Free energy perturbation (FEP)-guided scaffold hopping

Scaffold hopping refers to computer-aided screening for active compounds with different structures against the same receptor to enrich privileged scaffolds, which is a topic of high interest in organic and medicinal chemistry. However, most approaches cannot efficiently predict the potency level of candidates after scaffold hopping. Herein, we identified potent PDE5 inhibitors with a novel scaffold via a free energy perturbation (FEP)-guided scaffold-hopping strategy, and FEP shows great advantages to precisely predict the theoretical binding potencies ΔG FEP between ligands and their target, which were more consistent with the experimental binding potencies ΔG EXP (the mean absolute deviations| Δ G FEP - Δ G EXP |  < 2 kcal/mol) than those ΔG MM-PBSA or ΔG MM-GBSA predicted by the MM-PBSA or MM-GBSA method. Lead L12 had an IC50 of 8.7 nmol/L and exhibited a different binding pattern in its crystal structure with PDE5 from the famous starting drug tadalafil. Our work provides the first report via the FEP-guided scaffold hopping strategy for potent inhibitor discovery with a novel scaffold, implying that it will have a variety of future applications in rational molecular design and drug discovery.

Short-Term Hemodynamic Effects of Apelin in Patients With Pulmonary Arterial Hypertension

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The effects of apelin on pulmonary hemodynamics in patients with PAH are unknown.

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Systemic infusion caused a significant reduction in pulmonary vascular resistance and increase in cardiac output without a change in heart rate or systemic vascular resistance.

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This effect was most prominent in the subgroup of patients receiving concomitant PDE5 inhibition.

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Apelin agonism is a novel potential therapeutic target for PAH.

Apelin agonism causes systemic vasodilatation and increased cardiac contractility in humans, and improves pulmonary arterial hypertension (PAH) in animal models. Here, the authors examined the short-term pulmonary hemodynamic effects of systemic apelin infusion in patients with PAH. In a double-blind randomized crossover study, 19 patients with PAH received intravenous (Pyr¹)apelin-13 and matched saline placebo during invasive right heart catheterization. (Pyr¹)apelin-13 infusion caused a reduction in pulmonary vascular resistance and increased cardiac output. This effect was accentuated in the subgroup of patients receiving concomitant phosphodiesterase type 5 inhibition. Apelin agonism is a novel potential therapeutic target for PAH. (Effects of Apelin on the Lung Circulation in Pulmonary Hypertension; NCT01457170)

Prostate-sparing cystectomy: Potential functional advantages and objective oncological risks; a case series and review

OBJECTIVES

Prostate-sparing cystectomy (PSC) has been debated over the last decade; our aim was to assess the functional results and to evaluate the oncological outcome after PSC, to judge the value of this technique.

PATIENTS AND METHODS

Twenty-six men (median age 62 years) who were candidates for radical cystectomy were operated between 2004 and 2009 in the urology departments of Foch Hospital, Suresnes, France, and Theodor Bilharz Research Institute, Giza, Egypt. They all underwent a PSC with orthotopic bladder substitution. The functional results were assessed at 1, 3 and 6 months, with the final results evaluated at 1 year. Incontinence was classified according to pads used per day, and erectile function after PSC was assessed using the International Index of Erectile Function questionnaire. There was a strict follow-up for oncological failure, with special attention given to the remnant of the prostate and prostatic urethra.

RESULTS

The final functional results were assessed at 1 year, with daytime continence achieved in 22 patients (95%) and nocturnal leak in four (13%). At 1 year, 18 patients (83%) reported having erections on sexual stimulation. The median follow-up was 43 months, with an overall incidence of recurrence of 30% and a median time to metastasis of 30 months. At 36 months, the overall survival rate was 81%, with a tumour-free survival rate of 70%.

CONCLUSION

PSC was no better than standard radical cystectomy, and should only be offered to patients who prefer preservation of their sexual function and continence over appropriate tumour control.