PubMed HealthSearch

Biomedical subjects

H Brauman

Publications and source records attributed to H Brauman.

At least 19 recordsLinked to original sources

Indirect evidence of glomerular/tubular mixed-type postexercise proteinuria in healthy humans.

Hypothetical mechanisms have been postulated to explain the presence of proteins in urine after severe exercise. Recently, it has been shown that several amino acids inhibit tubular protein reabsorption. Seven healthy men, hyperhydrated, were studied during a 2-min bicycle exercise at supramaximal load. The subjects were tested without or with lysine perfusion (0.4 g/kg body wt iv). In both testing conditions, blood lactate increased to 13.8 mmol/l. Total protein urinary excretion increased to 1.10 and 1.67 mg/min, without and with lysine perfusion, compared with 79 micrograms/min at rest. In the meantime, albumin excretion increased 48- and 74-fold, respectively, while beta 2-microglobulin excretion increased 97- and 1,043-fold compared with basal values. The renal clearance of albumin increased to 8.4 microliters/min without lysine and to 12.0 microliters/min with lysine perfusion (rest 0.18). beta 2-Microglobulin clearance increased to 10.0 and 39.3 ml/min, respectively (rest 0.05). These data clearly demonstrate that postexercise proteinuria is of mixed type after exhaustive short-term exertion. Both increased glomerular permeability and partial tubular reabsorption inhibition to proteins appear to be involved.

Adult

[Comparative study of the diagnostic contribution of C-terminal and medio-regional determination of parathyroid hormone in man].

In this study, we compared serum parathyrin radioimmunoassay values obtained with three commercially available kits in a series of normal subjects, patients on dialysis, patients with primary hyperparathyroidism and with hypercalcemia due to malignancy. The calcium of these subjects was simultaneously evaluated. Two of these three kits measure two different C-terminal portions of the molecule and the third the mid region of PTH. The Behring and Byk kits were most efficient in that the results were obtained rapidly. The mid region assay is not more contributive than the C-terminal assays. Among these, the Behringer kit seems to produce the best diagnostic discrimination when the PTH and calcium are coupled. As far as the diagnostic specificity is considered, the latter kit seems however less efficient than the two others.

Chemical Phenomena

Relative contribution of various expressions of cAMP excretion to other indices of parathyroid function, as tested by discriminant multivariate linear regression analysis.

We evaluated the relative contribution to the diagnosis of hyperparathyroid disease from current laboratory indices of parathyroid function--plasma calcium (I), phosphate (II), carboxy-terminal (III) and predominantly amino-terminal (IV) radioimmunoassays of parathyrin, the urinary excretion ratios of cyclic adenosine monophosphate (cAMP) to creatinine (V) or to glomerular filtrate (VI), and the ratio of the nephrogenous fraction of cAMP to glomerular filtrate (VII)--in 224 subjects: 40 with surgically proven hyperparathyroid disease, the others normoparathyroid. The decreasing order of sensitivity was I greater than VI greater than VII greater than V greater than III greater than IV greater than II; all these indices differed significantly between normoparathyroid and hyperparathyroid patients. The decreasing order of specificity was VII, III greater than I greater than IV greater than V, II greater than VI. Discriminant multivariate linear regression analysis was performed in a subset of 58 subjects (17 hyper- and 41 normoparathyroid) from the population studied here, chosen because all of the laboratory indices were determined for each subject. The classification accuracy was 98.3% for combining I, VII, and III (r = 0.908), or I and V (r = 0.893), or I and VII (r = 0.889). The other variables did not add to the precision of classification.

Adult

Magnesium administration reverses the hypocalcaemia secondary to hypomagnesaemia despite low circulating levels of 25-hydroxyvitamin D and 1,25-dihydroxy vitamin D.

The effect of parenteral administration of magnesium was studied in five patients with hypomagnesaemic hypocalcaemia. The initial metabolic state was characterized by a normal level of serum immunoreactive parathyroid hormone (iPTH), and by low or undetectable serum 25-hydroxyvitamin D (25OHD) and 1,25-dihydroxyvitamin D (1,25 (OH)2D). A parathyroid response was elicited by the acute intravenous injection of magnesium chloride. In contrast, 1,25(OH)2D did not change up to 24 h after the injection. Intramuscular magnesium sulphate restored serum magnesium and calcium to normal, whereas iPTH was transiently increased. 25OHD remained low and unchanged. 1,25(OH)2D rose very slowly, but the correction of hypocalcemia began before any change in 1,25(OH)2D levels could be demonstrated. Thus, the early correction of hypocalcemia mainly depended on the restoration of an adequate parathyroid function independently of the secretion of 1,25(OH)2D.

25-Hydroxyvitamin D 2

Disturbed mineral metabolism in hyperthyroidism: good correlation with tri-iodothyronine.

Mineral metabolism is frequently disturbed in hyperthyroidism. In a group of seventy-two patients with hyperthyroidism, we observed an increase in serum diffusible calcium in 50% of the cases, elevated inorganic phosphorus in 30% and elevated alkaline phosphatase in 44% of the cases. Correlations existed between the values of diffusible calcium, inorganic phosphorus, alkaline phosphatase and certain indices of thyroid function (T4, FT41, T3, FT3I), of which that with T3 was the best (P less than 0.001). Our results suggest that the magnitude of the disturbances of mineral metabolism depends on the severity of the hyperthyroidism and that it is the T3 level that constitutes the best index of that severity.

Adolescent

Effect of rapid variation of renal function on plasma calcitonin and parathyroid hormone in man.

Plasma levels of immunoreactive calcitonin (iCT) and parathyroid hormone (iPTH) have been measured sequentially in 6 patients following successful renal transplantation (RT) and in 3 patients during the recovery phase of acute renal failure (ARF). iCT and iPTH returned to normal values within a few days when glomerular filtration improved; both hormones rose in cases of acute graft rejection. Unlike iPTH iCT did not follow closely the variations of creatinine, iCT even rising before creatinine in one graft rejection. These observations could possibly be explained by a dissociation between the renal metabolism of iCT and the glomerular filtration.

Acute Kidney Injury

Cardiovascular effects of methyl methacrylate monomer.

Although cardiorespiratory human sensitivity to circulating methyl methacrylate monomer remains unknown, it is clear that the blood levels responsible for cardiocirculatory alterations in intact dogs are not obtained after insertion of acrylic cement in long bones in clinical practice. Circulating monomer considered as the sole causal factor for the hemodynamic changes described during orthopedic method is highly questionable.

Animals

Parathyroid hormone-like biological activity in urine.

1. The parathyroid hormone-like biological activity of concentrated urine was measured by the increase of plasma calcium concentration after intravenous injection of the sample into chickens. 2. Urine was tested in hypoparathyroid patients, normal volunteer subjects, primary hyperparathyroid patients before and after surgery and patients with secondary hyperparathyroidism. 3. In primary and secondary hyperparathyroidism the biological activity was significantly higher than in urine from normal subjects, which was in turn significantly higher than the activity in the urine of hypoparathyroid patients. This bioactivity diminished after surgical removal of a hyperparathyroid adenoma. 4. Decreased activity after trypsinization indicated the peptidic nature of the hypercalcaemic substance.

Animals

Plasma and urinary levels of beta2 microglobulin in rheumatoid arthritis.

Plasma and urinary levels of beta2 microglobulin have been investigated in 21 patients suffering from rheumatoid arthritis (RA). Despite a normal renal glomerular function in all patients 50% of them had supranormal plasma beta2 microglobulin levels and 30% had a higher than normal urinary output of beta2 microglobulin generally related to the high plasma level. Plasma beta2 microglobulin levels paralleled closely the lymphocytosis and the 'joint count' both indexes of the severity of the disease. beta2 Microglobulin was normally secreted by the lymphoid tissue and it is suggested that it reflects the increase of the total mass and/or membrane turnover of the lymphoid tissue in RA. beta2 Microglobulin may be considered as a good parameter of the degree of severity of the joint and extra-articular involvement as well as a useful tool for the evaluation of drug efficacy in rheumatoid arthritis.

Adult

Parathyroid hormone and calcium blood levels in acute renal failure. With special reference to one patient developing transient hypercalcemia.

Parathyroid hormone (PTH), creatinine, calcium and phosphate blood levels were repeatedly measured in 5 patients with acute renal failure. 1 patient developed hypercalcemia during the recovery phase of the illness. PTH was elevated in all cases before starting hemodialysis treatment and returned to normal when renal function recovered. Calcium and PTH were inversely correlated in 3 patients including the patient with transient hypercalcemia. These data show that parathyroid function in acute renal failure is closely related to changes in renal function and the hypercalcemia, when occurring, is not necessarily due to parathyroid hyperactivity.

Acute Kidney Injury

[beta2-Microglobulin in renal transplanted patients (author's transl)].

Plasma beta2m has been measured frequently during long term follow-up of kidney transplanted outpatients. The ratio of beta2m/log creatinine was abnormally high in 15 patients of this series bearing a symptomatic hepatitis independently of any modification of immunodepressive drug administration schedule (azathioprine and corticoids). The true effect of azathioprine could not be isolated whereas corticotherapy modified clearly the beta2m/creatinine ratio : increase of dosage for rejection resulted in a fall of the ratio whereas fast reduction increased the ratio acting essentially on circulating beta2m level (12 cases). The beta2m/creatinine ratio was normal or occasionally diminished in the 22 patients having an uneventful clinical course. Six patients showed mixed effects of hepatitis and variation of corticoid dosage and 7 cases were too much intricated to permit a good analysis of the data.

Adrenal Cortex Hormones

[beta2-Microglobulin in synovial fluid (author's transl)].

In a series of patients with rheumatoid arthritis we found higher levels of synovial beta2-microglobulin (5,2 +/- 3 mg/l) than in gouty arthritis (2,4 +/- 0,6) or osteoarthritis (1,2 +/- 0,3 mg/l). The ratio of synovial/plasma beta2-microglobulin was always superior to unity (2,3 +/- 0,7) in the R.A. patients whereas it is always inferior to unity in the other groups. The correlation between plasma or synovial beta2-microglobulin and synovial lymphocyte count was highly significant in all cases in RA patients plasma and synovial beta2-microglobulin are significantly related to the degree of joint involvement as expressed by the joint count.

Arthritis, Rheumatoid