An Evaluation of the Pharmacodynamics, Safety, and Tolerability of the Potassium Binder RDX7675.

Hyperkalemia is common in patients with heart failure or chronic kidney disease, particularly those taking renin-angiotensin-aldosterone system inhibitors, and can cause arrhythmias and sudden cardiac death. The most widely used treatment, sodium polystyrene sulfonate (SPS), limits gastrointestinal potassium absorption, but has poor palatability. RDX7675 (RDX227675) is the calcium salt of a reengineered polystyrene sulfonate-based resin with improved palatability over SPS.

Evaluation of the Pharmacodynamic Effects of the Potassium Binder RDX7675 in Mice.

Introduction: Hyperkalemia is a common complication in patients with heart failure or chronic kidney disease, particularly those who are taking inhibitors of the renin-angiotensin-aldosterone system. RDX7675, the calcium salt of a reengineered polystyrene sulfonate-based resin, is a potassium binder that is being investigated as a novel treatment for hyperkalemia. This study evaluated the pharmacodynamic effects of RDX7675 in mice, compared to 2 current treatments, sodium polystyrene sulfonate (SPS) and patiromer.

Palatability and physical properties of potassium-binding resin RDX7675: comparison with sodium polystyrene sulfonate.

Background: Hyperkalemia is a potentially life-threatening condition that patients with heart failure or chronic kidney disease, especially those taking renin-angiotensin-aldosterone system inhibitors, are at high risk of developing. Sodium polystyrene sulfonate (SPS), a current treatment, binds potassium within the gastrointestinal tract to reduce potassium absorption. However, poor palatability limits its long-term use.

Gastropericardial fistula: radiologic findings and literature review.

Background: Gastropericardial fistula, a rare condition characterized by an abnormal communication between the stomach and the pericardium, is an emergency as sequelae such as cardiac tamponade and sepsis may lead to hemodynamic instability and death. We aimed to summarize the surgical and radiologic findings of the reported cases published to date, describe their pertinent surgical history, and present an algorithm for diagnosis.

Methods: The Pubmed database was searched using the terms: gastropericardial, pericardiogastric, pneumopericardium, pericardial, and pneumopericardium with the term "fistula" added to each term.

Design of annulated pyrazoles as inhibitors of HIV-1 reverse transcriptase.

Non-nucleoside reverse transcriptase inhibitors (NNRTIs) are recommended components of preferred combination antiretroviral therapies used for the treatment of HIV. These regimens are extremely effective in suppressing virus replication. Structure-based optimization of diaryl ether inhibitors led to the discovery of a new series of pyrazolo[3,4-c]pyridazine NNRTIs that bind the reverse transcriptase enzyme of human immunodeficiency virus-1 (HIV-RT) in an expanded volume relative to most other inhibitors in this class.

First enantiospecific total synthesis of the antitubercular marine natural product pseudopteroxazole. Revision of assigned stereochemistry.

A concise, enantiospecific synthesis of pseudopteroxazole (3), which had originally been assigned structure 1, has been accomplished starting from S-(-)-limonene. The known cyclohexanone 5 was converted in five steps to the alpha,beta-enone 8 by a modified Robinson annulation. Transformation of 8 to the orthogonally protected amino phenol 11 was accomplished by a new modification of the Wolff-Semmler rearrangement.

Calorimetric and structural studies of 1,2,3-trisubstituted cyclopropanes as conformationally constrained peptide inhibitors of Src SH2 domain binding.

Isothermal titration calorimetry and X-ray crystallography have been used to determine the structural and thermodynamic consequences associated with constraining the pTyr residue of the pYEEI ligand for the Src Homology 2 domain of the Src kinase (Src SH2 domain). The conformationally constrained peptide mimics that were used are cyclopropane-derived isosteres whereby a cyclopropane ring substitutes to the N-Calpha-Cbeta atoms of the phosphotyrosine. Comparison of the thermodynamic data for the binding of the conformationally constrained peptide mimics relative to their equivalent flexible analogues as well as a native tetrapeptide revealed an entropic advantage of 5-9 cal mol(-1) K(-1) for the binding of the conformationally constrained ligands.