Estimation of nephron number in living humans by combining unenhanced computed tomography with biopsy-based stereology.

Methods for estimating nephron number in a clinical setting may be useful for predicting renal outcomes. This study aimed to establish such a method using unenhanced computed tomography (CT) and biopsy-based stereology. Patients or living kidney donors simultaneously subjected to enhanced and unenhanced CT examinations were randomly assigned to development and validation groups.

CKD: A Call for an Age-Adapted Definition.

Current criteria for the diagnosis of CKD in adults include persistent signs of kidney damage, such as increased urine albumin-to-creatinine ratio or a GFR below the threshold of 60 ml/min per 1.73 m This threshold has important caveats because it does not separate kidney disease from kidney aging, and therefore does not hold for all ages. In an extensive review of the literature, we found that GFR declines with healthy aging without any overt signs of compensation (such as elevated single-nephron GFR) or kidney damage.

In-vivo techniques for determining nephron number.

Purpose Of Review: Many studies have suggested low nephron endowment at birth contributes to the risk of developing hypertension and chronic kidney disease (CKD) later in life. Loss of nephrons with age and disease is largely a subclinical process. New technologies are needed to count nephrons as glomerular filtration rate (GFR) is a poor surrogate for nephron number.

Redundancy of Progress Notes for Serial Office Visits.

Using sequence alignment to compare more than 12,000 pairs of progress notes, we find that progress notes were, on average, 74.5% redundant with the prior progress note written for the same patient.

Glomerular Volume and Glomerulosclerosis at Different Depths within the Human Kidney.

Background: Age, CKD risk factors, and kidney function are associated with larger glomerular volume and a higher percentage of globally sclerotic glomeruli. Knowledge of how these associations may differ by cortical depth is limited.

Methods: To investigate glomerular volume and glomerulosclerosis across different depths of cortex, we studied wedge sections of the renal parenchyma from 812 patients who underwent a radical nephrectomy (for a tumor), separately characterizing glomeruli in the superficial (subcapsular), middle, and deep (juxtamedullary) regions.

Dose-dependent detoxication of the airborne pollutant benzene in a randomized trial of broccoli sprout beverage in Qidong, China.

Background: Airborne pollutants have collectively been classified as a known human carcinogen and, more broadly, affect the health of hundreds of millions of people worldwide. Benzene is a frequent component of air pollution, and strategies to protect individuals against unavoidable exposure to this and other airborne carcinogens could improve the public's health. Earlier clinical trials in Qidong, China, demonstrated efficacy in enhancing the detoxication of benzene using a broccoli sprout beverage.

Evaluation of inactive Matrix-Gla-Protein (MGP) as a biomarker for incident and recurrent kidney stones.

Background: Matrix-Gla-protein (MGP) is an inhibitor of vascular calcification. Its dephosphorylated and uncarboxylated inactive form, dpucMGP, is a marker of vitamin K status and of cardio-vascular outcomes in chronic kidney disease. We hypothesized that higher serum dpucMGP would be a biomarker of kidney stone disease.

Symptomatic and Radiographic Manifestations of Kidney Stone Recurrence and Their Prediction by Risk Factors: A Prospective Cohort Study.

Background: Meaningful interpretation of changes in radiographic kidney stone burden requires understanding how radiographic recurrence relates to symptomatic recurrence and how established risk factors predict these different manifestations of recurrence.

Methods: We recruited first-time symptomatic stone formers from the general community in Minnesota and Florida. Baseline and 5-year follow-up study visits included computed tomography scans, surveys, and medical record review.

A protocol for measuring the impact of a smoke-free housing policy on indoor tobacco smoke exposure.

Background: Tobacco remains a leading cause of preventable death in the U.S., responsible for more than 440,000 deaths each year.

Metal concentrations in electronic cigarette aerosol: Effect of open-system and closed-system devices and power settings.

Background: Electronic cigarettes (E-cigarettes) generate aerosol containing metal contaminants. Our goals were to quantify aerosol metal concentrations and to compare the effects of power setting and device type (closed-system vs. open-system) on metal release.

Waterpipe tobacco smoke: Characterization of toxicants and exposure biomarkers in a cross-sectional study of waterpipe employees.

Introduction: Few studies have comprehensively characterized toxic chemicals related to waterpipe use and secondhand waterpipe exposure. This cross-sectional study investigated biomarkers of toxicants associated with waterpipe use and passive waterpipe exposure among employees at waterpipe venues.

Method: We collected urine specimens from employees in waterpipe venues from Istanbul, Turkey and Moscow, Russia, and identified waterpipe and cigarette smoking status based on self-report.

Using computer-assisted morphometrics of 5-year biopsies to identify biomarkers of late renal allograft loss.

The current Banff scoring system was not developed to predict graft loss and may not be ideal for use in clinical trials aimed at improving allograft survival. We hypothesized that scoring histologic features of digitized renal allograft biopsies using a continuous, more objective, computer-assisted morphometric (CAM) system might be more predictive of graft loss. We performed a nested case-control study in kidney transplant recipients with a surveillance biopsy obtained 5 years after transplantation.

Vitamin D Status Modifies the Response to Indoor Particulate Matter in Obese Urban Children with Asthma.

Background: Indoor fine particulate air pollution (PM) is linked to asthma morbidity; however, whether vitamin D status influences individual susceptibility to airborne exposures is unclear.

Objective: We aimed to determine if vitamin D modifies the effects of indoor PM on asthma symptoms in urban children.

Methods: A total of 120 children aged 5 to 12 years with physician-diagnosed asthma were evaluated at baseline and every 3 months for 9 months.

Sampling Devices for Indoor Allergen Exposure: Pros and Cons.

Purpose Of Review: To review current indoor allergen sampling devices, including devices to measure allergen in reservoir and airborne dust, and personal sampling devices, with attention to sampling rationale and major indoor allergen size and characteristics.

Recent Findings: While reservoir dust vacuuming samples and airborne dust volumetric air sampling remain popular techniques, recent literature describes sampling using furnace filters and ion-charging devices, both which help to eliminate the need for trained staff; however, variable correlation with reservoir dust and volumetric air sampling has been described. Personal sampling devices include intra-nasal samples and personal volumetric air samples.

Prediction of the Renal Elimination of Drugs With Cystatin C vs Creatinine: A Systematic Review.

Serum cystatin C has been proposed as a kidney biomarker to inform drug dosing. We conducted a systematic review to synthesize available data for the association between serum cystatin C and drug pharmacokinetics, dosing, and clinical outcomes in adults (≥18 years). PubMed, Ovid MEDLINE, Ovid EMBASE, EBSCO CINAHL, and Scopus were systematically searched from 1946 to September 2017 to identify candidate studies.

Larger nephron size, low nephron number, and nephrosclerosis on biopsy as predictors of kidney function after donating a kidney.

It is unclear whether structural findings in the kidneys of living kidney donors predict postdonation kidney function. We studied living kidney donors who had a kidney biopsy during donation. Nephron size was measured by glomerular volume, cortex volume per glomerulus, and mean cross-sectional tubular area.

Indoor air quality in inner-city schools and its associations with building characteristics and environmental factors.

Indoor concentrations of fine particulate matter (PM), nitrogen dioxide (NO), and carbon monoxide (CO) were measured across 16 urban public schools in three different seasons. Exceedance of the WHO guidelines for indoor air was observed, mainly for the hourly average NO concentrations. Seasonal variability was statistically significant for indoor NO and CO concentrations, with higher exposures in fall and winter.

Sarcopenia Index Is a Simple Objective Screening Tool for Malnutrition in the Critically Ill.

Background: Reliable and valid tools to screen for malnutrition in the intensive care unit (ICU) remain elusive. The sarcopenia index (SI) [(serum creatinine/serum cystatin C) × 100], could be an inexpensive, objective tool to predict malnutrition. We evaluated the SI as a screening tool for malnutrition in the ICU and compared it with the modified-NUTRIC score.

Leave no stone unturned: defining recurrence in kidney stone formers.

Purpose Of Review: Established guidelines provide recommendations on the management of kidney stones to prevent recurrence. However, clear and clinically useful terminology for recurrence of kidney stones is needed. This review describes the various manifestations of kidney stone recurrence and the reported rates of kidney stone recurrence in various clinical settings.

Predictors of Symptomatic Kidney Stone Recurrence After the First and Subsequent Episodes.

Objective: To predict symptomatic recurrence among community stone formers with one or more previous stone episodes.

Patients And Methods: A random sample of incident symptomatic kidney stone formers in Olmsted County, Minnesota, was followed for all symptomatic stone episodes resulting in clinical care from January 1, 1984, through January 31, 2017. Clinical and radiographic characteristics at each stone episode predictive of subsequent episodes were identified.