DONATE

Publications

by Keyword: Humans

F Amil A, Rubio Ballester B, Maier M, FMJ Verschure P, (2022). Chronic use of cannabis might impair sensory error processing in the cerebellum through endocannabinoid dysregulation Addictive Behaviors 131, 107297

Chronic use of cannabis leads to both motor deficits and the downregulation of CB1 receptors (CB1R) in the cerebellum. In turn, cerebellar damage is often related to impairments in motor learning and control. Further, a recent motor learning task that measures cerebellar-dependent adaptation has been shown to distinguish well between healthy subjects and chronic cannabis users. Thus, the deteriorating effects of chronic cannabis use in motor performance point to cerebellar adaptation as a key process to explain such deficits. We review the literature relating chronic cannabis use, the endocannabinoid system in the cerebellum, and different forms of cerebellar-dependent motor learning, to suggest that CB1R downregulation leads to a generalized underestimation and misprocessing of the sensory errors driving synaptic updates in the cerebellar cortex. Further, we test our hypothesis with a computational model performing a motor adaptation task and reproduce the behavioral effect of decreased implicit adaptation that appears to be a sign of chronic cannabis use. Finally, we discuss the potential of our hypothesis to explain similar phenomena related to motor impairments following chronic alcohol dependency. © 2022

JTD Keywords: adaptation, addiction, alcohol-abuse, cerebellum, cognition, deficits, endocannabinoid system, error processing, explicit, modulation, motor learning, release, synaptic plasticity, Adaptation, Adaptation, physiological, Alcoholism, Article, Behavioral science, Cannabinoid 1 receptor, Cannabis, Cannabis addiction, Cerebellum, Cerebellum cortex, Cerebellum disease, Chronic cannabis use, Computer model, Down regulation, Endocannabinoid, Endocannabinoid system, Endocannabinoids, Error processing, Hallucinogens, Human, Humans, Motor dysfunction, Motor learning, Nerve cell plasticity, Nonhuman, Physiology, Psychedelic agent, Purkinje-cells, Regulatory mechanism, Sensation, Sensory dysfunction, Sensory error processing impairment, Synaptic transmission, Task performance


Marte L, Boronat S, Barrios R, Barcons-Simon A, Bolognesi B, Cabrera M, Ayté J, Hidalgo E, (2022). Expression of Huntingtin and TDP-43 Derivatives in Fission Yeast Can Cause Both Beneficial and Toxic Effects International Journal Of Molecular Sciences 23, 3950

Many neurodegenerative disorders display protein aggregation as a hallmark, Huntingtin and TDP-43 aggregates being characteristic of Huntington disease and amyotrophic lateral sclerosis, respectively. However, whether these aggregates cause the diseases, are secondary by-products, or even have protective effects, is a matter of debate. Mutations in both human proteins can modulate the structure, number and type of aggregates, as well as their toxicity. To study the role of protein aggregates in cellular fitness, we have expressed in a highly tractable unicellular model different variants of Huntingtin and TDP-43. They each display specific patterns of aggregation and toxicity, even though in both cases proteins have to be very highly expressed to affect cell fitness. The aggregation properties of Huntingtin, but not of TDP-43, are affected by chaperones such as Hsp104 and the Hsp40 couple Mas5, suggesting that the TDP-43, but not Huntingtin, derivatives have intrinsic aggregation propensity. Importantly, expression of the aggregating form of Huntingtin causes a significant extension of fission yeast lifespan, probably as a consequence of kidnapping chaperones required for maintaining stress responses off. Our study demonstrates that in general these prion-like proteins do not cause toxicity under normal conditions, and in fact they can protect cells through indirect mechanisms which up-regulate cellular defense pathways. © 2022 by the authors. Licensee MDPI, Basel, Switzerland.

JTD Keywords: Chaperone, Chemistry, Dna binding protein, Dna-binding proteins, Fission yeast, Genetics, Human, Humans, Huntingtin, Metabolism, Molecular chaperones, Neurodegenerative diseases, Prion, Prions, Protein aggregate, Protein aggregates, Protein aggregation, Schizosaccharomyces, Tdp-43


Boda, SK, Aparicio, C, (2022). Dual keratinocyte-attachment and anti-inflammatory coatings for soft tissue sealing around transmucosal oral implants Biomaterials Science 10, 665-677

Unlike the attachment of soft epithelial skin tissue to penetrating solid natural structures like fingernails and teeth, sealing around percutaneous/permucosal devices such as dental implants is hindered by inflammation and epidermal down growth. Here, we employed a dual keratinocyte-adhesive peptide and anti-inflammatory biomolecule coating on titanium to promote oral epithelial tissue attachment. For minimizing inflammation-triggered epidermal down growth, we coated pristine and oxygen plasma pre-treated polished titanium (pTi) with conjugated linoleic acid (CLA). Further, in order to aid in soft tissue attachment via the formation of hemidesmosomes, adhesive structures by oral keratinocytes, we coated the anionic linoleic acid (LA) adsorbed titanium with cationic cell adhesive peptides (CAP), LamLG3, a peptide derived from Laminin 332, the major extracellular matrix component of the basement membrane in skin tissue and Net1, derived from Netrin-1, a neural chemoattractant capable of epithelial cell attachment via alpha 6 beta 4 integrins. The dual CLA-CAP coatings on pTi were characterized by X-ray photoelectron spectroscopy and dynamic water contact angle measurements. The proliferation of human oral keratinocytes (TERT-2/OKF6) was accelerated on the peptide coated titanium while also promoting the expression of Col XVII and beta-4 integrin, two markers for hemidesmosomes. Simultaneously, CLA coating suppressed the production of inducible nitric oxide synthase (anti-iNOS); a pro-inflammatory M1 marker expressed in lipopolysaccharide (LPS) stimulated murine macrophages (RAW 264.7) and elevated expression of anti-CD206, associated to an anti-inflammatory M2 macrophage phenotype. Taken together, the dual keratinocyte-adhesive peptide and anti-inflammatory biomolecule coating on titanium can help reduce inflammation and promote permucosal/peri-implant soft tissue sealing.

JTD Keywords: Adhesives, Animal, Animals, Anti-inflammatories, Anti-inflammatory agents, Antiinflammatory agent, Biomolecules, Bone, Cell adhesion, Cell-adhesives, Coatings, Conjugated linoleic acid, Conjugated linoleic-acid, Contact angle, Hemidesmosome, Hemidesmosomes, Human, Humans, Hydroxyapatite, Inflammation, Integrins, Keratinocyte, Keratinocytes, Linoleic acid, Macrophages, Mice, Mouse, Nitric oxide, Oral implants, Pathology, Peptides, Skin tissue, Soft tissue, Supplementation, Surface properties, Surface property, Tissue, Titania, Titanium, X ray photoelectron spectroscopy


Rodriguez J, Schulz S, Voss A, Giraldo BF, (2021). Classification of ischemic and dilated cardiomyopathy patients based on the analysis of the pulse transit time Conference Proceedings : ... Annual International Conference Of The Ieee Engineering In Medicine And Biology Society. Ieee Engineering In Medicine And Biology Society. Conference , 5527-5530

Cardiomyopathies diseases affects a great number of the elderly population. An adequate identification of the etiology of a cardiomyopathy patient is still a challenge. The aim of this study was to classify patients by their etiology in function of indexes extracted from the characterization of the pulse transit time (PTT). This time series represents the time taken by the pulse pressure to propagate through the length of the arterial tree and corresponding to the time between R peak of ECG and the mid-point of the diastolic to systolic slope in the blood pressure signal. For each patient, the PTT time series was extracted. Thirty cardiomyopathy patients (CMP) classified as ischemic (ICM - 15 patients) and dilated (DCM - 15 patients) were analyzed. Forty-three healthy subjects (CON) were used as a reference. The PTT time series was characterized through statistical descriptive indices and the joint symbolic dynamics method. The best indices were used to build support vector machine models. The optimal model to classify ICM versus DCM patients achieved 89.6% accuracy, 78.5% sensitivity, and 100% specificity. When comparing CMP patients and CON subjects, the best model achieved 91.3% accuracy, 91.3% sensitivity, and 88.3% specificity. Our results suggests a significantly lower pulse transit time in ischemic patients.Clinical relevance - This study analyzed the suitability of the pulse transit time for the classification of ICM and DCM patients. © 2021 IEEE.

JTD Keywords: Aged, Blood pressure, Cardiomyopathies, Cardiomyopathy, Cardiomyopathy, dilated, Congestive cardiomyopathy, Human, Humans, Pulse wave, Pulse wave analysis, Support vector machine


Arboleda A, Amado L, Rodriguez J, Naranjo F, Giraldo BF, (2021). A new protocol to compare successful versus failed patients using the electromyographic diaphragm signal in extubation process Conference Proceedings : ... Annual International Conference Of The Ieee Engineering In Medicine And Biology Society. Ieee Engineering In Medicine And Biology Society. Conference , 5646-5649

In clinical practice, when a patient is undergoing mechanical ventilation, it is important to identify the optimal moment for extubation, minimizing the risk of failure. However, this prediction remains a challenge in the clinical process. In this work, we propose a new protocol to study the extubation process, including the electromyographic diaphragm signal (diaEMG) recorded through 5-channels with surface electrodes around the diaphragm muscle. First channel corresponds to the electrode on the right. A total of 40 patients in process of withdrawal of mechanical ventilation, undergoing spontaneous breathing tests (SBT), were studied. According to the outcome of the SBT, the patients were classified into two groups: successful (SG: 19 patients) and failure (FG: 21 patients) groups. Parameters extracted from the envelope of each channel of diaEMG in time and frequency domain were studied. After analyzing all channels, the second presented maximum differences when comparing the two groups of patients, with parameters related to root mean square (p = 0.005), moving average (p = 0.001), and upward slope (p = 0.017). The third channel also presented maximum differences in parameters as the time between maximum peak (p = 0.004), and the skewness (p = 0.027). These results suggest that diaphragm EMG signal could contribute to increase the knowledge of the behaviour of respiratory system in these patients and improve the extubation process.Clinical Relevance - This establishes the characterization of success and failure patients in the extubation process. © 2021 IEEE.

JTD Keywords: Airway extubation, Artificial ventilation, Clinical practices, Clinical process, Diaphragm, Diaphragm muscle, Diaphragms, Electrodes, Electromyographic, Extubation, Frequency domain analysis, Human, Humans, Maximum differences, Mechanical ventilation, New protocol, Respiration, artificial, Respiratory system, Risk of failure, Spontaneous breathing, Surface electrode, Thorax, Ventilation, Ventilator weaning


Fernandez, Javier G., Mills, C. A., Samitier, J., (2009). Complex microstructured 3D surfaces using chitosan biopolymer Small 5, (5), 614-620

A technique for producing micrometer-scale structures over large, nonplanar chitosan surfaces is described. The technique makes use of the rheological characteristics (deformability) of the chitosan to create freestanding, three-dimensional scaffolds with controlled shapes, incorporating defined microtopography. The results of an investigation into the technical limits of molding different combinations of shapes and microtopographies are presented, highlighting the versatility of the technique when used irrespectively with inorganic or delicate organic moulds. The final, replicated scaffolds presented here are patterned with arrays of one-micrometer-tall microstructures over large areas. Structural integrity is characterized by the measurement of structural degradation. Human umbilical vein endothelial cells cultured on a tubular scaffold show that early cell growth is conditioned by the microtopography and indicate possible uses for the structures in biomedical applications. For those applications requiring improved chemical and mechanical resistance, the structures can be replicated in poly(dimethyl siloxane).

JTD Keywords: Biocompatible Materials/ chemistry, Cell Adhesion, Cell Culture Techniques/ methods, Cell Proliferation, Cells, Cultured, Chitosan/ chemistry, Crystallization/methods, Endothelial Cells/ cytology/ physiology, Humans, Materials Testing, Nanostructures/ chemistry/ ultrastructure, Nanotechnology/methods, Particle Size, Surface Properties, Tissue Engineering/methods


Engel, E., Michiardi, A., Navarro, M., Lacroix, D., Planell, J. A., (2008). Nanotechnology in regenerative medicine: the materials side Trends in Biotechnology , 26, (1), 39-47

Regenerative medicine is an emerging multidisciplinary field that aims to restore, maintain or enhance tissues and hence organ functions. Regeneration of tissues can be achieved by the combination of living cells, which will provide biological functionality, and materials, which act as scaffolds to support cell proliferation. Mammalian cells behave in vivo in response to the biological signals they receive from the surrounding environment, which is structured by nanometre-scaled components. Therefore, materials used in repairing the human body have to reproduce the correct signals that guide the cells towards a desirable behaviour. Nanotechnology is not only an excellent tool to produce material structures that mimic the biological ones but also holds the promise of providing efficient delivery systems. The application of nanotechnology to regenerative medicine is a wide issue and this short review will only focus on aspects of nanotechnology relevant to biomaterials science. Specifically, the fabrication of materials, such as nanoparticles and scaffolds for tissue engineering, and the nanopatterning of surfaces aimed at eliciting specific biological responses from the host tissue will be addressed.

JTD Keywords: Animals, Biocompatible Materials/ metabolism, Humans, Nanoparticles, Nanotechnology/ methods, Regenerative Medicine/ methods, Tissue Scaffolds


Engel, E., Del Valle, S., Aparicio, C., Altankov, G., Asin, L., Planell, J. A., Ginebra, M. P., (2008). Discerning the role of topography and ion exchange in cell response of bioactive tissue engineering scaffolds Tissue Engineering Part A , 14, (8), 1341-1351

Surface topography is known to have an influence on osteoblast activity. However, in the case of bioactive materials, topographical changes can affect also ion exchange properties. This makes the problem more complex, since it is often difficult to separate the strictly topographical effects from the effects of ionic fluctuations in the medium. The scope of this paper is to analyze the simultaneous effect of topography and topography-mediated ion exchange on the initial cellular behavior of osteoblastic-like cells cultured on bioactive tissue engineering substrates. Two apatitic substrates with identical chemical composition but different micro/nanostructural features were obtained by low-temperature setting of a calcium phosphate cement. MG63 osteoblastic-like cells were cultured either in direct contact with the substrates or with their extracts. A strong and permanent decrease of calcium concentration in the culture medium, dependent on substrate topography, was detected. A major effect of the substrate microstructure on cell proliferation was observed, explained in part by the topography-mediated ion exchange, but not specifically by the ionic Ca(2+) fluctuations. Cell differentiation was strongly enhanced when cells were cultured on the finer substrate. This effect was not explained by the chemical modification of the medium, but rather suggested a strictly topographical effect.

JTD Keywords: Alkaline Phosphatase/metabolism, Bone Cements/pharmacology, Calcium/metabolism, Calcium Phosphates/pharmacology, Cell Adhesion/drug effects, Cell Differentiation/drug effects, Cell Proliferation/drug effects, Cell Shape/drug effects, Cells, Cultured, Culture Media, Durapatite/pharmacology, Humans, Interferometry, Ion Exchange, Materials Testing, Osteoblasts/ cytology/drug effects/enzymology/ultrastructure, Phosphorus/metabolism, Powders, Tissue Engineering, Tissue Scaffolds


Gavara, N., Roca-Cusachs, P., Sunyer, R., Farre, R., Navajas, D., (2008). Mapping cell-matrix stresses during stretch reveals inelastic reorganization of the cytoskeleton Biophysical Journal , 95, (1), 464-471

The mechanical properties of the living cell are intimately related to cell signaling biology through cytoskeletal tension. The tension borne by the cytoskeleton (CSK) is in part generated internally by the actomyosin machinery and externally by stretch. Here we studied how cytoskeletal tension is modified during stretch and the tensional changes undergone by the sites of cell-matrix interaction. To this end we developed a novel technique to map cell-matrix stresses during application of stretch. We found that cell-matrix stresses increased with imposition of stretch but dropped below baseline levels on stretch release. Inhibition of the actomyosin machinery resulted in a larger relative increase in CSK tension with stretch and in a smaller drop in tension after stretch release. Cell-matrix stress maps showed that the loci of cell adhesion initially bearing greater stress also exhibited larger drops in traction forces after stretch removal. Our results suggest that stretch partially disrupts the actin-myosin apparatus and the cytoskeletal structures that support the largest CSK tension. These findings indicate that cells use the mechanical energy injected by stretch to rapidly reorganize their structure and redistribute tension.

JTD Keywords: Cell Line, Computer Simulation, Cytoskeleton/ physiology, Elasticity, Epithelial Cells/ physiology, Extracellular Matrix/ physiology, Humans, Mechanotransduction, Cellular/ physiology, Models, Biological, Stress, Mechanical


Roca-Cusachs, P., Alcaraz, J., Sunyer, R., Samitier, J., Farre, R., Navajas, D., (2008). Micropatterning of single endothelial cell shape reveals a tight coupling between nuclear volume in G1 and proliferation Biophysical Journal , 94, (12), 4984-4995

Shape-dependent local differentials in cell proliferation are considered to be a major driving mechanism of structuring processes in vivo, such as embryogenesis, wound healing, and angiogenesis. However, the specific biophysical signaling by which changes in cell shape contribute to cell cycle regulation remains poorly understood. Here, we describe our study of the roles of nuclear volume and cytoskeletal mechanics in mediating shape control of proliferation in single endothelial cells. Micropatterned adhesive islands were used to independently control cell spreading and elongation. We show that, irrespective of elongation, nuclear volume and apparent chromatin decondensation of cells in G1 systematically increased with cell spreading and highly correlated with DNA synthesis (percent of cells in the S phase). In contrast, cell elongation dramatically affected the organization of the actin cytoskeleton, markedly reduced both cytoskeletal stiffness (measured dorsally with atomic force microscopy) and contractility (measured ventrally with traction microscopy), and increased mechanical anisotropy, without affecting either DNA synthesis or nuclear volume. Our results reveal that the nuclear volume in G1 is predictive of the proliferative status of single endothelial cells within a population, whereas cell stiffness and contractility are not. These findings show that the effects of cell mechanics in shape control of proliferation are far more complex than a linear or straightforward relationship. Our data are consistent with a mechanism by which spreading of cells in G1 partially enhances proliferation by inducing nuclear swelling and decreasing chromatin condensation, thereby rendering DNA more accessible to the replication machinery.

JTD Keywords: Cell Line, Cell Nucleus/ physiology, Cell Proliferation, Cell Size, Computer Simulation, Endothelial Cells/ cytology/ physiology, G1 Phase/ physiology, Humans, Mechanotransduction, Cellular/ physiology, Models, Biological, Statistics as Topic


Charles-Harris, M., Koch, M. A., Navarro, M., Lacroix, D., Engel, E., Planell, J. A., (2008). A PLA/calcium phosphate degradable composite material for bone tissue engineering: an in vitro study Journal of Materials Science-Materials in Medicine , 19, (4), 1503-1513

Biodegradable polymers reinforced with an inorganic phase such as calcium phosphate glasses may be a promising approach to fulfil the challenging requirements presented by 3D porous scaffolds for tissue engineering. Scaffolds' success depends mainly on their biological behaviour. This work is aimed to the in vitro study of polylactic acid (PLA)/CaP glass 3D porous constructs for bone regeneration. The scaffolds were elaborated using two different techniques, namely solvent-casting and phase-separation. The effect of scaffolds' micro and macrostructure on the biological response of these scaffolds was assayed. Cell proliferation, differentiation and morphology within the scaffolds were studied. Furthermore, polymer/glass scaffolds were seeded under dynamic conditions in a custom-made perfusion bioreactor. Results indicate that the final architecture of the solvent-cast or phase separated scaffolds have a significant effect on cells' behaviour. Solvent-cast scaffolds seem to be the best candidates for bone tissue engineering. Besides, dynamic seeding yielded a higher seeding efficiency in comparison with the static method.

JTD Keywords: Biocompatible Materials/ chemistry, Bone and Bones/ metabolism, Calcium Phosphates/ chemistry, Cell Differentiation, Cell Proliferation, Humans, Lactic Acid/ chemistry, Microscopy, Confocal, Microscopy, Electron, Scanning, Osteoblasts/metabolism, Permeability, Polymers/ chemistry, Porosity, Solvents/chemistry, Tissue Engineering/ methods


Gustavsson, J., Altankov, G., Errachid, A., Samitier, J., Planell, J. A., Engel, E., (2008). Surface modifications of silicon nitride for cellular biosensor applications Journal of Materials Science-Materials in Medicine , 19, (4), 1839-1850

Thin films of silicon nitride (Si3N4) can be used in several kinds of micro-sized biosensors as a material to monitor fine environmental changes related to the process of bone formation in vitro. We found however that Si3N4 does not provide optimal conditions for osseointegration as osteoblast-like MG-63 cells tend to detach from the surface when cultured over confluence. Therefore Si3N4 was modified with self-assembled monolayers bearing functional end groups of primary amine (NH2) and carboxyl (COOH) respectively. Both these modifications enhanced the interaction with confluent cell layers and thus improve osseointegration over Si3N4. Furthermore it was observed that the NH2 functionality increased the adsorption of fibronectin (FN), promoted cell proliferation, but delayed the differentiation. We also studied the fate of pre-adsorbed and secreted FN from cells to learn more about the impact of above functionalities for the development of provisional extracellular matrix on materials interface. Taken together our data supports that Si3N4 has low tissue integration but good cellular biocompatibility and thus is appropriate in cellular biosensor applications such as the ion-sensitive field effect transistor (ISFET). COOH and NH2 chemistries generally improve the interfacial tissue interaction with the sensor and they are therefore suitable substrates for monitoring cellular growth or matrix deposition using electrical impedance spectroscopy.

JTD Keywords: Adsorption, Amines/chemistry, Biocompatible Materials/ chemistry, Biosensing Techniques, Cell Differentiation, Cell Line, Cell Proliferation, Electric Impedance, Extracellular Matrix/metabolism, Fibronectins/chemistry, Humans, Materials Testing, Osteoblasts/ cytology, Silicon Compounds/ chemistry, Surface Properties


Diez, Pablo F., Laciar, Eric, Mut, Vicente, Avila, Enrique, Torres, Abel, (2008). A comparative study of the performance of different spectral estimation methods for classification of mental tasks IEEE Engineering in Medicine and Biology Society Conference Proceedings 30th Annual International Conference of the Ieee Engineering in Medicine and Biology Society (ed. IEEE), IEEE (Vancouver, Canada) 1-8, 1155-1158

In this paper we compare three different spectral estimation techniques for the classification of mental tasks. These techniques are the standard periodogram, the Welch periodogram and the Burg method, applied to electroencephalographic (EEG) signals. For each one of these methods we compute two parameters: the mean power and the root mean square (RMS), in various frequency bands. The classification of the mental tasks was conducted with a linear discriminate analysis. The Welch periodogram and the Burg method performed better than the standard periodogram. The use of the RMS allows better classification accuracy than the obtained with the power of EEG signals.

JTD Keywords: Adult, Algorithms, Artificial Intelligence, Cognition, Electroencephalography, Female, Humans, Male, Pattern Recognition, Automated, Reproducibility of Results, Sensitivity and Specificity, Task Performance and Analysis, User-Computer Interface


Orini, Michele, Giraldo, Beatriz F., Bailon, Raquel, Vallverdu, Montserrat, Mainardi, Luca, Benito, Salvador, Diaz, Ivan, Caminal, Pere, (2008). Time-frequency analysis of cardiac and respiratory parameters for the prediction of ventilator weaning IEEE Engineering in Medicine and Biology Society Conference Proceedings 30th Annual International Conference of the IEEE Engineering in Medicine and Biology Society (ed. IEEE), IEEE (Vancouver, Canada) 1-8, 2793-2796

Mechanical ventilators are used to provide life support in patients with respiratory failure. Assessing autonomic control during the ventilator weaning provides information about physiopathological imbalances. Autonomic parameters can be derived and used to predict success in discontinuing from the mechanical support. Time-frequency analysis is used to derive cardiac and respiratory parameters, as well as their evolution in time, during ventilator weaning in 130 patients. Statistically significant differences have been observed in autonomic parameters between patients who are considered ready for spontaneous breathing and patients who are not. A classification based on respiratory frequency, heart rate and heart rate variability spectral components has been proposed and has been able to correctly classify more than 80% of the cases.

JTD Keywords: Automatic Data Processing, Databases, Factual, Electrocardiography, Humans, Models, Statistical, Respiration, Respiration, Artificial, Respiratory Insufficiency, Respiratory Mechanics, Respiratory Muscles, Signal Processing, Computer-Assisted, Time Factors, Ventilator Weaning, Ventilators, Mechanical, Work of Breathing