Journal of dental research
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The activation of excitatory amino acid (EAA) receptors within the central nervous system is associated with numerous centrally mediated phenomena, including hyperalgesia. However, relatively little is known about the peripheral mechanisms which these receptors may regulate when activated. This research evaluated the hypothesis that EAA receptors in bovine dental pulp activate a population of peptidergic sensory neurons as measured by the release of immunoreactive calcitonin gene-related peptide (iCGRP), a neuropeptide associated with neurogenic inflammation. ⋯ Pre-treatment and co-administration of the AMPA/kainate receptor antagonist CNQX significantly reduced the iCGRP release evoked by either of these agonists. In contrast, neither NMDA nor L-glutamate induced any consistent changes in iCGRP release. These results suggest that the activation of AMPA and kainate receptors in dental pulp may contribute to peripheral release of vasoactive neuropeptides which mediate a neurogenic component of inflammation.
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Biography Historical Article
Carl Koller: mankind's greatest benefactor? The story of local anesthesia.
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In this study, we investigated whether selective activation of nociceptive primary afferent fibers by capsaicin would induce modulations on tooth-pulp-evoked sensory or inhibitory masseter reflex responses in healthy human subjects. The contribution of central N-methyl-D-aspartate (NMDA) receptor mechanisms in capsaicin-induced effects on sensory or reflex responses was evaluated by dextromethorphan, an NMDA-receptor antagonist. The inhibitory masseter reflex was evoked by electrical stimulation (constant current, single pulses) of the upper incisor while the subject was biting at 10% of his maximal force. ⋯ These data indicate that noxious stimulation of the facial skin by capsaicin induces differential effects on tooth-pulp-evoked sensory and inhibitory masseter reflex responses: Sensory responses are strongly attenuated, while masseter reflex responses are not significantly changed. Dextromethorphan at a clinically applicable dose does not influence tooth-pulp-evoked sensory or reflex responses or their modulation by capsaicin. Furthermore, the lack of modulation of the masseter reflex response by capsaicin differs from the capsaicin-induced enhancement of a nocifensive limb flexion reflex described earlier.
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The presence of oral smokeless tobacco lesions among adolescents may be an early indicator of increased risk for oral cancers. Data from the 1986-1987 National Survey of Oral Health in US School Children were used to examine the cross-sectional relationship between the use of tobacco and alcohol and the presence of white or whitish oral soft-tissue lesions. The sample included 17,027 schoolchildren (aged 12 to 17 years) who provided information on the use of snuff, chewing tobacco, cigarettes, and alcohol and who received oral clinical examinations. ⋯ These data suggest that snuff may be a stronger risk factor than chewing tobacco for smokeless tobacco lesions, but the use of either of these forms of oral tobacco exhibits a dose-response relationship with the occurrence of lesions. We found little evidence that the use of alcohol or cigarettes may increase the risk of smokeless tobacco lesions. Preventing smokeless tobacco lesions and their possible malignant transformation may be best accomplished among adolescents by preventing the use of snuff and chewing tobacco.