Publications by authors named "Dower N"

Speech-language pathologists and board-certified behavior analysts both provide important support services to children who are candidates for augmentative and alternative communication. Current assessment practices neglect critical socioecological factors that are necessary to inform communication-based interventions. By leveraging the unique knowledge, research, and expertise of both disciplines, an interprofessional approach to assessment may help realize individualized or precision interventions and personalized supports that address the unique communication needs of each person.

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Objectives: The objective of the study was to evaluate whether a twice-daily instillation of 0.45% preservative-free ketorolac tromethamine (FKT) or 0.4% benzalkonium chloride-preserved ketorolac tromethamine (BACKT), every 12 h for 30 days may affect tear film parameters and the meibography in healthy dogs.

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Objective: To assess the effectiveness of various sealing techniques in cholecystotomies under maximum intraluminal pressure stress using an ex vivo swine model.

Sample: 30 gallbladders from different animals were used.

Methods: The experiment was conducted ex vivo, with the formation of 3 groups, each comprising 10 samples.

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Objectives: To determine the concentrations of total protein (TP), tissue inhibitor of matrix metalloproteinase-1 (TIMP-1) and hyaluronic acid (HA) in amniotic membranes (AMs) harvested from placentas of bitches of different ages and cryopreserved for different time points. The outcomes of complicated corneal defects of dogs repaired with AMs stored for the same time points were also evaluated.

Procedures: Ten cryopreserved canine AMs were stored for short term (2-50 days), middle term (92-210 days), or long term (256-357 days).

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Objectives: To investigate the effects of the intracameral injection of epinephrine and two doses of 2% lidocaine on pupil diameter (PD), intraocular pressure (IOP), heart rate (HR), and mean arterial pressure (MAP) in healthy cats.

Methods: Five treatment groups were formed (10 cats/each). Animals received 0.

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Purpose: To evaluate the maximal intraluminal pressure (MIP) supported by canine cadaveric urinary bladders that underwent cystotomy followed by cystorraphy, with and without serosal patching-supplementation.

Methods: Two groups (n=8 each) were formed, and in one (conventional) the cystotomy was closed with cushing pattern. In the other group (serosal), the same procedure was performed, and a piece of jejunum was used for the construction of the serosal patching over the cystorraphy.

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Ingenol-3-angelate (I3A) is a non-tumor promoting phorbol ester-like compound identified in the sap of Euphoria peplus. Similar to tumor promoting phorbol esters, I3A is a diacylglycerol (DAG) analogue that binds with high affinity to the C1 domains of PKCs, recruits PKCs to cellular membranes and promotes enzyme activation. Numerous anti-cancer activities have been attributed to I3A and ascribed to I3A's effects on PKCs.

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T cell development is a highly dynamic process that is driven by interactions between developing thymocytes and the thymic microenvironment. Upon entering the thymus, the earliest thymic progenitors, called CD4(-)CD8(-) 'double negative' (DN) thymocytes, pass through a checkpoint termed "β-selection" before maturing into CD4(+)CD8(+) 'double positive' (DP) thymocytes. β-selection is an important developmental checkpoint during thymopoiesis where developing DN thymocytes that successfully express the pre-T cell receptor (TCR) undergo extensive proliferation and differentiation towards the DP stage.

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The anti-cancer effects of bryostatin-1, a potent diacylglycerol analogue, have traditionally been attributed to its action on protein kinase C. However, we previously documented apoptosis in a B non-Hodgkin lymphoma cell line involving diacylglycerol analogue stimulation of Ras guanyl-releasing protein, a Ras activator, and Bim, a proapoptotic Bcl-2 family protein. To further explore the role of Bim, we examined several Bim-deficient B non-Hodgkin lymphoma cells for their responses to pico, a synthetic bryostatin-1-like compound.

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Introduction: Inherited bone marrow failure syndromes (IBMFSs) often have substantial phenotypic overlap, thus genotyping is often critical for establishing a diagnosis.

Objectives And Methods: To determine the genetic characteristics and mutation profiles of IBMFSs, a comprehensive population-based study that prospectively enrols all typical and atypical cases without bias is required. The Canadian Inherited Marrow Failure Study is such a study, and was used to extract clinical and genetic information for patients enrolled up to May 2010.

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The recurrence of cerebral palsy in the same family is uncommon. We, however, report on two families with two or more affected siblings. In both families, numerous potential risk factors were identified including environmental, obstetric, and possible maternal effects.

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Our knowledge of the phenotypes of inherited bone marrow failure syndromes (IBMFSs) derives from case reports or case series in which only one IBMFS was studied. However, the substantial phenotypic overlap necessitates comparative analysis between the IBMFSs. Shwachman-Diamond syndrome (SDS) is an IBMFS that the appreciation of what comprises its clinical phenotype is still evolving.

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RasGRP1 is a guanine nucleotide exchange factor for Ras that binds with high affinity to diacylglycerol analogs like the phorbol esters. Recently, we demonstrated a role for RasGRP1 in skin carcinogenesis and suggested its participation in the action of tumor-promoting phorbol esters like 12-O-tetradecanoylphorbol-13-acetate (TPA) on Ras pathways in epidermal cells. Given the importance of Ras in carcinogenesis, we sought to discern whether RasGRP1 was a critical pathway in Ras activation, using a RasGRP1 knockout (KO) mouse model to examine the response of keratinocytes to TPA.

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Models of epidermal carcinogenesis have demonstrated that Ras is a critical molecule involved in tumor initiation and progression. Previously, we have shown that RasGRP1 increases the susceptibility of mice to skin tumorigenesis when overexpressed in the epidermis by a transgenic approach, related to its ability to activate Ras. Moreover, RasGRP1 transgenic mice develop spontaneous papillomas and cutaneous squamous cell carcinomas, some of which appear to originate in sites of injury, suggesting that RasGRP1 may be responding to signals generated during the wound-healing process.

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Objective: Bryostatin-1 and related diacylglycerol (DAG) analogues activate RasGRPs in lymphocytes, thereby activating Ras and mimicking some aspects of immune receptor signaling. To define the role of RasGRPs in lymphocyte apoptosis and to identify potential therapeutic uses for DAG analogues in lymphocyte disorders, we characterized the response of lymphoma-derived cell lines to DAG analogues.

Materials And Methods: Human lymphoma-derived B cell lines and mouse primary B cells were treated with bryostatin-1 or its synthetic analogue "pico.

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Background: During infancy, a male patient experienced several life-threatening bleeding episodes. Standard coagulation tests revealed that the patient's plasma prothrombin activity was 8%, while his father's and mother's levels were 74% and 62%, respectively.

Objectives: A molecular genetic approach was used to determine the molecular basis of prothrombin deficiency within the family.

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RasGRP1 links TCR signaling to Ras in T cells, while both RasGRP1 and RasGRP3 link BCR signaling to Ras in B cells. T cells deficient in RasGRP1 have defective proliferative responses as do B cells deficient in both RasGRP1 and RasGRP3, confirming the importance of Ras activation in lymphocyte proliferation. While aged Rasgrp1-/- mice develop late-onset autoimmunity characterized by splenomegaly and the presence of anti-nuclear antibodies (ANA), the additional loss of RasGRP3 expression inhibits this phenotype.

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The RasGRPs are a family of Ras activators that possess diacylglycerol-binding C1 domains. In T cells, RasGRP1 links TCR signaling to Ras. B cells coexpress RasGRP1 and RasGRP3.

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The functional properties of four diacylglycerol (DAG) analogues were compared using cell-signaling assays based on the protein RasGRP1, a DAG-regulated Ras activator. Compounds 1 and 2, synthetic analogues of bryostatin 1, were compared to authentic bryostatin 1 and phorbol 12-myristate-13-acetate (PMA). The two "bryologues" were able to activate RasGRP1 signaling rapidly in cultured cells and isolated mouse thymocytes.

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Unfractionated heparin (UFH) is immunogenic, and heparin-dependent antibodies can be demonstrated 5 to 10 days postoperatively in 25% to 50% of adult postcardiac surgery patients. In a minority of these cases (1% to 3% if UFH is continued longer than 1 week) these antibodies strongly activate platelets, causing thrombocytopenia and massive thrombin generation (HIT syndrome). HIT is an intensely procoagulant disorder, and in adult cardiac surgery patients carries both significant thrombotic morbidity (38% to 81%) and mortality (28%).

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Background: People with sickle cell disease are particularly susceptible to pneumococcal infection, which may be fatal. Infants (children aged up to 23 months) are at particularly high risk, but conventional polysaccharide pneumococcal vaccines may be ineffective in this age group. New conjugate pneumococcal vaccines are now available, which may help to reduce the incidence of infection in people with sickle cell disease.

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A mouse strain was identified with a recessive genetic lesion, which spontaneously developed a lymphoproliferative autoimmune syndrome exhibiting features of systemic lupus erythematosus. Positional mapping of the disease-associated locus revealed a lesion in Rasgrp1 that prevented the translation of the RasGRP1 protein. T cells from these mice failed to activate Ras or proliferate vigorously following antigen encounter and showed defects in positive selection.

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Two important Ras-guanyl nucleotide exchange factors, Sos and RasGRP1, control Ras activation in thymocytes. However, the relative contribution of these two exchange factors to Ras/ERK activation and their resulting impact on positive and negative selection is unclear. We have produced two lines of RasGRP1(-/-) TCR transgenic mice to determine the effect of RasGRP1 in T cell development under conditions of defined TCR signaling.

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Ras signal transduction pathways have been implicated as key regulators in neuroplasticity and synaptic transmission in the brain. These pathways can be modulated by Ras guanyl nucleotide exchange factors, (GEF) which activate Ras proteins by catalysing the exchange of GDP for GTP. Ras guanyl nucleotide-releasing protein (RasGRP), a recently discovered Ras GEF, that links diacylglycerol and probably calcium to Ras signaling pathways, is expressed in brain as well as in T-cells.

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