Publications by authors named "Kyle D Smith"

Front-line pharmaceutical treatment for treatment of acute graft-versus-host disease (aGVHD) is not uniformly effective and has toxic side effects. Myeloid-derived suppressor cells (MDSCs) are a heterogeneous population of immature myeloid cells with potent in vitro and in vivo immunosuppressive functions. Clinical translation of in vitro generated MDSCs has been limited by the need for high MDSC:T cell ratios, multiple infusions to reduce inflammation and a relatively low peripheral blood-derived MDSC (PB-MDSCs) yield.

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The success of allogeneic hematopoietic stem cell transplantation (allo-HSCT) can be limited by graft-versus-host disease (GVHD). T-cell activation is a key factor in GVHD progression. Costimulatory signals can be counterbalanced by coinhibitory signals such as the checkpoint molecule VISTA (V-domain immunoglobulin-containing suppressor of T-cell activation)/programmed death-1 homolog that restrains activation and maintains donor T-cell quiescence.

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Sepsis is a devastating disease with high morbidity and mortality and no specific treatments. The pathophysiology of sepsis involves a hyperinflammatory response and release of damage-associated molecular patterns (DAMPs), including adenosine triphosphate (ATP), from activated and dying cells. Purinergic receptors activated by ATP have gained attention for their roles in sepsis, which can be pro- or anti-inflammatory depending on the context.

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The mechanisms of latency in the context of infection remain poorly understood. Two reasons for this gap in knowledge are: 1) the lack of standardized criteria for defining latent cryptococcosis in animal models and 2) limited genetic and immunological tools available for studying host parameters against in non-murine models of persistent infection. In this study, we defined criteria required for latency in infection models and used these criteria to develop a murine model of persistent infection using clinical isolates.

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Introduction: Repeated blast exposures result in structural damage to the peripheral auditory system (PAS) and the central auditory system (CAS). However, it is difficult to differentiate injuries between two distinct pathways: the mechanical damage in the PAS caused by blast pressure waves transmitted through the ear and the damage in the CAS caused by blast wave impacts on the head or traumatic brain injury. This article reports a preliminary study using a 3D printed chinchilla "helmet" as a head protection device associated with the hearing protection devices (e.

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Mechanical properties of the tympanic membrane (TM) play an important role in sound transmission through the middle ear. While numerous studies have investigated the mechanical properties of the adult human TM, the effects of age on the TM's properties remain unclear because of the limited published data on the TM of young children. To address this deprivation, we used baboons in this study as an animal model for investigating the effect of age on the mechanical properties of the TM.

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Introduction: The peripheral auditory system and various structures within the central auditory system are vulnerable to blast injuries, and even blast overpressure is at relatively mild traumatic brain injury (TBI) level. However, the extent of hearing loss in relation to blast number and time course of post-blast is not well understood. This study reports the progressive hearing damage measured in chinchillas after multiple blast exposures at mild TBI levels (103-138 kPa or 15-20 psi).

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Lymph node stromal cells (LNSCs) regulate immunity through constructing lymphocyte niches. LNSC-produced laminin α5 (Lama5) regulates CD4+ T cells but the underlying mechanisms of its functions are poorly understood. Here we show that depleting Lama5 in LNSCs resulted in decreased Lama5 protein in the LN cortical ridge (CR) and around high endothelial venules (HEVs).

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The rupture of the tympanic membrane (TM) is one of the major indicators for blast injuries due to the vulnerability of TM under exposure to blast overpressure. The mechanical properties of the human TM exhibit a significant change after it is exposed to such a high intensity blast. To date, the published data were obtained from measurement on TM strips cut from a TM following an exposure to blast overpressure.

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Patient outcomes during infection are due to a complex interplay between the quality of medical care, host immunity factors, and the infecting pathogen's characteristics. To probe the influence of pathogen genotype on human survival, immune response, and other parameters of disease, we examined isolates collected during the Cryptococcal Optimal Antiretroviral Therapy (ART) Timing (COAT) Trial in Uganda. We measured human participants' survival, meningitis disease parameters, immunologic phenotypes, and pathogen growth characteristics.

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Mechanical properties of the tympanic membrane (TM) are important for studying the transfer function of the auditory system. However, nearly all reported human data are limited to adults because of the unavailability of temporal bones from children. In this study, we used the baboon (Papio anubis), a genetically close human relative, as a model to address the occurrence of age-dependent changes of the human TM.

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Many pulmonary infections elicit lymphocyte responses that lead to an accumulation of granulocytes in the lungs. A variety of lymphocytes are capable of directing eosinophils or neutrophils to the lungs, but the contribution of each subset remains enigmatic. In this study, we used a murine model to examine lymphocyte subsets that ultimately drive the eosinophil or neutrophil response to infection with the fungal pathogen Cryptococcus neoformans.

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Many plasmids used for gene cloning and heterologous protein expression in Escherichia coli cells are low copy number or single copy number plasmids. The extraction of these types of plasmids from small bacterial cell cultures produces low DNA yields. In this study, we have quantitated yields of low copy and single copy number plasmid DNAs after growth of cells in four widely used broths (SB, SOC, TB, and 2xYT) and compared results to those obtained with LB, the most common E.

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Although antifungal drug resistance in the human fungal pathogen Cryptococcus neoformans is relatively uncommon, fluconazole-resistant strains are problematic for preemptive treatment of cryptococcal antigenemia or during cryptococcal meningitis consolidation therapy. We analyzed activity of the experimental antifungal VT-1129 on 51 clinical Cryptococcus neoformans isolates previously screened for fluconazole resistance; with an emphasis on fluconazole dose-dependent (MIC 16-32 μg/ml) or resistant (MIC ≥ 64 μg/ml) isolates. Overall, the VT-1129 geometric mean MIC was 0.

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Background: Cryptococcus is the most common cause of adult meningitis in Africa. We assessed the safety and microbiological efficacy of adjunctive sertraline, previously shown to have in-vitro and in-vivo activity against cryptococcus.

Methods: In this open-label dose-finding study, we recruited HIV-infected individuals with cryptococcal meningitis who presented to Mulago Hospital in Kampala, Uganda between Aug 14, 2013, and Aug 30, 2014.

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Lethal disease caused by the fungus Cryptococcus neoformans is a consequence of the combined failure to control pulmonary fungal replication and immunopathology caused by induced type 2 Th2 cell responses in animal models. In order to gain insights into immune regulatory networks, we examined the role of regulatory T (Treg) cells in suppression of Th2 cells using a mouse model of experimental cryptococcosis. Upon pulmonary infection with Cryptococcus, Treg cells accumulated in the lung parenchyma independently of priming in the draining lymph node.

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Cryptococcal antigen screening is recommended among people living with AIDS when entering HIV care with a CD4 count of <100 cells/μl, and preemptive fluconazole monotherapy treatment is recommended for those with subclinical cryptococcal antigenemia. Yet, knowledge is limited of current antimicrobial resistance in Africa. We examined antifungal drug susceptibility in 198 clinical isolates collected from Kampala, Uganda, between 2010 and 2014 using the CLSI broth microdilution assay.

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Pulmonary mycoses are often associated with type-2 helper T (Th2) cell responses. However, mechanisms of Th2 cell accumulation are multifactorial and incompletely known. To investigate Th2 cell responses to pulmonary fungal infection, we developed a peptide-MHCII tetramer to track antigen-specific CD4+ T cells produced in response to infection with the fungal pathogen Cryptococcus neoformans.

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The objective of this study was to determine the prevalence of concha bullosa and nasal septal deviation and their potential relationships to maxillary sinusitis. 883 CT scans taken at Creighton University School of Dentistry from 2005 to 2008 were retrospectively reviewed for the presence of concha bullosa, nasal septal deviation, and maxillary sinusitis. 67.

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