Human ABC and SLC Transporters: The Culprit Responsible for Unspecific PSMA-617 Uptake?

[177Lu]Lu-PSMA-617 has recently been successfully approved by the FDA, the MHRA, Health Canada and the EMA as Pluvicto®. However, salivary gland (SG) and kidney toxicities account for its main dose-limiting side-effects, while its corresponding uptake and retention mechanisms still remain elusive. Recently, the presence of different ATP-binding cassette (ABC) transporters, such as human breast cancer resistance proteins (BCRP), multidrug resistance proteins (MDR1), multidrug-resistance-related proteins (MRP1, MRP4) and solute cassette (SLC) transporters, such as multidrug and toxin extrusion proteins (MATE1, MATE2-K), organic anion transporters (OAT1, OAT2v1, OAT3, OAT4) and peptide transporters (PEPT2), has been verified at different abundances in human SGs and kidneys. Therefore, our aim was to assess whether [177Lu]Lu-PSMA-617 and [225Ac]Ac-PSMA-617 are substrates of these ABC and SLC transporters. For in vitro studies, the novel isotopologue ([α,β-3H]Nal)Lu-PSMA-617 was used in cell lines or vesicles expressing the aforementioned human ABC and SLC transporters for inhibition and uptake studies, respectively. The corresponding probe substrates and reference inhibitors were used as controls. Our results indicate that [177Lu]Lu-PSMA-617 and [225Ac]Ac-PSMA-617 are neither inhibitors nor substrates of the examined transporters. Therefore, our results show that human ABC and SLC transporters play no central role in the uptake and retention of [177Lu]Lu-PSMA-617 and [225Ac]Ac-PSMA-617 in the SGs and kidneys nor in the observed toxicities.

Zn2+ detection of a benzimidazole 8-aminoquinoline fluorescent sensor by inhibited tautomerization

The sensor shows a high selectivity and sensitivity toward zinc cations, accompanied by a distinct green fluorescence emission.

Prolonged Qt Interval after Fexofenadine Overdose in the Presence of Hypokalemia and Hypocalcaemia

A 23-year-old healthy woman was admitted to our emergency department because of syncope and unconsciousness. She had taken 20 tablets of fexofenadine (total 2400 mg) and 9 tablets of furosemide (total 360 mg) for suicide. The electrocardiogram demonstrated bradycardia (48/min) and markedly prolonged QTc interval (684 msec). Endotracheal intubation and nasogastric tube insertion were performed. Gastric lavage was implemented and activated charcoal was given. A transient pacemaker was implanted. Hypokalemia and hypocalcaemia were also present and the electrolyte disturbances were corrected. The heart rate and QTc interval returned to normal limits after treatment. She stayed in our hospital for seven days. She recovered completely and ventricular arrhythmia was not seen during the hospitalization period.

[Gastrointestinal hemorrhage due to traumatic superior mesenteric artery aneurysm (case report)]

We report the case of a 21-year-old male patient with superior mesenteric artery aneurysm due to missed arterial injuries, its complications of enteric fistula and results of surgical treatment. The aneurysm was excised, enteric fistula was closed and aorta-mesenteric bypass using saphenous vein graft was performed. The hemorrhage became masked because of the tamponade in the mesentery during penetrating abdominal injury and initial surgery, and the late complication of false aneurysm came on the scene in follow up. Aorta-mesenteric bypass by a transmesenteric approach provides successful result in surgical treatment of superior mesenteric artery aneurysm.