Search NEL Online

Comparative Study 2011; 32(4): 518-525 PubMed PMID: 21876492 Citation  Keywords:  Adult, Body Mass Index, Cholesterol, HDL:blood, Cholesterol, LDL:blood, Cognition:physiology, Diabetes Mellitus, Type 1:complications, Diabetes Mellitus, Type 2:complications, Female, Hemoglobin A, Glycosylated:metabolism, Humans, Male, Memory Disorders:e.   

OBJECTIVES: The goal of the study was an evaluation of differences in working memory effectiveness between patients with type 1 and type 2DM. It was also attempted to ascertain whether the level of diabetes control is associated with working memory effectiveness.

METHODS: 62 subjects were enrolled into the study. All patients were divided into two groups: patients with type 1DM (n=31) and with type 2DM (n=31). The Trail Making Test (TMT) and the Stroop Test were used for evaluation of working memory effectiveness. Diabetes control indicators included: glycated haemoglobin (HbA1C) level, total cholesterol concentration, HDL and LDL cholesterol concentration and body mass index (BMI).

RESULTS: The patients with type 1DM obtained a significantly lower time in the execution of TMT, part B (p=0.01) and of RCNb (p=0.01) and NCWd (p=0.01) versions of the Stroop Test, while making significantly less errors in NCWd version (p=0.01). Significant correlations were demonstrated between BMI values and the rate of execution of TMT, part B (p=0.03), as well as the rate of execution of RCNb (p=0.04) and NCWd (p=0.01) versions of the Stroop Test. Total cholesterol level was significantly correlated with the rate of execution of TMT, part A (p=0.04) and B (p=0.01). No significant correlations were found between cholesterol fraction levels in blood of the studied patients and the results of performed tests, with one exception, regarding the relationship between LDL cholesterol fraction and the rate of the Stroop Test execution in RCNb version (p=0.04).

CONCLUSIONS: 1). Higher working memory efficacy was demonstrated among the patients with type 1DM vs. those with type 2DM. 2). The level of diabetes control is an influential factor for working memory effectiveness in diabetic patients....

Read abstract  Full text PDF

Journal Article 2011; 32(4): 563-572 PubMed PMID: 21876489 Citation  Keywords:  Female, Gastrointestinal Hormones:genetics, Gene Expression:physiology, Humans, Myometrium:physiology, Placenta:physiology, Pre-Eclampsia:etiology, Pregnancy, RNA, Messenger:metabolism, Receptors, G-Protein-Coupled:genetics, Signal Transduction:physiology.   

OBJECTIVE: Preeclampsia (PE) is a hypertensive complication of the pregnancy. In our study we investigated the expression, localization, and signaling pathways of PK1 and PKR1 in third-trimester human placenta and myometrium and assessed the correlation between the PK1 and PKR1 expression and signaling and the incidence of the PE.

MATERIALS & METHODS: We designed two study groups: pregnant PE patients and healthy, pregnant women. After collection, tissue was placed in RNAlater for RNA extraction, fixed in 4% neutral buffered formalin, and wax embedded for immunohistochemistry or placed in RPMI and transported to the laboratory for in vitro culture. We have collected and processed placental and myometrial biopsies from 40 patients - 19 were PE patients.

RESULTS: Only the PK1 mRNA expression comparison between PE and CTRL in placenta showed statistically significant difference (p=0.004). There was statistically significant difference in cell signaling in myometrium controls in 30 minutes after ligand. The rise in pERK/tERK ratio is clearly visible in time intervals 20 and 30 minutes in controls, although with no statistical significance. There was no difference in PK1 and PKR1 localization in the placenta and myometrium in the groups.

CONCLUSIONS: The number of PKR1 is not reduced in PE. The reduced PK1 mRNA expression is not than dependent on PKR1 mRNA expression. The data shows that ST produces much more PK1 in healthy pregnant women than those suffering from PE. We can conclude that in PE the production of PK1 is impaired and so are the endocrine functions of the ST....

Read abstract  Full text PDF

Journal Article 2011; 32(4): 481-486 PubMed PMID: 21876488 Citation  Keywords:  Adult, Attention:physiology, Cognition:physiology, Female, Humans, Male, Memory, Short-Term:physiology, Motor Cortex:physiology, Photic Stimulation:methods, Psychomotor Performance:physiology, Theta Rhythm:physiology, Time Perception:physiology, Transcran.   

OBJECTIVES: Supplementary motor area (SMA) was suggested to have a dominant role in the temporal control of behavior by many neuroimaging studies. The aim of this study was to support this hypothesis by influencing time estimates with theta burst transcranial magnetic stimulation (TMS) over the SMA.

METHODS: Nineteen healthy volunteers with a mean age 25.9±3 (SD) years performed the time reproduction task (TRT) before and after 190 seconds of intermittent theta-burst TMS over SMA and the precuneus (total 600 pulses). The TRT consisted of an encoding phase (during which visual stimuli with durations of 5, 10 and 16.82 seconds were presented pseudorandomly) and a reproduction phase (during which interval durations were reproduced by pressing a button). Mean subjects' interval estimates as a measure of accuracy and standard deviation as a measure of variability pre-TMS and post-TMS were compared.

RESULTS: Theta-burst TMS over both areas had no effect on the accuracy of duration estimates. An increased variability of interval reproduction was present after stimulation of the precuneus (p<0.01) with the biggest effect on the five second interval. Stimulation of SMA caused a decrease of variability in the ten second interval only (p<0.05).

CONCLUSION: It is likely that increased variability of time estimates is a non-specific result of impaired attention and working memory after theta-burst TMS. Decreased variability after stimulation over the SMA could be explained in terms of enhanced activity of the physiological oscillator with a frequency close to 0.1 Hz....

Read abstract  Full text PDF

Journal Article 2011; 32(4): 510-517 PubMed PMID: 21876486 Citation  Keywords:  Animal Feed, Animal Nutritional Physiological Phenomena:physiology, Animals, Animals, Suckling:growth & development, Colostrum:metabolism, Dietary Supplements, Esters:pharmacokinetics, Eukaryota, Fatty Acids:pharmacokinetics, Female, Iodine:pharmacokineti.   

OBJECTIVES: The aim of the study was to compare iodine utilization from different sources by sows and their progeny and the levels of T3 and T4 in their serum.

DESIGN: Pregnant Czech Large White × Landrace sows were fed with an experimental KPK diet (a diet for lactating sows) 14 days before parturition until weaning (at a piglet age of 28 days). In group A (n=50, 10 sows, 40 piglets) the feed was supplemented with KI (0.6 mg of iodine per kg of feed). Iodine enriched alga Chlorella spp. (0.6 mg of iodine per kg of feed) was used as a supplement in group B (n=50, 10 sows, 40 piglets). In group C (n=50, 10 sows, 40 piglets) the sows were injected i.m. with IFAE at a dose of 100 mg of iodine per sow. Iodine, T3 and T4 were measured in each group for comparison of iodine utilization.

RESULTS: The use of IFAE resulted in higher serum concentrations in sows compared to KI and alga. In contrast, iodine concentrations in milk and piglets were lower when IFAE were used. We found a wide variation in the concentrations of T3 and T4 in the serum of piglets in all groups.

CONCLUSION: Our results indicate a good utilization of iodized oil by sows. However, its transfer into milk is lower compared to the other iodine sources....

Read abstract  Full text PDF

Journal Article 2011; 32(4): 487-490 PubMed PMID: 21876485 Citation  Keywords:  Animals, Behavior, Animal:drug effects, Disease Models, Animal, Electroencephalography, Epilepsy, Absence:chemically induced, Grooming:drug effects, Male, Mastication:drug effects, Motor Activity:physiology, Rats, Rats, Sprague-Dawley, Veratridine:toxicit.   

OBJECTIVES: Veratridine was characterized previously as an experimental model of epilepsy in vitro. The aim of this preliminary investigation is to identify the pattern of seizure induced by this model in vivo.

MATERIAL AND METHODS: Veratridine (200 μg/kg) was administered intraperitoneally to male Sprague-Dawley rats and the electrical activity of the brain was recorded as surface electroencephalogram (EEG).

RESULTS: The animals developed behavioral effects manifested as grooming, masticatory movements, facial automatism and wet dog shakes (WDSs). There were episodes of complete quiescent periods for 2-5 minutes before the animals presumed activity which were repeated every 15-20 minutes. The seizure activity during this silent activity showed fast frequency signals in the surface EEG correlating with absence seizure. The WDS behaviour was associated with electrical spikes on the EEG. When the rats were pre-treated with 200mg/kg ethosuximide (ETX), EEG recordings did not display the same fast frequency signal as that observed in animals receiving veratridine only. The number and duration of WDSs were not altered by ETX (200-400 mg/kg).

CONCLUSION: Veratridine produced an absence like-seizure activity in the surface EEG, sensitive to ETX and correlates with its behavioural effects....

Read abstract  Full text PDF

Journal Article 2011; 32(3): 221-225 PubMed PMID: 21712792 Citation  Keywords:  Adolescent, Algorithms, Behavior, Addictive:psychology, Choice Behavior, Economics, Humans, Nonlinear Dynamics, Psychophysics, Time Perception:physiology,.   

: Neuroeconomic conditions for "rational addiction" (Becker & Murphy 1988) have been unknown. This paper derived the conditions for "rational addiction" by utilizing a nonlinear time-perception theory of "hyperbolic" discounting, which is mathematically equivalent to the q-exponential intertemporal choice model based on Tsallis' statistics. It is shown that (i) Arrow-Pratt measure for temporal cognition corresponds to the degree of irrationality (i.e., Prelec's "decreasing impatience" parameter of temporal discounting) and (ii) rationality in addicts is controlled by a nondimensionalization parameter of the logarithmic time-perception function. Furthermore, the present theory illustrates the possibility that addictive drugs increase impulsivity via dopaminergic neuroadaptation without increasing irrationality. Future directions in the application of the model to studies in neuroeconomics are discussed....

Read abstract  Full text PDF

Journal Article 2011; 32(3): 301-307 PubMed PMID: 21712789 Citation  Keywords:  Adult, Aldosterone:blood, Blood Pressure:physiology, Diet, Sodium-Restricted, Female, Goiter, Nodular:drug therapy, Graves Disease:drug therapy, Humans, Hyperthyroidism:blood, Hypothyroidism:blood, Potassium:blood, Renin:blood, Sodium:blood, Thyroid Funct.   

OBJECTIVE: The influence of thyroid hormones upon renin-angiotensin-aldosterone system is poorly understood. Under basal conditions, individuals belong to normal, low or high plasma renin activity (PRA) subjects. The study was designed to evaluate basal and poststimulatory PRA and serum aldosterone (Aldo) level in patients with hyperthyroidism or hypothyroidism during therapy.

MATERIAL AND METHODS: We examined 73 women with hyperthyroidism, 27 women with hypothyroidism and 36 healthy controls. The patients were investigated before initiation of therapy and after attainment of euthyroid state. All subjects were investigated under basal conditions (normal-sodium diet) and after application of a low-sodium diet for three days and upright position for 3 hr. PRA, serum Aldo level, blood pressure, serum sodium, potassium and thyroid hormone levels were determined in all subjects. The subjects were classified as low PRA (<1.0 ng/ml/h), normal PRA (1.0-4.0 ng/ml/h) and high PRA (>4.0 ng/ml/h) individuals according to results obtained under basal conditions.

RESULTS: Relatively higher poststimulatory enhancement in PRA was found in patients with hyperthyroidism, especially those with low basal PRA, than in those with hypothyroidism. In women with thyroid dysfunctions poststimulatory increase in Aldo were relative lower than poststimulatory enhancement of PRA. After therapy these difference disappeared. The poststimulatory changes in PRA depended on the basal PRA.

CONCLUSIONS: Poststimulatory PRA is higher in hyperthyroid women, especially those with low basal PRA. In women with hypothyroidism, basal and poststimulatory PRA is low. Blood pressure and severity of thyroid dysfunction was found to be similar in the patients with low, normal or high basic PRA. In women with thyroid dysfunctions, serum Aldo level and its relative poststimulatory increments are inadequate to changes of PRA; it is suggested that the dissociation in the renin-angiotensin-aldosterone system occurs in hyperthyroid and hypothyroid women....

Read abstract  Full text PDF

Journal Article 2011; 32(3): 354-359 PubMed PMID: 21712788 Citation  Keywords:  Adult, Age of Onset, Attention:physiology, Cognition:physiology, Cognition Disorders:etiology, Executive Function, Female, Humans, Learning:physiology, Male, Memory:physiology, Middle Aged, Neuropsychological Tests, Psychomotor Performance:physiology, Spi.   

OBJECTIVES: Cognitive disorders and dementia occur in 19 to 42% of patients with spinocerebellar ataxia type 2 (SCA2). Neuropsychological tests can reveal executive dysfunction, impaired visual and verbal memory, tongue and speech impairment, attention disorders and impaired verbal fluency.

METHODS: We performed psychiatric and neuropsychological examinations in 12 patients diagnosed with genetically confirmed SCA2 and 12 healthy volunteers matching the patients in age, gender, and length of education. The level of motor impairment was determined using the brief ataxia rating scale (BARS). The neuropsychological examination focused on testing executive functions, short-term visual and verbal memory, attention, psychomotor tempo, visual motor coordination, learning ability and comprehension ability. The tests were divided into two subgroups according to the difficulty of motor tasks. The cognitive abilities composite score (CACS) was determined by calculating the arithmetic mean of T scores of the respective tests.

RESULTS: Patients with SCA2 had significantly lower CACSs (p=0.00005) compared to the healthy volunteers. Patients exhibited impaired performance in both difficult and simple motor tests. The severity of cognitive impairment was related to the age at the onset of the disease (p=0.002) but not to the duration or to the overall BARS score.

CONCLUSIONS: Compared to healthy volunteers, patients with SCA2 exhibited significantly worse cognitive performance in all areas tested, including the tests of simple motor tasks. Moreover, the cognitive performance of patients worsened as the difficulty of the motor tasks increased....

Read abstract  Full text PDF