Cryo-EM of CcsBA reveals the basis for cytochrome c biogenesis and heme transport.

Although the individual structures and respiratory functions of cytochromes are well studied, the structural basis for their assembly, including transport of heme for attachment, are unknown. We describe cryo-electron microscopy (cryo-EM) structures of CcsBA, a bifunctional heme transporter and cytochrome c (cyt c) synthase. Models built from the cryo-EM densities show that CcsBA is trapped with heme in two conformations, herein termed the closed and open states.

In vitro reconstitution reveals major differences between human and bacterial cytochrome c synthases.

Cytochromes c are ubiquitous heme proteins in mitochondria and bacteria, all possessing a CXXCH (CysXxxXxxCysHis) motif with covalently attached heme. We describe the first in vitro reconstitution of cytochrome c biogenesis using purified mitochondrial (HCCS) and bacterial (CcsBA) cytochrome c synthases. We employ apocytochrome c and peptide analogs containing CXXCH as substrates, examining recognition determinants, thioether attachment, and subsequent release and folding of cytochrome c.

Partnering to Promote Evidence-Based Practice in a Community Hospital: Implications for Nursing Professional Development Specialists.

Nursing professional development specialists working in community hospitals face significant barriers to evidence-based practice that academic medical centers do not. This article describes 7 years of a multifaceted, service academic partnership in a large, urban, community hospital. The partnership has strengthened the nursing professional development role in promoting evidence-based practice across the scope of practice and serves as a model for others.

Biomechanical comparison of median sternotomy closures.

Background: Poor healing of median sternotomy can significantly increase morbidity, mortality, and hospital costs. Effective union requires reliable sternal fixation. Although wire has proven the most reliable and widely used sternotomy closure material, no experimental studies have compared a large variety of wiring techniques in a human model.

Biomechanical porcine model of median sternotomy closure.

Background: Healing complications following median sternotomy commonly include instability, nonunion, and infection. They are associated with a high mortality rate if mediastinitis supervenes. Closure complications are best avoided by improving stability at the union, but there has thus far been no widespread agreement among surgeons about relative superiority among the available closure techniques.