Citations

The arteriovenous fistula (AVF) is the preferred hemodialysis vascular access, but it is complicated by high failure rates and attendant morbidity. This study provides the first description of a murine AVF model that recapitulates two salient features of hemodialysis AVFs, namely, anastomosis of end-vein to side-artery to create the AVF and the presence of chronic kidney disease (CKD). CKD reduced AVF blood flow, observed as early as 3 days after AVF creation, and increased neointimal hyperplasia, venous wall thickness, thrombus formation, and vasculopathic gene expression in the AVF. These adverse effects of CKD could not be ascribed to preexisting alterations in blood pressure or vascular reactivity in this CKD model. In addition to vasculopathic genes, CKD induced potentially vasoprotective genes in the AVF such as heme oxygenase-1 (HO-1) and HO-2. To determine whether prior HO-1 upregulation may protect in this model, we upregulated HO-1 by adeno-associated viral gene delivery, achieving marked venous induction of the HO-1 protein and HO activity. Such HO-1 upregulation improved AVF blood flow and decreased venous wall thickness in the AVF. Finally, we demonstrate that the administration of carbon monoxide, a product of HO, acutely increased AVF blood flow. This study thus demonstrates: 1) the feasibility of a clinically relevant murine AVF model created in the presence of CKD and involving an end-vein to side-artery anastomosis; 2) the exacerbatory effect of CKD on clinically relevant features of this model; and 3) the beneficial effects in this model conferred by HO-1 upregulation by adeno-associated viral gene delivery.

OBJECT Flow-diversion treatment has been shown to be associated with high rates of angiographic obliteration; however, the treatment is relatively contraindicated in the acute phase following subarachnoid hemorrhage (SAH) as these patients require periprocedural dual antiplatelet therapy. Acute coiling followed by flow diversion has emerged as an intriguing and feasible treatment option for ruptured complex and giant aneurysms. In this study the authors report outcomes and complications of patients with ruptured aneurysms undergoing coiling in the acute phase followed by planned delayed flow diversion. METHODS This case series includes patients from 2 institutions. All patients underwent standard endovascular coiling in the acute phase after SAH with the intention and plan to proceed with flow diversion at a later date. Outcomes studied included angiographic occlusion, procedure-related complications, and long-term clinical outcome as measured using the modified Rankin Scale. RESULTS A total of 31 patients underwent coiling in the acute phase with the intention to undergo flow diversion at a later date. The mean aneurysm size was 15.8 ± 7.9 mm. Of the 31 patients undergoing coiling, 4 patients could not undergo further flow-diverter therapy: 3 patients (9.7%) died of complications of subarachnoid hemorrhage and 1 patient had permanent morbidity as a result of perioperative ischemic stroke (3.1%). Twenty-seven patients underwent staged placement of flow diverters after adequate recovery. The median time to treatment was 16 weeks. There was one case of aneurysm rebleeding following coil treatment. There were no cases of permanent morbidity or mortality resulting from flow-diverter treatment. Twenty-four patients underwent imaging follow-up; 18 of these patients had aneurysms that were completely or nearly completely occluded (58.1% on an intent-to-treat basis). At last follow-up (mean 18.3 months), 25 patients had mRS scores ≤ 2 (80.6% on an intent-to-treat basis). CONCLUSIONS Staged treatment of ruptured complex and giant intracranial aneurysms with coiling in the acute phase and flow-diverter treatment following recovery from SAH is both safe and effective. In this series, no cases of rebleeding occurred during the interval between coiling and flow diversion. This strategy should be considered as a valid option in patients presenting with these challenging ruptured aneurysms.

Renovascular hypertension (RVH) is a common cause of both cardiovascular and renal morbidity and mortality. In renal artery stenosis (RAS), atrophy in the stenotic kidney is associated with an influx of macrophages and other mononuclear cells. We tested the hypothesis that chemokine receptor 2 (CCR2) inhibition would reduce chronic renal injury by reducing macrophage influx in the stenotic kidney of mice with RAS. We employed a well-established murine model of RVH to define the relationship between macrophage infiltration and development of renal atrophy in the stenotic kidney. To determine the role of chemokine ligand 2 (CCL2)/CCR2 signaling in the development of renal atrophy, mice were treated with the CCR2 inhibitor RS-102895 at the time of RAS surgery and followed for 4 wk. Renal tubular epithelial cells expressed CCL2 by 3 days following surgery, a time at which no significant light microscopic alterations, including interstitial inflammation, were identified. Macrophage influx increased with time following surgery. At 4 wk, the development of severe renal atrophy was accompanied by an influx of inducible nitric oxide synthase (iNOS)+ and CD206+ macrophages that coexpressed F4/80, with a modest increase in macrophages coexpressing arginase 1 and F4/80. The CCR2 inhibitor RS-102895 attenuated renal atrophy and significantly reduced the number of dual-stained F4/80+ iNOS+ and F4/80+ CD206+ but not F4/80+ arginase 1+ macrophages. CCR2 inhibition reduces iNOS+ and CD206+ macrophage accumulation that coexpress F4/80 and renal atrophy in experimental renal artery stenosis. CCR2 blockade may provide a novel therapeutic approach to humans with RVH.

Abstract MHC, especially HLA-DR3 and HLA-DR2, is one of the most important genetic susceptibility regions for systemic lupus erythematosus. Human studies to understand the role of specific HLA alleles in disease pathogenesis have been hampered by the presence of strong linkage disequilibrium in this region. To overcome this, we produced transgenic mice expressing HLA-DR3 (DRβ1*0301) and devoid of endogenous class II (both I-A and I-E genes, AE0) on a lupus-prone NZM2328 background (NZM2328.DR3+AE0). Both NZM2328 and NZM2328.DR3+AE0 mice developed anti-dsDNA and glomerulonephritis, but anti-dsDNA titers were higher in the latter. Although kidney histological scores were similar in NZM2328 and NZM2328.DR3+AE0 mice (7.2 ± 4.3 and 8.6 ± 5.7, respectively, p = 0.48), the onset of severe proteinuria occurred earlier in NZM2328.DR3+AE0 mice compared with NZM2328 mice (median, 5 and 9 mo respectively, p < 0.001). Periarterial lymphoid aggregates, classic wire loop lesions, and occasional crescents were seen only in kidneys from NZM2328.DR3+AE0 mice. Interestingly, NZM2328.DR3+AE0 mice, but not NZM2328 mice, spontaneously developed anti-Smith (Sm) Abs. The anti-Sm Abs were seen in NZM2328.DR3+AE0 mice that were completely devoid of endogenous class II (AE-/-) but not in mice homozygous (AE+/+) or heterozygous (AE+/−) for endogenous MHC class II. It appears that only HLA-DR3 molecules can preferentially select SmD-reactive CD4+ T cells for generation of the spontaneous anti-Sm immune response. Thus, our mouse model unravels a critical role for HLA-DR3 in generating an autoimmune response to SmD and lupus nephritis in the NZM2328 background.

Background: The best treatment option for patients with Graves' disease (GD) depends on each person's situation and how the differences between the treatment options matter to them in bringing resolution to their illness. The objective of this study was to develop and test an encounter decision tool (GD Choice) for patients and clinicians to engage in shared decision making about the treatment of GD. Methods: GD Choice was developed using an iterative process based on the principles of interaction design and participatory action research. To evaluate the impact of the tool, a controlled before–after study was conducted, assessing the use of GD Choice versus usual care (UC). Results: Sixty-eight patients were enrolled, 37 to UC and 31 to GD Choice. At baseline, the groups were similar. Treatment discussion length was similar in both arms. After their visit, patients in both groups had similar knowledge about the options, except for GD Choice patients knowing significantly more about the complications of treatment (correctly answered by 83% vs. 55%; p = 0.04). Compared with UC, patients in the GD Choice arm had greater involvement in decision making observed on video recordings of clinical encounters (mean OPTION scale score, 35% vs. 30%; p = 0.02), but reported similar levels of decisional comfort and participation in shared decision making. Conclusions: GD Choice increases engagement in the decision-making process and knowledge regarding intervention complications without increasing the length of consultation. These promising results support the conduct of a randomized trial of GD Choice versus UC in a large multicenter trial.

Nicotinic acid–adenine dinucleotide phosphate (NAADP), a molecule derived from β-NADP, has been shown to promote intracellular calcium release in sea urchin eggs. However, there is little information regarding the role of NAADP in the regulation of intracellular calcium fluxes in mammalian cells. We found recently that several mammalian tissues have a high capacity for NAADP synthesis, as assessed by sea urchin egg bioassay. To determine the functional significance of NAADP production by mammalian tissues, we sought to determine whether NAADP is capable of inducing calcium release from microsomes prepared from cultured cells. We found that NAADP, but not β-NADP, activates a specific microsomal calcium release system in mesangial cells isolated from rat kidney; NAADP was without effect in renal tubular epithelial cells. NAADP-induced calcium release is not affected by inhibitors of the inositol 1,4,5-trisphosphate or ryanodine channels. However, NAADP-elicited calcium release was inhibited by L-type calcium channel blockers and by alkaline phosphatase treatment of NAADP. NAADP also promotes specific microsomal calcium release in rat vascular smooth muscle cells, cardiac myocytes, fibroblasts and a human leukaemia cell line, indicating that the capacity for NAADP-induced calcium release is widespread in mammalian cells. We propose that NAADP may be an important regulator of intracellular calcium in many mammalian tissues.

Abstract Supplemental Digital Content is available in the text.

AbstractIn 2006, small blocks of flexible curriculum time, termed selectives, were implemented in the Mayo Medical School preclinical curriculum. Selectives permitted students to pursue professional endeavors, such as research, service, and career exploration, in the preclinical years. The purpose of this study was to survey current and former Mayo medical students regarding the impact of selectives on their research interest and productivity. The authors surveyed 377 current and former Mayo Medical School students from the 2004 to 2014 graduating classes, 154 participants (41% response rate) responded to the survey. The classes were grouped into pre‐ and postselective groups for the comparison studies. Postselective students published significantly more (p = 0.003) and gave significantly more presentations (p = 0.0007) during medical school than preselective students. Thirty‐four (72% of the postselective respondents) indicated that selectives had a strong or very strong impact on their current research interest. Respondents spent an average of 4.0 [3.0–5.0] weeks of Selective time on research, resulting in 1.8 [1.4–2.2] publications and 1.8 [1.4–2.2] presentations, which represented 52.5% [40.0–65.0%] and 47.3% [37.1–57.4%] of the students’ total medical school publications and presentations, respectively. Flexible selective time during the preclinical years results in significantly more medical student academic productivity. © 2015 by The International Union of Biochemistry and Molecular Biology, 43(5):384–390, 2015.