ACTA ENDOCRINOLOGICA (BUC)

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Context. Interventions that suppress hepatic gluconeogenesis from amino acids may be useful for improving glycemic control in diabetic patients. Objectives. It was shown that administration of glucocorticoid receptor antagonist Mifepristone (MIF) leads to variously pronounced changes in the alanine-, aspartate-, tyrosine- aminotransferases (ALT, AST, TAT) activity in the liver of experimental animals. It has been suggested that this selective effect of MIF may be related to differences in the expression of the corresponding genes. The aim of the study was to investigate the gene expression and activity of ALT, AST and TAT in the liver of rats with streptozotocin-related diabetes (StD) under the long-term oral MIF administration. Methods. Male Wistar rats (n=48) with StD under the 10-days oral MIF administration were used. It was measured the activity of ALT, AST, TAT enzymes and relative expression of this genes in the liver of experimental animals. Results. In rats with StD the gene expression of all three studied aminotransferases in the liver was statistically significantly increased and their activity was increased as well. MIF administration did not change the studied genes expression and enzymes activity to healthy rats and caused a decrease in expression of ALT and AST genes and activity of these enzymes to rats with StD. However, the expression of the TAT gene and the activity of this enzyme in the liver of rats with StD increased upon MIF administration in comparison with animals with StD. Conclusions. The introduction of MIF against the background of StD reduces the expression of genes and the activity of ALT and AST in the liver, what determine the transamination of amino acids to include them in gluconeogenesis, but increases the expression of genes and the activity of TAT, what determine the inclusion of tyrosine in the biogenic amines synthesis. The mechanisms of such selectivity require further study.

Background. Resistin, as an adipokine, has been shown to be increased in serum plasma of gastric cancer patients and suggested to be a major factor in gastric carcinogenesis. However, it is still not clear how Resistin influences gastric cancer progression. The aim of this study was to evaluate Resistin effect on cell proliferation and expression of telomerase gene in gastric cancer cell line (AGS). Methods. In this study, the proliferating activity of AGS cells stimulated with Resistin was also evaluated by using 2,3-Bis-(2-Methoxy-4-Nitro-5-Sulfophenyl)-2HTetrazolium- 5-Carboxanilide (XTT) assay and trypan blue staining method. To investigate telomerase gene expression affected by Resistin, total RNA was extracted, cDNA was synthesized and expression of hTERT mRNA was carried out by real-time reverse transcription polymerase chain reaction. Results. Exogenous Resistin has induced gastric cancer cells proliferation in a dose-dependent manner and could improve cell viability. Also the expression of Human Telomerase Reverse Transcriptase (hTERT) was upregulated in 24 hours, after Resistin treatment. Conclusions. This study has shown Resistin induces exogenously gastric cancer cell proliferation and increases hTERT gene expression. These findings may clarify the role of Resistin in gastric carcinogenesis. Therefore blocking Resistin signaling and limiting its secretion may be valuable for the treatment of gastric cancer.

Objective: The invasive mammary cancer is the most frequent malignant tumor of a woman. Among the potential prognostic factors are included the biomarkers which measure or are associated with biological processes involved in the tumoral progression.We studied the prognostic importance of the oncoprotein c-erbB2 in the invasive mammary cancer.\r\nMaterials and methods: We included in the study 56 female patients suffering from invasive mammary cancer.The tissue fragments were fitted in formol, included to paraffin, commonly stained with hematoxylin-eosine (HE); for the determination of the c-erbB2 we\r\nused the immunohistochemical method of the avidin-biotin (ABC) complex.\r\nResults: From the total of 56 tumors, 38 (67.9%) presented different degrees of positivity; 18 (32.1%) did not express the oncoprotein c-erbB2.\r\nConclusions: The positivity of oncoprotein c-erbB2 was correlated with the size of the tumor; the carcinomas which are not infiltrative ductal, known as having a better prognostic, were c-erbB2 negative.

Leptin is much more than a simple sensor of body fat levels. Its biological activities, include angiogenesis, osteogenesis and modulation of the immune and reproductive systems. There are no reports on fluctuations of the level in normal human functional glandular epithelium during the menstrual cycle. Objective. We aimed to determine the expression level of the leptin receptor by immunohistochemistry and to correlate this with estrogen and progesterone receptor levels in normal endometrial tissue throughout the menstrual cycle. Study design. Thirty-seven paraffin wax blocks of biopsy specimens of histologically normal endometrium were evaluated and classified according to the stage of the menstrual cycle during the 2004–2006 period. Results. The OB-R level underwent fluctuations during the menstrual cycle in the different tissue compartments; these were most marked in the functional glandular epithelium and during the proliferative stage. OB-R levels were correlated positively with the expression levels of estrogen and negatively with those for progesterone receptors, suggesting that these steroids modulate the expression of OB-R in vivo. Conclusion. This finding underscores the importance of considering the menstrual cycle stage for studies seeking possible impacts of the OB-R on reproductive pathology, because its expression level varies with the hormonal environment.

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Introduction. Symptoms related to hypersecretion of hormones in patients with pituitary adenomas do not always correlate with immunohistochemical staining results. Objective. To evaluate the relationship between the pituitary adenomas hormone immunoexpressions and endocrine presentations. Patients and methods. The clinical status and immunoexpression of 72 patients who underwent transsphenoidal surgery for pituitary adenomas were analyzed. Results. Macroadenomas were diagnosed in 51 cases (70.84%), while microadenomas were found in 21 cases (29.16%). The 72 adenoma specimens were divided into 22 monohormonal, 21 plurihormonal, 21 immunonegative and 8 unreliable specimens. The positive immunohistochemical staining results occurred as follows: prolactin and growth hormone 25% each, adrenocorticotropic hormone 13.89%, thyroid-stimulating hormone 5.56%, leuteinizing hormone and follicle-stimulating hormone 12.5%, glycoprotein hormone alpha-subunit 22.22%. Statistically significant relationships between the immunohistochemical presentation and the preoperative diagnosis were found for prolactin and hyperprolactinemia, growth hormone and acromegaly and adrenocorticotropic hormone and Cushing’s syndrome. Conclusions. The lack of full concordance between the clinical presentations and immunohistochemical staining was mainly a result of the presence of nonfunctioning adenomas, plurihormonal adenomas and unreliable specimens. The morphometric method introduced in this study, utilizing the immunoexpression index, provided a very precise evaluation of pituitary adenomas pathology.