An Empirical-Mathematical Approach for Calibration and Fitting Cell-Electrode Electrical Models in Bioimpedance Tests.

This paper proposes a new yet efficient method allowing a significant improvement in the on-line analysis of biological cell growing and evolution. The procedure is based on an empirical-mathematical approach for calibration and fitting of any cell-electrode electrical model. It is valid and can be extrapolated for any type of cellular line used in electrical cell-substrate impedance spectroscopy (ECIS) tests. Parameters of the bioimpedance model, acquired from ECIS experiments, vary for each cell line, which makes obtaining results difficult and-to some extent-renders them inaccurate. We propose a fitting method based on the cell line initial characterization, and carry out subsequent experiments with the same line to approach the percentage of well filling and the cell density (or cell number in the well). To perform our calibration technique, the so-called oscillation-based test (OBT) approach is employed for each cell density. Calibration results are validated by performing other experiments with different concentrations on the same cell line with the same measurement technique. Accordingly, a bioimpedance electrical model of each cell line is determined, which is valid for any further experiment and leading to a more precise electrical model of the electrode-cell system. Furthermore, the model parameters calculated can be also used by any other measurement techniques. Promising experimental outcomes for three different cell-lines have been achieved, supporting the usefulness of this technique.

Remote Cell Growth Sensing Using Self-Sustained Bio-Oscillations.

A smart sensor system for cell culture real-time supervision is proposed, allowing for a significant reduction in human effort applied to this type of assay. The approach converts the cell culture under test into a suitable "biological" oscillator. The system enables the remote acquisition and management of the "biological" oscillation signals through a secure web interface. The indirectly observed biological properties are cell growth and cell number, which are straightforwardly related to the measured bio-oscillation signal parameters, i.e., frequency and amplitude. The sensor extracts the information without complex circuitry for acquisition and measurement, taking advantage of the microcontroller features. A discrete prototype for sensing and remote monitoring is presented along with the experimental results obtained from the performed measurements, achieving the expected performance and outcomes.

[A score to predict medical emergencies in hospitalized patients]. / Puntaje predictivo de emergencias médicas en un servicio médico quirúrgico, usando variables clínicas y los diagnósticos de ingreso.

BACKGROUND: The medical alert system (MAS) was created for the timely handling of clinical decompensations, experienced by patients hospitalized at the Medical Surgical Service (MSS) in a private clinic. It is activated by the nurse when hemodynamic, respiratory, neurological, infectious or metabolic alterations appear, when a patient falls or complains of pain. A physician assesses the patient and decides further therapy. AIM: To analyze the clinical and demographic characteristics of patients who activated or not the MAS and develop a score to identify patients who will potentially activate MAS. MATERIAL AND METHODS: Data from 13,933 patients discharged from the clinic in a period of one year was analyzed. RESULTS: MAS was activated by 472 patients (3.4%). Twenty two of these patients died during hospital stay compared to 68 patients who did not activate the alert (0.5%, p < 0.01). The predictive score developed considered age, diagnosis (based on the tenth international classification of diseases) and whether the patient was medical or surgical. The score ranges from 0 to 9 and a cutoff ≥ 6 provides a sensitivity and specificity of 37 and 81% respectively and a positive likelihood ratio (LR+) of 1.9 to predict the activation of MAS. The same cutoff value predicts death with a sensitivity and specificity of 80% and a negative predictive value of 99.8%. CONCLUSIONS: This score may be useful to identify hospitalized patients who may have complications during their hospital stay.

Electrical pulse stimulation parameters modulate N2a neuronal differentiation.

Electrical pulse stimulation has been used to enhance the differentiation or proliferation of neuronal progenitor cells in tissue engineering and cancer treatment. Therefore, a comprehensive investigation of the effects caused by its parameters is crucial for improvements in those fields. We propose a study of pulse parameters, to allow the control of N2a cell line fate and behavior. We have focused on designing an experimental setup that allows for the knowledge and control over the environment and the stimulation signals applied. To map the effects of the stimulation on N2a cells, their morphology and the cellular and molecular reactions induced by the pulse stimulation have been analyzed. Immunofluorescence, rt-PCR and western blot analysis have been carried out for this purpose, as well as cell counting. Our results show that low-amplitude electrical pulse stimulation promotes proliferation of N2a cells, whilst amplitudes in the range 250 mV/mm-500 mV/mm induce differentiation. Amplitudes higher than 750 mV/mm produce cell damage at low frequencies. For high frequencies, large amplitudes are needed to cause cell death. An inverse relation has been found between cell density and pulse-induced neuronal differentiation. The best condition for neuronal differentiation was found to be 500 mV/mm at 100 Hz. These findings have been confirmed by up-regulation of the Neurod1 gene. Our preliminary study of the molecular effects of electrical pulse stimulation on N2a offers premonitory clues of the PI3K/Akt/GSK-3ß pathway implications on the neuronal differentiation process through ES. In general, we have successfully mapped the sensitivity of N2a cells to electrical pulse stimulation parameters.

[Strategies and recommendations to face respiratory syncytial virus disease in 2024]. / Estrategias y recomendaciones para enfrentar la enfermedad por virus respiratorio sincicial el año 2024.

During the winter of 2023, Chile faced a complex situation related to the respiratory syncytial virus (RSV). After experiencing a decline in RSV circulation during the years of the SARS-CoV-2 pandemic, a late outbreak was observed in the spring of 2022 and an early onset of the outbreak in 2023, with a significant increase in the number of serious cases. The ineffectiveness of strategic planning and risk communication contributed to the complexity of the situation. To avoid the above next winter, measures such as active surveillance, unification of definitions for acute respiratory infections, identification of RSV variants, public education about infections and advance preparation regarding hospital beds and health personnel are suggested. The importance of immunization and intersectoral collaboration to acquire new preventive alternatives is highlighted, as well as the need for early communication about the importance of immunization and identification of high-risk groups, improvement in training of medical personnel and strategic planning of the Ministry of Health. seeking a proactive and collaborative approach to address the complex RSV situation in future winters. The Chilean Immunization Advisory Committee has already carried out an analysis and recommendation on a new prevention alternative. This working group will support any decision of the Ministry of Health in public policies that attempt a change in the paradigm of control of this disease for the health of the children of our country.

Predictive Cell Culture Time Evolution Based on Electric Models.

Obtaining cell concentration measurements from a culture assay by using bioimpedance is a very useful method that can be used to translate impedances to cell concentration values. The purpose of this study was to find a method to obtain the cell concentration values of a given cell culture assay in real time by using an oscillator as the measurement circuit. From a basic cell-electrode model, enhanced models of a cell culture immersed in a saline solution (culture medium) were derived. These models were used as part of a fitting routine to estimate the cell concentration in a cell culture in real time by using the oscillation frequency and amplitude delivered by the measurement circuits proposed by previous authors. Using real experimental data (the frequency and amplitude of oscillations) that were obtained by connecting the cell culture to an oscillator as the load, the fitting routine was simulated, and real-time data of the cell concentration were obtained. These results were compared to concentration data that were obtained by using traditional optical methods for counting. In addition, the error that we obtained was divided and analyzed in two parts: the first part of the experiment (when the few cells were adapting to the culture medium) and the second part of the experiment (when the cells exponentially grew until they completely covered the well). Low error values were obtained during the growth phase of the cell culture (the relevant phase); therefore, the results obtained were considered promising and show that the fitting routine is valid and that the cell concentration can be measured in real time by using an oscillator.

DC electrical stimulation enhances proliferation and differentiation on N2a and MC3T3 cell lines.

BACKGROUND: Electrical stimulation is a novel tool to promote the differentiation and proliferation of precursor cells. In this work we have studied the effects of direct current (DC) electrical stimulation on neuroblastoma (N2a) and osteoblast (MC3T3) cell lines as a model for nervous and bone tissue regeneration, respectively. We have developed the electronics and encapsulation of a proposed stimulation system and designed a setup and protocol to stimulate cell cultures. METHODS: Cell cultures were subjected to several assays to assess the effects of electrical stimulation on them. N2a cells were analyzed using microscope images and an inmunofluorescence assay, differentiated cells were counted and neurites were measured. MC3T3 cells were subjected to an AlamarBlue assay for viability, ALP activity was measured, and a real time PCR was carried out. RESULTS: Our results show that electrically stimulated cells had more tendency to differentiate in both cell lines when compared to non-stimulated cultures, paired with a promotion of neurite growth and polarization in N2a cells and an increase in proliferation in MC3T3 cell line. CONCLUSIONS: These results prove the effectiveness of electrical stimulation as a tool for tissue engineering and regenerative medicine, both for neural and bone injuries. Bone progenitor cells submitted to electrical stimulation have a higher tendency to differentiate and proliferate, filling the gaps present in injuries. On the other hand, neuronal progenitor cells differentiate, and their neurites can be polarized to follow the electric field applied.

Autophagic receptor p62 protects against glycation-derived toxicity and enhances viability.

Diabetes and metabolic syndrome are associated with the typical American high glycemia diet and result in accumulation of high levels of advanced glycation end products (AGEs), particularly upon aging. AGEs form when sugars or their metabolites react with proteins. Associated with a myriad of age-related diseases, AGEs accumulate in many tissues and are cytotoxic. To date, efforts to limit glycation pharmacologically have failed in human trials. Thus, it is crucial to identify systems that remove AGEs, but such research is scanty. Here, we determined if and how AGEs might be cleared by autophagy. Our in vivo mouse and C. elegans models, in which we altered proteolysis or glycative burden, as well as experiments in five types of cells, revealed more than six criteria indicating that p62-dependent autophagy is a conserved pathway that plays a critical role in the removal of AGEs. Activation of autophagic removal of AGEs requires p62, and blocking this pathway results in accumulation of AGEs and compromised viability. Deficiency of p62 accelerates accumulation of AGEs in soluble and insoluble fractions. p62 itself is subject to glycative inactivation and accumulates as high mass species. Accumulation of p62 in retinal pigment epithelium is reversed by switching to a lower glycemia diet. Since diminution of glycative damage is associated with reduced risk for age-related diseases, including age-related macular degeneration, cardiovascular disease, diabetes, Alzheimer's, and Parkinson's, discovery of methods to limit AGEs or enhance p62-dependent autophagy offers novel potential therapeutic targets to treat AGEs-related pathologies.

Genotoxicity detected in wild mice living in a highly polluted wetland area in south western Spain.

A field study was carried out in the south of the Iberian Peninsula in an industrial area in the neighbourhood of Huelva city, SW Spain, and in a natural area (Doñana National Park) for comparison, to estimate the genetic risk induced by environmental pollution in wild mice. Genotoxic effects in a sentinel organism, the Algerian mice (Mus spretus) free living in the industrial area were compared with animals of the same species living in the natural protected area. The single cell gel electrophoresis, or Comet assay, was performed as a genotoxicity test in peripheral blood of mice. Our results clearly show that mice free living in the contaminated area bear a high burden of genetic damage as compared with control individuals. The results suggest that the assessing of genotoxicity levels by the Comet assay in wild mice can be used as a valuable test in pollution monitoring and environmental conservation.

Sensing Cell-Culture Assays with Low-Cost Circuitry.

An alternative approach for cell-culture end-point protocols is proposed herein. This new technique is suitable for real-time remote sensing. It is based on Electrical Cell-substrate Impedance Spectroscopy (ECIS) and employs the Oscillation-Based Test (OBT) method. Simple and straightforward circuit blocks form the basis of the proposed measurement system. Oscillation parameters - frequency and amplitude - constitute the outcome, directly correlated with the culture status. A user can remotely track the evolution of cell cultures in real time over the complete experiment through a web tool continuously displaying the acquired data. Experiments carried out with commercial electrodes and a well-established cell line (AA8) are described, obtaining the cell number in real time from growth assays. The electrodes have been electrically characterized along the design flow in order to predict the system performance and the sensitivity curves. Curves for 1-week cell growth are reported. The obtained experimental results validate the proposed OBT for cell-culture characterization. Furthermore, the proposed electrode model provides a good approximation for the cell number and the time evolution of the studied cultures.

Antifungal activity of strawberry fruit volatile compounds against Colletotrichum acutatum.

Eight volatile products characterizing strawberry aroma, which is generated from the oxidative degradation of linoleic and linolenic acids by a lipoxygenase (LOX) pathway, were examined because of their antifungal activity against Colletotrichum acutatum, one of the causal agents of strawberry anthracnose. In this study, the effects of aldehydes, alcohols, and esters on mycelial growth and conidia development were evaluated. (E)-Hex-2-enal was found to be the best inhibitor of mycelial growth [MID (minimum inhibitory doses)=33.65 microL L(-1)] and of spore germination (MID=6.76 microL L(-1)), while hexyl acetate was the least effective of all volatile compounds tested (MID=6441.89 microL L(-1) for mycelial growth and MID=1351.35 microL L(-1) for spore germination). Furthermore, the antifungal activity of (E)-hex-2-enal on susceptibility of strawberry fruits to C. acutatum was also confirmed. The presence of these molecules in jars containing strawberry fruits inoculated with a suspension of spores inhibited the fungus growth and prevented the appearance of symptoms. Moreover, a study of the effects of (E)-hex-2-enal on conidial cells of C. acutatum was evaluated by transmission electron microscopy. This volatile compound altered the structures of the cell wall and plasma membrane, causing disorganization and lysis of organelles and, eventually, cell death.

Comunicación entre paciente adulto críticamente enfermo y el profesional de enfermería: una revisión integrativa / Comunicação entre paciente adulto crítico e enfermeiro: uma revisão integrativa / Communication between the user critically ill adult and the nursing professional: an integrative review

Resumen: Introducción: La comunicación entre enfermero y paciente que se encuentra en unidades críticas con compromiso vital está limitada por la sedación, ventilación mecánica, y presencia de tubo endotraqueal, interfiriendo en la entrega de cuidados. Objetivo: analizar en la literatura científica publicada cómo se efectúa la comunicación entre el paciente adulto críticamente enfermo y profesionales de enfermería. Metodología: Revisión integrativa de diversas bases de datos. En el análisis crítico, 13 artículos cumplieron los criterios de inclusión. Como criterio de exclusión se consideraron los artículos desarrollados en usuarios pediátricos y otros servicios de hospitalización. Resultados: de la revisión surgieron tres temáticas, a) Métodos de comunicación paciente crítico-enfermero b) Percepción del paciente sobre la comunicación enfermero-paciente c) Factores limitantes en la comunicación enfermero- paciente crítico. Conclusiones: Se concluye que las actividades asistenciales de enfermería en estas unidades se centran casi en su totalidad en acciones biomédicas, relegando a un segundo plano aspectos emocionales. Existe una necesidad de desarrollar habilidades de comunicación para garantizar que todo enfermero que trabaja con pacientes críticamente enfermos, sean capaces de generar una comunicación efectiva con el paciente y su entorno, actuando como agentes de cambio para fortalecer el cuidado de manera holística y humanizada.

Resumo: Introdução: A comunicação entre enfermeira e usuário que se encontra em unidades críticas é de vital importância, entretanto, está limitada pela sedação, ventilação mecânica e presença de tubo endotraqueal, interferindo no processo de trabalho. Objetivo: analisar na literatura científica publicada como é realizada a comunicação entre o paciente adulto crítico e os profissionais de enfermagem. Material e Métodos: Realizou-se uma revisão integrativa em distintas bases de dados, em que foram encontrados 13 artigos que cumpriram com os critérios de inclusão. Foram excluídos artigos desenvolvidos em unidades da pediatria e outros serviços de hospitalização. Resultados: A revisão sugeriu três temáticas, (a) Métodos de comunicação entre usuário crítico-enfermeira, (b) Percepção do usuário sobre a comunicação da enfermeira-usuário, (c) Fatores limitantes na comunicação enfermeira-usuário crítico. Conclusões: As atividades assistenciais da enfermagem nessas unidades se encontram na sua totalidade em ações clínicas, deixando em segundo plano os aspectos emocionais. Existe uma necessidade de desenvolver habilidades de comunicação para garantir que toda enfermeira que trabalha com usuários criticamente doentes, sejam capazes de gerar uma comunicação efetiva com o usuário e seu ambiente, atuando como agentes de troca para fortalecer o cuidado holístico e humanizado.

Abstract: Introduction: The communication between nurse and user that is in critical units with vital commitment is limited by sedation, mechanical ventilation, and presence of endotracheal tube, interfering in the delivery of care. Aim: analyze in the published scientific literature how communication is carried out between nursing professionals and the critically ill adult patient. Methodology: Integrative review in various databases were made, 13 articles fulfill the inclusion criteria and were analyzed. As exclusive criteria articles developed in pediatric users and other hospitalization services were considered. Results: From the selected articles arose three topics: (a) Methods of communication critical user-nurse, (b) User's perception of the communication nurse- user, (c) Limiting factors in the communication nurse-critical user. Conclusions: The assistance activities of the nursing in the units of critical care are centered almost entirely in the actions derived from the diagnostic and medical treatment, relegating the emotional aspects to the background. It exists a need of training in communication abilities to guarantee that every nurse working with users critically ill is able to establish an effective communication with the patient and his environment, because the nurses should be agents to potentiate changes and generate humanized care.

Age-related dysfunctions of the autophagy lysosomal pathway in hippocampal pyramidal neurons under proteasome stress.

Autophagy plays a key role in the maintenance of cellular homeostasis, and autophagy deregulation gives rise to severe disorders. Many of the signaling pathways regulating autophagy under stress conditions are still poorly understood. Using a model of proteasome stress in rat hippocampus, we have characterized the functional crosstalk between the ubiquitin proteasome system and the autophagy-lysosome pathway, identifying also age-related modifications in the crosstalk between both proteolytic systems. Under proteasome inhibition, both autophagy activation and resolution were efficiently induced in young but not in aged rats, leading to restoration of protein homeostasis only in young pyramidal neurons. Importantly, proteasome stress inhibited glycogen synthase kinase-3ß in young but activated in aged rats. This age-related difference could be because of a dysfunction in the signaling pathway of the insulin growth factor-1 under stress situations. Present data highlight the potential role of glycogen synthase kinase-3ß in the coordination of both proteolytic systems under stress situation, representing a key molecular target to sort out this deleterious effect.

Breast cancer cell line MCF7 escapes from G1/S arrest induced by proteasome inhibition through a GSK-3ß dependent mechanism.

Targeting the ubiquitin proteasome pathway has emerged as a rational approach in the treatment of human cancers. Autophagy has been described as a cytoprotective mechanism to increase tumor cell survival under stress conditions. Here, we have focused on the role of proteasome inhibition in cell cycle progression and the role of autophagy in the proliferation recovery. The study was performed in the breast cancer cell line MCF7 compared to the normal mammary cell line MCF10A. We found that the proteasome inhibitor MG132 induced G1/S arrest in MCF10A, but G2/M arrest in MCF7 cells. The effect of MG132 on MCF7 was reproduced on MCF10A cells in the presence of the glycogen synthase kinase 3ß (GSK-3ß) inhibitor VII. Similarly, MCF7 cells overexpressing constitutively active GSK-3ß behaved like MCF10A cells. On the other hand, MCF10A cells remained arrested after MG132 removal while MCF7 recovered the proliferative capacity. Importantly, this recovery was abolished in the presence of the autophagy inhibitor 3-methyladenine (3-MA). Thus, our results support the relevance of GSK-3ß and autophagy as two targets for controlling cell cycle progression and proliferative capacity in MCF7, highlighting the co-treatment of breast cancer cells with 3-MA to synergize the effect of the proteasome inhibition.

Puntaje predictivo de emergencias médicas en un servicio médico quirúrgico, usando variables clínicas y los diagnósticos de ingreso / A score to predict medical emergencies in hospitalized patients

Background: The medical alert system (MAS) was created for the timely handling of clinical decompensations, experienced by patients hospitalized at the Medical Surgical Service (MSS) in a private clinic. It is activated by the nurse when hemodynamic, respiratory, neurological, infectious or metabolic alterations appear, when a patient falls or complains of pain. A physician assesses the patient and decides further therapy. Aim: To analyze the clinical and demographic characteristics of patients who activated or not the MAS and develop a score to identify patients who will potentially activate MAS. Material and Methods: Data from 13,933 patients discharged from the clinic in a period of one year was analyzed. Results: MAS was activated by 472 patients (3.4%). Twenty two of these patients died during hospital stay compared to 68 patients who did not activate the alert (0.5%, p < 0.01). The predictive score developed considered age, diagnosis (based on the tenth international classification of diseases) and whether the patient was medical or surgical. The score ranges from 0 to 9 and a cutoff ≥ 6 provides a sensitivity and specificity of 37 and 81% respectively and a positive likelihood ratio (LR+) of 1.9 to predict the activation of MAS. The same cutoff value predicts death with a sensitivity and specificity of 80% and a negative predictive value of 99.8%. Conclusions: This score may be useful to identify hospitalized patients who may have complications during their hospital stay.

Using microelectrode models for real time cell-culture monitoring.

This paper proposes a cell-microelectrode model for cell biometry applications, based on the area overlap as main parameter. The model can be applied to cell size identification, cell count, and their extension to cell growth and dosimetry protocols. Experiments performed with comercial electrodes are presented, illustrating a procedure to obtain cell number in both growth and dosimetry processes. Results obtained for the AA8 cell line are promising.