Search results for "Nociception"
showing 10 items of 110 documents
Opioid Poorly-Responsive Cancer Pain. Part 1
2001
Pain that is poorly responsive to opioid analgesics is challenging for physicians who deal with cancer patients. Numerous factors may influence analgesic response during the course of the illness. These include changing nociception associated with disease progression, the appearance of intractable side effects, the development of tolerance, the presence of neuropathic pain, the temporal pattern, the effects produced by the production of opioid metabolites, and many others. These factors influence the delicate balance between pain relief and opioid toxicity that must be achieved in cancer patients with pain.
Characteristic intraepidermal nerve fibre endings of the intervibrissal fur in the mystacial pad of the rat: morphological details revealed by intrav…
1999
Light microscopic observations employing intravital methylene blue staining and impregnation by the zinc iodide-osmium tetroxide technique are presented for intraepidermal nerve fibre endings of the intervibrissal fur in the mystacial pad of the rat snout. Both procedures revealed anatomical details of the intraepidermal nerve fibre plexus in epidermal hillocks often located very close to the mouths of hairs. These nerve fibres appeared to resemble those described in previous immunohistochemical studies as cluster or bush endings. The methylene blue preparations demonstrated the existence of an intensely stained enlargement at the site of the branching point of the nerve fibres which seemed…
Pharmacological studies of 1-(p-chlorophenyl)propanol and 2-(1-hydroxy-3-butenyl)phenol: Two new non-narcotic analgesics designed by molecular connec…
1997
Abstract Molecular topology has been applied to the design of new analgesic drugs. Linear discriminant analysis and connectivity functions were used to design two potentially suitable drugs which were synthesized and tested for analgesic properties by the acetic acid-induced abdominal constriction test in mice and the tail-flick test in rats. In mice, the compound 1-(p-chlorophenyl)propanol showed higher analgesic activity, both intraperitoneally and orally, than acetylsalicylic acid. 2-(1-Hydroxy-3-butenyl)phenol exhibited a lesser protective effect (70% of that shown by acetylsalicylic acid). In rats, acetylsalicylic acid gave the greatest protection against pain when administered intrape…
Convergence of nociceptive and non-nociceptive inputs onto spinal reflex pathways to the tibialis anterior muscle in humans
1998
The interaction of low-threshold mechanoreceptive and nociceptive inputs onto spinal neurones probably plays a major role in the pathophysiology of the clinical sign of allodynia. This phenomenon was investigated by modulation of the early component of the flexor reflex (FR) in the tibialis anterior (TA) muscle, elicited by electrical stimulation of the medial plantar nerve at the sole of the foot, by homotopically applied painful heat in humans. This early reflex with an electrical threshold of 2.7-fold the detection threshold and a mean afferent conduction velocity of 49 m s-1 is a non-nociceptive FR. When applying conditioning painful heat (46 degrees C) to the sole of the foot this refl…
Revising the negative meaning of chronic pain : A phenomenological study
2014
Objectives Chronic pain may disable the body, depress the mind and ruin the quality of life. The aim of this study was to use the participants’ personal experiences to explore the meaning of the experience of chronic pain and to find successful ways to manage chronic pain. Methods Thirty-four participants with chronic pain were interviewed. The transcribed interviews were analysed using Giorgi’s phenomenological method consisting of four phases: (1) reading the transcriptions several times, (2) discriminating meaning units, (3) collecting meaning units into groups and (4) the synthesis. Results The participants stated that the key to managing chronic pain was to reconsider the individual me…
Neurophysiological studies of pain pathways in peripheral and central nervous system disorders.
2003
Standard clinical neurophysiological assessment of somatosensory pathways by sensory evoked potentials (SEPs) is limited to the tactile and proprioceptive systems consisting of large fibers in the peripheral nerve, the dorsal columns of the spinal cord and the medial lemniscus in the brainstem. This limitation means that about half of the lesions in the somatosensory system will not be detectable. In recent years, many clinical studies have confirmed that laser evoked potentials (LEPs) allow the assessment of the other half of the somatosensory system. Rapid heating of the skin by infrared laser pulses specifically activates the nociceptive and thermoreceptive pathways consisting of small f…
“THERMAL NOCICEPTION STUDIES IN ZEBRAFISH”
2012
Background Nociception was defined by Sherrington as the mechanism used to sense painful events. Despite the value of current animal models for nociception and pain, we have not yet understood in full how these mechanisms operate. Aim Here we propose a novel approach using zebrafish (Danio rerio) larvae in order to determine if the fish is suitable for the study of pain stimuli. Taking advantage of the fact that, in response to noxious stimuli, the expression of several genes in mammals is induced in neurons of the spinal cord and the dorsal root ganglia (DRG), we investigated if such mechanism is evolutionary conserved in the Zebrafish. Materials and Methods We cloned homologues of mammals…
Mechanisms of neuropathic pain and their importance in Fabry disease
2007
UNLABELLED One of the most prominent features of Fabry disease is neuropathic pain. Neuropathic pain occurs after neuronal damage. In contrast to inflammatory or trauma-related pain, which normally helps to maintain or restore body functions, neuropathic pain tends to become chronic, and must therefore be considered a 'pathological' pain. Neuropathic pain has usually been classified according to the aetiology of nerve damage: traumatic, inflammatory, cancer-related or metabolic (e.g. Fabry disease). However, use of this classification often results in inadequate therapy for neuropathic pain. Recent research has revealed distinct mechanisms that are responsible for neuropathic pain. These me…
Association between pain, central sensitization and anxiety in postherpetic neuralgia
2014
Background In postherpetic neuralgia (PHN), dorsal root ganglia neurons are damaged. According to the proposed models, PHN pain might be associated with nociceptive deafferentation, and peripheral (heat hyperalgesia) or central sensitization (allodynia). Methods In 36 PHN patients, afferent nerve fibre function was characterized using quantitative sensory testing and histamine-induced flare analysis. Psychological factors were evaluated with the Hospital Anxiety and Depression Scale (HADS), disease-related quality of life (QoL) with SF-36 and pain with the McGill questionnaire [pain rating index (PRI)]. The patients were also divided into subgroups according to the presence or absence of br…
ChemInform Abstract: 2-Sulfonyliminodihydropyrimidines: A Novel Class of Analgesic Compounds.
2009
A series of 2-sulfonyliminodihydropyrimidine derivatives have been synthesized and evaluated in vivo for their antinociceptive and anti-inflammatory activities. The results were compared with that of acetyl salicylic acid. Compounds 6Ab-d and 6Be displayed an interesting analgesic profile in the acetic acid-induced abdominal contractions test. Based on the results of the carrageenan-hind paw edema test, compound 6Af showed potential anti-inflammatory activity.