Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0022672 (acute tubular necrosis)
 2,175 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Adenine nucleotides speed structural and functional recovery when administered after experimental renal injury in the rat and stimulate proliferation of kidney epithelial cells. As cell migration is a component of renal regeneration after acute tubular necrosis, we have used an in vitro model of wound healing to study this process. High density, quiescent monkey kidney epithelial cultures were wounded by mechanically scraping away defined regions of the monolayer to simulate the effect of cell loss after tubular necrosis and the number of cells that migrated into the denuded area was counted. Migration was independent of cell proliferation. Provision of adenosine, adenine nucleotides, or cyclic AMP increased the number of migrating cells and accelerated repair of the wound. Other purine and pyrimidine nucleotides were not effective. Arginine-glycine-aspartic acid-serine peptide, which blocks the binding of extracellular fibronectin to its cell surface receptor, completely inhibited migration in the presence or absence of ADP. Very low concentrations of epidermal growth factor (K0.5 approximately 0.3 ng/ml) stimulated migration, whereas transforming growth factor-beta 2 was inhibitory (Ki approximately 0.2 ng/ml). Thus, adenosine and/or adenine nucleotides released from injured or dying renal cells, or administered exogenously, may stimulate surviving cells in the wounded nephron to migrate along the basement membrane, thereby rapidly restoring tubular structure and function.
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PMID:Adenine nucleotides stimulate migration in wounded cultures of kidney epithelial cells. 163 17

Thirty-three consecutive cadaveric renal transplantations performed at the National Taiwan University Hospital from November 1985 to December 1989 were reviewed to determine the effect of early function on the 1-year patient and graft survival rates. Immediate function was present in 17 transplants; delayed graft function with acute tubular necrosis occurred in 16 cases. The 16 transplants with acute tubular necrosis (ATN) were treated with low dose cyclosporine. Among them, 13 patients had delayed function which resolved after 2 to 60 days of hemodialysis, but 3 grafts did not regain function. The allograft survival rate at 1-year was 68.7% for the delayed function group and 88.2% for the immediate function group. This difference was not statistically significant (p greater than 0.05). The 1-year patient survival rate was also not significantly different (87.5% vs 88.2%). There was no relationship between graft loss and duration of ATN. However, the graft survival rate in patients with a serum creatinine level below 2 mg/dL, after recovery either from ATN or non-ATN, was better than that for patients with a serum creatinine level of more than 2 mg/dL. The difference was statistically significant (95.8% vs 50.0%, p less than 0.02). It is concluded that delayed allograft function with acute tubular necrosis does not significantly alter the 1-year survival rates of patients and grafts in low-dose cyclosporine therapy. However, it is deleterious to the 1-year survival rate of an allograft when poor functional recovery occurs in an ATN or non-ATN condition.
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PMID:The outcome of delayed graft function in cadaveric renal transplants treated with low dose cyclosporine. 168 80

Oliguric acute renal failure occurs in some adult patients with minimal change glomerulopathy. To look for clinical and pathologic factors that increase the risk for developing acute renal failure, 21 adults with minimal change glomerulopathy and a serum creatinine greater than 177 mumol/L (mean, 486 mumol/L; range, 194 to 1,344 mumol/L) (greater than 2.0 mg/dL [mean, 5.5 mg/dL; range, 2.2 to 15.2 mg/dL]) were compared with 50 adults with minimal change glomerulopathy and a serum creatinine less than 133 mumol/L (mean, 88 mumol/L; range, 53 to 124 mumol/L) (less than 1.5 mg/dL [mean, 1.0 mg/dL; range, 0.6 to 1.4 mg/dL]). Minimal change glomerulopathy patients with acute renal failure were older (59.5 v 40.3 years, P less than 0.001), and had higher systolic blood pressure (158 v 138 mm Hg, P = 0.001), more proteinuria (13.5 v 7.9 g/24 h, P = 0.01), and more arteriosclerosis in the renal biopsy specimen (1.7 + v 0.7 + on a scale of 0 to 4+, P = 0.005). Tubular epithelial simplification identical to that observed with ischemic acute renal failure (acute tubular necrosis) was observed in 71% of the patients with serum creatinine greater than 177 mumol/L (greater than 2.0 mg/dL) and 0% of those with less than 133 mumol/L (less than 1.5 mg/dL). All 18 patients with renal failure for whom follow-up data were available had recovery of function (mean creatinine, 539 +/- 301 mumol/L [6.1 +/- 3.4 mg/dL] at the time of biopsy and 106 +/- 27 mumol/L [1.2 +/- 0.3 mg/dL] at last follow-up), but sometimes only after weeks of dialysis support.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Adult minimal change glomerulopathy with acute renal failure. 223 33

The light and electron microscopic morphology of 57 cadaver renal allografts was assessed at the time of procurement and again after revascularization. Twenty-two kidneys (39%) did not function immediately after transplantation and 19 of these (86%) contained morphologic evidence of acute tubular necrosis (ATN) in the procurement biopsy. The morphology of the post-transplant biopsy was abnormal in all 22 kidneys with delayed function. There was a wide spectrum of morphologic change between the time of procurement and revascularization in all kidneys with normal function. These changes were mild in nature, were usually confined to proximal tubules, and were of unknown clinical significance. The morphology of kidneys that were damaged by the time of procurement was surprisingly different after storage with simple hypothermia (ice) than after storage with hypothermic pulsatile perfusion. The changes attributed to ice storage included endothelial swelling and vacuolation with obliteration and collapse of capillary lumens, fracture and splitting of peritubular basement membrane, and hyalinization of the renal interstitium. It was unknown whether these morphologic abnormalities were associated with delayed recovery of function of the injured kidneys.
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PMID:Renal allograft acute tubular necrosis. II. A light and electron microscopic study of biopsies taken at procurement and after revascularization. 634 15

Kidney injury is repaired by inflammatory and non-inflammatory mechanisms, with the extent of recovery based on severity of the insult. Critical to the assessment of kidney repair is the ability to differentiate functional recovery from structural repair: compensatory increases in the function of intact residual nephrons often mask the inability of the kidney to heal or replace damaged structures. The mechanisms of repair reflect three levels of injury, which are handled differently by the kidney. First, DNA damage is countered by proof-reading DNA polymerases, backed by other controls for sequence misalignment/nucleotide replacement. If DNA cannot be repaired, cells harboring mutation(s) are lost through apoptosis, which is also critical to the disposal of kidney cells and infiltrating leukocytes in both acute and chronic ischemic, immunological, or chemical damage. This leaves room for a second mechanism of repair, i.e., cellular proliferation. At least 5 types of reparative proliferation are known to occur, some of which involve stem cell differentiation and perhaps immigration from distant reservoirs. The final type of repair is referred to as structural repair, actually quite limited by lack of postnatal nephrogenesis in the human kidney. Certain forms of recovery after acute tubular necrosis involve extensive remodeling of the proximal tubule, where integrity of the basement membrane is required for successful repair. Contrary to the long-held belief that only acute injury can be repaired, while ongoing chronic damage leads to progressive nephron loss, evidence is emerging that some degree of renal remodeling occurs even in the presence of persistent structural changes.
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PMID:Mechanisms of repair after kidney injury. 1276 65

Recovery from kidney injury through repair mechanisms often linked to inflammation is conditioned by nature and severity of the insult. In the assessment of kidney repair, functional recovery should be kept distinct from structural repair: compensatory hypertrophy/function of intact nephrons often masks the inability of the kidney to heal or replace damaged structures. The mechanisms of repair reflect three degrees of injury, differently handled by the kidney. First, repair of DNA damage is accomplished through proofreading DNA polymerases, along with other controls for sequence misalignment / nucleotide replacement. If DNA cannot be repaired, cells carrying mutation(s) are disposed of through apoptosis, which is also critical to clearing damaged kidney cells and infiltrating leukocytes in acute and chronic ischemic, immunological, or chemical damage. A second mechanism of repair is linked to proliferation of surviving cells. At least 5 types of reparative proliferation are known to occur, some of which implicate stem cell immigration from distant reservoirs, followed by in situ differentiation. A third mode of repair could be referred to as structural repair, indeed limited in the human kidney by the absence of postnatal nephrogenesis. Recovery from acute tubular necrosis involves remodelling of the proximal tubule, with a strict requirement for integrity of the basement membrane. Contrary to the current dogma that only acute injury can be repaired, whereas chronic damage leads to irreversible loss of nephrons, evidence is emerging that some degree of renal remodelling occurs even in chronic renal disease, despite the occurrence of stabilized structural changes.
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PMID:[Mechanisms of repair after renal injury]. 1288 44

There are few studies on the relationship between the morphology of acute tubular necrosis (ATN) in native kidneys and late functional recovery. Eighteen patients with acute renal failure (ARF) who had undergone renal biopsy were studied. All had the histological diagnosis of ATN and were followed for at least six months. Clinical characteristics of ARF were analyzed, and histological features were semi-quantitatively evaluated (tubular atrophy, interstitial inflammatory infiltrate, interstitial fibrosis, and ATN). According to the maximal GFR achieved during the follow-up, patients were divided into two groups: complete recovery (GFR >or= 90 mL/min/1.73 m(2)) and partial recovery (GFR < 90 mL/min/1.73 m(2)). Only 39% of the patients achieved complete recovery. Patients with partial recovery achieved their maximal GFR (63 +/- 9 mL/min/1.73 m(2)) 37 +/- 14 months after ARF, a period of time similar to those patients with complete recovery (i.e., 54 +/- 22 months). Patients with partial recovery had more severe ARF: oliguria was more frequent (90 versus 17%, p < 0.01), and they had higher peak creatinine (13.85 +/- 1.12 versus 8.95 +/- 1.30 mg/dL, p = 0.01), and longer hospitalization (45 +/- 7 versus 20 +/- 4 days, p = 0.03). No single histological parameter was associated with partial recovery, but the sum of all was when expressed as an injury index [4.00 (2.73-5.45) versus 2.00 (1.25-3.31), p < 0.05]. In conclusion, among patients with atypical ATN course, those with more severe ARF and tubule-interstitial lesions are more prone to partial recovery.
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PMID:Histological features of acute tubular necrosis in native kidneys and long-term renal function. 1870 14

Renal primary cilia are sensory antennas required for the maintenance of normal epithelial differentiation and proliferation in the kidney, but they also have a potential role in epithelial differentiation during renal injury and repair. In mice, tubular damage causes an increase in the length of renal cilia, which may modify their sensory sensitivity during repair. Here, we investigated whether the alteration of renal cilium length during renal injury is clinically relevant. Using biopsies of human renal transplants that suffered acute tubular necrosis during transplantation, we compared the length of renal primary cilia with renal function. Serial biopsies showed that acute tubular necrosis resulted in more than a doubling of cilium length throughout the nephron and collecting duct approximately 1 wk after injury. Allografts displayed a trend toward normalization of cilium length in later biopsies, and this correlated with functional recovery. A mouse model of renal ischemia-reperfusion confirmed the increase and subsequent regression of cilium length during renal repair, displaying complete normalization of cilium length within 6 wk of injury. These findings demonstrate that the length of renal cilia is a clinically relevant indicator of renal injury and repair.
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PMID:Renal primary cilia lengthen after acute tubular necrosis. 1960 4

Hepatocyte growth factor and its receptor, Met, activate biological pathways necessary for repair and regeneration following kidney injury. The Met receptor is expressed in multiple cell types within the kidney, each of which is capable of regulating fibrotic responses. To specifically address the role of the Met receptor in the adult collecting duct during renal injury, a conditional knockout mouse (Met(fl/fl);HoxB7-Cre) was generated and tested using unilateral ureteral obstruction, a model of nephron injury, fibrosis, and repair. Following obstruction in these mice there was increased expression of collagens I and IV along with plasminogen activator inhibitor 1, a known regulator of matrix degradation, compared to ureteral obstructed non-flox littermates. There were trends toward increased interstitial fibrosis, infiltration of the interstitium, and acute tubular necrosis in the knockout mice despite similar degrees of hydronephrosis to the control littermates. The Met(fl/fl);HoxB7-Cre mice; however, had reduced tubular cell proliferation and kidney regenerative capacity after release of the obstruction, thus leading to diminished functional recovery. We suggest that Met receptor signaling in the collecting duct acts as a major regulator of cell survival and propagation of the repair process with a possible secondary role to diminish inflammatory and fibrotic responses.
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PMID:Deletion of the Met receptor in the collecting duct decreases renal repair following ureteral obstruction. 1967 27

At present, ultrasonography (US) is not able to define the type of renal damage and therefore cannot replace percutaneous renal biopsy in the diagnosis of acute kidney disease. It is, however, the most immediate and safest imaging technique for the evaluation of patients with acute kidney injury (AKI) in order to exclude urinary tract obstruction or chronic kidney disease and guide clinical decision-making. In prerenal AKI caused by cardiorenal syndrome type 1, US does not show specific signs. However, in these patients, pleuropulmonary US is the first-choice imaging technique to evaluate the congestion of subpleural interlobular septa and to identify and count lung comet tails. In cardiorenal syndrome type 2, US visualizes signs of systemic overload (right pleural effusion, liver stasis, overdistention and rigidity of the inferior vena cava and suprahepatic veins). In acute tubular necrosis (ATN), the most common type of AKI, gray-scale US is nonspecific and shows enlarged kidneys with hypoechoic pyramids due to medullary edema. The resistance index (RI) is a very useful marker to establish the severity of ATN and the required follow-up, and to evaluate functional recovery, since its reduction precedes the normalization of serum creatinine. US is the technique of choice in the diagnosis of obstructive nephropathy, where it is highly sensitive (>95%) but less specific (<70%). The primary objective of this review is to analyze the applications of US in the diagnosis of prerenal, renal and postrenal AKI.
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PMID:[Ultrasound and color Doppler in nephrology. Acute kidney injury]. 2311 40


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