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1.
J Environ Manage ; 150: 367-377, 2015 Mar 01.
Artículo en Inglés | MEDLINE | ID: mdl-25560653

RESUMEN

In pest risk assessment it is frequently necessary to make time-critical decisions regarding management of expanding pest populations. When an invasive pest outbreak is expanding rapidly, preemptive quarantine of areas that are under imminent threat of infestation is one of only a few available management tools that can be implemented quickly to help control the expansion. The preemptive quarantine of locations that surround an infested area also acts as a safeguard to counteract the risk of failed detections of the pest in field surveys. In this paper, we present a method that assesses the suitability of preemptive quarantine measures at the level of small geographical subdivisions (U.S. counties). The cost of a preemptive quarantine in a given county is weighed against the protective benefit of delaying the spread of an outbreak to other neighboring counties. We demonstrate the approach with a decision support model that estimates the suitability of preemptive quarantine across multiple counties that surround areas infested with the emerald ash borer (Agrilus planipennis Fairmaire (EAB), Coleoptera: Buprestidae), an emerging major threat to ash tree species (Fraxinus spp.) in North America. The model identifies the U.S. counties where the installation of preemptive quarantine would most effectively slow the spread of EAB populations and reduce risk to high-value areas.


Asunto(s)
Escarabajos , Fraxinus , Modelos Teóricos , Cuarentena/economía , Animales , Brotes de Enfermedades/prevención & control , Sistemas de Información Geográfica , Great Lakes Region , Humanos , Control de Insectos , Cuarentena/métodos , Estados Unidos
2.
Eur Cell Mater ; 28: 166-207; discussion 207-8, 2014 Oct 06.
Artículo en Inglés | MEDLINE | ID: mdl-25284140

RESUMEN

There is a growing socio-economic need for effective strategies to repair damaged bone resulting from disease, trauma and surgical intervention. Bone tissue engineering has received substantial investment over the last few decades as a result. A multitude of studies have sought to examine the efficacy of multiple growth factors, delivery systems and biomaterials within in vivo animal models for the repair of critical-sized bone defects. Defect repair requires recapitulation of in vivo signalling cascades, including osteogenesis, chondrogenesis and angiogenesis, in an orchestrated spatiotemporal manner. Strategies to drive parallel, synergistic and consecutive signalling of factors including BMP-2, BMP-7/OP-1, FGF, PDGF, PTH, PTHrP, TGF-ß3, VEGF and Wnts have demonstrated improved bone healing within animal models. Enhanced bone repair has also been demonstrated in the clinic following European Medicines Agency and Food and Drug Administration approval of BMP-2, BMP-7/OP-1, PDGF, PTH and PTHrP. The current review assesses the in vivo and clinical data surrounding the application of growth factors for bone regeneration. This review has examined data published between 1965 and 2013. All bone tissue engineering studies investigating in vivo response of the growth factors listed above, or combinations thereof, utilising animal models or human trials were included. All studies were compiled from PubMed-NCBI using search terms including 'growth factor name', 'in vivo', 'model/animal', 'human', and 'bone tissue engineering'. Focus is drawn to the in vivo success of osteoinductive growth factors incorporated within material implants both in animals and humans, and identifies the unmet challenges within the skeletal regenerative area.


Asunto(s)
Regeneración Ósea , Factores de Diferenciación de Crecimiento/metabolismo , Ingeniería de Tejidos/métodos , Animales , Ensayos Clínicos como Asunto , Factores de Diferenciación de Crecimiento/genética , Humanos , Andamios del Tejido
3.
Eur J Cancer Care (Engl) ; 23(3): 340-8, 2014 May.
Artículo en Inglés | MEDLINE | ID: mdl-24299170

RESUMEN

While advanced cancer is often associated with weight loss, curative cancer treatment is often associated with weight gain. Weight gain during treatment may be associated with greater risk of cancer recurrence and development of lifestyle diseases. Currently, limited resources are available to cancer patients focussed on weight control. This study assessed the information needs of patients undergoing curative chemotherapy regarding diet, exercise and weight management for the purpose of developing weight management resources. Focus groups were held with oncology practitioners, patients and survivors to determine current information provision and needs. Focus groups highlighted a perception that information provision regarding diet, exercise and weight management is insufficient and no routine assessment of weight occurs during chemotherapy. Barriers to information provision described included lack of resources and time, and practitioners' uncertainty regarding appropriate messages to provide. Patients wanted more information regarding diet, exercise and weight during treatment time. The findings of this study suggest an increase in provision of diet, exercise and weight management information is needed. This information should be evidence-based and delivered at an appropriate time by the preferred health care professional. It would also be beneficial to implement protocols regarding assessment of weight during treatment.


Asunto(s)
Dieta , Ejercicio Físico , Promoción de la Salud , Evaluación de Necesidades , Neoplasias , Educación del Paciente como Asunto , Anciano , Femenino , Grupos Focales , Humanos , Persona de Mediana Edad , Obesidad , Investigación Cualitativa , Sobrevivientes , Aumento de Peso , Pérdida de Peso
4.
Front Cell Dev Biol ; 12: 1382960, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-38863942

RESUMEN

Introduction: Vertebrate body axis formation initiates during gastrulation and continues within the tail bud at the posterior end of the embryo. Major structures in the trunk are paired somites, which generate the musculoskeletal system, the spinal cord-forming part of the central nervous system, and the notochord, with important patterning functions. The specification of these different cell lineages by key signalling pathways and transcription factors is essential, however, a global map of cell types and expressed genes in the avian trunk is missing. Methods: Here we use high-throughput sequencing approaches to generate a molecular map of the emerging trunk and tailbud in the chick embryo. Results and Discussion: Single cell RNA-sequencing (scRNA-seq) identifies discrete cell lineages including somites, neural tube, neural crest, lateral plate mesoderm, ectoderm, endothelial and blood progenitors. In addition, RNA-seq of sequential tissue sections (RNA-tomography) provides a spatially resolved, genome-wide expression dataset for the avian tailbud and emerging body, comparable to other model systems. Combining the single cell and RNA-tomography datasets, we identify spatially restricted genes, focusing on somites and early myoblasts. Thus, this high-resolution transcriptome map incorporating cell types in the embryonic trunk can expose molecular pathways involved in body axis development.

5.
J Neurophysiol ; 107(4): 1094-110, 2012 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-22114163

RESUMEN

We used dynamic dense noise stimuli and local spectral reverse correlation methods to reveal the local sensitivities of neurons in visual area 2 (V2) of macaque monkeys to orientation and spatial frequency within their receptive fields. This minimized the potentially confounding assumptions that are inherent in stimulus selections. The majority of neurons exhibited a relatively high degree of homogeneity for the preferred orientations and spatial frequencies in the spatial matrix of facilitatory subfields. However, about 20% of all neurons showed maximum orientation differences between neighboring subfields that were greater than 25 deg. The neurons preferring horizontal or vertical orientations showed less inhomogeneity in space than the neurons preferring oblique orientations. Over 50% of all units also exhibited suppressive profiles, and those were more heterogeneous than facilitatory profiles. The preferred orientation and spatial frequency of suppressive profiles differed substantially from those of facilitatory profiles, and the neurons with suppressive subfields had greater orientation selectivity than those without suppressive subfields. The peak suppression occurred with longer delays than the peak facilitation. These results suggest that the receptive field profiles of the majority of V2 neurons reflect the orderly convergence of V1 inputs over space, but that a subset of V2 neurons exhibit more complex response profiles having both suppressive and facilitatory subfields. These V2 neurons with heterogeneous subfield profiles could play an important role in the initial processing of complex stimulus features.


Asunto(s)
Orientación/fisiología , Células Receptoras Sensoriales/fisiología , Percepción Espacial/fisiología , Corteza Visual/citología , Campos Visuales/fisiología , Potenciales de Acción/fisiología , Animales , Anisotropía , Mapeo Encefálico , Macaca mulatta/fisiología , Dinámicas no Lineales , Estimulación Luminosa/métodos , Psicofísica , Tiempo de Reacción , Filtrado Sensorial/fisiología , Análisis Espectral , Estadística como Asunto , Corteza Visual/fisiología
6.
Cereb Cortex ; 21(9): 2033-45, 2011 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-21263036

RESUMEN

Amblyopia, a developmental disorder of spatial vision, is thought to result from a cascade of cortical deficits over several processing stages beginning at the primary visual cortex (V1). However, beyond V1, little is known about how cortical development limits the visual performance of amblyopic primates. We quantitatively analyzed the monocular and binocular responses of V1 and V2 neurons in a group of strabismic monkeys exhibiting varying depths of amblyopia. Unlike in V1, the relative effectiveness of the affected eye to drive V2 neurons was drastically reduced in the amblyopic monkeys. The spatial resolution and the orientation bias of V2, but not V1, neurons were subnormal for the affected eyes. Binocular suppression was robust in both cortical areas, and the magnitude of suppression in individual monkeys was correlated with the depth of their amblyopia. These results suggest that the reduced functional connections beyond V1 and the subnormal spatial filter properties of V2 neurons might have substantially limited the sensitivity of the amblyopic eyes and that interocular suppression was likely to have played a key role in the observed alterations of V2 responses and the emergence of amblyopia.


Asunto(s)
Ambliopía/fisiopatología , Estrabismo/fisiopatología , Corteza Visual/fisiopatología , Edad de Inicio , Algoritmos , Animales , Sensibilidad de Contraste/fisiología , Interpretación Estadística de Datos , Predominio Ocular/fisiología , Macaca mulatta , Microelectrodos , Neuronas/fisiología , Distribución Normal , Orientación/fisiología , Estimulación Luminosa , Errores de Refracción/fisiopatología , Visión Binocular/fisiología , Corteza Visual/citología , Campos Visuales/fisiología
7.
Eur Cell Mater ; 21: 193-201, 2011 Feb 24.
Artículo en Inglés | MEDLINE | ID: mdl-21351053

RESUMEN

Growth factors are known to be sequestered to the mineralised matrix of bone. The aim of this study was to investigate the ability of citric acid, EDTA, calcium hydroxide and sodium hydroxide to release active growth factors from bone surfaces, able to promote osteoblast differentiation. All chemical treatments increased surface levels of TGF-beta1 (used as a biomarker of growth factor release), compared to control bone surfaces treated with PBS. Differences were observed in the kinetics of TGF-beta1 exposure at the surface and its subsequent release into the aqueous environment for the different chemical treatments. Surface levels of growth factor following chemical treatment were low, but of sufficient concentration to stimulate cell expansion and osteoblast differentiation of bone marrow stromal cells grown on EDTA and calcium hydroxide treated surfaces compared to PBS treated surfaces. The increased osteogenic potential on these surfaces may relate to an increase in growth factor availability and changes to the surface chemistry and topography.


Asunto(s)
Huesos/efectos de los fármacos , Factor de Crecimiento Transformador beta1/farmacología , Animales , Huesos/citología , Huesos/ultraestructura , Adhesión Celular/efectos de los fármacos , Proliferación Celular/efectos de los fármacos , Forma de la Célula/efectos de los fármacos , Células Cultivadas , Fluoresceína-5-Isotiocianato/metabolismo , Inmunohistoquímica , Masculino , Faloidina/metabolismo , Ratas , Ratas Wistar , Propiedades de Superficie/efectos de los fármacos
8.
Nat Med ; 1(8): 761-5, 1995 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-7585177

RESUMEN

The influence of visual experience on ocular development in higher primates is not well understood. To investigate the possible role of defocus in regulating ocular growth, spectacle lenses were used to optically simulate refractive anomalies in young monkeys (for example, myopia or nearsightedness). Both positive and negative lenses produced compensating ocular growth that reduced the lens-induced refractive errors and, at least for low lens powers, minimized any refractive-error differences between the two eyes. These results indicate that the developing primate visual system can detect the presence of refractive anomalies and alter each eye's growth to eliminate these refractive errors. Moreover, these results support the hypothesis that spectacle lenses can alter eye development in young children.


Asunto(s)
Acomodación Ocular , Ojo/crecimiento & desarrollo , Anteojos , Errores de Refracción/etiología , Visión Ocular/fisiología , Animales , Animales Recién Nacidos , Ojo/anatomía & histología , Retroalimentación , Fijación Ocular , Macaca mulatta , Oftalmoscopía , Disparidad Visual
9.
J Environ Qual ; 40(4): 1257-65, 2011.
Artículo en Inglés | MEDLINE | ID: mdl-21712595

RESUMEN

Artificially draining soils using subsurface tiles is a common practice on many agricultural fields. High levels of nitrate-nitrogen (NO-N) are often released from these systems; therefore, knowledge on the sources and processes controlling NO-N in drainage systems is needed. A dual isotope study (δN and δO) was used to investigate three subsurface drainage systems (shallow, conventional, and controlled) in Onslow, Nova Scotia, Canada. The objectives of this study were (i) to identify which drainage system more effectively reduced the NO-N loading, (ii) to examine differences in isotopic signatures under identical nutrient and cropping regimes for a fixed soil type, and (iii) to identify the utility of different drainage systems in controlling nutrient flows. Nitrate concentrations measured ranged from 0.92 to 11.8, from 2.3 to 17.3, and from 2.1 to 19.8 mg L for the shallow, conventional, and controlled drains, respectively. Total NO-N loading from shallow and controlled drains were 20 and 5.6 kg ha, respectively, lower than conventional (39.1 kg ha). The isotopic composition of NO-N for all drainage types appeared to be a mixture of two organic sources (manure and soil organic matter) via the process of nitrification. There was no evidence that denitrification played a significant role in removing NO-N during transport. Overall, shallow drainage reduced NO-N loading but offered no water conservation benefits. Combining the benefits of decreased NO-N loading from shallow systems with water control capability may offer the best solution to reducing nutrient loadings into water systems, achieving optimal crop yield, and decreasing drainage installation costs.


Asunto(s)
Agricultura , Restauración y Remediación Ambiental/métodos , Nitratos/análisis , Isótopos de Nitrógeno/química , Isótopos de Oxígeno/química , Movimientos del Agua , Desnitrificación , Restauración y Remediación Ambiental/economía , Nitrificación , Nueva Escocia , Suelo/química , Zea mays/crecimiento & desarrollo
10.
J Environ Manage ; 92(11): 2892-9, 2011 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-21816538

RESUMEN

Intensive agricultural farming practices have the potential to cause high levels of nitrate-nitrogen (NO(3)(-)-N) to be released from tile drainage systems. A better understanding of the temporal dynamics of NO(3)(-)-N loading, δ(15)N and δ(18)O from standard drainage systems is needed, in order to improve our understanding of NO(3)(-)-N transport and transformation processes; particularly, with regards to the imperfectly drained agricultural soils found within Atlantic Canada. Three conventional subsurface drainage plots (48 × 48 m) placed at a 0.80 m soil depth were monitored over a seven month period on sandy loam soil in Onslow, Nova Scotia. Each plot received similar applications of both organic and inorganic fertilizer. Water samples were obtained and analyzed for NO(3)(-)-N concentrations and isotopic signatures of δ(15)N and δ(18)O for NO(3)(-)-N. Maximum NO(3)(-)-N loads were observed in the winter and fall, when both discharge and concentration of the NO(3)(-)-N were highest. Mean isotope values in NO(3)(-) ranged from 3.1 to 8.5‰ for δ(15)N and -3.2 to 17.7‰ for δ(18)O. Results suggest that NO(3)(-)-N from the drainage water was derived from organic sources (i.e. manure and soil organic matter) and that loss via denitrification does not impart an identifiable signature upon the NO(3)(-)-N pool. The dual isotope approach examined here provides insight into N source and transformation processes which may be contributing to the NO(3)(-)-N found within the drainage water.


Asunto(s)
Agricultura , Nitratos/análisis , Contaminantes Químicos del Agua/análisis , Fertilizantes , Isótopos de Nitrógeno/análisis , Nueva Escocia , Isótopos de Oxígeno/análisis , Lluvia , Estaciones del Año , Movimientos del Agua
11.
Science ; 205(4405): 511-3, 1979 Aug 03.
Artículo en Inglés | MEDLINE | ID: mdl-109923

RESUMEN

The contrast sensitivity of the rhesus monkey was tested, according to a modified reaction-time paradigm, for sine-wave grating targets at different orientations. The monkey possesses an oblique effect slightly larger than that of humans. A reaction time analysis showed the oblique effect to be a suprathreshold as well as a threshold phenomenon. The presence of this effect further strengthens the use of the monkey as a model for the human visual system.


Asunto(s)
Percepción Visual , Animales , Conducta Animal , Haplorrinos , Humanos , Macaca mulatta , Especificidad de la Especie
12.
Science ; 206(4420): 852-4, 1979 Nov 16.
Artículo en Inglés | MEDLINE | ID: mdl-493988

RESUMEN

A suprathreshold grating presented to one eye elevated the threshold for the discrimination of gratings similar in size and orientation presented to the fellow eye. The magnitude and stimulus specificity of these binocular interactions in human observers with normal bioncular vision were similar to those in observers deprived of normal binocular visual experience; however, the latter showed a failure of binocular summation at threshold or subthreshold contract levels. Whereas strabismus or amblyopia disrupted the normal excitatory interactions between the two eyes, cortical inhibitory binocular connections seem not to have been disrupted.


Asunto(s)
Ambliopía/fisiopatología , Estrabismo/fisiopatología , Visión Ocular , Percepción Visual/fisiología , Humanos , Orientación/fisiología , Percepción del Tamaño/fisiología , Vías Visuales/fisiología , Vías Visuales/fisiopatología
13.
Science ; 218(4574): 802-4, 1982 Nov 19.
Artículo en Inglés | MEDLINE | ID: mdl-7134975

RESUMEN

Increment-threshold spectral sensitivity functions were determined during the dominance and suppression phases of binocular rivalry. The shapes of the functions obtained during the dominance phase exhibited three maxima at approximately 440, 530, and 610 nanometers and resembled functions obtained for nonrivalrous control conditions. However, the functions measured during suppression had a single broad peak near 555 nanometers and were adequately described by functions measured with flicker methods during nonrivalrous conditions. The results indicate that binocular rivalry differentially attenuates opponent-color information relative to achromatic information.


Asunto(s)
Percepción de Color , Visión Ocular , Lateralidad Funcional , Humanos , Fenómenos Fisiológicos Oculares , Umbral Sensorial
14.
Science ; 204(4395): 875-7, 1979 May 25.
Artículo en Inglés | MEDLINE | ID: mdl-441743

RESUMEN

The effects of conflicting visual images were studied without the confounding influences of oculomotor abnormalities: strabismus was simulated by rearing kittens with ophthalmic prisms before the eyes. After the animals had matured, the response properties of neurons in the visual cortex were studied. The proportion of binocularly excited neurons decreased; however, the extent of the ocular dominance alterations was related to the amount and direction of the prism-induced deviation.


Asunto(s)
Movimientos Oculares , Estrabismo/fisiopatología , Corteza Visual/fisiopatología , Vías Visuales/fisiología , Potenciales de Acción , Lateralidad Funcional , Corteza Visual/citología
15.
Science ; 232(4747): 235-8, 1986 Apr 11.
Artículo en Inglés | MEDLINE | ID: mdl-3952507

RESUMEN

Early in life, abnormal visual experience may disrupt the developmental processes required for the maturation and maintenance of normal visual function. The effects of retinal image deprivation (monocular form deprivation) on four psychophysical functions were investigated in rhesus monkeys to determine if the sensitive period is of the same duration for all types of visual information processing. The basic spectral sensitivity functions of rods and cones have relatively short sensitive periods of development (3 and 6 months) when compared to more complex functions such as monocular spatial vision or resolution (25 months) and binocular vision (greater than 25 months). Therefore, there are multiple, partially overlapping sensitive periods of development and the sensitive period for each specific visual function is probably different.


Asunto(s)
Visión Ocular/fisiología , Percepción Visual/fisiología , Factores de Edad , Animales , Humanos , Macaca mulatta/crecimiento & desarrollo , Células Fotorreceptoras/crecimiento & desarrollo , Privación Sensorial/fisiología , Percepción Espacial/fisiología
16.
Science ; 224(4648): 492-4, 1984 May 04.
Artículo en Inglés | MEDLINE | ID: mdl-17753774

RESUMEN

A new fossil site near Gilboa, New York, is one of only three where fossils of terrestrial arthropods of Devonian age have been found. The new Gilboan fauna is younger than the other two but richer in taxa. Fragmentary remains and nearly whole specimens assigned to Eurypterida, Arachnida (Trigonotarbida, Araneae, Amblypygi, and Acari), Chilopoda [Craterostigmatomorpha(?) and Scuterigeromorpha(?)], and tentatively to Insecta (Archaeognatha) have been found. The centipedes and possible insects may represent the earliest records known for these groups.

17.
J Leukoc Biol ; 82(5): 1147-55, 2007 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-17675558

RESUMEN

Honey is used as a therapy to aid wound healing. Previous data indicate that honey can stimulate cytokine production from human monocytes. The present study further examines this phenomenon in manuka honey. As inflammatory cytokine production in innate immune cells is classically mediated by pattern recognition receptors in response to microorganisms, bacterial contamination of honey and the effect of blocking TLR2 and -4 on stimulatory activity were assessed. No vegetative bacteria were isolated from honey; however, bacterial spores were cultured from one-third of samples, and low levels of LPS were detected. Blocking TLR4 but not TLR2 inhibited honey-stimulated cytokine production significantly. Cytokine production did not correlate with LPS levels in honey and was not inhibited by polymyxin B. Further, the activity was reduced significantly following heat treatment, indicating that component(s) other than LPS are responsible for the stimulatory activity of manuka honey. To identify the component responsible for inducing cytokine production, honey was separated by molecular weight using microcon centrifugal filtration and fractions assessed for stimulatory activity. The active fraction was analyzed by MALDI-TOF mass spectroscopy, which demonstrated the presence of a number of components of varying molecular weights. Additional fractionation using miniaturized, reverse-phase solid-phase extraction resulted in the isolation of a 5.8-kDa component, which stimulated production of TNF-alpha via TLR4. These findings reveal mechanisms and components involved in honey stimulation of cytokine induction and could potentially lead to the development of novel therapeutics to improve wound healing for patients with acute and chronic wounds.


Asunto(s)
Miel , Leptospermum , Monocitos/metabolismo , Receptor Toll-Like 4/metabolismo , Animales , Médula Ósea/metabolismo , Humanos , Interleucina-1/metabolismo , Interleucina-6/metabolismo , Lipopolisacáridos/metabolismo , Ratones , Ratones Endogámicos C57BL , Peso Molecular , Monocitos/citología , Monocitos/inmunología , Polimixina B/farmacología , Espectrometría de Masa por Láser de Matriz Asistida de Ionización Desorción , Staphylococcus aureus/efectos de los fármacos , Staphylococcus aureus/inmunología , Staphylococcus aureus/metabolismo , Receptor Toll-Like 2/antagonistas & inhibidores , Receptor Toll-Like 2/metabolismo , Receptor Toll-Like 4/antagonistas & inhibidores , Factor de Necrosis Tumoral alfa/metabolismo
18.
Mar Environ Res ; 63(5): 457-70, 2007 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-17291579

RESUMEN

Acute sediment toxicity tests do not test key life stage events such as moulting and reproduction and therefore do not reveal the longer-term effects of contaminant exposure. A laboratory method is described for determining the chronic toxicity of contaminants associated with whole sediments. The test is conducted using neonates of the estuarine amphipod Corophium volutator at 15 degrees C, salinity 25 psu and a 12 h light:12 h dark photoperiod. The endpoints are survival and growth after 28 days and survival, growth and reproduction of amphipods upon termination of test i.e. reproduction within all control vessels (ca 75 days). The sediment chronic toxicity test was used to investigate the effects of sediments spiked with environmentally relevant preparations of slightly weathered Alaskan North Slope crude oil, including a water-accommodated-fraction (WAF) and a chemically-dispersed (Corexit 9527) WAF. Sediment oil concentrations were quantified using ultra-violet fluorescence. The amphipods exposed to chemically dispersed oil had higher mortality and lower growth rates than control-, Corexit 9527- and WAF-exposed organisms, resulting in reduced reproduction. The described method supplements the standard acute sediment test and would be particularly useful when long-term ecological effects are suspected but acute tests reveal no significant mortality. The sediment chronic test reported herein has shown that sediment that was not evidently toxic during 10-day acute tests could have population-level effects on sediment-dwelling amphipods.


Asunto(s)
Anfípodos/efectos de los fármacos , Monitoreo del Ambiente/métodos , Contaminantes Ambientales/toxicidad , Sedimentos Geológicos/análisis , Petróleo/toxicidad , Agua de Mar/análisis , Pruebas de Toxicidad Aguda/métodos , Anfípodos/crecimiento & desarrollo , Análisis de Varianza , Animales , Monitoreo del Ambiente/estadística & datos numéricos , Contaminantes Ambientales/análisis , Fluorescencia , Petróleo/análisis , Reproducción/efectos de los fármacos , Rayos Ultravioleta
19.
Cytogenet Genome Res ; 112(1-2): 166-9, 2006.
Artículo en Inglés | MEDLINE | ID: mdl-16276107

RESUMEN

We report a 21-week gestation fetus terminated because of multiple congenital abnormalities seen on ultrasound scan, including ventriculomegaly, possible clefting of the hard palate, cervical hemivertebrae, micrognathia, abnormal heart, horseshoe kidney and a 2-vessel umbilical cord. On cytogenetic examination, the fetus was found to have a male karyotype with 45 chromosomes with a dicentric chromosome, which appeared to consist of the long arms of chromosomes 13 and 17. Molecular genetic investigations and fluorescence in situ hybridization (FISH) unexpectedly showed that the derivative chromosome contained two interstitial blocks of chromosome 17 short arm sequences, totalling approximately 7 Mb, between the two centromeres. This effectively made the fetus monosomic for approximately 15 Mb of 17p without the concurrent trisomy for another chromosome normally seen following malsegregation of reciprocal translocations. It also illustrates the complexity involved in the formation of some structurally abnormal chromosomes, which can only be resolved by detailed molecular investigations.


Asunto(s)
Anomalías Múltiples/embriología , Anomalías Múltiples/genética , Aberraciones Cromosómicas , Cromosomas Humanos Par 13 , Cromosomas Humanos Par 17 , Anomalías Múltiples/diagnóstico por imagen , Aborto Inducido , Adulto , Mapeo Cromosómico , Femenino , Edad Gestacional , Humanos , Hibridación Fluorescente in Situ , Cariotipificación , Masculino , Embarazo , Eliminación de Secuencia , Piel/embriología , Ultrasonografía
20.
Cancer Res ; 52(13): 3615-21, 1992 Jul 01.
Artículo en Inglés | MEDLINE | ID: mdl-1617633

RESUMEN

Several heterocyclic amines, found in cooked food, are powerful mutagens in the Ames Salmonella mutagenicity test system. One of these, 2-amino-3,4-dimethylimidazo[4,5-f]quinoline (MeIQ) is one of the most mutagenic chemicals tested in this assay. In primary cultures of chick and rat hepatocytes, MeIQ, by itself, induced cytochrome P450 from the IA subfamily but was a weak inducer compared to 3-methylcholanthrene. However, in both chick and rat hepatocytes in culture, MeIQ decreased the amount of 3-methylcholanthrene-induced ethoxyresorufin deethylase activity, which is catalyzed by cytochrome P450 IA. The protein moiety of cytochrome P450 IA was decreased at MeIQ concentrations of 2.5 micrograms/ml or greater in chick hepatocytes and 25 micrograms/ml in rat hepatocytes. In hepatic microsomes from methylcholanthrene-treated chicks and rats, MeIQ was a competitive inhibitor of both ethoxyresorufin deethylase activity, a reaction catalyzed mainly by rodent cytochrome P450 IA1, and uroporphyrinogen oxidation, a reaction catalyzed by rodent P450 IA2. In cultured chick hepatocytes, MeIQ also decreased cytochrome P450-mediated oxidation of uroporphyrinogen by intact cells. The ability of MeIQ to inhibit as well as to induce cytochrome P450s of the IA subfamily may be important in assessing the mutagenic and carcinogenic effects of MeIQ in mammals.


Asunto(s)
Sistema Enzimático del Citocromo P-450/análisis , Hígado/efectos de los fármacos , Mutágenos , Quinolinas/toxicidad , Animales , Células Cultivadas , Embrión de Pollo , Citocromo P-450 CYP1A1 , Hígado/enzimología , Masculino , Oxidorreductasas/análisis , Ratas , Ratas Endogámicas F344 , Uroporfirinógenos/metabolismo
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