Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 117
Filtrar
Más filtros

Bases de datos
País/Región como asunto
Tipo del documento
Intervalo de año de publicación
1.
Photochem Photobiol Sci ; 16(6): 883-889, 2017 Jun 14.
Artículo en Inglés | MEDLINE | ID: mdl-28379252

RESUMEN

Several studies suggest that light in the UVA range (320-400 nm) activates signaling pathways that are anti-inflammatory and antioxidative. These effects have been attributed to Nrf2-mediated upregulation of "phase 2" genes such as heme oxygenase-1 (HO-1) that neutralize oxidative stress and metabolize electrophiles. Proteomics analysis previously had shown that small doses of blue light (400-500 nm) increased levels of peroxiredoxin phase 2 proteins in THP-1 monocytes, which led to our hypothesis that blue light activates Nrf2 signaling and thus may serve as an anti-inflammatory agent. THP-1 monocytes were treated with doses of blue light with and without lipopolysaccharide (LPS) inflammatory challenge. Cell lysates were tested for Nrf2 activation and HO-1 production. Treated cells were assessed for viability/mitochondrial activity via trypan blue exclusion and MTT assay, and secretion of two major pro-inflammatory cytokines, interleukin 8 (IL8) and tumor necrosis factor alpha (TNFα) was measured using ELISA. Blue light activated the phase 2 response in cultured THP-1 cells and was protective against LPS-induced cytotoxicity. Light pre-treatment also significantly reduced cytokine secretion in response to 0.1 µg ml-1 LPS, but had no anti-inflammatory effect at high LPS levels. This study is the first to report these effects using a light source that is approved for routine use on dental patients. Cellular responses to these light energies are worth further study and may provide therapeutic interventions for inflammation.


Asunto(s)
Inflamación/metabolismo , Luz , Factor 2 Relacionado con NF-E2/metabolismo , Transducción de Señal/efectos de la radiación , Células Cultivadas , Humanos , Células THP-1
2.
J Cell Biol ; 100(2): 638-41, 1985 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-2981890

RESUMEN

Production of GP140, a major component of the extracellular matrix of cultured fibroblasts, is markedly decreased in SV40 transformed cells as compared with normal cells (Carter, W. G., 1982, J. Biol. Chem., 257:13805-13815). To determine at what step the biosynthesis is inhibited, we compared the levels of functional mRNA for GP140 in normal and transformed fibroblasts. Translation of total RNA from W138 cells in a reticulocyte lysate, followed by immunoprecipitation with affinity-purified antibodies to GP140, yielded a single polypeptide with an Mr of 125,000. This polypeptide was identified as GP140 based on its immunoreactivity, collagenase sensitivity, and comigration on polyacrylamide gels with GP140 synthesized by cells in the presence of tunicamycin and 2,2'-bipyridyl. No cell-free synthesis of GP140 was observed with total RNA from SV40 transformed W138 cells, indicating that these cells contain very low levels of GP140-specific mRNA. The biosynthesis of GP140 might therefore be blocked at the transcriptional level.


Asunto(s)
Transformación Celular Viral , Colágeno/genética , Matriz Extracelular/metabolismo , Células Cultivadas , Regulación de la Expresión Génica , Humanos , Pulmón , Peso Molecular , Proteínas Musculares/metabolismo , ARN Mensajero/genética , Virus 40 de los Simios , Vinculina
3.
Alcohol ; 80: 109-117, 2019 11.
Artículo en Inglés | MEDLINE | ID: mdl-30419299

RESUMEN

The relatively low long-term survival rate of lung transplant recipients as compared to other organ recipients serves as an impetus to identify potential lung dysfunction as early as possible. There is an association between donor heavy alcohol use and acute lung injury in the lung allograft after transplant, known as primary graft dysfunction. Excessive alcohol use (EAU) can induce pulmonary immune dysregulation in response to an infection. Antimicrobial peptides (AMPs) are an important component of the innate immune response to pulmonary infections, but the impact of EAU on AMPs in the allograft lung has not been evaluated. Our hypothesis is that specific lung AMPs, LL-37, α-defensin-1,2,3, and ß-defensin-2, are dysregulated in the lungs from organ donors who had EAU. In this prospective observational investigation, we measured AMPs via ELISA and inflammatory cytokines via multiplex bead array, in bronchoalveolar lavage (BAL) fluid of lung allograft donors, comparing results based on their alcohol consumption. LL-37 levels in lung donors with EAU were found to be increased compared to nondrinker (ND) donors [median 7.7 ng/mL (IQR 4.1-37.0) vs. 2.3 ng/mL (IQR 1.1-7.9), p = 0.004], whereas α-defensins-1,2,3 were decreased only in the presence of an infection in donors with EAU compared to ND donors [median 2.2 ng/mL (IQR 1.6-2.4) vs. 3.2 ng/mL (IQR 2.3-3.8), p = 0.049]. There was no difference in ß-defensin-2 levels. Gene expression levels of these AMPs were not different. Elevated levels of CXCL8 were noted in bronchial washings of donors with EAU compared to ND donors, [median 4372 pg/mL (IQR 3352-13180) vs. 867.3 pg/mL (IQR 163.6-3675), p = 0.04], suggesting a potentially heightened inflammatory response. At 1 month post-transplant, LL-37 and CXCL8 levels are decreased compared to levels at time of transplant. In lung donors with EAU, LL-37 and α-defensins-1,2,3 dysregulated levels in the presence of an infection may be a harbinger of dysfunction of the lungs through the transplant process.


Asunto(s)
Alcoholismo/complicaciones , Péptidos Catiónicos Antimicrobianos/análisis , Pulmón/efectos de los fármacos , Adulto , Líquido del Lavado Bronquioalveolar/química , Citocinas/metabolismo , Ensayo de Inmunoadsorción Enzimática , Femenino , Expresión Génica/efectos de los fármacos , Humanos , Pulmón/química , Pulmón/metabolismo , Trasplante de Pulmón , Masculino , Persona de Mediana Edad , Donantes de Tejidos , Adulto Joven , Catelicidinas
4.
Int Endod J ; 41(12): 1072-8, 2008 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-19133096

RESUMEN

AIM: To test the hypothesis that extending the time of a traditional ex vivo cytotoxicity test helps to identify trends in the behaviour of root core materials and sealers, which could ultimately aid in predicting their clinical safety and performance. METHODOLOGY: Endodontic sealers and core specimens were initially tested in direct contact with L929 fibroblasts for 72 h. Cell response was estimated by measuring cellular succinate dehydrogenase activity relative to Teflon controls. Cytotoxicity (% of more active cells) was reassessed after 1, 3, 4 and 6 weeks, with the specimens stored in a physiologically balanced salt-solution between tests. RESULTS: Distinct trends in cytotoxicity among both core materials and sealers were observed over the 6-week test. Four of the six sealers and two of the three core materials showed cell viabilities of <30% of Teflon after 6 weeks (>70% cytotoxicity). CONCLUSIONS: The current results suggest that some endodontic materials have an elevated biological risk for extended intervals.


Asunto(s)
Materiales de Obturación del Conducto Radicular/toxicidad , Animales , Línea Celular , Supervivencia Celular/efectos de los fármacos , Colorantes , Resinas Compuestas/toxicidad , Dimetilpolisiloxanos/toxicidad , Combinación de Medicamentos , Resinas Epoxi/toxicidad , Fibroblastos/efectos de los fármacos , Predicción , Gutapercha/toxicidad , Ensayo de Materiales , Ratones , Mitocondrias/enzimología , Poliésteres/toxicidad , Cementos de Resina/toxicidad , Seguridad , Succinato Deshidrogenasa/efectos de los fármacos , Sales de Tetrazolio , Tiazoles , Factores de Tiempo , Cemento de Óxido de Zinc-Eugenol/toxicidad
5.
Mol Cell Biol ; 6(4): 1253-60, 1986 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-2946934

RESUMEN

When a strong promoter derived from the mouse metallothionein gene was substituted for the homologous adenovirus type 2 E1a promoter, leading to enhanced levels of E1a RNAs and proteins in cells transfected with the chimeric gene, the E1a gene alone was able to induce in established cell lines alterations in cellular morphology and growth properties similar to those produced by the combined action of E1a and E1b genes. The qualitative effects of E1a gene expression upon cellular properties thus depend on the level of expression of the E1a gene. Furthermore, E1a may be the primary transforming gene of adenoviruses, since it produced many of the characteristics of transformed cells that had previously been attributed to E1b.


Asunto(s)
Adenovirus Humanos/genética , Transformación Celular Neoplásica , Genes Virales , Genes , Proteínas Oncogénicas Virales/genética , Transcripción Genética , Proteínas Precoces de Adenovirus , Animales , Células Cultivadas , Metalotioneína/genética , Ratones , Ratones Endogámicos , Regiones Promotoras Genéticas , Transfección
6.
J Biomed Mater Res A ; 83(1): 123-9, 2007 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-17385233

RESUMEN

Resin composites are widely used in dentistry, and are polymerized in situ using a blue-light activated, free-radical polymerization mechanism. Blue light (400-500nm) is used to activate camphoroquinone (CQ), which decomposes to form free radicals that are stabilized by dimethyl-p-toludine (DMPT). CQ and DMPT are applied near tooth pulpal tissues and are irradiated during restorative procedures, suggesting that pulpal cells are exposed to free radicals. Because glutathione is a major component of the cellular redox management system, we tested the hypothesis that blue light irradiation would shift cellular glutathione redox balance of cells exposed to CQ and DMPT. We also measured NFkappaB activation, a redox-sensitive transcription factor that regulates inflammatory responses and glutathione synthetic enzyme levels. THP1 human monocytes were exposed to sublethal levels of CQ (0.4 mM) or DMPT (1.0 mM), with or without blue light exposure (25 J/cm(2)) from a quartz-tungsten-halogen source. The ratio of reduced to oxidized glutathione was measured using as assay based on 5,5'-dithio-bis(2-nitrobenszoic acid). NFkappaB transactivation was measured by transfection of an NFkappaB-containing plasmid linked to a luciferase reporter. Our results showed that blue light, CQ, or DMPT alone had no significant effect on cellular glutathione redox balance, but that the combination of these agents induced a marked oxidative bias, and reduced total glutathione levels up to 50%. On the other hand, light, CQ, and DMPT alone or in combination suppressed NFkappaB transactivation by >70%. Our results suggest that CQ and DMPT pose risks to pulpal tissues with or without blue light irradiation, and that multiple, interacting mechanisms shape the response to these agents.


Asunto(s)
Radicales Libres/metabolismo , Luz , Monocitos/efectos de los fármacos , Monocitos/efectos de la radiación , Terpenos/farmacología , Toluidinas/farmacología , Línea Celular , Glutatión/metabolismo , Humanos , Monocitos/enzimología , Monocitos/metabolismo , FN-kappa B/genética , Oxidación-Reducción/efectos de los fármacos , Oxidación-Reducción/efectos de la radiación , Succinato Deshidrogenasa/metabolismo , Activación Transcripcional/efectos de los fármacos , Activación Transcripcional/genética
7.
J Biomed Mater Res B Appl Biomater ; 83(1): 58-63, 2007 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-17285613

RESUMEN

Biomedical implants significantly improve the quality of life in an ever-increasing number of patients. However, inflammation of tissues around implants remains a long-term, post-placement sequelae that may contribute to implant failure. Infection-mediated failure is partly a consequence of inappropriate host response and chronic inflammation, and is mediated primarily by the secretory products of monocytes and macrophages. Although the secretion of inflammatory mediators from activated monocytes is well characterized, the resolution of mediator levels post-activation is relatively unstudied. The current study defines the time course of cytokine secretion by activated human monocytes after the activator has been removed. THP1 human monocytes were activated by LPS, and cytokine secretion was monitored over time after LPS removal using enzyme-linked immunosorbent assays (TNFalpha or IL8) or a cytokine array. The release of cytokines was compared with conditions without LPS removal. As expected, secretion of nearly all cytokines was reduced when LPS was removed, but the amount of the reduction was highly cytokine-dependent. Furthermore, levels of cytokines were stable in medium alone but not in cell-culture, suggesting an active process to either degrade or internalize secreted cytokines. Our results are consistent with clinical experience that inflammation resolves rapidly after treatment to remove bacteria or inflamed tissue. However, the differential cytokine regulation indicates a sophisticated coordination of cytokine levels probably associated with management of the wound healing response after removal of the bacterial insult. This wound healing response is one critical component of the long-term success of biomedical implants.


Asunto(s)
Citocinas/metabolismo , Monocitos/inmunología , Monocitos/metabolismo , Prótesis e Implantes/efectos adversos , Células Cultivadas , Citocinas/inmunología , Humanos , Inflamación/inmunología , Interleucina-8/inmunología , Lipopolisacáridos/inmunología , Monocitos/citología , Factor de Necrosis Tumoral alfa/metabolismo
8.
J Biomed Mater Res B Appl Biomater ; 83(2): 505-11, 2007 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-17471514

RESUMEN

UNLABELLED: Monosodium titanate (MST) particles effectively bind specific metals and are therefore promising compounds for delivery or sequestration of metals in biological contexts. Yet, the biological properties of MST are largely unexplored. Our previous study showed that the cytotoxicity of these compounds was mild, but the nature of the dose response curves suggested that residual titanates in culture may have interfered with the assay. In the current study, we assessed the importance of these artifacts, and extended our previous results using fibroblasts for biological evaluation. We also assessed the biological response to a new type of titanate (referred to as amorphous peroxo-titanate or APT) that shows more promising metal binding properties than MST. METHODS: The degree of titanate-induced interference in the MTT (mitochondrial activity assay) was estimated by means of cell-free assays with and without a final centrifugation step to remove residual titanate particulate. Cytotoxic responses to titanates were assessed by measuring succinate dehydrogenase activity (by MTT) in THP1 monocytes or L929 fibroblasts after 24-72 h exposures. Monocytic activation by APT was assessed by TNFalpha secretion (ELISA) from monocytes with or without lipopolysaccharide (LPS) activation. RESULTS: We confirmed that residual titanate particulates may alter the SDH activity assay, but that this effect is eliminated by adding a final centrifugation step to the standard MTT procedure. Addition of MST or APT at concentrations up to 100 mg/L altered succinate dehydrogenase activity by < 25% in both monocytes and fibroblasts. Fibroblasts displayed time-dependent adaptation to the MST. APT did not trigger TNFalpha secretion or modulate LPS-induced TNFalpha secretion from monocytes. CONCLUSIONS: Although further in vitro and in vivo assessment is needed, MST and APT exhibit biological properties that are promising for their use as agents to sequester or deliver metals in biological systems.


Asunto(s)
Materiales Biocompatibles/toxicidad , Fibroblastos/efectos de los fármacos , Monocitos/efectos de los fármacos , Óxidos/toxicidad , Titanio/toxicidad , Animales , Materiales Biocompatibles/química , Línea Celular , Fibroblastos/enzimología , Humanos , Ensayo de Materiales , Ratones , Mitocondrias/efectos de los fármacos , Monocitos/inmunología , Óxidos/química , Succinato Deshidrogenasa/análisis , Titanio/química , Factor de Necrosis Tumoral alfa/análisis
9.
J Biomed Mater Res B Appl Biomater ; 81(2): 397-402, 2007 May.
Artículo en Inglés | MEDLINE | ID: mdl-17022055

RESUMEN

UNLABELLED: The biological response to dental restorative polymer composites is mediated by the release of unpolymerized residual monomers. Several new composite formulations claim to reduce unpolymerized residual mass. The current study assessed the cytotoxic responses to several of these new formations and compared them with more traditional formulations. Our hypothesis predicted that if these new polymerization chemistries reduce unpolymerized residual mass, the cytotoxicity of these materials also should be reduced relative to traditional formulations. METHODS: Materials (HerculiteXRV, Premise, Filtek Supreme, CeramxDuo, Hermes, and Quixfil) were tested in vitro in direct contact with Balb mouse fibroblasts, initially, then after aging in artificial saliva for 0, 1, 3, 5, or 8 weeks. The toxicity was determined by using the MTT assay to the estimate SDH activity. Knoop hardness of the materials also was measured at 0 and 8 weeks to determine whether surface breakdown of the materials in artificial saliva contributed to cytotoxic responses. RESULTS: Materials with traditional methacrylate chemistries (Herculite, Premise, Filtek Supreme) were severely (>50%) cytotoxic throughout the 8-week interval, but materials with newer chemistries or filling strategies (Hermes, CeramXDuo, and Quixfil) improved over time of aging in artificial saliva. Hermes showed the least cytotoxicity at 8 weeks, and was statistically equivalent to Teflon negative controls. Hardness of the materials was unaffected by exposure to artificial saliva. CONCLUSIONS: Newer polymerization and filling strategies for dental composites show promise for reducing the release of unpolymerized components and cytotoxicity.


Asunto(s)
Resinas Compuestas/química , Resinas Compuestas/toxicidad , Animales , Células 3T3 BALB , Técnicas In Vitro , Ensayo de Materiales , Ratones , Mitocondrias/efectos de los fármacos , Mitocondrias/metabolismo , Cementos de Resina/química , Cementos de Resina/toxicidad , Saliva
10.
J Biomed Mater Res A ; 77(3): 470-7, 2006 Jun 01.
Artículo en Inglés | MEDLINE | ID: mdl-16482554

RESUMEN

Blue light from dental photopolymerization devices has significant biological effects on cells. These effects may alter normal cell function of tissues exposed during placement of oral restorations, but recent data suggest that some light-induced effects may also be therapeutically useful, for example in the treatment of epithelial cancers. Reactive oxygen species (ROS) appear to mediate blue light effects in cells, but the sources of ROS (intra- versus extracellular) and their respective roles in the cellular response to blue light are not known. In the current study, we tested the hypothesis that intra- and extracellular sources of blue light-generated ROS synergize to depress mitochondrial function. Normal human epidermal keratinocytes (NHEK) and oral squamous cell carcinoma (OSC2) cells were exposed to blue light (380-500 nm; 5-60 J/cm(2)) from a dental photopolymerization source (quartz-tungsten-halogen, 550 mW/cm(2)). Light was applied in cell-culture media or balanced salt solutions with or without cells present. Intracellular ROS levels were estimated using the dihydrofluorescein diacetate (DFDA) assay; extracellular ROS levels were estimated using the leucocrystal violet assay. Cell response was estimated using the MTT mitochondrial activity assay. Blue light increased intracellular ROS equally in both NHEK and OSC2. Blue light also increased ROS levels in cell-free MEM or salt solutions, and riboflavin supplements increased ROS formation. Extracellularly applied ROS rapidly (50-400 muM, <1 min) increased intracellular ROS levels, which were higher and longer-lived in NHEK than OSC2. The type of cell-culture medium significantly affected the ability of blue light to suppress cellular mitochondrial activity; the greatest suppression was observed in DMEM-containing or NHEK media. Collectively, the data support our hypothesis that intra- and extracellularly generated ROS synergize to affect cellular mitochondrial suppression of tumor cells in response to blue light. However, the identity of blue light targets that mediate these changes remain unclear. These data support additional investigations into the risks of coincident exposure of tissues to blue light during material polymerization of restorative materials, and possible therapeutic benefits.


Asunto(s)
Queratinocitos/metabolismo , Luz , Especies Reactivas de Oxígeno/metabolismo , Línea Celular Tumoral , Células Cultivadas , Humanos , Succinato Deshidrogenasa
11.
J Biomed Mater Res B Appl Biomater ; 78(2): 296-301, 2006 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-16362965

RESUMEN

Monosodium titanate (MST) is an inorganic sorbent/ion exchanger developed for the removal of radionuclides from nuclear wastes. We investigated the ability of MST to bind Cd(II), Hg(II), Au(III), or the Au-organic compound auranofin to establish the utility of MST for applications in environmental decontamination or medical therapy (drug delivery). Adsorption isotherms for MST were determined at pH 7-7.5 in water or phosphate-buffered saline. The extent of metal binding was determined spectroscopically by measuring the concentrations of the metals in solution before and after contact with the MST. Cytotoxic responses to MST were assessed using THP1 monocytes and succinate dehydrogenase activity. Monocytic activation by MST was assessed by TNFalpha secretion (ELISA) with or without lipopolysaccharide (LPS) activation. MST adsorbed Cd(II), Hg(II), and Au(III) under conditions similar to those in physiological systems. MST exhibited the highest affinity for Cd(II) followed by Hg(II) and Au (III). MST (up to 100 mg/L) exhibited only minor (<25% suppression of succinate dehydrogenase) cytotoxicity and did not trigger TNFalpha secretion nor modulate LPS-induced TNFalpha secretion from monocytes. MST exhibits high affinity for biometals with no significant biological liabilities in these introductory studies. MST deserves further scrutiny as a substance with the capacity to decontaminate biological environments or deliver metals or metal compounds for therapeutic applications.


Asunto(s)
Auranofina/química , Sistemas de Liberación de Medicamentos , Metales Pesados/química , Monocitos , Adsorción , Auranofina/uso terapéutico , Materiales Biocompatibles , Línea Celular , Descontaminación , Humanos , Intercambio Iónico , Lipopolisacáridos/farmacología , Lipopolisacáridos/toxicidad , Ensayo de Materiales , Metales Pesados/uso terapéutico , Monocitos/metabolismo , Monocitos/ultraestructura , Residuos Radiactivos , Succinato Deshidrogenasa/metabolismo , Factor de Necrosis Tumoral alfa/metabolismo
12.
J Pediatr Adolesc Gynecol ; 29(1): 11-7, 2016 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-26165914

RESUMEN

STUDY OBJECTIVE: To determine whether prenatal depressive symptoms are associated with postpartum sexual risk among young, urban women of color. DESIGN: Participants completed surveys during their second trimester of pregnancy and at 1 year postpartum. Depressive symptoms were measured using the Center for Epidemiologic Studies-Depression Scale, excluding somatic items because women were pregnant. Logistic and linear regression models adjusted for known predictors of sexual risk and baseline outcome variables were used to assess whether prenatal depressive symptoms make an independent contribution to sexual risk over time. SETTING: Fourteen community health centers and hospitals in New York City. PARTICIPANTS: The participants included 757 predominantly black and Latina (91%, n = 692) pregnant teens and young women aged 14-21 years. INTERVENTIONS AND MAIN OUTCOME MEASURES: The main outcome measures were number of sex partners, condom use, exposure to high-risk sex partners, diagnosis of a sexually transmitted disease, and repeat pregnancy. RESULTS: High levels of prenatal depressive symptoms were significantly associated with increased number of sex partners (ß = 0.17; standard error, 0.08), decreased condom use (ß = -7.16; standard error, 3.08), and greater likelihood of having had sex with a high-risk partner (odds ratio = 1.84; 95% confidence interval, 1.26-2.70), and repeat pregnancy (odds ratio = 1.72; 95% confidence interval, 1.09-2.72), among participants who were sexually active (all P < .05). Prenatal depressive symptoms were not associated with whether participants engaged in postpartum sexual activity or sexually transmitted disease incidence. CONCLUSION: Screening and treatment for depression should be available routinely to women at risk for antenatal depression.


Asunto(s)
Negro o Afroamericano/psicología , Depresión Posparto/psicología , Depresión/diagnóstico , Hispánicos o Latinos/psicología , Complicaciones del Embarazo/psicología , Conducta Sexual/psicología , Adolescente , Conducta Anticonceptiva/psicología , Conducta Anticonceptiva/estadística & datos numéricos , Depresión/psicología , Femenino , Humanos , Incidencia , Modelos Logísticos , Ciudad de Nueva York/epidemiología , Oportunidad Relativa , Periodo Posparto , Embarazo , Complicaciones del Embarazo/diagnóstico , Segundo Trimestre del Embarazo/psicología , Medición de Riesgo/métodos , Factores de Riesgo , Parejas Sexuales , Enfermedades de Transmisión Sexual/epidemiología , Enfermedades de Transmisión Sexual/etiología , Encuestas y Cuestionarios , Sexo Inseguro/psicología , Sexo Inseguro/estadística & datos numéricos , Adulto Joven
13.
J Biomed Mater Res A ; 74(3): 474-81, 2005 Sep 01.
Artículo en Inglés | MEDLINE | ID: mdl-15983993

RESUMEN

The transcription factor NFkappaB plays a key role in the tissue inflammatory response. Metal ions released into tissues from biomaterials (e.g., Au, Pd, Ni, Hg) are known to alter the binding of NFkappaB proteins to DNA, thereby modulating the effect of NFkappaB on gene activation and, ultimately, the tissue response to biomaterials. Little is known about the effect of these metals on key signaling steps prior to NFkappaB-DNA binding such as transcription factor activation or nuclear translocation, yet these steps are equally important to modulation of the pathway. Oxidative stress is known to alter NFkappaB proteins and is suspected to play a role in metal-induced NFkappaB signaling modulation. Our aim in the current study was to assess the effects of sublethal levels of Ni, Hg, Pd, and Au ions on NFkappaB activation and nuclear translocation in the monocyte, which is acknowledged as an important orchestrator of the biological response to materials and the pathogenesis of chronic disease. Sublethal concentrations of Au(III), Ni(II), Hg(II), and Pd(II) were added to cultures of human THP1 monocytic cells for 72 h. In parallel cultures, lipopolysaccharide (LPS) was added for the last 30 min to activate the monocytic cells. Then cellular cytoplasmic and nuclear proteins were isolated, separated by electrophoresis, and probed for IkappaBalpha degradation (activation) and NFkappaB p65 translocation. Protein levels were digitally quantified and statistically compared. The levels of reactive oxygen species (ROS) in the monocytic cells were measured as a possible mechanism of metal-induced NFkappaB modulation. Only Au(III) activated IkappaBalpha degradation by itself. Au(III) and Pd(II) enhanced LPS-induced IkappaBalpha degradation, but Hg(II) and Ni(II) suppressed it. Au(III), Ni(II), and Pd(II) activated p65 nuclear translocation without LPS, and all but Ni(II) enhanced LPS-induced translocation. Collectively, the results suggest that these metal ions alter activation and translocation of NFkappaB, each in a unique way at unique concentrations. Furthermore, even when these metals had no overt effects on signaling by themselves, all altered activation of signaling by LPS, suggesting that the biological effects of these metals on monocytic function may only be manifest upon activation. None of the metal ions elevated levels of ROS at 72 h, indicating that ROS were probably not direct modulators of the NFkappaB activation or translocation at this late time point.


Asunto(s)
Metales Pesados/farmacología , Monocitos/efectos de los fármacos , Monocitos/fisiología , FN-kappa B/fisiología , Transducción de Señal/efectos de los fármacos , Cationes Bivalentes , Línea Celular Tumoral , Oro/fisiología , Humanos , Proteínas I-kappa B/metabolismo , Immunoblotting , Mercurio/fisiología , Monocitos/metabolismo , Inhibidor NF-kappaB alfa , FN-kappa B/antagonistas & inhibidores , FN-kappa B/metabolismo , Níquel/fisiología , Paladio/fisiología , Fosforilación , Transporte de Proteínas/fisiología , Especies Reactivas de Oxígeno/metabolismo , Transducción de Señal/fisiología
14.
Toxicol In Vitro ; 19(3): 365-71, 2005 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-15713543

RESUMEN

The objective of this study was to quantify the ability of sublethal concentrations of several gold compounds to differentially modulate the monocytic secretion of key cytokines that are important in the etiology of rheumatic diseases. Human THP1 monocytic cells were exposed to the anti-rheumatic drugs auranofin (AF), gold sodium thiomalate (GSTM) or HAuCl4 (Au(III)) for 24-72 h. Succinate dehydrogenase (SDH) activity of the monocytes was used to determine sublethal concentrations. Monocytes were then exposed to sublethal concentrations of gold compounds for 72 h, and the activator lipopolysaccharide (LPS) was added (or not) to cultures for the last 6h. The secretion of IL6, IL8, IL10, and TNFalpha were measured in cell supernatants using ELISA. Cytokine secretion was compared among concentrations and gold compounds. SDH experiments established a sublethal concentration range of 0-75 microM for GSTM and Au(III) and 0-0.5 microM for AF. In cytokine experiments, none of the compounds alone activated secretion of any of the cytokines, but all differentially (50-440%, p<0.05) increased LPS-induced secretion of IL6 and IL8 over TNFalpha and IL10. In conclusion, sublethal concentrations of AF, GSTM, and Au(III) all may differentially modulate activation of monocytic cells, and this differential modulation may be important in the mechanisms of action of these compounds.


Asunto(s)
Antirreumáticos/toxicidad , Auranofina/toxicidad , Cloruros/toxicidad , Citocinas/metabolismo , Compuestos de Oro/toxicidad , Tiomalato Sódico de Oro/toxicidad , Monocitos/efectos de los fármacos , Línea Celular , Relación Dosis-Respuesta a Droga , Humanos , Monocitos/metabolismo , Succinato Deshidrogenasa/metabolismo
15.
J Biomed Mater Res B Appl Biomater ; 73(2): 308-14, 2005 May.
Artículo en Inglés | MEDLINE | ID: mdl-15803495

RESUMEN

The use of hydrophilic dental monomers in dentin bonding agents has vastly improved resin-dentin bond strengths, but incomplete polymerization of these monomers and their leaching into adjacent (pulpal) oral tissues has raised concerns about their biocompatibility. The sublethal effects of these resins are virtually unknown, but their electrophilic nature led to the hypothesis that they may alter cellular oxidative stress pathways. Glutathione balance between reduced (GSH) and oxidized (GSSG) is a major mechanism by which cells maintain redox balance and was therefore the focus of the current investigation. THP-1 human monocytic cells were exposed to hydroxyethyl methacrylate (HEMA), benzoyl peroxide (BPO), camphorquinone (CQ), or triethyelene glycol dimethacrylate (TEGDMA) for 24 h at sublethal doses, then GSH and GSSG levels were measured by means of Ellman's method adapted for cell culture. The results indicate that these dental resin compounds act at least partly via oxidative stress by increasing GSH levels at sublethal concentrations. However, the GSH-GSSG ratio was relatively unaffected. Only BPO altered the GSH-GSSG ratio at 24 h, again at sublethal levels (7.5-15 micromol/L). The results support the hypothesis that resin monomers act, at least in part, via oxidative stress, and that oxidative-stress pathways should be one focus of future investigations of monomer biocompatibility.


Asunto(s)
Recubrimientos Dentinarios/farmacología , Glutatión/metabolismo , Monocitos/fisiología , Estrés Oxidativo/fisiología , Butionina Sulfoximina/farmacología , Línea Celular , Resinas Compuestas/farmacología , Disulfuro de Glutatión/metabolismo , Glutatión Reductasa/metabolismo , Humanos , Metacrilatos/farmacología , Monocitos/efectos de los fármacos , Oxidación-Reducción , Polietilenglicoles/farmacología , Ácidos Polimetacrílicos/farmacología
16.
Arch Intern Med ; 149(5): 1193-4, 1989 May.
Artículo en Inglés | MEDLINE | ID: mdl-2719512

RESUMEN

A 23-year-old woman presented with diarrhea, flaccid quadriparesis, a low serum potassium level, and an elevated creatine kinase level. A stool culture yielded Yersinia enterocolitica, and a muscle biopsy was compatible with a hypokalemic myopathy. The patient's diarrhea responded to sulfamethoxazole and trimethoprim therapy. We suggest that Y enterocolitica be added to the group of intestinal pathogens capable of producing hypokalemia and rhabdomyolysis.


Asunto(s)
Enterocolitis/complicaciones , Hipopotasemia/etiología , Parálisis/etiología , Yersiniosis/complicaciones , Adulto , Femenino , Humanos , Rabdomiólisis/etiología , Yersinia enterocolitica/aislamiento & purificación
17.
Arch Intern Med ; 158(5): 438-48, 1998 Mar 09.
Artículo en Inglés | MEDLINE | ID: mdl-9508221

RESUMEN

The advent of echocardiography has led to the more frequent discovery of impending paradoxical embolism. Paradoxical embolism should be considered whenever there is an arterial embolism from an unidentified source in the presence of a concomitant venous thromboembolic phenomenon. Patients with paradoxical embolism present with neurological abnormalities or features suggesting arterial embolism. Annually, paradoxical embolism may account for up to 47,000 strokes in the United States, and a patent foramen ovale has been reported in up to 35% of the normal population. Events that give rise to pulmonary hypertension may result in a right-to-left shunt through a patent foramen ovale allowing a venous thromboembolism access to the arterial circulation. Herein we report a case of impending paradoxical embolism and review the pertinent literature.


Asunto(s)
Embolia Paradójica/diagnóstico , Defectos del Tabique Interatrial/diagnóstico , Diagnóstico Diferencial , Ecocardiografía Transesofágica , Embolia Paradójica/diagnóstico por imagen , Femenino , Defectos del Tabique Interatrial/diagnóstico por imagen , Humanos , Persona de Mediana Edad
18.
Cell Prolif ; 35(3): 183-92, 2002 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-12027954

RESUMEN

A human oral tumour progression model was established that consists of normal epithelial cells and three cell lines representing stages from dysplastic to metastatic cells. To investigate the impact of exogenous transforming growth factor-beta 1 on this model system, we analysed the responsiveness of those cells to transforming growth factor-beta 1 and explored the potential mechanism underlying the transforming growth factor-beta 1 activity. We found that the growth of all cell types, regardless of their stage of tumour progression, is inhibited by transforming growth factor-beta 1, although to different degrees. Transforming growth factor-beta 1 induced the expression of cyclin-dependent kinase inhibitors p15(INK4B), p21WAF1/(CIP1) and p27(KIP1). In contrast, transforming growth factor-beta 1 was found to stimulate the invasive potential of one cell type that represents the most advanced stage of tumour phenotype, suggesting that the impact of transforming growth factor-beta 1 on functional features of tumour cells other than cellular proliferation may play a significant role in the process of oral tumour progression.


Asunto(s)
Carcinoma/metabolismo , Neoplasias de la Boca/metabolismo , Factor de Crecimiento Transformador beta/farmacología , Transporte Activo de Núcleo Celular , Carcinoma/patología , Proteínas de Ciclo Celular/metabolismo , División Celular/efectos de los fármacos , Línea Celular , Movimiento Celular/efectos de los fármacos , Núcleo Celular/metabolismo , Células Cultivadas , Proteínas de Unión al ADN/metabolismo , Progresión de la Enfermedad , Humanos , Queratinocitos/efectos de los fármacos , Queratinocitos/fisiología , Cinética , Masculino , Persona de Mediana Edad , Neoplasias de la Boca/patología , Proteína smad3 , Transactivadores/metabolismo , Factor de Crecimiento Transformador beta1 , Células Tumorales Cultivadas
19.
Pediatrics ; 88(2): 230-5, 1991 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-1861919

RESUMEN

Ambulatory care centers have emerged as a new health care resource in many communities. Little information is available about the services that these centers offer to pediatric patients. A national survey of 254 ambulatory care centers was undertaken to determine their characteristics, including the number of pediatric patients seen, staffing patterns, and pediatric equipment and supplies available. Most clinics were located in urban areas and were within 5 miles of a hospital. They were staffed primarily by physicians who were board certified in emergency medicine, internal medicine, or family medicine. Not all centers had registered nurses on duty and few used extended-role nurses or physicians's assistants. The centers saw an average of 18 patients younger than 18 years of age per day. Some ambulatory care centers received emergency medical service and private ambulance calls and encountered serious illness such as chest pain, seizures, and anaphylaxis; the majority, however, handled mainly minor injuries and illnesses. Although most had pediatric equipment and supplies, some did not have a complete set of pediatric resuscitation equipment even though they were part of the emergency system offering care to the pediatric population.


Asunto(s)
Instituciones de Atención Ambulatoria , Servicios de Salud del Niño , Servicios Médicos de Urgencia , Recursos en Salud , Niño , Recolección de Datos , Urgencias Médicas , Humanos , Resucitación/instrumentación , Transporte de Pacientes , Estados Unidos
20.
Am J Kidney Dis ; 34(2): 308-14, 1999 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-10430979

RESUMEN

In 1994, we reported a 3.4 +/- 0.8 year follow-up of the eight patients who experienced remission of nephrotic syndrome during the Collaborative Study Group-sponsored, multicenter trial of captopril therapy in patients with type 1 diabetes with nephropathy (Captopril Study). Of the 409 patients randomized to treatment on the Captopril Study, 108 had nephrotic syndrome (24-hour proteinuria >/= 3.5 g of protein) at baseline. Of these 108 patients, 8 experienced remission of nephrotic syndrome (proteinuria

Asunto(s)
Inhibidores de la Enzima Convertidora de Angiotensina/uso terapéutico , Antihipertensivos/uso terapéutico , Captopril/uso terapéutico , Diabetes Mellitus Tipo 1/complicaciones , Nefropatías Diabéticas/tratamiento farmacológico , Síndrome Nefrótico/tratamiento farmacológico , Adulto , Presión Sanguínea/efectos de los fármacos , Creatinina/sangre , Nefropatías Diabéticas/fisiopatología , Progresión de la Enfermedad , Femenino , Estudios de Seguimiento , Humanos , Fallo Renal Crónico/etiología , Masculino , Persona de Mediana Edad , Síndrome Nefrótico/complicaciones , Síndrome Nefrótico/fisiopatología , Estudios Prospectivos , Proteinuria , Ensayos Clínicos Controlados Aleatorios como Asunto , Inducción de Remisión
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA