淫羊藿总黄酮对肾上腺素β_1受体的特异性阻断作用

为探讨淫羊藿总黄酮（ＴＦＥ）对肾上腺素受体的作用，本实验用离体兔心房肌、主动脉及豚鼠气管观察了ＴＦＥ对肾上腺素全体的作用，结果ＴＦＥ（０．１３ｇ／Ｌ）抑制心房肌肌力和频率，并使异丙肾上腺素（ＩＳＯ）对心房肌正性频率作用的量效曲线平行右移，但无钙拮抗作用及Ｍ受体激动效应，且不影响ＩＳＯ对豚鼠气管条的负性肌力作用及去甲肾上腺囊（ＮＥ）对兔主动脉条的收缩作用。提示ＴＦＥ选择性阻断肾上腺素β_１受体。     

乐脂平治疗Ⅱ型糖尿病高脂血症的临床研究

观察了３０例伴有高脂血症的Ⅱ型糖尿病患者用小剂量乐脂平（５００ｍｇ／ｄ）治疗４周后血清脂质、脂蛋白的变化。结果：血总胆固醇、甘油三酯及极低密度脂蛋白—胆固醇水平较治疗前下降，高密度脂蛋白—胆固醇明显升高，血糖、血肌酐及血尿酸无明显变化。服用该药未观察到不良反应，提示乐脂平能较好地改善糖尿病患者的脂代谢紊乱。     

Reperfused myocardial infarctions on T1- and susceptibility-enhanced MRI: Evidence for loss of compartmentalization of contrast media

The purpose of this study was to characterize the contrast caused by a susceptibility MRI contrast agents, on spin echo T₂-weighted imaging of reperfused myocardial infarction. Our interest in this model focused on the expected requirement that such agents be compartmentalized in the tissue to cause signal loss on spin echo images, a condition which may not be present in reperfused infarcted myocardium. Accordingly, nine rats were subjected to 2 h of left coronary artery occlusion followed by 3 ± 0.5 h of reperfusion prior to administration of contrast media. Three sets of MR images were acquired: (a) baseline axial images at the midventricle, both T₁-weighted (TR/TE = 300/20) and T₂-weighted (TR/TE = 1500/60); (b) T₁-weighted images after administering a T₁-enhancing agent, Gd-DTPA-BMA (0.2 mmol/kg), to document that contrast media is delivered to the reperfused infarction; and (c) T₂-weighted images after administering the susceptibility agent, Dy-DTPA-BMA (1.0 mmol/kg). Gadolinium-enhanced T₁ images depicted reperfused infarction as regions with greatly enhanced signal intensity compared with unin-farcted myocardium, indicating that contrast agent was delivered to the infarcted zone. Dysprosium-enhanced T₁ images depicted the injury as a region of persistent signal intensity relative to depletion of signal in normal myocardium, consistent with failure of the contrast agent to cause signal loss. Similar infarction sizes were observed for unenhanced T₂-weighted images (33 ± 5%), gadolinium-enhanced T₁ weighted images (36 ± 5%) and postmortem staining (30 ± 6%); strong correlations (r > 0.9) were noted in comparisons of these data. Dysprosium-enhanced images exhibited a smaller region of differential signal presumed to be infarction (20 ± 5%, P < 0.05) and weak correlations (r < 0.75) with the other measurements. We conclude that the smaller infarction depicted on dysprosium-enhanced images is a subregion of the true infarction in which myocardial necrosis is sufficiently advanced that the agent is homogeneously distributed throughout all tissue compartments, preventing T₂*-dependent phase loss on spin echo images.     

Method for the quantitative assessment of contrast agent uptake in dynamic contrast-enhanced MRI

In previous papers relative signal intensity increase was used as a quantitative assessment parameter for contrast uptake in contrastenhanced MRI. However, relative signal intensity increase does not only reflect contrast uptake but depends also on tissue parameters (native T₁ relaxation time) and sequence parameters (repetition time and flip angle); thus, the contrast uptake cannot be assessed accurately using relative signal intensity increase. Based on an analysis of the contrast behavior of spoiled gradient echo sequences, a method is described in this paper that overcomes the limitations of relative signal intensity increase measurement. A parameter, called “enhancement factor” (EF) is introduced that approximates differential T₁ relaxation rate. The enhancement factor scales linearly with contrast uptake and is independent of tissue and sequence parameters. The additional measurement time involved in determining the enhancement factor is less than 1 min and computation is straightforward. The practicality of the new method was confirmed by phantom measurements using T₁-weighted and proton density-weighted spoiled gradient echo sequences (FLASH-2D). Enhancing tissues were simulated by water phantoms doped with increasing concentrations of Gd-DTPA.     

Magnetic resonance elastography of the lung: technical feasibility.

Magnetic resonance elastography (MRE) is a phase-contrast technique that can spatially map shear stiffness within tissue-like materials. To date, however, MRE of the lung has been too technically challenging-primarily because of signal-to-noise ratio (SNR) limitations and phase instability. We describe an approach in which shear wave propagation is not encoded into the phase of the MR signal of a material, but rather from the signal arising from a polarized noble gas encapsulated within. To determine the feasibility of the approach, three experiments were performed. First, to establish whether shear wave propagation within lung parenchyma can be visualized with phase-contrast MR techniques, MRE was performed on excised porcine lungs inflated with room air. Second, a phantom consisting of open-cell foam filled with thermally polarized (3)He gas was imaged with MRE to determine whether shear wave propagation can be encoded by the gas. Third, preliminary evidence of the feasibility of MRE in vivo was obtained by using a longitudinal driver on the chest of a normal volunteer to generate shear waves in the lung. The results suggest that MRE in combination with hyperpolarized noble gases is potentially useful for noninvasively assessing the regional elastic properties of lung parenchyma, and merits further investigation.     

CT增强扫描患者心理分析与护理

本文对470例行CT增强扫描患者心理进行分析、分型，强调心理护理的重要性，针对不同心理表现在增强扫描过程中采取不同的护理措施，效果很好。     

Hydrophobicity of β-adrenoceptor blocking agents: Study of correlations between retention in reversed-phase HPLC systems and octanol-water partition constants

The capacity factors (k′) of seven β-adrenoceptor blocking agents in six different reversed-phase HPLC systems have been determined. Octanol-aqueous buffer (pH 7.4) partition constants (P) for these blocking agents were also obtained. By using target factor analysis (TFA), good empirical correlations between the log k′ and log P were derived. The resulting hydrophobicity order agrees well with the metabolic elimination pathways of these drugs.     

人胎盘提取组织凝血活酶及其质量评价

利用人胎盘抽提得组织凝血活酶，并对其质量进行了评价，同时初步应用于临床。结果显示：用含表面活性剂的抽提剂粉碎抽提的效果较好，所得组织凝血活酶重复性、灵敏度、稳定性均令人满意；与上海荣盛生物制品厂生产的ＰＴ试剂盒比较相关性好：Ｙ＝２．７５＋０．９０５ｘ，ｒ＝０．９２５３，经相关系数ｔ检验，ｔ＝２６．５４６９，Ｐ＜０．００１，呈直线正相关。临床初步应用显示：肝病及抗凝治疗等病人ＰＴ时间明显延长，９３例正常人ｘ＝１１．３秒，ｓ＝０．９６秒，正常范围９．４２－１３．１８秒。     

全肝MR灌注成像早期监测肝VX2肿瘤经皮酒精注射疗效的实验研究

目的研究全肝MR灌注成像（MRPI）早期监视兔肝VX2瘤经皮酒精注射（PEI）疗效的价值。方法新西兰大白兔10只，经开腹手术于肝内注射VX2肿瘤细胞悬液0．1ml，分别在种瘤后第2、3周进行MRT。WI、T2WI检查监视肿瘤生长情况。在种瘤后第3周时，于CT引导下，于肿瘤一侧的早期强化最明显处注射无水乙醇1.0ml，治疗1周后应用MRPI观察治疗效果。灌注参数包括：对比剂到达时间（T0）和最大上升斜率（ss），应用t检验比较治疗区与肿瘤未治疗区的灌注参数。结果10只兔肿瘤均种植成功，第3周时肿瘤直径（2．6±0．6）cm。治疗过程中3只兔死亡，PEI治疗1周后的治疗区呈无或低度强化。肿瘤未治区与治疗区的11D分别为（16．0±1．2）、（50，8±5．9）S，ss分别为38．9±2．2、6．0±1．2，差异均有统计学意义（t值分别为15．8、-39．6，P值均〈0．05）。常规T1 WI、T2 WI无法清晰显示治疗区与未治疗区的差异。结论全肝MRPI可以较敏感的早期监测PEI疗效，早期强化的消失可作为PEI治疗有效的标志。     

A simple model describes large individual differences in simultaneous colour contrast

We report experimental evidence for substantial individual differences in the susceptibility to simultaneous colour contrast. Interestingly, we found that not only the general amount of colour induction varies across observers, but also the general shape of the curves describing asymmetric matching data. A simple model based on von Kries adaptation and crispening describes the data rather well when we regard its free parameters as observer specific. We argue that the von Kries component reflects the action of a temporal adaptation mechanism, while the crispening component describes the action of the instantaneous, purely spatial mechanism most appropriately labeled simultaneous colour contrast. An interesting consequence of this view is that traditional ideas about the general characteristics of simultaneous contrast must be considered as misleading. According to Kirschmann’s 4th law, for instance, the simultaneous contrast effect should increase with increasing saturation of the surround, but crispening predicts the converse. Based on this reasoning, we offer a plausible explanation for the mixed evidence on the validity of Kirschmann’s 4th law. We also argue that simultaneous contrast, the crispening effect, Meyer’s effect and the gamut expansion effect are just different names for the same basic phenomenon.