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Tolerance Threshold (tolerance + threshold)
Kinds of Tolerance Threshold Selected Abstracts(613) Radiculopathy Treatment Assessment Using Pain Tolerance TestPAIN MEDICINE, Issue 2 2000Article first published online: 25 DEC 200 Authors: Y. Eugene Mironer, Carolinas Center for Advanced Management of Pain; Judson J. Somerville, The Pain Management Clinic of Laredo Current measurements of the outcomes of chronic radiculopathy treatment are limited to subjective criteria: level of pain, range of motion, etc. Our previous study showed that nerve conductivity does not correlate well with the intensity of pain after treatment of radiculopathy (1). In the current study we looked at the Pain Tolerance Threshold (PTT) as a possible measurement of the results of radiculopathy treatment. Twenty patients with chronic radiculopathy (13 lumbar and 7 cervical) underwent epidural steroid injections at the level of involvement. Before, and approximately one week after the procedure, we measured PTT in both the involved and contralateral extremity at 3 different frequencies (5Hz, 250Hz, and 2000 Hz) using Neurometer. Level of pain was also assessed using a Visual Analog Scale (VAS). Initial PTT results showed great interpersonal variability. Nearly half of the patients did not show significant differences in PTT between affected and unaffected sides. Of interest, the majority experienced intolerable pain at 2000 Hz stimulation at lower than maximal intensity output, which contradicts previous findings (2). Dynamics of the PTT measurements after treatment did not directly correlate with changes in the level of pain. Nevertheless, in 7 out of 8 patients with low PTT (relative to the unaffected side) it increased significantly, with noticeable decrease of VAS score. Similar results were not found in patients with either normal initial PTT score or minimal improvement of pain. 1. Mironer YE, Somerville JJ The current perception threshold evaluation in radiculopathy: efficacy in diagnosis and assessment of treatment results. Pain Digest 1998;8:37,38. 2. Liu SS, Gerancher JC, Bainton BG, et al. The effects of electrical stimulation at different frequencies on perception and pain in human volunteers: epidural versus intravenous administration of fentanyl. Anesth Analg 1996;82:98,102. [source] The Role of Central Hypersensitivity in the Determination of Intradiscal Mechanical Hyperalgesia in Discogenic PainPAIN MEDICINE, Issue 5 2010Juerg Schliessbach PhD Abstract Objective., The primary aim of the present study was to investigate whether there is a relationship between central hypersensitivity (assessed by pressure pain thresholds of uninjured tissues) and intradiscal pain threshold during discography. The secondary aim was to test the hypothesis that peripheral noxious stimulation dynamically modulates central hypersensitivity. Patients., Twenty-four patients with positive provocation discography were tested for central hypersensitivity by pressure algometry before and after the intervention with assessments of pressure pain detection and tolerance thresholds. Intradiscal pain threshold was assessed by measuring intradiscal pressure at the moment of pain provocation during discography. Correlation analyses between intradiscal pain threshold and pressure algometry were made. For the secondary aim, pressure algometry data before and after discography were compared. Results., Significant correlation with intradiscal pain threshold was found for pressure pain detection threshold at the toe (regression coefficient: 0.03, P = 0.05) and pressure pain tolerance thresholds at the nonpainful point at the back (0.02, P = 0.024). Tolerance threshold at the toe was a significant predictor for intradiscal pain threshold only in multiple linear regression (0.036, P = 0.027). Detection as well as tolerance thresholds significantly decreased after discography at the painful and the nonpainful point at the back, but not at the toe. Conclusions., Central hypersensitivity may influence intradiscal pain threshold, but with a modest quantitative impact. The diagnostic value of provocation discography is therefore not substantially impaired. Regional, but not generalized central hypersensitivity is dynamically modulated by ongoing peripheral nociceptive input. [source] Elevation and forest clearing effects on foraging differ between surface , and subterranean , foraging army ants (Formicidae: Ecitoninae)JOURNAL OF ANIMAL ECOLOGY, Issue 1 2009Anjali Kumar Summary 1Forest fragmentation often results in a matrix of open areas mixed with patches of forest. Both biotic and abiotic factors can affect consumer species' ability to utilize the altered habitat, especially for species that range over large areas searching for prey. 2Army ants (Formicidae: Ecitoninae) are highly mobile top predators in terrestrial Neotropical ecosystems. Army ant foraging behaviour is influenced by forest clearing at lowland sites, and clearing can reduce army ant population persistence. 3Because high temperatures are implicated in hindering above-ground army ant foraging, we predicted that forest clearing effects on army ant foraging would be reduced at higher (cooler) elevations in montane forest. We also predicted that subterranean foraging, employed by some army ant species, would buffer them from the negative effects of forest clearing. 4We quantified the foraging rates of above-ground and underground foraging army ants at eight sites along an elevational gradient from 1090 to 1540 m a.s.l. We asked whether these two foraging strategies cause a difference in the ability of army ants to forage in open matrix areas relative to elevationally matched forested habitats, and whether elevation predicts open area vs. forest foraging rate differences. 5As predicted, army ants that forage above-ground had lower foraging rates in open areas, but the open area vs. forest difference declined with elevation. In contrast, underground foragers were not affected by habitat type, and underground foraging rates increased with elevation. Ground surface temperatures were higher in open areas than forested areas. Temperatures declined with elevation, and temperature differences between open and forested areas decreased with elevation. 6We conclude that army ants that forage above-ground may be restricted to forested areas due to a thermal tolerance threshold, but that they are released from this limitation at higher elevations. We further suggest that underground foraging permits some army ants to persist within modified landscapes. Our findings have implications for the effects of habitat modification and climate change on these top predators. [source] Impact of hot water treatment on sprouting, membrane permeability, sugar content and chip colour of reconditioned potato tubers following long-term cold storageJOURNAL OF THE SCIENCE OF FOOD AND AGRICULTURE, Issue 15 2008Marios C Kyriacou Abstract BACKGROUND: The efficacy of hot water treatment in facilitating successful reconditioning of processing potato (Solanum tuberosum L.) cultivar Hermes following 6 months cold storage at 4.5 °C was examined. Tubers were subjected to hot water treatments (HWTs) at 52.5, 55.0, 57.5 and 60.0 °C for 0,60, 0,50, 0,40 and 0,20 min, respectively, and then reconditioned for 20 days at 16 °C before evaluated for sprouting, fresh weight loss, membrane permeability, sugar content and processing quality. RESULTS: The study demonstrates that in order to achieve complete inhibition of sprouting during potato reconditioning HWTs must exceed the thermal tolerance threshold of the tubers. Short-duration HWT was effective in retarding sprout growth and tuber dehydration without significantly affecting storage parenchyma membrane permeability, tuber sugar content or processing quality. On the contrary, prolonged HWT caused extensive heat damage, loss of membrane integrity and induced an increase in tuber sucrose and reducing sugar content resulting in deterioration of chip colour in proportion to treatment duration. CONCLUSION: Although HWT at 52.5,60 °C following long-term cold storage did not improve the processing quality of potato tubers after 20 days of reconditioning, future work is needed to evaluate the effect of short-duration HWT on the permissible extent of reconditioning and subsequent processing quality. Copyright © 2008 Society of Chemical Industry [source] Detection of Staphylococcus aureus and enterotoxin genotype diversity in Monte Veronese, a Protected Designation of Origin Italian cheeseLETTERS IN APPLIED MICROBIOLOGY, Issue 5 2007A. Poli Abstract Aims:, To evaluate the risk associated with the load and enterotoxigenicity of Staphylococcus aureus in Monte Veronese, a PDO (Protected Designation of Origin) cheese of the Lessinia area (Verona, Italy). Methods and Results:,Staphylococcus aureus was quantified by a conventional culture method and by a nucA targeted real-time PCR assay developed in this study. Staphylococcus aureus numbers in cheese were higher than the limit tolerated by the Italian food legislation in 78% instances, according to both detection methods. Multiplex PCR tests for 17 Staph. aureus enterotoxin (SE) genes were applied to nucleic acids extracted from curds, cheeses and Staph. aureus isolates. The SE gene diversity appeared reduced after ripening. The gene encoding SED was found most frequently in dairy samples and the enterotoxin genes ser, sed, seg and sem predominated in the isolates. Conclusions:, The occurrence of enterotoxigenic Staph. aureus strains with complex SE genotypes in this PDO cheese at numbers often exceeding the Italian tolerance threshold represents an important risk factor. Significance and Impact of the Study:, The high frequency of contamination of Monte Veronese PDO cheese and, expectedly, similar typical productions from raw milk, by enterotoxigenic Staph. aureus imposes a tighter hygienic control in the earlier manufacturing phases. [source] Association of human ,-opioid receptor gene polymorphism A118G with fentanyl analgesia consumption in Chinese gynaecological patientsANAESTHESIA, Issue 2 2010W. Zhang Summary One hundred and seventy-four Chinese gynaecology patients were studied for the impact of A118G polymorphism in the ,-opioid receptor gene (OPRM1) on pain sensitivity and postoperative fentanyl consumption. Pre-operatively, the pain threshold and pain tolerance threshold were measured using electrical stimulation. A118G polymorphism was genotyped using the polymerase chain reaction,restriction fragment length polymorphism method. Intravenous fentanyl patient-controlled analgesia provided postoperative pain management, assessed using a visual analogue scale and fentanyl consumed in the first 24 h after surgery was noted. We found the prevalence of G118 allele was 31.3%. The A118G polymorphism had a gene-dose-dependent effect on electrical pain tolerance threshold. Fentanyl consumption was also significantly different in patients with different OPRM1 genotypes (homozygotes for 118G consumed more than did heterozygotes or homozygotes for 118A). Fentanyl consumption increased in accordance with the number of 118G alleles. We conclude that OPRM1 gene analysis may help predict individual opioid sensitivity and so optimise postoperative pain control. [source] The Role of Central Hypersensitivity in the Determination of Intradiscal Mechanical Hyperalgesia in Discogenic PainPAIN MEDICINE, Issue 5 2010Juerg Schliessbach PhD Abstract Objective., The primary aim of the present study was to investigate whether there is a relationship between central hypersensitivity (assessed by pressure pain thresholds of uninjured tissues) and intradiscal pain threshold during discography. The secondary aim was to test the hypothesis that peripheral noxious stimulation dynamically modulates central hypersensitivity. Patients., Twenty-four patients with positive provocation discography were tested for central hypersensitivity by pressure algometry before and after the intervention with assessments of pressure pain detection and tolerance thresholds. Intradiscal pain threshold was assessed by measuring intradiscal pressure at the moment of pain provocation during discography. Correlation analyses between intradiscal pain threshold and pressure algometry were made. For the secondary aim, pressure algometry data before and after discography were compared. Results., Significant correlation with intradiscal pain threshold was found for pressure pain detection threshold at the toe (regression coefficient: 0.03, P = 0.05) and pressure pain tolerance thresholds at the nonpainful point at the back (0.02, P = 0.024). Tolerance threshold at the toe was a significant predictor for intradiscal pain threshold only in multiple linear regression (0.036, P = 0.027). Detection as well as tolerance thresholds significantly decreased after discography at the painful and the nonpainful point at the back, but not at the toe. Conclusions., Central hypersensitivity may influence intradiscal pain threshold, but with a modest quantitative impact. The diagnostic value of provocation discography is therefore not substantially impaired. Regional, but not generalized central hypersensitivity is dynamically modulated by ongoing peripheral nociceptive input. [source] Human head exposure to a 37 Hz electromagnetic field: Effects on blood pressure, somatosensory perception, and related parametersBIOELECTROMAGNETICS, Issue 3 2004Sergio Ghione Abstract Previous studies have shown that exposure to an electromagnetic field (EMF) of 37 Hz at a flux density of 80 ,T peak enhances nociceptive sensitivity in mice. Here we examined the effects on pain sensitivity and some indexes of cardiovascular regulation mechanisms in humans by measuring electrical cutaneous thresholds, arterial blood pressure, heart rate and its variability, and stress hormones. Pain and tolerance thresholds remained unchanged after sham exposure but significantly decreased after electromagnetic exposure. Systolic blood pressure was significantly higher during electromagnetic exposure and heart rate significantly decreased, both during sham and electromagnetic exposure, while the high frequency (150,400 mHz) component of heart rate variability, which is an index of parasympathetic activity, increased as expected during sham exposure but remained unchanged during electromagnetic exposure. Cortisol significantly decreased during sham exposure only. These results show that exposure to an EMF of 37 Hz also alters pain sensitivity in humans and suggest that these effects may be associated with abnormalities in cardiovascular regulation. Bioelectromagnetics 25:167,175, 2004. © 2004 Wiley-Liss, Inc. [source] | |||||||||||||