六月霜中提取物清除O2.-和OH.自由基

应用氮蓝四唑 (NBT)光还原法 ,对六月霜中提取物清除超氧离子自由基O2 ·- 的效果进行了测定 .结果显示 ,六月霜提取物对超氧离子自由基有较强的清除效果 ,清除效果与提取物中黄酮质量浓度有关 ,当黄酮质量浓度达到一定值时 ,对O2 ·- 的清除效果可高达 88.4 1% .提取物与抗坏血酸 (Vc)进行了对照实验 ,结果显示其对O2 ·- 的清除能力比Vc高 .六月霜提取物在Vc—Cu2 —H2 O2 体系中 ,对OH·自由基的清除效果的研究显示 ,最高清除率为 84 .0 2 % .     

白芷活性提取物清除自由基与抗氧化作用

研究了香辛料白芷中活性物的提取工艺,试验结果表明:以体积分数75%乙醇为溶剂,白芷粉碎度为20目,固液比保持1 g∶10 mL,回流萃取1h,提取2次,能有效提取出白芷中活性成分.用邻苯三酚自氧化法和亚硝基R盐-Co3+褪色法对白芷提取物进行了自由基清除、抗氧化性能的研究.发现白芷提取物能有效清除自由基,当质量浓度为1.0×10-3g/mL时,提取物对过氧阴离子自由基(O2-·)和羟基自由基(·OH)的清除率分别为23.40%和69.35%,可作为一种性能良好的新型天然清除自由基、抗氧化剂,应用于食品和药品中.     

红薯中黄酮提取及抗氧化研究

作者研究了从红薯中提取黄酮类活性物质的最佳方法以及该提取物的抗氧化性。设计四因素三水平的正交试验,用水浴法和超声法对红薯中黄酮类物质的提取方法进行了研究,选取最佳条件。通过DPPH体系法,氮蓝四唑(NBT)光化合还原法和抗坏血酸Cu2+-H2O2体系法,分别研究最佳条件下薯皮薯肉提取物的抗氧化性。结果表明:水浴法以固液质量体积比1g∶15mL,体积分数70%乙醇水溶液在65℃浸提1h为最佳;超声法以固液质量体积比1g∶15mL,体积分数70%乙醇水溶液超声35min浸提为最佳。在提取方法中,超声法优于水浴法,其黄酮得率分别为2.80mg/g和2.14mg/g;抗氧化性实验表明,薯肉中提取的黄酮类活性物质对DPPH、O2-·、·OH的清除率分别可达80.34%、66.23%、53.32%,薯皮中提取的黄酮类活性物质的清除率分别可达86.81%、84.59%、75.06%。     

大麦总多酚不同溶剂提取物对DPPH自由基清除能力的影响

酚类化合物是大麦中主要的抗氧化物质之一,直接影响到麦芽、麦汁和啤酒的品质.研究了体积分数100%的甲醇、体积分数8O%的甲醇、体积分数8O%的乙醇、体积分数8O%的丙酮和水等5种不同提取溶剂对大麦游离多酚和结合多酚提取率的影响,以及不同溶剂提取物清除DPPH自由基能力的差异.结果表明:提取溶剂对大麦多酚的提取效率有显著影响,不同溶剂提取物清除DPPH自由基的能力有显著性差异;其中以80%丙酮溶液为提取溶剂时,所得提取物的游离多酚质量分数及其对DPPH自由基清除率最高,可作为大麦抗氧化物质的提取溶剂;不同品种大麦间游离总多酚质量分数及其对DPPH自由基清除率存在显著差异;结合Folin-Ciocaheu法和DPPH自由基清除率法分剐测定大麦总多酚质量分数和抗氧化力,可初步评价大麦原料的抗氧化特性.＃     

保元抗癌口服溶液清除超氧自由基与DPPH作用

目的考察保元抗癌口服溶液对超氧自由基（O－2）和1,1 二苯基 2 苦肼自由基（DPPH）的清除作用。方法采用电子自旋共振（ESR）技术,以DPPH和 O－2为检测项目,测定保元抗癌口服溶液对自由基的清除效果。结果保元抗癌口服溶液稀释50倍时清除O－2和DPPH自由基分别为81.32%和98.47%。结论保元抗癌口服溶液对O－2和DPPH自由基均有较好清除作用,并呈一定的量效关系。     

乌饭树树叶中黄酮类色素的抗氧化活性

对乌饭树树叶中提取出的色素进行了分离纯化，分离出了4种黄酮类物质。并且对这4种物质清除活性氧自由基的能力进行了研究，发现乌饭树提取物都具有很强的清除自由基能力，清除能力最强的槲皮素和6#提取物的IC50达到了5．9μg/mL左右。     

金莲花黄酮微波辅助提取及其抗氧化性

采用单因素分析结合正交试验的方法,研究了金莲花黄酮微波辅助提取的工艺条件,以清除DPPH自由基法,对金莲花黄酮的抗氧化性进行了分析,并比较了金莲花黄酮、VC和BHT的抗氧化能力.实验结果表明:微波辅助提取金莲花黄酮的最佳工艺条件是体积分数60%乙醇为溶剂,每克料浸提剂体积为20 mL,微波功率600 W,温度60℃,提取时间2 min.在此工艺下,金莲花黄酮提取率为83.7%;金莲花黄酮能有效地清除DPPH自由基,具有较强的抗氧化能力,与VC>和>BHT相比,其抗氧化能力为VC金莲花黄酮BHT.另外,研究发现金莲花黄酮与VC和金莲花黄酮与BHT均具有一定的抗氧化协同效应.     

黄芪总黄酮、黄芪多糖、 甘草次酸及阿魏酸清除氧自由基作用的研究

目的 :比较黄芪多糖、黄芪总黄酮、甘草次酸及阿魏酸对氧自由基的清除作用 ,为寻找天然高效的自由基清除剂提供参考。　方法 :采用分光光度不测定羟自由基 (· OH)及超氧阴离子自由基 (O2 - ) ,计算表观清除率及 IC5 0 。　结果 :黄芪多糖、黄芪总黄酮、甘草次酸及阿魏酸对 (· OH)的 IC5 0 分别为 0 .0 5 9、 0 .0 2 4、 0 .0 32 5、 0 .0 36 mg/ ml;其清除能力 :黄芪总黄酮 >甘草次酸 >阿魏酸 >黄芪多糖 ;黄芪多糖、黄芪总黄酮、阿魏酸及甘草次酸对 (O2 - )的 IC5 0 分别 0 .0 9、0 .0 86、0 .0 12、 0 .0 12、 0 .0 14mg/ ml,其清除能力 :阿魏酸 >甘草次酸 >黄芪多糖 >黄芪总黄酮。　结论 :黄芪多糖、黄芪总黄酮、甘草次酸及阿魏酸对 (· OH)及 (O2 - )均有较强的清除作用 ,且清除能力均与浓度呈明显的显效关系     

红花红色素的抗氧化活性

从红花中提取了红花红色素,研究了该色素对超氧自由基、DPPH自由基的清除作用,以及对β 胡萝卜素 亚油酸氧化体系的抑制作用,以此来评价红花红色素的抗氧化能力.结果表明,红花红色素对超氧自由基和β 胡萝卜素 亚油酸氧化体系均有较明显的抑制作用.     

葡-半乳低聚糖体外抗氧化活性研究

作者研究了高、中、低3种不同聚合度葡-半乳低聚糖在DPPH体系和羟自由基体系中清除自由基的能力.结果表明:高聚合度葡-半乳低聚糖对DPPH自由基的清除能力较中、低聚合度葡-半乳低聚糖强,IC50为13 mg·mL-1;而对·OH的清除能力,中聚合度葡-半乳低聚糖较强,其IC50为21 mg·mL-1.高、中聚合度的葡-半乳低聚糖在两种体系中均有较好的清除作用,聚合度大小影响葡-半乳低聚糖清除自由基的活性.     

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.     

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.     

The analgesic effect of racemic ketamine in patients with chronic ischemic pain due to lower extremity arteriosclerosis obliterans

Background : Ketamine in sub-dissociative doses has been shown to have analgesic and phantom-Limb pain, where conventional treatment has often failed. Chronic ischemic pain due to lower extremity arteriosclerosis obliterans often responds poorly to analgesics, and the pain-generating mechanisms are not well understood.
Methods : Eight patients with rest pain in the lower extremity due to arteriosclerosis obliterans were given sub-dissociative doses of 0.15, 0.30, or 0.45 mg/kg racemic ketamine and morphine 10 mg as a 5-min infusion on four separate days in a cross-over, double-blind, randomised protocol. Plasma levels of (S)- and (R)-ketamine and their nor-metabolites were analysed with an enantioselective high-performance liquid chromatography (HPLC) method. Pain levels were evaluated with a visual analogue scale (VAS).
Results : Individual pain levels were highly variable during and after all the infusions but the pooled pain levels showed a dose-dependent analgesic effect of ketamine with a transient but complete pain relief in all patients at the highest dose (0.45 mg/ kg). Side-effects, mainly disturbed cognition and perception, were pronounced and dose-dependent. Morphine 10 mg had an analgesic peak at 20 min and 5/8 patients had complete pain relief. The remaining 3 patients also had high baseline pain scores, indicating a higher analgesic potency for the 0.30 and 0.45 mg/ kg ketamine doses than for morphine 10 mg.
Conclusion : We have demonstrated a potent dose-dependent analgesic effect of racemic ketamine in clinical ischemic pain. Due to a narrow therapeutic window, this analgesic effect is probably best utilised in combination with other analgesics.     

Intravenous endotoxin does not increase tissue extravasation of albumin in rats

Background : It is unclear whether activation of the inducible nitric oxide synthase (iNOS) increases or decreases the extravasation of plasma.
Methods : Chloralose anaesthetised male Wistar rats received E. coli lipopolysacharide (LPS), 3 mg kg^-1 i.v., or the corresponding volume of saline, 3 or 5 h before the end of the experiment. Mean arterial pressure (MAP) and heart rate (HR) were recorded. Tissue clearance of radio-labelled albumin, during the last 2 h of each experiment, was determined by a double-isotope method. In separate animals, the serum concentration of nitrite and nitrate was determined, 5 h after LPS or the solvent.
Main Results : LPS initially decreased MAP and lastingly increased HR. In the 3-h LPS animals (n=8), tissue plasma clearance was lower in the heart and calf muscle and increased only in diaphragm, compared to corresponding control animals (n=8). In the 5-h LPS rats, clearance was lowered (n=8) in the entire gastrointestinal tract and in testes, compared to controls (n=8). The serum nitrite/nitrate concentration was higher in animals given LPS (n=6) than in controls (n=6).
Conclusion : After LPS, tissue clearance of albumin was not increased in any major tissue, in spite of increased serum levels of NO end products. Apparently, after activation of iNOS, the augmented release of NO is not necessarily associated with increased albumin extravasation.     

Adrenaline markedly improves thoracic epidural analgesia produced by a low-dose infusion of bupivacaine, fentanyl and adrenaline after major surgery: A randomised, double-blind, cross-over study with and without adrenaline

Background: Basic pharmacological research indicates that there are synergistic antinociceptive effects at the spinal cord level between adrenaline, fentanyl and bupivacaine. Our clinical experience with such a mixture in a thoracic epidural infusion after major surgery confirms this. The objectives of the present study were to evaluate the effects on postoperative pain intensity, pain relief and side effects when removing adrenaline from this triple epidural mixture. Methods: A prospective, randomised, double-blind, cross-over study was carried out in 24 patients after major thoracic or abdominal surgery. Patients with only mild pain when coughing during a titrated thoracic epidural infusion of about 10 ml · h^?1 of bupivacaine 1 mg · ml^?1, fentanyl 2 μg · ml^?1, and adrenaline 2 μg · ml^?1 were included. On the 1^st and 2^nd postoperative days each patient was given a double-blind epidural infusion, at the same rate, with or without adrenaline. The effect was observed for 4 h or until pain when coughing became unacceptable in spite of a rescue analgesic procedure. Rescue analgesia consisted of up to two epidural bolus injections per hour and i.v. morphine if necessary. All patients received rectal paracetamol 1 g, every 8 h. Fentanyl serum concentrations were measured with a radioimmunoassay technique at the start and end of each study period. Main outcome measures were extent of sensory blockade and pain intensity at rest and when coughing, evaluated by a visual analogue scale, a verbal categorical rating scale, the Prince Henry Hospital pain score, and an overall quality of pain relief score. Results: The number of hypaesthetic dermatomal segments decreased (P <0.001) and pain intensity at rest and when coughing increased (P <0.001) when adrenaline was omitted from the triple epidural mixture. This change started within the first hour after removing adrenaline. After 3 h pain intensity when coughing had increased to unacceptable levels in spite of rescue analgesia (epidural bolus injections and i.v. morphine). Within 15–20 min after restarting the triple epidural mixture with adrenaline, pain intensity was again reduced to mild pain when coughing. Serum concentration of fentanyl doubled from 0.22 to 0.45 ng · ml^?1 (P <0.01), and there was more sedation during the period without adrenaline. Conclusions: Adrenaline increases sensory block and improves the pain-relieving effect of a mixture of bupivacaine and fentanyl infused epidurally at a thoracic level after major thoracic or abdominal surgery. Serum fentanyl concentrations doubled and sedation increased when adrenaline was removed from the epidural infusion, indicating more rapid vascular absorption and systemic effects of fentanyl.     

Utilisation des médicaments prokinétiques en réanimation : indications et limites ?

Enteral feeding is often limited by gastric and intestinal motility disturbances in critically ill patients, particularly in patients with shock. So, promotility agents are frequently used to improve tolerance to enteral nutrition. This review summaries the pathophysiology, presents the available pharmacological strategies, the clinical data, the counter-indications and the principal limits. The clinical data are poor. No study demonstrates a positive effect on clinical outcomes. Metoclopramide and erythromycin seems to be the more effective. Considering the risk of antibiotic resistance, the first line use of erythromycin should be avoided in favor of metoclopramide.     

Anesthésie générale chez l’enfant : quid des pratiques en 2010 ?

Introduction

The practice of pediatric anesthesia requires a regular update of scientific knowledge and technical skills. To provide the most adequate Continuing Medical Education programs, it is necessary to assess the practices of pediatric anesthesiologists. Thus, the objective of this survey was to draw a picture of the current clinical practices of general anesthesia in children, in France.

Material and methods

One thousand one hundred and fifty questionnaires were given to anesthesiologists involved in pediatric cases. These questionnaires collected information on various aspects of clinical practice relative to induction, maintenance, recovery from general anaesthesia and also classical debated points such as children with Upper Respiratory Infection (URI), emergence agitation, epileptoid signs or anaesthetic management of adenoidectomy. Differences in practices between CHG (general hospital), CHU (teaching hospital), LIBERAL (private) and PSPH (semi-private) hospitals were investigated.

Results

There were 1025 questionnaires completed. Fifty-five percent of responders worked in public hospitals (CHG and CHU); 77% had a practice that was 25% or less of pediatric cases. In children from 3 to 10 years: 72% of respondents used always premedication and two thirds performed inhalation induction in more than 50% of cases. For induction, 53% used sevoflurane (SEVO) at 7 or 8%. Respondents from LIBERAL used higher SEVO concentrations. Tracheal intubation was performed with SEVO alone (37%), SEVO and propofol (55%) and SEVO with myorelaxant (8%), 93% of respondents used a bolus of opioid. For maintenance, the majority of respondents used SEVO associated with sufentanil; desflurane and remifentanil were more frequently used in CHU. Two thirds of respondents used N₂O. Depth of anesthesia was commonly assessed by hemodynamic changes (52%), end tidal concentration of halogenated (38%) or automated devices based on EEG (7%). In children with URI, 98% of respondents used SEVO for anesthesia. To control the airway 42% used a tracheal tube, 30% a laryngeal mask and 20% a facial mask. Emergence agitation was an important concern for two thirds of respondents, while epileptoid signs were considered as important by only 20%. Eighty-nine percent of respondents practiced anesthesia for adenoidectomy. Anesthesia was induced by inhalation of SEVO 7–8% (41%), 6% (39%) or 4% (12%), 66% put an intravenous line (less frequently in LIBERAL). 67% of the responders managed adenoidectomy without any device to control the airway (more frequently in LIBERAL), 32% administrated a bolus of opioid (less frequently in LIBERAL).

Discussion

This survey demonstrated that the practices regarding general anesthesia in children are relatively homogenous. Most of the differences appeared between LIBERAL and the others structures; the anaesthetic management for adenoidectomy illustrates these findings.     

Intérêt d’une rééducation précoce pour les patients neurologiques

Rehabilitation improves the functional prognosis of patients after a neurologic lesion, and tendency is to begin rehabilitation as soon as possible. This review focuses on the interest and the feasibility of very early rehabilitation, initiated from critical care units. It is necessary to precisely assess patients’ impairments and disabilities in order to define rehabilitation objectives. Valid and simple tools must support this evaluation. Rehabilitation will be directed to preventing decubitus complications and active rehabilitation. The sooner rehabilitation is started; the better functional prognosis seems to be.     

Risiko Schlaganfall — Öffentlichkeitsarbeit und Aufklärung dringend erforderlich

Zusammenfassung Das wesentliche — und zugleich noch wenig ausgeschöpfte — Potenzial der Schlaganfallmedizin liegt in der langfristigen Prophylaxe. Durch Beeinflussung von Lifestylefaktoren wie Ernährungsgewohnheiten, Zigarettenkonsum und körperlichem Training durch entsprechende Aufklärung ließe sich ein erheblicher Teil an zerebralen Ereignissen vermeiden. Ein weiterer in Deutschland noch zu wenig beachteter Faktor ist die konsequente Blutdruckeinstellung. Breitgestreute Aufklärung könnte außerdem potenziellen Patienten helfen, bereits auftretende Warnsymptome wie die transiente ischämische Attacke richtig einzuschätzen, um eine rechtzeitige Behandlung zu ermöglichen.