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Biomedical subjects

C A Gaillard

Publications and source records attributed to C A Gaillard.

59 records · Page 4Linked to original sources

Enhanced natriuretic effect of atrial natriuretic factor during mineralocorticoid escape in humans.

We examined the question of whether escape from the sodium-retaining effect of mineralocorticoid involves an increased natriuretic effect of atrial natriuretic factor (ANF). Seven healthy volunteers taking a 170 mmol Na/100 mmol K diet received an intravenous bolus (25 micrograms) followed by a 1-hour infusion (0.02 micrograms/kg/min) of ANF (human ANF-[99-126]) before and after 10 days of 9-fludrocortisone acetate, 0.5 mg b.i.d. Escape was accompanied by an increase in body weight (from 72.2 +/- 12.9 to 74.0 +/- 12.6 kg; p less than 0.05), mean arterial pressure (from 95 +/- 4 to 109 +/- 3 mm Hg; p less than 0.01), plasma ANF (from 9 +/- 2 to 24 +/- 4 pmol/L; p less than 0.01), and inulin clearance (from 124 +/- 9 to 137 +/- 7 ml/min; p less than 0.05). Indexes for renal sodium handling (lithium and free water clearance) were compatible with a decreased "proximal" and an increased "distal" tubular reabsorption fraction. ANF infusion raised inulin clearance comparably before and after escape to 138 +/- 10 and 152 +/- 7 ml/min, respectively, but the natriuretic effect was much larger (p less than 0.05) after escape (from 366 +/- 34 to 1294 +/- 278 mumol/min) than before (from 248 +/- 48 to 630 +/- 124 mumol/min). Indexes for tubular reabsorption were consistent with greater suppression of both "proximal" and "distal" tubular sodium reabsorption by ANF after versus before mineralocorticoid expansion. These results indicate that escape is accompanied not only by a rise in plasma ANF but also by potentiation of the natriuretic effect of ANF.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

Effects of indomethacin on renal response to atrial natriuretic peptide.

We studied the effect of alpha-human natriuretic peptide (ANP, 100 micrograms iv) on renal sodium handling in eight healthy subjects before and after 7 days of indomethacin (50 mg 3 times a day). Sodium intake was 100 mmol/day. Prior to indomethacin, ANP caused a fourfold rise in sodium excretion over the first 20 min and a threefold rise in fractional sodium excretion. The clearance studies, performed during maximal water diuresis, showed increased fractional free water clearance and lithium clearance. Indomethacin caused marked sodium retention. Complete escape did not occur until the sixth day, when cumulative balance was 244 mmol (range 176-337). By this time renin and aldosterone were suppressed and fractional lithium and free water clearance reduced. The natriuretic effect of ANP was not attenuated, and the fractional excretion of sodium and chloride rose even more than without indomethacin. The reduction in lithium and free water clearance under indomethacin tended to be reversed by ANP. These data suggest that the natriuretic effect of ANP is not mediated by or dependent on renal prostaglandins. Indomethacin and ANP appear to have opposite effects on sodium excretion, maximal free water clearance, and lithium clearance.

Adult↗

Renal response to atrial natriuretic peptide in nephrotic syndrome.

In six patients with nephrotic syndrome of various aetiology, the increase in absolute and fractional sodium excretion (FENa) after a bolus injection of 100 micrograms alpha-human atrial natriuretic peptide (ANP) was not different from the effect in normal healthy subjects at comparable sodium levels. Glomerular filtration rate rose in normals as well as in patients. In two patients, however, baseline sodium excretion was very low and the natriuretic response to ANP was proportionally blunted. The high baseline sodium reabsorption and blunted response to ANP may be explained as due either to an intrinsic renal defect or to a circulatory hypovolaemia. The finding of a low plasma ANP in these two patients, however, suggests involvement of a hypovolaemic component.

Adult↗

Topical antimicrobial prophylaxis of nosocomial pneumonia in mechanically ventilated patients. Microbiological observations.

Generally, reduction of colonization and infection with potentially pathogenic microorganisms in intensive care units (ICU) is attempted by a combination of antimicrobial agents administered topically in the digestive tract and systematically. We tested the efficacy of topical antimicrobial prophylaxis of the oropharynx and stomach administered in combination with sucralfate without systemic prophylaxis in 25 mechanically ventilated ICU patients. The regimen successfully reduced colonization with potentially pathogenic microorganisms in the oropharynx and trachea without modifying the intestinal flora. However, colonization and infections with gram-positive cocci and gram-negative rods other than Enterobacteriaceae and Pseudomonadaceae and resistant to one or both the antimicrobial agents used were observed.

Administration, Intranasal↗