骨髓干细胞动员疗法对心肌梗死大鼠心肌的促血管生成作用

目的探讨骨髓干细胞动员疗法对心肌梗死大鼠冠状动脉新生血管形成的影响。方法结扎Wistar大鼠左冠状动脉制作急性心肌梗死（AMI）模型,人参皂甙Rg1联用辛伐他汀动员自体骨髓干细胞,建模后第24h、1周和4周时杀死大鼠,取出心脏,HE染色检测梗死面积,免疫组化方法观察心肌梗死灶、边缘区和正常心肌组织CD34阳性细胞及Ⅷ因子表达。结果人参皂甙Rg1联用辛伐他汀治疗后,治疗组大鼠心肌梗死区可见CD34阳性细胞浸润;治疗组大鼠梗死面积明显减小;治疗组大鼠梗死灶及周围组织中微血管密度明显高于AMI组及假手术对照组。结论在大鼠AMI模型中,人参皂甙Rg1联用辛伐他汀治疗,可动员骨髓干细胞归巢于缺血心肌,有效促进微血管形成,促进缺血心脏功能恢复。     

CD34+细胞在急性心肌梗死周边区表达的研究

目的探讨动员骨髓干细胞后CD34 细胞在急性心肌梗死微环境周边区中的表达。方法制备大鼠心肌梗死模型,通过心肌病理组织学及免疫组织化学检测,评价动员的骨髓干细胞对心肌梗死后24h、7d及14d的治疗作用,并对其机制进行探讨。结果24h及7d动员组检测CD34 阳性心肌细胞(个/HP)与对照组相比,分别为(2.90±0.87比1.10±0.88;8.30±1.83比1.40±0.51,P<0.05),且动员组CD34 细胞数7d与24h比较(个/HP)(8.30±1.83比2.90±0.87,P<0.05)明显增加;7d时,动员组与对照组缺血周边区均有B r-dU免疫阳性细胞,与对照组比(个/HP),B rdU标记阳性细胞数明显增多(7.90±1.37比1.30±0.67,P<0.05);14d时,对照组可见大量心肌瘢痕组织;而动员组瘢痕组织面积明显小于对照组,部分血管壁上可见小核深染的细胞附着,并沿血管壁移行,14d时CD34 细胞均变为阴性反应。结论动员的骨髓干细胞对大鼠缺血心肌有治疗作用,其机制可能是在心肌微环境中,动员的骨髓干细胞(包括CD34 细胞)有向心肌细胞、血管内皮细胞分化的潜能。     

粒细胞集落刺激因子对心肌梗死大鼠心肌T细胞亚群的影响

目的:探讨粒细胞集落刺激因子(G-CSF)对心肌梗死大鼠心肌T淋巴细胞亚群的影响。方法:29只大鼠随机分为干细胞动员组(GAMI,n=9)、心肌梗死对照组(AMI,n=10)和假手术组(SO,n=10)。GAMI组和AMI组结扎左冠状动脉造成心肌梗死,SO组行相似的手术操作但不结扎冠状动脉。GAMI组给予rhG-CSF(50μg·kg-1·d-1),皮下注射,共7d。AMI组及SO组则每日皮下注射同等体积的生理盐水,共7d。心肌梗死后4周,通过免疫组化染色检测心肌CD3 、CD4 和CD8 细胞计数并计算CD4 /CD8 比率。结果:AMI组大鼠有3只分别于术后第3、7、8天死亡,GAMI组与SO组大鼠至观察结束无一只死亡。与AMI组相比较,GAMI组CD3 和CD8 细胞计数降低(均P<0.01),CD4 细胞计数无明显变化(P>0.05),CD4 /CD8 比率升高(P<0.01)。结论:G-CSF可降低心肌梗死后大鼠心肌CD3 和CD8 T淋巴细胞计数、升高CD4 /CD8 比率,提示G-CSF可减轻心肌梗死后的免疫损伤。     

雌激素对心肌梗死大鼠外周血干细胞及血管生成的影响

目的探讨雌激素对急性心肌梗死大鼠外周血干细胞和心肌血管生成的影响。方法结扎去卵巢SD大鼠左冠状动脉制作急性心肌梗死模型,给予苯甲酸雌二醇干预治疗,分别于急性心肌梗死24h后免疫组化法检测归巢心肌的CD34+细胞数量;于d1、3、7流式细胞术测定外周血CD34+细胞数,免疫组化法测定心肌中基质细胞衍生因子(stromalcell-derivedfactor,SDF-1)的表达,分析心梗4wk后心肌组织中毛细血管密度判断血管新生情况。结果与卵巢完整大鼠相比,去卵巢大鼠心梗后外周血和心肌组织中CD34+细胞数、SDF-1的表达和4wk后毛细血管密度明显降低,雌激素干预各组上述指标明显升高,其中,雌激素替代组最高。结论雌激素可促进大鼠心肌梗死后外周血骨髓干细胞的动员和归巢,增加毛细血管密度,改善预后,其机制可能与提高心肌SDF-1表达有关。且采用心肌梗死前雌激素替代疗效优于心肌梗死后雌激素治疗     

骨髓干细胞动员对心肌病心衰大鼠的心功能影响

目的:探讨骨髓干细胞动员对心肌病心衰大鼠的心功能影响。方法:选取20只心肌病心衰模型,随机分成两组,骨髓干细胞动员组(G组)为皮下注入重组人粒细胞刺激因子,心衰组皮下注入生理盐水。治疗前后采静脉血测外周血白细胞计数和单个核细胞数,将治疗5d后外周血分离出单个核细胞用流式细胞仪测CD34。四周后由彩色超声心动图评价心功能参数。结果:骨髓动员组外周血白细胞计数和单个核细胞数明显增高,流试细胞仪检查CD34阳性。在治疗4周后G组在超声心动图与心衰组有差异明显。结论:骨髓干细胞动员动员出造血干细胞,G组对心肌病心衰大鼠的心功能有明显改善。     

基质细胞衍生因子1在骨髓间质干细胞归巢到急性梗死心肌中的作用

目的 探讨基质细胞衍生因子1(SDF-1)在骨髓间质干细胞(MSCs)归巢到急性梗死心肌中的作用.方法 以免疫组化检测SDF-1在心肌梗死1、2、4、7、14、28 d后的大鼠及非心肌梗死大鼠心肌中的表达差异;于心肌梗死4 d后予以SDF-1、抗SDF-1抗体进行干预,同时经尾静脉注射BrdU标记的MSCs,3 d后检测梗死区MSCs的归巢量,28 d后检测大鼠心功能状况,以及梗死区及其周围的血管密度;另设心肌梗死及非心肌梗死阴性对照组.结果 SDF-1在心肌梗死后第1天即升高并达到峰值,以后逐渐下降,第14天恢复至正常水平.心肌梗死组干细胞归巢量明显大于非心肌梗死对照组.SDF-1处理组大鼠心肌梗死区干细胞归巢量、心功能水平及血管密度大于抗SDF-1抗体处理组及心肌梗死对照组(P＜0.01).结论 心肌梗死后早期梗死区SDF-1表达水平升高;SDF-1能够促进MSCs归巢并改善心功能,促进毛细血管增生可能为其改善心功能的机制之一.     

骨髓基质细胞移植抑制缺血心肌纤维化

目的探讨骨髓基质细胞移植改善缺血心脏功能的机制。方法制作F344大鼠心肌梗死模型,将分离培养的骨髓基质细胞移植于心梗周边区（治疗组）,取1、3、5、7、9、15d后缺血心肌切片,通过免疫组织化学染色及免疫荧光染色检测波形蛋白的表达,了解梗死心肌纤维化程度,并应用血液动力学在术后各时间点检测大鼠心脏功能的变化。结果治疗组心功能较同期对照组明显改善。术后7、9、15d治疗组缺血心肌纤维化程度较同期对照组明显减轻。结论骨髓基质细胞移植于缺血心肌后明显改善缺血心脏功能。其机制之一可能是抑制缺血心肌的纤维化,延缓心室重构。     

骨髓间充质干细胞移植改善缺血心脏功能

目的 探讨骨髓间充质干细胞移植改善缺血心脏功能的机制.方法 以近交系F344大鼠为研究对象,结扎冠状动脉制作大鼠心肌梗死模型,1周后将BrdU标记的骨髓间充质干细胞移植于心梗缺血区,4周后缺血心肌切片,通过免疫组织化学染色检测BrdU、闰盘连接蛋白(connexin 43,Cx 43)、肌球蛋白重链β(MHC)、平滑肌肌动蛋白(α-SMA)的表达,了解移植细胞的分化情况,并应用超声检测大鼠心脏功能的变化.结果 超声检查显示治疗组心功能明显改善,心脏射血分数(EF)值增加了(27.85±4.00)%,而对照组减少了(1.98±2.87)%,差异有统计学意义.心肌缺血区内可见到BrdU标记的移植细胞,相当一部分移植细胞已分化为MHC和Cx 43染色阳性的心肌样细胞.同时,治疗组功能血管密度较对照组明显增加.结论 骨髓间充质干细胞移植于缺血心肌后可分化为心肌样细胞,参与改善缺血心脏的功能.     

黄芪皂苷Ⅳ对缺血大鼠心肌钙运转和心功能的影响(英文)

目的:研究黄芪皂苷IV(XGA)对缺血大鼠心肌钙运转和心功能的影响.方法:84只Wistar大鼠分为3组:对照组(12只);缺血组(12只),皮下注射异丙肾上腺素(30 mg/kg);XGA组(60只),皮下注射异丙肾上腺素后给予XGA.测定大鼠血流动力学指标、心脏功能和心肌细胞内外钙的变化,观察XGA对缺血大鼠心肌钙运转和心功能的量-效和时-效关系.结果:给予XGA后缺血大鼠心功能和血流动力学明显改善,随着XGA剂量的增加和XGA作用时间的延长,缺血大鼠的心输出量、心率、每博量、平均动脉压、动脉收缩压、左心室搏出功、左室和右室收缩末期压力和右心室的 dp/dt逐渐恢复到对照组水平;给予XGA后心肌细胞游离钙和心肌组织总钙与缺血组比较明显下降,而红细胞膜钙泵活性较缺血组明显增加,但心肌细胞游离钙和心肌组织总钙下降的幅度及红细胞膜钙泵活性增加的幅度并没有随XGA剂量的增加而增加;随XGA作用时间的延长,心肌细胞游离钙逐渐下降.结论:XGA能够明显改善缺血大鼠的心功能,减少心肌细胞内过多的钙积聚是其作用机制之一.     

激活Notch信号的骨髓间充质干细胞心肌移植促进血管新生

目的探讨干预Notch信号骨髓间充质干细胞(BMSCs)移植对心肌梗死(MI)大鼠心肌的治疗性血管新生作用及其机制。方法 60只Wistar大鼠经结扎冠状动脉前降支建立MI模型后2周进行相应处理后,随机分为激活Noth信号的BMSCs移植实验组(D组)、BMSCs移植对照组(E组)、培养液移植对照组(C组)、MI模型对照组(B组),每组15只;另选取10只为假手术对照组(A组)。4周后观察细胞生长及增殖情况,测定缺血心肌中血管内皮细胞生长因子(VEGF)蛋白的表达及缺血区心肌毛细血管密度的改变。结果 BMSCs在梗死区中可增殖分化为内皮细胞。与B组、C组及A组相比,D组、E组缺血心肌中VEGF蛋白的表达增多及毛细血管密度均明显增高(P<0.01),D组较E组更明显(P<0.05)。结论 Notch信号促进心肌梗死区BMSCs向内皮细胞分化,促进缺血心肌中毛细血管新生。     

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.     

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.     

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.     

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.