Adnexal masses: benign ovarian lesions and characterization - benign ovarian masses

Incidental adnexal masses are commonly identified in radiologists’ daily practice. Most of them are benign ovarian lesions of no concern. However, sometimes defining the origin of a pelvic mass may be challenging, especially on ultrasound alone. Moreover, ultrasound not always allows the distinction between a benign and a malignant adnexal tumor. Most of sonographically indeterminate adnexal masses turn out to be common benign entities that can be readily diagnosed by magnetic resonance imaging. The clinical impact of predicting the likelihood of malignancy is crucial for proper patient management. The first part of this chapter will cover the technical magnetic resonance imaging aspects of ovarian lesions characterization as well as the imaging features that allow the radiologist to correctly define the anatomic origin of a pelvic mass. Next, the authors will go through different benign ovarian entities and through the different histologic types of benign ovarian tumors. Finally the functional ovarian tumors and the ovarian tumors in children, adolescents, young females, and pregnant women will be covered.info:eu-repo/semantics/publishedVersio

Molecular basis for diversification of yeast prion strain conformation

Self-propagating β-sheet–rich fibrillar protein aggregates, amyloidfibers, are often associated with cellular dysfunction and disease.Distinct amyloid conformations dictate different physiological consequences,such as cellular toxicity. However, the origin of the diversityof amyloid conformation remains unknown. Here, we suggest thataltered conformational equilibrium in natively disordered monomericproteins leads to the adaptation of alternate amyloid conformationsthat have different phenotypic effects. We performed acomprehensive high-resolution structural analysis of Sup35NM, anN-terminal fragment of the Sup35 yeast prion protein, and foundthat monomeric Sup35NM harbored latent local compact structuresdespite its overall disordered conformation. When the hidden localmicrostructures were relaxed by genetic mutations or solvent conditions,Sup35NM adopted a strikingly different amyloid conformation,which redirected chaperone-mediated fiber fragmentation and modulatedprion strain phenotypes. Thus, dynamic conformational fluctuationsin natively disordered monomeric proteins represent aposttranslational mechanism for diversification of aggregate structuresand cellular phenotypes

Exacerbation of autoimmune thyroiditis by a single low dose of whole-body irradiation in non-obese diabetic-H2(h4) mice.

Purpose: To evaluate how irradiation affects thyroid autoimmunity in mouse models of Hashimoto\u27s thyroiditis and Graves\u27 hyperthyroidism. Materials and methods: Non-obese diabetic (NOD)-H2(h4) mice spontaneously develop anti-thyroglobulin (Tg) antibodies and thyroiditis when supplied with sodium iodine (NaI) in the drinking water. BALB/c mice develop anti-thyrotropin receptor (TSHR) antibodies and hyperthyroidism following immunization with adenovirus expressing TSHR (Ad-TSHR). Mice were irradiated as follows: A single whole-body irradiation with 0.05, 0.5 or 3 Gy one week before or after the beginning of NaI or immunization with Ad-TSHR, fractionated whole-body irradiations with 0.05 Gy twice a week or 0.5 Gy once a week from one week before NaI or Ad-TSHR immunization, or a single regional irradiation to the thyroid gland with 0.5 Gy one week before NaI. The effect of a single irradiation with 0.05, 0.5 or 3 Gy on splenocytes was also evaluated. Results: A single whole-body irradiation with 0.5 Gy one week before NaI exacerbated thyroiditis and increased anti-Tg antibody titers in NOD-H2(h4) mice. In contrast, any irradiation protocols employed did not affect incidence of hyperthyroidism or anti-TSHR antibody titers in BALB/c mice. High-dose irradiation increased the relative ratios of effector T cells to regulatory T cells (an indication of enhanced immune status) but kills most of T cells. Conclusions: These results indicate that a single whole-body low-dose irradiation with 0.5 Gy exacerbates thyroiditis in NOD-H2(h4) mice, data consistent with some clinical evidence for increased incidence of thyroid autoimmunity by environmental irradiation