The impact of altered amino acid metabolism on cancer progression is not fully understood. We hypothesized that a metabolic transcriptome shift during metastatic evolution is crucial for brain metastasis. Here we report a powerful impact in this setting caused by epigenetic upregulation of glutamate decarboxylase 1 (GAD1), a regulator of the GABA neurotransmitter metabolic pathway. In cell-based culture and brain metastasis models, we found that downegulation of the DNA methyltransferase DNMT1 induced by the brain microenvironment-derived clusterin resulted in decreased GAD1 promoter methylation and subsequent upregulation of GAD1 expression in brain metastatic tumor cells. In a system to dynamically visualize cellular metabolic responses mediated by GAD1, we monitored the cytosolic NADH:NAD+ equilibrium in tumor cells. Reducing GAD1 in metastatic cells by primary glia cell co-culture abolished the capacity of metastatic cells to utilize extracellular glutamine, leading to cytosolic accumulation of NADH and increased oxidative status. Similarly, genetic or pharmacological disruption of the GABA metabolic pathway decreased the incidence of brain metastasis in vivo. Taken together, our results show how epigenetic changes in GAD1 expression alter local glutamate metabolism in the brain metastatic microenvironment, contributing to a metabolic adaption that facilitates metastasis outgrowth in that setting.

A Rh-catalyzed formal [4 + 1]-cycloaddition approach toward spirooxindole cyclopentenones is described. The diastereoselective cyclopropanation of vinyl ketenes with diazooxindoles as C1 synthons initiated a relatively mild formal [1,3]-migration of an intermediate cyclopropyl ketene to provide spirooxindoles in good to excellent yields (36-99%).

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Background: Comparative outcome studies investigating internal Double-J (DJ) and externalized stents have primarily been performed for open and laparoscopic pyeloplasty, with a paucity of literature surrounding outcomes in robot-assisted laparoscopic pyeloplasty (RALP). Furthermore, outcomes of a modified external stent inserted into the renal pelvis, termed cutaneous pyeloureteral (CPU) stent, remain unexamined. This study investigates outcomes of DJ and CPU stents as methods of trans-anastomotic drainage. Materials and Methods: A retrospective analysis identified pediatric patients who underwent RALP between December 2007 and January 2020 at a single tertiary center, where CPU stents were introduced in June 2012. Operative success was defined as improved or stable hydronephrosis without subsequent redo pyeloplasty. Secondary outcomes included stent reinsertion, anesthesia requirements, opioid administration, urinary tract infection (UTI), and bladder spasms. Results: A total of 103 pediatric RALP procedures were analyzed (DJ = 70, CPU = 33). Operative success (DJ = 95.7%, CPU = 100%, p = 0.55), Society for Fetal Urology (SFU) grade improvement, and length of stay were comparable. Accidental stent expulsion was only seen with CPU stents (9%; p = 0.03). Intracorporeal stent migration also occurred more frequently in CPU stents (DJ = 3%, CPU = 15%, p = 0.03). Stent reinsertion, when needed, used a DJ stent with rates of 4% and 9% for DJ and CPU stents, respectively ( p = 0.38). DJ stents were removed at a later postoperative day (DJ = 45.2 -25.0, CPU = 8.3 -4.2; p < 0.001) with increased general anesthesia (DJ = 99%, CPU = 3%; p < 0.001) and intravenous (IV) opioid (DJ = 27%, CPU = 9%; p = 0.04) requirements. Finally, DJ stents had nonsignificant increased rates of UTI (DJ = 17%, CPU = 3%, p = 0.06) and bladder spasms necessitating postoperative medication (DJ = 26%, CPU = 9%, p = 0.07). Conclusions: DJ and CPU stents display equivalent success rates in pediatric RALP and similar stent reinsertion rates. Appreciable differences can inform stent selection, including higher general anesthesia requirements and IV opioid administration among DJ stents and a higher incidence of accidental stent expulsion among CPU stents. In addition, DJ stents were associated with nonsignificant increased rates of UTI and bladder spasm necessitating medication.

Objectives: Determine whether preoperative dietary prehabilitation with a low-fat, high-fiber diet reverses the impact of Western diet (WD) on the intestinal microbiota and improves postoperative survival Background: We have previously demonstrated that WD fed mice subjected to an otherwise recoverable surgical injury (30% hepatectomy), antibiotics, and a short period of starvation demonstrate reduced survival (29%) compared to mice fed a low-fat, high-fiber standard chow (SD) (100%). Methods: Mice were subjected to 6 weeks of a WD and underwent dietary pre-habilitation (3 days vs 7 days) with a SD prior to exposure to antibiotics, starvation, and surgery. 16S rRNA gene sequencing was utilized to determine microbiota composition. Mass spectrometry measured short chain fatty acids and functional prediction from 16S gene amplicons were utilized to determine microbiota function. Results: As early as 24 hours, dietary prehabilitation of WD mice resulted in restoration of bacterial composition of the stool microbiota, transitioning from Firmicutes dominant to Bacteroidetes dominant. However, during this early pre-habilitation (ie, 3 days), stool butyrate per microbial biomass remained low and postoperative mortality remained unchanged from WD. Microbiota function demonstrated reduced butyrate contributing taxa as potentially responsible for failed recovery. In contrast, after 7 days of prehabilitation (7DP), there was greater restoration of butyrate producing taxa and survival after surgery improved (29% vs 79% vs 100%: WD vs 7DP vs SD, P < 0.001). Conclusions:The deleterious effects of WD on the gut microbiota can be restored after 7 days of dietary prehabilitation. Moreover, stool markers may define the readiness of the microbiome to withstand the process of surgery including exposure to antibiotics and short periods of starvation.