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Planting floral resources is a common strategy for increasing the abundance and diversity of beneficial flower-visiting insects in human-modified systems. However, the context of the local area and surrounding landscape may affect the attractiveness of these floral resource provisioning plots. We compared the relative effects of local floral resources and surrounding urban land-use on the abundance of bees on flowering plants in common gardens in eastern Tennessee, USA. We planted four types of common garden plots at each of five different landscapes representing a variety of surrounding land use: 1) Urban Garden, 2) Forage Grassland, 3) Mixed Agriculture, 4) Forest, and 5) Organic Farm. Each common garden plot type had a fixed plant community representing one of three plant families (Asteraceae, Fabaceae, Lamiaceae) or a mix of all three, and all four common gardens were replicated at all the sites. We concurrently sampled bees in the garden plots and in a 50 m radius (local area) around the garden plots. We found that the size of the floral display (i.e. the visual display size of flowers) and diversity of flowers in the local area did not affect bee abundance or species richness in the garden plots. Although there was a significant positive association between developed land use in a 2 km radius and bee abundance in the gardens, the effect was small, and there was no relationship between land use and bee abundance or species richness in the local area. There were significant differences in the composition of the bee community between the local area and garden plots, but the largest determinants of bee community composition and species richness in the gardens were floral display size and variation in the garden plant species in bloom. This finding is promising for anyone wishing to promote pollinator populations by providing more floral resources.
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Flores , Abejas/fisiología , Animales , Jardines , Polinización , Biodiversidad , Tennessee , Ecosistema , Agricultura/métodosRESUMEN
The use of Digital Healthcare Products is leading to significant improvements in clinical practice. Herein, we discuss the development of PROACT 2.0 (Patient Reported Opinions About Clinical Tolerability v2.0), a novel open-source mobile and web application developed at Fondazione IRCCS Istituto Nazionale Tumori in Milan. It was developed in collaboration with The Christie, Manchester, in the context of work package 2 of the UpSMART Accelerator project, involving a consortium of referral cancer centers from the UK, Spain and Italy. PROACT 2.0 enhances communication between patients and healthcare providers in cancer clinical trials, allowing patients to report adverse events and side effects, and healthcare teams to collect valuable patient-reported outcome measures for treatment management. PROACT 2.0 supports text, audio, and video messaging, offering a secure, non-urgent communication channel that integrates with, or replaces, traditional methods. Its user-friendly and multilingual interface provides a new route for patient engagement and streamlines the handling of logistical information. Positive feedback from initial testing warrants future enhancements for broader applicability in cancer research and treatment.
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Ensayos Clínicos como Asunto , Comunicación , Relaciones Médico-Paciente , Humanos , Neoplasias/terapia , Medición de Resultados Informados por el Paciente , Aplicaciones Móviles , ItaliaRESUMEN
Thymic epithelial tumors (TETs) are rare mediastinal cancers originating from the thymus, classified in two main histotypes: thymoma and thymic carcinoma (TC). TETs affect a primary lymphoid organ playing a critical role in keeping T-cell homeostasis and ensuring an adequate immunological tolerance against "self". In particular, thymomas and not TC are frequently associated with autoimmune diseases (ADs), with Myasthenia Gravis being the most common AD present in 30% of patients with thymoma. This comorbidity, in addition to negatively affecting the quality and duration of patients' life, reduces the spectrum of the available therapeutic options. Indeed, the presence of autoimmunity represents an exclusion criteria for the administration of the newest immunotherapeutic treatments with checkpoint inhibitors. The pathophysiological correlation between TETs and autoimmunity remains a mystery. Several studies have demonstrated the presence of a residual and active thymopoiesis in adult patients affected by thymomas, especially in mixed and lymphocytic-rich thymomas, currently known as type AB and B thymomas. The aim of this review is to provide the state of art in regard to the histological features of the different TET histotype, to the role of the different immune cells infiltrating tumor microenvironments and their impact in the break of central immunologic thymic tolerance in thymomas. We discuss here both cellular and molecular immunologic mechanisms inducing the onset of autoimmunity in TETs, limiting the portfolio of therapeutic strategies against TETs and greatly impacting the prognosis of associated autoimmune diseases.
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Miastenia Gravis , Neoplasias Glandulares y Epiteliales , Timoma , Neoplasias del Timo , Adulto , Humanos , Autoinmunidad , Neoplasias del Timo/complicaciones , Neoplasias Glandulares y Epiteliales/terapia , Neoplasias Glandulares y Epiteliales/complicaciones , Microambiente TumoralRESUMEN
Aim: Cell microenvironment contains a plethora of information that influences cell modulation. Indeed, the extracellular matrix plays a central role in tissue development. Reproducing the cell-extracellular matrix crosstalk able to recapitulate both physical and biochemical signals is crucial to obtain functional tissue models or regenerative strategies. Materials & methods: Here, a combined method is proposed to easily functionalize collagen surface films, tailoring morphological properties. Oxygen nonthermal plasma treatment and glyco-conjugation with chondroitin sulfate are used to modify surface properties. Results: It results in higher adhesion, proliferation and morphological organization of U87 glioblastoma cells. Conclusion: Our finding suggests new promising strategies for the development of collagen-based biomaterials, which can be employed for advanced in vitro models.
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Sulfatos de Condroitina , Colágeno , Colágeno/química , Matriz Extracelular/química , Materiales Biocompatibles/químicaRESUMEN
Chitosan and its derivatives are interesting biopolymers for different field of analytical chemistry, especially in separation techniques. The present study was aimed at testing chitosan water soluble derivatives as dynamic coating agents for application to capillary electrophoresis. In particular, chitosan was modified following three different chemical reactions (nucleophilic substitution, reductive amination, and condensation) to introduce differences in charge and steric hindrance, and to assess the effect of these physico-chemical properties in capillary electrophoresis. The effects were tested on the capillary electrophoretic separation of the glycoforms of human transferrin, an important iron-transporting serum protein, one of which, namely disialo-transferrin (CDT), is a biomarker of alcohol abuse. Chitosan derivatives were characterized by using NMR and 1H NMR, HP-SEC-TDA, DLS, and rheology. The use of these compounds as dynamic coatings in the electrolyte running buffer in capillary electrophoresis was tested assessing the peak resolution of the main glycoforms of human transferrin and particularly of disialo-transferrin. The results showed distinct changes of the peak resolution produced by the different derivatives. The best results in terms of peak resolution were achieved using polyethylene glycol (PEG)-modified chitosan, which, in comparison to a reference analytical approach, provided an almost baseline resolution of disialo-transferrin from the adjacent peaks.
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Quitosano , Transferrina , Humanos , Transferrina/química , Electroforesis Capilar/métodos , Polietilenglicoles , PolietilenosRESUMEN
Background: Mutualistic interactions between plants and their pollinating insects are critical to the maintenance of biodiversity. However, we have yet to demonstrate that we are able to manage the structural properties of these networks for the purposes of pollinator conservation and preserving functional outcomes, such as pollination services. Our objective was to explore the extent of our ability to experimentally increase, decrease, and maintain connectance, a structural attribute that reflects patterns of insect visitation and foraging preferences. Patterns of connectance relate to the stability and function of ecological networks. Methods: We implemented a 2-year field experiment across eight sites in urban Dublin, Ireland, applying four agrochemical treatments to fixed communities of seven flowering plant species in a randomized block design. We spent ~117 h collecting 1,908 flower-visiting insects of 92 species or morphospecies with standardized sampling methods across the 2 years. We hypothesized that the fertilizer treatment would increase, herbicide decrease, and a combination of both maintain the connectance of the network, relative to a control treatment of just water. Results: Our results showed that we were able to successfully increase network connectance with a fertilizer treatment, and maintain network connectance with a combination of fertilizer and herbicide. However, we were not successful in decreasing network connectance with the herbicide treatment. The increase in connectance in the fertilized treatment was due to an increased species richness of visiting insects, rather than changes to their abundance. We also demonstrated that this change was due to an increase in the realized proportion of insect visitor species rather than increased visitation by common, generalist species of floral visitors. Overall, this work suggests that connectance is an attribute of network structure that can be manipulated, with implications for management goals or conservation efforts in these mutualistic communities.
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Fertilizantes , Herbicidas , Animales , Insectos , Polinización , PlantasRESUMEN
(1) Background: Venous thromboembolism (VTE) is a frequent complication in ambulatory lung cancer patients during chemotherapy and is associated with increased mortality. (2) Methods: We analyzed 568 newly diagnosed metastatic lung cancer patients prospectively enrolled in the HYPERCAN study. Blood samples collected before chemotherapy were tested for thrombin generation (TG) and a panel of hemostatic biomarkers. The Khorana risk score (KRS), new-Vienna CATS, PROTECHT, and CONKO risk assessment models (RAMs) were applied. (3) Results: Within 6 months, the cumulative incidences of VTE and mortality were 12% and 29%, respectively. Patients with VTE showed significantly increased levels of D-dimer, FVIII, prothrombin fragment 1 + 2, and TG. D-dimer and ECOG performance status were identified as independent risk factors for VTE and mortality by multivariable analysis and utilized to generate a risk score that provided a cumulative incidence of VTE of 6% vs. 25%, death of 19% vs. 55%, and in the low- vs. high-risk group, respectively (p < 0.001). While all published RAMs significantly stratified patients for risk of death, only the CATS and CONKO were able to stratify patients for VTE. (4) Conclusions: A new prediction model was generated to stratify lung cancer patients for VTE and mortality risk, where other published RAMs failed.
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The development of human tissue models for regenerative medicine and animal-free drug screening requires glycosylated biomaterials such as collagen. An easy and fast biomaterial glycosylation method exploiting Horseradish Peroxidase (HRP) phenol coupling reaction is proposed. The protocol is adaptable to any polymer functionalized with phenol residues or tyrosine containing proteins. As a model the tyrosine residues on collagen films were functionalized with salidroside, a natural ß-glucoside with a phenol in the aglycone. Scanning Electron Microscope (SEM) and contact angle analysis revealed the influence of glycosylation on the sample's morphology and wettability. Preliminary biological evaluation showed the cytocompatibility of the glucosylated collagen films.
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Fenoles , Tirosina , Humanos , Peroxidasa de Rábano Silvestre/química , Peroxidasa de Rábano Silvestre/metabolismo , Fenol , ColágenoRESUMEN
Medellín fue considerada la ciudad más violenta del mundo durante los años noventa con una tasa de homicidios superior a 370 por cada 100 000 habitantes. En las últimas tres décadas, los asesinatos en la ciudad disminuyeron en un 90 %. Esta transformación ha sido celebrada internacionalmente como un ejemplo de gobernanza local exitosa de centros urbanos que sufren altos índices criminales. Ahora bien, este artículo sostiene que dicha recuperación catalogada por algunos como "milagro" no fue sólo producto de acciones exitosas del gobierno local, sino también el resultado de dos factores más: primero, la política del Estado colombiano a nivel nacional para fortalecer su aparato de seguridad y desmantelar grupos ilegales armados; y segundo, los acuerdos informales entre las autoridades y las bandas locales, así como la decisión de estas últimas de evitar confrontaciones violentas para facilitar la extracción de sus rentas ilegales.
Medellín was considered the most violent city in the world during the 1990s with a homicide rate of over 370 per 100 000 inhabitants. In the last three decades, murders in the city have decreased by 90 %. This transformation has been celebrated internationally as an example of successful local governance of urban centres suffering from high crime rates. However, this article argues that this recovery - labelled by some as a "miracle" - was not only the product of successful local government actions, but also the result of two other factors: first, the Colombian state's policy at the national level to strengthen its security apparatus and dismantle illegal armed groups; and second, the informal agreements between the authorities and local gangs, as well as the latter's decision to avoid violent confrontations in order to facilitate the extraction of their illegal rents.
Medellín foi considerada a cidade mais violenta do mundo durante a década de 1990, com uma taxa de homicídios superior a 370 por 100 000 habitantes. Nas últimas três décadas, os assassinatos na cidade diminuíram 90 %. Esta transformação tem sido celebrada internacionalmente como um exemplo de governação local bem-sucedida de centros urbanos que sofrem de elevadas taxas de criminalidade. Ora, este artigo sustenta que esta recuperação catalogada por alguns como um "milagre" não foi apenas o produto de ações bem-sucedidas do governo local, mas também o resultado de mais dois fatores: primeiro, a política do Estado colombiano no a nível nacional para reforçar o seu aparelho de segurança e desmantelar grupos armados ilegais; e em segundo lugar, os acordos informais entre as autoridades e os gangues locais, bem como a decisão destes últimos de evitar confrontos violentos para facilitar a extracção das suas rendas ilegais.
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Humanos , ColombiaRESUMEN
Thrombosis is a common complication of advanced cancer, yet the cellular mechanisms linking malignancy to thrombosis are poorly understood. The unfolded protein response (UPR) is an ER stress response associated with advanced cancers. A proteomic evaluation of plasma from patients with gastric and non-small cell lung cancer who were monitored prospectively for venous thromboembolism demonstrated increased levels of UPR-related markers in plasma of patients who developed clots compared with those who did not. Release of procoagulant activity into supernatants of gastric, lung, and pancreatic cancer cells was enhanced by UPR induction and blocked by antagonists of the UPR receptors inositol-requiring enzyme 1α (IRE1α) and protein kinase RNA-like endoplasmic reticulum kinase (PERK). Release of extracellular vesicles bearing tissue factor (EVTFs) from pancreatic cancer cells was inhibited by siRNA-mediated knockdown of IRE1α/XBP1 or PERK pathways. Induction of UPR did not increase tissue factor (TF) synthesis, but rather stimulated localization of TF to the cell surface. UPR-induced TF delivery to EVTFs was inhibited by ADP-ribosylation factor 1 knockdown or GBF1 antagonism, verifying the role of vesicular trafficking. Our findings show that UPR activation resulted in increased vesicular trafficking leading to release of prothrombotic EVTFs, thus providing a mechanistic link between ER stress and cancer-associated thrombosis.
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Carcinoma de Pulmón de Células no Pequeñas , Neoplasias Pulmonares , Neoplasias Pancreáticas , Humanos , Proteínas Serina-Treonina Quinasas/metabolismo , Endorribonucleasas/genética , Proteómica , Tromboplastina/metabolismo , Respuesta de Proteína Desplegada , Neoplasias Pancreáticas/complicaciones , Factores de Intercambio de Guanina Nucleótido/metabolismoRESUMEN
BACKGROUND Despite being considered a disease of the past, pediatric scurvy is increasingly reported in developed countries, especially among children with autism spectrum disorder, developmental delays, or a restrictive diet. Pediatric patients typically present with lower extremity pain or refusal to walk. This case study features an atypical presentation of scurvy in a non-ambulatory patient. CASE REPORT A 14-year-old boy with arthrogryposis multiplex congenita displayed a late-stage scurvy symptom: a necrotic gastrostomy tube site, indicative of poor wound healing due to vitamin C deficiency. The usual telltale symptoms of scurvy were camouflaged due to his non-ambulatory status, which may have contributed to a delayed presentation. Nevertheless, a comprehensive clinical evaluation, incorporating diet history, gingival symptoms, petechiae, and characteristic radiological signs, eventually led to the correct diagnosis. Although acute osteomyelitis was initially suspected, it was subsequently ruled out. Upon initiation of vitamin C therapy, the patient's symptoms subsided within a few days, and the necrotic tissue surrounding the gastrostomy tube healed completely within two weeks. CONCLUSIONS The highlighted case underscores the importance of including scurvy in the differential diagnosis for pediatric patients with lower extremity pain without fever. A detailed dietary history focusing on vitamin C intake is crucial during clinical evaluation. Early initiation of vitamin C therapy, when scurvy is suspected, may prevent unnecessary and extensive diagnostic workup for other potential causes, offering timely relief to the patient.
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Trastorno del Espectro Autista , Escorbuto , Masculino , Humanos , Niño , Adolescente , Escorbuto/diagnóstico , Escorbuto/tratamiento farmacológico , Ácido Ascórbico/uso terapéutico , Gastrostomía , DolorRESUMEN
Background: Pollinating insects provide economically and ecologically valuable services, but are threatened by a variety of anthropogenic changes. The availability and quality of floral resources may be affected by anthropogenic land use. For example, flower-visiting insects in agroecosystems rely on weeds on field edges for foraging resources, but these weeds are often exposed to agrochemicals that may compromise the quality of their floral resources. Methods: We conducted complementary field and greenhouse experiments to evaluate the: (1) effect of low concentrations of agrochemical exposure on nectar and pollen quality and (2) relationship between floral resource quality and insect visitation. We applied the same agrochemcial treatments (low concentrations of fertilizer, low concentrations of herbicide, a combination of both, and a control of just water) to seven plant species in the field and greenhouse. We collected data on floral visitation by insects in the field experiment for two field seasons and collected pollen and nectar from focal plants in the greenhouse to avoid interfering with insect visitation in the field. Results: We found pollen amino acid concentrations were lower in plants exposed to low concentrations of herbicide, and pollen fatty acid concentrations were lower in plants exposed to low concentrations of fertilizer, while nectar amino acids were higher in plants exposed to low concentrations of either fertilizer or herbicide. Exposure to low fertilizer concentrations also increased the quantity of pollen and nectar produced per flower. The responses of plants exposed to the experimental treatments in the greenhouse helped explain insect visitation in the field study. The insect visitation rate correlated with nectar amino acids, pollen amino acids, and pollen fatty acids. An interaction between pollen protein and floral display suggested pollen amino acid concentrations drove insect preference among plant species when floral display sizes were large. We show that floral resource quality is sensitive to agrochemical exposure and that flower-visiting insects are sensitive to variation in floral resource quality.
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Herbicidas , Néctar de las Plantas , Animales , Fertilizantes , Polinización/fisiología , Polen , Insectos/fisiología , Malezas , Agroquímicos , AminoácidosRESUMEN
Upon antigen-specific T cell receptor (TCR) engagement, human CD4+ T cells proliferate and differentiate, a process associated with rapid transcriptional changes and metabolic reprogramming. Here, we show that the generation of extramitochondrial pyruvate is an important step for acetyl-CoA production and subsequent H3K27ac-mediated remodeling of histone acetylation. Histone modification, transcriptomic, and carbon tracing analyses of pyruvate dehydrogenase (PDH)-deficient T cells show PDH-dependent acetyl-CoA generation as a rate-limiting step during T activation. Furthermore, T cell activation results in the nuclear translocation of PDH and its association with both the p300 acetyltransferase and histone H3K27ac. These data support the tight integration of metabolic and histone-modifying enzymes, allowing metabolic reprogramming to fuel CD4+ T cell activation. Targeting this pathway may provide a therapeutic approach to specifically regulate antigen-driven T cell activation.
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Ensamble y Desensamble de Cromatina , Histonas , Humanos , Histonas/metabolismo , Acetilcoenzima A/metabolismo , Linfocitos T CD4-Positivos/metabolismoRESUMEN
INTRODUCTION: Coronavirus disease is a clinical challenge for patients with autoimmune conditions. Patients affected by immune thrombotic thrombocytopenic purpura (iTTP) are particularly vulnerable to SARS-CoV-2 infection. Protecting these patients with vaccination is therefore mandatory, although concerns may exist on a possible increased thrombotic risk or risk of disease relapse after vaccine exposure. So far, there is no information on serological response and hemostatic activation in iTTP patients after SARS-CoV-2 vaccination. MATERIALS AND METHODS: In this study, in April 2021, we enrolled iTTP patients in clinical remission and on regular outpatient follow-up to receive the first and second dose BNT162b2 vaccine as a part of a prospective trial aimed at monitoring for 6 months after vaccination the occurrence of subclinical laboratory signs of clotting activation, as well as overt thrombotic complications or disease relapse. The seroconversion response was monitored in parallel. The results were compared with those of control non-iTTP subjects. RESULTS: A moderate decrease of ADAMTS-13 activity was recorded at 3 and 6 months in five patients with normal values at baseline, while an ADAMTS-13 relapse occurred at 6 months in one patient. Abnormalities in the endothelium activation biomarkers postvaccination were observed in iTTP patients compared with controls. The immunological response to vaccine was overall positive. No clinical iTTP relapses or thrombotic events manifested in the 6 month-follow-up after vaccination. CONCLUSION: The results of this study are in favor of efficacy and safety of mRNA vaccines in patients with iTTP, and highlight the importance of long-term monitoring of iTTP patients.
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COVID-19 , Hemostáticos , Púrpura Trombocitopénica Idiopática , Púrpura Trombocitopénica Trombótica , Vacunas , Humanos , Estudios Prospectivos , Proteína ADAMTS13 , Vacuna BNT162 , Vacunas contra la COVID-19/efectos adversos , SARS-CoV-2 , RecurrenciaRESUMEN
Meniscal lesions in skeletally immature patients can lead to joint degradation and knee instability. Meniscal allograft transplant (MAT) surgery is a solution to maintain knee stability. There is a lack of consensus on MAT surgery outcomes in pediatric patients. A systematic review was conducted according to the PRISMA guidelines. PubMed, Scopus and EMBASE databases were searched from 1965 to June 2022. Studies were evaluated using the Newcastle-Ottawa Scale (NOS). Three studies were selected, and 58 patients were included (mean age 15.9 years) in total. The lateral meniscus was involved in 82.8% of all MAT surgeries. Post-meniscectomy syndrome and discoid meniscus were the main indications for MAT surgery. All studies reported improved subjective clinical scores and levels of sport after the surgery. The complication rate was 27.5%. Partial meniscectomy, meniscus knot removal, chondral defect treatment and lysis of adhesions were the most frequent procedures performed during reoperation. MAT surgery can improve clinical outcomes in pediatric patients with strictly selected indications. MAT surgery is safe when there are no limb asymmetries or malalignments, but it remains a challenging procedure with a high complication rate. Long-term follow-up is needed for definitive statements on the use of MAT in skeletally immature patients.
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BACKGROUND: Risk assessment models (RAMs) are relevant approaches to identify cancer outpatients at high risk of venous thromboembolism (VTE). Among the proposed RAMs, the Khorana (KRS) and the new-Vienna CATS risk scores have been externally validated in ambulatory patients with cancer. OBJECTIVES: To test KRS and new-Vienna CATS scores in 6-month VTE prediction and mortality in a large prospective cohort of metastatic cancer outpatients during chemotherapy. PATIENTS/METHODS: Newly diagnosed patients with metastatic non-small cell lung, colorectal, gastric, or breast cancers were analyzed (n = 1286). The cumulative incidence of objectively confirmed VTE was estimated with death as a competing risk and multivariate Fine and Gray regression. RESULTS: Within 6 months, 120 VTE events (9.7%) occurred. The KRS and the new-Vienna CATS scores showed comparable c-stat. Stratification by KRS provided VTE cumulative incidences of 6.2%, 11.4%, and 11.5% in the low-, intermediate-, and high-risk categories, respectively (p = ns), and of 8.5% vs. 11.8% (p = ns) in the low- vs. high-risk group by the single 2-point cut-off value stratification. Using a pre-defined 60-point cut-off by the new-Vienna CATS score, 6.6% and 12.2% cumulative incidences were obtained in the low- and high-risk groups, respectively (p < 0.001). Furthermore, having a KRS ≥2 = or a new-Vienna CATS score >60 points was also an independent risk factor for mortality. CONCLUSION: In our cohort, the 2 RAMs showed a comparable discriminating potential; however, after the application of cut-off values, the new-Vienna CATS score provided statistically significant stratification for VTE. Both RAMs proved to be effective in identifying patients at increased risk of mortality.
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Neoplasias , Tromboembolia Venosa , Humanos , Tromboembolia Venosa/diagnóstico , Tromboembolia Venosa/epidemiología , Tromboembolia Venosa/etiología , Estudios Prospectivos , Estudios Retrospectivos , Neoplasias/diagnóstico , Neoplasias/tratamiento farmacológico , Neoplasias/complicaciones , Factores de Riesgo , Medición de RiesgoRESUMEN
Alginate-gelatin hydrogels mimicking extracellular matrix (ECM) of soft tissues have been generated by static-dynamic double crosslinking, allowing fine control over the physical and chemical properties. Dynamic crosslinking provides self-healing and injectability attributes to the hydrogel and promotes cell migration and proliferation, while the static network improves stability. The static crosslinking was performed by enzymatic coupling of the tyrosine residues of gelatin with tyramine residues inserted in the alginate backbone, catalyzed by horseradish peroxidase (HRP). The dynamic crosslinking was obtained by functionalizing alginate with 3-aminophenylboronic acid which generates a reversible bond with the vicinal hydroxyl groups of the alginate chains. Varying the ratio of alginate and gelatin, hydrogels with different properties were obtained, and the most suitable for 3D soft tissue model development with a 2.5:1 alginate:gelatin molar ratio was selected. The selected hydrogel was characterized with a swelling test, rheology test, self-healing test and by cytotoxicity, and the formulation resulted in transparent, reproducible, varying biomaterial batch, with a fast gelation time and cell biocompatibility. It is able to modulate the loss of the inner structure stability for a longer time with respect to the formulation made with only covalent enzymatic crosslinking, and shows self-healing properties.
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Gelatina , Hidrogeles , Hidrogeles/química , Gelatina/química , Alginatos/química , Materiales Biocompatibles/químicaRESUMEN
Three-dimensional (3D) bioprinting allows the production of artificial 3D cellular microenvironments thanks to the controlled spatial deposition of bioinks. Proper bioink characterization is required to achieve the essential characteristics of printability and biocompatibility for 3D bioprinting. In this work, a protocol to standardize the experimental characterization of a new bioink is proposed. A functionalized hydrogel based on gelatin and chitosan was used. The protocol was divided into three steps: pre-printing, 3D bioprinting, and post-printing. For the pre-printing step, the hydrogel formulation and its repeatability were evaluated. For the 3D-bioprinting step, the hydrogel-printability performance was assessed through qualitative and quantitative tests. Finally, for the post-printing step, the hydrogel biocompatibility was investigated using UMR-106 cells. The hydrogel was suitable for printing grids with good resolution from 4 h after the cross-linker addition. To guarantee a constant printing pressure, it was necessary to set the extruder to 37 °C. Furthermore, the hydrogel was shown to be a valid biomaterial for the UMR-106 cells' growth. However, fragmentation of the constructs appeared after 14 days, probably due to the negative osteosarcoma-cell interference. The protocol that we describe here denotes a strong approach to bioink characterization to improve standardization for future biomaterial screening and development.
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The development of new advanced constructs resembling structural and functional properties of human organs and tissues requires a deep knowledge of the morphological and biochemical properties of the extracellular matrices (ECM), and the capacity to reproduce them. Manufacturing technologies like 3D printing and bioprinting represent valuable tools for this purpose. This review will describe how morphological and biochemical properties of ECM change in different tissues, organs, healthy and pathological states, and how ECM mimics with the required properties can be generated by 3D printing and bioprinting. The review describes and classifies the polymeric materials of natural and synthetic origin exploited to generate the hydrogels acting as "inks" in the 3D printing process, with particular emphasis on their functionalization allowing crosslinking and conjugation with signaling molecules to develop bio-responsive and bio-instructive ECM mimics.
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Bioimpresión , Hidrogeles , Humanos , Hidrogeles/química , Ingeniería de Tejidos , Matriz Extracelular/química , Impresión Tridimensional , Andamios del Tejido/químicaRESUMEN
In cancer microenvironment, aberrant glycosylation events of ECM proteins and cell surface receptors occur. We developed a protocol to generate 3D bioprinted models of colorectal cancer (CRC) crosslinking hyaluronic acid and gelatin functionalized with three signalling glycans characterized in CRC, 3'-Sialylgalactose, 6'-Sialylgalactose and 2'-Fucosylgalactose. The crosslinking, performed exploiting azide functionalized gelatin and hyaluronic acid and 4arm-PEG-dibenzocyclooctyne, resulted in biocompatible hydrogels that were 3D bioprinted with commercial CRC cells HT-29 and patient derived CRC tumoroids. The glycosylated hydrogels showed good 3D printability, biocompatibility and stability over the time. SEM and synchrotron radiation SAXS/WAXS analysis revealed the influence of glycosylation in the construct morphology, whereas MALDI-MS imaging showed that protein profiles of tumoroid cells vary with glycosylation, indicating that sialylation and fucosylation of ECM proteins induce diverse alterations to the proteome of the tumoroid and surrounding cells.