Association between workplace health promotion service utilisation and depressive symptoms among workers: a nationwide survey

OBJECTIVES

Workplace-related factors are associated with the risk of depression. Despite implementation of workplace health promotion (WHP) programmes in China to promote the physical and mental well-being of workers, the relationship between WHP and depression has received limited attention. This study investigated the association between WHP service utilisation and depressive symptoms among workers.

STUDY DESIGN

This was a cross-sectional survey.

METHODS

A researcher-designed questionnaire was used to collect information on socio-demographic and occupational characteristics, WHP service utilisation, and mental health status. The Lasso method was used for variable selection to achieve dimension reduction, and logistic regression was used to assess the association between WHP service utilisation and depressive symptoms.

RESULTS

The analysis included 11,710 workers, of whom 17.0% had depressive symptoms. Lasso regression resulted in 6 of 18 WHP services showing significant negative associations with depressive symptoms, including occupational safety training, mental health services, health check-ups, sports activities, fitness rooms, and healthy canteens. The logistic regression results showed that, after adjusting for sociodemographic and occupational factors, utilisation of these six services was associated with a decreased likelihood of depressive symptoms. The adjusted odds ratio (aOR) was 0.84 (95% confidence interval [CI]: 0.73-0.96) for occupational safety training, aOR: 0.82 (95% CI: 0.68-0.99) for mental health services, aOR: 0.80 (95% CI: 0.71-0.90) for health check-ups, aOR: 0.68 (95% CI: 0.57-0.80) for sports activities, aOR: 0.59 (95% CI: 0.47-0.74) for fitness rooms and aOR: 0.72 (95% CI: 0.59-0.87) for healthy canteens.

CONCLUSIONS

Utilisation of WHP services was associated with a lower prevalence of depressive symptoms. Implementation of WHP services and the provision of a supportive workplace environment should be prioritised to benefit the mental health of workers.

[Impact of NLR on atrial fibrillation recurrence after radiofrequency ablation in atrial fibrillation patients combined with heart failure]

Objective: To investigate the predictive value of neutrophils-to-lymphocytes ratio (NLR) for atrial fibrillation recurrence after radiofrequency ablation in atrial fibrillation patients combined with heart failure. Methods: This is a retrospective cohort study. Patients with atrial fibrillation and heart failure who received radiofrequency ablation in the First Affiliated Hospital of Zhengzhou University from January 2019 to June 2020 were included. Patient were followed up in the outpatient clinic at 3, 6, 9 and 12 months after radiofrequency ablation and were divided into recurrent and non-recurrent groups according to the absence or presence of atrial fibrillation. Demographic data, echocardiographic indices and inflammation-related indices including NLR were collected and compared between the two groups. Spearman rank correlation was performed to analyze the correlation of NLR with atrial fibrillation recurrence after radiofrequency ablation. Multivariate logistic regression analysis was used to determine independent risk factors of atrial fibrillation recurrence after radiofrequency ablation. The receiver operating characteristic (ROC) curve was used to evaluate the value of NLR in predicting the atrial fibrillation recurrence after radiofrequency ablation. Results: A total of 883 patients were included, of which 460 (52.1%) were male, mean age was (64.4±10.7) years old. There were 246 patients (27.9%) in the recurrence group and 637 patients (72.1%) in the non-recurrence group. Compared with the non-recurrent group, the duration of atrial fibrillation, NLR, neutrophil count, N-terminal B-type natriuretic peptide precursor (NT-proBNP) and body mass index levels were significantly higher, while lymphocyte count was significantly lower in the recurrence group than in the non-recurrent group (all P<0.05). Spearman rank correlation analysis showed that NLR was positively correlated with the atrial fibrillation recurrence (r=0.333, P<0.05). Multivariate logistic regression analysis showed that NLR was an independent risk factor for atrial fibrillation recurrence after radiofrequency ablation in atrial fibrillation patients combined heart failure (OR=1.634, P<0.001). The ROC curve showed that the area under the curve (AUC) of NLR in predicting the recurrence of atrial fibrillation after radiofrequency ablation was 0.715 (95%CI: 0.668-0.762, P<0.001), with a sensitivity of 55.61% and a specificity of 84.54%. Conclusion: NLR is a useful predictor of atrial fibrillation recurrence after radiofrequency ablation in atrial fibrillation patients combined with heart failure.

[Metagenomic data-analysis reveals enrichment of lipopolysaccharide synthesis in the gut microbiota of atrial fibrillation patients]

Objective: To investigate the functional changes of key gut microbiota (GM) that produce lipopolysaccharide (LPS) in atrial fibrillation (AF) patients and to explore their potential role in the pathogenesis of AF. Methods: This was a prospective cross-sectional study. Patients with AF admitted to Beijing Chaoyang Hospital of Capital Medical University were enrolled from March 2016 to December 2018. Subjects with matched genetic backgrounds undergoing physical examination during the same period were selected as controls. Clinical baseline data and fecal samples were collected. Bacterial DNA was extracted and metagenomic sequencing was performed by using Illumina Novaseq. Based on metagenomic data, the relative abundances of KEGG Orthology (KO), enzymatic genes and species that harbored enzymatic genes were acquired. The key features were selected via the least absolute shrinkage and selection operator (LASSO) analysis. The role of GM-derived LPS biosynthetic feature in the development of AF was assessed by receiver operating characteristic (ROC) curve, partial least squares structural equation modeling (PLS-SEM) and logistic regression analysis. Results: Fifty nonvalvular AF patients (mean age: 66.0 (57.0, 71.3), 32 males(64%)) were enrolled as AF group. Fifty individuals (mean age 55.0 (50.5, 57.5), 41 males(82%)) were recruited as controls. Compared with the controls, AF patients showed a marked difference in the GM genes underlying LPS-biosynthesis, including 20 potential LPS-synthesis KO, 7 LPS-biosynthesis enzymatic genes and 89 species that were assigned as taxa harbored nine LPS-enzymatic genes. LASSO regression analysis showed that 5 KO, 3 enzymatic genes and 9 species could be selected to construct the KO, enzyme and species scoring system. Genes enriched in AF group included 2 KO (K02851 and K00972), 3 enzymatic genes (LpxH, LpxC and LpxK) and 7 species (Intestinibacter bartlettii、Ruminococcus sp. JC304、Coprococcus catus、uncultured Eubacterium sp.、Eubacterium sp. CAG:251、Anaerostipes hadrus、Dorea longicatena). ROC curve analysis revealed the predictive capacity of differential GM-derived LPS signatures to distinguish AF patients in terms of above KO, enzymatic and species scores: area under curve (AUC)=0.957, 95%CI: 0.918-0.995, AUC=0.940, 95%CI 0.889-0.991, AUC=0.972, 95%CI 0.948-0.997. PLS-SEM showed that changes in lipopolysaccharide-producing bacteria could be involved in the pathogenesis of AF. The key KO mediated 35.17% of the total effect of key bacteria on AF. After incorporating the clinical factors of AF, the KO score was positively associated with the significantly increased risk of AF (OR<0.001, 95%CI:<0.001-0.021, P<0.001). Conclusion: Microbes involved in LPS synthesis are enriched in the gut of AF patients, accompanied with up-regulated LPS synthesis function by encoding the LPS-enzymatic biosynthesis gene.

LGE-cMRI assessment of volume controlled reperfusion method in primary percutaneous coronary intervention in patients with ST elevated myocardial infarction

Objectives

We create a procedure based on postconditioning and gradual reperfusion, “Volume Controlled Reperfusion Revascularization” method (VCR)in primary percutaneous coronary intervention. The aim of this experimental study is to assess feasibility and effect of VCR and if this method will attenuate reperfusion injury in microvascular obstruction.

Methods

VCR method, Basically, contemporaneous forward blood flow balloon inflation blocking at the occlusion site and prolonged distal reperfusion via aspiration catheter. Active NC balloon inflation at occlusion site, while keeping NC balloon inflation, aspiration catheter was positioned 10–15mm advanced of NC balloon, intra-aspiration catheter infusion of mixture solution (artery blood 10ml+ heparin NS 10ml), 20ml/min for 10mins, adjust volume and speed according to blood pressure and heart rate variation. Stent or DCB as usual. After several successful operation on RCA, 10 patients with acute ST-segment elevation myocardial infarction (STEMI)with angiography confirmed proximal complete occlusion on dominant blood vessel were non-randomly enrolled (symptom to angiography &lt;12h). 5 cases in VCR group with volume-controlled reperfusion revascularization method, 5 cases in control group with conventional PCI method. Microvascular obstruction (MVO) has been calculated by late gadolinium-enhanced cardiovascular magnetic resonance (LGE-cMRI). Base line information, angiographic features before and after procedure, in-hospital status and MVO were compared.

Results

Successful PCI procedure, safe in-hospital treatment and LGE-cMRI assessment for MVO. Group difference were found in age group and PCI to MRI interval (53.8±7.6 vs 70.2±4.44, P=0.0031; 7.4±2.3 vs 10.4±1.67, P=0.046) between VCR and control group, respectively. There was no statistic difference in other base line information, peak myocardial enzyme, and BNP. MVO and MVO mass ratio was significantly lower in VCR group (0.78±0.96 vs 2.80±1.37, P=0.0317; 0.00585±0.00080 vs 0.02493±0.01501, P=0.0372). TIMI III blood flow found in VCR group. Re-myocardial infraction nor target vessel revascularization was documented in-hospital or 30-days follow up.

Conclusion

Among the selected small sample cases, volume-controlled reperfusion method procedure was clinical safe and feasible without additional side effect. TIMI III blood flow and less MVO were documented.

Funding Acknowledgement

Type of funding sources: None. LGE-cMRI results in VCR and controlCase illustration of VCR procedure

[The effect of peripheral blood cell score on the prognosis of multiple myeloma patients treated with bortezomib]

目的

评估外周血细胞检测结果在以硼替佐米为一线治疗的多发性骨髓瘤（MM）患者中的预后作用。

方法

回顾性分析2014年1月至2016年12月浙江大学医学院附属第一医院和浙江省舟山医院收治的155例初诊MM患者的临床数据，患者均一线接受以硼替佐米为基础方案的治疗。分析外周血细胞检测结果，包括ANC、单核细胞计数（AMC）、HGB、红细胞平均体积（MCV）、PLT以及其他临床特征对MM患者的预后评估作用。

结果

AMC（>0.6×10⁹/L）、MCV（>99.1fl）以及PLT（<150×10⁹/L）明显影响MM患者无进展生存（PFS）和总生存（OS），以上3个因子分别赋值1分，形成血细胞积分。结果显示，64例（41.3％）积分0，57例（36.8％）积分1，32例（20.6％）积分2，2例（1.3％）积分3，4组患者中位PFS时间分别为42.8、26.5、15.8、6.4个月（P<0.001），中位OS时间分别为未达到和48.2、31.1、31.4个月（P＝0.001）。多因素分析提示，血细胞积分（2～3对0～1）和骨髓浆细胞比例（>30％对≤30％）为PFS的独立预后因素（HR分别为1.95和1.76），而患者年龄（>65岁对≤65岁）、R-ISS分期（Ⅲ期对Ⅰ～Ⅱ期）和血细胞积分（2～3对0～1）是OS的独立预后因素（HR分别为2.08、2.13和2.12）。

结论

血细胞积分简单易得，可用于新药时代初治MM患者的预后评估，但仍需扩大病例并进行前瞻性研究进一步明确。

[Assessment of mortality burden and economic loss attributed to long-term PM(2.5) exposure in the Beijing-Tianjin-Hebei area]

Objective: To accurately estimate the health burden and corresponding economic loss attributed to PM(2.5) pollution in the Beijing-Tianjin-Hebei (BTH) area in China in 2015. Method: By using satellite-retrieved PM(2.5) concentration data and population data provided by NASA (the spatial resolution was 1 km×1 km), this study estimated excess mortality attributed to long-term PM(2).5 exposure in BTH area in 2015 based on Global Exposure Mortality Model (GEMM). Besides, Value of Statistic Life (VSL) method was used to evaluate the corresponding health economic loss. Result: In BTH area, the population-weighted average PM(2.5) concentration during 2012-2014 was 46.25 μg/m(3), and 56.6% of total population lived in the area where annual average PM(2.5) concentration exceeded Grade Ⅱ of National Ambient Air Quality Standard in China (35 μg/m(3)); The PM(2.5)-related premature deaths amounted to 193.8 thousand (95%CI: 140.9 thousand-233.3 thousand), Beijing, Tianjin, Baoding, Shijiazhuang, and Handan were the top five cities with high incidences of PM(2.5)-related premature deaths; The corresponding health economic loss was about 35.934 billion (95%CI: 26.099 billion - 43.255 billion) RMB, accounting for 0.70% (95%CI: 0.51%-0.85%) of the area's GDP in 2015, Beijing, Tianjin, Baoding, Shijiazhuang, and Cangzhou were the top five cities with high health economic loss. Conclusions: PM(2.5) pollution has caused severe disease and economic burden in BTH area. Its spatial distribution suggested that it is particularly necessary to develop the air pollution prevention and control policies for key cities.

[Efficacy comparison of primary percutaneous coronary intervention by drug-coated balloon angioplasty or drug-eluting stenting in acute myocardial infarction patients with de novo coronary lesions]

Objective: To compare the safety profile, angiographic and clinical outcomes between drug-coated balloon(DCB) only strategy versus drug eluting stent(DES) implantation in primary percutaneous coronary intervention(PCI) for acute myocardial infarction(AMI) patients. Methods: A total of 380 AMI patients who underwent primary PCI in Beijing Chaoyang Hospital from January 2016 to May 2019 were enrolled. They were allocated into DEB group(n=180) or DES group(n=200). The Primary endpoint was the major adverse cardiac events(MACE) in hospital and within 3 months after discharge, the composite event of cardiac death, non-fatal myocardial infarction(MI), target vessel revascularization(TVR) and in stent thrombosis. The secondary endpoints included: (1)TIMI blood flow grade and myocardial perfusion grade (TMP grade) of infarct-related vessels before and after PCI. (2)The degree of ST segment resolution(STR) between half hour and two hours after PCI, and STR was represented by percentage of summed ST-segment reduction between baseline and post-PCI. Using the most significant lead of ST segment elevation, calculating the rate of decline in the ST segment after treatment; or the most significant lead of the ST segment depression, to calculate the rate of recovery in the ST segment after treatment. STR<50% was defined as incomplete STR. (3)The occurrence of coronary artery dissection during operation. (4)The peak value of myocardial enzymes. (5)The incidence of bleeding in hospital and within 3 months after discharge. The inverse probability weighting method based on propensity score (IPTW) was used to compare the effects of the two treatments on MACE occurrence in the logistic regression model. Results: There was no significant difference in sex, age, risk factors of coronary heart disease, type and site of AMI, interventional therapy data(P>0.05) between the two groups. The ratio of bifurcation lesions in DCB group was significantly higher than that in DES group, and the diameter of the DCB was smaller while the length was longer than that of DES (all P<0.05). One death occurred in each group during hospitalization. Compared with the DES group, the incidence of MI ［2.8%(5/180) vs. 0.5% (1/200), P=0.10］ and TVR ［2.8%(5/180) vs. 0.5%(1/200), P=0.10］ in the DCB group during hospitalization showed an increasing trend, and were mostly associated with delayed coronary dissection. The incidence of MACE was similar between the two groups (3.3%(6/180) and 1.0%(2/200), P=0.15) during hospitalization. There was no MACE occurred in the two groups within 3 months after discharge. There was no significant difference between the two groups in TIMI grade, TMP grade, incomplete STR rate and peak value of myocardial enzyme (all P>0.05). The incidence of coronary artery dissection was significantly higher in DCB group than in DES group (8.3%(15/180) and 3.0%(6/200), P=0.02), but most of them were type B or A dissection and did not need special treatment. There was no significant difference in bleeding event between the two groups(P=0.91). Logistic regression analysis showed that there was no difference in the risk of MACE during hospitalization between DES and DCB groups for AMI patients receiving PCI (compared with DCB, OR=0.35, 95%CI 0.08-1.43, P=0.13). Conclusions: The initial safety and efficacy profiles of DCB are similar with those of DES for the AMI patients during PCI. The study highlights that the incidence of coronary dissection (type A or B) is higher post DCB treatment than post DES, but it does not affect blood flow. However, the incidence of in-hospital MI due to delayed coronary dissection trends to be higher post DCB. So we should pay close attention to the risk of delayed coronary dissection after DCB in AMI patients with de novo lesion.

[Causal relationship between sleep and coronary artery disease: a Mendelian randomization study]

Objective: To understand the causal relationship between sleep and coronary artery disease (CAD). Methods: This study included six genome-wide association parts; five for sleep related traits[sleep duration (continuous variable), long sleep duration (binary variable), short sleep duration (binary variable), early-to-bed/up habit (known as 'morningness') and frequently insomnia] and one for CAD. Heterogeneity in dependent instrument approach was used to assess and to remove the pleiotropic instruments. Generalized summary data-based Mendelian randomization was performed to estimate the causal relationships between sleep related traits and CAD. And a conservative Bonferroni was used for statistical tests. Results: Sleep duration was putatively causal for CAD (OR=0.755, 95%CI: 0.658-0.867, P=6.68E-05). Our results also indicated significant causal effects between both short sleep duration and frequently insomnia on CAD, with ORs as 4.251 (95%CI: 2.396-7.541, P=7.51E-07) and 1.814 (95%CI: 1.346-2.446, P=9.25E-05), respectively. There was no convincing evidence of causality between long sleep duration or morningness with CAD. Conclusions: Our findings suggested that both sleep duration and frequently insomnia played causal roles on CAD, indicating that disease models should include sleep duration and insomnia as potential factors for CAD to develop effective interventions.

[Relationship between red blood cell distribution width and left atrial appendage thrombogenic milieu in old patients with non-valvular atrial fibrillation]

Objective: To estimate the correlation between red cell distribution width (RDW) level and left atrial appendage thrombogenic milieu (LAATM) in elderly patients with non-valvular atrial fibrillation (NVAF). Methods: This was a retrospective case-control study. A total of 782 NVAF patients (age>60 years old) who finished transesophageal echocardiography (TEE) from January 2010 to December 2016 at Chaoyang Hospital was retrospectively screened, and diveded into LAATM group (n=65) and non LAATM group (n=717). RDW level was compared between the two groups. Potential association between RDW and LAATM was analyzed using multivariate logistic regression analysis. The accuracy of RDW for detecting LAATM was evaluated through receiver operating curve (ROC) analysis. Results: There were significant differences in age, history of heart failure, course of atrial fibrillation (AF), type of AF, NT-proBNP level, RDW level, left ventricular end systolic diameter, left ventricular end diastolic diameter, left ventricular ejection fraction (LVEF), left atrial diameter, CHADS(2) score and CHA(2)DS(2)-VASc score between the two groups (P<0.05). RDW level in LAATM group was significant higher than non LAATM group (13.4% (12.6%, 14.1%) vs. 12.1% (11.2%,13.0%), P<0.001). Multivariate logistic regression showed that RDW level associated with LAATM (OR=4.07, 95%CI 2.09-7.91, P<0.001). In ROC analysis, area under the curve was 0.81 (95%CI 0.74-0.88, P<0.001). When RDW level was 13.1%, LAATM could be diagnosed (sensitivity was 73.1% and specificity was 80.5%). Conclusions: RDW value is associated with the presence of LAATM in elderly NVAF patients. The RDW level has a certain reference value for predicting LAATM.

[Prognostic value of N-terminal B-type natriuretic peptide on all-cause mortality in heart failure patients with preserved ejection fraction]

Objective: To investigate the prognostic value of N-terminal B-type natriuretic peptide (NT-proBNP) on all-cause mortality in heart failure patients with preserved ejection fraction (HFpEF) at real world scenarios. Methods: Patients who met the diagnostic criteria of HFpEF in the China National Heart Failure Registration Study (CN-HF) were divided into death and survival groups. The demographic data, physical examination, results of the first echocardiography, laboratory results at admission, complications, drug use and clinical outcomes were obtained from CN-HF. The univariate Cox proportional hazard model was used to screen the variates that might predict prognosis, and then the covariates with statistical significance were included in the multivariate Cox regression model to analyze the predictive value of baseline NT-proBNP on all-cause death. Spearman correlation analysis was used to evaluate the relationship between NT-proBNP and estimated glomerular filtration rate (eGFR), so as to further explore the predictive value of the interaction between renal dysfunction and NT-proBNP on death. Since NT-proBNP did not obey the binary normal distribution, it was expressed by the natural logarithm of NT-proBNP (LnNT-proBNP). Results: A total of 1 846 HFpEF patients were enrolled in this study, with an average age of 71.5 years, 1 017 males(55.1%), median NT-proBNP 860 ng/L, and median eGFR 73.9 ml·min^-1·1.73m^-2. After a median follow-up of 34 months, 213 (11.5%) patients died. Patients in the death group were older, with higher NYHA classification Ⅲ-Ⅳ ratio, longer hospital stay, higher serum potassium and NT-proBNP level, prevalence of complications of diabetes mellitus, arrhythmia and atrial fibrillation, use of angiotensin receptor antagonist(ARB), mineralocorticoid receptor antagonists (MRA), diuretic and digoxin was significantly higher in death group than in survival group. Body mass index (BMI), diastolic blood pressure, left ventricular ejection fraction (LVEF), hemoglobin, serum cholesterol(TC), serum triglycerides (TG) and eGFR, and use of angiotensin converting enzyme inhibitors (ACEI), statins and aspirin were lower in death group than in survival group. Univariate Cox regression analysis showed that NT-proBNP was a predictor of all-cause death in HFpEF patients (HR=2.522, 95%CI 2.040-3.119, P<0.001). Multivariate Cox regression analysis showed that the elevated NT-proBNP remains as the independent predictor of all-cause death in patients with HFpEF (HR=1.230, 95%CI 1.049-1.442, P=0.011) after adjusting for age, BMI, diastolic blood pressure, LVEF, hemoglobin, serum potassium, serum sodium, TC, serum high-density lipoprotein cholesterol (HDL-C), TG, eGFR, atrial fibrillation, as well as the treatment of ACEI/ARB, MRA, diuretics and digoxin. Spearman correlation analysis showed that LnNT-proBNP was negatively correlated with eGFR (r=-0.361, P<0.001), but there was no interaction between NT-proBNP and renal dysfunction in predicting death in HFpEF patients (P>0.05). Conclusion: The elevated level of NT-proBNP at admission is an independent predictor of all-cause mortality in HFpEF patients.

P967Combined modified balloons and Saito's modified JBT for calcified coronary birucation lesions

Background

Bifurcation lesions are account for relatively high incidence of adverse events, especially in serious calcification and distort lesions during bifurcation stenting.

Purpose

Based on Saito's modified jailed balloon technique (M-JBT, Shigeru Saito, Modified jailed balloon technique for bifurcation lesions, Catheter Cardiovasc Interv. 2018; 92:E218–E226), fully dilatation with modified balloons was performed on calcification lesion in main branch, to observe if this combination method will facilitate bifurcation lesions stenting procedure.

Methods

For M-JBT, we followed Saito's technique. Basically, a jailed balloon (JB) is introduced into the side branch (SB), while a stent is placed in the main branch (MB) as crossing SB. The size of the JB is half of the MB stent size. While the proximal end of JB attaching to MB stent, both stent and JB are simultaneously inflated with same pressure. Kissing balloon dilatation (KBD) and/or T and protrusion (TAP) stenting are applied as needed.

Modified balloons are performed as severe calcification presented in MB.

Results

More than 50 patients and 60 bifurcations (both for selective and primary cases) underwent percutaneous coronary intervention (PCI) using this combined technique since November 2018. Procedure success was achieved in all cases. KBD was performed for a few lesions and TAP stenting was employed for 1 lesion. Occlusion of SV was not observed in any of the patients.

Illustration cases and prodedure

Conclusions

Saito's modified jailed balloon technique is safe and effective method in bifurcation stenting. Combined with modified balloons is an effective method when severe calcification presented in bifurcation lesions, especially in distort lesion (main branch or side branch) and poor position visualization situations when rewire is difficult in traditional JBT procedure.

Acknowledgement/Funding

None

P6013Evidence for ANTXR2 as a therapeutic target on systemic-to-pulmonary shunt induced pulmonary arterial hypertension

Introduction

Pulmonary arterial hypertension secondary to congenital heart disease (CHD-PAH) with systemic-to-pulmonary shunt is characterized by proliferative vascular remodeling. Excessive proliferation and resistance to apoptosis of pulmonary artery smooth muscle cells (PASMCs) are the primary cellular bases of vascular remodeling. Anthrax toxin receptor 2 (ANTXR2) exhibits anti-proliferative properties. The effects of ANTXR2 on vascular remodeling and systemic-to-pulmonary shunt induced PAH remain unexplored.

Purpose

The purpose of this study was to determine the possible roles of ANTXR2 in the pathogenesis of systemic-to-pulmonary shunt induced PAH and explore its possible mechanisms.

Methods

Lung tissue sections from CHD-PAH patients, systemic-to-pulmonary shunt induced PAH rat model, ANTXR2−/− rats, and PASMCs were used. Immunohistochemistry, real time polymerase chain reaction, Western blot, proliferation, apoptosis, and next generation sequencing (NGS) were performed in this study.

Results

ANTXR2 expression was reduced in severe CHD-PAH patient lung tissue and pulmonary arterioles, as well as in lung tissues from rats with systemic-to-pulmonary shunt induced PAH. Over-expression of ANTXR2 in cultured PASMCs inhibited cell proliferation and promoted apoptosis, while knockdown of ANTXR2 promoted cell proliferation and inhibited apoptosis. Male ANTXR2−/− rats showed more severe percent medial thickness and muscularization of pulmonary arterioles than wild type (WT) rats in basal conditions, and exhibited heavier PAH following exposure to systemic-to-pulmonary shunt. To further determine the underling mechanism, NGS was performed in ANTXR2−/− rat lungs and that of WT littermates. A total of 1319 genes were found to be dysregulated, and biological processes influenced by these differentially expressed genes include negative regulation of blood vessel diameter,vasoconstriction, regulation of blood vessel diameter, regulation of blood vessel size, vascular process in circulatory system, etc.

Conclusion

Our work identifies a novel role for ANTXR2 in systemic-to-pulmonary shunt induced PAH based on the findings that ANTXR2 deficiency could exacerbate systemic-to- pulmonary shunt induced vascular remodeling in the development of PAH. ANTXR2 may be a potential target for CHD-PAH treatment.

Acknowledgement/Funding

Beijing Natural Science Foundation (7172078 and 7172182), the National Major Research Plan Training Program of China (91849111)

[The impact of different doses of atorvastatin on plasma endothelin and platelet function in acute ST-segment elevation myocardial infarction after emergency percutaneous coronary intervention]

Objective: To investigate the effects of different doses of atorvastatin on plasma endothelin and platelet function in acute ST-segment elevation myocardial infarction (STEMI) patients after emergency percutaneous coronary intervention(PCI). Methods: A total of 120 patients with acute STEMI treated with emergency PCI were enrolled and randomly divided into 20 mg of atorvastatin treatment group (standard group, n=60), and 40 mg of atorvastatin treatment group (intensive group, n=60). The blood C reactive protein (CRP), blood lipid profiles, plasma endothelin (ET) were measured before atorvastatin treatment and after 7 days of treatment, respectively. The platelet fibrin clot strength induced by ADP (MAADP) was determined by thrombelastography(TEG). Results: Seven days after of atorvastatin treatment, the level of plasma ET in intensive group was significantly lower than that in standard group [(0.49±0.21)pmol/L vs (0.63±0.58)pmol/L, P<0.05]. Moreover, the MAADP in intensive group was significantly decreased compared with the standard group [(38.4±17.4) mm vs (45.7±14.5) mm, P<0.05]. There was a positive correlation between the ET level and MAADP in intensive group after treatment (r=0.378, P<0.05). However, no significantly differences could be viewed in the CRP and LDL-C levels between the two groups (P>0.05). Conclusion: In patients with acute STEMI, early administration of 40 mg atorvastatin after emergency PCI could significantly reduce the vascular endothelial injury, improve endothelial function, and reduce the residual platelet activity.

[Application of low dose CT angiography with 70 kV in patients with peripheral arterial diseases]

Objective: To assess the image quality, radiation dose and diagnostic efficiency of peripheral arterial CT angiography (CTA) performed at tube voltage of 70 and 120 kV. Methods: Between January 2014 and December 2015, a total of 200 consecutive patients with known or suspected lower extremity arteriosclerosis obliterans (LEASO) underwent CTA.Patients were randomly divided into 2 groups by different scanning protocols.Group A (n=100): 70 kV and 0.8 ml/kg contrast agent, group B (n=100): 120 kV and 100 ml contrast agent.The vessel enhancement, image noise, signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR) of 3 segments were quantified for each protocol.30 patients in group A (420 vessels) and 28 patients in group B (384 vessels) confirmed by DSA.Based on vessel assessments, compared with DSA findings, the diagnostic efficacy of 70 kV and 120 kV protocols for the detection of stenoses over 50% was evaluated.The dose of radiation and contrast agent were recorded.Subjective image quality was evaluated. Results: The subjective image quality of segment crural of group A was significantly higher than that of group B (2.20±0.36 vs 1.72±0.34, P<0.01). The enhancement of 3 segments in group A (500 HU) were significantly higher than these in group B (310 HU) (P<0.05). For the detection of stenoses over 50%, the sensitivity, positive and negative predictive values and accuracy of segment crural in group A (98.6%, 95.8%, 98.1%, 96.7%) were significantly higher than that in group B (90.9%, 88.5%, 91.0%, 89.7%) (P<0.05). Mean DLP for 70-kV protocol was significantly lower than that for 120-kV protocol ( (396±34) vs (1 041±159) mGy·cm, P=0.001). Mean dose of contrast agent and the total amount of iodine for 70-kV protocol were significantly lower than that for 120-kV protocol (53.5 vs 100 ml; 18.7 vs 35 g; P<0.01). Conclusion: CT angiography of peripheral arteries with a low tube voltage of 70 kV and low dose of iodine provides reliable information and serves as a rapidly performed and easily available imaging modality in the diagnosis of LEASO.

Serum levels of PSA, ALP, ICTP, and BSP in prostate cancer patients and the significance of ROC curve in the diagnosis of prostate cancer bone metastases

Bone metastasis is a common complication in prostate cancer patients that can cause bone pain and pathological fracture. This study tested serum levels of prostate specific antigen (PSA), alkaline phosphatase (ALP), bone sialoprotein (BSP), collagen type I pyridine crosslinking peptide (ICTP) in prostate cancer patients and the significance of the receiver operator characteristic (ROC) curve in the diagnosis of prostate cancer bone metastases. Eighty-three prostate cancer patients were enrolled including 42 in the bone metastases group and 41 in the non-bone metastases group. Serum levels of BSP, ALP, ICTP, and PSA were highest in the bone metastases group followed by the non-bone metastases group, hyperplasia group, and then the control group (P < 0.05). Based on Gleason score, serum levels were highest in the poorly differentiated group followed by moderately differentiated and well-differentiated groups (P < 0.05). ROC curve analysis revealed that the diagnostic efficiency of the biomarkers in turn was BSP, PSA, ICTP, and ALP. The sensitivity of BSP, ALP, ICTP, and PSA in the diagnosis of prostate cancer bone metastases were 80.95, 57.14, 69.05, 71.43%, respectively, and the specificity of the same markers were 72.80, 64.80, 76.80, and 88.80%, respectively. Combined detection of the four markers improved sensitivity to 97.62% and the negative-predictive value increased to 97.60%. PSA + BSP showed the best efficiency when combining two markers. In conclusion, serum levels of BSP, ALP, ICTP, and PSA increased in patients with bone metastases, and combined detection of all markers could improve the positive-predictive value.

Differentiating origins of outflow tract ventricular arrhythmias: a comparison of three different electrocardiographic algorithms

Our objective is to evaluate the accuracy of three algorithms in differentiating the origins of outflow tract ventricular arrhythmias (OTVAs). This study involved 110 consecutive patients with OTVAs for whom a standard 12-lead surface electrocardiogram (ECG) showed typical left bundle branch block morphology with an inferior axis. All the ECG tracings were retrospectively analyzed using the following three recently published ECG algorithms: 1) the transitional zone (TZ) index, 2) the V₂ transition ratio, and 3) V₂ R wave duration and R/S wave amplitude indices. Considering all patients, the V₂ transition ratio had the highest sensitivity (92.3%), while the R wave duration and R/S wave amplitude indices in V₂ had the highest specificity (93.9%). The latter finding had a maximal area under the ROC curve of 0.925. In patients with left ventricular (LV) rotation, the V₂ transition ratio had the highest sensitivity (94.1%), while the R wave duration and R/S wave amplitude indices in V₂ had the highest specificity (87.5%). The former finding had a maximal area under the ROC curve of 0.892. All three published ECG algorithms are effective in differentiating the origin of OTVAs, while the V₂ transition ratio, and the V₂ R wave duration and R/S wave amplitude indices are the most sensitive and specific algorithms, respectively. Amongst all of the patients, the V₂ R wave duration and R/S wave amplitude algorithm had the maximal area under the ROC curve, but in patients with LV rotation the V₂ transition ratio algorithm had the maximum area under the ROC curve.

[The effect and safety of tirofiban on acute ST segment elevation myocardial infarction patients receiving no early reperfusion therapy]

OBJECTIVE

To study the efficacy and safety of tirofiban on acute ST segment elevation myocardial infarction (STEMI) in patients who do not receive early reperfusion therapy.

METHODS

A total of 153 STEMI patients without early reperfusion therapy were randomly distributed into tirofiban group (therapeutic group, n=78) and non-tirofiban group (control group, n=75). Coronary angiography was performed on the 5(th) and 10(th) day after treatment, and percutaneous coronary intervention (PCI) was conducted when necessary. The differences of initial patency of the infarct related artery (IRA), bleeding complication and clinic events within 30 days between these two groups were compared.

RESULTS

Tirofiban did not increase the percentage of patients with initial patency of IRA (60.3% vs 64.0%, P=0.63). The percentage of patients with thrombolysis in myocardial infarction (TIMI) 3 after PCI was 100.0% in tirofiban group and 97.1% in the control group (P=0.09). However, application of tirofiban significantly decreased poor myocardial perfusion rate after PCI (1.4% vs 8.8%, P=0.04). No significant differences were observed in major adverse cardiovascular events (MACE) (3.8% vs 2.7%, P=0.68) between therapeutic and control group. The same is true for mild (5/78 vs 4/75 cases, P=0.78) and severe hemorrhage (2/78 vs 1/75 cases, P=0.58), and severe thrombocytopenia (2/78 vs 0/75 cases, P=0.10) between these two groups within 30 days.

CONCLUSIONS

Tirofiban did not increase initial patency in STEMI patients without early reperfusion therapy. However, it can improve myocardial perfusion after PCI.

Ginkgo biloba extract for essential hypertension: a systemic review

BACKGROUND

Ginkgo biloba extract (GBE), a traditional natural herbal product, is often used in the treatment of essential hypertension (EH) as complementary therapy in China and European countries.

AIM

To critically assess the current clinical evidence of efficacy and safety of GBE for EH.

METHODS

7 electronic databases (Cochrane Library, PubMed, EMBASE, VIP, CBM, Wanfang data, and CNKI) were searched to identify randomized controlled trials (RCTs) of GBE for EH. Methodological quality was assessed independently using the Cochrane Handbook for Systematic Reviews of Interventions.

RESULTS

A total of 9 RCTs with 1012 hypertensive patients were identified and reviewed. Most RCTs were of high risk of bias with flawed study design and poor methodological quality. 6 trials demonstrated potential positive effect of GBE as complementary therapy on BP reduction when compared with antihypertensive drug therapy; however, it was not associated with a statistically significant effect on both SBP and DBP reduction in 3 other trials. Despite the positive findings, there were so many methodological limitations and significant clinical heterogeneity. Most of the trials did not report adverse effects, and the safety of GBE is still uncertain.

CONCLUSION

No confirmative conclusions on the efficacy and safety of GBE for EH could be drawn. More rigorous trials are warranted to support their clinical use.

Adenovirus-mediated siRNA targeting TNF-α and overexpression of bone morphogenetic protein-2 promotes early osteoblast differentiation on a cell model of Ti particle-induced inflammatory response in vitro

Wear particles are phagocytosed by macrophages and other inflammatory cells, resulting in cellular activation and release of proinflammatory factors, which cause periprosthetic osteolysis and subsequent aseptic loosening, the most common causes of total joint arthroplasty failure. During this pathological process, tumor necrosis factor-alpha (TNF-α) plays an important role in wear-particle-induced osteolysis. In this study, recombination adenovirus (Ad) vectors carrying both target genes [TNF-α small interfering RNA (TNF-α-siRNA) and bone morphogenetic protein 2 (BMP-2)] were synthesized and transfected into RAW264.7 macrophages and pro-osteoblastic MC3T3-E1 cells, respectively. The target gene BMP-2, expressed on pro-osteoblastic MC3T3-E1 cells and silenced by the TNF-α gene on cells, was treated with titanium (Ti) particles that were assessed by real-time PCR and Western blot. We showed that recombinant adenovirus (Ad-siTNFα-BMP-2) can induce osteoblast differentiation when treated with conditioned medium (CM) containing RAW264.7 macrophages challenged with a combination of Ti particles and Ad-siTNFα-BMP-2 (Ti-ad CM) assessed by alkaline phosphatase activity. The receptor activator of nuclear factor-κB ligand was downregulated in pro-osteoblastic MC3T3-E1 cells treated with Ti-ad CM in comparison with conditioned medium of RAW264.7 macrophages challenged with Ti particles (Ti CM). We suggest that Ad-siTNFα-BMP-2 induced osteoblast differentiation and inhibited osteoclastogenesis on a cell model of a Ti particle-induced inflammatory response, which may provide a novel approach for the treatment of periprosthetic osteolysis.

What do we (not) know about how paracetamol (acetaminophen) works?

WHAT IS KNOWN AND BACKGROUND

Although paracetamol (acetaminophen), N-(4-Hydroxyphenyl)acetamide, is one of the world's most widely used analgesics, the mechanism by which it produces its analgesic effect is largely unknown. This lack is relevant because: (i) optimal pain treatment matches the analgesic mechanism to the (patho)physiology of the pain and (ii) modern drug discovery relies on an appropriate screening assay.

OBJECTIVE

To review the clinical profile and preclinical studies of paracetamol as means of gaining insight into its mechanism of analgesic action.

METHODS

A literature search was conducted of clinical and preclinical literature and the information obtained was organized and reviewed from the perspective of its contribution to an understanding of the mechanism of analgesic action of paracetamol.

RESULTS

Paracetamol's broad spectrum of analgesic and other pharmacological actions is presented, along with its multiple postulated mechanism(s) of action. No one mechanism has been definitively shown to account for its analgesic activity.

WHAT IS NEW AND CONCLUSION

Further research is needed to uncover the mechanism of analgesic action of paracetamol. The lack of this knowledge affects optimal clinical use and impedes drug discovery efforts.

Investigation of optimal aminolaevulinic acid concentration applied in topical aminolaevulinic acid-photodynamic therapy for treatment of moderate to severe acne: a pilot study in Chinese subjects

BACKGROUND

Aminolaevulinic acid-photodynamic therapy (ALA-PDT) is a novel and effective treatment in acne. However, little is known about the effect of different concentrations of ALA in the treatment of acne in Chinese patients with Fitzpatrick skin type III and IV.

OBJECTIVES

To investigate the efficacy and safety of ALA-PDT in the treatment of moderate to severe acne in Chinese patients and to identify the suitable concentration of topical ALA.

METHODS

One hundred and eighty patients with moderate to severe facial acne were recruited and randomly divided into four groups. Each group was treated with a different concentration (5%, 10%, 15% and 20%) of ALA to the facial lesions on the right side and placebo agent on the left side as control. Each patient was treated once every 10 days for four sessions. The numbers of inflammatory and noninflammatory acne lesions were counted at baseline and at weeks 2, 4, 12 and 24 after the last treatment. Adverse effects were recorded at each follow-up visit.

RESULTS

After 24 weeks, each side treated by ALA-PDT showed clinical improvement compared with the control side treated by red light alone (P < 0·01). Statistically significantly more patients treated with 20% ALA than with 15% or 10% ALA achieved complete clearance. Regarding side-effects, a trend towards more serious erythema and pigmentation was observed with increasing ALA concentration.

CONCLUSIONS

Increasing the concentration of ALA seems to be beneficial for improving the results. Considering effectiveness and safety, ALA-PDT using 10% or 15% ALA is suggested to the ideal treatment for moderate to severe acne in Chinese patients with Fitzpatrick skin type III and IV.

Silver structure environments in ion-exchanged silicate glasses studied by X-ray absorption fine structure

X-ray absorption fine structure (XAFS) technique was used to analyze structural geometry of Ag atoms introduced into soda-lime silicate glass and soda aluminosilicate glass by ion-exchange method. The results show that Ag+ ion in soda aluminosilicate glass takes a coordination number of 1.6 with a Ag-O distance of 2.20 A when the ion-exchange ratio x is smaller than 0.47 and of 2.28 A when x is larger than 0.47. The introduced Ag+ ions are stabilized at the non-bridge oxygen (NBO) sites when x is lower than 0.47. The Na+ ions in AlO4 (O4 represents the bridging oxygen) sites are exchanged by Ag+ ions after all Na+ in NBO sites are replaced. The disorder of Ag-O coordination increases gradually with increasing x from 0.24 to 0.47 in soda aluminosilicate glass and increases dramatically when x is larger than 0.47. Ag+ ions takes a coordination number of 1.6 in the ion-exchanged soda-lime silicate glass and of 1.3 after subsequently thermal treatment with the same Ag-O distance of 2.14 A. Debye-Waller factor (DWF) of Ag-O coordination in soda aluminosilicate glass is higher than that in soda-lime silicate glass. Small Ag cluster has a reduced interatomic distance and a larger DWF. Ag nanoparticle in sample Ag-7 is in a state of tensile stress.

In-line fiber-optic etalon formed by hollow-core photonic crystal fiber

A novel fiber-optic in-line etalon formed by splicing a section of hollow-core photonic crystal fiber (HCPCF) in between two single-mode fibers is proposed and demonstrated, for the first time to our knowledge. Such a HCPCF-based etalon acts as an excellent optical waveguide to form a Fabry-Perot interferometer and hence allows the cavity length to be as long as several centimeters with good visibility as the transmission loss of the HCPCF is much smaller than that of a hollow core fiber; this offers great potential to generate a practical dense fiber-optic sensor network with spatial frequency division-multiplexing. This novel etalon is demonstrated for strain measurement, and the experimental results show that a good visibility of 0.3 and a strain accuracy of better than +/- 5 microepsilon are achieved.

Hybrid processing and time-frequency analysis of ECG signal

A new simple approach basing on the histogram and genetic algorithm(GA) to efficiently detect QRS-T complexes of the ECG curve is described, so as to easily get the P-wave (when AF does not happen) or the f-wave (when AF happens). By means of signal processing techniques such as the power spectrum function, the auto-correlation function and cross-correlation function, two kinds of ECG signal when AF does or does not happen were successively analyzed, showing the evident differences between them.

Anisotropy and Corotation of Galactic Cosmic Rays

The intensity of Galactic cosmic rays is nearly isotropic because of the influence of magnetic fields in the Milky Way. Here, we present two-dimensional high-precision anisotropy measurement for energies from a few to several hundred teraelectronvolts (TeV), using the large data sample of the Tibet Air Shower Arrays. Besides revealing finer details of the known anisotropies, a new component of Galactic cosmic ray anisotropy in sidereal time is uncovered around the Cygnus region direction. For cosmic-ray energies up to a few hundred TeV, all components of anisotropies fade away, showing a corotation of Galactic cosmic rays with the local Galactic magnetic environment. These results have broad implications for a comprehensive understanding of cosmic rays, supernovae, magnetic fields, and heliospheric and Galactic dynamic environments.

Observation by an air-shower array in Tibet of the multi-TeV cosmic-ray anisotropy due to terrestrial orbital motion around the Sun

We report on the solar diurnal variation of the galactic cosmic-ray intensity observed by the Tibet III air shower array during the period from 1999 to 2003. In the higher-energy event samples (12 and 6.2 TeV), the variations are fairly consistent with the Compton-Getting anisotropy due to the terrestrial orbital motion around the Sun, while the variation in the lower-energy event sample (4.0 TeV) is inconsistent with this anisotropy. This suggests an additional anisotropy superposed at the multi-TeV energies, e.g., the solar modulation effect. This is the highest-precision measurement of the Compton-Getting anisotropy ever made.

[Surveillance of filariasis in some vulnerable areas in Guangxi after filariasis elimination]

OBJECTIVE

To explore the measures for continuing surveillance of filariasis.

METHODS

Selecting some vulnerable spots for focal surveillance, double-slide biood sampling for microfilaria examination, dissecting vectors for detecting the mosquitoes infected with filarial larva, using IFAT for detecting antifilarial antibody.

RESULTS

27,938 persons were examined for microfilaria and 4,454 mosquitoes were dissected for filaria larva, all were negative. 3,606 serum samples were examined for antifilarial antibody average positive rate was 1.35%(0.39-4.97%).

CONCLUSION

The results of surveillance showed that the achievement of filariasis control in Guangxi after filariasis elimination is consolidated.

[Cloning, sequence analysis and high-level expression in Escherichia coli and activity assay of pac-1 gene from Schizosaccharmyces pombe]

The Schizosaccharmyces pombe pac-1 gene product is a kind of dsRNA dependent ribonuclease, which has potential to degrade the dsRNA viral genome, the replication form of ssRNA viral genome and viroid genome. Therefore, to introduce the pac-1 gene into plants conferring them resistance to viruses is a new method of establishing the anti-virus transgenic plant. The pac-1 gene from the S. pmobe genome DNA isolated from China was cloned by means of PCR amplification. The pac-1 gene was inserted into the cloning vector pGEM-7Zf(+) by using restriction endonuclease Kpn I/BamHI. Sequencing analysis shows that it is a complete gene with 1095 necleotides. Compared to the reported pac-1 gene, its homology is significant, but with 5 nucleotides differences, leading to only one amino acid difference. Pac-1 gene was inserted into the prodaryotic expression vector pET-21(a) by using the restriction endonuclase Nde I/BamHI. It was induced by the IPTG in E. coli BL21 harbouring the recombinant vector pET-pac-1. The pac-1 gene product is analyzed by the SDS-PAGE. The result shows the product of pac-1 gene exists in the supernatant part as soluble form and in the precipitant part as inclusion bodies after the cells were lysed by ultrasonic wave. The supernatant was applied to detect the enzyme activity of pac-1 gene product. We concluded that pac-1 gene has the biological activity of degrading the CMV-dsRNA.

Agmatine selectively blocks the N-methyl-D-aspartate subclass of glutamate receptor channels in rat hippocampal neurons

We investigated in rat hippocampus neurons whether 4-(aminobutyl)guanidine (agmatine), formed by decarboxylation of L-arginine by arginine decarboxylase and metabolized to urea and putrescine, can modulate the function of N-methyl-D-aspartate (NMDA) receptor channels. In cultured hippocampal neurons studied by whole-cell patch clamp, extracellular-applied agmatine produced a voltage- and concentration-dependent block of NMDA but not alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid nor kainate currents. Analysis of the voltage dependence of the block suggests that agmatine binds at a site located within the NMDA channel pore with a dissociation constant of 952 microM at 0 mV and an electric distance of 0.62. We also tested effects of several agmatine analogs. Arcaine (1,4-butyldiguanidine) also produced a similar voltage-dependent block of the NMDA current, whereas putrescine (1, 4-butyldiamine) had little effect, suggesting that the guanidine group of agmatine is the active moiety when blocking the NMDA channel. Moreover, spermine (an endogenous polyamine) potentiated the NMDA current even in the presence of blocker agmatine or arcaine, suggesting that the guanidine-containing compounds agmatine and arcaine interact with the NMDA channel at a binding site different from that of spermine. Our results indicate that in hippocampal neurons agmatine selectively modulates the NMDA subclass of glutamate receptor channels mediated by the interaction between the guanidine group and the channel pore. The results support other data that agmatine may function as an endogenous neurotransmitter/neuromodulator in brain.

Agmatine containing axon terminals in rat hippocampus form synapses on pyramidal cells

We examined the cellular and subcellular localization of agmatine in the hippocampal CA1 region by immunocytochemistry. By light microscopy, agmatine-like immunoreactivity (agmatine-LI) was found primarily in the perikarya and dendritic profiles of pyramidal cells and in punctate processes preponderantly in stratum radiatum. Electron microscopy revealed that agmatine-LI was cytoplasmic and concentrated in 'clusters' associated with mitochondria and tubular vesicles. In stratum radiatum, agmatine-LI was primarily in axons and axon terminals associated with small, synaptic vesicles. The terminals almost exclusively formed asymmetric synapses on the spines of dendrites, many of which originated from pyramidal cells. Some agmatine-LI also was present in shafts and spines of pyramidal cell dendrites and in astrocytic processes. The results demonstrate that agmatine in the hippocampus is found primarily in terminals forming excitatory (asymmetric) synapses on pyramidal cells, some of which contain agmatine-LI. These findings further implicate agmatine as an endogenous neurotransmitter which may be co-stored with L-glutamate and may act in part in the rat hippocampus as a blocker of the N-methyl-D-aspartate receptor and nitric oxide synthase.

Cloning, localization, and functional expression of a human brain inward rectifier potassium channel (hIRK1)

We have cloned a novel human brain inward rectifier K+ channel (hIRK1), which shares approximately 60% amino acid identity with another human inward rectifier (hIRK2) but 98% identity with the mouse IRK1. The hIRK1 mRNA is expressed in several human tissues: skeletal muscle > placenta > heart > brain > lung > kidney. In human brain, the hIRK1 mRNA is uniformly distributed (except for a higher level in the corpus callosum, which contains white matter and glial cells), whereas the hIRK2 mRNA is expressed in major regions of the basal ganglia and limbic system. Xenopus oocytes injected with hIRK1 cRNA expressed an inwardly rectifying K+ current that was blocked by extracellular Ba2+. The hIRK1 channel carried a significant outward current when membrane potential was more positive than the K+ equilibrium potential (EK) and therefore had an "N-shape" current-voltage relation, resembling that of the native cardiac IRK channel. The resting membrane potential was near EK in oocytes expressing hIRK1, but was approximately -40 mV in H2O-injected or non-injected oocytes. The ability of hIRK1 to set the resting membrane potential depended on the outward current. Single-channel conductance of hIRK1 was 32 pS measured with 150 mM KCl in the patch pipette, significantly higher than 23 pS measured for mouse IRK1 and approximately 10 pS for hIRK2.

Cloning a novel human brain inward rectifier potassium channel and its functional expression in Xenopus oocytes

We have cloned a novel inward rectifier K+ channel (hIRK2) from a human frontal cortex cDNA library. The amino acid sequence of hIRK2 shares 60% and 40% identity with the mouse IRK1 and the rat ROMK1 channels, respectively. Xenopus oocytes injected with hIRK2 cRNA showed an inwardly rectifying K+ current that had a prominent 'N-shape' I-V curve and was blocked by extracellular Ba2+. The hIRK2 channel has two unique features: (a) an 18 amino acid insertion between the first transmembrane region and the pore, and (b) restricted mRNA distribution found only in human brain and heart.

[Preoperative selective intraarterial chemotherapy combined with gastrectomy in the treatment of gastric carcinoma]

In this study, 19 cases of gastric carcinoma were treated by selective intraarterial chemotherapy before surgical resection. Pathological examination of the resected specimen found that the effective rate of this selective chemotherapy was 89%. The survival rate of 6 months, 1 year, 2 years, and 3 years was 100%, 90%, 87%, and 83%, respectively.

Slow and incomplete inactivations of voltage-gated channels dominate encoding in synthetic neurons

Electrically excitable channels were expressed in Chinese hamster ovary cells using a vaccinia virus vector system. In cells expressing rat brain IIA Na+ channels only, brief pulses (< 1 ms) of depolarizing current resulted in action potentials with a prolonged (0.5-3 s) depolarizing plateau; this plateau was caused by slow and incomplete Na+ channel inactivation. In cells expressing both Na+ and Drosophila Shaker H4 transient K+ channels, there were neuron-like action potentials. In cells with appropriate Na+/K+ current ratios, maintaining stimulation produced repetitive firing over a 10-fold range of frequencies but eventually led to "lock-up" of the potential at a positive value after several seconds of stimulation. The latter effect was due primarily to slow inactivation of the K+ currents. Numerical simulations of modified Hodgkin-Huxley equations describing these currents, using parameters from voltage-clamp kinetics studied in the same cells, accounted for most features of the voltage trajectories. The present study shows that insights into the mechanisms for generating action potentials and trains of action potentials in real excitable cells can be obtained from the analysis of synthetic excitable cells that express a controlled repertoire of ion channels.

Relation of hemostatic risk factors to other risk factors for coronary heart disease and to sex hormones in men

The present study was carried out to explore the possible relation of plasma plasminogen activator inhibitor-1 (PAI-1), fibrinogen, and factor VII levels to other risk factors for coronary heart disease (CHD) and to serum sex hormone levels. The study group comprised 48 apparently healthy men. To avoid the confounding factor of obesity, correlations were determined in the 30 men in this group with a body mass index (BMI) < 26.4, after controlling for age. PAI-1 correlated with testosterone, estradiol/testosterone, and free testosterone/testosterone (FT/T), and fibrinogen correlated with FT/T. All three hemostatic factors correlated with glucose and with the ratio of cholesterol/high density lipoprotein cholesterol, while PAI-1 correlated with diastolic blood pressure. To test the effect of obesity, correlations were determined in the entire group of 48 men, which included 18 subjects with a BMI > 26.4. All three hemostatic factors correlated with BMI in this group after controlling for age; however, on controlling for testosterone, only PAI-1 correlated with BMI. Fibrinogen correlated with age in both groups after controlling for testosterone or BMI. These correlations support the hypothesis that PAI-1, fibrinogen, and factor VII are related to other risk factors for CHD and that an alteration in the sex hormone milieu may be the underlying factor linking them.

Mechanically sensitive, nonselective cation channels

Mechanically sensitive channels (MSCs) are ubiquitous in plant and animal cells. They respond primarily to membrane tension, thus making them good transducers for forces derived from osmotic or hydraulic gradients and shear stress. They may also be modulated by membrane voltage and various ligands. MSCs are most commonly cation selective, passing calcium as well as monovalent ions, but some are K+ selective, and a few are anion selective. MSCs occur at a density of about 0.2-5 per microns2. The universal distribution and biophysical properties of MSCs make them the ideal mechanotransducers in a wide variety of cellular processes.

Cell-specific posttranslational events affect functional expression at the plasma membrane but not tetrodotoxin sensitivity of the rat brain IIA sodium channel alpha-subunit expressed in mammalian cells

The rat brain IIA Na+ channel alpha-subunit was expressed and studied in mammalian cells. Cells were infected with a recombinant vaccinia virus (VV) carrying the bacteriophage T7 RNA polymerase gene and were transfected with cDNA encoding the IIA Na+ channel alpha-subunit under control of a T7 promoter. Whole-cell patch-clamp recording showed that functional IIA channels were expressed efficiently (approximately 10 channels/microns2 in approximately 60% of cells) in Chinese hamster ovary (CHO) cells and in neonatal rat ventricular myocytes but were expressed poorly in undifferentiated BC3H1 cells and failed to express in Ltk- cells. However, voltage-dependent Drosophila Shaker H4 K+ channels and Escherichia coli beta-galactosidase were expressed efficiently in all four cell types with VV vectors. Because RNA synthesis probably occurs without major differences in the cytoplasm of all infected cell types under the control of the T7 promoter and T7 polymerase, we conclude that cell type-specific expression of the Na+ channel probably reflects differences at posttranslational steps. The gating properties of the IIA Na+ currents expressed in cardiac myocytes differed from those expressed in CHO cells; most noticeably, the IIA Na+ currents displayed more rapid macroscopic inactivation when expressed in cardiac myocytes. These differences also suggest cell-specific posttranslational modifications. IIA channels were blocked by approximately 90% by 90 nM TTX when expressed either in CHO cells or in cardiac myocytes; the latter also continued to display endogenous TTX-resistant Na+ currents. Therefore, the TTX binding site of the channel is not affected by cell-specific modifications and is encoded by the primary amino acid sequence.