灵芝多糖联合二甲双胍对2型糖尿病大鼠心肌AGEs及CTGF的影响及其机制

目的探讨灵芝多糖联合二甲双胍对2型糖尿病大鼠心肌纤维化的预防作用及其作用机制。方法 SD大鼠高脂饮食喂养4周后,腹腔注射链脲佐菌素(STZ)30 mg·kg-1建立2型糖尿病(type 2 diabetes mellitus,T2DM)模型。成模后将大鼠随机分为正常对照组、模型组、灵芝多糖组(灵芝多糖600 mg·kg-1)、二甲双胍组(二甲双胍600 mg·kg-1)及联合用药组(灵芝多糖300 mg·kg-1+二甲双胍300 mg·kg-1)。药物治疗12周末测量大鼠空腹血糖;饱和苦味酸-天狼猩红染色下观察心肌纤维化程度;荧光分光光度计法检测大鼠血清晚期糖基化终末产物(advanced glycosylation end products,AGEs)的含量;测量心肌过氧化氢酶(CAT)、谷胱甘肽过氧化物酶(GSH-Px)水平;免疫组化法和蛋白印迹法检测心肌组织AGEs及CTGF蛋白的表达。结果联合用药组可有效抑制心肌纤维化的病理进程,升高心肌组织CAT、GSH-Px水平及降低血清AGEs含量,减少心肌组织AGEs及CTGF的表达。结论灵芝多糖联合二甲双胍可能通过抑制心肌氧化应激,降低血清AGEs水平,以及下调心肌AGEs、CTGF的表达来预防心肌纤维化。     

灵芝多糖对2型糖尿病大鼠心肌组织氧化应激的影响

目的:探讨灵芝多糖(GLPs)对2型糖尿病大鼠心肌组织氧化应激的影响.方法:SD大鼠高脂饮食喂养4周后,腹腔注射链脲佐菌素(STZ)30 mg·kg-1建立2型糖尿病(T2DM)模型.成模后将大鼠随机分为正常对照组、模型组、小檗碱组(Ber组)、灵芝多糖低、中、高剂量组(剂量分别为200、400、800 mg·kg-1),给予药物治疗,第12周末检测心脏NO、SOD、MDA、CAT、GSH-Px水平及心肌细胞超微结构的变化.结果:与DM组比较,灵芝多糖中、高剂量组能有效降低血糖水平,能够有效对抗氧化应激作用.其中GLPs高剂量组效果优于中剂量组和Ber组.结论:灵芝多糖明显降低心肌组织氧化应激的水平,对2型糖尿病大鼠心肌组织具有保护作用.     

EGCG抑制心肌肥厚胶原生成和细胞增殖

目的研究表没食子儿茶素没食子酸酯(EGCG)的抗心肌肥厚作用以及对心肌肥厚胶原生成和细胞增殖的影响。方法异丙肾上腺素(Iso)致小鼠心肌肥厚,测定心脏重量指数和血清乳酸脱氢酶(LDH)、肌酸磷酸激酶(CK)活力。腹主动脉缩窄致大鼠心肌肥厚,测定心脏重量指数和心肌羟脯氨酸(Hp)含量,HE和VG染色观察心肌组织形态改变,增殖性核抗原(PCNA)免疫组化检测细胞增殖。结果EGCG50、100、200mg.kg-1剂量依赖的降低Iso致小鼠心肌肥厚的心脏重量指数及血清LDH、CK的漏出量。EGCG25、50、100mg.kg-1剂量依赖的降低腹主动脉缩窄致大鼠心肌肥厚的心脏重量指数和心肌Hp含量,明显改善心肌组织胶原增生和纤维化,EGCG50、100mg.kg-1明显降低细胞PCNA免疫组化阳性率。结论EGCG对大鼠和小鼠心肌肥厚模型有明显的抑制作用,该作用可能与改善肥厚心肌组织胶原增生和细胞增殖有关。     

灵芝多糖联合二甲双胍对2型糖尿病大鼠心肌结构及血流动力学的影响

目的探讨灵芝多糖联合二甲双胍对2型糖尿病(type 2 diabetes mellitus,T2DM)大鼠心肌结构及血流动力学的影响及其机制。方法高脂饮食喂养联合腹腔注射低剂量链脲佐菌素(STZ)30 mg·kg-1建立T2DM大鼠模型。模型动物随机分为模型组、灵芝多糖组(灵芝多糖600 mg·kg~(-1))、二甲双胍组(二甲双胍600 mg·kg~(-1))及联合用药组(灵芝多糖300 mg·kg-1+二甲双胍300 mg·kg-1),另设正常对照组。给药治疗12周末测定大鼠空腹血糖,血流动力学指标(LVSP、LVEDP、dp/dtmax、-dp/dtmax),VG染色法检测大鼠左室心肌胶原容积积分(CVF),免疫组化、蛋白印记法检测心肌组织中基质金属蛋白酶-2(MMP-2)蛋白的表达。结果联合用药组大鼠空腹血糖明显降低;联合用药能明显改善糖尿病大鼠血流动力学指标:降低LVEP,升高LVEDP、dp/dtmax、-dp/dtmax;联合用药组的CVF明显降低;心肌组织MMP-2表达得到明显抑制。结论灵芝多糖联合二甲双胍能明显改善T2DM大鼠血流动力学参数,对糖尿病心肌病变有预防作用,其机制可能与下调MMP-2的表达有关。     

灵芝多糖联合二甲双胍预防糖尿病大鼠主动脉病变及对VEGF表达的影响

目的探讨灵芝多糖联合二甲双胍对2型糖尿病大鼠胸主动脉病变的预防作用及其作用机制。方法 SD大鼠高能量饮食4周后,腹腔注射小剂量链脲佐菌素(STZ)30 mg·kg-1建立2型糖尿病(type 2 diabetes mellitus,T2DM)大鼠模型。成模后随机分为模型组、灵芝多糖组(灵芝多糖600mg·kg-1)、二甲双胍组(二甲双胍600 mg·kg-1)及联合用药组(灵芝多糖300 mg·kg-1+二甲双胍300 mg·kg-1),另设正常对照组。给药12周末测定大鼠空腹血糖、血清过氧化氢酶(CAT)、谷胱甘肽过氧化物酶(GSH-Px)、总胆固醇(TC)、甘油三酯(TG)水平;HE染色观察胸主动脉病理学变化;免疫组化、蛋白印记法检测胸主动脉VEGF的表达。结果联合用药组大鼠空腹血糖、血脂水平明显降低,血清CAT、GSH-Px水平明显升高,胸主动脉血管内皮生长因子(VEGF)表达得到抑制,主动脉病理观察显示联合用药组内膜增厚、内皮脂质沉积较模型组少。结论灵芝多糖联合二甲双胍对2型糖尿病大鼠主动脉病变有预防作用,其机制可能与抑制主动脉氧化应激,调节血脂,下调主动脉VEGF的表达有关。     

丹参酮ⅡA对压力负荷增加的大鼠TNF-α表达的影响

目的观察TNF-α在压力负荷增加大鼠血清中的表达,并探讨其对心肌纤维化的作用机制。方法 32只成年雄性SD大鼠,随机分成四组(n=8),假手术组(Sham组)、模型组(Model组)、Tan II A组(Tan II A组,20 mg.kg-1.d-1)及阳性对照药物卡托普利组(Captopril组,100 mg.kg-1.d-1)。除Sham组外,其余3组大鼠均行肾上方腹主动脉缩窄术制备压力负荷增加心肌纤维化模型,Sham组仅分离腹主动脉而不结扎。术后4周成功造模并开始给药,疗程为4周。8周后检测左室重量指数、心肌组织病理学、心肌羟脯氨酸(HYP)含量、血清TNF-α蛋白的含量。结果与Model组比较,Tan II A组能明显抑制心肌纤维化大鼠心肌组织的病理改变,降低心肌肥厚指数、心肌羟脯氨酸含量以及血清TNF-α蛋白浓度(P0.01)。结论压力负荷增加大鼠血清TNF-α蛋白表达明显升高,表明促炎细胞因子TNF-α在压力负荷增加大鼠心肌纤维化中起着重要的作用;TanII A对心肌纤维化的保护作用可能部分与下调促炎细胞因子表达有关。     

依那普利抗异丙肾上腺素诱导的心肌纤维化作用及机制

目的观察依那普利(enalapril,Ena)抗异丙肾上腺素(Isoprenaline,Iso)诱导的心肌纤维化作用并探讨其作用机制。方法异丙肾上腺素皮下注射致心肌纤维化模型,经Ena低、中、高(2.5、5.0、10.0 mg.kg-1)3个剂量组和阳性对照药卡托普利(100.0 mg.kg-1)治疗后观察其对心肌组织胶原变化、心室重量(HW/BW)和心室重量指数(LVI)、羟脯氨酸含量及免疫组化和Western blot检测TGF-β1表达的影响。结果Ena不同剂量组均能够降低心肌组织胶原含量(P<0.05或P<0.01),降低HW/BW和LVI(P<0.05或P<0.01),降低羟脯氨酸含量(P<0.05或P<0.01),减少TGF-β1在心肌组织中的表达(P<0.05或P<0.01),减轻心肌纤维化。结论Ena通过抑制TGF-β1表达抗Iso诱导的心肌纤维化。     

四味地黄乙醇提取物治疗糖尿病心肌病与氨基胍药效比较

目的:研究四味地黄2种醇提取物对STZ诱导糖尿病大鼠心肌病及血管病变的药效,与AGEs选择性阻断剂氨基胍比较。方法:腹腔一次注射60 mg.kg-1链脲佐菌素(STZ)建立糖尿病大鼠模型,4周后随机分组,5～8周分别灌胃:100 mg.kg-1氨基胍(AMG),10 g.kg-1复方地黄70%乙醇提取物,或10 g.kg-1 95%乙醇提取物。8周后,测定肠系膜动脉内皮依赖性舒张、血流动力学及心脏重量指数,血清中血糖、胆固醇(CHO),心肌组织中过氧化氢酶(CAT)、一氧化氮(NO)、一氧化氮合酶(NOS)、羟脯氨酸(HYP)。结果:STZ诱导的糖尿病大鼠血管内皮功能受损,血管内皮依赖性舒张减弱;血流动力学参数反映心功能明显下降,心肌肥大。血清中血糖与CHO含量较正常组显著升高。心肌组织中iNOS及tNOS分别较正常组大鼠升高+59.7%及+50.0%(P<0.01,P<0.01),CAT(U.mg prot-1)而活性降低-14.6%(P<0.05),HYP(μg.mg prot-1)含量显著增高+26.6%(P<0.01)。氨基胍和2种乙醇提取物,均明显改善糖尿病的血管与心脏的并发症,但无明显的降糖作用。...     

雷公藤红素对二乙基亚硝胺诱导的大鼠肝纤维化的治疗作用及机制

目的观察雷公藤红素(Celastrol,Cel)对二乙基亚硝胺(DEN)诱导大鼠肝纤维化的治疗作用及机制。方法采用DEN诱导大鼠肝纤维化模型,分为正常对照组、模型组、Cel给药组(2、4、8 mg.kg-1)和秋水仙碱组(Col,0.1 mg.kg-1)。紫外分光光度法检测各组大鼠血清中AST、ALT、肝组织中超氧化物歧化酶(SOD)、谷胱甘肽过氧化物酶(GSH-Px)活性及肝组织中丙二醛(MDA)、羟脯氨酸(HYP)的含量;ELISA检测大鼠血清中透明质酸(HA)、层粘蛋白(LN)、Ⅲ型前胶原(PCIII)、Ⅳ型前胶原(CIV)、TGF-β1的含量;Western blot检测肝脏α-平滑肌肌动蛋白(α-SMA)、Ⅰ型胶原(ColⅠ)和TGF-β1蛋白的表达;HE染色观察肝组织病理形态学变化;Masson染色观察肝组织中胶原沉积变化。结果与模型组比较,Cel能明显降低肝纤维化大鼠血清中升高的TGF-β1、ALT、AST、HA、LN、PCIII含量,降低肝组织中升高的HYP和MDA的含量,明显升高肝组织中SOD和GSH-Px酶活性,减少肝纤维化大鼠肝组织中α-SMA、Col I和TGF-β1的表达,改善其肝脏病理损伤程度,减少肝脏中胶原沉积。结论 Cel对肝纤维化大鼠有很好的治疗作用,其作用机制可能与Cel的抗氧化作用,降低TGF-β1的表达,抑制HSC活化,抑制胶原合成有关。     

灵芝多糖对糖尿病大鼠胸主动脉氧化应激的影响

目的：研究灵芝多糖对链脲佐菌素（STZ）诱导的糖尿病大鼠胸主动脉内皮损伤的保护作用及对糖尿病大鼠胸主动脉氧化应激的影响。方法：SD 大鼠经过4周高脂饮食后腹腔注射链脲佐菌素（30 mg·kg-1）造模,随机分为正常对照组、模型组、灵芝多糖（GLPs）高、低剂量组。经过12周给药治疗后,测定血清中过氧化氢酶（CAT）、谷胱甘肽过氧化物酶（GSH-PX）、总胆固醇（TC）和甘油三酯（TG）的水平;然后胸主动脉切片 HE 染色,观察胸主动脉超微结构及病理改变。结果：GLPs-H 组血糖浓度较模型组相比均明显下降（P<0.01）,血清 CAT 和 GSH-PX 水平较模型组相比均明显上升（P<0.01）;血清 TC、TG 含量较模型组相比均明显下降（P<0.01）。 HE 染色,与模型组相比,GLPs-H 组光镜下主动脉内膜增厚、内皮损伤、中膜增厚的情况有所改善。结论：灵芝多糖可减轻糖尿病大鼠体内氧化应激水平,具有减轻脂质过氧化作用,对糖尿病胸主动脉并发症的发生发展有一定的预防作用。     

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.