electrolyte was studied by means of time-resolved in situ scanning tunnelling microscopy (STM) and cyclic voltammetry. One monolayer of Ag is deposited underpotentially (upd) ca. 500 mV positive of the Ag⁺/Ag equilibrium potential. Several millivolts positive of the equilibrium potential, a second well defined upd layer forms. Its growth was observed to proceed via island formation and coalescence. This process occurs in two separate stages that manifest themselves in voltammetric peaks as well as in the STM images.