PI3K信号通路对T细胞发育、活化、增殖、分化及支气管哮喘的作用

T细胞是参与支气管哮喘发病的重要效应细胞,而磷脂酰肌醇-3-激酶(PI3K)是T细胞的重要信号转导分子.PI3K信号通过影响双阴性细胞的β-选择而影响T细胞的成熟,还通过激活PKB、Rac等信号途径而参与T细胞的活化、分化.同时,PI3K通过参与Th1/Th2失衡的调节,嗜酸粒细胞、肥大细胞的黏附、脱颗粒等而参与支气管...     

磷脂酰肌醇3激酶信号转导途径及在支气管哮喘中的作用

磷脂酰肌醇3激酶（PI3K）信号转导通路是参与支气管哮喘（哮喘）发病机制的一条重要受体信号转导途径。在哮喘患者体内,通过这一途径影响气道平滑肌的增殖并对T细胞受体和协同刺激因子受体CD28介导的T细胞的分化、生存、活化和细胞因子的产生起了关键性的作用。这一机制的研究旨在阐明PI3K信号转导通路在哮喘气道重构中的作用,以及相应的拮抗剂的研究,为哮喘的治疗提供了新方向。     

磷脂酰肌醇3激酶信号转导途径及在支气管哮喘中的作用

磷脂酰肌醇3激酶（PI3K）信号转导通路是参与支气管哮喘（哮喘）发病机制的一条重要受体信号转导途径。在哮喘患者体内，通过这一途径影响气道平滑肌的增殖并对T细胞受体和协同刺激因子受体CD28介导的T细胞的分化、生存、活化和细胞因子的产生起了关键性的作用。这一机制的研究旨在阐明PI3K信号转导通路在哮喘气道重构中的作用，以及相应的拮抗剂的研究，为哮喘的治疗提供了新方向。     

磷脂酰肌醇3-激酶途径对支气管哮喘大鼠气道平滑肌细胞增殖的影响及罗红霉素的干预作用

气道蘑塑是支气管哮喘(简称哮喘)的重要病理特征,气道平滑肌细胞(airway smooth muscle cells,ASMCs)增生和肥大在哮喘气道重塑中发挥了重要作用[1].磷脂酰肌醇3-激酶(phosphoinositide 3-kinases,PI3 K)途径是介导ASMCs增殖重要信号转导途径[2].罗红霉素是新一代大环内酯类抗生素,初步研究结果表明,罗红霉素能影响哮喘气道重塑,但具体机制尚不明确.本研究通过复制大鼠慢性哮喘模型,研究PI3K的重要下游信号分子Akt、p70S6K及cyclinD1活性变化,并给予PI3K特异性抑制剂渥曼青霉素(wortmannin)及罗红霉素干预,探讨PI3K信号途径在哮喘ASMCs增殖中的作用及罗红霉素对哮喘气道重塑的影响,进一步揭示哮喘的发病机制及有效的干预措施.     

1,25-二羟维生素D3与支气管哮喘

支气管哮喘的免疫机制受多种因素的调节,其中涉及到Th1／Th2平衡紊乱等因素。目前已知1,25-二羟维生素D3对于Th1细胞起主导作用的疾病中有着重要意义,但其对于Th2细胞起主导作用的疾病如支气管哮喘的作用目前还没有足够的研究。本文首先描述了1,25-二羟维生素D3对于哮喘气道炎症的影响,然后介绍了其对于CD4^＋调节T细胞的两个主要亚群：自然调节性T细胞尤其是获得性调节性T细胞的作用,接着介绍了1,25-二羟维生素D3对于树突状细胞的影响和作用,以及其对于T细胞迁移方面的影响。了解1,25-二羟维生素Ds在支气管哮喘中的作用及免疫调节机制,有助于开拓哮喘治疗的新方法。     

1,25-二羟维生素D3与支气管哮喘

支气管哮喘的免疫机制受多种因素的调节,其中涉及到Th1/ Th2 平衡紊乱等因素.目前已知1,25-二羟维生素D3对于Th1细胞起主导作用的疾病中有着重要意义,但其对于Th2细胞起主导作用的疾病如支气管哮喘的作用目前还没有足够的研究.本文首先描述了1,25-二羟维生素D3对于哮喘气道炎症的影响,然后介绍了其对于CD4+调节T细胞的两个主要亚群:自然调节性T 细胞尤其是获得性调节性T 细胞的作用,接着介绍了1,25-二羟维生素D3对于树突状细胞DC的影响和作用,以及其对于T细胞迁移方面的影响.了解1,25-二羟维生素D3在支气管哮喘中的作用及免疫调节机制,有助于开拓哮喘治疗的新方法.     

辅助性T细胞在支气管哮喘发病机制中的作用

支气管哮喘(简称哮喘)是一种由多种细胞和细胞因子参与的免疫失衡性的变态反应性疾病,调节性T细胞是近10年来发现的一类在哮喘发病中起重要作用的T淋巴细胞[1].本文研究了哮喘患者Th3等辅助性T细胞亚群的数量和功能的变化,旨在研究Th3等辅助性T细胞在哮喘发病机制中的作用.     

信号转导子和转录激活子6、过氧化物酶体增殖，活化体受体-γ与支气管哮喘

Th1／Th2细胞比例失调和Th2细胞优势分化是支气管哮喘发病的主要机制。信号转导子和转录激活子6（STAT6）是Th2细胞特异性转录因子，被IL-4等激活后诱导相关炎症基因的表达：STAT6信号通路在支气管哮喘气道炎症和高反应性中起重要作用。过氧化物酶体增殖活化体受体-γ（PPAR-γ）可通过抑制炎症信号通路，减轻气道炎症并抑制气道重构等。本文综述了STAT6在哮喘炎症中的作用及PPAR-γ对支气管哮喘炎症等方面的影响，为哮喘的临床治疗提供新的思路。     

金水宝胶囊对支气管哮喘患者几种免疫细胞因子的影响

支气管哮喘是一种慢性炎症性气道疾病,免疫因素在哮喘的发病过程中发挥重要作用。以往认为辅助性T淋巴细胞Th1/Th2比例失衡是哮喘发病的重要机制。近年发现了一种以产生IL-17为主要细胞因子的Th17细胞,在哮喘的发病机制中同样具有重要作用,IL-17对于中性粒细胞参与的支气管哮喘气道炎症、气道高反应、气道重塑均发挥重要作用,有可能成为治疗哮喘的有意义的靶目标[1-3]。对支气管     

PI3K与支气管哮喘发作期T细胞增殖周期蛋白关系的研究进展

T细胞是支气管哮喘(简称哮喘)发病机制中的核心细胞.T细胞增殖周期异常在哮喘中发挥着重要作用.PI3K信号转导途径是T细胞内重要的信号转导途径,与细胞周期蛋白异常密切相关,其机制的研究对于哮喘的治疗有重要的意义.     

Clinical trials update: highlights of the scientific sessions of The American College of Cardiology 2002: LIFE,DANAMI 2, MADIT-2, MIRACLE-ICD,OVERTURE, OCTAVE,ENABLE 1 & 2, CHRISTMAS,AFFIRM, RACE,WIZARD, AZACS,REMATCH, BNP trial and HARDBALL

This article continues a series of reports updating recent research developments of particular interest to personnel involved in the treatment and management of patients with heart failure. This is a summary of selected presentations made at the American College of Cardiology 51st Annual Scientific Session held in Atlanta on 17-20 March 2002. Reports of the following clinical studies are included: LIFE, DANAMI 2, MADIT-2, MIRACLE-ICD, OVERTURE, OCTAVE, ENABLE 1 & 2, CHRISTMAS, AFFIRM, RACE, WIZARD, AZACS, REMATCH, BNP trial and HARDBALL.     

Electrochemical Recovery and Behaviors of Rare Earth (La,Ce, Pr,Nd, Sm,Eu, Gd,Tb, Dy,Ho, Er,Tm, and Yb) Ions on Ni Sheets

The electrochemical behaviors of rare earth (RE) ions have extensively been studied because of their high potential applications to the reprocessing of used nuclear fuels and RE-containing materials. In the present study, we fully investigated the electrochemical behaviors of RE(III) (La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, and Yb) ions over a Ni sheet electrode in 0.1 M NaClO₄ electrolyte solution by cyclic voltammetry between +0.5 and −1.5 V (vs. Ag/AgCl). Amperometry electrodeposition experiments were performed between −1.2 and −0.9 V to recover RE elements over the Ni sheet. The successfully RE-recovered Ni sheets were fully characterized by scanning electron microscopy, energy dispersive X-ray spectroscopy, Fourier transform infrared spectroscopy, X-ray photoelectron spectroscopy, and photoluminescence spectroscopy. The newly reported recovery data for RE(III) ions over a metal electrode provide valuable information on the development of the treatment methods of RE elements.     

Prevalence,Self-Awareness,Treatment, and Control of Hypertension in Lhasa,Tibet

To investigate the prevalence, self-awareness, and treatment of hypertension in Lhasa, Tibet, a total of 1370 native Tibetan aged ≥18 years were selected, using stratified proportional sampling. The study showed that the prevalence of hypertension was 51.2%, significantly higher in men (56.0%) than in women (48.0%) (P = .004). The hypertension prevalence increased with increasing age (77.8% in 60–74 y and 82.5% in ≥75 y groups) and was higher in urban, suburban, or agricultural area than in pastoral area (P < .001). The self-awareness, treatment, and control rate of hypertension were 63.5%, 24.3% and 7.7%, respectively. In multivariable regression analysis, age, urban residence, amount of daily intake of fat and oil, and body mass index <18.5 kg/m² were independently associated with hypertension. In conclusion, hypertension was highly prevalent among native Tibetan people in Lhasa, and the rates of self-awareness, treatment, and control of hypertension were low.     

Lack of effect of colesevelam HCl on the single-dose pharmacokinetics of aspirin,atenolol, enalapril,phenytoin, rosiglitazone,and sitagliptin

Aims

Drug interactions with bile acid sequestrants are primarily due to the potential of these agents to bind to concomitant drugs. Six clinical studies were performed to determine the effects of colesevelam on the pharmacokinetics of aspirin, atenolol, enalapril, phenytoin, rosiglitazone, and sitagliptin.

Methods

All six studies enrolled healthy subjects aged 18–45 years. The phenytoin study used a single-dose, three-period crossover design (phenytoin alone, phenytoin simultaneously with colesevelam, and phenytoin 4 h before colesevelam). The other studies used a two-period crossover design (test drug alone and test drug simultaneously with colesevelam). Colesevelam (3750 mg once daily) was dosed throughout the pharmacokinetic sampling period. After each single dose of the test drug, serial blood samples were collected for determination of plasma drug concentrations and calculation of pharmacokinetic parameters.

Results

For all six test drugs, 90% CIs for geometric least-squares mean ratios of AUC and C_max for the measured analytes were within specified limits, indicating no interaction between the test drug and colesevelam.

Conclusions

Aspirin, atenolol, enalapril, rosiglitazone, and sitagliptin may be taken with colesevelam. Although the phenytoin study indicated no pharmacokinetic interaction, phenytoin should continue to be taken ≥4 h before colesevelam in accordance with current prescribing information.     

Clinical trials update from the American College of Cardiology 2008: CARISMA, TRENDS, meta-analysis of Cox-2 studies, HAT, ON-TARGET, HYVET, ACCOMPLISH, MOMENTUM, PROTECT, HORIZON-HF and REVERSE

This article provides information and a commentary on trials relevant to the pathophysiology, prevention and treatment of heart failure, presented at the American College of Cardiology. Unpublished reports should be considered as preliminary data, as analyses may change in the final publication. CARISMA investigated the use of implantable loop recorders for detecting life-threatening arrhythmias in patients with LVSD after MI and found that brady- and ventricular tachy-arrhythmias predicted an adverse prognosis. The TRENDS study showed that the burden of atrial fibrillation detected by pacemakers or defibrillators predicted the risk of embolic events but not with sufficient precision to justify changes in anti-thrombotic management. A meta-analysis of six trials reported an increased cardiovascular risk associated with celecoxib, particularly for heart failure, which was related to dose and baseline cardiovascular risk. The HAT study failed to show a benefit of providing post-MI patients with a home defibrillator. MOMENTUM, a study of a device designed to augment aortic blood flow, was stopped early due to increased bleeding risk. Results from PROTECT support the use of rolofylline 30 mg/day in acute heart failure, a definitive study is now underway. Istaroxime, an agent that appears to have both inotropic and lusitropic effects, improved haemodynamics when added to standard therapy in patients stabilised after admission with heart failure in HORIZON-HF. The REVERSE study suggested that CRT improves ventricular function and reduces morbidity even in patients with few or no symptoms of heart failure and may delay or prevent worsening heart failure.     

Biliary microlithiasis,sludge,crystals,microcrystallization,and usefulness of assessment of nucleation time

BACKGROUND:The process of microcrystallization,its sequel and the assessment of nucleation time is ignored.This systematic review aimed to highlight the importance of biliary microlithiasis,sludge,and crystals,and their association with gallstones,unexplained biliary pain,idiopathic pancreatitis, and sphincter of Oddi dysfunction.DATA SOURCES:Three reviewers performed a literature search of the PubMed database.Key words used were"biliary microlithiasis","biliary sludge","bile crystals","cholesterol crystallisation","bile microscopy","microcrystal formation of bile","cholesterol monohydrate crystals","nucleation time of cholesterol","gallstone formation","sphincter of Oddi dysfunction"and"idiopathic pancreatitis".Additional articles were sourced from references within the studies from the PubMed search.RESULTS:We found that biliary microcrystals account for almost all patients with gallstone disease,7%to 79%with idiopathic pancreatitis,83%with unexplained biliary pain, and 25%to 60%with altered biliary and pancreatic sphincter function.Overall,the detection of biliary microcrystals in gallstone disease has a sensitivity ranging from 55%to 87%and a specificity of 100%.In idiopathic pancreatitis,the presence of microcrystals ranges from 47%to 90%.A nucleation time less than 10 days in hepatic bile or ultra-filtered gallbladder bile has a specificity of 100%for cholesterol gallstone disease.CONCLUSIONS:Biliary crystals are associated with gallstone disease,idiopathic pancreatitis,sphincter of Oddi dysfunction, unexplained biliary pain,and post-cholecystectomy biliary pain.Pathways of cholesterol super-saturation,crystallisation, and gallstone formation have been described with scientificsupport.Bile microscopy is a useful method to detect microcrystals and the assessment of nucleation time is a good method of predicting the risk of cholesterol crystallisation.