The value of P300 event related potentials in the assessment of cognitive function in subclinical hypothyroidism.

BACKGROUND: Mild hypothyroidism (thyroid stimulating hormone [TSH] less than 10 mIU/L) induces reversible cognitive dysfunction, which can be evaluated by event related potentials (ERP). So far, only little is known about the impact of subclinical hypothyroidism on ERP as electrophysiological markers of cognitive activity. The aim of this study was to follow-up P300 latencies and amplitudes in patients with subclinical hypothyroidism and to evaluate the influence of thyroxine treatment which led to the normalization of TSH level in serum. METHODS: We recorded the P300 wave using an auditory oddball paradigm in 60 patients (mean age 51.1±6.2 years, range 40-62 years), with subclinical hypothyroidism (normal mean value of FT4, with elevated TSH levels) at baseline, after 3 months, after 6 months and in 30 healthy control subjects. 30 patients treated six months with L-thyroxine until the normalization of TSH and 30 patients received placebo. RESULTS: The P300 latencies in patients with subclinical hypothyroidism were significantly longer, and the P300 amplitudes were significantly smaller than those of the control group. In the thyroxine treated patients P300 latency continuously decreased over the observation period with a significant difference after 6 months compared to baseline (P<0.01). The amplitude P300 showed no significant changes over time. CONCLUSIONS: Our results show the importance of P300 event related potentials in the detection of cognitive changes in patients with hypothyroidism. The P300 latency stands out as a marker for cognitive function recovery during treatment with thyroxine.

The role of P300 event-related potentials in the cognitive recovery after the stroke.

The aim of this study was to elucidate the effects of an ischemic stroke on the amplitude and latency of the P300 wave and evaluate their changes over a prospective 1-year follow-up period. We recorded the P300 wave using an auditory oddball paradigm in 60 consecutive brain infarct patients at baseline (i.e., within 4 weeks after the stroke), after 3 months, after 12 months and in 30 healthy control subjects. The P300 latencies in stroke patients were significantly longer and the P300 amplitudes were significantly smaller than those of the control group. The latency of P300 showed a highly significant average improvement 12 months after the stroke compared to the baseline. There was no significant change observed for the P300 amplitude during the same period. The P3 latency is initially more increased in the patients with hemispheric brain infarction but shows a better recovery compared to the patients with brainstem infarction. Also, the results of the P300 latency of patients with the left-sided lesions was significantly longer compared to the patients with right-sided lesions on the beginning of the study but not 3 and 12 months after the stroke. The results of our study show the importance of P300 event-related potentials in the detection and follow-up of cognitive changes after ischemic stroke.

Heterophoria and fusional convergence and divergence in preschool children.

AIM: To determine the prevalence of heterophoria, fusional convergence and divergence values and the degree of relationship between heterophoria and fusional vergence in preschool children. METHODS: For assessment of far and near heterophoria in 152 children aged 6-7, cover and prism cover tests were used. Far and near fusional vergences were measured by step vergence testing using prism bars. RESULTS: Orthophoria (-tropia) with the average values of heterophoria around 0 PD (prism diopter) were most common at far, and exophoria around 2 PD at near. The average break values of far fusional convergence and divergence were 13.7 ± 4.4 PD and 7.3 ± 2.1 PD, respectively. Near fusional convergence and divergence break values were 29.6 ± 6.6 PD and 16.2 ± 4.1 PD, respectively. The recovery values were from 1/3 to 1/2 lower than the break values. The correlation between heterophoria at far and far fusional convergence and heterohoria at near and near fusional convergence and divergence was weak, yet significant (r = 0.18 - 0.26; p less than 0.05). CONCLUSION: In preschool children the prevalence of heterophoria, and values of fusional vergence were in the ranges of values for elementary school children and adults cited in the literature. Heterophoria and fusional convergence at far, and heterophoria and fusional vergences at near have shown a weak relationship.

Effects of St John's wort (Hypericum perforatum L.) extracts on epileptogenesis.

The purpose of this study was to investigate the effects of treatment with water, n-butanol and ether extracts of Hypercom perforatum L. on epileptogenesis in rabbits. Animals from the control group received solvent-ethanol, and the kindling model of epilepsy was used. Epileptic focus was induced in Chinchilla rabbits by stimulation of the hippocampus. The following parameters were determined: the minimum current strength necessary to induce after-discharge (AD) - discharges appearing after cessation of stimulation; AD duration; the number of stimulations necessary to induce spontaneous kindling; and the latency time for the development of full kindling. The results obtained indicate that epileptogenesis is influenced by Hypericum perforatum L. extract treatment. Animals treated with an ether extract of Hypericum perforatum L. required significantly weaker minimum current strengths for the development of epileptogenic focus, and displayed longer AD times, while the number of electro-stimulations necessary for full kindling was less. In contrast, animals treated with water and n-butanol extracts required increased electro-stimulations for the development of epileptic discharge, and displayed shortened AD durations versus controls.

Risk of the recurrent headache and migraine appearance within the family.

AIM: The aim of this research was to determine the risk for family appearance of the recurrent headache (non-migraine and migraine). METHODS: The research was conducted in Vojvodina, the Northern Province of Serbia. The population of Vojvodina is around 2 million people belonging to more than 20 different ethnic groups. During the 20-year period (1988-2008), 30,363 children aged 3 to 17 years were tested, independent of their place of birth. The presence of headaches similar to those tested was compared among all the members of the family within three generations. RESULTS: Positive family data of the recurrent headaches were detected among 98.6% children with migraine headaches, 64.7% children with non-migraine headaches, and 32.4% children without recurrent headaches. The relation among the members of the nuclear family (contingency quotient of 0.429) was significantly stronger than the relation to the members of wider family (contingency quotient of 0.338). CONCLUSIONS: The probability of a child having the migraine headache rather than the non-migraine one was very high for parents and high for father's mother, while it was not significant for mother's mother, mother's father and father's father, having similar recurrent headaches.

[Effects of calcium antagonists on brain ischemia].

INTRODUCTION: Stroke is the second leading cause of death in the world and the leading cause of serious, long-term disability in adults; about half of those who survive become dependent on others in performing personal activities of daily living. Ischemia disturbs calcium cellular homeostasis, whereas calcium channel blockers re-establish it. This study was aimed at assessing benefits of calcium channel blockers on the outcome of rehabilitation of the patients afflicted by ischemic stroke. MATERIAL AND METHODS: The functional independence was measured by the Barthel index in 90 patients subjected to rehabilitative therapeutic treatment. The functional recovery of patients treated with calcium channel blockers and with other drugs (control) was compared and tested. RESULTS: The analysis of variance (ANOVA) for the 0.5 confidence interval showed that the increases of the Barthel index values were significantly higher in the patients treated with calcium antagonists (p < 0.5). DISCUSSION: According to the literature, such an outcome is the result of improved brain blood flow auto-regulation, increased brain perfusion as well as of neuroprotective, antioxidative, platelet anti-aggregatory effects of investigated drugs. CONCLUSION: The calcium channel blockers improved the outcome of rehabilitative therapeutic treatment significantly in the patients afflicted by ischemic stroke.

Comparison of the hypotensive and bradycardic activity of ginkgo, garlic, and onion extracts.

The acute effect of ethanol extracts ginkgo (Ginkgo biloba L.), garlic (Allium sativum L.), and onion (Allium cepa L.) on arterial blood pressure (BP), and heart rate (HR) in anesthetized normotensive rats was examined and compared. Arterial BP was registered in the left carotid artery. The data showed that intravenous administration of the extracts produced dose-dependent and reversible hypotensive and bradycardic effects. The most effective in reducing arterial BP and HR is extract of garlic. There were statistically significant differences in bradycardic and hypotensive effects of the garlic and ginkgo extracts.

Inhibitory effect of aqueous and ethanolic garlic (Allium sativum L., Lilliaceae) extracts on the rat atria.

The acute negative inotropic and chronotrophic effects of aqueous and alcoholic garlic extracts (Allium sativum L.) on spontaneous and adrenalin-stimulated contractions of the Wistar rat atria were investigated. The addition of garlic extracts to isolated rat atria evoked negative inotropic and chronotropic effects. Ethanolic garlic extract exerts much stronger negative inotropic (58.33 +/- 14.76%) effects than aqueous extract (43.66 +/- 16.32%). The difference in frequency reduction is especially conspicuous. Aqueous garlic extract very slightly affects the frequency, while ethanolic extract reduces it by more than 40%. In addition to these effects, the positive inotropism and chronotropism induced by the addition of noradrenaline, were much more antagonized by ethanolic garlic extract than by aqueous extract. Moreover, ethanolic garlic extract establishes sinus rhythm in the atria with extrasystoles induced by noradrenaline.

Inhibitory effect of Ginkgo biloba extract on the tonus of the small intestine and the colon of rabbits.

Ginkgo biloba is widely used in folk medicine. Patients very often use the plant preparation with no concern for purity. They also tend to increase the dosage by themselves and this may result in certain insufficiently researched acute effects. Due to this extremely widespread application, the aim of this work is an examination of the possible acute effects of Ginkgo bilobaon the motility of the small and the large intestine of rabbits. capital TE, Cyrilliche effects of Gingium - a standardized ginkgo biloba extract (GBE) [one milliliter preparation contained 8.8-10.8 mg ginkgo flavonol glycoside and 2.0-2.8 mg lactone ring-containing terpenes (ginkgolides and bilobalides)], on the tonus of isolated segments of the ileum and the colon of rabbits were examined. The experiments were carried out on isolated bowel incisions according to the Magnus method. Data was registered by physiography (Narco-Bio-System). Our results show that GBE (0.006 g/L, - 0.06 g/L) concentration-dependently reduces the tonus of the ileum and the colon of rabbits. Apart from that, GBE reduces the increase of the tonus of the ileum caused by acetylcholine (ACh), but does not change colon tonus intensified by ACh. This indicates that the effects of the used extract in the ileum are predominantly achieved through cholinergic mechanisms, while the relaxant effects in the colon are achieved in some other way.

[Relaxant activity of aqueous and ethanol extracts of parsley (Petroselinum crispum (Mill) Nym. ex A. W Hill, Apiaceae) on isolated ileum of rat].

INTRODUCTION: Parsley (Petroselinum crispum) is used in the traditional herbal medicine to treat intestinal disorders. The aim of this study was to examine the effect of aqueous and ethanol extracts of parsley on spontaneous and acetylcholine induced contractions on isolated rat ileum. MATERIAL AND METHODS: Wistar albino rats (250-300 g) were used in this study. The ileum portions were isolated out and cleaned off mesenteries. Preparations 2 cm long were mounted in 20 ml tissue baths containing Tyrode's solution maintained at 37 degrees C and aerated with a mixture of 5% carbon dioxide in oxygen. In the first part of experiments, contractile responses to the aqueous (ethanol) extracts of parsley were recorded. In the second part, increasing concentrations of acetylcholine were added to the organ bath for a full concentration response curve and then concentration response curves were obtained after adding the aqueous (ethanol) extracts of parsley. RESULTS AND DISCUSSION: Our results showed that aqueous (62.22 +/- 7.15%) and ethanol (79.16 +/- 9.34%) extracts of parsley in dose dependent manner decreased the tonus of spontaneous contractions of isolated rat ileum. The aqueous (32.16 +/- 2.75%) and ethanol (53.96 +/- 4.86%) extracts of parsley reduced the acetylcholine induced contraction, the reduction was greater with ethanol extract than with the aqueous one. CONCLUSION: It can be concluded that the aqueous and ethanol extracts of parsley exert antispasmodic activity on rat ileum. The relaxant effect of ethanol extract was better comparing to aqueous extract of parsley.

Effect of 12-monoketocholic acid on modulation of analgesic action of morphine and tramadol.

This work is concerned with the potential promotive action of 12-monoketocholic acid (12-MKC) on the analgesic effect of morphine and tramadol. The investigation was carried out on laboratory Wistar rats divided into five test groups, each treated with either morphine (2 mg/kg), tramadol (9.6 mg/kg), 12-MKC (2 mg/kg), morphine + 12-MKC, or tramadol + 12-MKC, the control group receiving physiological solution (2 mg/kg). The effect of 12-MKC on the analgesic action of morphine and tramadol was determined by radiation heat method. Morphine and tramadol, given in equimolar doses, did not show significant difference in the degree of analgesia. In combination with morphine, 12-MKC increased significantly the analgesic effect compared with the group treated with morphine alone. However, 12-MKC caused no change in the action of tramadol. The 5-day intravenous application of 12-MKC in combination with the two analgesics caused no changes in the biochemical parameters nor pathohistological changes in the liver parenchyma of tested animals.

Effects of mistletoe (Viscum album L., Loranthaceae) extracts on arterial blood pressure in rats treated with atropine sulfate and hexocycline.

Acute effects of different extracts of mistletoe stem (Viscum album) were investigated on values of arterial blood pressure in Wistar rats. Arterial blood pressure was registered by direct method in the left carotid artery and the investigated extracts (total ethanol, ether and ethyl acetate) of mistletoe stem were administered into the right jugular vein. The total ethanol extract exhibited the best effect even on the lowest applied concentration (3.33 x 10(-5) mg kg(-1)) and significantly decreased the blood pressure after applied concentration 1.00 x 10(-3) mg kg(-1). On the contrary, the ether and ethyl acetate extracts exhibited notable activity only by higher administered doses. Atropine as a nonselective blocker of muscarinic receptors reduced the hypotensive effects of ethanol extract of mistletoe. Hexocycline, a selective blocker of muscarine receptors, significantly raised blood pressure and decreased the hypotensive effect of ethanol extract of mistletoe on arterial blood pressure in rats.

The effect of Ginkgo biloba (EGb 761) on epileptic activity in rabbits.

Different animal models are used to evaluate the process of epileptogenesis. In this investigation the kindling model of epilepsy was used. The epileptic focus was induced in Chinchilla rabbits by stimulation of the hippocampus with electric stimuli. We presumed that the extracts of Ginkgo biloba affect the formation of kindling epilepsy. Bioelectric activity of the brain was registered throughout the development of kindling with and without standardized extracts from dried ginkgo leaves (EGb 761). For each animal the following has been determined: the values of the minimum current strength necessary for the origination of threshold after-discharge (AD) - discharges appearing after the cessation of stimulation; duration of the threshold AD; number of stimulations necessary for the origination of full kindling; time latency for the development of full kindling; number of spontaneous epileptogenic discharges manifested in EEG two days following the formation of full kindling during 60-minute registration. The results show that the process of epileptogenesis was influenced by EGb 761. It has been established that if the animals received EGb 761, significantly weaker minimum current strength was necessary for the development of the epileptogenic focus and the AD were longer, while the number of necessary electrostimulations for the appearance of full kindling was less and the latency was shorter.

[Event-related potentials following exercise bouts of different intensity].

INTRODUCTION: A number of articles on physical activity analyze the effects of acute bouts of physical exercise on the whole body. These experiments mainly include questionnaires and measurements of reaction time. The use of event-related potentials in laboratories for functional diagnostics is only of recent date. The aim of this experiment was to give insights into the impact of physical activity of different intensity on the amplitude and latency of P300 cognitive potentials. MATERIAL AND METHODS: After recording cognitive event-related potentials in 17 young (21.6+/-1.07 yrs) healthy adults (at Fz and Cz), the participants underwent a controlled bicycle ergometer exercise. Each exercise lasted 10 minutes, with successive increase in the intensity to 60%, 75% and 90% of the maximum pulse rate and maintaining this level of intensity for six minutes. Immediately after each bout of exercise, event-related potentials were recorded. RESULTS: The amplitude of the P300 wave, following exercise intensity at 75% of the maximum pulse (Pmax) (Fz 15.00+/-4.57, Cz 18.63+/-8.83 mV ) was statistically higher (p<0.05) than the amplitude of the P300 at rest (Fz 11.21+/-4.15 mV; (Cz 13.40+/-8.04 mV), at 60% (Fz 11.86+/-5.11 mV; Cz 14.54+/-8.06 mV) and at 90% of maximum pulse (Fz 13.26+/-4.73 mV; Cz 14.91+/-8.91 mV). There were no statistically significant differences (p>0.05) between amplitudes at 60% of Pmax and values obtained at rest and at 90% of Pmax. Also, no statistically significant differences were recorded (p>0.05) among the latencies of P300 recorded at rest (Fz 323.57+/-3.24 ms; Cz 323.57+/-13.24 ms) and at 60% of Pmax (Fz 321.14+/-22.38 ms; Cz 321.86+/-22.88 ms), at 75% of Pmax (Fz 321.50+/-16.67 ms; Cz 322.50+/-14.60 ms) and at 90% of Pmax (Fz 326.29+/-7.85 ms; Cz 325.43+/-7.63 ms). DISCUSSSION AND CONCLUSION: Physical activity has a positive impact on cognitive functions. At intermediate intensities, the amplitude of P300 increases, but at submaximal intensities it decreases to values obtained at rest. However, the latency of P300 did not show a statistically significant change after different intensities of exercise.

[Effects of ginkgo biloba extract on an experimental model of epilepsy]. / Uticaj ekstrakta gingko bilobe na eksperimentalni model epilepsije.

INTRODUCTION: The active ingredients of ginkgo biloba extracts were determined by biochemical analyses in the last ten years and they are widely used in classical medicine. The active substances of ginkgo biloba extract, mostly affect muscarinic receptors and adrenergic receptors to a lesser degree. Recently, potential effects of ginkgo biloba on NMDA receptors and on epileptogenic seizures have been considered. The main goal of this research was to investigate effects of ginkgo biloba extracts on the experimantal model of epilepsy. MATERIAL AND METHODS: The research was carried out on chinchilla rabbits. GINGIUM solution was used with 40 mg in 1 ml of dry extract of ginkgo biloba leaves. The epileptogenic area was formed by stimulating hippocampus. Bioelectrical activity was registered 60 minutes before the epileptogenic area was formed as well as 90 minutes later. Ginkgo biloba extract was given via i.m, in a single daily dose of 1 ml/kg/BW. RESULTS: A statistically significantly higher frequency of paroxysmal seizures was established after usage of ginkgo biloba. CONCLUSION: According to the results obtained in this research, we can conclude that ginkgo biloba extracts have a proconvulsive activity.

[The effect of age on the sense of smell in health individuals]. / Uticaj zivotnog doba na mirisnu funkciju kod zdravih ispitanika.

INTRODUCTION: A need for research of the olfactory function exists in everyday clinical work. The aim of this study was to determine standards for perception and identification thresholds regarding olfactory substances in healthy subjects in regard to their age. MATERIAL AND METHODS: The research included 120 healthy examinees (60 women and 60 men) classified according to age into three age groups (20-30, 31-40, 41-50 years of age). This examination was done using Fortunato-Niccolini's method. RESULTS AND DISCUSSION: The results of this work show that olfactory function becomes significantly weaker after the age of forty. Thresholds of perception in correlation with thresholds of identification for examined olfactory substances are significantly lower in older age groups. CONCLUSION: A gradual loss of olfactory capability with age can be explained by gradual destruction of olfactory cells and fibres of olfactory nerves during life.

[Olfactory perception in women with physiologically altered hormonal status (during pregnancy and menopause]. / Osecaj mirisa kod zena u fizioloski izmenjenim hormonalnim stanjima (u trudnoci i postmenopauzi).

INTRODUCTION: Olfaction is considered to be the ability to: perceive, conduct and recognize scents and odors. With its numerous connections to the limbic system and reticular formation, the olfactory system affects regulation of numerous vegetative functions, visceral functions and sexual behavior. Since estrogen and progesterone protect the olfactory function, changes in their levels in particular physiological states in women (in pregnancy and posmenopause) exert an influence on the ability to feel and recognize smells. It has its role in creating emotions and adjustment of visceral and vegetative response to particular emotional states. Also, it represents the connection between higher cortical functions and the endocrine system. MATERIAL AND METHODS: Our investigation was performed at the Ear, Nose and Throat Clinic in Novi Sad. The research included 80 healthy women classified into 4 groups; 20 women aged between 20 and 30; 20 women in the first trimester of pregnancy aged between 20 and 30; 20 premenopausal women aged between 41 and 50; and 20 women at least 3 years in postmenopause, aged between 41 and 50. For our research we used an olfactometer and the Fortunato-Niccolini method. RESULTS AND DISCUSSION: In pregnancy the thresholds of perception (TP) and identification (TI) of examined substances were slightly lower in comparison to nonpregnant women of the same ages, but without any statistical significance (p > 0.05). In climacteric-postmenopausal women there was a significant decrease of olfactory ability in comparison to nonmenopausal women of the same ages (p < 0.01). CONCLUSION: All changes of the olfactory function in pregnancy are explained by mental changes of pregnant women as well as their hormonal status. Significant decrease of olfactory ability in postemnopause is explained by decline in sexual hormone levels.