基于MRI自动化定量海马体积诊断颞叶癫痫患者海马硬化

目的 评估基于MRI自动化定量海马体积诊断颞叶癫痫患者海马硬化（HS）的效能。方法 回顾性分析经术后病理检查证实的64例存在HS的颞叶癫痫患者,采用AccuBrain软件对头部3D T1WI进行自动化定量分析,检测海马体积指数（HVI）;以病理结果为诊断金标准,统计2名医师目测诊断HS结果。采用受试者工作特征（ROC）曲线获得HVI诊断HS的截断值及曲线下面积（AUC）,计算HVI诊断HS的敏感度、特异度和准确率,评价2种诊断方式所获结果的一致性。结果 64例中,38例左侧HS、26例右侧HS。医师目测诊断HS的敏感度、特异度、准确率分别为90.63%（58/64）、100%（64/64）及95.31%（122/128）。ROC曲线结果显示,HVI诊断HS的最佳截断值为0.185,AUC为0.936。HVI诊断HS的敏感度、特异度、准确率分别为87.50%（56/64）、93.75%（60/64）及90.63%（116/128）。医师目测与HVI诊断HS的准确率一致性较强（Kappa=0.684,P<0.05）。结论 MRI自动化定量海马体积可用于诊断颞叶癫痫患者HS,其诊断效能较高。     

动态增强MRI定性诊断乳腺导管上皮非典型增生

目的 观察动态增强MRI（DCE-MRI）定性诊断乳腺导管上皮非典型增生（ADH）的价值。方法 回顾性分析经穿刺活检或局部切除组织活检诊断的64例乳腺单发ADH患者,以手术病理结果为金标准,比较恶性与良性病变患者临床资料及乳腺X线、DCE-MRI征象,分析DCE-MRI预测乳腺恶性ADH的效能。结果 64例乳腺单发ADH中,28例为恶性（恶性组）,36例非恶性（非恶性组）,组间活检方式、病灶最大径、MRI示乳腺实质背景强化（BPE）、乳腺X线表现差异均有统计学意义（P均<0.1）;将上述因素纳入Logistic多因素回归分析,结果显示仅BPE为乳腺恶性ADH的独立影响因素[OR=7.550,95%CI（1.575,36.197）,P=0.011]。DCE-MRI诊断BI-RADS 4A及以下者27例,其中3例为恶性;4A类以上（4B及4C）37例,25例为恶性,诊断敏感度89.29%（25/28）,特异度66.67%（24/36）,阳性预测值67.57%（25/37）,阴性预测值88.89%（24/27）。结论 DCE-MRI可用于定性诊断乳腺ADH;其所示中重度BPE为术后病理恶性的正相关因素。     

弥散加权成像联合动态增强MRI预测肝细胞癌经TACE联合射频消融治疗后复发

目的 观察弥散加权成像（DWI）联合动态增强MRI预测肝细胞癌（HCC）经TACE联合射频消融治疗后复发的价值。方法 回顾性分析80例接受TACE联合射频消融治疗的HCC患者,均于治疗前10天和治疗后20、60及90天接受腹部DWI及动态增强MR检查;计算DWI联合动态增强MRI预测TACE联合射频消融治疗后20天HCC复发的敏感度、特异度及准确率;绘制受试者工作特征（ROC）曲线,评估以表观弥散系数（ADC）值预测TACE联合射频消融治疗后20天HCC复发的效能。结果 参照改良实体瘤疗效评价标准,将47例HCC患者纳入稳定组、33例归为进展组。TACE联合射频消融治疗后20天,稳定组HCC病灶DWI多呈不均匀信号、ADC图呈高信号、增强扫描未见强化,进展组病灶多呈DWI高信号、ADC图低信号、增强扫描轻度强化。DWI联合动态增强MRI预测TACE联合射频消融治疗后20天HCC复发的敏感度、特异度及准确率分别为97.75%（87/89）、92.31%（24/26）及96.52%（111/115）。以ADC值预测TACE联合射频消融治疗后20天HCC复发的曲线下面积为0.82;以ADC=1.42×10^-3 mm²/s为截断值,预测的敏感度及特异度分别为72.13%及82.25%。结论 DWI联合动态增强MRI用于预测TACE联合射频消融治疗后HCC复发具有一定价值;ADC值可作为有效预测指标。     

细针穿刺细胞学检查与粗针穿刺活检术对甲状腺结节的诊断效能比较

背景与目的 彩超引导下细针穿刺细胞学检查（FNAC）是术前评估甲状腺结节良恶性的主要方法,其缺点是取材不足,可能导致误诊或漏诊。粗针穿刺活检术（CNB）可弥补FNAC的不足,但其缺点是增加了疼痛和创伤。因此,本研究比较FNAC与CNB对甲状腺结节诊断的诊断效能及各自特点,以期为临床合理选择提供参考。方法 回顾性分析2020年11月—2022年11月于武汉大学中南医院接受甲状腺手术的552例患者资料,所有患者术前均接受超声检查,并依次行FNAC与CNB,穿刺1周内行患侧甲状腺切除术。收集患者临床资料及甲状腺结节的超声特征、术前细胞学、组织病理学及术后常规病理结果,以术后常规病理为金标准,分析FNAC及CNB诊断效能。结果 总体上,FNAC与CNB对甲状腺结节诊断敏感度、特异度、准确率相近,差异均无统计学意义（88.7% vs. 91.4%,P=0.283;90.6% vs. 97.4%,P=0.226;85.3% vs. 89.1%,P=0.058）;对滤泡性肿瘤的良恶性判别,CNB优于FNAC（P=0.024）。当结节直径≤2.0 cm时,FNAC与CNB诊断效能基本无差异;当结节直径>2.0 cm时,CNB的敏感度明显高于FNAC（95.0% vs. 79.2%,P<0.001）,联合二者诊断可进一步提高敏感度至99.2%。对于钙化结节、囊性变结节、富血供结节的诊断,CNB的敏感度与准确率均高于FNAC（91.0% vs. 88.7%、91.0% vs. 84.8%、92.8% vs. 85.1%;93.2% vs. 88.8%、91.7% vs. 84.8%、93.3% vs. 85.2%）,除对钙化结节的差异无统计学意义外,其余差异均有统计学意义（均P<0.05）;对于缺乏血供结节的诊断,FNAC的敏感度与准确率均高于CNB（92.7% vs. 90.2%,P=0.004;96.2% vs. 90.5%,P=0.005）。结论 CNB与FNAC对直径≤2.0 cm的甲状腺结节的诊断效能相当,但CNB在滤泡性肿瘤的判别方面有一定优势。CNB对直径>2.0 cm、钙化结节、富血供及囊性或囊实性结节甲状腺结节诊断效能优于FNAC,对具备上述特征的结节联合FNAC与CNB检查可在一定程度上提高甲状腺结节术前诊断的准确率。     

超声多普勒血流速度诊断肾动脉支架植入术后支架内再狭窄

目的 分析超声多普勒血流速度诊断支架植入术治疗重度粥样硬化性肾动脉狭窄（ARAS）术后支架内再狭窄的价值。方法 回顾性分析85例（94条肾动脉）肾动脉支架植入术后重度ARAS患者，根据术后12个月超声造影（CEUS）所示支架内径狭窄比判定狭窄程度，以<30%为无再狭窄，30%~50%为轻度再狭窄，51%~70%为中度再狭窄，>70%为重度再狭窄；对比其支架内收缩期峰值血流速度（PSV）及肾动脉PSV与腹主动脉PSV比值（RAR）。采用受试者工作特征（ROC）曲线分析PSV、RAR对支架内再狭窄的诊断价值。结果 94条植入支架后肾动脉中，术后12个月2条支架闭塞。92条未闭塞动脉中，58条无再狭窄，15条轻度再狭窄，11条中度再狭窄，8条重度再狭窄。不同程度再狭窄肾动脉支架内PSV及RAR差异均有统计学意义（P均<0.01），且PSV、RAR随狭窄程度增高而逐渐加大（P均<0.05）。以PSV>162.50 cm/s作为判断支架内径狭窄比>30%的阈值，其敏感度、特异度均为100%；以RAR>2.28作为阈值，敏感度为100%，特异度为96.60%。对于支架内径狭窄比>50%，以PSV>219.55 cm/s作为诊断阈值，其敏感度为100%，特异度为98.60%；以RAR>3.17作为阈值，敏感度为100%，特异度为94.50%。以PSV>310.53 cm/s作为支架内径狭窄比>70%的诊断阈值，敏感度为100%，特异度为100%；以RAR>4.33作为阈值，敏感度为100%，特异度为100%。结论 超声多普勒血流速度对于诊断肾动脉支架植入术治疗重度ARAS术后支架内再狭窄的效能较高。     

2017年美国放射学会甲状腺影像报告与数据系统鉴别甲状腺良恶性结节

目的 探讨2017年美国放射学会（ACR）推荐的甲状腺影像报告与数据系统（TI-RADS）对鉴别甲状腺良恶性结节的应用价值。方法 回顾性分析经手术病理确诊的497个甲状腺结节的超声资料,采用2017年ACR TI-RADS分类对结节评分和分类,与病理结果对照,采用ROC确定最佳临界评分,计算TI-RADS分类诊断良恶性结节的敏感度、特异度和准确率。评价高年资与低年资医师采用此最佳临界评分诊断甲状腺良恶性结节的效能和一致性。结果 采用2017年ACR TI-RADS分类诊断甲状腺恶性结节的ROC曲线下面积为0.883（P<0.001）,最佳临界评分为5分,敏感度86.22%,特异度78.68%。以TI-RADS评分> 5分归为恶性结节,高年资和低年资医师诊断的敏感度、特异度、准确率分别为78.22%（176/225）、76.47%（208/272）、77.26%（384/497）和77.33%（174/225）、74.26%（202/272）、75.65%（376/497）,二者诊断良恶性结节具有中等一致性（Kappa=0.581）。结论 2017年ACR TI-RADS具有较高临床应用价值,鉴别甲状腺良恶性结节的最佳界值为5分。     

术前盆腔对比增强MRI评估子宫内膜癌子宫肌层浸润程度

目的 探讨术前盆腔对比增强MRI对子宫内膜癌子宫肌层浸润程度的诊断价值。方法 回顾性分析89例经手术病理确诊的子宫内膜癌患者,术前均以盆腔对比增强MRI评估肌层浸润程度,并与术后病理结果进行比较,评价术前对比增强MRI对子宫内膜癌肌层浸润程度的诊断效能。结果 术前盆腔MRI示病变区子宫内膜均呈不均匀中-高信号强度,子宫肌层内边缘不清,结合带中断,受累肌壁呈不均匀高信号。术前对比增强MRI诊断62例浅肌层浸润,27例深肌层浸润;术后病理诊断浅肌层浸润63例,深肌层浸润26例。术前对比增强MRI诊断浅肌层浸润的敏感度90.48%（57/63）,特异度80.77%（21/26）,阳性预测值91.94%（57/62）,阴性预测值77.78%（21/27）,准确率87.64%（78/89）;诊断深肌层浸润敏感度80.77%（21/26）,特异度90.48%（57/63）,阳性预测值77.78%（21/27）,阴性预测值91.94%（57/62）,准确率87.64%（78/89）。结论 术前盆腔对比增强MRI评估子宫内膜癌子宫肌层浸润程度的效能较高。     

CT引导下经皮微波消融治疗老年患者周围型非小细胞肺癌

目的 观察CT引导下经皮微波消融治疗（PMCT）对老年周围型非小细胞肺癌（NSCLC）患者的有效性及安全性。方法 回顾性分析接受CT引导下PMCT治疗的34例老年周围型NSCLC患者,其中肿瘤直径≤3 cm（小病灶）16例,3 cm<直径≤5 cm（中病灶）11例,>5 cm（大病灶）7例。术后随访,分别于3、6、12、24个月采用改良实体瘤疗效评价标准（mRECIST）评估疗效,并统计生存率。结果 对34例患者的34个肺内病灶均消融完全,术中及术后均未见严重并发症。术后3、6、12及24个月累计疾病控制率（DCR）分别为100%（34/34）、97.06%（33/34）、91.18%（31/34）及85.29%（29/34）;术后6、12及24个月生存率分别为100%（34/34）、94.12%（32/34）及85.29%（29/34）。术后24个月,小、中、大病灶患者累计DCR分别为100%（16/16）、81.82%（9/11）及57.14%（4/7）,生存率分别100%（16/16）、90.91%（10/11）和42.86%（3/7）,小、中病灶患者累计DCR及生存率均高于大病灶患者（P均<0.05）。结论 CT引导下PMCT治疗老年患者周围型NSCLC疗效确切,安全性高。     

根据2013版肝脏影像报告与数据管理系统诊断肝脏病灶的一致性

目的观察根据2013版肝脏影像报告与数据管理系统[LI-RADS(v2013)]诊断肝细胞癌(HCC)发病高风险人群肝脏病灶的一致性。方法由2名医师(医师1、2)独立双盲阅读813例有HCC发病风险患者的1115个病灶的CT/MRI资料,分别采用LI-RADS(v2013)、LI-RADS(v2012,第1版)[即LI-RADS(v1.0)]进行诊断。分析医师间根据LI-RADS(v2013)评估病灶直径、主要影像学征象及分级诊断结果的一致性;以病理结果为金标准,比较根据LI-RADS(v2013)与LI-RADS(v1.0)进行诊断的结果差异。结果医师1、2评估病灶直径的组内相关系数(ICC)为0.998;评价动脉期高强化、门静脉期/延迟期低强化及包膜的Kappa系数分别为0.87、0.86、0.72;LI-RADS(v2013)分级诊断观察者内Kappa系数为0.85。2名医师协商后的最终分级诊断结果与金标准的Kappa系数为0.85;诊断阳性(LR3~5级)病灶的敏感度、特异度、阳性预测值(PPV)及阴性预测值(NPV)分别为100%(757/757)、80.17%(287/358)、91.43%(757/828)及100%(287/287)。根据LI-RADS(v2013)、LI-RADS(v1.0)诊断阳性病灶差异有统计学意义(P<0.001)。结论医师间评价LI-RADS(v2013)主要影像学征象及分级诊断结果的一致性均较好。     

滑液中PRTN3和MNDA诊断关节假体周围感染的效能：与α-防御素的比较

目的 检测关节滑液中标志物蛋白酶3（proteinase 3,PRTN3）和髓样细胞核分化抗原（myeloid nuclear differentiation antigen,MNDA）在关节假体周围感染（periprosthetic joint infection,PJI）诊断中的临床效能,并与传统标志物α-defensin进行比较。方法 回顾性收集连续65例因怀疑PJI而进行髋膝关节诊断性穿刺病人的关节滑液标本。基于2014年肌肉骨骼感染协会（Musculoskeletal Infection Society,MSIS）标准,将29例纳入PJI组,36例纳入非PJI组。随后使用商用ELISA试剂盒检测关节滑液中的三种标志物水平。采用受试者工作特征（receiver operating characteristic,ROC）曲线分析评价所研究生物标志物的诊断效能,并计算其各自的敏感度、特异度与截断值。结果 PJI组菌培养结果以葡萄球菌为主,占比31%,培养阴性病人占比34.5%。ROC分析结果显示,PRTN3的曲线下面积（area under the curve,AUC）最大,为0.984（95% CI,0.961~1.000),其次是α-defensin,AUC为0.944（95% CI,0.888~1.000）,最后为MNDA,AUC为0.849（95% CI,0.755~0.943）。PRTN3的最佳截断值为318.000（ng/mL）,敏感度为0.931,特异度为0.972。α-defensin的最佳截断值为7.150（μg/mL）,敏感度为0.931,特异度为0.861。MNDA的最佳截断值为4.318（ng/mL）,敏感度为0.862,特异度为0.722。结论 PRTN3和MNDA都是PJI的优秀生物标志物。PRTN3的诊断性能最好,甚至略优于α-defensin。     

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.