Heel height affects lower extremity frontal plane joint moments during walking

Wearing high heels alters walking kinematics and kinetics and can create potentially adverse effects on the body. Our purpose was to determine how heel height affects frontal plane joint moments at the hip, knee, and ankle, with a specific focus on the knee moment due to its importance in joint loading and knee osteoarthritis. 15 women completed overground walking using three different heel heights (1, 5, and 9 cm) for fixed speed (1.3 ms(-1)) and preferred speed conditions while kinematic and force platform data were collected concurrently. For both fixed and preferred speeds, peak internal knee abduction moment increased systematically as heel height increased (fixed: 0.46, 0.48, 0.55 N m kg(-1); preferred: 0.47, 0.49, 0.53 N m kg(-1)). Heel height effects on net frontal plane moments of the hip and ankle were similar to those for the knee; peak joint moments increased as heel height increased. The higher peak internal knee abduction moment with increasing heel height suggests greater medial loading at the knee. Kinetic changes at the ankle with increasing heel height may also contribute to larger medial loads at the knee. Overall, wearing high heels, particularly those with higher heel heights, may put individuals at greater risk for joint degeneration and developing medial compartment knee osteoarthritis.     

History of deceased organ donation, transplantation, and organ procurement organizations

The historical development of deceased organ donation, transplantation, and organ procurement organizations is reviewed. The concept of transplantation, taking parts from one animal or person and putting them into another animal or person, is ancient. The development of organ transplantation brought on the need for a source of organs. Although many early kidney transplants used kidneys from living donors, these donors could not satisfy the ever-growing need for organs, and extrarenal organs were recovered only from deceased donors. This need for organs to satisfy the great demand led to specialized organizations to identify deceased donors, manage them until recovery occurred, and to notify transplant centers that organs were available for their patients. The functions of these organ procurement organizations expanded to include other required functions such as education, accounting, and compliance with state and federal requirements. Because of the shortage of organs relative to the demand, lack of a unified organ allocation system, the perception that organs are a national resource and should be governed by national regulations, and to improve results of organ procurement organizations and transplant centers, the federal government has regulated virtually all phases of organ procurement and transplantation.     

Hemodynamic monitoring in the critically ill: spanning the range of kidney function

Critically ill patients often have deranged hemodynamics. Physical examination, central venous pressure, and pulmonary artery occlusion pressure ("wedge") have been shown to be unreliable at assessing volume status, volume responsiveness, and adequacy of cardiac output in critically ill patients. Thus, invasive and noninvasive cardiac output monitoring is a core feature of evaluating and managing a hemodynamically unstable patient. In this review, we discuss the various techniques and options of cardiac output assessment available to clinicians for hemodynamic monitoring in the intensive care unit. Issues related to patients with kidney disease, such as timing and location of arterial and central venous catheters and the approach to hemodynamics in patients treated by long-term dialysis also are discussed.     

Bacterial RNA induces myocyte cellular dysfunction through the activation of PKR

Severe sepsis and the ensuing septic shock are serious life threatening conditions. These diseases are triggered by the host's over exuberant systemic response to the infecting pathogen. Several surveillance mechanisms have evolved to discriminate self from foreign RNA and accordingly trigger effective cellular responses to target the pathogenic threats. The RNA-dependent protein kinase (PKR) is a key component of the cytoplasmic RNA sensors involved in the recognition of viral double-stranded RNA (dsRNA). Here, we identify bacterial RNA as a distinct pathogenic pattern recognized by PKR. Our results indicate that natural RNA derived from bacteria directly binds to and activates PKR. We further show that bacterial RNA induces human cardiac myocyte apoptosis and identify the requirement for PKR in mediating this response. In addition to bacterial immunity, the results presented here may also have implications in cardiac pathophysiology.     

Effects of Continuous Flow Left Ventricular Assist Device Support on Microvascular Endothelial Function

The effects of continuous flow left ventricular assist device (CF-LVAD) support on microvascular endothelial function in New York Heart Association (NYHA) class IV heart failure (HF) patients are currently unknown. Microvascular endothelial function was assessed by beat-to-beat plethysmographic measurement of finger arterial pulse wave signal changes for 5 min following reactive hyperemia. A group of seven NYHA class IV HF patients was evaluated before CF-LVAD placement (HF), and a second group of six NYHA class IV HF patients was evaluated 1–4 months following CF-LVAD placement (CF-LVAD). Additionally, a third group of seven age-matched healthy subjects served as controls (control). There was no significant (P > 0.05) difference among the three groups in age, weight, or height. Systolic blood pressure (BP) was significantly higher in the control group (120 ± 2 mmHg) as compared to that in the HF (97 ± 8 mmHg, P = 0.005) and CF-LVAD (106 ± 4 mmHg, P = 0.003) groups. Diastolic BP was significantly lower in the HF group (57 ± 5 mmHg) as compared to that in the control (71 ± 2 mmHg, P = 0.012) and CF-LVAD (80 ± 7 mmHg, P = 0.008) groups. The reactive hyperemic index (RHI), a measure of endothelial function, was significantly higher in the control group (2.373 ± 0.274) than in both the HF (1.543 ± 0.173, P = 0.013) and CF-LVAD (1.355 ± 0.163, P = 0.004) groups; however, there was no significant (P = 0.223) difference in RHI between the HF and CF-LVAD groups. The results of the present study demonstrate that while 1–4 months of CF-LVAD support do not negatively affect microvascular endothelial function, 1–4 months of CF-LVAD support do not significantly improve vascular function in resistance vessels.