造血干细胞基因治疗甲状旁腺功能低下症的实验研究

目的　探讨造血干细胞基因治疗甲状旁腺功能低下症 (HPT)的实验效果。方法　构建重组甲状旁腺素 (PTH)基因的小鼠干细胞病毒 (MSCV)重组质粒 ,转染PA31 7包装细胞 ,G41 8筛选阳性克隆 ,获得的重组病毒液感染造血干细胞 ,静脉注入HPT小鼠血中 ,检测各组小鼠症状改善情况、血PTH及血钙变化情况。结果　获得滴度为 2× 1 0 7CFU(集落形成单位 ) /ml的分泌人PTH的浓缩病毒悬液 ,1× 1 0 6 个细胞培养 48h时PTH的分泌量为 1 5ng。经聚合酶链反应 (PCR)扩增未检测到有野生型病毒存在 ,可以安全应用。感染造血干细胞输注后 ,实验组动物未再出现HPT临床表现 ,而且血钙及血PTH均可长期保持在接近正常值范围内 ,较单纯注射浓缩病毒悬液具有更好的疗效。结论　获得MSCV PTH重组质粒及高滴度的分泌人PTH的浓缩病毒悬液。整合有PTH基因的造血干细胞输注后达到较长期治愈小鼠HPT ,为进一步HPT的临床基因治疗提供了可靠依据。     

胚胎干细胞转基因治疗甲状旁腺功能低下症

目的　探讨小鼠胚胎干细胞 (TC 1)转基因治疗甲状旁腺功能低下症 (HPT)。方法包装出重组人甲状旁腺素 (PTH )基因的小鼠干细胞病毒 (MSCV) ,以lml重组病毒液加入 poly brene(终浓度 8mg/L)感染TC 1细胞 ,检测基因转导效率 ,PTH分泌情况 ;以及每 1× 10 5个 /mlTC 1细胞注入模型鼠体内各组小鼠血PTH和血钙变化情况。结果　获得滴度为 2× 10 7集落形成单位 (CFU) /ml的重组逆转录病毒 ,其感染TC 1的效率为 70 % ,每 10 6 未分化TC 1每 48h分泌PTH10ng。重组有PTH基因的TC 1细胞注入模型鼠体内后 ,在观察期间实验组动物血PTH和血钙均保持在接近正常值范围内。结论　MSCV介导外源PTH基因可高效转导TC 1并持续分泌PTH ;内环境并不是决定TC 1分化的唯一因素。经基因转导的TC 1可较好的改善模型鼠的症状 ,是未来细胞移植的一种潜在来源。     

小鼠胚胎干细胞转基因治疗甲状旁腺功能低下症的实验研究

目的　探讨小鼠胚胎干细胞 (TC 1)转基因治疗甲状旁腺功能低下症 (HPT)。方法包装出重组人甲状旁腺素 (PTH )基因的小鼠干细胞病毒 (MSCV) ,以其感染小鼠ESCs ,检测基因转导效率 ,PTH分泌情况 ;观察体内外分化情况 ,以及注入模型鼠体内各组小鼠血PTH和血钙变化情况。结果　获得滴度为 2× 10 7集落形成单位 (CFU ) /ml的重组逆转录病毒 ,经聚合酶链反应(PCR)扩增未检测到有野生型病毒存在 ,可以安全应用。感染TC 1的效率为 70 % ,每 10 6未分化TC 1每 48h分泌PTH约 10ng。重组有PTH基因的TC 1在体内外均可分化出三胚层组织 ,注入模型鼠体内 ,在观察期间实验组动物未再出现甲旁低表现 ,而且血PTH和血钙均保持在接近正常值范围内。结论　MSCV介导外源PTH基因可高效转导TC 1并持续分泌PTH ;体内外分化实验证明TC 1具有全能性 ,而且内环境并不是决定TC 1分化的唯一因素。经基因转导的TC 1可较好的改善模型鼠的症状 ,是未来细胞移植的一种潜在来源。     

甲状旁腺激素基因治疗甲状旁腺功能低下症

目的观察甲状旁腺激素(PTH)基因和蛋白体外表达情况,并评价其基因治疗甲状旁腺功能低下模型鼠的作用。方法(1)以脂质体将质粒pcDPG分别1次和多次转染293细胞,观察绿色荧光蛋白(GFP)的表达并计算转染率;(2)转染24、48、72和96h后real-ti me定量PCR和Western blot法检测PTH基因与蛋白表达,并活性鉴定;(3)建立甲状旁腺功能低下症模型,将pcDPG质粒多次肌肉注射治疗,监测血钙和PTH值、存活时间及各器官病理变化。结果转染后24h即见GFP表达,72h达高峰,96h开始减少;多次转染后GFP表达率可达90%以上;PTHcD-NA拷贝数转染24h为5×103,72h达最高为8×104,多次转染显著增高(P<0.01);Western blot见48h和72h有PTH蛋白表达,其可对抗甲状旁腺切除小鼠抽搐症状;术后第2天血钙与PTH明显低于术前(P<0.05),pcDPG质粒大、中剂量组连续治疗48h后血钙与PTH值均恢复正常。结论重组PTH基因治疗甲状旁腺功能低下模型鼠有较好的疗效。     

甲状腺全切除术中保护甲状旁腺功能研究分析

目的总结甲状腺全切除术中甲状旁腺功能的保护方法。方法回顾性分析2009年10月至2014年6月收治的42例行甲状腺全切除术患者的临床资料,比较手术前后血清甲状旁腺激素(PTH)、血钙水平变化。结果术后PTH暂时低下者19例(45.2%),低钙血症者9例(21.4%),术后30 d复查血清PTH及血钙均恢复正常,未见永久性甲状旁腺功能低下的病例。术后第1、3、5天,血清PTH较术前明显降低(P0.05),而术后30 d,血清PTH与术前无显著性差异(P0.05)。血钙水平除了术后第1天、第3天低于术前(P0.05),其余时间点与术前均无显著性差异(P0.05)。结论甲状腺全切除术中加强对甲状旁腺解剖位置的辨别、血供的保护,可有效减少术后甲状旁腺的损伤,避免严重并发症的发生。     

人骨形成蛋白7基因重组2型腺相关病毒载体的构建及其在骨髓间充质干细胞中的表达

目的构建人骨形成蛋白7基因（hBMP7）重组腺相关病毒载体,并观察其在兔骨髓间充质干细胞中的表达。方法将骨形成蛋白7基因片段克隆入穿梭质粒pUC18获得重组质粒pUC18-hBMP7。KpnⅠ和鼠Ⅱ双酶切质粒pUC18-hBMP7／与pSNAV,用T4DNA连接酶连接分别回收的两片段后转化大肠杆菌DH5α感受态细胞,获得重组质粒PSNAV—hBMP7／,转染BHK-21细胞,筛选培养,用能表达Rap和Cap的重组Ⅰ型单纯疱疹病毒HSVl-rc／△UL2感染此细胞,裂解细胞收获病毒液。采用氯仿处理-PEG／NaCl沉淀-氯仿抽提法分离浓缩、纯化与测定病毒滴度。用rAAV2-hBMP7／和rAAV2-EGFP在体外分别转染兔骨髓间充质干细胞。流式细胞仪、RT-PCR和Western—blot方法检测兔骨髓间充质干细胞中hBMP-7基因的转录和表达。结果成功构建具有感染活性的重组腺相关病毒载体rAAV2-hBMP7／,病毒载体对兔骨髓间充质干细胞早期转染效率可达99．8％,hBMP7／在兔骨髓间充质干细胞中可得到转录和表达。结论成功构建了人骨形成蛋白7基因重组腺相关病毒载体,rAAV2-hBMP7／载体在体外可转染兔骨髓间充质干细胞,并获得较高的转染效率。     

甲状腺不同手术方式对甲状旁腺功能的影响

目的:探讨甲状腺不同手术方式术后甲状旁腺素(PTH)、血钙的变化,总结预防甲状腺术后甲状旁腺功能减退发生的方法及并发症的处理。方法:检测2012年1—5月191例甲状腺手术患者术前及术后血清PTH、血钙,比较术前、术后的变化,并按照手术范围分7组,比较各组之间术后PTH、血钙的变化。结果:各组术后较术前比较,血钙、血PTH均明显下降(P0.05)。同组术后1 d与4 d血PTH、血钙之间比较,差异无统计学意义(P0.05)。各组低血PTH、症状性低钙血症的发生率以及术后PTH下降幅度的比较:全甲状腺切除+双侧颈中央区淋巴清除组、全甲状腺切除+一侧改良颈清+对侧颈中央区淋巴清除组甲状腺双叶切除组甲状腺单叶切除组,其差异有统计学意义(P0.05﹚,而在全甲状腺切除,以及同样范围的颈中央区淋巴清除的基础上,是否行改良颈清,对于术后低PTH血症及症状性低钙血症的发生率以及PTH下降的幅度,差异无统计学意义(P0.05﹚。低血钙的发生率比较:甲状腺单侧腺叶切除与其他6种手术方式比较、甲状腺双侧腺叶切除与全甲状腺切除+一侧改良颈清+对侧颈中央区淋巴清除比较,差异有统计学意义(P0.05﹚。结论:各种甲状腺术式对甲状旁腺功能均有不同程度的影响,手术范围越大,术后并发甲状旁腺功能减退的可能性越大。预防术后甲状旁腺功能减退的根本,就在于术中甲状旁腺的保护。     

全甲状腺切除术后甲状旁腺的功能监测

目的 评估全甲状腺切除术后甲状旁腺功能减退症发生情况,探索早期预测术后低钙血症的方法.方法 对124例患者(甲状腺癌46例、结节性甲状腺肿78例)行全甲状腺切除术,恶性患者加行淋巴结清扫术,术前、术后1 h、1 d、2 d检测血钙和血PTH,观察术后甲状旁腺功能减退症发生情况,并用受试者工作特征曲线研究低钙血症早期预测指标.结果 58例发生术后暂时性甲状旁腺功能减退症(46.8%),甲状腺癌组22例(47.8%),结节性甲状腺肿组36例(46.2%),两组之间无明显差异(λ2=0.033,P=0.857);1例发生永久性甲状旁腺功能减退症(0.8%),发生在甲状腺癌组.术后90例(72.6%)出现血钙下降,58例(46.8%)出现血PTH下降,40例(32.3%)出现低钙症状.甲状腺癌组术后血钙(F=21.358,P=0.000)、血PTH(F=18.253,P=0.000)下降程度重于结节性甲状腺肿组,术后1 h血PTH下降百分比可很好的预测有临床症状的低钙血症(曲线下面积为0.933),以PTH下降76.6%作为分界点,此时预测有临床症状的低钙血症的敏感性为89.7%,特异性为87.9%. 结论全甲状腺切除术加行淋巴结清扫会加重术后血钙、血PTH下降程度但不会增加甲状旁腺功能减退症发生率;术后1 h血PTH下降百分比可预测低钙血症的发生.     

原发性甲状旁腺功能亢进的诊断与治疗

原发性甲状旁腺功能亢进症（primaryhyperpa-rathyroidism，PHPT）是由于病变的甲状旁腺组织合成和分泌过多的甲状旁腺激素（PTH）引起高血钙、低血磷及高尿钙的一种多系统疾病。     

继发性甲状旁腺功能亢进高磷血症的治疗

继发性甲状旁腺功能亢进（SHPT）是指由于机体内存在刺激甲状旁腺的因素,特别是低血钙、低血镁和高血磷,腺体受刺激后增生、肥大,分泌过多的甲状旁腺素（PTH）,代偿性维持正常血钙、血磷水平。     

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 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.     

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.     

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.     

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.     

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.