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1.
Int Endod J ; 52(1): 114-122, 2019 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-30019752

RESUMEN

AIM: To determine the free available chlorine of 2.5% sodium hypochlorite (NaOCl) alone and combined with 9% etidronic acid (HEDP) in the presence of inhibitors, organic tissue and organic tissue plus dentine debris; to evaluate the influence of dentine debris on the tissue-dissolving capacity of both NaOCl solutions; and to determine the antimicrobial action of these solutions when in contact with organic tissue and organic tissue plus dentine debris. METHODOLOGY: The available chlorine of the solutions over time in the absence and presence of the inhibitors was measured using a titration method. The organic tissue dissolution by the solutions alone and in the presence of dentine powder was evaluated by weighing bovine tissue specimens before and after exposure to the solutions for 3 and 10 min. For the antimicrobial activity, biofilms of Enterococcus faecalis were exposed to the solutions for 3 min in the absence and presence of organic tissue and organic tissue + dentine debris. The biovolume and percentage of damaged membrane cells of the biofilm were measured by means of confocal microscopy and the live/dead technique. Nonparametric tests were used to determine statistical differences (P < 0.05). RESULTS: Both inhibitors consumed the free available chlorine of the solutions over time. The presence of dentine debris significantly reduced the tissue dissolution capacity of the NaOCl solutions (P < 0.05). The percentages of biovolume reduction were not affected by the presence of the inhibitors in the two NaOCl solutions, whereas the percentage of damaged membrane cells was significantly reduced (P < 0.001). Overall, a similar behaviour was observed in the NaOCl and NaOCl/HEDP groups. CONCLUSIONS: The presence of organic tissue and organic tissue + dentine debris favoured rapid consumption of the free chlorine of NaOCl and NaOCl/HEDP. This resulted in a decreased ability to dissolve organic tissue without affecting the short-term antimicrobial activity.


Asunto(s)
Antiinfecciosos/farmacología , Dentina/efectos de los fármacos , Ácido Etidrónico/farmacología , Irrigantes del Conducto Radicular/farmacología , Hipoclorito de Sodio/farmacología , Animales , Biopelículas/efectos de los fármacos , Bovinos , Membrana Celular/efectos de los fármacos , Cloro/farmacología , Dentina/microbiología , Combinación de Medicamentos , Enterococcus faecalis/efectos de los fármacos , Enterococcus faecalis/crecimiento & desarrollo , Ácido Etidrónico/administración & dosificación , Técnicas In Vitro , Ensayo de Materiales , Microscopía Confocal , Hipoclorito de Sodio/administración & dosificación , Factores de Tiempo
2.
Environ Res ; 159: 135-142, 2017 11.
Artículo en Inglés | MEDLINE | ID: mdl-28800471

RESUMEN

A total of 417 striped red mullet, Mullus surmuletus, were analyzed to study microplastic ingestion and livers of fish were assessed to study effects of microplastics. Nearly one third (27.30%) of the individuals were quantified to ingest microplastics although there was no evidence of oxidative stress or cellular damage in the liver of fish which had ingested microplastics. A small increase in the activity of glutathione S-transferase (GST) of M. surmuletus was detected which could be suggesting an induction of the detoxification systems but these findings should be tested in laboratory conditions under a controlled diet and known concentration of microplastics. Fish from trammel fisheries, operating closer to land and targeting larger individuals, showed higher mean ingestion values than fish from trawling fisheries, and were related to body size, as microplastics ingested increased with total fish length. Consequently, ingestion values of microplastics were not related to sampling distance from land giving further evidence of the ubiquity of microplastics in the marine environment. Finally, Fourier Transform Infrared Spectroscopy (FTIR) analysis showed that the vast majority of microplastics were filament type and polyethylene terephthalate (PET) was the main identified component.


Asunto(s)
Contaminación de Alimentos/análisis , Estrés Oxidativo , Perciformes/metabolismo , Plásticos/metabolismo , Alimentos Marinos/análisis , Contaminantes Químicos del Agua/metabolismo , Animales , Ingestión de Alimentos , Monitoreo del Ambiente , Femenino , Masculino , España
3.
Eur J Nucl Med Mol Imaging ; 39(5): 771-81, 2012 May.
Artículo en Inglés | MEDLINE | ID: mdl-22258713

RESUMEN

PURPOSE: The aim of the study was to evaluate the volumetric integration patterns of standard MRI and (11)C-methionine positron emission tomography (PET) images in the surgery planning of gliomas and their relationship to the histological grade. METHODS: We studied 23 patients with suspected or previously treated glioma who underwent preoperative (11)C-methionine PET because MRI was imprecise in defining the surgical target contour. Images were transferred to the treatment planning system, coregistered and fused (BrainLAB). Tumour delineation was performed by (11)C-methionine PET thresholding (vPET) and manual segmentation over MRI (vMRI). A 3-D volumetric study was conducted to evaluate the contribution of each modality to tumour target volume. All cases were surgically treated and histological classification was performed according to WHO grades. Additionally, several biopsy samples were taken according to the results derived either from PET or from MRI and analysed separately. RESULTS: Fifteen patients had high-grade tumours [ten glioblastoma multiforme (GBM) and five anaplastic), whereas eight patients had low-grade tumours. Biopsies from areas with high (11)C-methionine uptake without correspondence in MRI showed tumour proliferation, including infiltrative zones, distinguishing them from dysplasia and radionecrosis. Two main PET/MRI integration patterns emerged after analysis of volumetric data: pattern vMRI-in-vPET (11/23) and pattern vPET-in-vMRI (9/23). Besides, a possible third pattern with differences in both directions (vMRI-diff-vPET) could also be observed (3/23). There was a statistically significant association between the tumour classification and integration patterns described above (p < 0.001, κ = 0.72). GBM was associated with pattern vMRI-in-vPET (9/10), low-grade with pattern vPET-in-vMRI (7/8) and anaplastic with pattern vMRI-diff-vPET (3/5). CONCLUSION: The metabolically active tumour volume observed in (11)C-methionine PET differs from the volume of MRI by showing areas of infiltrative tumour and distinguishing from non-tumour lesions. Differences in (11)C-methionine PET/MRI integration patterns can be assigned to tumour grades according to the WHO classification. This finding may improve tumour delineation and therapy planning for gliomas.


Asunto(s)
Glioma/diagnóstico , Glioma/patología , Imagen por Resonancia Magnética/métodos , Metionina , Tomografía de Emisión de Positrones/métodos , Carga Tumoral , Adolescente , Adulto , Anciano , Femenino , Glioma/diagnóstico por imagen , Glioma/cirugía , Humanos , Imagenología Tridimensional , Masculino , Persona de Mediana Edad , Clasificación del Tumor , Factores de Tiempo , Adulto Joven
4.
Clin Transl Oncol ; 22(11): 1909-1922, 2020 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-32222898

RESUMEN

The molecular biology of human glioma is a complex and fast-growing field in which basic research needs to meet clinical expectations in terms of anti-tumor efficacy. Although much effort is being done in molecular biology research, significant contribution to the quality of life and overall survival still lacks. The vastness of molecular biology literature makes it virtually impossible for clinicians to keep up to date in the field. This paper reviews some practical concepts regarding glioma tumorigenesis from the clinician's perspective. Five main aspects are discussed: major intracellular signaling pathways involved in glioma formation; genomic, epigenetic and transcriptomic relevant features of glioma; the prognostic and predictive values of molecular markers according to the new WHO classification of glial tumors; the importance of molecular and cellular heterogeneity in glioblastoma, responsible for its therapy resistance; and the interaction between glioma and the immune system, in view of the novel and promising targeted therapies.


Asunto(s)
Neoplasias Encefálicas/genética , Glioma/genética , Neoplasias Encefálicas/irrigación sanguínea , Neoplasias Encefálicas/etiología , Neoplasias Encefálicas/patología , Glioma/irrigación sanguínea , Glioma/etiología , Glioma/patología , Humanos , Biología Molecular , Transducción de Señal/fisiología , Transcriptoma
5.
Food Chem Toxicol ; 139: 111248, 2020 May.
Artículo en Inglés | MEDLINE | ID: mdl-32156568

RESUMEN

Polyphenols are secondary metabolites widely distributed in many plant foods, such a tea, coffee, chocolate and fruits. The consumption of these compounds is related to the improvement or amelioration of many diseases, including diabetes. Nevertheless, the great barrier to the therapeutic use of polyphenols is the low bioavailability of these compounds once ingested. For that reason, the encapsulation of polyphenols in different matrices may protect them from digestion and improve their release and subsequent absorption to obtain target-specific health effects. Some studies have reported the beneficial effect of encapsulation to increase both bioavailability and bioaccessibility. However, these works have mostly been carried out in vitro and few studies are specifically addressed at improving diabetes. In the current work, an overview of the knowledge related to nanoparticles and their use in the diabetic condition has been reviewed.


Asunto(s)
Diabetes Mellitus/terapia , Polifenoles/farmacocinética , Animales , Antioxidantes/análisis , Antioxidantes/farmacocinética , Disponibilidad Biológica , Cacao/química , Café/química , Manejo de la Enfermedad , Modelos Animales de Enfermedad , Medicina Basada en la Evidencia , Frutas/química , Humanos , Hipoglucemiantes/análisis , Hipoglucemiantes/farmacocinética , Nanopartículas/química , Polímeros/química , Polifenoles/análisis , Sustancias Protectoras/análisis , Sustancias Protectoras/farmacocinética , Té/química
6.
Sci Rep ; 10(1): 11252, 2020 07 09.
Artículo en Inglés | MEDLINE | ID: mdl-32647185

RESUMEN

Environmental enrichment is considered as a recommended tool to guarantee or improve the welfare of captive fish. This study demonstrates for the first time that structural environmental enrichment enhances cognition, exploratory behaviour and brain physiological functions of gilthead seabream (Sparus aurata). Seabream was reared in groups (n = 15) during 60 days under two different treatments: enriched tanks with plant-fibre ropes (EE) or bare/non-enriched tanks (NE). Fish were then exposed to a purpose-built maze for 1 h every second day in four trials. Analysis of video recordings showed that seabream under EE conditions presented higher overall exploratory behaviour, spatial orientation and learning capability compared to seabream from NE conditions. Results from brain monoamines analyses may suggest increased recent dopaminergic activity in telencephalon, known to be involved in learning processes; and increased serotonergic activity in cerebellum, involved in the coordination of balance, movements and orientation. In addition, EE-reared fish showed increased antioxidant activity in whole brain, with no apparent oxidative damage. Structural EE seemed to induce an hormetic response on juvenile seabream, improving their welfare status during captivity. Application of this kind of physical structure might be feasible at fish farms as a passive and non-invasive tool to improve welfare of intensively cultured seabream.


Asunto(s)
Conducta Animal , Encéfalo/fisiología , Conducta Exploratoria , Dorada/fisiología , Crianza de Animales Domésticos/métodos , Animales , Antioxidantes/metabolismo , Cognición , Dopamina/metabolismo , Ambiente , Peces , Análisis Multivariante , Estrés Oxidativo , Serotonina/metabolismo , Telencéfalo/fisiología
7.
Sci Total Environ ; 736: 139601, 2020 Sep 20.
Artículo en Inglés | MEDLINE | ID: mdl-32485379

RESUMEN

Posidonia oceanica is an endemic marine phanerogam of the Mediterranean Sea for that is very sensitive to the environmental changes, especially those related to human activities. The aim of this study was to evaluate the oxidative stress status of P. oceanica meadows exposed to spillage of hypersaline water from a desalination station by using biomarkers. Leaf samples of P. oceanica were obtained from 4 different points exposed to different levels of salinity water. Samples from the area with the highest salinity conditions were 75% shorter than the samples from the control area. Exposure to high salinity induced an increase in the levels of oxidative stress markers (malondialdehyde (MDA) and protein carbonyls). Interestingly, in the area with the highest salinity the activities of glutathione peroxidase, glutathione reductase and glutathione-s-transferase were significantly induced respect to the other studies areas, while catalase (CAT) and superoxide dismutase (SOD) activities were lower. In addition, salinity induced a progressive increase in non-enzymatic antioxidants (polyphenols and glutathione) and in total antioxidant capacity reaching the highest concentrations in samples directly affected by the saline discharge. In conclusion chronic exposure to high salinity induced an increase in total antioxidant capacity in P. oceanica. However, this increase was not enough to protect the plant against oxidative stress as it is evidenced by the raise in oxidative stress markers. The obtained data suggest that high salinity conditions deactivated CAT and SOD antioxidant enzymes and caused an increase in non-enzymatic antioxidants (polyphenols and glutathione) and in glutathione-related enzymes.


Asunto(s)
Alismatales , Agua , Antioxidantes , Catalasa , Pradera , Mar Mediterráneo , Estrés Oxidativo , Superóxido Dismutasa
8.
Rev Neurol ; 66(11): 387-394, 2018 Jun 01.
Artículo en Español | MEDLINE | ID: mdl-29790572

RESUMEN

INTRODUCTION: Infantile cerebral palsy is a well-known condition, the prevalence of which has varied only slightly over the years. The most common subtype is spastic diplegia, and spasticity is the most disabling symptom. Its treatment involves a multidisciplinary intervention that includes rehabilitation, the use of drugs, and orthopaedic and nervous system surgery, where selective dorsal rhizotomy is a prominent procedure. AIM: To present a thorough review of the use, indication and long-term consequences of selective dorsal rhizotomy. DEVELOPMENT: It is a minimally invasive procedure aimed at reducing spasticity in the lower extremities in order to improve the ability to walk, lessen pain, facilitate care in everyday life and diminish the need for orthopaedic surgery. The literature contains a wide range of criteria for its use, and the main indication is spastic diplegia with the absence of dystonia. It is routinely performed in several countries, while we have no evidence of its application in ours. CONCLUSIONS: Following the literature review, we believe there is enough experience to state that selective dorsal rhizotomy is a safe and simple technique from which many patients with spasticity of the lower limbs secondary to infantile cerebral palsy can benefit in both the short and the long term.


TITLE: Rizotomia dorsal selectiva: revision bibliografica de esta tecnica para el tratamiento de la espasticidad en la paralisis cerebral infantil.Introduccion. La paralisis cerebral infantil conforma una entidad bien conocida cuya prevalencia ha variado poco a lo largo de los años. El subtipo mas comun es la diplejia espastica, y la espasticidad es el sintoma mas incapacitante. Para su tratamiento es preciso una intervencion multidisciplinar que auna rehabilitacion, uso de farmacos y cirugia ortopedica y del sistema nervioso, donde destaca la rizotomia dorsal selectiva. Objetivo. Mostrar una amplia revision del uso, indicaciones y consecuencias a largo plazo de la rizotomia dorsal selectiva. Desarrollo. Se trata de una intervencion minimamente invasiva dirigida a disminuir la espasticidad en las extremidades inferiores con el fin de mejorar la deambulacion, aminorar el dolor, facilitar los cuidados de la vida diaria y reducir la necesidad de cirugias ortopedicas. En la bibliografia hay una amplia variabilidad de criterios para su uso, y la principal indicacion es la diplejia espastica con ausencia de distonia. Diversos paises lo practican de forma rutinaria, mientras que en el nuestro no tenemos aun constancia de ello. Conclusiones. Tras la revision de la bibliografia consideramos que existe suficiente experiencia como para afirmar que la rizotomia dorsal selectiva es una tecnica segura y sencilla de la que muchos pacientes con espasticidad de las extremidades inferiores secundaria a paralisis cerebral infantil se pueden beneficiar a corto y largo plazo.


Asunto(s)
Parálisis Cerebral/cirugía , Rizotomía/métodos , Parálisis Cerebral/terapia , Niño , Preescolar , Terapia Combinada , Medicina Basada en la Evidencia , Estudios de Seguimiento , Humanos , Laminectomía , Metaanálisis como Asunto , Limitación de la Movilidad , Espasticidad Muscular/cirugía , Modalidades de Fisioterapia , Ensayos Clínicos Controlados Aleatorios como Asunto , Índice de Severidad de la Enfermedad , Resultado del Tratamiento
9.
Radiologia (Engl Ed) ; 60(2): 136-142, 2018.
Artículo en Inglés, Español | MEDLINE | ID: mdl-29361284

RESUMEN

OBJECTIVE: To report our experience in the use of 3 tesla intraoperative magnetic resonance imaging (MRI) in neurosurgical procedures for tumors, and to evaluate the criteria for increasing the extension of resection. MATERIAL AND METHODS: This retrospective study included all consecutive intraoperative MRI studies done for neuro-oncologic disease in the first 13 months after the implementation of the technique. We registered possible immediate complications, the presence of tumor remnants, and whether the results of the intraoperative MRI study changed the surgical management. We recorded the duration of surgery in all cases. RESULTS: The most common tumor was recurrent glioblastoma, followed by primary glioblastoma and metastases. Complete resection was achieved in 28%, and tumor remnants remained in 72%. Intraoperative MRI enabled neurosurgeons to improve the extent of the resection in 85% of cases. The mean duration of surgery was 390±122minutes. CONCLUSION: Intraoperative MRI using a strong magnetic field (3 teslas) is a valid new technique that enables precise study of the tumor resection to determine whether the resection can be extended without damaging eloquent zones. Although the use of MRI increases the duration of surgery, the time required decreases as the team becomes more familiar with the technique.


Asunto(s)
Neoplasias Encefálicas/diagnóstico por imagen , Neoplasias Encefálicas/cirugía , Imagen por Resonancia Magnética , Monitoreo Intraoperatorio/métodos , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Niño , Preescolar , Femenino , Humanos , Imagen por Resonancia Magnética/métodos , Masculino , Persona de Mediana Edad , Procedimientos Neuroquirúrgicos/métodos , Estudios Retrospectivos , Adulto Joven
10.
Brain Res Bull ; 71(4): 372-5, 2007 Jan 09.
Artículo en Inglés | MEDLINE | ID: mdl-17208654

RESUMEN

Pilocarpine is a cholinergic agonist capable to induce seizures and an epilepticus-like state in rodents. This status epilepticus (SE) is an useful animal model to study the development and understanding of the neuropathology, behavioural and electroencephalographic alterations of human temporal lobe epilepsy. It has been suggested a relationship between SE and reactive oxygen species (ROS) that can result in seizure-induced neurodegeneration. The aim of this study was to evaluate the existence of oxidative damage and the changes in the antioxidant system in cortex after administration of a high pilocarpine dose. Rats were injected with pilocarpine (350 mg/kg i.p.) or with saline as control and 2h after the animals were sacrificed. Malondialdehyde (MDA) levels, as marker of lipid peroxidation, significantly increased (64%) after pilocarpine treatment evidencing oxidative damage. Antioxidant enzyme activities--catalase (CAT), glutathione peroxidase (GP) and superoxide dismutase (SOD)--significantly increased in response to pilocarpine (28%, 28% and 21%, respectively). GP and Mn-SOD gene expression were induced by pilocarpine treatment. Vitamin E concentration in brain cortex decreased (15%) as result of pilocarpine administration. In conclusion, the high dose of pilocarpine, used in the present study, induces oxidative damage and increases antioxidant enzyme activities and expression in brain cortex. Moreover, increased lipid peroxidation produces the consumption of Vitamin E.


Asunto(s)
Antioxidantes/metabolismo , Corteza Cerebral/efectos de los fármacos , Agonistas Muscarínicos/farmacología , Estrés Oxidativo/efectos de los fármacos , Pilocarpina/farmacología , Animales , Química Encefálica/efectos de los fármacos , Corteza Cerebral/enzimología , Peroxidación de Lípido/efectos de los fármacos , Masculino , Malondialdehído/metabolismo , ARN/biosíntesis , ARN/aislamiento & purificación , Ratas , Ratas Wistar , Especies Reactivas de Oxígeno/metabolismo , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Vitamina E/metabolismo
11.
Brain Res Bull ; 72(4-6): 183-6, 2007 May 30.
Artículo en Inglés | MEDLINE | ID: mdl-17452279

RESUMEN

This commentary is referred to the review signed by Rattemborg [N.C. Rattenborg, Evolution of slow wave sleep and palliopallial connectivity in mammals and birds. A hypothesis. Brain Res. Bull. 69 (2006) 20-29]. We propose that the review missed important aspects in relation to the characteristics of sleep in poikilotherm vertebrates and in the evolution of sleep. Poikilotherms continuously show an EEG dominated by slow waves, but its highest amplitude appears not during sleep, but during active waking. In addition, they show an arousal reaction which consists in an increase in EEG amplitude and synchrony, opposite to mammals and birds. As a consequence, most of the conclusions proposed in the review should be rejected.


Asunto(s)
Evolución Biológica , Aves/fisiología , Mamíferos/fisiología , Sueño/fisiología , Telencéfalo/fisiología , Animales , Electroencefalografía/métodos , Telencéfalo/anatomía & histología , Vigilia/fisiología
12.
Brain Res Bull ; 69(5): 587-92, 2006 May 15.
Artículo en Inglés | MEDLINE | ID: mdl-16647587

RESUMEN

Cholinergic and gabaergic systems play an important role generating electroencephalographic activity and regulating vigilance states. Pilocarpine is a cholinergic agonist commonly used to induce seizures and an epilepticus-like state in rodents. A relationship between status epilepticus and reactive oxygen species has been also suggested which could result in seizure-induced neurodegeneration. The aim of this study was to evaluate the existence of oxidative damage as well as the antioxidant enzyme response in cortex and hippocampus after the administration of an intraperitoneal (350 mg/kg) and an intracerebroventricular (360 microg, 1 microl) pilocarpine injection in rats. The GABA agonist muscimol (1 mg/kg, i.p.), with described neuroprotective properties, was used as a negative control. Only systemic pilocarpine induced oxidative damage. Malondialdehyde levels, as a marker of lipid peroxidation (LP), increased in both regions (55-56%). Catalase (52-80%) and superoxide dismutase (53-60%) activities also rose in both regions but glutathione peroxidase activity only increased in cortex (45%). Glutathione reductase and caspase-3 activity did not change. In conclusion, systemic pilocarpine produced oxidative brain damage, whereas local pilocarpine brain injection had no effects. Moreover, the enzymatic determinations performed in this study are a good tool to study brain injury in pharmacological manipulations such as the ones used in short recording EEG studies.


Asunto(s)
Antioxidantes/análisis , Encéfalo/efectos de los fármacos , Convulsivantes/administración & dosificación , Estrés Oxidativo/efectos de los fármacos , Pilocarpina/administración & dosificación , Animales , Antioxidantes/metabolismo , Caspasa 3 , Caspasas/efectos de los fármacos , Caspasas/metabolismo , Catalasa/efectos de los fármacos , Catalasa/metabolismo , Radicales Libres/metabolismo , Agonistas del GABA/farmacología , Glutatión Peroxidasa/efectos de los fármacos , Glutatión Peroxidasa/metabolismo , Glutatión Reductasa/efectos de los fármacos , Glutatión Reductasa/metabolismo , Inyecciones Intraventriculares , Peroxidación de Lípido/efectos de los fármacos , Masculino , Muscimol/farmacología , Ratas , Ratas Wistar , Superóxido Dismutasa/efectos de los fármacos , Superóxido Dismutasa/metabolismo
13.
J Food Prot ; 62(10): 1218-22, 1999 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-10528731

RESUMEN

Fumonisin B1 (FB1) is a common contaminant of corn worldwide and is responsible for several diseases of animals. In the preparation of tortillas, corn is treated with lime (producing nixtamal) that when heated hydrolyzes at least a portion of the FB1 to the aminopentol backbone (AP1), another known toxin. This study analyzed the amounts of FB1 and AP1 in tortillas and nixtamal from two communities in the central highlands of Guatemala where corn is a major dietary staple (Santa Maria de Jesus, Sacatepequez, and Patzicia, Chimaltenango). The amounts of FB1 and AP1 in tortillas from Santa Maria de Jesus were, respectively, 0.85 +/- 2.0 and 26.1 +/- 38.5 microg/g dry weight (mean +/- SD), and from Patzicia were 2.2 +/- 3.6 and 5.7 +/- 9.4 microg/g dry weight. Less than 6% of the tortillas from both locations contained > or = 10 microg FB1/g dry weight; whereas, 66% of the samples from Santa Maria de Jesus and 29% from Patzicia contained > or = 10 microg AP1/g dry weight. The highest amount of AP1 (185 microg/g dry weight) was found in tortillas from Santa Maria de Jesus. The highest amounts of FB1 were 6.5 and 11.6 microg/g dry weight in tortillas from Santa Maria de Jesus and Patzicia, respectively. The mean concentration of FB1 in nixtamal was significantly higher in Santa Maria de Jesus compared to Patzicia. Surprisingly, AP1 was not detected in any of the nixtamal samples. The human impact of exposure to these amounts of fumonisins is not known. However, based on findings with other animals, where corn is a dietary staple, long-term consumption of FB1 and AP1 (especially at > or = 10 microg/g of the diet) may pose a risk to human health.


Asunto(s)
Ácidos Carboxílicos/análisis , Carcinógenos Ambientales/análisis , Contaminación de Alimentos , Fumonisinas , Zea mays/química , Compuestos de Calcio , Conservación de Alimentos , Guatemala , Óxidos
14.
J Air Waste Manag Assoc ; 48(7): 578-91, 1998 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-9706038

RESUMEN

The 1988 Alternative Motor Fuels Act and the 1990 Clean Air Act Amendments require examination of the potential to favorably influence air quality by changing the composition of motor vehicle fuels. Motor vehicle tailpipe and evaporative emissions were characterized using laboratory simulations of roadway driving conditions and a variety of vehicle-fuel technologies (reformulated gasoline (RFG), methanol (M85), ethanol (E85), and natural gas (CNG)). Speciated organic compound (with Carter MIR ozone potential), CO, and NO(x) emission rates and fuel economy were characterized. The Carter MIR ozone potential of combined Federal Test Procedure (FTP) tailpipe and evaporative emissions was reduced more than 90% with CNG relative to RFG, M85, and E85 fuels. FTP toxic compound emissions (benzene, formaldehyde, acetaldehyde, and 1,3-butadiene) were greater with M85 and E85 fuels than with RFG fuel, and less with CNG fuel than RFG fuel. The most abundant toxic compound was benzene with RFG fuel, formaldehyde with M85 fuel, and acetaldehyde with E85 fuel. FTP MPG fuel economies were reduced with M85 and E85 fuels relative to RFG fuel, consistent with their lower BTU/gal. Energy efficiencies (BTU/mi) were improved with all the alternative fuels relative to RFG. Carter MIR ozone potential was generally reduced with the alternative fuels relative to RFG fuel under REP05 (high speeds and acceleration rates) driving conditions (most significantly with CNG). Toxic aldehyde emissions were reduced under REP05 conditions relative to FTP conditions with all the tested fuels, and toxic benzene emissions were elevated under high acceleration conditions.


Asunto(s)
Contaminantes Atmosféricos/análisis , Ozono/análisis , Emisiones de Vehículos/análisis , Legislación como Asunto , Estados Unidos , United States Environmental Protection Agency
15.
J Air Waste Manag Assoc ; 52(3): 259-72, 2002 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-11924857

RESUMEN

A laboratory study was conducted to evaluate the potential for secondary organic aerosol formation from emissions from automotive exhaust. The goal was to determine to what extent photochemical oxidation products of these hydrocarbons contribute to secondary organic aerosol (SOA) and how well their formation is described by recently developed models for SOA formation. The quality of a surrogate was tested by comparing its reactivity with that from irradiations of authentic automobile exhaust. Experiments for secondary particle formation using the surrogate were conducted in a fixed volume reactor operated in a dynamic mode. The mass concentration of the aerosol was determined from measurements of organic carbon collected on quartz filters and was corrected for the presence of hydrogen, nitrogen, and oxygen atoms in the organic species. A functional group analysis of the aerosol made by Fourier transform infrared (FTIR) spectroscopy indicated


Asunto(s)
Hidrocarburos Aromáticos/química , Rayos Ultravioleta , Emisiones de Vehículos , Aerosoles , Ciudades , Compuestos Orgánicos , Oxidación-Reducción , Tamaño de la Partícula , Fotoquímica , Espectroscopía Infrarroja por Transformada de Fourier
16.
Enferm. univ ; 16(1): 41-51, ene.-mar. 2019. ilus
Artículo en Español | LILACS-Express | LILACS, BDENF - Enfermería | ID: biblio-1001922

RESUMEN

Objetivo: Explorar la práctica pedagógica docente en la formación para el cuidado de enfermería en la Universidad Nacional Toribio Rodríguez de Mendoza de Amazonas. Material y método: Estudio cualitativo, exploratorio, descriptivo: la muestra la conformaron 21 informantes. La recolección de información fue por medio de entrevista semi estructurada. El análisis siguió un proceso de codificación abierta, axial y selectiva hasta obtener categorías emergentes. Resultados: Se identificaron las siguientes categorías: I) Convivencia y relaciones de cuidado/descuido en la formación de enfermería; II) (Des)articulación teórico- práctica en la enseñanza/aprendizaje del cuidado de enfermería: hacia la integración docente-asistente; III) Complementariedad docente/estudiante para la construcción de conocimiento y estrategias didácticas. Conclusiones: La pedagogía para el cuidado de enfermería se evidencia en un espacio de cuidado/descuido, demandan integración docencia-asistencia y se motivan para el fortalecimiento de competencias pedagógico didácticas, a través del aprendizaje basado en problemas, casos hipotéticos, laboratorios vivenciales y sociodramas e incluir como ejes trasversales el cuidado y la investigación.


Objective: To explore the pedagogical practice in nursing care formation among teachers of the Universidad Nacional Toribio Rodríguez de Mendoza de Amazonas. Method and materials: This is a qualitative, exploratory and descriptive study, with a sample of 21 informants. Data were gathered using semi-structured interviews. The analysis followed an open, axial, and selective coding process, until emerging categories were identified. Results: The following categories emerged: I) Co-living and care/negligence relationships in nursing formation; II) (Lack of) theory-practice articulation in teaching/learning nursing care: towards the teacher-assistant integration; III) Teacher/student complementarity in the construction of knowledge and didactical strategies. Conclusions: Pedagogy in nursing care is evidenced within a care/negligence space, and thus, it is necessary to strengthen the integration among teaching and assistance improving the pedagogical competencies through methodologies such as learning based on problem solving, presentation of hypothetical cases, use of laboratories, including those for high-fidelity simulation, among others.


Objetivo: Explorar a prática pedagógica docente na formação para o cuidado de enfermagem na Universidad Nacional Toribio Rodríguez de Mendoza de Amazonas. Material e método: Estudo qualitativo, exploratório, descritivo: a amostra a conformaram 21 informantes. A recolecção de informação foi por meio de entrevista semiestruturada. A análise seguiu um processo de codificação aberta, axial e seletiva até obter categorias emergentes. Resultados: Identificaram-se as seguintes categorias: I) Convivência e relações de cuidado/descuido na formação de enfermagem; II) (Des)articulação teórico -prática no ensino/aprendizagem do cuidado de enfermagem: para a integração docente- assistente; III) Complementaridade docente/estudante para a construção de conhecimento e estratégias didáticas. Conclusões: A pedagogia para o cuidado de enfermagem evidencia-se em um espaço de cuidado/descuido, demandam integração, docência-assistência e motivam-se para o fortalecimento de competências pedagógico didáticas, através da aprendizagem, baseada em problemas, casos hipotéticos, laboratórios vivenciais e sociodramas e incluir como eixos transversais o cuidado e a pesquisa.


Asunto(s)
Humanos , Masculino , Femenino , Enfermería , Capacitación Profesional , Docentes de Enfermería
18.
Physiol Behav ; 105(4): 1007-13, 2012 Feb 28.
Artículo en Inglés | MEDLINE | ID: mdl-22138442

RESUMEN

Cholinergic systems play a significant role in regulating a variety of behavioral functions in mammals and birds. The aim of this work is to study the effects of the muscarinic agonist pilocarpine on behavioral states by visual inspection and electroencephalographic recording; also, locomotor activity was continuously recorded by infrared interruption system in ring doves. The current results in birds demonstrated that the muscarinic agonist pilocarpine (1 and 3mg/kg, i.p.) primarily induced theta activity in addition to promote passive waking, while diminished active waking, the EEG slow wave rhythm and REM sleep in ring doves. The locomotor activity recorded continuously in ring doves diminished after pilocarpine treatment, which was in good agreement with the observed reduction of active waking derived of the EEG study. Altogether, the current results are similar to the effects of pilocarpine previously reported in mammals. In conclusion, hippocampal theta rhythm in birds suggests that this rhythm is an ancestral property of hippocampal function and similar cholinergic mechanisms regulate vigilance states and theta generation in mammals and birds.


Asunto(s)
Nivel de Alerta/efectos de los fármacos , Electroencefalografía/efectos de los fármacos , Electroencefalografía/psicología , Actividad Motora/efectos de los fármacos , Agonistas Muscarínicos/farmacología , Pilocarpina/farmacología , Ritmo Teta/efectos de los fármacos , Animales , Nivel de Alerta/fisiología , Columbidae , Electroencefalografía/métodos , Electroencefalografía/estadística & datos numéricos , Ritmo Teta/fisiología
19.
Behav Brain Res ; 216(1): 238-46, 2011 Jan 01.
Artículo en Inglés | MEDLINE | ID: mdl-20699107

RESUMEN

Serotonergic system is implicated on sleep-waking states in mammals. Since studies on serotonin regulation of sleep in birds are scarce, ring dove was chosen as experimental subject in the present work. The role of the neurotransmitter serotonin on vigilance states was studied in ring doves intraperitoneally treated with the 5-HT(1A) agonist 8-OH-DPAT, the 5-HT(1A) antagonist WAY100635 and the inhibitor of serotonin synthesis para-chlorophenylalanine (PCPA) by means of behavioural, electrophysiological and infrared actimetry criteria. 8-OH-DPAT (1 mg/kg) treatment increased locomotor activity, active waking and grooming states and reduced SWS and REM sleep. Pre-treatment with WAY100635 (0.5 mg/kg) prevented the effects induced by 8-OH-DPAT. Serotonin depletion induced by PCPA treatment (two consecutive injections of 300 mg/kg over two consecutive days) reduced locomotor activity, waking and grooming activity while increased both SWS and REM sleep. Moreover, 8-OH-DPAT (0.5 mg/kg) in PCPA treated ring doves produced a notable rise in the locomotor activity, active waking and grooming states, while it decreased sleep. Altogether, the results support the idea that serotonin plays an active role in wakefulness, probably through the activation of 5-HT(1A) receptors that increases wake activities and reduces sleep in ring doves.


Asunto(s)
Nivel de Alerta/efectos de los fármacos , Actividad Motora/efectos de los fármacos , Antagonistas de la Serotonina/farmacología , Agonistas de Receptores de Serotonina/farmacología , Sueño/efectos de los fármacos , Vigilia/efectos de los fármacos , 8-Hidroxi-2-(di-n-propilamino)tetralin/farmacología , Animales , Atención/efectos de los fármacos , Columbidae , Electroencefalografía , Fenclonina/farmacología , Piperazinas/farmacología , Piridinas/farmacología
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