重视野生型胃肠间质瘤的诊断与治疗

胃肠间质瘤是胃肠道最常见的间叶源性肿瘤．c．kil基因或PDGFRA基因的功能获得性突变是其最重要的特征。有10％～15％的胃肠间质瘤不存在c—kit基因及PDGFRA基因的突变．称为野生型胃肠间质瘤。这一类胃肠问质瘤在分子机制及临床特征上与突变型胃肠间质瘤有湿著差异．且其本身存在高度异质性。临床医师在诊断与治疗野生型胃肠间质瘤时应当引起足够的重视。     

1例直肠间质瘤伴发腹腔内神经纤维瘤病1型的诊治过程

正1型神经纤维瘤病(NF1)是一种较常见的遗传性疾病,发病率估计在1/2500～3000,由神经纤维瘤病中的多种突变引起~([1])。NF1患者发生神经、间质性和神经内分泌肿瘤的风险增加并时有报道~([2,3])。胃肠道间质瘤(GIST)为特定的KIT-或PDFGRA-信号传导的间充质肿瘤,NF1伴发GIST患者中,绝大多数肿瘤发生在空肠或回肠,极少发KIT PDGFRA     

Imatinib耐药的胃肠道间质瘤细胞系的建立及其生物学特征鉴定

胃肠道间质肿瘤(GIST)是位于胃肠道或腹腔内的表达KIT(CD117)蛋白的间叶源性肿瘤,大多数存在KIT和血小板源性生长因子受体α-多肽(PDGFRA)基因的突变[1].伊马替尼(Imatinib)是一种口服的ATP的竞争性抑制剂,能竞争性地结合于KIT酪氨酸激酶功能区的ATP结合位点,从而阻断了失控的信号传导通路,因此目前已成为治疗GIST的标准药物.然而一般在Imatinib平均治疗24个月后,将产生继发性耐药.关于Imatinib耐药(包括原发和继发)的机制还不是很清楚.目前认为Imatinib发生耐药的最大可能是由于KIT和PDGFRA基因的继发突变导致Imatinib耐药性克隆的出现.我们通过建立Imatinib耐药的胃肠道间质瘤细胞系,并对其进行生物学特征的初步探讨,明确其耐药的可能机制,探讨GIST发生耐药后的分子改变事件,为GIST的靶向治疗寻找新的分子靶点.     

胃肠间质瘤基因突变和分子靶向治疗相关研究进展

胃肠管间质瘤是最常见的胃肠管原发的间叶源性肿瘤.胃肠管间质瘤的发生是由KIT基因突变导致KIT蛋白的组成性激活引起的.血小板源性生长因子受体α(platelet-derived growth factor receptor alpha,PDGFRA)也与胃肠管间质瘤的发病机制有关.KIT的突变位点主要是exon11、exon9、exon13和exon17;PDGFRA的突变位点主要是exon18、exon12和exon14.胃肠间质瘤的临床病理参数、对甲磺酸依马替尼的反应与突变所在的位置及突变类型相关.甲磺酸伊马替尼是一个选择性的小分子酪氨酸激酶抑制剂,其临床应用是胃肠管间质瘤分子靶向治疗的里程碑.本文就胃肠管间质瘤基因突变和分子靶向治疗的研究进展概述.     

DOG1与胃肠道间质瘤关系的研究进展

FLJ10261(TEME16A)是新近发现的与胃肠道间质瘤(GISTs)关系密切的一个基因,由该基因编码的蛋白质DOG1,特异性表达于GISTs中,免疫组化及原位杂交证实,其阳性表达较KIT和PDGFRA更弥漫、更具有特异性,因此可能作为胃肠道间质瘤治疗的另一个靶点。笔者对DOG1与GISTs关系的研究进展进行综述。     

KRAS与BRAF基因在胃肠间质瘤中的突变情况及临床意义

目的检测KRAS与BRAF基因在胃肠间质瘤(GIST)中的突变情况并探讨其在伊马替尼耐药中的意义。方法回顾性选择2002–2012年期间在北京大学肿瘤医院就诊的519例GIST患者,其中381例c-kit或PDGFRA突变型GIST,119例c-kit或PDGFRA野生型GIST,19例含伊马替尼耐药前后配对标本病例;检测全部肿瘤组织的KRAS外显子2与BRAF外显子15的突变情况,并收集突变患者的临床特征与生存状况。结果 KRAS基因在119例c-kit或PDGFRA野生型GIST中突变率为1.7%(2/119),突变类型分别为G12D与G12C;BRAF~(V600E)突变率也为1.7%(2/119);在c-kit或PDGFRA突变型GIST与19对耐药前后GIST配对标本中均未能检测到KRAS与BRAF基因错义突变。2例KRAS基因突变的GIST患者中1例伊马替尼原发耐药,另1例伊马替尼治疗仅获得8个月的无进展生存期;2例BRAF基因突变患者均接受肿瘤完整切除,1例中危患者术后未接受辅助治疗,截至末次随访时间获得47个月的无复发生存,另1例高危患者接受伊马替尼辅助治疗2年,截至末次随访时间,已获得7年无复发生存。结论野生型GIST患者可发生KRAS与BRAF基因低频率的突变,KRAS基因突变可能与伊马替尼原发耐药有关;继发耐药患者中未见新发的KRAS与BRAF基因突变。     

琥珀酸脱氢酶缺陷型胃肠间质瘤研究进展

琥珀酸脱氢酶（SDH）缺陷型胃肠间质瘤（GIST）是一类没有KIT/PDGFRA突变的野生型GIST，以SDHB免疫组化阴性为特征。SDH缺陷导致细胞内琥珀酸堆积，后者作为促癌代谢物可引发多种表观遗传学和代谢改变，促进肿瘤发生发展。SDH缺陷型GIST发病年龄早，病变部位以胃为主，可合并发生副神经节瘤或肺软骨瘤。该型GIST以手术治疗为主，对靶向治疗反应欠佳，替莫唑胺等传统化疗药物可能对其有潜在疗效。SDH缺陷型GIST的发病机制及有效治疗方法等仍有待进一步探索。     

骶前间质瘤1例并文献复习

胃肠道间质瘤(gastrointestinal stromal tumors,GIST)是一种间叶源性肿瘤,1983年MazurClark首次提出此概念,将其定义为起源、生物学行为均不明的胃肠道梭形细胞肿瘤,由未成熟的间充质细胞分化为Cajal(ICC)细胞所形成[1-4]。有部分学者认为,这可能与基因KIT或PDGFRA的突变有关,也有少数GIST存在BRAF、RAS家族基因和NF1基因的突变[5-11]。其可发生于胃肠道各个部位,以胃和小肠最为多见,也可见于结直肠、盲肠及食管[12]。极少部分可发生于腹膜、肠系膜及胰腺等[13],称为“胃肠道外间质瘤(extra-gastrointestinal stromal tumors,EGIST)”。其平均发病年龄在55~60岁,发病性别无明显差异[14]。本文描述了1例骶前EGIST的诊治过程,并结合相关文献进一步探讨。     

胃肠间质瘤危险度评估系统比较——从NIH共识标准到预后等高热线图

正胃肠间质瘤(gastrointestinal stromal tumor,GIST)是胃肠道最常见的间叶源性肿瘤,由突变的KIT或血小板源性生长因子受体α(PDGFRA)基因驱动,其生物学行为多样,可表现为良性、恶性潜能未定或恶性~[1]。在当前的临床实践中,多采用对完全切除的原发GIST进行危险度分级,以评估特定病例的复发或转移风险(进展风险),并指导术后辅助治疗(靶向治疗)的选择~[2-5]。     

胃肠道间质瘤的临床病理特征及其与预后的关系

胃肠道间质瘤（gastrointestinal stromal tumors．GIST）是最常见的消化道间叶源性肿瘤，以KIT或血小板衍化生长因子受体仪基因突变为主要发病机制。本研究的目的是探讨胃肠道间质瘤的临床病理特征及其与预后的关系。     

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.     

Reduction of Plasma Fibrinogen, Immunoglobulin G, and Immunoglobulin M Concentrations by Immunoadsorption Therapy with Tryptophan and Phenylalanine Adsorbents

Abstract Immunoadsorption (1A) therapy with tryptophan (TR-350) or phenylalanine (PH-350) adsorbents has been used to reduce the concentration of serum antibodies in human lymphocyte antigen (HLA)-immunized patients. Other forms of plasma purification have been reported to reduce the level of fibrinogen, which affects the blood properties. In this study we investigated the effects of IA therapy using both adsorbents on plasma fibrinogen and immunoglobulins G and M in 13 patients (8 patients were treated with TR-350, and 5 patients were treated with PH-350). During each session 1 plasma volume (2.8 ± 0.4 L of plasma) was processed through the immunocolumn and then returned to the patient together with the blood cells. Compared with the pretreatment values, the plasma fibrinogen, IgG, and IgM concentrations were significantly reduced after IA therapy (p < 0.01 for TR-350; p < 0.04 for PH-350). There was a positive correlation between the degree of reduction of plasma proteins and the number of IA treatments given. A nonpara-metric test (Wilcoxon's signed-rank test or the Mann-Whitney test) was used for statistical analysis. We conclude from our study that IA therapy effectively lowers the plasma levels of fibrinogen, IgG, and IgM and thus can be considered a valuable alternative to other blood purification methods.     

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.