NLRP3炎性小体与急性胰腺炎的研究进展

目的探讨NLRP3炎性小体与急性胰腺炎病情的发展,以及与急性胰腺炎导致的胰腺原位和胰腺外损伤的关系。方法对近年来国内外有关NLRP3炎性小体与急性胰腺炎病情发展,胰腺原位和胰腺外脏器损伤研究的相关文献进行综述。结果急性胰腺炎发生时,NLRP3炎性小体激活参与了急性胰腺炎时各脏器的损伤,NLRP3炎性小体激活越多,对机体的损伤越严重,通过对NLRP3炎性小体激活机制的调节,可以减少NLRP3炎性小体的激活,并最终减轻各脏器的损伤。结论 NLRP3炎性小体的激活参与了急性胰腺炎的进程,但仍需进一步临床研究予以验证。     

NLRP3炎性小体在激素性股骨头坏死骨代谢及其稳态中的作用

大量的糖皮质激素使用导致股骨头中骨代谢及稳态失衡是激素性股骨头坏死的重要机制之一。细胞焦亡关键因子NLRP3炎性小体在SANFH机制中发挥着重要作用，明确NLRP3炎性小体的结构，激活途径和调控机制，以及NLRP3炎性小体和下游炎性因子IL-1β、IL-18对激素性股骨头坏死中成骨细胞、破骨细胞以及骨髓间充质干细胞的作用机制，将为激素性股骨头坏死的防治提供新的思路与靶点。该文对NLRP3炎性小体在骨代谢及稳态中的相关作用机制进行综述，系统阐述NLRP3炎性小体与SANFH成骨和破骨分化中的具体作用机制，以期为临床治疗和基础研究提供一定的借鉴。     

低氧对炎性环境下髓核细胞凋亡的作用及机制

目的 探讨低氧对炎性环境下髓核细胞凋亡的影响及作用机制。方法 体外培养大鼠原代髓核细胞，采用低氧小室进行低氧干预，采用促炎因子肿瘤坏死因子-α（TNF-α）刺激髓核细胞模拟炎性环境。通过流式细胞术及TUNEL染色检测髓核细胞凋亡情况，通过蛋白质印迹法检测凋亡相关蛋白表达水平，明确低氧对髓核细胞凋亡的影响；随后通过荧光定量PCR及酶联免疫吸附试验评估炎性环境下髓核细胞内炎性反应情况，并通过蛋白质印迹法分析髓核细胞内NLRP3炎性小体激活水平；最后采用NLRP3炎性小体激动剂QS-21，通过回复实验明确NLRP3炎性小体在低氧调控髓核细胞凋亡中的作用。结果 低氧对正常环境下髓核细胞凋亡无明显影响，但能抑制炎性环境下髓核细胞凋亡。在炎性环境下，髓核细胞炎性细胞因子白细胞介素（IL）-1β、IL-8、IL-18的表达及分泌增加，细胞内NLRP3炎性小体激活，而低氧干预能缓解上述改变。回复实验表明，NLRP3炎性小体激动剂QS-21可削弱低氧对炎性环境下髓核细胞凋亡的抑制作用。结论 低氧通过抑制NLRP3炎性小体激活缓解炎性环境下髓核细胞凋亡。     

NLRP3炎性小体及其与肾脏疾病的研究进展

<正>Nod样受体蛋白3(NLRP3)炎性小体是一种分子量约为700 Kda的大分子多蛋白复合体,具有调控机体慢性炎症反应的功能,目前炎性小体在自身免疫性疾病和慢性炎症反应等病理过程中的作用及意义倍受关注,许多疾病均涉及NLRP3炎性体-caspase-1-IL-1/IL-18轴的激活。通过近几十年的基础研究,由于对于Toll样受体(toll-like receptors,TLRs)、     

NLRP3炎性小体与慢性疼痛

慢性疼痛是一类机制复杂的疾病,神经炎症被广泛认为是一种重要的促进机制。而NLRP3炎性小体是模式识别受体激活后形成的一种多蛋白复合体,在接收到外源性和内源性信号后,能促进炎性细胞因子的产生,继而引发神经炎症。众多证据表明,NLRP3炎性小体介导的神经炎症在慢性疼痛的发生发展中起着重要作用,靶向NLRP3可能是一种新颖而有效的慢性疼痛治疗策略,是近年来研究的热点之一。基于上述背景,本文综述了NLRP3炎性小体在慢性疼痛中作用的最新进展。     

线粒体-NOD样受体热蛋白结构域相关蛋白3炎症小体通路在急性肺损伤中的作用

NOD样受体热蛋白结构域相关蛋白3(NOD like receptor thermal protein domain associated protein 3, NLRP3)炎症小体是参与炎症反应的一种复合物, 已被证实参与了急性肺损伤(acute lung injury, ALI)的发生、发展, 其激活机制非常复杂, 线粒体活性氧(reactive oxygen species, ROS)以及线粒体DNA(mitochondria DNA, mtDNA)的积累会激活NLRP3炎症小体, 但线粒体在NLRP3炎症小体介导ALI过程中所发挥的作用远不止如此, 阐明临床上各种类型的肺损伤激活线粒体-NLRP3炎症小体通路的完整机制可能为未来治疗相关疾病提供新的思路。文章就NLRP3炎症小体的结构、线粒体-NLRP3炎症小体通路的激活机制及其在ALI中的作用展开综述, 为ALI的临床治疗提供新的思路与策略。     

含pyrin结构域NOD样受体家族3炎性小体的翻译后修饰及其在脓毒症发生发展中的作用

翻译后修饰(post-translational modification, PTM)主要包括磷酸化、泛素化、烷基化、S-亚硝基化和ADP-核糖基化等,能够通过多分子多位点调控含pyrin结构域NOD样受体家族3(NOD-like receptors family pyrin domain containing 3, NLRP3)炎性小体。NLRP3炎性小体激活将造成炎症级联反应不断扩大。而这种炎症反应紊乱是推动脓毒症进展的重要因素。文章详细阐述了NLRP3炎性小体的PTM,并介绍了NLRP3的PTM在脓毒症中的作用,以期干预NLRP3炎性小体的活化,进而调控炎症,为未来脓毒症治疗提供新思路。     

炎性小体的研究进展

炎性小体是由多种蛋白质组成的复合体,分子量约700 kD,此概念由Tschopp研究小组于2002年首次提出[1].炎性小体能够调节胱冬肽酶-1(caspase-1)的活化进而在天然免疫防御的过程中促进细胞因子前体pro-IL-1β和pro-IL-18的切割成熟[2];还能调节caspase-1依赖的形式编程性细胞死亡(pyroptosis)[3],诱导细胞在炎性和应激的病理条件下死亡.目前已发现的炎性小体主要有4种,即NLRP1、NLRP3、IPAF和AIM2炎性小体.已发现的炎性小体一般均含有凋亡相关微粒蛋白(apoptosis-associated speck-like protein containing CARD,ASC)、caspase蛋白酶及一种NOD样受体(NOD-like receptor,NLR)家族蛋白(如NLRP1)或HIN200家族蛋白(如AIM2).炎性小体活性异常与人类的多种遗传疾病或后天疾病发生相关,如遗传性周期发热综合征等[4].     

异氟醚通过NLRP3炎性小体调控炎症微环境的研究

目的探讨异氟醚处理对小胶质细胞NLR家族热蛋白结构域包含蛋白3(NLR family pyrin domain containing 3,NLRP3)炎性小体通路相关炎症微环境的调控作用。方法脂多糖(LPS;1μg·m L-1)预活化小胶质细胞株(BV2)30 min,分别采用异氟醚单独处理和LPS预活化后异氟醚处理6小时。实时荧光定量聚合酶链反应(q RT-PCR)检测NLRP3的m RNA表达量;蛋白免疫印迹(Western-blot)分析NLPR3蛋白表达变化;酶联免疫吸附试验(ELISA)检测炎症因子白介素-1β(interleukin-1β,IL-1β)的分泌情况;CCK8细胞活性试验评估异氟醚处理的毒性作用。结果q RT-PCR及Western-blot结果表明异氟醚单独处理不引起BV2细胞的NLRP3表达变化,LPS预活化后异氟醚处理上调预活化BV2细胞的NLRP3表达;ELISA结果表明异氟醚单独处理不引起BV2细胞IL-1β分泌,LPS预活化后异氟醚处理促进活BV2细胞IL-1β分泌;各组实验条件下BV2细胞活性均无显著改变。结论异氟醚可通过激活NLRP3炎性小体调控小胶质细胞IL-1β的表达。     

核苷酸结合寡聚化结构域样受体蛋白3炎性小体在心肺转流大鼠围术期神经认知障碍中的作用

目的探讨核苷酸结合寡聚化结构域样受体蛋白3(NLRP3)炎性小体在心肺转流(CPB)大鼠围术期神经认知障碍(PND)中的作用。方法成年雄性SD大鼠30只,体重350～450 g,进行Morris水迷宫训练5 d后随机分为三组,每组10只:假手术组(S组)、CPB组(C组)和CPB+NLRP3炎性小体抑制剂Ac-YVAD-cmk组(Y组)。S组进行双侧隐动脉、右大隐静脉和右颈内静脉穿刺置管,但不进行CPB;C组穿刺置管后行CPB 60 min;Y组在CPB前30 min给予Ac-YVAD-cmk 8 mg/kg腹腔注射,穿刺置管后行CPB 60 min。术后第3天采用Morris水迷宫实验评估大鼠认知功能,ELISA法检测血浆和海马组织IL-1β和IL-18浓度,Western blot法检测海马组织NLRP3、凋亡相关点样蛋白(ASC)和半胱氨酸蛋白水解酶-1前体(pro-caspase-1)蛋白含量,TUNEL法检测海马组织凋亡情况,计算凋亡指数。结果与S组比较,C组和Y组逃避潜伏期明显延长(P0.05),120 s穿越原平台次数明显减少(P0.05),血浆和海马组织IL-1β和IL-18浓度、NLRP3、ASC和pro-caspase-1蛋白含量以及凋亡指数明显升高(P0.05)。与C组比较,Y组逃避潜伏期明显缩短(P0.05),120 s穿越原平台次数明显增多(P0.05),血浆和海马组织IL-1β和IL-18浓度、NLRP3、ASC和pro-caspase-1蛋白含量以及凋亡指数明显降低(P0.05)。结论 CPB后大鼠PND可能与NLRP3炎性小体的激活有关,使用NLRP3炎性小体抑制剂可减轻大鼠PND的发生。     

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 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.     

Influence of dopexamine hydrochloride on haemodynamics and regulators of circulation in patients undergoing major abdominal surgery

Background: Catecholaminergic support is often used to improve haemodynamics in patients undergoing major abdominal surgery. Dopexamine is a synthetic vasoactive catecholamine with beneficial microcirculatory properties. Methods: The influence of perioperative administration of dopexamine on cardiorespiratory data and important regulators of macro- and microcirculation were studied in 30 patients undergoing Whipple pancreaticduodenectomy. The patients received randomized and blinded either 2 μg · kg^?1 · min^?1 of dopexamine (n=15) or placebo (n=15, control group). The infusion was started after induction of anaesthesia and continued until the morning of the first postoperative day. Endothelin-1 (ET-1), vasopressin, atrial natriuretic peptide (ANP), and catecholamine plasma levels were measured from arterial blood samples. Measurements were carried out after induction of anaesthesia, 2 h after onset of surgery, at the end of surgery, 2 h after surgery, and on the morning of the first postoperative day. Results: Cardiac index (CI) increased significantly in the dopexamine group (from 2.61±0.41 to 4.57±0.78 1 · min^?1 · m^?2) and remained elevated until the morning of the first postoperative day. Oxygen delivery index (DO₂I) and oxygen consumption index (VO₂I) were also significantly increased in the dopexamine group (DO₂I: from 416±91 to 717±110 ml/m² · m²; VO₂I: from 98±25 to 157±22 ml/m² · m²), being significantly higher than in the control group. pHi remained stable only in the dopexamine patients, indicating adequate splanchnic perfusion. Vasopressive regulators of circulation increased significantly only in the untreated control patients (vasopressin: from 4.37±1.1 to 35.9±12.1 pg/ml; ET-1: from 2.88±0.91 to 6.91±1.20 pg/ml). Conclusion: Patients undergoing major abdominal surgery may profit from prophylactic perioperative administration of dopexamine hydrochloride in the form of improved haemodynamics and oxygenation as well as beneficial influence on important regulators of organ blood flow.