113 research outputs found

    PSI-based methodology to land subsidence mechanism recognition

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    Abstract. A methodology based on Persistent Scatterer Interferometry (PSI) is proposed in order to disentangle the contribution of different processes that act at different spatio-temporal scales in land subsidence (i.e. vadose zone processes as swelling/shrinkage of clay soils, soil consolidation and fluid extraction). The methodology was applied in different Italian geological contexts characterized by natural and anthropic processes (i.e. a Prealpine valley and the Po Plain in northern Italy)

    A balanced formula of essential amino acids promotes brain mitochondrial biogenesis and protects neurons from ischemic insult

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    Mitochondrial dysfunction plays a key role in the aging process, and aging is a strong risk factor for neurodegenerative diseases or brain injury characterized by impairment of mitochondrial function. Among these, ischemic stroke is one of the leading causes of death and permanent disability worldwide. Pharmacological approaches for its prevention and therapy are limited. Although non-pharmacological interventions such as physical exercise, which promotes brain mitochondrial biogenesis, have been shown to exert preventive effects against ischemic stroke, regular feasibility is complex in older people, and nutraceutical strategies could be valuable alternatives. We show here that dietary supplementation with a balanced essential amino acid mixture (BCAAem) increased mitochondrial biogenesis and the endogenous antioxidant response in the hippocampus of middle-aged mice to an extent comparable to those elicited by treadmill exercise training, suggesting BCAAem as an effective exercise mimetic on brain mitochondrial health and disease prevention. In vitro BCAAem treatment directly exerted mitochondrial biogenic effects and induced antioxidant enzyme expression in primary mouse cortical neurons. Further, exposure to BCAAem protected cortical neurons from the ischemic damage induced by an in vitro model of cerebral ischemia (oxygen-glucose deprivation, OGD). BCAAem-mediated protection against OGD was abolished in the presence of rapamycin, Torin-1, or L-NAME, indicating the requirement of both mTOR and eNOS signaling pathways in the BCAAem effects. We propose BCAAem supplementation as an alternative to physical exercise to prevent brain mitochondrial derangements leading to neurodegeneration and as a nutraceutical intervention aiding recovery after cerebral ischemia in conjunction with conventional drugs

    Integrated strategies to prevent intradialytic hypotension: research protocol of the DialHypot study, a prospective randomised clinical trial in hypotension-prone haemodialysis patients

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    INTRODUCTION: In patients on maintenance haemodialysis (HD), intradialytic hypotension (IDH) is a clinical problem that nephrologists and dialysis nurses face daily in their clinical routine. Despite the technological advances in the field of HD, the incidence of hypotensive events occurring during a standard dialytic treatment is still very high. Frequently recurring hypotensive episodes during HD sessions expose patients not only to severe immediate complications but also to a higher mortality risk in the medium term. Various strategies aimed at preventing IDH are currently available, but there is lack of conclusive data on more integrated approaches combining different interventions. METHODS AND ANALYSIS: This is a prospective, randomised, open-label, crossover trial (each subject will be used as his/her own control) that will be performed in two distinct phases, each of which is divided into several subphases. In the first phase, 27 HD sessions for each patient will be used, and will be aimed at the validation of a new ultrafiltration (UF) profile, designed with an ascending/descending shape, and a standard dialysate sodium concentration. In the second phase, 33 HD sessions for each patient will be used and will be aimed at evaluating the combination of different UF and sodium profiling strategies through individualised dialysate sodium concentration. ETHICS AND DISSEMINATION: The trial protocol has been reviewed and approved by the local Institutional Ethics Committee (Comitato Etico AVEN, prot. 43391 22.10.19). The results of the trial will be presented at local and international conferences and submitted for publication to a peer-reviewed journal. TRIAL REGISTRATION NUMBER: ClinicalTrials.gov Registry (NCT03949088)

    Perinatal Parenting Stress, Anxiety, and Depression Outcomes in First-Time Mothers and Fathers: A 3- to 6-Months Postpartum Follow-Up Study

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    Objective: Although there is an established link between parenting stress, postnatal depression, and anxiety, no study has yet investigated this link in first-time parental couples. The specific aims of this study were 1) to investigate whether there were any differences between first-time fathers’ and mothers’ postnatal parenting stress, anxiety, and depression symptoms and to see their evolution between three and 6 months after their child’s birth; and 2) to explore how each parent’s parenting stress and anxiety levels and the anxiety levels and depressive symptoms of their partners contributed to parental postnatal depression. Method: The sample included 362 parents (181 couples; mothers’ MAge = 35.03, SD = 4.7; fathers’ MAge = 37.9, SD = 5.6) of healthy babies. At three (T1) and 6 months (T2) postpartum, both parents filled out, in a counterbalanced order, the Parenting Stress Index-Short Form, the Edinburgh Postnatal Depression Scale, and the State- Trait Anxiety Inventory. Results: The analyses showed that compared to fathers, mothers reported higher scores on postpartum anxiety, depression, and parenting stress. The scores for all measures for both mothers and fathers decreased from T1 to T2. However, a path analysis suggested that the persistence of both maternal and paternal postnatal depression was directly influenced by the parent’s own levels of anxiety and parenting stress and by the presence of depression in his/her partner. Discussion: This study highlights the relevant impact and effects of both maternal and paternal stress, anxiety, and depression symptoms during the transition to parenthood. Therefore, to provide efficacious, targeted, early interventions, perinatal screening should be directed at both parents

    Real-time imaging of polymersome nanoparticles in zebrafish embryos engrafted with melanoma cancer cells: Localization, toxicity and treatment analysis

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    BACKGROUND: The developing zebrafish is an emerging tool in nanomedicine, allowing non-invasive live imaging of the whole animal at higher resolution than is possible in the more commonly used mouse models. In addition, several transgenic fish lines are available endowed with selected cell types expressing fluorescent proteins; this allows nanoparticles to be visualized together with host cells. METHODS: Here, we introduce the zebrafish neural tube as a robust injection site for cancer cells, excellently suited for high resolution imaging. We use light and electron microscopy to evaluate cancer growth and to follow the fate of intravenously injected nanoparticles. FINDINGS: Fluorescently labelled mouse melanoma B16 cells, when injected into this structure proliferated rapidly and stimulated angiogenesis of new vessels. In addition, macrophages, but not neutrophils, selectively accumulated in the tumour region. When injected intravenously, nanoparticles made of Cy5-labelled poly(ethylene glycol)-block-poly(2-(diisopropyl amino) ethyl methacrylate) (PEG-PDPA) selectively accumulated in the neural tube cancer region and were seen in individual cancer cells and tumour associated macrophages. Moreover, when doxorubicin was released from PEG-PDPA, in a pH dependant manner, these nanoparticles could strongly reduce toxicity and improve the treatment outcome compared to the free drug in zebrafish xenotransplanted with mouse melanoma B16 or human derived melanoma cells. INTERPRETATION: The zebrafish has the potential of becoming an important intermediate step, before the mouse model, for testing nanomedicines against patient-derived cancer cells. FUNDING: We received funding from the Norwegian research council and the Norwegian cancer society

    Block length-dependent protein fouling on Poly(2-oxazoline)-based polymersomes: influence on macrophage association and circulation behavior

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    Polymersomes are vesicular structures self-assembled from amphiphilic block copolymers and are considered an alternative to liposomes for applications in drug delivery, immunotherapy, biosensing, and as nanoreactors and artificial organelles. However, the limited availability of systematic stability, protein fouling (protein corona formation), and blood circulation studies hampers their clinical translation. Poly(2-oxazoline)s (POx) are valuable antifouling hydrophilic polymers that can replace the current gold-standard, poly(ethylene glycol) (PEG), yet investigations of POx functionality on nanoparticles are relatively sparse. Herein, a systematic study is reported of the structural, dynamic and antifouling properties of polymersomes made of poly(2-methyl-2-oxazoline)-block-poly(dimethylsiloxane)-block-poly(2-methyl-2-oxazoline) (PMOXA-b-PDMS-b-PMOXA). The study relates in vitro antifouling performance of the polymersomes to atomistic molecular dynamics simulations of polymersome membrane hydration behavior. These observations support the experimentally demonstrated benefit of maximizing the length of PMOXA (degree of polymerization (DP) > 6) while keeping PDMS at a minimal length that still provides sufficient membrane stability (DP > 19). In vitro macrophage association and in vivo blood circulation evaluation of polymersomes in zebrafish embryos corroborate these findings. They further suggest that single copolymer presentation on polymersomes is outperformed by blends of varied copolymer lengths. This study helps to rationalize design rules for stable and low-fouling polymersomes for future medical applications

    The zebrafish embryo as an in vivo model for screening nanoparticle-formulated lipophilic anti-tuberculosis compounds.

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    With the increasing emergence of drug-resistant Mycobacterium tuberculosis strains, new and effective antibiotics against tuberculosis (TB) are urgently needed. However, the high frequency of poorly water-soluble compounds among hits in high-throughput drug screening (HTS) campaigns is a major obstacle in drug discovery. Moreover, in vivo testing using conventional animal TB models such as mice is time-consuming and costly, and represents a major bottleneck in lead compound discovery and development. Here, we report the use of the zebrafish embryo TB model, to evaluate the in vivo toxicity and efficacy of five poorly water-soluble nitronaphthofuran derivatives, which were recently identified to possess anti-tuberculosis activity in vitro. To aid solubilization compounds were formulated in biocompatible polymeric micelles (PM). Three of the five PM-formulated nitronaphthofuran derivatives showed low toxicity in vivo, significantly reduced bacterial burden and improved survival in infected zebrafish embryos. We propose the zebrafish embryo TB-model as a quick and sensitive tool for evaluating in vivo toxicity and efficacy of new anti-TB compounds during early stages of drug development. Thus, this model is well suited to pinpoint promising compounds for further development.Drug Delivery Technolog

    Modular synthesis of semiconducting graft co-polymers to achieve ‘clickable’ fluorescent nanoparticles with long circulation and specific cancer targeting

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    Semiconducting polymer nanoparticles (SPNs) are explored for applications in cancer theranostics because of their high absorption coefficients, photostability, and biocompatibility. However, SPNs are susceptible to aggregation and protein fouling in physiological conditions, which can be detrimental for in vivo applications. Here, a method for achieving colloidally stable and low-fouling SPNs is described by grafting poly(ethylene glycol) (PEG) onto the backbone of the fluorescent semiconducting polymer, poly(9,9â€Č-dioctylfluorene-5-fluoro-2,1,3-benzothiadiazole), in a simple one-step substitution reaction, postpolymerization. Further, by utilizing azide-functionalized PEG, anti-human epidermal growth factor receptor 2 (HER2) antibodies, antibody fragments, or affibodies are site-specifically “clicked” onto the SPN surface, which allows the functionalized SPNs to specifically target HER2-positive cancer cells. In vivo, the PEGylated SPNs are found to have excellent circulation efficiencies in zebrafish embryos for up to seven days postinjection. SPNs functionalized with affibodies are then shown to be able to target HER2 expressing cancer cells in a zebrafish xenograft model. The covalent PEGylated SPN system described herein shows great potential for cancer theranostics

    Π-Π interactions stabilize PeptoMicelle-based formulations of Pretomanid derivatives leading to promising therapy against tuberculosis in zebrafish and mouse models

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    Tuberculosis is the deadliest bacterial disease globally, threatening the lives of millions every year. New antibiotic therapies that can shorten the duration of treatment, improve cure rates, and impede the development of drug resistance are desperately needed. Here, we used polymeric micelles to encapsulate four second-generation derivatives of the antitubercular drug pretomanid that had previously displayed much better in vivo activity against Mycobacterium tuberculosis than pretomanid itself. Because these compounds were relatively hydrophobic and had limited bioavailability, we expected that their micellar formulations would overcome these limitations, reduce toxicities, and improve therapeutic outcomes. The polymeric micelles were based on polypept(o)ides (PeptoMicelles) and were stabilized in their hydrophobic core by π-π interactions, allowing the efficient encapsulation of aromatic pretomanid derivatives. The stability of these π-π-stabilized PeptoMicelles was demonstrated in water, blood plasma, and lung surfactant by fluorescence cross-correlation spectroscopy and was further supported by prolonged circulation times of several days in the vasculature of zebrafish larvae. The most efficacious PeptoMicelle formulation tested in the zebrafish larvae infection model almost completely eradicated the bacteria at non-toxic doses. This lead formulation was further assessed against Mycobacterium tuberculosis in the susceptible C3HeB/FeJ mouse model, which develops human-like necrotic granulomas. Following intravenous administration, the drug-loaded PeptoMicelles significantly reduced bacterial burden and inflammatory responses in the lungs and spleens of infected mice.Drug Delivery Technolog
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