Biomedical subjects

M Rainfray

Publications and source records attributed to M Rainfray.

42 records · Page 3Linked to original sources

PubMed1984

Effects of an acute calcium load on plasma ACTH, cortisol, aldosterone and renin activity in man.

Plasma adrenocorticotrophin (ACTH), cortisol and aldosterone increased during and after iv administration of calcium gluconate in 4 normal subjects, one patient with hypoparathyroidism and one patient with hypothyroidism. On the other hand, there was a decrease in plasma renin activity but only in the normal subjects. Plasma ACTH and cortisol responses to calcium were abolished whereas plasma aldosterone response persisted in 2 normal subjects pre-treated with dexamethasone. The results observed after calcium administration were compared to those observed after infusion of the solvent only in 6 normal subjects and 4 thyroidectomized patients who were studied twice at 3 day intervals. Plasma ACTH, cortisol and aldosterone were higher when calcium was administered. Plasma renin activity was not statistically different whether or not calcium had been injected in the subjects studied twice. These results demonstrate a direct effect of calcium on ACTH and aldosterone secretion which is not mediated by calcitonin and parathyroid hormone. The stimulatory effect of calcium on cortisol secretion depends on the increase in plasma ACTH.

Adrenocorticotropic Hormone↗

PubMed1982

Metabolic clearance rate of immunoreactive vasopressin in man.

Metabolic clearance of synthetic arginine vasopressin (AVP) has been measured in sixteen healthy subjects and ten uraemic patients on maintenance haemodialysis. Plasma AVP was measured using a specific radioimmunoassay at different intervals after a single injection of 2 micrograms AVP. The theoretical curve which fitted best with the disappearance curve was the sum of two exponentials in twenty-two subjects and of three exponentials in the other four. Metabolic clearance rate and the volume of fast initial distribution were 287.1 ml min-1 (m2)-1 and 219.3 ml/kg b.w., respectively, in normal subjects. Metabolic clearance rate was considerably lower in the uraemic group. This emphasizes the role of kidneys in the degradation of AVP and may account, at least in part, for the higher basal plasma value of this hormone observed in uraemic patients.

Adult↗

PubMed1980

[Tuberous sclerosis with chronic renal failure treated by hemodialysis and transplantation (author's transl)].

We report on a case of tuberous sclerosis in a 36-year-old female with chronic renal failure, who was treated by hemodialysis and transplantation. The diagnosis of tuberous sclerosis was ascertained by the association of typical cutaneous retinal and osseous lesions. On the contrary, the renal localisations were unusual. Early hypertension was exacerbated in the course of 2 pregnancies but was never severe. It preceded the late onset of renal failure which progressed slowly. The kidneys were small, with a peculiar angiographic aspect: the renal tissue was not invaded by hamartomas but the whole arterial bed was diffusely modified, with a cortical perfusion defect. Both kidneys were studied after bilateral nephrectomy. The lesions were far more complex than a simple replacement of the renal tissue by angiomyolipomas: they involved the vessels, the interstitium (with lipids inclusions surrounded by a macrophagic reaction) and the glomeruli (with focal and segmental sclerosis). This observation (which is the 11th case in the literature of tuberous sclerosis with chronic renal failure and the 3rd treated by transplantation) documents a particular variety of congenital and familial nephropathy with delayed revelation.

Adult↗

PubMedDate not supplied

[Effects of aging on kidney function and implications for medical practice].

PHYSIOLOGICAL AGING: Anatomical and physiological renal changes occur during normal aging in humans. These changes are different from the renal effects of many diseases frequently linked to aging and which require specific diagnosis, prevention and therapy. Renal aging varies from one patient to another or from one population to another. During common aging, anatomical changes are mild and physiological changes mainly affect glomerular filtration rate and water and salt metabolism regulation. IN THE ELDERLY: Glomerular filtration rate decreases slowly in healthy elderly people to reach 80 ml/mn at 80 years without any metabolic consequence. However, in old hospitalized patients, acute renal failure is frequent and occurs mainly during inflammatory or infectious disorders, dehydration or drug combinations enhancing regulation of glomerular filtration. Tubular function changes expose the elderly to increasing risk of dehydration which could be prevented in highly predictable situations such as gastrointestinal symptoms, poorly salted diets or anorexia. Estimation of the creatinine clearance is necessary whenever an acute medical events, mostly infectious diseases, occur in elderly people to adapt drugs doses to renal catabolism.

Acute Kidney Injury↗

PubMedDate not supplied

Early changes in isokinetic lower limb muscle strength in recovering geriatric subjects on the basis of nutritional status.

BACKGROUND: In older people, the decrease in muscle mass and strength has a bad effect on functional status. Malnutrition and lack of physical activity exacerbate this phenomenon. OBJECTIVE: The main purpose of this study was to estimate isokinetic lower limb muscle strength in recovering older subjects on the basis of nutritional status. DESIGN: Twenty-eight elderly subjects hospitalized for an acute event (85.8 +/- 6 years), including 16 malnourished, were enrolled in this study when clinically stable (T0). Re-assessment at one-month was performed in nine after oral supplementation and conventional physiotherapy (T1). The Maximal Peak Torque (MPT) of the ankle plantar flexors was estimated in concentric mode at 30 and 60 degrees /s. The MPT of the knee flexors and extensors was evaluated in the same mode at 30 degrees /s, 60 degrees /s and 120 degrees /s. All patients underwent a nutritional examination with anthropometric measures, dietary intake survey, biochemical indexes and determination of the medial gastrocnemius volume by magnetic resonance imaging. RESULTS: At T0, whatever the muscle group tested (except at 120 degrees /s for the knee), the MPT appeared significantly lower in the malnourished group. At T1, the increase in MPT (plantar flexors) in malnourished patients was greater at 60 degrees /s (+23.8 %) than at 30 degrees /s (+14.8 %). Correlations between MPT and nutritional parameters were observed in the malnourished group only at T1 and in the normal-nourished group. CONCLUSION: Isokinetic assessment seems to be a pertinent method to estimate lower limb muscle strength in older and frail subjects. Early modifications in strength were observed in malnourished patients who received oral supplementation and physiotherapy.

Aged, 80 and over↗

PubMedDate not supplied

[Growth hormone in adults. An elixir of youth?].

Studies have revealed a partial deficiency of growth hormone (GH) secretion in the elderly. Aging has a central effect on the GH secretion and probably a peripheral effect on insulin-like growth factor 1 (IGF-1) or somatomedin C through changes in body composition. Simultaneously therapeutic efficiency of recombinant GH was confirmed in adults with GH deficiency. These notions have led to some controlled trials of GH treatment in elderly. Further studies of GH replacement are needed, examining issues such as dosage, tolerance (still inadequate) and efficacy before the widespread use of GH or IGH-F 1 in the elderly is advocated.

Adult↗