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Sample records for juxtamedullary nephron technique

  1. Do similar factors control the glomerular filtration rate of superficial and juxtamedullary nephrons

    International Nuclear Information System (INIS)

    Rouffignac, C. de

    1975-01-01

    The SNGFR intrarenal distribution was studied under conditions where the whole kidney GFR remains unchanged and then where it is altered as compared to the normal non diuretic state. Only data obtained from experiments in which the SNGFR of both superficial and juxtamedullary nephrons were measured with the same techniques were reported. The superficial over juxtamedullary SNGFR ratio appears to be relatively stable and independent of physiological conditions. Nevertheless, in cases which indicate changes in the SNGFR intrarenal distribution, these changes remain always of limited magnitude. Thus it seems possible to conclude, that the SNGFR is controlled by factors that act, at least qualitatively, in the same manner in the whole nephron population [fr

  2. Autoregulation and tubuloglomerular feedback in juxtamedullary glomerular arterioles.

    Science.gov (United States)

    Casellas, D; Moore, L C

    1990-03-01

    Videometric measurements of changes in vessel lumen diameters were made to investigate autoregulatory and tubuloglomerular feedback (TGF) responses of early efferent arterioles (EA), mid-to-late afferent arterioles (MAA), and terminal, juxtaglomerular afferent arterioles (JAA) in rat juxtamedullary nephrons in vitro. High-contrast shadow-cast images of blood-perfused arterioles at the glomerular vascular pole were obtained with incident illumination and long-working-distance objectives fitted to a compound microscope. In response to an increase in blood perfusion pressure from 60 to 140 mmHg, strong autoregulatory vasoconstriction was observed in the MAA and JAA, with respective reductions in mean luminal diameter of 23 +/- 4 and 40 +/- 4% (mean +/- SE); EA diameter was unchanged. In response to TGF excitation by direct microinjection of Ringer solution into the cortical thick ascending limb segment near the macula densa, JAA luminal diameter decreased by 34 +/- 5%. The TGF responses were completely inhibited by the addition of 0.1 mM furosemide to the tubular injectate. Calcium channel blockade achieved by adding 1 microM nimodipine to the superfusate had no effect on early EA diameter but produced a blood pressure-dependent JAA and MAA vasodilation and complete inhibition of autoregulatory responses. These results provide direct evidence that the distal afferent arteriole in juxtamedullary nephrons is a major effector site for both renal autoregulation and tubuloglomerular feedback.

  3. A computational model for simulating solute transport and oxygen consumption along the nephrons

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    Vallon, Volker; Edwards, Aurélie

    2016-01-01

    The goal of this study was to investigate water and solute transport, with a focus on sodium transport (TNa) and metabolism along individual nephron segments under differing physiological and pathophysiological conditions. To accomplish this goal, we developed a computational model of solute transport and oxygen consumption (QO2) along different nephron populations of a rat kidney. The model represents detailed epithelial and paracellular transport processes along both the superficial and juxtamedullary nephrons, with the loop of Henle of each model nephron extending to differing depths of the inner medulla. We used the model to assess how changes in TNa may alter QO2 in different nephron segments and how shifting the TNa sites alters overall kidney QO2. Under baseline conditions, the model predicted a whole kidney TNa/QO2, which denotes the number of moles of Na+ reabsorbed per moles of O2 consumed, of ∼15, with TNa efficiency predicted to be significantly greater in cortical nephron segments than in medullary segments. The TNa/QO2 ratio was generally similar among the superficial and juxtamedullary nephron segments, except for the proximal tubule, where TNa/QO2 was ∼20% higher in superficial nephrons, due to the larger luminal flow along the juxtamedullary proximal tubules and the resulting higher, flow-induced transcellular transport. Moreover, the model predicted that an increase in single-nephron glomerular filtration rate does not significantly affect TNa/QO2 in the proximal tubules but generally increases TNa/QO2 along downstream segments. The latter result can be attributed to the generally higher luminal [Na+], which raises paracellular TNa. Consequently, vulnerable medullary segments, such as the S3 segment and medullary thick ascending limb, may be relatively protected from flow-induced increases in QO2 under pathophysiological conditions. PMID:27707705

  4. Innervation of the thick ascending limb of Henle

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    Barajas, L.; Powers, K.V.

    1988-01-01

    The overlap of accumulations of autoradiographic grains (AAGs) on profiles of the thick ascending limb of Henle (TALH) was measured in autoradiograms of sections from rat kidneys with monoaminergic nerves labeled by means of tritiated norepinephrine. The amount of AAG overlap was used as an indirect means of quantifying innervation along the TALHs of superficial, mid-cortical, and juxtamedullary nephrons. The density of innervation along the TALH showed nephron heterogeneity; the juxtamedullary nephrons with a high pre- and postjuxtaglomerular apparatus (JGA) TALH density of innervation and the upper and midcortical nephrons with high TALH innervation densities at the level of the JGA. The pre-JGA TALH of the juxtamedullary nephrons had a significantly higher (P less than 0.001) density of innervation than the midcortical or superficial nephrons. The TALHs of juxtamedullary nephrons were found to have substantially more innervation than the TALHs of the other nephrons. For all three populations of nephrons, the pre-JGA TALH had the greatest amount of innervation. Neural regulation of TALH function would occur mainly along the pre-JGA and level of the JGA TALH. This regulation would increase TALH NaCl reabsorption (decrease luminal NaCl concentration) and therefore influence 1) the urinary concentrating mechanism, and 2) renin secretion via the macula densa mechanism. The innervation of the TALH was predominantly associated with the vasculature of the TALH's own nephron. However, innervation associated with medullary ray capillary beds from deeper nephrons was observed on pre-JGA TALHs from superficial and midcortical nephrons

  5. Innervation of the thick ascending limb of Henle

    Energy Technology Data Exchange (ETDEWEB)

    Barajas, L.; Powers, K.V.

    1988-08-01

    The overlap of accumulations of autoradiographic grains (AAGs) on profiles of the thick ascending limb of Henle (TALH) was measured in autoradiograms of sections from rat kidneys with monoaminergic nerves labeled by means of tritiated norepinephrine. The amount of AAG overlap was used as an indirect means of quantifying innervation along the TALHs of superficial, mid-cortical, and juxtamedullary nephrons. The density of innervation along the TALH showed nephron heterogeneity; the juxtamedullary nephrons with a high pre- and postjuxtaglomerular apparatus (JGA) TALH density of innervation and the upper and midcortical nephrons with high TALH innervation densities at the level of the JGA. The pre-JGA TALH of the juxtamedullary nephrons had a significantly higher (P less than 0.001) density of innervation than the midcortical or superficial nephrons. The TALHs of juxtamedullary nephrons were found to have substantially more innervation than the TALHs of the other nephrons. For all three populations of nephrons, the pre-JGA TALH had the greatest amount of innervation. Neural regulation of TALH function would occur mainly along the pre-JGA and level of the JGA TALH. This regulation would increase TALH NaCl reabsorption (decrease luminal NaCl concentration) and therefore influence 1) the urinary concentrating mechanism, and 2) renin secretion via the macula densa mechanism. The innervation of the TALH was predominantly associated with the vasculature of the TALH's own nephron. However, innervation associated with medullary ray capillary beds from deeper nephrons was observed on pre-JGA TALHs from superficial and midcortical nephrons.

  6. Dynamics of TGF-initiated nephron-nephron interactions in normotensive rats and SHR

    DEFF Research Database (Denmark)

    Yip, K P; Holstein-Rathlou, N H; Marsh, D J

    1992-01-01

    furosemide perfusion diminished the oscillation in both the perfused and the coupled nephron; total autospectral power in each of the nephrons and cross-spectral power were reduced to 45% of control. The correlation between noncoupled nephrons was not significant, and intratubular furosemide perfused in one...... nephron had no effect on adjacent but noncoupled nephrons. In SHR, the correlation coefficient of tubular pressure records was high from coupled nephrons only; furosemide diminished the autospectral power of pressure fluctuations to approximately 60-75% of control in both perfused and coupled nephrons...

  7. Magnitude of TGF-initiated nephron-nephron interactions is increased in SHR

    DEFF Research Database (Denmark)

    Chen, Y M; Yip, K P; Marsh, D J

    1995-01-01

    We compared the tubuloglomerular feedback (TGF)-initiated nephron-nephron interaction in spontaneously hypertensive rats (SHR) and normotensive Sprague-Dawley (SD) rats. Interaction strength was assessed by measuring stop-flow pressure (delta SFP) responses in pairs of nephrons, where only one ne...

  8. Changes of the glomerular size during the human fetal kidney development

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    Daković-Bjelaković Marija

    2006-01-01

    Full Text Available Introduction. Newborns adaptation on postnatal conditions includes significant morphological and functional renal changes. Every kidney contains a constant number of nephrons, at the end of the nephrogenesis period, which extends from week 8 to 34 of gestation. Mature juxtamedullary nephrons possess higher filtration capacity than primitive superficial nephrons, which have insufficient vascularization. Objective. The objective of the study was to calculate an average glomerular diameter in cortical zones of the kidney during development, to define periods of their most intensive growth, and to record differences of glomerular size between different cortical zones. METHOD A total of 30 human fetal kidneys aged from IV to X lunar months were analyzed. Stereological methods were used for calculating the average glomerular diameter in superficial, intermediate and juxtamedullary zone of the kidney cortex. Results. Glomeruli in the superficial cortical zone had the lowest average diameter. The average glomerular diameter continually increased from IV lunar month (0.057±0.004 mm to X lunar month (0.082±0.004 mm, with highly significant correlation with gestational age (r=0.755; p<0.01. The average glomerular diameter in the intermediate zone increased from 0.081±0.004 mm (IV lunar month to 0.096±0.004 mm (X lunar month with low linear correlation with gestational age (r=0.161. Juxtamedullary glomeruli were the biggest ones. Their average diameter, during the IV LM ranged from 0.093±0.006 mm to 0.101±0.004 mm. In the newborns (X lunar month, juxtamedullary glomeruli had spherical structures with an average diameter of 0.103±0.004 mm, and low negative correlation (r=-0.032 with gestational age. In the IV and V lunar months of gestation, there was significant difference (p<0.01; p<0.05 between the average glomerular diameter in the different zones of the kidney cortex. Conclusion. Superficial glomeruli had the smallest diameter, while

  9. Synchronization Phenomena in Nephron-Nephron Interaction

    DEFF Research Database (Denmark)

    Holstein-Rathlou, N.-H.; Yip, K.-P.; Sosnovtseva, Olga

    2001-01-01

    Experimental data for tubular pressure oscillations in rat kidneys are analyzed in order to examine the different types of synchronization that can arise between neighboring functional units. For rats with normal blood pressure, the individual unit (the nephron) typically exhibits regular oscilla...

  10. Low Nephron Number and Its Clinical Consequences

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    Valerie A. Luyckx

    2011-10-01

    Full Text Available decades ago, that developmental programming of the kidney impacts an individual’s risk for hypertension and renal disease in later life. Low birth weight is the strongest current clinical surrogate marker for an adverse intrauterine environment and, based on animal and human studies, is associated with a low nephron number. Other clinical correlates of low nephron number include female gender, short adult stature, small kidney size, and prematurity. Low nephron number in Caucasian and Australian Aboriginal subjects has been shown to be associated with higher blood pressures, and, conversely, hypertension is less prevalent in individuals with higher nephron numbers. In addition to nephron number, other programmed factors associated with the increased risk of hypertension include salt sensitivity, altered expression of renal sodium transporters, altered vascular reactivity, and sympathetic nervous system overactivity. Glomerular volume is universally found to vary inversely with nephron number, suggesting a degree of compensatory hypertrophy and hyperfunction in the setting of a low nephron number. This adaptation may become overwhelmed in the setting of superimposed renal insults, e.g. diabetes mellitus or rapid catch-up growth, leading to the vicious cycle of on-going hyperfiltration, proteinuria, nephron loss and progressive renal functional decline. Many millions of babies are born with low birth weight every year, and hypertension and renal disease prevalences are increasing around the globe. At present, little can be done clinically to augment nephron number; therefore adequate prenatal care and careful postnatal nutrition are crucial to optimize an individual’s nephron number during development and potentially to stem the tide of the growing cardiovascular and renal disease epidemics worldwide.

  11. Current Status of Nephron-Sparing Surgery (NSS) in the Management of Renal Tumours.

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    Venkatramani, Vivek; Swain, Sanjaya; Satyanarayana, Ramgopal; Parekh, Dipen J

    2017-06-01

    Nephron-sparing surgery has emerged as the surgical treatment of choice for small renal masses over the past two decades, replacing the traditional teaching of radical nephrectomy for renal cell carcinoma. With time, there has been an evolution in the techniques and indications for partial nephrectomy. This review summarizes the current status of nephron-sparing surgery for renal carcinoma and also deals with the future of this procedure.

  12. Modelling Nephron Autoregulation and Synchronization in Coupled Nephron Systems

    DEFF Research Database (Denmark)

    Laugesen, Jakob Lund

    between oscillating period-doubling systems is the topic of the larger part of the study. Since synchronization is a fundamental phenomenon in all sciences, it is treated from a general viewpoint by analyzing one of the most simple dynamical systems, the R¨ossler system, both in an externally forced...... version and in the form of two mutually coupled oscillators. The bifurcational mechanism to resonant dynamics and chaotic phase synchronization is described in detail. The transition from synchronized to non-synchronized dynamics is known to take place at a dense set of saddlenode bifurcations that run...... to exist in an externally forced nephron model and in a model of two vascular coupled nephrons, underlining that the discussed phenomena are of a common nature to forced and coupled period-doubling systems....

  13. Collective cell migration drives morphogenesis of the kidney nephron.

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    Aleksandr Vasilyev

    2009-01-01

    Full Text Available Tissue organization in epithelial organs is achieved during development by the combined processes of cell differentiation and morphogenetic cell movements. In the kidney, the nephron is the functional organ unit. Each nephron is an epithelial tubule that is subdivided into discrete segments with specific transport functions. Little is known about how nephron segments are defined or how segments acquire their distinctive morphology and cell shape. Using live, in vivo cell imaging of the forming zebrafish pronephric nephron, we found that the migration of fully differentiated epithelial cells accounts for both the final position of nephron segment boundaries and the characteristic convolution of the proximal tubule. Pronephric cells maintain adherens junctions and polarized apical brush border membranes while they migrate collectively. Individual tubule cells exhibit basal membrane protrusions in the direction of movement and appear to establish transient, phosphorylated Focal Adhesion Kinase-positive adhesions to the basement membrane. Cell migration continued in the presence of camptothecin, indicating that cell division does not drive migration. Lengthening of the nephron was, however, accompanied by an increase in tubule cell number, specifically in the most distal, ret1-positive nephron segment. The initiation of cell migration coincided with the onset of fluid flow in the pronephros. Complete blockade of pronephric fluid flow prevented cell migration and proximal nephron convolution. Selective blockade of proximal, filtration-driven fluid flow shifted the position of tubule convolution distally and revealed a role for cilia-driven fluid flow in persistent migration of distal nephron cells. We conclude that nephron morphogenesis is driven by fluid flow-dependent, collective epithelial cell migration within the confines of the tubule basement membrane. Our results establish intimate links between nephron function, fluid flow, and morphogenesis.

  14. C-type period-doubling transition in nephron autoregulation

    DEFF Research Database (Denmark)

    Laugesen, Jakob Lund; Mosekilde, Erik; Holstein-Rathlou, Niels-Henrik

    2011-01-01

    The functional units of the kidney, called nephrons, utilize mechanisms that allow the individual nephron to regulate the incoming blood flow in response to fluctuations in the arterial pressure. This regulation tends to be unstable and to generate self-sustained oscillations, period-doubling bif......The functional units of the kidney, called nephrons, utilize mechanisms that allow the individual nephron to regulate the incoming blood flow in response to fluctuations in the arterial pressure. This regulation tends to be unstable and to generate self-sustained oscillations, period......-doubling bifurcations, mode-locking and other nonlinear dynamic phenomena in the tubular pressures and flows. Using a simplified nephron model, the paper examines how the regulatory mechanisms react to an external periodic variation in arterial pressure near a region of resonance with one of the internally generated...

  15. Electrotonic vascular signal conduction and nephron synchronization

    DEFF Research Database (Denmark)

    Marsh, D.J.; Toma, I.; Sosnovtseva, Olga

    2009-01-01

    Marsh DJ, Toma I, Sosnovtseva OV, Peti-Peterdi J, Holstein-Rathlou NH. Electrotonic vascular signal conduction and nephron synchronization. Am J Physiol Renal Physiol 296: F751-F761, 2009. First published December 30, 2008; doi:10.1152/ajprenal.90669.2008.-Tubuloglomerular feedback (TGF) and the ......Marsh DJ, Toma I, Sosnovtseva OV, Peti-Peterdi J, Holstein-Rathlou NH. Electrotonic vascular signal conduction and nephron synchronization. Am J Physiol Renal Physiol 296: F751-F761, 2009. First published December 30, 2008; doi:10.1152/ajprenal.90669.2008.-Tubuloglomerular feedback (TGF......) and the myogenic mechanism control afferent arteriolar diameter in each nephron and regulate blood flow. Both mechanisms generate self-sustained oscillations, the oscillations interact, TGF modulates the frequency and amplitude of the myogenic oscillation, and the oscillations synchronize; a 5: 1 frequency ratio...... is the most frequent. TGF oscillations synchronize in nephron pairs supplied from a common cortical radial artery, as do myogenic oscillations. We propose that electrotonic vascular signal propagation from one juxtaglomerular apparatus interacts with similar signals from other nephrons to produce...

  16. Renal blood flow and oxygenation drive nephron progenitor differentiation.

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    Rymer, Christopher; Paredes, Jose; Halt, Kimmo; Schaefer, Caitlin; Wiersch, John; Zhang, Guangfeng; Potoka, Douglas; Vainio, Seppo; Gittes, George K; Bates, Carlton M; Sims-Lucas, Sunder

    2014-08-01

    During kidney development, the vasculature develops via both angiogenesis (branching from major vessels) and vasculogenesis (de novo vessel formation). The formation and perfusion of renal blood vessels are vastly understudied. In the present study, we investigated the regulatory role of renal blood flow and O2 concentration on nephron progenitor differentiation during ontogeny. To elucidate the presence of blood flow, ultrasound-guided intracardiac microinjection was performed, and FITC-tagged tomato lectin was perfused through the embryo. Kidneys were costained for the vasculature, ureteric epithelium, nephron progenitors, and nephron structures. We also analyzed nephron differentiation in normoxia compared with hypoxia. At embryonic day 13.5 (E13.5), the major vascular branches were perfused; however, smaller-caliber peripheral vessels remained unperfused. By E15.5, peripheral vessels started to be perfused as well as glomeruli. While the interior kidney vessels were perfused, the peripheral vessels (nephrogenic zone) remained unperfused. Directly adjacent and internal to the nephrogenic zone, we found differentiated nephron structures surrounded and infiltrated by perfused vessels. Furthermore, we determined that at low O2 concentration, little nephron progenitor differentiation was observed; at higher O2 concentrations, more differentiation of the nephron progenitors was induced. The formation of the developing renal vessels occurs before the onset of blood flow. Furthermore, renal blood flow and oxygenation are critical for nephron progenitor differentiation. Copyright © 2014 the American Physiological Society.

  17. Robotic-assisted transperitoneal nephron-sparing surgery for small renal masses with associated surgical procedures: surgical technique and preliminary experience.

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    Ceccarelli, Graziano; Codacci-Pisanelli, Massimo; Patriti, Alberto; Ceribelli, Cecilia; Biancafarina, Alessia; Casciola, Luciano

    2013-09-01

    Small renal masses (T1a) are commonly diagnosed incidentally and can be treated with nephron-sparing surgery, preserving renal function and obtaining the same oncological results as radical surgery. Bigger lesions (T1b) may be treated in particular situations with a conservative approach too. We present our surgical technique based on robotic assistance for nephron-sparing surgery. We retrospectively analysed our series of 32 consecutive patients (two with 2 tumours and one with 4 bilateral tumours), for a total of 37 robotic nephron-sparing surgery (RNSS) performed between June 2008 and July 2012 by a single surgeon (G.C.). The technique differs depending on tumour site and size. The mean tumour size was 3.6 cm; according to the R.E.N.A.L. Nephrometry Score 9 procedures were considered of low, 14 of moderate and 9 of hight complexity with no conversion in open surgery. Vascular clamping was performed in 22 cases with a mean warm ischemia time of 21.5 min and the mean total procedure time was 149.2 min. Mean estimated blood loss was 187.1 ml. Mean hospital stay was 4.4 days. Histopathological evaluation confirmed 19 cases of clear cell carcinoma (all the multiple tumours were of this nature), 3 chromophobe tumours, 1 collecting duct carcinoma, 5 oncocytomas, 1 leiomyoma, 1 cavernous haemangioma and 2 benign cysts. Associated surgical procedures were performed in 10 cases (4 cholecystectomies, 3 important lyses of peritoneal adhesions, 1 adnexectomy, 1 right hemicolectomy, 1 hepatic resection). The mean follow-up time was 28.1 months ± 12.3 (range 6-54). Intraoperative complications were 3 cases of important bleeding not requiring conversion to open or transfusions. Regarding post-operative complications, there were a bowel occlusion, 1 pleural effusion, 2 pararenal hematoma, 3 asymptomatic DVT (deep vein thrombosis) and 1 transient increase in creatinine level. There was no evidence of tumour recurrence in the follow-up. RNSS is a safe and feasible technique

  18. Nephron blood flow dynamics measured by laser speckle contrast imaging

    DEFF Research Database (Denmark)

    von Holstein-Rathlou, Niels-Henrik; Sosnovtseva, Olga V; Pavlov, Alexey N

    2011-01-01

    Tubuloglomerular feedback (TGF) has an important role in autoregulation of renal blood flow and glomerular filtration rate (GFR). Because of the characteristics of signal transmission in the feedback loop, the TGF undergoes self-sustained oscillations in single-nephron blood flow, GFR, and tubular...... simultaneously. The interacting nephron fields are likely to be more extensive. We have turned to laser speckle contrast imaging to measure the blood flow dynamics of 50-100 nephrons simultaneously on the renal surface of anesthetized rats. We report the application of this method and describe analytic...... pressure and flow. Nephrons interact by exchanging electrical signals conducted electrotonically through cells of the vascular wall, leading to synchronization of the TGF-mediated oscillations. Experimental studies of these interactions have been limited to observations on two or at most three nephrons...

  19. Synchronization of tubular pressure oscillations in interacting nephrons

    International Nuclear Information System (INIS)

    Sosnovtseva, O.V.; Postnov, D.E.; Mosekilde, E.; Holstein-Rathlou, N.-H.

    2003-01-01

    The pressure and flow regulation in the individual functional unit of the kidney (the nephron) tends to operate in an unstable regime. For normal rats, the regulation displays regular self-sustained oscillations, but for rats with high blood pressure the oscillations become chaotic. We explain the mechanisms responsible for this behavior and discuss the involved bifurcations. Experimental data show that neighboring nephrons adjust their pressure and flow regulation in accordance with one another. For rats with normal blood pressure, in-phase as well as anti-phase synchronization can be observed. For spontaneously hypertensive rats, indications of chaotic phase synchronization are found. Accounting for a hermodynamics as well as for a vascular coupling between nephrons that share a common interlobular artery, we present a model of the interaction of the pressure and flow regulations between adjacent nephrons. It is shown that this model, with physiologically realistic parameter values, can reproduce the different types of experimentally observed synchronization, including multistability and partial phase synchronization with respect to the slow and fast dynamics

  20. Synchronization of tubular pressure oscillations in interacting nephrons

    Energy Technology Data Exchange (ETDEWEB)

    Sosnovtseva, O.V. E-mail: olga@fysik.dtu.dk; Postnov, D.E.; Mosekilde, E.; Holstein-Rathlou, N.-H

    2003-01-01

    The pressure and flow regulation in the individual functional unit of the kidney (the nephron) tends to operate in an unstable regime. For normal rats, the regulation displays regular self-sustained oscillations, but for rats with high blood pressure the oscillations become chaotic. We explain the mechanisms responsible for this behavior and discuss the involved bifurcations. Experimental data show that neighboring nephrons adjust their pressure and flow regulation in accordance with one another. For rats with normal blood pressure, in-phase as well as anti-phase synchronization can be observed. For spontaneously hypertensive rats, indications of chaotic phase synchronization are found. Accounting for a hermodynamics as well as for a vascular coupling between nephrons that share a common interlobular artery, we present a model of the interaction of the pressure and flow regulations between adjacent nephrons. It is shown that this model, with physiologically realistic parameter values, can reproduce the different types of experimentally observed synchronization, including multistability and partial phase synchronization with respect to the slow and fast dynamics.

  1. Three-Dimensional Reconstruction of the Mouse Nephron

    DEFF Research Database (Denmark)

    Zhai, Xiao-Yue; Thomsen, Jesper Skovhus; Birn, Henrik

    2006-01-01

    Renal function is crucially dependent on renal microstructure which provides the basis for the regulatory mechanisms that control the transport of water and solutes between filtrate and plasma and the urinary concentration. This study provides new, detailed information on mouse renal architecture...... and collecting ducts was performed on aligned digital images, obtained from 2.5-µm-thick serial sections of mouse kidneys. Important new findings were highlighted: (1) A tortuous course of the descending thin limbs of long-looped nephrons and a winding course of the thick ascending limbs of short-looped nephrons...

  2. Bifurcation analysis of nephron pressure and flow regulation

    DEFF Research Database (Denmark)

    Barfred, Mikael; Mosekilde, Erik; Holstein-Rathlou, N.-H.

    1996-01-01

    One- and two-dimensional continuation techniques are applied to study the bifurcation structure of a model of renal flow and pressure control. Integrating the main physiological mechanisms by which the individual nephron regulates the incoming blood flow, the model describes the interaction between...... the tubuloglomerular feedback and the response of the afferent arteriole. It is shown how a Hopf bifurcation leads the system to perform self-sustained oscillations if the feedback gain becomes sufficiently strong, and how a further increase of this parameter produces a folded structure of overlapping period...

  3. Developmental Origins and Nephron Endowment in Hypertension

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    Shari Gurusinghe

    2017-06-01

    Full Text Available Primary hypertension continues to be one of the main risk factors for cardiovascular disease worldwide. A stable intrauterine environment is critical for the future development and health of the fetus. The developing kidney has been found to be especially vulnerable during this time period, and epidemiological studies have demonstrated that an adverse in utero environment is associated with an increased risk of hypertension and chronic kidney disease. Macro- and micronutrient deficiencies as well as exposure to tobacco, alcohol, and certain medications during gestation have been shown to negatively impact nephrogenesis and reduce one’s nephron number. In 1988, Brenner et al. put forth the controversial hypothesis that a reduced nephron complement is a risk factor for hypertension and chronic kidney disease in adulthood. Since then numerous animal and human studies have confirmed this relationship demonstrating that there is an inverse association between blood pressure and nephron number. As our understanding of the developmental programming of hypertension and other non-communicable diseases improves, more effective preventive health measures can be developed in the future.

  4. The mythology of renal function measurement

    International Nuclear Information System (INIS)

    Britton, K.E.

    2003-01-01

    The kidney is a conservative organ. In principle it retains what the body needs, and what is not needed is excreted. It has a number of basic properties. It has the ability to take solutes up from the blood whether by filtration or secretion, which is best called its Uptake function. In the special circumstance where the kidneys are the only exit for the solute from the body, then the rate of loss from the blood is equal to the rate of uptake by the kidney. It has the ability to move solutes among its nephrons, which is its Transit function. The solutes may be absorbed in whole or part and be retained or returned to the blood, its Reabsorption function. In the special case where the solute is non- reabsorbable, then, if there is an increase in salt and water reabsorption as in functionally significant renovascular disease or obstructive nephropathy, the transit function is altered and the transit time through the parenchyme is prolonged. In renovascular disorder the transit time is prolonged through both cortical and juxta-medullary nephrons and collecting ducts. In obstructive nephropathy the transit time is prolonged through the cortical nephrons, but usually is shortened through the juxta-medullary nephrons and collecting ducts due to loss of medullary concentrating ability. After transit through the kidney, the solutes move through the pelvis and ureter, its Excretory function. No more can come out of the kidney then went in previously. If less comes out than what went in, then an increased resistance to outflow is predicted. The balance between excretory function and uptake function is measurable by the Output (Outflow) Efficiency. The kidney also has receptors for hormones, which may modify its reabsorptive functions, for example increased Vasopressin binding decreases the permeability of the collecting duct to water. The kidney also has the ability through enzymes to modify solutes, such as the activation of Vitamin D

  5. Bimodal oscillations in nephron autoregulation

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    Sosnovtseva, Olga; Pavlov, A.N.; Mosekilde, Erik

    2002-01-01

    The individual functional unit of the kidney (the nephron) displays oscillations in its pressure and flow regulation at two different time scales: fast oscillations associated with a myogenic dynamics of the afferent arteriole, and slower oscillations arising from a delay in the tubuloglomerular ...

  6. Reduced nephron endowment in the neonates of Indigenous Australian peoples.

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    Kandasamy, Y; Smith, R; Wright, I M R; Lumbers, E R

    2014-02-01

    Rates of chronic kidney disease (CKD) among Indigenous groups in Australia exceed non-Indigenous rates eight-fold. Using kidney volume as a surrogate for nephron number, we carried out a study to determine if Indigenous neonates have a smaller kidney volume (and thus a reduced nephron number) from birth compared with non-Indigenous neonates. We recruited term and preterm neonates (Indigenous) and 39 term (13 Indigenous) neonates. TKV of Indigenous neonates was significantly lower at 32 weeks [12.0 (2.0) v. 15.4 (5.1) ml; P=0.03] and 38 weeks CA [18.6 (4.0) v. 22.6 (5.9) ml; P=0.04] respectively. Term Indigenous neonates also had smaller kidney volumes compared with non-Indigenous neonates. Despite a smaller kidney volume (and reduced nephron number), Indigenous neonates did not have a significantly lower eGFR. Indigenous neonates achieve similar eGFRs to Non-Indigenous neonates, presumably through a higher single nephron filtration rate. This places Indigenous neonates at a greater risk of long-term kidney damage later in life.

  7. Dynamics of nephron-vascular network

    DEFF Research Database (Denmark)

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

    2012-01-01

    The paper presents a modeling study of the spatial dynamics of a nephro-vascular network consisting of individual nephrons connected via a tree-like vascular branching structure. We focus on the effects of nonlinear mechanisms that are responsible for the formation of synchronous patterns in order...

  8. Selective In Vitro Propagation of Nephron Progenitors Derived from Embryos and Pluripotent Stem Cells

    Directory of Open Access Journals (Sweden)

    Shunsuke Tanigawa

    2016-04-01

    Full Text Available Nephron progenitors in the embryonic kidney propagate while generating differentiated nephrons. However, in mice, the progenitors terminally differentiate shortly after birth. Here, we report a method for selectively expanding nephron progenitors in vitro in an undifferentiated state. Combinatorial and concentration-dependent stimulation with LIF, FGF2/9, BMP7, and a WNT agonist is critical for expansion. The purified progenitors proliferated beyond the physiological limits observed in vivo, both for cell numbers and lifespan. Neonatal progenitors were maintained for a week, while progenitors from embryonic day 11.5 expanded 1,800-fold for nearly 20 days and still reconstituted 3D nephrons containing glomeruli and renal tubules. Furthermore, progenitors generated from mouse embryonic stem cells and human induced pluripotent cells could be expanded with retained nephron-forming potential. Thus, we have established in vitro conditions for promoting the propagation of nephron progenitors, which will be essential for dissecting the mechanisms of kidney organogenesis and for regenerative medicine.

  9. Lgr5+ve Stem/Progenitor Cells Contribute to Nephron Formation during Kidney Development

    Directory of Open Access Journals (Sweden)

    Nick Barker

    2012-09-01

    Full Text Available Multipotent stem cells and their lineage-restricted progeny drive nephron formation within the developing kidney. Here, we document expression of the adult stem cell marker Lgr5 in the developing kidney and assess the stem/progenitor identity of Lgr5+ve cells via in vivo lineage tracing. The appearance and localization of Lgr5+ve cells coincided with that of the S-shaped body around embryonic day 14. Lgr5 expression remained restricted to cell clusters within developing nephrons in the cortex until postnatal day 7, when expression was permanently silenced. In vivo lineage tracing identified Lgr5 as a marker of a stem/progenitor population within nascent nephrons dedicated to generating the thick ascending limb of Henle’s loop and distal convoluted tubule. The Lgr5 surface marker and experimental models described here will be invaluable for deciphering the contribution of early nephron stem cells to developmental defects and for isolating human nephron progenitors as a prerequisite to evaluating their therapeutic potential.

  10. Renal handling of sodium and water in the hypothyroid rat

    Science.gov (United States)

    Michael, Ulrich F.; Barenberg, Robert L.; Chavez, Rafaelita; Vaamonde, Carlos A.; Papper, Solomon

    1972-01-01

    Hypothyroid rats were examined with conventional renal clearance and micropuncture techniques to elicit the mechanism and site within the nephron responsible for the increased salt and water excretion observed in these animals. When compared with age-matched control rats, a decrease in inulin clearance of 30% (P < 0.001) and in Hippuran clearance of 32% (P < 0.005) was observed in the hypothyroid rats. Absolute excretion of sodium and water was increased 3-fold (P < 0.02) and 2-fold (P < 0.025), respectively, while fractional excretion of sodium and water was increased 4.3-fold (P < 0.02) and 2.9-fold (P < 0.05), respectively, in the hypothyroid animals. Fractional proximal reabsorption of sodium as assessed from proximal tubular fluid to plasma ratios of inulin ([TF/P]IN) was found to be decreased by 28% (P < 0.001) in the hypothyroid rats. Superficial single nephron filtration rate was reduced proportionately to the decrease in total filtration rate in the hypothyroid rats. These data indicate that the proximal tubule is one of the sites of diminished sodium and water reabsorption in the hypothyroid rat. The data also suggest that the observed decrease in glomerular filtration rate in the hypothyroid animals is not caused by a decrease in the number of functioning nephrons and that the observed increase in sodium and water excretion is not caused by a redistribution of filtrate from juxtamedullary to superficial nephrons. Although the exact mechanisms of the observed changes in proximal tubular function remain unknown, the data suggest that they are probably related to the lack of thyroid hormone. Whatever their mechanism, it appears that the enhanced sodium and water excretion observed in the hypothyroid animals must be determined by further reduction in tubular sodium reabsorption in the distal nephron. PMID:5024038

  11. Selective In Vitro Propagation of Nephron Progenitors Derived from Embryos and Pluripotent Stem Cells.

    Science.gov (United States)

    Tanigawa, Shunsuke; Taguchi, Atsuhiro; Sharma, Nirmala; Perantoni, Alan O; Nishinakamura, Ryuichi

    2016-04-26

    Nephron progenitors in the embryonic kidney propagate while generating differentiated nephrons. However, in mice, the progenitors terminally differentiate shortly after birth. Here, we report a method for selectively expanding nephron progenitors in vitro in an undifferentiated state. Combinatorial and concentration-dependent stimulation with LIF, FGF2/9, BMP7, and a WNT agonist is critical for expansion. The purified progenitors proliferated beyond the physiological limits observed in vivo, both for cell numbers and lifespan. Neonatal progenitors were maintained for a week, while progenitors from embryonic day 11.5 expanded 1,800-fold for nearly 20 days and still reconstituted 3D nephrons containing glomeruli and renal tubules. Furthermore, progenitors generated from mouse embryonic stem cells and human induced pluripotent cells could be expanded with retained nephron-forming potential. Thus, we have established in vitro conditions for promoting the propagation of nephron progenitors, which will be essential for dissecting the mechanisms of kidney organogenesis and for regenerative medicine. Copyright © 2016 The Authors. Published by Elsevier Inc. All rights reserved.

  12. Nephron progenitor cell death elicits a limited compensatory response associated with interstitial expansion in the neonatal kidney

    Directory of Open Access Journals (Sweden)

    Sree Deepthi Muthukrishnan

    2018-01-01

    Full Text Available The final nephron number in an adult kidney is regulated by nephron progenitor cell availability and collecting duct branching in the fetal period. Fetal environmental perturbations that cause reductions in cell numbers in these two compartments result in low nephron endowment. Previous work has shown that maternal dietary factors influence nephron progenitor cell availability, with both caloric restriction and protein deprivation leading to reduced cell numbers through apoptosis. In this study, we evaluate the consequences of inducing nephron progenitor cell death on progenitor niche dynamics and on nephron endowment. Depletion of approximately 40% of nephron progenitor cells by expression of diphtheria toxin A at embryonic day 15 in the mouse results in 10-20% nephron reduction in the neonatal period. Analysis of cell numbers within the progenitor cell pool following induction of apoptosis reveals a compensatory response in which surviving progenitor cells increase their proliferation and replenish the niche. The proliferative response is temporally associated with infiltration of macrophages into the nephrogenic zone. Colony stimulating factor 1 (CSF1 has a mitogenic effect on nephron progenitor cells, providing a potential explanation for the compensatory proliferation. However, CSF1 also promotes interstitial cell proliferation, and the compensatory response is associated with interstitial expansion in recovering kidneys which can be pharmacologically inhibited by treatment with clodronate liposomes. Our findings suggest that the fetal kidney employs a macrophage-dependent compensatory regenerative mechanism to respond to acute injury caused by death of nephron progenitor cells, but that this regenerative response is associated with neonatal interstitial expansion.

  13. Innervation of the renal proximal convoluted tubule of the rat

    International Nuclear Information System (INIS)

    Barajas, L.; Powers, K.

    1989-01-01

    Experimental data suggest the proximal tubule as a major site of neurogenic influence on tubular function. The functional and anatomical axial heterogeneity of the proximal tubule prompted this study of the distribution of innervation sites along the early, mid, and late proximal convoluted tubule (PCT) of the rat. Serial section autoradiograms, with tritiated norepinephrine serving as a marker for monoaminergic nerves, were used in this study. Freehand clay models and graphic reconstructions of proximal tubules permitted a rough estimation of the location of the innervation sites along the PCT. In the subcapsular nephrons, the early PCT (first third) was devoid of innervation sites with most of the innervation occurring in the mid (middle third) and in the late (last third) PCT. Innervation sites were found in the early PCT in nephrons located deeper in the cortex. In juxtamedullary nephrons, innervation sites could be observed on the PCT as it left the glomerulus. This gradient of PCT innervation can be explained by the different tubulovascular relationships of nephrons at different levels of the cortex. The absence of innervation sites in the early PCT of subcapsular nephrons suggests that any influence of the renal nerves on the early PCT might be due to an effect of neurotransmitter released from renal nerves reaching the early PCT via the interstitium and/or capillaries

  14. Histopathological Validation of the Surface-Intermediate-Base Margin Score for Standardized Reporting of Resection Technique during Nephron Sparing Surgery.

    Science.gov (United States)

    Minervini, Andrea; Campi, Riccardo; Kutikov, Alexander; Montagnani, Ilaria; Sessa, Francesco; Serni, Sergio; Raspollini, Maria Rosaria; Carini, Marco

    2015-10-01

    The surface-intermediate-base margin score is a novel standardized reporting system of resection techniques during nephron sparing surgery. We validated the surgeon assessed surface-intermediate-base score with microscopic histopathological assessment of partial nephrectomy specimens. Between June and August 2014 data were prospectively collected from 40 consecutive patients undergoing nephron sparing surgery. The surface-intermediate-base score was assigned to all cases. The score specific areas were color coded with tissue margin ink and sectioned for histological evaluation of healthy renal margin thickness. Maximum, minimum and mean thickness of healthy renal margin for each score specific area grade (surface [S] = 0, S = 1 ; intermediate [I] or base [B] = 0, I or B = 1, I or B = 2) was reported. The Mann-Whitney U and Kruskal-Wallis tests were used to compare the thickness of healthy renal margin in S = 0 vs 1 and I or B = 0 vs 1 vs 2 grades, respectively. Maximum, minimum and mean thickness of healthy renal margin was significantly different among score specific area grades S = 0 vs 1, and I or B = 0 vs 1, 0 vs 2 and 1 vs 2 (p <0.001). The main limitations of the study are the low number of the I or B = 1 and I or B = 2 samples and the assumption that each microscopic slide reflects the entire score specific area for histological analysis. The surface-intermediate-base scoring method can be readily harnessed in real-world clinical practice and accurately mirrors histopathological analysis for quantification and reporting of healthy renal margin thickness removed during tumor excision. Copyright © 2015 American Urological Association Education and Research, Inc. Published by Elsevier Inc. All rights reserved.

  15. Pathways to nephron loss starting from glomerular diseases-insights from animal models.

    Science.gov (United States)

    Kriz, Wilhelm; LeHir, Michel

    2005-02-01

    Studies of glomerular diseases in animal models show that progression toward nephron loss starts with extracapillary lesions, whereby podocytes play the central role. If injuries remain bound within the endocapillary compartment, they will undergo recovery or be repaired by scaring. Degenerative, inflammatory and dysregulative mechanisms leading to nephron loss are distinguished. In addition to several other unique features, the dysregulative mechanisms leading to collapsing glomerulopathy are particular in that glomeruli and tubules are affected in parallel. In contrast, in degenerative and inflammatory diseases, tubular injury is secondary to glomerular lesions. In both of the latter groups of diseases, the progression starts in the glomerulus with the loss of the separation between the tuft and Bowman's capsule by forming cell bridges (parietal cells and/or podocytes) between the glomerular and the parietal basement membranes. Cell bridges develop into tuft adhesions to Bowman's capsule, which initiate the formation of crescents, either by misdirected filtration (proteinaceous crescents) or by epithelial cell proliferation (cellular crescents). Crescents may spread over the entire circumference of the glomerulus and, via the glomerulotubular junction, may extend onto the tubule. Two mechanisms concerning the transfer of a glomerular injury onto the tubulointerstitium are discussed: (1) direct encroachment of extracapillary lesions and (2) protein leakage into tubular urine, resulting in injury to the tubule and the interstitium. There is evidence that direct encroachment is the crucial mechanism. Progression of chronic renal disease is underlain by a vicious cycle which passes on the damage from lost and/or damaged nephrons to so far healthy nephrons. Presently, two mechanisms are discussed: (1) the loss of nephrons leads to compensatory mechanisms in the remaining nephrons (glomerular hypertension, hyperfiltration, hypertrophy) which increase their

  16. Coupling-induced complexity in nephron models of renal blood flow regulation

    DEFF Research Database (Denmark)

    Laugesen, Jakob Lund; Sosnovtseva, Olga; Mosekilde, Erik

    2010-01-01

    Marsh DJ. Coupling-induced complexity in nephron models of renal blood flow regulation. Am J Physiol Regul Integr Comp Physiol 298: R997-R1006, 2010. First published February 10, 2010; doi: 10.1152/ajpregu.00714.2009.-Tubular pressure and nephron blood flow time series display two interacting...... oscillations in rats with normal blood pressure. Tubulo-glomerular feedback (TGF) senses NaCl concentration in tubular fluid at the macula densa, adjusts vascular resistance of the nephron's afferent arteriole, and generates the slower, larger-amplitude oscillations (0.02-0.04 Hz). The faster smaller...... of glomerular pressure caused by fluctuations of blood pressure. The oscillations become irregular in animals with chronic high blood pressure. TGF feedback gain is increased in hypertensive rats, leading to a stronger interaction between the two mechanisms. With a mathematical model that simulates tubular...

  17. Architecture of the rat nephron-arterial network

    DEFF Research Database (Denmark)

    Marsh, Donald J; Postnov, Dmitry D; Rowland, Douglas

    2017-01-01

    Among solid organs the kidney's vascular network stands out because each nephron has 2 distinct capillary structures in series, and because tubuloglomerular feedback (TGF), one of the mechanisms responsible for blood flow autoregulation, is specific to renal tubules. TGF and the myogenic mechanis...

  18. Postnatal food restriction in the rat as a model for a low nephron endowment

    DEFF Research Database (Denmark)

    Schreuder, Michiel F.; Nyengaard, Jens Randel; Remmers, Floor

    2006-01-01

    A low nephron endowment may be associated with hypertension. Nephrogenesis is the process that leads to the formation of nephrons until week 36 of gestation in humans and may be inhibited by many factors like intrauterine growth restriction and premature birth. To study the consequences of a low ...

  19. Synchronization of Tubular Pressure Oscillations in Interacting Nephrons

    DEFF Research Database (Denmark)

    Sosnovtseva, Olga; Postnov, D.E.; Mosekilde, Erik

    2003-01-01

    The pressure and flow regulation in the individual functional unit of the kidney (the nephron) tends to operate in an unstable regime. For normal rats, the regulation displays regular self-sustained oscillations, but for rats with high blood pressure the oscillations become chaotic. We explain...

  20. Development of a Manipulative for Nephron Physiology Education

    Science.gov (United States)

    Giffen, Zane C.; Carvalho, Helena

    2015-01-01

    Some physiological concepts, such as physiology of filtration and absorption in the different nephron segments, are so detailed that they can be a challenge to be memorized. This article describes an exercise that solidifies learning as students manipulate, using paper models, "transporters" and "electrolytes" in the…

  1. 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

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

    International Nuclear Information System (INIS)

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

    2012-01-01

    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. Mechanisms of temporal variation in single-nephron blood flow in rats

    DEFF Research Database (Denmark)

    Yip, K P; Holstein-Rathlou, N H; Marsh, D J

    1993-01-01

    Modified laser-Doppler velocimetry was used to determine the number of different mechanisms regulating single-nephron blood flow. Two oscillations were identified in star vessel blood flow, one at 20-50 mHz and another at 100-200 mHz. Tubuloglomerular feedback (TGF) mediates the slower oscillation......, and the faster one is probably myogenic in origin. Acute hypertension increased autospectral power in the 20-50 mHz and 100-200 mHz frequency bands to 282 +/- 50 and 248 +/- 64%, respectively, of control even though mean single-nephron blood flow was autoregulated. Mean blood flow increased 24.6 +/- 6.1% when...... components in efferent arteriole blood flow....

  4. Low Birth Weight due to Intrauterine Growth Restriction and/or Preterm Birth: Effects on Nephron Number and Long-Term Renal Health

    Science.gov (United States)

    Zohdi, Vladislava; Sutherland, Megan R.; Lim, Kyungjoon; Gubhaju, Lina; Zimanyi, Monika A.; Black, M. Jane

    2012-01-01

    Epidemiological studies have clearly demonstrated a strong association between low birth weight and long-term renal disease. A potential mediator of this long-term risk is a reduction in nephron endowment in the low birth weight infant at the beginning of life. Importantly, nephrons are only formed early in life; during normal gestation, nephrogenesis is complete by about 32–36 weeks, with no new nephrons formed after this time during the lifetime of the individual. Hence, given that a loss of a critical number of nephrons is the hallmark of renal disease, an increased severity and acceleration of renal disease is likely when the number of nephrons is already reduced prior to disease onset. Low birth weight can result from intrauterine growth restriction (IUGR) or preterm birth; a high proportion of babies born prematurely also exhibit IUGR. In this paper, we describe how IUGR and preterm birth adversely impact on nephrogenesis and how a subsequent reduced nephron endowment at the beginning of life may lead to long-term risk of renal disease, but not necessarily hypertension. PMID:22970368

  5. Low Birth Weight due to Intrauterine Growth Restriction and/or Preterm Birth: Effects on Nephron Number and Long-Term Renal Health

    Directory of Open Access Journals (Sweden)

    Vladislava Zohdi

    2012-01-01

    Full Text Available Epidemiological studies have clearly demonstrated a strong association between low birth weight and long-term renal disease. A potential mediator of this long-term risk is a reduction in nephron endowment in the low birth weight infant at the beginning of life. Importantly, nephrons are only formed early in life; during normal gestation, nephrogenesis is complete by about 32–36 weeks, with no new nephrons formed after this time during the lifetime of the individual. Hence, given that a loss of a critical number of nephrons is the hallmark of renal disease, an increased severity and acceleration of renal disease is likely when the number of nephrons is already reduced prior to disease onset. Low birth weight can result from intrauterine growth restriction (IUGR or preterm birth; a high proportion of babies born prematurely also exhibit IUGR. In this paper, we describe how IUGR and preterm birth adversely impact on nephrogenesis and how a subsequent reduced nephron endowment at the beginning of life may lead to long-term risk of renal disease, but not necessarily hypertension.

  6. Nephron-sparing surgery for bilateral Wilms' tumours: A single ...

    African Journals Online (AJOL)

    All three with unfavourable histology are alive. Four of the five metachronous presentations are alive, as are eight of 12 patients with synchronous bilateral tumours who presented since 2000. Conclusions: Appropriate chemotherapy and nephron-sparing surgery can achieve good results with preservation of adequate renal ...

  7. Insulin activates single amiloride-blockable Na channels in a distal nephron cell line (A6).

    Science.gov (United States)

    Marunaka, Y; Hagiwara, N; Tohda, H

    1992-09-01

    Using the patch-clamp technique, we studied the effect of insulin on an amiloride-blockable Na channel in the apical membrane of a distal nephron cell line (A6) cultured on permeable collagen films for 10-14 days. NPo (N, number of channels per patch membrane; Po, average value of open probability of individual channels in the patch) under baseline conditions was 0.88 +/- 0.12 (SE)(n = 17). After making cell-attached patches on the apical membrane which contained Na channels, insulin (1 mU/ml) was applied to the serosal bath. While maintaining the cell-attached patch, NPo significantly increased to 1.48 +/- 0.19 (n = 17; P less than 0.001) after 5-10 min of insulin application. The open probability of Na channels was 0.39 +/- 0.01 (n = 38) under baseline condition, and increased to 0.66 +/- 0.03 (n = 38, P less than 0.001) after addition of insulin. The baseline single-channel conductance was 4pS, and neither the single-channel conductance nor the current-voltage relationship was significantly changed by insulin. These results indicate that insulin increases Na absorption in the distal nephron by increasing the open probability of the amiloride-blockable Na channel.

  8. The physiological basis and application of renal radionuclide studies

    International Nuclear Information System (INIS)

    Britton, K.E.

    1983-01-01

    A knowledge of the basic physiology of the kidney is essential for an understanding of the application of radionuclide studies in clinical practice. A knowledge of the physiology of the kidney allows one to develop physiological models that are isomorphic and then apply the appropriate type of data analysis in relationship to these models. In this way mistakes in the type of analysis can be avoided and a strong basis for the interpretation of renal radionuclide studies in health and disease is thereby provided. Methods for measuring total renal function, the contribution of each kidney to total renal function, the presence or absence of obstructive nephropathy and the determination of the relative flows to the cortical and juxtamedullary nephrons are given as examples of this approach. (author)

  9. Postembryonic Nephrogenesis and Persistence of Six2-Expressing Nephron Progenitor Cells in the Reptilian Kidney.

    Directory of Open Access Journals (Sweden)

    Troy Camarata

    Full Text Available New nephron formation (nephrogenesis ceases in mammals around birth and is completely absent in adults. In contrast, postembryonic nephrogenesis is well documented in the mesonephric kidneys of fishes and amphibians. The transient mesonephros in reptiles (including birds and mammals is replaced by the metanephros during embryogenesis. Thus, one may speculate that postembryonic nephrogenesis is restricted to the mesonephric kidney. Previous reports have suggested the metanephros of non-avian reptiles (hereafter reptiles may continually form nephrons throughout life. We investigated the presence of adult nephrogenesis in reptiles by examining adult kidneys from several species including Trachemys scripta, Chrysemys picta, Boa constrictor, Tupinambis tegu, Anolis carolinensis, and Alligator mississipiensis among others. We found that all major reptilian groups (Testudines, Crocodylia, and Squamates showed the presence of adult nephrogenesis. The total amount of nephrogenesis varied greatly between species with turtles displaying the highest density of nephrogenesis. In contrast, we were unable to detect adult nephrogenesis in monotremes, and in the iguanid A. carolinensis. Nephron progenitor cells express the transcription factor Six2, which in mammals, becomes downregulated as the progenitor cell population is exhausted and nephrogenesis ends. Using the alligator as a model, we were able to detect Six2-positive cap mesenchyme cells in the adult kidney, which spatially correlated with areas of nephrogenesis. These results suggest that the metanephric kidney of reptiles has maintained the ability to continually grow new nephrons during postembryonic life, a process lost early in mammalian evolution, likely due to the persistence of a Six2-expressing progenitor cell population.

  10. Postembryonic Nephrogenesis and Persistence of Six2-Expressing Nephron Progenitor Cells in the Reptilian Kidney.

    Science.gov (United States)

    Camarata, Troy; Howard, Alexis; Elsey, Ruth M; Raza, Sarah; O'Connor, Alice; Beatty, Brian; Conrad, Jack; Solounias, Nikos; Chow, Priscilla; Mukta, Saima; Vasilyev, Aleksandr

    2016-01-01

    New nephron formation (nephrogenesis) ceases in mammals around birth and is completely absent in adults. In contrast, postembryonic nephrogenesis is well documented in the mesonephric kidneys of fishes and amphibians. The transient mesonephros in reptiles (including birds) and mammals is replaced by the metanephros during embryogenesis. Thus, one may speculate that postembryonic nephrogenesis is restricted to the mesonephric kidney. Previous reports have suggested the metanephros of non-avian reptiles (hereafter reptiles) may continually form nephrons throughout life. We investigated the presence of adult nephrogenesis in reptiles by examining adult kidneys from several species including Trachemys scripta, Chrysemys picta, Boa constrictor, Tupinambis tegu, Anolis carolinensis, and Alligator mississipiensis among others. We found that all major reptilian groups (Testudines, Crocodylia, and Squamates) showed the presence of adult nephrogenesis. The total amount of nephrogenesis varied greatly between species with turtles displaying the highest density of nephrogenesis. In contrast, we were unable to detect adult nephrogenesis in monotremes, and in the iguanid A. carolinensis. Nephron progenitor cells express the transcription factor Six2, which in mammals, becomes downregulated as the progenitor cell population is exhausted and nephrogenesis ends. Using the alligator as a model, we were able to detect Six2-positive cap mesenchyme cells in the adult kidney, which spatially correlated with areas of nephrogenesis. These results suggest that the metanephric kidney of reptiles has maintained the ability to continually grow new nephrons during postembryonic life, a process lost early in mammalian evolution, likely due to the persistence of a Six2-expressing progenitor cell population.

  11. Postembryonic Nephrogenesis and Persistence of Six2-Expressing Nephron Progenitor Cells in the Reptilian Kidney

    Science.gov (United States)

    Camarata, Troy; Howard, Alexis; Elsey, Ruth M.; Raza, Sarah; O’Connor, Alice; Beatty, Brian; Conrad, Jack; Solounias, Nikos; Chow, Priscilla; Mukta, Saima; Vasilyev, Aleksandr

    2016-01-01

    New nephron formation (nephrogenesis) ceases in mammals around birth and is completely absent in adults. In contrast, postembryonic nephrogenesis is well documented in the mesonephric kidneys of fishes and amphibians. The transient mesonephros in reptiles (including birds) and mammals is replaced by the metanephros during embryogenesis. Thus, one may speculate that postembryonic nephrogenesis is restricted to the mesonephric kidney. Previous reports have suggested the metanephros of non-avian reptiles (hereafter reptiles) may continually form nephrons throughout life. We investigated the presence of adult nephrogenesis in reptiles by examining adult kidneys from several species including Trachemys scripta, Chrysemys picta, Boa constrictor, Tupinambis tegu, Anolis carolinensis, and Alligator mississipiensis among others. We found that all major reptilian groups (Testudines, Crocodylia, and Squamates) showed the presence of adult nephrogenesis. The total amount of nephrogenesis varied greatly between species with turtles displaying the highest density of nephrogenesis. In contrast, we were unable to detect adult nephrogenesis in monotremes, and in the iguanid A. carolinensis. Nephron progenitor cells express the transcription factor Six2, which in mammals, becomes downregulated as the progenitor cell population is exhausted and nephrogenesis ends. Using the alligator as a model, we were able to detect Six2-positive cap mesenchyme cells in the adult kidney, which spatially correlated with areas of nephrogenesis. These results suggest that the metanephric kidney of reptiles has maintained the ability to continually grow new nephrons during postembryonic life, a process lost early in mammalian evolution, likely due to the persistence of a Six2-expressing progenitor cell population. PMID:27144443

  12. A hypothesis linking sodium and lithium reabsorption in the distal nephron

    DEFF Research Database (Denmark)

    Thomsen, Klaus; Shirley, DG

    2006-01-01

    through different transport mechanisms: Na(+) via the Na(+)-K(+)-ATPase and Li(+) via the Na(+)/H(+) exchanger. Studies in rats have shown that under normal circumstances hardly any Li(+) is reabsorbed in the distal nephron, so that the urinary excretion of Li(+), expressed as a fraction of the delivery...

  13. Distribution of volumes of individual glomeruli in kidneys at autopsy: association with age, nephron number, birth weight and body mass index.

    Science.gov (United States)

    Hoy, W E; Hughson, M D; Zimanyi, M; Samuel, T; Douglas-Denton, R; Holden, L; Mott, S; Bertram, J F

    2010-11-01

    Glomerular hypertrophy occurs in a number of normal and pathological states. Glomerular volume in kidneys at autopsy is usually indirectly derived from estimates of total glomerular mass and nephron number, and provides only a single value per kidney, with no indication of the range of volumes of glomeruli within the kidney of any given subject. We review findings of the distribution of volumes of different glomeruli within subjects without kidney disease, and their correlations with age, nephron number, birth weight and body mass index (BMI). The study describes findings from autopsy kidneys of selected adult white males from the Southeast USA who had unexpected deaths, and who did not have renal scarring or renal disease. Total glomerular (nephron) number and total glomerular volume were estimated using the disector/fractionator combination, and mean glomerular volume (Vglom) was derived. The volumes of 30 individual glomeruli (IGV) in each subject were determined using the disector/Cavalieri method. IGV values were compared by categories of age, nephron number, birth weight and BMI. There was substantial variation in IGV within subjects. Older age, lower nephron number, lower birth weight and gross obesity were associated with higher mean IGV and with greater IGV heterogeneity. High Vglom and high IGVs were associated with more glomerulosclerosis. However, amongst the generally modest numbers of sclerosed glomeruli, the pattern was uniformly of ischemic collapse of the glomerular tuft. There was no detectable focal segmental glomerular tuft injury. In this series of people without overt renal disease, greater age, nephron deficit, lower birth weight and obesity were marked by glomerular enlargement and greater glomerular volume heterogeneity within individuals.

  14. Combining new tools to assess renal function and morphology: a holistic approach to study the effects of aging and a congenital nephron deficit.

    Science.gov (United States)

    Geraci, Stefania; Chacon-Caldera, Jorge; Cullen-McEwen, Luise; Schad, Lothar R; Sticht, Carsten; Puelles, Victor G; Bertram, John F; Gretz, Norbert

    2017-09-01

    Recently, new methods for assessing renal function in conscious mice (transcutaneous assessment) and for counting and sizing all glomeruli in whole kidneys (MRI) have been described. In the present study, these methods were used to assess renal structure and function in aging mice, and in mice born with a congenital low-nephron endowment. Age-related nephron loss was analyzed in adult C57BL/6 mice (10-50 wk of age), and congenital nephron deficit was assessed in glial cell line-derived neurotrophic factor heterozygous (GDNF HET)-null mutant mice. Renal function was measured through the transcutaneous quantitation of fluorescein isothiocyanate-sinistrin half-life ( t 1/2 ) in conscious mice. MRI was used to image, count, and size cationic-ferritin labeled glomeruli in whole kidneys ex vivo. Design-based stereology was used to validate the MRI measurements of glomerular number and mean volume. In adult C57BL/6 mice, older age was associated with fewer and larger glomeruli, and a rightward shift in the glomerular size distribution. These changes coincided with a decrease in renal function. GNDF HET mice had a congenital nephron deficit that was associated with glomerular hypertrophy and exacerbated by aging. These findings suggest that glomerular hypertrophy and hyperfiltration are compensatory processes that can occur in conjunction with both age-related nephron loss and congenital nephron deficiency. The combination of measurement of renal function in conscious animals and quantitation of glomerular number, volume, and volume distribution provides a powerful new tool for investigating aspects of renal aging and functional changes. Copyright © 2017 the American Physiological Society.

  15. Sphingosine-1-phosphate and renal vasoconstriction

    DEFF Research Database (Denmark)

    Jensen, Boye L

    2018-01-01

    ) and in conjunction with increased S1P release in pathophysiological situations like sepsis and ischemia-reperfusion incidents, this effect could be relevant in acute kidney injury with parallel decreases in renal blood flow and GFR. This article is protected by copyright. All rights reserved.......In the present issue of Acta Physiologica, Guan et al. in their article "Mechanisms of sphingosine-1-phosphate-mediated vasoconstriction of rat afferent arterioles" (1) address the signaling events associated with sphingosine-1-phosphate (S1P)-mediated renal afferent vasoconstriction and show in......, technically demanding, blood-perfused juxtamedullary nephron preparation that S1P signaling relies predominantly on transmembrane calcium influx from the extracellular fluid through L-type calcium channels with contribution from oxidative stress metabolites(1) . So not only is new information on S1P signaling...

  16. Predicting the outcome of chronic kidney disease by the estimated nephron number: The rationale and design of PRONEP, a prospective, multicenter, observational cohort study

    Directory of Open Access Journals (Sweden)

    Imasawa Toshiyuki

    2012-03-01

    Full Text Available Abstract Background The nephron number is thought to be associated with the outcome of chronic kidney disease (CKD. If the nephron number can be estimated in the clinical setting, it could become a strong tool to predict renal outcome. This study was designed to estimate the nephron number in CKD patients and to establish a method to predict the outcome by using the estimated nephron number. Methods/Design The hypothesis of this study is that the estimated nephron number can predict the outcome of a CKD patient. This will be a multicenter, prospective (minimum 3 and maximum 5 years follow-up study. The subjects will comprise CKD patients aged over 14 years who have undergone a kidney biopsy. From January 2011 to March 2013, we will recruit 600 CKD patients from 10 hospitals belonging to the National Hospital Organization of Japan. The primary parameter for assessment is the composite of total mortality, renal death, cerebro-cardiovascular events, and a 50% reduction in the eGFR. The secondary parameter is the rate of eGFR decline per year. The nephron number will be estimated by the glomerular density in biopsy specimens and the renal cortex volume. This study includes one sub-cohort study to establish the equation to calculate the renal cortex volume. Enrollment will be performed at the time of the kidney biopsy, and the data will consist of a medical interview, ultrasound for measurement of the kidney size, blood or urine test, and the pathological findings of the kidney biopsy. Patients will continue to have medical consultations and receive examinations and/or treatment as usual. The data from the patients will be collected once a year after the kidney biopsy until March 2016. All data using this study are easily obtained in routine clinical practice. Discussion This study includes the first trials to estimate the renal cortex volume and nephron number in the general clinical setting. Furthermore, this is the first prospective study to

  17. Cellular interactions via conditioned media induce in vivo nephron generation from tubular epithelial cells or mesenchymal stem cells

    International Nuclear Information System (INIS)

    Machiguchi, Toshihiko; Nakamura, Tatsuo

    2013-01-01

    Highlights: •We have attempted in vivo nephron generation using conditioned media. •Vascular and tubular cells do cross-talks on cell proliferation and tubular changes. •Tubular cells suppress these changes in mesenchymal stem cells. •Tubular cells differentiate mesenchymal stem cells into tubular cells. •Nephrons can be created from implanted tubular cells or mesenchymal stem cells. -- Abstract: There are some successful reports of kidney generation by utilizing the natural course of kidney development, namely, the use of an artificially treated metanephros, blastocyst or ureteric bud. Under a novel concept of cellular interactions via conditioned media (CMs), we have attempted in vivo nephron generation from tubular epithelial cells (TECs) or mesenchymal stem cells (MSCs). Here we used 10× CMs of vascular endothelial cells (VECs) and TECs, which is the first to introduce a CM into the field of organ regeneration. We first present stimulative cross-talks induced by these CMs between VECs and TECs on cell proliferation and morphological changes. In MSCs, TEC-CM suppressed these changes, however, induced cytokeratin expression, indicating the differentiation of MSCs into TECs. As a result, glomerular and tubular structures were created following the implantation of TECs or MSCs with both CMs. Our findings suggest that the cellular interactions via CMs might induce in vivo nephron generation from TECs or MSCs. As a promoting factor, CMs could also be applied to the regeneration of other organs and tissues

  18. Positive surgical margins in nephron-sparing surgery; the great unknown

    Directory of Open Access Journals (Sweden)

    Dan Spinu

    2018-04-01

    Full Text Available There is a currently a general trend towards organ-preserving surgery, and urology is no exception. Specifically, nephron-sparing surgery (NSS has gained general acceptance for T1a renal cell carcinoma (guidelines recommendations. Moreover T1b, T2 and even T3 stage tumors have been included on the nephron sparing list at some centers. An unresolved issue is that of positive surgical margins (PSM, not only their detection but also the implications for follow up and treatment. This paper highlights data available on risk factors for PSM, their clinical relevance, and possible therapeutic consequences. From the surgeon’s viewpoint, NSS is a daring and risky surgical procedure. Urological guidelines stress the importance of NSS, and thus the trend is moving in that direction. Unresolved, however, is the problem of PSM. Trifecta, MIC, and pentafecta are applicable concepts which attempt to define the optimal endpoint of NSS, but further elaboration is necessary. Specifically, research needs to focus less on the concept of definitive margins and more on their identification and avoidance. Although some studies suggest that PSMs do not influence overall survival rate, the basic idea of preserving tissue that is not cancerous leads to further medical, social, and psychological considerations.

  19. Nephron sparing surgery (NSS) for unilateral wilms tumor (UWT): the SIOP 2001 experience

    NARCIS (Netherlands)

    Wilde, Jim C. H.; Aronson, Daniel C.; Sznajder, Beata; van Tinteren, Harm; Powis, Mark; Okoye, Bruce; Cecchetto, Giovanni; Audry, Georges; Fuchs, Jörg; Schweinitz, Dietrich Von; Heij, Hugo; Graf, Norbert; Bergeron, Christophe; Pritchard-Jones, Kathy; van den Heuvel-Eibrink, Marry; Carli, Modesto; Oldenburger, Foppe; Sandstedt, Bengt; de Kraker, Jan; Godzinski, Jan

    2014-01-01

    Total nephrectomy (TN) remains the standard treatment of unilateral Wilms tumors (uWT). The SIOP WT-2001 protocol allowed Nephron Sparing Surgery (NSS) for polar or peripherally non-infiltrating tumors. Inventory of the current SIOP NSS-experience. 2,800 patients with a unilateral, localized or

  20. [Modern biomaterials as hemostatic dressings in kidney nephron sparing surgery (NSS)--murine model. A preliminary report].

    Science.gov (United States)

    Nowacki, Maciej; Jundziłł, Arkadiusz; Bieniek, Miłosz; Kowalczyk, Tomasz; Kloskowski, Tomasz; Drewa, Tomasz

    2012-01-01

    Kidney cancer is now days, one of the main problems in oncological urology. More frequent cases detection of this type of cancer and the implementation of modern methods of treatment, involves the public and good diagnostic radiological imaging methods. Approximately 40% of renal tumors are detected clinically as a changes in T1N0M0 stage. This means that in these patients, surgery can be performed using the method of nephron sparing surgery (NSS), far from consisting the implementation of radical nephrectomy. Unfortunately, despite the saving nature of this type of treatment, NSS methods are associated with local recurrence of tumor formation. Another problem is intra operative bleeding, that's why in order to stop this negative process surgeons currently use hemostatic dressings. Potentially and clinically significant solution could be a combination of this two main problematics points of concern, through the use of modern biomaterials coated on oncostatic substances as a haemostatic dressings, to the prevention of tumor recurrence. The aim of this work, was to present preliminary report of the use of advanced biomaterials, as haemostatic dressings in an experimental technique of nephron sparing surgery on an murine model. In the experiment we use two types of biomaterials and the standard haemostatic dressing used in the nephron sparing surgery (NSS) as a control. We use a polycaprolactone biomaterial obtained by electrospinning. As a second type of biomaterial, we use a homogeneous material with a structure similar to wool, also obtained from medical polycaprolactone by electrospinning. As an murine (in vivo) model in the study, we use 10 C57BL/J mice (with the local ethical committee permission). 8 mice were used in the present study, 2 mice were constituted as a separate control for obtaining the bleeding data. Kidney melanoma cells were implanted under the C57B1/J B16 mouse kidney fibrous capsule, one week before NSS. After 3 weeks the animals were

  1. Application of differential interference contrast with inverted microscopes to the in vitro perfused nephron.

    Science.gov (United States)

    Horster, M; Gundlach, H

    1979-12-01

    The study of in vitro perfused individual nephron segments requires a microscope which provides: (1) easy access to the specimen for measurement of cellular solute flux and voltage; (2) an image with high resolution and contrast; (3) optical sectioning of the object at different levels; and (4) rapid recording of the morphological phenomena. This paper describes an example of commercially available apparatus meeting the above requirements, and illustrates its efficiency. The microscope is of the inverted type (Zeiss IM 35) equipped with differential-interference-contrast (DIC) with a long working distance, and an automatically controlled camera system. The microscopic image exhibits cellular and intercellular details in the unstained transporting mammalian nephron segments despite their tubular structure and great thickness and makes obvious function-structure correlations (e.g. cell volume changes); luminal and contraluminal cell borders are well resolved for controlled microelectrode impalement.

  2. Nephron sparing surgery (NSS) for unilateral wilms tumor (UWT): the SIOP 2001 experience.

    Science.gov (United States)

    Wilde, Jim C H; Aronson, Daniel C; Sznajder, Beata; Van Tinteren, Harm; Powis, Mark; Okoye, Bruce; Cecchetto, Giovanni; Audry, Georges; Fuchs, Jörg; Schweinitz, Dietrich Von; Heij, Hugo; Graf, Norbert; Bergeron, Christophe; Pritchard-Jones, Kathy; Van Den Heuvel-Eibrink, Marry; Carli, Modesto; Oldenburger, Foppe; Sandstedt, Bengt; De Kraker, Jan; Godzinski, Jan

    2014-12-01

    Total nephrectomy (TN) remains the standard treatment of unilateral Wilms tumors (uWT). The SIOP WT-2001 protocol allowed Nephron Sparing Surgery (NSS) for polar or peripherally non-infiltrating tumors. Inventory of the current SIOP NSS-experience. 2,800 patients with a unilateral, localized or metastatic and an unequivocal surgical technique recorded were included. All had neo-adjuvant chemotherapy and delayed surgery. In 91 (3%) NSS was performed and in 2709 TN. Data was retrieved from the SIOP WT 2001 database. NSS group contained 65% stage I tumours and the TN group 48%. Tumor volume (at diagnosis and surgery) was significantly smaller in the NSS group. Within stage III, after NSS, 7/12 (58%) had positive margins (M +), 5 with tumor negative lymph nodes (LN-). After TN, 355/712 (55%) had M + , 182 were LN-. Treatment of M+ in the NSS group resulted in two conversions to TN (one combined with radiotherapy), three patients had radiotherapy only and in two patients local therapy, if given, was not recorded. After NSS, four recurrences occurred. For localized disease the 5-year overall (OS) and event free survival (EFS) in NSS group was 100 and 94.8 (95% CI:89.9-99.9), respectively, while OS and EFS in the TN group were 94.4 (95% CI: 93.2-95.5, log-rank test P = 0.06) and 86.5 (95% CI:85.0-88.1, log-rank test P = 0.06), respectively. NSS was only performed in 3% of patients with uWT. Despite excellent survival with few relapses, the gain of nephrons needs to be weighed against the risk to induce stage III with intensified therapy. © 2014 Wiley Periodicals, Inc.

  3. Associations between age, body size and nephron number with individual glomerular volumes in urban West African males.

    Science.gov (United States)

    McNamara, Bridgette J; Diouf, Boucar; Hughson, Michael D; Hoy, Wendy E; Bertram, John F

    2009-05-01

    Glomerulomegaly has been associated with an increased risk of renal disease. Few reports have investigated the heterogeneity of glomerular size within kidneys and associated risk factors. This study measured the individual glomerular volume (IGV) of 720 non-sclerotic glomeruli in kidneys of adult West African males, and investigated associations of IGV with age, total glomerular (nephron) number and body surface area (BSA). IGVs were determined in the kidneys of 24 Senegalese males from two age groups (12 subjects aged 20- 30 years and 12 subjects aged 50-70 years). Subjects were randomly chosen at autopsies performed at Le Dantec Hospital in Dakar. Volumes of 30 glomeruli per subject were determined using the disector/Cavalieri stereological method. IGVs ranged from 1.31 x 10(6) microm3 to 12.40 x 10(6) microm3 (a 9.4-fold variation). IGV varied up to 5.3-fold within single kidneys. The trimmed range of IGV within subjects (10th to 90th percentile of IGV) was directly correlated with median glomerular size. The mean and standard deviation (SD) of IGV did not differ significantly between age groups or between subjects with higher (> or =1.78 m2) and lower BSA (IGV was significantly and directly correlated with BSA. Kidneys with less than 1 million nephrons had significantly larger mean IGV than kidneys with more than 1 million nephrons, and the trimmed range of IGVs within subjects was inversely correlated with total glomerular number. There was a considerable variation in IGV within kidneys of Senegalese males at autopsy. The heterogeneity of IGV was increased in association with low nephron number and increased BSA, with more pronounced effects in older subjects.

  4. Managing Renal Cell Carcinoma Associated Paraneoplastic Syndrome with Nephron-sparing Surgery in a Patient with von Hippel-Lindau

    Directory of Open Access Journals (Sweden)

    John M. DiBianco

    2017-07-01

    Full Text Available A patient with germline von Hippel-Lindau (VHL gene alteration and history of multiple tumors present with classical paraneoplastic syndrome (PNS associated with renal cell carcinoma (RCC. She underwent open nephron sparing surgery with resolution of symptoms. She remained without recurrence of RCC for the initial 2 years of her follow-up. To the best of our knowledge, this case represents the first in which PNS was specifically resolved using a partial nephrectomy in a patient with VHL. This case report provides initial evidence for the potential role of nephron sparing surgery in the management of paraneoplastic symptoms associated with hereditary RCC.

  5. ROMK inhibitor actions in the nephron probed with diuretics.

    Science.gov (United States)

    Kharade, Sujay V; Flores, Daniel; Lindsley, Craig W; Satlin, Lisa M; Denton, Jerod S

    2016-04-15

    Diuretics acting on specific nephron segments to inhibit Na + reabsorption have been used clinically for decades; however, drug interactions, tolerance, and derangements in serum K + complicate their use to achieve target blood pressure. ROMK is an attractive diuretic target, in part, because its inhibition is postulated to indirectly inhibit the bumetanide-sensitive Na + -K + -2Cl - cotransporter (NKCC2) and the amiloride- and benzamil-sensitive epithelial Na + channel (ENaC). The development of small-molecule ROMK inhibitors has created opportunities for exploring the physiological responses to ROMK inhibition. The present study evaluated how inhibition of ROMK alone or in combination with NKCC2, ENaC, or the hydrochlorothiazide (HCTZ) target NCC alter fluid and electrolyte transport in the nephron. The ROMK inhibitor VU591 failed to induce diuresis when administered orally to rats. However, another ROMK inhibitor, termed compound A, induced a robust natriuretic diuresis without kaliuresis. Compound A produced additive effects on urine output and Na + excretion when combined with HCTZ, amiloride, or benzamil, but not when coadministered with bumetanide, suggesting that the major diuretic target site is the thick ascending limb (TAL). Interestingly, compound A inhibited the kaliuretic response induced by bumetanide and HCTZ, an effect we attribute to inhibition of ROMK-mediated K + secretion in the TAL and CD. Compound A had no effect on heterologously expressed flow-sensitive large-conductance Ca 2+ -activated K + channels (Slo1/β1). In conclusion, compound A represents an important new pharmacological tool for investigating the renal consequences of ROMK inhibition and therapeutic potential of ROMK as a diuretic target. Copyright © 2016 the American Physiological Society.

  6. Nephron-sparing surgery and percutaneous biopsies in renal-cell carcinoma: a global impression among endourologists

    NARCIS (Netherlands)

    Kummerlin, Intan P. E. D.; Borrego, Jaime; Wink, Margot H.; van Dijk, Marleen M.; Wijkstra, Hessel; de La Rosette, Jean J. M. C. H.; Laguna, M. Pilar

    2007-01-01

    BACKGROUND AND PURPOSE: On the one hand, nephron-sparing surgery (NSS) in small renal tumors is a safe and effective alternative to radical nephrectomy. On the other hand, the role of preoperative percutaneous needle biopsies (PNB) remains controversial. The purpose of this study was to evaluate the

  7. Nephron-sparing surgery and percutaneous biopsies in renal-cell carcinoma : a global impression among endourologists

    NARCIS (Netherlands)

    Kummerlin, I.; Borrego, J.; Wink, M.H.; Dijk, van M.M.; Wijkstra, H.; Rosette, de la J.J.M.C.H.; Laguna, M.P.

    2010-01-01

    Background and Purpose: On the one hand, nephron-sparing surgery (NSS) in small renal tumors is a safe and effective alternative to radical nephrectomy. On the other hand, the role of preoperative percutaneous needle biopsies (PNB) remains controversial. The purpose of this study was to evaluate the

  8. Measurement of Na-K-ATPase-mediated rubidium influx in single segments of rat nephron

    Energy Technology Data Exchange (ETDEWEB)

    Cheval, L.; Doucet, A. (Centre National de la Recherche Scientifique, Paris (France))

    1990-07-01

    To determine the functioning rate of Na-K-ATPase in the rat nephron, a micromethod was developed to measure the rate of rubidium uptake in single nephron segments microdissected from collagenase-treated kidneys. Because the hydrolytic activity of Na-K-ATPase displayed the same apparent affinity for K and Rb ions, whereas the Vmax elicited by K was higher than that in the presence of Rb, experiments were performed in the presence of cold Rb plus 86Rb. Before the assay, tubules were preincubated for 10 min at 37 degrees C to restore the normal transmembrane cation gradients. 86Rb uptake was measured after washing out extracellular cations by rinsing the tubules in ice-cold choline chloride solution containing Ba2+. Rb uptake increased quasi-linearly as a function of incubation time up to 30 s in the thick ascending limb, 1 min in the proximal convoluted tubule, and 5 min in the collecting tubule, and reached an equilibrium after 5-30 min. The initial rates of Rb uptake increased in a saturable fashion as Rb concentration in the medium rose from 0.25 to 5 mM. In medullary thick ascending limb, the initial rate of Rb uptake was inhibited by greater than 90% by 2.5 mM ouabain and by 10(-5) M of the metabolic inhibitor carbonyl cyanide trifluoromethoxyphenylhydrazone. Correlation of Na-K-ATPase hydrolytic activity at Vmax and initial rates of ouabain-sensitive Rb uptake in the successive segments of nephron indicates that in intact cells the pump works at approximately 20-30% of its Vmax. Increasing intracellular Na concentration by tubule preincubation in a Rb- and K-free medium increased the initial rates of Rb intake up to the Vmax of the hydrolytic activity of the pump.

  9. Measurement of Na-K-ATPase-mediated rubidium influx in single segments of rat nephron

    International Nuclear Information System (INIS)

    Cheval, L.; Doucet, A.

    1990-01-01

    To determine the functioning rate of Na-K-ATPase in the rat nephron, a micromethod was developed to measure the rate of rubidium uptake in single nephron segments microdissected from collagenase-treated kidneys. Because the hydrolytic activity of Na-K-ATPase displayed the same apparent affinity for K and Rb ions, whereas the Vmax elicited by K was higher than that in the presence of Rb, experiments were performed in the presence of cold Rb plus 86Rb. Before the assay, tubules were preincubated for 10 min at 37 degrees C to restore the normal transmembrane cation gradients. 86Rb uptake was measured after washing out extracellular cations by rinsing the tubules in ice-cold choline chloride solution containing Ba2+. Rb uptake increased quasi-linearly as a function of incubation time up to 30 s in the thick ascending limb, 1 min in the proximal convoluted tubule, and 5 min in the collecting tubule, and reached an equilibrium after 5-30 min. The initial rates of Rb uptake increased in a saturable fashion as Rb concentration in the medium rose from 0.25 to 5 mM. In medullary thick ascending limb, the initial rate of Rb uptake was inhibited by greater than 90% by 2.5 mM ouabain and by 10(-5) M of the metabolic inhibitor carbonyl cyanide trifluoromethoxyphenylhydrazone. Correlation of Na-K-ATPase hydrolytic activity at Vmax and initial rates of ouabain-sensitive Rb uptake in the successive segments of nephron indicates that in intact cells the pump works at approximately 20-30% of its Vmax. Increasing intracellular Na concentration by tubule preincubation in a Rb- and K-free medium increased the initial rates of Rb intake up to the Vmax of the hydrolytic activity of the pump

  10. Preoperative Decision Making for Nephron-Sparing Procedure in the Renal Mass: Time for Using Standard Tools?

    NARCIS (Netherlands)

    Zondervan, Patricia J.; van Lienden, Krijn P.; van Delden, Otto M.; de La Rosette, Jean J. M. C. H.; Laguna, M. Pilar

    2016-01-01

    To determine if the application of using standard tools on tumor complexity and comorbidity indexes may replace the traditional choice of nephron-sparing procedure (NSP) based on clinical maximal tumor diameter (cMTD), age, and comorbidity. Anatomic complexity scores (PADUA and RENAL) and Charlson

  11. Aldosterone-induced signalling and cation transport in the distal nephron.

    LENUS (Irish Health Repository)

    Thomas, Warren

    2008-10-01

    Aldosterone is an important regulator of Na(+) and K(+) transport in the distal nephron modulating the surface expression of transporters through the action of the mineralocorticoid receptor as a ligand-dependent transcription factor. Aldosterone stimulates the rapid activation of protein kinase-based signalling cascades that modulate the genomic effects of the hormone. Evidence is accumulating about the multi-factorial regulation of the epithelial sodium channel (ENaC) by aldosterone. Recent published data suggests that the activation of a novel PKC\\/PKD signalling pathway through the c-Src-dependent trans-activation of epidermal growth factor receptor contributes to early ENaC trafficking in response to aldosterone.

  12. A Large Drawing of a Nephron for Teaching Medical Students Renal Physiology, Histology, and Pharmacology

    Science.gov (United States)

    Robinson, Philip G.; Newman, David; Reitz, Cara L.; Vaynberg, Lena Z.; Bahga, Dalbir K.; Levitt, Morton H.

    2018-01-01

    The purpose of this study is to see whether a large drawing of a nephron helped medical students in self-directed learning groups learn renal physiology, histology, and pharmacology before discussing clinical cases. The end points were the grades on the renal examination and a student survey. The classes in the fall of 2014 and 2015 used the…

  13. An Active Learning Exercise to Facilitate Understanding of Nephron Function: Anatomy and Physiology of Renal Transporters

    Science.gov (United States)

    Dirks-Naylor, Amie J.

    2016-01-01

    Renal transport is a central mechanism underlying electrolyte homeostasis, acid base balance and other essential functions of the kidneys in human physiology. Thus, knowledge of the anatomy and physiology of the nephron is essential for the understanding of kidney function in health and disease. However, students find this content difficult to…

  14. Predicted consequences of diabetes and SGLT inhibition on transport and oxygen consumption along a rat nephron

    Science.gov (United States)

    Vallon, Volker; Edwards, Aurélie

    2016-01-01

    Diabetes increases the reabsorption of Na+ (TNa) and glucose via the sodium-glucose cotransporter SGLT2 in the early proximal tubule (S1-S2 segments) of the renal cortex. SGLT2 inhibitors enhance glucose excretion and lower hyperglycemia in diabetes. We aimed to investigate how diabetes and SGLT2 inhibition affect TNa and sodium transport-dependent oxygen consumption QO2active along the whole nephron. To do so, we developed a mathematical model of water and solute transport from the Bowman space to the papillary tip of a superficial nephron of the rat kidney. Model simulations indicate that, in the nondiabetic kidney, acute and chronic SGLT2 inhibition enhances active TNa in all nephron segments, thereby raising QO2active by 5–12% in the cortex and medulla. Diabetes increases overall TNa and QO2active by ∼50 and 100%, mainly because it enhances glomerular filtration rate (GFR) and transport load. In diabetes, acute and chronic SGLT2 inhibition lowers QO2active in the cortex by ∼30%, due to GFR reduction that lowers proximal tubule active TNa, but raises QO2active in the medulla by ∼7%. In the medulla specifically, chronic SGLT2 inhibition is predicted to increase QO2active by 26% in late proximal tubules (S3 segments), by 2% in medullary thick ascending limbs (mTAL), and by 9 and 21% in outer and inner medullary collecting ducts (OMCD and IMCD), respectively. Additional blockade of SGLT1 in S3 segments enhances glucose excretion, reduces QO2active by 33% in S3 segments, and raises QO2active by SGLT2 blockade in diabetes lowers cortical QO2active and raises medullary QO2active, particularly in S3 segments. PMID:26764207

  15. Clinical, Pathologic, and Functional Outcomes After Nephron-Sparing Surgery in Patients with a Solitary Kidney: A Multicenter Experience

    NARCIS (Netherlands)

    Mues, Adam C.; Korets, Ruslan; Graversen, Joseph A.; Badani, Ketan K.; Bird, Vincent G.; Best, Sara L.; Cadeddu, Jeffrey A.; Clayman, Ralph V.; McDougall, Elspeth; Barwari, Kurdo; Laguna, Pilar; de la Rosette, Jean; Kavoussi, Louis; Okhunov, Zhamshid; Munver, Ravi; Patel, Sutchin R.; Nakada, Stephen; Tsivian, Matvey; Polascik, Thomas J.; Shalhav, Arieh; Shingleton, W. Bruce; Johnson, Emilie K.; Wolf, J. Stuart; Landman, Jaime

    2012-01-01

    Background and Purpose: Surgical management of a renal neoplasm in a solitary kidney is a balance between oncologic control and preservation of renal function. We analyzed patients with a renal mass in a solitary kidney undergoing nephron-sparing procedures to determine perioperative, oncologic, and

  16. Diagnostic and Prognostic Stratification in the Emergency Department Using Urinary Biomarkers of Nephron Damage

    Science.gov (United States)

    Nickolas, Thomas L.; Schmidt-Ott, Kai M.; Canetta, Pietro; Forster, Catherine; Singer, Eugenia; Sise, Meghan; Elger, Antje; Maarouf, Omar; Sola-Del Valle, David Antonio; O'Rourke, Matthew; Sherman, Evan; Lee, Peter; Geara, Abdallah; Imus, Philip; Guddati, Achuta; Polland, Allison; Rahman, Wasiq; Elitok, Saban; Malik, Nasir; Giglio, James; El-Sayegh, Suzanne; Devarajan, Prasad; Hebbar, Sudarshan; Saggi, Subodh J.; Hahn, Barry; Kettritz, Ralph; Luft, Friedrich C.; Barasch, Jonathan

    2012-01-01

    Objectives This study aimed to determine the diagnostic and prognostic value of urinary biomarkers of intrinsic acute kidney injury (AKI) when patients were triaged in the emergency department. Background Intrinsic AKI is associated with nephron injury and results in poor clinical outcomes. Several urinary biomarkers have been proposed to detect and measure intrinsic AKI. Methods In a multicenter prospective cohort study, 5 urinary biomarkers (urinary neutrophil gelatinase–associated lipocalin, kidney injury molecule-1, urinary liver-type fatty acid binding protein, urinary interleukin-18, and cystatin C) were measured in 1,635 unselected emergency department patients at the time of hospital admission. We determined whether the biomarkers diagnosed intrinsic AKI and predicted adverse outcomes during hospitalization. Results All biomarkers were elevated in intrinsic AKI, but urinary neutrophil gelatinase-associated lipocalin was most useful (81% specificity, 68% sensitivity at a 104-ng/ml cutoff) and predictive of the severity and duration of AKI. Intrinsic AKI was strongly associated with adverse in-hospital outcomes. Urinary neutrophil gelatinase-associated lipocalin and urinary kidney injury molecule 1 predicted a composite outcome of dialysis initiation or death during hospitalization, and both improved the net risk classification compared with conventional assessments. These biomarkers also identified a substantial subpopulation with low serum creatinine at hospital admission, but who were at risk of adverse events. Conclusion Urinary biomarkers of nephron damage enable prospective diagnostic and prognostic stratification in the emergency department. PMID:22240130

  17. Unique chloride-sensing properties of WNK4 permit the distal nephron to modulate potassium homeostasis.

    Science.gov (United States)

    Terker, Andrew S; Zhang, Chong; Erspamer, Kayla J; Gamba, Gerardo; Yang, Chao-Ling; Ellison, David H

    2016-01-01

    Dietary potassium deficiency activates thiazide-sensitive sodium chloride cotransport along the distal nephron. This may explain, in part, the hypertension and cardiovascular mortality observed in individuals who consume a low-potassium diet. Recent data suggest that plasma potassium affects the distal nephron directly by influencing intracellular chloride, an inhibitor of the with-no-lysine kinase (WNK)-Ste20p-related proline- and alanine-rich kinase (SPAK) pathway. As previous studies used extreme dietary manipulations, we sought to determine whether the relationship between potassium and NaCl cotransporter (NCC) is physiologically relevant and clarify the mechanisms involved. We report that modest changes in both dietary and plasma potassium affect NCC in vivo. Kinase assay studies showed that chloride inhibits WNK4 kinase activity at lower concentrations than it inhibits activity of WNK1 or WNK3. Also, chloride inhibited WNK4 within the range of distal cell chloride concentration. Mutation of a previously identified WNK chloride-binding motif converted WNK4 effects on SPAK from inhibitory to stimulatory in mammalian cells. Disruption of this motif in WNKs 1, 3, and 4 had different effects on NCC, consistent with the three WNKs having different chloride sensitivities. Thus, potassium effects on NCC are graded within the physiological range, which explains how unique chloride-sensing properties of WNK4 enable it to mediate effects of potassium on NCC in vivo. Copyright © 2015 International Society of Nephrology. Published by Elsevier Inc. All rights reserved.

  18. Nephron segment specific microRNA biomarkers of pre-clinical drug-induced renal toxicity: Opportunities and challenges

    Energy Technology Data Exchange (ETDEWEB)

    Nassirpour, Rounak, E-mail: Rounak.nassirpour@pfizer.com [Drug Safety, Pfizer Worldwide Research and Development, 1 Burtt Rd, Andover, MA 01810 (United States); Ramaiah, Shashi K. [Drug Safety, Pfizer Worldwide Research and Development, 610 Main Street, Cambridge, MA 02139 (United States); Whiteley, Laurence O. [Drug Safety, Pfizer Worldwide Research and Development, 1 Burtt Rd, Andover, MA 01810 (United States)

    2016-12-01

    Drug-induced nephrotoxicity is a common drug development complication for pharmaceutical companies. Sensitive, specific, translatable and non-invasive biomarkers of renal toxicity are urgently needed to diagnose nephron segment specific injury. The currently available gold standard biomarkers for nephrotoxicity are not kidney-specific, lack sensitivity for early detection, and are not suitable for renal damage localization (glomerular vs tubulointerstitial injury). MicroRNAs (miRNAs) are increasingly gaining momentum as promising biomarkers of various organ toxicities, including drug induced renal injury. This is mostly due to their stability in easily accessible biofluids, ease of developing nucleic acids detection compared to protein detection assays, as well as their interspecies translatability. Increasing concordance of miRNA findings by standardizing methodology most suitable for their detection and quantitation, as well as characterization of their expression pattern in a cell type specific manner, will accelerate progress toward validation of these miRNAs as biomarkers in pre-clinical, and clinical settings. This review aims to highlight the current pre-clinical findings surrounding miRNAs as biomarkers in two important segments of the nephron, the glomerulus and tubules. - Highlights: • miRNAs are promising biomarkers of drug-induced kidney injury. • Summarized pre-clinical miRNA biomarkers of drug-induced nephrotoxicity. • Described the strengths and challenges associated with miRNAs as biomarkers.

  19. Impact of preoperative calculation of nephron volume loss on future of partial nephrectomy techniques; planning a strategic roadmap for improving functional preservation and securing oncological safety.

    Science.gov (United States)

    Rha, Koon H; Abdel Raheem, Ali; Park, Sung Y; Kim, Kwang H; Kim, Hyung J; Koo, Kyo C; Choi, Young D; Jung, Byung H; Lee, Sang K; Lee, Won K; Krishnan, Jayram; Shin, Tae Y; Cho, Jin-Seon

    2017-11-01

    To assess the correlation of the resected and ischaemic volume (RAIV), which is a preoperatively calculated volume of nephron loss, with the amount of postoperative renal function (PRF) decline after minimally invasive partial nephrectomy (PN) in a multi-institutional dataset. We identified 348 patients from March 2005 to December 2013 at six institutions. Data on all cases of laparoscopic (n = 85) and robot-assisted PN (n = 263) performed were retrospectively gathered. Univariable and multivariable linear regression analyses were used to identify the associations between various time points of PRF and the RAIV, as a continuous variable. The mean (sd) RAIV was 24.2 (29.2) cm 3 . The mean preoperative estimated glomerular filtration rate (eGFR) and the eGFRs at postoperative day 1, 6 and 36 months after PN were 91.0 and 76.8, 80.2 and 87.7 mL/min/1.73 m 2 , respectively. In multivariable linear regression analysis, the amount of decline in PRF at follow-up was significantly correlated with the RAIV (β 0.261, 0.165, 0.260 at postoperative day 1, 6 and 36 months after PN, respectively). This study has the limitation of its retrospective nature. Preoperatively calculated RAIV significantly correlates with the amount of decline in PRF during long-term follow-up. The RAIV could lead our research to the level of prediction of the amount of PRF decline after PN and thus would be appropriate for assessing the technical advantages of emerging techniques. © 2017 The Authors BJU International © 2017 BJU International Published by John Wiley & Sons Ltd.

  20. Pathophyisiology analysis overload nephron protein in the proximal tubule damage in the nephrolithiasis size stones of 0.6-1.0 sm

    Directory of Open Access Journals (Sweden)

    Yu. Ye. Rohovyi

    2017-07-01

    Full Text Available Nephrolithiasis as the most common urological disorder characterized by frequent early relapses, acquires a social character, because these patients are 30 to 45% of all urological patients, while in Europe the disease is diagnosed in 2% of the population. The study included 40 patients with nephrolithiasis, 10 patients constituted the control group. Set the “hidden” damage to the proximal nephron in the presence of renal stones with a size of 0.6-1.0 cm in the upper third of the ureter, the upper and middle sections of the calyx, which is confirmed by the inhibition of enzymatic fibrinolytic activity of urine, the presence of tubular proteinuria in the absence of inhibition of proximal reabsorption of sodium ions. The link “hidden” damage to the proximal tubule of the degree of overload of the proximal nephron is a protein graphics multicorrelation dependence between the protein concentration of urine, standardized excretion protein and excretion, which are becoming more significant disharmony form towards control in the following sequence: the upper third of the ureter, medium cup, top cup.

  1. Localisation and characteristics of bond sites of aldosterone along the nephron of an amphibian: Xenopus laevis

    International Nuclear Information System (INIS)

    Gnionsahe, Daze Apollinaire

    1986-01-01

    The author reports an academic work which aimed at determining characteristics of the aldosterone bond along the kidney nephron of the Xenopus laevis by using auto-radiography on isolated tubular segments. The objective was to highlight tubular segments at the origin of A6 cells by comparing aldosterone bond characteristics in these cells and in different tubular segments of the kidney. Besides, the author compared the bond distribution between the two aldosterone bond sites: the high affinity type I bond site (so-called mineralocorticoids), and low affinity type II bond site (so-called glucocorticoids)

  2. Tradeoff-in-the-Nephron: A Theory to Explain the Primacy of Phosphate in the Pathogenesis of Secondary Hyperparathyroidism

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    Kenneth R. Phelps

    2017-04-01

    Full Text Available Chronic kidney disease (CKD causes secondary hyperparathyroidism (SHPT. The cardinal features of SHPT are persistence of normocalcemia as CKD progresses and dependence of the parathyroid hormone concentration ([PTH] on phosphate influx (IP. The tradeoff-in-the-nephron hypothesis integrates these features. It states that as the glomerular filtration rate (GFR falls, the phosphate concentration ([P]CDN rises in the cortical distal nephron, the calcium concentration ([Ca]CDN in that segment falls, and [PTH] rises to maintain normal calcium reabsorption per volume of filtrate (TRCa/GFR. In a clinical study, we set GFR equal to creatinine clearance (Ccr and IP equal to the urinary excretion rate of phosphorus (EP. We employed EP/Ccr as a surrogate for [P]CDN. We showed that TRCa/Ccr was high in patients with primary hyperparathyroidism (PHPT and normal in those with SHPT despite comparably increased [PTH] in each group. In subjects with SHPT, we examined regressions of [PTH] on EP/Ccr before and after treatment with sevelamer carbonate or a placebo. All regressions were significant, and ∆[PTH] correlated with ∆EP/Ccr in each treatment cohort. We concluded that [P]CDN determines [PTH] in CKD. This inference explains the cardinal features of SHPT, much of the evidence on which other pathogenic theories are based, and many ancillary observations.

  3. Tradeoff-in-the-Nephron: A Theory to Explain the Primacy of Phosphate in the Pathogenesis of Secondary Hyperparathyroidism

    Science.gov (United States)

    Phelps, Kenneth R.

    2017-01-01

    Chronic kidney disease (CKD) causes secondary hyperparathyroidism (SHPT). The cardinal features of SHPT are persistence of normocalcemia as CKD progresses and dependence of the parathyroid hormone concentration ([PTH]) on phosphate influx (IP). The tradeoff-in-the-nephron hypothesis integrates these features. It states that as the glomerular filtration rate (GFR) falls, the phosphate concentration ([P]CDN) rises in the cortical distal nephron, the calcium concentration ([Ca]CDN) in that segment falls, and [PTH] rises to maintain normal calcium reabsorption per volume of filtrate (TRCa/GFR). In a clinical study, we set GFR equal to creatinine clearance (Ccr) and IP equal to the urinary excretion rate of phosphorus (EP). We employed EP/Ccr as a surrogate for [P]CDN. We showed that TRCa/Ccr was high in patients with primary hyperparathyroidism (PHPT) and normal in those with SHPT despite comparably increased [PTH] in each group. In subjects with SHPT, we examined regressions of [PTH] on EP/Ccr before and after treatment with sevelamer carbonate or a placebo. All regressions were significant, and ∆[PTH] correlated with ∆EP/Ccr in each treatment cohort. We concluded that [P]CDN determines [PTH] in CKD. This inference explains the cardinal features of SHPT, much of the evidence on which other pathogenic theories are based, and many ancillary observations. PMID:28445401

  4. Tradeoff-in-the-Nephron: A Theory to Explain the Primacy of Phosphate in the Pathogenesis of Secondary Hyperparathyroidism.

    Science.gov (United States)

    Phelps, Kenneth R

    2017-04-26

    Chronic kidney disease (CKD) causes secondary hyperparathyroidism (SHPT). The cardinal features of SHPT are persistence of normocalcemia as CKD progresses and dependence of the parathyroid hormone concentration ([PTH]) on phosphate influx (I P ). The tradeoff-in-the-nephron hypothesis integrates these features. It states that as the glomerular filtration rate (GFR) falls, the phosphate concentration ([P] CDN ) rises in the cortical distal nephron, the calcium concentration ([Ca] CDN ) in that segment falls, and [PTH] rises to maintain normal calcium reabsorption per volume of filtrate (TR Ca /GFR). In a clinical study, we set GFR equal to creatinine clearance (C cr ) and I P equal to the urinary excretion rate of phosphorus (E P ). We employed E P /C cr as a surrogate for [P] CDN . We showed that TR Ca /C cr was high in patients with primary hyperparathyroidism (PHPT) and normal in those with SHPT despite comparably increased [PTH] in each group. In subjects with SHPT, we examined regressions of [PTH] on E P /C cr before and after treatment with sevelamer carbonate or a placebo. All regressions were significant, and ∆[PTH] correlated with ∆E P /C cr in each treatment cohort. We concluded that [P] CDN determines [PTH] in CKD. This inference explains the cardinal features of SHPT, much of the evidence on which other pathogenic theories are based, and many ancillary observations.

  5. A QUANTITATIVE METHOD FOR ANALYSING 3-D BRANCHING IN EMBRYONIC KIDNEYS: DEVELOPMENT OF A TECHNIQUE AND PRELIMINARY DATA

    Directory of Open Access Journals (Sweden)

    Gabriel Fricout

    2011-05-01

    Full Text Available The normal human adult kidney contains between 300,000 and 1 million nephrons (the functional units of the kidney. Nephrons develop at the tips of the branching ureteric duct, and therefore ureteric duct branching morphogenesis is critical for normal kidney development. Current methods for analysing ureteric branching are mostly qualitative and those quantitative methods that do exist do not account for the 3- dimensional (3D shape of the ureteric "tree". We have developed a method for measuring the total length of the ureteric tree in 3D. This method is described and preliminary data are presented. The algorithm allows for performing a semi-automatic segmentation of a set of grey level confocal images and an automatic skeletonisation of the resulting binary object. Measurements of length are automatically obtained, and numbers of branch points are manually counted. The final representation can be reconstructed by means of 3D volume rendering software, providing a fully rotating 3D perspective of the skeletonised tree, making it possible to identify and accurately measure branch lengths. Preliminary data shows the total length estimates obtained with the technique to be highly reproducible. Repeat estimates of total tree length vary by just 1-2%. We will now use this technique to further define the growth of the ureteric tree in vitro, under both normal culture conditions, and in the presence of various levels of specific molecules suspected of regulating ureteric growth. The data obtained will provide fundamental information on the development of renal architecture, as well as the regulation of nephron number.

  6. Optimal route of diphtheria toxin administration to eliminate native nephron progenitor cells in vivo for kidney regeneration.

    Science.gov (United States)

    Fukunaga, Shohei; Yamanaka, Shuichiro; Fujimoto, Toshinari; Tajiri, Susumu; Uchiyama, Taketo; Matsumoto, Kei; Ito, Takafumi; Tanabe, Kazuaki; Yokoo, Takashi

    2018-02-19

    To address the lack of organs for transplantation, we previously developed a method for organ regeneration in which nephron progenitor cell (NPC) replacement is performed via the diphtheria toxin receptor (DTR) system. In transgenic mice with NPC-specific expression of DTR, NPCs were eliminated by DT and replaced with NPCs lacking the DTR with the ability to differentiate into nephrons. However, this method has only been verified in vitro. For applications to natural models, such as animal fetuses, it is necessary to determine the optimal administration route and dose of DT. In this study, two DT administration routes (intra-peritoneal and intra-amniotic injection) were evaluated in fetal mice. The fetus was delivered by caesarean section at E18.5, and the fetal mouse kidney and RNA expression were evaluated. Additionally, the effect of the DT dose (25, 5, 0.5, and 0.05 ng/fetus-body) was studied. Intra-amniotic injection of DT led to a reduction in kidney volume, loss of glomeruli, and decreased differentiation marker expression. The intra-peritoneal route was not sufficient for NPC elimination. By establishing that intra-amniotic injection is the optimal administration route for DT, these results will facilitate studies of kidney regeneration in vivo. In addition, this method might be useful for analysis of kidney development at various time points by deleting NPCs during development. Copyright © 2018 Elsevier Inc. All rights reserved.

  7. Conditional ablation of the prorenin receptor in nephron progenitor cells results in developmental programming of hypertension.

    Science.gov (United States)

    Song, Renfang; Kidd, Laura; Janssen, Adam; Yosypiv, Ihor V

    2018-04-01

    Nephron induction during kidney development is driven by reciprocal interactions between progenitor cells (NPCs) of the cap mesenchyme (CM) and the ureteric bud (UB). The prorenin receptor (PRR) is a receptor for renin and prorenin, and an accessory subunit of the vacuolar proton pump V-ATPase. Previously, we demonstrated that conditional ablation of the PRR in Six2 + NPCs in mice (Six2 PRR -/- ) causes early neonatal death. Here, we identified genes that are regulated by PRR in Six2 + NPCs FACS-isolated from Six2 PRR -/- and control kidneys on embryonic day E15.5 using whole-genome expression analysis. Seven genes with expression in CM cells previously shown to direct kidney development, including Notch1, β-catenin, Lef1, Lhx1, Jag1, and p53, were downregulated. The functional groups within the downregulated gene set included genes involved in embryonic and cellular development, renal regeneration, cellular assembly and organization, cell morphology, death and survival. Double-transgenic Six2 PRR -/- /BatGal + mice, a reporter strain for β-catenin transcriptional activity, showed decreased β-catenin activity in the UB in vivo. Reduced PRR gene dosage in heterozygous Six2 PRR +/- mice was associated with decreased glomerular number, segmental thickening of the glomerular basement membrane with focal podocyte foot process effacement, development of hypertension and increased soluble PRR (sPRR) levels in the urine at 2 months of age. Together, these data demonstrate that NPC PRR performs essential functions during nephrogenesis via control of hierarchy of genes that regulate critical cellular processes. Both reduced nephron endowment and augmented urine sPRR likely contribute to programming of hypertension in Six2 PRR +/- mice. © 2018 The Authors. Physiological Reports published by Wiley Periodicals, Inc. on behalf of The Physiological Society and the American Physiological Society.

  8. Diagnostic and prognostic stratification in the emergency department using urinary biomarkers of nephron damage: a multicenter prospective cohort study.

    Science.gov (United States)

    Nickolas, Thomas L; Schmidt-Ott, Kai M; Canetta, Pietro; Forster, Catherine; Singer, Eugenia; Sise, Meghan; Elger, Antje; Maarouf, Omar; Sola-Del Valle, David Antonio; O'Rourke, Matthew; Sherman, Evan; Lee, Peter; Geara, Abdallah; Imus, Philip; Guddati, Achuta; Polland, Allison; Rahman, Wasiq; Elitok, Saban; Malik, Nasir; Giglio, James; El-Sayegh, Suzanne; Devarajan, Prasad; Hebbar, Sudarshan; Saggi, Subodh J; Hahn, Barry; Kettritz, Ralph; Luft, Friedrich C; Barasch, Jonathan

    2012-01-17

    This study aimed to determine the diagnostic and prognostic value of urinary biomarkers of intrinsic acute kidney injury (AKI) when patients were triaged in the emergency department. Intrinsic AKI is associated with nephron injury and results in poor clinical outcomes. Several urinary biomarkers have been proposed to detect and measure intrinsic AKI. In a multicenter prospective cohort study, 5 urinary biomarkers (urinary neutrophil gelatinase-associated lipocalin, kidney injury molecule-1, urinary liver-type fatty acid binding protein, urinary interleukin-18, and cystatin C) were measured in 1,635 unselected emergency department patients at the time of hospital admission. We determined whether the biomarkers diagnosed intrinsic AKI and predicted adverse outcomes during hospitalization. All biomarkers were elevated in intrinsic AKI, but urinary neutrophil gelatinase-associated lipocalin was most useful (81% specificity, 68% sensitivity at a 104-ng/ml cutoff) and predictive of the severity and duration of AKI. Intrinsic AKI was strongly associated with adverse in-hospital outcomes. Urinary neutrophil gelatinase-associated lipocalin and urinary kidney injury molecule 1 predicted a composite outcome of dialysis initiation or death during hospitalization, and both improved the net risk classification compared with conventional assessments. These biomarkers also identified a substantial subpopulation with low serum creatinine at hospital admission, but who were at risk of adverse events. Urinary biomarkers of nephron damage enable prospective diagnostic and prognostic stratification in the emergency department. Copyright © 2012 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.

  9. The Zhongshan score: a novel and simple anatomic classification system to predict perioperative outcomes of nephron-sparing surgery.

    Science.gov (United States)

    Zhou, Lin; Guo, Jianming; Wang, Hang; Wang, Guomin

    2015-02-01

    In the zero ischemia era of nephron-sparing surgery (NSS), a new anatomic classification system (ACS) is needed to adjust to these new surgical techniques. We devised a novel and simple ACS, and compared it with the RENAL and PADUA scores to predict the risk of NSS outcomes. We retrospectively evaluated 789 patients who underwent NSS with available imaging between January 2007 and July 2014. Demographic and clinical data were assessed. The Zhongshan (ZS) score consisted of three parameters. RENAL, PADUA, and ZS scores are divided into three groups, that is, high, moderate, and low scores. For operative time (OT), significant differences were seen between any two groups of ZS score and PADUA score (all P RENAL showed no significant difference between moderate and high complexity in OT, WIT, estimated blood loss, and increase in SCr. Compared with patients with a low score of ZS, those with a high or moderate score had 8.1-fold or 3.3-fold higher risk of surgical complications, respectively (all P RENAL score, patients with a high or moderate score had 5.7-fold or 1.9-fold higher risk of surgical complications, respectively (all P RENAL and PADUA scores. ZS score could be used to reflect the surgical complexity and predict the risk of surgical complications in patients undergoing NSS.

  10. Successful Endovascular Control of Renal Artery in a Transplant Kidney During Nephron Sparing Surgery (NSS) for Large Centrally Located Tumor.

    Science.gov (United States)

    Shprits, Sagi; Moskovits, Boaz; Sachner, Robert; Nativ, Ofer

    2016-05-01

    Renal cell carcinoma in a transplant kidney is a rare condition. Nephron Sparing Surgery (NSS) is the treatment of choice. One of the main technical challenges is obtaining adequate vascular control. We present a rare case of large centrally located hillar tumor in a kidney 18 years after transplantation treated with NSS. Vascular control was achieved by using a novel approach. Post-operative course was uneventful with minimal decrease in renal function. We believe that this unique choice of treatment can be used in cases of NSS where the access to the renal pedicle is limited.

  11. Simple radioisotopic technique for the study of urate transport in the rat kidney

    International Nuclear Information System (INIS)

    Abramson, R.G.; Levitt, M.F.; Maesaka, J.K.; Katz, J.H.

    1974-01-01

    To study uric acid transport in single nephrons and whole kidney of the rat, a technique has been developed for the radioassay of uric acid-2- 14 C in plasma, urine, and tubular fluid. Labeled allantoin, which results from the in vivo oxidation of uric acid-2- 14 C, is readily separated from the labeled uric acid by a two-step elution from a strongly basic anion exchange resin using column chromatography. It is concluded that this radioassay is a valid technique and that it provides a more sensitive and precise means of measuring U/P uric acid ratios at endogenous plasma uric acid concentrations than does a conventional differential spectrophotometric method

  12. Second messenger production in avian medullary nephron segments in response to peptide hormones.

    Science.gov (United States)

    Goldstein, D L; Reddy, V; Plaga, K

    1999-03-01

    We examined the sites of peptide hormone activation within medullary nephron segments of the house sparrow (Passer domesticus) kidney by measuring rates of hormone-induced generation of cyclic nucleotide second messenger. Thin descending limbs, thick ascending limbs, and collecting ducts had baseline activity of adenylyl cyclase that resulted in cAMP accumulation of 207 +/- 56, 147 +/- 31, and 151 +/- 41 fmol. mm-1. 30 min-1, respectively. In all segments, this activity increased 10- to 20-fold in response to forskolin. Activity of adenylyl cyclase in the thin descending limb was stimulated approximately twofold by parathyroid hormone (PTH) but not by any of the other hormones tested [arginine vasotocin (AVT), glucagon, atrial natriuretic peptide (ANP), or isoproterenol, each at 10(-6) M]. Thick ascending limb was stimulated two- to threefold by both AVT and PTH; however, glucagon and isoproterenol had no effect, and ANP stimulated neither cAMP nor cGMP accumulation. Adenylyl cyclase activity in the collecting duct was stimulated fourfold by AVT but not by the other hormones; likewise, ANP did not stimulate cGMP accumulation in this segment. These data support a tubular action of AVT and PTH in the avian renal medulla.

  13. Transgenic Xenopus laevis Line for In Vivo Labeling of Nephrons within the Kidney

    Directory of Open Access Journals (Sweden)

    Mark E. Corkins

    2018-04-01

    Full Text Available Xenopus laevis embryos are an established model for studying kidney development. The nephron structure and genetic pathways that regulate nephrogenesis are conserved between Xenopus and humans, allowing for the study of human disease-causing genes. Xenopus embryos are also amenable to large-scale screening, but studies of kidney disease-related genes have been impeded because assessment of kidney development has largely been limited to examining fixed embryos. To overcome this problem, we have generated a transgenic line that labels the kidney. We characterize this cdh17:eGFP line, showing green fluorescent protein (GFP expression in the pronephric and mesonephric kidneys and colocalization with known kidney markers. We also demonstrate the feasibility of live imaging of embryonic kidney development and the use of cdh17:eGFP as a kidney marker for secretion assays. Additionally, we develop a new methodology to isolate and identify kidney cells for primary culture. We also use morpholino knockdown of essential kidney development genes to establish that GFP expression enables observation of phenotypes, previously only described in fixed embryos. Taken together, this transgenic line will enable primary kidney cell culture and live imaging of pronephric and mesonephric kidney development. It will also provide a simple means for high-throughput screening of putative human kidney disease-causing genes.

  14. Robotic partial nephrectomy for complex renal tumors: surgical technique.

    Science.gov (United States)

    Rogers, Craig G; Singh, Amar; Blatt, Adam M; Linehan, W Marston; Pinto, Peter A

    2008-03-01

    Laparoscopic partial nephrectomy requires advanced training to accomplish tumor resection and renal reconstruction while minimizing warm ischemia times. Complex renal tumors add an additional challenge to a minimally invasive approach to nephron-sparing surgery. We describe our technique, illustrated with video, of robotic partial nephrectomy for complex renal tumors, including hilar, endophytic, and multiple tumors. Robotic assistance was used to resect 14 tumors in eight patients (mean age: 50.3 yr; range: 30-68 yr). Three patients had hereditary kidney cancer. All patients had complex tumor features, including hilar tumors (n=5), endophytic tumors (n=4), and/or multiple tumors (n=3). Robotic partial nephrectomy procedures were performed successfully without complications. Hilar clamping was used with a mean warm ischemia time of 31 min (range: 24-45 min). Mean blood loss was 230 ml (range: 100-450 ml). Histopathology confirmed clear-cell renal cell carcinoma (n=3), hybrid oncocytic tumor (n=2), chromophobe renal cell carcinoma (n=2), and oncocytoma (n=1). All patients had negative surgical margins. Mean index tumor size was 3.6 cm (range: 2.6-6.4 cm). Mean hospital stay was 2.6 d. At 3-mo follow-up, no patients experienced a statistically significant change in serum creatinine or estimated glomerular filtration rate and there was no evidence of tumor recurrence. Robotic partial nephrectomy is safe and feasible for select patients with complex renal tumors, including hilar, endophytic, and multiple tumors. Robotic assistance may facilitate a minimally invasive, nephron-sparing approach for select patients with complex renal tumors who might otherwise require open surgery or total nephrectomy.

  15. Robotic-assisted partial nephrectomy: surgical technique using a 3-arm approach and sliding-clip renorrhaphy

    Directory of Open Access Journals (Sweden)

    Jose M. Cabello

    2009-04-01

    Full Text Available INTRODUCTION: For the treatment of renal tumors, minimally invasive nephron-sparing surgery has become increasingly performed due to proven efficiency and excellent functional and oncological outcomes. The introduction of robotics into urologic laparoscopic surgery has allowed surgeons to perform challenging procedures in a reliable and reproducible manner. We present our surgical technique for robotic assisted partial nephrectomy (RPN using a 3-arm approach, including a sliding-clip renorrhaphy. MATERIAL AND METHODS: Our RPN technique is presented which describes the trocar positioning, hilar dissection, tumor identification using intraoperative ultrasound for margin determination, selective vascular clamping, tumor resection, and reconstruction using a sliding-clip technique. CONCLUSION: RPN using a sliding-clip renorrhaphy is a valid and reproducible surgical technique that reduces the challenge of the procedure by taking advantage of the enhanced visualization and control afforded by the robot. The renorrhaphy described is performed under complete control of the console surgeon, and has demonstrated a reduction in the warm ischemia times in our series.

  16. [Augmented reality for image guided therapy (ARIGT) of kidney tumor during nephron sparing surgery (NSS): animal model and clinical approach].

    Science.gov (United States)

    Drewniak, Tomasz; Rzepecki, Maciej; Juszczak, Kajetan; Kwiatek, Wojciech; Bielecki, Jakub; Zieliński, Krzysztof; Ruta, Andrzej; Czekierda, Łukasz; Moczulskis, Zbigniew

    2011-01-01

    The main problem in nephron sparing surgery (NSS) is to preserve renal tumors oncological purity during the removal of the tumor with a margin of macroscopically unchanged kidney tissue while keeping the largest possible amount of normal parenchyma of the operated kidney. The development of imaging techniques, in particular IGT (Image Guided Therapy) allows precise imaging of the surgical field and, therefore, is essential in improving the effectiveness of NSS (increase of nephron sparing with the optimal radicality). The aim of this study was to develop a method of the three-dimensional (3D) imaging of the kidney tumor and its lodge in the operated kidney using 3D laser scanner during NSS procedure. Additionally, the animal model of visualization was developed. The porcine kidney model was used to test the set built up with HD cameras and linear laser scanner connected to a laptop with graphic software (David Laser Scanner, Germany) showing the surface of the kidney and the lodge after removal the chunk of renal parenchyma. Additionally, the visualization and reconstruction was performed on animal porcine model. Moreover, 5 patients (3 women, 2 men) aged from 37 to 68 years (mean 56), diagnosed with kidney tumors in CT scans with a diameter of 3.7-6.9 cm (mean 4.9) were operated in our Department this year, scanning the surface during the treatment with the kidney tumor and kidney tumor after it is removed with a margin of renal tissue. In one case, the lodge of removed tumor was scanned. Dimensions in 3D reconstruction images of laser scans in the study of animal model and the images obtained intraoperatively were compared with the dimensions evaluated during preoperative CT scans, intraoperative measurements. Three-dimensional imaging laser scanner operating field loge resected tumor and the tumor on the kidney of animal models and during NSS treatments for patients with kidney tumors is possible in real time with an accuracy of -2 mm do +9 mm (+/- 3 mm). The

  17. Nephron sparing surgery as the treatment of choice in renal cell carcinoma

    International Nuclear Information System (INIS)

    Wyczolkowski, M.; Drewniak, T.; Klima, W.; Rzepecki, M.; Prajsner, A.; Kajetan Juszczak, K.

    2010-01-01

    Advances in imaging diagnostics have contributed to the frequent detection of small kidney tumours both at an early stage and of low grade. Although radical nephrectomy is still the gold standard in Renal Cell Carcinoma (RCC) treatment, yet it slowly ceases to be the standard approach and open or laparoscopic Nephron Sparing Surgery (NSS) is becoming more and more common. Ai m. The purpose of the study was to determine the functional and oncological outcomes of NSS for RCC basing on an analysis of 108 patients. Material and methods. The patients were divided into two groups: T1a (≤ 4 cm) and T1b (≥ 4 ≤ 7 cm). We performed an analysis of all patients with a minimal follow-up time of 24 months. In the majority of patients the diagnosis was clear cell carcinoma(83.9%). Results. G2 tumours were the most common (51.7%). The cumulative proportion of survivors without local relapse within the operated kidney and/or in the local lymph nodes and without distant metastases after 2 and 3 years was 99% and 93%, respectively. Our results support the fact that in pT1a and pT1b patients NSS is a safe and effective procedure. The size of pT1 tumours has no bearing on 2-year and 3-year recurrence-free survivals. Conclusion. Intraoperative ultrasound allows for further identification of additional neo plasmatic foci and for the use of the best surgical approach. Intraoperative ultrasound is useful in NSS, and especially in those cases, where the tumor lies in the central part of the kidney. (authors)

  18. Dopaminergic Immunofluorescence Studies in Kidney Tissue.

    Science.gov (United States)

    Gildea, J J; Van Sciver, R E; McGrath, H E; Kemp, B A; Jose, P A; Carey, R M; Felder, R A

    2017-01-01

    The kidney is a highly integrated system of specialized differentiated cells that are responsible for fluid and electrolyte balance in the body. While much of today's research focuses on isolated nephron segments or cells from nephron segments grown in tissue culture, an often overlooked technique that can provide a unique view of many cell types in the kidney is slice culture. Here, we describe techniques that use freshly excised kidney tissue from rats to perform a variety of experiments shortly after isolating the tissue. By slicing the rat kidney in a "bread loaf" format, multiple studies can be performed on slices from the same tissue in parallel. Cryosectioning and staining of the tissue allow for the evaluation of physiological or biochemical responses in a wide variety of specific nephron segments. The procedures described within this chapter can also be extended to human or mouse kidney tissue.

  19. Charles Edward Isaacs (1811-1860): exploring the details of nephron structure and function in the post-Bowman period.

    Science.gov (United States)

    Fine, Leon G

    2003-01-01

    Charles Edward Isaacs (1811-1860), an anatomist working in New York, undertook a series of studies which attempted to define the microscopic structure of the nephrons in a variety of species. Given that he published his findings 15 years after William Bowman's seminal paper on the subject, he was able to add only a few of the finer details to the picture. He observed the continuity of the epithelium of the glomerular capsule with that of the proximal tubule and he demonstrated that the glomerular tuft is covered by a layer of epithelial cells. In a series of studies on human renal function he erroneously concluded that the glomerulus must have an excretory function in addition to its filtration function and that diuretics act primarily on the glomerlus. The latter conclusion was based upon observations of substances not currently categorized as being diuretic agents. The absence of a major conceptual advance in the writings of Isaacs probably accounts for that fact that his contribution has been largely forgotten.

  20. A new technique for the use of microspheres for the study of intra-cortical distribution of renal blood flow. Results for a normal and sodium overloaded rat. Report of internship performed in the Laboratoire de Physiologie Physico-Chimique (C.E.N. Saclay)

    International Nuclear Information System (INIS)

    Poujeol, P.

    1972-06-01

    This academic work reports the simultaneous study on the same kidney of the distribution of glomerular filtrations and the distribution of blood flow rate in the renal cortex. Th author combined the technique of perfusion of sodium "1"4C ferro-cyanide which allows the measurement of individual glomerular filtrations, and a technique based on the use of microspheres which allows the assessment of blood flow distribution in the glomeruli of different nephron classes. Experiments have been performed on a normal rat, and on a rat submitted to a chronic NaCl overload [fr

  1. Nephron-sparing percutaneous ablation of a 5 cm renal cell carcinoma by superselective embolization and percutaneous RF-ablation

    International Nuclear Information System (INIS)

    Tacke, J.; Mahnken, A.; Buecker, A.; Guenther, R.W.; Rohde, D.

    2001-01-01

    Purpose: To report on the nephron-sparing, percutaneous ablation of a large renal cell carcinoma by combined superselective embolization and percutaneous radiofrequency ablation. Materials and Methods: A 5 cm renal cell carcinoma of a 43-year-old drug abusing male with serologically proven HIV, hepatitis B and C infection, who refused surgery, was superselectively embolized using microspheres (size: 500 - 700 μm) and a platinum coil under local anesthesia. Percutaneous radiofrequency ablation using a 7F LeVeen probe (size of expanded probe tip: 40 mm) and a 200 Watt generator was performed one day after transcatheter embolization under general anesthesia. Results: The combined treatment resulted in complete destruction of the tumor without relevant damage of the surrounding healthy renal tissue. The patient was discharged 24 hours after RF ablation. No complications like urinary leaks or fistulas were observed and follow up CT one day and 4 weeks after the radiofrequency intervention revealed no signs of residual tumor growth. Conclusion: The combined transcatheter embolization and percutaneous radiofrequency ablation of renal cell carcinoma has proved technically feasible, effective, and safe in this patient. It may be offered as an alternative treatment to partial or radical nephrectomy under certain circumstances. Abbreviations: RF = radiofrequency ablation; CT = computed tomography; HIV = human immunodeficiency virus. (orig.) [de

  2. Changes in glomerular parietal epithelial cells in mouse kidneys with advanced age

    Science.gov (United States)

    Roeder, Sebastian S.; Stefanska, Ania; Eng, Diana G.; Kaverina, Natalya; Sunseri, Maria W.; McNicholas, Bairbre A.; Rabinovitch, Peter; Engel, Felix B.; Daniel, Christoph; Amann, Kerstin; Lichtnekert, Julia; Pippin, Jeffrey W.

    2015-01-01

    Kidney aging is accompanied by characteristic changes in the glomerulus, but little is known about the effect of aging on glomerular parietal epithelial cells (PECs), nor if the characteristic glomerular changes in humans and rats also occur in very old mice. Accordingly, a descriptive analysis was undertaken in 27-mo-old C57B6 mice, considered advanced age. PEC density was significantly lower in older mice compared with young mice (aged 3 mo), and the decrease was more pronounced in juxtamedullary glomeruli compared with outer cortical glomeruli. In addition to segmental and global glomerulosclerosis in older mice, staining for matrix proteins collagen type IV and heparan sulfate proteoglycan were markedly increased in Bowman's capsules of older mouse glomeruli, consistent with increased extracellular matrix production by PECs. De novo staining for CD44, a marker of activated and profibrotic PECs, was significantly increased in aged glomeruli. CD44 staining was more pronounced in the juxtamedullary region and colocalized with phosphorylated ERK. Additionally, a subset of aged PECs de novo expressed the epithelial-to-mesenchymal transition markers α-smooth muscle and vimentin, with no changes in epithelial-to-mesenchymal transition markers E-cadherin and β-catenin. The mural cell markers neural/glial antigen 2, PDGF receptor-β, and CD146 as well as Notch 3 were also substantially increased in aged PECs. These data show that mice can be used to better understand the aging kidney and that PECs undergo substantial changes, especially in juxtamedullary glomeruli, that may participate in the overall decline in glomerular structure and function with advancing age. PMID:26017974

  3. Glomerular hypertrophy in subjects with low nephron number: contributions of sex, body size and race.

    Science.gov (United States)

    Puelles, Victor G; Douglas-Denton, Rebecca N; Zimanyi, Monika A; Armitage, James A; Hughson, Michael D; Kerr, Peter G; Bertram, John F

    2014-09-01

    We have shown that low nephron number (Nglom) is a strong determinant of individual glomerular volume (IGV) in male Americans. However, whether the same pattern is present in female Americans remains unclear. The contributions of body surface area (BSA) and race to IGV in the context of Nglom also require further evaluation. Kidneys without overt renal disease were collected at autopsy in Mississippi, USA. The extremes of female Nglom were used to define high and low Nglom for both sexes. Nglom and IGV were estimated by design-based stereology. A total of 24 African and Caucasian American females (n = 12 per race; 6 per Nglom extreme) were included. These subjects were subsequently matched to 24 comparable males by age and Nglom and to 18 additional males by age, Nglom and BSA. IGV average and variance were very similar in female African and Caucasian Americans with high and low Nglom. Males with low Nglom from both races showed greater IGV average and variance than comparable females matched by age and Nglom. These differences in IGV between sexes were not observed in Caucasian Americans with low Nglom that were matched by age, Nglom and BSA. In contrast, glomeruli from African Americans were larger than those from Caucasian Americans, especially in subjects with high Nglom. While female Americans with low Nglom did not show glomerular hypertrophy, comparable males with low Nglom showed marked glomerular hypertrophy that was closely associated with high BSA. Glomerular size in African Americans may be confounded by multiple additional factors. © The Author 2014. Published by Oxford University Press on behalf of ERA-EDTA. All rights reserved.

  4. Deficiency of the Angiotensinase Aminopeptidase A Increases Susceptibility to Glomerular Injury.

    Science.gov (United States)

    Velez, Juan Carlos Q; Arif, Ehtesham; Rodgers, Jessalyn; Hicks, Megan P; Arthur, John M; Nihalani, Deepak; Bruner, Evelyn T; Budisavljevic, Milos N; Atkinson, Carl; Fitzgibbon, Wayne R; Janech, Michael G

    2017-07-01

    Aminopeptidase A (APA) is expressed in glomerular podocytes and tubular epithelia and metabolizes angiotensin II (AngII), a peptide known to promote glomerulosclerosis. In this study, we tested whether APA expression changes in response to progressive nephron loss or whether APA exerts a protective role against glomerular damage and during AngII-mediated hypertensive kidney injury. At advanced stages of FSGS, fawn-hooded hypertensive rat kidneys exhibited distinctly increased APA staining in areas of intact glomerular capillary loops. Moreover, BALB/c APA-knockout (KO) mice injected with a nephrotoxic serum showed persistent glomerular hyalinosis and albuminuria 96 hours after injection, whereas wild-type controls achieved virtually full recovery. We then tested the effect of 4-week infusion of AngII (400 ng/kg per minute) in APA-KO and wild-type mice. Although we observed no significant difference in achieved systolic BP, AngII-treated APA-KO mice developed a significant rise in albuminuria not observed in AngII-treated wild-type mice along with increased segmental and global sclerosis and/or collapse of juxtamedullary glomeruli, microcystic tubular dilation, and tubulointerstitial fibrosis. In parallel, AngII treatment significantly increased the kidney AngII content and attenuated the expression of podocyte nephrin in APA-KO mice but not in wild-type controls. These data show that deficiency of APA increases susceptibility to glomerular injury in BALB/c mice. The augmented AngII-mediated kidney injury observed in association with increased intrarenal AngII accumulation in the absence of APA suggests a protective metabolizing role of APA in AngII-mediated glomerular diseases. Copyright © 2017 by the American Society of Nephrology.

  5. The ClC-K2 Chloride Channel Is Critical for Salt Handling in the Distal Nephron.

    Science.gov (United States)

    Hennings, J Christopher; Andrini, Olga; Picard, Nicolas; Paulais, Marc; Huebner, Antje K; Cayuqueo, Irma Karen Lopez; Bignon, Yohan; Keck, Mathilde; Cornière, Nicolas; Böhm, David; Jentsch, Thomas J; Chambrey, Régine; Teulon, Jacques; Hübner, Christian A; Eladari, Dominique

    2017-01-01

    Chloride transport by the renal tubule is critical for blood pressure (BP), acid-base, and potassium homeostasis. Chloride uptake from the urinary fluid is mediated by various apical transporters, whereas basolateral chloride exit is thought to be mediated by ClC-Ka/K1 and ClC-Kb/K2, two chloride channels from the ClC family, or by KCl cotransporters from the SLC12 gene family. Nevertheless, the localization and role of ClC-K channels is not fully resolved. Because inactivating mutations in ClC-Kb/K2 cause Bartter syndrome, a disease that mimics the effects of the loop diuretic furosemide, ClC-Kb/K2 is assumed to have a critical role in salt handling by the thick ascending limb. To dissect the role of this channel in detail, we generated a mouse model with a targeted disruption of the murine ortholog ClC-K2. Mutant mice developed a Bartter syndrome phenotype, characterized by renal salt loss, marked hypokalemia, and metabolic alkalosis. Patch-clamp analysis of tubules isolated from knockout (KO) mice suggested that ClC-K2 is the main basolateral chloride channel in the thick ascending limb and in the aldosterone-sensitive distal nephron. Accordingly, ClC-K2 KO mice did not exhibit the natriuretic response to furosemide and exhibited a severely blunted response to thiazide. We conclude that ClC-Kb/K2 is critical for salt absorption not only by the thick ascending limb, but also by the distal convoluted tubule. Copyright © 2016 by the American Society of Nephrology.

  6. Changes in glomerular parietal epithelial cells in mouse kidneys with advanced age.

    Science.gov (United States)

    Roeder, Sebastian S; Stefanska, Ania; Eng, Diana G; Kaverina, Natalya; Sunseri, Maria W; McNicholas, Bairbre A; Rabinovitch, Peter; Engel, Felix B; Daniel, Christoph; Amann, Kerstin; Lichtnekert, Julia; Pippin, Jeffrey W; Shankland, Stuart J

    2015-07-15

    Kidney aging is accompanied by characteristic changes in the glomerulus, but little is known about the effect of aging on glomerular parietal epithelial cells (PECs), nor if the characteristic glomerular changes in humans and rats also occur in very old mice. Accordingly, a descriptive analysis was undertaken in 27-mo-old C57B6 mice, considered advanced age. PEC density was significantly lower in older mice compared with young mice (aged 3 mo), and the decrease was more pronounced in juxtamedullary glomeruli compared with outer cortical glomeruli. In addition to segmental and global glomerulosclerosis in older mice, staining for matrix proteins collagen type IV and heparan sulfate proteoglycan were markedly increased in Bowman's capsules of older mouse glomeruli, consistent with increased extracellular matrix production by PECs. De novo staining for CD44, a marker of activated and profibrotic PECs, was significantly increased in aged glomeruli. CD44 staining was more pronounced in the juxtamedullary region and colocalized with phosphorylated ERK. Additionally, a subset of aged PECs de novo expressed the epithelial-to-mesenchymal transition markers α-smooth muscle and vimentin, with no changes in epithelial-to-mesenchymal transition markers E-cadherin and β-catenin. The mural cell markers neural/glial antigen 2, PDGF receptor-β, and CD146 as well as Notch 3 were also substantially increased in aged PECs. These data show that mice can be used to better understand the aging kidney and that PECs undergo substantial changes, especially in juxtamedullary glomeruli, that may participate in the overall decline in glomerular structure and function with advancing age. Copyright © 2015 the American Physiological Society.

  7. Differential expression of the Kv1 voltage-gated potassium channel family in the rat nephron.

    Science.gov (United States)

    Carrisoza-Gaytán, Rolando; Salvador, Carolina; Diaz-Bello, Beatriz; Escobar, Laura I

    2014-10-01

    Several potassium (K(+)) channels contribute to maintaining the resting membrane potential of renal epithelial cells. Apart from buffering the cell membrane potential and cell volume, K(+) channels allow sodium reabsorption in the proximal tubule (PT), K(+) recycling and K(+) reabsorption in the thick ascending limb (TAL) and K(+) secretion and K(+) reabsorption in the distal convoluted tubule (DCT), connecting tubule (CNT) and collecting duct. Previously, we identified Kv.1.1, Kv1.3 and Kv1.6 channels in collecting ducts of the rat inner medulla. We also detected intracellular Kv1.3 channel in the acid secretory intercalated cells, which is trafficked to the apical membrane in response to dietary K(+) to function as a secretory K(+) channel. In this work we sought to characterize the expression of all members of the Kv1 family in the rat nephron. mRNA and protein expression were detected for all Kv1 channels. Immunoblots identified differential expression of each Kv1 in the cortex, outer and inner medulla. Immunofluorescence labeling detected Kv1.5 in Bowman´s capsule and endothelial cells and Kv1.7 in podocytes, endothelial cells and macula densa in glomeruli; Kv1.4, Kv1.5 and Kv1.7 in PT; Kv1.2, Kv1.4 and Kv1.6 in TAL; Kv1.1, Kv1.4 and Kv1.6 in DCT and CNT and Kv1.3 in DCT, and all the Kv1 family in the cortical and medullary collecting ducts. Recently, some hereditary renal syndromes have been attributed to mutations in K(+) channels. Our results expand the repertoire of K(+) channels that contribute to K(+) homeostasis to include the Kv1 family.

  8. Functional and morphologic damage in the neonatally irradiated canine kidney

    International Nuclear Information System (INIS)

    Peneyra, R.S.; Jaenke, R.S.

    1985-01-01

    Perinatal irradiation of the developing kidney results in progressive glomerulosclerosis (PGS) and renal failure. This syndrome may result from direct radiation damage to mature deep cortical nephrons and/or nephron functional adaptations resulting from outer cortical nephron ablation. Beagle dogs received single, whole-body exposures (330 R) to 60 Co gamma radiation at 4 days of age (IR4) to study the combined effects of direct radiation damage and nephron loss, or at 30 days of age (IR30) to study the effects of renal irradiation alone. To study the effects of nephron loss alone, dogs underwent unilateral nephrectomy (UN4) or superficial hyperthermic renal ablation (HY4) at 4 days of age. Nephron loss due to irradiation (IR4) and partial renal ablation (UN4 and HY4) was associated with compensatory nephron hypertrophy and increased single nephron glomerular filtration rate (SNGFR), while irradiation at 30 days resulted in transitory decreased SNGFR. Similar degrees of PGS occurred in IR4 dogs which experienced both irradiation and loss of nephrons and UN4 and HY4 dogs which experienced only loss of nephrons. PGS of lesser severity also occurred in IR30 dogs. These findings indicate that PGS associated with perinatal renal irradiation results from direct radiation damage to deep cortical nephrons and compensatory functional changes occurring in response to loss of renal mass

  9. Protein-energy malnutrition during early gestation in sheep blunts fetal renal vascular and nephron development and compromises adult renal function.

    Science.gov (United States)

    Lloyd, Louise J; Foster, Thomas; Rhodes, Phillip; Rhind, Stewart M; Gardner, David S

    2012-01-15

    A nutritionally poor maternal diet can reduce nephron endowment and pre-empt premature expression of markers for chronic renal disease in the offspring. A mechanistic pathway from variation in maternal diet through altered fetal renal development to compromised adult kidney structure and function with adult-onset obesity has not been described. We show that maternal protein-energy malnutrition in sheep blunts nephrogenic potential in the 0.44 gestation (65 days gestation, term ∼147 days) fetus by increasing apoptosis and decreasing angiogenesis in the nephrogenic zone, effects that were more marked in male fetuses. As adults, the low-protein-exposed sheep had reduced glomerular number and microvascular rarefaction in their kidneys compensated for, respectively, by glomerular hypertrophy and increased angiogenic support. In this study, the long-term mild anatomical deficits in the kidney would have remained asymptomatic in the lean state, but when superimposed on the broad metabolic challenge that obesity represents then microalbuminuria and blunted bilateral renal function revealed a long-term physiological compromise, that is only predicted to worsen with age. In conclusion, maternal protein-energy malnutrition specifically impacts fetal kidney vascular development and prevents full functionality of the adult kidney being achieved; these residual deficits are predicted to significantly increase the expected incidence of chronic kidney disease in prenatally undernourished individuals especially when coupled with a Western obesogenic environment.

  10. Sphingosine-1-Phosphate Evokes Unique Segment-Specific Vasoconstriction of the Renal Microvasculature

    Science.gov (United States)

    Singletary, Sean T.; Cook, Anthony K.; Hobbs, Janet L.; Pollock, Jennifer S.; Inscho, Edward W.

    2014-01-01

    Sphingosine-1-phosphate (S1P), a bioactive sphingolipid metabolite, has been implicated in regulating vascular tone and participating in chronic and acute kidney injury. However, little is known about the role of S1P in the renal microcirculation. Here, we directly assessed the vasoresponsiveness of preglomerular and postglomerular microvascular segments to exogenous S1P using the in vitro blood-perfused juxtamedullary nephron preparation. Superfusion of S1P (0.001–10 μM) evoked concentration-dependent vasoconstriction in preglomerular microvessels, predominantly afferent arterioles. After administration of 10 μM S1P, the diameter of afferent arterioles decreased to 35%±5% of the control diameter, whereas the diameters of interlobular and arcuate arteries declined to 50%±12% and 68%±6% of the control diameter, respectively. Notably, efferent arterioles did not respond to S1P. The S1P receptor agonists FTY720 and FTY720-phosphate and the specific S1P1 receptor agonist SEW2871 each evoked modest afferent arteriolar vasoconstriction. Conversely, S1P2 receptor inhibition with JTE-013 significantly attenuated S1P-mediated afferent arteriolar vasoconstriction. Moreover, blockade of L-type voltage-dependent calcium channels with diltiazem or nifedipine attenuated S1P-mediated vasoconstriction. Intravenous injection of S1P in anesthetized rats reduced renal blood flow dose dependently. Western blotting and immunofluorescence revealed S1P1 and S1P2 receptor expression in isolated preglomerular microvessels and microvascular smooth muscle cells. These data demonstrate that S1P evokes segmentally distinct preglomerular vasoconstriction via activation of S1P1 and/or S1P2 receptors, partially via L-type voltage-dependent calcium channels. Accordingly, S1P may have a novel function in regulating afferent arteriolar resistance under physiologic conditions. PMID:24578134

  11. Progressive Recruitment of Mesenchymal Progenitors Reveals a Time-Dependent Process of Cell Fate Acquisition in Mouse and Human Nephrogenesis.

    Science.gov (United States)

    Lindström, Nils O; De Sena Brandine, Guilherme; Tran, Tracy; Ransick, Andrew; Suh, Gio; Guo, Jinjin; Kim, Albert D; Parvez, Riana K; Ruffins, Seth W; Rutledge, Elisabeth A; Thornton, Matthew E; Grubbs, Brendan; McMahon, Jill A; Smith, Andrew D; McMahon, Andrew P

    2018-06-04

    Mammalian nephrons arise from a limited nephron progenitor pool through a reiterative inductive process extending over days (mouse) or weeks (human) of kidney development. Here, we present evidence that human nephron patterning reflects a time-dependent process of recruitment of mesenchymal progenitors into an epithelial nephron precursor. Progressive recruitment predicted from high-resolution image analysis and three-dimensional reconstruction of human nephrogenesis was confirmed through direct visualization and cell fate analysis of mouse kidney organ cultures. Single-cell RNA sequencing of the human nephrogenic niche provided molecular insights into these early patterning processes and predicted developmental trajectories adopted by nephron progenitor cells in forming segment-specific domains of the human nephron. The temporal-recruitment model for nephron polarity and patterning suggested by direct analysis of human kidney development provides a framework for integrating signaling pathways driving mammalian nephrogenesis. Copyright © 2018 Elsevier Inc. All rights reserved.

  12. Nephroprotective action of renin-angiotensin-aldosterone system blockade in chronic kidney disease patients: the landscape after ALTITUDE and VA NEPHRON-D trails.

    Science.gov (United States)

    Rutkowski, Boleslaw; Tylicki, Leszek

    2015-03-01

    The intervention in the renin-angiotensin-aldosterone system (RAAS) is currently the most effective strategy that combines blood pressure lowering and renoprotection. Several large, randomized, controlled trials evidenced the renoprotective potential of the angiotensin-converting enzyme inhibitors (ACEIs) and angiotensin II receptor blockers (ARBs) in nephropathies of almost any etiology. Mineralocorticoid receptor antagonists and direct renin inhibitor, aliskiren, as add-on treatments to standard therapy including the optimal dose of ACEIs or ARBs reduce albuminuria or proteinuria and slow development of renal dysfunction more than placebo. No clinical evidence is available however about whether these strategies may influence on long-term kidney outcome. Three recent trials suggested that aggressive RAAS blockade, that is, combination of 2 RAAS-blocking agents, does not decrease cardiovascular and renal morbidity and may carry an increased risk of serious complications. This article reviews an evidence-based approach on the use of RAAS-inhibiting agents in chronic kidney disease and considers the implementation of dual RAAS blockade with reference to the results of ALTITUDE and VA NEPHRON-D trails aiming to aid clinicians in their treatment decisions for patients with chronic kidney disease. Copyright © 2015 National Kidney Foundation, Inc. Published by Elsevier Inc. All rights reserved.

  13. Quantitative analysis of biological fluids by electron probe and X ray spectrometry

    International Nuclear Information System (INIS)

    Girod, Chantal

    1986-01-01

    In order to know the kidney normal operation and to have an insight on cellular transport mechanisms and hormonal regulations at the nephron level, a technique based on the use of an electron probe has been developed for the elemental analysis of micro-volumes of biological fluids. This academic document reports applications of this technique on animals on which such fluids have been sampled at different levels of the nephron. As these samples are available in too small volumes to be dosed by conventional methods, they have been quantitatively analysed by using an electronic probe based analyser in order to determine concentrations of all elements with an atomic number greater than that of carbon. After a presentation of the implemented method and hardware, the author thus describes how an analysis is performed, and reports and discusses an example (analysis conditions, data acquisition, data processing, minimum detectable concentration, reasons for measurement scattering)

  14. A study of nephron function in normal tropical residents using the creatinine and lithium clearances

    Science.gov (United States)

    Arthur, S. K.; Nyarko, A. K.; Asaku, J. Y.; Akyeampong, A. Y.

    The kidney bears the brunt of the demands of a tropical climate for water and electrolyte homeostasis. We hypothesised that a tropical climate may cause adaptive changes in the entire organism leading to altered renal function in our subjects. Hence renal function data for residents of a temperate climate may not be applic- able to tropical residents. We therefore sought to elucidate renal function in subjects residing in a tropical climate. We used lithium clearance, CLi, a non-invasive tool for assessing proximal tubular function in humans, and endogenous creatinine clearance, CCr, to estimate proximal tubular function and glomerular function, respectively, in our subjects. We did this in order to establish whether or not nephron function in our subjects differs from that for residents of a temperate climate. Nineteen male and 12 female Ghanaian subjects aged between 15 and 48 years were studied. The estimated GCr was 117.3+/-6.6 ml/min for male subjects and 97+/-6.4 ml/min for female subjects. CLi was 20.3+/-1.6 ml/min for male and 19.1+/-0.4 ml/min for female subjects, respectively. The estimated absolute reabsorption rate of fluid of proximal tubules was 97.0+/-6.0 ml/min for males and 78.1+/-6.0 ml/min for females. The percentage proximal fluid reabsorption for male and female subjects was 81.2+/-1.4 and 79.5+/-1.6, respectively. The differences between male and female values (mean+/-SEM) were not statistically significant. The data suggest that the proximal tubule in residents of a tropical climate may reabsorb more fluid compared to that in residents of a temperate climate. Our values for proximal tubular reabsorption are higher than those reported for residents of a temperature climate. Our estimate of glomerular filtration, however, is similar to published data for Caucasians. The difference in proximal tubular function may reflect possible renal adaptation to a hot, humid climate. We conclude that renal function of tropical residents differs from that of

  15. Chronic Kidney Disease and Exposure to Nephrotoxic Metals

    Science.gov (United States)

    Orr, Sarah E.; Bridges, Christy C.

    2017-01-01

    Chronic kidney disease (CKD) is a common progressive disease that is typically characterized by the permanent loss of functional nephrons. As injured nephrons become sclerotic and die, the remaining healthy nephrons undergo numerous structural, molecular, and functional changes in an attempt to compensate for the loss of diseased nephrons. These compensatory changes enable the kidney to maintain fluid and solute homeostasis until approximately 75% of nephrons are lost. As CKD continues to progress, glomerular filtration rate decreases, and remaining nephrons are unable to effectively eliminate metabolic wastes and environmental toxicants from the body. This inability may enhance mortality and/or morbidity of an individual. Environmental toxicants of particular concern are arsenic, cadmium, lead, and mercury. Since these metals are present throughout the environment and exposure to one or more of these metals is unavoidable, it is important that the way in which these metals are handled by target organs in normal and disease states is understood completely. PMID:28498320

  16. Morphological observations on the metanephros in the postnatal opossum, Didelphis virginiana.

    Science.gov (United States)

    Krause, W J; Cutts, J H; Leeson, C R

    1979-10-01

    The metanephros of the newborn opossum is very immature, consisting only of collecting tubules and a few immature nephrons. Development during the postnatal period can be divided into two distinct phases. The initial phase occurs during the first 60 days of postnatal life and is concerned with nephronogenesis and the differentiation of nephrons that have formed during this period. The second phase lasts through the remainder of the postnatal period and is concerned with further differentiation and growth of established nephrons. During this latter period the tubular portion of the nephron increases in length and the renal corpuscle increases in diameter. Ultrastructural observations suggest that metanephric nephrons are not functional during the first 4 days of postnatal life, while the mesonephros reaches the height of its development during this period: there may be some functional overlap between the mesonephros and metanephros during the latter part of the first week of postnatal life. The pattern of nephron induction and differentiation in the opossum is discussed.

  17. Multinephron dynamics on the renal vascular network

    DEFF Research Database (Denmark)

    Marsh, Donald J; Wexler, Anthony S; Brazhe, Alexey

    2012-01-01

    Tubuloglomerular feedback (TGF) and the myogenic mechanism combine in each nephron to regulate blood flow and glomerular filtration rate. Both mechanisms are non-linear, generate self-sustained oscillations, and interact as their signals converge on arteriolar smooth muscle, forming a regulatory...... clusters. In-phase synchronization predominated among nephrons separated by 1 or 3 vascular nodes, and anti-phase synchronization for 5 or 7 nodes of separation. Nephron dynamics were irregular and contained low frequency fluctuations. Results are consistent with simultaneous blood flow measurements...... of both mechanisms in the regulatory ensemble, to examine the effects of network structure on nephron synchronization. Symmetry, as a property of a network, facilitates synchronization. Nephrons received blood from a symmetric electrically conductive vascular tree. Symmetry was created by using identical...

  18. Do We Need to Clamp the Renal Hilum Liberally during the Initial Phase of the Learning Curve of Robot-Assisted Nephron-Sparing Surgery?

    Directory of Open Access Journals (Sweden)

    Ömer Acar

    2014-01-01

    Full Text Available Objective. We aimed to compare the results of our initial robot-assisted nephron-sparing surgeries (RANSS performed with or without hilar clamping. Material and Method. Charts of the initial RANSSs (n=44, which were performed by a single surgeon, were retrospectively reviewed. R.E.N.A.L. nephrometry system, modified Clavien classification, and M.D.R.D. equation were used to record tumoral complexity, complications, and estimated glomerular filtration rate (eGFR, respectively. Outcomes of the clamped (group 1, n=14 versus off-clamp (group 2, n=30 RANSSs were compared. Results. The difference between the two groups was insignificant regarding mean patient age, mean tumor size, and mean R.E.N.A.L. nephrometry score. Mean operative time, mean estimated blood loss amount, and mean length of hospitalization were similar between groups. A total of 4 patients in each group suffered 11 Clavien grade ≥2 complications early postoperatively. Open conversion rates were similar. The difference between the 2 groups in terms of the mean postoperative change in eGFR was insignificant. We did not encounter any local recurrence after a mean follow-up of 18.9 months. Conclusions. Creating warm-ischemic conditions during RANSS should not be a liberal decision, even in the initial phases of the learning curve for a highly experienced open surgeon.

  19. Role of RENAL nephrometry scoring system in planning surgical intervention in patients with localized renal mas

    OpenAIRE

    Mohamed Samir Shaaban; Tamer Mohammed Abou Youssif; Ahmed Mostafa; Hossam Eldin Hegazy; Mohammed Adel Atta

    2015-01-01

    Purpose: The study was designed to validate the value of preoperative planning using RENAL nephrometry scoring system in patients having organ confined renal tumors and undergoing surgical intervention and to assess its correlation with the surgical technique. Patient and methods: Forty patients with organ-confined renal masses underwent RENAL nephrometry scoring which was correlated with the surgical technique either radical or nephron-sparing surgery. Result: RENAL nephrometry scoring...

  20. Direct physical contact between intercalated cells in the distal convoluted tubule and the afferent arteriole in mouse kidneys.

    Directory of Open Access Journals (Sweden)

    Hao Ren

    Full Text Available Recent physiological studies in the kidney proposed the existence of a secondary feedback mechanism termed 'crosstalk' localized after the macula densa. This newly discovered crosstalk contact between the nephron tubule and its own afferent arteriole may potentially revolutionize our understanding of renal vascular resistance and electrolyte regulation. However, the nature of such a crosstalk mechanism is still debated due to a lack of direct and comprehensive morphological evidence. Its exact location along the nephron, its prevalence among the different types of nephrons, and the type of cells involved are yet unknown. To address these issues, computer assisted 3-dimensional nephron tracing was applied in combination with direct immunohistochemistry on plastic sections and electron microscopy. 'Random' contacts in the cortex were identified by the tracing and excluded. We investigated a total of 168 nephrons from all cortical regions. The results demonstrated that the crosstalk contact existed, and that it was only present in certain nephrons (90% of the short-looped and 75% of the long-looped nephrons. The crosstalk contacts always occurred at a specific position--the last 10% of the distal convoluted tubule. Importantly, we demonstrated, for the first time, that the cells found in the tubule wall at the contact site were always type nonA-nonB intercalated cells. In conclusion, the present work confirmed the existence of a post macula densa physical crosstalk contact.

  1. Direct physical contact between intercalated cells in the distal convoluted tubule and the afferent arteriole in mouse kidneys.

    Science.gov (United States)

    Ren, Hao; Liu, Ning-Yu; Andreasen, Arne; Thomsen, Jesper S; Cao, Liu; Christensen, Erik I; Zhai, Xiao-Yue

    2013-01-01

    Recent physiological studies in the kidney proposed the existence of a secondary feedback mechanism termed 'crosstalk' localized after the macula densa. This newly discovered crosstalk contact between the nephron tubule and its own afferent arteriole may potentially revolutionize our understanding of renal vascular resistance and electrolyte regulation. However, the nature of such a crosstalk mechanism is still debated due to a lack of direct and comprehensive morphological evidence. Its exact location along the nephron, its prevalence among the different types of nephrons, and the type of cells involved are yet unknown. To address these issues, computer assisted 3-dimensional nephron tracing was applied in combination with direct immunohistochemistry on plastic sections and electron microscopy. 'Random' contacts in the cortex were identified by the tracing and excluded. We investigated a total of 168 nephrons from all cortical regions. The results demonstrated that the crosstalk contact existed, and that it was only present in certain nephrons (90% of the short-looped and 75% of the long-looped nephrons). The crosstalk contacts always occurred at a specific position--the last 10% of the distal convoluted tubule. Importantly, we demonstrated, for the first time, that the cells found in the tubule wall at the contact site were always type nonA-nonB intercalated cells. In conclusion, the present work confirmed the existence of a post macula densa physical crosstalk contact.

  2. Dual regulation of the native ClC-K2 chloride channel in the distal nephron by voltage and pH.

    Science.gov (United States)

    Pinelli, Laurent; Nissant, Antoine; Edwards, Aurélie; Lourdel, Stéphane; Teulon, Jacques; Paulais, Marc

    2016-09-01

    ClC-K2, a member of the ClC family of Cl(-) channels and transporters, forms the major basolateral Cl(-) conductance in distal nephron epithelial cells and therefore plays a central role in renal Cl(-) absorption. However, its regulation remains largely unknown because of the fact that recombinant ClC-K2 has not yet been studied at the single-channel level. In the present study, we investigate the effects of voltage, pH, Cl(-), and Ca(2+) on native ClC-K2 in the basolateral membrane of intercalated cells from the mouse connecting tubule. The ∼10-pS channel shows a steep voltage dependence such that channel activity increases with membrane depolarization. Intracellular pH (pHi) and extracellular pH (pHo) differentially modulate the voltage dependence curve: alkaline pHi flattens the curve by causing an increase in activity at negative voltages, whereas alkaline pHo shifts the curve toward negative voltages. In addition, pHi, pHo, and extracellular Ca(2+) strongly increase activity, mainly because of an increase in the number of active channels with a comparatively minor effect on channel open probability. Furthermore, voltage alters both the number of active channels and their open probability, whereas intracellular Cl(-) has little influence. We propose that changes in the number of active channels correspond to them entering or leaving an inactivated state, whereas modulation of open probability corresponds to common gating by these channels. We suggest that pH, through the combined effects of pHi and pHo on ClC-K2, might be a key regulator of NaCl absorption and Cl(-)/HCO3 (-) exchange in type B intercalated cells. © 2016 Pinelli et al.

  3. Frequency encoding in renal blood flow regulation

    DEFF Research Database (Denmark)

    Marsh, D.J.; Sosnovtseva, Olga; Pavlov, A.N.

    2005-01-01

    With a model of renal blood flow regulation, we examined consequences of tubuloglomerular feedback (TGF) coupling to the myogenic mechanism via voltage-gated Ca channels. The model reproduces the characteristic oscillations of the two mechanisms and predicts frequency and amplitude modulation...... of the myogenic oscillation by TGF. Analysis by wavelet transforms of single-nephron blood flow confirms that both amplitude and frequency of the myogenic oscillation are modulated by TGF. We developed a double-wavelet transform technique to estimate modulation frequency. Median value of the ratio of modulation...... TGF cycle to the next. We used a blood pressure signal recorded by telemetry from a conscious rat as the input to the model. Blood pressure fluctuations induced variability in the modulation records similar to those found in the nephron blood flow results. Frequency and amplitude modulation can...

  4. The ureteric bud epithelium: morphogenesis and roles in metanephric kidney patterning.

    Science.gov (United States)

    Nagalakshmi, Vidya K; Yu, Jing

    2015-03-01

    The mammalian metanephric kidney is composed of two epithelial components, the collecting duct system and the nephron epithelium, that differentiate from two different tissues -the ureteric bud epithelium and the nephron progenitors, respectively-of intermediate mesoderm origin. The collecting duct system is generated through reiterative ureteric bud branching morphogenesis, whereas the nephron epithelium is formed in a process termed nephrogenesis, which is initiated with the mesenchymal-epithelial transition of the nephron progenitors. Ureteric bud branching morphogenesis is regulated by nephron progenitors, and in return, the ureteric bud epithelium regulates nephrogenesis. The metanephric kidney is physiologically divided along the corticomedullary axis into subcompartments that are enriched with specific segments of these two epithelial structures. Here, we provide an overview of the major molecular and cellular processes underlying the morphogenesis and patterning of the ureteric bud epithelium and its roles in the cortico-medullary patterning of the metanephric kidney. © 2015 Wiley Periodicals, Inc.

  5. The effect of zero-ischaemia laparoscopic minimally invasive partial nephrectomy using the modified sequential preplaced suture renorrhaphy technique on long-term renal functions.

    Science.gov (United States)

    Sönmez, Mehmet Giray; Kara, Cengiz

    2017-09-01

    Laparoscopic minimally invasive partial nephrectomy (MIPN) is the preferred technique in renal surgery, especially T1 phase kidney tumours, and it is recommended for the protection of renal functions in methods that do not involve ischaemia. To evaluate long-term renal functions of zero-ischaemia laparoscopic MIPN patients who underwent a modified sequential preplaced suture renorrhaphy technique. In a total of 17 renal units in 16 patients with kidney tumours that were determined incidentally and did not cause any complaints, the masses were extracted via laparoscopic partial nephrectomy (LPN) using the modified sequential preplaced suture renorrhaphy technique. Creatinine and estimated glomerular filtration rate (eGFR) values of the patients were measured preoperatively and on the first day and after 12 months postoperatively, and the results were compared. The differences between the pre- and postoperative values were statistically significant (p = 0.033, p = 0.045), but the changes in postoperative creatinine and eGFR values were clinically insignificant. While the differences between preoperative and first-day postoperative creatinine and eGFR values were found to be statistically significant (p = 0.039, p = 0.042, respectively), a statistically significant difference was not detected between preoperative and 12-month postoperative creatinine and eGFR values (p = 0.09, p = 0.065, respectively). The global percentage of functional recovery was measured as 92.5% on the first day and 95.9% at the 12 th month. The modified sequential preplaced suture renorrhaphy technique is an effective, reliable method for avoiding complications and preserving renal functions and nephrons in appropriate patients.

  6. Prostaglandin-E2 Mediated Increase in Calcium and Phosphate Excretion in a Mouse Model of Distal Nephron Salt Wasting.

    Directory of Open Access Journals (Sweden)

    Manoocher Soleimani

    Full Text Available Contribution of salt wasting and volume depletion to the pathogenesis of hypercalciuria and hyperphosphaturia is poorly understood. Pendrin/NCC double KO (pendrin/NCC-dKO mice display severe salt wasting under basal conditions and develop profound volume depletion, prerenal renal failure, and metabolic alkalosis and are growth retarded. Microscopic examination of the kidneys of pendrin/NCC-dKO mice revealed the presence of calcium phosphate deposits in the medullary collecting ducts, along with increased urinary calcium and phosphate excretion. Confirmatory studies revealed decreases in the expression levels of sodium phosphate transporter-2 isoforms a and c, increases in the expression of cytochrome p450 family 4a isotypes 12 a and b, as well as prostaglandin E synthase 1, and cyclooxygenases 1 and 2. Pendrin/NCC-dKO animals also had a significant increase in urinary prostaglandin E2 (PGE-2 and renal content of 20-hydroxyeicosatetraenoic acid (20-HETE levels. Pendrin/NCC-dKO animals exhibit reduced expression levels of the sodium/potassium/2chloride co-transporter 2 (NKCC2 in their medullary thick ascending limb. Further assessment of the renal expression of NKCC2 isoforms by quantitative real time PCR (qRT-PCR reveled that compared to WT mice, the expression of NKCC2 isotype F was significantly reduced in pendrin/NCC-dKO mice. Provision of a high salt diet to rectify volume depletion or inhibition of PGE-2 synthesis by indomethacin, but not inhibition of 20-HETE generation by HET0016, significantly improved hypercalciuria and salt wasting in pendrin/NCC dKO mice. Both high salt diet and indomethacin treatment also corrected the alterations in NKCC2 isotype expression in pendrin/NCC-dKO mice. We propose that severe salt wasting and volume depletion, irrespective of the primary originating nephron segment, can secondarily impair the reabsorption of salt and calcium in the thick ascending limb of Henle and/or proximal tubule, and reabsorption of

  7. Estimation of Total Glomerular Number Using an Integrated Disector Method in Embryonic and Postnatal Kidneys

    Directory of Open Access Journals (Sweden)

    Michel G Arsenault

    2014-06-01

    Full Text Available Congenital Anomalies of the Kidney and Urinary Tract (CAKUT are a polymorphic group of clinical disorders comprising the major cause of renal failure in children. Included within CAKUT is a wide spectrum of developmental malformations ranging from renal agenesis, renal hypoplasia and renal dysplasia (maldifferentiation of renal tissue, each characterized by varying deficits in nephron number. First presented in the Brenner Hypothesis, low congenital nephron endowment is becoming recognized as an antecedent cause of adult-onset hypertension, a leading cause of coronary heart disease, stroke, and renal failure in North America. Genetic mouse models of impaired nephrogenesis and nephron endowment provide a critical framework for understanding the origins of human kidney disease. Current methods to quantitate nephron number include (i acid maceration (ii estimation of nephron number from a small number of tissue sections (iii imaging modalities such as MRI and (iv the gold standard physical disector/fractionator method. Despite its accuracy, the physical disector/fractionator method is rarely employed because it is labour-intensive, time-consuming and costly to perform. Consequently, less rigourous methods of nephron estimation are routinely employed by many laboratories. Here we present an updated, digitized version of the physical disector/fractionator method using free open source Fiji software, which we have termed the integrated disector method. This updated version of the gold standard modality accurately, rapidly and cost-effectively quantitates nephron number in embryonic and post-natal mouse kidneys, and can be easily adapted for stereological measurements in other organ systems.

  8. Evidence of In Vitro Preservation of Human Nephrogenesis at the Single-Cell Level

    Directory of Open Access Journals (Sweden)

    Naomi Pode-Shakked

    2017-07-01

    Full Text Available During nephrogenesis, stem/progenitor cells differentiate and give rise to early nephron structures that segment to proximal and distal nephron cell types. Previously, we prospectively isolated progenitors from human fetal kidney (hFK utilizing a combination of surface markers. However, upon culture nephron progenitors differentiated and could not be robustly maintained in vitro. Here, by culturing hFK in a modified medium used for in vitro growth of mouse nephron progenitors, and by dissection of NCAM+/CD133− progenitor cells according to EpCAM expression (NCAM+/CD133−/EpCAM−, NCAM+/CD133−/EpCAMdim, NCAM+/CD133−/EpCAMbright, we show at single-cell resolution a preservation of uninduced and induced cap mesenchyme as well as a transitioning mesenchymal-epithelial state. Concomitantly, differentiating and differentiated epithelial lineages are also maintained. In vitro expansion of discrete stages of early human nephrogenesis in nephron stem cell cultures may be used for drug screening on a full repertoire of developing kidney cells and for prospective isolation of mesenchymal or epithelial renal lineages for regenerative medicine.

  9. Differential expression of T- and L-type voltage-dependent calcium channels in renal resistance vessels

    DEFF Research Database (Denmark)

    Hansen, Pernille B. Lærkegaard; Jensen, Boye L.; Andreasen, D

    2001-01-01

    The distribution of voltage-dependent calcium channels in kidney pre- and postglomerular resistance vessels was determined at the molecular and functional levels. Reverse transcription-polymerase chain reaction analysis of microdissected rat preglomerular vessels and cultured smooth muscle cells...... on vascular diameter in the afferent arteriole. We conclude that voltage-dependent L- and T-type calcium channels are expressed and of functional significance in renal cortical preglomerular vessels, in juxtamedullary efferent arterioles, and in outer medullary vasa recta, but not in cortical efferent...

  10. Chaos and non-linear phenomena in renal vascular control

    DEFF Research Database (Denmark)

    Yip, K P; Holstein-Rathlou, N H

    1996-01-01

    are an example of deterministic chaos. Experimental studies show that the development of hypertension is associated with an increase in strength of the interaction between nephrons. Mathematical models suggest that an increased nephron-nephron interaction could cause a bifurcation in the dynamics of TGF from...... periodic oscillations to deterministic chaos. In addition to the TGF mediated oscillation, experimental studies have also demonstrated the presence of a faster oscillation, this having a frequency of 120-160 mHz. This is caused by a mechanism intrinsic to the vascular wall, and presumably represents...

  11. Synchronization among Mechanisms of Renal Autoregulation is Reduced in Hypertensive Rats

    DEFF Research Database (Denmark)

    Sosnovtseva, Olga; Pavlov, A. N.; Mosekilde, Erik

    2007-01-01

    , and a slower (20-40 mHz) oscillation in tubuloglomerular feedback (TGF). These mechanisms interact; the TGF mode modulates both the amplitude and the frequency of the myogenic mode. Nephrons also communicate with each other using vascular signals triggered by membrane events in arteriolar smooth muscle cells...... in SHR is a state of partial synchronization with entrainment between neighboring nephrons for only one of the modes. Modulation of the myogenic mode by the TGF mode is much stronger in hypertensive than in normotensive rats. Synchronization among nephrons forms the basis for an integrated reaction...

  12. Carbonic anhydrase expression in kidney and renal cancer: implications for diagnosis and treatment

    NARCIS (Netherlands)

    Oosterwijk, E.

    2014-01-01

    Four different carbonic anhydrases are expressed in the human nephron, the functional unit of the kidney. These are specifically expressed in different nephron segments, emphasizing the critical role carbonic anhydrases play in maintaining the homeostasis of this crucial organ.Whereas the

  13. Trends in the use of of nephron-sparing surgery (NSS) at an Australian tertiary referral centre: an analysis of surgical decision-making using the R.E.N.A.L. nephrometry scoring system.

    Science.gov (United States)

    Satasivam, Prassannah; Rajarubendra, Nieroshan; Chia, Ping Han; Munshey, Aasheen; Sengupta, Shomik; Bolton, Damien

    2012-05-01

    Study Type--Therapy (case series). Level of Evidence 4. What's known on the subject? And what does the study add? Nephron-sparing surgery (NSS) is increasingly recognised as a preferred form of management for the incidentally detected small renal mass (SRM). Within the context of equivalent oncological outcomes, patients treated by NSS may have a survival advantage over those treated by radical nephrectomy (RN) through a reduced risk of chronic kidney disease and its associated cardiac morbidity. Despite this, according to Medicare data from the USA, a disproportionate number of patients with SRMs continue to be treated with RN instead of NSS. Similar data from Australia are not yet available. The present study explores the evolving management of SRMs at an Australian tertiary centre over a 5-year period. It utilises the R.E.N.A.L. Nephrometry Score to assess how lesion complexity has influenced surgical decision-making and charts the increasing use of NSS in the management of low-complexity renal masses at our centre. • To examine recent trends in the use of nephron-sparing surgery (NSS) at our centre. Specifically, we sought to examine the process of surgical decision-making by applying the R.E.N.A.L. nephrometry scoring system to assess the complexity of lesions for which surgery was undertaken. • We performed a retrospective review of renal masses treated by surgery from January 2005 to December 2009, including 79 RN and 70 NSS. • CT images were available for analysis in 50 patients within each group. • Lesions were scored on the basis of their complexity using the R.E.N.A.L. nephrometry scoring system developed by Kutikov and Uzzo. • There was no difference in age between patients undergoing RN and NSS (median age 61 vs 60 years). • RN was performed for significantly larger lesions (mean [sd] 68 [9] vs 29 [2] mm, P NSS was primarily used for low-complexity lesions, but included four (8%) moderate-complexity lesions in the final 2 years of the study

  14. Nephron-sparing percutaneous ablation of a 5 cm renal cell carcinoma by superselective embolization and percutaneous RF-ablation

    Energy Technology Data Exchange (ETDEWEB)

    Tacke, J.; Mahnken, A.; Buecker, A.; Guenther, R.W. [Technische Hochschule Aachen (Germany). Klinik fuer Radiologische Diagnostik; Rohde, D. [Technische Hochschule Aachen (Germany). Abt. Urologie

    2001-11-01

    Purpose: To report on the nephron-sparing, percutaneous ablation of a large renal cell carcinoma by combined superselective embolization and percutaneous radiofrequency ablation. Materials and Methods: A 5 cm renal cell carcinoma of a 43-year-old drug abusing male with serologically proven HIV, hepatitis B and C infection, who refused surgery, was superselectively embolized using microspheres (size: 500 - 700 {mu}m) and a platinum coil under local anesthesia. Percutaneous radiofrequency ablation using a 7F LeVeen probe (size of expanded probe tip: 40 mm) and a 200 Watt generator was performed one day after transcatheter embolization under general anesthesia. Results: The combined treatment resulted in complete destruction of the tumor without relevant damage of the surrounding healthy renal tissue. The patient was discharged 24 hours after RF ablation. No complications like urinary leaks or fistulas were observed and follow up CT one day and 4 weeks after the radiofrequency intervention revealed no signs of residual tumor growth. Conclusion: The combined transcatheter embolization and percutaneous radiofrequency ablation of renal cell carcinoma has proved technically feasible, effective, and safe in this patient. It may be offered as an alternative treatment to partial or radical nephrectomy under certain circumstances. Abbreviations: RF = radiofrequency ablation; CT = computed tomography; HIV = human immunodeficiency virus. (orig.) [German] Ziel: Bericht ueber eine nierenschonende, perkutane Ablation eines 5 cm grossen Nierenzellkarzinoms durch kombinierte Transkatheterembolisation und perkutane Radiofrequenzablation. Material und Methoden: Ein 5 cm grosses Nierenzellkarzinom eines 43 Jahre alten Drogenabhaengigen mit serologisch nachgewiesener HIV, Hepatitis B- und C-Infektion, der eine operative Therapie ablehnte, wurde superselektiv durch Embosphaeren (Partikelgroesse: 500 - 700 {mu}m) und einer Platinspirale unter Lokalanaesthesie embolisiert. Am Folgetag

  15. 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

    CT) data we develop an algorithm for generating the renal arterial network. We then introduce a mathematical model describing blood flow dynamics and nephron to nephron interaction in the network. The model includes an implementation of electrical signal propagation along a vascular wall. Simulation...

  16. Analysis of interaction between TGF and the myogenic response in renal blood flow autoregulation

    DEFF Research Database (Denmark)

    Feldberg, R; Colding-Jørgensen, M; Holstein-Rathlou, N H

    1995-01-01

    . The contribution of TGF to smooth muscle activity is assumed to be a linear function of the glomerular capillary pressure. The results show that the myogenic response plays an important role in renal blood flow autoregulation. Without a myogenic response, mechanisms such as TGF that are localized in the distal......The present study investigates the interaction between the tubuloglomerular feedback (TGF) response and the myogenic mechanism by use of a mathematical model. The two control mechanisms are implemented in a spatially distributed model of the rat renal juxtamedullary afferent arteriole. The model...

  17. Expression of Nek1 during kidney development and cyst formation in multiple nephron segments in the Nek1-deficient kat2J mouse model of polycystic kidney disease.

    Science.gov (United States)

    Chen, Yumay; Chiang, Huai-Chin; Litchfield, Patricia; Pena, Michelle; Juang, Charity; Riley, Daniel J

    2014-07-17

    Neks, mammalian orthologs of the fungal protein kinase never-in-mitosis A, have been implicated in the pathogenesis of polycystic kidney disease. Among them, Nek1 is the primary protein inactivated in kat2J mouse models of PKD. We report the expression pattern of Nek1 and characterize the renal cysts that develop in kat2J mice. Nek1 is detectable in all murine tissues but its expression in wild type and kat2J heterozygous kidneys decrease as the kidneys mature, especially in tubular epithelial cells. In the embryonic kidney, Nek1 expression is most prominent in cells that will become podocytes and proximal tubules. Kidney development in kat2J homozygous mice is aberrant early, before the appearance of gross cysts: developing cortical zones are thin, populated by immature glomeruli, and characterized by excessive apoptosis of several cell types. Cysts in kat2J homozygous mice form postnatally in Bowman's space as well as different tubular subtypes. Late in life, kat2J heterozygous mice form renal cysts and the cells lining these cysts lack staining for Nek1. The primary cilia of cells lining cysts in kat2J homozygous mice are morphologically diverse: in some cells they are unusually long and in others there are multiple cilia of varying lengths. Our studies indicate that Nek1 deficiency leads to disordered kidney maturation, and cysts throughout the nephron.

  18. New percutaneous ablative modalities in nephron-sparing surgery of small renal tumors

    Science.gov (United States)

    de Riese, Werner T. W.; Nelius, Thomas; Aronoff, David R.; Mittemeyer, Bernhard T.

    2004-07-01

    Renal tumors are increasingly detected on abdominal imaging studies. Standard treatment of small renal tumors includes partial or radical nephrectomy, done either open or laparoscopically. Several in situ ablative techniques to treat small renal lesions are currently in various phases of evolution. All involve imparting destructive energy to the tumor while minimizing injury to adjacent normal tissue. Cryotherapy (CryoT), radiofrequency ablation (RFA), high-intensity focused ultrasound (HIFUS) and high-intensity radiation (HIR) are all being evaluated as tools to ablate renal tumors. The goal with these modalities is to minimize the blood loss, tissue manipulation, and morbidity associated with excisional approaches. Animal studies have shown that large, reproducible lesions can be ablated in normal kidney tissue by these new techniques. Studies of human renal tissue response to RFA are just beginning. Ex vivo studies reveal large, reproducible controlled lesions in normal renal tissue, similar to animal studies. In vivo studies have shown no significant toxicity, while efficacy is currently under evaluation. Preliminary clinical studies in humans have revealed that renal tumors are slow to regress after treatment, but about 75% of these small renal tumors appeared well treated. Mixed responses have been observed in the remaining cases. This paper presents a concise review of efficacy, advantages and disadvantages of these new minimal invasive techniques and their possible clinical implication in the future.

  19. The testicular sperm ducts and genital kidney of male Ambystoma maculatum (Amphibia, Urodela, Ambystomatidae).

    Science.gov (United States)

    Siegel, Dustin S; Aldridge, Robert D; Rheubert, Justin L; Gribbins, Kevin M; Sever, David M; Trauth, Stanley E

    2013-03-01

    The ducts associated with sperm transport from the testicular lobules to the Wolffian ducts in Ambystoma maculatum were examined with transmission electron microscopy. Based on the ultrastructure and historical precedence, new terminology for this network of ducts is proposed that better represents primary hypotheses of homology. Furthermore, the terminology proposed better characterizes the distinct regions of the sperm transport ducts in salamanders based on anatomy and should, therefore, lead to more accurate comparisons in the future. While developing the above ontology, we also tested the hypothesis that nephrons from the genital kidney are modified from those of the pelvic kidney due to the fact that the former nephrons function in sperm transport. Our ultrastructural analysis of the genital kidney supports this hypothesis, as the basal plasma membrane of distinct functional regions of the nephron (proximal convoluted tubule, distal convoluted tubule, and collecting tubule) appear less folded (indicating decreased surface area and reduced reabsorption efficiency) and the proximal convoluted tubule possesses ciliated epithelial cells along its entire length. Furthermore, visible luminal filtrate is absent from the nephrons of the genital kidney throughout their entire length. Thus, it appears that the nephrons of the genital kidney have reduced reabsorptive capacity and ciliated cells of the proximal convoluted tubule may increase the movement of immature sperm through the sperm transport ducts or aid in the mixing of seminal fluids within the ducts. Copyright © 2012 Wiley Periodicals, Inc.

  20. Developmental Origins of Chronic Renal Disease: An Integrative Hypothesis

    Directory of Open Access Journals (Sweden)

    F. Boubred

    2013-01-01

    Full Text Available Cardiovascular diseases are one of the leading causes of mortality. Hypertension (HT is one of the principal risk factors associated with death. Chronic kidney disease (CKD, which is probably underestimated, increases the risk and the severity of adverse cardiovascular events. It is now recognized that low birth weight is a risk factor for these diseases, and this relationship is amplified by a rapid catch-up growth or overfeeding during infancy or childhood. The pathophysiological and molecular mechanisms involved in the “early programming” of CKD are multiple and partially understood. It has been proposed that the developmental programming of arterial hypertension and chronic kidney disease is related to a reduced nephron endowment. However, this mechanism is still discussed. This review discusses the complex relationship between birth weight and nephron endowment and how early growth and nutrition influence long term HT and CKD. We hypothesize that fetal environment reduces moderately the nephron number which appears insufficient by itself to induce long term diseases. Reduced nephron number constitutes a “factor of vulnerability” when additional factors, in particular a rapid postnatal growth or overfeeding, promote the early onset of diseases through a complex combination of various pathophysiological pathways.

  1. Tc-99m Hydroxymethylene Diphosphonate (HMDP) Renal Uptake as a Surrogate Marker of Postoperative Impairment of the Glomerular Filtration Rate in Renal Tumor Patients Following Nephron-Sparing Surgery.

    Science.gov (United States)

    Choi, Hongyoon; Lee, Won Woo; So, Young; Ha, Seunggyun; Byun, Seok-Soo; Kim, Sang Eun

    2014-12-01

    We investigated Tc-99m hydroxymethylene diphosphonate (HMDP) scintigraphy findings in renal tumor patients from the perspective of postoperative renal dysfunction following nephron-sparing surgery (NSS). Forty-three renal tumor patients (M:F = 28:15, age 53.9 ± 12.5 years) who had undergone Tc-99m HMDP scintigraphy after NSS were enrolled. The patients were divided into HMDP(+) or HMDP(-) groups by visual assessment, and the asymmetric index (ASI) was calculated using a region-of-interest analysis. In 16 patients, the total and split glomerular filtration rate (GFR) was assessed using Tc-99m diethylenetriaminepentaacetic acid (DTPA) scintigraphy at baseline and at 3 and 6 months post-NSS. High Tc-99m HMDP uptake was observed in the operated kidneys, but this did not persist later than 7 days post-NSS. Split GFR of the operated kidneys at baseline (58.5 ± 9.3 ml/min) was significantly reduced at 6 months post-NSS (40.1 ± 5.9 ml/min, p Tc-99m HMDP. Declines in both total GFR (p = 0.010 and p = 0.002 for 3 and 6 months, respectively) and split GFR of the operated kidneys (p Tc-99m HMDP in the operated kidneys. The ASI was negatively correlated with %change in the split GFR of these operated kidneys at 6 months post-NSS (rho =-0.578, p = 0.0304). Tc-99m HMDP uptake within 1 week following NSS is a surrogate marker of GFR impairment over 6 months post-NSS.

  2. Evolutionary Nephrology.

    Science.gov (United States)

    Chevalier, Robert L

    2017-05-01

    Progressive kidney disease follows nephron loss, hyperfiltration, and incomplete repair, a process described as "maladaptive." In the past 20 years, a new discipline has emerged that expands research horizons: evolutionary medicine. In contrast to physiologic (homeostatic) adaptation, evolutionary adaptation is the result of reproductive success that reflects natural selection. Evolutionary explanations for physiologically maladaptive responses can emerge from mismatch of the phenotype with environment or evolutionary tradeoffs. Evolutionary adaptation to a terrestrial environment resulted in a vulnerable energy-consuming renal tubule and a hypoxic, hyperosmolar microenvironment. Natural selection favors successful energy investment strategy: energy is allocated to maintenance of nephron integrity through reproductive years, but this declines with increasing senescence after ~40 years of age. Risk factors for chronic kidney disease include restricted fetal growth or preterm birth (life history tradeoff resulting in fewer nephrons), evolutionary selection for APOL1 mutations (that provide resistance to trypanosome infection, a tradeoff), and modern life experience (Western diet mismatch leading to diabetes and hypertension). Current advances in genomics, epigenetics, and developmental biology have revealed proximate causes of kidney disease, but attempts to slow kidney disease remain elusive. Evolutionary medicine provides a complementary approach by addressing ultimate causes of kidney disease. Marked variation in nephron number at birth, nephron heterogeneity, and changing susceptibility to kidney injury throughout life history are the result of evolutionary processes. Combined application of molecular genetics, evolutionary developmental biology (evo-devo), developmental programming and life history theory may yield new strategies for prevention and treatment of chronic kidney disease.

  3. Evolutionary Nephrology

    Directory of Open Access Journals (Sweden)

    Robert L. Chevalier

    2017-05-01

    Full Text Available Progressive kidney disease follows nephron loss, hyperfiltration, and incomplete repair, a process described as “maladaptive.” In the past 20 years, a new discipline has emerged that expands research horizons: evolutionary medicine. In contrast to physiologic (homeostatic adaptation, evolutionary adaptation is the result of reproductive success that reflects natural selection. Evolutionary explanations for physiologically maladaptive responses can emerge from mismatch of the phenotype with environment or from evolutionary tradeoffs. Evolutionary adaptation to a terrestrial environment resulted in a vulnerable energy-consuming renal tubule and a hypoxic, hyperosmolar microenvironment. Natural selection favors successful energy investment strategy: energy is allocated to maintenance of nephron integrity through reproductive years, but this declines with increasing senescence after ∼40 years of age. Risk factors for chronic kidney disease include restricted fetal growth or preterm birth (life history tradeoff resulting in fewer nephrons, evolutionary selection for APOL1 mutations (which provide resistance to trypanosome infection, a tradeoff, and modern life experience (Western diet mismatch leading to diabetes and hypertension. Current advances in genomics, epigenetics, and developmental biology have revealed proximate causes of kidney disease, but attempts to slow kidney disease remain elusive. Evolutionary medicine provides a complementary approach by addressing ultimate causes of kidney disease. Marked variation in nephron number at birth, nephron heterogeneity, and changing susceptibility to kidney injury throughout the life history are the result of evolutionary processes. Combined application of molecular genetics, evolutionary developmental biology (evo-devo, developmental programming, and life history theory may yield new strategies for prevention and treatment of chronic kidney disease.

  4. Role of pressure in angiotensin II-induced renal injury: chronic servo-control of renal perfusion pressure in rats.

    Science.gov (United States)

    Mori, Takefumi; Cowley, Allen W

    2004-04-01

    Renal perfusion pressure was servo-controlled chronically in rats to quantify the relative contribution of elevated arterial pressure versus angiotensin II (Ang II) on the induction of renal injury in Ang II-induced hypertension. Sprague-Dawley rats fed a 4% salt diet were administered Ang II for 14 days (25 ng/kg per minute IV; saline only for sham rats), and the renal perfusion pressure to the left kidney was continuously servo-controlled to maintain a normal pressure in that kidney throughout the period of hypertension. An aortic occluder was implanted around the aorta between the two renal arteries and carotid and femoral arterial pressure were measured continuously throughout the experiment to determine uncontrolled and controlled renal perfusion pressure, respectively. Renal perfusion pressure of uncontrolled, controlled, and sham kidneys over the period of Ang II or saline infusion averaged 152.6+/-7.0, 117.4+/-3.5, and 110.7+/-2.2 mm Hg, respectively. The high-pressure uncontrolled kidneys exhibited tubular necrosis and interstitial fibrosis, especially prominent in the outer medullary region. Regional glomerular sclerosis and interlobular artery injury were also pronounced. Controlled kidneys were significantly protected from interlobular artery injury, juxtamedullary glomeruli injury, tubular necrosis, and interstitial fibrosis as determined by comparing the level of injury. Glomerular injury was not prevented in the outer cortex. Transforming growth factor (TGF)-beta and active NF-kappaB proteins determined by immunohistochemistry were colocalized in the uncontrolled kidney in regions of interstitial fibrosis. We conclude that the preferential juxtamedullary injury found in Ang II hypertension is largely induced by pressure and is probably mediated through the TGF-beta and NF-kappaB pathway.

  5. Reduced Abd-B Hox function during kidney development results in lineage infidelity.

    Science.gov (United States)

    Magella, Bliss; Mahoney, Robert; Adam, Mike; Potter, S Steven

    2018-06-15

    Hox genes can function as key drivers of segment identity, with Hox mutations in Drosophila often resulting in dramatic homeotic transformations. In addition, however, they can serve other essential functions. In mammals, the study of Hox gene roles in development is complicated by the presence of four Hox clusters with a total of 39 genes showing extensive functional overlap. In this study, in order to better understand shared core Hox functions, we examined kidney development in mice with frameshift mutations of multiple Abd-B type Hox genes. The resulting phenotypes included dramatically reduced branching morphogenesis of the ureteric bud, premature depletion of nephron progenitors and abnormal development of the stromal compartment. Most unexpected, however, we also observed a cellular level lineage infidelity in nephron segments. Scattered cells within the proximal tubules, for example, expressed genes normally expressed only in collecting ducts. Multiple combinations of inappropriate nephron segment specific marker expression were found. In some cases, cells within a tubule showed incorrect identity, while in other cases cells showed ambiguous character, with simultaneous expression of genes associated with more than one nephron segment. These results give evidence that Hox genes have an overlapping core function at the cellular level in driving and/or maintaining correct differentiation decisions. Copyright © 2018 Elsevier Inc. All rights reserved.

  6. High Glucose Concentration Stimulates NHE-1 Activity in Distal Nephron Cells: the Role of the Mek/Erk1/2/p90RSK and p38MAPK Signaling Pathways

    Directory of Open Access Journals (Sweden)

    Juliana Martins da Costa-Pessoa

    2014-02-01

    Full Text Available Aims: In models of diabetes, distal nephron cells contribute to glucose uptake and oxidation. How these cells contribute to the use of glucose for the regulation of H+ extrusion remains unknown. We used Madin-Darby Canine Kidney (MDCK cells to investigate the effect of acute or chronic high glucose concentration on the abundance and activity of the Na+/H+ exchanger (NHE-1. Methods: Using RT-PCR, we also evaluated the mRNA expression for sodium glucose co-transporters SGLT1 and SGLT2. Protein abundance was analyzed using immunoblotting, and intracellular pH (pHi recovery was evaluated using microscopy in conjunction with the fluorescent probe BCECF/AM. The Na+-dependent pHi recovery rate was monitored with HOE-694 (50 µM and/or S3226 (10 µM, specific NHE-1 and NHE-3 inhibitors. Results: MDCK cells did not express the mRNA for SGLT1 or SGLT2 but did express the GLUT2, NHE-1 and NHE-3 proteins. Under control conditions, we observed a greater contribution of NHE-1 to pHi recovery relative to the other H+ transporters. Acute high glucose treatment increased the HOE-694-sensitive pHi recovery rate and p-Erk1/2 and p90RSK abundance. These parameters were reduced by PD-98059, a Mek inhibitor (1 µM. Chronic high glucose treatment also increased the HOE-694-sensitive pHi recovery rate and p-p38MAPK abundance. Both parameters were reduced by SB-203580, a p38MAPK inhibitor (10 µM. Conclusion: These results suggested that extracellular high glucose stimulated NHE-1 acutely and chronically through Mek/Erk1/2/p90RSK and p38MAPK pathways, respectively.

  7. Gene Expression in the Normal Adult Human Kidney Assessed by Complementary DNA Microarray

    OpenAIRE

    Higgins, John P.T.; Wang, Lingli; Kambham, Neeraja; Montgomery, Kelli; Mason, Veronica; Vogelmann, Stefanie U.; Lemley, Kevin V.; Brown, Patrick O.; Brooks, James D.; van de Rijn, Matt

    2004-01-01

    The kidney is a highly specialized organ with a complex, stereotyped architecture and a great diversity of functions and cell types. Because the microscopic organization of the nephron, the functional unit of the kidney, has a consistent relationship to the macroscopic anatomy of the kidney, knowledge of the characteristic patterns of gene expression in different compartments of the kidney could provide insight into the functions and functional organization of the normal nephron. We studied g...

  8. Screening for Chronic Kidney Disease: Preventing Harm or Harming the Healthy?

    OpenAIRE

    Echouffo-Tcheugui, Justin B.; Kengne, Andre P.

    2012-01-01

    Editors' Summary Background Chronic kidney disease (CKD)—the gradual loss of kidney function—is increasingly common worldwide. In the US, for example, about 26 million adults have CKD, and millions more are at risk of developing the condition. Throughout life, small structures called nephrons inside the kidneys filter waste products and excess water from the blood to make urine. If the nephrons stop working because of injury or disease, the rate of blood filtration decreases, and dangerous am...

  9. Concise Review: Kidney Generation with Human Pluripotent Stem Cells.

    Science.gov (United States)

    Morizane, Ryuji; Miyoshi, Tomoya; Bonventre, Joseph V

    2017-11-01

    Chronic kidney disease (CKD) is a worldwide health care problem, resulting in increased cardiovascular mortality and often leading to end-stage kidney disease, where patients require kidney replacement therapies such as hemodialysis or kidney transplantation. Loss of functional nephrons contributes to the progression of CKD, which can be attenuated but not reversed due to inability to generate new nephrons in human adult kidneys. Human pluripotent stem cells (hPSCs), by virtue of their unlimited self-renewal and ability to differentiate into cells of all three embryonic germ layers, are attractive sources for kidney regenerative therapies. Recent advances in stem cell biology have identified key signals necessary to maintain stemness of human nephron progenitor cells (NPCs) in vitro, and led to establishment of protocols to generate NPCs and nephron epithelial cells from human fetal kidneys and hPSCs. Effective production of large amounts of human NPCs and kidney organoids will facilitate elucidation of developmental and pathobiological pathways, kidney disease modeling and drug screening as well as kidney regenerative therapies. We summarize the recent studies to induce NPCs and kidney cells from hPSCs, studies of NPC expansion from mouse and human embryonic kidneys, and discuss possible approaches in vivo to regenerate kidneys with cell therapies and the development of bioengineered kidneys. Stem Cells 2017;35:2209-2217. © 2017 AlphaMed Press.

  10. 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.

  11. Additive phosphaturic action of parathyrin and calcitonin

    International Nuclear Information System (INIS)

    Oberleitner, H.; Lang, F.; Greger, P.; Sporer, H.; Deetjen, P.

    1980-01-01

    Parathyrin and calcitonin exert their effects on phosphate metabolism by influencing the functions of at least three organ systems, i.e. bone, gut and kidneys. To study the renal effects of these hormones under exclusion of systemic effects microinfusion studies were performed in anesthetised rats. After thyroparathyroidectomy radioactively labelled phosphate containing solutions were microinfused into single proximal convoluted tubules. The tracer recovery in the urine allowed calculation of phosphate reabsorption in the nephron segments beyond the micropuncture site. After a control period of 6 minutes the hormones were superfused to the nephron surface and tracer recovery measured during the following 36 minutes. Within few minutes both, parathyrin and calcitonin, clearly reduced phosphate reabsorption. Infusions of supramaximal doses of either hormone abolished the local action of this hormone but did not influence the effect of the other. Thus the phosphaturic actions of parathyrin and calcitonin are additive, indicating that the hormones involve different mechanisms and/or nephron sites. (author)

  12. A developmentally plastic adult mouse kidney cell line spontaneously generates multiple adult kidney structures

    International Nuclear Information System (INIS)

    Webb, Carol F.; Ratliff, Michelle L.; Powell, Rebecca; Wirsig-Wiechmann, Celeste R.; Lakiza, Olga; Obara, Tomoko

    2015-01-01

    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

  13. Disruption of Hox9,10,11 function results in cellular level lineage infidelity in the kidney.

    Science.gov (United States)

    Drake, Keri A; Adam, Mike; Mahoney, Robert; Potter, S Steven

    2018-04-20

    Hox genes are important regulators of development. The 39 mammalian Hox genes have considerable functional overlap, greatly confounding their study. In this report, we generated mice with multiple combinations of paralogous and flanking Abd-B Hox gene mutations to investigate functional redundancies in kidney development. The resulting mice developed a number of kidney abnormalities, including hypoplasia, agenesis, and severe cysts, with distinct Hox functions observed in early metanephric kidney formation and nephron progenitor maintenance. Most surprising, however, was that extensive removal of Hox shared function in these kidneys resulted in cellular level lineage infidelity. Strikingly, mutant nephron tubules consisted of intermixed cells with proximal tubule, loop of Henle, and collecting duct identities, with some single cells expressing markers associated with more than one nephron segment. These results indicate that Hox genes are required for proper lineage selection/maintenance and full repression of genes involved in cell fate restriction in the developing kidney.

  14. Structural Injury after Lithium Treatment in Human and Rat Kidney involves Glycogen Synthase Kinase-3β Positive Epithelium

    DEFF Research Database (Denmark)

    Kjærsgaard, Gitte; Madsen, Kirsten; Marcussen, Niels

    2011-01-01

    Lithium is reabsorbed by distal nephron segments in sodium depleted states. It was hypothesized that lithium causes permanent injury to the developing kidney particularly in the sodium-retaining phase around weaning through entry into epithelial cells of the distal nephron and inhibition of glyco....... Lithium causes proliferation, structural injury and increases inactive pGSK-3β abundance in these segments. The data are compatible with epithelial entry of lithium and a causal role for GSK-3β in postnatal developing cortical collecting duct epithelium....

  15. Physiologie et Physiopathologie du transport de chlore dans le canal collecteur rénal : caractérisation d’un modèle murin d’Acidose tubulaire rénale distale et Étude des mécanismes de régulation du canal ClC-Kb/Barttin

    OpenAIRE

    Serbin , Bettina

    2016-01-01

    Kidney plays a major role in several biological fonctions as sodium balance or acid-base homeostasis. Chloride transport in the distal nephron is a key element of these two processes. During my thesis, i have worked on two projects related to physiology and pathophysiology of chloride transport in distal nephron. The first study is the functionnal and molecular characterization of a mouse model bearing the most common dominant dRTA mutation in human AE1, R589H, which corresponds to R607H in t...

  16. SGLT2 Inhibitors: Glucotoxicity and Tumorigenesis Downstream the Renal Proximal Tubule?

    Science.gov (United States)

    Bertinat, Romina; Nualart, Francisco; Yáñez, Alejandro J

    2016-08-01

    At present, diabetes mellitus is the main cause of end-stage renal disease. Effective glycaemic management is the most powerful tool to delay the establishment of diabetic complications, such as diabetic kidney disease. Together with reducing blood glucose levels, new anti-diabetic agents are expected not only to control the progression but also to restore known defects of the diabetic kidney. Sodium-glucose co-transporter 2 (SGLT2) inhibitors are promising anti-diabetic agents that reduce hyperglycaemia by impairing glucose reabsorption in proximal tubule of the kidney and increasing glucosuria. SGLT2 inhibitors have shown to reduce glucotoxicity in isolated proximal tubule cells and also to attenuate expression of markers of overall kidney damage in experimental animal models of diabetes, but the actual renoprotective effect for downstream nephron segments is still unknown and deserves further attention. Here, we briefly discuss possible undesired effects of enhanced glucosuria and albuminuria in nephron segments beyond the proximal tubule after SGLT2 inhibitor treatment, offering new lines of research to further understand the renoprotective action of these anti-diabetic agents. Strategies blocking glucose reabsorption by renal proximal tubule epithelial cells (RPTEC) may be protective for RPTEC, but downstream nephron segments will still be exposed to high glucose and albumin levels through the luminal face. The actual effect of constant enhanced glucosuria over distal nephron segments remains to be established. J. Cell. Physiol. 231: 1635-1637, 2016. © 2015 Wiley Periodicals, Inc. © 2015 Wiley Periodicals, Inc.

  17. Kidney stem cells in development, regeneration and cancer.

    Science.gov (United States)

    Dziedzic, Klaudyna; Pleniceanu, Oren; Dekel, Benjamin

    2014-12-01

    The generation of nephrons during development depends on differentiation via a mesenchymal to epithelial transition (MET) of self-renewing, tissue-specific stem cells confined to a specific anatomic niche of the nephrogenic cortex. These cells may transform to generate oncogenic stem cells and drive pediatric renal cancer. Once nephron epithelia are formed the view of post-MET tissue renal growth and maintenance by adult tissue-specific epithelial stem cells becomes controversial. Recently, genetic lineage tracing that followed clonal evolution of single kidney cells showed that the need for new cells is constantly driven by fate-restricted unipotent clonal expansions in varying kidney segments arguing against a multipotent adult stem cell model. Lineage-restriction was similarly maintained in kidney organoids grown in culture. Importantly, kidney cells in which Wnt was activated were traced to give significant clonal progeny indicating a clonogenic hierarchy. In vivo nephron epithelia may be endowed with the capacity akin to that of unipotent epithelial stem/progenitor such that under specific stimuli can clonally expand/self renew by local proliferation of mature differentiated cells. Finding ways to ex vivo preserve and expand the observed in vivo kidney-forming capacity inherent to both the fetal and adult kidneys is crucial for taking renal regenerative medicine forward. Some of the strategies used to achieve this are sorting human fetal nephron stem/progenitor cells, growing adult nephrospheres or reprogramming differentiated kidney cells toward expandable renal progenitors. Copyright © 2014. Published by Elsevier Ltd.

  18. Perinatal radiation-induced renal damage in the beagle

    International Nuclear Information System (INIS)

    Jaenke, R.S.; Angleton, G.M.

    1990-01-01

    The developing perinatal kidney is particularly sensitive to radiation. The pathogenesis of the radiation-induced lesion is related to the destruction of outer cortical developing nephrons and direct radiation injury with secondary hemodynamic alterations in remnant nephrons. In this study, which is part of a life span investigation of the effects of whole-body gamma radiation during prenatal and early postnatal life, dogs were given 0, 0.16, 0.83, or 1.25 Gy irradiation at either 55 days postcoitus or 2 days postpartum and were examined morphometrically and histopathologically at 70 days of age. Although irradiated dogs showed no reduction in the total number of nephrons per kidney, there was a significant increase in the total number and relative percentage of immature, dysplastic glomeruli. In addition, deeper cortical glomeruli of irradiated kidneys exhibited mesangial sclerosis similar to that associated with progressive renal failure in our previous studies. These findings are in accord with those reported at doses of 2.24 to 3.57 Gy and demonstrate that the perinatal kidney is affected by radiation doses much lower than previously demonstrated

  19. LIM kinase function and renal growth: Potential role for LIM kinases in fetal programming of kidney development.

    Science.gov (United States)

    Sparrow, Alexander J; Sweetman, Dylan; Welham, Simon J M

    2017-10-01

    Maternal dietary restriction during pregnancy impairs nephron development and results in offspring with fewer nephrons. Cell turnover in the early developing kidney is altered by exposure to maternal dietary restriction and may be regulated by the LIM-kinase family of enzymes. We set out to establish whether disturbance of LIM-kinase activity might play a role in the impairment of nephron formation. E12.5 metanephric kidneys and HK2 cells were grown in culture with the pharmacological LIM-kinase inhibitor BMS5. Organs were injected with DiI, imaged and cell numbers measured over 48h to assess growth. Cells undergoing mitosis were visualised by pH3 labelling. Growth of cultured kidneys reduced to 83% of controls after exposure to BMS5 and final cell number to 25% of control levels after 48h. Whilst control and BMS5 treated organs showed cells undergoing mitosis (100±11 cells/field vs 113±18 cells/field respectively) the proportion in anaphase was considerably diminished with BMS5 treatment (7.8±0.8% vs 0.8±0.6% respectively; Plabelled cells migrated in 100% of control cultures vs 0% BMS5 treated organs. The number of nephrogenic precursor cells appeared depleted in whole organs and formation of new nephrons was blocked by exposure to BMS5. Pharmacological blockade of LIM-kinase function in the early developing kidney results in failure of renal development. This is likely due to prevention of dividing cells from completion of mitosis with their resultant loss. Copyright © 2017 Elsevier Inc. All rights reserved.

  20. Microinjection studies of phosphate permeability in rats during mild saline diuresis: influence of acute thyroparathyroidectomy and parathormone administration

    International Nuclear Information System (INIS)

    Poujeol, P.; Rouffignac, C. de.

    1975-01-01

    The tubular permeability to phosphate of the different segments of the rat nephron and the influence of parathyroid hormone on such a permeability were investigated. Tracer microinjections of 32 P and 3 H inulin were performed in control, acutely thyroparathyroidectomized (TPTX) and TPTX + PTH animals undergoing saline diuresis. In order to estimate the 32 P reabsorption capacity of the proximal convoluted tubule (PCT), the loop of Henle and the terminal part of the nephron, microinjections were performed in early proximal, late proximal and early distal tubules respectively. The results reported confirm that the renal phosphate reabsorption is under PTH control [fr

  1. Structural and Functional Changes in Human Kidneys with Healthy Aging.

    Science.gov (United States)

    Hommos, Musab S; Glassock, Richard J; Rule, Andrew D

    2017-10-01

    Aging is associated with significant changes in structure and function of the kidney, even in the absence of age-related comorbidities. On the macrostructural level, kidney cortical volume decreases, surface roughness increases, and the number and size of simple renal cysts increase with age. On the microstructural level, the histologic signs of nephrosclerosis (arteriosclerosis/arteriolosclerosis, global glomerulosclerosis, interstitial fibrosis, and tubular atrophy) all increase with age. The decline of nephron number is accompanied by a comparable reduction in measured whole-kidney GFR. However, single-nephron GFR remains relatively constant with healthy aging as does glomerular volume. Only when glomerulosclerosis and arteriosclerosis exceed that expected for age is there an increase in single-nephron GFR. In the absence of albuminuria, age-related reduction in GFR with the corresponding increase in CKD (defined by an eGFRage-standardized mortality risk or ESRD. These findings raise the question of whether disease labeling of an age-related decline in GFR is appropriate. These findings also emphasize the need for a different management approach for many elderly individuals considered to have CKD by current criteria. Copyright © 2017 by the American Society of Nephrology.

  2. Functional and pharmacological consequences of the distribution of voltage-gated calcium channels in the renal blood vessels

    DEFF Research Database (Denmark)

    Hansen, P B L

    2013-01-01

    Calcium channel blockers are widely used to treat hypertension because they inhibit voltage-gated calcium channels that mediate transmembrane calcium influx in, for example, vascular smooth muscle and cardiomyocytes. The calcium channel family consists of several subfamilies, of which the L......-type is usually associated with vascular contractility. However, the L-, T- and P-/Q-types of calcium channels are present in the renal vasculature and are differentially involved in controlling vascular contractility, thereby contributing to regulation of kidney function and blood pressure. In the preglomerular...... vascular bed, all the three channel families are present. However, the T-type channel is the only channel in cortical efferent arterioles which is in contrast to the juxtamedullary efferent arteriole, and that leads to diverse functional effects of L- and T-type channel inhibition. Furthermore...

  3. [Mechanism of the diuretic effect of eufillin].

    Science.gov (United States)

    Kantariia, V A; Lebedev, A A

    1975-01-01

    In acute experiments on rats the xanthine diuretic euphylline did not block the short-circuited current in the proximal tubule, nor did it lower the transtubular potential and the transepithelial resistance of the nephron wall. The diuretic speeded up significantly the passage of the tubular fluid along the proximal region of the nephron and Henle's loop. The dihydroergotoxin and inderal blocking of adrenoreceptors did not produce any influence on the renal effects of the xanthine agent. Reserpine totally blocked the diuretic and saluretic effects of euphylline, whereas other sympatholytics, such as alpha-methyl-dofa, anthabus and hemedin, did not modify the action of the diuretic.

  4. Rhythmic components in renal autoregulation: Nonlinear modulation phenomena

    International Nuclear Information System (INIS)

    Pavlov, A.N.; Sosnovtseva, O.V.; Pavlova, O.N.; Mosekilde, E.; Holstein-Rathlou, N.-H.

    2009-01-01

    Autoregulation of nephron blood flow involves two oscillatory processes: the tubular-flow sensitive tubuloglomerular feedback (TGF) mechanism and the blood-pressure sensitive myogenic mechanism. Both act to regulate the diameter of the afferent arteriole, which carries blood to the nephron. In this paper, we apply wavelet analysis to time series of the proximal tubular pressure obtained from normotensive and hypertensive rats to study how the TGF-mediated oscillations modulate both the frequency and the amplitude of the myogenic oscillations. The tubular pressure oscillations are nearly periodic for normotensive rats, but irregular (or chaotic) for rats with hypertension. Modulation phenomena are clearly observed in both types of rats, but the effect is stronger in those with hypertension.

  5. The cellular basis of renal injury by radiation

    International Nuclear Information System (INIS)

    Williams, M.V.

    1986-01-01

    This review with substantial bibliography summarises renal assay techniques available and discusses the histological and functional studies leading to differing opinions between the belief that vascular injury provides a general explanation of the late effects of radiotherapy and the opposing view that parenchymal cell damage is more important. It is proposed that the link between glomerular and tubular function obscures the primary site of injury and that radiation injury will result in a reduction of functioning nephron mass by primary damage to the tubules or glomeruli. Compensatory renal vasodilation would close a positive feedback loop. Radiation could also cause direct vascular injury; decreased renal perfusion and hypertension would result. Again sensitisation to hypertensive vascular damage would close a feedback loop. (UK)

  6. Mechanisms of urine concentration and dilution (1961)

    International Nuclear Information System (INIS)

    Morel, F.; Guinnebault, M.

    1961-01-01

    This paper is devoted to the analysis of a problem in the field of renal physiology which has shown many new developments during the course of the last few years. The following are treated successively: a) the data obtained from measurements of free water clearance and their interpretation; b) the data provided by nephron morphology and the comparative anatomy of the kidney ; c) the data relative to the existence of an intrarenal osmotic gradient; d) the principle of concentration multiplication by a counter current technique; e) the present day theory of counter current concentration of urine, and f) the physiological check on dilution and concentration mechanisms in urine. Lastly, the advantages of the modern theory and the unknown factors which remain are discussed. (authors) [fr

  7. Cogeneration techniques; Les techniques de cogeneration

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1999-10-01

    This dossier about cogeneration techniques comprises 12 parts dealing successively with: the advantages of cogeneration (examples of installations, electrical and thermal efficiency); the combustion turbine (principle, performances, types); the alternative internal combustion engines (principle, types, rotation speed, comparative performances); the different configurations of cogeneration installations based on alternative engines and based on steam turbines (coal, heavy fuel and natural gas-fueled turbines); the environmental constraints of combustion turbines (pollutants, techniques of reduction of pollutant emissions); the environmental constraints of alternative internal combustion engines (gas and diesel engines); cogeneration and energy saving; the techniques of reduction of pollutant emissions (pollutants, unburnt hydrocarbons, primary and secondary (catalytic) techniques, post-combustion); the most-advanced configurations of cogeneration installations for enhanced performances (counter-pressure turbines, massive steam injection cycles, turbo-chargers); comparison between the performances of the different cogeneration techniques; the tri-generation technique (compression and absorption cycles). (J.S.)

  8. Characterizing multimode interaction in renal autoregulation

    International Nuclear Information System (INIS)

    Pavlov, A N; Pavlova, O N; Sosnovtseva, O V; Mosekilde, E; Holstein-Rathlou, N-H

    2008-01-01

    The purpose of this paper is to demonstrate how modern statistical techniques of non-stationary time-series analysis can be used to characterize the mutual interaction among three coexisting rhythms in nephron pressure and flow regulation. Besides a relatively fast vasomotoric rhythm with a period of 5–8 s and a somewhat slower mode arising from an instability in the tubuloglomerular feedback mechanism, we also observe a very slow mode with a period of 100–200 s. Double-wavelet techniques are used to study how the very slow rhythm influences the two faster modes. In a broader perspective, the paper emphasizes the significance of complex dynamic phenomena in the normal and pathological function of physiological systems and discusses how simulation methods can help to understand the underlying biological mechanisms. At the present there is no causal explanation of the very slow mode. However, vascular oscillations with similar frequencies have been observed in other tissues

  9. Mechanisms of urine concentration and dilution (1961); Les mecanismes de concentration et de dilution de l'urine (1961)

    Energy Technology Data Exchange (ETDEWEB)

    Morel, F.; Guinnebault, M. [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1961-07-01

    This paper is devoted to the analysis of a problem in the field of renal physiology which has shown many new developments during the course of the last few years. The following are treated successively: a) the data obtained from measurements of free water clearance and their interpretation; b) the data provided by nephron morphology and the comparative anatomy of the kidney ; c) the data relative to the existence of an intrarenal osmotic gradient; d) the principle of concentration multiplication by a counter current technique; e) the present day theory of counter current concentration of urine, and f) the physiological check on dilution and concentration mechanisms in urine. Lastly, the advantages of the modern theory and the unknown factors which remain are discussed. (authors) [French] Cette revue de question est consacree l'analyse d'un probleme de physiologie renale qui, au cours des dernieres annees, a subi un developpement et un renouveau remarquables. Sont successivement exposes: a) les donnees fournies par les mesures de clearance de l'eau libre et leur interpretation; b) les donnees fournies par la morphologie des nephrons et l'anatomie comparee du rein; c) les donnees concernant l'existence d'un gradient osmotique intrarenal; d) le principe de multiplication de concentration par contrecourant; e) la theorie actuelle de concentration de l'urine par contre-courant, et f) le controle physiologique des mecanismes de dilution et de concentration de l'urine. Les avantages de la theorie moderne et les obscurites qui subsistent sont enfin discutes. (auteurs)

  10. Mechanisms of urine concentration and dilution (1961); Les mecanismes de concentration et de dilution de l'urine (1961)

    Energy Technology Data Exchange (ETDEWEB)

    Morel, F; Guinnebault, M [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1961-07-01

    This paper is devoted to the analysis of a problem in the field of renal physiology which has shown many new developments during the course of the last few years. The following are treated successively: a) the data obtained from measurements of free water clearance and their interpretation; b) the data provided by nephron morphology and the comparative anatomy of the kidney ; c) the data relative to the existence of an intrarenal osmotic gradient; d) the principle of concentration multiplication by a counter current technique; e) the present day theory of counter current concentration of urine, and f) the physiological check on dilution and concentration mechanisms in urine. Lastly, the advantages of the modern theory and the unknown factors which remain are discussed. (authors) [French] Cette revue de question est consacree l'analyse d'un probleme de physiologie renale qui, au cours des dernieres annees, a subi un developpement et un renouveau remarquables. Sont successivement exposes: a) les donnees fournies par les mesures de clearance de l'eau libre et leur interpretation; b) les donnees fournies par la morphologie des nephrons et l'anatomie comparee du rein; c) les donnees concernant l'existence d'un gradient osmotique intrarenal; d) le principe de multiplication de concentration par contrecourant; e) la theorie actuelle de concentration de l'urine par contre-courant, et f) le controle physiologique des mecanismes de dilution et de concentration de l'urine. Les avantages de la theorie moderne et les obscurites qui subsistent sont enfin discutes. (auteurs)

  11. Zeb1 Is a Potential Regulator of Six2 in the Proliferation, Apoptosis and Migration of Metanephric Mesenchyme Cells

    Directory of Open Access Journals (Sweden)

    Yuping Gu

    2016-08-01

    Full Text Available Nephron progenitor cells surround around the ureteric bud tips (UB and inductively interact with the UB to originate nephrons, the basic units of renal function. This process is determined by the internal balance between self-renewal and consumption of the nephron progenitor cells, which is depending on the complicated regulation networks. It has been reported that Zeb1 regulates the proliferation of mesenchymal cells in mouse embryos. However, the role of Zeb1 in nephrons generation is not clear, especially in metanephric mesenchyme (MM. Here, we detected cell proliferation, apoptosis and migration in MM cells by EdU assay, flow cytometry assay and wound healing assay, respectively. Meanwhile, Western and RT-PCR were used to measure the expression level of Zeb1 and Six2 in MM cells and developing kidney. Besides, the dual-luciferase assay was conducted to study the molecular relationship between Zeb1 and Six2. We found that knock-down of Zeb1 decreased cell proliferation, migration and promoted cell apoptosis in MM cells and Zeb1 overexpression leaded to the opposite data. Western-blot and RT-PCR results showed that knock-down of Zeb1 decreased the expression of Six2 in MM cells and Zeb1 overexpression contributed to the opposite results. Similarly, Zeb1 promoted Six2 promoter reporter activity in luciferase assays. However, double knock-down of Zeb1 and Six2 did not enhance the apoptosis of MM cells compared with control cells. Nevertheless, double silence of Zeb1 and Six2 repressed cell proliferation. In addition, we also found that Zeb1 and Six2 had an identical pattern in distinct developing phases of embryonic kidney. These results indicated that there may exist a complicated regulation network between Six2 and Zeb1. Together, we demonstrate Zeb1 promotes proliferation and apoptosis and inhibits the migration of MM cells, in association with Six2.

  12. Zeb1 Is a Potential Regulator of Six2 in the Proliferation, Apoptosis and Migration of Metanephric Mesenchyme Cells

    Science.gov (United States)

    Gu, Yuping; Zhao, Ya; Zhou, Yuru; Xie, Yajun; Ju, Pan; Long, Yaoshui; Liu, Jianing; Ni, Dongsheng; Cao, Fen; Lyu, Zhongshi; Mao, Zhaomin; Hao, Jin; Li, Yiman; Wan, Qianya; Kanyomse, Quist; Liu, Yamin; Ren, Die; Ning, Yating; Li, Xiaofeng; Zhou, Qin; Li, Bing

    2016-01-01

    Nephron progenitor cells surround around the ureteric bud tips (UB) and inductively interact with the UB to originate nephrons, the basic units of renal function. This process is determined by the internal balance between self-renewal and consumption of the nephron progenitor cells, which is depending on the complicated regulation networks. It has been reported that Zeb1 regulates the proliferation of mesenchymal cells in mouse embryos. However, the role of Zeb1 in nephrons generation is not clear, especially in metanephric mesenchyme (MM). Here, we detected cell proliferation, apoptosis and migration in MM cells by EdU assay, flow cytometry assay and wound healing assay, respectively. Meanwhile, Western and RT-PCR were used to measure the expression level of Zeb1 and Six2 in MM cells and developing kidney. Besides, the dual-luciferase assay was conducted to study the molecular relationship between Zeb1 and Six2. We found that knock-down of Zeb1 decreased cell proliferation, migration and promoted cell apoptosis in MM cells and Zeb1 overexpression leaded to the opposite data. Western-blot and RT-PCR results showed that knock-down of Zeb1 decreased the expression of Six2 in MM cells and Zeb1 overexpression contributed to the opposite results. Similarly, Zeb1 promoted Six2 promoter reporter activity in luciferase assays. However, double knock-down of Zeb1 and Six2 did not enhance the apoptosis of MM cells compared with control cells. Nevertheless, double silence of Zeb1 and Six2 repressed cell proliferation. In addition, we also found that Zeb1 and Six2 had an identical pattern in distinct developing phases of embryonic kidney. These results indicated that there may exist a complicated regulation network between Six2 and Zeb1. Together, we demonstrate Zeb1 promotes proliferation and apoptosis and inhibits the migration of MM cells, in association with Six2. PMID:27509493

  13. Transforming an educational virtual reality simulation into a work of fine art.

    Science.gov (United States)

    Panaiotis; Addison, Laura; Vergara, Víctor M; Hakamata, Takeshi; Alverson, Dale C; Saiki, Stanley M; Caudell, Thomas Preston

    2008-01-01

    This paper outlines user interface and interaction issues, technical considerations, and problems encountered in transforming an educational VR simulation of a reified kidney nephron into an interactive artwork appropriate for a fine arts museum.

  14. Time-varying properties of renal autoregulatory mechanisms

    DEFF Research Database (Denmark)

    Zou, Rui; Cupples, Will A; Yip, K P

    2002-01-01

    In order to assess the possible time-varying properties of renal autoregulation, time-frequency and time-scaling methods were applied to renal blood flow under broad-band forced arterial blood pressure fluctuations and single-nephron renal blood flow with spontaneous oscillations obtained from...... normotensive (Sprague-Dawley, Wistar, and Long-Evans) rats, and spontaneously hypertensive rats. Time-frequency analyses of normotensive and hypertensive blood flow data obtained from either the whole kidney or the single-nephron show that indeed both the myogenic and tubuloglomerular feedback (TGF) mechanisms...... have time-varying characteristics. Furthermore, we utilized the Renyi entropy to measure the complexity of blood-flow dynamics in the time-frequency plane in an effort to discern differences between normotensive and hypertensive recordings. We found a clear difference in Renyi entropy between...

  15. Aging and the Kidneys: Anatomy, Physiology and Consequences for Defining Chronic Kidney Disease.

    Science.gov (United States)

    Glassock, Richard J; Rule, Andrew D

    2016-01-01

    The varied functions of the kidneys are influenced by the complex process of aging. The glomerular filtration rate (GFR) steadily declines with normal aging, and the progress of this process can be influenced by superimposed diseases. Microscopically, nephron numbers decrease as global glomerulosclerosis becomes more evident. The precise mechanisms underlying nephron loss with aging are not well understood, but derangements in podocyte biology appear to be involved. Classifications of chronic kidney disease (CKD) incorporate GFR values and attendant risk of adverse events. Arbitrary and fixed thresholds of GFR for defining CKD have led to an overdiagnosis of CKD in the elderly. An age-sensitive definition of CKD could offer a solution to this problem and more meaningfully capture the prognostic implications of CKD. © 2016 S. Karger AG, Basel.

  16. Diuretics and salt transport along the nephron.

    Science.gov (United States)

    Bernstein, Paul L; Ellison, David H

    2011-11-01

    The clinical use of diuretics almost uniformly predated the localization of their site of action. The consequence of diuretic specificity predicts clinical application and side effect, and the proximity of the sodium transporters, one to the next, often dictates potency or diuretic efficiency. All diuretics function by inhibiting the normal transport of sodium from the filtrate into the renal tubular cells. This movement of sodium into the renal epithelial cells on the apical side is facilitated by a series of transporters whose function is, in turn, dependent on the adenosine triphosphate (ATP)-dependent Na-K cotransporter on the basolateral side of the cell. Our growing understanding of the physiology of sodium transport has spawned new possibilities for diuretic development. Copyright © 2011 Elsevier Inc. All rights reserved.

  17. Elevated blood pressure in offspring of rats exposed to diverse chemicals during pregnancy

    Science.gov (United States)

    Adverse intrauterine environments are associated with increased risk of later disease, including cardiovascular disease and hypertension. As a potential bioindicator of such an adverse environment, we measured blood pressure (BP), renal nephron endowment, renal glucocorticoid rec...

  18. Compensatory renal hypertrophy and the handling of an acute nephrotoxicant in a model of aging.

    Science.gov (United States)

    Oliveira, Cláudia S; Joshee, Lucy; Zalups, Rudolfs K; Bridges, Christy C

    2016-03-01

    Aging often results in progressive losses of functioning nephrons, which can lead to a significant reduction in overall renal function. Because of age-related pathological changes, the remaining functional nephrons within aged kidneys may be unable to fully counteract physiological and/or toxicological challenges. We hypothesized that when the total functional renal mass of aged rats is reduced by 50%, the nephrons within the remnant kidney do not fully undergo the functional and physiological changes that are necessary to maintain normal fluid and solute homeostasis. We also tested the hypothesis that the disposition and handling of a nephrotoxicant are altered significantly in aged kidneys following an acute, 50% reduction in functional renal mass. To test these hypotheses, we examined molecular indices of renal cellular hypertrophy and the disposition of inorganic mercury (Hg(2+)), a model nephrotoxicant, in young control, young uninephrectomized (NPX), aged control and aged NPX Wistar rats. We found that the process of aging reduces the ability of the remnant kidney to undergo compensatory renal growth. In addition, we found that an additional reduction in renal mass in aged animals alters the disposition of Hg(2+) and potentially alters the risk of renal intoxication by this nephrotoxicant. To our knowledge, this study represents the first report of the handling of a nephrotoxicant in an aged animal following a 50% reduction in functional renal mass. Copyright © 2015 Elsevier Inc. All rights reserved.

  19. Gross, histological and ultrastructural morphology of the aglomerular kidney in the lined seahorse Hippocampus erectus.

    Science.gov (United States)

    Fogelson, S B; Yanong, R P E; Kane, A; Teal, C N; Berzins, I K; Smith, S A; Brown, C; Camus, A

    2015-09-01

    Histologic evaluation of the renal system in the lined seahorse Hippocampus erectus reveals a cranial kidney with low to moderate cellularity, composed of a central dorsal aorta, endothelial lined capillary sinusoids, haematopoietic tissue, fine fibrovascular stroma, ganglia and no nephrons. In comparison, the caudal kidney is moderately to highly cellular with numerous highly convoluted epithelial lined tubules separated by interlacing haematopoietic tissue, no glomeruli, fine fibrovascular stroma, numerous capillary sinusoids, corpuscles of Stannius and clusters of endocrine cells adjacent to large calibre vessels. Ultrastructural evaluation of the renal tubules reveals minimal variability of the tubule epithelium throughout the length of the nephron and the majority of tubules are characterized by epithelial cells with few apical microvilli, elaborate basal membrane infolding, rare electron dense granules and abundant supporting collagenous matrix. © 2015 The Fisheries Society of the British Isles.

  20. Potassium secretion in mammalian distal colon

    DEFF Research Database (Denmark)

    Sørensen, Mads Vaarby

    2009-01-01

    Epithelial organs adjust the „inner milieu“ of the body and are crucial for all homeostatic processes. Epithelial transport of different solutes and water is regulated phenomena. The regulation processes include both long term hormonal regulation and short term local agonist mediated regulation....... This research project is the summary of 3 original papers addressing the functional role of different regulating factors on ion transport in mouse distal colon. The first paper addresses the effect of luminal nucleotides on electrogenic Na+ absorption. The distal colon, like the distal nephron is an aldosterone......-sensitive tissue and participates in the regulation of Na+ excretion. In the distal nephron it was found that luminal nucleotides inhibit ENaC-mediated Na+ absorption. Here it was addressed whether luminal nucleotides regulate Na+ absorption and if so, which of the known luminal P2 receptors are involved. Using...

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

    Science.gov (United States)

    Fernández García, María Teresa; Núñez Martínez, Paula; García de la Fuente, Vanessa; Sánchez Pitiot, Marta; Muñiz Salgueiro, María Del Carmen; Perillán Méndez, Carmen; Argüelles Luis, Juan; Astudillo González, Aurora

    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. Copyright © 2016 Sociedad Española de Nefrología. Published by Elsevier España, S.L.U. All rights reserved.

  2. Tissue injury after lithium treatment in human and rat postnatal kidney involves glycogen synthase kinase 3β-positive epithelium

    DEFF Research Database (Denmark)

    Kjaersgaard, Gitte; Madsen, Kirsten; Marcussen, Niels

    2012-01-01

    plasma lithium concentration of 1.0 mmol/L. Kidneys from lithium-treated rat pups exhibited dilated distal nephron segments with microcysts. Stereological analysis showed reduced cortex and outer medullary volumes. Lithium increased pGSK-3β and the proliferation marker PCNA protein abundances in cortex...... concentration capacity and diminished outer medullary volume. Histological sections of nephrectomy samples and a biopsy from 3 long-term lithium-treated patients showed multiple cortical microcysts that originated from normally appearing tubules. Microcysts were lined by a cuboidal PCNA-, GSK-3β- and pGSK-3β......It was hypothesized that lithium causes accelerated and permanent injury to the postnatally developing kidney through entry into epithelial cells of the distal nephron and inhibition of glycogen synthase kinase-3β (GSK-3β). GSK-3β immunoreactivity was associated with glomeruli, thick ascending limb...

  3. Nephron-sparing surgery for treatment of reninoma: a rare renin secreting tumor causing secondary hypertension.

    Science.gov (United States)

    Torricelli, Fabio Cesar Miranda; Marchini, Giovanni Scala; Colombo, Jose Roberto; Coelho, Rafael Ferreira; Nahas, Willian Carlos; Srougi, Miguel

    2015-01-01

    A 25-year-old hypertensive female patient was referred to our institution. Initial workup exams demonstrated a 2.8 cm cortical lower pole tumor in the right kidney. She underwent laparoscopic partial nephrectomy without complications. Histopathologic examination revealed a rare juxtaglomerular cell tumor known as reninoma. After surgery, she recovered uneventfully and all medications were withdrawn. Case hypothesis: Secondary arterial hypertension is a matter of great interest to urologists and nephrologists. Renovascular hypertension, primary hyperadosteronism and pheocromocytoma are potential diagnosis that must not be forgotten and should be excluded. Although rare, chronic pyelonephritis and renal tumors as rennin-producing tumors, nephroblastoma, hypernephroma, and renal cell carcinoma might also induce hypertension and should be in the diagnostic list of clinicians. Promising future implications: Approximately 5% of patients with high blood pressure have specific causes and medical investigation may usually identify such patients. Furthermore, these patients can be successfully treated and cured, most times by minimally invasive techniques. This interesting case might expand knowledge of physicians and aid better diagnostic care in future medical practice.

  4. Consensus Recommendations for the Diagnostic Investigation of Dogs with Suspected Glomerular Disease

    NARCIS (Netherlands)

    Littman, M.P.; Daminet, S.; Grauer, G.F.; Lees, G.E.; van Dongen, A.M.|info:eu-repo/dai/nl/097672637

    2013-01-01

    Background The International Renal Interest Society (IRIS) offers guidelines for chronic kidney disease and acute kidney injury. As dogs with glomerular disease may present differently and require different treatment than those with whole nephron or tubular disease, the IRIS Canine

  5. Renal cell carcinoma as a cause of iron deficiency anemia

    African Journals Online (AJOL)

    Amar A. Dowd

    derived from the various parts of the nephron (epithelium or renal tubules) and possessing ... [3] is hematuria, flank pain, and an abdominal mass, similar to bloat- ... mass in the right kidney implicating its anterior aspect, measuring 62 × 48 mm.

  6. Application of Wavelet-Based Tools to Study the Dynamics of Biological Processes

    DEFF Research Database (Denmark)

    Pavlov, A. N.; Makarov, V. A.; Mosekilde, Erik

    2006-01-01

    The article makes use of three different examples (sensory information processing in the rat trigeminal complex, intracellular interaction in snail neurons and multimodal dynamics in nephron autoregulation) to demonstrate how modern approaches to time-series analysis based on the wavelet-transfor...

  7. Double-wavelet approach to study frequency and amplitude modulation in renal autoregulation

    DEFF Research Database (Denmark)

    Sosnovtseva, Olga; Pavlov, A.N.; Mosekilde, Erik

    2004-01-01

    Biological time series often display complex oscillations with several interacting rhythmic components. Renal autoregulation, for instance, involves at least two separate mechanisms both of which can produce oscillatory variations in the pressures and flows of the individual nephrons. Using doubl...

  8. Dismantling techniques

    Energy Technology Data Exchange (ETDEWEB)

    Wiese, E.

    1998-03-13

    Most of the dismantling techniques used in a Decontamination and Dismantlement (D and D) project are taken from conventional demolition practices. Some modifications to the techniques are made to limit exposure to the workers or to lessen the spread of contamination to the work area. When working on a D and D project, it is best to keep the dismantling techniques and tools as simple as possible. The workers will be more efficient and safer using techniques that are familiar to them. Prior experience with the technique or use of mock-ups is the best way to keep workers safe and to keep the project on schedule.

  9. Dismantling techniques

    International Nuclear Information System (INIS)

    Wiese, E.

    1998-01-01

    Most of the dismantling techniques used in a Decontamination and Dismantlement (D and D) project are taken from conventional demolition practices. Some modifications to the techniques are made to limit exposure to the workers or to lessen the spread of contamination to the work area. When working on a D and D project, it is best to keep the dismantling techniques and tools as simple as possible. The workers will be more efficient and safer using techniques that are familiar to them. Prior experience with the technique or use of mock-ups is the best way to keep workers safe and to keep the project on schedule

  10. Assessment of Fetal Kidney Growth and Birth Weight in an Indigenous Australian Cohort

    Directory of Open Access Journals (Sweden)

    Christopher J. Diehm

    2018-01-01

    Full Text Available Introduction: Indigenous Australians experience higher rates of renal disease and hypertension than non-Indigenous Australians. Low birth weight is recognized as a contributing factor in chronic disease and has been shown to increase the risk of renal failure in adulthood. A smaller kidney volume with fewer nephrons places an individual at risk of hypertension and renal failure. Indigenous Australians have fewer nephrons than non-Indigenous Australians. In this study, intrauterine fetal and kidney growth were evaluated in 174 Indigenous Australian babies throughout gestation in order to record and evaluate fetal growth and kidney size, within a population that is at high risk for chronic illness.Methods: Pregnant women that identified as Indigenous, or non-Indigenous women that were pregnant with a partner who identified as an Indigenous Australian were eligible to participate. Maternal history, smoking status, blood and urine samples and fetal ultrasounds were collected throughout pregnancy. Fetal kidney measurements were collected using ultrasound. Statistical analysis was performed using the Stata 14.1 software package.Results: 15.2% of babies were born prematurely. 44% of the mothers reported smoking in pregnancy. The median birth weight of this cohort was 3,240 g. Male fetuses had higher kidney to body weight ratios than female fetuses (P = 0.02. The birth weights of term neonates whose mothers smoked during pregnancy were lower (327 g, P < 0.001 than the birth weights of term babies from non-smoking mothers. The kidney volumes of babies whose mothers smoked were also smaller (P = 0.02, but were in proportion to body weight.Conclusion: In this cohort of Indigenous women smoking was associated with both increased number of preterm births and with a reduction in birth weights, even of term infants. Since kidney volume is a surrogate measure of nephron number and nephrogenesis is complete at birth, babies whose mothers smoked during pregnancy

  11. Reduced renal length and volume 20 years after very preterm birth

    NARCIS (Netherlands)

    M.G. Keijzer-Veen (Mandy); A.S. Devos (Annick); M. Meradji (Morteza); F.W. Dekker (Friedo); J. Nauta (Jeroen); A.J. van der Heijden (Bert)

    2010-01-01

    textabstractIntrauterine growth retardation is presumed to be associated with decreased renal size and impaired renal function as a result of stunted kidney development and nephron deficit. To study whether very preterm birth also affects renal size at young adulthood, we sonographically measured

  12. Uninephrectomy in young age or chronic salt loading causes salt-sensitive hypertension in adult rats

    DEFF Research Database (Denmark)

    Carlström, Mattias; Sällström, Johan; Skøtt, Ole

    2007-01-01

    animals raised with normal-salt diet (UNX) or high-salt diet (UNX+HS). In the adult animals, renal and cardiovascular functions were evaluated and blood pressure recorded telemetrically under different sodium conditions (normal, high, and low). Hypertension was present in UNX+HS (122+/-9 mm Hg), UNX (101......+/-3 mm Hg), and HS (96+/-1 mm Hg) groups on normal-salt diets compared with the controls (84+/-2 mm Hg), and the blood pressure was salt sensitive (high- versus normal-salt diet; 23+/-3, 9+/-2, 7+/-2, and 1+/-1 mm Hg, respectively). The hypertensive groups (UNX+HS, UNX, and HS) had increased diuresis......The importance of nephron endowment and salt intake for the development of hypertension is under debate. The present study was designed to investigate whether reduced nephron number, after completion of nephrogenesis, or chronic salt loading causes renal injury and salt-sensitive hypertension...

  13. Kidney Rehabilitation Technology by Improving Blood Flow and Nerve Activation

    International Nuclear Information System (INIS)

    Mohd Jamil Hashim

    2016-01-01

    The rehabilitation of kidney is impossible from doctors point of view. Kidney failure happens when nephron in kidney fail to filter blood and water. Two major causes of kidney failure. First is the shrinkage of kidney and the second is the blockage of kidney medulla. Kidney shrinkage is because nephron damage due to long term diabetes (Nephrology expert point of view). Whereas blockage of kidney is due to food consume which in turn build up deposit at the blood duct connecting to the medulla. Experiment specimen own body. The rehabilitation methodology is to build up your blood flow system and nerve activation. Result from the study is through analyzing blood components such as creatinine, hemoglobin, urea and potassium. Conclusion, creatinine value has lowered and kidney shrinkage has normalize to its original size. It is hopeful I regain my health 100 % when my GFR reading achieved below 100. (author)

  14. In vivo MR perfusion imaging of renal artery stenosis

    International Nuclear Information System (INIS)

    Powers, T.; Lorenz, C.H.; Bain, R.; Holburn, G.; Price, R.R.

    1989-01-01

    Various techniques have been developed for noninvasive evaluation of renal blood flow. More important in the assessment of potential renal ischemia may be actual perfusion of the nephron mass. MR pulse sequences have been devised that allow perfusion imaging (PI) in a dog model of renal artery stenosis. Unilateral renal artery stenosis was created in mongrel dogs and quantitation of renal blood flow was obtained with radioactive microspheres. Perfusion imaging was performed on a 1.5-T system to obtain the apparent diffusion coefficient. During initial studies, it was found that the usual gradient factor used in brain PI was too high for renal studies; a factor of < 50 was found to be optimal. Additionally, respiratory gating with acquisition at end expiration was necessary to prevent renal motion. Recent studies have shown that PI reflects the asymmetry of flow in this model

  15. Robot-assisted partial nephrectomy in contemporary practice

    Energy Technology Data Exchange (ETDEWEB)

    Tanagho, Youssef S.; Bhayani, Sam B.; Figenshau, Robert S., E-mail: tanaghoy@wudosis.wustl.edu [Division of Urologic Surgery, Washington University School of Medicine, St. Louis, MO (United States)

    2013-01-11

    Laparoscopic renal surgery is associated with reduced blood loss, shorter hospital stay, enhanced cosmesis, and more rapid convalescence relative to open renal surgery. Laparoscopic partial nephrectomy (LPN) is a minimally invasive, nephron-sparing alternative to laparoscopic radical nephrectomy (RN) for the management of small renal masses. While offering similar oncological outcomes to laparoscopic RN, the technical challenges and prolonged learning curve associated with LPN limit its wider dissemination. Robot-assisted partial nephrectomy (RAPN), although still an evolving procedure with no long-term data, has emerged as a viable alternative to LPN, with favorable preliminary outcomes. This article provides an overview of the role of RAPN in the management of renal cell carcinoma. The clinical indications and principles of surgical technique for this procedure are discussed. The oncological, renal functional, and perioperative outcomes of RAPN are also evaluated, as are complication rates.

  16. Robot-assisted partial nephrectomy in contemporary practice

    International Nuclear Information System (INIS)

    Tanagho, Youssef S.; Bhayani, Sam B.; Figenshau, Robert S.

    2013-01-01

    Laparoscopic renal surgery is associated with reduced blood loss, shorter hospital stay, enhanced cosmesis, and more rapid convalescence relative to open renal surgery. Laparoscopic partial nephrectomy (LPN) is a minimally invasive, nephron-sparing alternative to laparoscopic radical nephrectomy (RN) for the management of small renal masses. While offering similar oncological outcomes to laparoscopic RN, the technical challenges and prolonged learning curve associated with LPN limit its wider dissemination. Robot-assisted partial nephrectomy (RAPN), although still an evolving procedure with no long-term data, has emerged as a viable alternative to LPN, with favorable preliminary outcomes. This article provides an overview of the role of RAPN in the management of renal cell carcinoma. The clinical indications and principles of surgical technique for this procedure are discussed. The oncological, renal functional, and perioperative outcomes of RAPN are also evaluated, as are complication rates.

  17. Active osmotic exchanger for advanced filtration at the nano scale

    Science.gov (United States)

    Marbach, Sophie; Bocquet, Lyderic

    2015-11-01

    One of the main functions of the kidney is to remove the waste products of an organism, mostly by excreting concentrated urea while reabsorbing water and other molecules. The human kidney is capable of recycling about 200 liters of water per day, at the relatively low cost of 0.5 kJ/L (standard dialysis requiring at least 150 kJ/L). Kidneys are constituted of millions of parallel filtration networks called nephrons. The nephrons of all mammalian kidneys present a specific loop geometry, the Loop of Henle, that is believed to play a key role in the urinary concentrating mechanism. One limb of the loop is permeable to water and the other contains sodium pumps that exchange with a common interstitium. In this work, we take inspiration from this osmotic exchanger design to propose new nanofiltration principles. We first establish simple analytical results to derive general operating principles, based on coupled water permeable pores and osmotic pumps. The best filtration geometry, in terms of power required for a given water recycling ratio, is comparable in many ways to the mammalian nephron. It is not only more efficient than traditional reverse osmosis systems, but can also work at much smaller pressures (of the order of the blood pressure, 0.13 bar, as compared to more than 30 bars for pressure-retarded osmosis systems). We anticipate that our proof of principle will be a starting point for the development of new filtration systems relying on the active osmotic exchanger principle.

  18. Conserved and Divergent Features of Human and Mouse Kidney Organogenesis.

    Science.gov (United States)

    Lindström, Nils O; McMahon, Jill A; Guo, Jinjin; Tran, Tracy; Guo, Qiuyu; Rutledge, Elisabeth; Parvez, Riana K; Saribekyan, Gohar; Schuler, Robert E; Liao, Christopher; Kim, Albert D; Abdelhalim, Ahmed; Ruffins, Seth W; Thornton, Matthew E; Basking, Laurence; Grubbs, Brendan; Kesselman, Carl; McMahon, Andrew P

    2018-03-01

    Human kidney function is underpinned by approximately 1,000,000 nephrons, although the number varies substantially, and low nephron number is linked to disease. Human kidney development initiates around 4 weeks of gestation and ends around 34-37 weeks of gestation. Over this period, a reiterative inductive process establishes the nephron complement. Studies have provided insightful anatomic descriptions of human kidney development, but the limited histologic views are not readily accessible to a broad audience. In this first paper in a series providing comprehensive insight into human kidney formation, we examined human kidney development in 135 anonymously donated human kidney specimens. We documented kidney development at a macroscopic and cellular level through histologic analysis, RNA in situ hybridization, immunofluorescence studies, and transcriptional profiling, contrasting human development (4-23 weeks) with mouse development at selected stages (embryonic day 15.5 and postnatal day 2). The high-resolution histologic interactive atlas of human kidney organogenesis generated can be viewed at the GUDMAP database (www.gudmap.org) together with three-dimensional reconstructions of key components of the data herein. At the anatomic level, human and mouse kidney development differ in timing, scale, and global features such as lobe formation and progenitor niche organization. The data also highlight differences in molecular and cellular features, including the expression and cellular distribution of anchor gene markers used to identify key cell types in mouse kidney studies. These data will facilitate and inform in vitro efforts to generate human kidney structures and comparative functional analyses across mammalian species. Copyright © 2018 by the American Society of Nephrology.

  19. Crioterapia de tumores renales: estado actual y desarrollos contemporáneos [= Cryotherapy for renal tumors: Current status and contemporary developments

    NARCIS (Netherlands)

    Rioja, J.; Tzortzis, V.; Mamoulakis, C.; Laguna, M. P.

    2010-01-01

    The proportion of renal tumors found incidentally dramatically increased in the past decade. More than half of them were diagnosed in patients over 70 years of age, a population with high associated comorbidity. Nephron-sparing minimally invasive surgical procedures are aimed at treating patients

  20. The Somatic Genomic Landscape of Chromophobe Renal Cell Carcinoma

    NARCIS (Netherlands)

    Davis, Caleb F; Ricketts, Christopher J; Wang, Min; Yang, Lixing; Cherniack, Andrew D; Shen, Hui; Buhay, Christian; Kang, Hyojin; Kim, Sang Cheol; Fahey, Catherine C; Hacker, Kathryn E; Bhanot, Gyan; Gordenin, Dmitry A; Chu, Andy; Gunaratne, Preethi H; Biehl, Michael; Seth, Sahil; Kaipparettu, Benny A; Bristow, Christopher A; Donehower, Lawrence A; Wallen, Eric M; Smith, Angela B; Tickoo, Satish K; Tamboli, Pheroze; Reuter, Victor; Schmidt, Laura S; Hsieh, James J; Choueiri, Toni K; Hakimi, A Ari; Chin, Lynda; Meyerson, Matthew; Kucherlapati, Raju; Park, Woong-Yang; Robertson, A Gordon; Laird, Peter W; Henske, Elizabeth P; Kwiatkowski, David J; Park, Peter J; Morgan, Margaret; Shuch, Brian; Muzny, Donna; Wheeler, David A; Linehan, W Marston; Gibbs, Richard A; Rathmell, W Kimryn; Creighton, Chad J

    2014-01-01

    We describe the landscape of somatic genomic alterations of 66 chromophobe renal cell carcinomas (ChRCCs) on the basis of multidimensional and comprehensive characterization, including mtDNA and whole-genome sequencing. The result is consistent that ChRCC originates from the distal nephron compared

  1. Surface science techniques

    CERN Document Server

    Bracco, Gianangelo

    2013-01-01

    The book describes the experimental techniques employed to study surfaces and interfaces. The emphasis is on the experimental method. Therefore all chapters start with an introduction of the scientific problem, the theory necessary to understand how the technique works and how to understand the results. Descriptions of real experimental setups, experimental results at different systems are given to show both the strength and the limits of the technique. In a final part the new developments and possible extensions of the techniques are presented. The included techniques provide microscopic as well as macroscopic information. They cover most of the techniques used in surface science.

  2. La chirurgie conservatrice dans le cancer du rein

    African Journals Online (AJOL)

    A. Qarro

    Renal cancer;. Conservative surgery;. Nephron-sparing;. Clamping;. Cold ischemia. Conservative surgery in kidney cancer. Abstract. Kidney cancer accounts for 3% of cancers. It ranks third in urological cancers after prostate and bladder cancers. Since the radical nephrectomy described by Robson in 1963, there has been ...

  3. Nephrogenic adenoma. Reports of two cases

    DEFF Research Database (Denmark)

    Osther, P J; Starklint, H

    1989-01-01

    Nephrogenic adenoma is a rare lesion of the urinary tract. Two cases in the urinary bladder are described. Histologically the tumor consists of cystic and tubular structures resembling the distal part of the nephron. The etiology and pathogenesis are discussed and a new etiologic theory is presen...

  4. Urinary collagen IV and πGST: potential biomarkers for detecting localized kidney injury in diabetes--a pilot study.

    LENUS (Irish Health Repository)

    Cawood, T J

    2010-01-01

    Urinary biomarkers can identify damage to specific parts of the nephron. We performed a cross-sectional study to characterise the pattern of diabetic nephropathy using urinary biomarkers of glomerular fibrosis (collagen IV), proximal tubular damage (α-glutathione-S-transferase, GST) and distal tubular damage (πGST).

  5. TRPV4 is associated with central rather than nephrogenic osmoregulation.

    NARCIS (Netherlands)

    Janas, S.; Seghers, F.; Schakman, O.; Alsady, M.; Deen, P.M.; Vriens, J.; Tissir, F.; Nilius, B.; Loffing, J.; Gailly, P.; Devuyst, O.

    2016-01-01

    TRPV4 is a polymodal cation channel expressed in osmosensitive neurons of the hypothalamus and in the mammalian nephron. The segmental distribution and role(s) of TRPV4 in osmoregulation remain debated. We investigated the renal distribution pattern of TRPV4 and the functional consequences of its

  6. New tides: using zebrafish to study renal regeneration.

    Science.gov (United States)

    McCampbell, Kristen K; Wingert, Rebecca A

    2014-02-01

    Over the past several decades, the zebrafish has become one of the major vertebrate model organisms used in biomedical research. In this arena, the zebrafish has emerged as an applicable system for the study of kidney diseases and renal regeneration. The relevance of the zebrafish model for nephrology research has been increasingly appreciated as the understanding of zebrafish kidney structure, ontogeny, and the response to damage has steadily expanded. Recent studies have documented the amazing regenerative characteristics of the zebrafish kidney, which include the ability to replace epithelial populations after acute injury and to grow new renal functional units, termed nephrons. Here we discuss how nephron composition is conserved between zebrafish and mammals, and highlight how recent findings from zebrafish studies utilizing transgenic technologies and chemical genetics can complement traditional murine approaches in the effort to dissect how the kidney responds to acute damage and identify therapeutics that enhance human renal regeneration. Copyright © 2014 Mosby, Inc. All rights reserved.

  7. Update on contemporary management of clinically localized renal cell carcinoma.

    Science.gov (United States)

    Jorns, J J; Thiel, D D; Castle, E P

    2012-12-01

    Renal cell carcinoma (RCC) continues to increase in incidence with the largest increase manifesting in small, organ-confined tumors. This review outlines the epidemiology and current data pertaining to the management of clinically-localized RCC. In this manuscript, the current data outlining the benefit of nephron sparing to the overall survival of the patient is described. The data pertaining to minimally invasive nephron sparing is also explained in detail. From laparoscopic and robotic partial nephrectomy to watchful waiting and percutaneous ablation, the urologist is continually assaulted with new data for the management of clinically-localized RCC. The data can be confusing, and much of it is conflicting. The addition of new scoring systems or nomograms may aid in predicting which therapy would be most beneficial in certain patient groups. New scoring systems may also predict the difficulty of surgical resection and predict surgical complications. The limitations of the data pertaining to the management of clinically-localized RCC are also outlined.

  8. Role of renal sympathetic nerve activity in prenatal programming of hypertension.

    Science.gov (United States)

    Baum, Michel

    2018-03-01

    Prenatal insults, such as maternal dietary protein deprivation and uteroplacental insufficiency, lead to small for gestational age (SGA) neonates. Epidemiological studies from many different parts of the world have shown that SGA neonates are at increased risk for hypertension and early death from cardiovascular disease as adults. Animal models, including prenatal administration of dexamethasone, uterine artery ligation and maternal dietary protein restriction, result in SGA neonates with fewer nephrons than controls. These models are discussed in this educational review, which provides evidence that prenatal insults lead to altered sodium transport in multiple nephron segments. The factors that could result in increased sodium transport are discussed, focusing on new information that there is increased renal sympathetic nerve activity that may be responsible for augmented renal tubular sodium transport. Renal denervation abrogates the hypertension in programmed rats but has no effect on control rats. Other potential factors that could cause hypertension in programmed rats, such as the renin-angiotensin system, are also discussed.

  9. Decomposition techniques

    Science.gov (United States)

    Chao, T.T.; Sanzolone, R.F.

    1992-01-01

    Sample decomposition is a fundamental and integral step in the procedure of geochemical analysis. It is often the limiting factor to sample throughput, especially with the recent application of the fast and modern multi-element measurement instrumentation. The complexity of geological materials makes it necessary to choose the sample decomposition technique that is compatible with the specific objective of the analysis. When selecting a decomposition technique, consideration should be given to the chemical and mineralogical characteristics of the sample, elements to be determined, precision and accuracy requirements, sample throughput, technical capability of personnel, and time constraints. This paper addresses these concerns and discusses the attributes and limitations of many techniques of sample decomposition along with examples of their application to geochemical analysis. The chemical properties of reagents as to their function as decomposition agents are also reviewed. The section on acid dissolution techniques addresses the various inorganic acids that are used individually or in combination in both open and closed systems. Fluxes used in sample fusion are discussed. The promising microwave-oven technology and the emerging field of automation are also examined. A section on applications highlights the use of decomposition techniques for the determination of Au, platinum group elements (PGEs), Hg, U, hydride-forming elements, rare earth elements (REEs), and multi-elements in geological materials. Partial dissolution techniques used for geochemical exploration which have been treated in detail elsewhere are not discussed here; nor are fire-assaying for noble metals and decomposition techniques for X-ray fluorescence or nuclear methods be discussed. ?? 1992.

  10. Translation Techniques

    OpenAIRE

    Marcia Pinheiro

    2015-01-01

    In this paper, we discuss three translation techniques: literal, cultural, and artistic. Literal translation is a well-known technique, which means that it is quite easy to find sources on the topic. Cultural and artistic translation may be new terms. Whilst cultural translation focuses on matching contexts, artistic translation focuses on matching reactions. Because literal translation matches only words, it is not hard to find situations in which we should not use this technique.  Because a...

  11. Pattern of trypan blue storage in the chick embryonic kidney reflects development of absorptive capacity of the proximal tubules

    Czech Academy of Sciences Publication Activity Database

    Zemanová, Zdeňka

    2004-01-01

    Roč. 15, č. 3-4 (2004), s. 160-165 ISSN 1470-2061 R&D Projects: GA ČR GA304/04/0972 Institutional research plan: CEZ:AV0Z5011922 Keywords : chick embryo * mesonephric nephrons * trypan blue Subject RIV: ED - Physiology Impact factor: 0.724, year: 2004

  12. [Is this the end for double RAAS inhibition?

    NARCIS (Netherlands)

    Deinum, J.

    2014-01-01

    Recently, the VA NEPHRON-D study was stopped early due to insignificant effects and increased adverse events. This was the last in a series of trials on the value of dual versus single blockade of the renin-angiotensin-aldosterone system in patients at risk for renal or cardiovascular complications.

  13. Inhibition of insulin-stimulated hydrogen peroxide production prevents stimulation of sodium transport in A6 cell monolayers.

    NARCIS (Netherlands)

    Markadieu, N.Y.G.; Crutzen, R.; Boom, A.; Erneux, C.; Beauwens, R.

    2009-01-01

    Insulin-stimulated sodium transport across A6 cell (derived from amphibian distal nephron) monolayers involves the activation of a phosphatidylinositol (PI) 3-kinase. We previously demonstrated that exogenous addition of H2O2 to the incubation medium of A6 cell monolayers provokes an increase in PI

  14. Aging and the Disposition and Toxicity of Mercury in Rats

    Science.gov (United States)

    Bridges, Christy C.; Joshee, Lucy; Zalups, Rudolfs K.

    2014-01-01

    Progressive loss of functioning nephrons, secondary to age-related glomerular disease, can impair the ability of the kidneys to effectively clear metabolic wastes and toxicants from blood. Additionally, as renal mass is diminished, cellular hypertrophy occurs in functional nephrons that remain. We hypothesize that these nephrons are exposed to greater levels of nephrotoxicants, such as inorganic mercury (Hg2+), and thus are at an increased risk of becoming intoxicated by these compounds. The purpose of the present study was to characterize the effects of aging on the disposition and renal toxicity of Hg2+ in young adult and aged Wistar rats. Paired groups of animals were injected (i.v.) with either a 0.5 μmol • kg−1 non-nephrotoxic or a 2.5 μmol • kg−1 nephrotoxic dose of mercuric chloride (HgCl2). Plasma creatinine and renal biomarkers of proximal tubular injury were greater in both groups of aged rats than in the corresponding groups of young adult rats. Histologically, evidence of glomerular sclerosis, tubular atrophy, interstitial inflammation and fibrosis were significant features of kidneys from aged animals. In addition, proximal tubular necrosis, especially along the straight segments in the inner cortex and outer stripe of the outer medulla was a prominent feature in the renal sections from both aged and young rats treated with the nephrotoxic dose of HgCl2. Our findings indicate 1) that overall renal function is significantly impaired in aged rats, resulting in chronic renal insufficiency and 2) the disposition of HgCl2 in aging rats is significantly altered compared to that of young rats. PMID:24548775

  15. Neonatal irradiation nephropathy in the growing dog. I. Renal morphological and functional adaptations following neonatal, sublethal, whole-body irradiation

    International Nuclear Information System (INIS)

    Wilke, W.L.; Phemister, R.D.; Jaenke, R.S.

    1979-01-01

    Sixty beagles were used to study the effects of exposure to 330 R 60 Co γ radiation (bilateral, whole-body) at 2 days of age on renal functional and morphological development in the growing dog. A significant deficit in grams kidney per kilogram body weight was found in irradiated dogs at 50 days of age (P < 0.05), but not at 125 or 200 days of age. Glomerular filtration rate (GFR) per kilogram body weight and GFR per gram kidney were not significantly different between irradiated and nonirradiated dogs at 50, 125, or 200 days of age, but blood urea nitrogen (BUN) was significantly elevated in irradiated dogs throughout this period (P < 0.05). The fractional distribution of intracortical renal blood flow, as determined by radiolabeled microspheres, to the outermost cortex was found to be reduced in irradiated animals at all ages evaluated (P < 0.05). The fractional blood flow to the outermost renal cortex was negatively correlated with BUN in both irradiated (P < 0.05) and nonirradiated (P < 0.05) animals. Based on prior demonstrations of reductions in nephron numbers following similar irradiation, these data indicate increases in mean single nephron GFR and nephronal hypertrophy in the kidneys of the neonatally irradiated dog. The renal functional and morphological adaptations are sufficient to maintain adequate renal function in growing, neonatally irradiated dogs. The BUN elevations in irradiated dogs are believed to be related to changes in intracortical renal blood flow, rather than indicating renal insufficiency. The possible importance of the functional and morphological adaptations to the subsequent development of chronic renal failure in neonatally irradiated animals is discussed

  16. Aging and the disposition and toxicity of mercury in rats.

    Science.gov (United States)

    Bridges, Christy C; Joshee, Lucy; Zalups, Rudolfs K

    2014-05-01

    Progressive loss of functioning nephrons, secondary to age-related glomerular disease, can impair the ability of the kidneys to effectively clear metabolic wastes and toxicants from blood. Additionally, as renal mass is diminished, cellular hypertrophy occurs in functional nephrons that remain. We hypothesize that these nephrons are exposed to greater levels of nephrotoxicants, such as inorganic mercury (Hg(2+)), and thus are at an increased risk of becoming intoxicated by these compounds. The purpose of the present study was to characterize the effects of aging on the disposition and renal toxicity of Hg(2+) in young adult and aged Wistar rats. Paired groups of animals were injected (i.v.) with either a 0.5μmol·kg(-1) non-nephrotoxic or a 2.5μmol·kg(-1) nephrotoxic dose of mercuric chloride (HgCl2). Plasma creatinine and renal biomarkers of proximal tubular injury were greater in both groups of aged rats than in the corresponding groups of young adult rats. Histologically, evidence of glomerular sclerosis, tubular atrophy, interstitial inflammation and fibrosis were significant features of kidneys from aged animals. In addition, proximal tubular necrosis, especially along the straight segments in the inner cortex and outer stripe of the outer medulla was a prominent feature in the renal sections from both aged and young rats treated with the nephrotoxic dose of HgCl2. Our findings indicate 1) that overall renal function is significantly impaired in aged rats, resulting in chronic renal insufficiency and 2) the disposition of HgCl2 in aging rats is significantly altered compared to that of young rats. Copyright © 2014 Elsevier Inc. All rights reserved.

  17. Osr1 Interacts Synergistically with Wt1 to Regulate Kidney Organogenesis.

    Directory of Open Access Journals (Sweden)

    Jingyue Xu

    Full Text Available Renal hypoplasia is a common cause of pediatric renal failure and several adult-onset diseases. Recent studies have associated a variant of the OSR1 gene with reduction of newborn kidney size and function in heterozygotes and neonatal lethality with kidney defects in homozygotes. How OSR1 regulates kidney development and nephron endowment is not well understood, however. In this study, by using the recently developed CRISPR genome editing technology, we genetically labeled the endogenous Osr1 protein and show that Osr1 interacts with Wt1 in the developing kidney. Whereas mice heterozygous for either an Osr1 or Wt1 null allele have normal kidneys at birth, most mice heterozygous for both Osr1 and Wt1 exhibit defects in metanephric kidney development, including unilateral or bilateral kidney agenesis or hypoplasia. The developmental defects in the Osr1+/-Wt1+/- mouse embryos were detected as early as E10.5, during specification of the metanephric mesenchyme, with the Osr1+/-Wt1+/- mouse embryos exhibiting significantly reduced Pax2-positive and Six2-positive nephron progenitor cells. Moreover, expression of Gdnf, the major nephrogenic signal for inducing ureteric bud outgrowth, was significantly reduced in the metanephric mesenchyme in Osr1+/-Wt1+/- embryos in comparison with the Osr1+/- or Wt1+/- littermates. By E11.5, as the ureteric buds invade the metanephric mesenchyme and initiate branching morphogenesis, kidney morphogenesis was significantly impaired in the Osr1+/-Wt1+/- embryos in comparison with the Osr1+/- or Wt1+/- embryos. These results indicate that Osr1 and Wt1 act synergistically to regulate nephron endowment by controlling metanephric mesenchyme specification during early nephrogenesis.

  18. Specific radiography technique

    International Nuclear Information System (INIS)

    Abdul Nassir Ibrahim; Azali Muhammad; Ab. Razak Hamzah; Abd. Aziz Mohamed; Mohamad Pauzi Ismail

    2008-01-01

    Beside radiography testing using x-ray machine and gamma source, there are several technique that developed specifically to complete the testing that cannot be done with the two earlier. This technique was specific based on several factor, for the example, the advantages of neutron and electron using to show the image was unique compare to x-ray and gamma. Besides that, these special radiography techniques maybe differ in how to detect the radiation get through the object. These technique can used to inspect thin or specimen that contained radioactive material. There are several technique will discussed in this chapter such as neutron radiography, electron radiography, fluoroscopy and also autoradiography.

  19. Mutational screening of PKD2 gene in the north Indian polycystic ...

    Indian Academy of Sciences (India)

    Sonam Raj

    2017-09-27

    Sep 27, 2017 ... Polycystic kidney disease (PKD) is a systemic disorder which adds majority of renal patients to end stage renal disease. ... This study was performed using PCR and automated DNA sequencing in 84 cases and .... protein is expressed in all segments of nephron except .... patient cohort from northern India.

  20. Outcome and renal function following salvage surgery for bilateral ...

    African Journals Online (AJOL)

    Chemotherapy followed by nephron-sparing surgery. (NSS) has become the ... 10 showed a mean. 24% decrease in tumor size following chemotherapy. .... month postoperatively (cases 1 and 3). The type of operation did not seem to correlate with the need for antihypertensives in our study as compared with the study by ...

  1. Point of Technique

    African Journals Online (AJOL)

    .

    Minimally invasive techniques are becoming popular choice for the recent times. These techniques are lowering the cost and giving the best cosmetic results. For cardiovascular surgery these techniques are much more newer and much more unknown. Open lumbar sympathectomy for certain indications is a very well ...

  2. Uranium exploration techniques

    International Nuclear Information System (INIS)

    Nichols, C.E.

    1984-01-01

    The subject is discussed under the headings: introduction (genetic description of some uranium deposits; typical concentrations of uranium in the natural environment); sedimentary host rocks (sandstones; tabular deposits; roll-front deposits; black shales); metamorphic host rocks (exploration techniques); geologic techniques (alteration features in sandstones; favourable features in metamorphic rocks); geophysical techniques (radiometric surveys; surface vehicle methods; airborne methods; input surveys); geochemical techniques (hydrogeochemistry; petrogeochemistry; stream sediment geochemistry; pedogeochemistry; emanometry; biogeochemistry); geochemical model for roll-front deposits; geologic model for vein-like deposits. (U.K.)

  3. Persian fencing techniques

    Directory of Open Access Journals (Sweden)

    Manouchehr Moshtagh Khorasani

    2012-07-01

    Full Text Available There are numerous manuscripts, poems and stories that describe, specifically and in detail, the different techniques used in Persian swordsmanship. The present article explains the origins and the techniques of Persian swordsmanship. The article also describes the traditional code of conduct for Persian warriors. Additionally, it describes an array of techniques that were deployed in actual combat in Iran’s history. Some of these techniques are represented via the miniatures that are reproduced herein. This is the first article on Persian swordsmanship published in any periodical.

  4. Radiation scattering techniques

    International Nuclear Information System (INIS)

    Edmonds, E.A.

    1986-01-01

    Radiation backscattering techniques are useful when access to an item to be inspected is restricted to one side. These techniques are very sensitive to geometrical effects. Scattering processes and their application to the determination of voids, thickness measuring, well-logging and the use of x-ray fluorescence techniques are discussed. (U.K.)

  5. Functional and histopathological changes in dog kidneys after administration of cisplatin

    DEFF Research Database (Denmark)

    Daugaard, G; Abildgaard, U; Larsen, S

    1987-01-01

    The nephrotoxic effect of cisplatin (5 mg/kg i.v.) was evaluated in 8 dogs 48-72 h after administration. The lithium clearance method was used for assessing the absolute and fractional reabsorption rates of sodium and water in proximal as well as in more distal segments of the total nephron popul...

  6. Beta-2-mikroglobulin ved medicinske sygdomme

    DEFF Research Database (Denmark)

    Hansen, P B; Olsen, Niels Vidiendal

    1989-01-01

    Beta-2-microglobulin (beta 2M) is a low-molecular protein which is filtered freely over the glomeruli. Under normal circumstances, more than 99.9% is resorbed in the proximal tubuli of the kidneys and is metabolized there. In renal disease with damage to this segment of the nephron, eg acute tubulo...

  7. Preference for different relaxation techniques by COPD patients: comparison between six techniques

    Directory of Open Access Journals (Sweden)

    Hyl

    2016-09-01

    Full Text Available Michael E Hyland,1 David MG Halpin,2 Sue Blake,3 Clare Seamark,3 Margaret Pinnuck,3 David Ward,3 Ben Whalley,1 Colin J Greaves,4 Adam L Hawkins,5 Dave Seamark3 1School of Psychology, University of Plymouth, Plymouth, 2Department of Respiratory Medicine, Royal Devon and Exeter Hospital, Exeter, 3Honiton Group Practice, Honiton, 4University of Exeter Medical School, Exeter, 5GSK House, Brentford, UK Background: A review of the effectiveness of relaxation techniques for chronic obstructive pulmonary disease patients has shown inconsistent results, but studies have varied in terms of technique and outcome measures. Aim: To determine patient preference for different relaxation techniques. Methods: Chronic obstructive pulmonary disease patients were presented with six techniques via a DVD and asked to rate the techniques in terms of effectiveness, rank in order of likely use, and comment. Results: Patients differed in the technique preferred and reason for that preference, but the most commonly preferred technique both for effectiveness and ease of use was “thinking of a nice place” followed by progressive relaxation and counting. Familiarity and ease of activity were commonly given reasons for preference. Conclusion: Rather than providing patients with a single technique that they might find difficult to implement, these results suggest that it would be better to give a choice. “Thinking of a nice place” is a popular but under-investigated technique. Keywords: COPD exacerbation, anxiety, relaxation techniques

  8. Training techniques for industry

    International Nuclear Information System (INIS)

    Jones, D.W.

    1978-01-01

    The advantages and disadvantages of commonly used training techniques in relation to cost-effective, prevention-oriented Quality Assurance are examined. Important questions are whether training techniques teach cost effectiveness and whether the techniques are, themselves, cost effective. To answer these questions, criteria for evaluating teaching techniques for cost effectiveness were developd, and then commonly used techniques are evaluated in terms of specific training program objectives. Motivation of personnel is also considered important to the success of a training program, and methods are outlined by which recognition of the academic quality of industrial training can be used as a motivational technique

  9. Organic anion and cation SLC22 "drug" transporter (Oat1, Oat3, and Oct1 regulation during development and maturation of the kidney proximal tubule.

    Directory of Open Access Journals (Sweden)

    Thomas F Gallegos

    Full Text Available Proper physiological function in the pre- and post-natal proximal tubule of the kidney depends upon the acquisition of selective permeability, apical-basolateral epithelial polarity and the expression of key transporters, including those involved in metabolite, toxin and drug handling. Particularly important are the SLC22 family of transporters, including the organic anion transporters Oat1 (originally identified as NKT and Oat3 as well as the organic cation transporter Oct1. In ex vivo cultures of metanephric mesenchyme (MM; the embryonic progenitor tissue of the nephron Oat function was evident before completion of nephron segmentation and corresponded with the maturation of tight junctions as measured biochemically by detergent extractability of the tight junction protein, ZO-1. Examination of available time series microarray data sets in the context of development and differentiation of the proximal tubule (derived from both in vivo and in vitro/ex vivo developing nephrons allowed for correlation of gene expression data to biochemically and functionally defined states of development. This bioinformatic analysis yielded a network of genes with connectivity biased toward Hnf4α (but including Hnf1α, hyaluronic acid-CD44, and notch pathways. Intriguingly, the Oat1 and Oat3 genes were found to have strong temporal co-expression with Hnf4α in the cultured MM supporting the notion of some connection between the transporters and this transcription factor. Taken together with the ChIP-qPCR finding that Hnf4α occupies Oat1, Oat3, and Oct1 proximal promoters in the in vivo differentiating rat kidney, the data suggest a network of genes with Hnf4α at its center plays a role in regulating the terminal differentiation and capacity for drug and toxin handling by the nascent proximal tubule of the kidney.

  10. Of mice and men: divergence of gene expression patterns in kidney.

    Directory of Open Access Journals (Sweden)

    Lydie Cheval

    Full Text Available Since the development of methods for homologous gene recombination, mouse models have played a central role in research in renal pathophysiology. However, many published and unpublished results show that mice with genetic changes mimicking human pathogenic mutations do not display the human phenotype. These functional differences may stem from differences in gene expression between mouse and human kidneys. However, large scale comparison of gene expression networks revealed conservation of gene expression among a large panel of human and mouse tissues including kidneys. Because renal functions result from the spatial integration of elementary processes originating in the glomerulus and the successive segments constituting the nephron, we hypothesized that differences in gene expression profiles along the human and mouse nephron might account for different behaviors. Analysis of SAGE libraries generated from the glomerulus and seven anatomically defined nephron segments from human and mouse kidneys allowed us to identify 4644 pairs of gene orthologs expressed in either one or both species. Quantitative analysis shows that many transcripts are present at different levels in the two species. It also shows poor conservation of gene expression profiles, with less than 10% of the 4644 gene orthologs displaying a higher conservation of expression profiles than the neutral expectation (p<0.05. Accordingly, hierarchical clustering reveals a higher degree of conservation of gene expression patterns between functionally unrelated kidney structures within a given species than between cognate structures from the two species. Similar findings were obtained for sub-groups of genes with either kidney-specific or housekeeping functions. Conservation of gene expression at the scale of the whole organ and divergence at the level of its constituting sub-structures likely account for the fact that although kidneys assume the same global function in the two species

  11. Effect of Dietary Countermeasures and Impact of Gravity on Renal Calculi Size Distributions Predicted by PBE-System and PBE-CFD Models

    Science.gov (United States)

    Kassemi, M.; Thompson, D.; Goodenow, D.; Gokoglu, S.; Myers, J.

    2016-01-01

    Renal stone disease is not only a concern on earth but can conceivably pose a serious risk to the astronauts health and safety in Space. In this work, two different deterministic models based on a Population Balance Equation (PBE) analysis of renal stone formation are developed to assess the risks of critical renal stone incidence for astronauts during space travel. In the first model, the nephron is treated as a continuous mixed suspension mixed product removal crystallizer and the PBE for the nucleating, growing and agglomerating renal calculi is coupled to speciation calculations performed by JESS. Predictions of stone size distributions in the kidney using this model indicate that the astronaut in microgravity is at noticeably greater but still subcritical risk and recommend administration of citrate and augmented hydration as effective means of minimizing and containing this risk. In the second model, the PBE analysis is coupled to a Computational Fluid Dynamics (CFD) model for flow of urine and transport of Calcium and Oxalate in the nephron to predict the impact of gravity on the stone size distributions. Results presented for realistic 3D tubule and collecting duct geometries, clearly indicate that agglomeration is the primary mode of size enhancement in both 1g and microgravity. 3D numerical simulations seem to further indicate that there will be an increased number of smaller stones developed in microgravity that will likely pass through the nephron in the absence of wall adhesion. However, upon reentry to a 1g (Earth) or 38g (Mars) partial gravitational fields, the renal calculi can lag behind the urinary flow in tubules that are adversely oriented with respect to the gravitational field and grow agglomerate to large sizes that are sedimented near the wall with increased propensity for wall adhesion, plaque formation, and risk to the astronauts.

  12. Treatment options for renal cell carcinoma in renal allografts: a case series from a single institution.

    Science.gov (United States)

    Swords, Darden C; Al-Geizawi, Samer M; Farney, Alan C; Rogers, Jeffrey; Burkart, John M; Assimos, Dean G; Stratta, Robert J

    2013-01-01

    Renal cell carcinoma (RCC) is more common in renal transplant and dialysis patients than the general population. However, RCC in transplanted kidneys is rare, and treatment has previously consisted of nephrectomy with a return to dialysis. There has been recent interest in nephron-sparing procedures as a treatment option for RCC in allograft kidneys in an effort to retain allograft function. Four patients with RCC in allograft kidneys were treated with nephrectomy, partial nephrectomy, or radiofrequency ablation. All of the patients are without evidence of recurrence of RCC after treatment. We found nephron-sparing procedures to be reasonable initial options in managing incidental RCCs diagnosed in functioning allografts to maintain an improved quality of life and avoid immediate dialysis compared with radical nephrectomy of a functioning allograft. However, in non-functioning renal allografts, radical nephrectomy may allow for a higher chance of cure without the loss of transplant function. Consequently, radical nephrectomy should be utilized whenever the allograft is non-functioning and the patient's surgical risk is not prohibitive. © 2013 John Wiley & Sons A/S.

  13. Renal echo-3D and microalbuminuria in children of diabetic mothers: a preliminary study.

    Science.gov (United States)

    Cappuccini, B; Torlone, E; Ferri, C; Arnone, S; Troiani, S; Bini, V; Bellomo, G; Barboni, G; Di Renzo, G

    2013-08-01

    Maternal diabetes has assumed epidemic relevance in recent years and animal studies have provided some evidence that it may cause abnormalities in renal development and a reduction in nephron endowment in the offspring; however, human data are lacking. The renal cortex contains ∼95% of the glomeruli and its volume could be taken as a surrogate measure of glomerular number; based on this assumption, we measured renal cortex volume and in addition, microalbuminuria in a homogeneous sample of 42 children of diabetic (pregestational, n = 13, and gestational, n = 29) mothers, compared with 21 healthy children born of non-diabetic mothers. The offspring of diabetic mothers showed a significant reduction of renal cortex volume and higher albumin excretion compared with controls, possibly attributable to a reduction in the number of nephrons and the difference was statistically significant (P < 0.001). Although further studies on a larger sample are necessary, our preliminary findings suggest that maternal diabetes may affect renal development with sequelae later in life, requiring closer monitoring and follow-up. Furthermore, the importance of strict maternal diabetes management and control must be emphasized.

  14. Diuretics in the treatment of hypertension. Part 2: loop diuretics and potassium-sparing agents.

    Science.gov (United States)

    Tamargo, Juan; Segura, Julian; Ruilope, Luis M

    2014-04-01

    Diuretics enhance the renal excretion of Na(+) and water due to a direct action at different tubular sites of the nephron where solute re-absorption occurs. This paper focuses on the mechanism of action, pharmacodynamics, antihypertensive effects, adverse effects, interactions and contraindications of loop diuretics and potassium-sparing agents (including mineralocorticoid receptor antagonists (MRAs) and epithelial Na(+) channel blockers). Loop diuretics are less effective than thiazide diuretics in lowering blood pressure, so that their major use is in edematous patients with congestive heart failure (HF), cirrhosis with ascites and nephritic edema. MRAs represent a major advance in the treatment of resistant hypertension, primary and secondary hyperaldosteronism and in patients with systolic HF to reduce the risks of hospitalization and of premature death. Potassium-sparing diuretics when coadministered with diuretics (thiazides and loop diuretics) working at more proximal nephron locations reduce the risk of hypokalemia and hypomagnesemia and the risk of cardiac arrhythmias. At the end of the article, the basis for the combination of diuretics with other antihypertensive drugs to achieve blood pressure targets is presented.

  15. Asymmetric BMP4 signalling improves the realism of kidney organoids.

    Science.gov (United States)

    Mills, Christopher G; Lawrence, Melanie L; Munro, David A D; Elhendawi, Mona; Mullins, John J; Davies, Jamie A

    2017-11-01

    We present a strategy for increasing the anatomical realism of organoids by applying asymmetric cues to mimic spatial information that is present in natural embryonic development, and demonstrate it using mouse kidney organoids. Existing methods for making kidney organoids in mice yield developing nephrons arranged around a symmetrical collecting duct tree that has no ureter. We use transplant experiments to demonstrate plasticity in the fate choice between collecting duct and ureter, and show that an environment rich in BMP4 promotes differentiation of early collecting ducts into uroplakin-positive, unbranched, ureter-like epithelial tubules. Further, we show that application of BMP4-releasing beads in one place in an organoid can break the symmetry of the system, causing a nearby collecting duct to develop into a uroplakin-positive, broad, unbranched, ureter-like 'trunk' from one end of which true collecting duct branches radiate and induce nephron development in an arrangement similar to natural kidneys. The idea of using local symmetry-breaking cues to improve the realism of organoids may have applications to organoid systems other than the kidney.

  16. Robot-assisted partial nephrectomy in contemporary practice

    Directory of Open Access Journals (Sweden)

    Youssef S. Tanagho

    2013-01-01

    Full Text Available Laparoscopic renal surgery is associated with reduced blood loss, shorter hospital stay, enhanced cosmesis, and more rapid convalescence relative to open renal surgery. Laparoscopic partial nephrectomy is a minimally invasive, nephron-sparing alternative to laparoscopic radical nephrectomy for the management of small renal masses. While offering similar oncological outcomes to laparoscopic radical nephrectomy, the technical challenges and prolonged learning curve associated with laparoscopic partial nephrectomy limit its wider dissemination. Robot-assisted partial nephrectomy, although still an evolving procedure with no long-term data, has emerged as a viable alternative to laparoscopic partial nephrectomy, with favorable preliminary outcomes. This article provides an overview of the role of robot-assisted partial nephrectomy in the management of renal cell carcinoma. The clinical indications and principles of surgical technique for this procedure are discussed. The oncological, renal functional, and perioperative outcomes of robot-assisted partial nephrectomy are also evaluated, as are complication rates.

  17. Pulse holographic measurement techniques

    International Nuclear Information System (INIS)

    Kim, Cheol Jung; Baik, Seong Hoon; Hong, Seok Kyung; Kim, Jeong Moog; Kim, Duk Hyun

    1992-01-01

    With the development of laser, remote inspection techniques using laser have been growing on. The inspection and measurement techniques by pulse holography are well-established technique for precise measurement, and widely used in various fields of industry now. In nuclear industry, this technology is practically used because holographic inspection is remote, noncontact, and precise measurement technique. In relation to remote inspection technology in nuclear industry, state-of-the art of pulse HNDT (Holographic non-destructive testing) and holographic measurement techniques are examined. First of all, the fundamental principles as well as practical problems for applications are briefly described. The fields of pulse holography have been divided into the HNDT, flow visualization and distribution study, and other application techniques. Additionally holographic particle study, bubble chamber holography, and applications to other visualization techniques are described. Lastly, the current status for the researches and applications of pulse holography to nuclear industry which are carried out actively in Europe and USA, is described. (Author)

  18. SEM-based characterization techniques

    International Nuclear Information System (INIS)

    Russell, P.E.

    1986-01-01

    The scanning electron microscope is now a common instrument in materials characterization laboratories. The basic role of the SEM as a topographic imaging system has steadily been expanding to include a variety of SEM-based analytical techniques. These techniques cover the range of basic semiconductor materials characterization to live-time device characterization of operating LSI or VLSI devices. This paper introduces many of the more commonly used techniques, describes the modifications or additions to a conventional SEM required to utilize the techniques, and gives examples of the use of such techniques. First, the types of signals available from a sample being irradiated by an electron beam are reviewed. Then, where applicable, the type of spectroscopy or microscopy which has evolved to utilize the various signal types are described. This is followed by specific examples of the use of such techniques to solve problems related to semiconductor technology. Techniques emphasized include: x-ray fluorescence spectroscopy, electron beam induced current (EBIC), stroboscopic voltage analysis, cathodoluminescnece and electron beam IC metrology. Current and future trends of some of the these techniques, as related to the semiconductor industry are discussed

  19. Nuclear techniques in hydrology

    International Nuclear Information System (INIS)

    Moser, H.

    1976-01-01

    The nuclear techniques used in hydrology are usually tracer techniques based on the use of nuclides either intentionally introduced into, or naturally present in the water. The low concentrations of these nuclides, which must be detected in groundwater and surface water, require special measurement techniques for the concentrations of radioactive or of stable nuclides. The nuclear techniques can be used most fruitfully in conjunction with conventional methods for the solution of problems in the areas of hydrology, hydrogeology and glacier hydrology. Nuclear techniques are used in practice in the areas of prospecting for water, environment protection and engineering hydrogeology. (orig.) [de

  20. Aquaporin-2 excretion in hospitalized patients with cirrhosis

    DEFF Research Database (Denmark)

    Busk, Troels M; Møller, Søren; Pedersen, Erling B.

    2017-01-01

    Background and Aim: Urinary aquaporin-2 (AQP2) is a parameter of water transport in the principal cells in the distal part of the nephron and involved in water retention in cirrhosis and may be a marker of renal function. The aim of the study was to evaluate AQP2 as a predictor of renal insuffici...

  1. Phase multistability of self-modulated oscillations

    DEFF Research Database (Denmark)

    Sosnovtseva, Olga; Postnov, D.E.; Nekrasov, A.M.

    2002-01-01

    The paper examines the type of multistability that one can observe in the synchronization of two oscillators when the systems individually display self-modulation or other types of multicrest wave forms. The investigation is based on a phase reduction method and on the calculation of phase maps...... nonlinearity and a biologically motivated model of nephron autoregulation are presented....

  2. [Prescribing diuretics: what a practitioner needs to know].

    Science.gov (United States)

    Richard, C; Saudan, P; Ernandez, T

    2015-02-25

    Diuretics are among the most frequently prescribed drugs. Most of them act by inhibiting sodium reabsorption in various nephron segments. By understanding their pharmacological characteristics, it is possible to adapt the type of diuretic to different clinical situations. Practical aspects of their use, including in heart failure, cirrhosis, the nephrotic syndrome and renal failure, are discussed.

  3. Protaper--hybrid technique.

    Science.gov (United States)

    Simon, Stephane; Lumley, Philip; Tomson, Phillip; Pertot, Wilhelm-Joseph; Machtou, Pierre

    2008-03-01

    Crown down preparation is the most known and described technique since the introduction of Nickel Titanium (NiTi) rotary instruments in endodontics. This technique gives good results but has limitations, such as not addressing the initial anatomy of oval or dumb-bell shaped canals. The specific design of the Protaper instruments allows use of them with a different technique and, specifically, with a brushing motion in the body of the canal. The recent introduction of hand Protaper files has expanded the range of application of this system, especially in curved canals. The 'hybrid technique', using rotary and hand files, and the advantages of the combination of both instruments, are clearly described in this article. Used with this technique, the Protaper is a very safe system to use, and more controllable, for both inexperienced and experienced practitioners alike, than other systems. To understand the precautions needed with rotary files, and how to use them to preserve the anatomy of the canal and get a tapered shaping, even in severely curved canals.

  4. Low current beam techniques

    Energy Technology Data Exchange (ETDEWEB)

    Saint, A.; Laird, J.S.; Bardos, R.A.; Legge, G.J.F. [Melbourne Univ., Parkville, VIC (Australia). School of Physics; Nishijima, T.; Sekiguchi, H. [Electrotechnical Laboratory, Tsukuba (Japan).

    1993-12-31

    Since the development of Scanning Transmission Microscopy (STIM) imaging in 1983 many low current beam techniques have been developed for the scanning (ion) microprobe. These include STIM tomography, Ion Beam Induced Current, Ion Beam Micromachining and Microlithography and Ionoluminense. Most of these techniques utilise beam currents of 10{sup -15} A down to single ions controlled by beam switching techniques This paper will discuss some of the low beam current techniques mentioned above, and indicate, some of their recent applications at MARC. A new STIM technique will be introduced that can be used to obtain Z-contrast with STIM resolution. 4 refs., 3 figs.

  5. Low current beam techniques

    Energy Technology Data Exchange (ETDEWEB)

    Saint, A; Laird, J S; Bardos, R A; Legge, G J.F. [Melbourne Univ., Parkville, VIC (Australia). School of Physics; Nishijima, T; Sekiguchi, H [Electrotechnical Laboratory, Tsukuba (Japan).

    1994-12-31

    Since the development of Scanning Transmission Microscopy (STIM) imaging in 1983 many low current beam techniques have been developed for the scanning (ion) microprobe. These include STIM tomography, Ion Beam Induced Current, Ion Beam Micromachining and Microlithography and Ionoluminense. Most of these techniques utilise beam currents of 10{sup -15} A down to single ions controlled by beam switching techniques This paper will discuss some of the low beam current techniques mentioned above, and indicate, some of their recent applications at MARC. A new STIM technique will be introduced that can be used to obtain Z-contrast with STIM resolution. 4 refs., 3 figs.

  6. Applications of Electromigration Techniques: Applications of Electromigration Techniques in Food Analysis

    Science.gov (United States)

    Wieczorek, Piotr; Ligor, Magdalena; Buszewski, Bogusław

    Electromigration techniques, including capillary electrophoresis (CE), are widely used for separation and identification of compounds present in food products. These techniques may also be considered as alternate and complementary with respect to commonly used analytical techniques, such as high-performance liquid chromatography (HPLC), or gas chromatography (GC). Applications of CE concern the determination of high-molecular compounds, like polyphenols, including flavonoids, pigments, vitamins, food additives (preservatives, antioxidants, sweeteners, artificial pigments) are presented. Also, the method developed for the determination of proteins and peptides composed of amino acids, which are basic components of food products, are studied. Other substances such as carbohydrates, nucleic acids, biogenic amines, natural toxins, and other contaminations including pesticides and antibiotics are discussed. The possibility of CE application in food control laboratories, where analysis of the composition of food and food products are conducted, is of great importance. CE technique may be used during the control of technological processes in the food industry and for the identification of numerous compounds present in food. Due to the numerous advantages of the CE technique it is successfully used in routine food analysis.

  7. Spectrometric techniques 4

    CERN Document Server

    Vanasse, George A

    2013-01-01

    Spectrometric Techniques, Volume IV discusses three widely diversified areas of spectrometric techniques. The book focuses on three spectrometric methods. Chapter 1 discusses the phenomenology and applications of Coherent Anti-Stokes Raman Spectroscopy (CARS), the most commonly used optical technique that exploit the Raman effect. The second chapter is concerned with diffraction gratings and mountings for the Vacuum Ultraviolet Spectral Region. Chapter 3 accounts the uses of mass spectrometry, detectors, types of spectrometers, and ion sources. Physicists and chemists will find the book a go

  8. Spectrometric techniques 2

    CERN Document Server

    Vanasse, George A

    2013-01-01

    Spectrometric Techniques, Volume II provides information pertinent to vacuum ultraviolet techniques to complete the demonstration of the diversity of methods available to the spectroscopist interested in the ultraviolet visible and infrared spectral regions. This book discusses the specific aspects of the technique of Fourier transform spectroscopy.Organized into five chapters, this volume begins with an overview of the large number of systematic effects in the recording of an interferogram. This text then examines the design approach for a Fourier transform spectrometer with focus on optics.

  9. Spectrometric techniques 3

    CERN Document Server

    Vanasse, George A

    2013-01-01

    Spectrometric Techniques, Volume III presents the applications of spectrometric techniques to atmospheric and space studies. This book reviews the spectral data processing and analysis techniques that are of broad applicability.Organized into five chapters, this volume begins with an overview of the instrumentation used for obtaining field data. This text then reviews the contribution that space-borne spectroscopy in the thermal IR has made to the understanding of the planets. Other chapters consider the instruments that have recorded the planetary emission spectra. This book discusses as well

  10. Quality Attribute Techniques Framework

    Science.gov (United States)

    Chiam, Yin Kia; Zhu, Liming; Staples, Mark

    The quality of software is achieved during its development. Development teams use various techniques to investigate, evaluate and control potential quality problems in their systems. These “Quality Attribute Techniques” target specific product qualities such as safety or security. This paper proposes a framework to capture important characteristics of these techniques. The framework is intended to support process tailoring, by facilitating the selection of techniques for inclusion into process models that target specific product qualities. We use risk management as a theory to accommodate techniques for many product qualities and lifecycle phases. Safety techniques have motivated the framework, and safety and performance techniques have been used to evaluate the framework. The evaluation demonstrates the ability of quality risk management to cover the development lifecycle and to accommodate two different product qualities. We identify advantages and limitations of the framework, and discuss future research on the framework.

  11. Detour technique, Dipping technique, or IIeal bladder flap technique for surgical correction of uretero-ileal anastomotic stricture in orthotopic ileal neobladder

    Directory of Open Access Journals (Sweden)

    Mohamed Wishahi

    2015-08-01

    Full Text Available ABSTRACTBackground:Uretero-ileal anastomotic stricture (UIAS is a urological complication after ileal neobladder, the initial management being endourological intervention. If this fails or stricture recurs, surgical intervention will be indicated.Design and Participants:From 1994 to 2013, 129 patients were treated for UIAS after unsuccessful endourological intervention. Unilateral UIAS was present in 101 patients, and bilateral in 28 patients; total procedures were 157. The previous ileal neobladder techniques were Hautmann neobladder, detubularized U shape, or spherical shape neobladder.Surgical procedures:Dipping technique was performed in 74 UIAS. Detour technique was done in 60 renal units. Ileal Bladder flap was indicated in 23 renal units. Each procedure ended with insertion of double J, abdominal drain, and indwelling catheter.Results:Follow-up was done for 12 to 36 months. Patency of the anastomosis was found in 91.7 % of cases. Thirteen patients (8.3% underwent antegrade dilatation and insertion of double J.Conclusion:After endourological treatment for uretero-ileal anastomotic failure, basically three techniques may be indicated: dipping technique, detour technique, and ileal bladder flap. The indications are dependent on the length of the stenotic/dilated ureteral segment. Better results for long length of stenotic ureter are obtained with detour technique; for short length stenotic ureter dipping technique; when the stenotic segment is 5 cm or more with a short ureter, the ileal tube flap is indicated. The use of double J stent is mandatory in the majority of cases. Early intervention is the rule for protecting renal units from progressive loss of function.

  12. Emerging optical nanoscopy techniques

    Directory of Open Access Journals (Sweden)

    Montgomery PC

    2015-09-01

    Full Text Available Paul C Montgomery, Audrey Leong-Hoi Laboratoire des Sciences de l'Ingénieur, de l'Informatique et de l'Imagerie (ICube, Unistra-CNRS, Strasbourg, France Abstract: To face the challenges of modern health care, new imaging techniques with subcellular resolution or detection over wide fields are required. Far field optical nanoscopy presents many new solutions, providing high resolution or detection at high speed. We present a new classification scheme to help appreciate the growing number of optical nanoscopy techniques. We underline an important distinction between superresolution techniques that provide improved resolving power and nanodetection techniques for characterizing unresolved nanostructures. Some of the emerging techniques within these two categories are highlighted with applications in biophysics and medicine. Recent techniques employing wider angle imaging by digital holography and scattering lens microscopy allow superresolution to be achieved for subcellular and even in vivo, imaging without labeling. Nanodetection techniques are divided into four subcategories using contrast, phase, deconvolution, and nanomarkers. Contrast enhancement is illustrated by means of a polarized light-based technique and with strobed phase-contrast microscopy to reveal nanostructures. Very high sensitivity phase measurement using interference microscopy is shown to provide nanometric surface roughness measurement or to reveal internal nanometric structures. Finally, the use of nanomarkers is illustrated with stochastic fluorescence microscopy for mapping intracellular structures. We also present some of the future perspectives of optical nanoscopy. Keywords: microscopy, imaging, superresolution, nanodetection, biophysics, medical imaging

  13. Techniques involving extreme environment, nondestructive techniques, computer methods in metals research, and data analysis

    International Nuclear Information System (INIS)

    Bunshah, R.F.

    1976-01-01

    A number of different techniques which range over several different aspects of materials research are covered in this volume. They are concerned with property evaluation of 4 0 K and below, surface characterization, coating techniques, techniques for the fabrication of composite materials, computer methods, data evaluation and analysis, statistical design of experiments and non-destructive test techniques. Topics covered in this part include internal friction measurements; nondestructive testing techniques; statistical design of experiments and regression analysis in metallurgical research; and measurement of surfaces of engineering materials

  14. Separation techniques: Chromatography

    Science.gov (United States)

    Coskun, Ozlem

    2016-01-01

    Chromatography is an important biophysical technique that enables the separation, identification, and purification of the components of a mixture for qualitative and quantitative analysis. Proteins can be purified based on characteristics such as size and shape, total charge, hydrophobic groups present on the surface, and binding capacity with the stationary phase. Four separation techniques based on molecular characteristics and interaction type use mechanisms of ion exchange, surface adsorption, partition, and size exclusion. Other chromatography techniques are based on the stationary bed, including column, thin layer, and paper chromatography. Column chromatography is one of the most common methods of protein purification. PMID:28058406

  15. New techniques in quality assurance

    International Nuclear Information System (INIS)

    Fornicola, J.C.

    1987-01-01

    GPU Nuclear Corp. has a multifaceted quality assurance (QA) program. This program includes a comprehensive QA organization to help ensure its implementation. The QA organization employs various techniques in assuring quality at GPU Nuclear. These techniques not only include the typical QA/quality-control verification activities, i.e., QA engineering, quality control, and audits, but also include some new innovative techniques. Several new techniques have been developed for verifying activities. These techniques include monitoring and functional audits of safety systems. Several new techniques for assessing performance and adequacy and effectiveness of plant and QA programs, such as plant assessments and QA systems engineering evaluations, have also been developed. This paper provides an overview of these and other new techniques being employed by GPU Nuclear's QA organization

  16. Microalgae harvesting techniques: A review.

    Science.gov (United States)

    Singh, Gulab; Patidar, S K

    2018-07-01

    Microalgae with wide range of commercial applications have attracted a lot of attention of the researchers in the last few decades. However, microalgae utilization is not economically sustainable due to high cost of harvesting. A wide range of solid - liquid separation techniques are available for microalgae harvesting. The techniques include coagulation and flocculation, flotation, centrifugation and filtration or a combination of various techniques. Despite the importance of harvesting to the economics and energy balance, there is no universal harvesting technique for microalgae. Therefore, this review focuses on assessing technical, economical and application potential of various harvesting techniques so as to allow selection of an appropriate technology for cost effectively harvesting of microalgae from their culture medium. Various harvesting and concentrating techniques of microalgae were reviewed to suggest order of suitability of the techniques for four main microalgae applications i.e biofuel, human and animal food, high valued products, and water quality restoration. For deciding the order of suitability, a comparative analysis of various harvesting techniques based on the six common criterions (i.e biomass quality, cost, biomass quantity, processing time, species specific and toxicity) has been done. Based on the order of various techniques vis-a-vis various criteria and preferred order of criteria for various applications, order of suitability of harvesting techniques for various applications has been decided. Among various harvesting techniques, coagulation and flocculation, centrifugation and filtration were found to be most suitable for considered applications. These techniques may be used alone or in combination for increasing the harvesting efficiency. Copyright © 2018 Elsevier Ltd. All rights reserved.

  17. Method for automatically evaluating a transition from a batch manufacturing technique to a lean manufacturing technique

    Science.gov (United States)

    Ivezic, Nenad; Potok, Thomas E.

    2003-09-30

    A method for automatically evaluating a manufacturing technique comprises the steps of: receiving from a user manufacturing process step parameters characterizing a manufacturing process; accepting from the user a selection for an analysis of a particular lean manufacturing technique; automatically compiling process step data for each process step in the manufacturing process; automatically calculating process metrics from a summation of the compiled process step data for each process step; and, presenting the automatically calculated process metrics to the user. A method for evaluating a transition from a batch manufacturing technique to a lean manufacturing technique can comprise the steps of: collecting manufacturing process step characterization parameters; selecting a lean manufacturing technique for analysis; communicating the selected lean manufacturing technique and the manufacturing process step characterization parameters to an automatic manufacturing technique evaluation engine having a mathematical model for generating manufacturing technique evaluation data; and, using the lean manufacturing technique evaluation data to determine whether to transition from an existing manufacturing technique to the selected lean manufacturing technique.

  18. Vitamin D Supplementation in Submariners

    Science.gov (United States)

    2008-12-02

    including diabetes mellitus type 1, rheumatoid arthritis , experimental autoimmune encephalomyelitis, inflammatory bowel disease, and systemic lupus...the safety and effectiveness of monthly ergocalciferol in hemodialysis patients . Nephron Clin Pract 2007;105(3):132-8 91. Goldzieher JW, Zerwekh...D in patients with persistent, nonspecific musculoskeletal pain. Mayo Clin Proc 2003;78:1463-1470. 31. Glerup H, Mikkelsen K, Poulsen L, et al

  19. [Diuretics].

    Science.gov (United States)

    Filipowicz, Ewa; Staszków, Monika

    2013-01-01

    Diuretics are an important class of medicine used to treat a wide variety of acute and chronic conditions, like: heart failure, hypertension and renal diseases. They act by increasing urinary excretion of water, sodium, and some others electrolytes, at different sites in the nephron. In this paper the mechanisms of action, use, dosing and adverse effects of the commonly used diuretics are reviewed.

  20. Non-contact ultrasound techniques

    International Nuclear Information System (INIS)

    Khazali Mohd Zin

    2001-01-01

    Non-contact ultrasound plays significant role in material characterisation and inspection. Unlike conventional ultrasonic techniques, non-contact ultrasonic is mostly applicable to areas where the former has its weaknesses and limitations. It is interesting to note that the non-contact ultrasonic technique has an important significant application in industry. The technique is signified by the fact that the object to be inspected is further away from the ultrasonic source, no couplant is needed and inconsistent pressure between the transducer and the specimen can be eliminated. The paper discusses some of the non-contact ultrasound technique and its applications. (Author)

  1. Principles of fluorescence techniques

    CERN Document Server

    2016-01-01

    Fluorescence techniques are being used and applied increasingly in academics and industry. The Principles of Fluorescence Techniques course will outline the basic concepts of fluorescence techniques and the successful utilization of the currently available commercial instrumentation. The course is designed for students who utilize fluorescence techniques and instrumentation and for researchers and industrial scientists who wish to deepen their knowledge of fluorescence applications. Key scientists in the field will deliver theoretical lectures. The lectures will be complemented by the direct utilization of steady-state and lifetime fluorescence instrumentation and confocal microscopy for FLIM and FRET applications provided by leading companies.

  2. Disagreements around techniques

    International Nuclear Information System (INIS)

    Sachsse, H.

    The modern man lives in disagreement with its techniques. Technical progress is the foundation of its material and spiritual existence, but he does not like it. Specialization, difficult understanding of the technical procedures and the price that has to be paid for technical progress, have led to a deep-going enstrangement. Therefore the question: What kind of human function has our technique. It is understood as an extension and perfection of our bodily organs, in order to increase our ability to see and to hear enormously, and to intervene formatively in the existing reality. Technique is therefore an instrument of comprehensive self-realization of man. (orig./GL) [de

  3. Advanced analytical techniques

    International Nuclear Information System (INIS)

    Mrochek, J.E.; Shumate, S.E.; Genung, R.K.; Bahner, C.T.; Lee, N.E.; Dinsmore, S.R.

    1976-01-01

    The development of several new analytical techniques for use in clinical diagnosis and biomedical research is reported. These include: high-resolution liquid chromatographic systems for the early detection of pathological molecular constituents in physiologic body fluids; gradient elution chromatography for the analysis of protein-bound carbohydrates in blood serum samples, with emphasis on changes in sera from breast cancer patients; electrophoretic separation techniques coupled with staining of specific proteins in cellular isoenzymes for the monitoring of genetic mutations and abnormal molecular constituents in blood samples; and the development of a centrifugal elution chromatographic technique for the assay of specific proteins and immunoglobulins in human blood serum samples

  4. Changes in urological surgical techniques

    Directory of Open Access Journals (Sweden)

    Oktay Üçer

    2010-06-01

    Full Text Available Recently, laparoscopic and afterwards robotic techniques have constituted most of urologic surgery procedures. Open surgery may give place to robotic surgery due to possible widespread use of robots in the future. Studies, that compare these two techniques are usually designed about radical prostatectomy, since it is the most common operation performed by using these techniques. In literature,robotic surgery seems more advantageous than other techniques but the most important disadvantage of this technique is cost-effective problems. In present review,history of open, laparoscopic and robotic surgery, and comparison of advantages, disadvantages and cost of these techniques have been discussed with literature.

  5. Amniotic Membrane Transplant with a Special Technique (Motowa's Sandwich Technique) in Mooren's Ulcer.

    Science.gov (United States)

    Al Motowa, Saeed; Al Zobidi, Mohammed

    2015-01-01

    To illustrate amniotic membrane transplant (AMT) with a novel surgical technique ("sandwich technique") for treating patients with malignant Mooren's ulcer. A case report of a patient with bilateral, malignant Mooren's ulcer who had undergone systemic steroid therapy and topical immunosuppresive therapy to stabilize his condition. However, perforation of cornea occurred in one eye. AMT with a new surgical technique ("Motowa's sandwich technique") was performed to treat this case. On the 1(st) day postoperatively, there was no pain, no photophobia, and visual acuity was same as preoperatively. At 4 weeks postoperatively, visual acuity improved in the right eye to 20/160 with pinhole, and there was no fluorescein staining. The right eye was quiet. Amniotic membrane transplant with "Motowa's sandwich technique" resulted in the preservation of the anatomical integrity and progression of disease was halted along with an improved vision. This technique is a novel surgical modality in treating Mooren's ulcer. Further study on a large cohort of patients is required for evidence-based data to verify the outcome of this initial case report.

  6. Enseignement technique/Technical Training

    CERN Multimedia

    1998-01-01

    Bureautique et techniques administratives/Office Automation & Administrative Techniques - Premiers pas/Getting started - E-Mail - Management Tools - WWW - Applications bureautiques/Office applications

  7. Tracer techniques in microelectronics

    International Nuclear Information System (INIS)

    Flachowsky, J.; Freyer, K.

    1981-01-01

    Tracer technique and neutron activation analysis are capable of measuring impurities in semiconductor material or on the semiconductor surface in a very low concentration range. The methods, combined with autoradiography, are also suitable to determine dopant distributions in silicon. However, both techniques suffer from certain inherent experimental difficulties and/or limitations which are discussed. Methods of tracer technique practicable in the semiconductor field are described. (author)

  8. Regenerative medicine in kidney disease: where we stand and where to go.

    Science.gov (United States)

    Borges, Fernanda T; Schor, Nestor

    2017-07-22

    The kidney is a complex organ with more than 20 types of specialized cells that play an important role in maintaining the body's homeostasis. The epithelial tubular cell is formed during embryonic development and has little proliferative capacity under physiological conditions, but after acute injury the kidney does have regenerative capacity. However, after repetitive or severe lesions, it may undergo a maladaptation process that predisposes it to chronic kidney injury. Regenerative medicine includes various repair and regeneration techniques, and these have gained increasing attention in the scientific literature. In the future, not only will these techniques contribute to the repair and regeneration of the human kidney, but probably also to the construction of an entire organ. New mechanisms studied for kidney regeneration and repair include circulating stem cells as mesenchymal stromal/stem cells and their paracrine mechanisms of action; renal progenitor stem cells; the leading role of tubular epithelial cells in the tubular repair process; the study of zebrafish larvae to understand the process of nephron development, kidney scaffold and its repopulation; and, finally, the development of organoids. This review elucidates where we are in terms of current scientific knowledge regarding these mechanisms and the promises of future scientific perspectives.

  9. Contamination Control Techniques

    Energy Technology Data Exchange (ETDEWEB)

    EBY, J.L.

    2000-05-16

    Welcome to a workshop on contamination Control techniques. This work shop is designed for about two hours. Attendee participation is encouraged during the workshop. We will address different topics within contamination control techniques; present processes, products and equipment used here at Hanford and then open the floor to you, the attendees for your input on the topics.

  10. Contamination Control Techniques

    International Nuclear Information System (INIS)

    EBY, J.L.

    2000-01-01

    Welcome to a workshop on contamination Control techniques. This work shop is designed for about two hours. Attendee participation is encouraged during the workshop. We will address different topics within contamination control techniques; present processes, products and equipment used here at Hanford and then open the floor to you, the attendees for your input on the topics

  11. Next generation initiation techniques

    Science.gov (United States)

    Warner, Tom; Derber, John; Zupanski, Milija; Cohn, Steve; Verlinde, Hans

    1993-01-01

    Four-dimensional data assimilation strategies can generally be classified as either current or next generation, depending upon whether they are used operationally or not. Current-generation data-assimilation techniques are those that are presently used routinely in operational-forecasting or research applications. They can be classified into the following categories: intermittent assimilation, Newtonian relaxation, and physical initialization. It should be noted that these techniques are the subject of continued research, and their improvement will parallel the development of next generation techniques described by the other speakers. Next generation assimilation techniques are those that are under development but are not yet used operationally. Most of these procedures are derived from control theory or variational methods and primarily represent continuous assimilation approaches, in which the data and model dynamics are 'fitted' to each other in an optimal way. Another 'next generation' category is the initialization of convective-scale models. Intermittent assimilation systems use an objective analysis to combine all observations within a time window that is centered on the analysis time. Continuous first-generation assimilation systems are usually based on the Newtonian-relaxation or 'nudging' techniques. Physical initialization procedures generally involve the use of standard or nonstandard data to force some physical process in the model during an assimilation period. Under the topic of next-generation assimilation techniques, variational approaches are currently being actively developed. Variational approaches seek to minimize a cost or penalty function which measures a model's fit to observations, background fields and other imposed constraints. Alternatively, the Kalman filter technique, which is also under investigation as a data assimilation procedure for numerical weather prediction, can yield acceptable initial conditions for mesoscale models. The

  12. Mimicking the Kidney: A Key Role in Organ-on-Chip Development

    Directory of Open Access Journals (Sweden)

    Roberto Paoli

    2016-07-01

    Full Text Available Pharmaceutical drug screening and research into diseases call for significant improvement in the effectiveness of current in vitro models. Better models would reduce the likelihood of costly failures at later drug development stages, while limiting or possibly even avoiding the use of animal models. In this regard, promising advances have recently been made by the so-called “organ-on-chip” (OOC technology. By combining cell culture with microfluidics, biomedical researchers have started to develop microengineered models of the functional units of human organs. With the capacity to mimic physiological microenvironments and vascular perfusion, OOC devices allow the reproduction of tissue- and organ-level functions. When considering drug testing, nephrotoxicity is a major cause of attrition during pre-clinical, clinical, and post-approval stages. Renal toxicity accounts for 19% of total dropouts during phase III drug evaluation—more than half the drugs abandoned because of safety concerns. Mimicking the functional unit of the kidney, namely the nephron, is therefore a crucial objective. Here we provide an extensive review of the studies focused on the development of a nephron-on-chip device.

  13. Self-organisation after embryonic kidney dissociation is driven via selective adhesion of ureteric epithelial cells.

    Science.gov (United States)

    Lefevre, James G; Chiu, Han S; Combes, Alexander N; Vanslambrouck, Jessica M; Ju, Ali; Hamilton, Nicholas A; Little, Melissa H

    2017-03-15

    Human pluripotent stem cells, after directed differentiation in vitro , can spontaneously generate complex tissues via self-organisation of the component cells. Self-organisation can also reform embryonic organ structure after tissue disruption. It has previously been demonstrated that dissociated embryonic kidneys can recreate component epithelial and mesenchymal relationships sufficient to allow continued kidney morphogenesis. Here, we investigate the timing and underlying mechanisms driving self-organisation after dissociation of the embryonic kidney using time-lapse imaging, high-resolution confocal analyses and mathematical modelling. Organotypic self-organisation sufficient for nephron initiation was observed within a 24 h period. This involved cell movement, with structure emerging after the clustering of ureteric epithelial cells, a process consistent with models of random cell movement with preferential cell adhesion. Ureteric epithelialisation rapidly followed the formation of ureteric cell clusters with the reformation of nephron-forming niches representing a later event. Disruption of P-cadherin interactions was seen to impair this ureteric epithelial cell clustering without affecting epithelial maturation. This understanding could facilitate improved regulation of patterning within organoids and facilitate kidney engineering approaches guided by cell-cell self-organisation. © 2017. Published by The Company of Biologists Ltd.

  14. Advances in the staging of renal cell carcinoma with high-resolution imaging

    International Nuclear Information System (INIS)

    Hallscheidt, P.; Noeldge, G.; Schawo, S.; Kauffmann, G.; Palmowski, M.; Bartling, S.; Pfitzenmaier, J.

    2007-01-01

    Modern imaging modalities such as computed tomography (CT) and magnetic resonance imaging (MRI) allow high-resolution imaging of the abdomen. Modern scanners made high temporal as well as high spatial resolution available. Therapeutic approaches to the treatment of renal cell carcinoma have been improved over the recent years. Besides conventional and open laparoscopic tumor nephrectomy and nephron sparing, surgical approaches such as local tumor cryotherapy and radiofrequency ablation (RF) are ablative modalities and are used increasingly. Improved anesthesiological methods and new surgical approaches also allow curative treatment in extended tumors. Prerequisites for preoperative imaging modalities include visualization of the kidney tumor as well as its staging. Tumor-related infiltration of the renal pelvis or invasion of the perinephric fat and the renal hilus has to be excluded prior to nephron sparing surgery. In cases with extended tumors with infiltration of the inferior vena cava, it is necessary to visualize the exact extension of the tumor growth towards the right atrium in the vena cava. The radiologist should be informed about the diagnostic possibilities and limitations of the imaging modalities of CT and MRI in order to support the urologist in the planning and performance of surgical therapeutical approaches. (orig.)

  15. Advances in the staging of renal cell carcinoma with high-resolution imaging; Fortschritte im Staging des Nierenzellkarzinoms mittels hochaufloesender Bildgebung

    Energy Technology Data Exchange (ETDEWEB)

    Hallscheidt, P.; Noeldge, G.; Schawo, S.; Kauffmann, G.; Palmowski, M. [Abt. Radiodiagnostik, Radiologische Klinik, Univ. Heidelberg (Germany); Bartling, S. [Medizinische Physik, DKFZ Heidelberg (Germany); Pfitzenmaier, J. [Urologische Klinik, Univ. Heidelberg (Germany)

    2007-12-15

    Modern imaging modalities such as computed tomography (CT) and magnetic resonance imaging (MRI) allow high-resolution imaging of the abdomen. Modern scanners made high temporal as well as high spatial resolution available. Therapeutic approaches to the treatment of renal cell carcinoma have been improved over the recent years. Besides conventional and open laparoscopic tumor nephrectomy and nephron sparing, surgical approaches such as local tumor cryotherapy and radiofrequency ablation (RF) are ablative modalities and are used increasingly. Improved anesthesiological methods and new surgical approaches also allow curative treatment in extended tumors. Prerequisites for preoperative imaging modalities include visualization of the kidney tumor as well as its staging. Tumor-related infiltration of the renal pelvis or invasion of the perinephric fat and the renal hilus has to be excluded prior to nephron sparing surgery. In cases with extended tumors with infiltration of the inferior vena cava, it is necessary to visualize the exact extension of the tumor growth towards the right atrium in the vena cava. The radiologist should be informed about the diagnostic possibilities and limitations of the imaging modalities of CT and MRI in order to support the urologist in the planning and performance of surgical therapeutical approaches. (orig.)

  16. Notch activates Wnt-4 signalling to control medio-lateral patterning of the pronephros.

    Science.gov (United States)

    Naylor, Richard W; Jones, Elizabeth A

    2009-11-01

    Previous studies have highlighted a role for the Notch signalling pathway during pronephrogenesis in the amphibian Xenopus laevis, and in nephron development in the mammalian metanephros, yet a mechanism for this function remains elusive. Here, we further the understanding of how Notch signalling patterns the early X. laevis pronephros anlagen, a function that might be conserved in mammalian nephron segmentation. Our results indicate that early phase pronephric Notch signalling patterns the medio-lateral axis of the dorso-anterior pronephros anlagen, permitting the glomus and tubules to develop in isolation. We show that this novel function acts through the Notch effector gene hrt1 by upregulating expression of wnt4. Wnt-4 then patterns the proximal pronephric anlagen to establish the specific compartments that span the medio-lateral axis. We also identified pronephric expression of lunatic fringe and radical fringe that is temporally and spatially appropriate for a role in regulating Notch signalling in the dorso-anterior region of the pronephros anlagen. On the basis of these results, along with data from previous publications, we propose a mechanism by which the Notch signalling pathway regulates a Wnt-4 function that patterns the proximal pronephric anlagen.

  17. Metabolism and sites of effects of uranium after incorporation along different routes in mice, rabbits and piglets

    Energy Technology Data Exchange (ETDEWEB)

    Walinder, G. (Swedish Univ. of Agricultural Sciences, Uppsala (Sweden))

    1989-01-01

    The present experiments comprise i.p. injections of uranyl nitrate and sodium uranyl tricarbonate (mice, piglets), inhalation of U/sub 3/O/sub 8/ aerosols (mice), and absorption of U/sub 3/O/sub 8/ and uranyl acetate from cutaneous and subcutaneous pockets in the skin of rabbits and pigs. The following results were remarkably consistent in the three species. (1) The kidney is the critical organ only after massive incorporation of uranium. At lower amounts of absorbed U and/or at lower incorporation rates from U depots in lungs or in the skin, the highest uptake and retention was found in the spleen and on the bone surfaces. (2) Intravenous injections of 30 {mu}g U or more, cause a pronounced ischaemia in the renal cortex. The highest initial deposition of uranium was found in the juxtamedullary zone of the cortex where the earliest and most severe lesions were found. (3) The connective tissue barrier and particularly the hyaluronic acid in the loose connective tissue does play an important role for the permeability of the skin. A hyaluronidase inhibitor (polyphloretinphosphate) was shown substantially to reduce the absorption of U from skin depots. (author).

  18. Metabolism and sites of effects of uranium after incorporation along different routes in mice, rabbits and piglets

    International Nuclear Information System (INIS)

    Walinder, G.

    1989-01-01

    The present experiments comprise i.p. injections of uranyl nitrate and sodium uranyl tricarbonate (mice, piglets), inhalation of U 3 O 8 aerosols (mice), and absorption of U 3 O 8 and uranyl acetate from cutaneous and subcutaneous pockets in the skin of rabbits and pigs. The following results were remarkably consistent in the three species. (1) The kidney is the critical organ only after massive incorporation of uranium. At lower amounts of absorbed U and/or at lower incorporation rates from U depots in lungs or in the skin, the highest uptake and retention was found in the spleen and on the bone surfaces. (2) Intravenous injections of 30 μg U or more, cause a pronounced ischaemia in the renal cortex. The highest initial deposition of uranium was found in the juxtamedullary zone of the cortex where the earliest and most severe lesions were found. (3) The connective tissue barrier and particularly the hyaluronic acid in the loose connective tissue does play an important role for the permeability of the skin. A hyaluronidase inhibitor (polyphloretinphosphate) was shown substantially to reduce the absorption of U from skin depots. (author)

  19. The Soluble Epoxide Hydrolase Inhibitor AR9281 Decreases Blood Pressure, Ameliorates Renal Injury and Improves Vascular Function in Hypertension

    Directory of Open Access Journals (Sweden)

    Sean Shaw

    2009-12-01

    Full Text Available Soluble epoxide hydrolase inhibitors (sEHIs are demonstrating promise as potential pharmaceutical agents for the treatment of cardiovascular disease, diabetes, inflammation, and kidney disease. The present study determined the ability of a first-inclass sEHI, AR9281, to decrease blood pressure, improve vascular function, and decrease renal inflammation and injury in angiotensin hypertension. Rats were infused with angiotensin and AR9281 was given orally during the 14-day infusion period. Systolic blood pressure averaged 180 ± 5 mmHg in vehicle treated and AR9281 treatment significantly lowered blood pressure to 142 ± 7 mmHg in angiotensin hypertension. Histological analysis demonstrated decreased injury to the juxtamedullary glomeruli. Renal expression of inflammatory genes was increased in angiotensin hypertension and two weeks of AR9281 treatment decreased this index of renal inflammation. Vascular function in angiotensin hypertension was also improved by AR9281 treatment. Decreased afferent arteriolar and mesenteric resistance endothelial dependent dilator responses were ameliorated by AR9281 treatment of angiotensin hypertensive rats. These data demonstrate that the first-in-class sEHI, AR9281, lowers blood pressure, improves vascular function and reduces renal damage in angiotensin hypertension.

  20. Percutaneous thermal ablation of renal neoplasms

    International Nuclear Information System (INIS)

    Tacke, J.; Mahnken, A.H.; Guenther, R.W.

    2005-01-01

    Due to modern examination techniques such as multidetector computed tomography and high-field magnetic resonance imaging, the detection rate of renal neoplasms is continually increasing. Even though tumors exceeding 4 cm in diameter rarely metastasize, all renal lesions that are possible neoplasms should be treated. Traditional treatment techniques include radical nephrectomy or nephron-sparing resection, which are increasingly performed laparoscopically. Modern thermal ablation techniques such as hyperthermal techniques like radiofrequency ablation RFA, laser induced thermal ablation LITT, focused ultrasound FUS and microwave therapy MW, as well as hypothermal techniques (cryotherapy) may be a useful treatment option for patients who are unfit for or refuse surgical resection. Cryotherapy is the oldest and best known thermal ablation technique and can be performed laparoscopically or percutaneously. Since subzero temperatures have no antistyptic effect, additional maneuvers must be performed to control bleeding. Percutaneous cryotherapy of renal tumors is a new and interesting method, but experience with it is still limited. Radiofrequency ablation is the most frequently used method. Modern probe design allows volumes between 2 and 5 cm in diameter to be ablated. Due to hyperthermal tract ablation, the procedure is deemed to be safe and has a low complication rate. Although there are no randomized comparative studies to open resection, the preliminary results for renal RFA are promising and show RFA to be superior to other thermal ablation techniques. Clinical success rates are over 90% for both, cryo- and radiofrequency ablation. Whereas laser induced thermal therapy is established in hepatic ablation, experience is minimal with respect to renal application. For lesions of more than 2 cm in diameter, additional cooling catheters are required. MR thermometry offers temperature control during ablation. Microwave ablation is characterized by small ablation volumes

  1. Percutaneous thermal ablation of renal neoplasms; Perkutane Thermoablation von Nierentumoren

    Energy Technology Data Exchange (ETDEWEB)

    Tacke, J. [Inst. fuer Diagnostische und Interventionelle Radiologie/Neuroradiologie, Klinikum Passau (Germany); Mahnken, A.H.; Guenther, R.W. [Klinik fuer Radiologische Diagnostik, Universitaetsklinikum Aachen (Germany)

    2005-12-15

    Due to modern examination techniques such as multidetector computed tomography and high-field magnetic resonance imaging, the detection rate of renal neoplasms is continually increasing. Even though tumors exceeding 4 cm in diameter rarely metastasize, all renal lesions that are possible neoplasms should be treated. Traditional treatment techniques include radical nephrectomy or nephron-sparing resection, which are increasingly performed laparoscopically. Modern thermal ablation techniques such as hyperthermal techniques like radiofrequency ablation RFA, laser induced thermal ablation LITT, focused ultrasound FUS and microwave therapy MW, as well as hypothermal techniques (cryotherapy) may be a useful treatment option for patients who are unfit for or refuse surgical resection. Cryotherapy is the oldest and best known thermal ablation technique and can be performed laparoscopically or percutaneously. Since subzero temperatures have no antistyptic effect, additional maneuvers must be performed to control bleeding. Percutaneous cryotherapy of renal tumors is a new and interesting method, but experience with it is still limited. Radiofrequency ablation is the most frequently used method. Modern probe design allows volumes between 2 and 5 cm in diameter to be ablated. Due to hyperthermal tract ablation, the procedure is deemed to be safe and has a low complication rate. Although there are no randomized comparative studies to open resection, the preliminary results for renal RFA are promising and show RFA to be superior to other thermal ablation techniques. Clinical success rates are over 90% for both, cryo- and radiofrequency ablation. Whereas laser induced thermal therapy is established in hepatic ablation, experience is minimal with respect to renal application. For lesions of more than 2 cm in diameter, additional cooling catheters are required. MR thermometry offers temperature control during ablation. Microwave ablation is characterized by small ablation volumes

  2. Managerial Techniques in Educational Administration.

    Science.gov (United States)

    Lane, John J.

    1983-01-01

    Management techniques developed during the past 20 years assume the rational bureaucratic model. School administration requires contingent techniques. Quality Circle, Theory Z, and the McKenzie 7-Framework are discussed as techniques to increase school productivity. (MD)

  3. Addendum: First injection technique recommendations for patients with diabetes, Forum for Injection Techniques India

    Directory of Open Access Journals (Sweden)

    Sanjay Kalra

    2013-01-01

    Full Text Available The forum for injection techniques, India recommendation, the first ever in the country on insulin injcetion techniques, have covered the science and the art of insulin injection technique in an exhaustive manner. However, a few gaps were identified in the document, which are addressed in the current addendum. This article focuses on insulin injection technique in special clinical situations, including geriatric people, women in pregnancy and those with dermatological or surgical disease who live with diabetes. The addendum also covers salient features of administration of insulin using the insulin pump.

  4. Parachute technique for partial penectomy

    Directory of Open Access Journals (Sweden)

    Fernando Korkes

    2010-04-01

    Full Text Available PURPOSE: Penile carcinoma is a rare but mutilating malignancy. In this context, partial penectomy is the most commonly applied approach for best oncological results. We herein propose a simple modification of the classic technique of partial penectomy, for better cosmetic and functional results. TECHNIQUE: If partial penectomy is indicated, the present technique can bring additional benefits. Different from classical technique, the urethra is spatulated only ventrally. An inverted "V" skin flap with 0.5 cm of extension is sectioned ventrally. The suture is performed with vicryl 4-0 in a "parachute" fashion, beginning from the ventral portion of the urethra and the "V" flap, followed by the "V" flap angles and than by the dorsal portion of the penis. After completion of the suture, a Foley catheter and light dressing are placed for 24 hours. CONCLUSIONS: Several complex reconstructive techniques have been previously proposed, but normally require specific surgical abilities, adequate patient selection and staged procedures. We believe that these reconstructive techniques are very useful in some specific subsets of patients. However, the technique herein proposed is a simple alternative that can be applied to all men after a partial penectomy, and takes the same amount of time as that in the classic technique. In conclusion, the "parachute" technique for penile reconstruction after partial amputation not only improves the appearance of the penis, but also maintains an adequate function.

  5. Handbook of laboratory techniques

    International Nuclear Information System (INIS)

    2002-01-01

    The Nuclear Regulatory Authority in Argentina have laboratories of support to regulations functions on radiological and nuclear safety, safeguards and physical protection, that have a surface of 2950 m 2 in the Ezeiza Atomic Center. The manual describes in seven chapters the different techniques developed and applied in the laboratories along four decades of existence. The chapter 1: Dedicated to the treatment of environmental samples, described the procedures associated with the different types of samples: deposits, waters, sediments, vegetables, milk, fish and diet. The chapter 2: Details 48 radiochemical techniques associated to the measurements of americium 241, carbon 16, strontium 90, iodine 129, plutonium, radium 226, radon, uranium, nickel and actinides. The chapter 3: Describes the measurements techniques of alpha and gamma spectrometry. The different techniques of biological and physical dosimetry are described in the chapters 5 and 6 respectively. The final chapter is dedicated the techniques of external and internal contamination. It s important to emphasize that this manual contains the standardized technologies that the Nuclear Regulatory Authority of Argentina submits regularly to international comparisons

  6. Ultrasonic techniques for fluids characterization

    CERN Document Server

    Povey, Malcolm J W

    1997-01-01

    This book is a comprehensive and practical guide to the use of ultrasonic techniques for the characterization of fluids. Focusing on ultrasonic velocimetry, the author covers the basic topics and techniques necessaryfor successful ultrasound measurements on emulsions, dispersions, multiphase media, and viscoelastic/viscoplastic materials. Advanced techniques such as scattering, particle sizing, and automation are also presented. As a handbook for industrial and scientific use, Ultrasonic Techniques for Fluids Characterization is an indispensable guide to chemists and chemical engineers using ultrasound for research or process monitoring in the chemical, food processing, pharmaceutical, cosmetic, biotechnology,and fuels industries. Key Features * Appeals to anyone using ultrasound to study fluids * Provides the first detailed description of the ultrasound profiling technique for dispersions * Describes new techniques for measuring phase transitions and nucleation, such as water/ice and oil/fat * Presents the l...

  7. Expression of stem cell markers in the human fetal kidney.

    Directory of Open Access Journals (Sweden)

    Sally Metsuyanim

    Full Text Available In the human fetal kidney (HFK self-renewing stem cells residing in the metanephric mesenchyme (MM/blastema are induced to form all cell types of the nephron till 34(th week of gestation. Definition of useful markers is crucial for the identification of HFK stem cells. Because wilms' tumor, a pediatric renal cancer, initiates from retention of renal stem cells, we hypothesized that surface antigens previously up-regulated in microarrays of both HFK and blastema-enriched stem-like wilms' tumor xenografts (NCAM, ACVRIIB, DLK1/PREF, GPR39, FZD7, FZD2, NTRK2 are likely to be relevant markers. Comprehensive profiling of these putative and of additional stem cell markers (CD34, CD133, c-Kit, CD90, CD105, CD24 in mid-gestation HFK was performed using immunostaining and FACS in conjunction with EpCAM, an epithelial surface marker that is absent from the MM and increases along nephron differentiation and hence can be separated into negative, dim or bright fractions. No marker was specifically localized to the MM. Nevertheless, FZD7 and NTRK2 were preferentially localized to the MM and emerging tubules (50% of HFK cells and predominantly co-express EpCAM(bright, indicating they are mostly markers of differentiation. Furthermore, localization of NCAM exclusively in the MM and in its nephron progenitor derivatives but also in stroma and the expression pattern of significantly elevated renal stem/progenitor genes Six2, Wt1, Cited1, and Sall1 in NCAM(+EpCAM(- and to a lesser extent in NCAM(+EpCAM(+ fractions confirmed regional identity of cells and assisted us in pinpointing the presence of subpopulations that are putative MM-derived progenitor cells (NCAM(+EpCAM(+FZD7(+, MM stem cells (NCAM(+EpCAM(-FZD7(+ or both (NCAM(+FZD7(+. These results and concepts provide a framework for developing cell selection strategies for human renal cell-based therapies.

  8. Nuclear techniques in industry

    International Nuclear Information System (INIS)

    Hammad, F.H.

    1994-01-01

    Nuclear techniques are utilized in almost every industry. The discussion in this paper includes discussions on tracer methods and uses nucleonic control systems technology; non-destructive testing techniques and radiation technology. 1 fig., 2 tabs

  9. Airway Clearance Techniques (ACTs)

    Medline Plus

    Full Text Available ... many challenges, including medical, social, and financial. By learning more about how you can manage your disease every day, you can ultimately help find a ... Cycle of Breathing Technique Airway Clearance Techniques Autogenic ...

  10. Approximation techniques for engineers

    CERN Document Server

    Komzsik, Louis

    2006-01-01

    Presenting numerous examples, algorithms, and industrial applications, Approximation Techniques for Engineers is your complete guide to the major techniques used in modern engineering practice. Whether you need approximations for discrete data of continuous functions, or you''re looking for approximate solutions to engineering problems, everything you need is nestled between the covers of this book. Now you can benefit from Louis Komzsik''s years of industrial experience to gain a working knowledge of a vast array of approximation techniques through this complete and self-contained resource.

  11. Airway Clearance Techniques (ACTs)

    Medline Plus

    Full Text Available ... decisions about your health care. CF Genetics: The Basics CF Mutations Video Series Find Out More About ... of Breathing Technique Airway Clearance Techniques Autogenic Drainage Basics of Lung Care Chest Physical Therapy Coughing and ...

  12. Airway Clearance Techniques (ACTs)

    Medline Plus

    Full Text Available ... Active Cycle of Breathing Technique Airway Clearance Techniques Autogenic Drainage Basics of Lung Care Chest Physical Therapy ... clearance. Facebook Twitter Email More Related Content Medications Autogenic Drainage Positive Expiratory Pressure High-Frequency Chest Wall ...

  13. Airway Clearance Techniques (ACTs)

    Medline Plus

    Full Text Available ... a range of treatment options. Airway Clearance Active Cycle of Breathing Technique Airway Clearance Techniques Autogenic Drainage ... LEGACY GIFT Sponsor a Participant CF Climb CF Cycle for Life Great Strides Xtreme Hike Participate In ...

  14. Airway Clearance Techniques (ACTs)

    Medline Plus

    Full Text Available ... Cycle of Breathing Technique Airway Clearance Techniques Autogenic Drainage Basics of Lung Care Chest Physical Therapy Coughing ... Facebook Twitter Email More Related Content Medications Autogenic Drainage Positive Expiratory Pressure High-Frequency Chest Wall Oscillation ( ...

  15. Sterility test by radiometric technique

    International Nuclear Information System (INIS)

    Faruq, Muhammad

    1980-01-01

    Sterility test of pharmaceuticals can be carried out by the application of pharmacopoeia and radiometric technique. In Indonesia the application of pharmacopoeia technique is carried out through liquid germination for aerobacteria and for fungus and yeast. Radiometric technique is applied to autotrop and heterotrop bacteria. (SMN)

  16. Review of advanced imaging techniques

    Directory of Open Access Journals (Sweden)

    Yu Chen

    2012-01-01

    Full Text Available Pathology informatics encompasses digital imaging and related applications. Several specialized microscopy techniques have emerged which permit the acquisition of digital images ("optical biopsies" at high resolution. Coupled with fiber-optic and micro-optic components, some of these imaging techniques (e.g., optical coherence tomography are now integrated with a wide range of imaging devices such as endoscopes, laparoscopes, catheters, and needles that enable imaging inside the body. These advanced imaging modalities have exciting diagnostic potential and introduce new opportunities in pathology. Therefore, it is important that pathology informaticists understand these advanced imaging techniques and the impact they have on pathology. This paper reviews several recently developed microscopic techniques, including diffraction-limited methods (e.g., confocal microscopy, 2-photon microscopy, 4Pi microscopy, and spatially modulated illumination microscopy and subdiffraction techniques (e.g., photoactivated localization microscopy, stochastic optical reconstruction microscopy, and stimulated emission depletion microscopy. This article serves as a primer for pathology informaticists, highlighting the fundamentals and applications of advanced optical imaging techniques.

  17. DCT-based cyber defense techniques

    Science.gov (United States)

    Amsalem, Yaron; Puzanov, Anton; Bedinerman, Anton; Kutcher, Maxim; Hadar, Ofer

    2015-09-01

    With the increasing popularity of video streaming services and multimedia sharing via social networks, there is a need to protect the multimedia from malicious use. An attacker may use steganography and watermarking techniques to embed malicious content, in order to attack the end user. Most of the attack algorithms are robust to basic image processing techniques such as filtering, compression, noise addition, etc. Hence, in this article two novel, real-time, defense techniques are proposed: Smart threshold and anomaly correction. Both techniques operate at the DCT domain, and are applicable for JPEG images and H.264 I-Frames. The defense performance was evaluated against a highly robust attack, and the perceptual quality degradation was measured by the well-known PSNR and SSIM quality assessment metrics. A set of defense techniques is suggested for improving the defense efficiency. For the most aggressive attack configuration, the combination of all the defense techniques results in 80% protection against cyber-attacks with PSNR of 25.74 db.

  18. Comparison of a new noncoplanar intensity-modulated radiation therapy technique for craniospinal irradiation with 3 coplanar techniques

    DEFF Research Database (Denmark)

    Hansen, Anders T; Lukacova, Slavka; Lassen-Ramshad, Yasmin A.

    2015-01-01

    When standard conformal x-ray technique for craniospinal irradiation is used, it is a challenge to achieve satisfactory dose coverage of the target including the area of the cribriform plate, while sparing organs at risk. We present a new intensity-modulated radiation therapy (IMRT), noncoplanar...... patient using the noncoplanar IMRT-based technique, a coplanar IMRT-based technique, and a coplanar volumetric-modulated arch therapy (VMAT) technique. Dosimetry data for all patients were compared with the corresponding data from the conventional treatment plans. The new noncoplanar IMRT technique...... substantially reduced the mean dose to organs at risk compared with the standard radiation technique. The 2 other coplanar techniques also reduced the mean dose to some of the critical organs. However, this reduction was not as substantial as the reduction obtained by the noncoplanar technique. Furthermore...

  19. Airway Clearance Techniques (ACTs)

    Medline Plus

    Full Text Available ... to loosen mucus from airway walls. See how different airway clearance techniques work to help you clear the thick, sticky mucus ... Offer their tips for fitting ACTs into daily life Airway Clearance Techniques | Webcast ... Facebook Twitter ...

  20. Biomechanical comparison of the double-push technique and the conventional skate skiing technique in cross-country sprint skiing.

    Science.gov (United States)

    Stöggl, Thomas; Müller, Erich; Lindinger, Stefan

    2008-09-01

    The aims of the study were to: (1) adapt the "double-push" technique from inline skating to cross-country skiing; (2) compare this new skiing technique with the conventional skate skiing cross-country technique; and (3) test the hypothesis that the double-push technique improves skiing speed in a short sprint. 13 elite skiers performed maximum-speed sprints over 100 m using the double-push skate skiing technique and using the conventional "V2" skate skiing technique. Pole and plantar forces, knee angle, cycle characteristics, and electromyography of nine lower body muscles were analysed. We found that the double-push technique could be successfully transferred to cross-country skiing, and that this new technique is faster than the conventional skate skiing technique. The double-push technique was 2.9 +/- 2.2% faster (P push technique had a longer cycle length and a lower cycle rate, and it was characterized by higher muscle activity, higher knee extension amplitudes and velocities, and higher peak foot forces, especially in the first phase of the push-off. Also, the foot was more loaded laterally in the double-push technique than in the conventional skate skiing technique.

  1. Legal technique: approaches to section on types

    Directory of Open Access Journals (Sweden)

    І. Д. Шутак

    2015-11-01

    Full Text Available Legal technique is a branch of knowledge about the rules of doing legal work and creating in the process a variety of legal documents, which had previously been part of the theory of law. In modern conditions of the legal technique are isolated in a separate branch of legal science, focused on solving practical problems. The purpose of this article is to analyze the types of legal techniques, in particular, on the basis of theoretical propositions about legal technique to allocate substantial characteristics and types of legal technique. O. Malko and M. Matuzov consider legal technique as a set of rules, techniques, methods of preparation, creation, registration of legal documents, their classification and accounting for their excellence, efficient use. A similar meaning is investing in this concept Alekseev, determining that the legal technique is a set of tools and techniques used in accordance with accepted rules in the formulation and systematization of legal acts to ensure their perfection. So, legal technique – theoretical and applied legal science, which studies the regularities of rational legal practice in the creation, interpretation and implementation of law. In relation to the type of legal techniques in the literature proposed different classifications. For example, G. Muromtsev technique, which is used only in the field of law, divide on the technique of law-making (legislative technique, technique of law enforcement, interpretation, technique of judicial speech, interrogation, notarial activities. V. Kartashov shared legal technique on law making and enforcement (prorealtime, interpretive yourself and prevacidrebatezw, judicial or investigative, prosecutorial, and the like. Some authors clearly indicate that the criterion by which to distinguish types of legal techniques. So, S. Alekseev notes that legal technique is classified from the point of view of the legal nature of the act made on: a techniques of legal acts; b the

  2. Analytical system availability techniques

    NARCIS (Netherlands)

    Brouwers, J.J.H.; Verbeek, P.H.J.; Thomson, W.R.

    1987-01-01

    Analytical techniques are presented to assess the probability distributions and related statistical parameters of loss of production from equipment networks subject to random failures and repairs. The techniques are based on a theoretical model for system availability, which was further developed

  3. GPU Pro advanced rendering techniques

    CERN Document Server

    Engel, Wolfgang

    2010-01-01

    This book covers essential tools and techniques for programming the graphics processing unit. Brought to you by Wolfgang Engel and the same team of editors who made the ShaderX series a success, this volume covers advanced rendering techniques, engine design, GPGPU techniques, related mathematical techniques, and game postmortems. A special emphasis is placed on handheld programming to account for the increased importance of graphics on mobile devices, especially the iPhone and iPod touch.Example programs and source code can be downloaded from the book's CRC Press web page. 

  4. EDITORIAL: Measurement techniques for multiphase flows Measurement techniques for multiphase flows

    Science.gov (United States)

    Okamoto, Koji; Murai, Yuichi

    2009-11-01

    Research on multiphase flows is very important for industrial applications, including power stations, vehicles, engines, food processing and so on. Multiphase flows originally have nonlinear features because of multiphase systems. The interaction between the phases plays a very interesting role in the flows. The nonlinear interaction causes the multiphase flows to be very complicated. Therefore techniques for measuring multiphase flows are very useful in helping to understand the nonlinear phenomena. The state-of-the-art measurement techniques were presented and discussed at the sixth International Symposium on Measurement Techniques for Multiphase Flows (ISMTMF2008) held in Okinawa, Japan, on 15-17 December 2008. This special feature of Measurement Science and Technology includes selected papers from ISMTMF2008. Okinawa has a long history as the Ryukyus Kingdom. China, Japan and many western Pacific countries have had cultural and economic exchanges through Okinawa for over 1000 years. Much technical and scientific information was exchanged at the symposium in Okinawa. The proceedings of ISMTMF2008 apart from these special featured papers were published in Journal of Physics: Conference Series vol. 147 (2009). We would like to express special thanks to all the contributors to the symposium and this special feature. This special feature will be a milestone in measurement techniques for multiphase flows.

  5. Management for Patients with De Novo or Recurrent Tumors in the Residual Kidney after Surgery for Nonfamilial Bilateral Renal Cell Carcinoma

    Directory of Open Access Journals (Sweden)

    Noboru Hara

    2009-01-01

    Full Text Available The tumor de novo in the residual kidney after surgery for nonfamilial bilateral renal cell carcinoma (RCC is problematic. We reviewed 5 patients who experienced such a situation. Three patients had had metachronous bilateral RCC, treated with radical nephrectomy in one kidney and nephron-sparing surgery (NSS in the other. Two patients had had synchronous disease; one patient had received radical nephrectomy and NSS, and the other bilateral NSS. The 5 patients had another solid mass/de novo tumor in the residual kidney 16–88 (mean 46.8 months after surgery. For the tumor de novo in earlier years (1992–1999, one patient underwent surgery and hemodialysis, and the other selected a conservative observation. In recent years (2000–2007, one patient was conservatively observed; the remaining 2 received computerized-tomography-guided radiofrequency ablation, and the local tumors were well controlled postoperatively for 20 and 12 months with their renal function unimpaired. Ablative techniques can potentially strike a balance between oncological and nephrological outcomes in patients with sporadic multiple RCC, successful management of which was difficult previously.

  6. Ethical Use of Gestalt Techniques.

    Science.gov (United States)

    Given, Jane A.

    The purpose of this paper is to engender a healthy respect for Gestalt theory and techniques and the use of the techniques in the client's best interest and in the interest of positive professional and self-development in the practitioner. An overview of Gestalt techniques is provided, concentrating on the two category divisions of experiments and…

  7. Advanced in-flight measurement techniques

    CERN Document Server

    Lawson, Nicholas; Jentink, Henk; Kompenhans, Jürgen

    2013-01-01

    The book presents a synopsis of the main results achieved during the 3 year EU-project "Advanced Inflight Measurement Techniques (AIM)" which applied advanced image based measurement techniques to industrial flight testing. The book is intended to be not only an overview on the AIM activities but also a guide on the application of advanced optical measurement techniques for future flight testing. Furthermore it is a useful guide for engineers in the field of experimental methods and flight testing who face the challenge of a future requirement for the development of highly accurate non-intrusive in-flight measurement techniques.

  8. [Impressions techniques--Part 2].

    Science.gov (United States)

    Levartovsky, S; Masri, M; Alter, E; Pilo, R

    2012-10-01

    A dental impression is a positive replica of the teeth, the surrounding gingiva and the border between them; the purpose of which is to create an accurate master model. Two major techniques for impressions exist today: The conventional and the digital impressions. The current article describes both techniques. In the conventional impressions, it is important to choose a proper tray, stock or custom, and to mix the material properly. The commonly used impression techniques for making a conventional impression are described with a review on the effect of the technique on its accuracy. The effect of the wash bulk on the accuracy of the stone dies and/or the restoration is discussed, as well. The digital impressions with their advantages and disadvantages are described in comparison to the conventional impressions. Although, digital impressions eliminate some of the negative characteristics of conventional impressions, proper soft-tissue management and isolation of tooth preparation margins is still mandatory.

  9. Orbital welding technique

    International Nuclear Information System (INIS)

    Hoeschen, W.

    2003-01-01

    The TIG (Tungsten-inert gas) orbital welding technique is applied in all areas of pipe welding. The process is mainly used for austenitic and ferritic materials but also for materials like aluminium, nickel, and titanium alloys are commonly welded according to this technique. Thin-walled as well as thick-walled pipes are welded economically. The application of orbital welding is of particular interest in the area of maintenance of thick-walled pipes that is described in this article. (orig.) [de

  10. Biomonitoring of Environmental Status and Trends (BEST) Program: Selected Methods for Monitoring Chemical Contaminants and their Effects in Aquatic Ecosystems

    Science.gov (United States)

    2000-02-01

    1995. New nephron devel- opment in fish from polluted waters: a possi- ble biomarker. Ecotoxicology 4:157-68. Couch JA. 1985. Prospective study of...Carlson AR. 1998. Comparative sensitivity of five species of macrophytes and six species of algae to atrazine, metribuzin, alachlor, and meto...Stevenson JC, Jones TW, Means JC. 1985. Effects of atrazine and linuron on photosynthesis and growth of the macrophytes Potamogeton per- foliatus L

  11. Effect of cisplatin on renal haemodynamics and tubular function in the dog kidney

    DEFF Research Database (Denmark)

    Daugaard, G; Abildgaard, U; Holstein-Rathlou, N H

    1987-01-01

    Administration of cisplatin (5 mg/kg) to dogs results in polyuric renal failure due initially to a proximal tubular functional impairment. 48-72 h after the cisplatin administration the depressed renal function can be attributed to impairment of proximal as well as distal tubular reabsorptive cap...... capacities associated with increased renal vascular resistance. The polyuria seems to be due to the impaired reabsorption rate in the distal nephron segments....

  12. Analysis and analytical techniques

    Energy Technology Data Exchange (ETDEWEB)

    Batuecas Rodriguez, T [Department of Chemistry and Isotopes, Junta de Energia Nuclear, Madrid (Spain)

    1967-01-01

    The technology associated with the use of organic coolants in nuclear reactors depends to a large extent on the determination and control of their physical and chemical properties, and particularly on the viability, speed, sensitivity, precision and accuracy (depending on the intended usage) of the methods employed in detection and analytical determination. This has led to the study and development of numerous techniques, some specially designed for the extreme conditions involved in working with the types of product in question and others adapted from existing techniques. In the specific case of polyphenyl and hydropolyphenyl mixtures, which have been the principal subjects of study to date and offer greatest promise, the analytical problems are broadly as follows: Composition of initial product or virgin coolant composition of macro components and amounts of organic and inorganic impurities; Coolant during and after operation. Determination of gases and organic compounds produced by pyrolysis and radiolysis (degradation and polymerization products); Control of systems for purifying and regenerating the coolant after use. Dissolved pressurization gases; Detection of intermediate products during decomposition; these are generally very unstable (free radicals); Degree of fouling and film formation. Tests to determine potential formation of films; Corrosion of structural elements and canning materials; Health and safety. Toxicity, inflammability and impurities that can be activated. Although some of the above problems are closely interrelated and entail similar techniques, they vary as to degree of difficulty. Another question is the difficulty of distinguishing clearly between techniques for determining physical and physico-chemical properties, on one hand, and analytical techniques on the other. Any classification is therefore somewhat arbitrary (for example, in the case of dosimetry and techniques for determining mean molecular weights or electrical conductivity

  13. Anatomic partial nephrectomy: technique evolution.

    Science.gov (United States)

    Azhar, Raed A; Metcalfe, Charles; Gill, Inderbir S

    2015-03-01

    Partial nephrectomy provides equivalent long-term oncologic and superior functional outcomes as radical nephrectomy for T1a renal masses. Herein, we review the various vascular clamping techniques employed during minimally invasive partial nephrectomy, describe the evolution of our partial nephrectomy technique and provide an update on contemporary thinking about the impact of ischemia on renal function. Recently, partial nephrectomy surgical technique has shifted away from main artery clamping and towards minimizing/eliminating global renal ischemia during partial nephrectomy. Supported by high-fidelity three-dimensional imaging, novel anatomic-based partial nephrectomy techniques have recently been developed, wherein partial nephrectomy can now be performed with segmental, minimal or zero global ischemia to the renal remnant. Sequential innovations have included early unclamping, segmental clamping, super-selective clamping and now culminating in anatomic zero-ischemia surgery. By eliminating 'under-the-gun' time pressure of ischemia for the surgeon, these techniques allow an unhurried, tightly contoured tumour excision with point-specific sutured haemostasis. Recent data indicate that zero-ischemia partial nephrectomy may provide better functional outcomes by minimizing/eliminating global ischemia and preserving greater vascularized kidney volume. Contemporary partial nephrectomy includes a spectrum of surgical techniques ranging from conventional-clamped to novel zero-ischemia approaches. Technique selection should be tailored to each individual case on the basis of tumour characteristics, surgical feasibility, surgeon experience, patient demographics and baseline renal function.

  14. Telescopes and Techniques

    CERN Document Server

    Kitchin, C R

    2013-01-01

    Telescopes and Techniques has proved itself in its first two editions, having become probably one of the most widely used astronomy texts, both for amateur astronomers and astronomy and astrophysics undergraduates. Both earlier editions of the book were widely used for introductory practical astronomy courses in many universities. In this Third Edition the author guides the reader through the mathematics, physics and practical techniques needed to use today's telescopes (from the smaller models to the larger instruments installed in many colleges) and how to find objects in the sky. Most of the physics and engineering involved is described fully and requires little prior knowledge or experience. Both visual and electronic imaging techniques are covered, together with an introduction to how data (measurements) should be processed and analyzed. A simple introduction to radio telescopes is also included. Brief coverage of the more advanced topics of photometry and spectroscopy are included, but mainly to enable ...

  15. A Technique: Exposure Therapy

    Directory of Open Access Journals (Sweden)

    Serkan AKKOYUNLU

    2013-08-01

    Conclusion: Exposure with response prevention is a basic and effective technique. Every cognitive behavior therapist must be able to implement this technique and be cognizant of pearls of this procedure. (Journal of Cognitive Behavioral Psychotherapy and Research 2013, 2: 121-128 [JCBPR 2013; 2(2.000: 121-128

  16. Techniques of radiation dosimetry

    International Nuclear Information System (INIS)

    Mahesk, K.

    1985-01-01

    A text and reference with an interdisciplinary approach to physics, atomic energy, radiochemistry, and radiobiology. Chapters examine basic principles, experimental techniques, the methodology of dose experiments, and applications. Treats 14 different dosimetric techniques, including ionization chamber, thermoluminescence, and lyoluminescence. Considers the conceptual aspects and characteristic features of radiation

  17. Adaptive algebraic reconstruction technique

    International Nuclear Information System (INIS)

    Lu Wenkai; Yin Fangfang

    2004-01-01

    Algebraic reconstruction techniques (ART) are iterative procedures for reconstructing objects from their projections. It is proven that ART can be computationally efficient by carefully arranging the order in which the collected data are accessed during the reconstruction procedure and adaptively adjusting the relaxation parameters. In this paper, an adaptive algebraic reconstruction technique (AART), which adopts the same projection access scheme in multilevel scheme algebraic reconstruction technique (MLS-ART), is proposed. By introducing adaptive adjustment of the relaxation parameters during the reconstruction procedure, one-iteration AART can produce reconstructions with better quality, in comparison with one-iteration MLS-ART. Furthermore, AART outperforms MLS-ART with improved computational efficiency

  18. Millimicrosecond pulse techniques

    CERN Document Server

    Lewis, Ian A D

    1959-01-01

    Millimicrosecond Pulse Techniques, Second Edition focuses on millimicrosecond pulse techniques and the development of devices of large bandwidth, extending down to comparatively low frequencies (1 Mc/s). Emphasis is on basic circuit elements and pieces of equipment of universal application. Specific applications, mostly in the field of nuclear physics instrumentation, are considered. This book consists of eight chapters and opens with an introduction to some of the terminology employed by circuit engineers as well as theoretical concepts, including the laws of circuit analysis, Fourier analysi

  19. Combination of behavioural and cognitive techniques

    Directory of Open Access Journals (Sweden)

    Leonida Rotvejn Pajič

    2001-03-01

    Full Text Available The cognitive - behavioral approach in the treatment of behavioral disorders, emotional disorders and learning difficulties is not limited to a single theoretical principle or technique, but integrates different techniques. The variants techniques are derived from theoretical and empirical findings in different domains of developmental psychology (self-control, social cognition, memory, metacognitive and attritional processes. The aim of the article is to present some basic cognitive and behavioral techniques that are individually adapted during therapy and mutually complete each other. A practical case of combining techniques is presented.

  20. Does technique matter; a pilot study exploring weighting techniques for a multi-criteria decision support framework.

    Science.gov (United States)

    van Til, Janine; Groothuis-Oudshoorn, Catharina; Lieferink, Marijke; Dolan, James; Goetghebeur, Mireille

    2014-01-01

    There is an increased interest in the use of multi-criteria decision analysis (MCDA) to support regulatory and reimbursement decision making. The EVIDEM framework was developed to provide pragmatic multi-criteria decision support in health care, to estimate the value of healthcare interventions, and to aid in priority-setting. The objectives of this study were to test 1) the influence of different weighting techniques on the overall outcome of an MCDA exercise, 2) the discriminative power in weighting different criteria of such techniques, and 3) whether different techniques result in similar weights in weighting the criteria set proposed by the EVIDEM framework. A sample of 60 Dutch and Canadian students participated in the study. Each student used an online survey to provide weights for 14 criteria with two different techniques: a five-point rating scale and one of the following techniques selected randomly: ranking, point allocation, pairwise comparison and best worst scaling. The results of this study indicate that there is no effect of differences in weights on value estimates at the group level. On an individual level, considerable differences in criteria weights and rank order occur as a result of the weight elicitation method used, and the ability of different techniques to discriminate in criteria importance. Of the five techniques tested, the pair-wise comparison of criteria has the highest ability to discriminate in weights when fourteen criteria are compared. When weights are intended to support group decisions, the choice of elicitation technique has negligible impact on criteria weights and the overall value of an innovation. However, when weights are used to support individual decisions, the choice of elicitation technique influences outcome and studies that use dissimilar techniques cannot be easily compared. Weight elicitation through pairwise comparison of criteria is preferred when taking into account its superior ability to discriminate between

  1. The Delphi Technique in Educational Research

    Directory of Open Access Journals (Sweden)

    Ravonne A. Green

    2014-04-01

    Full Text Available The Delphi Technique has been useful in educational settings in forming guidelines, standards, and in predicting trends. Judd lists these major uses of the Delphi Technique in higher education: (a cost-effectiveness, (b cost–benefit analysis, (c curriculum and campus planning, and (d university-wide educational goals and objectives. The thorough Delphi researcher seeks to reconcile the Delphi consensus with current literature, institutional research, and the campus environment. This triangle forms a sound base for responsible research practice. This book gives an overview of the Delphi Technique and the primary uses of this technique in research. This article on the Delphi Technique will give the researcher an invaluable resource for learning about the Delphi Technique and for applying this method in educational research projects.

  2. Relaxation techniques for stress

    Science.gov (United States)

    ... raise your heart rate. This is called the stress response. Relaxation techniques can help your body relax and lower your blood pressure ... also many other types of breathing techniques you can learn. In many cases, you do not need much ... including those that cause stress. Meditation has been practiced for thousands of years, ...

  3. Diagnostic techniques

    International Nuclear Information System (INIS)

    Berquist, T.H.; Bender, C.E.; James, E.M.; Brown, M.L.; McLeod, R.A.; Broderick, D.F.; Welch, T.J.

    1989-01-01

    Proper application of imaging procedures is essential to obtain needed information for diagnosis and therapy planning in patients with suspected foot and/or ankle pathology. This paper provides basic background data for the numerous imaging techniques

  4. Strongly correlated systems experimental techniques

    CERN Document Server

    Mancini, Ferdinando

    2015-01-01

    The continuous evolution and development of experimental techniques is at the basis of any fundamental achievement in modern physics. Strongly correlated systems (SCS), more than any other, need to be investigated through the greatest variety of experimental techniques in order to unveil and crosscheck the numerous and puzzling anomalous behaviors characterizing them. The study of SCS fostered the improvement of many old experimental techniques, but also the advent of many new ones just invented in order to analyze the complex behaviors of these systems. Many novel materials, with functional properties emerging from macroscopic quantum behaviors at the frontier of modern research in physics, chemistry and materials science, belong to this class of systems. The volume presents a representative collection of the modern experimental techniques specifically tailored for the analysis of strongly correlated systems. Any technique is presented in great detail by its own inventor or by one of the world-wide recognize...

  5. Two sampling techniques for game meat

    Directory of Open Access Journals (Sweden)

    Maretha van der Merwe

    2013-03-01

    Full Text Available A study was conducted to compare the excision sampling technique used by the export market and the sampling technique preferred by European countries, namely the biotrace cattle and swine test. The measuring unit for the excision sampling was grams (g and square centimetres (cm2 for the swabbing technique. The two techniques were compared after a pilot test was conducted on spiked approved beef carcasses (n = 12 that statistically proved the two measuring units correlated. The two sampling techniques were conducted on the same game carcasses (n = 13 and analyses performed for aerobic plate count (APC, Escherichia coli and Staphylococcus aureus, for both techniques. A more representative result was obtained by swabbing and no damage was caused to the carcass. Conversely, the excision technique yielded fewer organisms and caused minor damage to the carcass. The recovery ratio from the sampling technique improved 5.4 times for APC, 108.0 times for E. coli and 3.4 times for S. aureus over the results obtained from the excision technique. It was concluded that the sampling methods of excision and swabbing can be used to obtain bacterial profiles from both export and local carcasses and could be used to indicate whether game carcasses intended for the local market are possibly on par with game carcasses intended for the export market and therefore safe for human consumption.

  6. Two sampling techniques for game meat.

    Science.gov (United States)

    van der Merwe, Maretha; Jooste, Piet J; Hoffman, Louw C; Calitz, Frikkie J

    2013-03-20

    A study was conducted to compare the excision sampling technique used by the export market and the sampling technique preferred by European countries, namely the biotrace cattle and swine test. The measuring unit for the excision sampling was grams (g) and square centimetres (cm2) for the swabbing technique. The two techniques were compared after a pilot test was conducted on spiked approved beef carcasses (n = 12) that statistically proved the two measuring units correlated. The two sampling techniques were conducted on the same game carcasses (n = 13) and analyses performed for aerobic plate count (APC), Escherichia coli and Staphylococcus aureus, for both techniques. A more representative result was obtained by swabbing and no damage was caused to the carcass. Conversely, the excision technique yielded fewer organisms and caused minor damage to the carcass. The recovery ratio from the sampling technique improved 5.4 times for APC, 108.0 times for E. coli and 3.4 times for S. aureus over the results obtained from the excision technique. It was concluded that the sampling methods of excision and swabbing can be used to obtain bacterial profiles from both export and local carcasses and could be used to indicate whether game carcasses intended for the local market are possibly on par with game carcasses intended for the export market and therefore safe for human consumption.

  7. Informationization nuclear apparatus communication technique

    International Nuclear Information System (INIS)

    Yu Tiqi; Fang Zongliang; Wen Qilin

    2006-01-01

    The paper explains the request of communication ability in nuclear technique application area. Based on the actuality of nuclear apparatus communication ability, and mainly combining with the development of communication technique, the authors analyzes the application trend of communication technique applying in nuclear apparatus, for the apparatus and system needing communication ability, they need selecting suitable communication means to make them accomplish the task immediately and effectively. (authors)

  8. Applying Brainstorming Techniques to EFL Classroom

    OpenAIRE

    Toshiya, Oishi; 湘北短期大学; aPart-time Lecturer at Shohoku College

    2015-01-01

    This paper focuses on brainstorming techniques for English language learners. From the author's teaching experiences at Shohoku College during the academic year 2014-2015, the importance of brainstorming techniques was made evident. The author explored three elements of brainstorming techniques for writing using literaturereviews: lack of awareness, connecting to prior knowledge, and creativity. The literature reviews showed the advantage of using brainstorming techniques in an English compos...

  9. Enseignement technique : Séminaire de l'enseigement technique

    CERN Multimedia

    2004-01-01

    Mardi 4 mai 2004 SEMINAIRE DE L'ENSEIGNEMENT TECHNIQUE de 14:00 à 17:00 - Training Centre Auditorium - bât. 593 Le SPC - Statistical Process Control - dans une démarche de qualité totale Hakim Bourahla, Maurice Arrius, Charbel Tannous - ABW Concept - F-74950 SCIONZIER, France Ce nouveau séminaire de l'Enseignement Technique sera consacré à la présentation du SPC, le Statistical Process Control. Le SPC apporte une grande efficacité dans l'amélioration de la qualité des produits. Cette méthode, permettant d'assurer une qualité optimum à l'aide d'un outil statistique, est fondée sur deux concepts de base : le suivi et le pilotage des procédés industriels par cartes de contrôle, et l'étude des capabilités des systèmes de production. - Origine et objectifs du SPC - Concepts du ...

  10. Enseignement technique : Séminaire de l'enseignement technique

    CERN Multimedia

    2004-01-01

    Mardi 4 mai 2004 SEMINAIRE DE L'ENSEIGNEMENT TECHNIQUE de 14:00 à 17:00 - Training Centre Auditorium - bât. 593 Le SPC - Statistical Process Control - dans une démarche de qualité totale Hakim Bourahla, Maurice Arrius, Charbel Tannous - ABW Concept - F-74950 SCIONZIER, France Ce nouveau séminaire de l'Enseignement Technique sera consacré à la présentation du SPC, le Statistical Process Control. Le SPC apporte une grande efficacité dans l'amélioration de la qualité des produits. Cette méthode, permettant d'assurer une qualité optimum à l'aide d'un outil statistique, est fondée sur deux concepts de base : le suivi et le pilotage des procédés industriels par cartes de contrôle, et l'étude des capabilités des systèmes de production. - Origine et objectifs du SPC - Concepts du ...

  11. Hyphenated analytical techniques for materials characterisation

    International Nuclear Information System (INIS)

    Armstrong, Gordon; Kailas, Lekshmi

    2017-01-01

    This topical review will provide a survey of the current state of the art in ‘hyphenated’ techniques for characterisation of bulk materials, surface, and interfaces, whereby two or more analytical methods investigating different properties are applied simultaneously to the same sample to better characterise the sample than can be achieved by conducting separate analyses in series using different instruments. It is intended for final year undergraduates and recent graduates, who may have some background knowledge of standard analytical techniques, but are not familiar with ‘hyphenated’ techniques or hybrid instrumentation. The review will begin by defining ‘complementary’, ‘hybrid’ and ‘hyphenated’ techniques, as there is not a broad consensus among analytical scientists as to what each term means. The motivating factors driving increased development of hyphenated analytical methods will also be discussed. This introduction will conclude with a brief discussion of gas chromatography-mass spectroscopy and energy dispersive x-ray analysis in electron microscopy as two examples, in the context that combining complementary techniques for chemical analysis were among the earliest examples of hyphenated characterisation methods. The emphasis of the main review will be on techniques which are sufficiently well-established that the instrumentation is commercially available, to examine physical properties including physical, mechanical, electrical and thermal, in addition to variations in composition, rather than methods solely to identify and quantify chemical species. Therefore, the proposed topical review will address three broad categories of techniques that the reader may expect to encounter in a well-equipped materials characterisation laboratory: microscopy based techniques, scanning probe-based techniques, and thermal analysis based techniques. Examples drawn from recent literature, and a concluding case study, will be used to explain the

  12. Hyphenated analytical techniques for materials characterisation

    Science.gov (United States)

    Armstrong, Gordon; Kailas, Lekshmi

    2017-09-01

    This topical review will provide a survey of the current state of the art in ‘hyphenated’ techniques for characterisation of bulk materials, surface, and interfaces, whereby two or more analytical methods investigating different properties are applied simultaneously to the same sample to better characterise the sample than can be achieved by conducting separate analyses in series using different instruments. It is intended for final year undergraduates and recent graduates, who may have some background knowledge of standard analytical techniques, but are not familiar with ‘hyphenated’ techniques or hybrid instrumentation. The review will begin by defining ‘complementary’, ‘hybrid’ and ‘hyphenated’ techniques, as there is not a broad consensus among analytical scientists as to what each term means. The motivating factors driving increased development of hyphenated analytical methods will also be discussed. This introduction will conclude with a brief discussion of gas chromatography-mass spectroscopy and energy dispersive x-ray analysis in electron microscopy as two examples, in the context that combining complementary techniques for chemical analysis were among the earliest examples of hyphenated characterisation methods. The emphasis of the main review will be on techniques which are sufficiently well-established that the instrumentation is commercially available, to examine physical properties including physical, mechanical, electrical and thermal, in addition to variations in composition, rather than methods solely to identify and quantify chemical species. Therefore, the proposed topical review will address three broad categories of techniques that the reader may expect to encounter in a well-equipped materials characterisation laboratory: microscopy based techniques, scanning probe-based techniques, and thermal analysis based techniques. Examples drawn from recent literature, and a concluding case study, will be used to explain the

  13. Microscopy techniques in flavivirus research.

    Science.gov (United States)

    Chong, Mun Keat; Chua, Anthony Jin Shun; Tan, Terence Tze Tong; Tan, Suat Hoon; Ng, Mah Lee

    2014-04-01

    The Flavivirus genus is composed of many medically important viruses that cause high morbidity and mortality, which include Dengue and West Nile viruses. Various molecular and biochemical techniques have been developed in the endeavour to study flaviviruses. However, microscopy techniques still have irreplaceable roles in the identification of novel virus pathogens and characterization of morphological changes in virus-infected cells. Fluorescence microscopy contributes greatly in understanding the fundamental viral protein localizations and virus-host protein interactions during infection. Electron microscopy remains the gold standard for visualizing ultra-structural features of virus particles and infected cells. New imaging techniques and combinatory applications are continuously being developed to push the limit of resolution and extract more quantitative data. Currently, correlative live cell imaging and high resolution three-dimensional imaging have already been achieved through the tandem use of optical and electron microscopy in analyzing biological specimens. Microscopy techniques are also used to measure protein binding affinities and determine the mobility pattern of proteins in cells. This chapter will consolidate on the applications of various well-established microscopy techniques in flavivirus research, and discuss how recently developed microscopy techniques can potentially help advance our understanding in these membrane viruses. Copyright © 2013 Elsevier Ltd. All rights reserved.

  14. Teaching Speaking Through Debate Technique

    Directory of Open Access Journals (Sweden)

    . Suranto

    2016-07-01

    Full Text Available Abstract : Teaching Speaking Through Debate Technique. Speaking is one of the basic competence from the other fourth basic competence (listening, speaking, reading and writing. Speaking ability should be mastered by every students, in order to achieve that competence students should be given the right technique to study sepaking. The successfull of the students speaking can be seen from their ability to express idea, thought and feeling through speaking. The objective of this Action Research is to improve students’s oral communication skill through the debate technique. This study was conducted at MA Ma’arif Nu 5 Sekampung Lampung Timur from March to April 2014. The research data were taken from students in the eleventh class, with 28 students and analyzed qualitatively and quantitatively. The research findings indicate that there are improvements in students’ english speaking skill through the debate technique. By analyzing data qualitatively and quantitatively from the end of the first cycle to the second cycle and it was found that the students’ English speaking skill increased 20,9% over the standard that has been determined by the researcher that is 65%. The researcher concludes that the students’ english speaking skill can be improve through the debate technique in learning process.   Key words : action research, debate technique, english speaking skill

  15. Highly reliable TOFD UT Technique

    International Nuclear Information System (INIS)

    Acharya, G.D.; Trivedi, S.A.R.; Pai, K.B.

    2003-01-01

    The high performance of the time of flight diffraction technique (TOFD) with regard to the detection capabilities of weld defects such as crack, slag, lack of fusion has led to a rapidly increasing acceptance of the technique as a pre?service inspection tool. Since the early 1990s TOFD has been applied to several projects, where it replaced the commonly used radiographic testing. The use of TOM lead to major time savings during new build and replacement projects. At the same time the TOFD technique was used as base line inspection, which enables monitoring in the future for critical welds, but also provides documented evidence for life?time. The TOFD technique as the ability to detect and simultaneously size flows of nearly any orientation within the weld and heat affected zone. TOM is recognized as a reliable, proven technique for detection and sizing of defects and proven to be a time saver, resulting in shorter shutdown periods and construction project times. Thus even in cases where inspection price of TOFD per welds is higher, in the end it will result in significantly lower overall costs and improve quality. This paper deals with reliability, economy, acceptance criteria and field experience. It also covers comparative study between radiography technique Vs. TOFD. (Author)

  16. Lymphography - an outdated technique

    International Nuclear Information System (INIS)

    Peters, P.E.

    1982-01-01

    The indications for lymphography have changed with the availability of non-invasive techniques like ultrasonic techniques and computerized tomography. This review discusses: Recent results of lymphography in histologically verified patient collectives with lymphatic systemic diseases and lymphatic metastizing tumors. The present role of lymphography is derived from this status report as well as the future perspectives. (orig.) [de

  17. Progressive glomerulosclerosis and renal failure following perinatal gamma radiation in the beagle

    International Nuclear Information System (INIS)

    Jaenke, R.S.; Phemister, R.D.; Norrdin, R.W.

    1980-01-01

    The renal effects of whole body irradiation in the perinatal period were studied in the dog. Ninety-three dogs received a single sublethal exposure in the range of 270 to 435 R in either late gestation (55 days postcoitus) or early postnatal life (2 days postpartum) and were sacrificed at 70 days, 2, or 4 years of age. Early renal lesions in 70-day-old irradiated dogs were characterized by arrested glomerular maturation and degeneration resulting in reduced functional renal mass. Mature glomeruli exhibited mesangial proliferation. At 2 and 4 years of age, surviving irradiated dogs exhibited sever renal disease associated with progressive glomerular damage which was characterized by mesangial proliferation and compression of capillary lumina, epithelial degeneration and focal capsular adhesions, and ultimately obliterative glomerulosclerosis. Twenty-one of the 93 irradiated dogs died in renal failure before 4 years of age with advanced glomerulosclerosis. The phatogenesis of this progressive renal lesion may be related to the interaction of three specific factors. These include (1) the effect of direct radiation damage to mature kidney components; (2) the loss of outer cortical nephrons resulting in increased work load of the surviving nephrons; and (3) the effect of compensatory hypertrophy related to the loss of renal parenchyma as the rapid growth rates associated with kidney maturation

  18. Precision Medicine for Acute Kidney Injury (AKI): Redefining AKI by Agnostic Kidney Tissue Interrogation and Genetics.

    Science.gov (United States)

    Kiryluk, Krzysztof; Bomback, Andrew S; Cheng, Yim-Ling; Xu, Katherine; Camara, Pablo G; Rabadan, Raul; Sims, Peter A; Barasch, Jonathan

    2018-01-01

    Acute kidney injury (AKI) currently is diagnosed by a temporal trend of a single blood analyte: serum creatinine. This measurement is neither sensitive nor specific to kidney injury or its protean forms. Newer biomarkers, neutrophil gelatinase-associated lipocalin (NGAL, Lipocalin 2, Siderocalin), or kidney injury molecule-1 (KIM-1, Hepatitis A Virus Cellular Receptor 1), accelerate the diagnosis of AKI as well as prospectively distinguish rapidly reversible from prolonged causes of serum creatinine increase. Nonetheless, these biomarkers lack the capacity to subfractionate AKI further (eg, sepsis versus ischemia versus nephrotoxicity from medications, enzymes, or metals) or inform us about the primary and secondary sites of injury. It also is unknown whether all nephrons are injured in AKI, whether all cells in a nephron are affected, and whether injury responses can be stimulus-specific or cell type-specific or both. In this review, we summarize fully agnostic tissue interrogation approaches that may help to redefine AKI in cellular and molecular terms, including single-cell and single-nuclei RNA sequencing technology. These approaches will empower a shift in the current paradigm of AKI diagnosis, classification, and staging, and provide the renal community with a significant advance toward precision medicine in the analysis AKI. Copyright © 2017 Elsevier Inc. All rights reserved.

  19. An experimental study on recovery of renal function using 99mTc DMSA scintigram after percutaneous nephrostomy in unilateral hydronephrosis

    International Nuclear Information System (INIS)

    Moon, Tae Yong; Nam, Sang Hwa; Park, Jong Yeon; Kim, Byung Soo

    1992-01-01

    Obstruction on the urinary tract eventually results in damage to the kidneys and lose of function. The questions that concern the clinician are the degree of nephron loss in that kidney and potential for recovery following the relief of obstruction. 99m Tc DMSA accumulates in tubule cells and has been proposed as a marker of the tubular mass. The authors estimated the renal uptake ratio of 99m Tc DMSA for the degree of nephron loss corresponding to duration of hydronephrosis following left ureteral ligation in 5 New Zealand white rabbits and the potential for recovery following percutaneous nephrostomy of hydronephrosis in 24 rabbits. While the renal uptake ratio of 99m Tc DMSA of the kidney with unilateral hydronephrosis following ureteral ligation reduced dramatically within 24 hour, that of the opposite healthy kidney increased, and the total renal uptake ratio was same as normal functioning kidneys before ureteral ligation. Upon ureteral release, there was no evidence of definite recovery or impairment in the experimental kidneys for 5 days. The authors conclude that a combination of ureteral release and administration of some drugs such as renal vasodilator or diuretics is an appropriate treatment for the recovery of function in unilateral hydronephrosis

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

    Directory of Open Access Journals (Sweden)

    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.

  1. An experimental study on recovery of renal function using {sup 99m}Tc DMSA scintigram after percutaneous nephrostomy in unilateral hydronephrosis

    Energy Technology Data Exchange (ETDEWEB)

    Moon, Tae Yong; Nam, Sang Hwa; Park, Jong Yeon; Kim, Byung Soo [College of Medicine, Pusan National University, Pusan (Korea, Republic of)

    1992-07-15

    Obstruction on the urinary tract eventually results in damage to the kidneys and lose of function. The questions that concern the clinician are the degree of nephron loss in that kidney and potential for recovery following the relief of obstruction. {sup 99m}Tc DMSA accumulates in tubule cells and has been proposed as a marker of the tubular mass. The authors estimated the renal uptake ratio of {sup 99m}Tc DMSA for the degree of nephron loss corresponding to duration of hydronephrosis following left ureteral ligation in 5 New Zealand white rabbits and the potential for recovery following percutaneous nephrostomy of hydronephrosis in 24 rabbits. While the renal uptake ratio of {sup 99m}Tc DMSA of the kidney with unilateral hydronephrosis following ureteral ligation reduced dramatically within 24 hour, that of the opposite healthy kidney increased, and the total renal uptake ratio was same as normal functioning kidneys before ureteral ligation. Upon ureteral release, there was no evidence of definite recovery or impairment in the experimental kidneys for 5 days. The authors conclude that a combination of ureteral release and administration of some drugs such as renal vasodilator or diuretics is an appropriate treatment for the recovery of function in unilateral hydronephrosis.

  2. The Impact of Kidney Development on the Life Course: A Consensus Document for Action

    Science.gov (United States)

    2017-01-01

    Hypertension and chronic kidney disease (CKD) have a significant impact on global morbidity and mortality. The Low Birth Weight and Nephron Number Working Group has prepared a consensus document aimed to address the relatively neglected issue for the developmental programming of hypertension and CKD. It emerged from a workshop held on April 2, 2016, including eminent internationally recognized experts in the field of obstetrics, neonatology, and nephrology. Through multidisciplinary engagement, the goal of the workshop was to highlight the association between fetal and childhood development and an increased risk of adult diseases, focusing on hypertension and CKD, and to suggest possible practical solutions for the future. The recommendations for action of the consensus workshop are the results of combined clinical experience, shared research expertise, and a review of the literature. They highlight the need to act early to prevent CKD and other related noncommunicable diseases later in life by reducing low birth weight, small for gestational age, prematurity, and low nephron numbers at birth through coordinated interventions. Meeting the current unmet needs would help to define the most cost-effective strategies and to optimize interventions to limit or interrupt the developmental programming cycle of CKD later in life, especially in the poorest part of the world. PMID:28319949

  3. Glomerulogenesis: Can it predict the gestational age? A study of 176 fetuses

    Directory of Open Access Journals (Sweden)

    Panduranga Chikkannaiah

    2012-01-01

    Full Text Available Background: Accurate assessment of gestational age of fetuses is essential from both clinical and medico-legal point of view. Crown-rump length, crown-heel length, foot length, and the weight of the fetus are the commonly used parameters for fetal age assessment. However, this estimate often lacks accuracy and sometimes is necessary to combine other data. An analysis of the embryological development of nephrons in the kidney can assist in this determination. Objective : To correlate the gestational age with the histological study of sequential development of nephrons in fetal kidney. Materials and Methods: This study included 176 fetuses delivered between June 2009 and June 2011 and aged from 12 to 40 weeks. The number of glomerular generations counted in hematoxylin and eosin-stained microscopic sections of the kidneys were correlated with the reported period of gestation based on obstetrical methods. Regression analysis was used to determine the statistical significance of the correlation. Results: A high degree of statistically significant correlation was observed between the period of gestation and the number of glomerular generations (P value < 0.0001. Conclusion: The histological assessment of the number of glomerular generations in kidney can be used as a reliable method of estimating fetal age.

  4. Presentation Technique

    International Nuclear Information System (INIS)

    Froejmark, M.

    1992-10-01

    The report presents a wide, easily understandable description of presentation technique and man-machine communication. General fundamentals for the man-machine interface are illustrated, and the factors that affect the interface are described. A model is presented for describing the operators work situation, based on three different levels in the operators behaviour. The operator reacts routinely in the face of simple, known problems, and reacts in accordance with predetermined plans in the face of more complex, recognizable problems. Deep fundamental knowledge is necessary for truly complex questions. Today's technical status and future development have been studied. In the future, the operator interface will be based on standard software. Functions such as zooming, integration of video pictures, and sound reproduction will become common. Video walls may be expected to come into use in situations in which several persons simultaneously need access to the same information. A summary of the fundamental rules for the design of good picture ergonomics and design requirements for control rooms are included in the report. In conclusion, the report describes a presentation technique within the Distribution Automation and Demand Side Management area and analyses the know-how requirements within Vattenfall. If different systems are integrated, such as geographical information systems and operation monitoring systems, strict demands are made on the expertise of the users for achieving a user-friendly technique which is matched to the needs of the human being. (3 figs.)

  5. Higher-order techniques in computational electromagnetics

    CERN Document Server

    Graglia, Roberto D

    2016-01-01

    Higher-Order Techniques in Computational Electromagnetics explains 'high-order' techniques that can significantly improve the accuracy, computational cost, and reliability of computational techniques for high-frequency electromagnetics, such as antennas, microwave devices and radar scattering applications.

  6. Contralateral breast doses measured by film dosimetry: tangential techniques and an optimized IMRT technique

    International Nuclear Information System (INIS)

    Saur, S; Frengen, J; Fjellsboe, L M B; Lindmo, T

    2009-01-01

    The contralateral breast (CLB) doses for three tangential techniques were characterized by using a female thorax phantom and GafChromic EBT film. Dose calculations by the pencil beam and collapsed cone algorithms were included for comparison. The film dosimetry reveals a highly inhomogeneous dose distribution within the CLB, and skin doses due to the medial fields that are several times higher than the interior dose. These phenomena are not correctly reproduced by the calculation algorithms. All tangential techniques were found to give a mean CLB dose of approximately 0.5 Gy. All wedged fields resulted in higher CLB doses than the corresponding open fields, and the lateral open fields resulted in higher CLB doses than the medial open fields. More than a twofold increase in the mean CLB dose from the medial open field was observed for a 90 deg. change of the collimator orientation. Replacing the physical wedge with a virtual wedge reduced the mean dose to the CLB by 35% and 16% for the medial and lateral fields, respectively. Lead shielding reduced the skin dose for a tangential technique by approximately 50%, but the mean CLB dose was only reduced by approximately 11%. Finally, a technique based on open medial fields in combination with several IMRT fields is proposed as a technique for minimizing the CLB dose. With and without lead shielding, the mean CLB dose using this technique was found to be 0.20 and 0.27 Gy, respectively.

  7. The Matador Technique: A technique to improve prostatic ...

    African Journals Online (AJOL)

    A. Pai

    Abstract. The accuracy of brachytherapy seed implantation is reduced by the movement of the prostate when needles are introduced transperineally. This report describes a simple method of introducing the first two needles, which reduces prostate deflection. This technique is analogous to the way a matador uses two ...

  8. MODIFIED TECHNIQUE OF TOTAL LARYNGECTOMY

    Directory of Open Access Journals (Sweden)

    Predrag Spirić

    2010-12-01

    Full Text Available Surgical technique of total laryngectomy is well presented in many surgical textbooks. Essentially, it has remained the same since Gluck an Soerensen in 1922 described all its details. Generally, it stresses the U shape skin incision with releasing laryngeal structures and removing larynx from up to down. Further, pharyngeal reconstruction is performed with different kinds of sutures in two or more layers and is finished with skin suture and suction drainage. One of worst complications following this surgery is pharyngocutaneous fistula (PF. Modifications proposed in this this article suggests vertical skin incision with larynx removal from below upwards. In pharyngeal reconstruction we used the running locked suture in submucosal plan with „tobacco sac“ at the end on the tongue base instead of traditional T shaped suture. Suction drains were not used.The aim of study was to present the modified surgical technique of total laryingectomy and its impact on hospital stay duration and pharyngocutanous fistula formation. In this randomized study we analyzed 49 patients operated with modified surgical technique compared to 49 patient operated with traditional surgical technique of total laryngectomy. The modified technique of total laryngectomy was presented. Using modified technique we managed to decrease the PF percentage from previous 20,41% to acceptable 8,16% (p=0,0334. Also, the average hospital stay was shortened from 14,96 to 10,63 days (t =-2.9850; p=0.0358.The modified technique of total laryngectomy is safe, short and efficient surgical intervention which decreases the number of pharyngocutaneos fistulas and shortens the hospital stay.

  9. A Comparative of business process modelling techniques

    Science.gov (United States)

    Tangkawarow, I. R. H. T.; Waworuntu, J.

    2016-04-01

    In this era, there is a lot of business process modeling techniques. This article is the research about differences of business process modeling techniques. For each technique will explain about the definition and the structure. This paper presents a comparative analysis of some popular business process modelling techniques. The comparative framework is based on 2 criteria: notation and how it works when implemented in Somerleyton Animal Park. Each technique will end with the advantages and disadvantages. The final conclusion will give recommend of business process modeling techniques that easy to use and serve the basis for evaluating further modelling techniques.

  10. Industrial applications of radioisotopes: techniques and procedures of (NTIS) Nuclear Techniques Industrial Service

    International Nuclear Information System (INIS)

    Smith, S.W.; Kruger, J.

    1985-06-01

    Radioisotope handling procedures followed by personnel of the Nuclear Techniques Industrial Service (NTIS) during the conduction of investigations in industry are described. Possible radiological implications as a result of the various measuring techniques and different types of plants are discussed. Conditions under which permanent authorization has been granted for the use of radioisotopes are mentioned

  11. Composite Techniques Based Color Image Compression

    Directory of Open Access Journals (Sweden)

    Zainab Ibrahim Abood

    2017-03-01

    Full Text Available Compression for color image is now necessary for transmission and storage in the data bases since the color gives a pleasing nature and natural for any object, so three composite techniques based color image compression is implemented to achieve image with high compression, no loss in original image, better performance and good image quality. These techniques are composite stationary wavelet technique (S, composite wavelet technique (W and composite multi-wavelet technique (M. For the high energy sub-band of the 3rd level of each composite transform in each composite technique, the compression parameters are calculated. The best composite transform among the 27 types is the three levels of multi-wavelet transform (MMM in M technique which has the highest values of energy (En and compression ratio (CR and least values of bit per pixel (bpp, time (T and rate distortion R(D. Also the values of the compression parameters of the color image are nearly the same as the average values of the compression parameters of the three bands of the same image.

  12. Recent developments in building diagnosis techniques

    CERN Document Server

    2016-01-01

    This book presents a collection of recent research on building diagnosis techniques related to construction pathology, hygrothermal behavior and durability, and diagnostic techniques. It highlights recent advances and new developments in the field of building physics, building anomalies in materials and components, new techniques for improved energy efficiency analysis, and diagnosis techniques such as infrared thermography. This book will be of interest to a wide readership of professionals, scientists, students, practitioners, and lecturers.

  13. Applicability of statistical process control techniques

    NARCIS (Netherlands)

    Schippers, W.A.J.

    1998-01-01

    This paper concerns the application of Process Control Techniques (PCTs) for the improvement of the technical performance of discrete production processes. Successful applications of these techniques, such as Statistical Process Control Techniques (SPC), can be found in the literature. However, some

  14. Glycoprotein and proteoglycan techniques

    International Nuclear Information System (INIS)

    Beeley, J.G.

    1985-01-01

    The aim of this book is to describe techniques which can be used to answer some of the basic questions about glycosylated proteins. Methods are discussed for isolation, compositional analysis, and for determination of the primary structure of carbohydrate units and the nature of protein-carbohydrate linkages of glycoproteins and proteoglycans. High resolution NMR is considered, as well as radioactive labelling techniques. (Auth.)

  15. Laser induced pyrolysis techniques

    International Nuclear Information System (INIS)

    Vanderborgh, N.E.

    1976-01-01

    The application of laser pyrolysis techniques to the problems of chemical analysis is discussed. The processes occurring during laser pyrolysis are first briefly reviewed. The problems encountered in laser pyrolysis gas chromatography are discussed using the analysis of phenanthrene and binary hydrocarbons. The application of this technique to the characterization of naturally occurring carbonaceous material such as oil shales and coal is illustrated

  16. Fundamental study on repairing technique for cracked or damaged parts of structures by cold gas dynamic spray technique

    International Nuclear Information System (INIS)

    Ogawa, Kazuhiro; Amao, Satoshi; Ichikawa, Yuji; Shoji, Tetsuo

    2008-01-01

    This study proposes an innovative technique for repairing of cracked or damaged parts of structures, such as nuclear or thermal power plants, by means of cold gas dynamic spray (CS) technique. In the case of generation of cracks etc. in the structure, the cracks can be repaired by welding. However, the welding spends considerable time on repair, and also needs special skills. The CS technique is known as a new technique not only for coatings but also for thick depositions. It has many advantages, i.e. dense deposition, high deposition rate and low oxidation. Therefore, it has a possibility to apply the CS technique instead of welding to repair the cracks etc. In this study, the cold gas dynamic spray technique as a new repairing technique for some structures is introduced. (author)

  17. Modern recording techniques

    CERN Document Server

    Huber, David Miles

    2013-01-01

    As the most popular and authoritative guide to recording Modern Recording Techniques provides everything you need to master the tools and day to day practice of music recording and production. From room acoustics and running a session to mic placement and designing a studio Modern Recording Techniques will give you a really good grounding in the theory and industry practice. Expanded to include the latest digital audio technology the 7th edition now includes sections on podcasting, new surround sound formats and HD and audio.If you are just starting out or looking for a step up

  18. Surface science techniques

    CERN Document Server

    Walls, JM

    2013-01-01

    This volume provides a comprehensive and up to the minute review of the techniques used to determine the nature and composition of surfaces. Originally published as a special issue of the Pergamon journal Vacuum, it comprises a carefully edited collection of chapters written by specialists in each of the techniques and includes coverage of the electron and ion spectroscopies, as well as the atom-imaging methods such as the atom probe field ion microscope and the scanning tunnelling microscope. Surface science is an important area of study since the outermost surface layers play a crucial role

  19. Single well techniques

    International Nuclear Information System (INIS)

    Drost, W.

    1983-01-01

    The single well technique method includes measurement of parameters of groundwater flow in saturated rock. For determination of filtration velocity the dilution of radioactive tracer is measured, for direction logging the collimeter is rotated in the probe linked with the compass. The limiting factor for measurement of high filtration velocities is the occurrence of turbulent flow. The single well technique is used in civil engineering projects, water works and subsurface drainage of liquid waste from disposal sites. The radioactive tracer method for logging the vertical fluid movement in bore-holes is broadly used in groundwater survey and exploitation. (author)

  20. Craniospinal irradiation techniques

    Energy Technology Data Exchange (ETDEWEB)

    Scarlatescu, Ioana, E-mail: scarlatescuioana@gmail.com; Avram, Calin N. [Faculty of Physics, West University of Timisoara, Bd. V. Parvan 4, 300223 Timisoara (Romania); Virag, Vasile [County Hospital “Gavril Curteanu” - Oradea (Romania)

    2015-12-07

    In this paper we present one treatment plan for irradiation cases which involve a complex technique with multiple beams, using the 3D conformational technique. As the main purpose of radiotherapy is to administrate a precise dose into the tumor volume and protect as much as possible all the healthy tissues around it, for a case diagnosed with a primitive neuro ectoderm tumor, we have developed a new treatment plan, by controlling one of the two adjacent fields used at spinal field, in a way that avoids the fields superposition. Therefore, the risk of overdose is reduced by eliminating the field divergence.

  1. Authentication techniques for smart cards

    International Nuclear Information System (INIS)

    Nelson, R.A.

    1994-02-01

    Smart card systems are most cost efficient when implemented as a distributed system, which is a system without central host interaction or a local database of card numbers for verifying transaction approval. A distributed system, as such, presents special card and user authentication problems. Fortunately, smart cards offer processing capabilities that provide solutions to authentication problems, provided the system is designed with proper data integrity measures. Smart card systems maintain data integrity through a security design that controls data sources and limits data changes. A good security design is usually a result of a system analysis that provides a thorough understanding of the application needs. Once designers understand the application, they may specify authentication techniques that mitigate the risk of system compromise or failure. Current authentication techniques include cryptography, passwords, challenge/response protocols, and biometrics. The security design includes these techniques to help prevent counterfeit cards, unauthorized use, or information compromise. This paper discusses card authentication and user identity techniques that enhance security for microprocessor card systems. It also describes the analysis process used for determining proper authentication techniques for a system

  2. Radio techniques for probing the terrestrial ionosphere.

    Science.gov (United States)

    Hunsucker, R. D.

    The subject of the book is a description of the basic principles of operation, plus the capabilities and limitations of all generic radio techniques employed to investigate the terrestrial ionosphere. The purpose of this book is to present to the reader a balanced treatment of each technique so they can understand how to interpret ionospheric data and decide which techniques are most effective for studying specific phenomena. The first two chapters outline the basic theory underlying the techniques, and each following chapter discusses a separate technique. This monograph is entirely devoted to techniques in aeronomy and space physics. The approach is unique in its presentation of the principles, capabilities and limitations of the most important presently used radio techniques. Typical examples of data are shown for the various techniques, and a brief historical account of the technique development is presented. An extended annotated bibliography of the salient papers in the field is included.

  3. Two sampling techniques for game meat

    OpenAIRE

    van der Merwe, Maretha; Jooste, Piet J.; Hoffman, Louw C.; Calitz, Frikkie J.

    2013-01-01

    A study was conducted to compare the excision sampling technique used by the export market and the sampling technique preferred by European countries, namely the biotrace cattle and swine test. The measuring unit for the excision sampling was grams (g) and square centimetres (cm2) for the swabbing technique. The two techniques were compared after a pilot test was conducted on spiked approved beef carcasses (n = 12) that statistically proved the two measuring units correlated. The two sampling...

  4. A True Open-Loop Synchronization Technique

    DEFF Research Database (Denmark)

    Golestan, Saeed; Vidal, Ana; Yepes, Alejandro G.

    2016-01-01

    Synchronization techniques can be broadly classified into two major categories: Closed-loop and open-loop methods. The open-loop synchronization (OLS) techniques, contrary to the closed-loop ones, are unconditionally stable and benefit from a fast dynamic response. Their performance, however, tends...... is to develop a true OLS (and therefore, unconditionally stable) technique without any need for the calculation of sine and cosine functions. The effectiveness of the proposed synchronization technique is confirmed through the simulation and experimental results....

  5. Technique Selectively Represses Immune System

    Science.gov (United States)

    ... Research Matters December 3, 2012 Technique Selectively Represses Immune System Myelin (green) encases and protects nerve fibers (brown). A new technique prevents the immune system from attacking myelin in a mouse model of ...

  6. Metanephric Adenoma: clinical, imaging, and histological findings

    Energy Technology Data Exchange (ETDEWEB)

    Torricelli, Fabio Cesar Miranda; Marchini, Giovanni Scala, E-mail: fabio_torri@yahoo.com.b [Universidade de Sao Paulo (USP), SP (Brazil). Faculdade de Medicina. Dept. de Urologica; Campos, Rodrigo Sousa Madeira [Hospital do Servidor Publico Estadual, Sao Paulo, SP (Brazil). Dept. de Urologia; Gil, Antonio Otero [Instituto Dante Pazanezzi, Sao Paulo, SP (Brazil)

    2011-07-01

    Metanephric adenoma (MA), also designated nephrogenic nephroma or renal epithelial tumor resembling immature nephron, has just been recently recognized as a special type of benign renal epithelial tumor. Only few reports are found in the literature regarding this rare renal tumor. The purpose of this paper is to describe our clinical, imaging and histological / immunohistochemical observations of MA diagnosed in two patients and compare these data to previous information reported in medical databases (author)

  7. The Utility of 64 Channel Multidetector CT Angiography for Evaluating the Renal Vascular Anatomy and Possible Variations: a Pictorial Essay

    Energy Technology Data Exchange (ETDEWEB)

    Kumar, Sheo; Neyaz, Zafar; Gupta, Archna [Sanjay Gandhi Post Graduate Institute of Medical Sciences, Lucknow (India)

    2010-06-15

    The increased use of laparoscopic nephrectomy and nephron-sparing surgery has prompted the need for a more detailed radiological evaluation of the renal vascular anatomy. Multidetector CT angiography is a fast and accurate modality for assessing the precise anatomy of the renal vessels. In this pictorial review, we present the multidetector CT angiography appearances of the normal renal vascular anatomy and a spectrum of various anomalies that require accurate vascular depiction before undergoing surgical treatment.

  8. The utility of 64 channel multidetector CT angiography for evaluating the renal vascular anatomy and possible variations: a pictorial essay.

    Science.gov (United States)

    Kumar, Sheo; Neyaz, Zafar; Gupta, Archna

    2010-01-01

    The increased use of laparoscopic nephrectomy and nephron-sparing surgery has prompted the need for a more detailed radiological evaluation of the renal vascular anatomy. Multidetector CT angiography is a fast and accurate modality for assessing the precise anatomy of the renal vessels. In this pictorial review, we present the multidetector CT angiography appearances of the normal renal vascular anatomy and a spectrum of various anomalies that require accurate vascular depiction before undergoing surgical treatment.

  9. Glomerular number and function are influenced by spontaneous and induced low birth weight in rats

    DEFF Research Database (Denmark)

    Schreuder, Michiel F; Nyengaard, Jens Randel; Fodor, M

    2005-01-01

    A link exists between low birth weight and diseases in adulthood, such as hypertension, cardiovascular disease, and insulin resistance. Intrauterine growth restriction (IUGR) has been used to explain this association and has been shown to lead to a nephron endowment in humans. A reduction...... is associated with more proteinuria in the long run. Uterine artery ligation in the pregnant rat is a suitable model to study the effects of IUGR on the kidney....

  10. The Utility of 64 Channel Multidetector CT Angiography for Evaluating the Renal Vascular Anatomy and Possible Variations: a Pictorial Essay

    International Nuclear Information System (INIS)

    Kumar, Sheo; Neyaz, Zafar; Gupta, Archna

    2010-01-01

    The increased use of laparoscopic nephrectomy and nephron-sparing surgery has prompted the need for a more detailed radiological evaluation of the renal vascular anatomy. Multidetector CT angiography is a fast and accurate modality for assessing the precise anatomy of the renal vessels. In this pictorial review, we present the multidetector CT angiography appearances of the normal renal vascular anatomy and a spectrum of various anomalies that require accurate vascular depiction before undergoing surgical treatment

  11. Nuclear techniques in analytical chemistry

    CERN Document Server

    Moses, Alfred J; Gordon, L

    1964-01-01

    Nuclear Techniques in Analytical Chemistry discusses highly sensitive nuclear techniques that determine the micro- and macro-amounts or trace elements of materials. With the increasingly frequent demand for the chemical determination of trace amounts of elements in materials, the analytical chemist had to search for more sensitive methods of analysis. This book accustoms analytical chemists with nuclear techniques that possess the desired sensitivity and applicability at trace levels. The topics covered include safe handling of radioactivity; measurement of natural radioactivity; and neutron a

  12. SHOT PUT O’BRIAN TECHNIQUE, EXTENDING THE ANALYSIS OF TECHNIQUE FROM FOUR TO SIX PHASES WITH THE DESCRIPTION

    Directory of Open Access Journals (Sweden)

    Zlatan Saračević

    2011-09-01

    Full Text Available Due to the complexity of the motion, shot put technique is described in phases for easier analysis, easer learning of technique and error correction. It is complete so that in its implementation the transition from phase to phase is not noticed. In aforementioned and described phases of O'Brian spinal shot put technique a large distance, emptiness and disconnection appear between the initial position phase and a phase of overtaking the device, which in the training methods and training technique in primary and secondary education, as well as for students and athletes beginners in shot put represents a major problem regarding connecting, training and technique advancement. Therefore, this work is aimed at facilitating the methods of training of shot put technique, extending from four to six phases, which have been described and include the complete O'Brian technique.

  13. Point-source inversion techniques

    Science.gov (United States)

    Langston, Charles A.; Barker, Jeffrey S.; Pavlin, Gregory B.

    1982-11-01

    A variety of approaches for obtaining source parameters from waveform data using moment-tensor or dislocation point source models have been investigated and applied to long-period body and surface waves from several earthquakes. Generalized inversion techniques have been applied to data for long-period teleseismic body waves to obtain the orientation, time function and depth of the 1978 Thessaloniki, Greece, event, of the 1971 San Fernando event, and of several events associated with the 1963 induced seismicity sequence at Kariba, Africa. The generalized inversion technique and a systematic grid testing technique have also been used to place meaningful constraints on mechanisms determined from very sparse data sets; a single station with high-quality three-component waveform data is often sufficient to discriminate faulting type (e.g., strike-slip, etc.). Sparse data sets for several recent California earthquakes, for a small regional event associated with the Koyna, India, reservoir, and for several events at the Kariba reservoir have been investigated in this way. Although linearized inversion techniques using the moment-tensor model are often robust, even for sparse data sets, there are instances where the simplifying assumption of a single point source is inadequate to model the data successfully. Numerical experiments utilizing synthetic data and actual data for the 1971 San Fernando earthquake graphically demonstrate that severe problems may be encountered if source finiteness effects are ignored. These techniques are generally applicable to on-line processing of high-quality digital data, but source complexity and inadequacy of the assumed Green's functions are major problems which are yet to be fully addressed.

  14. Nuclear techniques in agriculture

    International Nuclear Information System (INIS)

    Bhagwat, S.G.

    2012-01-01

    Crops provide us food grains and many other products. Demand for food and other agricultural products is increasing. There is also need for improvement of quality of the agricultural produce. There are several technologies in use for achieving the goal of increasing the quantity and quality of agricultural produce. Nuclear techniques provide us with an option which has certain advantages. The characteristics of crop plants are determined by the genetic make up of the plant. Traditionally the genetic make up was modified using conventional breeding techniques such as cross breeding to improve crops for yield, disease resistance, stress tolerance, resistance to insect pests or to improve quality. New varieties of crops are produced which replace the earlier ones and thus the demands are met. The process of development of new varieties is long and time consuming. Nuclear technique called mutation breeding provides an efficient way of breeding new varieties or improving the older ones. This technique merely enhances the process of occurrence of mutations. In nature mutations occur at a rate of approximately one in a million, while when mutations are induced using radiations such as gamma rays the efficiency of inducing mutations is enhanced. Useful mutations are selected, the mutants are evaluated and developed as a new variety. In the Nuclear Agriculture and Biotechnology Division (NA and BTD) this technique has been used to develop mutants of many crop plants. The mutants can be used to develop a variety directly or by using it in further breeding programme. Using these approaches the NA and BTD has developed 40 new varieties of crops such as groundnut, mungbean, urid, pigeon pea, mustard, soybean, sunflower, cowpea, jute. These varieties are developed in collaboration with other agricultural institutions and are popular among the farming community. The method of mutation breeding can be applied to many other crops for improvement. There is increasing interest among

  15. Novel food processing techniques

    Directory of Open Access Journals (Sweden)

    Vesna Lelas

    2006-12-01

    Full Text Available Recently, a lot of investigations have been focused on development of the novel mild food processing techniques with the aim to obtain the high quality food products. It is presumed also that they could substitute some of the traditional processes in the food industry. The investigations are primarily directed to usage of high hydrostatic pressure, ultrasound, tribomechanical micronization, microwaves, pulsed electrical fields. The results of the scientific researches refer to the fact that application of some of these processes in particular food industry can result in lots of benefits. A significant energy savings, shortening of process duration, mild thermal conditions, food products with better sensory characteristics and with higher nutritional values can be achieved. As some of these techniques act also on the molecular level changing the conformation, structure and electrical potential of organic as well as inorganic materials, the improvement of some functional properties of these components may occur. Common characteristics of all of these techniques are treatment at ambient or insignificant higher temperatures and short time of processing (1 to 10 minutes. High hydrostatic pressure applied to various foodstuffs can destroy some microorganisms, successfully modify molecule conformation and consequently improve functional properties of foods. At the same time it acts positively on the food products intend for freezing. Tribomechanical treatment causes micronization of various solid materials that results in nanoparticles and changes in structure and electrical potential of molecules. Therefore, the significant improvement of some rheological and functional properties of materials occurred. Ultrasound treatment proved to be potentially very successful technique of food processing. It can be used as a pretreatment to drying (decreases drying time and improves functional properties of food, as extraction process of various components

  16. Efficacy of the World Health Organization-recommended handwashing technique and a modified washing technique to remove Clostridium difficile from hands.

    Science.gov (United States)

    Deschênes, Philippe; Chano, Frédéric; Dionne, Léa-Laurence; Pittet, Didier; Longtin, Yves

    2017-08-01

    The efficacy of the World Health Organization (WHO)-recommended handwashing technique against Clostridium difficile is uncertain, and whether it could be improved remains unknown. Also, the benefit of using a structured technique instead of an unstructured technique remains unclear. This study was a prospective comparison of 3 techniques (unstructured, WHO, and a novel technique dubbed WHO shortened repeated [WHO-SR] technique) to remove C difficile. Ten participants were enrolled and performed each technique. Hands were contaminated with 3 × 10 6 colony forming units (CFU) of a nontoxigenic strain containing 90% spores. Efficacy was assessed using the whole-hand method. The relative efficacy of each technique and of a structured (either WHO or WHO-SR) vs an unstructured technique were assessed by Mann-Whitney U test and Wilcoxon signed-rank test. The median effectiveness of the unstructured, WHO, and WHO-SR techniques in log 10 CFU reduction was 1.30 (interquartile range [IQR], 1.27-1.43), 1.71 (IQR, 1.34-1.91), and 1.70 (IQR, 1.54-2.42), respectively. The WHO-SR technique was significantly more efficacious than the unstructured technique (P = .01). Washing hands with a structured technique was more effective than washing with an unstructured technique (median, 1.70 vs 1.30 log 10 CFU reduction, respectively; P = .007). A structured washing technique is more effective than an unstructured technique against C difficile. Copyright © 2017 Association for Professionals in Infection Control and Epidemiology, Inc. Published by Elsevier Inc. All rights reserved.

  17. A review on creatinine measurement techniques.

    Science.gov (United States)

    Mohabbati-Kalejahi, Elham; Azimirad, Vahid; Bahrami, Manouchehr; Ganbari, Ahmad

    2012-08-15

    This paper reviews the entire recent global tendency for creatinine measurement. Creatinine biosensors involve complex relationships between biology and micro-mechatronics to which the blood is subjected. Comparison between new and old methods shows that new techniques (e.g. Molecular Imprinted Polymers based algorithms) are better than old methods (e.g. Elisa) in terms of stability and linear range. All methods and their details for serum, plasma, urine and blood samples are surveyed. They are categorized into five main algorithms: optical, electrochemical, impedometrical, Ion Selective Field-Effect Transistor (ISFET) based technique and chromatography. Response time, detection limit, linear range and selectivity of reported sensors are discussed. Potentiometric measurement technique has the lowest response time of 4-10 s and the lowest detection limit of 0.28 nmol L(-1) belongs to chromatographic technique. Comparison between various techniques of measurements indicates that the best selectivity belongs to MIP based and chromatographic techniques. Copyright © 2012 Elsevier B.V. All rights reserved.

  18. Statistical Techniques for Project Control

    CERN Document Server

    Badiru, Adedeji B

    2012-01-01

    A project can be simple or complex. In each case, proven project management processes must be followed. In all cases of project management implementation, control must be exercised in order to assure that project objectives are achieved. Statistical Techniques for Project Control seamlessly integrates qualitative and quantitative tools and techniques for project control. It fills the void that exists in the application of statistical techniques to project control. The book begins by defining the fundamentals of project management then explores how to temper quantitative analysis with qualitati

  19. Scalable Techniques for Formal Verification

    CERN Document Server

    Ray, Sandip

    2010-01-01

    This book presents state-of-the-art approaches to formal verification techniques to seamlessly integrate different formal verification methods within a single logical foundation. It should benefit researchers and practitioners looking to get a broad overview of the spectrum of formal verification techniques, as well as approaches to combining such techniques within a single framework. Coverage includes a range of case studies showing how such combination is fruitful in developing a scalable verification methodology for industrial designs. This book outlines both theoretical and practical issue

  20. Artificial intelligence techniques in Prolog

    CERN Document Server

    Shoham, Yoav

    1993-01-01

    Artificial Intelligence Techniques in Prolog introduces the reader to the use of well-established algorithmic techniques in the field of artificial intelligence (AI), with Prolog as the implementation language. The techniques considered cover general areas such as search, rule-based systems, and truth maintenance, as well as constraint satisfaction and uncertainty management. Specific application domains such as temporal reasoning, machine learning, and natural language are also discussed.Comprised of 10 chapters, this book begins with an overview of Prolog, paying particular attention to Prol

  1. Use of communication techniques by Maryland dentists.

    Science.gov (United States)

    Maybury, Catherine; Horowitz, Alice M; Wang, Min Qi; Kleinman, Dushanka V

    2013-12-01

    Health care providers' use of recommended communication techniques can increase patients' adherence to prevention and treatment regimens and improve patient health outcomes. The authors conducted a survey of Maryland dentists to determine the number and type of communication techniques they use on a routine basis. The authors mailed a 30-item questionnaire to a random sample of 1,393 general practice dentists and all 169 members of the Maryland chapter of the American Academy of Pediatric Dentistry. The overall response rate was 38.4 percent. Analysis included descriptive statistics, analysis of variance and ordinary least squares regression analysis to examine the association of dentists' characteristics with the number of communication techniques used. They set the significance level at P communication techniques and 3.6 of the seven basic techniques, whereas pediatric dentists reported using a mean of 8.4 and 3.8 of those techniques, respectively. General dentists who had taken a communication course outside of dental school were more likely than those who had not to use the 18 techniques (P communication course outside of dental school were more likely than those who had not to use the 18 techniques (P communication techniques that dentists used routinely varied across the 18 techniques and was low for most techniques. Practical Implications. Professional education is needed both in dental school curricula and continuing education courses to increase use of recommended communication techniques. Specifically, dentists and their team members should consider taking communication skills courses and conducting an overall evaluation of their practices for user friendliness.

  2. New diagnostic technique for Zeeman-compensated atomic beam slowing: technique and results

    OpenAIRE

    Molenaar, P.A.; Straten, P. van der; Heideman, H.G.M.; Metcalf, H.

    1997-01-01

    We have developed a new diagnostic tool for the study of Zeeman-compensated slowing of an alkali atomic beam. Our time-of-flight technique measures the longitudinal veloc- ity distribution of the slowed atoms with a resolution below the Doppler limit of 30 cm/s. Furthermore, it can map the position and velocity distribution of atoms in either ground hyperfine level inside the solenoid without any devices inside the solenoid. The technique reveals the optical pumping ef- fects, and shows in de...

  3. A Study on Nondestructive Technique Using Laser Technique for Evaluation of Carbon fiber Reinforced Plastic

    International Nuclear Information System (INIS)

    Choi, Sang Woo; Lee, Joon Hyun; Seo, Kyeong Cheol; Byun, Joon Hyung

    2005-01-01

    Fiber reinforced plastic material should be inspected in fabrication process in order to enhance quality by prevent defects such as delamination and void. Generally, ultrasonic technique is widely used to evaluate FRP. In conventional ultrasonic techniques, transducer should be contacted on FRP. However, conventional contacting method could not be applied in fabrication process and novel non-contact evaluating technique was required. Laser-based ultrasonic technique was tried to evaluate CFRP plate. Laser-based ultrasonic waves propagated on CFRP were received with various transducers such as accelerometer and AE sensor in order to evaluate the properties of waves due to the variation of frequency. Velocities of laser-based ultrasonic waves were evaluated for various fiber orientation. In addition, laser interferometry was used to receive ultrasonic wave in CFRP and frequency was analysed

  4. The Delphi technique in radiography education research

    International Nuclear Information System (INIS)

    John-Matthews, J.St.; Wallace, M.J.; Robinson, L.

    2017-01-01

    Objectives: To describe and review the Delphi technique as a tool for radiographers engaged in mixed-methods research whereby agreement is required on the proficiencies needed by educational programmes for pre- and post- registration radiographers. This is achieved through a description offering a brief history of the technique. Through a literature search, radiography education research using this technique is identified. A protocol for a research project using the technique is presented. Using this worked example, advantages and disadvantages of the method are explored including sampling of participants, sample size, number of rounds and methods of feedback. Key findings: There are limited examples of the use of the Delphi technique in radiography literature including considerations on how to select experts and panel size. Conclusion: The Delphi technique is a suitable method for establishing collective agreement in the design of radiography educational interventions. Additional research is needed to deepen this evidence-based knowledge. - Highlights: • The Delphi Technique is used to gain collective agreement in forecasting healthcare education priorities. • There is increase of the use of the technique in healthcare education literature. • There are some examples of the technique in radiography education research. • A worked example of this technique is provided to critically evaluate this tool.

  5. Stargate: Energy Management Techniques

    OpenAIRE

    Vijay Raghunathan; Mani Srivastava; Trevor Pering; Roy Want

    2004-01-01

    This poster presents techniques for energy efficient operation of the Stargate wireless platform. In addition to conventional power management techniques such as dynamic voltage and scaling and processor shutdown, the Stargate features several mechanisms for energy efficient operation of the communication subsystem, such as support for hierarchical radios, Bluetooth based remote wakeup, mote based wakeup, etc. Finally, design optimizations including the use of power gating, and provision for ...

  6. Modern techniques of surface science

    CERN Document Server

    Woodruff, D Phil

    2016-01-01

    This fully revised, updated and reorganised third edition provides a thorough introduction to the characterisation techniques used in surface science and nanoscience today. Each chapter brings together and compares the different techniques used to address a particular research question, including how to determine the surface composition, surface structure, surface electronic structure, surface microstructure at different length scales (down to sub-molecular), and the molecular character of adsorbates and their adsorption or reaction properties. Readers will easily understand the relative strengths and limitations of the techniques available to them and, ultimately, will be able to select the most suitable techniques for their own particular research purposes. This is an essential resource for researchers and practitioners performing materials analysis, and for senior undergraduate students looking to gain a clear understanding of the underlying principles and applications of the different characterisation tec...

  7. Radiation technique for the destruction of plutella

    International Nuclear Information System (INIS)

    1980-01-01

    Plutella can be destroyed by cultivation technique where cabbage is grown interchangebly with other plants, biological technique where the natural enemy of plutella is used, and chemical technique where insecticide is used. Those method do not better results than the sterile male technique which can be either nuclear or chemical in nature. Laboratory, semifield research, and research in a limited field have been carried out when applying the sterile male technique. (SMN)

  8. Experimental techniques; Techniques experimentales

    Energy Technology Data Exchange (ETDEWEB)

    Roussel-Chomaz, P. [GANIL CNRS/IN2P3, CEA/DSM, 14 - Caen (France)

    2007-07-01

    This lecture presents the experimental techniques, developed in the last 10 or 15 years, in order to perform a new class of experiments with exotic nuclei, where the reactions induced by these nuclei allow to get information on their structure. A brief review of the secondary beams production methods will be given, with some examples of facilities in operation or under project. The important developments performed recently on cryogenic targets will be presented. The different detection systems will be reviewed, both the beam detectors before the targets, and the many kind of detectors necessary to detect all outgoing particles after the reaction: magnetic spectrometer for the heavy fragment, detection systems for the target recoil nucleus, {gamma} detectors. Finally, several typical examples of experiments will be detailed, in order to illustrate the use of each detector either alone, or in coincidence with others. (author)

  9. Food physics and radiation techniques

    International Nuclear Information System (INIS)

    Szabo, A. S.

    1999-01-01

    In the lecture information is given about food physics, which is a rather new, interdisciplinary field of science, connecting food science and applied physics. The topics of radioactivity of foodstuffs and radiation techniques in the food industry are important parts of food physics detailed information will be given about the main fields (e.g. radio stimulation, food preservation) of radiation techniques in the agro-food sector. Finally some special questions of radioactive contamination of foodstuffs in hungary and applicability of radioanalytical techniques (e.g. Inaa) for food investigation will be analyzed and discussed

  10. A simplified indirect bonding technique

    Directory of Open Access Journals (Sweden)

    Radha Katiyar

    2014-01-01

    Full Text Available With the advent of lingual orthodontics, indirect bonding technique has become an integral part of practice. It involves placement of brackets initially on the models and then their transfer to teeth with the help of transfer trays. Problems encountered with current indirect bonding techniques used are (1 the possibility of adhesive flash remaining around the base of the brackets which requires removal (2 longer time required for the adhesive to gain enough bond strength for secure tray removal. The new simplified indirect bonding technique presented here overcomes both these problems.

  11. Imaging Techniques in Endodontics: An Overview

    Science.gov (United States)

    Deepak, B. S.; Subash, T. S.; Narmatha, V. J.; Anamika, T.; Snehil, T. K.; Nandini, D. B.

    2012-01-01

    This review provides an overview of the relevance of imaging techniques such as, computed tomography, cone beam computed tomography, and ultrasound, to endodontic practice. Many limitations of the conventional radiographic techniques have been overcome by the newer methods. Advantages and disadvantages of various imaging techniques in endodontic practice are also discussed. PMID:22530184

  12. Motion Transplantation Techniques: A Survey

    NARCIS (Netherlands)

    van Basten, Ben; Egges, Arjan

    2012-01-01

    During the past decade, researchers have developed several techniques for transplanting motions. These techniques transplant a partial auxiliary motion, possibly defined for a small set of degrees of freedom, on a base motion. Motion transplantation improves motion databases' expressiveness and

  13. Tendon 'turnover lengthening' technique.

    Science.gov (United States)

    Cerovac, S; Miranda, B H

    2013-11-01

    Tendon defect reconstruction is amongst the most technically challenging areas in hand surgery. Tendon substance deficiency reconstruction techniques include lengthening, grafting, two-stage reconstruction and tendon transfers, however each is associated with unique challenges over and above direct repair. We describe a novel 'turnover lengthening' technique for hand tendons that has successfully been applied to the repair of several cases, including a case of attritional flexor and traumatic extensor tendon rupture in two presented patients where primary tenorrhaphy was not possible. In both cases a good post-operative outcome was achieved, as the patients were happy having returned back to normal activities of daily living such that they were discharged 12 weeks post-operatively. Our technique avoids the additional morbidity and complications associated with grafting, transfers and two stage reconstructions. It is quick, simple and reproducible for defects not exceeding 3-4 cm, provides a means of immediate one stage reconstruction, no secondary donor site morbidity and does not compromise salvage by tendon transfer and/or two-stage reconstruction in cases of failure. To our knowledge no such technique has been previously been described to reconstruct such hand tendon defects. Crown Copyright © 2013. Published by Elsevier Ltd. All rights reserved.

  14. The attribute measurement technique

    International Nuclear Information System (INIS)

    MacArthur, Duncan W.; Langner, Diana; Smith, Morag; Thron, Jonathan; Razinkov, Sergey; Livke, Alexander

    2010-01-01

    Any verification measurement performed on potentially classified nuclear material must satisfy two seemingly contradictory constraints. First and foremost, no classified information can be released. At the same time, the monitoring party must have confidence in the veracity of the measurement. An information barrier (IB) is included in the measurement system to protect the potentially classified information while allowing sufficient information transfer to occur for the monitoring party to gain confidence that the material being measured is consistent with the host's declarations, concerning that material. The attribute measurement technique incorporates an IB and addresses both concerns by measuring several attributes of the nuclear material and displaying unclassified results through green (indicating that the material does possess the specified attribute) and red (indicating that the material does not possess the specified attribute) lights. The attribute measurement technique has been implemented in the AVNG, an attribute measuring system described in other presentations at this conference. In this presentation, we will discuss four techniques used in the AVNG: (1) the 1B, (2) the attribute measurement technique, (3) the use of open and secure modes to increase confidence in the displayed results, and (4) the joint design as a method for addressing both host and monitor needs.

  15. Practical techniques for pediatric computed tomography

    International Nuclear Information System (INIS)

    Fitz, C.R.; Harwood-Nash, D.C.; Kirks, D.R.; Kaufman, R.A.; Berger, P.E.; Kuhn, J.P.; Siegel, M.J.

    1983-01-01

    Dr. Donald Kirks has assembled this section on Practical Techniques for Pediatric Computed Tomography. The material is based on a presentation in the Special Interest session at the 25th Annual Meeting of the Society for Pediatric Radiology in New Orleans, Louisiana, USA in 1982. Meticulous attention to detail and technique is required to ensure an optimal CT examination. CT techniques specifically applicable to infants and children have not been disseminated in the radiology literature and in this respect it may rightly be observed that ''the child is not a small adult''. What follows is a ''cookbook'' prepared by seven participants and it is printed in Pediatric Radiology, in outline form, as a statement of individual preferences for pediatric CT techniques. This outline gives concise explanation of techniques and permits prompt dissemination of information. (orig.)

  16. Advanced sensing techniques for cognitive radio

    CERN Document Server

    Zhao, Guodong; Li, Shaoqian

    2017-01-01

    This SpringerBrief investigates advanced sensing techniques to detect and estimate the primary receiver for cognitive radio systems. Along with a comprehensive overview of existing spectrum sensing techniques, this brief focuses on the design of new signal processing techniques, including the region-based sensing, jamming-based probing, and relay-based probing. The proposed sensing techniques aim to detect the nearby primary receiver and estimate the cross-channel gain between the cognitive transmitter and primary receiver. The performance of the proposed algorithms is evaluated by simulations in terms of several performance parameters, including detection probability, interference probability, and estimation error. The results show that the proposed sensing techniques can effectively sense the primary receiver and improve the cognitive transmission throughput. Researchers and postgraduate students in electrical engineering will find this an exceptional resource.

  17. Estimating individual glomerular volume in the human kidney: clinical perspectives.

    Science.gov (United States)

    Puelles, Victor G; Zimanyi, Monika A; Samuel, Terence; Hughson, Michael D; Douglas-Denton, Rebecca N; Bertram, John F; Armitage, James A

    2012-05-01

    Measurement of individual glomerular volumes (IGV) has allowed the identification of drivers of glomerular hypertrophy in subjects without overt renal pathology. This study aims to highlight the relevance of IGV measurements with possible clinical implications and determine how many profiles must be measured in order to achieve stable size distribution estimates. We re-analysed 2250 IGV estimates obtained using the disector/Cavalieri method in 41 African and 34 Caucasian Americans. Pooled IGV analysis of mean and variance was conducted. Monte-Carlo (Jackknife) simulations determined the effect of the number of sampled glomeruli on mean IGV. Lin's concordance coefficient (R(C)), coefficient of variation (CV) and coefficient of error (CE) measured reliability. IGV mean and variance increased with overweight and hypertensive status. Superficial glomeruli were significantly smaller than juxtamedullary glomeruli in all subjects (P IGV mean and variability. Overall, mean IGV was particularly reliable with nine or more sampled glomeruli (R(C) > 0.95, IGV and estimated total glomerular number. Multiple comorbidities for CKD are associated with increased IGV mean and variance within subjects, including overweight, obesity and hypertension. Zonal selection and the number of sampled glomeruli do not represent drawbacks for future longitudinal biopsy-based studies of glomerular size and distribution.

  18. The Technique of Special-Effects Cinematography.

    Science.gov (United States)

    Fielding, Raymond

    The author describes the many techniques used to produce cinematic effects that would be too costly, too difficult, too time-consuming, too dangerous, or simply impossible to achieve with conventional photographic techniques. He points out that these techniques are available not only for 35 millimeter work but also to the 16 mm. photographer who…

  19. Neutron techniques

    International Nuclear Information System (INIS)

    Charlton, J.S.

    1986-01-01

    The way in which neutrons interact with matter such as slowing-down, diffusion, neutron absorption and moderation are described. The use of neutron techniques in industry, in moisture gages, level and interface measurements, the detection of blockages, boron analysis in ore feedstock and industrial radiography are discussed. (author)

  20. Applying contemporary statistical techniques

    CERN Document Server

    Wilcox, Rand R

    2003-01-01

    Applying Contemporary Statistical Techniques explains why traditional statistical methods are often inadequate or outdated when applied to modern problems. Wilcox demonstrates how new and more powerful techniques address these problems far more effectively, making these modern robust methods understandable, practical, and easily accessible.* Assumes no previous training in statistics * Explains how and why modern statistical methods provide more accurate results than conventional methods* Covers the latest developments on multiple comparisons * Includes recent advanc

  1. Materials characterization techniques

    National Research Council Canada - National Science Library

    Zhang, Sam; Li, L; Kumar, Ashok

    2009-01-01

    "With an emphasis on practical applications and real-world case studies, Materials Characterization Techniques presents the principles of widely used advanced surface and structural characterization...

  2. A disposition of interpolation techniques

    NARCIS (Netherlands)

    Knotters, M.; Heuvelink, G.B.M.

    2010-01-01

    A large collection of interpolation techniques is available for application in environmental research. To help environmental scientists in choosing an appropriate technique a disposition is made, based on 1) applicability in space, time and space-time, 2) quantification of accuracy of interpolated

  3. Comparison of marginal accuracy of castings fabricated by conventional casting technique and accelerated casting technique: an in vitro study.

    Science.gov (United States)

    Reddy, S Srikanth; Revathi, Kakkirala; Reddy, S Kranthikumar

    2013-01-01

    Conventional casting technique is time consuming when compared to accelerated casting technique. In this study, marginal accuracy of castings fabricated using accelerated and conventional casting technique was compared. 20 wax patterns were fabricated and the marginal discrepancy between the die and patterns were measured using Optical stereomicroscope. Ten wax patterns were used for Conventional casting and the rest for Accelerated casting. A Nickel-Chromium alloy was used for the casting. The castings were measured for marginal discrepancies and compared. Castings fabricated using Conventional casting technique showed less vertical marginal discrepancy than the castings fabricated by Accelerated casting technique. The values were statistically highly significant. Conventional casting technique produced better marginal accuracy when compared to Accelerated casting. The vertical marginal discrepancy produced by the Accelerated casting technique was well within the maximum clinical tolerance limits. Accelerated casting technique can be used to save lab time to fabricate clinical crowns with acceptable vertical marginal discrepancy.

  4. Radiotracer techniques in hydrological studies

    International Nuclear Information System (INIS)

    Oladipo, M.O.A.; Funtua, I.I.

    2000-07-01

    The use of radioactive tracers particularly short-lived radioisotopes frequently offers advantages over conventional methods of analyses. Applications of nuclear techniques in the field of hydrology constitute important and sometimes unique tools for obtaining critical information needed for water resources management. Essentially, radiotracer techniques offer a safe, cost effective and powerful tool in the assessment, management and protection of water resources. The Centre for Energy Research and Training, Ahmadu Bello University, Zaria of late has been offering consultancy services to some industries in the area of radiotracer technique. The first nuclear reactor in Nigeria, the MNSR, is expected to be commissioned in the Centre very soon. Many short-lived radioisotopes such as Cu-64, Ga-72, Br-82, Hg-197 etc which are very important in hydrological studies can be produced by the MNSR facility. This article reports on the basic principles of the technique and its roles in hydrology

  5. Research in decommissioning techniques for nuclear fuel cycle facilities in JNC. 7. JWTF decommissioning techniques

    International Nuclear Information System (INIS)

    Ogawa, Ryuichiro; Ishijima, Noboru

    1999-02-01

    Decommissioning techniques such as radiation measuring and monitoring, decontamination, dismantling and remote handling in the world were surveyed to upgrading technical know-how database for decommissioning of Joyo Waste Treatment Facility (JWTF). As the result, five literatures for measuring and monitoring techniques, 14 for decontamination and 22 for dismantling feasible for JWTF decommissioning were obtained and were summarized in tables. On the basis of the research, practical applicability of those techniques to decommissioning of JWTF was evaluated. This report contains brief surveyed summaries related to JWTF decommissioning. (H. Itami)

  6. Weighted hybrid technique for recommender system

    Science.gov (United States)

    Suriati, S.; Dwiastuti, Meisyarah; Tulus, T.

    2017-12-01

    Recommender system becomes very popular and has important role in an information system or webpages nowadays. A recommender system tries to make a prediction of which item a user may like based on his activity on the system. There are some familiar techniques to build a recommender system, such as content-based filtering and collaborative filtering. Content-based filtering does not involve opinions from human to make the prediction, while collaborative filtering does, so collaborative filtering can predict more accurately. However, collaborative filtering cannot give prediction to items which have never been rated by any user. In order to cover the drawbacks of each approach with the advantages of other approach, both approaches can be combined with an approach known as hybrid technique. Hybrid technique used in this work is weighted technique in which the prediction score is combination linear of scores gained by techniques that are combined.The purpose of this work is to show how an approach of weighted hybrid technique combining content-based filtering and item-based collaborative filtering can work in a movie recommender system and to show the performance comparison when both approachare combined and when each approach works alone. There are three experiments done in this work, combining both techniques with different parameters. The result shows that the weighted hybrid technique that is done in this work does not really boost the performance up, but it helps to give prediction score for unrated movies that are impossible to be recommended by only using collaborative filtering.

  7. Twin - Arch technique. Revival of the "edgewise -Technique"?

    Directory of Open Access Journals (Sweden)

    Jacob Karp

    2012-01-01

    The SNB – Bracket brings a new dimension into the orthodontic world which is most apparent in extraction cases. Its Teflon – like material has a very low friction coefficient thus, reducing the treatment time considerably. Through the use of low dimensioned arch wires, the Twin – Arch Technique becomes a Light – wire system and simultaneously provides good anchorage and torque control.

  8. Spray deposition using impulse atomization technique

    International Nuclear Information System (INIS)

    Ellendt, N.; Schmidt, R.; Knabe, J.; Henein, H.; Uhlenwinkel, V.

    2004-01-01

    A novel technique, impulse atomization, has been used for spray deposition. This single fluid atomization technique leads to different spray characteristics and impact conditions of the droplets compared to gas atomization technique which is the common technique used for spray deposition. Deposition experiments with a Cu-6Sn alloy were conducted to evaluate the appropriateness of impulse atomization to produce dense material. Based on these experiments, a model has been developed to simulate the thermal history and the local solidification rates of the deposited material. A numerical study shows how different cooling conditions affect the solidification rate of the material

  9. Invasive and noninvasive dental analgesia techniques.

    Science.gov (United States)

    Estafan, D J

    1998-01-01

    Although needle-administered local anesthesia has been an essential tool of modern dentistry, it has also been responsible for many patients' fears of dental visits. Several new techniques have recently evolved that may offer viable alternatives. Two of these operate via electronic mechanisms that interfere with pain signals, two others involve transmucosal modes of administration, and a fifth technique involves an intraosseous pathway for anesthesia administration. Each of these techniques has different indications for dental procedures, but none is intended to replace needle administration in dentistry. This overview highlights the salient features of these alternative dental anesthesia techniques.

  10. Physical simulations using centrifuge techniques

    International Nuclear Information System (INIS)

    Sutherland, H.J.

    1981-01-01

    Centrifuge techniques offer a technique for doing physical simulations of the long-term mechanical response of deep ocean sediment to the emplacement of waste canisters and to the temperature gradients generated by them. Preliminary investigations of the scaling laws for pertinent phenomena indicate that the time scaling will be consistent among them and equal to the scaling factor squared. This result implies that this technique will permit accelerated-life-testing of proposed configurations; i.e, long-term studies may be done in relatively short times. Presently, existing centrifuges are being modified to permit scale model testing. This testing will start next year

  11. LANDING TECHNIQUES IN BEACH VOLLEYBALL

    Directory of Open Access Journals (Sweden)

    Markus Tilp

    2013-09-01

    Full Text Available The aims of the present study were to establish a detailed and representative record of landing techniques (two-, left-, and right-footed landings in professional beach volleyball and compare the data with those of indoor volleyball. Beach volleyball data was retrieved from videos taken at FIVB World Tour tournaments. Landing techniques were compared in the different beach and indoor volleyball skills serve, set, attack, and block with regard to sex, playing technique, and court position. Significant differences were observed between men and women in landings following block actions (χ²(2 = 18.19, p < 0.01 but not following serve, set, and attack actions. Following blocking, men landed more often on one foot than women. Further differences in landings following serve and attack with regard to playing technique and position were mainly observed in men. The comparison with landing techniques in indoor volleyball revealed overall differences both in men (χ²(2 = 161.4, p < 0.01 and women (χ²(2 = 84.91, p < 0.01. Beach volleyball players land more often on both feet than indoor volleyball players. Besides the softer surface in beach volleyball, and therefore resulting lower loads, these results might be another reason for fewer injuries and overuse conditions compared to indoor volleyball

  12. Landing Techniques in Beach Volleyball

    Science.gov (United States)

    Tilp, Markus; Rindler, Michael

    2013-01-01

    The aims of the present study were to establish a detailed and representative record of landing techniques (two-, left-, and right-footed landings) in professional beach volleyball and compare the data with those of indoor volleyball. Beach volleyball data was retrieved from videos taken at FIVB World Tour tournaments. Landing techniques were compared in the different beach and indoor volleyball skills serve, set, attack, and block with regard to sex, playing technique, and court position. Significant differences were observed between men and women in landings following block actions (χ2(2) = 18.19, p volleyball revealed overall differences both in men (χ2(2) = 161.4, p volleyball players land more often on both feet than indoor volleyball players. Besides the softer surface in beach volleyball, and therefore resulting lower loads, these results might be another reason for fewer injuries and overuse conditions compared to indoor volleyball. Key Points About 1/3 of all jumping actions in beach volleyball result in a landing on one foot. Especially following block situations men land on one foot more often than women. Landing techniques are related to different techniques and positions. Landings on one foot are less common in beach volleyball than indoor volleyball. This could be a reason for fewer injuries and overuse conditions. PMID:24149150

  13. 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

  14. Biopsy techniques for intraocular tumors

    Directory of Open Access Journals (Sweden)

    Pukhraj Rishi

    2016-01-01

    Full Text Available Biopsy involves the surgical removal of a tissue specimen for histopathologic evaluation. Most intraocular tumors are reliably diagnosed based on the clinical evaluation or with noninvasive diagnostic techniques. However, accurately diagnosing a small percentage of tumors can be challenging. A tissue biopsy is thus needed to establish a definitive diagnosis and plan the requisite treatment. From fine-needle aspiration biopsy (FNAB to surgical excision, all tissue collection techniques have been studied in the literature. Each technique has its indications and limitations. FNAB has been reported to provide for 88-95% reliable and safe ophthalmic tumor diagnosis and has gained popularity for prognostic purposes and providing eye conserving treatment surgeries. The technique and instrumentation for biopsy vary depending upon the tissue involved (retina, choroid, subretinal space, vitreous, and aqueous, suspected diagnosis, size, location, associated retinal detachment, and clarity of the media. The cytopathologist confers a very important role in diagnosis and their assistance plays a key role in managing and planning the treatment for malignancies.

  15. Submucosal tunneling techniques: current perspectives.

    Science.gov (United States)

    Kobara, Hideki; Mori, Hirohito; Rafiq, Kazi; Fujihara, Shintaro; Nishiyama, Noriko; Ayaki, Maki; Yachida, Tatsuo; Matsunaga, Tae; Tani, Johji; Miyoshi, Hisaaki; Yoneyama, Hirohito; Morishita, Asahiro; Oryu, Makoto; Iwama, Hisakazu; Masaki, Tsutomu

    2014-01-01

    Advances in endoscopic submucosal dissection include a submucosal tunneling technique, involving the introduction of tunnels into the submucosa. These tunnels permit safer offset entry into the peritoneal cavity for natural orifice transluminal endoscopic surgery. Technical advantages include the visual identification of the layers of the gut, blood vessels, and subepithelial tumors. The creation of a mucosal flap that minimizes air and fluid leakage into the extraluminal cavity can enhance the safety and efficacy of surgery. This submucosal tunneling technique was adapted for esophageal myotomy, culminating in its application to patients with achalasia. This method, known as per oral endoscopic myotomy, has opened up the new discipline of submucosal endoscopic surgery. Other clinical applications of the submucosal tunneling technique include its use in the removal of gastrointestinal subepithelial tumors and endomicroscopy for the diagnosis of functional and motility disorders. This review suggests that the submucosal tunneling technique, involving a mucosal safety flap, can have potential values for future endoscopic developments.

  16. Lightweight Cryptographic Techniques

    National Research Council Canada - National Science Library

    Yuen, Horace

    2004-01-01

    The objective of this project was to develop new cryptographic techniques, and to modify the important existing ones, for applications to encryption and authentication in energy-constrained sensors...

  17. The ``hydro-wired``: more than a technique, a global concept; ``L`hydrocable``: plus qu`une technique, un concept global

    Energy Technology Data Exchange (ETDEWEB)

    Anon.

    1998-09-01

    The ``hydro-wired`` technique consists in the use of small diameter synthetic pipes for the water supply of hot or cold water to space heating or cooling appliances. This new technique has several advantages regarding the thermal comfort and the realization of installations. However cares must be taken during the application of this technique and the design of installations. This paper describes: the French potential market for this technique (heating and cooling floors, traditional heating, sanitary hot water distribution), the characteristics of this technique with respect to traditional techniques (the sheathing of pipes, the specificities of the `octopus`-type distribution), and the design of installations (the different steps: preliminary thermal analysis, realization, start-up and tests). (J.S.)

  18. THE TECHNIQUES IN TEACHING LISTENING SKILL

    Directory of Open Access Journals (Sweden)

    Hidayah Nor

    2015-12-01

    Full Text Available Listening is very important skill in language because by listening students can produce language like speaking and writing by vocabulary that they get from listening. The English teacher of MAN 3 Banjarmasin used some techniques in teaching listening using the facilities in language laboratory such as tape cassette, television, and VCD/DVD. This research described the techniques in teaching listening skill of the Islamic high school students. The subjects of this study were an English teacher and 48 students of the tenth grade at MAN 3 Banjarmasin in Academic Year 2009/2010. To collect the data, it was used some techniques such as observation, interview, and documentary. Then all data were analyzed using descriptive method qualitatively and quantitatively, by concluding inductively. The result indicates that the techniques in teaching listening applied by the English teacher of the tenth grade students at MAN 3 Banjarmasin in Academic Year 2009/2010 are: Information Transfer, Paraphrasing and Translating, Answering Questions, Summarizing, Filling in Blanks, and Answering to Show Comprehension of Messages. The students’ ability of listening comprehension using six techniques is categorized in very high, high, and average levels. Keywords: listening techniques, teaching listening skill

  19. Intraosseous anesthesia: implications, instrumentation and techniques.

    Science.gov (United States)

    Kleber, Christopher H

    2003-04-01

    The author reviews historical methods and the instruments used to bring about intraosseous anesthesia, or IOA; discusses the criteria for successful use of the intraosseous injection, or IOI, technique; and provides recommendations. Articles from before 1990 consisted of subjective reports of patient types and procedures performed using IOI as a primary technique. Studies published after 1990 yielded subjective findings on indications for expanded clinical use. The author discusses the expansion of the role of IOI relative to integrated local anesthetic delivery systems. The literature and studies verify the efficacy of IOI as a supplemental or primary technique. The author recommends anesthetics and infusion sites, and reports on the patients' perceptions of comfort. IOI can be used as a supplemental or primary technique to bring about local anesthesia in routine dental procedures. It can be used as a supplemental technique with mandibular nerve blocks to enhance deep pulpal anesthesia. It can be used as a primary technique so that patients do not experience numb lips or tongues postoperatively. Dentists can appreciate the immediate onset of anesthesia and reduced dosage levels of anesthetics associated with using IOI.

  20. A video authentication technique

    International Nuclear Information System (INIS)

    Johnson, C.S.

    1987-01-01

    Unattended video surveillance systems are particularly vulnerable to the substitution of false video images into the cable that connects the camera to the video recorder. New technology has made it practical to insert a solid state video memory into the video cable, freeze a video image from the camera, and hold this image as long as desired. Various techniques, such as line supervision and sync detection, have been used to detect video cable tampering. The video authentication technique described in this paper uses the actual video image from the camera as the basis for detecting any image substitution made during the transmission of the video image to the recorder. The technique, designed for unattended video systems, can be used for any video transmission system where a two-way digital data link can be established. The technique uses similar microprocessor circuitry at the video camera and at the video recorder to select sample points in the video image for comparison. The gray scale value of these points is compared at the recorder controller and if the values agree within limits, the image is authenticated. If a significantly different image was substituted, the comparison would fail at a number of points and the video image would not be authenticated. The video authentication system can run as a stand-alone system or at the request of another system

  1. Acceleration techniques for the discrete ordinate method

    International Nuclear Information System (INIS)

    Efremenko, Dmitry; Doicu, Adrian; Loyola, Diego; Trautmann, Thomas

    2013-01-01

    In this paper we analyze several acceleration techniques for the discrete ordinate method with matrix exponential and the small-angle modification of the radiative transfer equation. These techniques include the left eigenvectors matrix approach for computing the inverse of the right eigenvectors matrix, the telescoping technique, and the method of false discrete ordinate. The numerical simulations have shown that on average, the relative speedup of the left eigenvector matrix approach and the telescoping technique are of about 15% and 30%, respectively. -- Highlights: ► We presented the left eigenvector matrix approach. ► We analyzed the method of false discrete ordinate. ► The telescoping technique is applied for matrix operator method. ► Considered techniques accelerate the computations by 20% in average.

  2. De novo expression of sodium-glucose cotransporter SGLT2 in Bowman’s capsule coincides with replacement of parietal epithelial cell layer with proximal tubule-like epithelium

    OpenAIRE

    Tabatabai, Niloofar M.; North, Paula E.; Regner, Kevin R.; Kumar, Suresh N.; Duris, Christine B.; Blodgett, Amy B.

    2014-01-01

    In kidney nephron, parietal epithelial cells line the Bowman’s capsule and function as a permeability barrier for the glomerular filtrate. Bowman’s capsule cells with proximal tubule epithelial morphology have been found. However, the effects of tubular metaplasia in Bowman’s capsule on kidney function remain poorly understood. Sodium-glucose cotransporter 2 (SGLT2) plays a major role in reabsorption of glucose in the kidney and is expressed on brush border membrane of epithelial cells in the...

  3. Unusual case of failure to thrive: Type III Bartter syndrome.

    Science.gov (United States)

    Agrawal, S; Subedi, K; Ray, P; Rayamajhi, A

    2016-09-01

    Bartter syndrome Type III is a rare autosomal recessive disorder resulting from an inherited defect in the thick ascending limb of the loop of henle of the nephrons in kidney. The typical clinical manifestations in childhood are failure to thrive and recurrent episodes of vomiting. Typical laboratory findings which help in the diagnosis are hypokalemic metabolic alkalosis, hypomagnesemia and hypercalciuria. We report a case of Type III Bartter syndrome not responding to repeated conventional treatment of failure to thrive.

  4. Diagram Techniques in Group Theory

    Science.gov (United States)

    Stedman, Geoffrey E.

    2009-09-01

    Preface; 1. Elementary examples; 2. Angular momentum coupling diagram techniques; 3. Extension to compact simple phase groups; 4. Symmetric and unitary groups; 5. Lie groups and Lie algebras; 6. Polarisation dependence of multiphoton processes; 7. Quantum field theoretic diagram techniques for atomic systems; 8. Applications; Appendix; References; Indexes.

  5. Constant exposure technique in industrial radiography

    International Nuclear Information System (INIS)

    Domanus, J.C.

    1983-08-01

    The principles and advantages of the constant exposure technique are explained. Choice of exposure factors is analyzed. Film, paper and intensifying screens used throughout the investigation and film and paper processing are described. Exposure technique and the use of image quality indicators are given. Methods of determining of radiographic image quality are presented. Conclusions about the use of constant exposure vs. constant kilovoltage technique are formulated. (author)

  6. Huffman-based code compression techniques for embedded processors

    KAUST Repository

    Bonny, Mohamed Talal

    2010-09-01

    The size of embedded software is increasing at a rapid pace. It is often challenging and time consuming to fit an amount of required software functionality within a given hardware resource budget. Code compression is a means to alleviate the problem by providing substantial savings in terms of code size. In this article we introduce a novel and efficient hardware-supported compression technique that is based on Huffman Coding. Our technique reduces the size of the generated decoding table, which takes a large portion of the memory. It combines our previous techniques, Instruction Splitting Technique and Instruction Re-encoding Technique into new one called Combined Compression Technique to improve the final compression ratio by taking advantage of both previous techniques. The instruction Splitting Technique is instruction set architecture (ISA)-independent. It splits the instructions into portions of varying size (called patterns) before Huffman coding is applied. This technique improves the final compression ratio by more than 20% compared to other known schemes based on Huffman Coding. The average compression ratios achieved using this technique are 48% and 50% for ARM and MIPS, respectively. The Instruction Re-encoding Technique is ISA-dependent. It investigates the benefits of reencoding unused bits (we call them reencodable bits) in the instruction format for a specific application to improve the compression ratio. Reencoding those bits can reduce the size of decoding tables by up to 40%. Using this technique, we improve the final compression ratios in comparison to the first technique to 46% and 45% for ARM and MIPS, respectively (including all overhead that incurs). The Combined Compression Technique improves the compression ratio to 45% and 42% for ARM and MIPS, respectively. In our compression technique, we have conducted evaluations using a representative set of applications and we have applied each technique to two major embedded processor architectures

  7. Neutron techniques in Safeguards

    International Nuclear Information System (INIS)

    Zucker, M.S.

    1982-01-01

    An essential part of Safeguards is the ability to quantitatively and nondestructively assay those materials with special neutron-interactive properties involved in nuclear industrial or military technology. Neutron techniques have furnished most of the important ways of assaying such materials, which is no surprise since the neutronic properties are what characterizes them. The techniques employed rely on a wide selection of the many methods of neutron generation, detection, and data analysis that have been developed for neutron physics and nuclear science in general

  8. Radiographic constant exposure technique

    DEFF Research Database (Denmark)

    Domanus, Joseph Czeslaw

    1985-01-01

    The constant exposure technique has been applied to assess various industrial radiographic systems. Different X-ray films and radiographic papers of two producers were compared. Special attention was given to fast film and paper used with fluorometallic screens. Radiographic image quality...... was tested by the use of ISO wire IQI's and ASTM penetrameters used on Al and Fe test plates. Relative speed and reduction of kilovoltage obtained with the constant exposure technique were calculated. The advantages of fast radiographic systems are pointed out...

  9. Arthroscopic Latarjet Techniques: Graft and Fixation Positioning Assessed With 2-Dimensional Computed Tomography Is Not Equivalent With Standard Open Technique.

    Science.gov (United States)

    Neyton, Lionel; Barth, Johannes; Nourissat, Geoffroy; Métais, Pierre; Boileau, Pascal; Walch, Gilles; Lafosse, Laurent

    2018-05-19

    To analyze graft and fixation (screw and EndoButton) positioning after the arthroscopic Latarjet technique with 2-dimensional computed tomography (CT) and to compare it with the open technique. We performed a retrospective multicenter study (March 2013 to June 2014). The inclusion criteria included patients with recurrent anterior instability treated with the Latarjet procedure. The exclusion criterion was the absence of a postoperative CT scan. The positions of the hardware, the positions of the grafts in the axial and sagittal planes, and the dispersion of values (variability) were compared. The study included 208 patients (79 treated with open technique, 87 treated with arthroscopic Latarjet technique with screw fixation [arthro-screw], and 42 treated with arthroscopic Latarjet technique with EndoButton fixation [arthro-EndoButton]). The angulation of the screws was different in the open group versus the arthro-screw group (superior, 10.3° ± 0.7° vs 16.9° ± 1.0° [P open inferior screws (P = .003). In the axial plane (level of equator), the arthroscopic techniques resulted in lateral positions (arthro-screw, 1.5 ± 0.3 mm lateral [P open technique (0.9 ± 0.2 mm medial). At the level of 25% of the glenoid height, the arthroscopic techniques resulted in lateral positions (arthro-screw, 0.3 ± 0.3 mm lateral [P open technique (1.0 ± 0.2 mm medial). Higher variability was observed in the arthro-screw group. In the sagittal plane, the arthro-screw technique resulted in higher positions (55% ± 3% of graft below equator) and the arthro-EndoButton technique resulted in lower positions (82% ± 3%, P open technique (71% ± 2%). Variability was not different. This study shows that the position of the fixation devices and position of the bone graft with the arthroscopic techniques are statistically significantly different from those with the open technique with 2-dimensional CT assessment. In the sagittal plane, the arthro-screw technique provides the highest

  10. A comparative In vivo efficacy of three spiral techniques versus incremental technique in obturating primary teeth

    Directory of Open Access Journals (Sweden)

    Shalini Chandrasekhar

    2018-01-01

    Full Text Available Background: The aim of this study was to evaluate the efficiency of four different obturating techniques in filling the radicular space in primary teeth. Materials and Methods: This clinical trial was carried out on 34 healthy, cooperative children (5–9 years who had 63 carious primary teeth indicated for pulpectomy. They were divided into four groups, such that in each group, a total of 40 canals were allotted for obturation with respective technique. The root canals of selected primary teeth were filled with Endoflas obturating material using either bi-directional spiral (Group 1; incremental technique (Group 2, past inject (Group 3 or lentulo spiral (Group 4 according to the groups assigned. The effectiveness of the obturation techniques was assessed using postoperative radiographs. The assessment was made for a depth of fill in the canal, the presence of any voids using Modified Coll and Sadrian criteria. The obtained data were analyzed by using ANOVA test and unpaired t-test. Results: Bi-directional spiral and lentulo spiral were superior to other techniques in providing optimally filled canals (P< 0.05. The bi-directional spiral was superior to lentulo spiral in preventing overfill (P< 0.05. Conclusion: Based on the present study results, bi-directional spiral can be recommended as an alternate obturating technique in primary teeth.

  11. Materials characterization techniques

    National Research Council Canada - National Science Library

    Zhang, Sam; Li, L; Kumar, Ashok

    2009-01-01

    ... techniques for quality assurance, contamination control, and process improvement. The book reviews the most popular and powerful analysis and quality control tools, explaining the appropriate uses and related technical requirements...

  12. Vibration transducer calibration techniques

    Science.gov (United States)

    Brinkley, D. J.

    1980-09-01

    Techniques for the calibration of vibration transducers used in the Aeronautical Quality Assurance Directorate of the British Ministry of Defence are presented. Following a review of the types of measurements necessary in the calibration of vibration transducers, the performance requirements of vibration transducers, which can be used to measure acceleration, velocity or vibration amplitude, are discussed, with particular attention given to the piezoelectric accelerometer. Techniques for the accurate measurement of sinusoidal vibration amplitude in reference-grade transducers are then considered, including the use of a position sensitive photocell and the use of a Michelson laser interferometer. Means of comparing the output of working-grade accelerometers with that of previously calibrated reference-grade devices are then outlined, with attention given to a method employing a capacitance bridge technique and a method to be used at temperatures between -50 and 200 C. Automatic calibration procedures developed to speed up the calibration process are outlined, and future possible extensions of system software are indicated.

  13. Empirical techniques in finance

    CERN Document Server

    Bhar, Ramaprasad

    2005-01-01

    This book offers the opportunity to study and experience advanced empi- cal techniques in finance and in general financial economics. It is not only suitable for students with an interest in the field, it is also highly rec- mended for academic researchers as well as the researchers in the industry. The book focuses on the contemporary empirical techniques used in the analysis of financial markets and how these are implemented using actual market data. With an emphasis on Implementation, this book helps foc- ing on strategies for rigorously combing finance theory and modeling technology to extend extant considerations in the literature. The main aim of this book is to equip the readers with an array of tools and techniques that will allow them to explore financial market problems with a fresh perspective. In this sense it is not another volume in eco- metrics. Of course, the traditional econometric methods are still valid and important; the contents of this book will bring in other related modeling topics tha...

  14. Radiation techniques for acromegaly

    Directory of Open Access Journals (Sweden)

    Minniti Giuseppe

    2011-12-01

    Full Text Available Abstract Radiotherapy (RT remains an effective treatment in patients with acromegaly refractory to medical and/or surgical interventions, with durable tumor control and biochemical remission; however, there are still concerns about delayed biochemical effect and potential late toxicity of radiation treatment, especially high rates of hypopituitarism. Stereotactic radiotherapy has been developed as a more accurate technique of irradiation with more precise tumour localization and consequently a reduction in the volume of normal tissue, particularly the brain, irradiated to high radiation doses. Radiation can be delivered in a single fraction by stereotactic radiosurgery (SRS or as fractionated stereotactic radiotherapy (FSRT in which smaller doses are delivered over 5-6 weeks in 25-30 treatments. A review of the recent literature suggests that pituitary irradiation is an effective treatment for acromegaly. Stereotactic techniques for GH-secreting pituitary tumors are discussed with the aim to define the efficacy and potential adverse effects of each of these techniques.

  15. Radiation techniques for acromegaly

    International Nuclear Information System (INIS)

    Minniti, Giuseppe; Scaringi, Claudia; Enrici, Riccardo Maurizi

    2011-01-01

    Radiotherapy (RT) remains an effective treatment in patients with acromegaly refractory to medical and/or surgical interventions, with durable tumor control and biochemical remission; however, there are still concerns about delayed biochemical effect and potential late toxicity of radiation treatment, especially high rates of hypopituitarism. Stereotactic radiotherapy has been developed as a more accurate technique of irradiation with more precise tumour localization and consequently a reduction in the volume of normal tissue, particularly the brain, irradiated to high radiation doses. Radiation can be delivered in a single fraction by stereotactic radiosurgery (SRS) or as fractionated stereotactic radiotherapy (FSRT) in which smaller doses are delivered over 5-6 weeks in 25-30 treatments. A review of the recent literature suggests that pituitary irradiation is an effective treatment for acromegaly. Stereotactic techniques for GH-secreting pituitary tumors are discussed with the aim to define the efficacy and potential adverse effects of each of these techniques

  16. Ion beam techniques in arts and archaeology

    International Nuclear Information System (INIS)

    Qin Guangyong; Pan Xianjia; Sun Zhongtian; Gao Zhengyao

    1991-01-01

    The ion beam techniques used in studies of arts and archaeology are compared with other analytical techniques. Some examples are specially selected to illustrate the achievements and trends of the techniques in this field

  17. Radar rainfall image repair techniques

    Directory of Open Access Journals (Sweden)

    Stephen M. Wesson

    2004-01-01

    Full Text Available There are various quality problems associated with radar rainfall data viewed in images that include ground clutter, beam blocking and anomalous propagation, to name a few. To obtain the best rainfall estimate possible, techniques for removing ground clutter (non-meteorological echoes that influence radar data quality on 2-D radar rainfall image data sets are presented here. These techniques concentrate on repairing the images in both a computationally fast and accurate manner, and are nearest neighbour techniques of two sub-types: Individual Target and Border Tracing. The contaminated data is estimated through Kriging, considered the optimal technique for the spatial interpolation of Gaussian data, where the 'screening effect' that occurs with the Kriging weighting distribution around target points is exploited to ensure computational efficiency. Matrix rank reduction techniques in combination with Singular Value Decomposition (SVD are also suggested for finding an efficient solution to the Kriging Equations which can cope with near singular systems. Rainfall estimation at ground level from radar rainfall volume scan data is of interest and importance in earth bound applications such as hydrology and agriculture. As an extension of the above, Ordinary Kriging is applied to three-dimensional radar rainfall data to estimate rainfall rate at ground level. Keywords: ground clutter, data infilling, Ordinary Kriging, nearest neighbours, Singular Value Decomposition, border tracing, computation time, ground level rainfall estimation

  18. Healthy Cooking Techniques

    Science.gov (United States)

    Healthy Lifestyle Nutrition and healthy eating Healthy-cooking techniques capture the flavor and nutrients of food without extra fat or salt. By Mayo Clinic Staff Healthy cooking doesn't mean that ...

  19. [Update in continuous renal replacement techniques].

    Science.gov (United States)

    Romero-García, M; de la Cueva-Ariza, L; Delgado-Hito, P

    2013-01-01

    Acute renal failure affects 25% of patients hospitalized in intensive care units. Despite technological advances, the mortality of these patients is still high due to its associated complications. Continuous renal replacement techniques are one of the treatments for acute renal failure because they make it possible to treat the complications and decrease mortality. The nurse's knowledge and skills regarding these techniques will be decisive for the success of the therapy. Consequently, the nurse's experience and training are key components. The objective of this article is to update the knowledge on continuous renal replacement techniques. Keeping this in mind, a review has been made of the physical and chemical principles such as diffusion and convection, among others. A description of the different continuous renal replacement techniques, a presentation of the main vascular access, and a description of the nursing cares and complications related to techniques used have also been provided. Copyright © 2012 Elsevier España, S.L. y SEEIUC. All rights reserved.

  20. Astrophysical techniques

    CERN Document Server

    Kitchin, CR

    2013-01-01

    DetectorsOptical DetectionRadio and Microwave DetectionX-Ray and Gamma-Ray DetectionCosmic Ray DetectorsNeutrino DetectorsGravitational Radiation Dark Matter and Dark Energy Detection ImagingThe Inverse ProblemPhotographyElectronic ImagingScanningInterferometrySpeckle InterferometryOccultationsRadarElectronic ImagesPhotometryPhotometryPhotometersSpectroscopySpectroscopy SpectroscopesOther TechniquesAstrometryPolarimetrySolar StudiesMagnetometryComputers and The Internet.

  1. Techniques for Improving Cash Management.

    Science.gov (United States)

    Lykins, Ronald G.

    1973-01-01

    This article deals with several techniques for regulating cash inflow and outflow and investing surplus cash for short periods of time. The techniques are: (1) consolidating checking accounts, (2) determining surplus cash by examining bank balances in conjunction with the cash book, (3) selecting a minimum bank balance, (4) investing a greater…

  2. Radioisotope Sample Measurement Techniques in Medicine and Biology. Proceedings of the Symposium on Radioisotope Sample Measurement Techniques

    International Nuclear Information System (INIS)

    1965-01-01

    The medical and biological applications of radioisotopes depend on two basically different types of measurements, those on living subjects in vivo and those on samples in vitro. The International Atomic Energy Agency has in the past held several meetings on in vivo measurement techniques, notably whole-body counting and radioisotope scanning. The present volume contains the Proceedings of the first Symposium the Agency has organized to discuss the various aspects of techniques for sample measurement in vitro. The range of these sample measurement techniques is very wide. The sample may weigh a few milligrams or several hundred grams, and may be in the gaseous, liquid or solid state. Its radioactive content may consist of a single, known radioisotope or several unknown ones. The concentration of radioactivity may be low, medium or high. The measurements may be made manually or automatically and any one of the many radiation detectors now available may be used. The 53 papers presented at the Symposium illustrate the great variety of methods now in use for radioactive- sample measurements. The first topic discussed is gamma-ray spectrometry, which finds an increasing number of applications in sample measurements. Other sections of the Proceedings deal with: the use of computers in gamma-ray spectrometry and multiple tracer techniques; recent developments in activation analysis where both gamma-ray spectrometry and computing techniques are applied; thin-layer and paper radio chromatographic techniques for use with low energy beta-ray emitters; various aspects of liquid scintillation counting techniques in the measurement of alpha- and beta-ray emitters, including chemical and colour quenching; autoradiographic techniques; calibration of equipment; and standardization of radioisotopes. Finally, some applications of solid-state detectors are presented; this section may be regarded as a preview of important future developments. The meeting was attended by 203 participants

  3. The Q sort theory and technique.

    Science.gov (United States)

    Nyatanga, L

    1989-10-01

    This paper is based on the author's experience of using the Q sort technique with BA Social Sciences (BASS) students, and the community psychiatric nursing (CPN, ENB No 811 course). The paper focuses on two main issues: 1. The theoretical assumptions underpinning the Q Sort technique. Carl Rogers' self theory and some of the values of humanistic psychology are summarised. 2. The actual technique procedure and meaning of results are highlighted. As the Q Sort technique is potentially useful in a variety of sittings some of which are listed in this paper, the emphasis has deliberately been placed in understanding the theoretical underpinning and the operationalisation (sensitive interpretation) of the theory to practice.

  4. The effect of L-NAME on intra- and inter-nephron synchronization

    DEFF Research Database (Denmark)

    Sosnovtseva, Olga; Pavlov, A. N.; Pavlova, O. N.

    2009-01-01

    to what extent these phenomena are reflected in the overall blood flow to the kidney and how they are affected by intravenous administration of nitro-l-arginine-methyl-ester (L-NAME), a potent NO synthesis inhibitor. Wavelet analysis is applied to detect rhythmic activity at the level of the renal artery...

  5. Effects of Reactive Oxygen Species on Tubular Transport along the Nephron.

    Science.gov (United States)

    Gonzalez-Vicente, Agustin; Garvin, Jeffrey L

    2017-03-23

    Reactive oxygen species (ROS) are oxygen-containing molecules naturally occurring in both inorganic and biological chemical systems. Due to their high reactivity and potentially damaging effects to biomolecules, cells express a battery of enzymes to rapidly metabolize them to innocuous intermediaries. Initially, ROS were considered by biologists as dangerous byproducts of respiration capable of causing oxidative stress, a condition in which overproduction of ROS leads to a reduction in protective molecules and enzymes and consequent damage to lipids, proteins, and DNA. In fact, ROS are used by immune systems to kill virus and bacteria, causing inflammation and local tissue damage. Today, we know that the functions of ROS are not so limited, and that they also act as signaling molecules mediating processes as diverse as gene expression, mechanosensation, and epithelial transport. In the kidney, ROS such as nitric oxide (NO), superoxide (O₂ - ), and their derivative molecules hydrogen peroxide (H₂O₂) and peroxynitrite (ONO₂ - ) regulate solute and water reabsorption, which is vital to maintain electrolyte homeostasis and extracellular fluid volume. This article reviews the effects of NO, O₂ - , ONO₂ - , and H₂O₂ on water and electrolyte reabsorption in proximal tubules, thick ascending limbs, and collecting ducts, and the effects of NO and O₂ - in the macula densa on tubuloglomerular feedback.

  6. Heterogeneity of uridine incorporation along the rabbit nephron. I. Autoradiographic study

    International Nuclear Information System (INIS)

    Vandewalle, A.; Farman, N.; Cluzeaud, F.; Bonvalet, J.P.

    1984-01-01

    An autoradiographic study of uridine labeling in tubular segments microdissected from the rabbit kidney is presented. Kidney pyramids were incubated for 60 min with low (66 nM) and high (66μM) [ 3 H]-uridine concentration. At the two concentrations studied the labeling was almost exclusively nuclear in all segments studied. At the low concentration, labeling predominated in the macula densa (MD = 63.88 +/- 6.15 silver grains/100 μm 2 , n = 11), cortical ascending limb (CAL = 19.65 +/- 1.65, n = 15), and initial distal tubule (DCT/sub a/ = 24.31 +/- 2.70, n = 6). It was minimal in the proximal tubule (PCT 2 = 9.14 +/- 1.61, n = 16) and in the cortical (CCT = 5.23 +/- 0.75, n = 18) and medullary (MCT = 5.52 +/- 1.10, n = 12) collecting ducts. At a high concentration, the profile of labeling was roughly similar except for a relative increase in labeling much more pronounced in collecting ducts (CCT = +373, MCT = +323%) than in the other structures (MD = -14, CAL = +66, DCT/sub a/ = +49, PCT = +9%). Pulse-chase experiments do not show evidence for differences in turnover or degradation rates of RNA between segments, at least in the PCT and the connecting part of the CCT. Analysis of the results at low and high concentration suggests that the observed heterogeneity in uridine labeling depends on both variable endogenous nucleoside pools and different rates of uridine incorporation into RNA from one segment to another

  7. Heterogeneity of uridine incorporation along the rabbit nephron. I. Autoradiographic study

    Energy Technology Data Exchange (ETDEWEB)

    Vandewalle, A.; Farman, N.; Cluzeaud, F.; Bonvalet, J.P.

    1984-04-01

    An autoradiographic study of uridine labeling in tubular segments microdissected from the rabbit kidney is presented. Kidney pyramids were incubated for 60 min with low (66 nM) and high (66..mu..M) (/sup 3/H)-uridine concentration. At the two concentrations studied the labeling was almost exclusively nuclear in all segments studied. At the low concentration, labeling predominated in the macula densa (MD = 63.88 +/- 6.15 silver grains/100 ..mu..m/sup 2/, n = 11), cortical ascending limb (CAL = 19.65 +/- 1.65, n = 15), and initial distal tubule (DCT/sub a/ = 24.31 +/- 2.70, n = 6). It was minimal in the proximal tubule (PCT/sub 2/ = 9.14 +/- 1.61, n = 16) and in the cortical (CCT = 5.23 +/- 0.75, n = 18) and medullary (MCT = 5.52 +/- 1.10, n = 12) collecting ducts. At a high concentration, the profile of labeling was roughly similar except for a relative increase in labeling much more pronounced in collecting ducts (CCT = +373, MCT = +323%) than in the other structures (MD = -14, CAL = +66, DCT/sub a/ = +49, PCT = +9%). Pulse-chase experiments do not show evidence for differences in turnover or degradation rates of RNA between segments, at least in the PCT and the connecting part of the CCT. Analysis of the results at low and high concentration suggests that the observed heterogeneity in uridine labeling depends on both variable endogenous nucleoside pools and different rates of uridine incorporation into RNA from one segment to another.

  8. Doppler ultrasound surveillance in deep tunneling compressed-air work with Trimix breathing: bounce dive technique compared to saturation-excursion technique.

    Science.gov (United States)

    Vellinga, T P van Rees; Sterk, W; de Boer, A G E M; van der Beek, A J; Verhoeven, A C; van Dijk, F J H

    2008-01-01

    The Western Scheldt Tunneling Project in The Netherlands provided a unique opportunity to evaluate two deep-diving techniques with Doppler ultrasound surveillance. Divers used the bounce diving techniques for repair and maintenance of the TBM. The tunnel boring machine jammed at its deepest depth. As a result the work time was not sufficient. The saturation diving technique was developed and permitted longer work time at great depth. Thirty-one divers were involved in this project. Twenty-three divers were examined using Doppler ultrasound. Data analysis addressed 52 exposures to Trimix at 4.6-4.8 bar gauge using the bounce technique and 354 exposures to Trimix at 4.0-6.9 bar gauge on saturation excursions. No decompression incidents occurred with either technique during the described phase of the project. Doppler ultrasound revealed that the bubble loads assessed in both techniques were generally low. We find out, that despite longer working hours, shorter decompression times and larger physical workloads, the saturation-excursion technique was associated with significant lower bubble grades than in the bounce technique using Doppler Ultrasound. We conclude that the saturation-excursion technique with Trimix is a good option for deep and long exposures in caisson work. The Doppler technique proved valuable, and it should be incorporated in future compressed-air work.

  9. Premature Ejaculation and Utilization of Cognitive Techniques

    Directory of Open Access Journals (Sweden)

    Serkan AKKOYUNLU

    2013-03-01

    Full Text Available Introduction: Premature ejaculation is the most common male sexual dysfunction leading to distress in many couples. Master and Johnson emphasized the concept of early learned experiences and Kaplan emphasized lack of sensory awareness. For treatment sex therapists mainly utilize start-stop and squeeze techniques as homework. Couples enter sex therapy with some cognitive distortions and beliefs about sex and sexuality. These beliefs are also named sexual myths. For some couples using techniques to challenge cognitive distortions and maladaptive beliefs about sex and sexuality can be used. In this paper by presenting a case we discussed how cognitive techniques can be used along with behaviour techniques with couples. Case: Presenting clients are five years married couple who are thirty and twenty nine years old respectively. They attended to the outpatient clinic with the request of the female client. Their main complaint was premature ejaculation. They were diagnosed premature ejaculation using clinical interview. In treatment besides start and stop technique, cognitive techniques were utilized to address dysfunctional beliefs about sexuality. Discussion: Premature ejaculation is a male sexual dysfunction that causes distress and intimacy problems between couples. Stop start and squeeze techniques were accepted as the choice of treatment but their effectiveness is questioned recently. Also cognitive distortions and maladaptive beliefs may hamper therapy progress. Besides that, behavioral techniques utilizing cognitive techniques to lessen the degree of dysfunctional beliefs about sex and sexuality may help the couple to overcome premature ejaculation and enhance sexual satisfaction and intimacy.

  10. Dual kidney transplant techniques: A systematic review.

    Science.gov (United States)

    Cocco, Annelise; Shahrestani, Sara; Cocco, Nicholas; Hameed, Ahmer; Yuen, Lawrence; Ryan, Brendan; Hawthorne, Wayne; Lam, Vincent; Pleass, Henry

    2017-08-01

    Dual kidney transplantation (DKT) was developed to improve outcomes from transplantation of extended criteria donors (ECD). This study examined which surgical techniques have been reported for DKT and whether any technique had superior patient and graft survival. Electronic databases were searched for published studies mapping to MESH terms: "kidney or renal" AND "transplan*" AND "dual or double." Single case reports, studies of patients less than 18 years old, studies which did not describe the surgical technique, and studies that did not report patient or graft survival were excluded. Fifteen reports of 434 DKT recipients were identified. Three techniques were described: bilateral placement; unilateral placement with separate anastomoses; and unilateral placement with patch anastomoses. Patient survival across all three techniques was over 95% at 1 year, and graft survival was also similar at over 90%. Rates of delayed graft function were between 20% and 30% across all techniques. The three techniques have equivalent delayed graft function as well as patient and graft survival rates. This is an encouraging result as it means that the surgeon can choose to use the technique which is most appropriate for their own skills and for the patient. © 2017 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  11. Modified grassline technique for orthodontic space closure.

    Science.gov (United States)

    Lohmiller, Rose Marie

    2006-04-01

    Use of traditional orthodontic measures in the periodontally compromised dentition can be problematic. This article describes a variation of the Grassline technique, in which the author uses adhesive bonding to harmoniously re-align malpositioned teeth. In this simple, easy-to-learn technique, a cotton thread is used to achieve orthodontic tooth movement. Initial contact with the saliva causes shrinkage of the thread, exercising a minor force that moves the teeth while allowing enough time for the tissues to regenerate. With this moderate, intermittent force, successful treatment is achieved with minimal risk. Moreover, this orthodontic technique has been associated with an increase in bone volume. This article presents this new technique and details methods for maintaining treatment success. The technique also is compared with an approach described in the literature. Two case reports are presented; the technique is employed in the first to close a diastema in a periodontally compromised dentition and in the second to correct the migration of maxillary and mandibular incisors. Photographs and radiographs show the esthetic improvement achieved in both cases using this technique.

  12. Resolution enhancement techniques in microscopy

    Science.gov (United States)

    Cremer, Christoph; Masters, Barry R.

    2013-05-01

    We survey the history of resolution enhancement techniques in microscopy and their impact on current research in biomedicine. Often these techniques are labeled superresolution, or enhanced resolution microscopy, or light-optical nanoscopy. First, we introduce the development of diffraction theory in its relation to enhanced resolution; then we explore the foundations of resolution as expounded by the astronomers and the physicists and describe the conditions for which they apply. Then we elucidate Ernst Abbe's theory of optical formation in the microscope, and its experimental verification and dissemination to the world wide microscope communities. Second, we describe and compare the early techniques that can enhance the resolution of the microscope. Third, we present the historical development of various techniques that substantially enhance the optical resolution of the light microscope. These enhanced resolution techniques in their modern form constitute an active area of research with seminal applications in biology and medicine. Our historical survey of the field of resolution enhancement uncovers many examples of reinvention, rediscovery, and independent invention and development of similar proposals, concepts, techniques, and instruments. Attribution of credit is therefore confounded by the fact that for understandable reasons authors stress the achievements from their own research groups and sometimes obfuscate their contributions and the prior art of others. In some cases, attribution of credit is also made more complex by the fact that long term developments are difficult to allocate to a specific individual because of the many mutual connections often existing between sometimes fiercely competing, sometimes strongly collaborating groups. Since applications in biology and medicine have been a major driving force in the development of resolution enhancing approaches, we focus on the contribution of enhanced resolution to these fields.

  13. Progress involving new techniques for liposome preparation

    Directory of Open Access Journals (Sweden)

    Zhenjun Huang

    2014-08-01

    Full Text Available The article presents a review of new techniques being used for the preparation of liposomes. A total of 28 publications were examined. In addition to the theories, characteristics and problems associated with traditional methods, the advantages and drawbacks of the latest techniques were reviewed. In the light of developments in many relevant areas, a variety of new techniques are being used for liposome preparation and each of these new technique has particular advantages over conventional preparation methods. However, there are still some problems associated with these new techniques that could hinder their applications and further improvements are needed. Generally speaking, due to the introduction of these latest techniques, liposome preparation is now an improved procedure. These applications promote not only advances in liposome research but also the methods for their production on an industrial scale.

  14. Hlaallele Detection Using Molecular Techniques

    Directory of Open Access Journals (Sweden)

    Philip A. Dyer

    1993-01-01

    Full Text Available There are now many molecular biological techniques available to define HLA class I and class II alleles. Some of these are also applicable to other human polymorphic genes, in particular to those non-HLA genes encoded within the Mhc. The range of techniques available allows laboratories to choose those most suited to their purpose. The routine laboratory supporting solid organ transplants will need to type large numbers of potential recipients over a period of time, probably using PCR-SSOP while donors will be typed singly and rapidly using PCR-SSP with HLA allele compatibility determined by heteroduplex analysis. Laboratories supporting bone marrow transplantation, where time is less pressing, can choose from the whole range of techniques to determine accurately donor recipient Mhc compatibility. For disease studies, techniques defining precise HLA allele sequence polymorphisms are needed and high sample numbers have to be accommodated. When an association is established allele sequencing has to be used. In the near future, the precise role of HLA alleles in transplantation and disease susceptibility is likely to be established unambiguously.

  15. The Algebraic Reconstruction Technique (ART)

    International Nuclear Information System (INIS)

    Raparia, D.; Alessi, J.; Kponou, A.

    1997-01-01

    Projections of charged particle beam current density (profiles) are frequently used as a measure of beam position and size. In conventional practice only two projections, usually horizontal and vertical, are measured. This puts a severe limit on the detail of information that can be achieved. A third projection provides a significant improvement. The Algebraic Reconstruction Technique (ART) uses three or more projections to reconstruct 3-dimensional density profiles. At the 200 MeV H-linac, we have used this technique to measure beam density, and it has proved very helpful, especially in helping determine if there is any coupling present in x-y phase space. We will present examples of measurements of current densities using this technique

  16. New techniques in neutron scattering

    International Nuclear Information System (INIS)

    Hayter, J.B.

    1993-01-01

    New neutron sources being planned, such as the Advanced Neutron Source (ANS) or the European Spallation Source (ESS), will provide an order of magnitude flux increase over what is available today, but neutron scattering will still remain a signal-limited technique. At the same time, the development of new materials, such as polymer and ceramic composites or a variety of complex fluids, will increasingly require neutron-based research. This paper will discuss some of the new techniques which will allow us to make better use of the available neutrons, either through improved instrumentation or through sample manipulation. Discussion will center primarily on unpolarized neutron techniques since polarized neutrons will be the subject of the next paper. (author)

  17. Transvaginal Cystocele Repair by Purse-String Technique Reinforced with Three Simple Sutures: Surgical Technique and Results

    Directory of Open Access Journals (Sweden)

    Ho-Sook Song

    2012-09-01

    Full Text Available Purpose Different techniques for cystocele repair including the conventional anterior colporrhaphy and mesh technique are known. Our goal was to evaluate the anatomical success and safety of our method of transvaginal anterior vaginal wall repair by the purse-string technique reinforced with three simple additional sutures in the repair of cystocele over a 4-year follow-up period. Methods This was a retrospective review of 69 consecutive patients (grades 2 to 4 who underwent the above operations between 2001 and 2011, including their success rates as assessed by use of the Baden-Walker halfway classification system. Results Of the patients, 62 patients (98% were completely cured of cystocele and 1 patient showed grade 2 cystocele recurrence that required no further treatment. Two patients with grade 4 cystocele were completely cured. There was no vaginal erosion related to the cystocele repair. Conclusions Transvaginal anterior colporrhaphy by a purse-string technique reinforced with simple additive sutures appears to be a simple, safe, and easily performed approach in cystocele repair. There is no need for other material for reinforcement, even in high-grade cystocele, which is an advantage of our technique.

  18. Magnetic characterization techniques for nanomaterials

    CERN Document Server

    2017-01-01

    Sixth volume of a 40 volume series on nanoscience and nanotechnology, edited by the renowned scientist Challa S.S.R. Kumar. This handbook gives a comprehensive overview about Magnetic Characterization Techniques for Nanomaterials. Modern applications and state-of-the-art techniques are covered and make this volume an essential reading for research scientists in academia and industry.

  19. Q-Technique and Graphics Research.

    Science.gov (United States)

    Kahle, Roger R.

    Because Q-technique is as appropriate for use with visual and design items as for use with words, it is not stymied by the topics one is likely to encounter in graphics research. In particular Q-technique is suitable for studying the so-called "congeniality" of typography, for various copytesting usages, and for multivariate graphics research. The…

  20. Stochastic Feedforward Control Technique

    Science.gov (United States)

    Halyo, Nesim

    1990-01-01

    Class of commanded trajectories modeled as stochastic process. Advanced Transport Operating Systems (ATOPS) research and development program conducted by NASA Langley Research Center aimed at developing capabilities for increases in capacities of airports, safe and accurate flight in adverse weather conditions including shear, winds, avoidance of wake vortexes, and reduced consumption of fuel. Advances in techniques for design of modern controls and increased capabilities of digital flight computers coupled with accurate guidance information from Microwave Landing System (MLS). Stochastic feedforward control technique developed within context of ATOPS program.

  1. Regulation of transport in the connecting tubule and cortical collecting duct

    Science.gov (United States)

    Staruschenko, Alexander

    2012-01-01

    The central goal of this overview article is to summarize recent findings in renal epithelial transport, focusing chiefly on the connecting tubule (CNT) and the cortical collecting duct (CCD). Mammalian CCD and CNT are involved in fine tuning of electrolyte and fluid balance through reabsorption and secretion. Specific transporters and channels mediate vectorial movements of water and solutes in these segments. Although only a small percent of the glomerular filtrate reaches the CNT and CCD, these segments are critical for water and electrolyte homeostasis since several hormones, e.g. aldosterone and arginine vasopressin, exert their main effects in these nephron sites. Importantly, hormones regulate the function of the entire nephron and kidney by affecting channels and transporters in the CNT and CCD. Knowledge about the physiological and pathophysiological regulation of transport in the CNT and CCD and particular roles of specific channels/transporters has increased tremendously over the last two decades. Recent studies shed new light on several key questions concerning the regulation of renal transport. Precise distribution patterns of transport proteins in the CCD and CNT will be reviewed, and their physiological roles and mechanisms mediating ion transport in these segments will be also covered. Special emphasis will be given to pathophysiological conditions appearing as a result of abnormalities in renal transport in the CNT and CCD. PMID:23227301

  2. Hoxd11 specifies a program of metanephric kidney development within the intermediate mesoderm of the mouse embryo.

    Science.gov (United States)

    Mugford, Joshua W; Sipilä, Petra; Kobayashi, Akio; Behringer, Richard R; McMahon, Andrew P

    2008-07-15

    The mammalian kidney consists of an array of tubules connected to a ductal system that collectively function to control water/salt balance and to remove waste from the organisms' circulatory system. During mammalian embryogenesis, three kidney structures form within the intermediate mesoderm. The two most anterior structures, the pronephros and the mesonephros, are transitory and largely non-functional, while the most posterior, the metanephros, persists as the adult kidney. We have explored the mechanisms underlying regional specific differentiation of the kidney forming mesoderm. Previous studies have shown a requirement for Hox11 paralogs (Hoxa11, Hoxc11 and Hoxd11) in metanephric development. Mice lacking all Hox11 activity fail to form metanephric kidney structures. We demonstrate that the Hox11 paralog expression is restricted in the intermediate mesoderm to the posterior, metanephric level. When Hoxd11 is ectopically activated in the anterior mesonephros, we observe a partial transformation to a metanephric program of development. Anterior Hoxd11(+) cells activate Six2, a transcription factor required for the maintenance of metanephric tubule progenitors. Additionally, Hoxd11(+) mesonephric tubules exhibit an altered morphology and activate several metanephric specific markers normally confined to distal portions of the functional nephron. Collectively, our data support a model where Hox11 paralogs specify a metanephric developmental program in responsive intermediate mesoderm. This program maintains tubule forming progenitors and instructs a metanephric specific pattern of nephron differentiation.

  3. Polycystin 1 loss of function is directly linked to an imbalance in G-protein signaling in the kidney.

    Science.gov (United States)

    Zhang, Bo; Tran, Uyen; Wessely, Oliver

    2018-03-22

    The development of the kidney relies on the establishment and maintenance of a precise tubular diameter of its functional units, the nephrons. This process is disrupted in polycystic kidney disease (PKD), resulting in dilations of the nephron and renal cyst formation. In the course of exploring G-protein-coupled signaling in the Xenopus pronephric kidney, we discovered that loss of the G-protein α subunit, Gnas, results in a PKD phenotype. Polycystin 1, one of the genes mutated in human PKD, encodes a protein resembling a G-protein-coupled receptor. Furthermore, deletion of the G-protein-binding domain present in the intracellular C terminus of polycystin 1 impacts functionality. A comprehensive analysis of all the G-protein α subunits expressed in the Xenopus pronephric kidney demonstrates that polycystin 1 recruits a select subset of G-protein α subunits and that their knockdown - as in the case of Gnas - results in a PKD phenotype. Mechanistically, the phenotype is caused by increased endogenous G-protein β/γ signaling and can be reversed by pharmacological inhibitors as well as knocking down Gnb1. Together, our data support the hypothesis that G proteins are recruited to the intracellular domain of PKD1 and that this interaction is crucial for its function in the kidney. © 2018. Published by The Company of Biologists Ltd.

  4. How Kidney Cell Death Induces Renal Necroinflammation.

    Science.gov (United States)

    Mulay, Shrikant R; Kumar, Santhosh V; Lech, Maciej; Desai, Jyaysi; Anders, Hans-Joachim

    2016-05-01

    The nephrons of the kidney are independent functional units harboring cells of a low turnover during homeostasis. As such, physiological renal cell death is a rather rare event and dead cells are flushed away rapidly with the urinary flow. Renal cell necrosis occurs in acute kidney injuries such as thrombotic microangiopathies, necrotizing glomerulonephritis, or tubular necrosis. All of these are associated with intense intrarenal inflammation, which contributes to further renal cell loss, an autoamplifying process referred to as necroinflammation. But how does renal cell necrosis trigger inflammation? Here, we discuss the role of danger-associated molecular patterns (DAMPs), mitochondrial (mito)-DAMPs, and alarmins, as well as their respective pattern recognition receptors. The capacity of DAMPs and alarmins to trigger cytokine and chemokine release initiates the recruitment of leukocytes into the kidney that further amplify necroinflammation. Infiltrating neutrophils often undergo neutrophil extracellular trap formation associated with neutrophil death or necroptosis, which implies a release of histones, which act not only as DAMPs but also elicit direct cytotoxic effects on renal cells, namely endothelial cells. Proinflammatory macrophages and eventually cytotoxic T cells further drive kidney cell death and inflammation. Dissecting the molecular mechanisms of necroinflammation may help to identify the best therapeutic targets to limit nephron loss in kidney injury. Copyright © 2016 Elsevier Inc. All rights reserved.

  5. The Dermal Apron Technique for Immediate Implant Socket Management: A Novel Technique.

    Science.gov (United States)

    Levin, Barry P

    2016-01-01

    With immediate implant placement and provisionalization (IIP) in the esthetic zone, measures to counter hard and soft tissue loss are frequently necessary. To reduce the morbidity associated with bone and connective tissue procurement, various exogenous materials are utilized. The "Dermal Apron Technique" presented in this article demonstrates the use of a composite bone particulate (allograft/xenograft) plus a dermal allograft, adapted around screw-retained temporary crowns and secured within a subperiosteal pouch. The purpose is to augment the thickness of peri-implant mucosa for the purpose of preserving ridge dimensions and preventing mucosal recession. Controlled studies are required to further support its use. Clinical significance: Soft tissue health and harmony are critical for successful implant therapy in the esthetic regions of the dentition. Often, autogenous soft tissue grafts are used to augment peri-implant soft tissues. The Dermal Apron Technique is a method, that in specific situations, obviates the need for autogenous grafting. This reduces treatment time and morbidity associated with procurement of these grafts. The Dermal Apron Technique is used simultaneous with immediate placement and provisionalization and can improve long-term esthetic outcomes for patients. © 2016 Wiley Periodicals, Inc.

  6. Development of hotcell non-destructive examination techniques

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Young Uhn; Yu, S. C.; Kang, B. S.; Byun, K. S. [Chungbuk National University, Chungju (Korea)

    2002-01-01

    The purpose of this project is to establish non-destructive examination techniques which needs to determine the status of spent nuclear fuel and/or bundles. Through the project, we will establish an image reconstruction tomography which is a kind of non-destructive techniques in Hotcell. The tomography technique can be used to identify the 2-dimensional density distribution of fission products in the spent fuel rods and/or bundles. And form results of the measurement and analysis of magnetic properties of neutron irradiated material in the press vessel and reactor, we will develop some techniques to test its hardness and defects. In 2001, the first year, we have established mathematical background and necessary data and informations to develop the techniques. We will try to find some experimental results that are necessary in developing the Hotcell non-destructive examination techniques in the coming year. 14 refs., 65 figs., 5 tabs. (Author)

  7. A new neutron noise technique for fast reactors

    International Nuclear Information System (INIS)

    Zhuo Fengguan; Jin Manyi; Yao Shigui; Su Zhuting

    1987-12-01

    This paper gives a new neutron noise technique for fast reactors, which is known as thermalization measurement technique of the neutron noise. The theoretical formulas of the technique were developed, and a digital delayed coincidence time analyzer consisted of TTL integrated circuits was constructed for the study of this technique. The technique has been tested and applied practically at Df-VI fast zero power reactor. It was shown that the provided technique in this work has a number of significant advantages in comparison with the conventional neutron noise method

  8. Seminar on Detectors and measurements techniques

    International Nuclear Information System (INIS)

    Holm, E.

    2002-01-01

    A Nordic Seminar on detectors and radionuclide measurement techniques was held in Lund, Sweden, May 3-4, 2001. The objective was to highlight recent progress and problems for techniques to study environmental radioactivity. It covered the aspect of detector sample geometry's and methods for evaluation of gamma gamma pulse height distributions. Within the field of alpha-spectrometric techniques gridded ionisation chambers, semiconductor detectors and a general description for analysis of alpha-particle-spectra were presented. Recent development in mass spectrometric techniques, AMS (Accelerator Mass Spectrometry) and ICPMS (Inductively Coupled Plasma mass Spectrometry) for long-lived radionuclides was described. Principles for analysis of beta particle emitters, especially by liquid scintillation were presented. The seminar also covered radiochemistry such advantages and disadvantages between ion exchange, solvent extraction and extraction chromatography. The use of controlled laboratory conditions for discerning the dynamics of accumulation in organisms was demonstrated. Other techniques such as neutron activation were also shown to be useful analytical tool for certain long-lived radionuclides. The results of the intercalibration exercises within the Nordic countries showed the importance of such analytical quality control. (au)

  9. A new technique in the surgical treatment of Hangman's fractures: Neurospinal Academy (NSA) technique.

    Science.gov (United States)

    Dalbayrak, Sedat; Yaman, Onur; Yılmaz, Mesut

    2013-07-01

    Treatment of Hangman's fractures is still controversial. Hangman's fractures Type II and IIA are usually treated with surgical procedures. This study aims at describing the Neurospinal Academy (NSA) technique as an attempt to achieve an approximation of the fracture line to the axis body, which may be used for Type II and IIA patients with severe displacement and angulation. NSA technique both pars or pedicle screws are placed bicortically to ensure that anterior surface of C2 vertebral body will be crossed 1-2 mm. A rod is prepared in suitable length and curve to connect the two screws. For placing the rod, sufficient amount of bone is resected from the C2 spinous process. C2 vertebral body is pulled back by means of the screws that crossed the anterior surface of C2 vertebral body. Hangman II and IIA patient are treated with NSA technique. Angulated and tilted C2 vertebral body was pulled back and approximated to posterior elements. In Hangman's fractures Type II and IIA with severe vertebral body and pedicle displacement, NSA technique is an effective and reliable treatment alternative for the approximation of posterior elements to the C2 vertebral body, which is tilted, angulated, and dislocated.

  10. Magnetic Nondestructive Testing Techniques of Constructional Steel

    Directory of Open Access Journals (Sweden)

    Xiong Er-gang

    2016-01-01

    Full Text Available Steel is a kind of ferromagnetic material, which is extensively applied in such fields as buildings, bridges, railways, machines and lifeline engineering etc. Those engineering structures built of constructional steel will unavoidably experience some damages during their service lifetime, thus which will influence the distribution regularity of internal forces in structures, result in over-stresses, cause the local failure of structures, and even lead to collapse of the whole structure. Therefore, it is a pressing topic to study how to directly evaluate the real-time stressed states of structural members, damages and steel characteristics in present structural health monitoring and diagnosing fields. And the achievements of this research will be of theoretical significance and of application value of engineering. This paper summarizes varieties of new magnetic nondestructive testing techniques used in constructional steel, respectively investigates the testing principles, characteristics and application for the magnetic Barkhausen noise technique, magnetic acoustic emission technique, magnetic flux leakage technique, magnetic memory technique and magnetic absorption technique, and points out the problems present in the application of these new techniques to actual testing and the further research objective.

  11. Computer Assisted Audit Techniques

    Directory of Open Access Journals (Sweden)

    Eugenia Iancu

    2007-01-01

    Full Text Available From the modern point of view, audit takes intoaccount especially the information systems representingmainly the examination performed by a professional asregards the manner for developing an activity by means ofcomparing it to the quality criteria specific to this activity.Having as reference point this very general definition ofauditing, it must be emphasized that the best known segmentof auditing is the financial audit that had a parallel evolutionto the accountancy one.The present day phase of developing the financial audithas as main trait the internationalization of the accountantprofessional. World wide there are multinational companiesthat offer services in the financial auditing, taxing andconsultancy domain. The auditors, natural persons and auditcompanies, take part at the works of the national andinternational authorities for setting out norms in theaccountancy and auditing domain.The computer assisted audit techniques can be classified inseveral manners according to the approaches used by theauditor. The most well-known techniques are comprised inthe following categories: testing data techniques, integratedtest, parallel simulation, revising the program logics,programs developed upon request, generalized auditsoftware, utility programs and expert systems.

  12. Fundamentals - state of the art of radiation techniques

    International Nuclear Information System (INIS)

    Wogman, N.A.

    1982-01-01

    In minerals exploration and extraction, nuclear techniques have several advantages. The techniques are elementally specific and their exploration range varies from a few millimeters in average rock formations to more than a meter. Because of the heterogeneous disposition of minerals and difficult environments in which measurements are required (in boreholes, on conveyor belts, in bunkers), interrogating techniques are required which exhibit both elemental specificity and range. It is for these fundamental reasons that nuclear techniques are the only possible techniques which satisfy all requirements. A variety of techniques have been developed and used. These are based on energy dispersive x-ray fluorescence (EDXRF), measurement of natural gamma-ray radiation, gamma-ray attenuation and scattering, and on neutron interactions. This paper discusses the fundamentals of these four techniques and their applications. A table is also provided listing some existing selected applications of nuclear techniques in mineral exploration, mining and processing

  13. Overview of nonchemical decontamination techniques

    International Nuclear Information System (INIS)

    Allen, R.P.

    1984-09-01

    The decontamination techniques summarized in this paper represent a variety of surface cleaning methods developed or adapted for component and facility-type decontamination applications ranging from small hand tools to reactor cavities and other large surface areas. The major conclusion is that decontamination is a complex, demanding technical discipline. It requires knowledgeable, experienced and well-trained personnel to select proper techniques and combinations of techniques for the varied plant applications and to realize their full performance potential. Unfortunately, decontamination in many plants has the lowest priority of almost any activity. Operators are unskilled and turnover is so frequent that expensive decontamination capabilities remain unused while decontamination operations revert to the most rudimentary type of hand scrubbing and water spray cleaning

  14. Radon survey techniques

    International Nuclear Information System (INIS)

    Anon.

    1976-01-01

    The report reviews radon measurement surveys in soils and in water. Special applications, and advantages and limitations of the radon measurement techniques are considered. The working group also gives some directions for further research in this field

  15. An anonymization technique using intersected decision trees

    Directory of Open Access Journals (Sweden)

    Sam Fletcher

    2015-07-01

    Full Text Available Data mining plays an important role in analyzing the massive amount of data collected in today’s world. However, due to the public’s rising awareness of privacy and lack of trust in organizations, suitable Privacy Preserving Data Mining (PPDM techniques have become vital. A PPDM technique provides individual privacy while allowing useful data mining. We present a novel noise addition technique called Forest Framework, two novel data quality evaluation techniques called EDUDS and EDUSC, and a security evaluation technique called SERS. Forest Framework builds a decision forest from a dataset and preserves all the patterns (logic rules of the forest while adding noise to the dataset. We compare Forest Framework to its predecessor, Framework, and another established technique, GADP. Our comparison is done using our three evaluation criteria, as well as Prediction Accuracy. Our experimental results demonstrate the success of our proposed extensions to Framework and the usefulness of our evaluation criteria.

  16. [Single procedure treatment of complex nephrolithiasis: about a modern series of anatrophic nephrolithotomy].

    Science.gov (United States)

    Lunardi, P; Timsit, M O; Roumiguie, M; Dariane, C; N'Guyen, K; Beauval, J B; Leroux, S

    2015-02-01

    Advances in endourology have significantly reduced indications of open surgery in the treatment of staghorn calculi. However, in our experience, open surgery is still the treatment of choice in some cases. This study presents the results of a series of selected patients and discusses the results in terms of efficacy and morbidity. A cohort of 26 patients underwent anatrophic nephrolithotomy by lombotomy to treat a complex staghorn calculus. The mean stone size was 68,5mm, 70% were complete staghorn calculi. The operative time was 100minutes. Blood loss was 225mL, with a postoperative transfusion rate of 15.4%. The hospital stay was 8.4 days. The stone free rate following the procedure was 92%. The creatinine clearance (MDRD) at 3 months was improved from 5.9mL/min/m(2) on average over the entire series. There are clearly still indications for open surgery in staghorn stones management, with good results in this contemporary series on both stone removal and nephronic preservation. Yet, it appears that this technique is no longer taught. 5. Copyright © 2014 Elsevier Masson SAS. All rights reserved.

  17. [Intestinal lengthening techniques: an experimental model in dogs].

    Science.gov (United States)

    Garibay González, Francisco; Díaz Martínez, Daniel Alberto; Valencia Flores, Alejandro; González Hernández, Miguel Angel

    2005-01-01

    To compare two intestinal lengthening procedures in an experimental dog model. Intestinal lengthening is one of the methods for gastrointestinal reconstruction used for treatment of short bowel syndrome. The modification to the Bianchi's technique is an alternative. The modified technique decreases the number of anastomoses to a single one, thus reducing the risk of leaks and strictures. To our knowledge there is not any clinical or experimental report that studied both techniques, so we realized the present report. Twelve creole dogs were operated with the Bianchi technique for intestinal lengthening (group A) and other 12 creole dogs from the same race and weight were operated by the modified technique (Group B). Both groups were compared in relation to operating time, difficulties in technique, cost, intestinal lengthening and anastomoses diameter. There were no statistical difference in the anastomoses diameter (A = 9.0 mm vs. B = 8.5 mm, p = 0.3846). Operating time (142 min vs. 63 min) cost and technique difficulties were lower in group B (p anastomoses (of Group B) and intestinal segments had good blood supply and were patent along their full length. Bianchi technique and the modified technique offer two good reliable alternatives for the treatment of short bowel syndrome. The modified technique improved operating time, cost and technical issues.

  18. Magnetic field measurements and mapping techniques

    CERN Multimedia

    CERN. Geneva

    2003-01-01

    These lectures will present an overview of the most common techniques used for the measurement of magnetic field in accelerator magnets. The formalism for a harmonic description of the magnetic field will be presented, including a discussion of harmonics allowed under various types of symmetries in the magnet. The harmonic coil technique for measurement of field harmonics will be covered in depth. Using examples from recent projects, magnetic measurements will be shown to be a powerful tool for monitoring magnet production. Measurements of magnetic axis using extensions of the harmonic coil technique, as well as other techniques, such as the colloidal cell and stretched wire, will be covered. Topics of interest in superconducting magnets, such as time decay and snapback, requiring relatively fast measurements of the harmonics, will also be described.

  19. Soft computing techniques in engineering applications

    CERN Document Server

    Zhong, Baojiang

    2014-01-01

    The Soft Computing techniques, which are based on the information processing of biological systems are now massively used in the area of pattern recognition, making prediction & planning, as well as acting on the environment. Ideally speaking, soft computing is not a subject of homogeneous concepts and techniques; rather, it is an amalgamation of distinct methods that confirms to its guiding principle. At present, the main aim of soft computing is to exploit the tolerance for imprecision and uncertainty to achieve tractability, robustness and low solutions cost. The principal constituents of soft computing techniques are probabilistic reasoning, fuzzy logic, neuro-computing, genetic algorithms, belief networks, chaotic systems, as well as learning theory. This book covers contributions from various authors to demonstrate the use of soft computing techniques in various applications of engineering.  

  20. Integral transform techniques for Green's function

    CERN Document Server

    Watanabe, Kazumi

    2015-01-01

    This book describes mathematical techniques for integral transforms in a detailed but concise manner. The techniques are subsequently applied to the standard partial differential equations, such as the Laplace equation, the wave equation and elasticity equations. Green’s functions for beams, plates and acoustic media are also shown, along with their mathematical derivations. The Cagniard-de Hoop method for double inversion is described in detail, and 2D and 3D elastodynamic problems are treated in full. This new edition explains in detail how to introduce the branch cut for the multi-valued square root function. Further, an exact closed form Green’s function for torsional waves is presented, as well as an application technique of the complex integral, which includes the square root function and an application technique of the complex integral.

  1. New techniques for wound debridement.

    Science.gov (United States)

    Madhok, Brijesh M; Vowden, Kathryn; Vowden, Peter

    2013-06-01

    Debridement is a crucial component of wound management. Traditionally, several types of wound debridement techniques have been used in clinical practice such as autolytic, enzymatic, biodebridement, mechanical, conservative sharp and surgical. Various factors determine the method of choice for debridement for a particular wound such as suitability to the patient, the type of wound, its anatomical location and the extent of debridement required. Recently developed products are beginning to challenge traditional techniques that are currently used in wound bed preparation. The purpose of this review was to critically evaluate the current evidence behind the use of these newer techniques in clinical practice. There is some evidence to suggest that low frequency ultrasound therapy may improve healing rates in patients with venous ulcers and diabetic foot ulcers. Hydrosurgery debridement is quick and precise, but the current evidence is limited and further studies are underway. Debridement using a monofilament polyester fibre pad and plasma-mediated bipolar radiofrequency ablation are both very new techniques. The initial evidence is limited, and further studies are warranted to confirm their role in management of chronic wounds. © 2013 The Authors. International Wound Journal © 2013 John Wiley & Sons Ltd and Medicalhelplines.com Inc.

  2. A study of renal blood flow regulation using the discrete wavelet transform

    Science.gov (United States)

    Pavlov, Alexey N.; Pavlova, Olga N.; Mosekilde, Erik; Sosnovtseva, Olga V.

    2010-02-01

    In this paper we provide a way to distinguish features of renal blood flow autoregulation mechanisms in normotensive and hypertensive rats based on the discrete wavelet transform. Using the variability of the wavelet coefficients we show distinctions that occur between the normal and pathological states. A reduction of this variability in hypertension is observed on the microscopic level of the blood flow in efferent arteriole of single nephrons. This reduction is probably associated with higher flexibility of healthy cardiovascular system.

  3. A Case of Synchronous Bilateral Upper Urinary System Urothelial Carcinoma

    Directory of Open Access Journals (Sweden)

    Ibrahim Buldu

    2014-12-01

    Full Text Available Synchronous bilateral upper urinary tract urothelial cancer (UTUC is a very rare form of urothelial cancer. In patients with high-risk unilateral UTUC, radical nephroureterectomy (RNU is the gold standard treatment. However, there is no consensus on the treatment for synchronous bilateral UTUC. Evaluation of the patient and the tumor is recommended. Bilateral nephron-sparing surgery (NSS was performed on a 53-year-old patient who presented with high-risk synchronous bilateral UTUC, and the outcome was reported.

  4. Dosimetric comparison of field in field intensity-modulated radiotherapy technique with conformal radiotherapy techniques in breast cancer

    International Nuclear Information System (INIS)

    Ercan, T.; Alco, G.; Zengin, F.; Atilla, S.; Dincer, M.; Igdem, S.; Okkan, S.

    2010-01-01

    The aim of this study was to be able to implement the field-in-field intensity-modulated radiotherapy (FiF) technique in our daily practice for breast radiotherapy. To do this, we performed a dosimetric comparison. Treatment plans were produced for 20 consecutive patients. FiF plans and conformal radiotherapy (CRT) plans were compared for doses in the planning target volume (PTV), the dose homogeneity index (DHI), doses in irradiated soft tissue outside the target volume (SST), ipsilateral lung and heart doses for left breast irradiation, and the monitor unit counts (MU) required for treatment. Averaged values were compared using Student's t-test. With FiF, the DHI is improved 7.0% and 5.7%, respectively (P<0.0001) over the bilateral and lateral wedge CRT techniques. When the targeted volumes received 105% and 110% of the prescribed dose in the PTV were compared, significant decreases are found with the FiF technique. With the 105% dose, the SST, heart, and ipsilateral lung doses and the MU counts were also significantly lower with the FiF technique. The FiF technique, compared to CRT, for breast radiotherapy enables significantly better dose distribution in the PTV. Significant differences are also found for soft tissue volume, the ipsilateral lung dose, and the heart dose. Considering the decreased MUs needed for treatment, the FiF technique is preferred over tangential CRT. (author)

  5. Advanced Techniques in Biophysics

    CERN Document Server

    Arrondo, José Luis R

    2006-01-01

    Technical advancements are basic elements in our life. In biophysical studies, new applications and improvements in well-established techniques are being implemented every day. This book deals with advancements produced not only from a technical point of view, but also from new approaches that are being taken in the study of biophysical samples, such as nanotechniques or single-cell measurements. This book constitutes a privileged observatory for reviewing novel applications of biophysical techniques that can help the reader enter an area where the technology is progressing quickly and where a comprehensive explanation is not always to be found.

  6. Nonenhanced MR angiography techniques

    International Nuclear Information System (INIS)

    Lanzman, R.S.; Kroepil, P.; Blondin, D.; Schmitt, P.

    2011-01-01

    Especially in regard to the potential risks for the development of nephrogenic systemic fibrosis (NSF) following the administration of Gadolinium-based contrast material, nonenhanced MR angiography (MRA) methods are becoming ever more important. Besides well-established time-of-flight (TOF) and phase-contrast (PC) MRA, alternative imaging techniques based on balanced steady-state free precession (bSSFP) and turbo-spin-echo (TSE) sequences are increasingly used in combination with or without arterial spin labeling (ASL) strategies. This article provides an overview of the principles and clinical values of different nonenhanced MRA techniques. In addition, recent nonenhanced MRA developments are presented. (orig.)

  7. Materials Science and X-ray Techniques

    International Nuclear Information System (INIS)

    Brock, J.; Sutton, M.

    2008-01-01

    Many novel synchrotron-based X-ray techniques directly address the core questions of modern materials science but are not yet at the stage of being easy to use because of the lack of dedicated beamlines optimized for specific measurements. In this article, we highlight a few of these X-ray techniques and discuss why, with ongoing upgrades of existing synchrotrons and with new linear-accelerator-based sources under development, now is the time to ensure that these techniques are readily available to the larger materials research community.

  8. Alternative Assessment Techniques.

    Science.gov (United States)

    Lowenthal, Barbara

    1988-01-01

    Maintaining the precision necessary for administering norm referenced tests can be a problem for the special education teacher who is trained to assist the student. Criterion-referenced tests, observations, and interviews are presented as effective alternative assessment techniques. (JDD)

  9. Application of functional analysis techniques to supervisory systems

    International Nuclear Information System (INIS)

    Lambert, Manuel; Riera, Bernard; Martel, Gregory

    1999-01-01

    The aim of this paper is to apply firstly two interesting functional analysis techniques for the design of supervisory systems for complex processes, and secondly to discuss the strength and the weaknesses of each of them. Two functional analysis techniques have been applied, SADT (Structured Analysis and Design Technique) and FAST (Functional Analysis System Technique) on a process, an example of a Water Supply Process Control (WSPC) system. These techniques allow a functional description of industrial processes. The paper briefly discusses the functions of a supervisory system and some advantages of the application of functional analysis for the design of a 'human' centered supervisory system. Then the basic principles of the two techniques applied on the WSPC system are presented. Finally, the different results obtained from the two techniques are discussed

  10. The Random-Map Technique: Enhancing Mind-Mapping with a Conceptual Combination Technique to Foster Creative Potential

    Science.gov (United States)

    Malycha, Charlotte P.; Maier, Günter W.

    2017-01-01

    Although creativity techniques are highly recommended in working environments, their effects have been scarcely investigated. Two cognitive processes are often considered to foster creative potential and are, therefore, taken as a basis for creativity techniques: knowledge activation and conceptual combination. In this study, both processes were…

  11. Soil analysis. Modern instrumental technique

    International Nuclear Information System (INIS)

    Smith, K.A.

    1993-01-01

    This book covers traditional methods of analysis and specialist monographs on individual instrumental techniques, which are usually not written with soil or plant analysis specifically in mind. The principles of the techniques are combined with discussions of sample preparation and matrix problems, and critical reviews of applications in soil science and related disciplines. Individual chapters are processed separately for inclusion in the appropriate data bases

  12. The OPPIuM technique: office hysteroscopic technique for the preparation of partially intramural leiomyomas.

    Science.gov (United States)

    Cicinelli, Ettore; Mitsopoulos, Vasileios; Fascilla, Fabiana D; Sioutis, Dimos; Bettocchi, Stefano

    2016-06-01

    Uterine fibroids, also known as leiomyomas, represent the most common benign tumors of the female genital tract. Submucosal leiomyomas are classified into three grades: G0, GI, GII according to the degree of their intramural proportion. A recently developed technique enables the preparation of G1 and G2 leiomyomas for their subsequent successful resection in a second step. The OPPIuM (office preparation of partially intramural leiomyomas) technique aims to downgrade type I and II leiomyomas, in order to facilitate a subsequent easier and safer resectoscopy. Hysteroscopic resection of large GI or GII submucosal fibroids is a complex procedure. OPPIuM technique has been invented and seems to achieve the downgrading of these types of leiomyomas in approximately 93% of cases, without any significant surgical complications or the need of hormonal agents' administration. In this way, the safer and quicker subsequent complete myomectomy is facilitated.

  13. Vasectomy occlusion techniques for male sterilization.

    Science.gov (United States)

    Cook, L A; Vliet, H; Pun, A; Gallo, M F

    2004-01-01

    Vasectomy is an increasingly popular and effective family planning method. A variety of vasectomy techniques are used worldwide including various vas occlusion techniques (excision and ligation, thermal or electrocautery, and mechanical and chemical occlusion methods), vas irrigation and fascial interposition. Vasectomy guidelines largely rely on information from observational studies. Ideally, the choice of vasectomy techniques should be based on the best available evidence from randomized controlled trials. The objective of this review was to compare the effectiveness, safety, acceptability and costs of vasectomy techniques for male sterilization. We searched the computerized databases the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, EMBASE, Popline and LILACS. In addition, we searched the reference lists of relevant articles and book chapters. We included randomized controlled trials and controlled clinical trials comparing vasectomy techniques. We assessed all titles and abstracts located in the literature searches and two reviewers independently extracted articles identified for inclusion. Data were presented in the text of the review. Outcome measures include contraceptive efficacy, safety, discontinuation, and acceptability. Two trials compared vas occlusion with clips versus a conventional vasectomy technique; both were of poor quality. Neither trial found a difference between the two groups with regard to the primary outcome of failure to reach azoospermia. Four trials examined vas irrigation: three compared water irrigation with no irrigation and one compared water irrigation with euflavine. All of the trials were of poor quality. None of the trials found a significant difference between the groups with respect to the primary outcome of time to azoospermia. However, one trial found that the median number of ejaculations to azoospermia was significantly lower in the euflavine group compared to the water irrigation group. The one trial

  14. Seminar on Detectors and measurements techniques

    Energy Technology Data Exchange (ETDEWEB)

    Holm, E. (ed.) [Risoe National Lab., Roskilde (Denmark)

    2002-07-01

    A Nordic Seminar on detectors and radionuclide measurement techniques was held in Lund, Sweden, May 3-4, 2001. The objective was to highlight recent progress and problems for techniques to study environmental radioactivity. It covered the aspect of detector sample geometry's and methods for evaluation of gamma gamma pulse height distributions. Within the field of alpha-spectrometric techniques gridded ionisation chambers, semiconductor detectors and a general description for analysis of alpha-particle-spectra were presented. Recent development in mass spectrometric techniques, AMS (Accelerator Mass Spectrometry) and ICPMS (Inductively Coupled Plasma mass Spectrometry) for long-lived radionuclides was described. Principles for analysis of beta particle emitters, especially by liquid scintillation were presented. The seminar also covered radiochemistry such advantages and disadvantages between ion exchange, solvent extraction and extraction chromatography. The use of controlled laboratory conditions for discerning the dynamics of accumulation in organisms was demonstrated. Other techniques such as neutron activation were also shown to be useful analytical tool for certain long-lived radionuclides. The results of the intercalibration exercises within the Nordic countries showed the importance of such analytical quality control. (au)

  15. New computing techniques in physics research

    International Nuclear Information System (INIS)

    Becks, Karl-Heinz; Perret-Gallix, Denis

    1994-01-01

    New techniques were highlighted by the ''Third International Workshop on Software Engineering, Artificial Intelligence and Expert Systems for High Energy and Nuclear Physics'' in Oberammergau, Bavaria, Germany, from October 4 to 8. It was the third workshop in the series; the first was held in Lyon in 1990 and the second at France-Telecom site near La Londe les Maures in 1992. This series of workshops covers a broad spectrum of problems. New, highly sophisticated experiments demand new techniques in computing, in hardware as well as in software. Software Engineering Techniques could in principle satisfy the needs for forthcoming accelerator experiments. The growing complexity of detector systems demands new techniques in experimental error diagnosis and repair suggestions; Expert Systems seem to offer a way of assisting the experimental crew during data-taking

  16. Artificial intelligence techniques in power systems

    Energy Technology Data Exchange (ETDEWEB)

    Laughton, M.A.

    1997-12-31

    Since the early to mid 1980s much of the effort in power systems analysis has turned away from the methodology of formal mathematical modelling which came from the fields of operations research, control theory and numerical analysis to the less rigorous techniques of artificial intelligence (AI). Today the main AI techniques found in power systems applications are those utilising the logic and knowledge representations of expert systems, fuzzy systems, artificial neural networks (ANN) and, more recently, evolutionary computing. These techniques will be outlined in this chapter and the power system applications indicated. (Author)

  17. New CT-aided stereotactic neurosurgery technique

    International Nuclear Information System (INIS)

    Shao, H.M.; Truong, T.K.; Reed, I.S.; Slater, R.A.

    1985-01-01

    In this communication, a new technique for CT-aided stereotactic neurosurgery is presented. The combination of specially designed hardware and software provides a fast, simple, and versatile tool for the accurate insertion of a probe into the human brain. This system is portable and can be implemented on any CT computer system. The complete procedure to perform the CT-aided stereotactic neurosurgery technique is presented. Experimental results are given which demonstrate the power of the method. Finally, the key algorithms for realizing this technique are described in the Appendix

  18. GPU PRO 3 Advanced rendering techniques

    CERN Document Server

    Engel, Wolfgang

    2012-01-01

    GPU Pro3, the third volume in the GPU Pro book series, offers practical tips and techniques for creating real-time graphics that are useful to beginners and seasoned game and graphics programmers alike. Section editors Wolfgang Engel, Christopher Oat, Carsten Dachsbacher, Wessam Bahnassi, and Sebastien St-Laurent have once again brought together a high-quality collection of cutting-edge techniques for advanced GPU programming. With contributions by more than 50 experts, GPU Pro3: Advanced Rendering Techniques covers battle-tested tips and tricks for creating interesting geometry, realistic sha

  19. Design techniques for mutlivariable flight control systems

    Science.gov (United States)

    1981-01-01

    Techniques which address the multi-input closely coupled nature of advanced flight control applications and digital implementation issues are described and illustrated through flight control examples. The techniques described seek to exploit the advantages of traditional techniques in treating conventional feedback control design specifications and the simplicity of modern approaches for multivariable control system design.

  20. A simplified technique for shakedown load determination

    International Nuclear Information System (INIS)

    Abdalla, H.F.; Younan, M.Y.A.; Megahed, M.M.

    2005-01-01

    In this paper a simple technique is presented to determine the limit shakedown load of a structure or a component using the finite element method. Through the proposed technique, the limit shakedown load is determined without performing time consuming cyclic loading simulations or iterative elastic techniques. Instead, it is determined by performing only two analyses namely, an elastic analysis and an elastic-plastic analysis. By extracting the results of the two analyses, the limit shakedown load of the structure is determined through the calculation of the residual stresses. The technique is applied and verified using two bench mark shakedown problems namely: the two-bar structure subjected to constant axial force and cyclic thermal loading, and the Bree cylinder subjected to constant internal pressure and cyclic high heat fluxes across its wall. The results of the proposed technique showed very good correlation with the, analytically determined, Bree diagrams of both structures. Moreover, the outcomes of the proposed technique showed very good results in comparison to full cyclic loading elasto-plastic finite element simulations of both structures. (authors)