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Biomedical subjects

J Zeman

Publications and source records attributed to J Zeman.

At least 91 records · Page 5Linked to original sources
PubMed1995

Altered properties of mitochondrial ATP-synthase in patients with a T-->G mutation in the ATPase 6 (subunit a) gene at position 8993 of mtDNA.

A family is described with a T-->G mutation at position 8993 of mtDNA. This mutation is located in the ATPase 6 gene of mtDNA which encodes subunit a of the ATP-synthase complex (FlFo-ATPase). Clinically, the patients showed severe infantile lactate acidosis and encephalomyopathy in a form that was different from the classical Leigh syndrome. In 3 affected boys, ranging in age from 3 months to 8 years, the mutation was found in 95-99% of the mtDNA population. The clinical symptoms correlated with the mtDNA heteroplasmy and in the healthy mother 50% of the mtDNA was mutated. The rate of mitochondrial ATP production by cultured skin fibroblasts containing 99% of mutated mtDNA was about 2-fold lower than that in normal fibroblasts. Native electrophoresis of the mitochondrial enzyme complexes revealed instability of the FlFo-ATPase in all the tissues of the patient that were investigated (heart, muscle, kidney, liver). Only a small portion of the ATP-synthase complex was present in the complete, intact form (620 kDa). Incomplete forms of the enzyme were present as subcomplexes with approx. molecular weights of 460, 390 and 150 kDa, respectively, which differed in the content of F1 and Fo subunits. Immunochemical analysis of the subunits of the FlFo-ATPase further revealed a markedly decreased content of the Fo subunit b in mitochondria from muscle and heart, and an increased content of the Fo subunit c in muscle mitochondria, respectively. These results indicate that in this family the T-->G point mutation at position 8993 in the mitochondrial ATPase 6 gene is accompanied by structural instability and altered assembly of the enzyme complex, that are both most likely due to changes in the properties of subunit a of the membrane sector part of the ATP-synthase.

Acidosis, Lactic↗
PubMed1995

Monoamine neurotransmitters and metabolites in the cerebrospinal fluid following perinatal asphyxia.

While the release of neurotransmitters is involved in the pathophysiology of brain damage following birth asphyxia, it also plays a role in endogenous defense against such damage. Levels of monoamines and the main cerebral monoamine metabolites in the cerebrospinal fluid (CSF) were measured in asphyxiated and control infants within 24 h after birth. The results indicate an increased turnover of noradrenaline (NA) and dopamine following asphyxia. Furthermore, the NA stores in the brain seem to be exhausted in some cases. We conclude that this increase in catecholamine turnover to some extent explains the clinical symptoms of hypoxic-ischemic encephalopathy and that it may reflect an intrinsic adaptive capacity to perinatal distress.

Asphyxia Neonatorum↗
PubMed1994

Hb Nottingham or alpha 2 beta 2 98 (FG5) Val-->Gly in a Czech child.

We report a fourth case of Hb Nottingham [alpha 2 beta 2 98 (FG5) Val-->Gly] observed in an 8-year-old girl in the Czech Republic with clinical and laboratory symptoms of severe hemolytic anemia. The unstable hemoglobin probably represents a de novo mutation, since the parents of the patient and the two siblings do not exhibit any hematological abnormalities. Splenectomy had a beneficial effect on the degree of hemolysis, as well as on the Hb level.

Amino Acid Sequence↗
PubMed1994

Hajdu-Cheney syndrome in a 3 1/2 year old girl.

Hajdu-Cheney acro-osteolysis is reported in a 3 1/2 year old girl whose mother has the syndrome. Acro-osteolysis was shown to be absent at the age of 2 1/2 years. It was demonstrated on hand X-rays performed a year later. This is the youngest case of Hajdu-Cheney acro-osteolysis reported in the literature.

Child, Preschool↗
PubMed1994

[Discrimination value of tests performed with the STAPHYtest Lachema from the aspect of clinical microbiology].

The authors characterize individual tests of the STAPHYtest Lachema and some other selected tests by calculating their discriminating capacity on 16 types of staphylococci which are most frequently isolated in clinical microbiological laboratories. Individual tests are characterized by the separating value, as described by Gyllenberg and Rypka, the variation index of Sneath and the consistency index. As regards discrimination, tests involving fermentation of trehalose, sucrose and glycerol are of no value. Conversely more important tests are lacking--sorbitol, melisitose, ONPG, DNA-ase, arginine.

Bacteriological Techniques↗
PubMed1993

Deficiency of pyruvate dehydrogenase complex in tissues of an eight month old infant.

A metabolic investigation was carried out in an eight-month old infant with intrauterine hypotrophia, failure to thrive, psychomotoric retardation and cerebral atrophy, who died after respiratory infections. Blood analysis revealed intermittent lactic acidosis with normal lactate/pyruvate ratio. Activities of cytochrome c oxidase in skeletal muscle, heart, liver and fibroblasts were all in the reference range of controls. Activity of pyruvate dehydrogenase complex (PDH) was decreased in muscle homogenate, heart and liver mitochondria but was normal in cultured skin fibroblasts. Immunodetection of PDH subunits, and assay of El alpha phosphorylation showed in the patient decrease of E1 alpha in skeletal muscle, and enhanced level of E1 alpha phosphorylation in liver mitochondria.

Cells, Cultured↗
PubMed1993

[Metabolic study in a child with Leigh's syndrome and deficient activity in complex I of the respiratory chain].

Leigh's syndrome--subacute necrotizing encephalomyopathy--is a serious disease of child age manifested by severe psychomotor retardation, a varied neurological symptomatology, a typically symmetrical neuropathological affection of the central nervous system in the area of the basal ganglia and a metabolic disorder affecting the energy system of cells. The authors describe the clinical course of the disease and the results of metabolic and neuropathological investigations in an infant with Leigh's syndrome and severe lactate acidosis based on deficiency of complex I activity of the respiratory chain.

Female↗
PubMed1991

Accumulation and impaired in vivo metabolism of di- and trihydroxycholestanoic acid in two patients.

Two patients with a suspected peroxisomal disorder on the basis of neurological, craniofacial, hepatological and other abnormalities were studied. The phenotype of both girls was remarkably similar from birth until age 1.5 yr. Detailed studies in plasma revealed normal plasma very-long-chain fatty acids but the presence of di- and trihydroxycholestanoic acids and the C29-dicarboxylic bile acid, all known to occur in plasma from Zellweger patients. These results suggest an isolated defect in the peroxisomal beta-oxidation of the side chains of the cholestanoic acids. Activation of trihydroxycholestanoic acid and beta-oxidation of trihydroxycholestanoyl-CoA, measured in a liver biopsy, were normal, however, as was the peroxisomal beta-oxidation of palmitate. Although the molecular defect remains unknown, the results stress the importance of performing multiple analyses in any patient suspected to suffer from a peroxisomal disorder and indicate that screening for peroxisomal disorders based upon analysis of only plasma very long chain fatty acids with or without analysis of erythrocyte plasmalogen levels, may be inadequate.

Abnormalities, Multiple↗
PubMed1991

[The effect of amino acids on neurotransmitter metabolites in the cerebrospinal fluid].

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.

Child, Preschool↗
PubMed1991

When is it possible to meet the wish of a woman to terminate her labour by caesarean section?

The authors have evaluated 311 answers of Czech obstetricians to the questionnaire concerning their attitude towards pregnant women that want to terminate their labour by caesarean section. The questionnaire contained six model situations: (1) normal delivery; (2) previous caesarean section; (3) breech presentation; (4) previous delivery of an injured baby; (5) protracted labour and (6) caesarean section apparently indicated by another obstetrician. In each situation the obstetrician was encouraged to choose from five different answers. The results have revealed the lack of unanimity in some cases, 3, 4 and 5. Here we feel that the obstetrician should meet the wish of the woman. However, in those situations that are clear from the medical point of view and where there is no professional indication for a caesarean section, it is in accordance with the Czechoslovak rule of law not possible to meet the wish of the woman.

Cesarean Section↗
PubMed1991

Mevalonic aciduria.

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Child, Preschool↗