37 research outputs found
Leaching Properties of Estuarine Harbor Sediment Before and After Electrodialytic Remediation
Electrodialytic remediation (EDR) can be used to extract heavy metals from a variety of different media. In this work, contaminated harbor sediments from two locations in the United States and one in Norway were subjected to EDR, and were compared with batch extractions conducted with the sediment. pH-dependent leaching tests were used to evaluate changes in leaching properties of treated and control sediments. Significant fractions of total concentrations were removed during treatment (35–95% with an average of 75% for all sediments and elements investigated). The release of elements in pH-dependent leaching tests, however, demonstrated equal or greater leaching from treated sediments in the neutral pH range. Dissolved organic carbon appears to be a significant contributor to post-treatment increases in leaching, and dissolution of significant iron and aluminum sorption sites is hypothesized to also play a role. This research highlights the importance of understanding contaminant speciation and availability, as total metals concentrations, in this particular case, do not relate to estimates of the environmental availability of metals (total concentrations were typically two to three orders of magnitude greater than concentrations released during pH-dependent leaching)
A Self-Organized ECM-Mimetic Model Based on an Amphiphilic Multiblock Silk-Elastin-Like co-Recombinamer with a Concomitant Dual Physical Gelation Process
Although significant progress has been made in the area of injectable hydrogels for biomedical applications and model cell niches, further improvements are still needed, especially in terms of mechanical performance, stability, and biomimicry of the native fibrillar architecture found in the extracellular matrix (ECM). This work focuses on the design and production of a silk-elastin-based injectable multiblock corecombinamer that spontaneously forms a stable physical nanofibrillar hydrogel under physiological conditions. That differs from previously reported silk-elastin-like polymers on a major content and predominance of the elastin-like part, as well as a more complex structure and behavior of such a part of the molecule, which is aimed to obtain well-defined hydrogels. Rheological and DSC experiments showed that this system displays a coordinated and concomitant dual gelation mechanism. In a first stage, a rapid, thermally driven gelation of the corecombinamer solution takes place once the system reaches body temperature due to the thermal responsiveness of the elastin-like (EL) parts and the amphiphilic multiblock design of the corecombinamer. A bridged micellar structure is the dominant microscopic feature of this stage, as demonstrated by AFM and TEM. Completion of the initial stage triggers the second, which is comprised of a stabilization, reinforcement, and microstructuring of the gel. FTIR analysis shows that these events involve the formation of β-sheets around the silk motifs. The emergence of such β-sheet structures leads to the spontaneous self-organization of the gel into the final fibrous structure. Despite the absence of biological cues, here we set the basis of the minimal structure that is able to display such a set of physical properties and undergo microscopic transformation from a solution to a fibrous hydrogel. The results point to the potential of this system as a basis for the development of injectable fibrillar biomaterial platforms toward a fully functional, biomimetic, artificial extracellular matrix, and cell niches.Este trabajo forma parte de Proyectos de Investigación financiados por la Comisión Europea a través del Fondo Europeo de Desarrollo Regional (ERDF), por el del MINECO (MAT2013-41723-R, MAT2013- 42473-R, PRI-PIBAR-2011-1403 y MAT2012-38043), la Junta de Castilla y León (VA049A11, VA152A12 y VA155A12) y el Instituto de Salud Carlos III bajo el Centro en Red de Medicina Regenerativa y Terapia Celular de Castilla y León
High-Throughput Profiling of Nanoparticle–Protein Interactions by Fluorescamine Labeling
Leaching Properties of Estuarine Harbor Sediment before and after Electrodialytic Remediation
A mechanistic linkage between oral lichen planus and autoimmune thyroid disease
ObjectiveTo determine the levels of antithyroid antibodies and thyroid hormones in the sera of patients with oral lichen planus (OLP), and to quantify the expression of thyroid proteins in OLP lesions. Subjects and MethodsVenous blood samples were drawn from 110 patients with OLP who had no history of thyroid disease or levothyroxine supplementation (OLP+/LT4-). A random population sample of 657 healthy subjects was used as the control group. Two additional groups were used as comparators. Immunohistochemical and qPCR analyses were performed on tissue specimens collected from the patients with OLP and thyroid disease and healthy subjects. ResultsNo association was found between the presence of antithyroid antibodies and OLP. More patients in the OLP+/LT4- group showed high levels of thyroid-stimulating hormone and low levels of free thyroxine than were seen in the control group. Thyroid-stimulating hormone receptor was more highly expressed in the OLP lesions of patients with thyroid disease than in the healthy oral mucosa. ConclusionsA significant number of patients with OLP who are not previously diagnosed with thyroid disease have thyroid parameters that are compatible with hypothyroidism. The expression of thyroid-stimulating hormone receptor in OLP lesions suggests that mechanisms related to autoimmune thyroid disease are involved in the aetiology of OLP
Models for heritable skin diseases: correlation of morphological and molecular data
International audienceA number of genodermatoses are characterized by distinct morphological markers which have been and are used for classification and diagnosis as well as for identifying causative gene mutations and pathogenetic pathways. Various types of animal models and organotypic cell cultures have been established to provide further insight into disease mechanisms and treatment. Selected examples are: (i) a spontaneous rat model for dominant epidermolysis bullosa revealing similar variability of anchoring fibril expression as in human patients; (ii) PNPLA1 as a new gene involved in autosomal recessive congenital ichthyosis pathology identified from a Golden Retriever breed spontaneously affected by lamellar ichthyosis; (iii) knockout mice for lipoxygenases expressing differential skin barrier defects and compensatory hyperkeratosis; (iv) a long-term skin-humanized mouse model for transglutaminase 1-deficient lamellar ichthyosis, obviously in some respects advantageous to organotypic cell cultures and successfully having been used for enzyme substitution therapy; (v) Persian cat with classical Ehlers-Danlos syndrome. Investigation of such monogenetic disease models can help to understand causal correlations between pathology and clinical manifestations and provide insights towards developing and evaluating novel causal therapies
The association between glyceraldehyde-derived advanced glycation end-products and colorectal cancer risk
Background: A large proportion of colorectal cancers are thought to be associated with unhealthy dietary and lifestyle exposures, particularly energy excess, obesity, hyperinsulinemia, and hyperglycemia. It has been suggested that these processes stimulate the production of toxic reactive carbonyls from sugars such as glyceraldehyde. Glyceraldehyde contributes to the production of a group of compounds known as glyceraldehyde-derived advanced glycation end-products (glycer-AGEs), which may promote colorectal cancer through their proinflammatory and pro-oxidative properties. The objective of this study nested within a prospective cohort was to explore the association of circulating glycer-AGEs with risk of colorectal cancer. Methods: A total of 1,055 colorectal cancer cases (colon n = 659; rectal n = 396) were matchced (1:1) to control subjects. Circulating glycer-AGEs were measured by a competitive ELISA. Multivariable conditional logistic regression models were used to calculate ORs and 95% confidence intervals (95% CI), adjusting for potential confounding factors, including smoking, alcohol, physical activity, body mass index, and diabetes status. Results: Elevated glycer-AGEs levels were not associated with colorectal cancer risk (highest vs. lowest quartile, 1.10; 95% CI, 0.82–1.49). Subgroup analyses showed possible divergence by anatomical subsites (OR for colon cancer, 0.83; 95% CI, 0.57–1.22; OR for rectal cancer, 1.90; 95% CI, 1.14–3.19; Pheterogeneity = 0.14). Conclusions: In this prospective study, circulating glycer-AGEs were not associated with risk of colon cancer, but showed a positive association with the risk of rectal cancer. Impact: Further research is needed to clarify the role of toxic products of carbohydrate metabolism and energy excess in colorectal cancer development