Biomedical subjects

B Milutinović

Publications and source records attributed to B Milutinović.

9 recordsLinked to original sources

PubMed2001

Reference values of ventilatory variables for healthy adolescents aged 15-19 years.

The main goal of this investigation was the formation of the reference values of ventilatory variables for group of adolescents of both sexes at the age between 15 and 19 years, what was done for the first time for the region of Vojvodina. These values are important in evaluation of respiratory data obtained from patients in the everyday routine examinations. The investigation was carried out on 1151 healthy school children--nonsmokers having the same ethnic origin from the region of Vojvodina. There were 567 males and 584 female participants. Vitalograph dry spirometer (Vitalograph Ltd, Moreton House, Buckingham, England) was used in these examinations. The whole procedure was explained and demonstrated to the participants and best results of their consecutive attempts were taken for further statistical analysis, ie., for calculations of the mean, SD, SEM, coefficient of variation and linear regression. All tests were performed in the morning hours between 8-12 a.m. The results obtained served for calculating the reference values of forced vital capacity (FVC), volume expired in first second of FVC (FEV1.0) and forced midexpiratory flow (FMF). A positive correlation between the respiratory variables and the body height values was found in all groups of participants. The equations of the linear regression related to the ventilatory variables and the height (in 5 cm intervals) were formed separately for both genders. Analysis of the data shows significant differences of the values for all respiratory variables between males and females, which increased with the increasing height of the person. The values for the male group were always higher. In taller volunteers the difference between the sexes becomes even statistically significant, what points that it is necessary to calculate the equations for each gender separately.

Adolescent↗

PubMed1998

Dynamics of granule cells migration into the internal granular layer in developing human cerebellum.

The aim of these investigations was to find out the dynamics of migration of granule cells into the internal granular layer in three different parts of cerebellar cortex. The dynamics of changes was followed in vermis, in lateral hemispheres and in flocculus. For that purpose, 25 fetal brains of different postovulatory age (12.5, 15, 17.5, 19.5, 21, 31 week and one brain of 6 days old newborn) were fixed in formalin, embedded in paraffin, than stained with Cresyl violet and cut in 6, 15 and 30 microm. Each fifth slice was analyzed using the light microscope and numerical density of granule cell nuclei was established by point counting method according to Weibel. Results show a steady increase of the granule cell population in the internal granular layer of all regions investigated, being still greater in vermis and in hemispheres. This increase in the cell number lasted during the whole period of intrauterine development. Moreover, according to the trend of the curves, the increase of the cell number continues even after the birth, suggesting that at least some synaptic connections of granule cells are not established yet. For each region the adequate mathematical model of migration dynamics was calculated.

Algorithms↗

PubMed1996

Regression changes in inferior olivary nucleus compared to changes of Purkinje cells during development in humans.

Human fetal brains were investigated in order to establish the regressional process in two directly dependent structures: in the inferior olivary nucleus and in cerebellar Purkinje cells. Inferior olivary nucleus is the main origin of the climbing fibres, that form one of two direct input systems into the cerebellum. For the purpose 25 fetal human brains at various stages of development (12.5, 15, 16.5 19.5 24, and 31 postovulatory week), together with one brain of newborn (in further text: 41. postovulatory week) were used. Numerical density of nuclei in both regions was determined by stereological technique. In both structures appeared a reduction in the number of nuclei, showing specific dynamics during the intrauterine maturation. The data obtained were analyzed by graphical and numerical method, that allowed the formation of the adequate mathematical models for both structures, that precisely described their regression changes. The data presented indicate that the reduction is very pronounced until the 18-19 postovulatory week, and after that time it is remarkable slowed down. That period is therefore the probable breakpoint of the appearance of synaptic contacts between climbing fibres and Purkinje cell dendrites.

Brain↗

PubMed1992

Regressional changes of human cerebellar cortex and hypoglossal nucleus during development.

In the development of nervous system, two processes are of a particular interest. It is well known that after a primary migration of cells, there appears a consecutive regression in cellular number, closely connected with the maturation of the nervous system. The dynamics of this reduction was investigated following the changes in number of cells in nucleus hypoglossus as well as that of Purkinje cells in two structures of cerebellar cortex--in vermis and in hemispheres. Cell nuclei were counted using the stereological technique, after a usual preparation. Data were collected from 20 human brains of different gestation age, i.e. at 12.5, 14, 17.5, 19.5, 24, 31, weeks of gestation and 6 day old newborn. After the graphical and numerical analysis of the data obtained, an adequate mathematical model was proposed. It is confirmed that a close agreement between biological data and decreasing two-exponential equation can be demonstrated, pointing out that the cellular reduction shows a proportional relation. The possible explanation could be that only the cells forming proper and useful connections and entering the informational system have a privilege to survive, and that all improper contacts lead to the rejection of cells or even of groups of cells.

Cerebellar Cortex↗

PubMed1991

Effect of simultaneous Tc-99m diethyl-IDA and sulfobromophthalein administration on liver excretory function in rats.

Competition of diethyl-IDA and BSP during their synchronous passage through the liver was examined on an animal model. Rats were divided in three groups, according to the amount of diethyl-IDA or BSP administered. No significant influence of diethyl-IDA on the liver uptake of BSP was noticed compared to the controls, while BSP demonstrated a significant inhibitory effect on diethyl-IDA plasma-activity decrease. On the biliary pole of hepatocyte, a reciprocal inhibitory influence of both compounds was present, with significantly diminished biliary excretion of both BSP and diethyl-IDA. As the input of BSP was not decreased, there evidently appeared a storage of BSP within the liver. A mathematical model of both plasma and bile changes of the concentration (or activity) of these compounds was also proposed. For the vascular compartment the model is correct, while biliary excretion of diethyl-IDA is significantly changed in presence of BSP and the satisfactory fit cannot be easily obtained.

Animals↗

PubMed1984

A routine fitting of kinetic data to sums of exponentials with a programmable calculator.

The effects of prolonged ingestion of ethyl alcohol on the elimination kinetics of bromsulphalein (BSP) from the plasma and the excretion of the dye into bile after a single intravenous injection into the circulation of the rat were examined by means of the colorimetrical technique. Simple numerical methods for fitting the experimental data to polyexponential and convex upward functions were also proposed. Two multioptional programs written for the Texas Instrument 59 programmable calculator and for the Sharp 1500 pocket computer were developed which provide for fully automated exponential stripping of pharmacokinetic data and which will allow workers to calculate the numerical values of all the coefficients and exponents for the tracer function fitting the monotone sequences of data.

Alcohol Drinking↗

PubMed1983

Bromsulphalein plasma kinetics after obstruction of the common bile duct in rats: curve fitting with a programmable calculator.

Plasma kinetics of bromsulphalein (BSP) after a single injection into the bloodstream of the rat with total obstruction of the common bile duct was examined. The concentrations of BSP were determined colorimetrically. A monoexponential plus a general first-degree function in time with four unknown parameters was fitted. Two programs were developed for the Texas Instruments 59 programmable calculator to estimate the values of all the parameters by an iteration procedure. The programs executed at about twice normal speed.

Animals↗

PubMed1982

A numerical method for biphasic curve fitting with a programmable calculator.

Elimination kinetics of bromsulphalein (BSP) after a single injection into the circulation of rats were examined by means of a four-compartment model. BSP plasma concentrations were measured colorimetrically. A program written for the Texas Instruments TI-59 programmable calculator is presented, which will calculate the fractional blood clearance of BSP using an iteration procedure. A simple method of fitting biphasic decay curves to experimental data is also proposed.

Animals↗

PubMed1979

Cardiac dynamics during the work load as studied by polycardiography.

Changes in systolic time intervals during the work load point to the differences in their control mechanisms. The exponential decay of the parameters shows sinusoidal oscillations. The number of oscillations is short in cycle length and isometric contraction time; it is the greatest in the ejection period.

Heart↗