Fondation Medic

The erythropoietin (Ep) plasma titre of 41 anaemic patients with normal renal function or with renal insufficiency (with or without kidney) was measured by RIA and compared to values observed with the polycythaemic mouse assay. A good correlation was found with both methods (r = 0.88). However, about 20% of samples gave higher values with the bioassay. 21 Ep titres measurable by the bioassay ranged from 40 to 4400 mU (mean 717.1 mU) compared to 14.8 to 3788 mU (mean 484.7 mU) measured by the RIA. Low levels of Ep plasma titre have been observed in patients with renal insufficiency and no difference was found between nephric uraemic patients and the anephric group. These results suggest that the increased blood requirements in anephrics are not due to a smaller production of Ep, but ultimately to the presence of an inhibitor of erythropoiesis. The well-known inverse relationship between haematocrit and Ep level was not found in renal insufficiency. However, some humoral regulation of erythropoiesis seems to persist in these patients since the elevation of red blood cells by transfusions was followed by a decrease of the Ep level.

SummaryThe effect of a combined beta-blocking agent-diuretic therapy on blood pressure and renin-angiotensin has been avaluated. Two protocols have been used in 20 hypertensive patients. In the first one, the diuretic has been administered after a maximum dose of betablockade and in the second, beta-blockers have been given after a constant dose of diuretic. In both cases, the addition of the second drug produced a further fail in blood pressure. Physiopathologically, the drugs are compatible, because the stimulation of the renin-angiotensin-aldosterone system induced by diuretics is countered by beta-blockers.

The effects of furosemide on the in vitro performances of isolated prestored (24-hour storage in Collins solution) and control unstored canine kidneys were studied on the Nizet pump oxygenator. Prestorage reduced RBF, GFR, Na reabsorption rate and PAH extraction, while it increased free water clearance and K excretion rate. In prestored kidneys, the addition of furosemide to perfusing blood did not improve the hemodynamic parameters and did not influence PAH transport despite its usual effects on Na, K and water excretion. Moreover, in unstoredkidneys, furosemide somewhat decreased RBF and GFR.

SummaryThe analysis of 66 tissue samples obtained from 57 kidney grafts shows good correlation between the immune deposits observed in immunofluorescence and the histologic lesions of rejection. The high incidence of fibrinogen deposits demonstrates the importance of intravascular coagulation in the pathogenesis of graft destruction.

SCOPUS: ar.j

As a field of research, human cytogenetics is only 9 years old, but outstanding results have already been reported in numerous diseases. Further advances depend now essentially on the resolution of the microscope; as the limits of the optical system seem to have been reached, important new developments in cytogenetics should not be expected.

SummaryThe purpose of this work was to study, in clinical and experimental conditions, the influence of hypercalcemia on renal function and on plasma electrolytes.I. — Clinical and biological data of 24 adult hypercalcémie patients admitted to the medical department of the Brugmann University Hospital were described.Hypercalcemia was related to secondary neoplasm of lxinc in 14 patients. (Sites of origin were as follows : Lung : 4 eases, breast : 3 cases, prostate gland : 1 case, (esophagus : 1 case, kidney : 1 case, multiple myeloma : 2 cases, unknown : 2 cases.) In 9 patients, hyperparathyroidism was considered as the most likely diagnosis. One of these showed the features of an acute hypercalcémie crisis with a blood calcium level above 200 mg/1. Burnett's syndrome was responsible of hypercalcemia in the last patient.1. It was noted that hypercalcemia of most cancers though not that of parathyroid origin was accompanied by a systemic alkalosis, hypokaliema and an acid urine. A slight degree of potassium depletion occurred in 3 cases. In hyper-parathyroid patients, alkalosis was observed only in two patients and could be explained by vomiting or ingestion of alcalini/.ing salts.2. We have measured the pbosphatc/creatinine clearance ratios in most of our hypercalcémie patients; they were invariably increased, and thus the diagnostic approach of hypercalcémie states does not seem to lie made any easier by assessing these ratios.3. High urinary calcium output was observed in most cases. The patient with the milk alkali syndrome had a rather low calciuria, as is usually described in this condition.4. In most cases of hypercalcemia, renal insufficiency remained moderate. This was especially true in hyperparathyroidism. A severe degree of renal failure was never directly related to hypercalcemia, but associated with kidney stones or urinary infection.II. — Our experimental work was performed with dogs.The effects of acute hypercalcemia were studied in two different conditions :— or by injection of calcium chloride alone during 5 hours; between the end of the 1 st and the end of the 5th hour a single urinary collection was performed;— or bv simultaneous injection of calcium chloride and sodium bicarlxmate.Acute hypercalcemia induced by these procedures showed the following major changes in the urinary water and electrolyte excretion pattern :1) a definite diuretic effect accompanied by an increase of the free water clearance was observed.2) H+ and NH4+ output by the kidney was markedly enhanced.3) urinary bicarbonate decreased and chloride increased.4) a sharp raising of plasma inorganic phosphorus was invariably observed during calcium chloride infusions and in most cases the urinary excretion rose as a result of this procedure. Thus, it is obvious that hyperphosphoremia may not be considered as a consequence of reduced parathyroid activity.5) renal excretion of sodium and magnesium was well above control values during acute hypercalcemia. Potassium urinary excretion is not influenced by calcium infusion after tubular exchange mechanism of K is already stimulated by injection of sodium bicarbonate.III. — Chronic hypercalcemia was induced in 14 dogs: in 10 by daily ingestion of 900.000 Units vitamin D3 without any calcium supplements. In 4, lower doses of vitamin D were used, but together with calcium chloride or calcium lactate administration.1) During the first weeks of this treatment, plasma phosphorus rised and urinary 24-hours phosphate excretion was reduced; in most cases, blood pll and plasma potassium increased.A moderate raising of urinary output of water, calcium, magnesium, chloride and sodium was observed.2) After 6 to 10 weeks of vitamin D3 treatment, a definite hypercalcémie state developed. Glomerular filtration rate was reduced to about 50 % of its control state value. At this stage of toxicity, alkalosis occurred, without potassium depletion. Vomiting seemed to plav no part in this acid-base balance disturbance. A chloride depletion of renal origin appeared most likedv, but was not formally demonstrated.3) The administration of an acid load indicated that chronic hypercalcemia was associated with an impaired ammonium production by the kidneys. However, titrable acidity production and lowering of the urine pH were not significantly different from their control values.4) During sodium phosphate or bicarbonate infusions, blood calcium fell in dogs treated with toxic doses of vitamin D. Ammonium chloride ingestion had the same effect but at the same time improved the renal function, as demonstrated by an increase in the glomerular filtration rate.

SummaryThe correlation between the results of the sensitivity tests performed in vitroand the true activity of the antibiotics in vivo can be established only if numerous factors arc considered. These factors, such as absorption, binding to plasma proteins and excretion, are reviewed. The kinetic of the bactericidal activity of the treated patients should be measured in the blood.These measurements are indicated in patients with absorptive disturbances. Performed in some 40 individuals, they demonstrated significant bactericidal activity for I.M. penicillin, streptomycin, methicillin, kanamycin, irregularly with peroral erythromycin; chloramphenicol and tetracylines were bacteriostatic. Gross discrepancies were found with amphicillin, staphylomycin and fucidin.