40 research outputs found
In Vitro Erythropoiesis at Different pO2 Induces Adaptations That Are Independent of Prior Systemic Exposure to Hypoxia
Hypoxia is associated with increased erythropoietin (EPO) release to drive erythropoiesis.
At high altitude, EPO levels first increase and then decrease, although erythropoiesis remains elevated
at a stable level. The roles of hypoxia and related EPO adjustments are not fully understood, which
has contributed to the formulation of the theory of neocytolysis. We aimed to evaluate the role
of oxygen exclusively on erythropoiesis, comparing in vitro erythroid differentiation performed
at atmospheric oxygen, a lower oxygen concentration (three percent oxygen) and with cultures of
erythroid precursors isolated from peripheral blood after a 19-day sojourn at high altitude (3450 m).
Results highlight an accelerated erythroid maturation at low oxygen and more concave morphology
of reticulocytes. No differences in deformability were observed in the formed reticulocytes in the
tested conditions. Moreover, hematopoietic stem and progenitor cells isolated from blood affected by
hypoxia at high altitude did not result in different erythroid development, suggesting no retention of a
high-altitude signature but rather an immediate adaptation to oxygen concentration. This adaptation
was observed during in vitro erythropoiesis at three percent oxygen by a significantly increased
glycolytic metabolic profile. These hypoxia-induced effects on in vitro erythropoiesis fail to provide
an intrinsic explanation of the concept of neocytolysis
In Vitro Erythropoiesis at Different pO2 Induces Adaptations That Are Independent of Prior Systemic Exposure to Hypoxia
Hypoxia is associated with increased erythropoietin (EPO) release to drive erythropoiesis. At high altitude, EPO levels first increase and then decrease, although erythropoiesis remains elevated at a stable level. The roles of hypoxia and related EPO adjustments are not fully understood, which has contributed to the formulation of the theory of neocytolysis. We aimed to evaluate the role of oxygen exclusively on erythropoiesis, comparing in vitro erythroid differentiation performed at atmospheric oxygen, a lower oxygen concentration (three percent oxygen) and with cultures of erythroid precursors isolated from peripheral blood after a 19-day sojourn at high altitude (3450 m). Results highlight an accelerated erythroid maturation at low oxygen and more concave morphology of reticulocytes. No differences in deformability were observed in the formed reticulocytes in the tested conditions. Moreover, hematopoietic stem and progenitor cells isolated from blood affected by hypoxia at high altitude did not result in different erythroid development, suggesting no retention of a high-altitude signature but rather an immediate adaptation to oxygen concentration. This adaptation was observed during in vitro erythropoiesis at three percent oxygen by a significantly increased glycolytic metabolic profile. These hypoxia-induced effects on in vitro erythropoiesis fail to provide an intrinsic explanation of the concept of neocytolysis
Glutaraldehyde – A Subtle Tool in the Investigation of Healthy and Pathologic Red Blood Cells
Glutaraldehyde is a well-known substance used in biomedical research to fix cells. Since hemolytic anemias are often associated with red blood cell shape changes deviating from the biconcave disk shape, conservation of these shapes for imaging in general and 3D-imaging in particular, like confocal microscopy, scanning electron microscopy or scanning probe microscopy is a common desire. Along with the fixation comes an increase in the stiffness of the cells. In the context of red blood cells this increased rigidity is often used to mimic malaria infected red blood cells because they are also stiffer than healthy red blood cells. However, the use of glutaraldehyde is associated with numerous pitfalls: (i) while the increase in rigidity by an application of increasing concentrations of glutaraldehyde is an analog process, the fixation is a rather digital event (all or none); (ii) addition of glutaraldehyde massively changes osmolality in a concentration dependent manner and hence cell shapes can be distorted; (iii) glutaraldehyde batches differ in their properties especially in the ratio of monomers and polymers; (iv) handling pitfalls, like inducing shear artifacts of red blood cell shapes or cell density changes that needs to be considered, e.g., when working with cells in flow; (v) staining glutaraldehyde treated red blood cells need different approaches compared to living cells, for instance, because glutaraldehyde itself induces a strong fluorescence. Within this paper we provide documentation about the subtle use of glutaraldehyde on healthy and pathologic red blood cells and how to deal with or circumvent pitfalls
Perspektiven der Sozialen Landwirtschaft unter besonderer Berücksichtigung der Entwicklungen in Italien
This volume presents the current scientific debate, innovative projects and approaches of Social Agriculture in Italy and in the German-speaking area. The work is aimed at professionals from social services, health and education, students of social sciences and agricultural economics, and those responsible for social policies, regional development, organic farming and eco-social transformation.; Diese Publikation stellt aktuelle wissenschaftliche Diskurse, innovative Projekte und Konzepte der Sozialen Landwirtschaft in Italien und im deutschsprachigen Raum vor. Sie richtet sich an Fachkräfte des Sozial,- Gesundheits- und Bildungswesens, Studierende des Sozialwesens und der Agrarwirtschaft, Verantwortliche der Sozialpolitik und Regionalentwicklung, der biologischen Landwirtschaft und der öko-sozialen Transformation. ; Questo volume presenta l’attuale dibattito scientifico, progetti innovativi e approcci dell’Agricoltura Sociale in Italia e nell’area germanofona. Il lavoro si rivolge a professionisti dei servizi sociali, della sanità e dell’istruzione, a studenti delle scienze sociali e di economia agraria e ai responsabili delle politiche sociali, dello sviluppo regionale, dell’agricoltura biologica e della trasformazione eco-sociale
Durvalumab plus gemcitabine and cisplatin in advanced biliary tract cancer: An early exploratory analysis of real-world data
Background: The TOPAZ-1 phase III trial reported a survival benefit with the anti-programmed death cell ligand 1 (anti-PD-L1) durvalumab in combination with gemcitabine and cisplatin in patients with advanced biliary tract cancer. The present study investigated the efficacy and safety of this new standard treatment in a real-world setting.Methods: The analysed population included patients with unresectable, locally advanced or metastatic adenocarcinoma of the biliary tract treated with durvalumab in combination with gemcitabine and cisplatin at 17 Italian centres. The primary endpoint of the study was progression-free survival (PFS), whereas secondary endpoints included overall survival (OS), overall response rate (ORR) and safety. Unadjusted and adjusted hazard ratios (HRs) by baseline characteristics were calculated using the Cox proportional hazards model.Results: From February 2022 to November 2022, 145 patients were enrolled. After a median follow-up of 8.5 months (95% CI: 7.9-13.6), the median PFS was 8.9 months (95% CI: 7.4-11.7). Median OS was 12.9 months (95% CI: 10.9-12.9). The investigator-assessed confirmed ORR was 34.5%, and the disease control rate was 87.6%. Any grade adverse events (AEs) occurred in 137 patients (94.5%). Grades 3-4 AEs occurred in 51 patients (35.2%). The rate of immune-mediated AEs (imAEs) was 22.7%. Grades 3-4 imAEs occurred in 2.1% of the patients. In univariate analysis, non-viral aetiology, ECOG PS >0 and NLR >= 3 correlated with shorter PFS.Conclusion: The results reported in this first real-world analysis mostly confirmed the results achieved in the TOPAZ-1 trial in terms of PFS, ORR and safety
Heterogeneity of red blood cells: causes and consequences
Mean values of hematological parameters are currently used in the clinical laboratory settings to characterize red blood cell properties. Those include red blood cell indices, osmotic fragility test, eosin 5-maleimide (EMA) test, and deformability assessment using ektacytometry to name a few. Diagnosis of hereditary red blood cell disorders is complemented by identification of mutations in distinct genes that are recognized "molecular causes of disease." The power of these measurements is clinically well-established. However, the evidence is growing that the available information is not enough to understand the determinants of severity of diseases and heterogeneity in manifestation of pathologies such as hereditary hemolytic anemias. This review focuses on an alternative approach to assess red blood cell properties based on heterogeneity of red blood cells and characterization of fractions of cells with similar properties such as density, hydration, membrane loss, redox state, Ca2+ levels, and morphology. Methodological approaches to detect variance of red blood cell properties will be presented. Causes of red blood cell heterogeneity include cell age, environmental stress as well as shear and metabolic stress, and multiple other factors. Heterogeneity of red blood cell properties is also promoted by pathological conditions that are not limited to the red blood cells disorders, but inflammatory state, metabolic diseases and cancer. Therapeutic interventions such as splenectomy and transfusion as well as drug administration also impact the variance in red blood cell properties. Based on the overview of the studies in this area, the possible applications of heterogeneity in red blood cell properties as prognostic and diagnostic marker commenting on the power and selectivity of such markers are discussed