Immunohistochemical detection of angiotensin receptors AT1 and AT2 in adrenal tumors

Angiotensin II is well known to affect the adrenal cell growth and function. Angiotensin receptors AT1 and AT2 were found to be present in the normal adrenal gland. However, the data on the expression of the angiotensin receptors in the adrenal tumors are very scarce. To overcome this gap, the paraffin sections of the adrenal cortical tumors and of pheochromocytomas from the archival material were immunostained with antibodies raised against AT1 (sc-1173) and AT2 (sc-9040) receptor proteins. In hyperplasia of the adrenal cortex and in benign adrenocortical adenomas, both functioning and non-functioning, the AT1 immunostaining was present mainly in the cell membranes. A positive immunoreaction was also found in the subpopulation of cell nuclei and within the cytoplasm. In the adrenal cancer, as well as in pheochromocytomas, neither cell membranes nor cell nuclei were immunostained with anti-AT1 antibody. However, a weak AT1 immunostaining was present within the cytoplasm of tumoral cells. With anti-AT2 antibody, in all tumors investigated, the tumoral cells were immunonegative but moderate to strong AT2 immunostaining was observed in the walls of intratumoral blood vessels and in the interstitial tissue. Our data indicates that the expression of AT1 receptors is altered in adrenal cancer and in pheochromocytomas. The expression of AT2 receptors, in turn, may be connected with the process of tumoral neo-angiogenesis.     

Consensus statement of the Polish Society for Endocrinology: presurgical somatostatin analogs therapy in acromegaly

Consensus statement of the Polish Society for Endocrinology, regarding presurgical somatostatin analogs in acromegaly has been presented. It is suggested to administer depot somatostatin analog (Octreotide LAR at the dose 20 mg and then 30 mg or equivalent doses of Lanreotide Autogel 90/120 mg every 4 weeks) in order to normalize or suppress to a maximal extent GH and IGF-1 concentrations. The period of therapy in case of microadenoma would be at least 3 months (targets: biochemical improvement, reduced risk of disease's complications, perioperative risk reduction, inhibition of tumor growth). The period of therapy in case of macroadenoma would be at least 6 months, until maximal possible reduction of GH and IGF-1 concentrations (targets: tumor shrinkage, biochemical improvement, reduced risk of disease's complications, perioperative risk reduction). Using an uniform approach in a group, as numerous as possible, of treated patients would allow objective evaluation of long-term efficacy of the treatment.     

Recombination in Mitochondrial DNA of European Mussels <Emphasis Type="Italic">Mytilus</Emphasis>

Mitochondrial DNA was long believed to be purely clonal and free from recombination. Major phylogenetic studies still depend on such assumptions. The peculiar genetic system of marine mussels Mytilus in which two divergent mitochondrial genomes exist provides a unique opportunity to study mtDNA recombination. Previous reports showed the existence of a few haplotypes having very strong recombination signal in the control region of mtDNA. Those recombinant variants have been found in a Baltic Sea population of Mytilus trossulus as well as in Mytilus galloprovincialis from the Black Sea. In both cases the mosaic genomes switched their transmission route and have been inherited paternally. In the present study rearranged mtDNA genomes found in all three European Mytilus species are described. The structure of their control region is a result of intra- and intermolecular recombination between mitochondrial genomes. Together with the phylogenetic reconstruction and geographic distribution, this suggests that two interlineage recombination events have occurred in the control region of mtDNA of European mussels Mytilus. Contrary to earlier observations, some of the mosaic genomes do not show any gender bias, which has important implications regarding the transmission and evolution of blue mussel mitochondrial genomes.     

Cancer brings forward oviposition in the fly Drosophila melanogaster

Hosts often accelerate their reproductive effort in response to a parasitic infection, especially when their chances of future reproduction decrease with time from the onset of the infection. Because malignancies usually reduce survival, and hence potentially the fitness, it is expected that hosts with early cancer could have evolved to adjust their life‐history traits to maximize their immediate reproductive effort. Despite the potential importance of these plastic responses, little attention has been devoted to explore how cancers influence animal reproduction. Here, we use an experimental setup, a colony of genetically modified flies Drosophila melanogaster which develop colorectal cancer in the anterior gut, to show the role of cancer in altering life‐history traits. Specifically, we tested whether females adapt their reproductive strategy in response to harboring cancer. We found that flies with cancer reached the peak period of oviposition significantly earlier (i.e., 2 days) than healthy ones, while no difference in the length and extent of the fecundity peak was observed between the two groups of flies. Such compensatory responses to overcome the fitness‐limiting effect of cancer could explain the persistence of inherited cancer‐causing mutant alleles in the wild.     

Degeneration of germ line cells in amphibian ovary

Ogielska, M., Rozenblut, B., Augustyńska, R., Kotusz, A. 2010. Degeneration of germ line cells in amphibian ovary. —Acta Zoologica (Stockholm) 91 : 319–327 We studied the morphology of degenerating ovarian follicles in juvenile and adult frogs Rana temporaria, Rana lessonae and Rana ridibunda. Degeneration of primordial germ cells was never observed and was extremely rare in oogonia and early oocytes in a cyst phase in juveniles. Previtellogenic oocytes were rarely affected. Three main types of atresia were identified. In type I (subdivided into stages A–D), vitellogenic oocytes are digested by proliferating follicle cells that hypertrophy and become phagocytic. A – germinal vesicle shrinks, nucleoli fuse, oocyte envelope interrupts, and follicular cells hypertrophy; B – follicular cells multiply and invade the oocyte; C – entire vesicle is filled by phagocytic cells; D – degenerating phagocytes accumulate black pigment. Type II is rare and resembles breakdown of follicles and release of ooplasm. In type III, observed in previtellogenic and early vitellogenic oocytes, ooplasm and germinal vesicle shrink, follicle cells do not invade the vesicle, and condensed ooplasm becomes fragmented. The residual oogonia in adult ovaries (germ patches) multiply, but soon degenerate.     

Application of surface plasmon resonance toward studies of low-molecular-weight antigen-antibody binding interactions

Methods for studying low-molecular-weight antigen-antibody binding interactions using surface plasmon resonance detection are presented. The experimental parameters most relevant to studies of low-molecular-weight antigen-antibody binding interactions are discussed. Direct kinetic analysis of the binding interactions is most informative, providing both apparent association and dissociation rate constants from which equilibrium constants can be calculated. Equilibrium analysis, including steady-state and solution affinity studies, offers an alternative approach to direct kinetic analysis when knowledge of the individual kinetic rate constants is not required or difficult to determine. The various methods are illustrated by studies of an anti-T(4) Fab fragment binding interaction with several thyroxine analogs. The methods utilized were dependent on the affinity of the interaction. The high-affinity anti-T(4) Fab fragment/l-T(4) binding interaction was evaluated using direct kinetic analysis. An intermediate affinity anti-T(4) Fab fragment/l-T(3) binding interaction was evaluated using a combination of direct kinetic analysis, steady-state analysis, and solution affinity analysis. The relatively weak anti-T(4) Fab fragment/l-T(2) binding interaction was evaluated using steady-state and solution affinity analysis protocols. Several thyroxine tracers that could not be immobilized to a biosensor surface were also evaluated via the solution affinity format. In cases where a given binding interaction was examined using multiple methods the results were comparable.