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Biomedical subjects

H Beaufils

Publications and source records attributed to H Beaufils.

At least 55 records · Page 3Linked to original sources
PubMed1994

Iodinated contrast media-induced nephropathy: pathophysiology, clinical aspects and prevention.

Administration of iodinated contrast media (CM) for radiographic purposes is a preoccupying cause of acute renal failure. This review of the literature deals with what is known about physiopathology, clinical course, risk factors and prevention. Factors involved in the pathophysiology of CM-induced acute renal failure are vasoconstriction, direct tubular cell injury and tubular obstruction by casts. In the case of pre-existing renal hypoperfusion, CM may disturb the complex interaction between factors which modulate renal haemodynamics by increasing vasoconstrictor factors, notably endothelin peptides. The renal medulla, a zone characterized by a high metabolic activity and a low oxygen tension, may be a specific target for CM-induced effects. CM-induced nephropathy (CMN) is essentially observed in patients with one or more associated risk factors (chronic renal failure, dehydration, diabetes mellitus with impaired renal function, multiple myeloma, large CM volume, intra-arterial rather than intravenous route, etc). There is much debate as to whether newer low osmolar CM (LOCM) are better tolerated than conventional high osmolar CM (HOCM). Most of the animal studies clearly demonstrate the advantages of LOCM over HOCM. Clinical literature is far more confusing, although some recent studies and one meta-analysis demonstrate that LOCM are better tolerated in patients with impaired renal function. The low number of comparative clinical trials carried out in high risk patients, wide variability in CMN definitions, limited number of patients enrolled and inadequacy of various selected endpoints may explain difficulties experienced in demonstrating this advantage. Furthermore, while hydration is correctly maintained during clinical trials, this is not always true in clinical practice. Such a discrepancy could lead to underestimation of the potential advantage of LOCM over HOCM. Effective prevention should associate the correct hydration of patients, identification and, when possible, optimal correction of risk factors, avoidance of repeated CM injections within a short period of time and temporary disruption of treatment with other nephrotoxic drugs (non steroidal antiinflammatory drugs, aminoglycosides, etc).

Acute Kidney Injury↗
PubMed1993

Disseminated histoplasmosis with glomerulonephritis mimicking Wegener's granulomatosis.

Renal complications of disseminated histoplasmosis include chronic recurrent abcesses of the interstitium and urogenital tract. To our knowledge, glomerulonephritis has never been reported in histoplasmosis. We describe a case of proven histoplasmosis presenting with oral granulomatous ulceration and segmental glomerulonephritis that mimicked Wegener's granulomatosis (WG). All symptoms and renal parameters remitted under itraconazole treatment alone. In conclusion, glomerulonephritis may complicate the course of chronic disseminated histoplasmosis. Since it can masquerade as WG, systematic tissue staining for intracellular microorganisms should be done when WG is suspected.

Diagnosis, Differential↗
PubMed1993

Comparative nephrotoxicity of carboplatin and cisplatin in euvolemic and dehydrated rats.

The aim of this study was to compare the renal tolerance of cisplatin and carboplatin in euvolemic and dehydrated rats. A total of 79 euvolemic or dehydrated male rats were randomly assigned to receive cisplatin (5 mg/kg body weight, i.p.), carboplatin (40 mg/kg body weight, i.p.) or vehicle. Body weight, serum creatinine, creatinine clearance, fractional excretion of sodium and urinary NAG excretion were recorded on days 1 and 5. Glomerular filtration rate (GFR), effective renal plasma flow (ERPF) and renal histology were determined on day 5. In the euvolemic and dehydrated control and carboplatin groups we observed no change in serum electrolytes, serum creatinine, creatinine clearance, GFR and ERPF. In the euvolemic and dehydrated control groups we observed no change in urinary NAG excretion. Carboplatin induced a slight but significant increase in urinary NAG excretion. In dehydrated rats carboplatin induced a significantly higher increase in urinary NAG excretion than in euvolemic rats. Cisplatin induced a marked and significant decrease in GFR and ERPF, and a significant increase in NAG. Dehydration markedly potentiated cisplatin nephrotoxicity. Euvolemic rats treated with cisplatin exhibited slight renal lesions with a mean score which was similar to the control group. The most extensive lesions were observed in euvolemic and dehydrated cisplatin treated rats with tubular necrosis in the outer stripe of the medulla.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1993

Modulation of the renal effects of contrast media by endothelium-derived nitric oxide in the rat.

RATIONALE AND OBJECTIVES: A possible involvement of endothelium derived relaxing nitric oxide (NO) in the pathogenesis of iodinated contrast media (CM)-induced nephrotoxicity was investigated in the rat. METHODS: Male rats (6 to 12 per group) were uninephrectomized. Six days later, the aorta was clamped above the renal artery and a low-osmolar contrast medium (CM), ioxaglate, was injected (1 mL/min; 3 minutes) via an aortic puncture in the single remaining kidney. Contrast medium was injected with or without the NO-synthase inhibitor L-NAME (100 mg/kg intravenously [i.v.] 5 minutes before CM). One group received L-Arginine, the physiological precursor of NO (100 mg/kg i.v.), 5 minutes before L-NAME. Phenylephrine (300 micrograms/kg; 30 min) was used as a vasoconstrictive NO-independent control. The effects of iohexol, another low-osmolar CM, on creatinine clearance (CrCl) were also studied with and without pretreatment with L-NAME. A control group was subjected to a 3-minute renal ischemia only. Creatinine clearance and urinary N-acetyl-beta-D-glucosaminidase (NAG) excretion were determined before, and 24 and 48 hours after CM administration. Blinded histologic analysis was carried out after completion of the study. RESULTS: When administered alone, neither L-NAME nor L-arginine modified CrCl. Ioxaglate mildly but significantly decreased CrCl at 24 hours (-26.5% of preinjection value). This was similar to the effect observed in the control group subjected to ischemia only. When associated with L-NAME, ioxaglate markedly decreased CrCl (-58 + 11% at 24 hours, P < .05 vs. ioxaglate alone). A similar interaction was noted in the case of iohexol. L-NAME also markedly increased ioxaglate-induced urinary NAG excretion. Phenylephrine had a similar impact on renal function. L-arginine pretreatment reduced the increase in serum creatinine induced by L-NAME+ioxaglate (68 + 17 mumol/L vs. 175 + 59 mumol/L for L-NAME+ioxaglate; P < .05) and urinary NAG excretion. Ioxaglate alone induced only tubular epithelial vacuolization. When associated with L-NAME, this CM induced tubular and vascular lesions, as well as necrosis in the outer medulla. Such histologic effects were clearly inhibited by L-arginine. CONCLUSION: These data indicate that L-NAME, a specific inhibitor of NO-synthase, and phenylephrine, accentuate the nephrotoxicity of CM in the rat. This is consistent with results from the literature showing that CM-toxicity is enhanced by renal ischemia.

Acetylglucosaminidase↗
PubMed1993

Chronic cisplatin nephropathy in rats.

The long-term renal effects of cisplatin have been very poorly studied. Therefore we investigated the chronic renal effects of various doses of cisplatin in three groups of male Sprague-Dawley rats. Group I received two injections of 5 mg/kg body weight (bw) at 4-week intervals, group II four injections of 2.5 mg/kg bw at 4-weeks intervals, and group III one injection of 5 mg/kg bw and four injections of 2.5 mg/kg bw at 4-weeks intervals. Controls received an equivalent amount of isotonic saline. Each group was evaluated 1, 3, or 6 months after the last injection of cisplatin. One, 3 and 6 months after the last injection, cisplatin induced a marked decrease in glomerular filtration rate (GFR) evaluated as clearance of [99mTc]DTPA and creatinine clearance in all treated rats. Urinary NAG excretion remained unaltered. At 3 months post-cisplatin treatment GFR was significantly less (P < 0.05) in group III (0.18 +/- 0.02 ml/min/100 g bw) when compared with group I (0.23 +/- 0.02 ml/min/100 g bw) or II (0.23 +/- 0.04 ml/min/100 g bw). In group I GFR was similar 1 month (0.24 +/- 0.02), 3 months (0.23 +/- 0.02) and 6 months (0.23 +/- 0.03 ml/min/100 g bw) after cisplatin treatment. Cisplatin induced atrophy and dilatation of tubules with mononuclear cell infiltration associated with cyst formation. The glomerular and tubulointerstitial lesions were significantly enhanced in group III when compared with groups I and II. This study indicates that repeated administration of cisplatin may induce a chronic tubulointerstitial nephropathy associated with a marked decrease in GFR, which is stable over time. The incidence and severity of chronic cisplatin toxicity is dose-related and is not modified by dividing the dose.

Animals↗
PubMed1992

Renal effect of anti-hypertensive drugs depends on sodium diet in the excision remnant kidney model.

Angiotensin converting enzyme inhibitors (ACEI) are believed to protect remnant kidney, but all previous studies used the ligation model which causes severe hypertension, and very few have compared drugs in rats having similar control of blood pressure (BP). We compared rats with uremia obtained by 70% excision of total renal mass, a model which causes mild, late hypertension. Study I compared the effects of enalapril (E), cicletanine (C) and placebo (P) in uremic (U) rats fed a 0.50% (normal-high) Na diet. Study II compared the effects of E, C, P, and guanfacine (G) in U rats fed a diet restricted to 0.25% Na (normal-low). In study I, UP rats developed progressive hypertension (140, 146, 160 and 166 mm Hg at 3, 6, 9 and 12 weeks), proteinuria (240 mg/day at 9 and 12 weeks) which were not affected by E or C. The occurrence of end-stage renal disease (ESRD) led to the sacrifice of all rats after three months. All three groups had similar severe renal lesions (over 25% sclerosed glomeruli in 5 of 10 UP, 9 of 14 UE, 7 of 14 UC rats, with huge cystic tubular dilatations). In study II, rats could be sacrificed later (6 months) and had evidence of less severe renal disease. All the drugs tested prevented hypertension throughout the study (P less than 0.001), with lowest values in UE rats. E and G, but not C, reduced proteinuria. Renal damage was reduced with E and G, but not with C, despite similar BP in C and G rats. Thus, in contrast with what was obtained in the ligation model, ACEI affected neither the BP nor the renal lesions of rats made uremic by renal excision and fed a 0.50% Na diet. Moderate Na restriction improved the consequences of nephron loss and restored the anti-hypertensive effect of drugs. However, these drugs had a different effect on renal preservation: it was dramatic with E, good with G, and undetectable with C.

Animals↗
PubMed1992

Supplemented low-protein diets protect the rat kidney without causing undernutrition.

Low-protein diets supplemented with keto-analogues and essential amino acid (KA-EAA) mixtures or with EAA have been widely used to retard renal deterioration without affecting nutrition. These assumptions have recently been challenged in clinical studies and rest on little or no experimental data. The effects of EAA and KA-EAA supplementations have not been compared. We compared three groups of rats with subtotal nephrectomy that were fed (1) a 16% casein reference (R) diet, (2) a 6% casein plus EAA (A) diet, or (3) a 6% casein plus KA-EAA (K) diet with KA as amino acid salts. The three diets had the same energy and mineral contents, and they induced comparable growth. The two supplements had the same nitrogen content. The only difference found until month 3 was higher proteinuria and plasma urea levels in group R rats. Renal biopsies performed at month 3 showed more severe glomerular sclerosis and tubular changes in R rats than in A and K rats. From months 3 through 7, R rats developed higher plasma creatinine levels than did A and K rats (final median values: 167, 106, and 83 mumol/L; p < 0.04), had more proteinuria (232, 56, and 84 mg/day), and showed greater mortality rates. At the time the rats were killed, 2 R, 6 A, and 5 K rats had survived while receiving the diets. Examination of the remnant kidneys, regardless of time of death, showed that renal lesions were significantly worse in R than in A and K rats, with sclerosis affecting more than 50% of the glomeruli in 7 of 13 R, 4 of 14 A, and 4 of 15 K rats, and less than 25% glomeruli in 2 of 13 R, 10 of 14 A, and 10 of 15 K rats (A and K vs R: p < 0.03). In conclusion, restriction of nonessential amino acids compensated by EAA or by KA-EAA mixtures retards renal damage without affecting growth, but no real benefit of KA or EAA has been observed.

Amino Acids, Essential↗
PubMed1991

Renal tolerance of AMI 25.

The objective of this study was to evaluate the renal tolerance of a new magnetic resonance contrast agent, AMI 25. This agent has an affinity for the reticuloendothelial system and is used for the detection of focal liver lesions. A combination of renal ischemia and intra-arterial iodinated contrast agent infusion (diatrizoate) leads to a reproducible and reversible model of acute renal failure in the rat. Using this model, AMI 25 was perfused directly into the aorta at the dose of 1 ml/kg--ten times the dose used in humans. AMI 25 induced no change in serum creatinine (45 +/- 7, 40 +/- 6, 40 +/- 9 mumol/L before infusion and at 24 and 48 hours, respectively), in creatinine clearance (2.1 +/- 0.6, 2.1 +/- 0.6, 2.1 +/- 0.6 mL/mn), or in urinary N-acetyl glucosaminidase (NAG) excretion (72 +/- 16, 98 +/- 12, 58 +/- 9.8 mumol hour-1/mmol creatinine). Blinded histologic analysis of 11 kidneys perfused with AMI 25 revealed no abnormalities, whereas diatrizoate induced acute tubular necrosis in four of the seven kidneys examined. In our animal model, AMI 25 has no nephrotoxicity, even at ten times the expected clinical dose for humans.

Acetylglucosaminidase↗
PubMed1990

[Drug-induced interstitial nephropathy with nephrotic syndrome].

A new syndrome is which immunoallergic interstitial nephropathy is associated with nephrotic syndrome has recently been described. The interstitial nephropathy is usually due to the consumption of non steroidal anti-inflammatory drugs, and it is characterized by interstitial lesions associated with minimal glomerular lesions. The typical clinical complex includes nephrotic syndrome, renal impairment, eosinophilia, microscopic haematuria, leucocyturia and, more rarely, clinical signs of hypersensitivity. The outcome is favourable as a rule, with recovery of the renal function ad integrum and complete recession of the nephrotic syndrome. The pathogenesis of the syndrome is no entirely clear, but it probably implies a delayed hypersensitivity reaction. Treatment consists of withdrawing the responsible drug(s) and applying medical intensive care methods. Whether or not corticosteroids influence the rapidity and quality of recovery remains uncertain.

Acute Disease↗
PubMed1990

Absence of humoral autoimmunity in peripartum cardiomyopathy. A comparative study in Niger.

The authors report a humoral immunity study in 39 black Nigerian women with peripartum cardiomyopathy. Serum immunoglobulins (IgG, IgA, IgM) assay, evaluation of serum immune complexes (immunonephelemetric method) and of heart muscle autoantibodies (indirect immunofluorescent double layer technique in heart muscle of the rat) were made. Forty breastfeeding black Nigerian women without cardiac disease were the controls. Differences between serum immunoglobulins, circulating immune complexes and heart muscle autoantibodies are not significant. This study demonstrates the absence of a humoral autoimmunity process in peripartum cardiomyopathy.

Adult↗
PubMed1990

Primary IgA nephropathies in children.

With the worldwide use of immunofluorescence microscopy, idiopathic IgA nephropathy (Berger's disease) has been recognized as a distinct form of primary glomerular disease. IgA nephropathy is the most common form of GN in many parts of the world. However, since the criteria for diagnosis are exclusively based on the findings of predominant IgA in the mesangium, the boundaries of this "entity" are not well delineated and it has become clear that several different clinical conditions share this common immunopathology. IgA nephropathy should, therefore be regarded as a syndrome. Schönlein-Henoch purpura (SHP) and Berger's disease represent the primary form of this syndrome. The clinical features of both diseases in children are reviewed. Although the clinical symptoms may appear different there is a close relationship between SHP and IgA nephropathy. They share the same pathology, the same pathogenesis, and they may both recur on a transplanted kidney. Moreover, both diseases can occur in a single family. When pathologic mechanisms are more defined, SHP may prove to be 1 end of a spectrum of diseases associated with microvascular immune deposits in which IgA is the predominant immunoglobulin seen, the other end being Berger's disease.

Child↗