Pulmonary Arterial Hypertension: Too Complex for Physicians, Too Complex for ICD Diagnosis Codes

Phosphodiesterase 5 (PDE5) inhibitors are potent enzymes that function to hydrolyze cyclic nucleotides to their corresponding 5' monophosphates. Their unique biochemical properties have been applied in treating Pulmonary Arterial Hypertension (PAH).
Among the PDE5 inhibitors, sildenafil (Revatio) stands out as a competitive and selective inhibitor. It operates by elevating cellular levels of cGMP and augmenting signaling through the cGMP-PKG pathway, promoting vasodilation. Upon oral...

Endothelins (ETs) are potent vasoactive peptides critical in the human body's various physiological and pathological processes. One of the most promising therapeutic strategies for treating pulmonary arterial hypertension (PAH) involves counteracting the effects of these endothelins using a class of drugs known as endothelin receptor antagonists.
ETs are synthesized through a complex sequence of enzymatic steps, primarily involving an enzyme referred to as endothelin-converting enzyme...

Prostacyclin receptor agonists are a class of therapeutic agents integral to managing pulmonary arterial hypertension (PAH). These drugs operate by mimicking the action of prostaglandin I2, or PGI2, a naturally occurring compound in the body.
These agonists bind to the IPR receptor situated on the plasma membrane of the pulmonary artery smooth muscle cells. This binding triggers a cascade of reactions known as the GS-AC-cAMP-PKA pathway. This pathway results in the relaxation of smooth muscle...

Proteins can form homomeric complexes with another unit of the same protein or heteromeric complexes with different types.  Most protein complexes self-assemble spontaneously via ordered pathways, while some proteins need assembly factors that guide their proper assembly. Despite the crowded intracellular environment, proteins usually interact with their correct partners and form functional complexes.
Many viruses self-assemble into a fully functional unit using the infected host cell to...

Groups of proteins may form a complex where each protein in this complex has a different role in the overall execution of the complex’s function. Often some of the proteins in the complex can be replaced by a closely related variant to give a complex that contains many of the same components yet is functionally distinct.
The SCF ubiquitin ligase is a protein complex of five individual proteins. This complex attaches ubiquitin to other target proteins to mark them for degradation. In order...

A type of Lewis acid-base chemistry involves the formation of a complex ion (or a coordination complex) comprising a central atom, typically a transition metal cation, surrounded by ions or molecules called ligands. These ligands can be neutral molecules like H2O or NH3, or ions such as CN− or OH−. Often, the ligands act as Lewis bases, donating a pair of electrons to the central atom. These types of Lewis acid-base reactions are examples of a broad subdiscipline called coordination...