Ascorbate deficiency is common among peritoneal dialysis (PD) patients and can be identified readily with serum ascorbate measurements, researchers in Australia report.

ERECTILE dysfuction (ED), defined as the inability to reach or maintain an erection sufficient for satisfactory sexual performance, is age-related and an extremely prevalent medical condition. It is esti-mated to affect more than half of all men over the age of 60, and in the United States alone, ED will develop in more than 600,000 men aged 40-69 annually.1

PERITONITIS IS a frequent complication of continuous ambulatory peritoneal dialysis (CAPD) and the most common cause of CAPD failure. About 60% of patients receiving CAPD will have at least one episode of peritonitis during the first year of this mode of dialysis, according to Ram Gokal, MD, Consultant Nephrologist and Honorary Lecturer at the University of Manchester in the United Kingdom. CAPD peritonitis is associated with catheter loss, adhesions, increased protein loss, return to hemodialysis, and considerable morbidity.

MOST PATIENTS who have high BP have primary or essential hypertension, the cause of which is as yet unknown. About 5%-10% of adults with hypertension have an identifiable or "secondary" cause of their elevated BP. Although relatively rare, the diagnosis of secondary hypertension is important because, depending on the source, it may be possible to cure the underlying condition or tailor therapy as a means to achieving optimal BP control.

THE ACTIVE forms of vitamin D—calcitriol, paricalcitol, and doxercalciferol—which also are known as vitamin D receptor activators (VDRAs), have been largely used in nephrology only as a treatment for secondary hyperparathyroidism, an elevation in parathyroid hormone (PTH) due to renal failure. Serum levels of calcitriol, the native form of active vitamin D, decline as renal function worsens, and calcitriol deficiency is almost universal among untreated patients on dialysis.

ACUTE KIDNEY injury (AKI) is a complex disorder for which there is no uniform definition. AKI has been reported in up to 7% of hospitalized patients, but epidemiologic studies are sparse and confounded by differences in case definitions and heterogeneity in patient populations.

NEPHROGENIC systemic fibrosis (NSF) is a new fibrotic skin disease entity that was first recognized in 1997 in 15 patients re-ceiving hemodialysis. Early reports noted that NSF closely resembled scleromyxedema, but had a number of differentiating features. The entity was initially termed nephrogenic fibrosing dermopathy, and a case definition was established based on its characteristic clinical and histopathologic features.

PHOSPHORUS plays an important role in human life. It is an essential building block of the human body as a component of the bony skeleton, adenosine triphosphate, nucleic acids, phospholipid membranes, and blood and urinary buffers. An intricate regulatory system assures the maintenance of normal phosphorus homeostasis under normal circumstances.

THE STANDARD goal of ultrafiltration (UF) is the achievement of "dry weight," defined as the lowest weight a patient can tolerate without intradialytic symptoms or hypotension. It is well accepted that while body weight varies with total body water (TBW), weight alone does not provide comprehensive in-formation about the relationships between intravascular, interstitial, and intracellular fluid (ICF).

THE PROLIFERATION of medications to aid in the suppression of viral replication for persons with HIV infection has expanded at a pace almost unparalleled in any other field of medicine. For subspecialists who assist in the care of persons with HIV but do not prescribe the medications themselves, this proliferation of medications can certainly present challenges to keeping their education current.