低剪切应力上调基质细胞衍生因子1受体在动脉粥样硬化斑块中表达

目的观察基质细胞衍生因子1受体CXCR4在低切应力诱导的动脉粥样硬化斑块中的表达，探讨CXCR4在动脉粥样硬化病变中的作用。方法建立颈总动脉套环的局部狭窄动物模型，喂养4周；数值模拟局部狭窄远心端流场以及剪切应力分布；酶法测定血浆中总胆固醇、甘油三酯以及HDL水平；HE染色观察局部狭窄远心端病理学改变，油红O染色观察病变处脂质的蓄积，免疫荧光观察病变处CXCR4的表达。     

剪切应力对家兔血管内膜增生及动脉粥样硬化斑块形成的影响

目的设计局部狭窄而导致血流动力学改变的实验模型,探讨剪切应力对血管内膜增生以及动脉粥样硬化斑块形成的影响。方法兔颈总动脉平直段套环形成狭窄度为40%的局部狭窄,饲以正常饮食4周;数值计算的方法模拟血流流场和剪切应力分布及其特征;HE染色检测颈总动脉病理改变;Verhoeff法染色观察血管弹力纤维分布;油红O染色观察斑块内的脂质沉积;高效液相色谱检测血管壁脂质含量。结果套环形成局部狭窄后,颈总动脉血流流场发生显著的扰动,狭窄远心端有涡流以及二次流形成;狭窄近心端形成局部高剪切应力区域(6Pa),而在远心端形成振荡的低剪切应力区域(0～0.3Pa);HE染色显示颈总动脉狭窄的近心端和远心端均有明显的内膜增生以及动脉粥样硬化斑块形成,近心端比远心端病变更严重,近心端增生内膜厚度为165.6±28.3μm,远心端增生内膜厚度为38.5±12.7μm,并且近心端增生内膜的细胞成分主要为圆形的泡沫细胞而远心端增生内膜的细胞成分主要为梭形平滑肌细胞;Verhoeff染色显示病变处弹力纤维排列紊乱,部分内弹力板断裂;油红O染色发现增生的斑块中有大量的脂质沉积;高效液相色谱检测也表明狭窄近心端胆固醇含量(7.6±2.1mg/g)以及远心端胆固醇含量(5.6±1.8mg/g)较对照侧(1.3±0.5mg/g)明显增加。结论高剪切应力以及低振荡剪切应力均引发动脉粥样硬化病变的形成,但不同的剪切应力对斑块的组成和特性有着不同的作用。     

异常剪切应力上调组织蛋白酶L在动脉粥样硬化斑块中表达

目的观察组织蛋白酶L(Cathepsin L)在异常剪切切应力诱导的动脉粥样硬化斑块中的表达,探讨Cathepsin L在动脉粥样硬化病变中的作用。方法采用套环法建立兔颈总动脉局部狭窄的动物模型,喂养4周;数值模拟法模拟局部狭窄远心端和近心端流场特性以及剪切应力分布;酶法测定血浆中总胆固醇、甘油三酯以及HDL水平;HE染色观察病理学改变;油红O染色观察病变处脂质的蓄积;免疫组织化学法检测Cathepsin L的表达。结果 4周后,兔血脂水平没有明显改变。套环形成局部狭窄后,颈总动脉血流流场发生显著的扰动,狭窄远心端有涡流以及二次流形成;狭窄近心端形成局部高剪切应力区域,而在远心端形成振荡的低剪切应力区域(0～0.3 Pa)。HE染色显示颈总动脉狭窄的近心端和远心端均有明显的内膜增生以及动脉粥样硬化斑块形成,近心端比远心端病变更严重。油红O染色显示有大量的脂质沉积;免疫组织化学染色结果表明病变中有大量的Cathepsin L表达,主要分布于斑块中的巨噬细胞和平滑肌细胞,并且近心端Cathepsin L的表达量明显高于远心端量,而对照侧血管仅有微量的Cathepsin L表达。结论切应力特性调节Cathepsin...     

血管紧张素Ⅱ对载脂蛋白E敲除小鼠主动脉粥样硬化斑块细胞外基质金属蛋白酶诱导因子表达影响

目的探讨血管紧张素Ⅱ对载脂蛋白E敲除小鼠主动脉粥样硬化斑块细胞外基质金属蛋白酶诱导因子表达的影响。方法载脂蛋白E基因敲除小鼠经高脂饮食饲养建立动脉粥样硬化模型,用血管紧张素Ⅱ干预。用免疫组织化学法观察粥样硬化斑块内细胞外基质金属蛋白酶诱导因子表达,用RT-PCR及Western blotting检测主动脉内细胞外基质金属蛋白酶诱导因子表达。结果血管紧张素Ⅱ干预组细胞外基质金属蛋白酶诱导因子在动脉粥样硬化斑块内阳性表达较对照组明显增加;血管紧张素Ⅱ干预组主动脉内细胞外基质金属蛋白酶诱导因子mRNA及蛋白表达较对照组明显增加。结论血管紧张素Ⅱ能诱导主动脉粥样硬化斑块内细胞外基质金属蛋白酶诱导因子的表达。     

不同形态低切应力对小鼠腹主动脉重构及内皮P选择素表达的影响

目的 制备小鼠腹主动脉狭窄的实验模型,探讨短期不同形态的低剪切应力对动脉重建及内皮P选择素表达的影响.方法 24只小鼠随机平均分为3个实验组(1h组、4h组、24h组)和1个正常对照组,实验组用动脉银夹建立腹主动脉局部狭窄模型,彩色多普勒超声检测狭窄近心端和远心端血流动力学参数,计算切应力值;血管标本行HE染色和内皮P选择素免疫组织化学染色,定量分析动脉病理形态学的改变和半定量分析内皮P选择素表达的强度.结果 狭窄动脉近心端和远心端血流分别形成低切应力区和振荡性低切应力涡流区,并且在所有观察点狭窄动脉近心端和远心端血管发生不同程度的动脉重建与内皮P选择素表达,但近心端较远心端更明显(P<0.05).结论 血流动力学改变在较短的时间内可引起动脉重构及内皮P选择素的表达,而且不同形态低切应力导致的病变程度是不同的.     

基质细胞衍生因子1α对氧化型低密度脂蛋白诱导内皮细胞与单核细胞粘附的影响

目的观察基质细胞衍生因子1α对氧化型低密度脂蛋白诱导的单核细胞与内皮细胞粘附的影响。方法逆转录聚合酶链反应法和免疫印迹法分别检测内皮细胞基质细胞衍生因子1αmRNA和蛋白的表达,静态粘附实验观察氧化型低密度脂蛋白和基质细胞衍生因子1α抗体干预对内皮细胞与单核细胞粘附的影响。结果基质细胞衍生因子1α在静息状态下的血管内皮细胞上几乎不表达,随着氧化型低密度脂蛋白浓度增加和处理时间延长,基质细胞衍生因子1α的mRNA和蛋白表达水平均明显上调,25mg/L氧化型低密度脂蛋白处理48h时,基质细胞衍生因子1α表达到达峰值。氧化型低密度脂蛋白浓度为1、5、25及125mg/L时,每个视野粘附的单核细胞数分别为190±15、226±23、280±14、253±8,而正常对照组为104±10,差异有显著性意义(P<0.05)。终浓度为0.01、0.1和1μg/L基质细胞衍生因子1α抗体干预后,粘附的单核细胞数分别为202±17、142±6和115±12,明显低于对照组的279±11(P<0.05)。结论基质细胞衍生因子1α参与了内皮细胞与单核细胞的粘附。     

基质细胞衍生因子1对低密度脂蛋白诱导单核—内皮细胞粘附的影响

目的观察基质细胞衍生因子1对低密度脂蛋白诱导的单核细胞-内皮细胞粘附的调节作用,以进一步探讨基质细胞衍生因子1在动脉粥样硬化中的作用。方法密度梯度离心法分离人低密度脂蛋白;逆转录聚合酶反应检测内皮细胞基质细胞衍生因子1mRNA表达,Westernblot检测基质细胞衍生因子1蛋白质的表达;细胞记数法观察低密度脂蛋白及基质细胞衍生因子1抗体干预对内皮细胞单核细胞粘附的影响。结果对照组几乎没有基质细胞衍生因子mRNA以及蛋白质的表达,随着低密度脂蛋白浓度增加,基质细胞衍生因子1mRNA以及蛋白质的表达水平明显增加。低密度脂蛋白浓度为50mgL、100mgL和150mgL时,每个视野粘附的单核细胞数分别为60±20、97±26和170±32,而正常对照组为20±5,差异有极显著性意义(P<0.01)。终浓度为0.1mgL、0.5mgL和1mgL基质细胞衍生因子1抗体干预后,粘附的单核细胞数分别为113±23、53±21和41±10,均低于低密度脂蛋白对照组的186±31,与低密度脂蛋白对照组差异有显著性意义(P<0.05)。结论低密度脂蛋白促进内皮细胞与单核细胞的粘附,其机制与促进内皮细胞表达基质细胞衍生因子1密切相关。     

基质细胞衍生因子1α与动脉粥样硬化

基质细胞衍生因子1α及其特异受体CXCR4在胚胎发育、肿瘤细胞迁移及介导人类免疫缺陷病毒感染中发挥重要作用，最近发现在动脉粥样硬化斑块中基质细胞衍生因子1α高表达，基质细胞衍生因子1α/CXCR4与动脉粥样硬化的关系已经引起重视，现分别从炎症、血管新生、内膜增生等几个方面加以综述。     

细胞外基质金属蛋白酶诱导因子在动脉粥样硬化发展进程中的相关研究进展

细胞外基质金属蛋白酶诱导因子在多种细胞表达并诱导基质金属蛋白酶产生,近期有较多研究表明,细胞外基质金属蛋白酶诱导因子在动脉粥样硬化相关细胞以及人类动脉粥样斑块内高表达,推测其在动脉粥样硬化的病理生理中可能起到重要的作用。     

晚期氧化蛋白产物通过p38丝裂原活化蛋白激酶通路促进ECV304细胞基质细胞衍生因子1α的表达

目的观察晚期氧化蛋白产物对ECV304细胞基质细胞衍生因子1α表达的影响,并探讨其作用机制。方法牛血清白蛋白与次氯酸钠等量混合体外制备晚期氧化蛋白产物,RT-PCR法检测ECV304细胞基质细胞衍生因子1αmRNA的表达,Western Blotting法测定基质细胞衍生因子1α以及磷酸化p38丝裂原活化蛋白激酶(p-p38MAPK)蛋白水平,以p38MAPK特异性阻断剂SB203580进行阻断实验,酶联免疫吸附法测定上清液中基质细胞衍生因子1α浓度。结果与对照组比较,200μmol/L晚期氧化蛋白产物处理ECV304细胞2h后基质细胞衍生因子1αmRNA及蛋白表达量显著升高(P均0.05);基质细胞衍生因子1αmRNA表达量6h达高峰(P0.01),之后逐渐下降,24h时与对照组比较差异无显著性;随时间的推移基质细胞衍生因子1α蛋白表达量逐渐升高,24h表达量最高(P0.01)。晚期氧化蛋白产物作用15min后p38丝裂原活化蛋白激酶磷酸化水平明显增强(P0.05),不同浓度(0.1μmol/L、1μmol/L、10μmol/L)SB203580降低了晚期氧化蛋白产物刺激下基质细胞衍生因子1α蛋白的表达(分别为618.85±60.12、500.98±69.47和359.97±59.81,P0.05或0.01)。结论晚期氧化蛋白产物可诱导ECV304细胞基质细胞衍生因子1α表达,p38MAPK通路是介导这一作用的重要途径之一。     

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.     

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.     

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.     

Serological survey of HIV and syphilis in pregnant women in Madagascar

Objectives Peripartal transmission of human immunodeficiency virus (HIV) and Treponema pallidum, the causative agent of syphilis, leads to severe consequences for newborns. Preventive measures require awareness of the maternal infection. Although HIV and syphilis testing in Madagascar could be theoretically carried out within the framework of the national pregnancy follow‐up scheme, the required test kits are rarely available at peripheral health centres. In this study, we screened blood samples of pregnant Madagascan women for HIV and syphilis seroprevalence to estimate the demand for systemic screening in pregnancy. Methods Retrospective anonymous serological analysis for HIV and syphilis was performed in plasma samples from 1232 pregnant women that were taken between May and July 2010 in Ambositra, Ifanadiana, Manakara, Mananjary, Moramanga and Tsiroanomandidy (Madagascar) during pregnancy follow‐up. Screening was based on Treponema pallidum haemagglutination tests for syphilis and rapid tests for HIV, with confirmation of positive screening results on line assays. Results Out of 1232 pregnant women, none were seropositive for HIV and 37 (3%) were seropositive for Treponema pallidum. Conclusions Our findings are in line with previous studies that describe considerable syphilis prevalence in the rural Madagascan population. The results suggest a need for screening to prevent peripartal Treponema pallidum transmission, while HIV is still rare. If they are known, Treponema pallidum infections can be easily, safely and inexpensively treated even in pregnancy to reduce the risk of transmission.     

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.     

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.