scholarly journals Simultaneous measurement and quantitation of 4-hydroxyphenylacetic acid and dopamine with fast-scan cyclic voltammetry

The Analyst ◽  
2015 ◽  
Vol 140 (9) ◽  
pp. 3039-3047 ◽  
Author(s):  
Mimi Shin ◽  
Sam V. Kaplan ◽  
Kayla D. Raider ◽  
Michael A. Johnson
Keyword(s):  
Cell Culture ◽  
Cyclic Voltammetry ◽  
Simultaneous Measurement ◽  
Ex Vivo ◽  
Neuronal Function ◽  
Fast Scan Cyclic Voltammetry ◽  
Tissue Samples ◽  
Caged Compounds ◽  
Hydroxyphenylacetic Acid

Caged compounds have been used extensively to investigate neuronal function in a variety of preparations, including cell culture,ex vivotissue samples, andin vivo.

scholarly journals Corrigendum: In vivo Hippocampal Serotonin Dynamics in Male and Female Mice: Determining Effects of Acute Escitalopram Using Fast Scan Cyclic Voltammetry

2019 ◽  
Vol 13 ◽  
Author(s):  
Rachel A. Saylor ◽  
Melinda Hersey ◽  
Alyssa West ◽  
Anna Marie Buchanan ◽  
Shane N. Berger ◽  
...  
Keyword(s):  
Cyclic Voltammetry ◽  
Fast Scan Cyclic Voltammetry ◽  
Male And Female ◽  
Female Mice

Striatal low-threshold spiking interneurons locally gate dopamine during learning

2020 ◽  
Author(s):  
Elizabeth N. Holly ◽  
M. Felicia Davatolhagh ◽  
Rodrigo A. España ◽  
Marc V. Fuccillo
Keyword(s):  
Cyclic Voltammetry ◽  
Dopamine Release ◽  
Striatal Dopamine ◽  
Operant Learning ◽  
Fast Scan Cyclic Voltammetry ◽  
Directed Learning ◽  
Low Threshold ◽  
Dorsomedial Striatum

Low-threshold spiking interneurons (LTSIs) in the dorsomedial striatum are potent modulators of goal-directed learning. Here, we uncover a novel function for LTSIs in locally and directly gating striatal dopamine, using in vitro fast scan cyclic voltammetry as well as in vivo GRAB-DA sensor imaging and pharmacology during operant learning. We demonstrate that LTSIs, acting via GABAB signaling, attenuate dopamine release, thereby serving as local coordinators of striatal plasticity.

Tissue Models of Peritoneal Fibrosis

2005 ◽  
Vol 28 (2) ◽  
pp. 105-111 ◽  
Author(s):  
J.A. Jiménez-Heffernan ◽  
A. Cirugeda ◽  
M.A. Bajo ◽  
G. Del Peso ◽  
M.L. Pérez-Lozano ◽  
...  
Keyword(s):  
Acute Inflammation ◽  
Epithelial To Mesenchymal Transition ◽  
Ex Vivo ◽  
Peritoneal Fibrosis ◽  
Tissue Samples ◽  
Mesenchymal Transition ◽  
Cellular Markers ◽  
Tissue Models ◽  
Myofibroblastic Differentiation

Objective To evaluate the utility of peritoneal pathologic samples, unrelated to peritoneal dialysis (PD) treatment, for the study of peritoneal fibrosis and inflammation. Methods Comparative morphologic and immunohistochemical study of peritoneal pathologic samples unrelated to PD with peritoneal biopsies from PD patients with special emphasis on the expression of myofibroblastic and epithelial-to-mesenchymal transition markers. Results Regarding morphology, PD-related simple fibrosis was less cellular, with greater stromal hyalinization, determining a homogeneous, hypocellular aspect of the submesothelium. In contrast, non-PD fibrosis was more cellular with an extracellular matrix showing a dense and fibrillar quality with wide bundles of collagen. Hylinazing vasculopathy was only present in PD samples. Myofibroblastic differentiation and epithelial-to-mesenchymal transition were common findings in all situations of peritoneal fibrosis. Calponin and calretinin are useful cellular markers to study such fibrogenic mechanisms and correlate with other well-known markers such as α-SMA and cytokeratins. Their expression was much more intense in those samples showing acute inflammation (peritonitis). Conclusions Non-PD models of peritoneal fibrosis seem very useful to evaluate important features of human peritoneal pathology such us fibrogenesis, and inflammation. Fibrogenic events such as myofibroblastic differentiation and epithelial-to-mesenchymal transition are evident in these tissue samples allowing us to use them as an accessible source for in vivo and ex vivo studies. Both events show their maximal expression in situations of acute inflammation supporting the important role that peritonitis episodes play in the progression of fibrosis.

Leveraging RB status to define therapy for castrate-resistant prostate cancer.

2014 ◽  
Vol 32 (4_suppl) ◽  
pp. 96-96
Author(s):  
Renee de Leeuw ◽  
Clay de Comstock ◽  
Daniela de Pollutri ◽  
Matthew Joseph Schiewer ◽  
Stephen J Ciment ◽  
...  
Keyword(s):  
Prostate Cancer ◽  
Kinase Inhibitors ◽  
Ex Vivo ◽  
Tissue Samples ◽  
Ki67 Staining ◽  
Cell Architecture ◽  
Castrate Resistant Prostate Cancer ◽  
Castrate Resistant

96 Background: Loss of retinoblastoma (RB) tumor suppressor is overrepresented in castrate-resistant prostate cancer (CRPC) compared to primary PCa. We previously showed using analyses of human tissue and in vitro and in vivo modeling that RB constrains androgen receptor (AR) function, and that loss of RB is sufficient promote resistance to castration and AR antagonists. Thus, novel strategies are needed to treat RB-deficient tumor. By contrast, in tumors retaining RB, suppressing enhancing RB activity would be of therapeutic advantage, and may be accomplished through next-generation Cdk4/6 inhibitors. Methods: Stable isogenic pairs of prostate cancer cell lines either retaining RB or RB depleted (by shRNA) were assessed in vitro and in xenografts for response to Cdk4/6 kinase inhibitors or the cabazitaxel. In addition, using an ex vivo explant assay, fresh tumor tissue samples from radical prostatectomy were exposed to the Cdk4/6 inhibitor or cabazitaxel for up to 7 days, and evaluated by IHC for Ki67, Caspase-3, and AR. Results: Cdk4/6 inhibition blocks tumor cell proliferation dependent on RB status. This was further confirmed ex vivo, as evidenced by a marked reduction in Ki67 staining in Cdk4/6 inhibitor treated explant tissue from two prostate cancer patients. Conversely, in vitro studies revealed a modest sensitization of RB-depleted tumors to cabazitaxel that was dramatically enhanced in vivo and after castration. Cabazitaxel, like docetaxel, targets the cell architecture and induces cell death, but also induces a distinct gene expression profile that may partially explain efficacy in docetaxel-resistant tumors. Neither taxane showed affects on AR nuclear localization using in vivoor explant studies. Conclusions: These results strongly support our hypothesis that RB status can be used as a metric to define therapeutic response to cabazitaxel, as such that loss of RB function induces sensitization taxanes, whereas RB proficient tumors give an enhanced response to Cdk4/6 kinase inhibitors.

scholarly journals Recent Advances in the Detection of Neurotransmitters

Chemosensors ◽  
2018 ◽  
Vol 6 (1) ◽  
pp. 1 ◽  
Author(s):  
Bo Si ◽  
Edward Song
Keyword(s):  
Ex Vivo ◽  
Simultaneous Detection ◽  
High Sensitivity ◽  
Mental Illnesses ◽  
Electrochemical Sensing ◽  
Fast Scan Cyclic Voltammetry ◽  
In Vivo Detection ◽  
Recent Developments ◽  
Materials Used

Neurotransmitters are chemicals that act as messengers in the synaptic transmission process. They are essential for human health and any imbalance in their activities can cause serious mental disorders such as Parkinson’s disease, schizophrenia, and Alzheimer’s disease. Hence, monitoring the concentrations of various neurotransmitters is of great importance in studying and diagnosing such mental illnesses. Recently, many researchers have explored the use of unique materials for developing biosensors for both in vivo and ex vivo neurotransmitter detection. A combination of nanomaterials, polymers, and biomolecules were incorporated to implement such sensor devices. For in vivo detection, electrochemical sensing has been commonly applied, with fast-scan cyclic voltammetry being the most promising technique to date, due to the advantages such as easy miniaturization, simple device architecture, and high sensitivity. However, the main challenges for in vivo electrochemical neurotransmitter sensors are limited target selectivity, large background signal and noise, and device fouling and degradation over time. Therefore, achieving simultaneous detection of multiple neurotransmitters in real time with long-term stability remains the focus of research. The purpose of this review paper is to summarize the recently developed sensing techniques with the focus on neurotransmitters as the target analyte, and to discuss the outlook of simultaneous detection of multiple neurotransmitter species. This paper is organized as follows: firstly, the common materials used for developing neurotransmitter sensors are discussed. Secondly, several sensor surface modification approaches to enhance sensing performance are reviewed. Finally, we discuss recent developments in the simultaneous detection capability of multiple neurotransmitters.

scholarly journals Prospective evaluation of the utility of intraoperative confocal laser endomicroscopy in patients with brain neoplasms using fluorescein sodium: experience with 74 cases

2016 ◽  
Vol 40 (3) ◽  
pp. E11 ◽  
Author(s):  
Nikolay L. Martirosyan ◽  
Jennifer M. Eschbacher ◽  
M. Yashar S. Kalani ◽  
Jay D. Turner ◽  
Evgenii Belykh ◽  
...  
Keyword(s):  
Brain Tumors ◽  
Ex Vivo ◽  
Confocal Laser Endomicroscopy ◽  
Confocal Laser ◽  
Fluorescein Sodium ◽  
Frozen Sections ◽  
Diagnostic Image ◽  
Tissue Samples ◽  
Specificity And Sensitivity

OBJECTIVE This study evaluated the utility, specificity, and sensitivity of intraoperative confocal laser endomicroscopy (CLE) to provide diagnostic information during resection of human brain tumors. METHODS CLE imaging was used in the resection of intracranial neoplasms in 74 consecutive patients (31 male; mean age 47.5 years; sequential 10-month study period). Intraoperative in vivo and ex vivo CLE was performed after intravenous injection of fluorescein sodium (FNa). Tissue samples from CLE imaging–matched areas were acquired for comparison with routine histological analysis (frozen and permanent sections). CLE images were classified as diagnostic or nondiagnostic. The specificities and sensitivities of CLE and frozen sections for gliomas and meningiomas were calculated using permanent histological sections as the standard. RESULTS CLE images were obtained for each patient. The mean duration of intraoperative CLE system use was 15.7 minutes (range 3–73 minutes). A total of 20,734 CLE images were correlated with 267 biopsy specimens (mean number of images/biopsy location, in vivo 84, ex vivo 70). CLE images were diagnostic for 45.98% in vivo and 52.97% ex vivo specimens. After initiation of CLE, an average of 14 in vivo images and 7 ex vivo images were acquired before identification of a first diagnostic image. CLE specificity and sensitivity were, respectively, 94% and 91% for gliomas and 93% and 97% for meningiomas. CONCLUSIONS CLE with FNa provided intraoperative histological information during brain tumor removal. Specificities and sensitivities of CLE for gliomas and meningiomas were comparable to those for frozen sections. These data suggest that CLE could allow the interactive identification of tumor areas, substantially improving intraoperative decisions during the resection of brain tumors.

scholarly journals 3-Hydroxyphenylacetic Acid: A Blood Pressure-Reducing Flavonoid Metabolite

Nutrients ◽  
2022 ◽  
Vol 14 (2) ◽  
pp. 328
Author(s):  
Patrícia Dias ◽  
Jana Pourová ◽  
Marie Vopršalová ◽  
Iveta Nejmanová ◽  
Přemysl Mladěnka
Keyword(s):  
Nitric Oxide ◽  
Blood Pressure ◽  
Ex Vivo ◽  
Laboratory Animals ◽  
Spontaneously Hypertensive ◽  
Porcine Coronary Artery ◽  
Arterial Blood ◽  
Hydroxyphenylacetic Acid ◽  
Dose Dependent Decrease

Regular intake of polyphenol-rich food has been associated with a wide variety of beneficial health effects, including the prevention of cardiovascular diseases. However, the parent flavonoids have mostly low bioavailability and, hence, their metabolites have been hypothesized to be bioactive. One of these metabolites, 3-hydroxyphenylacetic acid (3-HPAA), formed by the gut microbiota, was previously reported to exert vasorelaxant effects ex vivo. The aim of this study was to shed more light on this effect in vivo, and to elucidate the mechanism of action. 3-HPAA gave rise to a dose-dependent decrease in arterial blood pressure when administered i.v. both as a bolus and infusion to spontaneously hypertensive rats. In contrast, no significant changes in heart rate were observed. In ex vivo experiments, where porcine hearts from a slaughterhouse were used to decrease the need for laboratory animals, 3-HPAA relaxed precontracted porcine coronary artery segments via a mechanism partially dependent on endothelium integrity. This relaxation was significantly impaired after endothelial nitric oxide synthase inhibition. In contrast, the blockade of SKCa or IKCa channels, or muscarinic receptors, did not affect 3-HPAA relaxation. Similarly, no effects of 3-HPAA on cyclooxygenase nor L-type calcium channels were observed. Thus, 3-HPAA decreases blood pressure in vivo via vessel relaxation, and this mechanism might be based on the release of nitric oxide by the endothelial layer.

scholarly journals In Vivo and Ex Vivo Evaluation of 1,3-Thiazolidine-2,4-Dione Derivatives as Euglycemic Agents

PPAR Research ◽  
2021 ◽  
Vol 2021 ◽  
pp. 1-11
Author(s):  
Diana Alemán-González-Duhart ◽  
Samuel Álvarez-Almazán ◽  
Miguel Valdes ◽  
Feliciano Tamay-Cach ◽  
Jessica Elena Mendieta-Wejebe
Keyword(s):  
Antioxidant Activity ◽  
Ex Vivo ◽  
Peroxisome Proliferator ◽  
Oral Toxicity ◽  
Peroxisome Proliferator Activated Receptor ◽  
Tissue Samples ◽  
Design Synthesis ◽  
Antioxidant Agents ◽  
Male Wistar Rats

Thiazolidinediones (TZDs), used to treat type 2 diabetes mellitus, act as full agonists of the peroxisome proliferator-activated receptor gamma. Unfortunately, they produce adverse effects, including weight gain, hepatic toxicity, and heart failure. Our group previously reported the design, synthesis, in silico evaluation, and acute oral toxicity test of two TZD derivatives, compounds 40 (C40) and 81 (C81), characterized as category 5 and 4, respectively, under the Globally Harmonized System. The aim of this study was to determine whether C40, C81, and a new compound, C4, act as euglycemic and antioxidant agents in male Wistar rats with streptozotocin-induced diabetes. The animals were randomly divided into six groups ( n = 7 ): the control, those with diabetes and untreated, and those with diabetes and treated with pioglitazone, C40, C81, or C4 (daily for 21 days). At the end of the experiment, tissue samples were collected to quantify the level of glucose, insulin, triglycerides, total cholesterol, and liver enzymes, as well as enzymatic and nonenzymatic antioxidant activity. C4, without a hypoglycemic effect, displayed the best antioxidant activity. Whereas C81 could only attenuate the elevated level of blood glucose, C40 generated euglycemia by the end of the treatment. All compounds produced a significant decrease in triglycerides.

scholarly journals In vivo Hippocampal Serotonin Dynamics in Male and Female Mice: Determining Effects of Acute Escitalopram Using Fast Scan Cyclic Voltammetry

2019 ◽  
Vol 13 ◽  
Author(s):  
Rachel A. Saylor ◽  
Melinda Hersey ◽  
Alyssa West ◽  
Anna Marie Buchanan ◽  
Shane N. Berger ◽  
...  
Keyword(s):  
Cyclic Voltammetry ◽  
Fast Scan Cyclic Voltammetry ◽  
Male And Female ◽  
Female Mice
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