OBJECTIVETo assess the effects of both TrkA and p75(NTR) on nerve growth factor (NGF)-induced differentiation of neuroblastoma cells.

METHODSRetroviral vectors were constructed to express the high affinity NGF receptor (TrkA) and low affinity NGF receptor (p75(NTR)). Neuroblastoma cell line IMR-32 was transfected by the vectors expressing either TrkA or p75(NTR) or both by using lipofectmine trade mark reagent separately or cotransfected at the same time. Southern blot, Northern blot, RT-PCR and flow cytometry were used to determine the success of the transfection. MTT technique was to monitor the cell proliferation. Colony formation in soft agar and tumor forming assay in nude mice were used to test the biological characteristics of the tumor cells. Terminal-deoxynucleotidytransferase-mediated dUTP-biotin nick end labeling (TUNEL) assay was used to test the apoptosis of the tumor cells.

RESULTSStable transformant cell lines expressing TrkA, p75(NTR) or both genes were established. Studies on these transformant cell lines have shown different NGF responses. The p75(NTR) transfection only resulted in the mild differentiation response, and transfection of TrkA gene caused remarkable neurite extension, up-regulation of neurofilament and decreased expression of N-myc oncogene after NGF treatment. The cotransfection of the two genes into this cell line resulted in the more rapid and more apparent morphological changes than single TrkA transfected cells after NGF treatment. The cotransfected cells underwent apoptosis after withdrawal of NGF.

CONCLUSIONSThe results indicate that coexpression of both low- and high-affinity NGF receptors are not only more efficient in restoration of NGF-induced differentiation pathway, but also be able to activate the pro-apoptotic activity of low-affinity NGF receptor and make the tumor cells become NGF-dependent and irreversibly differentiated.

Animals ; Apoptosis ; Cell Differentiation ; Genes, myc ; Humans ; Mice ; Mice, Nude ; Nerve Growth Factor ; pharmacology ; Neuroblastoma ; pathology ; Receptor, Nerve Growth Factor ; Receptor, trkA ; physiology ; Receptors, Nerve Growth Factor ; physiology ; Transfection ; Tumor Cells, Cultured

Objective: To summarize the characteristics of arrhythmia with the relevant factors affecting its prognosis in patients of apical hypertrophic cardiomyopathy (AHCM). Methods: A total 283 AHCM patients with echocardiography or cardiac magnetic resonance (CMR) conifrmed diagnosis in our hospital from 2005-01 to 2012-08 were summarized. The patients were divided into 2 groups: With arrhythmia group, n=103 and Without arrhythmia group,n=180. The endpoint event was followed-up by clinical and telephone visits in both groups and the relevant risk factors affecting AHCM prognosis were investigated by Cox regression analysis. Results: There were 269 patients ifnished the follow-up investigation, 98 in With arrhythmia group, 171 in Without arrhythmia group, and the death rate was 4.08% vs 1.17%, the occurrence of endpoint event was 18.37% vs 5.58%respectively. Cox regression analysis indicated that age (HR=23.051, 95% CI 1.08-1.068,P<0.005), left atrial diameter (HR=4.113, 95%CI 1.002-1.119,P=0.043) and NT-proBNP (HR= 18.653, 95% CI 3.433-26.650,P<0.005) were the independent risk factors affecting prognosis in AHCM patients. Conclusion: Arrhythmia is one of the common presentations of AHCM, it does not have much impact on survival, while it may cause ventricular ifbrillation and increase the occurrence of cardiovascular events.

Objective To investigate the therapeutic effect of the new K+ channel blocker 4-aminopyridine-3-methanol (4-AP-3-MeOH) on chronic spinal cord injury in rats.Methods 18 adult male Sprague-Dawley rats were randomly divided equally into 3 groups as follows:4-AP-3-MeOH treatment group (A),normal saline control group (B) and sham operation group (C).T10 segment of spinal cord compression injury was applied in group A and group B.4 weeks later,the rats in group A were daily treated by injecting 4-AP-3-MeOH 1 μmol (1000 μmol/L× 1 ml) into the veins of the tails for 4 weeks.While the same volume of saline was administrated into the group B for 4 weeks.Lamina of vertebra of T10 was cut without spinal cord injury in the sham-operation group.After modeling,the locomotor functional recovery was assessed by using Basso Beattie Bresnahan (BBB) scores and inclined plane (IP) tests,and all rats were periodical inspected by the somatosensory evoked potential(SEP) and motor evoked potential(MEP) post-operatively.Results BBB scores of group A started to increase gradually and were higher than those of group B from the 6th week,but the 2 groups at each time point in BBB scores were less than group C.Until 8 weeks after surgery,the inclined-plated angles of group A and B did not show significantly difference,but the both groups were significantly lower compared with group C.Electrophysiology study found that the amplitude of SEP and MEP in group A was higher than group B from the fourth to 8 weeks,but less than in group C.Histological examination showed that the spinal cord of rats in group C were morphologically intact with a clear demarcation between the grey and white matter.The gray matter structures of rats in group A and B were gone and a big cavity appears in the center of the spinal cord injury,with varying degrees of demyelination in the white around.In addition,statistically significant differences were found in the percentage of residual myelin at the injury epicenter between group A and group B.Conclusion With a persistent demyelination change and poor motor function in chronic spinal cord injury,daily administration of 4-AP-3-MeOH can improve the sensory and motor functions.

Objective:To improve the ability of identification and differential diagnosis of severe systemic lupus erythematosus (SLE).Methods:A severe SLE patient with lupus myocarditis, neuropsychiatric lupus, thrombotic microangiopathy (TMA) and other multiple system involvement was reported and discussed.Results:A young female patient developed albuminuria 5 months ago, edema of both lower limbs 3 months ago, change of consciousness 1 month ago and two convulsions attack 2 days ago. She experienced life threatening manifestations such as neuropsychiatric lupus, myocardial involvement of lupus, and TMA. During the course, her condition was generally improved after glucocorticoid pulse therapy and plasma exchange.Conclusion:Various complicated clinical manifestations related to SLE need to be recognized earlier and intervened as soon as possible.

Objective    To summarize the clinical experience of extracorporeal membrane oxygenation (ECMO) in adult patients with cardiac surgery, analyze the risk factors associated with the mortality and other severe complications and to discuss prevention methods of complications during ECMO treatment. Methods    The clinical data of 26 patients with cardiac surgery, who underwent ECMO because of cardiopulmonary insufficiency ect in Zhongshan Hospital, Fudan University from January 2012 to September 2017, were retrospectively analyzed. There were 19 males and 7 females aged 24–80 (58.0±13.9) years. Results    Twelve (42.3%) patients successfully weaned from ECMO and six (23.1%) were discharged from hospital. Among 26 patients, 24 received VA ECMO (veno-arterial ECMO), including 5 after heart transplantation, 9 after heart valve surgery, and 3 were successfully weaned from ECMO. Seven patients with valvular surgery underwent ECMO within 48 hours due to refractory low cardiac output syndrome (LCOS). Eight patients  underwent major angioplasty, 3 of whom were successfully weaned from ECMO. Four patients underwent coronary artery bypass grafting and other cardiac surgeries. Patients with VA ECMO were treated with femoral vein-femoral artery cannulation except for 2 patients undergoing femoral vein-radial artery cannulation after major angioplasty. Patients with VV ECMO (veno-venous ECMO) underwent femoral vein-jugular vein cannulation. After ECMO support, 10 patients with bleeding occurred, and 5 patients were successfully weaned from ECMO. All patients had transfusion therapy during the assist period, 7 patients had infection after ECMO support, 4 patients suffered severe distal limb ischemia. There was no significant difference in the lactic acid between the survival and the dead patients before and after ECMO support. However, the decline of serum lactic acid in the survivors was faster than that of the dead patients. The trend was the most significant within 6 h after the operation. Conclusion    ECMO is one of the significant treatments for LCOS and refractory hypoxemia after cardiac surgery. The type of cardiac surgery and the timing of catheter placement are key factors for the success of ECMO. The different ways of ECMO intubation, prevention and control of bleeding during ECMO, monitoring and management of internal environment and the strategies of anti-infection are all important for success of ECMO.