Publications by authors named "Alan M Robinson"

Synchronized beating of cilia on multiciliated cells (MCCs) generates a directional flow of mucus across epithelia. This motility requires a "9 + 2" microtubule (MT) configuration in axonemes and the unidirectional array of basal bodies of cilia on the MCCs. However, it is not fully understood what components are needed for central MT-pair assembly as they are not continuous with basal bodies in contrast to the nine outer MT doublets.

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Background And Objective: The aim of this study was to determine if X-ray micro-computed tomography could be used to locate and characterize tissue damage caused by laser irradiation and to describe its advantages over classical histology for this application.

Study Design/materials And Methods: A surgical CO laser, operated in single pulse mode (100 milliseconds) at different power settings, was used to ablate different types of cadaveric animal tissues. Tissue samples were then harvested and imaged with synchrotron X-ray phase-contrast and micro-computed tomography to generate stacks of virtual sections of the tissues.

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This animal study was designed to determine if minocycline ameliorates cochlear damage is caused by intratympanic injection of the ototoxic aminoglycoside antibiotic neomycin. Baseline auditory-evoked brainstem responses were measured in gerbils that received 40 mM intratympanic neomycin either with 0, 1.2, or 1.

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We describe a method for allergic rhinitis (AR) induction in mice. Methodology involves nasal infusions of small volumes of ovalbumin for both initial sensitization and challenges. The latter are frequent and carried out over several weeks.

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Infrared neural stimulation (INS) has been proposed as a novel method for neural stimulation. In order for INS to translate to clinical use, which would involve the use of implanted devices over years or decades, the efficacy and safety of chronic INS needs to be determined. We examined a population of cats that were chronically implanted with an optical fiber to stimulate the cochlea with infrared radiation, the first known chronic application of INS.

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Objective: Olfaction is impaired in chronic rhinosinusitis (CRS). The study has two aims: (1) to determine whether changes in cation concentration occur in the olfactory mucus of mice with CRS, which may affect chemo-electrical transduction, (2) and to examine whether these alterations are physiologically significant in humans.

Study Design: Animal study in mice and translational study in humans.

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Allergic rhinitis (AR) can cause significant olfactory loss, but few studies have specifically investigated AR effects on olfactory and nasal respiratory tissues per se. To address this, we used a murine AR protocol employing nasal allergen infusion for both sensitization and challenges. Seven- to 11-week BALB/c mice were bilaterally infused with 1% ovalbumin (OVA) in phosphate-buffered saline (PBS) or PBS alone for 6 or 11 weeks, given single bilateral PBS or OVA infusions 24 h before sacrifice, or left untreated.

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It has been demonstrated that INS can be utilized to stimulate spiral ganglion cells in the cochlea. Although neural stimulation can be achieved without direct contact of the radiation source and the tissue, the presence of fluids or bone between the target structure and the radiation source may lead to absorption or scattering of the radiation, which may limit the efficacy of INS. The present study demonstrates the neural structures in the radiation beam path that can be stimulated.

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Previous research has shown that neural stimulation with infrared radiation (IR) is spatially selective and illustrated the potential of IR in stimulating auditory neurons. The present work demonstrates the application of a miniaturized pulsed IR stimulator for chronic implantation in cats, quantifies its efficacy, and short-term safety in stimulating auditory neurons. IR stimulation of the neurons was achieved using an optical fiber inserted through a cochleostomy drilled in the basal turn of the cat cochlea and was characterized by measuring compound action potentials (CAPs).

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Objective: To determine the effects of eosinophilic inflammation on olfactory sensory neuron cell death.

Study Design: Mice were sensitized to intranasal Aspergillus fumigatus extract and subsequently challenged acutely or chronically with the same allergen. The olfactory neuroepithelium was assessed for immunohistochemical evidence of apoptosis and inflammation.

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Sensory deficits are frequently observed in cerebral palsy patients. The motor response to smell was found to be abnormal in an animal model of cerebral palsy following fetal hypoxia-ischemia. We hypothesized that fetal hypoxia-ischemia causes long-lasting and selective olfactory tract injury.

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Background: Tissue ischemia and aging are independent features associated with the healing impairment of cutaneous wounds. However, the pathophysiology of these processes as they relate to impaired-healing wounds is poorly understood.

Materials And Methods: A single full-thickness biopsy wound was made on both ears of young (3-6 month) and aged (>24 month) Fisher rats.

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Surgical ablation of the olfactory bulb (bulbectomy) triggers a massive wave of apoptosis in mature olfactory sensory neurons within the olfactory epithelium. The aim of the current study was to determine if this process is dependent on expression of the pro-apoptotic protein Bax. Immunohistochemical detection of caspase-3 activation and olfactory epithelial thickness was used to demonstrate and quantify neuronal apoptosis in bax knockout and wild type mice, following bulbectomy.

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Background: Olfactory receptor neurons (ORNs) undergo apoptosis at a baseline rate even in the absence of obvious disease. Although the precise triggers of the apoptotic cascade are unclear, ORNs are exposed directly to the external environment, making them susceptible to injury. As an adaptive mechanism, mammals have the ability to replace lost ORNs throughout adult life from neuronal precursors within the olfactory epithelium (OE).

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Objectives: Olfactory receptor neurons undergo apoptosis at a baseline rate, probably secondary to environmental damage even in the absence of gross disease. The study demonstrates age-related changes in expression of genes known to regulate apoptosis in the rat olfactory mucosa. These results are compared with gene expression in young rats and rats that have undergone surgical deafferentation of the olfactory receptor neurons.

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Background: Glutathione s-transferase pi (GSTpi) is an enzyme that provides cellular protection against redox-mediated damage by free radicals, which have been implicated in carcinogenesis.

Methods: Forty-three consecutive specimens from 19 patients were reviewed to identify samples of squamous mucosa, Barrett's metaplasia, adenocarcinoma, and peritumoral inflammation. Serial sections were stained with an anti-GSTpi polyclonal antibody, and GSTpi expression was quantified for each histologic group.

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Purpose: Apoptosis index (AI), Bcl-2, and Bax have shown prognostic significance in head and neck squamous cell carcinoma (HNSCCa). Other areas of research have implicated nitric oxide (NO) or its various intermediate species in both proapoptotic and antiapoptotic processes. We have previously shown that NO-generating enzymes are significantly increased during the stepwise progression to HNSCCa.

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