Translational investigation in humans and animal models of alcohol use disorders

Alcohol addiction is a health problem that causes millions of deaths worldwide every year. However, the understanding of how alcohol-induced brain alterations lead to addiction remains limited and thus, effective targets for treatment are elusive. The diversity of damage it can cause to the brain has been studied in depth, but is very heterogeneous between individuals. Vulnerability to relapse, which is maximal in the early stages of the disease, remains an unsolved enigma. Typical characteristics of alcoholic patients, such as lack of cognitive control or behavioral inflexibility, could trigger relapse, but little is known about the possible mechanisms underlying them. A significant problem in clinical studies on AUD is the high variability of the results obtained. This variability is partly due to the variety of personal trajectories in alcohol use and abuse and genetic factors, but also to the high number of possible comorbidities associated with alcoholism. These include poly-substance use (tobacco, cannabis, cocaine, etc.) and pharmacological treatments to alleviate the multiple associated symptoms. In this thesis work, I have taken advantage of well-controlled animal models to study the transformations that occur from a control state, naive to alcohol consumption, to excessive consumption and subsequent abstinence. At the same time, several cohorts of humans have been studied, using at all times the same magnetic resonance imaging (MRI) modalities for the study of brain alterations. This design allows to establish causal relationships with alcohol consumption in the animal models, avoiding comorbidities and other confounding factors, without moving away from translation to the clinic (thanks to the convergent set of brain imaging tools used). The first objective was to study the evolution of brain structure during the early phases of abstinence. We used a rat model with a genetic predisposition to consumption, and two cohorts of AUD patients at different times of early abstinence. Brain alterations were studied using diffusion tensor magnetic resonance imaging (DTI), a non-invasive technique with diagnostic value, which informs about water diffusion in tissues. From this information we can infer microstructural alterations. We found that both rats and humans showed comparable microstructural alterations in the white matter (WM) in the early stages of withdrawal. Unexpectedly, we were able to demonstrate that these alterations progressed throughout the period of abstinence studied. Taken together, these findings suggested the existence of an underlying biological process that triggers the progression of WM alterations in the absence of alcohol. In a follow-up study, using the same cohorts of patients, we made a detailed study of the effect size of the alterations found, distinguishing between brain tracts. This study revealed that the most vulnerable tract in alcoholic patients was the fimbria/fornix, which communicates the hippocampus with the prefrontal cortex. Considering that this communication is fundamental for both learning and memory functions, as well as for emotional regulation (together with the amygdala) and cognitive flexibility, we argue that fimbria/fornix dysfunction in the early phase of abstinence could contribute to some key symptoms commonly observed in patients. Consequently, we decided to study in more detail and using again an animal model, the structure and functionality of the fimbria/fornix after alcohol withdrawal. On this occasion, we used a rat model that has demonstrated alcohol dependence, based on wild type animals, known as the postdependent or chronic intermittent exposure model. In addition to diffusion MRI, we used immunohistological and electrophysiological techniques. The results indicated a microstructural alteration in the tract, measured both as a decrease in myelin fraction quantified with MRI, and a decrease in myelin basic protein in postmortem histological examinations. In addition, simultaneous electrophysiological recordings demonstrated reduced efficiency in the directed connectivity from the hippocampus to the prefrontal cortex, together with an increased excitation/inhibition balance in the hippocampus. Taken together, these results suggest that an alcohol-driven mechanism could be damaging the brain microstructure even in the absence of alcohol. Although the underlying mechanism has not been studied, in the case of fimbria/fornix it corresponds to a demyelinating process. The functional consequence of the latter is the partial disconnection of the hippocampus and the prefrontal cortex. We propose that this alteration could be triggering some of the symptoms that characterize alcoholic patients, such as memory deficits and reduced cognitive flexibility, which condemns patients to compulsively repeat behaviors associated with alcohol consumption

The cell density effect in animal cell-based bioprocessing : Questions, insights and perspectives

Altres ajuts: acord transformatiu CRUE-CSICOne of the main challenges in the development of bioprocesses based on cell transient expression is the commonly reported reduction of cell specific productivity at increasing cell densities. This is generally known as the cell density effect (CDE). Many efforts have been devoted to understanding the cell metabolic implications to this phenomenon in an attempt to design operational strategies to overcome it. A comprehensive analysis of the main studies regarding the CDE is provided in this work to better define the elements comprising its cause and impact. Then, examples of methodologies and approaches employed to achieve successful transient expression at high cell densities (HCD) are thoroughly reviewed. A critical assessment of the limitations of the reported studies in the understanding of the CDE is presented, covering the leading hypothesis of the molecular implications. The overall analysis of previous work on CDE may offer useful insights for further research into manufacturing of biologics

The role of extracellular vesicles in the modulation of the cell density effect

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Finding influential nodes for integration in brain networks using optimal percolation theory

Global integration of information in the brain results from complex interactions of segregated brain networks. Identifying the most influential neuronal populations that efficiently bind these networks is a fundamental problem of systems neuroscience. Here we apply optimal percolation theory and pharmacogenetic interventions in-vivo to predict and subsequently target nodes that are essential for global integration of a memory network in rodents. The theory predicts that integration in the memory network is mediated by a set of low-degree nodes located in the nucleus accumbens. This result is confirmed with pharmacogenetic inactivation of the nucleus accumbens, which eliminates the formation of the memory network, while inactivations of other brain areas leave the network intact. Thus, optimal percolation theory predicts essential nodes in brain networks. This could be used to identify targets of interventions to modulate brain function.Comment: 20 pages, 6 figures, Supplementary Inf

La industria lítica del yacimiento achelense de Torralba (Soria, España). Colecciones marqués de Cerralbo y Howell

Torralba is a Middle Pleistocene site, with absolute dates that place it in MIS 7. Its lithic industry comes from fluvial levels and is situated in a secondary position. The raw materials were brought to the site from sources located several tens kilometers away. The techno-economic study of the industrial series obtained in the excavations conducted by Marquis of Cerralbo (1909-1913) and Clark Howell (1961-1963), confirms the Acheulean identity of this industry. Production, configuration and maintenance of the industry were all carried out at the site, although at least some macro-tools were introduced already elaborated. We have identified unusual technological aspects in the context of the European Acheulean, for example the frequent use of flint in developing cleavers.Torralba es un yacimiento del Pleistoceno medio, con dataciones numéricas que le sitúan en el MIS 7 (191/243 ka). Su industria, que procede de niveles fluviales y se encuentra fundamentalmente en posición secundaria, fue elaborada sobre materias primas introducidas desde distancias que pueden alcanzar varias decenas de kilómetros. El estudio tecno-económico de las series industriales obtenidas en las excavaciones realizadas por el marqués de Cerralbo (1909-1913) y Clark Howell (1961-1963) confirma la identidad achelense de la industria y la realización de procesos de producción, configuración y mantenimiento en el yacimiento, aunque al menos una parte del macroutillaje fue introducida ya configurada en el mismo. Se identifican aspectos tecnológicos singulares en el contexto del achelense europeo, como el uso frecuente del sílex en la elaboración de hendedores

Finding influential nodes for integration in brain networks using optimal percolation theory

Global integration of information in the brain results from complex interactions of segregated brain networks. Identifying the most influential neuronal populations that efficiently bind these networks is a fundamental problem of systems neuroscience. Here, we apply optimal percolation theory and pharmacogenetic interventions in vivo to predict and subsequently target nodes that are essential for global integration of a memory network in rodents. The theory predicts that integration in the memory network is mediated by a set of low-degree nodes located in the nucleus accumbens. This result is confirmed with pharmacogenetic inactivation of the nucleus accumbens, which eliminates the formation of the memory network, while inactivations of other brain areas leave the network intact. Thus, optimal percolation theory predicts essential nodes in brain networks. This could be used to identify targets of interventions to modulate brain function

Stigmatization is common in patients with non-alcoholic fatty liver disease and correlates with quality of life

Background and aims: Stigmatization is a well-documented problem of some diseases. Perceived stigma is common in alcohol-related liver disease and hepatitis C, but little information exists on stigma in patients with non-alcoholic fatty liver disease (NAFLD). Aim of the study was to investigate frequency and characteristics of perceived stigma among patients with NAFLD. Methods: One-hundred and ninety-seven patients seen at the liver clinic were included: a study group of 144 patients with NAFLD, 50 with cirrhosis (34 compensated, 16 decompensated), and a control group of 53 patients with alcohol-related cirrhosis. Demographic, clinical, and laboratory data were collected. Quality-of-life was assessed by chronic liver disease questionnaire (CLDQ). Perceived stigma was assessed using a specific questionnaire for patients with liver diseases categorized in 4 domains: stereotypes, discrimination, shame, and social isolation. Results: Perceived stigma was common in patients with NAFLD (99 patients, 69%) and affected all 4 domains assessed. The frequency was slightly higher, yet not significant, in patients with NAFLD cirrhosis vs those without (72% vs 67%, respectively; p = 0.576). In patients without cirrhosis perceived stigma was unrelated to stage of disease, since frequency was similar in patients with no or mild fibrosis compared to those with moderate/severe fibrosis (66% vs 68%, respectively). There were no differences in perceived stigma between patients with compensated cirrhosis and these with decompensated cirrhosis. Among patients with cirrhosis, stigmatization was more common in alcohol-related vs NAFLD-cirrhosis, yet differences were only significant in two domains. In patients with NAFLD, perceived stigma correlated with poor quality-of-life, but not with demographic or clinical variables. Conclusions: Perceived stigmatization is common among patients with NAFLD independently of disease stage, is associated with impaired quality-of-life, and may be responsible for stereotypes, discrimination, shame, and social isolation, which may affect human and social rights of affected patients

Effect of different housing systems (single and group penning) on the health and welfare of commercial female rabbits

In recent decades, concern about rabbit welfare and sustainability has increased. The housing system is a very important factor for animal welfare. However, information about how different available housing types for female rabbits affect their health status is scarce, but this is an important factor for their welfare. Hence, the objective of this study was to evaluate the health status of female rabbits in five common housing systems: three different single-housing systems with distinct available surfaces and heights; a single-housing system with a platform; a collective system. Female rabbits in the collective and platform cages had greater cortisol concentrations in hair than those in the single-housing system with no platform. Haptoglobin concentrations and kit mortality rates during lactation were greater for the collective-cage female rabbits. The collective group had more culled females and more lesions than in the other groups. The main reasons for culling in all the groups were reproduction problems and presence of abscesses, and the collective group of females was the most affected. In conclusion, it appears that keeping females together in collective systems negatively affects their health status and welfare, while single-housing systems imply lower kit mortality rates during lactation and cortisol concentrations, and fewer lesions in female rabbits

Post-Hospital Syndrome and Hyponatremia

Introduction: Post-hospital syndrome (PHS) is defined as a period of vulnerability during the first 30 days after a patient is discharged from hospital, in which multiple factors come into play. Hyponatremia is the most frequent hydroelectrolytic disorder in hospitalized patients and may be related to the appearance of PHS. Objective: The objective is to estimate the prevalence of PHS that is assessed as the rate of readmissions in the first 30 days after discharge, in patients with hyponatremia. Material and Methods: It is a descriptive observational study of patients with hyponatremia who were discharged from 1 September 2010 to 2 February 2020 at the Internal Medicine Service of the Hospital University of San Juan (Alicante, Spain). Results: Of the 25 included patients, 5 (20%) were readmitted within a month of discharge, after a mean of 11.4 days (standard deviation [SD] 5.1). The overall mortality of the study was 20% (n = 5), with one case of death in the first 30 days post-hospitalization (4%). In 12 patients (48%) the origin of the hyponatremia was undetermined. The most frequently recorded etiology for the condition was pharmacological (n = 7, 28%), and there was pronounced variability in its clinical and laboratory study. The most widely used corrective measure was drug withdrawal, in 16 patients (64%). Water intake restriction was the most common treatment after discharge (5 patients, 20%), followed by urea (2 patients, 8%), while tolvaptan was not used. Conclusion: Hyponatremia may be the cause of PHS, which could increase the rate of early readmission. Hyponatremia is an underdiagnosed and undertreated entity, so it is necessary to apply an appropriate system to optimize its management and, in future studies, to assess its impact on PHS