应用PCR检测慢性牙周炎患者龈下菌斑中牙龈卟啉单胞菌及感染菌株基因型的分析

目的建立慢性牙周炎(CP)龈下标本中牙龈卟啉单胞菌(Porphyromonas gingivalis, Pg)的PCR检测方法,了解不同患牙龈下菌斑中Pg基因型的差异. 方法采用培养法分离不同患牙龈下菌斑中Pg,同时采用 PCR进行Pg 16S rDNA基因、prtC基因和fimA基因的检测.部分扩增产物T-A克隆后测定核苷酸序列. 结果 61例患者122个龈下菌斑标本中,Pg 16S rDNA、prtC和fimA分别扩增的阳性率依次为 90.6%、81.9%和78.0%,联合扩增的阳性率高达98.4%,培养法阳性率仅为 31.1%.30.0%(18/60)患者不同牙位龈下菌斑中的Pg基因型不一致.Pg 16S rDNA、prtC和fimA扩增片段与文献报道的核苷酸序列比较,同源性为98.62%～100%. 结论所建Pg PCR检测方法具有较高的敏感性和特异性,可用于慢性牙周炎龈下标本中Pg的快速临床诊断.部分CP患者可被不同基因型的Pg菌株同时感染.     

慢性牙周炎患者龈下菌斑中伴放线放线杆菌基因型的分析

目的：建立龈下菌斑标本中伴放线放线杆菌（Actinobacillus actinomycetemcomitans，Aa）PCR检测方法，了解慢性牙周炎患者不同牙位的龈下菌斑中Aα 的感染率及其优势基因型。方法：61例慢性牙周炎患者每例采取2个不同牙位共122份龈下菌斑标本，采用培养法分离Aα菌株，以PCR或多重PCR检测16SrDNA基因、lktA基因和fap基因，部分扩增产物克隆后测序。结果：在11例患者的11份龈下菌斑标本中分离到Aα菌株。122份龈下菌斑中Aα16SrDNA、lktA、和fap检测阳性率分别为84.4%、75.4%、和50.0%。38.8%的患者（19/49）不同牙位龈下菌斑中检出的Aα基因型不一致。Aα有4种基因型，其优势基因型是16SrDNA^ /lktA^ /fap^ ，其次为16SrDNA^ /lktA^ /fap^-。部分标本上述3种基因的扩增片段与文献报道核苷酸序列的同源性为93.75%-100%。结论：建立的PCR或多重PCR有较高的敏感性和特异性，适用于龈下菌斑标本中Aα的快速检测。慢性牙周炎患者Aα感染率较高，并存在优势基因型，部分患者可被不同基因型的菌株同时感染。     

应用PCR检测慢性牙周炎患者龈下菌斑中牙龈卜啉单胞菌及感染菌株基因型的分析

目的 建立慢性牙周炎（CP）龈下标本中牙龈卟啉单胞菌（Porphyromonas gingivalis,Pg)的PCR检测方法，了解不同患牙龈下菌斑中Pg基因型的差异。方法 采用培养法分离不同患牙龈下菌斑中Pg，同时采用PCR进行Pg 16S rDNA基因、prtC基因和fimA基因的检测。部分扩增产物T－A克隆后测定核苷酸序列。结果 61例患者122个龈下菌斑标本中，Pg 16S rDNA、prtc和fimA分别扩增的阳性率依次为90．6％、81．9％和78．0％，联合扩增的阳性率高达98．4％，培养法阳性率仅为31．1％。30．0％（18／60）患者不同牙位龈下菌斑中的Pg基因型不一致。Pg 16S rDNA、prtC和fimA扩增片段与文献报道的核苷酸序列比较，同源性98．62％－100％。结论 所建Pg PCR检测方法具有较高的敏感性和特异性，可用于慢性牙周炎龈下标本中Pg的快速临床诊断。部分CP患者可被不同基因型的Pg菌株同时感染。     

巢式PCR检测龈下菌斑中HCMV、EBV、HSV-1与慢性牙周炎活动性的关系

目的　建立临床检测龈下菌斑标本中人巨细胞病毒 (HCMV)、Epstein Barr病毒 (EBV)、单纯疱疹病毒 1型 (HSV 1 )巢式PCR方法 ,研究这 3种病毒与慢性牙周炎活动性的关系。方法　收集6 2例慢性牙周炎患者 (男性 2 7例、女性 35例 ,平均年龄 5 3岁 )的牙周炎活动部位、牙周炎静止部位的龈下菌斑 ,提取DNA后使用巢式PCR检测HCMV、EBV、HSV 1 ,比较分析其在同一病人不同部位的检出率。结果　牙周炎活动部位的HCMV检出率为 38.7%,EBV的检出率为 5 8%,HSV 1的检出率为30 .6 %,两种以上病毒合并感染的检出率为 4 0 .3%;牙周炎静止部位的HCMV检出率为 1 4 .5 %,EBV为 2 2 .6 %,HSV 1为 1 1 .3%,两种以上病毒合并感染的检出率为 1 1 .3%。这 3种病毒及其合并感染在牙周炎活动部位的检出率均高于牙周炎静止部位 ,差异有统计学意义 (P <0 .0 5 )。结论　提示HC MV、EBV、HSV 1与慢性牙周炎的活动性相关。     

慢性牙周炎龈下菌斑中牙龈卟啉单胞菌胶原酶水平与牙周病变程度的关系

目的 检测慢性牙周炎（chronic periodontitis，CP）患者龈下菌斑中牙龈卟啉单胞菌（Porphyromonas gingivalis,Pg）胶原酶基因prtC及其产物PrtC，了解PrtC水平与牙周病变程度的关系，确定PrtC诱导细胞分泌炎性细胞因子的作用。方法 采用SDS-PAGE检测原核表达系统重组PnC（rPrtC）表达和Ni-NTA亲和层析法提取的rPrtC纯度。rPrtC免疫家兔获得抗血清。建立多重PCR检测56例CP患者209牙位的龈下菌斑标本中Pg 16S rDNA和prtC基因。建立ELISA检测上述标本中的PrtC，并分析PrtC水平与牙周病变程度的关系。采用ELISA检测rPrtC诱导人脐静脉内皮细胞EVC-304分泌IL-1α、IL-8和TNF-α的作用。结果 rPrtC表达产量约占细菌总蛋白的50％。提纯的rPrtC SDS-PAGE后仅见单一的蛋白条带。96．1％（201／209）和92．3％（1931209）的龈下菌斑标本分别Pg 16S rDNA和prtC基因PCR阳性，91．4％的龈下菌斑标本（191／209）PrtC ELISA阳性。重度CP龈下菌斑标本中PrtC含量明显高于轻度和中度CP标本（P〈0．05），但轻度和中度、中度和重度四标本之间PrtC含量差异无统计学意义（P〉0．05）。1μg的rPrtC作用EVC-304细胞24h后，5和10μg的rPrtC作用EVC-304细胞12h后均可使EVC-304细胞分泌的IL-1α、IL-8和TNF-α水平明显增高（P〈0．05）。结论 Pg有很高的prtC基因携带率和表达率。CP牙周病变程度与龈下PrtC水平密切相关。rPrtC有直接诱导细胞合成并分泌IL-1α、IL-8和TNF-α的活性。     

牙周炎牙龈组织MMP-2、TIMP-1的免疫组化研究

目的　探讨来源于宿主的基质金属蛋白酶MMPs及其抑制因子在牙周炎发病中的作用机制。方法　本研究利用免疫组化方法检测 15例牙周炎患者牙龈组织中和 4例健康牙龈中基质金属蛋白酶 2(MMP 2 )、组织抑制因子 1(TIMP 1)的蛋白表达。结果　 15例成人牙周炎组牙龈组织中MMP 2在上皮内及上皮下的炎性组织中均有阳性表达 ,而且阳性率明显高于正常牙龈 (P <0 .0 5 ) ;TIMP 1在牙周炎以及正常的牙龈组织中表达无明显差异。结论　本研究提示基质金属蛋白酶MMP 2参与牙周组织破坏过程 ,参与牙周炎的病理生理机制     

荧光定量RT-PCR在流感病毒检测上的应用

目的　探讨实时荧光定量RT PCR检测方法在流行性感冒检测诊断上的意义。方法　收集集体暴发疑似流感、SARS患者的咽拭子标本 16起 2 0 7份和双份血清标本 10 4份 ,应用荧光定量RT PCR检测方法、MDCK细胞培养法和血凝抑制试验进行病原学和血清学检测。结果　 2 0 7份集体暴发疑似流感、SARS患者的咽拭子标本中用荧光定量RT PCR检测 ,阳性 79份。阳性率 38 16 % (79 2 0 7)。MDCK细胞培养 ,16起中有 13起共 14 5份咽拭子有 6 2份标本阳性。阳性率 2 9 95 % (6 2 2 0 7)。两者的阳性率差异有显著意义 (χ2 =8.6 4 ,P <0 0 0 5 )。有 9起 10 4份成功的采集了双份血清 ,经HI试验有 6 4份双份血清与H3N2亚型抗原产生血抑 4倍增长 ,阳性率 6 1 5 4 % (6 4 10 4 )。结论　荧光定量RT PCR方法检测流感病毒能够在 3～ 4h内得出结果、且操作方便、特异性强、灵敏度高。因此我们认为实时荧光定量RT PCR方法 ,可作为一种快速的流感病毒检测诊断方法。     

超声龈下刮治在慢性牙周炎患者中的应用

目的:探讨超声龈下刮治在慢性牙周炎患者中的应用效果,为慢性牙周炎的治疗提供参考。方法:回顾性分析2017年9月-2020年8月在我院行龈下刮治的80例慢性牙周炎患者临床资料,根据治疗方式不同,将行手工龈下刮治的患者纳入对照组(n=39),将行超声龈下刮治的患者纳入观察组(n=41)。比较两组治疗前、治疗2个月后的牙面清洁情况,如简化牙石指数(CI-S)、简化软垢指数(DI-S)、菌斑指数(PLI),牙龈情况,包括牙龈指数(Gingival index,GI)、龈沟出血指数(Gingival sulcus bleeding index,SBI),以及牙周情况,如牙周探诊深度(Probing depth,PD)、附着水平(Adhesion level,AL)。结果:与治疗前相比,各治疗组的CI-S、DI-S、PLI、GI、SBI评分以及PD、AL水平均低明显降低(P<0.05),其中观察组更为显著(P<0.05)。结论:超声龈下刮治能为慢性牙周炎患者有效清洁牙面、恢复牙龈健康、改善牙周情况。     

牙龈卟啉单胞菌临床菌株fimA基因变异性和表达频率及其重组表达产物的致炎作用

目的了解牙龈卟啉单胞菌（Porphyromonas gingivalis，Pg）归以基因变异性，构建归以基因原核表达系统，鉴定其表达产物（rFimA）的致炎作用，检测FimA在咯临床菌株中表达频率，了解FimA与慢性牙周炎的关系。方法采用高保真PCR从6株咯临床菌株中扩增fimA基因并测定其核苷酸序列。构建fimA基因原核表达系统，制备rFimA兔抗血清。采用Western blot鉴定rFimA抗原性和免疫反应性。建立ELISA检测38株段临床菌株FimA表达情况和97例慢性牙周炎患者212份龈下菌斑标本中的FimA。检测rFimA诱导人脐静脉内皮EVC-304细胞分泌n1、IL-8、TNF-α和细胞问黏附分子-1（ICAM-1）的作用。结果6株Pg临床菌株fimA基因核苷酸序列完全相同。所构建的原核表达系统rFimA产量高达细菌总蛋白的50％左右。rFimA可与Pg全菌抗血清发生结合反应，免疫家兔可获得高效价抗体。94．7％（36／3S）菌株和91．5％（194／212）龈下菌斑标本ELISA结果阳性。1和10μg的rFimA作用EVC-304细胞48h，其分泌的IL-1α水平升高（P〈0．05）；但作用12h即可出现高水平的ICAM-1（P〈0．05），未发现有诱导IL-8和TNF-α的作用（P〉0．05）。结论 fimA基因序列保守，在Pg临床菌株中有很高的表达频率。rFimA有良好的抗原性和免疫反应性，可作为Pg血清学检测试剂盒和段疫苗的候选抗原。rFimA有较强的诱导细胞分泌ICAM-1的作用。     

应用定量PCR检测固定矫治器拆除后龈下菌斑中牙龈卟啉单胞菌的动态变化

目的 检测正畸患者在拆除固定矫治器后龈下牙龈卟啉单胞菌(Porphyromonas gingivalis)动态含量和牙周临床指标,研究其动态变化及与临床的关系.方法 选择将要结束正畸治疗的患者20名,在拆除矫治器前即时、之后第1个月、第3个月和第6个月分别检查牙周各项指标:菌斑指数(PLI)、龈沟出血指数(SBI)、探诊深度(PD),同时采集龈下菌斑,采用TaqMan探针荧光实时定量PCR技术对样品进行检测得出每个样品中牙龈卟啉单胞菌和总细菌的数量,牙龈卟啉单胞菌检出率和牙龈卟啉单胞菌占总细菌比例的变化.结果 牙龈卟啉单胞菌检出率在拆后6个月内呈下降趋势,在第6个月差异有统计学意义(P<0.05);牙龈卟啉单胞菌的量在拆后6个月开始呈显著的下降(P<0.05);牙龈卟啉单胞菌的百分含量在拆后6个月开始差异有统计学意义(P<0.05);PLI、SBI、PD都呈显著性下降(P<0.05).结论 拆除固定矫治器后在保持良好口腔卫生保健的情况下,正畸患者在一段时间内牙周组织呈自愈的趋势.牙龈卟啉单胞菌的百分含量的动态变化可以较好地反映牙周组织的健康状况.TaqMan实时荧光定量PCR有较高的特异性和敏感性,且快捷准确,对牙周微生物的检测有一定的应用价值.     

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.     

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.     

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.     

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.     

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.     

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.     

Muscle strength and serum testosterone,cortisol and SHBG concentrations in middle-aged and elderly men and women

Forty healthy males (M) and females (F) divided into two different age groups i.e. M50 years (range 44–57; n= 9), F50 years (range 43–54; n= 9), M70 years (range 64–73; n= 11) and F70 years (range 63–73; n= 11) volunteered as subjects for examination of muscle cross-sectional area (CSA) and maximal voluntary isometric force production characteristics of the leg extensor muscles and serum androgen and sex hormone binding globulin (SHBG) concentrations. The CSA in the male groups was greatly larger (P < 0.01) than in the female groups and both elderly groups demonstrated slightly (n.s.) smaller values in the CSA than the two middle-aged groups. Maximal force of 2854 ± 452 N in M50 was greater (P < 0.05) than that of 2627 ± 752 N recorded for F50 as well as the force of 2787 ± 843 in M70 was greater (P < 0.001) than that of 1849 ± 295 recorded for F70. The force between F50 and F70 differed significantly (P < 0.05) from each other. The maximal rate of force production in M50 was greater (P < 0.01) than in F50 as well as in M70 greater (P < 0.001) than in F70. Both middle-aged groups demonstrated greater (P < 0.05) values than the respective elderly groups of the same sex. The individual values in the CSA correlated with the values in maximal force both in the middle-aged subjects (r= 0.66; P < 0.01) and in the elderly subjects (r= 0.69; P < 0.01). The mean concentration of serum testosterone in M50 was slightly (n.s.) greater than in M70 and in F50 significantly (P < 0.05) greater than in F70. Serum SHBG levels were lower in the males (P < 0.01) than in the females and serum testosterone/SHBG ratio in M70 and in F70 were lower (P < 0.05) than in M50 and in F50, respectively. In the females significant positive correlations were observed between the individual values in serum testosterone concentration and the values both in the CSA (r= 0.46; P < 0.05) and in maximal force (r= 0.62; P < 0.01) as well as between serum testosterone/SHBG ratio and both the CSA (r= 0.55; P < 0.05) and maximal force (r= 0.68; P < 0.01). The present results imply that the decreasing basal level of blood testosterone over the years in aging people, especially in females, may lead to decreasing anabolic effects on muscles thus having an association with age-related declines in the maximal voluntary neuromuscular performance capacity in aging people.