Enzyme immobilisation in permselective microcapsules

The objective of this investigation was to study the permselective behaviour of calcium alginate membranes, including the modifying effects of silica additives, which were subsequently used as microcapsule shells. Diffusion experiments and HPLC were carried out to ascertain the size-exclusion property of the membranes for a mixed molecular-weight dextran solution. Hollow microcapsules containing the enzyme dextranase were prepared using double concentric nozzles and the encapsulation performance was evaluated based on an analysis of the enzyme reactivity and stability. To improve mass transport within the microcapsules, magnetic nanoparticles were introduced into the liquid core and agitated using an alternating external magnetic field. The modified membranes exhibited better size-exclusion behaviour than the unmodified membranes. The magnetic nanoparticles slightly improved mass transport inside the microcapsule. The encapsulated enzyme yielded nearly 80% of the free enzyme activity and retained about 80% of the initial catalytic activity even after being used for eight reaction cycles.     

Liver transplantation and atrial fibrillation: A meta-analysis

AIM To assess prevalence of pre-existing atrial fibrillation(AF) and/or incidence of AF following liver transplantation, and the trends of patient's outcomes overtime; to evaluate impact of pre-existing AF and post-operative AF on patient outcomes following liver transplantation. METHODS A literature search was conducted utilizing MEDLINE, EMBASE and Cochrane Database from inception throughMarch 2018. We included studies that reported:(1) prevalence of pre-existing AF or incidence of AF following liver transplantation; or(2) outcomes of liver transplant recipients with AF. Effect estimates from the individual study were extracted and combined utilizing randomeffect, generic inverse variance method of DerSimonian and Laird. The protocol for this meta-analysis is registered with PROSPERO(International Prospective Register of Systematic Reviews, No. CRD42018093644). RESULTS Twelve observational studies with a total of 38586 liver transplant patients were enrolled. Overall, the pooled estimated prevalence of pre-existing AF in patients undergoing liver transplantation was 5.4%(95%CI: 4.9%-5.9%) and pooled estimated incidence of AF following liver transplantation was 8.5%(95%CI: 5.2%-13.6%). Meta-regression analyses were performed and showed no significant correlations between year of study and either prevalence of pre-existing AF(P = 0.08) or post-operative AF after liver transplantation(P = 0.54). The pooled OR of mortality among liver transplant recipients with pre-existing AF was 2.34(2 studies; 95%CI: 1.10-5.00). In addition, pre-existing AF is associated with postoperative cardiovascular complications among liver transplant recipients(3 studies; OR: 5.15, 95%CI: 2.67-9.92, I2 = 64%). With limited studies, two studies suggested significant association between new-onset AF and poor clinical outcomes including mortality, cerebrovascular events, post-transplant acute kidney injury, and increased risk of graft failure among liver transplant recipients(P 0.05).CONCLUSION The overall estimated prevalence of pre-existing AF and incidence of AF following liver transplantation are 5.4% and 8.5%, respectively. Incidence of AF following liver transplant does not seem to decrease overtime. Preexisting AF and new-onset AF are potentially associated with poor clinical outcomes post liver transplantation.     

Erectile dysfunction and atrial fibrillation: A systematic review and meta‐analysis

Objective

To investigate the pooled incidence or the prevalence of erectile dysfunction, and to assess the risk of erectile dysfunction in patients with atrial fibrillation.

Methods

A systematic review was carried out in the MEDLINE, EMBASE and Cochrane databases from inception through January 2018 to identify: (i) studies that reported the incidence and/or prevalence of erectile dysfunction in atrial fibrillation patients; or (ii) studies that assessed the association between atrial fibrillation and erectile dysfunction. Pooled odds ratios and 95% confidence intervals were calculated using a random effects model.

Results

Five observational studies (27 841 patients) were enrolled. The pooled estimated prevalence of erectile dysfunction in atrial fibrillation patients was 57% (95% confidence interval 50–64, I² = 0). A study showed an incidence of newly diagnosed erectile dysfunction in atrial fibrillation patients of 0.96% during the mean follow‐up duration of 4.67 ± 3.20 years. There was a significant association of atrial fibrillation with an increased risk of erectile dysfunction, with a pooled odds ratio of 1.79 (95% confidence interval 1.44–2.23, I² = 0%). The data on the risk of atrial fibrillation development in patients with erectile dysfunction were limited. A study showed the comparable risk of atrial fibrillation in patients with erectile dysfunction (odds ratio 1.03, 95% confidence interval 0.67–1.5), when compared with those without erectile dysfunction.

Conclusions

The present study suggests a significant association between erectile dysfunction and atrial fibrillation. The overall estimated prevalence of erectile dysfunction among atrial fibrillation patients is 57%. However, despite limited data, the current evidence suggests a low incidence of new erectile dysfunction in atrial fibrillation patients.