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Neuroprotective potential of Cordia dichotoma in Parkinson's syndrome induced by haloperidol: An animal study. Saudi Pharm J 2023; 31:101791. [PMID: 37771955 PMCID: PMC10523271 DOI: 10.1016/j.jsps.2023.101791] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2023] [Accepted: 09/12/2023] [Indexed: 09/30/2023] Open
Abstract
Background Parkinson's disease (PD) is one of the major neurodegenerative disorders and the prevalence is expected to increase during the next couple of decades. There is a need for safe and effective therapeutic regimen that can effectively manage this neurotoxicity. The leaves and several other parts of Cordia dichotoma are known to possess number of medicinal properties. The purpose of this study was to examine the neuroprotective role of Cordia dichotoma in an experimental model of haloperidol-induced P.D. Materials and methods Five groups of rats were randomly assigned into different groups. Intraperitoneal haloperidol 1 mg/kg was given to the inducer group and 0.5% CMC to the normal control. The reference standard was syndopa 10 mg/kg, p.o., and the test group animals received C. dichotoma's ethanolic extract at 200 and 400 mg/kg orally for one week. Rats exposed to haloperidol were assessed for behavioral, neurochemical, and histopathological parameters. Results C. dichotoma leaves extract dose-dependently increased behavioral activity and muscle coordination. The extract at 400 mg/kg was found to increase significantly (P < 0.001) the central square activity in open-field test, compared to haloperidol treated rats. In stepping test, both tested doses of C. dichotoma (200 mg and 400 mg/kg) were found to significantly (P < 0.001) reduce akinesia, besides these doses also decreased the catatonic responses induced by haloperidol. Further, the extraction treatment (200 mg and 400 mg/kg) significantly (P < 0.001) decreased malonaldehyde and increased antioxidant enzymes like catalase compared to the control group. Histopathological changes in the test group showed a significant reduction in haloperidol damage to normal morphology in cortical, hippocampus, substantia nigra, and pyramidal. Conclusion The observations of the study suggest that Cordia dichotoma attenuated the haloperidol-induced neurological changes, indicating that the plant might benefit in the treatment of Parkinson's disease. The activity of Cordia dichotoma could be linked to its antioxidant property. Since, the drug is traditionally used in different parts of world; it could be a promising agent if more research establishes its safety and efficacy in other experimental models of Parkinson's Disease.
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Nephroprotective potential of Polyalthia longifolia roots against vancomycin-induced renal toxicity in experimental animals. Front Pharmacol 2023; 14:1107435. [PMID: 36755952 PMCID: PMC9900101 DOI: 10.3389/fphar.2023.1107435] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2022] [Accepted: 01/09/2023] [Indexed: 01/24/2023] Open
Abstract
This study was done to investigate the possible nephroprotective effect of an ethanolic root extract of Polyalthia Longifolia (PL) on vancomycin-induced nephrotoxicity using curative and protective models. Vancomycin (150 mg/kg, intravenous) was given to healthy Wistar albino rats in the curative model before the start of treatment, whereas the protective group received vancomycin at the conclusion of the 10-day treatment procedure. Animals were divided into six groups for both models; group I served as the normal control, while groups II, III, IV, V, and VI were kept as toxic control, standard (selenium, 6 mg/kg), LDPL (low dose of PL 200 mg/kg), HDPL (high dose of PL 400 mg/kg), and HDPL + selenium (interactive) groups, respectively. Renal biomarkers [(uric acid, creatinine, blood urea nitrogen (BUN), serum proteins], and blood electrolyte levels were measured for all tested groups. When compared to the vancomycin group, the HDPL significantly (p < 0.01) showed greater effectiveness in lowering the BUN, potassium, and calcium levels. Additionally, in the curative model, there was a significant (p < 0.05) decrease in the blood levels of uric acid, creatinine, BUN, potassium, and calcium in the animals who received the combination of selenium and HDPL. Both LDPL and HDPL did not provide any distinguishable effect in the protective model, but groups that received HDPL with selenium did provide detectable protection by significantly lowering their levels of uric acid, BUN, serum potassium, and total serum protein in comparison to the vancomycin control group. These findings indicate that, whether administered before or after renal damage is induced, the Polyalthia longifolia root extract provided only modest protection to nephrons, which require selenium support to prevent vancomycin-induced kidney damage.
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COMPARATIVE ANALYSIS OF TRADITIONAL CLASSIFICATION AND DEEP LEARNING IN LUNG CANCER PREDICTION. BIOMEDICAL ENGINEERING: APPLICATIONS, BASIS AND COMMUNICATIONS 2022. [DOI: 10.4015/s101623722250048x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
The cancer is an intimidating illness. Extra care is necessary while making a diagnosis. To aid the identification process, medical imaging plays a crucial role by producing images of the internal organs of the body for better diagnosis of cancer. Medical images are typically utilized by radiologists, engineers, and clinicians to spot the inner constitution of either individual patients or group of individuals. Most doctors prefer computed tomography (CT) images for initial screening of cancer — mainly lung cancer. To achieve deeper understanding and categorization of lung cancer, diverse machine learning techniques are employed in image classification. Many research works have been done on the classification of CT images with different algorithms, but they failed to reach 100% accuracy. By applying methods like Support Vector Machine, deep learning system like artificial neural network (ANN) and proposed convolution neural network (CNN), a computerized system can be built for truthful classification. The models are built as a classification system that can identify the nodule, if present in the lungs, as benign, malignant or normal or as benign or normal. Lung cancer datasets at Iraq National Center aimed at Cancer Diseases (IQ-OTHNCCD) and Iran Hospital-based CT images are used in this research. SVM, ANN, and proposed CNN classification techniques are applied to the datasets considered. This research work, proposes a model for classification of CT images with very promising accuracy on the datasets considered.
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Anti-dengue Potential of Mangiferin: Intricate Network of Dengue to Human Genes. REVISTA BRASILEIRA DE FARMACOGNOSIA 2022; 32:410-420. [PMID: 35572718 PMCID: PMC9078210 DOI: 10.1007/s43450-022-00258-6] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/28/2021] [Accepted: 04/14/2022] [Indexed: 11/21/2022]
Abstract
Dengue fever has become one of the deadliest infectious diseases and requires the development of effective antiviral therapies. It is caused by members of the Flaviviridae family, which also cause various infections in humans, including dengue fever, tick-borne encephalitis, West Nile fever, and yellow fever. In addition, since 2019, dengue-endemic regions have been grappling with the public health and socio-economic impact of the ongoing coronavirus disease 19. Co-infections of coronavirus and dengue fever cause serious health complications for people who also have difficulty managing them. To identify the potentials of mangiferin, a molecular docking with various dengue virus proteins was performed. In addition, to understand the gene interactions between human and dengue genes, Cytoscape was used in this research. The Kyoto Encyclopedia of Genes and Genomes software was used to find the paths of Flaviviridae. The Kyoto Encyclopedia of Genes and Genomes and the Reactome Pathway Library were used to understand the biochemical processes involved. The present results show that mangiferin shows efficient docking scores and that it has good binding affinities with all docked proteins. The exact biological functions of type I interferon, such as interferon-α and interferon-β, were also shown in detail through the enrichment analysis of the signaling pathway. According to the docking results, it was concluded that mangiferin could be an effective drug against the complications of dengue virus 1, dengue virus 3, and non-structural protein 5. In addition, computational biological studies lead to the discovery of a new antiviral bioactive molecule and also to a deeper understanding of viral replication in the human body. Ultimately, the current research will be an important resource for those looking to use mangiferin as an anti-dengue drug.
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Anti-viral effectuality of plant polyphenols against mutated dengue protein NS2B47-NS3: A computational exploration. GENE REPORTS 2022. [DOI: 10.1016/j.genrep.2022.101546] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
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Out of Site, Out of Mind- A Rare Case of Adrenal Histoplasmosis from a Non Endemic Area. J Clin Diagn Res 2022. [DOI: 10.7860/jcdr/2022/56585.16832] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
There has been a rising trend in the number of histoplasmosis cases reported in the recent years. However, in southern India, the number of cases is relatively less. This report is about a 46-year-old Indian male from Tamil Nadu who presented with decreased appetite, vomiting, and giddiness. In view of persistent hyponatremia and hypotension, a work-up for adrenal insufficiency was done, and serum cortisol was found to be low. Contrast Enhanced Computed Tomography (CECT) showed bilateral adrenal enlargement with peripheral rim enhancement and hypodense areas within. There was a diagnostic dilemma between tubercular and fungal aetiology. Fine Needle Aspiration Cytology (FNAC) of the adrenal gland showed features suggestive of histoplasmosis. The patient was treated with itraconazole along with steroid replacement therapy, leading to marked improvement in his overall condition. In immunocompetent individuals, disseminated histoplasmosis with adrenal gland involvement is a rare occurrence. As an unusual presentation of histoplasmosis, this case adds to the body of literature available from Tamil Nadu, which is a non endemic region for histoplasmosis, with only 15 cases being reported as of 2018.
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Cotton Dust Induced Pneumonia in Geriatric Patients in Kongu Nadu Region: A Case History. J Young Pharm 2019. [DOI: 10.5530/jyp.2019.11.63] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
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Synthesis, Characterization, and Antimicrobial Activity of a Series of 2-(5-Phenyl-1,3,4-oxadiazol-2-yl)-N-[(1-aryl-1H-1,2,3-triazol-4-yl)methyl]anilines Using Click Chemistry. RUSS J GEN CHEM+ 2018. [DOI: 10.1134/s1070363218070228] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
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Exchanged folded crossed cube: A new interconnection network for parallel computation. INFORM PROCESS LETT 2018. [DOI: 10.1016/j.ipl.2018.04.017] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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Quantum mechanical study and spectroscopic (FT-IR, FT-Raman, (13)C, (1)H) study, first order hyperpolarizability, NBO analysis, HOMO and LUMO analysis of 2-acetoxybenzoic acid by density functional methods. SPECTROCHIMICA ACTA. PART A, MOLECULAR AND BIOMOLECULAR SPECTROSCOPY 2015; 136 Pt C:1260-1268. [PMID: 25456668 DOI: 10.1016/j.saa.2014.10.012] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/30/2014] [Revised: 07/18/2014] [Accepted: 10/08/2014] [Indexed: 06/04/2023]
Abstract
In this work, colorless crystals of 2-acetoxybenzoic acid were grown by slow evaporation method and the FT-IR and FT-Raman spectra of the sample were recorded in the region 4000-500cm(-1) and 4000-100cm(-1) respectively. Molecular structure is optimized with the help of density functional theory method (B3LYP) with 6-31+G(d,p), 6-311++G(d,p) basis sets. Stability of the molecule arising from hyperconjugation and charge delocalization is confirmed by the natural bond orbital analysis (NBO). The results show that electron density (ED) in the σ(∗) antibonding orbitals and E(2) energies confirms the occurrence of intramolecular charge transfer (ICT) within the molecule. The assignments of the vibrational spectra have been carried out with the help of normal coordinate analysis following the scaled quantum mechanical force field (SQMFF) methodology. The results of the calculations were applied to simulated spectra of the title compound, which show excellent agreement with observed spectra. The (1)H and (13)C nuclear magnetic resonance (NMR) chemical shifts of the molecule were calculated by GIAO method. Mulliken population analysis on atomic charges is also calculated. The calculated HOMO and LUMO energy gap shows that charge transfer occurs within the molecule.
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Troxerutin suppresses lipid abnormalities in the heart of high-fat–high-fructose diet-fed mice. Mol Cell Biochem 2013; 387:123-34. [DOI: 10.1007/s11010-013-1877-2] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2013] [Accepted: 10/18/2013] [Indexed: 12/28/2022]
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A novel trifunctional organocatalyst for the asymmetric aldol reaction: a facile enantioselective synthesis of β-hydroxyketones. ACTA ACUST UNITED AC 2011. [DOI: 10.1016/j.tetasy.2011.05.001] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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13
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The forearm tourniquet Bier block. Logic and authority versus science and experience. Minerva Anestesiol 2010; 76:91-92. [PMID: 20150848] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
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Composition and larvicidal activity of leaves and stem essential oils of Chloroxylon swietenia DC against Aedes aegypti and Anopheles stephensi. BIORESOURCE TECHNOLOGY 2006; 97:2481-4. [PMID: 16815011 DOI: 10.1016/j.biortech.2005.10.003] [Citation(s) in RCA: 53] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/27/2005] [Revised: 09/30/2005] [Accepted: 10/03/2005] [Indexed: 05/10/2023]
Abstract
The laboratory bioassay of the essential oil and the isolated compounds from Chloroxylon swietenia against Aedes aegypti and Anopheles stephensi was carried out to evaluate the larvicidal activity. LC50 value estimated for A. aegypti and An. stephensi were 16.5 and 14.9 microg/ml and 20.2 and 19 microg/ml for leaf and stem oils, respectively. The three sesquiterpenes pregeijerene, geijerene and germacrene D were isolated and their Larvicidal activity was evaluated. Pregeijerene and geijerene were observed for the first time in the volatile constituents of C. swietenia, however, leaves contained higher amount of geijerene compared to stems.
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Identification and evaluation of LPS antigen for serodiagnosis of uveitis associated with leptospirosis. J Med Microbiol 2003; 52:667-673. [PMID: 12867560 DOI: 10.1099/jmm.0.05120-0] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Leptospirosis is a widespread zoonotic disease that affects all mammals in different parts of the world. Though there are many commercial kits available for the diagnosis of systemic leptospirosis, the nature of the antigen has not been described. Therefore, identification of a specific antigen is important. Since ocular involvement in leptospirosis has been reported, there is a need to identify and characterize the leptospiral antigen for diagnosis of uveitis associated with past leptospiral infection (leptospiral uveitis) and for confirming the clinical diagnosis. Seven-day-old culture of Leptospira biflexa serovar Patoc was used for preparing the antigen. The present study included serum samples from 81 patients with clinical criteria for leptospiral uveitis, 15 cataract controls and 15 non-leptospiral uveitis controls. Serum samples were assayed by ELISA using our antigenic preparation and by a microscopic agglutination test (MAT) using 19 serovars. The antigen prepared had 280 micro g LPS ml(-1) and no detectable amount of protein. Silver-staining of SDS-PAGE for protein and LPS, dot blot and Western blot analysis and proteinase K and periodate treatment showed that LPS (13-21 kDa and 28 kDa) in our preparation was the relevant antigen for serodiagnosis. IgG antibodies showed reactivity in both leptospiral uveitis patients and controls. However, on the basis of IgM response to LPS, 48 % of the leptospiral uveitis patients were significantly positive compared with controls; 58 % of leptospiral uveitis patients and none of the controls were positive for MAT. When MAT and IgM ELISA results were considered together, 77 % were significantly positive. LPS is identified as a candidate antigen for serodiagnosis of leptospiral uveitis and has sensitivity and specificity of 48 and 90 %, respectively, in ELISA for IgM antibodies. Confirmation of clinical diagnosis with a specific laboratory test would help to initiate the most appropriate treatment for leptospiral uveitis.
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Ethanol inhibits insulin receptor substrate-1 tyrosine phosphorylation and insulin-stimulated neuronal thread protein gene expression. Biochem J 1995; 310 ( Pt 1):125-32. [PMID: 7646434 PMCID: PMC1135863 DOI: 10.1042/bj3100125] [Citation(s) in RCA: 45] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
Neuronal thread proteins (NTPs) are molecules that accumulate in the brains of patients with Alzheimer's disease, and may play a key role in both normal and neurodegenerative neuritic sprouting. In this investigation we determined whether NTP expression is up-regulated by insulin, an important neurotrophic factor that stimulates differentiation-associated neurite outgrowth, and studied the effects of ethanol, a known inhibitor of growth factor receptor tyrosine phosphorylation, on NTP expression and insulin-mediated signal transduction cascade in neuronal [primitive neuroectodermal tumour cell line 2; (PNET2)] cells. PNET2 cells were treated with 50 m-units/ml insulin in the presence or absence of 100 mM ethanol for 0.2-96 h, and cell proliferation and expression of NTP molecules were investigated by metabolic labelling, immunoprecipitation and immunohistochemical staining. Insulin stimulation resulted in an immediate increase in the levels of three (38, 18 and 15 kDa) of five NTP species (the others were of 26 and 21 kDa), followed by a decline in expression within 120 min; however, studies performed up to 96 h of culture demonstrated up-regulation by insulin of all five NTP species. Ethanol either abolished or severely muted the short- and long-term insulin-mediated upregulation of NTP expression, and substantially reduced insulin-mediated neuronal differentiation. The effects of ethanol on NTP gene expression were associated with impaired insulin-mediated tyrosine phosphorylation of both the insulin receptor beta subunit and the insulin receptor substrate-1 (IRS-1), resulting in decreased association of phosphatidylinositol 3-kinase with IRS-1. The findings suggest that ethanol may inhibit NTP expression associated with central nervous system neuronal differentiation by uncoupling the IRS-1-mediated insulin signal transduction pathway.
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Insulin-induced differentiation and modulation of neuronal thread protein expression in primitive neuroectodermal tumor cells is linked to phosphorylation of insulin receptor substrate-1. J Mol Neurosci 1995; 6:91-108. [PMID: 8746448 DOI: 10.1007/bf02736769] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
Neuronal thread proteins (NTPs) are a family of developmentally regulated molecules expressed in central nervous system (CNS) neurons and primitive neuroectodermal tumor (PNET) cell lines. NTP gene expression is modulated with DNA synthesis, neuritic sprouting, and neuronal differentiation. The present study explores the mechanism of insulin modulation of NTP gene expression during neuronal differentiation using PNET cell lines of CNS origin. PNET2 cells underwent neuronal differentiation with neurite outgrowth coupled with transient up-regulation of several species of NTP. In contrast, PNET1 cells failed to differentiate in response to insulin stimulation, although insulin receptors were more abundant than in PNET2 cells. Analysis of the insulin-mediated signal transduction pathway demonstrated that the lack of insulin responsiveness in PNET1 cells was primarily caused by impaired insulin-mediated tyrosyl phosphorylation of the insulin receptor substrate-1 (IRS-1). Correspondingly, the association between phosphatidyl-inositol 3 (PI3) kinase and phosphorylated IRS-1 was reduced in PNET1 compared with PNET2 cells. In contrast, the levels of IRS-1 protein were similar in PNET1 and PNET2 cells, and expression of the insulin receptor beta subunit (Ir beta) and insulin-mediated tyrosyl phosphorylation of the Ir beta were greater in PNET1 than PNET2 cells. The findings suggest that insulin effected neuronal differentiation and modulation of NTP gene expression in PNET cells utilizes a signal transduction cascade that requires tyrosyl phosphorylation of IRS-1.
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A CD4+ T cell line-secreted factor, growth promoting for normal and leukemic B cells, identified as thioredoxin. Int Immunol 1995; 7:625-33. [PMID: 7547690 DOI: 10.1093/intimm/7.4.625] [Citation(s) in RCA: 77] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023] Open
Abstract
In this study, a B cell growth stimulatory factor, constitutively secreted by a human CD4+ T cell hybridoma clone, MP6, has been purified and characterized. Serum-free 24 h culture media from MP6 cells were collected, concentrated by ultrafiltration and separated by gel chromatography. Fractions were analyzed for stimulatory activity using [3H]thymidine incorporation in normal and leukemic (B-CLL) B cells as target cells. Activity was present in a 12 kDa protein peak. Upon storage this lost activity indicating that the factor was sensitive to air oxidation, a well-known property of mammalian thioredoxins (Trxs). Treatment of the inactive fraction with dithiothreitol restored full activity. When culture medium was analyzed with a radioimmunoassay for human placenta Trx, the MP6 clone was shown to release 30-50 ng/ml per million cells during 24 h. The B cell stimulatory activity of the MP6 medium was removed by Sepharose-bound anti-human placenta Trx IgG and activity was recovered by elution from the antibodies. Furthermore, MP6 medium showed Trx activity with NADPH and Trx reductase using an insulin disulfide reduction assay. Starting from 5 l of serum-free MP6 conditioned medium, the Trx was purified approximately 100,000-fold. After gel electrophoresis banding, the material was analyzed by peptide sequencing and a full length sequence of an 104 amino acid long protein was obtained. This Trx sequence was identical to the previously published sequence of human Trx from HTLV-1 transformed T cells, adult T cell leukemia-derived factor/Trx.(ABSTRACT TRUNCATED AT 250 WORDS)
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Effect of ethanol on p36 protein kinase substrate and insulin receptor substrate 1 expression and tyrosyl phosphorylation in human hepatocellular carcinoma cells. Alcohol Clin Exp Res 1995; 19:441-6. [PMID: 7542850 DOI: 10.1111/j.1530-0277.1995.tb01528.x] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
Ethanol inhibits insulin (IN) and epidermal growth factor (EGF)-induced hepatocyte DNA synthesis. Growth factor receptor kinases, such as IN and EGF, phosphorylate insulin receptor substrate (IRS-1) and p36 protein kinase substrate, respectively, on tyrosine residues. IRS-1 and p36 are thought to be important intracellular signal transduction molecules involved in the regulation of cell growth. These investigations explored the effect of ethanol additions on the expression and tyrosyl phosphorylation (TP) of p36 and IRS-1 in a human hepatocellular carcinoma cell line (FOCUS) in relationship to cell proliferation induced by IN and serum growth factor stimulation. It was found that p36 was constitutively and highly expressed in serum-starved cells and protein, and mRNA levels did not change with cell proliferation induced by growth factors. However, exposure of FOCUS cells to ethanol additions substantially inhibited TP of p36. The early TP of IRS-1 induced by IN stimulation was also reduced by ethanol additions. Finally, there was a parallel decrease of FOCUS cell proliferation in ethanol-exposed cultures. These studies suggest that one possible mechanism of ethanol inhibitory effect on cell proliferation is through reduced TP of putative intracellular signal transduction molecules, such as p36 and IRS-1.
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Abstract
p36 is a calcium/lipid-binding phosphoprotein that is expressed at high levels in proliferating and transformed cells, and at low levels in terminally differentiated cells, such as CNS neurons. The calcium-dependent binding to membrane phospholipids, and its capacity to interact with intermediate filament proteins suggest that p36 may be involved in the transduction of extracellular signals. The present work examines p36 gene expression in the mature CNS, primary primitive neuroectodermal tumors (PNETs), and transformed PNET cell lines. p36 immunoreactivity was not observed in normal adult human brain, but low levels of the protein were detected by Western blot analysis. Following acute anoxic cerebral injury, the mean levels of p36 protein were elevated two-fold, and injured neurons exhibited increased p36 immunoreactivity. This phenomenon was likely to have been mediated by post-transcriptional mechanisms since there was no corresponding change in the level p36 mRNA. p36 immunoreactivity was detected in 8 of 9 primary PNETs, and in 3 of 3 neurofilament-expressing PNET cell lines. The levels of p36 protein in PNET cell lines were 5-fold higher than in adult human brain tissue. Although p36 gene expression was generally high in proliferating PNET cells, the levels of p36 mRNA and protein were not strictly correlated with DNA synthesis. Instead, p36 gene expression was modulated in both proliferating and non-proliferating PNET cell cultures by treatment with 50 mIU/ml of insulin, 100 mM ethanol, or 5 microM retinoic acid. The frequent discordances observed experimentally and in vivo between p36 mRNA and p36 protein expression suggest that the steady-state levels of p36 protein in neuronal cells may be regulated primarily by post-transcriptional mechanisms.
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The effect of ethanol and extracellular matrix on induction of p36 protein kinase substrate expression in rat hepatocytes. Biochem Biophys Res Commun 1993; 196:1454-8. [PMID: 7504477 DOI: 10.1006/bbrc.1993.2415] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
p36 plays a direct role in DNA synthesis and is overexpressed in transformed cells. It is also an important component linking the cell membrane to intracellular cytoskeletal components. Experiments were performed in primary rat hepatocyte culture stimulated with epidermal growth factor (EGF) to determine if p36 expression was related to DNA synthesis or to the effect of the extracellular matrix on hepatocyte differentiation; ethanol was employed as an agent to inhibit hormone stimulated hepatocyte DNA synthesis. It was found that hepatocyte p36 expression was highly dependent on the type of extracellular matrix and the time in culture. There was no correlation of p36 expression with DNA synthesis and, therefore, p36 levels appeared more closely related to the differentiated phenotype, induced by the extracellular matrix interactions rather than cellular proliferation.
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Multiple oncogenes and tumor suppressor genes are structurally and functionally intact during hepatocarcinogenesis in hepatitis B virus transgenic mice. Cancer Res 1992; 52:2823-9. [PMID: 1316229] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
In the current study we sought to elucidate the molecular mechanisms which might contribute to hepatocarcinogenesis in a hepatitis B virus (HBV) envelope transgenic mouse model in which chronic hepatocellular injury and inflammation lead to regenerative hyperplasia and eventually to the development of chromosomal abnormalities and hepatocellular carcinoma (HCC), thereby reiterating many of the pathophysiological events that occur prior to the development of HCC in chronic HBV infection in humans. We have previously demonstrated that HBV envelope gene expression is decreased in regenerating hepatocytes and preneoplastic nodules early in the disease process and that expression of alpha-fetoprotein and the multidrug transporter gene mdr-III is activated in the tumors that develop in this model, but not prior to tumor development. In the current study, we examined the structure and expression of a large panel of dominant acting oncogenes and tumor suppressor genes in the liver at all stages of the disease process in order to determine the extent to which they contribute to hepatocarcinogenesis in these transgenic mice. To our surprise, no changes were observed in the structure or function of any of these genes, many of which are commonly activated in other rodent models of hepatocarcinogenesis but rarely activated in human HCC. These findings suggest that the HBV transgenic mouse model is different from most other rodent models of hepatocarcinogenesis and that it may relate more closely to the events involved in HBV-induced human hepatocarcinogenesis, where generalized chromosomal abnormalities are common, while structural and functional changes in most of the commonly studied positive-acting oncogenes examined herein are not. Since p53 and RB mutations have recently been reported to be late events in human hepatocarcinogenesis, the structural integrity of the RB locus and the absence of p53 mutations in the HBV transgenic mouse model suggest that they may represent a relatively early stage of hepatocellular tumorigenesis and that further manipulation of this model is warranted in order to more fully reproduce the molecular-genetic events that characterize HBV-induced HCC in humans.
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MESH Headings
- Animals
- Base Sequence
- Carcinoma, Hepatocellular/genetics
- Carcinoma, Hepatocellular/microbiology
- Disease Models, Animal
- Gene Expression/genetics
- Genes, Retinoblastoma/genetics
- Genes, Tumor Suppressor/genetics
- Genes, myc/genetics
- Genes, p53/genetics
- Genes, ras/genetics
- Hepatitis B virus/genetics
- Liver Neoplasms, Experimental/genetics
- Liver Neoplasms, Experimental/microbiology
- Mice
- Mice, Transgenic
- Molecular Sequence Data
- Oncogenes/genetics
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Preparation and characterization of monoclonal antibodies to nucleocapsid protein N and H glycoprotein of rinderpest virus. Virus Res 1989; 12:331-48. [PMID: 2471370 DOI: 10.1016/0168-1702(89)90091-9] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Fifteen stable mouse spleen cell myeloma hybrids (hybridomas) producing monoclonal antibodies to rinderpest virus proteins were produced. The specificity of these monoclonal antibodies was established by radioimmunoprecipitation followed by polyacrylamide gel analysis and immunofluorescence. Nine antibodies were specific for the surface glycoprotein H. All the nine clones showed inhibition of haemagglutination by measles virus. The antibodies from two clones (A7D2 and B2F6) neutralise infectious virus. Six clones produce antibodies reacting with the nucleocapsid protein N. Three antigenic sites designated I-III, with sites I and II partially overlapping, were topographically mapped on the H molecule by competitive binding assay. Similarly, two antigenic sites I and II were delineated on the N protein. The monoclonal antibodies were used to study the antigenic relationships of H and N proteins of rinderpest virus, measles virus and canine distemper virus.
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