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Biomedical subjects

R Vanholder

Publications and source records attributed to R Vanholder.

At least 235 records · Page 13Linked to original sources
PubMed1984

Pathogenicity of cationized albumin in the dog: renal and extrarenal effects.

The effects of 21 cationized serum albumin samples of various degrees of cationization on renal function were studied in the dog. The samples were perfused intra- aortically to obtain preferential perfusion of the left kidney in 25 dogs. Standard clearance techniques were used, associated in six dogs with sieving studies of 125I-labelled polyvinylpyrrolidone (125I-PVP) and with an extensive morphological study in 15 dogs. Renal effects were observed. (a) Renal effects in left kidneys. The perfusion with weakly cationized albumin (group 1) produced moderate proteinuria associated with the deposition of cationized albumin on the anionic sites of the basement membrane. Glomerular filtration rate (GFR) was unaltered. Perfusion with highly cationized samples (group 2) produced more severe proteinuria and a significant decrease in GFR. Glomerular permeability to 125I-PVP increased. Perfusion with the four samples of highest pI (group 3) was followed by anuria. (b) Renal effects in right kidneys. A retarded mild proteinuria appeared only in group 2 and group 3 animals without alteration of GFR. All the kidneys (group 1 included), with the exception of two (group 3), showed deposition of the protein in the anionic sites. The following extrarenal effects were observed essentially in group 2 and group 3 animals: erythrocyte agglutination and haemolysis, platelet aggregation and thrombocytopenia, and a decrease in plasma fibrogen level due to fibrinogen precipitation. These effects produced progressive obstruction in the glomerular capillaries, thus explaining the occurrence of anuria. The structural damage in group 2 and group 3 left kidneys bears remarkable resemblance to that observed in the fulminant form of the human so-called 'haemolytic-uraemic syndrome'. The neutralization alone of the fixed negative charges in the glomerular wall appears to produce only mild proteinuria, whereas the various extrarenal effects combine to produce more severe proteinuria associated with functional alteration and vascular obstruction.

Acute Kidney Injury↗
PubMed1984

Comparison between mannitol and saline infusion in HgCl2-induced acute renal failure.

The effect of isotonic mannitol and saline in the early phase of mercuric chloride-(HgCl2-)induced acute renal failure (ARF) in the dog was evaluated. During the first 3 h after HgCl2 alone, glomerular filtration rate (GFR) fell from 1.94 +/- 0.14 to 1.04 +/- 0.11 and renal blood flow (RBF) from 13.99 +/- 1.18 to 7.28 +/- 0.77 ml/min X kg BW. Isotonic mannitol alone resulted in a fall of GFR by 22% (p less than 0.05 vs. control), but the subsequent administration of HgCl2 could not induce a further fall in GFR and RBF. A similar, if somewhat less pronounced, protective effect was observed when mannitol was started simultaneously with or 2 h after the HgCl2 injection. Infusion of isotonic saline at the same rate as mannitol did not prevent a fall of GFR and RBF from a premercury value of 2.33 +/- 0.31 to 1.36 +/- 0.26 and 16.83 +/- 3.06 to 9.30 +/- 2.65 ml/min X kg BW, respectively. In contrast, massive doses of isotonic saline, provoking urinary volume and solute losses comparable to those observed with mannitol, stabilized GFR after HgCl2 at the normal level (delta GFR = -3%). No relationship between delta GFR and urinary Hg excretion or renal tissue Hg content could be established. In summary, isotonic mannitol prevented the fall of GFR normally observed in the early phase of HgCl2-induced ARF. This effect was not volume mediated and not due to a higher Hg excretion. The protection was correlated with its osmotic diuretic effect.

Acute Kidney Injury↗
PubMed1983

Unipuncture membrane plasmapheresis.

A simple method of plasma exchange is presented that uses a hollow-fiber plasma filter together with conventional unipuncture dialysis equipment. The procedure was well tolerated for eight biweekly sessions in a patient with metastatic breast cancer.

Adenocarcinoma↗
PubMed1983

Fistula survival in single needle hemodialysis.

This study presents an average follow up per patient of 33.5 +/- 3.7 and 70.1 +/- 5.9 months (hospital and home dialysis) showing an actuarial fistula survival rate of 86.2% and 85.5% respectively after 5 years. The data suggest a satisfactory survival rate of the fistula when a single needle technique is used in comparison to the survival observed with the two needles technique.

Arteriovenous Fistula↗
PubMed1982

Dialysis performance of single lumen subclavian hemodialysis: a comparative study with single lumen fistula hemodialysis.

Study of hemodialysis performance and recirculation ratios of subclavian catheter hemodialysis is reported. Data are compared to the results obtained when a conventional intrafistular single-lumen hemodialysis needle is used under similar conditions. Renal blood flow values were slightly but not significantly lower for subclavian hemodialysis. Small molecular extraction ratios were identical. Small molecular clearances were somewhat lower for the subclavian approach, especially at high dialyzer blood flow rates. However, the differences were not significant, and overall extraction ratios, calculated for the entire dialysis period with both access methods in 43 patients, were identical. Recirculation averaged 12.5% for the fistular approach and 20% for the subclavian approach. It is concluded that, as a whole, dialysis performance is somewhat lower with the subclavian vascular access method. This is mainly due to a higher recirculation rate, and in turn to the consequence of the length of the intravascular device. However, this minor differences do not necessitate changes in dialysis schedules.

Catheterization↗
PubMed1982

Complications of subclavian catheter hemodialysis: a 5 year prospective study in 257 consecutive patients.

The complications related to the use of subclavian catheters for hemodialysis were prospectively studied in 257 consecutive acute and chronic renal failure patients. Using 394 catheters, 3006 single needle dialyses were performed. Indications for starting catheter dialysis were mainly the absence or disappearance of an adequate vascular access. Most hazardous complications were sepsis (9), malposition (6), hemothorax (3), bleeding (2), vena cava thrombosis (2) and pneumothorax (2). A number of mechanical problems occurred, where the obstructed catheter could easily be replaced by a modified Seldinger technique. No mortal complications occurred. Patient tolerance was excellent. It is concluded that single needle subclavian hemodialysis is a valuable alternative vascular access method in acute situations. It enables the continuation of hemodialysis on an ambulatory basis.

Acute Kidney Injury↗
PubMed1981

Diquat intoxication: report of two cases and review of the literature.

Animal experiments have suggested that diquat is less toxic than the more widely used paraquat. In this paper, nine previously reported cases of diquat intoxication are reviewed, together with the description of our personal observations in two additional patients. These two patients, like four other patients described in the literature, died from complications involving the gastrointestinal tract, brain and kidneys. Thus, diquat intoxication is apparently not as innocent as was originally thought. In this paper, special attention has been given to the major clinical differences between diquat and paraquat intoxication. In contrast with the latter, severe diquat intoxication induces gastrointestinal fluid sequestration and is associated with cerebral hemorrhagic lesions and a higher incidence of severe acute renal failure. Despite an asymptomatic clinical interval of up to 48 hours after ingestion, hemoperfusion should be started as soon as possible to prevent toxic levels of diquat in tissue.

Acute Kidney Injury↗
PubMed1981

Renal function studies in an experimental model of papillary necrosis in the rat.

Twenty four hours after i.v. injection of bromoethylamine-hydrobromide (BEA) in rats, a uniform papillary necrosis is observed. The present study investigates the renal functional and the papillary haemodynamics in response to acute volume expansion (12% of body weight) in this model. Renal function studies were performed in hydropenic and volume expanded sham- or BEA-injected rats. In hydropenic normal animals a GFR of 1.97 +/- 0.14 ml/min, an urinary osmolarity (UOsm) of 1 011 +/- 94.5 mOsm/kg and a fractional sodium excretion (FENa) of 0.18 +/- 0.026% were obtained. In contrast, BEA-treated hydropenic animals showed a lower GFR (1.16 +/- 0.14 ml/min), UOsm (469 +/- 30.31 mOsm/kg) and a higher FENa (0.37 +/- 0.06%). In volume expansion a similar UOsm and FENa were obtained in both groups. The papillary plasma flow (PPF) was measured in each of the experimental groups by the albumin accumulation technique. The mean value in hydropenic normal animals was 50.65 +/- 2.12 m 100 g-1 min-1 and increased to 66.02 +/- 2.00 ml 100 g-1 min-1 after volume expansion (P less than 0.001). In BEA rats the PPF was 58.86 +/- 2.33 ml 100 g-1 min-1 in hydropenia (P less than 0.01 vs. control animals) and remained unchanged after volume expansion. Thus, during hydropenia, BEA-induced papillary necrosis results with a salt wasting state and an urinary concentration defect. After volume expansion no disturbance in sodium excretion capacity was observed. These results are compatible with the nephron-heterogeneity concept in the regulation of sodium excretion. The histological lesions cannot be explained by a decreased renal papillary plasma flow.

Animals↗
PubMed1981

Double lumen needle in unipuncture dialysis type double headpump.

Single needle dialysis is used as a method of vascular access in many European dialysis centres. However, recirculation has been incriminated as a disadvantage of this procedure. According to in vitro studies, recirculation should be limited to a minimum when using double lumen needles. The present study makes an in vitro comparison between single and double lumen needles in unipuncture (single needle) dialysis of the type double headpump (Bellco, BL 760) and studies the role of recirculation in dialysis performance. Although recirculation is significantly reduced with the double lumen needle, compared to the single lumen needle, the clearance of small molecules is not significantly different for both needle types.

Adult↗
PubMed1980

Sieving studies in 'urea-induced nephropathy' in the dog.

1. The intrarenal infusion of concentrated urea after clamping of the renal artery produced immediate proteinuria in the dog. The predominant lesion on ultramicroscopy was destruction of the epithelial layer. Colloidal iron staining showed decreased fixed anionic charges in the capillary wall. 2. Sieving studies with neutral macromolecules such as 125I-labelled polyvinylpyrrolidone and [3H]dextran or an electronegatively charged polymer, [3H]dextran sulphate, showed a moderate increase in permeablility to the neutral tracers and a much more severe alteration of the lectrostatic barrier to the anionic polymer. The fractional clearance of dextran sulphate molecules increased to a greater extent than clearance of neutral dextrans of comparable size. 3. The shape of the curve relating the fractional clearance of dextran sulphate to molecular size is also modified in the contralateral kidney. This may be due to elevated plasma angiotensin II concentrations.

Animals↗
PubMed1980

Role of medullary hemodynamics in the natriuresis of drug-induced renal vasodilation in the rat.

In contrast to most renal vasodilators, such as acetylcholine (ACh), secretin increases renal blood flow in the dog without a marked effect on sodium excretion (UNaV). To investigate this observation, we studied the relationship between renal vasodilation, UNaV, and papillary plasma flow (PPF) in rats, infused either with ACh or secretin into the aorta at the level of both renal arteries. ACh significantly increased GFR, PAH clearance, and UNaV (delta + 0.35 ml/min, + 2.11 ml/min and + 1.77 muEq/min, respectively; P < 0.05). PPF rose from 50 +/- 2.6 ml/min 100 g (mean +/- SE) in control rats to 91 +/- 4.7 ml/min 100 g after ACh (p < 0.001). Despite a similar increase in PAH clearance after secretin (+ 2.21 ml/min; P < 0.01), UNaV remained unchanged and PPF was only slightly, although significantly, increased (from 50 +/- 2.6 ml/min 100 g to 65 +/- 2.75 ml/min 100 g; P < 0.05). Both total kidney and papillary vasodilation, and the increase in UNaV after ACh were blocked by previous administration of meclofenamate (M), a prostaglandin inhibitor. No effect of M in secretin-infused rats was observed. In conclusion, the relationship between a total renal vasodilation and natriuresis was dissociated with secretin, but not with ACh. However, a relationship between the natriuresis and influence on papillary hemodynamics was observed with both vasodilators. Finally, the renal hemodynamic and natriuretic effects of ACh are probably mediated by prostaglandin release.

Acetylcholine↗
PubMed1979

Reye's syndrome in an adult.

Reye's syndrome or encephalopathy with fatty infiltration of the liver occurs mainly in childhood and to a lesser degree in adult age. This report concerns a rare adult case of this syndrome in Europe. The different diagnostic steps are described, with special emphasis on the enzymatic disturbances of the Krebs-Henseleit cycle and on the morphological criteria needed to confirm the diagnosis.

Adult↗