骨形态发生蛋白-7的研究进展

骨形态发生蛋白-7(BMP-7)作为骨形态发生蛋白家族成员,能刺激未分化细胞定向分化为成骨细胞,调节骨发育,具有较强的骨诱导活性,能够在体内、体外诱导骨、软骨形成完成骨修复能力。BMP-7能完善移植骨的机械性能和功能,增强同种异体移植物的脊柱融合作用。除了在骨科中的应用外,BMP-7在口腔疾病和肾脏疾病中的应用日广。BMP-7在齿、牙槽骨的发育和重建中可发挥骨诱导作用,诱导牙髓牙本质的再生,从而减轻炎症反应。BMP-7在肾脏高度表达,能够保护肾小球完整性,具有抗肾脏纤维化作用。     

骨形态发生蛋白介导的Smad依赖途径和Smad非依赖途径对骨质疏松症的潜在调节作用研究进展

糖皮质激素长期使用、雌激素减少、继发性甲状旁腺功能亢进、骨组织微环境改变等多种因素均可诱发骨质疏松症。骨代谢失衡(成骨-成脂失衡)是骨质疏松症发病的关键机制,而骨髓间充质干细胞分化为脂肪细胞增加和成骨细胞减少是导致骨质疏松症成骨-成脂失衡的核心。骨形态发生蛋白(bone morphogenesis protein,BMP)则是调控骨质疏松症成骨-成脂平衡的关键蛋白,而这一调控作用又是通过Smad依赖途径和Smad非依赖途径来实现的。本文重点介绍了BMP介导的Smad依赖途径和Smad非依赖途径,并详细介绍了BMP-2、BMP-4、BMP-6、BMP-7、BMP-9通过上述途径参与骨质疏松症成骨、成脂代谢调控的可能机制,以期为临床抗骨质疏松症药物有效靶点的筛选提供新思路。     

人骨形成蛋白2和地塞米松对不同来源成骨细胞的作用

目的：观察不同浓度的人骨形成蛋白2(BMP-2)和地塞米松(DEX)对3种来源成骨细胞的作用，并比较其特性。方法：体外培养胰酶消化法所得的正常成人的成骨细胞，成骨样细胞系和由骨髓单个核细胞(MNC)经DEX诱导7d后所得的成骨细胞，经不同浓度的BMP-2和DEX处理，观察细胞形态，并进行MTT试验和测定细胞裂解液的碱性磷酸酶(ALP)。结果：对正常成人的成骨细胞，BMP-2处理48h，72h对第4代和第8代的细胞无明显促增殖和分化作用；DEX作用48h和72h促第4代细胞增殖且表达ALP明显增加，DEX浓度为10^-8mol／L时其促增殖和分化的效果最佳，DEX对第8代细胞无明显作用。对成骨样细胞系BMP-2促增殖作用不明显，DEX处理48，72h后明显促其增殖；BMP-2及DEX作用72h后ALP表达明显增加，当作用于源自骨髓MNC的成骨细胞48，72h均促其增殖和分化。结论：BMP-2和DEX对不同成骨细胞的效应因细胞来源和作用时间不同而有差别。     

鲑鱼降钙素对小鼠MC3T3-E1细胞BMP-2蛋白表达的影响

目的通过不同深度的鲑鱼降钙素对骨形态发生蛋白的变化,研究鲑鱼降钙素改善骨质疏松与成骨细胞关系。方法采用纯化的小鼠MC3T3-E1细胞,随机分为对照组、低剂量组鲑鱼降钙素2.5 ng/mL、中剂量组:鲑鱼降钙素5 ng/mL、高剂量组:鲑鱼降钙素10 ng/mL,加药24 h后,采用蛋白质印迹分析BMP-2蛋白表达和活性。结果各浓度鲑鱼降钙素与对照组相比,BMP-2活性明显高于对照组,其中低剂量组(0.5620±0.020)与对照组(0.5386±0.028),中剂量组(0.6228±0.012)与对照组(0.5386±0.028)相比蛋白含量有增高,但无统计学意义。高剂量(0.7813±0.010)与对照组(0.5386±0.028)相比蛋白含量明显增高,且有统计学意义(P<0.05)。结论鲑鱼降钙素可以通过刺激BMP-2蛋白表现,促进成骨细胞增殖改善骨质疏松。     

骨形成蛋白-2对人肝癌细胞系Huh7生长的影响

骨形成蛋白（bone morphogenetic proteins,BMPs）属于肿瘤坏死因子（TGF）-β超家族,1965年首次被发现并因其具有诱导骨形成的能力而得名.BMPs可调节细胞增殖、分化及凋亡,尤其在胚胎机体发育过程中对组织器官形态发生,在成年机体生长过程中对组织器官形态的维持起重要作用.此外,BMPs与疾病发生特别是肿瘤发生有关,在一些非骨源性肿瘤中也发现有BMPs表达,有研究显示BMP-9在人肝癌细胞系HepG2细胞中表达,BMP-9促进HepG2细胞的生长.     

骨形态发生蛋白的骨诱导活性及其应用研究现状

早在 1 965年Urist[1] 报道了用脱钙骨基质可以异位诱导宿主的间充质细胞分化成新骨 ,这一实验结果提示在骨基质中可能含有一种活性蛋白质 ,具有使未分化的间充质细胞定向分化为成骨细胞并具有形成骨组织的能力 ,人们后来将它命名为骨形态发生蛋白 (bonemorphogeneticproteins,BMPs)。随着分子生物学在骨形成和损伤修复方面的研究进展 ,人们逐渐认识到了多种因子参与骨再建时的细胞增生、分化以及基质合成的调节 ,而在众多的骨生长因子中 ,BMPs最受瞩目 ,与骨诱导的关系最为密切[2 ] ,同时是胚胎时期重要的诱导分化因子之一。这种蛋白质…     

盐酸二甲双胍对成骨细胞增殖、BMP-2及Cbfa-1基因表达的影响

目的初步研究二甲双胍（MF）在体外对小鼠颅盖骨成骨细胞增殖、骨形态发生蛋白一2（BMP一2）及核心结合因子（Cbfa一1）mRNA表达的影响,探讨二甲双胍对骨代谢的可能作用机制。方法（1）分离培养原代颅盖骨成骨细胞并对其进行鉴定。（2）以乳鼠成骨细胞为体外实验模型,不同浓度（0、50、100、200、400Ixmol／L）的MF干预体外培养的成骨细胞24h后,M1vr法检测成骨细胞的增殖能力,实时荧光定量PCR法检测成骨细胞BMP-2及Cbfa-1基因表达。结果二甲双胍干预成骨细胞24h后,可促进成骨细胞的增殖,在浓度400μxmol／L的OD值最大为0．298±0．047（P〈0．05）;可促进BMP-2及Cbfa-1mRNA的表达,呈剂量效应关系。结论二甲双胍可促进成骨细胞的增殖和分化,可能通过调节BMP-2及Cbfa-1的表达,从而促进骨的形成。     

糖尿病大鼠骨折愈合过程中 VEGF、BMP-2及BMP-7的动态观察

目的：动态观察糖尿病模型大鼠骨折愈合过程中的血管内皮细胞生长因子（ VEGF）、骨形态发生蛋白-2（BMP-2）、骨形态发生蛋白-7（BMP-7）的变化趋势,探索影响糖尿病骨折愈合的机制。方法选取Wester 雄性大鼠70只,采用随机数字表法分为糖尿病组[（腹腔注射链脲佐菌素（ STZ）造模]和对照组,每组35只。采用线锯锯断2组大鼠的左侧胫骨,采用外固定复位处理,观察2组大鼠术后第1、3、5、7周的血清及骨痂中VEGF、BMP-2、BMP-7的表达变化。结果糖尿病组大鼠术后第1周、术后第3周的VEGF、BMP-2、BMP-7的表达水平均显著低于对照组（ P＜0构．05）,术后第5、第7周2组大鼠骨痂组织中的VEGF、BMP-2、BMP-7的表达水平差异无统计学意义（ P ＞0．05）。糖尿病组与对照组大鼠的血清中VEGF、BMP-2、BMP-7在术后第1～7周差异无统计学意义（ P ＞0．05）,糖尿病大鼠术后第1、第3周BMP-7的表达水平显著低于对照组大鼠,差异有统计学意义（ P ＜0．05）。结论糖尿病大鼠血清、骨痂组织中BMP-7、BMP-2及VEGF表达减少可能是其延迟愈合的一个重要原因。     

富血小板纤维蛋白对牵引成骨区BMP-6表达的影响

目的 探讨应用富血小板纤维蛋白（platelet-rich fibrin,PRF）对牵引成骨区骨形态发生蛋白-6（bone morphogenetic protein 6,BMP-6）表达的影响。方法 25只大耳白兔随机分5组,分别行双侧下颌骨皮质骨切开术,一侧下颌骨牵引间隙放置PRF膜,作为实验组,对侧作为对照组,分别于稳定期第1、3、7、14、28天处死一组动物,切取牵引间隙处骨痂行HE染色和BMP-6免疫组织化学染色,细胞图像分析仪测量牵引间隙处骨痂BMP-6表达情况。结果 下颌牵引延长后牵引间隙均有新骨形成,免疫组化染色BMP-6主要定位于成骨细胞的胞浆中。实验组在稳定期1、3、7天BMP-6表达的阳性细胞率和阳性面积百分比均高于对照组（P＜0.05）,稳定期14、28天BMP-6表达的阳性细胞率和阳性面积百分比均与对照组比较差异无统计学意义。结论 PRF能促进兔下颌骨牵引成骨区新骨的生成,BMP-6可能在牵引成骨过程的早期调控组织细胞应力信号传递,发挥成骨作用。     

葛根异黄酮对去卵巢大鼠的抗骨质疏松作用及其机制

目的研究葛根异黄酮对去卵巢大鼠抗骨质疏松的作用机制。方法选择3月龄健康雌性Wister大鼠60只,随机分为假手术组、模型组、尼尔雌醇组、葛根异黄酮低、中和高剂量组等6组,每组10只。假手术和模型组灌胃给予0.5%CMC-Na溶液;尼尔雌醇组灌胃给予尼尔雌醇0.5 mg/kg,每周2次(周一和周四);葛根异黄酮低、中和高剂量组分别灌胃给予葛根异黄酮25,50,和100 mg/kg,时间均为70 d。采用ELISA法测定血清细胞因子IL-6、IGF-1水平;免疫组化法测定颅骨成骨细胞骨形态发生蛋白-2(BMP-2)的表达;双能X线骨密度仪测量股骨中点及远心端骨密度。结果葛根异黄酮能明显的增加股骨中点及远心端骨密度(P<0.05),升高血清IGF-1的水平(P<0.05),降低血清IL-6的水平(P<0.01),并且能较好的增加成骨细胞BMP-2表达水平(P<0.01)。结论葛根异黄酮能够改善骨质疏松,作用机制可能通过下调IL-6表达水平和提高成骨细胞BMP-2的表达实现的。     

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.     

Pharmacological treatment of COVID-19: an opinion paper

The precocity and efficacy of the vaccines developed so far against COVID-19 has been the most significant and saving advance against the pandemic. The development of vaccines has not prevented, during the whole period of the pandemic, the constant search for therapeutic medicines, both among existing drugs with different indications and in the development of new drugs. The Scientific Committee of the COVID-19 of the Illustrious College of Physicians of Madrid wanted to offer an early, simplified and critical approach to these new drugs, to new developments in immunotherapy and to what has been learned from the immune response modulators already known and which have proven effective against the virus, in order to help understand the current situation.     

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.