E-选择素在生殖道沙眼衣原体感染中的作用研究

目的 研究E-选择素在生殖道沙眼衣原体感染中的作用.方法 将64只小鼠生殖道沙眼衣原体感染模型随机分成2组,实验组中的小鼠用人工合成E-选择素干预,对照组中的小鼠用生理盐水进行干预,统计两组在1w,2w,3w,4w不同时间点上的感染小鼠阴道脱落菌量以及沙眼衣原体感染率.结果 成功建立生殖道沙眼衣原体感染的小鼠模型:与对照组相比较,人工合成E-选择素干预后1w和2w的生殖道沙眼衣原体感染率(90.2％vs 77.4％,85.3％vs 70.1％)显著增高,而阴道脱落菌量显著增高(4.758 ±0.225 vs 3.210 ±0.315,2.698±0.177 vs 1.809±0.203),两组间差异具有统计学.在干预后3w两组的沙眼衣原体感染率分别为34％和24％,阴道脱落菌量分别为1.412±0.134和1.201±0.189,两组间差异无统计学意义;两组在干预后4w的沙眼衣原体感染率均为0且无阴道脱落菌量.结论 E-选择素能促进生殖道沙眼衣原体感染的发生率以及增加沙眼衣原体的毒力,本文为进一步阐明生殖道沙眼衣原体感染的发病机制提供实验依据.     

苦参凝胶联合多西环素胶囊治疗生殖道沙眼衣原体的效果

目的 探讨苦参凝胶联合多西环素胶囊治疗生殖道沙眼衣原体临床效果。方法 选取2017年10月~2019年4月我院收治的122例生殖道沙眼衣原体感染患者,随机分为对照组和试验组,每组61例。对照组施以多西环素胶囊治疗,试验组在对照组基础上施以苦参凝胶治疗,比较两组临床治疗总有效率、病原体清除率及不良反应发生率。结果 试验组的临床治疗总有效率及病原体清除率分别为96.72%与98.36%,高于对照组的85.24%与63.93%,差异有统计学意义（P＜0.05）;试验组不良反应发生率为4.92%,低于对照组的16.40%,差异有统计学意义（P＜0.05）。结论 苦参凝胶联合多西环素胶囊治疗生殖道沙眼衣原体感染具有良好的临床效果,不仅能够提升治疗果与病原体清除率,同时能够降低不良反应发生率。     

TLR2介导沙眼衣原体感染早期免疫应答的机制研究

目的 探讨TLR2在小鼠沙眼衣原体生殖道早期感染时的免疫应答中的作用.方法 沙眼衣原体小鼠肺炎株(MoPn)经生殖道分别感染野生型小鼠(WT=11只)、TLR2基因缺陷小鼠(TLR2 KO=14只),建立生殖道沙眼衣原体感染模型.分别于感染后不同时间点取阴道棉拭子,获取分泌物,检测分泌物衣原体包涵体数量和炎症细胞因子IL-1α、IL-6和MIP-2水平.结果 TLR2 KO和WT小鼠在每个检测时间点,生殖道分泌物带菌量无差异,且带菌持续时间相同;与WT小鼠比较,在感染后第3d和第10d,TLR2 KO小鼠生殖道分泌物的炎症细胞因子IL-1α、IL-6和MIP-2水平均低于野生型WT小鼠,但差异均无统计学意义(P＞0.05);而在感染后第7d,3种细胞因子均明显低于WT小鼠,且差异有统计学意义(P＜0.05).结论 在沙眼衣原体生殖道感染中,TLR2可能介导了早期炎症细胞因子的产生.     

女性慢性生殖道炎症与抗精子免疫的相关研究

目的 :研究生殖道慢性感染状态下抗精子免疫应答的机制 ,为防治抗精子免疫性不孕提供依据。方法 :①病例选择 :诊断为慢性宫颈炎或 和慢性盆腔炎 ,有正常性生活的妇女 5 0例。对照组为有正常性生活并排除急慢性生殖道炎症的妇女 10例 ;②观察指标 :宫颈粘液病原体检测 :包括细菌、真菌、解脲支原体 (UU)与人型支原体 (MH)培养 ,沙眼衣原体(CT) ;血清ASAb总Ig测定 (ELISA法 ) ;外周血淋巴细胞亚群 (红细胞花环法 ) ;宫颈粘液白细胞介素 2 (IL 2 )。结果 :①慢性生殖道炎症组血清抗精子抗体 (ASAb)水平显著高于对照组 (P <0 0 5 ) ;解脲支原体 (UU)或 和沙眼衣原体 (CT)感染与ASAb有高度相关性 (P <0 0 1) ;②慢性生殖道炎症并抗精子抗体阳性组的妇女CD8+ 细胞减少 ,CD4 + CD8+ 比值升高 ,而宫颈粘液中IL 2水平显著升高 ,与ASAb阴性患者及正常对照组比较均有显著差异 (P <0 0 1)。结论 :女性慢性生殖道炎症可导致体内体液免疫与细胞免疫异常 ,并诱导抗精子抗体的产生。     

TLR2信号在沙眼衣原体生殖道感染中介导了早期炎症细胞因子的产生

目的探讨TLR2和TLR4在小鼠沙眼衣原体生殖道感染免疫应答中的作用。方法用沙眼衣原体小鼠肺炎株(Mo Pn,1×104IFUs)经生殖道感染野生型小鼠(WT,11只)、TLR2基因缺陷小鼠(TLR2 KO,14只)和TLR4基因缺陷小鼠(TLR4 KO,11只),复制生殖道沙眼衣原体感染模型。于感染后不同时间点取生殖道分泌物,部分用于免疫荧光法检测衣原体包涵体数量,部分用于炎症细胞因子IL-1α、IL-6和MIP-2水平检测。在感染后第70天,处死小鼠,无菌分离腹腔巨噬细胞,于体外衣原体Mo Pn感染,培养24 h后,测定上清液中IL-1α、IL-6和MIP-2含量。细胞因子含量测定均采用ELISA法。结果 TLR2 KO或TLR4 KO小鼠与WT小鼠在每一个检测时间点下生殖道带菌量无差异,且带菌持续时间相同,截止到感染后第38天,3种基因型所有小鼠均清除了下生殖道感染的衣原体。TLR2基因缺失小鼠巨噬细胞产生的炎症细胞因子IL-1α、IL-6和MIP-2水平均明显低于野生型WT小鼠(P0.01),而TLR4基因缺失小鼠巨噬细胞产生的3种炎症细胞因子水平均与野生型WT小鼠无差异(P0.05);TLR2基因缺失小鼠棉拭子标本同样具有较低水平的炎症细胞因子(P0.05)。结论在沙眼衣原体生殖道感染中,TLR2介导了早期炎症细胞因子的产生。沙眼衣原体诱导的早期免疫应答部分依赖于TLR2,而不依赖TLR4。     

阿奇霉素对泌尿生殖道沙眼衣原体临床株的单独和联合药物敏感性检测

目的 检测本地区近年来泌尿生殖道沙眼衣原体临床分离株对阿奇霉素的药物敏感性,筛查耐药株,以及体外阿奇霉素与莫西沙星、多西环素、米诺环素和利福平的相互作用情况.方法 将经McCoy细胞培养法检测出的41例沙眼衣原体临床株,传代培养至感染率达90%以上,收集标本进行阿奇霉素、莫西沙星、多西环素、米诺环素和利福平5种抗菌药物的药敏试验,采用棋盘稀释法测定阿奇霉素与莫西沙星、阿奇霉素与多西环素、阿奇霉素与米诺环素、阿奇霉素与利福平4组抗菌药物联合后的体外相互作用情况.结果 阿奇霉素最低抑菌浓度(MIC)结果为0.063～0.5μg/ml.阿奇霉素与莫西沙星、多西环素和利福平体外联合时对分别对51.22%、53.66%和58.54%的菌株为协同或相加作用,统计结果显示3组之间差异无统计学意义(P＞0.05);阿奇霉素与米诺环素联合时对90.24%的菌株为拮抗作用.结论 在体外,阿奇霉素与莫西沙星、多西环素或利福平联用,能够提高各自的抗菌活性,可能对治疗沙眼衣原体反复感染或持续感染患者的疗效优于单用一种抗菌药物;相反,阿奇霉素与米诺环素联合应用时,它们之间的拮抗作用将极大地降低各自的抗菌活性.联合药敏试验在一定程度上能够弥补单独药敏实验的一些不足.     

Toll样受体2(TLR2)和TLR4在沙眼衣原体生殖道感染介导的免疫应答

目的探讨Toll样受体2(TLR2)和TLR4在小鼠沙眼衣原体生殖道感染中的作用。方法用1×10~4包涵体形成单位的Mo Pn沙眼衣原体小鼠肺炎株经生殖道感染野生型(WT)小鼠(n=11)、TLR2基因缺陷(TLR2-/-)小鼠(n=14)和TLR4-/-小鼠(n=11),复制生殖道沙眼衣原体感染模型。在感染后第3、7、10、17、24、31、38、45天取阴道棉拭子,免疫荧光法检测衣原体包涵体数量,ELISA检测白细胞介素1α(IL-1α)、IL-6和巨噬细胞炎性蛋白2(MIP-2)水平。感染后第70天,采用免疫荧光法分析血清抗体类型和效价;用Mo Pn沙眼衣原体感染无菌分离的腹腔巨噬细胞,培养24 h,ELISA测定上清液中IL-1α、IL-6和MIP-2含量;体外用紫外线灭活的衣原体抗原刺激无菌分离的脾细胞,培养72 h,ELISA测定上清液中γ干扰素(IFN-γ)、IL-17、IL-4和IL-5水平。结果与WT小鼠相比,TLR2-/-或TLR4-/-小鼠在各时间点的生殖道带菌量无差异、且带菌持续时间相同,感染后第38天,所有小鼠均清除了下生殖道感染的衣原体。TLR2-/-小鼠巨噬细胞产生的IL-1α、IL-6和MIP-2水平均明显低于WT小鼠,而TLR4-/-小鼠巨噬细胞产生的3种炎症细胞因子水平均与WT小鼠无显著性差异;TLR2-/-小鼠棉拭子标本具有较低水平的炎症细胞因子。所有小鼠脾细胞均产生高水平的IFN-γ和IL-17、较低水平的IL-4和IL-5、血清Ig G2a/Ig G1比值均大于1,但各组间无显著性差异。结论 TLR2而不是TLR4介导了沙眼衣原体生殖道感染的早期免疫应答,但沙眼衣原体诱导的适应性免疫应答可能既不依赖于TLR4,也不依赖于TLR2。     

金标法检测514例生殖道感染妇女宫颈分泌物中沙眼衣原体抗原

目的了解育龄妇女宫颈分泌物标本中沙眼衣原体抗原阳性率。方法用金标法对2004年1月至2005年9月间拟诊为生殖道感染的年龄在23~40岁之间的育龄妇女宫颈分泌物标本检测沙眼衣原体抗原。结果514例拟诊为生殖道感染的育龄妇女生殖道标本中126例为沙眼衣原体抗原阳性,阳性率为24.5%,高于对照组(8.0%),经统计学处理,二者间有高度显著性差异(P<0.005)。结论育龄妇女生殖遒感染与沙眼衣原体有关,育龄妇女沙眼衣原体感染率较高,因孕期感染沙眼衣原体可引起母婴传播,所以应孕前、孕期及产前应常规检测沙眼衣原体,并且最好同时检测解脲支原体和淋球菌。这对优生工作有重要意义。     

三种不同药物治疗女性沙眼衣原体泌尿生殖道感染疗效观察

目的 对照观察美满霉素、阿奇霉素、加替沙星治疗沙眼衣原体所致的女性泌尿生殖道感染的疗效。方法 A组给予口服美满霉素100mg，每日2次，疗程2周；B组静脉点滴乳糖酸阿奇霉素500mg，每日1次，疗程10d；C组静脉点滴加替沙星400rag，每日1次，疗程10d。结果 A组有效率63．46％，B组有效率82．35％，C组有效率93．24％，三组有效率比较有非常显著差异性（X^2=17．96P〈0．005），不良反应发生率A（15．38％）组高于B（7.35％）、C（8．10％）两组。结论 静脉给予阿奇霉素组与加替沙星组疗效好于口服美满霉素组，阿奇霉素与加替沙星均有较好的疗效，但加替沙星的疗效更为显著，可作为治疗沙眼衣原体性泌尿生殖道感染的首选药物。     

绍兴地区女性生殖道炎症患者沙眼衣原体感染的PCR诊断调查

应用聚合酶链式反应（PCR）技术，对1995年2月至1996年5月间703例女性生殖道炎症病人进行了宫颈沙眼衣原体（CT）检测，检出阳性者124例，阳性率为17．64％，表明在生殖道炎症病人中，沙眼衣原体感染已相当普遍，有必要进行检测和治疗。     

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.     

Beta-endorphin and drug-induced reward and reinforcement

Although drugs of abuse have different acute mechanisms of action, their brain pathways of reward exhibit common functional effects upon both acute and chronic administration. Long known for its analgesic effect, the opioid beta-endorphin is now shown to induce euphoria, and to have rewarding and reinforcing properties. In this review, we will summarize the present neurobiological and behavioral evidences that support involvement of beta-endorphin in drug-induced reward and reinforcement. Currently, evidence supports a prominent role for beta-endorphin in the reward pathways of cocaine and alcohol. The existing information indicating the importance of beta-endorphin neurotransmission in mediating the reward pathways of nicotine and THC, is thus far circumstantial. The studies described herein employed diverse techniques, such as biochemical measurements of beta-endorphin in various brain sites and plasma, and behavioral measurements, conducted following elimination (via administration of anti-beta-endorphin antibodies or using mutant mice) or augmentation (by intracerebral administration) of beta-endorphin. We suggest that the reward pathways for different addictive drugs converge to a common pathway in which beta-endorphin is a modulating element. beta-Endorphin is involved also with distress. However, reviewing the data collected so far implies a discrete role, beyond that of a stress response, for beta-endorphin in mediating the substance of abuse reward pathway. This may occur via interacting with the mesolimbic dopaminergic system and also by its interesting effects on learning and memory. The functional meaning of beta-endorphin in the process of drug-seeking behavior is discussed.     

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.     

PTEN与信号转导及肿瘤

ＴＥＮ[1] (ｐｈｏｓｐｈａｔａｓｅａｎｄｔｅｎｓｉｎｈｏｍｏｌｏｇｙｄｅｌｅｔｅｄｏｎｃｈｒｏｍｏｓｏｍｅｔｅｎ)又名ＭＭＡＣ1 [2 ] (ｍｕｔａｔｅｄｉｎｍｕｔｉｐｌｙａｄａｎｃｅｄｃａｎｃｅｒ 1 )和ＴＥＰ1 [3 ] (ＴＧＦ -βｒｅｇｕｌａｔｅｄａｎｄｅｐｉｔｈｅｌｉａｌｃｅｌｌ -ｒｉｃｈｅｄｐｈｏｓｐｈａｔａｓｅ 1 ) (以下均称为ＰＴＥＮ) ,是 1 997年由 3个研究小组先后发现的一个具有双特异磷酸酶活性的抑癌基因。ＰＴＥＮ基因异常广泛存在于人类多种恶性肿瘤 ,如恶性神经胶质瘤、前列腺癌、子宫内膜癌、黑色素瘤等…     

Tobacco and alcohol and the risk of head and neck cancer

Summary We carried out two case-control studies on the relative risk of head and neck cancer in association with tobacco and alcohol consumption. The first study carried out at the ENT Department of the University hospitals of Heidelberg and Giessen (FRG) comprised 200 male patients with squamous cell cancer of the head and neck and 800 control subjects matched for sex, age, and residential area (1:4 matching design). Of the tumour patients, 4.5% had never smoked, in contrast to 29.5% of the control group. The average tobacco and alcohol consumption of the patients was approximately twice as high as in the control subjects. The highest alcohol and tobacco consumption was observed in patients suffering from oropharyngeal cancer. Tobacco and alcohol increased the risk of head and neck cancer in a dose-dependent fashion and acted as independent risk factors. In heavy smokers (> 60 pack-years) a relative risk of 23.4 (alcohol adjusted) was calculated. Combined alcohol and tobacco consumption showed a synergistic effect. The risk ratio increased more in a multiplicative than in an additive manner. Oral and laryngeal cancer were associated with the highest tobacco-associated risk values. The highest ethanol-associated risk values were associated with oropharyngeal and laryngeal cancer. The second study was carried out at the ENT Department of the University of Heidelberg on 164 males with squamous cell carcinoma of the larynx and 656 control subjects matched for sex, age and residential area (1:4 matching design). Of the cases, 4.2% had never smoked, compared with 28.5% of the control subjects. The risk of laryngeal cancer by tobacco consumption was dose dependent, reaching a maximum value of 9.1 (adjusted for alcohol) for a consumption of more than 50 tobacco-years (TY). The relative risk of laryngeal cancer associated with alcohol intake was also dose dependent, reaching a value of 9.0 (adjusted for tobacco) for a mean daily consumption of more than 75 g alcohol. An analysis of subsite specific risks showed that heavy smokers (> 50 TY) carried a nearly ten times higher risk of supraglottic cancer than of glottic cancer. The risk of supraglottic cancer from alcohol consumption was also higher than that of glottic cancer.     

类赖氨酰氧化酶2与肿瘤转移和发生

类赖氨酰氧化酶2(lysyl oxidase-like 2,LOXL2)是赖氨酰氧化酶(lysyl oxidase,LOX)基因家族的成员之一,其表达产物能促进胶原沉积.LOXL2的过表达能促进纤维化,并与肿瘤侵袭、转移及不良预后有关.目前大部分学者认为LOXL2是一种转移促进基因,也有实验支持其是一种肿瘤抑制基因.研究发现LOXL2可以通过激活Snail/Ecadherin通路或Src/FAK通路促进转移.LOXL2有望作为肿瘤生物标志物,用于预后判断,成为一个新的治疗靶点.     

Postinfectious immunodeficiency and autoimmunity: pathogenic and clinical values and implications

Autoimmunity is still a mystery of clinical immunology and medicine as a whole. The etiology and pathogenesis of autoimmune disorders remain unclear and, thus, are assessed as a balance between hereditary predisposition, triggering factors and the appearance of autoantibodies and/or self-reactive T cells. Among the immunological armamentarium, molecular mimicry, based on self-reactive T- and B-cell activation by cross-reactive epitopes of infectious agents, is of special value. Hypotheses regarding the possible involvement of molecular mimicry in the development of postinfectious autoimmunity are currently very intriguing. They provide new approaches for identifying etiological agents that are associated with postinfectious autoimmunity, paired microbial- and tissue-linked epitopes targeted for autoimmune reaction determination, postinfectious autoimmunity pathogenesis recognition and specific prevention, and therapy for autoimmune disorder development.     

Muscle strength and myoelectric activity in prepubertal and adult males and females

The purpose of this investigation was to compare children and adults of both genders with respect to torque-velocity, electromyogram (EMG)-velocity and torque-EMG relationships during maximal voluntary knee extensor muscle actions. Four groups of ten subjects each were studied comprising 11-year-old girls and boys and female and male physical education students (22–35 years). Maximal voluntary eccentric (lengthening) and concentric (shortening) actions of the knee extensors were performed at the constant velocities of 45, 90 and 180° · s^–1. Average values for torque and EMG activity, recorded by surface electrodes from the quadriceps muscle, were taken for the mid 40° of the 80° range of motion. The overall shapes of the torque- and EMG-velocity relationships were similar for all four groups, showing effects of velocity under concentric (torque decrease and EMG increase) but not under eccentric conditions. Eccentric torques were always greater than velocity-matched concentric ones, whereas the eccentric EMG values were lower than the concentric ones at corresponding velocities. Torque output per unit EMG activity was clearly higher for eccentric than for concentric conditions and the difference was of similar magnitude for all groups. Thus, the torque-EMG-velocity relationships would appear to have been largely independent of gender and to be fully developed at a prepubertal age.