c-myc基因在脑星形细胞瘤中的表达

目的 :探讨 c- myc在人脑星形细胞瘤中的表达。方法 :应用免疫组化方法检测 5 0例人脑星形细胞瘤和 6例正常脑组织石蜡标本中 c- myc的表达。结果 :随着病理级别的升高 ,c- myc阳性率逐渐升高 ,二者之间呈正相关(r=0 .70 9,P<0 .0 1) ,I～ 和 ～ IV级比较 ,有显著差异 (χ2 =6 .2 11,P <0 .0 5 )。结论 :c- myc的检测可作为判断星形细胞瘤分化及恶性程度重要的参考指标 ,c- myc在细胞周期中发挥重要作用     

MIC-1、PCNA在人脑星形细胞瘤中的表达及意义

目的研究巨噬细胞抑制因子-1(MIC-1)与增殖细胞核抗原(PCNA)在人脑星形细胞瘤中的表达,分析其表达水平与肿瘤恶性程度及病理级别的关系。方法采用免疫组化法,检测60例不同病理级别人脑星形细胞瘤标本及5例正常人脑组织中的MIC-1和PCNA的表达。结果 MIC-1和PCNA在正常脑组织中不表达,而在人脑星形细胞瘤中的表达程度随着肿瘤的病理级别的增高明显增高,二者表达的阳性率在正常脑组织、低级别和高级别星形细胞瘤各组间比较差异均有统计学意义(P<0.05),且二者在星形细胞瘤中的表达呈正相关(P<0.05)。结论 MIC-1与PCNA在人脑星形瘤细胞中的表达呈正相关,提示MIC-1的过度表达对肿瘤细胞增殖具有促进作用,MIC-1有可能成为新的候选肿瘤标志物,为判断肿瘤恶性程度及病理级别提供有价值的理论和依据。     

人脑星形细胞瘤中Survivin和FHIT的表达及相关性研究

目的:探讨Survivin和FHIT蛋白在人脑星形细胞瘤的表达及相互关系。方法:采用免疫组织化学方法分别检测人脑星形细胞瘤细胞中Survivin和FHIT的表达,并且结合病理分级分析其相关关系。结果:随着人脑星形细胞瘤病理分级的增高,Survivin的表达明显升高,FHIT的表达明显降低,存在显著性差异,人脑星形细胞瘤中Survivin和FHIT的表达存在相关性。结论:在人脑星形细胞瘤中Survivin和FHIT异常表达;星形细胞瘤的发生和演变可能与Survivin和FHIT的综合作用密切相关。     

增殖细胞核抗原与表皮生长因子受体在脑星形细胞瘤中的表达及其意义

目的:研究增殖细胞核抗原(PCNA)与表皮生长因子受体(EGFR)在人脑星形细胞瘤中的表达及与星形细胞瘤病理分级的关系。方法:利用免疫组化方法检测44例星形细胞瘤病理蜡块中PCNA与EGFR蛋白的表达水平并比较二者的相关性及其与星形细胞瘤病理分级的关系。结果:PCNA表达强度随星形细胞瘤病理级别的升高而升高,两者呈显著正相关(r=0.8801,P<0.05)。Ⅲ~Ⅳ级与Ⅰ~Ⅱ级、正常脑组织相比,差异有显著性(P<0.01)。随着星形细胞瘤病理级别的升高EGFR蛋白的表达率逐渐升高,Ⅰ~Ⅳ级阳性率分别为11.1%、33.3%、63.6%、75.0%。二者之间呈正相关(r=0.6597,P<0.05)。Ⅲ~Ⅳ级与Ⅰ~Ⅱ级、正常脑组织相比,差异有显著(P<0.01)。而PCNA的评分与EGFR的表达状况无显著相关性(χ2=17.11,P>0.05)结论:PCNA与EGFR的免疫组化检测有利于判断星形细胞瘤的发生发展、恶性程度及增殖性,为临床上对该肿瘤的诊断、鉴别诊断、治疗及预后判定提供了重要的参考指标     

过氧化物酶体增殖物激活受体γ在正常人脑和脑星形细胞瘤组织中的表达

目的探讨过氧化物酶体增殖物激活受体（PPAR）γ在正常人脑组织和人脑星形细胞瘤组织中表达的差异。方法应用半定量RT-PCR法和免疫组织化学检测正常脑组织、不同分化级别人脑星形细胞瘤组织标本中PPARγ表达。结果PPARγmRNA和PPARγ蛋白在正常人脑组织、人脑星形细胞瘤中均可表达,且人脑星形细胞瘤中的表达显著高于正常脑组织（P〈0．05）,其中,Ⅰ～Ⅱ级组和Ⅲ～Ⅳ级组的表达均显著高于正常脑组织（P〈0．05）;Ⅲ～Ⅳ级组的表达显著高于Ⅰ～Ⅱ级组（P〈0．05）。结论PPARγ在人脑星形细胞瘤和正常脑组织中均表达,与人脑星形细胞瘤的病理分级有关,可能参与人脑星形细胞瘤的发生、发展过程。     

人脑星形细胞瘤STAT3的表达及意义

目的探讨STAT3在人脑星形细胞瘤发生发展中的作用。方法应用免疫组化二步法检测53例不同级别星形细胞瘤和10例正常脑组织中STAT3及P-STAT3的表达。结果 STAT3、P-STAT3的表达阳性率在正常脑组织及星形细胞瘤中差异有极显著性(P均<0.01);且STAT3、P-STAT3的表达与星形细胞瘤病理级别正相关(P均<0.05),与临床病理特征无关。结论 STAT3及P-STAT3可作为判断星形细胞瘤恶性程度的依据,在星形细胞瘤的发生发展中可能有着重要的作用。     

星形细胞瘤中p15与p27基因的表达及相关性研究

目的 探讨p15与p27基因与星形细胞瘤发生、发展,恶性程度的关系.方法 采用S-P免疫组化法染色观察50例人星形细胞瘤组织中p15和p27基因蛋白的表达情况.结果 p27基因在低级别及高级别星形细胞瘤平均阳性细胞百分率分别为(38.16±10.79)%、(11.00±3.24)%.p15基因在低级别与高级别星形细胞瘤平均阳性细胞百分率分别为(32.53±12.46)%、(10.50±2.01)%.结论 p15与p27基因蛋白的平均阳性细胞百分率与星形细胞瘤的病理分级和恶性程度有密切关系,可能在星形细胞瘤发生,发展中起重要作用.     

星形细胞瘤中IGF2的表达及临床意义

目的 检测人脑星形细胞瘤及瘤旁组织中IGF2的表达,并研究其与患者临床特征关系.方法 收集贵州省人民医院病理科星形细胞瘤组织标本143例和90例星形细胞瘤旁组织,采用免疫组化S-P二步法检测IGF2的表达情况,并结合相关临床因素进行统计学分析.结果 IGF2在瘤旁组织中低表达,阳性率为13.3％(12/90);在星形细胞瘤低级别组和高级别组中均不同程度阳性表达,阳性率分别为46.8％(29/62),64.2％(52/81),且高级别组中表达与水平均显著高于低级别组(x2 =4.341,P＜0.05).结论 IGF2的表达星形细胞瘤病理级别及患者预后关系密切.IGF2的检测可能成为胶质瘤生物标记的新指标.     

星形细胞瘤PTEN的表达及其与EGFR相关性的研究

目的检测PTEN和EGFR在星形细胞瘤中的表达,探讨二者表达的意义。方法采用免疫组织化学SP法检测星形细胞瘤二者的表达,应用SSPS10·0统计软件进行数据处理。结果PTEN在星形细胞瘤Ⅰ、Ⅱ、Ⅲ、Ⅳ级中阳性率分别为100%、76·2%、54·5%、33·3%,PTEN表达阳性率随病理分级升高而降低(χ2=23·480,P<0·01)。EGFR表达水平与PTEN表达水平呈负相关(rs=-0·388,P=0·002)。结论在星形细胞瘤的发生、发展过程中PTEN可能起到抑制作用,EGFR、PTEN互相起拮抗作用。     

PCNA、HSP70在星形胶质细胞瘤中的表达及其临床意义

目的:研究增殖细胞核抗原(PCNA)、热休克蛋白70(HSP70)在星形胶质细胞瘤中的表达及其临床意义。方法:采用免疫组化SP法对43例人脑胶质瘤石蜡标本中PCNA、HSP70进行检测。标本均为星形胶质细胞瘤,病理级别为Ⅰ~Ⅳ级。观察其与胶质瘤临床病理分级的关系及其相关性。结果:PCNA和HSP70在脑星形细胞瘤中的表达程度明显增高,并且发现二者表达的阳性率随着胶质瘤病理级别的升高而升高,不同级别之间存在显著性差异,二者呈正相关。结论:检测脑胶质瘤组织中PCNA、HSP70表达能够快速、准确地反映肿瘤细胞的增殖状态及评价预后,对判定胶质瘤的恶性程度及指导治疗有一定意义。     

Efficacy of gut lavage,hemodialysis, and hemoperfusion in the therapy of paraquat or diquat intoxication

Clinical and in vitro investigations were carried out to test the efficacy of gut lavage, hemodialysis, and hemoperfusion in the treatment of poisoning with paraquat or diquat. In a patient suffering from diquat intoxication 130 times more diquat was removed by gut lavage 30 h after ingestion than was removed by complete aspiration of the gastric contents.Determination of in vitro clearances for paraquat and diquat by hemodialysis showed that, at serum concentrations of 1–2 ppm, such as are frequently encountered in poisoning in man, toxicologically relevant quantities of herbicide cannot be removed from the body. At a concentration of 20 ppm, on the other hand, hemodialysis proved to be effective, the clearance being 70 ml/min at a blood flow rate of 100 ml/min. The efficacy of hemoperfusion with coated activated charcoal was on the whole better. Especially at concentrations around 1–2 ppm, the clearance values for hemoperfusion were some 5–7 times higher than those for hemodialysis.In a patient suffering from paraquat poisoning, both hemodialysis as well as hemoperfusion were carried out. The in vitro results could be confirmed: At serum concentrations of paraquat less than 1 ppm no clearance could be obtained by hemodialysis while by hemoperfusion with activated charcoal quite high clearance values were measured and the serum level dropped down to zero.

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Zusammenfassung Klinische Untersuchungen und Laboratoriumsversuche wurden durchgeführt, um die Wirksamkeit von Darmspülung, Hämodialyse und Hämoperfusion bei Paraquat- und Deiquat-Vergiftungen zu prüfen.Bei einem Patienten wurde 30 Std nach Deiquat-Aufnahme durch Darmspülung 130mal mehr Deiquat entfernt als durch vollständige Aspiration des Mageninhaltes. In vitro-Versuche ergaben, daß bei Blutserumkonzentrationen von 1–2 ppm, die bei Vergiftungen oft gemessen werden, durch Hämodialyse keine toxikologisch relevanten Paraquat- oder Deiquat-Mengen entfernt werden können. Dagegen erwies sich die Hämodialyse bei 20 ppm und einer Blutumlaufgeschwindigkeit von 100 ml/min mit einer Clearance von 70 ml/min als wirksam. Die Hämoperfusion mit beschicheter Aktivkohle war in diesen Versuchen aber eindeutig überlegen, denn insbesondere bei Konzentrationen um 1–2 ppm waren die Clearance-Werte 5–7mal höher als bei der Hämodialyse.Die in vitro-Ergebnisse wurden bei einem Patienten mit einer Paraquat-Vergiftung bestätigt: Bei Konzentrationen unter 1 ppm war die Hämodialyse wirkungslos, während durch Hämoperfusion relativ hohe Clearance-Werte erreicht wurden, so daß der Serumspiegel rasch unter die Nachweisgrenze abfiel.

     

In vitro studies on sterically stabilized liposomes (SL) as enzyme carriers in organophosphorus (OP) antagonism

This study describes a new approach for organophosphorous (OP) antidotal treatment by encapsulating an OP hydrolyzing enzyme, OPA anhydrolase (OPAA), within sterically stabilized liposomes. The recombinant OPAA enzyme was derived from Alteromonas strain JD6. It has broad substrate specificity to a wide range of OP compounds: DFP and the nerve agents, soman and sarin. Liposomes encapsulating OPAA (SL)* were made by mechanical dispersion method. Hydrolysis of DFP by (SL)* was measured by following an increase of fluoride ion concentration using a fluoride ion selective electrode. OPAA entrapped in the carrier liposomes rapidly hydrolyze DFP, with the rate of DFP hydrolysis directly proportional to the amount of (SL)* added to the solution. Liposomal carriers containing no enzyme did not hydrolyze DFP. The reaction was linear and the rate of hydrolysis was first order in the substrate. This enzyme carrier system serves as a biodegradable protective environment for the recombinant OP-metabolizing enzyme, OPAA, resulting in prolongation of enzymatic concentration in the body. These studies suggest that the protection of OP intoxication can be strikingly enhanced by adding OPAA encapsulated within (SL)* to pralidoxime and atropine.     

Aquatic Insects and Trace Metals: Bioavailability,Bioaccumulation, and Toxicity

Abstract

The uptake of metals from food and water sources by insects is thought to be additive. For a given metal, the proportions taken up from water and food will depend both on the bioavailable concentration of the metal associated with each source and the mechanism and rate by which the metal enters the insect. Attempts to correlate insect trace metal concentrations with the trophic level of insects should be made with a knowledge of the feeding relationships of the individual taxa concerned. Pathways for the uptake of essential metals, such as copper and zinc, exist at the cellular level, and other nonessential metals, such as cadmium, also appear to enter via these routes. Within cells, trace metals can be bound to proteins or stored in granules. The internal distribution of metals among body tissues is very heterogeneous, and distribution patterns tend to be both metal and taxon specific. Trace metals associated with insects can be both bound on the surface of their chitinous exoskeleton and incorporated into body tissues. The quantities of trace meals accumulated by an individual reflect the net balance between the rate of metal influx from both dissolved and particulate sources and the rate of metal efflux from the organism. The toxicity of metals has been demonstrated at all levels of biological organization: cell, tissue, individual, population, and community. Much of the literature pertaining to the toxic effects of metals on aquatic insects is based on laboratory observations and, as such, it is difficult to extrapolate the data to insects in nature. The few experimental studies in nature suggest that trace metal contaminants can affect both the distribution and the abundance of aquatic insects. Insects have a largely unexploited potential as biomonitors of metal contamination in nature. A better understanding of the physico-chemical and biological mechanisms mediating trace metal bioavailability and exchange will facilitate the development of general predictive models relating trace metal concentrations in insects to those in their environment. Such models will facilitate the use of insects as contaminant biomonitors.     

Alzheimer’s disease – current trends in basic and clinical research. Highlights from the 16th ECNP

Advances in the molecular biological knowledge of neuronal nicotinic acetylcholine receptors (nAChRs) have led to a growing interest by the pharmaceutical industry in the development of novel compounds that selectively modulate nAChR function. The ability of (-)-nicotine, an activator of nAChRs, to enhance attentional aspects of cognition in animals and humans, to exert neuroprotective and anxiolytic-like effects, and presumably to mediate the negative correlation between smoking and Alzheimer's (and Parkinson's) Disease, has focused interest on the potential therapeutic utility of modulators of nAChR function for treatment of some of the deficits associated with these progressive, neurodegenerative conditions. Numerous compounds are known which activate nAChRs and which might serve as lead compounds toward the development of such agents. The pharmacologic diversity of neuronal nAChR subtypes suggests the possibility of developing selective compounds which would have more favourable side-effect profiles than existing agents. This broader class of agents, collectively called cholinergic channel modulators (ChCMs), is anticipated to encompass compounds which would have more favourable side-effect profiles than existing agents, which generally exhibit low selectivity. This selectivity may be achieved by preferentially activating some subtypes of nAChRs (i.e., Cholinergic Channel Activators, ChCAs) or inhibiting the function of other subtypes (Cholinergic Channel Inhibitors, ChCIs). An overview of the biology of nAChRs and the rationale for the use of ChCMs for the treatment of dementia related to neurodegenerative diseases are presented, followed by a discussion of lead compounds and compounds under consideration for clinical evaluation.     

Steroidal sapogenin contents in some domestic plants

In order to find out the values of the steroid resources for the future use. the compositions and contents of steroidal sapogenins from 13 domestic plants have been investigated. As a result,Dioscorea nipponica, D. quinqueloba andSmilax china were found to have large amount of diosgenin. And pennogenin inTrillium kamtschaticum andParis verticillata, yuccagenin inAllium fistulosum, hecogenin inAgave americana and neochlorogenin inSolanum nigum were appeared to be major steroidal sapogenins.