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Biomedical subjects

H Favre

Publications and source records attributed to H Favre.

At least 91 records · Page 5Linked to original sources
PubMed1984

Natriuretic factor exerts a ouabain-like activity in the rat colon in vitro.

A previously described natriuretic factor (NF) found in urine from man receiving a high salt diet has been postulated to be of hormonal nature. This factor inhibits Na-K ATPase and binds to ouabain receptors. In order to investigate if NF exerts its physiological activity through the Na-K ouabain sensitive pump, its capacity for inhibiting sodium transport has been tested in an in vitro rat colon preparation. Colonic mucosa from rats fed 0.55, 3.55, and 6.55 mmol Na a day were mounted in an Ussing chamber. Inhibition of short-circuit current (SCC) and PD was observed only when NF was added to the serosal side of the membrane and was similar to that observed with ouabain. In rats fed a low or normal salt diet, inhibition of SCC and PD starts after a lag period of 10 min and reaches its maximum inhibition (about 60%) after 90 min. By contrast colonic mucosa from rats receiving a high salt diet exhibits a higher SCC and PD (basal values) and inhibition of the sodium transport starts immediately after addition of NF to the bathing solution. The data demonstrate the similarity of physiological action of ouabain and natriuretic factor on the sodium transport by the colon in vitro. Experiments with rats receiving a high salt diet suggest that by contrast to the kidney, NaCl-dependent cotransport is strongly stimulated by the salt intake in the colon and could be directly inhibited by ouabain or a ouabain-like substance i.e. NF.

Animals↗
PubMed1984

Effects of infrarenal aortic cross-clamping on renal hemodynamics in humans.

While the systemic cardiovascular consequences of infrarenal aortic cross-clamping during aortic abdominal surgery are well documented, its repercussions on renal hemodynamics in humans have not been reported. In 12 patients, scheduled for elective aortic surgery, renal clearances, using 51Cr EDTA and 125I hippuran, were measured before, during, and after infrarenal aortic cross-clamping. A continuous infusion of mannitol 20% at a rate of 100 ml/h was administered throughout the study. Arterial and renal venous blood sampling, obtained at the midpoint of each period, permitted calculation of the extraction fraction of 125I hippuran and accurate determination of renal blood flow and its cortical-extracortical distribution. Although cardiac output and systemic vascular resistance did not change significantly between the three study periods, infrarenal aortic cross-clamping decreased 125I hippuran clearance by 29 +/- 15% (P less than 0.05) and renal blood flow by 38 +/- 14% (P less than 0.001). Simultaneously, an increase of 75 +/- 31% in renal vascular resistance (P less than 0.05) was observed and the extraction fraction of 125I hippuran increased from 0.67 +/- 0.05 to 0.74 +/- 0.05 (P less than 0.01). All of these changes, which indicate global diminution of renal perfusion with a redistribution of renal blood flow toward the cortical compartment, persisted for at least 1 h after release of the aortic clamp. Early signs of renal tubular damage, such as the appearance of lysozyme and ligandine in the urine, however, were never observed. The authors conclude that infrarenal aortic cross-clamping produces profound and sustained alterations in renal hemodynamics and may be harmful in patients with impaired renal function or when surgical occlusion of the aorta is prolonged.

Aged↗
PubMed1984

Distal renal tubular dysfunction: a common feature in calcium stone formers.

Distal renal tubular acidosis has been reported as an uncommon cause of urinary calcium stone disease. However, this defect appears to be more frequent when appropriate tests are performed systematically. Twenty-nine patients with recurrent calcium stones have been separated into three groups: normocalciuric (group A), renal hypercalciuric (group B) and absorptive hypercalciuric (group C). Distal tubular functions were investigated by the (urine-blood) pCO2 gradient and by an ammonium chloride test. (Urine-blood) pCO2 gradient was (mean +/- SEM), 3.33 +/- 0.59 in group A, 2.95 +/- 0.34 in group B and 3.31 +/- 0.58 kPa in group C. All these values differ significantly from those observed in controls (4.11 +/- 0.28 kPa; P less than 0.05). After 3 days of ammonium chloride loading, ammonium excretion averaged 54.7 +/- 4.2 in group A, 54.4 +/- 4.3 in group B and 64.3 +/- 5.5 mumol min-1 in group C. Values obtained in the first two groups were significantly lower than that achieved by control subjects (76.4 +/- 14.9 mumol min-1). It is concluded that tubular dysfunctions defined as impairments in hydrogen ion secretion and ammonium excretion after an acid challenge are a common feature of the urinary calcium stone disease and play a contributory role in its pathogenesis.

Acid-Base Equilibrium↗
PubMed1984

Circulating immune complexes in regularly dialyzed patients with chronic renal failure.

The prevalence of circulating immune complexes (CIC) was investigated using the C1q binding assay (C1q BA) and the conglutinin binding assay (Kg BA) in 200 patients undergoing maintenance hemodialysis. Increased C1q binding was found in 45% (87 of 194) of the patients, and the modified Kg BA gave elevated values in 31% (20 of 65). The prevalence of CIC was similar in American and Swiss patients, and in patients undergoing hemodialysis, self-dialysis or peritoneal dialysis. In patients with 'nonimmunological' renal diseases, CIC were detected with similar frequency. No change in CIC was noted during hemodialysis in 6 additional patients tested. The abnormality was not related to age, sex, duration of dialysis, hepatitis B antigenemia, bacterial infections, or transfusions. Anti-DNA antibodies were absent in all subjects tested and the results of the C1q BA were not changed by DNase digestion of eight sera with high C1q binding. Rheumatoid factor activity (RF) was detected in approximately one-fifth of the patients, and there was a direct correlation between positive C1q binding and RF. There was no correlation between CIC and lymphocytotoxic antibodies. This study demonstrated a high prevalence of CIC in dialyzed uremic patients and established its relationship to other immunological abnormalities.

Antibodies, Antinuclear↗
PubMed1984

Treatment of peritonitis in continuous ambulatory peritoneal dialysis patients with co-trimoxazole.

Peritonitis in patients undergoing continuous ambulatory peritoneal dialysis (CAPD) represents the most frequent and difficult problem related to this new form of treatment of ESRD patients. Various treatments have been reported previously. The aim of this study was to investigate the efficiency of a standardized initial treatment in 45 episodes of peritonitis. This was designed to be rapidly efficient, devoided of side-effects and easy enough to be performed by the patients themselves. When peritonitis was clinically suspected, patients received intraperitoneal co-trimoxazole (80 mg trimethoprim, 400 mg sulfamethoxazole), in each of the four daily bags concomitantly with 1,000 U heparin during 2 weeks and half of this dose during 2 other weeks. Our results demonstrate that 88% of the isolates were sensitive to co-trimoxazole and 85% of the patients completed this treatment. All were cured and no relapses were observed. Only 18 days of hospitalisation were required in the 45 episodes of peritonitis. Another anti-infective agent was used in 3 cases of gram-negative peritonitis and 4 other initially resistant to co-trimoxazole. It is concluded that initial treatment of CAPD peritonitis with co-trimoxazole is justified by the high proportion of sensitive germs and that it represents a safe, efficient and inexpensive treatment.

Adult↗
PubMed1983

Estrogen-stimulated neurophysin in chronic renal failure.

Estrogen-stimulated neurophysin (ESN) was determined by radioimmunoassay in three groups of patients with chronic renal failure: predialysis patients, patients on hemodialysis and patients on continuous ambulatory peritoneal dialysis. ESN levels were significantly elevated in all patients. ESN of these patients is undistinguishable from highly purified pituitary ESN. Immunological and physicochemical analyses of ESN in patients with renal failure suggest that the elevated plasma level is due to a failure of renal clearance. In addition, heterogeneity of urinary ESN, revealed by multiple immunoreactive peaks after gel filtration, indicates altered renal metabolism.

Adolescent↗
PubMed1983

[Periarteritis nodosa: clinical presentation limited to severe kidney failure accompanied by arterial hypertension].

Two cases of severe renal failure and hypertension of a few weeks duration are reported. There were no symptoms nor signs suggestive of extra-renal involvement and the laboratory tests, more specifically those for the detection of inflammatory parameters, were normal. Renal angiograms revealed intraparenchymal arterial microaneuvrysms which led to the diagnosis of vasculitis of the periarteritis nodosa type. Combined immunosuppressive and steroid treatment was successful in both cases regarding blood pressure control and improvement of renal function. The importance of renal angiography as a diagnostic tool in this type of clinical setting is underlined, as well as the necessity for prompt and prolonged immunosuppressive therapy.

Adult↗
PubMed1981

[Chronic ambulatory peritoneal dialysis].

Continuous ambulatory peritoneal dialysis for end-stage renal failure was first described in 1976. The purpose of the present study was to establish the value of this method in a group of eight patients with various renal diseases who were controlled monthly for one year. Main benefit was correction of anemia, better control of calcium and phosphate, and excellent blood pressure control. Hyperlipoproteinemia was observed in all patients, as was an increase in plasma renin activity and aldosterone. Thyroid values were in the low normal range. A low incidence of peritonitis was observed and cases of peritonitis were treated on an ambulatory basis. The results suggest that more patients could be included in this new treatment for end-stage renal disease.

Adult↗
PubMed1981

Lack of sensitivity and specificity of the renal clearance of amylase/clearance of inulin ratio in experimental acute rat pancreatitis with a study on the renal handling of amylase.

As there are controversies about the specificity and the sensitivity of the amylase clearance/inulin clearance ratio (Cam/Cin) in the diagnosis of pancreatitis, this ratio has been calculated: (a) in rats with induced pancreatitis with histologically proven lesions; (b) in toxic induced tubulopathy rats with lesions demonstrated histologically and biologically (enzymuria). Hyperamylasaemia was found in 86% of the pancreatitis rats at 24 h, 50% at 48 h and 25% at 60 h. The ratio Cam/Cin was elevated above 2 SD of the control values among 14% of the rats at 24 h, 50% at 48 h and 25% at 60 h. There were no changes in enzyme elimination rates in the urine as compared to control values. Renal histology remained normal. Histological scores expressing a severe haemorrhagic pancreatitis were identical at 24, 48 ad 60 h. In toxic induced tubulopathy rats, amylasaemia remained normal. but the Cam/Cin ratio only increased when the glomerular filtration rate was diminished by 90%. The diagnosis could only be made by hyperamylasaemia in 50% of the histologically proven pancreatitis in the rat. The use of the ratio Cam/Cin does not increase the frequency of a correct diagnosis. Finally, amylase must be only filtered by the kidney as no tubular enzymes appeared in the urine of pancreatitis rats. Furthermore, this ratio is not specific for pancreatitis as it could be elevated in other pathologic states such as severe renal failure.

Acute Disease↗
PubMed1980

[The regulation of plasma aldosterone in hemodialysis patients].

The role of potassium in regulating plasma aldosterone has been studied in 7 patients with end-stage renal disease undergoing hemodialysis. Plasma renin activity (PRA), plasma aldosterone, cortisol, sodium and potassium, and total potassium loss were measured before and after two sessions of dialysis in each patient. The only difference between the two sessions was the potassium content of the dialysate (4 mmol/l versus l mmol/l). Plasma potassium, potassium pool and plasma aldosterone decreased significantly when the patients were dialyzed with a l mmol/l K bath. In contrast, the same parameters remained unchanged when the patients were dialyzed with a 4 mmol/l K bath. Irrespective of the dialysate used, there were no differences either in changes in body weight and PRA, or in plasma sodium and cortisol levels, before and after dialysis. In conclusion, in patients with end-stage renal disease, potassium predominates over PRA and volume depletion in the regulation of plasma aldosterone.

Adult↗
PubMed1980

[The "natriuretic factor" in patients with idiopathic edema].

The pathophysiological basis of idiopathic edema is not yet fully understood. To elucidate further the mechanism by which this syndrome occurs, natriuretic factor (NF) has been measured in the urine of 10 female patients with idiopathic edema receiving a diet containing 3-4 g NaCl a day. Twenty-four hour urines collected on an ambulatory basis were fractionated through a G-25 Sephadex column and fraction IV, which has been previously shown to possess natriuretic activity, was tested on a rat assay. Five of these patients exhibited NF activity averaging 183.2 +/- 68.7%, which was in agreement with their salt intake. In contrast, the remaining 5 patients have very high NF activity (1462.6 +/- 273.2%) on the same diet. An additional patient studied for 9 days under metabolic conditions and receiving 120 mEq NaCl a day retained the sodium ingested and gained 5.1 kg body weight. The NF activity increased from 367 to 2616% over the 9 day observation period, although no diuresis occurred at any time. In conclusion, 50% of the patients with idiopathic edema exhibited peripheral resistance to the action of the NF, a fact which may explain the syndrome. It may further serve to differentiate patients with "true idiopathic edema" from those with diuretics abuse.

Animals↗
PubMed1980

Natriuretic factor in rats acutely expanded by Ringer's versus albumin solution.

Previous studies have shown that it is possible to extract a natriuretic factor from the renal tissue of rats. This substance, which can be isolated by fractionation through a G-25 Sephadex column, shows a strong correlation with sodium elimination by the kidney. The present work was designed to compare the effects of expansion by a Ringer's solution versus an albumin solution on the presence of this factor and the natriuretic response in the rat. Albumin-expanded rats, like control nonexpanded rats, which have no natriuretic response, do not exhibit any active natriuretic factor in their kidneys. In contrast, significant activity of the natriuretic factor is found in the kidneys of Ringer-expanded rats, which also respond by a significant natriuresis (P less than 0.001). We conclude that the expansion of the extracellular fluid volume, as opposed to the expansion of the intravascular volume, only determines both the presence of the natriuretic factor and the physiologic natriuretic response. As the difference in the sodium transport by the renal tubule in these two modes of expansion takes place in the collecting duct, we suggest that the natriuretic factor acts at this level.

Albumins↗
PubMed1980

Basal activity of the natriuretic factor extracted from the rat kidney as a function of the diet and its role in the regulation of the acute sodium balance.

1. The effect of the sodium content of the diet on the natriuretic activity of an extract from the kidneys was studied in non-expanded and volume-expanded rats. 2. The kidney tissue was homogenized and the supernatant fractionated by gel filtration of Sephadex G-25. A single low-molecular-weight fraction eluted after the salt possessed the natriuretic activity and was tested on a rat bioassay. 3. The natriuretic activity of the fraction obtained from the kidneys of non-expanded rats was related to the sodium intake. 4. After an acute extracellular volume expansion, the natriuretic activity obtained from the fraction extracted from the kidneys was much greater than before expansion and was related to the dietary intake of sodium.

Animals↗