Is dental treatment of an infected tooth a risk factor for locally invasive spread of infection?

Purpose: To determine the impact of antecedent dental procedures and dental health on the course of odontogenic maxillofacial infections requiring hospital care.

Patients And Methods: In this retrospective cohort study in a referral center, we evaluated medical records and panoramic radiographs of all patients admitted because of odontogenic maxillofacial infection (n = 84). The predictor variables were preceding dental treatment, antimicrobial therapy, and dental health.

Stress-induced analgesia and morphine responses are changed in catechol-O-methyltransferase-deficient male mice.

Catechol-O-methyltransferase (COMT) polymorphisms modulate pain and opioid analgesia in human beings. It is not clear how the effects of COMT are mediated and only few relevant animal studies have been performed. Here, we used old male Comt gene knock-out mice as an animal model to study the effects of COMT deficiency on nociception that was assessed by the hot plate and tail flick tests.

Pharmacological characterization of noroxymorphone as a new opioid for spinal analgesia.

Background: Noroxymorphone is one of the major metabolites of oxycodone. Although oxycodone is commonly used in the treatment of acute and chronic pain, little is known about the antinociceptive effects of noroxymorphone. We present an in vivo pharmacological characterization of noroxymorphone in rats.

Antinociception by spinal and systemic oxycodone: why does the route make a difference? In vitro and in vivo studies in rats.

Background: The pharmacology of oxycodone is poorly understood despite its growing clinical use. The discrepancy between its good clinical effectiveness after systemic administration and the loss of potency after spinal administration led the authors to study the pharmacodynamic effects of oxycodone and its metabolites using in vivo and in vitro models in rats.

Methods: Male Sprague-Dawley rats were used in hot-plate, tail-flick, and paw-pressure tests to study the antinociceptive properties of morphine, oxycodone, and its metabolites oxymorphone and noroxycodone.

Morphine, oxycodone, methadone and its enantiomers in different models of nociception in the rat.

We studied the effects of the commonly used mu-opioid receptor agonists morphine, oxycodone, methadone and the enantiomers of methadone in thermal and mechanical models of acute pain and in the spinal nerve ligation model of neuropathic pain in rats. Subcutaneous administration of morphine, oxycodone, and methadone produced a dose-dependent antinociceptive effect in the tail flick, hotplate, and paw pressure tests. l-methadone, racemic methadone, and oxycodone had a similar dose-dependent antinociceptive effect, whereas the dose-response curve of morphine was shallower.

Pain- and morphine-associated transcriptional regulation of neuropeptide FF and the G-protein-coupled NPFF2 receptor gene.

Neuropeptide FF (NPFF) is involved in pain modulation, especially plasticity during inflammatory and neuropathic pain, and opiate interactions. Its nociceptive functions may be mediated by the NPFF2 receptor. To elucidate the role of the NPFF system in plasticity associated with pathologic pain, we studied the changes of NPFF mRNA and NPFF2 receptor mRNA in rat models of acute colonic inflammation, inflammatory pain, and neuropathic pain.