Deficient brain RNA polymerase and altered nucleolar structure persists until day 8 after perinatal asphyxia of the rat.

RNA polymerases (POL) are integral constituents of the protein synthesis machinery, with POL I and POL III coding for ribosomal RNA and POL II coding for protein. POL I is located in the nucleolus and transcribes class I genes, those that code for large ribosomal RNA. It has been reported that the POL system is seriously affected in perinatal asphyxia (PA) immediately after birth.

Brain RNA polymerase and nucleolar structure in perinatal asphyxia of the rat.

Ribosomes are integral constitutens of the protein synthesis machinery. Polymerase I (POL I) is located in the nucleolus and transcribes the large ribosomal genes. POL I activity is decreased in ischemia but nothing is known so far on POL I in perinatal asphyxia.

Increased steady state mRNA levels of DNA-repair genes XRCC1, ERCC2 and ERCC3 in brain of patients with Down syndrome.

Although deficient DNA-repair was proposed for neurodegenerative disorders including Down Syndrome (DS), repair genes for nucleotide excision repair or X-ray repair have not been studied in brain yet. As one of the hypotheses for the pathogenesis of brain damage in DS is oxidative stress and cells of patients with DS are more susceptible to ionizing irradiation, we decided to study ERCC2, ERCC3 and XRCC1, representatives of repair genes known to be involved in the repair of oxidative DNA-damage. mRNA steady state levels of ERCC2, ERCC3, XRCC1, a transcription activator (TAF-DBP) and an elongation factor (EF1A) were determined and normalized versus the housekeeping gene beta-actin in five individual brain regions of nine controls and nine DS patients.

Apoptosis-associated proteins p53 and APO-1/Fas (CD95) in brains of adult patients with Down syndrome.

In Down syndrome (DS), enhanced apoptosis (programmed cell death) may play a role in the pathogenesis of characteristic mental retardation and precocious dementia of Alzheimer-type. Upregulation of p53 and APO-1/Fas (CD95) precedes apoptosis in many cell types, and a potential role for these molecules has already been demonstrated in Alzheimer's disease (AD) and several other neurodegenerative diseases. We measured p53 and APO-1/Fas (CD95) protein in four different regions of cerebral cortex and cerebellum in nine adult DS patients with Alzheimer-like neuropathologic lesions compared to nine controls.

Brain vasopressin levels in Down syndrome and Alzheimer's disease.

Performing gene hunting in Down Syndrome fetal brain we detected an overexpressed sequence highly homologous to the human vasopressin gene. As this neuropeptide may be involved in the pathogenetic mechanism and, moreover, was described to play a role in memory and learning, we decided to study the brain gene product level in Down Syndrome (DS), controls and patients with Alzheimer's disease (AD). Subtractive hybridization was used to study the differential expression between steady state mRNA levels in fetal brain of DS and controls at the 23rd week of gestation.

N-acetylneuraminic acids (nana): a potential key in renal calculogenesis.

N-Acetylneuraminic acids (NANA) promote binding of calcium ions to macromolecules and cells, increase the intrinsic viscosity of glycoproteins and facilitate gel formation in water. Since these properties are crucial in urinary calculogenesis, we evaluated NANA levels in urine and serum as well as their expression in kidney tissues. Using a modified thiobarbituric acid assay, the evaluation of free and bound NANA in 24-h urine samples revealed a ratio of 1.

Juvenile hyaline fibromatosis: impaired collagen metabolism in human skin fibroblasts.

Juvenile hyaline fibromatosis (JHF) is inherited as a fatal autosomal recessive disorder characterised by multiple tumorous mucocutaneous proliferations. In this paper a 14 month old girl with JHF is described. For this condition, a malfunction of collagen synthesis is considered as the pathogenetic cause.

Transcription and activity of antioxidant enzymes after ionizing irradiation in radiation-resistant and radiation-sensitive mice.

The involvement of the antioxidant enzymes superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase in radiobiological processes has been described at the enzyme activity level. We irradiated radiation-resistant (RR) and radiation-sensitive (RS) mice and studied antioxidant enzymes at the transcriptional and activity level. In addition, aromatic hydroxylation and lipid peroxidation parameters were determined to study radiation resistance at the oxidation level.

Decrease of brain protein kinase C, protein kinase A, and cyclin-dependent kinase correlating with pH precedes neuronal death in neonatal asphyxia.

Background: Acidosis, energy depletion, overstimulation by excitatory amino acids, and free radical-mediated reactions are the major, current concepts for the explanation of damage and death resulting from asphyxia. Impaired protein phosphorylation by protein kinase C represents another mechanism incriminated in cell death.

Methods: We used a nonsophisticated perinatal asphyxia model to study brain (frontal cortex) pH, ATP, protein kinases PKC, PKA, and cyclin-dependent kinase.

[The Austrian Metabolic Register].

The "Austrian Register for Metabolic Disorders" was founded in 1995 on the initiative of the "Work Group for Congenital Metabolic Disorders" within the Austrian Society for Pediatrics. It is designed as a clearinghouse for reporting and recording congenital metabolic disorders and aims to determine the frequency and regional distribution of these diseases. Another objective is to have patient data handy if and when new therapeutic options or new means of diagnostic verification, including carrier status or prenatal diagnosis, become available.

Fucosidosis: genetic and biochemical analysis of eight cases.

The molecular basis of the deficiency of alpha-L-fucosidase has been investigated in eight patients who had been diagnosed clinically and enzymatically as suffering from the autosomal recessive lysosomal storage disease fucosidosis. None of the patients had a deletion or gross alteration of the alpha-L-fucosidase gene (FUCA1). Single strand conformation polymorphism (SSCP) analysis followed by direct sequencing of amplified exons and flanking regions identified putative disease causing mutations in six of the patients, who had severe forms of the disease and very low residual alpha-L-fucosidase activity and protein.

The effects of acid glycosaminoglycans on neonatal calvarian cultures--a role of keratan sulfate in Morquio syndrome?

Morquio syndrome (mucopolysaccharidosis IV) presents with multiple bone dysplasia and is characterized by the inability to degrade keratan sulfate due to deficient N-acetylgalactosamine-6-sulfate sulfatase in Morquio A syndrome and deficient beta-D-galactosidase in Morquio B syndrome. The aim of our study was to investigate into the pathogenetic mechanism as it is not clear whether the accumulation of keratan sulfate is toxic for osteoblasts or inhibits osteoblast activity as e.g.

Comparison of sialic acids excretion in spot urines and 24-hour-urines of children and adults.

Sialic acids comprise all N- and O-acyl derivatives of neuraminic acid and are components of glycoproteins and glycolipids. Their concentrations vary physiologically with age but also in diseases such as inflammation, neoplastic tumours or in inborn genetic disorders causing abnormal sialic acid metabolism. Determination of free and bound sialic acids in urine using the thiobarbituric acid method according to Warren (J Biol Chem 1959; 234:1971-5) was shown to be useful for the diagnosis of diseases that involve sialic acid metabolic disorders.

Homocysteine increases cyclin-dependent kinase in aortic rat tissue.

Background: Hyperhomocyst(e)inemia is strongly associated with occlusive arterial disease. A direct effect of homocysteine on the proliferation of smooth muscle cells was proposed recently. This observation led us to examine the effect of homocysteine on cyclin-dependent kinase, the starter of mitosis and reflecting proliferation.

Evidence for McKusick's hypothesis of deficient collagen cross-linking in patients with homocystinuria.

Osteoporosis occurs commonly in homocystinuria. The underlying pathobiochemical mechanism remains unclear; disturbed cross-linking of collagen has been suggested but this hypothesis has not been fully tested, nor have studies on collagen synthesis been performed. We therefore used recently available noninvasive tests for collagen synthesis and cross-linking to examine 10 patients with homocystinuria.

[Mucopolysaccharidoses from the view point of mucopolysaccharidoses families--10 years' experiences of the "Austrian Society for Mucopolysaccharidoses"].

The mucopolysaccharidoses (MPS) are rare inborn errors of metabolism. They are caused by defects in enzymes which are necessary for the degradation of mucopolysaccharides. An effective causal treatment is not available as yet.

Skin collagen defects in a patient with juvenile hyaline fibromatosis.

Juvenile hyaline fibromatosis is a rare disorder characterised by multiple subcutaneous tumours, gum hypertrophy, muscle weakness, and flexion contractures of the large joints. Histology shows an abundance of a homogenous, amorphous, acidophilic extracellular matrix in which spindle shaped cells are embedded forming minute streaks. It has been previously suggested that collagen abnormalities may be involved.

Histology and electron microscopy of fucosidosis of the skin. Subtle clues to diagnosis by electron microscopy.

Fucosidosis is an autosomal recessive inborn error of metabolism in which fucose-containing glycolipids, glycoproteins, and oligo- and polysaccharides accumulate in tissues as a consequence of alpha-L-fucosidase deficiency. Since the detection of this entity in 1966 several cases have been described, but until now investigations of clinically uninvolved skin have not been performed. In this study we have investigated clinically normal skin obtained from a patient with fucosidosis and his healthy sister, by light and electron microscopy, to determine whether normal skin in this condition yields clues that may have prognostic relevance.

[Mucopolysaccharidoses--current aspects of diagnosis and therapy].

The mucopolysaccharidoses, first described at the beginning of this century, are still subject of research. The accumulation of pathological metabolites and the underlying enzyme defects are now correlated to specific gene mutations. A comparison of genotype and phenotype of the individual forms of the mucopolysaccharidoses is the subject of ongoing studies.

Creatine reduces collagen accumulation in the kidneys of diabetic db/db mice.

In the present study, we tested the hypothesis whether creatine, a metabolite of arginine metabolism, shares the pharmacological activities of arginine reducing collagen accumulation in the diabetic kidney. Ten db/db mice were given, for 3 months, a solution containing a daily dosage of creatine of 50 mg/kg body weight. Eleven db/db mice served as controls.

Plasma sialic acid in patients with prostate cancer.

Serum sialic acid (N-acetylneuraminic acid) was evaluated as a tumour marker for prostate cancer and compared with serum prostate specific antigen (PSA). The records of 35 patients suffering from prostate cancer (9 with bone metastases) were analysed and compared with those of 21 healthy individuals. Total serum sialic acid was significantly elevated among the cancer patients.