Siderophores: A Case Study in Translational Chemical Biology.

Siderophores are metal-binding secondary metabolites that assist in iron homeostasis and have been of interest to the scientific community for the last half century. Foundational siderophore research has enabled several translational applications including siderophore-antibiotic and siderophore-peptide conjugates, identification of new antimicrobial targets, advances in disease imaging, and novel therapeutics. This review aims to connect the basic science research (biosynthesis, cellular uptake, gene regulation, and effects on homeostasis) of well-known siderophores with the successive translational application that results. Intertwined throughout are connections to the career of Christopher T. Walsh, his impact on the field of chemical biology, and the legacy of his trainees who continue to innovate.

Mild Photochemical Reduction of Alkenes and Heterocycles via Thiol-Mediated Formate Activation.

The reduction of alkenes to their respective alkanes is one of the most important transformations in organic chemistry, given the abundance of natural and commercial olefins. Metal-catalyzed hydrogenation is the most common way to reduce alkenes; however, the use of H2 gas in combination with the precious metals required for these conditions can be impractical, dangerous, and expensive. More complex substrates often require extremely high pressures of H2, further emphasizing the safety concerns associated with these hydrogenation reactions. Here we report a safe, cheap, and practical photochemical alkene reduction using a readily available organophotocatalyst, catalytic thiol, and formate. These conditions reduce a variety of di-, tri-, and tetra-substituted alkenes in good yield as well as dearomatize pharmaceutically relevant heterocycles to generate sp3-rich isosteres of benzofurans and indoles. These formal-hydrogenation conditions tolerate a broad range of functionalities that would otherwise be sensitive to typical hydrogenations and are likely to be important for industry applications.

Ketamine's rapid antisuicidal effects are not attenuated by Buprenorphine.

Ketamine's rapid antisuicidal action has gathered significant clinical interest in treatment of depression though concerns exist that its actions occur through the Opioid pathway. A recent study additionally reported that Naltrexone blocks antisuicidal effects of Ketamine suggesting that its antisuicidal effects are also due to opioid mechanisms. We present a case of treatment refractory depression with recent suicide attempt and active suicidal ideations who was on an Opioid partial agonist, Buprenorphine, for management of pain. Patient responded to a trial of IV ketamine treatment with rapid improvement in suicidal thoughts. Patient's suicidal ideations decreased after first Ketamine treatment and resolved after second treatment while maintained on Buprenorphine. Our finding shows that Buprenorphine does not block Ketamine's effects on suicidal ideations and therefore Ketamine treatment could be provided safely in controlled environment to those with substance use disorders or with chronic pain while being maintained on Buprenorphine. Additionally, our case suggests that non-Opioid mechanisms may be involved in Ketamine's antidepressant effects and its response to suicidal ideations in those on Opioid partial agonists.

Successful use of carbamazepine in a patient with drug rash with eosinophilia and systemic symptoms.

Drug rash with eosinophilia and systemic symptoms (DRESS) is a serious adverse drug reaction with a high mortality rate. Discontinuation of the causative agent is the primary treatment. History of DRESS may put patients at higher risk of future episodes; however, cross-reactivity between various medications is not well established. An 18-year-old African American male with a history of bipolar I disorder with psychotic features was admitted for mania on his home dose of divalproex. After 1 week, olanzapine was added for refractory symptoms, but due to elevated creatinine phosphokinase (CPK), it was subsequently discontinued, and he was started on lorazepam and lithium. One week later, the patient was transferred to the intensive care unit with elevated CPK, fever, thrombocytopenia, elevated serum creatinine, hypotension, diarrhea, mild rigidity, bilateral inducible ankle clonus, and a rash. All medications were discontinued except for lorazepam. The skin pathology report was consistent with a drug eruption, and he was started on prednisone. Given continued symptoms of mania, carbamazepine was initiated. After clinical and laboratory improvement, the patient was discharged on hospital day 59 with instructions to continue carbamazepine and lorazepam. A MEDLINE search revealed no published case reports of the successful use of carbamazepine in a patient with a history of DRESS. Information regarding cross-reactivity between medications is limited primarily to aromatic antiepileptics. In our case report, carbamazepine was successfully used in a patient with a recent episode of DRESS during olanzapine, lithium, and valproate use.

bNAber: database of broadly neutralizing HIV antibodies.

The discovery of broadly neutralizing antibodies (bNAbs) has provided an enormous impetus to the HIV vaccine research and to entire immunology. The bNAber database at http://bNAber.org provides open, user-friendly access to detailed data on the rapidly growing list of HIV bNAbs, including neutralization profiles, sequences and three-dimensional structures (when available). It also provides an extensive list of visualization and analysis tools, such as heatmaps to analyse neutralization data as well as structure and sequence viewers to correlate bNAbs properties with structural and sequence features of individual antibodies. The goal of the bNAber database is to enable researchers in this field to easily compare and analyse available information on bNAbs thereby supporting efforts to design an effective vaccine for HIV/AIDS. The bNAber database not only provides easy access to data that currently is scattered in the Supplementary Materials sections of individual papers, but also contributes to the development of general standards of data that have to be presented with the discovery of new bNAbs and a universal mechanism of how such data can be shared.

Asymmetrical effects of adaptation to left- and right-shifting prisms depends on pre-existing attentional biases.

Proposals that adaptation with left-shifting prisms induces neglect-like symptoms in normal individuals rely on a dissociation between the postadaptation performance of individuals trained with left- versus right-shifting prisms (e.g., Colent, Pisella, & Rossetti, 2000). A potential problem with this evidence is that normal young adults have an a priori leftward bias (e.g., Jewell & McCourt, 2000). In Experiment 1, we compared the line bisection performance of young adults to that of aged adults, who as a group may lack a leftward bias in line bisection. Participants trained with both left- and right-shifting prisms. Consistent with our hypothesis, while young adults demonstrated aftereffects for left, but not right prisms, aged adults demonstrated reliable aftereffects for both prisms. In Experiment 2, we recruited a larger sample of young adults, some of whom were right-biased at baseline. We observed an interaction between baseline bias and prism-shift, consistent with the results of Experiment 1: Left-biased individuals showed a reduced aftereffect when training with right-shifting prisms and right-biased individuals showed a reduced aftereffect when training with left-shifting prisms. These results suggest that previous failures to find generalizable aftereffects with right-shifting prisms may be driven by participants' baseline biases rather than specific effects of the prism itself.