高校有机化学开放性实验管理模式研究与探索

高校有机化学开放性实验对于高校学生化学实践能力和化学思维的培养具有积极的影响,高校化学教师要注意结合有机化学的实验要求和高校学生的实际学习需求,科学设计高校有机化学开放性实验管理模式。本篇文章主要对开放性实验的内涵,高校有机化学开放性实验管理的价值以及高校有机化学开放性实验管理的主要模式进行分析,旨在为高校学生营造一个良好的化学学习平台,培养学生的化学实践能力和化学思维。     

控制磷脂代谢对动物心肌细胞膜(膜结合酶)的结构和功能的影响

几年来我国在克山病、大骨节病的研究中,发现病儿心肌、红细胞膜的形态、结构和功能方面存在异常,在以模拟克山病区居民生活特点、控制磷脂和硒的动物模型实验中,出现了类似克山病心肌损伤的一系列病变(如心电图、病理形态、代谢及心肌磷脂组成的改变),表明控制磷脂代谢可以改变某些组织细胞膜的结构和功能,这对研究心血管病等老年性疾病的发生及其防治将有重要意义,即修饰改善活体的细胞膜将是可能的。本文是我们通过一种控制磷脂代谢的基础饲料喂养动物,观察其对心肌细胞膜组分、膜结合酶活性乃至心肌功能的影响的实验结果,同时对补充磷脂的效应进行了平行观察。     

开搏通对游泳大鼠心肌肥大的影响

为了明确开搏通对运动性心肌肥大的作用。本实验采用游泳训练引起的大鼠心肌肥大模型,应用放射免疫及生化等方法对心肌肥大及心脏肾素－血管紧张素系统（Ｒ－Ａ－Ｓ）的变化进行了初步研究。观察到游泳五周时,大鼠心重／体重比值（Ｈ／Ｂｗｔ）显著升高,同时心肌血管紧张素Ⅱ（ＡｎｇⅡ）及心肌血管紧张素转换酶（ＡＣＥ）也明显升高。而服用开搏通的游泳大鼠心肌ＡｎｇⅡ,ＡＣＥ较单纯游泳组低,但心重／体重比值却升高。上述结果提示开搏通能抑制运动所致心肌ＡｎｇⅡ升高,但不能防止运动引起的心肌肥大。     

慢性缺氧时心肌血流量的变化及一氧化氮和内皮素—1的调节作用

近年来国内外研究表明急性缺氧时心肌血流量明显增加 ,而慢性缺氧对心肌血流量的影响及其发生机制 ,目前国内外研究甚少 ,且结果不甚相同 ,因此探讨缺氧时心肌血流量的变化及其发生机制 ,对于评估缺氧时心肌供血状态 ,了解心脏高原适应具有理论和实际意义。因此 ,本文观察了慢性间断缺氧大鼠的心肌血流量、血浆、心肌组织ＮＯ(ｎｉｔｒｉｃｏｘｉｄｅ ,ＮＯ)和ＥＴ 1(ｅｎ ｄｏｔｈｅｌｉｎ 1,ＥＴ 1)的含量 ,以期探讨ＮＯ、ＥＴ 1改变、红细胞增多与心肌血流量变化的关系。1　材料和方法(1)实验动物　健康ｗｉｓｔａｒ成年大鼠 6 9只 ,雌雄…     

一种新的分化心肌细胞筛选策略：稳定表达αMHC-Blar-2A-EGFP-Rex-mCherry-2A-neo融合基因的人胚胎干细胞系的建立及其向心肌细胞定向分化的鉴定

心肌梗死是威胁人类健康的重要疾病之一,胚胎干细胞来源的心肌细胞移植是目前治疗心肌梗死的研究热点. 但是由于受到分化的心肌细胞纯度的影响,限制了心肌分化的机理研究以及临床应用. 本实验构建含有心肌特异性启动子α MHC启动的灭瘟素（Blasticidin,简称Blar）抗性基因及增强绿色荧光蛋白（EGFP）的慢病毒表达载体αMHC-Blar-2A-EGFP-Rex-mCherry-2A-neo. 应用慢病毒转染技术将慢病毒转染到人胚胎干细胞（hESCs）,胚胎干细胞特异性启动子Rex启动mCherry和neo抗性蛋白的表达. 经过G418药物筛选,建立G418和mCherry阳性的细胞系. 通过PCR及流式细胞术,进一步鉴定稳定转染的hESCs细胞系;核型分析表明,该细胞系在建立过程中仍保持细胞核型的稳定. 在诱导稳定转染的hESCs向心肌细胞分化的实验中,分化的心肌细胞表达心肌细胞特异的肌钙蛋白(cTnT),同时具有EGFP和Blasticidin药物筛选的双标记.本实验建立的这一细胞系可用于心肌细胞的纯化,为深入研究心肌发生发育的关键调控机制及临床应用奠定基础.     

运动小鼠心肌和骨骼肌对支链氨基酸的摄取及其对蛋白质 …

目的和方法：本实验采用昆明种小鼠游泳运动模型,及＾１５Ｎ－Ｇｌｙｃｉｎｅ和＾３Ｈ－Ｌｅｕｃｉｎｅ同位素示踪技术探讨了运动状态下心肌和骨骼肌对ＢＣＡＡ的摄取量及ＢＣＡＡ对蛋白质合成的作用。结果：运动时心肌和骨骼肌从血循环中摄取ＢＣＡＡ显著增加,同时血清中ＢＣＡＡ的含量降低,结论：心肌和骨骼的蛋白质代谢存在差异,骨骼肌的蛋白质合成率高于心肌,运动使心肌蛋白代谢加速,补充ＢＣＡＡ降低了运动对心肌蛋白质代     

瞬时受体电位通道与心肌肥大研究进展

瞬时受体电位(transient receptor potential,TRP)通道家族是一类广泛分布于人体各组织和器官的阳离子通道.近年来研究发现,部分表达于心肌细胞的TRP通道亚家族成员在病理性心肌肥大中发挥重要作用,目前关于TRP通道与心肌肥大研究的大量实验结果提示,TRP通道有可能成为干预病理性心肌肥大的重要靶...     

100WCO2激光心肌血管再造术的实验研究

本文给出了利用１００ＷＣＯ２激光心肌血管再造术动物实验研究结果。激光器采用１００ＷＣＯ２激光,经光关节臂传输和会聚,激光孔径０．２５～０．５ｍｍ,孔间距离５ｍｍ,照射时间０．３秒,利用附加“滤波器”激光打孔技术可减轻心脏的热损伤。结果表明,在正常心肌上打孔,孔周２７０μｍ以外的心肌基本上不受损伤;高功率密度的激光束心肌打孔能够改善心肌微循环,可以明显改善打孔区的心肌缺血程度。实验犬术后六个月铸型实验证实了激光孔道仍然存在,术后三年病理切片检查充分说明了激光孔道仍然保持畅通     

缺血后功能低下大鼠心肌钙与水含量的变化及高渗甘露醇的影响

缺血后心室功能减低(myocardial stunning)的发生机制迄今尚不明了。本实验以 Lang-cndorff 法在离体灌流的大鼠心脏,研究了全心缺血20min 及再灌注40min 后心肌 Ca~(2+)、Na~+K~+、Mg~(2+)及 H_2O 含量的变化,以及高渗甘露醇对缺血后功能低下心肌的影响。实验发现:(1)缺血/再灌注后心肌组织中 Ca~(2+),H_2O 的含量与非缺血组相比分别增加42%(P<0.01)及7.6%(P0.05)。(2)于再灌注同时给予12%高渗甘露醇可明显改善缺血后心室功能:再灌注40min 时,心率-左室压乘积恢复达缺血前的85%,而不给甘露醇仅恢复66.3%(p<0.01);高渗甘露醇同时消除了缺血后功能低下心肌中 Ca~(2+)超负荷与心肌水肿,此现象提示缺血/再灌注引起的肌膜非特异性通透性改变,很可能是钙进入细胞内的路径之一。本研究结果表明,心肌 Ca~(2+)超负荷及轻度心肌水肿参与了缺血后心室功能低下,高渗甘露醇在离体大鼠心脏可明显改善缺血后功能低下心肌的功能,此作用至少部分是由于其具有减低心肌钙与水含量的效应。     

有氧运动诱导心肌肥大和心肌细胞增殖的研究进展

适宜的运动负荷可刺激心肌生理性肥大和心肌细胞增殖,但这种内源性生理过程的分子机制知之甚少,因此有氧运动诱导心肌肥大和心肌细胞增殖的研究是目前发育生物学和细胞生物学领域的热点,其具体分子机制以及生理价值具有重要的生物学和医学研究及应用意义。该文综述了近年来有氧运动诱导心肌肥大和心肌细胞增殖的研究进展,旨在为相关领域的研究提供参考。     

Dobutamine stress echocardiography assessment of myocardial contusion due to blunt impact in dogs

We sought to investigate the role of two-dimensional stress echocardiography in the early assessment of myocardial contusion. For this purpose, 12 dogs, weighing 11.36 ± 1.50 kg, were selected and the myocardial contusion was experimentally induced. Two-dimensional dobutamine stress echocardiography (DSE) was used to detect abnormal myocardial motions segments at time phases of baseline and 0.5, 2, 4, and 8 h post-wounding. Finally, the above results were compared with pathological findings. The data show that after the dogs were induced to have severe myocardial contusion, 122 segments were found with abnormal myocardial wall motions at 0.5 h post-wounding, 133 segments at 2 h post-wounding, and 142 segments, each, at 4 h and 8 h post-wounding. The wall motion score (WMS) and wall motion score index (WMSI) increased (P < 0.001) as compared with the pre-impaction values. Considering the left ventricular axis view as the standard section, in the 60 segments examined by echocardiography, 54 segments were found to have wall motion abnormalities. Comparing with the results of pathological TTC staining, the sensitivity and specificity were found to be 100 and 66.6%, respectively. It was, therefore, concluded that two-dimensional DSE was a valuable technique in the early diagnosis of myocardial contusion due to its better sensitivity and specificity.     

A Contusion Model of Severe Spinal Cord Injury in Rats

The translational potential of novel treatments should be investigated in severe spinal cord injury (SCI) contusion models. A detailed methodology is described to obtain a consistent model of severe SCI. Use of a stereotactic frame and computer controlled impactor allows for creation of reproducible injury. Hypothermia and urinary tract infection pose significant challenges in the post-operative period. Careful monitoring of animals with daily weight recording and bladder expression allows for early detection of post-operative complications. The functional results of this contusion model are equivalent to transection models. The contusion model can be utilized to evaluate the efficacy of both neuroprotective and neuroregenerative approaches.     

Human immunodeficiency virus seroconversion presenting with acute inflammatory demyelinating polyneuropathy: a case report

Introduction

Electrocardiogram (ECG) abnormalities in patients with blunt chest trauma are diverse and non-specific, but may be indicative of potentially life-threatening conditions.

Case presentation

We report a rare case of pneumopericardium with extreme ECG abnormalities after blunt chest trauma in a 22-year-old male. The diagnosis was confirmed using computed tomography (CT) scanning. The case is discussed, together with its differential diagnosis and the aetiology of pneumopericardium and tension pneumopericardium.

Conclusion

Pneumopericardium should be distinguished from other pathologies such as myocardial contusion and myocardial infarction because of the possible development of tension pneumopericardium. Early CT scanning is important in the evaluation of blunt chest trauma.     

Central Canal Ependymal Cells Proliferate Extensively in Response to Traumatic Spinal Cord Injury but Not Demyelinating Lesions

The adult mammalian spinal cord has limited regenerative capacity in settings such as spinal cord injury (SCI) and multiple sclerosis (MS). Recent studies have revealed that ependymal cells lining the central canal possess latent neural stem cell potential, undergoing proliferation and multi-lineage differentiation following experimental SCI. To determine whether reactive ependymal cells are a realistic endogenous cell population to target in order to promote spinal cord repair, we assessed the spatiotemporal dynamics of ependymal cell proliferation for up to 35 days in three models of spinal pathologies: contusion SCI using the Infinite Horizon impactor, focal demyelination by intraspinal injection of lysophosphatidylcholine (LPC), and autoimmune-mediated multi-focal demyelination using the active experimental autoimmune encephalomyelitis (EAE) model of MS. Contusion SCI at the T9–10 thoracic level stimulated a robust, long-lasting and long-distance wave of ependymal proliferation that peaked at 3 days in the lesion segment, 14 days in the rostral segment, and was still detectable at the cervical level, where it peaked at 21 days. This proliferative wave was suppressed distal to the contusion. Unlike SCI, neither chemical- nor autoimmune-mediated demyelination triggered ependymal cell proliferation at any time point, despite the occurrence of demyelination (LPC and EAE), remyelination (LPC) and significant locomotor defects (EAE). Thus, traumatic SCI induces widespread and enduring activation of reactive ependymal cells, identifying them as a robust cell population to target for therapeutic manipulation after contusion; conversely, neither demyelination, remyelination nor autoimmunity appears sufficient to trigger proliferation of quiescent ependymal cells in models of MS-like demyelinating diseases.     

Neural Stem Cell Transplantation in Experimental Contusive Model of Spinal Cord Injury

Spinal cord injury is a devastating clinical condition, characterized by a complex of neurological dysfunctions. Animal models of spinal cord injury can be used both to investigate the biological responses to injury and to test potential therapies. Contusion or compression injury delivered to the surgically exposed spinal cord are the most widely used models of the pathology. In this report the experimental contusion is performed by using the Infinite Horizon (IH) Impactor device, which allows the creation of a reproducible injury animal model through definition of specific injury parameters. Stem cell transplantation is commonly considered a potentially useful strategy for curing this debilitating condition. Numerous studies have evaluated the effects of transplanting a variety of stem cells. Here we demonstrate an adapted method for spinal cord injury followed by tail vein injection of cells in CD1 mice. In short, we provide procedures for: i) cell labeling with a vital tracer, ii) pre-operative care of mice, iii) execution of a contusive spinal cord injury, and iv) intravenous administration of post mortem neural precursors. This contusion model can be utilized to evaluate the efficacy and safety of stem cell transplantation in a regenerative medicine approach.     

Real-time quantitative PCR analysis of temporal-spatial alterations in gene expression after spinal cord contusion

Rat spinal cord contusion injury models the histopathology associated with much clinical spinal cord injury (SCI). Studies on altered gene expression after SCI in these models may identify therapeutic targets for reducing secondary injury after the initial trauma and/or enhancing recovery processes. However, complex spatial and temporal alterations after injury could complicate interpretation of changes in gene expression. To test this hypothesis, we selected six genes and studied their temporal and spatial patterns of expression at 1 h, 1, 3 and 7 days after a standardized spinal cord contusion produced by a weight drop device (10 g x 25 mm at T8). Real-time RT-PCR using TaqMan probes was employed to quantify mRNA for proteolipid protein, glyceraldehyde-3-phosphate dehydrogenase, glial fibrillary acidic protein, nestin, and the GluR2 and NR1 subunits of glutamate receptors. We found widely different temporal and spatial patterns of altered gene expression after SCI, including instances of opposing up- and down-regulation at different locations in tissue immediately adjacent to the injury site. We conclude that greater use of the reliable and extremely sensitive technique of quantitative real-time PCR for regional tissue analysis is important for understanding the altered gene expression that occurs after CNS trauma.     

Frontal Lobe Contusion in Mice Chronically Impairs Prefrontal-Dependent Behavior

Traumatic brain injury (TBI) is a major cause of chronic disability in the world. Moderate to severe TBI often results in damage to the frontal lobe region and leads to cognitive, emotional, and social behavioral sequelae that negatively affect quality of life. More specifically, TBI patients often develop persistent deficits in social behavior, anxiety, and executive functions such as attention, mental flexibility, and task switching. These deficits are intrinsically associated with prefrontal cortex (PFC) functionality. Currently, there is a lack of analogous, behaviorally characterized TBI models for investigating frontal lobe injuries despite the prevalence of focal contusions to the frontal lobe in TBI patients. We used the controlled cortical impact (CCI) model in mice to generate a frontal lobe contusion and studied behavioral changes associated with PFC function. We found that unilateral frontal lobe contusion in mice produced long-term impairments to social recognition and reversal learning while having only a minor effect on anxiety and completely sparing rule shifting and hippocampal-dependent behavior.     

Doppler Tissue Energy and Stress Echocardiography in the Diagnosis of Myocardial Contusion in Canines

We sought to evaluate the significance of Doppler tissue energy (DTE) and stressed echocardiography for diagnosing myocardial contusion (MC) in canines. Ten adult healthy dogs were anesthetized (3% pentobarbital sodium/i.v.) and impacted by BIM-II biological impact machine to induce MC. Conventional and stressed echocardiographies were used for segmental abnormal ventricular wall motions; DTE was also used to detect the abnormal ventricular wall motions and areas of injured myocardial fibers after MC, and the results were compared with those of triphenyl tetrazolium chloride (TTC) staining. The data show that both conventional and stressed echocardiographies identified ventricular wall segmental abnormal motions or even aneurysms. These segments were mainly distributed over the front and middle interventricular walls and anterolateral ventricular wall. The ventricular wall motion scoring and wall motion segment index (WMSI) increased remarkably after MC induction. Compared with TTC staining, the conventional echocardiography showed 100% sensitivity and 66.67% specificity, whereas the stressed echocardiography displayed 100% sensitivity and 88.89% specificity. DTE showed both the sensitivity and specificity of 100% for MC diagnosis. Thus, DTE has higher specificity than conventional and stressed echocardiographies. In conclusion, both DTE and stress echocardiography have higher clinical value for MC diagnosis in canines.     

Changes in noradrenaline and histamine in monkey spinal cords traumatised by weight drop, compression and subsequent decompression

Levels of noradrenaline (NA) and histamine (H) in the spinal cord of monkeys at 8, 24 and 48 hr following 200 g/cm contusion injury, 50 g of compression injury at 8 hr and decompression for 16 and 40 hr following 8 hr of compression were studied in the traumatised and in an adjacent non-traumatised segment. The NA level doubled in the traumatised and non-traumatised segments at 8 hr contusion injury followed by a slow decline to control values at 24 and 48 hr of contusion injury. There was no change in NA content of the spinal cord segments at 8 hr of compression injury. Decompression for 16 hr following 8 hr of compression increased NA content of the traumatised segment. H levels decreased in the traumatised and non-traumatised segments at 24 and 48 hr of contusion injury. Compression for 8 hr elevated H in the traumatised and non-traumatised segments. On decompression H level was further increased in the traumatised segment.     

Sex Difference in Contusion of the Medial Femoral Condyle Rim-Association with MRI Occult Meniscal Tears in the ACL Deficient Knee

BackgroundMeniscal tears, specifically lateral meniscal tears, have a larger than expected un-derdiagnosis rate in the presence of an ACL tear. The purpose of our study was to search for an MRI bone contusion pattern associated with MRI occult meniscal tears in patients with an ACL tear, specifically a contusion of the rim of the medial femoral condyle (RMFC). Our hypothesis was that there would be a significant association between RMFC contusions and MRI occult meniscal tears in patients with an ACL tear. We also searched for a difference between sexes with respect to the presence of the RMFC contusion in the setting of an occult meniscal tear. We also categorized the type, size, and location of these occult meniscal tears in the setting of an ACL tear.Methods This was a retrospective study that examined characteristics of occult meniscal tears and their association with a RMFC bone contusion. IRB approval was obtained. The date range of the study was June 2009 through December 2015. 6392 consecutive knee MRI reports in patients with an ACL deficient knee were reviewed. The study group included 22 patients with MRI occult meniscal tears, the control group included 110 patients. Relevant statistical values were calculated.ResultsThe most common type of occult meniscal tears were small radial and small longitudinal tears of the lateral meniscus. Occult meniscal tears were associated with an RMFC contusion in the study group (p=0.0457), particularly in males (p = 0.0003). In males with a torn ACL, the sensitivity of an RMFC contusion for an occult meniscal tear was 80%.ConclusionIn males with an ACL tear, there was a significant association between a contusion of the RMFC and an occult meniscal tear (commonly small radial or small peripheral partial-thickness longitudinal tears). RMFC contusions were reliably identified by radiologists in this study.Level of Evidence: II