New York, NY, United States
New York, NY, United States

Rimed snow refers to snowflakes that are partially or completely coated in tiny frozen water droplets called 'rime'. Rime forms on a snowflake when it passes through a super-cooled cloud. Snowflakes that are heavily rimed typically produce very heavy and wet snow, with snow to liquid ratios in the 5-1 to 9-1 range.Rimed snow has been found to provide greater initial stability for a snow layer. However, it also allows thicker, and therefore less stable, snow layers to build up. It could be argued that these cancel each other out.There has been research into the effect of rimed snow on avalanches. Wikipedia.

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Di Maio R.,University of Pittsburgh | Di Maio R.,Rimed | Mastroberardino P.G.,University of Pittsburgh | Mastroberardino P.G.,Erasmus University Rotterdam | And 3 more authors.
Neurobiology of Disease | Year: 2011

The molecular basis for epileptogenesis remains poorly defined, but repeated or prolonged seizures can cause altered hippocampal N-methyl d-aspartate receptor (NMDAR) stoichiometry, loss of hippocampal neurons, and aberrant mossy fiber sprouting. Using the muscarinic receptor 1 (m1R) agonist, pilocarpine (PILO), in hippocampal cell cultures we explored the early sequence of molecular events that occur within 24 h of the initial insult and result in altered neuronal function during epileptogenesis. Our findings show that PILO-induced, m1R-mediated, inositol 1,4,5-trisphosphate (IP3) synthesis constitutes an early, crucial biochemical event required for NMDAR hyperactivation and subsequent NADPH oxidase (NOX) activation and NMDAR-independent ERK1/2 phoshorylation. Together, but not separately, NOX activation and ERK1/2 phosphorylation induce alterations in NMDAR stoichiometry through the upregulation of NR1 and NR2B subunits. Lastly, we demonstrated that PILO-mediated oxidative stress alters NMDAR function through the redox modulation of cysteine residues. The in vitro results related to thiol oxidation, NOX activation, ERK1/2 phosphorylation and NMDAR upregulation were confirmed in vivo, 24 h after treatment of adult rats with PILO. These results obtained in PILO-treated primary hippocampal neurons - and confirmed in vivo at the same time-point after PILO - provide a better understanding of the early cellular responses during epileptogenesis and identify potential therapeutic targets to prevent development of chronic epilepsy. © 2011 Elsevier Inc.

Bayer E.A.,University of Pittsburgh | Bayer E.A.,McGowan Institute for Regenerative Medicine | Gottardi R.,University of Pittsburgh | Gottardi R.,McGowan Institute for Regenerative Medicine | And 5 more authors.
Journal of Controlled Release | Year: 2015

Bone regeneration is a complex process, that in vivo, requires the highly coordinated presentation of biochemical cues to promote the various stages of angiogenesis and osteogenesis. Taking inspiration from the natural healing process, a wide variety of growth factors are currently being released within next generation tissue engineered scaffolds (in a variety of ways) in order to heal non-union fractures and bone defects. This review will focus on the delivery of multiple growth factors to the bone regeneration niche, specifically 1) dual growth factor delivery signaling and crosstalk, 2) the importance of growth factor timing and temporal separation, and 3) the engineering of delivery systems that allow for temporal control over presentation of soluble growth factors. Alternative methods for growth factor presentation, including the use of gene therapy and platelet-rich plasma scaffolds, are also discussed. © 2015 Elsevier B.V. All rights reserved.

Di Maio R.,University of Pittsburgh | Di Maio R.,Rimed | Cannon J.R.,Purdue University | Timothy Greenamyre J.,University of Pittsburgh
Neurobiology of Disease | Year: 2015

Repeated seizures are often associated with development of refractory chronic epilepsy, the most common form of which is temporal lobe epilepsy. G-protein-coupled cannabinoid receptors (CB1 and CB2 receptors) regulate neuronal excitability and have been shown to mediate acute anticonvulsant effects of cannabinoids in animal models. However, the potential of cannabinoids to prevent chronic neuronal damage and development of epilepsy remains unexplored. We hypothesized that treatment with a CB receptor agonist after an episode of status epilepticus - but before development of spontaneous recurrent seizures - might prevent the development of functional changes that lead to chronic epilepsy. Using the rat pilocarpine model, a therapeutic approach was simulated by administering the CB agonist, WIN 55,212-2 after an episode of status epilepticus. Epileptic behavior was monitored during development of spontaneous recurrent seizures for up to 6months. Histology, neurochemistry, redox status and NMDA receptor subunit expression were assessed at 6months after pilocarpine-induced seizures. Sub-acute treatment with WIN 55,212-2 (for 15days starting 24h after PILO injection) dramatically attenuated the severity, duration and frequency of spontaneous recurrent seizures. Further, in contrast to vehicle-treated animals, hippocampi from WIN 55,212-2-treated animals showed: normal thiol redox state, normal NR2A and NR2B subunit expression, preservation of GABAergic neurons and prevention of abnormal proliferation of GABAergic progenitors. This study shows for the first time that, after a known inciting event, treatment with a compound targeting CB receptors has the potential to prevent the epileptogenic events that result in chronic epileptic damage. © 2014 Published by Elsevier Inc.

Di Giovanni G.,University of Malta | Di Giovanni G.,University of Cardiff | Pessia M.,University of Perugia | Di Maio R.,University of Pittsburgh | Di Maio R.,Rimed
CNS and Neurological Disorders - Drug Targets | Year: 2012

Oxidant molecules generated during neuronal metabolism appear to play a significant role in the processes of aging and neurodegeneration. Increasing experimental evidence suggests the noteworthy relevance of the intracellular reduction-oxidation (redox) balance for the dopaminergic (DA-ergic) neurons of the substantia nigra pars compacta. These cells possess a distinct physiology intrinsically associated with elevated reactive oxygen species production, conferring on them a high vulnerability to free radical damage, one of the major causes of selective DA-ergic neuron dysfunction and degeneration related to neurological disorders such as Parkinson's disease. Tyrosine hydroxylase (tyrosine 3-monooxygenase; E.C.; TH) activity represents the rate-limiting biochemical event in DA synthesis. TH activity, metabolism and expression are finely tuned by several regulatory systems in order to maintain a crucial physiological condition in which DA synthesis is closely coupled to its secretion. Alterations of these regulatory systems of TH functions have indeed been thought to be key events in the DA-ergic degeneration. TH has seven cysteine residues presenting thiols. Depending on the oxido-reductive (redox) status of the cellular environment, thiols exist either in the reduced form of free thiols or oxidized to disulfides. The formation of disulfides in proteins exerts critical regulatory functions both in physiological and in pathological conditions when oxidative stress is sustained. Several reports have recently shown that redox state changes of thiol residues, as consequence of an oxidative injury, can directly or indirectly affect the TH activity, metabolism and expression. The major focus of this review, therefore, is to report recent evidence on the redox modulation of TH activity and expression, and to provide an overview of a cellular phenomenon that might represent a target for new therapeutic strategies against the DA-ergic neurodegenerative disorders. © 2012 Bentham Science Publishers.

Farrell T.C.,University of Pittsburgh | Cario C.L.,University of Pittsburgh | Milanese C.,University of Pittsburgh | Milanese C.,Rimed | And 5 more authors.
Neurobiology of Disease | Year: 2011

Zebrafish models of human neuropsychiatric diseases offer opportunities to identify novel therapeutic targets and treatments through phenotype-based genetic or chemical modifier screens. In order to develop an assay to detect rescue of zebrafish models of Parkinsonism, we characterized spontaneous zebrafish larval motor behavior from 3 to 9days post fertilization in a microtiter plate format suitable for screening, and clarified the role of dopaminergic signaling in its regulation. The proportion of time that larvae spent moving increased progressively between 3 and 9dpf, whereas their active velocity decreased between 5 and 6dpf as sporadic burst movements gave way to a more mature beat-and-glide pattern. Spontaneous movement varied between larvae and during the course of recordings as a result of intrinsic larval factors including genetic background. Variability decreased with age, such that small differences between groups of larvae exposed to different experimental conditions could be detected robustly by 6 to 7dpf. Suppression of endogenous dopaminergic signaling by exposure to MPP +, haloperidol or chlorpromazine reduced mean velocity by decreasing the frequency with which spontaneous movements were initiated, but did not alter active velocity. The variability of mean velocity assays could be reduced by analyzing groups of larvae for each data point, yielding acceptable screening window coefficients; the sample size required in each group was determined by the magnitude of the motor phenotype in different models. For chlorpromazine exposure, samples of four larvae allowed robust separation of treated and untreated data points (Z=0.42), whereas the milder impairment provoked by MPP + necessitated groups of eight larvae in order to provide a useful discovery assay (Z=0.13). Quantification of spontaneous larval movement offers a simple method to determine functional integrity of motor systems, and may be a useful tool to isolate novel molecular modulators of Parkinsonism phenotypes. © 2011.

Pasta S.,Rimed | Pasta S.,University of Pittsburgh | Pasta S.,McGowan Institute for Regenerative Medicine | Phillippi J.A.,McGowan Institute for Regenerative Medicine | And 5 more authors.
Journal of Thoracic and Cardiovascular Surgery | Year: 2012

Objectives: The acute dissection of an ascending thoracic aortic aneurysm (ATAA) represents a devastating separation of elastic layers occurring when the hemodynamic loads on the diseased wall exceed the adhesive strength between layers. At present, the mechanics underlying aortic dissection are largely unclear, and the biomechanical delamination properties of the aneurysmal aorta are not defined. Individuals with bicuspid aortic valve (BAV) are particularly predisposed to ascending aortic aneurysm formation, with a marked risk of aortic dissection. The purpose of this study was to evaluate and compare the dissection properties of nonaneurysmal and aneurysmal human ascending thoracic aorta from patients with BAV morphology or normal tricuspid aortic valve (TAV) morphology using biomechanical delamination testing. Methods: The influence on the delamination strength (S d) of the aorta associated with BAV was compared with that in patients with TAV. After complete delamination of ATAA tissue samples, tensile tests were performed on each delaminated half for comparison of their tensile strengths. Results: The results showed that the aneurysmal aortas with BAV and TAV have lower S d than nonaneurysmal aortas and that ATAA with BAV has a lower S d than that with TAV. We have found a significant difference in S d between longitudinal and circumferential directions of the nondiseased aorta, suggesting anisotropic dissection properties. Conclusions: The tensile testing results suggest that the weaker intimal half of the aortic wall might fail before the outer adventitial half. Scanning electron microscope analyses suggest different failure modalities of dissection between the two morphologies, and the lower S d in ATAAs appears to be associated with a disorganized microstructure. BAV ATAAs have a lower S d than TAV ATAAs, suggesting a greater propensity for aortic dissection. © 2012 by The American Association for Thoracic Surgery.

Di Caro V.,University of Pittsburgh | Di Caro V.,Rimed | Phillips B.,Pennsylvania State University | Engman C.,University of Pittsburgh | And 3 more authors.
Clinical and Experimental Immunology | Year: 2013

While much is known about tolerogenic dendritic cell effects on forkhead box protein 3 (FoxP3)+ regulatory T cells, virtually nothing is known about their effects on another arm of immunoregulation that is mediated by a subpopulation of immunosuppressive B cells. These cells suppress rheumatoid arthritis, lupus and inflammatory bowel disease in mice, and functional defects have been reported in human lupus. We show that co-stimulation-impaired tolerogenic dendritic cells that prevent and reverse type 1 diabetes mellitus induce the proliferation of human immunosuppressive B cells in vitro. We also show that the suppressive properties of these B cells concentrate inside the CD19+CD24+ B cell population and more specifically inside the CD19+CD24+CD38+ regulatory B cell population. We discovered that B cell conversion into suppressive cells in vitro is partially dependent on dendritic cell production of retinoic acid and also that CD19+CD24+CD38+ B regulatory cells express retinoic acid receptors. Taken together, our data suggest a model whereby part of the immunosuppressive properties of human tolerogenic dendritic cells could be mediated by retinoic acid which, in addition to its known role in favouring T cell differentiation to FoxP3+ regulatory T cells, acts to convert B cells into immunosuppressive cells. © 2013 British Society for Immunology.

Francipane M.G.,McGowan Institute for Regenerative Medicine | Francipane M.G.,Rimed | Lagasse E.,McGowan Institute for Regenerative Medicine
Oncotarget | Year: 2013

Metastatic colorectal cancer (CRC) is incurable for most patients. Since mammalian target of rapamycin (mTOR) has been suggested as a crucial modulator of tumor biology, we aimed at evaluating the effectiveness of mTOR targeting for CRC therapy. To this purpose, we analyzed mTOR expression and the effect of mTOR inhibition in cancer stem-like cells isolated from three human metastatic CRCs (CoCSCs). CoCSCs exhibited a strong mTOR complex 2 (mTORC2) expression, and a rare expression of mTOR complex 1 (mTORC1). This latter correlated with differentiation, being expressed in CoCSC-derived xenografts. We indicate Serum/glucocorticoid-regulated kinase 1 (SGK1) as the possible main mTORC2 effector in CoCSCs, as highlighted by the negative effect on cancer properties following its knockdown. mTOR inhibitors affected CoCSCs differently, resulting in proliferation, autophagy as well as apoptosis induction. The apoptosis-inducing mTOR inhibitor Torin-1 hindered growth, motility, invasion, and survival of CoCSCs in vitro, and suppressed tumor growth in vivo with a concomitant reduction in vessel formation. Torin-1 also affected the expression of markers for cell proliferation, angio-/lympho-genesis, and stemness in vivo, including Ki67, DLL1, DLL4, Notch, Lgr5, and CD44. Importantly, Torin-1 did not affect the survival of normal colon stem cells in vivo, suggesting its selectivity towards cancer cells. Thus, we propose Torin-1 as a powerful drug candidate for metastatic CRC therapy.

Sepe S.,Erasmus Medical Center | Payan-Gomez C.,Erasmus Medical Center | Payan-Gomez C.,El Rosario University | Milanese C.,Erasmus Medical Center | And 3 more authors.
DNA Repair | Year: 2013

Impaired DNA repair involving the nucleotide excision repair (NER)/transcription-coupled repair (TCR) pathway cause human pathologies associated with severe neurological symptoms. These clinical observations suggest that defective NER/TCR might also play a critical role in chronic neurodegenerative disorders (ND), such as Alzheimer's and Parkinson's disease. Involvement of NER/TCR in these disorders is also substantiated by the evidence that aging constitutes the principal risk factor for chronic ND and that this DNA repair mechanism is very relevant for the aging process itself. Our understanding of the exact role of NER/TCR in chronic ND, however, is extremely rudimentary; while there is no doubt that defective NER/TCR can lead to neuronal death, evidence for its participation in the etiopathogenesis of ND is inconclusive thus far. Here we summarize the experimental observations supporting a role for NER/TCR in chronic ND and suggest questions and lines of investigation that might help in addressing this important issue. We also present a preliminary yet unprecedented meta-analysis on human brain microarray data to understand the expression levels of the various NER factors in the anatomical areas relevant for chronic ND pathogenesis. In summary, this review intends to highlight elements supporting a role of NER/TCR in these devastating disorders and to propose potential strategies of investigation. © 2013 Elsevier B.V.

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