1,721,435 research outputs found
Proteomic studies of formalin-fixed paraffin-embedded tissues
No full textFormalin-fixed paraffin-embedded (FFPE) tissue specimens represent a valuable informational resource of histologically characterized specimens for proteomic studies. In this article, the authors review the advancement performed in the field of FFPE proteomics focusing on formaldehyde treatment and on strategies addressed to obtain the best recovery in the protein/peptide extraction. A variety of approaches have been used to characterize protein tissue extracts, and many efforts have been performed demonstrating the comparability between fresh/frozen and FFPE proteomes. Finally, the authors report and discuss the large numbers of works aimed at developing new strategies and sophisticated platforms in the analysis of FFPE samples to validate known potential biomarkers and to discover new ones
Update on proteomic studies of formalin-fixed paraffin-embedded tissues
No full textIntroduction: This review is an update on recent progress in proteomic studies of formalin-fixed paraffin-embedded (FFPE) tissues, which open the opportunity to investigate diseases and research potential biomarkers, particularly when availability of fresh/frozen tissues is low. Areas covered: We described improvement of existing protocols or the new ones regarding deparaffinization and protein extraction of FFPE samples published from 2014 to today. Moreover, the growing interest to use FFPE tissues for mass spectrometry imaging approach is presented together with the search of post-translational modifications. Expert opinion: In the last few years, the number of papers using FFPE tissues in proteomic analysis is growing. The interest to apply proteomic analysis to FFPE tissues lies in the easy accessibility of a great number of samples from archives. Nevertheless, standardization in the approach among the different researchers is not achieved, making essentially incomparable the results obtained. This limit should be overcome
Characterization of a low affinity-binding site for N-6-substituted adenosine derivatives in rat testis membranes
No full textThe binding characteristics of radiolabeled N-6-(cyclohexyl)adenosine ([H-3]CHA), N-6-(R-phenylisopropyl)adenosine ([H-3]R-PIA), 5'-N-ethyl-carboxamidoadenosine ([H-3]NECA), and 2-[4-(2-carboxyethyl)phenyl]ethyl-amino-5'-N-ethylcarboxamidoadenosine ([H-3]CGS 21680), to rat testis membranes were investigated. Specific binding of [H-3]CGS 21680, a selective agonist for the A(2a) adenosine receptor, was very modest whilst the nonselective agonist [H-3]NECA bound to rat testis membranes showing high binding capacity. At least two types of binding sites for [H-3]NECA could be identified in rat testis membranes: high affinity sites and high capacity sites. Selective agonists for the A(1) adenosine receptor, [H-3]CHA and [H-3]R-PIA bound with high affinity to a single class of binding sites. This high affinity binding site showed the typical pharmacological specificity of the A(1) adenosine receptor with a potency order fur agonists of CHA greater than or equal to R-PIA greater than or equal to NECA greater than or equal to N-6-(S-phenylisopropyl)adenosine (S-PIA). In order to detect the presence of the A(3) adenosine receptor in these membranes we selectively blocked the A(1) receptor with a large molar excess of a xanthine antagonist, either 1,3-dipropyl-8-cyclopentylxanthine (DPCPX) or xanthine amine congener (XAC). In the presence of an antagonist a low affinity binding site for [H-3]CHA and [H-3]R-PIA was detected. This low affinity binding site showed a different pharmacological specificity than the high affinity binding site. In fact the potency order for agonists was CHA greater than or equal to NECA = R-PIA > S-PIA. This finding suggests that the low affinity binding site represents the A(3) adenosine receptor
Two dimensional maps of human lymphocytes: identification of tubby protein in normal and obese subjects.
No full textProteomics insight into psychiatric disorders: an update on biological fluid biomarkers
No full textIntroduction: Psychiatric disorders are severe, debilitating and heterogeneous diseases with a high impact on public health. In this review we address state of the art clinical approaches to diagnose psychiatric disorders and underline the necessity to found new tools to help clinicians. Areas covered: We provide an update on proteomic studies and suggest potential biomarkers focusing on schizophrenia (SCZ), bipolar disorder (BD), and major depression (MD). In particular, we direct our attention to proteomic results obtained from studies on biological fluids. We also show an interaction analysis of differentially expressed proteins found in SCZ, BD and MD. Expert commentary: To date, there is a need to find molecular biomarkers for psychiatric disorders. The use of a proteomic approach allows protein fingerprints to be defined in normal and pathological states. We believe that saliva is an intriguing biological fluid, whose proteomic study in psychiatric disorders is still in its early stages
Characterization of peripheral-type benzodiazepine binding sites from rat and pig pancreas.
No full textThe binding of [H-3]1-(2-chlorophenyl-N-methyl-1-methyl-propyl)-3-isoquinolinecarb oxamide ([H-3]PK-11195) and [H-3]7-chloro-1,3-dihydro-1-methyl-5-(p-chlorophenyl)-2H-1,4-benzodiazep in-2-on ([H-3]Ro5-4864) to membrane preparations of pancreas was studied in the rat and pig. [H-3]PK-11195 bound with high affinity to rat and pig membrane preparations yielding maximal numbers of binding sites (B-max) of 2393 +/- 160 and 777 a 65 fmol/mg of protein, respectively, and equilibrium dissociation constant (K-d) values of 3.01 c 0.25 and 3.9 +/- 0.23 nM, respectively. [H-3]Ro5-4864 successfully labelled rat but not pig pancreatic membranes, yielding a Kd value of 6.45 +/- 0.5 nM and a B-max value of 551 +/- 43 fmol/mg of protein. Displacement studies showed a similar rank order of potency of various unlabelled ligands against both [H-3]Ro5-4864 and [H-3]PK-11195 binding to rat and pig membrane preparations (PK-11195 greater than or equal to Ro5-4864 > diazepam > flunitrazepam much greater than flumazenil). These results suggest that [H-3]PK-11195 binds with high affinity and specificity to rat and pig pancreas and [H-3]Ro5-4864 binds with high affinity and specificity to rat but not pig pancreas
Modulation of A(1) adenosine receptor signaling by peroxynitrite
No full textNitric oxide (NO) is a gaseous free radical involved in many pathophysiological processes. During oxidative stress, NO, its derivatives and adenosine are released. Considering adenosine neuroprotective role in the central nervous system (CNS) and toxicity of NO, we investigated the effect of a NO/peroxynitrite (ONOO-) donor, 3-morpholinosydnonimine (SIN-1), on A(1) adenosine receptor (A(1)AR) signaling pathway in rat cortical membranes. Membrane treatment with 0.5 mM SIN-1 for various periods of time (0-240 min) decreased specific binding of the radiolabeled A(1)AR agonist, [H-3]N-6-cyclohexyladenosine ([H-3]CHA), in a time-dependent manner, reaching the steady state after 120 min. The inhibitory effect of SIN-1 was concentration-dependent, with an EC50 value of 0.60 +/- 0.30 mM (N = 3). Membrane pre-incubation with the superoxide anion (O-2(.-)) scavenger superoxide dismutase (SOD) followed by SIN-1 addition, abolished SIN-1 inhibition of [H-3]CHA binding. Membrane treatment with 0.5 mM SIN-1 for 120 min caused a significant 2-fold increase of the K-D value for [H-3]CHA without changing the B-max value. Moreover, pre-incubation of membranes with A(1)AR agonists, CHA or N-6-(2-phenylisopropyl)-adenosine (R-PIA) before SIN-1 addition increased the inhibitory effect while the selective A(1)AR antagonist, 8-cyclopentyl-1,3-dipropylxanthine (DPCPX) had no activity. Membrane treatment with SIN-1 decreased receptor-stimulated guanosine 5'-O-(gamma[S-35]thio)triphosphate ([S-35]GTPgammaS) binding in a concentration-dependent manner. This treatment influenced [S-35]GTPgammaS binding affinity for A(1)AR activated G(i) proteins in cortical membranes. These findings suggest that ONOO- modulates A(1)AR signaling pathways by affecting receptor G(i) protein coupling. (C) 2003 Elsevier Inc. All rights reserved
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