王浆酸对辐射危害的辅助保护功能研究

目的研究王浆酸的辐射保护功能。方法以每日37、73、220mg/kg王浆酸灌胃小鼠30d后,给予一次性全身γ射线照射,进行小鼠外周血白细胞计数、小鼠骨髓细胞DNA含量测定、血清溶血素测定试验。结果实验前后各剂量组小鼠体重与对照组相比差异均无统计学意义(P0.05);辐照后对照组白细胞总数明显低于辐照前,辐射损伤模型成立。辐照后第3d各剂量组白细胞总数均高于对照组,低、高剂量组差异有统计学意义(P0.01,P0.05);高剂量组小鼠骨髓细胞DNA含量高于对照组,差异有统计学意义(P0.05),辐照后各剂量组小鼠血清半数溶血值(HC50)均高于对照组,但差异均无统计学意义(P0.05)。结论本实验条件下王浆酸对60 Co-γ诱发的辐射损伤有较好的辅助保护作用。     

Feature Component-Based Extreme Learning Machines for Finger Vein Recognition

This paper proposes an efficient finger vein recognition system, in which a variant of the original ensemble extreme learning machine (ELM) called the feature component-based ELMs (FC-ELMs) designed to utilize the characteristics of the features, is introduced to improve the recognition accuracy and stability and to substantially reduce the number of hidden nodes. For feature extraction, an explicit guided filter is proposed to extract the eight block-based directional features from the high-quality finger vein contours obtained from noisy, non-uniform, low-contrast finger vein images without introducing any segmentation process. An FC-ELMs consist of eight single ELMs, each trained with a block feature with a pre-defined direction to enhance the robustness against variation of the finger vein images, and an output layer to combine the outputs of the eight ELMs. For the structured training of the vein patterns, the FC-ELMs are designed to first train small differences between patterns with the same angle and then to aggregate the differences at the output layer. Each ELM can easily learn lower-complexity patterns with a smaller network and the matching accuracy can also be improved, due to the less complex boundaries required for each ELM. We also designed the ensemble FC-ELMs to provide the matching system with stability. For the dataset considered, the experimental results show that the proposed system is able to generate clearer vein contours and has good matching performance with an accuracy of 99.53 % and speed of 0.87 ms per image.     

A novel reference coordinate system to locate the inferomedial point of the transverse-sigmoid sinus junction

Background

A coordinate system was previously developed to identify landmarks on the skull surface to help locate the transverse-sigmoid sinus junction in order to reduce surgical morbidity in retrosigmoid craniotomy; however, in practice we found that this system has important flaws.

Objective

To develop and evaluate a novel reference coordinate system to precisely locate the inferomedial point of the transverse-sigmoid sinus junction (IMTS) and evaluate the effect of gender and skull side (left or right).

Methods

Forty-two adult skulls (84 sides) were obtained for analyses. The X-axis was defined by point A (where the upper edge of the zygomatic arch joins with the frontal process of the zygomatic bone) and point B (where the upper edge of the zygomatic arch blends posterosuperiorly into the supramastoid crest). The Y-axis was defined by the line perpendicular to the X-axis and extending across the tip of the mastoid. The x and y coordinates of IMTS (IMTS-x and IMTS-y) were measured in this coordinate system.

Results

There were 20 male skulls and 22 female skulls. The mean IMTS-x measurements were significantly higher on the right side compared with the left side in both males and females. For the left skull side, the mean IMTS-y measurements were significantly lower in females compared with males.

Conclusion

This novel reference coordinate system may be a reliable and practical method for identifying the IMTS during retrosigmoid craniotomy. There are significant differences in location of the axes with regard to gender and skull side.     

Targeted Disruption of G0/G1 Switch Gene 2 Enhances Adipose Lipolysis,Alters Hepatic Energy Balance,and Alleviates High-Fat Diet–Induced Liver Steatosis

Recent biochemical and cell-based studies identified G₀/G₁ switch gene 2 (G0S2) as an inhibitor of adipose triglyceride lipase (ATGL), a key mediator of intracellular triacylglycerol (TG) mobilization. Here, we show that upon fasting, G0S2 protein expression exhibits an increase in liver and a decrease in adipose tissue. Global knockout of G0S2 in mice enhanced adipose lipolysis and attenuated gain of body weight and adiposity. More strikingly, G0S2 knockout mice displayed a drastic decrease in hepatic TG content and were resistant to high-fat diet (HFD)-induced liver steatosis, both of which were reproduced by liver-specific G0S2 knockdown. Mice with hepatic G0S2 knockdown also showed increased ketogenesis, accelerated gluconeogenesis, and decelerated glycogenolysis. Conversely, overexpression of G0S2 inhibited fatty acid oxidation in mouse primary hepatocytes and caused sustained steatosis in liver accompanied by deficient TG clearance during the fasting-refeeding transition. In response to HFD, there was a profound increase in hepatic G0S2 expression in the fed state. Global and hepatic ablation of G0S2 both led to improved insulin sensitivity in HFD-fed mice. Our findings implicate a physiological role for G0S2 in the control of adaptive energy response to fasting and as a contributor to obesity-associated liver steatosis.     

Erythromycin pretreatment induces tolerance against focal cerebral ischemia through up-regulation of nNOS but not down-regulation of HIF-1α in rats

The purpose of this study was to determine whether the antibiotic erythromycin induces tolerance against focal cerebral ischemia, and the possible underlying mechanism including the involvement of neuronal nitric oxide synthase (nNOS) and hypoxia-inducible factor-1α (HIF-1α). In rat focal cerebral ischemia models, we found that erythromycin preconditioning could significantly decrease the cerebral infarct volume and brain edema. Meanwhile, the neurological deficits from day 4 through 7 after surgery were also remarkably decreased after erythromycin preconditioning. Moreover, erythromycin preconditioning induced significantly increased nNOS levels and decreased HIF-1α levels in both mRNA and protein expression. This study for the first time indicated that erythromycin preconditioning could induce focal brain ischemic tolerance and attenuate brain injury of subsequent transient focal cerebral ischemia. The potential mechanism may be due to up-regulation of nNOS, but the HIF-1α system was not involved.     

Local inhibition of GABA affects precedence effect in the inferior colliculus

The precedence effect is a prerequisite for faithful sound localization in a complex auditory environment, and is a physiological phenomenon in which the auditory system selectively suppresses the directional information from echoes. Here we investigated how neurons in the inferior colliculus respond to the paired sounds that produce precedence-effect illusions, and whether their firing behavior can be modulated through inhibition with gamma-aminobutyric acid （GABA）. We recorded extracellularly from 36 neurons in rat inferior colliculus under three conditions： no injection, injection with saline, and injection with gamma-aminobutyric acid. The paired sounds that produced precedence effects were two identical 4-ms noise bursts, which were delivered contralaterally or ipsilaterally to the recording site. The normalized neural responses were measured as a function of different inter-stimulus delays and half-maximal interstimulus delays were acquired. Neuronal responses to the lagging sounds were weak when the inter-stimulus delay was short, but increased gradually as the delay was lengthened. Saline injection produced no changes in neural responses, but after local gamma-arninobutyric acid application, responses to the lagging stimulus were suppressed. Application of gamma-aminobutyric acid affected the normalized response to lagging sounds, independently of whether they or the paired sounds were contralateral or ipsilateral to the recording site. These observations suggest that local inhibition by gamma-aminobutyric acid in the rat inferior colliculus shapes the neural responses to lagging sounds, and modulates the precedence effect.     

全喉切除术后咽瘘发生的相关因素分析

目的 分析全喉切除术后并发咽瘘的相关因素,探讨发生咽瘘的原因,并针对原因提出防治措施.方法 回顾性分析首次住院行全喉切除术的1 18例患者的完整临床资料.应用单因素分析性别、年龄、术前营养状况、术前放疗、术前气管切开、颈部淋巴结清扫术、肿瘤部位、临床分期、病理类型及感染等因素与咽瘘发生的关系.结果 1 18例全喉切除术患者中,17例发生咽瘘,发生率为14.4％（17/118）,通过统计学分析结果发现与咽瘘发生相关的因素有：患者术前营养状况、术前放疗、临床分期、感染.结论 全喉切除术后并发咽瘘是最常见并发症之一,发生咽瘘的原因有多重性,避免相关因素,能有效降低咽瘘的发生率,提高患者术后生存质量.     

不同容量局部麻醉药用于超声引导锁骨下臂丛神经阻滞的效果比较

目的比较不同容量罗哌卡因与利多卡因混合液用于超声引导锁骨下臂丛神经阻滞的效果。方法60例择期行上肢手术的患者按随机数字表法分为A、B两组,每组30例,分别应用0．3％罗哌卡因和1％利多卡因混合液20ml和30ml实施超声引导锁骨下臂丛神经阻滞。阻滞完成后每隔5min测定臂丛各分支的感觉阻滞效果,30min后测定臂丛各分支的运动阻滞程度。记录感觉阻滞起效时间、外科麻醉成功率、并发症及麻醉维持时间。结果A、B组的外科麻醉成功率[93．3％（28／30）比96．7％（29／30）,P〉0．05]、感觉阻滞起效时间[10（5）min比5（5）min,P〉0．05]、运动阻滞程度差异无统计学意义,A组的麻醉维持时间比B组短（P〈0．05）。结论0．3％罗哌卡因与1％利多卡因混合液20ml及30ml用于超声引导锁骨下臂丛神经阻滞具有相似的麻醉成功率和起效时间。     

改良单悬吊无注气腔镜手术在双侧甲状腺手术中的应用研究

目的 探讨改良单悬吊无注气腔镜手术在双侧甲状腺手术中的应用价值.方法 将42例行腔镜下双侧甲状腺手术的甲状腺良性病变患者按手术方法分为两组：无注气组15例行改良单悬吊无注气腔镜手术,注气组27例行传统注气腔镜手术.比较两组术中和术后情况.结果 42例手术均在腔镜下完成,无中转开放患者.无注气组中9例完成双侧腺叶次全切除术,5例完成一侧腺叶全切除及一侧腺叶次全切除术,1例完成双侧腺叶全切除术.注气组中17例完成双侧腺叶次全切除术,7例完成一侧腺叶全切除及一侧腺叶次全切除术,3例完成双侧腺叶全切除术.两组手术时间、术中出血量、术后住院时间比较差异无统计学意义（P＞0.05）.无注气组术后并发症发生率明显低于注气组[2/15比51.85％（14/27）],差异有统计学意义（P＜0.05）.结论 改良单悬吊无注气腔镜手术可避免注气手术的相关并发症,手术暴露视野良好,操作简单安全,具有临床推广价值.     

不同筛查方法对粘多糖贮积症的筛查效能分析

目的：探讨不同筛查方法对粘多糖贮积症（MPS）的筛查效能。方法回顾2011年1月至2013年12月于本院儿科及遗传咨询门诊就诊的72例可疑患儿的尿粘多糖筛查结果（本研究遵循的程序符合四川大学华西第二医院人体试验委员会所制定的伦理学标准,得到该委员会批准,并征得受试对象本人的知情同意,与之签署临床研究知情同意书）。同时采用甲苯胺蓝显色实验法及溴化十六烷基三甲胺沉淀实验法对疑似 MP S患儿进行尿液粘多糖筛查。结果显色实验法结果呈阳性患儿为25例,阳性筛查效能为72.22%（13/18）,阴性筛查效能为100%（10/10）;沉淀实验法示36例患儿结果呈阳性,阳性筛查效能为42.86%（6/14）,阴性筛查效能为50%（7/14）。两种方法的阳性和阴性筛查效能比较,差异均有统计学意义（P〈0.05）。结论甲苯胺蓝显色实验法是一种简单、快捷、灵敏的 MPS 筛查方法,值得在广大基层医院推广使用,有利于提高该病检出率。