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Journal Article 2005; 26(5): 581-592 PubMed PMID: 16264397 Citation  Keywords:  Animals, Arylalkylamine N-Acetyltransferase:antagonists & inhibitors, Data Interpretation, Statistical, Depression, Chemical, Female, In Vitro Techniques, Melatonin:metabolism, Norepinephrine:antagonists & inhibitors, Perfusion, Pineal Gland:cytology, Rad.   

OBJECTIVES: Cell-permeable and specific inhibitors of melatonin secretion are sill lacking among tools of the pineal research. Recently, a large effort has been made in the development of arylalkylamine N-acetyltransferase inhibitors, but in most cases the new drugs were tested exclusively using cell-free assays or non-pineal cells. The aim of the present study was to characterize the effect of N-bromoacetyltryptamine (BAT), the first synthesized cell-permeable inhibitor of arylalkylamine N - acetyltransferase, on melatonin secretion from rat and pig pineal glands.r />r /> METHODS: The studies were performed in the superfusion cultures of rat and pig pineal explants. Melatonin secretion was determined by radioimmunoassay (RIA).r />r /> RESULTS: BAT strongly inhibited the non-stimulated and norepinephrine - stimulated melatonin secretion from the pig and rat pineal explants, with ED50 0.3 - 0.7 microM. The adrenergic stimulation did not modify significantly the inhibitory potency of BAT on the melatonin release. The decline in melatonin secretion induced by the BAT - treatment was biphasic in both rat and pig pinealocytes, with an initial rapid phase followed by a slow one. The half-time of BAT-induced decline in the non - stimulated and norepinephrine-stimulated melatonin secretion was ca. 25 - 35 minutes. The inhibitory effect of BAT was reversible in pinealocytes of both investigated mammals.r />r /> CONCLUSIONS: The results show that BAT is a potent and reversible inhibitor of the melatonin secretion in the mammalian pineal gland and open the way for the use of this inhibitor in investigations on the pinealocyte physiology performed in vitro....

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Journal Article 2005; 26(5): 593-598 PubMed PMID: 16264396 Citation  Keywords:  Adolescent, Adult, Brain:diagnostic imaging, Cerebrovascular Circulation:physiology, Female, Humans, Klinefelter Syndrome:diagnostic imaging, Male, Middle Aged, Radiopharmaceuticals, Skull:diagnostic imaging, Technetium Tc 99m Exametazime, Temporal Lobe:d.   

OBJECTIVES: In patients with Klinefelter syndrome dissocial behaviour, learning difficulties and low intelligence are common. Thus, the aim of our study was to perform brain perfusion studies and cranial cephalometry in 27 cases of Klinefelter syndrome and compare the results with those in a group of 26 healthy subjects.r />r /> METHODS: Single photon emission tomography (SPECT) was performed after injection of 20 mCi 99mTc-HMPAO and the data from transaxial slices were analyzed for 46 regions of interest in the cerebellar, thalamic, ventricular and parietal planes. Right/ left ratios were calculated and differences above 10 per cent were considered abnormal. Skull radiographs in frontal and lateral view were taken and measurements of the cerebral part were made.r />r /> RESULTS: SPECT imaging in 27 Klinefelter patients revealed 82 hypoperfusion foci, most frequently in temporal regions, less frequently in temporoparietal and frontal regions, whereas only 11 hypoperfusion foci in 6 of the 26 control subjects were found. Skull radiography revealed the following abnormalities : flattening of the temporal regions, reduced width of the vault, shortening of the anterior cranial fossa and definitely reduced angle of the cranial base; all these anomalies differed significantly from those in the skulls of the control subjects.r />r /> CONCLUSIONS: The high coincidence of the location on the temporal regions of brain perfusion defects and the neurocranial shape anomalies indicate that an extra X chromosome in Klinefelter patients has detrimental effects on the temporal lobe development and function....

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Clinical Trial 2005; 26(5): 599-602 PubMed PMID: 16264395 Citation  Keywords:  Adult, Emotions:physiology, Humans, Hydrocortisone:metabolism, Male, Memory:physiology, Saliva:metabolism,.   

OBJECTIVES: The aim of this study was to examine (i) the influence of cortisol on both prospective and retrospective memory performance and (ii) the role of emotional valence in both types of memory.r />r /> METHODS: Thirty-four male students participated in a memory task, which measured both prospective and retrospective memory performance. Baseline salivary cortisol levels were assessed.r />r /> RESULTS: Spearman's rank order correlation analysis showed a significant positive correlation between salivary cortisol levels and retrospective memory performance for neutral words. Cortisol levels were not significantly correlated with prospective memory performance for either negative nor neutral words.r />r /> CONCLUSIONS: The present results indicate chronic cortisol levels are positively associated with retrospective memory at relatively low concentration ranges, but not prospective memory, in healthy young men. Implications for evaluating the beneficial effects of low-dose cortisol treatment on posttraumatic stress disorder is discussed....

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Journal Article 2005; 26(5): 603-608 PubMed PMID: 16264394 Citation  Keywords:  Adolescent, Adult, Birth Weight:physiology, Breech Presentation, Cesarean Section, Female, Humans, Infant, Newborn, Myasthenia Gravis:physiopathology, Pregnancy, Pregnancy Complications:physiopathology, Retrospective Studies, Thymectomy, Thyroiditis, Auto.   

OBJECTIVE: The aim of the study was to evaluate the effect of Myasthenia gravis (MG) on the course of pregnancy, labor and delivery, and the condition of neonate.r />r /> DESIGN AND SETTINGS: Retrospective chart review of pregnant patients with MG hospitalized in tertiary care center over 12 year period was performed. Course of MG before and during pregnancy, mode of delivery, and condition of the newborn were analyzed.r />r /> RESULTS: There was 42 913 deliveries in the Polish Mother's Research Institute in Lodz during analyzed period. Thirteen patients with MG were identified, giving the incidence of 3/10 000 live births. Mean age of the patients was 28 years, range 18 - 36 years. Average time since diagnosis was 9 years. Eleven women with MG delivered at term (one twin pregnancy), and two babies were born prematurely. In seven patients pregnancy was ended via normal spontaneous vaginal delivery (NSVD), one was forceps extraction, four patients had elective Cesarean Section (CS), and two had emergency CS. Indications for CS were purely obstetrical. Spontaneous vaginal deliveries were speedy. None of the patients had exacerbation of MG during current pregnancy. Mean birth weight of the newborns was 3014,3 g, range 1730 g to 3700 g. Mean Apgar score was 8,7 at 1 minute and 8,9 at 5 minutes. Only one neonate (second twin) developed Transient Neonatal Myasthenia Gravis (TNMG).r />r /> CONCLUSIONS: Myasthenia gravis did not have significant effect on the course of pregnancy or mode of delivery. In the twin pregnancies it is possible that only one twin will present with the symptoms of TNMG....

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Journal Article 2005; 26(5): 609-616 PubMed PMID: 16264393 Citation  Keywords:  Aluminum:antagonists & inhibitors, Animals, Antioxidants:therapeutic use, Apoptosis:drug effects, Brain:metabolism, Lipid Peroxidation:drug effects, Male, Malondialdehyde:metabolism, Melatonin:therapeutic use, Nerve Degeneration:pathology, Neurofibrils:pa.   

OBJECTIVE: The present study was aimed to investigate: (1) the neurotoxic oxidative damage of orally administered aluminum chloride (AlCl3) in rabbits (Biochemical and morphopathological studies). (2) The effect of melatonin as an antioxidant and free radical scavenger on oxidative neuropathic changes.r />r /> METHODS: Thirty-five male rabbits were divided into 4 groups (A, B, C [10 animals each] and D [5 animals]). Group A received AlCl3 (20 mg/l via drinking water for 3 months). Group B received AlCl3 for 3 months then administered with melatonin (10 mg/kg b.w. sc daily for 15 days). Group C received AlCl3 plus melatonin for 3 months. Group D received the solvent and served as control. Malondialdehyde (MDA) and 4-hydroxyalkenals (4-HDA) as lipid peroxides as well as superoxide dismutase (SOD) as an antioxidant enzyme were measured. Aluminum residue in the brain tissue was measured spectrophotometerically. The morphopathological changes were also examined by light and electron microscopes.r />r /> RESULTS: MDA and 4-HAD were significantly increased in group A versus those of controls while significantly decreased in groups B and C compared with those of A group. SOD run in an opposite manner. Aluminum concentration was significantly increased in groups A, B and C when compared with group D while it significantly decreased in groups B and C when compared with that of group A. The neuropathlogical examination in the animals of group A revealed atrophy and apoptosis of the neurons in cerebral cortex and hippocampus. This was associated with neurofibrillary degeneration as well as argyrophilic inclusion. Schwan cell degeneration and nerve fiber demylination were also encountered. The elaboration of lipid peroxidation products, inhibition of antioxidant enzymes and the morphopathological changes were minimized in the Al/Mel treated groups and markedly improved in Al+Mel treated groupr />r /> CONCLUSION: Chronic aluminum exposure in rabbits had dramatic encephalopathic morphopathological lesions. It enhances the lipid peroxidation production and inhibits the SOD enzyme. Melatonin had a good prophylactic effect as an antioxidant in aluminum encephalopathy....

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Journal Article 2005; 26(5): 617-623 PubMed PMID: 16264392 Citation  Keywords:  Cholesterol:blood, Coronary Disease:epidemiology, Diabetes Mellitus:epidemiology, Disease, Endorphins:physiology, Exercise:physiology, Health, Humans, Hyperlipidemias:epidemiology, Hypertension:epidemiology, Mental Health, Osteoarthritis:epidemiology, Ost.   

: It is known for a long time that exercise increases physical adequacy, has beneficial effects on the general health condition as well as a playing preventing role against various disease states. To decrease the risk of disease and maintain good health, the natural defense system of the organism needs to be strengthened. It is thought that in addition to increasing the body's resistance to disease through the strengthening of the immune system, decreases the convalescence time, increases work efficiency and improves the sportive performance of the individual all which would contribute positively to the national economy. The positive effects of regular exercising of aerobic nature such as strengthening of the immune system, protection against diseases as well as its positive effects on quality of life will help to emphasize the importance of physical exercise and improve the general view of sports by society....

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Journal Article 2005; 26(5): 453-458 PubMed PMID: 16264391 Citation  Keywords:  Animals, Animals, Newborn:physiology, Arcuate Nucleus of Hypothalamus:cytology, Body Weight:physiology, Eating:physiology, Electrophysiology, Hypothalamic Hormones:pharmacology, Hypothalamus:cytology, In Vitro Techniques, Intracellular Signaling Peptides .   

OBJECTIVES: Hypothalamic neurons of rats overweight due to early postnatal overfeeding (SL) differ from those of control rats in their responses to feeding relevant hormones like leptin or insulin. The question arose whether prolactin and prolactin-releasing peptide (PrRP) express also differential action in SL rats. These peptides are described to have an effect on food intake and body weight regulation. Prolactin is co-synthesized in lateral hypothalamic neurons together with orexins that were also analyzed in this study.r />r /> METHODS: Single unit activity was extracellularly recorded in brain slices from adult control rats (CL) and from rats previously raised in small litters (SL). The action of the peptides on the firing rates was evaluated in the medial parvicellular part of the paraventricular nucleus (PaMP) and the medial arcuate nucleus (ArcM).r />r /> RESULTS: In control rats, PrRP significantly activated PaMP neurons, whereas prolactin and orexin-A induced also inhibition. In SL rats, there was a significantly different effect of orexin-B on PaMP neurons: the main effect changed from activation in controls to inhibition. ArcM neurons of both control and SL rats were mainly excited by prolactin and orexins.r />r /> CONCLUSION: Changes acquired during early development of neuronal responses to feeding relevant peptides are not a general non-specific mechanism of neurochemical plasticity, but concern specific hypothalamic nuclei and/ or hormones and neuropeptides. The increase in inhibition by orexin-B of hypothalamic paraventricular neurons could in vivo contribute to the neonatally acquired disposition towards persistingly increased food intake and reduced energy expenditure of overweight SL rats....

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Comparative Study 2005; 26(5): 459-462 PubMed PMID: 16264390 Citation  Keywords:  Animals, Female, Injections, Intravenous, Injections, Intraventricular, Leptin:administration & dosage, Ovariectomy, Pituitary Hormones:blood, Radioimmunoassay, Rats, Rats, Inbred WKY,.   

OBJECTIVE: It has been reported that leptin plays an important role in the regulation of food intake and energy expenditure. There are controversial opinions about effects of leptin on the hormonal system. The aim of this study was to estimate the effect of leptin on pituitary hormones release after central and peripheral administration.r />r /> METHODS: Leptin was injected intracerebroventricularly (icv) in a dose of 0.5 microg/5microl aCSF (artificial cerebrospinal fluid) for 5 min in Wistar Kyoto rats. At 60 and 120 min after injections the animals were decapitated. Leptin in a dose of 10 microg in 300 microl of saline was administered intravenously (i.v). At 60 mins the animals were decapitated. Serum rLH, rFSH, rPRL, rTSH, rGH concentrations were measured with RIA methods.r />r /> RESULTS: After central (icv) injection of leptin we observed an increase of rGH, rTSH and a decrease of rPRL. However, after peripheral (iv) injection of leptin we found a decrease of rGH and rTSH and an increase of rPRL. We did not find any significant changes in LH and FSH after icv and iv injection of leptin.r />r /> CONCLUSIONS: The opposite effects of leptin on pituitary hormones release were observed due to the method of leptin administration. Leptin may play a modulating role in the mechanism of pituitary hormones release....

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