芦荟苷通过调控MAPKs信号通路诱导胃癌细胞凋亡

目的探讨芦荟苷对人胃癌MKN-28和HGC-27细胞凋亡的诱导作用及可能的分子机制。方法胃癌MKN-28和HGC-27 细胞用含10%胎牛血清和NEAA（HGC-27细胞）的1640完全培养基常规培养,不同浓度的芦荟苷处理胃癌MKN-28和HGC-27 细胞特定的时间,CCK-8 实验检测芦荟苷对MKN-28 和HGC-27 细胞活力的影响;DAPI染色观察凋亡细胞核的形态改变; AnnexinV-FITC/PI双染法检测细胞凋亡率;Western blotting检测凋亡相关蛋白PARP和procaspase-3的表达及MAPKs信号通 路p38,ERK及JNK的磷酸化水平;p38,ERK及JNK的特异性抑制剂处理细胞,WB检测抑制剂的对p38,ERK及JNK激活的抑 制效果,DAPI染色观察抑制剂对胃癌细胞凋亡的影响。结果芦荟苷浓度依赖性地抑制胃癌MKN-28和HGC-27细胞的活力, 诱导胃癌细胞凋亡;芦荟苷处理胃癌细胞后,胞内JNK和p38的磷酸化水平明显增加,而ERK的磷酸化水平下降。特异性抑制 剂阻断ERK活化,能够增强芦荟苷诱导的细胞凋亡,阻断p38和JNK的激活,能够部分逆转芦荟苷诱发的胃癌细胞凋亡。结论 芦荟苷通过激活JNK和p38信号途径,抑制ERK信号途径诱导胃癌细胞凋亡。     

低氧激活ERK／JNK通路促进Smad2／3蛋白磷酸化诱导小鼠心脏成纤维细胞表型转换的实验研究

目的研究体外低氧诱导小鼠心脏成纤维细胞（cardiac fibroblasts,CFs）向心脏肌成纤维细胞（cardiac myofibroblasts,CMFs）表型转换过程中,促分裂素原活化蛋白激酶（mitogen-activated protein kinases,MAPK）信号通路与Smad2／3蛋白磷酸化的关系。方法新生小鼠第1代CFs低氧（37℃、3％O2）无血清培养48h,免疫荧光检测α-SMA蛋白;新生小鼠CFs给予3种MAPK（ERK、JNK和p38）特异性抑制剂常氧培养1h,进行低氧培养30min,免疫印迹检测ERK、JNK、p38和Smad2／3蛋白磷酸化水平。结果①低氧显著上调新生小鼠CFs中α-SMA蛋白的表达;②低氧能显著地促进ERK、JNK和P38蛋白磷酸化,PD98059（ERK特异性抑制剂）、SP600125（JNK特异性抑制剂）和SB203580（P38特异性抑制剂）能抑制低氧诱导的ERK、JNK和P38蛋白的磷酸化;③PD98059（ERK特异性抑制剂）和SP600125（JNK特异性抑制剂）能抑制低氧诱导的Smad2／3蛋白的磷酸化,SB203580（P38特异性抑制剂）无此作用。结论①低氧可诱导小鼠CFs细胞发生表型转化为CMFs;②ERK和JNK信号通路能调控Smad2／3蛋白的磷酸化表达;③MAPK和Smad信号通路可能参与低氧诱导的小鼠CFs细胞的表型转化。     

阿霉素可通过MAPK信号转导通路促进成骨肉瘤细胞凋亡

目的: 探讨阿霉素在适宜的加药浓度、作用时间下诱导成骨肉瘤细胞凋亡的分子机制.方法: 首先通过FCM,MTT等方法探讨引起成骨肉瘤细胞凋亡的最佳药物作用浓度及时间;在此条件下应用不同信号转导通路的抑制剂观察导致细胞凋亡的可能通路;最后应用Western-Blotting来检测在成骨肉瘤细胞凋亡过程中相关信号分子的表达水平及磷酸化水平的变化.结果: 0.4 mg/L阿霉素作用成骨肉瘤细胞12 h即可引起细胞凋亡,并呈时间依赖性;用p38的抑制剂SB203580和MEK4/7的抑制剂U0126可明显抑制细胞的凋亡;Western Blotting检测发现阿霉素作用于细胞后,MAPK家族成员JNK、ERK和p38等各激酶的表达水平未发生明显变化,但JNK,p38的磷酸化水平提高了ERK的磷酸化水平有所下降;用Western Blotting检测到阿霉素作用后p53蛋白的表达水平有提高.结论: 阿霉素可导致成骨肉瘤细胞凋亡,而且此凋亡过程与MAPK通路有关.     

过表达α1,3-岩藻糖基转移酶Ⅶ通过增强p38MAPK信号通路抑制UVC照射诱导的人肝癌SMMC-7721细胞的凋亡

 目的 初步探讨α1,3-岩藻糖基转移酶Ⅶ（简称FUT7）在UVC照射诱导的人肝癌SMMC-7721(简称7721)细胞凋亡过程中的作用及机制。方法 用RT-PCR检测转染pcDNA3-FUT7质粒的7721细胞及转染空质粒pcDNA3的7721细胞中FUT7基因的转录水平；用流式细胞仪检测细胞表面FUT7产物SLex的表达水平；利用DAPI染核计算UVC照射后细胞的凋亡比率；用结晶紫染色法测定细胞的存活率；利用Western blot检测Caspase3的剪切情况及p38MAPK、JNK1/2和ERK1/2的磷酸化水平。结果 过表达FUT7能抑制UVC照射诱导的7721细胞凋亡，同时还增强了细胞中p38MAPK信号通路的活性，而用p38MAPK的特异性抑制剂处理则可削弱FUT7的抗凋亡作用。结论 在UVC照射诱导的7721细胞凋亡过程中FUT7具有抗凋亡的作用，这种作用可能部分通过增强p38MAPK信号通路活性而实现。     

H_2O_2通过上调P38的活性而诱导PC12细胞凋亡

目的:探讨H2O2是否通过调节P38MAPK的活性而诱导PC12细胞凋亡。方法:碘化丙啶(PI)染色流式细胞术(FCM)检测细胞凋亡;Western-Blot测定磷酸化ERK1/2蛋白和磷酸化p38蛋白的表达。结果:作用PC12细胞24h后,20～80μmol/L的H2O2可呈浓度依赖性地诱导PC12细胞凋亡并增加PC12细胞P38磷酸化的水平;P38特异性抑制剂SB203580(10或20μmol/L)预处理30min可显著减轻40μmol/LH2O2对PC12细胞凋亡的诱导作用。结论:H2O2通过上调P38的活性而诱导PC12细胞凋亡。     

黄芩苷通过激活JNK/p38 MAPK通路诱导ALL Reh细胞凋亡

目的探究黄芩苷对急性淋巴细胞白血病(ALL)细胞株Reh增殖和凋亡的影响及c-Jun氨基蛋白激酶(JNK)/p38丝裂原活化蛋白激酶(p38 MAPK)通路在其机制中的作用。 方法黄芩苷处理或联合活性氧(ROS)清除剂NAC共处理Reh细胞；流式细胞术检测细胞凋亡、胞内ROS水平和线粒体膜功能(MMP)；免疫荧光实验观察凋亡细胞的数目及其形态变化。Western blotting免疫印迹检测Reh细胞内凋亡蛋白和信号通路蛋白的表达水平。 结果与对照组比较,黄芩苷组Reh细胞增殖被抑制,细胞凋亡率、促凋亡蛋白、ROS、JNK和p38磷酸化水平显著上升,抗凋亡蛋白表达下调,MMP明显受损(P＜0.01)。NAC清除ROS后明显恢复细胞增殖,JNK和p38磷酸化水平明显下降,Survivin表达恢复(P＜0.01)。 结论黄芩苷经激活JNK/p38 MAPK通路活化Caspase3/7,诱导Reh细胞凋亡。     

蛇床子素抑制LPS诱导的肠上皮细胞株Caco2的炎症反应

目的：探讨蛇床子素(osthole)对内毒素(lipopolysaccharide,LPS)诱导的肠上皮细胞Caco2中炎症因子表达的影响及机制。方法：培养Caco2细胞,用LPS诱导炎症反应。在LPS刺激前给予细胞不同浓度的蛇床子素处理,通过real-time PCR检测白介素(interleukin,IL)-1β、IL-6和肿瘤坏死因子(tumor necrosis factor,TNF)-α的表达情况。分别用PKA抑制剂H89和KT5720处理细胞,观察cAMP/PKA信号通路对蛇床子素效应的影响;用Western blot检测细胞中p38、Erk和JNK的磷酸化水平。结果：LPS刺激可以显著增加Caco2细胞中炎症因子IL-1β、IL-6和TNF-α的表达。蛇床子素预处理对LPS诱导的炎症反应有明显抑制作用,PKA抑制剂H89和KT5720不能逆转蛇床子素的抑制作用。LPS刺激后,Caco2细胞中p38、Erk和JNK的磷酸化水平明显增加,蛇床子素可部分抑制它们的磷酸化。结论：蛇床子素具有抑制肠上皮细胞株Caco2炎症反应的效应,该效应不依赖于cAMP/PKA,可能与抑制Erk、JNK和p38的磷酸化有关。     

MRP8/MRP14诱导腹腔巨噬细胞释放炎性细胞因子

目的 探讨MRP8/MRP14诱导小鼠腹腔巨噬细胞细胞因子表达效应及其作用机制.方法 Luminex xMAP液相芯片系统检测重组MRP8/MRP 14蛋白诱导腹腔巨噬细胞6种细胞因子/趋化因子的水平变化;MRP14不同结构域融合蛋白刺激细胞,检测TNF-α、IP-10和IL-6表达;Western blot检测MRP8/MRP14刺激细胞p38MAPK、JNK和ERK激酶磷酸化变化;细胞预先用p38MAPKs、JNK、ERK激酶抑制剂、TLR4和RAGE受体拮抗剂预处理,之后给予MRP8/MRP14蛋白刺激,检测TNF-α、IP-10和IL-6表达.结果 MRP8/MRP14能显著诱导TNF-α、IP-10和IL-6的表达,与对照组相比,蛋白表达水平分别升高约98.2、378.6和6.3倍(P＜0.01),MRP8/MRP14不能诱导IL-2、IL-5和IFN-g的表达;MRP14全长及其结构域EFhand-1、EFhand-2及EFhand-1+2融合蛋白能够诱导TNF-α、IP-10和IL-6的表达(P＜0.01),CT末端结构域不具有诱导活性;MRP8/MRP 14刺激细胞后1 h p38 MAPK、JNK及ERK激酶发生显著磷酸化变化,持续至2h;与单纯MRP8/MRP 14组相比,p38MAPK抑制剂SB203580显著抑制TNF-α、IP-10和IL-6的表达(P＜0.05);JNK抑制剂SP600125显著抑制TNF-α和IP-10的表达(P＜0.05),对IL-6的表达无影响;ERK及其上游MEK1/2的抑制剂PD98059和U0126显著抑制IL-6的表达(P＜0.05);TLR4抑制剂TAK242抑制了MRP8/MRP14诱导的TNF-α、IP-10和IL-6的表达(P＜0.05),而RAGE中和性抗体仅部分抑制MRP8/MRP14诱导的IL-6的表达(P＜0.05).结论 MRP8/MRP14能够诱导小鼠腹腔巨噬细胞TNF-α、IP-10和IL-6的表达;MRP蛋白以包含有钙离子结合基序的结构域具有诱导细胞因子表达的活性;TNF-α和IP-10的表达与TLR4受体及其下游的p38MAPKs、JNK通路有关,IL-6的表达则同时由TLR4和RAGE受体介导,继而激活下游的p38MAPKs和ERK信号通路.     

桔梗皂甙D对人胃癌细胞SGC7901增殖的抑制作用和机制研究

[目的]探讨桔梗皂甙D(platycodin D,PD)对人胃癌细胞株SGC7901增殖的抑制作用及作用机制。[方法]体外培养人胃癌细胞株SGC7901,加入终浓度分别为5~20μm·L-1的PD。采用MTT法测定药物对细胞增殖的抑制作用,Annexin V/PI双标法检测细胞凋亡率,JC-1检测线粒体膜电位的变化,Western blot检测PD对凋亡相关蛋白cleaved caspase-3、cleaved caspase-9、cleaved PARP、bcl-2、bax和对MAPK信号通路蛋白ERK、JNK、p38及其磷酸化蛋白p-ERK、p-JNK、p-p38表达的影响。[结果]MTT结果显示,PD作用24h和48h后,PD对SGC7901细胞增殖的抑制随浓度的增加而增强;PD作用SGC7901后,细胞凋亡率明显增加,线粒体膜电位降低。Western blot检测结果显示cleaved PARP、cleaved caspase-3、cleaved caspase-9、bax蛋白表达量随着药物浓度的增加而升高,bcl-2蛋白表达下降,同时p-JNK、p-p38水平明显升高,p-ERK蛋白水平下降,ERK、JNK、p38蛋白的表达无明显变化。[结论]PD对胃癌细胞SGC7901有抑制增殖和诱导凋亡的作用。PD通过抑制ERK信号通路从而抑制细胞增殖,通过激活JNK和p38信号途径调控bax和bcl-2表达,导致线粒体膜电位下降,进而激活caspase,诱导癌细胞凋亡的发生。     

内脏脂肪素对巨噬细胞MMP-9的作用及其机制探讨

目的 研究内脏脂肪素（visfatin）对巨噬细胞基质金属蛋白酶-9（MMP-9）的作用及其机制。方法体外诱导THP-1单核细胞转化为巨噬细胞。为明确visfatin对MMP-9的作用,细胞分为两组：①巨噬细胞+visfatin 12 h组;②巨噬细胞+visfatin24 h组,两组的visfatin的质量浓度均为：0（对照组）、50、100、200、400 ng/mL。采用RT-PCR和Western blotting测定MMP-9基因和蛋白表达,明胶酶谱法检测MMP-9的活性。为明确visfatin对MMP-9的作用机制,细胞分为五组：①巨噬细胞未加刺激组（对照组）;②巨噬细胞+ MAPK p38、ERK1/2、JNK信号通路抑制剂预处理1 h后加visfatin（200 ng/mL）24 h组;③巨噬细胞+过氧化物酶体增殖剂活化受体（PPARγ）天然及人工配体/ RXR配体预处理1 h后加visfatin（200 ng/mL）24 h组;④巨噬细胞+visfatin（200 ng/mL）24 h组（Vis200组）;⑤巨噬细胞+visfatin（200 ng/mL）刺激不同时间组（5、10、15、30、60 min）。Western blotting检测MMP-9蛋白和PPARγ蛋白表达及visfatin刺激下巨噬细胞p38、ERK1/2、JNK MAPK磷酸化水平。结果 Visfatin能促进MMP-9基因及蛋白表达（P<0.05,P<0.01）,同时增强了MMP-9的活性（P<0.01）。p38 MAPK、ERK1/2 MAPK通路抑制剂及RXR配体抑制visfatin对MMP-9表达具有上调作用;visfatin能促进p38 MAPK和ERK1/2 MAPK的磷酸化,但不影响PPARγ蛋白的表达。结论 Visfatin增加了巨噬细胞炎症因子的表达,该作用与p38 MAPK和ERK1/2MAPK信号通路有关;RXR可能参与了该过程。     

Value of D-Dimers in patients with acute aortic dissection

Objective: To evaluatel the value of D-dimers in patients with acute aortic dissection (AAD). Methods: This study consisted of 16 patients with AAD and 27 non-AAD patients. Serum D-dimets were measured by Sta-Liatest D-DI immunoturbidimetric assay. Results: D-dimer level was higher (P ＜ 0.001) in patients with AAD(7.91 ± 5.52 μg/ml) than that in non- AAD group(1.57±1.24 μg/ml). D-dimer was positive (＞0.4 μg/ml) in all patients with AAD and in 10 control group patients (37%). Among patients with acute AAD, D-dimers tended to be higher in Stanford A than in Stanford B (8.67 ± 4.31 μg/ml vs. 3.24±1.27 μg/ml, P ＜0.01). D-dimer values tended to be higher in more extended disease(3.84 ± 1.65 μg/ml, 8.57 ± 3.58 μg/ml and 11.87 ± 5.69 μg/ml in thoracic aorta, thoracic and abdominal aorta, thoracic and abdominal aorta and iliacal arteries, respectively, P ＜ 0.05 for both 8.57 ± 3.58 and 11.87 ± 5.69 vs. 3.84 ± 1.65 ). Including the control group into the analysis, we found a sensitivity of 100%, a negative predictive value of 100%, and a specificity of 66% and a positive predictive value of 64% for D-dimer in diagnosis of AAD in our patients with suspected AAD. Conclusion: D-dimer was elevated in patients with AAD. A negative D-dimer test result could be useful in excluding AAD.     

Research of combined liver-kidney transplantation model in rats

Objective： To set up a simple and reliable rat model of combined liver-kidney transplantation. Methods： SD rats served as both donors and recipients. 4℃ sodium lactate Ringer＇s was infused from portal veins to donated livers,and from abdominal aorta to donated kidneys, respectively. Anastomosis of the portal vein and the inferior vena cava （IVC） inferior to the right kidney between the graft and the recipient was performed by a double cuff method, then the superior hepatic vena cava with suture. A patch of donated renal artery was anastomosed to the recipient abdominal aorta. The urethra and bile duct were reconstructed with a simple inside bracket. Results： Among 65 cases of combined liver-kidney transplantation, the success rate in the late 40 cases was 77.5%. The function of the grafted liver and kidney remained normal. Conclusion： This rat model of combined liver-kidney transplantation can be established in common laboratory conditions with high success rate and meet the needs of renal transplantation experiment.     

Development on Adjustable Calibration Marker for Shock Wave Focus

Shock wave lithotripsy （SWL） is a treatment of choice for upper urinary stones. However, this procedure is inappropriate for obese patients because the focus is often unable to reach the target owing to the limited focal distance in shock wave source. Although treating such patients in a blast path may increase the application length of shock wave source, it＇s difficult to find this path on the lithotripter monitor. For this reason, we invented an adjustable calibration marker in order to set an effective focus in the shock wave hath.     

Study on the TCM Pathogenesis of Angiopathic Complications of Type II Diabetes

Excess production of reactive oxygen species(ROS)of mitochondrion mediated by hyperglycemia is the common pathogenesis of angiopathic complications of diabetes.TCM holds that the damp from the dysfunction of spleen.kidney and liver is the causative factor of complications of diabetes.This is similar to the mechanism of Ros resulting in angiopathic complications of diabetes.When the angiopathic complications of type II diabetes mellitus(T2DM)are difierentiated as caused by turbid damp in TCM can be explained as ROS.Since the obstruction of pathogenic damp in channels and collaterals is said to be the main pathogenesis,the treating principle should be dissolving the damp to remove the obstruction.     

Leptin, Ghrelin and TNF-α before and after Hypo-caloric Traditional Chinese Diet and Auricular Acupuncture

INTRODUCTION Obesity is a complex emergent problem, which can be possibly solved not only by the diet but also by the life style and promotion of a constant physical exercise. 1, 2 No doubt careful attentions must be given to the nutritional condition of obese people, the dietary habits, the somatic build (i.e. distribution of fat mass) and the organic functions linked to formation of the fat mass. All the parameters should be constantly monitored before, during and after a diet treatment. 3, 4, 5     

Relationship between Dysglycemia and Carotid Atherosclerosis in Tibetan Population

People with dysglycemia are at high risk for atherosclerotic diseases. This study aims at investigating the atherosclerotic vascular damage in dysglycemia and its metabolic origin in Tibetan population.     

APPLICATION OF LORNOXICAM TO PATIENT-CONTROLLED ANALGESIA IN PATIENTS UNDERGOING ABDOMINAL SURGERIES

FOR anesthesiologis s ,treatingpostoperativepainhas alwaysbeen a problem.Althoughopioidshave been provedtobe effective,theirsideeffectscouldnotbeignored.With thedevelopmentofscienceand pharmacology,many drugs with aspectsof satisfactoryanalgesicefficacyand couldbe welltoleratedby patientshave been developed.And lornoxicamisone of them, which isa non-steroidalanti-inflammatorydrug (NSAID ), with analgesic, anti-infl-ammatory,andantipyreticproperties.Itseliminationhalf-time(3 to 5 hours) isle…     

安心颗粒对急诊经皮冠状动脉介入术后生活质量影响的研究

目的：评价使用安心颗粒对急诊经皮冠状动脉介入术（PPCI）术后生活质量的影响.方法：将160例接受PPCI的急性ST段抬高型心肌梗死患者随机分为安心颗粒组（术前顿服安心颗粒8.8g,术后安心颗粒4.4 g/次,每日2次）和对照组（仅接受基础药物治疗）.所有患者均服用阿司匹林、氯吡格雷和阿托伐他汀.分别在入院时、出院前1d、出院后180 d时,应用心肌梗死多维度量表（MIDAS）、中文版SF-36评价量表对患者生活质量评分.并观察术后30 d以内的出血并发症、血小板减少症发生情况.结果：入院时和出院前1d,两组患者的心肌梗死MIDAS、SF-36量表评分比较无差异（P＞0.05）;出院后180 d时,与对照组比较,安心颗粒组MIDAS、SF-36评分明显减低（P＜0.05）;组内与入院时比较,两组出院前1d、出院后180 d时,MIDAS、SF-36评分均降低（P＜0.05）.两组患者在随访期间均无大量出血、少量出血、重度和极重度血小板减少症发生,安心颗粒组有4例、对照组有7例发生不明显出血（P＞0.05）.两组发生轻度血小板减少症的患者数比较无差异（P＞0.05）.结论：PPCI使用安心颗粒,能改善急性ST段抬高型心肌梗死患者的生活质量,且不增加出血风险.     

CLINICAL SIGNIFICANCE OF SERUM CYTOKINES IL-1β,sIL-2R,IL-6,TNF-α,AND IFN-v IN ACUTE CORONARY SYNDROME

Objectives To explore serum cytokines levels (including IL-1 β, sIL-2R, IL-6, TNF-α, and IFN-v) and their significance in patients with acute coronary syndrome (ACS) and the subsequent follow-ups, with attempt to estimate the role of various serum inflammatory markers in the diagnosis and assessment of ACS.Methods The study population include 40 patients with acute myocardial infarction (AMI), 40 patients with unstable angina pectoris (UAP), and 40 controls. Among the 80 patients, 60 patients attended a follow up 4 months later. Serum inflammatory markers including IL-1 β, sIL-2R, IL-6, TNF-α, and IFN-v were measured by enzyme linked immunosorbent assay.Results Serum IL- 1 β, sIL-2R, IL-6, TNF-α were significantly higher in AMI group or UAP group compared to the control group and became significantly lower 4 months later in the follow-up patients. Serum levels of IFN-v shows no significant difference between AMI group or UAP group and controls, also showing no significant change when measured in follow up patients. There was no correlation between serum creatine kinase-MB isoenzyme levels and serum inflammatory markers either in UAP or AMI group. Furthermore, when divided into two subgroups using Wagner's QRS scoring system in the AMI group, there is no difference of each serum inflammatory marker between ≤ 6 scores group and ＞ 6 scores group.Conclusion Serum levels of certain inflammatory markers may have some diagnostic value for ACS, and can be a useful marker reflecting disease stability.     

Possible Spread of adenovirus type 3 from poultry to humans ：indirect evidence from an outbreak in China

Objective:To explore the epidemiology and etiology for an outbreak of acute respiratory tract infection that occurred in one county of Jiangsu Province, China 2004. Methods: Only cases meeting the case definition were included in the study. We reviewed the medical records of the cases who were admitted to the local hospitals, interviewed cases by a standard questionnaire, and then described the epidemiotogic features and analyzed risk factors by means of a case-control study. We collected pharyngeal swab specimens and sent them to different laboratories for isolation and culture. The laboratory used different detection methods such as DIP, PCR, electron microscope examination and microneutralization assay, to identify and then type the positive specimens. Results:A total of 871 cases were reported during the period from April 18 to July 4,2004. The distribution of onset times presented two peaks, one in late May and another in middle June. The epidemic occurred mainly in the elementary and junior high schools in ten townships of one county, and the mean age of the cases was 12 years (range 7 months to 18 years). The course of the disease was acute, and was characterized by fever accompanied with sore throat and tonsillitis. The WBC count of cases was normal or elevated. The mean duration of illness was 5 days (range 2 to 12 days). No fatalities from illness were reported. A case-control study indicated that the possible risk factors were close contact with a case and/or poultry before onset and sharing of towels among members of the family. The typical CPE was observed through inoculating pharyngeal swab specimens into the HEP-2 cell cultures in different laboratories. An infection of adenovirus type 3 was verified by detecting positive specimens in different methods. Conclusion:This investigation demonstrated that the acute respiratory infection in cases was caused by adenovirus type 3. Cases occurred in over 70 schools in ten townships in 2004, and the route of transmission was possibly close contact with cases or droplet transmission.