糖基化终末产物对人外周血内皮祖细胞生物学特性的影响

Objective In addition to be involved in the angiogenesis, endothelial progenitor cells (EPCs) have roles in endothelium repairing, wound healing, and for protecting blood vessels from restenosis, Advanced glycation end products (AGEs) facilitate the development and progression of atherosclerosis, diabetes associated vascular complications and uremia through various mechanisms such as damaging the endothelium, promoting leukocyte adhension, increasing the aggregation of platelets, and stimulating the proliferation of vascular smooth muscles. This study was designed to explore whether AGEs have effects on biological characteristics of EPCs in cultured human peripheral blood cells. Methods Total mononuclear cells (MNCs), isolated from human peripheral blood by density gradient centrifugatian and adherence cells filtration, were incuba-ted in fibronectin-coated culture dishes. Endothelial cells were identified by means of the adsorption of ulex eurepaeus-aggluti-nin- Ⅰ (UEA- Ⅰ) labelled with fluorescein isothiacyanate (FITC) and Dil-acLDL internalization. Four days later,various con-centrations of AGEs were added to the adherent cells and remained for48 hours. MTT assay and Boyden chamber were used for observing the proliferation and migration of EPCs. Human fibronectin was used to examine the adhesion ability of EPCs. Apop-tosis was induced in the EPCs with formaldehyde and Dnase Ⅰ as a positive control group. Annexin V-FITC/PI and TUNEL method of flow cytometry were used for evaluating the effects of AGEs on the rate of apeptosis in the EPCs. Results AGEs at high concentration decreased the number of EPCs independently (P < 0.01) ; reduced the proliferation (P < 0.01), migration (P<0.001) and adhesive capacity (P<0.05) of EPCs significantly,as well as increasing the apoptasis rate of EPCs in the early stage (P < 0.001). Conclusion AGEs may have adverse effects on EPCs from cultured human peripheral MNCs, such as decreasing their numbers and impairing their functions.     

Radioprotective effects of the expression of FLT3 ligand regulated by Egr-1 regulated element on radiation injury of SCID mice

Objective:In order to explore the radioprotective effects of the expression of hematopoietic growth factors regulated by radio-inducible promoter on radiation injury. Methods:The human FL (Flt3 ligand) cDNA and EGFP (enhanced green fluorescent protein) cDNA were linked together with IRES and then inserted into the eukaryotic expression vector pCI-Egr, which was constructed by substituting CMV promoter in pCIneo with the Egr-1 promoter (Egr-EF). The vector was transferred into human bone marrow stromal cell line HFCL by lipofectin. The transduced cell clones (HFCL/EF) had been selected by the addition of G418. The cells were exposed to γ-radiation by 60 Co source for 0.5-20Gy. The expressions of transduced cells were detected with FACS, Northern blot ELISA and CFU assay. The HFCL/EF and CD34+ cells from human umbilical cord blood were one after the other transplanted i.v. into sublethally irradiated severe combined immunodeficient (SCID) mice. The white blood cell amount in peripheral blood and human cell engrafted in recipent mice were detected by flow cytometry and CFU-GM etc. Results:The activity of EGFP in transduced cells increased by 3.1 fold as compared to non-transduced cells at 18h after exposure to 2.5Gy. The amounts of secreted FL in serum-free supernatants of Egr-EF increased by 605.46±107.21pg/ml, which were significantly higher than the control group (214.45±35.61pg/ml). The effects of FL in HFCL/EF cultural supernatants on expansion of CD34+ cells derived from cord blood in the presence of SCF, IL-6 and IL-3 were also studied. The results showed that at day 10 of culture the number of CD34+ cells increased by 173. 09±11.58×103/ml, which was significantly higher than that of non-radiation group(68. 04± 13. 73 × 103/ml). It showed that radiation can enhance the ability of the supernatants containing FL of HFCL/EF to expand early hematopoietic progenitor cells and protect hematopoietic cells from radiation-injury effects. The HFCL/EF and CD34+cells from human umbilical cord blood were one after the other transplanted i. v. into sublethally irradiated severe combined immunodeficient (SCID) mice. In contrast to two control groups (HFCL and HFCL/F), HFCL/EF (the Egr-1 regulatory element-drived expression of FL gene therapy) resulted in a proportionally obvious increase in the number of the white blood cell at early stage after radiation, while no significant differences were found for CD45+ 、CD34+ cells in bone marrow cells. In contrast to two control groups (HFCL and HFCL/F), HFCL/EF (the Egr1 regulatory element-drived expression of FL gene therapy) resulted in a proportionally obvious increase in the number of the white blood cell at early stage after radiation, without significant differences being found for CD45+、CD34+ 、CFU-GM and marrow nucleared cells in bone marrow cells. Conclusions:The results suggested both in vivo and in vitro use of the gene therapy of FL gene regulated by Egr-1 promoter could protect hematopoiesis from irradiation-induced damage.     

The in vitro myelin formation in neurospheres of human neural stem cells

Objective: To explore the culture conditions of human neural stem cells and to investigate the ultrastructure of neurospheres. Methods: The cells from the embryonic human cortices were mechanically dissociated. N2 medium was adapted to culture and expand the cells. The cells were identified by immunocytochemistry and EM was applied to examine the ultrastructure of neurospheres. Results: The neural stem cells from human embryonic brains were successfully cultured and formed typical neurospheres in suspension, and most of the cells expressed vimentin, which was a marker for neural progenitor cells, and the cells could differentiate into neurons, astrocytes and oligodendrocytes. In vitro myelin formation in neurospheres were observed at an early stageof culture. Conclusions: Human neural stem cells can be cultured from embryonic brains, can form the typical neurospheres in suspension in vitro and have the ability of myelinating, and may be potential source for transplantation in treating myelin disorders.     

不同浓度七氟醚对人肺腺癌A549细胞Survivin蛋白表达的影响

Objective To investigate the effects of different concentrations of sevoflurane on Survivin expression in human adenocarcinoma cell line A549. Methods A549 cells were obtained from Shanghai Cell Biology Medical Research Institute, Chinese Academy of Sciences and inoculated in 96 well culture plate. After being cultured for 24 h, the cells were randomly divided into 4 groups: Ⅰ , Ⅱ , Ⅲ and Ⅳ groups exposed to 95 % O2 -5 %CO2,1.7%, 3.4% and 5.1% sevoflurane respectively. A549 cells were exposed to sevoflurane for 2, 4 and 6 h respectively and then cultured for another 48 h in Ⅱ , Ⅲ and Ⅳ groups. Proliferation of A549 cells were measured by methyl thiazolyl tetrazolium (MTT) assay, and apoptosis was detected with flow cytometer at 48 h after 2, 4 and 6 h sevoflurane exposure. The expression of Survivin in A549 cells was determined by Western blot analysis at 48h after 4 h sevoflurane exposure. Results The rate of proliferation inhibition and percentage of apoptotic cells were significantly higher while the expression of Survivin was significantly lower in a concentration-dependent manner in Ⅱ , Ⅲ and Ⅳ groups as compared with group Ⅰ . Conclusion Sevoflurane can inhibit proliferation and induce apoptosis of A549 cells by inhibition of Survivin expression.     

非小细胞肺癌循环肿瘤细胞的定量检测意义

Objective To investigate the sensitivity, specificity and clinical significance of detecting circulating tomor cells (CTCs) in NSCLC. Methods Twenty-five patients who undetwent surgical resection for NSCLC form Jan 2007 to Apr 2007 were in- cluded in this study. Control group included 10 patients with benign pulmonary diseses (2 case of hamartoma and 8 case of pulmonary tu berculosis) and 10 healthy volunteers. The pulmonary veins blood and peripheral vein blood were collected respectively. The CD326 immunomagnetic beads and CK-fluorescein isothiocyanate (CK-FITC) were served as the marker antibodies of CTCs. Firstly mononu- clear cell marked by minibeads conjugated with CD326, the mononuclear cells were enriched and separated though Magnetic-activated cell separation(MACS), then the positive separtion cells were marked by anti-CK-FTTC and anti-leukocyte antibody CD45-phyco- erythrine (anti-CD45-PE), finally those cells detected and analyzed by flow cytometry . Results For stage Ⅰ and stage Ⅱ patients (n= 16), CTCs were detected from peripheral vein blood of in 5 (5/16, 31.25%) and from pulmonary veins blood in 9 (9/16, 56.25%). For stage Ⅲ and stage Ⅳ, CTCs were detected from peripheral vein blood in 5 (5/9, 55.56%) and from pulmonary veins blood in 9(7/9,77.78%).For stage Ⅰ,CTCs were detected from peripheral vein blood in 3(3/13,23%)and from pulmo- nery veins blood in 8(8/13,61.54%).The whole CTCs positive detection rate from pilmonary veins blood was 64%(16/25)which higher than feom peripheral vein blood(40%,10/25)(P<0.05).Conclusion The method was set up by MACS combined with FCM to detect the CTCs of pulmonary veins blood and peripheral vein blood of patients.with NSCLC,MACS combined with FCM may improve detection rate of CTCs.This technique appears to be an efficient to detect circulating tumor cells and may be important for dinical practice in the future.     

非小细胞肺癌循环肿瘤细胞的定量检测意义

Objective To investigate the sensitivity, specificity and clinical significance of detecting circulating tomor cells (CTCs) in NSCLC. Methods Twenty-five patients who undetwent surgical resection for NSCLC form Jan 2007 to Apr 2007 were in- cluded in this study. Control group included 10 patients with benign pulmonary diseses (2 case of hamartoma and 8 case of pulmonary tu berculosis) and 10 healthy volunteers. The pulmonary veins blood and peripheral vein blood were collected respectively. The CD326 immunomagnetic beads and CK-fluorescein isothiocyanate (CK-FITC) were served as the marker antibodies of CTCs. Firstly mononu- clear cell marked by minibeads conjugated with CD326, the mononuclear cells were enriched and separated though Magnetic-activated cell separation(MACS), then the positive separtion cells were marked by anti-CK-FTTC and anti-leukocyte antibody CD45-phyco- erythrine (anti-CD45-PE), finally those cells detected and analyzed by flow cytometry . Results For stage Ⅰ and stage Ⅱ patients (n= 16), CTCs were detected from peripheral vein blood of in 5 (5/16, 31.25%) and from pulmonary veins blood in 9 (9/16, 56.25%). For stage Ⅲ and stage Ⅳ, CTCs were detected from peripheral vein blood in 5 (5/9, 55.56%) and from pulmonary veins blood in 9(7/9,77.78%).For stage Ⅰ,CTCs were detected from peripheral vein blood in 3(3/13,23%)and from pulmo- nery veins blood in 8(8/13,61.54%).The whole CTCs positive detection rate from pilmonary veins blood was 64%(16/25)which higher than feom peripheral vein blood(40%,10/25)(P<0.05).Conclusion The method was set up by MACS combined with FCM to detect the CTCs of pulmonary veins blood and peripheral vein blood of patients.with NSCLC,MACS combined with FCM may improve detection rate of CTCs.This technique appears to be an efficient to detect circulating tumor cells and may be important for dinical practice in the future.     

非小细胞肺癌循环肿瘤细胞的定量检测意义

Objective To investigate the sensitivity, specificity and clinical significance of detecting circulating tomor cells (CTCs) in NSCLC. Methods Twenty-five patients who undetwent surgical resection for NSCLC form Jan 2007 to Apr 2007 were in- cluded in this study. Control group included 10 patients with benign pulmonary diseses (2 case of hamartoma and 8 case of pulmonary tu berculosis) and 10 healthy volunteers. The pulmonary veins blood and peripheral vein blood were collected respectively. The CD326 immunomagnetic beads and CK-fluorescein isothiocyanate (CK-FITC) were served as the marker antibodies of CTCs. Firstly mononu- clear cell marked by minibeads conjugated with CD326, the mononuclear cells were enriched and separated though Magnetic-activated cell separation(MACS), then the positive separtion cells were marked by anti-CK-FTTC and anti-leukocyte antibody CD45-phyco- erythrine (anti-CD45-PE), finally those cells detected and analyzed by flow cytometry . Results For stage Ⅰ and stage Ⅱ patients (n= 16), CTCs were detected from peripheral vein blood of in 5 (5/16, 31.25%) and from pulmonary veins blood in 9 (9/16, 56.25%). For stage Ⅲ and stage Ⅳ, CTCs were detected from peripheral vein blood in 5 (5/9, 55.56%) and from pulmonary veins blood in 9(7/9,77.78%).For stage Ⅰ,CTCs were detected from peripheral vein blood in 3(3/13,23%)and from pulmo- nery veins blood in 8(8/13,61.54%).The whole CTCs positive detection rate from pilmonary veins blood was 64%(16/25)which higher than feom peripheral vein blood(40%,10/25)(P<0.05).Conclusion The method was set up by MACS combined with FCM to detect the CTCs of pulmonary veins blood and peripheral vein blood of patients.with NSCLC,MACS combined with FCM may improve detection rate of CTCs.This technique appears to be an efficient to detect circulating tumor cells and may be important for dinical practice in the future.     

Novel multi-probe RNase protection assay set for detection of endotoxin associated receptors gene expression

Objective: To construct the multi-probe ribonuclease protection assay (RPA) template set to be used for detecting expression patterns of MD-2, TLR4, CD14 mRNAs in human peripheral blood mononuclear cells. Methods : The designed cDNA fragments of the three genes were generated by polymerase chain reaction (PCR)using specific primers and directionally cloned into EcoR I and Hind III sites of expression plasmid pSP72 containing the T7/ promoter, the linearized plasmids was used as template to synthesize anti-sense RNA probes. Then we extracted total RNA from peripheral blood mononuclear cells (PBMC) and detected the dynamic expression patterns of the three genes with RPA method. Results: The proper sequence and orientation of the template set were confirmed by sequencing and the template set was successfully used to assay TLR4, MD-2 and CD14 mRNAs in human PBMC. The results showed that the three detected genes decreased transiently 1-3 hours after 100 ng/ml LPS stimulation. Conclusions: These new RPA multi-probe set provided valuable tool for the simultaneous quantitative determination of expression of TLR4, CD14 and MD-2 mRNAs in both constitutive and inducible types.     

非小细胞肺癌循环肿瘤细胞的定量检测意义

Objective To investigate the sensitivity, specificity and clinical significance of detecting circulating tomor cells (CTCs) in NSCLC. Methods Twenty-five patients who undetwent surgical resection for NSCLC form Jan 2007 to Apr 2007 were in- cluded in this study. Control group included 10 patients with benign pulmonary diseses (2 case of hamartoma and 8 case of pulmonary tu berculosis) and 10 healthy volunteers. The pulmonary veins blood and peripheral vein blood were collected respectively. The CD326 immunomagnetic beads and CK-fluorescein isothiocyanate (CK-FITC) were served as the marker antibodies of CTCs. Firstly mononu- clear cell marked by minibeads conjugated with CD326, the mononuclear cells were enriched and separated though Magnetic-activated cell separation(MACS), then the positive separtion cells were marked by anti-CK-FTTC and anti-leukocyte antibody CD45-phyco- erythrine (anti-CD45-PE), finally those cells detected and analyzed by flow cytometry . Results For stage Ⅰ and stage Ⅱ patients (n= 16), CTCs were detected from peripheral vein blood of in 5 (5/16, 31.25%) and from pulmonary veins blood in 9 (9/16, 56.25%). For stage Ⅲ and stage Ⅳ, CTCs were detected from peripheral vein blood in 5 (5/9, 55.56%) and from pulmonary veins blood in 9(7/9,77.78%).For stage Ⅰ,CTCs were detected from peripheral vein blood in 3(3/13,23%)and from pulmo- nery veins blood in 8(8/13,61.54%).The whole CTCs positive detection rate from pilmonary veins blood was 64%(16/25)which higher than feom peripheral vein blood(40%,10/25)(P<0.05).Conclusion The method was set up by MACS combined with FCM to detect the CTCs of pulmonary veins blood and peripheral vein blood of patients.with NSCLC,MACS combined with FCM may improve detection rate of CTCs.This technique appears to be an efficient to detect circulating tumor cells and may be important for dinical practice in the future.     

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.     

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.