Design and synthesis of 4-[3,5-dioxo-11-oxa-4,9-diazatricyclo[5.3.1.02,6]undec-4-yl]-2-trifluoromethyl-benzonitriles as androgen receptor antagonists

A novel series of 4-[3,5-dioxo-11-oxa-4,9-diazatricyclo[5.3.1.0^2,6]undec-4-yl]-2-trifluoromethyl-benzonitriles has been synthesized. The ability of these compounds to act as antagonists of the androgen receptor was investigated and several were found to have potent activity in vitro and in vivo.     

Identification and characterization of a unique cysteine residue proximal to the catalytic site of Arabidopsis thaliana carotenoid cleavage enzyme 1

AtCCD1 and AtNCED3 are related carotenoid cleavage enzymes from Arabidopsis thaliana that catalyze the oxidative cleavage of, respectively, the 9,10 (9',10') double bonds of carotenoid substrates such as beta-carotene, and the 11,12 double bond of 9-cis epoxycarotenoids. Although the cellular and cleavage functionalities of these enzymes have been reported, their mechanisms and related structural environments mediating these disparate specificities in homologous enzymes have not been well characterized. By relating the differences observed in UV and visible light absorption and Cu(II) electron paramagnetic signals to variations in sequence alignments and 3-D homology models of the two A. thaliana enzymes, we identified a putatively proximal cysteine residue (Cys352) in AtCCD1 that is not conserved in AtNCED3. Spectral analysis of the Cys to Ala mutant confirmed its uniqueness and proximity to the metal binding site, but precluded any role for the residue in the mediation of the observed metal binding affinity or associated steric constraint differences. Further analysis of kinetic substrate cleavage properties indicated a decrease in Vmax and a subtle increase in Km for the C352A mutant compared with those observed for the wild-type, thus confirming catalytic site proximity and suggesting possible roles for the unique cysteine in the modulation of substrate affinity and (or) the reaction rate of AtCCD1.     

31P-NMR studies of the oral pathogen Streptococcus mutans: Observation of lipoteichoic acid

We have used ³¹P-nuclear magnetic resonance spectroscopy to identify phosphorus-containing compounds in whole cells of two serotype c strains of the oral pathogen Streptococcus mutans. The major resonance, centered at 0 ppm in whole cells, was attributed to lipoteichoic acid on the basis of its chemical shift, insensitivity to pH changes, cellular localization and a comparison with spectra obtained with purified lipoteichoic acid from S. mutans. The linewidths of resonances observed for intact cells and purified lipoteichoic acid were moderately narrowed by increasing the ionic strength, and substantially broadened in the presence of the lectin concanavalin A. Experiments with purified lipoteichoic acid suggest that this compound in whole cells is complexed with divalent cations such as Mg²⁺. Intracellular pools of other phosphorus-containing metabolites were found to be low when compared to the lipoteichoic acid concentration in both starved and glycolyzing cells.     

Evaluation of antral follicle growth in the macaque ovary during the menstrual cycle and controlled ovarian stimulation by high‐resolution ultrasonography

To date, ultrasonography of monkey ovaries is rare and typically of low resolution. The objectives of this study were to use state‐of‐the‐art, high‐resolution, transabdominal ultrasonography with real‐time Doppler capabilities to: (1) determine whether one can reliably detect in real time the large dominant follicle, the corpus luteum (CL), and small (<2 mm) antral follicles on the ovaries of rhesus monkeys during the natural menstrual cycle; and (2) predict the follicular response of rhesus ovaries to controlled ovarian stimulation (COS) protocols. Rhesus monkeys were selected for transabdominal ultrasonography using a GE Voluson 730 Expert Doppler System at discrete stages of the menstrual cycle. Subsequently, serial ultrasound scanning was employed to observe growth of antral follicles and the CL. Finally, females were scanned to assess follicular growth during COS. The dominant structure and small antral follicles (<2 mm) were reliably visualized in real time. The follicle destined to ovulate could be identified by size differential by day 3 of the follicular phase. The number of small antral follicles present before onset of COS protocol correlated positively with the number of metaphase II‐stage oocytes collected after treatment. The results of this study demonstrate that the population dynamics of antral follicle pools can be noninvasively evaluated in monkeys during natural and pharmacologic ovarian cycles. Am. J. Primatol. 71:384–392, 2009. © 2009 Wiley‐Liss, Inc.     

Anatomy and photosynthetic parameters of roots and leaves of two shade-adapted orchids, Dichaea cogniauxiana Shltr. and Epidendrum secundum Jacq.

This study compares photosynthetic and structural features of Dichaea cogniauxiana and Epidendrum secundum leaves and roots. The diurnal titratable acidity fluctuations indicated crassulacean acid metabolism (CAM) in E. secundum leaves, associated with anatomical features like thick cuticle, large and vacuolated cells, and reduced stomata size and frequency. Roots of both species had chloroplasts in their cortical parenchyma. However, neither the roots nor D. cogniauxiana leaves did show tissue sap acidity fluctuations. This indicates C₃ metabolism in these organs. This lack of oscillation of organic acids in Epidendrum roots was at odds with a CAM-like ¹³C ratio, suggesting that in spite of active CO₂ fixation in roots during the day, the bulk of carbon is imported from the leaves. Roots of both species showed Fv/Fm, ΔF/Fm′, ETR values similar to reports from other non-foliar photosynthetic organs. Besides reducing root carbon cost, root photosynthesis may also be important by alleviating potential hypoxia, since water-saturated velamen severely impedes the gas exchange between radicular cortex.