A novel tissue culture model for evaluating the effect of aging on stem cell fate in adult microvascular networks

GeroScience - In vitro models of angiogenesis are valuable tools for understanding the underlying mechanisms of pathological conditions and for the preclinical evaluation of therapies. Our...     

The feasibility,acceptance, and key features of a prevention-focused oral health education program for HIV+ adults

Poor oral health is common in HIV+ adults. We explored the feasibility, acceptance, and key features of a prevention-focused oral health education program for HIV+ adults. This was a pilot substudy of a parent study in which all subjects (n = 112) received a baseline periodontal disease (PD) examination and provider-delivered oral health messages informed by the Information-Motivation-Behavioral Skills (IMB) Model. Forty-one parent study subjects were then eligible for the substudy; of these subjects, a volunteer sample was contacted and interviewed 3–6 months after the baseline visit. At the recall visit, subjects self-reported behavior changes that they had made since the baseline. PD was reassessed using standard clinical assessment guidelines, and results were shared with each subject. At recall, individualized, hands-on oral hygiene coaching was performed and patients provided feedback on this experience. Statistics included frequency distributions, means, and chi-square testing for bivariate analyses. Twenty-two HIV+ adults completed the study. At recall, subjects had modest, but nonsignificant (p > 0.05) clinician-observed improvement in PD. Each subject reported adopting, on average, 3.8 (± 1.5) specific oral health behavior changes at recall. By self-report, subjects attributed most behavior changes (95%) to baseline health messages. Behavior changes were self-reported for increased frequency of flossing (55%) and toothbrushing (50%), enhanced toothbrushing technique (50%), and improved eating habits (32%). As compared to smokers, nonsmokers reported being more optimistic about their oral health (p = 0.024) at recall and were more likely to have reported changing their oral health behaviors (p = 0.009). All subjects self-reported increased knowledge after receiving hands-on oral hygiene coaching performed at the recall visit. In HIV+ adults, IMB-informed oral health messages promoted self-reported behavior change, subjects preferred more interactive, hands-on coaching. We describe a holistic clinical behavior change approach that may provide a helpful framework when creating more rigorously designed IMB-informed studies on this topic.     

The Changing Face of Cardiac Surgery: Practice Patterns and Outcomes 2001-2010

Background

Advances in cardiac surgical care have allowed for successful surgery in high-risk elderly patients. Advances in percutaneous coronary intervention (PCI) techniques and expanded indications for PCI have resulted in a decrease in referrals for coronary artery bypass grafting (CABG). Our objective was to document changes in practice patterns and outcomes in a single tertiary cardiac surgery centre serving a large geographic area.

Methods

For all cardiac surgery cases performed from 2001-2010 we examined its use, patient clinical characteristics, and outcomes. Frailty was assessed using a measure we have previously demonstrated to be associated with adverse outcomes.

Results

During the study period, annual case volume decreased by 13%. The number of isolated CABG cases declined, and valve surgery and other complex procedures increased. The proportion of patients aged ≥ 80 years rose from 7%-12%, and the proportion of frail patients increased from 4%-10%. Although unadjusted in-hospital mortality remained relatively unchanged, intensive care unit (ICU) stays and prolonged institutional care increased. Older age and frailty were associated with mortality, prolonged ICU stays, prolonged institutional care, and a composite of mortality and major morbidities.

Conclusions

Our findings showed a decline in CABG, an increase in more complex operations, and an increase in prolonged ICU stays and prolonged institutional care. The proportion of frail and elderly patients increased over time and these patient groups were at higher risk of adverse postoperative outcomes. Particular attention is required in the decision for surgery and perioperative management of these patients.     

Synergistic effect between nisin and polymyxin B against pandrug-resistant and extensively drug-resistant Acinetobacter baumannii

Acinetobacter baumannii is an opportunistic pathogen predominantly associated with nosocomial infections. The World Health Organization's data on antibiotic-resistant ‘priority pathogens’ reports carbapenem-resistant A. baumannii as a pathogen which is in critical need of research and development of new antimicrobials. Emerging resistance against polymyxins, last-resort drugs for carbapenem-resistant A. baumannii, increases the need for new therapeutic approaches such as synergistic combinations. Nisin, an antibacterial peptide produced by the Gram-positive bacteria L. lactis, is a US Food and Drug Administration approved food preservative with bactericidal action predominantly against other Gram-positive bacteria. A 2008 study reported that topical nisin was effective against staphylococcal mastitis in humans. Additionally, nisin has shown activity against Gram-negative bacteria in combination with antimicrobials such as polymyxin B. A recent in vitro study reported that nisin and polymyxin B exhibited synergistic activity against one isolate each of A. baumannii, Acinetobacter lwoffii and Acinetobacter calcoaceticus using time-kill assay and checkerboard technique. We evaluated the synergistic potential of nisin and polymyxin B against 15 unique clinical A. baumannii isolates using time-kill assay. Three of eight (38%) extensively drug-resistant and six of seven (86%) pandrug-resistant A. baumannii isolates showed synergy with one or more combinations of nisin and polymyxin B. The synergy seen with the use of lower concentrations of polymyxin B may help in reducing the dose-dependent side effects. Additional studies involving pharmacokinetics and pharmacodynamics of nisin are required to explore clinical possibilities.