Measurement of estradiol, estrone, and testosterone in postmenopausal human serum by isotope dilution liquid chromatography tandem mass spectrometry without derivatization.

Background: A high-throughput, sensitive, specific, mass spectrometry-based method for quantitating estrone (E1), estradiol (E2), and testosterone (T) in postmenopausal human serum has been developed for clinical research. The method consumes 100μl human serum for each measurement (triplicates consume 300μl) and does not require derivatization. We adapted a commercially available 96-well plate for sample preparation, extraction, and introduction into the mass spectrometer on a single platform.

Clinical Study and Review of Articles (Korean) about Retrorectal Developmental Cysts in Adults.

Purpose: A retrorectal developmental cyst (tailgut cyst, epidermoid cyst, dermoid cyst, teratoma, and duplication) is very rare disease, and the symptoms are not characteristic so that sometimes this disease is still misdiagnosed as a supralevator abscess or a complex anal fistula. We would like to present a clinical approach to this disease.

Methods: We retrospectively examined the charts of 15 patients who were treated for retrorectal cysts from January 2001 to November 2009.

Five- and Six-Coordinate Group 4 Compounds Stabilized by beta-Ketiminate and Diketiminate Ligands: Syntheses and Comparisons between Solid-State and Solution Structures.

The preparation and reaction chemistry of beta-diketiminate titanium and zirconium complexes is described. Amine elimination reactions work well for introducing Tolnacnac or Tolnacac to the metal centers (TolnacnacH = 2-(p-tolylamino)-4-(p-tolylimino)-2-pentene; TolnacacH = 4-p-toluidinopent-3-en-2-one). In certain cases, the iminium salt of the diketimine can be used to circumvent the unfavorable reaction kinetics.