72 research outputs found
The Rabbit Shunt Model of Subarachnoid Haemorrhage
Aneurysmal subarachnoid haemorrhage (SAH) is a disease with devastating complications that leads to stroke, permanent neurological deficits and death. Clinical and ex-perimental work has demonstrated the importance of the contribution of delayed cerebral vasospasm (DCVS) indepen-dent early events to mortality, morbidity and functional out-come after SAH. In order to elucidate processes involved in early brain injury (EBI), animal models that reflect acute events of aneurysmal bleeding, such as increase in intracranial pressure (ICP) and decrease in cerebral perfusion pressure, are needed. In the presented arterial shunt model, bleeding is initially driven by the pressure gradient between mean arterial blood pressure and ICP. SAH dynamics (flow rate, volume and duration) depend on physiological reactions and local anatomical intrathecal (cistern) conditions. During SAH, ICP reaches a plateau close to diastolic arterial blood pressure and the blood flow stops. Historical background, anaesthesia, perioperative care and monitoring, SAH induction, technical considerations and advantages and limitations of the rabbit blood shunt SAH model are discussed in detail. Awareness of technical details, physiological characteristics and appropriate monitoring methods guarantees successful implementation of the rabbit blood shunt model and allows the study of both EBI and DCVS after SAH
The Rabbit Shunt Model of Subarachnoid Haemorrhage
Aneurysmal subarachnoid haemorrhage (SAH) is a disease with devastating complications that leads to stroke, permanent neurological deficits and death. Clinical and ex-perimental work has demonstrated the importance of the contribution of delayed cerebral vasospasm (DCVS) indepen-dent early events to mortality, morbidity and functional out-come after SAH. In order to elucidate processes involved in early brain injury (EBI), animal models that reflect acute events of aneurysmal bleeding, such as increase in intracranial pressure (ICP) and decrease in cerebral perfusion pressure, are needed. In the presented arterial shunt model, bleeding is initially driven by the pressure gradient between mean arterial blood pressure and ICP. SAH dynamics (flow rate, volume and duration) depend on physiological reactions and local anatomical intrathecal (cistern) conditions. During SAH, ICP reaches a plateau close to diastolic arterial blood pressure and the blood flow stops. Historical background, anaesthesia, perioperative care and monitoring, SAH induction, technical considerations and advantages and limitations of the rabbit blood shunt SAH model are discussed in detail. Awareness of technical details, physiological characteristics and appropriate monitoring methods guarantees successful implementation of the rabbit blood shunt model and allows the study of both EBI and DCVS after SAH
Domain-specific regulation of cerebellar morphogenesis by Zfp423 / ZNF423, a gene implicated in Joubert syndrome and cerebellar vermis hypoplasia
The Zfp423 gene encodes a 30-Zn-finger transcription factor that acts as a scaffold for the assembly of complex transcriptional and cellular machineries regulating neural development. While null Zfp423 mutants feature a sharp decrease in the total number of cerebellar Purkinje cells (PCs), the underlying mechanisms remain unclear. Mutations of the human homolog ZNF423 have been identified in patients carrying cerebellar vermis hypoplasia (CVH) or Joubert Syndrome (JS), associated with other signs of classical ciliopathy outside the central nervous system. To further characterize the role of ZFP423 in cerebellar neurogenesis, we have performed morphological, cellular and molecular studies on two mutant mouse lines carrying allelic in-frame deletions of Zfp423. While both lines exhibit cerebellar hypoplasia, considerable differences are observed between the two mutants, with respect to neural progenitor differentiation, cell survival and morphogenesis. The results of this in vivo and in vitro structure-function analysis point to domain- and context-specific roles played by ZFP423 in different aspects of cerebellar development, and contribute to our understanding of its role as a disease / modifier gene in JS, CVH and other ciliopathies
Zinc-finger and helix-loop-helix transcription factors regulate Purkinje neuron neurogenesis and cerebellar corticogenesis
Many regulatory genes have been pinpointed as orchestrators of cerebellar development, from the onset of neurogenesis to the patterning of the adult cerebellar cortex, with a special reference to the development of cerebellar Purkinje cells (PCs). PCs provide the sole output from cerebellar cortical circuits, where each PC integrates myriads of presynaptic inputs, both inhibitory and excitatory. In the murine cerebellar primordium PCs are generated from a pool of ventricular zone progenitors facing the fourth ventricle between embryonic day (E) 10.5 and 13.5. This progenitor pool expands in the ventricular zone (VZ) through symmetric cell division until E10.5, when a gradual switch to asymmetric cell division occurs, regulated by Notch1 (Lutolf et al., 2002) and its interactor (Masserdotti et al., 2010), the Zn-finger TF Zfp423 (Alcaraz et al., 2006; Warming et al., 2006; Croci et al., submitted). Zfp423 was recently implicated in Joubert syndrome and cerebellar vermis hypoplasia (Chaki et al., 2012). Allelic mutations of Zfp423 produce distinct alterations in PC development (Croci et al., submitted). PCs arise from a pool of progenitors positive for the basic-helix-loop-helix transcription factors (TFs) neurogenin (Ngn) 1 and 2 (Zordan et al., 2008; Lundell et al., 2009). Ngn2 regulates cell cycle progression and dendritic arbor generation in PC precursors (Florio et al., 2012). PCs also express HLH transcription factors of the Olf/EBF family. In Ebf2 -/- mutants, PC migration and survival are affected (Croci et al., 2006). Neonatal PC death is due to local downregulation of Igf1 gene expression (Croci et al., 2011). Finally, EBF2 regulates cortical patterning in the adult cerebellum, regulating its subdivision into alternate parasagittal stripes of distinct PC subtypes. Indeed, EBF2 is required to repress the zebrin II+ phenotype in postnatal PCs (Croci et al., 2006; Chung et al., 2008)
Aiding the conservation of two wooden Buddhist sculptures with 3D imaging and spectroscopic techniques
The conservation of Buddhist sculptures that were transferred to Europe at some point during their lifetime raises numerous questions: while these objects historically served a religious, devotional purpose, many of them currently belong to museums or private collections, where they are detached from their original context and often adapted to western taste.
A scientific study was carried out to address questions from Museo d'Arte Orientale of Turin curators in terms of whether these artifacts might be forgeries or replicas, and how they may have transformed over time. Several analytical techniques were used for materials identification and to study the production technique, ultimately aiming to discriminate the original materials from those added within later interventions
Complex interplay between neutral and adaptive evolution shaped differential genomic background and disease susceptibility along the Italian peninsula
The Italian peninsula has long represented a natural hub for human migrations across the Mediterranean area, being involved in several prehistoric and historical population movements. Coupled with a patchy environmental landscape entailing different ecological/cultural selective pressures, this might have produced peculiar patterns of population structure and local adaptations responsible for heterogeneous genomic background of present-day Italians. To disentangle this complex scenario, genome-wide data from 780 Italian individuals were generated and set into the context of European/Mediterranean genomic diversity by comparison with genotypes from 50 populations. To maximize possibility of pinpointing functional genomic regions that have played adaptive roles during Italian natural history, our survey included also ∼250,000 exomic markers and ∼20,000 coding/regulatory variants with well-established clinical relevance. This enabled fine-grained dissection of Italian population structure through the identification of clusters of genetically homogeneous provinces and of genomic regions underlying their local adaptations. Description of such patterns disclosed crucial implications for understanding differential susceptibility to some inflammatory/autoimmune disorders, coronary artery disease and type 2 diabetes of diverse Italian subpopulations, suggesting the evolutionary causes that made some of them particularly exposed to the metabolic and immune challenges imposed by dietary and lifestyle shifts that involved western societies in the last centuries
The Recovery Orientation of a Farm Community for Severe Autism — Data from the DREEM-IT (Developing Recovery Enhancing Environment Measures — Italian Version)
Recent years have witnessed an increasing interest in the concept of ‘recovery’ in the field of mental health and psychiatry.
Autism is a neurodevelopmental disorder characterized by qualitative impairments in social interaction and communication skill, along with a restricted, repetitive, and stereotyped pattern of behavior and interests. The diagnosis is lifelong and can be a major impediment to independent living. It has been previously demonstrated that organized and structured forms of intervention, starting from early childhood and developing during all the different life stages, may improve outcome and quality of life in patients with autism.
It is therefore conceivable that diverse forms of recovery (e.g. optimal level of motivation, skills, social involvement) may be possible in autism.
There are no fully developed tools with which to evaluate the recovery orientation of a service, but the National Institute for Mental Health in England (NIMHE) has identified the Developing Recovery Enhancing Environments Measure (DREEM) as the most promising of an emerging group of recovery sensitive measures.
This study explores the use of DREEM, as a tool to evaluate the effectiveness of recovery-based care in an Italian farm community center specifically designed for adult patients with autism and intellectual disability
Abiotic Parameters and Pedogenesis as Controlling Factors for Soil C and N Cycling Along an Elevational Gradient in a Subalpine Larch Forest (NW Italy)
Mountain regions are vulnerable to climate change but information about the climate sensitivity of seasonally snow-covered, subalpine ecosystems is still lacking. We investigated the impact of climatic conditions and pedogenesis on the C and N cycling along an elevation gradient under a Larch forest in the northwest (NW) Italian Alps. The environmental gradient that occurs over short distances makes elevation a good proxy for understanding the response of forest soils and nutrient cycling to different climatic conditions. Subalpine forests are located in a sensitive elevation range—the prospected changes in winter precipitation (i.e., shift of snowfalls to higher altitude, reduction of snow cover duration, etc.) could determine strong effects on soil nitrogen and carbon cycling. The work was performed in the western Italian Alps (Long-Term Ecological Research- LTER site Mont Mars, Fontainemore, Aosta Valley Region). Three sites, characterized by similar bedrock lithology and predominance of Larix decidua Mill., were selected along an elevation gradient (1550–1900 m above sea level-a.s.l.). To investigate the effects on soil properties and soil solution C and N forms of changing abiotic factors (e.g., snow cover duration, number of soil freeze/thaw cycles, intensity and duration of soil freezing, etc.) along the elevation gradient, soil profiles were opened in each site and topsoils and soil solutions were periodically collected from 2015 to 2016. The results indicated that the coldest and highest soil (well-developed Podzol) showed the highest content of extractable C and N forms (N-NH4+, DON, DOC, Cmicr) compared to lower-elevation Cambisols. The soil solution C and N forms (except N-NO3−) did not show significant differences among the sites. Independently from elevation, the duration of soil freezing, soil volumetric water content, and snow cover duration (in order of importance) were the main abiotic factors driving soil C and N forms, revealing how little changes in these parameters could considerably influence C and N cycling under this subalpine forest stand
An explainable model of host genetic interactions linked to COVID-19 severity
We employed a multifaceted computational strategy to identify the genetic factors contributing to increased risk of severe COVID-19 infection from a Whole Exome Sequencing (WES) dataset of a cohort of 2000 Italian patients. We coupled a stratified k-fold screening, to rank variants more associated with severity, with the training of multiple supervised classifiers, to predict severity based on screened features. Feature importance analysis from tree-based models allowed us to identify 16 variants with the highest support which, together with age and gender covariates, were found to be most predictive of COVID-19 severity. When tested on a follow-up cohort, our ensemble of models predicted severity with high accuracy (ACC = 81.88%; AUCROC = 96%; MCC = 61.55%). Our model recapitulated a vast literature of emerging molecular mechanisms and genetic factors linked to COVID-19 response and extends previous landmark Genome-Wide Association Studies (GWAS). It revealed a network of interplaying genetic signatures converging on established immune system and inflammatory processes linked to viral infection response. It also identified additional processes cross-talking with immune pathways, such as GPCR signaling, which might offer additional opportunities for therapeutic intervention and patient stratification. Publicly available PheWAS datasets revealed that several variants were significantly associated with phenotypic traits such as "Respiratory or thoracic disease", supporting their link with COVID-19 severity outcome.A multifaceted computational strategy identifies 16 genetic variants contributing to increased risk of severe COVID-19 infection from a Whole Exome Sequencing dataset of a cohort of Italian patients
Carriers of ADAMTS13 Rare Variants Are at High Risk of Life-Threatening COVID-19
Thrombosis of small and large vessels is reported as a key player in COVID-19 severity. However, host genetic determinants of this susceptibility are still unclear. Congenital Thrombotic Thrombocytopenic Purpura is a severe autosomal recessive disorder characterized by uncleaved ultra-large vWF and thrombotic microangiopathy, frequently triggered by infections. Carriers are reported to be asymptomatic. Exome analysis of about 3000 SARS-CoV-2 infected subjects of different severities, belonging to the GEN-COVID cohort, revealed the specific role of vWF cleaving enzyme ADAMTS13 (A disintegrin-like and metalloprotease with thrombospondin type 1 motif, 13). We report here that ultra-rare variants in a heterozygous state lead to a rare form of COVID-19 characterized by hyper-inflammation signs, which segregates in families as an autosomal dominant disorder conditioned by SARS-CoV-2 infection, sex, and age. This has clinical relevance due to the availability of drugs such as Caplacizumab, which inhibits vWF-platelet interaction, and Crizanlizumab, which, by inhibiting P-selectin binding to its ligands, prevents leukocyte recruitment and platelet aggregation at the site of vascular damage
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