Micropattern width dependent sarcomere development in human ESC-derived cardiomyocytes.

In this study, human embryonic stem cell-derived cardiomyocytes were seeded onto controlled two-dimensional micropatterned features, and an improvement in sarcomere formation and cell alignment was observed in specific feature geometries. High-resolution photolithography techniques and microcontact printing were utilized to produce features of various rectangular geometries, with areas ranging from 2500 µm(2) to 160,000 µm(2). The microcontact printing method was used to pattern non-adherent poly(ethylene glycol) regions on gold coated glass slides. Matrigel and fibronectin extracellular matrix (ECM) proteins were layered onto the gold-coated glass slides, providing a controlled geometry for cell adhesion. We used small molecule-based differentiation and an antibiotic purification step to produce a pure population of immature cardiomyocytes from H9 human embryonic stem cells (hESCs). We then seeded this pure population of human cardiomyocytes onto the micropatterned features of various sizes and observed how the cardiomyocytes remodeled their myofilament structure in response to the feature geometries. Immunofluorescence was used to measure α-actinin expression, and phalloidin stains were used to detect actin presence in the patterned cells. Analysis of nuclear alignment was also used to determine how cell direction was influenced by the features. The seeded cells showed clear alignment with the features, dependent on the width rather than the overall aspect ratio of the features. It was determined that features with widths between 30 µm and 80 µm promoted highly aligned cardiomyocytes with a dramatic increase in sarcomere alignment relative to the long axis of the pattern. This creation of highly-aligned cell aggregates with robust sarcomere structures holds great potential in advancing cell-based pharmacological studies, and will help researchers to understand the means by which ECM geometries can affect myofilament structure and maturation in hESC-derived cardiomyocytes.

Acuity adaptable patient care unit system shortens length of stay and improves outcomes in adult cardiac surgery: University of Wisconsin experience.

OBJECTIVES: The Acuity Adaptable Patient Care (AAC) unit system allows all beds within a nursing unit to negate the need for transfer with changes in patient status. The unit is specialty specific to all levels of patient care. This system was implemented in March 2006 for cardiothoracic surgery at our institution. The purpose of this study was to evaluate the impact of the AAC system on the outcomes after adult cardiac surgery. METHODS: We retrospectively reviewed 2930 consecutive patients who underwent major adult cardiac procedures between January 2003 and December 2010. The cohorts were divided into the pre-AAC group (January 2003 to February 2006, n = 1029) and the AAC group (March 2006 to December 2010, n = 1901). Patient demographics and postoperative outcomes were assessed. RESULTS: The proportion of coronary artery bypass grafting was significantly lower (pre-AAC vs AAC: 43 vs 35%, P < 0.01), while those of aortic procedure (4 vs 11%, P < 0.01) and mechanical assist device insertion (3 vs 5%, P = 0.02) were higher in the AAC group. After the implementation of the AAC system, the incidence of all complications defined by the Society of Thoracic Surgeons (STS) database (49 vs 34%, P < 0.01), the median length of intensive care unit (ICU) stay (49 [interquartile range (IQR), 27-99] vs 26 [19-45] h, P < 0.01), that of hospital stay (6 [4-10] vs 5 [4-7] days, P < 0.01) and the readmission rate of ICU (5 vs 2% P < 0.01) were significantly decreased. Significant reductions in hospital mortality and the rate of hospital readmission <30 days were not observed. CONCLUSIONS: The implementation of the AAC system has improved the outcomes after major cardiac procedures. The incidence of postoperative complications and length of stay have all decreased significantly without increasing readmission rate. AAC creates a system of fluid care with specialty-trained nursing and other ancillary support that expedites discharge and improves overall patient outcomes.