[Levels of L-carnitine in the Venezuelan infant population]

The L-carnitine blood serum and amniotic fluid levels were measured in 133 samples obtained from clinically healthy patients: 39 pregnant women with a fetal gestational age ranging from 14 to 40 weeks, 13 newborn children less than a day old, 19 newborn children between the ages of 1 and 30 days, 8 breast-feed babies and 19 children over two years of age. No significant statistical differences were seen in the maternal blood serum and amniotic fluid samples for the different gestational ages considered in the study. The average values were found to be 22.6 +/- 5.1 nmol/mL for maternal blood serum and 25.3 +/- 9.4 nmol/mL for amniotic fluid. The blood serum levels were found to be greater in the group between the ages of 1 to 30 days, reaching levels of 43.1 +/- 7.4 nmol/mL. In the group aged 1 month-18 years, the serum levels were on the average 34.3 +/- 6.7 nmol/mL. The variations found among these groups reflect characteristics specific of our population. These values should be further researched since they differ from those values reported by the Anglo-Saxons. L-carnitine concentration; blood serum level; amniotic fluid level.

Surfactant therapy and spontaneous diuresis

The effect of artificial surfactant therapy on renal function and the onset of spontaneous diuresis was prospectively evaluated in 19 infants with hyaline membrane disease in a double-blind, controlled study. Twelve infants were in the surfactant group; seven infants received placebo (0.9% saline solution). There was no difference in the time of onset of spontaneous diuresis (as defined by output greater than or equal to 80% of intake). The glomerular filtration rate, determined by endogenous creatinine clearance, was also similar in the surfactant- and placebo-treated infants during the first 3 days of life. The fractional excretion of sodium was significantly higher in the placebo group at 24 hours and 36 hours. Infants in the placebo group had a higher negative sodium balance than those in the surfactant group. Ventilatory status improved significantly soon after surfactant treatment, as evidenced by improvement in the alveolar/arterial oxygen pressure ratio and by a lower mean airway pressure. These data suggest that ventilatory status can be improved without diuresis; the factors that regulate diuresis are multiple and not fully understood.

Prospective study of diarrhoeal disease in a cohort of rural Mexican children: incidence and isolated pathogens during the first two years of life

Colonization of the intestine by putative pathogens was followed longitudinally in a cohort of 56 infants born during one calendar year in a rural Mexican village with faecal cultures taken every fortnight and every time a child had diarrhoea. The frequency of isolation of pathogens during episodes of diarrhoea was compared with that of matched controls from the same cohort. Incidence of diarrhoea during the first year of life was 98%, diminishing to 93% during the second year. The incidence curves for each year were not significantly different (P greater than 0.1). Isolation of enteropathogenic Escherichia coli, enterotoxigenic Escherichia coli producing heat-stable (ST) and/or heat-labile (LT) enterotoxins and rotaviruses was significantly higher in infants with diarrhoea during the first 2 years of life. In the case of shigella, although no significant differences were found by semester of life, 13 of 16 children in which these strains were found had diarrhoea. Isolation of Salmonella spp., Campylobacter spp. and protozoa were not significantly different in the two groups during the period studied. Strains showing localized adherence to HEp-2 cells or the presence of colonization factor antigens I or E8775 were found with significantly higher frequency in children with diarrhoea. Eighty-two percent of ST+ or LT+ ETEC strains isolated produced one of the three known colonization factors.

Plasma glucose, insulin, proinsulin, C-peptide and glucagon before and after a carbohydrate-rich meal in hyperthyroid patients

The function of the pancreatic B- and A- cell during a carbohydrate-rich meal was investigated in hyperthyroid patients, since these patients frequently present an altered handling of glucose. In basal conditions the plasma levels of glucose, immunoreactive insulin (IRI), C-peptide (CPR), proinsulin were higher in hyperthyroid patients than in normal subjects, whereas plasma glucagon was similar in the two groups. Hyperthyroid patients had high post-breakfast incremental areas of glucose and IRI and those of CPR and glucagon were normal. In post-breakfast plasma, the hyperthyroid patients had high proinsulin and normal insulin levels. The molar ratio between CPR and IRI was low throughout the test in the hyperthyroid group. In conclusion, in the hyperthyroid group the plasma levels of proinsulin were high and those of glucagon were normal; in response to the standard breakfast the levels of insulin and C-peptide were normal. These findings do not explain the altered glucose handling present in these patients.

Pulmonary hypertension in the fetus, the newborn, and the child

Pulmonary hypertension is a syndrome characterized by high pulmonary vascular resistance. It is a well described entity in newborn infants and children but almost unknown in the fetus. Therefore, this article focuses mainly on the former and then summarize how we diagnose and manage the problem in the fetus.

[Effect of sodium and potassium on cardiac infarct in rats]

During the induction of myocardial infarction in the rat by isoproterenol, a decrease in the voltage of the T wave in the electrocardiogram is produced, which reflects myocardial ischemia through a previous infusion of a KCl solution; while the perfusion of NaCl increases the voltage of such wave and therefore cardiac ischemia. The values of free Pi in the myocardium increase significantly with the administration of isoproterenol. If KCl has been perfused previously, the figures of free Pi are superior in 155% of those obtained with the perfusion of NaCl. The values of all the energetic phosphates, AMP, ADP and ATP decrease inversely and in a significant way with isoproterenol and the perfusion of NaCl and KCl. The activity of creatine-phosphokinase in the myocardium decreases with isoproterenol, specially with the previous perfusion of KCl Similarly, the activity of the isoenzimes of lactic dehydrogenase L1 and L2 (alpha-HBDH), decreases, which intensifies with previous perfusion of NaCl, but diminishes with KCl. The activity of malicodehydrogenase (MDH) in the myocardium decreases with isoproterenol, even with the previous perfusion of NaCl, but in lesser degree than with KCl.