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Biomedical subjects

G Gyódi

Publications and source records attributed to G Gyódi.

12 recordsLinked to original sources

Urinary excretion of endogenous ouabain-like substance is reduced in NaCl supplemented premature infants.

Ouabain or an isomer has been identified as endogenous ouabain-like substance (EOLS). The role of EOLS in the adaptation of premature infants to alterations of sodium balance was investigated by measuring urinary ouabain excretion serially in 9 low birth weight premature infants with (group S, mean birth weight 1,578 g, mean gestational age 30.4 weeks) and without (group NS, mean birth weight 1,537 g, mean gestational age 30.8 weeks) NaCl supplementation. The study was performed on the 7th day and weekly thereafter until the 5th week of life. NaCl supplementation was given in a dose of 3-5 and 1.5-2.5 mmol/kg/day at the postnatal ages of 8-21 and 22-35 days, respectively. Prior to NaCl supplementation, urinary ouabain excretion was similar in the two groups (146.2 +/- 16.8 pg/kg/h in group S versus 180.0 +/- 9.6 pg/kg/h in group NS) and remained at about the same level throughout the study when supplemental NaCl was provided. In infants of group NS, urinary ouabain excretion increased significantly by the 3rd week (p < 0.01) and no consistent change occurred later on. As a result, the differences in urinary ouabain excretion between the two groups proved to be significant during weeks 2-5 (p < 0.001). Essentially the same pattern of ouabain excretion was seen when it was expressed in terms of pg/mg creatinine. In infants receiving high sodium diet there was a significant positive correlation between urinary sodium and ouabain excretion. It is concluded that premature infants receiving low sodium intake have elevated EOLS excretion by the 3rd week of life. Although the relationship between ouabain and sodium excretion in supplemented premature infants suggests some physiological significance for sodium excretion, ouabain does not appear to be regulated by extracellular volume.

Cohort Studies↗

Effect of sodium chloride supplementation on urinary endothelin-1 excretion in premature infants.

We investigated the role of endothelin-1 in the renal adaptation to alterations in sodium balance in premature infants. The postnatal course of urinary endothelin-1 excretion, an estimate of renal endothelin-1 production, was compared in premature infants receiving low or high sodium intake. Sodium supplementation was given in a dose of 3 to 5 mmol/kg per day and 1.5 to 2.5 mmol/kg per day at the postnatal ages of 8 to 21 and 22 to 35 days, respectively. Sodium balance and urinary endothelin-1 excretion were determined weekly up to the fifth week of life. Urinary endothelin-1 concentration (expressed in picomoles per liter) and urinary endothelin-1 excretion (expressed either in terms of picomoles per square meter per day or picomoles per millimole creatinine) were significantly lower in infants receiving a high sodium intake compared with those receiving low sodium intake (p < 0.001) in weeks 2 through 5. We conclude that in sodium-depleted premature infants with high urinary sodium excretion, an angiotensin II-mediated increase in renal endothelin-1 production occurs, which acts in concert with angiotensin II to restore sodium balance.

Endothelins↗

Postnatal course of plasma levels of adrenocortical steroids in premature infants with and without NaCl supplementation.

To assess the adrenocortical response of premature infants to alterations in sodium balance, the postnatal course of plasma progesterone, 11-deoxycorticosterone, corticosteronoe, aldosterone, 17-hydroxyprogesterone, 11-deoxycortisol, cortisol and cortisone was compared in healthy premature infants kept on low (1-2 mEq/kg per day) or high (3-5 mEq/kg per day) sodium diet. The mean birthweight (1470 g, range: 1210-1670 g vs 1410 g, range: 1130-1750 g) and mean gestational age (30.5 weeks, range: 29-32 weeks vs 30.2 weeks, range: 28-32 weeks) in the low and high sodium groups, respectively, were similar. Simultaneous steroid hormone measurements were made weekly up to the 5th week of life using mechanized Sephadex LH-20 multicolumn chromatography and standardized radioimmunoassays. It was demonstrated that in response to renal salt wasting and negative sodium balance there was a significant rise in plasma aldosterone concentration. The plasma levels of other individual corticosteroids generally declined with advancing age, the initial fall, however, was followed by a transient and insignificant but simultaneous increase in 11-deoxycortisol, cortisol, cortisone and corticosterone in prematures on low a sodium diet. This effect could be prevented by giving NaCl supplement. The NaCl-suppressible increase in adrenocortical activity may be the result of the combined effect of stress or angiotensin 11-induced adrenocorticotropic hormone (ACTH) release and/or prolactin-mediated enhanced adrenal response to ACTH.

17-alpha-Hydroxyprogesterone↗

The influence of NaCl supplementation on the postnatal development of urinary excretion of noradrenaline, dopamine, and serotonin in premature infants.

The present study was designed to investigate the role of noradrenaline (NA), dopamine (DA), and serotonin (5-HT) in the adaptation of premature infants to alterations of sodium balance. Urinary excretion of NA, DA, and 5-HT was measured spectrofluorimetrically in a group of low birth weight premature infants with (group S) and without (group NS) NaCl supplementation. Group NS consisted of 10 infants with a birth weight of 1200-1750 g (mean, 1493 g) and gestational age of 28-31 wk (mean, 30.1 wk). Group S included 10 infants with mean birth weight of 1414 g (range, 1150-1600 g) and mean gestational age of 30.5 wk (range, 27-32 wk). Measurements were made on the 7th day and weekly thereafter until the 5th wk of life. NaCl supplementation was given in a dose of 3-5 and 1.5-2.5 mEq/kg/day for 8-21 and 22-35 days, respectively. In group NS, mean urinary excretion of NA and DA increased from 8.6 +/- 1.5 and 15.8 +/- 2.4 micrograms/day to maximum values of 21.4 +/- 5.5 (p less than 0.05) and 33.4 +/- 6.0 micrograms/day (p less than 0.01) in weeks 2-3, respectively. 5-HT excretion averaged about 60 micrograms/day and showed no consistent change during the course of the study. NaCl supplementation prevented the rise of NA and DA excretion above the initial baseline values. The postnatal course of 5-HT excretion, however, remained unaffected by NaCl supplementation. Urinary excretion of NA in weeks 2-3 (p less than 0.05) and DA in weeks 2-4 (p less than 0.05) were significantly lower in group NS.

Dopamine↗

Blood coagulation in healthy and severely ill newborn infants.

Normal values of blood coagulation factors were investigated in 30 healthy newborn infants. On the basis of these normal standards 8 infants with DIC were evaluated. All of them had serious underlying diseases. By appropriate treatment of the primary disorder and replacement of depleted procoagulants, the bleeding disorder disappeared in six of eight patients without heparinization. Diagnostic criteria and management of neonatal disseminated intravascular coagulation are discussed.

Blood Coagulation↗