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1.
Osteoporos Int ; 32(3): 451-465, 2021 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-32935171

RESUMEN

Our aim was to explore change in kyphosis and vertebral fracture incidence following 8 months of high-intensity resistance and impact training (HiRIT) or machine-based isometric axial compression (IAC) training in men with osteopenia and osteoporosis. HiRIT and IAC improved posture. HiRIT participants did not experience progression or incident vertebral fracture. IAC participants did experience progression and incident vertebral fracture. INTRODUCTION: The Lifting Intervention For Training Muscle and Osteoporosis Rehabilitation for Men (LIFTMOR-M) trial examined efficacy and safety of an eight-month, supervised, high-intensity progressive resistance and impact training (HiRIT) program compared with machine-based isometric axial compression (IAC) training in middle-aged and older men with low areal bone mineral density (aBMD). The primary purpose of the current work was to explore change in thoracic kyphosis and incident fracture from vertebral morphology following eight-months of HiRIT or IAC training. The secondary purpose was to explore change in clinical kyphosis measures for HiRIT, IAC and a non-randomized, matched control group. METHODS: Men (≥ 45 yrs), with low aBMD, were recruited and randomized to HiRIT or IAC, or designated control. Clinical measures of thoracic kyphosis with inclinometry were determined. Cobb angle of kyphosis and vertebral fracture assessment using the Genant semi-quantitative method were determined from lateral thoracolumbar DXA (Medix DR, Medilink, France). Per-protocol (n = 40) and intention-to-treat (n = 93) analyses were conducted. RESULTS: Forty participants (HiRIT n = 20, IAC n = 20; 66.1 ± 7.8 yrs.; lumbar spine T-score - 0.1 ± 0.8; femoral neck T-score - 1.5 ± 0.5) underwent clinical kyphosis measures and thoracolumbar DXA at baseline and follow-up. No between-group differences were detected in kyphosis change, however, within-group improvements in neutral (HiRIT - 2.3 ± 0.8°; IAC - 2.5 ± 0.8°) and 'standing tall' (HiRIT - 2.4 ± 0.8°; IAC - 2.0 ± 0.8°) postures were observed (p < 0.05). HiRIT improved Cobb angle (- 3.5 ± 1.5°, p = 0.027) from baseline. Over the 8 months, no incident vertebral fractures nor progression of prevalent vertebral fractures occurred for HiRIT participants. Five incident fractures of thoracic vertebrae occurred for IAC and one wedge fracture progressed. Ninety-three participants underwent clinical kyphosis measures at both time-points (HiRIT n = 34, IAC n = 33, control n = 26). HiRIT exhibited a reduction in 'standing tall' kyphosis compared to control (- 2.3 ± 0.6° versus 1.4 ± 0.7°, p < 0.05), but no other between-group differences were detected. CONCLUSIONS: Although there was no difference in change between intervention groups, thoracic kyphosis appeared to improve in both HiRIT and IAC with exercise exposure. HiRIT improved 'standing tall' posture in comparison to usual activities. HiRIT was not associated with vertebral fracture progression or incident vertebral fracture, but for some IAC participants there was evidence of progression of vertebral fracture severity and incident vertebral fractures, in our small sample. Larger trials are required to confirm the observations of the current work, which was exploratory in nature.


Asunto(s)
Enfermedades Óseas Metabólicas , Cifosis , Osteoporosis , Fracturas de la Columna Vertebral , Anciano , Enfermedades Óseas Metabólicas/etiología , Francia , Humanos , Cifosis/complicaciones , Vértebras Lumbares/lesiones , Masculino , Persona de Mediana Edad , Músculos , Osteoporosis/etiología , Fracturas de la Columna Vertebral/etiología , Vértebras Torácicas/diagnóstico por imagen , Vértebras Torácicas/lesiones
2.
Osteoporos Int ; 30(5): 957-964, 2019 May.
Artículo en Inglés | MEDLINE | ID: mdl-30612163

RESUMEN

Our aim was to assess risk of vertebral fracture during high-intensity resistance and impact training (HiRIT) for postmenopausal women with low bone mass. HiRIT did not induce vertebral fracture, as evidenced by a reduction in kyphosis following 8 months of training and a lack of change in vertebral morphology. INTRODUCTION: The LIFTMOR trial demonstrated a novel, HiRIT program notably improved bone mass in postmenopausal women with osteopenia and osteoporosis. While no clinical signs or symptoms of vertebral crush fracture were evident during the trial, anecdotal feedback suggests that concerns about safety of HiRIT in the osteoporosis demographic remain. The aim of the current work was to assess vertebral body morphology, Cobb angle, and clinical measures of thoracic kyphosis in participants in the LIFTMOR trial for evidence of vertebral fracture following 8 months of supervised HiRIT. METHODS: Participants were randomized to either 8 months of 30-min, twice-weekly, supervised HiRIT or unsupervised, low-intensity, home-based exercise (CON). Lateral thoracolumbar DXA scans (Medix DR, Medilink, France) were performed at baseline and follow-up. Cobb angle was determined, and vertebral fracture identification was performed using the semiquantitative Genant method. Clinical kyphosis measurements were performed in relaxed standing (neutral posture) and standing tall using an inclinometer and a flexicurve. RESULTS: The HiRIT group exhibited a reduction in inclinometer-determined standing tall thoracic kyphosis compared to CON (- 6.7 ± 8.2° vs - 1.6 ± 8.1°, p = 0.031). Both the HiRIT and CON groups exhibited within-group improvement in kyphosis in relaxed standing as measured by both inclinometer and flexicurve (p < 0.05). There were no changes in vertebral fracture classification in the HiRIT group post-intervention. A single, new, wedge deformity was observed for CON. CONCLUSIONS: Supervised HiRIT was not associated with an increased risk of vertebral fracture in postmenopausal women with low bone mass. Indeed, a clinically relevant improvement in thoracic kyphosis was observed following 8 months of supervised HiRIT, further supporting its efficacy as an osteoporosis intervention for postmenopausal women with low to very low bone mass.


Asunto(s)
Terapia por Ejercicio/efectos adversos , Cifosis/rehabilitación , Osteoporosis Posmenopáusica/rehabilitación , Fracturas Osteoporóticas/etiología , Fracturas de la Columna Vertebral/etiología , Absorciometría de Fotón , Anciano , Estatura/fisiología , Densidad Ósea/fisiología , Terapia por Ejercicio/métodos , Femenino , Humanos , Cifosis/etiología , Cifosis/fisiopatología , Vértebras Lumbares/lesiones , Persona de Mediana Edad , Osteoporosis Posmenopáusica/complicaciones , Fracturas Osteoporóticas/fisiopatología , Entrenamiento de Fuerza/efectos adversos , Entrenamiento de Fuerza/métodos , Medición de Riesgo/métodos , Método Simple Ciego , Fracturas de la Columna Vertebral/fisiopatología , Vértebras Torácicas/lesiones
3.
4.
J Neural Transm (Vienna) ; 123(4): 431-8, 2016 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-26852137

RESUMEN

The Mini-Mental State Examination (MMSE) and the Montreal Cognitive Assessment (MoCA) are the most commonly used scales to test cognitive impairment in Lewy body disease (LBD), but there is no consensus on which is best suited to assess cognition in clinical practice and most sensitive to cognitive decline. Retrospective cohort study of 265 LBD patients [Parkinson's disease (PD) without dementia (PDnD, N = 197), PD with dementia (PDD, N = 40), and dementia with Lewy bodies (DLB, N = 28)] from an international consortium who completed both the MMSE and MoCA at baseline and 1-year follow-up (N = 153). Percentage of relative standard deviation (RSD%) at baseline was the measure of inter-individual variance, and estimation of change (Cohen's d) over time was calculated. RSD% for the MoCA (21 %) was greater than for the MMSE (13 %) (p = 0.03) in the whole group. This difference was significant only in PDnD (11 vs. 5 %, p < 0.01), but not in PDD (30 vs. 19 %, p = 0.37) or DLB (15 vs. 14 %, p = 0.78). In contrast, the 1-year estimation of change did not differ between the two tests in any of the groups (Cohen's effect <0.20 in each group). MMSE and MoCA are equal in measuring the rate of cognitive changes over time in LBD. However, in PDnD, the MoCA is a better measure of cognitive status as it lacks both ceiling and floor effects.


Asunto(s)
Trastornos del Conocimiento/diagnóstico , Trastornos del Conocimiento/etiología , Enfermedad por Cuerpos de Lewy/complicaciones , Pruebas Neuropsicológicas , Enfermedad de Parkinson/complicaciones , Anciano , Estudios de Cohortes , Estudios Transversales , Femenino , Estudios de Seguimiento , Humanos , Masculino , Persona de Mediana Edad , Estudios Retrospectivos
5.
Osteoporos Int ; 26(12): 2889-94, 2015 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-26243363

RESUMEN

UNLABELLED: The aim of the LIFTMOR (Lifting Intervention For Training Muscle and Osteoporosis Rehabilitation) trial is to determine the safety and efficacy of brief, bone-targeted, high-intensity progressive resistance training (HiPRT) with impact loading for postmenopausal women with low bone mass. Preliminary findings indicate the LIFTMOR program is safe and effective. INTRODUCTION: Despite a lack of notable efficacy, exercise guidelines for osteoporosis typically recommend moderate-intensity exercises, owing to a perceived risk of fracture from high-intensity loading. Indeed, safety concerns alone have prevented the well-recognised preferential response of bone tissue to high-intensity loads from being applied to those who stand to benefit the most. To progress from this therapeutic stalemate, a challenge to conventional wisdom was required. Our goal was to examine the safety and efficacy of HiPRT and impact loading for risk factors of osteoporotic fracture in postmenopausal women with low to very low bone mass. METHODS: Participants have been randomised to either 8 months of twice-weekly 30-min supervised HiPRT and impact loading or a low-intensity home-based exercise program of the same duration and dose. Testing at baseline and follow-up has included anthropometry; bone, muscle, and fat mass; and functional performance. RESULTS: Twenty-eight women (66.1 ± 4.8 years, mean lumbar spine T-score -2.15 ± 0.72) have completed the study. HiPRT and impact loading (n = 12) improved height (0.4 ± 0.2 cm vs -0.3 ± 0.1 cm, p = 0.003), femoral neck bone mineral density (0.3 ± 0.5 % vs -2.5 ± 0.8 %, p = 0.016), lumbar spine bone mineral density (1.6 ± 0.9 % vs -1.7 ± 0.6 %, p = 0.005), and functional performance (p < 0.05), compared to controls (n = 16). Compliance has been >87 %. There have been no injuries. CONCLUSIONS: Brief supervised HiPRT with impact loading is a safe and effective exercise therapy for postmenopausal women with low to very low bone mass.


Asunto(s)
Osteoporosis Posmenopáusica/rehabilitación , Entrenamiento de Fuerza/métodos , Anciano , Antropometría/métodos , Composición Corporal/fisiología , Densidad Ósea/fisiología , Terapia por Ejercicio/métodos , Femenino , Humanos , Persona de Mediana Edad , Osteoporosis Posmenopáusica/complicaciones , Osteoporosis Posmenopáusica/fisiopatología , Fracturas Osteoporóticas/etiología , Fracturas Osteoporóticas/prevención & control , Cooperación del Paciente/estadística & datos numéricos , Entrenamiento de Fuerza/efectos adversos , Factores de Riesgo , Método Simple Ciego
6.
Neuroimage ; 114: 287-93, 2015 Jul 01.
Artículo en Inglés | MEDLINE | ID: mdl-25862262

RESUMEN

At present, functional magnetic resonance imaging (fMRI) is one of the most useful methods of studying cognitive processes in the human brain in vivo, both for basic science and clinical goals. Although neuroscience studies often rely on group analysis, clinical applications must investigate single subjects (patients) only. Particularly for the latter, issues regarding the reliability of fMRI readings remain to be resolved. To determine the ability of intra-run variability (IRV) weighting to consistently detect active voxels, we first acquired fMRI data from a sample of healthy subjects, each of whom performed 4 runs (4 blocks each) of self-paced finger-tapping. Each subject's data was analyzed using single-run general linear model (GLM), and each block was then analyzed separately to calculate the IRV weighting. Results show that integrating IRV information into standard single-subject GLM activation maps significantly improved the reliability (p=0.007) of the single-subject fMRI data. This suggests that taking IRV into account can help identify the most constant and relevant neuronal activity at the single-subject level.


Asunto(s)
Mapeo Encefálico/métodos , Encéfalo/fisiología , Imagen por Resonancia Magnética/métodos , Adulto , Femenino , Dedos , Humanos , Masculino , Actividad Motora , Reproducibilidad de los Resultados , Adulto Joven
7.
Neuroimage ; 104: 52-8, 2015 Jan 01.
Artículo en Inglés | MEDLINE | ID: mdl-25300200

RESUMEN

Among male patients affected by Kallmann syndrome, a genetically determined disease due to defective neural migration leading to hypogonadropic hypogonadism and hypo/anosmia, about 40% present the peculiar phenomenon of mirror movements, i.e. involuntary movements mirroring contralateral voluntary hand movements. Several pathogenic hypotheses have been proposed, but the ultimate neurological mechanisms are still elusive. The aim of the present study was to investigate brain anatomical substrates of mirror movements in Kallmann syndrome by means of a panel of quantitative MRI analyses. Forty-nine male Kallmann syndrome patients underwent brain MRI. The study protocol included 3D-T1-weighted gradient echo, fluid attenuated inversion recovery and diffusion tensor imaging. Voxel-based morphometry, sulcation, curvature and cortical thickness analyses and tract based spatial statistics were performed using SPM8, Freesurfer and FSL. All patients underwent a complete physical and neurological examination including the evaluation of mirror movements (according to the Woods and Teuber criteria). Kallmann syndrome patients presenting with mirror movements (16/49, 32%) displayed the following brain changes: 1) increased gray matter density in the depth of the left precentral sulcus behind the middle frontal gyrus; 2) decreased cortical thickness in the precentral gyrus bilaterally, in the depth of right precentral sulcus and in the posterior portion of the right superior frontal gyrus; and 3) decreased fractional anisotropy in the left hemisphere involving the temporal lobe and peritrigonal white matter. No differences were shown by cortical curvature and sulcation analyses. The composite array of brain changes observed in Kallmann syndrome patients with mirror movements likely represents the anatomical-structural underpinnings leading to the peculiar derangement of the complex circuitry committed to unilateral hand voluntary movements.


Asunto(s)
Encéfalo/patología , Encéfalo/fisiopatología , Síndrome de Kallmann/patología , Síndrome de Kallmann/fisiopatología , Adolescente , Adulto , Corteza Cerebral/patología , Corteza Cerebral/fisiopatología , Imagen de Difusión Tensora , Globo Pálido/patología , Globo Pálido/fisiopatología , Humanos , Procesamiento de Imagen Asistido por Computador , Imagen por Resonancia Magnética , Masculino , Persona de Mediana Edad , Corteza Motora/patología , Corteza Motora/fisiopatología , Desempeño Psicomotor/fisiología , Tractos Piramidales/patología , Tractos Piramidales/fisiopatología , Adulto Joven
8.
Med. cután. ibero-lat.-am ; 38(3): 121-123, mayo-jun. 2010. ilus
Artículo en Portugués | IBECS | ID: ibc-95609

RESUMEN

Varicela é uma doença de alta prevalência na infância enquanto que na idade adulta é responsável por complicações de correntes de sua reativação.Dentre as complicações mais comuns encontra-se a neuralgia pós-herpética, zoster oftálmico, encefalite herpética e lesão e/ou paralisia de nervos cranianose periféricos. Apresentamos o caso de uma paciente que desenvolveu lesões vesiculares em hemiface esquerda, com comprometimento de conduto auditivo e cavidade oral e paralisia facial periférica, configurando a síndrome de Ramsay Hunt (AU)


Varicella is a highly prevalent disease in childhood, while in adulthood it’s responsible for complications due to its reactivation. Among the most common complications, post-herpetic neuralgia is seen more frequently, followed by ophthalmic zoster, herpetic encephalitis and palsy of cranial and peripheral nerves. We present a patient with hemifacial vesicular lesions, involving the left external auditory canal and oral structures, and peripheral facial paralysis, also known as Ramsay Hunt syndrome (AU)


Asunto(s)
Humanos , Femenino , Anciano , Herpes Zóster Ótico/diagnóstico , Varicela/complicaciones , Herpesvirus Humano 3/patogenicidad , Pérdida Auditiva/virología , Parálisis de Bell/tratamiento farmacológico , Antivirales/uso terapéutico
9.
Toxicol Lett ; 176(2): 93-103, 2008 Jan 30.
Artículo en Inglés | MEDLINE | ID: mdl-18077114

RESUMEN

Although human populations are continuously exposed to complex mixtures of contaminants, the effects of such exposure on the developing brain transcriptome are poorly characterized. Rats were exposed perinatally to the northern contaminant mixture (NCM) which was designed to reflect the blood contaminant profile of Canadian arctic populations, to components of the NCM administered separately (methylmercury (MeHg), polychlorinated biphenyls (PCBs) and organochlorine pesticides (OCs)) or to the goitrogen propylthiouracyl. Post-natal day (PND) 14 cerebellum global gene expression resulting from such exposures was investigated using high-density cDNA microarrays. Fifty known genes were identified as differentially expressed between the control group and at least one other treatment group. The microarray data were validated by quantitative PCR (qPCR) on a subset of 10 genes. The differentially expressed genes are involved in a variety of processes, including nerve cell differentiation, migration, myelination and synaptic transmission. The comparison of cerebellum gene expression profiles resulting from exposure to the NCM and its individual components in male and female pups revealed that (i) gender is a crucial biological variable influencing genomic response to environmental contaminants and (ii) contaminant co-exposure significantly masks the effects of individual mixture components on cerebellum gene expression.


Asunto(s)
Cerebelo/efectos de los fármacos , Contaminantes Ambientales/toxicidad , Perfilación de la Expresión Génica/métodos , Plaguicidas/toxicidad , Animales , Animales Recién Nacidos , Proteínas de Unión al Calcio/genética , Cerebelo/metabolismo , Análisis por Conglomerados , Contaminantes Ambientales/química , Proteínas de la Matriz Extracelular/genética , Femenino , Factores de Intercambio de Guanina Nucleótido/genética , Hidrocarburos Clorados/química , Hidrocarburos Clorados/toxicidad , Lactancia , Masculino , Exposición Materna , Compuestos de Metilmercurio/química , Compuestos de Metilmercurio/toxicidad , Neuropéptidos/genética , Análisis de Secuencia por Matrices de Oligonucleótidos/métodos , Plaguicidas/química , Plaguicidas/clasificación , Bifenilos Policlorados/química , Bifenilos Policlorados/toxicidad , Embarazo , Ratas , Ratas Sprague-Dawley , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Proteínas Ribosómicas/genética , Factores Sexuales
10.
Clin Imaging ; 24(1): 15-8, 2000.
Artículo en Inglés | MEDLINE | ID: mdl-11120412

RESUMEN

A case of a parosteal lipoma of the thigh is presented. Very little is known of the enhancement features of this tumor. In this case, mild enhancement of tissue in the region of the pedicle between reactive cortical bone hyperostosis and the lipomatous mass corresponded to fibrous tissue that outlined the hyperostotic reactive bone.


Asunto(s)
Neoplasias Óseas/diagnóstico , Lipoma/diagnóstico , Imagen por Resonancia Magnética , Periostio/patología , Adulto , Neoplasias Óseas/patología , Neoplasias Óseas/cirugía , Medios de Contraste , Humanos , Lipoma/patología , Lipoma/cirugía , Imagen por Resonancia Magnética/métodos , Masculino , Periostio/cirugía , Muslo
11.
Am J Community Psychol ; 28(5): 731-55, 2000 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-11043112

RESUMEN

This paper takes up a theoretical and empirical investigation of how two community-based projects for young women both create safety from community and domestic violence but how, in the process, discourses of multicultural inclusion define one site, and racist discourses of exclusion float through the other site. By relying on two intensive qualitative case studies of community-based organizations for girls, one exclusively White and working class and the other expressly multicultural and antiracist, we try to identify those structures and practices that support feminist, but inadvertently racist, work and those structures and practices that enable, at once, feminist and antiracist consciousness and praxis.


Asunto(s)
Relaciones Comunidad-Institución , Feminismo , Adolescente , Diversidad Cultural , Violencia Doméstica/prevención & control , Femenino , Humanos
12.
Adolesc Med ; 10(3): 451-8, xii, 1999 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-10611942

RESUMEN

Malignant bone tumors in the adolescent population are rare but serious problems that are both life- and limb-threatening. Most of these tumors originate in the extremities, hip girdle, or pelvic girdle and require complete surgical resection for adequate therapy. The greatest majority of these tumors are diagnosed as osteogenic sarcomas. In the past, limb ablation was the only effective therapeutic option available to surgical oncologists in adolescent osteosarcoma patients. However, today, after two decades of advances in chemotherapy protocols and reconstructive surgical techniques, limb-salvage surgery has become an accepted treatment standard. Because skeletal immaturity and future bone growth is generally not a major reconstructive consideration in adolescents, 90% of the patients in this age group are today treated with limb-sparing surgery. The most significant question regarding the successful use of limb-salvage surgery is whether it adversely affects long-term outcome compared with standard amputations. The principal studies, both single- and multi-institutional, that compared the risk of local tumor recurrence and overall disease-free survival rate of the two types of procedures, demonstrated no significant difference in disease-free survival rates between the two groups. Similarly, multivariant analyses have shown no survival benefit for choice of surgical procedure in osteosarcoma patients. As a result, limb-sparing surgery for osteosarcoma patients has now been firmly established as a safe, effective, and successful oncology procedure compared with limb ablation.


Asunto(s)
Neoplasias Óseas/cirugía , Osteosarcoma/cirugía , Adolescente , Amputación Quirúrgica , Terapia Combinada , Supervivencia sin Enfermedad , Extremidades/cirugía , Humanos , Recurrencia Local de Neoplasia
13.
Environ Health Perspect ; 106 Suppl 4: 975-81, 1998 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-9703481

RESUMEN

Cancer is a multistage multimechanism process involving gene and/or chromosomal mutations (genotoxic events), altered gene expression at the transcriptional, translational, and post-translational levels (epigenetic events), and altered cell survival (proliferation and apoptosis or necrosis), resulting in an imbalance of the organism's homeostasis. Maintenance of the organism's homeostasis depends on the intricate coordination of genetic and metabolic events between cells via extracellular and intercellular communication mechanisms. The release of a quiescent cell, whether normal or premalignant, from the suppressing effects of communicating neighbors requires the downregulation of intercellular communication via gap junctions, thereby allowing factors that control intracellular events to exceed a critical mass necessary for the cell to either proliferate or undergo apoptosis. Therefore, determining the role an environmental pollutant must play in the multistage carcinogenic process includes mechanisms of epigenetic toxicity such as the effects of a compound on gap junctional intercellular communication (GJIC). A classic example of a class of compounds in which determination of carcinogenicity focused on genotoxic events and ignored epigenetic events is polycyclic aromatic hydrocarbons (PAHs). The study of structure-activity relationships of PAHs has focused exclusively on the genotoxic and tumor-initiating properties of the compound. We report on the structure-activity relationships of two- to four-ringed PAHs on GJIC in a rat liver epithelial cell line. PAHs containing a bay or baylike region were more potent inhibitors of GJIC than the linear PAHs that do not contain these regions. These are some of the first studies of determine the epigenetic toxicity of PAHs at the epigenetic level.


Asunto(s)
Comunicación Celular/efectos de los fármacos , Uniones Comunicantes/efectos de los fármacos , Hidrocarburos Policíclicos Aromáticos/efectos adversos , Animales , Biomarcadores , Carcinógenos , Transformación Celular Neoplásica , Exposición a Riesgos Ambientales , Uniones Comunicantes/fisiología , Hígado/efectos de los fármacos , Neoplasias/etiología , Hidrocarburos Policíclicos Aromáticos/química , Hidrocarburos Policíclicos Aromáticos/farmacología , Ratas , Relación Estructura-Actividad
14.
J Biol Chem ; 273(12): 7134-40, 1998 Mar 20.
Artículo en Inglés | MEDLINE | ID: mdl-9507027

RESUMEN

A procedure to immunoaffinity purify the human transcription factor IIH (TFIIH) was developed using a monoclonal antibody that recognizes an epitope in ERCC3 (XPB), the largest subunit of TFIIH. The epitope recognized by the monoclonal antibody was mapped to 20 amino acids. A peptide containing the epitope was capable of displacing TFIIH from an immunoaffinity column containing the monoclonal antibody. The immunoaffinity purification procedure described allows a simple and efficient method to purify both the "core" and "holo" TFIIH complexes.


Asunto(s)
Cromatografía de Afinidad/métodos , Factores de Transcripción TFII , Factores de Transcripción/aislamiento & purificación , Anticuerpos Monoclonales/inmunología , Mapeo Epitopo , Epítopos/inmunología , Humanos , Factor de Transcripción TFIIH , Factores de Transcripción/química , Factores de Transcripción/inmunología
15.
Environ Health Perspect ; 106(1): 17-22, 1998 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-9417772

RESUMEN

Many polycyclic aromatic hydrocarbons (PAHs) are known carcinogens, and a considerable amount of research has been devoted to predicting the tumor-initiating potential of PAHs based on chemical structure. However, there has been little research into the effects of PAHs on the epigenetic events of tumor promotion and no structural correlation has been made thereof. Gap junctional intercellular communication (GJIC) activity was used in this study as an epigenetic biomarker to determine the structure-activity relationships of twelve different PAHs. The PAHs used were naphthalene, 1-methylnaphthalene, 2-methylnaphthalene, anthracene, 1-methylanthracene, 2-methylanthracene, 9-methylanthracene, 9, 10-dimethylanthracene, phenanthrene, fluorene, 1-methylfluorene, and fluoranthene. Results showed that PAHs containing bay or baylike regions inhibited GJIC more than did the linear PAHs. The nonnaphthalene PAHs were not cytotoxic as determined by a vital dye uptake assay, but the naphthalene compounds were cytotoxic at the higher doses, indicating that the down regulation of GJIC by these naphthalenes could be a consequence of general membrane damage. Inhibition of GJIC by all the inhibitory PAHs was reversed when the cells were refreshed with PAH-free growth medium. Inhibition of GJIC occurred within 0.5-5 min and correlated with the aqueous solubility of the PAHs. The present study revealed that there are structural determinants of epigenetic toxicity as determined by GJIC activity.


Asunto(s)
Región Bahía de Hidrocarburos Aromáticos Policíclicos , Comunicación Celular/efectos de los fármacos , Uniones Comunicantes/efectos de los fármacos , Hidrocarburos Policíclicos Aromáticos/química , Hidrocarburos Policíclicos Aromáticos/toxicidad , Algoritmos , Animales , Línea Celular , Supervivencia Celular/efectos de los fármacos , Hígado/metabolismo , Ratas , Ratas Endogámicas F344 , Factores de Tiempo
16.
Mol Cell Biol ; 17(6): 2973-84, 1997 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-9154795

RESUMEN

Two promoter elements, the TATA element and initiator (Inr), are capable of directing specific transcription initiation of protein-encoding genes by RNA polymerase II (RNAPII). Although binding to the TATA element by the TATA-binding protein (TBP) has been shown to be the initial recognition step in transcription complex formation in vitro, the mechanism through which the basal machinery assembles into a functional complex on TATA-less promoters is controversial. Evidence supporting numerous models of Inr-mediated transcription complex formation exists, including the nucleation of a complex by Inr-binding proteins, a component of the TFIID complex, or a specific upstream activator common to many TATA-less promoters, Sp1. Using various techniques, we have undertaken a systematic analysis of the natural TATA-less human DNA polymerase beta (beta-pol) gene promoter. Although the beta-pol promoter contains upstream Sp1 elements and a functional Inr that binds YY1, neither of these factors is essential for Inr-mediated transcription complex formation. A complex containing TBP, TFIIB, TFIIF, and RNAPII (DBPolF complex) is capable of forming on the promoter in an Inr-dependent manner. A single point mutation within the Inr that affects DBPolF complex formation diminishes beta-pol transcriptional activity.


Asunto(s)
Proteínas de Unión al ADN/metabolismo , Regiones Promotoras Genéticas , ARN Polimerasa II/metabolismo , Factor de Transcripción Sp1/metabolismo , TATA Box , Factores de Transcripción/metabolismo , Transcripción Genética , Sitios de Unión , ADN Polimerasa I/genética , Factores de Unión al ADN Específico de las Células Eritroides , Humanos , Proteínas Nucleares/metabolismo , Proteína de Unión a TATA-Box , Factor de Transcripción TFIID , Factores de Transcripción TFII/metabolismo , Factor de Transcripción YY1 , Dedos de Zinc
17.
Clin Imaging ; 21(1): 63-8, 1997.
Artículo en Inglés | MEDLINE | ID: mdl-9117935

RESUMEN

Parosteal osteogenic sarcoma is an unusual tumor in young children. It usually has a tendency to affect people with mature skeletons. The biological behavior of this tumor in children appears to be identical to that in adults, resulting in excellent prognosis after curative operative procedures, even if there is minimal extension to the bone marrow. Magnetic resonance imaging has a significant role in staging the tumor, as other imaging modalities are inferior in demonstrating early bone marrow involvement.


Asunto(s)
Neoplasias Óseas/diagnóstico , Fémur/patología , Imagen por Resonancia Magnética , Osteosarcoma/diagnóstico , Biopsia , Neoplasias Óseas/cirugía , Niño , Femenino , Fémur/diagnóstico por imagen , Fémur/cirugía , Estudios de Seguimiento , Humanos , Rodilla/diagnóstico por imagen , Rodilla/patología , Rodilla/cirugía , Osteosarcoma/cirugía , Radiografía
18.
Fundam Appl Toxicol ; 34(2): 260-4, 1996 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-8954755

RESUMEN

Polycyclic aromatic hydrocarbons (PAHs), many of which are known carcinogens, are derived from the pyrolysis of organic materials. A rich source of PAHs is cigarette smoke, which contains methylated anthracenes and phenanthrenes as the predominant PAHs. The tumor-promoting activity of cigarette smoke has been well documented. The down-regulation of gap junction intercellular communication (GJIC) by nongenotoxic chemicals and several oncogenes has been implicated in tumor promotion. Therefore, we determined the effects of the three isomers of methylanthracene on GJIC in WB-F344 rat liver epithelial cells. Anthracene and 2-methylanthracene did not significantly inhibit GJIC, whereas anthracene methylated in the 1 or 9 position reversibly inhibited GJIC with I50 values of 22 and 36 microM, respectively. Inhibition occurred within 15 min. In conclusion, the biological effect of methylanthracene depends on the ring position of the methyl group, and these inhibitory isomers could play a potential role in tumor promotion of methylated PAH-rich mixtures such as cigarette smoke and crude oil products.


Asunto(s)
Antracenos/toxicidad , Comunicación Celular/efectos de los fármacos , Uniones Comunicantes/efectos de los fármacos , Hígado/citología , Hígado/efectos de los fármacos , Animales , Supervivencia Celular/efectos de los fármacos , Células Cultivadas , Regulación hacia Abajo/efectos de los fármacos , Células Epiteliales , Epitelio/efectos de los fármacos , Metilación , Ratas , Ratas Endogámicas F344 , Relación Estructura-Actividad
20.
Perit Dial Int ; 16 Suppl 1: S521-5, 1996.
Artículo en Inglés | MEDLINE | ID: mdl-8728262

RESUMEN

Enteral nutritional support is an important component of the care provided to infants receiving long-term peritoneal dialysis. In the majority of published experiences on this subject, the use of the nasogastric tube has facilitated the provision of required calorie and protein intake and resulted in an improved patient outcome. Advantages of the nasogastric route of nutritional support include the ease of administration, while recurrent emesis remains the most troublesome and frequent short-term complication associated with its use. Impaired oral-motor development may also result from nonoral feeding and should be addressed throughout the course of tube feeding.


Asunto(s)
Nutrición Enteral/métodos , Fallo Renal Crónico/terapia , Diálisis Peritoneal Ambulatoria Continua/métodos , Desnutrición Proteico-Calórica/terapia , Terapia Combinada , Humanos , Lactante , Recién Nacido , Fallo Renal Crónico/etiología , Necesidades Nutricionales , Desnutrición Proteico-Calórica/etiología , Resultado del Tratamiento
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