ABSTRACT
Due to the increased incidence of obesity, it is of great importance to identify all the possible consequences in those who suffer from it and their descendants. This study aimed to investigate how paternal obesity, resulting from an 18-week high-fat diet (HFD), affects the metabolic and reproductive health of offspring. In the fathers (F0 generation), the HFD led to significant weight gain, primarily due to increased visceral fat. It also resulted in impaired glucose control and reduced insulin sensitivity. Furthermore, F0 males from the HFD group had reduced sperm concentration and lower sperm viability but were still able to sire litters. F1 offspring were monitored during 18 weeks; F1 offspring from obese fathers displayed increased body weight during the experimental window, especially in males, without significant metabolic disturbances. Additionally, F1 males showed reduced sperm viability, indicating potential reproductive implications. On the other hand, F1 females showed normal estrous cycle patterns but had a reduced number of primordial follicles, suggesting a decrease in their follicular reserve and reproductive potential. This study highlights that metabolic and reproductive issues may be passed down to future generations through the paternal line.
ABSTRACT
Introduction: Obesity consists in the accumulation of adipose tissue accompanied by low grade chronic inflammation and is considered a pandemic disease. Recent studies have observed that obesity affects females and males in a sex-dependent manner. In addition, several works have demonstrated that parental obesity increases the risk to develop obesity, insulin resistance, diabetes, and reproductive disorders. Considering that intergenerational effects of obesity may occur in a sex-dependent manner, we studied male Wistar rat progeny (F1) obtained from mothers or fathers (F0) fed on a high-fat diet (HFD). Methods: Five-week-old female and male Wistar rats were fed on a HFD (with 60% of calories provided by fat) for 18 weeks (F0). At the end of the treatment, animals were mated with young rats to obtain their progeny (F1). After weaning, F1 animals were fed on standard chow until 18 weeks of age. Body weight gain, fasting plasma glucose, insulin and leptin levels, glucose tolerance, insulin sensitivity, and adiposity were evaluated. In addition, beta-cell expression of nuclear p16 was assessed by immunofluorescence. Results and conclusions: HFD altered plasma fasting glucose, insulin and leptin levels, glucose tolerance, adiposity, and beta-cell expression of p16 in F0 rats. Particularly, HFD showed sexual dimorphic effects on body weight gain and insulin sensitivity. Moreover, we observed that parental HFD feeding exerts parental-sex-specific metabolic impairment in the male progeny. Finally, parental metabolic dysfunction could be in part attributed to the increased beta-cell expression of p16; other mechanisms could be involved in the offspring glucose homeostasis.
Subject(s)
Insulin Resistance , Leptin , Rats , Male , Female , Animals , Diet, High-Fat/adverse effects , Rats, Wistar , Obesity/metabolism , Weight Gain , Insulin/metabolism , Glucose , HomeostasisABSTRACT
Light at night is an emergent problem for modern society. Rodents exposed to light at night develop a loss of circadian rhythms, which leads to increased adiposity, altered immune response, and increased growth of tumors. In female rats, constant light (LL) eliminates the estrous cycle leading to a state of persistent estrus. The suprachiasmatic nucleus (SCN) drives circadian rhythms, and it interacts with the neuroendocrine network necessary for reproductive function. Timed restricted feeding (RF) exerts a powerful entraining influence on the circadian system, and it can influence the SCN activity and can restore rhythmicity or accelerate re-entrainment in experimental conditions of shift work or jet lag. The present study explored RF in female rats exposed to LL, with the hypothesis that this cyclic condition can rescue or prevent the loss of daily rhythms and benefit the expression of the estrous cycle. Two different feeding schedules were explored: 1. A 12-h food/12-h fasting schedule applied to arrhythmic rats after 3 weeks in LL, visualized as a rescue strategy (LL + RFR, 3 weeks), or applied simultaneously with the first day of LL as a preventive strategy (LL + RFP, 6 weeks). 2. A 12-h window of food intake with food given in four distributed pulses (every 3 h), applied after 3 weeks in LL, as a rescue strategy (LL + PR, 3 weeks) or applied simultaneously with the first day of LL as a preventive strategy (LL + PP, 6 weeks). Here, we present evidence that scheduled feeding can drive daily rhythms of activity and temperature in rats exposed to LL. However, the protocol of distributed feeding pulses was more efficient to restore the day-night activity and core temperature as well as the c-Fos day-night change in the SCN. Likewise, the distributed feeding partially restored the estrous cycle and the ovary morphology under LL condition. Data here provided indicate that the 12-h feeding/12-h fasting window determines the rest-activity cycle and can benefit directly the circadian and reproductive function. Moreover, this effect is stronger when food is distributed along the 12 h of subjective night.
ABSTRACT
In this work, electroluminescence in Metal-Insulator-Semiconductors (MIS) and Metal-Insulator-Metal (MIM)-type structures was studied. These structures were fabricated with single- and double-layer silicon-rich-oxide (SRO) films by means of Hot Filament Chemical Vapor Deposition (HFCVD), gold and indium tin oxide (ITO) were used on silicon and quartz substrates as a back and front contact, respectively. The thickness, refractive indices, and excess silicon of the SRO films were analyzed. The behavior of the MIS and MIM-type structures and the effects of the pristine current-voltage (I-V) curves with high and low conduction states are presented. The structures exhibit different conduction mechanisms as the Ohmic, Poole-Frenkel, Fowler-Nordheim, and Hopping that contribute to carrier transport in the SRO films. These conduction mechanisms are related to the electroluminescence spectra obtained from the MIS and MIM-like structures with SRO films. The electroluminescence present in these structures has shown bright dots in the low current of 36 uA with a voltage of -20 V to -50 V. However, when applied voltages greater than -67 V with 270 uA, a full area with uniform blue light emission is shown.
ABSTRACT
Pineal parenchymal tumors are rare neoplasms, ranging from WHO Grade I to IV. There are few studies characterizing the molecular profiles of these tumors. ATRX alterations are strongly associated with the presence of the alternative lengthening of telomeres (ALT) phenotype, and within the central nervous system they tend to occur in subsets of gliomas, including those with IDH, NF1, or histone (H3 K27M or G34) mutations. Here, we identified ATRX frameshift mutations by next generation sequencing associated with corresponding protein loss in 2 cases of pineal parenchymal tumors of intermediate differentiation (PPTID) developing in a 21-year-old woman and a 64-year-old man. In contrast, we identified partial ATRX loss in 1 pineoblastoma, among 14 pineal parenchymal tumors of various grades (6 pineoblastomas, 4 pineocytomas, and 4 PPTID) using tissue microarrays; ALT was absent in these cases. Evaluating the cBioPortal database, an ATRX mutation was identified in one (of 3 total) PPTIDs analyzed. Thus, ATRX mutations associated with protein loss and ALT develop in a small subset of pineal parenchymal tumors and may be limited to those with intermediate differentiation. The clinical significance of these alterations requires further study.
ABSTRACT
The poly(gallic acid), produced by laccase-mediated oxidation of gallic acid in aqueous media (pH5.5) to attain a novel material with well-defined molecular structure and high water solubility (500mg/mL at 25°C), has been investigated to understand its potential biological activities. In this regard, a biomedical approach based on cytoprotective effect on human fibroblast cells exposed to UV-irradiation in the presence of the polymer has been demonstrated. The results also shows that 200µg/mL of poly(gallic acid) inhibits the growth and migration of dermal fibroblasts and cancer cell lines without affecting cell viability. Poly(gallic acid) pretreatment with 10µg/mL protects dermal fibroblasts from UV induced cell death and additionally, the cytoprotective effect reduce ROS presence in the cells. This property can be correlated with the antioxidant power (IC50 of 23.5µg/mL) of this novel material, which was ascertained by electronic paramagnetic resonance spectroscopy and spectrophotometrically. Additionally, the antimicrobial activity of this material was corroborated with the inhibition of Staphylococcus aureus (ATCC 25923) and Enterococcus faecalis (ATCC 29212) strains (MIC=400mg/mL) common bacteria found in hospitals.
Subject(s)
Fibroblasts , Antioxidants , Gallic Acid , Humans , Staphylococcus aureus , Ultraviolet RaysABSTRACT
OBJECTIVE: Malnutrition has been associated with oxidative damage by altered antioxidant protection mechanisms. Specifically, the aim of this study was to evaluate oxidative damage (DNA and lipid) and antioxidant status (superoxide dismutase [SOD], glutathione peroxidase [GPx], and catalase [CAT] mRNA, and protein expression) in thymus from malnourished rat pups. METHODS: Malnutrition was induced during the lactation period by the food competition method. Oxidative DNA damage was determined quantifying 8-oxo-7, 8-dihydro-2'-deoxyguanosine adduct by high-performance liquid chromatography. Lipid peroxidation was assessed by the formation of thiobarbituric acid-reactive substances. Levels of gene and protein expression of SOD, GPx, and CAT were evaluated by real-time polymerase chain reaction and Western blot, respectively. Antioxidant enzyme activities were measured spectrophotometrically. RESULTS: Oxidative DNA damage and lipid peroxidation significantly increased in second-degree (MN-2) and third-degree malnourished (MN-3) rats compared with well-nourished rats. Higher amounts of oxidative damage, lower mRNA expression, and lower relative concentrations of protein, as well as decreased antioxidant activity of SOD, GPx, and CAT were associated with the MN-2 and MN-3 groups. CONCLUSIONS: The results of this study demonstrated that higher body-weight deficits were related to alterations in antioxidant protection, which contribute to increased levels of damage in the thymus. To our knowledge, this study demonstrated for the first time that early in life, malnutrition leads to increased DNA and lipid oxidative damage, attributable to damaged antioxidant mechanisms including transcriptional and enzymatic activity alterations. These findings may contribute to the elucidation of the causes of previously reported thymus dysfunction, and might explain partially why children and adults who have overcome child undernourishment experience immunologic deficiencies.
Subject(s)
Antioxidants/metabolism , Lactation , Malnutrition/metabolism , Nutritional Status , Oxidative Stress , Oxidoreductases/metabolism , Thymus Gland/metabolism , Animals , Body Weight , Catalase/metabolism , DNA Damage , Female , Glutathione Peroxidase/metabolism , Lipid Peroxidation , Oxidation-Reduction , RNA, Messenger/metabolism , Rats, Wistar , Superoxide Dismutase/metabolism , Thiobarbituric Acid Reactive Substances/metabolismABSTRACT
Human adipose-derived mesenchymal stem cells (hADMSCs) are believed to be potential key factors for starting the regenerative process after tissue injury. However, an efficient method of delivering these regenerative cells to an external wound site is still lacking. Human amnion and pig skin have long been used as skin wound dressings for the treatment of burns and other skin lesions. Herein, we present the generation of two constructs using these two biomaterials as effective scaffolds for the culture of hADMSCs. It was found that hADMSCs seeded onto radiosterilized human amnion and pig skin are viable and proliferate. These cells are able to migrate over these scaffolds as demonstrated by using time-lapse microscopy. In addition, the scaffolds induce hADMSCs to secrete interleukin-10, an important negative regulator of inflammation, and interleukin-1ß, a proinflammatory protein. The interplay between these two proteins has been proven to be vital for a balanced restoration of all necessary tissues. Thus, radiosterilized human amnion and pig skin are likely suitable scaffolds for delivery of hADMSCs transplants that could promote tissue regeneration in skin injuries like patients with burn injuries.
Subject(s)
Amnion/physiology , Bandages , Mesenchymal Stem Cell Transplantation/methods , Mesenchymal Stem Cells/cytology , Skin/metabolism , Wound Healing/physiology , Adipose Tissue/cytology , Animals , Biocompatible Materials , Cell Culture Techniques , Cells, Cultured , Humans , Interleukin-10/biosynthesis , Interleukin-1beta/biosynthesis , Swine , Tissue Scaffolds , Wounds and Injuries/therapyABSTRACT
We applied the so-called chemical kinetics approach to complex bacterial growth patterns that were dependent on the liquid-surface-area-to-volume ratio (SA/V) of the bacterial cultures. The kinetic modeling was based on current experimental knowledge in terms of autocatalytic bacterial growth, its inhibition by the metabolite CO2, and the relief of inhibition through the physical escape of the inhibitor. The model quantitatively reproduces kinetic data of SA/V-dependent bacterial growth and can discriminate between differences in the growth dynamics of enteropathogenic E. coli, E. coli JM83, and Salmonella typhimurium on one hand and Vibrio cholerae on the other hand. Furthermore, the data fitting procedures allowed predictions about the velocities of the involved key processes and the potential behavior in an open-flow bacterial chemostat, revealing an oscillatory approach to the stationary states.
Subject(s)
Escherichia coli/growth & development , Salmonella typhimurium/growth & development , Vibrio cholerae/growth & development , Vibrio cholerae/radiation effects , Carbon Monoxide/pharmacology , Escherichia coli/radiation effects , Kinetics , Salmonella typhimurium/radiation effectsABSTRACT
Vibrio cholerae O1 classical, El Tor and O139 are the primary biotypes that cause epidemic cholera, and they also express cholera toxin (CT). Although classical V. cholerae produces CT in various settings, the El Tor and O139 strains require specific growth conditions for CT induction, such as the so-called AKI conditions, which consist of growth in static conditions followed by growth under aerobic shaking conditions. However, our group has demonstrated that CT production may also take place in shallow static cultures. How these type of cultures induce CT production has been unclear, but we now report that in shallow culture growth conditions, there is virtual depletion of dissolved oxygen after 2.5 h of growth. Concurrently, during the first three to 4 h, endogenous CO2 accumulates in the media and the pH decreases. These findings may explain CT expression at the molecular level because CT production relies on a regulatory cascade, in which the key regulator AphB may be activated by anaerobiosis and by low pH. AphB activation stimulates TcpP synthesis, which induces ToxT production, and ToxT directly stimulates ctxAB expression, which encodes CT. Importantly, ToxT activity is enhanced by bicarbonate. Therefore, we suggest that in shallow cultures, AphB is activated by initial decreases in oxygen and pH, and subsequently, ToxT is activated by intracellular bicarbonate that has been generated from endogenous CO2. This working model would explain CT production in shallow cultures and, possibly, also in other growth conditions.
Subject(s)
Bacterial Proteins/metabolism , Cholera Toxin/metabolism , Gene Expression Regulation, Bacterial , Vibrio cholerae/metabolism , Bacterial Proteins/genetics , Carbon Dioxide/chemistry , Cholera Toxin/genetics , Culture Media/chemistry , Hydrogen-Ion Concentration , Oxygen/chemistry , Vibrio cholerae/geneticsABSTRACT
Malnutrition is a common cause of secondary immune deficiency and has been linked to an increased susceptibility to infection in humans. Malnutrition specifically affects T-cell-mediated immune responses. The aim of this study was to assess in lymphocytes from malnourished children the expression levels of IL-12, IL-18 and IL-21, molecules that induce the differentiation of T cells related to the immunological cellular response (Th1 response) and the production of cytokines related to the immunological cellular response (Th1 cytokines). We found that the expression levels of IL-12, IL-18 and IL-21 were significantly diminished in malnourished children compared to well-nourished children and were coincident with lower plasmatic levels of IL-2 and IFN-γ (Th1 cytokines). In this study, we show for the first time that the gene expression and intracellular production of cytokines responsible for Th1 cell differentiation (IL-12, IL-18 and IL-21) are diminished in malnourished children. As expected, this finding was related to lower plasmatic levels of IL-2 and IFN-γ. The decreased expression of Th1 cytokines observed in this study may contribute to the deterioration of the immunological Type 1 (cellular) response. We hypothesize that the decreased production of IL-12, IL-18 and IL-21 in malnourished children contributes to their inability to eradicate infections.
Subject(s)
Cell Differentiation/immunology , Cytokines/genetics , Gene Expression , Malnutrition/immunology , Th1 Cells/immunology , Bacterial Infections/complications , Bacterial Infections/immunology , Female , Gastrointestinal Diseases/complications , Gastrointestinal Diseases/immunology , Gastrointestinal Diseases/microbiology , Humans , Infant , Interferon-gamma/blood , Interleukin-12/genetics , Interleukin-12/immunology , Interleukin-18/genetics , Interleukin-18/immunology , Interleukin-2/blood , Interleukins/genetics , Interleukins/immunology , Male , Malnutrition/complications , Respiratory Tract Infections/complications , Respiratory Tract Infections/immunologyABSTRACT
We assessed the role of plasminogen activator inhibitor-1 (PAI-1) and matrix metalloproteinase 9 (MMP9) in wound healing process and in the bone marrow mononuclear cells (BMMNC)-related effects on physiological and pathological wound healing. A full thickness excision wound was created by removal of the skin on the midback of irradiated and nonirradiated animals. Angiogenesis and re-epithelialization were markedly increased in PAI-1-/- mice compared to wild-type (WT) animals. We revealed high MMP activity in tissue of PAI-1-/- animals. Of interest, the wound healing process was reduced in PAI-1-/-:MMP9-/- animals compared to PAI-1-/- mice, suggesting a key role of MMP9 in beneficial effect of PAI-1 deficiency on wound closure. To unravel the role of PAI-1 in BMMNC relative effects, mice were treated with or without local injection of BMMNC isolated from WT, PAI-1-/-, and PAI-1-/-: MMP9-/- animals for 14 days (10(6) cells, n = 6 per group). In WT nonirradiated mice, transplantation of BMMNC isolated from PAI-1-/- animals enhanced wound formation when compared with WT BMMNC. BMMNC differentiation into cells with endothelial phenotype was enhanced by PAI-1 deficiency. These effects were abrogated in PAI-1-/-:MMP9-/- and MMP9-/- BMMNC. In addition, using chimeric mice, we demonstrated that PAI-1 deficiency environment increased the BMMNC-GFP recruitment to the wound site, whereas this effect was abrogated when using PAI-1-/-:MMP9-/- BMMNC. PAI-1 deficiency, at least through MMP9 upregulation, enhanced wound healing and BMMNC therapeutic potential in irradiated and nonirradiated animals.
Subject(s)
Bone Marrow Cells/cytology , Bone Marrow Cells/metabolism , Matrix Metalloproteinase 9/metabolism , Plasminogen Activator Inhibitor 1/metabolism , Wound Healing/physiology , Animals , Cell Differentiation/genetics , Cell Differentiation/physiology , Male , Matrix Metalloproteinase 9/genetics , Mice , Mice, Knockout , Plasminogen Activator Inhibitor 1/genetics , Wound Healing/genetics , Wound Healing/radiation effectsABSTRACT
The growth dynamics of bacterial populations are usually represented by the classical S-shaped profiles composed of lag, exponential and stationary growth phases. Although exceptions to this classical behavior occur, they are normally produced under non-standard conditions such as supply of two carbohydrates as sole carbon source. However, we here report variations in the classic S-shaped growth profiles of Escherichia coli under standard culturing conditions; explicitly, we found growth during transition to the stationary phase wherein the bacterial growth rate inversely depended on the volume-to-surface ratio of cultures (V/S); the reasons for this behavior were experimentally explored. To complement our experimental analysis, a theoretical model that rationalizes the bacterial response was developed; simulations based on the developed model essentially reproduced experimental growth curves. We consequently conclude that the effect of V/S on E. coli growth reflects an interplay between auto-catalytic bacterial growth, bacterial growth auto-inhibition, and, the relief of that inhibition.
Subject(s)
Escherichia coli/growth & development , Escherichia coli/chemistry , Kinetics , Models, TheoreticalABSTRACT
Analysis of the growth kinetics of enteropathogenic Escherichia coli (EPEC) revealed that growth was directly proportional to the ratio between the exposed surface area and the liquid culture volume (SA/V). It was hypothesized that this bacterial behavior was caused by the accumulation of an endogenous volatile growth inhibitor metabolite whose escape from the medium directly depended on the SA/V. The results of this work support the theory that an inhibitor is produced and indicate that it is CO(2). We also report that concomitant to the accumulation of CO(2), there is secretion of the virulence-related EspB and EspC proteins from EPEC. We therefore postulate that endogenous CO(2) may have an effect on both bacterial growth and virulence.
Subject(s)
Carbon Dioxide/metabolism , Enteropathogenic Escherichia coli/growth & development , Enteropathogenic Escherichia coli/metabolism , Gene Expression Regulation, Bacterial , Virulence Factors/metabolism , Bacterial Outer Membrane Proteins/metabolism , Culture Media/chemistry , Escherichia coli Proteins/metabolismABSTRACT
INTRODUCTION: Protein-calorie malnutrition represents a significant worldwide health problem and is associated with an increased risk for infections. The purpose of this study was to evaluate possible changes in type 1/type 2 responses balance in malnourished children. RESULTS: The data obtained in the present study showed that the expression levels of tumor necrosis factor-alpha, interleukin (IL)-4, and IL-10 were more highly, in contrast IL-2, gamma interferon, and IL-6 genes were expressed less in all groups of malnourished children compared with the well-nourished infected children. It is important to indicate that the data collected in the present work agree with the results obtained by different authors, who showed differences in the production of cytokines in malnourished children. CONCLUSION: In conclusion, the results suggest that alterations in the balance of type 1/type 2 immune responses exist in malnourished children, and this could be the reason that the immunological system of the malnourished children is incapable of eradicating infections.
Subject(s)
Child Nutrition Disorders/genetics , Cytokines/genetics , Infant Nutrition Disorders/genetics , Th1 Cells/metabolism , Th2 Cells/metabolism , Child Nutrition Disorders/blood , Child Nutrition Disorders/immunology , Child, Preschool , Cohort Studies , Cytokines/biosynthesis , Cytokines/blood , Female , Humans , Infant , Infant Nutrition Disorders/blood , Infant Nutrition Disorders/immunology , Male , RNA, Messenger/analysis , RNA, Messenger/blood , Risk Factors , Severity of Illness Index , Th1 Cells/immunology , Th2 Cells/immunologyABSTRACT
Este es un trabajo teórico donde se ofrecen algunos elementos generales sobre la comunicación, se caracterizan la empatía y la capacidad de resonancia. El objetivo de éste es brindar herramientas comunicativas a los profesionales de la salud. Se aplican los conocimientos de la Inteligencia Emocional a la comunicación con personas sanas, personas enfermas y sus familiares, y se brindan algunos principios y recursos comunicativos para los profesionales de nuestro sector en el ejercicio de hacer más humanos nuestros servicios.
This is a theoretical paper report which offers some general knowledge about face-to-face communication. The purpose is to give some tools for health professional communication. The author characterizes empathy and resonance skills. Ideas of Emotional Intelligence are considered in relation to communication with healthy and sick people and their relatives. Some principles and communication resources are proposed to the health professionals so that they can render more humanitarian health services.
ABSTRACT
Este es un trabajo teórico donde se ofrecen algunos elementos generales sobre la comunicación, se caracterizan la empatía y la capacidad de resonancia. El objetivo de éste es brindar herramientas comunicativas a los profesionales de la salud. Se aplican los conocimientos de la Inteligencia Emocional a la comunicación con personas sanas, personas enfermas y sus familiares, y se brindan algunos principios y recursos comunicativos para los profesionales de nuestro sector en el ejercicio de hacer más humanos nuestros servicios(AU)
This is a theoretical paper report which offers some general knowledge about face-to-face communication. The purpose is to give some tools for health professional communication. The author characterizes empathy and resonance skills. Ideas of Emotional Intelligence are considered in relation to communication with healthy and sick people and their relatives. Some principles and communication resources are proposed to the health professionals so that they can render more humanitarian health services(AU)
Subject(s)
Communication , Empathy , Attitude of Health Personnel , Health Education , HumanismABSTRACT
En la Sesión Plenaria Final, en la que se dió lectura a los Relatos de cada uno de los Simposios, dando así oportunidad a que todos los participantes en el Taller pudieran opinar sobre los distintos temas, incluidos aquellos tratados en los Simposios donde no habían participado, se enfatizó en los siguientes aspectos: --Es necesaria la actualización y formación en Ética de todos los trabajadores de la salud. --El ejemplo constituye la base fundamental de la educación ética. --La educación ética y bioética se fortalece en la educación en el trabajo. --Se deben combinar la teoría y la práctica. --Aprovechar todas las posibilidades de la Extensión Universitaria , como los talleres de reflexión y debate, para la formación ética. --Realizar las acciones de educación con la comunidad. Se puso en evidencia el consenso acerca de los pronunciamientos realizados en todos los Simposios, especialmente todo lo tratado en el Simposio de los Entrenamientos a los Comités de Etica de Investigación. Igualmente en la Plenaria se evidenció la falta de consenso en relación con la forma de inclusión de la Etica y la Bioética en el pre-grado. Unos plantearon que debía ser como estrategia curricular y otros sostienen el criterio de que, además, es necesaria una asignatura curricular, como ya existe en las carreras de Enfermería y Tecnología de la Salud
Subject(s)
Congresses as Topic/ethics , Bioethics/education , Bioethical IssuesABSTRACT
Estudio de 15 mujeres con el fin de caracterizar el estrés que experimentan las cuidadoras de un familiar dependiente. Éste utiliza una metodología de investigación cualitativa, fundamentada en el estudio de casos múltiples(AU)