Overview of serotonin syndrome.

Background: Serotonin syndrome (SS) is a rare and potentially life-threatening toxic state caused by an adverse drug reaction that leads to excessive central and peripheral serotonergic activity. This excessive serotonin hyperstimulation may be secondary to 1 standard therapeutic dose of a single agent, inadvertent interactions between various drugs, intentionally or unintentionally excessive use of particular drugs, deliberate self-harm, or recreational use of certain drugs. This review article serves as an overview of the epidemiology, pathophysiology, clinical features, diagnosis, differential diagnosis, management, and prevention of SS.

Osteoblastic expansion induced by parathyroid hormone receptor signaling in murine osteocytes is not sufficient to increase hematopoietic stem cells.

Microenvironmental expansion of hematopoietic stem cells (HSCs) is induced by treatment with parathyroid hormone (PTH) or activation of the PTH receptor (PTH1R) in osteoblastic cells; however, the osteoblastic subset mediating this action of PTH is unknown. Osteocytes are terminally differentiated osteoblasts embedded in mineralized bone matrix but are connected with the BM. Activation of PTH1R in osteocytes increases osteoblastic number and bone mass.