The feasibility and safety of laparoscopic transcystic common bile duct exploration after prior gastrectomy.

The increased incidence of gallstones can be linked to previous gastrectomy (PG). However, the success rate of endoscopic retrograde cholangiopan-creatography after gastrectomy has significantly reduced. In such cases, laparoscopic transcystic common bile duct exploration (LTCBDE) may be an alternative. In this study, LTCBDE was evaluated for its safety and feasibility in patients with PG. We retrospectively evaluated 300 patients who underwent LTCBDE between January 2015 and June 2023. The subjects were divided into 2 groups according to their PG status: PG group and No-PG group. The perioperative data from the 2 groups were compared. The operation time in the PG group was longer than that in the No-PG group (184.69 ±â€…20.28 minutes vs 152.19 ±â€…26.37 minutes, P < .01). There was no significant difference in intraoperative blood loss (61.19 ±â€…41.65 mL vs 50.83 ±â€…30.47 mL, P = .087), postoperative hospital stay (6.36 ±â€…1.94 days vs 5.94 ±â€…1.36 days, P = .125), total complication rate (18.6 % vs 14.1 %, P = .382), stone clearance rate (93.2 % vs 96.3 %, P = .303), stone recurrence rate (3.4 % vs 1.7 %, P = .395), and conversion rate (6.8 % vs 7.0 %, P = .941) between the 2 groups. No deaths occurred in either groups. A history of gastrectomy may not affect the feasibility and safety of LTCBDE, because its perioperative results are comparable to those of patients with a history of No-gastrectomy.

Development of a high-throughput dual-stream liquid chromatography-tandem mass spectrometry method to screen for inhibitors of glutamate carboxypeptidase II.

RATIONALE: Glutamate carboxypeptidase II (GCPII) catalyzes the hydrolysis of N-acetylaspartylglutamate (NAAG) to yield glutamate (Glu) and N-acetylaspartate (NAA). Inhibition of GCPII has been shown to remediate the neurotoxicity of excess Glu in a variety of cell and animal disease models. A robust high-throughput liquid chromatography-tandem mass spectrometry (LC/MS/MS) method was needed to quantify GCPII enzymatic activity in a biochemical high-throughput screening assay. METHODS: A dual-stream LC/MS/MS method was developed. Two parallel eluent streams ran identical HILIC gradient methods on BEH-Amide (2 × 30 mm) columns. Each LC channel was run independently, and the cycle time was 2 min per channel. Overall throughput was 1 min per sample for the dual-channel integrated system. Multiply injected acquisition files were split during data review, and batch metadata were automatically paired with raw data during the review process. RESULTS: Two LC sorbents, BEH-Amide and Penta-HILIC, were tested to separate the NAAG cleavage product Glu from isobaric interference and ion suppressants in the bioassay matrix. Early elution of NAAG and NAA on BEH-Amide allowed interfering species to be diverted to waste. The limit of quantification was 0.1 pmol for Glu. The Z-factor of this assay averaged 0.85. Over 36 000 compounds were screened using this method. CONCLUSIONS: A fast gradient dual-stream LC/MS/MS method for Glu quantification in GCPII biochemical screening assay samples was developed and validated. HILIC separation chemistry offers robust performance and unique selectivity for targeted positive mode quantification of Glu, NAA, and NAAG.

Lactate drives CD38 signaling to promote Epithelial-Mesenchymal Transition through Snail induction in non-small cell lung cancer cells.

CD38 is the main NADase in mammalian cells. It regulates the homeostasis of nicotinamide adenine dinucleotide (NAD+) and extracellular nucleotides. Its function plays an important role in infection and aging. However, its potential functions in tumor cells have not been fully elucidated. In the present study, we demonstrated that lactate, which is derived from tumor metabolism remodeling, upregulates the expression of CD38 through OXPHOS-driven Hippo-TAZ pathway. The highly expressed CD38 converts NAD + to adenosine through the CD203a/CD73 complex and adenosine binds and activates its receptor A2AR, inducing the expression of Snail and promoting the invasion and metastasis of lung cancer cells. This finding elucidates a new perspective on the interplay between NAD + metabolism and glycolysis in tumor development.

Enhanced corrosion of 2205 duplex stainless steel by Acetobacter aceti through synergistic electron transfer and organic acids acceleration.

Acetobacter aceti is a microbe that produces corrosive organic acids, causing severe corrosion of industrial equipment. Previous studies have focused on the organic acid corrosion of A. aceti, but neglected the possibility that it has electron transfer corrosion. This study found that electron transfer and organic acids can synergistically promote the corrosion of 2205 duplex stainless steel (DSS). Electrochemical measurement results showed that corrosion of 2205 DSS was more severe in the presence of A. aceti. Surface analysis indicated a thick biofilm formed on the steel surface, with low pH and dissolved oxygen concentrations under the biofilm. Corrosion intensified when A. aceti lacked a carbon source, suggesting that A. aceti can corrode metals by using metallic substrates as electron donors, in addition to its acidic by-products.

Fragment-Based Screening Identifies New Quinazolinone-Based Inositol Hexakisphosphate Kinase (IP6K) Inhibitors.

A high-throughput fragment-based screen has been employed to discover a series of quinazolinone inositol hexakisphosphate kinase (IP6K) inhibitors. IP6Ks have been studied for their role in glucose homeostasis, metabolic disease, fatty liver disease, chronic kidney disease, blood coagulation, neurological development, and psychiatric disease. IP6Ks phosphorylate inositol hexakisphosphate (IP6) to form pyrophosphate 5-diphospho-1,2,3,4,6-pentakisphosphate (IP7). Molecular docking studies and investigation of structure-activity relationships around the quinazolinone core resulted in compounds with submicromolar potency and interesting selectivity for IP6K1 versus the closely related IP6K2 and IP6K3 isoforms.

Drug-induced lactate confers ferroptosis resistance via p38-SGK1-NEDD4L-dependent upregulation of GPX4 in NSCLC cells.

Ferroptosis is a newly defined non-apoptotic programmed cell death resulting from the accumulation of lipid peroxides. Whether ferroptosis plays any role in chemotherapy remains to be established. Here, we reported that ferroptosis represents a part of the chemotherapeutic drug etoposide-induced cell death response in Small Cell Lung Cancer (SCLC) cells and adaptive signaling molecule lactate protects Non-Small Cell Lung Cancer (NSCLC) from etoposide-induced ferroptosis. Lactate derived from metabolic reprogramming increases the expression of glutathione peroxidase 4 (GPX4) to promote ferroptosis resistance in NSCLC. Furthermore, we identified E3-ubiquitin ligase NEDD4L as a major regulator of GPX4 stability. Mechanistically, Lactate increases mitochondrial ROS generation and drives activation of the p38-SGK1 pathway, which attenuates the interaction of NEDD4L with GPX4 and subsequent ubiquitination and degradation of GPX4. Our data implicated the role of ferroptosis in chemotherapeutic resistance and identified a novel post-translational regulatory mechanism for the key Ferroptosis mediator GPX4.

Tribological behaviors of laser textured surface under different lubrication conditions for rotary compressor.

Tribological behaviors of laser textured surface with elliptical dimples were experimentally compared with that of the smooth one under different lubrication conditions, including the poor-oil, rich-oil and dry lubrication. The lubrication regime was analyzed with the increasing operating load by ring-on-ring tribological tests. Finally, the performance impact of rolling piston rotary compressor with textures fabricated on the thrust surfaces was investigated. Results show that the tribological improvement strongly depends on lubrication condition. With the increase of applied loads under rich-oil and poor-oil lubrication, the effect of micro dimple promotes the critical load transforming lubrication regime, and expands the range of hydrodynamic lubrication, meanwhile maintains a similar minimum of friction coefficient as the smooth surface but enhances wear resistance. However, it is reverse to increase the friction coefficient and surface wear for the textured surfaces under dry lubrication. The compressor performance can be improved significantly by laser surface texturing with a 2% reduction of friction power consumption and a 2.5% enhancement of energy efficiency ratio.

A physiology-based trigger score to guide perioperative transfusion of allogeneic red blood cells: A multicentre randomised controlled trial.

BACKGROUND: Restrictive blood transfusion is recommended by major guidelines for perioperative management, but requires objective assessment at 7-10 g/dl haemoglobin (Hb). A scoring system that considers the physiological needs of the heart may simply the practice and reduce transfusion. METHODS: Patients (14-65 years of age) undergoing non-cardiac surgery were randomised at a 1:1 ratio to a control group versus a Perioperative Transfusion Trigger Score (POTTS) group. POTTS (maximum of 10) was calculated as 6 plus the following: adrenaline infusion rate (0 for no infusion, 1 for ≤0.05 µg·kg-1 ·min-1 , and 2 for higher rate), FiO2 to keep SpO2 at ≥95% (0 for ≤35%, 1 for 36%-50%, and 2 for higher), core temperature (0 for <38°C, 1 for 38-40°C, and 2 for higher), and angina history (0 for no, 1 for exertional, and 2 for resting). Transfusion is indicated when actual Hb is lower than the calculated POTTS in individual patients. Transfusion in the control group was based on the 2012 American Association for Blood Banks (AABB) guideline. The primary outcome was the proportion of the patients requiring transfusion of allogeneic red blood cells (RBCs) during the perioperative period (until discharge from hospital), as assessed in the intention-to-treat (ITT) population (all randomised subjects). RESULT: A total of 864 patients (mean age 44.4 years, 244 men and 620 women) were enrolled from December 2017 to January 2021 (433 in the control and 431 in the POTTS group). Baseline Hb was 9.2 ± 1.8 and 9.2 ± 1.7 g/dl in the control and POTTS groups, respectively. In the ITT analysis, the proportion of the patients receiving allogeneic RBCs was 43.9% (190/433) in the control group versus 36.9% (159/431) in the POTTS group (p = 0.036). Lower rate of allogeneic RBCs transfusion in the POTTS group was also evident in the per-protocol analysis (42.8% vs. 35.5%, p = 0.030). Transfusion volume was 4.0 (2.0, 6.0) and 3.5 (2.0, 5.5) units (200 ml/unit) in the control and POTTS groups, respectively (p = 0.25). The rate of severe postoperative complications (Clavien-Dindo grade IIIa and higher) was 3.9% in the control group versus 1.2% in the POTTS group (p = 0.010). CONCLUSION: Transfusion of allogeneic RBCs based on the POTTS was safe and reduced the transfusion requirement in patients undergoing non-cardiac surgery.

The pathogenesis of, and pharmacological treatment for, Canavan disease.

Canavan disease (CD) is an inherited leukodystrophy resulting from mutations in the gene encoding aspartoacylase (ASPA). ASPA is highly expressed in oligodendrocytes and catalyzes the cleavage of N-acetylaspartate (NAA) to produce aspartate and acetate. In this review, we examine the pathologies and clinical presentation in CD, the metabolism and transportation of NAA in the brain, and the hypothetical mechanisms whereby ASPA deficiency results in dysmyelination and a failure of normal brain development. We also discuss therapeutic options that could be used for the treatment of CD.

Lead Optimization to Advance Protease-Activated Receptor-1 Antagonists in Early Discovery.

Vorapaxar is an approved drug for the reduction of thrombotic cardiovascular events in patients with a history of myocardial infarction or with peripheral arterial disease. Subsequent to the discovery of Vorapaxar, medicinal chemistry efforts were continued to identify structurally differentiated leads. Toward this goal, extensive structure-activity relationship studies using a C-ring-truncated version of Vorapaxar culminated in the discovery of three leads, represented as 13, 14, and 23. Among these leads, compound 14 possessed favorable pharmacokinetic properties and an off-target profile, which supported additional profiling in an exploratory rat toxicology study.

High-Throughput Activity Assay for Screening Inhibitors of the SARS-CoV-2 Mac1 Macrodomain.

Macrodomains are a class of conserved ADP-ribosylhydrolases expressed by viruses of pandemic concern, including coronaviruses and alphaviruses. Viral macrodomains are critical for replication and virus-induced pathogenesis; therefore, these enzymes are a promising target for antiviral therapy. However, no potent or selective viral macrodomain inhibitors currently exist, in part due to the lack of a high-throughput assay for this class of enzymes. Here we developed a high-throughput ADP-ribosylhydrolase assay using the SARS-CoV-2 macrodomain Mac1. We performed a pilot screen that identified dasatinib and dihydralazine as ADP-ribosylhydrolase inhibitors. Importantly, dasatinib inhibits SARS-CoV-2 and MERS-CoV Mac1 but not the closest human homologue, MacroD2. Our study demonstrates the feasibility of identifying selective inhibitors based on ADP-ribosylhydrolase activity, paving the way for the screening of large compound libraries to identify improved macrodomain inhibitors and to explore their potential as antiviral therapies for SARS-CoV-2 and future viral threats.

High Throughput Screening Cascade To Identify Human Aspartate N-Acetyltransferase (ANAT) Inhibitors for Canavan Disease.

Canavan disease (CD) is a progressive, fatal neurological disorder that begins in infancy resulting from a mutation in aspartoacyclase (ASPA), an enzyme that catalyzes the deacetylation of N-acetyl aspartate (NAA) into acetate and aspartate. Increased NAA levels in the brains of affected children are one of the hallmarks of CD. Interestingly, genetic deletion of N-acetyltransferase-8-like (NAT8L), which encodes aspartate N-aceyltransferase (ANAT), an enzyme responsible for the synthesis of NAA from l-aspartate and acetyl-CoA, leads to normalization of NAA levels and improvement of symptoms in several genetically engineered mouse models of CD. Therefore, pharmacological inhibition of ANAT presents a promising therapeutic strategy for treating CD. Currently, however, there are no clinically viable ANAT inhibitors. Herein we describe the development of fluorescence-based high throughput screening (HTS) and radioactive-based orthogonal assays using recombinant human ANAT expressed in E. coli. In the fluorescence-based assay, ANAT activity was linear with respect to time of incubation up to 30 min and protein concentration up to 97.5 ng/µL with Km values for l-aspartate and acetyl-CoA of 237 µM and 11 µM, respectively. Using this optimized assay, we conducted a pilot screening of a 10 000-compound library. Hits from the fluorescence-based assay were subjected to an orthogonal radioactive-based assay using L-[U-14C] aspartate as a substrate. Two compounds were confirmed to have dose-dependent inhibition in both assays. Inhibitory kinetics studies of the most potent compound revealed an uncompetitive inhibitory mechanism with respect to l-aspartate and a noncompetitive inhibitory mechanism against acetyl-CoA. The screening cascade developed herein will enable large-scale compound library screening to identify novel ANAT inhibitors as leads for further medicinal chemistry optimization.

Urolithin A Inhibits Epithelial-Mesenchymal Transition in Lung Cancer Cells via P53-Mdm2-Snail Pathway.

PURPOSE: The epithelial-to-mesenchymal transition (EMT) is a fundamental process in tumor progression that endows cancer cells with migratory and invasive potential. Snail, a zinc finger transcriptional repressor, plays an important role in the induction of EMT by directly repressing the key epithelial marker E-cadherin. Here, we assessed the effect of urolithin A, a major metabolite from pomegranate ellagitannins, on Snail expression and EMT process. METHODS: The role of Snail in urolithin A-induced EMT inhibition in lung cancer cells was explored by wound healing assay and cell invasion assay. The qRT-PCR and CHX assay were performed to investigate how urolithin A regulates Snail expression. Immunoprecipitation assays were established to determine the effects of urolithin A in mdm2-Snail interaction. In addition, the expression of p53 was manipulated to explore its effect on the expression of mdm2 and Snail. RESULTS: The urolithin A dose-dependently upregulated epithelial marker and decreased mesenchymal markers in lung cancer cells. In addition, exposure to urolithin A decreased cell migratory and invasive capacity. We have further demonstrated that urolithin A inhibits lung cancer cell EMT by decreasing Snail protein expression and activity. Mechanistically, urolithin A disrupts the interaction of p53 and mdm2 which leads Snail ubiquitination and degradation. CONCLUSION: We conclude that urolithin A could inhibit EMT process by controlling mainly Snail expression. These results highlighted the role of pomegranate in regulation of EMT program in lung cancer.

Identification of Small-Molecule Inhibitors of Human Inositol Hexakisphosphate Kinases by High-Throughput Screening.

Inositol hexakisphosphate kinases (IP6Ks) catalyze pyrophosphorylation of inositol hexakisphosphate (IP6) into inositol 5-diphospho-1,2,3,4,6-pentakisphosphate (IP7), which is involved in numerous areas of cell physiology including glucose homeostasis, blood coagulation, and neurological development. Inhibition of IP6Ks may be effective for the treatment of Type II diabetes, obesity, metabolic complications, thrombosis, and psychiatric disorders. We performed a high-throughput screen (HTS) of 158 410 compounds for IP6K1 inhibitors using a previously developed ADP-Glo Max assay. Of these, 1206 compounds were found to inhibit IP6K1 kinase activity by more than 25%, representing a 0.8% hit rate. Structural clustering analysis of HTS-active compounds, which were confirmed in the dose-response testing using the same kinase assay, revealed diverse clusters that were feasible for future structure-activity relationship (SAR) optimization to potent IP6K inhibitors. Medicinal chemistry SAR efforts in three chemical series identified potent IP6K1 inhibitors which were further validated in an orthogonal LC-MS IP7 analysis. The effects of IP6K1 inhibitors on cellular IP7 levels were further confirmed and were found to correlate with cellular IP6K1 binding measured by a high-throughput cellular thermal shift assay (CETSA).

Membrane bound catechol-O-methytransferase is the dominant isoform for dopamine metabolism in PC12 cells and rat brain.

Impaired dopamine activity in the dorsolateral prefrontal cortex (DLPFC) is thought to contribute to cognitive deficits in diseases such as schizophrenia, attention deficit hyperactivity disorder (ADHD) and traumatic brain injury. Catechol-O-methyltransfease (COMT) metabolizes dopamine and is an important regulator of dopamine signaling in the DLPFC. In mammalian species, two isoforms of COMT protein, membrane-bound COMT (MB-COMT) and soluble COMT (S-COMT), are encoded by one COMT gene and expressed widely. While S-COMT is thought to play a dominant role in the peripheral tissues, MB-COMT is suggested to have a greater role in dopamine metabolism in the brain. However, whether a selective inhibitor for MB-COMT may effectively block dopamine metabolism remains unknown. We generated a knockout of MB-COMT in PC12 cells using CRISPR-cas9 technology to evaluate the effect of both MB and S-COMT on dopamine metabolism. Deletion of MB-COMT in PC12 cells significantly decreased homovanillic acid (HVA), completely depleted 3-methyoxytyramine (3-MT), and significantly increased 3,4-dihydroxyphenylacetic acid (DOPAC) levels. Comparison of the effect of a MB-COMT selective inhibitor LI-1141 on dopamine metabolism in wild type and MB-COMT knockout PC12 cells allowed us to confirm the selectivity of LI-1141 with respect to MB-COMT in cells. Under conditions in which LI-1141 was shown to inhibit only MB-COMT but not S-COMT, it effectively changed dopamine metabolites similar to the effect induced by tolcapone, a non-selective COMT inhibitor, suggesting that selective inhibition of MB-COMT will be effective in blocking dopamine metabolism, providing an attractive therapeutic approach in improving cognition for patients.

Resveratrol induces PD-L1 expression through snail-driven activation of Wnt pathway in lung cancer cells.

PURPOSE: Recent clinical trials with agents targeting immune checkpoint pathway have emerged as an important therapeutic approach for a broad range of cancer types. Resveratrol has been shown to possess cancer preventive and therapeutic effects and has potential to be chemotherapeutic agent/adjuvant. Here, we assessed the effect of resveratrol on immune checkpoint pathways. METHODS: The expression patterns of Wnt components and PD-L1 were examined by Western blot, Chromatin immunoprecipitation (ChIP) was used for analysis of DNA-protein interaction, the promoter activity was determined by luciferase reporter assay, apoptosis was analyzed by flow cytometry and the ability of the resveratrol to modulate T cell function was assessed in a co-culture system. RESULTS: Although the dose-, and cell-type dependent effects of resveratrol on PD-L1 expression have been reported, we show here that resveratrol dose-dependently upregulates PD-L1 expression at the range of pharmacologic-achievable concentrations in lung cancer cells and that is essential for suppression of T-cell-mediated immune response. We also found that Wnt pathway is critical for mediating resveratrol-induced PD-L1 upregulation. Mechanistically, resveratrol activates SirT1 deacetylase to deacetylate and stabilize transcriptional factor Snail. Snail in turn inhibits transcription of Axin2, which leads in disassembly of destruction complex and enhanced binding of ß-catenin/TCF to PD-L1 promoter. CONCLUSION: We conclude that resveratrol is capable to suppress anti-tumor immunity by controlling mainly PD-L1 expression. This finding will extend the understanding of resveratrol in regulation of tumor immunity and is relevant to the debate on resveratrol supplements for lung cancer patients.

Lactate-induced MRP1 expression contributes to metabolism-based etoposide resistance in non-small cell lung cancer cells.

BACKGROUND: Metabolic reprogramming contributes significantly to tumor development and is tightly linked to drug resistance. The chemotherapeutic agent etoposide (VP-16) has been used clinically in the treatment of lung cancer but possess different sensitivity and efficacy towards SCLC and NSCLC. Here, we assessed the impact of etoposide on glycolytic metabolism in SCLC and NSCLC cell lines and investigated the role of metabolic rewiring in mediating etoposide resistance. METHODS: glycolytic differences of drug-treated cancer cells were determined by extracellular acidification rate (ECAR), glucose consumption, lactate production and western blot. DNA damage was evaluated by the comet assay and western blot. Chemoresistant cancer cells were analyzed by viability, apoptosis and western blot. Chromatin immunoprecipitation (ChIP) was used for analysis of DNA-protein interaction. RESULTS: Here we showed that exposure to chemotherapeutic drug etoposide induces an exacerbation of ROS production which activates HIF-1α-mediated the metabolic reprogramming toward increased glycolysis and lactate production in non-small cell lung cancer (NSCLC). We identified lactic acidosis as the key that confers multidrug resistance through upregulation of multidrug resistance-associated protein 1 (MRP1, encoded by ABCC1), a member of ATP-binding cassette (ABC) transporter family. Mechanistically, lactic acid coordinates TGF-ß1/Snail and TAZ/AP-1 pathway to induce formation of Snail/TAZ/AP-1 complex at the MRP1/ABCC1 promoter. Induction of MRP1 expression inhibits genotoxic and apoptotic effects of chemotherapeutic drugs by increasing drug efflux. Furthermore, titration of lactic acid with NaHCO3 was sufficient to overcome resistance. CONCLUSIONS: The chemotherapeutic drug etoposide induces the shift toward aerobic glycolysis in the NSCLC rather than SCLC cell lines. The increased lactic acid in extracellular environment plays important role in etoposide resistance through upregulation of MRP expression. These data provide first evidence for the increased lactate production, upon drug treatment, contributes to adaptive resistance in NSCLC and reveal potential vulnerabilities of lactate metabolism and/or pathway suitable for therapeutic targeting. Video Abstract The chemotherapeutic drug etoposide induces metabolic reprogramming towards glycolysis in the NSCLC cells. The secreted lactic acid coordinates TGF-ß1/Snail and TAZ/AP-1 pathway to activate the expression of MRP1/ABCC1 protein, thus contributing to chemoresistance in NSCLC.

[Dexmedetomidine combined with protective lung ventilation strategy provides lung protection in patients undergoing radical resection of esophageal cancer with one-lung ventilation].

OBJECTIVE: To investigate the effect of dexmedetomidine combined with pulmonary protective ventilation against lung injury in patients undergoing surgeries for esophageal cancer with one-lung ventilation (OLV). METHODS: Forty patients with undergoing surgery for esophageal cancer with OLV were randomly divided into pulmonary protective ventilation strategy group (F group) and dexmedetomidine combined with protective ventilation strategy group (DF group; n=20). In F group, lung protective ventilation strategy during anesthesia was adopte, and in DF group, the patients received intravenous infusion of dexmedetomidine hydrochloride (0.3 µg · kg-1 ·h-1) during the surgery starting at 10 min before anesthesia induction in addition to protective ventilation strategy. Brachial artery blood was sampled before ventilation (T0), at 30 and 90 min after the start of OLV (T1 and T2, respectively) and at the end of the surgery (T3) for analysis of superoxide dismutase (SOD), malondialdehyde (MDA), tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6), arterial oxygenation pressure (PaO2), oxygenation index (OI) and lung compliance (CL). RESULTS: At the time points of T1, T2 and T3, SOD level was significantly higher and IL-6 level was significantly lower in the DF group than in F group (P < 0.05). The patients in DF group showed significantly higher PaO2, OI and CL index than those in F group at all the 3 time points. CONCLUSIONS: Dexmedetomidine combined with pulmonary protective ventilation strategy can reduce perioperative lung injury in patients undergoing surgery for esophageal cancer with OLV by suppressing inflammation and oxidative stress to improve lung function and reduce adverse effects of the surgery.

Novel, non-nitrocatechol catechol-O-methyltransferase inhibitors modulate dopamine neurotransmission in the frontal cortex and improve cognitive flexibility.

RATIONALE: Cognitive impairment is a primary feature of many neuropsychiatric disorders and there is a need for new therapeutic options. Catechol-O-methyltransferase (COMT) inhibitors modulate cortical dopaminergic function and have been proposed as potential cognitive enhancers. Unfortunately, currently available COMT inhibitors are not good candidates due to either poor blood-brain barrier penetration or severe toxicity. OBJECTIVES: To address the need for safe, brain-penetrant COMT inhibitors, we tested multiple novel compounds in a set of preclinical in vivo efficacy assays in rats to determine their ability to inhibit COMT function and viability as potential clinical candidates. METHODS: We measured the change in concentration of dopamine (DA) metabolites in cerebrospinal fluid (CSF) from the cisterna magna and extracellular fluid (ECF) from the frontal cortex produced by our novel compounds. Additionally, we tested the effects of our brain-penetrant COMT inhibitors in an attentional set-shifting assay (ASST). We benchmarked the performance of the novel COMT inhibitors to the effects produced by the known COMT inhibitor tolcapone. RESULTS: We found that multiple COMT inhibitors, exemplified by LIBD-1 and LIBD-3, significantly modulated dopaminergic function measured as decreases in homovanillic acid (HVA) and increases in 3,4-Dihydroxyphenylacetic acid (DOPAC), two DA metabolites, in CSF and the frontal cortex. Additionally, we found that LIBD-1 significantly improved cognitive flexibility in the ASST, an effect previously reported following tolcapone administration. CONCLUSIONS: These results demonstrate that LIBD-1 is a novel COMT inhibitor with promising in vivo activity and the potential to serve as a new therapy for cognitive impairment.