A Facile Surface Modification Scheme for Medical-Grade Titanium and Polypropylene Using a Novel Mussel-Inspired Biomimetic Polymer with Cationic Quaternary Ammonium Functionalities for Antibacterial Application

Medical device-associated infection remains a critical problem in the healthcare setting. Different clinical- or device-related methods have been attempted to reduce the infection rate. Among these approaches, creating a surface with bactericidal cationic functionality has been proposed. To do so, a sophisticated multi-step chemical procedure would be needed. Instead, a simple immersion approach was utilized in this investigation to render the titanium and polypropylene surface with the quaternary ammonium functionality by using a mussel-inspired novel lab-synthesized biomimetic catechol-terminated polymer, PQA-C8. The chemical oxidants, CuSO4/H2O2, as well as dopamine, were added into the novel PQA-C8 polymer immersion solution for one-step surface modification. Additionally, a two-step immersion scheme, in which the polypropylene substrate was first immersed in the dopamine solution and then in the PQA-C8 solution, was also attempted. Surface analysis results indicated the surface characteristics of the modified substrates were affected by the immersion solution formulation as well as the procedure utilized. The antibacterial assay has shown the titanium substrates modified by the one-step dopamine + PQA-C8 mixtures with the oxidants added and the polypropylene modified by the two-step scheme exhibited bacterial reduction percentages greater than 90% against both Gram-positive S. aureus and Gram-negative E. coli and these antibacterial substrates were non-cytotoxic.

[Predictive value of N-terminal B-type natriuretic peptide on outcome of elderly hospitalized non-heart failure patients]

Objective: To investigate the predictive value of N-terminal type B natriuretic peptide（NT-proBNP) on the prognosis of elderly hospitalized patients without heart failure（non-heart failure). Method: Elderly patients aged 65 years or older, who were admitted to Beijing Hospital from September 2018 to February 2019, were enrolled in this study. Patients with clinical diagnosis of heart failure or left ventricular ejection fraction（LVEF)<50% were excluded. The patients were divided into 2 groups based on the serum NT-proBNP level: low NT-proBNP group （<125 ng/L) and high NT-proBNP group（≥125 ng/L). Patients were followed up at 3, 6, and 12 months after enrollment, and the major adverse events were recorded. The composite endpoint events included all-cause mortality, readmission or Emergency Department visits. Cardiovascular events include death, readmission or emergency room treatment due to cardiogenic shock, myocardial infarction, angina pectoris, arrhythmia, heart failure or stroke/transient ischemic attack. Results: A total of 600 elderly patients with non-heart failure were included in the analysis. The average age was （74.9±6.5) years, including 304（50.7%) males. The median follow-up time was 344（265, 359) days. One hundred and seventy-eight（29.7%) composite endpoint events were recorded during the follow-up, 19（3.2%) patients died, and 12（2.0%) patients were lost to follow-up. There were 286(47.7%) cases in low NT-proBNP group and 314 cases（52.3%) in high NT-proBNP group. Patients were older, prevalence of atrial fibrillation and myocardial infarction was higher; MMSE scores and ADL scores, albumin and creatinine clearance rate were lower in high NT-proBNP group than in low NT-proBNP group（all P<0.05). At 1-year follow-up, the incidence of composite endpoint events was significantly higher in high NT-proBNP group than in low NT-proBNP group（33.4%（105/314) vs. 24.8%（71/286), P = 0.02). Cardiovascular events were more common in high NT-proBNP group than in low NT-proBNP group（17.5%（55/314) vs. 8.4%（24/286), P = 0.001). Kaplan-Meier survival analysis showed both composite endpoint events（Log-rank P=0.016) and cardiovascular events（Log-rank P=0.001) were higher in high NT-proBNP group than in low NT-proBNP group. All-cause mortality was also significantly higher in highNT-proBNP group than in lowNT-proBNP group（4.8%（15/314) vs. 1.4%（4/286), P = 0.020), and Kaplan-Meier survival analysis demonstrated borderline statistical significance（Log-rank P = 0.052). Cox proportional hazard regression analysis showed that after adjusting for age, sex, creatinine clearance rate, myocardial infarction, and atrial fibrillation, NT-proBNP remained as an independent risk factor for composite endpoint events（HR=1.376，95%CI 1.049-1.806, P=0.021), and cardiovascular events（HR=1.777, 95%CI 1.185-2.664, P=0.005), but not for all-cause mortality（P=0.206). Conclusions: NT-proBNP level at admission has important predictive value on rehospitalization and cardiovascular events for hospitalized elderly non-heart failure patients. NT-proBNP examination is helpful for risk stratification in this patient cohort.

Role of the Wnt/β-catenin signaling pathway in inducing apoptosis and renal fibrosis in 5/6-nephrectomized rats

Renal fibrosis is the final common pathway of all progressive renal disease. Excessive and chronic activation of the Wnt/β-catenin signaling pathway results in chronic kidney disease (CKD) progression. To mimic CKD, the present study used 5/6-nephrectomized rats, and alterations in kidney histology, expression of β-catenin and renal cell apoptosis were assessed. In addition, mesangial cells were cultured in vitro and transfected with β-catenin siRNA to evaluate the effect of blocking Wnt/β-catenin signaling on cell apoptosis and the expression of markers of renal fibrosis. The results demonstrated that CKD rat kidney tissues exhibited moderate renal fibrosis and significantly increased expression levels of β-catenin and apoptosis associated proteins compared with sham-operated rats. In vitro, silencing of β-catenin by siRNA attenuated tumor necrosis factor-α-induced apoptosis and decreased mRNA expression levels of various markers of fibrosis, including fibronectin, transforming growth factor-β, and collagen I, III and IV. In conclusion, inhibition of Wnt/β-catenin signaling by β-catenin silencing attenuated apoptosis and expression of fibrosis-associated markers in renal cells. The present study suggested that the Wnt/β-catenin signaling pathway may serve as a potential treatment strategy for renal fibrotic disorders.

The Glomerular Filtration Rate (GFR) at Dialysis Initiation and Mortality in Chronic Kidney Disease (CKD) in East Asian Populations: A Meta-analysis

Objective The impact of dialysis initiation on survival is still somewhat controversial. Given that race or ethnicity has been observed to be a predictor of mortality and the rate of progression of chronic kidney disease, we conducted a meta-analysis to investigate the effect of early vs. late dialysis initiation on mortality in East Asian populations. Methods All eligible cohort studies of target were selected from the MEDLINE (PubMed), EMBASE, The Cochrane Library and the Clinical Trials Registry databases from inception to October 2014. The data were extracted with all-cause mortality rates as the primary outcome, and pooled adjusted hazard ratios (HRs) with 95% confidence intervals (CIs) were calculated. Results Ten studies examined the association between early vs. late dialysis initiation and mortality. Compared to late dialysis initiation, patients who received early dialysis initiation had a higher overall mortality risk (adjusted HR, 1.36; 95% CI, 1.0-1.85; p<0.05) in East Asian populations. In a subgroup analysis, baseline characteristic differences (adjusted HR, 2.0; 95%CI, 1.56-2.57; p<0.001), initial dialysis modalities (adjusted HR, 2.12; 95% CI, 1.72-2.62; p<0.001) and follow up duration (adjusted HR, 1.59; 95% CI, 1.19-2.12; p=0.002), demonstrated that the association between early dialysis initiation and mortality were significant. Conclusion A higher glomerular filtration rate (early) at the initiation of dialysis is associated with a higher all-cause mortality risk in East Asian populations.

Coexistence of superconductivity and antiferromagnetism in (Li0.8Fe0.2)OHFeSe

Iron selenide superconductors exhibit a number of unique characteristics that are helpful for understanding the mechanism of superconductivity in high-Tc iron-based superconductors more generally. However, in the case of AxFe2Se2 (A = K, Rb, Cs), the presence of an intergrown antiferromagnetic insulating phase makes the study of the underlying physics problematic. Moreover, FeSe-based systems intercalated with alkali metal ions, NH3 molecules or organic molecules are extremely sensitive to air, which prevents the further investigation of their physical properties. It is therefore desirable to find a stable and easily accessible FeSe-based superconductor to study its physical properties in detail. Here, we report the synthesis of an air-stable material, (Li0.8Fe0.2)OHFeSe, which remains superconducting at temperatures up to ~40 K, by means of a novel hydrothermal method. The crystal structure is unambiguously determined by a combination of X-ray and neutron powder diffraction and nuclear magnetic resonance. Moreover, antiferromagnetic order is shown to coexist with superconductivity. This synthetic route opens a path for exploring superconductivity in other related systems, and confirms the appeal of iron selenides as a platform for understanding superconductivity in iron pnictides more broadly.

Low-dose epidural dexmedetomidine improves thoracic epidural anaesthesia for nephrectomy

Thoracic epidural anaesthesia alone is an applied technique of anaesthesia for nephrectomy which has both advantages and limitations. Dexmedetomidine is a highly selective alpha2-adrenoreceptor agonist which has both central and peripheral analgesic properties. Forty patients undergoing nephrectomy were enrolled in this clinical trial and allocated randomly to two groups, a control group (C group) and a dexmedetomidine group (D group). The C group received epidural 0.75% levobupivacaine 12 ml with 1 ml of isotonic sodium chloride solution, while the D group received epidural 0.75% levobupivacaine 12 ml with 1 ml (0.5 µg/kg) of dexmedetomidine. Haemodynamic changes, onset time and duration of sensory and motor block, muscle relaxation score, verbal rating score for pain, sedation score and the total postoperative analgesic consumption were evaluated. Sensory blockade duration was longer in the D group than in the C group (P=0.01). The incidence of motor block and the muscle relaxation score were significantly higher in the D group compared with the C group (P=0.01). Compared with the C group, pain scores were significantly lower in the first four postoperative hours in the D group (two hours rest P=0.038; two hours activity P=0.009; four hours rest P=0.044; four hours activity P=0.003). The total amount of flurbiprofen analgesic was significantly lower in the D group compared with the C group (P=0.03). Epidural dexmedetomidine 0.5 µg/kg appears to intensify thoracic epidural anaesthesia with levobupivacaine.

[Experimental study on immunization of mice with nucleic acid vaccine Sj31BIN combining IL-12 against Schistosoma japonicum]

Based on the anti-fecundity effect of Schistosoma japonicum nucleic acid vaccine Sj31BIN, we combined Sj31BIN with IL-12 in vaccination of mice to explore the role of IL-12 as an adjuvant. The result showed that immunization of the mice with Sj31BIN + IL-12 led to a significant decrease in adult worm recovery, a liver egg count reduction of 59.74%, an intestine egg count reduction of 59.60% and a liver surface egg granuloma reduction of 71.3%. In addition, vaccination of the mice with IL-12 alone also led to some but not significant decrease in adult worm recovery and the egg counts. It is concluded that Sj31BIN plus IL-12 induces significant anti-fecundity immunity.

[Particle induced X-ray emission for trace element analysis of hairs from patients with cancer]

In this paper, trace element analysis of the hairs from the patients with nasopharyngeal carcinoma (NPC) and osteoma was made using particle induced X-ray emission (PIXE) technique in order to obtain some information on the correlation between trace element and these two tumors. The hair samples of 34 NPC patients were each collected before and three months after radiotherapy (60Co) (group 1). The hair specimens from 34 osteoma patients were collected preoperatively and postoperatively. For comparison, 65 hair samples were collected from 40 normal subjects (group 2) and 25 NPC patients, who had received radiotherapy (60Co) five years before without any recrudescence (group 3). The trace element analysis of all specimens was made by PIXE. The results show that there is a significant difference between groups 1 and 2 (P less than 0.01) but no difference is found between groups 2 and 3 for Mn, Cu, Zn, As etc. content in the hairs. Cu and Zn content in the hairs of the osteoma patients is much lower than that of the normal subjects (P less than 0.01) while for K, Ti and Mn content, the former is higher than the latter. The above experimental results are discussed in detail.