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61.
Spermine and spermidine, ubiquitous polyamines present in bacteria and animal cells, are also involved in cell growth. Since they interact with the double helix, they can stabilize the DNA molecule. Recent evidence of the antimutagenic and anticarcinogenic capacity of spermine has focused attention on the mechanism(s) by which such agents can protect cells from induced damages. In the present paper we show the ability of spermine and spermidine to decrease the level of sister chromatid exchanges induced in Chinese hamster ovary cells cultivated in vitro, by treating them with Psoralen + UVA irradiation (able to induce mainly monoadducts and DNA cross-links). Two different mechanisms of polyamine action can be invoked to explain the preservative activity of this class of agents. 相似文献
62.
膳食结构的变化对脂肪肝患者疗效观察 总被引:4,自引:0,他引:4
目的 通过营养干预改变脂肪肝患的膳食结构和生活方式,并观察其疗效。方法 营养干预措施采用询问法登记摄入食物的种类和数量,制订膳食原则及编制食谱。健康教育进行营养知识讲座及咨询活动。结果 通过营养干预脂肪肝患改变了原有的膳食结构及饮食习惯,能量摄入和消耗处于动态平衡;增加粗粮、蔬菜和鱼禽类等食品的摄入量,动物性脂肪摄入减少;53.1%脂肪肝患有好转,46.2%超重或肥胖的人体重恢复到标准体重范围内。结论 普及营养知识,养成良好的饮食和生活习惯,防止食源性疾病的发生。 相似文献
63.
[目的]探讨人体内锌缺乏与年龄是否相关。[方法]采集头发用强酸消化后,利用北京振教科贸有限公司产WL-3微量元素分析仪进行检测。[结果]我们发现儿童的缺锌率高于青少年和成人人群,具有显著的统计学意义(P〈0.05),其中3~5岁时的儿童的缺锌率达到了79.1%。而青少年与成人之间的缺锌率并无差异(P〉0.05),分别为20.5%和18.4%。[结论]因膳食结构不当引起锌缺乏在儿童中常见,由此我们应当根据不同年龄阶段特点进行不同的补锌措施。 相似文献
64.
J Goldhahn M Reinhold M Stauber C Knop R Frei E Schneider B Linke 《Journal of orthopaedic research》2006,24(5):917-925
The goal of our study was to evaluate two newly developed implant designs and their behavior in terms of subsidence in lumbar vertebral bodies under cyclic loading. The new implants were evaluated in two different configurations (two small prototypes vs. one large prototype with similar load-bearing area) in comparison to a conventional screw-based implant (MACS TL). A pool of 13 spines with a total of 65 vertebrae was used to establish five testing groups of similar bone mineral density (BMD) distribution with eight lumbar vertebrae each. In additional to BMD assessment via dual-energy X-ray absorptiometry, cancellous BMD and structural parameters were determined using a new generation in vivo 3D-pQCT. The specimens were loaded sinusoidally in force control at 1 Hz for 1000 cycles at three load levels (100, 200, and 400 N). A survival analysis using the number of cycles until failure (Cox regression with covariates) was applied to reveal differences between implant groups. All new prototype configurations except the large cylinder survived significantly longer than the control group. The number of cycles until failure was significantly correlated with the structural parameter Tb.Sp. and similarly with the cancellous BMD for three of five implants. In both large prototypes the cycle number until failure significantly correlated with the preoperative distance to the upper endplates. Although the direct relationship between bone structure or density and mechanical breakage behavior cannot be conclusively proven, all the prototypes adapted for poor bone structure performed better than the comparable conventional implant. 相似文献
65.
目的:探讨阻塞性睡眠呼吸暂停综合征(obstructive sleep apnea syndrome,OSAS)患者手术治疗的麻醉处理。方法:72例OSAS患者手术前先正压通气治疗(continue positive airway pressure,CPAP)和评价上气道,55例患者经鼻或经口气管插管全身麻醉;在手术完毕患者完全清醒后拔除插管。结果:72例患者中,轻度16例、中度24例、重度32例。合并晨起高血压28例,心电图均有不同程度心肌缺血的表现;红细胞增多症12例;腭咽平面Ⅰ级9例、Ⅱ级24例、Ⅲ级的27例、Ⅳ级12例。术前3.5d行自动调压正压通气治疗(Auto—CPAP),经口气管内插管48例,经鼻气管内插管6例,均无术中插管困难和术后高血压危象,呼吸道梗阻发生。结论:充分认识OSAHS患者全身麻醉的手术风险,术前CPAP治疗和上气道评估,术中正确处理、严格掌握气管内插管、术后拔管的时机,是保证OSAHS患者手术成功、麻醉安全的关键。 相似文献
66.
目的 分析富含三酰甘油脂蛋白(TRLs)分子组成及其代谢特征.方法应用脂蛋白电泳技术,对30例飞行员空腹和脂肪负荷餐后血浆做脂蛋白分析,以扫描图面积表示各亚组分构成,观察脂蛋白亚组分变化特点.结果 30例飞行员TRLs清除延迟发生率46.67%.TRLs分子脂蛋白亚组分由极低密度脂蛋白(VLDL)、中密度脂蛋白(IDL)、低密度脂蛋白(LDL)、乳糜微粒(CM)和脂蛋白a[LP(a)]组成.TRLs清除延迟典型扫描图特征为LDL左侧区面积增高,呈双峰或多峰.LDL、VLDL区面积增高,伴有高密度脂蛋白(HDL)面积降低.结论 高三酰甘油血症致动脉粥样硬化作用是在代谢水平异常所致的TRLs清除延迟,TRLs清除延迟是核心环节. 相似文献
67.
健康教育对改善失眠症患者睡眠质量影响的研究 总被引:2,自引:0,他引:2
目的探讨健康教育在改善社区失眠症患者睡眠质量中的作用。方法将在北京某社区卫生服务站就诊的100例失眠症患者随机分为实验组和对照组,每组50例。分别两组患者进行健康教育和常规治疗。健康教育包括改变失眠症患者对睡眠的不正确认识和态度,培养良好的睡眠习惯。6个月后对两组人员进行睡眠状况评价。结果失眠症的发病原因是经济压力、学习工作压力为主。两组患者健康教育后匹兹堡睡眠质量指数各因子分及总分比较有显著性差异(P〈0.05,P〈0.01)。实验组睡眠状况明显改善的为80%,对照组睡眠状况明显改善的为8%,有显著性差异(P〈0.01)。结论健康教育可以改善失眠症患者的睡眠状况,提高睡眠质量。 相似文献
68.
Crystals of L-leucylglycylglycylglycine, LGGG (C12H22N4O5), grown from an ethanol-water solution, are orthorhombic, space groups P212121, with unit cell dimensions (at 22 ± 3°) a = 9.337(1), b = 10.995(1), c = 15.235(1)Å, v = 1563.4 Å3, Z = 4 with a density of Dobs= 1.29 g-cm-3 and Dcalc= 1.279 g°cm-3. The crystal structure was solved by the application of direct methods and refined to an R value of 0.029 for 1018 reflections with I ± 2s?. The molecule exists as a zwitterion in the crystal. The trans peptide backbone takes up a folded conformation at the middle glycylglycyl link accompanied by a significant nonplanarity up to Δω of 8° at the middle peptide and is relatively more extended at the two ends. The molecules are linked together intermolecularly in an infinite sequence of head to tail 1–4′ hydrogen bonds, as is typical of charged peptides. It is interesting to note that while glycylglycylglycine takes up an extended β-sheet conformation, addition of Leu to the N-terminal results in a bent conformation. 相似文献
69.
M. Wiegand A. A. Möller C. J. Lauer S. Stolz W. Schreiber M. Dose J. C. Krieg 《Journal of neurology》1991,238(4):203-208
Summary Nocturnal sleep was studied in 16 inpatients with Huntington's disease. In comparison with healthy controls, patients exhibited a disturbed sleep pattern with increased sleep onset latency, reduced sleep efficiency, frequent nocturnal awakenings, more time spent awake and less slow wave sleep. These abnormalities correlated in part with duration of illness, severity of clinical symptoms, and degree of atrophy of the caudate nucleus. Patients showed an increased density of sleep spindles. 相似文献
70.
Membrane flow within the myelin sheath in IDPN neuropathy 总被引:1,自引:0,他引:1
A. E. BLAUROCK M. B. GENTER ST CLAIR D. G. GRAHAM 《Neuropathology and applied neurobiology》1991,17(4):309-321
This report describes some aspects of beta,beta'-iminodipropionitrile (IDPN) neuropathy in rats as observed by ultrastructural methods and X-ray diffraction. Light microscopy shows gross swelling of the axons in proximal lumbar spinal roots 8 days after intraperitoneal injection of IDPN. Mean axon cross-sectional area and mean axon perimeter increased to 280% and 160% of their control values, respectively. At the same time, myelin membrane packing was not visibly disturbed. In addition, X-ray diffraction patterns, recorded under physiological conditions, demonstrate that the myelin lipid bilayer thickness and widths of the aqueous spaces between bilayers did not change. Related observations are made on posterior tibial nerve (PNS myelin) and ventral spinal cord (CNS myelin). The various observations together are interpreted in terms of a fluid myelin membrane. It is proposed that the myelin membrane flows during axon swelling even though normal membrane-membrane contacts are maintained within the sheath. Membrane flow and slippage between membranes are explained in terms of a molecular model of the myelin multilayer. 相似文献