人参皂苷Rb1调控MAPK通路改善小鼠脑缺血再灌注诱导血脑屏障损伤的作用研究

目的 探讨人参皂苷Rb₁对小鼠脑缺血再灌注诱导的血脑屏障（BBB）损伤的作用及机制。方法 将C57BL/6小鼠随机分为假手术组、模型组和人参皂苷Rb₁低、中、高剂量（5、10、20 mg·kg^-1）组,采用线栓法栓塞颈内动脉1 h后复灌建立脑缺血再灌注损伤模型,假手术组不栓塞,其余操作同模型小鼠。缺血1 h后ip相应药物,于再灌注24 h后处死取材。采用伊文思蓝染色法检测各组小鼠BBB损伤程度;采用实时荧光定量PCR （qRT-PCR）法检测各组小鼠脑组织中炎症因子白细胞介素-1β（IL-1β）、白细胞介素-6（IL-6）、肿瘤坏死因子-α（TNF-α）以及紧密连接蛋白1（ZO-1）、闭合蛋白（Occludin）的mRNA表达水平;同时采用Western blotting检测各组小鼠脑组织中ZO-1、Occludin蛋白,金属基质蛋白酶-2（MMP-2）、基质金属蛋白酶-9（MMP-9）以及MAPK通路相关蛋白磷酸化的表达水平。结果 与模型组相比,人参皂苷Rb₁可显著减少脑缺血再灌注小鼠脑组织中伊文思蓝的渗漏量（P<0.05）,显著降低脑组织中IL-1β、IL-6和TNF-α的mRNA转录水平（P<0.05、0.01）;显著上调ZO-1和Occludin的mRNA转录和蛋白表达水平（P<0.05、0.01）;显著降低MMP-2、MMP-9的蛋白表达水平（P<0.05、0.01）;显著抑制MAPK通路p38、JNK及ERK磷酸化蛋白的表达（P<0.05、0.01）。结论 人参皂苷Rb₁对小鼠脑缺血再灌注诱导的BBB损伤具有一定的改善作用,其作用机制可能与抑制MAPK信号通路激活,减少MMP-2、MMP-9蛋白的表达,进而减轻对ZO-1、Occludin等紧密连接蛋白的降解有关。     

益生菌对非酒精性脂肪肝相关细胞的作用

目的 探讨益生菌对非酒精性脂肪肝相关的肠上皮细胞、肝Kupper细胞和肝实质细胞的作用及其作用机制。方法 将人肠上皮细胞Caco-2、大鼠肝Kupper细胞和小鼠肝实质细胞AML12分别分成空白对照组、脂多糖（LPS）组、嗜酸乳杆菌组、LPS+嗜酸乳杆菌组、粪肠球菌组、LPS+粪肠球菌组、双歧杆菌组、LPS+双歧杆菌组,孵育培养6 h。分别检测人肠上皮细胞Caco-2紧密连接相关因子表达情况及细胞通透性、大鼠肝Kupper细胞功能表型相关因子和IκB及p-IκB变化水平、小鼠肝实质细胞AML12脂代谢基因水平和脂类吸收情况。结果 益生菌可显著抑制由LPS刺激引起的人肠上皮细胞Caco-2紧密连接相关因子Occludin、Claudin-1、JAM、ZO-1表达的下降和细胞通透性的增加;明显抑制LPS刺激引起的大鼠肝Kupper细胞表达TNF-α、IFN-γ和IL-6的增加,同时抑制IL-4、IL-10、IL-13的降低和p-IκB蛋白表达的增加;显著抑制由LPS刺激引起的小鼠肝实质细胞AML12脂代谢基因ACACA、SREBF1、FAS、FABP3、FABP4、DGAT1的上调和脂类吸收的增加。结论 益生菌可以通过促进肠上皮细胞紧密连接相关因子的表达,降低细胞通透性,抑制肝Kupper细胞NF-κB通路活性,降低促炎性细胞因子、增加抑炎性细胞因子表达水平,抑制肝实质细胞脂代谢基因表达和脂类吸收等多种途径,保护非酒精性脂肪肝。     

栀子苷介导GLP-1R/Akt信号通路改善大鼠脑缺血再灌注损伤和神经元凋亡的研究

目的 观察栀子苷对脑缺血再灌注损伤（CIRI）模型大鼠的神经保护作用及对胰高血糖素样肽-1受体（GLP-1R）/蛋白激酶B（Akt）信号通路的影响。方法 50只SD大鼠随机分为假手术组,模型组,栀子苷低、高剂量组及尼莫地平片组,每组10只。采用线栓法制备CIRI大鼠模型,缺血2 h再灌注24 h后,栀子苷低、高剂量组大鼠分别ig给予10、40 mg·kg^-1的栀子苷,尼莫地平片组大鼠ig给予8.1 mg·kg^-1尼莫地平,假手术组和模型组大鼠ig等体积生理盐水,每天1次,连续7 d。造模后及给药结束后,分别对各组大鼠进行神经功能缺损评分;给药结束后,采用酶联免疫吸附法（ELISA）检测血清中肿瘤坏死因子-α（TNF-α）、白细胞介素-1β（IL-1β）及白细胞介素-6（IL-6）水平,苏木素-伊红（HE）染色检测脑组织病理学变化,尼氏染色检测神经元与尼氏小体变化,免疫组化染色检测脑组织B淋巴细胞瘤-2（Bcl-2）和Bcl-2关联X蛋白（Bax）表达,蛋白质印迹法（Western blotting）检测脑组织细胞色素C（Cyt-C）、半胱氨酸蛋白酶-3（Caspase-3）、半胱氨酸蛋白酶-9（Caspase-9）、胰高血糖素样肽-1受体（GLP-1R）及磷酸化蛋白激酶B（p-Akt）蛋白表达水平。结果 与假手术组比较,模型组大鼠神经功能缺损评分显著升高（P＜0.05）,血清中TNF-α、IL-1β、IL-6水平显著升高（P＜0.05）;皮质细胞间质疏松、增宽,有大量神经元细胞质萎缩和细胞核损伤;脑神经元皱缩,尼氏小体变小,数目明显减少。大鼠脑组织Bcl-2表达显著降低（P＜0.05）,Bax表达显著升高（P＜0.05）;脑组织中Cyt-C、Caspase-3、Caspase-9蛋白表达水平显著升高（P＜0.05）,GLP-1R和p-Akt蛋白表达水平显著降低（P＜0.05）。与模型组比较,栀子苷高剂量组和尼莫地平片组大鼠神经功能缺损评分均显著降低（P＜0.05）,血清中TNF-α、IL-1β、IL-6水平显著降低（P＜0.05）,皮质细胞较为整齐,神经元细胞和尼氏小体损伤减小,Bcl-2表达显著升高（P＜0.05）,Bax表达显著降低（P＜0.05）,同时,Cyt-C、Caspase-3及Caspase-9蛋白表达水平显著下降（P＜0.05）,GLP-1R和p-Akt蛋白表达水平显著升高（P＜0.05）。结论 栀子苷能够改善大鼠CIRI,减少神经元凋亡,其作用机制可能与激活GLP-1R/Akt信号通路有关。     

咖啡酸苯乙酯通过下调LRRK2抑制JNK信号通路减轻大鼠创伤性颅脑损伤

目的 探究咖啡酸苯乙酯（CAPE）对创伤性颅脑损伤（TBI）大鼠的作用及机制。方法 54只SD大鼠随机分为假手术组,模型组,CAPE低、高剂量（5、10 mg·kg^-1）组,CAPE （10 mg·kg^-1）+腺相关病毒阴性对照（oe-NC,1×10⁹ pfu,200 μL）组,CAPE （10 mg·kg^-1）+过表达LRRK2腺相关病毒（oe-LRRK2,1×10⁹ pfu,200 μL）组,每组9只。采用改良的Feeney法制备TBI模型,造模后30 min,CAPE和oe-NC、oe-LRRK2均ip给药,假手术组和模型组大鼠ip等量溶剂。所有大鼠每天给药1次,连续7 d。改良神经功能缺损评分（mNSS）评估大鼠神经功能缺损程度;转棒实验评价大鼠综合运动能力;检测各组大鼠脑组织含水量;ELISA法检测血清神经元特异性烯醇化酶（NSE）、白细胞介素（IL）-6、肿瘤坏死因子（TNF）-α和IL-1β水平;实时荧光定量PCR（qRT-PCR）法检测LRRK2 mRNA表达;Western blotting检测LRRK2、p-JNK和JNK蛋白表达;TUNEL染色检测大脑皮层细胞凋亡;FJB染色检测神经元细胞死亡。结果 与假手术组相比,模型组大鼠mNSS、脑组织含水量、大脑皮层细胞凋亡率、FJB⁺细胞数以及血清中NSE、IL-6、TNF-α和IL-1β含量显著升高（P<0.05）,LRRK2 mRNA和LRRK2、p-JNK/JNK蛋白水平显著升高（P<0.05）,转棒时间显著降低（P<0.05）;与模型组相比,CAPE低、高剂量组大鼠mNSS、脑组织含水量、大脑皮层细胞凋亡率、FJB+细胞数以及血清中NSE、IL-6、TNF-α和IL-1β含量显著降低（P<0.05）,LRRK2 mRNA和LRRK2、p-JNK/JNK蛋白表达显著降低（P<0.05）,转棒时间显著升高（P<0.05）;与CAPE+oe-NC组相比,CAPE+oe-LRRK2组大鼠mNSS、脑组织含水量、细胞凋亡率、FJB+细胞数以及血清中NSE、IL-6、TNF-α和IL-1β含量显著升高（P<0.05）,LRRK2 mRNA和LRRK2、p-JNK/JNK蛋白表达显著升高（P<0.05）,转棒时间显著降低（P<0.05）。结论 CAPE可能通过下调LRRK2表达抑制JNK通路活化,在TBI中发挥保护作用。     

樟芝多糖辅助bFGF对于大鼠机械性脊髓损伤后神经功能修复的作用研究

目的 研究樟芝多糖联合碱性成纤维细胞因子（basic fibroblast growth factor,bFGF）对于机械性脊髓损伤的大鼠神经功能修复的作用。方法 采用改良的Allens法构建大鼠脊髓机械性损伤模型,将大鼠分为对照组、模型组、bFGF组、樟芝多糖组、bFGF+樟芝多糖组,药物干预时间为30 d。在药物干预后第1,7,14,21,30天对大鼠进行脊髓损伤（Basso-Beattie-Bresnahan,BBB）评分、诱发电位（somatosensory evoked potential,SEP）试验、运动诱发电位（motor evokedpotential,MEP）试验,30 d后处死大鼠,提取脊髓组织后进行HE染色和Nissl染色,Elisa检测组织中炎症因子肿瘤坏死因子（TNF-α）、白介素1β（IL-1β）、趋化因子10（CXCL-10）、集落刺激因子（GM-CSF）和白介素10（IL-10）的表达。结果 bFGF、樟芝多糖单一使用对小鼠神经功能BBB评分和SEP、MEP试验结果均优于模型组（P<0.05）,而bFGF+樟芝多糖组的BBB评分和SEP、MEP试验优于单一用药组（P<0.05）。bFGF组、樟芝多糖组、bFGF+樟芝多糖组的脊髓组织中炎症因子TNF-α、IL-1β、CXCL-10的表达显著低于模型组（P<0.05）,而GM-CSF和IL-10的表达高于模型组（P<0.05）,且bFGF+樟芝多糖组显著优于bFGF组和樟芝多糖组（P<0.05）。结论 樟芝多糖辅助bFGF对于机械性脊髓损伤大鼠有着良好的神经功能修复作用,且优于使用单一的bFGF,其作用可能与抗炎症因子的表达,促进神经细胞的存活有关。     

利多卡因调控Apelin/APJ系统对脓毒症相关性脑病大鼠的脑保护作用

目的 探究利多卡因对脓毒症相关性脑病模型大鼠的脑保护作用及机制。方法 将40只大鼠按随机数字表法分为对照组、模型组、利多卡因组、利多卡因＋血管紧张素受体AT1相关的受体蛋白拮抗剂Apelin13（F13A）组,每组10只。除对照组外,其余3组大鼠均构建脓毒症相关性脑病模型,利多卡因组和利多卡因＋F13A组造模后即刻给予利多卡因10 mg/kg负荷剂量,随后尾iv利多卡因10 mg/kg并持续3 h,利多卡因＋F13A组同时ip APJ拮抗剂F13A 100 μg/kg。24 h后,Morris水迷宫实验检测各组大鼠认知功能,酶联免疫吸附（ELISA）法检测各组大鼠血清白细胞介素（IL）-6、IL-10、肿瘤坏死因子-α（TNF-α）水平,苏木精-伊红（HE）染色观察各组大鼠脑组织病理变化,TdT介导的dUTP缺口末端标记法（TUNEL）和神经元特异核蛋白（NeuN）双免疫荧光染色检测各组大鼠脑组织皮质内神经元凋亡,免疫荧光双染法观察各组大鼠脑组织皮质内Apelin与APJ表达,实时荧光定量逆转录聚合酶链反应（RT-qRCR）检测各组大鼠脑组织Apelin和APJ的mRNA表达,蛋白质免疫印迹（Western blotting）法检测各组大鼠脑组织Apelin和APJ的蛋白表达。结果 与模型组比较,利多卡因组大鼠逃避潜伏期缩短,通过目标象限次数增加（P＜0.05）,血清IL-6、TNF-α水平降低而IL-10水平显著升高（P＜0.05）,海马区神经元损伤明显减轻,形态和分布均趋于正常,脑组织皮质内凋亡神经元数目减少（P＜0.05）;Apelin与APJ荧光染色表达均明显增强,脑组织内Apelin、APJ的mRNA与蛋白相对表达量均显著上调（P＜0.05）;与利多卡因组比较,利多卡因＋F13A组大鼠逃避潜伏期延长,通过目标象限次数减少（P＜0.05）,血清IL-6、TNF-α水平升高,血清IL-10水平显著降低（P＜0.05）,海马区神经元损伤加重,有大量细胞肿胀与细胞核固缩,脑组织皮质内凋亡神经元数目增加（P＜0.05）。同时,Apelin与APJ荧光染色表达均明显减弱,脑组织内Apelin、APJ的mRNA与蛋白相对表达量均显著下调（P＜0.05）。结论 利多卡因能够改善脓毒症相关性脑病模型大鼠脑损伤,抑制炎症反应,并减少神经元凋亡,其机制可能与激活Apelin/APJ系统有关。     

注射用血栓通（冻干）对糖尿病大鼠海马损伤保护作用的研究

目的 研究注射用血栓通（冻干）（XST）减轻糖尿病大鼠海马神经损伤的作用。方法 ip链脲佐菌素（STZ）制备糖尿病大鼠模型,随机分为模型组和XST（50 mg/kg）组,每组10只,另随机取10只SD大鼠为对照组。ip给药,每天给药1次,于屏障环境中连续给药60 d,对照组和模型组大鼠ip等量生理盐水。常规HE染色观察大鼠海马CA1区细胞的形态;采用实时荧光定量PCR（qRT-PCR）技术对海马Bax、Bcl-2、Bcl-xl、脑源性神经营养因子（BDNF）、胶质细胞源性神经营养因子（GDNF）、神经突触素（Syn）mRNA水平进行检测;采用Western blotting法对3种紧密连接蛋白——海马闭锁小带蛋白1（ZO-1）、咬合蛋白（Occludin）、封闭蛋白5（Claudin-5）和BDNF蛋白表达水平进行检测。结果 与模型组比较,XST减轻糖尿病引起的海马神经细胞形态改变,显著增加细胞数目（P<0.05） ;显著升高抑凋亡基因Bcl-2、Bcl-xlmRNA的表达,降低促凋亡基因Bax mRNA的表达（P<0.05） ;XST组3种紧密连接蛋白的表达量均不同程度的升高,其中Occludin、Claudin-5差异有统计学意义（P<0.05、0.01）;XST组GDNF、BDNF mRNA表达、BDNF蛋白表达均显著升高（P<0.05）。结论 XST可以减轻糖尿病大鼠海马神经损伤,其机制可能与提高紧密连接蛋白及神经营养因子表达有关。     

硫辛酸对脑缺血再灌注损伤大鼠RAGE/LRP1通路及神经血管单元重塑的影响

目的 探究硫辛酸对脑缺血再灌注损伤大鼠神经血管单元重塑的作用及对晚期糖基化终产物受体（RAGE）/低密度脂蛋白受体相关蛋白1（LRP1）的影响。方法 108只雄性Wistar大鼠,除18只作为假手术组外,其余大鼠采用线栓法制备大脑中动脉短暂缺血再灌注（tMCAO）模型。模型成功大鼠根据神经评分分为模型组、FPS-ZM1 （RAGE抑制剂,1 mg·kg^-1）组和硫辛酸高、中、低剂量组（40、20、10 mg·kg^-1）,再灌注2 h后ip给药,假手术组和模型组注射等量生理盐水,每天1次,连续给药14 d。术后1、7、14 d对大鼠进行神经功能缺损程度评分（mNSS）和激光散斑成像仪监测脑血流量（CBF）。术后14 d,2,3,5-氯化三苯基四氮唑（TTC）染色法检测大鼠脑梗死面积;伊文思蓝（EB）检测血脑屏障通透性;免疫荧光染色检测脑微血管密度并采用免疫组化法检测胶质纤维酸性蛋白（GFAP）、神经元核抗原（NeuN）表达;实时荧光定量PCR（qRT-PCR）检测血管内皮生长因子（VEGF）、促血管生成素1（Ang-1）、促血管生成素2（Ang-2）的mRNA表达; Western blotting检测基质金属蛋白酶9（MMP9）、紧密连接相关蛋白5（claudin5）、RAGE、LRP1蛋白表达。结果 与假手术组比较,模型组大鼠mNSS评分、脑梗死百分比、EB含量、GFAP阳性细胞数、脑组织Ang-2 mRNA水平、MMP9和RAGE蛋白表达显著升高（P<0.05）,CBF、NeuN阳性细胞数、VEGF和Ang-1 mRNA水平、claudin5和LRP1蛋白表达显著降低（P<0.05）;与模型组比较,硫辛酸高、中剂量组大鼠mNSS评分、脑梗死百分比、EB含量、GFAP阳性细胞数、脑组织Ang-2 mRNA、MMP9和RAGE蛋白表达显著降低（P<0.05）,CBF、脑微血管密度、NeuN阳性细胞数、VEGF和Ang-1 mRNA、claudin5和LRP1蛋白表达显著升高（P<0.05）。结论 硫辛酸可降低BBB的通透性,促进血管新生,对神经血管单元起着修复和保护作用;其作用机制可能与下调RAGE的表达,上调LRP1的表达有关。     

杜仲醇提取物通过NF-kB信号通路改善大鼠牙周组织病的作用研究

目的 探讨杜仲醇提取物通过NF-kB信号通路作用于牙周病破骨细胞活化因子（IL-1β）改善大鼠牙周组织病的疗效。方法 选取SPF级Wistar大鼠60只,♂,随机数字表法分成4组,正常组,模型组,杜仲醇提取物低、高剂量组,各15只。除正常组外,其他大鼠制备牙周病模型,造模1周后杜仲醇提取物低、高剂量组分别在大鼠上颌右侧第一、第二磨牙间腭、颊侧的龈沟底内注入0.2 mL 0.1,1.0 mg·mL^-1的杜仲醇提取物,正常组与模型组大鼠注入等剂量生理盐水,连续注入5 d。Western-blot、荧光定量PCR检测大鼠牙周膜成纤维细胞内破骨细胞活化因子（IL-1β）蛋白、mRNA表达状况。结果 与正常组相比,模型组大鼠成纤维细胞内IL-1β、NF-kB mRNA相对表达量显著上升（P<0.05）;与模型组相比,杜仲醇提取物低、高剂量组大鼠成纤维细胞内IL-1β、NF-kB mRNA相对表达量显著下降（P<0.05）。与正常组相比,模型组大鼠血清IL-6、IL-1β及TNF-α含量显著上升（P<0.05）;与模型组相比,杜仲醇提取物低、高剂量组大鼠血清IL-6、IL-1β及TNF-α含量显著下降（P<0.05）。与正常组相比,模型组大鼠上颌组织内NF-kB、IL-1β蛋白表达显著上升（P<0.05）;与模型组相比,杜仲醇提取物低、高剂量组大鼠上颌组织内NF-kB、IL-1β蛋白表达下降（P<0.05）。结论 杜仲醇提取通过NF-kB信号路径对牙周病破骨细胞活化因子（IL-1β）产生作用,降低牙周组织内炎症因子含量,对牙周病起到治疗作用。     

促血管生成素-1蛋白减少大鼠尿激酶溶栓后脑出血转化及机制研究

摘 要 目的：探索促血管生成素-1（Ang-1）蛋白能否减少尿激酶溶栓的大鼠脑梗死模型出血转化率、出血量及其可能的机制。方法: 清洁级SD大鼠按照随机分组法分为4组：假手术组,生理盐水对照组、尿激酶溶栓组、尿激酶+Ang-1组,每组24只。比较各组出血转化率、出血量、脑水肿、血脑屏障破坏情况和紧密连接蛋白occludin,ZO-1的表达。采用脑组织干湿重法评估脑水肿程度,伊文思蓝通透率评估血脑屏障破坏情况,RT-PCR和Western blot检测紧密连接蛋白occludin,ZO-1 mRNA的表达水平。结果: 尿激酶溶栓组的出血量、脑水肿和血脑屏障破坏程度相较于其余各组明显增高（P<0.05）;occludin,ZO-1的表达低于其余各组（P<0.05）;尿激酶+Ang-1组的出血转化率、出血量、脑水肿和血脑屏障破坏程度低于尿激酶溶栓组（P<0.05）。Occludin,ZO-1表达比尿激酶溶栓组增高（P<0.05）。结论:Ang-1蛋白可减少尿激酶溶栓所致的脑出血、血脑屏障损失及脑水肿水平,其机制可能与增加紧密连接蛋白occludin,ZO-1的表达从而保护血脑屏障有关。     

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.