Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Resultados 1 - 20 de 144
Filtrar
1.
Environ Res ; 196: 110337, 2021 05.
Artículo en Inglés | MEDLINE | ID: mdl-33130171

RESUMEN

INTRODUCTION: Exposure to environmental pollutants such as diesel exhaust particles (DEP) increases the risk of asthma and asthma exacerbation. However, the exact mechanisms inducing asthma to low doses of allergens remain poorly understood. The present study aimed to analyse the immunomodulatory effect of the inhalation of DEP in a mouse model exposed to non-asthmagenic doses of soybean hull extract (SHE). MATERIAL AND METHODS: BALB/c ByJ mice were randomly divided into four experimental groups. Two groups received nasal instillations of saline and the other two groups received 3 mg ml-1 SHE during 5 days per week for 3 weeks. One group in each pair also received 150 µg of DEP in the same instillations 3 days per week. SHE-specific IgE levels, oxidative stress, leukocyte pattern and optical projection tomography (OPT) imaging studies were assessed. RESULTS: Inhalation of SHE and/or DEP increased levels of H2O2 in BAL, while coexposure to SHE and DEP increased SHE-specific IgE levels in serum. Inhalation of SHE alone increased eosinophils, B cells, total and resident monocytes and decreased levels of NK cells, while inhalation of DEP increased neutrophils and decreased total monocytes. Regarding dendritic cells (DC), the inhalation of SHE and/or DEP increased the total population, while the inhalation of SHE alone increased Th2-related DCs (CD11b + Ly6C-) and decreased tolerogenic DCs (CD11b-Ly6C-). However, coexposure to SHE and DEP increased oxidative stress-sensitive DCs (CD11b-Ly6C+) and decreased Th1-related DCs (CD11b + Ly6C+). As regards macrophages, inhalation of SHE and DEP decreased total and alveolar populations. DEP deposition in lung tissue did not differ between groups. CONCLUSION: Coexposure to DEP activates the asthmatic response to low doses of soy by triggering the immune response and oxidative stress.


Asunto(s)
Contaminantes Atmosféricos , Asma , Contaminantes Atmosféricos/toxicidad , Alérgenos , Animales , Asma/inducido químicamente , Peróxido de Hidrógeno , Ratones , Ratones Endogámicos BALB C , Glycine max , Emisiones de Vehículos/toxicidad
2.
Environ Res ; 182: 108981, 2020 03.
Artículo en Inglés | MEDLINE | ID: mdl-31830693

RESUMEN

INTRODUCTION: Since the immunopathological mechanisms of bird fancier's lung (BFL) are not well known, we created two models of the disease (acute and chronic BFL) to study and compare the pathways involved in its immunopathogenesis. MATERIALS AND METHODS: C57BL/6 mice were used. Two intraperitoneal injections of 100 µL of commercial pigeon serum (PS) or saline (SAL) were administered with an interval of 48 h in between. Subsequently, intranasal instillations of 40 µL of PS or SAL were performed three days a week, for three weeks in the acute model (AC/PS) and for twelve weeks in the chronic model (CR/PS). Total lung capacity (TLC) was assessed. Pulmonary inflammation was evaluated in bronchoalveolar lavage (BAL), and total serum immunoglobulin (Ig) G was measured in serum samples 24 h, 7 days and 14 days after the last exposure. Histological studies of lungs were assessed. RESULTS: A drop in TLC was observed in treated mice. This decrease was more marked in the CR/PS group (p < 0.001). Neutrophil and lymphocyte counts increased in both AC/PS and CR/PS groups (p < 0.01). The extent of airway inflammation was also examined in the histological analysis of the lungs, which showed predominant perivascular and peribronchiolar inflammation, with centrilobular oedema and subpleural inflammation in the AC/PS group. In the CR/PS group, the changes were greater, with increased levels of IL-5, IL-17F, IL-13 and IL-10 and decreased levels of IL-2. CONCLUSIONS: Bronchial inflammation is present in acute and chronic models of HP following exposure to PS. Our results support the role of neutrophils and IL-17 in the development of the disease and an evolution towards a Th-2 immune response in chronic HP. These models may serve as a tool for future studies of the pathogenesis of HP.


Asunto(s)
Pulmón de Criadores de Aves , Sistema Inmunológico , Pulmón , Animales , Pulmón de Criadores de Aves/inmunología , Líquido del Lavado Bronquioalveolar , Columbidae , Modelos Animales de Enfermedad , Inflamación , Pulmón/patología , Ratones , Ratones Endogámicos C57BL , Modelos Animales
5.
Rev Clin Esp (Barc) ; 2024 Sep 03.
Artículo en Inglés | MEDLINE | ID: mdl-39236980

RESUMEN

Anemia of Inflammation begins with the activation of the immune system and the subsequent release of cytokines that lead to an elevation of hepcidin, responsible for hypoferremia, and a suppression of erythropoiesis due to lack of iron. The anemia is usually mild/moderate, normocytic/normochromic and is the most prevalent, after iron deficiency anemia, and is the most common in patients with chronic diseases, in the elderly and in hospitalized patients. Anemia can influence the patient's quality of life and have a negative impact on survival. Treatment should be aimed at improving the underlying disease and correcting the anemia. Intravenous iron, erythropoietin and prolyl hydroxylase inhibitors are the current basis of treatment, but future therapy is directed against hepcidin, which is ultimately responsible for anemia.

6.
Chemosphere ; 345: 140438, 2023 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-37852379

RESUMEN

Mercury's extreme toxicity and persistence in the environment justifies a thorough evaluation of its dynamics in ecosystems. Aveiro Lagoon (Portugal) was for decades subject to mercury effluent discharges. A Nature-based Solution (NbS) involving Zostera noltei re-colonization is being tested as an active ecosystem restoration measure. To study the effect of Zostera noltei on the sediment contaminant biogeochemistry, seasonal (summer/winter) sediment, interstitial water and labile mercury vertical profiles were made in vegetated (Transplanted and Natural seagrass meadows) and non-vegetated sites (Bare-bottom area). While no significant differences (p > 0.05) were observed in the sedimentary phase, Zostera noltei presence reduced the reactive/labile mercury concentrations in the top sediment layers by up to 40% when compared to non-vegetated sediment, regardless of season. No differences were found between vegetated meadows, highlighting the fast recovery of the contaminant regulation ecosystem function provided by the plants after re-colonization and its potential for the rehabilitation of historically contaminated ecosystems.


Asunto(s)
Mercurio , Zosteraceae , Ecosistema , Mercurio/análisis , Plantas , Portugal , Sedimentos Geológicos
7.
Int J Biol Macromol ; 253(Pt 4): 127070, 2023 Dec 31.
Artículo en Inglés | MEDLINE | ID: mdl-37748588

RESUMEN

Articular cartilage defects comprise a spectrum of diseases associated with degeneration or damage of the connective tissue present in particular joints, presenting progressive osteoarthritis if left untreated. In vitro tissue regeneration is an innovative treatment for articular cartilage injuries that is attracting not only clinical attention, but also great interest in the development of novel biomaterials, since this procedure involves the formation of a neotissue with the help of material support. In this work, functional alginate and waterborne polyurethane (WBPU) scaffolds have been developed for articular cartilage regeneration using 3D bioprinting technology. The particular properties of alginate-WBPU blends, like mechanical strength, elasticity and moistening, mimic the original cartilage tissue characteristics, being ideal for this application. To fabricate the scaffolds, mature chondrocytes were loaded into different alginate-WBPU inks with rheological properties suitable for 3D bioprinting. Bioinks with high alginate content showed better 3D printing performance, as well as structural integrity and cell viability, being most suitable for scaffolds fabrication. After 28 days of in vitro cartilage formation experiments, scaffolds containing 3.2 and 6.4 % alginate resulted in the maintenance of cell number in the range of 104 chondrocytes/scaffold in differentiated phenotypes, capable of synthesizing specialized extracellular matrix (ECM) up to 6 µg of glycosaminoglycans (GAG) and thus, showing a potential application of these scaffolds for in vitro regeneration of articular cartilage tissue.


Asunto(s)
Cartílago Articular , Ingeniería de Tejidos/métodos , Poliuretanos , Andamios del Tejido/química , Alginatos/química , Impresión Tridimensional
8.
Allergol Immunopathol (Madr) ; 40(5): 306-15, 2012.
Artículo en Inglés | MEDLINE | ID: mdl-22264640

RESUMEN

INTRODUCTION: Omalizumab has been demonstrated to be a successful therapy in the management of asthma through reduction of patient's symptoms and use of inhaled corticosteroids. The effect of omalizumab is achieved by immunoglobulin E (IgE) blockage and other secondary mechanisms resulting from this blockage. Because other diseases have an important IgE mediation in their physiopathology, the question arises as to if omalizumab would be useful in the treatment of other IgE-mediated diseases. OBJECTIVE: We present an overview of the experimental studies and clinical reports evaluating the use of omalizumab in diseases different to asthma including atopic dermatitis, urticaria, eosinophilic gastrointestinal disorders, idiopathic anaphylaxis, latex allergy, hymenoptera venom allergy, and other IgE diseases. METHODS: We reviewed the literature using PUBMED, EMBASE, and LILACS for publications which used omalizumab in the treatment of patients with allergic diseases or any other diseases. Complete articles published in English, Spanish or Portuguese were included. CONCLUSION: There is not enough evidence to support the regular use of omalizumab in IgE diseases other than asthma. However, some experimental and clinical investigations indicate that omalizumab could be a therapeutic option in several allergic diseases like atopic dermatitis, urticaria, and eosinophilic gastrointestinal disorders. More control studies are needed in each IgE disease to evaluate the efficacy and safety of omalizumab in IgE mediated diseases.


Asunto(s)
Anticuerpos Antiidiotipos/uso terapéutico , Anticuerpos Monoclonales Humanizados/uso terapéutico , Asma/tratamiento farmacológico , Hipersensibilidad/tratamiento farmacológico , Inmunoglobulina E/inmunología , Animales , Asma/inmunología , Degranulación de la Célula/efectos de los fármacos , Humanos , Hipersensibilidad/inmunología , Terapia de Inmunosupresión/métodos , Activación de Linfocitos/efectos de los fármacos , Omalizumab , Receptores de IgE/inmunología , Estados Unidos , United States Food and Drug Administration
9.
Allergol Immunopathol (Madr) ; 40(1): 3-8, 2012.
Artículo en Inglés | MEDLINE | ID: mdl-21420224

RESUMEN

BACKGROUND: The IL-15/NF-κB axis has an important role in coeliac disease (CD) and may represent a molecular target for immunomodulation. Ascorbate (vitamin C) is known to show inhibitory effects on NF-κB. Therefore, we studied if ascorbate supplementation to gliadin gliadin-stimulated biopsy culture could down-regulate the mucosal immune response to gliadin in CD. METHODS: Duodenal biopsy explants from treated CD patients were gliadin challenged in vitro (100 µg/ml) with and without 20mM ascorbate. An extra tissue explant in basal culture was used as internal control. Secretion levels of nitrites (3h), and IFNγ, TNFα, IFNα, IL-17, IL-13, and IL-6 (24h) were measured on the supernatants. IL-15 was assayed by western-blot on whole protein duodenal explants. RESULTS: The addition of ascorbate to in vitro culture gliadin-challenged biopsies blocked the secretion of nitrites (p=0.013), IFNγ (p=0.0207), TNFα (p=0.0099), IFNα (p=0.0375), and IL-6 (p=0.0036) compared to samples from non-ascorbate supplemented culture. Cytokine secretion was downregulated by ascorbate even to lower values than those observed in basal cultures (IFNγ: p=0.0312; TNFα: p=0.0312; IFNα: p=0.0312; and IL-6: p=0.0078). Gliadin-challenge induced IL-15 production in biopsies from treated CD patients, while the addition of ascorbate to culture medium completely inhibited IL-15 production. Moreover, the inhibition of IL-15 by ascorbate took place even in the only treated CD-patient who had basal IL-15 production. CONCLUSIONS: Ascorbate decreases the mucosal inflammatory response to gluten in an intestinal biopsy culture model, so it might have a role in future supplementary therapy in CD.


Asunto(s)
Ácido Ascórbico/farmacología , Enfermedad Celíaca/tratamiento farmacológico , Gliadina/inmunología , Inflamación/prevención & control , Adulto , Anciano , Biopsia , Enfermedad Celíaca/inmunología , Citocinas/biosíntesis , Femenino , Humanos , Inmunidad Mucosa/efectos de los fármacos , Interleucina-15/antagonistas & inhibidores , Interleucina-15/fisiología , Masculino , Persona de Mediana Edad
10.
J Hazard Mater ; 436: 129044, 2022 08 15.
Artículo en Inglés | MEDLINE | ID: mdl-35525220

RESUMEN

Recent studies have demonstrated the crop uptake of antibiotics (ABs) from soils treated with AB-carrying fertilisers. However, there is a lack of plot-scale studies linking their effects at the agronomic and metabolomic/transcriptomic level to their impact on human health. This paper assesses the plant uptake of 23 ABs following two productive cycles of lettuce and radish cropped with sewage sludge, pig slurry, the organic fraction of municipal solid waste, or chemical fertilisation under plot-scale conditions (32 plots spanning 3-10 m2 each). AB uptake by plants depended on both the vegetable and the AB class and was higher in radish than in lettuce edible parts. Levels ranged from undetectable to up to 76 ng/g (fresh weight). Repetitive organic fertilisation resulted in an increase in the concentration of ABs in lettuce leaves, but not in radish roots. Significant metabolomic and transcriptomic changes were observed following soil fertilisation. Nevertheless, a human health risk assessment indicates that the occurrence of ABs in lettuce or radish edible parts does not pose any risk. To our knowledge, this is the first holistic plot-scale study demonstrating that the use of organic fertilisers containing ABs is safe for crop security and human health.


Asunto(s)
Raphanus , Contaminantes del Suelo , Animales , Antibacterianos/farmacología , Fertilización , Fertilizantes , Humanos , Lactuca , Aguas del Alcantarillado , Suelo , Contaminantes del Suelo/análisis , Porcinos
11.
Prog Urol ; 21(2): 109-13, 2011 Feb.
Artículo en Francés | MEDLINE | ID: mdl-21296277

RESUMEN

OBJECTIVES: We aim to assess the outcome of the flexible ureterorenoscopy (F-URS) with holmium laser in treating horseshoe kidney (HSK) stones. PATIENTS AND METHODS: We reviewed retrospectively the records of 18 patients with HSK stone (18 renal units) who underwent F-URS using holmium laser from December 2004 to October 2009. The mean age was 37.7±6.9 years. The F-URS used after the extracorporeal shock wave lithotripsy (ESWL) failure in eight patients (44.4%) and four patients (22.2%) had PCNL failure. The follow up visit range were between 4 and 6 weeks with plain radiograph (KUB) and renal ultrasound or non contrast computed tomography scan (NCCT). Success rate was defined as stone free or residual fragment less than 3 mm. Use of auxiliary procedures like ESWL were considered as treatment failure. RESULTS: Eighteen patients, three females and 15 males with mean age was 37.7±6.9 years with HSK calculi underwent ureteroscopic management. The presenting symptoms were renal colic, urinary tract infection or hematuria. We found different HSK stone location (11 mixed calyceal, three mixed pelvic and calyceal and four pelvic). The average stone burden was 15.5±7.3 mm and the mean operative time was 112±9.4 minutes. All over procedures were 27, with mean average of 1.5 procedures per patient. The success rate was 89%. CONCLUSION: The F-URS with holmium laser is an efficient minimal invasive procedure in treating HSK stones.


Asunto(s)
Cálculos Renales/cirugía , Riñón/anomalías , Láseres de Estado Sólido/uso terapéutico , Ureteroscopía , Adulto , Terapia Combinada , Femenino , Humanos , Cálculos Renales/complicaciones , Masculino
12.
Rev Esp Enferm Dig ; 102(10): 606-8, 2010 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-21039072

RESUMEN

Pegylated interferon and ribavirin is the treatment of choice in patients with chronic hepatitis C infection. The most common side effects of interferon therapy are flu-like symptoms and psychiatric disorders. Pneumonitis is a less frequent complication associated with non-negligible mortality. We herein report a case of interferon associated pneumonitis in a patient with non-severe clinical symptoms and a normal chest radiography. Physicians should be aware of this entity during the differential diagnosis of respiratory symptoms in patients receiving treatment with interferon due to its high morbimortality and good resolution and outcome after drug withdrawal.


Asunto(s)
Antivirales/efectos adversos , Hepatitis C/complicaciones , Interferón-alfa/efectos adversos , Enfermedades Pulmonares Intersticiales/inducido químicamente , Polietilenglicoles/efectos adversos , Antivirales/uso terapéutico , Hepatitis C/tratamiento farmacológico , Humanos , Interferón alfa-2 , Interferón-alfa/uso terapéutico , Enfermedades Pulmonares Intersticiales/complicaciones , Enfermedades Pulmonares Intersticiales/diagnóstico por imagen , Masculino , Persona de Mediana Edad , Polietilenglicoles/uso terapéutico , Proteínas Recombinantes , Tomografía Computarizada por Rayos X
13.
Rev Clin Esp ; 210(1): 11-6, 2010 Jan.
Artículo en Español | MEDLINE | ID: mdl-20144791

RESUMEN

INTRODUCTION: To describe characteristics of urinary tract infections attended in an Emergency Department. To assess antibiotic prescription and inappropriate treatment implications. METHODS: Adults patients attended in an Emergency Department during 2 months with UTI confirmed with urocultive were included. Appropriate antibiotic treatment was considered if the first antibiotic used was sensitive. We compared patients with appropriate and inappropriate antibiotic treatment. A logistic regression was performed to evaluate variables associated to inappropriate antibiotic treatment. RESULTS: A total of 151 patients were included (61% women, 67.1[22.3] years). Comorbidity was present in 63% of patients. Urinary sepsis was the most frequent diagnosis (32.5%). E coli was isolated in 65.6% of cases, and 10% presented bacteremia. Percentage of inappropriate antibiotic treatment was 20.5. It was associated (uncontrolled analysis) with male gender, elder patients, recent urinary simptoms, urologic manipulation more than 1 month ago, previous antibiotic use (especially ciprofloxacin or amoxicillin-clavulanate) and presentation with urinary sepsis. Logistic regression analysis showed association only with age (HR 0.978 per year, CI95% 0.957-1, p=0.029) and previous antibiotic use (HR 0.298, CI95% 0.098-0.901, p=0.05). Patients with inappropriate antibiotic treatment did not have higher mortality. CONCLUSIONS: Inappropriate antibiotic treatment for UTI in Emergency Department is relatively frequent and it is associated to older age and previous antibiotic use.


Asunto(s)
Antibacterianos/uso terapéutico , Tratamiento de Urgencia , Infecciones Urinarias/tratamiento farmacológico , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Prescripciones de Medicamentos/normas , Servicio de Urgencia en Hospital , Femenino , Humanos , Masculino , Persona de Mediana Edad , Estudios Retrospectivos , Adulto Joven
16.
Semergen ; 46(3): 161-166, 2020 Apr.
Artículo en Español | MEDLINE | ID: mdl-32088158

RESUMEN

INTRODUCTION: To study the quality of spirometry performed in Primary Care in Cantabria (Spain) and the level of compliance with the regulations of this technique of the Spanish Society of Chest Diseases and Thoracic Surgery (SEPAR). MATERIAL AND METHODS: Cross-sectional descriptive study in the Community of Cantabria using an original questionnaire based on the latest SEPAR regulations. The questionnaire was distributed in 2018 by internal mail to the 42 Primary Care Centres of the Cantabrian Health Service, with the coordinators of the PCC and the nurses responsible having been personally contacted by the researchers or by telephone. This is an original survey, based on the regulations of the SEPAR, which evaluates the quality of the material used (model, years of operation, calibration, cleanliness), as well as the training of personnel who perform spirometry. RESULTS: The health personnel responsible for performing spirometry were surveyed in the 42 Primary Care Centres of the Cantabrian Health Service throughout the Cantabrian area. A mean of 564 spirometries are performed per month. A significant number (13%) of spirometers are never calibrated, and only 10.5% of the spirometers are calibrated by the personnel who perform the test in the centre itself. More than half (54, 53.7%) of these professionals have never received specific training to perform spirometry, and only 3.8% of them have experience in performing the test as recommended by SEPAR. As for the cleaning of the devices, 30% of the technicians do not clean the spirometer or the adapter. CONCLUSIONS: 10 years after our initial study lack of training is still being observed in the professionals, and probably translates into invalid spirometry.


Asunto(s)
Atención Primaria de Salud , Estudios Transversales , Humanos , España , Espirometría , Encuestas y Cuestionarios
17.
Environ Pollut ; 263(Pt A): 114600, 2020 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-33618472

RESUMEN

Ammonium persulfate (AP) causes occupational asthma (OA) and diesel exhaust particles (DEP) exacerbate asthma; however, the role of DEP in asthma due to chemical agents has not been assessed to date. Therefore, the present work aims to study the immunomodulatory effects of DEP in a mouse model of chemical asthma. BALB/c ByJ mice were randomly divided into four experimental groups. On days 1 and 8, mice were dermally sensitized with AP or saline. On days 15, 18 and 21, they received intranasal instillations of AP or saline. Two experimental groups received DEP on every of the three challenges. Airway hyperresponsiveness (AHR), lung mechanics, pulmonary inflammation in bronchoalveolar lavage, leukocyte numbers in total lung tissue, oxidative stress and optical projection tomography (OPT) studies were assessed. The AP-sensitized and challenged group showed asthma-like responses, such as airway hyperresponsiveness, increased levels of eosinophils and NKs and lower numbers of monocytes and CD11b-Ly6C- dendritic cells (DCs). Mice exposed to DEP alone showed increased levels of neutrophils and NKs, reduced numbers of monocytes and alveolar macrophages, and increased levels of CD11b + Ly6C- DCs. The AP sensitized and AP + DEP challenged group also showed asthma-like symptoms such as AHR, as well as increased numbers of eosinophils, neutrophils, CD11b + Ly6C- DCs and decreased levels of total and alveolar macrophages and tolerogenic DCs. Particle deposition was visualised using OPT. In the DEP group the particles were distributed relatively evenly, while in the AP + DEP group they were seen mainly in the large conducting airways. The results show that DEP exposure activates the innate immune response and, together with AP, exacerbates asthma immune hallmarks. This mouse model provides the first evidence of the capacity of DEPs to increase CD11b + Ly6C- (Th2-related) DCs. This study also demonstrates, for the first time, a differential deposition pattern of DEP in lungs depending on asthma status.


Asunto(s)
Asma , Hipersensibilidad Respiratoria , Animales , Asma/inducido químicamente , Líquido del Lavado Bronquioalveolar , Pulmón , Ratones , Ratones Endogámicos BALB C , Emisiones de Vehículos/toxicidad
18.
Br J Cancer ; 100(7): 1165-74, 2009 Apr 07.
Artículo en Inglés | MEDLINE | ID: mdl-19277043

RESUMEN

Secreted Frizzled-related protein-1 (sFRP1) associates with Wnt proteins and its loss can lead to activation of Wnt/beta-catenin signalling. It is frequently downregulated in cancer, including prostate cancer, but its function in prostate cancer is unclear because it can increase proliferation of prostate epithelial cells. We investigated the function of sFRP1 in androgen-dependent prostate cancer and found that sFRP1 inhibited androgen receptor (AR) transcriptional activity. In addition, sFRP1 inhibited the proliferation of androgen-dependent LNCaP cells but not of an androgen-independent subline LNCaP-r, suggesting a role in androgen-dependent growth. The inhibition of AR by sFRP1 was unaffected by co-expression of Wnt3a, stabilised beta-catenin or beta-catenin shRNA, suggesting it does not involve Wnt/beta-catenin signalling. Wnt5a also inhibited AR and expression of Wnt5a and sFRP1 together did not further inhibit AR, suggesting that Wnt5a and sFRP1 activate the same signal(s) to inhibit AR. However, sFRP1 inhibition of AR was unaffected by inhibitors of kinases involved in Wnt/Ca(2+) and Wnt/planar cell polarity non-canonical Wnt signalling. Interestingly, the cysteine-rich domain of sFRP1 interacted with Frizzled receptors expressed in prostate cancer cells, suggesting that sFRP1/Frizzled complexes activate a signal that leads to repression of AR. Taken together, these observations highlight the function of beta-catenin-independent Wnt signalling in the control of AR activity and provide one explanation for sFRP1 downregulation in prostate cancer.


Asunto(s)
Glicoproteínas/fisiología , Neoplasias de la Próstata/metabolismo , Receptores Androgénicos/genética , Proteínas Represoras/fisiología , Línea Celular Tumoral , Proliferación Celular , Humanos , Péptidos y Proteínas de Señalización Intracelular , Masculino , Neoplasias de la Próstata/patología , Proteínas Proto-Oncogénicas/fisiología , Transducción de Señal , Proteínas Wnt/fisiología , Proteína Wnt-5a , beta Catenina/fisiología
19.
J Microsc ; 234(1): 38-46, 2009 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-19335455

RESUMEN

Total internal reflection fluorescence microscopy has become a powerful tool to study the dynamics of sub-cellular structures and single molecules near substrate surfaces. However, the penetration depth of the evanescent field, that is, the distance at which the excitation intensity has exponentially decayed to 1/e, is often left undetermined. This presents a limit on the spatial information about the imaged structures. Here, we present a novel method to quantitatively characterize the illumination in total internal reflection fluorescence microscopy using tilted, fluorescently labelled, microtubules. We find that the evanescent field is well described by a single exponential function, with a penetration depth close to theoretically predicted values. The use of in vitro reconstituted microtubules as nanoscale probes results in a minimal perturbation of the evanescent field; excitation light scattering is eliminated and the refractive index of the sample environment is unchanged. The presented method has the potential to provide a generic tool for in situ calibration of the evanescent field.


Asunto(s)
Microscopía Fluorescente/métodos , Microscopía Fluorescente/normas , Microtúbulos , Animales , Química Encefálica , Calibración , Porcinos , Tubulina (Proteína)/aislamiento & purificación
20.
J Hazard Mater ; 154(1-3): 175-83, 2008 Jun 15.
Artículo en Inglés | MEDLINE | ID: mdl-18006153

RESUMEN

The synthesis of geopolymer matrixes from coal (co-)combustion fly ashes as the sole source of silica and alumina has been studied in order to assess both their capacity to immobilise the potentially toxic elements contained in these coal (co-)combustion by-products and their suitability to be used as cement replacements. The geopolymerisation process has been performed using (5, 8 and 12 M) NaOH solutions as activation media and different curing time (6-48 h) and temperature (40-80 degrees C) conditions. Synthesised geopolymers have been characterised with regard to their leaching behaviour, following the DIN 38414-S4 [DIN 38414-S4, Determination of leachability by water (S4), group S: sludge and sediments. German standard methods for the examination of water, waste water and sludge. Institut für Normung, Berlin, 1984] and NEN 7375 [NEN 7375, Leaching characteristics of moulded or monolithic building and waste materials. Determination of leaching of inorganic components with the diffusion test. Netherlands Normalisation Institute, Delft, 2004] procedures, and to their structural stability by means of compressive strength measurements. In addition, geopolymer mineralogy, morphology and structure have been studied by X-ray diffraction (XRD), scanning electron microscopy (SEM) and Fourier transform infrared spectroscopy (FTIR), respectively. It was found that synthesised geopolymer matrixes were only effective in the chemical immobilisation of a number of elements of environmental concern contained in fly ashes, reducing (especially for Ba), or maintaining their leachable contents after the geopolymerisation process, but not for those elements present as oxyanions. Physical entrapment does not seem either to contribute in an important way, in general, to the immobilisation of oxyanions. The structural stability of synthesised geopolymers was mainly dependent on the glass content of fly ashes, attaining at the optimal activation conditions (12 M NaOH, 48 h, 80 degrees C) compressive strength values about 60 MPa when the fly ash glass content was higher than 90%.


Asunto(s)
Carbono , Carbón Mineral , Materiales de Construcción , Residuos Industriales , Material Particulado , Administración de Residuos/métodos , Ceniza del Carbón , Fuerza Compresiva , Microscopía Electrónica de Rastreo , Polímeros/química , Centrales Eléctricas , Hidróxido de Sodio/química , Espectroscopía Infrarroja por Transformada de Fourier , Difracción de Rayos X
SELECCIÓN DE REFERENCIAS
Detalles de la búsqueda