35 research outputs found
Place preference induced by nucleus accumbens amphetamine is impaired by local blockade of Group II metabotropic glutamate receptors in rats
BACKGROUND: The nucleus accumbens (NAc) plays a critical role in amphetamine-produced conditioned place preference (CPP). In previous studies, NAc basal and amphetamine-produced DA transmission was altered by Group II mGluR agents. We tested whether NAc amphetamine CPP depends on Group II mGluR transmission. RESULTS: NAc injections (0.5 μl/side) of the Group II mGluR antagonist (2 S)- a-ethylglutamic acid (EGLU: 0.01–0.8 μg but not 0.001 μg) impaired CPP. The drug did not block the acute locomotor effect of amphetamine. CONCLUSION: Results suggest that Group II mGluRs may be necessary for the establishment of NAc amphetamine-produced CPP. These receptors may also mediate other forms of reward-related learning dependent on this structure
Valley of death: A proposal to build a “translational bridge” for the next generation
There is a great need for novel drug discovery for major mental illnesses, but multiple levels of challenges exist in both academia and industry, spanning from scientific understanding and institutional infrastructure to business risk and feasibility. The “valley of death,” the large gap between basic scientific research and translation to novel therapeutics, underscores the need to restructure education and academic research to cultivate the fertile interface between academia and industry. In this opinion piece, we propose strategies to educate young trainees in the process of drug discovery and development, and prepare them for careers across this spectrum. In addition, we describe a research framework that considers the disease trajectory and underlying biology of mental disorders, which will help to address the core pathophysiology in novel treatments, and may even allow early detection and intervention. We hope that these changes will increase understanding among academia, industry, and government, which will ultimately improve the diagnosis, prognosis and treatment of mental disorders
PSMA-Targeted PET Radiotracer [18F]DCFPyL as an Imaging Biomarker in Inflammatory Bowel Disease
Mohamed Saleh Ismail,1,* Diane E Peters,2,3,* Steven P Rowe,4,5,* Ali Salavati,6 Sowmya Sharma,1 Robert A Anders,7 Martin Pomper,2,4,5,* Barbara S Slusher,2,3,8,* Florin M Selaru1,5,* 1Division of Gastroenterology, Johns Hopkins Medical Institutions, Baltimore, MD, USA; 2Department of Pharmacology and Molecular Sciences, Johns Hopkins Medical Institutions, Baltimore, MD, USA; 3Johns Hopkins Drug Discovery, Baltimore, MD, USA; 4Russell H. Morgan Department of Radiology and Radiological Science, Johns Hopkins Medical Institutions, Baltimore, MD, USA; 5The Sidney Kimmel Comprehensive Cancer Center, Johns Hopkins Medical Institutions, Baltimore, MD, USA; 6Ahmanson Translational Theranostics Division, Department of Molecular and Medical Pharmacology, University of California Los Angeles (UCLA), Los Angeles, CA, USA; 7The Bloomberg-Kimmel Institute for Cancer Immunotherapy, Johns Hopkins Medical Institutions, Baltimore, MD, USA; 8Department of Neurology, Johns Hopkins Medical Institutions, Baltimore, MD, USA*These authors contributed equally to this workCorrespondence: Florin M Selaru; Barbara S Slusher, Email [email protected]; [email protected]: Prostate-specific membrane antigen (PSMA) is highly and specifically upregulated in active-inflamed mucosa of patients with inflammatory bowel disease (IBD). We hypothesized that this upregulation would be detectable using a PSMA-targeted positron emission tomography/computed tomography (PET/CT) imaging agent, [18F]DCFPyL, enabling non-invasive visualization of inflammation. A noninvasive means of detecting active inflammation would have high clinical value in localization and management of IBD.Study: We performed [18F]DCFPyL imaging in three IBD patients with active disease. Abnormally increased gastrointestinal [18F]DCFPyL uptake was observed in areas with endoscopic, histologic, and immunohistochemical inflammation, demonstrating partial overlap of segments of bowel with abnormal [18F]DCFPyL uptake and active inflammation.Conclusion: This study demonstrates that PSMA-targeted [18F]DCFPyL PET can effectively detect regions of inflamed mucosa in patients with IBD, suggesting its utility as a non-invasive imaging agent to assess location, extent, and disease activity in IBD.Keywords: IBD, disease activity, PSMA, GCPII, [18F]DCFPy
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Neuroprotective effects of a dendrimer-based glutamate carboxypeptidase inhibitor on superoxide dismutase transgenic mice after neonatal hypoxic-ischemic brain injury.
The result of a deprivation of oxygen and glucose to the brain, hypoxic-ischemic encephalopathy (HIE), remains the most common cause of death and disability in human neonates globally and is mediated by glutamate toxicity and inflammation. We have previously shown that the enzyme glutamate carboxypeptidase (GCPII) is overexpressed in activated microglia in the presence of inflammation in fetal/newborn rabbit brain. We assessed the therapeutic utility of a GCPII enzyme inhibitor called 2-(3-Mercaptopropyl) pentanedioic acid (2MPPA) attached to a dendrimer (D-2MPPA), in order to target activated microglia in an experimental neonatal hypoxia-ischemia (HI) model using superoxide dismutase transgenic (SOD) mice that are often more injured after hypoxia-ischemia than wildtype animals. SOD overexpressing and wild type (WT) mice underwent permanent ligation of the left common carotid artery followed by 50 min of asphyxiation (10% O2) to induce HI injury on postnatal day 9 (P9). Cy5-labeled dendrimers were administered to the mice at 6 h, 24 h or 72 h after HI and brains were evaluated by immunofluorescence analysis 24 h after the injection to visualize microglial localization and uptake over time. Expression of GCPII enzyme was analyzed in microglia 24 h after the HI injury. The expression of pro- and anti-inflammatory cytokines were analyzed 24 h and 72 h post-HI. Brain damage was analyzed histologically 7 days post-HI in the three randomly assigned groups: control (C); hypoxic-ischemic (HI); and HI mice who received a single dose of D-2MPPA 6 h post-HI (HI+D-2MPPA). First, we found that GCPII was overexpressed in activated microglia 24 h after HI in the SOD overexpressing mice. Also, there was an increase in microglial activation 24 h after HI in the ipsilateral hippocampus which was most visible in the SOD+HI group. Dendrimers were mostly taken up by microglia by 24 h post-HI; uptake was more prominent in the SOD+HI mice than in the WT+HI. The inflammatory profile showed significant increase in expression of KC/GRO following injury in SOD mice compared to WT at 24 and 72 h. A greater and significant decrease in KC/GRO was seen in the SOD mice following treatment with D-2MPPA. Seven days after HI, D-2MPPA treatment decreased brain injury in the SOD+HI group, but not in WT+HI. This reduced damage was mainly seen in hippocampus and cortex. Our data indicate that the best time point to administer D-2MPPA is 6 h post-HI in order to suppress the expression of GCPII by 24 h after the damage since dendrimer localization in microglia is seen as early as 6 h with the peak of GCPII upregulation in activated microglia seen at 24 h post-HI. Ultimately, treatment with D-2MPPA at 6 h post-HI leads to a decrease in inflammatory profiles by 24 h and reduction in brain injury in the SOD overexpressing mice
Filtered sunlight versus intensive electric powered phototherapy in moderate-to-severe neonatal hyperbilirubinaemia: a randomised controlled non-inferiority trial
Summary: Background: Kernicterus resulting from severe neonatal hyperbilirubinaemia is a leading cause of preventable deaths and disabilities in low-income and middle-income countries, partly because high-quality intensive phototherapy is unavailable. Previously, we showed that filtered-sunlight phototherapy (FSPT) was efficacious and safe for treatment of mild-to-moderate neonatal hyperbilirubinaemia. We aimed to extend these studies to infants with moderate-to-severe hyperbilirubinaemia. Methods: We did a prospective, randomised controlled non-inferiority trial in Ogbomoso, Nigeria—a simulated rural setting. Near-term or term infants aged 14 days or younger who were of 35 weeks or more gestational age and with total serum bilirubin concentrations at or above the recommended age-dependent treatment levels for high-risk neonates were randomly assigned (1:1) to either FSPT or intensive electric phototherapy (IEPT). Randomisation was computer-generated, and neither clinicians nor the parents or guardians of participants were masked to group allocation. FSPT was delivered in a transparent polycarbonate room lined with commercial tinting films that transmitted effective phototherapeutic light, blocked ultraviolet light, and reduced infrared radiation. The primary outcome was efficacy, which was based on assessable treatment days only (ie, those on which at least 4 h of phototherapy was delivered) and defined as a rate of increase in total serum bilirubin concentrations of less than 3·4 μmol/L/h in infants aged 72 h or younger, or a decrease in total serum bilirubin concentrations in those older than 72 h. Safety was defined as no sustained hypothermia, hyperthermia, dehydration, or sunburn and was based on all treatment days. Analysis was by intention to treat with a non-inferiority margin of 10%. Findings: Between July 31, 2015, and April 30, 2017, 174 neonates were enrolled and randomly assigned: 87 to FSPT and 87 to IEPT. Neonates in the FSPT group received 215 days of phototherapy, 82 (38%) of which were not assessable. Neonates in the IEPT group received 219 treatment days of phototherapy, 67 (31%) of which were not assessable. Median irradiance was 37·3 μW/cm2/nm (IQR 21·4–56·4) in the FSPT group and 50·4 μW/cm2/nm (44·5–66·2) in the IEPT group. FSPT was efficacious on 116 (87·2%) of 133 treatment days; IEPT was efficacious on 135 (88·8%) of 152 treatment days (mean difference −1·6%, 95% CI −9·9 to 6·7; p=0·8165). Because the CI did not extend below −10%, we concluded that FSPT was not inferior to IEPT. Treatment was safe for all neonates. Interpretation: FSPT is safe and no less efficacious than IEPT for treatment of moderate-to-severe neonatal hyperbilirubinaemia in near-term and term infants. Funding: Thrasher Research Fund and National Center for Advancing Translational Sciences