[Hyperlipoproteinemia in mentally retarded children]. / Hyperlipoproteinémie u mentálne retardovaných detí.

Screening revealed a significantly higher incidence of hyperlipoproteinaemia in mentally retarded children in an Institute for Social Welfare than in the healthy child population (P 1%). In the aetiology participate most markedly secondary influences ensuing in particular from complications of the basic diagnosis of oligophrenia. It is mainly a question of the action of antiepileptics, neuroleptics, the influence of viral hepatic infections and other endogenous and exogenous factors. Early diagnosis of hyperlipoproteinaemia is possible so far only by biochemical methods. It is essential for genetic counselling, for prevention of deterioration as regards mental retardation, restriction of pharmacotherapy and later for a reduced risk of development of cardiovascular disease.

High-performance liquid chromatographic determination of cholesteryl esters in the blood of obese children.

The serum of obese children and adolescents was analyzed for cholesteryl esters. The test substances were first separated from the sample matrix by solvent extraction and thin-layer chromatography and then resolved in a reversed-phase high-performance liquid chromatographic system involving a Separon SGX C18 column and a mobile phase of 2-propanol-acetonitrile (40:60, v/v), with ultraviolet detection at 206 nm. Cholesterol and 10-cholesteryl esters could be separated and determined within ca. 25 min at a flow-rate of 1 ml/min. The method was applied to a study of the effect of external conditions (physical stress, diet) on the content of cholesteryl esters in a test group of obese boys and girls aged from 13 to 16 years. The analyses have demonstrated that the above conditions do not affect the concentrations of the individual cholesteryl esters, although the total cholesterol concentration decreased significantly after spa treatment.

[Metabolites of neurotransmitters in the cerebrospinal fluid in children]. / Metabolity neurotransmiteru v mozkomísním moku u detí.

Metabolites of neurotransmitters, homovanillic acid (HVA) and 5-hydroxyindolacetic acid (5-HIAA) were assessed in the cerebrospinal fluid of 149 children of different age from neonatal age to 13 years by the method of high pressure liquid chromatography with electrochemical detection. The mean concentration of the two metabolites in cerebrospinal fluid correlated indirectly with the childrens age--the highest mean concentrations of HVA and 5-HIAA were found in the group of neonates, lower values in infants and the lowest ones in the group of toddlers and older children. In the group of toddlers and older children with severe mental disorders and repeated tonic-clonic or myoclonic seizures a lower mean 5-HIAA was found in the cerebrospinal fluid than in children of equal age, similarly mentally affected but without seizures in the case-history.

[The effect of amino acids on neurotransmitter metabolites in the cerebrospinal fluid]. / Vliv aminokyselin na metabolity neurotransmiteru v likvoru.

Metabolites of neurotransmitters of dopamine, homomovanillic acid (HVA), and of serotonin, 5-hydroxyindole acetic acid (5-HIAA), were assessed in cerebrospinal fluid by the method of high pressure liquid chromatography with electrochemical detection. The HVA concentration in cerebrospinal fluid rose markedly in a two-month-old infant with intracranial hypertension caused by a communicating hyporesorptive hydrocephalus following administration of tyrosine, the precursor of dopamine. The 5-HIAA concentration in cerebrospinal fluid rose significantly in a 20-month-old boy with epilepsy and arrested psychomotor development after administration of 5-hydroxytryptophan, the precursor of dopamine. Biochemical normalization of concentrations of neurotransmiteed metabolites did not lead to changes in the clinical condition of the children.

The value of umbilical blood 2,3 diphosphoglycerate levels in the diagnosis of chronic fetal hypoxia.

The authors assessed the levels of lactate and 2,3 diphosphoglycerate in the umbilical blood of 105 full-term neonates. A significant increase was found in the levels of 2,3 diphosphoglycerate in newborns of mothers with a history of imminent chronic intrauterine hypoxia. The lactate levels of these newborns were the same as in children of mothers without a history showing a risk of intrauterine hypoxia. The psychomotor development of newborns with increased levels of 2,3 diphosphoglycerate was significantly more altered than in those with normal levels in their first year of life.

High-performance liquid chromatographic determination of some polar phospholipids in serum.

The experimental conditions have been optimized for high-performance liquid chromatographic determination of phosphatidylethanolamine (PE), phosphatidylcholine (PC) and sphingomyelin (SM) in serum. The phospholipids are separated on a silica gel column, using a mobile phase of acetonitrile-methanol-water (100:10:18, v/v), with ultraviolet photometric detection at 200 nm. The limit of detection was 0.2 micrograms (in 20 microliters) for natural phospholipids and 2.5 micrograms for synthetic phospholipids; the relative standard deviation was ca. 5%. An alternative detection is tensammetry at a mercury electrode, at a potential of -1.8 V, with an a.c. current frequency of 60 Hz and an amplitude of 20 mV. The tensammetric detection has an advantage in its independence of the structure of the phospholipids. In measurements without a column (flow-injection analysis), the tensammetric detection also yields a somewhat lower limit of detection than photometry (0.15 micrograms per 20 microliters), but this value increases more than ten times in chromatographic detection. The precision is poorer and is more susceptible to interferences. The method was applied to the determination of the above substances in the blood of obese children, as a function of physical stress and spa treatment. It was shown that physical exercise causes a decrease in the contents of PE and PC in the patients. On the other hand, the spa treatment has no pronounced effect on the phospholipid content in the blood.

2,3-diphosphoglycerate during exercise.

The effect of physical exercise on erythrocyte 2,3-diphosphoglycerate (2,3-DPG) content was studied in eight trained speed canoeists aged 15-25 years. One-stage-4-min load on a paddling ergometer corresponding to a 1 km race was observed. During the test, the following cardiorespiratory parameters were recorded: V, VO2, VO2/kg, HR, VO2/HR, R. Blood lactate level and haematocrit were also determined. The average resting values of 2,3-DPG and haematocrit were statistically significant increased. After 6 months intense training there was a significant increase in 2,3-DPG, and the other parameters were also increased.