糖尿病大鼠早期视网膜神经节细胞凋亡机制的探讨

目的：探讨糖尿病大鼠模型早期视网膜神经节细胞(retinal ganglion cells,RGCs)凋亡的机制。

方法：SD大鼠60只,随机分为对照组(CON)及糖尿病组(DM),糖尿病组一次性腹腔注射1% STZ诱发糖尿病鼠模型,两组于第4,8,12wk分别行HE、透射电镜及TUNEL法检测RGCs的凋亡情况,并应用激光共聚焦显微镜检测RGCs内钙离子浓度的变化。

结果：糖尿病组第8wk开始出现RGCs数量减少、细胞排列紊乱的病理改变,第12wk更为明显。糖尿病组透射电镜下可见第4wk时RGCs出现线粒体肿胀; 第8wk时RGCs内肿胀的线粒体更为明显、数目增多,染色质边集于核膜周边,部分细胞体积缩小、细胞器减少; 第12wk时出现RGCs体积变小,甚至出现细胞核断裂。TUNEL阳性RGCs最早于糖尿病组第4wk时出现,随病程延长凋亡的阳性细胞逐渐增多,凋亡指数与同期对照组相比,差异有统计学意义(P<0.01)。糖尿病组第8,12wk时RGCs内钙离子浓度明显高于同期对照组,差异显著(P<0.01); 糖尿病组第8wk与第12wk比较,升高差异亦有统计学意义(P<0.05)。

结论：糖尿病早期出现了视网膜神经节细胞的凋亡,其机制可能与细胞内钙离子浓度升高有关。     

HPLC法测定生物样品中淫羊藿苷的浓度

以苯甲酸为内标，建立了ＨＰＬＣ测定动物血浆，尿，粪及心，肝，脾，肺，肾等组织匀浆中淫羊萑苷的浓度。色谱术五彩 用ＺｏｒｂａｘＯＤＳ，流动相为四氢呋喃一水一冰醋酸（２０：７５：５），紫外检测波长２７０ｎｍ。     

左乙拉西坦引起苯巴比妥血药浓度降低案例分析

目的:探讨左乙拉西坦与苯巴比妥的药物相互作用及作用机制。方法:临床药师通过神经内科ICU的一例伴难以控制、反复发作癫的急性重症脑炎病例用药发现问题,查阅病历资料及相关文献进行分析。结果:左乙拉西坦可引起苯巴比妥血药浓度降低,可能与两者竞争结合P糖蛋白有关。结论:临床药师应该加强对左乙拉西坦的药物相互作用的观察和研究,以促进抗癫药物的合理应用。     

Magnetoacoustic Wave Scattering and Dynamic Stress Concentration around the Elliptical Opening in Exponential-Gradient Piezomagnetic Materials

Based on the theory of magnetoacoustic coupled dynamics, the purpose of this paper is to evaluate the dynamic stress concentration near an elliptical opening in exponential-gradient piezomagnetic materials under the action of antiplane shear waves. By the wave function expansion, the solutions for the acoustic wave fields and magnetic fields can be obtained. Stress analysis is performed by the complex function method and the conformal mapping method, which are used to solve the boundary conditions problem, and is used to express the dynamic stress concentration coefficient (DSCC) theoretically. As cases, numerical results of DSCCs are plotted and discussed with different incident wave numbers and material parameters by numerical simulation. Compared with circular openings, elliptical openings are widely used in material processing techniques and are more difficult to solve. Numerical results show that the dynamic stress concentration coefficient at the elliptical opening is strongly dependent on various parameters, which indicates that the elliptical opening is more likely to cause crack and damage to exponential-gradient piezomagnetic materials.     

大剂量甲氨蝶呤静脉给药时间对淋巴瘤患者脑脊液中药物浓度的影响

背景与目的:甲氨蝶呤(methotrexate,MTX)在脑脊液中高于最小有效治疗浓度是治疗中枢淋巴瘤的必要条件,目前尚不明确大剂量MTX(high doseMTX,HD-MTX)静脉给药时间对MTX穿透血脑屏障的影响.本研究探索HD-MTX静脉不同给药时间对脑脊液中MTX浓度的影响,以获得更好的中枢淋巴瘤防治效果并尽可能减少MTX外周毒性.方法:34例非霍奇金淋巴瘤患者分别接受MTX 1～3g/m2 6 h持续静脉给药或24 h持续静脉给药,其中17例交替使用两种给药方法;采用高效液相色谱法检测MTX停药0 h、24 h、48 h的MTX血清浓度,及停药0 h后脑脊液中MTX浓度;比较两组血中和脑脊液中MTX浓度以及毒性反应,并对影响MTX浓度的因素进行相关分析.结果:给药结束时6 h给药组的MTX血清浓度显著高于24 h给药组:自身对照结果6 h给药组的脑脊液中MTX浓度为0.70 Ixmol/L,明显高于24 h给药组的0.49 Ixmol/L(校正值,P=0.044).MTX的脑脊液浓度与血清浓度呈正相关,中枢侵犯患者脑脊液MTX浓度显著高于无中枢侵犯的患者.自身对照结果6 h组和24 h组Ⅱ～Ⅳ度粘膜炎的发生率分别15.4%和37.8%.Ⅲ～Ⅳ度骨髓抑制的发生率分别为46.2%和67.6%.结论:在提高MTX的中枢浓度和降低外周毒性方面,HD-MTX 6 h给药方案优于24 h给药方案.     

Ionized and total magnesium concentration in patients with severe preeclampsia-eclampsia undergoing magnesium sulfate therapy

AIM: As ionized magnesium is the active form of magnesium and exerts a therapeutic effect, the present study was performed to determine the levels and correlations between ionized and total magnesium under baseline and therapeutic conditions in patients with severe preeclampsia and eclampsia receiving magnesium sulfate. METHODS: Fifty singleton patients with severe preeclampsia received a loading dose of 4 g of magnesium sulfate, followed by 2 g per hour as maintenance dose until 24 h after delivery, or 24 h after the last seizure in case of postpartum convulsions. Serial blood samples were taken before magnesium sulfate infusion, 30 min and 240 min after the initiation of the infusion and 4 h after the discontinuation of the drug. Data were analyzed by repeated measure ANOVA and paired t-test. RESULTS: Baseline levels of total and ionized magnesium were 2.4+/-0.6 mEq/L and 1.3+/-0.5 mEq/L (mean+/-SD), respectively. Putative level of 4 mEq/L of total magnesium was not obtained in up to 42% of patients during the treatment. There was not any significant correlation between the two forms of magnesium under baseline and therapeutic conditions. CONCLUSION: Despite the effectiveness of the standard regimen of magnesium sulfate in the treatment and prevention of eclamptic seizures, it can not provide the proposed therapeutic level of magnesium in all patients. With respect to the lack of correlation between ionized and total magnesium, further studies are necessary to investigate the superiority of measurement of ionized, rather than total magnesium, for titration of therapeutic magnesium sulfate infusion.     

麦滋林-S对氧氟沙星的血浆浓度的影响

目的　因氧氟沙星口服对胃黏膜有刺激作用 ,因此在治疗中往往造成药物性胃炎。本文寻找一种既不影响氧氟沙星疗效 ,又能对抗氧氟沙星破坏胃黏膜作用的理想配伍药物。方法　选择麦滋林 -S(Marzulene -S)及硫糖铝 2种抗溃疡药分别与氧氟沙星配伍使用。结果　麦滋林组的病例与氧氟沙星单独用药组血药浓度相似 (P >0 .0 5 ) ,而硫糖铝组血中氧氟沙星浓度明显低于上述 2组 (P >0 .0 5 )。结论　证明麦滋林 -S颗粒对氧氟沙星血药浓度没有影响 ,且有效保护了胃黏膜免受氧氟沙星的破坏 ;而硫糖铝中所含金属铝离子与喹诺酮类药物形成络合物 ,影响其吸收 ,因而降低了氧氟沙星的疗效     

黄连解毒汤不同剂型抗菌药效实验研究

目的从体外抗菌效果的角度比较黄连解毒汤颗粒剂和黄连解毒汤煎剂两种剂型的药效。方法用试管内药液两倍稀释法分别测定黄连解毒汤颗粒剂和黄连解毒汤煎剂对不同细菌的最小抑菌浓度（MIC）。结果两种剂型对各实验菌的MIC分别为：黄连解毒汤颗粒剂介于0.0020～0.5000g·ml-1;黄连解毒汤煎剂对大肠埃希氏菌不敏感（〉0.50g·ml-1）,对其余实验菌介于0.0078～0.1250g·ml-1。结论黄连解毒汤颗粒剂的抑菌作用优于黄连解毒汤煎剂,可以作为黄连解毒汤煎剂的替代品。     

纯母乳喂养对新生儿血糖浓度的影响

目的:探讨纯母乳喂养对新生儿血糖浓度的影响。方法:将130例自然分娩的健康、足月新生儿随机分为纯母乳喂养组和加配方奶组各65例,纯母乳喂养组按需哺乳,加配方奶组以产妇哺乳为主,每次哺乳后添加牛乳,分别在出生后6h、24h、48h、72h进行动态血糖测定。结果:纯母乳喂养组与加配方奶组出生后6h血糖浓度分别为3.38±0.98mmol/L,3.34±0.96mmol/L;24h血糖浓度分别为3.36±0.88mmol/L,3.37±0.89mmol/L;48h血糖浓度分别为3.33±0.82mmol/L,3.36±0.85mmol/L;72h血糖浓度分别为3.26±0.73mmol/L,3.37±0.82mmol/L;两组4次监测血糖均无显著性差异(P>0.05)。结论:纯母乳喂养对新生儿血糖无明显影响,能满足新生儿生理需要。     

Concentration gradients in evaporating binary droplets probed by spatially resolved Raman and NMR spectroscopy

Understanding the evaporation process of binary sessile droplets is essential for optimizing various technical processes, such as inkjet printing or heat transfer. Liquid mixtures whose evaporation and wetting properties may differ significantly from those of pure liquids are particularly interesting. Concentration gradients may occur in these binary droplets. The challenge is to measure concentration gradients without affecting the evaporation process. Here, spectroscopic methods with spatial resolution can discriminate between the components of a liquid mixture. We show that confocal Raman microscopy and spatially resolved NMR spectroscopy can be used as complementary methods to measure concentration gradients in evaporating 1-butanol/1-hexanol droplets on a hydrophobic surface. Deuterating one of the liquids allows analysis of the local composition through the comparison of the intensities of the C–H and C–D stretching bands in Raman spectra. Thus, a concentration gradient in the evaporating droplet was established. Spatially resolved NMR spectroscopy revealed the composition at different positions of a droplet evaporating in the NMR tube, an environment in which air exchange is less pronounced. While not being perfectly comparable, both methods—confocal Raman and spatially resolved NMR experiments—show the presence of a vertical concentration gradient as 1-butanol/1-hexanol droplets evaporate.

Evaporating droplets occur in various contexts such as inkjet printing (1, 2), heat transfer, or daily phenomena such as drying coffee stains (3, 4). In many applications, such as painting (5), cleaning, gluing, or printing (6), where liquid mixtures are used, the evaporation of a droplet is a complex process because the concentration profile within the droplet varies over time. To improve the controllability and predictability of the technical processes, it is essential to characterize the transport phenomena during the drying process. The measurement of the droplet composition is a crucial element and has to be carried out with sufficient spatial and temporal resolution. In particular, spectroscopic methods are promising tools for contactless concentration measurements of liquid mixtures.The evaporation of a droplet is governed by physical properties such as surface tension (7), density (8–10), vapor pressure (11), and boiling temperature. Additionally, concentration gradients can evolve in liquid mixtures (12). These gradients are driven by thermal gradients due to the enthalpy of evaporation (droplet cooling) or on heated surfaces, by surface tension gradients induced by preferential evaporation of one component or by density gradients for droplets composed of liquids with different densities like water and glycerol (13). The evaporation rates of the components can vary over the droplet surface. For sessile droplets with contact angles smaller than 90°, for example, the evaporation rates are higher at the three-phase contact line (14). These thermal or surface tension gradients can induce flow inside the droplet called Marangoni flow. This flow leads to concentration gradients across the droplet (7–10). The direction of the gradient depends on the density and surface tension. A direct application of this principle is, for instance, Marangoni cleaning in semiconductor technology (15).The investigation of the composition of sessile drops on the microliter scale, as they occur in inkjet printing or other technical processes, poses a challenge because the typical length scales of interest are smaller than the capillary length. In bulk samples, the composition can be examined in a straightforward manner with chromatographic methods such as gas chromatography and high-performance liquid chromatography or spectroscopic methods such as NMR spectroscopy, infrared spectroscopy, and Raman spectroscopy. However, for the investigation of sessile droplets, a high spatial and temporal resolution is required. For this purpose, confocal Raman spectroscopy and spatially resolved NMR spectroscopy are powerful tools. For both techniques, concentration determination is straightforward if at least two signals of the components of interest are baseline-separated. NMR is intrinsically calibration-free, whereas Raman spectroscopy requires calibration through reference experiments (16–18). Both approaches allow the quantification of concentration gradients in sessile droplets, as is shown here.In Raman microscopy, good spatial resolution can be achieved in a confocal setup. The components of mixtures can be distinguished via specific vibrations for different functional groups or through a careful analysis of the Raman signals in the fingerprint region (<1,500 cm⁻¹). For example, binary mixtures of ethanol and water can be characterized in a straightforward manner (17). If, however, both liquids have a similar chemical structure, the discrimination of the components might be hampered by signal overlap in the C–H stretching region (2,800 to 3,000 cm⁻¹); e.g., in such cases, Raman signals in the fingerprint region (<1,500 cm⁻¹) might be used for the identification of the species. However, these signals often provide a poor signal-to-noise ratio, which makes large integration times necessary. Thus, the image rate or resolution is so low that even slow diffusion processes are hardly resolved. Here, Raman stable isotope probing (SIP), which has been developed to monitor metabolic processes in microbiology, offers a solution (19). The basic idea of Raman SIP is to replace the proton in the C–H with deuterium in one of the mixture components such that the C–D stretching region occurs at roughly 1/2 times the C–H stretching and falls into a region with very weak or even without signals from the protonated liquid component. Thus, the concentration in a binary mixture can be calculated in a straightforward manner from the ratio of the integrated Raman intensities ICD/ICH of the respective stretching vibrations.Compared to Raman microscopy, where localization is achieved by scanning the focal point across the region of interest, in NMR experiments localization is achieved by using magnetic field gradients. Usually, one avoids phase boundaries (especially liquid–gas interfaces) in NMR experiments because they disturb the magnetic field homogeneity and reduce the spectral quality in terms of line shape and baseline separation of the resonances. Nevertheless, it has been shown that MRI can be used to characterize freezing water droplets (20), the infiltration of water into asphalts (21), and the evaporation of sessile droplets from porous surfaces (22–24). Additionally, NMR can be used to quantify the composition of binary droplets during evaporation (25).Thus, the use of both complementary approaches to characterize evaporating binary droplets may be beneficial. In this article, we discuss the capabilities of Raman SIP and NMR techniques to analyze the evolution of the composition of an evaporating sessile binary droplet. As a model system, a binary mixture of 1-butanol and 1-hexanol was used. This mixture shows a low volatility such that the evaporation process can be captured with both Raman and NMR spectroscopies. With Raman spectroscopy, it was possible to observe concentration gradients of 1-butan-d₉-ol over the height of the droplet during evaporation. NMR techniques were examined in terms of the capability to observe the evaporation of 1-butanol and yield time-dependent droplet composition with spatially resolved ¹H-NMR spectra. Furthermore, the contours of the evaporating droplets were tracked by optical measurements to characterize the time-dependent changes in the droplet dimensions. Flows induced by the concentration gradients were confirmed by astigmatic particle tracking velocimetry.