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Biomedical subjects

M Uluitu

Publications and source records attributed to M Uluitu.

At least 19 recordsLinked to original sources
PubMed1975

Relationship between bovine serum albumin structure and its chemical equilibria with hydrogen and 5-hydroxytryptamine ions.

From the analysis of titration curves with hydrogen and 5-HT ions, it was found that the electrostatic interaction parameter of protein macroion and the number sites of 5-HT fixing were smaller over an acid and base pH range as compared to their values at neutral pH. Our data were interpreted by the conformational changes which can be induced when BSA is exposed to denaturation by acid and alkali pH.

Animals↗
PubMed1975

Determination of blood serum protein reactivity in children with behavior disturbances.

The researches were carried out on two groups of children: normals and with behavior disturbances. The serum cationic state was determined by an original method, using heparin as cautions exchanger in physiological pH, and the protein reactivity; the electrophoretic mobility of serum proteins at pH 7.4; total soduim and serum proteins. The obtained results show that serum proteins in children with behavior disturbances differ from those of normals, having: 1) smaller number of serotonin-fixing sites, 2) higher strength interaction between the serotonin and proteins, 3) lower resistance to the denaturant agents which has as a consequence the increase of cationic activity in the serum, and an increased electrophoretic mobility. The data are discussed and interpreted as perturbations in the electrolytes exchange (Na+, especially) in the integration centres of the autonomic functions.

Adolescent↗
PubMed1975

Serotonin through pregnancy. Comparative researches in different species and in mankind.

By spectrofluorimetric method there was followed the blood and cerebral serotonin content in different species of mammalians: in 28 women, from the venous whole blood collected by cubital puncture, and in 20 cows, from the jugular whole blood. In 90 female rats the serotonin content from hypothalamus, rhinencephalon, mesencephalon, and sensorimotor cortex was determined. The obtained data show that in the course of labour in both species the blood serotonin concentration is decreased, returning to its initial values after delivery. The serotonin concentration in cows is 10--15 times higher than in women. As concerns the serotonin values in the cerebral nuclei through pregnancy, a progressive and significant increase of its content was noted in the hypothalamus, rhinencephalon, and mesencephalon, but not in the cerebral cortex. It reaches its maximum concentration at the end of pregnancy. It was concluded that during pregnancy a reduction of serotonin release processes is produced, which can signify a lower functional level of the serotoninergic structures implied in the regulation of the reproductive functions. The data are interpreted in the light of the particular endocrine state existing through pregnancy, attributing to serotonin a role in the functioning of PIF-prolactin system.

Animals↗
PubMedDate not supplied

The influence of auditory and lithium stimulation on blood and brain serotonin in the normal rat and in that susceptible to audiogenic convulsions.

Investigations were carried out in two groups of male rats: a group susceptible to audiogenic convulsions and a control group. The following parameters were determined under basal conditions and 24 and 48 hours after intraperitoneal administration of a single lithium carbonate dose (0.67 mEq/animal), before and after auditory stimulation: serotonin content in the blood and brain tissue (separately from the hypothalamus, rhinencephalon, midbrain and sensory-motor cerebral cortex) by fluorimetry: water-saline retention, renal potassium elimination, the dynamics of renal lithium elimination. The results showed that in the rats prone to audiogenic convulsions, blood serotonin concentrations are twice those in the controls, whereas serotonin levels in the brain are lower than in the controls. The administration of lithium is followed by a decrease in blood serotonin in the animals with audiogenic convulsions but does not influence the serotonin content in the brain. Acoustic stimulation does not influence the behaviour of the controls but induces convulsions in the animals sensitive to noise. After auditory stimulation under basal conditions or 48 hours after the administration of lithium a decrease takes place in cerebral serotonin and an increase in blood serotonin in the controls whereas in the rats sensitive to noise, cerebral serotonin increases and blood serotonin decreases on stimulation under basal conditions due to the convulsions and metabolic alterations induced by the latter. These findings suggest the existence of different mechanisms for the transport of serotonin in the blood of rats prone to audiogenic convulsions. These mechanisms may be influenced either by acid catabolites resulting from convulsive activity or by the administration of lithium. The latter may induce persistent alterations in the blood transporter, as appears to result from the observation at 48 hours after the administration of lithium.

Acoustic Stimulation↗
PubMedDate not supplied

EEG automatic processing method.

This is a description of researches carried out in man and experimentally in rats. The results - obtained in 44 children aged between 12 and 14 yr. - of the electric signal processed as a F/A ratio were compared to the transport mechanisms of the blood sodium. We found that the normal brain excitability level was consistent only with the blood sodium transport through interaction with the proteins. The lack of such interaction was accompanied by an increased excitability on eeg recordings and by behaviour disturbances. The researches carried out in rats had in view the brain excitability level in two groups of animals aged 6-8 months, which drank from their birth either physiological salt (group 1) or distilled water (group 2). In this species, in spite of direct visible modifications in eeg recordings by sensorial stimulation, the processing as F/A ratio did not show any differences, and this made necessary the use of computers to process rightly the data; the respective digitization and memorising methods are described, too.

Adolescent↗