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1.
Gen Comp Endocrinol ; 245: 44-54, 2017 05 01.
Artículo en Inglés | MEDLINE | ID: mdl-28185934

RESUMEN

Corticosteroids play positive or negative role in the reproductive mechanisms of many fish species but the physiological contexts relating to such biphasic actions are not well defined. In the present study we investigated to what extent corticosteroids (cortisol-Co, 11-deoxycorticosterone-DOC) hormones may interfere with the steroidogenic capacity of Eurasian perch ovarian tissues, and we tested whether the negative effects of corticosteroids may be mitigated by potential stimulating endocrine factors, namely insulin-like growth factor-1 (IGF), human chorionic gonadotropin (HCG) or thyroid hormones (Triidothyronine-T3, thyroxine-T4). Ovarian tissues from six maturing fish at late vitellogenesis developmental stage (LVO) or at the start of the final meiotic oocyte maturation (FMO) were incubated during 6h in Cortland medium containing various endocrine compounds. Both corticosteroids drastically suppressed aromatase activity (AA) and sex-steroid production, namely 17-ß estradiol (E2), 17α-20ß-dihydroxy-4-pregnen-3-one (DHP) and testosterone (T). HCG significantly prevented the suppression of both AA and sex-steroid production by low and high cortisol doses, but a lesser AA protection was observed in the case of DOC. The protection of DHP and T productions by HCG from the negative effects by the two corticosteroids was higher at FMO than at LVO stage. IGF or thyroid hormone treatments were lesser effective or ineffective in mitigating the suppression of AA or sex-steroid production by cortisol. The results suggest that an increase in cortisol or DOC such as after mild or high stress intensity may inhibit drastically the ovarian steroidogenic capacity whatever the final oocyte maturation stage in percid fish by hampering AA and sex-steroid production. That inhibition may be partly mitigated by gonadotropins but not IGF nor thyroid hormones, especially at final meiotic oocyte maturation stage.


Asunto(s)
Desoxicorticosterona/farmacología , Hormonas Esteroides Gonadales/metabolismo , Hidrocortisona/farmacología , Percas/fisiología , Animales , Aromatasa/genética , Aromatasa/metabolismo , Femenino , Regulación Enzimológica de la Expresión Génica/efectos de los fármacos , Hormonas Esteroides Gonadales/genética , Humanos , Oocitos/crecimiento & desarrollo , Ovario/efectos de los fármacos , Ovario/metabolismo , Receptor IGF Tipo 1/farmacología , Tiroxina/farmacología , Técnicas de Cultivo de Tejidos , Triyodotironina/farmacología
2.
J Appl Microbiol ; 120(2): 469-77, 2016 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-26599136

RESUMEN

AIMS: To develop a rapid test for thermotolerant Campylobacter in poultry faeces. METHODS AND RESULTS: The reported method is based on immunomagnetic separation and loop-mediated isothermal DNA amplification (IMS/LAMP). This LAMP assay is specific (demonstrated using 10 Campylobacter strains and 13 non-Campylobacter bacterial species) and sensitive (95% probability of detecting 22 genome copies). A competitive internal amplification control (IAC) has been incorporated to give unambiguous determination of negative results. Immunoseparation of Campylobacter allows direct LAMP detection from poultry boot swab samples in 90 min without enrichment or DNA purification (74% probability of detecting 10(4) CFU ml(-1) of a boot swab suspension). The analysis of 17 samples from commercial turkey farms showed 100% correlation with parallel results obtained by standard microbiological methods. CONCLUSIONS: A rapid test has been developed for direct detection of thermotolerant Campylobacter spp. in boot swab samples, thus bypassing culture enrichment or DNA extraction. The test has potential to be carried out by farm personnel on site. SIGNIFICANCE AND IMPACT OF THE STUDY: The method offers an inexpensive approach to monitor poultry infection in near real time, assisting flock management and controls to prevent introduction of Campylobacter into the food chain.


Asunto(s)
Infecciones por Campylobacter/veterinaria , Campylobacter/aislamiento & purificación , Separación Inmunomagnética/métodos , Técnicas de Amplificación de Ácido Nucleico/métodos , Enfermedades de las Aves de Corral/microbiología , Animales , Campylobacter/clasificación , Campylobacter/genética , Infecciones por Campylobacter/diagnóstico , Infecciones por Campylobacter/microbiología , Pollos/microbiología , Heces/microbiología , Enfermedades de las Aves de Corral/diagnóstico , Sensibilidad y Especificidad , Pavos/microbiología
3.
Childs Nerv Syst ; 32(10): 1875-93, 2016 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-27659830

RESUMEN

Insula and paralimbic region represent a common location for gliomas in adulthood. However, limbic and paralimbic tumors are rare in children. Reports of pediatric insular tumors are scarce in literature, and most of them are included in adult's series, so their management and outcome can be outlined only after extracting data from these reports. Due to their predominantly low grade, they usually have a benign course for some time, what make them ideal candidates for total resection. However, their intricate location and spread to key areas, including the temporal lobe, make them a surgical challenge. The transsylvian route, with or without resection of the frontal and/or temporal operculae, which requires exposure of part or all of the insula is commonly selected for insular tumor approaches. Intraoperative functional mapping is a standard procedure for resection of central region tumors in adults. In children and young individuals, awake craniotomy is not always possible and surgical planning usually relay on functional and anatomical preoperative studies. The main goal when approaching an insular tumor is to achieve the largest extent of resection to increase overall patient survival while preserving the functional status, minimizing postoperative morbidity and increasing the quality of life. The extent of resection seems to be correlated also with the control of associated (and usually intractable) epilepsy.


Asunto(s)
Neoplasias Encefálicas/patología , Neoplasias Encefálicas/cirugía , Corteza Cerebral/patología , Lateralidad Funcional/fisiología , Glioma/patología , Glioma/cirugía , Procedimientos Neuroquirúrgicos/métodos , Neoplasias Encefálicas/diagnóstico por imagen , Corteza Cerebral/diagnóstico por imagen , Corteza Cerebral/cirugía , Glioma/diagnóstico por imagen , Humanos , Imagen por Resonancia Magnética
4.
Radiologia ; 55(6): 505-13, 2013.
Artículo en Inglés, Español | MEDLINE | ID: mdl-22521686

RESUMEN

OBJECTIVE: To describe the detection of cortical areas and subcortical pathways involved in language observed in MRI activation studies and tractography in a 3T MRI scanner and to correlate the findings of these functional studies with direct intraoperative cortical and subcortical stimulation. MATERIAL AND METHODS: We present a series of 14 patients with focal brain tumors adjacent to eloquent brain areas. All patients underwent neuropsychological evaluation before and after surgery. All patients underwent MRI examination including structural sequences, perfusion imaging, spectroscopy, functional imaging to determine activation of motor and language areas, and 3D tractography. All patients underwent cortical mapping through cortical and subcortical stimulation during the operation to resect the tumor. Postoperative follow-up studies were done 24 hours after surgery. RESULTS: The correlation of motor function and of the corticospinal tract determined by functional MRI and tractography with intraoperative mapping of cortical and subcortical motor areas was complete. The eloquent brain areas of language expression and reception were strongly correlated with intraoperative cortical mapping in all but two cases (a high grade infiltrating glioma and a low grade glioma located in the frontal lobe). 3D tractography identified the arcuate fasciculus, the lateral part of the superior longitudinal fasciculus, the subcallosal fasciculus, the inferior fronto-occipital fasciculus, and the optic radiations, which made it possible to mark the limits of the resection. The correlation with the subcortical mapping of the anatomic arrangement of the fasciculi with respect to the lesions was complete. CONCLUSION: The best treatment for brain tumors is maximum resection without associated deficits, so high quality functional studies are necessary for preoperative planning.


Asunto(s)
Mapeo Encefálico/métodos , Neoplasias Encefálicas/fisiopatología , Corteza Cerebral/fisiopatología , Imagen de Difusión Tensora , Estimulación Eléctrica , Cuidados Intraoperatorios , Lenguaje , Imagen por Resonancia Magnética , Humanos , Estudios Retrospectivos
5.
JID Innov ; 2(3): 100107, 2022 May.
Artículo en Inglés | MEDLINE | ID: mdl-35990535

RESUMEN

Atopic dermatitis (AD) is a chronic, itchy skin condition that affects 15-20% of children but may occur at any age. It is estimated that 16.5 million US adults (7.3%) have AD that initially began at age >2 years, with nearly 40% affected by moderate or severe disease. Therefore, a quantitative measurement that tracks the evolution of AD severity could be extremely useful in assessing patient evolution and therapeutic efficacy. Currently, SCOring Atopic Dermatitis (SCORAD) is the most frequently used measurement tool in clinical practice. However, SCORAD has the following disadvantages: (i) time consuming-calculating SCORAD usually takes about 7-10 minutes per patient, which poses a heavy burden on dermatologists and (ii) inconsistency-owing to the complexity of SCORAD calculation, even well-trained dermatologists could give different scores for the same case. In this study, we introduce the Automatic SCORAD, an automatic version of the SCORAD that deploys state-of-the-art convolutional neural networks that measure AD severity by analyzing skin lesion images. Overall, we have shown that Automatic SCORAD may prove to be a rapid and objective alternative method for the automatic assessment of AD, achieving results comparable with those of human expert assessment while reducing interobserver variability.

6.
Artículo en Inglés | MEDLINE | ID: mdl-35805859

RESUMEN

This is a preliminary study conducted to analyze the presence and concentration of pesticides in honey obtained from honey bee colonies located in two regions with managed ecosystems that differ in the intensity and technification of agricultural practices. Fourteen pesticides at variable concentrations were detected in 63% of the samples analyzed. The pesticides most frequently found at higher concentrations were insecticides (neonicotinoids, followed by organophosphates), herbicides, and fungicides. The number, frequency, and concentration of pesticides were higher in samples collected from hives located where intensive and highly-technified agriculture is practiced. Forty-three percent of the samples from that zone had residues of imidacloprid, compared with only 13% of the samples from the less-technified zone. Furthermore, 87.5% of those samples had imidacloprid concentrations that were above sublethal doses for honey bees (>0.25 ng/g) but that are not considered hazardous to human health by the European Commission. The results of this study suggest that honey can be used as a bioindicator of environmental contamination by pesticides, which highlights the need to continue monitoring contaminants in this product to determine the risks of pesticide impacts on pollinator health, on ecosystems, and on their potential implications to human health and other non-target organisms.


Asunto(s)
Insecticidas , Plaguicidas , Agricultura , Animales , Abejas , Ecosistema , Humanos , Insecticidas/análisis , Insecticidas/toxicidad , Neonicotinoides
7.
Artículo en Inglés, Español | MEDLINE | ID: mdl-32741686

RESUMEN

Medial discoid meniscus is a rare entity with a reported incidence of 0.12 to 0.3%, although the real incidence may be greater because not all the patients are symptomatic. Like lateral discoid menisci, medial discoid menisci are prone to degeneration that may prompt the presence of mechanical symptoms at early age. We present the case of a 14 year old male patient with bilateral knee symptoms of insidious onset without a traumatic event. Magnetic resonance revealed bilateral medial discoid menisci. Arthroscopic medial meniscus remodelling was performed in the right knee and, three months later, in the left knee, due to limitating mechanical symptoms. At the latest follow up -6 months for the right knee, 3 months for the left knee-, the patient resumed his sports activities.


Asunto(s)
Artroscopía , Enfermedades de los Cartílagos/cirugía , Artropatías/cirugía , Articulación de la Rodilla/cirugía , Meniscos Tibiales/cirugía , Adolescente , Humanos , Masculino
8.
Am J Transplant ; 9(12): 2837-44, 2009 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-19845593

RESUMEN

Blockade of the B7: CD28 costimulatory pathway has emerged as a promising therapy to prevent allograft rejection. However, this pathway has also been demonstrated to be important for the generation and maintenance of regulatory T cells. In this study, we investigated the role of the B7: CD28 pathway in the 'bm12 into B6' MHC class II-mismatched vascularized cardiac transplant model of chronic rejection. Allograft rejection was remarkably accelerated in B6 background B7DKO and CD28KO recipients compared with B6 wild-type (WT) recipients. Allograft rejection was associated with a significantly enhanced Th1/Th2 alloreactivity and marked reduction in the ratio of regulatory T cells to CD4(+) effector/memory cells. We noted that administration of anti-B7-1 and anti-B7-2 mAb prior to transplantation also accelerated allograft rejection. Furthermore, depleting CD25(+) cells in B6 WT recipients of bm12 hearts prior to transplant also precipitated rejection at a similar rate. Neither B7/CD28 deficiency nor CD25 depletion affected graft survival in single MHC class I-mismatched (bm1 into B6) recipients. This study highlights the paradoxical functions of B7: CD28 costimulation in a MHC class II-mismatched model, in which the B7: CD28 pathway is demonstrated to be important in preventing rejection through the generation and maintenance of Tregs.


Asunto(s)
Antígeno B7-1/inmunología , Antígenos CD28/inmunología , Rechazo de Injerto/inmunología , Trasplante de Corazón/inmunología , Linfocitos T Reguladores/inmunología , Animales , Anticuerpos Monoclonales/inmunología , Genes MHC Clase II , Supervivencia de Injerto/inmunología , Ratones , Ratones Noqueados , Células TH1/inmunología , Células Th2/inmunología
9.
Science ; 248(4961): 1402-5, 1990 Jun 15.
Artículo en Inglés | MEDLINE | ID: mdl-2192455

RESUMEN

The bacterial photosynthetic reaction center (RC) is a pigmented intrinsic membrane protein that performs the primary charge separation event of photosynthesis, thereby converting light to chemical energy. The RC pigments are bound primarily by two homologous peptides, the L and M subunits, each containing five transmembrane helices. These alpha helices and pigments are arranged in an approximate C2 symmetry and form two possible electron transfer pathways. Only one of these pathways is actually used. In an attempt to identify nonhomologous residues that are responsible for functional differences between the two branches, homologous helical regions that interact extensively with the pigments were genetically symmetrized (that is, exchanged). For example, replacement of the fourth transmembrane helix (D helix) in the M subunit with the homologous helix from the L subunit yields photosynthetically inactive RCs lacking a critical photoactive pigment. Photosynthetic revertants have been isolated in which single amino acid substitutions (intragenic suppressors) compensate for this partial symmetrization.


Asunto(s)
Proteínas Bacterianas , Secuencia de Aminoácidos , Proteínas Bacterianas/genética , Clonación Molecular , Transporte de Electrón , Sustancias Macromoleculares , Datos de Secuencia Molecular , Estructura Molecular , Mutación , Fotosíntesis , Proteínas del Complejo del Centro de Reacción Fotosintética , Conformación Proteica , Rhodopseudomonas/análisis , Rhodopseudomonas/genética , Rhodopseudomonas/crecimiento & desarrollo , Espectrofotometría
10.
Clin Neuroradiol ; 27(1): 81-89, 2017 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-26227619

RESUMEN

Diffusion tensor imaging (DTI) and tractography provide the neurosurgeon with a valid 3D view of the white matter tracts of the brain for the presurgical planning of the treatment of lesions close to eloquent areas, this being one of the principal clinical applications of this technique. In this article, we describe through practical cases the anatomic relationships of white matter tracts that are essential for language and reading, based on DTI studies and the excellent anatomic correlation with the intraoperative subcortical map.


Asunto(s)
Encéfalo/anatomía & histología , Imagen de Difusión Tensora/métodos , Lenguaje , Red Nerviosa/anatomía & histología , Lectura , Sustancia Blanca/anatomía & histología , Estimulación Encefálica Profunda/métodos , Humanos , Imagenología Tridimensional/métodos , Monitorización Neurofisiológica Intraoperatoria/métodos , Vías Nerviosas/anatomía & histología
11.
Oncogene ; 16(9): 1113-23, 1998 Mar 05.
Artículo en Inglés | MEDLINE | ID: mdl-9528853

RESUMEN

The occurrence of DNA double strand breaks induces cell cycle arrest in mortal and immortal human cells. In normal, mortal fibroblasts this block to proliferation is permanent. It depends on the growth regulator p53 and a protein p53 induces, the cyclin dependent kinase inhibitor, p21. We show here that following DNA damage in mortal fibroblasts, the induction of p21 and p53 is to a large degree shortlived. By 8 days after a brief exposure to DNA strand breaking agents, bleomycin or actinomycin D, p53 protein is at baseline levels, while the p53 transactivation level is only slightly above its baseline. By this time the concentration of p21 protein, which goes up as high as 100-fold shortly after treatment, is down to just 2-4-fold over baseline levels. Following the drop in p21 concentration a large increase in the expression level of the tumor suppressor gene p16INK4a is observed. This scenario, where a transient increase in p21 is followed by a delayed induction of p16INK4a, also happens with the permanent arrest that occurs with cellular senescence. In fact, these cells treated with agents that cause DNA double strand breaks share a number of additional markers with senescent cells. Our findings indicate that these cells are very similar to senescent cells and that they have additional factor(s) beside p21 and p53 that maintain cell cycle arrest.


Asunto(s)
Proteínas de Ciclo Celular/biosíntesis , Senescencia Celular , Inhibidor p16 de la Quinasa Dependiente de Ciclina/biosíntesis , Daño del ADN , Dactinomicina/toxicidad , Secuencia de Bases , Sitios de Unión , Ciclo Celular/efectos de los fármacos , Línea Celular , Fibroblastos/citología , Fibroblastos/efectos de los fármacos , Fibroblastos/fisiología , Humanos , Pulmón , Masculino , Activación Transcripcional , Proteína p53 Supresora de Tumor/metabolismo
12.
J Mol Biol ; 232(1): 242-52, 1993 Jul 05.
Artículo en Inglés | MEDLINE | ID: mdl-8331661

RESUMEN

Combinatorial cassette mutagenesis was used to substitute randomly nine amino acid residues in the vicinity of the active branch monomeric bacteriochlorophyll in the photosynthetic reaction center of Rhodobacter capsulatus. The bacteriochlorophyll environment was targeted because of the potential role of this cofactor in the initial charge separation event of photosynthesis. Mutants with perturbed binding and which have altered energy levels of this chromophore, would be useful for electron transfer studies. Four sites in the M-subunit D-helix and five sites in the L-subunit cd-helix, including residue L153, the axial histidine ligand to the bacteriochlorophyll, were randomly substituted. The cd and D-helix regions were mutagenized independently of each other and simultaneously, resulting in three libraries of mutants. Digital imaging spectroscopy was used to screen photosynthetically selected mutants for ground state absorption spectra in the visible and near-infrared. The functional mutants of each library have distinct spectroscopic characteristics. One unusual spectral phenotype with an absorbance band at 825 nm occurred only in the nine-site library, with a frequency of about one out of 10(6) mutants. A mutant with an 825 nm band also has an unusual light-minus-dark difference spectra, which does not show a blue shift of the 800 nm absorption band. The mean molar volume and hydropathy of the substitutions occurring in functional mutants are biased towards the mean values of a random dope to various extents, indicating different stringencies at each site for these physicochemical properties.


Asunto(s)
Bacterioclorofilas/química , Fotosíntesis , Proteínas del Complejo del Centro de Reacción Fotosintética/química , Secuencia de Aminoácidos , Simulación por Computador , Análisis Mutacional de ADN , Ligandos , Complejos de Proteína Captadores de Luz , Proteínas Recombinantes , Rhodobacter/metabolismo , Solubilidad , Relación Estructura-Actividad
13.
Int J Gynaecol Obstet ; 89 Suppl 2: S4-S12, 2005 May.
Artículo en Inglés | MEDLINE | ID: mdl-15823266

RESUMEN

The objective of cervical cancer screening is to reduce cervical cancer incidence and mortality by detecting and treating precancerous lesions. Conventional cytology is the most widely used cervical cancer screening test. Although cytology has been effective in reducing the incidence of and mortality from cervical cancer in developed countries in both opportunistic and--more dramatically--organized national programs, it has been less successful and largely ineffective in reducing disease burden in low-resource settings where it has been implemented. Liquid-based cytology, testing for infection with oncogenic types of human papillomaviruses, visual inspection with 3-5% acetic acid, magnified visual inspection with acetic acid, and visual inspection with Lugol's iodine have been evaluated as alternative tests. Their test characteristics, and the applications and limitations in screening, are discussed with an emphasis on the work of the Alliance for Cervical Cancer Prevention over the past 5 years.


Asunto(s)
Tamizaje Masivo/métodos , Lesiones Precancerosas/diagnóstico , Lesiones Precancerosas/terapia , Neoplasias del Cuello Uterino/diagnóstico , Neoplasias del Cuello Uterino/prevención & control , Técnicas Citológicas , Sondas de ADN de HPV , Países en Desarrollo , Femenino , Humanos , Incidencia , Lesiones Precancerosas/mortalidad , Neoplasias del Cuello Uterino/mortalidad , Frotis Vaginal
14.
Neurocirugia (Astur) ; 16(4): 365-8, 2005 Aug.
Artículo en Español | MEDLINE | ID: mdl-16143810

RESUMEN

Aneurysmal bone cyst is an uncommon lesion that occurs mainly in long bones and vertebrae, being the location in the sphenoid sinus extremely rare. Its origin is unknown, but it can be considered as a vascular phenomenon secondary to a primary lesion. Other primary diseases that may be associated to aneurysmal bone cyst are polyostotic fibrous dysplasia and giant-cell tumors. We report the case of a patient with an aneurysmal bone cyst in the sphenoid sinus causing vision dysfunction.


Asunto(s)
Quistes Óseos Aneurismáticos/patología , Enfermedades de los Senos Paranasales/patología , Seno Esfenoidal/patología , Adulto , Quistes Óseos Aneurismáticos/cirugía , Femenino , Humanos , Imagen por Resonancia Magnética , Enfermedades de los Senos Paranasales/cirugía , Seno Esfenoidal/cirugía
15.
Int J Biochem Cell Biol ; 33(5): 499-506, 2001 May.
Artículo en Inglés | MEDLINE | ID: mdl-11331205

RESUMEN

A growing body of evidence has demonstrated that reperfusion injury may be mediated, in part, by mitochondrial Ca2+ overload that promotes non-selective permeability of the inner membrane. In this regard it is known that mitochondria from hypothyroid rats are resistant to membrane damage as induced by Ca2+. The purpose of this study was to evaluate the sensitivity of hearts from hypothyroid rats, to the damage by reperfusion, after an ischemic period of 5 min. The results were compared with those from control and hyperthyroid rats. Hypothyroidism was established by surgical removal of the thyroid gland; in turn hyperthyroidism was induced after a daily injection of 2 mg/kg of 3,5,3'-triiodothyronine for 4 days. ECG tracings from hypothyroid rats showed a total absence of post-reperfusion arrhythmias conversely to what was observed in control and hyperthyroid rats. The release of creatine kinase and aspartate amino transferase to the plasma in hypothyroid rats was found to be lower than that found in hyperthyroid and euthyroid rats. The histological studies showed that myocardial fibers from hypothyroid rats were in good condition and retained their striae and a remarkable near absence of edema was clearly observed.


Asunto(s)
Hipertiroidismo/metabolismo , Hipotiroidismo/metabolismo , Daño por Reperfusión Miocárdica/fisiopatología , Miocardio/metabolismo , Animales , Aspartato Aminotransferasas/sangre , Autorradiografía , Presión Sanguínea , Calcio/metabolismo , Creatina Quinasa/sangre , Electrocardiografía , Masculino , Miocardio/química , Miocardio/citología , Ratas , Ratas Wistar , Tiroidectomía
16.
Biochem Pharmacol ; 58(4): 675-85, 1999 Aug 15.
Artículo en Inglés | MEDLINE | ID: mdl-10413306

RESUMEN

Damage to DNA has been implicated in the induction of permanent cell cycle arrest or premature senescence in normal human fibroblasts. We tested the ability of a group of cancer chemotherapeutic agents or related compounds, which can cause DNA double-strand breaks (DSBs) directly or indirectly, to induce a permanent cell cycle arrest in normal proliferating fibroblasts. A brief treatment with etoposide, doxorubicin, cisplatin, or phleomycin D1 induced a block to S phase entry sustained through 15 days. Lower levels of these drugs did not induce appreciable levels of transient cell cycle arrest. Higher concentrations caused cell death that lacked the DNA degradation characteristic of apoptosis. Camptothecin, an agent that causes DNA single-strand breaks, which are converted to DSBs during S phase, was able to induce an efficient, but only transient, cell cycle arrest in these normal cells. The cells did not enter S phase until after removal of the camptothecin. These findings support the idea that permanent cell cycle arrest and cell death are typical reactions of these normal cells to drugs that can cause DSBs. In addition, we report data consistent with the concept that both actinomycin D and doxorubicin are sequestered by cells and slowly released in active form. This is consistent with the observation that both these drugs bind reversibly to intracellular components.


Asunto(s)
Antineoplásicos/farmacología , Camptotecina/farmacología , Ciclo Celular/efectos de los fármacos , Doxorrubicina/farmacología , Etopósido/farmacología , Fibroblastos/efectos de los fármacos , División Celular/efectos de los fármacos , Supervivencia Celular/efectos de los fármacos , Células Cultivadas , Inhibidor p21 de las Quinasas Dependientes de la Ciclina , Ciclinas/biosíntesis , Daño del ADN , Dactinomicina/farmacología , Doxorrubicina/metabolismo , Fibroblastos/citología , Humanos , Proteína p53 Supresora de Tumor/biosíntesis
17.
J Clin Epidemiol ; 41(5): 495-501, 1988.
Artículo en Inglés | MEDLINE | ID: mdl-3367181

RESUMEN

Completeness of cancer registration has not been consistently ascertained across different registries. This report describes how capture-recapture methods have been used to estimate completeness at the Ontario Cancer Registry. The method was applied in two fashions; first, using three data sources in a modeling approach: and second, using two data sources and standard, simple capture-recapture methods. The modeling approach is more flexible, since several variables that influence cancer registration can be considered and can be used to identify reporting patterns of different data sources. In the present analysis, estimates of completeness of the registry as a whole were remarkably similar using either two or three data sources, and site-specific comparisons differed by at most 7%. Because of the advantages of capture-recapture methods-estimation of level of completeness, possible comparability of estimates across different registries, and versatility to consider other determinants of cancer registration-a plea for greater use of these methods in cancer registration is made.


Asunto(s)
Neoplasias/epidemiología , Sistema de Registros , Recolección de Datos/métodos , Certificado de Defunción , Humanos , Modelos Teóricos , Ontario , Alta del Paciente , Proyectos de Investigación
18.
DNA Cell Biol ; 17(1): 9-18, 1998 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-9468218

RESUMEN

P21 is a regulatory protein that can contribute to cell cycle arrest by inhibiting the cyclin-dependent-kinases (cdks). However, the mechanism that links the inhibition of the cdk activities and the cell cycle arrest is not well established. To investigate this, we studied a purified endogenous cellular complex which contained E2F (in the form of E2F-4), p130, cyclin, and cdk2. This complex of E2F-p130-cyclin-cdk2 is found mainly in cycling cells and is postulated to be an intermediate that leads to the activation of E2F. We previously showed that p21 could disrupt this complex leading to the accumulation of an E2F-p130 complex and the inhibition of E2F-regulated transcription. We analyzed a group of p21 mutants including those that harbored changes in cyclin- and cdk2-binding motifs. We show that both the cyclin and cdk2 binding motifs of p21 are crucial for the disruption of this endogenous complex of E2F-p130-cyclin-cdk2. This suggests a model where the ability of p21 to inhibit the function of this complex is dependent on interactions with both cyclin and cdk2 molecules. This was substantiated by studies with intact cells. P21 mutants that are impaired in their ability to disrupt the cellular E2F-p130-cyclin-cdk2 complex are also shown to be maximally impaired in the ability to repress E2F-regulated transcription.


Asunto(s)
Quinasas CDC2-CDC28 , Proteínas Portadoras , Proteínas de Ciclo Celular , Ciclo Celular , Quinasas Ciclina-Dependientes/fisiología , Ciclinas/fisiología , Proteínas de Unión al ADN , Fosfoproteínas/fisiología , Proteínas Serina-Treonina Quinasas/fisiología , Proteínas , Factores de Transcripción/fisiología , Células 3T3 , Adenosina Trifosfato/metabolismo , Animales , Sitios de Unión , Ciclina A/metabolismo , Ciclina E/metabolismo , Quinasa 2 Dependiente de la Ciclina , Inhibidor p21 de las Quinasas Dependientes de la Ciclina , Factores de Transcripción E2F , Factor de Transcripción E2F4 , Ratones , Mutagénesis Sitio-Dirigida , Unión Proteica , Proteína 1 de Unión a Retinoblastoma , Proteína p130 Similar a la del Retinoblastoma , Fase S , Transducción de Señal , Relación Estructura-Actividad , Factor de Transcripción DP1 , Transcripción Genética
19.
Spine (Phila Pa 1976) ; 25(18): 2333-41, 2000 Sep 15.
Artículo en Inglés | MEDLINE | ID: mdl-10984785

RESUMEN

STUDY DESIGN: Retrospective review of long instrumented fusions down to the low lumbar spine for the treatment of adolescent idiopathic scoliosis. OBJECTIVES: To evaluate whether the use of instrumentation systems that preserve the sagittal profile could reduce the incidence of early degenerative changes. SUMMARY OF BACKGROUND DATA: Long fusions and distractive Harrington instrumentation in the surgical treatment of adolescent idiopathic scoliosis (AIS) are known to produce pain and degenerative changes in the free lumbar segments. Reports on the use of Cotrel-Dubousett instrumentation (CDI) confirm that the instrumentation maintains physiologic lumbar lordosis, but the evolution of the spine below the fusion is not addressed. METHOD: Thirty-five patients with AIS and CDI were studied. Their spines were fused to L3 or lower, and they had a minimum follow-up of 10 years. Radiologic measurements were recorded from frontal and lateral radiographs. At the time of last examination, lateral flexion-extension dynamic radiographs and magnetic resonance imaging evaluated the health of the disks below the fusion. Clinical outcome was assessed with the Scoliosis Research Society instrument. A control group consisting of 35 peers without scoliosis served as a reference for the outcome questionnaire. RESULTS: Surgery kept the sagittal profile in a physiologic range. All but two patients were satisfied with the results of surgery. There were no differences between patients and control group insofar as pain, self-image, general function, and daily activity were concerned. Eleven patients showed instability signs in dynamic radiographs and more than half of patients showed incipient degeneration on magnetic resonance images. These findings are similar to those found in the general population, according to the literature, and could evidence normal aging processes. CONCLUSIONS: Cotrel-Dubousset instrumentation maintains the physiologic sagittal contour. Although there are some degenerative changes in magnetic resonance images and dynamic radiographs, the quality of life and daily activities of the patients after surgery are similar to those of a normal population of the same age.


Asunto(s)
Escoliosis/cirugía , Fusión Vertebral/métodos , Adolescente , Adulto , Niño , Femenino , Humanos , Vértebras Lumbares/diagnóstico por imagen , Vértebras Lumbares/fisiopatología , Vértebras Lumbares/cirugía , Imagen por Resonancia Magnética , Masculino , Radiografía , Estudios Retrospectivos , Escoliosis/diagnóstico por imagen , Escoliosis/psicología , Fusión Vertebral/psicología , Estadísticas no Paramétricas , Encuestas y Cuestionarios , Resultado del Tratamiento
20.
Biotechnology (N Y) ; 8(8): 746-9, 1990 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-1366901

RESUMEN

Digital imaging spectroscopy has been used to obtain the grayscale spectrum of colored bacterial colonies directly from petri dishes. Up to 500 individual colony spectra can be simultaneously recorded and processed from a single plate. Spectra can be obtained in the visible to near infrared region (400nm-900nm) with 10nm resolution. Instrument response is normalized through run-time radiometric calibration such that each grayscale spectrum can be converted to the ground-state absorption spectrum of the colony. In this study, mutants of the photosynthetic bacterium Rhodobacter capsulatus have been differentiated by the absorption spectra of their pigment-protein complexes. This imaging technique is applicable to chromogenic systems in which colony and/or media color (e.g. indicator plates) provides a quantitative indicator of gene expression.


Asunto(s)
Recuento de Colonia Microbiana/métodos , Procesamiento de Imagen Asistido por Computador , Análisis Espectral/instrumentación , Secuencia de Aminoácidos , Luz , Datos de Secuencia Molecular , Fenotipo , Rhodobacter capsulatus/genética , Dispersión de Radiación , Espectrofotometría Infrarroja/instrumentación
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