The Involvement of Angiotensin Type 1 and Type 2 Receptors in Estrogen-Induced Cell Proliferation and Vascular Endothelial Growth Factor Expression in the Rat Anterior Pituitary

The aim of our study was to examine the involvement of renin-angiotensin system (RAS) in estrogen-induced lactotropes proliferation and vascular endothelial growth factor (VEGF) expression in rat pituitary. The study was performed on Fisher 344 rats underwent 8-day treatment with diethylstilboestrol (DES). The proliferation index (PCNA) and VEGF expression in pituitary sections were estimated using immunohistochemical methods. Treatment with DES increased the number of PCNA-positive cells, VEGF-positive cells, and VEGF-positive blood vessels in pituitary. Stimulatory effect of estrogen on cell proliferation and VEGF expression in blood vessels was attenuated by losartan, PD123319, and captopril. VEGF immunoreactivity in pituitary cells of DES-treated rats was decreased by AT1 antagonist and not changed by AT2 blocker and ACE inhibitor. Our findings suggest the involvement of RAS in DES-induced cell proliferation and VEGF expression in pituitary. Both the AT1 and AT2 receptors appear to mediate the estrogen-dependent mitogenic and proangiogenic effects in rat pituitary

Interferon alpha and rapamycin inhibit the growth of pheochromocytoma PC12 line in vitro

Wstęp: Guzy chromochłonne (pheochromocytoma/paraganglioma) należą do łagodnych lub złośliwych nowotworów neuroendokrynnych.Wobec niezadowalającej skuteczności standardowych sposobów leczenia pacjentów z rozsianą postacią choroby, wciąż poszukuje się nowych metod terapii, w tym możliwości skutecznego leczenia celowanego. W związku ze wzmożonym unaczynieniem tych nowotworów, preparaty o działaniu antyangiogennym mogą potencjalnie stanowić nową grupę leków stosowanych w leczeniu pheochromocytoma/paraganglioma.Materiał i metody: W badaniu oceniano wpływ różnych angiomodulatorów: VEGF (naczyniowo-środbłonkowy czynnik wzrostu) orazpięciu endo- i egzogennych czynników antyangiogennych (endostatyna; IFN-alfa [interferon alfa]; rapamycyna — inhibitor szlaku mTOR[mammalian target of rapamycin]; JV1-36 and SU5416 [semaxinib]) na wzrost szczurzej linii pheochromocytoma PC12.Wyniki: IFN-alfa (105 U/mL) silnie hamował wzrost komórek PC12 w hodowli 72 h, nasilając apoptozę i hamując cykl komórkowy. Rapamycynaw szerokim zakresie stężeń (10-5 to 10-8 M) nieznacznie zmniejszała żywotność komórek PC12, a w stężeniu 10-5 M także hamowałaich proliferację. VEGF, endostatyna oraz JV1-36 nie wpływały na wzrost lini PC12.Wnioski: W badaniu po raz pierwszy wykazano, że IFN-alfa hamuje wzrost linii komórkowej pheochromocytoma PC12, a także potwierdzonohamujący wpływ rapamycyny wobec tej linii komórkowej. Uzyskane wyniki sugerują zatem, że IFN-alfa oraz inhibitory szlakumTOR mogą być potencjalnie skuteczne w leczeniu złośliwych postaci guzów chromochłonnych i zachęcają do dalszych badań w tymkierunku.(Endokrynol Pol 2013; 64 (5): 368–374)Introduction: Pheochromocytomas are benign or malignant neuroendocrine tumours. The unsatisfactory efficacy of the traditionaltherapeutic methods for patients with metastatic disease results in a continuing search for more effective and targeted agents. Due to theincreased vascularisation of these tumours, inhibitors of angiogenesis could be potentially a new group of drugs in pheochromocytoma/paraganglioma therapy.Material and methods: The aim of this study was to evaluate the influence of angiomodulators: VEGF (vascular endothelial growth factor)and five endogenous and exogenous antiangiogenic compounds (endostatin; IFN-alpha [interferon alpha]; rapamycin — mTOR [mammaliantarget of rapamycin] inhibitor; JV1-36 and SU5416 (semaxinib]) on the growth of rat pheochromocytoma PC12 cell line.Results: IFN-alpha (105 U/mL) strongly inhibited PC12 growth in a 72 h culture, increasing apoptosis and arresting the cell cycle. Rapamycinin a wide range of concentrations (10-5 to 10-8 M) induced a slight inhibitory effect on PC12 viability and decreased cell proliferation at theconcentration of 10-5 M. VEGF, endostatin and JV1-36 did not influence the growth of PC12.onclusions: The study has shown for the first time that IFN-a inhibited the growth of pheochromocytoma PC12 line and confirmed theinhibitory action of rapamycin on these cells. The results suggest that IFN-alpha and mTOR inhibitors could be potentially effective in thetherapy of malignant pheochromocytoma, and encourage further study in this field.(Endokrynol Pol 2013; 64 (5): 368–374

Analysis of communication in the educational process by means of e-learning

Purpose: The aim of the research is to analyse communication in the educational process by means of e-learning. Approach/Methodology/Design: An analysis of relevant foreign literature was conducted. A communication model and a comparative analysis of synchronous communication tools based on established criteria were indicated. For the comparative analysis normal distribution, descriptive analysis methodology and chi-quadrate distribution with T-student distribution were used. Findings: The analysis of the presented research results shows that most respondents prefer to solve tasks at a distance in any form. Students are satisfied with the adopted solutions, as well as with the offered methods of communication. The introduction of e-learning positively influences the acquisition and dysfunction of knowledge by students. Practical Implications: Distance communication is a very popular means of communication in the 21st century. The use of various tools does not create a barrier and is evidence of high technological progress. Originality/Value: An original literary approach from the most recent international positions was presented and authorial research was carried out on a representative group of respondents. It is shown that the transfer and acquisition of knowledge by means of information and communication technologies has contributed to changes at universities.peer-reviewe

Elevated Peripheral Blood Plasma Concentrations of Tie-2 and Angiopoietin 2 in Patients with Neuroendocrine Tumors

Background: Gastro-entero-pancreatic/neuroendocrine (NET) tumors are highly vascularized neoplasms. However, our knowledge concerning circulating levels of the angiogenic factors in NET patients still remains insufficient. Methods: The aim of this study was to measure plasma concentrations of VEGF, angiopoietin 1 (Ang-1), angiopoietin 2 (Ang-2), soluble Tie-2, endostatin, osteopontin (OPN) and chromogranin A (CgA) in 36 NET patients and 16 controls. Results: Only the plasma concentrations of Tie-2 and CgA were higher in NET patients as compared to controls. These levels were within the reference range in controls; however one control demonstrated slightly elevated Tie-2 and 4 elevated CgA. Similarly, in the subgroup of patients with carcinoid syndrome, only Tie-2 and CgA concentrations were higher than those in patients with non-functioning NETs. In turn, in the subgroup of metastatic patients, only Ang-2 levels were higher than in those with localized disease. A positive correlation was found between Ang-2 and Tie-2 levels in metastatic patients and between Ang-1 and Tie-2 in localized NETs. Conclusions: The plasma concentration of Tie-2 is proposed as an additional marker for NET patients and seems to be similarly effective as the currently used CgA level. Moreover, higher plasma levels of Ang-2 together with the positive correlation between Ang-2 and Tie-2 levels in metastatic subjects, implies that cases with a Tie-2 level above the upper limits, together with higher level of Ang-2 seem to be highly predictive of metastases

Serum Concentrations of TNF α and Its Soluble Receptors in Patients with Adrenal Tumors Treated by Surgery

The peripheral blood levels of TNF α and its soluble receptors were studied in 39 patients with malignant and benign adrenal tumors treated by adrenalectomy. The concentrations of TNF α were significantly elevated in patients with malignant tumors of the adrenal cortex and in patients with Conn’s syndrome compared to control. In patients with non-functioning adenomas and pheochromocytomas, TNF α levels were similar to those detected in the control. In subjects with myelolipomas, the serum concentration of TNF α was lower compared to the control. After adrenalectomy, the levels of TNF α were decreased in patients with malignant tumors and in patients with Conn’s syndrome, nonfunctioniong adenomas and pheochromocytomas compared to the concentration before surgery. The serum concentrations of soluble receptors of TNF α did not differ among different patient groups and compared to the control. After adrenalectomy, the blood concentrations of TNF α R1 and TNF α R2 were decreased in patients with Conn’s syndrome. However, to confirm practicality of the evaluation of TNF α and its soluble receptors in differential diagnosis in patients with adrenal tumors, a larger study group is needed

The effect of mesulergine on prolactin secretion and anterior pituitary cells morphology in diethylstilboestrol-treated female Wistar rats

Mesulergine (Cu32-085) is an active semisynthetic ergot alkaloid with unusual biphasic antagonistic-agonistic effect on dopamine (DA) turnover in the rat striatum. The present study has been made to elucidate the influence of the long-term treatment of this drug on prolactin secretion and prolactin cells morphology in the female Wistar rats with experimentally-induced hyperprolactinemia. Additionally, the effect of this drug was compared with bromocriptine and pergolide activity, applied in the same experimental conditions. It has been shown that prolonged mesulergine treatment attenuated the stimulatory effect of stilboestrol on prolactin secretion in vivo. It also decreased mean prolactin cells density, above all cells and lactotroph mitotic indexes, estimated in immunohistochemically-stained slides. However, antiproliferative activity of Cu 32-085 was weaker, when compared with bromocriptine and pergolide

Somatostatin and its analog enhance the formation of human leukocyte migration inhibiting factor: Further evidence for immunomodulatory action of somatostatin

The effect of somatostatin-14 (SST) and somatostatin analog D-Phe-Cys-Phe-D-Trp-Lys-Thr-Cys-Thr-NH 2 (RC-102) on migration inhibition of human leukocytes induced by cardiac antigen or phytohemagglutinin (PHA) was investigated. Both SST and RC-102 augmented the migration inhibition, thus indicating the enhanced formation or action of the leukocyte migration inhibiting factor (LMIF). This finding provides additional evidence for the immunomodulatory action of somatostatin

Biologically active thymones from the thymus

A class of three substances has been isolated in highly purified form and in substantially pure form by utilizing thymus tissue as a source material. These three substances are designated thymone A, thymone B and thymone C. Thymones A and B are new peptides which yield approximately 13 and 14 individual amino acid moieties, respectively, on acid hydrolysis. Thymones A and B are chemically characterized by electrophoretic and chromatographic values which are appropriate for substances which are substantially pure. Thymone C was highly purified and its biological activity was reproducibly detected and measured. Thymones A, B and C stimulate the proliferation of lymphocytes. Thymone A stimulates the formation of cyclic adenosine monophosphate. Thymone B stimulates the formation of cyclic guanosine monophosphate. The biological activities of these thymones to stimulate the proliferation of lymphocytes and the formations of cyclic nucleotides are basic hormonal functions for the therapeutic enhancement of the immune system in patients who have immune deficiencies from diverse causes.Board of Regents, University of Texas Syste