Permanent inflation of detachable balloons with a low-viscosity, hydrophilic polymerizing system

A polymer system was developed for use in permanent inflation of detachable balloons, to avoid long-term reliance on the integrity of balloon shells or valve mechanisms. This system is based on 2-hydroxy-ethyl methacrylate (HEMA) as the monomer, in combination with a cross-linking agent and a water-soluble curing system. The low-viscosity, hydrophilic mixture can be exchanged through a small-bore catheter into a detachable balloon and polymerizes in 40-60 minutes at body temperature. Partially polymerized HEMA can cause vascular occlusion; hence, careful timing of balloon detachment is required. The evolution of the radiographic appearance of HEMA-filled balloons is predictable. The balloons remain radiopaque on plain radiographs as long as the balloon shell and valve mechanisms are competent. After rupture of the shell or failure of the valve mechanism, the balloons become invisible on plain radiographs but remain hyperattenuating on computed tomography scans.     

Problems of Psychological Monitoring in Astronaut Training

在进行职业训练时，对受训者的心理变化趋势进行监视是必要的。航天员心理因素的发展水平可通过心理测试来检测，以便能对其重要的心理指标进行评价，并给出综合评价。文中列出应进行测试的心理指标，并根据大量的样本统计给出了经验加权因子。测试结果的积累可以预测航天员将来飞行任务中处理复杂问题的能力，并能帮助改进训练过程及暴露缺点。     

水体中克雷伯菌属的分布及其在水源性急性肠道感染中的价值

俄罗斯不同气候地区不同功能水体中克雷伯菌属广泛分布。克雷伯菌属可见于遭受生物、化学污染的集中供水的地表水源,无防护的地下蓄水层,缺乏有效清洁、消毒系统的饮用水。研究表明,水体中的克雷伯菌属具有致病性和毒性,对现代药物和消毒剂(氯、紫外线)具有抗性,很容易穿透进入地下蓄水层。克雷伯菌属细菌有很强的致病性(粘附力、侵袭力、磷酸酯酶、卵磷脂酶、脱氧核糖核酸酶、溶血活性),含有致病性遗传标记cnf-1。克雷伯菌属(100 CFU/dm³)可引起急性肠道感染。在不检测总大肠菌群的情况下,检测水体尤其是饮用水中的克雷伯菌属,可以评估所用水的流行病学危险。     

重组腺病毒bcl-xs基因对人卵巢癌裸鼠移植瘤作用的研究

目的 观察重组腺病毒bcl-xs基因（adv-bcl-xs基因,简称bcl-xs基因）对人卵巢癌裸鼠移植瘤的生长抑制和荷瘤裸鼠生存率的影响。为卵巢癌的基因治疗提供实验基础。方法 采用以复制缺陷型腺病毒bcl-xs基础感染的人胚肾细胞,使bcl-xs基因对NUTU-19细胞的生长抑制作用并检测其病毒滴度后,将bxl-xs基因导入人卵巢癌裸鼠移植瘤中,观察bcl-xs基因对腹水的生长抑制作用,计算裸鼠的生存时间,并观察bcl-xs基因对裸鼠全身和局部的毒副作用。电镜观察bcl-xs基因的病毒颗粒,以免疫细胞化学染色测定bcl-xs基因表达情况。结果 bcl-xs基因可在人胚肾细胞内扩增,对NUTU-19细胞有抑制和杀伤作用。并在裸鼠体内呈过度表达,使裸鼠腹水形成的时间由5-10d延长至11-23d,裸鼠平均生存时间由24d延长至39d,bcl-xs基因对裸鼠全身和局部无明显毒副作用。结论 bcl-xs基因导入人卵巢癌裸鼠移植肿瘤,能延缓腹水形成,延长裸鼠的生存时间,为卵巢癌的基因治疗提供了一种新方法。     

Meckel''s Cave Tuberculoma with Unusual Infratemporal Extension

The authors describe a rare case of intracranial tuberculoma of the Meckel's cave and cavernous sinus with extension into the infratemporal fossa causing widening of the foramen ovale and adjacent bone destruction. The rarity of the lesion and the unusual extension of the lesion are presented with a brief review of literature.     

p53 overexpression as a marker of poor prognosis in mantle cell lymphomas with t(11;14)(q13;q32)

The t(11;14)(q13;q32) translocation, which juxtaposes the BCL1 oncogene with the Ig heavy chain locus, has been associated with an uncommon subtype of non-Hodgkin's lymphoma (NHL) termed mantle cell lymphoma (MCL). To date, no molecular marker that serves as an indicator of tumor progression or clinical prognosis has been described for NHLs with this translocation. We examined a panel of NHLs with t(11;14) for overexpression of p53 and correlated the results with single-strand conformation polymorphism (SSCP) analysis, karyotypic features, and clinical course. NHLs with t(11;14) were identified from 30 patients. The diagnosis was MCL for 23 of 30, small lymphocytic lymphoma for 4 of 30, and diffuse large-cell lymphoma for 3 of 30 cases. The results of immunohistochemistry analysis using a monoclonal anti-p53 antibody on paraffin-embedded specimens were compared with the SSCP data, the tumor karyotypes, and clinical course of each patient. DNA sequencing of exons was performed on cases that showed conformational changes by SSCP analysis. NHLs from 5 of 23 patients with MCL were positive for p53 overexpression. Deletions of chromosome 17p were identified in 2 of 30 cases, both of which were MCLs showing p53 overexpression. Two of the five MCLs with p53 overexpression showed evidence for TP53 mutations. None of the 18 MCLs negative for p53 overexpression showed conformational changes by SSCP. For these 18 patients with MCLs that did not overexpress p53, the median survival was 63 months, compared with 12 months for the 5 patients with MCLs positive for p53 overexpression (P < .001). These results suggest that p53 overexpression in MCL with t(11;14)(q13;q32) may serve as a marker of poor prognosis.     

NS11021, a novel opener of large-conductance Ca2+-activated K+ channels,enhances erectile responses in rats

Background and purpose:

Large-conductance Ca²⁺-activated K⁺ channels (BK_Ca), located on the arterial and corporal smooth muscle, are potential targets for treatment of erectile dysfunction (ED). This study investigated whether NS11021 (1-(3,5-Bis-trifluoromethyl-phenyl)-3-[4-bromo-2-(1H-tetrazol-5-yl)-phenyl]-thiourea), a novel opener of BK_Ca channels, relaxes erectile tissue in vitro and enhances erectile responses in intact rats. The effects were compared with sildenafil, an inhibitor of phosphodiesterase type 5.

Experimental approach:

Patch clamp was used to record whole cell current in rat isolated corpus cavernosum smooth muscle cells (SMCs) and human umbilical vein endothelial cells (HUVECs). Isometric tension was measured in intracavernous arterial rings and corpus cavernosum strips isolated from rats and men, and simultaneous measurements of intracellular Ca²⁺ concentration ([Ca²⁺]_i) and tension were performed in intracavernous arteries. Erectile response was measured in anaesthetized rats.

Key results:

In patch clamp recordings, NS11021 increased currents sensitive to the selective BK_Ca channel blocker, iberiotoxin (IbTX) in SMCs, but did not modulate K⁺ current in HUVECs. NS11021 reduced [Ca²⁺]_i and tension in penile arteries. IbTX inhibited the vasorelaxation induced by NS11021 and sildenafil in human erectile tissue. NS11021 and sildenafil but not vehicle increased erectile responses in anaesthetized rats, an effect which was abolished after pretreatment with tetraethylammonium.

Conclusions and implications:

NS11021 leads to relaxation of both intracavernous arteries and corpus cavernosum strips primarily through opening of BK_Ca channels. It is also effective in facilitating erectile responses in anaesthetized rats. These results suggest a potential for use of BK_Ca openers in the treatment of ED.     

Stress suppresses and learning induces plasticity in CA3 of rat hippocampus: a three-dimensional ultrastructural study of thorny excrescences and their postsynaptic densities

Chronic stress and spatial training have been proposed to affect hippocampal structure and function in opposite ways. Previous morphological studies that addressed structural changes after chronic restraint stress and spatial training were based on two-dimensional morphometry which does not allow a complete morphometric characterisation of synaptic features. Here, for the first time in such studies, we examined these issues by using three-dimensional (3-D) reconstructions of electron microscope images taken from thorny excrescences of hippocampal CA3 pyramidal cells. Ultrastructural alterations in postsynaptic densities (PSDs) of thorny excrescences receiving input from mossy fibre boutons were also determined, as were changes in numbers of multivesicular bodies (endosome-like structures) within thorny excrescences and dendrites. Quantitative 3-D data demonstrated retraction of thorny excrescences after chronic restraint stress which was reversed after water maze training, whilst water maze training alone increased thorny excrescence volume and number of thorns per thorny excrescence. PSD surface area was unaffected by restraint stress but water maze training increased both number and area of PSDs per thorny excrescence. In restrained rats that were water maze trained PSD volume and surface area increased significantly. The proportion of perforated PSDs almost doubled after water maze training and restraint stress. Numbers of endosome-like structures in thorny excrescences decreased after restraint stress and increased after water maze training. These findings demonstrate that circuits involving contacts between mossy fibre terminals and CA3 pyramidal cells at stratum lucidum level are affected conversely by water maze training and chronic stress, confirming the remarkable plasticity of CA3 dendrites. They provide a clear illustration of the structural modifications that occur after life experiences noted for their different impact on hippocampal function.