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Sample records for remnant kidney model

  1. Expression of profibrotic genes in a murine remnant kidney model.

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    Yang, Binxia; Vohra, Pawan K; Janardhanan, Rajiv; Misra, Khamal D; Misra, Sanjay

    2011-12-01

    To test the hypothesis that there is increased expression of several profibrotic genes, including matrix metalloproteinase (MMP)-2 and MMP-9 and tissue inhibitors of metalloproteinase (TIMP-1 and TIMP-2), a disintegrin and metalloproteinase with thrombospondin motif-1 (ADAMTS-1), and fibroblast specific protein-1 (FSP-1) in a murine remnant kidney model. Chronic kidney disease (CKD) was created in 10 C57BL/6 male mice (20-25 g) by performing a right nephrectomy and ligation of the upper pole of the left kidney (remnant kidney). Animals were sacrificed 42 days and 56 days later. Reverse transcriptase polymerase chain reaction (RT-PCR) for MMP-2, MMP-9, TIMP-1, TIMP-2, ADAMTS-1, and FSP-1 was performed in the remnant kidney. Histologic evaluation of the remnant kidney was performed using Ki-67, α-smooth muscle cell actin (α-SMA), hematoxylin and eosin, and Masson' trichrome staining. Kidney function was assessed using serum blood urea nitrogen (BUN) and creatinine. The mean serum BUN and creatinine levels at day 42 and day 56 were significantly higher than baseline (P Masson' trichrome, increased Ki-67, and increased α-SMA staining in the remnant kidney compared with the normal kidney. In the remnant kidney, there was increased fibrosis with increased α-SMA and Ki-67 staining and significantly increased expression of MMP-2, MMP-9, TIMP-1, ADAMTS-1, and FSP-1. Copyright © 2011 SIR. Published by Elsevier Inc. All rights reserved.

  2. The porcine remnant kidney model of chronic renal insufficiency.

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    Misra, Sanjay; Gordon, Jeffery D; Fu, Alex A; Glockner, James F; Chade, Alejandro R; Mandrekar, Jaywant; Lerman, Lilach; Mukhopadhyay, Debabrata

    2006-10-01

    The purpose of the present study was to develop and characterize a porcine model of chronic renal insufficiency created by renal artery embolization. The model was created using 42 castrated juvenile male pigs (7-8 months old) in two parts (pilot (N = 10) group, definitive (N = 26) group, and control group (N = 6). In the pilot group, the embolization procedure was optimized with respect to the size of polyvinyl acrylide (PVA) particles, coils, and amount of kidney embolized. The animals were followed serially for 4 weeks after the embolization procedure to determine the renal function and hypertensive response. In the definitive group, these results were extended to later time points and a left total nephrectomy and a right partial nephrectomy (remnant) were performed and these animals were followed for 28 to 84 days. The kidney function after the embolization was characterized by acute deterioration in renal function, followed by improvement, and "stable" chronic renal insufficiency with statistically significant elevation in creatinine and BUN being observed until day 42. The mean arterial blood pressure remained significantly elevated until day 7 after which it began to decrease to pre-embolization value. The remnant kidney developed fibrosis in the tublointerstitial compartment as it hypertrophied and increased its weight which remained significantly elevated after embolization. A reproducible remnant kidney model of chronic renal insufficiency in pigs was developed. In this model, stable renal insufficiency develops by 4 weeks that lasts until 12 weeks.

  3. Progenitor-like cells derived from mouse kidney protect against renal fibrosis in a remnant kidney model via decreased endothelial mesenchymal transition.

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    Chen, C L; Chou, K J; Fang, H C; Hsu, C Y; Huang, W C; Huang, C W; Huang, C K; Chen, H Y; Lee, P T

    2015-12-02

    Pathophysiological changes associated with chronic kidney disease impair angiogenic processes and increase renal fibrosis. Progenitor-like cells derived from adult kidney have been previously used to promote regeneration in acute kidney injury, even though it remained unclear whether the cells could be beneficial in chronic kidney disease (CKD). In this study, we established a CKD model by five-sixths nephrectomy and mouse kidney progenitor-like cells (MKPCs) were intravenously administered weekly for 5 weeks after establishing CKD. We examined the impact of MKPCs on the progression of renal fibrosis and the potential of MKPCs to preserve the angiogenic process and prevent endothelial mesenchymal transition in vivo and in vitro. Our results demonstrate that the MKPCs delayed interstitial fibrosis and the progression of glomerular sclerosis and ameliorated the decline of kidney function. At 17 weeks, the treated mice exhibited lower blood pressures, higher hematocrit levels, and larger kidney sizes than the control mice. In addition, the MKPC treatment prolonged the survival of the mice with chronic kidney injuries. We observed a decreased recruitment of macrophages and myofibroblasts in the interstitium and the increased tubular proliferation. Notably, MKPC both decreased the level of vascular rarefaction and prevented endothelial mesenchymal transition (EndoMT) in the remnant kidneys. Moreover, the conditioned medium from the MKPCs ameliorated endothelial cell death under hypoxic culture conditions and prevented TGF-β-induced EndoMT through downregulation of phosphorylated Smad 3 in vitro. MKPCs may be a beneficial treatment for kidney diseases characterized by progressive renal fibrosis. The enhanced preservation of angiogenic processes following MKPC injections may be associated with decreased fibrosis in the remnant kidney. These findings provide further understanding of the mechanisms involved in these processes and will help develop new cell

  4. Effects of combination of aliskiren and pentoxyfylline on renal function in the rat remnant kidney model of chronic renal failure.

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    Soni, Hitesh M; Patel, Praful P; Patel, Savan; Rath, Akshyaya C; Acharya, Aviseka; Trivedi, Harshkant D; Jain, Mukul R

    2015-01-01

    The aim was to investigate the nephroprotective effect of combination of aliskiren (ASK), a direct renin inhibitor and pentoxifylline (PTX), inhibitor of tumor necrotic factor-alpha (TNF-alpha), in rat remnant kidney model of chronic kidney disease (CKD). Nephrectomized (NPX) rats were treated with ASK (10 mg/kg, p.o.), PTX (100 mg/kg, p.o.), and combination of PTX + ASK once daily for 28 days. We have performed analysis of various renal injury parameters after 4 weeks of treatment. Treatment with PTX, ASK and combination showed significant improvement in urea, creatinine and total protein in plasma when compared with vehicle treated group in NPX rats. ASK and combination of PTX + ASK elicited significant reduction in blood pressure but PTX alone did not produce blood pressure reduction. ASK treatment showed significant elevation in TNF-alpha, whereas PTX and ASK + PTX showed significant reduction in TNF-alpha in plasma. Histopathologically, the extent of the kidney injury was similar in NPX + vehicle and NPX + ASK-treated rats. PTX and ASK + PTX-treated group showed lesser extent of kidney injury. There was good correlation of mRNA expression levels of kidney injury molecule-1 and bradykinin B1 receptor data with histopathological findings in kidney samples and elevated TNF-alpha levels in plasma. We conclude that combination of PTX + ASK may be better therapeutic intervention for nephroprotection in CKD patients.

  5. [Effect of the ethanol extract of Picrorhiza scrophulariiflora on the progression of chronic kidney disease in a rat remnant kidney model].

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    Feng, Jian-xun; Li, Hong-Yan; Liu, Zhi-qiang; Zhou, Zhan-mei; Tian, Jian-wei; Liang, Min

    2010-07-01

    To investigate the effect of the ethanol extract of Picrorhiza scrophulariiflora (EPS) on renal function and tissue damage in a rat remnant kidney model. Rat models of chronic kidney disease induced by 5/6 nephrectomy (5/6 Nx) were randomly assigned into two groups for treatment with a gavage of either EPS or vehicle for 9 weeks. The rats in the control group received only sham operation. Compared with vehicle-treated 5/6 Nx rats, the EPS-treated rats displayed significantly decreased urinary excretion of malondialdehyde, serum levels of AGEs and AOPPs, and increased serum SeGSHPx activities. These changes were associated with attenuated urinary protein excretion, glomerular sclerosis and interstitial fibrosis. EPS can obviously improve the renal functions and renal pathologies in rats with chronic kidney disease probably by inhibiting the oxidative stress.

  6. Vascular endothelial growth factor-A, matrix metalloproteinase-1, and macrophage migration inhibition factor changes in the porcine remnant kidney model: Evaluation by MRI

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    Misra, Sanjay; Misra, Khamal D; Glockner, James F.

    2010-01-01

    Purpose To determine the expression of vascular endothelial growth factor-A (VEGF-A), macrophage migration inhibition factor (MIF), and matrix metalloproteinase-1 (MMP-1) in the porcine remnant kidney model and quantify renal blood flow and volume using phase contrast magnetic resonance imaging with magnetic resonance angiography (PC MRI/MRA). Material and methods In 23 pigs, the left renal artery was completely embolized using polyvinyl acrylide (PVA) particles and the right kidney partially embolized (remnant kidney) while six pigs served as controls. The animals were sacrificed early (day 3, 7, and 14, N=3), day 24 (D24, N=5), day 37 (D37, N=3), day 42 (D42, N=9), and day 84 (D84, N=3). MRI/PC MRA of the kidneys was performed prior to sacrifice. The remnant and control kidneys were harvested for Western blotting of VEGF-A, MMP-1, and MIF. Blood was removed for BUN and creatinine prior to embolization and at time of sacrifice. Results The kidney function after the embolization was characterized by chronic renal insufficiency. The renal artery blood flow, volume, and weight of the remnant kidney increased significantly over time when compared to controls. At early time points, there was increased expression of MIF and MMP-1 followed by an increase in the expression of VEGF-A by day 37 (Pkidney revealed scarring in the tubulointerstitial space. Conclusions In this model, renal blood flow and volume increase as the remnant kidney hypertrophies and scars. There is increased expression of MIF, VEGF-A, and MMP-1 in the remnant kidney. PMID:20610182

  7. Effect of Hachimijiogan against Renal Dysfunction and Involvement of Hypoxia-Inducible Factor-1α in the Remnant Kidney Model

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    Hiroshi Oka

    2011-01-01

    Full Text Available In chronic renal failure, hypoxia of renal tissue is thought to be the common final pathway leading to end-stage renal failure. In this study the effects of hachimijiogan, a Kampo formula, were studied with respect to hypoxia-inducible factor (HIF. Using remnant kidney rats, we studied the effects of hachimijiogan on renal function in comparison with angiotensin II receptor blocker. The result showed that oral administration of hachimijiogan for seven days suppressed urinary protein excretion and urinary 8-OHdG, a marker of antioxidant activity, equally as well as oral administration of candesartan cilexetil. In contrast, the protein volume of HIF-1α in the renal cortex was not increased in the candesartan cilexetil group, but that in the hachimijiogan group was increased. In immunohistochemical studies as well, the expression of HIF-1α of the high-dose hachimijiogan group increased compared to that of the control group. Vascular endothelial growth factor and glucose transporter 1, target genes of HIF-1α, were also increased in the hachimijiogan group. These results suggest that hachimijiogan produces a protective effect by a mechanism different from that of candesartan cilexetil.

  8. The effect of renal denervation in an experimental model of chronic renal insufficiency, The REmnant kidney Denervation In Pigs study (REDIP study).

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    Lubanda, Jean-Claude; Chochola, Miroslav; Mlček, Mikuláš; Neužil, Petr; Marek, Josef; Havránek, Štěpán; Kuchynková, Sylvie; Fingrová, Zdeňka; Huang, Kao-Hsuan Aimee; Linhart, Aleš

    2017-10-25

    Renal denervation (RDN) is a promising therapeutic method in cardiology. Its currently most investigated indication is resistant hypertension. Other potential indications are atrial fibrillation, type 2 diabetes mellitus and chronic renal insufficiency among others. Previous trials showed conflicting but promising results, but the real benefits of RDN are still under investigation. Patients with renal insufficiency and resistant hypertension are proposed to be a good target for this therapy due to excessive activation of renal sympathetic drive. However, only limited number of studies showed benefits for these patients. We hypothesize that in our experimental model of chronic kidney disease (CKD) due to ischemia with increased activity of the renin-angiotensin-aldosterone system (RAAS), renal denervation can have protective effects by slowing or blocking the progression of renal injury. An experimental biomodel of chronic renal insufficiency induced by ischemia was developed using selective renal artery embolization (remnant kidney porcine model). 27 biomodels were assessed. Renal denervation was performed in 19 biomodels (denervated group), and the remaining were used as controls (n = 8). The extent of renal injury and reparative process between the two groups were compared and assessed using biochemical parameters and histological findings. Viable remnant kidney biomodels were achieved and maintained in 27 swine. There were no significant differences in biochemical parameters between the two groups at baseline. Histological assessment proved successful RDN procedure in all biomodels in the denervated group. Over the 7-week period, there were significant increases in serum urea, creatinine, and aldosterone concentration in both groups. The difference in urea and creatinine levels were not statistically significant between the two groups. However, the level of aldosterone in the denervated was significantly lower in comparison to the controls. Histological

  9. The effect of renal denervation in an experimental model of chronic renal insufficiency, The REmnant kidney Denervation In Pigs study (REDIP study

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    Jean-Claude Lubanda

    2017-10-01

    Full Text Available Abstract Background Renal denervation (RDN is a promising therapeutic method in cardiology. Its currently most investigated indication is resistant hypertension. Other potential indications are atrial fibrillation, type 2 diabetes mellitus and chronic renal insufficiency among others. Previous trials showed conflicting but promising results, but the real benefits of RDN are still under investigation. Patients with renal insufficiency and resistant hypertension are proposed to be a good target for this therapy due to excessive activation of renal sympathetic drive. However, only limited number of studies showed benefits for these patients. We hypothesize that in our experimental model of chronic kidney disease (CKD due to ischemia with increased activity of the renin–angiotensin–aldosterone system (RAAS, renal denervation can have protective effects by slowing or blocking the progression of renal injury. Methods An experimental biomodel of chronic renal insufficiency induced by ischemia was developed using selective renal artery embolization (remnant kidney porcine model. 27 biomodels were assessed. Renal denervation was performed in 19 biomodels (denervated group, and the remaining were used as controls (n = 8. The extent of renal injury and reparative process between the two groups were compared and assessed using biochemical parameters and histological findings. Results Viable remnant kidney biomodels were achieved and maintained in 27 swine. There were no significant differences in biochemical parameters between the two groups at baseline. Histological assessment proved successful RDN procedure in all biomodels in the denervated group. Over the 7-week period, there were significant increases in serum urea, creatinine, and aldosterone concentration in both groups. The difference in urea and creatinine levels were not statistically significant between the two groups. However, the level of aldosterone in the denervated was significantly

  10. Sodium-Glucose Linked Cotransporter-2 Inhibition Does Not Attenuate Disease Progression in the Rat Remnant Kidney Model of Chronic Kidney Disease.

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    Yanling Zhang

    Full Text Available Pharmacological inhibition of the proximal tubular sodium-glucose linked cotransporter-2 (SGLT2 leads to glycosuria in both diabetic and non-diabetic settings. As a consequence of their ability to modulate tubuloglomerular feedback, SGLT2 inhibitors, like agents that block the renin-angiotensin system, reduce intraglomerular pressure and single nephron GFR, potentially affording renoprotection. To examine this further we administered the SGLT2 inhibitor, dapagliflozin, to 5/6 (subtotally nephrectomised rats, a model of progressive chronic kidney disease (CKD that like CKD in humans is characterised by single nephron hyperfiltration and intraglomerular hypertension and where angiotensin converting enzyme inhibitors and angiotensin receptor blockers are demonstrably beneficial. When compared with untreated rats, both sham surgery and 5/6 nephrectomised rats that had received dapagliflozin experienced substantial glycosuria. Nephrectomised rats developed hypertension, heavy proteinuria and declining GFR that was unaffected by the administration of dapagliflozin. Similarly, SGLT2 inhibition did not attenuate the extent of glomerulosclerosis, tubulointerstitial fibrosis or overexpression of the profibrotic cytokine, transforming growth factor-ß1 mRNA in the kidneys of 5/6 nephrectomised rats. While not precluding beneficial effects in the diabetic setting, these findings indicate that SGLT2 inhibition does not have renoprotective effects in this classical model of progressive non-diabetic CKD.

  11. Distal tubule bicarbonate reabsorption in intact and remnant diabetic kidneys.

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    Levine, D Z; Iacovitti, M; Burns, K D

    2000-02-01

    In the diabetic patient, hyperkalemia and hyperchloremic metabolic acidosis has been attributed to one or more of the following factors associated with diabetic nephropathy: hypoaldosteronism, altered potassium homeostasis, or a distal tubular (DT) defect in hydrogen ion secretion. To evaluate maximal in vivo DT acidification in streptozotocin (STZ) diabetes, unidirectional bicarbonate reabsorption (JHCO3) was measured in DTs after acid loading and in surviving DT after 2/3 nephrectomy (Nx). Acid gavage induced hyperchloremic metabolic acidosis in four groups of rats: diabetic rats with hyperglycemia two (a) and (b) eight weeks after STZ injection, (c) diabetic rats with tight glucose control two weeks after STZ injection and insulin pump implantation; and (d) control nondiabetic rats. Another group of diabetic rats underwent (e) Nx one week after STZ injection; these rats were neither acid loaded nor pump implanted. In the acidotic rats, the plasma potassium concentration, the plasma and urine acid-base parameters in the three STZ diabetic groups was not different from control rats, whereas JHCO3 fluxes were brisk without important differences between groups. In Nx rats, although the plasma potassium concentration and acid-base status were normal, surviving JHCO3 fluxes were still brisk and not different from the acid-loaded rats. These in vivo measurements indicate there is no impairment in DT unidirectional bicarbonate reabsorption in the intact or remnant STZ diabetic kidney.

  12. Resveratrol improves mitochondrial function in the remnant kidney from 5/6 nephrectomized rats.

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    Hui, Yan; Lu, Miaomiao; Han, Yarong; Zhou, Hongli; Liu, Wei; Li, Lijing; Jin, Ruixia

    2017-05-01

    Mitochondrial dysfunction is involved in the pathogenesis of chronic kidney disease (CKD). Resveratrol has been demonstrated to be beneficial for the recovery of kidney diseases. In this study, the 5/6 nephrectomized rat was used as a CKD model and the TGF-β1-exposed mouse mesangial cells were used as an in vitro model. Pathological examination showed that resveratrol treatment attenuated glomerular injury in the remnant kidney of 5/6 nephrectomized rat. Additionally, resveratrol improved mitochondrial function in vivo and in vitro, as evidenced by increasing mitochondrial membrane potential, increasing ATP, decreasing reactive oxygen species production and enhancing activities of complex I and III. Furthermore, the dysregulated expressions of electron transport chain proteins and fission/fusion proteins in the kidney of 5/6 nephrectomize rats and TGF-β1-exposed mesangial cells were restored by resveratrol. Finally, upregulated sirt1 and PGC-1α deacetylation were found after treatment with resveratrol in vivo and in vitro, which may contribute to the mitochondrial protective effects of resveratrol. The results demonstrate that resveratrol protects the mitochondria of kidney in 5/6 nephrectomized rats and TGF-β1 induced mesangial cells. The study provides new insights into the renoprotective mechanisms of resveratrol. Copyright © 2017 Elsevier GmbH. All rights reserved.

  13. Modelling the interaction of thermonuclear supernova remnants with circumstellar structures: the case of Tycho's supernova remnant

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    Chiotellis, A.; Kosenko, D.; Schure, K. M.; Vink, J.; Kaastra, J. S.

    2013-10-01

    The well-established Type Ia remnant of Tycho's supernova (SN 1572) reveals discrepant ambient medium-density estimates based on either the measured dynamics or the X-ray emission properties. This discrepancy can potentially be solved by assuming that the supernova remnant (SNR) shock initially moved through a stellar wind bubble, but is currently evolving in the uniform interstellar medium with a relatively low density. We investigate this scenario by combining hydrodynamical simulations of the wind-loss phase and the SNR evolution with a coupled X-ray emission model, which includes non-equilibrium ionization. For the explosion models we use the well-known W7 deflagration model and the delayed detonation model that was previously shown to provide good fits to the X-ray emission of Tycho's SNR. Our simulations confirm that a uniform ambient density cannot simultaneously reproduce the dynamical and X-ray emission properties of Tycho. In contrast, models that considered that the remnant was evolving in a dense, but small, wind bubble reproduce reasonably well both the measured X-ray emission spectrum and the expansion parameter of Tycho's SNR. Finally, we discuss possible mass-loss scenarios in the context of single- and double-degenerate models which possibly could form such a small dense wind bubble.

  14. Modelling the interaction of thermonuclear supernova remnants with circumstellar structures: the case of Tycho's supernova remnant

    NARCIS (Netherlands)

    Chiotellis, A.; Kosenko, D.; Schure, K.M.; Vink, J.; Kaastra, J.S.

    2013-01-01

    The well-established Type Ia remnant of Tycho's supernova (SN 1572) reveals discrepant ambient medium-density estimates based on either the measured dynamics or the X-ray emission properties. This discrepancy can potentially be solved by assuming that the supernova remnant (SNR) shock initially

  15. Ultrasound-Microbubble-Mediated Gene Transfer of Inducible Smad7 Blocks Transforming Growth Factor-β Signaling and Fibrosis in Rat Remnant Kidney

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    Hou, Chun-Cheng; Wang, Wansheng; Huang, Xiao R.; Fu, Ping; Chen, Tso-Hsiao; Sheikh-Hamad, David; Lan, Hui Y.

    2005-01-01

    Transforming growth factor (TGF)-β1 has been shown to play a critical role in hypertensive nephropathy. We hypothesized that blocking TGF-β1 signaling could attenuate renal fibrosis in a rat model of remnant kidney disease. Groups of six rats were subjected to 5/6 nephrectomy and received renal arterial injection of a doxycycline-regulated Smad7 gene or control empty vector using an ultrasound-microbubble-mediated system. Smad7 transgene expression within the kidney was tightly controlled by the addition of doxycycline in the daily drinking water. All animals were euthanized at week 4 for renal functional and histological examination. Hypertension of equivalent magnitude (190 to 200 mmHg) developed in both Smad7- and empty vector-treated rats. However, treatment with Smad7 substantially inhibited Smad2/3 activation and prevented progressive renal injury by inhibiting the rise of 24-hour proteinuria (P < 0.001) and serum creatinine (P < 0.001), preserving creatinine clearance (P < 0.05), and attenuating renal fibrosis and vascular sclerosis such as collagen I and III expression (P < 0.01) and myofibroblast accumulation (P < 0.001). In conclusion, TGF-β/Smad signaling plays a critical role in renal fibrosis in a rat remnant kidney model. The ability of Smad7 to block Smad2/3 activation and attenuate renal and vascular sclerosis demonstrates that ultrasound-mediated Smad7 gene therapy may be a useful therapeutic strategy for the prevention of renal fibrosis in association with hypertension. PMID:15743788

  16. Search and modelling of remnant radio galaxies in the LOFAR Lockman Hole field

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    Brienza, M.; Godfrey, L.; Morganti, R.; Prandoni, I.; Harwood, J.; Mahony, E. K.; Hardcastle, M. J.; Murgia, M.; Röttgering, H. J. A.; Shimwell, T. W.; Shulevski, A.

    2017-10-01

    Context. The phase of radio galaxy evolution after the jets have switched off, often referred to as the remnant phase, is poorly understood and very few sources in this phase are known. Aims: In this work we present an extensive search for remnant radio galaxies in the Lockman Hole, a well-studied extragalactic field. We create mock catalogues of low-power radio galaxies based on Monte Carlo simulations to derive first-order predictions of the fraction of remnants in radio flux limited samples for comparison with our Lockman-Hole sample. Methods: Our search for remnant radio galaxies is based on LOFAR observations at 150 MHz combined with public survey data at higher frequencies. To enhance the selection process, and obtain a more complete picture of the remnant population, we use spectral criteria such as ultra-steep spectral index and high spectral curvature, and morphologre biased toward tinuum: galaxie ical criteria such as low radio core prominence and relaxed shapes to identify candidate remnant radio galaxies. Mock catalogues of radio galaxies are created based on existing spectral and dynamical evolution models combined with observed source properties. Results: We have identified 23 candidate remnant radio galaxies which cover a variety of morphologies and spectral characteristics. We suggest that these different properties are related to different stages of the remnant evolution. We find that ultra-steep spectrum remnants represent only a fraction of our remnant sample suggesting a very rapid luminosity evolution of the radio plasma. Results from mock catalogues demonstrate the importance of dynamical evolution in the remnant phase of low-power radio galaxies to obtain fractions of remnant sources consistent with our observations. Moreover, these results confirm that ultra-steep spectrum remnants represent only a small subset of the entire population ( 50%) when frequencies higher than 1400 MHz are not included in the selection process, and that they are

  17. Onion-shell model for cosmic ray electrons and radio synchrotron emission in supernova remnants

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    Beck, R.; Drury, L. O.; Voelk, H. J.; Bogdan, T. J.

    1985-01-01

    The spectrum of cosmic ray electrons, accelerated in the shock front of a supernova remnant (SNR), is calculated in the test-particle approximation using an onion-shell model. Particle diffusion within the evolving remnant is explicity taken into account. The particle spectrum becomes steeper with increasing radius as well as SNR age. Simple models of the magnetic field distribution allow a prediction of the intensity and spectrum of radio synchrotron emission and their radial variation. The agreement with existing observations is satisfactory in several SNR's but fails in other cases. Radiative cooling may be an important effect, especially in SNR's exploding in a dense interstellar medium.

  18. Are the models for type Ia supernova progenitors consistent with the properties of supernova remnants?,

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    Badenes, C.; Hughes, J.P.; Bravo, E.; Langer, N.

    2007-01-01

    We explore the relationship between the models for progenitor systems of Type Ia supernovae and the properties of the supernova remnants that evolve after the explosion. Most models for Type Ia progenitors in the single-degenerate scenario predict substantial outflows during the presupernova

  19. 3-D Model of Broadband Emission from Supernova Remnants Undergoing Non-linear Diffusive Shock Acceleration

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    Lee, Shiu-Hang; Kamae, Tuneyoshi; Ellison, Donald C.

    2008-07-02

    We present a 3-dimensional model of supernova remnants (SNRs) where the hydrodynamical evolution of the remnant is modeled consistently with nonlinear diffusive shock acceleration occurring at the outer blast wave. The model includes particle escape and diffusion outside of the forward shock, and particle interactions with arbitrary distributions of external ambient material, such as molecular clouds. We include synchrotron emission and cooling, bremsstrahlung radiation, neutral pion production, inverse-Compton (IC), and Coulomb energy-loss. Boardband spectra have been calculated for typical parameters including dense regions of gas external to a 1000 year old SNR. In this paper, we describe the details of our model but do not attempt a detailed fit to any specific remnant. We also do not include magnetic field amplification (MFA), even though this effect may be important in some young remnants. In this first presentation of the model we don't attempt a detailed fit to any specific remnant. Our aim is to develop a flexible platform, which can be generalized to include effects such as MFA, and which can be easily adapted to various SNR environments, including Type Ia SNRs, which explode in a constant density medium, and Type II SNRs, which explode in a pre-supernova wind. When applied to a specific SNR, our model will predict cosmic-ray spectra and multi-wavelength morphology in projected images for instruments with varying spatial and spectral resolutions. We show examples of these spectra and images and emphasize the importance of measurements in the hard X-ray, GeV, and TeV gamma-ray bands for investigating key ingredients in the acceleration mechanism, and for deducing whether or not TeV emission is produced by IC from electrons or pion-decay from protons.

  20. Modeling supernova remnants: effects of diffusive cosmic-ray acceleration on the evolution and application to observations

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    Kosenko, D.; Blinnikov, S.; Vink, J.

    2011-01-01

    We present numerical models for supernova remnant evolution, using a new version of the hydrodynamical code SUPREMNA. We added a cosmic-ray diffusion equation to the code scheme, employing a two-fluid approximation. We investigate the dynamics of the simulated supernova remnants with different

  1. Appraisal of the porcine kidney autotransplantation model

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    Post, Ivo C. J. H.; Dirkes, Marcel C.; Heger, Michal; van Loon, Johannes P. A. M.; Swildens, Bas; Huijzer, Goos M.; van Gulik, Thomas M.

    2012-01-01

    Animal models are extensively used for transplantation related research, especially kidney transplantation. Porcine autotransplantation models are considered to be favorable regarding translatability to the human setting. The key determinants for translatability of the model are discussed,

  2. Appraisal of the porcine kidney autotransplantation model.

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    Post, Ivo C J H; Dirkes, Marcel C; Heger, Michal; van Loon, Johannes P A M; Swildens, Bas; Huijzer, Goos M; van Gulik, Thomas M

    2012-01-01

    Animal models are extensively used for transplantation related research, especially kidney transplantation. Porcine autotransplantation models are considered to be favorable regarding translatability to the human setting. The key determinants for translatability of the model are discussed, comprising animal age, development, anatomy, anesthesia and surgical protocols, and perioperative care. With the detailed discussion of these determinants and the pitfalls in diagnosing animal discomfort, an attempt is made to provide a uniform porcine kidney autotransplantation model with tools to improve currently used models.

  3. Organoids: Modelling polycystic kidney disease

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    Romagnani, Paola

    2017-11-01

    Cysts were generated from organoids in vitro and the removal of adherent cues was shown to play a key role in polycystic kidney disease progression. These cysts resembled those of diseased tissue phenotypically and were capable of remodelling their microenvironment.

  4. The supernova - supernova remnant connection through multi-dimensional magnetohydrodynamic modeling

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    Orlando, S.; Miceli, M.; Petruk, O.; Ono, M.

    2017-10-01

    Supernova remnants (SNRs) are diffuse extended sources often characterized by a rather complex morphology and a highly non-uniform distribution of ejecta. General consensus is that such a morphology reflects, on one hand, pristine structures and features of the progenitor supernova (SN) explosion and, on the other hand, the early interaction of the SN blast wave with the inhomogeneous circumstellar medium (CSM) formed in the latest stages of the progenitor star's evolution. Deciphering X-ray observations of SNRs, therefore, might open the possibility to reconstruct the ejecta structure as it was soon after the SN explosion and the structure and geometry of the medium immediately surrounding the progenitor star. This requires accurate and detailed models which describe the evolution from the on-set of the SN to the full remnant development and which connect the X-ray emission properties of the remnants to the progenitor SNe. Here we show how multi-dimensional SN-SNR magnetohydrodynamic models have been very effective in deciphering X-ray observations of SNR Cassiopeia A and SN 1987A. This has allowed us to unveil the average structure of ejecta in the immediate aftermath of the SN explosion and to constrain the 3D pre-supernova structure and geometry of the environment surrounding the progenitor SN.

  5. A genetic-algorithm-based remnant grey prediction model for energy demand forecasting.

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    Yi-Chung Hu

    Full Text Available Energy demand is an important economic index, and demand forecasting has played a significant role in drawing up energy development plans for cities or countries. As the use of large datasets and statistical assumptions is often impractical to forecast energy demand, the GM(1,1 model is commonly used because of its simplicity and ability to characterize an unknown system by using a limited number of data points to construct a time series model. This paper proposes a genetic-algorithm-based remnant GM(1,1 (GARGM(1,1 with sign estimation to further improve the forecasting accuracy of the original GM(1,1 model. The distinctive feature of GARGM(1,1 is that it simultaneously optimizes the parameter specifications of the original and its residual models by using the GA. The results of experiments pertaining to a real case of energy demand in China showed that the proposed GARGM(1,1 outperforms other remnant GM(1,1 variants.

  6. An angiotensin II type 1 receptor binding molecule has a critical role in hypertension in a chronic kidney disease model.

    Science.gov (United States)

    Kobayashi, Ryu; Wakui, Hiromichi; Azushima, Kengo; Uneda, Kazushi; Haku, Sona; Ohki, Kohji; Haruhara, Kotaro; Kinguchi, Sho; Matsuda, Miyuki; Ohsawa, Masato; Toya, Yoshiyuki; Nishiyama, Akira; Yamashita, Akio; Tanabe, Katsuyuki; Maeshima, Yohei; Umemura, Satoshi; Tamura, Kouichi

    2017-05-01

    Angiotensin II type 1 receptor-associated protein (ATRAP) promotes AT1R internalization along with suppression of hyperactivation of tissue AT1R signaling. Here, we provide evidence that renal ATRAP plays a critical role in suppressing hypertension in a mouse remnant kidney model of chronic kidney disease. The effect of 5/6 nephrectomy on endogenous ATRAP expression was examined in the kidney of C57BL/6 and 129/Sv mice. While 129/Sv mice with a remnant kidney showed decreased renal ATRAP expression and developed hypertension, C57BL/6 mice exhibited increased renal ATRAP expression and resistance to progressive hypertension. Consequently, we hypothesized that downregulation of renal ATRAP expression is involved in pathogenesis of hypertension in the remnant kidney model of chronic kidney disease. Interestingly, 5/6 nephrectomy in ATRAP-knockout mice on the hypertension-resistant C57BL/6 background caused hypertension with increased plasma volume. Moreover, in knockout compared to wild-type C57BL/6 mice after 5/6 nephrectomy, renal expression of the epithelial sodium channel α-subunit and tumor necrosis factor-α was significantly enhanced, concomitant with increased plasma membrane angiotensin II type 1 receptor in the kidneys. Thus, renal ATRAP downregulation is involved in the onset and progression of blood pressure elevation caused by renal mass reduction, and implicates ATRAP as a therapeutic target for hypertension in chronic kidney disease. Copyright © 2016 International Society of Nephrology. Published by Elsevier Inc. All rights reserved.

  7. An association of losartan-hydrochlorothiazide, but not losartan-furosemide, completely arrests progressive injury in the remnant kidney.

    Science.gov (United States)

    Arias, Simone Costa Alarcon; Souza, Renata Alves; Malheiros, Denise Maria Avancini Costa; Fanelli, Camilla; Fujihara, Clarice Kazue; Zatz, Roberto

    2016-01-15

    We have previously shown that an association of losartan and hydrochlorothiazide, initiated 1 mo after 5/6 nephrectomy (Nx), reversed hypertension and albuminuria and promoted lasting renoprotection. In this new study, we investigated whether equal or even better protection could be obtained by combining losartan and furosemide. Nx was performed in 58 Munich-Wistar rats. One month later, tail-cuff pressure and albuminuria were markedly elevated. At this time, Nx rats were distributed among the following four groups: untreated Nx rats, Nx rats that received losartan, Nx rats that received losartan + hydrochlorothiazide, and Nx rats that received losartan + furosemide. Seven months later, Nx rats exhibited high mortality, severe hypertension, albuminuria, glomerulosclerosis, and interstitial fibrosis. Losartan treatment limited mortality and attenuated the renal and hemodynamic abnormalities associated with Nx. As previously shown, the losartan + hydrochlorothiazide association normalized tail-cuff pressure and albumin, prevented renal injury, and reduced mortality to zero. The losartan + furosemide treatment failed to reduce tail-cuff pressure or albumin to normal and prevented renal injury less efficiently than the losartan and hydrochlorothiazide regimen. The reasons for the differing efficacies of the losartan + furosemide and losartan + hydrochlorothiazide schemes are unclear and may include beneficial nondiuretic actions of thiazides, such as vasorelaxation and antiproliferative activity. These results refute the established concept that thiazides and thiazide-like diuretics are ineffective at advanced chronic kidney disease stages. Rather, they suggest that, in view of their renoprotective action, these compounds may even be preferable to loop diuretics in the management of hypertension in advanced chronic kidney disease. Copyright © 2016 the American Physiological Society.

  8. Chronic kidney disease

    OpenAIRE

    de Lusignan, Simon

    2006-01-01

    Glomerular cellular changes such as platelet infiltration, mesangial cell proliferation, increased expression of proinflammatory cytokines and growth factors, as well as tubulointerstitial changes that occur early in the development of the remnant kidney progression and other models of chronic renal insufficiency, were linked to the later development of kidney fibrosis. Nowadays, there is evidence that RAS inhibition, besides the effects on glomerular hemodynamics, influence other pathogenic ...

  9. Triiodothyronine attenuates the progression of renal injury in a rat model of chronic kidney disease.

    Science.gov (United States)

    El Agaty, Sahar Mohamed

    2018-02-06

    This study was designed to investigate whether and how triiodothyronine (T3) affects renal function in an experimental model of chronic kidney disease. Twenty four female rats were divided into: sham operated control group (n=8) , 5/6 nephrectomized group (Nx, n=8) and 5/6 nephrectomized group treated with T3 for 2 weeks (T3-Nx, n=8). T3 administration significantly decreased serum levels of urea, creatinine, tumour necrosis factor alpha, and interleukin-6 compared to Nx group. The levels of malondialdehyde , transforming growth factor beta, fibronectin, and collagen IV as well as the expression of inducible nitric oxide synthase, nuclear factor kappa B, poly ADP ribose polymerase, caspase-3 and Bax all were significantly decreased , though not normalized, in the remnant kidney of T3-Nx group compared to Nx rats. Glutathione, and Heme oxygenase-1 levels as well as the endothelial nitric oxide synthase expression were increased in the remnant kidney of T3-Nx group. Histological studies revealed focal necrosis of renal tubules associated with inflammatory cells infiltration, and fibrosis in Nx group. These changes were alleviated in T3-Nx rats. T3 administration attenuated the clinical and histological signs of renal injury in 5/6 nephrectomized rats by mitigating renal oxidative stress, inflammation, apoptosis as well as fibrosis.

  10. Water Budget Model for a Remnant of the Historic Northern Everglades

    Science.gov (United States)

    Arceneaux, J. C.; Meselhe, E. A.; Habib, E.; Waldon, M. G.

    2006-12-01

    The Arthur R. Marshall Loxahatchee National Wildlife Refuge overlays an area termed Water Conservation Area 1 (WCA-1, a 143,000 acre (58,000 ha) freshwater wetland. It is a remnant of the northern Everglades in Palm Beach County, Florida, USA. Sheetflow that naturally would flow across the Refuge wetlands was disrupted in the 1950s and early 1960s by construction of stormwater pumps, and levees with associated borrow canals which hydraulically isolated the Refuge from its watershed. The U.S. Fish and Wildlife Services (USFWS) concludes that changes in the water quantity, timing, and quality have caused negative impacts to the Refuge ecosystem. It is a top priority of the Refuge to ensure appropriate management that will produce maximum benefits for fish and wildlife, while meeting flood control and water supply needs. Models can improve our understanding and support improvement in these management decisions. The development of a water budget for the Loxahatchee Refuge will provide one useful modeling tool in support of Refuge water management decisions. The water budget model reported here was developed as a double- box (2-compartment) model with a daily time step that predicts temporal variations of water level in the Refuge rim canal and interior marsh based on observed inflows, outflows, precipitation, and evapotranspiration. The water budget model was implemented using Microsoft EXCEL. The model calibration period was from January 1, 1995 to December 31, 1999; the validation period extended from January 1, 2000 to December 31, 2004. Statistical analyses demonstrate the utility of this simple water budget model to predict the temporal variation of water levels in both the Refuge marsh and rim canal. The Refuge water budget model is currently being applied to evaluate various water management scenarios for the Refuge. Preliminary results modeling the mass balance of water quality constituents, including chloride, total phosphorus are encouraging. Success of this

  11. Animal Models for Human Polycystic Kidney Disease

    National Research Council Canada - National Science Library

    NAGAO, Shizuko; KUGITA, Masanori; YOSHIHARA, Daisuke; YAMAGUCHI, Tamio

    2012-01-01

    Polycystic kidney disease (PKD) is a hereditary disorder with abnormal cellular proliferation, fluid accumulation in numerous cysts, remodeling of extracellular matrix, inflammation, and fibrosis in the kidney and liver...

  12. Numerically modelling the Cygnus Loop as a remnant evolved in an anisotropic cavity

    Science.gov (United States)

    Fang, Jun; Yu, Huan; Zhang, Li

    2017-01-01

    The morphology of the middle-aged supernova remnant, Cygnus Loop, seen in X-rays, is peculiar, with a blowout in the south region and other irregular features, such as a bump in the west, a limb with a planar morphology in the east and asymmetry between the east and the west shock profiles of the blowout. The detailed process of the formation of the peculiar profile of the shock is still unclear. We perform three-dimensional hydrodynamical simulations for the remnant to revisit its evolution. In the simulations, the progenitor ejects an anisotropic, latitude-dependent wind, and travels in a direction that is not aligned with the symmetry axis of the wind. As a result, a cavity with a fringed structure is produced. The remnant has evolved in the cavity for about 104 yr. In the north-east, the shock has first encountered the bow shock, and this part corresponds to the bright north-eastern region. The south blowout is formed due to the shock travelling into the undisturbed wind, and the interaction of the shock with the cavity leads to the other peculiar features of the shock structure. The resulting profile of the remnant is consistent with that indicated in X-rays. It can be concluded that the supernova explosion occurred in the cavity produced by an anisotropic stellar wind experiencing two main phases with different wind velocities.

  13. Onion-shell model of cosmic ray acceleration in supernova remnants

    Science.gov (United States)

    Bogdan, T. J.; Volk, H. J.

    1983-01-01

    A method is devised to approximate the spatially averaged momentum distribution function for the accelerated particles at the end of the active lifetime of a supernova remnant. The analysis is confined to the test particle approximation and adiabatic losses are oversimplified, but unsteady shock motion, evolving shock strength, and non-uniform gas flow effects on the accelerated particle spectrum are included. Monoenergetic protons are injected at the shock front. It is found that the dominant effect on the resultant accelerated particle spectrum is a changing spectral index with shock strength. High energy particles are produced in early phases, and the resultant distribution function is a slowly varying power law over several orders of magnitude, independent of the specific details of the supernova remnant.

  14. Postprandial Hyperlipidemia and Remnant Lipoproteins.

    Science.gov (United States)

    Masuda, Daisaku; Yamashita, Shizuya

    2017-02-01

    Fasting hypertriglyceridemia is positively associated with the morbidity of coronary heart disease (CHD), and postprandial (non-fasting) hypertriglyceridemia is also correlated with the risk status for CHD, which is related to the increase in chylomicron (CM) remnant lipoproteins produced from the intestine. CM remnant particles, as well as oxidized low density lipoprotein (LDL) or very low density lipoprotein (VLDL) remnants, are highly atherogenic and act by enhancing systemic inflammation, platelet activation, coagulation, thrombus formation, and macrophage foam cell formation. The cholesterol levels of remnant lipoproteins significantly correlate with small, dense LDL; impaired glucose tolerance (IGT) and CHD prevalence. We have developed an assay of apolipoprotein (apo)B-48 levels to evaluate the accumulation of CM remnants. Fasting apoB-48 levels correlate with the morbidity of postprandial hypertriglyceridemia, obesity, type III hyperlipoproteinemia, the metabolic syndrome, hypothyroidism, chronic kidney disease, and IGT. Fasting apoB-48 levels also correlate with carotid intima-media thickening and CHD prevalence, and a high apoB-48 level is a significant predictor of CHD risk, independent of the fasting TG level. Diet interventions, such as dietary fibers, polyphenols, medium-chain fatty acids, diacylglycerol, and long-chain n-3 polyunsaturated fatty acids (PUFA), ameliorate postprandial hypertriglyceridemia, moreover, drugs for dyslipidemia (n-3 PUFA, statins, fibrates or ezetimibe) and diabetes concerning incretins (dipeptidyl-peptidase IV inhibitor or glucagon like peptide-1 analogue) may improve postprandial hypertriglyceridemia. Since the accumulation of CM remnants correlates to impaired lipid and glucose metabolism and atherosclerotic cardiovascular events, further studies are required to investigate the characteristics, physiological activities, and functions of CM remnants for the development of new interventions to reduce atherogenicity.

  15. Modelling Supernova Remnant kinematics and X-ray emission. Some Examples.

    Science.gov (United States)

    Rosado, M.; Reyes-Iturbide, J.; Sanchez-Cruces, M.; Velazquez, P.; Ambrocio-Cruz, P.; Rodriguez-Gonzalez, A.

    2017-10-01

    Confrontation of MHD numerical simulations of Supernova Remnants (SNRs) with observations of X-ray emission complemented with the kinematics derived also from observations of the optical filaments is very useful. In this work we present some examples of this confrontation and the results we derived for the studied SNRs. The examples are: 1) The SNR CTB 109 (G109-1.0) where the kinematics of the optical filaments allow us to determine that the SNR is in the Perseus Arm of our Galaxy, and 2) The confrontation of the observed X-ray fluxes of the superbubbles N 70 and N 185 in the Large Magellanic Cloud with numerical hidrodynamic simulations that implies that a supernova explosion is also required (besides the action of stellar winds of the interior, massive stars) in order to explain the X-ray fluxes and large velocities derived from the kinematics of their optical filaments.

  16. Novel Transgenic Mouse Model of Polycystic Kidney Disease.

    Science.gov (United States)

    Kito, Yusuke; Saigo, Chiemi; Takeuchi, Tamotsu

    2017-09-01

    Transmembrane protein 207 (TMEM207) is characterized as an important molecule for invasiveness of gastric signet-ring cell carcinoma cells. To clarify the pathobiological effects of TMEM207, we generated 13 transgenic mouse strains, designated C57BL/6-transgenic (Tg) (ITF-TMEM207), where the mouse Tmem207 is ectopically expressed under the proximal promoter of the murine intestinal trefoil factor gene. A C57BL/6-Tg (ITF-TMEM207) mouse strain unexpectedly exhibited a high incidence of spontaneous kidney cysts with histopathological features resembling human polycystic kidney disease, which were found in approximately all mice within 1 year. TMEM207 immunoreactivity was found in noncystic kidney tubules and in renal cysts of the transgenic mice. The ITF-TMEM207 construct was inserted into Mitf at chromosome 6. Cystic kidney was not observed in other C57BL/6-Tg (ITF-TMEM207) transgenic mouse strains. Although several genetically manipulated animal models exist, this mouse strain harboring a genetic mutation in Mitf and overexpression of Tmem207 protein was not reported as a model of polycystic kidney disease until now. This study demonstrates that the C57BL/6-Tg (ITF-TMEM207) mouse may be a suitable model for understanding human polycystic kidney disease. Copyright © 2017 American Society for Investigative Pathology. Published by Elsevier Inc. All rights reserved.

  17. Dynamics and chemistry of vortex remnants in late Arctic spring 1997 and 2000: Simulations with the Chemical Lagrangian Model of the Stratosphere (CLaMS

    Directory of Open Access Journals (Sweden)

    P. Konopka

    2003-01-01

    Full Text Available High-resolution simulations of the chemical composition of the Arctic stratosphere during late spring 1997 and 2000 were performed with the Chemical Lagrangian Model of the Stratosphere (CLaMS. The simulations were performed for the entire northern hemisphere on two isentropic levels 450 K (~18 km and 585 K (~24 km. The spatial distribution and the lifetime of the vortex remnants formed after the vortex breakup in May 1997 display different behavior above and below 20 km. Above 20 km, vortex remnants propagate southward (up to 40°N and are "frozen in'' in the summer circulation without significant mixing. Below 20 km the southward propagation of the remnants is bounded by the subtropical jet. Their lifetime is shorter by a factor of 2 than that above 20 km, owing to significant stirring below this altitude. The behavior of vortex remnants formed in March 2000 is similar but, due to an earlier vortex breakup, dominated during the first 6 weeks after the vortex breakup by westerly winds, even above 20 km. Vortex remnants formed in May 1997 are characterized by large mixing ratios of HCl indicating negligible, halogen-induced ozone loss. In contrast, mid-latitude ozone loss in late boreal spring 2000 is dominated, until mid-April, by halogen-induced ozone destruction within the vortex remnants, and subsequent transport of the ozone-depleted polar air masses (dilution into the mid-latitudes. By varying the intensity of mixing in CLaMS, the impact of mixing on the formation of ClONO2 and ozone depletion is investigated. We find that the photochemical decomposition of HNO3 and not mixing with NOx-rich mid-latitude air is the main source of NOx within the vortex remnants in March and April 2000. Ozone depletion in the remnants is driven by ClOx photolytically formed from ClONO2. At the end of May 1997, the halogen-induced ozone deficit at 450 K poleward of 30°N amounts to ~12% with ~10% in the polar vortex and ~2% in well-isolated vortex remnants

  18. High Intensity Interval Training Favourably Affects Angiotensinogen mRNA Expression and Markers of Cardiorenal Health in a Rat Model of Early-Stage Chronic Kidney Disease

    Directory of Open Access Journals (Sweden)

    Patrick S. Tucker

    2015-01-01

    Full Text Available The majority of CKD-related complications stem from cardiovascular pathologies such as hypertension. To help reduce cardiovascular complications, aerobic exercise is often prescribed. Emerging evidence suggests high intensity interval training (HIIT may be more beneficial than traditional aerobic exercise. However, appraisals of varying forms of aerobic exercise, along with descriptions of mechanisms responsible for health-related improvements, are lacking. This study examined the effects of 8 weeks of HIIT (85% VO2max, versus low intensity aerobic exercise (LIT; 45–50% VO2max and sedentary behaviour (SED, in an animal model of early-stage CKD. Tissue-specific mRNA expression of RAAS-related genes and CKD-related clinical markers were examined. Compared to SED, HIIT resulted in increased plasma albumin (p=0.001, reduced remnant kidney weight (p=0.028, and reduced kidney weight-body weight ratios (p=0.045. Compared to LIT, HIIT resulted in reduced Agt mRNA expression (p=0.035, reduced plasma LDL (p=0.001, triglycerides (p=0.029, and total cholesterol (p=0.002, increased plasma albumin (p=0.047, reduced remnant kidney weight (p=0.005, and reduced kidney weight-body weight ratios (p=0.048. These results suggest HIIT is a more potent regulator of several markers that describe and influence health in CKD.

  19. A spatially-averaged mathematical model of kidney branching morphogenesis

    KAUST Repository

    Zubkov, V.S.

    2015-08-01

    © 2015 Published by Elsevier Ltd. Kidney development is initiated by the outgrowth of an epithelial ureteric bud into a population of mesenchymal cells. Reciprocal morphogenetic responses between these two populations generate a highly branched epithelial ureteric tree with the mesenchyme differentiating into nephrons, the functional units of the kidney. While we understand some of the mechanisms involved, current knowledge fails to explain the variability of organ sizes and nephron endowment in mice and humans. Here we present a spatially-averaged mathematical model of kidney morphogenesis in which the growth of the two key populations is described by a system of time-dependant ordinary differential equations. We assume that branching is symmetric and is invoked when the number of epithelial cells per tip reaches a threshold value. This process continues until the number of mesenchymal cells falls below a critical value that triggers cessation of branching. The mathematical model and its predictions are validated against experimentally quantified C57Bl6 mouse embryonic kidneys. Numerical simulations are performed to determine how the final number of branches changes as key system parameters are varied (such as the growth rate of tip cells, mesenchyme cells, or component cell population exit rate). Our results predict that the developing kidney responds differently to loss of cap and tip cells. They also indicate that the final number of kidney branches is less sensitive to changes in the growth rate of the ureteric tip cells than to changes in the growth rate of the mesenchymal cells. By inference, increasing the growth rate of mesenchymal cells should maximise branch number. Our model also provides a framework for predicting the branching outcome when ureteric tip or mesenchyme cells change behaviour in response to different genetic or environmental developmental stresses.

  20. Unraveling the genetics of chronic kidney disease using animal models

    NARCIS (Netherlands)

    Korstanje, Ron; DiPetrillo, K.

    2004-01-01

    Identifying genes underlying common forms of kidney disease in humans has proven difficult, expensive, and time consuming. Quantitative trait loci (QTL) for several complex traits are concordant among mice, rats, and humans, suggesting that genetic findings from these animal models are relevant to

  1. Practical application of stereological kidney methods in experimental animal models

    Directory of Open Access Journals (Sweden)

    María Teresa Fernández García

    2017-01-01

    Full Text Available The kidneys are vital organs responsible for excretion, fluid and electrolyte balance and hormone production. The nephrons are the kidney's functional and structural units. The number, size and distribution of the nephron components contain relevant information on renal function. Stereology is a branch of morphometry that applies mathematical principles to obtain three-dimensional information from serial, parallel and equidistant two-dimensional microscopic sections. Because of the complexity of stereological studies and the lack of scientific literature on the subject, the aim of this paper is to clearly explain, through animal models, the basic concepts of stereology and how to calculate the main kidney stereological parameters that can be applied in future experimental studies.

  2. When Disorder Looks Like Order: A New Model to Explain Radial Magnetic Fields in Young Supernova Remnants

    Energy Technology Data Exchange (ETDEWEB)

    West, J. L.; Gaensler, B. M. [Dunlap Institute for Astronomy and Astrophysics University of Toronto, Toronto, ON M5S 3H4 (Canada); Jaffe, T. [CRESST, NASA Goddard Space Flight Center, Greenbelt, MD 20771 (United States); Ferrand, G. [RIKEN, Astrophysical Big Bang Laboratory, Wako, Saitama-ken (Japan); Safi-Harb, S., E-mail: jennifer.west@dunlap.utoronto.ca [Department of Physics and Astronomy, University of Manitoba, Winnipeg, MB R3T 2N2 (Canada)

    2017-11-10

    Radial magnetic fields are observed in all known young, shell-type supernova remnants in our Galaxy, including Cas A, Tycho, Kepler, and SN1006, and yet the nature of these radial fields has not been thoroughly explored. Using a 3D model, we consider the existence and observational implications of an intrinsically radial field. We also present a new explanation of the origin of the radial pattern observed from polarization data as resulting from a selection effect due to the distribution of cosmic-ray electrons (CREs). We show that quasi-parallel acceleration can concentrate CREs at regions where the magnetic field is radial, making a completely turbulent field appear ordered, when it is in fact disordered. We discuss observational properties that may help distinguish between an intrinsically radial magnetic field and the case where it only appears radial due to the CRE distribution. We also show that the case of an intrinsically radial field with a quasi-perpendicular CRE acceleration mechanism has intriguing similarities to the observed polarization properties of SN1006.

  3. Measurement and stochastic modeling of kidney puncture forces.

    Science.gov (United States)

    van Gerwen, D J; Dankelman, J; van den Dobbelsteen, J J

    2014-03-01

    The development of needle insertion robots and training simulators requires knowledge of the forces that arise when a needle is inserted into soft-tissue. The present study aims to construct stochastic models of the force required to puncture a kidney using a trocar needle, based on measurements. To this end, a total of sixty insertions were performed into porcine kidneys (ex vivo), at constant speed, using a linear motion stage. Axial force was measured at the needle hub and an ultrasound probe moved with the needle to enable identification of anatomical structures. Two force peaks were observed for each tissue layer punctured, one caused by the tip and one by the edge of the cannula. Based on ultrasound data these double-peaks were classified into four groups, related to kidney capsule and internal structures. Group size varied from 7 to 55 double-peaks. Force peaks in each group were evaluated in terms of peak force and drop in force for both tip and cannula, and stochastic models were constructed that describe the multivariate distribution of these metrics. Peak forces in the capsule and internal structures ranged up to 2 N and 8 N, respectively. The resulting models can be used to simulate kidney puncture events in a variety of applications.

  4. Non-Transgenic Mouse Models of Kidney Disease.

    Science.gov (United States)

    Rabe, Michael; Schaefer, Franz

    2016-01-01

    Animal models are essential tools to understand the mechanisms underlying the development and progression of renal disease and to study potential therapeutic approaches. Recently, interventional models suitable to induce acute and chronic kidney disease in the mouse have become a focus of interest due to the wide availability of genetically engineered mouse lines. These models differ by their damaging mechanism (cell toxicity, immune mechanisms, surgical renal mass reduction, ischemia, hypertension, ureter obstruction etc.), functional and histomorphological phenotype and disease evolution. The susceptibility to a damaging mechanism often depends on strain and gender. The C57BL/6 strain, the most commonly used genetic background of transgenic mice, appears to be relatively resistant against developing glomerulosclerosis, proteinuria and hypertension. This review serves to provide a comprehensive overview of interventional mouse models of acute and chronic kidney disease. © 2016 S. Karger AG, Basel.

  5. Genetic kidney diseases: Caenorhabditis elegans as model system.

    Science.gov (United States)

    Ganner, Athina; Neumann-Haefelin, Elke

    2017-07-01

    Despite its apparent simplicity, the nematode Caenorhabditis elegans has a high rating as a model in molecular and developmental biology and biomedical research. C. elegans has no excretory system comparable with the mammalian kidney but many of the genes and molecular pathways involved in human kidney diseases are conserved in C. elegans. The plethora of genetic, molecular and imaging tools available in C. elegans has enabled major discoveries in renal research and advanced our understanding of the pathogenesis of genetic kidney diseases. In particular, studies in C. elegans have pioneered the fundamental role of cilia for cystic kidney diseases. In addition, proteins of the glomerular filtration barrier and podocytes are critical for cell recognition, assembly of functional neuronal circuits, mechanosensation and signal transduction in C. elegans. C. elegans has also proved tremendously valuable for aging research and the Von Hippel-Lindau tumor suppressor gene has been shown to modulate lifespan in the nematode. Further, studies of the excretory canal, membrane transport and ion channel function in C. elegans have provided insights into mechanisms of tubulogenesis and cellular homeostasis. This review recounts the way that C. elegans can be used to investigate various aspects of genetic and molecular nephrology. This model system opens up an exciting and new area of study of renal development and diseases.

  6. Hydrodynamic evolution of neutron star merger remnants

    Science.gov (United States)

    Liu, Men-Quan; Zhang, Jie

    2017-11-01

    Based on the special relativistic hydrodynamic equations and updated cooling function, we investigate the long-term evolution of neutron stars merger (NSM) remnants by a one-dimensional hydrodynamic code. Three NSM models from one soft equation of state, SFHo, and two stiff equations of state, DD2 and TM1, are used to compare their influences on the hydrodynamic evolution of remnants. We present the luminosity, mass and radius of remnants, as well as the velocity, temperature and density of shocks. For a typical interstellar medium (ISM) density with solar metallicity, we find that the NSM remnant from the SFHo model makes much more changes to ISM in terms of velocity, density and temperature distributions, compared with the case of DD2 and TM1 models. The maximal luminosity of the NSM remnant from the SFHo model is 3.4 × 1038 erg s-1, which is several times larger than that from DD2 and TM1 models. The NSM remnant from the SFHo model can maintain high luminosity (>1038 erg s-1) for 2.29 × 104 yr. Furthermore, the density and temperature of remnants at the maximal luminosity are not sensitive to the power of the original remnant. For the ISM with the solar metallicity and nH = 1 cm- 3, the density of the first shock ˜10-23 g cm-3 and the temperature ˜3 × 105 K in the maximal luminosity phase; The temperature of the first shock decreases and there is a thin `dense' shell with density ˜10-21 g cm-3 after the maximal luminosity. These characteristics may be helpful for future observations of NSM remnants.

  7. Antiprotons Produced in Supernova Remnants

    OpenAIRE

    Berezhko, E. G.; Ksenofontov, L. T.

    2014-01-01

    We present the energy spectrum of antiproton cosmic ray (CR) component calculated on the basis of the nonlinear kinetic model of CR production in supernova remnants (SNR). The model includes reacceleration of already existing in interstellar medium antiprotons as well as creation of antiprotons in nuclear collisions of accelerated protons with gas nuclei and their subsequent acceleration by SNR shock. It is shown that antiprotons production in SNRs produces considerable effect in their result...

  8. A possible zebrafish model of polycystic kidney disease: knockdown of wnt5a causes cysts in zebrafish kidneys.

    Science.gov (United States)

    Huang, Liwei; Xiao, An; Wecker, Andrea; McBride, Daniel A; Choi, Soo Young; Zhou, Weibin; Lipschutz, Joshua H

    2014-12-02

    Polycystic kidney disease (PKD) is one of the most common causes of end-stage kidney disease, a devastating disease for which there is no cure. The molecular mechanisms leading to cyst formation in PKD remain somewhat unclear, but many genes are thought to be involved. Wnt5a is a non-canonical glycoprotein that regulates a wide range of developmental processes. Wnt5a works through the planar cell polarity (PCP) pathway that regulates oriented cell division during renal tubular cell elongation. Defects of the PCP pathway have been found to cause kidney cyst formation. Our paper describes a method for developing a zebrafish cystic kidney disease model by knockdown of the wnt5a gene with wnt5a antisense morpholino (MO) oligonucleotides. Tg(wt1b:GFP) transgenic zebrafish were used to visualize kidney structure and kidney cysts following wnt5a knockdown. Two distinct antisense MOs (AUG - and splice-site) were used and both resulted in curly tail down phenotype and cyst formation after wnt5a knockdown. Injection of mouse Wnt5a mRNA, resistant to the MOs due to a difference in primary base pair structure, rescued the abnormal phenotype, demonstrating that the phenotype was not due to "off-target" effects of the morpholino. This work supports the validity of using a zebrafish model to study wnt5a function in the kidney.

  9. Knockdown of bicaudal C in zebrafish (Danio rerio) causes cystic kidneys: a nonmammalian model of polycystic kidney disease.

    Science.gov (United States)

    Bouvrette, Denise J; Sittaramane, Vinoth; Heidel, Jerry R; Chandrasekhar, Anand; Bryda, Elizabeth C

    2010-04-01

    Polycystic kidney disease (PKD) is one of the leading causes of end-stage renal disease in humans and is characterized by progressive cyst formation, renal enlargement, and abnormal tubular development. Currently, there is no cure for PKD. Although a number of PKD genes have been identified, their precise role in cystogenesis remains unclear. In the jcpk mouse model of PKD, mutations in the bicaudal C gene (Bicc1) are responsible for the cystic phenotype; however, the function of Bicc1 is unknown. In this study, we establish an alternative, nonmammalian zebrafish model to study the role of Bicc1 in PKD pathogenesis. Antisense morpholinos were used to evaluate loss of Bicc1 function in zebrafish. The resulting morphants were examined histologically for kidney cysts and structural abnormalities. Immunostaining and fluorescent dye injection were used to evaluate pronephric cilia and kidney morphogenesis. Knockdown of zebrafish Bicc1 expression resulted in the formation of kidney cysts; however, defects in kidney structure or pronephric cilia were not observed. Importantly, expression of mouse Bicc1 rescues the cystic phenotype of the morphants. These results demonstrate that the function of Bicc1 in the kidney is evolutionarily conserved, thus supporting the use of zebrafish as an alternative in vivo model to study the role of mammalian Bicc1 in renal cyst formation.

  10. Pulsar/Supernova Remnant Associations

    Science.gov (United States)

    Kaspi, Victoria M.

    1996-01-01

    We list and review proposed pulsar/supernova remnant associations, summarize recent highlights in the field, including searches for young pulsars, searches for remnants, recent studies of previously proposed associations, and attempts at pulsar/remnant association synthesis. we argue that most proposed pulsar/supernova remnant associations require additional investigation before they can be considered secure, and we suggest directions for future work.

  11. Kidney compartment model. [Mathematical model for iodohippurate distribution as a function of time

    Energy Technology Data Exchange (ETDEWEB)

    Gullberg, G.T.

    1976-09-01

    A multiparameter kidney compartment model which quantitates the amount of iodohippurate concentration as a function of time in the blood, tissue, kidneys and bladder is developed from a system of differential equations which represent first order kinetics. The kinetic data are obtained using a gamma camera and an HP5407 computer system which allows one to delineate areas of interest for the blood and tissue, kidneys, and bladder thus separating the data into four data sets. The estimated tubular transit times have a high ratio of the signal to the variance whereas the estimates of the amount of iodohippurate in the blood, tissue and kidneys have a low ratio of the signal to the variance. Application of this model to patient data requires better statistics than available with conventional /sup 131/I-hippurate doses; thus a true test of the efficacy awaits availability of /sup 123/I-hippurate.

  12. A modified elliptical formula to estimate kidney collagen content in a model of chronic kidney disease.

    Science.gov (United States)

    Nieto, Jake A; Zhu, Janice; Duan, Bin; Li, Jingsong; Zhou, Ping; Paka, Latha; Yamin, Michael A; Goldberg, Itzhak D; Narayan, Prakash

    2018-01-01

    The extent of scarring or renal interstitial collagen deposition in chronic kidney disease (CKD) can only be ascertained by highly invasive, painful and sometimes risky, tissue biopsy. Interestingly, while CKD-related abnormalities in kidney size can often be visualized using ultrasound, not only does the ellipsoid formula used today underestimate true renal size, but the calculated renal size does not inform tubulointerstitial collagen content. We used coronal kidney sections from healthy mice and mice with kidney disease to develop a new formula for estimating renal parenchymal area. While treating the kidney as an ellipse with the major axis (a) the polar distance, this technique involves extending the minor axis (b) into the renal pelvis to obtain a new minor axis, be. The calculated renal parenchymal area is remarkably similar to the true or measured area. Biochemically determined kidney collagen content revealed a strong and positive correlation with the calculated renal parenchymal area. Picrosirius red staining for tubulointerstitial collagen also correlated with calculated renal parenchymal area. The extent of renal scarring, i.e. kidney interstitial collagen content, can now be computed by making just two axial measurements which can easily be accomplished via noninvasive imaging of this organ.

  13. Using an isolated rat kidney model to identify kidney origin proteins in urine.

    Directory of Open Access Journals (Sweden)

    Lulu Jia

    Full Text Available The use of targeted proteomics to identify urinary biomarkers of kidney disease in urine can avoid the interference of serum proteins. It may provide better sample throughput, higher sensitivity, and specificity. Knowing which urinary proteins to target is essential. By analyzing the urine from perfused isolated rat kidneys, 990 kidney origin proteins with human analogs were identified in urine. Of these proteins, 128 were not found in normal human urine and may become biomarkers with zero background. A total of 297 proteins were not found in normal human plasma. These proteins will not be influenced by other normal organs and will be kidney specific. The levels of 33 proteins increased during perfusion with an oxygen-deficient solution compared to those perfused with oxygen. The 75 proteins in the perfusion-driven urine have a significantly increased abundance ranking compared to their ranking in normal human urine. When compared with existing candidate biomarkers, over ninety percent of the kidney origin proteins in urine identified in this study have not been examined as candidate biomarkers of kidney diseases.

  14. Evolution of Supernova Remnants

    Science.gov (United States)

    Arbutina, B.

    2017-12-01

    This book, both a monograph and a graduate textbook, is based on my original research and partly on the materials prepared earlier for the 2007 and 2008 IARS Astrophysics Summer School in Istanbul, AstroMundus course 'Supernovae and Their Remnants' that was held for the first time in 2011 at the Department of Astronomy, Faculty of Mathematics, University of Belgrade, and a graduate course 'Evolution of Supernova Remnants' that I teach at the aforementioned university. The first part Supernovae (introduction, thermonuclear supernovae, core-collapse supernovae) provides introductory information and explains the classification and physics of supernova explosions, while the second part Supernova remnants (introduction, shock waves, cosmic rays and particle acceleration, magnetic fields, synchrotron radiation, hydrodynamic and radio evolution of supernova remnants), which is the field I work in, is more detailed in scope i.e. technical/mathematical. Special attention is paid to details of mathematical derivations that often cannot be found in original works or available literature. Therefore, I believe it can be useful to both, graduate students and researchers interested in the field.

  15. Nonthermal Emission of Supernova Remnant SN 1006 Revisited: Theoretical Model and the H.E.S.S. Results

    Science.gov (United States)

    Berezhko, E. G.; Ksenofontov, L. T.; Völk, H. J.

    2012-11-01

    The properties of the Galactic supernova remnant (SNR) SN 1006 are theoretically re-analyzed in light of the recent H.E.S.S. results. Nonlinear kinetic theory is used to determine the momentum spectrum of cosmic rays (CRs) in space and time in the supernova remnant SN 1006. The physical parameters of the model—proton injection rate, electron-to-proton ratio, and downstream magnetic field strength—are determined through a fit of the result to the observed spatially integrated synchrotron emission properties. The only remaining unknown astronomical parameter, the circumstellar gas number density, is determined by a normalization of the amplitude of the γ-ray flux to the observed amplitude. The bipolar morphology of both nonthermal X-ray and γ-ray emissions is explained by the preferential injection of suprathermal nuclei and subsequent magnetic field amplification in the quasi-parallel regions of the outer supernova shock. The above parameters provide an improved fit to all existing nonthermal emission data, including the TeV emission spectrum recently detected by H.E.S.S., with the circumstellar hydrogen gas number density N H ≈ 0.06 cm-3 close to values derived from observations of thermal X-rays. The hadronic and leptonic γ-ray emissions are of comparable strength. The overall energy of accelerated CRs at the present epoch is of the order of 5% of the total hydrodynamic explosion energy, and is predicted to rise with time by a factor of ≈2. The relevance of CR escape from the SNR for the spectrum of the γ-ray emission is demonstrated. The sum of the results suggests that SN 1006 is a CR source with a high efficiency of nuclear CR production, as required for the Galactic CR sources, both in flux as well as in cutoff energy.

  16. New rat model that phenotypically resembles autosomal recessive polycystic kidney disease

    NARCIS (Netherlands)

    J. Nauta (Jeroen); M.A. Goedbloed (Miriam); H.V. Herck; D.A. Hesselink (Dennis); P. Visser (Pim); R. Willemsen (Rob); R.P.E. van Dokkum (Richard); C.J. Wright; L.M. Guay-Woodford

    2000-01-01

    textabstractNumerous murine models of polycystic kidney disease (PKD) have been described. While mouse models are particularly well suited for investigating the molecular pathogenesis of PKD, rats are well established as an experimental model of renal physiologic

  17. Precision-cut human kidney slices as a model to elucidate the process of renal fibrosis

    NARCIS (Netherlands)

    Stribos, Elisabeth G D; Luangmonkong, Theerut; Leliveld, Anna M.; de Jong, Igle J; van Son, Willem J; Hillebrands, Jan-Luuk; Seelen, Marc A.; van Goor, Harry; Olinga, Peter; Mutsaers, Henricus A M

    Chronic kidney disease is a major health concern, and experimental models bridging the gap between animal studies and clinical research are currently lacking. Here, we evaluated precision-cut kidney slices (PCKSs) as a potential model for renal disease. PCKSs were prepared from human cortical tissue

  18. Red yeast rice repairs kidney damage and reduces inflammatory transcription factors in rat models of hyperlipidemia

    OpenAIRE

    DING, MEI; SI, DAOYUAN; ZHANG, WENQI; FENG, ZHAOHUI; HE, MIN; YANG, PING

    2014-01-01

    Xuezhikang (XZK), an extract of red yeast rice, has been widely used for the management of hyperlipidemia and coronary heart disease (CHD); however, the effects of XZK treatment on kidney injury have not yet been fully identified. The aim of the current study was to evaluate the effects of XZK on the kidneys and investigate the related mechanisms in a rat model of hyperlipidemia. Thus, the effect on inflammatory transcription factors and kidney damage was investigated with in vitro and in viv...

  19. Early chronic kidney disease: diagnosis, management and models of care

    Science.gov (United States)

    Wouters, Olivier J.; O'Donoghue, Donal J.; Ritchie, James; Kanavos, Panos G.; Narva, Andrew S.

    2015-01-01

    Chronic kidney disease (CKD) is a prevalent condition in many countries, and it is estimated that over $1 trillion is spent globally on end-stage renal disease (ESRD) care. There is a clear clinical and economic rationale for designing timely and appropriate health system responses to limit progression from CKD to ESRD. This article reviews the gaps in our knowledge about which early CKD interventions are appropriate, the optimal time to intervene, and what model of care to adopt. The available diagnostic tests exhibit key limitations. Clinical care may improve if early-stage (1–3) CKD with risk for progression towards ESRD is differentiated from early CKD that is unlikely to advance. It is possible that CKD should be re-conceptualized as a part of primary care. Additional research is needed to better understand the risk factors for CKD progression. Systems modelling can be used to evaluate the impact of different care models on CKD outcomes and costs. The US Indian Health Service experience has demonstrated that an integrated, system-wide approach, even in an underfunded system, can produce significant benefits. PMID:26055354

  20. Axl tyrosine kinase protects against tubulo-interstitial apoptosis and progression of renal failure in a murine model of chronic kidney disease and hyperphosphataemia.

    Science.gov (United States)

    Hyde, Gareth D; Taylor, Rebecca F; Ashton, Nick; Borland, Samantha J; Wu, Hon Sing Geoffrey; Gilmore, Andrew P; Canfield, Ann E

    2014-01-01

    Chronic kidney disease (CKD) is defined as the progressive loss of renal function often involving glomerular, tubulo-interstitial and vascular pathology. CKD is associated with vascular calcification; the extent of which predicts morbidity and mortality. However, the molecular regulation of these events and the progression of chronic kidney disease are not fully elucidated. To investigate the function of Axl receptor tyrosine kinase in CKD we performed a sub-total nephrectomy and fed high phosphate (1%) diet to Axl+/+ and Axl-/- mice. Plasma Gas6 (Axl' ligand), renal Axl expression and downstream Akt signalling were all significantly up-regulated in Axl+/+ mice following renal mass reduction and high phosphate diet, compared to age-matched controls. Axl-/- mice had significantly enhanced uraemia, reduced bodyweight and significantly reduced survival following sub-total nephrectomy and high phosphate diet compared to Axl+/+ mice; only 45% of Axl-/- mice survived to 14 weeks post-surgery compared to 87% of Axl+/+ mice. Histological analysis of kidney remnants revealed no effect of loss of Axl on glomerular hypertrophy, calcification or renal sclerosis but identified significantly increased tubulo-interstitial apoptosis in Axl-/- mice. Vascular calcification was not induced in Axl+/+ or Axl-/- mice in the time frame we were able to examine. In conclusion, we identify the up-regulation of Gas6/Axl signalling as a protective mechanism which reduces tubulo-interstitial apoptosis and slows progression to end-stage renal failure in the murine nephrectomy and high phosphate diet model of CKD.

  1. Knockdown of Bicaudal C in Zebrafish (Danio rerio) Causes Cystic Kidneys: A Nonmammalian Model of Polycystic Kidney Disease

    OpenAIRE

    Bouvrette, Denise J; Sittaramane, Vinoth; Heidel, Jerry R.; Chandrasekhar, Anand; Bryda, Elizabeth C.

    2010-01-01

    Polycystic kidney disease (PKD) is one of the leading causes of end-stage renal disease in humans and is characterized by progressive cyst formation, renal enlargement, and abnormal tubular development. Currently, there is no cure for PKD. Although a number of PKD genes have been identified, their precise role in cystogenesis remains unclear. In the jcpk mouse model of PKD, mutations in the bicaudal C gene (Bicc1) are responsible for the cystic phenotype; however, the function of Bicc1 is unk...

  2. ANTIPROTONS PRODUCED IN SUPERNOVA REMNANTS

    Energy Technology Data Exchange (ETDEWEB)

    Berezhko, E. G.; Ksenofontov, L. T., E-mail: ksenofon@ikfia.sbras.ru [Yu. G. Shafer Institute of Cosmophysical Research and Aeronomy, 31 Lenin Avenue, 677891 Yakutsk (Russian Federation)

    2014-08-20

    We present the energy spectrum of an antiproton cosmic ray (CR) component calculated on the basis of the nonlinear kinetic model of CR production in supernova remnants (SNRs). The model includes the reacceleration of antiprotons already existing in the interstellar medium as well as the creation of antiprotons in nuclear collisions of accelerated protons with gas nuclei and their subsequent acceleration by SNR shocks. It is shown that the production of antiprotons in SNRs produces a considerable effect in their resultant energy spectrum, making it essentially flatter above 10 GeV so that the spectrum at TeV energies increases by a factor of 5. The calculated antiproton spectrum is consistent with the PAMELA data, which correspond to energies below 100 GeV. As a consistency check, we have also calculated within the same model the energy spectra of secondary nuclei and show that the measured boron-to-carbon ratio is consistent with the significant SNR contribution.

  3. Antiprotons Produced in Supernova Remnants

    Science.gov (United States)

    Berezhko, E. G.; Ksenofontov, L. T.

    2014-08-01

    We present the energy spectrum of an antiproton cosmic ray (CR) component calculated on the basis of the nonlinear kinetic model of CR production in supernova remnants (SNRs). The model includes the reacceleration of antiprotons already existing in the interstellar medium as well as the creation of antiprotons in nuclear collisions of accelerated protons with gas nuclei and their subsequent acceleration by SNR shocks. It is shown that the production of antiprotons in SNRs produces a considerable effect in their resultant energy spectrum, making it essentially flatter above 10 GeV so that the spectrum at TeV energies increases by a factor of 5. The calculated antiproton spectrum is consistent with the PAMELA data, which correspond to energies below 100 GeV. As a consistency check, we have also calculated within the same model the energy spectra of secondary nuclei and show that the measured boron-to-carbon ratio is consistent with the significant SNR contribution.

  4. A kidney deformation model for use in non-rigid registration during image-guided surgery

    Science.gov (United States)

    Ong, Rowena E.; Herrell, S. Duke, III; Miga, Michael I.; Galloway, Robert L., Jr.

    2008-03-01

    In order to facilitate the removal of tumors during partial nephrectomies, an image-guided surgery system may be useful. This system would require a registration of the physical kidney to a pre-operative image volume; however, it is unclear whether a rigid registration would be sufficient. One possible source of non-rigid deformation is the clamping of the renal artery during surgery and the subsequent loss of pressure as the kidney is punctured and blood loss occurs. To explore this issue, a model of kidney deformation due to loss of perfusion and pressure was developed based on Biot's consolidation model. The model was tested on two resected porcine kidneys in which the renal artery and vein were clamped. CT image volumes of the kidney were obtained before and after the deformation caused unclamping, and fiducial markers embedded on the kidney surface allowed the deformation to be tracked. The accuracy of the kidney model was accessed by calculating the model error at the fiducial locations and using image similarity measures. Preliminary results indicate that the model may be useful in a non-rigid registration scheme; however, further refinements to the model may be necessary to better simulate the deformation due to loss of perfusion and pressure.

  5. Supernova remnants in the Large Magellanic Cloud

    Science.gov (United States)

    Long, K. S.; Helfand, D. J.

    1979-01-01

    X-ray emission from 10 previously identified supernova remnants (SNR) in the Large Magellanic Cloud has been discovered in a partially completed survey of this nearby galaxy with the imaging proportional counter on the Einstein Observatory. The X-ray luminosities (0.5-3.0 keV) of these remnants range from 3 x 10 to the 35th to 4 x 10 to the 37th ergs/s. N157B and N158A, whose identifications as SNR were previously based solely on their radio spectra, have been detected as strong X-ray emitters. Two other objects from an optically selected list of candidate SNR were found to coincide with X-ray sources and therefore probably are SNR. The value of obtaining such a uniform sample of SNR at a known distance is illustrated by comparing the properties of the remnants and by fitting standard evolutionary models to the results.

  6. Late-Time Evolution of Composite Supernova Remnants: Deep Chandra Observations and Hydrodynamical Modeling of a Crushed Pulsar Wind Nebula in SNR G327.1-1.1

    Science.gov (United States)

    Temim, Tea; Slane, Patrick; Kolb, Christopher; Blondin, John; Hughes, John P.; Bucciantini, Niccolo

    2015-01-01

    In an effort to better understand the evolution of composite supernova remnants (SNRs) and the eventual fate of relativistic particles injected by their pulsars, we present a multifaceted investigation of the interaction between a pulsar wind nebula (PWN) and its host SNR G327.1-1.1. Our 350 ks Chandra X-ray observations of SNR G327.1-1.1 reveal a highly complex morphology; a cometary structure resembling a bow shock, prong-like features extending into large arcs in the SNR interior, and thermal emission from the SNR shell. Spectral analysis of the non-thermal emission offers clues about the origin of the PWN structures, while enhanced abundances in the PWN region provide evidence for mixing of supernova ejecta with PWN material. The overall morphology and spectral properties of the SNR suggest that the PWN has undergone an asymmetric interaction with the SNR reverse shock(RS) that can occur as a result of a density gradient in the ambient medium and or a moving pulsar that displaces the PWN from the center of the remnant. We present hydrodynamical simulations of G327.1-1.1 that show that its morphology and evolution can be described by a approx. 17,000 yr old composite SNR that expanded into a density gradient with an orientation perpendicular to the pulsar's motion. We also show that the RSPWN interaction scenario can reproduce the broadband spectrum of the PWN from radio to gamma-ray wavelengths. The analysis and modeling presented in this work have important implications for our general understanding of the structure and evolution of composite SNRs.

  7. LATE-TIME EVOLUTION OF COMPOSITE SUPERNOVA REMNANTS: DEEP CHANDRA OBSERVATIONS AND HYDRODYNAMICAL MODELING OF A CRUSHED PULSAR WIND NEBULA IN SNR G327.1-1.1

    Energy Technology Data Exchange (ETDEWEB)

    Temim, Tea [Observational Cosmology Lab, Code 665, NASA Goddard Space Flight Center, Greenbelt, MD 20771 (United States); Slane, Patrick [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States); Kolb, Christopher; Blondin, John [North Carolina State University, 421 Riddick Hall, Raleigh, NC 27695 (United States); Hughes, John P. [Rutgers University, 57 US Highway 1, New Brunswick, NJ 08901 (United States); Bucciantini, Niccoló [INAF Osservatorio Astrofisico di Arcetri, Largo Enrico Fermi, 5, 50125, Firenze Italy (Italy)

    2015-07-20

    In an effort to better understand the evolution of composite supernova remnants (SNRs) and the eventual fate of relativistic particles injected by their pulsars, we present a multifaceted investigation of the interaction between a pulsar wind nebula (PWN) and its host SNR G327.1-1.1. Our 350 Chandra X-ray observations of SNR G327.1-1.1 reveal a highly complex morphology: a cometary structure resembling a bow shock, prong-like features extending into large arcs in the SNR interior, and thermal emission from the SNR shell. Spectral analysis of the non-thermal emission offers clues about the origin of the PWN structures, while enhanced abundances in the PWN region provide evidence for a mixing of supernova ejecta with PWN material. The overall morphology and spectral properties of the SNR suggest that the PWN has undergone an asymmetric interaction with the SNR reverse shock (RS), whichcan occur as a result of a density gradient in the ambient medium and/or a moving pulsar that displaces the PWN from the center of the remnant. We present hydrodynamical simulations of G327.1-1.1 that show that its morphology and evolution can be described by a ∼17,000-year-old composite SNR that expanded into a density gradient with an orientation perpendicular to the pulsar’s motion. We also show that the RS/PWN interaction scenario can reproduce the broadband spectrum of the PWN from radio to γ-ray wavelengths. The analysis and modeling presented in this work have important implications for our general understanding of the structure and evolution of composite SNRs.

  8. Low-dose hydralazine prevents fibrosis in a murine model of acute kidney injury-to-chronic kidney disease progression.

    Science.gov (United States)

    Tampe, Björn; Steinle, Ulrike; Tampe, Désirée; Carstens, Julienne L; Korsten, Peter; Zeisberg, Elisabeth M; Müller, Gerhard A; Kalluri, Raghu; Zeisberg, Michael

    2017-01-01

    Acute kidney injury (AKI) and progressive chronic kidney disease (CKD) are intrinsically tied syndromes. In this regard, the acutely injured kidney often does not achieve its full regenerative capacity and AKI directly transitions into progressive CKD associated with tubulointerstitial fibrosis. Underlying mechanisms of such AKI-to-CKD progression are still incompletely understood and specific therapeutic interventions are still elusive. Because epigenetic modifications play a role in maintaining tissue fibrosis, we used a murine model of ischemia-reperfusion injury to determine whether aberrant promoter methylation of RASAL1 contributes causally to the switch between physiological regeneration and tubulointerstitial fibrogenesis, a hallmark of AKI-to-CKD progression. It is known that the antihypertensive drug hydralazine has demethylating activity, and that its optimum demethylating activity occurs at concentrations below blood pressure-lowering doses. Administration of low-dose hydralazine effectively induced expression of hydroxylase TET3, which catalyzed RASAL1 hydroxymethylation and subsequent RASAL1 promoter demethylation. Hydralazine-induced CpG promoter demethylation subsequently attenuated renal fibrosis and preserved excretory renal function independent of its blood pressure-lowering effects. In comparison, RASAL1 demethylation and inhibition of tubulointerstitial fibrosis was not detected upon administration of the angiotensin-converting enzyme inhibitor Ramipril in this model. Thus, RASAL1 promoter methylation and subsequent transcriptional RASAL1 suppression plays a causal role in AKI-to-CKD progression. Copyright © 2016 International Society of Nephrology. Published by Elsevier Inc. All rights reserved.

  9. A Novel Type 2 Diabetes Mouse Model of Combined Diabetic Kidney Disease and Atherosclerosis.

    Science.gov (United States)

    Bornfeldt, Karin E; Kramer, Farah; Batorsky, Anna; Choi, Jinkuk; Hudkins, Kelly L; Tontonoz, Peter; Alpers, Charles E; Kanter, Jenny E

    2017-11-15

    Diabetic kidney disease and atherosclerotic disease are major causes of morbidity and mortality associated with type 2 diabetes (T2D), and diabetic kidney disease is a major cardiovascular risk factor. The BTBR mouse strain with leptin-deficiency (Lepob) has emerged as one of the best models of human diabetic kidney disease. However, no T2D mouse model of combined diabetic kidney disease and atherosclerosis exists. Our goal was to generate such a model. To this end, the LDL receptor was targeted for degradation via IDOL (inducible degrader of the LDL receptor) overexpression, using a liver-targeted adeno-associated virus (AAV-DJ/8) in BTBR wild-type (WT) and BTBR Lepob (OB) mice. Liver-targeted IDOL-AAV-DJ/8 increased plasma LDL cholesterol, as compared with the control eGFP-AAV-DJ/8. IDOL-induced dyslipidemia caused formation of atherosclerotic lesions of an intermediate stage, which contained both macrophages and smooth muscle cells. BTBR OB mice exhibited diabetic kidney disease. IDOL-induced dyslipidemia worsened albuminuria and glomerular macrophage accumulation, but had no effect on mesangial expansion or podocyte numbers. Thus, by inducing hepatic degradation of the LDL receptor, we generated a T2D model of combined kidney disease and atherosclerosis. This model provides a new tool to study mechanisms, interactions, and treatment strategies of kidney disease and atherosclerosis in T2D. Copyright © 2017. Published by Elsevier Inc.

  10. Metabolomic perfusate analysis during kidney machine perfusion: the pig provides an appropriate model for human studies.

    Directory of Open Access Journals (Sweden)

    Jay Nath

    Full Text Available Hypothermic machine perfusion offers great promise in kidney transplantation and experimental studies are needed to establish the optimal conditions for this to occur. Pig kidneys are considered to be a good model for this purpose and share many properties with human organs. However it is not established whether the metabolism of pig kidneys in such hypothermic hypoxic conditions is comparable to human organs.Standard criteria human (n = 12 and porcine (n = 10 kidneys underwent HMP using the LifePort Kidney Transporter 1.0 (Organ Recovery Systems using KPS-1 solution. Perfusate was sampled at 45 minutes and 4 hours of perfusion and metabolomic analysis performed using 1-D 1H-NMR spectroscopy.There was no inter-species difference in the number of metabolites identified. Of the 30 metabolites analysed, 16 (53.3% were present in comparable concentrations in the pig and human kidney perfusates. The rate of change of concentration for 3-Hydroxybutyrate was greater for human kidneys (p<0.001. For the other 29 metabolites (96.7%, there was no difference in the rate of change of concentration between pig and human samples.Whilst there are some differences between pig and human kidneys during HMP they appear to be metabolically similar and the pig seems to be a valid model for human studies.

  11. Kidney transplant

    Science.gov (United States)

    ... always take your medicine as directed. Alternative Names Renal transplant; Transplant - kidney Patient Instructions Kidney removal - discharge Images Kidney anatomy Kidney - blood and urine flow Kidneys Kidney transplant - ...

  12. Additive effects of dietary glycotoxins and androgen excess on the kidney of a female rat model

    Directory of Open Access Journals (Sweden)

    Sotiria Palimeri

    2016-06-01

    Conclusions: The above mentioned data suggest that dietary glycotoxins, in combination with increased androgen exposure, exert a more profound negative impact on the kidney of an androgenized female rat model that mimics the metabolic characteristics of polycystic ovary syndrome.

  13. Risk prediction models for acute kidney injury following major noncardiac surgery: systematic review

    National Research Council Canada - National Science Library

    Wilson, Todd; Quan, Samuel; Cheema, Kim; Zarnke, Kelly; Quinn, Rob; de Koning, Lawrence; Dixon, Elijah; Pannu, Neesh; James, Matthew T

    Acute kidney injury (AKI) is a serious complication of major noncardiac surgery. Risk prediction models for AKI following noncardiac surgery may be useful for identifying high-risk patients to target with prevention strategies...

  14. Supernova Remnant Science with AXIS

    Science.gov (United States)

    Williams, Brian J.; Yamaguchi, Hiroya; AXIS Science Team

    2018-01-01

    We present an overview of the supernova remnant (SNR) science that will be achieved with the Advanced X-ray Imaging Satellite (AXIS). AXIS follows in the footsteps of the spectacularly successful Chandra X-ray Observatory with similar or higher angular resolution and an order of magnitude more collecting area in the 0.3-10 keV band. These capabilities enable major advances in several areas of SNR science. These include, but are not limited to: 1) a more thorough spatial mapping of the ejecta products of both intermediate-mass and iron-group elements in core-collapse and Type Ia SNRs, particularly in remnants with a small diameter. The iron-group elements, specifically Cr, Mn, and Ni, are extremely important for constraining the explosion mechanism for SNe, but are generally weak and difficult to detect with Chandra, XMM-Newton, and Suzaku. 2) Studying the interface of a shock wave with the ambient ISM/CSM to constrain the degree of particle heating and acceleration at shock fronts. Chandra has only provided upper limits on shock precursor emission, and a detailed study of the thermal and nonthermal emission at the shock with greatly increased photon count rates will constrain the properties of the immediate post-shock plasma. 3) A high spatial resolution X-ray observatory will continue to build on the legacy begun by Chandra of studying the proper motion of young remnants. Directly measuring the dynamics of an SNR's evolution is crucial for understanding the explosion mechanism, and with the order of magnitude increase collecting area, we can measure the expansion of individual elemental species in the ejecta. 4) We will greatly increase the statistics of SNRs in nearby galaxies, going much faster and deeper than Chandra's observations. The increased depth of coverage would allow us to do spectroscopy in places where it was previously possible only to do rudimentary statistics. We can compare the local SNR population with the local star-formation rates for galaxies

  15. Mild systemic thermal therapy ameliorates renal dysfunction in a rodent model of chronic kidney disease.

    Science.gov (United States)

    Iwashita, Yoshihiro; Kuwabara, Takashige; Hayata, Manabu; Kakizoe, Yutaka; Izumi, Yuichiro; Iiyama, Junichi; Kitamura, Kenichiro; Mukoyama, Masashi

    2016-06-01

    Thermal therapy has become a nonpharmacological therapy in clinical settings, especially for cardiovascular diseases. However, the practical role of thermal therapy on chronic kidney disease remains elusive. We performed the present study to investigate whether a modified thermal protocol, repeated mild thermal stimulation (MTS), could affect renal damages in chronic kidney disease using a mouse renal ablation model. Mice were subjected to MTS or room temperature (RT) treatment once daily for 4 wk after subtotal nephrectomy (Nx) or sham operation (Sh). We revealed that MTS alleviated renal impairment as indicated by serum creatinine and albuminuria in Nx groups. In addition, the Nx + MTS group showed attenuated tubular histological changes and reduced urinary neutrophil gelatinase-associated lipocalin excretion approximately by half compared with the Nx + RT group. Increased apoptotic signaling, such as TUNEL-positive cell count and cleavage of caspase 3, as well as enhanced oxidative stress were significantly reduced in the Nx + MTS group compared with the Nx + RT group. These changes were accompanied with the restoration of kidney Mn-SOD levels by MTS. Heat shock protein 27, a key molecular chaperone, was phosphorylated by MTS only in Nx kidneys rather than in Sh kidneys. MTS also tended to increase the phosphorylation of p38 MAPK and Akt in Nx kidneys, possibly associated with the activation of heat shock protein 27. Taken together, these results suggest that modified MTS can protect against renal injury in a rodent model of chronic kidney disease. Copyright © 2016 the American Physiological Society.

  16. Improved GFR and renal plasma perfusion following remote ischaemic conditioning in a porcine kidney transplantation model

    DEFF Research Database (Denmark)

    Krogstrup, Nicoline V; Soendergaard, Peter; Secher, Niels G

    2012-01-01

    Delayed graft function (DGF) complicates approximately 25% of kidney allografts donated after brain death (DBD). Remote ischaemic conditioning (rIC) involves brief, repetitive, ischaemia in a distant tissue in connection with ischaemia/reperfusion in the target organ. rIC has been shown to induce...... systemic protection against ischaemic injuries. Using a porcine kidney transplantation model with donor (63 kg) recipient (15 kg) size mismatch, we investigated the effects of recipient rIC on early renal plasma perfusion and GFR. Brain death was induced in donor pigs (n = 8) and kidneys were removed...

  17. High Resolution Ultrasonography for Assessment of Renal Cysts in the PCK Rat Model of Autosomal Recessive Polycystic Kidney Disease.

    OpenAIRE

    Kapoor Sarika; Rodriguez Daniel; Mitchell Katharyn; Wüthrich Rudolf P

    2016-01-01

    BACKGROUND/AIMS: The PCK rat model of polycystic kidney disease is characterized by the progressive development of renal medullary cysts. Here, we evaluated the suitability of high resolution ultrasonography (HRU) to assess the kidney and cyst volume in PCK rats, testing three different ultrasound image analysis methods, and correlating them with kidneys weights and histological examinations. METHODS: After inducing anesthesia, PCK rats (n=18) were subjected to HRU to visualize the kidneys...

  18. Remnants of Compact Group Type Mergers

    Science.gov (United States)

    Weil, M. L.; Hernquist, L.

    1993-12-01

    Recent simulations by several authors who concentrated on extensive exploration of the merger remnant properties of two equal mass disks have been successful in accounting for several aspects of elliptical structure. However, the projected short merging timescales, typically only several half-mass crossing times, of dense, 4-6 member, low velocity dispersion clusters termed compact groups (CG) make them appealing candidates for elliptical progenitors. Self-consistent, high resolution, multi-component models of compact group type mergers have been simulated. Initially, the systems consist of 6 disk galaxies each with with bulge-disk-halo mass and particle number ratios of .333:1:5.8 and 16384:65536:65536, respectively. As in the case of two merging disks, the remnants evince many properties similar to those observed in ellipticals; light profiles, isophotal shapes, and velocity dispersions are comparable to fiducial elliptical values. The surface densities are fit well by a de Vaucouleurs R(1/4) law over a large range of radius, departing from it only in the very inner regions; and the remnant is supported by anisotropic velocity dispersion for the most part, the spin of the initial disks having been transferred to the halo by dynamical friction. In addition, CG remnants improve over previous models by reproducing the observed result that real ellipticals have angular momentum vectors nearly coincident with the minor axis and by suggesting a method of producing ellipticities that coincide more with the observed clustering around Hubble types n ~ 0-2. A small number of parameters are being varied systematically in order to study consequences of changing the internal structure and orientations of the galaxies. Further study will include analysis of metalicity and color gradients which may be imprinted on the original galaxies and examined in the remnant to elucidate the effect of incomplete violent relaxation. In addition, in order to determine the effects of

  19. Radio polarization maps of shell-type supernova remnants - I. Effects of a random magnetic field component and thin-shell models

    Science.gov (United States)

    Bandiera, R.; Petruk, O.

    2016-06-01

    The maps of intensity and polarization of the radio synchrotron emission from shell-type supernova remnants (SNRs) contain a considerable amount of information, although of not easy interpretation. With the aim of deriving constraints on the 3D spatial distribution of the emissivity, as well as on the structure of both ordered and random magnetic fields (MFs), we present here a scheme to model maps of the emission and polarization in SNRs. We first generalize the classical treatment of the synchrotron emission to the case in which the MF is composed of an ordered MF plus an isotropic random component, with arbitrary relative strengths. For a power-law particle energy distribution, we derive analytic formulae that formally resemble those for the classical case. We also treat the shock compression of a fully random upstream field and we predict that the polarization fraction in this case should be higher than typically measured in SNRs. We implement the above treatment into a code, which simulates the observed polarized emission of an emitting shell, taking into account also the effect of the internal Faraday rotation. Finally, we show simulated maps for different orientations with respect to the observer, levels of the turbulent MF component, Faraday rotation levels, distributions of the emissivity (either barrel-shaped or limited to polar caps) and geometries for the ordered MF component (either tangential to the shell or radial). Their analysis allows us to outline properties useful for the interpretation of radio intensity and polarization maps.

  20. Remnants of Lost Geology

    Science.gov (United States)

    2003-01-01

    [figure removed for brevity, see original site] In eastern Arabia Terra, remnants of a once vast layered terrain are evident as isolated buttes, mesas, and deeply-filled craters. The origin of the presumed sediments that created the layers is unknown, but those same sediments, now eroded, may be the source of the thick mantle of dust that covers much of Arabia Terra today.Note: this THEMIS visual image has not been radiometrically nor geometrically calibrated for this preliminary release. An empirical correction has been performed to remove instrumental effects. A linear shift has been applied in the cross-track and down-track direction to approximate spacecraft and planetary motion. Fully calibrated and geometrically projected images will be released through the Planetary Data System in accordance with Project policies at a later time.NASA's Jet Propulsion Laboratory manages the 2001 Mars Odyssey mission for NASA's Office of Space Science, Washington, D.C. The Thermal Emission Imaging System (THEMIS) was developed by Arizona State University, Tempe, in collaboration with Raytheon Santa Barbara Remote Sensing. The THEMIS investigation is led by Dr. Philip Christensen at Arizona State University. Lockheed Martin Astronautics, Denver, is the prime contractor for the Odyssey project, and developed and built the orbiter. Mission operations are conducted jointly from Lockheed Martin and from JPL, a division of the California Institute of Technology in Pasadena.Image information: VIS instrument. Latitude 20.5, Longitude 50 East (310 West). 19 meter/pixel resolution.

  1. CSI in Supernova Remnants

    Science.gov (United States)

    Chu, You-Hua

    2017-02-01

    Supernovae (SNe) explode in environments that have been significantly modified by the SN progenitors. For core-collapse SNe, the massive progenitors ionize the ambient interstellar medium (ISM) via UV radiation and sweep the ambient ISM via fast stellar winds during the main sequence phase, replenish the surroundings with stellar material via slow winds during the luminous blue variable (LBV) or red supergiant (RSG) phase, and sweep up the circumstellar medium (CSM) via fast winds during the Wolf-Rayet (WR) phase. If a massive progenitor was in a close binary system, the binary interaction could have caused mass ejection in certain preferred directions, such as the orbital plane, and even bipolar outflow/jet. As a massive star finally explodes, the SN ejecta interacts first with the CSM that was ejected and shaped by the star itself. As the newly formed supernova remnant (SNR) expands further, it encounters interstellar structures that were shaped by the progenitor from earlier times. Therefore, the structure and evolution of a SNR is largely dependent on the initial mass and close binarity of the SN progenitor. The Large Magellanic Cloud (LMC) has an excellent sample of over 50 confirmed SNRs that are well resolved by Hubble Space Telescope, Chandra X-ray Observatory, and Spitzer Space Telescope. These multi-wavelength observations allow us to conduct stellar forensics in SNRs and understand the wide variety of morphologies and physical properties of SNRs observed.

  2. Kidney Injury Molecule-1 Is Specifically Expressed in Cystically-Transformed Proximal Tubules of the PKD/Mhm (cy/+ Rat Model of Polycystic Kidney Disease

    Directory of Open Access Journals (Sweden)

    Stefan Gauer

    2016-05-01

    Full Text Available Expression of kidney injury molecule-1 (Kim-1 is rapidly upregulated following tubular injury, constituting a biomarker for acute kidney damage. We examined the renal localization of Kim-1 expression in PKD/Mhm (polycystic kidney disease, Mannheim (cy/+ rats (cy: mutated allel, +: wild type allel, an established model for autosomal dominant polycystic kidney disease, with chronic, mainly proximal tubulointerstitial alterations. For immunohistochemistry or Western blot analysis, kidneys of male adult heterozygously-affected (cy/+ and unaffected (+/+ littermates were perfusion-fixed or directly removed. Kim-1 expression was determined using peroxidase- or fluorescence-linked immunohistochemistry (alone or in combination with markers for tubule segments or differentiation. Compared to (+/+, only in (cy/+ kidneys, a chronic expression of Kim-1 could be detected by Western blot analysis, which was histologically confined to an apical cellular localization in areas of cystically-transformed proximal tubules with varying size and morphology, but not in distal tubular segments. Kim-1 was expressed by cystic epithelia exhibiting varying extents of dedifferentiation, as shown by double labeling with aquaporin-1, vimentin or osteopontin, yielding partial cellular coexpression. In this model, in contrast to other known molecules indicating renal injury and/or repair mechanisms, the chronic renal expression of Kim-1 is strictly confined to proximal cysts. Its exact role in interfering with tubulo-interstitial alterations in polycystic kidney disease warrants future investigations.

  3. Effect of NSAIDs and diuretics on nephrogenesis in an ex vivo embryogenic kidney model.

    Science.gov (United States)

    Bueters, Ruud Rg; Klaasen, Annelies; van den Heuvel, Lambertus P; Schreuder, Michiel F

    2013-12-01

    The kidney is one of the key organs in clearing foreign compounds. The effects of drugs on the developing kidney are relatively unknown. We studied the direct effect of furosemide, hydrochlorothiazide, ibuprofen, and indomethacin on kidney development in an ex vivo embryonic kidney model. At embryonic day 13, metanephroi were dissected from mice and cultured in control media or media supplemented with various clinically relevant concentrations of drugs. The ureteric tree was visualized by whole-mount staining and branching was evaluated by counting. Additionally, gene expression levels of Wt1, Sox9, Bmp7, Fgf8, and Gdnf were investigated. No distinct differences were noted on either ureteric tip development or gene expression analysis for each drug after 24 hr of exposure. Even though short-term exposure to clinically relevant concentrations seems not to disturb renal development, future research is needed to study prolonged or repeated exposures. © 2014 Wiley Periodicals, Inc.

  4. A parametric model of radioisotopic tracer flow through the kidney; Parametryczny model przeplywu wskaznika izotopowego przez nerke

    Energy Technology Data Exchange (ETDEWEB)

    Nahorski, Z. [Pion Systemow Wspomagania Decyzji, Instytut Badan Systemowych, Polska Akademia Nauk, Warsaw (Poland)

    1996-12-31

    To assess the state of a kidney from radiological examination a dynamic model of flow of an isotopic tracer through the kidney, of a convolution type, is commonly used. It is a nonparametric model where the output is related to the input by an integral relation. In this paper a new parametric model of tracer flow through the kidney is presented. It takes to much bigger extent into account the physiology of the tracer flow in kidney than previously proposed compartmental models. It consists of the submodels of flow through nephrons which are in the form of ordinary differential equations with pure delays between input and the output flows. The delay is caused by the time of passage of the isotope through nephrons and depends on the nephron length. It is assumed that the distribution of nephrons of different length is exponential. The renal pelvis is described as the one-compartment model. The solutions of the equations are given for the assumed two-exponential decay of the isotope tracer in the blood following the bolus injection of the tracer. The formulae obtained are then used to simulate the influence of changes in the model parameters, representing the flow condition through the kidney, on the shape of the waveforms depicting time evolution of the amount of the isotope being in the kidney 18 refs, 11 figs

  5. Personalized 3D printed model of kidney and tumor anatomy: a useful tool for patient education.

    Science.gov (United States)

    Bernhard, Jean-Christophe; Isotani, Shuji; Matsugasumi, Toru; Duddalwar, Vinay; Hung, Andrew J; Suer, Evren; Baco, Eduard; Satkunasivam, Raj; Djaladat, Hooman; Metcalfe, Charles; Hu, Brian; Wong, Kelvin; Park, Daniel; Nguyen, Mike; Hwang, Darryl; Bazargani, Soroush T; de Castro Abreu, Andre Luis; Aron, Monish; Ukimura, Osamu; Gill, Inderbir S

    2016-03-01

    To assess the impact of 3D printed models of renal tumor on patient's understanding of their conditions. Patient understanding of their medical condition and treatment satisfaction has gained increasing attention in medicine. Novel technologies such as additive manufacturing [also termed three-dimensional (3D) printing] may play a role in patient education. A prospective pilot study was conducted, and seven patients with a primary diagnosis of kidney tumor who were being considered for partial nephrectomy were included after informed consent. All patients underwent four-phase multi-detector computerized tomography (MDCT) scanning from which renal volume data were extracted to create life-size patient-specific 3D printed models. Patient knowledge and understanding were evaluated before and after 3D model presentation. Patients' satisfaction with their specific 3D printed model was also assessed through a visual scale. After viewing their personal 3D kidney model, patients demonstrated an improvement in understanding of basic kidney physiology by 16.7 % (p = 0.018), kidney anatomy by 50 % (p = 0.026), tumor characteristics by 39.3 % (p = 0.068) and the planned surgical procedure by 44.6 % (p = 0.026). Presented herein is the initial clinical experience with 3D printing to facilitate patient's pre-surgical understanding of their kidney tumor and surgery.

  6. Towards a symptom cluster model in chronic kidney disease: A structural equation approach.

    Science.gov (United States)

    Almutary, Hayfa; Douglas, Clint; Bonner, Ann

    2017-10-01

    The aim of this study was to test a symptom cluster model in chronic kidney disease patients based on the Theory of Unpleasant Symptoms, accounting for the relationships between influencing factors, symptom experience and consequences for quality of life. The evaluation of symptom clusters is a new field of scientific inquiry directed towards more focused symptom management. Yet, little is known about relationships between symptom clusters, predictors and the synergistic effect of multiple symptoms on outcomes. Cross-sectional. Data were collected from 436 patients with advanced stages of chronic kidney disease during July 2013-February 2014 using validated measures of symptom burden and quality of life. Analysis involved structural equation modelling. The final model demonstrated good fit with the data and provided strong evidence for the predicted relationships. Psychological distress, stage of chronic kidney disease and age explained most of the variance in symptom experience. Symptom clusters had a strong negative effect on quality of life, with fatigue, sexual symptoms and restless legs being the strongest predictors. Overall, the model explained more than half of the deterioration in quality of life. However, a reciprocal path between quality of life and symptom experience was not found. Interventions targeting symptom clusters could greatly improve quality of life in patients with chronic kidney disease. The symptom cluster model presented has important clinical and heuristic implications, serving as a framework to encourage and guide new lines of intervention research to reduce symptom burden in chronic kidney disease. © 2017 John Wiley & Sons Ltd.

  7. The First Fermi LAT Supernova Remnant Catalog

    Science.gov (United States)

    Acero, F.; Ackermann, M.; Ajello, M.; Baldini, L.; Ballet, J.; Barbiellini, G.; Bastieri, D.; Bellazzini, R.; Bissaldi, E.; Blandford, R. D.; Bloom, E. D.; Bonino, R.; Bottacini, E.; Brandt, T. J.; Bregeon, J.; Bruel, P.; Buehler, R.; Buson, S.; Caliandro, G. A.; Cameron, R. A.; Caputo, R.; Caragiulo, M.; Caraveo, P. A.; Casandjian, J. M.; Cavazzuti, E.; Cecchi, C.; Chekhtman, A.; Chiang, J.; Chiaro, G.; Ciprini, S.; Claus, R.; Cohen, J. M.; Cohen-Tanugi, J.; Cominsky, L. R.; Condon, B.; Conrad, J.; Cutini, S.; D'Ammando, F.; de Angelis, A.; de Palma, F.; Desiante, R.; Digel, S. W.; Di Venere, L.; Drell, P. S.; Drlica-Wagner, A.; Favuzzi, C.; Ferrara, E. C.; Franckowiak, A.; Fukazawa, Y.; Funk, S.; Fusco, P.; Gargano, F.; Gasparrini, D.; Giglietto, N.; Giommi, P.; Giordano, F.; Giroletti, M.; Glanzman, T.; Godfrey, G.; Gomez-Vargas, G. A.; Grenier, I. A.; Grondin, M.-H.; Guillemot, L.; Guiriec, S.; Gustafsson, M.; Hadasch, D.; Harding, A. K.; Hayashida, M.; Hays, E.; Hewitt, J. W.; Hill, A. B.; Horan, D.; Hou, X.; Iafrate, G.; Jogler, T.; Jóhannesson, G.; Johnson, A. S.; Kamae, T.; Katagiri, H.; Kataoka, J.; Katsuta, J.; Kerr, M.; Knödlseder, J.; Kocevski, D.; Kuss, M.; Laffon, H.; Lande, J.; Larsson, S.; Latronico, L.; Lemoine-Goumard, M.; Li, J.; Li, L.; Longo, F.; Loparco, F.; Lovellette, M. N.; Lubrano, P.; Magill, J.; Maldera, S.; Marelli, M.; Mayer, M.; Mazziotta, M. N.; Michelson, P. F.; Mitthumsiri, W.; Mizuno, T.; Moiseev, A. A.; Monzani, M. E.; Moretti, E.; Morselli, A.; Moskalenko, I. V.; Murgia, S.; Nemmen, R.; Nuss, E.; Ohsugi, T.; Omodei, N.; Orienti, M.; Orlando, E.; Ormes, J. F.; Paneque, D.; Perkins, J. S.; Pesce-Rollins, M.; Petrosian, V.; Piron, F.; Pivato, G.; Porter, T. A.; Rainò, S.; Rando, R.; Razzano, M.; Razzaque, S.; Reimer, A.; Reimer, O.; Renaud, M.; Reposeur, T.; Rousseau, R.; Saz Parkinson, P. M.; Schmid, J.; Schulz, A.; Sgrò, C.; Siskind, E. J.; Spada, F.; Spandre, G.; Spinelli, P.; Strong, A. W.; Suson, D. J.; Tajima, H.; Takahashi, H.; Tanaka, T.; Thayer, J. B.; Thompson, D. J.; Tibaldo, L.; Tibolla, O.; Torres, D. F.; Tosti, G.; Troja, E.; Uchiyama, Y.; Vianello, G.; Wells, B.; Wood, K. S.; Wood, M.; Yassine, M.; den Hartog, P. R.; Zimmer, S.

    2016-05-01

    To uniformly determine the properties of supernova remnants (SNRs) at high energies, we have developed the first systematic survey at energies from 1 to 100 GeV using data from the Fermi Large Area Telescope (LAT). Based on the spatial overlap of sources detected at GeV energies with SNRs known from radio surveys, we classify 30 sources as likely GeV SNRs. We also report 14 marginal associations and 245 flux upper limits. A mock catalog in which the positions of known remnants are scrambled in Galactic longitude allows us to determine an upper limit of 22% on the number of GeV candidates falsely identified as SNRs. We have also developed a method to estimate spectral and spatial systematic errors arising from the diffuse interstellar emission model, a key component of all Galactic Fermi LAT analyses. By studying remnants uniformly in aggregate, we measure the GeV properties common to these objects and provide a crucial context for the detailed modeling of individual SNRs. Combining our GeV results with multiwavelength (MW) data, including radio, X-ray, and TeV, we demonstrate the need for improvements to previously sufficient, simple models describing the GeV and radio emission from these objects. We model the GeV and MW emission from SNRs in aggregate to constrain their maximal contribution to observed Galactic cosmic rays.

  8. Effect calcusol to reduce the calcium crystal retention in kidney epithelial cells model of nephrolothiasis

    Directory of Open Access Journals (Sweden)

    Ahmad Soni

    2014-12-01

    Full Text Available Kidney stones is a disease that characterized by a disturbance in the bladder. The main constituent of kidney stones namely Calcium Oxalate Monohydrate (COM crystals. The presence of a COM crystal adhesion to renal tubular cells, will initiate the internalization which will further lead to the formation of crystals retention in the kidney. In Indonesia, there are many herbal products are considered able to cope the complaints due to the kidney stone disease. One of the herbal product is Calcusol „¢, which is the main constituent of those herbal product was the leaf extract of tempuyung. This study observed the effectiveness of Calcusol „¢ in reducing crystals retention that was formed in kidney epithelial cells model of nephrolithiasis. The result showed that Calcusol „¢ is able to reduce the average number of calcium crystals retention in the renal epithelial cells. It indicate that Calcusol „¢ has the ability to reduce crystals retention that already formed in renal epithelial cells. Furthermore, the results of this study are expected to be one of the considerations for further research on the potential of overcoming Calcusol „¢ in kidney stone disease

  9. Kidney transplantation process in Brazil represented in business process modeling notation.

    Science.gov (United States)

    Peres Penteado, A; Molina Cohrs, F; Diniz Hummel, A; Erbs, J; Maciel, R F; Feijó Ortolani, C L; de Aguiar Roza, B; Torres Pisa, I

    2015-05-01

    Kidney transplantation is considered to be the best treatment for people with chronic kidney failure, because it improves the patients' quality of life and increases their length of survival compared with patients undergoing dialysis. The kidney transplantation process in Brazil is defined through laws, decrees, ordinances, and resolutions, but there is no visual representation of this process. The aim of this study was to analyze official documents to construct a representation of the kidney transplantation process in Brazil with the use of business process modeling notation (BPMN). The methodology for this study was based on an exploratory observational study, document analysis, and construction of process diagrams with the use of BPMN. Two rounds of validations by specialists were conducted. The result includes the kidney transplantation process in Brazil representation with the use of BPMN. We analyzed 2 digital documents that resulted in 2 processes with 45 total of activities and events, 6 organizations involved, and 6 different stages of the process. The constructed representation makes it easier to understand the rules for the business of kidney transplantation and can be used by the health care professionals involved in the various activities within this process. Construction of a representation with language appropriate for the Brazilian lay public is underway. Copyright © 2015 Elsevier Inc. All rights reserved.

  10. A Dirichlet process mixture model for survival outcome data: assessing nationwide kidney transplant centers.

    Science.gov (United States)

    Zhao, Lili; Shi, Jingchunzi; Shearon, Tempie H; Li, Yi

    2015-04-15

    Mortality rates are probably the most important indicator for the performance of kidney transplant centers. Motivated by the national evaluation of mortality rates at kidney transplant centers in the USA, we seek to categorize the transplant centers based on the mortality outcome. We describe a Dirichlet process model and a Dirichlet process mixture model with a half-cauchy prior for the estimation of the risk-adjusted effects of the transplant centers, with strategies for improving the model performance, interpretability, and classification ability. We derive statistical measures and create graphical tools to rate transplant centers and identify outlying groups of centers with exceptionally good or poor performance. The proposed method was evaluated through simulation and then applied to assess kidney transplant centers from a national organ failure registry. Copyright © 2015 John Wiley & Sons, Ltd.

  11. Hydrodynamical and radio evolution of young supernova remnant G1.9+0.3 based on the model of diffusive shock acceleration

    Science.gov (United States)

    Pavlović, M. Z.

    2017-06-01

    The radio evolution of, so far the youngest known, Galactic supernova remnant (SNR) G1.9+0.3 is investigated by using three-dimensional (3D) hydrodynamic modelling and non-linear kinetic theory of cosmic ray (CR) acceleration in SNRs. We include consistent numerical treatment of magnetic field amplification (MFA) due to resonant streaming instability. Under the assumption that SNR G1.9+0.3 is the result of a Type Ia supernova explosion located near the Galactic Centre, using widely accepted values for explosion energy 1051 erg and ejecta mass 1.4 M⊙, the non-thermal continuum radio emission is calculated. The main purpose of this paper is to explain radio flux brightening measured over recent decades and also predict its future temporal evolution. We estimate that the SNR is now ˜120 yr old, expanding in an ambient density of 0.02 cm-3, and explain its steep radio spectral index only by means of efficient non-linear diffusive shock acceleration (NLDSA). We also make comparison between simulations and observations of this young SNR, in order to test the models and assumptions suggested. Our model prediction of a radio flux density increase of ˜1.8 per cent yr-1 during the past two decades agrees well with the measured values. We synthesize the synchrotron spectrum from radio to X-ray and it fits well the Very Large Array, Molonglo Observatory Synthesis Telescope, Effelsberg, Chandra and NuSTAR measurements. We also propose a simplified evolutionary model of the SNR in gamma rays and suggest it may be a promising target for gamma-ray observations at TeV energies with the future generation of instruments like Cherenkov Telescope Array. SNR G1.9+0.3 is the only known Galactic SNR with the increasing flux density and we present here the prediction that the flux density will start to decrease approximately 500 yr from now. We conclude that this is a general property of SNRs in the free expansion phase.

  12. Animal models of pediatric chronic kidney disease. Is adenine intake an appropriate model?

    Directory of Open Access Journals (Sweden)

    Débora Claramunt

    2015-11-01

    Full Text Available Pediatric chronic kidney disease (CKD has peculiar features. In particular, growth impairment is a major clinical manifestation of CKD that debuts in pediatric age because it presents in a large proportion of infants and children with CKD and has a profound impact on the self-esteem and social integration of the stunted patients. Several factors associated with CKD may lead to growth retardation by interfering with the normal physiology of growth plate, the organ where longitudinal growth rate takes place. The study of growth plate is hardly possible in humans and justifies the use of animal models. Young rats made uremic by 5/6 nephrectomy have been widely used as a model to investigate growth retardation in CKD. This article examines the characteristics of this model and analyzes the utilization of CKD induced by high adenine diet as an alternative research protocol.

  13. Effects of the pneumoperitoneum in rats submitted to a unilateral nephrectomy: morphologic and functional study on the remnant kidney Efeitos do pneumoperitônio em ratos submetidos a nefrectomia unilateral: estudos morfológicos e funcionais no rim remanescente

    Directory of Open Access Journals (Sweden)

    Luiz Sergio Santos

    2005-06-01

    Full Text Available PURPOSE: The aim of this experimental study is to analyze the morphologic and functional effects of the pneumoperitoneum on the remnant kidney in rats submitted to a unilateral nephrectomy. METHODS: Forty-eight male adults Wistar rats , with an average weight between 240 to 350 g, were distributed in three groups. The rats in Group 1 were subdivided into two other subgroups: Control Group 1A and 1B. Groups 2 and 3 and respective subgroups included 12 rats each. All animals were anesthetized and submitted to a puncture. Animals in Groups 2 and 3 were submitted to abdominal insufflation with CO2, during 2 and 4 hours respectively, with a constant IAP of 15 mmHg. Rats of the Control Group 1A and 1B were maintained punctured during 2 and 4 hours respectively, however, without insufflation. In the end of this period, a left nephrectomy was performed in all animals. After 4 weeks, a new pneumoperitoneum with the same duration was installed, according to the groups. After 8 weeks, the animals were submitted to euthanasia to remove the remnant kidney. Samples of blood were collected during the whole experiment to evaluated the renal function by dosing serum creatinine. The remnant kidney was analyzed microscopically to evaluate its level of glomerular hypertrophy, the number of mesangial cells, and to observe the presence of glomerular sclerosis. All groups were kept under observation and the results were submitted to statistical analysis by a longitudinal and transversal comparative study. RESULTS: At the evaluation of residual renal function no significant clinical alteration was seen in rats submitted to pneumoperitoneum during 2 and 4 hours after a period of 8 weeks. The morphologic analysis of the remnant kidney showed no histological renal injury in the groups. CONCLUSION: The function and renal morphology of rats submitted to a unilateral nephrectomy were not significantly influenced by prolonged and successive pneumoperitoneum, according to this

  14. Remnant for all black objects due to gravity's rainbow

    Directory of Open Access Journals (Sweden)

    Ahmed Farag Ali

    2015-05-01

    Full Text Available We argue that a remnant is formed for all black objects in gravity's rainbow. This will be based on the observation that a remnant depends critically on the structure of the rainbow functions, and this dependence is a model independent phenomena. We thus propose general relations for the modified temperature and entropy of all black objects in gravity's rainbow. We explicitly check this to be the case for Kerr, Kerr–Newman-dS, charged-AdS, and higher dimensional Kerr–AdS black holes. We also try to argue that a remnant should form for black saturn in gravity's rainbow. This work extends our previous results on remnants of Schwarzschild black holes [1] and black rings [2].

  15. Loss of Glis2/NPHP7 causes kidney epithelial cell senescence and suppresses cyst growth in the Kif3a mouse model of cystic kidney disease.

    Science.gov (United States)

    Lu, Dongmei; Rauhauser, Alysha; Li, Binghua; Ren, Chongyu; McEnery, Kayla; Zhu, Jili; Chaki, Moumita; Vadnagara, Komal; Elhadi, Sarah; Jetten, Anton M; Igarashi, Peter; Attanasio, Massimo

    2016-06-01

    Enlargement of kidney tubules is a common feature of multiple cystic kidney diseases in humans and mice. However, while some of these pathologies are characterized by cyst expansion and organ enlargement, in others, progressive interstitial fibrosis and kidney atrophy prevail. The Kif3a knockout mouse is an established non-orthologous mouse model of cystic kidney disease. Conditional inactivation of Kif3a in kidney tubular cells results in loss of primary cilia and rapid cyst growth. Conversely, loss of function of the gene GLIS2/NPHP7 causes progressive kidney atrophy, interstitial inflammatory infiltration, and fibrosis. Kif3a null tubular cells have unrestrained proliferation and reduced stabilization of p53 resulting in a loss of cell cycle arrest in the presence of DNA damage. In contrast, loss of Glis2 is associated with activation of checkpoint kinase 1, stabilization of p53, and induction of cell senescence. Interestingly, the cystic phenotype of Kif3a knockout mice is partially rescued by genetic ablation of Glis2 and pharmacological stabilization of p53. Thus, Kif3a is required for cell cycle regulation and the DNA damage response, whereas cell senescence is significantly enhanced in Glis2 null cells. Hence, cell senescence is a central feature in nephronophthisis type 7 and Kif3a is unexpectedly required for efficient DNA damage response and cell cycle arrest. Copyright © 2016 International Society of Nephrology. Published by Elsevier Inc. All rights reserved.

  16. Red yeast rice repairs kidney damage and reduces inflammatory transcription factors in rat models of hyperlipidemia.

    Science.gov (United States)

    Ding, Mei; Si, Daoyuan; Zhang, Wenqi; Feng, Zhaohui; He, Min; Yang, Ping

    2014-12-01

    Xuezhikang (XZK), an extract of red yeast rice, has been widely used for the management of hyperlipidemia and coronary heart disease (CHD); however, the effects of XZK treatment on kidney injury have not yet been fully identified. The aim of the current study was to evaluate the effects of XZK on the kidneys and investigate the related mechanisms in a rat model of hyperlipidemia. Thus, the effect on inflammatory transcription factors and kidney damage was investigated with in vitro and in vivo experiments on hyperlipidemic rats following XZK treatment. The results revealed that the plasma levels of total cholesterol (TC), triglycerides (TG) and low-density lipoprotein-cholesterol (LDL-C) were significantly decreased, while the levels of high-density lipoprotein-cholesterol (HDL-C) were significantly upregulated in the XZK treatment group, as compared with those in the hyperlipidemia group (P<0.05). In addition, the results demonstrated that XZK was able to repair the kidney damage caused by hyperlipidemia. Furthermore, the expression levels of the inflammatory transcription factors, tumor necrosis factor-α and interleukin-6, were shown to be reduced in the XZK group when compared with the hyperlipidemia group. In summary, XZK reduces kidney injury, downregulates the levels of TG, TC and LDL-C, as well as the expression levels of inflammatory transcription factors, and upregulates HDL-C. These results further the understanding of the molecular pathogenic mechanisms underlying hyperlipidemia and aid the development of XZK as an effective therapeutic agent for hyperlipidemia.

  17. Renal primordia activate kidney regenerative events in a rat model of progressive renal disease.

    Directory of Open Access Journals (Sweden)

    Barbara Imberti

    Full Text Available New intervention tools for severely damaged kidneys are in great demand to provide patients with a valid alternative to whole organ replacement. For repairing or replacing injured tissues, emerging approaches focus on using stem and progenitor cells. Embryonic kidneys represent an interesting option because, when transplanted to sites such as the renal capsule of healthy animals, they originate new renal structures. Here, we studied whether metanephroi possess developmental capacity when transplanted under the kidney capsule of MWF male rats, a model of spontaneous nephropathy. We found that six weeks post-transplantation, renal primordia developed glomeruli and tubuli able to filter blood and to produce urine in cyst-like structures. Newly developed metanephroi were able to initiate a regenerative-like process in host renal tissues adjacent to the graft in MWF male rats as indicated by an increase in cell proliferation and vascular density, accompanied by mRNA and protein upregulation of VEGF, FGF2, HGF, IGF-1 and Pax-2. The expression of SMP30 and NCAM was induced in tubular cells. Oxidative stress and apoptosis markedly decreased. Our study shows that embryonic kidneys generate functional nephrons when transplanted into animals with severe renal disease and at the same time activate events at least partly mimicking those observed in kidney tissues during renal regeneration.

  18. Modeling of Kidney Hemodynamics: Probability-Based Topology of an Arterial Network

    DEFF Research Database (Denmark)

    Postnov, Dmitry D; Marsh, Donald J; Postnov, Dmitry E

    2016-01-01

    . We provide experimental data and a new modeling approach to clarify this problem. To resolve details of microvascular structure, we collected 3D data from more than 150 afferent arterioles in an optically cleared rat kidney. Using these results together with published micro-computed tomography (μ...

  19. Intravoxel incoherent motion modeling in the kidneys: Comparison of mono-, bi-, and triexponential fit

    NARCIS (Netherlands)

    van Baalen, Sophie Jacobine; Leemans, Alexander; Dik, Pieter; Lilien, Marc R.; ten Haken, Bernard; Froeling, Martijn

    Purpose To evaluate if a three-component model correctly describes the diffusion signal in the kidney and whether it can provide complementary anatomical or physiological information about the underlying tissue. Materials and Methods Ten healthy volunteers were examined at 3T, with T2-weighted

  20. High Resolution Ultrasonography for Assessment of Renal Cysts in the PCK Rat Model of Autosomal Recessive Polycystic Kidney Disease

    Directory of Open Access Journals (Sweden)

    Sarika Kapoor

    2016-03-01

    Full Text Available Background/Aims: The PCK rat model of polycystic kidney disease is characterized by the progressive development of renal medullary cysts. Here, we evaluated the suitability of high resolution ultrasonography (HRU to assess the kidney and cyst volume in PCK rats, testing three different ultrasound image analysis methods, and correlating them with kidneys weights and histological examinations. Methods: After inducing anesthesia, PCK rats (n=18 were subjected to HRU to visualize the kidneys, to perform numeric and volumetric measurements of the kidney and any cysts observed, and to generate 3-dimensional images of the cysts within the kidney parenchyma. Results: HRU provided superior information in comparison to microscopic analysis of stained kidney sections. HRU-based kidney volumes correlated strongly with kidney weights (R2=0.809; PConclusion: HRU represents a useful diagnostic tool for kidney and cyst volume measurements in PCK rats. Sequential HRU examinations may be useful to study the effect of drugs on cyst growth without the need to euthanize experimental animals.

  1. The Interstellar Medium in Our Galaxy: a New Interpretation of the Distribution of Hot/cool Gas Boundaries in the Disk, and Models of Supernova Remnants in the Halo.

    Science.gov (United States)

    Shelton, Robin Lynn

    1996-01-01

    O VI in the Interstellar Medium. The Copernicus O^{+5} column densities trace the 10^{5.5} K gas in the interstellar medium. We statistically re-analyze the dataset, including the possibility that local hot gas may contribute a significant O^{+5 } column density to most lines of sight. Our reanalysis includes slight improvements in the statistics and was found to be reliable when tested on simulated data sets. Our conclusions differ considerably from those of the original analysis and strongly influence the understanding of the interstellar medium, in particular the volume occupation of the hot and warm components, and mechanisms responsible for them. The Local Bubble column density compares favorably with the estimated quantity of O^{+5 } within the remnant of an ancient local explosion. Similarly, our mean O^{+5} column density per external feature agrees with models of hot interstellar bubbles from either stellar winds or ancient supernova explosions in a warm diffuse interstellar environment, suggesting that the hot gas in interstellar space may exist primarily within discrete regions of modest volume occupation rather than in a continuous and pervasive phase. Supernova Remnants in the Halo. High latitude observations of C^{+3} N^{+4}, and O ^{+5}, and the shadowing of high latitude x-ray emission by intervening hydrogen clouds indicate the presence of hot (~10 ^4 to 10^6K) gas in the halo of our galaxy. This project explores the contributions made by isolated supernova remnants. Their evolving structures were simulated with a hydrodynamic computer code. The results are intriguing. (1) At late times the remnants collapse faster than the high -stage ions can recombine. (2) The high-stage ions in the ensemble of remnants cover about ~50% of the sky. (3) The ensemble provides average column densities of >3.1 times 10 13 O^ {+5} atoms cm^{-2 }, >2.5 times 1012 N ^{+4} atoms cm^ {-2} and gg9.8 times 1012 C^{+3} atoms cm ^{-2}. The average O ^{+5} column density is

  2. Developing better mouse models to study cisplatin-induced kidney injury.

    Science.gov (United States)

    Sharp, Cierra N; Siskind, Leah J

    2017-10-01

    Cisplatin is a potent chemotherapeutic used for the treatment of many types of cancer. However, its dose-limiting side effect is nephrotoxicity leading to acute kidney injury (AKI). Patients who develop AKI have an increased risk of mortality and are more likely to develop chronic kidney disease (CKD). Unfortunately, there are no therapeutic interventions for the treatment of AKI. It has been suggested that the lack of therapies is due in part to the fact that the established mouse model used to study cisplatin-induced AKI does not recapitulate the cisplatin dosing regimen patients receive. In recent years, work has been done to develop more clinically relevant models of cisplatin-induced kidney injury, with much work focusing on incorporation of multiple low doses of cisplatin administered over a period of weeks. These models can be used to recapitulate the development of CKD after AKI and, by doing so, increase the likelihood of identifying novel therapeutic targets for the treatment of cisplatin-induced kidney injury. Copyright © 2017 the American Physiological Society.

  3. Combination of ACE inhibitor with nicorandil provides further protection in chronic kidney disease.

    Science.gov (United States)

    Shiraishi, Takeshi; Tamura, Yoshifuru; Taniguchi, Kei; Higaki, Masato; Ueda, Shuko; Shima, Tomoko; Nagura, Michito; Nakagawa, Takahiko; Johnson, Richard J; Uchida, Shunya

    2014-12-15

    An inhibition in the renin-angiotensin system (RAS) is one of the most widely used therapies to treat chronic kidney disease. However, its effect is occasionally not sufficient and additional treatments may be required. Recently, we reported that nicorandil exhibited renoprotective effects in a mouse model of diabetic nephropathy. Here we examined if nicorandil can provide an additive protection on enalapril in chronic kidney disease. Single treatment with either enalapril or nicorandil significantly ameliorated glomerular and tubulointerstitial injury in the rat remnant kidney while the combination of these two compounds provided additive effects. In addition, an increase in oxidative stress in remnant kidney was also blocked by either enalapril or nicorandil while the combination of the drugs was more potent. A mechanism was likely due for nicorandil to preventing manganase superoxide dismutase (MnSOD) and sirtuin (Sirt)3 from being reduced in injured kidneys. A study with cultured podocytes indicated that the antioxidative effect could be mediated through sulfonylurea receptor (SUR) in the mitochondrial KATP channel since blocking SUR with glibenclamide reduced MnSOD and Sirt3 expression in podocytes. In conclusion, nicorandil may synergize with enalapril to provide superior protection in chronic kidney disease. Copyright © 2014 the American Physiological Society.

  4. The Kidney Disease Screening and Awareness Program (KDSAP): a novel translatable model for increasing interest in nephrology careers.

    Science.gov (United States)

    Hsiao, Li-Li; Wu, Jingshing; Yeh, Albert C; Shieh, Eric C; Cui, Cheryl; Li, Ang; Polding, Laura C; Ahmed, Rayhnuma; Lim, Kenneth; Lu, Tzong-Shi; Rhee, Connie M; Bonventre, Joseph V

    2014-09-01

    Despite the increasing prevalence of CKD in the United States, there is a declining interest among United States medical graduates in nephrology as a career choice. Effective programs are needed to generate interest at early educational stages when career choices can be influenced. The Kidney Disease Screening and Awareness Program (KDSAP) is a novel program initiated at Harvard College that increases student knowledge of and interest in kidney health and disease, interest in nephrology career paths, and participation in kidney disease research. This model, built on physician mentoring, kidney screening of underserved populations, direct interactions with kidney patients, and opportunities to participate in kidney research, can be reproduced and translated to other workforce-challenged subspecialties. Copyright © 2014 by the American Society of Nephrology.

  5. The Chronic Kidney Disease Model: A General Purpose Model of Disease Progression and Treatment

    Directory of Open Access Journals (Sweden)

    Patel Uptal D

    2011-06-01

    Full Text Available Abstract Background Chronic kidney disease (CKD is the focus of recent national policy efforts; however, decision makers must account for multiple therapeutic options, comorbidities and complications. The objective of the Chronic Kidney Disease model is to provide guidance to decision makers. We describe this model and give an example of how it can inform clinical and policy decisions. Methods Monte Carlo simulation of CKD natural history and treatment. Health states include myocardial infarction, stroke with and without disability, congestive heart failure, CKD stages 1-5, bone disease, dialysis, transplant and death. Each cycle is 1 month. Projections account for race, age, gender, diabetes, proteinuria, hypertension, cardiac disease, and CKD stage. Treatment strategies include hypertension control, diabetes control, use of HMG-CoA reductase inhibitors, use of angiotensin converting enzyme inhibitors, nephrology specialty care, CKD screening, and a combination of these. The model architecture is flexible permitting updates as new data become available. The primary outcome is quality adjusted life years (QALYs. Secondary outcomes include health state events and CKD progression rate. Results The model was validated for GFR change/year -3.0 ± 1.9 vs. -1.7 ± 3.4 (in the AASK trial, and annual myocardial infarction and mortality rates 3.6 ± 0.9% and 1.6 ± 0.5% vs. 4.4% and 1.6% in the Go study. To illustrate the model's utility we estimated lifetime impact of a hypothetical treatment for primary prevention of vascular disease. As vascular risk declined, QALY improved but risk of dialysis increased. At baseline, 20% and 60% reduction: QALYs = 17.6, 18.2, and 19.0 and dialysis = 7.7%, 8.1%, and 10.4%, respectively. Conclusions The CKD Model is a valid, general purpose model intended as a resource to inform clinical and policy decisions improving CKD care. Its value as a tool is illustrated in our example which projects a relationship between

  6. Supernova Remnant in 3-D

    Science.gov (United States)

    2009-01-01

    of the wavelength shift is related to the speed of motion, one can determine how fast the debris are moving in either direction. Because Cas A is the result of an explosion, the stellar debris is expanding radially outwards from the explosion center. Using simple geometry, the scientists were able to construct a 3-D model using all of this information. A program called 3-D Slicer modified for astronomical use by the Astronomical Medicine Project at Harvard University in Cambridge, Mass. was used to display and manipulate the 3-D model. Commercial software was then used to create the 3-D fly-through. The blue filaments defining the blast wave were not mapped using the Doppler effect because they emit a different kind of light synchrotron radiation that does not emit light at discrete wavelengths, but rather in a broad continuum. The blue filaments are only a representation of the actual filaments observed at the blast wave. This visualization shows that there are two main components to this supernova remnant: a spherical component in the outer parts of the remnant and a flattened (disk-like) component in the inner region. The spherical component consists of the outer layer of the star that exploded, probably made of helium and carbon. These layers drove a spherical blast wave into the diffuse gas surrounding the star. The flattened component that astronomers were unable to map into 3-D prior to these Spitzer observations consists of the inner layers of the star. It is made from various heavier elements, not all shown in the visualization, such as oxygen, neon, silicon, sulphur, argon and iron. High-velocity plumes, or jets, of this material are shooting out from the explosion in the plane of the disk-like component mentioned above. Plumes of silicon appear in the northeast and southwest, while those of iron are seen in the southeast and north. These jets were already known and Doppler velocity measurements have been made for these structures, but their orientation and

  7. Embryonic kidney function in a chronic renal failure model in rodents.

    Science.gov (United States)

    Fujimoto, Eisuke; Yamanaka, Shuichiro; Kurihara, Sho; Tajiri, Susumu; Izuhara, Luna; Katsuoka, Yuichi; Yokote, Shinya; Matsumoto, Kei; Kobayashi, Eiji; Okano, Hirotaka James; Chikaraishi, Tatsuya; Yokoo, Takashi

    2017-08-01

    Rapid advancements have been made in alternative treatments for renal diseases. Our goal for renal regeneration is to establish a kidney graft derived from human embryonic tissues. In this study, we investigated the effects of host renal failure on the structure and activity of transplanted embryonic kidney and bladder, and found that diuretics effectively induced urine production in the transplanted kidney. Uremic conditions were reproduced using a 5/6 renal infarction rat model. An embryonic kidney plus bladder (embryonic day 15) was isolated from a pregnant Lewis rat and transplanted into the para-aortic area of a 5/6 renal-infarcted Lewis rat. Following growth, the embryonic bladder was successfully anastomosed to the host ureter. We assessed graft function in terms of survival rates and found no differences between normal (n = 5) and renal failure (n = 8) groups (median survival: 70.5 vs 74.5 h; p = 0.331) in terms of survival, indicating that the grafts prolonged rat survival, even under renal failure conditions. Furosemide (n = 9) significantly increased urine volume compared with saline-treated controls (n = 7; p < 0.05), confirming that the grafts were functional. We also demonstrated the possibilities of an in vivo imaging system for determining the viability of transplanted embryonic kidney with bladder. The results of this study demonstrate that transplanted embryonic kidney and bladder can grow and function effectively, even under uremic conditions.

  8. Betulinic acid attenuates renal fibrosis in rat chronic kidney disease model.

    Science.gov (United States)

    Sharma, Anshuk; Thakur, Richa; Lingaraju, Madhu C; Kumar, Dhirendra; Mathesh, Karikalan; Telang, Avinash G; Singh, Thakur Uttam; Kumar, Dinesh

    2017-05-01

    Most chronic kidney diseases (CKDs), regardless of the nature of the initial injury, progress to end-stage renal disease (ESRD) characterized by fibrosis with irreversible loss of tissue and function. Thus, improved and more effective therapies are critical. Betulinic acid (BA), a pentacyclic triterpene is a compound in the pipeline of anti-cancer drug development. It has been shown to a possess variety of beneficial effects in many disease conditions. However, its efficacy against CKD is yet to be explored. The present study was undertaken to investigate the effect of BA on renal fibrosis in the rat model of adenine-induced CKD. CKD rats gained significantly less weight during the experimental period when compared to control rats and BA treatment did not significantly increase the weight gain in CKD rats. CKD rats showed elevated levels of serum blood urea nitrogen (BUN), creatinine and uric acid along with increased levels of kidney injury markers such as cystatin C and neutrophil gelatinase-associated lipocalin (NGAL). Further, in comparison to control rats, kidney samples from CKD rats revealed increased profibrotic protein levels like transforming growth factor-beta (TGF-β), connective tissue growth factor (CTGF), fibronectin, collagen type I and hydroxyproline indicating a progressive fibrotic response. These data are further fortified by histological findings where kidney damage and fibrosis are clearly evident as dilatation of tubules, glomerular degeneration and vacuolation along with deposition of collagen fibers. However, the above-mentioned findings in CKD rats were significantly reversed by BA-treatment revealing its nephroprotective potential and anti-fibrotic activity. The biochemical mechanism of the nephroprotective and anti-fibrotic effect of BA in the adenine-induced CKD rats might be mediated by inhibition of pro-fibrotic protein production thereby hindering the kidney tissue damage along with improvement in kidney function. Thus, BA could be

  9. Understanding Thiel embalming in pig kidneys to develop a new circulation model.

    Directory of Open Access Journals (Sweden)

    Wouter Willaert

    Full Text Available The quality of tissue preservation in Thiel embalmed bodies varies. Research on the administered embalming volume and its vascular distribution may elucidate one of the mechanisms of tissue preservation and allow for new applications of Thiel embalming. Vascular embalming with (group 1, n = 15 or without (group 2, n = 20 contrast agent was initiated in pig kidneys. The distribution of Thiel embalming solution in group 1 was visualized using computed tomography. The kidneys in both groups were then immersed in concentrated salt solutions to reduce their weight and volume. Afterwards, to mimic a lifelike circulation in the vessels, group 2 underwent pump-driven reperfusion for 120 minutes with either paraffinum perliquidum or diluted polyethylene glycol. The circulation was imaged with computed tomography. All of the kidneys were adequately preserved. The embalming solution spread diffusely in the kidney, but fluid accumulation was present. Subsequent immersion in concentrated salt solutions reduced weight (P < 0.01 and volume (P < 0.01. Reperfusion for 120 minutes was established in group 2. Paraffinum perliquidum filled both major vessels and renal tissue, whereas diluted polyethylene glycol spread widely in the kidney. There were no increases in weight (P = 0.26 and volume (P = 0.79; and pressure further decreased (P = 0.032 after more than 60 minutes of reperfusion with paraffinum perliquidum, whereas there were increases in weight (P = 0.005, volume (P = 0.032 and pressure (P < 0.0001 after reperfusion with diluted polyethylene glycol. Arterial embalming of kidneys results in successful preservation due to complete parenchymatous spreading. More research is needed to determine whether other factors affect embalming quality. Dehydration is an effective method to regain the organs' initial status. Prolonged vascular reperfusion with paraffinum perliquidum can be established in this model without increases in weight, volume and pressure.

  10. Einstein Observations of Galactic supernova remnants

    Science.gov (United States)

    Seward, Frederick D.

    1990-01-01

    This paper summarizes the observations of Galactic supernova remnants with the imaging detectors of the Einstein Observatory. X-ray surface brightness contours of 47 remnants are shown together with gray-scale pictures. Count rates for these remnants have been derived and are listed for the HRI, IPC, and MPC detectors.

  11. Glibenclamide improves kidney and heart structure and function in the adenine-diet model of chronic kidney disease.

    Science.gov (United States)

    Diwan, Vishal; Gobe, Glenda; Brown, Lindsay

    2014-01-01

    The development of chronic kidney disease (CKD) and associated cardiovascular disease involves free radical damage and inflammation. Addition of adenine to the diet induces inflammation followed by CKD and cardiovascular disease. NOD-like receptor protein-3 (NLRP-3) is pro-inflammatory in the kidney; glibenclamide inhibits production of NLRP-3. Male Wistar rats were fed either control rat food or adenine (0.25%) in this food for 16 weeks. Glibenclamide (10 mg/kg/day) was administered to two groups with and without adenine for the final 8 weeks. Kidney function (blood urea nitrogen/BUN, plasma creatinine/PCr, plasma uric acid, proteinuria), kidney structure (fibrosis, inflammation), cardiovascular parameters (blood pressure, left ventricular stiffness, vascular responses and echocardiography) and protein expression of markers for oxidative stress (HO-1), and inflammation (TNF-α, NLRP-3) were assessed. In adenine-fed rats, glibenclamide decreased BUN (controls: 6±0.6; adenine: 56.6±5.4; adenine+glibenclamide: 19.4±2.7 mmol/L), PCr (controls: 42±2.8; adenine: 268±23; adenine+glibenclamide: 81±10 μmol/L), proteinuria (controls: 150±7.4; adenine: 303±19; adenine+glibenclamide: 220±13 μmol/L) (all pchronic inflammatory cells, fibrosis, tubular damage and expression of HO-1, TNF-α and NLRP-3 in the kidney. Glibenclamide did not alter plasma uric acid concentrations (controls: 38±1; adenine: 63±4; adenine+glibenclamide: 69±14 μmol/L). Cardiovascular changes included decreased systolic blood pressure and improved vascular responses although cardiac fibrosis, left ventricular stiffness and hypertrophy were not reduced. Glibenclamide improved kidney structure and function in CKD and decreased some cardiovascular parameters. Inflammatory markers and cell populations were attenuated by glibenclamide in kidneys. Copyright © 2013 Elsevier Ltd. All rights reserved.

  12. Risk prediction models for acute kidney injury following major noncardiac surgery: systematic review.

    Science.gov (United States)

    Wilson, Todd; Quan, Samuel; Cheema, Kim; Zarnke, Kelly; Quinn, Rob; de Koning, Lawrence; Dixon, Elijah; Pannu, Neesh; James, Matthew T

    2016-02-01

    Acute kidney injury (AKI) is a serious complication of major noncardiac surgery. Risk prediction models for AKI following noncardiac surgery may be useful for identifying high-risk patients to target with prevention strategies. We conducted a systematic review of risk prediction models for AKI following major noncardiac surgery. MEDLINE, EMBASE, BIOSIS Previews and Web of Science were searched for articles that (i) developed or validated a prediction model for AKI following major noncardiac surgery or (ii) assessed the impact of a model for predicting AKI following major noncardiac surgery that has been implemented in a clinical setting. We identified seven models from six articles that described a risk prediction model for AKI following major noncardiac surgeries. Three studies developed prediction models for AKI requiring renal replacement therapy following liver transplantation, three derived prediction models for AKI based on the Risk, Injury, Failure, Loss of kidney function, End-stage kidney disease (RIFLE) criteria following liver resection and one study developed a prediction model for AKI following major noncardiac surgical procedures. The final models included between 4 and 11 independent variables, and c-statistics ranged from 0.79 to 0.90. None of the models were externally validated. Risk prediction models for AKI after major noncardiac surgery are available; however, these models lack validation, studies of clinical implementation and impact analyses. Further research is needed to develop, validate and study the clinical impact of such models before broad clinical uptake. © The Author 2015. Published by Oxford University Press on behalf of ERA-EDTA. All rights reserved.

  13. Creating computer aided 3D model of spleen and kidney based on Visible Human Project.

    Science.gov (United States)

    Aldur, Muhammet M

    2005-01-01

    To investigate the efficacy of computer aided 3-dimensional (3D) reconstruction technique on visualization and modeling of gross anatomical structures with an affordable methodology applied on the spleen and kidney. From The Visible Human Project Dataset cryosection images, developed by the National Library of Medicine, the spleen and kidney sections were preferred to be used due to their highly distinct contours. The software used for the reconstruction were SurfDriver 3.5.3 for Mac and Cinema 4D XL version 7.1 for Mac OS X. This study was carried out in May 2004 at the Department of Anatomy, Hacettepe University, Ankara, Turkey. As a result of this study, it is determined that these 2 programs could be effectively used both for 3D modeling of the mentioned organs and volumetric analyses on these models. It is also seen that it is possible to hold the physical models of these gross anatomical digital ones with stereolithography technique by means of the data exchange file format provided by the program and present such images as anaglyph. SurfDriver 3.5.3 for Mac OS and Cinema 4 DXL version 7.1 for Mac OS X can be used effectively for reconstruction of gross anatomical structures from serial parallel sections with distinct contours such as spleen and kidney and the animation of models. These software constitute a highly effective way of getting volumetric calculations, spatial relations and morphometrical measurements of reconstructed structures.

  14. Animal models of pediatric chronic kidney disease. Is adenine intake an appropriate model?

    Science.gov (United States)

    Claramunt, Débora; Gil-Peña, Helena; Fuente, Rocío; Hernández-Frías, Olaya; Santos, Fernando

    2015-01-01

    Pediatric chronic kidney disease (CKD) has peculiar features. In particular, growth impairment is a major clinical manifestation of CKD that debuts in pediatric age because it presents in a large proportion of infants and children with CKD and has a profound impact on the self-esteem and social integration of the stunted patients. Several factors associated with CKD may lead to growth retardation by interfering with the normal physiology of growth plate, the organ where longitudinal growth rate takes place. The study of growth plate is hardly possible in humans and justifies the use of animal models. Young rats made uremic by 5/6 nephrectomy have been widely used as a model to investigate growth retardation in CKD. This article examines the characteristics of this model and analyzes the utilization of CKD induced by high adenine diet as an alternative research protocol. Copyright © 2015 Sociedad Española de Nefrología. Published by Elsevier España, S.L.U. All rights reserved.

  15. The metabolic profile of a rat model of chronic kidney disease

    Directory of Open Access Journals (Sweden)

    Yohei Tanada

    2017-05-01

    Full Text Available Background The kidney is always subjected to high metabolic demand. The aim of this study was to characterize metabolic profiles of a rat model of chronic kidney disease (CKD with cardiorenal syndrome (CRS induced by prolonged hypertension. Methods We used inbred male Dahl salt-sensitive (DS rats fed an 8% NaCl diet from six weeks of age (high-salt; HS group or a 0.3% NaCl diet as controls (low-salt; LS group. We analyzed function, pathology, metabolome, and the gene expression related to energy metabolism of the kidney. Results DS rats with a high-salt diet showed hypertension at 11 weeks of age and elevated serum levels of creatinine and blood urea nitrogen with heart failure at 21 weeks of age. The fibrotic area in the kidneys increased at 21 weeks of age. In addition, gene expression related to mitochondrial function was largely decreased. The levels of citrate and isocitrate increased and the gene expression of alpha-ketoglutaratedehydrogenase and succinyl-CoA synthetase decreased; these are enzymes that metabolize citrate and isocitrate, respectively. In addition, the levels of succinate and acetyl Co-A, both of which are metabolites of the tricarboxylic acid (TCA cycle, decreased. Conclusions DS rats fed a high-salt diet were deemed a suitable model of CKD with CRS. Gene expression and metabolites related to energy metabolism and mitochondria in the kidney significantly changed in DS rats with hypertension in accordance with the progression of renal injury.

  16. Caenorhabditis elegans, a model organism for kidney research: from cilia to mechanosensation and longevity.

    Science.gov (United States)

    Müller, Roman-Ulrich; Zank, Sibylle; Fabretti, Francesca; Benzing, Thomas

    2011-07-01

    The introduction of Caenorhabditis elegans by Sydney Brenner to study 'how genes might specify the complex structures found in higher organisms' revolutionized molecular and developmental biology and pioneered a new research area to study organ development and cellular differentiation with this model organism. Here, we review the role of the nematode in renal research and discuss future perspectives for its use in molecular nephrology. Although C. elegans does not possess an excretory system comparable with the mammalian kidney, various studies have demonstrated the conserved functional role of kidney disease genes in C. elegans. The finding that cystic kidney diseases can be considered ciliopathies is based to a great extent on research studying their homologues in the nematode's ciliated neurons. Moreover, proteins of the kidney filtration barrier play important roles in both correct synapse formation, mechanosensation and signal transduction in the nematode. Intriguingly, the renal cell carcinoma disease gene product von-Hippel-Lindau protein was shown to regulate lifespan in the nematode. Last but not least, the worm's excretory system itself expresses genes involved in electrolyte and osmotic homeostasis and may serve as a valuable tool to study these processes on a molecular level. C. elegans has proven to be an incredibly powerful tool in studying various aspects of renal function, development and disease and will certainly continue to do so in the future.

  17. Curative effect of sesame oil in a rat model of chronic kidney disease.

    Science.gov (United States)

    Liu, Chuan-Teng; Chien, Se-Ping; Hsu, Dur-Zong; Periasamy, Srinivasan; Liu, Ming-Yie

    2015-12-01

    Chronic kidney disease causes a progressive and irreversible loss of renal function. We investigated the curative effect of sesame oil, a natural, nutrient-rich, potent antioxidant, in a rat model of chronic kidney disease. Chronic kidney disease was induced by subcutaneously injecting uni-nephrectomized rats with deoxycorticosterone acetate (DOCA) and 1% NaCl [DOCA/salt] in drinking water. Four weeks later, the rats were gavaged with sesame oil (0.5 or 1 mL/kg per day) for 7 days. Renal injury, histopathological changes, hydroxyl radical, peroxynitrite, lipid peroxidation, Nrf2, osteopontin expression, and collagen were assessed 24 h after the last dose of sesame oil. Blood urea nitrogen, creatinine, urine volume, and albuminuria were significantly higher in the DOCA/salt treated rats than in control rats. Sesame oil significantly decreased these four tested parameters in DOCA/salt treated rats. In addition, creatinine clearance rate and nuclear Nrf2 expression were significantly decreased in the DOCA/salt treated rats compared to control rats. Sesame oil significantly decreased hydroxyl radical, peroxynitrite level, lipid peroxidation, osteopontin, and renal collagen deposition, but increased creatinine clearance rate and nuclear Nrf2 expression in DOCA/salt treated rats. We conclude that supplementation of sesame oil mitigates DOCA/salt induced chronic kidney disease in rats by activating Nrf2 and attenuating osteopontin expression and inhibiting renal fibrosis in rats. © 2015 Asian Pacific Society of Nephrology.

  18. Optical coherence tomography (OCT) of a murine model of chronic kidney disease

    Science.gov (United States)

    Wang, Hsing-Wen; Guo, Hengchang; Andrews, Peter M.; Anderson, Erik; Chen, Y.

    2015-03-01

    Chronic Kidney Disease (CKD) is characterized by a progressive loss in renal function over time. Pathology can provide valuable insights into the progression of CKD by analyzing the status of glomeruli and the uriniferous tubules over time. Optical coherence tomography (OCT) is a new procedure that can analyze the microscopic structure of the kidney in a non-invasive manner. This is especially important because there are significant artifacts associated with excision biopsies and immersion fixation procedures. Recently, we have shown that OCT can provide real time images of kidney microstructure and Doppler OCT (DOCT) can image glomerular renal blood flow in vivo without administrating exogenous contrast agents. In this study, we used OCT to evaluate CKD in a model induced by intravenous Adriamycin injection into Munich-Wistar rats. We evaluated tubular density and tubular diameter from OCT images at several post- Adriamycin induction time points and compared them with conventional light microscopic histological imaging. Proteinurea and serum creatinine were used as physiological markers of the extent of CKD. Preliminary OCT results revealed changes in tubular density due to tubular necrosis and interstitial fibrosis within the first 4 weeks following Adriamycin injection. From week 4 to 8 after Adriamycin induction, changes in tubular density and diameter occurred due to both tubular loss and tubular dilation. The results suggest OCT can provide additional information about kidney histopathology in CKD. DOCT revealed reduced blood flow in some glomeruli probably as a consequence of focal glomerularsclerosis.

  19. Human recombinant erythropoietin reduces sensorimotor dysfunction and cognitive impairment in rat models of chronic kidney disease.

    Science.gov (United States)

    Reza-Zaldívar, E E; Sandoval-Avila, S; Gutiérrez-Mercado, Y K; Vázquez-Méndez, E; Canales-Aguirre, A A; Esquivel-Solís, H; Gómez-Pinedo, U; Márquez-Aguirre, A L

    2017-11-10

    Chronic kidney disease (CKD) can cause anaemia and neurological disorders. Recombinant human erythropoietin (rHuEPO) is used to manage anaemia in CKD. However, there is little evidence on the effects of rHuEPO on behaviour and cognitive function in CKD. This study aimed to evaluate the impact of rHuEPO in sensorimotor and cognitive functions in a CKD model. Male Wistar rats were randomly assigned to 4 groups: control and CKD, with and without rHuEPO treatment (1050 IU per kg body weight, once weekly for 4 weeks). The Morris water maze, open field, and adhesive removal tests were performed simultaneously to kidney damage induction and treatment. Markers of anaemia and renal function were measured at the end of the study. Treatment with rHuEPO reduced kidney damage and corrected anaemia in rats with CKD. We observed reduced sensorimotor dysfunction in animals with CKD and treated with rHuEPO. These rats also completed the water maze test in a shorter time than the control groups. rHuEPO reduces kidney damage, corrects anemia, and reduces sensorimotor and cognitive dysfunction in animals with CKD. Copyright © 2017 Sociedad Española de Neurología. Publicado por Elsevier España, S.L.U. All rights reserved.

  20. Increased susceptibility to structural acute kidney injury in a mouse model of presymptomatic cardiomyopathy.

    Science.gov (United States)

    Pleasant, LaTawnya; Ma, Qing; Devarajan, Mahima; Parameswaran, Priyanka; Drake, Keri; Siroky, Brian; Shay-Winkler, Kritton; Robbins, Jeffrey; Devarajan, Prasad

    2017-09-01

    The early events that signal renal dysfunction in presymptomatic heart failure are unclear. We tested the hypothesis that functional and mechanistic changes occur in the kidney that precede the development of symptomatic heart failure. We employed a transgenic mouse model with cardiomyocyte-specific overexpression of mutant α-B-crystallin that develops slowly progressive cardiomyopathy. Presymptomatic transgenic mice displayed an increase in serum creatinine (1.17 ± 0.34 vs. wild type 0.65 ± 0.16 mg/dl, P kidneys exhibited a twofold upregulation of the Ren1 gene, marked overexpression of renin protein in the tubules, and a worsened response to ischemia-reperfusion injury based on serum creatinine (2.77 ± 0.66 in transgenic mice vs. 2.01 ± 0.58 mg/dl in wild type, P kidney that occur in early presymptomatic heart failure, which increase the susceptibility to subsequent acute kidney injury. Copyright © 2017 the American Physiological Society.

  1. Kidney Quiz

    Science.gov (United States)

    ... NKF Kidney Disease Community Featured Story African Americans & Kidney Disease Did you know that African Americans are ... checks Your Kidneys and You Meetings Featured Story Kidney Walk The Kidney Walk is the nation's largest ...

  2. HI Absorption in Merger Remnants

    Science.gov (United States)

    Teng, Stacy H.; Veileux, Sylvain; Baker, Andrew J.

    2012-01-01

    It has been proposed that ultraluminous infrared galaxies (ULIRGs) pass through a luminous starburst phase, followed by a dust-enshrouded AGN phase, and finally evolve into optically bright "naked" quasars once they shed their gas/dust reservoirs through powerful wind events. We present the results of our recent 21- cm HI survey of 21 merger remnants with the Green Bank Telescope. These remnants were selected from the QUEST (Quasar/ULIRG Evolution Study) sample of ULIRGs and PG quasars; our targets are all bolometrically dominated by AGN and sample all phases of the proposed ULIRG -> IR-excess quasar -> optical quasar sequence. We explore whether there is an evolutionary connection between ULIRGs and quasars by looking for the occurrence of HI absorption tracing neutral gas outflows; our results will allow us to identify where along the sequence the majority of a merger's gas reservoir is expelled.

  3. Reference values and physiological characterization of a specific isolated pig kidney perfusion model

    Directory of Open Access Journals (Sweden)

    Meissler Michael

    2007-01-01

    Full Text Available Abstract Background Models of isolated and perfused kidneys are used to study the effects of drugs, hazardous or toxic substances on renal functions. Since physiological and morphological parameters of small laboratory animal kidneys are difficult to compare to human renal parameters, porcine kidney perfusion models have been developed to simulate closer conditions to the human situation, but exact values of renal parameters for different collection and perfusion conditions have not been reported so far. If the organs could be used out of regular slaughtering processes animal experiments may be avoided. Methods To assess renal perfusion quality, we analyzed different perfusion settings in a standardized model of porcine kidney hemoperfusion with organs collected in the operating theatre (OP: groups A-D or in a public abattoir (SLA: group E and compared the data to in vivo measurements in living animals (CON. Experimental groups had defined preservation periods (0, 2 and 24 hrs, one with additional albumin in the perfusate (C for edema reduction. Results Varying perfusion settings resulted in different functional values (mean ± SD: blood flow (RBF [ml/min*100 g]: (A 339.9 ± 61.1; (C 244.5 ± 53.5; (D 92.8 ± 25.8; (E 153.8 ± 41.5; glomerular fitration (GFR [ml/min*100 g]: (CON 76.1 ± 6.2; (A 59.2 ± 13.9; (C 25.0 ± 10.6; (D 1.6 ± 1.3; (E 16.3 ± 8.2; fractional sodium reabsorption (RFNa [%] (CON 99.8 ± 0.1; (A 82.3 ± 8.1; (C 86.8 ± 10.3; (D 38.4 ± 24.5; (E 88.7 ± 5.8. Additionally the tubular coupling-ratio of Na-reabsorption/O2-consumption was determined (TNa/O2-cons [mmol-Na/mmol- O2] (CON 30.1; (A 42.0, (C 80.6; (D 17.4; (E 23.8, exhibiting OP and SLA organs with comparable results. Conclusion In the present study functional values for isolated kidneys with different perfusion settings were determined to assess organ perfusion quality. It can be summarized that the hemoperfused porcine kidney can serve as a biological model with

  4. A Possible Zebrafish Model of Polycystic Kidney Disease: Knockdown of wnt5a Causes Cysts in Zebrafish Kidneys

    OpenAIRE

    Huang, Liwei; Xiao, An; Wecker, Andrea; McBride, Daniel A.; Choi, Soo Young; Zhou, Weibin; Lipschutz, Joshua H.

    2014-01-01

    Polycystic kidney disease (PKD) is one of the most common causes of end-stage kidney disease, a devastating disease for which there is no cure. The molecular mechanisms leading to cyst formation in PKD remain somewhat unclear, but many genes are thought to be involved. Wnt5a is a non-canonical glycoprotein that regulates a wide range of developmental processes. Wnt5a works through the planar cell polarity (PCP) pathway that regulates oriented cell division during renal tubular cell elongation...

  5. Calibration drift in regression and machine learning models for acute kidney injury.

    Science.gov (United States)

    Davis, Sharon E; Lasko, Thomas A; Chen, Guanhua; Siew, Edward D; Matheny, Michael E

    2017-11-01

    Predictive analytics create opportunities to incorporate personalized risk estimates into clinical decision support. Models must be well calibrated to support decision-making, yet calibration deteriorates over time. This study explored the influence of modeling methods on performance drift and connected observed drift with data shifts in the patient population. Using 2003 admissions to Department of Veterans Affairs hospitals nationwide, we developed 7 parallel models for hospital-acquired acute kidney injury using common regression and machine learning methods, validating each over 9 subsequent years. Discrimination was maintained for all models. Calibration declined as all models increasingly overpredicted risk. However, the random forest and neural network models maintained calibration across ranges of probability, capturing more admissions than did the regression models. The magnitude of overprediction increased over time for the regression models while remaining stable and small for the machine learning models. Changes in the rate of acute kidney injury were strongly linked to increasing overprediction, while changes in predictor-outcome associations corresponded with diverging patterns of calibration drift across methods. Efficient and effective updating protocols will be essential for maintaining accuracy of, user confidence in, and safety of personalized risk predictions to support decision-making. Model updating protocols should be tailored to account for variations in calibration drift across methods and respond to periods of rapid performance drift rather than be limited to regularly scheduled annual or biannual intervals.

  6. SPI Analysis of the Supernova Remnant DEM L71

    Science.gov (United States)

    Frank, Kari A.; Dwarkadas, Vikram; Burrows, David N.; Aisyah Mansoor, Siti; Crum, Ryan M.

    2017-08-01

    Supernova remnants are complex, three-dimensional objects; properly accounting for this complexity when modeling the resulting X-ray emission presents quite a challenge and makes it difficult to accurately characterize the properties of the full SNR volume. The SPIES (Smoothed Particle Inference Exploration of Supernova Remnants) project aims to address this challenge by applying a fundamentally different approach to analyzing X-ray observations of SNRs. Smoothed Particle Inference (SPI) is a Bayesian modeling process that fits a population of gas blobs ("smoothed particles") such that their superposed emission reproduces the observed spatial and spectral distribution of photons. We present here the results of an SPI analysis of the Type Ia supernova remnant DEM L71. Among other results, we find that despite its regular appearance, the temperature and other parameter maps exhibit irregular substructure.

  7. A Python Calculator for Supernova Remnant Evolution

    Science.gov (United States)

    Leahy, D. A.; Williams, J. E.

    2017-05-01

    A freely available Python code for modeling supernova remnant (SNR) evolution has been created. This software is intended for two purposes: to understand SNR evolution and to use in modeling observations of SNR for obtaining good estimates of SNR properties. It includes all phases for the standard path of evolution for spherically symmetric SNRs. In addition, alternate evolutionary models are available, including evolution in a cloudy ISM, the fractional energy-loss model, and evolution in a hot low-density ISM. The graphical interface takes in various parameters and produces outputs such as shock radius and velocity versus time, as well as SNR surface brightness profile and spectrum. Some interesting properties of SNR evolution are demonstrated using the program.

  8. Predictive Score Model for Delayed Graft Function Based on Easily Available Variables before Kidney Donation after Cardiac Death

    Directory of Open Access Journals (Sweden)

    Chen-Guang Ding

    2017-01-01

    Conclusions: The scoring model might be a good noninvasive tool for assessing the quality of DCD kidneys before donation and potentially useful for physicians to make optimal decisions about donor organ offers.

  9. A Classification Model to Predict the Rate of Decline of Kidney Function.

    Science.gov (United States)

    Subasi, Ersoy; Subasi, Munevver Mine; Hammer, Peter L; Roboz, John; Anbalagan, Victor; Lipkowitz, Michael S

    2017-01-01

    The African American Study of Kidney Disease and Hypertension (AASK), a randomized double-blinded treatment trial, was motivated by the high rate of hypertension-related renal disease in the African-American population and the scarcity of effective therapies. This study describes a pattern-based classification approach to predict the rate of decline of kidney function using surface-enhanced laser desorption ionization/time of flight proteomic data from rapid and slow progressors classified by rate of change in glomerular filtration rate. An accurate classification model consisting of 7 out of 5,751 serum proteomic features is constructed by applying the logical analysis of data (LAD) methodology. On cross-validation by 10-folding, the model was shown to have an accuracy of 80.6 ± 0.11%, sensitivity of 78.4 ± 0.17%, and specificity of 78.5 ± 0.16%. The LAD discriminant is used to identify the patients in different risk groups. The LAD risk scores assigned to 116 AASK patients generated a receiver operating curves curve with AUC 0.899 (CI 0.845-0.953) and outperforms the risk scores assigned by proteinuria, one of the best predictors of chronic kidney disease progression.

  10. A Classification Model to Predict the Rate of Decline of Kidney Function

    Directory of Open Access Journals (Sweden)

    Ersoy Subasi

    2017-07-01

    Full Text Available The African American Study of Kidney Disease and Hypertension (AASK, a randomized double-blinded treatment trial, was motivated by the high rate of hypertension-related renal disease in the African-American population and the scarcity of effective therapies. This study describes a pattern-based classification approach to predict the rate of decline of kidney function using surface-enhanced laser desorption ionization/time of flight proteomic data from rapid and slow progressors classified by rate of change in glomerular filtration rate. An accurate classification model consisting of 7 out of 5,751 serum proteomic features is constructed by applying the logical analysis of data (LAD methodology. On cross-validation by 10-folding, the model was shown to have an accuracy of 80.6 ± 0.11%, sensitivity of 78.4 ± 0.17%, and specificity of 78.5 ± 0.16%. The LAD discriminant is used to identify the patients in different risk groups. The LAD risk scores assigned to 116 AASK patients generated a receiver operating curves curve with AUC 0.899 (CI 0.845–0.953 and outperforms the risk scores assigned by proteinuria, one of the best predictors of chronic kidney disease progression.

  11. Pioglitazone Attenuates Cystic Burden in the PCK Rodent Model of Polycystic Kidney Disease

    Directory of Open Access Journals (Sweden)

    Bonnie L. Blazer-Yost

    2010-01-01

    Full Text Available Polycystic kidney disease (PKD is a genetic disorder characterized by growth of fluid-filled cysts predominately in kidney tubules and liver bile ducts. Currently, the clinical management of PKD is limited to cyst aspiration, surgical resection or organ transplantation. Based on an observation that PPARγ agonists such as pioglitazone and rosiglitazone decrease mRNA levels of a Cl− transport protein, CFTR (cystic fibrosis transmembrane conductance regulator, and the Cl− secretory response to vasopressin in cultured renal cells, it is hypothesized that PPARγ agonists will inhibit cyst growth. The current studies show that a 7- or 14-week pioglitazone feeding regimen inhibits renal and hepatic bile duct cyst growth in the PCK rat, a rodent model orthologous to human PKD. These studies provide proof of concept for the mechanism of action of the PPARγ agonists and suggest that this class of drugs may be effective in controlling both renal and hepatic cyst growth and fibrosis in PKD.

  12. Exploring Supernova Remnants with the SPIES Project

    Science.gov (United States)

    Frank, Kari A.; Burrows, David N.; Dwarkadas, Vikram

    2017-01-01

    X-ray observations provide a key window into supernova remnants, providing measurements of a plethora of physical properties that are critical for understanding SNRs, their environments, their progenitors, and the SNe that created them. However, characterizing the entire volume of shocked plasma in a SNR is difficult, due to their complicated three dimensional morphologies and spectra. The SPIES project aims to address this problem by applying a novel X-ray analysis method, Smoothed Particle Inference (SPI), to XMM observations of 12 SNRs. SPI is a Bayesian modeling process that fits a population of gas blobs ("smoothed particles") such that their superposed emission reproduces the observed spatial and spectral distribution of photons. Emission-weighted distributions and maps of plasma properties, such as abundances and temperatures, are then extracted from the properties of the individual blobs. Additionally, because the collection of blobs is a multi-dimensional representation of the shocked plasma, we can carry out a more detailed exploration of plasma properties by extracting any subset of the blobs (e.g. those with the highest temperatures) and investigating its properties (e.g. map the abundances). Here we present preliminary results from SPI analyses of the first 6 remnants in the SPIES project.

  13. Mechanism of insulin resistance in a rat model of kidney disease and the risk of developing type 2 diabetes.

    Directory of Open Access Journals (Sweden)

    François Dion

    Full Text Available Chronic kidney disease is associated with homeostatic imbalances such as insulin resistance. However, the underlying mechanisms leading to these imbalances and whether they promote the development of type 2 diabetes is unknown. The effect of chronic kidney disease on insulin resistance was studied on two different rat strains. First, in a 5/6th nephrectomised Sprague-Dawley rat model of chronic kidney disease, we observed a correlation between the severity of chronic kidney disease and hyperglycemia as evaluated by serum fructosamine levels (p<0.0001. Further, glucose tolerance tests indicated an increase of 25% in glycemia in chronic kidney disease rats (p<0.0001 as compared to controls whereas insulin levels remained unchanged. We also observed modulation of glucose transporters expression in several tissues such as the liver (decrease of ≈40%, p≤0.01 and muscles (decrease of ≈29%, p≤0.05. Despite a significant reduction of ≈37% in insulin-dependent glucose uptake in the muscles of chronic kidney disease rats (p<0.0001, the development of type 2 diabetes was never observed. Second, in a rat model of metabolic syndrome (Zucker Leprfa/fa, chronic kidney disease caused a 50% increased fasting hyperglycemia (p<0.0001 and an exacerbated glycemic response (p<0.0001 during glucose challenge. Similar modulations of glucose transporters expression and glucose uptake were observed in the two models. However, 30% (p<0.05 of chronic kidney disease Zucker rats developed characteristics of type 2 diabetes. Thus, our results suggest that downregulation of GLUT4 in skeletal muscle may be associated with insulin resistance in chronic kidney disease and could lead to type 2 diabetes in predisposed animals.

  14. Rapid 3D human ribcage and kidney modeling for transcostal HIFU surgery

    Science.gov (United States)

    Cao, Rui; Gao, Jing; Melzer, Andreas; Nabi, Ghulam; Huang, Zhihong

    2012-11-01

    A rapid modeling technique for constructing human ribcage and kidney models for high intensity focused ultrasound through the ribcage is proposed and tested. In this study, a 3D model reconstructed from a patient's CT images provides solutions for the conversion of 3D image data into multi-part volumetric models of kidney and ribcage. The model was imported into PZFlex for simulation of acoustic field analysis. Tissue mimicking materials for the phantom were selected based on the acoustic characterisation result. The effect of the ribcage on HIFU sonication and acoustic pressure distribution were measured in the focal plane. Porcine ribcage sample was used in experiments for comparison. Results showed that with the presence of the ribcage phantom, the maximum temperature at the focus was reduced by approximately 60-70% and the maximum pressure at the focal zone was halved. Focus splitting with the ribcage in place was demonstrated both in experiments and simulations. The development of this model provides basis for using patient's data for transcostal HIFU research and maximise the efficiency of the HIFU surgery.

  15. Remnant cholesterol and ischemic heart disease

    DEFF Research Database (Denmark)

    Varbo, Anette; Nordestgaard, Børge G

    2014-01-01

    PURPOSE OF REVIEW: To review recent advances in the field of remnant cholesterol as a contributor to the development of ischemic heart disease (IHD). RECENT FINDINGS: Epidemiologic, mechanistic, and genetic studies all support a role for elevated remnant cholesterol (=cholesterol in triglyceride......-rich lipoproteins) as a contributor to the development of atherosclerosis and IHD. Observational studies show association between elevated remnant cholesterol and IHD, and mechanistic studies show remnant cholesterol accumulation in the arterial wall like LDL-cholesterol (LDL-C) accumulation. Furthermore, large...... genetic studies show evidence of remnant cholesterol as a causal risk factor for IHD independent of HDL-cholesterol levels. Genetic studies also show that elevated remnant cholesterol is associated with low-grade inflammation, whereas elevated LDL-C is not. There are several pharmacologic ways of lowering...

  16. Motion corrected Cadence CPS ultrasound for quantifying response to vasoactive drugs in a rat kidney model

    Science.gov (United States)

    Pollard, Rachel E.; Dayton, Paul A.; Watson, Katherine D.; Hu, Xiaowen; Guracar, Ismayil M.; Ferrara, Katherine W.

    2009-01-01

    Objective: To establish the ability of contrast enhanced motion corrected Cadence Pulse Sequencing (CPS) to detect changes in renal blood flow induced by vasoactive substances in rats. Methods: Ultrasound contrast media was administered as a constant rate infusion into a phantom at a known rate and CPS data acquired. Rats were anesthetized and pre-drug CPS estimates of replenishment rate were made for the right kidney. Real-time motion correction was applied and parametric images were generated from the CPS data. Group 1 rats (n=7) were administered a vasodilator and Group 2 rats (n=3) were given a vasoconstrictor. CPS imaging of the kidney was repeated following ample time for drug effects to occur. Results: Contrast CPS accurately estimated flow velocity in the phantom model. In addition, CPS defined statistically significant differences between pre and post drug blood flow in the renal medulla (vasodilator, p<0.01; vasoconstrictor, p<0.0001) and cortex (vasoconstrictor, p<0.0001). Conclusions: We conclude that motion corrected CPS ultrasound provides real time quantification of renal blood flow alterations and may prove useful for the assessment of blood flow in transplanted kidneys. PMID:19589583

  17. Supernova 1604, Kepler's supernova, and its remnant

    OpenAIRE

    Vink, Jacco

    2016-01-01

    Supernova 1604 is the last Galactic supernova for which historical records exist. Johannes Kepler's name is attached to it, as he published a detailed account of the observations made by himself and European colleagues. Supernova 1604 was very likely a Type Ia supernova, which exploded 350 pc to 750 pc above the Galactic plane. Its supernova remnant, known as Kepler's supernova remnant, shows clear evidence for interaction with nitrogen-rich material in the north/northwest part of the remnant...

  18. Evaluation of the role of the cannabidiol system in an animal model of ischemia/reperfusion kidney injury.

    Science.gov (United States)

    Soares, Rodrigo Zon; Vuolo, Francieli; Dall'Igna, Dhébora Mozena; Michels, Monique; Crippa, José Alexandre de Souza; Hallak, Jaime Eduardo Cecílio; Zuardi, Antonio Waldo; Dal-Pizzol, Felipe

    2015-01-01

    This work aimed to investigate the effects of the administration of cannabidiol in a kidney ischemia/reperfusion animal model. Kidney injury was induced by 45 minutes of renal ischemia followed by reperfusion. Cannabidiol (5mg/kg) was administered immediately after reperfusion. Ischemia/reperfusion increased the IL-1 and TNF levels, and these levels were attenuated by cannabidiol treatment. Additionally, cannabidiol was able to decrease lipid and protein oxidative damage, but not the nitrite/nitrate levels. Kidney injury after ischemia/reperfusion seemed to be independent of the cannabidiol receptor 1 and cannabidiol receptor 2 (CB1 and CB2) expression levels, as there was no significant increase in these receptors after reperfusion. The cannabidiol treatment had a protective effect against inflammation and oxidative damage in the kidney ischemia/reperfusion model. These effects seemed to be independent of CB1/CB2 receptor activation.

  19. 16 CFR 303.13 - Sale of remnants and products made of remnants.

    Science.gov (United States)

    2010-01-01

    ... provisions of this paragraph shall not apply. (b) Where remnants of fabrics are marketed or handled in bales... paragraph (a) of this section, the individual remnants need not be labeled if the bales, bundles, or...

  20. Supernova Remnants in High Definition

    Science.gov (United States)

    Slane, Patrick; Badenes, Carles; Freyer, Chris; Hughes, Jack; Lee, Herman Shiu-Hang; Lopez, Laura; Patnaude, Daniel; Reynolds, Steve; Temim, Tea; Williams, Brian; Wongwathanarat, Annop; Yamaguchi, Hiroya

    2015-10-01

    As the observable products of explosive stellar death, supernova remnants reveal some of the most direct information on the physics of the explosions, the properties of the progenitor systems, and the demographics of compact objects formed in the supernova events. High sensitivity X-ray observations have allowed us to probe the properties of the shocked plasma, providing constraints on abundances and ionization states that connect directly progenitor masses and metallicities, the nature of the explosions (core-collapse vs. thermonuclear), and the physics of shock heating and particle acceleration in fast shocks. Studies of SNRs in the Magellanic Clouds have provided information on source demographics in a low metallicity environment, and deep searches for point sources in Galactic SNRs imply that many remnants contain rapidly cooling neutron stars or black holes. Based on Chandra observations, we know that crucial measurements required to advance our knowledge in these areas are possible only with much more sensitive observations at high angular resolution. From identifying the effects of particle acceleration on the post-shock gas in young SNRs like Tycho to obtaining spatially resolved spectra - and identifying compact objects - for young SNRs in the Magellanic Clouds, the capabilities of a facility like the X-ray Surveyor are required. Here I present a summary of recent advances brought about by spectral investigations of SNRs, and discuss particular examples of new advances that will be enabled by X-ray Surveyor capabilities.

  1. Development of a physiologically-based computational kidney model to describe the renal excretion of hydrophilic agents in rats

    Directory of Open Access Journals (Sweden)

    Christoph eNiederalt

    2013-01-01

    Full Text Available A physiologically-based kidney model was developed to analyze the renal excretion and kidney exposure of hydrophilic agents, in particular contrast media, in rats. In order to study the influence of osmolality and viscosity changes, the model mechanistically represents urine concentration by water re-absorption in different segments of kidney tubules and viscosity dependent tubular fluid flow.The model was established using experimental data on the physiological steady state without administration of any contrast media or drugs. These data included the sodium and urea concentration gradient along the cortico-medullary axis, water reabsorption, urine flow and sodium as well as urea urine concentrations for a normal hydration state. The model was evaluated by predicting the effects of mannitol and contrast media administration and comparing to experimental data on cortico-medullary concentration gradients, urine flow, urine viscosity, hydrostatic tubular pressures and single nephron glomerular filtration rate. Finally the model was used to analyze and compare typical examples of ionic and non-ionic monomeric as well as non-ionic dimeric contrast media with respect to their osmolality and viscosity. With the computational kidney model, urine flow depended mainly on osmolality, while osmolality and viscosity were important determinants for tubular hydrostatic pressure and kidney exposure. The low diuretic effect of dimeric contrast media in combination with their high intrinsic viscosity resulted in a high viscosity within the tubular fluid. In comparison to monomeric contrast media, this led to a higher increase in tubular pressure, to a reduction in glomerular filtration rate and tubular flow and to an increase in kidney exposure.The presented kidney model can be implemented into whole body physiologically-based pharmacokinetic models and extended in order to simulate the renal excretion of lipophilic drugs which may also undergo active secretion

  2. Kidney Transplant

    Science.gov (United States)

    ... of the tiny filters within your kidneys (glomeruli) Polycystic kidney disease People with end-stage renal disease need ... and kidney failure, but it is not a cure. Some forms of kidney disease may return after transplant. The health risks ...

  3. The iron cycle in chronic kidney disease (CKD): from genetics and experimental models to CKD patients

    Science.gov (United States)

    Zumbrennen-Bullough, Kimberly; Babitt, Jodie L.

    2014-01-01

    Iron is essential for most living organisms but iron excess can be toxic. Cellular and systemic iron balance is therefore tightly controlled. Iron homeostasis is dysregulated in chronic kidney disease (CKD) and contributes to the anemia that is prevalent in this patient population. Iron supplementation is one cornerstone of anemia management in CKD patients, but has not been rigorously studied in large prospective randomized controlled trials. This review highlights important advances from genetic studies and animal models that have provided key insights into the molecular mechanisms governing iron homeostasis and its disturbance in CKD, and summarizes how these findings may yield advances in the care of this patient population. PMID:24235084

  4. Basement membrane chondroitin sulfate proteoglycan alterations in a rat model of polycystic kidney disease

    DEFF Research Database (Denmark)

    Ehara, T; Carone, F A; McCarthy, K J

    1994-01-01

    Alterations in basement membrane components, notably proteoglycans, in a rat model of polycystic kidney disease have been investigated. Rats were fed phenol II (2-amino-4-hydroxyphenyl-5-phenyl thiazole) for 4 days and then changed to normal diet for a 7-day recovery period. Marked dilation...... membrane heparan sulfate proteoglycan core protein related to perlecan did not diminish but rather stained affected tubules intensely, whereas laminin, on the other hand, was apparently diminished in the basement membranes of the cystic tubules. Type IV collagen staining did not change through disease...... in this disease....

  5. Improved prediction of tacrolimus concentrations early after kidney transplantation using theory-based pharmacokinetic modelling

    Science.gov (United States)

    Størset, Elisabet; Holford, Nick; Hennig, Stefanie; Bergmann, Troels K; Bergan, Stein; Bremer, Sara; Åsberg, Anders; Midtvedt, Karsten; Staatz, Christine E

    2014-01-01

    Aims The aim was to develop a theory-based population pharmacokinetic model of tacrolimus in adult kidney transplant recipients and to externally evaluate this model and two previous empirical models. Methods Data were obtained from 242 patients with 3100 tacrolimus whole blood concentrations. External evaluation was performed by examining model predictive performance using Bayesian forecasting. Results Pharmacokinetic disposition parameters were estimated based on tacrolimus plasma concentrations, predicted from whole blood concentrations, haematocrit and literature values for tacrolimus binding to red blood cells. Disposition parameters were allometrically scaled to fat free mass. Tacrolimus whole blood clearance/bioavailability standardized to haematocrit of 45% and fat free mass of 60 kg was estimated to be 16.1 l h−1 [95% CI 12.6, 18.0 l h−1]. Tacrolimus clearance was 30% higher (95% CI 13, 46%) and bioavailability 18% lower (95% CI 2, 29%) in CYP3A5 expressers compared with non-expressers. An Emax model described decreasing tacrolimus bioavailability with increasing prednisolone dose. The theory-based model was superior to the empirical models during external evaluation displaying a median prediction error of −1.2% (95% CI −3.0, 0.1%). Based on simulation, Bayesian forecasting led to 65% (95% CI 62, 68%) of patients achieving a tacrolimus average steady-state concentration within a suggested acceptable range. Conclusion A theory-based population pharmacokinetic model was superior to two empirical models for prediction of tacrolimus concentrations and seemed suitable for Bayesian prediction of tacrolimus doses early after kidney transplantation. PMID:25279405

  6. Clinical risk assessment of patients with chronic kidney disease by using clinical data and multivariate models.

    Science.gov (United States)

    Chen, Zewei; Zhang, Xin; Zhang, Zhuoyong

    2016-12-01

    Timely risk assessment of chronic kidney disease (CKD) and proper community-based CKD monitoring are important to prevent patients with potential risk from further kidney injuries. As many symptoms are associated with the progressive development of CKD, evaluating risk of CKD through a set of clinical data of symptoms coupled with multivariate models can be considered as an available method for prevention of CKD and would be useful for community-based CKD monitoring. Three common used multivariate models, i.e., K-nearest neighbor (KNN), support vector machine (SVM), and soft independent modeling of class analogy (SIMCA), were used to evaluate risk of 386 patients based on a series of clinical data taken from UCI machine learning repository. Different types of composite data, in which proportional disturbances were added to simulate measurement deviations caused by environment and instrument noises, were also utilized to evaluate the feasibility and robustness of these models in risk assessment of CKD. For the original data set, three mentioned multivariate models can differentiate patients with CKD and non-CKD with the overall accuracies over 93 %. KNN and SVM have better performances than SIMCA has in this study. For the composite data set, SVM model has the best ability to tolerate noise disturbance and thus are more robust than the other two models. Using clinical data set on symptoms coupled with multivariate models has been proved to be feasible approach for assessment of patient with potential CKD risk. SVM model can be used as useful and robust tool in this study.

  7. On the population of remnant Fanaroff-Riley type II radio galaxies and implications for radio source dynamics

    Science.gov (United States)

    Godfrey, L. E. H.; Morganti, R.; Brienza, M.

    2017-10-01

    The purpose of this work is two-fold: (1) to quantify the occurrence of ultrasteep spectrum remnant Fanaroff-Riley type II (FRII) radio galaxies in a 74 MHz flux-limited sample, and (2) perform Monte Carlo simulations of the population of active and remnant FRII radio galaxies to confront models of remnant lobe evolution, and to provide guidance for further investigation of remnant radio galaxies. We find that fewer than 2 per cent of FRII radio galaxies with S74 MHz > 1.5 Jy are candidate ultrasteep spectrum remnants, where we define ultrasteep spectrum as α _74 MHz^1400 MHz > 1.2. Our Monte Carlo simulations demonstrate that models involving Sedov-like expansion in the remnant phase, resulting in rapid adiabatic energy losses, are consistent with this upper limit, and predict the existence of nearly twice as many remnants with normal (not ultrasteep) spectra in the observed frequency range as there are ultrasteep spectrum remnants. This model also predicts an ultrasteep remnant fraction approaching 10 per cent at redshifts z studies of the remnant population.

  8. Excisional wound healing is delayed in a murine model of chronic kidney disease.

    Directory of Open Access Journals (Sweden)

    Akhil K Seth

    Full Text Available BACKGROUND: Approximately 15% of the United States population suffers from chronic kidney disease (CKD, often demonstrating an associated impairment in wound healing. This study outlines the development of a surgical murine model of CKD in order to investigate the mechanisms underlying this impairment. METHODS: CKD was induced in mice by partial cauterization of one kidney cortex and contralateral nephrectomy, modifying a previously published technique. After a minimum of 6-weeks, splinted, dorsal excisional wounds were created to permit assessment of wound healing parameters. Wounds were harvested on postoperative days (POD 0, 3, 7, and 14 for histological, immunofluorescent, and quantitative PCR (qPCR. RESULTS: CKD mice exhibited deranged blood chemistry and hematology profiles, including profound uremia and anemia. Significant decreases in re-epithelialization and granulation tissue deposition rates were found in uremic mice wounds relative to controls. On immunofluorescent analysis, uremic mice demonstrated significant reductions in cellular proliferation (BrdU and angiogenesis (CD31, with a concurrent increase in inflammation (CD45 as compared to controls. CKD mice also displayed differential expression of wound healing-related genes (VEGF, IL-1β, eNOS, iNOS on qPCR. CONCLUSIONS: These findings represent the first reported investigation of cutaneous healing in a CKD animal model. Ongoing studies of this significantly delayed wound healing phenotype include the establishment of renal failure model in diabetic strains to study the combined effects of CKD and diabetes.

  9. Excisional Wound Healing Is Delayed in a Murine Model of Chronic Kidney Disease

    Science.gov (United States)

    Seth, Akhil K.; De la Garza, Mauricio; Fang, Robert C.; Hong, Seok J.; Galiano, Robert D.

    2013-01-01

    Background Approximately 15% of the United States population suffers from chronic kidney disease (CKD), often demonstrating an associated impairment in wound healing. This study outlines the development of a surgical murine model of CKD in order to investigate the mechanisms underlying this impairment. Methods CKD was induced in mice by partial cauterization of one kidney cortex and contralateral nephrectomy, modifying a previously published technique. After a minimum of 6-weeks, splinted, dorsal excisional wounds were created to permit assessment of wound healing parameters. Wounds were harvested on postoperative days (POD) 0, 3, 7, and 14 for histological, immunofluorescent, and quantitative PCR (qPCR). Results CKD mice exhibited deranged blood chemistry and hematology profiles, including profound uremia and anemia. Significant decreases in re-epithelialization and granulation tissue deposition rates were found in uremic mice wounds relative to controls. On immunofluorescent analysis, uremic mice demonstrated significant reductions in cellular proliferation (BrdU) and angiogenesis (CD31), with a concurrent increase in inflammation (CD45) as compared to controls. CKD mice also displayed differential expression of wound healing-related genes (VEGF, IL-1β, eNOS, iNOS) on qPCR. Conclusions These findings represent the first reported investigation of cutaneous healing in a CKD animal model. Ongoing studies of this significantly delayed wound healing phenotype include the establishment of renal failure model in diabetic strains to study the combined effects of CKD and diabetes. PMID:23536900

  10. Overexpression of exogenous kidney-specific Ngal attenuates progressive cyst development and prolongs lifespan in a murine model of polycystic kidney disease.

    Science.gov (United States)

    Wang, Ellian; Chiou, Yuan-Yow; Jeng, Wen-Yih; Lin, Hsiu-Kuan; Lin, Hsi-Hui; Chin, Hsian-Jean; Leo Wang, Chi-Kuang; Yu, Shang-Shiuan; Tsai, Shih-Chieh; Chiang, Chih-Ying; Cheng, Po-Hao; Lin, Hong-Jie; Jiang, Si-Tse; Chiu, Sou-Tyau; Hsieh-Li, Hsiu Mei

    2017-02-01

    Neutrophil gelatinase-associated lipocalin (Ngal) is a biomarker for acute and chronic renal injuries, including polycystic kidney disease (PKD). However, the effect of Ngal on PKD progression remains unexplored. To study this, we generated 3 strains of mice with different expression levels of Ngal within an established PKD model (Pkd1L3/L3): Pkd1L3/L3 (with endogenous Ngal), Pkd1L3/L3; NgalTg/Tg (with endogenous and overexpression of exogenous kidney-specific Ngal) and Pkd1L3/L3; Ngal-/- mice (with Ngal deficiency). Knockout of endogenous Ngal had no effect on phenotypes, cystic progression, or survival of the PKD mice. However, the transgenic mice had a significantly longer lifespan, smaller (but not fewer) renal cysts, and less interstitial fibrosis than the mice without or with endogenous Ngal. Western-blot analyses showed significant increases in Ngal and cleaved caspase-3 and decreases in α-smooth muscle actin, hypoxia-inducible factor 1-α, pro-caspase 3, proliferating cell nuclear antigen, Akt, mammalian target of rapamycin, and S6 Kinase in the transgenic mice as compared with the other 2 strains of PKD mice. Thus, overexpression of exogenous kidney-specific Ngal reduced cystic progression and prolonged the lifespan in PKD mice, was associated with reductions in interstitial fibrosis and proliferation, and augmented apoptosis. Copyright © 2016 International Society of Nephrology. Published by Elsevier Inc. All rights reserved.

  11. Review: An Australian model of care for co-morbid diabetes and chronic kidney disease.

    Science.gov (United States)

    Lo, Clement; Zimbudzi, Edward; Teede, Helena; Cass, Alan; Fulcher, Greg; Gallagher, Martin; Kerr, Peter G; Jan, Stephen; Johnson, Greg; Mathew, Tim; Polkinghorne, Kevan; Russell, Grant; Usherwood, Tim; Walker, Rowan; Zoungas, Sophia

    2018-02-05

    Diabetes and chronic kidney disease (CKD) are two of the most prevalent co-morbid chronic diseases in Australia. The increasing complexity of multi-morbidity, and current gaps in health-care delivery for people with co-morbid diabetes and CKD, emphasise the need for better models of care for this population. Previously, proposed published models of care for co-morbid diabetes and CKD have not been co-designed with stake-holders or formally evaluated. Particular components of health-care shown to be effective in this population are interventions that: are structured, intensive and multifaceted (treating diabetes and multiple cardiovascular risk factors); involve multiple medical disciplines; improve self-management by the patient; and upskill primary health-care. Here we present an integrated patient-centred model of health-care delivery incorporating these components and co-designed with key stake-holders including specialist health professionals, general practitioners and Diabetes and Kidney Health Australia. The development of the model of care was informed by focus groups of patients and health-professionals; and semi-structured interviews of care-givers and health professionals. Other distinctives of this model of care are routine screening for psychological morbidity; patient-support through a phone advice line; and focused primary health-care support in the management of diabetes and CKD. Additionally, the model of care integrates with the patient-centred health-care home currently being rolled out by the Australian Department of Health. This model of care will be evaluated after implementation across two tertiary health services and their primary care catchment areas. Copyright © 2018 John Wiley & Sons, Ltd. This article is protected by copyright. All rights reserved.

  12. Laparoscopic total remnant pancreatectomy after laparoscopic pancreaticoduodenectomy.

    Science.gov (United States)

    Sunagawa, Hiroki; Mayama, Yasuaki; Orokawa, Tomofumi; Oshiro, Naoto

    2014-01-01

    Total remnant pancreatectomy after pancreaticoduodenectomy (PD) is a difficult procedure. Recently, distal pancreatectomy and PD have been performed laparoscopically. Herein, we present the first case report of a laparoscopic total remnant pancreatectomy. A 72-year-old woman underwent a totally laparoscopic pylorus-preserving PD for inferior bile duct cancer. The tumor was composed of moderately differentiated tubular adenocarcinoma and was diagnosed as pStage III according to the UICC-TNM classification. Eighteen months later, CT showed a low-density mass in the remnant pancreas. We conducted a total resection of the remnant pancreas laparoscopically. Histologically, it was diagnosed as a primary pancreatic cancer. The patient's postoperative course was uneventful. She was discharged on postoperative day 14. When an initial PD is performed laparoscopically, laparoscopic total remnant pancreatectomy is technically feasible and safe in selected patients. © 2014 Japan Society for Endoscopic Surgery, Asia Endosurgery Task Force and Wiley Publishing Asia Pty Ltd.

  13. Fluid transport and ion fluxes in mammalian kidney proximal tubule: a model analysis of isotonic transport

    DEFF Research Database (Denmark)

    Larsen, Erik Hviid; Møbjerg, N.; Sørensen, J. N.

    2006-01-01

    'blocking' of apical water channels and in 'aquaporin-null' simulation. Reduced rate of volume reabsorption in AQP(-/-) mice would also require decreased apical sodium permeability. Paracellular convection accounts for approx. 36% of the net Na+ absorption, and the model epithelium accomplishes uphill water...... simulates major physiological features of proximal tubule, including significantly lower water permeability of the AQP1-null preparation, and a ratio of net sodium uptake and oxygen consumption exceeding that predicted from stoichiometry of the Na+/K+-pump. Physical properties of interspace basement......Aim: By mathematical modelling, we analyse conditions for near-isotonic and isotonic transport by mammalian kidney proximal tubule. Methods: The model comprises compliant lateral intercellular space (lis) and cells, and infinitely large luminal and peritubular compartments with diffusible species...

  14. Fluid transport and ion fluxes in mammalian kidney proximal tubule: a model analysis of isotonic transport

    DEFF Research Database (Denmark)

    Larsen, E.H.; Møbjerg, N.; Sørensen, Jens Nørkær

    2006-01-01

    'blocking' of apical water channels and in 'aquaporin-null' simulation. Reduced rate of volume reabsorption in AQP(-/-) mice would also require decreased apical sodium permeability. Paracellular convection accounts for approx. 36% of the net Na+ absorption, and the model epithelium accomplishes uphill water...... simulates major physiological features of proximal tubule, including significantly lower water permeability of the AQP1-null preparation, and a ratio of net sodium uptake and oxygen consumption exceeding that predicted from stoichiometry of the Na+/K+-pump. Physical properties of interspace basement......Aim: By mathematical modelling, we analyse conditions for near-isotonic and isotonic transport by mammalian kidney proximal tubule. Methods: The model comprises compliant lateral intercellular space (lis) and cells, and infinitely large luminal and peritubular compartments with diffusible species...

  15. Kidney fibroblast growth factor 23 does not contribute to elevation of its circulating levels in uremia

    DEFF Research Database (Denmark)

    Mace, Maria L.; Gravesen, Eva; Nordholm, Anders

    2017-01-01

    plasma levels of FGF23 in uremia. FGF23 mRNA was not detected in normal kidneys, but was clearly demonstrated in injured kidneys, already after four hours in obstructive nephropathy and at 8 weeks in the remnant kidney of 5/6 nephrectomized rats. No renal extraction was found in uremic rats in contrast...... to normal rats. Removal of the remnant kidney had no effect on plasma FGF23 levels. Well-known regulators of FGF23 expression in bone, such as parathyroid hormone, calcitriol, and inhibition of the FGF receptor by PD173074, had no impact on kidney expression of FGF23. Thus, the only direct contribution...

  16. Comparison of trichostatin A and valproic acid treatment regimens in a mouse model of kidney fibrosis

    Energy Technology Data Exchange (ETDEWEB)

    Van Beneden, Katrien, E-mail: kvbenede@vub.ac.be [Department of Human Anatomy, Liver Cell Biology Lab, Vrije Universiteit Brussel, Brussels (Belgium); Geers, Caroline [Department of Pathology, Universitair Ziekenhuis Brussel, Brussels (Belgium); Pauwels, Marina [Department of Human Anatomy, Liver Cell Biology Lab, Vrije Universiteit Brussel, Brussels (Belgium); Mannaerts, Inge [Department of Cell Biology, Liver Cell Biology Lab, Vrije Universiteit Brussel, Brussels (Belgium); Wissing, Karl M. [Department of Nephrology, Universitair Ziekenhuis Brussel, Brussels (Belgium); Van den Branden, Christiane [Department of Human Anatomy, Liver Cell Biology Lab, Vrije Universiteit Brussel, Brussels (Belgium); Grunsven, Leo A. van, E-mail: lvgrunsv@vub.ac.be [Department of Cell Biology, Liver Cell Biology Lab, Vrije Universiteit Brussel, Brussels (Belgium)

    2013-09-01

    Histone deacetylase (HDAC) inhibitors are promising new compounds for the therapy of fibrotic diseases. In this study we compared the effect of two HDAC inhibitors, trichostatin A and valproic acid, in an experimental model of kidney fibrosis. In mice, doxorubicin (adriamycin) can cause nephropathy characterized by chronic proteinuria, glomerular damage and interstitial inflammation and fibrosis, as seen in human focal segmental glomerulosclerosis. Two treatment regimens were applied, treatment was either started prior to the doxorubicin insult or delayed until a significant degree of proteinuria and fibrosis was present. Pre-treatment of trichostatin A significantly hampered glomerulosclerosis and tubulointerstitial fibrosis, as did the pre-treatment with valproic acid. In contrast, the development of proteinuria was only completely inhibited in the pre-treated valproic acid group, and not in the pre-treated trichostatin A animals. In the postponed treatment with valproic acid, a complete resolution of established doxorubicin-induced proteinuria was achieved within three days, whereas trichostatin A could not correct proteinuria in such a treatment regimen. However, both postponed regimens have comparable efficacy in maintaining the kidney fibrosis to the level reached at the start of the treatments. Moreover, not only the process of fibrosis, but also renal inflammation was attenuated by both HDAC inhibitors. Our data confirm a role for HDACs in renal fibrogenesis and point towards a therapeutic potential for HDAC inhibitors. The effect on renal disease progression and manifestation can however be different for individual HDAC inhibitors. - Highlights: • Valproic acid is a potent antiproteinuric drug, whereas trichostatin A is not. • Trichostatin A and valproic acid reduce kidney fibrosis in doxorubicin nephropathy. • Both valproic acid and trichostatin A attenuate renal inflammation.

  17. Experimental model for acute kidney injury caused by uropathogenic Escherichia coli

    Directory of Open Access Journals (Sweden)

    Beata Skowron

    2017-06-01

    Full Text Available Introduction: Acute kidney injury (AKI is the rapid deterioration of renal function, diagnosed on the basis of an increase in serum creatinine and abnormal urinary parameters. AKI is associated with increased risk of mortality or chronic kidney disease (CKD.The aim of the study was to develop an experimental model for AKI resulting from Escherichia coli-induced pyelonephritis. E. coli was isolated from a patient with clinical symptoms of urinary tract infection (UTI.Material/Methods: The study included three groups of female Wistar rats (groups 1, 2 and 3, in which pyelonephritis was induced by transurethral inoculation with highly virulent E. coli (105, 107 and 109 cfu/ml, respectively. Urine and blood samples for analysis were obtained prior to the inoculation (day 0, as well as 7, 14 and 21 days thereafter.Results: Aside from a microbiological examination of urine samples, daily urine output, serum creatinine (CreaS, creatinine clearance (CrCl, interleukin 6 (IL-6, fractional excretion of sodium (FENa and fractional excretion of urea (FEUrea were determined. A histopathological examination of kidney and urinary bladder specimens was conducted as well. While UTI-related pyelonephritis developed irrespective of E. coli inoculum size, AKI was observed only following transurethral administration of E. coli at the intermediate and high dose, i.e. 107 and 109 cfu/ml, respectively (group 2 and 3. Discussion: An increase in CreaS and abnormal diuresis were accompanied by changes in parameters specific for various forms of AKI, i.e. FENa and FEUrea. Based on these changes, administration of E. coli at 107 cfu/ml was demonstrated to induce renal AKI, whereas inoculation with 109 cfu/ml seemed to cause not only ascending pyelonephritis, but perhaps also bacteremia and urosepsis (prerenal component of AKI.

  18. Inhibiting the HSP90 chaperone slows cyst growth in a mouse model of autosomal dominant polycystic kidney disease.

    Science.gov (United States)

    Seeger-Nukpezah, Tamina; Proia, David A; Egleston, Brian L; Nikonova, Anna S; Kent, Tatiana; Cai, Kathy Q; Hensley, Harvey H; Ying, Weiwen; Chimmanamada, Dinesh; Serebriiskii, Ilya G; Golemis, Erica A

    2013-07-30

    Autosomal dominant polycystic kidney disease (ADPKD) is a progressive genetic syndrome with an incidence of 1:500 in the population, arising from inherited mutations in the genes for polycystic kidney disease 1 (PKD1) or polycystic kidney disease 2 (PKD2). Typical onset is in middle age, with gradual replacement of renal tissue with thousands of fluid-filled cysts, resulting in end-stage renal disease requiring dialysis or kidney transplantation. There currently are no approved therapies to slow or cure ADPKD. Mutations in the PKD1 and PKD2 genes abnormally activate multiple signaling proteins and pathways regulating cell proliferation, many of which we observe, through network construction, to be regulated by heat shock protein 90 (HSP90). Inhibiting HSP90 with a small molecule, STA-2842, induces the degradation of many ADPKD-relevant HSP90 client proteins in Pkd1(-/-) primary kidney cells and in vivo. Using a conditional Cre-mediated mouse model to inactivate Pkd1 in vivo, we find that weekly administration of STA-2842 over 10 wk significantly reduces initial formation of renal cysts and kidney growth and slows the progression of these phenotypes in mice with preexisting cysts. These improved disease phenotypes are accompanied by improved indicators of kidney function and reduced expression and activity of HSP90 clients and their effectors, with the degree of inhibition correlating with cystic expansion in individual animals. Pharmacokinetic analysis indicates that HSP90 is overexpressed and HSP90 inhibitors are selectively retained in cystic versus normal kidney tissue, analogous to the situation observed in solid tumors. These results provide an initial justification for evaluating HSP90 inhibitors as therapeutic agents for ADPKD.

  19. A nurse-coordinated model of care versus usual care for chronic kidney disease: meta-analysis.

    Science.gov (United States)

    Xu, Haidan; Mou, Lisha; Cai, Zhiming

    2017-06-01

    To investigate whether a nurse-led care was more beneficial for implementing chronic kidney disease guidelines and improved multiple risk factors compared with the usual care. Several independent clinical trials have been carried out to demonstrate the efficiency of a nurse-led care to improve the outcomes for patients with chronic kidney disease and address the risk factors for renal function decline. However, their results and conclusions were inconsistent. A meta-analysis was carried out on September 2015 based on previous studies that evaluated the efficiency of nurse-led care model for patients with chronic kidney disease. Following quality appraisal, four randomised clinical trials that allocated patients with chronic kidney disease to usual care and nurse-coordinated care were included. Primary outcomes, such as kidney failure and cardiovascular events, were analysed. Compared with the usual care group, a nurse-coordinated care model reduced the risks of composite death, decreased the occurrence rate of end-stage renal disease and doubled serum creatinine. On the contrary, a slight propulsive effect of nurse-led interventional care occurred on acute myocardial infarction and heart failure. Only five studies were included and conducted nonstandard evaluating endpoints, causing fewer studies were categorised in each outcome events in this meta-analysis, subsequently leading to heterogeneity and less persuasive. Intensive interventions delivered by nurse coordinators are expected to benefit patients to attain longer life expectancy and higher life quality as well as to improve controlling risk factors implicated in chronic kidney disease progression. More government and hospitals should modify the traditional nursing routine based on this study, providing a more intensive nurse-coaching care model for patients with chronic kidney disease, even aged or other chronic diseases, which shall further help to better control the risk factors and delay disease

  20. The Oak Ridge Polycystic Kidney mouse: modeling ciliopathies of mice and men.

    Energy Technology Data Exchange (ETDEWEB)

    Lehman, J M [University of Alabama, Birmingham; Michaud III, Edward J [ORNL; Schoeb, T [University of Alabama, Birmingham; Aydin Son, Yesim [University of Tennessee, Knoxville (UTK); Miller, M [University of Alabama, Birmingham; Yoder, Bradley [University of Alabama, Birmingham

    2008-08-01

    The Oak Ridge Polycystic Kidney (ORPK) mouse was described nearly 14 years ago as a model for human recessive polycystic kidney disease. The ORPK mouse arose through integration of a transgene into an intron of the Ift88 gene resulting in a hypomorphic allele (Ift88Tg737Rpw). The Ift88Tg737Rpw mutation impairs intraflagellar transport (IFT), a process required for assembly of motile and immotile cilia. Historically, the primary immotile cilium was thought to have minimal importance for human health; however, a rapidly expanding number of human disorders have now been attributed to ciliary defects. Importantly, many of these phenotypes are present and can be analyzed using the ORPK mouse. In this review, we highlight the research conducted using the OPRK mouse and the phenotypes shared with human cilia disorders. Furthermore, we describe an additional follicular dysplasia phenotype in the ORPK mouse, which alongside the ectodermal dysplasias seen in human Ellis-van Creveld and Sensenbrenner's syndromes, suggests an unappreciated role for primary cilia in the skin and hair follicle.

  1. l-Carnitine improves cognitive and renal functions in a rat model of chronic kidney disease.

    Science.gov (United States)

    Abu Ahmad, Nur; Armaly, Zaher; Berman, Sylvia; Jabour, Adel; Aga-Mizrachi, Shlomit; Mosenego-Ornan, Efrat; Avital, Avi

    2016-10-01

    Over the past decade, the prevalence of chronic kidney disease (CKD) has reached epidemic proportions. The search for novel pharmacological treatment for CKD has become an area of intensive clinical research. l-Carnitine, considered as the "gatekeeper" responsible for admitting long chain fatty acids into cell mitochondria. l-Carnitine synthesis and turnover are regulated mainly by the kidney and its levels inversely correlate with serum creatinine of normal subjects and CKD patients. Previous studies showed that l-carnitine administration to elderly people is improving and preserving cognitive function. As yet, there are no clinical intervention studies that investigated the effect of l-carnitine administration on cognitive impairment evidenced in CKD patients. Thus, we aimed to investigate the effects of l-carnitine treatment on renal function and on the cognitive performance in a rat model of progressive CKD. To assess the role of l-carnitine on CKD condition, we estimated the renal function and cognitive abilities in a CKD rat model. We found that all CKD animals exhibited renal function deterioration, as indicated by elevated serum creatinine, BUN, and ample histopathological abnormalities. l-Carnitine treatment of CKD rats significantly reduced serum creatinine and BUN, attenuated renal hypertrophy and decreased renal tissue damage. In addition, in the two way shuttle avoidance learning, CKD animals showed cognitive impairment which recovered by the administration of l-carnitine. We conclude that in a rat model of CKD, l-carnitine administration significantly improved cognitive and renal functions. Copyright © 2016 Elsevier Inc. All rights reserved.

  2. Development of predisposition, injury, response, organ failure model for predicting acute kidney injury in acute on chronic liver failure.

    Science.gov (United States)

    Maiwall, Rakhi; Sarin, Shiv Kumar; Kumar, Suman; Jain, Priyanka; Kumar, Guresh; Bhadoria, Ajeet Singh; Moreau, Richard; Kedarisetty, Chandan Kumar; Abbas, Zaigham; Amarapurkar, Deepak; Bhardwaj, Ankit; Bihari, Chhagan; Butt, Amna Subhan; Chan, Albert; Chawla, Yogesh Kumar; Chowdhury, Ashok; Dhiman, RadhaKrishan; Dokmeci, Abdul Kadir; Ghazinyan, Hasmik; Hamid, Saeed Sadiq; Kim, Dong Joon; Komolmit, Piyawat; Lau, George K; Lee, Guan Huei; Lesmana, Laurentius A; Jamwal, Kapil; Mamun-Al-Mahtab; Mathur, Rajendra Prasad; Nayak, Suman Lata; Ning, Qin; Pamecha, Viniyendra; Alcantara-Payawal, Diana; Rastogi, Archana; Rahman, Salimur; Rela, Mohamed; Saraswat, Vivek A; Shah, Samir; Shiha, Gamal; Sharma, Barjesh Chander; Sharma, Manoj Kumar; Sharma, Kapil; Tan, Soek Siam; Chandel, Shivendra Singh; Vashishtha, Chitranshu; Wani, Zeeshan A; Yuen, Man-Fung; Yokosuka, Osamu; Duseja, Ajay; Jafri, Wasim; Devarbhavi, Harshad; Eapen, C E; Goel, Ashish; Sood, Ajit; Ji, Jia; Duan, Z; Chen, Y

    2017-10-01

    There is limited data on predictors of acute kidney injury in acute on chronic liver failure. We developed a PIRO model (Predisposition, Injury, Response, Organ failure) for predicting acute kidney injury in a multicentric cohort of acute on chronic liver failure patients. Data of 2360 patients from APASL-ACLF Research Consortium (AARC) was analysed. Multivariate logistic regression model (PIRO score) was developed from a derivation cohort (n=1363) which was validated in another prospective multicentric cohort of acute on chronic liver failure patients (n=997). Factors significant for P component were serum creatinine[(≥2 mg/dL)OR 4.52, 95% CI (3.67-5.30)], bilirubin [(failure (OR-3.5, 95% CI 2.2-5.5). The PIRO score predicted acute kidney injury with C-index of 0.95 and 0.96 in the derivation and validation cohort. The increasing PIRO score was also associated with mortality (Pfailure patients at risk of developing acute kidney injury. It reliably predicts mortality in these patients, underscoring the prognostic significance of acute kidney injury in patients with acute on chronic liver failure. © 2017 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  3. Kidney Diseases

    Science.gov (United States)

    ... urine until you go to the bathroom. Most kidney diseases attack the nephrons. This damage may leave kidneys ... or medicines. You have a higher risk of kidney disease if you have diabetes, high blood pressure, or ...

  4. Ulinastatin Protects against Acute Kidney Injury in Infant Piglets Model Undergoing Surgery on Hypothermic Low-Flow Cardiopulmonary Bypass

    Science.gov (United States)

    Wang, Xiaocou; Xue, Qinghua; Yan, Fuxia; Liu, Jinping; Li, Shoujun; Hu, Shengshou

    2015-01-01

    Objective Infants are more vulnerable to kidney injuries induced by inflammatory response syndrome and ischemia-reperfusion injury following cardiopulmonary bypass especially with prolonged hypothermic low-flow (HLF). This study aims to evaluate the protective role of ulinastatin, an anti-inflammatory agent, against acute kidney injuries in infant piglets model undergoing surgery on HLF cardiopulmonary bypass. Methods Eighteen general-type infant piglets were randomly separated into the ulinastatin group (Group U, n = 6), the control group (Group C, n = 6), and the sham operation group (Group S, n = 6), and anaesthetized. The groups U and C received following experimental procedure: median thoracotomy, routine CPB and HLF, and finally weaned from CPB. The group S only underwent sham median thoracotomy. Ulinastatin at a dose of 5,000 units/kg body weight and a certain volume of saline were administrated to animals of the groups U and C at the beginning of CPB and at aortic declamping, respectively. Venous blood samples were collected at 3 different time points: after anesthesia induction in all experimental groups, 5 minutes, and 120 minutes after CPB in the Groups U and C. Markers for inflammation and acute kidney injury were tested in the collected plasma. N-acetyl-β-D-glucosaminidase (NAG) from urine, markers of oxidative stress injury and TUNEL-positive cells in kidney tissues were also detected. Results The expressions of plasma inflammatory markers and acute kidney injury markers increased both in Group U and Group C at 5 min and 120 min after CPB. Also, numbers of TUNEL-positive cells and oxidative stress markers in kidney rose in both groups. At the time point of 120-min after CPB, compared with the Group C, some plasma inflammatory and acute kidney injury markers as well as TUNEL-positive cells and oxidative stress markers in kidney were significantly reduced in the Group U. Histologic analyses showed that HLF promoted acute tubular necrosis and dilatation

  5. Examining the Protective Role of Caraway Hydroalcoholic Extract in Heart and Kidney Tissue Injury in CLP Rat Model

    Directory of Open Access Journals (Sweden)

    A Dadkhah

    2012-05-01

    Full Text Available

    Background and Objectives: Sepsis is a systemic response to infection leading to organdeath.With regard to the side effects of synthetic drugs, nowadays using medicinal plants in treatment of sepsis must not be ignored. In this study, the protective role of caraway hydroalcoholic extractin heart and kidney injuries in experimental inflammation model induced by cecal ligation and puncture (CLP was examined.

     

    Methods: For the purpose of this study, the rats were divided into five groups i.e: Sham-operated (SOP; CLP; CLP+hydroalcoholic extract (50&100 mg/kg and CLP+Indomethacin (10mg/kg as positive control. The extract and indomethacin were injected i.p immediately after sepsis induction. 24 hours after CLP, the rats were sacrificed and their hearts, kidneys and plasma were removed and analyzed. The differences between the results were assessed by one-way ANOVA test followed byTukey’s HSD.

     

    Results: The results of this study showed that lipid peroxidation (LP in kidney and alsoplasmaurea/creatinine ratio were increased in CLP rats. In contrast, the glutathione (GSH level of kidney was not changed indicating the partial damage of kidney tissue due to sepsis. Unlike indomethacine, treatment of rats with both doses of caraway hydroalcoholic extract did not modulate these parameters.

     

    Conclusion: It can be concluded that treatment of septic rats by caraway hydroalcoholic extract immediately after sepsis induction via i.p route cannot modulate parameters related to kidney damages.So, this extract is not able to protect the kidney tissue against oxidative injuries induced by sepsis.

     

  6. A model-specific role of microRNA-223 as a mediator of kidney injury during experimental sepsis.

    Science.gov (United States)

    Colbert, James F; Ford, Joshay A; Haeger, Sarah M; Yang, Yimu; Dailey, Kyrie L; Allison, Kristen C; Neudecker, Viola; Evans, Christopher M; Richardson, Vanessa L; Brodsky, Kelley S; Faubel, Sarah; Eltzschig, Holger K; Schmidt, Eric P; Ginde, Adit A

    2017-08-01

    Sepsis outcomes are heavily dependent on the development of septic organ injury, but no interventions exist to interrupt or reverse this process. microRNA-223 (miR-223) is known to be involved in both inflammatory gene regulation and host-pathogen interactions key to the pathogenesis of sepsis. The goal of this study was to determine the role of miR-223 as a mediator of septic kidney injury. Using miR-223 knockout mice and multiple models of experimental sepsis, we found that miR-223 differentially influences acute kidney injury (AKI) based on the model used. In the absence of miR-223, mice demonstrated exaggerated AKI in sterile models of sepsis (LPS injection) and attenuated AKI in a live-infection model of sepsis (cecal ligation and puncture). We demonstrated that miR-223 expression is induced in kidney homogenate after cecal ligation and puncture, but not after LPS or fecal slurry injection. We investigated additional potential mechanistic explanations including differences in peritoneal bacterial clearance and host stool virulence. Our findings highlight the complex role of miR-223 in the pathogenesis of septic kidney injury, as well as the importance of differences in experimental sepsis models and their consequent translational applicability. Copyright © 2017 the American Physiological Society.

  7. Reverse epidemiology, obesity and mortality in chronic kidney disease: modelling mortality expectations using energetics.

    Science.gov (United States)

    Speakman, John R; Westerterp, Klaas R

    2010-01-01

    Obesity is a predisposing factor for chronic illnesses such as type 2 diabetes, heart disease and cancer. In chronic kidney disease (CKD), the effect of obesity on mortality is reversed. Obese patients appear protected. Two ideas have been advanced to explain this 'reverse epidemiology'. First, obesity may buffer patients from wasting. Second, fat may sequester uraemic toxins leading to a systematic error in the prescription of dialysis. Our aim was to use data on the scaling of daily energy expenditure, fat and lean tissue mass to predict the pattern of variation in mortality with obesity under the contrasting hypotheses. We used data on daily energy demands measured using the doubly labelled water technique and body composition collected on a cohort of 503 individuals to model the expected impacts of wasting and fat sequestration/underdialysis on mortality. A model predicting mortality due to wasting replicated the mortality pattern of the obesity paradox. However, quantitatively the beneficial effect of being fat was predicted to be much larger than that observed in the actual CKD population. Similar results were found for the fat sequestration/underdialysis hypothesis, but in this case the discrepancy was smaller. These models tend to support the fat sequestration and underdialysis idea more than the wasting hypothesis. In part (or in whole) this may be because of inadequacies in the model construction which are currently based on rather crude assumptions. Refinement of the models may enable better tests between alternative ideas for the obesity paradox. Copyright (c) 2010 S. Karger AG, Basel.

  8. Numerical code for fitting radial emission profile of a shell supernova remnant: Application

    Directory of Open Access Journals (Sweden)

    Opsenica Slobodan

    2011-01-01

    Full Text Available We present IDL (Interactive Data Language codes for fitting a theoretical emission profile of a shell supernova remnant (SNR to the mean profile of an SNR obtained from radio observations. Two considered theoretical models are: 1 a shell with constant emissivity and 2 a synchrotron shell with radially aligned magnetic field. The codes were applied to several observed supernova remnants. Good results are obtained in five considered cases, which justify the use of our code for remnants that are bright (so that observational errors are not large and spherically symmetric enough.

  9. Acute and chronic kidney disease in elderly patients with hip fracture: prevalence, risk factors and outcome with development and validation of a risk prediction model for acute kidney injury.

    Science.gov (United States)

    Porter, Christine J; Moppett, Iain K; Juurlink, Irene; Nightingale, Jessica; Moran, Christopher G; Devonald, Mark A J

    2017-01-14

    Hip fracture is a common injury in older people with a high rate of postoperative morbidity and mortality. This patient group is also at high risk of acute kidney injury (AKI) and chronic kidney disease (CKD), but little is known of the impact of kidney disease on outcome following hip fracture. An observational cohort of consecutive patients with hip fracture in a large UK secondary care hospital. Predictive modelling of outcomes using development and validation datasets. Inclusion: all patients admitted with hip fracture with sufficient serum creatinine measurements to define acute kidney injury. Main outcome measures - development of acute kidney injury during admission; mortality (in hospital, 30-365 day and to follow-up); length of hospital stay. Data were available for 2848 / 2959 consecutive admissions from 2007-2011; 776 (27.2%) male. Acute kidney injury occurs in 24%; development of acute kidney injury is independently associated with male sex (OR 1.48 (1.21 to 1.80), premorbid chronic kidney disease stage 3B or worse (OR 1.52 (1.19 to 1.93)), age (OR 3.4 (2.29 to 5.2) for >85 years) and greater than one major co-morbidities (OR 1.61 (1.34 to 1.93)). Acute kidney injury of any stage is associated with an increased hazard of death, and increased length of stay (Acute kidney injury: 19.1 (IQR 13 to 31) days; no acute kidney injury 15 (11 to 23) days). A simplified predictive model containing Age, CKD stage (3B-5), two or more comorbidities, and male sex had an area under the ROC curve of 0.63 (0.60 to 0.67). Acute kidney injury following hip fracture is common and associated with worse outcome and greater hospital length of stay. With the number of people experiencing hip fracture predicted to rise, recognition of risk factors and optimal perioperative management of acute kidney injury will become even more important.

  10. Grinding Down Stars and Stellar Remnants Into Accretion Disks

    Science.gov (United States)

    Sadika Nasim, Syeda; Fabj, Gaia; McKernan, Barry; Ford, K. E. Saavik

    2018-01-01

    Active galactic nuclei (AGN) are powered by the accretion of matter onto supermassive black holes (SMBH). Most accretion models take the form of disks of gas around the SMBH. Stars and stellar remnants also orbit the SMBH. Orbiting objects plunging through the disk experience a drag force, and through repeated passage, orbiters can have their orbits ground-down into the plane of the disk. Using two different accretion disk models, TQM (Thompson, Quataert & Murray), and SG (Sirko & Goodman), we determine the grind-down time for stars and stellar remnants, as a function of initial inclination angle, and initial radius. Orbital grind-down time is important because stellar-mass black holes (sBH) within AGN disks are likely to merge at a higher rate than in the field. Accurate estimates of orbital grind-down time can help constrain predictions of the AGN channel for LIGO.

  11. Observational data on Galactic supernova remnants: II. The supernova remnants within l = 90°-270°

    Directory of Open Access Journals (Sweden)

    Guseinov O.H.

    2004-01-01

    Full Text Available We have collected all the available data on Galactic supernova remnants given in the literature. The data of Galactic supernova remnants located in the Galactic longitude interval l=90° - 270° in all spectral bands are represented in this work. We have adopted distance values for the SNRs by examining these data. The data of various types on neutron stars connected to these supernova remnants are also represented. Remarks of some authors and by ourselves regarding the data and some properties of both the supernova remnants and the point sources are given.

  12. Magnolia Extract (BL153 Ameliorates Kidney Damage in a High Fat Diet-Induced Obesity Mouse Model

    Directory of Open Access Journals (Sweden)

    Wenpeng Cui

    2013-01-01

    Full Text Available Accumulating evidence demonstrated that obesity is a risk factor for renal structural and functional changes, leading to the end-stage renal disease which imposes a heavy economic burden on the community. However, no effective therapeutic method for obesity-associated kidney disease is available. In the present study, we explored the therapeutic potential of a magnolia extract (BL153 for treating obesity-associated kidney damage in a high fat diet- (HFD- induced mouse model. The results showed that inflammation markers (tumor necrosis factor-α and plasminogen activator inhibitor-1 and oxidative stress markers (3-nitrotyrosine and 4-hydroxy-2-nonenal were all significantly increased in the kidney of HFD-fed mice compared to mice fed with a low fat diet (LFD. Additionally, proteinuria and renal structure changes in HFD-fed mice were much more severe than that in LFD-fed mice. However, all these alterations were attenuated by BL153 treatment, accompanied by upregulation of peroxisome proliferator-activated receptor-γ coactivator-1α (PGC-1α and hexokinase II (HK II expression in the kidney. The present study indicates that BL153 administration may be a novel approach for renoprotection in obese individuals by antiinflammation and anti-oxidative stress most likely via upregulation of PGC-1α and HK II signal in the kidney.

  13. Inducing Somatic Pkd1 Mutations in Vivo in a Mouse Model of Autosomal-Dominant Polycystic Kidney Disease

    Science.gov (United States)

    2016-10-01

    Autosomal Dominant Polycystic Kidney Disease (ADPKD) is one of the world’s most common life-threatening genetic diseases. Over 95% of diagnosed cases of... genetic models to induce mutations: one during embryogenesis (Six2-cre) and one in the adult (Villin-cre). The embryonic model has generated clones of...wildtype and mutant cells that persist in the adult. The adult model has failed to induce sufficient recombination . In this report we summarize the

  14. Bidirectional Relationship between Chronic Kidney Disease and Periodontal Disease: Structural Equation Modeling

    Science.gov (United States)

    Fisher, Monica A.; Taylor, George W.; West, Brady T.; McCarthy, Ellen T.

    2011-01-01

    Periodontal disease is associated with diabetes, heart disease, and chronic kidney disease (CKD), an effect postulated to be due in part to endovascular inflammation. While a bidirectional relationship between CKD and periodontal disease is plausible, it has not been previously reported in the literature. Over 11 200 adults 18 years or older were identified in the Third National Health and Nutrition Examination Survey. Analyses were conducted in two stages. First, multivariable logistic regression models were fitted to test the hypothesis that periodontal disease was independently associated with CKD. Given the potential that the periodontal disease and CKD relationship may be bidirectional, a two-step analytic approach was used that involved 1) tests for mediation, and 2) structural equation models to examine more complex direct and indirect effects of periodontal disease on CKD, and vice versa. In two separate models periodontal disease (ORAdj =1.62 (95% CI: 1.17-2.26) and edentulism (ORAdj = 1.83 (1.31-2.55) and periodontal disease score (ORAdj = 1.01 (1.01-1.02) were associated with CKD, when simultaneously adjusting for 14 other factors. Three of four structural equation models were most plausible suggesting bidirectional relationships. Collectively, these analyses provide for the first time empirical support for a bidirectional relationship between CKD and periodontal disease, and mediation of that relationship by diabetes duration and hypertension. PMID:20927035

  15. Supernova remnants across the Hubble sequence

    Science.gov (United States)

    Chomiuk, Laura Beth

    Supernova remnants (SNRs) are thought to be the primary sites of cosmic ray acceleration in galaxies, and in this thesis we investigate how the properties of radio SNRs---and the physics of particle acceleration---depend on their parent galaxies. We combine new data with results compiled from the literature to investigate the radio continuum luminosity function of SNRs in 22 nearby galaxies, ranging from dwarf irregulars to luminous starbursts. We find that the luminosity functions can all be modeled with a power law of constant index, and an amplitude which depends on a combination of galaxy star formation rate and interstellar medium (ISM) density. These results can be fit with a simple cartoon model where the magnetic fields in SNRs are significantly amplified above ambient ISM values and the efficiency of cosmic ray acceleration is constant across galaxies. The luminosity of a galaxy's brightest SNR scales with star formation rate, and we find that the Milky Way falls on the measured correlation if we assume a star formation rate of 2 M⊙ yr--1 (synthesized from the literature) and that Cassiopeia A is the most luminous SNR in our Galaxy. As a first step in expanding studies of SNRs to non-star-forming galaxies, we also describe our discovery of an SNR candidate in a globular cluster around the gas-poor S0 galaxy NGC 7457.

  16. Nonthermal Radiation from Supernova Remnant Shocks

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    Hyesung Kang

    2013-09-01

    Full Text Available Most of high energy cosmic rays (CRs are thought to be produced by diffusive shock acceleration (DSA at supernova remnants (SNRs within the Galaxy. Fortunately, nonthermal emissions from CR protons and electrons can provide direct observational evidence for such a model and place strong constraints on the complex nonlinear plasma processes in DSA theory. In this study we calculate the energy spectra of CR protons and electrons in Type Ia SNRs, using time-dependent DSA simulations that incorporate phenomenological models for some wave-particle interactions. We demonstrate that the timedependent evolution of the self-amplified magnetic fields, Alfvénic drift, and escape of the highest energy particles affect the energy spectra of accelerated protons and electrons, and so resulting nonthermal radiation spectrum. Especially, the spectral cutoffs in X-ray and γ-ray emission spectra are regulated by the evolution of the highest energy particles, which are injected at the early phase of SNRs. Thus detailed understandings of nonlinear wave-particle interactions and time-dependent DSA simulations of SNRs are crucial in testing the SNR hypothesis for the origin of Galactic cosmic rays.

  17. Total renal denervation reduces sympathoexcitation to different target organs in a model of chronic kidney disease.

    Science.gov (United States)

    Veiga, Glaucia L; Nishi, Erika E; Estrela, Heder F; Lincevicius, Gisele S; Gomes, Guiomar N; Simões Sato, Alex Y; Campos, Ruy R; Bergamaschi, Cássia T

    2017-05-01

    It is known that increased sympathetic nerve activity in chronic kidney disease (CKD) progressively worsens kidney function and hypertension. We tested the hypothesis that total renal denervation contributes to reduce sympathetic activation to different beds and improves renal function in 5/6 nephrectomy model of CKD in male Wistar rats. After eight weeks of 5/6 nephrectomy surgery there was an increase in mean arterial pressure (CKD 179±22mmHg, n=6 vs. control animals 108±9; pkidney, splanchnic and lumbar beds compared to control (CTL) group (CKD rSNA: 150±50, n=9 vs. CTL 96±15, n=9; CKD sSNA: 129±51, n=5 vs. CTL 34±14, n=6; CKD lSNA: 203±35, n=8 vs. CTL 146±21, spikes/s, n=7, p<0.05). Three weeks after total renal denervation (DNX) MAP was normalized in the CKD rats (124±19mmHg, n=5, p<0.05), with no change in HR. The lSNA was normalized (151±40, n=5, vs. CKD 203±35 spikes/s, n=8) and sSNA was decreased in 49% (64±34, n=5 vs. CKD 129±51 spikes/s, n=5, p<0.05). Renal function, assessed by creatinine plasma levels was improved after renal denervation (CKD 1.50±0.64, n=8; vs. CKD+DNX 0.82±0.22mg/mL, n=8, p<0.05). These findings demonstrate that renal nerves contribute to the maintenance of hypertension in CKD by increasing sympathoexcitation to other beds. Copyright © 2016 Elsevier B.V. All rights reserved.

  18. Polycystic kidney rat is a novel animal model of Caroli's disease associated with congenital hepatic fibrosis.

    Science.gov (United States)

    Sanzen, T; Harada, K; Yasoshima, M; Kawamura, Y; Ishibashi, M; Nakanuma, Y

    2001-05-01

    Caroli's disease (congenital intrahepatic biliary dilatation) associated with congenital hepatic fibrosis is an autosomal recessive polycystic kidney disease. Recently, the polycystic kidney (PCK) rat, a spontaneous mutant derived from a colony of CRJ:CD rats with polycystic lesions in the liver and an autosomal recessive mode of inheritance, was reported. In the present study, the pathology of the hepatobiliary system and the biliary cell-kinetics were evaluated in fetuses (day 18 to 21 of gestation) and neonates and adults (1 day to 4 months after delivery) of PCK rats. CRJ:CD rats were used as a control. Multiple segmental and saccular dilatations of intrahepatic bile ducts were first observed in fetuses at 19 days of gestation. The dilatation spread throughout the liver and the degree of dilatation increased with aging. Gross and histological features characterizing ductal plate malformation were common in the intrahepatic bile ducts. Overgrowth of portal connective tissue was evident and progressive after delivery. These features were very similar to those of Caroli's disease with congenital hepatic fibrosis. Proliferative activity in the biliary epithelial cells was greater in PCK rats than controls during the development. In contrast, the biliary epithelial apoptosis was less extensive in PCK rats than the controls until 1 week after delivery, but greater after 3 weeks, suggesting that the remodeling defect in immature bile ducts associated with the imbalance of cell kinetics plays a role in the occurrence of intrahepatic biliary anomalies in PCK rats. The PCK rat could be a useful and promising animal model of Caroli's disease with congenital hepatic fibrosis.

  19. Hydrodynamic Simulations of Kepler's Supernova Remnant

    Science.gov (United States)

    Sullivan, Jessica; Blondin, John; Borkowski, Kazik; Reynolds, Stephen

    2018-01-01

    Kepler’s supernova remnant contains unusual features that strongly suggest an origin in a single-degenerate Type Ia explosion, including anisotropic circumstellar medium (CSM), a strong brightness gradient, and spatially varying expansion proper motions. We present 3Dhydrodynamic simulations to test a picture in which Kepler's progenitor binary emitted a strong asymmetric wind, densest in the orbital plane, while the system moved at high velocity through the ISM. We simulate the creation of the presupernova environment as well as the supernova blast wave, using the VH-1 grid-based hydrodynamics code. We first modeled an anisotropic wind to create an asymmetric bowshock around the progenitor, then the blast wave from thesupernova. The final simulation places both previous model pieces onto a single grid and allows the blast wave to expand into the bowshock. Models were completed on a Yin-Yang grids with matching angular resolutions. By manipulating parameters that control the asymmetry of the system, we attempted to find conditions that recreated the current state of Kepler. We analyzed these models by comparing images of Kepler from the Chandra X-ray Observatory to line-of-sight projections from the model results. We also present comparisons of simulated expansion velocities with recent observations of X-ray proper motions from Chandra images. We were able to produce models that contained similar features to those seen in Kepler. We find the greatest resemblance to Kepler images with a presupernova wind with an equator-to-pole density contrast of 3 and a moderately disk-like CSM at a 5° angle between equatorial plane and system motion.

  20. Premalignant Lesions in the Kidney

    Directory of Open Access Journals (Sweden)

    Ziva Kirkali

    2001-01-01

    Full Text Available Renal cell carcinoma (RCC is the most malignant urologic disease. Different lesions, such as dysplasia in the tubules adjacent to RCC, atypical hyperplasia in the cyst epithelium of von Hippel-Lindau syndrome, and adenoma have been described for a number of years as possible premalignant changes or precursor lesions of RCC. In two recent papers, kidneys adjacent to RCC or removed from other causes were analyzed, and dysplastic lesions were identified and defined in detail. Currently renal intraepithelial neoplasia (RIN is the proposed term for classification. The criteria for a lesion to be defined as premalignant are (1 morphological similarity; (2 spatial association; (3 development of microinvasive carcinoma; (4 higher frequency, severity, and extent then invasive carcinoma; (5 progression to invasive cancer; and (6 similar genetic alterations. RIN resembles the neoplastic cells of RCC. There is spatial association. Progression to invasive carcinoma is described in experimental cancer models, and in some human renal tumors. Similar molecular alterations are found in some putative premalignant changes. The treatment for RCC is radical or partial nephrectomy. Preneoplastic lesions may remain in the renal remnant in patients treated by partial nephrectomy and may be the source of local recurrences. RIN seems to be a biologic precursor of some RCCs and warrants further investigation. Interpretation and reporting of these lesions would reveal important resources for the biological nature and clinical significance. The management of RIN diagnosed in a renal biopsy and partial nephrectomy needs to be answered.

  1. Influence of the Roof Movement Control Method on the Stability of Remnant

    Science.gov (United States)

    Adach-Pawelus, Karolina

    2017-12-01

    In the underground mines, there are geological and mining situations that necessitate leaving behind remnants in the mining field. Remnants, in the form of small, irregular parcels, are usually separated in the case of: significant problems with maintaining roof stability, high rockburst hazard, the occurrence of complex geological conditions and for random reasons (ore remnants), as well as for economic reasons (undisturbed rock remnants). Remnants left in the mining field become sites of high stress values concentration and may affect the rock in their vicinity. The values of stress inside the remnant and its vicinity, as well as the stability of the remnant, largely depend on the roof movement control method used in the mining field. The article presents the results of the numerical analysis of the influence of roof movement control method on remnant stability and the geomechanical situation in the mining field. The numerical analysis was conducted for the geological and mining conditions characteristic of Polish underground copper mines owned by KGHM Polska Miedz S.A. Numerical simulations were performed in a plane strain state by means of Phase 2 v. 8.0 software, based on the finite element method. The behaviour of remnant and rock mass in its vicinity was simulated in the subsequent steps of the room and pillar mining system for three types of roof movement control method: roof deflection, dry backfill and hydraulic backfill. The parameters of the rock mass accepted for numerical modelling were calculated by means of RocLab software on the basis of the Hoek-Brown classification. The Mohr-Coulomb strength criterion was applied.

  2. Newly Developed Rat Model of Chronic Kidney Disease-Mineral Bone Disorder.

    Science.gov (United States)

    Watanabe, Kentaro; Fujii, Hideki; Goto, Shunsuke; Nakai, Kentaro; Kono, Keiji; Watanabe, Shuhei; Shinohara, Masami; Nishi, Shinichi

    2018-02-01

    Chronic kidney disease-mineral bone disorder (CKD-MBD) is associated with all-cause and cardiovascular morbidity and mortality in patients with CKD. Thus, elucidating its pathophysiological mechanisms is essential for improving the prognosis. We evaluated characteristics of CKD-MBD in a newly developed CKD rat model. We used male Sprague-Dawley (SD) rats and spontaneously diabetic Torii (SDT) rats, which are used as models for nonobese type 2 diabetes. CKD was induced by 5/6 nephrectomy (Nx). At 10 weeks, the rats were classified into six groups and administered with a vehicle or a low- or high-dose paricalcitol thrice a week. At 20 weeks, the rats were sacrificed; blood and urinary biochemical analyses and histological analysis of the aorta were performed. At 20 weeks, hemoglobin A1c (HbA1c) levels, blood pressure, and renal function were not significantly different among the six groups. Serum calcium and phosphate levels tended to be higher in SDT-Nx rats than in SD-Nx rats. The urinary excretion of calcium and phosphate was significantly greater in SDT-Nx rats than in SD-Nx rats. After administering paricalcitol, serum parathyroid hormone (PTH) and fibroblast growth factor 23 (FGF23) levels were significantly higher in SDT-Nx rats than in SD-Nx rats. The degree of aortic calcification was significantly more severe and the aortic calcium content was significantly greater in SDT-Nx rats than in SD-Nx rats. We suggest that our new CKD rat model using SDT rats represents a useful CKD-MBD model, and this model was greatly influenced by paricalcitol administration. Further studies are needed to clarify the detailed mechanisms underlying this model.

  3. Radio emission from embryonic superluminous supernova remnants

    Science.gov (United States)

    Omand, Conor M. B.; Kashiyama, Kazumi; Murase, Kohta

    2018-02-01

    It has been widely argued that Type-I superluminous supernovae (SLSNe-I) are driven by powerful central engines with a long-lasting energy injection after the core-collapse of massive progenitors. One of the popular hypotheses is that the hidden engines are fast-rotating pulsars with a magnetic field of B ˜ 1013-1015 G. Murase, Kashiyama & Mészáros proposed that quasi-steady radio/submm emission from non-thermal electron-positron pairs in nascent pulsar wind nebulae can be used as a relevant counterpart of such pulsar-driven supernovae (SNe). In this work, focusing on the nascent SLSN-I remnants, we examine constraints that can be placed by radio emission. We show that the Atacama Large Millimeter/submillimetre Array can detect the radio nebula from SNe at DL ˜ 1 Gpc in a few years after the explosion, while the Jansky Very Large Array can also detect the counterpart in a few decades. The proposed radio follow-up observation could solve the parameter degeneracy in the pulsar-driven SN model for optical/UV light curves, and could also give us clues to young neutron star scenarios for SLSNe-I and fast radio bursts.

  4. The Masses of Supernova Remnant Progenitors

    Science.gov (United States)

    Williams, Benjamin

    2012-10-01

    One of the key constraints on the production of supernovae {SNe} is the initial mass of the stars that eventually end in these cataclysmic events. Historically it has been very difficult to obtain estimates of the masses of SN progenitors because there have only been a few dozen nearby events, only a handful of which have high-quality precursor imaging.We propose dramatically increasing the number of SNe with progenitor mass estimates by applying an exciting new technique to HST archival data in M31 and M33. Through detailed modeling of the stellar populations surrounding the location of any known SNe, we can constrain the progenitor mass. Since supernova remnants {SNRs} mark the locations of SNe for the past 20,000 years and M31 and M33 contain hundreds of these objects, detailed studies of the stellar populations at these locations will constrain the progenitor masses of potentially hundreds of events. After correlating archival HST imaging with the SNR positions, there is useful data for 137 SNRs. We have already measured the progenitor masses for 65 SNRs in M31 and plan to apply our method to 72 SNRs in M33. This proposal will fund the publication of our M31 measurements, analysis of the M33 SNRs, and public release of our photometry. Ultimately, our work will increase the existing sample of SN progenitor masses in the literature by a factor of 20.

  5. Quantum remnants in the classical limit

    Energy Technology Data Exchange (ETDEWEB)

    Kowalski, A.M., E-mail: kowalski@fisica.unlp.edu.ar [Instituto de Física (IFLP-CCT-Conicet), Universidad Nacional de La Plata, C.C. 727, 1900 La Plata (Argentina); Comision de Investigaciones Científicas (CIC) (Argentina); Plastino, A., E-mail: plastino@fisica.unlp.edu.ar [Instituto de Física (IFLP-CCT-Conicet), Universidad Nacional de La Plata, C.C. 727, 1900 La Plata (Argentina); Argentina' s National Research Council (CONICET) (Argentina); SThAR, EPFL Innovation Park, Lausanne (Switzerland)

    2016-09-16

    We analyze here the common features of two dynamical regimes: a quantum and a classical one. We deal with a well known semi-classic system in its route towards the classical limit, together with its purely classic counterpart. We wish to ascertain i) whether some quantum remnants can be found in the classical limit and ii) the details of the quantum-classic transition. The so-called mutual information is the appropriate quantifier for this task. Additionally, we study the Bandt–Pompe's symbolic patterns that characterize dynamical time series (representative of the semi-classical system under scrutiny) in their evolution towards the classical limit. - Highlights: • We investigate the classical limit (CL) of a well known semi classical model. • The study is made by reference to the Bandt Pompe symbolic approach. • The number and type of associated symbols changes as one proceeds towards the CL. • We ascertain which symbols pertaining to the quantum zone remain in the CL.

  6. A New Murine Model of Chronic Kidney Disease-Mineral and Bone Disorder

    Directory of Open Access Journals (Sweden)

    Bianca Frauscher

    2017-01-01

    Full Text Available Chronic kidney disease (CKD is associated with mineral and bone disorder (MBD, which is the main cause of the extensively increased cardiovascular mortality in the CKD population. We now aimed to establish a new murine experimental CKD-MBD model. Dilute brown non-Agouti (DBA/2 mice were fed with high-phosphate diet for 4 (HPD4 or 7 (HPD7 days, then with standard chow diet (SCD and subsequently followed until day 84. They were compared to DBA/2 mice maintained on SCD during the whole study period. Both 4 and 7 days HPD-fed mice developed phosphate nephropathy with tubular atrophy, interstitial fibrosis, decreased glomerular filtration rate, and increased serum urea levels. The abdominal aorta of HPD-treated mice showed signs of media calcification. Histomorphometric analysis of HPD-treated mice showed decreased bone volume/tissue volume, low mineral apposition rate, and low bone formation rate as compared to SCD-fed mice, despite increased parathyroid hormone levels. Overall, the observed phenotype was more pronounced in the HPD7 group. In summary, we established a new, noninvasive, and therefore easy to perform reproducible CKD-MBD model, which showed media calcification, secondary hyperparathyroidism, and low-turnover bone disease.

  7. A predictive model of progressive chronic kidney disease in idiopathic nephrotic syndrome.

    Science.gov (United States)

    Mendonça, Ana Carmen Quaresma; Oliveira, Eduardo Araújo; Fróes, Brunna Pinto; Faria, Lauro Damasceno Carvalho; Pinto, Juliana Silva; Nogueira, Maira Melo Ibrahim; Lima, Gabriella Oliveira; Resende, Priscila Isa; Assis, Natália Silva; Simões E Silva, Ana Cristina; Pinheiro, Sérgio Veloso Brant

    2015-11-01

    There are limited data on the risk factors for chronic kidney disease (CKD) in children with idiopathic nephrotic syndrome (INS). This retrospective cohort study aimed to develop a predictive model for CKD progression in children with INS. Between 1970 and 2012, a total of 294 patients with INS were followed up. The primary outcome was progression to CKD stage 3 or higher. A predictive model was developed using a Cox proportional hazards model. A score was calculated using b-coefficients and summing up points assigned to each significant variable. Prognostic score was grouped into categories: low risk, medium risk, and high risk. Median follow-up was 6.9 years. Median renal survival was 26.1 years and probability of CKD stage 3 or higher was 8% in 10 years. Multivariate analysis showed that the most accurate model included initial age, hematuria, and steroid resistance. Accuracy was high with a c-statistic of 0.95 (95% confidence interval [CI] 0.91-0.99), 0.92 (95% CI 0.88-0.96), and 0.92 (95% CI 0.87-0.97) at 2, 5, and 10 years of follow-up respectively. By survival analysis, 10-year renal survival was 100% for the low-risk and 95% for the medium-risk group, while 40% of high-risk patients would exhibit CKD stage 3 or higher (P predictive model of CKD may contribute to the early identification of a subgroup of INS patients at a high risk of renal dysfunction.

  8. Severity of sepsis-induced acute kidney injury in a novel mouse model is age dependent.

    Science.gov (United States)

    Maddens, Bert; Vandendriessche, Benjamin; Demon, Dieter; Vanholder, Raymond; Chiers, Koen; Cauwels, Anje; Meyer, Evelyne

    2012-09-01

    Despite extensive research, the mortality rate of patients with sepsis-induced acute kidney injury (AKI) is unacceptably high, especially in the elderly. Current sepsis models have difficulties in reproducing AKI. This study aimed to develop a novel, clinically relevant mouse model for sepsis-induced AKI by uterine ligation and inoculation of bacteria. In addition, the age dependency of the severity of sepsis and sepsis-induced AKI was studied by validating this model in three different age categories. Experimental animal investigation. University research laboratory. Young (12-14 wks), aged (46-48 wks), and old (70-72 wks) C57BL/6 female mice were used as models for adolescent, adult premenopausal, and elderly postmenopausal women, respectively. Uterine ligation and inoculation with 10 colony forming unit Escherichia coli or saline (sham) was performed; in vivo imaging with a luminescent Escherichia coli strain documented the course of infection. All mice had established Escherichia coli sepsis at 48 hrs postinfection, with higher mortality rate in old (43%) compared to aged (23%) or young (9%) mice. Infected mice had elevated serum or plasma cytokine, chemokine (tumor necrosis factor, interleukin-6, keratinocyte-derived chemokine, monocyte chemoattractant protein 1, and interleukin-10), and NOx concentrations compared to sham mice. AKI was confirmed by renal histology. Serum creatinine concentrations at 48 hrs increased with age (mean ± SEM; controls 0.18 ± 0.03 mg/dL, young 0.28 ± 0.03 mg/dL, aged 0.38 ± 0.05 mg/dL, and old 0.44 ± 0.06 mg/dL). The uterine ligation and inoculation model for sepsis-induced AKI starts from a real infectious focus and shows an age-dependent severity of septic AKI that resembles AKI in humans.

  9. Remnant for all black objects due to gravity's rainbow

    Energy Technology Data Exchange (ETDEWEB)

    Ali, Ahmed Farag, E-mail: afarag@zewailcity.edu.eg [Department of Physics, Florida State University, Tallahassee, FL 32306 (United States); Center for Fundamental Physics, Zewail City of Science and Technology, Giza 12588 (Egypt); Department of Physics, Faculty of Science, Benha University, Benha 13518 (Egypt); Faizal, Mir, E-mail: f2mir@uwaterloo.ca [Department of Physics and Astronomy, University of Waterloo, Waterloo, Ontario, N2L 3G1 (Canada); Khalil, Mohammed M., E-mail: moh.m.khalil@gmail.com [Department of Electrical Engineering, Alexandria University, Alexandria 12544 (Egypt)

    2015-05-15

    We argue that a remnant is formed for all black objects in gravity's rainbow. This will be based on the observation that a remnant depends critically on the structure of the rainbow functions, and this dependence is a model independent phenomena. We thus propose general relations for the modified temperature and entropy of all black objects in gravity's rainbow. We explicitly check this to be the case for Kerr, Kerr–Newman-dS, charged-AdS, and higher dimensional Kerr–AdS black holes. We also try to argue that a remnant should form for black saturn in gravity's rainbow. This work extends our previous results on remnants of Schwarzschild black holes and black rings.

  10. [Acute kidney injury after pediatric cardiac surgery: risk factors and outcomes. Proposal for a predictive model].

    Science.gov (United States)

    Cardoso, Bárbara; Laranjo, Sérgio; Gomes, Inês; Freitas, Isabel; Trigo, Conceição; Fragata, Isabel; Fragata, José; Pinto, Fátima

    2016-02-01

    To characterize the epidemiology and risk factors for acute kidney injury (AKI) after pediatric cardiac surgery in our center, to determine its association with poor short-term outcomes, and to develop a logistic regression model that will predict the risk of AKI for the study population. This single-center, retrospective study included consecutive pediatric patients with congenital heart disease who underwent cardiac surgery between January 2010 and December 2012. Exclusion criteria were a history of renal disease, dialysis or renal transplantation. Of the 325 patients included, median age three years (1 day-18 years), AKI occurred in 40 (12.3%) on the first postoperative day. Overall mortality was 13 (4%), nine of whom were in the AKI group. AKI was significantly associated with length of intensive care unit stay, length of mechanical ventilation and in-hospital death (p<0.01). Patients' age and postoperative serum creatinine, blood urea nitrogen and lactate levels were included in the logistic regression model as predictor variables. The model accurately predicted AKI in this population, with a maximum combined sensitivity of 82.1% and specificity of 75.4%. AKI is common and is associated with poor short-term outcomes in this setting. Younger age and higher postoperative serum creatinine, blood urea nitrogen and lactate levels were powerful predictors of renal injury in this population. The proposed model could be a useful tool for risk stratification of these patients. Copyright © 2015 Sociedade Portuguesa de Cardiologia. Published by Elsevier España. All rights reserved.

  11. Time Evolution of Gamma Rays from Supernova Remnants

    Science.gov (United States)

    Gaggero, Daniele; Zandanel, Fabio; Cristofari, Pierre; Gabici, Stefano

    2018-01-01

    We present a systematic phenomenological study focused on the time evolution of the non-thermal radiation - from radio waves to gamma rays - emitted by typical supernova remnants via hadronic and leptonic mechanisms, for two classes of progenitors: thermonuclear and core-collapse. To this aim, we develop a numerical tool designed to model the evolution of the cosmic-ray spectrum inside a supernova remnant, and compute the associated multi-wavelength emission. We demonstrate the potential of this tool in the context of future population studies based on large collection of high-energy gamma-ray data. We discuss and explore the relevant parameter space involved in the problem, and focus in particular on their impact on the maximum energy of accelerated particles, in order to study the effectiveness and duration of the PeVatron phase. We outline the crucial role of the ambient medium through which the shock propagates during the remnant evolution. In particular, we point out the role of dense clumps in creating a significant hardening in the hadronic gamma-ray spectrum.

  12. The First Reported Infrared Emission from the SN1006 Remnant

    Science.gov (United States)

    Winkler, P. Frank; Williams, Brian J.; Blair, William P.; Borkowski, Kazimierz J.; Ghavamian, Parviz; Long, Knox S.; Raymond, John C.; Reynolds, Stephen P.

    2012-01-01

    We report results of infrared imaging and spectroscopic observations of the SN 1006 remnant, carried out with the Spitzer Space Telescope. The 24 m image from MIPS clearly shows faint filamentary emission along the northwest rim of the remnant shell, nearly coincident with the Balmer filaments that delineate the present position of the expanding shock. The 24 m emission traces the Balmer filaments almost perfectly, but lies a few arcsec within, indicating an origin in interstellar dust heated by the shock. Subsequent decline in the IR behind the shock is presumably due largely to grain destruction through sputtering. The emission drops far more rapidly than current models predict, however, even for a higher proportion of small grains than would be found closer to the Galactic plane. The rapid drop may result in part from a grain density that has always been lowera relic effect from an earlier epoch when the shock was encountering a lower densitybut higher grain destruction rates still seem to be required. Spectra from three positions along the NW filament from the IRS instrument all show only a featureless continuum, consistent with thermal emission from warm dust. The dust-to-gas mass ratio in the pre-shock interstellar medium is lower than that expected for the Galactic ISM-as has also been observed in the analysis of IR emission from other SNRs but whose cause remains unclear. As with other SNIa remnants, SN1006 shows no evidence for dust grain formation in the supernova ejecta.

  13. Blood Pressure Lowering and Safety Improvements With Liver Angiotensinogen Inhibition in Models of Hypertension and Kidney Injury.

    Science.gov (United States)

    Mullick, Adam E; Yeh, Steve T; Graham, Mark J; Engelhardt, Jeffery A; Prakash, Thazha P; Crooke, Rosanne M

    2017-09-01

    Uncontrolled hypertension is an important contributor to cardiovascular disease. Despite the armamentarium of antihypertensive treatments, there remains a need for novel agents effective in individuals who cannot reach acceptable blood pressure levels. Inhibitors targeting the renin-angiotensin-aldosterone system (RAAS) are widely used but may not optimally inhibit RAAS and demonstrate an acceptable safety profile. Experiments were conducted to characterize a series of AGT (angiotensinogen) antisense oligonucleotides (ASOs) and compare their efficacy and tolerability to traditional RAAS blockade. AGT ASOs which target multiple systemic sites of AGT versus an N-acetylgalactosamine-conjugated AGT ASO that targets the liver were compared with captopril and losartan. Spontaneously hypertensive rats fed an 8% NaCl diet, a model of malignant hypertension resistant to standard RAAS inhibitors, demonstrated robust and durable blood pressure reductions with AGT ASO treatments, which was not observed with standard RAAS blockade. Studies in rat models of acute kidney injury produced by salt deprivation revealed kidney injury with ASO treatment that reduced kidney-expressed AGT, but not in animals treated with the N-acetylgalactosamine AGT ASO despite comparable plasma AGT reductions. Administration of either captopril or losartan also produced acute kidney injury during salt deprivation. Thus, intrarenal RAAS derived from kidney AGT, and inhibited by the standard of care, contributes to the maintenance of renal function during severe RAAS challenge. Such improvements in efficacy and tolerability by a liver-selective AGT inhibitor could be desirable in individuals not at their blood pressure goal with existing RAAS blockade. © 2017 American Heart Association, Inc.

  14. Dance into the fire: dust survival inside supernova remnants

    Science.gov (United States)

    Micelotta, Elisabetta R.; Dwek, Eli; Slavin, Jonathan D.

    2016-06-01

    Core collapse supernovae (CCSNe) are important sources of interstellar dust, potentially capable of producing 1 M_{⊙}) of dust in their explosively expelled ejecta. However, unlike other dust sources, the dust has to survive the passage of the reverse shock, generated by the interaction of the supernova blast wave with its surrounding medium. Knowledge of the net amount of dust produced by CCSNe is crucial for understanding the origin and evolution of dust in the local and high-redshift universe. Our goal is to identify the dust destruction mechanisms in the ejecta, and derive the net amount of dust that survives the passage of the reverse shock. To do so, we have developed analytical models for the evolution of a supernova blast wave and of the reverse shock, and the simultaneous processing of the dust inside the cavity of the supernova remnant. We have applied our models to the special case of the clumpy ejecta of the remnant of Cassiopeia A (Cas A), assuming that the dust (silicates and carbon grains) resides in cool oxygen-rich ejecta clumps which are uniformly distributed within the remnant and surrounded by a hot X-ray emitting plasma (smooth ejecta). The passage of the reverse shock through the clumps gives rise to a relative gas-grain motion and also destroys the clumps. While residing in the ejecta clouds, dust is processed via kinetic sputtering, which is terminated either when the grains escape the clumps, or when the clumps are destroyed by the reverse shock. In either case, grain destruction proceeds thereafter by thermal sputtering in the hot shocked smooth ejecta. We find that 12 and 16 percent of silicate and carbon dust, respectively, survive the passage of the reverse shock by the time the shock has reached the center of the remnant. These fractions depend on the morphology of the ejecta and the medium into which the remnant is expanding, as well as the composition and size distribution of the grains that formed in the ejecta. Results will

  15. Endothelial STAT3 Modulates Protective Mechanisms in a Mouse Ischemia-Reperfusion Model of Acute Kidney Injury

    Directory of Open Access Journals (Sweden)

    Shataakshi Dube

    2017-01-01

    Full Text Available STAT3 is a transcriptional regulator that plays an important role in coordinating inflammation and immunity. In addition, there is a growing appreciation of the role STAT3 signaling plays in response to organ injury following diverse insults. Acute kidney injury (AKI from ischemia-reperfusion injury is a common clinical entity with devastating consequences, and the recognition that endothelial alterations contribute to kidney dysfunction in this setting is of growing interest. Consequently, we used a mouse with a genetic deletion of Stat3 restricted to the endothelium to examine the role of STAT3 signaling in the pathophysiology of ischemic AKI. In a mouse model of ischemic AKI, the loss of endothelial STAT3 signaling significantly exacerbated kidney dysfunction, morphologic injury, and proximal tubular oxidative stress. The increased severity of ischemic AKI was associated with more robust endothelial-leukocyte adhesion and increased tissue accumulation of F4/80+ macrophages. Moreover, important proximal tubular adaptive mechanisms to injury were diminished in association with decreased tissue mRNA levels of the epithelial cell survival cytokine IL-22. In aggregate, these findings suggest that the endothelial STAT3 signaling plays an important role in limiting kidney dysfunction in ischemic AKI and that selective pharmacologic activation of endothelial STAT3 signaling could serve as a potential therapeutic target.

  16. Model experiment of in vivo synchrotron X-ray diffraction of human kidney stones

    Energy Technology Data Exchange (ETDEWEB)

    Ancharov, A.I. [Institute of Solid State Chemistry and Mechanochemistry SB RAS, Novosibirsk (Russian Federation)]. E-mail: ancharov@mail.ru; Potapov, S.S. [Institute of Mineralogy UB RAS, Miass (Russian Federation); Moiseenko, T.N. [The State Regional Clinical Hospital, Novosibirsk (Russian Federation); Feofilov, I.V. [The State Regional Clinical Hospital, Novosibirsk (Russian Federation); Nizovskii, A.I. [Boreskov Institute of Catalysis SB RAS, Novosibirsk (Russian Federation)

    2007-05-21

    The diffraction of synchrotron radiation (SR) was used to explore the phase composition of kidney stones placed into a specific object phantom, which imitated the human body. As an imitation of the patient breath, the kidney stone was moved vertically and rotated to an angle of 15{sup o} during the recording of the X-ray pattern. It was shown that rotation and displacement did not distort the X-ray pattern.

  17. Optical cryo-imaging of kidney mitochondrial redox state in diabetic mice models

    Science.gov (United States)

    Maleki, S.; Sepehr, R.; Staniszewski, K.; Sheibani, N.; Sorenson, C. M.; Ranji, M.

    2012-03-01

    Oxidative stress (OS), which increases during diabetes, exacerbates the development and progression of diabetes complications including renal vascular and proximal tubule cell dysfunction. The objective of this study was to investigate the changes in the metabolic state of the tissue in diabetic mice kidneys using fluorescence imaging. Mitochondrial metabolic coenzymes NADH (Nicotinamide Adenine Dinucleotide), and FADH-2 (Flavin Adenine Dinucleotide) are autofluorescent and can be monitored without exogenous labels by optical techniques. The ratio of the fluorescence intensity of these fluorophores, (NADH/FAD), called the NADH redox ratio (RR), is a marker of metabolic state of a tissue. We examined mitochondrial redox states of kidneys from diabetic mice, Akita/+ and its control wild type (WT) for a group of 8- and 12-week-old mice. Average intensity and histogram of maximum projected images of FAD, NADH, and NADH RR were calculated for each kidney. Our results indicated a 17% decrease in the mean NADH RR of the kidney from 8-week-old mice compared with WT mice and, a 30% decrease in the mean NADH RR of kidney from12-week-old mice compared with WT mice. These results indicated an increase in OS in diabetic animals and its progression over time. Thus, NADH RR can be used as a hallmark of OS in diabetic kidney allowing temporal identification of oxidative state.

  18. Minocycline Attenuates Kidney Injury in a Rat Model of Streptozotocin-Induced Diabetic Nephropathy.

    Science.gov (United States)

    Yuan, Hongping; Zhang, Xiaoxuan; Zheng, Wei; Zhou, Hui; Zhang, Bo-Yin; Zhao, Dongxu

    2016-01-01

    The effects of minocycline on the development of diabetic nephropathy (DN) in streptozotocin (STZ) induced diabetic rats were evaluated in this study. The diabetes rats with DN were induced by STZ (55 mg/kg) injection. The experiment included 5 groups 1) normal, 2) normal plus minocycline for 16 weeks, 3) DN plus vehicle, 4) DN plus minocycline 16 weeks and 5) DN plus minocycline for 8 weeks. The pathological changes were analyzed by hematoxylin and eosin (H&E) staining and the apoptotic cells were stained by terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate nick-end labeling (TUNEL) staining. The mRNA expression of caspase-3, Bax and Bcl-2 in the kidney tissues was detected by quantitative RT-PCR. The biochemical parameters of blood and urine were determined by biochemical analyzer. Treatment with minocycline reduced the urine volume, 24-h urine protein, serum creatinine (Scr), blood urea nitrogen (BUN) but not blood alanine aminotransferase (ALT) in the DN rats. Furthermore, treatment with minocycline improved the pathological score of STZ-injured kidney and reduced the numbers of apoptotic cells in the kidney of DN rats. Moreover, minocycline mitigated the expression of caspase-3 and Bax mRNA, but increased Bcl-2 expression in the kidney of DN rats. These data indicated that minocycline improved the STZ-induced kidney damages, at least partially by protection form long-term hyperglycemia-induced kidney cell apoptosis.

  19. Effectiveness of management models for facilitating self-management and patient outcomes in adults with diabetes and chronic kidney disease.

    Science.gov (United States)

    Zimbudzi, Edward; Lo, Clement; Misso, Marie; Ranasinha, Sanjeeva; Zoungas, Sophia

    2015-06-10

    Self-management models can be a very powerful resource in the health system provided they are well tailored to a particular disease and setting. Patient outcomes have been demonstrated to improve when self-management practices are embedded in the care of people with certain diseases. However, it remains unclear whether self-management models and specific components of these programmes can be implemented in order to effectively improve the care of people with diabetes and/or chronic kidney disease. Medline (including Medline in-process), Excerpta medica database (EMBASE), Cumulative Index to Nursing and Allied Health (CINAHL) and all evidence-based medicine (EBM) will be systematically searched for randomised controlled studies comparing self-management models with usual care in patients with diabetes or chronic kidney disease. Two reviewers will independently assess articles for eligibility: extract data, evaluate risk of bias and complete quality assessment of included studies. The data will be tabulated and narratively synthesised. Meta-analyses will be performed if there is sufficient homogenous data. This protocol utilises rigorous methodology as well as pre-specified eligibility criteria to comprehensively search for diabetes and kidney disease self-management models which have been compared with usual care in randomised controlled trials. The review is likely to provide insight into the effectiveness of current models for improving patient self-management, and this may address the key translational issue of how to integrate and tailor these self-management practices for patients with diabetes and chronic kidney disease. PROSPERO CRD42015017316.

  20. Classification Models to Predict Survival of Kidney Transplant Recipients Using Two Intelligent Techniques of Data Mining and Logistic Regression.

    Science.gov (United States)

    Nematollahi, M; Akbari, R; Nikeghbalian, S; Salehnasab, C

    2017-01-01

    Kidney transplantation is the treatment of choice for patients with end-stage renal disease (ESRD). Prediction of the transplant survival is of paramount importance. The objective of this study was to develop a model for predicting survival in kidney transplant recipients. In a cross-sectional study, 717 patients with ESRD admitted to Nemazee Hospital during 2008-2012 for renal transplantation were studied and the transplant survival was predicted for 5 years. The multilayer perceptron of artificial neural networks (MLP-ANN), logistic regression (LR), Support Vector Machine (SVM), and evaluation tools were used to verify the determinant models of the predictions and determine the independent predictors. The accuracy, area under curve (AUC), sensitivity, and specificity of SVM, MLP-ANN, and LR models were 90.4%, 86.5%, 98.2%, and 49.6%; 85.9%, 76.9%, 97.3%, and 26.1%; and 84.7%, 77.4%, 97.5%, and 17.4%, respectively. Meanwhile, the independent predictors were discharge time creatinine level, recipient age, donor age, donor blood group, cause of ESRD, recipient hypertension after transplantation, and duration of dialysis before transplantation. SVM and MLP-ANN models could efficiently be used for determining survival prediction in kidney transplant recipients.

  1. Immunosuppressive therapy for kidney transplantation in adults: a systematic review and economic model.

    Science.gov (United States)

    Jones-Hughes, Tracey; Snowsill, Tristan; Haasova, Marcela; Coelho, Helen; Crathorne, Louise; Cooper, Chris; Mujica-Mota, Ruben; Peters, Jaime; Varley-Campbell, Jo; Huxley, Nicola; Moore, Jason; Allwood, Matt; Lowe, Jenny; Hyde, Chris; Hoyle, Martin; Bond, Mary; Anderson, Rob

    2016-08-01

    End-stage renal disease is a long-term irreversible decline in kidney function requiring renal replacement therapy: kidney transplantation, haemodialysis or peritoneal dialysis. The preferred option is kidney transplantation, followed by immunosuppressive therapy (induction and maintenance therapy) to reduce the risk of kidney rejection and prolong graft survival. To review and update the evidence for the clinical effectiveness and cost-effectiveness of basiliximab (BAS) (Simulect(®), Novartis Pharmaceuticals UK Ltd) and rabbit anti-human thymocyte immunoglobulin (rATG) (Thymoglobulin(®), Sanofi) as induction therapy, and immediate-release tacrolimus (TAC) (Adoport(®), Sandoz; Capexion(®), Mylan; Modigraf(®), Astellas Pharma; Perixis(®), Accord Healthcare; Prograf(®), Astellas Pharma; Tacni(®), Teva; Vivadex(®), Dexcel Pharma), prolonged-release tacrolimus (Advagraf(®) Astellas Pharma), belatacept (BEL) (Nulojix(®), Bristol-Myers Squibb), mycophenolate mofetil (MMF) (Arzip(®), Zentiva; CellCept(®), Roche Products; Myfenax(®), Teva), mycophenolate sodium (MPS) (Myfortic(®), Novartis Pharmaceuticals UK Ltd), sirolimus (SRL) (Rapamune(®), Pfizer) and everolimus (EVL) (Certican(®), Novartis) as maintenance therapy in adult renal transplantation. Clinical effectiveness searches were conducted until 18 November 2014 in MEDLINE (via Ovid), EMBASE (via Ovid), Cochrane Central Register of Controlled Trials (via Wiley Online Library) and Web of Science (via ISI), Cochrane Database of Systematic Reviews, Database of Abstracts of Reviews of Effects and Health Technology Assessment (The Cochrane Library via Wiley Online Library) and Health Management Information Consortium (via Ovid). Cost-effectiveness searches were conducted until 18 November 2014 using a costs or economic literature search filter in MEDLINE (via Ovid), EMBASE (via Ovid), NHS Economic Evaluation Database (via Wiley Online Library), Web of Science (via ISI), Health Economic Evaluations

  2. A nephron-based model of the kidneys for macro-to-micro α-particle dosimetry

    Science.gov (United States)

    Hobbs, Robert F.; Song, Hong; Huso, David L.; Sundel, Margaret H.; Sgouros, George

    2012-07-01

    Targeted α-particle therapy is a promising treatment modality for cancer. Due to the short path-length of α-particles, the potential efficacy and toxicity of these agents is best evaluated by microscale dosimetry calculations instead of whole-organ, absorbed fraction-based dosimetry. Yet time-integrated activity (TIA), the necessary input for dosimetry, can still only be quantified reliably at the organ or macroscopic level. We describe a nephron- and cellular-based kidney dosimetry model for α-particle radiopharmaceutical therapy, more suited to the short range and high linear energy transfer of α-particle emitters, which takes as input kidney or cortex TIA and through a macro to micro model-based methodology assigns TIA to micro-level kidney substructures. We apply a geometrical model to provide nephron-level S-values for a range of isotopes allowing for pre-clinical and clinical applications according to the medical internal radiation dosimetry (MIRD) schema. We assume that the relationship between whole-organ TIA and TIA apportioned to microscale substructures as measured in an appropriate pre-clinical mammalian model also applies to the human. In both, the pre-clinical and the human model, microscale substructures are described as a collection of simple geometrical shapes akin to those used in the Cristy-Eckerman phantoms for normal organs. Anatomical parameters are taken from the literature for a human model, while murine parameters are measured ex vivo. The murine histological slides also provide the data for volume of occupancy of the different compartments of the nephron in the kidney: glomerulus versus proximal tubule versus distal tubule. Monte Carlo simulations are run with activity placed in the different nephron compartments for several α-particle emitters currently under investigation in radiopharmaceutical therapy. The S-values were calculated for the α-emitters and their descendants between the different nephron compartments for both the

  3. Uteroplacental insufficiency affects kidney VEGF expression in a model of IUGR with compensatory glomerular hypertrophy and hypertension.

    Science.gov (United States)

    Baserga, Mariana; Bares, Allyson L; Hale, Merica A; Callaway, Christopher W; McKnight, Robert A; Lane, Pascale H; Lane, Robert H

    2009-06-01

    Low nephron endowment secondary to intrauterine growth restriction (IUGR) results in compensatory hypertrophy of the remaining glomeruli, which in turn is associated with hypertension. However, gender differences exist in the response of the kidney to injury, and IUGR female offspring seems protected from an unfavorable outcome. We previously reported differences in gender-specific gene expression in the IUGR kidney as well as increased circulating corticosterone levels following uteroplacental insufficiency (UPI). Vascular endothelial growth factor (VEGF), which is critical for renal development, is an important candidate in the IUGR kidney since its expression can be regulated by sex-steroids and glucocorticoids. We hypothesize that IUGR leads to altered kidney VEGF expression in a gender-specific manner. Following uterine ligation in the pregnant rat, UPI decreases renal VEGF levels in male and female IUGR animals at birth and through postnatal day 21. However, by day 120 of life, IUGR females have increased kidney VEGF expression, not present in the IUGR males. In addition, IUGR males exhibit increased serum testosterone levels as well as proteinuria. These findings are intriguing in light of the difference in glomerular hypertrophy observed: IUGR males show increased glomerular area when compared to IUGR females. In this model characterized by decreased nephron number and adult onset hypertension, UPI decreases renal VEGF expression during nephrogenesis. Our most intriguing finding is the increased renal VEGF levels in adult IUGR females, associated with a more benign phenotype. We suggest that the mechanisms underlying renal disease in response to IUGR are most likely regulated in a gender specific manner.

  4. Kidney Failure

    Science.gov (United States)

    Healthy kidneys clean your blood by removing excess fluid, minerals, and wastes. They also make hormones that keep your ... strong and your blood healthy. But if the kidneys are damaged, they don't work properly. Harmful ...

  5. Kidney Biopsy

    Science.gov (United States)

    ... sign of kidney disease or other urinary problems. albuminuria—a condition in which the urine has more-than-normal amounts of a protein called albumin. Albuminuria may be a sign of kidney disease. changes ...

  6. Kidney Failure

    Science.gov (United States)

    ... Become a Kidney Health Coach Clinical Scientist in Nephrology program Online continuining education Clinical trials Research Advocacy ... Become a Kidney Health Coach Clinical Scientist in Nephrology program Current CSN Fellow Previous CSN award recipients ...

  7. High-energy antiprotons from old supernova remnants

    CERN Document Server

    Blasi, Pasquale

    2009-01-01

    A recently proposed model (arXiv:0903.2794) explains the rise in energy of the positron fraction measured by the PAMELA satellite in terms of hadronic production of positrons in aged supernova remnants, and acceleration therein. Here we present a preliminary calculation of the anti-proton flux produced by the same mechanism. While the model is consistent with present data, a rise of the antiproton to proton ratio is predicted at high energy, which strikingly distinguishes this scenario from other astrophysical explanations of the positron fraction (like pulsars). We briefly discuss important implications for Dark Matter searches via antimatter.

  8. Remnant radio-loud AGN in the Herschel-ATLAS field

    Science.gov (United States)

    Mahatma, V. H.; Hardcastle, M. J.; Williams, W. L.; Brienza, M.; Brüggen, M.; Croston, J. H.; Gurkan, G.; Harwood, J. J.; Kunert-Bajraszewska, M.; Morganti, R.; Röttgering, H. J. A.; Shimwell, T. W.; Tasse, C.

    2018-01-01

    Only a small fraction of observed Active Galactic Nuclei display large-scale radio emission associated with jets, yet these radio-loud AGN have become increasingly important in models of galaxy evolution. In determining the dynamics and energetics of the radio sources over cosmic time, a key question concerns what happens when their jets switch off. The resulting `remnant' radio-loud AGN have been surprisingly evasive in past radio surveys, and therefore statistical information on the population of radio-loud AGN in their dying phase is limited. In this paper, with the recent developments of LOFAR and the VLA, we are able to provide a systematically selected sample of remnant radio-loud AGN in the Herschel-ATLAS field. Using a simple core-detection method, we constrain the upper limit on the fraction of remnants in our radio-loud AGN sample to 9 per cent, implying that the extended lobe emission fades rapidly once the core/jets turn off. We also find that our remnant sample has a wide range of spectral indices (-1.5≤slant α ^{1400}_{150}≤slant -0.5), confirming that the lobes of some remnants may possess flat spectra at low frequencies just as active sources do. We suggest that, even with the unprecedented sensitivity of LOFAR, our sample may still only contain the youngest of the remnant population.

  9. Astragaloside IV prevents acute kidney injury in two rodent models by inhibiting oxidative stress and apoptosis pathways.

    Science.gov (United States)

    Gui, Dingkun; Huang, Jianhua; Liu, Wei; Guo, Yongping; Xiao, Wenzhen; Wang, Niansong

    2013-04-01

    Oxidative stress and apoptosis play key role in the pathogenesis of acute kidney injury (AKI). We hypothesize that Astragaloside IV(AS-IV) prevents AKI through inhibiting oxidative stress and apoptosis. The rats were divided into sham control, saline-,vehicle-, or AS-IV-treated groups. AS-IV (20 mg/kg) was orally administered once daily to the rats for 7 consecutive days before terminating the experiments. In ischemia-induced AKI model, experimental rats were subjected to bilateral clamping of the renal arteries for 45 min, followed by reperfusion for 24 h. In contrast-induced AKI model, iopamidol (2.9 g iodine/kg) was administered intravenously into the rats. Renal function, histopathology, oxidative stress and apoptosis were evaluated in these models. Pretreatment with AS-IV significantly decreased blood urea nitrogen, serum creatinine, cystatin C and neutrophil gelatinase-associated lipocalin levels, as well as urinary kidney injury molecule-1 level and tubular injury. AS-IV also reduced oxidative stress and tubular cell apoptosis. The p38 mitogen-activated protein kinase phosphorylation and caspase-3 activity were elevated in kidney tissues from AKI rats, accompanied by an increase in Bax expression and a decrease in Bcl-2 expression at mRNA and protein levels. These changes were prevented by AS-IV pretreatment. Therefore, AS-IV can be developed as a novel therapeutic approach to prevent AKI through targeting inhibition of oxidative stress and apoptosis pathways.

  10. Functional imaging of acute kidney injury at 3 Tesla. Investigating multiple parameters using DCE-MRI and a two-compartment filtration model

    Energy Technology Data Exchange (ETDEWEB)

    Zoellner, Frank G.; Zimmer, Fabian; Schad, Lothar R. [Heidelberg Univ., Mannheim (Germany). Computer Assisted Clinical Medicine; Klotz, Sarah; Hoeger, Simone [Heidelberg Univ., Mannheim (Germany). Dept. of Medicine V

    2015-05-01

    To investigate how MR-based parameters reflect functional changes in kidneys with acute kidney injury (AKI) using dynamic contrast enhanced MRI and a two-compartment renal filtration model. MRI data of eight male Lewis rats were analyzed retrospectively. Five animals were subjected to AKI, three native rats served as control. All animals underwent perfusion imaging by dynamic contrast-enhanced MRI. Renal blood volume, glomerular filtration rate (GFR) as well as plasma and tubular mean transit times were estimated from regions-of-interest drawn in the renal cortex. Differences between healthy kidneys and kidneys subjected to AKI were analyzed using a paired t-test. Significant differences between ischemic and healthy kidneys could only be detected for the glomerular filtration rate. For all other calculated parameters, differences were present, however not significant. In rats with AKI, average single kidney GFR was 0.66 ± 0.37 ml/min for contralateral and 0.26 ± 0.12 ml/ min for diseased kidneys (P = 0.0254). For the healthy control group, the average GFR was 0.39 ± 0.06 ml/min and 0.41 ± 0.11 ml/min, respectively. Differences between diseased kidneys of AKI rats and ipsilateral kidneys of the healthy control group were significant (P=0.0381). Significant differences of functional parameters reflecting damage of the renal tissue of kidneys with AKI compared to the contralateral, healthy kidneys could only be detected by GFR. GFR might be a useful parameter that allows for a spatially resolved detection of abnormal changes of renal tissue by AKI.

  11. Kidney Disease

    Science.gov (United States)

    ... Breath? Talking to Your Parents - or Other Adults Kidney Disease KidsHealth > For Teens > Kidney Disease Print A A A What's in this article? ... uh-jist), a doctor who specializes in treating kidney diseases. The doctor will ask you about any concerns ...

  12. Kidney Transplant

    Science.gov (United States)

    ... kidney transplant offers more freedom and a better quality of life than dialysis. In making a decision about whether this is ... transplant, with little or no time spent on dialysis, can lead to better long-term ... life. Who can get a kidney transplant? Kidney patients ...

  13. Supernova remnants: the X-ray perspective

    NARCIS (Netherlands)

    Vink, J.

    2012-01-01

    Supernova remnants are beautiful astronomical objects that are also of high scientific interest, because they provide insights into supernova explosion mechanisms, and because they are the likely sources of Galactic cosmic rays. X-ray observations are an important means to study these objects. And

  14. Neutron Star/Supernova Remnant Associations

    OpenAIRE

    Kaspi, V. M.

    1999-01-01

    The evidence for associations between neutron stars and supernova remnants is reviewed. After summarizing the situation for young radio pulsars, I consider the evidence from associations that young neutron stars can have properties very different from those of radio pulsars. This, though still controversial, shakes our simple perception of the Crab pulsar as prototypical of the young neutron star population.

  15. [Expression and role of soluble epoxide hydrolase in renal tissue of two kidneys one clip hypertension rats model].

    Science.gov (United States)

    Pan, Yue-juan; Tao, Zhong-fei; Wang, Qian; Lu, Min; Guan, You-fei; Zhu, Yi; Wang, Yue

    2011-12-18

    To investigate renal expression of soluble epoxide hydrolase (sEH) in 2-kidney-1-clip rats and explore the role of sEH in renal arterial stenosis hypertensive development. Hypertensive models were established in Sprague-Dawly rats by chronic partial occlusion of left renal artery. In the study,16 male Sprague-Dawly rats were randomized into sham operation group and 2-kidney-1-lip (2K1C) group (n=8, each group), and were observed for 40 days. Before operation and every ten days after operation, systolic blood pressure (SBP) was measured and twenty-four-hour urine was collected. At the end of the observation, the blood and kidneys were harvested. The serum Na,24-hour urine protein excretion were measured. Renin activity and angiotensin II concentrition in plasm and renal tissue were evaluated by radioimmunoassay (RIA).The expression of sEH, peroxisome proliferator-activated receptor-γ (PPARγ) in kidneys were assessed by immunohistochemistry and Western blotting. Histology was analysed after kidney sections were stained by Grocott-Gomori methenamine-silver nitrate. After surgery, the systolic blood pressure in 2K1C group gradually became higher than that in sham group. Urine protein excretion was statistically increased in 2K1C group on the 30 th and 40 th days, while serum sodium was of no significant difference from those of the two groups. Renin-angiotensin system in both clipped and nonclipped kidneys were also invoked by the 2K1C surgery. Both sEH and PPARγ were upregulated in renocortex and renomedulla in 2K1C group. The two groups were compared: in SBP,on the 10 th day, (106.70±7.71) vs.(124.04±6.79) mmHg, P150.40±11.76) mmHg, PUrine protein excretion,on the 30 th day,(206.81±37.61)vs.(292.33±20.53)mg/d, P=0.005; Serum sodium, (179.76±29.20) vs. (157.72±51.00)mmol/L, P=0.44; Renin activity[plasm(50.00±13.66) vs.(132.90± 31.22)ng/(L×h),P=0.03; clipped kidney(128.40±36.88)vs.(324.90±56.66)ng/(g×h), P=0.01; nonclipped kidney(103.00±19.87)vs.(345

  16. Nephroprotection of punicalagin in rat model of endotoxemic acute kidney injury.

    Science.gov (United States)

    Fouad, Amr A; Qutub, Hatem O; Al-Melhim, Walid N

    2016-09-01

    The potential nephroprotection of punicalagin (PNG) against lipopolysaccharide (LPS)-induced acute kidney injury in rats was investigated. Rats received a single i.v. dose of LPS (5 mg/kg), and treated with PNG (50 mg/kg, i.p.), 1 h before, and 1 h following LPS administration. LPS caused significant increases of serum creatinine and neutrophil gelatinase-associated lipocalin. LPS also resulted in significant increases in interleukin-18, tumor necrosis factor-α, interleukin-6, malondialdehyde, nitric oxide, Bax/Bcl-2 ratio and myeloperoxidase, inducible nitric oxide synthase, caspases 3, 8 and 9 activities, and a significant decrease in total antioxidant capacity in kidney tissues. PNG significantly ameliorated the alterations in the measured parameters. Additionally, PNG attenuated the histopathological injury and reduced kidney injury molecule-1 expression in kidneys of rats that received LPS. It was concluded that PNG ameliorated endotoxemic acute kidney injury in rats by counteracting inflammation, oxidative/nitrative stress and apoptosis.

  17. Dynamic renal scintigraphic estimation of deceased donor kidneys in a rat model

    Directory of Open Access Journals (Sweden)

    Huseyin Aydin Mitil

    2017-01-01

    Full Text Available At present a large number of the renal transplantations are being performed from the deceased donors. The success of these transplantations depends on the viability of the deceased donor kidneys. The aim of this study was to investigate the reliability of scintigraphic estimation of function of deceased donor kidneys by comparing the histopathologic and scintigraphic findings. Ten rats were included in the study (2–3 months old, 250–300 g, all male. Control scintigraphy was performed to all the rats by injection of 37 MBq Tc-99m DTPA from the tail vein in a dynamic manner. Brain death of the rats was achieved by inflation of a Fogartys catheter in the cranial cavity. Immediately, after brain death confirmation, dynamic renal scintigraphy was performed with the same parameters of control scintigraphy. In the comparison of scintigraphies obtained in the before and just after brain death period, there was impairment of tubular functions, concentration and excretion functions in the postbrain death period. In the immediate postbrain death period, there was a significant elevation in the glomerular filtration rate and time to maximum concentration values. In the histopathological evaluation of the kidney samples in the postbrain death period, there were definitive findings of tubular impairment. Dynamic renal scintigraphy also demonstrated definite impairment of tubular system and tubular functions in the deceased donor kidneys. This could explain the reason of the increased frequency of acute tubular necrosis seen among deceased donor kidneys.

  18. Renal Anemia Model Mouse Established by Transgenic Rescue with an Erythropoietin Gene Lacking Kidney-Specific Regulatory Elements

    Science.gov (United States)

    Hirano, Ikuo; Suzuki, Norio; Yamazaki, Shun; Sekine, Hiroki; Minegishi, Naoko

    2016-01-01

    ABSTRACT The erythropoietin (Epo) gene is under tissue-specific inducible regulation. Because the kidney is the primary EPO-producing tissue in adults, impaired EPO production in chronic kidney disorders results in serious renal anemia. The Epo gene contains a liver-specific enhancer in the 3′ region, but the kidney-specific enhancer for gene expression in renal EPO-producing (REP) cells remains elusive. Here, we examined a conserved upstream element for renal Epo regulation (CURE) region that spans 17.4 kb to 3.6 kb upstream of the Epo gene and harbors several phylogenetically conserved elements. We prepared various Epo gene-reporter constructs utilizing a bacterial artificial chromosome and generated a number of transgenic-mouse lines. We observed that deletion of the CURE region (δCURE) abrogated Epo gene expression in REP cells. Although transgenic expression of the δCURE construct rescued Epo-deficient mice from embryonic lethality, the rescued mice had severe EPO-dependent anemia. These mouse lines serve as an elaborate model for the search for erythroid stimulatory activity and are referred to as AnRED (anemic model with renal EPO deficiency) mice. We also dissected the CURE region by exploiting a minigene harboring four phylogenetically conserved elements in reporter transgenic-mouse analyses. Our analyses revealed that Epo gene regulation in REP cells is a complex process that utilizes multiple regulatory influences. PMID:27920250

  19. GALACTIC AND EXTRAGALACTIC SUPERNOVA REMNANTS AS SITES OF PARTICLE ACCELERATION

    Directory of Open Access Journals (Sweden)

    Manami Sasaki

    2013-12-01

    Full Text Available Supernova remnants, owing to their strong shock waves, are likely sources of Galactic cosmic rays. Studies of supernova remnants in X-rays and gamma rays provide us with new insights into the acceleration of particles to high energies. This paper reviews the basic physics of supernova remnant shocks and associated particle acceleration and radiation processes. In addition, the study of supernova remnant populations in nearby galaxies and the implications for Galactic cosmic ray distribution are discussed.

  20. Incidence of kidney stones in kidney transplant recipients: A systematic review and meta-analysis.

    Science.gov (United States)

    Cheungpasitporn, Wisit; Thongprayoon, Charat; Mao, Michael A; Kittanamongkolchai, Wonngarm; Jaffer Sathick, Insara J; Dhondup, Tsering; Erickson, Stephen B

    2016-12-24

    To evaluate the incidence and characteristics of kidney stones in kidney transplant recipients. A literature search was performed using MEDLINE, EMBASE, and Cochrane Database of Systematic Reviews from the inception of the databases through March 2016. Studies assessing the incidence of kidney stones in kidney transplant recipients were included. We applied a random-effects model to estimate the incidence of kidney stones. Twenty one studies with 64416 kidney transplant patients were included in the analyses to assess the incidence of kidney stones after kidney transplantation. The estimated incidence of kidney stones was 1.0% (95%CI: 0.6%-1.4%). The mean duration to diagnosis of kidney stones after kidney transplantation was 28 ± 22 mo. The mean age of patients with kidney stones was 42 ± 7 years. Within reported studies, approximately 50% of kidney transplant recipients with kidney stones were males. 67% of kidney stones were calcium-based stones (30% mixed CaOx/CaP, 27%CaOx and 10%CaP), followed by struvite stones (20%) and uric acid stones (13%). The estimated incidence of kidney stones in patients after kidney transplantation is 1.0%. Although calcium based stones are the most common kidney stones after transplantation, struvite stones (also known as "infection stones") are not uncommon in kidney transplant recipients. These findings may impact the prevention and clinical management of kidney stones after kidney transplantation.

  1. Quantitative arterial spin labelling perfusion measurements in rat models of renal transplantation and acute kidney injury at 3 T

    Energy Technology Data Exchange (ETDEWEB)

    Zimmer, Fabian; Schad, Lothar R.; Zoellner, Frank G. [Heidelberg Univ., Mannheim (Germany). Computer Assisted Clinical Medicine; Klotz, Sarah; Hoeger, Simone; Yard, Benito A.; Kraemer, Bernhard K. [Heidelberg Univ., Mannheim (Germany). Dept. of Medicine V

    2017-05-01

    To employ ASL for the measurement of renal cortical perfusion in particular renal disorders typically associated with graft loss and to investigate its potential to detect and differentiate the related functional deterioration i.e., in a setting of acute kidney injury (AKI) as well as in renal grafts showing acute and chronic transplant rejection. 14 Lewis rats with unilateral ischaemic AKI and 43 Lewis rats with renal grafts showing acute or chronic rejections were used. All ASL measurements in this study were performed on a 3 T MR scanner using a FAIR True-FISP approach to assess renal blood flow (RBF). Perfusion maps were calculated and the cortical blood flow was determined using a region-of-interest based analysis. RBF of healthy and AKI kidneys as well as of both rejection models, were compared. In a subsample of 20 rats, creatinine clearance was measured and correlated with cortical perfusion. RBF differs significantly between healthy and AKI kidneys (P < 0.001) with a mean difference of 213 ± 80 ml/100 g/min. Renal grafts with chronic rejections show a significantly higher (P < 0.001) mean cortical perfusion (346 ± 112 ml/100 g/min) than grafts with acute rejection (240 ± 66 ml/100 g/min). Both transplantation models have a significantly (P < 0.001) lower perfusion than healthy kidneys. Renal creatinine clearance is significantly correlated (R = 0.85, P < 0.001) with cortical blood flow. Perfusion measurements with ASL have the potential to become a valuable diagnostic tool, regarding the detection of renal impairment and the differentiation of disorders that lead to a loss of renal function and that are typically associated with graft loss.

  2. Shocks in Dense Clouds in the Vela Supernova Remnant: FUSE

    Science.gov (United States)

    Nichols, Joy; Sonneborn, George (Technical Monitor)

    2002-01-01

    We have obtained 8 LWRS FUSE spectra to study a recently identified interaction of the Vela supernova remnant with a dense cloud region along its western edge. The goal is to quantify the temperature, ionization, density, and abundance characteristics associated with this shock/dense cloud interface by means of UV absorption line studies. Our detection of high-velocity absorption line C I at +90 to +130 km/s with IUE toward a narrow region interior to the Vela SNR strongly suggests the Vela supernova remnant is interacting with a dense ISM or molecular cloud. The shock/dense cloud interface is suggested by (1) the rarity of detection of high-velocity C I seen in IUE spectra, (2) its very limited spatial distribution in the remnant, and (3) a marked decrease in X-ray emission in the region immediately west of the position of these stars where one also finds a 100 micron emission ridge in IRAS images. We have investigated the shock physics and general properties of this interaction region through a focussed UV absorption line study using FUSE spectra. We have FUSE data on OVI absorption lines observed toward 8 stars behind the Vela supernova remnant (SNR). We compare the OVI observations with IUE observations of CIV absorption toward the same stars. Most of the stars, which are all B stars, have complex continua making the extraction of absorption lines difficult. Three of the stars, HD 72088, HD 72089 and HD 72350, however, are rapid rotators (v sin i less than 100 km/s) making the derivation of absorption column densities much easier. We have measured OVI and CIV column densities for the "main component" (i.e. the low velocity component) for these stars. In addition, by removing the H2 line at 1032.35A (121.6 km/s relative to OVI), we find high velocity components of OVI at approximately 150 km/s that we attribute to the shock in the Vela SNR. The column density ratios and magnitudes are compared to both steady shock models and results of hydrodynamical SNR

  3. Medullary Sponge Kidney

    Science.gov (United States)

    ... Sponge Kidney? Complications of medullary sponge kidney include hematuria, or blood in the urine kidney stones urinary ... both kidneys. Complications of medullary sponge kidney include hematuria, or blood in the urine kidney stones urinary ...

  4. Vitamin K metabolism in a rat model of chronic kidney disease

    Science.gov (United States)

    Background: Patients with chronic kidney disease (CKD) have very high levels of uncarboxylated, inactive, extra-hepatic vitamin K-dependent proteins measured in circulation, putting them at risk for complications of vitamin K deficiency. The major form of vitamin K found in the liver is phylloquinon...

  5. Molecular Ultrasound Imaging of Tissue Inflammation Using an Animal Model of Acute Kidney Injury.

    Science.gov (United States)

    Hoyt, Kenneth; Warram, Jason M; Wang, Dezhi; Ratnayaka, Sithira; Traylor, Amie; Agarwal, Anupam

    2015-12-01

    The objective of this study was to evaluate the use of molecular ultrasound (US) imaging for monitoring the early inflammatory effects following acute kidney injury. A population of rats underwent 30 min of renal ischemia (acute kidney injury, N = 6) or sham injury (N = 4) using established surgical methods. Animals were divided and molecular US imaging was performed during the bolus injection of a targeted microbubble (MB) contrast agent to either P-selectin or vascular cell adhesion molecule 1 (VCAM-1). Imaging was performed before surgery and 4 and 24 h thereafter. After manual segmentation of renal tissue space, the molecular US signal was calculated as the difference between time-intensity curve data before MB injection and after reaching steady-state US image enhancement. All animals were terminated after the 24 h imaging time point and kidneys excised for immunohistochemical (IHC) analysis. Renal inflammation was analyzed using molecular US imaging. While results using the P-selectin and VCAM-1 targeted MBs were comparable, it appears that the former was more sensitive to biomarker expression. All molecular US imaging measures had a positive correlation with IHC findings. Acute kidney injury is a serious disease in need of improved noninvasive methods to help diagnose the extent of injury and monitor the tissue throughout disease progression. Molecular US imaging appears well suited to address this challenge and more research is warranted.

  6. Chronic renoprotective effect of pulsatile perfusion machine RM3 and IGL-1 solution in a preclinical kidney transplantation model

    Directory of Open Access Journals (Sweden)

    Thuillier Raphael

    2012-11-01

    Full Text Available Abstract Background Machine perfusion (MP of kidney graft provides benefits against preservation injury, however decreased graft quality requires optimization of the method. We examined the chronic benefits of MP on kidney grafts and the potential improvements provided by IGL-1 solution. Method We used an established autotransplantation pig kidney model to study the effects of MP against the deleterious effects of warm ischemia (WI: 60 minutes followed by 22 hours of cold ischemia in MP or static cold storage (CS followed by autotransplantation. MPS and IGL-1 solutions were compared. Results Animal survival was higher in MPS-MP and both IGL groups. Creatinine measurement did not discriminate between the groups, however MPS-MP and both IGL groups showed decreased proteinuria. Chronic fibrosis level was equivalent between the groups. RTqPCR and immunohistofluorescent evaluation showed that MP and IGL-1 provided some protection against epithelial to mesenchymal transition and chronic lesions. IGL-1 was protective with both MP and CS, particularly against chronic inflammation, with only small differences between the groups. Conclusion IGL-1 used in either machine or static preservation offers similar levels of protection than standard MP. The compatibility of IGL-1 with both machine perfusion and static storage could represent an advantage for clinical teams when choosing the correct solution to use for multi-organ collection. The path towards improving machine perfusion, and organ quality, may involve the optimization of the solution and the correct use of colloids.

  7. CD47 blockade reduces ischemia-reperfusion injury and improves outcomes in a rat kidney transplant model.

    Science.gov (United States)

    Lin, Yiing; Manning, Pamela T; Jia, Jianluo; Gaut, Joseph P; Xiao, Zhenyu; Capoccia, Benjamin J; Chen, Chun-Cheng; Hiebsch, Ronald R; Upadhya, Gundumi; Mohanakumar, Thalachallour; Frazier, William A; Chapman, William C

    2014-08-27

    Ischemia-reperfusion injury (IRI) significantly contributes to delayed graft function and inflammation, leading to graft loss. Ischemia-reperfusion injury is exacerbated by the thrombospondin-1-CD47 system through inhibition of nitric oxide signaling. We postulate that CD47 blockade and prevention of nitric oxide inhibition reduce IRI in organ transplantation. We used a syngeneic rat renal transplantation model of IRI with bilaterally nephrectomized recipients to evaluate the effect of a CD47 monoclonal antibody (CD47mAb) on IRI. Donor kidneys were flushed with CD47mAb OX101 or an isotype-matched control immunoglobulin and stored at 4°C in University of Wisconsin solution for 6 hr before transplantation. CD47mAb perfusion of donor kidneys resulted in marked improvement in posttransplant survival, lower levels of serum creatinine, blood urea nitrogen, phosphorus and magnesium, and less histological evidence of injury. In contrast, control groups did not survive more than 5 days, had increased biochemical indicators of renal injury, and exhibited severe pathological injury with tubular atrophy and necrosis. Recipients of CD47mAb-treated kidneys showed decreased levels of plasma biomarkers of renal injury including Cystatin C, Osteopontin, Tissue Inhibitor of Metalloproteinases-1 (TIMP1), β2-Microglobulin, Vascular Endothelial Growth Factor A (VEGF-A), and clusterin compared to the control group. Furthermore, laser Doppler assessment showed higher renal blood flow in the CD47mAb-treated kidneys. These results provide strong evidence for the use of CD47 antibody-mediated blockade to reduce IRI and improve organ preservation for renal transplantation.

  8. A modified theoretical Σ − D relation for supernova remnants: I. The case of constant temperature within the supernova remnant

    Directory of Open Access Journals (Sweden)

    Urošević Dejan V.

    2003-01-01

    Full Text Available We present a modification of the theoretical Σ − D relation for supernova remnants (SNRs in the adiabatic expansion phase. This modification is based on the convolution of the relation first derived by Shklovsky with the Σ − D relation derived in this paper for thermal bremsstrahlung radiation from the ionized gas cloud. We adopt McKee & Ostriker’s model for the components of the interstellar medium as part of our derivation. The modified Shklovsky theory agrees well with empirical results. Kesteven’s modified theoretical relation gives the best agreement with the updated Galactic empirical Σ − D relation.

  9. Anterior cruciate ligament remnant and its values for preservation

    Directory of Open Access Journals (Sweden)

    Takeshi Muneta

    2017-01-01

    Full Text Available Controversy surrounds the remnant-preserving anterior cruciate ligament surgery. Advantages of remnant preservation have been reported in regard to better healing and knee function, although no consensus has been reached. This review article discussed the value and meaning of anterior cruciate ligament remnant preservation in several sections such as effects on healing, remnant classification, biomechanical evaluation, relation to proprioception, animal studies, and clinical studies. We hope that this review will facilitate further discussion and investigation for better treatment of anterior cruciate ligament injuries. So far, the current reviews have not provided sufficient scientific evidence to support the value of preserving the remnant.

  10. Acute kidney failure

    Science.gov (United States)

    ... kidney injury. Alternative Names Kidney failure; Renal failure; Renal failure - acute; ARF; Kidney injury - acute Images Kidney anatomy References Devarajan P. Biomarkers for assessment of renal ...

  11. Incidence of kidney stones in kidney transplant recipients: A systematic review and meta-analysis

    OpenAIRE

    Cheungpasitporn, Wisit; Thongprayoon, Charat; Mao, Michael A; Kittanamongkolchai, Wonngarm; Jaffer Sathick, Insara J; Dhondup, Tsering; Erickson, Stephen B

    2016-01-01

    AIM To evaluate the incidence and characteristics of kidney stones in kidney transplant recipients. METHODS A literature search was performed using MEDLINE, EMBASE, and Cochrane Database of Systematic Reviews from the inception of the databases through March 2016. Studies assessing the incidence of kidney stones in kidney transplant recipients were included. We applied a random-effects model to estimate the incidence of kidney stones. RESULTS Twenty one studies with 64416 kidney transplant pa...

  12. Radioactivity and Electron Acceleration in Supernova Remnants

    OpenAIRE

    Zirakashvili, V. N.; Aharonian, F. A.

    2010-01-01

    We argue that the decays of radioactive nuclei related to $^{44}$Ti and $^{56}$Ni ejected during supernova explosions can provide a vast pool of mildly relativistic positrons and electrons which are further accelerated to ultrarelativistic energies by reverse and forward shocks. This interesting link between two independent processes - the radioactivity and the particle acceleration - can be a clue for solution of the well known theoretical problem of electron injection in supernova remnants....

  13. Real-time measurement of kidney tubule fluid nitric oxide concentrations in early diabetes: disparate changes in different rodent models.

    Science.gov (United States)

    Levine, David Z; Iacovitti, Michelle

    2006-08-01

    There are several reports indicating that nitric oxide (NO) plays a role in the kidney hyperfiltration seen in the early stages of diabetes mellitus (DM). Whole kidney GFR and single nephron GFR (SNGFR) have been reported to decrease after nitric oxide synthase (NOS) inhibition. To date, no direct, in vivo, quantitative NO measurements have been made within the kidney in any models of early diabetes. To assess the possible association of changes in tubular fluid nitric oxide concentrations (TF [NO]) with early diabetes, a specially modified NO electrode with a tip diameter of about 7 microm was used to measure NO in single tubules in seven rodent groups. In the Sprague-Dawley (SD) rat model, TF [NO] increased by 50% after streptozotocin (STZ) induced DM1. In the B6129G2/J mouse, control TF [NO] was more than twice the rat control value and fell by 50% after STZ treatment. In three other groups of mice-db/db (B6.Cg-m+/+Lepr(db)/J) Type II diabetic (DM2) mouse, db/m (its heterozygote), and the corresponding wild type (WT)-TF [NO] was also much higher than in the rat, and unlike the B6129G2/J STZ diabetic mouse, did not change after the onset of diabetes. Blood glucose concentrations were similar in the three diabetic groups. Accordingly, in different rodent models of diabetes, in vivo TF [NO], measured in real time, varies significantly in control animals and directionally in different models of DM1 and DM2.

  14. Lack of Benefit of Early Intervention with Dietary Flax and Fish Oil and Soy Protein in Orthologous Rodent Models of Human Hereditary Polycystic Kidney Disease.

    Directory of Open Access Journals (Sweden)

    Tamio Yamaguchi

    Full Text Available Rationale for dietary advice in polycystic kidney disease (PKD is based in part on animal studies that have examined non-orthologous models with progressive development of cystic disease. Since no model completely mimics human PKD, the purpose of the current studies was to examine the effects of dietary soy protein (compared to casein or oils enriched in omega-3 fatty acids (fish or flax oil compared to soy oil on early disease progression in two orthologous models of PKD. The models studied were Pkd2WS25/- mice as a model of autosomal dominant PKD, and PCK rats as a model of autosomal recessive PKD. After 13 weeks of feeding, dietary fish (but not flax oil resulted in larger kidneys and greater kidney water content in female Pkd2WS25/- compared to control mice. After 12 weeks of feeding male PCK compared to control rats, both fish and flax compared to soy oil resulted in enlarged kidneys and livers, greater kidney water content and higher kidney cyst area in diseased rats. Dietary soy protein compared to casein had no effects in Pkd2WS25/- compared to control mice. In PCK rats, kidney and liver histology were not improved, but lower proteinuria and higher urine pH suggest that soy protein could be beneficial in the long term. Therefore, in contrast to studies in non-orthologous models during the progressive development phase, these studies in orthologous PKD models do not support dietary advice to increase soy protein or oils enriched in omega-3 oils in early PKD.

  15. SUPERNOVA REMNANT PROGENITOR MASSES IN M31

    Energy Technology Data Exchange (ETDEWEB)

    Jennings, Zachary G.; Williams, Benjamin F.; Dalcanton, Julianne J.; Gilbert, Karoline M.; Fouesneau, Morgan; Weisz, Daniel R. [Department of Astronomy, University of Washington Seattle, Box 351580, WA 98195 (United States); Murphy, Jeremiah W. [Department of Astrophysical Sciences, Princeton University, Princeton, NJ 08544 (United States); Dolphin, Andrew E., E-mail: zachjenn@uw.edu, E-mail: adolphin@raytheon.com [Raytheon, 1151 East Hermans Road, Tucson, AZ 85706 (United States)

    2012-12-10

    Using Hubble Space Telescope photometry, we age-date 59 supernova remnants (SNRs) in the spiral galaxy M31 and use these ages to estimate zero-age main-sequence masses (M{sub ZAMS}) for their progenitors. To accomplish this, we create color-magnitude diagrams (CMDs) and employ CMD fitting to measure the recent star formation history of the regions surrounding cataloged SNR sites. We identify any young coeval population that likely produced the progenitor star, then assign an age and uncertainty to that population. Application of stellar evolution models allows us to infer the M{sub ZAMS} from this age. Because our technique is not contingent on identification or precise location of the progenitor star, it can be applied to the location of any known SNRs. We identify significant young star formation around 53 of the 59 SNRs and assign progenitor masses to these, representing a factor of {approx}2 increase over currently measured progenitor masses. We consider the remaining six SNRs as either probable Type Ia candidates or the result of core-collapse progenitors that have escaped their birth sites. In general, the distribution of recovered progenitor masses is bottom-heavy, showing a paucity of the most massive stars. If we assume a single power-law distribution, dN/dM{proportional_to}M{sup {alpha}}, then we find a distribution that is steeper than a Salpeter initial mass function (IMF) ({alpha} = -2.35). In particular, we find values of {alpha} outside the range -2.7 {>=} {alpha} {>=} -4.4 to be inconsistent with our measured distribution at 95% confidence. If instead we assume a distribution that follows a Salpeter IMF up to some maximum mass, then we find that values of M{sub Max} > 26 are inconsistent with the measured distribution at 95% confidence. In either scenario, the data suggest that some fraction of massive stars may not explode. The result is preliminary and requires more SNRs and further analysis. In addition, we use our distribution to estimate a

  16. A simulation model to estimate cost-offsets for a disease-management program for chronic kidney disease.

    Science.gov (United States)

    Gandjour, Afschin; Tschulena, Ulrich; Steppan, Sonja; Gatti, Emanuele

    2015-04-01

    The aim of this paper is to develop a simulation model that analyzes cost-offsets of a hypothetical disease management program (DMP) for patients with chronic kidney disease (CKD) in Germany compared to no such program. A lifetime Markov model with simulated 65-year-old patients with CKD was developed using published data on costs and health status and simulating the progression to end-stage renal disease (ESRD), cardiovascular disease and death. A statutory health insurance perspective was adopted. This modeling study shows considerable potential for cost-offsets from a DMP for patients with CKD. The potential for cost-offsets increases with relative risk reduction by the DMP and baseline glomerular filtration rate. Results are most sensitive to the cost of dialysis treatment. This paper presents a general 'prototype' simulation model for the prevention of ESRD. The model allows for further modification and adaptation in future applications.

  17. The Impact of Progenitor Mass Loss on the Dynamical and Spectral Evolution of Supernova Remnants

    Science.gov (United States)

    Patnaude, Daniel J.; Lee, Shiu-Hang; Slane, Patrick O.; Badenes, Carles; Nagataki, Shigehiro; Ellison, Donald C.; Milisavljevic, Dan

    2017-11-01

    There is now substantial evidence that the progenitors of some core-collapse supernovae undergo enhanced or extreme mass loss prior to explosion. The imprint of this mass loss is observed in the spectra and dynamics of the expanding blast wave on timescales of days to years after core collapse, and the effects on the spectral and dynamical evolution may linger long after the supernova has evolved into the remnant stage. In this paper, we present, for the first time, largely self-consistent end-to-end simulations for the evolution of a massive star from the pre-main sequence, up to and through core collapse, and into the remnant phase. We present three models and compare and contrast how the progenitor mass-loss history impacts the dynamics and spectral evolution of the supernovae and supernova remnants. We study a model that only includes steady mass loss, a model with enhanced mass loss over a period of ˜5000 yr prior to core collapse, and a model with extreme mass loss over a period of ˜500 yr prior to core collapse. The models are not meant to address any particular supernova or supernova remnant, but rather to highlight the important role that the progenitor evolution plays in the observable qualities of supernovae and supernova remnants. Through comparisons of these three different progenitor evolution scenarios, we find that the mass loss in late stages (during and after core carbon burning) can have a profound impact on the dynamics and spectral evolution of the supernova remnant centuries after core collapse.

  18. Acute and Chronic Kidney Injury in a Non-Human Primate Model of Partial-Body Irradiation with Bone Marrow Sparing.

    Science.gov (United States)

    Cohen, Eric P; Hankey, Kim G; Bennett, Alexander W; Farese, Ann M; Parker, George A; MacVittie, Thomas J

    2017-12-01

    The development of medical countermeasures against acute and delayed multi-organ injury requires animal models predictive of the human response to radiation and its treatment. Late chronic injury is a well-known feature of radiation nephropathy, but acute kidney injury has not been reported in an appropriate animal model. We have established a single-fraction partial-body irradiation model with minimal marrow sparing in non-human primates. Subject-based medical management was used including parenteral fluids according to prospective morbidity criteria. We show herein that 10 or 11 Gy exposures caused both acute and chronic kidney injury. Acute and chronic kidney injury appear to be dose-independent between 10 and 11 Gy. Acute kidney injury was identified during the first 50 days postirradiation and appeared to resolve before the occurrence of chronic kidney injury, which was progressively more severe up to 180 days postirradiation, which was the end of the study. These findings show that mitigation of the acute radiation syndrome by medical management will unmask delayed late effects that occur months after partial-body irradiation. They further emphasize that both acute and chronic changes in kidney function must be taken into account in the use and timing of mitigators and medical management for acute radiation syndrome and delayed effects of acute radiation exposure (DEARE).

  19. The Need for Accurate Risk Prediction Models for Road Mapping, Shared Decision Making and Care Planning for the Elderly with Advanced Chronic Kidney Disease.

    Science.gov (United States)

    Stryckers, Marijke; Nagler, Evi V; Van Biesen, Wim

    2016-11-01

    As people age, chronic kidney disease becomes more common, but it rarely leads to end-stage kidney disease. When it does, the choice between dialysis and conservative care can be daunting, as much depends on life expectancy and personal expectations of medical care. Shared decision making implies adequately informing patients about their options, and facilitating deliberation of the available information, such that decisions are tailored to the individual's values and preferences. Accurate estimations of one's risk of progression to end-stage kidney disease and death with or without dialysis are essential for shared decision making to be effective. Formal risk prediction models can help, provided they are externally validated, well-calibrated and discriminative; include unambiguous and measureable variables; and come with readily applicable equations or scores. Reliable, externally validated risk prediction models for progression of chronic kidney disease to end-stage kidney disease or mortality in frail elderly with or without chronic kidney disease are scant. Within this paper, we discuss a number of promising models, highlighting both the strengths and limitations physicians should understand for using them judiciously, and emphasize the need for external validation over new development for further advancing the field.

  20. [Toward a new model of pharmacy management comprehensive care of patients with chronic kidney disease].

    Science.gov (United States)

    Muros-Ortega, M; Ramos, R; Molina, M

    2014-07-01

    The treatment of chronic kidney disease represents 2.5% of the National Healthcare System budget. Given the panorama of economic crisis, actions aimed at containing the costs in this kind of pathologies should be implemented. Centralization of the management of the medications used for the treatment of chronic kidney disease and its complications aims at reducing the pharmaceutical expenditure. The new contracts of public healthcare administrations with companies of dialysis centers establish a single price by which the contractor takes care of the integral management of the patients, including the dialysis therapy and pharmacological treatment. Drug management at dialysis centers will be handled by specialized pharmacists by means of the creation of pharmacy departments or drug warehouse. these measures aim at improving healthcare of the patient in hemodialysis program, with health benefits at a lower healthcare cost. Copyright AULA MEDICA EDICIONES 2014. Published by AULA MEDICA. All rights reserved.

  1. Left Behind: A Bound Remnant from a White Dwarf Supernova?

    Science.gov (United States)

    Jha, Saurabh

    2017-08-01

    Type Ia supernovae (SN Ia) have enormous importance to cosmology and astrophysics, but their progenitors and explosion mechanisms are not understood in detail. Recently, observations and theoretical models have suggested that not all thermonuclear white-dwarf supernova explosions are normal SN Ia. In particular, type Iax supernovae (peculiar cousins to SN Ia), are thought to be exploding white dwarfs that are not completely disrupted, leaving behind a bound remnant. In deep and serendipitous HST pre-explosion data, we have discovered a luminous, blue progenitor system for the type Iax SN 2012Z in NGC 1309, which we interpret as a helium-star donor to the exploding white dwarf. HST observations of SN 2012Z in 2016, when the supernova light was expected to have faded away, still show a source at the location, as expected in our model where the pre-explosion flux was coming from the companion. However, the 2016 data also show a surprise: an excess flux compared to the progenitor system. Our proposed observations here will help unravel the mystery of that excess flux: is it from the bound ex-white dwarf remnant? Or is it from the shocked companion star that has been bombarded by supernova ejecta? Either of these possibilities would provide key new evidence as to the nature of these white dwarf supernovae.

  2. Comparison of Cox Model and K-Nearest Neighbor to Estimation of Survival in Kidney Transplant Patients

    Directory of Open Access Journals (Sweden)

    J. Faradmal

    2016-01-01

    Full Text Available Introduction & Objective: Cox model is a common method to estimate survival and validity of the results is dependent on the proportional hazards assumption. K- Nearest neighbor is a nonparametric method for survival probability in heterogeneous communities. The purpose of this study was to compare the performance of k- nearest neighbor method (K-NN with Cox model. Materials & Methods: This retrospective cohort study was conducted in Hamadan Province, on 475 patients who had undergone kidney transplantation from 1994 to 2011. Data were extracted from patients’ medical records using a checklist. The duration of the time between kidney transplantation and rejection was considered as the surviv­al time. Cox model and k- nearest neighbor method were used for Data modeling. The prediction error Brier score was used to compare the performance models. Results: Out of 475 transplantations, 55 episodes of rejection occurred. 5, 10 and 15 year survival rates of transplantation were 91.70 %, 84.90% and 74.50%, respectively. The number of neighborhood optimized using cross validation method was 45. Cumulative Brier score of k-NN algorithm for t=5, 10 and 15 years were 0.003, 0.006 and 0.007, respectively. Cumulative Brier of score Cox model for t=5, 10 and 15 years were 0.036, 0.058 and 0.058, respectively. Prediction error of k-NN algorithm for t=5, 10 and 15 years was less than Cox model that shows that the k-NN method outperforms. Conclusions: The results of this study show that the predictions of KNN has higher accuracy than the Cox model when sample sizes and the number of predictor variables are high. Sci J Hamadan Univ Med Sci . 2016; 22 (4 :300-308

  3. The role of hypertriglyceridemia for acute kidney injury in the course of acute pancreatitis and an animal model.

    Science.gov (United States)

    Wu, Congye; Zou, Lei; Shi, Shujing; Tong, Zhihui; Shen, Xiao; Yang, Dongliang; Ke, Lu; Li, Weiqin; Li, Jieshou

    The aim of this study was to investigate the role of hypertriglyceridemia for acute kidney injury (AKI) in the course of acute pancreatitis. Patients with acute pancreatitis were retrospectively divided into four groups according to admission triglyceride: normal group, mild HTG group, moderate HTG group and severe HTG group. Clinical characteristics were compared among these groups. Wild type (WT) mice and Human ApoC III transgenic (ApoCIIItg) mice were used in the next animal experiments. Severe acute pancreatitis (SAP) model was established by retrograde injection of 0.5% sodium taurocholate (0.1 ml/100 g) from duodenum to pancreatic duct. Histological scores, serum amylase, creatinine, usea nitrogen were compared between WT mice and ApoCIIItg mice. Two hundred and sixty-two patients were classified into 4 groups: normal TG (104, 39.7%), mild HTG (72, 27.5%), moderate HTG (47, 17.9%), and severe HTG (39, 14.9%) groups. The proportions of AKI were 13.5% (14/104, normal), 13.9% (10/72, mild), 21.3% (10/47, moderate), and 38.5% (15/39, severe), respectively. After establishing SAP model, the levels of serum amylase (P HTG has little adverse impact on disease severity of acute pancreatitis; severe HTG can aggravate kidney injury in the course of acute pancreatitis. ApoCIII-SAP mice have more serious pancreatic damage and kidney injury than WT-SAP mice. Copyright © 2017. Published by Elsevier B.V.

  4. Kidney Cancer

    Science.gov (United States)

    You have two kidneys. They are fist-sized organs on either side of your backbone above your waist. The tubes inside filter and ... blood, taking out waste products and making urine. Kidney cancer forms in the lining of tiny tubes ...

  5. Magnetic Resonance Evaluation of Müllerian Remnants in Mayer-Rokitansky-Küster-Hauser Syndrome

    Energy Technology Data Exchange (ETDEWEB)

    Yoo, Roh-Eul; Cho, Jeong Yeon; Kim, Sang Youn; Kim, Seung Hyup [Department of Radiology, Seoul National University Hospital, Seoul 110-744 (Korea, Republic of)

    2013-07-01

    To analyze magnetic resonance imaging (MRI) findings of Müllerian remnants in young females clinically suspected of Mayer-Rokitansky-Küster-Hauser (MRKH) syndrome in a primary amenorrhea workup. Fifteen young females underwent multiplanar T2- and transverse T1-weighted MRI at either a 1.5T or 3.0T MR imager. Two gynecologic radiologists reached consensus decisions for the evaluation of Müllerian remnants, vagina, ovaries, and associated findings. All cases had bilateral uterine buds in the pelvic cavity, with unilateral cavitation in two cases. The buds had an average long-axis diameter of 2.64 ± 0.65 cm. In all cases, bilateral buds were connected with fibrous band-like structures. In 13 cases, the band-like structures converged at the midline or a paramedian triangular soft tissue lying above the bladder dome. The lower one-third of the vagina was identified in 14 cases. Fourteen cases showed bilateral normal ovaries near the uterine buds. One unilateral pelvic kidney, one unilateral renal agenesis, one mild scoliosis, and three lumbar sacralization cases were found as associated findings. Typical Müllerian remnants in MRKH syndrome consist of bilateral uterine buds connected by the fibrous band-like structures, which converge at the midline triangular soft tissue lying above the bladder dome.

  6. Chronic Kidney Disease and Kidney Failure

    Science.gov (United States)

    ... Education Visitor Information RePORT NIH Fact Sheets Home > Chronic Kidney Disease and Kidney Failure Small Text Medium Text Large Text Chronic Kidney Disease and Kidney Failure YESTERDAY One third of diabetic ...

  7. A 3D View of a Supernova Remnant

    Science.gov (United States)

    Kohler, Susanna

    2017-06-01

    Chandra X-ray observations to measure both the knots proper motion in the plane of the sky and their line-of-sight velocity. These two measurements were then combined to build a full 3D map of the motion of the ejecta.3D hydrodynamical simulations of Tycho, stopped at the current epoch. These show that both initially smooth (top) and initially clumpy (bottom) ejecta models are consistent with the current observations of the morphology and dynamics of Tychos ejecta. [Adapted from Williams et al. 2017]Symmetry and ClumpsWilliams and collaborators found that the knots have total velocities that range from 2400 to 6600 km/s. Unlike the forward shock of the supernova, Tychos ejecta display no asymmetries in their motion which suggests that the explosion itself was symmetric. The more likely explanation is a density gradient in the interstellar medium, which could slow the shock wave on one side of the remnant without yet affecting the motion of the clumps of ejecta.As a final exploration, the authors attempt to address the origin of Tychos clumpiness. The fact that some of Tychos ejecta knots precede its outer edge has raised the question of whether the ejecta started out clumpy, or if they began smooth and only clumped during expansion. Williams and collaborators matched the morphological and dynamical data to simulations, demonstrating that neither scenario can be ruled out at this time.This first 3D map of a Type Ia supernova represents an important step in our ability to understand these stellar explosions. The authors suggest that well be able to expand on this map in the future with additional observations from Chandra, as well as with new data from future X-ray observatories that will be able to detect fainter emission.CitationBrian J. Williams et al 2017 ApJ 842 28. doi:10.3847/1538-4357/aa7384

  8. SN1987A: The Birth of a Supernova Remnant

    Science.gov (United States)

    McCray, Richard

    2003-01-01

    This grant was intended to support the development of theoretical models needed to interpret and understand the observations by the Hubble Space Telescope and the Chandra X-ray telescope of the rapidly developing remnant of Supernova 1987A. In addition, we carried out a few investigations of related topics. The project was spectacularly successful. The models that we developed provide the definitive framework for predicting and interpreting this phenomenon. Following is a list of publications based on our work. Some of these papers include results of both theoretical modeling supported by this project and also analysis of data supported by the Space Telescope Science Institute and the Chandra X-ray Observatory. We first list papers published in refereed journals, then conference proceedings and book chapters, and also an educational web site.

  9. Soft X-ray observations of the supernova remnants HB 3 and 3C 58

    Science.gov (United States)

    Galas, C. M. F.; Tuohy, I. R.; Garmire, G. P.

    1980-01-01

    The HEAO 1 A-2 low energy detectors have discovered soft X-ray emission from a source positionally coincident with the supernova remnant HB 3. The flux in the energy range 0.3-2.2 keV is about 6 x 10 to the -11th ergs per sq cm s. The spectral data are fitted to a hydrogen thermal bremsstrahlung model, and the physical parameters of the supernova remnant are estimated. The age derived is about 21,000 years, and the initial blast energy is about 3.1 x 10 to the 50th ergs. Upper limits to the soft X-ray flux and the luminosity of the supernova remnant 3 C 58 are also derived.

  10. Role of TGF-alpha in the progression of diabetic kidney disease.

    Science.gov (United States)

    Heuer, Josef G; Harlan, Shannon M; Yang, Derek D; Jaqua, Dianna L; Boyles, Jeffrey S; Wilson, Jonathan M; Heinz-Taheny, Kathleen M; Sullivan, John M; Wei, Tao; Qian, Hui-Rong; Witcher, Derrick R; Breyer, Matthew D

    2017-06-01

    Transforming growth factor-alpha (TGFA) has been shown to play a role in experimental chronic kidney disease associated with nephron reduction, while its role in diabetic kidney disease (DKD) is unknown. We show here that intrarenal TGFA mRNA expression, as well as urine and serum TGFA, are increased in human DKD. We used a TGFA neutralizing antibody to determine the role of TGFA in two models of renal disease, the remnant surgical reduction model and the uninephrectomized (uniNx) db/db DKD model. In addition, the contribution of TGFA to DKD progression was examined using an adeno-associated virus approach to increase circulating TGFA in experimental DKD. In vivo blockade of TGFA attenuated kidney disease progression in both nondiabetic 129S6 nephron reduction and Type 2 diabetic uniNx db/db models, whereas overexpression of TGFA in uniNx db/db model accelerated renal disease. Therapeutic activity of the TGFA antibody was enhanced with renin angiotensin system inhibition with further improvement in renal parameters. These findings suggest a pathologic contribution of TGFA in DKD and support the possibility that therapeutic administration of neutralizing antibodies could provide a novel treatment for the disease. Copyright © 2017 the American Physiological Society.

  11. Inhibiting the HSP90 chaperone slows cyst growth in a mouse model of autosomal dominant polycystic kidney disease

    OpenAIRE

    Seeger-Nukpezah, Tamina; Proia, David A.; Egleston, Brian L.; Nikonova, Anna S; Kent, Tatiana; Cai, Kathy Q.; Hensley, Harvey H.; Ying, Weiwen; Chimmanamada, Dinesh; Serebriiskii, Ilya G.; Golemis, Erica A.

    2013-01-01

    Autosomal dominant polycystic kidney disease (ADPKD) is a progressive genetic syndrome with an incidence of 1:500 in the population, arising from inherited mutations in the genes for polycystic kidney disease 1 (PKD1) or polycystic kidney disease 2 (PKD2). Typical onset is in middle age, with gradual replacement of renal tissue with thousands of fluid-filled cysts, resulting in end-stage renal disease requiring dialysis or kidney transplantation. There currently are no approved therapies to s...

  12. Pain Medicines and Kidney Damage

    Science.gov (United States)

    ... Damage Related Topics Section Navigation Kidney Disease Acquired Cystic Kidney Disease Amyloidosis & Kidney Disease Chronic Kidney Disease (CKD) What ... Eating, Diet, & Nutrition for PKD Race, Ethnicity, & Kidney Disease Renal Artery ... Kidney Cysts Solitary Kidney Your Kidneys & How They Work Pain ...

  13. The Simulation of the Influence of Water Remnants on a Hot Rolled Plate after Cooling

    Directory of Open Access Journals (Sweden)

    Radek Zahradník

    2012-01-01

    Full Text Available In situations when a sheet metal plate of large dimensions is rolled, water remnants from cooling can be observed on the upper side of the plate. This paper focuses on deformations of a hot rolled sheet metal plate that are caused by water remnants after cooling. A transient finite element simulation was used to describe shape deformations of the cross profile of a metal sheet. The finite element model is fully parametric for easy simulation of multiple cases. The results from previous work were used for the boundary conditions.

  14. Re-examination of the Expected gamma-ray emission of supernova remnant SN 1987A

    OpenAIRE

    Berezhko, E; Ksenofontov, L.; Völk, H.

    2015-01-01

    A nonlinear kinetic theory, combining cosmic-ray (CR) acceleration in supernova remnants (SNRs) with their gas dynamics, is used to re-examine the nonthermal properties of the remnant of SN 1987A for an extended evolutionary period of 5-50 yr. This spherically symmetric model is approximately applied to the different features of the SNR which consist of (i) a blue supergiant wind and bubble, and (ii) of the swept-up red supergiant (RSG) wind structures in the form of an H II region, an equato...

  15. E-Learning Model in Chronic Kidney Disease Management: a Controlled Clinical Trial.

    Science.gov (United States)

    Barahimi, Hamid; Zolfaghari, Mitra; Abolhassani, Farid; Rahimi Foroushani, Abass; Mohammadi, Aeen; Rajaee, Farahnaz

    2017-07-01

    Chronic kidney disease (CKD) is a challenging health problem. The present study examined impact of self-care education through e-learning on improving kidney function among individuals with CKD. The studied population consisted of CKD patients receiving care at 10 centers for treating noncommunicable diseases in Tehran. Three centers were randomly selected and 39 patients with a glomerular filtration rate (GFR) less than 60 mL/min/1.73 m2, minimum education of grade 9, minimum of 2 years of referrals, and computer literacy of the individual or a first-degree relative were included in the study, while 92 patients were assigned into the control group. Changes in GFR were compared after 6 months following an e-learning program for the patients in the intervention group. The mean change in GFR was 7.5 ± 8.9 mL/min/1.73 m2 for the intervention group after the e-learning intervention, while this was -2.3 ± 8.5 mL/min/1.73 m2. The two groups were also significantly different in terms of age, marital status, education level, mean arterial pressure, and serum high-density lipoprotein level, and therefore, multivariable comparison of GFR was made incorporating these factor into the analysis and showed a significant improvement of GFR in the intervention group. According to the results of this study, effects of the e-learning educational intervention on improvement in kidney function and CKD treatment were established.

  16. Kidney Disease Basics

    Science.gov (United States)

    ... Heart Disease Mineral & Bone Disorder What Is Chronic Kidney Disease? Chronic kidney disease (CKD) means your kidneys ... work, be active, and enjoy life. Will my kidneys get better? Kidney disease is often “progressive”, which ...

  17. Kidney (Renal) Failure

    Science.gov (United States)

    ... How is kidney failure treated? What is kidney (renal) failure? The kidneys are designed to maintain proper fluid ... marrow and strengthen the bones. The term kidney (renal) failure describes a situation in which the kidneys have ...

  18. Chronic Kidney Disease (CKD)

    Science.gov (United States)

    ... store Donate Now Give Monthly Give In Honor Chronic kidney disease (CKD) www.kidneyfund.org > Kidney Disease > Chronic Kidney ... treated? Kidney-friendly diet for CKD What causes chronic kidney disease (CKD)? Anyone can get CKD. Some people are ...

  19. VHE Gamma-ray Supernova Remnants

    Energy Technology Data Exchange (ETDEWEB)

    Funk, Stefan; /KIPAC, Menlo Park

    2007-01-22

    Increasing observational evidence gathered especially in X-rays and {gamma}-rays during the course of the last few years support the notion that Supernova remnants (SNRs) are Galactic particle accelerators up to energies close to the ''knee'' in the energy spectrum of Cosmic rays. This review summarizes the current status of {gamma}-ray observations of SNRs. Shell-type as well as plerionic type SNRs are addressed and prospect for observations of these two source classes with the upcoming GLAST satellite in the energy regime above 100 MeV are given.

  20. Supernova Remnants with Fermi Large Area Telescope

    Directory of Open Access Journals (Sweden)

    Caragiulo M.

    2017-01-01

    Full Text Available The Large Area Telescope (LAT, on-board the Fermi satellite, proved to be, after 8 years of data taking, an excellent instrument to detect and observe Supernova Remnants (SNRs in a range of energies running from few hundred MeV up to few hundred GeV. It provides essential information on physical processes that occur at the source, involving both accelerated leptons and hadrons, in order to understand the mechanisms responsible for the primary Cosmic Ray (CR acceleration. We show the latest results in the observation of Galactic SNRs by Fermi-LAT.

  1. Transport of magnetic turbulence in supernova remnants

    OpenAIRE

    Brose, R.; Telezhinsky, Igor; Pohl, M.

    2016-01-01

    Context. Supernova remnants are known as sources of galactic cosmic rays for their non-thermal emission of radio waves, X-rays, and gamma-rays. However, the observed soft broken power-law spectra are hard to reproduce within standard acceleration theory based on the assumption of Bohm diffusion and steady-state calculations. Aims. We point out that a time-dependent treatment of the acceleration process together with a self-consistent treatment of the scattering turbulence amplification is nec...

  2. Numerical Simulations of Supernova Remnant Evolution in a Cloudy Interstellar Medium

    Energy Technology Data Exchange (ETDEWEB)

    Slavin, Jonathan D.; Smith, Randall K.; Foster, Adam; Winter, Henry D.; Raymond, John C.; Slane, Patrick O. [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States); Yamaguchi, Hiroya, E-mail: jslavin@cfa.harvard.edu [NASA Goddard Space Flight Center, Code 662, Greenbelt, MD 20771 (United States)

    2017-09-01

    The mixed morphology class of supernova remnants has centrally peaked X-ray emission along with a shell-like morphology in radio emission. White and Long proposed that these remnants are evolving in a cloudy medium wherein the clouds are evaporated via thermal conduction once being overrun by the expanding shock. Their analytical model made detailed predictions regarding temperature, density, and emission profiles as well as shock evolution. We present numerical hydrodynamical models in 2D and 3D including thermal conduction, testing the White and Long model and presenting results for the evolution and emission from remnants evolving in a cloudy medium. We find that, while certain general results of the White and Long model hold, such as the way the remnants expand and the flattening of the X-ray surface brightness distribution, in detail there are substantial differences. In particular we find that the X-ray luminosity is dominated by emission from shocked cloud gas early on, leading to a bright peak, which then declines and flattens as evaporation becomes more important. In addition, the effects of thermal conduction on the intercloud gas, which is not included in the White and Long model, are important and lead to further flattening of the X-ray brightness profile as well as lower X-ray emission temperatures.

  3. Energy Dependence of Synchrotron X-Ray Rims in Tycho's Supernova Remnant

    Science.gov (United States)

    Tran, Aaron; Williams, Brian J.; Petre, Robert; Ressler, Sean M.; Reynolds, Stephen P.

    2015-01-01

    Several young supernova remnants exhibit thin X-ray bright rims of synchrotron radiation at their forward shocks. Thin rims require strong magnetic field amplification beyond simple shock compression if rim widths are only limited by electron energy losses. But, magnetic field damping behind the shock could produce similarly thin rims with less extreme field amplification. Variation of rim width with energy may thus discriminate between competing influences on rim widths. We measured rim widths around Tycho's supernova remnant in 5 energy bands using an archival 750 ks Chandra observation. Rims narrow with increasing energy and are well described by either loss-limited or damped scenarios, so X-ray rim width-energy dependence does not uniquely specify a model. But, radio counterparts to thin rims are not loss-limited and better reflect magnetic field structure. Joint radio and X-ray modeling favors magnetic damping in Tycho's SNR with damping lengths approximately 1-5% of remnant radius and magnetic field strengths approximately 50-400 micron G assuming Bohm diffusion. X-ray rim widths are approximately 1% of remnant radius, somewhat smaller than inferred damping lengths. Electron energy losses are important in all models of X-ray rims, suggesting that the distinction between loss-limited and damped models is blurred in soft X-rays. All loss-limited and damping models require magnetic fields approximately greater than 20 micron G, arming the necessity of magnetic field amplification beyond simple compression.

  4. Numerical Simulations of Supernova Remnant Evolution in a Cloudy Interstellar Medium

    Science.gov (United States)

    Slavin, Jonathan D.; Smith, Randall K.; Foster, Adam; Winter, Henry D.; Raymond, John C.; Slane, Patrick O.; Yamaguchi, Hiroya

    2017-09-01

    The mixed morphology class of supernova remnants has centrally peaked X-ray emission along with a shell-like morphology in radio emission. White & Long proposed that these remnants are evolving in a cloudy medium wherein the clouds are evaporated via thermal conduction once being overrun by the expanding shock. Their analytical model made detailed predictions regarding temperature, density, and emission profiles as well as shock evolution. We present numerical hydrodynamical models in 2D and 3D including thermal conduction, testing the White & Long model and presenting results for the evolution and emission from remnants evolving in a cloudy medium. We find that, while certain general results of the White & Long model hold, such as the way the remnants expand and the flattening of the X-ray surface brightness distribution, in detail there are substantial differences. In particular we find that the X-ray luminosity is dominated by emission from shocked cloud gas early on, leading to a bright peak, which then declines and flattens as evaporation becomes more important. In addition, the effects of thermal conduction on the intercloud gas, which is not included in the White & Long model, are important and lead to further flattening of the X-ray brightness profile as well as lower X-ray emission temperatures.

  5. Structure of stable binary neutron star merger remnants: A case study

    Science.gov (United States)

    Kastaun, W.; Ciolfi, R.; Giacomazzo, B.

    2016-08-01

    In this work, we study the merger of two neutron stars with a gravitational mass of 1.4 M⊙ each, employing the Shen-Horowitz-Teige equation of state. This equation of state is a corner case, allowing the formation of a stable neutron star with the given total baryonic mass of 3.03 M⊙. We investigate in unprecedented detail the structure of the remnant, in particular the mass distribution, the thermal structure, and the rotation profile. We also compute fluid trajectories both inside the remnant and those relevant for the formation of the disk. We find a peanut-shaped fluid flow inside the remnant following a strong m =2 perturbation. Moreover, the flow is locally compressive, causing the appearance of dynamic hot spots. Further, we introduce new diagnostic measures that are easy to implement in numeric simulations and that allow one to quantify mass and compactness of merger remnants in a well-defined way. As in previous studies of supra- and hypermassive stars, we find a remnant with a slowly rotating core and an outer envelope rotating at nearly Keplerian velocity. We compute a Tolman-Oppenheimer-Volkoff star model which agrees well with that of the remnant in the core, while the latter possesses extensive outer layers rotating close to Kepler velocity. Finally, we extract the gravitational wave signal and discuss the detectability with modern observatories. This study has implications for the interpretation of gravitational wave detections from the postmerger phase and is relevant for short gamma-ray burst models.

  6. Remnant cholesterol as a cause of ischemic heart disease

    DEFF Research Database (Denmark)

    Varbo, Anette; Benn, Marianne; Nordestgaard, Børge G

    2014-01-01

    This review focuses on remnant cholesterol as a causal risk factor for ischemic heart disease (IHD), on its definition, measurement, atherogenicity, and levels in high risk patient groups; in addition, present and future pharmacological approaches to lowering remnant cholesterol levels...... are considered. Observational studies show association between elevated levels of remnant cholesterol and increased risk of cardiovascular disease, even when remnant cholesterol levels are defined, measured, or calculated in different ways. In-vitro and animal studies also support the contention that elevated...... levels of remnant cholesterol may cause atherosclerosis same way as elevated levels of low-density lipoprotein (LDL) cholesterol, by cholesterol accumulation in the arterial wall. Genetic studies of variants associated with elevated remnant cholesterol levels show that an increment of 1mmol/L (39mg...

  7. Unilateral Renal Ischemia-Reperfusion as a Robust Model for Acute to Chronic Kidney Injury in Mice.

    Directory of Open Access Journals (Sweden)

    Nathalie Le Clef

    Full Text Available Acute kidney injury (AKI is an underestimated, yet important risk factor for development of chronic kidney disease (CKD. Even after initial total recovery of renal function, some patients develop progressive and persistent deterioration of renal function and these patients are more likely to progress to end-stage renal disease (ESRD. Animal models are indispensable for unravelling the mechanisms underlying this progression towards CKD and ESRD and for the development of new therapeutic strategies in its prevention or treatment. Ischemia (i.e. hypoperfusion after surgery, bleeding, dehydration, shock, or sepsis is a major aetiology in human AKI, yet unilateral ischemia-reperfusion is a rarely used animal model for research on CKD and fibrosis. Here, we demonstrate in C57Bl/6J mice, by both histology and gene expression, that unilateral ischemia-reperfusion without contralateral nephrectomy is a very robust model to study the progression from acute renal injury to long-term tubulo-interstitial fibrosis, i.e. the histopathological hallmark of CKD. Furthermore, we report that the extent of renal fibrosis, in terms of Col I, TGFβ, CCN2 and CCN3 expression and collagen I immunostaining, increases with increasing body temperature during ischemia and ischemia-time. Thus, varying these two main determinants of ischemic injury allows tuning the extent of the long-term fibrotic outcome in this model. Finally, in order to cover the whole practical finesse of ischemia-reperfusion and allow model and data transfer, we provide a referenced overview on crucial technical issues (incl. anaesthesia, analgesia, and pre- and post-operative care with the specific aim of putting starters in the right direction of implementing ischemia in their research and stimulate them, as well as the community, to have a critical view on ischemic literature data.

  8. Raloxifene improves skeletal properties in an animal model of cystic chronic kidney disease.

    Science.gov (United States)

    Newman, Christopher L; Creecy, Amy; Granke, Mathilde; Nyman, Jeffry S; Tian, Nannan; Hammond, Max A; Wallace, Joseph M; Brown, Drew M; Chen, Neal; Moe, Sharon M; Allen, Matthew R

    2016-01-01

    Patients with chronic kidney disease (CKD) have an increased risk of fracture. Raloxifene is a mild antiresorptive agent that reduces fracture risk in the general population. Here we assessed the impact of raloxifene on the skeletal properties of animals with progressive CKD. Male Cy/+ rats that develop autosomal dominant cystic kidney disease were treated with either vehicle or raloxifene for five weeks. They were assessed for changes in mineral metabolism and skeletal parameters (microCT, histology, whole-bone mechanics, and material properties). Their normal littermates served as controls. Animals with CKD had significantly higher parathyroid hormone levels compared with normal controls, as well as inferior structural and mechanical skeletal properties. Raloxifene treatment resulted in lower bone remodeling rates and higher cancellous bone volume in the rats with CKD. Although it had little effect on cortical bone geometry, it resulted in higher energy to fracture and modulus of toughness values than vehicle-treated rats with CKD, achieving levels equivalent to normal controls. Animals treated with raloxifene had superior tissue-level mechanical properties as assessed by nanoindentation, and higher collagen D-periodic spacing as assessed by atomic force microscopy. Thus, raloxifene can positively impact whole-bone mechanical properties in CKD through its impact on skeletal material properties. Copyright © 2015 International Society of Nephrology. Published by Elsevier Inc. All rights reserved.

  9. Global Gene Expression Profiling in PPAR-γ Agonist-Treated Kidneys in an Orthologous Rat Model of Human Autosomal Recessive Polycystic Kidney Disease

    Directory of Open Access Journals (Sweden)

    Daisuke Yoshihara

    2012-01-01

    Full Text Available Kidneys are enlarged by aberrant proliferation of tubule epithelial cells leading to the formation of numerous cysts, nephron loss, and interstitial fibrosis in polycystic kidney disease (PKD. Pioglitazone (PIO, a PPAR-γ agonist, decreased cell proliferation, interstitial fibrosis, and inflammation, and ameliorated PKD progression in PCK rats (Am. J. Physiol.-Renal, 2011. To explore genetic mechanisms involved, changes in global gene expression were analyzed. By Gene Set Enrichment Analysis of 30655 genes, 13 of the top 20 downregulated gene ontology biological process gene sets and six of the top 20 curated gene set canonical pathways identified to be downregulated by PIOtreatment were related to cell cycle and proliferation, including EGF, PDGF and JNK pathways. Their relevant pathways were identified using the Kyoto Encyclopedia of Gene and Genomes database. Stearoyl-coenzyme A desaturase 1 is a key enzyme in fatty acid metabolism found in the top 5 genes downregulated by PIO treatment. Immunohistochemical analysis revealed that the gene product of this enzyme was highly expressed in PCK kidneys and decreased by PIO. These data show that PIO alters the expression of genes involved in cell cycle progression, cell proliferation, and fatty acid metabolism.

  10. Ultrasound-guided radiofrequency thermal ablation of normal kidney in a rabbit model: correlation with CT and histopathology

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Sang Won; Lee, Jeong Min; Kin, Chong Soo; Lee, Sang Hun [College of Medicine, Chonbuk National Univ., Chonju (Korea, Republic of)

    2002-01-01

    To assess the feasibility and safety of using a cooled-tip electrode to perform percutaneous radiofrequency ablation of kidney tissue in rabbits, and to evaluate the ability of CT to reveal the appearance and extent of tissue necrosis during follow-up after ablation. Using ultrasound guidance, a 17-G cooled-tip electrode was inserted into the right lower portion of the kidney in 26 New Zealand White rabbits. Radiofrequency was applied for 2 mins, and biphasic helical CT scanning was used to assess tissue destruction and the presence or absence of complications immediately after the procedure and at 24 hrs, 2 and 3 days, and 1,2,3,4,5,6 and 7 weeks. The study had three phases: acute (immediately killed : N=10); subacute (killed at 24 hrs (n=3), 2 days (n=3), 3 days (n=1) : N=7); chronic (killed at 1 week (n=4), 2 weeks (n=2), 4 weeks (n=1), 7 weeks (n=1): N=8). After the animals were killed, their kidneys were histopathologically examined and the radiologic and pathologic findings of lesion size and configuration were correlated. In each instance, ultrasound-guided radiofrequency ablations of the lower pole of the kidney were technically successful. Contrast-enhanced biphasic helical CT revealed regions of hypoattenuation devoid of parenchymal enhancement, and these correlated closely with true pathologic lesion size (r=0.884; p>0.05). In subacute and chronic models, CT scanning revealed gradual spontaneous resorption of the ablated lesion and the presence of perilesional calcification. Histopathologically, in the acute phase the ablated lesion showed coagulative necrosis and infiltration of inflammatory cells, and in the chronic phase there was clear cut necrosis of glomeruli, tubules and renal interstitium, with diminishing inflammatory response and peripheral fibrotic tissue formation. Ultrasound-guided renal radiofrequency ablation is technically feasible and safe. In addition, the avascular lesion measured at contrast-enhanced helical CT closely correlated with

  11. Soy Protein Alleviates Hypertension and Fish Oil Improves Diastolic Heart Function in the Han:SPRD-Cy Rat Model of Cystic Kidney Disease.

    Science.gov (United States)

    Ibrahim, Naser H M; Thandapilly, Sijo J; Jia, Yong; Netticadan, Thomas; Aukema, Harold

    2016-05-01

    Abnormalities in cardiac structure and function are very common among people with chronic kidney disease, in whom cardiovascular disease is the major cause of death. Dietary soy protein and fish oil reduce kidney disease progression in the Han:SPRD-Cy model of cystic renal disease. However, the effects of these dietary interventions in preventing alterations in cardiac structure and function due to kidney disease (reno-cardiac syndrome) in a cystic kidney disease model are not known. Therefore, weanling Han:SPRD-Cy diseased (Cy/+) and normal (+/+) rats were given diets containing either casein or soy protein, and either soy or fish oil in a three-way design for 8 weeks. Diseased rats had larger hearts, augmented left ventricular mass, and higher systolic and mean arterial blood pressure compared to the normal rats. Assessment of cardiac function using two-dimensional guided M-mode and pulse-wave Doppler echocardiography revealed that isovolumic relaxation time was prolonged in the diseased compared to normal rats, reflecting a diastolic heart dysfunction, and fish oil prevented this elevation. Soy protein resulted in a small improvement in systolic and mean arterial pressure but did not improve diastolic heart function, while fish oil prevented diastolic heart dysfunction in this model of cystic kidney disease.

  12. Towards quantitation of the effects of renal impairment and probenecid inhibition on kidney uptake and efflux transporters, using physiologically based pharmacokinetic modelling and simulations.

    Science.gov (United States)

    Hsu, Vicky; de L T Vieira, Manuela; Zhao, Ping; Zhang, Lei; Zheng, Jenny Huimin; Nordmark, Anna; Berglund, Eva Gil; Giacomini, Kathleen M; Huang, Shiew-Mei

    2014-03-01

    The kidney is a major drug-eliminating organ. Renal impairment or concomitant use of transporter inhibitors may decrease active secretion and increase exposure to a drug that is a substrate of kidney secretory transporters. However, prediction of the effects of patient factors on kidney transporters remains challenging because of the multiplicity of transporters and the lack of understanding of their abundance and specificity. The objective of this study was to use physiologically based pharmacokinetic (PBPK) modelling to evaluate the effects of patient factors on kidney transporters. Models for three renally cleared drugs (oseltamivir carboxylate, cidofovir and cefuroxime) were developed using a general PBPK platform, with the contributions of net basolateral uptake transport (T up,b) and apical efflux transport (T eff,a) being specifically defined. We demonstrated the practical use of PBPK models to: (1) define transporter-mediated renal secretion, using plasma and urine data; (2) inform a change in the system-dependent parameter (≥10-fold reduction in the functional 'proximal tubule cells per gram kidney') in severe renal impairment that is responsible for the decreased secretory transport activities of test drugs; (3) derive an in vivo, plasma unbound inhibition constant of T up,b by probenecid (≤1 μM), based on observed drug interaction data; and (4) suggest a plausible mechanism of probenecid preferentially inhibiting T up,b in order to alleviate cidofovir-induced nephrotoxicity.

  13. Kidney Problems

    Science.gov (United States)

    ... High Blood Pressure Nutrition Join our e-newsletter! Aging & Health A to Z Kidney Problems Basic Facts & ... build-up of waste products, and other serious consequences in later years. Doses of medications must also ...

  14. Kidney Dysplasia

    Science.gov (United States)

    ... multicystic dysplastic kidney: does initial size matter? Pediatric Nephrology . 2012;27(8):1335–1340. Clinical Trials The ... all members of the American Society of Pediatric Nephrology Clinical Affairs Committee; Deepa H. Chand, M.D., ...

  15. Kidney removal

    Science.gov (United States)

    ... the lungs Breathing problems Infection, including in the surgical wound, lungs ( pneumonia ), bladder, or kidney Blood loss Heart ... work as well for awhile Hernia of your surgical wound Before the Procedure Always tell your health care ...

  16. Bionic kidney.

    Science.gov (United States)

    Bonomini, V

    2003-05-01

    Bionic Kidney is a project still in progress which aims at replacing all renal functions, which has been carried out in an ideal attempt to improve the overall results of Renal Replacement Therapy. It contains all the requisites for a complete rehabilitation from Uremia. As a futuristic mini-device implanted in the body, it should be a reliable support to Transplantation performance, considering the scarcity of kidney donors.

  17. Restoration of Haemoglobin Level Using Hydrodynamic Gene Therapy with Erythropoietin Does Not Alleviate the Disease Progression in an Anaemic Mouse Model for TGFβ1-Induced Chronic Kidney Disease

    DEFF Research Database (Denmark)

    Pedersen, Lea Hougaard; Wogensen, Lise; Marcussen, N.

    2015-01-01

    expressed in non-haematopoietic tissue and today, Epo is recognised as a cytokine with many pleiotropic effects. We hypothesize that hydrodynamic gene therapy with Epo can restore haemoglobin levels in anaemic transgenic mice and that this will attenuate the extracellular matrix accumulation in the kidneys....... The experiment is conducted by hydrodynamic gene transfer of a plasmid encoding murine Epo in a transgenic mouse model that overexpresses TGF-β1 locally in the kidneys. This model develops anaemia due to chronic kidney disease characterised by thickening of the glomerular basement membrane, deposition...... of mesangial matrix and mild interstitial fibrosis. A group of age matched wildtype littermates are treated accordingly. After a single hydrodynamic administration of plasmid DNA containing murine EPO gene, sustained high haemoglobin levels are observed in both transgenic and wildtype mice from 7.5 ± 0.6 mmol...

  18. Fetal myocardium in the kidney capsule: an in vivo model of repopulation of myocytes by bone marrow cells.

    Directory of Open Access Journals (Sweden)

    Eric Y Zhang

    Full Text Available Debate surrounds the question of whether the heart is a post-mitotic organ in part due to the lack of an in vivo model in which myocytes are able to actively regenerate. The current study describes the first such mouse model--a fetal myocardial environment grafted into the adult kidney capsule. Here it is used to test whether cells descended from bone marrow can regenerate cardiac myocytes. One week after receiving the fetal heart grafts, recipients were lethally irradiated and transplanted with marrow from green fluorescent protein (GFP-expressing C57Bl/6J (B6 donors using normal B6 recipients and fetal donors. Levels of myocyte regeneration from GFP marrow within both fetal myocardium and adult hearts of recipients were evaluated histologically. Fetal myocardium transplants had rich neovascularization and beat regularly after 2 weeks, continuing at checkpoints of 1, 2, 4, 6, 8 and12 months after transplantation. At each time point, GFP-expressing rod-shaped myocytes were found in the fetal myocardium, but only a few were found in the adult hearts. The average count of repopulated myocardium with green rod-shaped myocytes was 996.8 cells per gram of fetal myocardial tissue, and 28.7 cells per adult heart tissue, representing a thirty-five fold increase in fetal myocardium compared to the adult heart at 12 months (when numbers of green rod-shaped myocytes were normalized to per gram of myocardial tissue. Thus, bone marrow cells can differentiate to myocytes in the fetal myocardial environment. The novel in vivo model of fetal myocardium in the kidney capsule appears to be valuable for testing repopulating abilities of potential cardiac progenitors.

  19. Ectopic Kidney

    Directory of Open Access Journals (Sweden)

    John Costumbrado

    2017-07-01

    Full Text Available History of present illness: A 50-year-old male with no past medical history presented to the emergency department with a chief complaint of right flank pain after stretching. His vital signs were within normal limits and physical exam was significant for tenderness to palpation over the right lateral chest wall. Chest X-ray was unremarkable. Due to the patient’s uncertainty of the exact mechanism of injury, additional trauma could not be ruled out and a bedside focused assessment with sonography in trauma (FAST scan was performed, which was negative for free fluid, but notable for an absence of a right kidney. The patient was sent for a computed tomography (CT abdomen/pelvis to evaluate the etiology of symptoms and to address the absence of visualized kidney on ultrasound. Significant findings: CT of the abdomen and pelvis revealed a normal left kidney and an ectopic, malrotated right kidney located in the pelvis (see white arrow. Discussion: Renal ectopia is described as a malposition of the kidney, due to faulty migration from the fetal pelvis during early embryonic development. Evidence suggests an incidence ranging from 1:900 to 1:12,000.1-3 While most cases are asymptomatic and do not require intervention, complications include vesicoureteral reflux, urinary tract infections, hydronephrosis, and renal calculi.4,5 Ultrasonography is indicated for the evaluation of free fluid in the abdomen and pelvis in the setting of trauma. In this case, the right upper quadrant ultrasound was negative for both free fluid and a right kidney, even with appropriate repositioning techniques.7 The absence of the right kidney on ultrasound in the setting of pain prompted the decision for further diagnostic imaging, which revealed an ectopic right kidney. The absence of a kidney on FAST exam should prompt the clinician to consider surgical (eg, nephrectomy or congenital (eg, renal ectopy explanations. Furthermore, pathophysiologic processes (eg, pyelonephritis

  20. Energy spectra of electrons and positrons produced in supernova remnants

    Science.gov (United States)

    Berezhko, E. G.; Ksenofontov, L. T.

    2013-02-01

    We study the production of cosmic rays (CRs) in supernova remnants (SNRs), including the production of electron and positron CR components. This combines for the first time nuclear collisions inside CR sources and in the diffuse interstellar medium leading to the creation of electrons and positrons, as well as their reacceleration, with the injection and subsequent acceleration of suprathermal protons and electrons from the postshock thermal pool. Selfconsistent CR spectra are calculated on the basis of the nonlinear kinetic model. It is shown that reacceleration of positrons created in SNR and ISM produces a considerable effect at energies above 10 GeV, making its energy spectrum substantially flatter than the spectrum created in ISM. Calculated electron and positron spectra are in the satisfactory agreement with the existing measurements.

  1. Beneficial Effects of Caloric Restriction on Chronic Kidney Disease in Rodent Models: A Meta-Analysis and Systematic Review.

    Science.gov (United States)

    Xu, Xiao-Meng; Cai, Guang-Yan; Bu, Ru; Wang, Wen-Juan; Bai, Xue-Yuan; Sun, Xue-Feng; Chen, Xiang-Mei

    2015-01-01

    Numerous studies have demonstrated the life-extending effect of caloric restriction. It is generally accepted that caloric restriction has health benefits, such as prolonging lifespan and delaying the onset and progression of CKD in various species, especially in rodent models. Although many studies have tested the efficacy of caloric restriction, no complete quantitative analysis of the potential beneficial effects of reducing caloric intake on the development and progression of CKD has been published. All studies regarding the relationship between caloric restriction and chronic kidney diseases were searched in electronic databases, including PubMed/MEDLINE, EMBASE, Science Citation Index (SCI), OVID evidence-based medicine, Chinese Bio-medical Literature and Chinese science and technology periodicals (CNKI, VIP, and Wan Fang). The pooled odds ratios (OR) and 95% confidence intervals (95% CI) were calculated by using fixed- or random-effects models. The data from 27 of all the studies mentioned above was used in the Meta analysis. Through the meta-analysis, we found that the parameter of blood urea nitrogen, serum creatinine and urinary protein levels of the AL group was significant higher than that of the CR group, which are 4.11 mg/dl, 0.08mg/dl and 33.20mg/kg/24h, respectively. The incidence of the nephropathy in the caloric restriction (CR) group was significantly lower than that in the ad libitum-fed (AL) group. We further introduced the subgroup analysis and found that the effect of caloric restriction on the occurrence of kidney disease was only significant with prolonged intervention; the beneficial effects of CR on the 60%-caloric-restriction group were greater than on the less-than-60%-caloric-restriction group, and caloric restriction did not show obvious protective effects in genetically modified strains. Moreover, survival rate of the caloric restriction group is much higher than that of the ad libitum-fed (AL) group. Our findings demonstrate for the

  2. Beneficial Effects of Caloric Restriction on Chronic Kidney Disease in Rodent Models: A Meta-Analysis and Systematic Review.

    Directory of Open Access Journals (Sweden)

    Xiao-Meng Xu

    Full Text Available Numerous studies have demonstrated the life-extending effect of caloric restriction. It is generally accepted that caloric restriction has health benefits, such as prolonging lifespan and delaying the onset and progression of CKD in various species, especially in rodent models. Although many studies have tested the efficacy of caloric restriction, no complete quantitative analysis of the potential beneficial effects of reducing caloric intake on the development and progression of CKD has been published.All studies regarding the relationship between caloric restriction and chronic kidney diseases were searched in electronic databases, including PubMed/MEDLINE, EMBASE, Science Citation Index (SCI, OVID evidence-based medicine, Chinese Bio-medical Literature and Chinese science and technology periodicals (CNKI, VIP, and Wan Fang. The pooled odds ratios (OR and 95% confidence intervals (95% CI were calculated by using fixed- or random-effects models.The data from 27 of all the studies mentioned above was used in the Meta analysis. Through the meta-analysis, we found that the parameter of blood urea nitrogen, serum creatinine and urinary protein levels of the AL group was significant higher than that of the CR group, which are 4.11 mg/dl, 0.08mg/dl and 33.20mg/kg/24h, respectively. The incidence of the nephropathy in the caloric restriction (CR group was significantly lower than that in the ad libitum-fed (AL group. We further introduced the subgroup analysis and found that the effect of caloric restriction on the occurrence of kidney disease was only significant with prolonged intervention; the beneficial effects of CR on the 60%-caloric-restriction group were greater than on the less-than-60%-caloric-restriction group, and caloric restriction did not show obvious protective effects in genetically modified strains. Moreover, survival rate of the caloric restriction group is much higher than that of the ad libitum-fed (AL group.Our findings

  3. Supernova Remnants as the Sources of Galactic Cosmic Rays

    NARCIS (Netherlands)

    Vink, J.

    2013-01-01

    The origin of cosmic rays holds still manymysteries hundred years after they were first discovered. Supernova remnants have for long been the most likely sources of Galactic cosmic rays. I discuss here some recent evidence that suggests that supernova remnants can indeed efficiently accelerate

  4. Observational Signatures of Particle Acceleration in Supernova Remnants

    NARCIS (Netherlands)

    Helder, E.A.; Vink, J.; Bykov, A.M.; Ohira, Y.; Raymond, J.C.; Terrier, R.

    2012-01-01

    We evaluate the current status of supernova remnants as the sources of Galactic cosmic rays. We summarize observations of supernova remnants, covering the whole electromagnetic spectrum and describe what these observations tell us about the acceleration processes by high Mach number shock fronts. We

  5. Supernova remnants and the origin of cosmic rays

    NARCIS (Netherlands)

    Vink, J.

    2014-01-01

    Supernova remnants have long been considered to be the dominant sources of Galactic cosmic rays. For a long time the prime evidence consisted of radio synchrotron radiation from supernova remnants, indicating the presence of electrons with energies of several GeV. However, in order to explain the

  6. Relating Eye Activity Measures to Human Controller Remnant Characteristics

    NARCIS (Netherlands)

    Popovici, A; Zaal, P.M.T.; Pool, D.M.; Mulder, M.; Sawaragi, T

    2016-01-01

    This study attempts to partially explain the characteristics of the human perceptual remnant, following Levison’s representation of the remnant as an equivalent observation noise. Eye activity parameters are recorded using an eye tracker in two compensatory tracking tasks in which the visual

  7. Semiclassical geons as solitonic black hole remnants

    Energy Technology Data Exchange (ETDEWEB)

    Lobo, Francisco S.N. [Centro de Astronomia e Astrofísica da Universidade de Lisboa, Campo Grande, Ed. C8 1749-016 Lisboa (Portugal); Olmo, Gonzalo J.; Rubiera-Garcia, D., E-mail: flobo@cii.fc.ul.pt, E-mail: gonzalo.olmo@csic.es, E-mail: drubiera@fisica.ufpb.br2 [Departamento de Física Teórica and IFIC, Centro Mixto Universidad de Valencia - CSIC. Universidad de Valencia, Burjassot-46100, Valencia (Spain)

    2013-07-01

    We find that the end state of black hole evaporation could be represented by non-singular and without event horizon stable solitonic remnants with masses of the order the Planck scale and up to ∼ 16 units of charge. Though these objects are locally indistinguishable from spherically symmetric, massive electric (or magnetic) charges, they turn out to be sourceless geons containing a wormhole generated by the electromagnetic field. Our results are obtained by interpreting semiclassical corrections to Einstein's theory in the first-order (Palatini) formalism, which yields second-order equations and avoids the instabilities of the usual (metric) formulation of quadratic gravity. We also discuss the potential relevance of these solutions for primordial black holes and the dark matter problem.

  8. Urachal remnant carcinoma - a rare entity

    Directory of Open Access Journals (Sweden)

    Vanesha Naidu

    2013-06-01

    Full Text Available Primary malignancy of the urachal remnant is a rare neoplasm that accounts for less than 0.01% of all adult cancers, with an estimated annual incidence of 1:5 million. The tumour carries a grave prognosis that attests to its highly aggressive nature. Owing to its extra-peritoneal location, the tumour runs a relatively silent clinical course until late presentation, when most patients display extensive local invasion and metastatic spread. In this report, we highlight a case of primary malignancy of the urachus that on initial clinical evaluation masqueraded as a Sister Mary Joseph’s nodule. Characteristic imaging features, however, proved decisive in establishing the diagnosis of a urachal carcinoma.

  9. Detecting supernova remnants in external galaxies

    Science.gov (United States)

    Dickel, J. R.; Dodorico, S.

    1985-01-01

    Identification of supernova remnants (SNR) in external galaxies through the combined use of radio, optical and X-ray surveys is discussed. Some 24 likely distant galaxy SNR have been found in the past six years, though confirmation is often difficult. Radio surveys of other galaxies are restricted by background object contamination in the field, and confirmation of these candidates requires other techniques. Optical measurement of the ratio of the forbidden SII doublet at .6717 and .6731 microns to H-alpha, followed by spectroscopic or radio confirmation, has successfully identified SNR in the LMC and other galaxies, though few in number. Most of the SNR in the Magellanic Clouds have been detected as X-ray emitters, but towards M31 there are no coincidences between the lists of optical SNR and X-ray sources. An increase in SNR identifications should result from use of the Space Telescope and continued use of the VLA.

  10. Feasibility of Preoperative FDG PET/CT Total Hepatic Glycolysis in the Remnant Liver for the Prediction of Postoperative Liver Function.

    Science.gov (United States)

    Cho, Arthur; Chung, Yong Eun; Choi, Jin Sub; Kim, Kyung Sik; Choi, Gi Hong; Park, Young Nyun; Kim, Myeong-Jin

    2017-03-01

    The objective of our study was to investigate the prognostic value of total glycolysis of the remnant liver, which reflects both metabolic and anatomic liver function, for predicting postoperative hepatic insufficiency. Patients who underwent 18 F-FDG PET/CT and abdominal CT within 1 month of major hepatectomy were retrospectively analyzed. Total liver volume, remnant liver volume, the ratio of the remnant hepatic volume to the preoperative hepatic volume (RFRHV), and mean standardized uptake value (SUV mean ) were measured, and total glycolysis of the remnant liver was calculated. Clinical hepatic function reserve values, including the indocyanine green retention rate at 15 minutes, the model for end-stage liver disease (MELD) score, and aspartate aminotransferase to platelet ratio index (APRI), were calculated. Univariate and multivariate analyses were performed, and an optimal model for predicting hepatic insufficiency was developed. ROC curves were used to compare diagnostic performance. Of 149 patients, seven patients had hepatic insufficiency. The SUV mean showed the highest sensitivity (100%; specificity, 31.7%) for predicting hepatic insufficiency, and total glycolysis of the remnant liver showed the highest specificity (96.5%; sensitivity, 57.1%) for predicting hepatic insufficiency. On multivariate analysis, the odds ratio of APRI (> 5.4) and total glycolysis of the remnant liver (≤ 625.6) was 46.3 and 82.9, respectively, for predicting hepatic insufficiency. On ROC curve analysis, a new model composed of APRI and total glycolysis of the remnant liver showed a higher area under the ROC curve (A z ) value (A z = 0.899) than SUV mean (0.659), MELD score (0.618), APRI (0.693), RFRHV (0.797), and remnant liver volume (0.762). The total glycolysis of the remnant liver has moderate sensitivity and high specificity for predicting hepatic insufficiency. Combining the total glycolysis of the remnant liver and APRI yielded the best diagnostic performance for

  11. Impaired expression of key molecules of ammoniagenesis underlies renal acidosis in a rat model of chronic kidney disease.

    Science.gov (United States)

    Bürki, Remy; Mohebbi, Nilufar; Bettoni, Carla; Wang, Xueqi; Serra, Andreas L; Wagner, Carsten A

    2015-05-01

    Advanced chronic kidney disease (CKD) is associated with the development of renal metabolic acidosis. Metabolic acidosis per se may represent a trigger for progression of CKD. Renal acidosis of CKD is characterized by low urinary ammonium excretion with preserved urinary acidification indicating a defect in renal ammoniagenesis, ammonia excretion or both. The underlying molecular mechanisms, however, have not been addressed to date. We examined the Han:SPRD rat model and used a combination of metabolic studies, mRNA and protein analysis of renal molecules involved in acid-base handling. We demonstrate that rats with reduced kidney function as evident from lower creatinine clearance, lower haematocrit, higher plasma blood urea nitrogen, creatinine, phosphate and potassium had metabolic acidosis that could be aggravated by HCl acid loading. Urinary ammonium excretion was highly reduced whereas urinary pH was more acidic in CKD compared with control animals. The abundance of key enzymes and transporters of proximal tubular ammoniagenesis (phosphate-dependent glutaminase, PEPCK and SNAT3) and bicarbonate transport (NBCe1) was reduced in CKD compared with control animals. In the collecting duct, normal expression of the B1 H(+)-ATPase subunit is in agreement with low urinary pH. In contrast, the RhCG ammonia transporter, critical for the final secretion of ammonia into urine was strongly down-regulated in CKD animals. In the Han:SPRD rat model for CKD, key molecules required for renal ammoniagenesis and ammonia excretion are highly down-regulated providing a possible molecular explanation for the development and maintenance of renal acidosis in CKD patients. © The Author 2014. Published by Oxford University Press on behalf of ERA-EDTA. All rights reserved.

  12. Benner's remnants: culture, tradition and everyday understanding.

    Science.gov (United States)

    Paley, John

    2002-06-01

    Benner's account of meaning and embodiment in nursing depends on a theory which she has never fully articulated, although she makes numerous allusions to it. Behind the background of shared meanings hovers something called 'culture', which provides each individual with meaning, determines what counts as real for her, and actively hands down interpretation-laden practices. This view is based, Benner claims, on the Heideggerian assumption that the meaning and organization of a culture precedes individual meaning-giving activity. I explore Benner's implicit view of culture, drawing on her published work over 15 years, and offer an appraisal of it. In doing so, I attempt to make sense of some rather strange remarks Benner has recently made about 'remnants' of Cartesian and Kantian thinking being found in the everyday understandings of people with asthma. The concept of culture is developed with reference to both Benner's own work and that of the anthropologist, Clifford Geertz, whose work she frequently cites. Having identified the principal tenets of what we might conveniently call the Benner-Geertz theory, I proceed to interrogate the theory, using the recent anthropological literature -- and, in particular, materialist attacks on the idea of culture as a system of meanings -- in order to cast doubt on it. I also review, very briefly, an alternative way of understanding 'culture', which is not vulnerable to the same criticisms. Benner's implicit theory of culture is revealed, somewhat ironically, as an inverted form of Cartesian dualism. Its intellectual provenance is not Heidegger, who appears to reject it, but the sort of American sociology associated with Talcott Parsons. As a corollary, it is suggested that Benner's 'remnants' analogy cannot be justified, and that the idea of Cartesian and Kantian concepts permeating Western culture, infecting both the providers and receivers of health care, is a myth.

  13. The Remnant of Supernova 1987A

    Science.gov (United States)

    McCray, Richard; Fransson, Claes

    2016-09-01

    Although it has faded by a factor of ˜107, SN 1987A is still bright enough to be observed in almost every band of the electromagnetic spectrum. Today, the bolometric luminosity of the debris is dominated by a far-infrared (˜200μm) continuum from ˜0.5 M⊙ of dust grains in the interior debris. The dust is heated by UV, optical, and near-infrared (NIR) emission resulting from radioactive energy deposition by 44Ti. The optical light of the supernova debris is now dominated by illumination of the debris by X-rays resulting from the impact of the outer supernova envelope with an equatorial ring (ER) of gas that was expelled some 20,000 years before the supernova explosion. X-ray and optical observations trace a complex system of shocks resulting from this impact, whereas radio observations trace synchrotron radiation from relativistic electrons accelerated by these shocks. The luminosity of the remnant is dominated by an NIR (˜20μm) continuum from dust grains in the ER heated by collisions with ions in the X-ray emitting gas. With the Atacama Large Millimeter Array (ALMA), we can observe the interior debris at millimeter/submillimeter wavelengths, which are not absorbed by the interior dust. The ALMA observations reveal bright emission lines from rotational transitions of CO and SiO lines that provide a new window into the interior structure of the supernova debris. Optical, NIR, and ALMA observations all indicate strongly asymmetric ejecta. Intensive searches have failed to yield any evidence for the compact object expected to reside at the center of the remnant. The current upper limit to the luminosity of such an object is a few tens of solar luminosities.

  14. Apaf-1 Inhibitors Protect from Unwanted Cell Death in In Vivo Models of Kidney Ischemia and Chemotherapy Induced Ototoxicity

    Science.gov (United States)

    Orzáez, Mar; Marchán, Sandra; Mondragón, Laura; Montava, Rebeca; Valero, Juan García; Landeta, Olatz; Basañez, Gorka; Carbajo, Rodrigo J.; Pineda-Lucena, Antonio; Bujons, Jordi; Moure, Alejandra; Messeguer, Angel; Lagunas, Carmen; Herrero, Carmen; Pérez-Payá, Enrique

    2014-01-01

    Background Excessive apoptosis induces unwanted cell death and promotes pathological conditions. Drug discovery efforts aimed at decreasing apoptotic damage initially targeted the inhibition of effector caspases. Although such inhibitors were effective, safety problems led to slow pharmacological development. Therefore, apoptosis inhibition is still considered an unmet medical need. Methodology and Principal Findings The interaction between Apaf-1 and the inhibitors was confirmed by NMR. Target specificity was evaluated in cellular models by siRNa based approaches. Cell recovery was confirmed by MTT, clonogenicity and flow cytometry assays. The efficiency of the compounds as antiapoptotic agents was tested in cellular and in vivo models of protection upon cisplatin induced ototoxicity in a zebrafish model and from hypoxia and reperfusion kidney damage in a rat model of hot ischemia. Conclusions Apaf-1 inhibitors decreased Cytc release and apoptosome-mediated activation of procaspase-9 preventing cell and tissue damage in ex vivo experiments and in vivo animal models of apoptotic damage. Our results provide evidence that Apaf-1 pharmacological inhibition has therapeutic potential for the treatment of apoptosis-related diseases. PMID:25330150

  15. Full Modelling of High-Intensity Focused Ultrasound and Thermal Heating in the Kidney using Realistic Patient Models.

    Science.gov (United States)

    Suomi, Visa; Jaros, Jiri; Treeby, Bradley; Cleveland, Robin

    2017-07-28

    High-intensity focused ultrasound (HIFU) therapy can be used for non-invasive treatment of kidney (renal) cancer, but the clinical outcomes have been variable. In this study, the efficacy of renal HIFU therapy was studied using nonlinear acoustic and thermal simulations in three patients. The acoustic simulations were conducted with and without refraction in order to investigate its effect on the shape, size and pressure distribution at the focus. The values for the attenuation, sound speed, perfusion and thermal conductivity of the kidney were varied over the reported ranges to determine the effect of variability on heating. Furthermore, the phase aberration was studied in order to quantify the underlying phase shifts using a second order polynomial function. The ultrasound field intensity was found to drop on average 11.1 dB with refraction and 6.4 dB without refraction. Reflection at tissue interfaces was found to result in a loss less than 0.1 dB. Focal point splitting due to refraction significantly reduced the heating efficacy. Of all the tissue parameters, perfusion was found to affect the heating the most. Small changes in temperature were seen with varying attenuation and thermal conductivity, but no visible changes were present with sound speed variations. The aberration study revealed an underlying trend in the spatial distribution of the phase shifts. The results show that the efficacy of HIFU therapy in the kidney could be improved with aberration correction. A method is proposed by which patient specific pre-treatment calculations could be used to overcome the aberration and therefore make ultrasound treatment possible.

  16. Nitric oxide synthase and changes in oxidative stress levels in embryonic kidney observed in a rabbit model of intrauterine growth restriction.

    Science.gov (United States)

    Figueroa, Horacio; Cifuentes, Jorge; Lozano, Mauricio; Alvarado, Cristobal; Cabezas, Claudia; Eixarch, Elisenda; Fernández, Ellio; Contreras, Luis; Illanes, Sebastian E; Hernández-Andrade, Edgar; Gratacós, Eduard; Irarrazabal, Carlos E

    2016-07-01

    This work aimed to study the effect of uteroplacental circulation restriction on endothelial kidney damage in a fetal rabbit model. New Zealand rabbits were subjected to 40% to 50% of uteroplacental artery ligation at day 25 of pregnancy. After 5 days, surviving fetuses were harvested by cesarean section. The gene and protein expressions of selected enzymes associated with nitric oxide production and oxidative stress were analyzed in fetal kidney homogenates. The placenta weight (6.06 ± 0.27, p nitric oxide synthase phosphorylation inhibition (0.23 ± 0.13, p nitric oxide synthase messenger RNA (mRNA) (2.68 ± 0.24, p oxidative damage in kidneys of fetal rabbits that have been exposed to restriction of the uterine circulation. © 2016 John Wiley & Sons, Ltd. © 2016 John Wiley & Sons, Ltd.

  17. Renal Doppler and Novel Biomarkers to Assess Acute Kidney Injury in a Swine Model of Ventricular Fibrillation Cardiac Arrest

    Directory of Open Access Journals (Sweden)

    Xue Mei

    2015-01-01

    Full Text Available Background: Majority of the research on cardiac arrest (CA have focused on post-CA brain injury and myocardial dysfunction, the renal dysfunction and acute kidney injury (AKI in other critical illnesses after CA have not been well described. This study was designed to assess AKI with renal Doppler and novel AKI biomarkers in a swine model of ventricular fibrillation cardiac arrest (VFCA. Methods: Thirty healthy piglets were divided into VFCA group (n = 22 and Sham group (n = 8 in a blinded manner. Mean arterial pressure, heart rate, and cardiac output were recorded continuously. Cardiac arrest (CA was induced by programmed electric stimulation in the VFCA group, and then cardiopulmonary resuscitation was performed. Twenty piglets returned of spontaneous circulation (ROSC and received intensive care. Blood and urine samples were collected for AKI biomarkers testing, and Color Doppler flow imaging was performed at baseline, 6 h, 12 h, and 24 h, respectively after ROSC. At ROSC 24 h, the animals were sacrificed and a semi-quantitative evaluation of pathologic kidney injury was performed. Results: In the VFCA group, corrected resistive index (cRI increased from 0.47 ± 0.03 to 0.64 ± 0.06, and pulsatility index (PI decreased from 0.82 ± 0.03 to 0.68 ± 0.04 after ROSC. Cystatin C (CysC in both serum and urine samples increased at ROSC 6 h, but neutrophil gelatinase-associated lipocalin (NGAL in serum increased to 5.34 ± 1.68 ng/ml at ROSC 6 h, and then decreased to 3.16 ± 0.69 ng/ml at ROSC 24 h while CysC increasing constantly. According to the renal histopathology, 18 of 20 animals suffered from kidney injury. The grade of renal injury was highly correlated with RI, cRI, NGAL, and CysC. Linear regression equation was established: Grade of renal injury = 0.002 × serum CysC + 6.489 × PI + 4.544 × cRI - 8.358 (r2 = 0.698, F = 18.506, P < 0.001. Conclusions: AKI is common in post-CA syndrome. Renal Doppler and novel AKI biomarkers in serum and

  18. Remnant radio-loud AGN in the Herschel-ATLAS field arXiv

    CERN Document Server

    Mahatma, V.H.; Williams, W.L.; Brienza, M.; Brüggen, M.; Croston, J.H.; Gurkan, G.; Harwood, J.J.; Kunert-Bajraszewska, M.; Morganti, R.; Röttgering, H.J. A.; Shimwell, T.W.; Tasse, C.

    Only a small fraction of observed Active Galactic Nuclei display large-scale radio emission associated with jets, yet these radio-loud AGN have become increasingly important in models of galaxy evolution. In determining the dynamics and energetics of the radio sources over cosmic time, a key question concerns what happens when their jets switch off. The resulting `remnant' radio-loud AGN have been surprisingly evasive in past radio surveys, and therefore statistical information on the population of radio-loud AGN in their dying phase is limited. In this paper, with the recent developments of LOFAR and the VLA, we are able to provide a systematically selected sample of remnant radio-loud AGN in the Herschel-ATLAS field. Using a simple core-detection method, we constrain the upper limit on the fraction of remnants in our radio-loud AGN sample to 9 per cent, implying that the extended lobe emission fades rapidly once the core/jets turn off. We also find that our remnant sample has a wide range of spectral indice...

  19. AT1 Receptor Antagonism Improves Structural, Functional and Biomechanical Properties in Resistance Arteries in a Rodent Chronic Kidney Disease Model.

    Science.gov (United States)

    Quek, K J; Ameer, O Z; Phillips, J K

    2018-02-07

    The renin-angiotensin system, in particular Angiotensin II (AngII), plays a significant role in the pathogenesis of hypertension in chronic kidney disease (CKD). Effects of chronic AT1 receptor antagonism were investigated in a genetic hypertensive rat model of CKD, the Lewis polycystic kidney (LPK) rat. Mixed-sex LPK and Lewis control rats (total n=31) were split between treated (valsartan 60mg/kg/day p.o. from 4-18 weeks) and vehicle groups. Animals were assessed for systolic blood pressure and urine biochemistry, and after euthanasia, blood collected for urea and creatinine analysis, confirming the hypertensive and renal phenotype. Mesenteric resistance vasculature was assessed using pressure myography and histology. Valsartan treatment improved LPK rats vascular structure, increasing internal and external diameter values and reducing wall thickness (untreated vs. treated LPK: 53.19±3.29 vs. 33.93±2.17m) and wall-lumen ratios (untreated vs. treated LPK: 0.52±0.09 vs. 0.16±0.01 (all P<0.0001). Endothelium dysfunction, as measured by maximal response to acetylcholine (Rmax) was normalized with treatment (untreated vs. treated LPK: 69.56±4.34 vs. 103.05±4.13, P<0.05), increasing the relative contributions of nitric oxide and endothelium-derived hyperpolarization to vasorelaxation while down-regulating the prostanoid contribution. Biomechanical properties also improved with treatment, as indicated by an increase in compliance, decrease in intrinsic stiffness, and alterations in the artery wall composition, which included decreases in collagen density and collagen/elastin ratio. Our results highlight the importance of AngII as a driver of resistance vessel structural, functional and biomechanical dysfunction and provide insight as to how AT1 receptor blockade exerts therapeutic efficacy in CKD.

  20. Polycystic Kidney Rat Is a Novel Animal Model of Caroli’s Disease Associated with Congenital Hepatic Fibrosis

    Science.gov (United States)

    Sanzen, Takahiro; Harada, Kenichi; Yasoshima, Mitsue; Kawamura, Yasuhito; Ishibashi, Masahiko; Nakanuma, Yasuni

    2001-01-01

    Caroli’s disease (congenital intrahepatic biliary dilatation) associated with congenital hepatic fibrosis is an autosomal recessive polycystic kidney disease. Recently, the polycystic kidney (PCK) rat, a spontaneous mutant derived from a colony of Crj:CD rats with polycystic lesions in the liver and an autosomal recessive mode of inheritance, was reported. In the present study, the pathology of the hepatobiliary system and the biliary cell-kinetics were evaluated in fetuses (day 18 to 21 of gestation) and neonates and adults (1 day to 4 months after delivery) of PCK rats. Crj:CD rats were used as a control. Multiple segmental and saccular dilatations of intrahepatic bile ducts were first observed in fetuses at 19 days of gestation. The dilatation spread throughout the liver and the degree of dilatation increased with aging. Gross and histological features characterizing ductal plate malformation were common in the intrahepatic bile ducts. Overgrowth of portal connective tissue was evident and progressive after delivery. These features were very similar to those of Caroli’s disease with congenital hepatic fibrosis. Proliferative activity in the biliary epithelial cells was greater in PCK rats than controls during the development. In contrast, the biliary epithelial apoptosis was less extensive in PCK rats than the controls until 1 week after delivery, but greater after 3 weeks, suggesting that the remodeling defect in immature bile ducts associated with the imbalance of cell kinetics plays a role in the occurrence of intrahepatic biliary anomalies in PCK rats. The PCK rat could be a useful and promising animal model of Caroli’s disease with congenital hepatic fibrosis. PMID:11337358

  1. Chronic Kidney Diseases

    Science.gov (United States)

    ... Weight for Me? Your Teeth Heart Murmurs Chronic Kidney Diseases KidsHealth > For Kids > Chronic Kidney Diseases Print A ... pressure at a healthy level. continue Kinds of Kidney Diseases Like any complicated machine, not all kidneys work ...

  2. About Chronic Kidney Disease

    Science.gov (United States)

    ... Advocacy Donate A to Z Health Guide About Chronic Kidney Disease Tweet Share Print Email Chronic kidney disease (CKD) ... Learn about Glomerular Filtration Rate (GFR) What is chronic kidney disease (CKD)? Chronic kidney disease includes conditions that damage ...

  3. Three Great Eyes on Kepler's Supernova Remnant

    Science.gov (United States)

    2004-01-01

    [figure removed for brevity, see original site] Composite [figure removed for brevity, see original site] [figure removed for brevity, see original site] Chandra X-Ray Data (blue) Chandra X-Ray Data (green)Hubble Telescope (visible-light)Spitzer Telescope (infrared) NASA's three Great Observatories -- the Hubble Space Telescope, the Spitzer Space Telescope, and the Chandra X-ray Observatory -- joined forces to probe the expanding remains of a supernova, called Kepler's supernova remnant, first seen 400 years ago by sky watchers, including astronomer Johannes Kepler. The combined image unveils a bubble-shaped shroud of gas and dust that is 14 light-years wide and is expanding at 4 million miles per hour (2,000 kilometers per second). Observations from each telescope highlight distinct features of the supernova remnant, a fast-moving shell of iron-rich material from the exploded star, surrounded by an expanding shock wave that is sweeping up interstellar gas and dust. Each color in this image represents a different region of the electromagnetic spectrum, from X-rays to infrared light. These diverse colors are shown in the panel of photographs below the composite image. The X-ray and infrared data cannot be seen with the human eye. By color-coding those data and combining them with Hubble's visible-light view, astronomers are presenting a more complete picture of the supernova remnant. Visible-light images from the Hubble telescope (colored yellow) reveal where the supernova shock wave is slamming into the densest regions of surrounding gas. The bright glowing knots are dense clumps from instabilities that form behind the shock wave. The Hubble data also show thin filaments of gas that look like rippled sheets seen edge-on. These filaments reveal where the shock wave is encountering lower-density, more uniform interstellar material. The Spitzer telescope shows microscopic dust particles (colored red) that have been heated by the supernova shock wave. The dust re

  4. Kidney pain (image)

    Science.gov (United States)

    A kidney stone is a solid piece of material that forms in a kidney. Kidney stones may be the size of sand or ... A kidney stone is a solid piece of material that forms in a kidney. Kidney stones may be the ...

  5. Kidney School

    Science.gov (United States)

    ... Kidney School for: ¿Hablas Español? Haga clic aquí. Introduction View Online Download English Español Listen Printing multiple ... Listen Printing multiple copies? Read our licensing agreement Nutrition and Fluids for People on Dialysis People on ...

  6. Generation of Cosmic rays in Historical Supernova Remnants

    Directory of Open Access Journals (Sweden)

    Sinitsyna V.Y.

    2013-06-01

    Full Text Available We present the results of observations of two types of Galactic supernova remnants with the SHALON mirror Cherenkov telescope of Tien-Shan high-mountain Observatory: the shell-type supernova remnants Tycho, Cas A and IC 443; plerions Crab Nebula, 3c58(SN1181 and Geminga (probably plerion. The experimental data have confirmed the prediction of the theory about the hadronic generation mechanism of very high energy (800 GeV - 100 TeV gamma-rays in Tycho's supernova remnant. The data obtainedsuggest that the very high energy gamma-ray emission in the objects being discussedis different in origin.

  7. Discordant Lipid Pattern and Carotid Atherosclerotic Plaque. Importance of Remnant Cholesterol

    Directory of Open Access Journals (Sweden)

    Walter Masson

    Full Text Available Abstract Background: Subjects with levels of non-HDL-C 30 mg/dL above those of LDL-C (lipid discordance or with high remnant cholesterol levels could have a greater residual cardiovascular risk. Objectives: To determine the prevalence of lipid discordance in a primary prevention population and analyze the clinical variables associated with it; To investigate the association between lipid discordance and remnant cholesterol with the presence of carotid plaque. Methods: Primary prevention patients without diabetes or lipid-lowering therapy were included. Regardless of the LDL-C level, we define “lipid discordance” if the non-HDL-C value exceeded 30 mg/dL that of LDL-C. Remnant cholesterol was calculated as total cholesterol minus HDL-C minus LDL-C when triglycerides were < 4.0 mmol/L. Ultrasound was used to assess carotid plaque occurrence. Multiple regression logistic models were performed. Results: The study included 772 patients (mean age 52 ± 11 years, 66% women. The prevalence of lipid discordance was 34%. Male sex and body mass index were independently associated with discordant lipid pattern. The prevalence of carotid plaque was higher in subjects with lipid discordance (40.2% vs. 29.2, p = 0.002. The multivariate analysis showed that the discordant lipid pattern was associated with the greater probability of carotid plaque (OR 1.58, 95% CI 1.08-2.34, p = 0.02. Similarly, a significant association between calculated remnant cholesterol and carotid plaque was found. Conclusion: Lipid discordance and presence of a higher level of calculated remnant cholesterol are associated with subclinical atherosclerosis. Our findings could be used to improve the residual cardiovascular risk evaluation.

  8. Galactic Supernova Remnant Candidates Discovered by THOR

    Science.gov (United States)

    Anderson, Loren; Wang, Yuan; Bihr, Simon; Rugel, Michael; Beuther, Henrik; THOR Team

    2018-01-01

    There is a considerable deficiency in the number of known supernova remnants (SNRs) in the Galaxy compared to that expected. Searches for extended low-surface brightness radio sources may find new Galactic SNRs, but confusion with the much larger population of HII regions makes identifying such features challenging. SNRs can, however, be separated from HII regions using their significantly lower mid-infrared (MIR) to radio continuum intensity ratios. We use the combination of high-resolution 1-2 GHz continuum data from The HI, OH, Recombination line survey of the Milky Way (THOR) and lower-resolution VLA 1.4 GHz Galactic Plane Survey (VGPS) continuum data, together with MIR data from the Spitzer GLIMPSE, Spitzer MIPSGAL, and WISE surveys to identify SNR candidates. To ensure that the candidates are not being confused with HII regions, we exclude radio continuum sources from the WISE Catalog of Galactic HII Regions, which contains all known and candidate H II regions in the Galaxy. We locate 76 new Galactic SNR candidates in the THOR and VGPS combined survey area of 67.4deg>l>17.5deg, |b|increase would still, however, leave a discrepancy between the known and expected SNR populations of about a factor of two.

  9. Magnetic Field Amplification in Supernova Remnants

    Science.gov (United States)

    Xu, Siyao; Lazarian, Alex

    2017-12-01

    Based on the new findings on the turbulent dynamo in Xu & Lazarian, we examine the magnetic field amplification in the context of supernova remnants. Due to the strong ion-neutral collisional damping in the weakly ionized interstellar medium, the dynamo in the preshock turbulence remains in the damping kinematic regime, which leads to a linear-in-time growth of the magnetic field strength. The resultant magnetic field structure enables effective diffusion upstream and shock acceleration of cosmic rays to energies above the “knee.” Differently, the nonlinear dynamo in the postshock turbulence leads to a linear-in-time growth of the magnetic energy due to the turbulent magnetic diffusion. Given a weak initial field strength in the postshock region, the magnetic field saturates at a significant distance from the shock front as a result of the inefficiency of the nonlinear dynamo. This result is in a good agreement with existing numerical simulations and well explains the X-ray spots detected far behind the shock front.

  10. Fasting remnant lipoproteins can predict postprandial hyperlipidemia

    Directory of Open Access Journals (Sweden)

    Nagata Tomoki

    2012-10-01

    Full Text Available Abstract Background Hypertriglyceridemia and postprandial hyperlipidemia is thought to play an important role in atherosclerosis, but to select patients at high-risk for cardiovascular diseases is difficult with triglycerides (TG alone in these patients. Methods To predict postprandial hyperlipidemia without inconvenient test meal loading, we examined lipid concentrations before and after test meal loading and fasting adiponectin, and investigated which of these other than TG were significant during the fasting period in 45 healthy individuals (men: women, 26:19. Results TG, remnant-like particle-cholesterol and -triglyceride (RemL-C, RLP-C, and RLP-TG, and TG/apolipoprotein(apoB were significantly elevated after loading and fasting values significantly and positively correlated with incremental area under the curve (iAUC (r=0.80, r=0.79, r=0.63, r=0.58, r=0.54; p Conclusion Fasting triglyceride-rich lipoprotein-related values, especially RemL-C, RLP-C, RLP-TG, and TG/apoB are useful predictors of postprandial hyperlipidemia in young healthy individuals. Although fasting adiponectin concentration correlated with the iAUCs for TG, RemL-C, RLP-C, RLP-TG, and TG/apoB, it was not a significant predictor of postprandial hyperlipidemia in multivariable linear regression analysis.

  11. An epidemic model for the interactions between thermal regime of rivers and transmission of Proliferative Kidney Disease in salmonid fish

    Science.gov (United States)

    Carraro, Luca; Bertuzzo, Enrico; Mari, Lorenzo; Gatto, Marino; Strepparava, Nicole; Hartikainen, Hanna; Rinaldo, Andrea

    2015-04-01

    Proliferative kidney disease (PKD) affects salmonid populations in European and North-American rivers. It is caused by the endoparasitic myxozoan Tetracapsuloides bryosalmonae, which exploits freshwater bryozoans (Fredericella sultana) and salmonids as primary and secondary hosts, respectively. Incidence and mortality, which can reach up to 90-100%, are known to be strongly related to water temperature. PKD has been present in brown trout population for a long time but has recently increased rapidly in incidence and severity causing a decline in fish catches in many countries. In addition, environmental changes are feared to cause PKD outbreaks at higher latitude and altitude regions as warmer temperatures promote disease development. This calls for a better comprehension of the interactions between disease dynamics and the thermal regime of rivers, in order to possibly devise strategies for disease management. In this perspective, a spatially explicit model of PKD epidemiology in riverine host metacommunities is proposed. The model aims at summarizing the knowledge on the modes of transmission of the disease and the life-cycle of the parasite, making the connection between temperature and epidemiological parameters explicit. The model accounts for both local population and disease dynamics of bryozoans and fish and hydrodynamic dispersion of the parasite spores and hosts along the river network. The model is time-hybrid, coupling inter-seasonal and intra-seasonal dynamics, the former being described in a continuous time domain, the latter seen as time steps of a discrete time domain. In order to test the model, a case study is conducted in river Wigger (Cantons of Aargau and Lucerne, Switzerland), where data about water temperature, brown trout and bryozoan populations and PKD prevalence are being collected.

  12. Aging Male Spontaneously Hypertensive Rat as an Animal Model for the Evaluation of the Interplay between Contrast-Induced Acute Kidney Injury and Cardiorenal Syndrome in Humans.

    Science.gov (United States)

    Zhang, Jun; Fallahzadeh, Mohammad Kazem; McCullough, Peter A

    2016-11-01

    Although there are some animal models for biomarkers of contrast-induced acute kidney injury (CI-AKI), for cardiorenal syndrome (CRS) and for acute renal failure, the interplay between CI-AKI and CRS has yet to be evaluated. Insight into the pathogenesis of CRS is urgently needed from animal models in order to foster the discovery and implementation of novel biomarkers for this disease. Specially designed animal models for type 1 and 3 CRS, particularly CI-AKI, have not yet emerged. We hypothesize that the aging male spontaneously hypertensive rat (SHR) is likely to be a suitable model. The SHR model is able to mimic risk factors for preclinical CRS that appears in the clinical setting, specifically hypertension, age, preexisting damage and dysfunction of the heart and kidney, endothelial dysfunction, increased level of reactive oxygen species, decreased level and bioavailability of nitric oxide (NO), impairment of the L-arginine-NO pathway, and insulin resistance. In the SHR, CI-AKI results in a different profile of AKI biomarkers than is seen with preexisting chronic kidney injury. The SHR model can be used to evaluate the interaction between CI-AKI and CRS type 1 and 3 and to verify neutrophil gelatinase-associated lipocalin (NGAL) as a reliable CI-AKI biomarker for clinical application. Further research is warranted with a large number of aging male SHRs to prove NGAL as a sensitive, specific, highly predictive, early biomarker for CI-AKI.

  13. The surviving companions in type Ia supernova remnants

    Science.gov (United States)

    Chen, Li-Qing; Meng, Xiang-Cun; Han, Zhan-Wen

    2017-08-01

    The single-degenerate (SD) model is one of the most popular progenitor models of type Ia supernovae (SNe Ia), in which the companion star can survive after an SN Ia explosion and show peculiar properties. Therefore, searching for the surviving companion in type Ia supernova remnants (SNRs) is a potential method to verify the SD model. In the SN 1604 remnant (Kepler’s SNR), although Chandra X-ray observation suggests that the progenitor is most likely a WD+AGB system, a the surviving companion has not been found. One possible reason is rapid rotation of the white dwarf (WD), causing explosion of the WD to be delayed for a spin-down timescale, and then the companion evolved into a WD before the supernova explosion, so the companion is too dim to be detected. We aim to verify this possible explanation by carrying out binary evolution calculations. In this paper, we use Eggleton’s stellar evolution code to calculate the evolution of binaries consisting of a WD+red giant (RG). We assume that the rapidly rotating WD can continuously increase its mass when its mass exceeds the Chandrasekhar mass limit ({M}{{Ch}}=1.378 {M}⊙ ) until the mass-transfer rate decreases to be lower than a critical value. Eventually, we obtain the final masses of a WD in the range 1.378 M ⊙ to 2.707 M ⊙. We also show that if the spin-down time is less than 106 yr, the companion star will be very bright and easily observed; but if the spin-down time is as long as ˜ 107 yr, the luminosities of the surviving companion would be lower than the detection limit. Our simulation provides guidance in hunting for the surviving companion stars in SNRs, and the fact that no surviving companion has been found in Kepler’s SNR may not be definite evidence disfavoring the SD origin of Kepler’s SN.

  14. Inventory of Atlantic White Cedar Remnant Stands in North Carolina.

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This inventory was commissioned by the U.S. Air Force to identify the location and condition of extant remnant Atlantic white cedar groves and stands in North...

  15. Cystic duct remnant mucocele in a liver transplant recipient

    Energy Technology Data Exchange (ETDEWEB)

    Ahlawat, Sushil K. [Georgetown University Hospital, Department of Medicine, Division of Gastroenterology, Washington, DC (United States); University of Medicine and Dentistry of New Jersey, New Jersey Medical School, Newark, NJ (United States); Fishbien, Thomas M. [Georgetown University Hospital, Department of Medicine, Division of Gastroenterology, Washington, DC (United States); Haddad, Nadim G. [Georgetown University Hospital, Department of Surgery, Division of Transplant Surgery, Washington, DC (United States)

    2008-08-15

    Cystic duct remnant mucocele is an extremely rare complication of liver transplantation in children. Surgical correction is usually required for cystic duct remnant mucocele when it causes biliary obstruction. We describe a 14-month-old liver transplant recipient who presented with biliary obstruction 1 month after orthotopic liver transplantation with an end-to-end choledochocholedocal biliary anastomosis for hepatoblastoma. US, CT and cholangiography findings were consistent with mucocele of the allograft cystic duct remnant. Surgery was not needed in our patient because the mucocele and biliary obstruction had resolved on repeat imaging most likely due to guidewire manipulation during cholangiography, resulting in opening of the cystic duct remnant orifice and drainage into the common duct. (orig.)

  16. Hematite Mineralized Bacterial Remnants: Implications for Martian Hematite Deposits

    Science.gov (United States)

    Schelble, Rachel T.; Westall, Frances; Allen, Carlton C.; Brearley, Adrian J.

    2001-01-01

    Hematite mineralized bacterial remnants in the Gunflint Formation [early Proterozoic] can be used as an analog for potential microfossils in martian iron deposits. Additional information is contained in the original extended abstract.

  17. Pervasive defaunation of forest remnants in a tropical biodiversity hotspot

    National Research Council Canada - National Science Library

    Canale, Gustavo R; Peres, Carlos A; Guidorizzi, Carlos E; Gatto, Cassiano A Ferreira; Kierulff, Maria Cecília M

    2012-01-01

    ... in unprotected forest remnants remain poorly explained. Here, we report unprecedented rates of local extinctions of medium to large-bodied mammals in one of the world's most important tropical biodiversity hotspot...

  18. An unusual white dwarf star may be a surviving remnant of a subluminous Type Ia supernova

    Science.gov (United States)

    Vennes, S.; Nemeth, P.; Kawka, A.; Thorstensen, J. R.; Khalack, V.; Ferrario, L.; Alper, E. H.

    2017-08-01

    Subluminous Type Ia supernovae, such as the Type Iax-class prototype SN 2002cx, are described by a variety of models such as the failed detonation and partial deflagration of an accreting carbon-oxygen white dwarf star or the explosion of an accreting, hybrid carbon-oxygen-neon core. These models predict that bound remnants survive such events with, according to some simulations, a high kick velocity. We report the discovery of a high proper motion, low-mass white dwarf (LP 40-365) that travels at a velocity greater than the Galactic escape velocity and whose peculiar atmosphere is dominated by intermediate-mass elements. Strong evidence indicates that this partially burnt remnant was ejected following a subluminous Type Ia supernova event. This supports the viability of single-degenerate supernova progenitors.

  19. Magnetic field in supernova remnant SN 1987A

    OpenAIRE

    Berezhko, E. G.; Ksenofontov, L. T.

    2006-01-01

    A nonlinear kinetic theory of cosmic ray (CR) acceleration in supernova remnants is employed to investigate the properties of the remnant SN 1987A. It is shown that a large downstream magnetic field ~10 mG is required to fit the existing observational data. Such a strong field together with the strong shock modification due to CR backreaction provides the steep and concave radioemission spectrum and considerable synchrotron cooling of high energy electrons which diminish their X-ray synchrotr...

  20. Investigation of oxidative stress in blood, brain, kidney, and liver after oxime antidote HI-6 application in a mouse experimental model.

    Science.gov (United States)

    Pohanka, Miroslav; Sobotka, Jakub; Svobodova, Hana; Stetina, Rudolf

    2011-07-01

    Oxime reactivator HI-6 (asoxime, in some sources) is a potent antidote suitable for treatment of intoxication by nerve agents. Despite the fact that HI-6 is considered for practical application in emergency situations, the impact of HI-6 on patients' bodies has not been established yet. The present experiment was carried out in order to estimate whether HI-6 would be able to trigger or protect from oxidative stress in a BALB/c mice model. HI-6 was applied in doses ranging from 0.2 to 20% of LD₅₀. Ferric-reducing antioxidant power (FRAP), thiobarbituric acid reactive substances (TBARS), reduced glutathione (GSH), and glutathione reductase (GR) were assayed in the blood, liver, kidney, and brain of treated animals. It was found that HI-6 does not increase GR or TBARS. On the contrary, TBARS levels in the brain and liver were found to be significantly decreased in HI-6-treated animals. Pertinent antioxidant properties of HI-6 were excluded by the FRAP method. Endogenous antioxidants were unchanged, with the exception of the kidney. Low-molecular-weight antioxidants assayed by the FRAP method were significantly decreased in kidneys of animals treated with HI-6. However, GSH partially recovered the loss of the other low-molecular-weight antioxidants and was significantly increased in the kidney of HI-6-exposed mice. HI-6 potential to produce nephropathy is hypothesized. The achieved conclusions were quite surprising and showed a complex impact of HI-6 on the body.

  1. Transport of magnetic turbulence in supernova remnants

    Science.gov (United States)

    Brose, R.; Telezhinsky, I.; Pohl, M.

    2016-08-01

    Context. Supernova remnants are known as sources of Galactic cosmic rays for their nonthermal emission of radio waves, X-rays, and gamma rays. However, the observed soft broken power-law spectra are hard to reproduce within standard acceleration theory based on the assumption of Bohm diffusion and steady-state calculations. Aims: We point out that a time-dependent treatment of the acceleration process together with a self-consistent treatment of the scattering turbulence amplification is necessary. Methods: We numerically solve the coupled system of transport equations for cosmic rays and isotropic Alfvénic turbulence. The equations are coupled through the growth rate of turbulence determined by the cosmic-ray gradient and the spatial diffusion coefficient of cosmic rays determined by the energy density of the turbulence. The system is solved on a comoving expanding grid extending upstream for dozens of shock radii, allowing for the self-consistent study of cosmic-ray diffusion in the vicinity of their acceleration site. The transport equation for cosmic rays is solved in a test-particle approach. Results: We demonstrate that the system is typically not in a steady state. In fact, even after several thousand years of evolution, no equilibrium situation is reached. The resulting time-dependent particle spectra strongly differ from those derived assuming a steady state and Bohm diffusion. Our results indicate that proper accounting for the evolution of the scattering turbulence and hence the particle diffusion coefficient is crucial for the formation of the observed soft spectra. In any case, the need to continuously develop magnetic turbulence upstream of the shock introduces nonlinearity in addition to that imposed by cosmic-ray feedback.

  2. Healing Potential of the Anterior Cruciate Ligament Remnant Stump.

    Science.gov (United States)

    Trocan, Ilie; Ceausu, Raluca A; Jitariu, Andreea A; Haragus, Horia; Damian, Gratian; Raica, Marius

    2016-01-01

    The aim of this study was to analyze the microstructural architecture and cellular differentiation of the anterior cruciate ligament (ACL) stumps in different stages after injury, as this could augment graft biointegration. The histological appearance and immunoreaction for cluster of differentiation 34 antigen (CD34) of 54 biopsies from 27 remnants were compared to 10 biopsies from 5 normal cruciate ligaments. CD34 reaction in endothelial cells, fibroblasts and fibrocytes was consistently positive in small synovial vessels. Remnants also exhibited CD34(+) cells among collagen fibers. Blood vessel density varied between specimens. The mean vascular microdensity was 43 per ×200 field in remnants compared to 15.2 in controls. A total of 94.44% of remnant ACL samples had significant hyperplasia of stellate and fusiform stromal cells, CD34(+); 22.4% had developed capillary vessels inside the ligament; 33% exhibited ongoing angiogenesis. Significant differences exist between torn and intact ACL regarding microvascularization. The remnants contain stellate stromal cells and CD34(+) fibrocytes, and display angiogenesis both at synovia as well as in the ligament itself. These findings underline the potential contribution to neoligament healing when remnants are preserved. Copyright © 2016 International Institute of Anticancer Research (Dr. John G. Delinassios), All rights reserved.

  3. Properties of Optically Selected Supernova Remnant Candidates in M33

    Science.gov (United States)

    Lee, Jong Hwan; Lee, Myung Gyoon

    2014-10-01

    Narrowband images covering strong emission lines are efficient for surveying supernova remnants (SNRs) in nearby galaxies. Using the narrowband images provided by the Local Group Galaxy Survey, we searched for SNRs in M33. Culling the objects with enhanced [S II]/Hα and round morphology in the continuum-subtracted Hα and [S II] images, we produced a list of 199 sources. Among them, 79 are previously unknown. Their progenitor and morphology types were classified. A majority of the sample (170 objects) are likely remnants of core-collapse supernovae (SNe), and 29 are remnants of Type Ia SNe. The cumulative size distribution of these objects is found to be similar to that of the M31 remnants derived in a similar way. We obtain a power-law slope, α = 2.38 ± 0.05. Thus, a majority of the sources are considered to be in the Sedov-Taylor phase, consistent with previous findings. The histogram of the emission-line ratio ([S II]/Hα) of the remnants has two concentrations at [S II]/Hα ~ 0.55 and ~0.8, as in M31. Interestingly, L X (and L 20 cm) of the compact center-bright objects are correlated with their optical luminosity. The remnants with X-ray emission have brighter optical surface brightnesses and smaller diameters than those without X-ray emission.

  4. Construction of kidney phantom model with acoustic shadow by rib bones and respiratory organ motion

    Science.gov (United States)

    Lee, Dongjun; Koizumi, Norihiro; Tsukihara, Hiroyuki; Azuma, Takashi; Nomiya, Akira; Yoshinaka, Kiyoshi; Sugita, Naohiko; Homma, Yukio; Matsumoto, Yoichiro; Mitsuishi, Mamoru

    2017-03-01

    We have been studying the Non-Invasive Ultrasound Theragnostic System (NIUTS), which tracks and follows the affected area while irradiating High Intensity Focused Ultrasound (HIFU). In this report, we propose a phantom model that includes rib bones and respiratory motion.

  5. Superdiffusion of relativistic electrons at supernova remnant shocks

    Science.gov (United States)

    Perri, Silvia

    2018-01-01

    Anomalous transport has been observed in various systems as nonlinear systems, numerical simulations of plasma turbulence, in laboratory plasmas, and recently in the propagation of energetic particles in the interplanetary space. Thanks to in situ observations it has been possible to deduce transport properties directly from spacecraft data. This technique has further found applicability to remote observations of relativistic electrons accelerated at supernova remnants (SNRs) shocks, pointing out that far upstream of the blast waves, the x-ray synchrotron emission, as captured by the Chandra spacecraft, is consistent with models of superdiffusive transport (i.e., transport faster than normal diffusive). Here we present and summarize evidences of superdiffusion both in the interplanetary space and upstream of SNRs shock fronts, in particular by analyzing, for the first time in the framework of superdiffusion, the transport properties of electrons accelerated at the young G1.9+0.3 SNR. We also briefly describe how this new model can be used to interpret radio emissions from electrons accelerated at shocks forming during galaxy cluster mergers.

  6. Differential rescue of the renal and hepatic disease in an autosomal recessive polycystic kidney disease mouse mutant. A new model to study the liver lesion.

    OpenAIRE

    Yoder, B. K.; Richards, W. G.; Sommardahl, C.; Sweeney, W. E.; Michaud, E. J.; Wilkinson, J. E.; Avner, E. D.; Woychik, R. P.

    1997-01-01

    Autosomal recessive polycystic kidney disease (ARPKD) is characterized by biliary and renal lesions that produce significant morbidity and mortality. The biliary ductual ectasia and hepatic portal fibrosis associated with ARPKD have not been well studied even though such lesions markedly affect the clinical course of patients after renal replacement therapy such as dialysis or transplantation. Here we describe the generation of a new mouse model to study the hepatic lesions associated with po...

  7. The effect of tadalafil therapy on kidney damage caused by sepsis in a polymicrobial septic model induced in rats: a biochemical and histopathological study.

    Science.gov (United States)

    Benli, Erdal; Ayyildiz, Sema Nur; Cirrik, Selma; Koktürk, Sibel; Cirakoglu, Abdullah; Noyan, Tevfik; Ayyildiz, Ali; Germiyanoglu, Cankon

    2017-01-01

    Sepsis is an inflammatory reaction to bacteria involving the whole body and is a significant cause of mortality and economic costs. The purpose of this research was to determine whether tadalafil exhibits a preventive effect on sepsis in a septic model induced in rats with cecal ligation and puncture (CLP). Rats were randomly separated into groups, 10 rats in each: (i) a sham (control) group, (ii) an untreated sepsis group, (iii) a sepsis group treated with 5mg/kg tadalafil and (iv) a sepsis group treated with 10mg/kg tadalafil. A polymicrobial sepsis model was induced in rats using CLP. Rats were sacrificed after 16h, and blood and kidney tissues were collected for biochemical and histopathological study. Levels of the inflammatory parameter IL-6 decreased significantly in the sepsis groups receiving tadalafil in comparison with the untreated sepsis group (p kidney tissues decreased significantly in the sepsis groups receiving tadalafil compared to the untreated sepsis group (p kidney tissue of septic rats in a polymicrobial sepsis model induced with CLP. Copyright® by the International Brazilian Journal of Urology.

  8. Icariin protects rats against 5/6 nephrectomy-induced chronic kidney failure by increasing the number of renal stem cells.

    Science.gov (United States)

    Huang, Zhongdi; He, Liqun; Huang, Di; Lei, Shi; Gao, Jiandong

    2015-10-21

    Chronic kidney disease poses a serious health problem worldwide with increasing prevalence and lack of effective treatment. This study aimed to investigate the mechanism of icariin in alleviating chronic renal failure induced by 5/6 nephrectomy in rats. The chronic renal failure model was established by a two-phased 5/6 nephrectomy procedure. The model rats were given daily doses of water or icariin for 8 weeks. The kidney morphology was checked by HE staining. The levels of blood urea nitrogen, serum creatinine, and serum uric acid were measured by colometric methods. The expression of specified genes was analyzed by quantitative real-time PCR and immunohistochemical staining. The number of renal stem/progenitor cells was analyzed by CD133 and CD24 immunohistochemical staining. Icariin protected against CDK-caused damages to kidney histology and improved renal function, significantly reduced levels of BUN, creatinine, and uric acid. Icariin inhibited the expression level of TGF-β1 whereas upregulated HGF, BMP-7, WT-1, and Pax2 expression. Moreover, ccariin significantly increased the expression of CD24, CD133, Osr1, and Nanog in remnant kidney and the numbers of CD133(+)/CD24(+) renal stem/progenitor cells. These data demonstrated that icariin effectively alleviated 5/6 nephrectomy induced chronic renal failure through increasing renal stem/progenitor cells.

  9. Probing Extreme-density Matter with Gravitational-wave Observations of Binary Neutron Star Merger Remnants

    Energy Technology Data Exchange (ETDEWEB)

    Radice, David [Institute for Advanced Study, 1 Einstein Drive, Princeton, NJ 08540 (United States); Bernuzzi, Sebastiano [Department of Mathematical, Physical and Computer Sciences, University of Parma, I-43124 Parma (Italy); Pozzo, Walter Del [Dipartimento di Fisica “Enrico Fermi,” Università di Pisa, Pisa I-56127 (Italy); Roberts, Luke F. [NSCL/FRIB and Department of Physics and Astronomy, Michigan State University, 640 S Shaw Lane, East Lansing, MI 48824 (United States); Ott, Christian D. [TAPIR, Walter Burke Institute for Theoretical Physics, California Institute of Technology, 1200 E. California Boulevard, Pasadena, CA 91125 (United States)

    2017-06-20

    We present a proof-of-concept study, based on numerical-relativity simulations, of how gravitational waves (GWs) from neutron star merger remnants can probe the nature of matter at extreme densities. Phase transitions and extra degrees of freedom can emerge at densities beyond those reached during the inspiral, and typically result in a softening of the equation of state (EOS). We show that such physical effects change the qualitative dynamics of the remnant evolution, but they are not identifiable as a signature in the GW frequency, with the exception of possible black hole formation effects. The EOS softening is, instead, encoded in the GW luminosity and phase and is in principle detectable up to distances of the order of several megaparsecs with advanced detectors and up to hundreds of megaparsecs with third-generation detectors. Probing extreme-density matter will require going beyond the current paradigm and developing a more holistic strategy for modeling and analyzing postmerger GW signals.

  10. Endoscopic submucosal dissection training with ex vivo human gastric remnants.

    Science.gov (United States)

    Pham, David V; Shah, Anand; Borao, Frank J; Gorcey, Steven

    2014-01-01

    Endoscopic submucosal dissection (ESD) offers en bloc resection of early cancer or precancerous lesions, potentially saving patients from major organ resection, such as gastrectomy, colectomy, and esophagectomy. Japan now leads the world in ESD due to its high rate of gastric cancer. Western countries, with their lower gastric cancer rates, do not get as much experience with the technique. Training in ESD utilizing both in vivo and ex vivo porcine stomach has been shown to decrease rates of perforation and operative time. Both models can be prohibitively expensive or not generally available to the majority of endoscopists on a regular basis. This study describes the framework for using human gastric remnants from sleeve gastrectomy patients for ESD training. Patients undergoing sleeve gastrectomy for morbid obesity were consented for use of their gastric specimen before surgery. The specimen was weighed and measured by the pathologist and then used for ESD training. The specimen was mounted to a 15-mm laparoscopic port and secured using a pursestring suture. ESD was then performed through this port. We were able to successfully use this model to resect multiple marked out lesions in an en bloc fashion. Training using this model has improved our dissection times from approximately 2 h to 30 min for a 2-cm simulated lesion. ESD requires the endoscopist to perform a surgical dissection. Until now, development of these skills required intensive training on porcine models that are not widely available. We were able to create a method using the excised portion from sleeve gastrectomy patients, providing a more accessible and cost-effective model for ESD training and potentially other endoscopic therapeutic modalities.

  11. Complex structure of the supernova remnant HB 3

    Science.gov (United States)

    Leahy, D. A.; Venkatesan, D.; Long, K. S.; Naranan, S.

    1985-01-01

    HB 3 is an old, large (84 pc diameter) supernova remnant associated with the W3 H II region/molecular cloud complex. Observations of the imaging proportional counter (IPC) onboard the Einstein X-ray astronomy satellite have been reprocessed to yield a contour map of X-ray brightness and spectra of various regions of this remnant. The measured IPC flux is 2.4 x 10 to the -11th ergs per sq cm per s, giving a 0.2-4 keV luminosity of 1.6 x 10 to the 35th ergs/s for a column densityof 6 x 10 to the 21st per sq cm. The measured X-ray temperatures reveal a decrease from center to limb of the remnant of 1-0.3 keV. HB 3 is in the late adiabatic blast-wave phase of evolution, 30,000 to 50,000 yr old and with an initial blast energy of 3 x 10 to the 50th ergs. The X-ray map is compared with available radio and optical images. In X-rays, HB 3 has two components - a diffuse emission inside the 84 pc radio remnant and a ring of emission at the center of 30 pc in diameter. The diffuse emission is similar to that from other supernova remnants which are moderately obscured (column density, nH approximately 10 to the 22nd per sq cm). Three possibilities for the origin of the ring are explored: (1) a second supernova remnant, (2) a shocked shell in the interstellar medium surrounding HB 3, and (3) reverse-shock heated ejecta. There is no hot neutron star within the remnant.

  12. Immunosuppressive and remodelling properties of mesenchymal stem cells in a model of chronic kidney disease

    Directory of Open Access Journals (Sweden)

    Patricia Semedo

    2009-12-01

    Full Text Available Objective: To investigate the role of mesenchymal stem cells in fibrogenesis using a model of chronic renal insufficiency. Methods: Mesenchymal stem cells  were obtained from tibias and femurs of Wistar-EPM rats. After three to five passages, the cells were submitted to phenotypic analyses and differentiation. Wistar rats were submitted to the 5/6 nephrectomy model, and 2.105 mesenchymal stem cells  were administered intravenously to each rat every two weeks until the eighth week. Rresults: Sex-determining region Y was observed in female rats treated with stem cells. Serum and urine analyses showed improvement of functional parameters in mesenchymal stem cells treated animals, such as creatinine, serum urea, and proteinuria. Moreover, hemocrit analysis showed improvement of anemia in mesenchymal stem cells treated animals. Masson’s Trichromium and Picrosirius Red staining demonstrated reduced levels of fibrosis in mesenchymal stem cells treated in animals. These results were corroborated by reduced vimentin, collagen I, TGFβ, FSP-1, MCP-1 and Smad3 mRNA expression. Renal IL-6 and TNFα mRNA expression levels were significantly decreased after mesenchymal stem cells treatment, while IL-4 and IL-10 expression were increased. Serum expression of IL-1α, IL-1β, IL-6, IFN-γ, TNF-α, and IL-10 was decreased in mesenchymal cell-treated animals. Cconclusions: Altogether, these results suggest that mesenchymal stem cells therapy can indeed modulate the inflammatory response that follows the initial phase of a chronic renal lesion. The immunosuppresive and remodeling properties of the mesenchymal stem cells  may be involved in the improved fibrotic outcome.

  13. ‘I Was a Model Student’: Illness Knowledge Seeking and Self-care Among Finnish Kidney Recipients

    Directory of Open Access Journals (Sweden)

    Susanne Ådahl

    2012-11-01

    Full Text Available The customer based ideology currently in use in the Finnish welfare state, as elsewhere, has transformed health care. Responsibility for health, that used to be lodged within society, has become the responsibility of the individual. Self-care is part of this growing trend, where there is an inherent assumption that informed patients are more capable of making decisions about their medical regime, which in turn empowers them. Finnish kidney transplant recipients are, through various sources and forms of health information, encouraged to follow the moral imperative of engaging in certain types of health maintaining behaviour that safeguards the transplant kidney. Being informed and sharing illness related information with peers is a manner of showing gratitude towards the state; a way to, in some fashion, reciprocating the valuable gift of a kidney through caring. Taking my lead from Mol’s (2008 notion of care as a practice, as something that is done by all those involved in giving care, I ask how knowledge seeking and sharing on illness can be a form of self-caring. The aim of the article is, thus, to discuss what role illness-related information has in the process of caring for kidney failure. The data consists of in-depth interviews with 18 kidney transplant recipients narrating their illness trajectory, and additional information solicited on a number of central themes, two of which were the access to illness-related information and involvement in peer support activities.

  14. Evidence for the Stochastic Acceleration of Secondary Antiprotons by Supernova Remnants

    Energy Technology Data Exchange (ETDEWEB)

    Cholis, Ilias [Johns Hopkins U.; Hooper, Dan [Chicago U., KICP; Linden, Tim [Ohio State U.

    2017-01-16

    The antiproton-to-proton ratio in the cosmic-ray spectrum is a sensitive probe of new physics. Using recent measurements of the cosmic-ray antiproton and proton fluxes in the energy range of 1-1000 GeV, we study the contribution to the $\\bar{p}/p$ ratio from secondary antiprotons that are produced and subsequently accelerated within individual supernova remnants. We consider several well-motivated models for cosmic-ray propagation in the interstellar medium and marginalize our results over the uncertainties related to the antiproton production cross section and the time-, charge-, and energy-dependent effects of solar modulation. We find that the increase in the $\\bar{p}/p$ ratio observed at rigidities above $\\sim$ 100 GV cannot be accounted for within the context of conventional cosmic-ray propagation models, but is consistent with scenarios in which cosmic-ray antiprotons are produced and subsequently accelerated by shocks within a given supernova remnant. In light of this, the acceleration of secondary cosmic rays in supernova remnants is predicted to substantially contribute to the cosmic-ray positron spectrum, accounting for a significant fraction of the observed positron excess.

  15. Pervasive defaunation of forest remnants in a tropical biodiversity hotspot.

    Science.gov (United States)

    Canale, Gustavo R; Peres, Carlos A; Guidorizzi, Carlos E; Gatto, Cassiano A Ferreira; Kierulff, Maria Cecília M

    2012-01-01

    Tropical deforestation and forest fragmentation are among the most important biodiversity conservation issues worldwide, yet local extinctions of millions of animal and plant populations stranded in unprotected forest remnants remain poorly explained. Here, we report unprecedented rates of local extinctions of medium to large-bodied mammals in one of the world's most important tropical biodiversity hotspots. We scrutinized 8,846 person-years of local knowledge to derive patch occupancy data for 18 mammal species within 196 forest patches across a 252,669-km(2) study region of the Brazilian Atlantic Forest. We uncovered a staggering rate of local extinctions in the mammal fauna, with only 767 from a possible 3,528 populations still persisting. On average, forest patches retained 3.9 out of 18 potential species occupancies, and geographic ranges had contracted to 0-14.4% of their former distributions, including five large-bodied species that had been extirpated at a regional scale. Forest fragments were highly accessible to hunters and exposed to edge effects and fires, thereby severely diminishing the predictive power of species-area relationships, with the power model explaining only ~9% of the variation in species richness per patch. Hence, conventional species-area curves provided over-optimistic estimates of species persistence in that most forest fragments had lost species at a much faster rate than predicted by habitat loss alone.

  16. Pervasive defaunation of forest remnants in a tropical biodiversity hotspot.

    Directory of Open Access Journals (Sweden)

    Gustavo R Canale

    Full Text Available Tropical deforestation and forest fragmentation are among the most important biodiversity conservation issues worldwide, yet local extinctions of millions of animal and plant populations stranded in unprotected forest remnants remain poorly explained. Here, we report unprecedented rates of local extinctions of medium to large-bodied mammals in one of the world's most important tropical biodiversity hotspots. We scrutinized 8,846 person-years of local knowledge to derive patch occupancy data for 18 mammal species within 196 forest patches across a 252,669-km(2 study region of the Brazilian Atlantic Forest. We uncovered a staggering rate of local extinctions in the mammal fauna, with only 767 from a possible 3,528 populations still persisting. On average, forest patches retained 3.9 out of 18 potential species occupancies, and geographic ranges had contracted to 0-14.4% of their former distributions, including five large-bodied species that had been extirpated at a regional scale. Forest fragments were highly accessible to hunters and exposed to edge effects and fires, thereby severely diminishing the predictive power of species-area relationships, with the power model explaining only ~9% of the variation in species richness per patch. Hence, conventional species-area curves provided over-optimistic estimates of species persistence in that most forest fragments had lost species at a much faster rate than predicted by habitat loss alone.

  17. Pervasive Defaunation of Forest Remnants in a Tropical Biodiversity Hotspot

    Science.gov (United States)

    Canale, Gustavo R.; Peres, Carlos A.; Guidorizzi, Carlos E.; Gatto, Cassiano A. Ferreira; Kierulff, Maria Cecília M.

    2012-01-01

    Tropical deforestation and forest fragmentation are among the most important biodiversity conservation issues worldwide, yet local extinctions of millions of animal and plant populations stranded in unprotected forest remnants remain poorly explained. Here, we report unprecedented rates of local extinctions of medium to large-bodied mammals in one of the world's most important tropical biodiversity hotspots. We scrutinized 8,846 person-years of local knowledge to derive patch occupancy data for 18 mammal species within 196 forest patches across a 252,669-km2 study region of the Brazilian Atlantic Forest. We uncovered a staggering rate of local extinctions in the mammal fauna, with only 767 from a possible 3,528 populations still persisting. On average, forest patches retained 3.9 out of 18 potential species occupancies, and geographic ranges had contracted to 0–14.4% of their former distributions, including five large-bodied species that had been extirpated at a regional scale. Forest fragments were highly accessible to hunters and exposed to edge effects and fires, thereby severely diminishing the predictive power of species-area relationships, with the power model explaining only ∼9% of the variation in species richness per patch. Hence, conventional species-area curves provided over-optimistic estimates of species persistence in that most forest fragments had lost species at a much faster rate than predicted by habitat loss alone. PMID:22905103

  18. Kidney Cancer in Children

    Science.gov (United States)

    What is Kidney Cancer in Children? Kidney (renal) tumors are very rare in children. Still, the three most common renal tumors ... treatable and curable. What are the Types of Kidney Cancer in Children? Male urinary tract Medical Illustration ...

  19. Diabetic Kidney Problems

    Science.gov (United States)

    ... too high. Over time, this can damage your kidneys. Your kidneys clean your blood. If they are damaged, waste ... in your blood instead of leaving your body. Kidney damage from diabetes is called diabetic nephropathy. It ...

  20. Testing for Kidney Disease

    Science.gov (United States)

    ... hypertension artérielle Heart Disease Mineral & Bone Disorder Chronic Kidney Disease Tests & Diagnosis How can I tell if I have kidney disease? Early kidney disease usually doesn’t have any ...

  1. Chronic Kidney Disease

    Science.gov (United States)

    ... help control blood pressure, and make hormones. Chronic kidney disease (CKD) means that your kidneys are damaged and ... people don't have any symptoms until their kidney disease is very advanced. Blood and urine tests are ...

  2. Clinical Risk Scoring Models for Prediction of Acute Kidney Injury after Living Donor Liver Transplantation: A Retrospective Observational Study.

    Directory of Open Access Journals (Sweden)

    Mi Hye Park

    Full Text Available Acute kidney injury (AKI is a frequent complication of liver transplantation and is associated with increased mortality. We identified the incidence and modifiable risk factors for AKI after living-donor liver transplantation (LDLT and constructed risk scoring models for AKI prediction. We retrospectively reviewed 538 cases of LDLT. Multivariate logistic regression analysis was used to evaluate risk factors for the prediction of AKI as defined by the RIFLE criteria (RIFLE = risk, injury, failure, loss, end stage. Three risk scoring models were developed in the retrospective cohort by including all variables that were significant in univariate analysis, or variables that were significant in multivariate analysis by backward or forward stepwise variable selection. The risk models were validated by way of cross-validation. The incidence of AKI was 27.3% (147/538 and 6.3% (34/538 required postoperative renal replacement therapy. Independent risk factors for AKI by multivariate analysis of forward stepwise variable selection included: body-mass index >27.5 kg/m2 [odds ratio (OR 2.46, 95% confidence interval (CI 1.32-4.55], serum albumin 20 (OR 2.01, 95%CI 1.17-3.44, operation time >600 min (OR 1.81, 95%CI 1.07-3.06, warm ischemic time >40 min (OR 2.61, 95%CI 1.55-4.38, postreperfusion syndrome (OR 2.96, 95%CI 1.55-4.38, mean blood glucose during the day of surgery >150 mg/dl (OR 1.66, 95%CI 1.01-2.70, cryoprecipitate > 6 units (OR 4.96, 95%CI 2.84-8.64, blood loss/body weight >60 ml/kg (OR 4.05, 95%CI 2.28-7.21, and calcineurin inhibitor use without combined mycophenolate mofetil (OR 1.87, 95%CI 1.14-3.06. Our risk models performed better than did a previously reported score by Utsumi et al. in our study cohort. Doses of calcineurin inhibitor should be reduced by combined use of mycophenolate mofetil to decrease postoperative AKI. Prospective randomized trials are required to address whether artificial modification of hypoalbuminemia, hyperglycemia

  3. An experimental and numerical study of the flow and mass transfer in a model of the wearable artificial kidney dialyzer

    Science.gov (United States)

    2010-01-01

    Background Published studies of the past decades have established that mass transfer across the dialyzer membrane is governed by diffusion, convection and osmosis. While the former is independent of the pressure in the liquids, the latter two are pressure dependent and are enhanced when the pressure difference across the membrane is increased. The goal of the present study is to examine the impact of pulsatile flow on the transport phenomena across the membrane of a high-flux dialyzer in a wearable artificial kidney (WAK) with a novel single small battery-operated pulsatile pump that drives both the blood and dialysate in a counter-phased manner, maximizing the trans-membrane pressure. Methods Both in-vitro experimental and numerical tools are employed to compare the performance of the pulsatile WAK dialyzer with a traditional design of a single-channel roller blood pump together with a centrifugal pump that drives the dialysate flow. The numerical methods utilize the axisymmetric Navier-Stokes and mass transfer equations to model the flow in the fibers of the dialyzer. Results While diffusion is still the dominating transport regime, the WAK pump enhances substantially the trans-membrane pressure and thus increases mass convection that might be as high as 30% of the overall transfer. This increase is obtained due to the design of the pulsatile WAK pump that increases ultrafiltration by increasing the trans-membrane pressure. Conclusions The experimental and numerical results revealed that when pumping at similar flow rates, a small battery-operated pulsatile pump provides clearances of urea and creatinine similar as or better than a large heavy AC-powered roller pump. PMID:20497572

  4. Evaluation of Early Kidney Damage Caused by Brain Death Using Real-Time Ultrasound Elastography in a Bama Pig Model.

    Science.gov (United States)

    Tang, Ying; Zhao, Jingwen; Liu, Dongyang; Niu, Ningning; Yu, Huimin

    2017-10-01

    The aim of this study was to investigate the value of real-time tissue elastography (RTE) in the evaluation of early graft damage resulting from brain death. We performed RTE before and 0, 3, 6 and 9 h after brain death in a Bama pig model. Eleven RTE parameters were compared among time groups, and their correlations with electron microscopic findings were analyzed. Receiver operating characteristic curve analysis was used to find the RTE parameter cutoff values. The mean relative strain value within the region of interest (MEAN), standard deviation of the relative strain value within the region of interest (SD), percentage area of low strain within the region of interest (%AREA), complexity of low-strain area within the region of interest (COMP), kurtosis (KURT), skewness (SKEW), contrast (CONT) and entropy (ENT) and inverse difference moment (IDM) differed statistically significantly between groups (p < 0.05). Electron microscopy of kidney tissue revealed that irreversible damage gradually occurred with longer brain death duration and was marked at 9 h (p < 0.05). These findings correlated best with MEAN (r = 0.632, p < 0.05). Receiver operating characteristic curve analysis of RTE parameters identified a cutoff value of 63.43 for MEAN for optimal diagnostic performance. RTE allows non-invasive, preliminary evaluation of early renal graft damage resulting from brain death. Copyright © 2017 World Federation for Ultrasound in Medicine & Biology. Published by Elsevier Inc. All rights reserved.

  5. An experimental and numerical study of the flow and mass transfer in a model of the wearable artificial kidney dialyzer

    Directory of Open Access Journals (Sweden)

    Rosenfeld Moshe

    2010-05-01

    Full Text Available Abstract Background Published studies of the past decades have established that mass transfer across the dialyzer membrane is governed by diffusion, convection and osmosis. While the former is independent of the pressure in the liquids, the latter two are pressure dependent and are enhanced when the pressure difference across the membrane is increased. The goal of the present study is to examine the impact of pulsatile flow on the transport phenomena across the membrane of a high-flux dialyzer in a wearable artificial kidney (WAK with a novel single small battery-operated pulsatile pump that drives both the blood and dialysate in a counter-phased manner, maximizing the trans-membrane pressure. Methods Both in-vitro experimental and numerical tools are employed to compare the performance of the pulsatile WAK dialyzer with a traditional design of a single-channel roller blood pump together with a centrifugal pump that drives the dialysate flow. The numerical methods utilize the axisymmetric Navier-Stokes and mass transfer equations to model the flow in the fibers of the dialyzer. Results While diffusion is still the dominating transport regime, the WAK pump enhances substantially the trans-membrane pressure and thus increases mass convection that might be as high as 30% of the overall transfer. This increase is obtained due to the design of the pulsatile WAK pump that increases ultrafiltration by increasing the trans-membrane pressure. Conclusions The experimental and numerical results revealed that when pumping at similar flow rates, a small battery-operated pulsatile pump provides clearances of urea and creatinine similar as or better than a large heavy AC-powered roller pump.

  6. Selected renal cells modulate disease progression in rodent models of chronic kidney disease via NF-κB and TGF-β1 pathways.

    Science.gov (United States)

    Bruce, Andrew T; Ilagan, Roger M; Guthrie, Kelly I; Rivera, Elias; Choudhury, Sumana; Sangha, Namrata; Spencer, Thomas; Bertram, Timothy A; Jain, Deepak; Kelley, Russell W; Basu, Joydeep

    2015-01-01

    Identification of mechanistic pathways for selected renal cell (SRC) therapeutic bioactivity in rodent models of chronic kidney disease. In vivo and in vitro functional bioassays applied to investigate regenerative outcomes associated with delivery of SRC to diseased rodent kidney. In vivo, SRC reduces chronic infiltration by monocytes/macrophages. SRC attenuates NF-κB and PAI-1 responses while simultaneously promoting host tubular cell expansion through trophic cues. In vitro, SRC-derived conditioned media attenuates TNF-α-induced NF-κB response, TGF-β-mediated PAI-1 response and increases expression of transcripts associated with cell cycle regulation. Observed bioactive responses were from vesicle and nonvesicle-associated factors, including specific miRNAs. We identify a paracrine mechanism for SRC immunomodulatory and trophic cues on host renal tissues, catalyzing long-term functional benefits in vivo.

  7. A cross-platform metabolomics workflow for volume-restricted tissue samples: application to an animal model for polycystic kidney disease.

    Science.gov (United States)

    Sánchez-López, E; Happé, H; Steenvoorden, E; Crego, A L; Marina, M L; Peters, D J M; Mayboroda, O A

    2017-09-26

    Metabolic profiling provides an unbiased view of the physiological status of an organism as a "function" of the metabolic composition of a measured sample. Here, we propose a simple LC-MS based workflow for metabolic profiling of volume-restricted samples, namely individual 20 μm-thick histological sections of a mouse kidney. The main idea of this workflow is to re-use the material after an RPLC-MS run, namely using the volume remaining in the vial after injection, and then introducing a phase changing step to enable HILIC-MS analysis. To test the applicability of the workflow and its ability to extract valuable biological information, we applied it to an animal model of polycystic kidney disease (PKD).

  8. Increased retention of americium in kidneys as compared with plutonium in an actinide wound contamination model in the rat.

    Science.gov (United States)

    Griffiths, Nina M; Coudert, Sylvie; Molina, Thibaut; Wilk, Jean-Claude; Renault, Daniel; Berard, Philippe; Van der Meeren, Anne

    2014-11-01

    Americium-241 ((241)Am) presents a potential risk for nuclear industry workers associated with reactor decommissioning and aging combustible materials. The purpose of this study was to investigate Am renal retention after actinide contamination by wounding in the rat. Anesthetized rats were contaminated with Mixed Oxide (MOX) (7.1% Plutonium [Pu] by mass and containing 27% Am as % total alpha activity), Pu or Am nitrate following an incision wound of the hind leg. Times of euthanasia ranged from 2 hours to 5 months after contamination. Pu and Am levels were quantified following radiochemistry and alpha-spectrophotometry. Initial data show that over the experimental period the proportion of Am in kidneys as a fraction of total kidney alpha activity was elevated as compared to MOX powder indicating a specific retention in this organ. The percentage of Pu was similar to the powder. After MOX contamination, kidney to liver ratios appeared to increase more markedly for Am (from 0.2 at 7 days to 0.6 at 90 days) as compared with Pu (0.1 at 7 days to 0.2 at 90 days). In accordance with tissue actinide retention the dose from Am to the kidney increases with time. For comparison, the ratio of estimated equivalent doses due to Am to kidney is 1.5-fold greater than for Pu (around 90 versus 60 mSv). After actinide contamination of wounds, Am is concentrated in the kidneys as compared to Pu leading to potential exposure of renal tissue to both alpha particles and gamma radiation.

  9. Nuclear envelope remnants: fluid membranes enriched in sterols and polyphosphoinositides.

    Directory of Open Access Journals (Sweden)

    Marie Garnier-Lhomme

    Full Text Available The cytoplasm of eukaryotic cells is a highly dynamic compartment where membranes readily undergo fission and fusion to reorganize the cytoplasmic architecture, and to import, export and transport various cargos within the cell. The double membrane of the nuclear envelope that surrounds the nucleus, segregates the chromosomes from cytoplasm and regulates nucleocytoplasmic transport through pores. Many details of its formation are still unclear. At fertilization the sperm devoid of nuclear envelope pores enters the egg. Although most of the sperm nuclear envelope disassembles, remnants of the envelope at the acrosomal and centriolar fossae do not and are subsequently incorporated into the newly forming male pronuclear envelope. Remnants are conserved from annelid to mammalian sperm.Using lipid mass spectrometry and a new application of deuterium solid-state NMR spectroscopy we have characterized the lipid composition and membrane dynamics of the sperm nuclear envelope remnants in isolated sperm nuclei.We report nuclear envelope remnants are relatively fluid membranes rich in sterols, devoid of sphingomyelin, and highly enriched in polyphosphoinositides and polyunsaturated phospholipids. The localization of the polybasic effector domain of MARCKS illustrates the non-nuclear aspect of the polyphosphoinositides. Based on their atypical biophysical characteristics and phospholipid composition, we suggest a possible role for nuclear envelope remnants in membrane fusion leading to nuclear envelope assembly.

  10. Should we use standard survival models or the illness-death model for interval-censored data to investigate risk factors of chronic kidney disease progression?

    Science.gov (United States)

    Boucquemont, Julie; Metzger, Marie; Combe, Christian; Stengel, Bénédicte; Leffondre, Karen

    2014-01-01

    In studies investigating risk factors of chronic kidney disease (CKD) progression, one may be interested in estimating factors effects on both a fall of glomerular filtration rate (GFR) below a specific level (i.e., a CKD stage) and death. Such studies have to account for the fact that GFR is measured at intermittent visit only, which implies that progression to the stage of interest is unknown for patients who die before being observed at that stage. Our objective was to compare the results of an illness-death model that handles this uncertainty, with frequently used survival models. This study included 1,519 patients from the NephroTest cohort with CKD stages 1-4 at baseline (69% males, 59±15 years, median protein/creatinine ratio [PCR] 27.4 mg/mmol) and subsequent annual measures of GFR (follow-up time 4.3±2.7 years). Each model was used to estimate the effects of sex, age, PCR, and GFR at baseline on the hazards of progression to CKD stage 5 (GFRmodels. The differences between results were higher for the hazard of death before or after progression. Our results also suggest that previous findings on the effect of age on end-stage renal disease are more likely due to a strong impact of age on death than to an effect on progression. The probabilities of progression were systematically under-estimated with the survival model as compared with the illness-death model. This study illustrates the advantages of the illness-death model for accurately estimating the effects of risk factors on the hazard of progression and death, and probabilities of progression. It avoids the need to choose arbitrary time-to-event and time-to-censoring, while accounting for both interval censoring and competition by death, using a single analytical model.

  11. Kidneys and How They Work

    Science.gov (United States)

    ... English English Español Section Navigation Kidney Disease Acquired Cystic Kidney Disease Amyloidosis & Kidney Disease Chronic Kidney Disease (CKD) What ... Eating, Diet, & Nutrition for PKD Race, Ethnicity, & Kidney Disease Renal Artery ... Kidney Cysts Solitary Kidney Your Kidneys & How They Work Your ...

  12. A progenitor binary and an ejected mass donor remnant of faint type Ia supernovae

    Science.gov (United States)

    Geier, S.; Marsh, T. R.; Wang, B.; Dunlap, B.; Barlow, B. N.; Schaffenroth, V.; Chen, X.; Irrgang, A.; Maxted, P. F. L.; Ziegerer, E.; Kupfer, T.; Miszalski, B.; Heber, U.; Han, Z.; Shporer, A.; Telting, J. H.; Gänsicke, B. T.; Østensen, R. H.; O'Toole, S. J.; Napiwotzki, R.

    2013-06-01

    Type Ia supernovae (SN Ia) are the most important standard candles for measuring the expansion history of the universe. The thermonuclear explosion of a white dwarf can explain their observed properties, but neither the progenitor systems nor any stellar remnants have been conclusively identified. Underluminous SN Ia have been proposed to originate from a so-called double-detonation of a white dwarf. After a critical amount of helium is deposited on the surface through accretion from a close companion, the helium is ignited causing a detonation wave that triggers the explosion of the white dwarf itself. We have discovered both shallow transits and eclipses in the tight binary system CD-30°11223 composed of a carbon/oxygen white dwarf and a hot helium star, allowing us to determine its component masses and fundamental parameters. In the future the system will transfer mass from the helium star to the white dwarf. Modelling this process we find that the detonation in the accreted helium layer is sufficiently strong to trigger the explosion of the core. The helium star will then be ejected at such high velocity that it will escape the Galaxy. The predicted properties of this remnant are an excellent match to the so-called hypervelocity star US 708, a hot, helium-rich star moving at more than 750 km s-1, sufficient for it to leave the Galaxy. The identification of both progenitor and remnant provides a consistent picture of the formation and evolution of underluminous SNIa.

  13. The unorthodox evolution of major merger remnants into star-forming spiral galaxies

    Science.gov (United States)

    Sparre, Martin; Springel, Volker

    2017-10-01

    Galaxy mergers are believed to play a key role in transforming star-forming disc galaxies into quenched ellipticals. Most of our theoretical knowledge about such morphological transformations does, however, rely on idealized simulations where processes such as cooling of hot halo gas into the disc and gas accretion in the post-merger phase are not treated in a self-consistent cosmological fashion. In this paper, we study the morphological evolution of the stellar components of four major mergers occurring at z = 0.5 in cosmological hydrodynamical zoom simulations. In all simulations, the merger reduces the disc mass fraction, but all galaxies simulated at our highest resolution regrow a significant disc by z = 0 (with a disc fraction larger than 24 per cent). For runs with our default physics model, which includes galactic winds from star formation and black hole feedback, none of the merger remnants are quenched, but in a set of simulations with stronger black hole feedback, we find that major mergers can indeed quench galaxies. We conclude that major merger remnants commonly evolve into star-forming disc galaxies, unless sufficiently strong active galactic nucleus feedback assists in the quenching of the remnant.

  14. THE {sup 7}Li/{sup 6}Li ISOTOPE RATIO NEAR THE SUPERNOVA REMNANT IC 443

    Energy Technology Data Exchange (ETDEWEB)

    Taylor, C. J.; Ritchey, A. M.; Federman, S. R. [Department of Physics and Astronomy, University of Toledo, Toledo, OH 43606 (United States); Lambert, D. L., E-mail: corbin.taylor@rockets.utoledo.edu, E-mail: steven.federman@utoledo.edu, E-mail: aritchey@astro.washington.edu, E-mail: dll@astro.as.utexas.edu [W. J. McDonald Observatory, University of Texas at Austin, Austin, TX 78712 (United States)

    2012-05-01

    We present an analysis of {sup 7}Li/{sup 6}Li isotope ratios along four sight lines that probe diffuse molecular gas near the supernova remnant IC 443. Recent gamma-ray observations have revealed the presence of shock-accelerated cosmic rays interacting with the molecular cloud surrounding the remnant. Our results indicate that the {sup 7}Li/{sup 6}Li ratio is lower in regions more strongly affected by these interactions, a sign of recent Li production by cosmic rays. We find that {sup 7}Li/{sup 6}Li Almost-Equal-To 7 toward HD 254755, which is located just outside the visible edge of IC 443, while {sup 7}Li/{sup 6}Li Almost-Equal-To 3 along the line of sight to HD 43582, which probes the interior region of the supernova remnant. No evidence of {sup 7}Li synthesis by neutrino-induced spallation is found in material presumably contaminated by the ejecta of a core-collapse supernova. The lack of a neutrino signature in the {sup 7}Li/{sup 6}Li ratios near IC 443 is consistent with recent models of Galactic chemical evolution, which suggest that the {nu}-process plays only a minor role in Li production.

  15. SN 185 and its Remnant RCW 86: A Type Ia Explosion within a Bubble?

    Science.gov (United States)

    Borkowski, Kazimierz; Blair, William; Ghavamian, Parviz; Long, Knox; Raymond, John; Reynolds, Stephen; Rho, Jeonghee; Williams, Brian; Winkler, P. Frank

    2008-03-01

    The bright guest star of AD185 is the earliest recorded historical supernova (SN), but its remnant has only recently been firmly identified with RCW 86 with help of X-rays and very high energy (VHE) Gamma-rays. RCW 86 is unlike any other historical SN, implicating a Type Ia explosion within a wind-blown bubble. X-ray synchrotron emission and VHE Gamma-rays are produced by relativistic particles accelerated in fast (several thousand km/s) shocks that are present in RCW 86, while slower radiative and nonradiative shocks are driven into the dusty shell swept up by the SN progenitor. We propose Spitzer observations of RCW 86, that will allow us to determine dust properties and physical conditions within both slow and fast shocks. We will determine shock densities in the whole remnant using MIPS imaging at 24 and 70 microns. This will allow us to finally determine whether VHE emission arises from relativistic electrons or from cosmic ray protons accelerated by the SN shock. We will also determine how acceleration of synchrotron-emitting electrons to TeV energies depends on the shock density. We propose IRS spectral mapping in two very different regions of the remnant to perform a more detailed and sensitive study of dust emission and dust destruction under differing plasma conditions, and of line emission produced by radiative shocks. This will also verify the results of the imaging observations, and will allow for quantitative comparison with models for dust emission and destruction in SN shocks. We request imaging with IRAC in the brightest region of the remnant to map emission from the hottest, transiently heated small grains, and to determine their destruction rates. Physical properties and dust content within the shell swept up by the RCW 86 progenitor will help us to constrain the pre-SN evolution of a Type Ia progenitor, a significant step toward understanding of progenitors of thermonuclear explosions.

  16. Black Hole Remnants and the Information Loss Paradox

    CERN Document Server

    Chen, Pisin; Yeom, Dong-han

    2014-01-01

    Forty years after the discovery of Hawking radiation, its exact nature remains elusive. If Hawking radiation does not carry any information out from the ever shrinking black hole, it seems that unitarity is violated once the black hole completely evaporates. On the other hand, attempts to recover information via quantum entanglement lead to the firewall controversy. Amid the confusions, the possibility that black hole evaporation stops with a "remnant" has remained unpopular and is often dismissed due to some "undesired properties" of such an object. Nevertheless, as in any scientific debate, the pros and cons of any proposal must be carefully scrutinized. We fill in the void of the literature by providing a timely review of various types of black hole remnants, and provide some new thoughts regarding the challenges that black hole remnants face in the context of information loss paradox and its latest incarnation, namely the firewall controversy. The importance of understanding the role of curvature singular...

  17. Dose-Titrated Vasopressin V2 Receptor Antagonist Improves Renoprotection in a Mouse Model for Autosomal Dominant Polycystic Kidney Disease

    NARCIS (Netherlands)

    Zittema, Debbie; Versteeg, Irina B.; Gansevoort, Ron T.; van Goor, Harry; de Heer, Emile; Veraar, Kimberley A. M.; Peters, Dorien J. M.; Meijer, Esther

    2016-01-01

    Background: In autosomal dominant polycystic kidney disease, renoprotective treatment with a vasopressin V2 receptor antagonist (V2RA) is given in a fixed dose (FD). Disease progression and drug habituation could diminish treatment efficacy. We investigated whether the renoprotective effect of the

  18. Establishment of Simple and Routine Methods in Early Diagnosis of Gentamicin-Induced Kidney Injury Based on a Rat Model

    Directory of Open Access Journals (Sweden)

    Cuiyan Liu

    2016-01-01

    Full Text Available The changes in biomarkers of gentamycin- (GM- induced kidney injury have been studied by using simple and routine methods and also assessed the efficacy and utility of these routine biomarkers in early diagnosis. Eighty Sprague-Dawley (SD rats were randomly divided into 4 groups: three experimental groups treated with different GM dosages (4, 20, and 100 mg·kg−1 and a control group. The experimental groups were given intramuscular GM injections once daily for 14 days, and the control group was given intramuscular sterile water. Blood and urine samples were collected on treatment days 1, 3, 7, and 14 to test for total protein (TP, albumin (ALB, blood urea nitrogen (BUN, creatinine (CRE, uric acid (UA, pH, specific gravity (SG, proteins (PRO, and cells in urinary sediment. Histopathology and kidney coefficient were performed on excised kidney specimens. The result indicated that serum CRE, BUN, and TP, urine PRO, and urinary hyaline casts and low-transitional epithelium showed an immediate and highly sensitive response to kidney injury, and the combined diagnosis with the above methods could be used in early diagnosis. Particularly, the process of the test was simple and quick, no special equipment, so it is more suit for primary medical institution.

  19. Establishment of Simple and Routine Methods in Early Diagnosis of Gentamicin-Induced Kidney Injury Based on a Rat Model.

    Science.gov (United States)

    Liu, Cuiyan; Kang, Youxi; Zhang, Huiqin; Zhu, Long; Yu, Hai; Han, Chunyang

    2016-01-01

    The changes in biomarkers of gentamycin- (GM-) induced kidney injury have been studied by using simple and routine methods and also assessed the efficacy and utility of these routine biomarkers in early diagnosis. Eighty Sprague-Dawley (SD) rats were randomly divided into 4 groups: three experimental groups treated with different GM dosages (4, 20, and 100 mg·kg(-1)) and a control group. The experimental groups were given intramuscular GM injections once daily for 14 days, and the control group was given intramuscular sterile water. Blood and urine samples were collected on treatment days 1, 3, 7, and 14 to test for total protein (TP), albumin (ALB), blood urea nitrogen (BUN), creatinine (CRE), uric acid (UA), pH, specific gravity (SG), proteins (PRO), and cells in urinary sediment. Histopathology and kidney coefficient were performed on excised kidney specimens. The result indicated that serum CRE, BUN, and TP, urine PRO, and urinary hyaline casts and low-transitional epithelium showed an immediate and highly sensitive response to kidney injury, and the combined diagnosis with the above methods could be used in early diagnosis. Particularly, the process of the test was simple and quick, no special equipment, so it is more suit for primary medical institution.

  20. Renoprotective Effects of DNAse-I Treatment in a Rat Model of Ischemia/Reperfusion-Induced Acute Kidney Injury.

    Science.gov (United States)

    Peer, Victoria; Abu Hamad, Ramzia; Berman, Sylvia; Efrati, Shai

    2016-01-01

    Massive DNA destruction/accumulation of cell-free DNA debris is a sensitive biomarker of progressive organ/tissue damage. Deleterious consequences of DNA debris accumulation are evident in cardiac ischemia, thrombosis, auto-inflammatory diseases, SLE-induced lupus nephritis and cystic fibrosis. In case of renal pathologies, degradation and elimination of DNA debris are suppressed, due to downregulated DNAse-I activity within the diseased kidneys. The aim of the current study was to evaluate whether exogenous DNAse-I administration might exert renoprotective effects in the setting of acute kidney injury (AKI or acute renal failure). Sprague-Dawley rats underwent unilateral nephrectomy, with simultaneous clamping of contralateral kidney artery. The treated group received DNAse-I injection before discontinuing anesthesia. Positive (ischemic) controls received saline injection. Negative (non-ischemic) controls were either non-operated or subjected to surgery of similar duress and duration without ischemia. Renal perfusion was evaluated using the Laser-Doppler technique. Blood was procured for evaluating DNAse-I activity, renal functioning, renal perfusion. The kidneys were allocated for histopathologic examinations and for the evaluation of renal hypoxia, intra-renal apoptosis and proliferation. Contrary to the situation in untreated ischemic rats, renal perfusion was significantly improved in DNAse-treated animals, concomitantly with significant amelioration of damage to renal functioning and tissue integrity. Treatment with DNAse-I significantly decreased the ischemia-induced renal hypoxia and apoptosis, simultaneously stimulating renal cell proliferation. Exogenous DNAse-I administration accelerated the clearance of intra-renal apoptotic DNA debris. Functional/histologic hallmarks of renal injury were ameliorated, renal functioning improved, intra-renal hypoxia decreased and intra-renal regeneration processes were activated. Thus, DNAse-I treatment protected the

  1. [Diagnosis and minimally invasive treatment of gastric remnant cancer].

    Science.gov (United States)

    Wu, Ai-wen; Ji, Jia-fu

    2013-02-01

    Gastric remnant cancer (GRC) is defined as cancer in the remnant stomach after partial gastrectomy. The incidence of GRC is rising in recent years. The carcinogenesis, development, and metastasis of GRC are different from primary gastric cancer. The early detection of GRC should be based on rational surveillance of patients following gastrectomy. For early stage GRC, endoscopic resection is one of the safe and effective methods. For advanced GRC, the primary treatment alternative is surgical resection. Minimally invasive procedures such as laparoscopic exploration, laparoscopic-assisted resection of GRC are still safe choices for experienced surgeons.

  2. Remnant Symmetry, Propagation and Evolution in f(T) Gravity

    CERN Document Server

    Chen, Pisin; Nester, James M; Ong, Yen Chin

    2014-01-01

    It was recently argued that f(T) gravity could inherit "remnant symmetry" from the full Lorentz group, despite the fact that the theory is not locally Lorentz invariant. Confusion has arisen regarding the implication of this result for the previous works, which established that f(T) gravity is pathological due to superluminal propagation, local acausality, and non-unique time evolution. We clarify that the existence of the "remnant group" does not rid the theory of these various problems, but instead strongly supports it.

  3. Lutein attenuates oxidative stress markers and ameliorates glucose homeostasis through polyol pathway in heart and kidney of STZ-induced hyperglycemic rat model.

    Science.gov (United States)

    Sharavana, Gurunathan; Joseph, G S; Baskaran, Vallikannan

    2017-12-01

    Lutein's role on chronic hyperglycemia-induced oxidative stress and associated glucose homeostasis in heart and kidney is limited. Purpose of the study is to investigate the effect of lutein on cardiac and renal polyol pathway enzymes and oxidative stress markers under hyperglycemia-induced oxidative stress condition using streptozotocin (STZ)-injected rat model. STZ-induced hyperglycemic (fasting blood glucose ≥11 mM) male Wistar rats were divided into two groups (n = 11/group). Group 1 received micellar lutein (39 nmol/day/rat) and group 2 (negative control) received micelle without lutein for 8 weeks. A separate group (no STZ injected) served as a positive control (n = 11/group). Oral glucose tolerance test (OGTT), biweekly urine glucose and activities of aldose reductase (AR) and sorbitol dehydrogenase (SDH) enzymes were assessed. Activities of antioxidant enzymes and antioxidant level were also evaluated. Lutein-administered hyperglycemic rats showed better glucose tolerance as evidenced with OGTT and biweekly urine glucose when compared to negative control. Activities of AR and SDH were decreased in heart and kidney of lutein-fed hyperglycemic rats. Also, they had significantly (p < 0.05) decreased malondialdehyde levels (66, 34, and 33 %) and increased reduced glutathione level (81, 18 and 92 %) in serum, heart and kidney, respectively. Altered antioxidant enzyme activities such as superoxide dismutase, catalase, glutathione peroxidase, glutathione reductase and glutathione transferase were also affected in serum, heart and kidney of lutein-fed diabetic group. Lutein prevented cardiac and renal injury in STZ-induced hyperglycemic rats due to potential amelioration of altered activities in polyol pathway and oxidative stress markers.

  4. Ultrasonography of the Kidney

    DEFF Research Database (Denmark)

    Lindskov Hansen, Kristoffer; Nielsen, Michael Bachmann; Ewertsen, Caroline

    2016-01-01

    Ultrasonography of the kidneys is essential in the diagnosis and management of kidney-related diseases. The kidneys are easily examined, and most pathological changes in the kidneys are distinguishable with ultrasound. In this pictorial review, the most common findings in renal ultrasound...

  5. [Acute kidney injury

    NARCIS (Netherlands)

    Hageman, D.; Kooman, J.P.; Lance, M.D.; Heurn, L.W. van; Snoeijs, M.G.

    2012-01-01

    - 'Acute kidney injury' is modern terminology for a sudden decline in kidney function, and is defined by the RIFLE classification (RIFLE is an acronym for Risk, Injury, Failure, Loss and End-stage kidney disease).- Acute kidney injury occurs as a result of the combination of reduced perfusion in the

  6. Simple Kidney Cysts

    Science.gov (United States)

    ... kidney cysts are abnormal, fluid-filled sacs that form in the kidneys. What are the kidneys and what do they do? The kidneys are two bean-shaped organs, each about the size of a fist. They are located near the ...

  7. Robotic assisted kidney transplantation

    Directory of Open Access Journals (Sweden)

    Pranjal Modi

    2014-01-01

    Full Text Available Kidney transplantation is the standard of care for patients with end stage renal disease. While open surgery remains the gold standard, minimally invasive surgery has recently been introduced for the recipient undergoing kidney transplantation. We review the evolution of techniques of minimally invasive surgery for kidney transplantation with specific emphasis on technical aspects of robotic assisted kidney transplantation.

  8. The Super-Remnant of the Recurrent Nova M31N 2008-12a - A Signpost to Type Ia Supernovae?

    Science.gov (United States)

    Darnley, Matt

    2017-08-01

    M31N 2008-12a is the single most important nova system in M31. With an unprecedented 9 observed eruptions in just 9 years, an ultra-high mass white dwarf, a high accretion rate, and low ejected mass, it is the leading pre-explosion Supernova Type Ia progenitor candidate in any galaxy. Our team uncovered a vast elliptical nebula, centred on the nova - a recurrent nova 'super-remnant', the relic of many thousands of past eruptions. State-of-the-art 'multi-cycle' nova eruption models have shown that a CO WD in a short-recurrence period nova does indeed grow towards the Chandrasekhar mass. Such models predict frequent He-flashes, ejecting significantly more mass at higher velocities, every few-hundred eruptions. Our Cycle 24 Halpha observations confirmed the association between the recurrent nova and its super-remnant, enabled the mapping of the gas density, and provided the first possible evidence of the proposed recurrent He-flashes - large scale 'ripples' in the super-remnant. We propose to utilize the unique high-spatial resolution capabilities of HST at visible wavelengths to obtain a series of deep [S II] images to: (i) uniquely trace the remnant shock structure; (ii) confirm the detection of the signature ripples laid down in the super-remnant by the recurrent He-flashes, hence (iii) constrain models of the super-remnant, allowing extrapolation to other systems, and (iv) validate long-term nova eruption models, and also (v) explore shaping mechanisms both by the nova process and surrounding ISM. The relics of He-flashes within the super-remnant would confirm the new single-degenerate WD growth model, providing crucial evidence in support of the nova pathway to SNe Ia.

  9. Isolation and characterization of a primary proximal tubular epithelial cell model from human kidney by CD10/CD13 double labeling.

    Science.gov (United States)

    Van der Hauwaert, Cynthia; Savary, Grégoire; Gnemmi, Viviane; Glowacki, François; Pottier, Nicolas; Bouillez, Audrey; Maboudou, Patrice; Zini, Laurent; Leroy, Xavier; Cauffiez, Christelle; Perrais, Michaël; Aubert, Sébastien

    2013-01-01

    Renal proximal tubular epithelial cells play a central role in renal physiology and are among the cell types most sensitive to ischemia and xenobiotic nephrotoxicity. In order to investigate the molecular and cellular mechanisms underlying the pathophysiology of kidney injuries, a stable and well-characterized primary culture model of proximal tubular cells is required. An existing model of proximal tubular cells is hampered by the cellular heterogeneity of kidney; a method based on cell sorting for specific markers must therefore be developed. In this study, we present a primary culture model based on the mechanical and enzymatic dissociation of healthy tissue obtained from nephrectomy specimens. Renal epithelial cells were sorted using co-labeling for CD10 and CD13, two renal proximal tubular epithelial markers, by flow cytometry. Their purity, phenotypic stability and functional properties were evaluated over several passages. Our results demonstrate that CD10/CD13 double-positive cells constitute a pure, functional and stable proximal tubular epithelial cell population that displays proximal tubule markers and epithelial characteristics over the long term, whereas cells positive for either CD10 or CD13 alone appear to be heterogeneous. In conclusion, this study describes a method for establishing a robust renal proximal tubular epithelial cell model suitable for further experimentation.

  10. Isolation and characterization of a primary proximal tubular epithelial cell model from human kidney by CD10/CD13 double labeling.

    Directory of Open Access Journals (Sweden)

    Cynthia Van der Hauwaert

    Full Text Available Renal proximal tubular epithelial cells play a central role in renal physiology and are among the cell types most sensitive to ischemia and xenobiotic nephrotoxicity. In order to investigate the molecular and cellular mechanisms underlying the pathophysiology of kidney injuries, a stable and well-characterized primary culture model of proximal tubular cells is required. An existing model of proximal tubular cells is hampered by the cellular heterogeneity of kidney; a method based on cell sorting for specific markers must therefore be developed. In this study, we present a primary culture model based on the mechanical and enzymatic dissociation of healthy tissue obtained from nephrectomy specimens. Renal epithelial cells were sorted using co-labeling for CD10 and CD13, two renal proximal tubular epithelial markers, by flow cytometry. Their purity, phenotypic stability and functional properties were evaluated over several passages. Our results demonstrate that CD10/CD13 double-positive cells constitute a pure, functional and stable proximal tubular epithelial cell population that displays proximal tubule markers and epithelial characteristics over the long term, whereas cells positive for either CD10 or CD13 alone appear to be heterogeneous. In conclusion, this study describes a method for establishing a robust renal proximal tubular epithelial cell model suitable for further experimentation.

  11. Star Clusters in Intermediate-Age Galaxy Merger Remnants

    Science.gov (United States)

    Miller, Bryan W.; Trancho, G.; Schweizer, F.

    2011-01-01

    Studies of globular cluster systems play a critical role in our understanding of galaxy formation. Star clusters are useful tracers of major star-formation events in galaxies since they are compact, relatively easy to detect, and have properties well described by simple-stellar-population models. Imaging with the Hubble Space Telescope has revealed that young compact star clusters are formed copiously during galaxy mergers, strengthening theories in which giant elliptical galaxies are formed through mergers of spirals. However, the formation and evolution of globular cluster systems is still not well understood. We should be able to observe how cluster systems evolve from the very young systems with power-law luminosity functions to old systems with log-normal luminosity functions like those observed in old elliptical galaxies. Finding intermediate-age cluster systems would constrain theories of cluster formation and destruction (evaporation, shocking, dynamical friction) as well as show the significance of merger events in the histories of galaxies. We present results of combining HST optical photometry with ground-based K-band photometry from NIRI and Flamingos-I on Gemini to study the star cluster systems of five intermediate-age merger remnants. The galaxies were chosen based on blue colors and fine structure such as shells and ripples that are indicative of past interactions. We find evidence for star clusters with ages consistent with the estimated merger ages. The properties of the star clusters systems and implications for galaxy and star cluster formation will be discussed. Based on observations obtained at the Gemini Observatory, which is operated by the Association of Universities for Research in Astronomy, Inc., under a cooperative agreement with the NSF on behalf of the Gemini partnership: the National Science Foundation (United States), the Particle Physics and Astronomy Research Council (United Kingdom), the National Research Council (Canada

  12. Mannan-binding lectin in diabetic kidney disease: the impact of mouse genetics in a type 1 diabetes model

    DEFF Research Database (Denmark)

    Østergaard, Jakob; Bjerre, Mette; RamachandraRao, Satish Posettihalli

    2012-01-01

    BACKGROUND: Mannan-binding lectin (MBL) is involved in the development of diabetic nephropathy. MBL is a part of the innate immune system where it can activate the complement system. Serum MBL level predicts later renal impairment in diabetes patients. Direct involvement of MBL in the development...... of diabetic kidney disease is observed in one animal strain. However, this involvement may differ among the animal strains. We thus examined the impact of the genetic background on the role of MBL in diabetic nephropathy. MATERIALS/METHODS: C57BL/6JBomTac and 129S6/SvEvTac mice were compared. In both strains......, experimental type 1 diabetes was induced in wild-type (WT) and MBL-knockout (MBL-KO) mice by streptozotocin. Nondiabetic WT and MBL-KO mice were used as controls. We tested if MBL modified the diabetes-induced kidney changes by two-way ANOVA allowing for interaction. RESULTS: MBL aggravated diabetes...

  13. Typing supernova remnants using X-ray line emission morphologies

    NARCIS (Netherlands)

    Lopez, L.A.; Ramirez-Ruiz, E.; Badenes, C.; Huppenkothen, D.; Jeltema, T.E.; Pooley, D.A.

    2009-01-01

    We present a new observational method to type the explosions of young supernova remnants (SNRs). By measuring the morphology of the Chandra X-ray line emission in 17 Galactic and Large Magellanic Cloud SNRs with a multipole expansion analysis (using power ratios), we find that the core-collapse SNRs

  14. Planck intermediate results XXXI. Microwave survey of Galactic supernova remnants

    DEFF Research Database (Denmark)

    Arnaud, M.; Ashdown, M.; Atrio-Barandela, F.

    2016-01-01

    The all-sky Planck survey in 9 frequency bands was used to search for emission from all 274 known Galactic supernova remnants. Of these, 16 were detected in at least two Planck frequencies. The radio-through-microwave spectral energy distributions were compiled to determine the mechanism for micr...

  15. Supernova remnants, pulsar wind nebulae and their interaction

    NARCIS (Netherlands)

    Swaluw, E. van der

    2001-01-01

    A supernova explosion marks the end of the evolution of a massive star. What remains of the exploded star is a high density neutron star or a black hole. The material which has been ejected by the supernova explosion will manifest itself as a supernova remnant: a hot bubble of gas expanding in the

  16. A Recurrent Nova Super-Remnant in the Andromeda Galaxy

    DEFF Research Database (Denmark)

    Darnley, M. J.; Hounsell, R.; O'Brien, T. J.

    2017-01-01

    Here we report that the most rapidly recurring nova, M31N 2008-12a, which erupts annually, is surrounded by a "nova super-remnant" which demonstrates that M31N 2008-12a has erupted with high frequency for millions of years....

  17. Infection of internal umbilical remnant in foals by Clostridium sordellii.

    Science.gov (United States)

    Ortega, J; Daft, B; Assis, R A; Kinde, H; Anthenill, L; Odani, J; Uzal, F A

    2007-05-01

    Omphalitis and the resulting septicemia contribute to perinatal mortality in several animal species. In foals, the most important causes of omphalitis are Escherichia coli and Streptococcus zooepidemicus. However to date, no information has been published about the role of Clostridium sordellii in these infections. In this paper, we describe 8 cases of perinatal mortality in foals associated with internal umbilical remnant infection by C. sordellii. The foals studied were between 12 and 21 days old at the time of death, and various breeds were represented in the group. Five of the foals were male and 3 were female. The diagnosis was established on the basis of the detection of C. sordellii by 3 methods (culture, fluorescent antibody test, and immunohistochemistry) and on gross and histopathologic findings. All foals had acute peritonitis, and the internal umbilical remnant was thickened by edema, hemorrhage, and fibrosis. A moderate amount of serosanguinous fluid with fibrin strands was present in the pericardial sac and pleural cavity. Histopathologically, the urachus and umbilical arterial walls were thickened by edema and exhibited hemorrhage, fibrin, and leukocytic infiltration. Gram-positive bacterial rods were observed in subepithelial areas of the urachus, the adventicia of umbilical arteries, and interstitium of the internal umbilical remnant. On the basis of these findings, we suggest that C. sordellii should be considered in the differential diagnosis for infections of the internal umbilical remnant in foals.

  18. An Investigation into PAH Destruction in Nearby Supernova Remnants, North Polar Spur and Cygnus Loop

    Science.gov (United States)

    Burkhart, Sarah M.; Witt, Adolf N.

    2015-01-01

    Our goal in conducting this research was to look at the polycyclic aromatic hydrocarbon (PAH)/large dust grain emission intensity ratio in nearby supernova remnants to find evidence for selective PAH destruction by hot gas and high velocity shock waves within these regions, as predicted by the models of Arendt et al. (2010) and Micelotta et al. (2010a,b). Two supernova remnants were studied- the North Polar Spur (NPS) and the Cygnus Loop. The data for PAHs were obtained from the WISE W3 12 micron all-sky map processed by Meisner & Finkbeiner (2014), and the data for the larger grains come from the IRAS 100 micron all-sky map processed by Schlegel, Finkbeiner & Davis (1998). After obtaining a control PAH/large grain intensity ratio of ~2.8 (DN/px)/(MJy/sr) from two high latitude clouds, MBM 30 and MBM 32, we found that the intensity ratios across the NPS and Cygnus Loop were not far off- ~2.7 (DN/px)/(MJy/sr) and ~3.1 (DN/px)/(MJy/sr), respectively- showing no evidence of selective large-scale PAH destruction in supernova remnants. The individual intensities for both PAHs and large grains do decrease inside the Cygnus Loop, however, suggesting a decrease in abundances of both grain types, which could mean total dust grain destruction with the normal ratios coming from foreground and background dust located in the line of sight of the remnant. In addition, temperature and E(B-V) measurements taken from calibrated IRAS images show that while the dust column density increases in the Eastern Veil of the Cygnus Loop, the dust temperature reaches a local maximum, indicating the heating of large grains by interaction with the hot gas in the remnant. The PAH/large grain ratio in the Eastern Veil does decrease and could be indicative of currently ongoing active grain destruction there, with the PAHs being destroyed on a more rapid timescale than the large grains.We are grateful for financial support from the NSF REU Program grant to the Department of Physics & Astronomy at

  19. Urine biomarkers of tubular injury do not improve on the clinical model predicting chronic kidney disease progression.

    Science.gov (United States)

    Hsu, Chi-Yuan; Xie, Dawei; Waikar, Sushrut S; Bonventre, Joseph V; Zhang, Xiaoming; Sabbisetti, Venkata; Mifflin, Theodore E; Coresh, Josef; Diamantidis, Clarissa J; He, Jiang; Lora, Claudia M; Miller, Edgar R; Nelson, Robert G; Ojo, Akinlolu O; Rahman, Mahboob; Schelling, Jeffrey R; Wilson, Francis P; Kimmel, Paul L; Feldman, Harold I; Vasan, Ramachandran S; Liu, Kathleen D

    2017-01-01

    Few investigations have evaluated the incremental usefulness of tubular injury biomarkers for improved prediction of chronic kidney disease (CKD) progression. As such, we measured urinary kidney injury molecule-1, neutrophil gelatinase-associated lipocalin, N-acetyl-ß-D-glucosaminidase and liver fatty acid binding protein under highly standardized conditions among 2466 enrollees of the prospective Chronic Renal Insufficiency Cohort Study. During 9433 person-years of follow-up, there were 581 cases of CKD progression defined as incident end-stage renal disease or halving of the estimated glomerular filtration rate. Levels of the urine injury biomarkers, normalized for urine creatinine, were strongly associated with CKD progression in unadjusted Cox proportional hazard models with hazard ratios in the range of 7 to 15 comparing the highest with the lowest quintiles. However, after controlling for the serum creatinine-based estimated glomerular filtration rate and urinary albumin/creatinine ratio, none of the normalized biomarkers was independently associated with CKD progression. None of the biomarkers improved on the high (0.89) C-statistic for the base clinical model. Thus, among patients with CKD, risk prediction with a clinical model that includes the serum creatinine-based estimated glomerular filtration rate and the urinary albumin/creatinine ratio is not improved on with the addition of renal tubular injury biomarkers. Copyright © 2016 International Society of Nephrology. All rights reserved.

  20. The Aging Kidney: Increased Susceptibility to Nephrotoxicity

    Directory of Open Access Journals (Sweden)

    Xinhui Wang

    2014-09-01

    Full Text Available Three decades have passed since a series of studies indicated that the aging kidney was characterized by increased susceptibility to nephrotoxic injury. Data from these experimental models is strengthened by clinical data demonstrating that the aging population has an increased incidence and severity of acute kidney injury (AKI. Since then a number of studies have focused on age-dependent alterations in pathways that predispose the kidney to acute insult. This review will focus on the mechanisms that are altered by aging in the kidney that may increase susceptibility to injury, including hemodynamics, oxidative stress, apoptosis, autophagy, inflammation and decreased repair.

  1. Beneficial effect of combined treatment with octreotide and pasireotide in PCK rats, an orthologous model of human autosomal recessive polycystic kidney disease.

    Directory of Open Access Journals (Sweden)

    Masanori Kugita

    Full Text Available Increased intracellular cyclic AMP (cAMP in renal tubular epithelia accelerates the progression of polycystic kidney disease (PKD. Thus, decreasing cAMP levels by an adenylyl cyclase inhibitory G protein activator is considered to be an effective approach in ameliorating PKD. In fact, pasireotide (PAS was effective in reducing disease progression in animal models of PKD. However, hyperglycemia caused by the administration of PAS is an adverse effect in its clinical use. Whereas, co-administration of octreotide (OCT with PAS did not increase serum glucose in normal rats. In the current study, we examined the efficacy of combined treatment with OCT and PAS in PCK rats, an autosomal recessive PKD model. Four-week-old PCK males were treated with the long-acting release type of OCT, PAS, or a combination of both (OCT/PAS for 12 weeks. After termination, serum and renal tissue were used for analyses. Kidney weight, kidney weight per body weight, renal cyst area, renal Ki67 expression, and serum urea nitrogen were significantly decreased either in the PAS or OCT/PAS group, compared with vehicle. Renal tissue cAMP content was significantly decreased by PAS or OCT/PAS treatment, but not OCT, compared with vehicle. As a marker of cellular mTOR signaling activity, renal phospho-S6 kinase expression was significantly decreased by OCT/PAS treatment compared with vehicle, OCT, or PAS. Serum glucose was significantly increased by PAS administration, whereas no difference was shown between vehicle and OCT/PAS, possibly because serum glucagon was decreased either by the treatment of OCT alone or co-application of OCT/PAS. In conclusion, since serum glucose levels are increased by the use of PAS, its combination with OCT may reduce the risk of hyperglycemia associated with PAS monotherapy against PKD progression.

  2. IUE spectra and optical imaging of the oxygen-rich supernova remnant N132D

    Science.gov (United States)

    Blair, William P.; Raymond, John C.; Long, Knox S.

    1994-01-01

    We present new optical Charge Coupled Devices (CCD) interference filter imagery and International Ultraviolet Explorer (IUE) spectroscopy for the oxygen-rich supernova remnant N132D in the Large Magellanic Cloud. The optical images show a wealth of structure, and comparison with an archival Einstein High Resolution Imager (HRI) X-ray image shows that a few optical features have X-ray counter-parts, but in general there is little correlation between X-ray and optical features. The IUE spectra at two positions show strong lines of carbon and oxygen, with lines of neon, magnesium, silicon, and helium also present and variable in relative intensities. We use optical data for N132D from Dopita & Tuohy (1984) with our UV observations to compare with shock models (both with and without thermal conduction) and X-ray photoionization model calculations. While none of the model fits is entirely satisfactory, the generally weak UV emission relative to optical disagrees with the general character of shock model predictions and indicates that photoionization is the dominant excitation mechanism for the UV/optical emission. This conclusion is similar to what was found for E0102 - 7219, the oxygen-rich remnant in the Small Magellanic Cloud. We derive rough abundances for the emitting material in N132D, compare to stellar nucleosynthesis models, and discuss the implications for its precursor. A precursor near 20 solar mass is consistent with the data.

  3. Empagliflozin decreases remnant-like particle cholesterol in type 2 diabetes patients with insulin resistance.

    Science.gov (United States)

    Hattori, Sachiko

    2017-11-28

    Remnant lipoproteins are thought to be atherogenic. Remnant-like particle cholesterol (RLP-C), which reflects the levels of various kinds of remnant lipoproteins in the blood, has a significant correlation with insulin resistance. In the present study, we measured the effect of empagliflozin (EMPA) on the levels of RLP-C, and investigated whether EMPA-mediated change in RLP-C is associated with a change in insulin resistance in type 2 diabetes patients who have insulin resistance. Patients were allocated to receive a placebo (n = 51) or EMPA (n = 58) as an add-on treatment. Fasting blood samples were collected before and 12 weeks after this intervention. EMPA significantly decreased glycated hemoglobin, bodyweight, systolic blood pressure, plasma triglycerides, liver transaminases and estimated glomerular filtration rate, and increased high-density lipoprotein cholesterol. Furthermore, EMPA decreased RLP-C and homeostatic model assessment of insulin resistance. In the placebo group, there were no significant changes in these factors except for slight increases in liver transaminases. Multiple regression analysis showed that the change in homeostatic model assessment of insulin resistance (P = 0.0102) and the change in alanine aminotransferase (P = 0.0301) were significantly associated with the change in RLP-C in the EMPA group. The change in RLP-C significantly correlated with the change in homeostatic model assessment of insulin resistance (Pearson correlation coefficient 0.503, 95% confidence interval 0.199-0.719; P = 0.00241). EMPA decreases RLP-C levels, which is closely associated with amelioration of insulin sensitivity in diabetes patients who have insulin resistance. © 2017 The Authors. Journal of Diabetes Investigation published by Asian Association for the Study of Diabetes (AASD) and John Wiley & Sons Australia, Ltd.

  4. Crushing of Interstellar Gas Clouds in Supernova Remnants: the Role of Thermal Conduction and Radiative Losses

    Science.gov (United States)

    Peres, G.; Orlando, S.; Reale, F.; Rosner, R.; Plewa, T.; Siegel, A.

    2004-04-01

    We model hydrodynamic interactions of an old supernova remnant shock wave with a small interstellar gas cloud, taking into account the effects of thermal conduction and radiative losses. In particular, we consider a representative case of a Mach 30 shock impacting on an isolated cloud with density contrast χ = 10 with respect to the ambient medium. Thermal conduction appears to be effective in suppressing the Kelvin-Helmholtz and Rayleigh-Taylor instabilities which would develop at the cloud boundaries. We demonstrate that the radiative losses play a crucial role in the dynamics of the shock-cloud interaction, dominating evolution of the shocked cloud medium.

  5. APOL1-G0 or APOL1-G2 Transgenic Models Develop Preeclampsia but Not Kidney Disease.

    Science.gov (United States)

    Bruggeman, Leslie A; Wu, Zhenzhen; Luo, Liping; Madhavan, Sethu M; Konieczkowski, Martha; Drawz, Paul E; Thomas, David B; Barisoni, Laura; Sedor, John R; O'Toole, John F

    2016-12-01

    APOL1 risk variants are associated with kidney disease in blacks, but the mechanisms of renal injury associated with APOL1 risk variants are unknown. Because APOL1 is unique to humans and some primates, we created transgenic (Tg) mice using the promoter of nephrin-encoding Nphs1 to express the APOL1 reference sequence (G0) or the G2 risk variant in podocytes, establishing Tg lines with a spectrum of APOL1 expression levels. Podocytes from Tg-G0 and Tg-G2 mice did not undergo necrosis, apoptosis, or autophagic cell death in vivo, even in lines with highly expressed transgenes. Further, Tg-G0 and Tg-G2 mice did not develop kidney pathology, proteinuria, or azotemia as of 300 days of age. However, by 200 days of age, Tg-G2 mice had significantly lower podocyte density than age-matched WT and Tg-G0 mice had, a difference that was not evident at weaning. Notably, a pregnancy-associated phenotype that encompassed eclampsia, preeclampsia, fetal/neonatal deaths, and small litter sizes occurred in some Tg-G0 mice and more severely in Tg-G2 mice. Similar to human placenta, placentas of Tg mice expressed APOL1. Overall, these results suggest podocyte depletion could predispose individuals with APOL1 risk genotypes to kidney disease in response to a second stressor, and add to other published evidence associating APOL1 expression with preeclampsia. Copyright © 2016 by the American Society of Nephrology.

  6. An Empirical Biomarker-Based Calculator for Cystic Index in a Model of Autosomal Recessive Polycystic Kidney Disease—The Nieto-Narayan Formula

    Science.gov (United States)

    Nieto, Jake A.; Yamin, Michael A.; Goldberg, Itzhak D.

    2016-01-01

    Autosomal recessive polycystic kidney disease (ARPKD) is associated with progressive enlargement of the kidneys fuelled by the formation and expansion of fluid-filled cysts. The disease is congenital and children that do not succumb to it during the neonatal period will, by age 10 years, more often than not, require nephrectomy+renal replacement therapy for management of both pain and renal insufficiency. Since increasing cystic index (CI; percent of kidney occupied by cysts) drives both renal expansion and organ dysfunction, management of these patients, including decisions such as elective nephrectomy and prioritization on the transplant waitlist, could clearly benefit from serial determination of CI. So also, clinical trials in ARPKD evaluating the efficacy of novel drug candidates could benefit from serial determination of CI. Although ultrasound is currently the imaging modality of choice for diagnosis of ARPKD, its utilization for assessing disease progression is highly limited. Magnetic resonance imaging or computed tomography, although more reliable for determination of CI, are expensive, time-consuming and somewhat impractical in the pediatric population. Using a well-established mammalian model of ARPKD, we undertook a big data-like analysis of minimally- or non-invasive blood and urine biomarkers of renal injury/dysfunction to derive a family of equations for estimating CI. We then applied a signal averaging protocol to distill these equations to a single empirical formula for calculation of CI. Such a formula will eventually find use in identifying and monitoring patients at high risk for progressing to end-stage renal disease and aid in the conduct of clinical trials. PMID:27695033

  7. An Empirical Biomarker-Based Calculator for Cystic Index in a Model of Autosomal Recessive Polycystic Kidney Disease-The Nieto-Narayan Formula.

    Directory of Open Access Journals (Sweden)

    Jake A Nieto

    Full Text Available Autosomal recessive polycystic kidney disease (ARPKD is associated with progressive enlargement of the kidneys fuelled by the formation and expansion of fluid-filled cysts. The disease is congenital and children that do not succumb to it during the neonatal period will, by age 10 years, more often than not, require nephrectomy+renal replacement therapy for management of both pain and renal insufficiency. Since increasing cystic index (CI; percent of kidney occupied by cysts drives both renal expansion and organ dysfunction, management of these patients, including decisions such as elective nephrectomy and prioritization on the transplant waitlist, could clearly benefit from serial determination of CI. So also, clinical trials in ARPKD evaluating the efficacy of novel drug candidates could benefit from serial determination of CI. Although ultrasound is currently the imaging modality of choice for diagnosis of ARPKD, its utilization for assessing disease progression is highly limited. Magnetic resonance imaging or computed tomography, although more reliable for determination of CI, are expensive, time-consuming and somewhat impractical in the pediatric population. Using a well-established mammalian model of ARPKD, we undertook a big data-like analysis of minimally- or non-invasive blood and urine biomarkers of renal injury/dysfunction to derive a family of equations for estimating CI. We then applied a signal averaging protocol to distill these equations to a single empirical formula for calculation of CI. Such a formula will eventually find use in identifying and monitoring patients at high risk for progressing to end-stage renal disease and aid in the conduct of clinical trials.

  8. Imaging end-stage kidney disease in adults: low-field MR imaging with magnetization transfer vs. ultrasonography

    Energy Technology Data Exchange (ETDEWEB)

    Kajander, S.; Kallio, T.; Alanen, A.; Komu, M. [Univ. Hospital of Turku (Finland). Dept. of Diagnostic Radiology; Forsstroem, J. [Univ. Hospital of Turku (Finland). Dept. of Medicine

    2000-07-01

    Purpose: To (1) assess the potential of magnetization transfer (MT)-weighted MR imaging to improve the often poor visibility of native kidneys in patients with a renal transplant; and (2) compare low-field MR imaging and ultrasonography (US) for imaging these fibrotic kidney remnants. Material and Methods: Seventy-two native kidneys of 36 patients were prospectively evaluated with US and MR. In low-field (0.1 T) MR imaging, T1-, T2- and MT-weighted sequences were used. MT-weighted images were compared with T2-weighted images in their ability to delineate the kidneys from their surroundings whereas US and MR were compared for detection of renal cysts and possible solid tumors. Results: MT-weighted images proved superior to conventional T2-weighted images in producing contrast between the kidney remnants and their fatty surroundings. Although US revealed a few small renal cysts that were not seen at MR images, no statistical difference was found between the two modalities in this respect. Conclusion: MT imaging, due to its unique protein-specific signal depression, offers significantly improved visualization and delineation of end-stage kidneys. US, because its better availability and cost-benefit ratio, remains the method-of-choice compared to low-field MR imaging in detecting cysts in multicystic kidneys. MR investigation is helpful in selected patients and may be used as an alternative. Keywords: Kidneys, MR imaging; technology; ultrasonography.

  9. At Risk for Kidney Disease?

    Science.gov (United States)

    ... Heart Disease Mineral & Bone Disorder Causes of Chronic Kidney Disease Diabetes and high blood pressure are the most ... blood vessels in your kidneys. Other causes of kidney disease Other causes of kidney disease include a genetic ...

  10. In Vitro Selection of Cell-Internalizing DNA Aptamers in a Model System of Inflammatory Kidney Disease

    Directory of Open Access Journals (Sweden)

    Glory Ranches

    2017-09-01

    Full Text Available Chronic kidney disease (CKD is a progressive pathological condition marked by a gradual loss of kidney function. Treatment of CKD is most effective when diagnosed at an early stage and patients are still asymptomatic. However, current diagnostic biomarkers (e.g., serum creatinine and urine albumin are insufficient for prediction of the pathogenesis of the disease. To address this need, we applied a cell-SELEX (systematic evolution of ligands by exponential enrichment approach and identified a series of DNA aptamers, which exhibit high affinity and selectivity for cytokine-stimulated cells, resembling some aspects of a CKD phenotype. The cell-SELEX approach was driven toward the enrichment of aptamers that internalize via the endosomal pathway by isolating the endosomal fractions in each selection cycle. Indeed, we demonstrated co-localization of selected aptamers with lysosomal-associated membrane protein 1 (LAMP-1, a late endosomal and lysosomal marker protein, by fluorescence in situ hybridization. These findings are consistent with binding and subsequent internalization of the aptamers into cytokine-stimulated cells. Thus, our study sets the stage for applying selected DNA aptamers as theragnostic reagents for the development of targeted therapies to combat CKD.

  11. 1H NMR-based metabolite profiling of plasma in a rat model of chronic kidney disease.

    Directory of Open Access Journals (Sweden)

    Ju-Ae Kim

    Full Text Available Chronic kidney disease (CKD is characterized by the gradual loss of the kidney function to excrete wastes and fluids from the blood. (1H NMR-based metabolomics was exploited to investigate the altered metabolic pattern in rats with CKD induced by surgical reduction of the renal mass (i.e., 5/6 nephrectomy (5/6 Nx, particularly for identifying specific metabolic biomarkers associated with early of CKD. Plasma metabolite profiling was performed in CKD rats (at 4- or 8-weeks after 5/6 Nx compared to sham-operated rats. Principle components analysis (PCA, partial least squares-discriminant analysis (PLS-DA and orthogonal partial least squares-discriminant analysis (OPLS-DA score plots showed a significant separation between the groups. The resulting metabolic profiles demonstrated significantly increased plasma levels of organic anions, including citrate, β-hydroxybutyrate, lactate, acetate, acetoacetate, and formate in CKD. Moreover, levels of alanine, glutamine, and glutamate were significantly higher. These changes were likely to be associated with complicated metabolic acidosis in CKD for counteracting systemic metabolic acidosis or increased protein catabolism from muscle. In contrast, levels of VLDL/LDL (CH2n and N-acetylglycoproteins were decreased. Taken together, the observed changes of plasma metabolite profiles in CKD rats provide insights into the disturbed metabolism in early phase of CKD, in particular for the altered metabolism of acid-base and/or amino acids.

  12. Testing for Kidney Disease

    Science.gov (United States)

    ... Chronic Kidney Disease? Causes of CKD Tests & Diagnosis Albuminuria: Albumin in the Urine Managing CKD Eating Right ... better. Having albumin in the urine is called albuminuria . A healthy kidney doesn’t let albumin pass ...

  13. Pregnancy and Kidney Disease

    Science.gov (United States)

    ... Donate A to Z Health Guide Pregnancy and Kidney Disease Tweet Share Print Email A new baby is ... disease and pregnancy. Can a woman with "mild" kidney disease have a baby? That depends. There is good ...

  14. Diet - chronic kidney disease

    Science.gov (United States)

    ... page: //medlineplus.gov/ency/article/002442.htm Diet - chronic kidney disease To use the sharing features on this page, ... make changes to your diet when you have chronic kidney disease (CKD). These changes may include limiting fluids, eating ...

  15. Kidney function tests

    Science.gov (United States)

    Kidney function tests are common lab tests used to evaluate how well the kidneys are working. Such tests include: ... Oh MS, Briefel G. Evaluation of renal function, water, electrolytes ... and Management by Laboratory Methods . 23rd ed. Philadelphia, ...

  16. Diabetes and Kidney Disease

    Science.gov (United States)

    ... Health Guide Diabetes - A Major Risk Factor for Kidney Disease Print Email Diabetes mellitus, usually called diabetes, ... Asian Americans. What does diabetes do to the kidneys? With diabetes, the small blood vessels in the ...

  17. American Kidney Fund

    Science.gov (United States)

    ... Become a kidney health educator Clinical Scientist in Nephrology program Online continuining education Clinical trials Advocacy Advocate ... Become a kidney health educator Clinical Scientist in Nephrology program Current CSN Fellow Previous CSN award recipients ...

  18. Tests for Kidney Health

    Science.gov (United States)

    ... Become a Kidney Health Coach Clinical Scientist in Nephrology program Online continuining education Clinical trials Research Advocacy ... Become a Kidney Health Coach Clinical Scientist in Nephrology program Current CSN Fellow Previous CSN award recipients ...

  19. National Kidney Foundation Newsroom

    Science.gov (United States)

    ... Kidney Foundation - 04/10/2017 National University of Malaysia Researcher Honored by National Kidney Foundation - 04/10/ ... Organizations”, a special report in The New England Journal of Medicine - 03/01/2017 Industry News New ...

  20. The optical emission from the supernova remnant HB 3

    Science.gov (United States)

    Fesen, R. A.; Gull, T. R.

    1983-01-01

    The supernova remnant HB 3 was first detected as a radio source by Brown and Hazard (1953). On the basis of subsequent radio studies, it was concluded that the object was a supernova remnant (SNR). HB 3 is located at the far western edge of the H II region/molecular cloud complex W3-W4-W5 (IC 1795-1805-1848). However, a physical association of HB 3 with this complex is uncertain. In the present investigation, attention is called to the probability that HB 3 exhibits a more extensive optical emission structure than previously realized, and one which agrees well with both the position and morphology of the radio emission. It is found that narrow-passband optical images strongly suggest an almost complete optical emission shell for HB 3. Spectroscopic observations are, however, required to confirm that this emission is characteristic of a SNR.

  1. Understanding hadronic gamma-ray emission from supernova remnants

    Energy Technology Data Exchange (ETDEWEB)

    Damiano, Caprioli, E-mail: caprioli@arcetri.astro.it [INAF – Osservatorio Astrofisico di Arcetri, Largo E. Fermi, 5, Firenze (Italy)

    2011-05-01

    We aim to test the plausibility of a theoretical framework in which the gamma-ray emission detected from supernova remnants may be of hadronic origin, i.e., due to the decay of neutral pions produced in nuclear collisions involving relativistic nuclei. In particular, we investigate the effects induced by magnetic field amplification on the expected particle spectra, outlining a phenomenological scenario consistent with both the underlying Physics and the larger and larger amount of observational data provided by the present generation of gamma experiments, which seem to indicate rather steep spectra for the accelerated particles. In addition, in order to study to study how pre-supernova winds might affect the expected emission in this class of sources, the time-dependent gamma-ray luminosity of a remnant with a massive progenitor is worked out. Solid points and limitations of the proposed scenario are finally discussed in a critical way.

  2. The population of supernova remnants in the Magellanic Clouds

    CERN Document Server

    Dennefeld, M

    1978-01-01

    The detection of SNRs in the Magellanic Clouds is reviewed with emphasis on its limits. A sample of SNRs is then used to derive the mean interval between SN explosions, tau . After the maximum constraints have been put on all the other parameters, the distribution of diameters of remnants with diameter less than 30 pc in the LMC is shown to agree well with theoretical predictions. In adopting a mean value of E/sub 0//n/sub 0/ (energy at explosion over surrounding density) of 5*10/sup 51/ ergs cm/sup 3/, the best value of tau is 300+or-100 years in good agreement with predictions from statistics of supernovae in external galaxies. The small number of remnants in the SMC prevents a similar approach being used with any statistical significance. (20 refs).

  3. Fast neutrino conversions: Ubiquitous in compact binary merger remnants

    Science.gov (United States)

    Wu, Meng-Ru; Tamborra, Irene

    2017-05-01

    The massive neutron star (NS) or black hole (BH) accretion disk resulting from NS-NS or NS-BH mergers is dense in neutrinos. We present the first study on the role of angular distributions in the neutrino flavor conversion above the remnant disk. In particular, we focus on "fast" pairwise conversions whose rate depends on the local angular intensity of the electron lepton number carried by neutrinos. Because of the emission geometry and the flux density of ν¯ e being larger than that of νe, fast conversions prove to be a generic phenomenon in NS-NS and NS-BH mergers for physically motivated disturbances in the mean field of flavor coherence. Our findings suggest that, differently from the core-collapse supernova case, fast flavor conversions seem to be unavoidable in compact mergers and could have major consequences for the jet dynamics and the synthesis of elements above the remnant disk.

  4. New distances to four supernova remnants from HI absorption profiles

    Science.gov (United States)

    Leahy, Denis; Ranasinghe, Sujith; Tian, Wenwu

    2018-01-01

    A list was compiled of supernova remnants without previously measured distances that were located in the area of the VPGS survey. The VGPS survey covers Galactic longitude 18 to 67 degrees and Galactic latitude from -1.3 to +1.3 degrees. HI spectra were extracted from the VGPS HI data. Four of the supernova remnants had good quality HI spectra. From the velocities of the absorption features we determine the distances and estimate their individual distance uncertainties. The four SNRs are G24.7+0.6, G29.6+0.1, G41.5+0.4 and G57.2+0.8. Their distances are 3.5 kpc, 4.7 kpc, 4.1 kpc and 4.5 to 9 kpc.

  5. Hydronephrosis of one kidney

    Science.gov (United States)

    ... Acute hydronephrosis; Urinary obstruction; Unilateral hydronephrosis; Nephrolithiasis - hydronephrosis; Kidney stone - hydronephrosis; Renal calculi - hydronephrosis; Ureteral calculi - hydronephrosis; ...

  6. The senile kidney

    Directory of Open Access Journals (Sweden)

    Denisova Т.Р.

    2015-03-01

    Full Text Available The given work summarizes external data and self-obtained results on development and diagnostic of kidney involution modifications. Article discusses definition of "senile kidney" as a clinical and pathomorphological term. Major statements on pathophysiological causes of age-associated renal disorders and their prognosis, specifics of chronic kidney disease in elderly and senile patients have been reviewed. Phenomenon of renal "multimorbidity" in eldely maximizes worsening risk of unmodifiable kidney function.

  7. Current status in remnant gastric cancer after distal gastrectomy

    Science.gov (United States)

    Ohira, Masaichi; Toyokawa, Takahiro; Sakurai, Katsunobu; Kubo, Naoshi; Tanaka, Hiroaki; Muguruma, Kazuya; Yashiro, Masakazu; Onoda, Naoyoshi; Hirakawa, Kosei

    2016-01-01

    Remnant gastric cancer (RGC) and gastric stump cancer after distal gastrectomy (DG) are recognized as the same clinical entity. In this review, the current knowledges as well as the non-settled issues of RGC are presented. Duodenogastric reflux and denervation of the gastric mucosa are considered as the two main factors responsible for the development of RGC after benign disease. On the other hand, some precancerous circumstances which already have existed at the time of initial surgery, such as atrophic gastritis and intestinal metaplasia, are the main factors associated with RGC after gastric cancer. Although eradication of Helicobacter pylori (H. pylori) in remnant stomach is promising, it is still uncertain whether it can reduce the risk of carcinogenesis. Periodic endoscopic surveillance after DG was reported useful in detecting RGC at an early stage, which offers a chance to undergo minimally invasive endoscopic treatment or laparoscopic surgery and leads to an improved prognosis in RGC patients. Future challenges may be expected to elucidate the benefit of eradication of H. pylori in the remnant stomach if it could reduce the risk for RGC, to build an optimal endoscopic surveillance strategy after DG by stratifying the risk for development of RGC, and to develop a specific staging system for RGC for the standardization of the treatment by prospecting the prognosis. PMID:26937131

  8. Don’t get caught out! A rare case of a calcified urachal remnant mimicking a bladder calculus

    Science.gov (United States)

    Rodrigues, Jonathan Carl Luis; Gandhi, Sanjay

    2013-01-01

    Computer tomography through the kidneys, ureters and bladder (CT KUB) is the mainstay investigation of suspected renal tract calculi. However, several pathologies other than renal tract calculi can cause apparent urinary bladder calcification. We describe the case of a 45 year old man who presented with left sided renal colic. Prone CT KUB performed on admission revealed a calcified urachal remnant mimicking a urinary bladder calculus in the dependent portion of the urinary bladder, confirmed by reviewing the multi-planar reformatted images. This is the first reported case in the literature of this phenomenon. We discuss the importance of using multi-planar reformatted images (MPR) and maximum intensity projection images (MIP), as well as careful review of previous imaging, in making the correct diagnosis. We also discuss the differential diagnoses that should be considered when presented with urinary bladder calcification. PMID:23705044

  9. An epidemiologic model to project the impact of changes in glomerular filtration rate on quality of life and survival among persons with chronic kidney disease

    Directory of Open Access Journals (Sweden)

    Levy AR

    2014-07-01

    Full Text Available Adrian R Levy,1,2 Robert M Perkins,3 Karissa M Johnston,2 Sean D Sullivan,4 Vipan C Sood,5 Wendy Agnese,5 Mark A Schnitzler61Department of Community Health and Epidemiology, Dalhousie University, Halifax, NS, Canada; 2Oxford Outcomes Ltd, Vancouver, BC, Canada; 3Center for Health Research and Division of Nephrology, Geisinger Health System, Danville, PA, USA; 4School of Pharmacy, University of Washington, Seattle, WA, USA; 5Mitsubishi Tanabe Pharma America, Jersey City, NJ, USA; 6Departments of Internal Medicine and Community Health, Saint Louis University, St Louis, MO, USAPurpose: Predicting the timing and number of end-stage renal disease (ESRD cases from a population of individuals with pre-ESRD chronic kidney disease (CKD has not previously been reported. The objective is to predict the timing and number of cases of ESRD occurring over the lifetime of a cohort of hypothetical CKD patients in the US based on a range of baseline estimated glomerular filtration rate (eGFR values and varying rates of eGFR decline.Methods: A three-state Markov model – functioning kidney, ESRD, and death – with an annual cycle length is used to project changes in baseline eGFR on long-term health outcomes in a hypothetical cohort of CKD patients. Using published eGFR-specific risk equations and adjusting for predictive characteristics, the probability of ESRD (eGFR <10, time to death, and incremental cost-effectiveness ratios for hypothetical treatments (costing US$10, $5, and $2/day, are projected over the cohort's lifetime under two scenarios: an acute drop in eGFR (mimicking acute kidney injury and a reduced hazard ratio for ESRD (mimicking an effective intervention.Results: Among CKD patients aged 50 years, an acute eGFR decrement from 45 mL/minute to 35 mL/minute yields decreases of 1.6 life-years, 1.5 quality-adjusted life-years (QALYs, 0.8 years until ESRD, and an increase of 183 per 1,000 progressing to ESRD. Among CKD patients aged 60 years, lowering

  10. Loss of MeCP2 Causes Urological Dysfunction and Contributes to Death by Kidney Failure in Mouse Models of Rett Syndrome.

    Directory of Open Access Journals (Sweden)

    Christopher S Ward

    Full Text Available Rett Syndrome (RTT is a neurodevelopmental disorder characterized by loss of acquired skills during development, autonomic dysfunction, and an increased risk for premature lethality. Clinical experience identified a subset of individuals with RTT that present with urological dysfunction including individuals with frequent urinary tract infections, kidney stones, and urine retention requiring frequent catheterization for bladder voiding. To determine if urologic dysfunction is a feature of RTT, we queried the Rett Syndrome Natural History Study, a repository of clinical data from over 1000 individuals with RTT and found multiple instances of urological dysfunction. We then evaluated urological function in a mouse model of RTT and found an abnormal pattern of micturition. Both male and female mice possessing Mecp2 mutations show a decrease in urine output per micturition event. Furthermore, we identified signs of kidney failure secondary to urethral obstruction. Although genetic strain background significantly affects both survival and penetrance of the urethral obstruction phenotype, survival and penetrance of urethral obstruction do not directly correlate. We have identified an additional phenotype caused by loss of MeCP2, urological dysfunction. Furthermore, we urge caution in the interpretation of survival data as an endpoint in preclinical studies, especially where causes of mortality are poorly characterized.

  11. Loss of MeCP2 Causes Urological Dysfunction and Contributes to Death by Kidney Failure in Mouse Models of Rett Syndrome.

    Science.gov (United States)

    Ward, Christopher S; Huang, Teng-Wei; Herrera, José A; Samaco, Rodney C; Pitcher, Meagan R; Herron, Alan; Skinner, Steven A; Kaufmann, Walter E; Glaze, Daniel G; Percy, Alan K; Neul, Jeffrey L

    2016-01-01

    Rett Syndrome (RTT) is a neurodevelopmental disorder characterized by loss of acquired skills during development, autonomic dysfunction, and an increased risk for premature lethality. Clinical experience identified a subset of individuals with RTT that present with urological dysfunction including individuals with frequent urinary tract infections, kidney stones, and urine retention requiring frequent catheterization for bladder voiding. To determine if urologic dysfunction is a feature of RTT, we queried the Rett Syndrome Natural History Study, a repository of clinical data from over 1000 individuals with RTT and found multiple instances of urological dysfunction. We then evaluated urological function in a mouse model of RTT and found an abnormal pattern of micturition. Both male and female mice possessing Mecp2 mutations show a decrease in urine output per micturition event. Furthermore, we identified signs of kidney failure secondary to urethral obstruction. Although genetic strain background significantly affects both survival and penetrance of the urethral obstruction phenotype, survival and penetrance of urethral obstruction do not directly correlate. We have identified an additional phenotype caused by loss of MeCP2, urological dysfunction. Furthermore, we urge caution in the interpretation of survival data as an endpoint in preclinical studies, especially where causes of mortality are poorly characterized.

  12. Supernova remnants and diffuse ionized gas in M31

    Science.gov (United States)

    Walterbos, Rene; Braun, Robert

    1990-01-01

    Researchers have compiled an initial list of radio/optical supernova remnants (SNRs) in M31, by searching for radio identifications of emission-line sources with a high (SII)/H alpha ratio (greater than 0.60). The (SII) filter included both sulfur lines and the H alpha filter did not include (NII). This search revealed 11 SNRs, of which only two were known. In addition, researchers detected radio emission from 3 SNRs that were identified in previous optical surveys (D'Odorico et al., 1980), but that were outside the charge coupled device (CCD) fields. The 14 objects only include the most obvious candidates, but a full search is in progress and the researchers expect to find several more SNRs. Also not all optical SNRs show detectable radio emission and a pure optical list of SNR candidates based only on the ratio of (SII)/H alpha emission contains many more objects. Two conclusions are apparent. First, the radio properties of the SNRs in M31 are quite similar to those of Galactic SNRs as is illustrated. The brightnesses are not systematically lower as has been suggested in the past (Dickel and D'Odorico, 1984). Second, the slope of the relation is close to -2; this slope is expected from the intrinsic dependence between surface brightness and diameter. The radio luminosity of the SNRs does not seem to depend strongly on diameter, or age, contrary to model predictions. Selection effects, however, play an important role in these plots. The CCD images show widespread diffuse ionized gas with a ratio of (SII)/H alpha that is higher than that of discrete HII regions. Discrete HII regions typically show ratios between 0.2 to 0.3, while the diffuse gas in the arms consistently shows ratios of 0.5. Researchers can trace this gas across the spiral arms to emission measures below 5 pc cm (-6). Its properties seem to be similar to that of the diffuse gas in the solar neighborhood.

  13. Using the Rasch model to validate and enhance the interpretation of the Functional Assessment of Cancer Therapy-Kidney Symptom Index--Disease-Related Symptoms scale.

    Science.gov (United States)

    Luo, Xuemei; Cappelleri, Joseph C; Cella, David; Li, Jim Z; Charbonneau, Claudie; Kim, Sindy T; Chen, Isan; Motzer, Robert J

    2009-06-01

    The Functional Assessment of Cancer Therapy-Kidney Symptom Index-Disease-Related Symptoms (FKSI-DRS) was developed to assess patients' kidney-cancer-related symptoms. The Rasch rating scale, a one-parameter logistic item response model, may enhance FKSI-DRS interpretation and validate its measurement properties. We applied the Rasch model to FKSI-DRS data from a randomized phase 3 trial in which first-line sunitinib therapy showed superiority to interferon-alfa in patients with metastatic renal cell carcinoma. Of 750 enrolled patients, 668 patients completed the questionnaire on cycle 1, day 28 and were evaluated in the current study. The nine FKSI-DRS items were analyzed to enhance interpretation of the summary score by using an item characteristic curve that related score to probability of reporting specific symptoms. The Rasch model fitted the FKSI-DRS well: 8 of 9 items had acceptable infit and outfit statistics (0.5); item difficulty spanned a wide range (-3.23 to 1.64 logits); and the five response categories performed adequately. The item characteristic curve offered enhanced interpretation of FKSI-DRS: For example, an FKSI-DRS score of 27 (mean baseline score for total sample) indicated a 47% chance of reporting "no" to "lack of energy," although a two-point difference between sunitinib and interferon-alfa, averaged across all assessments (29 vs. 27), corresponded to sunitinib achieving a 28% increase (13% absolute difference) in the probability of reporting "no" to "lack of energy" (60% vs. 47%). Data suggest that the FKSI-DRS is an adequate measure of symptom status in patients with metastatic renal cell carcinoma. The Rasch model supports its validation and enhances its interpretation.

  14. Evolution of High-energy Particle Distribution in Mature Shell-type Supernova Remnants

    Science.gov (United States)

    Zeng, Houdun; Xin, Yuliang; Liu, Siming; Jokipii, J. R.; Zhang, Li; Zhang, Shuinai

    2017-01-01

    Multi-wavelength observations of mature supernova remnants (SNRs), especially with recent advances in γ-ray astronomy, make it possible to constrain energy distribution of energetic particles within these remnants. In consideration of the SNR origin of Galactic cosmic rays and physics related to particle acceleration and radiative processes, we use a simple one-zone model to fit the nonthermal emission spectra of three shell-type SNRs located within 2° on the sky: RX J1713.7-3946, CTB 37B, and CTB 37A. Although radio images of these three sources all show a shell (or half-shell) structure, their radio, X-ray, and γ-ray spectra are quite different, offering an ideal case to explore evolution of energetic particle distribution in SNRs. Our spectral fitting shows that (1) the particle distribution becomes harder with aging of these SNRs, implying a continuous acceleration process, and the particle distributions of CTB 37A and CTB 37B in the GeV range are harder than the hardest distribution that can be produced at a shock via the linear diffusive shock particle acceleration process, so spatial transport may play a role; (2) the energy loss timescale of electrons at the high-energy cutoff due to synchrotron radiation appears to be always a bit (within a factor of a few) shorter than the age of the corresponding remnant, which also requires continuous particle acceleration; (3) double power-law distributions are needed to fit the spectra of CTB 37B and CTB 37A, which may be attributed to shock interaction with molecular clouds.

  15. Does size matter? Kidney transplant donor size determines kidney function among living donors

    Science.gov (United States)

    Narasimhamurthy, Meenakshi; Smith, Lachlan M.; Machan, Jason T.; Reinert, Steven E.; Gohh, Reginald Y.; Dworkin, Lance D.; Merhi, Basma; Patel, Nikunjkumar; Beland, Michael D.

    2017-01-01

    Background Kidney donor outcomes are gaining attention, particularly as donor eligibility criteria continue to expand. Kidney size, a useful predictor of recipient kidney function, also likely correlates with donor outcomes. Although donor evaluation includes donor kidney size measurements, the association between kidney size and outcomes are poorly defined. Methods We examined the relationship between kidney size (body surface area-adjusted total volume, cortical volume and length) and renal outcomes (post-operative recovery and longer-term kidney function) among 85 kidney donors using general linear models and time-to-chronic kidney disease data. Results Donors with the largest adjusted cortical volume were more likely to achieve an estimated glomerular filtration rate (eGFR) ≥60 mL/min/1.73 m2 over a median 24-month follow-up than those with smaller cortical volumes (P kidney donors were more likely to achieve an eGFR ≥60 mL/min/1.73 m2 with renal recovery over a shorter duration due to higher pre-donation and initial post-nephrectomy eGFRs. PMID:28638611

  16. Thermal Analyses of a Human Kidney and a Rabbit Kidney During Cryopreservation by Vitrification.

    Science.gov (United States)

    Ehrlich, Lili E; Fahy, Gregory M; Wowk, Brian G; Malen, Jonathan A; Rabin, Yoed

    2018-01-01

    This study focuses on thermal analysis of the problem of scaling up from the vitrification of rabbit kidneys to the vitrification of human kidneys, where vitrification is the preservation of biological material in the glassy state. The basis for this study is a successful cryopreservation protocol for a rabbit kidney model, based on using a proprietary vitrification solution known as M22. Using the finite element analysis (FEA) commercial code ANSYS, heat transfer simulations suggest that indeed the rabbit kidney unquestionably cools rapidly enough to be vitrified based on known intrarenal concentrations of M22. Scaling up 21-fold, computer simulations suggest less favorable conditions for human kidney vitrification. In this case, cooling rates below -100 °C are sometimes slower than 1 °C/min, a rate that provides a clear-cut margin of safety at all temperatures based on the stability of rabbit kidneys in past studies. Nevertheless, it is concluded in this study that vitrifying human kidneys is possible without significant ice damage, assuming that human kidneys can be perfused with M22 as effectively as rabbit kidneys. The thermal analysis suggests that cooling rates can be further increased by a careful design of the cryogenic protocol and by tailoring the container to the shape of the kidney, in contrast to the present cylindrical container. This study demonstrates the critical need for the thermal analysis of experimental cryopreservation and highlights the unmet need for measuring the thermophysical properties of cryoprotective solutions under conditions relevant to realistic thermal histories.

  17. Panaxadiol Saponin and Dexamethasone Improve Renal Function in Lipopolysaccharide-Induced Mouse Model of Acute Kidney Injury.

    Directory of Open Access Journals (Sweden)

    Yan Chen

    Full Text Available Acute kidney injury (AKI is a serious complication of systemic inflammatory response syndrome (SIRS, which has a high mortality rate. Previous studies showed that panaxadiol saponin (PDS and Dexamethasone have similar anti-inflammatory properties and protect cardiopulmonary function in lipopolysaccharide (LPS-induced septic shock rats. In the present study, we investigated whether PDS or Dexamethasone has a similar role in improving kidney function in LPS-induced AKI mice.Mice subjected to LPS (10 mg/kg treatment exhibited AKI demonstrated by markedly increased blood urea nitrogen and creatinine levels compared with controls (P<0.01. However, PDS and Dexamethasone induce similar reverse effects on renal function, such as reduced serum creatinine and blood urea nitrogen levels compared with the LPS group (P<0.05. PDS decreased the production and release of tumor necrosis factor (TNF-α and interleukin (IL-6 by inhibiting the NF-κB signaling pathway, down-regulating inducible nitric oxide synthase protein expression levels and inhibiting oxidative stress. In most anti-AKI mechanisms, PDS and dexamethasone were similar, but PDS are better at inhibition of TNF production, promote SOD activity and inhibition of IKB phosphorylation. In addition, nuclear glucocorticoid receptor expression was markedly enhanced in PDS and Dexamethasone treatment groups. Further research is required to determine whether PDS can combine with the glucocorticoid receptor to enter the nucleus.This study demonstrated that PDS and dexamethasone have similar reverse amelioration for renal functions, and have potential application prospects in the treatment of sepsis-induced AKI.

  18. Computer simulations of cosmic-ray diffusion near supernova remnant shock waves

    Science.gov (United States)

    Max, C. E.; Zachary, A. L.; Arons, J.

    1989-01-01

    A plasma simulation model was used to study the resonant interactions between streaming cosmic-ray ions and a self-consistent spectrum of Alfven waves, such as might exist in the interstellar medium upstream of a supernova remnant shock wave. The computational model is a hybrid one, in which the background interstellar medium is an MHD fluid and the cosmic-rays are discrete kinetic particles. The particle sources for the electromagnetic fields are obtained by averaging over the fast cyclotron motions. When the perturbed magnetic field is larger than 10 percent of the background field, the macro- and microphysics are no longer correctly predicted by quasi-linear theory. The particles are trapped by the waves and show sharp jumps in their pitch-angles relative to the background magnetic field, and the effective ninety-degree scattering time for diffusion parallel to the background magnetic field is reduced to between 5 and 30 cyclotron periods. Simulation results suggest that Type 1 supernova remnants may be the principal sites of cosmic ray acceleration.

  19. FERMI-LAT AND WMAP OBSERVATIONS OF THE PUPPIS A SUPERNOVA REMNANT

    Energy Technology Data Exchange (ETDEWEB)

    Hewitt, J. W. [NASA Goddard Space Flight Center, Greenbelt, MD 20771 (United States); Grondin, M.-H. [Max-Planck-Institut fuer Kernphysik, D-69029 Heidelberg (Germany); Lemoine-Goumard, M.; Reposeur, T. [Centre d' Etudes Nucleaires de Bordeaux-Gradignan, Universite Bordeaux 1, CNRS/IN2p3, F-33175 Gradignan (France); Ballet, J. [Laboratoire AIM, CEA-IRFU/CNRS/Universite Paris Diderot, Service d' Astrophysique, CEA Saclay, F-91191 Gif sur Yvette (France); Tanaka, T., E-mail: john.w.hewitt@nasa.gov, E-mail: marie-helene.grondin@mpi-hd.mpg.de, E-mail: lemoine@cenbg.in2p3.fr [W. W. Hansen Experimental Physics Laboratory, Kavli Institute for Particle Astrophysics and Cosmology, Department of Physics and SLAC National Accelerator Laboratory, Stanford University, Stanford, CA 94305 (United States)

    2012-11-10

    We report the detection of GeV {gamma}-ray emission from the supernova remnant (SNR) Puppis A with the Fermi Gamma-Ray Space Telescope. Puppis A is among the faintest SNRs yet detected at GeV energies, with a luminosity of only 2.7 Multiplication-Sign 10{sup 34} (D/2.2 kpc){sup 2} erg s{sup -1} between 1 and 100 GeV. The {gamma}-ray emission from the remnant is spatially extended, with a morphology matching that of the radio and X-ray emission, and is well described by a simple power law with an index of 2.1. We attempt to model the broadband spectral energy distribution (SED), from radio to {gamma}-rays, using standard nonthermal emission mechanisms. To constrain the relativistic electron population we use 7 years of Wilkinson Microwave Anisotropy Probe data to extend the radio spectrum up to 93 GHz. Both leptonic- and hadronic-dominated models can reproduce the nonthermal SED, requiring a total content of cosmic-ray electrons and protons accelerated in Puppis A of at least W {sub CR} Almost-Equal-To (1-5) Multiplication-Sign 10{sup 49} erg.

  20. Comparison of the expected and observed supernova remnant counts with Fermi/LAT

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    Vovk Ie.

    2015-01-01

    Full Text Available SNRs are commonly believed to be the accelerators of the galactic cosmic rays – mainly protons – and are expected to produce γ-rays through the inelastic proton-proton collisions. Fermi/LAT was expected to detect many of those, but only a dozen is listed in the recent Fermi/LAT 2nd Source catalogue. To test whether the observed number of SNRs is in agreement with the above assumption, we use a simplified model of an SNR and calculate the predicted amount of the observable remnants taking into account their distribution in the Galaxy and the sensitivity of Fermi/LAT. We find that the observed number of SNRs agrees with the prediction of our model if we assume a low, ≪ 1 cm−3, number density of the SNR's ambient medium. The result, presented here, suggests, that on average the supernova explosions happen in the under-dense regions, such as bubbles, creating by the winds of the progenitor stars. Under this natural supposition our result finds an agreement with the assumption, that the observed population of supernovae remnants is indeed responsible for the production of the galactic cosmic rays.

  1. Re-examination of the Expected Gamma-Ray Emission of Supernova Remnant SN 1987A

    Science.gov (United States)

    Berezhko, E. G.; Ksenofontov, L. T.; Völk, H. J.

    2015-09-01

    A nonlinear kinetic theory, combining cosmic-ray (CR) acceleration in supernova remnants (SNRs) with their gas dynamics, is used to re-examine the nonthermal properties of the remnant of SN 1987A for an extended evolutionary period of 5-50 year. This spherically symmetric model is approximately applied to the different features of the SNR, consisting of (i) a blue supergiant wind and bubble, and (ii) of the swept-up red supergiant (RSG) wind structures in the form of an H ii region, an equatorial ring (ER), and an hourglass region. The RSG wind involves a mass loss rate that decreases significantly with elevation above and below the equatorial plane. The model adapts recent three-dimensional hydrodynamical simulations by Potter et al. in 2014 that use a significantlysmaller ionized mass of the ER than assumed in the earlier studies by the present authors. The SNR shock recently swept up the ER, which is the densest region in the immediate circumstellar environment. Therefore, the expected gamma-ray energy flux density at TeV energies in the current epoch has already reached its maximal value of ˜10-13 erg cm-2 s-1. This flux should decrease by a factor of about two over the next 10 years.

  2. A Localized Ischemic Preconditioning Regimen Increases Tumor Necrosis Factor α Expression in a Rat Model of Kidney Ischemia-Reperfusion Injury.

    Science.gov (United States)

    Khalid, Usman; Jenkins, Robert H; Pino-Chavez, Gilda; Bowen, Timothy; Fraser, Donald J; Chavez, Rafael

    2015-12-01

    We evaluated a continuous, immediate, localized ischemic preconditioning regimen in a rat model of ischemia-reperfusion injury and assessed whether it attenuated injury at the histologic and molecular levels. Fifteen adult male Lewis rats received sham operation, left unilateral warm ischemia (45 minutes of cross-clamping of the renal pedicle; ischemia-reperfusion injury group), or 15 minutes of ischemia followed by a 20-minute reperfusion period, 45 minutes of ischemia-reperfusion injury, and subsequent reperfusion (ischemic preconditioning/ischemia-reperfusion injury group). Kidney tissue was retrieved 48 hours later, sectioned, stained with hematoxylin and eosin, and examined. We used RNA extraction and real-time quantitative polymerase chain reaction analysis to assess acute kidney injury markers, cytokines, and microRNA-21. Forty-five minutes of unilateral ischemia-reperfusion injury caused marked changes in histology at 48 hours, characterized by endothelial loss, tubulointerstitial damage (inflammation, cast formation), tubular cell necrosis, and glomerular capsule thickening. The ischemia-reperfusion injury and ischemic preconditioning/ischemia-reperfusion injury groups showed no measurable differences in histology. Expression of the acute kidney injury markers was significantly increased in the ischemia-reperfusion injury versus Sham group; however, no difference was found between the ischemia reperfusion injury and ischemic preconditioning/ischemia-reperfusion injury groups. Similarly, expression of interleukin 17, interleukin 18, and tumor necrosis factor ? was significantly increased in the ischemia-reperfusion injury versus Sham group. No significant difference was found between the ischemia-reperfusion injury and ischemic preconditioning/ischemia-reperfusion injury groups for interleukin 17 and interleukin 18; however, tumor necrosis factor ? expression was significantly increased in the ischemic preconditioning/ischemia-reperfusion injury versus

  3. Kidney disease and cognitive function.

    Science.gov (United States)

    Elias, Merrill F; Dore, Gregory A; Davey, Adam

    2013-01-01

    We provide a brief review of research on chronic kidney disease and cognitive performance, including dementia. We touch briefly on the literature relating end-stage-renal disease to cognitive function, but focus on studies of modest and moderate forms of chronic kidney disease (CKD) that precede dialysis and transplantation. We summarize previous reviews dealing with case control studies of patients but more fully examine community-based studies with large samples and necessary controls for demographic risk factors, cardiovascular variables, and other confounds such as depression. In addition we suggest potential biological and social-psychological mediators between CKD and cognition. Studies follow in two categories of design: (1) cross-sectional studies, and (2) longitudinal studies. In each, CKD is related to a wide range of deficits in cognitive functioning including verbal and visual memory and organization, and components of executive functioning and fluid intellect. In general, prior to the need to treat with hemodialysis (HD) or kidney transplant (KT), magnitude of effect with relation to CKD and function are small or modest in persons free from acute stroke and dementia. However, HD and KT can result in major impairment. We discuss needed controls, the greater demand on controls after the start of HD and KT, and suggest that mechanisms intervening relations between hypertension, or diabetes, and cognitive performance may be similar to those intervening between hypertension and cognitive performance and the hypertension and diabetes literature on cognition provides a good model for the study of early stage kidney disease and cognitive ability. We posit that the mechanisms linking CKD and cognition may be similar to those linking hypertension or diabetes to cognition. We identify the need for more studies with multiple cognitive test batteries, measures of every-day cognitive abilities relevant to patient understanding of the disease and treatments, and more

  4. Application of a physiologically based pharmacokinetic model informed by a top-down approach for the prediction of pharmacokinetics in chronic kidney disease patients.

    Science.gov (United States)

    Sayama, Hiroyuki; Takubo, Hiroaki; Komura, Hiroshi; Kogayu, Motohiro; Iwaki, Masahiro

    2014-09-01

    Quantitative prediction of the impact of chronic kidney disease (CKD) on drug disposition has become important for the optimal design of clinical studies in patients. In this study, clinical data of 151 compounds under CKD conditions were extensively surveyed, and alterations in pharmacokinetic parameters were evaluated. In CKD patients, the unbound hepatic intrinsic clearance decreased to a similar extent for drugs eliminated via hepatic metabolism by cytochrome P450, UDP-glucuronosyltransferase, and other mechanisms. Renal clearance showed a similar decrease to glomerular filtration rate, irrespective of the contribution of tubular secretion. The scaling factor (SF) obtained from the interquartile range of the relative change in each parameter was applied to the well-stirred model to predict clearance in patients. Hepatic and renal clearance could be successfully predicted for approximately half and two-thirds, respectively, of the applied compounds, showing the high utility of SFs. SFs were also introduced to a physiologically based pharmacokinetic (PBPK) model, and the plasma concentration profiles of 12 model compounds with different elimination pathways were predicted for CKD patients. The PBPK model combined with SFs provided good predictability for plasma concentration. The developed PBPK model with information on SFs would accelerate translational research in drug development by predicting pharmacokinetics in CKD patients.

  5. High-Resolution X-Ray Spectroscopy of the Galactic Supernova Remnant Puppis A with the XMM-Newton RGS

    Science.gov (United States)

    Katsuda, Satoru; Tsunemi, Hiroshi; Mori, Koji; Uchida, Hiroyuki; Petre, Robert; Yamada, Shinya; Akamatsu, Hiroki; Konami, Saori; Tamagawa, Toru

    2012-01-01

    We present high-resolution X-ray spectra of cloud-shock interaction regions in the eastern and northern rims of the Galactic supernova remnant Puppis A, using the Reflection Grating Spectrometer onboard the XMM-Newton satellite. A number of emission lines including K(alpha) triplets of He-like N, O , and Ne are clearly resolved for the first time. Intensity ratios of forbidden to resonance lines in the triplets are found to be higher than predictions by thermal emission models having plausible plasma parameters. The anomalous line ratios cannot be reproduced by effects of resonance scattering, recombination, or inner-shell ionization processes, but could be explained by charge-exchange emission that should arise at interfaces between the cold/warm clouds and the hot plasma. Our observations thus provide observational support for charge-exchange X-ray emission in supernova remnants.

  6. OXYGEN-RICH SUPERNOVA REMNANT IN THE LARGE MAGELLANIC CLOUD

    Science.gov (United States)

    2002-01-01

    This is a NASA Hubble Space Telescope image of the tattered debris of a star that exploded 3,000 years ago as a supernova. This supernova remnant, called N132D, lies 169,000 light-years away in the satellite galaxy, the Large Magellanic Cloud. A Hubble Wide Field Planetary Camera 2 image of the inner regions of the supernova remnant shows the complex collisions that take place as fast moving ejecta slam into cool, dense interstellar clouds. This level of detail in the expanding filaments could only be seen previously in much closer supernova remnants. Now, Hubble's capabilities extend the detailed study of supernovae out to the distance of a neighboring galaxy. Material thrown out from the interior of the exploded star at velocities of more than four million miles per hour (2,000 kilometers per second) plows into neighboring clouds to create luminescent shock fronts. The blue-green filaments in the image correspond to oxygen-rich gas ejected from the core of the star. The oxygen-rich filaments glow as they pass through a network of shock fronts reflected off dense interstellar clouds that surrounded the exploded star. These dense clouds, which appear as reddish filaments, also glow as the shock wave from the supernova crushes and heats the clouds. Supernova remnants provide a rare opportunity to observe directly the interiors of stars far more massive than our Sun. The precursor star to this remnant, which was located slightly below and left of center in the image, is estimated to have been 25 times the mass of our Sun. These stars 'cook' heavier elements through nuclear fusion, including oxygen, nitrogen, carbon, iron etc., and the titanic supernova explosions scatter this material back into space where it is used to create new generations of stars. This is the mechanism by which the gas and dust that formed our solar system became enriched with the elements that sustain life on this planet. Hubble spectroscopic observations will be used to determine the exact

  7. Remarks on Remnants by Fermions’ Tunnelling from Black Strings

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    Deyou Chen

    2014-01-01

    Full Text Available Hawking’s calculation is unable to predict the final stage of the black hole evaporation. When effects of quantum gravity are taken into account, there is a minimal observable length. In this paper, we investigate fermions’ tunnelling from the charged and rotating black strings. With the influence of the generalized uncertainty principle, the Hawking temperatures are not only determined by the rings, but also affected by the quantum numbers of the emitted fermions. Quantum gravity corrections slow down the increases of the temperatures, which naturally leads to remnants left in the evaporation.

  8. XMM-Newton Observations of Two Candidate Supernova Remnants

    OpenAIRE

    Kargaltsev, O.; Schmitt, B. M.; Pavlov, G. G.; Misanovic, Z.

    2011-01-01

    Candidate supernova remnants G23.5+0.1 and G25.5+0.0 were observed by XMM-Newton in the course of a snap-shot survey of plerionic and composite SNRs in the Galactic plane. In the field of G23.5+0.1, we detected an extended source, ~3' in diameter, which we tentatively interpret as a pulsar-wind nebula (PWN) of the middle-aged radio pulsar B1830-08. Our analysis suggests an association between PSR B1830-08 and the surrounding diffuse radio emission. If the radio emission is due to the SNR, the...

  9. Symbiotic nova eruption of R Aquarii . A geological remnant?

    Science.gov (United States)

    Tanabe, Kenji; Motizuki, Yuko

    An evidence of possible nova eruption of the symbiotic star R Aquarii, which was recorded in the historical books by ancient Korean astronomers, is discovered in an antarctic ice core as a nitrate ion concentration (spikes) .These spikes , separated by only one year,are as prominent as other spikes of the recorded supernovae in 11th century .These set of two spikes do not coincide with any supernova remnants but successfully coincide with the nova eruption of R Aquarii in the year of A.D. 1073 and A.D.1074 in the Korean historical records.

  10. Expansion of the Optical Remnant from Tycho’s Supernova

    Science.gov (United States)

    Putko, Joseph; Winkler, P. Frank; Blair, William P.

    2015-01-01

    Tycho's supernova remnant (SNR) is the expanding remnant from SN 1572, the penultimate Galactic supernova to have been recorded by contemporary observers. Its optical light is almost exclusively faint hydrogen Balmer emission around the periphery of the SNR, produced where fast nonradiative shocks encounter partly neutral preshock interstellar material. A variety of filaments, presumably thin sheets oriented tangentially, surround about one-third of the radio/X-ray shell. We have used CCD images, taken from KPNO over seven epochs from 1986 to 2009, to give the first optical expansion measurement of Tycho's SNR of the CCD era. Thirty filaments were identified and measured; the majority of them are at or near the remnant's outer rim and have proper motions from 0.19‧‧ ± 0.01‧‧ yr-1 to 0.26‧‧ ± 0.02‧‧ yr-1. The associated expansion indices, defined as the ratio of the current expansion rate to the historical mean, range from 0.35 ± 0.03 to 0.52 ± 0.05. Our measurements are consistent with those from the classic study by Kamper & van den Bergh (1978, ApJ, 224, 851) for the same filaments, but the CCD measurements have higher precision, and we have measured several additional fainter filaments. For direct comparison with X-ray and radio measurements, we selected the subset of optical filaments lying exactly at the outer rim, as identified in Chandra and VLA images. Considering only these filaments, virtually all have expansion indices greater than 0.40, the Sedov value. In addition to the rim filaments, there are several seen in the interior (in projection) that have smaller proper motions; these may have been decelerated, and/or they could be directed non-tangentially. Our final epoch of images, taken from the 3.5m WIYN telescope in 2009, reveals previously undetected extremely faint optical emission surrounding well over half of the remnant shell. This newly detected faint emission agrees well with the limb as defined in X-ray and radio images

  11. Development of a Model of Chronic Kidney Disease in the C57BL/6 Mouse with Properties of Progressive Human CKD

    Directory of Open Access Journals (Sweden)

    Zahraa Mohammed-Ali

    2015-01-01

    Full Text Available Chronic kidney disease (CKD is a major healthcare problem with increasing prevalence in the population. CKD leads to end stage renal disease and increases the risk of cardiovascular disease. As such, it is important to study the mechanisms underlying CKD progression. To this end, an animal model was developed to allow the testing of new treatment strategies or molecular targets for CKD prevention. Many underlying risk factors result in CKD but the disease itself has common features, including renal interstitial fibrosis, tubular epithelial cell loss through apoptosis, glomerular damage, and renal inflammation. Further, CKD shows differences in prevalence between the genders with premenopausal women being relatively resistant to CKD. We sought to develop and characterize an animal model with these common features of human CKD in the C57BL/6 mouse. Mice of this genetic background have been used to produce transgenic strains that are commercially available. Thus, a CKD model in this strain would allow the testing of the effects of numerous genes on the severity or progression of CKD with minimal cost. This paper describes such a mouse model of CKD utilizing angiotensin II and deoxycorticosterone acetate as inducers.

  12. The Three-Dimensional Expansion of the Ejecta from Tycho's Supernova Remnant

    Science.gov (United States)

    Williams, Brian J.; Coyle, Nina; Yamaguchi, Hiroya; DePasquale, Joseph M.; Seitenzahl, Ivo Rolf; Hewitt, John W.; Blondin, John M.; Borkowski, Kazimierz J.; Ghavamian, Parviz; Petre, Robert; Reynolds, Stephen P.

    2017-08-01

    We present the first three-dimensional measurements of the velocity of various ejecta knots in Tycho's supernova remnant, known to result from a Type Ia explosion. Chandra X-ray observations over a 12-year baseline from 2003 to 2015 allow us to measure the proper motion of nearly 60 ``tufts'' of Si-rich ejecta, giving us the velocity in the plane of the sky. For the line of sight velocity, we use two different methods: a non-equilibrium ionization model fit to the strong Si and S lines in the 1.2-2.8 keV regime, and a fit consisting of a series of Gaussian lines. These methods give consistent results, allowing us to determine the red or blue shift of each of the knots. Assuming a distance of 3.5 kpc, we find total velocities that range from 2400 to 6600 km s$^{-1}$, with a mean of 4430 km s$^{-1}$. We find several regions where the ejecta knots have overtaken the forward shock. These regions have proper motions in excess of 6000 km s$^{-1}$. Some Type Ia supernova explosion models predict a velocity asymmetry in the ejecta. We find no such velocity asymmetries in Tycho, and discuss our findings in light of various explosion models, favoring those delayed detonation models with relatively vigorous and symmetrical deflagrations. Finally, we compare measurements with models of the remnant's evolution that include both smooth and clumpy ejecta profiles, finding that both ejecta profiles can be accommodated by the observations.

  13. A developmentally plastic adult mouse kidney cell line spontaneously generates multiple adult kidney structures

    Energy Technology Data Exchange (ETDEWEB)

    Webb, Carol F., E-mail: carol-webb@omrf.org [Department of Cell Biology, University of Oklahoma Health Sciences Center, Oklahoma City, OK (United States); Immunobiology and Cancer Research, Oklahoma Medical Research Foundation, Oklahoma City, OK (United States); Department of Microbiology and Immunology, University of Oklahoma Health Sciences Center, Oklahoma City, OK (United States); Ratliff, Michelle L., E-mail: michelle-ratliff@omrf.org [Immunobiology and Cancer Research, Oklahoma Medical Research Foundation, Oklahoma City, OK (United States); Powell, Rebecca, E-mail: rebeccapowell@gmail.com [Department of Cell Biology, University of Oklahoma Health Sciences Center, Oklahoma City, OK (United States); Wirsig-Wiechmann, Celeste R., E-mail: celeste-wirsig@ouhsc.edu [Department of Cell Biology, University of Oklahoma Health Sciences Center, Oklahoma City, OK (United States); Lakiza, Olga, E-mail: olga-lakiza@ouhsc.edu [Department of Cell Biology, University of Oklahoma Health Sciences Center, Oklahoma City, OK (United States); Obara, Tomoko, E-mail: tomoko-obara@ouhsc.edu [Department of Cell Biology, University of Oklahoma Health Sciences Center, Oklahoma City, OK (United States)

    2015-08-07

    Despite exciting new possibilities for regenerative therapy posed by the ability to induce pluripotent stem cells, recapitulation of three-dimensional kidneys for repair or replacement has not been possible. ARID3a-deficient mouse tissues generated multipotent, developmentally plastic cells. Therefore, we assessed the adult mouse ARID3a−/− kidney cell line, KKPS5, which expresses renal progenitor surface markers as an alternative cell source for modeling kidney development. Remarkably, these cells spontaneously developed into multicellular nephron-like structures in vitro, and engrafted into immunocompromised medaka mesonephros, where they formed mouse nephron structures. These data implicate KKPS5 cells as a new model system for studying kidney development. - Highlights: • An ARID3a-deficient mouse kidney cell line expresses multiple progenitor markers. • This cell line spontaneously forms multiple nephron-like structures in vitro. • This cell line formed mouse kidney structures in immunocompromised medaka fish kidneys. • Our data identify a novel model system for studying kidney development.

  14. Relationship between Fibroblast Growth Factor 23 and Biochemical and Bone Histomorphometric Alterations in a Chronic Kidney Disease Rat Model Undergoing Parathyroidectomy.

    Directory of Open Access Journals (Sweden)

    Hung-Wei Liao

    Full Text Available Phosphate burden in chronic kidney disease (CKD leads to elevated serum fibroblast factor-23 (FGF-23 levels, secondary hyperparathyroidism and chronic kidney disease-mineral bone disorder (CKD-MBD. However dissociated hyperphosphatemia and low serum FGF-23 concentrations have been observed in experimentally parathyoridectomized rats. The relationships between serum mineral, hormone, and bone metabolism may be altered in the presence of CKD. The aim of our study was to investigate whether a consistent relationship existed between serum FGF-23 levels, specific serum biochemical markers, and histomorphometric parameters of bone metabolism in a parathyroidectomized CKD animal model.Sprague Dawley rats were divided into 3 groups: parathyroidectomy (PTX and CKD (PTX+CKD, 9 rats, CKD without PTX (CKD, 9 rats, and neither PTX nor CKD (sham-operated control, 8 rats; CKD was induced by partial nephrectomy. At 8 weeks after partial nephrectomy, serum biomarkers were measured. Bone histomorphometries of the distal femoral metaphyseal bone were analyzed. The mean serum FGF-23 levels and mean bone formation rate were the highest in the CKD group and the lowest in the PTX+CKD group. Bone volume parameters increased significantly in the PTX+CKD group. Pearson's correlation revealed that serum FGF-23 levels associated with those of intact parathyroid hormone, phosphate, collagen type I C-telopeptide, and calcium. Univariate linear regression showed that serum FGF-23 values correlated with bone formation rate, bone volume, and osteoid parameters. Stepwise multivariate regression analysis revealed that circulating FGF-23 values were independently associated with bone volume and thickness (β = -0.737; p < 0.001 and β = -0.526; p = 0.006, respectively. Serum parathyroid hormone levels independently correlated with bone formation rate (β = 0.714; p < 0.001 while collagen type I C-telopeptide levels correlated with osteoid parameter.Serum FGF-23 levels

  15. Effects of the Administration of 25(OH) Vitamin D3 in an Experimental Model of Chronic Kidney Disease in Animals Null for 1-Alpha-Hydroxylase.

    Science.gov (United States)

    Torremadé, Noelia; Bozic, Milica; Goltzman, David; Fernandez, Elvira; Valdivielso, José M

    2017-01-01

    The final step in vitamin D activation is catalyzed by 1-alpha-hydroxylase (CYP27B1). Chronic kidney disease (CKD) is characterized by low levels of both 25(OH)D3 and 1,25(OH)2D3 provoking secondary hyperparathyroidism (2HPT). Therefore, treatments with active or native vitamin D compounds are common in CKD to restore 25(OH)D3 levels and also to decrease PTH. This study evaluates the dose of 25(OH)D3 that restores parathyroid hormone (PTH) and calcium levels in a model of CKD in CYP27B1-/- mice. Furthermore, we compare the safety and efficacy of the same dose in CYP27B1+/+ animals. The dose needed to decrease PTH levels in CYP27B1-/- mice with CKD was 50 ng/g. That dose restored blood calcium levels without modifying phosphate levels, and increased the expression of genes responsible for calcium absorption (TRPV5 and calbindinD- 28K in the kidney, TRPV6 and calbindinD-9k in the intestine). The same dose of 25(OH)D3 did not modify PTH in CYP27B1+/+ animals with CKD. Blood calcium remained normal, while phosphate increased significantly. Blood levels of 25(OH)D3 in CYP27B1-/- mice were extremely high compared to those in CYP27B1+/+ animals. CYP27B1+/+ animals with CKD showed increases in TRPV5, TRPV6, calbindinD-28K and calbindinD-9K, which were not further elevated with the treatment. Furthermore, CYP27B1+/+ animals displayed an increase in vascular calcification. We conclude that the dose of 25(OH)D3 effective in decreasing PTH levels in CYP27B1-/- mice with CKD, has a potentially toxic effect in CYP27B1+/+ animals with CKD.

  16. Remnant trees affect species composition but not structure of tropical second-growth forest.

    Science.gov (United States)

    Sandor, Manette E; Chazdon, Robin L

    2014-01-01

    Remnant trees, spared from cutting when tropical forests are cleared for agriculture or grazing, act as nuclei of forest regeneration following field abandonment. Previous studies on remnant trees were primarily conducted in active pasture or old fields abandoned in the previous 2-3 years, and focused on structure and species richness of regenerating forest, but not species composition. Our study is among the first to investigate the effects of remnant trees on neighborhood forest structure, biodiversity, and species composition 20 years post-abandonment. We compared the woody vegetation around individual remnant trees to nearby plots without remnant trees in the same second-growth forests ("control plots"). Forest structure beneath remnant trees did not differ significantly from control plots. Species richness and species diversity were significantly higher around remnant trees. The species composition around remnant trees differed significantly from control plots and more closely resembled the species composition of nearby old-growth forest. The proportion of old-growth specialists and generalists around remnant trees was significantly greater than in control plots. Although previous studies show that remnant trees may initially accelerate secondary forest growth, we found no evidence that they locally affect stem density, basal area, and seedling density at later stages of regrowth. Remnant trees do, however, have a clear effect on the species diversity, composition, and ecological groups of the surrounding woody vegetation, even after 20 years of forest regeneration. To accelerate the return of diversity and old-growth forest species into regrowing forest on abandoned land, landowners should be encouraged to retain remnant trees in agricultural or pastoral fields.

  17. Formation of the remnant close to Planck scale and the Schwarzschild black hole with global monopole

    Science.gov (United States)

    Li, Hui-Ling; Chen, Shuai-Ru

    2017-10-01

    In this paper, we use the generalized uncertainty principle (GUP) and quantum tunneling method to research the formation of the remnant from a Schwarzschild black hole with global monopole. Based on the corrected Hamilton-Jacobi equation, the corrections to the Hawking temperature, heat capacity and entropy are calculated. We not only find the remnant close to Planck scale by employing GUP, but also research the thermodynamic stability of the black hole remnant according to the phase transition and heat capacity.

  18. The soft X-ray spectrum of the Vela supernova remnant

    Science.gov (United States)

    Kahn, S. M.; Brodie, J.; Bowyer, S.; Charles, P. A.

    1983-01-01

    An X-ray spectrum of a major fraction of the Vela supernova remnant has been obtained during scanning observations with the low energy proportional counters of the A-2 experiment, flown on HEAO 1. A deconvolution analysis of the data shows that the spectrum exhibits pronounced line emission near 0.6 keV due primarily to oxygen ions. Model fits using the Raymond-Smith hot plasma emission calculations indicate that the spectrum can be well described by a model involving two collisional equilibrium components with temperatures of 2.4 x 10 to the 6th and 1.9 x 10 to the 7th K, respectively. The abundances of oxygen and iron are found to be constrained to lie near their normal cosmic values.

  19. Nanomedicines for kidney diseases.

    Science.gov (United States)

    Williams, Ryan M; Jaimes, Edgar A; Heller, Daniel A

    2016-10-01

    Nanomedicines have been the subject of great interest for the treatment, diagnosis, and research of disease; however, few specifically address kidney disorders. Nanotechnology can confer significant benefits to medicine, such as the targeted delivery of drugs to specific tissues. Nanomedicines in the clinic have increased drug solubility, reduced off-target side effects, and provided novel diagnostic tools. There is an increasing cohort of nanomaterials that may have implications for kidney disease. Here, we review nanomaterial properties that are potentially applicable to kidney research and therapy, and we highlight clinical areas of need that may benefit from kidney nanomedicines. Copyright © 2016 International Society of Nephrology. Published by Elsevier Inc. All rights reserved.

  20. Clinical characteristics of potential kidney donors with asymptomatic kidney stones

    OpenAIRE

    Lorenz, Elizabeth C.; Lieske, John C.; Vrtiska, Terri J.; Krambeck, Amy E.; Li, Xujian; Bergstralh, Eric J.; Melton, L. Joseph; Rule, Andrew D.

    2011-01-01

    Background. Patients with symptomatic kidney stones are characterized by older age, male gender, white race, hypertension, obesity, metabolic syndrome and chronic kidney disease. Whether these characteristics differ in patients with asymptomatic kidney stones is unknown.

  1. Violent failure of a remnant in a deep South African gold mine

    CSIR Research Space (South Africa)

    Durrheim, RJ

    1998-04-15

    Full Text Available of the rockburst (Fig. 3) the VCR is a 1?2-m-thick clast- to matrix-supported conglom- erate intercalated with minor quartzite, dipping to the south at 20?. Volcanic rocks of the Alberton Porphyry Formation (known informally as the ?hard lava? and part... in an L-shaped peninsular remnant. At the time of the rockburst the width of the remnant ranged from 8?12 m (see Fig. 6). If the strength of one limb of the remnant was exceeded, it is likely that the entire remnant would have failed simultaneously...

  2. Sparing the anterior cruciate ligament remnant: is it worth the hassle?

    Science.gov (United States)

    Papalia, Rocco; Franceschi, Francesco; Vasta, Sebastiano; Di Martino, Alberto; Maffulli, Nicola; Denaro, Vincenzo

    2012-01-01

    Anterior cruciate ligament (ACL) rupture is the most common surgically treated ligament injury. Many efforts have been taken to reconstruct it as anatomically as possible to restore knee stability and, possibly, prevent knee osteoarthritis. A literature search was performed using the isolated or combined keywords 'ACL augmentation remnant', 'ACL reconstruction and remnant and stump', 'ACL reconstruction and remnant and stump preserving and stability' and 'ACL remnant complete tear' with no limit regarding the year of publication. We identified seven published studies. The ACL remnant might accelerate the vascularization and the ligamentization of the graft and contribute to faster graft innervation leading to a better proprioception. The role of the ACL remnant is debated, because, although it may increase the risk of impingement and the formation of cyclops lesion, its preservation can improve proprioception, biomechanical functions and vascularity. However, the current assessment methods to assess proprioception, vascularization and the ligamentization do not lead to hard evidence that preservation of the remnant confers clinically relevant advantages over its excision. The ACL remnant has been demonstrated in experimental studies to have a role in improving revascularization, ligamentization and reinnervation of the graft, but these findings are still not supported by clinical findings. A more direct way to assess proprioceptive function after ACL reconstruction and appropriately conducted powered and rigorously prospective randomized double-blind studies comparing the clinical outcomes of excising the remnant to leaving it in situ are necessary.

  3. The Radio Remnant of Supernova 1987A - A Broader View

    Science.gov (United States)

    Zanardo, G.; Staveley-Smith, L.; Ng, C.-Y.; Indebetouw, R.; Matsuura, M.; Gaensler, B. M.; Tzioumis, A. K.

    2017-02-01

    Supernova remnants (SNRs) are powerful particle accelerators. As a supernova (SN) blast wave propagates through the circumstellar medium (CSM), electrons and protons scatter across the shock and gain energy by entrapment in the magnetic field. The accelerated particles generate further magnetic field fluctuations and local amplification, leading to cosmic ray production. The wealth of data from Supernova 1987A is providing a template of the SN-CSM interaction, and an important guide to the radio detection and identification of core-collapse SNe based on their spectral properties. Thirty years after the explosion, radio observations of SNR 1987A span from 70 MHz to 700 GHz. We review extensive observing campaigns with the Australia Telescope Compact Array (ATCA) and the Atacama Large Millimeter/submillimeter Array (ALMA), and follow-ups with other radio telescopes. Observations across the radio spectrum indicate rapid changes in the remnant morphology, while current ATCA and ALMA observations show that the SNR has entered a new evolutionary phase.

  4. Tycho's Remnant Provides Shocking Evidence for Cosmic Rays

    Science.gov (United States)

    2005-09-01

    Astronomers have found compelling evidence that a supernova shock wave has produced a large amount of cosmic rays, particles of mysterious origin that constantly bombard the Earth. This discovery, made with NASA's Chandra X-ray Observatory, supports theoretical arguments that shock waves from stellar explosions may be a primary source of cosmic rays. This finding is important for understanding the origin of cosmic rays, which are atomic nuclei that strike the Earth's atmosphere with very high energies. Scientists believe that some are produced by flares on the Sun, and others by similar events on other stars, or pulsars or black hole accretion disks. But, one of the prime suspects has been supernova shock waves. Now, a team of astronomers has used Chandra observations of Tycho's supernova remnant to strengthen the case for this explanation. "With only a single object involved we can't state with confidence that supernova shock waves are the primary source of cosmic rays," said John P. Hughes of Rutgers University in Piscataway, New Jersey, and coauthor of a report to be published in an upcoming issue of The Astrophysical Journal. "What we have done is present solid evidence that the shock wave in at least one supernova remnant has accelerated nuclei to cosmic ray energies." In the year 1572, the Danish astronomer Tycho Brahe observed and studied the sudden appearance of a bright "new star" in the constellation Cassiopeia. Now known as Tycho's supernova remnant, the event created a sensation in Tycho's time because it exploded the myth that stars never change. Four centuries later, the Chandra results on Tycho's remnant show that some modern ideas of the aftermath of supernova explosions may have to be revised. The report by Hughes and colleagues demonstrates that the shock wave produced by the explosive disruption of the star behaves in a way that cannot be explained by the standard theory. The supernova debris is observed to expand at a speed of about six million

  5. Destruction of Interstellar Dust in Evolving Supernova Remnant Shock Waves

    Science.gov (United States)

    Slavin, Jonathan D.; Dwek, Eli; Jones, Anthony P.

    2015-01-01

    Supernova generated shock waves are responsible for most of the destruction of dust grains in the interstellar medium (ISM). Calculations of the dust destruction timescale have so far been carried out using plane parallel steady shocks, however that approximation breaks down when the destruction timescale becomes longer than that for the evolution of the supernova remnant (SNR) shock. In this paper we present new calculations of grain destruction in evolving, radiative SNRs. To facilitate comparison with the previous study by Jones et al. (1996), we adopt the same dust properties as in that paper. We find that the efficiencies of grain destruction are most divergent from those for a steady shock when the thermal history of a shocked gas parcel in the SNR differs significantly from that behind a steady shock. This occurs in shocks with velocities 200 km s(exp -1) for which the remnant is just beginning to go radiative. Assuming SNRs evolve in a warm phase dominated ISM, we find dust destruction timescales are increased by a factor of approximately 2 compared to those of Jones et al. (1996), who assumed a hot gas dominated ISM. Recent estimates of supernova rates and ISM mass lead to another factor of approximately 3 increase in the destruction timescales, resulting in a silicate grain destruction timescale of approximately 2-3 Gyr. These increases, while not able resolve the problem of the discrepant timescales for silicate grain destruction and creation, are an important step towards understanding the origin, and evolution of dust in the ISM.

  6. FERMI LARGE AREA TELESCOPE OBSERVATION OF SUPERNOVA REMNANT S147

    Energy Technology Data Exchange (ETDEWEB)

    Katsuta, J.; Uchiyama, Y.; Tanaka, T.; Tajima, H.; Bechtol, K.; Funk, S.; Lande, J. [W. W. Hansen Experimental Physics Laboratory, Kavli Institute for Particle Astrophysics and Cosmology, Department of Physics and SLAC National Accelerator Laboratory, Stanford University, Stanford, CA 94305 (United States); Ballet, J. [Laboratoire AIM, CEA-IRFU/CNRS/Universite Paris Diderot, Service d' Astrophysique, CEA Saclay, 91191 Gif sur Yvette (France); Hanabata, Y. [Department of Physical Sciences, Hiroshima University, Higashi-Hiroshima, Hiroshima 739-8526 (Japan); Lemoine-Goumard, M. [Universite Bordeaux 1, CNRS/IN2p3, Centre d' Etudes Nucleaires de Bordeaux Gradignan, 33175 Gradignan (France); Takahashi, T., E-mail: katsuta@slac.stanford.edu, E-mail: uchiyama@slac.stanford.edu [Institute of Space and Astronautical Science, Japanese Aerospace Exploration Agency, 3-1-1 Yoshinodai, Chuo-ku, Sagamihara, Kanagawa 252-5210 (Japan)

    2012-06-20

    We present an analysis of gamma-ray data obtained with the Large Area Telescope on board the Fermi Gamma-ray Space Telescope in the region around supernova remnant (SNR) S147 (G180.0-1.7). A spatially extended gamma-ray source detected in an energy range of 0.2-10 GeV is found to coincide with SNR S147. We confirm its spatial extension at >5{sigma} confidence level. The gamma-ray flux is (3.8 {+-} 0.6) Multiplication-Sign 10{sup -8} photons cm{sup -2} s{sup -1}, corresponding to a luminosity of 1.3 Multiplication-Sign 10{sup 34} (d/1.3 kpc){sup 2} erg s{sup -1} in this energy range. The gamma-ray emission exhibits a possible spatial correlation with the prominent H{alpha} filaments of SNR S147. There is no indication that the gamma-ray emission comes from the associated pulsar PSR J0538+2817. The gamma-ray spectrum integrated over the remnant is likely dominated by the decay of neutral {pi} mesons produced through the proton-proton collisions in the filaments. The reacceleration of the pre-existing cosmic rays and subsequent adiabatic compression in the filaments is sufficient to provide the energy density required of high-energy protons.

  7. High order shear horizontal modes for minimum remnant thickness.

    Science.gov (United States)

    Belanger, Pierre

    2014-04-01

    Thickness mapping in aging structures suffering from corrosion is challenging especially when the structure is only partially accessible. In plates the high order shear horizontal guided wave modes all have a cutoff frequency thickness product below which they cannot propagate. This property is potentially attractive to estimate the minimum remnant thickness between two transducers. When using a source and a sensor array it is possible to control the number of modes being excited and the size of the region interrogated by the technique. Finite element simulations were used to show that by exciting multiple guided wave modes simultaneously and identifying which modes are received by a sensor array it is possible to estimate the minimum remaining thickness along the propagation path. Initial experimental results showed excellent agreement with the finite element simulations when the plate is uniform and with a thickness reduction between the source and the sensor arrays the minimum remnant thickness was underestimated by approximately 20%. Copyright © 2014 Elsevier B.V. All rights reserved.

  8. Slab remnants beneath the Baja California peninsula: Seismic constraints and tectonic implications

    Science.gov (United States)

    Paulssen, Hanneke; de Vos, Denise

    2017-11-01

    The formation of the Gulf of California has been related to the cessation of subduction of the Guadalupe and Magdalena microplates. Various studies have identified features that point to the presence of a slab remnant beneath the Baja California peninsula, but its depth range and lateral extent remained unclear. In this study we used surface wave phase velocity and receiver function data of NARS-Baja stations around the Gulf of California to better constrain the location of the slab. For stations in central and southern Baja California the shear velocity models show an upper mantle high-velocity layer with its top in the depth range from 115 to 135km and a thickness varying between roughly 40 and 60km. These high-velocity anomalies are interpreted as subducted slab remnants. In contrast, the models for the northern peninsula show no slab signature. This change directly correlates with the variation in relative motion between the Baja California peninsula and the Pacific plate as measured by GPS data. It is inferred that the stalled slab fragments beneath the peninsula produce strong coupling between Baja California and the Pacific plate. The shear velocity models for stations on the Mexican mainland show a layer of higher velocities above a low-velocity upper mantle. In the North, the low-velocity mantle, starting at a depth of 40km, is associated with upwelling as suggested by previous studies. Further south, the transition from higher to lower mantle velocities occurs around 80km depth, which is a typical value for the lithosphere-asthenosphere boundary. Furthermore, the models show strong crustal thinning towards the gulf, both from the peninsula as well as from the Mexican mainland.

  9. Spitzer observations of the type IA supernova remnant N103B: Kepler's older cousin?

    Energy Technology Data Exchange (ETDEWEB)

    Williams, Brian J. [NASA Goddard Space Flight Center, Greenbelt, MD 20771 (United States); Borkowski, Kazimierz J.; Reynolds, Stephen P. [Physics Department, North Carolina State University, Raleigh, NC 27695-8202 (United States); Ghavamian, Parviz [Department of Physics, Chemistry, and Geosciences, Towson University, Towson, MD 21252 (United States); Raymond, John C. [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States); Long, Knox S. [STScI, 3700 San Martin Drive, Baltimore, MD 21218 (United States); Blair, William P. [Department of Physics and Astronomy, Johns Hopkins University, 3400 North Charles Street, Baltimore, MD 21218-2686 (United States); Sankrit, Ravi [SOFIA Science Center, NASA AMES Research Center, M/S N211-3, Moffett Field, CA 94035 (United States); Winkler, P. Frank [Department of Physics, Middlebury College, Middlebury, VT 05753 (United States); Hendrick, Sean P., E-mail: brian.j.williams@nasa.gov [Physics Department, Millersville University, P.O. Box 1002, Millersville, PA 17551 (United States)

    2014-08-01

    We report results from Spitzer observations of SNR 0509-68.7, also known as N103B, a young Type Ia supernova remnant (SNR) in the Large Magellanic Cloud (LMC) that shows interaction with a dense medium in its western hemisphere. Our images show that N103B has strong IR emission from warm dust in the post-shock environment. The post-shock gas density we derive, 45 cm{sup –3}, is much higher than in other Type Ia remnants in the LMC, though a lack of spatial resolution may bias measurements toward regions of higher than average density. This density is similar to that in Kepler's SNR, a Type Ia interacting with a circumstellar medium (CSM). Optical images show Hα emission along the entire periphery of the western portion of the shock, with [O III] and [S II] lines emitted from a few dense clumps of material where the shock has become radiative. The dust is silicate in nature, though standard silicate dust models fail to reproduce the '18 μm' silicate feature that peaks instead at 17.3 μm. We propose that the dense material is circumstellar material lost from the progenitor system, as with Kepler. If the CSM interpretation is correct, this remnant would become the second member, along with Kepler, of a class of Type Ia remnants characterized by interaction with a dense CSM hundreds of years post-explosion. A lack of N enhancement eliminates symbiotic asymptotic giant branch progenitors. The white dwarf companion must have been relatively unevolved at the time of the explosion.

  10. External validation and clinical utility of a prediction model for 6-month mortality in patients undergoing hemodialysis for end-stage kidney disease.

    Science.gov (United States)

    Forzley, Brian; Er, Lee; Chiu, Helen Hl; Djurdjev, Ognjenka; Martinusen, Dan; Carson, Rachel C; Hargrove, Gaylene; Levin, Adeera; Karim, Mohamud

    2018-02-01

    End-stage kidney disease is associated with poor prognosis. Health care professionals must be prepared to address end-of-life issues and identify those at high risk for dying. A 6-month mortality prediction model for patients on dialysis derived in the United States is used but has not been externally validated. We aimed to assess the external validity and clinical utility in an independent cohort in Canada. We examined the performance of the published 6-month mortality prediction model, using discrimination, calibration, and decision curve analyses. Data were derived from a cohort of 374 prevalent dialysis patients in two regions of British Columbia, Canada, which included serum albumin, age, peripheral vascular disease, dementia, and answers to the "the surprise question" ("Would I be surprised if this patient died within the next year?"). The observed mortality in the validation cohort was 11.5% at 6 months. The prediction model had reasonable discrimination (c-stat = 0.70) but poor calibration (calibration-in-the-large = -0.53 (95% confidence interval: -0.88, -0.18); calibration slope = 0.57 (95% confidence interval: 0.31, 0.83)) in our data. Decision curve analysis showed the model only has added value in guiding clinical decision in a small range of threshold probabilities: 8%-20%. Despite reasonable discrimination, the prediction model has poor calibration in this external study cohort; thus, it may have limited clinical utility in settings outside of where it was derived. Decision curve analysis clarifies limitations in clinical utility not apparent by receiver operating characteristic curve analysis. This study highlights the importance of external validation of prediction models prior to routine use in clinical practice.

  11. Parallel analysis of mRNA and microRNA microarray profiles to explore functional regulatory patterns in polycystic kidney disease: using PKD/Mhm rat model.

    Directory of Open Access Journals (Sweden)

    Harsh Dweep

    Full Text Available Autosomal polycystic kidney disease (ADPKD is a frequent monogenic renal disease, characterised by fluid-filled cysts that are thought to result from multiple deregulated pathways such as cell proliferation and apoptosis. MicroRNAs (miRNAs are small non-coding RNAs that regulate the expression of many genes associated with such biological processes and human pathologies. To explore the possible regulatory role of miRNAs in PKD, the PKD/Mhm (cy/+ rat, served as a model to study human ADPKD. A parallel microarray-based approach was conducted to profile the expression changes of mRNAs and miRNAs in PKD/Mhm rats. 1,573 up- and 1,760 down-regulated genes were differentially expressed in PKD/Mhm. These genes are associated with 17 pathways (such as focal adhesion, cell cycle, ECM-receptor interaction, DNA replication and metabolic pathways and 47 (e.g., cell proliferation, Wnt and Tgfβ signaling Gene Ontologies. Furthermore, we found the similar expression patterns of deregulated genes between PKD/Mhm (cy/+ rat and human ADPKD, PKD1(L3/L3, PKD1(-/-, Hnf1α-deficient, and Glis2(lacZ/lacZ models. Additionally, several differentially regulated genes were noted to be target hubs for miRNAs. We also obtained 8 significantly up-regulated miRNAs (rno-miR-199a-5p, -214, -146b, -21, -34a, -132, -31 and -503 in diseased kidneys of PKD/Mhm rats. Additionally, the binding site overrepresentation and pathway enrichment analyses were accomplished on the putative targets of these 8 miRNAs. 7 out of these 8 miRNAs and their possible interactions have not been previously described in ADPKD. We have shown a strong overlap of functional patterns (pathways between deregulated miRNAs and mRNAs in the PKD/Mhm (cy/+ rat model. Our findings suggest that several miRNAs may be associated in regulating pathways in ADPKD. We further describe novel miRNAs and their possible targets in ADPKD, which will open new avenues to understand the pathogenesis of human ADPKD. Furthermore

  12. Autosomal Dominant Polycystic Kidney Disease

    Science.gov (United States)

    ... RePORT NIH Fact Sheets Home > Autosomal Dominant Polycystic Kidney Disease Small Text Medium Text Large Text Autosomal Dominant Polycystic Kidney Disease YESTERDAY Autosomal Dominant Polycystic Kidney Disease (ADPKD) resulted ...

  13. Kidney stones - self-care

    Science.gov (United States)

    ... this page: //medlineplus.gov/ency/patientinstructions/000135.htm Kidney stones - self-care To use the sharing features on ... you how to do this. What is a Kidney Stone? A kidney stone is a solid piece of ...

  14. Wound morbidity after kidney transplant

    NARCIS (Netherlands)

    Fockens, M. Matthijs; Alberts, Victor P.; Bemelman, Frederike J.; van der Pant, Karlijn A. M. I.; Idu, Mirza M.

    2015-01-01

    Wound morbidity is an important surgical complication after kidney transplant. To assess risk factors for postoperative wound complications and the impact of such complications on outcomes of kidney transplant. Retrospectively, 108 consecutive kidney transplant patients between January 2010 and

  15. Remnant colloform pyrite at the haile gold deposit, South Carolina: A textural key to genesis

    Science.gov (United States)

    Foley, N.; Ayuso, R.A.; Seal, R.R.

    2001-01-01

    Auriferous iron sulfide-bearing deposits of the Carolina slate belt have distinctive mineralogical and textural features-traits that provide a basis to construct models of ore deposition. Our identification of paragenetically early types of pyrite, especially remnant colloform, crustiform, and layered growth textures of pyrite containing electrum and pyrrhotite, establishes unequivocally that gold mineralization was coeval with deposition of host rocks and not solely related to Paleozoic tectonic events. Ore horizons at the Haile deposit, South Carolina, contain many remnants of early pyrite: (1) fine-grained cubic pyrite disseminated along bedding; (2) fine- grained spongy, rounded masses of pyrite that may envelop or drape over pyrite cubes; (3) fragments of botryoidally and crustiform layered pyrite, and (4) pyritic infilling of vesicles and pumice. Detailed mineral chemistry by petrography, microprobe, SEM, and EDS analysis of replaced pumice and colloform structures containing both arsenic compositional banding and electrum points to coeval deposition of gold and the volcanic host rocks and, thus, confirms a syngenetic origin for the gold deposits. Early pyrite textures are present in other major deposits of the Carolina slate belt, such as Ridgeway and Barite Hill, and these provide strong evidence for models whereby the sulfide ores formed prior to tectonism. The role of Paleozoic metamorphism was to remobilize and concentrate gold and other minerals in structurally prepared sites. Recognizing the significance of paragenetically early pyrite and gold textures can play an important role in distinguishing sulfide ores that form in volcanic and sedimentary environments from those formed solely by metamorphic processes. Exploration strategies applied to the Carolina slate belt and correlative rocks in the eastern United States in the Avalonian basement will benefit from using syngenetic models for gold mineralization.

  16. The Progenitor-Remnant Connection of Neutrino-Driven Supernovae Across the Stellar Mass Range

    Science.gov (United States)

    Ertl, Thomas

    2017-11-01

    We perform hydrodynamic supernova (SN) simulations in spherical symmetry for progenitor models with solar metallicity across the stellar mass range from 9.0 to 120 M ⊙ to explore the progenitor-explosion and progenitor-remnant connections based on the neutrino-driven mechanism. We use an approximative treatment of neutrino transport and replace the high-density interior of the neutron star (NS) by an inner boundary condition based on an analytic proto-NS core-cooling model, whose free parameters are chosen to reproduce the observables of SN 1987A and the Crab SN for theoretical models of their progenitor stars. Judging the fate of a massive star, either a neutron star (NS) or a black hole (BH), solely by its structure prior to collapse has been ambiguous. Our work and previous attempts find a non-monotonic variation of successful and failed supernovae with zero-age main-sequence mass. We identify two parameters based on the ``critical luminosity'' concept for neutrino-driven explosions, which in combination allows for a clear separation of exploding and non-exploding cases. Continuing our simulations beyond shock break-out, we are able to determine nucleosynthesis, light curves, explosion energies, and remnant masses. The resulting NS initial mass function has a mean gravitational mass near 1.4 M ⊙. The average BH mass is about 9 M ⊙ if only the helium core implodes, and 14 M ⊙ if the entire pre-SN star collapses. Only ~10% of SNe come from stars over 20 M ⊙, and some of these are Type Ib or Ic.

  17. Spatially Resolved X-ray Spectroscopy of the Large Magellanic Cloud Supernova Remnant N132D

    Science.gov (United States)

    Plucinsky, Paul; Sharda, Piyush; Gaetz, Terrance; Kashyap, Vinay

    2018-01-01

    We perform detailed X-ray spectroscopy of the brightest Supernova Remnant (SNR), N132D, in the Large Magellanic Cloud (LMC) using observations taken by the Advanced CCD Imaging Spectrometer (ACIS) on the Chandra X-ray Observatory (Chandra). By studying the spectra of regions on the well-defined rim running from NW to NE, we determine an average abundance set for O, Ne, Mg, Si, S and Fe for the local LMC environment. We note that the elements other than Fe and Ne show significant trends across this region, implying they cannot be approximated by a single, constant value. We characterize the blast wave properties and find a simple plane parallel shock model is sufficient to explain the X-ray spectrum of the forward shock moving into ambient LMC material, with a shock velocity near 800 km/s and a shock age of 600-1100 years. We find evidence of enhanced Si near the western blast wave which would imply an asymmetric explosion. We fit a region near the central, optical O-rich knots which exhibits enhanced abundances of O, Ne, Mg, Si, and Fe. Comparison to nucleosynthesis models of the ratios of these elements indicates a progenitor mass of 28-35 solar masses, consistent with most previous estimates. Lastly, we find an intriguing presence of a very hot plasma with a temperature of ~4.5 keV (assuming a non-equilibrium ionization model) to explain the Fe-K emission which is centrally concentrated in the lower half of the remnant.

  18. Lifestyle risk factors and chronic kidney disease.

    Science.gov (United States)

    Vupputuri, Suma; Sandler, Dale P

    2003-11-01

    To examine the effects of lifestyle risk factors such as alcohol consumption, cigarette smoking and body mass index (BMI) on the development of chronic kidney disease. We used a case-control study of 554 hospital cases and 516 age, race, and gender-matched community controls. The main outcome measure was newly-diagnosed chronic kidney disease, assessed by chart review. Self-reported history of alcohol consumption, smoking, and BMI as well as other co-variables were obtained during telephone interviews. Logistic regression models assessed the association between lifestyle risk factors and chronic kidney disease and were adjusted for important co-variables. We found no significant associations between alcohol consumption and chronic kidney disease, with the exception of moonshine, which resulted in an increased risk of chronic kidney disease (including all subtypes). The effects of smoking on chronic kidney disease were inconsistent, but pointed to no appreciable excess risk among smokers. Increasing quartiles of BMI were positively and significantly associated with nephrosclerosis (ORs [95% CI]: 2.5 [1.0-6.0], 2.8 [1.2-6.8] and 4.6 [1.8-11.6], for the second, third, and fourth quartiles of BMI, respectively). Our study revealed a significant positive association between BMI and nephrosclerosis. We did not find an increased risk of chronic kidney disease associated with alcohol or cigarette smoking.

  19. Regenerative Medicine for the Kidney: Renotropic Factors, Renal Stem/Progenitor Cells, and Stem Cell Therapy

    OpenAIRE

    Maeshima, Akito; Nakasatomi, Masao; Nojima, Yoshihisa

    2014-01-01

    The kidney has the capacity for regeneration and repair after a variety of insults. Over the past few decades, factors that promote repair of the injured kidney have been extensively investigated. By using kidney injury animal models, the role of intrinsic and extrinsic growth factors, transcription factors, and extracellular matrix in this process has been examined. The identification of renal stem cells in the adult kidney as well as in the embryonic kidney is an active area of research. Ce...

  20. [Extracorporeal kidney surgery].

    Science.gov (United States)

    Lopatkin, N A

    1983-12-01

    A report is given on the correlation between 50 planned extracorporal kidney operations and the 20 operations actually performed. The reasons for this relation, indications for the operations and operative techniques are discussed. Extracorporal kidney surgery is relatively seldom necessary with strict indication.

  1. Diabetes and Kidney Disease

    Science.gov (United States)

    ... counter medicines. How can I cope with the stress of managing my diabetes? Managing diabetes isn’t always easy. Feeling stressed, ... Learn more about healthy ways to cope with stress . Does diabetic kidney disease get worse over time? Kidney damage from diabetes can get worse over time. However, you can ...

  2. Semiautomated quantitative image analysis of glomerular immunohistochemistry markers desmin, vimentin, podocin, synaptopodin and WT-1 in acute and chronic rat kidney disease models.

    Science.gov (United States)

    Funk, J; Ott, V; Herrmann, A; Rapp, W; Raab, S; Riboulet, W; Vandjour, A; Hainaut, E; Benardeau, A; Singer, T; Jacobsen, B

    2016-03-01

    Five different glomerular immunohistochemistry markers were evaluated and compared in four different acute and chronic rat kidney disease models. Progression of glomerular or podocyte damage was shown in the puromycin aminonucleoside nephrosis (PAN) and Zucker fatty/spontaneously hypertensive heart failure F1 hybrid (ZSF1) rat model. Progression and prevention of glomerular damage was demonstrated in the Zucker diabetic fatty (ZDF) and Dahl salt-sensitive (Dahl SS) rat. Immunohistochemistry was performed for desmin, vimentin, podocin, synaptopodin and Wilms tumor protein-1 (WT-1), and evaluation of glomerular immunohistochemistry markers was done by semiautomated quantitative image analysis. We found desmin and WT-1 as the most sensitive markers for podocyte damage in both acute and chronic glomerular damage followed by vimentin, podocin and synaptopodin. We were able to demonstrate that early podocyte damage as shown by increased desmin and vimentin staining together with either a phenotypic podocyte change or podocyte loss (reduced numbers of WT-1-stained podocytes) drives the progression of glomerular damage. This is followed by a reduction in podocyte-specific proteins such as podocin and synaptopodin. Our report describes the different sensitivity of glomerular or podocyte markers and gives future guidance for the selection of the most sensitive markers for efficacy testing of new drugs as well as for the selection of tissue-based toxicity markers for glomerular or podocyte injury. In addition to functional clinical chemistry markers, desmin and WT-1 immunohistochemistry offers reliable and valuable data on the morphologic state of podocytes.

  3. Echocardiographic integrated backscatter for assessing reduction of aortic valve calcifications by R-568 in a rat model of chronic kidney disease.

    Science.gov (United States)

    Roosens, Bram; Bala, Gezim; Droogmans, Steven; Hostens, Jeroen; Somja, Joan; Delvenne, Eléonore; Schiettecatte, Johan; Delvenne, Philippe; Caveliers, Vicky; Lahoutte, Tony; Van Camp, Guy; Cosyns, Bernard

    2013-11-01

    Chronic kidney disease (CKD) and secondary hyper-parathyroidism are associated with calcific aortic valve disease (CAVD). Innovative modalities for imaging CAVD are warranted. Our aim was to use echocardiographic calibrated integrated backscatter (cIB) to quantitatively determine the preventive effect of the calcimimetic R-568 on CAVD in a CKD rat model, and to compare the results with those of micro-computed tomography and histology. Thirty-six male Wistar rats were followed for 7 wk. Rats were divided into four groups with respect to treatment: (1) adenine 0.5% to induce CKD + vehicle; (2) adenine + R-568 (30 mg/kg/d); (3) control, normal diet + vehicle; (4) controls, normal diet + R-568. At week 7, cIB values of the aortic valve were significantly lower in R-568-treated group 2 than in vehicle-treated group 1. This was confirmed by the significantly lower calcified volume observed on micro-computed tomography and the calcified area observed on histology. There were no significant differences in fractional area change and aortic valve area between groups. In conclusion, echocardiographic cIB was able to quantitatively assess a reduction in CAVD by R-568 in a rat model of CKD. Copyright © 2013 World Federation for Ultrasound in Medicine & Biology. Published by Elsevier Inc. All rights reserved.

  4. Amniotic fluid-derived mesenchymal stem cells prevent fibrosis and preserve renal function in a preclinical porcine model of kidney transplantation.

    Science.gov (United States)

    Baulier, Edouard; Favreau, Frederic; Le Corf, Amélie; Jayle, Christophe; Schneider, Fabrice; Goujon, Jean-Michel; Feraud, Olivier; Bennaceur-Griscelli, Annelise; Hauet, Thierry; Turhan, Ali G

    2014-07-01

    It is well known that ischemia/reperfusion injuries strongly affect the success of human organ transplantation. Development of interstitial fibrosis and tubular atrophy is the main deleterious phenomenon involved. Stem cells are a promising therapeutic tool already validated in various ischemic diseases. Amniotic fluid-derived mesenchymal stem cells (af-MSCs), a subpopulation of multipotent cells identified in amniotic fluid, are known to secrete growth factors and anti-inflammatory cytokines. In addition, these cells are easy to collect, present higher proliferation and self-renewal rates compared with other adult stem cells (ASCs), and are suitable for banking. Consequently, af-MSCs represent a promising source of stem cells for regenerative therapies in humans. To determine the efficiency and the safety of af-MSC infusion in a preclinical porcine model of renal autotransplantation, we injected autologous af-MSCs in the renal artery 6 days after transplantation. The af-MSC injection improved glomerular and tubular functions, leading to full renal function recovery and abrogated fibrosis development at 3 months. The strong proof of concept generated by this translational porcine model is a first step toward evaluation of af-MSC-based therapies in human kidney transplantation. ©AlphaMed Press.

  5. Individualized Physical 3-dimensional Kidney Tumor Models Constructed From 3-dimensional Printers Result in Improved Trainee Anatomic Understanding.

    Science.gov (United States)

    Knoedler, Margaret; Feibus, Allison H; Lange, Andrew; Maddox, Michael M; Ledet, Elisa; Thomas, Raju; Silberstein, Jonathan L

    2015-06-01

    To evaluate the effect of 3-dimensionally (3D) printed physical renal models with enhancing masses on medical trainee characterization, localization, and understanding of renal malignancy. Proprietary software was used to import standard computed tomography (CT) cross-sectional imaging into 3D printers to create physical models of renal units with enhancing renal lesions in situ. Six different models were printed from a transparent plastic resin; the normal parenchyma was printed in a clear, translucent plastic, with a red hue delineating the suspicious renal lesion. Medical students, who had completed their first year of training, were given an overview and tasked with completion of RENAL nephrometry scores, separately using CT imaging and 3D models. Trainees were also asked to complete a questionnaire about their experience. Variability between trainees was assessed by intraclass correlation coefficients (ICCs), and kappa statistics were used to compare the trainee to experts. Overall trainee nephrometry score accuracy was significantly improved with the 3D model vs CT scan (P 3D models compared with CT scans to assess the nephrometry score (intraclass correlation coefficient, 0.28 for CT scan vs 0.72 for 3D models). Qualitative evaluation with questionnaires filled out by the trainees further confirmed that the 3D models improved their ability to understand and conceptualize the renal mass. Physical 3D models using readily available printing techniques improve trainees' understanding and characterization of individual patients' enhancing renal lesions. Published by Elsevier Inc.

  6. Diabetic kidney disease

    DEFF Research Database (Denmark)

    Thomas, Merlin C; Brownlee, Michael; Susztak, Katalin

    2015-01-01

    The kidney is arguably the most important target of microvascular damage in diabetes. A substantial proportion of individuals with diabetes will develop kidney disease owing to their disease and/or other co-morbidity, including hypertension and ageing-related nephron loss. The presence and severity...... of chronic kidney disease (CKD) identify individuals who are at increased risk of adverse health outcomes and premature mortality. Consequently, preventing and managing CKD in patients with diabetes is now a key aim of their overall management. Intensive management of patients with diabetes includes...... controlling blood glucose levels and blood pressure as well as blockade of the renin-angiotensin-aldosterone system; these approaches will reduce the incidence of diabetic kidney disease and slow its progression. Indeed, the major decline in the incidence of diabetic kidney disease (DKD) over the past 30...

  7. Obesity and kidney disease

    Directory of Open Access Journals (Sweden)

    Geraldo Bezerra da Silva Junior

    Full Text Available Abstract Obesity has been pointed out as an important cause of kidney diseases. Due to its close association with diabetes and hypertension, excess weight and obesity are important risk factors for chronic kidney disease (CKD. Obesity influences CKD development, among other factors, because it predisposes to diabetic nephropathy, hypertensive nephrosclerosis and focal and segmental glomerulosclerosis. Excess weight and obesity are associated with hemodynamic, structural and histological renal changes, in addition to metabolic and biochemical alterations that lead to kidney disease. Adipose tissue is dynamic and it is involved in the production of "adipokines", such as leptin, adiponectin, tumor necrosis factor-α, monocyte chemoattractant protein-1, transforming growth factor-β and angiotensin-II. A series of events is triggered by obesity, including insulin resistance, glucose intolerance, dyslipidemia, atherosclerosis and hypertension. There is evidence that obesity itself can lead to kidney disease development. Further studies are required to better understand the association between obesity and kidney disease.

  8. Preglacial surface remnants and Quaternary glacial regimes in northwestern Sweden

    Science.gov (United States)

    Kleman, Johan; Stroeven, Arjen P.

    1997-05-01

    We present a detailed map of the distribution of preglacial surface remnants in the Kebnekaise region of northwestern Sweden. In this mountain area we discern four important large-scale geomorphological units, each representing a specific set of erosional agents and formative conditions. These are: (i) intact preglacial surface remnants, characterized by gentle slopes, round summits, wide shallow valleys, and an absence of rock basins; (ii) preglacial surface remnants showing signs of minor glacial erosion and deposition; (iii) glacially scoured surfaces, including glacial troughs; (iv) deep fluvial valleys cut into the preglacial surface. The pattern of glacial erosion is explained as the result of three specific modes of glaciation known to have existed during the last 120,000 years, and inferred to have repeatedly prevailed during the last 2.75 million years: cirque glaciation, mountain ice sheets, and Fennoscandian ice sheets. A deep-ocean oxygen-isotope record of foraminifera from the North Atlantic (DSDP 607) was used to infer the temporal extent of these modes of glaciation during the last 2.75 million years. We interpret the preglacial landscape preservation and the pattern of glacial erosion in terms of the configuration, the basal thermal regime, and the duration of such glaciation events. The average subglacial thermal regime of both ice sheet types was frozen on the uplands and melting in the main valleys, where outlet glaciers and ice-streams formed. The pre-glacial landscape is best preserved at intermediate elevations, low enough not to have been covered by cirque glaciers, and apparently high enough not to have experienced melted-bed conditions and subglacial erosion during ice sheet overriding events. In a narrow high-relief zone along the elevation axis, interglacial fluvial erosion was morphologically important. The absence of glacial erosion on uplands in this zone allowed fluvial erosion to commence on the same locations during each ice

  9. A neutron star with a carbon atmosphere in the Cassiopeia A supernova remnant.

    Science.gov (United States)

    Ho, Wynn C G; Heinke, Craig O

    2009-11-05

    The surface of hot neutron stars is covered by a thin atmosphere. If there is accretion after neutron-star formation, the atmosphere could be composed of light elements (H or He); if no accretion takes place or if thermonuclear reactions occur after accretion, heavy elements (for example, Fe) are expected. Despite detailed searches, observations have been unable to confirm the atmospheric composition of isolated neutron stars. Here we report an analysis of archival observations of the compact X-ray source in the centre of the Cassiopeia A supernova remnant. We show that a carbon atmosphere neutron star (with low magnetic field) produces a good fit to the spectrum. Our emission model, in contrast with others, implies an emission size consistent with theoretical predictions for the radius of neutron stars. This result suggests that there is nuclear burning in the surface layers and also identifies the compact source as a very young ( approximately 330-year-old) neutron star.

  10. PHOSPHATE METABOLISM IN KIDNEY DONORS: A CROSS-SECTIONAL STUDY

    Directory of Open Access Journals (Sweden)

    Jayakumar Edathedathe

    2016-05-01

    Full Text Available AIM To study the changes in phosphate metabolism in kidney donors, to study the correlation of albuminuria, fractional excretion of phosphorus [FE Pi] and estimated glomerular filtration rate [eGFR] with fibroblast growth factor 23 [FGF 23] in kidney donors, to study the early tubule interstitial injury in the remnant kidney of donors by measuring urine transforming growth factor beta [TGF beta] levels. MATERIALS AND METHODS A cross-sectional study in which kidney donors with 1 year or more after donation were included. 69 kidney donors with a mean duration of 5.86 years after kidney donation were studied. Serum phosphate level, fractional excretion of phosphorus [FE Pi] and serum levels of parathyroid hormone were measured. Plasma levels of FGF 23 were measured by a second generation enzyme linked immune sorbent assay [ELISA]. Renal function was assessed by estimated glomerular filtration rate [eGFR] and degree of albuminuria. Urine levels of transforming growth factor beta [TGF beta] were measured by ELISA. A hypothesis that in kidney donors with reduced nephron number, the single nephron excretion of phosphorus will be increased to maintain normal phosphorus homeostasis and that this increase in single nephron phosphorus excretion may be mediated by FGF 23 was proposed. Testing of this hypothesis was done by studying the correlation between parameters of phosphorus metabolism, FGF 23 and the renal function of the donors. RESULTS The mean eGFR was 70.36 mL/min/1.73 m2 . 52.2% of donors had moderate increase in albuminuria [microalbuminuria], Serum phosphorus, fractional excretion of phosphorus and serum PTH levels were in the normal range. FGF 23 levels were in the normal reference range and showed no correlation with FE pi, eGFR or albuminuria, Urine TGF-beta levels were undetectable in all the donors. DISCUSSION Normal phosphorus homeostasis is maintained in kidney donors. There was no correlation between FE pi and FGF 23 levels. Kidney

  11. Prognostic model for survival in patients with metastatic renal cell carcinoma: results from the international kidney cancer working group.

    Science.gov (United States)

    Manola, Judith; Royston, Patrick; Elson, Paul; McCormack, Jennifer Bacik; Mazumdar, Madhu; Négrier, Sylvie; Escudier, Bernard; Eisen, Tim; Dutcher, Janice; Atkins, Michael; Heng, Daniel Y C; Choueiri, Toni K; Motzer, Robert; Bukowski, Ronald

    2011-08-15

    To develop a single validated model for survival in metastatic renal cell carcinoma (mRCC) using a comprehensive international database. A comprehensive database of 3,748 patients including previously reported clinical prognostic factors was established by pooling patient-level data from clinical trials. Following quality control and standardization, descriptive statistics were generated. Univariate analyses were conducted using proportional hazards models. Multivariable analysis using a log-logistic model stratified by center and multivariable fractional polynomials was conducted to identify independent predictors of survival. Missing data were handled using multiple imputation methods. Three risk groups were formed using the 25th and 75th percentiles of the resulting prognostic index. The model was validated using an independent data set of 645 patients treated with tyrosine kinase inhibitor (TKI) therapy. Median survival in the favorable, intermediate and poor risk groups was 26.9 months, 11.5 months, and 4.2 months, respectively. Factors contributing to the prognostic index included treatment, performance status, number of metastatic sites, time from diagnosis to treatment, and pretreatment hemoglobin, white blood count, lactate dehydrogenase, alkaline phosphatase, and serum calcium. The model showed good concordance when tested among patients treated with TKI therapy (C statistic = 0.741, 95% CI: 0.714-0.768). Nine clinical factors can be used to model survival in mRCC and form distinct prognostic groups. The model shows utility among patients treated in the TKI era. ©2011 AACR.

  12. Arterial Retention of Remnant Lipoproteins Ex Vivo Is Increased in Insulin Resistance Because of Increased Arterial Biglycan and Production of Cholesterol-Rich Atherogenic Particles That Can Be Improved by Ezetimibe in the JCR:LA-cp Rat

    Science.gov (United States)

    Mangat, Rabban; Warnakula, Samantha; Borthwick, Faye; Hassanali, Zahra; Uwiera, Richard R.E.; Russell, James C.; Cheeseman, Christopher I.; Vine, Donna F.; Proctor, Spencer D

    2012-01-01

    Background Literature supports the “response-to-retention” hypothesis—that during insulin resistance, impaired metabolism of remnant lipoproteins can contribute to accelerated cardiovascular disease progression. We used the JCR:LA-cp rat model of metabolic syndrome (MetS) to determine the extent of arterial accumulation of intestinal-derived remnants ex vivo and potential mechanisms that contribute to exacerbated cholesterol deposition in insulin resistance. Methods and Results Arteries from control and MetS (insulin-resistant) JCR:LA-cp rats were perfused ex vivo with Cy5-labeled remnant lipoproteins, and their arterial retention was quantified by confocal microscopy. Arterial proteoglycans were isolated from control and MetS rats at 6, 12, and 32 weeks of age. There was a significant increase in the arterial retention of remnants and in associated cholesterol accumulation in MetS rats as compared to control rats. Mechanistic studies reveal that increased cholesterol deposition is a result of greater arterial biglycan content; longer glycosaminoglycans and increased production of cholesterol-rich intestinal-derived remnants, as compared to controls. Additionally, perfusion of vessels treated with ezetimibe, alone or in combination with simvastatin, with remnants isolated from the respective treatment group reduced ex vivo arterial retention of remnant-derived cholesterol ex vivo as compared to untreated controls. Conclusions Increased progression of atherosclerotic cardiovascular disease in MetS and type 2 diabetes mellitus might be explained in part by an increase in the arterial retention of cholesterol-rich remnants. Furthermore, ezetimibe alone or in combination treatment with simvastatin could be beneficial in ameliorating atherosclerotic cardiovascular disease in insulin resistance and MetS. PMID:23316299

  13. The mass spectrum of compact remnants from the PARSEC stellar evolution tracks

    Science.gov (United States)

    Spera, Mario; Mapelli, Michela; Bressan, Alessandro

    2015-08-01

    The mass spectrum of stellar mass black holes (BHs) is highly uncertain. Dynamical mass measurements are available only for few (˜10) BHs in X-ray binaries, while theoretical models strongly depend on the hydrodynamics of supernova (SN) explosions and on the evolution of massive stars. In this paper, we present and discuss the mass spectrum of compact remnants that we obtained with SEVN, a new public population-synthesis code, which couples the PARSEC stellar evolution tracks with up-to-date recipes for SN explosion (depending on the carbon-oxygen mass of the progenitor, on the compactness of the stellar core at pre-SN stage and on a recent two-parameter criterion based on the dimensionless entropy per nucleon at pre-SN stage). SEVN can be used both as a stand-alone code and in combination with direct-summation N-body codes (STARLAB, HIGPUS). The PARSEC stellar evolution tracks currently implemented in SEVN predict significantly larger values of the carbon-oxygen core mass with respect to previous models. For most of the SN recipes we adopt, this implies substantially larger BH masses at low metallicity (≤2 × 10-3), than other population synthesis codes. The maximum BH mass found with SEVN is ˜25, 60 and 130 M⊙ at metallicity Z = 2 × 10-2, 2 × 10-3 and 2 × 10-4, respectively. Mass loss by stellar winds plays a major role in determining the mass of BHs for very massive stars (≥90 M⊙), while the remnant mass spectrum depends mostly on the adopted SN recipe for lower progenitor masses. We discuss the implications of our results for the transition between neutron star and BH mass, and for the expected number of massive BHs (with mass >25 M⊙) as a function of metallicity.

  14. Development and validation of a predictive model for Chronic Kidney Disease progression in Type 2 Diabetes Mellitus based on a 13-year study in Singapore.

    Science.gov (United States)

    Low, Serena; Lim, Su Chi; Zhang, Xiao; Zhou, Shiyi; Yeoh, Lee Ying; Liu, Yan Lun; Tavintharan, Subramaniam; Sum, Chee Fang

    2017-01-01

    This study aims to develop and validate a predictive model for Chronic Kidney Disease (CKD) progression in Type 2 Diabetes Mellitus (T2DM). We conducted a prospective study on 1582 patients with T2DM from a Diabetes Centre in regional hospital in 2002-2014. CKD progression was defined as deterioration across eGFR categories with ⩾25% drop from baseline. The dataset was randomly split into development (70%) and validation (30%) datasets. Stepwise multivariable logistic regression was used to identify baseline predictors for model development. Model performance in the two datasets was assessed. During median follow-up of 5.5years, 679 (42.9%) had CKD progression. Progression occurred in 467 (42.2%) and 212 patients (44.6%) in development and validation datasets respectively. Systolic blood pressure, HbA1c, estimated glomerular filtration rate and urinary albumin-to-creatinine ratio were associated with progression. Areas under receiving-operating-characteristics curve for the training and test datasets were 0.80 (95%CI, 0.77-0.83) and 0.83 (95%CI, 0.79-0.87). Observed and predicted probabilities by quintiles were not statistically different with Hosmer-Lemeshow χ2 0.65 (p=0.986) and 1.36 (p=0.928) in the two datasets. Sensitivity and specificity were 71.4% and 72.2% in development dataset, and 75.6% and 72.3% in the validation dataset. A model using routinely available clinical measurements can accurately predict CKD progression in T2DM. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

  15. Assessment of Future Remnant Liver Function Using Hepatobiliary Scintigraphy in Patients Undergoing Major Liver Resection

    NARCIS (Netherlands)

    de Graaf, W.; van Lienden, K.P.; Dinant, S.; Roelofs, J.J.T.H.; Busch, O.R.C.; Gouma, D.J.; Bennink, R.J.; van Gulik, T.M.

    2010-01-01

    Tc-99m-mebrofenin hepatobiliary scintigraphy (HBS) was used as a quantitative method to evaluate liver function. The aim of this study was to compare future remnant liver function assessed by Tc-99m-mebrofenin hepatobiliary scintigraphy with future remnant liver volume in the prediction of liver

  16. An X-Ray and Radio Study of the Varying Expansion Velocities in Tycho's Supernova Remnant

    Science.gov (United States)

    Williams, Brian J.; Chomiuk, Laura; Hewitt, John W.; Blondin, John M.; Borkowski, Kazimierz J.; Ghavamian, Parviz; Petre, Robert; Reynolds, Stephen P.

    2016-01-01

    We present newly obtained X-ray and radio observations of Tycho's supernova remnant using Chandra and the Karl G. Jansky Very Large Array in 2015 and 2013/14, respectively. When combined with earlier epoch observations by these instruments, we now have time baselines for expansion measurements of the remnant of 12-15 years in the X-rays and 30 years in the radio. The remnant's large angular size allows for proper motion measurements at many locations around the periphery of the blast wave. Consistent with earlier measurements, we find a clear gradient in the expansion velocity of the remnant, despite its round shape. The proper motions on the western and southwestern sides of the remnant are about a factor of two higher than those in the east and northeast. We showed in an earlier work that this is related to an offset of the explosion site from the geometric center of the remnant due to a density gradient in the ISM, and using our refined measurements reported here, we find that this offset is approximately 23? toward the northeast. An explosion center offset in such a circular remnant has implications for searches for progenitor companions in other remnants.

  17. Remnants of black rings from gravity’s rainbow

    Energy Technology Data Exchange (ETDEWEB)

    Ali, Ahmed Farag [Center for Fundamental Physics, Zewail City of Science and Technology,6th of October City, Giza 12588 (Egypt); Department of Physics, Faculty of Science, Benha University,Benha 13518 (Egypt); Faizal, Mir [Department of Physics and Astronomy, University of Waterloo,Waterloo, Ontario, N2L 3G1 (Canada); Khalil, Mohammed M. [Department of Electrical Engineering, Alexandria University,El-Horreya Rd., Alexandria 12544 (Egypt)

    2014-12-29

    In this paper, we investigate a spinning black ring and a charged black ring in the context of gravity’s rainbow. By incorporating rainbow functions proposed by Amelino-Camelia, et al. in http://dx.doi.org/10.1142/S0217751X97000566 http://dx.doi.org/10.12942/lrr-2013-5 in the metric of the black rings, a considerable modification happens to their thermodynamical properties. We calculate corrections to the temperature, entropy and heat capacity of the black rings. These calculations demonstrate that the behavior of Hawking radiation changes considerably near the Planck scale in gravity’s rainbow, where it is shown that black rings do not evaporate completely and a remnant is left as the black rings evaporate down to Planck scale.

  18. ‘The Dressmaker, remnants of a life

    DEFF Research Database (Denmark)

    Carpe Pérez, Inmaculada Concepción; Garcia Rams, Maria Susana

    The Dressmaker, remnants of a life, is a study case of our research, at the Animated Learning Lab, as a means of reflection on the re-construction of the self through animation; understanding the self as our history and story. It’s about how we see our own story; everything starts with perception...... (Beau Lotto, 2013). Currently it’s not very common to conceive animation as a communication media of biographies. Nevertheless, features as Drawn from Memory (1995, Paul Fierlinger), Waltz with Bashir (2008, Ari Folman), It’s Such a Beautiful Day (2012, Don Hertzfeldt), Wrinkles (2012, Ignacio Ferreras......) o Rocks in my Pockets (2014, Signe Baumane), are clear samples of the treatment of the autobiographic memory and documentary through animation techniques. When we produce an animated film, we can appreciate how the creation of characters and scenarios are transformed into visual metaphors, making...

  19. Statistical Analysis of Supernova Remnants in the Large Magellanic Cloud

    Science.gov (United States)

    Bozzetto, Luke M.; Filipović, Miroslav D.; Vukotić, Branislav; Pavlović, Marko Z.; Urošević, Dejan; Kavanagh, Patrick J.; Arbutina, Bojan; Maggi, Pierre; Sasaki, Manami; Haberl, Frank; Crawford, Evan J.; Roper, Quentin; Grieve, Kevin; Points, S. D.

    2017-05-01

    We construct the most complete sample of supernova remnants (SNRs) in any galaxy—the Large Magellanic Cloud (LMC) SNR sample. We study their various properties such as spectral index (α), size, and surface brightness. We suggest an association between the spatial distribution and environment density of LMC SNRs, and their tendency to be located around supergiant shells. We find evidence that the 16 known type Ia LMC SNRs are expanding in a lower density environment compared to the Core-Collapse (CC) type. The mean diameter of our entire population (74) is 41 pc, which is comparable to nearby galaxies. We did not find any correlation between the type of SN explosion, ovality, or age. The N(residency time of electrons in the galaxy (4.0-14.3 Myr), implying that SNRs should be the dominant mechanism for the production and acceleration of CRs.

  20. Exploration of Galactic γ-ray supernova remnants

    Science.gov (United States)

    Tian, WenWu; Zhang, JianLi

    2013-08-01

    New generational very-high-energy telescope arrays have been detecting more than 120 TeV γ-ray sources. Multi-wavelength observations on these γ-ray sources have proven to be robust in shedding light on their nature. The coming radio telescope arrays like ASKAP and FAST may find more faint (extended) radio sources due to their better sensitivities and resolutions, might identify more previously un-identified γ-ray sources and set many new targets for future deep surveys by very-high-energy ground-based telescopes like LHAASO. We in the paper summarize a list of known Galactic γ-ray Supernova Remnants (SNRs) with or without radio emissions so far, which includes some SNRs deserving top priority for future multi-wave-length observations.

  1. Historical Supernova Explosions in Our Galaxy and Their Remnants

    Science.gov (United States)

    Green, David A.

    Supernova explosions mark the end points of stellar evolution, releasing large amounts of material and energy into the interstellar medium. In our Galaxy the expected rate of supernovae is about 1 in every 50 years or so, although it is only the relatively nearby ones that are expected to be visible optically, due to obscuration. Over the last two thousand years or so there are historical records of nine Galactic supernovae. The majority of these records are from East Asia (i.e. China, Japan and Korea), although the most recent historical supernovae have European records, and there are a variety of Arabic records also available for some events. Here I review these records of the historical supernovae, and the modern observations of the supernova remnants that they have produced.

  2. The first few months of a supernova remnant

    Science.gov (United States)

    Gabler, M.; Janka, H.-T.; Wongwathanara, A.

    2016-06-01

    We perform long-term, hydrodynamical simulations of supernova remnants in 3 dimensions. Continuing the simulations of A.Wongwathanarat "3D long-time CCSN simulations: from shock revival to shock break-out" we follow the evolution of the shock and the ejecta during the first few months after the explosion. The explosion is simulated with a ray-by-ray gray neutrino transport approximation and the so called Yin-Yang grid (an axis-free spherical polar coordinates grid). For the late phases we investigate here, the neutrino transport is no longer needed. We study the rising bubbles of the ejecta and follow how their morphology changes due to acceleration at the stellar surface. We further include the energy input caused by the decay of nickel and can identify the first traces of the influence of this radioactive heating. The bubbles, which otherwise would expand homologously, start to inflate due to the additional energy source of the nickel decay.

  3. Exploring properties of high-density matter through remnants of neutron-star mergers

    Energy Technology Data Exchange (ETDEWEB)

    Bauswein, Andreas [Aristotle University of Thessaloniki, Department of Physics, Thessaloniki (Greece); Heidelberger Institut fuer Theoretische Studien, Heidelberg (Germany); Stergioulas, Nikolaos [Aristotle University of Thessaloniki, Department of Physics, Thessaloniki (Greece); Janka, Hans-Thomas [Max-Planck-Institut fuer Astrophysik, Garching (Germany)

    2016-03-15

    Remnants of neutron-star mergers are essentially massive, hot, differentially rotating neutron stars, which are initially strongly oscillating. As such they represent a unique probe for high-density matter because the oscillations are detectable via gravitational-wave measurements and are strongly dependent on the equation of state. The impact of the equation of state for instance is apparent in the frequency of the dominant oscillation mode of the remnant. For a fixed total binary mass a tight relation between the dominant postmerger oscillation frequency and the radii of nonrotating neutron stars exists. Inferring observationally the dominant postmerger frequency thus determines neutron star radii with high accuracy of the order of a few hundred meters. By considering symmetric and asymmetric binaries of the same chirp mass, we show that the knowledge of the binary mass ratio is not critical for this kind of radius measurements. We perform simulations which show that initial intrinsic neutron star rotation is unlikely to affect this method of constraining the high-density equation of state. We also summarize different possibilities about how the postmerger gravitational-wave emission can be employed to deduce the maximum mass of nonrotating neutron stars. We clarify the nature of the three most prominent features of the postmerger gravitational-wave spectrum and argue that the merger remnant can be considered to be a single, isolated, self-gravitating object that can be described by concepts of asteroseismology. We sketch how the consideration of the strength of secondary gravitational-wave peaks leads to a classification scheme of the gravitational-wave emission and postmerger dynamics. The understanding of the different mechanisms shaping the gravitational-wave signal yields a physically motivated analytic model of the gravitational-wave emission, which may form the basis for template-based gravitational-wave data analysis. We explore the observational

  4. The fate of supernova remnants near quiescent supermassive black holes

    Science.gov (United States)

    Rimoldi, A.; Rossi, E. M.; Piran, T.; Portegies Zwart, S.

    2015-03-01

    There is mounting observational evidence that most galactic nuclei host both supermassive black holes (SMBHs) and young populations of stars. With an abundance of massive stars, core-collapse supernovae are expected in SMBH spheres of influence. We develop a novel numerical method, based on the Kompaneets approximation, to trace supernova remnant (SNR) evolution in these hostile environments, where radial gas gradients and SMBH tides are present. We trace the adiabatic evolution of the SNR shock until 50 per cent of the remnant is either in the radiative phase or is slowed down below the SMBH Keplerian velocity and is sheared apart. In this way, we obtain shapes and lifetimes of SNRs as a function of the explosion distance from the SMBH, the gas density profile and the SMBH mass. As an application, we focus here exclusively on quiescent SMBHs, because their light may not hamper detections of SNRs and because we can take advantage of the unsurpassed detailed observations of our Galactic Centre. Assuming that properties such as gas and stellar content scale appropriately with the SMBH mass, we study SNR evolution around other quiescent SMBHs. We find that, for SMBH masses over ˜107 M⊙, tidal disruption of SNRs can occur at less than 104 yr, leading to a shortened X-ray emitting adiabatic phase, and to no radiative phase. On the other hand, only modest disruption is expected in our Galactic Centre for SNRs in their X-ray stage. This is in accordance with estimates of the lifetime of the Sgr A East SNR, which leads us to expect one supernova per 104 yr in the sphere of influence of Sgr A*.

  5. Cannabinoid receptors in the kidney.

    Science.gov (United States)

    Hryciw, Deanne H; McAinch, Andrew J

    2016-09-01

    The endocannabinoid system modulates cell signaling targets that are essential for energy homeostasis. Endocannabinoids bind to G protein-coupled receptors in the central nervous system and periphery, including the kidney. Modulation of cannabinoid receptor 1 (CB1) and CB2 activity in the kidney in diabetes and obesity has been identified as potential therapeutic target to reduce albuminuria and renal fibrosis. This review will highlight the results of recent studies that have identified a role for CB1 and CB2 in normal and pathological renal conditions. CB1 and CB2 have been reported to play key roles in renal function and dysfunction. Recent studies have determined that antagonism of CB1 and agonism of CB2 in diabetic nephropathy and obesity associated kidney disease can reduce albuminuria, potentially by acting on both the glomeruli and tubules. Emerging studies have also identified a role for CB1 in renal diseases associated with fibrosis, with CB1 upregulated in multiple models of human nephropathies. Emerging studies using isolated cells, rodent models, and human studies have identified a critical role for the endocannabinoid system in renal function and disease. Thus, therapeutics that modulate the activity of CB1 and CB2 in renal disease could become clinically relevant.

  6. Biomarkers of Exposure to Toxic Substances. Volume 5: Biomarker Pre-validation Studies Prevalidation of Urine and Serum Biomarkers Indicative of Subclinical Kidney Damage in a Nephrotoxin Model

    Science.gov (United States)

    2009-05-01

    component complex prevents its filtration from the kidney. However, once retinol is released, the apoRBP4 is quickly filtered out the kidney...bladder cancer (Malmström et al., 1993) and as a plasma biomarker for preeclampsia (Yasumizu et al., 1996) although a thorough interrogation as to its...332, 6163, Mar 1988 pp. 411-415. Yasumizu T, and Kato J, “Clinical evaluation of plasma fibronectin level as a biomarker of preeclampsia ,” The

  7. Aberrant Smad3 phosphoisoforms in cyst-lining epithelial cells in the cpk mouse, a model of autosomal recessive polycystic kidney disease.

    Science.gov (United States)

    Hama, Taketsugu; Nakanishi, Koichi; Sato, Masashi; Mukaiyama, Hironobu; Togawa, Hiroko; Shima, Yuko; Miyajima, Masayasu; Nozu, Kandai; Nagao, Shizuko; Takahashi, Hisahide; Sako, Mayumi; Iijima, Kazumoto; Yoshikawa, Norishige; Suzuki, Hiroyuki

    2017-12-01

    Cystic epithelia acquire mesenchymal-like features in polycystic kidney disease (PKD). In this phenotypic alteration, it is well known that transforming growth factor (TGF)-β/Smad3 signaling is involved; however, there is emerging new data on Smad3 phosphoisoforms: Smad3 phosphorylated at linker regions (pSmad3L), COOH-terminal regions (pSmad3C), and both (pSmad3L/C). pSmad3L/C has a pathological role in colorectal cancer. Mesenchymal phenotype-specific cell responses in the TGF-β/Smad3 pathway are implicated in carcinomas. In this study, we confirmed mesenchymal features and examined Smad3 phosphoisoforms in the cpk mouse, a model of autosomal recessive PKD. Kidney sections were stained with antibodies against mesenchymal markers and domain-specific phospho-Smad3. TGF-β, pSmad3L, pSmad3C, JNK, cyclin-dependent kinase (CDK) 4, and c-Myc were evaluated by Western blotting. Cophosphorylation of pSmad3L/C was assessed by immunoprecipitation. α-Smooth muscle actin, which indicates mesenchymal features, was expressed higher in cpk mice. pSmad3L expression was increased in cpk mice and was predominantly localized in the nuclei of tubular epithelial cells in cysts; however, pSmad3C was equally expressed in both cpk and control mice. Levels of pSmad3L, JNK, CDK4, and c-Myc protein in nuclei were significantly higher in cpk mice than in controls. Immunoprecipitation showed that Smad3 was cophosphorylated (pSmad3L/C) in cpk mice. Smad3 knockout/cpk double-mutant mice revealed amelioration of cpk abnormalities. These findings suggest that upregulating c-Myc through the JNK/CDK4-dependent pSmad3L pathway may be key to the pathophysiology in cpk mice. In conclusion, a qualitative rather than a quantitative abnormality of the TGF-β/Smad3 pathway is involved in PKD and may be a target for disease-specific intervention. Copyright © 2017 the American Physiological Society.

  8. A new method of modelling early plasma creatinine changes predicts 1-year graft function after kidney transplantation

    DEFF Research Database (Denmark)

    Krogstrup, Nicoline V; Bibby, Bo Martin; Aulbjerg, Camilla

    2016-01-01

    modelled for each patient using an exponential, logistic, or linear model, and the time to a 50% decrease in p-cr (tCr50) was estimated. RESULTS: Linear regression analysis showed a negative correlation between tCr50 and eGFR 1 year post-transplant (n = 96, r = -0.369, β = -0.112, p = 0.......0002). The correlation was maintained when corrected for the relevant recipient and donor characteristics. tCr50 correlated positively with the number of hospitalisation days, the number of graft ultrasound examinations, and the number of biopsies. CONCLUSIONS: A modelled time to a 50% decrease in p-cr predicts 1-year...

  9. Is Remnant Preservation Truly Beneficial to Anterior Cruciate Ligament Reconstruction Healing? Clinical and Magnetic Resonance Imaging Evaluations of Remnant-Preserved Reconstruction.

    Science.gov (United States)

    Naraoka, Takuya; Kimura, Yuka; Tsuda, Eiichi; Yamamoto, Yuji; Ishibashi, Yasuyuki

    2017-04-01

    Remnant-preserved anterior cruciate ligament (ACL) reconstruction was introduced to improve clinical outcomes and biological healing. However, the effects of remnant preservation and the influence of the delay from injury until reconstruction on the outcomes of this technique are still uncertain. Purpose/Hypothesis: The purposes of this study were to evaluate whether remnant preservation improved the clinical outcomes and graft incorporation of ACL reconstruction and to examine the influence of the delay between ACL injury and reconstruction on the usefulness of remnant preservation. We hypothesized that remnant preservation improves clinical results and accelerates graft incorporation and that its effect is dependent on the delay between ACL injury and reconstruction. Cohort study; Level of evidence, 2. A total of 151 consecutive patients who underwent double-bundle ACL reconstruction using a semitendinosus graft were enrolled in this study: 74 knees underwent ACL reconstruction without a remnant (or the remnant was reconstruction with remnant preservation (RP group). These were divided into 4 subgroups based on the time from injury to surgery: phase 1 was 20 weeks (n = 25). Clinical measurements, including KT-1000 arthrometer side-to-side anterior tibial translation measurements, were assessed at 3, 6, 12, and 24 months after reconstruction. Magnetic resonance imaging evaluations of graft maturation and graft-tunnel integration of the anteromedial and posterolateral bundles were assessed at 3, 6, and 12 months after reconstruction. There was no difference in side-to-side anterior tibial translation between the NR and RP groups. There was also no difference in graft maturation between the 2 groups. Furthermore, the time from ACL injury until reconstruction did not affect graft maturation, except in the case of very long delays before reconstruction (phase 4). Graft-tunnel integration was significantly increased in both groups in a time-dependent manner. However

  10. Shape-aided kidney extraction in MR urography.

    Science.gov (United States)

    Tang, Yang; Jackson, Hollie; Lee, Susan; Nelson, Marvin; Moats, Rex A

    2009-01-01

    MR Urography (MRU) plays an important role in pediatric renal diagnoses. While accurate measurement of the kidney is essential for each imaging study, it is challenging to extract the kidney from its background. In this paper, we propose a co-focus elliptical kidney model (CEKM) to integrate the shape prior and build a novel extraction method with both regional and edge information. With a similarity metric defined between a binary mask and CEKM, a kidney template can be obtained using optimization technique. Then, a shape term derived from a distance and orientation description is designed to modify an active contour model. The distance map is used to control the contours in terms of CEKM and orientation map is designed to reduce the artifacts resulting from fake edges. The final kidney was determined with iterative solution. With the priori shape description in a parametric space, the new method can precisely extract the kidney without training, and supply promising results as the experiments demonstrated.

  11. Freely Expanding Knots of X-Ray-emitting Ejecta in Kepler’s Supernova Remnant

    Science.gov (United States)

    Sato, Toshiki; Hughes, John P.

    2017-08-01

    We report measurements of proper motion, radial velocity, and elemental composition for 14 compact X-ray-bright knots in Kepler’s supernova remnant (SNR) using archival Chandra data. The knots with the highest speed show both large proper motions (μ ˜ 0.″11-0.″14 yr-1) and high radial velocities (v ˜ 8700-10,020 km s-1). For these knots the estimated space velocities (9100 km s-1 ≲ v 3D ≲ 10,400 km s-1) are similar to the typical Si velocity seen in supernovae (SNe) Ia near maximum light. High-speed ejecta knots appear only in specific locations and are morphologically and kinematically distinct from the rest of the ejecta. The proper motions of five knots extrapolate back over the age of Kepler’s SNR to a consistent central position. This new kinematic center agrees well with previous determinations, but is less subject to systematic errors and denotes a location about which several prominent structures in the remnant display a high degree of symmetry. These five knots are expanding at close to the free expansion rate (expansion indices of 0.75 ≲ m ≲ 1.0), which we argue indicates either that they were formed in the explosion with a high density contrast (more than 100 times the ambient density) or that they have propagated through regions of relatively low density (n H white dwarf for models of SNe Ia. Other knots show lower speeds and expansion indices consistent with decelerated ejecta knots or features in the ambient medium overrun by the forward shock. Our new accurate location for the explosion site has well-defined positional uncertainties, allowing for a great reduction in the area to be searched for faint surviving donor stars under non-traditional single-degenerate SNe Ia scenarios; because of the lack of bright stars in the search area the traditional scenario remains ruled out.

  12. Counting black holes: The cosmic stellar remnant population and implications for LIGO

    Science.gov (United States)

    Elbert, Oliver D.; Bullock, James S.; Kaplinghat, Manoj

    2018-01-01

    We present an empirical approach for interpreting gravitational wave signals of binary black hole mergers under the assumption that the underlying black hole population is sourced by remnants of stellar evolution. Using the observed relationship between galaxy mass and stellar metallicity, we predict the black hole count as a function of galaxy stellar mass. We show, for example, that a galaxy like the Milky Way should host millions of ∼30 M⊙ black holes and dwarf satellite galaxies like Draco should host ∼100 such remnants, with weak dependence on the assumed initial mass function and stellar evolution model. Most low-mass black holes (∼10 M⊙) typically reside within massive galaxies (M⋆ ≃ 1011 M⊙) while massive black holes (∼50 M⊙) typically reside within dwarf galaxies (M⋆ ≃ 109 M⊙) today. If roughly 1 per cent of black holes are involved in a binary black hole merger, then the reported merger rate densities from advanced Laser Interferometer Gravitational-Wave Observatory can be accommodated for a range of merger time-scales, and the detection of mergers with >50 M⊙ black holes should be expected within the next decade. Identifying the host galaxy population of the mergers provides a way to constrain both the binary neutron star or black hole formation efficiencies and the merger time-scale distributions; these events would be primarily localized in dwarf galaxies if the merger time-scale is short compared to the age of the Universe and in massive galaxies otherwise. As more mergers are detected, the prospect of identifying the host galaxy population, either directly through the detection of electromagnetic counterparts of binary neutron star mergers or indirectly through the anisotropy of the events, will become a realistic possibility.

  13. Transport of organic anions and cations in murine embryonic kidney development and in serially-reaggregated engineered kidneys.

    Science.gov (United States)

    Lawrence, Melanie L; Chang, C-Hong; Davies, Jamie A

    2015-03-13

    Recent advances in renal tissue engineering have shown that dissociated, early renogenic tissue from the developing embryo can self-assemble into morphologically accurate kidney-like organs arranged around a central collecting duct tree. In order for such self-assembled kidneys to be useful therapeutically or as models for drug screening, it is necessary to demonstrate that they are functional. One of the main functional characteristics of mature kidneys is transport of organic anions and cations into and out of the proximal tubule. Here, we show that the transport function of embryonic kidneys allowed to develop in culture follows a developmental time-course that is comparable to embryonic kidney development in vivo. We also demonstrate that serially-reaggregated engineered kidneys can transport organic anions and cations through specific uptake and efflux channels. These results support the physiological relevance of kidneys grown in culture, a commonly used model for kidney development and research, and suggest that serially-reaggregated kidneys self-assembled from separated cells have some functional characteristics of intact kidneys.

  14. [Hereditary kidney diseases in children].

    Science.gov (United States)

    Zhang, Yan-qin; Ding, Jie; Wang, Fang; Zhang, Hong-wen

    2013-04-18

    About 10 to 15 percent of kidney diseases are inherited or related to genetic factors. While, hereditary kidney diseases have no specific clinical manifestations and react poorly to the therapy, as a result, about 30 percent of hospitalized children with chronic renal failure is due to hereditary kidney diseases in our country. Hereditary kidney diseases are related to many genes. Molecular genetic analysis plays an important role in the diagnosis and prenatal diagnosis of hereditary kidney diseases. Our group have made a series of research in hereditary kidney diseases for nearly 30 years. Here we review the research work and the main results in hereditary kidney diseases of our group.

  15. Kidney Stones (For Parents)

    Science.gov (United States)

    ... and lifestyle. Drinking lots of sugary, caffeinated , or sports drinks and eating a diet high in sodium (salt) ... in their diet limit consumption of soda/soft/sports drinks If dietary changes fail to prevent kidney stones, ...

  16. Organ Facts: Kidney / Pancreas

    Science.gov (United States)

    ... Your Child Adjust Camps Resources LIVING DONATION Facts Types Being a Living Donor About the Operation Financing Living Donation Home / Before The Transplant / Organ Facts / Kidney/Pancreas Organ Facts Heart Lung Heart/ ...

  17. Acute Kidney Failure

    Science.gov (United States)

    ... breath Acute kidney failure Symptoms & causes Diagnosis & treatment Advertisement Mayo Clinic does not endorse companies or products. ... a Job Site Map About This Site Twitter Facebook Google YouTube Pinterest Mayo Clinic is a not- ...

  18. Chronic kidney disease

    African Journals Online (AJOL)

    especially in ... medical professionals and nursing practitioners to identify risk factors of CKD, making early diagnoses and ... public as well as doctor and nurse practitioners is required nationally. The rewards for both SA kidney disease sufferers and ...

  19. Acquired Cystic Kidney Disease

    Science.gov (United States)

    ... Diabetes Inspidus Glomerular Diseases Goodpasture Syndrome Henoch-Schönlein Purpura IgA Nephropathy Kidney Disease in Children Childhood Nephrotic ... will treat infections with antibiotics—medications that kill bacteria. If large cysts are causing pain, a health ...

  20. Kidney transplant - slideshow

    Science.gov (United States)

    ... ency/presentations/100087.htm Kidney transplant - series—No