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Biomedical subjects

W Sperl

Publications and source records attributed to W Sperl.

At least 73 records · Page 4Linked to original sources
PubMed1993

Diagnosis and therapy of organic acidurias.

Organic acidurias are a group of numerous inherited metabolic disorders with an involvement of different pathways of the amino acid, carbohydrate and lipid metabolism. Many diseases have their onset with an acute metabolic crisis in the newborn period. The most important diagnostic investigation is organic acid analysis of urine by gas chromatography-mass spectrometry. Because specific clinical signs are lacking, a selective screening procedure is recommended. Diagnosis and therapy should be aggressive, since prognosis of many disorders is related to early diagnosis and specific therapeutic measures. These include long term management with protein restriction, supplementation with special amino acid mixtures and carnitine. In our experience continuous arteriovenous hemofiltration has turned out to be a very effective detoxification method during acute metabolic crisis of the newborn. Long term follow up and therapy control is very important for the outcome of the patients. Measurement of odd long chain fatty acids (OLCFA) in erythrocyte membranes has proved to be a good control parameter of the metabolic condition of children with disorders of the branched-chain amino acid metabolism.

Amino Acid Metabolism, Inborn Errors↗
PubMed1992

Storage material from urine and tissues in the nephropathic phenotype of infantile sialic acid storage disease.

We analysed urine and tissue specimens from two nephrotic infantile sialic acid storage disease patients (nISSD) for free and bound sialic acids in comparison to non-nephrotic ISSD patients (ISSD), patients with minimal change nephrosis (nControl) and normal controls (Control). No differences in the excretion of urinary free sialic acid could be detected between ISSD and nISSD urines. Sialyloligosaccharide fractions were only slightly elevated and of apparently normal composition. Owing to glomerular dysfunction, measurable quantities of protein-bound sialic acids were present in nISSD and nControl. In nISSD tissues, free sialic acid was elevated 18-100-fold above control and 3-12-fold above Niemann-Pick A (NPA) samples. The storage of membrane-bound sialic acid was slightly increased compared to control tissues, but equal to those from NPA, thus reflecting an unspecific increase of membranes due to lysosomal storage. According to these results no major biochemical differences were detectable between ISSD and nISSD. The nephrotic syndrome in nISSD could not be related to a general deficit in the sialylation of glycoproteins. Nevertheless, a cell membrane-specific alteration in sialoglycoproteins of glomerular cells might still be possible.

Glycosaminoglycans↗
PubMed1992

Combined deficiencies of the pyruvate dehydrogenase complex and enzymes of the respiratory chain in mitochondrial myopathies.

In six patients with mitochondrial (encephalo-) myopathy investigations of skeletal muscle revealed a defect of pyruvate dehydrogenase complex (PDHC) in combination with one or more respiratory chain complex deficiencies. A combination of defects of this kind has not been reported previously. Five of the six patients presented within the 1st year of life and had a severe clinical course. Intrafamilial variability of the clinical course in dizygotic twins both suffering from a cytochrome c oxidase deficiency and one of them also from a PDHC deficiency suggests an additional effect of PDHC deficiency on the clinical symptoms. Immunoblot studies of PDHC in five of the patients revealed no abnormalities in their subunit pattern, rendering a defect of mitochondrial protein import or assembly unlikely. The finding of a combined PDHC and respiratory chain deficiency has implications for the diagnostic approach, for therapy and genetic counselling. The exact pathogenetic mechanism of this combination of defects remains to be elucidated.

Female↗
PubMed1992

Myopathology and a mitochondrial DNA deletion in the Pearson marrow and pancreas syndrome.

A patient with the Pearson marrow and pancreas syndrome is presented. She showed an anaemia with neutropenia and thrombopenia, failure to thrive, diarrhoea, disturbed glucose homeostasis and lactic acidosis. An exocrine pancreatic insufficiency was lacking. The disease followed a fatal course. Biochemical investigations of skeletal muscle revealed a disturbed mitochondrial energy metabolism, while many ultrastructural abnormal features were observed in the muscle tissue. Molecular genetic studies showed a de novo deletion in the mitochondrial DNA (mtDNA), different in size from the already published deletions and flanked by two 4 bp direct repeats, interspaced by 4-5 non-repeated nucleotides. mtDNA from 12 other tissues showed the same deletion in different percentages. No obvious relation between these percentages and tissue dysfunction was found. In spite of an open reading frame of 74 codons, only little transcription product of the genomic region resulting from the deletion was found.

B-Lymphocytes↗
PubMed1992

Postnatal development of pyruvate oxidation in quadriceps muscle of the rat.

In order to evaluate the age dependency of enzymes involved in the energy-generating system, skeletal muscle specimens from rats of different ages were investigated for several mitochondrial enzymes. [1-14C]pyruvate (+/- ADP) oxidation rates and pyruvate dehydrogenase complex (PDHC) activity increased significantly from low early values during the neonatal period to nearly adult values at the end of the suckling period. Other enzymes of the pyruvate oxidation route such as citrate synthase and cytochrome c oxidase showed similar patterns of development. Immunoblot studies of PDHC detected a clear increase in the intensity of the bands of the alpha subunits of E1 (pyruvate dehydrogenase) and E2 (dihydrolipoyl transacetylase) within the first 3 weeks of life. The ratio between the individual PDHC proteins indicated that E1 alpha, the regulatory subunit of the multienzyme complex, is the most rapidly increasing protein with age.

Acetyltransferases↗
PubMed1992

Maturation of mitochondrial and other isoenzymes of creatine kinase in skeletal muscle of preterm born infants.

We studied pre- and postnatal changes in total creatine kinase (CK) activity, mitochondrial creatine kinase (Mi-CK) activity and immunochemical reactivity with anti-Mi-CK antibodies in skeletal muscle specimens from 12 infants, 10 of them preterm born, after a pregnancy varying between 28 and 40 weeks. Our results demonstrate that Mi-CK is present in fetal human quadriceps muscle and that the specific activity of Mi-CK increases during prenatal development from week 28 to 40 by a factor about two. Generally, adult levels have not been reached at birth, indicating a further postnatal increase of the activity of the enzyme. The Mi-CK protein content also increases during prenatal development. These results suggest that in human skeletal muscle the expression and accumulation of Mi-CK starts at mid-gestation, later than is known to occur for cytosolic CK.

Citrate (si)-Synthase↗
PubMed1992

Enzyme activities of the mitochondrial energy generating system in skeletal muscle tissue of preterm and fullterm neonates.

Quadriceps muscle specimens from autopsy of 28 neonates (gestational age 25-42 weeks) were investigated to determine pyruvate and malate oxidation rates and several enzymes of the mitochondrial oxidative process. In general, the levels of all mitochondrial parameters measured, including carnitine levels, were lower in the neonates who died within the first week of life than those in the control group (age > 5 years). Pyruvate and malate oxidation rates (P < 0.05), activities of pyruvate dehydrogenase complex (P < 0.10) and succinate: cytochrome c oxidoreductase (P < 0.05) increased significantly with gestational age. Pyruvate oxidation rates (P < 0.05) as well as activities of citrate synthase (P < 0.05) and NADH:Q1 oxidoreductase (P < 0.05) were significantly lower in the group of very preterm infants at an age of 1-7 days compared with very preterm infants at an age between 3-8 weeks. We conclude from our study that special reference values are necessary for a correct biochemical diagnosis of mitochondrial encephalomyopathies in the neonatal period. Differences between preterm and fullterm children of the same age (1 week) indicate a maturational process in human muscle tissue during gestation. Comparison of two different age groups within the very preterm neonates point to a postnatal maturation of the mitochondrial energy metabolism, at least in preterm neonates.

Carnitine↗
PubMed1992

Atypical (mild) forms of dihydropteridine reductase deficiency: neurochemical evaluation and mutation detection.

We investigated two patients with an atypical (mild) form of dihydropteridine reductase (DHPR) deficiency. Both responded to the loading test with tetrahydrobiopterin; their plasma phenylalanine levels were lowered from 278 mumol/L to 85 and 48 mumol/L and from 460 mumol/L to 97 and 36 mumol/L after 4 and 8 h, respectively. In one of the patients, a combined loading test with phenylalanine followed by tetrahydrobiopterin was also carried out and showed a profile typical for DHPR deficiency. The phenylalanine hydroxylation rate was calculated to be 43 and 87%, 4 and 8 h after cofactor administration, respectively. Diagnosis was confirmed by the absence of DHPR activity in the patient's erythrocytes. In cultured fibroblasts, residual activity of 4 and 10%, respectively, was found. Excretion of urinary pterins was essentially normal, and the biopterin to neopterin ratio in cerebrospinal fluid was increased. Although in both patients cerebrospinal fluid homovanillic acid was found to be normal, and 5-hydroxyindoleacetic acid was substantially reduced, there was no sign of neurologic alterations until the age of 2 y. However, one of the patients recently developed deceleration of head growth, whereas psychomotor development continued to be normal for age. Using the chemical cleavage method on the amplified cDNA, mismatches of T to G at nucleotide 659 and of G to A at nucleotide 475, respectively, were identified. These results also demonstrate that screening for tetrahydrobiopterin deficiency by urinary pterin analysis alone can miss some newborns with mild DHPR deficiency and that all children with tetrahydrobiopterin defects need full neurochemical evaluation together with analysis of the enzyme activity.

Amino Acid Metabolism, Inborn Errors↗
PubMed1992

[Clinical suspicion of inborn errors of metabolism].

A number of inherited metabolic disorders are diagnosed by means of the nationwide newborn screening programme, usually before the first clinical signs occur. As for the rest of the varied metabolic disorders, knowledge and intuition of the paediatrician is a prerequisite for selection of patients for further metabolic investigation (selective screening procedure). Clinical symptoms of the most important metabolic diseases can be classified according to their pathophysiological background as: "intoxication type, energy deficiency type, storage type, neurodegenerative type". Especially in the first year of life, clinical features are unspecific: psychomotoric retardation, muscular hypotonia, cerebral convulsions, recurrent vomiting, sepsis-like conditions. In these cases indication for metabolic screening is broad. Especially in older children some clinical symptoms can be specific for a metabolic disorder: distinctive odour of urine, changes in hair, skin or eyes, organomegaly, skeletal changes. Recently, Reye-like syndrome, stridor, macrocephaly and vague, cerebral ischaemic episodes have been described in association with a metabolic defect. In conclusion, experience has shown that only a small number of metabolic disorders will be diagnosed from the typical clinical picture alone. In most cases a selective screening procedure leads to diagnosis because initial symptoms are unspecific.

Diagnosis, Differential↗
PubMed1991

[Chilaiditi's colon interposition in a patient with Rett syndrome].

We report on a patient with Rett syndrome associated with Chilaiditis interposition of the colon. Episodes of severe hyperventilation with aerophagia, immobility and obstipation facilitated the occurrence of an interposition of the colon. Conservative therapeutic measures were not successful, surgical intervention was necessary to cure the symptoms.

Child↗
PubMed1991

[Diagnosis and therapy of acute metabolic crisis in the neonatal period].

Important for the clinical outcome of an acute metabolic crisis in the newborn infant are early diagnosis and specific therapeutic measures. A selective screening procedure for the diagnosis of disorders in amino and organic acid metabolism, for beta-oxidation and urea cycle defects and mitochondriopathies is necessary. Gas chromatography/mass spectrometry is the leading diagnostic tool in this screening procedure. During the last six years ten patients with an acute metabolic crisis in the newborn period were observed at the Children's Hospital at the University of Innsbruck. In seven of them the onset of the disease occurred within the first week of life. Initially the most important therapeutic measures were withdrawal of food, induction of anabolism and specific detoxification. In our experience continuous arteriovenous hemofiltration has proved to be an efficient and applicable method for elimination of toxic metabolites in the acute crisis of a newborn infant.

Diagnosis, Differential↗
PubMed1991

[Effects of health and medical undertreatment on the clinical status and social behavior of infants and small children in a Romanian orphanage].

The homage of 135 abandoned children in the city of Resita, south west Rumania, has been checked by a medical team from the University of Innsbruck for social, clinical and hyginical situation. The local government had applied for such an investigation. Most of the infections and other diseases are based on a dramatically bad hygienical situation. 52% of checked sera were HIV positiv by RIA and Western Blot, moreover 60% Hepatitis B antigen positiv. We assume a high rate of horizontal transmission of the HIV virus. One of the main clinical symptoms was maternal-deprivation syndrome, with an incidence of 80%. Consequences in personal policy of the homage as well as medical strategies have to follow.

Child Health Services↗