椎间盘退行性变过程中细胞类型及病理生理变化的研究进展

腰背痛为常见病,50％ ～ 80％的成年人在一生中出现过腰背痛症状,严重影响患者生活[1].椎间盘退行性变(IDD)是导致椎间盘源性腰痛的重要原因之一.IDD是指在年龄增长过程中,椎间盘内的髓核组织水分逐渐减少,椎间盘失去正常的弹性和张力,在外界因素(如损伤,劳累等)的作用下,纤维环结构破坏,髓核组织结构发生异常改变.IDD是一个慢性炎性状态,发生退行性变的椎间盘中炎性因子显著升高,基质降解酶活性增高,血管神经长入发生退行性变的椎间盘[2].更重要的是椎间盘基质中的炎性因子吸引炎性相关细胞进入发生退行性变的椎间盘,炎性细胞又刺激椎间盘细胞产生更多的促炎细胞因子,加速IDD的发展.     

腰椎椎间盘退行性变大动物模型的建立方法

<正>椎间盘退行性变(IDD)是脊柱外科的常见病和多发病,随着人口老龄化进程的加速,其发生率大幅上升~([1-2])。IDD是引起腰背痛的主要原因~([3-4]),为了寻求治疗腰背痛的有效手段,IDD与椎间盘再生的基础研究近年来受到了广泛关注。由于穿刺或者椎间盘造影会破坏椎间盘完整性,加速退行性变,在人体上进行的椎间盘研究只能进行观察而不能开展直接干预的有创研究,而动物模型在许多方面可以模拟人体IDD的发生过程,从而可     

椎间盘退变易感基因研究进展

目前研究认为,椎间盘退行性变(IDD)是环境因素和遗传因素共同作用的结果.遗传因素涉及体内广泛存在的IDD易感基因,大致包括椎间盘结构相关基因、骨质疏松相关基因、代谢相关基因、细胞因子相关基因、疼痛信号通路相关基因等.基因突变及多态性与IDD具有相关性,某些基因存有一定的种族差异.近年研究表明,目的基因转染退变椎间盘纤维环及髓核等可延缓,甚至逆转IDD发生.进一步揭示IDD遗传学机制,有助于通过转基因方法治疗IDD.     

椎间盘退行性变机制的研究进展

正椎间盘是脊柱中连接两个相邻椎体的纤维软骨盘,其中央部为富含弹性胶状物质的髓核,周围部是由多层纤维软骨环按同心圆排列而成的纤维环。椎间盘具有承受压力、缓冲震荡冲击、保护脊髓等作用。椎间盘退行性变(IDD)会引起一系列的临床症状,是引起下腰痛最主要的原因之一。一直以来,研究者们对引起IDD的过程不断进行观察与造模,目前也已有大量的IDD过程与机制的研究_([1-2])。总体而言,IDD是在椎间盘组织内髓核细胞数目减     

干细胞移植治疗椎间盘退变的研究现状

<正>椎间盘退变（intervertebral disc degeneration,IDD）是与年龄有关、多因素导致的生物学退变,以椎间盘高度的降低、含水量降低、软骨终板钙化、细胞外基质减少等一系列微环境失衡为特点,最终导致椎间盘组织结构完整性丧失、脊柱的活动和功能受限。IDD可导致椎间盘源性腰痛、腰椎间盘突出症、腰椎管狭窄症、退行性腰椎滑脱、     

椎间盘退变的遗传学机制研究进展

椎间盘退变（intervertebral disc degeneration，IDD）是一系列脊柱退行性疾病的发生前提和基础病理过程，临床上常表现为椎管狭窄、脊柱节段不稳、腰腿痛、颈椎病、椎间盘突出等病症。传统的观点认为IDD主要与过度的身体负荷引起的损伤以及衰老过程中伴随出现的变化有关。随着相关研究的不断深入，人们对IDD及其病因的认识有了巨大的进步。近年来的一些研究，特别是对同卵双生者IDD的研究发现遗传因素可能在IDD的发生发展中起重要作用。本文就相关研究情况作一综述。     

MicroRNA与椎间盘退行性变关系的研究进展

<正>随着对椎间盘退行性变(IDD)机制研究的深入,越来越多的研究表明micro RNA在IDD中扮演着重要的角色,较多micro RNA在人正常椎间盘和退变椎间盘组织中存在差异性表达,这些差异性表达的micro RNA在细胞凋亡、蛋白水解酶和细胞外基质的降解等生物过程中发挥着重要作用[1]。IDD是引起下腰痛的主要原因之一[2],严重危害公众健康,并给患者带来巨大的经济负担[3]。目前IDD的     

褪黑素介导抗炎、抗氧化、抗骨质疏松作用在椎间盘退变修复中的研究进展

目前,椎间盘退行性疾病（disc degeneration disease,DDD）已成为临床上中老年人的常见病,且发病年龄有年轻化趋势。椎间盘退变（intervertebral disc degeneration,IDD）是指椎间盘（intervertebral disc,IVD）在内外部因素共同作用下引起的老化、退化等一系列生理、病理过程,被认为是DDD的基本病理过程,是引发患者腰痛的主要原因,因此修复IDD是治疗DDD的重点。IDD过程中伴随着炎症介质的产生、炎症相关信号通路的活化以及氧化应激的发生。褪黑素作为一种吲哚类激素,具有显著的抗炎及抗氧化作用,近年来受到研究者关注,越来越多的研究表明褪黑素对IVD具有保护作用,对治疗骨质疏松症（osteoporosis,OP）也有一定的作用,其有望成为IDD修复的治疗药物。笔者拟对褪黑素在椎间盘退变修复中的最新研究进展做一综述,以期为后续研究及IDD的早期药物干预和修复治疗策略提供思路。     

间充质干细胞治疗椎间盘退行性变的研究进展

<正>椎间盘退行性变(IDD)是引起下腰痛的主要病因之一~([1]),IDD导致的椎间隙狭窄是下腰痛重要发病机制~([2-3])。成人椎间盘是人体最大的无血管组织且细胞含量较少~([4])。IDD不同于正常衰老,衰老属于生理现象,不引起疼痛,而IDD则会引起髓核细胞(NPC)活性下降、数量减少,椎间隙高度丢失等,从而产生下腰痛。IDD的非手术治疗~([5])和手术     

椎间盘内紊乱症

椎间盘内紊乱症(internal disk derangement,IDD)的定义为椎间盘内的病理改变导致下腰痛,而椎间盘的外形没有或仅有极小的改变。这些病理变化包括椎间盘结构的破裂,如纤维环的破裂和(或)原发性、继发性生物化学炎症改变。IDD不能和椎间盘突出及椎间盘膨出相混淆,椎间盘膨出一般是退行性变的正常改变,它没有重要的临床意义。椎间盘突出症包括椎间盘突出、脱出及游离碎片,它一般会引起坐骨神经痛,它们的治疗策略与IDD完全不同。另外IDD也不能和椎间盘变性相混淆,IDD患者的放射学表现正常,即使有椎间隙狭窄也很     

Vasopressor hormone response following mesenteric traction during major abdominal surgery

Background : We investigated the vasopressor hormone response following mesenteric traction (MT) with hypotension due to prostacyclin (PGI₂) release in patients undergoing abdominal surgery with a combined general and epidural anesthesia. Methods : In a prospective, randomized, placebo-controlled study we administered 400 mg ibuprofen (i.v.) in 42 patients scheduled for abdominal surgery. General anesthesia was combined with epidural anesthesia (T4-L1). Before as well as 5, 15, 30, 45, and 90 min after MT we recorded plasma osmolality, hemodynamics and measured 6-keto-PGFlα (stabile metabolite of PGI₂), TXB₂ (stabile metabolite of thromboxane A₂) active renin, and arginine vasopressin (AVP) plasma concentrations by radioimmunoassay. Catecholamine levels were assessed by high-pressure liquid chromatography (HPLC) with electrochemical detection. Results : Following MT, arterial hypotension occurred along with a substantial PGI₂ release. This was completely abolished by ibuprofen administration. Although plasma levels of 6-keto-PGF_1α (1133 (708) vs. 60 (3) ng/L, median (median absolute deviation), P=0.0001, placebo vs. ibuprofen) remained significantly elevated, blood pressure was restored within 30 min after MT in the placebo group. At the same point in time plasma concentrations of TXB² (164 (87) vs. 58 (1) ng/L, P=0.0001), epinephrine (46 (33) vs. 14 (6) ng/L, P=0.001), AVP (41 ± (18) vs. 12 (7) ng/L, P=0.0004), and active renin (27 (12) vs. 12 (4) ng/L, P = 0.001) were significantly higher in placebo-treated patients. Conclusion : Under combined general and epidural anesthesia arterial hypotension following MT due to endogenous PGI₂ release is associated with enhanced release of AVP, active renin, epinephrine and thromboxane A₂, presumably contributing to hemodynamic stability within 30 min after MT.     

A comparison of the inhibitory effects of four volatile anaesthetics on the metabolism of chlorzoxazone, a substrate for CYP2E1, in rabbits

Background: Halothane inhibits in vitro and in vivo activity of cytochrome P-450 (CYP) 2E1. There are several fluorinated volatile anaesthetics besides halothane, and most of them are defluorinated by CYP2E1. It is unclear whether other fluorinated anaesthetics inhibit the in vivo activity of CYP2E1.
Methods: We compared the inhibitory effects of therapeutic concentrations of four inhalational anaesthetics, halothane, enflurane, isoflurane, and sevoflurane, on chlorzoxazone metabolism in rabbits receiving artificial ventilation.
Results: All four inhalational anaesthetics decreased arterial blood pressure and increased plasma chlorzoxazone concentration. However, no significant differences in the plasma chlorzoxazone concentration were found between the four anaesthetics. The estimated chlorzoxazone clearance increased after beginning inhalation with all four agents, but no significant difference in clearance was noted between agents.
Conclusions: At therapeutic concentrations, the in vivo inhibitory effect on chlorzoxazone metabolism was similar for all four inhalational anaesthetics examined, even though their chemical characteristics and extent of hepatic metabolism differ considerably.     

A Teaspoon Pump for Pumping Blood with High Hydraulic Efficiency and Low Hemolysis Potential

Abstract: Virtually all blood pumps contain some kind of rubbing, sliding, closely moving machinery surfaces that are exposed to the blood being pumped. These valves, internal bearings, magnetic bearing position sensors, and shaft seals cause most of the problems with blood pumps. The original teaspoon pump design prevented the rubbing, sliding machinery surfaces from contacting the blood. However, the hydraulic efficiency was low because the blood was able to "slip around" the rotating impeller so that the blood itself never rotated fast enough to develop adequate pressure. An improved teaspoon blood pump has been designed and tested and has shown acceptable hydraulic performance and low hemolysis potential. The new pump uses a nonrotating "swinging" hose as the pump impeller. The fluid enters the pump through the center of the swinging hose; therefore, there can be no fluid slip between the revolving blood and the revolving impeller. The new pump uses an impeller that is comparable to a flexible garden hose. If the free end of the hose were swung around in a circle like half of a jump rope, the fluid inside the hose would rotate and develop pressure even though the hose impeller itself did not "rotate"; therefore, no rotating shaft seal or internal bearings are required.     

Microspheres Based Detoxification System: A New Method in Convective Blood Purification

Abstract: A variety of protein-bound or hydrophobic substances, accumulating as a result of pathologic conditions such as exogenous or endogenous intoxications, are removed poorly by conventional detoxification methods because of low accessibility (hemodialysis), insufficient adsorption capabilities (hemosorption), low efficiency (peritoneal dialysis), or economic limitations (high-volume plasmapheresis). Combining advantages of existing methods with microspheric technology, a module-based system was designed. Major operating parameters of the latter can be modified to allow for adjustment to individual clinical situations. An extracorporeal blood circuit including a plasmafilter is combined with a secondary high-velocity plasma circuit driven by a centrifugal pump. Different microspheric adsorbers can be combined in one circuit or applied in sequence. Thus, a prolonged treatment can be tailored using specially designed selective adsorber materials. Comparing this system with existing methods (high-flux hemodialysis, molecular adsorbent recycling system), results from our in vitro studies and animal experiments demonstrate the superior efficiency of substance removal.     

Is the recovery profile of mivacurium independent of the rate of decay of its plasma concentration in patients with normal plasma cholinesterase activity?

Background: The duration of action of muscle relaxants is poorly correlated to the rate of decay of their plasma concentration. The plasma concentration of mivacurium may rapidly decrease below its active concentration because of the extensive hydrolysis of mivacurium. By inflating a tourniquet on one upper limb for 3 min after the administration of atracurium, mivacurium or vecuronium, we studied the influence of the initial decline of their plasma concentration on their effect. Methods: In 50 patients anaesthetised with thiopental, isoflurane and fentanyl, the effect of bolus doses of 0.15 or 0.25 mg . kg^?1 mivacurium (MIV 15, MIV 25), 0.3 or 0.5 mg . kg^?1 atracurium (ATR 30, ATR 50) and 0.06 or 0.1 mg . kg^?1 vecuronium (VEC 06, VEC 10) were measured on both arms (evoked response of the adductor pollicis to train-of-four stimulation every 12 s), a tourniquet being applied on one arm just before and during 3 min after the muscle relaxant bolus. Results: Tourniquet inflation of 3 min almost abolished the neuromuscular effect of mivacurium. In the vecuronium groups and in the ATR 50 group, tourniquet inflation did not modify the maximum degree of depression of the twitch response. Also, the duration of action of vecuronium was unaffected by the tourniquet. In the ATR 30 group, times to return of the twitch response to 25% (duration 25%) and 75% (duration 75%) of control response were significantly shorter in the cuffed arm, 23 min vs 27 min, and 41 min vs 45 min, respectively. In the ATR 50 group, only duration 25% was significantly shorter in the cuffed arm (41 min vs 45 min). Conclusion: The results suggest that the rate of decline of the plasma concentration of mivacurium is so rapid, that a very low and almost clinically ineffective concentration is present as soon as 3 min after its administration. The results also indicate that the recovery from a mivacurium-induced neuromuscular blockade is not influenced by the rate of decay of its plasma concentration in patients with genotypically normal plasma cholinesterase.     

Membranes in Artificial Organs

Abstract: Membrane processes play a pivotal and enabling role in modern replacement therapy for acute and chronic organ failure and in the management of immunologic diseases. In fact, virtually all contemporary extracorporeal blood purification methods employ membrane devices, and the next generation of artificial organs and tissue engineering therapies are almost certain to be similarly grounded in membrane technology. In this short essay, we comment on the similarities and differences among synthetic membranes and their natural counterparts and also provide a critical overview of the demographics and technology of hemodialysis, hemofiltration, apheresis, oxygenation, and emerging membrane technologies and applications.     

Tissue perfusion in relation to cardiac output during continuous positive-pressure ventilation and administration of propranolol or verapamil

Background : Our objective was to determine whether administration of propranolol or verapamil modifies the hemodynamic adaptation to continuous positive-pressure ventilation (CPPV), in particular the regional distribution of cardiac output (CO).
Methods : General hemodynamics and regional blood flows assessed by microsphere technique (15 (μm) were recorded in 16 anesthetized pigs during spontaneous breathing (SB) and CPPV with 8 cm H₂O end-expiratory pressure (CPPV8) before and after intravenous administration of propranolol (0.3 mg · kg⁻¹ followed by 0.15 mg · kg⁻¹ · h⁻¹, n=8) or verapamil (0.1 mg · kg⁻¹ followed by 0.3 mg · kg⁻¹ · h⁻¹, n=8).
Results : CPPV8 depressed CO by 25% without shifts in its relative distribution with the exception of a noteworthy increase in adrenal perfusion. Propranolol increased arterial blood pressure, and due to a fall in heart rate, CO dropped by 25%. The kidneys and, to a lesser extent, the splanchic region and central nervous system received increased fractions of the remaining CO at the expense of skeletal muscle flow. Similar patterns were seen during SB and CPPV8 such that the combination of propranolol and CPPV8 depressed CO by 50%. The circulatory effects of verapamil were less evident but myocardial perfusion tended to increase.
Conclusions : The combination of propranolol or verapamil with CPPV does not result in any specific hemodynamic interaction in anesthetized pigs, except that the combined effect of propranolol and CPPV may severely reduce CO.     

Volatile anaesthetics reduce adhesion of blood platelets under low-flow conditions in the coronary system of isolated guinea pig hearts

Background : Inhibitory effects of volatile anaesthetics on platelet aggregation have been demonstrated in several studies. However, the influence of volatile anaesthetics on intracoronary platelet adhesion has not been elucidated so far.
Methods : Isolated hearts of guinea pigs were perfused with buffer in the absence or presence of volatile anaesthetics (0.5 and 1 MAC) at constant coronary flow rates of 5 ml/min for 25 min, then 1 ml/min for 30 min and again 5 ml/min for 10 min. Before, during and after low-flow perfusion, a bolus of human platelets was applied into the coronary system. To simulate thrombogenic conditions, 0.3 U/ml human thrombin was infused during low-flow perfusion and reperfusion. The number of platelets sequestered to the endothelium was calculated from the difference between coronary in- and output of platelets. The myocardial production of lactate and consumption of pyruvate and coronary perfusion pressure were also determined.
Results : At a flow rate of 5 ml/min only about 3% of the applied platelets did not emerge from the coronary system, in any group. In contrast, 13.1±1.2% (mean±SEM) of infused platelets became adherent in low-flow perfusion in the control group without anaesthetic. The adherence was reduced with each 1 MAC isoflurane (to 6.2±1.2%), sevoflurane (to 4.4±0.9%) or halothane (to 3.2±1.5%) (each P <0.05 vs. control). Volatile anaesthetic, 0.5 MAC, did not inhibit platelet adhesion to a statistically significant extent in any case. Perfusion pressure and metabolic parameters were not statistically different between the control and the hearts exposed to anaesthetics.
Conclusion : Volatile anaesthetics in a concentration of 1 MAC can reduce the adhesion of platelets in the coronary system under reduced flow conditions. This action does not arise from vasodilation or inhibition of ischaemic stress.     

Bariatric Surgery in Some "Central and East-European (former Eastern bloc)"Countries - Current Status and Prediction for the Next Millennium

Background: Obesity is increasing globallly, including in the formerly "Eastern Bloc" countries. Methods: A survey was made of obesity and bariatric surgery. Results: In the 8 East and Central European countries studied, with total population 300 million, roughly 43% of the population was overweight (BMI 25-30), 23% obese (BMI > 30), with about 15 million people morbidly obese (BMI > 40). From 0-10 morbidly obese individuals/100,000/year undergo bariatric surgery. Conclusion: Most countries were found to provide inadequate treatment for obesity.The majority of the morbidly obese are not treated effectively. However, health-care awareness of obesity and bariatric surgeons are slowly increasing.     

Dilemma of Membrane Biocompatibility and Reuse

Abstract: Numerous articles have been published on the multiple use of dialyzers and on the effect of different reprocessing chemicals and techniques on the dialyzer biocompatibility and performance. The results often appear contradictory, especially those comparing standard biocompatibility parameters. Despite this confusion, a discerning review of the published works allows certain limited conclusions to be drawn. Reprocessing of used hemodialyzers changes the biocompatibility profile of a dialyzer as defined by the parameters complement activation. leukopenia, and cytokine release. The effect of reprocessing depends on the chemicals and reprocessing technique applied and also on the type of membrane polymer being subjected to the reprocessing procedure. Reports of pyrogenic reactions indicate that the flux of the membrane also influences how suitable it is for safe reuse. An increased risk of allergic and pyrogenic reactions appears to be associated with dialyzer reuse. Furthermore, there has been a lack of investigations into the immunologic effect of the layer of adsorbed and chemically altered proteins that remains on the inner surface of reprocessed dialyzers. We conclude that the clinical benefit of dialyzer reuse cannot be generally accepted from a biocompatibility point of view.