Your browser doesn't support javascript.
loading
Montrer: 20 | 50 | 100
Résultats 1 - 20 de 27
Filtrer
Plus de filtres










Base de données
Gamme d'année
1.
J Fungi (Basel) ; 9(5)2023 May 12.
Article de Anglais | MEDLINE | ID: mdl-37233271

RÉSUMÉ

Coccidioides species are thermally dimorphic fungi found in geographically defined areas of the Western Hemisphere. The primary portal of entry is respiratory, with symptomatic pneumonic diseases as the most common presentation. Subsequent pulmonary complications as well as extrapulmonary metastatic infection may occur, either of which may be the presenting disease manifestation. Cavitary lung disease may be found incidentally or when investigating symptoms such as cough or hemoptysis. This study aims to explore the spectrum of coccidioidal cavities and the evaluation and management in a cohort of patients seen at Kern Medical over the last 12 years.

2.
JAMA Cardiol ; 8(4): 405, 2023 04 01.
Article de Anglais | MEDLINE | ID: mdl-36811870

RÉSUMÉ

This case report describes a 63-year-old male patient with a native bypass of the left coronary artery found incidentally while undergoing computed tomography angiography of the coronary arteries for clinical research purposes.


Sujet(s)
Maladie des artères coronaires , Humains , Mâle , Maladie des artères coronaires/chirurgie , Pontage aortocoronarien
3.
J Investig Med High Impact Case Rep ; 10: 23247096221077832, 2022.
Article de Anglais | MEDLINE | ID: mdl-35240889

RÉSUMÉ

In systemic lupus erythematosus (SLE), cardiac manifestations are known to be present in up to 50% of patients. However, it is rare for acute pericarditis to be the leading symptom at the time of diagnosis of SLE occurring in up to 1% of patients. We present a case series in which 3 patients with no prior history of SLE presented with acute pericarditis. This was found to be the leading manifestation of their disease, which ultimately led to the diagnosis of SLE. These patients were initially treated with nonsteroidal anti-inflammatory drugs and colchicines; however, steroids and disease-modifying anti-rheumatologic agents were ultimately added to their medical therapy.


Sujet(s)
Lupus érythémateux disséminé , Péricardite , Humains , Lupus érythémateux disséminé/complications , Lupus érythémateux disséminé/diagnostic , Péricardite/diagnostic , Péricardite/étiologie
4.
J Investig Med High Impact Case Rep ; 10: 23247096221084852, 2022.
Article de Anglais | MEDLINE | ID: mdl-35354329

RÉSUMÉ

Coccidioidomycosis (CM) is a fungal disease that results from inhalation of spores of Coccidioides immitis and C posadasii. If symptomatic, disease primarily manifests as community-acquired pneumonia; however, additional pulmonary manifestations such as pleural effusion, empyema, and cavitation may occur. Diabetic patients have an increased risk of severe and cavitary CM. Cavitary disease may erode vasculature and pulmonary parenchyma leading to further complications. Furthermore, chronic cavities can become colonized as well and develop superimposed infections. This is a case of cavitary CM in uncontrolled diabetic nonadherent to treatment presenting with hemoptysis and mycetoma.


Sujet(s)
Coccidioïdomycose , Mycoses pulmonaires , Coccidioides , Coccidioïdomycose/complications , Coccidioïdomycose/diagnostic , Coccidioïdomycose/microbiologie , Hémoptysie/étiologie , Humains , Poumon , Mycoses pulmonaires/diagnostic , Mycoses pulmonaires/imagerie diagnostique
5.
Open Forum Infect Dis ; 9(3): ofac017, 2022 Mar.
Article de Anglais | MEDLINE | ID: mdl-35169589

RÉSUMÉ

Coccidioidomycosis is the second most common endemic fungal infection in the United States. Prior descriptions of coccidioidal peritonitis include only single cases. We describe 17 new cases previously unreported from healthcare institutions in California. The majority of cases presented with nonspecific abdominal complaints. PubMed and Google Scholar were searched for additional case series and only single case reports and reviews of single cases were found. The diagnosis was confirmed by culture or histopathology and/or serology in each patient. All patients were treated with anti-fungal therapy. This case series demonstrates that coccidioidal peritonitis may be asymptomatic or present with only subtle abdominal symptoms. In a minority of our patients, the diagnosis was established incidentally during surgery. Based on this series, the overall outcome of coccidioidal peritonitis is favorable with long-term triazole treatment. The term cure is not usually used in disseminated coccidioidal disease because of the risk of late relapse.

6.
Cureus ; 13(7): e16170, 2021 Jul.
Article de Anglais | MEDLINE | ID: mdl-34268059

RÉSUMÉ

Background Methamphetamine use is associated with cardiovascular disease and significant morbidity and mortality. There is only one previous study performed on echocardiographic parameters in patients with methamphetamine cardiomyopathy. Methods We performed a retrospective review of medical records in a county hospital in Southern California with a high population of methamphetamine users. We reviewed medical records and echocardiogram findings in patients seen in our institution from November 2019 to November 2020 who had cardiomyopathy with and without methamphetamine use. We excluded patients who either left the hospital or expired before appropriate assessment. We divided our patient population into a case group (methamphetamine users) and a control group (non-methamphetamine users) to study and compare their echocardiographic parameters. Results Case group included a total of 254 patients and control group included 268 patients. Majority of the patient population were males - 178 (70%) and 180 (67%) in the case and control group respectively. Age was found to be statistically significant with the younger population in the case group (p = 0.0000). Our analysis revealed statistically significant difference in methamphetamine users compared to non-users in regards to left ventricle ejection fraction (33.65% ± 18.02 vs. 41.55% ± 15.61, p=0.0000), left ventricle mass index (122.49 grams/m2 ± 40.66 vs. 108.62 grams/m2 ± 32.82, p=0.0000), left ventricle end diastolic volume index (85.91 mL/m2 ± 37.40 vs. 72.44 mL/m2 ± 25.44; p=0.0000) and marginally significant right ventricle systolic pressure (42.29mmHg ± 17.53 vs. 39.59mmHg ± 15.61; p=0.0540) Conclusion Our results indicated that methamphetamine users had echocardiogram findings with decreased ejection fraction and increased left ventricular mass index, end-diastolic volume index, and right ventricular systolic pressure consistent with worse dilated cardiomyopathy comparison to non-users.

7.
J Investig Med High Impact Case Rep ; 9: 23247096211035238, 2021.
Article de Anglais | MEDLINE | ID: mdl-34293944

RÉSUMÉ

Drugs account for 2% of all the causes of acute pancreatitis. To date, there are approximately 26 reported cases of acute pancreatitis associated with the use of cannabis. We report the case of a 20-year-old male who presented with intractable nausea, vomiting, and epigastric pain and a lipase level of 1541 with reportedly no alcohol use, and no evidence of medication, biliary, or autoimmune etiology. However, the patient did endorse heavily smoking cannabis prior to symptom onset. He was instructed to abstain from cannabis use on discharge and has not presented to the hospital since this episode. The reporting of this case aims to increase awareness of cannabis as a differential diagnosis in cases of pancreatitis that is not due to typical etiologies such as gallstones, medications, and alcohol use. There has yet to be definitive evidence as to how cannabis can cause pancreatitis. Further studies must be conducted to better understand the association between cannabis use and acute pancreatitis and the mechanism by which cannabis affects the pancreas.


Sujet(s)
Cannabis , Pancréatite , Douleur abdominale , Maladie aigüe , Adulte , Cannabis/effets indésirables , Diagnostic différentiel , Humains , Pancréatite/induit chimiquement , Jeune adulte
8.
Chem Sci ; 13(1): 210-217, 2021 Dec 22.
Article de Anglais | MEDLINE | ID: mdl-35059169

RÉSUMÉ

We demonstrate phage-display screening on self-assembled ligands that enables the identification of oligopeptides that selectively bind dynamic supramolecular targets over their unassembled counterparts. The concept is demonstrated through panning of a phage-display oligopeptide library against supramolecular tyrosine-phosphate ligands using 9-fluorenylmethoxycarbonyl-phenylalanine-tyrosine-phosphate (Fmoc-FpY) micellar aggregates as targets. The 14 selected peptides showed no sequence consensus but were enriched in cationic and proline residues. The lead peptide, KVYFSIPWRVPM-NH2 (P7) was found to bind to the Fmoc-FpY ligand exclusively in its self-assembled state with K D = 74 ± 3 µM. Circular dichroism, NMR and molecular dynamics simulations revealed that the peptide interacts with Fmoc-FpY through the KVYF terminus and this binding event disrupts the assembled structure. In absence of the target micellar aggregate, P7 was further found to dynamically alternate between multiple conformations, with a preferred hairpin-like conformation that was shown to contribute to supramolecular ligand binding. Three identified phages presented appreciable binding, and two showed to catalyze the hydrolysis of a model para-nitro phenol phosphate substrate, with P7 demonstrating conformation-dependent activity with a modest k cat/K M = 4 ± 0.3 × 10-4 M-1 s-1.

9.
J Investig Med High Impact Case Rep ; 8: 2324709620966855, 2020.
Article de Anglais | MEDLINE | ID: mdl-33054423

RÉSUMÉ

Vasculitis is an inflammatory process involving blood vessels of various sizes, including the small vessels in the kidneys to the large vessels, such as the aorta. This inflammatory condition is usually autoimmune in nature and is associated with involvement of many locations, such as the sinuses, lungs, kidneys, and even the heart. Specifically, eosinophilic granulomatosis with polyangiitis (EGPA) is a systemic vasculitis that may initially hide as asthma, allergic rhinitis, and/or sinusitis. However, it is known to become a lethal disease once progressed to include cardiovascular manifestations. It is important to remember EGPA as a differential for any patient with a history of asthma, allergic rhinitis, and/or sinusitis who also presents with cardiovascular complaints and eosinophilia. Treatment recommendations focus on immunosuppression in such cases. In this article, we discuss the case of a 62-year-old male, with a known history of asthma, who presented to the emergency department with concern for his chest pain and right-sided weakness. He was later diagnosed with EGPA with eosinophilic myocarditis. Diagnosis and treatment are described.


Sujet(s)
Syndrome de Churg-Strauss/complications , Myocardite/complications , Syndrome de Churg-Strauss/traitement médicamenteux , Diagnostic différentiel , Humains , Immunosuppresseurs/usage thérapeutique , Mâle , Adulte d'âge moyen , Myocardite/traitement médicamenteux ,
10.
J Investig Med High Impact Case Rep ; 8: 2324709620959880, 2020.
Article de Anglais | MEDLINE | ID: mdl-32935587

RÉSUMÉ

Cryptococcus gattii is a species that has received more recognition in the recent past as distinct from Cryptococcus neoformans. C gattii is known to cause meningeal disease in both immunocompetent and immunosuppressed hosts. Patients may be clinically asymptomatic until immunosuppressive conditions occur such as corticosteroid treatment or an HIV infection. HIV-associated cryptococcal infections are most often due to C neoformans. C gattii is found in a minority. Speciation and subtyping of Cryptococcus are not always accomplished. In many parts of the world, there is no availability for speciation of Cryptococcus. Travel history may provide a clue to the most probable species. This case demonstrates a case of C gattii meningitis with a multiplicity of complications. These include advanced HIV disease secondary to nonadherence, immune reconstitution inflammatory syndrome, and superior sagittal sinus thrombosis. The patient represented diagnostic and therapeutic dilemmas over time. Headache was the primary symptom in cryptococcal meningitis, immune reconstitution inflammatory syndrome, and superior sagittal sinus thrombosis. All are discussed in detail as potential etiologies for the primary disease. Isavuconazonium is a relatively new broad-spectrum antifungal azole that was used as salvage therapy.


Sujet(s)
Antifongiques/usage thérapeutique , Cryptococcus gattii/isolement et purification , Infections à VIH/complications , Méningite cryptococcique/microbiologie , Liquide cérébrospinal/microbiologie , Humains , Syndrome inflammatoire de restauration immunitaire/complications , Mâle , Méningite cryptococcique/traitement médicamenteux , Adulte d'âge moyen , Nitriles/usage thérapeutique , Pyridines/usage thérapeutique , Sinus sagittal supérieur/anatomopathologie , Thrombose/complications , Triazoles/usage thérapeutique
11.
Nat Commun ; 11(1): 3463, 2020 Jul 10.
Article de Anglais | MEDLINE | ID: mdl-32651374

RÉSUMÉ

Understanding the atomistic origin of defects in two-dimensional transition metal dichalcogenides, their impact on the electronic properties, and how to control them is critical for future electronics and optoelectronics. Here, we demonstrate the integration of thermochemical scanning probe lithography (tc-SPL) with a flow-through reactive gas cell to achieve nanoscale control of defects in monolayer MoS2. The tc-SPL produced defects can present either p- or n-type doping on demand, depending on the used gasses, allowing the realization of field effect transistors, and p-n junctions with precise sub-µm spatial control, and a rectification ratio of over 104. Doping and defects formation are elucidated by means of X-Ray photoelectron spectroscopy, scanning transmission electron microscopy, and density functional theory. We find that p-type doping in HCl/H2O atmosphere is related to the rearrangement of sulfur atoms, and the formation of protruding covalent S-S bonds on the surface. Alternatively, local heating MoS2 in N2 produces n-character.

12.
J Investig Med High Impact Case Rep ; 8: 2324709620938947, 2020.
Article de Anglais | MEDLINE | ID: mdl-32618206

RÉSUMÉ

We describe the case of a 41-year-old Hispanic male, inconsistently adherent to visits and workup due to socioeconomic challenges, who presented with a right testicular mass. Because of the overriding concern that this was malignant, he underwent a right orchiectomy. Pathology revealed granulomatous disease with no evidence of malignancy. No specific diagnosis was made histologically or microbiologically on primary laboratory investigation. Six months later, he developed swelling of the left testicle and was subsequently seen in consultation at the Infectious Disease Clinic Kern Medical. An extensive evaluation for granulomatous inflammation was undertaken without a positive result. A clinical diagnosis of tuberculous epididymal orchitis was made and the patient was initiated on standard 4-drug antituberculous therapy. There was a gradual resolution of pain and swelling. After 6 months of therapy, there was no evidence of residual disease. The patient remains asymptomatic after 8 months of post-therapy follow-up.


Sujet(s)
Orchite/étiologie , Tumeurs du testicule/complications , Tumeurs du testicule/anatomopathologie , Tuberculose/complications , Adulte , Antituberculeux/usage thérapeutique , Diagnostic différentiel , Humains , Mâle , Orchidectomie , Orchite/anatomopathologie , Tuberculose/traitement médicamenteux
13.
Chemistry ; 26(38): 8372-8376, 2020 Jul 08.
Article de Anglais | MEDLINE | ID: mdl-32428282

RÉSUMÉ

Transient self-assembly of dipeptide nanofibers with lifetimes that are predictably variable through dipeptide sequence design are presented. This was achieved using 1,8-naphthalimide (NI) amino acid methyl-esters (Phe, Tyr, Leu) that are biocatalytically coupled to amino acid-amides (Phe, Tyr, Leu, Val, Ala, Ser) to form self-assembling NI-dipeptides. However, competing hydrolysis of the dipeptides results in disassembly. It was demonstrated that the kinetic parameters like lifetimes of these nanofibers can be predictably regulated by the thermodynamic parameter, namely the self-assembly propensity of the constituent dipeptide sequence. These lifetimes could vary from minutes, to hours, to permanent gels that do not degrade. Moreover, the in-built NI fluorophore was utilized to image the transient nanostructures in solution with stimulated emission depletion (STED) based super-resolution fluorescence microscopy.


Sujet(s)
Dipeptides/composition chimique , Nanofibres/composition chimique , Nanostructures/composition chimique , Dérivés de la benzo[de]isoquinoléine-1,3-dione/composition chimique , Acides aminés , Gels , Hydrolyse , Cinétique
14.
Nat Chem ; 10(7): 696-703, 2018 07.
Article de Anglais | MEDLINE | ID: mdl-29713031

RÉSUMÉ

Aqueous compatible supramolecular materials hold promise for applications in environmental remediation, energy harvesting and biomedicine. One remaining challenge is to actively select a target structure from a multitude of possible options, in response to chemical signals, while maintaining constant, physiological conditions. Here, we demonstrate the use of amino acids to actively decorate a self-assembling core molecule in situ, thereby controlling its amphiphilicity and consequent mode of assembly. The core molecule is the organic semiconductor naphthalene diimide, functionalized with D- and L- tyrosine methyl esters as competing reactive sites. In the presence of α-chymotrypsin and a selected encoding amino acid, kinetic competition between ester hydrolysis and amidation results in covalent or non-covalent amino acid incorporation, and variable supramolecular self-assembly pathways. Taking advantage of the semiconducting nature of the naphthalene diimide core, electronic wires could be formed and subsequently degraded, giving rise to temporally regulated electro-conductivity.


Sujet(s)
Acides aminés/composition chimique , Biocatalyse , Nanostructures , Chromatographie en phase liquide à haute performance , Chymotrypsine/composition chimique , Hydrolyse , Cinétique , Microscopie électronique à transmission , Stéréoisomérie , Tyrosine/composition chimique
15.
Angew Chem Int Ed Engl ; 56(46): 14511-14515, 2017 11 13.
Article de Anglais | MEDLINE | ID: mdl-28941038

RÉSUMÉ

The reversible regulation of catalytic activity is a feature found in natural enzymes which is not commonly observed in artificial catalytic systems. Here, we fabricate an artificial hydrolase with pH-switchable activity, achieved by introducing a catalytic histidine residue at the terminus of a pH-responsive peptide. The peptide exhibits a conformational transition from random coil to ß-sheet by changing the pH from acidic to alkaline. The ß-sheet self-assembles to form long fibrils with the hydrophobic edge and histidine residues extending in an ordered array as the catalytic microenvironment, which shows significant esterase activity. Catalytic activity can be reversible switched by pH-induced assembly/disassembly of the fibrils into random coils. At higher concentrations, the peptide forms a hydrogel which is also catalytically active and maintains its reversible (de-)activation.


Sujet(s)
Domaine catalytique , Hydrolases/métabolisme , Peptides/métabolisme , Sites de fixation , Dichroïsme circulaire , Histidine/métabolisme , Hydrogels , Concentration en ions d'hydrogène , Hydrolases/composition chimique , Interactions hydrophobes et hydrophiles , Peptides/composition chimique , Conformation des protéines , Spectrométrie de masse ESI , Spectrométrie de masse MALDI
16.
Carbon N Y ; 111: 380-384, 2017 Jan.
Article de Anglais | MEDLINE | ID: mdl-28690336

RÉSUMÉ

Structural properties of sixteen (16) commercial samples of graphene-based materials (GBM) labelled as graphene, graphene oxide or reduced graphene oxide are investigated at room temperature using X-ray diffraction (XRD) and Raman spectroscopy. Based on the observed correlation between the results obtained with these two techniques, these samples are classified into three groups: Group A of seven samples consisting of graphitic nanosheets with evaluated thickness ≃20 nm and exhibiting both the 2H and 3R phases in XRD; Group B of six samples exhibiting XRD spectra characteristic of either graphene oxides (GO) or carbons with some order; and Group C of three samples with XRD spectra characteristic of disordered carbons. The relative intensities and widths of D, G, D', 2D and (D + D') bands in the Raman spectra are equally distinguishable between the samples in groups A, B and C. The width of the D-band is the smallest for Group A samples, intermediate for group B and the largest for group C samples. The intensity ratio I(D)/I(G) of the D and G bands in the Raman spectra of the samples is used to quantify the Raman-active defects whose concentration increases in going from samples in Group A to those in Group C.

17.
Nat Nanotechnol ; 11(11): 960-967, 2016 11.
Article de Anglais | MEDLINE | ID: mdl-27694850

RÉSUMÉ

Sequence-specific polymers, such as oligonucleotides and peptides, can be used as building blocks for functional supramolecular nanomaterials. The design and selection of suitable self-assembling sequences is, however, challenging because of the vast combinatorial space available. Here we report a methodology that allows the peptide sequence space to be searched for self-assembling structures. In this approach, unprotected homo- and heterodipeptides (including aromatic, aliphatic, polar and charged amino acids) are subjected to continuous enzymatic condensation, hydrolysis and sequence exchange to create a dynamic combinatorial peptide library. The free-energy change associated with the assembly process itself gives rise to selective amplification of self-assembling candidates. By changing the environmental conditions during the selection process, different sequences and consequent nanoscale morphologies are selected.


Sujet(s)
Nanostructures/composition chimique , Banque de peptides , Acides aminés/composition chimique , Chromatographie en phase liquide à haute performance , Dichroïsme circulaire , Dipeptides/composition chimique , Spectrométrie de masse , Spectroscopie infrarouge à transformée de Fourier
18.
Am J Physiol Cell Physiol ; 295(2): C440-50, 2008 Aug.
Article de Anglais | MEDLINE | ID: mdl-18524938

RÉSUMÉ

Brain edema is an important factor leading to morbidity and mortality associated with primary brain tumors. Dexamethasone, a synthetic glucocorticoid, is routinely prescribed with antineoplastic agents to alleviate pain associated with chemotherapy and reduce intracranial pressure. We investigated whether dexamethasone treatment increased the expression and activity of multidrug resistance (MDR) transporters at the blood-brain barrier. Treatment of primary rat brain microvascular endothelial cells with submicromolar concentrations of dexamethasone induced significantly higher levels of drug efflux transporters such as breast cancer resistance protein (abcg2), P-glycoprotein (P-gp; abcb1a/abcb1b), and MDR protein 2 (Mrp2; abcc2) as indicted by protein and mRNA levels as well as by functional activity. The effect of dexamethasone on transporter function was significant within 6 h of treatment, was dose dependent, and was reversible. Dexamethasone-induced upregulation of Bcrp and P-gp expression and function was partially abrogated by the glucocorticoid receptor (GR) antagonist RU486. In contrast, RU486 had no effect on the dexamethasone-induced upregulation of Mrp2, suggesting a GR-independent regulation of Mrp2, and a GR-dependent regulation of P-gp and Bcrp. In addition to the dexamethasone-induced upregulation of MDR transporters, we measured a dose-dependent and reversible increase in the expression of the nuclear transcription factor pregnane xenobiotic receptor (PXR). Administering dexamethasone to rats caused increased expression of PXR in brain microvessels within 24 h. These results suggest that adjuvant therapy with corticosteroids such as dexamethasone in the treatment of brain tumors may increase the expression of MDR transporters at the blood-brain barrier through pathways involving GR and PXR.


Sujet(s)
Sous-famille B de transporteurs à cassette liant l'ATP/métabolisme , Barrière hémato-encéphalique/métabolisme , Dexaméthasone/pharmacologie , Protéines associées à la multirésistance aux médicaments/métabolisme , Sous-famille B de transporteurs à cassette liant l'ATP/génétique , Glycoprotéine P/génétique , Glycoprotéine P/métabolisme , Membre-2 de la sous-famille G des transporteurs à cassette liant l'ATP , Transporteurs ABC/antagonistes et inhibiteurs , Transporteurs ABC/génétique , Transporteurs ABC/métabolisme , Animaux , Barrière hémato-encéphalique/cytologie , Barrière hémato-encéphalique/effets des médicaments et des substances chimiques , Technique de Western , Encéphale/effets des médicaments et des substances chimiques , Encéphale/métabolisme , Cellules cultivées , Cellules endothéliales/effets des médicaments et des substances chimiques , Cellules endothéliales/métabolisme , Expression des gènes/effets des médicaments et des substances chimiques , Glucocorticoïdes/pharmacologie , Indènes/pharmacologie , Mâle , Mifépristone/pharmacologie , Protéines associées à la multirésistance aux médicaments/génétique , Récepteur du prégnane X , Prégnénolone carbonitrile/pharmacologie , Rats , Rat Sprague-Dawley , Récepteurs aux glucocorticoïdes/antagonistes et inhibiteurs , Récepteurs aux glucocorticoïdes/métabolisme , Récepteurs aux stéroïdes/génétique , Récepteurs aux stéroïdes/métabolisme , RT-PCR , Régulation positive/effets des médicaments et des substances chimiques
19.
J Biol Chem ; 282(42): 30341-5, 2007 Oct 19.
Article de Anglais | MEDLINE | ID: mdl-17537734

RÉSUMÉ

Janus kinase 3 (Jak3) is a non-receptor tyrosine kinase known to be expressed in hematopoietic cells. Studies of whole organ homogenates show that Jak3 is also expressed in the intestines of both human and mice. However, neither its expression nor its function has been defined in intestinal epithelial enterocytes. The present studies demonstrate that functional Jak3 is expressed in human intestinal enterocytes HT-29 Cl-19A and Caco-2 and plays an essential role in the intestinal epithelial wound repair process in response to interleukin 2 (IL-2). Exogenous IL-2 enhanced the wound repair of intestinal enterocytes in a dose-dependent manner. Activation by IL-2 led to rapid tyrosine phosphorylation and redistribution of Jak3. IL-2-stimulated redistribution of Jak3 was inhibited by the Jak3-specific inhibitor WHI-P131. IL-2 also induced Jak3-dependent redistribution of the actin cytoskeleton in migrating cells. In these cells Jak3 interacted with the intestinal and renal epithelial cell-specific cytoskeletal protein villin in an IL-2-dependent manner. Inhibition of Jak3 activation resulted in loss of tyrosine phosphorylation of villin and a significant decrease in wound repair of the intestinal epithelial cells. Previously, we had shown that tyrosine phosphorylation of villin is important for cytoskeletal remodeling and cell migration. The present study demonstrates a novel pathway in intestinal enterocytes in which IL-2 enhances intestinal wound repair through mechanisms involving Jak3 and its interactions with villin.


Sujet(s)
Entérocytes/enzymologie , Interleukine-2/pharmacologie , Muqueuse intestinale/traumatismes , Janus kinase 3/métabolisme , Protéines des microfilaments/métabolisme , Cicatrisation de plaie/effets des médicaments et des substances chimiques , Actines/métabolisme , Animaux , Cellules Caco-2 , Mouvement cellulaire/effets des médicaments et des substances chimiques , Cytosquelette/métabolisme , Relation dose-effet des médicaments , Entérocytes/anatomopathologie , Activation enzymatique/effets des médicaments et des substances chimiques , Cellules souches hématopoïétiques/enzymologie , Humains , Muqueuse intestinale/enzymologie , Muqueuse intestinale/anatomopathologie , Souris , Phosphorylation/effets des médicaments et des substances chimiques , Maturation post-traductionnelle des protéines/effets des médicaments et des substances chimiques , Transport des protéines/effets des médicaments et des substances chimiques , Quinazolines/pharmacologie , Tyrosine/métabolisme
20.
Chemotherapy ; 53(3): 210-7, 2007.
Article de Anglais | MEDLINE | ID: mdl-17356269

RÉSUMÉ

BACKGROUND: We previously showed that the anti-inflammatory drug, sulfasalazine (salicylazosulfapyridine, SASP), can arrest proliferation of MCF-7 and MDA-MB-231 mammary cancer cells by inhibiting uptake of cystine via the x(c-) cystine/glutamate antiporter. Here we examined SASP with regard to reduction of cellular glutathione (GSH) levels and drug efficacy-enhancing ability. METHODS: GSH levels were measured spectrophotometrically. Cellular drug retention was determined with 3H-labeled methotrexate, and drug efficacy with a colony formation assay. RESULTS: Incubation of the mammary cancer cells with SASP (0.3-0.5 mM) led to reduction of their GSH content in a time- and concentration-dependent manner. Similar to MK-571, a multidrug resistance-associated protein inhibitor, SASP increased intracellular accumulation of methotrexate. Preincubation of cells with SASP (0.3 mM) significantly enhanced the potency of the anticancer agent doxorubicin (2.5 nM). CONCLUSIONS: SASP-induced reduction of cellular GSH levels can lead to growth arrest of mammary cancer cells and enhancement of anticancer drug efficacy.


Sujet(s)
Anti-inflammatoires non stéroïdiens/pharmacologie , Antibiotiques antinéoplasiques/pharmacologie , Tumeurs du sein/traitement médicamenteux , Doxorubicine/pharmacologie , Sulfasalazine/pharmacologie , Sous-famille B de transporteurs à cassette liant l'ATP/antagonistes et inhibiteurs , Glycoprotéine P/antagonistes et inhibiteurs , Antimétabolites antinéoplasiques/métabolisme , Carcinomes/traitement médicamenteux , Lignée cellulaire tumorale , Prolifération cellulaire/effets des médicaments et des substances chimiques , Résistance aux médicaments antinéoplasiques , Synergie des médicaments , Glutathion/analyse , Glutathion/métabolisme , Humains , Méthotrexate/métabolisme , Oxydoréduction , Propionates/pharmacologie , Quinoléines/pharmacologie , Test clonogénique de cellules souches tumorales ,
SÉLECTION CITATIONS
DÉTAIL DE RECHERCHE
...