Effect of peeling, cutting, or shredding of lettuce, carrot, or potato on the efficacy of chlorine disinfection.

Minimally processed vegetables are washed and subsequently disinfected by immersion in water solutions with antimicrobials which reduce the initial pathogenic or spoilage microbial load. Chlorine remains one of the most widely used disinfectants for vegetables and hence the importance of studying its properties. The aim of this study was to evaluate the effect of peeling, cutting, and shredding on the effectiveness of chlorine (200 ppm) as a disinfectant in lettuce, carrot, and potato.

Role of CRF1 receptor in post-incisional plasma extravasation and nociceptive responses in mice.

The corticotropin-releasing factor (CRF) is involved in a number of physiological functions including pain perception. The purpose of this study was to evaluate the role of CRF1 receptor in the long-lasting post-surgical changes in somatic nociceptive thresholds and in local inflammatory responses, using genetically engineered mice lacking functional CRF1 receptor. Animals underwent a plantar incision under anaesthesia with remifentanil (80μg/kg s.

Antihyperalgesic effects of dexketoprofen and tramadol in a model of postoperative pain in mice - effects on glial cell activation.

Objectives: To define likely targets (i.e. glia) and protocols (analgesic combinations) to improve postoperative pain outcomes and reduce chronic pain after surgery.

Glial cell activation in the spinal cord and dorsal root ganglia induced by surgery in mice.

In rodents, surgery and/or remifentanil induce postoperative pain hypersensitivity together with glial cell activation. The same stimulus also produces long-lasting adaptative changes resulting in latent pain sensitization, substantiated after naloxone administration. Glial contribution to postoperative latent sensitization is unknown.

A ¹⁸F-fluorodeoxyglucose MicroPET imaging study to assess changes in brain glucose metabolism in a rat model of surgery-induced latent pain sensitization.

Background: Neuroplastic changes involved in latent pain sensitization after surgery are poorly defined. We assessed temporal changes in glucose brain metabolism in a postoperative rat model using positron emission tomography. We also investigated brain metabolism after naloxone administration.

Delayed postoperative latent pain sensitization revealed by the systemic administration of opioid antagonists in mice.

The long-lasting post-surgical changes in nociceptive thresholds in mice, indicative of latent pain sensitization, were studied. The contribution of kappa opioid and N-methyl-d-aspartate (NMDA) receptors was assessed by the administration of nor-binaltorphimine or MK-801; dynorphin levels in the spinal cord were also determined. Animals underwent a plantar incision and/or a subcutaneous infusion of remifentanil (80μg/kg), and mechanical thresholds (von Frey) were evaluated at different times.

Antinociceptive effects of morphine, fentanyl, tramadol and their combination, in morphine-tolerant mice.

The development of morphine-tolerance after chronic administration, reduces analgesic efficacy and is a significant clinical problem in some patients; may be managed clinically by increasing the doses of morphine and/or the administration of a second mu-opioid agonist. In morphine-tolerant mice, we investigated the presence of an interaction when two opioids are administered simultaneously. We determined the antinociceptive effects of morphine (M), fentanyl (FEN), and tramadol (TRM) individually and combined in a 1:1 proportion, based on their potency.

Analysis of the opioid-opioid combinations according to the nociceptive stimulus in mice.

The purpose of the present study was to characterize the antinociceptive effects of tramadol, fentanyl and morphine, when two of them were systemically combined in a 1:1 potency ratio, in the hot plate, the acetic acid writhing, and the formalin tests in mice. Interaction indexes and isobolographic analysis were used to assess the type of interaction. Fentanyl was the most potent drug, followed by morphine and tramadol, with the exception in the phase I of formalin test.

Pronociceptive effects of remifentanil in a mouse model of postsurgical pain: effect of a second surgery.

Background: Remifentanil anesthesia enhances postoperative pain in animals and humans. The authors evaluated the impact of the dose (microg x kg(-1) x min(-1)) and duration of remifentanil infusion, and the effects of a second surgery on postoperative pain sensitization.

Methods: Mice received different doses of remifentanil over 30 or 60 min.

Increased spinal dynorphin levels and phospho-extracellular signal-regulated kinases 1 and 2 and c-Fos immunoreactivity after surgery under remifentanil anesthesia in mice.

In humans, remifentanil anesthesia enhances nociceptive sensitization in the postoperative period. We hypothesized that activation of extracellular signal-regulated kinases 1 and 2 (ERK1/2) and the expression of c-Fos, prodynorphin (mRNA), and dynorphin in the spinal cord could participate in the molecular mechanisms underlying postoperative opioid-induced sensitization. In a mouse model of incisional pain, we evaluated thermal (Hargreaves test) and mechanical (von Frey) hyperalgesia during the first 21 postoperative days.

Deletion of the inducible nitric oxide synthase gene reduces peripheral morphine tolerance in a mouse model of chronic inflammation.

The implication of inducible nitric-oxide synthase (iNOS) on peripheral tolerance to morphine was evaluated in wild-type (WT) and iNOS knockout mice. Chronic inflammation was induced by subplantar (s.p.

Tolerance to the antinociceptive effects of peripherally administered opioids. Expression of beta-arrestins.

Tolerance to peripheral antinociception after chronic exposure to systemic morphine was assessed in mice with chronic CFA-inflammation; cross-tolerance to locally administered mu, delta and kappa-opioid agonists and levels of beta-arrestins in the injured paw, were also evaluated. Tolerance was induced by the subcutaneous implantation of a 75 mg morphine-pellet, and antinociception evaluated with the Randall-Selitto test, 5 min after the subplantar injection of morphine, fentanyl, buprenorphine, DPDPE, U-50488H or CRF. Experiments were performed in the absence and presence of CFA-inflammation, in animals implanted with a morphine or placebo pellet.

Effects of chronic inflammation and morphine tolerance on the expression of phospho-ERK 1/2 and phospho-P38 in the injured tissue.

Opioids are used in humans in the treatment of chronic osteoarticular pain, but the development of tolerance to the analgesic effects after continuous administration is still not well understood. The aim of the present study was to evaluate the expression of phospho-ERK 1/2 and phospho-p38 in mice with monoarthritis chronically exposed to morphine as a possible explanation for the development of tolerance. Inflammation was induced by intraplantar injection of complete Freund's adjuvant (CFA) and the tolerance by implantation of 75 mg morphine pellets.

Anti-exudative effects of opioid receptor agonists in a rat model of carrageenan-induced acute inflammation of the paw.

We evaluated the anti-exudative effects (Evan's blue) of mu-, delta- and kappa-opioid receptor agonists in a rat model of carrageenan-induced acute inflammation. The contribution of different components was assessed after the administration of: cyclosporine A, capsaicin, 6-hydroxydopamine, compound 48/80, and specific histamine-receptor antagonists. The results show that the mu-opioid receptor agonists morphine and fentanyl and the delta-opioid receptor agonists DPDPE (enkephalin, [D-Pen(2,5)]) and SNC 80 ((+)-4-[(alpha R)-alpha((2S,5R)-4-allyl-2,5-dimethyl-1-piperazinyl)-3-methoxybenzyl]-N,N diethylbenzamide) decrease plasma extravasation in a dose-dependent manner, with a biphasic response.

Non-steroidal anti-inflammatory drugs antagonise the constipating effects of tramadol.

We report an antagonistic interaction between tramadol and non-steroidal anti-inflammatory drugs (NSAIDs), on gastrointestinal transit in rats. Transit was evaluated with charcoal and results are expressed as %inhibition. Tramadol and morphine had ED(50)s of 120.

Interaction between metamizol and tramadol in a model of acute visceral pain in rats.

Tramadol (TRM) and metamizol (MTZ) are drugs with complex mechanisms of action, extensively used in combination in pain management. In the present investigation we have evaluated the interaction between MTZ:TRM in the ethacrinic acid writhing test in rats. Dose-response curves (s.