Development of soft tissue regenerative scaffold with antibacterial activity

With increasingly aging and sedentary populations, and with the rising incidence of diabetes and the associated diabetic ulcers, chronic wounds have been reported to be approaching pandemic proportions. Accumulation of wound bacteria forms a biofilm that can inhibit wound healing and the action of antibiotics. Conventional skin grafts can readily harbor bacterial and fungal cells while excluding penetration of larger immune cells and essential neo-vascularization. Soft tissue regenerative scaffolds with highly interconnected porosity have been developed for wound healing. In this research, scaffolds were fabricated with bioactive components to impart antibacterial activity. The interconnective porosity of the scaffold was preserved through using thermally forming composite scaffolds. Bioactive glass (45S5), bulk metallic glass (MgZnCa), and infused antibiotic (Cephazolin sodium) were utilised to form the composite antibiotic eluting scaffolds. A novel in vivo wound model was generated to simulate the wound environment. A confluent biofilm of Staphylococcus aureus was generated on polymer coupons using a bioreactor. The coupons were placed within nutrient agar dishes (simulating tissue) underneath scaffold specimens. Gravity fed perfusion flow was set up using a drip-set kit.The model successfully replicated the planktonic phase of the Staph. aureus life-cycle and infection of the scaffold from the wound model. Bioactive glass by itself did not contribute any detectable Staph.antibacterial activity whether on the scaffold or fused to a silicone substrate. However, when bioactive glass was present with MgZnCa and antibiotic, a mild synergistic improvement in antibacterial activity was observed. This strategy may facilitate soft tissue adhesion and further militate against bacterial infection. This study is the first report of an in-vitro wound model with an infusion method and planktonic bacteria phase, applied to assess antibacterial synthetic scaffold

The Kondo lattice model with correlated conduction electrons

We investigate a Kondo lattice model with correlated conduction electrons. Within dynamical mean-field theory the model maps onto an impurity model where the host has to be determined self-consistently. This impurity model can be derived from an Anderson-Hubbard model both by equating the low-energy excitations of the impurity and by a canonical transformation. On the level of dynamical mean-field theory this establishes the connection of the two lattice models. The impurity model is studied numerically by an extension of the non-crossing approximation to a two-orbital impurity. We find that with decreasing temperature the conduction electrons first form quasiparticles unaffected by the presence of the lattice of localized spins. Then, reducing the temperature further, the particle-hole symmetric model turns into an insulator. The quasiparticle peak in the one-particle spectral density splits and a gap opens. The size of the gap increases when the correlations of the conduction electrons become stronger. These findings are similar to the behavior of the Anderson-Hubbard model within dynamical mean-field theory and are obtained with much less numerical effort.Comment: 7 pages RevTeX with 3 ps figures, accepted by PR

Patient experiences of, and preferences for, surgical wound care education

The aim of this study was to describe patients' experiences of, and preferences for, surgical wound care discharge education and how these experiences predicted their ability to self-manage their surgical wounds. A telephone survey of 270 surgical patients was conducted across two hospitals two weeks after discharge. Patients preferred verbal (n = 255, 94.8%) and written surgical wound education (n = 178, 66.2%) from medical (n = 229, 85.4%) and nursing staff (n = 211, 78.7%) at discharge. The most frequent education content that patients received was information about follow-up appointments (n = 242, 89.6%) and who to contact in the community with wound care concerns (n = 233, 86.6%). Using logistic regression, patients who perceived that they participated in surgical wound care decisions were 6.5 times more likely to state that they were able to manage their wounds at home. Also, patients who agreed that medical and/or nursing staff discussed wound pain management were 3.1 times more likely to report being able to manage their surgical wounds at home. Only 40% (107/270) of patients actively participated in wound-related decision-making during discharge education. These results uncovered patient preferences, which could be used to optimise discharge education practices. Embedding patient participation into clinical workflows may enhance patients' self-management practices once home

Pre-operative and post-operative recommendations to surgical wound care interventions: a systematic meta-review of Cochrane reviews

Background: The increasing numbers of surgeries involving high risk, multi-morbid patients, coupled with inconsistencies in the practice of perioperative surgical wound care, increases patients’ risk of surgical site infection and other wound complications. Objectives: To synthesise and evaluate the recommendations for nursing practice and research from published systematic reviews in the Cochrane Library on nurse-led pre-operative prophylaxis and post-operative surgical wound care interventions used or initiated by nurses. Design: Meta-review, guided by the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Data sources: The Cochrane Library database. Review methods: All Cochrane Systematic Reviews were eligible. Two reviewers independently selected the reviews and extracted data. One reviewer appraised the methodological quality of the included reviews using A MeaSurement Tool to Assess Systematic Reviews 2 (AMSTAR 2) checklist. A second reviewer independently verified these appraisals. The review protocol was registered with the Prospective Register of Systematic Reviews. Results: Twenty-two Cochrane reviews met the inclusion criteria. Of these, 11 reviews focused on pre-operative interventions to prevent infection, while 12 focused on post-operative interventions (one review assessed both pre-and post-operative interventions). Across all reviews, 14 (63.6%) made at least one recommendation to undertake a specific practice, while two reviews (9.1%) made at least one specific recommendation not to undertake a practice. In relation to recommendations for further research, insufficient sample size was the most predominant methodological issue (12/22) identified across reviews. Conclusions: The limited number of recommendations for pre- and post-operative interventions reflects the paucity of high-quality evidence, suggesting a need for rigorous trials to address these evidence gaps in fundamentals of nursing care

Preoperative and postoperative recommendations to surgical wound care interventions: a systematic meta-review of Cochrane reviews

Background: The increasing numbers of surgeries involving high risk, multi-morbid patients, coupled with inconsistencies in the practice of perioperative surgical wound care, increases patients’ risk of surgical site infection and other wound complications. Objectives: To synthesise and evaluate the recommendations for nursing practice and research from published systematic reviews in the Cochrane Library on nurse-led preoperative prophylaxis and postoperative surgical wound care interventions used or initiated by nurses. Design: Meta-review, guided by the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. Data sources: The Cochrane Library database. Review methods: All Cochrane Systematic Reviews were eligible. Two reviewers independently selected the reviews and extracted data. One reviewer appraised the methodological quality of the included reviews using A MeaSurement Tool to Assess Systematic Reviews 2 checklist. A second reviewer independently verified these appraisals. The review protocol was registered with the Prospective Register of Systematic Reviews. Results: Twenty-two Cochrane reviews met the inclusion criteria. Of these, 11 reviews focused on preoperative interventions to prevent infection, while 12 focused on postoperative interventions (one review assessed both pre-postoperative interventions). Across all reviews, 14 (63.6%) made at least one recommendation to undertake a specific practice, while two reviews (9.1%) made at least one specific recommendation not to undertake a practice. In relation to recommendations for further research, insufficient sample size was the most predominant methodological issue (12/22) identified across reviews. Conclusions: The limited number of recommendations for pre-and-postoperative interventions reflects the paucity of high-quality evidence, suggesting a need for rigorous trials to address these evidence gaps in fundamentals of nursing care

Oral contraceptives and the absolute risk of venous thromboembolism in women with single or multiple thrombophilic defects - Results from a retrospective family cohort study

Background: The risk of venous thromboembolism (VTE) in women taking combined oral contraceptives (COCs) is attributed to changes in coagulation and fibrinolysis. Their impact may be greater in women with preexistent thrombophilic defects. Methods: We assessed the effects of COCs on absolute VTE risk in women with single or multiple thrombophilic defects in a retrospective family cohort study. Female relatives of probands with VTE and hereditary deficiencies of protein S, protein C, or antithrombin were tested for known thrombophilic defects, including the index deficiency. Absolute incidences of VTE were compared in deficient vs nondeficient women, in deficient and nondeficient women who ever or never used COCs, and in deficient and nondeficient women with 0, 1, or more than 1 other thrombophilic defect during exposure to COCs. Results: Of 222 women, 135(61%) ever used COCs. Overall, annual incidences of VTE were 1.64% and 0.18% in deficient and nondeficient women, respectively; the adjusted relative risk was 11.9 (95% confidence interval, 3.9-36.2). The risk was comparable in deficient ever and never users (1.73% vs 1.54%). Annual incidences during actual COC use were 4.62% in deficient women and 0.48% in nondeficient women; the relative risk was 9.7( 95% confidence interval, 3.0-42.4). The incidence increased by concomitant thrombophilic defects, from 3.49% to 12.00% in deficient women and from 0% to 3.13% in nondeficient women. Conclusions: Women with hereditary deficiencies of protein S, protein C, or antithrombin are at high risk of VTE during use of COCs, particularly when other thrombophilic defects are present. They have VTE at a younger age, but the overall risk is not increased by COCs