[Investigation of risk factors of acute kidney injury after off-pump coronary artery bypass grafting and 3 years' follow-up]

OBJECTIVE

To investigate the incidence rate and risk factors of acute kidney injury (AKI) after off-pump coronary artery bypass grafting (CABG),and to compare the effects of AKI on complications after operation and major adverse cardiovascular and cerebrovascular events (MACCE) after 3 years' follow-up.

METHODS

In the study, 299 consecutive patients who underwent scheduled off-pump CABG from January 2010 to March 2012 were included. The patients were divided into AKI group with AKI and control group without AKI after operation. The data during perioperative stage were compared, and multivariable Logistic regression modeling was used to identify the risk factors of AKI. The complications were compared after surgery and the patients were followed up for 3 years to observe the difference of MACCE between the two groups.

RESULTS

AKI occurred in 37.1% patients (111/299). The elevated serum creatinine levels(Wald=9.276, P=0.002, 95%CI 1.006-1.028), chronic obstructive pulmonary disease(COPD) (Wald=3.469,P=0.063,95% CI 0.950-7.630), decreased left ventricular ejection fraction(LVEF)(Wald=4.414,P=0.036,95% CI 0.965-0.999),and implantation of intra-aortic balloon pump (IABP) before or after operation(Wald=6.745, P=0.009, 95% CI 1.336-7.925)were risk factors of AKI in multivariable logistic regression modeling. More complications occurred in AKI group, such as the duration of mechanic ventilation, the time of ICU and the length of stay post operation, reintubation, pulmonary infection, stroke, hemorrhage of digestive tract, the volume of blood transfusion (plasma and red blood cell) and renal replacement therapy(P <0.05). The difference of mortality rate had no statistical significance between the AKI group and the control group, but two patients died in the AKI group. The difference of MACCE between the two groups had no statistical significance after 3 years' follow-up either.

CONCLUSION

The incidence of AKI was high (37.1%) after off-pump CABG. The elevated serum creatinine levels, COPD, decreased LVEF,and implantation IABP before or after operation were independent risk factors of AKI in multivariable Logistic regression modeling. More complications occurred in AKI group during perioperative period, but the difference of MACCE between the two groups after 3 years' follow-up had no statistical significance.

Transluminal attenuation gradient and corrected models in coronary CT angiography for determining stenosis severity: a primary study using dual-source CT

AIM

To compare the incremental value of transluminal attenuation gradient (TAG), TAG with corrected contrast opacification (TAG-CCO), and TAG with exclusion of calcified coronary segments (TAG-ExC) in determining the stenosis severity of coronary arteries using coronary angiography (CAG) as the reference standard.

MATERIALS AND METHODS

One hundred and fifteen patients who underwent computed tomography coronary angiography (CTCA) and confirmed by coronary angiography (CAG) were included in the retrospective analysis. TAG, TAG-CCO, and TAG-ExC were calculated in 311 major epicardial coronary arteries. Changes in different TAG models were compared with corresponding stenosis severities ascertained by CAG. The diagnostic performances of TAG, TAG-CCO, TAG-ExC, and the TAG/CTCA, TAG-CCO/CTCA, and TAG-ExC/CTCA combinations over CTCA alone in evaluating stenosis severity were then analysed and compared. Furthermore, the incremental value of the TAG and the corrected models in the reclassification of CTCA-evaluated stenosis severity were calculated.

RESULTS

TAG, TAG-CCO, and TAG-ExC decreased gradually with increased stenosis severity (p<0.001 for all TAG models). TAG and TAG-ExC improved the diagnostic performance over CTCA in total vessel evaluation (c statistic= 0.926 versus 0.907, p=0.018; c statistic= 0.922 versus 0.907, p=0.030, respectively), but TAG-CCO did not. Meanwhile, adding TAG to CTCA enabled a significant reclassification in calcified vessels (n=95; net reclassification improvement = 0.143, p=0.038).

CONCLUSIONS

TAG and TAG-ExC improved the diagnostic performance of CTCA in all vessels. Adding TAG to CTCA significantly reclassified the calcified vessels. The additional value of TAG-CCO over CTCA alone in determining the stenosis severity is limited.

Chronic subdural hematoma management: clarifying the definitions of outcome measures to better understand treatment efficacy - a systematic review and meta-analysis

OBJECTIVE

A long history of inconsistencies in the definitions of the outcome measures for chronic subdural hematomas (CSDHs) has contributed to the controversy over the optimal surgical strategy for CSDH treatment. Clarifying these definitions, reassess the available data, and systematically review the prior literature may provide better insight into the differences in treatment efficacy for CSDH.

MATERIALS AND METHODS

The clinical course of CSDH was described with a series of strictly defined outcome measures. PubMed, Cochrane Library, and ScienceDirect databases were searched for comparative studies of two main surgical techniques for CSDH, including burr hole craniotomy (BHC) and twist drill craniotomy (TDC). Data were collected with uniform criteria and analyzed using a random-effects model to estimate the mortality, recurrence, operative failure, and cure rates of each treatment.

RESULTS

Twelve comparative studies that examined 2,027 CSDH patients were included. The analysis results indicated that TDC and BHC treatments were similar in the mortality rates (RR, 1.25; 95% CI, 0.83-1.87; I2 = 0%; p = 0.28) and the recurrence rates (RR, 1.29; 95% CI, 0.87-1.92; I2 = 13%; p = 0.21) for CSDH patients. However, TDC had a significantly higher operative failure rate compared with BHC (RR, 0.35; 95% CI, 0.15-0.83; I2 = 0%; p = 0.02), whereas patients treated by a TDC approach tended to achieve higher cure rates compared with BHC (RR, 0.92; 95% CI, 0.86-0.99; I2 = 55%; p = 0.02).

CONCLUSIONS

The clarification of the definitions related to CSDH outcome facilitates the interpretation of differences in treatment efficacy. The TDC approach manifested a significantly higher operative failure rate compared with the BHC approach; however, TDC showed a tendency in achieving a long-term neurologic cure.

[Expression of PAI-2 mRNA in peripheral blood leucocytes and regulation by sGC activator in pulmonary hypertension]

OBJECTIVE

To investigate the mRNA expression level of plasminogen activator inhibitor-2 (PAI-2) in peripheral blood leucocytes and regulation by soluble guanylate cyclase (sGC) activator in pulmonary hypertension.

METHODS

The human pulmonary arterial smooth muscle cells were treated with sGC activator Cinaciguat. The mRNA and protein expression levels of PAI-2 were detected with Real-time PCR and Western blot. The fresh blood samples of 8 patients with pulmonary arterial hypertension (PAH) (collected at the China-Japan Friendship Hospital from November 2014 to March 2015), 16 patients with chronic thromboembolic pulmonary hypertension (CTEPH) (collected at the China-Japan Friendship Hospital from November 2014 to March 2015), 24 age- and gender- matched healthy controls (collected at Beijing Hospital in March 2015) were treated with Cinaciguat for 8 hours. Then RNA of peripheral leukocytes was extracted and performed with reverse transcription and Real-time PCR to detect the mRNA level of PAI-2, which was compared between healthy controls and patients with pulmonary hypertension, before and after the treatment of Cinaciguat. At last, the correlation of PAI-2 mRNA level and the clinic severity of pulmonary hypertension were identified.

RESULTS

The mRNA and protein expression levels of PAI-2 were promoted by Cinaciguat in human pulmonary arterial smooth muscle cells. The baseline mRNA level of PAI-2 in peripheral leukocytes was significantly lower in PAH patients compared to the healthy controls (0.201±0.152, 0.660±0.440, P=0.021). There was no significant difference in the mRNA expression level of PAI-2 between the CTEPH patients and controls (0.428±0.364, 0.769±0.682, P=0.152). After Cinaciguat treatment, the mRNA expression levels of PAI-2 were up-regulated in PAH patients and CTEPH patients (1.352±1.127, 1.203±1.008), there was no significant difference in the mRNA expression level of PAI-2 among the PAH patients, CTEPH patients and controls (P=0.130, P=0.534). The baseline mRNA level of PAI-2 was negative correlated with echocardiography-estimated systolic pulmonary arterial pressure (sPAP) (r=-0.744, P=0.034).

CONCLUSIONS

The mRNA expression level of PAI-2 is significantly down-regulated in peripheral blood leucocytes and up-regulated by sGC activator in pulmonary hypertension. PAI-2 could be used as potential biomarker of pulmonary vascular remodeling in PAH.

An LES Turbulent Inflow Generator using A Recycling and Rescaling Method

The present paper describes a recycling and rescaling method for generating turbulent inflow conditions for Large Eddy Simulation. The method is first validated by simulating a turbulent boundary layer and a turbulent mixing layer. It is demonstrated that, with input specification of mean velocities and turbulence rms levels (normal stresses) only, it can produce realistic and self-consistent turbulence structures. Comparison of shear stress and integral length scale indicates the success of the method in generating turbulent 1-point and 2-point correlations not specified in the input data. With the turbulent inlet conditions generated by this method, the growth rate of the turbulent boundary/mixing layer is properly predicted. Furthermore, the method can be used for the more complex inlet boundary flow types commonly found in industrial applications, which is demonstrated by generating non-equilibrium turbulent inflow and spanwise inhomogeneous inflow. As a final illustration of the benefits brought by this approach, a droplet-laden mixing layer is simulated. The dispersion of droplets in the near-field immediately downstream of the splitter plate trailing edge where the turbulent mixing layer begins is accurately reproduced due to the realistic turbulent structures captured by the recycling/rescaling method.

[Association between OR2T3 gene and pulmonary arterial hypertension]

OBJECTIVE

To explore the pathogenic genes of pulmonary arterial hypertension (PAH) and validate the association between OR2T3 gene and PAH.

METHODS

Whole exome sequencing was performed in four patients and one healthy person as control in two pulmonary arterial hypertension pedigree; patient-specific variations were screened by bioinformatics methods and comparison between groups. To further analyze the association between these variations and PAH, Sanger sequencing was used to analyze the genotype of patient-specific variations of 30 patients with idiopathic PAH, 90 healthy people and 30 patients with chronic thromboembolic pulmonary hypertension.

RESULTS

The preliminary findings of whole exome sequencing were 57 variations may be associated with PAH; Among them, there were 6 AG heterozygotes due to OR2T3rs148748995 in the 30 idiopathic PAH patients, while no G allele carrier was found in other healthy people of two pulmonary arterial hypertension pedigree (AⅠ-1, AⅡ-3, BⅡ-1) and 90 normal control, and the difference was statistically significant (P<0.05). The variation also didn't exist in 30 chronic thromboembolic pulmonary hypertension patients.

CONCLUSION

OR2T3 gene may be the pathogenic gene of PAH and OR2T3rs148748995 could have a role in the development of PAH.

Muon-spin relaxation study of the double perovskite insulators Sr2 BOsO6 (B = Fe, Y, ln)

We present the results of zero-field muon-spin relaxation measurements made on the double perovskite insulators Sr2 BOsO6 (B = Fe,Y, In). Spontaneous muon-spin precession indicative of quasistatic long range magnetic ordering is observed in Sr2FeOsO6 within the AF1 antiferromagnetic phase for temperatures below [Formula: see text] K. Upon cooling below T2≈67 K the oscillations cease to be resolvable owing to the coexistence of the AF1 and AF2 phases, which leads to a broader range of internal magnetic fields. Using density functional calculations we identify a candidate muon stopping site within the unit cell, which dipole field simulations show to be consistent with the proposed magnetic structure. The possibility of incommensurate magnetic ordering is discussed for temperatures below TN = 53 K and 25 K for Sr2YOsO6 and Sr2InOsO6, respectively.

Humanized Mice as Preclinical Models in Transplantation

Animal models have been instrumental in our understanding of the mechanisms of rejection and the testing of novel treatment options in the context of transplantation. We have now entered an exciting era with research on humanized mice driving advances in translational studies and in our understanding of the function of human cells in response to pathogens and cancer as well as the recognition of human allogeneic tissues in vivo. In this chapter we provide a historical overview of humanized mouse models of transplantation to date, outlining the distinct strains and share our experiences in the study of human transplantation immunology.

Clinical Safety and Preliminary Efficacy of Plasmid pUDK-HGF Expressing Human Hepatocyte Growth Factor (HGF) in Patients with Critical Limb Ischemia

OBJECTIVE

Critical limb ischemia (CLI) is the most severe form of peripheral arterial disease and a major unmet public health care need. This phase I clinical study was performed to assess the safety and preliminary efficacy of naked plasmid DNA (pUDK-HGF) expressing human hepatocyte growth factor (HGF) in patients with critical limb ischemia (CLI).

DESIGN

Twenty-one patients with CLI were enrolled and randomly divided into four dose groups (4-16 mg) to receive local injection of pUDK-HGF into ischemic calf and/or thigh muscles twice on days 1 and 15. Safety, including adverse events and physiological parameters, and preliminary efficacy, including pain severity score (VAS), ulcer size, transcutaneous oxygen pressure (TcPO2), and ankle brachial index (ABI), were evaluated throughout a 3 month follow up period.

RESULTS

All doses of pUDK-HGF were well tolerated by the patients. None of the adverse effects was considered to be related to pUDK-HGF injection. Two significant clinical results were observed after pUDK-HGF administration. The mean VAS value of all patients decreased from 4.52 at baseline to 0.30 (p < .01), and pain had disappeared in 14 out of 17 evaluable patients by day 91. Two of four ulcers had completely healed, with the other two patients having more than 25% ulcer size reduction in the long axis diameter. Of five patients with gangrene, one gangrenous wound had healed completely and two patients showed marked size reduction by day 91. The mean hemodynamic parameters (ABI, TcPO2) were also improved.

CONCLUSION

Intramuscular injection of pUDK-HGF is safe, and may provide symptomatic relief for CLI patients. A larger, randomized, double blinded phase II trial will provide more information on safety and efficacy.

Association between loop diuretic use and fracture risk

SUMMARY

Loop diuretic use has been shown to be associated with an increased fracture risk, but the findings have been inconsistent. The present meta-analysis suggests that loop diuretics show a significant positive association with the overall risk of total fractures and, specifically, hip fractures.

INTRODUCTION

Despite being widely used, there is limited, prospective randomized trial evidence regarding the skeletal effects of loop diuretics. Previous observational studies have reported conflicting findings regarding the association between loop diuretic use and the risk of fractures.

METHODS

This meta-analysis of observational studies assessed the association between loop diuretic use and the risk of fractures. The PubMed, EMBASE, and OVID databases were searched for prospective cohort and case-control studies. Relative risks (RR) with 95% confidence intervals (CI) were derived using random-effects models throughout the analysis.

RESULTS

Thirteen studies (4 cohort studies and 9 case-control studies) were included, involving 842,644 participants and 108,247 fracture cases. Compared with non-users, people who had taken loop diuretics had an approximately 15% higher risk of total fractures (95% CI, 1.04-1.26; p<0.01), with high heterogeneity between studies (I2=80.5%; p<0.01). The RR was 1.14 (95% CI, 1.08-1.19) for hip fractures and 0.99 (95% CI, 0.93-1.05) for lower arm or wrist fractures. The RR was 1.05 (95% CI, 1.00-1.11) in prospective cohort studies and 1.22 (95% CI, 1.00-1.44) in case-control studies. There was no evidence of publication bias.

CONCLUSION

The results suggest that loop diuretics show a significant positive association with the overall risk of total fractures and hip fractures.

Removal of emerging contaminants by pre-mixed PACl and carbonaceous materials

In this study, pre-mixed poly aluminum chloride (PACl) and super powdered activated carbon (SPAC)/carbon nanotubes (CNT) were employed for the removal of emerging contaminants (ECs) from various water sources.

Correction: Removal of emerging contaminants by pre-mixed PACl and carbonaceous materials

Correction for ‘Removal of emerging contaminants by pre-mixed PACl and carbonaceous materials’ by W. Jiang et al., RSC Adv., 2015, 5, 35461–35468.

MicroRNA-885-3p inhibits the growth of HT-29 colon cancer cell xenografts by disrupting angiogenesis via targeting BMPR1A and blocking BMP/Smad/Id1 signaling

The previous studies in this lab discovered that microRNA-885-3p (miR-885-3p) was regulated by a sulfated polysaccharide that bound to bone morphogenetic protein receptor, type IA (BMPR1A) to inhibit angiogenesis. However, its specific role and its mechanism of action in tumor cells have not been elucidated. We show that miR-885-3p markedly suppresses angiogenesis in vitro and in vivo. MiR-885-3p inhibits Smad1/5/8 phosphorylation and downregulates DNA-binding protein inhibitor ID-1 (Id1), a proangiogenic factor, by targeting BMPR1A, leading to impaired angiogenesis. Overexpression or silencing of BMPR1A affects angiogenesis in a Smad/Id1-dependent manner. We further show that miR-885-3p impairs the growth of HT-29 colon cancer cell xenografts in nude mice by suppressing angiogenesis through disruption of BMPR1A and Smad/Id1 signaling. These results support a novel role for miR-885-3p in tumor angiogenesis by targeting BMPR1A, which regulates a proangiogenic factor, and provide new evidence that targeting miRNAs might be an effective therapeutic strategy for improving colon cancer treatment.

Slc26a3 deficiency is associated with loss of colonic HCO3 (-) secretion, absence of a firm mucus layer and barrier impairment in mice

AIM

Downregulated in adenoma (DRA, Slc26a3) is a member of the solute carrier family 26 (SLC26), family of anion transporters, which is mutated in familial chloride-losing diarrhoea (CLD). Besides Cl(-) -rich diarrhoea, CLD patients also have a higher-than-average incidence of intestinal inflammation. In a search for potential explanations for this clinical finding, we investigated colonic electrolyte transport, the mucus layer and susceptibility against dextran sodium sulphate (DSS)-induced colitis in Slc26a3(-/-) mice.

METHODS

HCO3 (-) secretory (JHCO3 (-) ) and fluid absorptive rates were measured by single-pass perfusion in vivo and in isolated mid-distal colonic mucosa in Ussing chambers in vitro. Colonocyte intracellular pH (pHi ) was assessed fluorometrically, the mucus layer by immunohistochemistry and colitis susceptibility by the addition of DSS to the drinking water.

RESULTS

HCO3 (-) secretory (JHCO3- ) and fluid absorptive rates were strongly reduced in Slc26a3(-/-) mice compared to wild-type (WT) littermates. Despite an increase in sodium/hydrogen exchanger 3 (NHE3) mRNA and protein expression, and intact acid-activation of NHE3, the high colonocyte pH in Slc26a3(-/-) mice prevented Na(+) /H(+) exchange-mediated fluid absorption in vivo. Mucin 2 (MUC2) immunohistochemistry revealed the absence of a firm mucus layer, implying that alkaline secretion and/or an absorptive flux may be necessary for optimal mucus gel formation. Slc26a3(-/-) mice were highly susceptible to DSS damage.

CONCLUSIONS

Deletion of DRA results in severely reduced colonic HCO3 (-) secretory rate, a loss of colonic fluid absorption, a lack of a firmly adherent mucus layer and a severely reduced colonic mucosal resistance to DSS damage. These data provide potential pathophysiological explanations for the increased susceptibility of CLD patients to intestinal inflammation.

A yellow-emitting phosphor of Mn(2+)-doped Na2CaP2O7

A yellow-emitting Na2CaP2O7:Mn(2+)phosphors have been synthesized by solid state reaction. The crystal structure, photoluminescence properties as well as concentration quenching mechanism have been investigated. The (4)T1-(6)A1 emission of Mn(2+)in Na2CaP2O7 phosphor ranges from 500 to 650 nm and exhibits a red shift while increasing the Mn(2+)concentration. The crystal field strength is calculated based on the combination of excitation spectrum and Tanabe-Sugano diagram. The chromaticity coordinates of Na2CaP2O7:Eu(2+), Mn(2+)phosphors were discussed in order to develop the potential application in white light-emitting diodes (LEDs).

Investigation of the shape change of bio-flocs and its influence on mass transport using particle image velocimetry

In this laboratory study, an advanced flow visualization technique - particle image velocimetry (PIV) - was employed to investigate the change of shape of activated sludge flocs in water and its influence on the material transport characteristics of the flocs. The continuous shape change of the bio-flocs that occurred within a very short period of time could be captured by the PIV system. The results demonstrate that the fluid turbulence caused the shift of parts of a floc from one side to the other in less than 200 ms. During the continuous shape change, the liquid within the floc was forced out of the floc, which was then refilled with the liquid from the surrounding flow. For the bio-flocs saturated with a tracer dye, it was shown that the dye could be released from the flocs at a faster rate when the flocs were swayed around in water. The experimental results indicate that frequent shape change of bio-flocs facilitates the exchange of fluid and materials between the floc interior and the surrounding water. This mass transfer mechanism can be more important than molecular diffusion and internal permeation to the function and behavior of particle aggregates, including bio-flocs, in natural waters and treatment systems.

Effect of penehyclidine hydrochloride on β-arrestin-1 expression in lipopolysaccharide-induced human pulmonary microvascular endothelial cells

β-arrestins are expressed proteins that were first described, and are well-known, as negative regulators of G protein-coupled receptor signaling. Penehyclidine hydrochloride (PHC) is a new anti-cholinergic drug that can inhibit biomembrane lipid peroxidation, and decrease cytokines and oxyradicals. However, to date, no reports on the effects of PHC on β-arrestin-1 in cells have been published. The aim of this study was to investigate the effect of PHC on β-arrestin-1 expression in lipopolysaccharide (LPS)-induced human pulmonary microvascular endothelial cells (HPMEC). Cultured HPMEC were pretreated with PHC, followed by LPS treatment. Muscarinic receptor mRNAs were assayed by real-time quantitative PCR. Cell viability was assayed by the methyl thiazolyl tetrazolium (MTT) conversion test. The dose and time effects of PHC on β-arrestin-1 expression in LPS-induced HPMEC were determined by Western blot analysis. Cell malondialdehyde (MDA) level and superoxide dismutase (SOD) activity were measured. It was found that the M3 receptor was the one most highly expressed, and was activated 5 min after LPS challenge. Furthermore, 2 μg/mL PHC significantly upregulated expression of β-arrestin-1 within 10 to 15 min. Compared with the control group, MDA levels in cells were remarkably increased and SOD activities were significantly decreased in LPS pretreated cells, while PHC markedly decreased MDA levels and increased SOD activities. We conclude that PHC attenuated ROS injury by upregulating β-arrestin-1 expression, thereby implicating a mechanism by which PHC may exert its protective effects against LPS-induced pulmonary microvascular endothelial cell injury.