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1.
Geophys Res Lett ; 49(15): e2022GL097795, 2022 Aug 16.
Artículo en Inglés | MEDLINE | ID: mdl-36247518

RESUMEN

Seismic radial anisotropy (the squared ratio between the speeds of horizontally and vertically polarized shear waves, ξ = V S H 2 V S V 2 ) is a powerful tool to probe the direction of mantle flow and accumulated strain. While previous studies have confirmed the dependence of azimuthal anisotropy on plate speed, the first order control on radial anisotropy is unclear. In this study, we develop 2D ridge flow models combined with mantle fabric calculations to report that faster plates generate higher tectonics stresses and strain rates which lower the dislocation creep viscosity and lead to deeper anisotropy than beneath slower plates. We apply the SGLOBE-rani tomographic filter, resulting in a flat depth-age trend and stronger anisotropy beneath faster plates, which correlates well with 3D global anisotropic mantle models. Our predictions and observations suggest that as plate speed increases from 2 to 8 cm/yr, radial anisotropy increases by ∼0.01-0.025 in the upper 100-200 km of the mantle between 10 and 60 Ma.

2.
Microb Pathog ; 142: 104030, 2020 Feb 03.
Artículo en Inglés | MEDLINE | ID: mdl-32027974

RESUMEN

Leptospira infection is influenced by the host species and the bacterial strain involved. Important differences on their tissue distribution are referred, also depending on the host and the studied strain. Considering tissue distribution of leptospires the majority of the studies focus on a single strain, or strains from the same serogroup with different inoculation doses. Nevertheless, none had associated different serogroups with their tissue distribution. Thus, the present study aims to investigate the hypothesis that tissue distribution of Leptospira spp. on experimentally infected hamsters may vary according to the strain serogroup. Females of Golden Syrian hamsters were used for the experimental infection with Leptospira isolates (n = 13) belonging to serogroups Icterohaemorrhagiae (n = 8) and Sejroe (n = 5). PCRs were conducted in renal, hepatic and uterine tissue. Seven out of the thirteen studied hamsters presented acute clinical signs and were euthanized before the 21° day p.i. (strains VF237, VF52, U81, UFF-SG001, UFF-G19, UFF-B15, L1-130), while the others presented a subclinical infection. Regarding to the PCR results it was possible to observe that, all but one strain (UFF-SG001), which was detected on all the studied tissues, presented some differences on their tissue distribution. All strains could be detected on at least one tissue and a significant association was observed for the occurrence of the strains of serogroup Sejroe in uterus (p = 0.044). The results of the present study indicate that strains of serogroup Sejroe are strongly associated to uterine infection on experimentally infected hamsters.

3.
Parasite Immunol ; 38(3): 193-205, 2016 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-26425838

RESUMEN

Cystic echinococcosis is the infection by the larvae of cestode parasites belonging to the Echinococcus granulosus sensu lato species complex. Local host responses are strikingly subdued in relation to the size and persistence of these larvae, which develop within mammalian organs as 'hydatid cysts' measuring up to tens of cm in diameter. In a context in which helminth-derived immune-suppressive, as well as Th2-inducing, molecules garner much interest, knowledge on the interactions between E. granulosus molecules and the immune system lags behind. Here, we discuss what is known and what are the open questions on E. granulosus molecules and structures interacting with the innate and adaptive immune systems, potentially or in demonstrated form. We attempt a global biological approach on molecules that have been given consideration primarily as protective (Eg95) or diagnostic antigens (antigen B, antigen 5). We integrate glycobiological information, which traverses the discussions on antigen 5, the mucin-based protective laminated layer and immunologically active preparations from protoscoleces. We also highlight some less well-known molecules that appear as promising candidates to possess immune-regulatory activities. Finally, we point out gaps in the molecular-level knowledge of this infectious agent that hinder our understanding of its immunology.


Asunto(s)
Antígenos Helmínticos/inmunología , Equinococosis/inmunología , Echinococcus granulosus/inmunología , Glicoproteínas/inmunología , Proteínas del Helminto/inmunología , Larva/inmunología , Lipoproteínas/inmunología , Animales , Equinococosis/parasitología , Equinococosis/patología , Células Th2/inmunología
4.
Oral Dis ; 22(6): 536-42, 2016 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-27090966

RESUMEN

OBJECTIVES: To determine the prevalence of oral potentially malignant disorders (OPMDs) in a population of rural workers in the northeast of Brazil and to investigate the association with sociodemographic, occupational, and health factors. METHODS: A total of 1385 workers answered a validated questionnaire and were examined by calibrated dentists. A descriptive analysis, chi-square homogeneity test, and binary logistic regression were performed. RESULTS: The prevalence of OPMDs was 29.6%. Actinic cheilitis was the most predominant (28.4%), followed by leukoplakia (2.3%) and erythroplakia (0.3%). Gender, type of skin, and time exposed to the sun explained the presence of OPMD (P < 0.0001). The study found increased prevalence, especially for males over the age of 60 years and being exposed to the sun for more than 45 years. CONCLUSION: Rural workers showed high vulnerability to the presence of OPMDs, as estimated prevalence exhibited was high.


Asunto(s)
Neoplasias de la Boca/epidemiología , Población Rural , Adolescente , Adulto , Anciano , Brasil/epidemiología , Queilitis/epidemiología , Estudios Transversales , Eritroplasia/epidemiología , Femenino , Humanos , Leucoplasia Bucal/epidemiología , Masculino , Persona de Mediana Edad , Neoplasias de la Boca/etiología , Prevalencia
5.
J Equine Vet Sci ; 132: 104984, 2024 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-38081332

RESUMEN

Asinina de Miranda is a protected donkey sub-species from the Mirandês plateau in northeastern of Portugal. Donkeys are animals that have substantially lost their place as working animals in modern society, this had led to a decrease in their population numbers. A need to preserve native species has led to the foundation of organizations like Associação para o Estudo e Proteção do Gado Asinino (AEPGA) and the development of studies regarding breed welfare, such as hematology. The IDEXX ProCyte Dx is a veterinary hematology analyzer validated for several species, but not for donkeys. The aim of this study was to validate the ProCyte Dx for Asinina de Miranda donkeys. The validation requires a controlled study of precision, carryover, linearity and comparison between the equipment and the manually obtained values for the leukocyte differential count and hematocrit. Results indicated coefficient of variation was good (below 5 %) for both the intra-assay and the inter-assay precision, except for basophils. Carryover was 0 % for all the parameters except platelets (5.88 %). Linearity showed a very high Pearson correlation coefficient, above 0.99, for erythrocytes, hematocrit, hemoglobin, leucocytes, neutrophils, lymphocytes, monocytes, eosinophils, platelets and plateletcrit. Comparison demonstrated excellent agreement for hematocrit (rs=0.96) and good Spearman rank correlation for neutrophils (rs=0.84) and lymphocytes (rs=0.90). Accuracy for total leukocyte count and platelets could not be determined. In conclusion, the ProCyte Dx seems appropriate to be used in Asinina de Miranda hematology.


Asunto(s)
Equidae , Hematología , Animales , Recuento de Células Sanguíneas/métodos , Recuento de Células Sanguíneas/veterinaria , Reproducibilidad de los Resultados , Recuento de Leucocitos/veterinaria , Hematología/métodos
7.
Fish Shellfish Immunol Rep ; 5: 100121, 2023 Dec 15.
Artículo en Inglés | MEDLINE | ID: mdl-37964807

RESUMEN

Chronic stress deteriorates the immune function of fish, thereby increasing their vulnerability to infections. However, the molecular and cellular mechanisms underlying stress-mediated immunosuppression and infection susceptibility in fish remain largely unknown. Understanding these mechanisms will contribute to improving fish welfare and their farm production. Herein, we review the challenges of sturgeon aquaculture in subtropical countries, where current climate change has giving rise to significant temperature increments during summer. This leads to the exposure of fish to stressful conditions during these months. Chronic heat stress deserves attention considering the rapid warming rate of the planet. It is already affecting wild fish populations, with disastrous consequences for sturgeons, which are one of the most endangered fish species in the world. In this context, we discuss the most recent advances through the studies on the effects of chronic heat stress on the innate immune components of sturgeons. To this end, we summarise the findings of studies focusing on the aquaculture of Russian sturgeons and observations made on other Acipenser species. Special attention is given to acute-phase proteins, as they might be valuable biomarkers of heat stress and infection, with applicability in monitoring the fish health status in farms.

8.
Ecotoxicology ; 21(3): 730-49, 2012 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-22143384

RESUMEN

Mussels Mytilus galloprovincialis were cross-transplanted at South Portugal from a reference site (site 1) to a site more contaminated with hydrocarbon compounds (site 2), and vice versa, in an active biomonitoring (ABM) concept, to assess the biotransformation capacity catalyzed by the mixed function oxygenase (MFO) system. Total alkanes (TAlk), the unresolved complex mixture (UCM), and total polycyclic aromatic hydrocarbons (TPAHs) concentration increased respectively 6, 4.4 and 4.2 fold relatively to control, in mussels transplanted from site 1 to 2. In the cross-transplant, a 48, 57 and 62% depuration of TAlk, UCM and TPAHs concentrations occurred by the end of the 3-4th week. Petrogenic and biogenic (marine and terrigenous) sources of AHs, and petrogenic and pyrolitic (biomass and oil/fuel incomplete combustion) sources of PAHs were detected at both sites. CYP450, CYT b (5) and NADPH-RED in mussels transplanted from site 1 to 2 were induced from day 0 to 28, with a total increase of 35, 32 and 35%, respectively, while biochemical equilibrium to lesser environmental contamination occurs in mussels transplanted from site 2 to 1. A significant relationship between CYP450 and NADPH-RED was found with TPAH, with distinctive behavior at the two sites. MFO system components increase with exposure time at one site and decreases in the other, reflecting an adaptation to distinct environmental hydrocarbon loads. The ABM strategy proved to be useful to understand the environment real impact on the biochemical responses in mussels' local populations. In this study, CYP450 and NADPH-RED are a useful biomarker for hydrocarbon exposure.


Asunto(s)
Sistema Enzimático del Citocromo P-450/efectos de los fármacos , Hidrocarburos Alicíclicos/toxicidad , Mytilus/fisiología , Hidrocarburos Policíclicos Aromáticos/toxicidad , Contaminantes Químicos del Agua/toxicidad , Animales , Biomarcadores/metabolismo , Biotransformación , Carga Corporal (Radioterapia) , Sistema Enzimático del Citocromo P-450/metabolismo , Citocromos b5/efectos de los fármacos , Citocromos b5/metabolismo , Monitoreo del Ambiente , Hidrocarburos Alicíclicos/farmacocinética , NADPH Oxidasas/efectos de los fármacos , NADPH Oxidasas/metabolismo , Hidrocarburos Policíclicos Aromáticos/farmacocinética , Portugal , Agua de Mar , Contaminantes Químicos del Agua/farmacocinética
9.
Carbohydr Polym ; 90(1): 34-40, 2012 Sep 01.
Artículo en Inglés | MEDLINE | ID: mdl-24751007

RESUMEN

Ethylene-vinyl acetate copolymer (EVA) with 19% of vinyl acetate and its derivatives modified by hydrolysis of 50 and 100% of the initial vinyl acetate groups were used to produce blends with thermoplastic starch (TPS) plasticized with 30 wt% glycerol. The blends were characterized by Fourier transform infrared spectroscopy, scanning electron microscopy, X-ray diffraction, water absorption, stress-strain mechanical tests, dynamic mechanical analysis and thermogravimetric analysis. In contrast to the blends with unmodified EVA, those made with hydrolyzed EVA were compatible, as demonstrated by the brittle fracture surface analysis and the results of thermal and mechanical tests. The mechanical characteristics and water absorption of the TPS were improved even with a small addition (2.5 wt%) of hydrolyzed EVA. The glass transition temperature rose with the degree of hydrolysis of EVA by 40 and 50°, for the EVA with 50 and 100% hydrolysis, respectively. The addition of hydrolyzed EVA proved to be an interesting approach to improving TPS properties, even when very small quantities were used, such as 2.5 wt%.

10.
Vet Parasitol Reg Stud Reports ; 29: 100688, 2022 04.
Artículo en Inglés | MEDLINE | ID: mdl-35256116

RESUMEN

Toxoplasma gondii infects warm-blooded animals, including humans, and the ingestion of undercooked meat of infected animals is an important source of infection. We investigated the presence of T. gondii by PCR and histopathology in tissues of 25 seropositive sheep slaughtered for human consumption in Rio de Janeiro and assessed the suitability of different tissues for molecular detection of the parasite. The animals were first screened for T. gondii antibodies by MAT (Modified Agglutination Test), and tissues of seropositive sheep (brain, heart, lungs, kidneys, liver and diaphragm) were subjected to molecular and histological examination. A nested-PCR targeting the P43 gene of T. gondii was performed, and kappa Coefficient was used to assess PCR results among tissues. DNA of the parasite was detected in 60 % (9 of 15) of the animals. and tissue pairs of lungs/heart, lungs/diaphragm or heart/diaphragm had substantial agreement with the global status of the animals. The combination between these three tissues leads to an almost perfect agreement with global status results. Sheep slaughtered for human consumption in Rio de Janeiro, Brazil are infected with T. gondii, and pairs of fragments of lungs and heart, lungs and diaphragm or heart and diaphragm could be used for molecular identification of T. gondii in sheep with substantial agreement with the global status of the animals.


Asunto(s)
Toxoplasma , Toxoplasmosis Animal , Animales , Animales Domésticos , Anticuerpos Antiprotozoarios , Brasil/epidemiología , Humanos , Ovinos , Toxoplasma/genética , Toxoplasmosis Animal/parasitología
11.
Natl Med J India ; 24(1): 16-8, 2011.
Artículo en Inglés | MEDLINE | ID: mdl-21608352

RESUMEN

BACKGROUND: We aimed to estimate the prevalence of diabetes mellitus and study the associated factors in a rural population in Goa, India. METHODS: A cross-sectional study was done in the rural area of Mandur, Goa. Participants>20 years of age were selected by systematic random sampling. They were interviewed with the help of a structured, pretested questionnaire. This was followed by clinical examination, anthropometry and relevant laboratory investigations. Diabetes mellitus was defined as per the American Diabetes Association (ADA) criteria. Statistical analysis was done using the SPSS software package (version 14.0). RESULTS: The prevalence of diabetes mellitus in the study population was 10.3% (130/1266) with a prevalence of 8.4% among men and 12% among women. On bivariate analysis, the prevalence of diabetes mellitus was found to be significantly associated with age, occupation, family income, family history of diabetes, smoking, obesity, hypertension, and high serum cholesterol and triglycerides levels. Multiple logistic regression analysis identified age, family history, hypertension, smoking, total cholesterol and triglyceride as the Independently associated variables for diabetes mellitus. CONCLUSION: Innovative community outreach programmes are required to create awareness, and for screening and treatment of diabetes mellitus to curb the growing epidemic of diabetes in the population.


Asunto(s)
Diabetes Mellitus/epidemiología , Población Rural/estadística & datos numéricos , Adulto , Anciano , Anciano de 80 o más Años , Estudios Transversales , Femenino , Humanos , India/epidemiología , Masculino , Persona de Mediana Edad , Prevalencia , Factores de Riesgo , Adulto Joven
12.
Reumatismo ; 63(3): 171-4, 2011 Nov 09.
Artículo en Inglés | MEDLINE | ID: mdl-22257918

RESUMEN

We present a rare case of splenic tuberculosis in a 42-year old man with long-standing ankylosing spondylitis treated with adalimumab. We review the association between antitumor necrosis factor therapy and splenic tuberculosis. Our case, like many other reported cases, illustrates that the index of suspicion of tuberculosis in patients treated with anti TNF therapies must be high and emphasizes that this rare infection may occur even with negative tuberculosis screening before the initiation of therapy.


Asunto(s)
Anticuerpos Monoclonales Humanizados/efectos adversos , Antirreumáticos/efectos adversos , Inmunosupresores/efectos adversos , Infecciones Oportunistas/etiología , Espondilitis Anquilosante/tratamiento farmacológico , Tuberculosis Esplénica/etiología , Adalimumab , Adulto , Quimioterapia Combinada , Humanos , Huésped Inmunocomprometido , Masculino , Metotrexato/uso terapéutico , Infecciones Oportunistas/diagnóstico , Espondilitis Anquilosante/complicaciones , Tomografía Computarizada por Rayos X , Tuberculosis Pulmonar/diagnóstico , Tuberculosis Pulmonar/etiología , Tuberculosis Esplénica/diagnóstico , Factor de Necrosis Tumoral alfa/antagonistas & inhibidores
13.
Nat Commun ; 12(1): 7307, 2021 Dec 15.
Artículo en Inglés | MEDLINE | ID: mdl-34911961

RESUMEN

The flow of the Greenland Ice Sheet is controlled by subglacial processes and conditions that depend on the geological provenance and temperature of the crust beneath it, neither of which are adequately known. Here we present a seismic velocity model of the uppermost 5 km of the Greenlandic crust. We show that slow velocities in the upper crust tend to be associated with major outlet glaciers along the ice-sheet margin, and elevated geothermal heat flux along the Iceland hotspot track inland. Outlet glaciers particularly susceptible to basal slip over deformable subglacial sediments include Jakobshavn, Helheim and Kangerdlussuaq, while geothermal warming and softening of basal ice may affect the onset of faster ice flow at Petermann Glacier and the Northeast Greenland Ice Stream. Interactions with the solid earth therefore control the past, present and future dynamics of the Greenland Ice Sheet and must be adequately explored and implemented in ice sheet models.

14.
Psychoneuroendocrinology ; 129: 105268, 2021 07.
Artículo en Inglés | MEDLINE | ID: mdl-34023733

RESUMEN

This is a systematic review about the association between empathic behavior and oxytocin (OXT). Searches were conducted in the electronic databases PubMed, Web of Science, PsycINFO, SciELO, and LILACS using the search terms "oxytocin", "empathy", and "empathic". Forty-four studies were reviewed. Scarce findings point to a lack of association between baseline endogenous OXT levels and empathy traits, and for a trend towards a direct relationship between oxytocinergic reactivity and empathic functioning. The results showed that variations in empathy were related to polymorphisms in the OXT receptor gene, especially in rs53576, and that this relationship seems to mediated by individual, ethnic, and cultural characteristics. Most studies on the exogenous administration of OXT tested a single dose (24 IU) with positive effects mainly on the affective domain of empathy. At the neural level, findings were inconsistent. Taken together, the results of the studies reviewed support the existence of a relationship between OXT and empathy that is complex and multifaceted. Robust evidence is still needed to elucidate existing links. Future investigations could benefit from methodological improvements aimed at increasing the reproducibility and applicability of findings, as well as the systematic assessment of the effects of exogenous OXT considering dose and frequency of administration, genotyping, and hormonal availability at the peripheral and central levels. This should lead to significant progress in the understanding of the therapeutic possibilities of OXT in the domain of empathic behavior.


Asunto(s)
Empatía , Oxitocina , Empatía/fisiología , Humanos
15.
Redox Biol ; 29: 101376, 2020 01.
Artículo en Inglés | MEDLINE | ID: mdl-31926616

RESUMEN

Nitro-fatty acids (NO2-FA) are electrophilic lipid mediators derived from unsaturated fatty acid nitration. These species are produced endogenously by metabolic and inflammatory reactions and mediate anti-oxidative and anti-inflammatory responses. NO2-FA have been postulated as partial agonists of the Peroxisome Proliferator-Activated Receptor gamma (PPARγ), which is predominantly expressed in adipocytes and myeloid cells. Herein, we explored molecular and cellular events associated with PPARγ activation by NO2-FA in monocytes and macrophages. NO2-FA induced the expression of two PPARγ reporter genes, Fatty Acid Binding Protein 4 (FABP4) and the scavenger receptor CD36, at early stages of monocyte differentiation into macrophages. These responses were inhibited by the specific PPARγ inhibitor GW9662. Attenuated NO2-FA effects on PPARγ signaling were observed once cells were differentiated into macrophages, with a significant but lower FABP4 upregulation, and no induction of CD36. Using in vitro and in silico approaches, we demonstrated that NO2-FA bind to FABP4. Furthermore, the inhibition of monocyte FA binding by FABP4 diminished NO2-FA-induced upregulation of reporter genes that are transcriptionally regulated by PPARγ, Keap1/Nrf2 and HSF1, indicating that FABP4 inhibition mitigates NO2-FA signaling actions. Overall, our results affirm that NO2-FA activate PPARγ in monocytes and upregulate FABP4 expression, thus promoting a positive amplification loop for the downstream signaling actions of this mediator.


Asunto(s)
Monocitos , PPAR gamma , Proteínas de Unión a Ácidos Grasos/genética , Ácidos Grasos , Humanos , Proteína 1 Asociada A ECH Tipo Kelch , Monocitos/metabolismo , Factor 2 Relacionado con NF-E2 , PPAR gamma/genética , PPAR gamma/metabolismo
16.
Vet J ; 248: 58-63, 2019 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-31113564

RESUMEN

The ABCB1 gene encodes the P-glycoprotein (P-gp) which regulates distribution and bioavailability of many endogenous and exogenous substrates, acting as a cellular mechanism of protection against these substances. Some studies have shown evidence that P-gp is related to carcinogenesis. In this study, we performed PCR and direct sequencing of ABCB1 exons 9 and 26 in 47 tissue DNA samples from canine mammary tumors. A statistically significant correlation between distinct canine breeds and the frequency of ABCB1 polymorphisms (c.985T > A and c.3442A > G SNP in ABCB1exons 9 and 26, respectively) was observed (P = 0.0015). In contrast, the TNM clinical staging, age, histological type and grade, as well as other histopathological characteristics, did not present statistically significant difference in relation to one or both SNP found in exons 9 and 26. These findings raise questions about the role of the canine ABCB1 polymorphisms in the development of mammary tumors, since the Poodle breed, which is the most common dog breed affected by mammary tumors in Brazil, presented the highest frequency of these variants. Notwithstanding, additional studies comprising a number of samples expressing the ABCB1 gene from healthy dogs, with advanced age and from different breeds, will be necessary to confirm the association of ABCB1polymorphisms and the development of mammary tumors.


Asunto(s)
Miembro 1 de la Subfamilia B de Casetes de Unión a ATP/genética , Enfermedades de los Perros/genética , Predisposición Genética a la Enfermedad , Neoplasias Mamarias Animales/genética , Animales , Perros , Femenino , Linaje , Reacción en Cadena de la Polimerasa/veterinaria , Polimorfismo de Nucleótido Simple , Factores de Riesgo
17.
Oncogene ; 26(2): 308-11, 2007 Jan 11.
Artículo en Inglés | MEDLINE | ID: mdl-16819508

RESUMEN

The EPH/EFN family of receptor tyrosine kinases regulates cell adhesion and migration and has an important role in controlling cell positioning in the normal intestinal epithelium. Inactivation of EPHB2 has recently been shown to accelerate tumorigenesis in the colon and rectum, and we have previously demonstrated frequent frameshift mutations (41%) in an A9 coding microsatellite repeat in exon 17 of EPHB2 in colorectal tumors with microsatellite instability (MSI). In this study, we extended these analyses to extracolonic MSI cancers, and found frameshift EPHB2 mutations in 39% (25/64) of gastric tumors and 14% (8/56) of endometrial tumors. Regression analysis of these EPHB2 mutation data on the basis of our previously proposed statistical model identified EPHB2 as a selective target of frameshift mutations in MSI gastric cancers but not in MSI endometrial carcinomas. These results suggest a functional role for EPHB2 in gastric tumor progression, and emphasize the differences between the tumorigenic processes in MSI gastrointestinal and endometrial cancer.


Asunto(s)
Neoplasias Endometriales/genética , Mutación del Sistema de Lectura/genética , Inestabilidad de Microsatélites , Receptor EphB2/genética , Neoplasias Gástricas/genética , Análisis Mutacional de ADN , ADN de Neoplasias/análisis , Femenino , Humanos , Repeticiones de Microsatélite , Reacción en Cadena de la Polimerasa , Polimorfismo Conformacional Retorcido-Simple
18.
Parasite Immunol ; 30(6-7): 354-64, 2008.
Artículo en Inglés | MEDLINE | ID: mdl-18444958

RESUMEN

The larva of the cestode Echinococcus granulosus (hydatid cyst) is protected by the acellular laminated layer (LL). The mechanisms that make this thick coat a poor activator of host complement are incompletely understood. The structure binds, through unknown motifs, the host regulator of the alternative complement pathway (ACP), factor H. A second potential mechanism of ACP regulation, the inhibition of factor B activation, was detected in assays employing purified components (Immunopharmacology 42 : 91). The inhibitor was subsequently identified as myo-inositol hexakisphosphate (InsP(6)), which in the form of nano-deposits is a major component of the LL (Biochem J 362 : 297; J Cell Biochem 93 : 1272; FEBS J 273 : 3192). In this report we show that colloidal InsP(6 )solids inhibit factor B activation, through adsorption and associated impairment of C3b binding. However, this interaction is not relevant in the presence of serum proteins. In serum, InsP(6) deposits instead bind C1q, and initiate complement activation. This activation is curtailed through efficient C3b inactivation, previously shown to be entirely factor H-dependent, and now observed to be independent of the InsP(6) deposits. Therefore the complement resistance of the LL must be based on functional factor H binding sites present on the mucin-based meshwork that is its other major constituent.


Asunto(s)
Vía Alternativa del Complemento , Equinococosis/inmunología , Echinococcus granulosus/inmunología , Ácido Fítico/inmunología , Animales , Complemento C1q/inmunología , Complemento C1q/metabolismo , Complemento C3b/inmunología , Factor B del Complemento/antagonistas & inhibidores , Factor H de Complemento/inmunología , Humanos , Ácido Fítico/metabolismo
19.
Environ Int ; 34(1): 94-101, 2008 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-17719633

RESUMEN

The contamination of aquatic ecosystems by organic contaminants such as polycyclic aromatic hydrocarbons (PAHs) is a matter of great concern. Mussels have been extensively used as sentinel species in a large number of monitoring programs. However, the use of bivalves as the sole species has some limitations, because they are not as responsive as fish to Aryl Hydrocarbon Receptor agonists. Hence, for many marine areas, there is the need to validate new sentinel fish species that can be used in the assessment of pollution by organic contaminants. The shanny Lipophrys pholis is an intertidal fish that combines many characteristics required in a sentinel species: is abundant and easy to catch, has a wide geographical distribution and restrict home range. After larvae recruitment to the intertidal rocky shores, they remain in the same area for the rest of the life-cycle, thus reflecting local pollutants exposure. In order to evaluate the species sensitivity to organic contaminants under field conditions, L. pholis were collected at six sites reflecting different degrees of anthropogenic contamination. The induction of two biomarkers extensively validated in the assessment of PAHs contamination ethoxyresorufin-O-deethylase activity (EROD) and Fluorescent Aromatic Compounds (FACs) was evaluated. In parallel, mussels were collected at the same locations and levels of 16 PAHs and selected heavy metals determined. Overall, the specimens collected in the urban areas showed a significant induction of EROD and FACs (up to a six-fold induction) if compared with the reference sites. Additionally, a positive correlation was observed between the biomarkers and PAHs levels in mussel tissues. Even though further validation is currently in progress, the available data indicate that L. pholis is responsive to organic contaminants such as PAHs, suggesting its future integration in monitoring programmes designed to evaluate the presence of these contaminants in European marine ecosystems.


Asunto(s)
Monitoreo del Ambiente/métodos , Perciformes/fisiología , Hidrocarburos Policíclicos Aromáticos/análisis , Hidrocarburos Policíclicos Aromáticos/toxicidad , Vigilancia de Guardia , Contaminación Química del Agua/análisis , Animales , Bivalvos/química , Citocromo P-450 CYP1A1/metabolismo , Europa (Continente) , Fluorescencia , Metales Pesados/análisis , Agua de Mar/química
20.
Chemosphere ; 70(10): 1756-65, 2008 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-17942140

RESUMEN

This paper presents the results of investigations on the suitability of lugworms (Arenicola marina) to study the bioaccumulation potential of Hg, PCB and PAH compounds from dredged sediments upon laboratory exposure. The results of tissue concentrations for several sediments from Spanish ports showed that it is possible to identify increased levels of contaminants in lugworms just after 10 days of exposure although different bioaccumulation trends were shown amongst compounds and sediments. Total and organic Hg compounds were accumulated following a non-linear trend, with a sharp increase of tissue concentrations in lugworms exposed to levels of contamination associated to a significant increase in mortality. Interestingly organic Hg compounds accounted for an average of 40% of the total Hg in lugworms exposed to sediments presenting sublethal concentrations while, when exposed to sediments presenting lethal concentrations, organic Hg compounds only accounted for 4% of the total Hg accumulated in lugworms. While lugworms seem to readily accumulate Hg and PCB compounds, with some variability explained by the organic matter content in sediments or other factor for which it accounts for, the results for PAHs suggest a more complex process of bioaccumulation as no relationship was observed between the measured concentrations in sediments and in lugworms, not even after correcting the results for this factor. Besides, the differences in the calculated BSAFs for each compound and for each sediment supported the use of bioassays for evaluating the bioaccumulation potential of sediment-bound contaminants as part of the assessment framework required in pre-dredging investigations, as they still offer unique information about the bioavailability of sediment-bound contaminants.


Asunto(s)
Mercurio/metabolismo , Poliquetos/metabolismo , Bifenilos Policlorados/metabolismo , Hidrocarburos Policíclicos Aromáticos/metabolismo , Contaminantes Químicos del Agua/metabolismo , Animales , Monitoreo del Ambiente/métodos , Sedimentos Geológicos/análisis , Mercurio/análisis , Mercurio/toxicidad , Bifenilos Policlorados/análisis , Bifenilos Policlorados/toxicidad , Hidrocarburos Policíclicos Aromáticos/análisis , Hidrocarburos Policíclicos Aromáticos/toxicidad , España , Contaminantes Químicos del Agua/análisis , Contaminantes Químicos del Agua/toxicidad
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