497 research outputs found
Ischemic renal diseases: New insights into old entities
Ischemic renal diseases: New insights into old entities. Vascular nephropathies are a steadily increasing cause of end-stage renal failure. Arterionephrosclerosis and arteriolonephrosclerosis are common features in the hypertensive patient. This is especially true for blacks of African descent, in whom hypertension and nephrovasculopathies are a major cause of renal insufficiency. That primary hypertension leads to renal vascular lesions, glomerular obsolescence and interstitial fibrosis has long been established. It should not, however, obscure the fact that renal vascular lesions can be observed in animal models as well as in some humans, especially young blacks, in the absence of, or anticipating the onset of hypertension. This leads to considering the hypothesis that nephroangiosclerosis might stem from a genetic defect in the renal vascular bed and that this defect is strongly associated with the hypertensive trait. Atherosclerotic renal disease is a major, potentially treatable cause of chronic renal failure, especially in whites. It leads to renal atrophy, but the ischemic kidney retains a vigorous potential for tubular cell regeneration, which pleads for early recognition and treatment. Recent data suggest that renal ischemia, be it due to renal artery stenosis or to cholesterol crystal embolism, ranks among the multiple causes of secondary focal segmental glomerulosclerosis. Irrespective of its initial mechanism, ischemia induces renal fibrosis, the pathophysiology of which is centered on increased generation of angiotensin II. Finally, renal vascular lesions are commonly observed in the course of various nephropathies, even in the absence of hypertension, and the relationship between these lesions and the unfavorable prognosis of glomerulopathies, especially primary focal-segmental glomerulosclerosis, membranous glomerulopathy and IgA glomerulonephritis, remains to be elucidated. Expanding knowledge of the spectrum of nephrovasculopathies opens perspectives for investigating, understanding and treating a major mechanism of progressive renal insufficiency
Les causes d'élimination en épreuves d'endurance équestre : étude rétrospective menée en France en 2001
Les causes d'intolérance à l'exercice d'endurance sont nombreuses car la sollicitation du cheval est énorme et l'exercice prolongé entraîne une importante perturbation de l'équilibre des différents systèmes de l'organisme. Pour ménager la santé et la carrière sportive du cheval, la réglementation des raids d'endurance évolue et laisse une place importante aux vétérinaires chargés d'évaluer à chaque contrôle, l'état de santé et l'aptitude du cheval à poursuivre son effort sans risque exagéré. Cette étude montre que les boiteries sont la première cause d'élimination, qu'il n'y a a priori aucune corrélation entre les performances et la race, le sexe ou l'âge des chevaux. De nombreux facteurs de risque existent mais beaucoup peuvent être évités par l'anticipation, la qualité de l'entraînement et l'expérience
The diagnostic yield of transjugular renal biopsy. Experience in 200 cases
Renal histology remains the keystone of diagnosis in most parenchymal renal diseases and especially in glomerulopathies [1–3]. Sampling of renal tissue by percutaneous needle biopsy was described by Iversen and Brun in 1951 [4]. This procedure is usually safe, provided contraindications are respected [5–10]. Such contraindications include uncontrolled hypertension and/or bleeding disorders, which can favor severe perirenal hematoma. Even when these contraindications are heeded, systematic computerized tomography (CT) showed that the incidence of perirenal hematoma discovered by CT scan (irrespective of its clinical manifestation) is 57 to 85% [11, 12].In the absence of contraindications, there are patients in whom the slightest possibility of a complication necessitating lombotomy for hemostasis would be ethically incompatible with renal biopsy. This is the case, for instance, in patients with morbid obesity or with chronic respiratory insufficiency, in whom general anesthesia might represent a considerable hazard. Finally, there are cases where the size or the anatomical location of the kidney makes renal tissue sampling difficult or impossible. Ultrasound or CT scan-guided biopsy [13–15] does not always obviate such pitfalls. Other, more invasive methods have been proposed to sample kidney tissue, for instance by means of a short lombotomy [16–21], but this approach, which in addition necessitates the use of an operating room and several days of hospitalization, is similarly inapplicable in a patient with severe bleeding disorder or morbid obesity.We have described a novel technique of renal biopsy using the transjugular route, inspired from that used for liver biopsy in patients with clotting disorders in whom the percutaneous route would similarly be precluded [22–24]. This new technique was published in abstract form [25], and we reported our preliminary results on 50 cases [26]. The goal of this Technical Note is to analyze our present experience on 200 procedures carried out in 195 patients
Binocular field configuration in owls:the role of foraging ecology
The binocular field of vision differs widely in birds depending on ecological traits such as foraging. Owls (Strigiformes) have been considered to have a unique binocular field, but whether it is related to foraging has remained unknown. While taking into account allometry and phylogeny, we hypothesized that both daily activity cycle and diet determine the size and shape of the binocular field in owls. Here, we compared the binocular field configuration of 23 species of owls. While we found no effect of allometry and phylogeny, ecological traits strongly influence the binocular field shape and size. Binocular field shape of owls significantly differed from that of diurnal raptors. Among owls, binocular field shape was relatively conserved, but binocular field size differed among species depending on ecological traits, with larger binocular fields in species living in dense habitat and foraging on invertebrates. Our results suggest that (i) binocular field shape is associated with the time of foraging in the daily cycle (owls versus diurnal raptors) and (ii) that binocular field size differs between closely related owl species even though the general shape is conserved, possibly because the field of view is partially restricted by feathers, in a trade-off with auditory localization
Effect of cyclosporin A on proteinuria in the course of glomerulopathy associated with WT1 mutations
Denys–Drash syndrome (DDS) is characterized by progressive glomerulopathy caused by diffuse mesangial sclerosis (DMS), genitourinary defects, and a higher risk of developing Wilms’ tumor. It is commonly assumed that the DMS is unresponsive to any medications. In this report, we present a patient with Denys–Drash syndrome, in whom the cyclosporine A (CsA) was found to induce total remission. This observation and observations of other authors confirm that in genetic forms of nephrotic syndrome, the proteinuric effect of CsA may be due to a non-immunologic mechanism. We confirm the beneficial effect of CsA treatment in DDS; however, the potential nephrotoxicity of this drug will probably not allow long-term use
A Randomized Trial of Cyclosporine in Patients with Steroid-Resistant Focal Segmental Glomerulosclerosis
Background A clinical trial of cyclosporine in patients with steroid-resistant focal segmental glomerulosclerosis (FSGS) was conducted. Despite the fact that it is the most common primary glomerulonephritis to progress to renal failure, treatment trials have been very limited. Methods We conducted a randomized controlled trial in 49 cases of steroid-resistant FSGS comparing 26 weeks of cyclosporine treatment plus low-dose prednisone to placebo plus prednisone. All patients were followed for an average of 200 weeks, and the short- and long-term effects on renal function were assessed. Results Seventy percent of the treatment group versus 4% of the placebo group (P < 0.001) had a partial or complete remission of their proteinuria by 26 weeks. Relapse occurred in 40% of the remitters by 52 weeks and 60% by week 78, but the remainder stayed in remission to the end of the observation period. Renal function was better preserved in the cyclosporine group. There was a decrease of 50% in baseline creatinine clearance in 25% of the treated group compared with 52% of controls (P < 0.05). This was a reduction in risk of 70% (95% CI, 9 to 93) independent of other baseline demographic and laboratory variables. Conclusions These results suggest that cyclosporine is an effective therapeutic agent in the treatment of steroid-resistant cases of FSGS. Although a high relapse rate does occur, a long-term decrease in proteinuria and preservation of filtration function were observed in a significant proportion of treated patients
A Case of Focal Segmental Glomerulosclerosis Associated with Aplastic Anemia
The pathogenic mechanism of focal segmental glomerulosclerosis (FSGS) and aplastic anemia are associated with immunologic events which lead to glomerular cell injury or hematopoietic cell destruction. We present an extremely rare case of FSGS with aplastic anemia in a 30-yr-old woman. The laboratory examination show-ed hemoglobin 7.2 g/dL, white blood count of 4,200/µl, platelet count 70,900/µl. Proteinuria (2+, 3.6 g/day) and microscopic hematuria were detected in urinalysis. The diagnosis of FSGS and aplastic anemia were confirmed by renal and bone marrow biopsy. She was treated with immunosuppressive therapy of prednisone 60 mg/day orally for 8 weeks and cyclosporine A 15 mg/kg/day orally. She responded with gradually improving her clinical manifestation and increasing peripheral blood cell counts. Prednisone was maintained at the adequate doses with tapering after 8 weeks and cyclosporine was given to achieve trough serum levels of 100-200 ng/mL. At review ten month after diagnosis and initial therapy, the patient was feeling well and her blood cell counts increased to near normal (Hb 9.5 g/dL, Hct 32%, WBC 8,300/µl, platelet 123,000/µl) and renal function maintains stable with normal range proteinuria (0.25 g/day)
Cholesterol-crystal embolism presenting with delayed graft function and impaired long-term function in renal transplant recipients: two case reports
Introduction Impaired renal function and/or pre-existing atherosclerosis in the deceased donor increase the risk of delayed graft function and impaired long-term renal function in kidney transplant recipients. Case presentation We report delayed graft function occurring simultaneously in two kidney transplant recipients, aged 57-years-old and 39-years-old, who received renal allografts from the same deceased donor. The 62-year-old donor died of cardiac arrest during an asthmatic state. Renal-allograft biopsies performed in both kidney recipients because of delayed graft function revealed cholesterol-crystal embolism. An empiric statin therapy in addition to low-dose acetylsalicylic acid was initiated. After 10 and 6 hemodialysis sessions every 48 hours, respectively, both renal allografts started to function. Glomerular filtration rates at discharge were 26 ml/min/1.73 m2 and 23.9 ml/min/1.73 m2, and remained stable in follow-up examinations. Possible donor and surgical procedure-dependent causes for cholesterol-crystal embolism are discussed. Conclusion Cholesterol-crystal embolism should be considered as a cause for delayed graft function and long-term impaired renal allograft function, especially in the older donor population
Effects of Cyclosporin A Therapy Combined with Steroids and Angiotensin Converting Enzyme Inhibitors on Childhood IgA Nephropathy
To evaluate the effects of cyclosporin A (CyA) on clinical outcome and pathologic changes in children with IgA nephropathy (IgAN), we retrospectively evaluated 14 children (mean age 8.9±2.9 yr; eight males, six females) who were treated with CyA and steroids. The starting dose of CyA was 5 mg/kg per day, and the drug level was maintained at 100-200 ng/mL. The mean CyA level was 183.8±48.3 ng/mL (range 120.7-276.0 ng/mL) and the mean duration of CyA therapy was 10.9±1.9 months (range 8-12 months). After CyA therapy the mean 24 hr urinary protein excretion declined from 107.1±35.1 mg/m2/hr to 7.4±2.4 mg/m2/hr (P<0.001) and serum albumin increased from 3.3±0.6 g/dL to 4.3±0.3 g/dL (P<0.001). At a follow-up biopsy the histological grade of IgAN was improved in seven (50%) of the 14 patients, remained the same in three (21%), and was aggravated in four (29%). Serum creatinine, creatinine clearance, and blood pressure did not differ before and after CyA therapy. Two patients (14%) showed CyA-induced nephrotoxicity at the second biopsy. Our findings indicate that CyA therapy may be effective in reducing proteinuria and regressing renal pathology in a subset of children with IgAN
Cyclosporin in idiopathic glomerular disease associated with the nephrotic syndrome : Workshop recommendations
Management of idiopathic glomerular disease associated with nephrotic syndrome (INS) remains controversial and one of the most complex areas relates to utilization of the drug cyclosporin. This is despite its demonstrated effectiveness in several histologic types of the INS in randomized controlled trials. Cyclosporin is effective in inducing remission of proteinuria in approximately 80% of steroid-sensitive cases of minimal change disease (MCD). Cyclosporin is also effective in both the induction of remission and long-term preservation of renal function in steroid-dependent/-resistant MCD and steroid-resistant focal segmental glomerulosclerosis (FSGS). The overall response rate in FSGS is lower than in MCD, and long-term therapy (>12 months) may be required to both achieve remission and sustain it. Cyclosporin therapy is also of benefit in reducing proteinuria in 70-80% of patients with steroid-resistant membranous nephropathy (MGN). In MGN, the maximum benefit is often delayed compared to MCD (>12 weeks). Cyclosporin is generally well tolerated and safe. The major concern remains the nephrotoxicity, but with careful monitoring of the patient's renal function; minimizing the maintenance dose and utilizing repeat renal biopsy in those receiving long-term therapy, this risk can be minimized. The algorithms have been developed derived from the best evidence in the literature in each of the histologic types to help provide a guide to the integration of cyclosporin into the management of INS for the practicing nephrologist
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