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Biomedical subjects

E Knoll

Publications and source records attributed to E Knoll.

At least 73 records · Page 4Linked to original sources
PubMed1978

[Dependence of the serum concentrations of creatinine and urea on the time of day, with normal and impaired kidney function (author's transl)].

Daily variations in the serum concentrations of creatinine, urea and cortisol were studied in 7 patients without kidney or muscle disease, and in 8 patients with impaired kidney function (creatinine clearance less than 40 ml/min). Neither creatinine nor urea showed a circadian rhythm; the daily variations lay within the limits of the methodological scatter. Serum cortisol showed its known circadian rhythm in high amplitude.

Adult↗
PubMed1977

[The IQ of heterozygotes for phenylketonuria (PKU). indication of a blood phenylalanine-independent action of the PKU mutant (author's transl)].

The IQ of parents of phenylketonuria-(PKU-)affected children is lower than that of parents with histidinemia-affected children (control group). The difference arises almost entirely from the verbal part of the Hamburg-Wechsler test. The IQ of the parents with histidinemia-affected children shows the same distribution as that of the normal population; heterozygosity for this condition does not appear to confer any intellectual advantage. In PKU patients treated at an early age and apparently adequately, a slight, but significant decrease in IQ becomes apparent between the ages of 6 and 8 years. This slight decrease also refers mainly to the verbal IQ. At 4 years of age all PKU patients are tested with Bühler-Hetzer, as well as the Kramer test. There is a significant difference between the results in favour of the Bühler-Hetzer test, which is much less verbal. Since heterozygotes for PKU never show elevated blood phenylalanine levels and, moreover, prenatal tyrosine deficiency, as argued by others, seems highly improbable, it is supposed that the PKU gene has a more direct influence on certain ganglion cells at least, with a consequent slight, but significant lowering of the verbal IQ in heterozygotes and satisfactorily-treated homozygotes for PKU. A slightly increased intracellular phenylalanine concentration in heterozygotes and apparently adequately-treated homozygotes need not to be reflected in raised blood levels and this could be an explanation for the observed IQ lowering. But it should not be overlooked that by far the greatest part of damage in PKU patients is caused by chronic phenylalanine poisoning which is well preventable by correct dietary treatment.

Adult↗
PubMed1977

Intellectual level (IQ) in heterozygotes for phenylketonuria (PKU). Is the PKU gene also acting by means other than phenylalanine-blood level elevation?

There is a statistically significant difference in the IQ's of PKU and histidinemia parents. The difference is due entirely to the verbal part of the Hamburg-Wechsler test. There is no significant difference in performance. The heterozygous state of histidinemia does not seem to bear an intellectual (evolutionary) advantage, since the IQ's of histidinemia parents show the same distribution as a normal population. In early and mostly well-treated PKU patients, the same slight deficit in verbal IQ appears with increasing age (changing test methods). These patients, simultaneously tested at 4 years of age with the Bühler-Hetzer and Kramer tests, exhibit a statistically significant difference between the results in favor of the less verbal Bühler-Hetzer. Since heterozygots for PKU never have elevated phenylalanine blood levels, and because tryosine deficiency as argued by others seems highly improbable, we believe that the PKU gene has a more direct action on (or in) at least certain ganglion cells, lowering the verbal IQ slightly but significantly. This action is not reflected by phenylalanine increase in the extracellular space in heterozygots and is not abolished by dietary treatment in homozygous PKU patients. The major damage in PKU patients must be due to chronic phenylalanine poisoning, which deteriorates cells and/or functions on a much larger scale, because it can be easily prevented by decreasing the phenylalanine blood level with correct dietary treatment.

Amino Acid Metabolism, Inborn Errors↗
PubMed1976

[The determination of cystine aminopoptidase (oxytocinase) with a ENI fast analyzer (author's transl)].

A procedure for the determination of cystine aminopeptidase activity was adapted to a fast analyzer. The various reaction parameters were checked. The precision of the method was about 5%. Cystine aminopeptidase activity was stable for long storage periods at +4 degrees C and -20 degrees C. The normal range for the terminal weeks of pregnancy was determined on samples from female patients with normal pregnancies.

Alkaline Phosphatase↗
PubMed1975

[Calculation of the parameters of the acid-base balance with the aid of a small computer].

The application and modification of a program published by Hardt (1972), Clin. Chem. 18,658--661) for the calculation of the true pCO2, the standard bicarbonate and the base excess are reported. 217 Determinations of a random patient sample were evaluated graphically, with the aid of a nomogram of Siggaard-Andersen, and mathematically with a computer program. There was good agreement between the two evaluation methods.

Acid-Base Equilibrium↗
PubMed1975

[Results of a follow up study of small for date babies. II. Mental development (author's transl)].

The second part of the follow-up investigation of 74 small for date babies presents the results of neurological investigation and psychological testing. A correlation was found between the period of the intrauterine noxa and the results. A third of the children in group I (where the intrauterine influences were more severe and more prolonged) had an IQ below average. Minor cerebral damage, poor school performance and mental disturbance were significantly more common than in group II. The EEG-investigation did not contribute additional information. In both groups social factors had an important influence.

Body Height↗