微小RNA与缺血性脑血管病

微小RNA(microRNA,miRNA)是一类高度保守的非编码小RNA,在转录后水平对基因表达进行负向调控,可导致翻译抑制或mRNA降解.miRNA在进化上高度保守,广泛参与生物体的生长、发育、凋亡等生理或病理学过程.最近的研究表明,特定miRNA在缺血性脑血管病的发生和发展过程中发挥着重要作用,同时还参与了脑缺血后的损伤机制以及保护和修复机制的调控.充分认识各种miRNA的功能意义及其表达水平改变所起的调节作用,不仅有助于明确治疗靶点,阻止神经元死亡,减轻缺血性脑损伤,而且还能通过其表达水平的调控清除凋亡细胞,促进血管发生和神经发生.此外,miRNA也可能为缺血性卒中的预防和诊断提供新的策略.     

微小RNA与缺血性心脏病的发生及治疗

微小RNA(miRNA)是近年来发现的一类长约22个核苷酸的内源性非编码RNA,通过与靶基因mRNA互补配对,介导转录后基因调控,在细胞的分化、增生、凋亡、个体发育以及机体代谢中都具有重要作用。新近研究发现,miRNA在缺血性心脏病形成过程中起着重要的基因调控作用:miR-29在心肌梗死后作为心肌纤维化的调节因素;miR-1与心肌纤维化有关,在心肌梗死后更易致心律失常;miR-21在血管成形术后再狭窄中起着重要作用;miR-126能增强血管生成作用;miR-133能刺激心肌的形成等等。因此,miRNA作为缺血性心脏病的检测指标和治疗工具也越来越受到关注,并可能成为治疗的新靶点。     

微小RNA-27与心血管疾病

微小RNA(miRNA)对心血管疾病的发生发展起重要的调控作用。miR-27可以通过调节多种靶基因的表达直接或间接作用于心血管疾病的发生发展过程,该文就miR-27在心血管疾病中的调控作用机制作一综述。     

微小RNA与卒中

微小RNA(microRNA,miRNA)是由18 ～ 25个核苷酸组成的内源性非编码RNA,可通过完全或部分结合到靶基因mRNA互补序列并使之降解或阻止其翻译而发挥基因调控作用.miRNA在缺血性卒中的发病和病理生理学过程中发挥重要作用.文章对miRNA在缺血性卒中病因学和卒中后病理生理学机制中的作用进行了综述,并对...     

射频消融术改变心房颤动患者外周血微小RNA表达谱

目的探讨心房颤动(房颤)射频消融术是否通过对调控离子通道蛋白的微小RNA(microRNA,miRNA)的影响,实现心房离子流再平衡和逆重构,并试图发现有价值的调控miRNA。方法选择行房颤射频消融术患者(阵发性、持续性和永久性房颤各10例)30例作为房颤组,健康体检者10例作为正常对照组。正常对照组体检时,房颤组射频消融术前和术后3个月分别取外周血,使用miRNA芯片(miRNA v18.0)进行全基因组miRNA表达谱微阵列分析,2组miRNA表达比值≥1.5倍为显著上调,实时定量PCR验证miRNA表达差异结果,并通过mirbase、miranda、targetscan数据库进行靶基因分析。结果与正常对照组比较,房颤组射频消融术前主要参与离子通道蛋白调控的21个miRNA差异表达均有显著意义(P<0.01);房颤组术后3个月与自身术前比较,上述21个miRNA表达亦有明显差异(P<0.01)。其中miR-1266等5个miRNA术前表达上调≥1.5倍,术后明显下调≥10倍;仅miR-3664-5p术前下调8.88倍,术后进一步下降46.06倍;其余15个miRNA均术前表达下调,术后显著上调。结论房颤射频消融术通过影响调控离子通道蛋白的主要miRNA,实现了心房离子流逆重构。调控多个离子流的miR-1266,miR-377-5p,miR-101-5p和miR-151-3p有望成为房颤治疗新靶点。     

循环miR-208在心血管疾病中的价值探索作者：张一凡 审阅：谢莲娜 司瑞 郭文怡

微小RNA(microRNA,miRNA)作为微型调节分子,在转录水平调控蛋白质的表达,进而参与几乎所有生命体的生理和病理过程。近年来发现细胞可通过分泌形式使miRNA进入外周血并在外周血中稳定存在,因而使其具有潜在的诊断疾病的意义。具有心脏特异性的miRNA(miR-208a,miR-208b)是否在急性心肌梗死(acute myocardial infarction)患者的早期外周血中就有升高及这种升高是否具有诊断意义,现就这一研究进展做如下综述。     

微小RNA:缺血性卒中的治疗靶点

微小RNA(microRNA,miRNA)是一类长度为21～25nt的非编码小RNA,可与其靶基因的3’端非编码区互补结合,直接降解靶基因或抑制其编码蛋白质的翻译,广泛参与发育、代谢、凋亡以及多种疾病过程.研究表明,miRNA在缺血性卒中的发生和发展过程中发挥着重要作用,并参与了卒中后的保护和修复机制的调控.     

MicroRNA及其与心律失常关系的研究进展

MicroRNA(miRNA)是一类调节基因,是内源性非编码、长度为18~22个核苷酸的小分子RNA,在转录后水平调节基因表达发挥重要的生物学作用。近期研究表明,miRNA表达水平的变化与心律失常密切相关,诸如miR-1、miR-133、miR-328、miR-208、miR-21及miR-15等可通过细胞膜离子通道的功能和异常表达引发心律失常,干预和调控miRNA的表达水平,有望为心律失常的诊疗提供一个新靶点。     

微小RNA与卒中

微小RNA（microRNA,miRNA）是由18～25个核苷酸组成的内源性非编码RNA,可通过完全或部分结合到靶基因mRNA互补序列并使之降解或阻止其翻译而发挥基因调控作用。miRNA在缺血性卒中的发病和病理生理学过程中发挥重要作用。文章对miRNA在缺血性卒中病因学和卒中后病理生理学机制中的作用进行了综述,并对miRNA的应用前景进行了展望。     

MicroRNA对成骨细胞分化的调控

微小RNA(micro RNA,miRNA)是一类非蛋白质编码调控小RNA,长度约为22nt。由于miRNA不编码蛋白质,限制了其生物学功能的应用。目前的研究主要是关于miRNA调控单一组织的限制性转录,即一类编码一种转录因子,控制影响细胞增殖、分化、凋亡及个体生长发育,miRNA能对成骨分化过程产生正向、负向调控作用。本文就miRNA对成骨细胞分化的调控研究进展进行综述。     

Three layer functional model and energy exchange concept of aging process

Relying on a certain degree of abstraction, we can propose that no particular distinction exists between animate or living matter and inanimate matter. While focusing attention on some specifics, the dividing line between the two can be drawn. The most apparent distinction is in the level of structural and functional organization with the dissimilar streams of ‘energy flow’ between the observed entity and the surrounding environment. In essence, living matter is created from inanimate matter which is organized to contain internal intense energy processes and maintain lower intensity energy exchange processes with the environment. Taking internal and external energy processes into account, we contend in this paper that living matter can be referred to as matter of dissipative structure, with this structure assumed to be a common quality of all living creatures and living matter in general. Interruption of internal energy conversion processes and terminating the controlled energy exchange with the environment leads to degeneration of dissipative structure and reduction of the same to inanimate matter, (gas, liquid and/or solid inanimate substances), and ultimately what can be called ‘death.’ This concept of what we call dissipative nature can be extended from living organisms to social groups of animals, to mankind. An analogy based on the organization of matter provides a basis for a functional model of living entities. The models relies on the parallels among the three central structures of any cell (nucleus, cytoplasm and outer membrane) and the human body (central organs, body fluids along with the connective tissues, and external skin integument). This three-part structural organization may be observed almost universally in nature. It can be observed from the atomic structure to the planetary and intergalactic organizations. This similarity is corroborated by the membrane theory applied to living organisms. According to the energy nature of living matter and the proposed functional model, the decreased integrity of a human body's external envelope membrane is a first cause of the structural degradation and aging of the entire organism. The aging process than progresses externally to internally, as in single cell organisms, suggesting that much of the efforts towards the restoration and maintenance of the mechanisms responsible for structural development should be focused accordingly, on the membrane, i.e., the skin. Numerous reports indicate that all parts of the human body, like: bones, blood with blood vessels, muscles, skin, and so on, have some ability for restoration. Therefore, actual revival of not only aging tissue of the human body's membrane, but the entire human body enclosed within, with all internal organs, might be expected. We assess several aging theories within the context of our model and provide suggestions on how to activate the body's own anti-aging mechanisms and increase longevity. This paper presents some analogies and some distinctions that exist between the living dissipative structure matter and inanimate matter, discusses the aging process and proposes certain aging reversal solutions.     

Unusual responses of nocturnal pineal melatonin synthesis and secretion to swimming: Attempts to define mechanisms

Abstract: The effect of swimming at night on rat pineal melatonin synthesis was compared with that of light exposure at night. Rats were forced to swim at 0030 hr (lights out at 2000 hr) and sacrificed by decapitation 15 and 30 min later, immediately after swimming. Other groups of animals were exposed to white light (650μW/cm²) for 15 and 30 min at same time. Swimming caused a rapid and highly significant drop in the melatonin content in the pineal gland; however, the activity of N-acetyltransferase (NAT), the supposed rate limiting enzyme in the melatonin production, was not changed. Despite the drop in pineal melatonin levels, serum concentrations of the indole remained elevated in the rats that swam. In contrast, melatonin levels in the pineal and serum of light exposed rats fell precipitously, accompanied by a significant suppression of NAT activity. Since we anticipated that the strenuous exercise associated with swimming may induce release of artrial natriuretic peptide (ANP) from the heart, which in turn could cause the release of pineal melatonin, in a second study we injected physiological saline intravenously to stretch the cardiac muscle and release ANP. Three milliliters of normal saline was injected during the day into the jugular vein of anesthetized rats that were pretreated with isoproterenol to stimulate pineal melatonin production. Animals were killed 15 min after the saline injection, and pineal NAT activity and pineal melatonin levels were measured. The saline injections caused no alteration in the elevated levels of either NAT or melatonin. These data suggest that the disparity in pineal NAT activity (which was high) and pineal melatonin (which was low), in animals swum at night, may not be caused by ANP which is released during strenuous exercise such as swimming.     

The immunoneuroendocrine role of melatonin

Abstract: A tight, physiological link between the pineal gland and the immune system is emerging from a series of experimental studies. This link might reflect the evolutionary connection between self-recognition and reproduction. Pinealectomy or other experimental methods which inhibit melatonin synthesis and secretion induce a state of immunodepression which is counteracted by melatonin. In general, melatonin seems to have an immunoenhancing effect that is particularly apparent in immunodepressive states. The negative effect of acute stress or immunosuppressive pharmacological treatments on various immune parameters are counteracted by melatonin. It seems important to note that one of the main targets of melatonin is the thymus, i.e., the central organ of the immune system. The clinical use of melatonin as an immunotherapeutic agent seems promising in primary and secondary immunodeficiencies as well as in cancer immunotherapy. The immunoenhancing action of melatonin seems to be mediated by T-helper cell-derived opioid peptides as well as by lymphokines and, perhaps, by pituitary hormones. Melatonin-induced-immuno-opioids (MHO) and lymphokines imply the presence of specific binding sites or melatonin receptors on cells of the immune system. On the other hand, lymphokines such as -γ-interferon and interleukin-2 as well as thymic hormones can modulate the synthesis of melatonin in the pineal gland. The pineal gland might thus be viewed as the crux of a sophisticated immunoneuroendocrine network which functions as an unconscious, diffuse sensory organ.     

Melatonin and photoperiodic time measurement: Seasonal breeding in the sheep

Abstract: Well-established circadian physiology supports the view that photoperiodic time measurement utilizes the coincidence between the presence of light and a photosensitive phase of a 'biological clock' to alter reproductive status—the so-called external coincidence model of seasonal breeding. In this review, we examine the mechanism whereby photoperiod interacts with presumed suprachiasmatic nuclei activity to allow endogenous melatonin to normally synchronize reproductive activity to the optimal time of year. The Romney Marsh sheep is particularly explored as an experimental model. It is suggested that the on/off activity of seasonal reproduction may be a robust mechanism able to be predictably manipulated by the judicious use of the light/dark cycle and exogenous melatonin, but firmly based on circadian principles.     

Response of rat pineal melatonin to calcium, magnesium, and lithium is circadian stage dependent

Abstract: Herein we documented the response of pineal melatonin production to electrolytes known to be effective on pineal function in view of a possible circadian stage dependence. We studied the release of melatonin by perifused rat pineal glands at 2 different circadian stages corresponding to the middle of the light and dark periods, i.e., respectively, 7 and 19 HALO (Hours After Light Onset, L:D = 12:12). The initial efflux rates were, as expected, much higher in the perifusates of glands removed from rats sacrificed during the dark phase than of those removed during the light phase. After 3 hr of perifusion, melatonin release reached similar levels which were found constant up to the 8th hr of perifusion, whatever the circadian stage. Perifusion of the glands with physiological concentrations for the rat of calcium (5.2 mmol/1) and magnesium (1.34 mmol/1) resulted in a stimulatory effect on the pineal glands removed from rats sacrificed in the middle of the dark period (19 HALO), whereas no effects were observed on the pineal glands removed from rats sacrificed during the light (7 HALO). Lithium (0.28 and 0.55 mmol/1) was ineffective on melatonin release in pineal glands removed 7 and 19 HALO. Our results show differences in the initial efflux rates of melatonin and in the response of perifused pineal glands to calcium and magnesium according to the circadian stage.     

Changes in connexin43, the gap junction protein of astrocytes, during development of the rat pineal gland

Abstract: The abundance of gap junctions between rat pineal astrocytes formed by connexin43 (Cx43) was studied during development. Levels and distribution of Cx43 were measured by immunoblotting and indirect immunofluorescence, respectively. The amount of Cx43 in cells located within the gland was low until about the 7th postnatal day and increased to adult values between the 14th and 21st days postpartum. Although astrocytes, recognized by their vimentin immunoreactivity, were scarce before birth, they were abundant by the 7th postnatal day suggesting that the low levels of Cx43 found at this age corresponded to a low expression of this protein. Localization of the immunoreactivity to Cx43 and vimentin showed a close correlation, indicating that mature or immature pineal astrocytes form gap junctions made of Cx43. Since Cx43 levels attained their adult values at about the time the innervation and the functional state of the gland reached maturity (2–3 weeks after birth), it is proposed that astrocyte gap junctions are involved in the function of the adult rat pineal gland.     

Conservative management of perforated duodenal diverticulum： A case report and review of the literature

Duodenal diverticula are a relatively common condition. They are asymptomatic, unless they become complicated, with perforation being the rarest but most severe complication. Surgical treatment is the most frequently performed approach. We report the case of a patient with a perforated duodenal diverticulum, which was diagnosed early and treated conservatively with antibiotics and percutaneous drainage of secondary retroperitoneal abscesses. We suggest this method could be an acceptable option for the management of similar cases, provided that the patient is in good general condition and without septic signs.     

Language of CTO interventions – Focus on hardware

The knowledge of variety of chronic total occlusion (CTO) hardware and the ability to use them represents the key to success of any CTO interventions. However, the multiplicity of CTO hardware and their physical character and the terminology used by experts create confusion in the mind of an average interventional cardiologist, particularly a beginner in this field. This knowledge is available but is scattered. We aim to classify and compare the currently used devices based on their properties focusing on how physical character of each device can be utilized in a specific situation, thus clarifying and simplifying the technical discourse.