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1.
Article in English | MEDLINE | ID: mdl-37103527

ABSTRACT

BACKGROUND AND OBJECTIVE: Common variable immunodeficiency (CVID) is considered the most symptomatic type of inborn errors of immunity in humans. Along with infectious complications, which have numerous consequences, non-infectious complications are also a major challenge among CVID patients. METHODS: All registered CVID patients in the national database were included in this retrospective cohort study. Patients were divided into two groups based on the presence of B-cell lymphopenia. Demographic characteristics, laboratory findings, non-infectious organ involvements, autoimmunity, and lymphoproliferative diseases were evaluated. RESULTS: Among 387 enrolled patients, 66.4% were diagnosed with non-infectious complications; however, 33.6% had only infectious presentations. Enteropathy, autoimmunity, and lymphoproliferative disorders were reported in 35.1%, 24.3%, and 21.4% of patients, respectively. Some complications, including autoimmunity and hepatosplenomegaly, were reported to be significantly higher among patients with B-cell lymphopenia. Among organ involvement, dermatologic, endocrine and musculoskeletal systems were predominantly affected in CVID patients with B-cell lymphopenia. Among autoimmune manifestations, the frequency of rheumatologic, hematologic, and gastrointestinal autoimmunity was reported to be higher compared to other types of autoimmunity independent from the B cell-lymphopenia. Furthermore, hematological cancers, particularly lymphoma, were slightly introduced as the most common type of malignancy. Meanwhile, the mortality rate was 24.5%, and respiratory failure and malignancies were reported as the most common cause of death in our patients without significant differences between the two groups. CONCLUSION: Considering that some of the non-infectious complications might be associated with B-cell lymphopenia, therefore, regular patient monitoring and follow-up along with proper medications (besides immunoglobulins replacement therapy) are highly recommended to prevent further sequels and increase the patients' quality of life.

2.
Eur Ann Allergy Clin Immunol ; 55(1): 19-28, 2023 01.
Article in English | MEDLINE | ID: mdl-34918886

ABSTRACT

Summary: Background. Inborn errors of immunity (IEIs) are a group of heterogeneous disorders with inherited faults in the immune system that increase susceptibility to infections, malignancies, lymphoproliferation, and autoimmune/autoinflammatory disorders. Methods. We retrospectively studied the demographic characteristics, clinical features, and immunological profiles of the 90 IEIs patients, who were diagnosed and classified according to the European Society for Immunodeficiencies (ESID) and International Union of Immunological Societies (IUIS) criteria from July 2010 to June 2021. The study was carried out in the Non-communicable Diseases Research Center, Imam Ali Hospital, Alborz, Iran. Results. Within a period of 11 years, 53 (58.9%) males and 37 (41.1%) females were diagnosed and followed up for 20 IEI disorders. The median (IQR) age of onset, age of clinical diagnosis and diagnostic delay was 0.7 (0.08-2.0), 3.18 (1.0-8.0) and 1.5 (0.17-5.0) years, respectively. Twelve patients (36.4%) had a positive family history of IEI, and the majority of patients (84.5%) had recurrent infections. Pneumonia (51.7%) was the most common clinical manifestation among IEI patients, followed by skin complications (46.2%). The most frequently diagnosed IEI was immunoglobulin A deficiency (IgAD) (14.4%) and severe combined immunodeficiency (SCID) (11.1%). Predominantly antibody deficiencies group (36.7%) was the most common category, followed by combined immunodeficiencies with associated or syndromic features group (27.8%). Conclusions. IEIs have different patterns within populations with high consanguinity. There is a need to search for underlying genetic and epigenetic factors in most common IEIs in Alborz.


Subject(s)
Immunologic Deficiency Syndromes , Primary Immunodeficiency Diseases , Male , Female , Humans , Retrospective Studies , Iran/epidemiology , Delayed Diagnosis , Immunologic Deficiency Syndromes/diagnosis , Immunologic Deficiency Syndromes/epidemiology , Immunologic Deficiency Syndromes/genetics
3.
Arch Razi Inst ; 76(3): 529-536, 2021.
Article in English | MEDLINE | ID: mdl-34824746

ABSTRACT

Leishmaniasis causes parasitic infections, especially in developing countries. The disease has not yet been controlled because of the absence of an effective vaccine and low-cost treatment. Achillea santolina essential oil (ASEO) might control the disease as it has antimicrobial properties. This study investigated the in vitro antileishmanial activity of ASEO against Leishmania infantum promastigote using the methylthiazole tetrazolium (MTT) and trypan blue colorimetric methods. The standard strain of L. infantum (MCAN/IR/96/LON49) promastigotes was prepared and cultured in a 96-well Novy-MacNeal-Nicolle (NNN) medium. The effects of different concentrations of saline, ASEO, and glucantime (10, 50, 100, 200, 500, and 1000 mg/mL) were examined in 24-, 48-, and 72-hour intervals using the MTT and trypan blue test methods.The use of ASEO reduced viability in all concentrations compared to the control group in times of 48 (p<0.05) and 72 h (p<0.05). Treatment with glucantime and ASEO had similar efficiency with the concentration of 1000 mL/mg in both methods after 72 h. The results showed that viability was significantly lower in the ASEO group with increases in time using both methods (p<0.05). Cohen's Kappa coefficient showed a significant agreement between the obtained results for the two methods (Kappa=0.856; p<0.001).In sum, the results showed in vitro antileishmanial activity of ASEO, but more clinical studies are needed to confirm the efficiency. ASEO can be used as an agent and/or in combination with synthetic agents for the treatment of leishmaniasis disease.


Subject(s)
Achillea , Leishmania infantum , Oils, Volatile , Colorimetry , Oils, Volatile/pharmacology , Trypan Blue
4.
Dev Biol ; 480: 1-12, 2021 12.
Article in English | MEDLINE | ID: mdl-34363825

ABSTRACT

Cardiac trabeculae are muscular ridge-like structures within the ventricular wall that are crucial for cardiac function. In zebrafish, these structures first form primarily through the delamination of compact wall cardiomyocytes (CMs). Although defects in proteasomal degradation have been associated with decreased cardiac function, whether they also affect cardiac development has not been extensively analyzed. Here we report a role during cardiac wall morphogenesis in zebrafish for the E3 ubiquitin-protein ligase Rbx1, which has been shown to regulate the degradation of key signaling molecules. Although development is largely unperturbed in zebrafish rbx1 mutant larvae, they exhibit CM multi-layering. This phenotype is not affected by blocking ErbB signaling, but fails to manifest itself in the absence of blood flow/cardiac contractility. Surprisingly, rbx1 mutants display ErbB independent Notch reporter expression in the myocardium. We generated tissue-specific rbx1 overexpression lines and found that endothelial, but not myocardial, specific rbx1 expression normalizes the cardiac wall morphogenesis phenotype. In addition, we found that pharmacological activation of Hedgehog signaling ameliorates the multi-layered myocardial wall phenotype in rbx1 mutants. Collectively, our data indicate that endocardial activity of Rbx1 is essential for cardiac wall morphogenesis.


Subject(s)
Myocardium/metabolism , Ubiquitin-Protein Ligases/metabolism , Animals , Cell Proliferation/genetics , Endocardium/metabolism , Endothelium/metabolism , Gene Expression/genetics , Gene Expression Regulation/genetics , Genes, erbB/genetics , Heart/physiology , Heart Ventricles/metabolism , Hedgehog Proteins/metabolism , Morphogenesis/genetics , Myocardial Contraction , Myocytes, Cardiac/metabolism , Organogenesis/genetics , Receptors, Notch/genetics , Receptors, Notch/metabolism , Signal Transduction/genetics , Ubiquitin-Protein Ligases/genetics , Zebrafish/genetics , Zebrafish/metabolism , Zebrafish Proteins/genetics , Zebrafish Proteins/metabolism
5.
Allergol. immunopatol ; 47(5): 491-498, sept.-oct. 2019. tab, graf
Article in English | IBECS | ID: ibc-186524

ABSTRACT

Background: Mendelian susceptibility to mycobacterial disease (MSMD) is characterized by increased susceptibility to weakly virulent mycobacteria (Bacillus Calmette-Guérin [BCG] vaccines and environmental mycobacteria), Mycobacterium tuberculosis, Candida spp. and Salmonella spp. The aim of this study is to evaluate clinical features and immunological findings of MSMD patients with interleukin 12 receptor beta 1 (IL12Rβ1) deficiency. Methods: Among 117 screened patients with BCG infection following vaccination, 23 suspected MSMD subjects were recruited to this study by the exclusion of severe combined immunodeficiencies and chronic granulomatous diseases. Flow cytometric assessment for surface expression of IL12Rβ1 was performed. Moreover, the clinical and immunological data from the patients was evaluated. Results: A significant decrease (less than 1%) in the surface expression of IL12Rβ1 was reported in six cases which showed a significant increase in the count of lymphocytes (p = 0.009) and CD8+ T cells (p = 0.008) as compared to MSMD subjects with normal expression of surface IL12Rβ1. The frequency of disseminated BCGosis (50% vs. 20%, p = 0.29), recurrent infection (83.3% vs. 40%, p = 0.14) and salmonellosis (33.3% vs. 0.0%, p = 0.07) was higher in IL12Rβ1 deficient subjects than IL12Rβ1 sufficient individuals. Conclusion: MSMD patients with childhood onset of mycobacteriosis (mostly after BCG vaccination) and recurrent salmonellosis could be evaluated for IL12Rβ1 expression with flow cytometry for punctual diagnosis


No disponible


Subject(s)
Humans , Male , Female , Child, Preschool , Child , Adolescent , Herpes Simplex/immunology , Immunologic Deficiency Syndromes/immunology , Mutation/genetics , Mycobacterium bovis/immunology , Mycobacterium Infections, Nontuberculous/immunology , Simplexvirus/physiology , Receptors, Interleukin-12/genetics , Genetic Predisposition to Disease , Herpes Simplex/genetics , Immunologic Deficiency Syndromes/genetics , Mycobacterium Infections, Nontuberculous/genetics , Prospective Studies , Receptors, Interleukin-12/metabolism
6.
Allergol Immunopathol (Madr) ; 47(5): 491-498, 2019.
Article in English | MEDLINE | ID: mdl-31350062

ABSTRACT

BACKGROUND: Mendelian susceptibility to mycobacterial disease (MSMD) is characterized by increased susceptibility to weakly virulent mycobacteria (Bacillus Calmette-Guérin [BCG] vaccines and environmental mycobacteria), Mycobacterium tuberculosis, Candida spp. and Salmonella spp. The aim of this study is to evaluate clinical features and immunological findings of MSMD patients with interleukin 12 receptor beta 1 (IL12Rß1) deficiency. METHODS: Among 117 screened patients with BCG infection following vaccination, 23 suspected MSMD subjects were recruited to this study by the exclusion of severe combined immunodeficiencies and chronic granulomatous diseases. Flow cytometric assessment for surface expression of IL12Rß1 was performed. Moreover, the clinical and immunological data from the patients was evaluated. RESULTS: A significant decrease (less than 1%) in the surface expression of IL12Rß1 was reported in six cases which showed a significant increase in the count of lymphocytes (p=0.009) and CD8+ T cells (p=0.008) as compared to MSMD subjects with normal expression of surface IL12Rß1. The frequency of disseminated BCGosis (50% vs. 20%, p=0.29), recurrent infection (83.3% vs. 40%, p=0.14) and salmonellosis (33.3% vs. 0.0%, p=0.07) was higher in IL12Rß1 deficient subjects than IL12Rß1 sufficient individuals. CONCLUSION: MSMD patients with childhood onset of mycobacteriosis (mostly after BCG vaccination) and recurrent salmonellosis could be evaluated for IL12Rß1 expression with flow cytometry for punctual diagnosis.


Subject(s)
Herpes Simplex/immunology , Immunologic Deficiency Syndromes/immunology , Mutation/genetics , Mycobacterium Infections, Nontuberculous/immunology , Mycobacterium bovis/immunology , Receptors, Interleukin-12/genetics , Simplexvirus/physiology , Adolescent , Child , Child, Preschool , Female , Genetic Predisposition to Disease , Herpes Simplex/genetics , Humans , Immunologic Deficiency Syndromes/genetics , Infant , Male , Mycobacterium Infections, Nontuberculous/genetics , Prospective Studies , Receptors, Interleukin-12/metabolism
7.
Development ; 145(14)2018 07 30.
Article in English | MEDLINE | ID: mdl-30061167

ABSTRACT

Cardiomyocyte proliferation is crucial for cardiac growth, patterning and regeneration; however, few studies have investigated the behavior of dividing cardiomyocytes in vivo Here, we use time-lapse imaging of beating hearts in combination with the FUCCI system to monitor the behavior of proliferating cardiomyocytes in developing zebrafish. Confirming in vitro observations, sarcomere disassembly, as well as changes in cell shape and volume, precede cardiomyocyte cytokinesis. Notably, cardiomyocytes in zebrafish embryos and young larvae mostly divide parallel to the myocardial wall in both the compact and trabecular layers, and cardiomyocyte proliferation is more frequent in the trabecular layer. While analyzing known regulators of cardiomyocyte proliferation, we observed that the Nrg/ErbB2 and TGFß signaling pathways differentially affect compact and trabecular layer cardiomyocytes, indicating that distinct mechanisms drive proliferation in these two layers. In summary, our data indicate that, in zebrafish, cardiomyocyte proliferation is essential for trabecular growth, but not initiation, and set the stage to further investigate the cellular and molecular mechanisms driving cardiomyocyte proliferation in vivo.


Subject(s)
Myocytes, Cardiac/cytology , Organogenesis , Zebrafish/growth & development , Animals , Cell Division , Cell Proliferation , Cell Shape , Cell Size , Gene Expression Regulation, Developmental , Heart/growth & development , Ligands , Myocytes, Cardiac/metabolism , Sarcomeres/metabolism , Signal Transduction , Transforming Growth Factor beta/metabolism , Zebrafish/genetics , Zebrafish Proteins/metabolism
8.
Ultramicroscopy ; 194: 25-34, 2018 11.
Article in English | MEDLINE | ID: mdl-30056278

ABSTRACT

Transmission electron microscopy (TEM) represents a unique and powerful modality for capturing spatial features of nanoparticles, such as size and shape. However, poor statistics arise as a key obstacle, due to the challenge in accurately and automatically segmenting nanoparticles in TEM micrographs. Towards remedying this deficit, we introduce an automatic particle picking device that is based on the concept of variance hybridized mean local thresholding. Validation of this new segmentation model is accomplished by applying a program written in Matlab to a database of 150 bright field TEM micrographs containing approximately 2,000 nanoparticles. We compare the results to global thresholding, local thresholding, and manual segmentation. It is found that this novel automatic particle picking device reduces false positives and false negatives significantly, while increasing the number of individual particles picked on regions of particle overlap.

9.
Nat Commun ; 8(1): 1902, 2017 12 01.
Article in English | MEDLINE | ID: mdl-29196619

ABSTRACT

Zebrafish regenerate damaged myocardial tissue very effectively. Hence, insights into the molecular networks underlying zebrafish heart regeneration might help develop alternative strategies to restore human cardiac performance. While TGF-ß signaling has been implicated in zebrafish cardiac regeneration, the role of its individual ligands remains unclear. Here, we report the opposing expression response during zebrafish heart regeneration of two genes, mstnb and inhbaa, which encode TGF-ß family ligands. Using gain-of-function (GOF) and loss-of-function (LOF) approaches, we show that these ligands mediate inverse effects on cardiac regeneration and specifically on cardiomyocyte (CM) proliferation. Notably, we find that Inhbaa functions as a CM mitogen and that its overexpression leads to accelerated cardiac recovery and scar clearance after injury. In contrast, mstnb GOF and inhbaa LOF both lead to unresolved scarring after cardiac injury. We further show that Mstnb and Inhbaa inversely control Smad2 and Smad3 transcription factor activities through alternate Activin type 2 receptors.


Subject(s)
Activin Receptors, Type II/metabolism , Cell Proliferation , Inhibin-beta Subunits/metabolism , Myocytes, Cardiac/cytology , Myocytes, Cardiac/metabolism , Myostatin/metabolism , Zebrafish Proteins/metabolism , Zebrafish/metabolism , Activin Receptors, Type II/genetics , Animals , Female , Heart/growth & development , Heart/physiology , Inhibin-beta Subunits/genetics , Ligands , Male , Myostatin/genetics , Regeneration , Smad2 Protein/genetics , Smad2 Protein/metabolism , Smad3 Protein/genetics , Smad3 Protein/metabolism , Zebrafish/genetics , Zebrafish/growth & development , Zebrafish Proteins/genetics
10.
Nat Commun ; 8: 15281, 2017 05 09.
Article in English | MEDLINE | ID: mdl-28485381

ABSTRACT

Trabeculation is crucial for cardiac muscle growth in vertebrates. This process requires the Erbb2/4 ligand Neuregulin (Nrg), secreted by the endocardium, as well as blood flow/cardiac contractility. Here, we address two fundamental, yet unresolved, questions about cardiac trabeculation: why does it initially occur in the ventricle and not the atrium, and how is it modulated by blood flow/contractility. Using loss-of-function approaches, we first show that zebrafish Nrg2a is required for trabeculation, and using a protein-trap line, find that it is expressed in both cardiac chambers albeit with different spatiotemporal patterns. Through gain-of-function experiments, we show that atrial cardiomyocytes can also respond to Nrg2a signalling, suggesting that the cardiac jelly, which remains prominent in the atrium, represents a barrier to Erbb2/4 activation. Furthermore, we find that blood flow/contractility is required for Nrg2a expression, and that while non-contractile hearts fail to trabeculate, non-contractile cardiomyocytes are also competent to respond to Nrg2a/Erbb2 signalling.


Subject(s)
Myocytes, Cardiac/metabolism , Organogenesis , Signal Transduction , Zebrafish Proteins/metabolism , Zebrafish/metabolism , Animals , Animals, Genetically Modified , Coronary Circulation , Embryo, Nonmammalian/metabolism , Heart Atria/cytology , Heart Atria/embryology , Heart Ventricles/embryology , Heart Ventricles/metabolism , Larva/growth & development , Larva/metabolism , Mutation/genetics , Recombinant Fusion Proteins/metabolism , Zebrafish/embryology
11.
Cell Rep ; 17(10): 2687-2699, 2016 12 06.
Article in English | MEDLINE | ID: mdl-27926871

ABSTRACT

Despite great strides in understanding cardiac trabeculation, many mechanistic aspects remain unclear. To elucidate how cardiomyocyte shape changes are regulated during this process, we engineered transgenes to label their apical and basolateral membranes. Using these tools, we observed that compact-layer cardiomyocytes are clearly polarized while delaminating cardiomyocytes have lost their polarity. The apical transgene also enabled the imaging of cardiomyocyte apical constriction in real time. Furthermore, we found that Neuregulin signaling and blood flow/cardiac contractility are required for cardiomyocyte apical constriction and depolarization. Notably, we observed the activation of Notch signaling in cardiomyocytes adjacent to those undergoing apical constriction, and we showed that this activation is positively regulated by Neuregulin signaling. Inhibition of Notch signaling did not increase the percentage of cardiomyocytes undergoing apical constriction or of trabecular cardiomyocytes. These studies provide information about cardiomyocyte polarization and enhance our understanding of the complex mechanisms underlying ventricular morphogenesis and maturation.


Subject(s)
Epithelial-Mesenchymal Transition/genetics , Molecular Imaging , Myocardial Contraction/genetics , Myocytes, Cardiac/metabolism , Neuregulin-1/genetics , Animals , Animals, Genetically Modified , Cell Polarity/genetics , Humans , Morphogenesis/genetics , Myocytes, Cardiac/pathology , Myocytes, Cardiac/ultrastructure , Organogenesis/genetics , Receptors, Notch/genetics , Signal Transduction , Transgenes , Zebrafish/genetics , Zebrafish Proteins/genetics
12.
Nat Commun ; 7: 11805, 2016 06 01.
Article in English | MEDLINE | ID: mdl-27248505

ABSTRACT

Endothelial cells (ECs) respond to shear stress by aligning in the direction of flow. However, how ECs respond to flow in complex in vivo environments is less clear. Here we describe an endothelial-specific transgenic zebrafish line, whereby the Golgi apparatus is labelled to allow for in vivo analysis of endothelial polarization. We find that most ECs polarize within 4.5 h after the onset of vigorous blood flow and, by manipulating cardiac function, observe that flow-induced EC polarization is a dynamic and reversible process. Based on its role in EC migration, we analyse the role of Apelin signalling in EC polarization and find that it is critical for this process. Knocking down Apelin receptor function in human primary ECs also affects their polarization. Our study provides new tools to analyse the mechanisms of EC polarization in vivo and reveals an important role in this process for a signalling pathway implicated in cardiovascular disease.


Subject(s)
Apelin Receptors/genetics , Apelin/genetics , Cell Polarity , Chemokines/genetics , Zebrafish Proteins/genetics , Animals , Animals, Genetically Modified , Apelin/metabolism , Apelin Receptors/metabolism , Biomechanical Phenomena , Cell Movement , Chemokines/metabolism , Embryo, Nonmammalian , Gene Expression Regulation, Developmental , Golgi Apparatus/metabolism , Hemorheology , Human Umbilical Vein Endothelial Cells/metabolism , Human Umbilical Vein Endothelial Cells/ultrastructure , Humans , In Situ Hybridization, Fluorescence , Larva/genetics , Larva/growth & development , Larva/metabolism , Signal Transduction , Stress, Mechanical , Zebrafish , Zebrafish Proteins/metabolism
13.
Drug Deliv ; 21(3): 155-63, 2014 May.
Article in English | MEDLINE | ID: mdl-24107075

ABSTRACT

The objective of this study was to develop pH-responsive silica nanoparticles by imidazole-based ionic liquid for controlled release of methotrexate. In this article, we synthesized pH-responsive cationic silica nanoparticles by graft copolymerization of vinyl functionalized silica nanoparticles and methacrylic acid (MAA) monomer. Imidazole-based ionic liquid (Im-IL) was verified by (1)HNMR and Fourier-transform infrared (FTIR) spectroscopy. The synthesized functionalized silica particles were characterized and confirmed by various technologies including the scanning electron microscopy (SEM), the infrared spectroscopy (IR) and the thermogravimetric analysis (TGA). SEM results reveal the uniformity in size/shape of silica particles. This nanosystem is modified for targeted delivery of an anticancer agent methotrexate. The nanocomposite-MTX complex was formed at physiological pH (7.4) due to the electrostatic interactions between anionic carboxylic group of MTX molecules and cationic rings in carrier, while, the release of which can be achieved through the cleavage of the nanocomposite-MTX complex by protonation of carboxyl groups in the MTX segment that are sensitive to variations in external pH at weak acidic conditions. FT-IR spectroscopy showed the presence of light interactions between the silicate silanols and the drug. MCF7 cells were incubated with the MTX-free nanocomposite and MTX-loaded nanocomposite at various concentrations for 24, 48 and 72 h, and the data showed that the nanocomposites themselves did not affect the growth of MCF7 cells. Antitumor activity of the MTX-loaded nanocomposites against the cells was kept over the whole experiment process. The results showed that the MTX could be released from the fibers without losing cytotoxicity.


Subject(s)
Antimetabolites, Antineoplastic/chemistry , Biocompatible Materials , Drug Carriers , Methotrexate/chemistry , Nanocomposites , Polymethacrylic Acids/chemical synthesis , Silicon Dioxide/chemical synthesis , Antimetabolites, Antineoplastic/pharmacology , Cell Proliferation/drug effects , Cell Survival/drug effects , Chemistry, Pharmaceutical , Delayed-Action Preparations , Dose-Response Relationship, Drug , Humans , Hydrogen-Ion Concentration , Imidazoles/chemistry , MCF-7 Cells , Methotrexate/pharmacology , Microscopy, Electron, Scanning , Nanotechnology , Polymethacrylic Acids/toxicity , Proton Magnetic Resonance Spectroscopy , Silicon Dioxide/toxicity , Solubility , Spectroscopy, Fourier Transform Infrared , Technology, Pharmaceutical/methods , Thermogravimetry , Time Factors
14.
Biochem Biophys Res Commun ; 395(4): 577-82, 2010 May 14.
Article in English | MEDLINE | ID: mdl-20399743

ABSTRACT

Recent studies have shown that heterotrimeric G proteins are involved in the regulation of the canonical Wnt/beta-Catenin pathway. However, the mechanism(s) behind this involvement is (are) poorly understood. Our previous results have shown that activation of Galphaq in Xenopus oocytes leads to inhibition of GSK-3beta and stabilization of the beta-Catenin protein, suggesting that Galphaq might stabilize beta-Catenin via inhibition of GSK-3beta. In this study, we have observed similar results in HEK293T cells. In these cells optimal activation of endogenous Galphaq by expressing M3-muscarinic acetylcholine receptor (with or without carbachol treatment), or exposing the cells to thrombin led to an increase of 2 to 3-fold in endogenous cytoplasmic beta-Catenin protein levels. In addition, expression of the activated mutant of Galphaq (GalphaqQL) dramatically enhanced accumulation of exogenous beta-Catenin with no effect on beta-catenin (CTNNB1) gene transcription. The Galphaq-mediated cellular accumulation of beta-Catenin was blocked by expression of a minigene encoding a Galphaq specific inhibitory peptide but not by a minigene encoding a Galphas blocking peptide. Also, expression of GalphaqQL led to a significant reduction in GSK-3beta kinase activity, supporting the idea that the positive role of Galphaq signaling in inducing cellular accumulation of beta-Catenin is mediated through inhibition of GSK-3beta.


Subject(s)
GTP-Binding Protein alpha Subunits, Gq-G11/metabolism , Glycogen Synthase Kinase 3/metabolism , Wnt Proteins/metabolism , beta Catenin/metabolism , Cell Line , GTP-Binding Protein alpha Subunits, Gq-G11/genetics , Glycogen Synthase Kinase 3/antagonists & inhibitors , Glycogen Synthase Kinase 3/genetics , Glycogen Synthase Kinase 3 beta , Humans , Receptor, Muscarinic M3/agonists , Receptor, Muscarinic M3/biosynthesis , Transcription, Genetic , beta Catenin/genetics
15.
J Chromatogr A ; 923(1-2): 119-26, 2001 Jul 20.
Article in English | MEDLINE | ID: mdl-11510534

ABSTRACT

The simplest field flow fractionation technique, which uses the earth's gravity as the external field is applied to isolate two populations, which differ in both shape and size, from a polydisperse sub-micron TiO2 powder of homogenous density. The fraction eluted first is spherical with an average diameter of 0.31 microm while the second fraction is ellipsoidal and can be associated with a 0.45 microm hydrodynamic diameter. Elution conditions appeared to be very sensitive to electrolyte and surfactant characteristics in the carrier phase as well as on the sample concentration. Using 25 microl (1%, w/w) sample suspension, separations of spherical from ovoid particles was performed in almost 2 h with a mobile phase of 0.001 M KNO3-0.01% (v/v) Fl-70 in water in a 0.025-cm thick channel made of polystyrene walls.


Subject(s)
Chemical Fractionation/methods , Titanium/isolation & purification , Gravitation , Particle Size
16.
J Chromatogr B Biomed Sci Appl ; 754(1): 11-21, 2001 Apr 15.
Article in English | MEDLINE | ID: mdl-11318404

ABSTRACT

Field flow fractionation (FFF) separation techniques have gained considerable success with micron-sized species. Living red blood cells (RBCs) of any origin have emerged as ideal models for cell separation development. Their elution mode is now described as "Lift-Hyperlayer". Certain separator dimension parameters are known to play a key role in the separation and band spreading process. Systematic studies of channel dimensions effects on RBC retention, band spreading, peak capacity and on a novel parameter described as "Particle Selectivity" were set up by means of a two-level factorial experimental design. From experimental results and statistical calculations it is confirmed that channel thickness plays a major role in retention ratio, peak variance, peak capacity and particle selectivity. Channel breadth strongly influences plate height, with lower impact on peak capacity and particle selectivity. Retention ratio, peak variance and peak capacity observed results are modulated by second-order interactions between channel dimensions. Preliminary rules for channel configurations are therefore set up and depend on separation goals. It is shown that a very polydisperse population is best disentangled in a thin and narrow channel whatever its length. If a mixture of many different micron-sized species is considered (each of limited polydispersities); a thick and broad channel should be preferred, with length modulating peak capacity to disentangle this polymodal mixture.


Subject(s)
Cell Separation/methods , Erythrocytes/chemistry , Humans , Models, Statistical , Research Design , Rheology
17.
J Chromatogr A ; 905(1-2): 163-73, 2001 Jan 05.
Article in English | MEDLINE | ID: mdl-11206783

ABSTRACT

Sedimentation field flow fractionation (SdFFF) operated at multi gravitational field is used to analyse a highly polydisperse TiO2 colloidal suspension. From the initial sample, time dependent eluted fractions are collected and submitted to electron microscopy (EM) shape and size analysis. To assess the accuracy of FFF in determining the average size of the different fractions, these are re-introduced into the channel by means of two different procedures, the on-channel concentration of the fractions and the direct re-injection of pre-concentrated fractions (DRI). Both methods appear accurate to determine the average size of every fraction, associated to a lower recovery in the case of DRI. The fractogram band spreading characteristics of the re-introduced fractions are correlated to the particle size distribution measured by EM. After density determination of fractionated particles, the fractogram is calibrated in terms of size and size distribution using data obtained from EM for each fraction. Quantitative analyses, based on particle counting showed high recovery (80-90%) of the eluted species. However, this loss limited the possibility to extend signal information to a quantitative one.


Subject(s)
Titanium/chemistry , Chemical Fractionation , Microscopy, Electron
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