性激素及甲状旁腺激素与老年男性骨转换生化指标的相关性分析

目的:探讨老年男性血清性激素及甲状旁腺激素与骨转换生化指标的相关性。方法:收集2011年5~6月在我院常规年度体检年龄≥60岁的老年男性465例,年龄60~93岁。测定血清卵泡刺激素(FSH)、黄体生成素(LH)、雌二醇(E2)、睾酮(T)、性激素结合球蛋白(SHBG);血清甲状旁腺激素(PTH)、25-羟化维生素D3(25(OH)D3);骨转换生化指标(I型胶原羧基末端肽:CTX;骨钙素:OC;Ⅰ型前胶原氨基末端前肽:PINP);并计算游离睾酮(FT)、生物可利用睾酮(BT)、睾酮分泌指数(TSI)和游离睾酮指数(FTI);分析各指标与老年男性骨转换生化指标的相关性。结果:老年男性血清FSH、LH、SHBG水平随年龄增加而升高,而FT、BT、TSI、FTI、PTH及CTX、OC和PINP随增龄呈下降趋势,80岁以后下降较为显著(P0.05)。PTH与CTX、OC和PINP均呈正相关(r=0.227,0.269,0.162;P0.01),校正年龄因素后,相关性仍然存在;SHBG与OC负相关(r=-0.100,P0.05)。各骨转换指标随PTH四分位水平升高而增加,第一分位与第四分位之间均存在显著差异(P0.01)。多元逐步回归结果显示,年龄与CTX、OC和PINP负相关(β=-0.126,-0.141,-0.122;P0.05),PTH与CTX、OC和PINP正相关(β=0.196,0.279,0.189;P0.001),SHBG与OC负相关(β=-0.100,P0.05)。结论:增龄是老年男性骨转换减低的根本原因,血清PTH和SHBG水平与骨转换生化指标相关。     

绝经后2型糖尿病患者骨硬化蛋白、PINP、CTX与骨密度相关性研究

目的比较绝经后2型糖尿病患者骨质疏松组、低骨量组、骨量正常组血清骨硬化蛋白(sclerostin,SO)水平,探讨SO与Ⅰ型前胶原氨基末端(N端)前肽(procollagen typeⅠN-terminal propetide,PINP)、Ⅰ型胶原C端肽(typeⅠcollagen carboxyterminal peptide,CTX)、骨密度(bone mineral density,BMD)的关系。方法比较绝经后2型糖尿病患者骨质疏松症组、低骨量组、骨量正常组3组间年龄、绝经年限、糖尿病病程、体重指数、股骨颈及平均腰椎BMD、空腹血糖、糖化血红蛋白、25-(OH)D3、SO、PINP、CTX各指标的差异,并做SO与上述指标的单因素相关性分析和多元线性回归分析。结果 (1)骨质疏松症组年龄、绝经年限显著高于低骨量组、骨量正常组(P均=0.000),低骨量组明显高于骨量正常组(P=0.009、0.002);(2)绝经后2型糖尿病患者中25-(OH)D3缺乏113例(90.4%);(3)骨质疏松症组SO、PINP水平显著高于低骨量组、骨量正常组(P=0.000),低骨量组SO水平明显高于骨量正常组(P=0.045);(4)SO与PINP、年龄、绝经年限正相关(r=0.978、0.194、0.205),与股骨颈BMD、平均腰椎BMD、体重指数负相关(r=-0.518、-0.349、-0.249),多元线性回归分析显示SO与PINP呈正相关(β=7.015,P=0.000)、与股骨颈BMD呈负相关(β=-11.245,P=0.023)。结论 (1)绝经后2型糖尿病合并骨质疏松者SO水平明显增高,与PINP水平呈显著正相关,与股骨颈BMD呈显著负相关;(2)25(OH)D3在绝经后2型糖尿病患者中普遍缺乏。     

胰岛素样生长因子与血液透析患者骨质疏松症关系的研究

目的：探讨血胰岛素样生长因子-1（IGF-1）与血液透析患者骨密度的关系及其在骨质疏松症诊断中的作用。方法：45例骨量异常（骨量减少或骨质疏松）血液透析患者分别检测透析前血IGF-1、Ⅰ型前胶原氨基端前肽（PINP）、Ⅰ型胶原C末端肽（CTX）等生化指标,统计所有患者的骨密度值。15例骨量正常血液透析患者作为对照组。结果：透析患者骨量异常组血IGF-1水平显著低于骨量正常对照组（P〈0.001）,而且早在骨量减少阶段就已显示出差异性（P〈0.05）,血PINP、CTX显著高于骨量正常对照组（P〈0.001）。血清IGF-1水平与患者髋部的骨密度正相关（P〈0.001）,与PINP、CTX负相关（P〈0.001）,但与腰椎骨密度值无相关性。结论：IGF-1做为新型骨代谢生化标志物,其水平在血液透析患者中与骨密度变化相平行,对透析患者骨量变化的监测和骨质疏松症的早期诊断具有重要的临床价值。     

血清雌二醇和游离睾酮与老年男性骨密度的相关性

目的探讨老年男性血清雌二醇(E2)和游离睾酮(FT)与骨密度(BMD)的关系。方法采用双能X线法检测192例老年男性骨密度,根据其骨密度值分为骨量正常组、骨量减少组和骨质疏松组;免疫放射法检测血清E2、睾酮(T)、FT、性激素结合球蛋白(SHBG)、脱氢表雄酮硫酸酯(DHEAS)水平。比较各组间激素的差异及分析激素与骨密度的关系。结果 3组间E2、FT水平存在明显差异(P0.05);经年龄、体质量和BMI校正后,E2与各部位BMD正相关,FT与各部位(腰椎和华氏三角除外)BMD正相关;E2四分位BMD,在第1和第4间距差异有统计学意义(P0.05),在第1、2之间,3、4之间无差异(P0.05)。结论血清E2、FT水平与老年男性骨密度呈正相关;E2对骨密度的影响存在阈值,检测血清E2、FT水平可预防老年男性的骨量丢失。     

骨代谢标志物在宁波地区绝经后女性骨质疏松症患者中的临床应用

目的 研究骨代谢标志物在宁波地区绝经后中老年女性骨质疏松症患者诊疗中的作用。方法 随机选择绝经后的中老年女性受试者264例,年龄均大于50岁,根据骨密度结果将264例检测对象根据骨密度大小分为骨量正常组82例,骨量减少组90例,骨质疏松组92例,同时采用电化学发光免疫分析方法测定受检对象血清中β-CTX、PINP、25-OHD3水平,并进行对比分析。结果 骨质疏松组：β-CTX水平与正常对照组、骨量减少组比较差异有统计学意义（P <0.05) ;PINP、25-OHD3水平在3组间差异无统计学意义（P>0.05)。结论骨质疏松症患者血清骨代谢标志物水平与骨质疏松存在密切的相关性;β- CTX是骨质疏松症诊断和疗效评估的理想指标;PINP、25-OHD3是骨质疏松症诊断和治疗的参考指标。     

骨质疏松症患者骨密度与血清25羟维生素D的相关性研究

目的分析骨质疏松症患者骨密度与血清25羟维生素D的相关性。方法记录397例50~97岁患者的年龄,检测腰椎1~4、左侧股骨颈、左侧股骨上端的骨密度(bone mineral density,BMD),检测骨质疏松4项[甲状旁腺素(parathyroid hormone,PTH)、总I型胶原氨基端前肽(procollagen type 1 amino-terminal propeptide,P1NP)、β胶原降解产物(beta collagen degradation products,β-CTX)、N端骨钙素(N end of osteocalcin,N-MID)]及血清25羟维生素D[25-(OH)D]的水平,根据BMD水平将受试者分为骨量正常组(n=118)、骨量低下组(n=153)和骨质疏松组(n=126)。结果 (1)骨量低下组及骨质疏松组的BMD均明显低于正常骨量组(P0.01),骨质疏松组又明显低于骨量低下组(P0.01);(2)骨质疏松组25-(OH)D、PTH、P1NP、β-Crosslaps及N-CTX均明显低于正常骨量组(P0.01);(3)25-(OH)D与腰椎1~4、左侧股骨颈、左侧股骨上端的BMD、PTH、P1NP、β-CTX无相关性(P0.05),25-(OH)D与N-MID的相关系数为0.193(P0.01)。不同骨密度组间的25-(OH)D差异无统计学意义(P0.05)。结论老年人群普遍存在维生素D(vitamin D,VD)水平不足的现象,而骨质疏松症患者更为突出,其中VD严重缺乏和缺乏所占比例较大,为骨质疏松症的防治提供一定的数据参考,应注意加强宣教及防治。尚未发现25-(OH)D与骨密度之间存在着直接相关关系。     

低骨量与老年钙化性心脏瓣膜病的相关研究

目的评价老年人心脏瓣膜钙化和骨量情况,探讨低骨量与老年钙化性心脏瓣膜病(senile calcified valvulardisease,SCVD)的关系。方法连续收集2011年1月至2013年5月期间在新疆医科大学第一附属医院干部病房住院的患者,年龄≥60岁,符合纳入标准,共353例,其中男性215例,平均年龄(72.09±7.73)岁,女性138例,平均年龄(69.54±6.59)岁。应用超声心动图观察其心脏瓣膜情况,根据老年钙化性心脏瓣膜病诊断标准,将其分为SCVD组(男性57例,女性47例),非SCVD组(男性158例;女性91例);同时所有研究对象均行双能X线骨密度测定,评估腰椎、全髋关节、股骨颈骨量情况。结果(1)SCVD组和非SCVD组低骨量总人数比较,差异有统计学意义(χ2=4.315,P0.05)。但无论在男性还是女性,两组间比较,差异无统计学意义(P0.05)。(2)SCVD组低骨量患者全髋关节骨密度较非SCVD组降低,差异有统计学意义(t值:2.455,P0.05),两组间股骨颈T值比较,差异有统计学意义(t值:2.051,P0.05),两组间全髋关节T值比较,差异有统计学意义(t值:3.066,P0.05),两组间最低T值比较,差异有统计学意义(t值:3.218,P0.05)。(3)未发现男性SCVD组和非SCVD组腰椎、全髋关节、股骨颈骨密度及T值比较,差异有统计学意义(P0.05),但两组间最低T值比较,差异有统计学意义(t值:2.354,P0.05)。(4)女性SCVD组和非SCVD组全髋关节T值比较,差异有统计学意义(t值:2.452,P0.05),两组间最低T值比较,差异有统计学意义(t值:2.352,P0.05)。(5)经logistic回归分析后,无论男性还是女性,SCVD组与非SCVD组年龄比较均存在显著差异,有统计学意义(男性OR:1.061,95%CI:1.019~1.105,P0.05,女性OR:1.077,95%CI:1.017~1.139,P0.05),年龄与老年钙化性心脏瓣膜病发生风险独立相关,未发现性别、体重指数、高血压、高脂血症、糖尿病、冠心病、低骨量与老年钙化性心脏瓣膜病发生风险相关。(6)经logistic回归分析后,女性最低T值在SCVD组与非SCVD组存在差异,有统计学意义(OR:0.645,95%CI:0.441~0.945,P0.05)。结论 (1)年龄是SCVD发生的独立危险因素之一。(2)女性SCVD患者需行骨密度测定,尤其是全髋关节部位,来评估骨量情况。(3)女性最低T值与SCVD发病相关,推测女性低骨量可能是使老年钙化性心脏瓣膜病发生风险增加的独立因素。女性低骨量患者需进一步评估瓣膜情况及相关心血管疾病。     

老年男性骨质疏松与同型半胱氨酸、甲状旁腺素、睾酮水平的相关研究

目的探讨老年男性骨质疏松与血清同型半胱氨酸、甲状旁腺素、睾酮是否具有相关性。方法选择60岁以上老年男性148例。采用美国数字化双能X线骨密度仪测定其腰椎及股骨颈部位的骨密度值,并根据骨密度水平分为三组,为骨质疏松组(T-2.5)、骨量减少组(-2.5T-1.0),正常骨量组(T-1.0),检测血清同型半胱氨酸、甲状旁腺素及睾酮水平。结果骨质疏松组血清同型半胱氨酸、甲状旁腺素水平明显高于骨量减少组(P0.05)及正常骨量组(P0.01),而睾酮水平明显低于骨量减少组(P0.05)及正常骨量组(P0.01)。血清同型半胱氨酸、甲状旁腺素水平与骨密度值呈正相关,睾酮与骨密度值呈负相关。结论血清同型半胱氨酸、甲状旁腺素水平升高及睾酮水平下降可造成骨量减少和骨形成障碍,最终导致骨质疏松形成。高同型半胱氨酸是骨质疏松的一个独立危险因素。因此监测血清同型半胱氨酸、甲状旁腺素、睾酮水平对早期发现骨质疏松并阻止其进一步发生发展起着重要作用,降低高同型半胱氨酸、调节甲状旁腺素水平,增加睾酮水平可能成为骨质疏松治疗中的一种新方法之一。     

老年男性骨密度与身体成分相关性的研究

目的分析老年男性骨密度(bone mineral density,BMD)与身体成分的关系。方法记录166名80~94岁老年男性的年龄、身高、体重、BMI,检测L1-4、左侧股骨颈、Wards三角、大粗隆、左侧股骨上端的BMD及总肌肉含量(total lean mass,TLM)和总脂肪含量(total fat mass,TFM),根据BMD水平将受试者分为骨量正常组(n=50)、骨量低下组(n=91)和骨质疏松组(n=25)。结果 (1)骨量低下组及骨质疏松组的BMD均明显低于正常骨量组(P0.01),骨质疏松组又明显低于骨量低下组(P0.01);(2)骨质疏松组体重、TLM、TFM及BMI均明显低于正常骨量组(P0.01);(3)TLM与左侧股骨颈、Wards三角、左侧股骨上端的BMD相关系数分别为0.227、0.203及0.193(P0.05),TFM与腰椎1-4、左侧股骨颈、Wards三角、大粗隆、左侧股骨上端的BMD相关系数为0.269、0.222、0.206、0.246及0.242(P0.01)。结论大部分老年男性BMD与年龄呈显著负相关;与体重、BMI及TFM、TLM呈显著正相关,适当的运动和适度的肥胖,增强肌肉量和维持一定的脂肪量,保持健康的体重,可能有利于预防老年性骨质疏松症。     

红景天甙联合碳酸钙对老年雌性大鼠骨量、骨代谢和氧化应激水平影响

目的探索红景天甙联合碳酸钙对老年雌性大鼠骨量、骨代谢和氧化应激水平影响。方法将40只24月龄雌性Sprague-Dawley(SD)大鼠随机分为模型组(OP组),红景天甙组(H组),碳酸钙组(Ca组)和红景天甙联合碳酸钙组(H+Ca组),而将10只3个月大鼠作为对照组(NC组)。观察各组大鼠腰椎和双侧股骨骨密度和骨矿物质水平的变化。测定各组大鼠骨代谢指标、超氧化物歧化酶(SOD)、丙二醛(MDA)和谷胱甘肽过氧化物酶(GSH-Px)水平变化。结果与OP组比较,H、Ca和H+Ca组大鼠腰椎骨密度,双侧股骨骨密度和骨矿物质水平显著升高;治疗12周,H、Ca和H+Ca组血清I型胶原C端肽(CTX-1)、骨钙素、碱性磷酸酶(ALP)、I型前胶原N端肽(PINP)和抗酒石酸酸性磷酸酶5b(TRACP-5b)水平均显著降低,比较差异有统计学意义(P 0.05);治疗12周,H、Ca和H+Ca组血清SOD和GSH-Px活性明显升高,MDA含量显著降低,差异有统计学意义(P 0.05或P0.01);其中H+Ca组上述指标变化最为显著;差异有统计学意义(P 0.05)。结论红景天甙联合碳酸钙可显著提高老年大鼠的抗氧化能力,增加骨密度,降低骨代谢水平,减少骨矿物质流失,从而预防和治疗骨质疏松症。     

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.     

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.     

Immunomodulation in Transplantation with Photopheresis

Abstract: Photopheresis is a technique in which peripheral blood mononuclear cells, in the presence of a photoacti-vatable compound, are exposed extracorporeally to ultraviolet A light and reinfused, inducing a host autoregula-tory immune response. Experimental work and ongoing clinical studies are helping to define the role of this novel, safe, and non-toxic immunomodulating technology in the field of transplantation.