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1.
Childs Nerv Syst ; 34(6): 1125-1134, 2018 06.
Artículo en Inglés | MEDLINE | ID: mdl-29671042

RESUMEN

PURPOSE: We investigated the possible beneficial effects that hyperbaric oxygen therapy could offer in different brain structures affected by ventriculomegaly in pup rats submitted to experimental hydrocephalus. METHODS: Seven-day-old Wistar rats were submitted to hydrocephalus by intracisternal injection of 10% kaolin into the cisterna magna. The animals were divided into four groups: control (n = 5); control with HBOT (3ATA/2 h/day) (n = 5); untreated hydrocephalic (n = 10); hydrocephalic treated with HBOT (3ATA/2 h/day) (n = 10). The treatment with HBOT was performed daily for 14 days post-induction of hydrocephalus. To evaluate the response to treatment, behavioral tests (open field, Morris water maze, and activity monitor) were performed. After 14 days, the animals were euthanized, and the brain was removed for histological (hematoxylin-eosin and solochrome-cyanine) and immunohistochemical (GFAP and Ki-67) studies. RESULTS: The hyperbaric treatment, although not causing changes in ventricular enlargement, resulted in a significant improvement in the behavioral performance (p = 0.0001), with greater agility and exploration of the environment, preservation of spatial memory, and greater learning capacity (p = 0.0001). Through the immunohistochemical study, the astrocytic activity (glial fibrillary acidic protein) in the corpus callosum (p = 0.0001) and in the germinative matrix (p = 0.0033) was significantly reduced as compared to that in the H group. CONCLUSION: The results suggest that hyperbaric treatment bettered the behavioral performance and offered benefits to the structures affected by the ventricular increase helping to recover the brain damages. In this way, the HBOT it can be considered an adjuvant therapy for the treatment of hydrocephalus.


Asunto(s)
Lesiones Encefálicas/patología , Gliosis/patología , Hidrocefalia/patología , Oxigenoterapia Hiperbárica/métodos , Animales , Lesiones Encefálicas/etiología , Hidrocefalia/complicaciones , Masculino , Ratas , Ratas Wistar
2.
Ecotoxicol Environ Saf ; 160: 191-196, 2018 Sep 30.
Artículo en Inglés | MEDLINE | ID: mdl-29804016

RESUMEN

Due to their high trophic level, raptor species may serve as important indicators of environmental contamination by heavy metals. This study was conducted to determine if the habitat of the black kite (Milvus migrans) is contaminated by heavy metals and arsenic and to assess the degree and type of exposure that may be present. For this purpose, this study was conducted on a group of captive birds (n = 12) and on a group of free-living birds admitted to two wildlife rehabilitation centers (n = 31). Blood samples were taken for analysis of arsenic (As), mercury (Hg) and lead (Pb) concentrations by inductively coupled plasma mass spectrometry (ICP-MS). Captive birds had the lowest blood concentrations for all toxic elements examined, but significant differences from the concentrations found in free-living birds were only observed for Hg and Pb (p < 0.01). Arsenic concentrations were almost three times higher in free-living birds (4.521 ±â€¯5.695 µg/dl) then in captive birds (1.566 ±â€¯0.753 µg/dl). In all the samples of captive birds' mercury was not detected, while in free-living birds we observed a concentration of 7.493 ±â€¯8.464 µg/dl (p < 0.01). Regarding lead, we observed a concentration almost four-fold higher in free-living birds (19.430 ±â€¯29.294 µg/dl) then in captive birds (4.449 ±â€¯1.987 µg/dl) (p < 0.01). Therefore, available sources of Pb and Hg seem to be present in the habitat of the black kite.


Asunto(s)
Arsénico/sangre , Contaminantes Ambientales/sangre , Falconiformes/sangre , Plomo/sangre , Mercurio/sangre , Animales , Monitoreo del Ambiente , Portugal
3.
Stress ; 20(5): 513-522, 2017 09.
Artículo en Inglés | MEDLINE | ID: mdl-28845717

RESUMEN

OBJECTIVES: Wildlife capture is an essential management tool that induces a reactive homeostasis response in the captured animals. The aim of this study was to characterize the reactive homeostatic response to trapping in free-ranging wolves and assess the mitigation achieved by reducing the duration of restraint. MATERIALS AND METHODS: Making use of wolves captured for ecological research as a model for wildlife acute stress, we characterize 25 reactive homeostasis mediators and we assess the effect on these mediators of reducing the duration of restraint in trap by using remote trap activation alarms. RESULTS: Free-ranging wolves trapped by leg-hold snares (n = 15) showed higher stress leukogram, tissue injury and hematocrit; while lower glucose, ions and cardiac rate compared with captive wolves. They also showed higher leukocyte count and creatine kinase; but lower hematocrit, cardiac rate and rectal body temperature compared to wolves captured by darting from a helicopter. Daily distance travelled was significantly lower up to day 12 post-capture compared to the remainder of the telemetry follow-up and this effect was more noticeable on the nocturnal distance travelled. Reducing the duration of restraint on trap significantly lowered the stress leukogram and dehydration. Daily distance travelled during the night by wolves captured using trap-alarms was significantly lower only up to day 4 post-capture compared to up to day 28 for wolves captured without trap-alarms. DISCUSSION: The capture method and duration of restraint influence the reactive homeostasis response of free-ranging wolves. Technological solutions that reduce the duration of restraint on trap significantly dampen this influence. CONCLUSIONS: Wildlife trapping actions should strive to minimize the delay from capture to manipulation.


Asunto(s)
Conducta Animal , Glucemia/metabolismo , Creatina Quinasa/metabolismo , Frecuencia Cardíaca , Restricción Física/métodos , Estrés Psicológico/metabolismo , Animales , Animales Salvajes , Temperatura Corporal , Deshidratación/fisiopatología , Femenino , Hematócrito , Recuento de Leucocitos , Masculino , Restricción Física/psicología , Estrés Psicológico/sangre , Estrés Psicológico/fisiopatología , Estrés Psicológico/psicología , Factores de Tiempo , Viaje , Lobos
4.
Ecotoxicol Environ Saf ; 136: 104-110, 2017 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-27833047

RESUMEN

Over the past decades, the presence of micronucleated blood cells has been used to detect genotoxic effects of xenobiotics in fish, amphibians and birds. This study assessed the frequency of micronuclei (MN) and other nuclear abnormalities in erythrocytes of individuals of Ardea cinerea and Ciconia ciconia retrieved for rehabilitation in order to evaluate the influence of age, temporal and spatial factors on the occurrence of DNA damage in Portuguese wild birds. Blood smears from 65 birds with different life-history backgrounds (e.g. geographic origin, age) were collected between 2007 and 2011 and the frequency of erythrocyte nuclear abnormalities (ENAs) was analysed. Differences in DNA damage between ages were observed to occur in C. ciconia, with chicks displaying significantly higher frequencies of ENAs (both when looking at total ENAs or only MN frequency) than juveniles and adults. Additionally, significant differences in ENAs frequencies were observed between different years and geographic origins, whereas MN frequency alone did not show significant alterations concerning spatial and temporal variations. These results suggest that the assessment of ENAs rather than MN frequency alone may be a useful and valuable tool to complement the evaluation of DNA damage in populations of birds, as prompted by individual life-history traits and environmental factors.


Asunto(s)
Aves/metabolismo , Daño del ADN , Exposición a Riesgos Ambientales , Eritrocitos/efectos de los fármacos , Factores de Edad , Animales , Femenino , Geografía , Masculino , Pruebas de Micronúcleos , Portugal , Estaciones del Año
5.
J Avian Med Surg ; 30(3): 274-279, 2016 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-27736221

RESUMEN

Avian scavengers that typically include game birds and mammals in their diets are at risk of lead poisoning from ingestion of carcasses with fragmented or residual lead ammunition that is used in hunting. Thus, lead may be one of the threats that the griffon vulture ( Gyps fulvus ) faces in the Iberian Peninsula and particularly in Portugal, where their conservation status is considered to be near-threatened. This is the first report that details 3 cases of lead poisoning, associated with the ingestion of lead shot, in adult female griffon vultures found in the Iberian Peninsula. The birds were found prostrate and immediately transferred to a wildlife rehabilitation center, where they died within 24 hours after supportive treatment. Necropsy and histopathologic examinations were done in 2 birds and metal analyses were done in all birds to determine the birds' causes of death. In one vulture, 9 uneroded lead pellets were recovered from the stomach, and moderate to severe hemosiderosis was seen histologically in the liver, lungs, and kidneys. Diagnosis of lead poisoning was confirmed by results of metal analyses, which revealed extremely high lead concentrations in blood (969-1384 µg/dL), liver (309-1077 µg/g dry weight), and kidneys (36-100 µg/g dry weight) for all 3 vultures. To prevent lead poisoning in vultures and preserve their populations in the Iberian Peninsula, more resources are needed for diagnosis and treatment of wildlife in rehabilitation centers, new regulations enabling the abandonment of fallen stock in the field must be approved, and lead ammunition must be prohibited in big-game hunting.


Asunto(s)
Enfermedades de las Aves/inducido químicamente , Falconiformes , Intoxicación por Plomo/veterinaria , Plomo/toxicidad , Animales , Animales Salvajes , Enfermedades de las Aves/epidemiología , Femenino , Armas de Fuego , Intoxicación por Plomo/epidemiología , Portugal/epidemiología , España/epidemiología
6.
Healthc Q ; 19(2): 60-66, 2016.
Artículo en Inglés | MEDLINE | ID: mdl-27700976

RESUMEN

Integrating care for people with complex needs is challenging. Indeed, evidence of solutions is mixed, and therefore, well-designed, shared evaluation approaches are needed to create cumulative learning. The Toronto-based Building Bridges to Integrate Care (BRIDGES) collaborative provided resources to refine and test nine new models linking primary, hospital and community care. It used mixed methods, a cross-project meta-evaluation and shared outcome measures. Given the range of skills required to develop effective interventions, a novel incubator was used to test and spread opportunities for system integration that included operational expertise and support for evaluation and process improvement.


Asunto(s)
Prestación Integrada de Atención de Salud/métodos , Prestación Integrada de Atención de Salud/organización & administración , Afecciones Crónicas Múltiples , Continuidad de la Atención al Paciente , Atención a la Salud/organización & administración , Humanos , Ontario , Evaluación de Resultado en la Atención de Salud , Evaluación de Programas y Proyectos de Salud
7.
Carcinogenesis ; 36(4): 469-77, 2015 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-25586991

RESUMEN

Malignant melanoma is the most deadly form of skin cancer. There is a critical need to identify the patients that could be successfully treated by surgery alone and those that require adjuvant treatment. In this study, we demonstrate that the expression of tribbles2 (TRIB2) strongly correlates with both the presence and progression of melanocyte-derived malignancies. We examined the expression of TRIB2 in addition to 12 previously described melanoma biomarkers across three independent full genome microarray studies. TRIB2 expression was consistently and significantly increased in benign nevi and melanoma, and was highest in samples from patients with metastatic melanoma. The expression profiles for the 12 biomarkers were poorly conserved throughout these studies with only TYR, S100B and SPP1 showing consistently elevated expression in metastatic melanoma versus normal skin. Strikingly we confirmed these findings in 20 freshly obtained primary melanoma tissue samples from metastatic lesions where the expression of these biomarkers were evaluated revealing that TRIB2 expression correlated with disease stage and clinical prognosis. Our results suggest that TRIB2 is a meaningful biomarker reflecting diagnosis and progression of melanoma, as well as predicting clinical response to chemotherapy.


Asunto(s)
Biomarcadores de Tumor/genética , Proteínas Quinasas Dependientes de Calcio-Calmodulina/genética , Péptidos y Proteínas de Señalización Intracelular/genética , Melanoma/genética , Neoplasias Cutáneas/genética , Bases de Datos Factuales , Progresión de la Enfermedad , Humanos , Melanoma/diagnóstico , Osteopontina/biosíntesis , Pronóstico , Curva ROC , Subunidad beta de la Proteína de Unión al Calcio S100/biosíntesis , Neoplasias Cutáneas/diagnóstico , Melanoma Cutáneo Maligno
8.
Ecotoxicol Environ Saf ; 113: 295-301, 2015 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-25528380

RESUMEN

Griffon vultures (Gyps fulvus), by virtue of their position at the top of the food chain and as obligate scavengers, are at risk of accumulating and concentrating heavy metals in their tissues and may be more predisposed to their toxic effects. The aim of this study is to investigate heavy metal concentrations in Griffon vultures in Portugal and Catalonia, Spain and to determine if heavy metal concentrations in the blood of weak and/or injured Griffon vultures admitted to wildlife rehabilitation centres (WRC) reflect contamination profiles in the local, free-living and outwardly healthy population. Whole-blood samples taken from 121 Griffon vultures caught in the wild or admitted to WRC in Portugal and Catalonia, Spain were examined for cadmium (Cd), mercury (Hg) and lead (Pb) by inductively coupled plasma mass spectrometry (ICP-MS). Cd and Hg were not detected in most samples (98.3% and 95%, respectively), while Pb was detected in all birds in concentrations ranging between 4.97 and 300.23 µg/dl. Birds admitted to WRC had significantly lower Pb concentrations (24.15 ± 15.07 and 25.98 ± 18.04 µg/dl in Portugal and Catalonia, Spain, respectively) than animals caught in the wild (29.67 ± 13.19 and 42.22 ± 50.08 µg/dl in Portugal and Catalonia, Spain, respectively) (p<0.05). This may be explained by the fact that malnutrition was the main cause of admission of Griffon vultures to WRC, as ingestion has been described as the most significant pathway for Pb exposure in raptors. Therefore Griffon vultures admitted to WRC do not seem to be representative of the local, free-flying populations, so it remains necessary to continue catching when one intends to monitor Pb exposure in this species. The population of vultures captured in Catalonia, Spain showed the highest mean blood Pb concentration, perhaps due to the municipal rubbish dump located near the feeding station, with rubbish providing a significant fraction of their trophic needs. The ingestion of game meat with bullet fragments in carcasses or with Pb shots embedded in their flesh could also be the cause of the high blood Pb concentrations found in some vultures. The potential risk of Pb exposure in Griffon vulture populations must be given consideration, since most individuals evaluated had Pb concentrations between 20 and 100µg/dl, which is considered to be subclinical exposure to Pb, and which is above the threshold level at which Pb can affect antioxidant system in this species (15 µg/dl).


Asunto(s)
Falconiformes/sangre , Metales Pesados/sangre , Animales , Aves , Mercurio , Portugal , Rapaces , España
9.
J Zoo Wildl Med ; 46(4): 723-31, 2015 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-26667528

RESUMEN

The presence of multidrug-resistant (MDR) Escherichia coli has recently been reported in wild birds (gulls and birds of prey) that had no apparent exposure to antimicrobials. Little work has been done to assess the role of the food chain in the emergence and spread of MDR E. coli . In this study, we evaluated the presence of MDR E. coli in 29 fecal samples collected from wild birds living in a rehabilitation center (the center receives injured animals found in their natural habitat) and in eight feed samples. In total, 166 E. coli isolates were obtained: 129 from cloacal swabs and 37 from raw feed samples. The antimicrobial resistance profile of these isolates was determined, and we found that 75 isolates showed resistance to five or more drugs, resulting in a total of 38 different antimicrobial resistance patterns. Subsequently, the molecular characterization of 36 isolates, performed by pulsed-field gel electrophoresis, revealed a great similarity between isolates collected from various species of birds and also between these last ones and the ones found in their feed samples.


Asunto(s)
Antibacterianos/farmacología , Aves/microbiología , Farmacorresistencia Bacteriana Múltiple , Infecciones por Escherichia coli/veterinaria , Escherichia coli/efectos de los fármacos , Cadena Alimentaria , Animales , Animales Salvajes , Infecciones por Escherichia coli/microbiología , Peces/microbiología , Ratones , Conejos
10.
Breast Cancer Res ; 16(6): 482, 2014 Dec 09.
Artículo en Inglés | MEDLINE | ID: mdl-25488803

RESUMEN

INTRODUCTION: The activation of the phosphoinositide 3-kinase (PI3K)/AKT signalling pathway is one the most frequent genetic events in breast cancer, consequently the development of PI3K inhibitors has attracted much attention. Here we evaluate the effect of PI3K inhibition on global gene expression in breast cancer cells. METHODS: We used a range of methodologies that include in silico compound analysis, in vitro kinase assays, cell invasion assays, proliferation assays, genome-wide transcription studies (Agilent Technologies full genome arrays), gene set enrichment analysis, quantitative real-time PCR, immunoblotting in addition to chromatin immunoprecipitation. RESULTS: We defined the physico-chemical and the biological properties of ETP-45658, a novel potent PI3K inhibitor. We demonstrated that ETP-45658 potently inhibited cell proliferation within a broad range of human cancer cells, most potently suppressing the growth of breast cancer cells via inhibiting cell cycle. We show that this response is Forkhead box O (FOXO) protein dependent and p53 independent. Our genome-wide microarray analysis revealed that the cell cycle was the most affected biological process after exposure to ETP-45658 (or our control PI3K inhibitor PI-103), that despite the multiple transcription factors that are regulated by the PI3K/AKT signalling cascade, only the binding sites for FOXO transcription factors were significantly enriched and only a subset of all FOXO-dependent genes were induced. This disparity in gene transcription was not due to differential FOXO promoter recruitment. CONCLUSIONS: The constitutive activation of PI3Ks and thus the exclusion of FOXO transcription factors from the nucleus is a key feature of breast cancer. Our results presented here highlight that PI3K inhibition activates specific FOXO-dependent genes that mediate cell cycle arrest in breast cancer cells.


Asunto(s)
Adenocarcinoma , Neoplasias de la Mama , Puntos de Control del Ciclo Celular/efectos de los fármacos , Proliferación Celular/efectos de los fármacos , Factores de Transcripción Forkhead/efectos de los fármacos , Inhibidores de las Quinasa Fosfoinosítidos-3 , Proteínas Proto-Oncogénicas c-akt/efectos de los fármacos , Pirazoles/farmacología , Pirimidinas/farmacología , Línea Celular Tumoral , Simulación por Computador , Femenino , Factores de Transcripción Forkhead/metabolismo , Células HCT116 , Humanos , Técnicas In Vitro , Células MCF-7 , Proteínas Proto-Oncogénicas c-akt/metabolismo , Reacción en Cadena en Tiempo Real de la Polimerasa , Transducción de Señal/efectos de los fármacos
11.
Environ Monit Assess ; 186(11): 7011-21, 2014 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-25074364

RESUMEN

The accumulation of heavy metals in the environment may have a wide range of health effects on animals and humans. Thus, in this study, the concentrations of arsenic (As), cadmium (Cd), lead (Pb), and mercury (Hg) in the blood and tissues (liver and kidney) of Portuguese common buzzards (Buteo buteo) were determined by inductively coupled plasma-mass spectrometer (ICP-MS) in order to monitor environmental pollution to these elements. In general, Hg and As were the elements which appeared in the highest and lowest concentrations, respectively. A highest percentage of non-detected concentration was found for blood Cd (94.6 %) but, in turn, it was the only metal that was detected in all kidney samples. The kidney was the analyzed sample which showed the highest concentrations of each element evaluated. Statistically, significant differences among blood, liver, and kidney samples were observed for As and Cd (P < 0.05). Cd concentrations in kidney and liver varied significantly with age: Adults showed higher hepatic and renal Cd concentrations than juveniles. Blood Pb concentration seems to show an association with the hunting season. Although raptors are at the top of the food chain and are thus potentially exposed to any biomagnification processes that may occur in a food web, the individuals evaluated in this study generally had low levels of heavy metals in blood and tissues. However, chronic exposure to these metals was verified. The results presented here lend weight to arguments in favor of continuous biomonitoring of metals and metalloids, since heavy metals may accumulate to levels that will pose a risk to both human health and the environment.


Asunto(s)
Monitoreo del Ambiente/métodos , Contaminantes Ambientales/metabolismo , Falconiformes/metabolismo , Metales Pesados/metabolismo , Animales , Arsénico/metabolismo , Cadmio/metabolismo , Cadena Alimentaria , Mercurio/metabolismo
12.
Environ Sci Pollut Res Int ; 31(8): 11983-11994, 2024 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-38225500

RESUMEN

The western-European hedgehog (Erinaceus europaeus) is an insectivore with a wide distribution in Portugal and a potential tool for biomonitoring relevant One Health hazards, including heavy metal(loid)s' pollution. The aim of this study was to positively contribute to the current knowledge about the metal(loid) pollution in Portugal. Forty-six hedgehogs (from rescue centres; with known provenance) were necropsied. Sex, age category and weight were determined. Spines, liver and kidney were collected, and metalloid concentrations were determined by inductively coupled plasma mass spectrophotometry (ICP-MS). In general, results did not present alarming metal(loid) concentrations, with the exception of cadmium (Cd) (in the kidneys) and copper (Cu). Hedgehogs from Viana do Castelo and Viseu showed elevated concentrations of arsenic (As) and Castelo Branco presented concerning values of cadmium (Cd). Adult and heavier hedgehogs tended to present higher levels of metal(loid)s. Sex does not seem to significantly affect the metal(loid)s' concentrations. Further analysis would be needed to prioritize areas with detail and allow the application of the necessary mitigation strategies.


Asunto(s)
Metaloides , Metales Pesados , Animales , Cadmio/análisis , Portugal , Erizos , Monitoreo del Ambiente/métodos , Metales Pesados/análisis , Metaloides/análisis , China , Medición de Riesgo
13.
Vet Parasitol Reg Stud Reports ; 43: 100904, 2023 08.
Artículo en Inglés | MEDLINE | ID: mdl-37451760

RESUMEN

Avian haemosporidian (Haemoproteus, Leucocytozoon, Plasmodium) are vector-transmitted protozoan parasites highly prevalent in various bird species. Still, their importance for bird health, species decline, or impact on rehabilitation success is underestimated. This study aimed to determine the occurrence and diversity of haemosporidian parasites after necropsies of seventy wild birds from thirty-four species of twelve taxonomic orders. Detection of avian haemosporidian DNA was evaluated using PCR amplification of the cytochrome b gene. 48.6% of all sampled birds were positive, with 24.3% positive for Plasmodium spp./Haemoproteus spp. and 44.3% for Leucocytozoon spp. Mixed infections corresponded to 20% of all tested birds. Sequencing of several selected samples revealed the infection of Plasmodium matutinum, Plasmodium relictum and different lineages of Leucocytozoon spp. This study provides a baseline description of haemosporidian infections in wild birds from a rehabilitation center in central Portugal. The results show the necessity to test and monitor possible infections that undermine recovery processes for different birds. Further research into the occurrence of these haemosporidian species in birds kept in conservation centers is needed to understand the impact on bird health.


Asunto(s)
Enfermedades de las Aves , Haemosporida , Malaria Aviar , Parásitos , Plasmodium , Animales , Malaria Aviar/epidemiología , Malaria Aviar/parasitología , Animales Salvajes , Enfermedades de las Aves/epidemiología , Enfermedades de las Aves/parasitología , Portugal/epidemiología , ADN Protozoario/genética , Plasmodium/genética , Aves/parasitología , Parásitos/genética , Centros de Rehabilitación
14.
Animals (Basel) ; 13(8)2023 Apr 15.
Artículo en Inglés | MEDLINE | ID: mdl-37106922

RESUMEN

Heavy metal(loid) pollution of ecosystems is a current One Health problem. The liver is one of the most affected organs in cases of acute or chronic exposure to abnormal amounts of these substances, inducing histopathologic lesions. In order to assess the influence of heavy metal(loids), forty-five European hedgehogs (Erinaceus europaeus) were submitted to necropsy, and liver samples were collected for a routine histopathology exam and metal(loid)s determination (As, Cd, Co, Cr, Cu and Pb) by ICP-MS. Age was estimated during the necropsy exam. Biliary hyperplasia was the most frequent lesion observed (16/45; 35.56%). No statistically significant associations were found between biliary hyperplasia and age or sex. Metal(loid)s' concentrations were higher in animals with biliary hyperplasia (except for As). There was a statistically significant difference for both Cd and Co. For As, Cd and Co, cubs and juveniles animals showed significantly lower concentrations than elder individuals. Only for Pb were significant differences found between females and males. As described in the literature, exposure to metal(loid)s may be a cause of biliary hyperplasia, although further research (including the use of biochemical methods) is needed to support these results. To the authors' knowledge, this is the first report of this association in hedgehogs.

15.
Mol Cell Biochem ; 367(1-2): 153-63, 2012 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-22544521

RESUMEN

The aim of this study was to investigate the in vitro antioxidant activity of 2,2'-dipyridyl diselenide (e) by comparing this effect with m-trifluoromethyl-diphenyl diselenide (a), p-fluor-diphenyl diselenide (b), p-chloro-diphenyl diselenide (c), and p-methoxyl-diphenyl diselenide (d) in rat liver homogenate. We also investigated if the mechanisms involved in the antioxidant property of 2,2'-dipyridyl diselenide are the same that of other diselenides. Thiobarbituric acid reactive substances (TBARS) and protein carbonyl (PC) levels were determined in rat liver homogenate, as indicators of antioxidant activity. Dehydroascorbate (DHA) reductase- and glutathione S-transferase (GST)-like activities, 2,2'-diphenyl-1-picrylhydrazyl (DPPH) and 2,2'-azino-bis(3-ethylbenzthiazoline-6-sulfonic acid) (ABTS) radical-scavenging activities and the protection against the oxidation of Fe(2+) were determined to better understand the antioxidant property of compounds. δ-Aminolevulinic dehydratase (δ-ALA-D) activity was also carried out in rat liver homogenates, as a toxicological parameter. Compound e showed the highest potency in reducing TBARS (order of IC(50) values: e < b ≤ a < d ≤ c) and PC (order of IC(50) values: e < c ≤ b ≤ a < d) levels and lower potency in inhibiting δ-ALA-D activity than other diselenides. Compound e at all concentrations tested had no enzyme-mimetic property, but had radical-scavenging activity (≥5 µM) and protected against the oxidation of Fe(2+) (50 µM); while compounds a-d showed GST and DHA-mimetic activities and protected against the oxidation of Fe(2+), but had not radical-scavenging activities. This study indicates that (i) 2,2'-dipyridyl diselenide (e) had better in vitro antioxidant effect than other diselenides and lower inhibitory effect on δ-ALA-D activity, (ii) the presence of pyridine ring is responsible for the best antioxidant effect of this compound, and (iii) 2,2'-dipyridyl diselenide acts by different mechanisms of other diselenides.


Asunto(s)
2,2'-Dipiridil/análogos & derivados , Antioxidantes/farmacología , Compuestos de Organoselenio/farmacología , 2,2'-Dipiridil/química , 2,2'-Dipiridil/farmacología , Animales , Antioxidantes/química , Ácido Ascórbico/química , Derivados del Benceno/química , Derivados del Benceno/farmacología , Ácido Deshidroascórbico/química , Compuestos Ferrosos/química , Glutatión/química , Glutatión Transferasa/química , Peroxidación de Lípido , Hígado/efectos de los fármacos , Hígado/enzimología , Masculino , Compuestos de Organoselenio/química , Compuestos de Organosilicio/química , Compuestos de Organosilicio/farmacología , Oxidación-Reducción , Oxidorreductasas/química , Porfobilinógeno Sintasa/antagonistas & inhibidores , Porfobilinógeno Sintasa/metabolismo , Carbonilación Proteica , Ratas , Ratas Wistar , Sustancias Reactivas al Ácido Tiobarbitúrico/metabolismo , Extractos de Tejidos
16.
J Chem Neuroanat ; 119: 102059, 2022 01.
Artículo en Inglés | MEDLINE | ID: mdl-34896559

RESUMEN

The neuroprotective effect of Edaravone in young hydrocephalic rats associated with a CSF derivation system was evaluated. The drug has already been shown to be beneficial in experimental hydrocephalus, but the combination of this drug with shunt surgery has not yet been investigated. Fifty-seven-day-old Wistar rats submitted to hydrocephalus by injection of kaolin in the cisterna magna were used and divided into five groups: control (n = 10), hydrocephalic (n = 10), hydrocephalic treated with Edaravone (20 mg/kg/day) (n = 10), hydrocephalic treated with shunt (n = 10) and hydrocephalic treated with shunt and Edaravone (n = 10). Administration of the Edaravone was started 24 h after hydrocephalus induction (P1) and continued until the experimental endpoint (P21). The CSF shunt surgery was performed seven days after hydrocephalus induction (P7). Open-field tests, histological evaluation by hematoxylin and eosin, immunohistochemistry by Caspase-3 and GFAP, and ELISA biochemistry by GFAP were performed. Edaravone reduced reactive astrogliosis in the corpus callosum and germinal matrix (p < 0.05). When used alone or associated with CSF shunt surgery, the drug decreased the cell death process (p < 0.0001) and improved the morphological aspect of the astroglia (p < 0.05). The results showed that Edaravone associated with CSF bypass surgery promotes neuroprotection in young hydrocephalic rats by reducing reactive astrogliosis and decreasing cell death.


Asunto(s)
Astrocitos , Neuroprotección , Animales , Apoptosis , Astrocitos/metabolismo , Edaravona/metabolismo , Edaravona/farmacología , Ratas , Ratas Wistar
17.
J Appl Toxicol ; 31(8): 773-82, 2011 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-21259295

RESUMEN

Following our long-standing interest in the mechanisms involved in selenium toxicity, the aim of this work was to extend our previous studies to gain a better understanding of mercuric chloride (HgCl2) + diphenyl diselenide (PhSe)2 toxicity. Mice received one daily dose of HgCl2 (4.6 mg kg(-1) , subcutaneously) for three consecutive days. Thirty minutes after the last injection of HgCl2, mice received a single dose of (PhSe)2 (31.2 mg kg(-1) , subcutaneously). Five hours after (PhSe)2 administration, mice were euthanized and δ-aminolevulinate dehydratase, catalase (CAT), glutathione S-transferase (GST) and Na(+) , K(+) -ATPase activities as well as thiobarbituric acid-reactive substances (TBARS), ascorbic acid and mercury levels were determined in kidney and liver. Parameters in plasma (urea, creatinine, protein and erythropoietin), whole blood (hematocrit and hemoglobin) and urine (protein) were also investigated. HgCl2 + (PhSe)2 exposure caused a decrease in renal GST and Na(+) , K(+) -ATPase activities and an increase in renal ascorbic acid and TBARS concentrations when compared with the HgCl2 group. (PhSe)2 potentiated the increase in plasma urea caused by HgCl2. HgCl2 + (PhSe)2 exposure caused a reduction in plasma protein levels and an increase in hemoglobin and hematocrit contents when compared with the HgCl2 group. There was a significant reduction in hepatic CAT activity and an increase in TBARS levels in mice exposed to HgCl2 + (PhSe)2 when compared with the HgCl2 group. The results demonstrated that (PhSe)2 did not modify mercury levels in mice. In conclusion, (PhSe)2 potentiated damage caused by HgCl2 affecting mainly the renal tissue.


Asunto(s)
Lesión Renal Aguda/patología , Derivados del Benceno/toxicidad , Riñón/efectos de los fármacos , Cloruro de Mercurio/toxicidad , Compuestos de Organoselenio/toxicidad , Lesión Renal Aguda/inducido químicamente , Animales , Ácido Ascórbico/metabolismo , Catalasa/metabolismo , Creatinina/sangre , Eritropoyetina/sangre , Glutatión Transferasa/metabolismo , Riñón/metabolismo , Hígado/efectos de los fármacos , Hígado/metabolismo , Masculino , Mercurio/análisis , Ratones , Estrés Oxidativo/efectos de los fármacos , Porfobilinógeno Sintasa/metabolismo , Sustancias Reactivas al Ácido Tiobarbitúrico/metabolismo , Urea/sangre
18.
Pathogens ; 10(9)2021 Sep 05.
Artículo en Inglés | MEDLINE | ID: mdl-34578176

RESUMEN

Toxoplasma gondii is a worldwide zoonotic parasite. According to the "One Health" approach, studies on toxoplasmosis are essential since it affects humans and domestic and wild animals. In the present study, antibodies to T. gondii were determined in serum samples from 263 wild birds located in five wildlife rehabilitation centres in mainland Portugal by using the modified agglutination test (MAT) with a cut-off titre of 20. An overall seroprevalence of 36.5% (95% confidence interval [CI]: 30.7-42.6) was observed. For the first time, antibodies to T. gondii were detected in some avian species, including pallid swift (Apus pallidus) (33.3%), black-backed gull (Larus fuscus) (39.3%), European turtle-dove (Streptopelia turtur) (100%), bee-eater (Merops apiaster) (50.0%), carrion crow (Corvus corone) (33.3%), and Egyptian vulture (Neophron percnopterus) (100%), which expands the list of intermediate hosts of T. gondii. A lower seroprevalence was found in juvenile birds (31.9%) compared to adults (48.7%) (p = 0.016). The central region of Portugal was considered a risk factor for T. gondii infection in wild birds (odds ratio: 3.61; 95% CI: 1.09-11.91). This pioneer study calls attention to the need for further studies, to provide a clearer understanding of T. gondii epidemiology in Portugal, because it reflects wide dispersion of T. gondii oocysts in the environment.

19.
Arch Environ Occup Health ; 76(3): 152-162, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-32614680

RESUMEN

Workers exposed to fuels and paints may present alterations in several parameters. Thus, we assessed potential biomarkers, with the aim of detecting early changes in gasoline station attendants and painters. Blood samples were collected for the analysis of inflammatory and DNA damage markers, besides biochemical, haematological and oxidative stress parameters. Biochemical and haematological parameters, which are assessed with routine exams, showed few changes. However, these findings could mask the workers' real health status. Besides, markers of oxidative damage were not modified. Levels of inflammatory parameters (cytokines and nitric oxide levels) and the DNA damage marker 8-hydroxydeoxyguanosine were significantly changed in the workers. Our results suggest that inflammatory and DNA damage parameters can be potential biomarkers for the biological monitoring of workers exposed to fuels and paints and may contribute to the development of occupational protection standards.


Asunto(s)
Daño del ADN , Aceites Combustibles/efectos adversos , Inflamación/etiología , Exposición Profesional/efectos adversos , Pintura/efectos adversos , Adulto , Biomarcadores/sangre , Brasil/epidemiología , Humanos , Inflamación/sangre , Masculino , Estrés Oxidativo , Lugar de Trabajo
20.
Appl Environ Microbiol ; 76(12): 4118-20, 2010 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-20418435

RESUMEN

Extended-spectrum beta-lactamase-containing Escherichia coli isolates were detected in 32 of 119 fecal samples (26.9%) from birds of prey at Serra da Estrela, and these isolates contained the following beta-lactamases: CTX-M-1 (n = 13), CTX-M-1 plus TEM-1 (n = 14), CTX-M-1 plus TEM-20 (n = 1), SHV-5 (n = 1), SHV-5 plus TEM-1 (n = 2), and TEM-20 (n = 1).


Asunto(s)
Enfermedades de las Aves/microbiología , Infecciones por Escherichia coli/veterinaria , Proteínas de Escherichia coli/genética , Escherichia coli/enzimología , beta-Lactamasas/genética , Animales , Escherichia coli/genética , Escherichia coli/aislamiento & purificación , Infecciones por Escherichia coli/microbiología , Heces/microbiología , Portugal , Rapaces
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