Ghrelin对糖尿病大鼠海马神经元凋亡及其认知功能的影响

目的观察Ghrelin对糖尿病大鼠海马神经元凋亡及其认知功能的影响。方法 40只雄性SD大鼠随机均分为对照组、糖尿病组、糖尿病+Ghrelin组和糖尿病+Ghrelin+D-lys3-GHRP-6组,每组10只。建立STZ糖尿病模型,open-field实验排除合并抑郁症的糖尿病大鼠,Morris水迷宫测试学习与记忆能力,RT-PCR检测海马caspase-3mRNA的表达,免疫组化检测海马神经元caspase-3和BCL-xl蛋白表达,原位末端标记法检测海马神经元的凋亡。结果与对照组大鼠相比,糖尿病组和糖尿病+Ghrelin+D-lys3-GHRP-6组学习与记忆能力显著受损(P<0.05),海马部位的caspase-3 mRNA及蛋白表达明显升高(P<0.05),BCL-xl蛋白表达显著下降(P<0.05),海马神经元的凋亡增加了49%(P<0.05)。糖尿病+Ghrelin组学习和记忆成绩明显优于糖尿病组(P<0.05),其海马部位的caspase-3 mRNA及蛋白表达显著下降(P<0.05),BCL-xl蛋白表达明显升高(P<0.05),海马神经元的凋亡减少了42%。结论 Ghrelin对糖尿病大鼠...     

砷染毒对大鼠睾丸凋亡诱导因子表达及生精细胞凋亡的影响

目的:探讨砷染毒对大鼠睾丸凋亡诱导因子(AIF)表达及生精细胞凋亡的影响。方法:雄性SD大鼠被随机分为对照组和染砷组。采用自由饮用方式进行连续染毒6个月。采用免疫印迹及实时荧光定量PCR检测AIF表达水平;采用TUNEL法观察生精细胞凋亡的情况。结果:免疫印迹及实时荧光定量PCR结果显示,与对照组比较,染砷组大鼠睾丸内AIF蛋白及mRNA表达水平均显著增高。TUNEL法检测结果显示与对照组比较,染砷组生精上皮凋亡细胞平均灰度值显著增高。结论:砷染毒时AIF介导的非caspase依赖性凋亡途径可能参与了大鼠生精细胞凋亡。     

N-乙酰-L-色氨酸减轻H2O2诱导小鼠海马神经元细胞凋亡

 目的 探讨N-乙酰-L-色氨酸(L-NAT)对海马神经元（PHN）缺血低氧损伤的影响。方法 用600μmol/L H2O2诱导PHN制备海马神经元细胞凋亡模型,采用免疫荧光染色检测caspase-3的表达,Rhodamine 123染色检测线粒体膜势能（ΔΨm）的改变,台盼蓝染色检测细胞存活率,比色法检测caspase-3、乳酸脱氢酶（LDH）的活性,Western blot检测caspase-3及凋亡诱导因子（AIF）和细胞色素C（CytC）等线粒体促凋亡因子在胞质蛋白和线粒体蛋白中的表达。结果 L-NAT可减轻H2O2所引起的细胞形态的死亡、存活率的降低、LDH的释放、caspase-3的激活、线粒体膜势能的丧失及AIF和CytC等线粒体促凋亡因子的释放。 结论 L-NAT能通过抑制caspase依赖性和非依赖性的细胞凋亡途径,减轻H2O2诱导的小鼠海马神经元的细胞损伤。     

Bcl-2抑制剂对黄芪注射液降低缺氧缺糖/复氧复糖大鼠海马神经元caspase-3表达的影响

目的:观察Bcl-2抑制剂对黄芪注射液降低缺氧缺糖/复氧复糖大鼠海马神经元caspase-3表达的影响。方法:取体外原代培养8 d的海马神经元,随机分为6组:正常对照组、模型组(缺氧缺糖/复氧复糖组)、黄芪注射液组、黄芪注射液溶剂(无菌去离子水)对照组、Bcl-2抑制剂组和Bcl-2抑制剂+黄芪注射液组。除正常对照组外均进行缺氧缺糖0.5 h再复氧复糖,各组均于复氧复糖后24 h进行指标检测:采用细胞免疫化学染色法观察细胞形态和caspase-3阳性细胞率,Western blotting法检测海马神经元Bcl-2和cleaved caspase-3蛋白的表达,RTPCR法检测海马神经元caspase-3 mRNA的表达。结果:与正常对照组相比,模型组细胞caspase-3阳性率、Bcl-2、cleaved caspase-3蛋白及caspase-3 mRNA表达均明显增强(P0.05);与模型组相比,黄芪注射液组Bcl-2表达明显增加,细胞caspase-3阳性率、cleaved caspase-3蛋白及caspase-3 mRNA表达均明显降低(P0.05);而黄芪注射液溶剂对照组、Bcl-2抑制剂组及Bcl-2抑制剂+黄芪注射液组则无明显差异;黄芪注射液溶剂对照组Bcl-2表达较正常对照组无明显变化,而Bcl-2抑制剂组及Bcl-2抑制剂+黄芪注射液组显著下降(P0.05)。结论:Bcl-2抑制剂可对抗黄芪注射液降低缺氧缺糖/复氧复糖大鼠海马神经元caspase-3表达的作用,黄芪注射液通过Bcl-2发挥对缺氧缺糖/复氧复糖大鼠海马神经元凋亡的抑制作用。     

对药酸枣仁-合欢花对抑郁模型大鼠海马CA3区细胞凋亡及caspase-12表达的影响

目的:研究对药酸枣仁(SZS)-合欢花(AJF)对抑郁模型大鼠海马CA3区细胞凋亡及半胱氨酸天冬氨酸特异性蛋白酶-12(caspase-12)表达的影响,从内质网应激(ERS)角度探讨其抗抑郁作用机制。方法:将雄性SD大鼠按随机数字表法分为正常对照组(Control)、模型组(CUMS)、对药酸枣仁-合欢花组(SZS+AJF)、盐酸文拉法辛组(Venlafaxine),采用孤养加慢性不可预见性温和应激(CUMS)建立抑郁症大鼠模型,并用旷场实验评价各组大鼠行为学改变。应用DNA原位末端缺口标记(TUNEL)法检测海马CA3区神经元凋亡情况,应用免疫组化检测海马CA3区caspase-12表达。结果:与Control组比较,CUMS组大鼠旷场实验得分降低,海马CA3区细胞凋亡率及caspase-12表达显著增加。与CUMS组比较,SZS+AJF组、Venlafaxine组大鼠旷场实验得分显著增加,海马CA3区细胞凋亡率及caspase-12表达显著减少。结论:对药酸枣仁-合欢花能显著改善抑郁模型大鼠的抑郁症状,降低海马CA3区caspase-12表达,抑制海马CA3区细胞凋亡。     

孕期DEHP暴露对新生大鼠海马神经元凋亡的影响

目的:探讨孕鼠DEHP暴露对新生小鼠海马神经元凋亡的影响。方法:SD雌性孕鼠24只,随机分为对照组(Control)、DEHP低剂量组(DEHP-L)、DEHP中剂量组(DEHP-M)和DEHP高剂量组(DEHP-H),通过灌胃方法给予孕鼠不同剂量DEHP进行染毒,通过测量新生大鼠的体长、尾长和体重,观察孕期DEHP暴露对新生大鼠发育的影响;通过尼氏(Nissl)染色观察仔鼠海马神经元形态和排列方式的变化,通过TUNEL检测新生大鼠海马部位细胞凋亡,通过Western Blot检测新生大鼠海马组织active caspase-3、Bcl-2和Bax蛋白的表达。结果:与对照组相比,DEHP暴露可导致新生大鼠发育迟缓,海马神经元数量稀少、结构排列紊乱; TUNEL染色检测显示DEHP可导致仔鼠海马细胞凋亡增多(P 0. 05); Western Blot检测结果显示DEHP暴露组新生大鼠海马组织active caspase-3和Bax表达增加,Bcl-2表达下降(P 0. 05),Bax/Bcl-2比值随着DEHP浓度增加而增加。结论:孕期DEHP暴露会影响子代大鼠发育迟缓、海马细胞凋亡增加。     

睡眠剥夺促进大鼠海马神经元凋亡及相关基因表达

探讨睡眠剥夺引起的神经元凋亡与相关基因表达的变化。采用TUNEL染色观察了快眼动睡眠剥夺大鼠海马神经元形态学变化,应用原位杂交、Western blot法检测了快眼动睡眠剥夺大鼠海马bcl-2,bax mRNA,MAPKs表达的变化。结果表明：快眼动睡眠剥夺大鼠海马CAl,CA3区神经元阳性凋亡细胞数明显增多,bcl-2,bax mRNA表达明显增强,ERK活性降低,JNK蛋白表达量较对照组明显增高。提示睡眠剥夺可引起大鼠海马神经元凋亡。与凋亡相关的bcl-2,bax mRNA基因表达及MAPKs活性的变化可能涉及神经元的凋亡机制。     

MAPKs在睡眠剥夺大鼠海马神经元内表达变化的研究

目的:探讨睡眠剥夺大鼠丝裂素活化蛋白激酶(MAPKs)表达的变化及可能的意义。方法:采用TUNEL和HE法观察了睡眠剥夺大鼠海马神经元的形态学变化,采用Westernblot法、β-液闪计数法观察海马神经元ERK和JNK表达的变化。结果:快眼动睡眠剥夺组海马神经元阳性凋亡细胞数增多,ERK活性1764.00±941.56,显著低于对照组(P＜0.05),快眼动睡眠剥夺组JNK蛋白表达量为87.5%,显著高于对照组(P<0.05)。结论:睡眠剥夺可引起大鼠海马神经元MAPKs活性的变化,而这些变化可能涉及神经元的凋亡机制。     

β-榄香烯对宫颈癌细胞PI-3K/Akt信号通路活化和凋亡相关蛋白表达的影响

目的研究β-榄香烯对人宫颈Hela细胞凋亡相关蛋白caspase-3、caspase-9表达和PI-3K/Akt信号通路的影响。方法实验分为对照组和β-榄香烯处理组,应用AnnexinV-FITC凋亡检测试剂盒及流式细胞仪检测细胞凋亡率,并采用免疫荧光、Western Blot方法检测Akt、p-Akt、天冬氨酸特异性半胱氨酸蛋白酶3(caspase-3),天冬氨酸特异性半胱氨酸蛋白酶9(caspase-9)、凋亡诱导因子(AIF)、细胞色素C(Cyto c)蛋白表达。结果β-榄香烯以剂量和时间依赖方式抑制宫颈癌细胞增殖和细胞活性。与对照组相比,β-榄香烯处理组凋亡细胞数量和相关凋亡蛋白(caspase-3、caspase-9、AIF、Cyto c)表达水平升高,β-榄香烯作用组p-Akt的表达水平明显升高。结论β-榄香烯抑制宫颈癌细胞增殖和诱导细胞凋亡可能与上调凋亡相关蛋白表达和PI-3K/Akt信号通路相关。     

黄芪注射液对脑缺血再灌注大鼠海马神经元凋亡及JNK3表达的影响

目的:观察黄芪注射液对脑缺血再灌注大鼠海马神经元凋亡及c-Jun N末端激酶3(JNK3)表达的影响。方法:四血管阻断法制备脑缺血再灌注大鼠模型。设假手术组、脑缺血再灌注模型组(模型组)、脑缺血再灌注模型+黄芪注射液组(黄芪注射液组)和脑缺血再灌注模型+黄芪注射液溶剂对照组(溶剂对照组)。除假手术组外其余3组根据再灌注时间不同又分为0 h、0.5 h、2 h、6 h、24 h、72 h和120 h 7个亚组。采用TUNEL法检测海马神经元凋亡,Western blotting法检测海马组织JNK3蛋白变化,real-time PCR法检测海马组织JNK3 mRNA 的表达变化。结果:与假手术组比,模型组大鼠各个时点凋亡细胞数均增多(P<0.05);与模型组比,黄芪注射液组各个时点的细胞凋亡数明显减少(P<0.05),而黄芪注射液溶剂对照组各个时点的细胞凋亡数无明显变化(P>0.05)。除120 h外,模型组各时点海马组织JNK3蛋白及mRNA表达均较假手术组增加(P<0.05);与模型组相比,黄芪注射液可减弱除120 h之外的各时点JNK3 蛋白及mRNA的表达(P<0.05),而黄芪注射液溶剂对照组则无明显变化(P>0.05)。结论:黄芪注射液可抑制脑缺血再灌注大鼠海马神经元凋亡,其抗凋亡机制可能与下调JNK3 mRNA及蛋白表达有关。     

Pain and Effusion and Quadriceps Activation and Strength

Context:

Quadriceps dysfunction is a common consequence of knee joint injury and disease, yet its causes remain elusive.

Objective:

To determine the effects of pain on quadriceps strength and activation and to learn if simultaneous pain and knee joint effusion affect the magnitude of quadriceps dysfunction.

Design:

Crossover study.

Setting:

University research laboratory.

Patients or Other Participants:

Fourteen (8 men, 6 women; age = 23.6 ± 4.8 years, height = 170.3 ± 9.16 cm, mass = 72.9 ± 11.84 kg) healthy volunteers.

Intervention(s):

All participants were tested under 4 randomized conditions: normal knee, effused knee, painful knee, and effused and painful knee.

Main Outcome Measure(s):

Quadriceps strength (Nm/kg) and activation (central activation ratio) were assessed after each condition was induced.

Results:

Quadriceps strength and activation were highest under the normal knee condition and differed from the 3 experimental knee conditions (P < .05). No differences were noted among the 3 experimental knee conditions for either variable (P > .05).

Conclusions:

Both pain and effusion led to quadriceps dysfunction, but the interaction of the 2 stimuli did not increase the magnitude of the strength or activation deficits. Therefore, pain and effusion can be considered equally potent in eliciting quadriceps inhibition. Given that pain and effusion accompany numerous knee conditions, the prevalence of quadriceps dysfunction is likely high.Key Words: arthrogenic muscle inhibition, central activation failure, voluntary activation, muscles

Key Points

• Knee pain and effusion resulted in arthrogenic muscle inhibition and weakness of the quadriceps.
• The simultaneous presence of pain and effusion did not increase the magnitude of quadriceps dysfunction.
• To reduce arthrogenic muscle inhibition and improve muscle strength, clinicians should employ interventions that target removing both pain and effusion.

Quadriceps weakness is a common consequence of traumatic knee joint injury^1,2 and chronic degenerative knee joint conditions.^3,4 Arthrogenic muscle inhibition (AMI), a neurologic decline in muscle activation, results in quadriceps weakness and hinders rehabilitation by preventing gains in strength.⁵ The inability to reverse AMI and restore muscle function can lead to decreased physical abilities,⁶ biomechanical deficits,⁷ and possibly reinjury.⁵ Furthermore, researchers^8,9 have suggested that quadriceps weakness resulting from AMI may place patients at risk for developing osteoarthritis in the knee. In light of the substantial influence of quadriceps AMI on these clinically relevant outcomes, we need to improve our understanding of the factors that contribute to this neurologic decline in muscle activity so efforts to target and reverse it can be implemented and gains in strength can be achieved more easily.Joint injury and disease are accompanied by numerous sequelae (ie, pain, swelling, tissue damage, inflammation), so ascertaining which one ultimately leads to neurologic muscle dysfunction is difficult. Whereas a joint effusion can result in AMI,^10–12 the effects of pain are less understood despite many clinicians attributing AMI to pain. Using techniques that introduce knee pain without accompanying injury may provide insights into the role of pain in eliciting AMI.The degree of knee joint damage may play a role in the quantity of AMI that manifests. Hurley et al^13,14 demonstrated that quadriceps AMI, measured using an interpolated-twitch technique, was greater in patients with extensive traumatic knee injury (eg, fractured tibial plateau, ruptured medial collateral ligament, and medial meniscectomy) than patients with isolated joint trauma (ie, isolated anterior cruciate ligament [ACL] rupture). Similarly, patients with more knee joint symptoms (ie, greater number of symptoms and increased severity of symptoms) may present with greater magnitudes of quadriceps inhibition. Recently, investigators¹⁵ have suggested that patients with more pain display less quadriceps strength, supporting this tenet. Given that effusion and pain often present simultaneously with joint injuries and diseases, such as ACL injury and osteoarthritis, examining both the isolated and cumulative effects of these sequelae appears warranted to determine if they influence the magnitude of muscle inhibition.Experimental joint-effusion and pain models are safe and effective experimental methods that allow for the isolated examination of their effects on muscle function. The effusion model, whereby sterile saline is injected directly into the knee joint capsule,⁷ produces a clinically relevant magnitude of the joint effusion that may be present with traumatic injury. Effusion is thought to activate group II afferents responding to stretch or pressure,^16–18 which in turn may facilitate group Ib interneurons and result in quadriceps AMI.⁵ The pain model involves injecting hypertonic saline into the infrapatellar fat pad to produce anteromedial knee pain similar to that described in patients with patellofemoral pain syndrome.¹⁹ Pain is considered to initiate AMI through activation of group III and IV afferents that act as nocioceptors to signal damage or potential damage to joint structures.^16–18 The firing of these afferents then may lead to facilitation of group Ib interneurons, the flexion reflex, or the gamma loop, ultimately resulting in quadriceps inhibition.²⁰ Thus, these models allow us to create symptoms that are associated with knee injury and have the added benefit of providing a way to examine their effects in isolation.Therefore, the purpose of our study was to determine the effects of pain on quadriceps strength and activation and to learn if simultaneous pain and knee joint effusion would affect the magnitude of quadriceps dysfunction. We hypothesized that pain alone would result in quadriceps inhibition and that the magnitude of inhibition would be greater when effusion and pain were present simultaneously.     

即早基因c-fos与脑血管病及学习记忆

即早基因c-fos是广泛存在于原核细胞和真核细胞的高度保守基因.在正常情况下,c-fos基因参与细胞生长、分化、信息传递、学习和记忆等生理过程,而在病理情况下c-fos基因表达及调控变化与多种疾病的发生和发展有关.C-fos在中枢神经系统的某些部位可有基础水平的表达,但表达很低,当受到如脑缺血、脑出血、痫性发作、应激等刺激后,其在数十分钟内做出反应,在对外界刺激-转录耦联的信忠传递过程中起着核内第三信使的重要作用.     

Opportunities and challenges in the prevention and control of cancer and other chronic diseases: children's diet and nutrition and weight and physical activity

OBJECTIVE: The purpose of this article is to review the role of behavioral research in disease prevention and control, with a particular emphasis on lifestyle- and behavior-related cancer and chronic disease risk factors--specifically, relationships among diet and nutrition and weight and physical activity with adult cancer, and tracking developmental origins of these health-promoting and health-compromising behaviors from childhood into adulthood. METHOD: After reviewing the background of the field of cancer prevention and control and establishing plausibility for the role of child health behavior in adult cancer risk, studies selected from the pediatric published literature are reviewed. Articles were retrieved, selected, and summarized to illustrate that results from separate but related fields of study are combinable to yield insights into the prevention and control of cancer and other chronic diseases in adulthood through the conduct of nonintervention and intervention research with children in clinical, public health, and other contexts. RESULTS: As illustrated by the evidence presented in this review, there are numerous reasons (biological, psychological, and social), opportunities (school and community, health care, and family settings), and approaches (nonintervention and intervention) to understand and impact behavior change in children's diet and nutrition and weight and physical activity. CONCLUSIONS: Further development and evaluation of behavioral science intervention protocols conducted with children are necessary to understand the efficacy of these approaches and their public health impact on proximal and distal cancer, cancer-related, and chronic disease outcomes before diffusion. It is clear that more attention should be paid to early life and early developmental phases in cancer prevention.