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Dennis Bourdette

Publications and source records attributed to Dennis Bourdette.

10 recordsLinked to original sources
PubMed2006

Complementary and alternative medicine: is there a role in multiple sclerosis?

Despite effective conventional therapies for multiple sclerosis (MS), many people with MS explore complementary and alternative medicine (CAM) therapies for their symptoms. Common CAM therapies that people use include dietary modification, nutritional and herbal supplementation, and mind-body therapies. There is a revival of interest among MS researchers about the therapeutic potential of low-fat diet and essential fatty acid supplementation in MS. The efficacy of specific vitamin supplementation remains unclear. Recently, cannabis and yoga have been studied in more controlled studies and have provided evidence that they may have some benefit. The research on CAM therapies in MS is still exploratory, but considering peoples' interest and common use of these therapies, further research in this area is clearly warranted.

Bee Venoms↗
PubMed2006

Frequency-modulation (FM) technology as a method for improving speech perception in noise for individuals with multiple sclerosis.

Almost half of the population with multiple sclerosis (MS) complains of difficulty hearing, despite having essentially normal pure-tone thresholds. The purpose of the present investigation was to evaluate the effects of frequency-modulation (FM) technology utilization on speech perception in noise for adults with and without MS. Sentence material was presented at a constant level of 65 dBA Leq from a loudspeaker located at 0 degrees azimuth. The microphone of the FM transmitter was placed 7.5 cm from this loudspeaker. Multitalker babble was presented from four loudspeakers positioned at 45 degrees, 135 degrees, 225 degrees, and 315 degrees azimuths. The starting presentation level for the babble was 55 dBA Leq, The level of the noise was increased systematically in 1 dB steps until the subject obtained 0% key words correct on the IEEE (Institute for Electrical and Electronic Engineers) sentences. Test results revealed significant differences between the unaided and aided conditions at several signal-to-noise ratios.

Acoustic Stimulation↗
PubMed2005

Decreased FOXP3 levels in multiple sclerosis patients.

Autoimmune diseases such as multiple sclerosis (MS) may result from the failure of tolerance mechanisms to prevent expansion of pathogenic T cells. Our study is the first to establish that MS patients have abnormalities in FOXP3 message and protein expression levels in peripheral CD4+ CD25+ T cells (Tregs) that are quantitatively related to a reduction in functional suppression induced during suboptimal T-cell receptor (TCR) ligation. Of importance, this observation links a defect in functional peripheral immunoregulation to an established genetic marker that has been unequivocally shown to be involved in maintaining immune tolerance and preventing autoimmune diseases. Diminished FOXP3 levels thus indicate impaired immunoregulation by Tregs that may contribute to MS. Future studies will evaluate the effects of therapies known to influence Treg cell function and FOXP3 expression, including TCR peptide vaccination and supplemental estrogen.

Adult↗
PubMed2005

Centella asiatica accelerates nerve regeneration upon oral administration and contains multiple active fractions increasing neurite elongation in-vitro.

Axonal regeneration is important for functional recovery following nerve damage. Centella asiatica Urban herb, also known as Hydrocotyle asiatica L., has been used in Ayurvedic medicine for centuries as a nerve tonic. Here, we show that Centella asiatica ethanolic extract (100 microg mL-1) elicits a marked increase in neurite outgrowth in human SH-SY5Y cells in the presence of nerve growth factor (NGF). However, a water extract of Centella was ineffective at 100 microg mL-1. Sub-fractions of Centella ethanolic extract, obtained through silica-gel chromatography, were tested (100 microg mL-1) for neurite elongation in the presence of NGF. Greatest activity was found with a non-polar fraction (GKF4). Relatively polar fractions (GKF10 to GKF13) also showed activity, albeit less than GKF4. Thus, Centella contains more than one active component. Asiatic acid (AA), a triterpenoid compound found in Centella ethanolic extract and GKF4, showed marked activity at 1 microM (microg mL-1). AA was not present in GKF10 to GKF13, further indicating that other active components must be present. Neurite elongation by AA was completely blocked by the extracellular-signal-regulated kinase (ERK) pathway inhibitor PD 098059 (10 microM). Male Sprague-Dawley rats given Centella ethanolic extract in their drinking water (300-330 mg kg-1 daily) demonstrated more rapid functional recovery and increased axonal regeneration (larger calibre axons and greater numbers of myelinated axons) compared with controls, indicating that the axons grew at a faster rate. Taken together, our findings indicate that components in Centella ethanolic extract may be useful for accelerating repair of damaged neurons.

Administration, Oral↗
PubMed2004

Complementary and alternative medicine in multiple sclerosis: survey of licensed naturopaths.

OBJECTIVE: This paper describes the treatments and treatment outcome measures used by licensed naturopathic physicians in the United States who treat people with multiple sclerosis (MS). DESIGN: A cross-sectional mail survey was used. SUBJECTS: The participants were licensed naturopaths who were members of the American Association of Naturopathic Physicians. OUTCOME MEASURES: Outcome measures included practitioner demographics; patient demographics by practitioner report; recommended therapies; perceived effectiveness of treatments for MS; methods for measuring treatment effectiveness. RESULTS: Forty three percent (43%) of the respondents (166/385) had treated at least one patient with MS while 56.9% (291/385) had never treated MS. 63.3% had treated 1-10 patients with MS, 19.9% had treated 11-20 patients with MS, and 16.8% had treated > or =20 patients with MS. Among the naturopaths, 68.1% communicated with an M.D. about their patient(s)' care and the majority of patients with MS were diagnosed by an M.D. (mean % = 96.3). The mean number of therapies recommended for M.S. was 3.91 (standard deviation [SD] =2.01, range 1-10). The most frequently recommended therapies included, diet (52.4%), essential fatty acid supplementation (44.6%), vitamin/mineral supplementation (33.7%), homeopathy (30.7%), botanicals (22.3%), and antioxidants (18.1%). Respondents perceived their treatments as "very effective" for the following stages of MS: early stage (57.2%); middle stage (25.3%); and late stage (3.0%). Respondents perceived their treatments as "very effective" for the following disease-related outcomes: improved quality of life (59.0%); decrease relapse rates (48.2%); decreased symptom severity (45.8%); prevention of disease progression (41.6%). The methods used "most often" for measuring treatment effectiveness included, patient report (88.0%); physical examination (27.1%); medical records/laboratory testing (13.3%). The mean estimated percentage of patients not taking conventional disease-modifying medication was 51.2% (SD = 42.7%). CONCLUSIONS: Naturopaths use both a broad range and multiple complementary and alternative medicine CAM therapies for treating MS and report treatment effectiveness on the following outcomes: quality of life; symptom severity; relapse rates; and disease progression. Further research on single CAM therapies and holistic CAM systems is warranted in MS.

Complementary Therapies↗
PubMed2004

Neuroregenerative and neuroprotective actions of neuroimmunophilin compounds in traumatic and inflammatory neuropathies.

FK506 (tacrolimus, Prograf is an immunosuppressant drug that also has profound neuroregenerative and neuroprotective actions independent of its immunosuppressant activity. The separation of these properties has led to the development of non-immunosuppressant derivatives that retain the neurotrophic activity. This review focuses on the peripheral nerve actions of these compounds following mechanical injury (nerve crush or transection with graft repair) and in models of inflammatory neuropathies. Whereas FK506 may be indicative for the treatment of inflammatory neuropathies where its immunosuppressive action would be advantageous, non-immunosuppressant derivatives represent a new class of potential therapeutic agents for the treatment of human neurological conditions in general. Moreover, these studies have led to the discovery of a novel mechanism whereby these compounds activate intrinsic neuroregenerative and neuroprotective pathways in the neuron.

Animals↗
PubMed2003

Epitope spreading is not required for relapses in experimental autoimmune encephalomyelitis.

The sequential emergence of specific T lymphocyte-mediated immune reactivity directed against multiple distinct myelin epitopes (epitope spreading) has been associated with clinical relapses in experimental autoimmune encephalomyelitis (EAE), an animal model of multiple sclerosis (MS). Based on this association, an appealing and plausible model for immune-mediated progression of the advancing clinical course in MS and EAE has been proposed in which epitope spreading is the cause of clinical relapses in T cell-mediated CNS inflammatory diseases. However, the observed association between epitope spreading and disease progression is not universal, and absolute requirements for epitope spreading in progressive EAE have not been tested in the absence of multiple T cell specificities, because most prior studies have been conducted in immunocompetent mouse strains that possessed broad TCR repertoires. Consequently, the precise nature of a causal relationship between epitope spreading and disease progression remains uncertain. To determine whether relapsing or progressive EAE can occur in the absence of epitope spreading, we evaluated the course of disease in mice which possessed only a single myelin-specific TCR. These mice (transgenic/SCID +/+) exhibited a progressive and sometimes remitting/relapsing disease course in the absence of immune reactivity to multiple, spreading myelin epitopes. The results provide direct experimental evidence relevant to discussions on the mechanisms of disease progression in MS and EAE.

Adoptive Transfer↗
PubMed2003

Nonmyelin-specific T cells accelerate development of central nervous system APC and increase susceptibility to experimental autoimmune encephalomyelitis.

Previously we demonstrated that both myelin-specific and nonmyelin-specific rat T cells were capable of accelerating the development of transplanted rat BM-derived APC in the CNS of SCID C.B-17/scid (SCID) mice. This suggested that nonmyelin-specific T cells might be capable of increasing susceptibility to EAE by increasing the number and function of APC in the CNS before disease induction. To assess this possibility, we evaluated disease incidence, day of onset, duration, mean peak severity, cumulative disease index, and histopathology in the presence or absence of nonmyelin-specific T cells. The results demonstrate an association between T cell responses to nonmyelin Ags, accelerated development of BM-derived CNS APC before disease induction, and heightened susceptibility to CNS inflammation mediated by myelin-specific T cells. This suggests that T cell responses to nonmyelin Ags can potentiate CNS inflammation by elevating the functional presence of CNS APC.

Animals↗
PubMed2002

Cognitive dysfunction in multiple sclerosis: natural history, pathophysiology and management.

Cognitive dysfunction is a major cause of disability in patients with multiple sclerosis (MS). The prevalence of cognitive dysfunction is estimated at 45 to 65%. Natural history studies suggest that once cognitive dysfunction develops in a patient with MS, it is not likely to remit. Unlike physical disability in MS, cognitive disability correlates weakly with T2 lesion burden on brain magnetic resonance imaging (MRI). More robust correlations exist with magnetisation transfer imaging and MRI measures of brain atrophy. Patients with MS who have cognitive impairment most commonly display deficits in the cognitive domains of memory, learning, attention and information processing. In diagnosing cognitive dysfunction in a patient with MS, it is important first to recognise and treat the common comorbidities of fatigue and depression. The first step in the treatment of cognitive dysfunction is to delay disease progression, and there are currently five such disease-modifying agents approved for the treatment of MS (two preparations of interferon-beta-1a, interferon-beta-1b, glatiramer acetate and mitoxantrone). Nonpharmacological measures, such as cognitive rehabilitation, occupational therapy and psychotherapy, are the mainstays of symptomatic treatment. Pharmacological symptomatic therapy centres on the treatment of comorbid fatigue and depression. There are currently no effective pharmacological agents approved as symptomatic therapy of cognitive dysfunction in MS.

Adjuvants, Immunologic↗