Poly(ADP-ribose) polymerase 1 (PARP1) is a multifunctional protein involved in diverse cellular functions, notably DNA damage repair. Pharmacological inhibition of PARP1 has therapeutic benefits for various pathologies. Despite the increased use of PARP inhibitors, challenges persist in achieving PARP1 selectivity and effective blood-brain barrier (BBB) penetration. The development of a PARP1-specific positron emission tomography (PET) radioligand is crucial for understanding disease biology and performing target occupancy studies, which may aid in the development of PARP1-specific inhibitors. In this study, we leverage the recently identified PARP1 inhibitor, AZD9574, to introduce the design and development of its ¹⁸F-isotopologue ([¹⁸F]AZD9574). Our comprehensive approach, encompassing pharmacological, cellular, autoradiographic, and in vivo PET imaging evaluations in non-human primates, demonstrates the capacity of [¹⁸F]AZD9574 to specifically bind to PARP1 and to successfully penetrate the BBB. These findings position [¹⁸F]AZD9574 as a viable molecular imaging tool, poised to facilitate the exploration of pathophysiological changes in PARP1 tissue abundance across various diseases.

Nursemaid’s elbow is a radial head subluxation caused by axial traction on the extended arm while the forearm is pronated, allowing for slippage of the radial head. A 2-year-old boy presented with pain, swelling and reduced range of movement of the right elbow for 4 days. The mother noted that the child was moving the right upper limb less often and there was tenderness over the right elbow. X-ray of the right elbow showed subluxation of the elbow joint with no obvious fracture. A trial of conservative management was decided upon and the patient was placed on a right elbow backslab with the right forearm in a supine position. On follow-up, there was no swelling, tenderness or neurological deficit noted. A repeate x-ray revealed normal findings.

Heel pain is a common presentation at a primary care setting. The majority of these cases are benign and self limiting in nature. Common differential diagnoses include plantar fasciitis and peroneal muscle sprains. However, certain conditions—if undetected early—may cause significant morbidity to the patient. A high index of suspicion and early referral for further investigations are needed to prevent long-term morbidities.