International Journal of Translational Medicine

G protein-coupled receptors (GPCRs) are the largest family of diverse receptors in eukaryotic organisms, playing a critical role in modulating human physiology. It therefore comes as no surprise that about 36% of all currently available drugs target this superfamily. When an agonist binds to a GPCR, it induces conformational changes in the receptor that allow it to interact with intracellular proteins. This interaction triggers downstream signaling cascades that alter the cell’s activity. GPCR signaling is complex, as GPCRs transmit signals through coupling with G proteins, arrestins, and numerous other intracellular effectors. Different ligands, receptor subtypes, and cellular environments can result in the activation of distinct signaling pathways. Biased signaling through GPCRs has emerged as a frontier area in pharmacological research efforts towards designing targeted therapeutic interventions and enhancing drug efficacy and safety. This review presents the types of bias associated with GPCRs and the mechanisms underlying biased signaling. Examples of biased ligands and their therapeutic implications will be discussed. In addition, the inherent challenges in measuring signaling bias, and especially the translational gap between in vitro and in vivo assays and clinical outcomes, will be outlined.

Pancreatic ductal adenocarcinoma (PDAC) is one of the most lethal cancers, with poor survival even after surgical resection. Clinical stages include resectable (R-PDAC), borderline resectable (BR-PDAC), locally advanced, and metastatic disease. Neoadjuvant therapy (NAT)—chemotherapy or chemoradiotherapy before surgery—has emerged as a promising strategy to improve outcomes by increasing margin-negative resection rates and enhancing overall survival. For R-PDAC, surgery followed by adjuvant chemotherapy remains the standard, but NAT may be considered in high-risk patients, such as those with severe pain, elevated CA 19-9, or large tumors. For BR-PDAC, NAT is the primary approach, significantly increasing R0 resection rates and prolonging survival. Common regimens include mFOLFIRINOX and gemcitabine-based combinations. NAT also carries risks, including disease progression during therapy, loss of resectability, and uncertainty in evaluating response. Current tools, such as imaging and CA 19-9, offer limited predictive value. The role of NAT in R-PDAC remains under debate, while its benefits in BR-PDAC are more established. This review summarizes current evidence and guidelines on NAT in PDAC, with a focus on treatment strategies, patient selection, and emerging approaches.

Background: Terminal ileum inflammation and surgical resections impair absorption of vitamin B12 and D in patients with Crohn’s disease (CD) and Ulcerative Colitis (UC). We assessed differences in subclinical deficiencies of vitamin B12 (<350 pg/mL) or D (<50 nmol/L), by lesion localization (namely non-ileal CD, ileal CD, and UC) and surgical resection status (namely no resection, non-ileal small bowel resections, ileocecal resections, and colonic resections) in CD and UC patients. Methods: We analyzed data from 571 patients (17–93 years), with UC (51%) and CD (49%, including 47 non-ileal (8%), 244 ileal-CD (46%)) managed at the University of Missouri Health Care System (Jan 2017–April 2022). Results: Prevalence of vitamin B12 and vitamin D deficiencies was 19% and 83%, respectively. Prevalence of resection was 26%, including 5% with non-ileal small bowel resections, 11% with ileocecal resections, and 10% with colonic resections. CD with ileal involvement was associated with a 3-fold elevated risk of B12 deficiency (p = 0.004), but not vitamin D. Ileocecal resections were associated with a >3-fold increase in both B12 deficiency (OR = 3.53, p = 0.001) and D deficiency (OR = 3.35, p = 0.044). Conclusions: CD patients with ileal involvement and ileocecal resections have an elevated risk of vitamin B12 and D deficiency, and may benefit from adjunctive supplementation.