49 research outputs found
Bioactive pectic polysaccharides from bay tree pruning waste: Sequential subcritical water extraction and application in active food packaging
The potential isolation of bio-active polysaccharides from bay tree pruning waste was studied using sequential subcritical water extraction using different time-temperature combinations. The extracted polysaccharides were highly enriched in pectins while preserving their high molecular mass (10–100 kDa), presenting ideal properties for its application as additive in food packaging. Pectin-enriched chitosan films were prepared, improving the optical properties (=95% UV-light barrier capacity), antioxidant capacity (?95% radical scavenging activity) and water vapor permeability (=14 g·Pa-1·s-1·m-1·10-7) in comparison with neat chitosan-based films. Furthermore, the antimicrobial activity of chitosan was maintained in the hybrid films. Addition of 10% of pectins improved mechanical properties, increasing the Young's modulus 12%, and the stress resistance in 51%. The application of pectin-rich fractions from bay tree pruning waste as an additive in active food packaging applications, with triple action as antioxidant, barrier, and antimicrobial has been demonstrated.Authors would like to thank the Spanish Ministry of Science and
Innovation (Ramon y Cajal contract RYC-2015-17109) and Universidad
de Cordoba, ´ Spain (Predoctoral Grant 2019) for the financial support
during this work
How Donor and Surgical Factors Affect the Viability and Functionality of Human Hepatocytes Isolated From Liver Resections
Liver resections are a significant source of primary human hepatocytes used mainly in artificial liver devices and pharmacological and biomedical studies. However, it is not well known how patient-donor and surgery-dependent factors influence isolated hepatocytes’ yield, viability, and function. Hence, we aimed to analyze the impact of all these elements on the outcome of human hepatocyte isolation.
Patients and methods: Hepatocytes were isolated from liver tissue from patients undergoing partial hepatectomy using a two-step collagenase method. Hepatocyte viability, cell yield, adhesion, and functionality were measured. In addition, clinical and analytical patient variables were collected and the use or absence of vascular clamping and its type (continuous or intermittent) plus the ischemia times during surgery.
Results: Malignant disease, previous chemotherapy, and male gender were associated with lower hepatocyte viability and isolation cell yields. The previous increase in transaminases was also associated with lower yields on isolation and lower albumin production. Furthermore, ischemia secondary to vascular clamping during surgery was inversely correlated with the isolated hepatocyte viability. An ischemia time higher than 15 min was related to adverse effects on viability.
Conclusion: Several factors correlated with the patient and the surgery directly influence the success of human hepatocyte isolation from patients undergoing liver resection
A clinical decision web to predict ICU admission or death for patients hospitalised with Covid-19 using machine learning algorithms
The purpose of the study was to build a predictive model for estimating the risk of ICU admission or mortality among patients hospitalized with COVID-19 and provide a user-friendly tool to assist clinicians in the decision-making process. The study cohort comprised 3623 patients with confirmed COVID-19 who were hospitalized in the SALUD hospital network of Aragon (Spain), which includes 23 hospitals, between February 2020 and January 2021, a period that includes several pandemic waves. Up to 165 variables were analysed, including demographics, comorbidity, chronic drugs, vital signs, and laboratory data. To build the predictive models, different techniques and machine learning (ML) algorithms were explored: multilayer perceptron, random forest, and extreme gradient boosting (XGBoost). A reduction dimensionality procedure was used to minimize the features to 20, ensuring feasible use of the tool in practice. Our model was validated both internally and externally. We also assessed its calibration and provide an analysis of the optimal cut-off points depending on the metric to be optimized. The best performing algorithm was XGBoost. The final model achieved good discrimination for the external validation set (AUC = 0.821, 95% CI 0.787–0.854) and accurate calibration (slope = 1, intercept = −0.12). A cut-off of 0.4 provides a sensitivity and specificity of 0.71 and 0.78, respectively. In conclusion, we built a risk prediction model from a large amount of data from several pandemic waves, which had good calibration and discrimination ability. We also created a user-friendly web application that can aid rapid decision-making in clinical practice
Mortality and Causes of Death After Liver Transplantation: Analysis of Sex Differences in a Large Nationwide Cohort
In the last few years, several studies have analyzed sex and gender differences in liver transplantation (LT), but none have performed a disaggregated analysis of both mortality and causes of death. Data from 15,998 patients, 11,914 (74.5%) males and 4,069 (25.5%) females, transplanted between 2000 and 2016 were obtained from the Liver Transplantation Spanish Registry. Survival analysis was applied to explore recipient sex as a risk factor for death. The causes of death at different follow-up duration were disaggregated by recipient sex for analysis. Short-term survival was higher in males, whereas long-term survival was higher in females. Survival at 1, 5 and 10 years post-transplant was 87.43%, 73.83%, and 61.23%, respectively, in males and 86.28%, 74.19%, and 65.10%, respectively, in females (p = 0.05). Post-LT mortality related to previous liver disease also presented sex differences. Males had 37% increased overall mortality from acute liver failure (p = 0.035) and 37% from HCV-negative cirrhosis (p < 0.001). Females had approximately 16% increased mortality when the liver disease was HCV-positive cirrhosis (p = 0.003). Regarding causes of death, non-malignancy HCV+ recurrence (6.3% vs. 3.9% of patients; p < 0.001), was more frequently reported in females. By contrast, death because of malignancy recurrence (3.9% vs. 2.2% of patients; p = 0.003) and de novo malignancy (4.8% vs. 2.5% of patients; p < 0.001) were significantly more frequent in male recipients. Cardiovascular disease, renal failure, and surgical complications were similar in both. In summary, male patients have lower short-term mortality than females but higher long-term and overall mortality. In addition, the post-LT mortality risk related to previous liver disease and the causes of mortality differ between males and females
Changes in severity, mortality, and virus genome among a Spanish cohort of patients hospitalized with SARS-CoV-2
Comparing pandemic waves could aid in understanding the evolution of COVID-19. The objective of the present study was to compare the characteristics and outcomes of patients hospitalized for COVID-19 in different pandemic waves in terms of severity and mortality. We performed an observational retrospective cohort study of 5,220 patients hospitalized with SARS-CoV-2 infection from February to September 2020 in Aragon, Spain. We compared ICU admissions and 30-day mortality, clinical characteristics, and risk factors of the first and second waves of COVID-19. The SARS-CoV-2 genome was also analyzed in 236 samples. Patients in the first wave (n¿=¿2,547) were older (median age 74 years [IQR 60–86] vs. 70 years [53–85]; p¿<¿0.001) and had worse clinical and analytical parameters related to severe COVID-19 than patients in the second wave (n¿=¿2,673). The probability of ICU admission at 30 days was 16% and 10% (p¿<¿0.001) and the cumulative 30-day mortality rates 38% and 32% in the first and second wave, respectively (p¿=¿0.007). Survival differences were observed among patients aged 60 to 80 years. We also found some variability among death risk factors and the viral genome between waves. Therefore, the two analyzed COVID-19 pandemic waves were different in terms of disease severity and mortality
Identification and functional analysis of missense mutations in the lecithin cholesterol acyltransferase gene in a Chilean patient with hypoalphalipoproteinemia
Lecithin-cholesterol acyltransferase (LCAT) is a plasma enzyme that esterifies cholesterol in high- and
low-density lipoproteins (HDL and LDL). Mutations in LCAT gene causes familial LCAT deficiency, which is
characterized by very low plasma HDL-cholesterol levels (Hypoalphalipoproteinemia), corneal opacity and anemia,
among other lipid-related traits. Our aim is to evaluate clinical/biochemical features of a Chilean family with a
proband showing clinical signs of familial LCAT deficiency, as well as to identify and assess the functional effects of
LCAT mutations. LCAT sequencing identified rare p.V333 M and p.M404 V missense mutations in compound heterozygous
state in the proband, as well the common synonymous p.L363 L variant. LCAT protein was detected in proband’s
plasma, but with undetectable enzyme activity compared to control relatives. HEK-293 T transfected cells with
vector expression plasmids containing either p.M404 V or p.V333 M cDNA showed detectable LCAT protein
expression both in supernatants and lysates from cultured cells, but with much lower enzyme activity compared to
cells transfected with the wild-type sequence. Bioinformatic analyses also supported a causal role of such rare
variations in LCAT lack of function. Additionally, the proband carried the minor allele of the synonymous p.L363 L
variant. However, this variant is unlikely to affect the clinical phenotype of the proband given its relatively high
frequency in the Chilean population (4%) and its small putative effect on plasma HDL-cholesterol levels.
Conclusion: Genetic, biochemical, in vitro and in silico analyses indicate that the rare mutations p.M404 V and p.
V333 M in LCAT gene lead to suppression of LCAT enzyme activity and cause clinical features of familial LCAT
deficiency.This work was supported by Proyecto FONDECYT 1150416 and Proyecto
Interdisciplina VRI-PUC II15024 from the Dirección de Investigación, Pontificia
Universidad Católica de Chile. Genotyping of GOCS was performed in the in
the Human Genotyping laboratory at the Spanish National Cancer Research
Centre, a member of CeGen (PRB2-ISCIII), and was supported by grant PT13/
0001/0005 of PE I + D + i 2013-2016 funded by ISCIII and ERDF (Fondo Europeo
de Desarrollo Regional). This research was partially supported by the
supercomputing infrastructure of the NLHPC (ECM-02). L.V. and C.B. were
supported by VRI, Pontificia Universidad Católica de Chile (Proyecto Investigación
Interdisciplinaria VRI-PUC II15024). TG was supported by “Beca de Magíster
Nacional” CONICYT. L.V. was additionally supported by FONDECYT postdoctoral grant 3170038. We express our gratitude to the proband and
relatives
Herramientas informáticas orientadas a la enseñanza y el aprendizaje
El amplio abanico de posibilidades tecnológicas disponible en la actualidad no siempre es aprovechado al máximo en el contexto educativo. En esta línea de investigación se propone explotar nuevas formas de aplicar los recursos disponibles para facilitar tanto al docente la transmisión del conocimiento así como al alumno poder adquirirlo, buscando desarrollar nuevas herramientas informáticas que simplifiquen el armado del material usado tanto dentro de sus clases así como de referencia para su posterior estudio fuera del aula. También se proponen herramientas orientadas a aportar dinamismo a las explicaciones del docente, aprovechando la disponibilidad de computadoras cada vez más potentes que permiten la obtención de resultados casi instantáneos al realizar tareas complejas, buscando así clases que sean interactivas, donde la participación de los alumnos adquiera un rol protagónico y no solo sean receptores en una comunicación unidireccional.Eje: Tecnología Informática Aplicada en EducaciónRed de Universidades con Carreras en Informática (RedUNCI
Herramientas informáticas orientadas a la enseñanza y el aprendizaje
El amplio abanico de posibilidades tecnológicas disponible en la actualidad no siempre es aprovechado al máximo en el contexto educativo. En esta línea de investigación se propone explotar nuevas formas de aplicar los recursos disponibles para facilitar tanto al docente la transmisión del conocimiento así como al alumno poder adquirirlo, buscando desarrollar nuevas herramientas informáticas que simplifiquen el armado del material usado tanto dentro de sus clases así como de referencia para su posterior estudio fuera del aula. También se proponen herramientas orientadas a aportar dinamismo a las explicaciones del docente, aprovechando la disponibilidad de computadoras cada vez más potentes que permiten la obtención de resultados casi instantáneos al realizar tareas complejas, buscando así clases que sean interactivas, donde la participación de los alumnos adquiera un rol protagónico y no solo sean receptores en una comunicación unidireccional.Eje: Tecnología Informática Aplicada en EducaciónRed de Universidades con Carreras en Informática (RedUNCI
Herramientas informáticas orientadas a la enseñanza y el aprendizaje
El amplio abanico de posibilidades tecnológicas disponible en la actualidad no siempre es aprovechado al máximo en el contexto educativo. En esta línea de investigación se propone explotar nuevas formas de aplicar los recursos disponibles para facilitar tanto al docente la transmisión del conocimiento así como al alumno poder adquirirlo, buscando desarrollar nuevas herramientas informáticas que simplifiquen el armado del material usado tanto dentro de sus clases así como de referencia para su posterior estudio fuera del aula. También se proponen herramientas orientadas a aportar dinamismo a las explicaciones del docente, aprovechando la disponibilidad de computadoras cada vez más potentes que permiten la obtención de resultados casi instantáneos al realizar tareas complejas, buscando así clases que sean interactivas, donde la participación de los alumnos adquiera un rol protagónico y no solo sean receptores en una comunicación unidireccional.Eje: Tecnología Informática Aplicada en EducaciónRed de Universidades con Carreras en Informática (RedUNCI
Waiting time dictates impact of frailty: A Spanish multicenter prospective study
Background & aims: Frailty is prevalent in liver transplant (LT) candidates. It is considered an independent predictor of adverse outcomes pre- and post-transplant according to data obtained in the United States. We aimed to externally validate the liver frailty index (LFI) in a multicenter cohort of LT candidates.
Methods: Outpatients with cirrhosis were prospectively recruited from five Spanish centers (2018-2020). Patients were defined as "frail" by an optimal cut-off of LFI ≥4.5. Patients were followed for at least 6 months to study associations of pre-LT frailty with pre- and post-transplant mortality, length of hospital and intensive care unit (ICU) stays, risk of early (<30 days) and late (30-90 days) post-transplant complications, retransplantation and cardiovascular events.
Results: Of 212 patients included, 45 patients (21%) were frail pre-LT, and the median LFI was 3.9 (IQR 3.5-4.4). After a median waiting time of 78 days, 2% died or were delisted for clinical worsening. The LFI at baseline was not predictive of mortality/delisting in LT candidates in univariable or multivariable analyses after adjusting for age and MELD-Na score (hazard ratio 1.48; p = 0.586). In contrast, compared to non-frail patients, frail LT candidates had a significantly higher length of hospital stay (9 vs. 13 days; p = 0.001) and rate of early (<30 days) post-transplant complications (55% vs. 100%; p = 0.021).
Conclusions: In the context of a short LT waiting time, frailty does not impact pretransplant mortality and/or delisting. In contrast, LT frailty is predictive of higher post-transplant complication rates and length of hospital stay. Whether strategies aimed at pre- and/or re-habilitation are beneficial in settings with short waiting times needs to be confirmed in prospective studies.
Impact and implications: Literature is scarce on the actual impact of physical frailty on adverse outcomes in the liver transplant scenario outside North America. Evidence-based justification to extend the use of objective frailty tools in the decision-making processes in other liver transplant settings is needed. This study is the first to evaluate the predictive value of the liver frailty index in outpatients in the European liver transplant setting, showing that in a low MELD, high access system, frailty does not impact pretransplant mortality and/or delisting but is predictive of higher complication rates and longer post-transplant length of stay. In practical ways, physicians should consider physical frailty as a vital sign to be measured systematically and routinely during clinic visits; researchers are encouraged to initiate prospective studies to evaluate the benefit of applying strategies aimed at pre- and or re-habilitation in liver transplant settings with short waiting times