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Comparative Study 2005; 26(6): 795-798 PubMed PMID: 16380688 Citation  Keywords:  Animals, Antioxidants:metabolism, Brain:enzymology, Glutathione:metabolism, Hyperthyroidism:metabolism, Lipid Peroxidation:physiology, Liver:enzymology, Male, Malondialdehyde:metabolism, Myocardium:enzymology, Pineal Gland:physiology, Rats, Rats, Sprague-.   

OBJECTIVE: Thyroid hormones regulate energy metabolism and act on the mitochondria, which is an important source of free radicals in the cell. Reactive oxygen types play a significant role in physiological mechanisms, but in excessive amounts they can cause oxidative damage in molecules. The aim of the present study was to determine levels of lipid peroxidation caused by induced hyperthyroidism in cerebral, hepatic and cardiac tissues of pinealectomized rats.

METHODS: Experimental animals used in the study were allocated to three groups as general control group, hyperthyroidism-sham pinealectomy group and hyperthyroidism-pinealectomy group. GSH and MDA levels in cerebral, hepatic and cardiac tissues were evaluated at the end of the 3-week study period.

RESULTS: It was found that MDA levels in cerebral, hepatic and cardiac tissues were the highest in hyperthyroidism and pinealectomy group and that these values were higher in hyperthyroidism-sham pinealectomy group than in the control group (p<0.001). It was seen that tissue GSH levels significantly increased in hyperthyroidism-sham pinealectomy group (p<0.001) and that the increase in hyperthyroidism and pinealectomy group was higher than the increase in the control group only (p<0.001).

CONCLUSION: Results of our study show that MDA and GSH levels in cerebral, hepatic and cardiac tissues increased due to hyperthyroidism and that the increase in MDA levels became more evident and GSH levels were significantly suppressed after pinealectomy....

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Comparative Study 2005; 26(6): 806-810 PubMed PMID: 16380687 Citation  Keywords:  Animals, Glutathione:metabolism, Hyperthyroidism:chemically induced, Kidney:metabolism, Lipid Peroxidation, Male, Malondialdehyde:metabolism, Melatonin:metabolism, Oxidative Stress:physiology, Rats, Rats, Sprague-Dawley, Testis:metabolism, Thyroxine,.   

OBJECTIVE: The present study aimed at determining how 3-week intraperitoneal melatonin administration affected oxidative stress caused by experimental hyperthyroidism.

MATERIALS AND METHODS: The study was conducted on 30 male rats of Sprague-Dawley species. The experimental animals were divided to 3 groups (control, hyperthyroidism and hyperthyroidism+melatonin). The supplementation was continued for 3 weeks after which the animals were sacrificed and tissue malondyaldehyde (MDA) and glutathione (GSH) levels were determined.

RESULTS: MDA levels in kidney and testis tissues in hyperthyroidism group were higher than those in control and hyperthyroidism+melatonin administered groups (p<0.001) and levels in hyperthyroidism+melatonin administered group were higher than those in the control group (p<0.001). The highest GSH levels were obtained in hyperthyroidism+melatonin-administered group (p<0.001) and GSH levels in hyperthyroidism group were higher than those in the control group (p<0.001).

CONCLUSION: Results of the study demonstrate that hyperthyroidism induced by 3-week L-thyroxine administration increased oxidative stress in kidney and testis tissues and that although melatonin administration inhibited this stress to a certain extent, it could not bring the stress down to the level in controls....

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Comparative Study 2005; 26(6): 729-732 PubMed PMID: 16380686 Citation  Keywords:  Age Factors, Animals, Animals, Newborn, Longitudinal Studies, Male, Organ Size:drug effects, Rats, Rats, Sprague-Dawley, Selective Estrogen Receptor Modulators:pharmacology, Sexual Behavior, Animal:drug effects, Tamoxifen:pharmacology, Testis:cytology, Te.   

OBJECTIVE: In this study we examined the possibility that demasculinization produced by the neonatal administration of tamoxifen is accompanied by a decline in plasma levels of testosterone during adulthood.

METHODS: Wistar male rats received either a treatment with 12.5 microg/kg of tamoxifen during the first eight days of age or a treatment with 100 microg/kg of tamoxifen for five days. Each treatment had their respective control group. During adulthood their masculine sexual behavior was analyzed. At 8 months of age, males were killed by decapitation, trunk blood was collected and peripheral glands were dissected and weighed. Testosterone levels were measured by HPLC. Histological analysis of peripheral glands was performed.

RESULTS: Both neonatal tamoxifen treatments significantly decreased male sexual behavior when compared to control values. In addition, both treatments also showed a significant decrease in testicular weight when compared to control groups, as well as a decrease in seminal vesicle weight. In the microscopic analysis, a significant decrease in the diameter of the seminiferous tubules was observed, especially in the animals treated with 100 microg/kg of tamoxifen. However, no differences were observed between tamoxifen treated and control animals concerning plasma levels of testosterone.

CONCLUSION: The present results indicate that behavioral manifestations and changes in peripheral reproductive organs that accompanied demasculinization are not due to a deficit in testosterone secretion....

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Clinical Trial 2005; 26(6): 696-698 PubMed PMID: 16380679 Citation  Keywords:  Aged, Alzheimer Disease:blood, Amyloid beta-Peptides:cerebrospinal fluid, Biomarkers:blood, Female, Humans, Male, Multivariate Analysis, Peptide Fragments:cerebrospinal fluid, beta Carotene:blood, tau Proteins:cerebrospinal fluid,.   

: We studied the plasma beta carotene concentrations in 40 Alzheimer's disease patients and the association with cerebrospinal fluid beta-amyloid 1-40, (Abeta40), cerebrospinal fluid beta-amyloid 1-42 (Abeta42) and cerebrospinal fluid total Tau. We found that patients with plasma beta carotene levels below the 25th percentile had 55% reduced ratios of Abeta40/Tau and 51% reduced ratios of Abeta 40/Abeta 42 compared with patients in the highest quartile. Mean Tau concentrations in the lowest quartile of plasma beta-carotene levels were 74% higher compared with the highest quartile of plasma beta-carotene levels. Thus, we could demonstrate an statistically significant association between beta carotene levels in plasma and neurochemical markers in the cerebrospinal fluid of Alzheimer's disease patients....

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Comparative Study 2005; 26(6): 704-708 PubMed PMID: 16380675 Citation  Keywords:  Analysis of Variance, Animals, Antioxidants:pharmacology, Antithyroid Agents:pharmacology, Brain:metabolism, Hydrocarbons:metabolism, Lipid Peroxidation:physiology, Male, Malondialdehyde:metabolism, Melatonin:metabolism, Neuroprotective Agents:metabolism,.   

OBJECTIVE: It is known that thyrotoxicosis induces lipid peroxidation (LPO). In contrast, propylthiouracil (PTU), a thyrostatic drug is a well-known antioxidant. Also melatonin has been shown to protect against free radical-induced neuronal destruction. At the same time, it is generally accepted that the brain is the most vulnerable tissue to oxidative stress.

METHODS: The goal of the study was to examine the components of LPO, i.e., conjugated dienes (CD), malondialdehyde (MDA) and Schiff's bases (SB), in the brain of male Wistar rats. Two experiments were performed, with two control groups created for each experiment: Group 1--intact animals and Group 2--animals injected with 0.9% NaCl. In Experiment I, the animals received L-thyroxine (L-T4) in a dose of 100 microg/kg BW, i.p., daily, for two weeks (Groups 3-5). After one week of L-T4 treatment, the following agents were added during a subsequent week: Group 4--PTU in drinking water (45 mg/kg BW/day); Group 5--melatonin (5 mg/kg BW, daily). In Experiment II, lasting 7 days, the animals were divided into the following groups: Group 1--intact animals; Group 2--animals injected with 0.9% NaCl; Group 3--PTU in drinking water (45 mg/kg BW/day); Group 4--melatonin (5 mg/kg BW, daily).

RESULTS: In Experiment I, we observed a significantly higher SB level in saline treated animals and a significant increase in both CD and SB levels in rats treated with L-T4, compared to those in non treated control. CD levels were also elevated in rats treated with L-T4, compared to values in the saline only treated animals. Melatonin and PTU reduced CD levels and melatonin diminished SB levels, as compared to those in L-T4-treated rats. In Experiment II, we observed significantly higher CD, SB and MDA levels in saline treated rats, when compared to respective values in non treated control. Melatonin decreased CD levels, when compared to CD levels in both the non treated and saline injected controls. Additionally, melatonin reduced SB levels relative to change in the brains of saline treated rats. Furthermore, PTU decreased CD levels in brain homogenates compared to non-treated animals.

CONCLUSIONS: (1) L-thyroxine administration stimulates LPO in the rat brain; (2) All the examined antioxidants decrease LPO in L-T4-administered animals; (3) All the examined antioxidants reduce the basal LPO; 4) Stress, when induced by handling, intensifies oxidative processes in the organism....

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Comparative Study 2005; 26(6): 739-744 PubMed PMID: 16380673 Citation  Keywords:  Analysis of Variance, Animals, Arthritis, Experimental:chemically induced, Arthritis, Rheumatoid:enzymology, Chemokine CCL5:genetics, Collagen, Cytokines:genetics, Disease Models, Animal, Down-Regulation, Female, Interleukin-1:genetics, Interleukin-6:gene.   

OBJECTIVE: To observe the effects and mechanisms of beta-endorphin (beta-END) preventing collagen induced arthritis (CIA) by neuroimmuno-regulating pathway.

METHODS: Female wistar (Ws) rats were used in this study. CIA was induced by Native bovine type II collagen emulsified with complete Freund's adjuvant (CFA). Beta-END was administered i.p. to CIA rats every other day from the 14th day (secondary immunization) to the 35th day after primary immunization. Clinical assessments were performed by two independent, blinded examiners every other day. Pathological and radiological observations were taken on the 35th day after the primary immunization. Tumor necrosis factor-alpha (TNF-alpha), interleukin-1beta (IL-1beta), interleukin-6 (IL-6), regulated upon activation, normal T-cell expressed and secreted (RANTES), inducible NO syntheses (iNOS), matrix metalloproteinase-2 (MMP-2) and MMP-9 mRNA expression of synovium tissues of CIA rats was estimated by quantitative RT-PCR. The frequency of spleen Th1 and Th2 cells were assessed by fluorescence activated cell sorter (FACS) assay.

RESULTS: Clinical manifestation of rats with CIA were significantly abrogated or ameliorated by treatment with beta-END. Beta-END treatment in vivo could down-regulate mRNA expression of several pro-inflammatory cytokines, chemokines and MMPs in CIA synovial, and polarize Th1/Th2 balance to Th2.

CONCLUSION: Beta-END alleviates CIA through both depressing Th1 responses and down-regulating proinflammatory and other rheumatic factors, suggesting beta-END is a promising anti-inflammatory and anti-rheumatic agent in treating CIA....

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Case Reports 2005; 26(6): 757-758 PubMed PMID: 16380671 Citation  Keywords:  Aged, Atrophy, Diagnosis, Differential, Empty Sella Syndrome:complications, Fatigue:diagnosis, Female, Hormones:therapeutic use, Humans, Hydrocortisone:therapeutic use, Hypopituitarism:complications, Inflammation:complications, Magnetic Resonance Imaging,.   

: A 75-year-old woman complained about progressing fatigue. She appeared somnolent, but fully oriented and in no acute distress. Her face was pale and puffy. She did not show any signs of focal neurological disease, and the remainder of the physical examination was unrevealing. Routine laboratory tests were unremarkable except for hyponatremia and mildly decreased levels of free T3 and free T4, with TSH in the normal range. Pituitary function tests demonstrated secondary adrenal insufficiency and hypothyroidism. Magnetic resonance imaging (MRI) unmasked hypophysitis with the characteristic findings of homogeneous gadolinium uptake of the pituitary and a prominent pituitary stalk ('dural tail sign', arrows in Fig. 1 A and B, sagittal and coronal views). Substitution of hydrocortisone and levothyroxine resulted in rapid and sustained improvement of all symptoms and normalisation of laboratory findings. MRI abnormalities normalized within the following six months. At follow-up three years later, MRI signs had further regressed and demonstrated an empty sella (Fig. 2 A and B)....

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Clinical Trial 2005; 26(5): 447-452 PubMed PMID: 16264418 Citation  Keywords:  Adolescent, Aging:physiology, Body Height:drug effects, Child, Female, Growth Hormone:therapeutic use, Hormones:blood, Human Growth Hormone:deficiency, Humans, Magnetic Resonance Imaging, Male, Pituitary Gland:anatomy & histology, Predictive Value of Test.   

INTRODUCTION: Certain relationships between pituitary size and growth hormone (GH) secretion have previously been observed, however they are still a matter of controversy. Organic abnormalities of the hypothalamic-hypophyseal region are important for predicting growth response to GH therapy.

AIM: Evaluation of relations between GH secretion and the pituitary size in short children and estimation of the efficacy of GH therapy in children with GH deficiency (GHD).

PATIENTS AND METHODS: The analysis comprised 216 short children (159 boys). Two GH stimulation tests, as well as magnetic resonance image (MRI) examination, were performed in each patient. All the patients with GHD were treated with GH for, at least, one year.

RESULTS: Significant correlations were found between pituitary height and GH secretion (p < 0.05). Patients were classified into three (3) groups: 1) pituitary hypoplasia (HP) for height age; 2) HP for the chronological age but not for the height age; 3) normal pituitary size. Significant differences in GH secretion were observed among the groups (6.1+/-5.3 vs. 8.1+/-4.4 vs. 12.3+/-9.1 ng/mL, respectively). There was a negative correlation between GH peak and height gain during GH therapy (r = -0.34). The highest growth improvement was noticed in patients with HP for the height age.

CONCLUSIONS: Pituitary hypoplasia for the height age is related to more severe GH deficiency and the best response to GH therapy....

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