A role for glutathione,independent of oxidative stress,in the developmental toxicity of methanol

Oxidative stress and reactive oxygen species (ROS) have been implicated in the teratogenicity of methanol (MeOH) in rodents, both in vivo and in embryo culture. We explored the ROS hypothesis further in vivo in pregnant C57BL/6J mice. Following maternal treatment with a teratogenic dose of MeOH, 4 g/kg via intraperitoneal (ip) injection on gestational day (GD) 12, there was no increase 6 h later in embryonic ROS formation, measured by 2′,7′-dichlorodihydrofluorescin diacetate (DCFH-DA) fluorescence, despite an increase observed with the positive control ethanol (EtOH), nor was there an increase in embryonic oxidatively damaged DNA, quantified as 8-oxo-2′-deoxyguanosine (8-oxodG) formation. MeOH teratogenicity (primarily ophthalmic anomalies, cleft palate) also was not altered by pre- and post-treatment with varying doses of the free radical spin trapping agent alpha-phenyl-N-tert-butylnitrone (PBN). In contrast, pretreatment with l-buthionine-(S,R)-sulfoximine (BSO), an inhibitor of glutathione (GSH) synthesis, depleted maternal hepatic and embryonic GSH, and enhanced some new anomalies (micrognathia, agnathia, short snout, fused digits, cleft lip, low set ears), but not the most common teratogenic effects of MeOH (ophthalmic anomalies, cleft palate) in this strain. These results suggest that ROS did not contribute to the teratogenic effects of MeOH in this in vivo mouse model, in contrast to results in embryo culture from our laboratory, and that the protective effect of GSH in this model may arise from its role as a cofactor for formaldehyde dehydrogenase in the detoxification of formaldehyde.     

Diffusion tensor tractography as a supplementary tool to conventional MRI for evaluating patients with myelopathy

Purpose

The aim of this study was to assess the clinical utility of DTI including apparent diffusion coefficient (ADC), fractional anisotropy (FA), in patients with symptoms of spinal cord myelopathy.

Patients and methods

Fifteen subjects with clinical symptoms of acute (n = 3) or slowly progressive (n = 12) spinal cord myelopathy and 11 healthy volunteers were prospectively selected. They all underwent magnetic resonance imaging of the spine at 3.0 T machine. In addition to conventional MRI, DTI was performed; maps of the apparent diffusion coefficient and of fractional anisotropy were reconstructed. Diffusion tensor tractography was used to visualize the morphological features of normal and impaired white matter at the level of the pathological lesions in the spinal cord. The patients were divided into two groups according to the signal intensity on T2WI (group A with no change in signal intensity and group B with high signal intensity).

Results

There were no statistically significant differences in the apparent diffusion coefficient and fractional anisotropy values between the different spinal cord segments of the normal subjects. All of the patients in group B had increased apparent diffusion coefficient values and decreased fractional anisotropy values at the lesion level compared to the normal controls. However, there were no statistically significant diffusion index differences between group A patients and the normal controls.

Conclusion

Diffusion tensor imaging is a reliable method for the evaluation of the diffusion properties of normal and compressed spinal cords. Furthermore, this technique can be used as an important supplementary tool to conventional MRI for the quantification of fiber damage in spinal cord compression, thus has the potential to be of great utility for treatment planning and follow up.     

Assessment of corticospinal tract (CST) damage in acute stroke patients: Comparison of tract‐specific analysis versus segmentation of a CST template

Purpose:

To compare two techniques to assess corticospinal tract (CST) damage in stroke patients: tract‐specific analysis by probabilistic tractography and segmentation using a CST template.

Materials and Methods:

We extracted fractional anisotropy (FA) values, the FA ratio, and mean diffusivity (MD) in 18 stroke patients and 21 healthy volunteers matched for age and sex. We compared the two methods in order to determine their ability to detect 1) differences between diffusion tensor imaging (DTI) parameters of healthy volunteers and stroke patients, 2) the correlation between DTI parameters and clinical scores, and 3) the correlation between DTI parameters and blood oxygen level‐dependent (BOLD) signals in a fist‐closure task.

Results:

FA values were higher with the tractography approach than with the segmentation method, but differences between the ipsilesional CST and the homologous region in healthy subjects were detected using both methods. In patients, clinical scores were significantly correlated with FA values and FA ratios with both methods. The BOLD signal was positively correlated with FA values for CST with the segmentation but not with the tractography approach.

Conclusion:

CST damage in stroke patients can be assessed by either probabilistic tractography or segmentation of a CST template. Although each method has advantages and limitations, both are sensitive enough to detect differences among stroke patients and identify specific correlations with clinical scores. J. Magn. Reson. Imaging 2013;37:836–845. © 2012 Wiley Periodicals, Inc.     

Assessment of brain maturation in the preterm infants using diffusion tensor imaging (DTI) and enhanced T2 star weighted angiography (ESWAN)

Purpose

To assess the brain maturation of preterm infants using diffusion tensor imaging (DTI) and enhanced T2 star weighted angiography (ESWAN).

Materials and methods

Conventional magnetic resonance imaging (MRI), DTI and ESWAN were performed in 60 preterm infants and 21 term controls. 60 preterm infants were subgrouped to two groups according to the age at imaging: before and at term-equivalent age (TEA). Fractional anisotropy (FA), apparent diffusion coefficient (ADC) map from DTI, T₂* and R₂* maps from ESWAN were post-processed at an off-line workstation. The values of FA, ADC, T₂* and R₂* from the posterior limb of internal capsule (PLIC), frontal white matter (FWM), occipital white matter (OWM) and lentiform nuclei (LN) were determined. These parameters were compared between preterm and term infants. Correlations of DTI and ESWAN parameters with the gestational age, postmenstrual age and postnatal age were analyzed.

Results

ADCs of FWM, OWM and LN, and T₂* values of the PLIC and LN were higher in the preterm infants at TEA compared with the term controls.The correlations were existed between the postmenstrual age and the values of FA, ADC, T₂*, R₂* from the PLIC, values of ADC, T₂*, R₂* from the LN, T₂* value from the OWM. The correlations were also found between the postnatal age and the values of FA, ADC, T₂* from the PLIC, and T₂* value from the LN.

Conclusion

The maturity of preterm brain around TEA was different from that of term controls and appeared to be independent of the prematurity at birth. T₂* was one of valuable indices to evaluate brain maturation in preterm infants.     

Safety assessment of myristic acid as a food ingredient.

Myristic acid is used in the food industry as a flavor ingredient. It is found widely distributed in fats throughout the plant and animal kingdom, including common human foodstuffs, such as nutmeg. Myristic acid (a 14-carbon, straight-chain saturated fatty acid) has been shown to have a low order of acute oral toxicity in rodents. It may be irritating in pure form to skin and eyes under exaggerated exposure conditions, but is not known or predicted to induce sensitization responses. Myristic acid did not induce a mutagenic response in either bacterial or mammalian systems in vitro. Relevant subchronic toxicity data are available on closely related fatty acid analogs. In particular, a NOEL of >6000mg/kg was reported for lauric acid (a 12-carbon, straight-chain saturated fatty acid) following dietary exposure to male rats for 18 weeks and a NOEL of >5000mg/kg was reported for palmitic acid (a 16-carbon, straight-chain saturated fatty acid) following dietary exposure to rats for 150 days. The data and information that are available indicate that at the current level of intake, food flavoring use of myristic acid does not pose a health risk to humans.     

丹麦肌电诱发电位装置电路板的维修

介绍了丹麦肌电诱发电位系统因电路板中集成块损坏引起的故障。     

磁共振DTI技术在评估脑梗死患者运动功能康复治疗效果中的研究

目的探讨磁共振弥散张量成像(DTI)在评估脑梗死患者运动功能康复治疗效果中的应用价值。方法医院36例慢性脑梗死患者运动功能康复治疗前后均行磁共振成像和DTI检查,处理图像数据获得各向异性分数(FA)伪彩图,行双侧皮质脊髓束(CST)重建,对健侧和患侧相关数据进行统计分析。结果本组36例患者中,2级15例,占41.67%;3级21例,占58.33%;将15例2级作为A组,21例3级作为B组;A组康复FA值为(0.612±0.039)显著高于B组;2组康复后均显著下降,与康复前相比,差异显著(P0.05);A组康复后FA值为(0.556±0.064)显著高于B组,具有统计学意义(P0.05);康复前A组FudlMeyer评分为(57.264±5.821)分显著高于B组,康复后A组Fudl-Meyer评分为(85.162±9.861)分显著高于B组,差异显著(P0.05);康复治疗前后CST FA值下降百分数与Fudl-Meyer评分上升百分数呈负相关关系。结论磁共振DTI技术可根据CST受损程度评估肢体运动康复训练效果。     

Terapia de resincronización cardiaca. Indicaciones y contraindicaciones

Progress in medical therapy wouldn’t be possible without the contribution of the scientific community. Several randomized controlled trials have led to our current guidelines. Specifically, COMPANION and CARE-HF trials involved a turning point for cardiac resynchronization therapy, which became well recognized for the treatment of heart failure patients with QRS≥120 ms, ejection fraction≤35%, and sinus rhythm to reduce hospitalizations and all-cause mortality. New indications were then established for atrial fibrillation, pacemaker-dependent, and mildly symptomatic patients, but new challenges should be addressed, namely reducing complication and nonresponder rates. To achieve this, further studies and new implant techniques are under investigation.     

前列地尔联合黄芪治疗糖尿病肾病疗效观察

目的 观察前列地尔联合黄芪治疗糖尿病肾病的临床疗效.方法 55例糖尿病肾病患者随机分为联合治疗组(27例)和对照组(28例),对照组单用前列地尔治疗,联合治疗组在此基础上加用黄芪,各组疗程均为2周,治疗前后检测和比较各种生化指标.结果 联合治疗组的治疗总有效率为81.5%,明显高于对照组71.4%(P<0.05);两组治疗后联合治疗组24 h-UAER和ALB较对照组下降明显(P<0.05).结论 前列地尔联合黄芪治疗治疗糖尿病肾病疗效显著,且无明显不良反应,值得临床推广.     

用循证方法研究喜炎平注射液治疗腹泻的疗效

目的 考察喜炎平注射液治疗腹泻的效果与不良反应发生情况.方法 预先设定好文献评定标准,并根据相关关键词进行文献检索,然后对2000-2009年的喜炎平注射液治疗腹泻的疗效和不良反应相关文献进行汇总,对喜炎平注射液的疗效进行Meta分析.结果 分析表明喜炎平注射液临床应用有效,相对危险度(relative risk,RR)的合并统计量及95 9可信区间为(0.28,0.21到0.38),不良反应情况需要进一步查明.结论 喜炎平注射液能够有效的服务于临床,并可作为有效药物用于治疗小儿腹泻.