Search PubMed⌕ Search

Biomedical subjects

C Jakobs

Publications and source records attributed to C Jakobs.

At least 289 records · Page 16Linked to original sources
PubMed1990

Prenatal diagnosis of inherited metabolic disorders by quantitation of characteristic metabolites in amniotic fluid: facts and future.

An attempt is made to summarize as completely as possible what is known about the prenatal diagnosis of amino- and organic acidurias by direct measurement of characteristic metabolites in amniotic fluid, and to indicate which disorders can potentially be diagnosed prenatally by direct quantitation of metabolites. Furthermore, the disorders are mentioned in which the prenatal diagnosis was proven to be unsuccessful by this approach. The prenatal diagnoses of a case of propionic acidemia and a case of tyrosinemia type I in the 11th and 12th week of gestational age, respectively, are reported and the prospects of performing amniocentesis in the first trimester for prenatal diagnosis are discussed.

Amniocentesis↗
PubMed1990

Plasma polyol levels in patients with cataract.

Galactitol and sorbitol concentrations in plasma were determined in patients (with or without cataract) in whom homo- or heterozygosity for galactokinase, galactose-1-phosphate uridyltransferase, systemic or peripheral UDP-galactose epimerase and sorbitol dehydrogenase deficiency was confirmed. For the above disorders it can be concluded that elevation of plasma polyols is not always related to the presence or absence of cataract. In all cases with cataract, however, the plasma galactitol or sorbitol levels were elevated. In another group of patients with unexplained congenital or infantile cataracts, but without apparent enzyme defects, mild to moderately elevated concentrations of plasma galactitol or sorbitol were found in about 45%. In 8% of this group the cataract and the elevated plasma galactitol concentration could possibly have been related to partial maternal enzyme deficiency. In all the other cases the elevated plasma polyol concentration remains unexplained but could indicate a further cause of cataract formation due to a hitherto unknown galactose or glucose metabolic aberration.

Carbohydrate Epimerases↗
PubMed1990

Examination of urine metabolites in the newborn period and during protein loading tests at 6 months of age--Part 1.

In the course of the collaborative study of children treated for PKU, urine samples from a total of 165 patients were analysed at six different times: in the newborn period before onset of therapy, after beginning of dietary management, during and immediately after a protein loading test at 6 months of age. In 95.9% of newborns with elevated Phe levels in plasma, metabolites of this amino acid as well as of Tyr could be detected. Of all metabolites phenylpyruvate always showed the highest concentration, followed by phenyllactate and o-hydroxy-phenylacetate. During the protein loading test an increase of the same metabolites occurred. At the age of 6 months the percentage of p-hydroxylated compounds related to the sum of all metabolites was lower than in the newborn period. Comparing the results of urine analyses at 6 months of age after the protein loading tests with the classification of HPA into the reaction types I-III, it can be clearly stated that patients with the milder forms II and III have already lower levels of Phe metabolites in urine before onset of therapy compared to the reaction type I. In retrospect 52% of the newborns could therefore be classified as reaction type I even before beginning of dietary management. The analysis of urinary Phe metabolites before the onset of therapy therefore provides sufficient information about the reaction type.

Creatinine↗
PubMed1990

A new case of hyperargininaemia: neurological and biochemical findings prior to and during dietary treatment.

We present clinical and biochemical data on a further patient with hyperargininaemia and the results of neurophysiological tests both before and during dietary treatment with an essential amino acid mixture. With normalisation of plasma arginine concentrations, neurological functions improved and brain stem auditory evoked potentials normalized suggesting a partially reversible central conduction disorder. Neuroradiological findings included cerebral cortical atrophy on computed tomography scan and patchy abnormal myelination on magnetic resonance imaging (MRI). The typical clinical picture is discussed with reference to published therapeutical trials.

Amino Acid Metabolism, Inborn Errors↗
PubMed1990

Acute hemiparesis as the presenting sign in a heterozygote for ornithine transcarbamylase deficiency.

Strokes in children occur in conjunction with cardiac disease, hematological disorders, trauma, intracranial infections and migraine. Recently several inborn errors of metabolism have been recognized as possible causes of stroke-like symptoms. We describe a female heterozygote of ornithine transcarbamylase deficiency, who presented with convulsions and right sided hemiplegia. MR-imaging of the brain demonstrated an acute ischemic lesion in the left hemisphere. In addition to other known metabolic causes of stroke like attacks urea cycle defects should be considered in the differential diagnosis of acute hemiplegia in childhood.

Amino Acid Metabolism, Inborn Errors↗
PubMed1990

[Pre- and postnatal diagnosis of organoacidopathies].

Organoacidopathies are the most common life-threatening inborn errors of metabolism presenting acutely in the neonatal period. Early diagnosis rests on a high degree of suspicion. Clinical and laboratory findings are often nonspecific and can be misinterpreted. We present an algorithm for a quick and comprehensive diagnosis of these disorders using commonly available parameters. Different methods for the prenatal diagnosis of organoacidopathies are discussed and our experience with over 150 cases presented. The method of choice is the precise quantification of elevated levels of metabolites in amniotic fluid obtained by amniocentesis at 12-18 weeks of pregnancy. Quantification is best done by stable isotope dilution analysis with the addition of the labelled metabolite to the amniotic fluid. A positive prenatal diagnosis allows a decision of the family for a termination of pregnancy or the immediate institution of therapy after birth. The conduction of a prenatal diagnosis requires the knowledge of the exact diagnosis of a previously affected child.

Acidosis↗
PubMed1989

Apple juice, fructose, and chronic nonspecific diarrhoea.

Apple juice contains fructose and sorbitol, substances that have been shown to be incompletely absorbed by most people. As this might have clinical consequences, especially in young children, we investigated the absorption of the carbohydrate content of apple juice in apple juice consuming toddlers with chronic nonspecific diarrhoea as compared to controls, using the breath hydrogen (H2) test. Incomplete absorption of the carbohydrates from 250 ml of apple juice, as indicated by a maximum breath H2 increase of greater than or equal to 20 parts per million (ppm), was found in all nine patients (mean +/- SEM 57 +/- 8 ppm), and in five out of eight controls (22 +/- 7 ppm) (P less than 0.01). Six patients were retested with apple juice "enriched" with glucose, which is known to improve fructose absorption. The maximum breath H2 increase as well as the area under the breath H2 curve decreased significantly. It was thus estimated that fructose accounted for 80% of the incomplete absorption and sorbitol for 20%. Elimination of apple juice from the diets of the nine patients resulted in normalisation of both the frequency and the consistency of the stools. Incomplete absorption of the carbohydrates, particularly fructose, from apple juice seems to be quite common, and may contribute to chronic diarrhoea in young children.

Breath Tests↗