Sequential activation of alpha-actin genes during avian cardiogenesis: vascular smooth muscle alpha-actin gene transcripts mark the onset of cardiomyocyte differentiation.

The expression of cytoplasmic beta-actin and cardiac, skeletal, and smooth muscle alpha-actins during early avian cardiogenesis was analyzed by in situ hybridization with mRNA-specific single-stranded DNA probes. The cytoplasmic beta-actin gene was ubiquitously expressed in the early chicken embryo. In contrast, the alpha-actin genes were sequentially activated in avian cardiac tissue during the early stages of heart tube formation. The accumulation of large quantities of smooth muscle alpha-actin transcripts in epimyocardial cells preceded the expression of the sarcomeric alpha-actin genes. The accumulation of skeletal alpha-actin mRNAs in the developing heart lagged behind that of cardiac alpha-actin by several embryonic stages. At Hamburger-Hamilton stage 12, the smooth muscle alpha-actin gene was selectively down-regulated in the heart such that only the conus, which subsequently participates in the formation of the vascular trunks, continued to express this gene. This modulation in smooth muscle alpha-actin gene expression correlated with the beginning of coexpression of sarcomeric alpha-actin transcripts in the epimyocardium and the onset of circulation in the embryo. The specific expression of the vascular smooth muscle alpha-actin gene marks the onset of differentiation of cardiac cells and represents the first demonstration of coexpression of both smooth muscle and striated alpha-actin genes within myogenic cells.

Implementing a pain management service at an Army Medical Center.

In 1999, the Joint Commission for Accreditation of Healthcare Organizations published comprehensive pain management standards. Previous research has shown that pain control in people with cancer remains a significant problem in health care, even though cancer pain can be managed effectively in up to 90% of patients. In addition, postoperatively, many patients fail to have adequate pain control because of staff failures to routinely assess pain and pain relief. Many patients, if not questioned, silently tolerate unrelieved pain. National guidelines were published that address both acute and cancer pain in 1992 and 1994, respectively. In 1995, Tripler Army Medical Center dedicated $300,000 to create a 24-hour Pain Management Service to improve pain management. This article describes the structure of, educational programs offered by, and system changes implemented by the Pain Management Service.

Impact of patient-prosthesis mismatch on exercise capacity in patients after bioprosthetic aortic valve replacement.

OBJECTIVE: It is presumed that patient-prosthesis mismatch (PPM) influences morbidity and mortality after aortic valve replacement (AVR). The aim of our study was to determine the impact of PPM on physical capacity. METHODS: Six months after AVR with a bioprosthesis, stress echocardiography was performed on a bicycle ergometer in 312 patients. Depending on gender, age and weight, the target exercise level for every patient was determined by a reference table. Maximum achieved workload is given as percentage of the predicted exercise capacity (PPEC). PPM was defined as an effective orifice area index