Nephrology Section

Wake Forest, NC, United States

Nephrology Section

Wake Forest, NC, United States
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Kolbach-Mandel A.M.,Medical College of Wisconsin | Mandel N.S.,Mandel International Stone and Molecular Analysis Center | Mandel N.S.,Medical College of Wisconsin | Hoffmann B.R.,Medical College of Wisconsin | And 3 more authors.
Urolithiasis | Year: 2017

Many urine proteins are found in calcium oxalate stones, yet decades of research have failed to define the role of urine proteins in stone formation. This urine proteomic study compares the relative amounts of abundant urine proteins between idiopathic calcium oxalate stone forming and non-stone forming (normal) cohorts to identify differences that might correlate with disease. Random mid-morning urine samples were collected following informed consent from 25 stone formers and 14 normal individuals. Proteins were isolated from urine using ultrafiltration. Urine proteomes for each sample were characterized using label-free spectral counting mass spectrometry, so that urine protein relative abundances could be compared between the two populations. A total of 407 unique proteins were identified with the 38 predominant proteins accounting for >82% of all sample spectral counts. The most highly abundant proteins were equivalent in stone formers and normals, though significant differences were observed in a few moderate abundance proteins (immunoglobulins, transferrin, and epidermal growth factor), accounting for 13 and 10% of the spectral counts, respectively. These proteins contributed to a cationic shift in protein distribution in stone formers compared to normals (22% vs. 18%, p = 0.04). Our data showing only small differences in moderate abundance proteins suggest that no single protein controls stone formation. Observed increases in immunoglobulins and transferrin suggest increased inflammatory activity in stone formers, but cannot distinguish cause from effect in stone formation. The observed cationic shift in protein distribution would diminish protein charge stabilization, which could lead to protein aggregation and increased risk for crystal aggregation. © 2017 Springer-Verlag Berlin Heidelberg (outside the USA)


Anand S.,Stanford University | Johansen K.L.,University of California at San Francisco | Grimes B.,University of California at San Francisco | Kaysen G.A.,Nephrology Section | And 4 more authors.
Hemodialysis International | Year: 2013

Symptoms of sleep and mood disturbances are common among patients on dialysis and are associated with significant decrements in survival and health-related quality of life. We used data from the Comprehensive Dialysis Study (CDS) to examine the association of self-reported physical activity with self-reported symptoms of insomnia, restless legs syndrome (RLS), and depression in patients new to dialysis. The CDS collected data on physical activity, functional status, and health-related quality of life from 1678 patients on either peritoneal (n=169) or hemodialysis (n=1509). The Human Activity Profile was used to measure self-reported physical activity. Symptoms were elicited in the following manner: insomnia using three questions designed to capture difficulty in initiating or maintaining sleep, RLS using three questions based on the National Institutes of Health workshop, and depression using the two-item Patient Health Questionnaire. We obtained data on symptoms of insomnia and depression for 1636, and on symptoms of RLS for 1622 (>98%) patients. Of these, 863 (53%) reported one of three insomnia symptoms as occurring at a persistent frequency. Symptoms of RLS and depression occurred in 477 (29%) and 451 (28%) of patients, respectively. The Adjusted Activity Score of the Human Activity Profile was inversely correlated with all three conditions in models adjusting for demographics, comorbid conditions, and laboratory variables. Sleep and mood disturbances were commonly reported in our large, diverse cohort of patients new to dialysis. Patients who reported lower levels of physical activity were more likely to report symptoms of insomnia, RLS, and depression. Hemodialysis International © 2012 International Society for Hemodialysis.


Florescu D.F.,Transplant Infectious Diseases Program | Florescu M.C.,Nephrology Section | Stevens B.,University of Nebraska Medical Center | Hill L.,Transplant Infectious Diseases Program | Kalil A.C.,Transplant Infectious Diseases Program
Scandinavian Journal of Infectious Diseases | Year: 2012

Background: Data are lacking on the risk factors and outcomes of Staphylococcus aureus infections in kidney transplant recipients. Methods: Kidney recipients with S. aureus infections (n = 20) were retrospectively identified and compared to age- and transplant-type-matched (1:2) non-S. aureus-infected controls (n = 40). Risk factors for S. aureus infections were identified by conditional logistic regression analysis. Results: Methicillin-resistant S. aureus (MRSA) was the cause of 32.1% of infections. Localizations of the infections were as follows: skin 42.9%, intra-abdominal 35.7%, blood stream 7.1%, and pulmonary 10.7%. The infections developed at a median time of 29 days (range 0358 days) after transplantation. By univariate analysis, variables significantly associated with infection were steroid administration 4 weeks prior to infection (odds ratio (OR) 4.2, 95% confidence interval (95% CI) 1.1-15.8; p = 0.03) and the presence of a central venous catheter 7 days prior to infection (OR 5.6, 95% CI 1.1-27.8; p = 0.03). By multivariate analysis, subjects with steroid treatment during the previous 4 weeks had a 6.13-times higher risk of developing S. aureus infection (95% CI 1.5-25.7; p = 0.01), and the risk of infection decreased by a factor of 0.65 for every 1-y increase in age (95% CI 0.44-0.97; p = 0.03); these results were adjusted for matched criteria. Post-infection outcomes (cases vs controls) included graft loss (10% vs 0%; p = 0.11) and 12-month mortality (0% vs 2.5%; p = 0.99). Conclusions: Younger age and steroid treatment were significant independent risk factors associated with S. aureus infections after kidney transplantation. Graft and patient survival were not affected, but the study was not powered for these outcomes. © 2012 Informa Healthcare.


Anand S.,Stanford University | Chertow G.M.,Stanford University | Johansen K.L.,Nephrology Section | Johansen K.L.,University of California at San Francisco | And 5 more authors.
Journal of Renal Nutrition | Year: 2013

Objective: Although several studies have shown poorer survival among individuals with 25-hydroxy (OH) vitamin D deficiency, data on patients receiving dialysis are limited. Using data from the Comprehensive Dialysis Study (CDS), we tested the hypothesis that patients new to dialysis with low serum concentrations of 25-OH vitamin D would experience higher mortality and hospitalizations. Design: The CDS is a prospective cohort study.We recruited participants from 56 dialysis units located throughout the United States. Subjects and Intervention: We obtained data on demographics, comorbidites, and laboratory values from the CDS Patient Questionnaire as well as the Medical Evidence Form (CMS form 2728). Participants provided baseline serum samples for 25-OH vitamin D measurements. Main Outcome Measure: We ascertained time to death and first hospitalization as well as number of first-year hospitalizations via the U.S. Renal Data System standard analysis files. We used Cox proportional hazards to determine the association between 25-OH vitamin D tertiles and survival and hospitalization. For number of hospitalizations in the first year, we used negative binomial regression. Results: The analytic cohort was composed of 256 patients with Patient Questionnaire data and 25-OH vitamin D concentrations. The mean age of participants was 62 (±14.0) years, and mean follow-up was 3.8 years. Patients with 25-OH vitamin D concentrations in the lowest tertile (<10.6 ng/mL) at the start of dialysis experienced higher mortality (adjusted hazard ratio 1.75, 95% confidence interval [CI] 1.03-2.97) as well as hospitalization (adjusted hazard ratio 1.76, 95% CI 1.24-2.49). Patients in the lower 2 tertiles (<15.5 ng/mL) experienced a higher rate of hospitalizations in the first year (incidence rate ratio 1.70 [95% CI 1.06-2.72] for middle tertile, 1.66 [95% CI 1.10-2.51] for lowest tertile). Conclusion: We found a sizeable increase in mortality and hospitalization for patients on dialysis with severe 25-OH vitamin D deficiency. © 2013 National Kidney Foundation, Inc.


Alkhunaizi A.M.,Nephrology Section | Al Jishi H.A.,Dhahran Health Center | Al Sadah Z.A.,Dhahran Health Center
Eastern Mediterranean Health Journal | Year: 2013

High salt intake has been associated with adverse side-effects such as hypertension and cardiovascular disease. The amount of salt intake among the population of Saudi Arabia is not known. The objective of this study was to estimate the salt intake among residents of the Eastern region of Saudi Arabia by measuring 24-hour urinary sodium excretion. Urine samples were collected from 130 individuals aged over 14 years for measurement of levels of sodium and other electrolytes. A total of 87 samples met the criteria for accuracy and were analysed. Total mean 24-hour sodium excretion for the group was 140 (SD 49) mEq [153 (SD 52) mEq for males and 118 (SD 37) mEq for females]. These values exceed the recommended daily intake of sodium and may contribute to the risk of developing hypertension and cardiovascular disease in Saudi Arabia.


Kramer H.,Loyola University | Kramer H.,Loyola Medical Center | Berns J.S.,University of Pennsylvania | Choi M.J.,Johns Hopkins University | And 2 more authors.
American Journal of Kidney Diseases | Year: 2014

The benefits of and thresholds for 25-hydroxyvitamin D administration in individuals with chronic kidney disease (CKD) remain uncertain. In this report, NKF-KDOQI (National Kidney Foundation-Kidney Disease Outcomes Quality Initiative) endeavors to provide health care providers with the latest information on a controversial area in the management of CKD, the role for nutritional vitamin D. Although knowledge of the biological mechanisms of vitamin D for bone maintenance in individuals with all stages of CKD has expanded, no consensus currently exists within the medical community regarding methods for 25-hydroxyvitamin D supplementation or optimal 25-hydroxyvitamin D levels in individuals with CKD. Within this report, existing CKD guidelines are summarized and scrutinized and ongoing clinical trials are cited as sources for future guidance on the optimal management of vitamin D in CKD. © 2014 American Diabetes Association and the National Kidney Foundation.


Alkhunaizi A.M.,Nephrology Section | ElTigani M.A.,General Internal Medicine Unit | Rabah R.S.,Saudi Aramco | Nasr S.H.,Mayo Medical School
Clinical Nephrology | Year: 2016

Renal dysfunction in cholestatic liver disease is multifactorial. Acute kidney injury may develop secondary to renal vasoconstriction in the setting of peripheral vasodilation and relative hypovolemia, tubular obstruction by bile casts, and direct tubular toxicity from bile. Anabolic steroids are frequently used by athletes to boost endurance and increase muscle mass. These agents are a recently recognized cause of hepatotoxicity and jaundice and may lead to acute kidney injury. To increase awareness about this growing problem and to characterize the pathology of acute kidney injury in this setting, we report on a young male who developed acute kidney injury in the setting of severe cholestatic jaundice related to ingestion of anabolic steroids used for bodybuilding. Kidney biopsy showed bile casts within distal tubular lumina, filamentous bile inclusions within tubular cells, and signs of acute tubular injury. This report supports the recently re-emerged concept of bile nephropathy/ cholemic nephrosis. © 2016 Dustri-Verlag Dr. K. Feistle.


Djousse L.,Harvard University | Djousse L.,Boston Veterans Affairs Healthcare System | Benkeser D.,University of Washington | Arnold A.,University of Washington | And 10 more authors.
Circulation: Heart Failure | Year: 2013

Background-Although plasma free fatty acid (FFA) concentrations have been associated with lipotoxicity, apoptosis, and risk of diabetes mellitus and coronary heart disease, it is unclear whether FFA levels are associated with heart failure (HF). Methods and Results-To test the hypothesis that plasma concentration of FFAs is positively associated with incident HF, we prospectively analyzed data on 4248 men and women free of HF at baseline and >65 years old from the Cardiovascular Health Study. FFA concentration was measured in duplicate by the Wako enzymatic method. Incident HF was validated by a centralized Events Committee. We used Cox proportional hazards to estimate the hazard ratio of HF per SD of FFAs. During a median follow-up of 10.5 years, a total of 1286 new cases of HF occurred. In a multivariable model adjusting for clinic site, comorbidity, demographic, anthropometric, and lifestyle factors, each SD (0.2 mEq/L) higher plasma FFA was associated with 12% (95% confidence interval, 6%-19%) higher risk of HF. Controlling for time-varying diabetes mellitus and coronary heart disease did not change the results (hazard ratio per SD, 1.16 [95% confidence interval, 1.09-1.23]). Conclusions-A single measure of plasma FFA obtained later in life is associated with a higher risk of HF in older adults. Additional studies are needed to explore biological mechanisms by which FFAs may influence the risk of HF and determine whether FFAs could serve as a novel pharmacological target for HF prevention. © 2013 American Heart Association, Inc.

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