Diaryl hydroxylamines as pan or dual inhibitors of indoleamine 2,3-dioxygenase-1, indoleamine 2,3-dioxygenase-2 and tryptophan dioxygenase

Tryptophan (Trp) catabolizing enzymes play an important and complex role in the development of cancer. Significant evidence implicates them in a range of inflammatory and immunosuppressive activities. Whereas inhibitors of indoleamine 2,3-dioxygenase-1 (IDO1) have been reported and analyzed in the clinic, fewer inhibitors have been described for tryptophan dioxygenase (TDO) and indoleamine 2,3-dioxygenase-2 (IDO2) which also have been implicated more recently in cancer, inflammation and immune control. Consequently the development of dual or pan inhibitors of these Trp catabolizing enzymes may represent a therapeutically important area of research. This is the first report to describe the development of dual and pan inhibitors of IDO1, TDO and IDO2.

Synergistic Visible-Light Photoredox/Nickel-Catalyzed Synthesis of Aliphatic Ketones via N-C Cleavage of Imides

An electrophilic, imide-based, visible-light-promoted photoredox/Ni-catalyzed cross-coupling reaction for the synthesis of aliphatic ketones has been developed. This protocol proceeds through N-C(O) bond activation, made possible through the lower activation energy for metal insertion into this bond due to delocalization of the lone pair of electrons on the nitrogen by electron-withdrawing groups. The operationally simple and mild cross-coupling reaction is performed at ambient temperature and exhibits tolerance for a variety of functional groups.

Objective Assessment of Cervical Stiffness after Administration of Misoprostol for Intrauterine Contraceptive Insertion

PURPOSE

The goal of this study was to objectively quantify cervical stiffness in misoprostol users prior to IUC insertion and at follow-up consultation to evaluate the feasibility of assessing cervical stiffness and to study the influence of misoprostol on cervical softening.

MATERIALS AND METHODS

This was a cross-sectional study that evaluated 40 women who wished to use the LNG IUS. These women were evaluated immediately before LNG IUS insertion and 6 weeks later at follow-up consultation. Participants received 200 μg of misoprostol combined with 75 mg of diclofenac in a single tablet orally (Arthrotec forte 75/200(®), Pfizer, USA) 6-12 h prior to insertion in "off label" use. On both occasions, cervical stiffness was determined using a novel medical device based on the aspiration technique. The Wilcoxon rank-sum and the Wilcoxon signed-rank test were applied to compare cervical stiffness assessments at insertion of the IUD and at follow-up.

RESULTS

For the first time, cervical stiffness was quantitatively assessed in misoprostol users prior to IUD insertion, proving that the aspiration technique enables detection of pharmacologically induced cervical changes, and also that misoprostol has a detectable softening effect on cervical tissue.

CONCLUSION

The clinical value of the detected cervical softening after misoprostol administration remains unclear. Aspiration measurements could be helpful in searching for the ideal candidate, the appropriate route, dosage and interval of misoprostol intake prior to IUC insertion.

O-alkylhydroxylamines as rationally-designed mechanism-based inhibitors of indoleamine 2,3-dioxygenase-1

Indoleamine 2,3-dioxygenase-1 (IDO1) is a promising therapeutic target for the treatment of cancer, chronic viral infections, and other diseases characterized by pathological immune suppression. Recently important advances have been made in understanding IDO1's catalytic mechanism. Although much remains to be discovered, there is strong evidence that the mechanism proceeds through a heme-iron bound alkylperoxy transition or intermediate state. Accordingly, we explored stable structural mimics of the alkylperoxy species and provide evidence that such structures do mimic the alkylperoxy transition or intermediate state. We discovered that O-benzylhydroxylamine, a commercially available compound, is a potent sub-micromolar inhibitor of IDO1. Structure-activity studies of over forty derivatives of O-benzylhydroxylamine led to further improvement in inhibitor potency, particularly with the addition of halogen atoms to the meta position of the aromatic ring. The most potent derivatives and the lead, O-benzylhydroxylamine, have high ligand efficiency values, which are considered an important criterion for successful drug development. Notably, two of the most potent compounds demonstrated nanomolar-level cell-based potency and limited toxicity. The combination of the simplicity of the structures of these compounds and their excellent cellular activity makes them quite attractive for biological exploration of IDO1 function and antitumor therapeutic applications.

Challenging the in-vivo assessment of biomechanical properties of the uterine cervix: A critical analysis of ultrasound based quasi-static procedures

Measuring the stiffness of the uterine cervix might be useful in the prediction of preterm delivery, a still unsolved health issue of global dimensions. Recently, a number of clinical studies have addressed this topic, proposing quantitative methods for the assessment of the mechanical properties of the cervix. Quasi-static elastography, maximum compressibility using ultrasound and aspiration tests have been applied for this purpose. The results obtained with the different methods seem to provide contradictory information about the physiologic development of cervical stiffness during pregnancy. Simulations and experiments were performed in order to rationalize the findings obtained with ultrasound based, quasi-static procedures. The experimental and computational results clearly illustrate that standardization of quasi-static elastography leads to repeatable strain values, but for different loading forces. Since force cannot be controlled, this current approach does not allow the distinction between a globally soft and stiff cervix. It is further shown that introducing a reference elastomer into the elastography measurement might overcome the problem of force standardization, but a careful mechanical analysis is required to obtain reliable stiffness values for cervical tissue. In contrast, the maximum compressibility procedure leads to a repeatable, semi-quantitative assessment of cervical consistency, due to the nonlinear nature of the mechanical behavior of cervical tissue. The evolution of cervical stiffness in pregnancy obtained with this procedure is in line with data from aspiration tests.