Evaluation of the Order SMARTT: An Initiative to Reduce Phlebotomy and Improve Sleep-Friendly Labs on General Medicine Services.

We assessed the effectiveness of a quality improvement project to reduce routine labs in clinically stable patients, while also promoting sleep-friendly lab timing. The electronic health record was modified with an "Order Sleep" shortcut to facilitate sleep-friendly lab draws. A "4 AM Labs" column was added to electronic patient lists to signal which patients had early morning labs ordered. Among 7,045 patients over 50,951 total patient-days, on average we observed 26.3% fewer routine lab draws per patient-day per week postintervention (4.68 before vs 3.45 after; difference, 1.23; 95% CI, 0.82-1.63; P < .05). In interrupted time series analysis, the "Order Sleep" tool was associated with a significant increase in sleep-friendly lab orders per encounter per week on resident medicine services (intercept, 1.03; standard error (SE), 0.29; P < .001). The "4 AM Labs" column was associated with a significant increase in sleep-friendly lab orders per patient encounter per week on the hospitalist medical service (intercept, 1.17; SE, 0.50; P = .02). We demonstrate the success of an initiative to simultaneously reduce daily labs and improve sleep-friendly ordering.

S100/Calgranulin-mediated inflammation accelerates left ventricular hypertrophy and aortic valve sclerosis in chronic kidney disease in a receptor for advanced glycation end products-dependent manner.

OBJECTIVE: S100A12 and fibroblast growth factor 23 are biomarkers of cardiovascular morbidity and mortality in patients with chronic kidney disease (CKD). We tested the hypothesis that human S100/calgranulin would accelerate cardiovascular disease in mice subjected to CKD. APPROACH AND RESULTS: A bacterial artificial chromosome of the human S100/calgranulin gene cluster containing the genes and regulatory elements for S100A8, S100A9, and S100A12 was expressed in C57BL/6J mouse (hBAC-S100) to generate a novel humanized mouse model. CKD was induced by ureteral ligation, and hBAC-S100 mice and wild-type mice were studied after 10 weeks of chronic uremia. hBAC-S100 mice with CKD showed increased fibroblast growth factor 23 in the hearts, left ventricular hypertrophy, diastolic dysfunction, focal cartilaginous metaplasia, and calcification of the mitral and aortic valve annulus together with aortic valve sclerosis. This phenotype was not observed in wild-type mice with CKD or in hBAC-S100 mice lacking the receptor for advanced glycation end products with CKD, suggesting that the inflammatory milieu mediated by S100/receptor for advanced glycation end products promotes pathological cardiac hypertrophy in CKD. In vitro, inflammatory stimuli including interleukin-6, tumor necrosis factor-α, lipopolysaccarides, or serum from hBAC-S100 mice upregulated fibroblast growth factor 23 mRNA and protein in primary murine neonatal and adult cardiac fibroblasts. CONCLUSIONS: Myeloid-derived human S100/calgranulin is associated with the development of cardiac hypertrophy and ectopic cardiac calcification in a receptor for advanced glycation end products-dependent manner in a mouse model of CKD. We speculate that fibroblast growth factor 23 produced by cardiac fibroblasts in response to cytokines may act in a paracrine manner to accelerate left ventricular hypertrophy and diastolic dysfunction in hBAC-S100 mice with CKD.

Longitudinal changes in MRI markers in a reversible unilateral ureteral obstruction mouse model: preliminary experience.

PURPOSE: To evaluate longitudinal changes in renal oxygenation and diffusion measurements in a model of reversible unilateral ureteral obstruction (rUUO) which has been shown to induce chronic renal functional deficits in a strain dependent way. C57BL/6 mice show higher degree of functional deficit compared with BALB/c mice. Because hypoxia and development of fibrosis are associated with chronic kidney diseases and are responsible for progression, we hypothesized that MRI measurements would be able to monitor the longitudinal changes in this model and will show strain dependent differences in response. Here blood oxygenation level dependent (BOLD) and diffusion MRI measurements were performed at three time points over a 30 day period in mice with rUUO. MATERIALS AND METHODS: The studies were performed on a 4.7T scanner with the mice anesthetized with isoflurane before UUO, 2 and 28 days postrelease of 6 days of obstruction. RESULTS: We found at the early time point (∼2 days after releasing the obstruction), the relative oxygenation in C57Bl/6 mice were lower compared with BALB/c. Diffusion measurements were lower at this time point and reached statistical significance in BALB/c CONCLUSION: These methods may prove valuable in better understanding the natural progression of kidney diseases and in evaluating novel interventions to limit progression.

Contrasting effects of systemic monocyte/macrophage and CD4+ T cell depletion in a reversible ureteral obstruction mouse model of chronic kidney disease.

Using a reversible UUO model (rUUO), we have demonstrated that C57BL/6 mice are susceptible to development of CKD after obstruction-mediated kidney injury while BALB/c mice are resistant. We hypothesized that selective systemic depletion of subpopulations of inflammatory cells during injury or repair might alter the development of CKD. To investigate the impact of modification of Th-lymphocytes or macrophage responses on development of CKD after rUUO, we used an anti-CD4 antibody (GK1.5) or liposomal clodronate to systemically deplete CD4(+) T cells or monocyte/macrophages, respectively, prior to and throughout the rUUO protocol. Flow cytometry and immunohistochemistry confirmed depletion of target cell populations. C57BL/6 mice treated with the GK1.5 antibody to deplete CD4(+) T cells had higher BUN levels and delayed recovery from rUUO. Treatment of C57BL/6 mice with liposomal clodronate to deplete monocyte/macrophages led to a relative protection from CKD as assessed by BUN values. Our results demonstrate that modulation of the inflammatory response during injury and repair altered the susceptibility of C57BL/6 mice to development of CKD in our rUUO model.

Vascular remodeling and arterial calcification are directly mediated by S100A12 (EN-RAGE) in chronic kidney disease.

BACKGROUND: The proinflammatory cytokine S100A12 (also known as EN-RAGE) is associated with cardiovascular morbidity and mortality in hemodialysis patients. In the current study, we tested the hypothesis that S100A12 expressed in vascular smooth muscle in nonatherosclerosis-prone C57BL/6J mice on normal rodent chow diet, but exposed to the metabolic changes of chronic kidney disease (CKD), would develop vascular disease resembling that observed in patients with CKD. METHODS: CKD was induced in S100A12 transgenic mice and wild-type littermate mice not expressing human S100A12 by surgical ligation of the ureters. The aorta was analyzed after 7 weeks of elevated BUN (blood urea nitrogen), and cultured aortic smooth muscle cells were studied. RESULTS: We found enhanced vascular medial calcification in S100A12tg mice subjected to CKD. Vascular calcification was mediated, at least in part, by activation of the receptor for S100A12, RAGE (receptor for advanced glycation endproducts), and by enhanced oxidative stress, since inhibition of NADPH-oxidase Nox1 and limited access of S100A12 to RAGE attenuated the calcification and gene expression of osteoblastic genes in cultured vascular smooth muscle cells. CONCLUSION: S100A12 augments CKD-triggered osteogenesis in murine vasculature, reminiscent of features associated with enhanced vascular calcification in patients with chronic and end-stage kidney disease.

Characterization of novel VEGF (vascular endothelial growth factor)-C splicing isoforms from mouse.

VEGF (vascular endothelial growth factor)-C is a major growth factor implicated in various physiological processes, such as angiogenesis and lymphangiogenesis. In the present paper, we report the identification of three short VEGF-C splicing isoforms (VEGF-C62, VEGF-C129 and VEGF-C184) from immortalized mouse kidney PTECs (proximal tubular epithelial cells). Semi-quantitative RT (reverse transcription)-PCR analysis showed these isoforms were universally expressed to varying degrees in different tissues with high expression levels in the kidney. In immortalized PTECs and podocytes, VEGF-C62 can activate phosphorylation of FAK (focal adhesion kinase) and promote cell adhesion to substratum. Cell survival was also increased by VEGF-C62 treatment in the absence of serum. VEGF-C62 can also reduce cell proliferation in PTECs and podocytes. Nucleolin was one of the proteins that associated with VEGF-C62 in pull-down assays using GST (glutathione transferase) fusion proteins as bait, indicating different protein binding requirements for VEGF-C62 compared with VEGF-C. In conclusion, these newly identified VEGF-C isoforms represent a new class of proteins, which are potentially involved in epithelial cell adhesion and proliferation through novel receptor pathways.

Chronic kidney disease induced in mice by reversible unilateral ureteral obstruction is dependent on genetic background.

Chronic kidney disease (CKD) begins with renal injury; the progression thereafter depends upon a number of factors, including genetic background. Unilateral ureteral obstruction (UUO) is a well-described model of renal fibrosis and as such is considered a model of CKD. We used an improved reversible unilateral ureteral obstruction (rUUO) model in mice to study the strain dependence of development of CKD after obstruction-mediated injury. C57BL/6 mice developed CKD after reversal of three or more days of ureteral obstruction as assessed by blood urea nitrogen (BUN) measurements (>40 mg/dl). In contrast, BALB/c mice were resistant to CKD with up to 10 days ureteral obstruction. During rUUO, C57BL/6 mice exhibited pronounced inflammatory and intrinsic proliferative cellular responses, disruption of renal architecture, and ultimately fibrosis. By comparison, BALB/c mice had more controlled and measured extrinsic and intrinsic responses to injury with a return to normal within several weeks after release of ureteral obstruction. Our findings provide a model that allows investigation of the genetic basis of events during recovery from injury that contribute to the development of CKD.

The many effects of complement C3- and C5-binding proteins in renal injury.

The complement system is an important component of the innate immune system and a modulator of adaptive immunity. The entire complement system is focused on C3 and C5. Thus, there are proteins that activate C3 and C5, those that regulate this activation, and those that transduce the effects of C3 and C5 activation products; each can affect the kidney in renal injury. The normal kidney has the inherent capacity to protect itself from complement activation through cellular expression of decay-accelerating factor, membrane cofactor protein (in human beings), and Crry (in rodents). In addition, plasma factor H protects vascular spaces in the kidney. Although the main function of these proteins is to limit complement activation, there is now considerable evidence that they can transduce signals on engagement in immune cells. The G-protein-coupled 7-span transmembrane receptors for C3a and C5a, and the integral membrane complement receptors (CR) for C3b, iC3b, and C3dg, are expressed outside the kidney, particularly in cells of hematopoietic and immune lineage. These are important in renal injury through their infiltration of the kidney and/or by affecting kidney-directed immune responses. There is mounting evidence that intrinsic glomerular and tubular cell C3aR and C5aR expression and activation also can affect renal injury. CR1 on podocytes and the beta2 integrins CR3 and CR4 in kidney dendritic cells have functions that remain poorly defined. Cells of the kidney also have the capacity to produce and activate their own complement proteins. Thus, intrinsic renal cells express decay-accelerating factor, membrane cofactor protein, Crry, C3aR, C5aR, CR1, CR3, and CR4. These can be engaged by C3 and C5 activation products derived from systemic and local pools in renal injury. Given their capacity to provide signals that influence kidney cellular behavior, their activation can have substantial effects in renal injury. Defining these in a cell- and disease-specific fashion is an exciting challenge for future research.

C5a promotes development of experimental lupus nephritis which can be blocked with a specific receptor antagonist.

The MRL/lpr murine SLE model has widespread complement activation and deposition of complement fragments in affected tissues. The potent anaphylatoxin C5a has the potential to play a key role in the pathogenesis of lupus nephritis. We found that renal expression of C5aR mRNA and protein was significantly increased in MRL/lpr mice compared to control MRL/+ mice. To examine the role of C5a signaling through C5aR, a specific small molecule antagonist (a) of C5aR was administered continuously to MRL/lpr mice from 13 to 19 wks of age. Littermate controls were given vehicle alone. The progressive impairment in renal function exhibited in the control group was prevented by C5aRa treatment. Infiltration of neutrophils and macrophages into kidneys was significantly reduced in animals treated with C5aRa compared to controls. Furthermore, renal expression of IL-1beta and MIP-2 mRNA as well as the extent of apoptosis were significantly decreased with blockade of C5aR, indicating their dependence upon signals delivered through C5aR. Thus, pharmacological blockade of C5aR reduces disease manifestations in experimental lupus nephritis. These data support an important role for the C5a anaphylatoxin in lupus nephritis, and that blockade of C5aR represents a potentially viable treatment for human lupus nephritis.