Bilateral Mature Ovarian Teratoma with Torsion in a Premenarchal Girl.

Mature cystic teratoma is the most common type of ovarian tumor in children. Adnexal torsion is the main complication of mature ovarian teratoma. The synchronous bilateral incidence of mature cystic teratoma in premenarchal girls is known to be rare. However, the incidence of adnexal torsion is higher in young girls. A 10-year-old girl presenting with acute abdomen was managed by emergency laparotomy. Bilateral mature ovarian teratoma with adnexal torsion of the right ovary was found. The right ovarian tissue was not viable due to torsion and an oophorectomy was necessary. Cystectomy with preservation of the ovarian tissue of the left ovary was performed. Histopathological diagnosis was bilateral synchronous mature teratoma with necrosis of the right adnexa. Although the risk of malignancy of torsed ovaries and mature teratomas in premenarchal girls is low, their removal is recommended to prevent adnexal torsion. Decision between ovarian tissue sparing surgery or oophorectomy depends on the risk of malignancy, fertility preservation and the avoidance of early menopause.

Silver nanoparticles/montmorillonite composites prepared using nitrating reagent at water and glycerol.

Three procedures (P) were applied to prepare silver nanoparticles on natural Ca-montmorillonite (MT). The intercalation of the montmorillonite with silver nitrate in aqueous solution (P1), the intercalation of the montmorillonite with silver nitrate in glycerol (P2) and the successive combination of both P1 and P2 methods resulted to P3 method. X-ray powder diffraction (XRD), high-resolution transmission electron microscopy (HRTEM) and Fourier Transform Infrared (FTIR) spectroscopy and the molecular modeling were employed to characterize silver nanoparticles and montmorillonite nanocomposite. The P1 produced MT-1 composite with 2.3 wt% Ag and the partially collapsed layered structure. Nanoparticles of silver larger than 20 nm with a lot of planar defects were randomly distributed on the MT-1 surface; nanoparticles smaller than 20 nm were oriented to the montmorillonite substrate. The MT-2 composite from P2 contained only 1 wt% of Ag. The molecular simulation model of MT-2 showed the interlayer space with the exchangeable cations and metallic silver atoms arrangement within the glycerol bilayer. The P3 produced composite MT-3 that contained 2.4 wt% Ag. The nanoparticles > 20 nm size had a well-defined geometry, very small nanoparticles were amorphous. The modeled structure showed the exchangeable cations, Ag+ and Ag0 located close to the silicate layers and monolayer of glycerol molecules in the interlayer space.