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1.
Reprod Fertil Dev ; 32(8): 763-773, 2020 May.
Artículo en Inglés | MEDLINE | ID: mdl-32389177

RESUMEN

According to the developmental origins of health and disease (DOHaD) hypothesis, changes in the maternal environment are known to reprogram the metabolic response of offspring. Known for its redox modulation, caloric restriction extends the lifespan of some species, which contributes to diminished cellular damage. Little is known about the effects of gestational caloric restriction, in terms of antioxidant parameters and molecular mechanisms of action, on the reproductive organs of offspring. This study assessed the effects of moderate (20%) caloric restriction on redox status parameters, molecular expression of sirtuin (SIRT) 1 and SIRT3 and histopathological markers in the ovaries and testes of adult rats that were subjected to gestational caloric restriction. Although enzyme activity was increased, ovaries from female pups contained high levels of oxidants, whereas testes from male pups had decreased antioxidant enzyme defences, as evidenced by diminished glyoxalase I activity and reduced glutathione content. Expression of SIRT3, a deacetylase enzyme related to cellular bioenergetics, was increased in both ovaries and testes. Previous studies have suggested that, in ovaries, diminished antioxidant metabolism can lead to premature ovarian failure. Unfortunately, there is little information regarding the redox profile in the testis. This study is the first to assess the redox network in both ovaries and testes, suggesting that, although intrauterine caloric restriction improves molecular mechanisms, it has a negative effect on the antioxidant network and redox status of reproductive organs of young adult rats.


Asunto(s)
Restricción Calórica/efectos adversos , Mitocondrias/metabolismo , Ovario/metabolismo , Efectos Tardíos de la Exposición Prenatal , Sirtuinas/análisis , Testículo/metabolismo , Animales , Antioxidantes/análisis , Antioxidantes/metabolismo , Femenino , Masculino , Ovario/química , Oxidación-Reducción , Embarazo , Ratas , Ratas Wistar , Sirtuina 1/análisis , Sirtuina 3/análisis , Testículo/química
2.
Environ Res ; 159: 164-175, 2017 11.
Artículo en Inglés | MEDLINE | ID: mdl-28802207

RESUMEN

BACKGROUND: Exposure to crystalline silica (SiO2), in the form of quartz, tridymite or cristobalite, can cause respiratory diseases, such as silicosis. However, the observed toxicity and pathogenicity of crystalline silica is highly variable. This has been attributed to a number of inherent and external factors, including the presence of impurities. In cristobalite-rich dusts, substitutions of aluminium (Al) for silicon (Si) in the cristobalite structure, and impurities occluding the silica surface, have been hypothesised to decrease its toxicity. This hypothesis is tested here through the characterisation and in vitro toxicological study of synthesised cristobalite with incremental amounts of Al and sodium (Na) dopants. METHODS: Samples of synthetic cristobalite with incremental amounts of Al and Na impurities, and tridymite, were produced through heating of a silica sol-gel. Samples were characterised for mineralogy, cristobalite purity and abundance, particle size, surface area and surface charge. In vitro assays assessed the ability of the samples to induce cytotoxicity and TNF-α production in J774 macrophages, and haemolysis of red blood cells. RESULTS: Al-only doped or Al+Na co-doped cristobalite contained between 1 and 4 oxide wt% Al and Na within its structure. Co-doped samples also contained Al- and Na-rich phases, such as albite. Doping reduced cytotoxicity to J774 macrophages and haemolytic capacity compared to non-doped samples. Al-only doping was more effective at decreasing cristobalite reactivity than Al+Na co-doping. The reduction in the reactivity of cristobalite is attributed to both structural impurities and a lower abundance of crystalline silica in doped samples. Neither non-doped nor doped crystalline silica induced production of the pro-inflammatory cytokine TNF-α in J774 macrophages. CONCLUSIONS: Impurities can reduce the toxic potential of cristobalite and may help explain the low reactivity of some cristobalite-rich dusts. Whilst further work is required to determine if these effects translate to altered pathogenesis, the results have potential implications for the regulation of crystalline silica exposures.


Asunto(s)
Dióxido de Silicio/inmunología , Dióxido de Silicio/toxicidad , Aluminio/química , Macrófagos/efectos de los fármacos , Macrófagos/inmunología , Dióxido de Silicio/química , Sodio/química , Propiedades de Superficie , Factor de Necrosis Tumoral alfa/inmunología
3.
Clin Exp Immunol ; 177(3): 687-95, 2014 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-24773058

RESUMEN

Hepatitis is a common and potentially fatal manifestation of severe Coxsackievirus infections, particularly in newborn children. Little is known of the immune-mediated mechanisms regulating permissiveness to liver infection. It is well established that type I interferons (IFNs) play an important role in the host innate immune response to Coxsackievirus infections. Recent studies have highlighted a role for another IFN family, the type III IFNs (also called IFN-λ), in anti-viral defence. Whether type III IFNs are produced by hepatocytes during a Coxsackievirus infection remains unknown. Moreover, whether or not type III IFNs protects hepatocytes from a Coxsackievirus infection has not been addressed. In this study, we show that primary human hepatocytes respond to a Coxsackievirus B3 (CVB3) infection by up-regulating the expression of type III IFNs. We also demonstrate that type III IFNs induce an anti-viral state in hepatocytes characterized by the up-regulated expression of IFN-stimulated genes, including IFN-stimulated gene (ISG15), 2'-5'-oligoadenylate synthetase 2 (OAS2), protein kinase regulated by dsRNA (PKR) and myxovirus resistance protein 1 (Mx1). Furthermore, our study reveals that type III IFNs attenuate CVB3 replication both in hepatocyte cell lines and primary human hepatocytes. Our studies suggest that human hepatocytes express type III IFNs in response to a Coxsackievirus infection and highlight a novel role for type III IFNs in regulating hepatocyte permissiveness to this clinically relevant type of virus.


Asunto(s)
Enterovirus/fisiología , Expresión Génica , Hepatocitos/metabolismo , Hepatocitos/virología , Interferón gamma/genética , Adulto , Anciano , Anciano de 80 o más Años , Línea Celular , Infecciones por Coxsackievirus/metabolismo , Enterovirus Humano B/fisiología , Femenino , Hepatocitos/efectos de los fármacos , Hepatocitos/patología , Humanos , Interferón gamma/biosíntesis , Interferón gamma/farmacología , Masculino , Persona de Mediana Edad
4.
Nat Genet ; 29(2): 223-8, 2001 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-11586304

RESUMEN

Linkage disequilibrium (LD) mapping provides a powerful method for fine-structure localization of rare disease genes, but has not yet been widely applied to common disease. We sought to design a systematic approach for LD mapping and apply it to the localization of a gene (IBD5) conferring susceptibility to Crohn disease. The key issues are: (i) to detect a significant LD signal (ii) to rigorously bound the critical region and (iii) to identify the causal genetic variant within this region. We previously mapped the IBD5 locus to a large region spanning 18 cM of chromosome 5q31 (P<10(-4)). Using dense genetic maps of microsatellite markers and single-nucleotide polymorphisms (SNPs) across the entire region, we found strong evidence of LD. We bound the region to a common haplotype spanning 250 kb that shows strong association with the disease (P< 2 x 10(-7)) and contains the cytokine gene cluster. This finding provides overwhelming evidence that a specific common haplotype of the cytokine region in 5q31 confers susceptibility to Crohn disease. However, genetic evidence alone is not sufficient to identify the causal mutation within this region, as strong LD across the region results in multiple SNPs having equivalent genetic evidence-each consistent with the expected properties of the IBD5 locus. These results have important implications for Crohn disease in particular and LD mapping in general.


Asunto(s)
Cromosomas Humanos Par 5 , Enfermedad de Crohn/genética , Citocinas/genética , Predisposición Genética a la Enfermedad , Variación Genética , Familia de Multigenes , Mapeo Cromosómico , Humanos , Desequilibrio de Ligamiento , Polimorfismo de Nucleótido Simple
5.
Nanotoxicology ; 16(4): 484-499, 2022 05.
Artículo en Inglés | MEDLINE | ID: mdl-35913849

RESUMEN

Due to the unique characteristics of nanomaterials (NM) there has been an increase in their use in nanomedicines and innovative medical devices (MD). Although large numbers of NMs have now been developed, comprehensive safety investigations are still lacking. Current gaps in understanding the potential mechanisms of NM-induced toxicity can make it challenging to determine the safety testing necessary to support inclusion of NMs in MD applications. This article provides guidance for implementation of pre-clinical tailored safety assessment strategies with the aim to increase the translation of NMs from bench development to clinical use. Integrated Approaches to Testing and Assessment (IATAs) are a key tool in developing these strategies. IATAs follow an iterative approach to answer a defined question in a specific regulatory context to guide the gathering of relevant information for safety assessment, including existing experimental data, integrated with in silico model predictions where available and appropriate, and/or experimental procedures and protocols for generating new data to fill gaps. This allows NM developers to work toward current guidelines and regulations, while taking NM specific considerations into account. Here, an example IATA for NMs with potential for direct blood contact was developed for the assessment of haemocompatibility. This example IATA brings together the current guidelines for NM safety assessment within a framework that can be used to guide information and data gathering for the safety assessment of intravenously injected NMs. Additionally, the decision framework underpinning this IATA has the potential to be adapted to other testing needs and regulatory contexts.


Asunto(s)
Nanoestructuras , Pruebas de Toxicidad , Simulación por Computador , Nanoestructuras/toxicidad , Medición de Riesgo/métodos , Pruebas de Toxicidad/métodos
6.
Scand J Med Sci Sports ; 21(6): e452-60, 2011 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-22092484

RESUMEN

In this study, the effect of vitamin C and E supplementation on lung injury and performance of runners were analyzed. Using a randomized, double-blinded, crossover design, nine runners participated in two experimental trials: a 2-week Vitamin trial (vitamin C = 500 mg/day + vitamin E = 100 IU/day) and a 2-week Placebo trial. At the end of each supplementation period the runners performed an 8-km time-trial run in a hot (31°C), humid (70% rh), and ozone-polluted (0.10 ppm O(3)) environmental chamber. Nasal lavage and blood samples were collected pre-, post-, and 6-h post-exercise to assess antioxidant status and CC16 as lung injury marker. Higher plasma (pre- and post-exercise) and nasal lavage (post-exercise) antioxidant concentration were found for the Vitamin trial. Nevertheless, this did not result in performance differences (Vitamin trial: 31:05 min; Placebo trial: 31:54 min; P = 0.075) even though significant positive correlations were found between antioxidant concentration and improvement in time to complete the run. CC16 was higher post-exercise in the Placebo trial (P < 0.01) in both plasma and nasal lavage. These findings suggest that antioxidant supplementation might help to decrease the lung injury response of runners when exercising in adverse conditions, but has little effect on performance.


Asunto(s)
Contaminación del Aire/efectos adversos , Ácido Ascórbico/administración & dosificación , Calor/efectos adversos , Humedad/efectos adversos , Lesión Pulmonar/prevención & control , Ozono/efectos adversos , Vitamina E/administración & dosificación , Adulto , Antioxidantes/análisis , Ácido Ascórbico/farmacología , Rendimiento Atlético , Suplementos Dietéticos , Humanos , Lesión Pulmonar/etiología , Masculino , Carrera , Uteroglobina/sangre , Vitamina E/farmacología
7.
Animal ; 15(2): 100032, 2021 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-33573969

RESUMEN

Plant extracts have been recognized as beneficial to human health and have been evaluated as feed additive for domestic and companion animals. This study evaluated oregano and green tea extracts fed to Jersey cows from approximately 21 d before calving to 21 d after calving on milk production, milk composition, and blood metabolites as well as investigated immunological and antioxidant attributes. Twenty-four Jersey cows with 441 ±â€¯27 kg of BW, 3.5 ±â€¯0.3 of body condition score (BCS), and 2.7 ±â€¯1.8 lactations were selected at approximately 28 d before the expected parturition date and were randomly assigned to three treatments with eight cows each: without plant extracts in diet (control - CON), addition of 10 g per day of oregano extract (OR), and addition of 5 g per day of green tea extract (GT). Feed intake, BW, BCS, blood metabolites, hemogram as well as oxidative stress biomarkers were evaluated from approximately 3 weeks prepartum to 3 weeks postpartum (transition period) while milk production and composition were evaluated during the first 3 weeks of lactation. Plant extracts did not change BW, BCS, and DM intake (DMI) throughout the transition period, but OR increased in approximately 20% total digestive nutrients and metabolizable energy intake on days 15 and 16 postpartum compared with CON. In the prepartum, OR increased in 48% platelets count compared to the CON, while GT augmented in 142% eosinophils compared with CON. Oregano extract reduced the levels of reactive species in the erythrocytes in 40% during prepartum and postpartum compared with CON, while GT reduced its levels in 24 and 29% during prepartum and postpartum, respectively, when compared with CON. In the postpartum period, OR increased in 60% the carbonylated protein content compared with CON, while GT reduced in 45% the levels of reactive species in plasma compared with CON. During the postpartum, both extracts increased in 33% the concentration of reduced glutathione when compared with CON. Moreover, GT tended to decrease feed efficiency in 11% when compared with CON; OE reduced milk pH and somatic cell count when compared with CON. In conclusion, OE and GT did not expressively affect immunological attributes in blood but reduce some oxidative stress biomarkers without compromising productive traits of Jersey cows during the transition period.


Asunto(s)
Antioxidantes , Origanum , Animales , Bovinos , Femenino , Dieta/veterinaria , Suplementos Dietéticos , Lactancia , Leche , Periodo Posparto ,
8.
Sci Adv ; 6(19): eaaz2433, 2020 05.
Artículo en Inglés | MEDLINE | ID: mdl-32494709

RESUMEN

Coxsackievirus B (CVB) enteroviruses are common human pathogens known to cause severe diseases including myocarditis, chronic dilated cardiomyopathy, and aseptic meningitis. CVBs are also hypothesized to be a causal factor in type 1 diabetes. Vaccines against CVBs are not currently available, and here we describe the generation and preclinical testing of a novel hexavalent vaccine targeting the six known CVB serotypes. We show that the vaccine has an excellent safety profile in murine models and nonhuman primates and that it induces strong neutralizing antibody responses to the six serotypes in both species without an adjuvant. We also demonstrate that the vaccine provides immunity against acute CVB infections in mice, including CVB infections known to cause virus-induced myocarditis. In addition, it blocks CVB-induced diabetes in a genetically permissive mouse model. Our preclinical proof-of-concept studies demonstrate the successful generation of a promising hexavalent CVB vaccine with high immunogenicity capable of preventing CVB-induced diseases.


Asunto(s)
Infecciones por Coxsackievirus , Miocarditis , Animales , Infecciones por Coxsackievirus/prevención & control , Enterovirus Humano B , Ratones , Primates , Vacunas Combinadas
9.
Inhal Toxicol ; 20(1): 53-62, 2008 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-18236223

RESUMEN

We previously demonstrated the importance of the surface area burden as the key dose metric in the elicitation of inflammation in rat lungs by low-solubility, low-toxicity particles (LSLTP). We have now explored the dosimetry of LSLTP in vitro using epithelial cell interleukin (IL)-8 gene expression as a surrogate for potential of particles to cause inflammation. The proximal alveolar region (PAR) of the lung has been identified as a key site for the retention of respirable particles, as it receives high deposition but has slow clearance compared to the larger airways. For these reasons, a few days after exposure to particles the residual dose is concentrated in the PAR region. Re-expressing our rat lung data as particle surface area burden per unit of PAR surface area we obtained a threshold value for onset of inflammation of 1 cm(2)/cm(2). We carried out dose responses in vitro for onset of IL-8 gene expression with the same particles as we had used in vivo. When we expressed the in vitro dose as surface area dose per unit A549cell culture surface area, we obtained a threshold of 1 cm(2)/cm(2). This concordance between proinflammatory effects in vivo (PMN in BAL) and in vitro (epithelial IL-8 gene expression) confirms and supports the utility of the particle surface area metric and the importance of the PAR. These studies also open the way for future in vitro approaches to studying proinflammatory effects of a range of toxic particles based on sound dosimetry that complements animal use in particle toxicology.


Asunto(s)
Material Particulado/química , Material Particulado/toxicidad , Neumonía/inducido químicamente , Alveolos Pulmonares/efectos de los fármacos , Animales , Línea Celular , Relación Dosis-Respuesta a Droga , Humanos , Imagenología Tridimensional/métodos , Tamaño de la Partícula , Material Particulado/administración & dosificación , Neumonía/fisiopatología , Alveolos Pulmonares/fisiología , Ratas , Ratas Wistar , Solubilidad , Propiedades de Superficie
10.
Toxicol Lett ; 174(1-3): 1-9, 2007 Nov 01.
Artículo en Inglés | MEDLINE | ID: mdl-17888595

RESUMEN

Exposure to nanoparticles may pose a risk to health and this hypothesis is currently being investigated by toxicologists. Although the mechanism of nanoparticle toxicity has been shown to be mediated, in part, by oxidative stress, the precise mechanism and molecules involved are still unknown. In light of this, the evaluation of the oxidative potential of nanoparticles is an important consideration in measuring their toxicity. The aim of this study was to examine the use of a fluorogenic probe, 2',7'-dichlorofluorescin (DCFH), in a cell-free assay system and to assess the relationship between the results obtained with this method and with the reactive species formation observed in cells. In order to obtain a well-dispersed nanoparticle suspension, bovine serum albumin (BSA) and dipalmitoyl phosphatidyl choline (DPPC) addition in suspension medium was investigated. Both 1% BSA and 0.025% DPPC added to the medium significantly improved the stability of the nanoparticle suspension, decreasing the extent of particle agglomeration and settling over time. In a cell-free system, reactive oxygen species (ROS) production by 14nm carbon black particles (CB) suspended in DPPC was higher than that measured with the other suspensions (saline or 1% BSA). A greater ROS production was observed in MonoMac 6 cells (MM6) following treatment with 14nm CB suspended in medium containing BSA and/or DPPC compared to medium alone. In conclusion, 1% BSA and 0.025% DPPC solution was the most efficient for the preparation of a nanoparticle suspension and to measure their oxidative potential.


Asunto(s)
1,2-Dipalmitoilfosfatidilcolina/farmacología , Carbono/toxicidad , Nanopartículas/toxicidad , Especies Reactivas de Oxígeno/metabolismo , Albúmina Sérica Bovina/farmacología , Cloruro de Sodio/farmacología , 1,2-Dipalmitoilfosfatidilcolina/química , Animales , Carbono/química , Bovinos , Línea Celular , Fluoresceínas/química , Fluoresceínas/metabolismo , Peroxidasa de Rábano Silvestre/química , Humanos , Peróxido de Hidrógeno/química , Nanopartículas/química , Oxidantes/química , Oxidación-Reducción , Poliestirenos/química , Especies Reactivas de Oxígeno/química , Albúmina Sérica Bovina/química , Cloruro de Sodio/química
11.
Toxicol Lett ; 168(1): 1-6, 2007 Jan 10.
Artículo en Inglés | MEDLINE | ID: mdl-17129690

RESUMEN

Reactive oxygen species (ROS) have been implicated in various pulmonary diseases by causing direct injury to lung epithelial cells. Signalling activity of cells through transcription factors such as nuclear factor kappa B (NF-kappaB) and AP-1 have been shown to be regulated by ROS, and the release of pro-inflammatory cytokines demonstrated in the study of inflammatory disease. In this study, we examined the effect of the oxidant tert-butylhydroperoxide (tBHP) on mouse J774 macrophages and its ability to cause the release of the pro-inflammatory cytokine tumour necrosis factor alpha (TNF-alpha). The role of calcium as a signalling molecule was studied using various calcium antagonists. The role of the signalling molecule cAMP was also investigated using phosphodiesterase inhibitors PDE1 and PDE4 families. Oxidative stress was investigated in lung epithelial (A549) cells with and without calcium antagonists and PDE inhibitors with regard to their ability to modulate release of the neutrophil chemoattractant interleukin 8 (IL-8). The oxidant tBHP significantly increased the cytosolic calcium concentration in J774 macrophages, which was prevented by the PDE1 inhibitor. The production of TNF-alpha protein by J774 macrophages was mediated by a pathway involving calcium as addition of calcium antagonists inhibited the tBHP stimulated increase in the cytokine. Inhibitors of both PDE1 and PDE4 completely prevented the tBHP stimulated TNF-alpha release suggesting that the cAMP pathway may be important in the oxidant induced signalling pathway leading to gene expression of pro-inflammatory cytokines. In the presence of oxidant alone, A549 epithelial cells released significant amounts of IL-8, which was inhibited by both calcium antagonist treatment and PDE inhibition treatment. These data suggest that ROS-mediated lung inflammation could be mediated at least in part by calcium and elevated PDE activity associated with decreased cAMP in both macrophages and epithelial cells. Inhibition of these pathways may provide a route for treatment of inflammatory lung diseases.


Asunto(s)
Células Epiteliales/efectos de los fármacos , Macrófagos/efectos de los fármacos , Oxidantes/farmacología , Estrés Oxidativo , Inhibidores de Fosfodiesterasa/farmacología , terc-Butilhidroperóxido/farmacología , 3',5'-AMP Cíclico Fosfodiesterasas/antagonistas & inhibidores , 4-(3-Butoxi-4-metoxibencil)-2-imidazolidinona/farmacología , Animales , Calcio/metabolismo , Bloqueadores de los Canales de Calcio/farmacología , Proteínas Quinasas Dependientes de Calcio-Calmodulina/antagonistas & inhibidores , Línea Celular , Quelantes/farmacología , Fosfodiesterasas de Nucleótidos Cíclicos Tipo 1 , Fosfodiesterasas de Nucleótidos Cíclicos Tipo 4 , Ácido Egtácico/análogos & derivados , Ácido Egtácico/farmacología , Células Epiteliales/metabolismo , Interleucina-8/metabolismo , Pulmón/citología , Macrófagos/metabolismo , Ratones , Sulfonamidas/farmacología , Factor de Necrosis Tumoral alfa/metabolismo , Verapamilo/farmacología
12.
Mol Oral Microbiol ; 32(6): 446-454, 2017 12.
Artículo en Inglés | MEDLINE | ID: mdl-28609586

RESUMEN

Even though the oral microbiome is one of the most complex sites on the body it is an excellent model for narrow-spectrum antimicrobial therapy. Current research indicates that disruption of the microbiome leads to a dysbiotic environment allowing for the overgrowth of pathogenic species and the onset of oral diseases. The gram-negative colonizer, Porphyromonas gingivalis has long been considered a key player in the initiation of periodontitis and Streptococcus mutans has been linked to dental caries. With antibiotic research still on the decline, new strategies are greatly needed to combat infectious diseases. By targeting key pathogens, it may be possible to treat oral infections while allowing for the recolonization of the beneficial, healthy flora. In this review, we examine unique strategies to specifically target periodontal pathogens and address what is needed for the success of these approaches in the microbiome era.


Asunto(s)
Antiinfecciosos/uso terapéutico , Disbiosis/tratamiento farmacológico , Disbiosis/microbiología , Microbiota/efectos de los fármacos , Boca/efectos de los fármacos , Boca/microbiología , Antiinfecciosos/farmacología , Biopelículas/efectos de los fármacos , Caries Dental/microbiología , Farmacorresistencia Bacteriana , Homeostasis , Humanos , Enfermedades de la Boca/tratamiento farmacológico , Enfermedades de la Boca/microbiología , Salud Bucal , Periodontitis/tratamiento farmacológico , Periodontitis/microbiología , Porphyromonas gingivalis/efectos de los fármacos , Porphyromonas gingivalis/patogenicidad , Streptococcus mutans/efectos de los fármacos , Streptococcus mutans/patogenicidad
13.
Toxicol Lett ; 155(3): 397-401, 2005 Mar 15.
Artículo en Inglés | MEDLINE | ID: mdl-15649623

RESUMEN

OBJECTIVE: To assess whether fine and ultrafine particles (nanoparticles) have the capacity to activate factors in serum that would induce macrophage migration. This is a model previously reported to investigate complement activation by other respirable particles and fibres. METHOD: Foetal bovine serum was exposed to varying doses of fine and nanoparticle carbon black as well as the oxidant tert-butyl hydroperoxide (tBHP). The subsequent potential of the serum to induce macrophage migration was measured using a macrophage chemotaxis assay. RESULTS: Treatment of serum with 10 mg/ml of nanoparticle carbon black generated substances that induced a 1.8-fold increase in macrophage migration (P<0.001) compared with untreated serum. This effect was partially inhibited by antioxidant intervention. Serum treated with an equivalent mass of fine carbon black did not display any chemotactic potential. tBHP treatment of the serum did not result in the generation of macrophage chemotactic factors. CONCLUSIONS: High doses of nanoparticle carbon black have the capacity to cause chemotactic factor generation in serum, by a mechanism involving ROS generation, although ROS alone, in the form of tBHP are not adequate to generate chemotactic factors in serum.


Asunto(s)
Carbono/farmacología , Activación de Complemento/efectos de los fármacos , Macrófagos/efectos de los fármacos , Animales , Antioxidantes/farmacología , Línea Celular , Movimiento Celular/efectos de los fármacos , Cromanos/farmacología , Macrófagos/inmunología , Ratones , Nanoestructuras , Tamaño de la Partícula , Suero/efectos de los fármacos
14.
J Occup Med Toxicol ; 10: 23, 2015.
Artículo en Inglés | MEDLINE | ID: mdl-26199640

RESUMEN

BACKGROUND: Diatomaceous earth (DE) is mined globally and is potentially of occupational respiratory health concern due to the high crystalline silica content in processed material. DE toxicity, in terms of variability related to global source and processing technique, is poorly understood. This study addresses this variability using physicochemical characterisation and in vitro toxicology assays. METHODS: Nineteen DE samples sourced from around the world, comprising unprocessed, calcined and flux-calcined DE, were analysed for chemical and mineral composition, particle size and morphology, and surface area. The potential toxicity of DE was assessed by its haemolytic capacity, and its ability to induce cytotoxicity or cytokine release by J774 macrophages. RESULTS: The potential toxicity of DE varied with source and processing technique, ranging from non-reactive to as cytotoxic and haemolytic as DQ12. Crystalline silica-rich, flux-calcined samples were all unreactive, regardless of source. The potential toxicity of unprocessed and calcined samples was variable, and did not correlate with crystalline silica content. Calcium-rich phases, iron content, amorphous material, particle size and morphology all appeared to play a role in sample reactivity. An increased surface area was linked to an increased reactivity in vitro for some sample types. CONCLUSIONS: Overall, no single property of DE could be linked to its potential toxicity, but crystalline silica content was not a dominant factor. Occlusion of the potentially toxic crystalline silica surface by an amorphous matrix or other minerals and impurities in the crystal structure are suggested to pacify toxicity in these samples. In vivo verification is required, but these data suggest that crystalline silica content alone is not a sufficient indicator of the potential DE hazard.

15.
J Acquir Immune Defic Syndr (1988) ; 6(7): 831-9, 1993 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-8509983

RESUMEN

At present limited data exist describing the hospital use patterns of intravenous drug users (IVDUs) and women with AIDS. Our objective was to determine if frequency of hospitalization, length of stay (LOS), and cost per hospitalization varied by risk status and gender, controlling for a variety of confounders, including severity of illness as measured by the Turner-Kelly-Ball and Justice AIDS severity of illness systems. We performed a population-based cohort study that compared all women (n = 69) and male IVDUs (n = 74) with AIDS diagnosed in Massachusetts in 1987 with a random sample of all male, nonintravenous drug-using patients diagnosed in that year (n = 148). Frequency of hospitalization, LOS, and cost of hospital care were obtained from hospital billing records for 1987 and 1988. Regression analysis showed 42% longer lengths of stay (p < or = 0.001) and 38% higher cost (p < or = 0.001) per hospitalization for IVDUs with AIDS compared with non-IVDU homosexual AIDS patients. No statistically significant differences by gender were observed. Our results suggest that hospital care for IVDUs is likely to be more expensive. Policymakers should incorporate these data when planning for AIDS care. In addition, instruments to assess severity of illness should incorporate information on intravenous drug use.


Asunto(s)
Síndrome de Inmunodeficiencia Adquirida/economía , Hospitalización/economía , Abuso de Sustancias por Vía Intravenosa/complicaciones , Síndrome de Inmunodeficiencia Adquirida/complicaciones , Adulto , Estudios de Cohortes , Costos y Análisis de Costo , Femenino , Conductas Relacionadas con la Salud , Homosexualidad , Humanos , Tiempo de Internación , Funciones de Verosimilitud , Masculino , Massachusetts , Análisis de Regresión , Estudios Retrospectivos , Factores Sexuales , Conducta Sexual , Abuso de Sustancias por Vía Intravenosa/economía
16.
Neuropsychologia ; 34(1): 23-9, 1996 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-8852690

RESUMEN

Researchers have suggested that the right hemisphere is superior at processing emotional facial expressions because it contains stored perceptual 'templates' of facial expressions. We tested each hemisphere of a split-brain patient on two tasks involving emotional facial expressions. Both hemispheres performed equally well and significantly above chance matching facial expressions with emotion words. The subject's right hemisphere consistently performed well judging whether two facial expressions were the same or different. His left hemisphere performed poorly on this discrimination task at first, but showed a sharp improvement when the instructions were changed slightly, emphasizing verbal labels for the facial expressions. Results suggest that 'facial expression templates' may not be stored only on the right.


Asunto(s)
Emociones/fisiología , Expresión Facial , Lateralidad Funcional/fisiología , Percepción Social , Adulto , Cuerpo Calloso/fisiología , Cuerpo Calloso/cirugía , Discriminación en Psicología/fisiología , Humanos , Masculino , Conducta Verbal , Campos Visuales
17.
Biochem Pharmacol ; 47(4): 625-32, 1994 Feb 11.
Artículo en Inglés | MEDLINE | ID: mdl-8129741

RESUMEN

Isolated rat hepatocyte couplets were used to study the effects of menadione and a rise in the intracellular concentration of calcium on biliary canalicular function. Canalicular function was assessed by counting the percentage of couplets which were able to accumulate the fluorescent cholephile, cholyl lysyl fluorescein (CLF) into the canalicular vacuole between the two cells. Menadione induced a concentration-dependent inhibition of the canalicular vacuole accumulation (CVA) of CLF reaching 7.6 +/- 1.8% of control at 100 microM menadione. This disruption was not prevented by blocking receptor-operated calcium channels with Ni2+ (300 microM). The concentration range of menadione used did not deplete cellular ATP content. In contrast glutathione content was reduced to 52% of its control value by 100 microM menadione. A rise in cytosolic calcium induced by the calcium ionophore, A23187 (up to 30 microM) also disrupted CVA in a concentration-dependent manner. Release of endoplasmic reticulum calcium stores by thapsigargin (50 nM) affected the retention of canalicular contents to a much lesser extent, although it was able to stimulate a reduction in canalicular area to 40% of its original value, assumed to be due to canalicular contraction. Menadione (30 and 100 microM) reduced the fluorescence of phalloidin-FITC-labelled F-actin in both the total and pericanalicular cytoskeleton. Canalicular function was therefore disrupted by non-lethal concentrations of menadione via a mechanism which does not appear to involve ATP depletion or the entry of extracellular calcium, but is associated with a depletion of both cellular glutathione and F-actin. An increase in the concentration of intracellular calcium can stimulate canalicular contraction, and at relatively high concentrations calcium can also disrupt canalicular function.


Asunto(s)
Canalículos Biliares/efectos de los fármacos , Calcio/metabolismo , Vitamina K/farmacología , Actinas/análisis , Adenosina Trifosfato/análisis , Animales , Canalículos Biliares/metabolismo , Citoesqueleto/efectos de los fármacos , Fluorescencia , Glutatión/análisis , Masculino , Ratas , Ratas Wistar , Terpenos/farmacología , Tapsigargina
18.
Environ Health Perspect ; 109 Suppl 4: 523-7, 2001 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-11544157

RESUMEN

Well-documented air pollution episodes throughout recent history have led to deaths among individuals with cardiovascular and respiratory disease. Although the components of air pollution that cause the adverse health effects in these individuals are unknown, a small proportion by mass but a large proportion by number of the ambient air particles are ultrafine, i.e., less than 100 nm in diameter. This ultrafine component of particulate matter with a mass median aerodynamic diameter less than 10 microm (PM(10) may mediate some of the adverse health effects reported in epidemiologic studies and for which there is toxicologic evidence to support this contention. The exact mechanism by which ultrafine particles have adverse effects is unknown, but these particles have recently been shown to enhance calcium influx on contact with macrophages. Oxidative stress is also to be anticipated at the huge particle surface; this can be augmented by oxidants generated by recruited inflammatory leukocytes. Atheromatous plaques form in the coronary arteries and are major causes of morbidity and death associated epidemiologically with particulate air pollution. In populations exposed to air pollution episodes, blood viscosity, fibrinogen, and C-reactive protein (CRP) were higher. More recently, increases in heart rate in response to rising air pollution have been described and are most marked in individuals who have high blood viscosity. In our study of elderly individuals, there were significant rises in CRP, an index of inflammation. In this present review, we consider the likely interactions between the ultrafine particles the acute phase response and cardiovascular disease.


Asunto(s)
Contaminantes Atmosféricos/efectos adversos , Contaminación del Aire/efectos adversos , Enfermedades Cardiovasculares/fisiopatología , Enfermedad Aguda , Enfermedades Cardiovasculares/inducido químicamente , Humanos
19.
Respir Res ; 5: 29, 2004 Dec 21.
Artículo en Inglés | MEDLINE | ID: mdl-15613243

RESUMEN

The effects of PM10, one of the components of particulate air pollution, was investigated using human monocytes and a mouse macrophage cell line (J774). The study aimed to investigate the role of these nanoparticles on the release of the pro-inflammatory cytokine TNF-alpha and IL-1alpha gene expression. We also investigated the role of intracellular calcium signalling events and oxidative stress in control of these cytokines and the effect of the particles on the functioning of the cell cytoskeleton. We showed that there was an increase in intracellular calcium concentration in J774 cells on treatment with PM10 particles which could be significantly reduced with concomitant treatment with the calcium antagonists verapamil, the intracellular calcium chelator BAPTA-AM but not with the antioxidant nacystelyn or the calmodulin inhibitor W-7. In human monocytes, PM10 stimulated an increase in intracellular calcium which was reduced by verapamil, BAPTA-AM and nacystelyn. TNF-alpha release was increased with particle treatment in human monocytes and reduced by only verapamil and BAPTA-AM. IL-1alpha gene expression was increased with particle treatment and reduced by all of the inhibitors. There was increased F-actin staining in J774 cells after treatment with PM10 particles, which was significantly reduced to control levels with all the antagonists tested. The present study has shown that PM10 particles may exert their pro-inflammatory effects by modulating intracellular calcium signalling in macrophages leading to expression of pro-inflammatory cytokines. Impaired motility and phagocytic ability as shown by changes in the F-actin cytoskeleton is likely to play a key role in particle clearance from the lung.


Asunto(s)
Contaminantes Atmosféricos/toxicidad , Señalización del Calcio/inmunología , Interleucina-1/inmunología , Leucocitos Mononucleares/inmunología , Macrófagos/inmunología , Nanoestructuras/toxicidad , Factor de Necrosis Tumoral alfa/inmunología , Contaminantes Atmosféricos/química , Animales , Señalización del Calcio/efectos de los fármacos , Línea Celular , Citocinas/inmunología , Proteínas del Citoesqueleto/inmunología , Citoesqueleto/efectos de los fármacos , Citoesqueleto/inmunología , Regulación de la Expresión Génica/efectos de los fármacos , Regulación de la Expresión Génica/inmunología , Humanos , Leucocitos Mononucleares/efectos de los fármacos , Activación de Macrófagos/efectos de los fármacos , Activación de Macrófagos/inmunología , Macrófagos/efectos de los fármacos , Macrófagos/metabolismo , Ratones , Nanoestructuras/química , Tamaño de la Partícula , Emisiones de Vehículos/toxicidad
20.
Infect Dis Clin North Am ; 14(4): 967-81, 2000 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-11144647

RESUMEN

Primary care of the person with HIV/AIDS is a complex endeavor with many components. The primary care provider's goal is to combine preventive health care interventions that are known to be effective, with ongoing surveillance and treatment of HIV-related and non-HIV-related medical problems, and effective antiretroviral therapy when indicated. The provider needs to have an approach that enhances trust, involves the patient in important health care decisions, and meets the patient's own expectations for health care.


Asunto(s)
Infecciones por VIH , Atención Primaria de Salud/métodos , Infecciones Oportunistas Relacionadas con el SIDA/prevención & control , Fármacos Anti-VIH/uso terapéutico , Quimioterapia Combinada , Femenino , Infecciones por VIH/diagnóstico , Infecciones por VIH/tratamiento farmacológico , Infecciones por VIH/prevención & control , Humanos , Masculino , Inhibidores de la Transcriptasa Inversa/uso terapéutico
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