Publications by authors named "Stephen Voss"

Article Synopsis
  • The variety of color patterns in amphibians, particularly in Mexican axolotls, is linked to the development of a few pigment cell types.
  • The axolotl exhibits a range of color phenotypes, mainly featuring melanophores and fewer xanthophores, supporting the single-origin hypothesis where all pigment cells come from a common progenitor.
  • Research identified key genes on chromosome 14q that influence pigment cell differentiation, reinforcing the idea that pigment cells are directly specified during development.
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Objectives/hypothesis: Compare proteomic profiles of rabbit vocal folds (VFs) injected with micronized cross-linked jellyfish collagen "collagen Type 0" (MX-JC) against two clinical products for injection medialization laryngoplasty (IL).

Study Design: Animal model.

Methods: Left recurrent laryngeal nerve sectioning and IL were performed in New Zealand White rabbits ( = 6/group).

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One promising strategy in cell therapies for Parkinson's disease (PD) is to harness a patient's own cells to provide neuroprotection in areas of the brain affected by neurodegeneration. No treatment exists to replace cells in the brain. Thus, our goal has been to support sick neurons and slow neurodegeneration by transplanting living repair tissue from the peripheral nervous system into the substantia nigra of those with PD.

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Objectives: To examine the degree of agreement between MRI and histologically generated volumetric measurements of residual injection laryngoplasty material.

Methods: Following left recurrent laryngeal nerve transection, rabbit vocal cords were injected with jellyfish collagen, Cymetra®, or Restylane®. Laryngeal tissue was harvested 4 or 12 weeks post injection followed by MRI imaging and histologic cross-sectioning.

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Objectives/hypothesis: Test a new jellyfish collagen biomaterial aimed to increase duration of injection medialization laryngoplasty (IL) against two products in clinical practice.

Study Design: Animal model.

Methods: Left recurrent laryngeal nerve sectioning and IL were performed in New Zealand White rabbits (N = 6/group).

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Background: Lorvotuzumab mertansine (IMGN901) is an antibody-drug conjugate linking an antimitotic agent (DM1) to an anti-CD56 antibody (lorvotuzumab). Preclinical efficacy has been noted in Wilms tumor, rhabdomyosarcoma, and neuroblastoma. Synovial sarcoma, malignant peripheral nerve sheath tumor (MPNST), and pleuropulmonary blastoma also express CD56.

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Craniofacial reconstruction of critical bone defects typically requires a bone graft. As graft availability may be restricted by disease or comorbidities, tissue engineering approaches are actively sought. The pericranium could provide new bone graft material.

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Objectives: Rabbit adipose mesenchymal stem cells were used for the purpose of studying acquisition of the chondrogenic phenotype over time at 1, 14 and 28 days after in vitro incubation with differentiation media, using nano-liquid chromatography electrospray ionization tandem mass spectrometry analysis. This was part of a preliminary study of the behavior of differentiated adipose stem cells for use in a rabbit model of laryngoplasty.

Data Description: The data comprise .

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Objectives/hypothesis: Vocal fold (VF) paralysis by sectioning the recurrent laryngeal nerve dramatically impacts the life of thyroidectomy patients. Volume-expanding materials can temporarily restore VF medialization. To prolong this benefit, adipose mesenchymal stem cells (ADSCs) and micronized acellular dermis (MACD) were co-injected in a rabbit model of injection medialization laryngoplasty.

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Osteoporosis is a disorder of the bones in which they are weakened to the extent that they become more prone to fracture. There are various forms of osteoporosis: some of them are induced by drugs, and others occur as a chronic progressive disorder as an individual gets older. As the median age of the population rises across the world, the chronic form of the bone disease is drawing attention as an important worldwide health issue.

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Objective Human adipose-derived mesenchymal stem cells (ADSCs) were used to rehabilitate bone damaged by osteoradionecrosis (ORN) in an established animal model. Study Design Prospective animal study. Setting Academic department laboratory.

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Importance: Nasal reconstruction in patients who are missing a significant amount of structural nasal support remains a difficult challenge. One challenge is the deficiency of cartilage left within the nose as a consequence of rhinectomy or a midline destructive disease. Historically, the standard donor source for large quantities of native cartilage has been costal cartilage.

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Objective/hypothesis: Eosinophilic otitis media (EOM) is a variant of chronic otitis media that is characterized by the development of thick mucoid middle ear effusion, adult onset bronchial asthma, sinonasal polyposis, and aspirin sensitivity. EOM is typically refractory to corticosteroid therapy and surgical intervention. Pegylated interferon (PEG-IFN) has effectively treated hypereosinophilic syndrome in clinical trials; however, the efficacy of this medication for EOM treatment remains undefined.

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Background: The appropriate operative approach to pediatric patients with ovarian tumors must balance real risk of malignancy with maximal preservation of reproductive potential. We evaluate preoperative risk of malignancy in order to more precisely guide treatment, so as to err on the side of ovarian preservation if at all possible.

Methods: We retrospectively reviewed the records of all patients undergoing surgical intervention for ovarian tumors at a single institution.

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Objective: We aim to create a model of mandibular osteoradionecrosis in athymic rats. Athymic rats provide an immunosuppressed environment whereby human stem cells and biomaterials can be used to investigate regenerative solutions for osteoradionecrosis, bridging the gap between in vivo testing and clinical application.

Study Design: Prospective animal study.

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Purpose: Supramaximal facial nerve stimulation is an applied current sufficient to evoke a maximal electromyographic response of facial musculature. It is used during cerebellopontine angle surgery for prognostication of postoperative nerve function. We utilized a rat model to examine safe parameters for intracranial electrical stimulation.

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Very little is known about genetic factors that regulate life history transitions during ontogeny. Closely related tiger salamanders (Ambystoma species complex) show extreme variation in metamorphic timing, with some species foregoing metamorphosis altogether, an adaptive trait called paedomorphosis. Previous studies identified a major effect quantitative trait locus (met1) for metamorphic timing and expression of paedomorphosis in hybrid crosses between the biphasic Eastern tiger salamander (Ambystoma tigrinum tigrinum) and the paedomorphic Mexican axolotl (Ambystoma mexicanum).

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Hox genes encode transcription factors that regulate embryonic and post-embryonic developmental processes. The expression of Hox genes is regulated in part by the tight, spatial arrangement of conserved coding and non-coding sequences. The potential for evolutionary changes in Hox cluster structure is thought to be low among vertebrates; however, recent studies of a few non-mammalian taxa suggest greater variation than originally thought.

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Objectives/hypothesis: The purpose of this study was to evaluate the Ras GTPase (Ras) to extracellular signal-regulated kinase (ERK) pathway in vestibular schwannoma (VS) cell cultures and patient excised schwannoma tumors. Mitogen-activated protein kinase kinase (MEK) inhibitor CI-1040 (PD184352) was utilized to evaluate the effect of specific MEK inhibition on benign schwannoma cell culture proliferation and apoptosis.

Study Design: Prospective evaluation of human schwannoma cell lines and tumors.

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Amphibian genomes differ greatly in DNA content and chromosome size, morphology, and number. Investigations of this diversity are needed to identify mechanisms that have shaped the evolution of vertebrate genomes. We used comparative mapping to investigate the organization of genes in the Mexican axolotl (Ambystoma mexicanum), a species that presents relatively few chromosomes (n = 14) and a gigantic genome (>20 pg/N).

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Hypothesis: B7-H1 is expressed in vestibular schwannomas.

Background: Little is known about how benign human vestibular schwannomas interact with antibody-mediated or cell-mediated immunity. We report on the aberrant expression of a novel T-cell coregulatory molecule, B7 homolog 1 (B7-H1), in vestibular schwannomas and discuss the implications of B7-H1 expression and tumor aggressiveness and a potential regulator of B7-H1 expression.

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Background: The Mexican axolotl (Ambystoma mexicanum) is considered a hopeful monster because it exhibits an adaptive and derived mode of development - paedomorphosis - that has evolved rapidly and independently among tiger salamanders. Unlike related tiger salamanders that undergo metamorphosis, axolotls retain larval morphological traits into adulthood and thus present an adult body plan that differs dramatically from the ancestral (metamorphic) form. The basis of paedomorphic development was investigated by comparing temporal patterns of gene transcription between axolotl and tiger salamander larvae (Ambystoma tigrinum tigrinum) that typically undergo a metamorphosis.

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Hypothesis: Intracranial vestibular schwannoma xenografts can be successfully established and followed with bioluminescent imaging (BLI).

Background: Transgenic and xenograft mouse models of vestibular schwannomas have been previously reported in the literature. However, none of these models replicate the intracranial location of these tumors to reflect the human disease.

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Background: Thyroid hormones (TH) induce gene expression programs that orchestrate amphibian metamorphosis. In contrast to anurans, many salamanders do not undergo metamorphosis in nature. However, they can be induced to undergo metamorphosis via exposure to thyroxine (T4).

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The role of human bone marrow (BM) CD8+ T cells in the immune response to viral Ags is poorly defined. We report here the identification and characterization of a functionally enhanced effector memory CD8+ T cell population (TEM) in the BM of patients undergoing total joint replacement for osteoarthritis. These BM-derived TEM differ strikingly from correlate cells in peripheral blood (PB), expressing elevated levels of CD27, HLA-DR, CD38, CD69, and unique patterns of chemokine receptors.

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