Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 10 de 10
Filtrar
Más filtros

Banco de datos
Tipo del documento
País de afiliación
Intervalo de año de publicación
1.
Mol Ther ; 21(1): 228-39, 2013 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-23183535

RESUMEN

Nuclear reprogramming of adult somatic tissue enables embryo-independent generation of autologous, patient-specific induced pluripotent stem (iPS) cells. Exploiting this emergent regenerative platform for individualized medicine applications requires the establishment of bioequivalence criteria across derived pluripotent lines and lineage-specified derivatives. Here, from individual patients with type 1 diabetes (T1D) multiple human iPS clones were produced and prospectively screened using a battery of developmental markers to assess respective differentiation propensity and proficiency in yielding functional insulin (INS)-producing progeny. Global gene expression profiles, pluripotency expression patterns, and the capacity to differentiate into SOX17- and FOXA2-positive definitive endoderm (DE)-like cells were comparable among individual iPS clones. However, notable intrapatient variation was evident upon further guided differentiation into HNF4α- and HNF1ß-expressing primitive gut tube, and INS- and glucagon (GCG)-expressing islet-like cells. Differential dynamics of pluripotency-associated genes and pancreatic lineage-specifying genes underlined clonal variance. Successful generation of glucose-responsive INS-producing cells required silencing of stemness programs as well as the induction of stage-specific pancreatic transcription factors. Thus, comprehensive fingerprinting of individual clones is mandatory to secure homogenous pools amenable for diagnostic and therapeutic applications of iPS cells from patients with T1D.


Asunto(s)
Diferenciación Celular , Diabetes Mellitus Tipo 1/patología , Insulina/biosíntesis , Linaje de la Célula , Diabetes Mellitus Tipo 1/metabolismo , Perfilación de la Expresión Génica , Vectores Genéticos , Humanos , Cariotipificación , Análisis de Secuencia por Matrices de Oligonucleótidos , Páncreas/metabolismo , Páncreas/patología , Reacción en Cadena de la Polimerasa , Células Madre/metabolismo , Células Madre/patología
2.
Am J Dermatopathol ; 35(5): 609-12, 2013 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-23715079

RESUMEN

Primary cutaneous folliculotropic melanoma has been described rarely, and there are even fewer published cases of folliculotropic metastases. We report a 54-year-old man with history of primary cutaneous melanoma of the right posterior shoulder, Breslow depth of 3.4 mm, with one positive sentinel lymph node, negative full axillary dissection, and no extranodal metastases at initial staging. Three years later, he presented with an asymptomatic isolated 2-mm blue-black papule on the scalp and was found to have widespread metastatic melanoma involving lymph nodes, liver, adrenal glands, subcutaneous tissue, skeleton, and lung. Histopathologic examination of the scalp lesion demonstrated a tumor nodule composed of sheets and nests of large round to polygonal cells centered about a hair follicle and within follicular epithelium. BRAF V600E gene mutation was documented in this lesion, and the patient received vemurafenib, with dramatic improvement noted on positron emission tomography scan after 2 months of treatment, soon followed by development of extensive metastases, including to brain. Although BRAF mutations have been found in primary and metastatic melanomas of the skin, and in melanoma metastases of extracutaneous sites, to our knowledge, this is the first case of a BRAF mutation documented in folliculotropic metastatic melanoma.


Asunto(s)
Melanoma/genética , Mutación , Proteínas Proto-Oncogénicas B-raf/genética , Neoplasias Cutáneas/genética , Anciano , Anciano de 80 o más Años , Antineoplásicos/uso terapéutico , Análisis Mutacional de ADN , Progresión de la Enfermedad , Femenino , Predisposición Genética a la Enfermedad , Humanos , Indoles/uso terapéutico , Escisión del Ganglio Linfático , Metástasis Linfática , Masculino , Melanoma/enzimología , Melanoma/secundario , Melanoma/terapia , Persona de Mediana Edad , Estadificación de Neoplasias , Cuidados Paliativos , Fenotipo , Inhibidores de Proteínas Quinasas/uso terapéutico , Proteínas Proto-Oncogénicas B-raf/antagonistas & inhibidores , Biopsia del Ganglio Linfático Centinela , Neoplasias Cutáneas/enzimología , Neoplasias Cutáneas/patología , Neoplasias Cutáneas/terapia , Sulfonamidas/uso terapéutico , Factores de Tiempo , Resultado del Tratamiento , Vemurafenib
3.
Arch Dermatol Res ; 313(6): 483-489, 2021 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-32833078

RESUMEN

BACKGROUND: Traditionally, second intent healing (SIH) in the periocular region is reserved for small and/or concave defects, particularly those located on the medial canthus. AIM: The purpose of this study was to identify factors impacting outcomes of SIH for periocular tumors following Mohs micrographic surgery (MMS). METHODS: Retrospective analysis was performed of all periocular lesions treated with MMS followed by SIH from a single academic surgical center over a 5-year period. Data regarding tumor characteristics and follow-up was recorded. The modified Manchester scale was utilized to evaluate scar outcomes. RESULTS: Of the 39 tumors included, 14 (35.9%) were located on the lower eyelid, 12 (30.8%) on the upper eyelid, 6 (15.4%) on the lateral canthus, and 7 (17.9%) on the medial canthus. Involvement of the eyelid margin was seen in 11 (28.2%) of cases. The average defect diameter and area were 1.3 cm and 1.04 cm-squared. Twenty-three cases (59.0%) healed with optimal results. Larger defects were significantly associated with poorer outcomes of SIH (odds ratio 0.205, p = 0.017 by multivariate analysis). Anatomic location, involvement of the lid margin, age, and follow-up interval were not significant factors; however, medial canthus defects were least likely to heal with optimal results. On average, medial canthal lesions were larger in size (mean diameter 1.76 cm, mean area 1.97 cm-squared). CONCLUSIONS: This retrospective study suggests that periorbital defects in all locations with area less than 1.04 cm2 heal well by SIH. In this cohort, larger lesions on the medial canthus healed with worse outcomes.


Asunto(s)
Cicatriz/diagnóstico , Neoplasias de los Párpados/cirugía , Cirugía de Mohs/efectos adversos , Neoplasias Cutáneas/cirugía , Cicatrización de Heridas , Anciano , Anciano de 80 o más Años , Cicatriz/etiología , Neoplasias de los Párpados/patología , Párpados/patología , Párpados/cirugía , Femenino , Estudios de Seguimiento , Humanos , Masculino , Persona de Mediana Edad , Pronóstico , Estudios Retrospectivos , Índice de Severidad de la Enfermedad , Neoplasias Cutáneas/patología , Resultado del Tratamiento
4.
Nucleic Acids Res ; 36(6): 1755-69, 2008 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-18252774

RESUMEN

The c-myb promoter contains multiple GGA repeats beginning 17 bp downstream of the transcription initiation site. GGA repeats have been previously shown to form unusual DNA structures in solution. Results from chemical footprinting, circular dichroism and RNA and DNA polymerase arrest assays on oligonucleotides representing the GGA repeat region of the c-myb promoter demonstrate that the element is able to form tetrad:heptad:heptad:tetrad (T:H:H:T) G-quadruplex structures by stacking two tetrad:heptad G-quadruplexes formed by two of the three (GGA)(4) repeats. Deletion of one or two (GGA)(4) motifs destabilizes this secondary structure and increases c-myb promoter activity, indicating that the G-quadruplexes formed in the c-myb GGA repeat region may act as a negative regulator of the c-myb promoter. Complete deletion of the c-myb GGA repeat region abolishes c-myb promoter activity, indicating dual roles of the c-myb GGA repeat element as both a transcriptional repressor and an activator. Furthermore, we demonstrated that Myc-associated zinc finger protein (MAZ) represses c-myb promoter activity and binds to the c-myb T:H:H:T G-quadruplexes. Our findings show that the T:H:H:T G-quadruplex-forming region in the c-myb promoter is a critical cis-acting element and may repress c-myb promoter activity through MAZ interaction with G-quadruplexes in the c-myb promoter.


Asunto(s)
Proteínas de Unión al ADN/metabolismo , G-Cuádruplex , Genes myb , Regiones Promotoras Genéticas , Proteínas Represoras/metabolismo , Factores de Transcripción/metabolismo , Sitios de Unión , Línea Celular , Regulación hacia Abajo , Humanos , Repeticiones de Trinucleótidos
5.
Dysphagia ; 25(3): 221-30, 2010 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-19856027

RESUMEN

The aim of this study was to develop the Mayo Dysphagia Questionnaire-30 Day (MDQ-30), a tool to measure esophageal dysphagia, by adapting items from validated instruments for use in clinical trials, and assess its feasibility, reproducibility, and concurrent validity. Outpatients referred to endoscopy for dysphagia or seen in a specialty clinic were recruited. Feasibility testing was done to identify problematic items. Reproducibility was measured by test-retest format. Concurrent validity reflects agreement between information gathered in a structured interview versus the patients' written responses. The MDQ-30, a 28-item instrument, took 10 min (range = 5-30 min) to complete. Four hundred thirty-one outpatients [210 (49%) men; mean age = 61 years] participated. Overall, most concurrent validity kappa values for dysphagia were very good to excellent with a median of 0.78 (min 0.28, max 0.95). The majority of reproducibility kappa values for dysphagia were moderate to excellent with a median kappa value of 0.66 (min 0.07, max 1.0). Overall, concurrent validity and reproducibility kappa values for gastroesophageal reflux disease (GERD) symptoms were 0.81 (95% CI = 0.72, 0.91) and 0.66 (95% CI = 0.55, 0.77), respectively. Individual item percent agreement was generally very good to excellent. Internal consistency was excellent. We conclude that the MDQ-30 is an easy-to-complete tool to evaluate reliably dysphagia symptoms over the last 30 days.


Asunto(s)
Trastornos de Deglución/diagnóstico , Adulto , Anciano , Anciano de 80 o más Años , Intervalos de Confianza , Deglución , Trastornos de Deglución/tratamiento farmacológico , Enfermedades del Esófago/diagnóstico , Enfermedades del Esófago/tratamiento farmacológico , Estudios de Factibilidad , Femenino , Indicadores de Salud , Humanos , Masculino , Persona de Mediana Edad , Pacientes Ambulatorios , Reproducibilidad de los Resultados , Factores de Riesgo , Encuestas y Cuestionarios , Adulto Joven
6.
J Drugs Dermatol ; 7(11): 1053-9, 2008 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-19110736

RESUMEN

Systemic glucocorticoids are widely used in dermatologic practice for various conditions including connective tissue and immunobullous diseases, vasculitis, dermatitis, neutrophilic and other dermatoses, and androgen excess syndromes. Long-term use of systemic glucocorticoids has been associated with substantial and rapid bone loss, which places patients at increased risk for bone fractures. Therefore, bone density measurements and the timely initiation of lifestyle modifications and pharmacotherapy are essential for future bone health. The use of several Food and Drug Administration-approved agents to prevent and treat corticosteroid-induced bone loss has been inconsistent among many specialties. In this review, the authors summarize guidelines on the prevention and treatment of corticosteroid-induced bone loss published by the American College of Rheumatology and supplement these guidelines with descriptions of the latest approved pharmacologic therapies and user-friendly flow algorithms. This summary should aid dermatologists in providing education and recommendations regarding bone health for their patients on systemic glucocorticoids.


Asunto(s)
Glucocorticoides/efectos adversos , Osteoporosis/inducido químicamente , Osteoporosis/patología , Animales , Densidad Ósea , Conservadores de la Densidad Ósea/uso terapéutico , Calcio/uso terapéutico , Dermatitis/complicaciones , Dermatitis/tratamiento farmacológico , Glucocorticoides/uso terapéutico , Humanos , Estilo de Vida , Actividad Motora , Osteoporosis/terapia , Teriparatido/uso terapéutico , Vitamina D/uso terapéutico
7.
Oligonucleotides ; 15(1): 36-50, 2005.
Artículo en Inglés | MEDLINE | ID: mdl-15788899

RESUMEN

Antigene oligonucleotides have the potential to regulate gene expression through site-specific DNA binding. However, in vivo applications have been hindered by inefficient cellular uptake, degradation, and strand displacement. Peptide nucleic acids (PNAs) address several of these problems, as they are resistant to degradation and bind DNA with high affinity. We designed two cationic pyrimidine bis-PNAs (cpy-PNAs) to target the polypurine tract of the HER-2/neu promoter and compared them to an unmodified phosphodiester triplex-forming oligonucleotide (TFO1) and a TFO-nitrogen mustard conjugate (TFO2). PNA1 contains a + 2 charge and bound two adjacent 9-bp target sequences with high affinity and specificity, but only at low pH. PNA2 contains a +5 charge and bound one 11-bp target with high affinity up to pH 7.4, but with lower specificity. The PNA:DNA:PNA triplex formed by these cpy-bis-PNAs presented a stable barrier to DNA polymerase extension. The cpy-bis-PNAs and the TFO-alkylator conjugate prevented HER-2/neu transcription in a reporter gene assay (TFO2 = PNA1 > PNA2 >> TFO1). Both PNAs and TFOs were effective at binding the target sequence in naked genomic DNA, but only the TFO-alkylator (TFO2) and the more cationic PNA (PNA2) were detected at the endogenous HER-2/neu promoter in permeabilized cells. This work demonstrates the potential for preventing HER-2/neu gene expression with cpy-bis-PNAs in tumor cells.


Asunto(s)
Regulación de la Expresión Génica , Técnicas Genéticas , Regiones Promotoras Genéticas , Receptor ErbB-2/genética , Receptor ErbB-2/fisiología , Alquilantes/farmacología , Secuencia de Bases , Southern Blotting , Cationes , Línea Celular Tumoral , ADN/química , Cartilla de ADN/química , ADN Polimerasa Dirigida por ADN/química , ADN Polimerasa Dirigida por ADN/metabolismo , Digitonina/farmacología , Relación Dosis-Respuesta a Droga , Células HeLa , Humanos , Concentración de Iones de Hidrógeno , Mecloretamina/farmacología , Datos de Secuencia Molecular , Oligonucleótidos/química , Ácidos Nucleicos de Péptidos/química , Plásmidos/metabolismo , Unión Proteica , Receptor ErbB-2/metabolismo , Transfección
8.
JAMA Dermatol ; 149(9): 1082-6, 2013 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-23824252

RESUMEN

IMPORTANCE: Lichen planus is an autoimmune inflammatory dermatosis that typically affects the skin but can also involve the stratified squamous epithelium of the external auditory canals and tympanic membranes. Here we report our experience with the clinical presentation, diagnosis, and management of otic lichen planus. OBSERVATIONS: We retrospectively reviewed medical records from January 1, 2001, through May 31, 2011, of patients with a diagnosis of otic lichen planus. Nineteen cases were identified (mean age at diagnosis, 57 years; 15 women). The most common concerns were persistent otorrhea and hearing loss. Other symptoms included plugging, pruritus, tinnitus, pain, and bleeding. The mean symptom duration was 4.0 years (n = 13). Most patients responded well to topical tacrolimus within several months. One patient had a dramatic positive response to rituximab. CONCLUSIONS AND RELEVANCE: Otic lichen planus can lead to persistent hearing loss and should be considered in the differential diagnosis of relentless otorrhea and external auditory canal stenosis. In our experience, topical tacrolimus is the best primary treatment, but alternative therapies could be instituted in severe cases. Early recognition of the nonspecific symptoms of otic lichen planus may lead to prompt treatment and avoidance of irreparable late sequelae.


Asunto(s)
Conducto Auditivo Externo/patología , Enfermedades del Oído/fisiopatología , Liquen Plano/fisiopatología , Membrana Timpánica/patología , Adulto , Anciano , Anticuerpos Monoclonales de Origen Murino/uso terapéutico , Diagnóstico Diferencial , Enfermedades del Oído/diagnóstico , Enfermedades del Oído/tratamiento farmacológico , Femenino , Estudios de Seguimiento , Pérdida Auditiva/etiología , Humanos , Factores Inmunológicos/uso terapéutico , Inmunosupresores/administración & dosificación , Inmunosupresores/uso terapéutico , Liquen Plano/diagnóstico , Liquen Plano/tratamiento farmacológico , Masculino , Persona de Mediana Edad , Estudios Retrospectivos , Rituximab , Tacrolimus/administración & dosificación , Tacrolimus/uso terapéutico , Resultado del Tratamiento , Adulto Joven
9.
Stem Cells Transl Med ; 1(6): 451-61, 2012 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-23197849

RESUMEN

The induced pluripotent stem cell (iPSC) technology enables derivation of patient-specific pluripotent stem cells from adult somatic cells without using an embryonic cell source. Redifferentiation of iPSCs from diabetic patients into pancreatic islets will allow patient-specific disease modeling and autologous cell replacement therapy for failing islets. To date, diabetes-specific iPSCs have been generated from patients with type 1 diabetes using integrating retroviral vectors. However, vector integration into the host genome could compromise the biosafety and differentiation propensities of derived iPSCs. Although various integration-free reprogramming systems have been described, their utility to reprogram somatic cells from patients remains largely undetermined. Here, we used nonintegrating Sendai viral vectors to reprogram cells from patients with type 1 and type 2 diabetes (T2D). Sendai vector infection led to reproducible generation of genomic modification-free iPSCs (SV-iPSCs) from patients with diabetes, including an 85-year-old individual with T2D. SV-iPSCs lost the Sendai viral genome and antigens within 8-12 passages while maintaining pluripotency. Genome-wide transcriptome analysis of SV-iPSCs revealed induction of endogenous pluripotency genes and downregulation of genes involved in the oxidative stress response and the INK4/ARF pathways, including p16(INK4a), p15(INK4b), and p21(CIP1). SV-iPSCs and iPSCs made with integrating lentiviral vectors demonstrated remarkable similarities in global gene expression profiles. Thus, the Sendai vector system facilitates reliable reprogramming of patient cells into transgene-free iPSCs, providing a pluripotent platform for personalized diagnostic and therapeutic approaches for diabetes and diabetes-associated complications.


Asunto(s)
Diabetes Mellitus Tipo 1/terapia , Diabetes Mellitus Tipo 2/terapia , Células Madre Pluripotentes Inducidas/metabolismo , Transgenes , Adulto , Anciano , Anciano de 80 o más Años , Células Cultivadas , Cromosomas Humanos/genética , Cromosomas Humanos/metabolismo , Inhibidor p15 de las Quinasas Dependientes de la Ciclina/genética , Inhibidor p15 de las Quinasas Dependientes de la Ciclina/metabolismo , Inhibidor p21 de las Quinasas Dependientes de la Ciclina/genética , Inhibidor p21 de las Quinasas Dependientes de la Ciclina/metabolismo , Diabetes Mellitus Tipo 1/patología , Diabetes Mellitus Tipo 2/patología , Femenino , Regulación de la Expresión Génica , Genes p16 , Vectores Genéticos/genética , Vectores Genéticos/metabolismo , Genoma Viral , Humanos , Células Madre Pluripotentes Inducidas/trasplante , Queratinocitos/citología , Queratinocitos/metabolismo , Lentivirus/genética , Lentivirus/metabolismo , Masculino , Factor 3 de Transcripción de Unión a Octámeros/genética , Factor 3 de Transcripción de Unión a Octámeros/metabolismo , Estrés Oxidativo , Virus Sendai/genética , Virus Sendai/metabolismo , Transducción de Señal , Transcriptoma
10.
Stem Cell Res Ther ; 2(6): 48, 2011 Dec 06.
Artículo en Inglés | MEDLINE | ID: mdl-22142803

RESUMEN

INTRODUCTION: End-stage renal disease (ESRD) is a major public health problem. Although kidney transplantation is a viable therapeutic option, this therapy is associated with significant limitations, including a shortage of donor organs. Induced pluripotent stem (iPS) cell technology, which allows derivation of patient-specific pluripotent stem cells, could provide a possible alternative modality for kidney replacement therapy for patients with ESRD. METHODS: The feasibility of iPS cell generation from patients with a history of ESRD was investigated using lentiviral vectors expressing pluripotency-associated factors. RESULTS: In the present article we report, for the first time, generation of iPS cells from kidney transplant recipients with a history of autosomal-dominant polycystic kidney disease (ADPKD), systemic lupus erythematosus, or Wilms tumor and ESRD. Lentiviral transduction of OCT4, SOX2, KLF4 and c-MYC, under feeder-free conditions, resulted in reprogramming of skin-derived keratinocytes. Keratinocyte-derived iPS cells exhibited properties of human embryonic stem cells, including morphology, growth properties, expression of pluripotency genes and surface markers, spontaneous differentiation and teratoma formation. All iPS cell clones from the ADPKD patient retained the conserved W3842X mutation in exon 41 of the PKD1 gene. CONCLUSIONS: Our results demonstrate successful iPS cell generation from patients with a history of ESRD, PKD1 gene mutation, or chronic immunosuppression. iPS cells from autosomal kidney diseases, such as ADPKD, would provide unique opportunities to study patient-specific disease pathogenesis in vitro.


Asunto(s)
Células Madre Pluripotentes Inducidas/citología , Trasplante de Riñón , Diferenciación Celular , Reprogramación Celular , Fibroblastos/citología , Vectores Genéticos/metabolismo , Humanos , Queratinocitos/citología , Fallo Renal Crónico/metabolismo , Fallo Renal Crónico/terapia , Factor 4 Similar a Kruppel , Factores de Transcripción de Tipo Kruppel/genética , Factores de Transcripción de Tipo Kruppel/metabolismo , Lentivirus/genética , Mutación , Factor 3 de Transcripción de Unión a Octámeros/genética , Factor 3 de Transcripción de Unión a Octámeros/metabolismo , Proteínas Proto-Oncogénicas c-myc/genética , Proteínas Proto-Oncogénicas c-myc/metabolismo , Factores de Transcripción SOXB1/genética , Factores de Transcripción SOXB1/metabolismo , Canales Catiónicos TRPP/genética , Canales Catiónicos TRPP/metabolismo
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA