Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UMLS:C0034186 (pyelonephritis)
 6,144 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Long-term allograft survival poses a major problem in pediatric renal transplantation, with allograft nephropathy being the principal cause of graft failure after the first post-transplant year. The mechanisms of nephron loss resulting in graft dysfunction are multiple, comprising both immunologic factors such as acute and chronic antibody- or T-cell-mediated rejection and non-immunologic components. The latter include peri-transplant injuries and renovascular lesions (renal artery stenosis, thrombosis) as well as cardiovascular risk factors such as arterial hypertension and hyperlipidemia. Another relevant issue leading to progressive nephron loss and declining kidney transplant function is acute and chronic nephrotoxicity induced by the calcineurin inhibitors (CNIs) ciclosporin (cyclosporine microemulsion) and tacrolimus. Furthermore, the presence of an abnormal lower urinary tract as well as bacterial (recurrent pyelonephritis) and viral (cytomegalovirus [CMV], polyomavirus [BK virus; BKV]) infections are crucial factors involved in the incidence of chronic allograft dysfunction and graft failure. Renovascular lesions and lower urinary tract obstruction are typical indicators for surgical intervention. The aim of treatment in pediatric patients with renal failure secondary to a dysfunctional lower urinary tract is to create a sterile, continent, and nonrefluxive reservoir. Surgical techniques such as bladder augmentation and the introduction of intermittent catheterization and anticholinergic therapy have significantly improved graft outcome. Arterial hypertension, another factor responsible for graft function deterioration in pediatric renal transplant recipients, is controlled preferably by the use of angiotensin converting enzyme (ACE) inhibitors or angiotensin II receptor antagonists, which are known to possess nephroprotective properties in addition to their potent antihypertensive effects. Although treatment of subclinical rejection with augmented immunosuppression has been associated with better graft survival, an increase of the immunosuppressive level to avoid subclinical rejection should be weighed against the risk of infection. The majority of viral infections affecting kidney allografts are caused by CMV and BKV. Antiviral CMV prophylaxis or pre-emptive therapy with ganciclovir has been shown to have beneficial effects in the pediatric renal transplant population. Treatment of BKV-induced nephropathy is based on reduction of the immunosuppressant therapy, although specific antiviral agents such as cidofovir and leflunomide are known to inhibit BKV. However, cidofovir itself is nephrotoxic and should therefore be administered cautiously to pediatric renal transplant patients. Since CNIs are likewise known for their nephrotoxic effects, especially with long-term use, alteration of the immunosuppressant regimen is necessary in case of deteriorating graft function due to CNI-induced histopathologic changes. Complete CNI avoidance seems inappropriate because, in this situation in pediatric renal transplant recipients, other relatively potent immunosuppressant agents such as lymphocyte-depleting antibodies, which are frequently accompanied by a higher incidence of infections, are needed for rejection prophylaxis. CNI withdrawal and switching of the immunosuppressant regimen from CNI therapy to sirolimus may be an option for some pediatric renal transplant patients with less advanced graft function deterioration. Nevertheless, potential adverse events such as aggravation of proteinuria, hyperlipidemia, myelosuppression, and hypergonadotropic hypogonadism have to be considered, and controlled studies are lacking. At present, an immunosuppressant maintenance therapy composed of low-dose tacrolimus or ciclosporin (CNI minimization) and mycophenolate mofetil with low-dose corticosteroids appears to be the most promising strategy to adopt in pediatric renal transplant recipients at low or normal immunologic risk.
 ...
PMID:Treatment strategies to minimize or prevent chronic allograft dysfunction in pediatric renal transplant recipients: an overview. 1987 24

Applications of diffusion-weighted (DW) magnetic resonance (MR) imaging outside the brain have gained increasing importance in recent years. Owing to technical improvements in MR imaging units and faster sequences, the need for noninvasive imaging without contrast medium administration, mainly in patients with renal insufficiency, can be met successfully by applying this technique. DW MR imaging is quantified by the apparent diffusion coefficient (ADC), which provides information on diffusion and perfusion simultaneously. By using a biexponential fitting process of the DW MR imaging data, these two entities can be separated, because this type of fitting process can serve as an estimate of both the perfusion fraction and the true diffusion coefficient. DW MR imaging can be applied for functional evaluation of the kidneys in patients with acute or chronic renal failure. Impairment of renal function is accompanied by a decreased ADC. Acute ureteral obstruction leads to perfusion and diffusion changes in the affected kidney, and renal artery stenosis results in a decreased ADC. In patients with pyelonephritis, diffuse or focal changes in signal intensity are seen on the high-b-value images, with increased signal intensity corresponding to low signal intensity on the ADC map. The feasibility and reproducibility of DW MR imaging in patients with transplanted kidneys have already been demonstrated, and initial results seem to be promising for the assessment of allograft deterioration. Overall, performance of renal DW MR imaging, presuming that measurements are of high quality, will further boost this modality, particularly for early detection of diffuse renal conditions, as well as more accurate characterization of focal renal lesions.
 ...
PMID:Diffusion-weighted MR imaging of native and transplanted kidneys. 2143 95

Ultrasound is the most important non-invasive diagnostic tool for detecting morphological pathological alterations of the kidneys. With a low patient burden it permits rapid, potentially serial and highly reproducible bed-side diagnoses of postrenal acute kidney injury and chronic kidney disease. Within chronic kidney disease, polycystic kidney disease can reliably be detected and evidence can be obtained for ischemic nephropathy, diabetic nephropathy and chronic pyelonephritis by renal size and intrarenal morphological alterations. An additional domain of ultrasound is the differentiation of the dignity of solid and cystic renal lesions. Newly introduced contrast-enhanced ultrasound is of additional help as benign and malignant lesions display different perfusion patterns. Renal artery stenosis can reliably be identified and its hemodynamic effect can be assessed with a combination of direct and indirect criteria by Doppler and duplex ultrasound.
 ...
PMID:[Renal sonography]. 2234 37

A 22-year-old pregnant female with pyelonephritis was found to have a 26-mm left renal artery aneurysm with unknown right kidney agenesis diagnosed by magnetic resonance imaging. Computed tomographic angiography with 3-dimensional reconstructions confirmed a saccular aneurysm localized at the bifurcation of the left posterior segmental artery. The patient ultimately underwent successful ex vivo left renal artery aneurysm repair with autotransplantation. Pathologic evaluation of the resected aneurysm confirmed the diagnosis of fibromuscular dysplasia. Fibromuscular dysplasia is the most common cause of renal artery stenosis and renovascular hypertension and can, in rare cases, be associated with the development of renal artery aneurysms.
...
PMID:Solitary kidney with renal artery aneurysm repaired by ex vivo reconstruction. 2492 85

Insufficient international coordination of medical research and partial isolation from the international scientific community can result in repetition of research already performed in other countries. Renal biopsy was broadly used for research in the former Soviet Union. It was performed, sometimes without sufficient clinical indications, in patients with amyloidosis, renovascular hypertension (from both kidneys: on the side of the renal artery stenosis and the contralateral one), chronic alcoholism, and acute and chronic pyelonephritis (intraoperative wedge and core biopsies). In chronic alcoholism, biopsies were taken from kidneys, pancreas, salivary glands, stomach, lung, skin, and liver, sometimes repeatedly. The classification of glomerulonephritis was different from those used internationally, for example, it did not include IgA nephropathy as a separate entity. Several examples of studies based on renal biopsies are discussed in this paper. A conclusion is however optimistic: the upturn in economy enables today to modernize equipment and introduce new methods, while broadening international cooperation facilitates the flow of foreign experience into the country. The purpose of this paper was to prevent inadequate use of renal biopsy in future.
...
PMID:Renal biopsy research in the former soviet union: prevention of a negligent custom. 2496 33


<< Previous 1 2 3