The Influence of Thiols on the Pre-irradiation Incubation Effect of Nitroimidazoles in E. Coli Cells

Summary

The increase in the degree of radiosensitization of Escherichia coli cells following prolonged pre-irradiation incubation with nitroimidazoles is not correlated with the loss of intracellular non-protein thiols (NPSH) alone. The rates of reduction of the nitro compounds and the NPSH removal do not show strong dependencies on the lipophilicities of the nitroimidazoles whereas the highly lipophilic compound RGW-609 effects an increase in radiosensitization in a much shorter incubation time than the other nitroimidazoles. Exogenous dithiothreitol (DTT) increased the rate of reduction of misonidazole in the cells but did not alter the fraction converted to the amine. Added DTT (0·15 mmol dm^?3) completely protected against the pre-irradiation incubation effect of misonidazole (2·5 mmol dm^?3) when added at the start of the incubation but only partially protected when added before irradiation. It is suggested that NPSH can intercept metabolite(s) (or their precursors) of nitroimidazoles which can potentiate cell killing by radiation.     

单个椎体压缩骨折：恶性和急性良性压缩骨折MR鉴别诊断

目的通过对31例单个椎体压缩骨折(包括恶性和由于骨质疏松造成的良性急性压缩骨折)的MR征象进行观察统计,鉴别其良恶性。方法31例单发椎体压缩骨折患者,其中恶性压缩骨折16例,良性急性压缩骨折15例。均通过活检及3～6个月随访观察证实。进行MR平扫(T1WI,T2WI)及增强扫描。结果单个椎体的恶性和急性良性压缩骨折的MR鉴别诊断主要通过形态学改变及增强后病变形态(共7个征象)进行分析。(1)急性良性压缩骨折椎体压缩程度大;病变不累及整个椎体;多数病灶沿终板分布,椎体前缘或后缘多正常或略凹陷,椎体后缘骨折可形成骨碎片后突;椎弓根多不受累;很少累及周围软组织;椎体静脉多清晰;典型强化方式为沿终板的带状强化。(2)恶性压缩骨折椎体压缩程度小;病变多侵及整个椎体;压缩后椎体前缘和/或后缘多向外凸;多侵及椎弓根;周围软组织受侵;椎体静脉多受侵显示不清;病灶多呈结节状强化。结论区分良性急性压缩骨折和恶性压缩骨折主要依靠形态学的改变和增强后病灶强化的形态,增强后信号增强程度对鉴别上述两种压缩骨折没有显著作用。     

Measurements of Tumour-cell Radiosensitivity in Vivo Using Lung Macrocolony Assay: Dose-survival Artefact Due to ‘Tail Trapping’

Summary

The split-dose effect for survival of colony-forming units (CFU–S) in mouse bone-marrow increases with increasing total dose. This is compatible with the shape of the survival curve, since detailed measurements at doses lower than 200 rad show the presence of a marked initial slope, followed by a tendency towards an increased sensitivity at higher doses. The magnitude of the increase in the split-dose effect is quantitatively similar to values observed by others at comparable low doses in skin, intestine and lung, as deduced from multifraction experiments. It is concluded that these cells do not differ markedly, as has been generally believed, from many other cell types in the ability to demonstrate split-dose effects, when the doses used in the experiments are strictly comparable.     

慢性大动脉狭窄或闭塞性分水岭脑梗死的CT灌注分析

目的 利用CT灌注技术分析慢性大动脉狭窄或闭塞性分水岭脑梗死的血流灌注特征.资料与方法 搜集具有完整临床资料的单侧慢性大脑中动脉或颈内动脉重度狭窄或闭塞所致分水岭脑梗死12例,均行CT灌注及数字减影血管造影(DSA)检查.结果 分水岭脑梗死的CT灌注特征是脑血容量(CBV)及脑血流量(CBF)降低、平均通过时间(MTT)及峰值时间(TTP)延长;分水岭周围缺血区的CT灌注特征是CBF降低、MTT及TTP延长,CBV无明显变化.结论 在慢性大脑中动脉或颈内动脉重度狭窄或闭塞的基础上所致分水岭脑梗死灶周围往往伴有大面积的慢性低灌注脑缺血区,低灌注是分水岭脑梗死的重要促发因素.     

不同负荷类型运动对大学生足型的影响研究

目的:探讨不同负荷类型运动对大学生足型的影响.方法:选取26名正常足型男性大学生,研究相同时间下跑、行走、自然站立后足型和肌电值(electromyography,EMG)的变化.采用双因素重复测量方差分析比较自变量(运动负荷类型×运动前后)对各因变参数(足长、足宽、足围度、内侧纵弓高度、足背高度、足舟骨高度、足弓指数...     

Influence of Calcium on Choline Measurements by 1H MR Spectroscopy of Thigh Muscles

Objective

To study the effects of calcium on the choline peak measurements with 1H MR spectroscopy.

Material and methods

The thigh muscles of two cadaveric specimens were prospectively evaluated on a 3 T MR unit before and after the injection of calcium carbonate (up to 0.4322 g). The choline peaks of 147 spectra from 10 different anatomic locations were quantitatively evaluated. The influence of the calcium concentration and its disposition with respect to the main magnetic field were considered. B₀ phase maps were used to evaluate field inhomogeneities.

Results

The presence of calcium led to a 43 % underestimation of the choline peak and the choline concentration (p?=?0.0002 and 0.0036). The mean choline concentrations before and after CaCO3 injection were 3.53?±?1.72 mmol/l and 1.58?±?0.63 mmol/l. The influence of calcium carbonate on the choline peak estimations was proportional to the calcium concentration. There was a significant position-dependent difference in the estimation of the choline peak amplitude (p?<?0.0154). Calcium injection led to a measurable increase in field inhomogeneities.

Conclusion

There was a significant underestimation of the choline peak amplitude and concentration in the presence of calcium, which might cause misinterpretations of MR spectra.

Key Points

? The presence of calcium led to significant underestimation of choline measurements. ? The influence of calcium is dependent on its concentration and distribution. ? Quantitative MR spectroscopy of calcified tumours should be interpreted with caution.     

Proton Pump Inhibitor Use Is Associated with an Increased Frequency of New or Worsening Hepatic Encephalopathy after Transjugular Intrahepatic Portosystemic Shunt Creation

Purpose

To determine whether proton pump inhibitor (PPI) use increases the rate of new or worsening hepatic encephalopathy (HE) after transjugular intrahepatic portosystemic shunt (TIPS) creation.

优质护理用于肝硬化腹水的临床效果观察

目的探讨优质护理用于肝硬化腹水患者的临床效果。方法我院收治的肝硬化腹水患者150例，随机分为对照组和观察组，对照组给予常规护理，观察组给予心理护理、饮食指导、健康教育等全方位的优质护理，患者出院前对两组患者临床疗效及护理满意程度进行评价。结果观察组总有效率为89．33％，死亡I例（I．33％），对照组总有效率为77．33％，死亡3例（4．00％），两组比较具有显著性差异，观察组患者的有效率及对护理的满意度明显好于对照组。结论优质护理用于肝硬化腹水患者，能够增加患者的生存时间和提高生存质量。     

声预处理对强噪声引起听力损伤保护作用的研究(英文)

目的 探讨低频声预处理对强噪声及中频强噪声引起听力损伤的保护作用。方法 两组声预处理组豚鼠在中心频率０．５ｋＨｚ８５ｄＢ倍频带噪声作用下,连续暴露４ｄ（６ｈ／ｄ）后,在无噪声情况下恢复３ｄ。随后分别在中心频率０．５ｋＨｚ和１ｋＨｚ１１０ｄＢ的倍频带噪声下,暴露１ｈ。两组对照组豚鼠不经声预处理,分别直接暴露在中心频率０．５ＫＨｚ和１ｋＨｚ１１０ｄＢ的倍频带噪声下,暴露１ｈ。两组对照组豚鼠不经声预处理     

单侧颈内动脉狭窄或闭塞后侧支循环与脑缺血关系的研究

目的 探讨单侧颈内动脉狭窄或闭塞后侧支循环与脑缺血的关系.方法 对比分析68例单侧颈内动脉狭窄或闭塞患者(实验组)及20例脑血管DSA检查正常者(对照组)的临床资料及数字减影血管造影(DSA)表现.结果 (1)实验组68例中,狭窄或闭塞发生于颈内动脉41例、大脑中动脉17例、大脑前动脉A1段4例、大脑前动脉A1段以远6例.发现侧支循环开放代偿共109例次,其中前交通动脉32例次、后交通动脉22例次、后软脑膜吻合27例次、前软脑膜吻合19例次、眼动脉4例次、穿支动脉2例次、其他3例次.重度狭窄组与闭塞组侧支循环开放率较高,分别为72.7％、86.7％,与正常对照组差异有显著性(x2=14.029、25.301,P均＜0.001);轻、中度狭窄组侧支循环开放率较低,分别为为16.7％、20.0％,与正常对照组差异无显著性(P=0.676、P=0.551).(2)初级侧支循环开放的比例:症状组小于无症状组,差异有显著性(P=0.042);次级侧支循环开放的比例:症状组大于无症状组,差异有显著性(P =0.022).前交通动脉开放的比例:症状组小于无症状组,差异有显著性(P=0.038);后交通动脉开放的比例:症状组与无症状组无显著性差异(P=0.382).(3)Willis前环变异:症状组最高,其次为正常对照组,而无症状组变异率最低,三组间差异有显著性(P =0.032);Willis后环变异比例:三组间差异无显著性(P=0.110).(4)颈内动脉闭塞的26例,侧支血流评分:梗死组得分最低为(2.4286±0.17271)分,其次为TIA组(3.2500 ±0.2500)分,最高的为无症状组(3.7500±0.16366)分,三组间差异有显著性(F=13.903,P＜0.001).结论 DSA对侧支循环状况的分析、评估具有非常重要的价值,能为颈内动脉狭窄或闭塞的诊断、治疗、预后提供较全面的评价.     

Microwave Ablation in Porcine Livers Applying 5-minute Protocols: Influence of Deployed Energy on Extent and Shape of Coagulation

PurposeTo evaluate the influence of deployed energy on extent and shape of microwave (MW)-induced coagulation in porcine livers applying 5-minute protocols.Materials and MethodsMW ablations (n = 25) were performed in ex vivo porcine livers (n = 8). Ablation time was 5 minutes. Five study groups were defined, each with different power output: I, 20 W (n = 5); II, 40 W (n = 5); III, 60 W (n = 5); IV, 80 W (n = 5); and V, 105 W (n = 5). Extent and shape of white coagulation was evaluated macroscopically, including short diameter, volume, front margin, coagulation center (distance between center of short diameter of coagulation and applicator tip), and ellipticity index (short diameter/long diameter). Deployed energy was also analyzed.ResultsShort diameter and volume were significantly different (P<.001 and P<.001) between the groups: I, 23.0 mm and 11.1 cm³; II, 12.4 mm and 12.4 cm³; III, 27.0 mm and 17.6 cm³; IV, 31.0 mm and 29.2 cm³; and V, 35.0 mm and 42.3 cm³. Front margin and coagulation center were also significantly different (P<.05 and P<.001): I, 6.0 mm and 13.0 mm; II, 8.0 mm and 11.0 mm; III, 8.0 mm and 14.0 mm; IV, 8.0 mm and 18.0 mm; and V, 10.0 mm and 19.0 mm. Ellipticity index was not significantly different. Deployed energy was significantly different (P<.001): I, 5.7 kJ; II, 11.0 kJ; III, 15.5 kJ; IV, 21.6 kJ; and V, 26.6 kJ.ConclusionsExtent, but not shape, of MW-induced coagulation depends on the deployed energy. Applying the protocols described in this study, significantly different coagulation volumes can be created with an ablation time of 5 minutes but different power output.