Background: Atherosclerotic renal artery stenosis is increasingly common in an aging population. Therapeutic options include medical treatment only or revascularization procedures. Purpose:To compare the effects of medical treatment and revascularization on clinically important outcomes in adults with atherosclerotic renal artery stenosis. Data Sources:The MEDLINE database (inception to 6 September 2005) and selected reference lists were searched for English-language articles.

The heart and the kidneys share responsibility for maintaining hemodynamic stability and end-organ perfusion. Connections between these organs ensure that subtle physiologic changes in one system are tempered by compensation in the other through a variety of pathways and mediators. In the setting of underlying heart disease or chronic kidney disease, the capacity of each organ to respond to perturbation caused by the other may become compromised. This has recently led to the characterization of the cardiorenal syndrome (CRS). This review will primarily focus on CRS type 1 where acute decompensated heart failure (ADHF) results in activation of hemodynamic and neurohormonal factors leading to an acute drop in the glomerular filtration rate and the development of acute kidney injury. We will examine the scope and impact of this problem, the pathophysiology associated with this relationship, including underperfuson and venous congestion, diagnostic tools for earlier detection, and therapeutic interventions to prevent and treat this complication.

PrefaceWe are pleased to present the sixth edition of the Primer on Kidney Diseases. The Primer strives to remain a key resource for students, residents, fellows, and practitioners as they approach clinical challenges in nephrology, electrolyte and acid-base disorders, and hypertensive conditions. Although the text has been completely revised and updated to cover the quickly changing landscape of clinical nephrology, the accessibility and utility that define the Primer have been carefully preserved.This edition brings changes to the Primer. The Primer was first introduced in 1993, and developed through five editions by Arthur Greenberg and his editorial team of Alfred Cheung, Tom Coffman, Ron Falk, and Charles Jennette. With the sixth edition, the reins have been turned over to a new group, with Debbie Gipson, Mark Perazella, and Marcello Tonelli joining us in this exciting opportunity. Our new team brings a fresh perspective and a wealth of clinical experience to this effort. However, we continue the commitment of our predecessors to the careful selection of content and a diligent editorial process, stressing usability and clinical applicability.To maintain the Primer as a current review of clinical nephrology, we have included new sections that highlight recent advances in nephrology. Chapters on kidney development, assessment of kidney function, onconephrology, and transplant infectious disease have been added, and content on acute kidney injury, transplant medicine, and the kidney in the elderly has been expanded. Specific details on

Trichodysplasia spinulosa (TS) is a rare skin condition caused by trichodysplasia spinulosa-associated polyomavirus (TSPyV). It affects immunosuppressed patients, and <50 cases have been reported. The majority of these cases are seen in solid organ transplant recipients. TS often poses a diagnostic and therapeutic challenge because How to cite this article: Jose A, Dad T, Strand A, et al. Trichodysplasia spinulosa: Case reports and review of literature.

Purpose: To refine and evaluate methods for analysis of renal blood oxygenation level dependent (BOLD) MRI data. Materials and Methods:Color R2* maps and regions-ofinterest (ROIs) on the borderline between cortex and medulla were applied to renal BOLD MRI data of a group of 13 young female subjects. Results:The distribution of R2* within the kidneys was heterogeneous and the response of human kidneys to water diuresis was patchy. R2* values at the cortico-medullary border region have a smaller variation than in wider cortical or medullary regions and are sensitive to physiological changes produced by water diuresis. Conclusion:These methods provide improved visualization of the regional distribution of R2* and its variations and more precise quantification of the changes in renal R2* produced by water diuresis. BOLD MRI SIGNALS have previously been shown to correlate with oxygenation of hemoglobin in blood (1-4) and have been used to study renal tissue oxygenation during diuresis induced by water ingestion or by diuretics (5-8).The counter-current arrangement of capillary blood flow in the medulla of mammalian kidneys generates a gradient of oxygen tension between the renal cortex and the papillary tip that results in a state of relative hypoxia within the renal medulla, with important implications for renal physiology and disease (9 -11). The noninvasive technique of BOLD MRI can, in theory, permit the investigation of regional oxygenation of the kidney in normal human subjects and in disease states (5,13). It is therefore important to develop and refine techniques of obtaining and analyzing BOLD MRI images of the kidney that are precise and reproducible.The method of analyzing renal BOLD MRI data in previous studies has involved generating an R2* map in gray scale from a series of multi-TE gradient echo images. From these R2* maps a number of regions-ofinterests (ROIs) were selected at random in the medulla and cortex throughout the kidney. Mean R2* values and associated variances in the medulla and cortex were calculated in order to estimate changes in medullary or cortical oxygenation associated with diuresis (5,6). Owing to the complicated anatomy of the human kidney (Fig. 1a) and the random and arbitrary nature of ROI placement, a large variance of the averaged R2* values may obscure and limit the precise application of BOLD MRI to probe renal functions (12).Hypothesizing that visual assessment in conjunction with proper numerical sampling would improve our ability to extract information from renal BOLD MRI data, we have recently developed a color map scheme as a graphic alternative to access R2* changes within the kidney in conjunction with quantitative analysis of ROIs in borderline areas between the medulla and cortex (Fig. 1b). We have applied this method to BOLD MRI data of a group of normal subjects who underwent water diuresis. This paper communicates our results of utilizing the R2* color map and ROIs in borderline areas to assess the R2* changes produced in normal human kidneys by water diuresis.