Publications by authors named "Marco Stebel"

Primary hepatocytes are a commonly used tool for in vitro liver-related studies. However, the maintenance of these cells has always been a challenge due to the rapid loss of morphology, viability, and functionality in culture. A recent approach to long-term culture is the generation of three-dimensional (3D) organoids, an in vitro tool that can recapitulate tissues in a dish based on the marvelous ability of the liver to regenerate itself.

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An improved understanding of an ovary's structures is highly desirable to support advances in folliculogenesis knowledge and reproductive medicine, with particular attention to fertility preservation options for prepubertal girls with malignant tumors. Although currently the golden standard for structural analysis is provided by combining histological sections, staining, and visible 2D microscopic inspection, synchrotron radiation phase-contrast microtomography is becoming a new challenge for three-dimensional studies at micrometric resolution. To this aim, the proper use of contrast agents can improve the visualization of internal structures in ovary tissues, which normally present a low radiopacity.

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The swimming forces exerted by mammalian spermatozoa during the pathway to the ovary and during the interaction with the oocyte are thought to play a fundamental role in the fertilization of the egg. In particular, a process named capacitation is of key relevance for its success. Capacitation enables spermatozoa to undergo the acrosome reaction and to exhibit different motility called hyperactivation with a change in the sperm cell tail motion from symmetric to a more asymmetric beating, characterized by wider flagellar bending at lower frequencies.

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One of the organ-specific functions of the liver is the excretion of bilirubin into the bile. Membrane transport of bilirubin from the blood to the liver is not only an orphan function, because there is no link to the protein/gene units that perform this function, but also a poorly characterised function. The aim of this study was to investigate the pharmacology of bilirubin uptake in the liver of the female Wistar rat to improve basic knowledge in this neglected area of liver physiology.

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Postovulatory aging is a process occurring in the mature (MII) oocyte leading the unfertilized ones to apoptosis. The optimal time window of fertility for different mammalian species after oocytes maturation depends on its timeliness: the higher the time elapsed from the accomplishment of the MII stage, the lower are the chances of fertilization and of development of a viable embryo. In the in vitro fertilization, the selection of competent oocytes for intracytoplasmic sperm injection (ICSI) is mostly made by the visual inspection of the MII oocyte morphology, which does not allow to determine the oocyte postovulatory age.

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A new, bifunctional recombinant protein was expressed as the fusion product of human elastin-like polypeptide (HELP) and the bilirubin-binding protein UnaG. The engineered product displays both the HELP-specific property of forming a functional hydrogel matrix and the UnaG-specific capacity of emitting green fluorescence upon ligand binding. The new fusion protein has been proven to be effective at detecting bilirubin in complex environments with high background noise.

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Gadolinium deposition in tissue is linked to nephrogenic systemic fibrosis (NSF): a rare disorder occurring in patients with severe chronic kidney disease and associated with administration of Gd-based contrast agents (GBCAs) for Magnetic Resonance Imaging (MRI). It is suggested that the GBCAs prolonged permanence in blood in these patients may result in a Gd precipitation in peripheral or central organs, where it initiates a fibrotic process. In this study we investigated new sites of retention/precipitation of Gd in a mouse model of renal disease (5/6 nephrectomy) receiving two doses (closely after each other) of a linear GBCA.

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To investigate how long relocation modified hair cortisol concentrations in New Zealand white rabbits, 19 rabbits were subjected to a change in their breeding facility at the beginning of the trial and then were kept under stable environmental conditions. Hair samples were collected at the time of arrival to the nonhuman animal facility and at 40-day intervals from the same skin area for up to 440 days after the animals' arrival to the facility. A period effect on the hair cortisol concentration was found (p < .

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Several complex mechanisms contribute to the maintenance of the intricate ramified morphology of glomerular podocytes and to interactions with neighboring cells and the underlying basement membrane. Recently, components of small molecule transporter families have been found in the podocyte membrane, but expression and function of membrane transporters in podocytes is largely unexplored. To investigate this complex field of investigation, we used two molecules which are known substrates of membrane transporters, namely Penicillin G and Puromycin Aminonucleoside (PA).

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Purpose: We aimed to describe the morphological changes in the thoracic cage and spinal column induced in New Zealand White (NZW) prepubertal rabbits subjected to dorsal arthrodesis and observed at skeletal maturity by computed tomography (CT) scans. This was done to evaluate the plasticity of the thoracic cage of rabbits with non-deformed spine, by highlighting its modifications after spinal arthrodesis. Emogas data analysis, echocardiographic assessment and cardio-pulmonary measurements completed the evaluation.

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Unlabelled: The ability to perform cell tracking using x-ray computed tomography combined with gold nanoparticles has been demonstrated recently on ex vivo samples using different malignant and nonmalignant cell lines. Here we proved the concept of the method for in vivo assessment in a small-animal model of malignant brain tumors. The limitations of the method due to radiation dose constraints were investigated using Monte Carlo simulations.

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Objectives: The mechanisms underlying the increased cardiovascular risk after menopause are poorly understood. Estrogens modulate the cardiac renin-angiotensin system (RAS) and influence cardiac adaptation to afterload. To investigate whether the loss of the natural inhibition of the RAS by estrogen may be linked to an increase of cardiac apoptosis, we studied 17β-estradiol (E2) and/or angiotensin-converting enzyme (ACE) inhibitor treatment effects on cardiomyocyte survival in ovariectomized spontaneously hypertensive rats (SHRs).

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Background & Aims: Involvement of insulin in diabetes-associated liver triglyceride deposition and its potential pathways remain incompletely defined. SIRT1 may negatively modulate lipogenesis and liver triglyceride accumulation, involving AMP-activated protein kinase (AMPK) activation. In streptozotocin-diabetic rats, we hypothesized that insulin negatively modulates liver SIRT1 and activates AMPK-inhibited lipogenic mediators leading to triglyceride accumulation.

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Aging is characterized by activation of inducible over endothelial nitric oxide synthase (iNOS and eNOS), impaired antioxidant activity and increased oxidative stress, which reduces nitric oxide bioavailability and causes endothelial dysfunction. Caloric restriction (CR) blunts oxidative stress. We investigated whether CR impacts endothelial dysfunction in aging and the underlying mechanisms.

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The design of new photosensitizers with enhanced phototoxicity and pharmacokinetic properties remains a central challenge for cancer photodynamic therapy (PDT). In this study, Pheophorbide a (Pba) has been pegylated to methoxypolyethylene glycol (mPE G-Pba) to produce a soluble photosensitizer that exhibits a higher tissue distribution than free Pba. In vitro studies have shown that mPE G-Pba promotes a fairly strong photosensitizing effect in cancer cells, as previously observed for the unpegylated molecule.

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Background: Celiac disease (CD) is an autoimmune gastrointestinal disorder characterized by the presence of anti-transglutaminase 2 (TG2) and anti-gliadin antibodies. Amongst the neurological dysfunctions associated with CD, ataxia represents the most common one.

Methods: We analyzed by immunohistochemistry, the anti-neural reactivity of the serum from 20 CD patients.

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Background: Several studies have shown that severe spinal deformity and early arthrodesis can adversely affect the development of the spine and thorax by changing their shape and reducing their normal function. This article analyzes the consequences of posterior fusion on the growth of spine, thorax and neural elements in New Zealand white rabbits and compares with similar human data.

Materials And Methods: The first section of the article analyzes the consequences of T1-T6 dorsal arthrodesis on the growth of the spine, sternum, thorax volume and neural elements in 12 prepubertal female New Zealand white rabbits, through a study of CT scans and histology specimens.

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Objective: Ghrelin administration can induce fat weight gain and hyperglycemia (potentially through ghrelin-induced hepatic glucose production), but plasma ghrelin is positively associated with whole-body insulin sensitivity (mainly reflecting muscle insulin action) being increased in lean individuals or after diet-induced weight loss and reduced in obesity or after diet-induced weight gain. To investigate potential mechanisms, we measured in vivo effects of sustained ghrelin administration at a non-orexigenic dose on skeletal muscle and liver insulin signaling at the AKT level and adipokine expression changes.

Research Methods And Procedures: Young-adult male rats received 4-day, twice daily subcutaneous ghrelin (200 mug/injection) or saline.

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Celiac disease is an autoimmune illness characterized by intestinal mucosal injury and malabsorption precipitated by dietary exposure to gluten of some cereals. The immune response is based on both cellular and humoral components, although the former seem to be more important in the pathogenesis. The autoantibody response is directed at the enzyme tissue transglutaminase, tTG or TG2, which possibly play a role in the onset of the disease.

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Gluten sensitivity is an autoimmune disease that usually causes intestinal atrophy resulting in a malabsorption syndrome known as celiac disease. However, gluten sensitivity may involve several organs and is often associated with extraintestinal manifestations. Typically, patients with celiac disease have circulating anti-tissue transglutaminase and anti-gliadin antibodies.

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Background: Phage display antibody libraries have been made from the lymphocytes of patients suffering from autoimmune diseases in which the antibodies are known to play a role in the pathogenesis or are important for the diagnosis of the disease. In the case of Celiac Disease, the immune response is directed against the autoantigen tissue transglutaminase. However, despite numerous studies, the role of these antibodies in the pathogenesis of this disease has not been elucidated.

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Study Design: Dorsal arthrodesis of thoracic spine in a prepubertal New Zealand White rabbit model.

Objective: Evaluating the consequences of dorsal arthrodesis on the growth of the spine, sternum, and thorax in prepubertal rabbits, through the study of CT scans.

Summary Of Background Data: Vertebral arthrodesis in the treatment of progressive idiopathic scoliosis in prepubertal patients is not ideal, but is still a choice in treating major deformities of the spine.

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Experimental evidences indicate that the TNF family member TNF-related apoptosis inducing ligand (TRAIL) might be involved in modulating osteoclastic differentiation. The ability of recombinant soluble TRAIL to affect bone density in vivo was evaluated by using 4-week-old mice subcutaneously (s.c.

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Objective: To gain insight into the regulation of cardiac apoptosis we studied the dose-response and time-course effects of angiotensin II (Ang II) infusion on ventricular cardiomyocyte apoptosis and on the expression of Bax and Bcl-2 genes and proteins.

Study Design And Methods: In the dose-response study, Ang II was infused subcutaneously at doses of 100, 200, 400, 800 and 1200 ng/kg per min for 14 days. In the time-course study, rats infused with Ang II at doses of 200 and 400 ng/kg per min were followed for 7 and 14 days.

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Antiatherogenic effects of nitric oxide (NO) are mediated by activation of soluble guanylate cyclase (sGC) and are impaired by diabetes in animals and humans. We investigated whether uncontrolled diabetes and insulin therapy effect expression and function of the main enzymes of the endothelial nitric oxide (eNOS)-sGC signaling pathway in vivo. Expression and function of eNOS, sGC and protein kinase G (PKG) were studied by Western blot analysis and vasorelaxation to NO-donor in thoracic aortas from control (CON) and streptozotocin (SZT)-induced diabetic rats during uncontrolled diabetes (DM) and insulin treatment (INS) for 8 weeks.

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