Wavelet and fractal analysis of rat brain activity in seizures evoked by camphor essential oil and 1,8-cineole.

We investigated the rat brain activity in acute seizures evoked by camphor essential oil or its main constituent 1,8-cineole by wavelet (primarily) and fractal analysis. Experiments were performed on anesthetized animals before and after intraperitoneal camphor oil or cineole administration. The properties of frequency bands in pre-ictal, ictal and inter-ictal stages have been determined by wavelet analysis. The domination of delta frequency band was confirmed in obtained brain activities, which participate with approximately 45% of mean relative wavelet energy (MRWE) in control signals and arise up to approximately 76% MRWE in energy spectrum during the ictal stage (after drug administration). Other frequency bands decreased during ictal stage and arised in inter-ictal stage. There was a dosedependent response of cineole effect: increase in cineole concentration leaded to the higher values of relative wavelet energy (RWE) of delta frequency band while there were slight changes of the mean fractal dimension (FD) values as a measure of system complexity.

The righting reflex from a supine to a prone position in the guinea pig fetus.

The aim of this study was to examine the righting reflex from a supine to a prone position in the albino guinea pig fetus. Ultrasound examinations of one-fetus gestations were performed in the period from the 31st to the 66th day of gestation. The experimental and control group each encompassed 6 fetuses. Fetuses were brought into supine positions relative to the gravity vector by manipulating the pregnant females into the appropriate positions. The control group received 15 mg/kg of diazepam intraperitoneally before the examination to show whether changes in fetal position occurred as the result of passive rotation. In the experimental group, each fetus was examined every other day (summary results: absent 69 times, prone position 10 times, lateral position 29 times). In the control group, each fetus was examined every five days (summary results: absent 42 times). The absence of the righting reflex in the control group was statistically significant (chi(2) = 18.66, df = 1, p = 0.000, p < 0.05). The experimental group fetuses assumed a prone position more frequently in the period from the 51st to the 66th day of gestation than in the period from the 31st to the 50th day of gestation (chi(2) = 4.17, df = 1, p = 0.0412, p < 0.05), suggesting maturation of the righting reflex.

Estimation of parameter kmax in fractal analysis of rat brain activity.

We recorded electrocortical activity in anesthetized rats and constructed k(max) new self-similar time series, applying Higuchi's algorithm. The aim of this study was to estimate value of the parameter k(max) in order to obtain fractal dimension values as an optimum measure of biosignal change. After our analysis, electrocortical activity recordings resulted in a family of curves f(k(max)). Three regions could be distinguished 2 < or = k(max) < 8, with a U-shape; 8 < or = k(max) < or = 30, with a steeper quasilinear increase; and k(max) > or = 30, with a smaller slope quasilinear increase. We suggest the optimum region for k(max): 8 < k(max) < 18, specifically k(max) = 8.

Spectral analysis of cerebellar activity after acute brain injury in anesthetized rats.

We investigated cerebellar electrocortical activity before and after unilateral brain injury in anesthetized rats. Spectral analysis of cerebellar activity was obtained by Fast Fourier Transformation. There was a dominance of delta frequency range, while the wide gamma range presented no more than 5% of the total mean power spectra of cerebellar activity before brain injury. A few minutes after brain injury and within the first 90 minutes, there was a decrease of total mean power spectra and a relative decrease of delta range power to about 30%, some increase of beta range, and an increase of gamma range to 20-25%. Relative increase of gamma range in the cerebellar mean power spectra was still present 120 min after the brain injury, while other changes started to diminish. We suggest that spectral changes within slow and fast (gamma) frequency ranges of cerebellar activity may be indicators of the brain state after acute injury.

[Influence of demographic and socioeconomic characteristics on the quality of life].

INTRODUCTION: The quality of life is a multidimensional concept, which is best expressed by the subjective well-being. Evaluation of the quality of life is the basis for measuring the well-being, and the determination of factors that determine the quality of life quality is the basis for its improvement. OBJECTIVE: To evaluate and assess the determinants of the perceived quality of life of group distinguishing features which characterize demographic and socioeconomic factors. METHODS: This was a cross-sectional study of a representative sample of the population in Serbia aged over 20 years (9479 examinees). The quality of life was expressed by the perception of well-being (pleasure of life). Data on the examinees (demographic and socioeconomic characteristics) were collected by using a questionnaire for adults of each household. To process, analyze and present the data, we used the methods of parametric descriptive statistics (mean value, standard deviation, coefficient of variation), variance analysis and factor analysis. RESULTS: Although men evaluated the quality of life with a slightly higher grading, there was no statistically significant difference in the evaluation of the quality of life in relation to the examinee's gender (p > 0.005). Among the examinees there was a high statistically significant difference in grading the quality of life depending on age, level of education, marital status and type of job (p < 0.001). In relation to the number of children, there was no statistically significant difference in he grading of the quality of life (p > 0.005). CONCLUSION: The quality of life is influenced by numerous factors that characterize each person (demographic and socioeconomic characteristics of individual). Determining factors of the quality of life are numerous and diverse, and the manner and the strength of their influence are variable.

[Characteristics of reproductive health of women in their generative age].

INTRODUCTION: Any research of reproductive health has to encompass the relevant connotations of this complex term. In order to establish relevant multidimensional characteristics, it is necessary to assess intercorrelations of the characteristics most commonly used to describe it. OBJECTIVE: Our aim was to describe the characteristics of reproductive health and to establish their significance in describing this term. METHODS: Within the study of health of adult inhabitants of Serbia, on the sample of 2,817 women aged 20-49 years, the data on different reproductive health characteristics were collected by way of a structured questionnaire. By way of factorial analysis (principal components method, Kaisser Varimax criterion), representative characteristics (factors) were selected out of a large number of characteristics, describing reproductive health of women in a multidimensional way, interrelationships of the factors were explained, and carriers--the most important individual characteristics--were selected for further analysis. RESULTS: The characteristics of female reproductive health in Serbia are poor, both from the health policy standpoint and in comparison with other countries. Reproductive health describes 7 relevant factors and their carriers (characteristics which best reflect the variability of characteristics involved in a factor). These involve sexual behaviour (self-assessed HIV infection risk), contraception (use of contraceptive devices on one's own initiative), adequate protection of reproductive health (usage of gynaecological services even when healthy), abortions (pregnancy outcome), HIV control (HIV testing usage), postpartal protection (visits of field nurses after being discharged from maternity ward) and reproductive period (doctor visits after being discharged from maternity ward). CONCLUSION: All the characteristics of reproductive health used in various studies are not equally important in the description of this complex phenomenon. Factorial analysis can explain intercorrelations of the studied characteristics and make possible the selection of those most representative.

[Determinants of the most significant characteristics of reproductive health].

INTRODUCTION: Reproductive health of women is determined by females' demographic and socio-economic characteristics, their behaviour, and the complex of environmental factors. OBJECTIVE: The paper examines the predictive impact of personal and environmental characteristics, health and healthcare characteristics regarding the most important aspects of reproductive health. METHODS: From a sample of 2,718 women, aged 20-49 years, we collected information on various characteristics using a structured questionnaire. Based on factorial analysis (principal components method, Kaisser Varimax criterion) we selected representative variables (factors), describing personal (demographic and socio-economic) characteristics of women, their environment (family, household, community), health (attitudes towards health, life-style, health status), healthcare (independent) and the characteristics of reproductive health (dependent variables). The predictors were analyzed by multiple regression and correlation. RESULTS: Sexual behaviour was determined by socio-economic status, personal tidiness, rest, presence of risk factor(s), health evaluation and attitude toward personal responsibility, trust in physicians etc. The predictors of contraception involved satisfaction with one's own health, serious health problems, health evaluation. The presence and number of abortions were determined by personal psychological maturity, rest, risk factors, life-style, health evaluation and its manifestations, and the continuity and timely healthcare.The predictors of adequate protection of reproductive health involved the cultural level of the community, financial standing of the household, satisfaction with one's own life, tidiness and rest, presence of risk factors, health evaluation, attitude towards personal responsibility, and trust in physicians. HIV control was determined by satisfaction with one's own life, physical activity of women, presence of serious health problems, and the content of primary healthcare. Postpartal protection was determined by the cultural level of the community, reasons for dissatisfaction with one's own life, presence of risk factors and deficiencies, and timely contraception. The predictors of reproductive period duration are availability of health care in a community and personal tidiness of women. CONCLUSION: The study confirmed predictive impact of most of the studied characteristics.

Spectral and fractal analysis of cerebellar activity after single and repeated brain injury.

The cerebellum, even when not directly damaged, is potentially interesting for understanding the adaptive responses to brain injury. Cerebellar electrocortical activity (ECoG) in rats was studied using spectral and fractal analysis after single and repeated unilateral injury of the parietal cortex. Local field potentials of cerebellar paravermal cortex were recorded before brain injury, in the acute phase (up to 2.5 hours) after a first injury of anesthetized rats, and then before and after second, third, and, in some cases, fourth injury. Relative gamma power (32.1-128.0 Hz) and fractal dimension of ECoGs were temporarily increased after the first injury. However, there was a permanent mild increase in gamma activity and a mild increase in the fractal dimension of cerebellar activity as a chronic change after repeated remote brain injury. There was a negative linear correlation between the normalized difference in fractal dimensions and normalized difference in gamma powers of cerebellar activity only in the case of repeated brain injury. This is the first study showing that correlation between the parameters of spectral and fractal analyses of cerebellar activity can discriminate between single and repeated brain injuries, and is, therefore, a promising approach for identifying specific pathophysiological states.