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1.
N Engl J Med ; 379(19): 1811-1822, 2018 11 08.
Artículo en Inglés | MEDLINE | ID: mdl-30403938

RESUMEN

BACKGROUND: The immunostimulatory monoclonal antibody elotuzumab plus lenalidomide and dexamethasone has been shown to be effective in patients with relapsed or refractory multiple myeloma. The immunomodulatory agent pomalidomide plus dexamethasone has been shown to be effective in patients with multiple myeloma that is refractory to lenalidomide and a proteasome inhibitor. METHODS: Patients with multiple myeloma that was refractory or relapsed and refractory to lenalidomide and a proteasome inhibitor were randomly assigned to receive elotuzumab plus pomalidomide and dexamethasone (elotuzumab group) or pomalidomide and dexamethasone alone (control group). The primary end point was investigator-assessed progression-free survival. RESULTS: A total of 117 patients were randomly assigned to the elotuzumab group (60 patients) or the control group (57 patients). After a minimum follow-up period of 9.1 months, the median progression-free survival was 10.3 months in the elotuzumab group and 4.7 months in the control group. The hazard ratio for disease progression or death in the elotuzumab group as compared with the control group was 0.54 (95% confidence interval [CI], 0.34 to 0.86; P=0.008). The overall response rate was 53% in the elotuzumab group as compared with 26% in the control group (odds ratio, 3.25; 95% CI, 1.49 to 7.11). The most common grade 3 or 4 adverse events were neutropenia (13% in the elotuzumab group vs. 27% in the control group), anemia (10% vs. 20%), and hyperglycemia (8% vs. 7%). A total of 65% of the patients in each group had infections. Infusion reactions occurred in 3 patients (5%) in the elotuzumab group. CONCLUSIONS: Among patients with multiple myeloma in whom treatment with lenalidomide and a proteasome inhibitor had failed, the risk of progression or death was significantly lower among those who received elotuzumab plus pomalidomide and dexamethasone than among those who received pomalidomide plus dexamethasone alone. (Funded by Bristol-Myers Squibb and AbbVie Biotherapeutics; ELOQUENT-3 ClinicalTrials.gov number, NCT02654132 .).


Asunto(s)
Anticuerpos Monoclonales Humanizados/administración & dosificación , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapéutico , Dexametasona/administración & dosificación , Factores Inmunológicos/administración & dosificación , Mieloma Múltiple/tratamiento farmacológico , Talidomida/análogos & derivados , Adulto , Anciano , Anciano de 80 o más Años , Anticuerpos Monoclonales Humanizados/efectos adversos , Protocolos de Quimioterapia Combinada Antineoplásica/efectos adversos , Dexametasona/efectos adversos , Supervivencia sin Enfermedad , Femenino , Humanos , Factores Inmunológicos/efectos adversos , Infecciones/inducido químicamente , Masculino , Persona de Mediana Edad , Mieloma Múltiple/mortalidad , Neutropenia/inducido químicamente , Talidomida/administración & dosificación , Talidomida/efectos adversos
2.
J Cell Physiol ; 230(11): 2634-9, 2015 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-25899830

RESUMEN

Connective Tissue Growth Factor (CCN2/CTGF) and Nephroblastoma Overexpressed (CCN3/NOV) execute key functions within the hematopoietic compartment. Both are abundant in the bone marrow stroma, which is a niche for hematopoiesis and supports marrow function. Roles for 1,25-dihydroxyvitamin D3 (calcitriol) and all-trans retinoic acid in the bone marrow have also been elucidated. Interestingly, some of the annotated roles of these vitamins overlap with established functions of CCN2 and CCN3. Yet, no factor has been identified that unifies these observations. In this study, we report the regulation of the CTGF and NOV genes by Myeloid Zinc Finger-1 (MZF-1), a hematopoietic transcription factor. We show the interaction of MZF-1 with the CTGF and NOV promoters in several cell types. Up-regulation of MZF-1 via calcitriol and vitamin A induces expression of CTGF and NOV, implicating a role for these vitamins in the functions of these two genes. Lastly, knockdown of MZF1 reduces levels of CTGF and NOV. Collectively, our results argue that MZF-1 regulates the CTGF and NOV genes in the hematopoietic compartment, and may be involved in their respective functions in the stroma.


Asunto(s)
Factor de Crecimiento del Tejido Conjuntivo/biosíntesis , Hematopoyesis/genética , Factores de Transcripción de Tipo Kruppel/genética , Proteína Hiperexpresada del Nefroblastoma/biosíntesis , Médula Ósea/metabolismo , Calcitriol/metabolismo , Factor de Crecimiento del Tejido Conjuntivo/genética , Regulación de la Expresión Génica , Humanos , Factores de Transcripción de Tipo Kruppel/metabolismo , Proteína Hiperexpresada del Nefroblastoma/genética , ARN Mensajero/biosíntesis , ARN Mensajero/genética , Tretinoina/metabolismo
3.
Biochem Biophys Res Commun ; 451(1): 137-41, 2014 Aug 15.
Artículo en Inglés | MEDLINE | ID: mdl-25065746

RESUMEN

Recently, new tissue-specific functions for glyceraldehyde 3-phosphate dehydrogenase (GAPDH) have been discovered, aside from its archetypal function in glycolysis. This casts doubt on the legitimacy of using GAPDH as a normalization control for gene expression analysis. We report the binding of the myeloid zinc finger-1 (MZF-1) transcription factor to the human GAPDH promoter. Furthermore, we show that up-regulation of MZF-1 by 1,25-dihydroxyvitamin D3 (calcitriol) induces GAPDH in HS-5 stromal fibroblasts, while knockdown of MZF1 by shRNA leads to a concomitant reduction in GAPDH expression. This argues that MZF-1 regulates GAPDH, indicating a role for GAPDH in calcitriol-mediated signaling.


Asunto(s)
Calcitriol/farmacología , Gliceraldehído-3-Fosfato Deshidrogenasas/genética , Factores de Transcripción de Tipo Kruppel/metabolismo , Secuencia de Bases , Calcitriol/metabolismo , Línea Celular/efectos de los fármacos , Fibroblastos/efectos de los fármacos , Regulación de la Expresión Génica/efectos de los fármacos , Técnicas de Silenciamiento del Gen , Gliceraldehído-3-Fosfato Deshidrogenasas/metabolismo , Humanos , Factores de Transcripción de Tipo Kruppel/genética , Datos de Secuencia Molecular , Regiones Promotoras Genéticas , ARN Interferente Pequeño , Transducción de Señal , Tretinoina/metabolismo , Tretinoina/farmacología
4.
J Surg Oncol ; 109(5): 405-9, 2014 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-24318953

RESUMEN

BACKGROUND: Isolated limb infusion (ILI) is a percutaneous method of delivering regional chemotherapy to patients with recurrent tumors of the extremity. This study determines predictors of response, survival, and limb salvage. METHODS: Single institution data from a prospective clinical trial and subsequent ILI experience were reviewed. Limb tumor burden was assessed in melanoma patients with "high" (≥10 lesions or one lesion >3 cm) or "low" burden (<10 lesions and no lesion >3 cm). Response was assessed at 3 months from ILI. RESULTS: Between 1999 and 2011, 62 patients underwent ILI (58 melanoma, 2 Merkel cell carcinoma (MCC), 2 soft tissue sarcoma (STS)). Low tumor burden patients had more complete responses (CR) (11/23, 48%) than high tumor burden (3/32, 9%, P < 0.001); they had higher 5-year survival (69% vs. 29%, P = .007). Five-year survival rates based on response: 91% CR, 53% partial response (PR), 25% less than PR (P = 0.042, CR vs. PR). 7 patients (11%) underwent amputation due to disease progression; 3 had prior CR or PR. CONCLUSIONS: Low tumor burden is a significant predictor of response in melanoma patients. Response to ILI is a significant predictor of survival. Progression of limb disease requiring amputation is not associated with any factors.


Asunto(s)
Protocolos de Quimioterapia Combinada Antineoplásica/administración & dosificación , Carcinoma de Células de Merkel/tratamiento farmacológico , Quimioterapia del Cáncer por Perfusión Regional , Extremidades , Melanoma/tratamiento farmacológico , Sarcoma/tratamiento farmacológico , Neoplasias Cutáneas/tratamiento farmacológico , Adulto , Anciano , Amputación Quirúrgica/estadística & datos numéricos , Carcinoma de Células de Merkel/mortalidad , Carcinoma de Células de Merkel/patología , Carcinoma de Células de Merkel/cirugía , Dactinomicina/administración & dosificación , Dactinomicina/análogos & derivados , Progresión de la Enfermedad , Esquema de Medicación , Extremidades/patología , Extremidades/cirugía , Femenino , Humanos , Estimación de Kaplan-Meier , Recuperación del Miembro/estadística & datos numéricos , Masculino , Melanoma/mortalidad , Melanoma/patología , Melanoma/cirugía , Melfalán/administración & dosificación , Persona de Mediana Edad , Estadificación de Neoplasias , Estudios Prospectivos , Estudios Retrospectivos , Sarcoma/mortalidad , Sarcoma/patología , Sarcoma/cirugía , Neoplasias Cutáneas/mortalidad , Neoplasias Cutáneas/patología , Neoplasias Cutáneas/cirugía , Resultado del Tratamiento , Carga Tumoral
5.
Ann Surg Oncol ; 20(2): 675-9, 2013 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-22965568

RESUMEN

BACKGROUND: Women may experience distress or changes in their quality of life following treatment for early-stage melanoma. In order to plan future interventions and identify areas of primary concern, we conducted a cross-sectional survey to describe the experiences of women treated for clinically localized melanoma. METHODS: We examined quality of life, levels of distress, appearance perceptions, body image, fear of recurrence, and reproductive concerns in 100 patients (age 21-90 years, M = 54.34 years). Most (61 %) had melanoma of the extremity, with a median depth of 1.1 mm (range, 0-10.5 mm). RESULTS: Significant depressive symptomatology occurred in 10 % of patients, and 12 % reported a clinically established high level of intrusive thoughts related to melanoma. Quality-of-life scores indicated more disruption on psychological, compared with social and physical functioning. Also, 64 % of women rated their appearance as worse post-treatment; 23 % were unsatisfied with the appearance of the surgical site. Recurrence concerns indicated significant worry about health and death. Most patients (>85 %) were not concerned about fertility, but 52 % worried that future children would have an increased risk of cancer. CONCLUSIONS: Some women treated for clinically localized melanoma reported high levels of distress associated with their altered body image and fear of recurrence. Improvements in patient education prior to surgical intervention may reduce the distress associated with the diagnosis and treatment of melanoma.


Asunto(s)
Melanoma/psicología , Calidad de Vida , Neoplasias Cutáneas/psicología , Estrés Psicológico/psicología , Sobrevivientes/psicología , Adaptación Psicológica , Adulto , Anciano , Anciano de 80 o más Años , Estudios Transversales , Femenino , Estudios de Seguimiento , Humanos , Melanoma/complicaciones , Melanoma/patología , Persona de Mediana Edad , Estadificación de Neoplasias , Pronóstico , Neoplasias Cutáneas/complicaciones , Neoplasias Cutáneas/patología , Estrés Psicológico/etiología , Estrés Psicológico/patología , Encuestas y Cuestionarios , Adulto Joven
6.
Biochem Biophys Res Commun ; 418(1): 33-7, 2012 Feb 03.
Artículo en Inglés | MEDLINE | ID: mdl-22226964

RESUMEN

PURPOSE: The retinal pigment epithelium (RPE) is a barrier to Klebsiella pneumoniae infection in endogenous endophthalmitis. Nevertheless, the inflammatory response of RPE cells upon interaction with this pathogen has not been studied. Here we tested the hypothesis that K. pneumoniae induces an inflammatory response in human retinal epithelial cells. METHODS: In this study we set out to investigate the effects of whole K. pneumoniae and of its lipopolysaccharide on RPE cells in vitro using bacterial invasion and cytotoxicity assays, fluorescent microscopy and ELISA. For that, we utilized K. pneumoniae strain ATCC 43816 and the continuous human retinal-pigmented epithelial cell line ARPE-19. RESULTS: Stimulation of ARPE-19 with live K. pneumoniae for 24h induced a 31.5-fold (p=0.0132) increase in IL-6 and 6.5-fold (p=0.0004) increase in MCP-1 levels compared to the non-infected control cells. Purified K. pneumoniae LPS (1µgml(-1)) also induced cytokine levels, MCP-1 (1.7-fold upregulation; p=0.0006) and IL-6 (1.3-fold upregulation, p=0.065). The tested K. pneumoniae strain ATCC 43816 did not have a significant effect on the viability of ARPE-19 cells (11% decrease, p=0.096) and showed a low ability to invade the cells. CONCLUSIONS: Both whole live K. pneumoniae and K. pneumoniae LPS exert a strong pro-inflammatory effect on retinal pigmented epithelial cells, consistent with clinical manifestations of disease. Bacterial pro-inflammatory effects are not likely related to host cell invasion. This is the first investigation of the interactions of a major endogenous endophthalmitis pathogen, K. pneumoniae with human retinal pigmented epithelial cells.


Asunto(s)
Interacciones Huésped-Patógeno/inmunología , Infecciones por Klebsiella/microbiología , Klebsiella pneumoniae , Epitelio Pigmentado de la Retina/microbiología , Retinitis/microbiología , Línea Celular , Quimiocina CCL2/biosíntesis , Humanos , Interleucina-6/biosíntesis , Infecciones por Klebsiella/inmunología , Lipopolisacáridos/inmunología , Epitelio Pigmentado de la Retina/inmunología , Retinitis/inmunología
7.
Cell Immunol ; 280(2): 148-55, 2012 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-23399841

RESUMEN

Intestinal epithelial cells (IEC) play a role in mucosal inflammation by producing pro-inflammatory chemokines that may initiate or amplify local responses. IL-1 is a potent activator of IEC and its receptor localizes to focal adhesions. Since the Rho-associated kinase, ROCK, also localizes to focal adhesions, we examined the role of ROCK in IL-1-induced chemokine responses in IEC cell lines. Suppressing ROCK with the Y27632 inhibitor suppressed IL-1-stimulated Caco-2 cell CXCL8/IL-8 and IEC-6 cell CCL2/MCP-1 secretion and mRNA levels. ROCK inhibition also suppressed IL-1-induced JNK phosphorylation in both cell lines, but high levels of the inhibitor had no significant effect on IL-1-stimulated Caco-2 IκBα phosphorylation and degradation or IKK phosphorylation and kinase activity. Therefore, ROCK may exert an effect on IL-1-stimulated JNK signaling to AP-1 activation, with little effect on IKK/IκBα signaling, defining a potentially important mechanism for regulating IL-1 signaling in IEC that may be essential for optimal cytokine responses.


Asunto(s)
Células Epiteliales/efectos de los fármacos , Interleucina-1/farmacología , Mucosa Intestinal/efectos de los fármacos , Quinasas Asociadas a rho/fisiología , Células CACO-2 , Células Epiteliales/metabolismo , Humanos , Mucosa Intestinal/metabolismo , Proteínas Quinasas JNK Activadas por Mitógenos/metabolismo , FN-kappa B/fisiología , Fosforilación , Transducción de Señal , Quinasas Asociadas a rho/antagonistas & inhibidores
8.
J Prosthodont ; 21(7): 529-34, 2012 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-22672470

RESUMEN

PURPOSE: To simulate coefficient of thermal expansion (CTE)-generated stress fields in monolithic metal and ceramic crowns, and CTE mismatch stresses between metal, alumina, or zirconia cores and veneer layered crowns when cooled from high temperature processing. MATERIALS AND METHODS: A 3D computer-aided design model of a mandibular first molar crown was generated. Tooth preparation comprised reduction of proximal walls by 1.5 mm and of occlusal surfaces by 2.0 mm. Crown systems were monolithic (all-porcelain, alumina, metal, or zirconia) or subdivided into a core (metallic, zirconia, or alumina) and a porcelain veneer layer. The model was thermally loaded from 900°C to 25°C. A finite element mesh of three nodes per edge and a first/last node interval ratio of 1 was used, resulting in approximately 60,000 elements for both solids. Regions and values of maximum principal stress at the core and veneer layers were determined through 3D graphs and software output. RESULTS: The metal-porcelain and zirconia-porcelain systems showed compressive fields within the veneer cusp bulk, whereas alumina-porcelain presented tensile fields. At the core/veneer interface, compressive fields were observed for the metal-porcelain system, slightly tensile for the zirconia-porcelain, and higher tensile stress magnitudes for the alumina-porcelain. Increasingly compressive stresses were observed for the metal, alumina, zirconia, and all-porcelain monolithic systems. CONCLUSIONS: Variations in residual thermal stress levels were observed between bilayered and single-material systems due to the interaction between crown configuration and material properties.


Asunto(s)
Coronas , Diseño de Prótesis Dental , Análisis del Estrés Dental , Coronas con Frente Estético , Óxido de Aluminio , Fuerza Compresiva , Simulación por Computador , Porcelana Dental , Análisis del Estrés Dental/métodos , Análisis de Elementos Finitos , Calor , Humanos , Imagenología Tridimensional , Metales , Diente Molar , Estrés Mecánico , Resistencia a la Tracción , Itrio , Circonio
9.
J Prosthodont ; 21(6): 433-9, 2012 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-22672220

RESUMEN

PURPOSE: The purpose of this study was to test the hypothesis that all-ceramic crown core-veneer system reliability is improved by modifying the core design and as a result is comparable in reliability to metal-ceramic retainers (MCR). Finite element analysis (FEA) was performed to verify maximum principal stress distribution in the systems. MATERIALS AND METHODS: A first lower molar full crown preparation was modeled by reducing the height of proximal walls by 1.5 mm and occlusal surface by 2.0 mm. The CAD-based preparation was replicated and positioned in a dental articulator for specimen fabrication. Conventional (0.5 mm uniform thickness) and modified (2.5 mm height, 1 mm thickness at the lingual extending to proximals) zirconia (Y-TZP) core designs were produced with 1.5 mm veneer porcelain. MCR controls were fabricated following conventional design. All crowns were resin cemented to 30-day aged composite dies, aged 14 days in water and either single-loaded to failure or step-stress fatigue tested. The loads were positioned either on the mesiobuccal or mesiolingual cusp (n = 21 for each ceramic system and cusp). Probability Weibull and use level probability curves were calculated. Crack evolution was followed, and postmortem specimens were analyzed and compared to clinical failures. RESULTS: Compared to conventional and MCRs, increased levels of stress were observed in the core region for the modified Y-TZP core design. The reliability was higher in the Y-TZP-lingual-modified group at 100,000 cycles and 200 N, but not significantly different from the MCR-mesiolingual group. The MCR-distobuccal group showed the highest reliability. Fracture modes for Y-TZP groups were veneer chipping not exposing the core for the conventional design groups, and exposing the veneer-core interface for the modified group. MCR fractures were mostly chipping combined with metal coping exposure. CONCLUSIONS: FEA showed higher levels of stress for both Y-TZP core designs and veneer layers compared to MCR. Core design modification resulted in fatigue reliability response of Y-TZP comparable to MCR at 100,000 cycles and 200 N. Fracture modes observed matched with clinical scenarios.


Asunto(s)
Porcelana Dental , Análisis del Estrés Dental , Coronas con Frente Estético , Aleaciones de Cerámica y Metal , Itrio , Circonio , Simulación por Computador , Diseño Asistido por Computadora , Coronas , Diseño de Prótesis Dental , Análisis del Estrés Dental/métodos , Análisis de Elementos Finitos , Humanos , Análisis de Supervivencia
10.
J Med Act Plants ; 11(1): 1-21, 2022 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-38234457

RESUMEN

Kigelia africana and Garcinia kola are two West African medicinal plants traditionally used to treat or alleviate various medical conditions such as skin ailments, respiratory disorders, and digestive problems. Phytochemical analyses indicated the presence of bioactive constituents, including flavonoids and phenolic acids, suggesting that the extracts of these two plants can interfere with reactive oxygen species-induced oxidative stress, inflammation, and microbial growth. This paper reviews the biochemical properties and the antioxidant, anti-inflammatory, and antibacterial activities of these two relevant West African medicinal plants.

11.
Immunol Invest ; 39(1): 1-15, 2010.
Artículo en Inglés | MEDLINE | ID: mdl-20064081

RESUMEN

Intestinal epithelial cells express the alpha3beta1 integrin which binds to laminin-5. We have previously shown that activation of the alpha3 integrin through laminin-5 binding or a cross-linking antibody results in a suppression of IL-1 induced cytokine secretion and intracellular signaling through IKK to NF-kappaB and JNK to AP-1 in Caco-2 cells. In the present study, the effects of alpha3 integrin activation on the proximal events of IL-1 induced signaling were examined. Monoclonal antibody activation of the alpha3 integrin on Caco-2 cells prior to IL-1 stimulation had no effect on the association of the adapter protein TAB2 with TAK1. However, the association of TRAF6 with TAK1, and TRAF6 with the IL-1 receptor I was significantly suppressed. Activation of the alpha3 integrin had no effect on total levels of TRAF6. Finally, the IL-1 induced formation of higher molecular weight, presumably phosphorylated, forms of IRAK-1 were not altered by alpha3 integrin activation, suggesting that signaling events leading up to IRAK-1 were unaffected. These results suggest that the suppressive effects of alpha3 integrin activation on IL-1 signaling may be due to an effect on the function of TRAF6, preventing the transmission of the signal from the IL-1RI complex to the TAK1 complex.


Asunto(s)
Integrina alfa3/inmunología , Mucosa Intestinal/metabolismo , Receptores de Interleucina-1/metabolismo , Transducción de Señal/efectos de los fármacos , Factor 6 Asociado a Receptor de TNF/metabolismo , Proteínas Adaptadoras Transductoras de Señales/metabolismo , Anticuerpos Monoclonales/farmacología , Células CACO-2 , Humanos , Inmunidad Mucosa , Interleucina-1/inmunología , Interleucina-1/metabolismo , Quinasas Asociadas a Receptores de Interleucina-1/metabolismo , Mucosa Intestinal/efectos de los fármacos , Mucosa Intestinal/inmunología , Quinasas Quinasa Quinasa PAM/metabolismo , Fosforilación , Unión Proteica/efectos de los fármacos , Unión Proteica/inmunología , Transducción de Señal/inmunología
12.
Eur J Oral Sci ; 118(2): 202-9, 2010 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-20487011

RESUMEN

This study evaluated the stress levels at the core layer and the veneer layer of zirconia crowns (comprising an alternative core design vs. a standard core design) under mechanical/thermal simulation, and subjected simulated models to laboratory mouth-motion fatigue. The dimensions of a mandibular first molar were imported into computer-aided design (CAD) software and a tooth preparation was modeled. A crown was designed using the space between the original tooth and the prepared tooth. The alternative core presented an additional lingual shoulder that lowered the veneer bulk of the cusps. Finite element analyses evaluated the residual maximum principal stresses fields at the core and veneer of both designs under loading and when cooled from 900 degrees C to 25 degrees C. Crowns were fabricated and mouth-motion fatigued, generating master Weibull curves and reliability data. Thermal modeling showed low residual stress fields throughout the bulk of the cusps for both groups. Mechanical simulation depicted a shift in stress levels to the core of the alternative design compared with the standard design. Significantly higher reliability was found for the alternative core. Regardless of the alternative configuration, thermal and mechanical computer simulations showed stress in the alternative core design comparable and higher to that of the standard configuration, respectively. Such a mechanical scenario probably led to the higher reliability of the alternative design under fatigue.


Asunto(s)
Coronas , Porcelana Dental/química , Diseño de Prótesis Dental , Coronas con Frente Estético , Itrio/química , Fuerza de la Mordida , Simulación por Computador , Diseño Asistido por Computadora , Análisis del Estrés Dental/instrumentación , Módulo de Elasticidad , Análisis de Elementos Finitos , Humanos , Ensayo de Materiales , Metacrilatos/química , Microscopía Electrónica de Rastreo , Modelos Biológicos , Diente Molar/anatomía & histología , Cementos de Resina/química , Estrés Mecánico , Propiedades de Superficie , Temperatura , Termodinámica , Tionas/química , Preparación Protodóncica del Diente , Circonio
13.
J Biomech Eng ; 132(5): 051001, 2010 May.
Artículo en Inglés | MEDLINE | ID: mdl-20459202

RESUMEN

In a crown system, core fracture requires replacement of the restoration. Understanding maximum principal stress concentration in the veneered core of a tooth-crown system as a function of variations in clinically relevant parameters is crucial in the rational design of crown systems. This study evaluated the main and interacting effects of a set of clinical variables on the maximum principal stress (MPS) in the core of an anatomically correct veneer-core-cement-tooth model. A 3D CAD model of a mandibular first molar crown was generated; tooth preparation was modeled by reducing the proximal walls by 1.5 mm and the occlusal surface by 2.0 mm. A cemented veneered core crown was modeled on the preparation. This "crown system" permitted finite element model investigation of the main and interacting effects of proximal wall height reduction, core material, core thickness, cement modulus, cement thickness, and load position on the maximum stress distribution in a factorial design. Analysis of variance was used to identify the main and interacting influences on the level of MPS in the crown core. Statistical significance was set at p<0.05. MPS levels varied as a function of two-way interactions between the following: core thickness and load position; cement thickness and load position; cement modulus and load position; cement thickness and core thickness; and cement thickness and cement modulus; and also three-way interactions among the load position, core material, and proximal wall height reduction, and among the core thickness, cement thickness, and cement modulus. MPS in the crown-tooth system is influenced by the design parameters and also by the interaction among them. Hence, while the geometry of molar crowns is complex, these analyses identify the factors that influence MPS and suggest levels that will minimize the core MPS in future studies of crown design.


Asunto(s)
Cerámica/química , Cementación , Cementos Dentales/química , Prótesis Dental , Humanos , Diente Molar , Análisis Multivariante , Diente
14.
J Oral Microbiol ; 32011 Mar 09.
Artículo en Inglés | MEDLINE | ID: mdl-21541093

RESUMEN

BACKGROUND: Porphyromonas gingivalis strains are shown to invade human cells in vitro with different invasion efficiencies, varying by up to three orders of magnitude. OBJECTIVE: We tested the hypothesis that invasion-associated interstrain genomic polymorphisms are present in P. gingivalis and that putative invasion-associated genes can contribute to P. gingivalis invasion. DESIGN: Using an invasive (W83) and the only available non-invasive P. gingivalis strain (AJW4) and whole genome microarrays followed by two separate software tools, we carried out comparative genomic hybridization (CGH) analysis. RESULTS: We identified 68 annotated and 51 hypothetical open reading frames (ORFs) that are polymorphic between these strains. Among these are surface proteins, lipoproteins, capsular polysaccharide biosynthesis enzymes, regulatory and immunoreactive proteins, integrases, and transposases often with abnormal GC content and clustered on the chromosome. Amplification of selected ORFs was used to validate the approach and the selection. Eleven clinical strains were investigated for the presence of selected ORFs. The putative invasion-associated ORFs were present in 10 of the isolates. The invasion ability of three isogenic mutants, carrying deletions in PG0185, PG0186, and PG0982 was tested. The PG0185 (ragA) and PG0186 (ragB) mutants had 5.1×10(3)-fold and 3.6×10(3)-fold decreased in vitro invasion ability, respectively. CONCLUSION: The annotation of divergent ORFs suggests deficiency in multiple genes as a basis for P. gingivalis non-invasive phenotype.

15.
J Atheroscler Thromb ; 18(1): 72-81, 2011.
Artículo en Inglés | MEDLINE | ID: mdl-20972353

RESUMEN

AIM: To determine whether culturable bacterial strains are present in human atheromatous tissue and to investigate their properties using culture, quantitative PCR, metagenomic screening, genomic and biochemical methods. METHODS: We analyzed femoral atherosclerotic plaque and five pairs of diseased and healthy arterial tissue for the presence of culturable bacteria using cell cultures and genomic analysis. RESULTS: Gram negative aerobic bacilli were cultivated from the plaque tissue. Ribosomal 16S DNA amplification and sequencing identified the isolates as Enterobacter hormaechei. The isolate was resistant to ampicillin, cefazolin, and erythromycin. A circular 10 kb plasmid was isolated from the strain. Antibiotic protection assays of the isolate demonstrated invasive ability in a human monocytic cell line. To extend the study, five matched pairs of diseased and healthy aortic tissue were analyzed via quantitative PCR. Eubacterial 16S rDNA was detected in all specimens, however, E. hormaechei DNA was detected in surprisingly high numbers in two of the diseased tissues only. CONCLUSIONS: While it is well documented that inflammation is an important risk factor for vascular pathophysiology, the association of bacteria with atherosclerosis has not been clearly established, in large part due to the inability to isolate live bacteria from atheromatous tissue. This is the first study providing direct evidence of Enterobacter spp. associated with atheromatous tissues. The data suggest that chronic infection with bacteria may be an under-reported etiologic factor in vascular pathogenesis. Importantly, characterization of the clinical isolate supports a model of atherogenesis where systemic dissemination of bacteria to atherosclerotic sites may occur via internalization in phagocytic cells.


Asunto(s)
Aterosclerosis/microbiología , Enterobacter/aislamiento & purificación , Anciano , Antibacterianos/farmacología , Secuencia de Bases , Células CACO-2 , Cartilla de ADN , ADN Bacteriano/genética , Farmacorresistencia Microbiana , Enterobacter/efectos de los fármacos , Enterobacter/genética , Humanos , Masculino , Pruebas de Sensibilidad Microbiana , Filogenia , Plásmidos , ARN Ribosómico 16S/genética
16.
Dent Mater ; 26(2): 156-63, 2010 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-19857888

RESUMEN

OBJECTIVE: To evaluate the effects of clinically relevant variables on the maximum principal stress (MPS) in the veneer layer of an anatomically correct veneer-core-cement-tooth model. METHODS: The average dimensions of a mandibular first molar crown were imported into CAD software; a tooth preparation was modeled by reducing the proximal walls by 1.5 mm and the occlusal surface by 2.0 mm. 'Crown systems' were composed by varying characteristics of a cement layer, structural core, and veneer solid, all designed to fit the tooth preparation. The main and interacting effects of proximal wall height reduction, core material, core thickness, cement modulus, cement thickness, and load position on the maximum stress distribution were derived from a series of finite element models and analyzed in a factorial analysis of variance. RESULTS: The average MPS in the veneer layer over the 64 models was 488 MPa (range = 248-840 MPa). MPS increased significantly with the addition of horizontal load components and with increasing cement thickness. In addition, MPS levels varied as a function of interactions between: proximal wall height reduction and load position; load position and cement thickness; core thickness and cement thickness; cement thickness and proximal wall height reduction; and core thickness, cement thickness and proximal wall height reduction. CONCLUSION: Rational design of veneered structural ceramics must consider the complex geometry of the crown-tooth system and integrate the influence of both the main effects and interactions among design parameters.


Asunto(s)
Diseño Asistido por Computadora , Coronas , Diseño de Prótesis Dental , Análisis del Estrés Dental , Óxido de Aluminio , Porcelana Dental , Análisis del Estrés Dental/métodos , Coronas con Frente Estético , Análisis Factorial , Análisis de Elementos Finitos , Humanos , Modelos Lineales , Diente Molar , Cementos de Resina , Circonio
17.
Growth Factors ; 24(4): 285-90, 2006 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-17381070

RESUMEN

Preparations of human sequence recombinant vascular endothelial growth factor-165 (VEGF165) synthesized in Escherichia coli were formulated and lyophilized at NIBSC. Following evaluation at NIBSC, the first preparation, 01/424, has been distributed since 2002 as a NIBSC research reagent, but shows variation between ampoules in the volume and crystalline appearance of the lyophilized plug. A second preparation, 02/286, was subsequently lyophilized in a different formulation. Preparation 02/286 has now been evaluated in a collaborative study for its suitability to serve as a reference standard, and compared with preparation 01/424, by five laboratories using in vitro bioassays or immunoassays. On the basis of the results reported here, the World Health Organization (WHO) established the preparation coded 02/286 as the WHO reference reagent (RR) for human VEGF165, with an assigned unitage of 13,000 units per ampoule.


Asunto(s)
Factor A de Crecimiento Endotelial Vascular/normas , Bioensayo , Línea Celular , Liofilización , Humanos , Estándares de Referencia , Reproducibilidad de los Resultados , Temperatura , Factor A de Crecimiento Endotelial Vascular/análisis , Factor A de Crecimiento Endotelial Vascular/aislamiento & purificación , Organización Mundial de la Salud
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