IL-6对人精子顶体反应影响机制的初步探讨

目的:探讨IL-6对人精子顶体反应(AR)的影响机制。方法:采用BAEE/ADH法测定精子顶体酶的活性,以及通过FITC-PSA法检测精子顶体反应。结果:IL-6可诱导精子顶体酶及超氧化物歧化酶(SOD)的活性,促进精子顶体反应;胞外Ca2+单独不能诱导精子顶体反应,且没有胞外Ca2+的参与,IL-6也不能诱导精子顶体反应;蛋白激酶C(PKC)抑制剂calphC能逆转IL-6诱导的精子顶体反应。结论:IL-6对精子顶体反应有一定的促进作用,可能通过诱导精子的顶体酶和SOD活性等途径来实现,在此作用中,也涉及了PKC的激活,且还需要外源性Ca2+的参与。     

肿瘤坏死因子对人精子顶体酶和顶体反应的影响及机制探讨

目的 研究肿瘤坏死因子(TNF-α)对正常精子顶体酶活性和顶体反应的影响及其机制。方法采用BAEE/ADH联合法测定顶体酶和三色染色法技术测定顶体反应。结果 TNF-α可显著降低精子顶体酶的活性和顶体反应(P<0.01;P<0.01),并且它可使精子中的Ca2+-ATPase和SOD的活性显著降低(P<0.05;P<0.001);但TNF-α可使精子中NOS活性增强及NO含量增加(P<0.001;P<0.001);对Na+-K+-ATPase活性影响不明显(P>0.05)。结论 TNF-α对精子顶体酶及顶体反应有一定的抑制作用,并且可能通过降低Ca+-ATPase活性,自由基和NO及增加NOS等多种途径来实现的。     

精子诱发顶体反应与精子顶体酶活性测定关系的研究

目的 通过对精液常规正常的不育男子检测人类精子诱发顶体反应和测定精子顶体酶活性,探讨两种检测结果 的相关性.方法 40例精子密度≥20×106/ml、活动力(a+b)级精子≥50%的不育男子精液,采用离子载体A23187诱导精子顶体反应(AR),用FITC-PSA荧光染色法分析AR,并计算顶体反应发生率;用分光光度比色法(Kennedy法)测定精子顶体酶活性.用组间方差分析方法 比较精子顶体反应发生率与精子顶体酶活性之间关系.结果 两种检测结果 没有明显相关性(r=0.292,P>0.05).结论 两种检测联合应用可作为临床分析男性不育病因的检测手段.     

干扰素-γ和肿瘤坏死因子-α对精子受精能力的影响及机制初探

目的:观察IFN-γ和TNF-α对正常精子顶体酶活性和顶体反应率的影响,并对其变化机制进行初步探讨。方法:36例精液常规分析基本正常标本,经75%Percoll分离后,分别或联合使用IFN-γ和TNF-α处理(终浓度均为30ng/ml)。采用BAEE/ADH联合法测定精子顶体酶活力的变化。用三色染色法观察精子顶体反应率的变化。用高效液相色谱法(HPLC)检测精子NO含量。用试剂盒法测定Na+-K+-ATPase、Ca2+-ATPase和SOD活性。结果:IFN-γ和TNF-α单独及联合使用时,均可显著降低精子顶体酶活性和顶体反应率(P<0.05或P<0.01),且TNF-α的抑制作用更强些;IFN-γ可使精子Na+-K+-ATPase、Ca2+-ATPase和SOD活性显著降低(P<0.01),且两者协同作用更低,但TNF-α对Na+-K+-ATPase和Ca2+-ATPase活性几乎无作用;IFN-γ、TNF-α及两者合用时均使精子NO含量显著增加(P<0.01)。结论:IFN-γ和TNF-α对精子顶体酶活性及顶体反应率有一定的抑制作用,并且可能通过对精子Na+-K+-ATPase、Ca2+-ATPase、SOD活性以及NO含量等多方面影响来实现的。     

低氧对大鼠精子体外顶体反应和顶体酶、透明质酸酶活性的影响

目的研究低氧对大鼠精子顶体酶、透明质酸酶活性的影响以及对精子体外顶体反应发生的影响。方法成年Wistar大鼠随机分为4个组:常氧对照组、低氧5d组、低氧15d组和低氧30d组。低氧组置低压舱内模拟高原5000m,分别低氧5、15和30d。采用明胶薄膜法、透明质酸底物转化法、溶血磷脂胆碱(LPC)诱导金霉素荧光染色法,测定低氧对附睾尾精子顶体酶、透明质酸酶活性和体外顶体反应发生率的影响。结果低氧5、15和30d组大鼠精子顶体反应发生率,与常氧对照组相比均显著降低,分别由常氧对照组的(30.5±3.5)%,下降至(11.7±0.9)%(P<0.01)、(10.8±1.0)%(P<0.01)和(10.0±1.4)%(P<0.01);低氧5、15和30d组大鼠精子顶体酶阳性率降低,分别由常氧对照组的(81.67±7.16)%,下降至(54.17±3.82)%(P<0.01)、(30.00±3.92)%(P<0.01)和(43.00±3.63)%(P<0.01);低氧各组透明质酸酶活性无显著改变(P>0.05)。结论低氧抑制了精子顶体酶活性和顶体反应发生。     

硝普钠对冷冻复温人精子顶体反应的影响

本文目的是研究复温温度和硝普钠(SNP)对冷冻精子复温后成活率和顶体反应的影响和机制，结果表明：对冻融精子37℃水浴复温效果优于41℃，高浓度SNP可减少精子成活率和顶体反应率，低浓度(0.2nmol/L)可促进精子成活率和顶体反应率，低浓度SNP可使Na+-K+-ATP酶活性增加，而对丙二醛(MDA)无影响     

硝普钠对人精子获能及顶体反应的影响

目的:探讨一氧化氮(NO)对人精子获能及顶体反应(AR)的影响。方法:在48例健康生育男性的精子悬液中加入不同浓度的NO供体硝普钠(SNP),于37℃孵育1h获能,用孕酮诱导AR15、30、45、60min,采用磷酸苯二钠法分别检测精子获能前后及AR各时间点的精子悬液上清中酸性磷酸酶(ACP),同时用计算机辅助精液分析系统(CASA)分析精子运动参数,观察NO对精子获能及AR的作用。结果:NO浓度在50、100nmol/L时精子悬液中ACP活性增高,精子运动参数明显增强,150、200nmol/L时ACP活性及精子运动参数变化不大,250、300nmol/L时精子悬液中ACP活性和精子运动参数明显降低。结论:NO对精子获能和AR具有双重性,在低浓度下有促进精子获能、AR和精子运动参数增强的作用,而在高浓度下对精子获能、AR和精子运动参数有抑制作用。精子ACP检测对精子群体获能和AR状态的评价是种较为客观、可靠的方法。     

60KD、78KD精子膜抗原的抗体对精子的影响

目的：研究抗精子抗体对精子功能的影响。方法：使用抗60KD阳性血清及抗精子抗体阴性血清体外处理精子，比较它们对精子的凝集、细胞毒、穿透高度和顶体反应的影响。结果：抗60KD和抗78KD精子膜抗原的抗体都能对精子产生凝集作用和补体依赖的细胞毒作用，及降低精子的穿透高度，其中抗60KD精子膜抗原的抗体还能明显抑制精子的顶体酶活性。结论：抗精子抗体可通过对精子产生凝集作用和细胞毒作用，以及影响精子的穿透能力和顶体反应来降低精子的生育能力，60KD的精子膜抗原可能和精子的顶体反应有关。     

硝普钢地冷冻复温人精子顶体反应的影响

本文目的是研究复温温度和硝普钠（SNP）对冷冻精子复温后成活率和顶体反应的影响和机制,结果表明：对冷冻精子37℃水浴复温效果优于41℃,高浓度SNP可减少精子成活率和顶体反应率,低浓度(0.2nmol/L)可促进精子成活率和顶体反应率,低浓度SNP可使Na^ -K^ -ATP酶活性增加,而对丙二醛（MDA）无影响。     

一氧化氮对精子功能的影响

一氧化氮 (NO)是一种具有广泛生物学活性的信使分子和细胞毒性因子。近年研究表明 ,NO对哺乳动物的生殖活动具有重要的调节作用。NO参与精子发生、获能并影响精子质量。低浓度NO具有保护精子活力 ,促进精子获能的作用 ;而高浓度NO则损害生精功能 ,抑制精子活动度及降低顶体反应率。NO与氧自由基相互作用 ,共同参与精子功能的调节。     

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.     

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.     

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.     

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.