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Biomedical subjects

K Schultz

Publications and source records attributed to K Schultz.

At least 127 records · Page 7Linked to original sources
PubMed1977

Body size and neonatal hypoglycemia in intrauterine growth retardation.

The relationship between blood glucose and body physique of 233 (42 hypo-and 191 normologycemic) intrauterine growth-retarded neonates was analyzed using different body measurements and indices of body proportions. Classification by combination of weight and length deficit for fetal age revealed that the disproportionately retarded infants (deficit in weight for age > 30%; deficit in length for age less than equal to 15%) were particularly prone to hypoglycemia. The lowest incidence of hypoglycemia was observed in the group with severe proportionate retardation (weight deficit for age > 30%; length deficit for age > 15%). Among the indices of body proportions ponderal index (W/L3), and percentage deviation from the expected weight for length turned out to be a sensitive predictor of the risk of hypoglycemia. The majority of hypoglycemia neonates were underweight for length and a considerable number of normoglycemic infants were overweight for length. These findings point to the significance of soft tissue wasting rather than low birth weight for gestational age itself, in the development and diagnosis of neonatal hypoglycemia. The significance of anthropometry in the classification of different types of intrauterine growth impairment, as well as in predicting specific hazards after birth is discussed.

Anthropometry↗
PubMed1977

Ataxia and paralysis associated with bovine ephemeral fever infection.

Three adult cattle that had been ataxic for 5 to 7 months and a bull that had been paralysed for 24 days following bovine ephemeral fever infection were studied clinically and pathologically. Severe bilaterally symmetrical Wallerian degeneration was demonstrated in the spinal cords of all 4 cattle; in 3 animals an area of primary damage was present in the first cervical segment of the cord and in the other animal it was at the level of the lumbar cord. Pressure on the cord resulting from trauma was considered to be the most likely aetiology because of the similarity of the lesion to other syndromes causing pressure on the cord and the absence of the usual inflammatory changes seen with infectious agents.

Animals↗
PubMed1977

The effect of birth asphyxia on plasma free amino acids in preterm newborn infants.

The postnatal plasma amino acid pattern was compared in 16 asphyxiated and 13 non-asphyxiated preterm newborn infants. The lactic acidosis induced by asphyxia was associated with a marked rise in the total amino acid content of the plasma. Among the 17 individual amino acids determined the concentrations of alanine, proline, taurine, glutamate, valine, methionine and lysine were significantly elevated. The accumulation of alanine was particulary marked and its concentration showed a significant linear correlation with that of lactate (p less 0.001). A similar relationship was observed between other potentially glucogenic amino acids and lactate. It is suggested that an impaired gluconeogenesis may be responsible for the accumulation of glucogenic amino acids. The response of the plasma aminogram to asphyxia resembles that associated with hypoglycaemia in the small-for-gestational-age infant, where a delay in the maturation of key gluconeogenic enzymes seems to account for the reduced hepatic disposal of glucose precursors.

Alanine↗
PubMed1977

Transverse diameter of the chest and of the heart of infants in the course of physiological cardiorespiratory adaptation.

The morphology of the lungs and heart was analysed in 824 newborn infants with normal cardiorespiratory adaptation. Under normal conditions, the air content of the lungs became satisfactory in the first 6--12 hours and normal in all cases after 24 hours. The values for the transverse diameter of the chest and heart were brought into correlation with birth weight, body length and gestational age. The transverse diameter of the chest and heart did not change during the early postnatal period (between 6--12 hours and 5 days). Both diameters were correlated with birth weight. The closest correlation was found in newborns under 1500 g, a varying one in those between 1500 and 2000 g and a close correlation in the category over 2000 g. The correlation of the two diameters with both length was linear and close, without any difference between the values obtained at different times of examination. A rather loose correlation was found between the transverse diameter of the chest and heart, and gestational age.

Adaptation, Physiological↗
PubMed1976

Function and ultrastructure of platelets of neonates: enhanced ristocetin aggregation of neonatal platelets.

We have investigated platelet morphology and function in human maternal-newborn pairs. Fibrinogen concentration and factor-VIII activity in plasma were also determined. Our results showed that, compared to maternal platelets, neonatal platelets were poorly responsive to adenosine diphosphate, adrenaline and collagen. Uptake of labelled serotonin by neonatal and maternal platelets was the same, but release of the radioactivity was reduced in the former. Phagocytic activity of neonatal platelets, demonstrated with latex particles, was similar to that of maternal platelets. Although the ultrastructure of neonatal platelets approximated that of maternal platelets, immature appearing platelets were occasionally found in the neonatal samples. An unanticipated finding was that platelet aggregation induced by ristocetin was more vigorous in neonatal than in maternal platelet-rich plasma samples. Furthermore, neonal -lasma, which had lower fibrinogen and factor-VIII content than maternal plasma, facilitated maternal platelet aggregation by ristocetin and showed a greater ability than maternal plasma to promote ristocetin-induced aggregation of platelets of a patient with von Willebrand's disease. These results indicate that the plasma of neonates contains large quantities of the ristocetin-dependent platelet aggregation factor (RAF), probably more than is in maternal plasma, despite the higher levels of factor-VIII procoagulant activity in the latter. Thus, in the newborn, there is a clear dissociation between factor-VIII clotting activity and the RAF activity.

Blood Platelets↗
PubMed1976

The metabolic effects of glucagon infusion in normoglycaemic and hypoglycaemic small-for-gestational-age infants. I. Changes in blood glucose, blood lactate and plasma free fatty acids.

The response to glucagon infusion of blood glucose, blood lactate and plasma FFA was studied in 7 normoglycaemic and 7 hypoglycaemic SGA infants. The infants received glucagon at a rate of 0.2 microng/kg/min into a cephalic vein for a period of four hours. Glucagon caused a marked and significant rise in blood glucose in both groups; from 66 +/- 12 mg/100 ml to 136 +/- 16 mg/100 ml in the normoglycaemic, and from 22 +/- 2 mg/100 ml to 69 +/- 13 mg/100 ml in the hypoglycaemic infants. The time course of the response was different: while in the former group blood glucose declined after the second hour of glucagon infusion, in the hypoglycaemic group the response persisted throughout the test period. In the normoglycaemic SGA infants FFA fell rapidly in response to glucagon, whereas no significant change occurred in hypoglycaemic infants. The different baseline lactate concentrations were not affected significantly.

Blood Glucose↗
PubMed1976

The metabolic effects of glucagon infusion in normoglycaemic and hypoglycaemic small-for-gestational-age infants. II. Changes in plasma amino acids.

Altogether 17 individual amino acids were determined before and during glucagon infusion in normoglycaemic and hypoglycaemic SGA infants. The magnitude and time course of the response in total plasma amino acids to glucagon infusion (0.2 microng/kg/min for four hours) differed in the two groups: while in the normoglycaemic SGA infants a significant hypoaminoacidaemia was noted by the second hour of glucagon infusion, in the hypoglycaemic newborns no appreciable changes were observed. In the former group altogether twelve amino acids showed a progressive and significant decline. The fall of three important gluconeogenic amino acids alanine, glycine,proline, and that of three branched chain amino acids was particularly striking. In contrast, in the hypoglycaemic infants the amino acids were not significantly affected by glucagon infusion. This unresponsiveness of plasma amino acids was probably transient as judged from the moderate hypoaminoacidaemia noted by the end of the infusion period. The observations seem to have important implications regarding the influence of glucagon on hepatic glucose production, and its possible therapeutic importance in the management of hypoglycaemic intrauterine malnourished infants.

Alanine↗
PubMed1976

The elimination of free fatty acids, free glycerol and triglycerides from the plasma of low-birth-weight infants receiving intravenous fat emulsion and glucose.

The disappearance rate of plasma. free glycerol, free fatty acids and triglycerides following the termination of short-term (6-hr) infusion of fat emulsion (Intralipid) was studied in 12 low-birth-weight infants. The mean K values for each lipid component were found to be higher in infants receiving 10% glucose. Owing to the wide individual variation of responses and the small number of infants studied, only the disappearance rate of free fatty acids reached the level of significance. It is concluded that increased amounts of glucose given simultaneously with fat emulsion could diminish hyperlipidaemia by increasing the clearance of lipids from the plasma.

Dietary Fats↗
PubMed1976

Acid-base status and urinary hydrogen ion excretion pattern in low-birth-weight infants receiving intravenous fat emulsion and glucose.

The acidifying effect of short-term (6-hr) infusion of intralipid was studied in 12 low-birth-weight infants by following the changes in acidbase status and urinary H+ excretion pattern. The infants received 5% or 10% glucose as a base-line calorie supply. Intravenous fat emulsion induced a transient metabolic acidosis. The slightly affected pH and BE recovered in the first two hours following Intralipi d infusion. Parallel to the recovery, urinary net acid excretion increased. NH+4 excretion responded rapidly, titratable acid showed a progressively increasing response and was the major component of net acid excretion. As to the mechanism involved in the activation of NH+4 production in the kidney, it is suggested that in addition to acidaemia increased fatty acid oxidation might contrbute to stimulation of renal gluconeogenesis and ammoniagenesis.

Acid-Base Equilibrium↗
PubMed1975

Effects of norepinephrine on cyclic nucleotide levels in the ductus deferens of the rat.

The effect of 1-norepinephrine on cyclic nucleotide levels was studied in rat ductus deferens. Norepinephrine (0.01-0.3 mM) increased cyclic AMP and cyclic GMP levels in a concentration-dependent manner. Cyclic GMP was increased by about two-fold and cyclic AMP by 30%-40% by 0.1 mM norepinephrine after 3 min. Phenylephrine (0.1 mM) increased cyclic GMP levels about twofold without affecting cyclic AMP. Cyclic GMP was maximally increased by norepinephrine or phenylephrine after 3-10 min, but was not significantly changed after 20 sec, when contraction was fully developed. Atropine did not affect the norepinephrine-induced changes in cyclic nucleotide levels; phentolamine blocked the effect of norepinephrine on cyclic GMP, and propanolol blocked that on cyclic AMP. These findings indicate that in the ductus deferens alpha-adrenergic receptors are involved in the effect of catecholamines on cyclic GMP, and beta-adrenergic receptors are involved in the effect on cyclic AMP levels. The presence of Ca-2+ was required for the effect of norepinephrine on cyclic GMP, but not on cyclic AMP.

Acetylcholine↗
PubMed1975

Hyperaminoacidemia due to the accumulation of gluconeogenic amino acid precursors in hypoglycemic small-for-gestational age infants.

The postnatal (3 to 12 hours) plasma amino acid patterns of normal full-term, nonhypoglycemic, and hypoglycemic small-for-gestational age infants were compared. Seventeen amino acid were separated by automatic column chromatography. It was found that hypoglycemia in SGA newborn infants was associated with a marked increase in total serum amino acid concentrations. This hyperaminoacidemia, which was mainly due to the increase in concentrations of alanine, glycine, proline, and valine, apparently reflected a decreased heapatic gluconeogenic capacity. A significant inverse correlation was observed between concentration of blood glucose and the accumulation of gluconeogenic amino acids. The proportionate accumulation of alanine, glycine, proline, and valine suggests a closely interrelated production and release of these amino acids from the peripheral pools. It is concluded that the changes in concentrations of plasma amino acids occurring in hypoglycemic SGA infants can be helpful in understanding the relative contribution of individual amino acids to gluconeogenesis in the human infant.

Alanine↗
PubMed1973

The importance of calcium ions for the regulation of guanosine 3':5'-cyclic monophosphage levels.

Guanosine 3':5'-cyclic monosphosphate (cyclic GMP) levels in the ductus deferens of the rat were increased 2- to 3-fold by acetylcholine (10-1000 muM) or by 125 mM KCl, while adenosine 3':5'-cyclic monophosphate (cyclic AMP) levels were not changed. After incubation for 30 min in the absence of Ca(++), cyclic GMP control levels were decreased by 85% and were not affected by acetylcholine or KCl. The readdition of Ca(++) (1.8 mM) for 3 min to Ca(++)-deprived tissue partially restored basal cyclic GMP levels and the effects of acetylcholine and KCl. The addition of Sr(++) (3.6 mM) or of Ba(++) (1.8 or 10 mM) also caused an increase in basal cyclic GMP in Ca(++)-deprived tissue. Cyclic AMP levels were not significantly changed under any of these conditions. The addition of the phosphodiesterase inhibitor, 1-methyl-3-isobutylxanthine (0.1 mM), to ductus deferentes increased the amount of cyclic AMP about 50% and that of cyclic GMP about 2-fold. The later effect also depended on the presence of Ca(++). 1-Methyl-3-isobutylxanthine (0.1 mM) increased cyclic GMP and cyclic AMP levels in slices of rat submaxillary glands. Methacholine increased cyclic GMP if added in the presence of methyl isobutylxanthine. Cyclic GMP control levels and the effect of methyl isobutylxanthine were unchanged by Ca(++) omission, but the effect of methacholine was abolished.These findings indicate that calcium ions are important for the control of cyclic GMP levels in these tissues.

Acetylcholine↗