Nimesulide 90 mg orally twice daily does not influence postoperative morphine requirements after major chest surgery.

BACKGROUND: Cyclooxygenase 2 inhibition has proven analgesic efficacy in a variety of surgical procedures. We postulated that perioperative cyclooxygenase 2 inhibition significantly reduces postoperative morphine requirements after major thoracic surgery and investigated the site of this potential analgesic effect. METHODS: Ninety-two patients participated in this single-center, double-blind, randomized, placebo-controlled, parallel-group trial. Patients between the ages of 18 and 80 yr undergoing a thoracotomy or median sternotomy were randomized to receive either nimesulide or placebo in combination with a standard analgesic regimen perioperatively. Nimesulide was administered orally the evening before surgery and at 12-h intervals for 5 days postoperatively. The primary efficacy variables were morphine consumption and pain scores for the first 48 h postoperatively. The secondary efficacy variable was the effect of nimesulide on cyclooxygenase activity in cerebrospinal fluid (CSF). RESULTS: Pain scores at rest or with movement, and total morphine consumption for the first 48 h postoperatively, were not statistically different between the groups. The mean difference in total morphine consumption up to 48 h postoperatively between the nimesulide and placebo group was a 9.0 mg reduction (95% CI: -28.9 to 10.9 mg) (P = 0.37). Adjusted mean (se) CSF 6-keto-PGF1alpha (6-keto-PGF1alpha) concentrations increased by 54.7 (25.7) pg/mL from preoperatively to Day + 2 postoperatively in the placebo group, whereas adjusted mean (se) CSF 6-keto-PGF1alpha concentration decreased by 0.6 pg/mL (18.2 pg/mL) in the nimesulide group. These changes were not statistically different between the groups (P = 0.095). CONCLUSION: Nimesulide, at a dose of 90 mg twice daily in combination with a standard analgesic regimen, does not influence pain scores, morphine requirements, or CSF prostaglandin levels after major thoracic surgery.

Cyclo-oxygenases and prostaglandins in acute inflammatory demyelination of the peripheral nerve.

OBJECTIVE: To investigate the expression of cyclo-oxygenases (COX), key enzymes in propagating inflammatory responses by converting arachidonic acid to prostaglandins, in inflammatory demyelinating disorders of the peripheral nervous system (PNS). METHODS: Expression and distribution of COX messenger RNA (mRNA) and protein were studied in sural nerve biopsies, serum, and CSF samples from patients with Guillain-Barré syndrome (GBS), chronic inflammatory demyelinating polyradiculoneuropathy (CIDP), or, for comparison, with vasculitic neuropathy (VN), which is a inflammatory nondemyelinating disorder, and noninflammatory neuropathies (NIN) using RT-PCR, immunohistochemistry, and immunoblotting. To confirm functional COX-2 activity, the expression of prostaglandin E(2) (PGE(2)) and prostaglandin F(2alpha) (PGF(2alpha)) was evaluated by ELISA ex vivo and in vitro. RESULTS: Whereas COX-1 expression was unaltered in all investigated groups, a significant upregulation of COX-2 mRNA was detected in sural nerves from patients with GBS, CIDP, or VN but not in control subjects with noninflammatory disorders. Macrophages were identified as its primary cellular source. Increased COX-2 protein levels were detectable in serum and CSF from all patients with GBS and, in smaller numbers only, in samples from patients with CIDP or VN but not from the NIN group studied. Moreover, increased levels of PGE(2) and PGF(2alpha) were measurable in sera from patients with GBS, CIDP, or VN and in cell culture supernatants from in vitro stimulated macrophages, indicative of COX-2 activity. CONCLUSIONS: Cyclo-oxygenase-2, expressed by macrophages, may generate prostaglandins during acute inflammatory demyelination of the peripheral nerve.

Attenuated fever in pregnant rats is associated with blunted syntheses of brain cyclooxygenase-2 and PGE2.

Attenuation of fever occurs in pregnant animals. This study examined a hypothesis that brain production of PGE(2), the final mediator of fever, is suppressed in pregnant animals. Near-term pregnant rats and age-matched nonpregnant female rats were injected with lipopolysaccharide (100 microg/kg) intraperitoneally. Four hours later, colonic temperature was measured, their cerebrospinal fluid (CSF) was sampled for PGE(2) assay, and their brains were processed for immunohistochemistry of cyclooxygenase-2, an enzyme involved in PGE(2) biosynthesis. In the pregnant rats, lipopolysaccharide injection resulted in significantly smaller elevations in both colonic temperature and CSF-PGE(2) level than in nonpregnant rats. In the pregnant rats, lipopolysaccharide-induced cyclooxygenase-2 expression was blunted in terms of the number of positive cells. There was a significant correlation between PGE(2) level in CSF and the number of cyclooxygenase-2-positive endothelial cells. These results suggest that suppressed PGE(2) production in the brain is one cause for the attenuated fever response at near-term pregnancy and that this suppressed PGE(2) production is due to the suppressed induction of cyclooxygenase-2 in brain endothelial cells.

Elevated spinal cyclooxygenase and prostaglandin release during hyperalgesia in diabetic rats.

Diabetic rats display exaggerated hyperalgesic behavior in response to noxious stimuli that may model aspects of painful diabetic neuropathy. This study examined the contribution of spinal prostaglandin production to this exaggerated hyperalgesic behavior. Rats were implanted with spinal dialysis probes and received noxious stimulation to the hind paw by subcutaneous injection of 0.5% formalin solution. Prostaglandin E(2) (PGE(2)) was measured in dialysates of lumbar spinal cerebrospinal fluid concurrent with behavioral responses to formalin injection. In separate experiments, formalin-evoked behavioral responses were measured after intrathecal delivery of either a cyclooxygenase inhibitor or an EP(1) receptor antagonist, and cyclooxygenase protein was measured in spinal cord homogenates. Diabetic rats exhibited exaggerated behavioral responses to paw formalin injection and a concurrent prolongation of formalin-evoked PGE(2) release. Formalin-evoked behavioral responses were dose-dependently reduced in diabetic rats by spinal delivery of a cyclooxygenase inhibitor or an EP(1) receptor antagonist. Protein levels of cyclooxygenase-2 were elevated in the spinal cord of diabetic rats, whereas cyclooxygenase-1 protein was reduced. Hyperalgesic behavior in diabetic rats is associated with both increased cyclooxygenase-2 protein and cyclooxygenase-mediated PGE(2) release. Spinal delivery of selective inhibitors of cyclooxygenase-2 or antagonists of prostaglandin receptors may have therapeutic potential for treating painful diabetic neuropathy.

Elevated CSF prostaglandin E2 levels in patients with probable AD.

OBJECTIVE: To determine CSF eicosanoid concentrations and brain cyclo-oxygenase activity in AD patients and age-matched control subjects. BACKGROUND: Nonsteroidal anti-inflammatory drugs may benefit AD patients by inhibiting cyclo-oxygenases and thereby reducing prostaglandin (PG) production or oxidant stress in the CNS. METHODS: CSF eicosanoid and F2-isoprostane (IsoP) levels were determined in seven probable AD patients and seven age-matched control subjects. Cyclo-oxygenase activity was determined in microsomes prepared from the hippocampus of 10 definite AD patients and 8 age-matched control subjects. All measurements were made using gas chromatography/mass spectrometry. RESULTS: CSF concentrations of prostaglandin (PG) E2 were increased fivefold (p < 0.01) and 6-keto-PGF1alpha was decreased fourfold (p < 0.01) in probable AD patients. There was no change in total CSF eicosanoid concentration in probable AD patients. CSF F2-IsoP, a quantitative marker of lipid peroxidation in vivo, was increased in probable AD patients (p < 0.05). Cyclo-oxygenase activity in the hippocampus from definite AD patients was not different from age-matched control subjects. CONCLUSIONS: These data suggest that cyclo-oxygenase activity may not contribute significantly to CNS oxidative damage in AD. Increased CSF PGE2 concentration in probable AD patients suggest that cyclo-oxygenase inhibitors may benefit AD patients by limiting PG production.

[Beta trace protein in the cerebrospinal fluid and serum in meningoencephalitis]. / Proteína beta traza en líquido cefalorraquídeo y suero en meningoencefalitis.

INTRODUCTION: beta-trace protein or D2 prostaglandin synthase is a dual functional protein. Its role and clinical value in cerebrospinal fluid is under study. MATERIAL AND METHODS: Seventy four pediatric patients suffering from viral meningoencephalitis and 7 with bacterial meningoencephalitis were studied. Sera and cerebrospinal fluid samples were taken. Albumin and beta-trace protein were quantified by immunodiffusion and nephelometry respectively. RESULTS: Increased cerebrospinal fluid beta-trace protein levels in comparison with normal value were observed. Nevertheless such expected increment was no possible seen in bacterial meningoencephalitis. CONCLUSIONS: beta-trace protein may contribute with the etiological diagnosis in meningoencephalitis.