Different walls for rods and balls: the diversity of peptidoglycan

Peptidoglycan performs the essential role of resisting turgor in the cell walls of most bacteria. It determines cell shape, and its biosynthesis is the target for many important antibiotics. The fundamental chemical building blocks of peptidoglycan are conserved: repeating disaccharides cross-linked by peptides. However, these blocks come in many varieties and can be assembled in different ways. So beyond the fundamental similarity, prodigious chemical, organizational and architectural diversity is revealed. Here, we track the evolution of our current understanding of peptidoglycan and underpinning technical and methodological developments. The origin and function of chemical diversity is discussed with respect to some well-studied example species. We then explore how this chemistry is manifested in elegant and complex peptidoglycan organization and how this is interpreted in different and sometimes controversial architectural models. We contend that emerging technology brings about the possibility of achieving a complete understanding of peptidoglycan chemistry, through architecture, to the way in which diverse species and populations of cells meet the challenges of maintaining viability and growth within their environmental niches, by exploiting the bioengineering versatility of peptidoglycan

Association between angiographic culprit lesion and out-of-hospital cardiac arrest in ST-elevation myocardial infarction patients

BACKGROUND\nFactors related to the occurrence of out-of-hospital cardiac arrest (OHCA) in ST-elevation myocardial infarction (STEMI) are still poorly understood. The current study sought to compare STEMI patients presenting with and without OHCA to identify angiographic factors related to OHCA.\nMETHODS\nThis multicenter registry consisted of consecutive STEMI patients, including OHCA patients with return-of-spontaneous circulation. Patients were treated with primary percutaneous coronary intervention (PCI) and therapeutic hypothermia when indicated. Outcome consisted of in-hospital neurological recovery, scored using the Cerebral Performance Categories (CPC) scale, and 1-year survival. Logistic regression was used to identify factors associated with OHCA and survival was displayed with Kaplan-Meier curves and compared using log rank tests.\nRESULTS\nIn total, 224 patients presented with OHCA and 3259 without OHCA. Average age was 63.3 years and 75% of patients were male. OHCA occurred prior to ambulance arrival in 68% of patients and 48% required intubation. Culprit lesion was associated with OHCA: risk was highest for proximal left coronary lesions and lowest for right coronary lesions. Also, culprit lesion determined the risk of cardiogenic shock and sub-optimal reperfusion after PCI, which were strongly related to survival after OHCA. Neurological recovery was acceptable (CPC≤2) in 77.1% of OHCA patients and did not differ between culprit lesions.\nCONCLUSIONS\nIn the present STEMI population, coronary culprit lesion was associated with the occurrence of OHCA. Moreover, culprit lesion influenced the risk of cardiogenic shock and success of reperfusion, both of which were related to prognosis of OHCA patients.Perioperative Medicine: Efficacy, Safety and Outcom