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Journal of Nuclear Medicine Technology Dec 2019Pyelonephritis is an infection of the kidneys that is seen more commonly in children than the adults. Tc-dimercaptosuccinic acid (Tc-DMSA) scanning is a radionuclide... (Review)
Review
Pyelonephritis is an infection of the kidneys that is seen more commonly in children than the adults. Tc-dimercaptosuccinic acid (Tc-DMSA) scanning is a radionuclide imaging study to detect renal scarring after acute pyelonephritis (a late Tc-DMSA scan) and also helps to diagnose acute pyelonephritis in febrile urinary tract infections (an acute Tc-DMSA scan). Planar imaging in multiple views (posterior and bilateral posterior oblique) is generally used. Pinhole imaging with a high-resolution-collimator magnification of each kidney allows detection of smaller cortical defects. SPECT is optional. SPECT/CT is not recommended in children because it has a higher radiation exposure than routine Tc-DMSA scans. The main limitations of Tc-DMSA scanning include a relatively long waiting time after radiotracer injection, a long acquisition time, and a high radiation dose, which is particularly important in repeated studies on children and with the limited spatial resolution of γ-cameras. Tc-glucoheptonate is an alternative radiotracer when Tc-DMSA is not available. Radiotracers for dynamic renal functional imaging can grossly assess the renal cortex in the first few minutes of imaging. Ga-prostate-specific membrane antigen ligand (Ga-PSMA ligand) PET has the ability to provide images of normal renal cortex and demonstrate renal cortical defects from cysts. In this article, we assess the current status of renal cortical imaging and present Ga-PSMA ligand PET images. Ga-PSMA ligand provides excellent renal cortical images, and studies should be done to compare Ga-PSMA ligand PET with Tc-DMSA scanning in renal diseases, particularly in pyelonephritis.
Topics: Diagnostic Imaging; Humans; Kidney Cortex; Pyelonephritis; Radioactive Tracers
PubMed: 31182659
DOI: 10.2967/jnmt.119.227942 -
Frontiers in Endocrinology 2020Diabetic kidney disease (DKD) is a prevalent and progressive comorbidity of diabetes mellitus that increases one's risk of developing renal failure. Progress toward... (Review)
Review
Diabetic kidney disease (DKD) is a prevalent and progressive comorbidity of diabetes mellitus that increases one's risk of developing renal failure. Progress toward development of better DKD therapeutics is limited by an incomplete understanding of forces driving and connecting the various features of DKD, which include renal steatosis, fibrosis, and microvascular dysfunction. Herein we review the literature supporting roles for bioactive ceramides as inducers of local and systemic DKD pathology. In rodent models of DKD, renal ceramides are elevated, and genetic and pharmacological ceramide-lowering interventions improve kidney function and ameliorate DKD histopathology. In humans, circulating sphingolipid profiles distinguish human DKD patients from diabetic controls. These studies highlight the potential for ceramide to serve as a central and therapeutically tractable lipid mediator of DKD.
Topics: Animals; Ceramides; Diabetes Mellitus, Type 2; Diabetic Nephropathies; Humans; Insulin Resistance; Kidney Cortex; Sphingolipids
PubMed: 33584550
DOI: 10.3389/fendo.2020.622692 -
American Journal of Physiology.... Nov 2019Human studies of renal hemodynamics and metabolism in obesity are insufficient. We hypothesized that renal perfusion and renal free fatty acid (FFA) uptake are higher in...
Human studies of renal hemodynamics and metabolism in obesity are insufficient. We hypothesized that renal perfusion and renal free fatty acid (FFA) uptake are higher in subjects with morbid obesity compared with lean subjects and that they both decrease after bariatric surgery. Cortical and medullary hemodynamics and metabolism were measured in 23 morbidly obese women and 15 age- and sex-matched nonobese controls by PET scanning of [O]-HO (perfusion) and 14()-[F]fluoro-6-thia-heptadecanoate (FFA uptake). Kidney volume and radiodensity were measured by computed tomography, cardiac output by MRI. Obese subjects were re-studied 6 mo after bariatric surgery. Obese subjects had higher renal volume but lower radiodensity, suggesting accumulation of water and/or lipid. Both cardiac output and estimated glomerular filtration rate (eGFR) were increased by ~25% in the obese. Total renal blood flow was higher in the obese [885 (317) (expressed as median and interquartile range) vs. 749 (300) (expressed as means and SD) ml/min of controls, = 0.049]. In both groups, regional blood perfusion was higher in the cortex than medulla; in either region, FFA uptake was ~50% higher in the obese as a consequence of higher circulating FFA levels. Following weight loss (26 ± 8 kg), total renal blood flow was reduced ( = 0.006). Renal volume, eGFR, cortical and medullary FFA uptake were decreased but not fully normalized. Obesity is associated with renal structural, hemodynamic, and metabolic changes. Six months after bariatric surgery, the hemodynamic changes are reversed and the structural changes are improved. On the contrary, renal FFA uptake remains increased, driven by high substrate availability.
Topics: Adult; Bariatric Surgery; Fatty Acids; Female; Glomerular Filtration Rate; Hemodynamics; Humans; Kidney; Kidney Cortex; Kidney Medulla; Magnetic Resonance Imaging; Middle Aged; Obesity, Morbid; Renal Circulation; Tomography, X-Ray Computed; Weight Loss
PubMed: 31550182
DOI: 10.1152/ajpendo.00135.2019 -
Kidney International Feb 1997
Review
Topics: Animals; Humans; Hypoxia; Kidney; Kidney Cortex; Kidney Medulla; Magnetic Resonance Imaging; Oxygen Consumption; Rats
PubMed: 9027710
DOI: 10.1038/ki.1997.50 -
Acta Physiologica (Oxford, England) Sep 2019Disturbances of renal medullary perfusion and metabolism have been implicated in the pathogenesis of kidney disease and hypertension. Furosemide, a loop diuretic, is...
AIM
Disturbances of renal medullary perfusion and metabolism have been implicated in the pathogenesis of kidney disease and hypertension. Furosemide, a loop diuretic, is widely used to prevent renal medullary hypoxia in acute kidney disease by uncoupling sodium metabolism, but its effects on medullary perfusion in humans are unknown. We performed quantitative imaging of both renal perfusion and oxygenation using Magnetic Resonance Imaging (MRI) before and during furosemide. Based on the literature, we hypothesized that furosemide would increase medullary oxygenation, decrease medullary perfusion, but cause minor changes (<10%) in renal artery flow (RAF).
METHODS
Interleaved measurements of RAF, oxygenation (T *) and perfusion by arterial spin labelling in the renal cortex and medulla of 9 healthy subjects were acquired before and after an injection of 20 mg furosemide. They were preceded by measurements made during isometric exercise (5 minutes handgrip bouts), which are known to induce changes in renal hemodynamics, that served as a control for the sensitivity of the hemodynamic MRI measurements. Experiments were repeated on a second day to establish that the measurements and the induced changes were reproducible.
RESULTS
After furosemide, T * values in the medulla increased by 53% (P < 0.01) while RAF and perfusion remained constant. After hand-grip exercise, T * values in renal medulla increased by 22% ± 9% despite a drop in medullary perfusion of 7.2% ± 4.7% and a decrease in renal arterial flow of 17.5% ± 1.7% (P < 0.05). Mean coefficients of variation between repeated measurements for all parameters were 7%.
CONCLUSION
Furosemide induced the anticipated increase in renal medullary oxygenation, attributable exclusively to a decrease in renal oxygen consumption, since no change of RAF, cortical or medullary perfusion could be demonstrated. All measures and the induced changes were reproducible.
Topics: Adult; Diuretics; Female; Furosemide; Humans; Kidney Cortex; Kidney Medulla; Male; Middle Aged; Oxygen Consumption; Young Adult
PubMed: 31046189
DOI: 10.1111/apha.13292 -
Journal of Veterinary Science Jul 2020Quantitative evaluation of renal cortical echogenicity (RCE) has been tried and developed in human and veterinary medicine.
BACKGROUND
Quantitative evaluation of renal cortical echogenicity (RCE) has been tried and developed in human and veterinary medicine.
OBJECTIVES
The objective of this study was to propose a method for evaluating RCE quantitatively and intuitively, and to determine associations between ultrasonographic renal structural distinction and estimated glomerular filtration rate (eGFR) in canine chronic kidney disease (CKD).
METHODS
Data were collected on 63 dogs, including 27 with normal kidney function and 36 CKD patients. Symmetric dimethylarginine and creatinine concentrations were measured for calculating eGFR. RCE was evaluated as 3 grades on ultrasonography images according to the distinction between the renal cortex and outer medulla. The RCE grade of each kidney was measured.
RESULTS
There was a significant difference in eGFR between the group normal and CKD ( < 0.001). As mean of RCE grades (the mean values of each right and left kidney's RCE grade) increases, the proportion of group CKD among the patients in each grade increases ( < 0.001). Also, severity of RCE (classified as "high" if any right or left kidney evaluated as RCE grade 3, "low" otherwise) and eGFR is good indicator for predicting group CKD ( < 0.001).
CONCLUSIONS
The degree of distinction between the renal cortex and the outer medulla is closely related to renal function including eGFR and the RCE grade defined in this study can be used as a method of objectively evaluating RCE.
Topics: Animals; Dog Diseases; Dogs; Glomerular Filtration Rate; Kidney Cortex; Kidney Medulla; Renal Insufficiency, Chronic; Ultrasonography
PubMed: 32735096
DOI: 10.4142/jvs.2020.21.e58 -
Histochemistry and Cell Biology Aug 2008The renal interstitial compartment, situated between basement membranes of epithelia and vessels, contains two contiguous cellular networks. One network is formed by... (Review)
Review
The renal interstitial compartment, situated between basement membranes of epithelia and vessels, contains two contiguous cellular networks. One network is formed by interstitial fibroblasts, the second one by dendritic cells. Both are in intimate contact with each other. Fibroblasts are interconnected by junctions and connected to basement membranes of vessels and tubules by focal adhesions. Fibroblasts constitute the "skeleton" of the kidney. In the renal cortex, fibroblasts produce erythropoietin and are distinguished from other interstitial cells by their prominent F-actin cytoskeleton, abundance of rough endoplasmic reticulum, and by ecto-5'-nucleotidase expression in their plasma membrane. The resident dendritic cells belong to the mononuclear phagocyte system and fulfil a sentinel function. They are characterized by their expression of MHC class II and CD11c. The central situation of fibroblasts suggests that signals from tubules, vessels, and inflammatory cells converge in fibroblasts and elicit an integrated response. Following tubular damage and inflammatory signals fibroblasts proliferate, change to the myofibroblast phenotype and increase their collagen production, potentially resulting in renal fibrosis. The acquisition of a profibrotic phenotype by fibroblasts in renal diseases is generally considered a main causal event in the progression of chronic renal failure. However, it might also be seen as a repair process.
Topics: 5'-Nucleotidase; Actins; Animals; Dendritic Cells; Erythropoietin; Fibroblasts; Fibrosis; Humans; Kidney Cortex; Kidney Failure, Chronic; Mice; Nephritis, Interstitial
PubMed: 18575881
DOI: 10.1007/s00418-008-0452-5 -
Life Sciences Aug 2020To evaluate the effects of esculin treatment on P2X7 receptor and mitochondrial dysfunction in the renal cortex of diabetic rats.
AIMS
To evaluate the effects of esculin treatment on P2X7 receptor and mitochondrial dysfunction in the renal cortex of diabetic rats.
MAIN METHODS
Male Wistar rats, 7 weeks old, were unilaterally nephrectomized. Part of these animals were induced to diabetes using streptozotocin (60 mg/kg). Diabetes was confirmed 48 h after induction, with blood glucose levels ≥200 mg/dL. Part of control and diabetic animals were selected to receive daily doses of esculin (50 mg/kg), during 8 weeks. The animals were placed in metabolic cages at the eighth week of protocol for 24 h urine collection and a small aliquot of blood was collected for biochemical analysis. After this procedure, the animals were euthanized and the remaining kidney was stored for histopathological analysis, Western blotting and mitochondrial high-resolution respirometry.
KEY FINDINGS
Although esculin did not change metabolic parameters, renal biochemical function, neither TBARS in DM rats, esculin reduced P2X7 levels in these animals and restored mitochondrial function via glycolysis substrates and β-oxidation. Besides, at the histological analysis, we observed that esculin reduced inflammatory infiltrates and collagen IV deposits as compared to diabetic group.
SIGNIFICANCE
Esculin attenuated the development of renal injuries caused by hyperglycemia, proinflammatory and oxidative mechanisms mediated by P2X7 receptor, as seen by histological findings and improved mitochondrial function in diabetic animals. This suggests that esculin could be used as an adjuvant therapy to prevent the diabetic nephropathy.
Topics: Animals; Blood Glucose; Diabetes Mellitus, Experimental; Esculin; Fibrillar Collagens; Glycolysis; Inflammation; Kidney Cortex; Male; Mitochondria; Oxidation-Reduction; Rats; Receptors, Purinergic P2X7; Thiobarbituric Acid Reactive Substances
PubMed: 32417372
DOI: 10.1016/j.lfs.2020.117787 -
PloS One 2012TRPC6, a member of the TRPC family, attracts much attention from the public because of its relationship with the disease. In both the brain and kidney, TRPC6 serves a...
TRPC6, a member of the TRPC family, attracts much attention from the public because of its relationship with the disease. In both the brain and kidney, TRPC6 serves a variety of functions. The aim of the present study was to observe the expression and effects of TRPC6 in renal cortex and hippocampus during early postnatal development of the mouse. In the present study, immunohistochemistry and Western blotting were used to detect the expression of TRPC6 in the mouse kidney and hippocampus of postnatal day 1, 3, 5, 7, 14, 21, 28 and 49 (P1, P3, P5, P7, P14, P21, P28 and P49). Results showed that the expression of TRPC6 was increased in the mouse hippocampus, and there was a significant increase between P7 and P14 during the postnatal development. Meanwhile, the expression of TRPC6 was also detected in glomerulus and tubules, and a decreased expression was found during postnatal maturation of mouse renal cortex. From these in vivo experiments, we concluded that the expression of TRPC6 was active in the developing mouse kidney cortex, and followed a loss of expression with the development of kidney. Meanwhile, an increased expression was found in the hippocampus with the development. Together, these data suggested that the developmental changes in TRPC6 expression might be required for proper postnatal kidney cortex development, and played a critical role in the hippocampus during development, which formed the basis for understanding the nephrogenesis and neurogenesis in mice and provided a practically useful knowledge to the clinical and related research.
Topics: Age Factors; Analysis of Variance; Animals; Blotting, Western; Gene Expression Regulation, Developmental; Hippocampus; Immunohistochemistry; Kidney Cortex; Mice; TRPC Cation Channels; TRPC6 Cation Channel
PubMed: 22701654
DOI: 10.1371/journal.pone.0038503 -
International Urology and Nephrology Sep 2017Identifying the primary etiology of cardio-renal syndrome in a timely manner remains an ongoing challenge in nephrology. We hypothesized that hypertensive kidney damage...
PURPOSE
Identifying the primary etiology of cardio-renal syndrome in a timely manner remains an ongoing challenge in nephrology. We hypothesized that hypertensive kidney damage can be distinguished from chronic glomerulonephritis at an early stage of chronic kidney disease (CKD) using ultrasound (US) Doppler sonography.
METHODS
Fifty-six males (age 54 ± 15, BMI 28.3 ± 3.5 kg/m) with hypertension and stable CKD at stages 2-4 [38 with essential hypertension (HT-CKD); 18 with glomerulonephritis (GN-CKD)] were studied. Blood tests, UACR, echocardiography, ABPM, carotid IMT, and an ultrasound dynamic tissue perfusion measurement (DTPM) of the renal cortex were performed.
RESULTS
HT-CKD patients had reduced proximal renal cortex perfusion as well as reduced total and proximal renal cortex arterial area. Proximal renal cortex arterial area ≤0.149 cm identified hypertension-related CKD with a sensitivity of 71% and a specificity of 78% (AUC 0.753, p < 0.001).
CONCLUSIONS
Evidence of diminished arterial vascularity or perfusion of renal proximal cortex, both derived from US Doppler, could be helpful in differentiating hypertensive nephropathy from glomerulonephritis-related CKD.
Topics: Adult; Age Factors; Aged; Carotid Intima-Media Thickness; Echocardiography; Essential Hypertension; Glomerular Filtration Rate; Glomerulonephritis; Humans; Kidney Cortex; Male; Middle Aged; Natriuretic Peptide, Brain; Peptide Fragments; ROC Curve; Renal Circulation; Renal Insufficiency, Chronic; Stroke Volume; Troponin I; Ultrasonography, Doppler, Color
PubMed: 28573489
DOI: 10.1007/s11255-017-1634-7