肾小管上皮细胞损伤在慢性肾脏疾病进展中的作用

肾小管间质病变程度是决定各种肾脏疾病预后的重要因素，而肾小管上皮细胞的损伤和损伤反应可进一步加重肾间质病变。疾病状态时在缺氧、蛋白尿及多种炎症／细胞因子作用下，肾小管上皮细胞可活化、增殖，并分泌多种炎症因子、趋化因子和血管活性因子进入肾间质，加重肾间质的炎症和纤维化进程。受损的肾小管上皮细胞除了发生坏死或凋亡外，还可能发生表型转化为肌纤维母细胞进入间质，直接参与肾间质纤维化。提示肾小管上皮细胞损伤和损伤后的反应是加重肾间质炎症、纤维化和慢性肾脏持续进展的重要因素。     

肾小管上皮细胞损伤在慢性肾脏疾病进展中的作用

肾小管间质病变程度是决定各种肾脏疾病预后的重要因素 ,而肾小管上皮细胞的损伤和损伤反应可进一步加重肾间质病变。疾病状态时在缺氧、蛋白尿及多种炎症 /细胞因子作用下 ,肾小管上皮细胞可活化、增殖 ,并分泌多种炎症因子、趋化因子和血管活性因子进入肾间质 ,加重肾间质的炎症和纤维化进程。受损的肾小管上皮细胞除了发生坏死或凋亡外 ,还可能发生表型转化为肌纤维母细胞进入间质 ,直接参与肾间质纤维化。提示肾小管上皮细胞损伤和损伤后的反应是加重肾间质炎症、纤维化和慢性肾脏持续进展的重要因素     

细胞因子与肾小管间质纤维化

近年来研究发现肾小管间质病变较肾小球病变在肾脏病进展中意义更为重要，细胞因子通过自分泌或旁分泌的方式作用于肾小管上皮细胞使其发生凋亡和/或表型转化，则在肾小管间质纤维化中起着重要作用。本文就细胞因子与肾小管间质纤维化的关系作一综述。     

细胞因子与肾小管间质纤维化

近年来研究发现肾小管间质病变较肾小球病变在肾脏病进展中意义更为重要,细胞因子通过自分泌或旁分泌的方式作用于肾小管上皮细胞使其发生凋亡和/或表型转化,则在肾小管间质纤维化中起着重要作用。本文就细胞因子与肾小管间质纤维化的关系作一综述。     

人类肾小球肾炎中肾小管及间质细胞表型转化的研究

目的观察人类肾小球肾炎时肾小管-间质细胞发生的表型转化现象.方法对34例肾小球肾炎患者肾穿刺标本进行免疫组织化学染色,观察α-平滑肌肌动蛋白(α-SMA)、波形蛋白(vimentin,Vim)、角蛋白(cytokeratin,CK)、增殖细胞核抗原(PCNA)及Ⅳ型胶原(ColⅣ)表达,并进行透射电镜观察.结果在人类肾小球肾炎中,肾小管上皮细胞可出现间质细胞标志物波形蛋白及α-SMA表达,并可游离至肾间质中;肾间质中α-SMA阳性的肌纤维母细胞(myofibroblast,Myo-FB)增多,与波形蛋白阳性的间质细胞分布区域近似,并伴有Ⅳ型胶原的聚积增多.α-SMA阳性的肾小管-间质细胞均有增殖现象.结论人类肾小球肾炎时,肾小管上皮细胞和间质成纤维细胞可发生向肾间质肌纤维母细胞的表型转化,参与肾间质纤维化的发展.     

肾小球硬化中肾小管间质细胞表型转化及肾疏宁的干预作用

目的 :探讨肾小球硬化大鼠肾小管上皮细胞及间质成纤维细胞的表型转化情况及中药复方肾疏宁的作用。方法 :SD大鼠随机分为假手术组、模型组、模型组 +肾疏宁治疗组、模型组 +苯那普利治疗组。采用单侧肾切除并阿霉素尾静脉注射的方法建立大鼠肾小球硬化模型 ,8周末光镜及透射电镜观察肾组织病理 ,免疫组织化学染色法观察大鼠肾小管上皮细胞及间质成纤维细胞α -平滑肌肌动蛋白 (alphasmoothmuscleactin ,α -SMA)和转化生长因子 - β1(transforminggrowthfactorβ1,TGF - β1)表达情况 ,用计算机病理图像分析软件检测肾小管间质α -SMA和TGF - β1染色阳性相对面积 ,和肾间质纤维化相对面积。同时观察肾疏宁对肾小球硬化大鼠体重、尿蛋白、血总蛋白、白蛋白、尿素氮、肌酐的影响。结果 :假手术组大鼠肾小管间质α -SMA少量表达 ,TGF - β1微量表达 ,肾小球硬化模型组大鼠肾小管间质α-SMA明显阳性表达 (P <0 .0 1) ,TGF - β1显著阳性表达 (P <0 .0 1) ,肾小管间距加宽 ,肾间质纤维化和大量淋巴细胞和单核细胞浸润 ,血白蛋白、总蛋白明显降低 (P <0 .0 1) ,尿蛋白、血尿素氮、肌酐明显升高(P <0 .0 1) ,肾疏宁治疗组和苯那普利治疗组 2 4h尿蛋白排泄量、血尿素氮、肌酐明显降低 (P <0 .0 1) ,肾小管间质     

移植肾排异反应中肾小管上皮细胞的表型转化

目的 观察人移植肾肾穿刺标本不同排异反应病变中肾小管上皮细胞表型转化状态,探讨排异反应与肾小管上皮细胞表型转化的相关性。 方法 免疫组织化学SP法检测55例移植肾穿刺不同病变组中肾小管上皮细胞α平滑肌肌动蛋白（α-SMA）的表达。 结果 各组萎缩病变的肾小管上皮细胞均有α-SMA阳性表达,表现为近基底膜处胞质阳性染色,提示出现了表型转化。在无萎缩病变的肾小管中,仍有部分肾小管细胞呈α-SMA阳性染色。7例基本正常病例组均无肾小管上皮细胞的表型转化。28例急性T细胞介导排异 IA级病例组中,1例肾小管上皮细胞α-SMA阳性表达率为25%~50%,3例为10%~25%。14例排异反应IB 级中,1例α-SMA阳性表达率达50%以上,2例25%~50%,2例10%~25%。 结论 随着急性T细胞介导性排异反应加重,肾小管上皮细胞发生表型转化的现象明显增强。     

肾小管上皮细胞凋亡在肾间质纤维化中的作用

肾小管上皮细胞凋亡是肾间质纤维化的重要发病机制之一,多种细胞因子参与了肾小管上皮细胞凋亡而影响肾间质纤维化的进展,本文对肾小管上皮细胞凋亡在肾间质纤维中的病理学意义、作用机制及治疗干预的研究作一综述.     

金属蛋白酶组织抑制剂1在大鼠肾小管间质损害中的表达及其意义

目的 观察单侧输尿管梗阻(UUO)大鼠模型中金属蛋白酶组织抑制剂1(TIMP-1)在肾小管间质中的表达部位、动态变化及其与肾小管问质损害的关系。方法 制备UUO大鼠模型,采用免疫组织化学方法检测UUO术后第1、3、5、7、14天肾小管间质中TIMP-1、α-平滑肌肌动蛋白(SMA)、增殖细胞核抗原(PCNA)和单核巨噬细胞抗原(ED)-1的表达及其与输尿管梗阻后肾小管间质损害的关系。结果 UUO术后第1天肾间质可见少量TIMP-1表达细胞,第3～7天TIMP-1表达明显增加,主要表达于肾小管上皮细胞和肾间质。UUO术后第3天肾小管PCNA表达达高峰,随后下降,而肾间质PCNA水平于第7～14天仍较高。UUO术后第3天肾间质成纤维细胞及肾小管上皮细胞可检出α-SMA表达并随时间递增。α-SMA阳性面积与肾间质相对面积成正相关(r=0.924,p<0.01)。TIMP-1表达与间质相对面积(r=0.835,P<0.05)及α-SMA阳性面积(r=0.922,P<0.01)成正相关。结论 TIMP-1蛋白质于肾小管间质病变早期表达于肾小管间质,早于肾间质纤维化出现,其表达量与肾间质α-SMA表达及肾间质相对面积呈正相关并随病变进展逐渐增加。TIMP-1在肾小管上皮细胞和问质细胞的高表达及肾小管上皮细胞和间质细胞增殖可能参与介导UUO术后肾小管间质损害。     

肾络宁对IgA肾病大鼠肾小管间质损害的实验研究

目的：探讨IgA肾病大鼠肾小管间质损害及中药复方肾络宁的干预作用。方法：SD大鼠随机分为正常组、模型组、肾络宁组、肾炎康复片组。采用牛血清白蛋白和葡萄球菌肠毒素B复合感染的方法建立大鼠IgA肾病模型；实验共16周，药物干预后常规检测尿红细胞、尿蛋白、血尿素氮、肌酐、尿NAG酶，以及免疫荧光观察肾组织病理；原住杂交，免疫组化及计算机图像分析系统观察大鼠肾小管间质损害的病理变化，以及Ⅲ型胶原（Col-Ⅲ）、转化生长因子β1（TGF-β1）、纤溶酶原激活物抑制剂-1（PAI-1）、基质金属蛋白酶-1（MMP-1）、基质金属蛋白酶组织抑制剂-1（TIMP-1）的表达情况。结果：模型组出现肾小管上皮细胞变性，线粒体结构消失，数量减少，间质成纤维细胞增生及胶原纤维形成；尿红细胞、尿蛋白、NAG酶、血肌酐、尿素氮明显增高，Col—Ⅲ、TGF-β1、PAI-1、TIMP-1表达明显增高，MMP-1表达明显降低。肾络宁及肾炎康复片组小管间质损害明显减轻；血尿、蛋白尿、血肌酐、尿素氮、尿NAG明显降低，Col—Ⅲ、TGF-β1、PAI—1、TIMP—1表达明显降低，MMP—1表达明显升高。结论：肾络宁可明显减轻IgA肾病大鼠肾小管间质损害，改善肾功能，延缓间质纤维化及肾衰竭的进程。     

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.     

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.     

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.     

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.     

Synergistic interaction between the effects of propofol and midazolam with fentanyl on phrenic nerve activity in rabbits

Background: It has been shown that the depressive effects of both propofol and midazolam on consciousness are synergistic with opioids, but the nature of their interactions on other physiological systems, e. g. respiration, has not been fully investigated. The present study examined the effect of propofol and midazolam alone and in combination with fentanyl on phrenic nerve activity (PNA) and whether such interactions are additive or synergistic. Methods: PNA was recorded in 27 anaesthetised and artificially ventilated rabbits. In three groups, propofol, fentanyl and midazolam were administered intravenously in incremental doses to construct dose-response curves for the depressant effects of each one on PNA. In another two groups, the effect of pretreatment with either fentanyl 1 μg · kg^?1 i. v. or midazolam 0.05 mg · kg^?1 i. v. on the effects of propofol and fentanyl respectively on PNA were studied. Results: Propofol and fentanyl caused a dose-dependent depression of PNA with complete abolition at the highest total doses of 16 mg · kg^?1 i. v. and 32 μg · kg^?1 i. v., respectively. In contrast, midazolam in incremental doses to a total of 0.8 mg · kg^?1 reduced mean PNA by 63%, but approximately 12% of PNA remained at a total dose as high as 6.4 mg · kg^?1. The mean ED₅₀s, calculated from dose-response curves, were 5.4 mg · kg^?1, 3.9 μg · kg^?1 and 0.4 mg · kg^?1 for propofol, fentanyl and midazolam, respectively. Initial doses of either fentanyl 1 μg · kg^?1 i. v. or midazolam 0.05 mg · kg^?1 i. v. acted synergistically with subsequent doses of either propofol or fentanyl to abolish PNA at total doses of 8 mg · kg^?1 and 8 μg · kg^?1, respectively. Conclusion: Fentanyl has a synergistic interaction with both propofol and midazolam on PNA and hence potentially on respiration.     

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.     

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.     

Systemic analgesia adapted to the children's condition

A concept of balanced analgesia using nonsteroidal anti-inflammatory drugs (NSAIDs), paracetamol (acetaminophen), opioids, and corticosteroids can also be used in patients with pre-existing illnesses. NSAIDs are the most effective treatment for acute pain of moderate intensity in children; however, these drugs should be avoided in patients at increased risk for serious side effects, e.g. patients with renal impairment, bleeding tendency, or extreme prematurity. NSAIDs can be given with minimal risks to the younger child with mild to moderate asthma, and, in these patients, the use of steroids can be encouraged; in addition to their antiemetic and analgesic action, a beneficial effect on asthma symptoms can be expected. In the non-intubated child with cerebral trauma, exaggerated sedation caused by opioids and increased bleeding tendency caused by NSAIDs must be avoided. In neonates and small infants, the oral administration of sucrose or glucose is helpful to minimize pain reaction during short uncomfortable interventions.