Ultrastructure of the normal human adrenal cortex]

Electron-microscopic investigations on the human adrenal cortex have been carried out in order to elucidate ultrastructural differences in the various zones. These studies indicate that certain differences in the ultrastructure of the mitochondria may be particularly useful as criteria to differentiate the three cortical zones. In this regard, the appearance of two types of mitochondria in the zona glomerulosa as well as in the zona fasciculata is of obvious interest. The probability of a relationship between the activity of the different cortical zones and the predominant presence of one form of mitochondria has been suggested. In addition, ultrastructural transformations following stress situations as well as problems dealing with the so-called 'dark and light cells' and the basal membrane are discussed.     

Ultrastructure of the capsule of the rabbit adrenal gland

The capsule of the normal rabbit adrenal gland was examined with the electron microscope, and three layers are described. The outermost layer consists of collagen and elastic fibrillae, with cytoplasmic processes of fibroblasts in between. Myofibroblasts with parallel cytoplasmic filaments, dense bodies at the inner surface of the plasma membrane and an irregular nuclear outline were seen in the middle layer. The presence of unmyelinated nerves and an axon terminal near to the myofibroblasts of the middle layer raised the possibility of innervation of these cells which could have a contractile function. The basal lamina of the fenestrated capilaries in the inner vascular layer is occasionally fused with that of the outer zona glomerulosa, suggesting a probable route for blood supply and secretion.     

Ultrastructure of human adrenal glands at various periods of prenatal morphogenesis

As demonstrates the electron microscopical investigation of the adrenals in human embryos and fetuses 6--32-week-old, at the age of 10--12 weeks glomerular and fasciculo-reticular zones are already differentiating. Subsequently, during following stages of the prenatal morphogenesis, when ultramicroscopical signs of the zonal belonging of cells and specific activity of steroid-synthesizing organells, the cortical reaction to the birth stress is manifested. Installation of the cells of the medullary substance takes place along nervous fibers, via paravasal and intravascular ways. Formation of the medullary substance by the time of birth is evidently not completed. Some critical estimations on the well known concept of the fetal cortex are presented. As the authors think, it needs to be recomprehended.     

Integrative computational immunogenomic profiling of cortisol-secreting adrenocortical carcinoma

Adrenocortical carcinoma (ACC) is a rare but highly aggressive malignancy. Nearly half of ACC tumours overproduce and secrete adrenal steroids. Excess cortisol secretion, in particular, has been associated with poor prognosis among ACC patients. Furthermore, recent immunotherapy clinical trials have demonstrated significant immunoresistance among cortisol-secreting ACC (CS-ACC) patients when compared to their non-cortisol-secreting (nonCS-ACC) counterparts. The immunosuppressive role of excess glucocorticoid therapies and hypersecretion is known; however, the impact of the cortisol hypersecretion on ACC tumour microenvironment (TME), immune expression profiles and immune cell responses remain largely undefined. In this study, we characterized the TME of ACC patients and compared the immunogenomic profiles of nonCS-ACC and CS-ACC tumours to assess the impact of differentially expressed genes (DEGs) by utilizing The Cancer Genome Atlas (TCGA) database. Immunogenomic comparison (CS- vs. nonCS-ACC tumour TMEs) demonstrated an immunosuppressive expression profile with a direct impact on patient survival. We identified several primary prognostic indicators and potential targets within ACC tumour immune landscape. Differentially expressed immune genes with prognostic significance provide additional insight into the understanding of potential contributory mechanisms underlying failure of initial immunotherapeutic trials and poor prognosis of patients with CS-ACC.     

Primary tissue culture of human adrenocortical Conn's adenomata

Summary Angiotensin II-induced the hypertrophy of the cytoplasmic compartment and significantly increased (5-³H)uridine incorporation into RNA species by Conn's human adult adenomatous cells in primary tissue culture. On its own, bromocriptine, while enlarging only the nucleolar compartment, also intensely stimulated the incorporation of (5-³H)uridine into RNA species by the cultured adrenocortical adenomatous cells. However, an equimolar mixture of angiotensin II and bromocriptine was totally ineffective, eliciting no change in cellular morphometry or isotope incorporation with respect to the control specimens run in parallel.The present findings support the view that bromocriptine can influence the metabolism of Conn's cells directly at the cellular level by acting as an agonist-antagonist of angiotensin.     

Ultrastructure and formation of diaphragmed fenestrae in cultured endothelial cells of bovine adrenal medulla

Summary The ultrastructure of diaphragmed fenestrae and the process of their de novo formation were examined in cultured endothelial cells cloned from fenestrated capillaries of bovine adrenal medulla. One clone frequently formed many diaphragmed fenestrae in highly attenuated regions of endothelium during 1–1.5 months of culture on reconstituted collagen gel. Stereo views of thick sections showed round or oval clusters of geometrically arranged fenestrae, each with a central knob. The number of diaphragmed fenestra per cluster was 50±13/m². The inner diameter of the fenestrae was 50–60 nm. In the cells having small clusters of fenestrae, plasmalemmal vesicles, each having a thin diaphragm with a central knob, were accumulated (56±18/m²) and arranged geometrically, mostly on the basal plasmalemma. At the border between the cytoplasm and the eluster of fenestrae, plasmalemmal vesicles of the basal plasmalemma fused with the opposing apical plamalemma. A model for the process of fenestrae formation in vitro is proposed.     

Ultrastructure of thymus and liver following adrenalectomy and replacement adrenal hormone therapy in rats

Prior research in this laboratory has shown that dexamethasone, aldosterone, and epinephrine interact in regulating the activity of ornithine decarboxylase (EC 4.1.1.17, ODC) in rat thymus and liver. The three primary adrenal hormones were administered alone and in various combinations to adrenalectomized rats. Liver and thymus samples were removed, prepared for electron microscopy, and morphometric analysis of thymic micrographs was performed. It was found that both corticosteroids induced thymic lympholysis and that concurrent administration of epinephrine 'rescued' the lymphocytes. Observations of liver micrographs indicated that changes in liver glycogen deposition vary in response to the hormone treatment regimen. The liver response to a combination of the glucocorticoid and catecholamine was different from the response to the mineralocorticoid and catecholamine, which indicated that the liver response to the two steroids may be mediated via different mechanisms. Evidence is provided to support the conclusion that the influence of the adrenal gland on rat thymus and liver is not restricted to glucocorticoids but may also involve mineralocorticoids and catecholamines.     

Ultrastructure of the adrenal glands in rats under stress after preliminary use of the biostimulator "Biomos"

Adaptogenic influence of biostimulator "Biomos" on the course of stress-reaction in adrenal glands has been shown by the electron-microscopic method. It consists in essential reconstructions of steroidogenesis apparatus directed to potentiation of mineralocorticoid function and to stabilization of the glucocorticoid function as well as to maintenance of structural integrity of substantia medullaris.     

Ultrastructure ofLabyrinthula

Summary Electron microscopic observations of the vegetative colony ofLabyrinthula clearly show that the slimeways, along which the cells glide, are extracellular and completely surround the cells. Membranes of this extracellular matrix have a trilaminar, unit membrane structure that is characteristic of the plasma membrane. The Golgi complex of the cells probably consists of two large dictyosomes. A membrane-limited bundle of parallel filaments of unknown function is usually adjacent to one dictyosome. Specialized invaginations of the plasma membrane, called bothrosomes, may be sites of membrane assembly and secretion of the slimeway matrix, the prerequisite substratum for the gliding cell movement.Portion of a dissertation submitted to the University of Washington in partial fulfillment of the requirements for the degree of Doctor of Philosophy in Botany.     

Ultrastructure of Bacillus pulvifaciens

The ultrastructure of vegetative cells and spores of Bacillus pulvifaciens was studied by CTEM and SEM methods. The vegetative cells are rods, 1.6–4.5 m long and 0.4–0.6 m wide, exhibiting typical ultrastructural features of Gram-positive bacteria. The spores are of ellipsoidal shape, 0.6×1.2 m in size, with six longitudinal ribs reaching up to 130 nm in height. There are satelite ribs on both sides of the longitudinal ribs, reaching up to 20 nm in height. Between the longitudinal ribs, additional transversal ribs were observed in SEM. A special tubular layer, separating the outer and inner coat of the spores, was revealed in ultrathin sections. This layer seems to be a typical ultrastructural feature of Bacillus pulvifaciens spores.