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Journal Article 2004; 25(6): 407-410 PubMed PMID: 15665800 Citation  Keywords:  Action Potentials, Animals, Entropy, Intralaminar Thalamic Nuclei:physiology, Male, Models, Neurological, Neuralgia:physiopathology, Nonlinear Dynamics, Rats, Rats, Wistar, Rhizotomy,.   

OBJECTIVES: A novel evaluative approach was used to determine single unit activities of non-bursting intralaminar thalamic nuclei under neuropathic pain state following dorsal rhizotomy.

SETTINGS AND DESIGN: Extensive dorsal rhizotomy at cervicothoracic level in rats was used as a model of central pain. After rhizotomy, rats were divided into two groups: rats without any signs of self-mutilation, and those presenting self-mutilation. Spontaneous single unit activities of neurons of intralaminar thalamic nuclei were recorded and interspike intervals (ISIs) of non-bursting cells were counted for both groups and compared with that of non-rhizotomized control rats. Chaodynamic methods were applied for the evaluation of the ISIs.

RESULTS: In control rats Lyapunov exponents, Shannon entropy and mutual information average values were significantly higher than those of rhizotomized rats without any signs of self-mutilation. Paradoxically, in animals presenting self-mutilation following rhizotomy the evaluated parameters were similar to those of controls. Further, Lyapunov exponents were positive values in all animals indicating chaotic pattern of the neuronal firing.

MAIN FINDINGS: 1. Neurons behave in chaotic way in all animals, 2. The most regular firing was found in non-mutilating rhizotomized animals, 3. Patterns of the firing in selfmutilating rats were similar to those in controls.

CONCLUSIONS: It is concluded that pain feeling is not executed neither by changes of chaotic dynamics of non-bursting intralaminar thalamic neurons. On the other hand, the paradoxical firing of the neurons under pathological brain matrix might participate in modification pain feeling....

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Clinical Trial 2004; 25(5): 340-348 PubMed PMID: 15580167 Citation  Keywords:  Adult, Antidepressive Agents:therapeutic use, Brain Mapping, Cerebral Cortex:diagnostic imaging, Cognitive Therapy, Female, Fluorodeoxyglucose F18, Functional Laterality, Humans, Male, Neuropsychological Tests, Panic Disorder:diagnostic imaging, Positron-.   

BACKGROUND: The goal of our study was to identify brain structures in patients with panic disorder (PD) that show changes in 18FDG PET during the treatment with cognitive behavioral therapy (CBT) or antidepressants.

METHOD: Twelve patients suffering from panic disorder were studied with [18F]-2-fluoro-deoxyglucose positron emission tomography (18FDG PET) scanning during resting state (condition of random episodic silent thinking, REST). After PET examination patients were randomly assigned to either cognitive behavioral treatment group (6 patients) or antidepressants treatment group (6 patients). After a 3 month period 18FDG PET examination was repeated in both groups. Psychopathology was assessed using the rating scales HAMA, CGI and Panic Disorder Severity Scale (PDSS). Data were analysed using software for statistical parametric mapping (SPM99).

RESULTS: The scores of psychopathology rating scales (CGI, HAMA, PDSS) decreased in both groups. Changes of 18FDG uptake in the pharmacotherapy group: decreases were found in the a priori hypothesized regions in the right hemisphere, in the superior, middle, medial and inferior frontal gyrus, superior and middle temporal gyrus, and increases were detected in the a priori hypothesized regions, mainly in the left hemisphere in medial and middle frontal gyrus, superior, middle and transverse temporal gyrus. Changes of 18FDG uptake in the CBT group: decreases were found in the a priori hypothesized regions of the right hemisphere in the inferior temporal gyrus, superior and inferior frontal gyrus, and increases were detected in the a priori hypothesized region, mostly in the left hemisphere: inferior frontal gyrus, middle temporal gyrus and insula. We did not detect changes in 18FDG uptake in the limbic region (hippocampus, parahippocampal gyrus and amygdala).

CONCLUSIONS: Changes in brain metabolism (18FDG uptake) after the treatment either with CBT or with antidepressants were similar in number of brain areas, with prominent right-left difference. This is in concordance with the asymmetry of brain activity noted in patients with PD according to previous PET (and SPECT) studies....

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Clinical Trial 2004; 25(4): 292-296 PubMed PMID: 15361820 Citation  Keywords:  Adult, Feedback, Physiological:physiology, Female, Humans, Hyperthyroidism:physiopathology, Hypothalamo-Hypophyseal System:physiology, Hypothyroidism:physiopathology, Male, Middle Aged, Reference Values, Regression Analysis, Severity of Illness Index, Thy.   

OBJECTIVE: To evaluate the hypothalamus-pituitary-thyroid (HPT) axis in patients with subclinical thyroid dysfunction recently reported to have either symptoms or organ involvements with potential morbidity, in order to better differentiate these patients with respect to controls.

PATIENTS: Sixtythree patients with subclinical hyperthyroidism (HyperT), 178 normal subjects (EuT) and 106 patients with subclinical hypothyroidism (HypoT) were enrolled; the groups presented normal thyroid hormone (FT4, FT3) levels and, respectively, reduced (HyperT), normal (EuT) and increased (HypoT) TSH levels. The negative feedback was simultaneously evaluated by multiple linear regression.

RESULTS: The mean TSH, FT4 and FT3 levels were significantly different in the three groups. The negative correlation between thyroid hormones (FT4 and FT3) and TSH secretion was significant (p<0.001 in HyperT; p<0.01 in EuT; p<0.000001 in HypoT group). FT4 mostly contributed to the negative correlation with TSH. The normal ranges of TSH values was accurately defined on the basis of the regression equation in the EuT group, due to the combining influence of both thyroid hormones (FT3 and FT4). No patient of the HyperT or HypoT group fell inside the range of estimated values of the normal group.

CONCLUSIONS: The HPT axis in patients with subclinical hyper- and hypo-thyroidism is significantly modified with respect to normal subjects. The status of the axis, as evaluated by the relationship between the three hormones (FT4, FT3, TSH) together considered, is characteristic of the normal or pathologic condition. A reliable method based on the regression analysis is proposed to correctly evaluate the status of the HPT axis....

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Journal Article 2004; 25(4): 273-277 PubMed PMID: 15361816 Citation  Keywords:  Animals, Biological Factors:physiology, Cattle, Cell Separation, Cells, Cultured, Culture Media, Conditioned, Growth Hormone:secretion, Male, Pituitary Gland, Anterior:cytology, Rats, Rats, Sprague-Dawley,.   

UNLABELLED: The pituitary pars tuberalis (PT) is characterized by PT-specific secretory cells which have raised the possibility of an endocrine function for this portion of adenohypophysis.

OBJECTIVE: To investigate the effect of the secretion of bovine PT cells into culture medium on growth hormone (GH) response of dispersed pars distalis (PD) cells of rats.

METHODS AND RESULTS: 48-hour culture medium of all PT cells at 1 microg of protein concentration induced the greatest GH release from PD cells. After PT cells separation on a discontinuos Percoll gradient and culturing, only the culture medium of cells from 50 and 60% Percoll strength released GH from PD cells. Therefore, cells from 50 and 60% strenght Percoll were cultured together. Only 0.2 mg protein of this culture medium was required to induce the maximal GH release from PD cells, suggesting that these cells could be responsible for producing the factor(s) which affect PD somatotrophe cells. After protein separation by 12% SDS-PAGE of this PT culture medium bands were eluted. The biological activity, measured as ng/ml of GH from PD cells, corresponded to a protein(s) of molecular weight between 45 and 66 kDal.

CONCLUSIONS: The results indicate that there is an active proteic factor(s) secreted by the PT that acts upon PD cells to stimulate GH release and that PD could be an effector organ for some secretory product(s) of the PT....

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Comparative Study 2004; 25(1-2): 102-108 PubMed PMID: 15159692 Citation  Keywords:  Adaptation, Physiological, Animals, Circadian Rhythm:radiation effects, Darkness, Light, Male, Photoperiod, Photoreceptor Cells:radiation effects, Pineal Gland:radiation effects, Rats, Rats, Wistar,.   

OBJECTIVE: This study was aimed to examine the pineal gland of rats exposed to constant light and darkness at light and electron microscopic level.

DESIGN: For this purpose 18 male Wistar rats were used. Animals were divided into three groups. Rats in group I (Control) were kept under 12 hrs light: 12 hrs dark conditions. Rats in group II were exposed to constant darkness, while rats in group III were exposed to constant light for 6 weeks. At the end of the experiment, all animals were killed by decapitation. The pineal glands of rats were removed, then processed for light and electron microscopy.

RESULTS: In our study, extensive number of pinealocytes was observed in the structure of pineal gland of rats exposed to constant darkness and some of the observed pinealocytes were determined to contain double nucleoli. Furthermore, mitochondria and lipid droplets in the cytoplasm of pinealocytes were increased and rough endoplasmic reticulum sacs were enlarged in this group. Whereas, in rats those exposed to the constant light, a decrease in pinealocyte intensity was associated with increase in the connective tissue between parenchymal cells. Additionally, mitochondria and lipid droplets in the cytoplasm of cells were decreased.

CONCLUSIONS: It was observed that the pinealocyte cell activity of rats exposed to constant darkness was increased but decreased in rats exposed to constant light....

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Clinical Trial 2004; 25(1-2): 75-77 PubMed PMID: 15159687 Citation  Keywords:  Adaptation, Physiological, Adolescent, Adult, Altitude, Atmospheric Pressure, Fasting:blood, Humans, Jordan, Luteinizing Hormone:blood, Male, Reference Values, Religion, Testosterone:blood,.   

OBJECTIVES: To study a possible effect of Ramadan fasting on luteinizing hormone and testosterone in people of the Jordan Valley.

METHODS: A comparative study (n=40) of serum levels of luteinizing hormone (LH) and testosterone (T) between people living in the Jordan Valley (JV), n=20, 360 meters below sea level, and those living in Ramtha City (RC), n=20, 600 meters above sea level, was conducted in December, 1998. A similar study (n=40) was also done during January 1999 in fasting people during the month of Ramadan.

RESULTS: Serum levels of LH in non-fasting people of the JV were statistically similar to those in people of RC. There was also no difference in serum levels of T between non-fasting people of the JV and those in RC. Serum levels of LH in fasting people of the JV were statistically indifferent from those fasting in RC. Serum T levels in fasting people of the JV, on the other hand, were higher than those in fasting people of RC (76+/-18.3 ng/ml compared to 62.7+/-24.2 ng/ml).

CONCLUSIONS: It is probably the environmental factors such as the higher barometric pressure of the JV compared to that at above sea level that play a role in higher serum levels of T in people of the JV. Other factors, such as genetic background and/or the cultural and nutritional characteristics of the people of the JV, may also contribute to this difference in serum T levels....

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Journal Article 2004; 25(1-2): 57-61 PubMed PMID: 15159684 Citation  Keywords:  Animals, Bivalvia, Enzyme Inhibitors:pharmacology, Feedback, Physiological:physiology, Ganglia, Invertebrate:cytology, Interleukin-1:physiology, Leukocytes:drug effects, Lymphocyte Activation:physiology, NG-Nitroarginine Methyl Ester:pharmacology, Neuroim.   

: Pedal ganglia excised and maintained in culture for up to 2 h, release NO at low levels. The range can vary between 0 to 1.1 nM. Non-stimulated immunocytes do not significantly stimulate ganglionic NO release when incubated with pedal ganglia. However, ganglia exposed to immunocytes that had been previously activated by a 30 min incubation with interleukin 1 beta, release NO significantly above basal levels. In these experiments, 91 +/- 2.5% of the non-stimulated immunocytes exhibited form factors in the 0.72 to 0.89 range (sampled prior to ganglionic addition), whereas 62 +/- 10.3% of the interleukin 1 beta stimulated immunocytes had form factors in the 0.39 to 0.49 range, demonstrating activation. Addition of the nitric oxide synthase inhibitor, L-NAME (10(-4) M), inhibited basal ganglionic NO release as well as that initiated by exposing the ganglia to activated immunocytes. Interestingly, non activated immunocytes, following ganglionic exposure, exhibited activity levels in the 13% range, representing a non significant increase. Cells exposed to interleukin 1 beta had a 65% activity level at the beginning of the experiment, followed by a drop of activity to 19 +/- 3.2% after ganglionic exposure. Repeating this last observation in the presence of L-NAME (10(-4) M), brought the activity level of the immunocytes back to the pre-ganglionic exposure level of activity, demonstrating that ganglionic NO was involved in down regulating immunocyte activity....

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Journal Article 2004; 25(1-2): 14-23 PubMed PMID: 15159677 Citation  Keywords:  Animals, Cannabinoid Receptor Modulators:physiology, Cannabinoids:pharmacology, Cardiovascular Physiological Phenomena:drug effects, Cardiovascular System:drug effects, Central Nervous System:drug effects, Dronabinol:pharmacology, Humans, Psychotropic Dru.   

: Dronabinol (Delta 9-tetrahydocannabinol, THC), the main source of the pharmacological effects caused by the use of cannabis, is an agonist to both the CB1 and the CB2 subtype of cannabinoid receptors. It is available on prescription in several countries. The non-psychotropic cannabidiol (CBD), some analogues of natural cannabinoids and their metabolites, antagonists at the cannabinoid receptors and modulators of the endogenous cannabinoid system are also promising candidates for clinical research and therapeutic uses. Cannabinoid receptors are distributed in the central nervous system and many peripheral tissues including spleen, leukocytes; reproductive, urinary and gastrointestinal tracts; endocrine glands, arteries and heart. Five endogenous cannabinoids have been detected so far, of whom anandamide and 2-arachidonylglycerol are best characterized. There is evidence that besides the two cannabinoid receptor subtypes cloned so far additional cannabinoid receptor subtypes and vanilloid receptors are involved in the complex physiological functions of the cannabinoid system that include motor coordination, memory procession, control of appetite, pain modulation and neuroprotection. Strategies to modulate their activity include inhibition of re-uptake into cells and inhibition of their degradation to increase concentration and duration of action. Properties of cannabinoids that might be of therapeutic use include analgesia, muscle relaxation, immunosuppression, anti-inflammation, anti-allergic effects, sedation, improvement of mood, stimulation of appetite, anti-emesis, lowering of intraocular pressure, bronchodilation, neuroprotection and antineoplastic effects....

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