Ablation of endothelial prolyl hydroxylase domain protein-2 promotes renal vascular remodelling and fibrosis in mice.

Accumulating evidence demonstrates that hypoxia-inducible factor (HIF-α) hydroxylase system has a critical role in vascular remodelling. Using an endothelial-specific prolyl hydroxylase domain protein-2 (PHD2) knockout (PHD2EC KO) mouse model, this study investigates the regulatory role of endothelial HIF-α hydroxylase system in the development of renal fibrosis. Knockout of PHD2 in EC up-regulated the expression of HIF-1α and HIF-2α, resulting in a significant decline of renal function as evidenced by elevated levels of serum creatinine. Deletion of PHD2 increased the expression of Notch3 and transforming growth factor (TGF-ß1) in EC, thus further causing glomerular arteriolar remodelling with an increased pericyte and pericyte coverage. This was accompanied by a significant elevation of renal resistive index (RI). Moreover, knockout of PHD2 in EC up-regulated the expression of fibroblast-specific protein-1 (FSP-1) and increased interstitial fibrosis in the kidney. These alterations were strongly associated with up-regulation of Notch3 and TGF-ß1. We concluded that the expression of PHD2 in endothelial cells plays a critical role in renal fibrosis and vascular remodelling in adult mice. Furthermore, these changes were strongly associated with up-regulation of Notch3/TGF-ß1 signalling and excessive pericyte coverage.

Role of PERK/eIF2α/CHOP Endoplasmic Reticulum Stress Pathway in Oxidized Low-density Lipoprotein Mediated Induction of Endothelial Apoptosis.

OBJECTIVE: PERK/eIF2α/CHOP is a major signaling pathway mediating endoplasmic reticulum (ER) stress related with atherosclerosis. Oxidized LDL (ox-LDL) also induces endothelial apoptosis and plays a vital role in the initiation and progression of atherosclerosis. The present study was conducted to explore the regulatory effect of ox-LDL on PERK/eIF2α/CHOP signaling pathway in vascular endothelial cells. METHODS: The effects of ox-LDL on PERK and p-eIF2α protein expression of primary human umbilical vein endothelial cells (HUVECs) were investigated by Western blot analysis. PERK gene silencing and selective eIF2α phosphatase inhibitor, salubrinal were used to inhibit the process of ox-LDL induced endothelial cell apoptosis, caspase-3 activity, and CHOP mRNA level. RESULTS: Ox-LDL treatment significantly increased the expression of PERK, PERK-mediated inactivation of eIF2α phosphorylation, and the expression of CHOP, as well as the caspase-3 activity and apoptosis. The effects of ox-LDL were markedly decreased by knocking down PERK with stable transduction of lentiviral shRNA or by selective eIF2α phosphatase inhibitor, salubrinal. CONCLUSION: This study provides the first evidence that ox-LDL induces apoptosis in vascular endothelial cells mediated largely via the PERK/eIF2α/CHOP ER-stress pathway. It adds new insights into the molecular mechanisms underlying the pathogenesis and progression of atherosclerosis.

Lung ultrasonography: an effective way to diagnose community-acquired pneumonia.

PURPOSE: To analyse the ultrasonographic findings of community-acquired pneumonia (CAP) and its efficacy for diagnosis of CAP compared with chest X-ray (CXR). METHODS: Patients who presented to the Emergency Department with suspected CAP were included in the study. Bedside ultrasonography was performed at each intercostal space in the midclavicular, anterior axillary, midaxillary and paravertebral lines. Any pulmonary consolidation, focal interstitial pattern, pleural-line abnormalities and subpleural lesions were recorded, and the numbers of subpleural lesions and intercostal spaces with pleural-line abnormalities were counted. All patients received bedside CXR and CT. Using CT scan as the gold standard, ultrasonography findings were compared between CAP group and non-CAP group, and between CAP patients with CT showing consolidation or diffuse ground-glass opacification. The sensitivity of ultrasonography was compared with CXR for the diagnosis of CAP. RESULTS: Of 179 patients included in the study, 112 were diagnosed with CAP by CT. Patients in CAP group were more likely to have consolidation (p<0.001), focal interstitial pattern (p<0.001) and had higher number of subpleural lesions (p<0.001) and intercostal spaces with pleural-line abnormalities (p<0.001) on ultrasound than those without CAP. CAP patients whose CT showed consolidation were more likely to have consolidation (p<0.001) and had lower numbers of subpleural lesions (p<0.001) and intercostal spaces with pleural-line abnormalities (p<0.001) compared to CAP patients whose CT showed diffuse ground-glass opacification. The diagnostic sensitivity, specificity, and accuracy for ultrasonography and CXR were 94.6% versus 77.7% (p<0.001), 98.5% versus 94.0% (p=0.940) and 96.1% versus 83.8% (p<0.001), respectively. CONCLUSIONS: Lung ultrasonography has a better diagnostic sensitivity and accuracy for diagnosing CAP compared with CXR.

Incidence and associated factors for single and recurrent falls among the elderly in an urban community of Beijing.

OBJECTIVE: To investigate the incidence of falls and recurrent falls, and explore associated factors for single and recurrent falls among urban community-dwelling elderly in Beijing. METHODS: A cross-sectional study was conducted in 472 elderly in the Longtan community of Dongcheng district, Beijing in 2009. Data regarding the incidence of fall and recurrent falls in the previous year, as well as associated factors were collected from the elderly through face-to-face interviews. RESULTS: The incidence of falls and recurrent falls was 17.8% and 6.1%, respectively, and it increased with age (χ2for trend=21.06, 19.20, P=0.001, 0.002). Binary logistic stepwise regression analysis showed that age (OR=2.20), living alone (OR=4.67) and gait disturbance (OR=1.27) were risk factors, while housing with elevators (OR=0.35), appropriate width/height of stair steps (OR=0.78), sufficient lighting for stairway (OR=0.45) and regular exercise (OR=0.12) could lower the risk for single fall; factors such as low monthly family income (OR=1.39), poor vision (OR=1.83), low physical ability (OR=4.47), abnormal static balance (OR=2.48), and fear of falls(OR=2.23) were risk factors, while appropriate width/height of stair steps (OR=0.49) and easiness of access to daily supplies (OR=0.41) were protective factors for recurrent falls. CONCLUSION: The incidence of falls in community-dwelling elderly people in Beijing is common, and falls and their related injuries have been associated with both intrinsic and extrinsic factors.

Elevated platelet activating factor level in ischemia-related arrhythmia and its electrophysiological effect on myocardium.

OBJECTIVE: The mechanism through which platelet activating factor (PAF) induces cardiac electrical activity and arrhythmia is not well understood and previous studies have suggested a potential involvement of ion channels in its action. The present study was aimed to clarify the role of PAF in fatal arrhythmias following acute myocardia infarction (AMI) and the underlying mechanism. METHODS: (1) Blood PAF levels were measured among 72 AMI patients at the time of diagnosis with AMI and 48 h later, and their electrocardiogram (ECG) was recorded continuously. (2) Ischemia simulation and surface electrocardiogram were conducted in 20 pigs and their PAF levels were measured. (3) PAF perfusion and standard microelectrode recording were performed on guinea pig papillary muscles. RESULTS: In both humans and pigs, elevated PAF levels were detected in AMI and simulated ischemia, respectively, and even higher PAF levels were found when fatal arrhythmias occurred. In guinea pig myocardium, PAF induced a shortening of action potential duration at 90% level of repolarization (APD90)under non-ischemic conditions and a more pronounced shortening under early simulated ischemic conditions. CONCLUSION: AMI and ischemia are associated with increased PAF levels in humans and pigs, which are further raised when fatal arrhythmia follows. The effects of PAF on the myocardium may be mediated by multiple ion channels.

[Clinical features and prognosis of 188 Chinese patients with apical hypertrophic cardiomyopathy].

OBJECTIVE: To analyze the clinical characteristics and prognosis of Chinese patients with apical hypertrophic cardiomyopathy (AHCM). METHODS: A total of 188 patients with AHCM diagnosed at Fuwai Hospital were included in this retrospective study. Clinical characteristics, mortality and cardiovascular morbidity were analyzed. A multiple logistic regression was performed to adjust for potential confounding factors. RESULTS: Males predominated with a number of 139 (73.9%) in this cohort. Patient's age ranged from 15 to 81 (51.9 ± 12.6) years. There were 120 patients (63.8%) with "pure" type and 68 patients (36.2%) with "mixed" type of AHCM, 171 patients were followed up for (5.0 ± 3.0) years, cardiovascular mortality was 1.2%, 28 patients (16.4%) experienced one or more cardiovascular events. CONCLUSION: The prevalence of AHCM is high in Chinese HCM patients, pure type AHCM is more common, and AHCM patients have a benign clinical course.

[Comparison of benazepril monotherapy to amlodipine plus benazepril in the treatment of patients with mild and moderate hypertension: a multicentre, randomized, double-blind, parallel-controlled study].

OBJECTIVE: To evaluate the efficacy and tolerability of the fixed combination of amlodipine 5 mg/benazepril 10 mg once-daily therapy, compared with benazepril, 10 mg, monotherapy in patients with mild and moderate hypertension, and to evaluate the 24 h antihypertensive efficacy and the duration of action by ambulatory blood pressure monitoring. METHODS: In a multicenter, randomized, double-blind, parallel controlled trial, 356 cases of hypertensive patients after 2 weeks wash-out, and then given 4 weeks of benazepril 10 mg monotherapy, 220 patients with mean seated diastolic blood pressure (SeDBP) remained ≥ 90 mm Hg (1 mm Hg = 0.133 kPa) were randomly divided into benazepril 10 mg/amlodipine 5 mg (BZ10/AML5) fixed-dose combination therapy group (once a day, n = 113), and benazepril monotherapy group (daily 20 mg, n = 107). In the two groups the patients with SeDBP ≥ 90 mm Hg were doubled the dosage of the initial regimen at the end of 4-week treatment for additional 4 weeks, and the patients with SeDBP < 90 mm Hg remained the initial regimen for additional 4 weeks. The primary endpoint was to evaluate the improvement of SeDBP at the end of 8-week treatment. There were 74 patients (the combination therapy group n = 38, monotherapy therapy group n = 36) completed the 24 h ambulatory blood pressure monitoring which was included in the final efficacy analysis. RESULTS: The randomized, double-blind treatment for 8 weeks, the mean value of SeDBP reduction, the reaching target blood pressure rate and total successful response rate to the treatment (a SeDBP < 90 mm Hg or a decrease of 10 mm Hg or more from baseline) were (11.7 ± 6.8) mm Hg, 65.7% and 88.5% in the combination therapy group, respectively, and were (7.7 ± 6.9) mm Hg, 35.5% and 65.5% in the monotherapy group, respectively. There were statistically significant difference between the combination therapy and the monotherapy groups in all the 3 indexs (P < 0.001). The fixed combination significantly reduced systolic blood pressure (SBP) and diastolic blood pressure (DBP) values throughout the 24 h. The trough to peak ratios of DBP/SBP in the fixed compound of benazepril/amlodipine (10 mg/5 mg) and benazepril (20 mg) alone were 83.1%/76.0% and 85.8%/79.5%, respectively. Adverse events rates were 16.8% in the combination therapy group and 35.5% in the monotherapy group (P < 0.001). CONCLUSIONS: The combination therapy with benazepril/amlodipine was superior to benazepril monotherapy and was well tolerated in patients with essential hypertension and allowing a satisfactory BP control for 24 hours.

Inhibitory Effects of Simvastatin on Oxidized Low-Density Lipoprotein-Induced Endoplasmic Reticulum Stress and Apoptosis in Vascular Endothelial Cells.

BACKGROUND: Oxidized low-density lipoprotein (ox-LDL)-induced oxidative stress and endothelial apoptosis are essential for atherosclerosis. Our previous study has shown that ox-LDL-induced apoptosis is mediated by the protein kinase RNA-like endoplasmic reticulum kinase (PERK)/eukaryotic translation initiation factor 2α-subunit (eIF2α)/CCAAT/enhancer-binding protein homologous protein (CHOP) endoplasmic reticulum (ER) stress pathway in endothelial cells. Statins are cholesterol-lowering drugs that exert pleiotropic effects including suppression of oxidative stress. This study aimed to explore the roles of simvastatin on ox-LDL-induced ER stress and apoptosis in endothelial cells. METHODS: Human umbilical vein endothelial cells (HUVECs) were treated with simvastatin (0.1, 0.5, or 2.5 µmol/L) or DEVD-CHO (selective inhibitor of caspase-3, 100 µmol/L) for 1 h before the addition of ox-LDL (100 µg/ml) and then incubated for 24 h, and untreated cells were used as a control group. Apoptosis, expression of PERK, phosphorylation of eIF2α, CHOP mRNA level, and caspase-3 activity were measured. Comparisons among multiple groups were performed with one-way analysis of variance (ANOVA) followed by post hoc pairwise comparisons using Tukey's tests. A value of P < 0.05 was considered statistically significant. RESULTS: Exposure of HUVECs to ox-LDL resulted in a significant increase in apoptosis (31.9% vs. 4.9%, P < 0.05). Simvastatin (0.1, 0.5, and 2.5 µmol/L) led to a suppression of ox-LDL-induced apoptosis (28.0%, 24.7%, and 13.8%, F = 15.039, all P < 0.05, compared with control group). Ox-LDL significantly increased the expression of PERK (499.5%, P < 0.05) and phosphorylation of eIF2α (451.6%, P < 0.05), if both of which in the control groups were considered as 100%. Simvastatin treatment (0.1, 0.5, and 2.5 µmol/L) blunted ox-LDL-induced expression of PERK (407.8%, 339.1%, and 187.5%, F = 10.121, all P < 0.05, compared with control group) and phosphorylation of eIF2α (407.8%, 339.1%, 187.5%, F = 11.430, all P < 0.05, compared with control group). In contrast, DEVD-CHO treatment had no significant effect on ox-LDL-induced expression of PERK (486.4%) and phosphorylation of eIF2α (418.8%). Exposure of HUVECs to ox-LDL also markedly induced caspase-3 activity together with increased CHOP mRNA level; these effects were inhibited by simvastatin treatment. CONCLUSIONS: This study suggested that simvastatin could inhibit ox-LDL-induced ER stress and apoptosis in vascular endothelial cells.

Diagnostic and predictive values of procalcitonin in bloodstream infections for nosocomial pneumonia.

PURPOSE: We evaluated the diagnostic accuracy of PCT to distinguish between gram-negative (GN) and gram-positive (GP) bloodstream infections nosocomial pneumonia (NP) patients and compared PCT levels with the pneumonia severity index (PSI) for predicting mortality. METHODS: Data were collected retrospectively for blood culture-positive NP patients between January 2014 and August 2016. PCT levels were compared between patients with GN versus GP infections. Outcome variables included 28- and 60-day mortality. RESULTS: PCT level was higher in GN infections than in GP infections. PCT could differentiate between GN and GP infections with an AUC value of 0.706. At a PCT cutoff of 5.4 ng/mL, the specificity for GN infections were 80.3%. The AUCs for 28- and 60-day mortality were 0.758 and 0.759 for PSI, and 0.620 and 0.634 for PCT. Serum PCT level was less predictive of mortality in GN NP patients compared with that for GP NP patients. There was a significantly positive correlation between PCT and PSI, and the correlation in GP NP patients was better than that in GN NP patients. CONCLUSIONS: PCT could differentiate between GN and GP bloodstream infections in patients with NP. However, PCT levels were less predictive of mortality compared with the PSI.

Notch3 deficiency impairs coronary microvascular maturation and reduces cardiac recovery after myocardial ischemia.

RATIONALE: Vascular maturation plays an important role in wound repair post-myocardial infarction (MI). The Notch3 is critical for pericyte recruitment and vascular maturation during embryonic development. OBJECTIVE: This study is to test whether Notch3 deficiency impairs vascular maturation and blunts cardiac functional recovery post-MI. APPROACH AND RESULTS: Wild type (WT) and Notch3 knockout (Notch3KO) mice were subjected to MI by the ligation of left anterior descending coronary artery (LAD). Cardiac function and coronary blood flow reserve (CFR) were measured by echocardiography. The expression of angiogenic growth factor, pericyte/capillary coverage and arteriolar formation were analyzed. Loss of Notch3 in mice resulted in a significant reduction of pericytes and small arterioles. Notch3 KO mice had impaired pericyte/capillary coverage and CFR compared to WT mice. Notch3 KO mice were more prone to ischemic injury with larger infarcted size and higher rates of mortality. The expression of CXCR-4 and VEGF/Ang-1 was significantly decreased in Notch3 KO mice. Notch3 KO mice also had few NG2+/Sca1+ and NG2+/c-kit+ progenitor cells in the ischemic area and exhibited worse cardiac function recovery at 2weeks after MI. These were accompanied by a significant reduction of pericyte/capillary coverage and arteriolar maturation. Furthermore, Notch3 KO mice subjected to MI had increased intracellular adhesion molecule-2 (ICAM-2) expression and CD11b+ macrophage infiltration into ischemic areas compared to that of WT mice. CONCLUSION: Notch3 mutation impairs recovery of cardiac function post-MI by the mechanisms involving the pre-existing coronary microvascular dysfunction conditions, and impairment of pericyte/progenitor cell recruitment and microvascular maturation.

Loss of prolyl hydroxylase domain protein 2 in vascular endothelium increases pericyte coverage and promotes pulmonary arterial remodeling.

Pulmonary arterial hypertension (PAH) is a leading cause of heart failure. Although pulmonary endothelial dysfunction plays a crucial role in the progression of the PAH, the underlying mechanisms are poorly understood. The HIF-α hydroxylase system is a key player in the regulation of vascular remodeling. Knockout of HIF-2α has been reported to cause pulmonary hypertension. The present study examined the role of endothelial cell specific prolyl hydroxylase-2 (PHD2) in the development of PAH and pulmonary vascular remodeling. The PHD2f/f mouse was crossbred with VE-Cadherin-Cre promoter mouse to generate an endothelial specific PHD2 knockout (Cdh5-Cre-PHD2ECKO) mouse. Pulmonary arterial pressure and the size of the right ventricle was significantly elevated in the PHD2ECKO mice relative to the PHD2f/f controls. Knockout of PHD2 in EC was associated with vascular remodeling, as evidenced by an increase in pulmonary arterial media to lumen ratio and number of muscularized arterioles. The pericyte coverage and vascular smooth muscle cells were also significantly increased in the PA. The increase in vascular pericytes was associated with elevated expression of fibroblast specific protein-1 (FSP-1). Moreover, perivascular interstitial fibrosis of pulmonary arteries was significantly increased in the PHD2ECKO mice. Mechanistically, knockout of PHD2 in EC increased the expression of Notch3 and transforming growth factor (TGF-ß) in the lung tissue. We conclude that the expression of PHD2 in endothelial cells plays a critical role in preventing pulmonary arterial remodeling in mice. Increased Notch3/TGF-ß signaling and excessive pericyte coverage may be contributing to the development of PAH following deletion of endothelial PHD2.

[A prospective study on recurrent falls and related factors in elderly from the urban communities in Beijing].

OBJECTIVE: To investigate the incidence and risk factors for recurrent falls in community-dwelling elderly in Beijing. METHODS: A cross-sectional study was conducted in 472 elderly in the Longtan community of Dongcheng district,Beijing in 2009. Data on recurrent falls within the past 12 months were collected through face-to-face interview, with both single factor analysis and logistic regression analysis used to explore the related factors on recurrent falls in the elderly. RESULTS: The incidence of recurrent falls among 472 older adults was 6.1% (29) within the past 12 months. Results from logistic regression analysis showed that factors as higher family monthly income(OR = 1.39, 95% CI:0.67-2.16), afraid of being fallen(OR = 2.23, 95% CI:1.47-3.85)and abnormal static balance(OR = 2.48, 95% CI:1.84-4.05)were risk factors, while bench height in the surrounding environment(OR = 0.49, 95% CI:0.21-1.12)and easiness of access to daily supplies (OR = 0.41, 95%CI:0.14-1.16)were protective factors for recurrent falls. CONCLUSION: The incidence of recurrent falls among the elderly from the communities in Beijing was high. Since falls could be caused by various factors, intervention should be targeting on risk factors in a multi-dimensional way.