Cushing's syndrome in pregnancy: a case report and mini review of the literature.

Adrenal diseases in pregnant women are diagnosed relatively rarely. The main cause of hypercortisolemia during pregnancy is Cushing's syndrome related to adrenal adenoma. It is important to diagnose Cushing's syndrome in pregnant women because it can lead to significant maternal and foetal complications and morbidity. However, due to physiological endocrine changes and symptoms in pregnant women the diagnosis of this disorder can be a challenge. One current case describes a 38-year-old pregnant woman with hypertension, oedema and an adrenal tumour. At the beginning, Conn syndrome was suspected, but after careful analysis Cushing's syndrome (with an adenoma of the right adrenal gland) was diagnosed. After delivery and 5 weeks of pharmacological treatment the patient underwent right side adrenalectomy by laparoscopy.

The gas phase anisole dimer: a combined high-resolution spectroscopy and computational study of a stacked molecular system.

The gas phase structures of anisole dimer in the ground and first singlet electronic excited states have been characterized by a combined experimental and computational study. The dimer, formed in a molecular beam, has been studied by resonance-enhanced multiphoton ionization and high-resolution laser-induced fluorescence techniques. The assignment of the rotational fine structure of the S(1) <-- S(0) electronic transition origin has provided important structural information on the parallel orientation of aromatic rings of anisole moieties. By comparison with the DFT/TD-DFT computational results, it has been possible to infer the detailed equilibrium structure of the complex. The analysis of the equilibrium structure and interaction energy confirms that the anisole dimer is stabilized by dispersive interaction in the gas phase. This is, to the best of our knowledge, the first detailed work (reporting both theoretical and high-resolution experimental data) on an isolated cluster in the pi-stacking configuration.

Accurate ab initio based DMBE potential energy surface for the ground electronic state of N2H2.

A global single-sheeted double many-body expansion potential energy surface is reported for the ground electronic state of N(2)H(2). Starting from an approximate cluster expansion of the molecular potential that utilizes previously reported functions of the same family for the triatomic fragments, four-body energy terms have been calibrated from extensive accurate ab initio data so as to reproduce the main features of the title system. The switching function formalism previously suggested for three-body systems [A. J. C. Varandas and L. Poveda, Theor. Chem. Acc. 116, 404 (2006)] has been generalized to approximate the true multisheeted nature of N(2)H(2) potential energy surface, thus allowing the correct behavior at the N((2)D) + NH(2)((2)A(")) and N((4)S) + NH(2)((4)A(")) dissociation limits. The resulting fully six-dimensional potential energy function reproduces the correct symmetry under permutation of identical atoms and predicts the main stationary points of the molecule in the valence and long-range regions in good agreement with available experimental and theoretical data on the diazene molecule.

Predicting catalysis: understanding ammonia synthesis from first-principles calculations.

Here, we give a full account of a large collaborative effort toward an atomic-scale understanding of modern industrial ammonia production over ruthenium catalysts. We show that overall rates of ammonia production can be determined by applying various levels of theory (including transition state theory with or without tunneling corrections, and quantum dynamics) to a range of relevant elementary reaction steps, such as N(2) dissociation, H(2) dissociation, and hydrogenation of the intermediate reactants. A complete kinetic model based on the most relevant elementary steps can be established for any given point along an industrial reactor, and the kinetic results can be integrated over the catalyst bed to determine the industrial reactor yield. We find that, given the present uncertainties, the rate of ammonia production is well-determined directly from our atomic-scale calculations. Furthermore, our studies provide new insight into several related fields, for instance, gas-phase and electrochemical ammonia synthesis. The success of predicting the outcome of a catalytic reaction from first-principles calculations supports our point of view that, in the future, theory will be a fully integrated tool in the search for the next generation of catalysts.

Solvent effect on hydrogen bonded ammonia-hydrogen halide complexes: continuum medium versus cluster models

The influence of water and dinitrogen environment on the structures of hydrogen bonded XH-NH3 (X = F, Cl, and Br) complexes has been investigated using the self-consistent isodensity polarizable continuum solvent model (SCI-PCM) with two values of dielectric constants, 1.5 and 78.0, respectively. The geometrical parameters, along with the interaction energies as well as harmonic frequencies were calculated at the B3M-LYP/6-311 + + G(d,p) level of theory. The results from dielectric continuum model were compared with those obtained by traditional supermolecule approach. In order to model the proton transfer in XH-NH3 systems by supermolecular approach, one should add from two to four explicit water or dinitrogen molecules to the calculations. The dielectric continuum model provides similar effect using less effort. As our results shown, the SCI-PCM model, where a solvent is treated as a continuum medium, reproduces quite accurately the molecular properties of investigated medium strong hydrogen bonded systems both with dinitrogen and water environment. In order to represent solvent effects on hydrogen-bonded complexes with less acidic HX subunit it is necessary to take explicit solvent molecules into account.

CD56(NCAM) antigen in glandular epithelium of human thyroid: light microscopic and ultrastructural study.

CD56 antigen, an isoform of the neural cell adhesion molecule (NCAM) was previously found by us in human thyroid by APAAP immunohistochemistry in light microscopy on frozen tissue sections. In the current study, it was attempted to trace the antigen in question using another light microscopic immunohistochemical procedure and to validate the results at the ultrastructural level. For light microscopy, cryostat sections of 12 surgical samples of human thyroid were subjected to ABC (preformed avidin-biotin-peroxidase complex) method. For immunoelectron microscopy, immunoperoxidase reaction was carried out on prefixed, small thyroid tissue blocks. Following preliminary inspection of semithin sections, ultrathin sections were examined in the transmission electron microscope. ABC reaction revealed distinct specific CD56 staining of thyrocyte cell membranes. The staining was weak or absent in thyroid papillary carcinoma cells. The results were confirmed in semithin sections by indirect immunoperoxidase. The latter reaction in ultrathin sections at the ultrastructural level has shown that specific reaction product was confined to free and lateral surfaces of thyroid follicular cells. Endothelial cell membranes of thyroid capillary vessels were totally devoid of the reaction product. The reaction was weakly positive in thyroid follicular and papilllary carcinomas but absent from medullary carcinoma.

Protein and mRNA expression of CD56/N-CAM on follicular epithelial cells of the human thyroid.

In order to confirm CD56/N-CAM antigen prevalence in the human thyroid and to compare its expression on thyrocytes and NK cells, an expression of CD56/N-CAM antigen was searched for on isolated thyroid follicular cells and NK cells by flow cytometry. In addition, mRNA for CD56 was searched for in RNA isolated from human thyroid samples and few other organs using dot blot hybridization assay to prove the existence of mechanisms for active synthesis of the protein in question. The isolated cells from the follicular epithelium of 22 various pathological thyroid tissue specimens were examined for the expression of CD56/N-CAM in terms of the percentage of positive cells and the mean fluorescence intensity (MFI). Blood lymphocytes were tested in parallel. The total RNA isolated from thyroid and control tissue specimens was subjected to dot-blot hybridization assay using CD56/N-CAM cDNA probe. All thyroid specimens expressed CD56/N-CAM, but the obtained values differed depending on the tissue examined and the CD56 antibody used. There were no significant differences between the non-malignant thyroid cells of various histology, while cells in the carcinoma group had a much lower MFI, especially the median value. CD56 expression on NK cells from the donors' blood had a homogeneous distribution but the mean and median values of FI were almost three times lower than those on the thyroid cells. Dot blot hybridization came out positive with the RNA isolated from the thyroid specimens and also from the RNA isolated from the tonsil and lymph nodes, but came out negative with the RNA isolated from human and rat kidneys. These results strongly suggest that thyroid follicular epithelial cells express both protein and mRNA of CD56/N-CAM, thus being able to synthesis the relevant antigen. The protein expression seems to be affected by the malignant transformation of the thyroid cells. NK cells have apparently lower CD56/NCAM expression than thyroid cells.

The level of MAP kinase activity in the stomach stump in rats after subtotal gastrectomy.

MAPK (Mitogen-Activated Protein Kinase) is one of the elements of kinase cascades (MAPK, MEK-MAP kinase, kinase, Raf-1, Ras) regulating cellular proliferation and differentiation processes. It seems that the changes in its number and activity may be the factor having influence on carcinogenesis. In some human carcinomas a significant increase of its activity is observed, in others a decrease of its activity is described. Our research aimed at the evaluation of the dynamics of precancerous and cancerous changes in the stomach stump in rats after the experimental, partial stomach resection. Apart from histological and ultrastructural examination we also determined the activity of the sub-unit p42 MAP kinase. The material comprised segments of gastric mucosa of the stomach stump of 15 rats after subtotal gastrectomy. Part of the rats after the procedure were administered carcinogen orally (MNNG). On the histological and ultrastructural examination we used routine methods, the activity of MAP kinase was determined by western-blotting method with the use of IgG against MAPK p42, Santa Cruz #154). In 8 examined rats we observed the increase of MAP kinase activity. We established probable correlation (without statistical analysis, regarding miserly material) between the increase of MAPK activity and histological and ultrastructural changes. Among three cases diagnosed as adenoma tubulare in two we observed the increase of MAPK activity. A clear increase of this kinase was also present in the stomach stump of a rat, which was diagnosed as adenocarcinoma. On the basis of our research carried so far we think that the increase of the MAPK activity may be one of the causes of the neoplasm development. It seems important to obtain the confirmation of our results and to establish a possible usefulness of MAPK activity determination as a prognostic indicator in case of the neoplasm of stomach stump.

Ultrastructural changes in the small bowel epithelium after total gastrectomy.

The purpose of the study was to analyze ultrastructural changes in the small bowel mucosa in patients after total gastrectomy. We studied mucosal specimens obtained from 25 patients during control gastroscopy. The specimens were routinely processed for examination in transmission electron microscopy. Early after the operation (up to 6 months) we observed marked inflammatory reaction, disordered architecture of the small bowel mucosa epithelium, the presence of dysplasia-like changes and foci of dysplasia. Later on the structure of the mucosa returned to normality. Only a few dysplastic changes were seen. No relationship was found between altered epithelial structure and type of operation. In conclusion, the epithelium of the small bowel does not transform to a gastric type epithelium.

Ultrastructural changes in the small intestinal epithelium after total resection of the colon.

UNLABELLED: The aim of the study was to analyze ultrastructural changes in the mucosa of the small intestine after total resection of the colon in 29 patients (familial polyposis in 21, ulcerative colitis in 8). We studied specimens of the small intestinal mucosa obtained from ano- and rectoscopy. The specimens were routinely processed for transmission electron microscopy. Early after the operation (up to 4-5 months) we observed marked structural disorders of the mucosal epithelium and regenerative cell atypia (dysplasia-like changes). At 6 months after the operation we found rapidly progressing normalization of the epithelial mucosa and its mimicking the epithelium of the colon: increased amount of mucous cells, formation of vacuolized cells, almost complete atrophy of microvilli on the surface of enterocytes, increase of the intercellular space (retention space). Foci with dysplasia features were quite numerous in group I, in contrast to group II where they were sporadic. CONCLUSION: the epithelium of small intestinal mucosa has the ability of convergence towards the epithelium of colon.