Memory,anticipation, action – working with Troy D. Zars

Abstract

We present here our reflections on the scientific work of the late Troy D. Zars (1967 – 2018), on what it was like to work with him, and what it means to us. A common theme running through his work is that memory systems are not for replaying the past. Rather, they are forward-looking systems, providing whatever guidance past experience has to offer for anticipating the outcome of future actions. And in situations where no such guidance is available trying things out is the best option. Working with Troy was inspiring precisely because of the optimism inherent in this concept and that he himself embodied. Our reflections highlight what this means to us as his former mentors, colleagues, and mentees, respectively, and what it might mean for the future of neurogenetics.     

Spontaneous OHSS in a Young Adolescent: A Diagnostic Dilemma

The Journal of Obstetrics and Gynecology of India -     

Mast cell corticotropin-releasing factor subtype 2 suppresses mast cell degranulation and limits the severity of anaphylaxis and stress-induced intestinal permeability

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Human Organic Cation Transporters 1 (SLC22A1), 2 (SLC22A2), and 3 (SLC22A3) as Disposition Pathways for Fluoroquinolone Antimicrobials

Fluoroquinolones (FQs) are important antimicrobials that exhibit activity against a wide range of bacterial pathogens and excellent tissue permeation. They exist as charged molecules in biological fluids, and thus, their disposition depends heavily on active transport and facilitative diffusion. A recent review of the clinical literature indicated that tubular secretion and reabsorption are major determinants of their half-life in plasma, efficacy, and drug-drug interactions. In particular, reported in vivo interactions between FQs and cationic drugs affecting renal clearance implicated organic cation transporters (OCTs). In this study, 13 FQs, ciprofloxacin, enoxacin, fleroxacin, gatifloxacin, levofloxacin, lomefloxacin, moxifloxacin, norfloxacin, ofloxacin, pefloxacin, prulifloxacin, rufloxacin, and sparfloxacin, were screened for their ability to inhibit transport activity of human OCT1 (hOCT1) (SLC22A1), hOCT2 (SLC22A2), and hOCT3 (SLC22A3). All, with the exception of enoxacin, significantly inhibited hOCT1-mediated uptake under initial test conditions. None of the FQs inhibited hOCT2, and only moxifloxacin inhibited hOCT3 (∼30%), even at a 1,000-fold excess. Gatifloxacin, moxifloxacin, prulifloxacin, and sparfloxacin were determined to be competitive inhibitors of hOCT1. Inhibition constants (K_i) were estimated to be 250 ± 18 μM, 161 ± 19 μM, 136 ± 33 μM, and 94 ± 8 μM, respectively. Moxifloxacin competitively inhibited hOCT3-mediated uptake, with a K_i value of 1,598 ± 146 μM. Despite expression in enterocytes (luminal), hepatocytes (sinusoidal), and proximal tubule cells (basolateral), hOCT3 does not appear to contribute significantly to FQ disposition. However, hOCT1 in the sinusoidal membrane of hepatocytes, and potentially the basolateral membrane of proximal tubule cells, is likely to play a role in the disposition of these antimicrobial agents.