Assessment of three methods for removing massive air in a cardiopulmonary bypass circuit: simulation-based multi-discipline training in West China Hospital.

BACKGROUND AND OBJECTIVE: A multi-discipline cardiac and cardiopulmonary bypass (CPB) team simulation scenario was established to compare three different de-airing approaches dealing with massive air embolism in CPB, so as to formulate a standardized procedure to handle this adverse acute event more proficiently and ensure clinical safety. METHOD: A simulation-based clinical CPB massive air embolism scenario was developed by a cardiac and CPB team. Study Objects: Five licensed perfusionists and five CPB trainees were matched randomly into five pairs. Each pair would simulate the three different de-airing approaches separately as followed: (1) Conventional Method: arterial line filter (ALF) de-airing purge line and oxygenator self-recirculation bypass were used to de-air; (2) Arterial-Venous Loop (A-V Loop) Method: surgeons reconnected the arterial and venous lines to de-air by restoring the original priming A-V loop configuration; (3) Isolation of the ALF Method: this ensures de-bubbling of the CPB circuit, but bypasses the ALF function. Assessment Criteria: (1) Times to recovery (duration of the circulation suspension); (2) Subjective evaluation of skill and non-skill performances. RESULTS: As to times to recovery, the Conventional Method group took 290.6 s ± 36.2, the A-V Loop Method group took 196.8 s ± 52.0 and the Isolation of ALF group took 99.4 s ± 15.1. The statistical difference is significant among the three groups (p<0.01). The subjective evaluation of training performance indicates that this simulation-based training is effective in assessing both skill and non-skill abilities. CONCLUSION: CPB simulation-based training was effective in comparing de-airing strategies and can instruct perfusion practices how to optimize techniques. For well-trained, multi-discipline cardiac teams, the A-V Loop Method is highly efficient and reliable in managing CPB massive air embolism. For cardiac teams that do not have this sophisticated training, the Isolation of ALF Method should be their alternative option.

Effect of intralipid on myocardial injury during valve replacement surgery with concomitant radiofrequency ablation: A randomized controlled trial.

BACKGROUND: This study aimed to evaluate the effect of intralipid postconditioning (ILPC) on myocardial damage in patients undergoing valve replacement surgery with concomitant radiofrequency ablation (RFA) for atrial fibrillation (AF). METHODS: Randomized patient and assessor-blind controlled trial conducted in adult patients undergoing valve replacement surgery with concomitant RFA. Sixty-nine patients were randomly assigned to ILPC group (n = 34) or control group (n = 35): ILPC group received an intravenous infusion of 20% intralipid (2 mL/kg) just 10 minutes before aortic cross-unclamping, and control group received an equivalent volume of normal saline. Serum cardiac troponin-T (cTnT) and creatine kinase-MB (CK-MB) was measured before surgery and at 4, 12, 24, 48, and 72 hours after surgery. The primary endpoints were the 72-hour area under the curve (AUC) for cTnT and CK-MB. RESULTS: The total 72-hour AUC of cTnT (P = .33) and CK-MB (P = .52) were comparable between 2 groups. The left ventricle ejection fraction at discharge (P = .011) was higher in the ILPC group than that in the control group, while the AF recurrence did not differ significantly between 2 groups. CONCLUSIONS: There was no observed beneficial effect of ILPC on myocardial injury documented by the cardiac biomarkers in patients undergoing valve replacement surgery with concomitant RFA, and the effect of intralipid against myocardial I/R injury is undetectable within the background of massive biomarker release following ablation owing to localized myocardial necrosis. Besides, there are no other published data about the cardioprotective role of intralipid in patients undergoing this procedure and benefits of this protection need further studies to validate.

Hepatitis C virus core protein-induced miR-93-5p up-regulation inhibits interferon signaling pathway by targeting IFNAR1.

AIM: To investigate the mechanism by which hepatitis C virus (HCV) core protein-induced miR-93-5p up-regulation regulates the interferon (IFN) signaling pathway. METHODS: HCV-1b core protein was exogenously expressed in Huh7 cells using pcDNA3.1 (+) vector. The expression of miR-93-5p and interferon receptor 1 (IFNAR1) was measured using quantitative reverse transcription-polymerase chain reaction and Western blot. The protein expression and phosphorylation level of STAT1 were evaluated by Western blot. The overexpression and silencing of miR-93-5p and IFNAR1 were performed using miR-93-5p agomir and antagomir, and pcDNA3.1-IFNAR1 and IFNAR1 siRNA, respectively. Luciferase assay was used to identify whether IFNAR1 is a target of miR-93-5p. Cellular experiments were also conducted. RESULTS: Serum miR-93-5p level was increased in patients with HCV-1b infection and decreased to normal level after HCV-1b clearance, but persistently increased in those with pegylated interferon-α resistance, compared with healthy subjects. Serum miR-93-5p expression had an AUC value of 0.8359 in distinguishing patients with pegylated interferon-α resistance from those with pegylated interferon-α sensitivity. HCV-1b core protein increased miR-93-5p expression and induced inactivation of the IFN signaling pathway in Huh7 cells. Furthermore, IFNAR1 was identified as a direct target of miR-93-5p, and IFNAR1 restore could rescue miR-93-5p-reduced STAT1 phosphorylation, suggesting that the miR-93-5p-IFNAR1 axis regulates the IFN signaling pathway. CONCLUSION: HCV-1b core protein-induced miR-93-5p up-regulation inhibits the IFN signaling pathway by directly targeting IFNAR1, and the miR-93-5p-IFNAR1 axis regulates STAT1 phosphorylation. This axis may be a potential therapeutic target for HCV-1b infection.

Effect of intralipid postconditioning on myocardial injury in patients undergoing valve replacement surgery: a randomised controlled trial.

OBJECTIVE: This study was conducted to determine whether the administration of intralipid just before aortic cross-unclamping would reduce myocardial injury in patients undergoing valve replacement surgery. METHODS: Seventy-three adult patients, scheduled for elective aortic or mitral valve surgery without significant coronary stenosis (>70%), were randomly assigned to the intralipid postconditioning (ILPC) group (n=37) or control group (n=36): the ILPC group received an intravenous infusion of 20% intralipid (2 mL/kg) just 10 min before aortic cross-unclamping, and the control group received an equivalent volume of normal saline. Serum cardiac troponin T (cTnT) and creatine kinase-MB (CK-MB) was measured before surgery and at 4, 12, 24, 48 and 72 hours after surgery. The primary end points were the 72-hour area under the curve (AUC) for cTnT and CK-MB. RESULTS: No significant difference between the ILPC and control arm was observed, including the age, sex or number of aortic versus mitral valves or left ventricular ejection fraction at baseline. The total 72-hour AUC of cTnT and CK-MB in patients assigned to ILPC were significantly reduced by 32.3% (p=0.004) and 26.4% (p=0.0185) compared with control, respectively. None of the treated patients had abnormal blood lipid metabolism, abnormal renal or hepatic function or significant related complications. CONCLUSION: The protective effect of postischaemic administration of intralipid prior to aortic cross-unclamping on reperfusion injury was found when determined by biomarkers of myocardial injury but not by cardiac function or other clinical outcomes in patients undergoing valve replacement surgery. Hence, clinical benefits of this protection need larger clinical trials to confirm. TRIAL REGISTRATION NUMBER: ClinicalTrials.gov ID: ChiCTR-IOR-14005318.

[Long-term assessment of relapse and associated risk factors in chronic hepatitis C patients treated with interferon and ribavirin].

OBJECTIVE: To investigate viral relapse and the associated risk factors during a long-term follow-up study of chronic hepatitis C (CHC) patients who achieved end-of-treatment response (ETR) after interferon and ribavirin therapy. METHODS: This retrospective study was conducted on 146 CHC patients treated with a combination of ribavirin and pegylated (PEG) interferon-alpha (IFNa) (n=126) or conventional IFNa (n=20) for 24 (hepatitis C virus (HCV) non-genotype 1b) or 48 (HCV genotype 1b) weeks. The main outcome measure was serum HCV RNA load. The risk factors analyzed included age, sex, HCV genotype, baseline HCV RNA load, and IFN type. RESULTS: The mean follow-up time for all patients was 33.45+/-16.41 months (range: 12-85 months). The cumulative relapse rate during follow-up was 14.80%. The relapse rate within six months (8.90%) was significantly higher than other periods during two years of follow-up, and no relapse occurred after 30 months. Of all relapsers (n=20), 65% occurred within six months, followed by 35% within 7-24 months after antiviral therapy. The relapse rates in patients with HCV genotype 1b and non-1b were not significantly different (20.37% vs. 12.12%, X2 =1.517, P=0.315). The mean baseline HCV RNA load was significantly higher in the relapsers than that in the non-relapsers (t=0.915, P=0.362). Relapse rates were similar in patients treated with PEG-IFNa-2b, PEG-IFNa-2a and IFNa (12.12% vs. 13.97% vs. 15.00%, respectively; X2=0.104, p=0.949). The mean age of relapsers was significantly higher than that of non-relapsers (P less than 0.005). CONCLUSION: The maximum probability of relapse for CHC patients exists within six months from when ETR is achieved by interferon and ribavirin therapy. A lower risk for relapse persists past this period. Thus, ETR CHC patients, especially older patients, should be carefully monitored during the two years after cessation of antiviral therapy. Standard antiviral therapy based on HCV genotype eliminates the influence of viral factors on treatment-response.

[The velocity of HCV subtype 6a transmission in southwest China].

OBJECTIVE: To estimate the velocity of HCV subtype 6a transmission in Southwest China. METHODS: The HCV CE1 region from 61 patients infected with HCV genotype 6 were amplificated by RT-PCR and sequenced. The subtypes were identified, and the period of HCV 6a strains originated in southwest china was estimated by using molecular clock phylogenetic analysis. The velocity of HCV subtype 6a transmission in southwest China was estimated by BEAST v1.6.1 and Tracer v1.5 software theoretically. RESULTS: Most of HCV 6a strains distributed in Southwest China origine around the year 1968 and at last 4 epidemic strains existed. The earlier origine strains could be isolated both in intravenous drug users (IDU) and non-IDU patients. After 1997, the HCV 6a strains transmission in southwest China accelerated and the trend intensified in 2007. CONCLUSION: HCV 6a strains spread fastly both in IDU and non-IDU patients, which might be the main HCV subtype distributed in Southwest China in the future.

[Positive selection analysis of hepatitis C virus genotype 1b envelope 2 gene and its significance during natural chronic infection].

AIM: To elucidate adaptive evolution patterns and perform a positive selection analysis of hepatitis C virus(HCV) genotype 1b envelope 2 gene(E2) during natural chronic infection by a longitudinal study. METHODS: HCV E2 quasispecies profiles were derived from partially sequenced domains of 6 000 bp recombinant clones. Phylogenetic trees for HCV E2 gene were constructed by MEGA software and the specific codons undergoing diversifying positive selection were identified by FEL method. RESULTS: HCV phylogenies, coupled with the number and distribution of selected sites were differed markedly between patients. HCV quasispecies complexity during chronic infection was not associated with the evolutionary time and the dominant viriant alternation of HCV quasispecies may occur after more than six months apart. Five sites under positive selection were identified within the ectodomain of the E2 protein. CONCLUSION: A series of serum specimens for studies based on dominant viriant of HCV dynamic quasispecies is recommended to be collected at every six months. Several individual sites of HCV E2 gene are under a strong host immune pressure, position aa384, aa399 and aa410 may be involved in escape from neutralizing antibodies, while position aa475, aa522 may correlate to modulate the virus-receptor interaction which result in evading immunity.

[Analysis of the correlation between the pre-S1 antigen, pre-S2 antigen and DNA of hepatitis B virus in the serum of chronic hepatitis B patients undergoing nucleoside analogue therapy.].

OBJECTIVE: To investigate the dynamic correlation between pre-S1 antigen, pre-S2 antigen and HBV DNA in the serum of chronic hepatitis B (CHB) patients undergoing nucleoside analogue therapy. METHODS: 12 CHB patients with transient virological response after lamivudine treatment, and 20 patients treated with adefovir for 5 years were recruited in this study. Serum samples were collected at four time points when HBV DNA fluctuated sharply during lamivudine treatment, and at 0, 8, 12, 28, 52, 104, 156, 208, 260 weeks following adefovir treatment. HBV DNA was quantified by real-time PCR, pre-S1 and pre-S2 antigens were detected by ELISA. RESULTS: The titers of pre-S1 and pre-S2 antigens were not correlated with the HBV DNA level in the serum of lamivudine treated patients. Only in one case of the adfovir treated patients, the decrease of pre-S1 and pre-S2 antigens was in parallel with the decrease of HBV DNA. Linear regression analysis indicated that neither pre-S1 antigen nor pre-S2 antigen was correlated with HBV DNA in the serum of lamivudine or adfovir treated patients (P more than 0.05). CONCLUSION: Our results indicate that the titers of pre-S1 and pre-S2 antigens are not correlated with the serum HBV DNA in CHB patients undergoing nucleoside analogue therapy. Neither pre-S1 nor pre-S2 is a good predictor for the outcome of nucleoside analogue treatment.

[The primary comparative analysis between the host genetic factors and their relationships with clinical phenotype of HBV infected twins].

OBJECTIVE: The primary comparative analysis between the host genetic factors and their relationships with clinical phenotype of 20 pairs of HBV infected and high risk twins. METHODS: Zygosity of twins was diagnosed by STR microsatellite polymorphism analysis. To identify the serological model and exclude the evidence of coinfection with other virus, we detected HAV, HBV, HCV, HDV, HEV serological markers by electrochemiluminescence method. HBV DNA level was detected by Lightcycler Fluorescent Quantitative system and Liver function (ALT, AST, TBil) was detected by HITACHI7250 Biochemistry Detection System. The data was analysis by Fisher's exact test to comparatively analyze among the monozygotic twins (MZ), dizygotic twins (DZ) and control groups. RESULTS: The significant difference was found in the concordance rate of disease, concordance of clinical phenotype and serological patterns of HBV infection between the MZ and DZ twins (P < 0.05), it was also found between MZ and control groups (P < 0.05), but not between DZ and control groups (P > 0.05). No significant difference in the concordance of other HBV infection markers was observed (P > 0.05). Concordance of clinical phenotype may be related to patients' age and antivirus therapy. Injection with the HBIg and initiative vaccination right after birth can prevent twins with high risk to infection to be victims. CONCLUSION: The significant difference was found in the concordance rate, concordance of clinical phenotype and serological patterns between MZ and control groups, it was also found between MZ and DZ groups, which is correspond to the opinion of the high concordance of MZ and indicated the host genetic factors may play role in influencing the clinical phenotype, while other factors such as the vaccination may have an effect on the clinical phenotype in some extent.