Electroencephalography spectral edge frequency and suppression rate-guided sedation in patients with COVID-19: A randomized controlled trial.

Background: Sedation in coronavirus disease 2019 (COVID-19) patients has been identified as a major challenge. We aimed to investigate whether the use of a multiparameter electroencephalogram (EEG) protocol to guide sedation in COVID-19 patients would increase the 30-day mechanical ventilation-free days (VFD). Methods: We conducted a double-blind randomized clinical trial. We included patients with severe pneumonia due to COVID-19 who required mechanical ventilation (MV) and deep sedation. We randomized to the control (n = 25) or multiparameter group (n = 25). Sedation in the intervention group was administered following the standard institutional protocols together with a flow chart designed to reduce the propofol administration dose if the EEG suppression rate was over 2% or the spectral edge frequency 95 (SEF95) was below 10 Hz. We performed an intention-to-treat analysis to evaluate our primary outcome (30-day VFD). Results: There was no difference in VFD at day 30 (median: 11 [IQR 0-20] days in the control group vs. 0 [IQR 0-21] days in the BIS multiparameter group, p = 0.87). Among secondary outcomes, we documented a 17% reduction in the total adjusted propofol administered during the first 5 days of the protocol [median: 2.3 (IQR 1.9-2.8) mg/k/h in the control group vs. 1.9(IQR 1.5-2.2) mg/k/h in the MP group, p = 0.005]. This was accompanied by a higher average BIS value in the intervention group throughout the treatment period. Conclusion: A sedation protocol guided by multivariate EEG-derived parameters did not increase the 30-day VFD. However, the intervention led to a reduction in total propofol administration.

[Update on the management of intracranial hypertension syndrome]. / Actualización en el tratamiento del síndrome de hipertensión intracraneana.

Elevated intracranial pressure (ICP) is a devastating complication, with great impact on neurological status and high morbidity and mortality. Intracranial hypertension (ICH) has multiple etiologies. The natural history of this condition can lead to brain death. The successful management of patients with elevated ICP (> 20-25 mmHg) requires fast and timely recognition, judicious use of invasive monitoring and therapies aimed to reversing its underlying cause. Therefore, it must be managed as a neurological emergency. The objective of this review is to present in a friendly way the diagnostic approach and the management of ICH, focused on general practitioners.

Relationship Between Endothelial and Angiogenesis Biomarkers Envisage Mortality in a Prospective Cohort of COVID-19 Patients Requiring Respiratory Support.

Purpose: Endothelial damage and angiogenesis are fundamental elements of neovascularisation and fibrosis observed in patients with coronavirus disease 2019 (COVID-19). Here, we aimed to evaluate whether early endothelial and angiogenic biomarkers detection predicts mortality and major cardiovascular events in patients with COVID-19 requiring respiratory support. Methods: Changes in serum syndecan-1, thrombomodulin, and angiogenic factor concentrations were analysed during the first 24 h and 10 days after COVID-19 hospitalisation in patients with high-flow nasal oxygen or mechanical ventilation. Also, we performed an exploratory evaluation of the endothelial migration process induced by COVID-19 in the patients' serum using an endothelial cell culture model. Results: In 43 patients, mean syndecan-1 concentration was 40.96 ± 106.9 ng/mL with a 33.9% increase (49.96 ± 58.1 ng/mL) at day 10. Both increases were significant compared to healthy controls (Kruskal-Wallis p < 0.0001). We observed an increase in thrombomodulin, Angiopoietin-2, human vascular endothelial growth factor (VEGF), and human hepatocyte growth factor (HGF) concentrations during the first 24 h, with a decrease in human tissue inhibitor of metalloproteinases-2 (TIMP-2) that remained after 10 days. An increase in human Interleukin-8 (IL-8) on the 10th day accompanied by high HGF was also noted. The incidence of myocardial injury and pulmonary thromboembolism was 55.8 and 20%, respectively. The incidence of in-hospital deaths was 16.3%. Biomarkers showed differences in severity of COVID-19. Syndecan-1, human platelet-derived growth factor (PDGF), VEGF, and Ang-2 predicted mortality. A multiple logistic regression model with TIMP-2 and PDGF had positive and negative predictive powers of 80.9 and 70%, respectively, for mortality. None of the biomarkers predicted myocardial injury or pulmonary thromboembolism. A proteome profiler array found changes in concentration in a large number of biomarkers of angiogenesis and chemoattractants. Finally, the serum samples from COVID-19 patients increased cell migration compared to that from healthy individuals. Conclusion: We observed that early endothelial and angiogenic biomarkers predicted mortality in patients with COVID-19. Chemoattractants from patients with COVID-19 increase the migration of endothelial cells. Trials are needed for confirmation, as this poses a therapeutic target for SARS-CoV-2.

Actualización en el tratamiento del síndrome de hipertensión intracraneana / Update on the management of intracranial hypertension syndrome

Elevated intracranial pressure (ICP) is a devastating complication, with great impact on neurological status and high morbidity and mortality. Intracranial hypertension (ICH) has multiple etiologies. The natural history of this condition can lead to brain death. The successful management of patients with elevated ICP (> 20-25 mmHg) requires fast and timely recognition, judicious use of invasive monitoring and therapies aimed to reversing its underlying cause. Therefore, it must be managed as a neurological emergency. The objective of this review is to present in a friendly way the diagnostic approach and the management of ICH, focused on general practitioners.

Association between preoperative serum lactate concentrate with tumor cell proliferative index in primary brain tumor.

BACKGROUND: Elevated preoperative lactate levels have been reported in patients admitted for resection of brain tumors. As histologic type and tumor grade have also been linked to lactate concentration, we hypothesized that preoperative lactate concentration in patients with brain tumors may be associated with tumor proliferation. We describe the relationship between preoperative plasma lactate levels, and the cell proliferation marker Ki-67 in brain tumor surgery. METHODS: In this cross-sectional study, records of patients who underwent craniotomy between June 2017 and February 2018 at our Hospital were reviewed to select glioma and meningioma cases in which lactate concentrations in plasma and degree of cell proliferation were registered. Bivariable and linear regression analyses were used to assess the association between lactate concentrations and the Ki-67 Index. RESULTS: Lactate concentrations in plasma and Ki-67 Index were available in 55 patients. Meningioma cases had a mean concentration of 1.2 (0.1) mmol/L compared to diffuse astrocytic and oligodendroglial tumors cases with 1.7 (0.1) mmol/L (P<0.01). Both variables had a low positive correlation in meningiomas (Spearman's r, 0.29; 95% CI, -0.10-0.61; P=0.13) and a high correlation in gliomas (Spearman's r, 0.64; 95% CI, 0.33-0.82; P<0.01). The pooled analysis showed a high correlation index (Spearman's r, 0.61; 95% CI, 0.40-0.76; P<0.01). A linear regression model showed that the Ki-67 Index explained 43% of the variation in lactate (P<0.01). CONCLUSIONS: Brain tumors with higher rates of cell proliferation have higher plasma lactate levels. In this scenario, lactate concentrations may not only reflect systemic perfusion.

Association Between Lower Preoperative Cognition With Intraoperative Electroencephalographic Features Consistent With Deep States of Anesthesia in Older Patients: An Observational Cohort Study.

BACKGROUND: Patients with low cognitive performance are thought to have a higher risk of postoperative neurocognitive disorders. Here we analyzed the relationship between preoperative cognition and anesthesia-induced brain dynamics. We hypothesized that patients with low cognitive performance would be more sensitive to anesthetics and would show differences in electroencephalogram (EEG) activity consistent with a brain anesthesia overdose. METHODS: This is a retrospective analysis from a previously reported observational study. We evaluated cognitive performance using the Montreal cognitive assessment (MoCA) test. All patients received general anesthesia maintained with sevoflurane or desflurane during elective major abdominal surgery. We analyzed the EEG using spectral, coherence, and phase-amplitude modulation analyses. RESULTS: Patients were separated into a low MoCA group (<26 points, n = 12) and a high MoCA group (n = 23). There were no differences in baseline EEG, nor end-tidal age-corrected minimum alveolar concentration (MACage). However, under anesthesia, the low MoCA group had lower α-ß power (high MoCA: 2.9 [interquartile range {IQR}: 0.6-5.8 dB] versus low MoCA: -1.2 [IQR: -2.1 to 0.6 dB], difference 4.1 [1.0-5.7]) and a lower α peak frequency (high MoCA: 9.0 [IQR: 8.3-9.8 Hz] versus low MoCA: 7.5 [IQR: 6.3-9.0 Hz], difference 1.5 [0-2.3]) compared to the high MoCA group. The low MoCA group also had a lower α band coherence and a stronger peak-max phase-amplitude coupling (PAC). Finally, patients in the low MoCA group had longer emergence times (high MoCA 663 ± 345 seconds versus low MoCA: 960 ± 352 seconds, difference 297 [15-578]). Multiple linear regression shows up that both age and MoCA scores are independently associated with intraoperative α-ß power. CONCLUSIONS: All these EEG features, together with a prolonged emergence time, are consistent with the possibility that older patients with low cognitive performance are receiving a brain anesthesia overdose compare to cognitive normal patients.

Experiencia de reconversión de un servicio clínico anestésico-quirúrgico en unidad de pacientes críticos COVID-19 en un hospital universitario / Experience of transforming a clinical surgical-anesthetic unit into a COVID-19 critical patient one in a teaching hospital

INTRODUCTION: The experience of restructuring a clinical surgical-anesthetic unit into a critical patient unit in charge of surgical- anesthetic personnel is presented during the period from May to July 2020 in the context of a SARS-CoV-2 pandemic. OBJECTIVES: Describe the unit's restructuring process, considering technical aspects, changes in staff functions, clinical outcomes of the patients, quality indicators obtained and the psychological impact on the healthcare team. MATHERIAL AND METHODS: The strategies implemented by the responsible experts were described (ie: engineering). Clinical data were obtained from an insti- tutional database and electronical medical records. The management of human resources was described using administrative records of the services of anesthesiology, OR and critical patient unit. The psychological impact on the unit staff was evaluated by applying the Maslach questionnaire. The quality of the clinical management of the unit was obtained from the compilation of standardized quality indicators for the critical patient units of the institution. RESULTS: 25 patients were admitted in the unit. The mean age was 62 ± 12 years. About the complications, 52% had pulmonary embolism, 36% had acute kidney injury, and 1 patient died. The prevalence of Burnout Syndrome was 73.6%. The occurrence of adverse events was minimal. DISCUSSION: The transformation of an anesthetic-surgical unit into a COVID critical patient one, demands a complex net of coordinated strategies to allow facing the attention demand with positive clinical results, at the expense of the health care team mental health.

INTRODUCCIÓN: Se presenta la experiencia de reconversión de una unidad de cuidados posanestésicos a una unidad de cuidados intensivos a cargo de personal anestésico-quirúrgico entre mayo y julio de 2020, en contexto de pandemia por SARS-CoV-2. OBJETIVOS: Describir el proceso de reconversión considerando aspectos técnicos, pertinentes al recurso humano, resultados clínicos, indicadores de calidad e impacto psicológico en el equipo de salud. MATERIALES Y MÉTODOS: Se describen las estrategias implementadas por los expertos responsables. Se obtienen datos clínicos desde base de datos institucional y ficha clínica electrónica. Se describe la gestión del recurso humano utilizando registros administrativos de los servicios involucrados. El impacto psicológico en el personal fue evaluado aplicando el cuestionario de Maslach. La calidad de la gestión clínica se obtiene a partir de indicadores de calidad estandarizados para las unidades de pacientes críticos de nuestro establecimiento. RESULTADOS: Se atendieron 25 pacientes en la unidad. La edad promedio fue 62 ± 12 años. El 52% presentó tromboembolismo pulmonar, 36% injuria renal aguda como complicación. Un paciente falleció. La prevalencia de síndrome de Burnout fue de 73,6%. La ocurrencia de eventos adversos fue baja. CONCLUSIONESConclusiones: La reconversión de una unidad anestésico-quirúrgica a una unidad crítica COVID-19, demanda un complejo entramado de estrategias coordinadas que permiten responder a la demanda de atención con resultados clínicos positivos, a expensas del costo de la salud mental del equipo de salud involucrado.

Reconocimiento de tres patrones básicos de movimiento de la mano utilizando electromiografía de superficie y algoritmos inteligentes / Identification of three basic hand movement patterns by surface electromyography and smart algorithms

Introducción: este artículo presenta la predicción de tres tipos de movimientos básicos de la mano mediante un algoritmo inteligente para extraer características imprescindibles para el reconocimiento de patrones de movimiento a partir del análisis de señales electromiográficas superficiales adquiridas con el dispositivo Myo. Objetivo: reconocer y predecir patrones básicos de movimiento de la articulación del brazo utilizando electromiografía de superficie para aplicarlo sobre un prototipo de prótesis. Métodos: se tomaron datos de 13 estudiantes de 22 y 23 años de la Universidad Politécnica Salesiana, cada uno de los cuales ejecutó tres tipos de agarre: cilíndrico, pinza y pinza planar. Se trabajó con una frecuencia de 10 Hz y se tomaron 5 muestras por tipo de agarre durante 60 segundos. Para el análisis estadístico de los datos se utilizó la herramienta Anova, estableciendo un valor de significancia mayor a 0,65. Resultados: En ciertos voluntarios hay una mayor reacción en el electrodo 1 debido a que su antebrazo es mayor. El tiempo de respuesta para el reconocimiento varía dependiendo del número de variables que se tenga que comparar. Cuando se analiza un solo movimiento es de 2,6 segundos, en cambio, cuando se analizan los 3 movimientos el tiempo de respuesta incrementa a 7,8 segundos por la cantidad de electrodos que se quieran analizar. Conclusiones: la respuesta del sistema propuesto empieza a ser más lenta a medida que se analizan más movimientos a la vez y por tanto, es menos efectiva. El tiempo de ejecución y respuesta de nuestro sistema, en comparación al estado del arte, es más alto, debido a que se utilizan menos métodos de caracterización de la señal. Adicionalemtne, una limitante del proyecto es la frecuencia de muestreo del dispositivo Myo (200Hz)(AU)

Introduction: the paper presents the prediction of three basic hand movement types by means of a smart algorithm to draw characteristics indispensable for identification of movement patterns based on the analysis of surface electromyographic signals obtained with the Myo device. Objective: recognize and predict basic movement patterns of the arm joint using surface electromyography with a view to applying them over a prosthesis prototype. Methods: data were taken from 13 students aged 22 and 23 years from the Salesian Polytechnic University, each of whom performed three types of grasp: cylindrical, pincer and palmar pincer. A 10 Hz frequency was used and 5 samples were taken of each grasp type during 60 seconds. Statistical analysis was performed with the tool ANOVA, establishing a significance value > 0.65. Results: in certain volunteers a greater reaction was observed in electrode 1, due to their larger forearms. Response time for identification varies with the number of variables to be compared. When only one movement is analyzed, response time is 2.6 seconds, but when the three movements are examined it rises to 7.8 seconds by the number of electrodes intended to be studied. Conclusions: the response of the system proposed starts to slow down as more movements are analyzed simultaneously, which makes it less effective. The performance and response time of our system is higher than in state-of-the-art systems, since fewer signal characterization methods are used. On the other hand, a limitation of the project is the sampling frequency of the Myo device (200 Hz)(AU)

Effect of sevoflurane and propofol on tourniquet-induced endothelial damage: a pilot randomized controlled trial for knee-ligament surgery.

BACKGROUND: The glycocalyx layer is a key structure in the endothelium. Tourniquet-induced ischemic periods are used during orthopedic surgery, and the reactive oxygen species generated after ischemia-reperfusion may mediate the shedding of the glycocalyx. Here, we describe the effects of tourniquet-induced ischemia-reperfusion and compare the effects of sevoflurane and propofol on the release of endothelial biomarkers after ischemia-reperfusion in knee-ligament surgery. METHODS: This pilot, single-center, blinded, randomized, controlled trial included 16 healthy patients. After spinal anesthesia, hypnosis was achieved with sevoflurane or propofol according to randomization. During the perioperative period, five venous blood samples were collected for quantification of syndecan-1, heparan sulfate, and thrombomodulin from blood serum by using ELISA assays kits. Sample size calculation was performed to detect a 25% change in the mean concentration of syndecan-1 with an alpha of 0.05 and power of 80%. RESULTS: For our primary outcome, a two-way ANOVA with post-hoc Bonferroni correction analysis showed no differences in syndecan-1 concentrations between the sevoflurane and propofol groups at any time point. In the sevoflurane group, we noted an increase in syndecan-1 concentrations 90 min after tourniquet release in the sevoflurane group from 34.6 ± 24.4 ng/mL to 47.9 ± 29.8 ng/mL (Wilcoxon test, p < 0.01) that was not observed in patients randomized to the propofol group. The two-way ANOVA showed no intergroup differences in heparan sulfate and thrombomodulin levels. CONCLUSIONS: Superficial endothelial damage without alterations in the cell layer integrity was observed after tourniquet knee-ligament surgery. There was no elevation in serum endothelial biomarkers in the propofol group patients. Sevoflurane did not show the protective effect observed in in vitro and in vivo studies. TRIAL REGISTRATION: The trial was registered in www.clinicaltrials.gov (ref: NCT03772054, Registered 11 December 2018).

Protocolos de recuperación acelerada después de cirugía ¿tienen espacio en nuestra práctica diaria actual? / Enhanced Recovery After Surgery (ERAS) protocols ¿is there a place in our clinical practice?

The ERAS protocols (Enhanced Recovery After Surgery or in Spanish, Recuperación Acelerada Después de Cirugía) are a set of multimodal perioperative strategies that aim to reduce the time of hospitalization, recovery, perioperative complications and costs associated with different surgical procedures. Multiple interventions are required for its implementation: anesthetic, surgical, kinesiological, nutritional and nursing interventions. There is a strong body of evidence supporting its application in the daily practice, but there are multiple barriers that have limited its development nationally and internationally. This review intends to appraise the state of the art of this topic, focusing on the anesthesiologist' role.

Los protocolos ERAS (Enhanced Recovery After Surgery o en español, Recuperación Acelerada Después de Cirugía) son un conjunto de estrategias multimodales del perioperatorio que tienen como objetivos el disminuir los tiempos de hospitalización, de recuperación, complicaciones perioperatorias y costos asociados a distintos procedimientos quirúrgicos. Para su implementación, requieren intervenciones anestésicas, quirúrgicas, kinesiológicas, nutricionales y de enfermería. Pese a que existe una amplia evidencia que avala su uso en nuestra práctica anestésica diaria, existen múltiples barreras que han limitado su desarrollo a nivel nacional e internacional. Presentamos una revisión de sus principales componentes y nos enfocamos en el rol que el anestesiólogo puede tener en su implementación.

Anesthetic Management of a Patient With Ongoing Thrombolytic Therapy During Decompressive Craniectomy: A Case Report.

Decompressive craniectomy (DC) is a therapeutic alternative for reducing intracranial pressure after a middle cerebral artery stroke. If thrombolytic therapy is administered, craniectomy is usually postponed for at least 24 hours due to a risk of severe bleeding. We describe a case in which DC was performed on a 38-year-old man who received thrombolytic therapy for an ischemic stroke involving the middle cerebral artery. His neurological and hemodynamic status worsened during its administration, and DC was performed 6 hours after thrombolysis was performed. Fibrinolytic coagulopathy was successfully managed by monitoring fibrinogen levels and with the administration of cryoprecipitate and tranexamic acid.

Encuesta Nacional sobre la utilización de catéter venoso central en pacientes sometidos a neurocirugía electiva en Chile / Use of central venous catheter in patients undergoing elective neurosurgery in Chile: A national survey

OBJECTIVES: To know, through an online survey, the usual clinical practice of Chilean anesthesiologists regarding central venous catheterization in patients undergoing elective neurosurgery. MATERIAL AND METHODS: An email was sent with a link to a questionnaire to anesthesiologists belonging to the Society of Anesthesiology of Chile (SACH). The questionnaire consisted of an anonymous questionnaire, with multiple-choice questions that included data referring to experience as an anesthesiologist, experience in neuroanesthesia, indication of central venous access in elective neurosurgery, access of choice, technique used, and immediate and late complications. RESULTS: A valid response was received to the online survey by 180 anesthesiologists, which represents a response rate of 50%. Only 14.4% of the respondents were classified as specialists in neuroanesthesia. The majority acces corresponded to the Internal Jugular. The main indication was the use of vasoactive drugs in 92.18%. Regarding clinical scenarios, 95.4% of respondents used a central venous route in posterior fossa surgery, while only 9.41% used it in minimally invasive surgery. 69.3% of the respondents indicated that they had presented an immediate complication related to the procedure, with arterial puncture being the most frequent with 72.1%. Protocols for perioperative management only existed in 17.8% of cases. There are no significant differences in the usual clinical practice among specialists in neuroanesthesia and general anesthesiologists in most of the items analyzed. CONCLUSIONS: From the data obtained, we observed that there is no uniform criterion in the indication, access and control of the central venous catheter in the context of elective neurosurgery. The foregoing could be explained by the scarce protocolization of anesthetic management in these surgeries. It is of interest to verify that there are no differences in clinical practice among anesthesiologists specialized in this area and those unusual in neurosurgical procedures.

OBJETIVOS: Conocer por medio de una encuesta online la práctica clínica habitual de los anestesiólogos chilenos respecto a la cateterización venosa central en pacientes sometidos a neurocirugía de carácter electivo. MATERIAL Y MÉTODOS: Se envió un correo electrónico con un enlace a un cuestionario a anestesiólogos pertenecientes a la Sociedad de Anestesiología de Chile (SACH). La encuesta consistía en un cuestionario de carácter anónimo, con preguntas de selección múltiple que incluía datos referidos a la experiencia como anestesiólogo, experiencia en neuroanestesia, indicación de vía venosa central en neurocirugía electiva, acceso de elección, técnica utilizada y complicaciones inmediatas y tardías. RESULTADOS: Se recibió respuesta válida a la encuesta online por parte de 180 anestesiólogos, lo que representa una tasa de respuesta del 50%. Sólo el 14,4% de los encuestados son catalogados como especialistas en neuroanestesia. La vía de acceso de elección corresponde a la Yugular Interna con un 66,8% de las preferencias. La principal indicación señalada para su utilización fue el uso de drogas vasoactivas en un 92,18% de los casos. Respecto a escenarios clínicos el 95,4% de los encuestados utiliza una vía venosa central en cirugía de fosa posterior, mientras que sólo el 9,41% la utiliza en cirugía mínimanente invasiva. El 69,3% de los encuestados indica haber presentado alguna vez una complicación inmediata relacionada al procedimiento, siendo la punción arterial la más frecuente con un 72,1%. Protocolos para el manejo perioperatorio sólo existían en 17,8% de los casos. No existen diferencias significativas en la práctica clínica habitual entre los especialistas en neuroanestesia y anestesiólogos poco habituados en neuroanestesia en la mayoría de los ítems analizados. CONCLUSIONES: A partir de los datos obtenidos por esta encuesta online, observamos que no existe un criterio uniforme en la indicación, vía de acceso y control del catéter venoso central en el contexto de la neurocirugía electiva. Lo anterior, podría explicarse por la escasa protocolización del manejo anestésico en estas cirugías. Es de interés comprobar que no existen grandes diferencias en la práctica clínica entre los anestesiólogos especialistas en esta área y aquellos poco habituales en procedimientos neuroquirúrgicos.

Aged blood factors decrease cellular responses associated with delayed gingival wound repair.

Aging is a gradual biological process characterized by a decrease in cell and organism functions. Gingival wound healing is one of the impaired processes found in old rats. Here, we studied the in vivo wound healing process using a gingival repair rat model and an in vitro model using human gingival fibroblast for cellular responses associated to wound healing. To do that, we evaluated cell proliferation of both epithelial and connective tissue cells in gingival wounds and found decreased of Ki67 nuclear staining in old rats when compared to their young counterparts. We next evaluated cellular responses of primary gingival fibroblast obtained from young subjects in the presence human blood serum of individuals of different ages. Eighteen to sixty five years old masculine donors were classified into 3 groups: "young" from 18 to 22 years old, "middle-aged" from 30 to 48 years old and "aged" over 50 years old. Cell proliferation, measured through immunofluorescence for Ki67 and flow cytometry for DNA content, was decreased when middle-aged and aged serum was added to gingival fibroblast compared to young serum. Myofibroblastic differentiation, measured through alpha-smooth muscle actin (α-SMA), was stimulated with young but not middle-aged or aged serum both the protein levels and incorporation of α-SMA into actin stress fibers. High levels of PDGF, VEGF, IL-6R were detected in blood serum from young subjects when compared to middle-aged and aged donors. In addition, the pro-inflammatory cytokines MCP-1 and TNF were increased in the serum of aged donors. In old rat wound there is an increased of staining for TNF compared to young wound. Moreover, healthy gingiva (non injury) shows less staining compared to a wound site, suggesting a role in wound healing. Moreover, serum from middle-aged and aged donors was able to stimulate cellular senescence in young cells as determined by the expression of senescence associated beta-galactosidase and histone H2A.X phosphorylated at Ser139. Moreover, we detected an increased frequency of γ-H2A.X-positive cells in aged rat gingival tissues. The present study suggests that serum factors present in middle-aged and aged individuals may be responsible, at least in part, for the altered responses observed during wound healing in aging.

Investigación acuícola en el altiplano boliviano, la

I. La vertiente cerrada del altiplano boliviano II. El centro de desarrollo piscícola y enseñanza técnica del altiplano "Tiquina-Pongo" III. Trabajos de investigación acuícola realizados en el centro de desarrollo piscícola y enseñanza técnica del altiplano "Tiquina-Pongo"