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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.r />r /> 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.r />r /> 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.r />r /> 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.r />r /> 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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Journal Article 2004; 25(6): 403-406 PubMed PMID: 15665799 Citation  Keywords:  Adrenergic alpha-Antagonists:pharmacology, Adrenergic beta-Antagonists:pharmacology, Animals, Diabetes Mellitus, Experimental:drug therapy, Dose-Response Relationship, Drug, Insulin:blood, Islets of Langerhans:drug effects, Male, Oligopeptides:pharmacolog.   

OBJECTIVE: To examine the effect of ipamorelin (IPA), a novel pentapeptide with a strong growth hormone releasing potency, on insulin secretion from pancreatic tissue fragments of normal and diabetic rats.r />r /> MATERIALS AND METHODS: Diabetes mellitus was induced by streptozotocin (60 mg kg(-1)). Four weeks after the induction of diabetes, pancreatic tissue fragments of normal and diabetic rats were removed and incubated with different concentrations (10(-12) - 10(-6) M) of IPA. Insulin release from the pancreas was measured by radioimmunoassay.r />r /> RESULTS: Ipamorelin evoked significant (p<0.04) increases in insulin secretion from the pancreas of normal and diabetic rats. Either diltiazem or yohimbine or propranolol or a combination of atropine, propranolol and yohimbine inhibited IPA-evoked insulin secretion significantly (p<0.03) from the pancreas of normal and diabetic rats. Atropine caused a significant (p<0.007) reduction in the IPA-induced insulin secretion in diabetic but not in normal rats.r />r /> CONCLUSION: IPA stimulates insulin release through the calcium channel and the adrenergic receptor pathways. This is the first study to examine the effect of ipamorelin on insulin secretion in the pancreas....

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Clinical Trial 2004; 25(5): 391-396 PubMed PMID: 15580176 Citation  Keywords:  Adrenocorticotropic Hormone:blood, Adult, Aged, Anxiety:etiology, Caregivers:psychology, Cell Count, Disabled Persons:rehabilitation, Endocrine System:physiology, Female, Humans, Hydrocortisone:blood, Influenza, Human:immunology, Lymphocytes:immunology, M.   

OBJECTIVES: The purpose of this study was to determine whether psychological well being as well as metabolic, neuroendocrine and immune functions were different in non spousal primary caregivers of disabled elderly than in controls.r />r /> SETTING AND DESIGN: We randomly recruited 38 primary family carers of over 65 year old recipients of health home care services and 37 controls stratified according to sex and age.r />r /> METHOD: Data were collected on psychological wellbeing (including anxiety, depression and self-perceived quality of life), on neuroendocrine and immune conditions (haemanalysis and metabolic signs, plasma ACTH, cortisol, prolactin, intra-lymphocyte content of beta-endorphins, NK cell activity and number), as well as on the incidence and severity of influenza disease during previous winter.r />r /> RESULTS: Caregivers showed greater anxiety, although mean scores did not reach pathological levels. Neither depression nor satisfaction on quality of life did differ significantly, nor differences in haemanalisis and metabolic signs were found, apart from leukocyte and lymphocyte number, which was significantly lower in carers. Plasma levels of ACTH, cortisol and prolactin, the intra-lymphocyte content of beta-endorphins as well as the NK cell number and cytotoxicity did not show significant differences. Incidence and severity of influenza episodes was also similar, whereas the duration of influenza disease showed to be significantly longer.r />r /> CONCLUSIONS: Non spousal caregivers of disabled elderly suffer from only slight alterations of psychological, endocrine and immune parameters, and do not respond very differently to influenza disease. This does not support therefore any generic privilege for them in the allocation of public support or respite services....

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Clinical Trial 2004; 25(5): 386-390 PubMed PMID: 15580175 Citation  Keywords:  Adult, Carbon Dioxide, Female, Humans, Hydrocortisone:metabolism, Hypothalamo-Hypophyseal System:physiopathology, Male, Panic Disorder:chemically induced, Pituitary-Adrenal System:physiopathology, Reference Values, Saliva:metabolism, Sex Factors,.   

OBJECTIVES: The underlying mechanisms of panic attacks (PA's) are still unclear. Theories focusing on these mechanisms differ in their description of the relationship between panic and fear. The main controversy concerns whether a PA resembles the classical flight response, or whether it is qualitatively different from fear. According to the first theory, a PA would result in hypothalamic-pituitary-adrenal axis (HPA-axis) activation, whereas according to the second, it would not. So far, inconclusive results have been reported in studies measuring HPA-axis activity after laboratory evoked PA's. The present study was designed to assess cortisol levels following a 35% CO2 challenge in Panic Disorder (PD) patients compared to healthy volunteers as a measurement of HPA-axis activity.r />r /> DESIGN: Twenty-three PD patients and 20 healthy volunteers participated in the study. Cortisol was determined in saliva at regular intervals before and after the challenge. Furthermore, attention was paid to possible gender effects.r />r /> RESULTS: Although the 35% CO2 inhalation induced a significant increase in anxiety, no cortisol increase was found. Moreover, there was no difference between patient and control cortisol values following the 35% CO2 challenge, whereas the delta anxiety scores were far more pronounced in the patient group. Interestingly, male PD patients showed higher cortisol values.r />r /> CONCLUSIONS: This study may be in accordance with the view that PA's are not accompanied by an important HPA-axis activation. There are some indications for aberrant cortisol secretion in male PD patients. Further research needs to confirm whether male and female PD patients differ in their underlying mechanisms related to HPA-axis activity....

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Clinical Trial 2004; 25(5): 381-385 PubMed PMID: 15580174 Citation  Keywords:  Adult, Body Composition, Energy Metabolism:physiology, Exercise:physiology, Female, Humans, Leptin:blood, Obesity:blood, Physical Endurance:physiology, Physical Fitness:physiology,.   

OBJECTIVE: Recent studies have concluded that an energy expenditure by an acute exercise session has no immediate effect on leptin levels while some showed a decline in leptin levels. The purpose of this study was to investigate any possible effects of training status of the subjects on acute exercise-leptin relationship in obese patients.r />r /> MATERIALS AND METHODS: Fourteen obese sedentary females were enrolled to the study and effects of acute incremental exercise on serum leptin levels were determined at rest and at maximal exercise performance. Then, they participated to a 12-weeks endurance aerobic training programme performed in the laboratory on a computer controlled cycle ergometer and their leptin levels were re-evaluated and the leptin-acute exercise relationships obtained under different training levels in the same group of subjects were compared. The body compositions were determined by bioelectrical impedance. Pre and post training blood samples were taken at rest and at the maximal exercise performance. Serum leptin levels were analysed in duplicate by RIA. Data were evaluated using, paired t and Pearson's tests.r />r /> RESULTS: Leptin levels were not acutely affected by the incremental exercise either before (23.62+/-3.5 ng/ml and 22.62+/-3.6 ng/ml) or after (13.13+/-3.4 ng/ml and 13.82+/-3.6 ng/ml) endurance training. The marked decrease in leptin levels following training was closely correlated with fat mass loss R= 0.899 (P= 0.0001).r />r /> CONCLUSIONS: This study indicates that an increase in energy expenditure by acute exercise has no significant acute effect on leptin level regardless of the training status of the subjects and decrease in leptin levels after a 12-weeks endurance aerobic training programme are closely associated with the fat mass loss....

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Clinical Trial 2004; 25(5): 373-380 PubMed PMID: 15580173 Citation  Keywords:  Adolescent, Adult, Anti-Bacterial Agents:therapeutic use, Combined Modality Therapy, Female, Gestational Age, Humans, Obstetric Labor, Premature:therapy, Pregnancy, Pregnancy Outcome, Tocolysis, Treatment Outcome,.   

OBJECTIVE: The aim of this study was to determine: a) to what extent application of antibiotics enhances efficiency of tocolysis; b) whether the duration of antibiotic treatment influences its efficacy; c) what criterion is decisive for efficacy of tocolysis assisted by antibiotic therapy.r />r /> MATERIALS AND METHODS: 223 successive women with unifetal pregnancies, aged 17 to 42 (average age 27.3), admitted to the Department of Gynecology and Obstetrics of the JU Medical College in the period from January 1, 1999 to September 9, 2001, were enrolled in the study. Using clinical methods such as: assessment of contractile activity of the uterus, of uterine cervix and membranes, presence of bleeding and other clinical symptoms, these women were diagnosed with imminent preterm labour.r />r /> CONCLUSIONS: Antibiotic treatment enhances the efficacy of tocolysis, influencing the time of prolonging pregnancy in imminent preterm delivery. This synergistic effect is clinically crucial as in this way significantly larger number of children will be born at term and also a number of premature neonates who survive may be increased....

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Clinical Trial 2004; 25(5): 368-372 PubMed PMID: 15580172 Citation  Keywords:  Adult, Body Temperature Regulation:physiology, Circadian Rhythm:physiology, Humans, Hypothalamo-Hypophyseal System:physiology, Male, Melatonin:physiology, Middle Aged, Reference Values, Thermogenesis:physiology, Thyroid Gland:physiology, Thyrotropin:blood.   

OBJECTIVE: Melatonin plays a role in the regulation of biological rhythms, body temperature presents circadian variations with lower levels during nighttime, when melatonin levels are very high, and thyroid hormones influence shiver independent thermogenesis. We have investigated on possible interactions between the hypothalamic-pituitary-thyroid axis and melatonin in the control of body temperature in humans.r />r /> METHODS: Peripheral blood samples for thyrotropin-releasing hormone (TRH), thyroid-stimulating hormone (TSH), free-thyroxine (FT4), melatonin levels determination and body temperature measurements were obtained every four hours for 24-hours starting at 0600 h in a controlled temperature and light-dark environment from ten healthy males, aged 38-65 (mean age +/-s.e. 57.4+/-3.03, mean body mass index +/-s.e. 25.5+/-0.75). We calculated fractional variation and correlation on single time point hormone serum levels and tested whether the time-qualified data series showed consistent pattern of circadian variation.r />r /> RESULTS: A statistically significant difference was evidenced for the fractional variation of daytime TSH serum levels (0600 h-1000 h vs. 1000 h-1400 h, p=0.01, 1000 h-1400 h vs. 1400 h-1800 h, p=0.0001, 1400 h-1800 h vs. 1800 h-2200 h, p=0.001) and for the fractional variation of FT4 serum levels at 1800 h-2200 h vs. 2200 h-0200 h (p=0.02). FT4 serum levels correlated positively with TRH serum levels at 1000 h (r=0.67, P=0.03) and at 1400 h (r=0.63, p=0.04), negatively with TSH serum levels at 2200 h (r=-0.67, p=0.03), negatively with melatonin serum levels at 2200 h (r=-0.64, p=0.04) and at 0200 h (r=-0.73, p=0.01). TRH serum levels correlated positively with TSH serum levels at 0200 h (r=0.65, p=0.04) and at 0600 h (r=0.64, p=0.04). Body temperature correlated positively with FT4 serum levels at 1000 h (r=0.63, p=0.04) and negatively with melatonin serum levels at 0200 h (r=-0.64, p=0.04). A clear circadian rhythm was validated for body temperature (with acrophase in the morning) and melatonin, TRH and TSH secretion (with acrophase at night), while FT4 serum level changes presented ultradian periodicity (with acrophase in the morning).r />r /> CONCLUSION: Changes of TSH serum levels are smaller and those of FT4 are greater at night, when melatonin levels are higher, so that the response of anterior pituitary to hypothalamic TRH and of thyroid to hypophyseal TSH may be influenced by the pineal hormone that may modulate the hypothalamic-pituitary-thyroid axis function and influence the circadian rhythm of body temperature....

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Journal Article 2004; 25(5): 361-367 PubMed PMID: 15580171 Citation  Keywords:  Altitude, Animals, Body Weight:physiology, Cysteamine:pharmacology, Growth Hormone:genetics, Hypothalamus:drug effects, Hypoxia:metabolism, Male, Pituitary Gland:metabolism, RNA, Messenger:analysis, Rats, Rats, Sprague-Dawley, Somatostatin:drug effects,.   

OBJECTIVES: The aim of this study was to investigate the response of the growth hormone (GH) in rat anterior pituitary to intermittent hypoxia (IH) and its modulation by hypothalamic somatostatin (SS).r />r /> SETTING AND DESIGN: To observe the hypoxic response, rats were exposed to simulated altitude hypoxia (2 km or 5 km) in a hypobaric chamber for various days (4 h/d); to clarify SS-involvement, rats were pretreated with SS antagonist (cysteamine, CSH, 200 mg/kg/d, s.c.) then exposed to IH (5 km) for 2d. The GH mRNA and immunostaining GH in pituitary as well as immunostaining SS in median eminence (ME) of hypothalamus were assayed by RT-PCR and immuno-histochemistry, respectively.r />r /> RESULTS: IH of 5 km altitude (IH5) markedly suppressed the body weight gain (BWG) of rats from 1d to 10d, and it was returned to control level henceforth, while no significant influence was showed in the group of IH of 2 km altitude (IH2). IH5 for 2 and 5d significantly decreased GH mRNA expression in the pituitary. The pituitary immunostaining GH was remarkably increased in groups of IH2 for 5, 10, and 15 d, and in groups of IH5 for 2, 5, and 10d. Immunostaining SS in ME was significantly reduced in group of IH2 for 5d, and in groups of IH5 for 2d and 5d. Pretreatments (s.c.) with SS antagonist (CSH) significantly reversed IH5-caused increase of immunostaining GH and reduction of mRNA levels in pituitary.r />r /> CONCLUSIONS: IH may cause a short-term and recoverable suppression of GH release, and reduce GH mRNA expression in anterior pituitary, which may depend on the intensity and duration of the hypoxia. This suppression may be due to a modulation of hypoxia-activated SS....

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