[Treatment efficiency evaluation of left cardiac sympathetic denervation for patients with inherited arrhythmia by exercise-stress test].

Objective: To evaluate the efficiency of left cardiac sympathetic denervation (LCSD) in inherited arrhythmia patients with adrenergic activity-induced malignant ventricular arrhythmia, and observe exercise-stress test features before and after LCSD. Methods: This retrospective observational study included catecholaminergic polymorphic ventricular tachycardia(CPVT) and long QT syndromes(LQTS) patients who underwent video-assisted LCSD at Beijing Tsinghua Changgung Hospital and Peking University People's Hospital from September 2006 to May 2020. The indications for LCSD surgery were intolerant or refractory to beta-blocker medication. Clinical and exercise-stress tests data of included patients were collected before and 1 month after LCSD. Heart rate, exercise tolerance, atrial and ventricular arrhythmia, QTc interval and predictors for sudden cardiac death were analyzed. Patents were regularly followed up at 1, 3, 6, and 12 months after LCSD and then once every year thereafter. Cardiac events and medication adjustment records were collected. Results: Five patients (2 CPVT, 1 LQT1, and 2 LQT2)were included in the study. All patients experienced syncope as first symptom at the median age of 12(10, 16)years, and underwent LCSD at the median age of 21(16, 26)years, Baseline heart rate was similar before and after LCSD ((65.6±6.5) beats/min vs. (68.0±11.1) beats/min, P=0.57); while maximum workload tended to be lower after LCSD ((12.1±2.8) metabolic equivalents (METS) before surgery vs. (10.5±2.4) METS after surgery, P=0.07). Incidence of atrial and ventricular arrhythmia were significantly reduced post LCSD, and the ventricular arrhythmia score was decreased after LCSD in CPVT patients (4 points before LCSD vs. 3 points after LCSD in case 1;5 points before LCSD vs. 3 points after LCSD in case 2). QTc interval was shortened significantly in three LQTs patients (QTc interval at baseline heart rate: (546.6±72.3) ms before surgery vs. (493±61.1) ms after LCSD, P=0.047; QTc interval at maximal exercise heart rate: (516.3±73.7) ms before surgery vs. (486.7±64.2)ms after LCSD, P=0.035). Additionally, sudden cardiac death risk indicator ΔHRR1 (heart rate decreasing value within the first 1 min during recovery phase) decreased from (51.5±21.1) beats/min before surgery to (32.0±13.9) beats/min after surgery (P=0.035). During a median follow-up of 1(1, 4) year, all five patients were on low dosage of propranolol (37.0±21.7) mg/d. Cardiac events free survival was achieved in four out of 5 patients (80%) after sympathectomy, while 1 case suffered from sudden cardiac death after emotional stress. Conclusion: LCSD surgery can be safely and effectively performed in most hereditary arrhythmia patients with adrenergic activity-induced life-threatening cardiac events. Exercise stress test results show that LCSD could reduce malignant arrhythmias and improve sudden cardiac death risk indicators without decreasing heart rate.

Epigenomics alternations and dynamic transcriptional changes in responses to 5-fluorouracil stimulation reveal mechanisms of acquired drug resistance of colorectal cancer cells.

A drug-induced resistant cancer cell is different from its parent cell in transcriptional response to drug treatment. The distinct transcriptional response pattern of a drug-induced resistant cancer cell to drug treatment might be introduced by acquired DNA methylation aberration in the cell exposing to sustained drug stimulation. In this study, we performed both transcriptional and DNA methylation profiles of the HCT-8 wild-type cells (HCT-8/WT) for human colorectal cancer (CRC) and the 5-fluorouracil (5-FU)-induced resistant cells (HCT-8/5-FU) after treatment with 5-FU for 0, 24 and 48 h. Integrated analysis of transcriptional and DNA methylation profiles showed that genes with promoter hypermethylation and concordant expression silencing in the HCT-8/5-FU cells are mainly involved in pathways of pyrimidine metabolism and drug metabolism-cytochrome P450. Transcriptional analysis confirmed that genes with transcriptional differences between a drug-induced resistant cell and its parent cell after drug treatment for a certain time, rather than their primary transcriptional differences, are more likely to be involved in drug resistance. Specifically, transcriptional differences between the drug-induced resistant cells and parental cells after drug treatment for 24 h were significantly consistent with the differentially expressed genes (termed as CRG5-FU) between the tissues of nonresponders and responders of CRCs to 5-FU-based therapy and the consistence increased after drug treatment for 48 h (binomial test, P-value=1.88E-06). This study reveals a major epigenetic mechanism inducing the HCT-8/WT cells to acquire resistance to 5-FU and suggests an appropriate time interval (24-48 h) of 5-FU exposure for identifying clinically relevant drug resistance signatures from drug-induced resistant cell models.

Virulence and potential pathogenicity of coccoid Helicobacter pylori induced by antibiotics.

AIM: To explore the virulence and the potential pathogenicity of coccoid Helicobacter pylori (H. pylori) transformed from spiral form by exposure to antibiotic. METHODS: Three strains of H. pylori, isolated from gastric biopsy specimens of confirmed peptic ulcer, were converted from spiral into coccoid from by exposure to metronidazole. Both spiral and coccoid form of H. pylori were tested for the urease activity, the adherence to Hep-2 cells and the vacuolating cytotoxicity to Hela cells, and the differences of the protein were analysed by SDS-PAGE and Western blot. The mutation of the genes including ureA, ureB,hpaA, vacA and cagA, related with virulence, was detected by means of PCR and PCR-SSCP. RESULTS: In the coccoid H. pylori,the urease activity, the adherence to Hep-2 cells and the vacuolating cytotoxicity to Hela cells all decreased. In strain F44, the rate and index of adherence reduced from 70.0% +/- 5.3% to 33% +/- 5.1% and from 2.6 +/- 0.4 to 0.96 +/- 0.3 (P < 0.01), respectively. The invasion of coccoid H. pylori into Hep-2 cell could be seen under electronmicroscope. SDS-PAGE showed that the content of the protein with the molecular weight over Mr 74000 decreased, and the hybriditional signal in band M(r) 125000 weakened, while the band M(r)110000 and M(r)63000 strengthened in coccoid H.pylori as shown in Western blot. The results of PCR were all positive, and PCR-SSCP indicated that there may exist the point mutation in gene hpaA or vacA. CONCLUSION: The virulence and the proteins with molecular weight over M(r)74000 in coccoid H.pylori decrease, but no deletion exists in amplification fragments from ureA, ureB, hpaA, vacA and cagA genes, suggesting that coccoid H.pylori may have potential pathogenicity.