Incidence of coronary-subclavian steal syndrome in patients undergoing noncardiac surgery

OBJECTIVE: To identify the incidence of coronary-subclavian steal syndrome in patients undergoing noncardiac surgery. DESIGN: Prospective. SETTING: Veterans Affairs Medical Center and university-affiliated medical center. PARTICIPANTS: Adult patients with prior coronary artery bypass graft surgery and documented use of an internal mammary artery. INTERVENTIONS: Bilateral simultaneous brachial blood pressures were determined noninvasively. The presumptive diagnosis of ipsilateral subclavian artery stenosis and coronary-subclavian steal syndrome was made if the systolic blood pressure differential was >20 mmHg. MEASUREMENTS AND MAIN RESULTS: The presumptive diagnosis of ipsilateral subclavian artery stenosis based on a blood pressure differential was made in 6 of 86 (5%) patients screened. The diagnosis of coronary-subclavian steal syndrome was confirmed at cardiac catheterization by observing retrograde internal mammary artery flow in 3 patients or lack of internal mammary artery flow in 1 patient (3.4%). All 4 patients with angiographic confirmation had either angina or silent ischemia. Three patients had successful carotid subclavian bypass, and 1 patient refused surgery. Two patients had no evidence of myocardial ischemia and underwent their planned procedure without incident. CONCLUSION: Coronary-subclavian steal syndrome occurs with relative frequency in noncardiac surgery patients with prior coronary artery bypass graft surgery using internal mammary artery conduits. Bilateral blood pressure measurements should be routinely performed during the preoperative evaluation. A pressure differential >20 mmHg should suggest the possibility of coronary-subclavian steal syndrome.     

Guideline for use of topical antimicrobial agents

This Guideline is based on published data available at the time of writing. The ideal means for comparing performance of various antimicrobial agents is through the conduct of carefully designed, large-scale clinical trials. Recommendations contained in this Guideline are subject to modification as additional data become available. It particularly should be noted that the implementation of universal precautions or body substance isolation has resulted in marked increase in the use of gloves for direct patient contact. Whether there is an additional cost-benefit rationale for handwashing with an antimicrobial agent remains to be studied.     

Phenotypic characterization of human colorectal cancer stem cells

Recent observations indicate that, in several types of human cancer, only a phenotypic subset of cancer cells within each tumor is capable of initiating tumor growth. This functional subset of cancer cells is operationally defined as the "cancer stem cell" (CSC) subset. Here we developed a CSC model for the study of human colorectal cancer (CRC). Solid CRC tissues, either primary tissues collected from surgical specimens or xenografts established in nonobese diabetic/severe combined immunodeficient (NOD/SCID) mice, were disaggregated into single-cell suspensions and analyzed by flow cytometry. Surface markers that displayed intratumor heterogeneous expression among epithelial cancer cells were selected for cell sorting and tumorigenicity experiments. Individual phenotypic cancer cell subsets were purified, and their tumor-initiating properties were investigated by injection in NOD/SCID mice. Our observations indicate that, in six of six human CRC tested, the ability to engraft in vivo in immunodeficient mice was restricted to a minority subpopulation of epithelial cell adhesion molecule (EpCAM)(high)/CD44+ epithelial cells. Tumors originated from EpCAM(high)/CD44+ cells maintained a differentiated phenotype and reproduced the full morphologic and phenotypic heterogeneity of their parental lesions. Analysis of the surface molecule repertoire of EpCAM(high)/CD44+ cells led to the identification of CD166 as an additional differentially expressed marker, useful for CSC isolation in three of three CRC tested. These results validate the stem cell working model in human CRC and provide a highly robust surface marker profile for CRC stem cell isolation.     

Controlled release of dexamethasone from PLGA microspheres embedded within polyacid-containing PVA hydrogels

The development of zero-order release systems capable of delivering drug(s) over extended periods of time is deemed necessary for a variety of biomedical applications. We hereby describe a simple, yet versatile, delivery platform based on physically cross-linked poly(vinyl alcohol) (PVA) microgels (cross-linked via repetitive freeze/thaw cycling) containing entrapped dexamethasone-loaded poly(lactic-co-glycolic acid) (PLGA) microspheres for controlled delivery over a 1-month period. The incorporation of polyacids, such as humic acids, Nafion, and poly(acrylic acid), was found to be crucial for attaining approximately zero-order release kinetics, releasing 60% to 75% of dexamethasone within 1 month. Microspheres alone entrapped in the PVA hydrogel resulted in negligible drug release during the 1-month period of investigation. On the basis of a comprehensive evaluation of the structure-property relationships of these hydrogel/microsphere composites, in conjunction with their in vitro release performance, it was concluded that these polyacids segregate on the PLGA microsphere surfaces and thereby result in localized acidity. These surface-associated polyacids appear to cause acid-assisted hydrolysis to occur from the surface inwards. Such systems show potential for a variety of localized controlled drug delivery applications such as coatings for implantable devices.     

Corporate Philanthropy Toward Community Health Improvement in Manufacturing Communities

Virtually all large employers engage in corporate philanthropy, but little is known about the extent to which it is directed toward improving community health. We conducted in-depth interviews with leaders of corporate philanthropy from 13 of the largest manufacturing companies in the US to understand how giving decisions were made, the extent to which funding was directed towards improving community health, and whether companies coordinate with local public health agencies. We found that corporate giving was sizable and directed towards communities in which the manufacturers have a large presence. Giving was aligned with the social determinants of health (i.e., aimed at improving economic stability, the neighborhood and physical environment, education, food security and nutrition, the community and social context, and the health care system). However, improving public health was not often cited as a goal of corporate giving, and coordination with public health agencies was limited. Our results suggest that there may be opportunities for public health agencies to help guide corporate philanthropy, particularly by sharing community-level data and offering their measurement and evaluation expertise.