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Biomedical subjects

J Donckier

Publications and source records attributed to J Donckier.

At least 91 records · Page 5Linked to original sources
PubMed1989

Prevention of acute cyclosporine nephrotoxicity by atrial natriuretic factor after ischemia in the rat.

The present experimental study investigates whether the atrial natriuretic factor (ANF) is able to prevent the nephrotoxic effects of cyclosporine infused after 30 min of warm renal ischemia in the rat. At 2 hr after the end of ischemia, the glomerular filtration rate was improved by an ANF infusion: 390 +/- 19 microliters/min/100 g versus 298.3 +/- 31 microliters/min/100 g in ANF and saline-infused rats, respectively (P less than 0.05). Intravenous CsA infusion at a dose of 2.5 mg/kg/day produced a more pronounced fall in GFR when compared with the control: 205.4 +/- 19.7 microliters/min/100 g versus 298.3 +/- 31 microliters/min/100 g in CsA and saline, respectively (P less than 0.05). In contrast, a synthetic rat atriopeptin III (0.5 microgram/kg/min) infusion after ischemia given together with CsA prevented its deleterious effects upon GFR: 316 +/- 22 microliters/min/100 g versus 205.4 +/- 19 microliters/min/100 g in ANF/CsA versus CsA alone (P less than 0.001). Moreover, the natriuretic ANF effects remained unaffected by high plasma CsA peak levels: indeed, other parameters of renal function--urinary flow, urinary sodium concentration and excretion rates, and urinary sodium reabsorption and fractional excretion rates, were significantly increased in ANF alone or CsA/ANF groups. These preliminary results suggest that ANF may be useful in renal transplantation or in the management of patients given large doses of CsA (liver or heart transplant) since, despite nephrotoxic CsA levels (greater than 1500 ng/ml), ANF provides an improved GFR and tubular function after ischemia.

Acute Kidney Injury↗
PubMed1988

Beneficial effect of atrial natriuretic factor on ischemically injured kidneys in the rat. A new approach to improve early renal function.

In a rat experimental study we investigated whether the atrial natriuretic peptide by itself is able to improve early renal function after an ischemic injury. Two groups of Wistar male rats underwent a right nephrectomy and a left renal artery occlusion for 30 min and were infused for 2 hr after ischemia with isotonic saline or rat atrial natriuretic peptides (alpha ANF: 28 amino acids (AP 28) and atriopeptin III (AP 24): 24 amino acids). ANF infusion increased the urinary flow (P less than 0.001), the urinary sodium concentration (P less than 0.001), the sodium excretion rate (P less than 0.0001), and improved the glomerular filtration rate (GFR) recovery (P less than 0.02) determined at the end of the 2-hr infusion period. AP 24 exhibited higher natriuretics activities than AP 28. The effect of both peptides upon GFR recovery was equivalent. These effects of ANF observed after acute ischemia suggest that this peptide may be beneficial on the resumption of renal function in the early phases following transplantation.

Animals↗
PubMed1987

Atrial natriuretic peptide: evidence of action as a natriuretic hormone at physiological plasma concentrations in man.

The administration of exogenous atrial natriuretic peptide (ANP) causes a natriuresis and diuresis in man, but this has, to date, only been demonstrated at plasma ANP concentrations within the high pathological or pharmacological ranges. Evidence that ANP acts physiologically requires the demonstration of a natriuretic effect when it is infused to recreate plasma concentrations similar to those observed after physiological stimuli. We infused human alpha-ANP (1-28) at a calculated rate of 1.2 pmol min-1 kg-1 for 3 h into seven water-loaded normal subjects, achieving plasma ANP concentrations within the upper part of the physiological range. The subjects' resting plasma ANP concentration increased from 3.8 +/- 1.5 to 20.9 +/- 1.9 pmol/l. The infusion of ANP caused a 60% increase of mean urinary sodium excretion from 111 +/- 18 to 182 +/- 30 mumol/min (P less than 0.001) and a 28% increase of mean water excretion from 10.8 +/- 0.8 to 13.8 +/- 1.6 ml/min (P less than 0.01). The infusion suppressed mean plasma renin activity from 1.55 +/- 0.10 to 1.17 +/- 0.06 pmol of ANG I h-1 ml-1 (P less than 0.001). Mean plasma aldosterone concentration (242 +/- 16 basally and 215 +/- 15 pmol/l at the end of ANP infusion) did not change significantly. Pulse rate and blood pressure were unchanged throughout the study. No significant change in any of the variables mentioned above occurred during the infusion of the vehicle alone on a separate study day.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1986

The plasma release of atrial natriuretic peptide in man.

We studied plasma atrial natriuretic peptide (ANP) concentrations in seven normal subjects after the acute intravenous infusion of sodium chloride/potassium chloride solution (saline). Three separate infusions of 6, 12 and 18 ml of saline/kg body weight each significantly increased the circulating concentration of ANP without changes of plasma osmolality or electrolyte concentrations. The mean maximal rise of the plasma ANP concentration after the three saline infusions was significantly correlated (r = 0.74, P less than 0.001) with, but occurred 10-30 min later than, the maximal atrial pressure rise. These observations are in accord with the hypotheses that: (a) ANP is a circulating natriuretic factor; (b) atrial distension is an important stimulus to ANP release in man.

Adolescent↗
PubMed1985

Gastric acid and pancreatic polypeptide responses to sham feeding are impaired in diabetic subjects with autonomic neuropathy.

To assess the relationship between cardiac and extra-cardiac dysfunction in diabetic autonomic neuropathy, the gastric acid output and the pancreatic polypeptide (hPP) secretion in response to sham feeding were evaluated in diabetic patients with (group 1) and without (group 2) cardiac autonomic neuropathy (CAN), and in normal subjects (group 3). All patients assigned to the group with CAN exhibited an impaired beat-to-beat heart rate variation during deep breathing. The basal gastric acid output was comparable in the three groups (1.3 +/- 0.5, 2.8 +/- 1.5, and 3.9 +/- 1.5 mmol/h, respectively). In contrast, the gastric acid output stimulated by sham feeding was significantly lower in patients with CAN (5.3 +/- 1.3 mmol/h) than in diabetic subjects without CAN (14.0 +/- 3.5 mmol/h; P less than 0.01) and in controls (10.9 +/- 3.1; P less than 0.05). The maximal gastric acid secretion capacity, determined after pentagastrin injection, was similar in all patients. Mean basal hPP concentrations were comparable in the three groups (185 +/- 53 pg/ml, 131 +/- 29 pg/ml, and 116 +/- 19 pg/ml). In the controls and diabetic subjects without CAN, a significant mean 60% increase of the hPP levels above basal values was observed during sham feeding. In contrast, no significant hPP response occurred in the group with CAN. These data suggest that diabetic CAN is associated with dysfunctions of the vagal pathways controlling the gastric acid output and the hPP secretion. Moreover, the results demonstrate a strong association between cardiac autonomic neuropathy and gastric vagal neuropathy (P less than 0.001).

Adult↗
PubMedDate not supplied

Influence of age on the clinical presentation of prolactinomas in male patients.

OBJECTIVE: Secreting pituitary adenomas are usually not considered a disease of older people. However, in male patients, prolactin-secreting pituitary tumours occur at a similar frequency throughout the entire life span, giving the opportunity to study in this gender the influence of age on the clinical presentation and response to treatment of these tumours. METHODS: We conducted a retrospective study including 9 male patients aged >/=60 (range 60-73) years and 10 aged </=30 (range 17-30) years presenting with a prolactinoma in order to compare clinical presentation, results of pituitary function tests, and response to dopamine agonist therapy between older and younger patients. RESULTS: Four of the 9 elderly as well as the 10 younger patients came to medical attention for typical features of male prolactinomas including visual field defect in 5 (2 elderly), headaches in 2 (1 elderly), impotence in 3 (1 elderly), gynaecomastia and/or galactorrhoea in 2, and arrested puberty in 2. The remaining 5 older people presented for other various reasons: symptoms related to cortisol deficiency in 2, lethargy with clinical signs of hypopituitarism in 1, spontaneous multiple vertebral fractures in 1, and incidental discovery of a pituitary mass in 1. Basal prolactin levels (3,051+/-4,151 vs. 3,365 +/- 4,949 microg/l) and mean tumour diameter (30 +/- 16 vs. 25 +/- 13 mm) were similar in old and young patients. Cortisol deficiency was significantly more frequent in the elderly (n = 6) than in the young (n = 1) patients (p 0.02, Fisher's exact test). Secondary hypothyroidism was found in 2 elderly only, but not in young patients. Sixteen patients (8 elderly) received bromocriptine therapy for at least 6 months with a good tolerance. Normalization of the prolactin levels was achieved in 6 older (75%) and 4 younger patients (50%). CONCLUSIONS: The presentation of a prolactinoma in the elderly man is very heterogeneous and can be misleading. At the time of diagnosis, hypopituitarism is more frequent among older than younger patients despite a similar tumour size. We found dopamine agonists equally effective in the elderly.

Adolescent↗
PubMedDate not supplied

Metabolic (glycaemic, lipidic) and blood pressure control in 101 type 2 diabetic patients on first admission to diabetes centres.

The aim of our study was to analyse the quality of metabolic and blood pressure control in a cohort of 101 patients with type 2 diabetes (54 males; 47 females), previously followed in primary care settings and admitted for the first time to the diabetes centres of Saint-Luc (n=66) or Mont-Godinne (n=35) University Hospitals. Age and (known) duration of diabetes were 64 +/-12 and 6 +/- 7 years (mean +/- SD), respectively. Body mass index was 31 +/- 7 kg/m2. Systolic and diastolic blood pressures were 140 +/-12 and 81 +/-11 mmHg. Homeostasis model assessment (HOMA) showed insulin sensitivity at 63 +/-32% and P-cell function at 49 +/- 44% (n=34). Forty-seven percent of patients received either diet alone or combined with an oral antidiabetic monotherapy. Seven-teen percent of all patients were on insulin monotherapy or associated with oral drugs. HbAlc was 9.0 +/- 2.3%, with 22% of patients within HbAlc targets of < or = 7%. Only a subset of patients reached international targets of care in terms of blood pressure and lipidic profile, despite antihypertensive and lipid-lowering agents in 62% and 36% of patients, respectively. Forty-five percent of individuals had at least one diabetes-related long-term complication. In view of this unsatisfactory control, our results suggest that "anti-diabetic" treatment should be intensified earlier in primary care settings.

Aged↗