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J Srajer

Publications and source records attributed to J Srajer.

41 records · Page 3Linked to original sources
PubMed1975

Ontogenetic patterns of frequency-power spectra elicited by flickering light in children: a comparative study of evoked and background EEGs.

Frequency-power spectra of the EEG evoked by repeptitive photic stimulation and of the background EEG were studied during childhood in 43 awake subjects aged between 2 months and 14 years. EEG activity was recorded from the middle parieto-occipital region with the aid of a 1-channel analyzer Lysograf-Alvar, analysing 16 frequencies in the range from 2 to 28 c/sec. The responsiveness of the central nervous system to flickering light improved in the course of childhood in parallel with the significant decline of delta activity and with the prominent increase of alpha intensity in the resting EEG. The 4th month of life appeared to be a marked turning point in the development of evoked and background EEGs. From that age, the bioelectric power at the flash rate corresponding to photic "driving" began to increase together with the highest and optimal driving frequencies. The flash rate, at which evoked potentials changed into the "driven" rhythm, also shifted towards higher frequencies. Subsequently, the amount of energy in the resting EEG increased significantly within the theta, alpha and beta bands and, on the contrary, a prominent decline was observed in the delta range. Marked ontogenetic changes at this age closely coincided with the rapid development of exogenous fibres in the occipital cortex, including the thalamo-cortical conncetions, and fibres of the neuropil in cortical layer I, which might play an important role in the genesis of background and "driven" in the occipital region.

Adolescent↗
PubMedDate not supplied

Heterogeneity of pepsinogens in the urine of children.

The existence of a significant linear relationship between the concentration of chlorides and the activity of pepsinogen (PG) in the urine was ascertained in the case of full-term infants 3 days to 6 weeks of age. At the age of 4-6 weeks, a significant relationship was found between the urinary pepsinogen activity and the urinary creatinine concentration, and between the urinary pepsinogen activity in the urine and the urine osmolality. Immediately after birth, the Pg7 fraction of PG II in the urine was found in all cases and, at the age of 4-6 weeks, in 11% of cases. In regard to the time factor, the conspicuous drop in the occurrence of the Pg7 fraction corresponds to the new qualitative relationship between the pepsinogen activity in the urine and the creatinine concentration in the urine and between the former and the urine osmolality. In premature infants, the Pg7 fraction disappears more slowly. The spectrum of pepsinogens in the urine was examined in children suffering from various diseases. In a girl with lymphoma, we found the Pg7 fraction, but this finding was temporary only.

Aging↗
PubMedDate not supplied

Lung function abnormalities in cystic fibrosis and changes during growth.

Static lung volumes (VC, TLC, FRC, RV), elastic recoil pressure of the lungs (Pst(1) at 100, 90, and 60% of TLC), static lung compliance [Cst(1)], specific airway conductance at FRC level (Gaw/TGVex), forced expiratory volume in the first second (FEV1), maximal expiratory flows (Vmax.) at 25 and 50% of VC and at 60% of TLC, and "upstream" airway conductance (Gus) at 60% of TLC were studied in 28 patients with cystic fibrosis, 5 to 25 years old, over a period of 1 to 5 years. The data were compared individually with normal values, related to body height in the form of regression equations and expressed in percentage of predicted values. From the indices assessing airway function, Vmax. at low lung volumes, Gus at 60% TLC, RV and RV/TLC were the functional parameters most consistently abnormal. Among the indices characterizing lung elasticity, Pst(1) at 60% TLC was the most abnormal. Generally, the values of the majority of lung function indices [VC, TLC, FRC, Pst(1)] declined during growth. Vmax. at all lung volumes and Gus at 60% TLC did not deteriorate with growth probably due to the great abnormality of these parameters already in young patients. It was also observed that lung function did not change significantly over a period of 1 to 5 years corresponding to a 10 cm increase in body height. However, over that period, lung function improved in some of the subjects, did not change in over 50% of the cases and deteriorated in the others.

Adolescent↗