[Efficacy of alcohol septal ablation in mildly symptomatic or severely symptomatic patients with hypertrophic obstructive cardiomyopathy]

Objective: To compare the prognosis of mildly or severely symptomatic patients with obstructive hypertrophic cardiomyopathy (OHCM) who underwent alcohol septal ablation (ASA). Methods: This retrospective study cohort consisted of patients with OHCM who received ASA treatment in Beijing Anzhen Hospital, Capital Medical University from March 2001 to August 2021. These patients were divided into mildly and severely symptomatic groups according to the severity of clinical symptoms. Long-term follow-up was conducted, and the following data were collected: duration of follow-up, postoperatire treatment, New York Heart Association (NYHA) classification, arrhythmia events and pacemaker implantation, echocardiographic parameters, and cause of death. Overall survival and survival free from OHCM-related death were observed, and the improvement of clinical symptoms and resting left ventricular outflow tract gradient (LVOTG) and the incidence of new-onset atrial fibrillation were evaluated. The Kaplan-Meier method and log-rank test were used to determine and compare the cumulative survival rates of the different groups. Cox regression analysis models were used to determine predictors of clinical events. Results: A total of 189 OHCM patients were included in this study, including 68 in the mildly symptomatic group and 121 in the severely symptomatic group. The median follow-up of the study was 6.0 (2.7, 10.6) years. There was no statistical difference in overall survival between the mildly symptomatic group (5-year and 10-year overall survival were 97.0% and 94.4%, respectively) and the severely symptomatic group (5-year and 10-year overall survival were 94.2% and 83.9%, respectively, P=0.405); there was also no statistical difference in survival free from OHCM-related death between the mildly symptomatic group (5-year and 10-year survival free from HCM-related death were 97.0% and 94.4%, respectively) and the severely symptomatic group (5-year and 10-year survival free from HCM-related death were 95.2% and 92.6%, respectively, P=0.846). In the mildly symptomatic group, NYHA classification was improved after ASA (P<0.001), among which 37 patients (54.4%) were in NYHA class Ⅰ, and the resting left ventricular outflow tract gradient (LVOTG) decreased from 67.6 (42.7, 90.1) mmHg (1 mmHg=0.133 kPa) to 24.4 (11.7, 35.6) mmHg (P<0.001). In severely symptomatic group, NYHA classification was also improved post ASA (P<0.001), among which 96 patients (79.3%) improved by at least one NYHA classification, and the resting LVOTG decreased from 69.6 (38.4, 96.1) mmHg to 19.0 (10.6, 39.8) mmHg (P<0.001). The incidence of new-onset atrial fibrillation was similar between the mildly and severely symptomatic groups (10.2% vs. 13.3%, P=0.565). Cox multivariate regression analysis showed that age was an independent predictor of all-cause mortality in OHCM patients post ASA (HR=1.068, 95%CI 1.002-1.139, P=0.042). Conclusions: Among patients with OHCM treated with ASA, overall survival and survival free from HCM-related death were similar between mildly symptomatic group and severely symptomatic group. ASA therapy can effectively relieve resting LVOTG and improve clinical symptoms in mildly or severely symptomatic patients with OHCM. Age was an independent predictor of all-cause mortality in OHCM patients post ASA.

[Therapeutic effects of alcohol septal ablation in mildly symptomatic patients with hypertrophic obstructive cardiomyopathy]

Objective: To observe the therapeutic effects of alcohol septal ablation (ASA) in mildly symptomatic patients (NYHA class Ⅱ) with hypertrophic obstructive cardiomyopathy(HOCM). Methods: This retrospective study included 150 mildly symptomatic patients with HOCM hospitalized in Beijing Anzhen Hospital affiliated to Capital Medical University from March 2001 to December 2017, consisting of medical therapy group (n=102) and ASA group (n=48). Baseline clinical data were collected, patients were followed up to a mean of 6.0 (3.5, 8.1) years. Overall and HCM-related mortality events (including chronic heart failure, atrial fibrillation related stroke, sudden cardiac death) were observed in the two groups. Moreover, the improvement of NYHA function classification and left ventricular outflow tract gradient (LVOTG) were also evaluated. Survival analysis was performed by Kaplan-Meier method. Results: Age of this cohort was (52.9±14.5)years, 92 cases(61.3%) were male. In the follow-up, LVOTG was reduced from (85.8±35.4)mmHg (1 mmHg=0.133 kPa) to (27.7±19.8)mmHg (P<0.001) in the ASA group, and from (66.3±35.0)mmHg to (56.5±27.7)mmHg in medical therapy group(P<0.01). At the last clinical follow-up, there were 32 patients (66.7%) whose LVOTG were<30 mmHg, septal thickness decreased from (20.3±3.8)mm to (16.1±3.4)mm (P<0.001), NYHA classification was also remarkably improved (P<0.001). New-onset atrial fibrillation tended to be lower in the ASA group compared to medical therapy group (9.3%(4/43) vs. 20.8%(20/96),P=0.096). Eleven patients (10.8%) in the medical therapy group and 2 patients (4.2%) in the ASA group died during the follow-up. One patient received pacemaker during the peri-procedural period, 1 patient was implanted with two-chamber pacemaker due to Ⅲ° atrioventricular block at 10 years after operation in the ASA group. Survival free of all-cause mortality of ASA group at 5 and 10 years was 97.9% and 97.9%, respectively, which was comparable to the medical therapy group (P=0.231). Survival free of HCM-related mortality was similar between the two groups (P=0.397). Conclusions: Compared with medical therapy in mildly symptomatic patients with HOCM, long-term survival rate is similar after ASA. Meanwhile, ASA can remarkably reduce LVOTG and improve the clinical status of the patients. Therefore, ASA may be used as an alternative therapy for mildly symptomatic HOCM patients.

[Drug-resistant gene polymorphisms in Plasmodium falciparum isolated from Bioko Island, Equatorial Guinea in 2018 and 2019]

OBJECTIVE

To investigate the genetic polymorphisms of Plasmodium falciparum multidrug resistance protein 1 (PfMDR1), chloroquine resistance transporter (PfCRT) and Kelch 13 (PfK13) genes in Bioko Island, Equatorial Guinea, so as to provide insights into the development of the malaria control strategy in local areas.

METHODS

A total of 85 peripheral blood samples were collected from patients with Plasmodium falciparum infections in Bioko Island, Equatorial Guinea in 2018 and 2019, and genomic DNA was extracted. The PfMDR1, PfCRT and PfK13 genes were amplified using a nested PCR assay. The amplification products were sequenced, and the gene sequences were aligned.

RESULTS

There were no mutations associated with artemisinin resistance in PfK13 gene in Bioko Island, Equatorial Guinea, while drug-resistant mutations were detected in PfMDR1 and PfCRT genes, and the proportions of PfMDR1_N86Y, PfMDR1_Y184F and PfCRT_K76T mutations were 35.29% (30/85), 72.94% (62/85) and 24.71% (21/85), respectively.

CONCLUSIONS

There are mutations in PfMDR1, PfCRT and PfK13 genes in P. falciparum isolates from Bioko Island, Equatorial Guinea.

[Long-term outcomes and risk factors of ostial/shaft lesions in unprotected left main coronary artery after percutaneous coronary intervention]

Objective: To evaluate the long-term clinical outcomes after percutaneous coronary intervention (PCI) with drug-eluting stents (DES) for ostial/shaft lesions in patients with unprotected left main coronary artery (ULMCA). Method: A total of 271 patients with isolated ostial/midshaft lesions in unprotected left main coronary artery who received drug-eluting stents (DES) implantation between January 2003 and July 2009 in Beijing An Zhen Hospital were consecutively enrolled . The endpoints of the study were all-cause death, repeat revascularization, myocardial infarction (MI) and stroke. Cox regression was carried out to analyze the all-cause mortality. Meanwhile, multivariate logistic regression analysis was performed to determine the independent risk factors of all-cause death. Results: The mean age of the patients was (62±10) years, and 201 of them (74.2%) were male. The median follow-up was 12.5 years (interquartile range: 10.1-14.5 years). During the follow-up, 46 patients (17.0%) died, of whom 20 (7.4%) died of a cardiovascular cause. A total of 38 (14.0%) cases suffered a MI, and 15 (5.5%) cases suffered a stroke. Repeat revascularization was performed in 63 (23.2%) cases. Multivariate logistic regression analysis showed that age (HR=1.041, 95%CI: 1.003-1.081, P=0.033), creatinine (HR=1.028, 95%CI:1.014-1.042, P<0.001) and diabetes mellitus (HR=1.924,95%CI: 1.053-3.514, P=0.033) were independent risk factors of all-cause death, whereas left ventricular ejection fraction (LVEF) (HR=0.972, 95%CI:0.953-0.992, P=0.007) was a protective factor. Conclusions: During a median follow-up of 12.5 years, the prognosis of PCI for left main ostium/shaft lesion was good. Age, creatinine and diabetes mellitus are independent risk factors of all-cause death.

First-Principles Study of Anharmonic Lattice Dynamics in Low Thermal Conductivity AgCrSe_{2}: Evidence for a Large Resonant Four-Phonon Scattering

We report a study of the anharmonic lattice dynamics in low lattice thermal conductivity (κ_{l}) material AgCrSe_{2} by many-body perturbation theory. We demonstrate surprisingly giant four-phonon scattering exclusive for the heat-carrying transverse acoustic phonons due to large quartic anharmonicity and nondispersive phonon band structure, which lead to four-phonon Fermi resonance and breaks the classical τ^{-1}∼ω^{m}T^{n} relation for phonon-phonon interactions. This strong resonant scattering extends over the Brillouin zone and substantially suppresses the thermal transport, even down to a low temperature of 100 K. The present results provide fundamental insights into the four-phonon resonant dynamics in the low-κ_{l} system with flat phonon dispersions, i.e., cuprous halides and skutterudites.

[Long-term prognosis of drug eluting stents implantation in elderly patients with unprotected left main coronary artery disease]

Objective: To analyze the clinical characteristics and long-term prognosis of implantation of drug-eluting stents (DES) for elderly patients with unprotected left main artery (ULM) disease. Methods: A total of 414 patients (327 males and 87 females) who underwent DES implantation were enrolled in the Department of Cardiology, Beijing Anzhen Hospital from January 2005 to March 2010, with a mean age of (61.5±10.7) years old. The patients were divided into two groups according to age: 300 cases in the group of age <70 years old, and 114 cases in the group of age ≥70 years old. The clinical characteristics and long-term prognosis of two groups were compared. Results: In the group of age ≥ 70 years old, the proportion of female was higher (31.6% vs 17.0%, P=0.001) and the incidence of chronic total occlusion (CTO) (P=0.020), hypertension (P=0.018) and cerebrovascular disease (P=0.013) were higher than those in the group of <70 years old. All-cause mortality and cardiac mortality were also higher than those in the group of <70 years old (P=0.025, P=0.013). The follow-up period was (21.4±9.6) months. After adjusting for multiple clinical factors, there were no statistical differences of incidence of the total major adverse cardiac and cerebral events (MACCE), myocardial infarction, cerebrovascular events, and revascularization recurrence between the two groups. But all-cause mortality (HR=3.790, 95%CI: 1.271-11.298, P=0.017) and cardiac mortality (HR=17.424, 95%CI: 2.440-124.410, P=0.004) in the group of age ≥70 years old were still remarkably higher than those in the group of <70 years old. Conclusions: Age is an independent risk factor for increased mortality after DES stent implantation in ULM disease. DES stent implantation in age ≥70 years old patients with ULM disease is considered feasible, but it needs to be treated with caution.

[Long-term outcome comparison of ostial/shaft lesions in unprotected left main coronary artery treated by PCI or CABG]

Objective: To evaluate long-term clinical outcomes of consecutive patients treated with coronary artery bypass grafting (CABG) and percutaneous coronary intervention(PCI) with drug-eluting stents(DES) for ostial/shaft lesions in unprotected left main coronary artery(ULMCA). Method: A total of 259 patients with isolated ostial/midshaft lesions in unprotected left main coronary artery were enrolled consecutively who received DES implantation or underwent CABG between January 2003 and July 2009 in Beijing Anzhen Hospital. The endpoints of the study were death, repeat revascularization, myocardial infarction (MI) and stroke. Time to the primary endpoint was evaluated according to the Kaplan-Meier method, and the log-rank test was applied to compare the incidence of the endpoint. Adjusted risks for adverse outcomes were compared by multivariate Cox proportional hazard regression analyses. Results: A total of 259 patients were included, including 149 in PCI group and 110 in CABG group. And 193(74.5%) cases were males.The age was (61.4±9.8) years old. The median follow-up was 10.1 years (interquartile range 8.3 to 11.2 years) in the overall patients. There were no significant difference for the incidence of death [37.0% vs. 43.1% ，P=0.143] , MI [34.0% vs. 19.4% ，P=0.866], stroke [6.4% vs. 11.7% ， P=0.732], repeart revascularization [33.6% vs. 39.9% ，P=0.522] between PCI group and CABG group before multivariate adjusting，according to the incidence calculated with Kaplan-Meier. After adjusting covariates such as age, left ventricular ejection fraction（LVEF） and serum creatine with multivariate Cox hazard regression model, there was still no significant difference between the two groups. Conclusions: PCI with DES is as effective and safe as CABG in patients with left main ostium/shaft lesion during a median follow-up of 10.1 years.

Liquid-like thermal conduction in intercalated layered crystalline solids

As a generic property, all substances transfer heat through microscopic collisions of constituent particles ¹ . A solid conducts heat through both transverse and longitudinal acoustic phonons, but a liquid employs only longitudinal vibrations^2,3. As a result, a solid is usually thermally more conductive than a liquid. In canonical viewpoints, such a difference also serves as the dynamic signature distinguishing a solid from a liquid. Here, we report liquid-like thermal conduction observed in the crystalline AgCrSe₂. The transverse acoustic phonons are completely suppressed by the ultrafast dynamic disorder while the longitudinal acoustic phonons are strongly scattered but survive, and are thus responsible for the intrinsically ultralow thermal conductivity. This scenario is applicable to a wide variety of layered compounds with heavy intercalants in the van der Waals gaps, manifesting a broad implication on suppressing thermal conduction. These microscopic insights might reshape the fundamental understanding on thermal transport properties of matter and open up a general opportunity to optimize performances of thermoelectrics.

[Predictive value of serial platelet function testing on outcome in patients undergoing complex percutaneous coronary intervention]

Objective: To observe the predictive value of serial platelet function testing (PFT) on outcome in patients undergoing complex percutaneous coronary intervention (PCI). Methods: Six hundred and two consecutive patients undergoing complex PCI in Anzhen hospital were enrolled during October 2011 to June 2012.Adenosine diphosphate(ADP)-induced platelet aggregation was measured by light transmission aggregometry on the first, sixth and twelfth month after PCI and the mean value was calculated.The cut-off value of high on-treatment platelet reactivity (HTPR) was defined as 40%.The primary endpoint was major adverse cardiovascular and cerebral event (MACCE). Clinical outcomes were analyzed by the Kaplan-Meier method and differences were compared using the log-rank test.Multivariate analyses by Cox proportion hazards regression were applied to identify variables independently associated with the adverse outcomes. Results: Five hundred and eighty-five patients (HTPR, n=285; non-HTPR, n=280) finished the follow-up ((28.47±7.45) months). A total of 33 cases of MACCE were observed during the follow-up, among which 29 cases(8.42%) were in HTPR group and 9 cases (3.21%) in the non-HTPR group.Kaplan-Meier analysis suggested that HTPR was associated with an increased incidence of MACCE (log-rank test, P=0.01). The Cox multivariate analysis indicated that HTPR was an independent risk factor of MACCE (HR=2.69, 95%CI 1.23-5.85, P=0.01) in patients undergoing complex PCI.Incidence of MACCE was similar between HTRP patients receiving standard dual antiplatelet therapy (DAPT) or prolonged DAPT (>12 months). Conclusion: Serial PFT could predict the long-term prognosis of patients underwent complex PCI.

[Value of early-stage cerebral oxygen utilization coefficient in predicting delayed encephalopathy after acute carbon monoxide poisoning]

Objective: To investigate the dynamic change in cerebral oxygen utilization coefficient (O(2)UCc) in the early stage of acute severe carbon monoxide poisoning (ASCMP) and its value in predicting delayed encephalopathy after acute carbon monoxide poisoning (DEACMP) . Methods: A prospective observational study was conducted for patients with ASCMP who were admitted to our hospital from November 2013 to March 2016, and their baseline features and physiological parameters were recorded. Observation ended at two months after acute poisoning; according to the presence or absence of DEACMP, the patients were divided into DEACMP group with 21 patients and non-DEACMP group with 64 patients. The change in O(2)UCc was monitored on admission and at 6, 24, 48, and 72 hours. Spearman correlation was used to investigate the correlation between O(2)UCc and Acute Physiology and Chronic Health Evaluation II (APACHE II) score, and the receiver operating characteristic (ROC) curve was used to evaluate the accuracy of O(2)UCc in predicting DEACMP. Results: Both groups had a significant increase in O(2)UCc on admission, and the DEACMP group had a significantly greater increase than the non-DEACMP group (52.57%±9.30% vs 41.46±%6.37%, P<0.05) . Then both groups tended to have a reduction in O(2)UCc, and the DEACMP group had a significantly higher O(2)UCc than the non-DEACMP group at 6, 24, and 48 hours (47.40%±7.92%, 39.38%±8.01%, and 32.29%±6.31% vs 34.51%±7.89%, 28.79%±5.4%, and 27.72%±5.46%, P<0.05) . On admission and at 6, 24, and 48 hours, O2UCc was positively correlated with APACHE II score (r=0.304, 0.398, 0.426, and 0.300, P=0.005, 0.000, 0.000, and 0.005) . The ROC curve showed that O(2)UCc had a value in predicting DEACMP on admission and at 6, 24, and 48 hours, and 6-hour O2UCc had the highest predictive value with an area under the ROC curve of 0.870 (95% confidence interval 0.794-0.947, P<0.05) . Conclusion: The dynamic change in O(2)UCc has a reference value in early identification of DEACMP, and O(2)UCc can be used as an important reference index for predicting DEACMP.

[Ventilator-associated pneumonia among premature infants <34 weeks' gestational age in neonatal intensive care unit in China: a multicenter study]

Objective: To investigate the incidence and pathogen distribution of ventilator-associated pneumonia (VAP) among preterm infants admitted to level Ⅲ neonatal intensive care units (NICU) in China. Method: A prospective study was conducted in 25 level Ⅲ NICU, enrolling all preterm infants <34 weeks gestational age admitted to the participating NICU within the first 7 days of life from May 2015 to April 2016. Chi-square test, t test and Mann-Whitney U test were used for statistical analysis. Result: A total of 7 918 patients were enrolled, within whom 4 623(58.4%) were males. The birth weight was (1 639±415) g and the gestational age was (31.4±2.0) weeks; 4 654(58.8%) infants required non-invasive mechanical ventilation and 2 154(27.2%) required intubation. Of all the mechanically ventilated patients, VAP occurred in 95 patients. The overall VAP rate was 7.0 episodes per 1 000 ventilator days, varying from 0 to 34.4 episodes per 1 000 ventilator days in different centers. The incidence of VAP was 9.6 and 6.0 per 1 000 ventilator days in children's hospitals and maternity-infant hospitals respectively, without significant differences (t=1.002, P=0.327). Gram-negative bacilli (76 strains, 91.6%) were the primary VAP microorganisms, mainly Acinetobacter baumannii (24 strains, 28.9%), Klebsiella pneumonia (23 strains, 27.7%), and Pseudomonas aeruginosa (10 strains, 12.0%). Conclusion: The incidence of VAP in China is similar to that in developed counties, with substantial variability in different NICU settings. More efforts are needed to monitor and evaluate the preventable factors associated with VAP and conduct interventions that could effectively reduce the occurrence of VAP.

[Comparison on the long-term outcomes post percutaneous coronary intervention or coronary artery bypass grafting for bifurcation lesions in unprotected left main coronary artery]

Objective: To compare the long-term clinical outcomes of consecutive patients treated with coronary artery bypass grafting (CABG) or percutaneous coronary intervention(PCI) with drug-eluting stents (DES) for bifurcation lesions in unprotected left main coronary artery (ULMCA). Methods: A total of 663 consecutively patients with unprotected left main bifurcation disease (defined as stenosis≥50%) who received either drug-eluting stents (DES) implantation (n=316) or underwent CABG (n=347) between January 2003 and July 2009 in Beijing Anzhen Hospital were enrolled retrospectively in this study.The endpoints of the study were death, repeat revascularization, myocardial infarction (MI), stroke, the composite of cardiac death, MI or stroke and MACCE (major adverse cardiac and cerebrovascular events, the composite of cardiac death, MI, stroke or repeat revascularization). To reduce the bias between two compared groups , our study applid propensity score matching by logistic regression.Cumulative survival rate was calculated by Kaplan-Meier method.Multiple regression analyses, hazard ratio(HR) and 95%CI were tested by Cox proportional hazard models with the CABG group as the reference category. Results: The median follow-up was 7.2 years (interquartile range 5.1 to 8.3 years) in the overall patients.Unadjusted analysis showed that MACCE rate (PCI 44.5% vs. CABG 45.7%, P=0.036), the rate of repeat revascularization (PCI 33.7% vs. CABG 19.5%, P<0.001), the composite rate of serious outcomes (cardiac death, MI or stroke) (PCI 20.4% vs. CABG 34.3%, P=0.032), stroke rate (PCI 3.7% vs. CABG 23.5%, P<0.001) were significantly different for patients undergoing PCI or CABG. Death rate (PCI 13.0% vs. CABG 18.9%, P=0.12) and MI rate (PCI 11.3% vs. CABG 6.1%, P=0.108) were similar between PCI and CABG group.After adjusting covariates with multivariate Cox hazard regression model, there was no significant difference in rates of death (P=0.286), MI(P=0.165) and the composite rate of serious outcomes (cardiac death, MI or stroke) (P=0.305) between the two groups. Patients in PCI group suffered significant higher rates of MACCE(P=0.011), mainly driven by the significant higher rates of repeat revascularization(HR=2.46, 95%CI 1.662-3.642, P<0.001). However, stroke rate was still significantly higher in CABG group than in PCI group(P=0.001)after multivariate adjusting. After propensity score matching (PSM), there was no more significant difference for all covariates in the matched cohorts (202 pairs). Further PSM analysis showed that overall findings were consistent with multivariate Cox hazard regression model except for MI (PCI 12.7% vs. CABG 3.8%, P=0.039). Conclusions: During a follow-up up to 8.3 years, the survival rate is similar between the PCI and the CABG group in patients with unprotected left main bifurcation disease.The rate of repeat revascularization is significantly higher whereas stroke rate is significantly lower in the PCI group compared to CABG group.After propensity score matching, PCI group not only had a significant higher rate of repeat revascularization, but also had significantly higher risk of MI in the matched cohorts; while they did not seem to translate into any disparity of mortality in ULMCA bifurcation disease patients.Accordingly, PCI for ULMCA disease can be used as a reasonable treatment option alternative to CABG.

[Efficacy comparison between conservative therapy and septal ablation in patients with hypertrophic obstructive cardiomyopathy]

Objective: To compare the effects of septal ablation (SA) versus conservative medication (CM) on the hemodynamic, clinical status and survival in patients with hypertrophic obstructive cardiomyopathy (HOCM). Methods: This retrospective study included 350 consecutive patients with HOCM (mean age (51.3±13.5) years old) hospitalized in Anzhen Hospital between September 2002 to September 2014. The patients were followed up to 14 years and the follow up rate was 99.4% (348/350). Overall and cardiac-related mortalities were compared between SA group (n=184) and CM group (n=184). Moreover, SA related cardiac function and hemodynamics improvement were also evaluated, predictors for clinical events were evaluated by Cox regression analysis and Kaplan-Meier survival analysis was used to compare the total mortality between the two groups. The log-rank test was used to compare the survival curve differences between the two groups. Results: The median follow-up period was 4 years (1-14 years). The annual mortalities of SA and CM were 2.4% and 0.6% respectively (P<0.001) and cumulative sudden cardiac death (SCD)rates were 3.61% (6/166) and 0.54% (1/184) respectively (P=0.031). Multivariate regression analysis demonstrated that the age was the most important independent predictor for overall mortality(HR=1.259, 95%CI 1.101-1.438, P=0.001). In addition, left ventricular outflow tract (LVOT) gradient was significantly reduced post SA (peak velocity of LVOT: baseline (4.23±1.05) m/s, post SA: (1.83±0.79) m/s, P<0. 01) and heart function was also significantly improved post SA (NYHA at baseline: 2.97±0.29, post SA: 1.74±0.53, P<0.001). Conclusion: SA could significantly improve the hemodynamics and clinical status in drug-resistant patients with HOCM. In comparison to patients received CM, overall survival rate was significantly higher in SA group without extra risk of SCD.

Association between TXNRD1 polymorphisms and anti-tuberculosis drug-induced hepatotoxicity in a prospective study

Anti-tuberculosis drug-induced hepatotoxicity (ATDH) is a serious adverse reaction to anti-tuberculosis (TB) treatment. Thioredoxin reductase 1 (TXNRD1), encoded by the TXNRD1 gene, is an important enzyme involved in oxidant challenge. TXNRD1 plays a key role in regulating cell growth and transformation, and protects cells against oxidative damage. We investigated the association between TXNRD1 polymorphisms and ATDH susceptibility. In this prospective study, 280 newly diagnosed TB patients were followed-up for 3 months after beginning anti-TB therapy. Tag single-nucleotide polymorphisms (tag-SNPs) of TXNRD1 were selected using Haploview 4.2 based on the HapMap database of the Chinese Han in Beijing (CHB) panel. Genotyping was performed using the MassARRAY platform. Of the 280 patients enrolled in this study, 33 were lost to follow-up, 24 had ATDH, and 223 were free from ATDH. After adjusting for sex, age, smoking status, and body mass index, there were no significant differences in the allele and genotype frequency distributions of TXNRD1 SNPs between the ATDH and non-ATDH groups (all P > 0.05). The haplotype analysis showed that haplotype TCAGCC was associated with an increased risk of ATDH susceptibility [P = 0.024, OR (95%CI) = 6.273 (1.023-38.485)]. Further stratified analyses showed that the haplotype TCAGCC was associated with ATDH susceptibility in female subjects [P = 0.036, OR (95%CI) = 5.711 (0.917-35.560)] and non-smokers [P = 0.029, OR (95%CI) = 6.008 (0.971-37.158)]. Our results suggest that TXNRD1 variants may favor ATDH susceptibility in females and non-smokers. Further studies are required to verify this association.

[Clinical value of serum presepsin (SCD14-ST) concentration measurement in patients with pesticide poisoning]

OBJECTIVE

To investigate the value of serum presepsin concentration measurement in the clinical diagnosis and treatment of patients with pesticide poisoning patients.

METHODS

A total of 160 patients with pesticide poisoning were enrolled as study subjects and divided into moderate organophosphate pesticide poisoning group (40 patients) , severe organophosphate pesticide poisoning group (40 patients) , abamectin pesticide poisoning group (40 patients) , and paraquat poisoning group (40 patients). A total of 20 healthy volunteers were enrolled as the control group. All the patients with poisoning received conventional treatment of pesticide poisoning immediately after admission, and serum presepsin concentration was measured on days 1 (within 24 hours after poisoning) , 3, and 7 of admission, and biochemical and radiological parameters related to the patient's condition were also examined. The patients with a Presepsin concentration of >800 pg/ml on day 1 of admission were randomly divided into conventional treatment group and ulinastatin treatment group, and the treatment outcome was compared between the two groups.

RESULTS

Compared with the healthy control group, the groups with pesticide poisoning showed significant increases in serum Presepsin concentrations, with the highest degree of increase on day 1 (P <0.05). The serum Presepsin concentration was positively correlated with alanine aminotransferase, aspartate aminotransferase, creatine kinase, creatine kinase MB, lactate dehydrogenase, serum creatinine, blood urea nitrogen, interleukin-18, and white blood cell count, but negatively correlated with cholinesterase. In the conventional treatment group and ulinastatin treatment group, the overall response rate was 68% and 78.8%, respectively, with a significant difference between the two groups (P<0.05). In 40 patients with paraquat poisoning, 32 experienced an increase in serum presepsin concentration, and among these 32 patients, 27 (83%) experienced exudation on lung CT.

CONCLUSION

Serum Presepsin concentration measurement can assist early diagnosis, evaluation of disease severity, and guidance for clinical medication in patients with pesticide poisoning, especially in those with severe pesticide poisoning and a tendency to multiple organ failure.

[Relationship between the mean platelet aggregation degree and the prognosis of patients underwent long-term dual antiplatelet therapy following drug eluting stent implantation]

OBJECTIVE

To evaluate the association between the mean platelet aggregation degree and the prognosis of patients underwent long-term dual antiplatelet therapy (DAPT more than 12 months) following drug eluting stent (DES) implantation.

METHODS

A total of 752 patients were retrospectively analyzed who were received DES between September 2006 and June 2009. Adenosine diphosphate-induced platelet aggregation (ADP) was monitored during the course of treatment with DAPT, and the mean platelet aggregation degree of each participant was calculated. Based on the mean platelet aggregation degree, patients were divided into the low ADP degree group (374 cases) and the high ADP degree group (378 cases). The median follow-up period was 32.2(25.1, 34.8) months. The comparison of the composite endpoints (all-cause death, nonfatal myocardial infarction, stent thrombosis, repeat revascularization and stroke) was performed between the two groups.

RESULTS

Compared with the high ADP degree group, there were more male, younger and smoker patients in the low ADP degree group (all P<0.05). COX regression analysis showed that the low ADP degree group was associated with a decreased incidence of primary endpoints (HR=0.463, 95%CI 0.23-0.92, P=0.028). After adjustment with multivariable COX regression analysis, the relationship was proven to be independent of other risk factors (HR=0.495, 95%CI 0.25-0.99, P=0.046). The Kaplan-Meier curve demonstrated the incidence of the composite endpoints was significantly higher in high ADP degree group compared to that of low ADP degree group (log-rank χ(2)=5.042, P=0.025).

CONCLUSION

The mean adenosine diphosphate-induced platelet aggregation degree is associated with the prognosis of patients underwent long term DAPT after DES implantation.

Combination of the Manifold Dimensionality Reduction Methods with Least Squares Support vector machines for Classifying the Species of Sorghum Seeds

This study was carried out for rapid and noninvasive determination of the class of sorghum species by using the manifold dimensionality reduction (MDR) method and the nonlinear regression method of least squares support vector machines (LS-SVM) combing with the mid-infrared spectroscopy (MIRS) techniques. The methods of Durbin and Run test of augmented partial residual plot (APaRP) were performed to diagnose the nonlinearity of the raw spectral data. The nonlinear MDR methods of isometric feature mapping (ISOMAP), local linear embedding, laplacian eigenmaps and local tangent space alignment, as well as the linear MDR methods of principle component analysis and metric multidimensional scaling were employed to extract the feature variables. The extracted characteristic variables were utilized as the input of LS-SVM and established the relationship between the spectra and the target attributes. The mean average precision (MAP) scores and prediction accuracy were respectively used to evaluate the performance of models. The prediction results showed that the ISOMAP-LS-SVM model obtained the best classification performance, where the MAP scores and prediction accuracy were 0.947 and 92.86%, respectively. It can be concluded that the ISOMAP-LS-SVM model combined with the MIRS technique has the potential of classifying the species of sorghum in a reasonable accuracy.

Broad temperature plateau for thermoelectric figure of merit ZT>2 in phase-separated PbTe0.7S0.3

Thermoelectrics interconvert heat to electricity and are of great interest in waste heat recovery, solid-state cooling and so on. The efficiency of thermoelectric materials depends directly on the average ZT (dimensionless figure of merit) over a certain temperature range, which historically has been challenging to increase. Here we report that 2.5% K-doped PbTe0.7S0.3 achieves a ZT of >2 for a very wide temperature range from 673 to 923 K and has a record high average ZT of 1.56 (corresponding to a theoretical energy conversion efficiency of ~20.7% at the temperature gradient from 300 to 900 K). The PbTe0.7S0.3 composition shows spinodal decomposition with large PbTe-rich and PbS-rich regions where each region exhibits dissimilar types of nanostructures. Such high average ZT is obtained by synergistically optimized electrical- and thermal-transport properties via carrier concentration tuning, band structure engineering and hierarchical architecturing, and highlights a realistic prospect of wide applications of thermoelectrics.

CRIg mediates early Kupffer cell responses to adenovirus

Whereas adenoviral vectors are known to activate the complement cascade, leading to fixation of C3 proteins to the viral capsid, the consequences of this activation for viral clearance from the circulation are not known. Liver KCs, the macrophage population responsible for early uptake and elimination of many blood-borne pathogens, express CRIg, a complement receptor for C3 proteins. Here, we find that CRIg is important for the early elimination of C3-coated adenoviral vectors from the sinusoidal bloodstream by KCs. We further demonstrate that by acting as a critical receptor for adenovirus phagocytosis, CRIg plays an important role in regulating virus-induced KC death and depletion of these cells from the liver sinusoidal lumen. Our study thus identifies a critical pathway regulating KC function and survival in response to systemic viral infection.

Complement receptor of the Ig superfamily enhances complement-mediated phagocytosis in a subpopulation of tissue resident macrophages

An important function of the complement cascade is to coat self and foreign particles with C3-proteins that serve as ligands for phagocytic receptors. Although tissue resident macrophages play an important role in complement-mediated clearance, the receptors coordinating this process have not been well characterized. In the present study, we identified a subpopulation of resident peritoneal macrophages characterized by high expression of complement receptor of the Ig superfamily (CRIg), a recently discovered complement C3 receptor. Macrophages expressing CRIg showed significantly increased binding and subsequent internalization of complement-opsonized particles compared with CRIg negative macrophages. CRIg internalized monovalent ligands and was able to bind complement-opsonized targets in the absence of Ca(2+) and Mg(2+), which differs from the beta(2)-integrin CR3 that requires divalent cations and polyvalent ligands for activation of the receptor. Although CRIg dominated in immediate binding of complement-coated particles, CRIg and CR3 contributed independently to subsequent particle phagocytosis. CRIg thus identifies a subset of tissue resident macrophages capable of increased phagocytosis of complement C3-coated particles, a function critical for immune clearance.

A role of macrophage complement receptor CRIg in immune clearance and inflammation

Complement receptor of the immunoglobulin superfamily (CRIg), also referred to as Z39Ig and V-set and Ig domain-containing 4 (VSIG4), has recently been implicated in the clearance of systemic pathogens and autologous cells. CRIg is exclusively expressed on tissue resident macrophages and binds to multimers of C3b and iC3b that are covalently attached to particle surfaces. Next to functioning as an important clearance receptor, CRIg's extracellular domain inhibits complement activation through the alternative, but not the classical, pathway, providing a novel tool to selectively block this pathway in vivo. Here, we review a role for CRIg in immune clearance, T-cell responses and complement regulation, and discuss the implications for disease manifestation.

Control of canonical NF-kappaB activation through the NIK-IKK complex pathway

Articles in recent years have described two separate and distinct NF-kappaB activation pathways that result in the differential activation of p50- or p52-containing NF-kappaB complexes. Studies examining tumor-necrosis factor receptor-associated factors (TRAFs) have identified positive roles for TRAF2, TRAF5, and TRAF6, but not TRAF3, in canonical (p50-dependent) NF-kappaB activation. Conversely, it recently was reported that TRAF3 functions as an essential negative regulator of the noncanonical (p52-dependent) NF-kappaB pathway. In this article, we provide evidence that TRAF3 potently suppresses canonical NF-kappaB activation and gene expression in vitro and in vivo. We also demonstrate that deregulation of the canonical NF-kappaB pathway in TRAF3-deficient cells results from accumulation of NF-kappaB-inducing kinase (NIK), the essential kinase mediating noncanonical NF-kappaB activation. Thus, our data demonstrate that inhibition of TRAF3 results in coordinated activation of both NF-kappaB activation pathways.

TRAF3 and its biological function

Tumor necrosis factor receptor associated factor 3 (TRAF3) is one of the most enigmatic members in the TRAF family that consists of six members, TRAF1 to 6. Despite its similarities with other TRAFs in terms of structure and protein-protein association, overexpression of TRAF3 does not induce activation of the commonly known TRAF-inducible signaling pathways, namely NF-kappaB and JNK. This lack of a simple functional assay in combination with the mysterious early lethality of the TRAF3-deficient mice has made the study of the biological function of TRAF3 challenging for almost ten years. Excitingly, TRAF3 has been identified recently to perform two seemingly distinct roles. Namely, TRAF3 functions as a negative regulator of the NF-kappaB pathway and separately, as a positive regulator of type I IFN production, placing itself as a critical regulator of both innate and adaptive immune responses.

Specificity of TRAF3 in its negative regulation of the noncanonical NF-kappa B pathway

Tumor necrosis factor (TNF) receptor-associated factors (TRAFs) are critical signaling adaptors downstream of many receptors in the TNF receptor and interleukin-1 receptor/Toll-like receptor superfamilies. Whereas TRAF2, 5, and 6 are activators of the canonical NF-kappaB signaling pathway, TRAF3 is an inhibitor of the noncanonical NF-kappaB pathway. The contribution of the different domains in TRAFs to their respective functions remains unclear. To elucidate the structural and functional specificities of TRAF3, we reconstituted TRAF3-deficient cells with a series of TRAF3 mutants and assessed their abilities to restore TRAF3-mediated inhibition of the noncanonical NF-kappaB pathway as measured by NF-kappaB-inducing kinase (NIK) protein levels and processing of p100 to p52. We found that a structurally intact RING finger domain of TRAF3 is required for inhibition of the noncanonical NF-kappaB pathway. In addition, the three N-terminal domains, but not the C-terminal TRAF domain, of the highly homologous TRAF5 can functionally replace the corresponding domains of TRAF3 in suppression of the noncanonical NF-kappaB pathway. This functional specificity correlates with the specific binding of TRAF3, but not TRAF5, to the previously reported TRAF3 binding motif in NIK. Our studies suggest that both the RING finger domain activity and the specific binding of the TRAF domain to NIK are two critical components of TRAF3 suppression of NIK protein levels and the processing of p100 to p52.

Rescue of TRAF3-null mice by p100 NF-kappa B deficiency

Proper activation of nuclear factor (NF)–κB transcription factors is critical in regulating fundamental biological processes such as cell survival and proliferation, as well as in inflammatory and immune responses. Recently, the NF-κB signaling pathways have been categorized into the canonical pathway, which results in the nuclear translocation of NF-κB complexes containing p50, and the noncanonical pathway, which involves the induced processing of p100 to p52 and the formation of NF-κB complexes containing p52 (Bonizzi, G., and M. Karin. 2004. Trends Immunol. 25:280–288). We demonstrate that loss of tumor necrosis factor (TNF) receptor–associated factor 3 (TRAF3) results in constitutive noncanonical NF-κB activity. Importantly, TRAF3^−/− B cells show ligand-independent up-regulation of intracellular adhesion molecule 1 and protection from spontaneous apoptosis during in vitro culture. In addition, we demonstrate that loss of TRAF3 results in profound accumulation of NF-κB–inducing kinase in TRAF3^−/− cells. Finally, we show that the early postnatal lethality observed in TRAF3-deficient mice is rescued by compound loss of the noncanonical NF-κB p100 gene. Thus, these genetic data clearly demonstrate that TRAF3 is a critical negative modulator of the noncanonical NF-κB pathway and that constitutive activation of the noncanonical NF-κB pathway causes the lethal phenotype of TRAF3-deficient mice.

Regulation of antiviral responses by a direct and specific interaction between TRAF3 and Cardif

Upon recognition of viral infection, RIG-I and Helicard recruit a newly identified adapter termed Cardif, which induces type I interferon (IFN)-mediated antiviral responses through an unknown mechanism. Here, we demonstrate that TRAF3, like Cardif, is required for type I interferon production in response to intracellular double-stranded RNA. Cardif-mediated IFNalpha induction occurs through a direct interaction between the TRAF domain of TRAF3 and a TRAF-interaction motif (TIM) within Cardif. Interestingly, while the entire N-terminus of TRAF3 was functionally interchangeable with that of TRAF5, the TRAF domain of TRAF3 was not. Our data suggest that this distinction is due to an inability of the TRAF domain of TRAF5 to bind the TIM of Cardif. Finally, we show that preventing association of TRAF3 with this TIM by mutating two critical amino acids in the TRAF domain also abolishes TRAF3-dependent IFN production following viral infection. Thus, our findings suggest that the direct and specific interaction between the TRAF domain of TRAF3 and the TIM of Cardif is required for optimal Cardif-mediated antiviral responses.

Critical role of TRAF3 in the Toll-like receptor-dependent and -independent antiviral response

Type I interferon (IFN) production is a critical component of the innate defence against viral infections. Viral products induce strong type I IFN responses through the activation of Toll-like receptors (TLRs) and intracellular cytoplasmic receptors such as protein kinase R (PKR). Here we demonstrate that cells lacking TRAF3, a member of the TNF receptor-associated factor family, are defective in type I IFN responses activated by several different TLRs. Furthermore, we show that TRAF3 associates with the TLR adaptors TRIF and IRAK1, as well as downstream IRF3/7 kinases TBK1 and IKK-epsilon, suggesting that TRAF3 serves as a critical link between TLR adaptors and downstream regulatory kinases important for IRF activation. In addition to TLR stimulation, we also show that TRAF3-deficient fibroblasts are defective in their type I IFN response to direct infection with vesicular stomatitis virus, indicating that TRAF3 is also an important component of TLR-independent viral recognition pathways. Our data demonstrate that TRAF3 is a major regulator of type I IFN production and the innate antiviral response.

Unique CD40-mediated biological program in B cell activation requires both type 1 and type 2 NF-kappaB activation pathways

B lymphocytes can be activated by many different stimuli. However, the mechanisms responsible for the signaling and functional specificities of individual stimuli remain to be elucidated. Here, we have compared the contribution of the type 1 (p50-dependent) and type 2 (p52-dependent) NF-kappaB activation pathways to cell survival, proliferation, homotypic aggregation, and specific gene regulation of murine primary B lymphocytes. Whereas lipopolysaccharide (LPS) and B cell activation factor (BAFF) mainly activate the type 1 or type 2 pathways, respectively, CD40 ligand (CD40L) strongly activates both. Rescue of spontaneous apoptosis is diminished in p52(-/-) B cells after BAFF stimulation and in p50(-/-)c-Rel(-/-) B cells after LPS stimulation. Interestingly, significant CD40-induced B cell survival is still observed even in p50(-/-)c-Rel(-/-)p65(-/+) B cells, which is correlated with the ability of CD40L to up-regulate Bcl-x(L) expression in these cells. CD40L- and LPS-induced B cell proliferation, as well as up-regulation of proliferation-related genes, however, are greatly reduced in c-Rel(-/-) and p50(-/-)c-Rel(-/-) B cells but are normal in p52(-/-) B cells. We have further demonstrated that both c-Rel and p52 are required for CD40-mediated B cell homotypic aggregation, which explains well why neither LPS nor BAFF has this function. Overall, our studies suggest that both type 1 and type 2 NF-kappaB pathways contribute to the gene expression and biological program unique for CD40 in B cell activation.

The signaling adaptors and pathways activated by TNF superfamily

Members of the TNF receptor superfamily play pivotal roles in numerous biological events in metazoan organisms. Ligand-mediated trimerization by corresponding homo- or heterotrimeric ligands, the TNF family ligands, causes recruitment of several intracellular adaptors, which activate multiple signal transduction pathways. While recruitment of death domain (DD) containing adaptors such as Fas associated death domain (FADD) and TNFR associated DD (TRADD) can lead to the activation of a signal transduction pathway that induces apoptosis, recruitment of TRAF family proteins can lead to the activation of transcription factors such as, NF-kappaB and JNK thereby promoting cell survival and differentiation as well as immune and inflammatory responses. Individual TNF receptors are expressed in different cell types and have a range of affinities for various intracellular adaptors, which provide tremendous signaling and biological specificities. In addition, numerous signaling modulators are involved in regulating activities of signal transduction pathways downstream of receptors in this superfamily. Most of the TNF receptor superfamily members as well as many of their signaling mediators, have been uncovered in the last two decades. However, much remains unknown about how individual signal transduction pathways are regulated upon activation by any particular TNF receptor, under physiological conditions.

Recent developments in the genetics of asthma

Asthma is a complex genetic disease with multiple genes involved in the pathogenesis. Some of these genes have been investigated to determine whether they influence an individual's response to asthma medication. We summarise the recent developments in the genetics of asthma as they pertain to the three main treatments available - inhaled glucocorticoids (GCs), (2)-agonists and leukotriene modulators. It has been shown that polymorphisms in the (2)-adrenergic receptor ((2)AR) gene influence responsiveness to (2)-agonists. Polymorphisms in the 5-lipoxygenase (5-LO) gene and the leukotriene C(4) (LTC4) synthase gene have been associated with response to medications that target the LT pathway. However, no polymorphisms have been identified that influence response to anticholinergics or are involved in steroid resistance. In the future, knowledge of an individual's genotype may help us tailor treatment to make it the most appropriate form for that asthmatic individual.

TSO1 is a novel protein that modulates cytokinesis and cell expansion in Arabidopsis

Previous analyses of tso1 mutants revealed a loss of control of directional cellular expansion and coordination of growth of adjacent cells, and defects in karyokinesis and cytokinesis. We isolated TSO1 using a map-based approach, and show that it is a member of a family of at least three genes in Arabidopsis. Consistent with the mutant phenotype, TSO1 transcript was most abundant in flowers, where it accumulated to the highest levels in developing ovules and microspores. The putative TSO1 protein has two cysteine-rich regions that are similar to the CXC domains of a variety of proteins from plants and animals, including a class of kinesins involved in chromosome segregation, and enhancer of zeste-type proteins. Visualization of TSO1-fusion proteins indicated that TSO1 is a nuclear protein. The tso1 mutant phenotypes and the novelty of the TSO1 sequence suggest the existence of previously unknown participants in regulation of directional processes in eukaryotic cells.

Endothelin-1 and photoreleased diacylglycerol increase L-type Ca2+ current by activation of protein kinase C in rat ventricular myocytes

The amphotericin B-perforated whole-cell patch clamp technique was used to determine the modulation of L-type Ca2+ channels by protein kinase C (PKC)-mediated pathways in adult rat ventricular myocytes. Application of 10 nM endothelin-1 (ET-1) increased peak Ca2+ current (ICa) by 28.2 +/- 2.5 % (n = 13) and slowed current decay. These effects were prevented by the endothelin receptor antagonist PD145065 (10 microM) and by the PKC inhibitor chelerythrine (8 microM). To establish if direct activation of PKC mimicked the ET-1 effect, the active and inactive phorbol esters (phorbol-12-myristate-13-acetate and 4alpha-phorbol-12, 13-didecanoate) were tested. Both phorbol esters (100 nM) resulted in a small (approximately 10%) increase in ICa, suggesting PKC-independent effects. Bath application of dioctanoylglycerol (diC8), a diacylglycerol (DAG) analogue which is capable of directly activating PKC, caused a gradual decline in peak ICa (50.4 +/- 6.2 %, n = 5) and increased the rate of current decay. These effects were unaffected by the PKC inhibitor chelerythrine (8 microM). Intracellular photorelease of caged diC8 with 3 or 10 s exposure to UV light produced a concentration-dependent increase in peak ICa (20. 7 +/- 8.5 % (n = 8) for 3 s UV and 60.8 +/- 11.4 % (n = 13) for 10 s UV), which could be inhibited by chelerythrine. Our results demonstrate that both ET-1 and intracellularly photoreleased diC8 increase ICa by a PKC-mediated pathway, which is in direct contrast to the PKC-independent inhibition of ICa produced by bath-applied diC8. We conclude that specific cellular pools of DAG are crucially important in the regulation of ICa by PKC.