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Biomedical subjects

Margaret Wilson

Publications and source records attributed to Margaret Wilson.

14 recordsLinked to original sources
PubMed2026

A descriptive analysis of Streptococcus suis-associated disease in Irish pigs from 2010 to 2024: serotypes, pathology, and antimicrobial resistance.

BACKGROUND: Streptococcus suis is a major cause of respiratory and systemic diseases in post-weaned pigs, leading to significant production losses and animal welfare concerns. This study provides the first long-term national level analysis of Streptococcus suis-associated disease (SSAD) in the Republic of Ireland. We examined the pig diagnostic submissions, characterised serotype distribution, antimicrobial susceptibility, and co-infection patterns from 2010 to 2024. RESULTS: The findings confirm that serotypes 9 and 2 or 1/2 were most frequently associated with disease. We observed a significant shift in recent years where serotype 9 has surpassed serotype 2 or 1/2 in number of occurrences. S. suis was frequently co-detected with viral pathogens including porcine reproductive and respiratory syndrome virus (PRRSV), porcine circovirus type 2, and swine influenza virus (SIV), as well as bacterial pathogens such as Actinobacillus pleuropneumonia and Pasteurella multocida, typically from pneumonic lungs. While resistance to tetracycline and erythromycin was high (44.4% to 65.8%), isolates remained susceptible to first-line beta-lactam antibiotics such as penicillin (7.9% resistance), ampicillin (5.5% resistance) and amoxycillin/clavulanate (0% resistance). CONCLUSION: The observed heterogeneity between and within herds challenges successful implementation of vaccination and highlights the need for ongoing disease monitoring. These findings provide the first in-depth assessment of SSAD in Ireland's pig population which will offer valuable insights for future surveillance efforts, including genomic studies and supporting evidence-based strategies and vaccine selection for controlling S. suis in Irish pig sector.

Ireland↗
PubMed2007

Determination of phenolic metabolites of polycyclic aromatic hydrocarbons in human urine as their pentafluorobenzyl ether derivatives using liquid chromatography-tandem mass spectrometry.

Polycyclic aromatic hydrocarbons (PAHs) are ubiquitous environmental contaminants, and a number of them are carcinogenic. One approach for measuring exposure to them is to determine the concentrations of metabolites in urine. The pyrene metabolite 1-hydroxypyrene has been used as a biomarker for exposure in numerous studies. However, determination of exposure to several PAHs may be advantageous, since the relative amounts may vary depending upon the exposure source. We developed a liquid chromatography-tandem mass spectrometry method for the determination of phenolic metabolites of naphthalene, fluorene, phenanthrene, and pyrene in human urine. Following enzymatic cleavage of the glucuronide and sulfate conjugates, the phenolic metabolites are extracted from urine and converted to pentafluorobenzyl ethers. These derivatives greatly enhance the sensitivity of detection by atmospheric pressure chemical ionization in the negative ion mode. Lower limits of quantitation range from 0.01 to 0.5 ng/mL. Stable isotope-labeled internal standards were synthesized or obtained commercially. Data on urinary excretion of several PAH metabolites in urine of smokers and nonsmokers are presented.

Chromatography, Liquid↗
PubMed2005

The case for motor involvement in perceiving conspecifics.

Perceiving other people's behaviors activates imitative motor plans in the perceiver, but there is disagreement as to the function of this activation. In contrast to other recent proposals (e.g., that it subserves overt imitation, identification and understanding of actions, or working memory), here it is argued that imitative motor activation feeds back into the perceptual processing of conspecifics' behaviors, generating top-down expectations and predictions of the unfolding action. Furthermore, this account incorporates recent ideas about emulators in the brain-mental simulations that run in parallel to the external events they simulate-to provide a mechanism by which motoric involvement could contribute to perception. Evidence from a variety of literatures is brought to bear to support this account of perceiving human body movement.

Brain↗
PubMed2005

Carcinogen exposure during short-term switching from regular to "light" cigarettes.

OBJECTIVES: "Light" cigarettes are extremely popular and are perceived by many smokers as less hazardous than higher-yield cigarettes. The objectives of this study were (a) to assess a battery of biomarkers of tobacco smoke exposure that includes tobacco smoke carcinogens, (b) to examine the behavioral nature of compensation, and (c) to examine the consistency of an individual's tobacco smoke exposure when smoking the same cigarette at different times. METHODS: The study was a 3-week crossover study in which smokers smoked their usual cigarettes during weeks 1 and 3, and a light cigarette, with a machine-determined nicotine yield of about 50% of the usual cigarette, during week 2. Blood and urine biomarkers of exposure and subjective questionnaires were collected weekly. RESULTS: Based on cotinine and carboxyhemoglobin levels, compensation averaged 78% and 83%, respectively. Urinary excretion of 4-(methylnitrosamino)-1-(3-pyridyl)-butanol, a metabolite of the tobacco specific carcinogen 4-(methylnitrosamino)-1-(3-pyridyl)-butanone, and a number of polycyclic aromatic hydrocarbon metabolites was similar in all conditions. Compensation was accomplished both by smoking cigarettes more intensively and by smoking more cigarettes per day. Exposures to various tobacco smoke constituents while smoking the usual brand of cigarette in weeks 1 and 3 were highly correlated. CONCLUSION: Our findings support the idea that smokers compensate to a high degree when switched from their usual brand to a light cigarette. Short-term switching resulted in no significant reduction in carcinogen exposure. Our assessment, based on measures of biochemical exposures, supports the idea that switching to light cigarettes is unlikely to reduce the health risks of cigarette smoking.

Adult↗
PubMed2005

An oscillator model of the timing of turn-taking.

When humans talk without conventionalized arrangements, they engage in conversation--that is, a continuous and largely nonsimultaneous exchange in which speakers take turns. Turn-taking is ubiquitous in conversation and is the normal case against which alternatives, such as interruptions, are treated as violations that warrant repair. Furthermore, turn-taking involves highly coordinated timing, including a cyclic rise and fall in the probability of initiating speech during brief silences, and involves the notable rarity, especially in two-party conversations, of two speakers' breaking a silence at once. These phenomena, reported by conversation analysts, have been neglected by cognitive psychologists, and to date there has been no adequate cognitive explanation. Here, we propose that, during conversation, endogenous oscillators in the brains of the speaker and the listeners become mutually entrained, on the basis of the speaker's rate of syllable production. This entrained cyclic pattern governs the potential for initiating speech at any given instant for the speaker and also for the listeners (as potential next speakers). Furthermore, the readiness functions of the listeners are counterphased with that of the speaker, minimizing the likelihood of simultaneous starts by a listener and the previous speaker. This mutual entrainment continues for a brief period when the speech stream ceases, accounting for the cyclic property of silences. This model not only captures the timing phenomena observed inthe literature on conversation analysis, but also converges with findings from the literatures on phoneme timing, syllable organization, and interpersonal coordination.

Communication↗
PubMed2004

The puzzle of working memory for sign language.

Why is immediate-serial-recall (short-term memory) span consistently shorter for sign language than it is for speech? A new study by Boutla et al. shows that neither the length of signs, nor the formational similarity of signed digits, can account for the difference. Their results suggest instead that the answer lies in differences between the auditory and visual systems. At the same time, however, their results show that sign language and spoken language yield equivalent processing spans, suggesting that reliance on immediate-serial-recall measures in clinical and educational testing is misplaced.

Auditory Perception↗
PubMed2003

Imagined movements that leak out.

In a case study that fundamentally alters our understanding of motor imagery, Schwoebel et al. report a patient who unintentionally carries out imagined movements. Furthermore, his 'imagery' movements are more accurate than his intended movements, which suggests that the inhibitory signal that normally prevents us from acting out our motor imagery can be selectively blocked. Removing this inhibition allows us to observe motor imagery 'in action', and reveals that motor imagery and motor planning for execution are not identical.

Journal Article↗
PubMed2003

The effect of irrelevant visual input on working memory for sign language.

We report results showing that working memory for American Sign Language (ASL) is sensitive to irrelevant signed input (and other structured visual input) in a manner similar to the effects of irrelevant auditory input on working memory for speech. Deaf signers were disrupted on serial recall of lists of ASL signs when either pseudosigns or moving shapes were presented during a retention interval. Hearing subjects asked to recall lists of printed English words did not show disruption under the same interference conditions. The results favor models that hypothesize modality-specific representations of language within working memory, as opposed to amodal representations. The results further indicate that working memory for sign language involves visual or quasi-visual representations, suggesting parallels to visuospatial working memory.

Journal Article↗
PubMed2002

Determination of 4-hydroxy-3-methoxyphenylethylene glycol 4-sulfate in human urine using liquid chromatography-tandem mass spectrometry.

A major metabolite of norepinephrine (NE) in brain is 4-hydroxy-3-methoxyphenylethylene glycol (MHPG). In many species, a large fraction of MHPG formed in brain is converted to the sulfate conjugate. Consequently, MHPG sulfate has been proposed as a biomarker for NE metabolism in the central nervous system. As part of the clinical trials of the monoamine oxidase inhibitor selegiline for treating cocaine addiction, we required a method for measuring urine concentrations of MHPG sulfate. Using a deuterium-labeled analogue as an internal standard, we developed a liquid chromatography-electrospray ionization tandem mass spectrometry (LC-MS/ MS) method for determination of MHPG sulfate in human urine. Sample preparation involves simply diluting 50 microL of urine with 1 mL of ammonium formate buffer and adding the internal standard. The sample is centrifuged, the supernate is transferred to an autosampler vial, and 10 microL is injected into the LC-MS/MS system. Standard curves from 50 to 10,000 ng/mL are generated. Only one sample of 277 clinical samples analyzed had a concentration outside of this range. Precision (coefficient of variation) ranged from 1.9 to 9.7%, and accuracy ranged from 97 to 103% of expected values for controls prepared by spiking sulfatase-treated urine with MHPG sulfate.

Arylsulfatases↗
PubMed2002

Six views of embodied cognition.

The emerging viewpoint of embodied cognition holds that cognitive processes are deeply rooted in the body's interactions with the world. This position actually houses a number of distinct claims, some of which are more controversial than others. This paper distinguishes and evaluates the following six claims: (1) cognition is situated; (2) cognition is time-pressured; (3) we off-load cognitive work onto the environment; (4) the environment is part of the cognitive system; (5) cognition is for action; (6) off-line cognition is body based. Of these, the first three and the fifth appear to be at least partially true, and their usefulness is best evaluated in terms of the range of their applicability. The fourth claim, I argue, is deeply problematic. The sixth claim has received the least attention in the literature on embodied cognition, but it may in fact be the best documented and most powerful of the six claims.

Animals↗
PubMed2002

A comparison of once-daily tramadol with normal release tramadol in the treatment of pain in osteoarthritis.

OBJECTIVE: To compare the efficacy and tolerability of once daily (OD) tramadol tablets with normal release tramadol capsules (50 mg) taken 3 or 4 times daily in a multicenter, double blind, double dummy parallel study. METHODS: Patients with moderate to severe pain due to osteoarthritis (OA) were recruited from general practice. Following a titration period of a week, patients were assessed over one month for the analgesic efficacy and tolerability of the test medications. RESULTS: Both treatments were shown to be effective. There was no difference between treatments and both produced good pain control as shown by clinically relevant decreases from baseline pain scores, low escape medication use, and sleep disturbance. The efficacy of the OD tramadol over the 24 h dosing interval was confirmed by the low sleep disturbance, absence of "end of dose" effects in morning pain scores, and low escape medication use. Of the 279 patients recruited, 140 withdrew, mostly because of adverse events. The adverse event profiles were typical of opioids and were similar for both treatments. CONCLUSION: Tramadol OD was at least as effective and well tolerated as normal release tramadol in the management of OA pain. However, OD tramadol offers the advantage of a reduced dosing regimen, which is especially valuable in the elderly population.

Analgesics, Opioid↗