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Journal Article 2008; 29(5): 712-716 PubMed PMID: 18987613 Citation  Keywords:  Carcinogens:chemistry, Chromatography, High Pressure Liquid, Chromatography, Thin Layer, Electrons, Horseradish Peroxidase:chemistry, Hydrogen Peroxide:chemistry, Magnetic Resonance Spectroscopy, Mass Spectrometry, Naphthols:chemistry, Oxidation-Reduction.   

OBJECTIVES: The aim of the study was to examine oxidation of carcinogenic Sudan I by peroxidase and characterize the structure of its two major peroxidasemediated metabolites. Another target of the study was to evaluate a mechanism of this oxidation.

METHODS: Thin layer chromatography (TLC) and high performance liquid chromatography (HPLC) with ultraviolet (UV) and visible (VIS) detection was employed for the separation of Sudan I metabolites formed by peroxidase. UV/ VIS-, and mass- spectroscopy as well as nuclear magnetic resonance (NMR) were used to characterize structures of two major Sudan I metabolites.

RESULTS: Peroxidase oxidizes Sudan I by a one electron oxidation to eight products. Two major Sudan I metabolites were isolated by TLC on silica gel and HPLC and structurally characterized. The major product formed during the Sudan I oxidation by peroxidase is Sudan I metabolite M2, which corresponds to a Sudan I dimer molecule. The second major metabolite (M1) is the product of secondary, enzyme independent reactions, being formed from the Sudan I dimer that lost the benzenediazonium moiety.

CONCLUSIONS: The data are the first report on structural characterization of Sudan I metabolites formed by its oxidation with peroxidase....

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Letter 2007; 28(3): 247-249 PubMed PMID: 17627255 Citation  Keywords:  Humans, Microscopy, Electron, Purkinje Cells:ultrastructure,.   

: Conventional electron microscopy of human cerebellar cortex has revealed two types of Purkinje neurons with different staining intensities. The light-stained type constitute the major type and both types have similar diameters. This finding was not reported in human before but in lower mammalian. Whether the different staining pattern of Purkinje neurons implies a specific histo-functional aspect a pathological one or histological artifacts is not known....

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Journal Article 2006; 27(Suppl 1): 61-68 PubMed PMID: 16892010 Citation  Keywords:  Adult, Aged, Chronic Disease, Corrosion, Dental Alloys:adverse effects, Electron Probe Microanalysis, Female, Gingiva:drug effects, Humans, Hypersensitivity:etiology, Lymphocyte Activation, Male, Metals:adverse effects, Middle Aged, Mouth Mucosa:drug effe.   

OBJECTIVE: Corrosion products of different metallic alloys used in prosthetic dentistry often cause the development of a bluish-grey pigmentation of gingiva and oral mucosa. The aim of this study was to determine the content of metals in metallic pigmentations and evaluate the immune response to metals found in the oral cavity.

MATERIAL AND METHODS: The local tissue reactions were investigated clinically by electron microscopy and by energy dispersive x-ray microanalysis. An extensive anamnesis of the patients was recorded as well as earlier contacts with health care institutions. The immunological response to metallic components of dental alloys was evaluated in 34 patients by MELISA, a modified test for lymphocyte proliferation. In addition, cytokines in culture media were determined in 10 persons by the Human Inflammation Antibody Array.

RESULTS: Dense particles containing metals were found in the matrix among collagen fibrils and in close proximity of the lamina basalis of the gingival epithelium. Particles were also localized intracellularly in fibroblasts, macrophages, and endothelial cells. Metallic depositions consisted predominantly of silver accompanied by selenium and sulphur. Twenty five out of 34 patients revealed high lymphocyte reactivity (positive MELISA test) to one or more metal components of dental restorations. A correlation between the positivity in MELISA test and number of dental alloys in the oral cavity was also found. Twenty MELISA positive patients suffered from serious health problems (various allergies, autoimmune diseases, Parkinson's syndrome etc.). Nickel and inorganic mercury were the most common sensitizers in vitro. The cytokine assay revealed that mercury chloride activated predominantly TH2 lymphocytes, while nickel chloride activated mainly TH1 lymphocytes.

CONCLUSIONS: Metallic pigmentations in the oral cavity demonstrate a corrosion process and may pose a risk in immunologically susceptible patients....

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Case Reports 2006; 27(1-2): 93-96 PubMed PMID: 16648809 Citation  Keywords:  Adenoma:metabolism, Adrenocorticotropic Hormone:blood, Cell Proliferation, Human Growth Hormone:blood, Humans, Hydrocortisone:blood, Immunohistochemistry, Insulin-Like Growth Factor I:metabolism, Male, Microscopy, Electron, Middle Aged, Pituitary Hormones.   

: Herein, we report the case of a 46-year-old male patient with only one month of double vision. Radiological examination revealed a pituitary tumor. Endocrinological investigations showed no pathological alterations of anterior pituitary function. Neuropathological examinations revealed a pituitary gland adenoma with an elevated proliferation rate (MIB-1 index 4-5 %) as well as an elevated p53 expression leading to the diagnosis of an atypical pituitary adenoma. Interestingly, the tumor exhibited strong basophilia in routine histology and densely secretory granules in electron microscopy (EM). However, no hormone excess was detectable in immunohistochemistry. In contrast to clinical and immunohistochemical observations, EM and routine histology findings implied a hormone production. This discrepancy might be due to a production of unfunctional pre-stages of pituitary gland proteins in this fast growing neoplasm....

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Comparative Study 2005; 26(6): 719-723 PubMed PMID: 16380689 Citation  Keywords:  Adaptation, Physiological, Adrenal Glands:enzymology, Animals, Electron Transport Complex IV:biosynthesis, Enzyme Induction:drug effects, Hypothalamo-Hypophyseal System:physiopathology, Liver Circulation:drug effects, Liver Cirrhosis, Experimental:chemica.   

OBJECTIVES: Cytochrome oxidase activity has been determined in the adrenal glands of thioacetamide (TAA)-cirrhotic rats.

MATERIAL AND METHODS: Two groups of animals (Control group; n=10 and TAA group; n=11) of three months evolution were used to study the cytochrome oxidase activity in the suprarenal cortex (glomerular, fascicular and reticular layers) and medulla. TAA was administered orally and cytochrome oxidase (COX) activity was assayed by an immunohistochemical technique.

RESULTS: In TAA-cirrhotic rats, COX activity increases in the cortex fascicular layer (221 +/- 1.79 vs 181.9 +/- 2.75; p<0.001) as well as in the medulla (146.6 +/- 1.72 vs 129 +/- 3.09; p<0.001).

CONCLUSION: These results make it possible to consider the existence of hypothalamic-pituitary-adrenal-axis and adrenomedullary sympathetic system hyperactivity, both peripheral limbs of the stress system, in this experimental model of cirrhosis....

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Journal Article 2005; 26(5): 575-580 PubMed PMID: 16264398 Citation  Keywords:  Acetylserotonin O-Methyltransferase:metabolism, Animals, Arylalkylamine N-Acetyltransferase:metabolism, Female, Melatonin:blood, Microscopy, Electron, Pineal Gland:metabolism, Pregnancy, Pregnancy, Animal:metabolism, Rabbits, Radioimmunoassay,.   

OBJECTIVES: The morphological and biochemical aspects of the pineal gland of pregnant and non-pregnant female vizcachas were investigated to examine whether there is a relationship between the pregnancy and this gland.

METHODS: Pregnant and non-pregnant adult female vizcachas were used. The ultrastructure of type I cell (dark and light pinealocytes) was studied. Pineal and serum melatonin were investigated by radioimmunoassay. Radiometric methods were applied to investigate the arylalkylamine-N-acetyltransferase (AA-NAT) and hydroxyindole-O-methyltransferase (HIOMT) activities.

RESULTS: The morphological study showed the existence of dark and light pinealocytes. The differences between both cells are slight. However, the appearance of dark pinealocytes suggests that they have a high activity. These cells were more abundant in the pineal gland of pregnant females. The pineal melatonin levels and the AA-NAT activity were higher in the pregnant females. Serum melatonin and HIOMT activity did not show significant differences.

CONCLUSION: Our results suggest that the morphological and biochemical changes in the pineal gland of pregnant vizcachas are associated with the gestation. However, the relation between the pineal gland and the pregnancy is complex and further studies are necessaries to clearly establish it....

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Journal Article 2003; 24(3-4): 215-223 PubMed PMID: 14523360 Citation  Keywords:  Aging:metabolism, Animals, Autoradiography, Cell Division:drug effects, DNA:biosynthesis, Male, Melatonin:pharmacology, Microscopy, Electron, Rats, Rats, Sprague-Dawley, Spleen:cytology, T-Lymphocytes:drug effects, Thymus Gland:drug effects,.   

OBJECTIVES: In this study we investigated the effect of melatonin treatment on the proliferative activity, the rate of DNA synthesis and the histopathological changes of splenic and thymic lymphocytes in old rats.

METHODS: Two subgroups of old rats (25-months-old) were used in this study. One subgroup was given melatonin in the drinking water (250-300 mg/day/rat) for 3 months while the second subgroup was given water containing diluent. A third group consisted of young rats (3-months-old) which served as an additional control.

RESULTS: A (3)H-thymidine autoradiographic investigation showed a reduction in both the proliferative activity and the rate of DNA synthesis in splenic and thymic lymphocytes in old rats. In addition, light and electron microscopy showed severe histopathological changes in these cells from diluent-treated old rats. Melatonin administration increased the proliferative activity and the rate of DNA synthesis in the lymphocytes of both the spleen and thymus of the old animals. Also, histopathological changes were partially reversed by melatonin treatment with the tissues appearing similar to those in the young rats.

CONCLUSION: The stimulation of the lymphocyte activity by melatonin is a beneficial response, especially in old rats, since aging results in an inhibition in lymphocytic functions....

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Journal Article 2002; 23(5-6): 405-410 PubMed PMID: 12500161 Citation  Keywords:  Animals, Endoplasmic Reticulum, Rough:ultrastructure, Estradiol:analogs & derivatives, Female, Hormone Replacement Therapy, Microscopy, Electron, Mitochondria:drug effects, Ovariectomy, Pineal Gland:drug effects, Rats, Rats, Wistar, Ribosomes:drug effects.   

OBJECTIVE: The aim of this study was to examine the effects of ovariectomy and ovariectomy followed by estradiol benzoate administration on the ultrastructure of pinealocytes in female rat.

DESIGN: For this purpose 15 female Wistar rats were used. Animals were divided into three groups. Group I and II were designated as sham-ovariectomized (control) and ovariectomized, respectively. Group III was ovariectomized and daily injected with estradiol benzoate for one month. At the end of the experiment, all animals were anesthetized with ketamine for fixation by vascular perfusion. Pineal glands of groups I, II and III were removed. All specimens were examined by electron microscopy.

RESULTS: Ovariectomy caused an increase of lipid droplets, mitochondria and ribosomes. Rough endoplasmic reticulum was extensive in the cytoplasm. Estradiol administration to ovariectomized rats resulted in formation of less extensive lipid droplets, mitochondria and ribosomes compared to pinealocyte ultrastructure of both control and ovariectomized rats. Extensiveness of rough endoplasmic reticulum in the pinealocytes of estradiol-administrated rats was similar to that in controls.

CONCLUSIONS: The results confirm relationship between the pineal gland and gonads in the rat and it has been suggested that estradiol benzoate reverses the ultrastructural changes, which indicate increased cell activation, occurring in the pinealocytes after ovariectomy....

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