Comparative Analysis of Protein Quantification by the SomaScan Assay versus Orthogonal Methods in Urine from People with Diabetic Kidney Disease.

To our knowledge, calibration curves or other validations for thousands of SomaScan aptamers are not publicly available. Moreover, the abundance of urine proteins obtained from these assays is not routinely validated with orthogonal methods (OMs). We report an in-depth comparison of SomaScan readout for 23 proteins in urine samples from patients with diabetic kidney disease ( = 118) vs OMs, including liquid chromatography-targeted mass spectrometry (LC-MS), ELISA, and nephelometry.

Association of Tubular Solute Clearance with Symptom Burden in Incident Peritoneal Dialysis.

Background And Objectives: Residual kidney function is important to the health and wellbeing of patients with ESKD. We tested whether the kidney clearances of proximal tubular secretory solutes are associated with burden of uremic and heart failure symptoms among patients on peritoneal dialysis with residual kidney function.

Design, Setting, Participants, & Measurements: We enrolled 29 patients on incident peritoneal dialysis with residual urine output >250 ml daily.

Urine RAS components in mice and people with type 1 diabetes and chronic kidney disease.

The pathways implicated in diabetic kidney disease (DKD) are largely derived from animal models. To examine if alterations in renin-angiotensin system (RAS) in humans are concordant with those in rodent models, we measured concentration of angiotensinogen (AOG), cathepsin D (CTSD), angiotensin-converting enzyme (ACE), and ACE2 and enzymatic activities of ACE, ACE2, and aminopeptidase-A in FVB mice 13-20 wk after treatment with streptozotocin ( = 9) or vehicle ( = 15) and people with long-standing type 1 diabetes, with ( = 37) or without ( = 81) DKD. In streptozotocin-treated mice, urine AOG and CTSD were 10.

An Optimized Method for Protein Extraction from OCT-Embedded Human Kidney Tissue for Protein Quantification by LC-MS/MS Proteomics.

The existing biobanks of remnant tissue from clinically indicated kidney biopsies are attractive potential reservoirs for quantification of clinically relevant human tissue proteins by quantitative proteomics. However, a significant caveat of this strategy is that the tissues are often preserved in optimal cutting temperature (OCT) medium. Although OCT is an effective method of preserving the morphologic and immunohistological characteristics of tissues for later study, it significantly impacts efforts to quantify protein expression by liquid chromatography-tandem mass spectrometry methods.

The role of proinsulin and insulin in the diagnosis of insulinoma: a critical evaluation of the Endocrine Society clinical practice guideline.

Context: An end of fast insulin ≥ 3 μIU/mL and a proinsulin concentration ≥ 5 pmol/L have been suggested as useful cutoffs for the diagnosis of insulinoma.

Objective: The main objective was to evaluate the diagnostic performance of an end of fast insulin concentration ≥ 3 μIU/mL and an end of fast proinsulin concentration ≥ 5 pmol/L.

Design: The design was a case-control series.

Insulin resistance is a sufficient basis for hyperandrogenism in lipodystrophic women with polycystic ovarian syndrome.

Context: The lipodystrophies (LD) are characterized by metabolic abnormalities (insulin resistance, hypertriglyceridemia, and diabetes) and a polycystic ovarian syndrome (PCOS) phenotype. Therapeutic administration of leptin improves insulin sensitivity and the metabolic features.

Objective: The objective of the study was to investigate whether the PCOS features are corrected by increasing insulin sensitivity as a function of leptin treatment.