Is melanopsin expressed in PACAP-containing retinal ganglion cells of the human retinohypothalamic tract?
Given the expression of melanopsin in PACAP-containing RGCs of the human RHT, this photoreceptor is a likely first base in the chain of events leading to photoentrainment of both normal and blind people.
Upper gastrointestinal endoscopy in patients with occult blood-positive stool and negative colonoscopy has a very low yield for significant lesions, not only from a therapeutic standpoint, but also for detection of malignant lesions. Prospective studies are needed to determine which specific groups of patients deserve further investigation.