Immobilization of tyrosinase on poly(indole-5-carboxylic acid) evidenced by electrochemical and spectroscopic methods.

A conducting, polymeric film of poly(indole-5 carboxylic acid) has been prepared by electrochemical polymerization for covalent immobilization of an enzyme belonging to the family of phenoloxidases-tyrosinase. The polymer was characterized by cyclic voltammetry, UV-VIS and Raman spectroscopy in a buffer solution. As the polymer contains pendant carboxylic groups one-step carbodiimide method was used to immobilize tyrosinase on the polymer matrix. Immobilization of tyrosinase was confirmed by surface enhanced resonance Raman scattering spectra (SERRS) and by cyclic voltammetry as well. Tyrosinase was shown to retain its biological activity when being immobilized on the polymer surface. As proved by the electrochemical and spectroelectrochemical (UV-VIS) experiments, tyrosinase covalently bonded to the polymer matrix effectively catalyzes oxidation of catechol. The reduction current of o-quinones was measured as a function of catechol concentration. The linear dependence was found to be 15 microM of catechol with sensitivity of 250 mA/M cm2.

[Characteristics of sleep EEG abnormalities in children with phenylketonuria during the first year of life]. / Charakterystyka cech nieprawidlowych zapisów elektroencefalograficznych snu w pierwszym roku zycia u dzieci z fenyloketonuria.

350 sleep EEG recordings in PKU children in the first year of life were analysed in order to characterize the abnormal features. Recordings were taken from serial studies carried out during the last 8 years on early and late treated children. Only quiet sleep was evaluated due to its longer duration after the second month of life and its important developmental characteristics. The criteria of abnormality were the following: lack of bioelectric features of sleep, abnormal " trac é alternant ", and other criteria of defined range, character and morphology. The number of abnormal records was referred to the three periods of the first year of life: first and second trimester, and the second semester of the first year of life, and also to treatment. EEGs before treatment were considered as records of untreated children. Table 1 compares the number of normal and abnormal records according to age and treatment. Table 2 illustrates the character and the range of abnormalities with reference to age and treatment. Tables 3, 4, 5, give the characteristics of morphological features of abnormal records. Our previous papers describe EEGs of PKU children of different age during waking and sleeping, while the present study is the evaluation of EEGs in children of the same age recorded in sleep only. The choice of these criteria is justified by the greatest variability of EEG records in relation to developmental factors and activating role of sleep. Among all EEGs, 60% were recorded during treatment. The biggest number of EEGs recorded in untreated children was obtained in the first three months of life and became gradually less. About 70% of the records were normal. No difference was noted between the number of normal and abnormal EEG records in different periods of the first year of life. The number of normal records was considerably higher in treated children than the number of abnormal records in untreated ones. This relationship was not noted in the first three months of life. In the first half year of life, generalized abnormalities as well as abnormal " trac é alternant " predominated and localized abnormalities were exceptional. On the other hand, in the second half year of life nearly half of the abnormalities were as follows: general paroxysmal abnormalities not observed in the first half year of life, considerably higher amount of abnormalities localized only in the temporal region, less generalized non-paroxysmal abnormalities, and lack of bioelectrical features of sleep.(ABSTRACT TRUNCATED AT 400 WORDS)

[Convulsions in phenylketonuria and the pattern of the bioelectric activity of the brain]. / Zagadnienie napadów dragawkowych w fenyloketonurii obraz czynnosci bioelektrycznej mózgu.

Serial EEC investigations were carried out in 30 children with phenylketonuria aged 8 months to 4 years at the time of dietary treatment. All children had seizures. The results of EEG investigations in this group of children were compared with a preciously observed analogous of 35 children without convulsions. Comparing the results of EEG investigations in both groups it was observed that in the group of children without convulsions the initial EEG tracings were mostly normal while in both groups the abnormalities were mostly of paroxysmal type. On the ground of an analysis of the EEG results of both groups of children during the whole observation period lasting 2 to 7 years no statistically significant differences were observed in the pattern of bioelectric activity of the brain in both groups. In the light of this material homogenous from the standpoint of aetiology and pathogenesis the asuthors postulated the necessity of verification of the presently accepted principles of diagnosis and classification of infantile convulsions based on diagnostic and prognostic significance of EEG investigations.

[Seizures in phenylketonuria]. / Zagadnienie napadów drgawkowych w fenyloketonurii. Spostrzezenia kliniczne.

In a group of 90 children with phenylketonuria diagnosed and treated late the authors studied the problem of seizures. They occurred in over 50% of children, in most of them they had the character of salaam seizures (72%). They were statistically significantly more frequent in children with more severe mental retardation. In the discussion on these observations the authors stated that the data obtained by them concerning the frequency of seizures (twice as frequent as in materials reported in the literature) were based on long-term observation of these children and not on one examination and they conform better to the actual incidence of these seizures. It is supposed that the presence of seizures is a prognostically unfavourable element. It is suggested also that these children should be given anticonvulsant treatment besides dietary treatment of phenylketonuria.

[Attempt to evaluate the bioelectrical function of the brain and the mental development of twin pregnancy children (author's transl)]. / Próba oceny czynnosci bioelektrycznej mózgu i rozwoju psychicznego dzieci z ciaz blizniaczych

EEG records and psychological examinations were performed in 30 twin pairs, 9 of which were monozygotic and 21--dizygotic twins, aged 1 to 13 years. No data on disturbances in C.N.S. functions or somatic diseases were found on the basis of anamnesis in 5 pairs, but in 25 pairs the abnormalities were stated in the perinatal period febrile and infantile convulsions and head injury were also found. Normal EEG records were found in 5 pairs; in 6 pairs one of the children showed a normal record, while the other--an abnormal one, and in the remaining 19 pairs abnormal records were found (Table I). Totally similar EEG records were found in 11 pairs, and dissimilar ones in 19 pairs. The development quotient (D.Q.) or intelligence quotient (I.Q) amounted to 80-90 points in only 5 children, while in the others there was 90-110 and over. In 18 pairs the quotient values were similar, and in 12 pairs different (Table II). In pairs with equal values of the quotients qualitative differences were found in the functions measured. The similarities and differences in EEG records and also in D.Q. and I.Q. For monozygotic and dizygotic twins are illustrated by Table III. The authors analysed the similarities and differences in EEG records and D.Q. and I.Q. in twin pairs in relation to two groups of children. Group I includes 5 pairs of twins without data on C.N.S. function disturbances and group II--25 pairs in which there were factors which could damage the function of C.N.S. A predominance of similar EEG records and of similar values of quotients was found, in the I group irrespective whether they were monozygotic or dizygotic twins (Table IV). In group II, however, there were considerably less similar EEG records and similar quotient values and, moreover, qualitative differences were found in the functions measured. Similarities in monozygotic twins in opposition to the dizygotic ones were found in EEG records (Table V). The authors state that, despite the predominance of abnormal EEG records in the examined twins, no mental deficiency was found in any of the children. The EEG records differed more in the twins than the psychomotor development quotients, but similarities in the records were greater than those of the quotients in monozygotic twins. Concomitantly with similar numerical values of psychomotor development quotients there were qualitative differences of the functions measured. The greatest differences in EEG records and quotient values were found in pairs of twins in which data were found on factors which could disturb the function of the C.N.S. as well as in dizygotic twins.