Biomedical subjects

M Good

Publications and source records attributed to M Good.

At least 19 recordsLinked to original sources

PubMed2004

The effect of the tuberculin test and the consequences of a delay in blood culture on the sensitivity of a gamma-interferon assay for the detection of Mycobacterium bovis infection in cattle.

The strategic use of the gamma-interferon (IFN-gamma) assay (Bovigam) can provide a means for the early identification of Mycobacterium bovis infected cattle, thus ensuring their removal from an infected herd. It has been reported that performance of the test can be influenced by various factors including a recent tuberculin skin test and the length of delay between collection and processing of blood samples. In this study, single intradermal comparative tuberculin test (SICTT) reactor and non-reactor cattle were recruited from herds infected with M. bovis and grouped according to their SICTT responses. Group 1 comprised reactor cattle selected on the basis of their SICTT response to PPD-bovine (purified protein derivative of tuberculin) exceeding that of PPD-avian by at least 12mm. Group 2 animals were selected from herds undergoing routine surveillance for bovine tuberculosis and contained standard SICTT reactor cattle (PPD-bovine exceeding that of PPD-avian by at least 4mm) and non-reactors. We investigated the effects of the SICTT on the assay results by measuring the in vitro IFN-gamma responses of Group 1 reactor cattle at time intervals pre- and post-skin test. No significant differences were measured in the IFN-gamma responses of the reactor animals to PPD-bovine and PPD-avian for up to 65 days. To investigate if a delay in processing of blood affected the performance of the assay, we compared results using duplicate blood samples from Group 1 and Group 2 cattle stimulated with PPD antigen at 8h and at 24h after collection. In both groups of animals the mean optical density (OD) values of the assay at 24h post-collection were significantly lower than those at 8h. Our results demonstrated that a delay in processing of the blood samples from cattle subjected to routine surveillance could significantly impact on the outcome of the IFN-gamma assay resulting in a change of the IFN-gamma status of the animals.

Animals↗

PubMed2004

Responsiveness of the electronic touch screen WOMAC 3.1 OA Index in a short term clinical trial with rofecoxib.

BACKGROUND: The Western Ontario and McMaster Universities (WOMAC) Osteoarthritis Index is a self-administered validated questionnaire for patients with osteoarthritis (OA) of the hip or knee. The electronic touch screen version of the WOMAC (e-WOMAC) has been previously shown to be highly correlated with the original paper format. However, whether the e-WOMAC would be suitable for monitoring the effects of drug treatment is unknown. AIM: To validate the longitudinal use of the e-WOMAC questionnaire and its ability to detect changes in WOMAC-scores induced by drug treatment in outpatient care. METHODS: Fifty-three outpatients, men and women (mean age: 64 years; SD+/-9.5), with symptomatic osteoarthritis of hip or knee were included in an open label study with rofecoxib. At three visits over 3 weeks, responsiveness of the WOMAC 3.1 regarding the three subscales, pain, stiffness and function, were compared for the original paper format and the computer touch screen format (QUALITOUCH) using a Likert scale. WOMAC scores were transformed to the 0-100 scale. ANOVA for repeated measures was used for analysis and effect sizes by subscale were compared for both formats. RESULTS: Responsiveness for all three subscales was similar between formats. In both formats, pain and stiffness were significantly reduced with rofecoxib as early as 7 days, while functional ability was significantly increased (P<0.01 for all aggregate subscale scores) with continuing improvement until the end of study. The effect sizes by subscale between Day 1 and 21 were not statistically different between the paper and the electronic version of the questionnaire and showed similar clinically meaningful improvements in WOMAC scores over 3 weeks. CONCLUSION: In this longitudinal intervention study, the e-WOMAC OA Index 3.1 showed similar responsiveness in detecting clinically meaningful changes than the original paper format.

Aged↗

PubMed2004

Hippocampal lesions modulate both associative and nonassociative priming.

In associative priming, rats are more likely to orient to a visual stimulus whose memory has not been recently activated (V1) than to one whose memory has been recently activated (V2). However, rats with excitotoxic hippocampal lesions are more likely to orient to the primed V2 than to the unprimed V1. This study investigated the influence of hippocampal lesions on nonassociative priming. Rats received presentations of 2 visual stimuli, V1 and V2, that had been presented more (V2, primed) or less (V1, unprimed) recently. Control rats oriented to V1 rather than to V2, whereas hippocampal rats oriented to V2 rather than to V1. These results parallel those observed in an associative priming procedure and thereby suggest that the role of the hippocampus in priming is general.

Animals↗

PubMed2003

Entorhinal cortex lesions disrupt the transition between the use of intra- and extramaze cues for navigation in the water maze.

This study with rats examined the effects of excitotoxic lesions to the entorhinal cortex (EC) and hippocampus (HPC) on using extramaze and intramaze cues to navigate to a hidden platform in a water maze. HPC lesions resulted in a disruption to the use of extramaze cues, but not intramaze cues, whereas EC lesions had no effect on the use of these cues when they were encountered for the first time. However, prior navigation training in which 1 type of cue was relevant disrupted navigation with the other type in rats with EC lesions. Results show that the EC contributes to the processing of spatial information, but that this contribution is most apparent when there is a conflict between 2 sources of navigational cues in the water maze.

Animals↗

PubMed2003

Using idiothetic cues to swim a path with a fixed trajectory and distance: necessary involvement of the hippocampus, but not the retrosplenial cortex.

Rats rapidly learned to find a submerged platform in a water maze at a constant distance and angle from the start point, which changed on every trial. The rats performed accurately in the light and dark, but prior rotation disrupted the latter condition. The rats were then retested after receiving cytotoxic hippocampal or retrosplenial cortex lesions. Retrosplenial lesions had no apparent effect in either the light or dark. Hippocampal lesions impaired performance in both conditions but spared the ability to locate a platform placed in the center of the pool. A hippocampal deficit emerged when this pool-center task was run in the dark. The spatial effects of hippocampal damage extend beyond allocentric tasks to include aspects of idiothetic guidance.

Animals↗

PubMed2003

Environmental flow requirements in arid zone rivers--a case study from the Lake Eyre Basin, central Australia.

The ARIDFLO project takes a multi-disciplinary approach to the collection and analysis of data required to formulate appropriate environmental flow requirements for rivers in the Lake Eyre Basin. The key drivers of the ecological processes underpinning the health of these rivers are identified by modelling whole-of-ecosystem biological responses to hydrological events over a range of spatial and temporal scales. First, the hydrology of these poorly gauged (often ungauged) rivers needs to be modelled and validated to mimic real flow and inundation patterns at the catchment, reach and waterbody scale. Modelled and actual discharge data are then used to provide a suite of hydrological predictor variables which, in conjunction with other environmental variables, are used to model observed biotic responses. The key hydrologic and environmental drivers identified by the statistical models need to be taken into account when determining environmental flow requirements for these river systems. Further work is required to assess the predictive power of the models in the highly variable, complex systems of the Lake Eyre Basin rivers.

Australia↗

PubMed2002

The influence of selective lesions to components of the hippocampal system on the orienting [correction of orientating] response, habituation and latent inhibition.

The contribution that components of the hippocampal system in the rat make to the modulation of attention or stimulus processing was assessed using several simple behavioural assays: the orienting response (OR) to a novel stimulus, the subsequent habituation and dishabituation of this OR, and the latent inhibition effect that typically results from repeated exposure to a stimulus. Excitotoxic lesions of components of the hippocampal system produce dissociable effects on the OR, habituation and latent inhibition: lesions of the entorhinal cortex have no effect on the OR or changes in the OR during exposure to a stimulus, but disrupt latent inhibition; lesions of the subiculum disrupt the OR but not latent inhibition; and lesions of the hippocampus disrupt the OR and latent inhibition. These effects have important implications for our understanding of habituation and latent inhibition, and the neural mechanisms involved in attentional modulation.

Animals↗

PubMed2002

Acquired equivalence and distinctiveness of cues: II. Neural manipulations and their implications.

Neural manipulations were used to examine the mechanisms that underlie the acquired equivalence and distinctiveness of cues in rats. Control rats and those with excitotoxic lesions of either the hippocampus (HPC) or entorhinal cortex (EC) acquired the following conditional discrimination: In Contexts A and B, Stimulus X-->food and Stimulus Y-->no food, and in Contexts C and D, Y-->food and X-->no food. Rats then received many food pellets in A but not in C. After this treatment, control rats showed more magazine activity in B than in D--an acquired equivalence-distinctiveness effect. This effect was also evident in HPC rats but not in EC rats. These results indicate that changes in stimulus distinctiveness are dissociable from the process of conditional learning.

Analysis of Variance↗

PubMed2001

Influence of a beacon on spatial learning based on the shape of the test environment.

In 5 experiments rats were required to escape from a triangular shaped pool by swimming to a submerged platform. The principal group of interest in each experiment received training with a beacon attached to the platform. The purpose of the experiments was to assess if the beacon overshadowed (Experiments 1-4) or blocked (Experiment 5) learning about the position of the platform with reference to the shape of the pool. The platform was located in the center of the pool for the first 2 experiments and in a corner for the remaining experiments. Although there was an overshadowing effect in Experiment 1, the remaining experiments failed to reveal any disruptive influence of the beacon on learning based on the shape of the pool. Moreover, in Experiments 3-5 there was an indication that the beacon facilitated such learning. The results suggest that spatial learning based on the shape of a test environment may not take place in the same way as that based on more discrete landmarks.

Animals↗

PubMed2001

Involvement of the entorhinal cortex in a process of attentional modulation: evidence from a novel variant of an IDS/EDS procedure.

Novel behavioral assays were used to assess the role of the entorhinal cortex in modulating attention to components of stimulus compounds. In Stage 1, rats received discrimination training with compounds constructed from 3 dimensions (auditory, visual, and tactile); in each compound the combination of components from 2 dimensions (e.g., auditory and visual) were relevant to the solution of the discrimination, and the remaining dimension (e.g., tactile) was irrelevant. In Stage 2, rats received a different discrimination in which the relevant dimensions were either congruent (auditory and visual) or incongruent (auditory and tactile) with those that were relevant in Stage 1. Sham-operated rats acquired the congruent discrimination more rapidly than the incongruent discrimination--a finding indicative of a process of attentional modulation--whereas rats with excitotoxic lesions of the entorhinal cortex acquired both discriminations equally readily.

Animals↗

PubMed2001

Excitotoxic lesions of the hippocampus leave sensory preconditioning intact: implications for models of hippocampal function.

Learning about contextual cues is markedly disrupted in rats with hippocampal lesions. One analysis of this disruption is that it reflects a general failure to form associations between the elements of complex events. A straightforward prediction of this analysis is that sensory preconditioning will be disrupted by hippocampal lesions. This prediction was assessed by presenting rats with flavored solutions composed of 2 elements (A and X) before X was paired with an injection of the emetic, lithium chloride. A subsequent test revealed that rats were less willing to consume Solution A than they were to consume a control solution, B. This was true of rats with sham lesions and those with excitotoxic lesions of hippocampus. These findings fail to support the proposition that the hippocampus-dependent deficit in contextual conditioning is due to a general disruption to the process of associating the elements of complex events.

Animals↗

PubMed2001

Relaxation and music to reduce postsurgical pain.

AIMS: We investigated the effects of relaxation, music, and the combination of relaxation and music on postoperative pain, across and between two days and two activities (ambulation and rest) and across ambulation each day. This secondary analysis of a randomized controlled trial was conducted from 1995 to 1997. BACKGROUND: After surgery, patients do not always receive sufficient relief from opioids and may have undesired side-effects. More complete relief (10-30%) was found recently with adjuvant interventions of relaxation, music, and their combination. Comparison of effects between days and treatments have not been examined longitudinally. METHODS: With a repeated measures design, abdominal surgery patients (n = 468) in five US hospitals were assigned randomly to one of four groups; relaxation, music, their combination, and control. With institutional approval and written informed consent, subjects were interviewed and taught interventions preoperatively. Postoperative testing was at ambulation and rest on days 1 and 2 using visual analogue (VAS) sensation and distress of pain scales. RESULTS: Multivariate analysis indicated that although pain decreased by day 2, interventions were not different between days and activities. They were effective for pain across ambulation on each day, across ambulation and across rest over both days (all P < 0.001), and had similar effects by day and by activity. CONCLUSION: Nurses can safely recommend any of these interventions for pain on both postoperative days and at both ambulation and rest.

Combined Modality Therapy↗

PubMed2001

Sensation and Distress of Pain Scales: reliability, validity, and sensitivity.

Psychometric properties of the Sensation and Distress of Pain Visual Analogue Scales (VAS) are compared to dual numerical rating scales (NRS) with data from a randomized controlled trial of postoperative patients. On postoperative days 1 and 2, 15-minute test-retest reliability was .73 to .82 for the VAS and slightly lower for the NRS, r = .72 to .78, while convergent validity of the scales ranged from r = .90 to .92; construct validity of sensation and distress ranged from r = .72 to .85; and discriminant validity was lower, r = .65 to .78. Both instruments were significantly associated with pain reduction following treatment, p < .05 to .01. The VAS scores were significantly lower, p < .01 to .001, and more evenly distributed than NRS scores. It is recommended that the VAS be used in research to produce continuous scores that are more suited to parametric analysis.

Humans↗

PubMed2000

Identifying cortical inputs to the rat hippocampus that subserve allocentric spatial processes: a simple problem with a complex answer.

A consideration of the cortical projections to the hippocampus provides a number of candidate regions that might provide distal sensory information needed for allocentric processing. Prominent among the input regions are the entorhinal cortex, the perirhinal cortex, the postrhinal cortex, and the retrosplenial cortex. A review of these sites reveals the surprising fact that in spite of their anatomical connections, removal of the perirhinal and postrhinal cortices has little or no effect on spatial tasks and hence does not functionally disconnect the hippocampus. Extensive retrosplenial lesions have only mild effects, and even lesions of the entorhinal cortex only partially mimic the effects of hippocampal lesions upon tests of spatial memory. In contrast, studies using c-fos imaging support the involvement of the entorhinal, postrhinal, and retrosplenial cortices, but not the perirhinal cortex. It is argued that there exist multiple aspects of spatial memory, and this is reflected in the multiple routes by which cortical information can reach the hippocampus. One consequence is that lesions in a single site often have surprisingly mild effects on standard spatial tests.

Afferent Pathways↗

PubMed2000

Associative components of recognition memory.

Recent results indicate that visual recognition memory (as assessed by habituation and dishabituation of the orienting response) is influenced by associative knowledge, and that this influence is mediated by the hippocampus. A standard, associative model of learning has been recently reported to provide a parsimonious explanation for these results.

Animals↗

PubMed2000

Associative modulation of the orienting response: distinct effects revealed by hippocampal lesions.

The ability of auditory stimuli to modulate rats' tendency to orient to visual targets was assessed. In Experiment 1, trials where an auditory stimulus (A) signaled one visual array (X) were intermixed with unsignaled presentations of a second array (Y). Comparison of the orienting responses (ORs) to X and Y revealed that A produced a transient (unconditioned) and an emerging (conditioned) disruptive influence on the OR to X. In Experiments 2 and 3, trials where A signaled X were intermixed with others where another auditory stimulus (B) signaled Y. Stimulus A's ability to modulate the OR to X was then assessed by presenting A prior to test arrays containing both X and Y. Control rats were more likely to orient to Y than X (Experiments 2 and 3) and rats with excitotoxic lesions of the hippocampus were more likely to orient to X than Y (Experiment 3). These results show that auditory stimuli exert distinct modulatory influences on the OR to visual stimuli with which they are associated.

Animals↗

PubMed2000

The effects of combined lesions of the subicular complex and the entorhinal cortex on two forms of spatial navigation in the water maze.

The role of the subicular complex and entorhinal cortex (SUB-EC) in spatial learning was examined in 2 water maze experiments. In Experiment 1, rats had to locate a hidden platform that was always a fixed distance and direction from an intramaze landmark. Each day, the landmark and platform were moved to a new location. Both control and SUB-EC-lesioned rats learned to locate the platform equally readily during training. However, the control group was impaired in locating the platform when the visual extramaze cues were concealed, whereas the lesioned group was unaffected by this manipulation. In Experiment 2, the lesioned rats were impaired in finding a hidden platform that was in a fixed place in the water maze and showed no evidence of having learned its location in a probe test. These results suggest that damage to the SUB-EC impairs the integration of geometric information but spares a more general navigational-directional strategy.

Animals↗

PubMed2000

Pain after gynecologic surgery.

This article provides a descriptive profile of pain in 80 women during the first 2 days after gynecologic surgery in 4 hospitals. Surgical procedures included abdominal hysterectomy, oophorectomy, and laparotomy. Average pain was moderate on both days, but paired t tests indicated that pain increased significantly during ambulation on day 1 (P = .009, sensation; P < .001, distress) and on day 2 (P = .007, sensation; P = .030, distress). They both (P = .001) decreased significantly during rest on day 1, but not on day 2. Analysis of quartiles indicated that one fourth of the sample suffered severe sensation pain at all points on day 1 (60 to 74 mm on a 100-mm visual analogue scale), and moderate to severe sensation on day 2 (40 to 60 mm). The lowest quartile had mild pain on both days (11 to 28 mm on day 1, and 7 to 14 mm on day 2). Some patients (30%) reported that pain interrupted their sleep on the first 2 nights, and difficulty sleeping on the first postoperative night for any reason (65%) was related to greater pain during the next 2 days (r = .25 to .43). Although 41% of the women had previously used relaxation techniques for stress or pain, only 9% used it for pain after surgery. Results suggest that postoperative patients have moderate to severe pain that is incompletely relieved with patient-controlled analgesia. Nurses should encourage patients to press the patient-controlled analgesia button more often, report unrelieved pain, and use nonpharmacologic interventions.

Adult↗