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1.
J Endocrinol Invest ; 47(2): 455-468, 2024 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-37480475

RESUMEN

PURPOSE: Nearly, 40% of the causes of male infertility remain idiopathic. The only suggested treatment in idiopathic oligo- and/or asthenozoospermia in normogonadotropic patients is the FSH. In the current clinical practice, efficacy is exclusively assessable through semen analysis after 3 months of treatment. No molecular markers of treatment efficacy are appliable in clinical practice. The aim of the present work is to evaluate the combination of extracellular signal regulated kinase (ERK) 1 and 2 and prolactin inducible peptide (PIP) as potential markers of idiopathic infertility and FSH treatment efficacy. METHODS: Western blot and confocal microscopy were performed to analyze the modulation of PIP and ERK1/2 in idiopathic infertile patients (IIP) sperm cells. Taking advantage of mass spectrometry analysis, we identified these proteins unequivocally in sperm cells. RESULTS:  We demonstrated a significant decrease of both PIP protein and of ERK1/2 levels in spermatozoa obtained from IIP in comparison to healthy fertile patients (HFP). Conversely, we reported a significant increase of these markers comparing infertile patients before and after 3 months of FSH treatment. Importantly, this correlated with an increase in total number of sperm and sperm motility after FSH treatment. Finally, we identified of PIP and ERK2 proteins in sperm samples by proteomic analysis. CONCLUSIONS: The combined evaluation of ERK1/2 and PIP proteins might represent a useful molecular marker to tailor FSH treatment in the management of male normogonadotropic idiopathic infertility.


Asunto(s)
Infertilidad Masculina , Prolactina , Masculino , Humanos , Quinasas MAP Reguladas por Señal Extracelular , Proteómica , Semen , Motilidad Espermática , Espermatozoides , Infertilidad Masculina/tratamiento farmacológico , Resultado del Tratamiento , Hormona Folículo Estimulante/uso terapéutico
2.
Clin Exp Immunol ; 199(2): 163-171, 2020 02.
Artículo en Inglés | MEDLINE | ID: mdl-31618438

RESUMEN

Several reports have highlighted the abnormal increments of serum immunoglobulin free light chains (FLCs) in the course of systemic autoimmune rheumatic diseases (SARD), but a comparative analysis among different conditions is still lacking. A strong association between elevated FLC and hepatitis C virus (HCV)-related mixed cryoglobulinaemia (HCVMC) has been well established. Here, we aimed to analyse serum FLC levels in patients with four different SARD in comparison with HCVMC. Using a turbidimetric assay, free κ and λ chains were quantified in sera from 198 SARD patients (37 rheumatoid arthritis, RA; 47 systemic lupus erythematosus, SLE; 52 anti-phospholipid syndrome, APS; 62 primary Sjogren's syndrome, pSS), 62 HCVMC and 50 healthy blood donors (HD). All patient groups showed increased κ levels when compared to HD: 33·5 ± 2·6 mg/l in HCVMC, 26·7 ± 2·3 mg/l in RA, 29·7 ± 1·9 mg/l in SLE, 23·8 ± 1·1 mg/l in APS, 24·2 ± 1·1 mg/l in pSS; 10·1 ± 0·6 mg/l in HD. Free λ levels displayed a significant increase only for HCVMC (20·4 ± 1·4 mg/l) and SLE (18·4 ± 1·0 mg/l) compared to HD (13·6 ± 0·9 mg/l). The increase of κ compared to λ takes into account a κ /λ ratio of 1·6 for all groups. Our results substantially analyse and strengthen the association between FLC and SARD focusing the questions regarding their role in the pathogenesis and diagnosis of human diseases. Unfortunately, the biochemical differences distinguishing normal from pathological FLC have not been identified. Production of different isotypes is probably connected to still-unknown pathways.


Asunto(s)
Enfermedades Autoinmunes/sangre , Crioglobulinemia/sangre , Hepacivirus , Hepatitis C/sangre , Cadenas kappa de Inmunoglobulina/sangre , Cadenas lambda de Inmunoglobulina/sangre , Enfermedades Reumáticas/sangre , Anciano , Enfermedades Autoinmunes/inmunología , Crioglobulinemia/inmunología , Femenino , Hepatitis C/inmunología , Hepatitis C/patología , Humanos , Cadenas kappa de Inmunoglobulina/inmunología , Cadenas lambda de Inmunoglobulina/inmunología , Masculino , Persona de Mediana Edad , Enfermedades Reumáticas/inmunología
3.
J Microsc ; 280(3): 287-296, 2020 12.
Artículo en Inglés | MEDLINE | ID: mdl-32885445

RESUMEN

In physiological conditions, red blood cells (RBCs) are capable of dramatic deformations when passing through the microvasculature. This extreme deformability is closely related to the RBC biconcave shape, to the fluidic nature of the haemoglobin and the cell membrane structure, primarily consisting of a phospholipid bilayer with an underlying two-dimensional spectrin network. In many pathological and inflammatory conditions, the shape and the extreme deformability of erythrocytes appear to be significantly altered. These findings have stimulated intense research towards the search and validation of novel erythrocyte-based mechanical biomarkers, useful for disease diagnosis and therapy monitoring. In this study, we investigated with Atomic Force Microscopy (AFM) the mechanical properties of erythrocytes obtained from a 68 years old cirrhotic man diagnosed with spur cell anaemia and cold agglutinated disease, before and after liver transplantation. Mechanical changes are compared with ultrastructural alterations as studied by scanning electron microscopy and discussed according to confocal fluorescence microscopy results, showing possible alterations induced by the cirrhotic environment at the level of the RBCs cytoskeletal organisation and lipidic composition. Taken together, the results here presented show that liver transplantation not only contributes to restoring the proper RBC morphology, but it also induces recovery of the physiological viscous behaviour of cells, further stressing the relevance of viscous and dissipative forces in determining the RBC biomechanical response.


Asunto(s)
Membrana Celular/fisiología , Elasticidad/fisiología , Eritrocitos/fisiología , Eritrocitos/ultraestructura , Trasplante de Hígado/métodos , Anciano , Anemia/patología , Membrana Celular/ultraestructura , Humanos , Cirrosis Hepática/patología , Cirrosis Hepática/cirugía , Masculino , Microscopía de Fuerza Atómica/métodos , Microscopía Electrónica de Rastreo
4.
Chaos ; 30(3): 033135, 2020 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-32237785

RESUMEN

The present paper concerns a new description of changing in metabolism during incremental exercises test that permit an individually tailored program of exercises for obese subjects. We analyzed heart rate variability from RR interval time series (tachogram) with an alternative approach, the recurrence quantification analysis, that allows a description of a time series in terms of its dynamic structure and is able to identify the phase transitions. A transition in cardiac signal dynamics was detected and it perfectly reflects the aerobic threshold, as identified by gas exchange during an incremental exercise test, revealing the coupling from the respiratory system toward the heart. Moreover, our analysis shows that, in the recurrence plot of RR interval, it is possible to identify a specific pattern that allows to identify phase transitions between different dynamic regimes. The perfect match of the occurrence of the phase transitions with changes observed in the VO2 consumption, the gold standard approach to estimate thresholds, strongly supports the possibility of using our analysis of RR interval to detect metabolic threshold. In conclusion, we propose a novel nonlinear data analysis method that allows for an easy and personalized detection of thresholds both from professional and even from low-cost wearable devices, without the need of expensive gas analyzers.


Asunto(s)
Prueba de Esfuerzo , Frecuencia Cardíaca , Obesidad , Consumo de Oxígeno , Adulto , Femenino , Humanos , Masculino , Persona de Mediana Edad , Obesidad/sangre , Obesidad/fisiopatología
5.
J Intern Med ; 283(3): 303-313, 2018 03.
Artículo en Inglés | MEDLINE | ID: mdl-29205566

RESUMEN

BACKGROUND: Mycobacterium tuberculosis (MTB), the aetiological agent of tuberculosis (TB), is capable of interfering with the phagosome maturation pathway, by inhibiting phagosome-lysosome fusion and the autophagic process to ensure survival and replication in macrophages. Thus, it has been proposed that the modulation of autophagy may represent a therapeutic approach to reduce MTB viability by enhancing its clearance. OBJECTIVE: The aim of this study was to investigate whether transglutaminase type 2 (TG2) is involved in the pathogenesis of MTB. RESULTS: We have shown that either genetic or pharmacological inhibition of TG2 leads to a marked reduction in MTB replicative capacity. Infection of TG2 knockout mice demonstrated that TG2 is required for MTB intracellular survival in macrophages and host tissues. The same inhibitory effect can be reproduced in vitro using Z-DON, a specific inhibitor of the transamidating activity of TG2. Massive cell death observed in macrophages that properly express TG2 is hampered by the absence of the enzyme and can be largely reduced by the treatment of wild-type macrophages with the TG2 inhibitor. Our data suggest that reduced MTB replication in cells lacking TG2 is due to the impairment of LC3/autophagy homeostasis. Finally, we have shown that treatment of MTB-infected murine and human primary macrophages with cystamine, a TG2 inhibitor already tested in clinical studies, causes a reduction in intracellular colony-forming units in human macrophages similar to that achieved by the anti-TB drug capreomycin. CONCLUSION: These results suggest that inhibition of TG2 activity is a potential novel approach for the treatment of TB.


Asunto(s)
Proteínas de Unión al GTP/metabolismo , Mycobacterium tuberculosis/patogenicidad , Transglutaminasas/metabolismo , Tuberculosis/metabolismo , Animales , Autofagia , Western Blotting , Células Cultivadas , Modelos Animales de Enfermedad , Macrófagos/metabolismo , Macrófagos/ultraestructura , Masculino , Ratones , Ratones Endogámicos C57BL , Microscopía Confocal , Microscopía Electrónica de Transmisión , Proteína Glutamina Gamma Glutamiltransferasa 2 , Tuberculosis/microbiología , Tuberculosis/patología
6.
Biochim Biophys Acta Mol Basis Dis ; 1863(9): 2182-2191, 2017 09.
Artículo en Inglés | MEDLINE | ID: mdl-28572004

RESUMEN

Dystroglycan (DG) serves as an adhesion complex linking the actin cytoskeleton to the extracellular matrix. DG is encoded by a single gene as a precursor, which is constitutively cleaved to form the α- and ß-DG subunits. α-DG is a peripheral protein characterized by an extensive glycosylation that is essential to bind laminin and other extracellular matrix proteins, while ß-DG binds the cytoskeleton proteins. The functional properties of DG depend on the correct glycosylation of α-DG and on the cross-talk between the two subunits. A reduction of α-DG glycosylation has been observed in muscular dystrophy and cancer while the inhibition of the interaction between α- and ß-DG is associated to aberrant post-translational processing of the complex. Here we used confocal microscopy based techniques to get insights into the influence of α-DG glycosylation on the functional properties of the ß-DG, and its effects on cell migration. We used epithelial cells transfected with wild-type and with a mutated DG harboring the mutation T190M that has been recently associated to dystroglycanopathy. We found that α-DG hypoglycosylation, together with an increased protein instability, reduces the membrane dynamics of the ß-subunit and its clustering within the actin-rich domains, influencing cell migration and spontaneous cell movement. These results contribute to give novel insights into the involvement of aberrant glycosylation of DG in the developing of muscular dystrophy and tumor metastasis.


Asunto(s)
Movimiento Celular , Distroglicanos/metabolismo , Seudópodos/metabolismo , Animales , Línea Celular , Distroglicanos/genética , Glicosilación , Ratones , Microscopía Confocal , Estabilidad Proteica , Seudópodos/genética
7.
Br J Cancer ; 112(10): 1675-86, 2015 May 12.
Artículo en Inglés | MEDLINE | ID: mdl-25880005

RESUMEN

BACKGROUND: Despite the recognised contribution of the stroma to breast cancer development and progression, the effective targeting of the tumor microenvironment remains a challenge to be addressed. We previously reported that normal fibroblasts (NFs) and, notably, breast cancer-associated fibroblasts (CAFs) induced epithelial-to-mesenchymal transition and increases in cell membrane fluidity and migration in well- (MCF-7) and poorly-differentiated (MDA-MB-231) breast cancer cells. This study was designed to better define the role played, especially by CAFs, in promoting breast tumor cell migration. METHODS: Fibroblast/breast cancer cell co-cultures were set up to investigate the influence of NFs and CAFs on gene and protein expression of Stearoyl-CoA desaturase 1 (SCD1), the main enzyme regulating membrane fluidity, as well as on the protein level and activity of its transcription factor, the sterol regulatory element-binding protein 1 (SREBP1), in MCF-7 and MDA-MB-231 cells. To assess the role of SREBP1 in the regulation of SCD1 expression, the desaturase levels were also determined in tumor cells treated with an SREBP1 inhibitor. Migration was evaluated by wound-healing assay in SCD1-inhibited (by small-interfering RNA (siRNA) or pharmacologically) cancer cells and the effect of CAF-conditioned medium was also assessed. To define the role of stroma-derived signals in cancer cell migration speed, cell-tracking analysis was performed in the presence of neutralising antibodies to hepatocyte growth factor, transforming growth factor-ß or basic fibroblast growth factor. RESULTS: A two to three fold increase in SCD1 mRNA and protein expression has been induced, particularly by CAFs, in the two cancer cell lines that appear to be dependent on SREBP1 activity in MCF-7 but not in MDA-MB-231 cells. Both siRNA-mediated and pharmacological inhibition of SCD1 impaired tumor cells migration, also when promoted by CAF-released soluble factors. Fibroblast-triggered increase in cancer cell migration speed was markedly reduced or abolished by neutralising the above growth factors. CONCLUSION: These results provide further insights in understanding the role of CAFs in promoting tumor cell migration, which may help to design new stroma-based therapeutic strategies.


Asunto(s)
Neoplasias de la Mama/enzimología , Neoplasias de la Mama/patología , Movimiento Celular/genética , Fibroblastos/patología , Comunicación Paracrina/genética , Estearoil-CoA Desaturasa/genética , Neoplasias de la Mama/genética , Diferenciación Celular/genética , Línea Celular Tumoral , Membrana Celular/genética , Técnicas de Cocultivo/métodos , Transición Epitelial-Mesenquimal/genética , Femenino , Factores de Crecimiento de Fibroblastos/genética , Factor de Crecimiento de Hepatocito/genética , Humanos , Células MCF-7 , ARN Mensajero/genética , ARN Interferente Pequeño/genética , Factor de Crecimiento Transformador beta/genética
8.
Soft Matter ; 11(28): 5719-26, 2015 Jul 28.
Artículo en Inglés | MEDLINE | ID: mdl-26083581

RESUMEN

SW480 and SW620 colon carcinoma cell lines derive from primary tumour and lymph-node metastasis of the same patient, respectively. For this reason, these cells represent an ideal system to analyse phenotypic variations associated with the metastatic process. In this study we analysed SW480 and SW620 cytoskeleton remodelling by measuring the cells' mechanics and morphological properties using different microscopic techniques. We observed that different specialized functions of cells, i.e. the capacity to metastasize of elongated cells inside the primary tumour and the ability to intravasate and resist shear forces of the stream of cells derived from lymph node metastasis, are reflected in their mechanical properties. We demonstrated that, together with stiffness and adhesion between the AFM tip and the cell surface, cell shape, actin organization and surface roughness are strictly related and are finely modulated by colorectal cancer cells to better accomplish their specific tasks in cancer growth and invasion.


Asunto(s)
Neoplasias Colorrectales/ultraestructura , Citoesqueleto/ultraestructura , Ganglios Linfáticos/ultraestructura , Invasividad Neoplásica/ultraestructura , Línea Celular Tumoral , Forma de la Célula , Neoplasias Colorrectales/química , Neoplasias Colorrectales/patología , Citoesqueleto/química , Humanos , Ganglios Linfáticos/química , Metástasis Linfática/patología , Metástasis Linfática/ultraestructura , Fenómenos Mecánicos , Microscopía de Fuerza Atómica , Invasividad Neoplásica/patología , Propiedades de Superficie
9.
APL Bioeng ; 8(1): 016115, 2024 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-38435469

RESUMEN

The pressing need for multifunctional materials in medical settings encompasses a wide array of scenarios, necessitating specific tissue functionalities. A critical challenge is the occurrence of biofouling, particularly by contamination in surgical environments, a common cause of scaffolds impairment. Beyond the imperative to avoid infections, it is also essential to integrate scaffolds with living cells to allow for tissue regeneration, mediated by cell attachment. Here, we focus on the development of a versatile material for medical applications, driven by the diverse time-definite events after scaffold implantation. We investigate the potential of incorporating graphene oxide (GO) into polycaprolactone (PCL) and create a composite for 3D printing a scaffold with time-controlled antibacterial and anti-adhesive growth properties. Indeed, the as-produced PCL-GO scaffold displays a local hydrophobic effect, which is translated into a limitation of biological entities-attachment, including a diminished adhesion of bacteriophages and a reduction of E. coli and S. aureus adhesion of ∼81% and ∼69%, respectively. Moreover, the ability to 3D print PCL-GO scaffolds with different heights enables control over cell distribution and attachment, a feature that can be also exploited for cellular confinement, i.e., for microfluidics or wound healing applications. With time, the surface wettability increases, and the scaffold can be populated by cells. Finally, the presence of GO allows for the use of infrared light for the sterilization of scaffolds and the disruption of any bacteria cell that might adhere to the more hydrophilic surface. Overall, our results showcase the potential of PCL-GO as a versatile material for medical applications.

10.
Nanotechnology ; 24(49): 495302, 2013 Dec 13.
Artículo en Inglés | MEDLINE | ID: mdl-24231603

RESUMEN

In this paper we present a simple and robust method to realize highly ordered arrays of stretched and suspended DNA molecules over the millimeter length scale. To this end we used an ad hoc designed superhydrophobic surface made of high aspect-ratio silicon pillars, where we deposited a droplet containing genomic DNA. A precise positioning of DNA strands was achieved by shaping the silicon pillars so that sharpened features resembling tips were included. Such features allowed us to accurately control the droplet de-wetting dynamics, pinning DNA strands in a well-defined position above pillars. The proposed technique has the potential to positively impact on the development of novel DNA chips for genetic analysis.


Asunto(s)
ADN/análisis , Nanoestructuras/química , Análisis de Secuencia por Matrices de Oligonucleótidos/instrumentación , Propiedades de Superficie , Sangre/metabolismo , Diseño de Equipo , Humanos , Interacciones Hidrofóbicas e Hidrofílicas , Ensayo de Materiales , Nanotecnología , Humectabilidad
11.
Microsc Microanal ; 18(5): 1088-94, 2012 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-23026204

RESUMEN

Aspergillus fumigatus has become a leading cause of fungal morbidity and mortality, especially in immunocompromised patients. This fungus is able to grow as a multicellular community and produce a hydrophobic extracellular matrix (ECM), mainly composed of galactomannan and α-1,3 glucans, to protect itself from host defenses and antimicrobial drugs. This matrix envelops the fungus hyphae, binding them into a contiguous sheath on the colony surface, forming a biofilm and increasing the fungal resistance to adverse environmental factors. Adherence to host cells and resistance to physical removal play a key role in fungal colonization and invasion of the host and in a wide range of infections. Here we show that, by using atomic force spectroscopy, it is possible to exploit the peculiar hydrophobicity of the biofilm components (i.e., cell walls, ECM) to detect the biofilm spread, its growth, and lysis on rough surfaces. By means of this approach, we demonstrate that alginate lyase, an enzyme known to reduce negatively charged alginate levels in microbial biofilms, reduces the biofilm adhesion forces suggesting a loss of ECM from the biofilm, which could be used to enhance pharmacological treatments.


Asunto(s)
Aspergillus fumigatus/enzimología , Aspergillus fumigatus/crecimiento & desarrollo , Biopelículas , Proteínas Fúngicas/química , Polisacárido Liasas/química , Aspergillus fumigatus/química , Aspergillus fumigatus/citología , Biopelículas/crecimiento & desarrollo , Proteínas Fúngicas/metabolismo , Interacciones Hidrofóbicas e Hidrofílicas , Microscopía de Fuerza Atómica , Polisacárido Liasas/metabolismo
12.
Comput Biol Med ; 145: 105423, 2022 06.
Artículo en Inglés | MEDLINE | ID: mdl-35367782

RESUMEN

2-deoxy-2-fluorine-(18F)fluoro-d-glucose Positron Emission Tomography/Computed Tomography (18F-FDG-PET/CT) is widely used in oncology mainly for diagnosis and staging of various cancer types, including lung cancer, which is the most common cancer worldwide. Since histopathologic subtypes of lung cancer show different degree of 18F-FDG uptake, to date there are some diagnostic limits and uncertainties, hindering an 18F-FDG-PET-driven classification of histologic subtypes of lung cancers. On the other hand, since activated macrophages, neutrophils, fibroblasts and granulation tissues also show an increased 18F-FDG activity, infectious and/or inflammatory processes and post-surgical and post-radiation changes may cause false-positive results, especially for lymph-nodes assessment. Here we propose a model-free, machine-learning based algorithm for the automated classification of adenocarcinoma, the most common type of lung cancer, and other types of tumors. Input for the algorithm are dynamic acquisitions of PET data (dPET), providing for a spatially and temporally resolved characterization of the uptake kinetic. The algorithm consists in a trained Random Forest classifier which, relying contextually on several spatial and temporal features of 18F-FDG uptake, generates as an outcome probability maps allowing to distinguish adenocarcinoma from other lung histotype and to identify metastatic lymph-nodes, ultimately increasing the specificity of the technique. Its performance, evaluated on a dPET dataset of 19 patients affected by primary lung cancer, provides a probability 0.943 ± 0.090 for the detection of adenocarcinoma. The use of this algorithm will guarantee an automatic and more accurate localization and discrimination of tumors, also providing a powerful tool for detecting at which extent tumor has spread beyond a primary tumor into lymphatic system.


Asunto(s)
Adenocarcinoma , Neoplasias Pulmonares , Fluorodesoxiglucosa F18 , Humanos , Neoplasias Pulmonares/diagnóstico por imagen , Neoplasias Pulmonares/patología , Ganglios Linfáticos/patología , Metástasis Linfática/patología , Aprendizaje Automático , Tomografía Computarizada por Tomografía de Emisión de Positrones/métodos , Tomografía de Emisión de Positrones/métodos , Radiofármacos
13.
Biophys J ; 99(6): 1791-800, 2010 Sep 22.
Artículo en Inglés | MEDLINE | ID: mdl-20858423

RESUMEN

Peptide-induced vesicle leakage is a common experimental test for the membrane-perturbing activity of antimicrobial peptides. The leakage kinetics is usually very slow, requiring minutes to hours for complete release of vesicle contents, and exhibits a biphasic behavior. We report here that, in the case of the peptaibol trichogin GA IV, all processes involved in peptide-membrane interaction, such as peptide-membrane association, peptide aggregation, and peptide translocation, take place on a timescale much shorter than the leakage kinetics. On the basis of these findings, we propose a stochastic model in which the leakage kinetics is determined by the discrete nature of a vesicle suspension: peptides are continuously exchanging among vesicles, producing significant fluctuations over time in the number of peptide molecules bound to each vesicle, and in the formation of pores. According to this model, the fast initial leakage is caused by vesicles that contain at least one pore after the peptides are randomly distributed among the liposomes, whereas the slower release is associated with the time needed to occasionally reach in an intact vesicle the critical number of bound peptides necessary for pore formation. Fluctuations due to peptide exchange among vesicles therefore represent the rate-limiting step of such a slow mechanism.


Asunto(s)
Péptidos Catiónicos Antimicrobianos/farmacología , Membrana Celular/efectos de los fármacos , Membrana Celular/metabolismo , Liposomas Unilamelares/metabolismo , Secuencia de Aminoácidos , Péptidos Catiónicos Antimicrobianos/química , Péptidos Catiónicos Antimicrobianos/metabolismo , Cinética , Modelos Biológicos , Transporte de Proteínas , Procesos Estocásticos , Termodinámica
14.
Eur Biophys J ; 39(6): 1001-6, 2010 May.
Artículo en Inglés | MEDLINE | ID: mdl-19517104

RESUMEN

Ischemic heart disease is the leading cause of serious morbidity and mortality in Western society. One of the therapeutic approaches is based on the use of thrombolitic drugs that promote clot lysis. Even if the mechanisms leading to clot lysis are not completely understood, it is widely accepted that they depend on the complex biochemical reactions that occur among fibrin fibers and fibrinolitic agents, and by their ready diffusion into the fibers. Here we investigate the effects of specific anions on the architecture of protofibrils within fibrin fibers in fibrin gels prepared in a para-physiological solution. The results obtained through small-angle X-ray scattering (SAXS) demonstrate that the characteristic axial and longitudinal repeat distances among protofibrils are strongly affected by the action of Cl(-) and F(-) anions.


Asunto(s)
Cloruros/química , Fibrina/química , Fluoruros/química , Geles/química , Rayos X , Aniones/química , Fibrinolíticos/metabolismo , Conformación Proteica , Dispersión de Radiación , Dispersión del Ángulo Pequeño , Difracción de Rayos X/métodos
15.
Eur Biophys J ; 39(6): 993-9, 2010 May.
Artículo en Inglés | MEDLINE | ID: mdl-19495741

RESUMEN

Neuronal redox phenomena are involved in numerous biochemical pathways and play a key role in many pathological events and clinical situations. The oxidation/reduction (redox) state present in biological compartments is a major target for possible pharmaceutical intervention and, consequently, the processes associated with its change have attracted increased attention in recent years. Here, we analyze the redox environment and its spatial compartmentalization in differentiated neuronal phenotype of PC-12 cells using a redox-sensitive protein (i.e., a mutant of the Yellow Fluorescent protein), employed ratiometrically. Redox maps of cells were generated with an elevate spatial resolution, and the spatial distributions of highly oxidized and highly reduced regions have been determined. A quantitative analysis of redox maps allows the disclosure of a peculiar spatial organization of the redox environment.


Asunto(s)
Técnicas Biosensibles , Compartimento Celular/fisiología , Proteínas del Tejido Nervioso/metabolismo , Neuronas/metabolismo , Oxidación-Reducción , Animales , Línea Celular , Células , Microscopía Confocal/métodos , Células PC12 , Ratas
16.
Nanoscale Horiz ; 4(2): 273-290, 2019 03 01.
Artículo en Inglés | MEDLINE | ID: mdl-32254085

RESUMEN

Graphene oxide is the hot topic in biomedical and pharmaceutical research of the current decade. However, its complex interactions with human blood components complicate the transition from the promising in vitro results to clinical settings. Even though graphene oxide is made with the same atoms as our organs, tissues and cells, its bi-dimensional nature causes unique interactions with blood proteins and biological membranes and can lead to severe effects like thrombogenicity and immune cell activation. In this review, we will describe the journey of graphene oxide after injection into the bloodstream, from the initial interactions with plasma proteins to the formation of the "biomolecular corona", and biodistribution. We will consider the link between the chemical properties of graphene oxide (and its functionalized/reduced derivatives), protein binding and in vivo response. We will also summarize data on biodistribution and toxicity in view of the current knowledge of the influence of the biomolecular corona on these processes. Our aim is to shed light on the unsolved problems regarding the graphene oxide corona to build the groundwork for the future development of drug delivery technology.


Asunto(s)
Proteínas Sanguíneas/metabolismo , Grafito/sangre , Adsorción , Animales , Línea Celular Tumoral , Eritrocitos/efectos de los fármacos , Grafito/química , Grafito/metabolismo , Grafito/farmacocinética , Humanos , Macrófagos/efectos de los fármacos , Nanotubos/química , Unión Proteica
17.
J Mech Behav Biomed Mater ; 100: 103377, 2019 12.
Artículo en Inglés | MEDLINE | ID: mdl-31398692

RESUMEN

The umbilical cord is a complex structure containing three vessels, one straight vein and two coiled arteries, encased by the Wharton Jelly (WJ) a spongy structure made of collagen and hydrated macromolecules. Fetal blood reaches the placenta through the arteries and flows back to the fetus through the vein. The role of the WJ in maintaining cord circulation proficiency and the ultimate reason for arterial coiling still lack of reasonable mechanistic interpretations. We performed biaxial tension tests and evidenced significant differences in the mechanical properties of the core and peripheral WJ. The core region, located between the arteries and the vein, resulted rather stiffer close to the fetus. Finite element modelling and optimization based inverse method were used to create 2D and 3D models of the cord and to simulate stress distribution in different hemodynamic conditions, compressive loads and arterial coiling. We recorded a facilitated stress transmission from the arteries to the vein through the soft core of periplacental WJ. This condition generates a pressure gradient that boosts the venous backflow circulation towards the fetus. Peripheral WJ allows arteries to act as pressure buffering chambers during the cardiac diastole and helps to dissipate compressive forces away from vessels. Altered WJ biomechanics may represent the structural basis of cord vulnerability in many high-risk clinical conditions.


Asunto(s)
Fenómenos Biomecánicos , Fuerza Compresiva , Cordón Umbilical/fisiología , Gelatina de Wharton/fisiología , Adulto , Algoritmos , Anisotropía , Colágeno/fisiología , Elasticidad , Femenino , Análisis de Elementos Finitos , Análisis de Fourier , Hemodinámica , Humanos , Imagenología Tridimensional , Sustancias Macromoleculares , Placenta/fisiología , Embarazo , Presión , Estrés Mecánico , Resistencia a la Tracción , Adulto Joven
18.
Interface Focus ; 8(3): 20170059, 2018 Jun 06.
Artículo en Inglés | MEDLINE | ID: mdl-29696091

RESUMEN

Methicillin-resistant Staphylococcus aureus (MRSA) is responsible for serious hospital infections worldwide and represents a global public health problem. Curcumin, the major constituent of turmeric, is effective against MRSA but only at cytotoxic concentrations or in combination with antibiotics. The major issue in curcumin-based therapies is the poor solubility of this hydrophobic compound and the cytotoxicity at high doses. In this paper, we describe the efficacy of a composite nanoparticle made of curcumin (CU) and graphene oxide (GO), hereafter GOCU, in MRSA infection treatment. GO is a nanomaterial with a large surface area and high drug-loading capacity. GO has also antibacterial properties due mainly to a mechanical cutting of the bacterial membranes. For this physical mechanism of action, microorganisms are unlikely to develop resistance against this nanomaterial. In this work, we report the capacity of GO to support and stabilize curcumin molecules in a water environment and we demonstrate the efficacy of GOCU against MRSA at a concentration below 2 µg ml-1. Further, GOCU displays low toxicity on fibroblasts cells and avoids haemolysis of red blood cells. Our results indicate that GOCU is a promising nanomaterial against antibiotic-resistant MRSA.

19.
Phys Med ; 42: 157-161, 2017 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-29173910

RESUMEN

PURPOSE: EPID-based in vivo dosimetry (IVD) has been implemented for stereotactic body radiotherapy treatments of non-small cell lung cancer to check both isocenter dose and the treatment reproducibility comparing EPID portal images. METHODS: 15 patients with lung tumors of small dimensions and treated with volumetric modulated arc therapy were enrolled for this initial experience. IVD tests supplied ratios R between in vivo reconstructed and planned isocenter doses. Moreover a γ-like analysis between daily EPID portal images and a reference one, in terms of percentage of points with γ-value smaller than 1, Pγ<1, and mean γ-values, γmean, using a local 3%-3mm criteria, was adopted to check the treatment reproducibility. Tolerance levels of 5% for R ratio, Pγ<1 higher than 90% and γmean lower than 0.67 were adopted. RESULTS: A total of 160 EPID images, two images for each therapy session, were acquired during the treatment of the 15 patients. The overall mean of the R ratios was equal to 1.005±0.014 (1 SD), with 96.9% of tests within±5%. The 2D image γ-like analysis showed an overall γmean of 0.39±0.12 with 96.1% of tests within the tolerance level, and an average Pγ<1 value equal to 96.4±3.6% with 95.4% of tests with Pγ<1>90%. Paradigmatic discrepancies were observed in three patients: a set-up error and a patient morphological change were identified thanks to CBCT image analysis whereas the third discrepancy was not fully justified. CONCLUSIONS: This procedure can provide improved patient safety as well as a first step to integrate IVD and CBCT dose recalculation.


Asunto(s)
Carcinoma de Pulmón de Células no Pequeñas/radioterapia , Tomografía Computarizada de Haz Cónico/métodos , Dosimetría in Vivo/métodos , Neoplasias Pulmonares/radioterapia , Planificación de la Radioterapia Asistida por Computador/métodos , Radioterapia de Intensidad Modulada/métodos , Carcinoma de Pulmón de Células no Pequeñas/diagnóstico por imagen , Carcinoma de Pulmón de Células no Pequeñas/patología , Tomografía Computarizada Cuatridimensional/métodos , Humanos , Pulmón/diagnóstico por imagen , Pulmón/patología , Pulmón/efectos de la radiación , Neoplasias Pulmonares/diagnóstico por imagen , Neoplasias Pulmonares/patología , Aceleradores de Partículas , Seguridad del Paciente , Traumatismos por Radiación/prevención & control , Dosificación Radioterapéutica , Radioterapia Guiada por Imagen/métodos , Radioterapia de Intensidad Modulada/instrumentación , Respiración , Carga Tumoral
20.
Bioinspir Biomim ; 11(1): 011001, 2016 Feb 04.
Artículo en Inglés | MEDLINE | ID: mdl-26844980

RESUMEN

By mimicking naturally occurring superhydrophobic surfaces, scientists can now realize artificial surfaces on which droplets of a few microliters of water are forced to assume an almost spherical shape and an extremely high contact angle. In recent decades, these surfaces have attracted much attention due to their technological applications for anti-wetting and self-cleaning materials. Very recently, researchers have shifted their interest to investigate whether superhydrophobic surfaces can be exploited to study biological systems. This research effort has stimulated the design and realization of new devices that allow us to actively organize, visualize and manipulate matter at both the microscale and nanoscale levels. Such precise control opens up wide applications in biomedicine, as it allows us to directly manipulate objects at the typical length scale of cells and macromolecules. This progress report focuses on recent biological and medical applications of superhydrophobicity. Particular regard is paid to those applications that involve the detection, manipulation and study of extremely small quantities of molecules, and to those that allow high throughput cell and biomaterial screening.


Asunto(s)
Materiales Biocompatibles/química , Materiales Biomiméticos/química , Interacciones Hidrofóbicas e Hidrofílicas , Agua/química , Humectabilidad
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