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Price MJ, Smith PM, Bottoms LM, Hill MW. The effect of age and sex on peak oxygen uptake during upper and lower body exercise: A systematic review. Exp Gerontol 2024; 190:112427. [PMID: 38604251 DOI: 10.1016/j.exger.2024.112427] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2023] [Revised: 04/04/2024] [Accepted: 04/08/2024] [Indexed: 04/13/2024]
Abstract
BACKGROUND Large scale population norms for peak oxygen uptake (VO2peak) during cycle ergometry (CE) have been published for men and women across a wide range of ages. Although upper body functional capacity has an important role in activities of daily living far less is known regarding the effect of age and sex on upper body functional capacity (i.e. arm crank ergometry; ACE). The aim of this review was to determine the effect of age and sex on VO2peak obtained during ACE and CE in the same participants. METHOD The review was pre-registered with PROSEPERO (Ref: CRD42022349566). A database search using Academic Search Complete including CINAHL complete, CINHAL Ultimate, Medline, PubMed, SPORTDiscus was undertaken. RESULTS The initial search yielded 460 articles which was reduced to 243 articles following removal of duplicates. Twenty-five articles were subsequently excluded based on title resulting in 218 articles considered for retrieval. Following review of the abstracts, 78 further articles were excluded leaving 140 to be assessed for eligibility. Eighty-five articles were subsequently excluded, resulting in 55 articles being included. The decrease in VO2peak with age during CE was consistent with previous studies. Decreases in VO2peak during ACE with age, although paralleling those of CE, appeared to be of greater functional importance. When changes in VO2peak were considered below the age of 50 years little change was observed for absolute VO2peak during ACE and CE. In contrast, relative VO2peak demonstrated decreases in VO2peak for both ACE and CE likely reflecting increases in body mass and body fat percentage with age. After 50 years of age absolute and relative VO2peak demonstrated more similar and subtle responses. Heterogeneity across studies for both absolute and relative VO2peak between ACE and CE was large. Although strict inclusion criteria were applied, the inter-individual variation in sample populations was likely the main source of heterogeneity. There was a considerable lack data sets available for ages above 40 years of age. CONCLUSIONS These responses suggest that upper body VO2peak decreases in line with that of the lower body but, due to the lower peak values achieved during ACE, decreases in VO2peak may have more profound functional impact compared to that for the lower body. Using absolute and relative measures of VO2peak results in different age-related profiles when considered below 50 years of age. To further our understanding of whole body ageing more data is required for participants in mid and later life. The association between VO2peak and underlying physiological factors with age needs to be studied further, particularly in conjunction with activities of daily living and independent living.
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Affiliation(s)
- M J Price
- Physical Activity, Sport and Exercise Sciences Research Centre, Coventry University, Coventry CV1 5FB, UK.
| | - P M Smith
- Cardiff Metropolitan University, Cyncoed Campus, Cyncoed Road, Cardiff CF23 6XD, UK
| | - L M Bottoms
- Department of Psychology, Sport and Geography, University of Hertfordshire, Hatfield AL10 9AB, UK
| | - M W Hill
- Physical Activity, Sport and Exercise Sciences Research Centre, Coventry University, Coventry CV1 5FB, UK
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Mirza MB, Smith PM, Wang Y, Naveed A, Washington MK, Xu Y, Idrees K. Intra-Patient Heterogeneity in Micro-satellite-stable Colorectal Metastases: Does Immunotherapy Have a Role in Colorectal Peritoneal Metastases? Ann Surg Oncol 2024; 31:1440-1443. [PMID: 38110752 DOI: 10.1245/s10434-023-14694-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2023] [Accepted: 11/16/2023] [Indexed: 12/20/2023]
Affiliation(s)
- M B Mirza
- Division of Surgical Oncology and Endocrine Surgery, Department of Surgical Sciences, Vanderbilt University Medical Center, Nashville, TN, USA
| | - P Marincola Smith
- Division of Surgical Oncology and Endocrine Surgery, Department of Surgical Sciences, Vanderbilt University Medical Center, Nashville, TN, USA
| | - Y Wang
- Department of Biostatistics, Vanderbilt University Medical Center, Nashville, TN, USA
| | - A Naveed
- Division of Otolaryngology, Head and Neck Surgery, Department of Surgical Sciences, Vanderbilt University Medical Center, Nashville, TN, USA
| | - M K Washington
- Department of Pathology, Microbiology, and Immunology, Vanderbilt University Medical Center, Nashville, TN, USA
| | - Y Xu
- Department of Biostatistics, Vanderbilt University Medical Center, Nashville, TN, USA
| | - K Idrees
- Division of Surgical Oncology and Endocrine Surgery, Department of Surgical Sciences, Vanderbilt University Medical Center, Nashville, TN, USA.
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Soden D, Meyer JE, Briskin SM, Dundr JM, Brennan B, Smith PM, Bailey CM. A-43 Effects of Subthreshold Exercise on Post-concussive Symptom Endorsement and Cognition: A Pilot Randomized Clinical Trial. Arch Clin Neuropsychol 2022. [DOI: 10.1093/arclin/acac32.43] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Abstract
Purpose: The current study examined the effects of subthreshold exercise on symptom endorsement and neurocognitive functioning in adolescents with persisting concussion symptoms (>1 month). Methods: Sixteen participants (age M = 16.2, SD = 1.4) with persisting concussion symptoms were randomly assigned to control or subthreshold exercise intervention groups (Leddy et al., 2019). Participants engaged in concussion education before assignment to 6 weeks (3x weekly) of intervention: control (stretching) or subthreshold exercise. Both groups completed evaluations at baseline, midpoint, and follow-up, including a hybrid battery of assessments (yielding composites of processing speed and memory), a concussion symptom scale (PCS-R), and psychological inventories. Results: Both the intervention group and control group reported significant reduction in concussive symptom severity during the study period (PCS-R Change M = -21.29, SD = 13.54). Baseline endorsement of anxiety significantly differed across groups (p < 0.05); when controlling for anxiety, the intervention group demonstrated greater reduction in symptom endorsement compared to controls (F(1,13) = 7.30, p < 0.05, partial eta2 = 0.40). In contrast, after controlling for performance validity and the baseline anxiety difference, there was no significant difference (p > 0.05) in processing speed performance (partial eta2 = 0.14) or memory performance (partial eta2 = 0.11) by intervention group. Both groups remained generally intact normatively from the baseline to the follow-up evaluation across measures. Conclusions: Current results support the use of subthreshold exercise to reduce persisting symptoms of concussion post-acutely; additionally, results suggest that anxiety significantly impacted response to intervention. Lastly, there was no effect on cognitive indices by the intervention, suggesting that subthreshold exercise may have less impact on cognition than symptom endorsement in the post-acute phase of recovery.
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Baechle JJ, Smith PM, Ortega CA, Wang TS, Solórzano CC, Kiernan CM. Clinical Predictors of Pseudohypoxia-Type Pheochromocytomas. Ann Surg Oncol 2022; 29:3536-3546. [PMID: 35233740 DOI: 10.1245/s10434-022-11419-1] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2021] [Accepted: 01/16/2022] [Indexed: 12/29/2022]
Abstract
INTRODUCTION Pheochromocytomas (PCCs) are rare tumors of neural crest origin with divergent transcriptional and metabolic profiles associated with mutational cluster types. Pseudohypoxia-type (PHT) PCCs have a poor prognosis; however diagnostic genetic testing is not always available. We aimed to investigate clinical parameters predictive of PHT PCCs. METHODS Patients who underwent resection and genetic testing for PCC at two academic centers from 2006-2020 were retrospectively studied. Patients with PHT mutations (SDH-AF2/B/C/D, VHL) were compared to non-pseudohypoxia-type (nonPHT) PCCs to identify widely available clinical parameters predictive of PHT PCCs. Demographic, clinical, and pathologic characteristics were compared using student's T and ANOVA tests. Operative hemodynamic instability was defined as systolic blood pressure (SBP) > 200 mmHg, SBP increase of > 30% relative to baseline, and/or heart rate (HR) > 110 bpm. Mann-Whitney U test was used to assess area under the curve (AUC), sensitivity, and specificity. Recursive partitioning was used to model predictive thresholds for PHT PCC and develop a predictive score. RESULTS Of the 79 patients included in the cohort, 17 (22%) had PHT and 62 (78%) had nonPHT PCCs. PCC patients with > 2 of the examined predictive clinical parameters (preoperative weight loss [> 10% body weight], elevated preoperative hematocrit [> 50%], normal baseline heart rate [< 100 bpm], and normal plasma metanephrines [< 0.60 nmol/L]) were more likely to have PHT PCCs (AUC = 0.831, sensitivity = 0.882, specificity = 0.694, all p < 0.001). CONCLUSIONS Widely available preoperative clinical parameters including indicators of erythropoiesis (hemoglobin, hematocrit, and red blood cell count), baseline heart rate, plasma metanephrines, and weight loss may be useful predictors of PHT PCCs and may help guide management of PCCs when genetic testing is unavailable/delayed.
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Affiliation(s)
- J J Baechle
- School of Medicine, Meharry Medical College, Nashville, TN, USA
| | - P Marincola Smith
- Division of Surgical Oncology and Endocrine Surgery, Vanderbilt University Medical Center, Nashville, TN, USA
| | - C A Ortega
- School of Medicine, Vanderbilt University, Nashville, TN, USA
| | - T S Wang
- Department of Surgery, Medical College of Wisconsin, Milwaukee, WI, USA
| | - C C Solórzano
- Division of Surgical Oncology and Endocrine Surgery, Vanderbilt University Medical Center, Nashville, TN, USA
| | - C M Kiernan
- Division of Surgical Oncology and Endocrine Surgery, Vanderbilt University Medical Center, Nashville, TN, USA.
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Velie BD, Smith PM, Fjordbakk CT, Solé M, Jäderkvist Fegraeus K, Rosengren MK, Røed KH, Ihler CF, Lindgren G, Strand E. Exploring the genetics underpinning dynamic laryngeal collapse associated with poll flexion in Norwegian-Swedish Coldblooded Trotter racehorses. Equine Vet J 2019; 52:174-180. [PMID: 31461557 DOI: 10.1111/evj.13171] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2019] [Accepted: 08/15/2019] [Indexed: 12/19/2022]
Abstract
BACKGROUND Dynamic laryngeal collapse (DLC) associated with poll flexion is the most common disorder of the upper respiratory tract (URT) in the Norwegian-Swedish Coldblooded Trotter (NSCT). The disorder, which has also been diagnosed in other breeds of trotters and gaited horses, appears to be related to anatomic phenotypes and only occurs during poll flexion when the horse is exercised 'on the bit'. OBJECTIVES Identify genomic regions associated with DLC in the NSCT by combining a rigorous phenotyping protocol with genomic data from a high-density equine genotyping array. STUDY DESIGN Prospective case/control study. METHODS High-speed treadmill endoscopy was used to phenotype horses (n = 61) for DLC, distinguishing between cases and controls. Genome-wide association (GWA) analysis of DLC status was then performed using a principal component approach (PCA) with haplotype analyses subsequently performed for regions containing single-nucleotide polymorphisms (SNPs) above the suggestive genome-wide significance (GWS) threshold (P<1.0 × 10-5 ). RESULTS One region containing 10 SNPs (Equus caballus chromosome [ECA] 7: 89,601,935-94,647,192) was above the suggestive GWS threshold. Two inferred haplotypes in this region demonstrated significant differences (P<0.001) between cases and controls, with the most frequent haplotype resulting in a significantly increased risk of DLC. MAIN LIMITATIONS Small sample size as a result of stringent phenotyping protocols. CONCLUSIONS The current study highlights a candidate genomic region on ECA7 as potentially important with regard to the manifestation of DLC. Further exploration of this region and the genes included within it will bring veterinarians and researchers closer to fully understanding the biological mechanisms underlying DLC in horses.
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Affiliation(s)
- B D Velie
- Faculty of Science, School of Life and Environmental Sciences, University of Sydney, Sydney, Australia.,Department of Animal Breeding and Genetics, Swedish University of Agricultural Sciences, Uppsala, Sweden
| | - P M Smith
- Department of Companion Animal Clinical Sciences, Norwegian University of Life Sciences, Oslo, Norway
| | - C T Fjordbakk
- Department of Companion Animal Clinical Sciences, Norwegian University of Life Sciences, Oslo, Norway
| | - M Solé
- Department of Animal Breeding and Genetics, Swedish University of Agricultural Sciences, Uppsala, Sweden
| | - K Jäderkvist Fegraeus
- Department of Animal Breeding and Genetics, Swedish University of Agricultural Sciences, Uppsala, Sweden
| | - M K Rosengren
- Department of Animal Breeding and Genetics, Swedish University of Agricultural Sciences, Uppsala, Sweden
| | - K H Røed
- Department of Basic Sciences and Aquatic Medicine, Norwegian University of Life Sciences, Oslo, Norway
| | - C F Ihler
- Department of Companion Animal Clinical Sciences, Norwegian University of Life Sciences, Oslo, Norway
| | - G Lindgren
- Department of Animal Breeding and Genetics, Swedish University of Agricultural Sciences, Uppsala, Sweden.,Livestock Genetics, Department of Biosystems, KU Leuven, Leuven, Belgium
| | - E Strand
- Department of Companion Animal Clinical Sciences, Norwegian University of Life Sciences, Oslo, Norway
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Smith PM, Tawadros C, Fletcher N, Betts CD. A method for securing the temporary lead(s) in sacral nerve stimulation. Ann R Coll Surg Engl 2018; 100:247-248. [DOI: 10.1308/rcsann.2017.0134] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Affiliation(s)
- PM Smith
- Department of Urology, Salford Royal Foundation Trust, Salford, UK
| | - C Tawadros
- Clinique de Genolier, Genolier, Switzerland
| | - N Fletcher
- Department of Urology, Salford Royal Foundation Trust, Salford, UK
| | - CD Betts
- Department of Urology, Salford Royal Foundation Trust, Salford, UK
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Abstract
Using the Nottingham introducer and diazepam sedation, 93 of 100 patients with oesophagogastric malignancy have been successfully intubated, 67 with Celestin tubes and 26 with Atkinson tubes. Their mean age was 72 years (range 36–91). Six of the failures were in patients with fundal adenocarcinoma. Sixty-nine patients were discharged from hospital after initial intubation (74%). Nine patients developed a perforation, 6 died and there were 5 deaths from aspiration. Nine patients are alive up to 11 months later. The mean survival after discharge was four months with a maximum of 18 months. Later 11 tubes obstructed and 12 Celestin tubes displaced upward. Endoscopic insertion of oesophageal prosthetic tubes provides satisfactory palliation for inoperable oesophagogastric malignancy. The development of the Atkinson tube with a distal flange has eliminated tube displacement upwards.
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Abstract
BACKGROUND One explanation for why older age is associated with greater duration of wage replacement following a work-related injury may be that older workers sustain more severe injuries and different types of injury compared with their younger counterparts. AIMS To examine the role of injury-related characteristics in explaining the impact of age on wage replacement duration, and whether the relationship between age and wage replacement duration is consistent across injury types and levels of severity. METHODS A secondary analysis of workers' compensation claims in the Australian state of Victoria. In Victoria, only injuries which have accumulated >10 days of wage replacement, or have health care expenditures above a financial threshold, are eligible for compensation. Nested regression models were used to examine the relative contribution of injury-related characteristics to age differences in wage replacement duration. RESULTS Older age was associated with greater days of wage replacement among men and women, even after adjusting for injury characteristics. Adjustment for differences in injury types and compensation reporting practices resulted in moderate attenuation of the age-duration relationship among men and small attenuation among women. The age-duration relationship was consistent across injury types/severity. CONCLUSIONS The relationship between older age and greater duration of wage replacement is ubiquitous across injuries of different types and severity. Future research is required to understand better why older age is consistently associated with worse compensation outcomes following work-related injury.
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Affiliation(s)
- J K Fan
- Institute for Work & Health, Toronto, Ontario M5G 2E9, Canada, .,Dalla Lana School of Public Health, University of Toronto, Toronto, Ontario M5T 3M7, Canada
| | - O Black
- School of Public Health and Preventive Medicine, Monash University, Alfred Hospital, Melbourne, Victoria 3004, Australia
| | - P M Smith
- Institute for Work & Health, Toronto, Ontario M5G 2E9, Canada.,Dalla Lana School of Public Health, University of Toronto, Toronto, Ontario M5T 3M7, Canada.,School of Public Health and Preventive Medicine, Monash University, Alfred Hospital, Melbourne, Victoria 3004, Australia
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Affiliation(s)
- K J W Taylor
- Department of Diagnostic Radiology, Yale University School of Medicine, New Haven, Connecticut, USA
| | - J J Barrett
- Department of Nuclear Medicine, King's College Hospital, London SE5
| | - D M J Williams
- BP Chemicals International Ltd, Sully, Penarth, South Glamorgan
| | - P M Smith
- Department of Medicine, Welsh National School of Medicine, Llandough Hospital, Penarth, South Glamorgan
| | - B W Duck
- Occupational Health Unit, BP Research Centre, Sunbury on Thames
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Affiliation(s)
- M Lowrie
- Davies Veterinary Specialists, Manor Farm Business Park, Higham Gobion, Hitchin SG5 3HR, UK
| | - P M Smith
- Davies Veterinary Specialists, Manor Farm Business Park, Higham Gobion, Hitchin SG5 3HR, UK
| | - T De Keuster
- Faculty of Veterinary Medicine, Ghent University, Salisburylaan 133, Merelbeke 9820, Belgium
| | - L Garosi
- Davies Veterinary Specialists, Manor Farm Business Park, Higham Gobion, Hitchin SG5 3HR, UK
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Murtagh K, Arrol L, Goncalves R, Granger N, German AJ, Smith PM. Hypothalamic-anterior pituitary hormone deficiencies following traumatic brain injury in dogs. Vet Rec 2015; 176:20. [PMID: 25200430 DOI: 10.1136/vr.102626] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
Traumatic brain injury is an important cause of hypopituitarism in human beings, but limited information exists in the veterinary literature regarding this condition. The primary study objective was to investigate whether hypothalamic-anterior pituitary axis dysfunction exists following traumatic brain injury in 17 client owned dogs. In this retrospective, observational, open, cohort study, information about dogs presented to four separate referral centres between April 2008 and October 2013 was reviewed. Cases were included if they had suffered from non-fatal traumatic brain injury, resulting in neurological dysfunction, and follow-up evaluation included measurement of the serum concentration of insulin-like growth factor 1 (IGF-1), endogenous adrenocorticotrophic hormone (ACTH), basal cortisol, thyroid-stimulating hormone, total thyroxine (TT4) and, if appropriate, free thyroxine. Decreased IGF-1 concentration was the most common abnormality detected (7/17, 41 per cent; median 132 ng/ml, range <15-536), followed by a decreased TT4 concentration (4/17, 23 per cent; median 19, range 4-49). Basal cortisol concentration was less than 20 nmol/l in two cases (2/17, 12 per cent; median 65, range <20-1735), with concurrently undetectable ACTH (<5 pg/ml). This study demonstrates that dogs with a history of traumatic brain injury can develop endocrine abnormalities indicative of hypothalamic-anterior pituitary dysfunction.
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Affiliation(s)
- K Murtagh
- Department of Veterinary Internal Medicine, Small Animal Teaching Hospital, University of Liverpool, Chester High Road, Neston CH64 7TE, UK
| | - L Arrol
- Cave Veterinary Specialists, George's Farm, West Buckland, Nr. Wellington TA21 9LE, UK
| | - R Goncalves
- Department of Veterinary Internal Medicine, Small Animal Teaching Hospital, University of Liverpool, Chester High Road, Neston CH64 7TE, UK
| | - N Granger
- School of Veterinary Sciences, University of Bristol, Langford House, Langford, North Somerset BS40 5DU, UK
| | - A J German
- Department of Veterinary Internal Medicine, Small Animal Teaching Hospital, University of Liverpool, Chester High Road, Neston CH64 7TE, UK
| | - P M Smith
- Davies Veterinary Specialists, Hertfordshire SG5 3HR, UK
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Gonçalves R, Volk H, Smith PM, Penderis J, Garosi L, MacKillop E, de Stefani A, Cherubini G, McConnell JF. Corpus callosal abnormalities in dogs. J Vet Intern Med 2014; 28:1275-9. [PMID: 24839863 PMCID: PMC4857934 DOI: 10.1111/jvim.12371] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2014] [Revised: 02/25/2014] [Accepted: 04/08/2014] [Indexed: 12/16/2022] Open
Abstract
BACKGROUND Corpus callosal abnormalities (CCA) in dogs have been only sporadically reported and are poorly characterized. HYPOTHESIS/OBJECTIVES To describe the clinical presentation and magnetic resonance imaging (MRI) characteristics of dogs with CCA. ANIMALS Fifteen client-owned dogs. METHODS Retrospective study. Records of the contributing institutions were reviewed to identify dogs diagnosed with malformations affecting the corpus callosum (CC); cases in which the CCA was thought to be secondary were excluded. RESULTS The most represented breeds were Staffordshire Bull Terriers (5/15) and Miniature Schnauzers (3/15; n = 3, 20%) and the mean age at time of presentation of 19 months (range 3-81 months). The clinical signs most commonly reported were adipsia/hypodipsia with associated hypernatremia (12/15), tremors (6/15), and seizures (6/15). Review of the MR images revealed that 10 dogs had absence of the rostral CC and hypoplasia of the caudal portion, 4 dogs had a diffusely hypoplastic and dysplastic CC, and 1 dog had a diffusely hypoplastic CC. In 14 cases, there was abnormal cortical development with fusion of the ventral frontal lobes and part of the diencephalon, indicating lobar holoprosencephaly. CONCLUSIONS AND CLINICAL IMPORTANCE Previous literature has mainly associated CCA with adipsia and only 12 of 15 dogs in the current series demonstrated this abnormality. There are different degrees of the malformation but in 10 dogs the rostral portion of the CC is most severely affected. Fourteen dogs have simultaneous fusion of the midline structures rostral to the CC; this region has several structures involved in thirst regulation and might explain this derangement.
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Affiliation(s)
- R Gonçalves
- Department of Veterinary Science, Small Animal Teaching Hospital, University of Liverpool, Neston, UK
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Abstract
BACKGROUND Relatively few longitudinal studies have explored the relationship between psychosocial work conditions and diabetes incidence. Given the increasing global burden of diabetes this is an important area for public health research. AIMS To examine the relationships between dimensions of the psychosocial work environment on the subsequent incidence of diabetes among men and women in Ontario, Canada over a 9 year period. METHODS We used data from Ontario respondents (35 to 60 years of age) to the 2000-01 Canadian Community Health Survey linked to the Ontario Health Insurance Plan database for physician services and the Canadian Institute for Health Information Discharge Abstract Database for hospital admissions. Our sample of actively employed labour market participants with no previous diagnoses for diabetes was followed for a 9 year period to ascertain incident diabetes. RESULTS There were 7443 participants. Low levels of job control were associated with an increased risk of diabetes among women, but not among men. Counter to our hypotheses high levels of social support were also associated with increased diabetes risk among women, but not among men. No relationship was found between any psychosocial work measure and risk of diabetes among men. CONCLUSIONS Given the increasing prevalence of diabetes worldwide, job control could potentially be an import ant modifiable risk factor to reduce the incidence of diabetes among female, but not among male, workers. More research is needed to understand the pathways through which low social support may protect against the development of diabetes.
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Affiliation(s)
- P M Smith
- Institute for Work & Health Toronto, Ontario, Canada.
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15
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Abstract
The subfornical organ (SFO), a sensory circumventricular organ lacking the normal blood-brain barrier with well documented roles in cardiovascular regulation, has recently been identified as a potential site at which the adipokine, leptin, may act to influence central autonomic pathways. Systemic and central leptin administration has been shown to increase blood pressure and it has been suggested that selective leptin resistance contributes to obesity-related hypertension. Given the relationship between obesity and hypertension, the present study aimed to investigate the cardiovascular consequences of the direct administration of leptin into the SFO of young lean rats and in the diet-induced obesity (DIO) rat model, which has been shown to be leptin-resistant. Leptin administration (500 fmol) directly into the SFO of young rats resulted in rapid decreases in blood pressure (BP) [mean area under the curve (AUC) = -677.8 ± 167.1 mmHg*s; n = 9], without an effect on heart rate (mean AUC = -21.2 ± 13.4 beats; n = 9), and these effects were found to be dose-related as microinjection of 5 pmol of leptin into the SFO had a larger effect on BP (mean AUC = -972.3 ± 280.1 mmHg*s; n = 4). These BP effects were also shown to be site-specific as microinjection of leptin into non-SFO regions or into the ventricle was without effect on BP (non-SFO: mean AUC = -22.4 ± 55.3 mmHg*s; n = 4; ventricle: mean AUC = 194.0 ± 173.0 mmHg*s; n = 6). By contrast, microinjection of leptin into leptin-resistant DIO rats was without effect on BP (mean AUC = 205.2 ± 75.1 mmHg*s; n = 4). These observations suggest that the SFO may be an important relay centre through which leptin, in normal weight, leptin responsive rats, acts to maintain BP within normal physiological limits through descending autonomic pathways involved in cardiovascular control and that, in obese, leptin-resistant, rats leptin no longer influences SFO neurones, resulting in an elevated BP, thus contributing to obesity-related hypertension.
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Affiliation(s)
- P M Smith
- Department of Physiology, Queen's University, Kingston, Ontario, Canada
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Gilbert P, Al-Hiti MM, Smith PM. Evaluation of a New Disinfectant-Cleanser Developed for use in Fibreoptic Endoscopy. J Pharm Pharmacol 2011. [DOI: 10.1111/j.2042-7158.1981.tb11729.x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- P Gilbert
- Department of Pharmacy, University of Manchester, Manchester M13 9PL
| | - MM Al-Hiti
- Department of Pharmacy, University of Manchester, Manchester M13 9PL
| | - PM Smith
- Department of Pharmacy, University of Manchester, Manchester M13 9PL
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Affiliation(s)
- K Robson
- Small Animal Teaching Hospital, University of Liverpool, Leahurst, Chester High Road, Neston, Cheshire CH64 7TE
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18
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Clarkson DJ, Smith PM, Thorpe RJ, Daly JC. The use of custom-made external nipple-areolar prostheses following breast cancer reconstruction. J Plast Reconstr Aesthet Surg 2011; 64:e103-5. [PMID: 21277268 DOI: 10.1016/j.bjps.2010.12.016] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2010] [Revised: 10/26/2010] [Accepted: 12/28/2010] [Indexed: 10/18/2022]
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Smith PM, Chen C, Mustard C. Differential risk of employment in more physically demanding jobs among a recent cohort of immigrants to Canada. Inj Prev 2010; 15:252-8. [PMID: 19651999 DOI: 10.1136/ip.2008.021451] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
OBJECTIVE To examine the proportion of a recent cohort of immigrants to Canada who were working in jobs that were more physically demanding than those in which they worked before migration to Canada. DESIGN Longitudinal cohort of immigrants to Canada with occupational position measured before and 2 and 4 years after arrival in Canada. SUBJECTS Respondents to Statistics Canada's Longitudinal Survey of Immigrants to Canada (LSIC). The LSIC surveyed a representative sample of immigrants, aged 15 and older, who arrived in Canada between November 2000 and December 2001. For the purpose of this study, the sample was restricted to respondents who had worked before immigrating and were working when re-interviewed 2 (n = 4331) or 4 (n = 4238) years after arrival in Canada. MAIN OUTCOME Employment in an occupation with higher physical demands than that employed in before arrival in Canada. RESULTS Respondents with less proficiency at speaking English and family class or refugee applicants were the most likely to be employed in occupations with higher physical demands both 2 and 4 years after arrival in Canada. CONCLUSIONS Employment in a more physically demanding occupation may pose particular risks of workplace injury. In this sample of immigrants to Canada, respondents with poorer English skills and refugees (factors that may increase this risk) were more likely to be employed in more physically demanding occupations. Greater attention to the prevention of workplace injuries among particular groups of new immigrants to Canada is required.
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Affiliation(s)
- P M Smith
- Institute For Work & Health, Toronto, ON M5G 2E9, Canada.
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el-Alfi OS, Smith PM, Biesele JJ. Chromosomal breaks in human leucocyte cultures induced by an agent in the plasma of infectious hepatitis patients. Hereditas 2009; 52:285-94. [PMID: 5828747 DOI: 10.1111/j.1601-5223.1965.tb01961.x] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023] Open
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Stalin CE, Pratt JNJ, Smith PM, Jeffery ND. Thoracic stenosis causing lateral compression of the spinal cord in two immature Dogues de Bordeaux. Vet Comp Orthop Traumatol 2009; 22:59-62. [PMID: 19151872] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
This case report describes a novel developmental vertebral malformation in two young Dogues de Bordeaux, which was diagnosed by magnetic resonance imaging. Both dogs were treated surgically with reasonable success.
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Affiliation(s)
- C E Stalin
- Department Veterinary Medicine, University of Cambridge, Madingley Road, Cambridge, CB3 0ES, UK.
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Smith PM, Chambers AP, Price CJ, Ho W, Hopf C, Sharkey KA, Ferguson AV. The subfornical organ: a central nervous system site for actions of circulating leptin. Am J Physiol Regul Integr Comp Physiol 2008; 296:R512-20. [PMID: 19020290 DOI: 10.1152/ajpregu.90858.2008] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Adipose tissue plays a critical role in energy homeostasis, secreting adipokines that control feeding, thermogenesis, and neuroendocrine function. Leptin is the prototypic adipokine that acts centrally to signal long-term energy balance. While hypothalamic and brain stem nuclei are well-established sites of action of leptin, we tested the hypothesis that leptin signaling occurs in the subfornical organ (SFO). The SFO is a circumventricular organ (CVO) that lacks the normal blood-brain barrier, is an important site in central autonomic regulation, and has been suggested to have a role in modulating peripheral signals indicating energy status. We report here the presence of mRNA for the signaling form of the leptin receptor in SFO and leptin receptor localization by immunohistochemistry within this CVO. Central administration of leptin resulted in phosphorylation of STAT3 in neurons of SFO. Whole cell current-clamp recordings from dissociated SFO neurons demonstrated that leptin (10 nM) influenced the excitability of 64% (46/72) of SFO neurons. Leptin was found to depolarize the majority of responsive neurons with a mean change in membrane potential of 7.3 +/- 0.6 mV (39% of all SFO neurons), while the remaining cells that responded to leptin hyperpolarized (-6.9 +/- 0.7 mV, 25% of all SFO neurons). Similar depolarizing and hyperpolarizing effects of leptin were observed in recordings from acutely prepared SFO slice preparations. Leptin was found to influence the same population of SFO neurons influenced by amylin as three of four cells tested for the effects of bath application of both amylin and leptin depolarized to both peptides. These observations identify the SFO as a possible central nervous system location, with direct access to the peripheral circulation, at which leptin may act to influence hypothalamic control of energy homeostasis.
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Affiliation(s)
- P M Smith
- Dept of Physiology, Queen's Univ., Kingston, Ontario, Canada K7L 3N6
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Smith PM, Frank JW, Mustard CA, Bondy SJ. Examining the relationships between job control and health status: a path analysis approach. J Epidemiol Community Health 2008; 62:54-61. [PMID: 18079334 DOI: 10.1136/jech.2006.057539] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
OBJECTIVE To examine the pathways through which job control affects health status; to examine if the effects of job control on health status are attenuated by including other measures associated with lower socioeconomic status, and to examine if the relationship between job control and health status is consistent across socioeconomic status groups. DESIGN A prospective observational cohort study over eight years (1994-2002). PARTICIPANTS 4886 Respondents aged 25-60 years, who were non-self-employed labour force participants, working more than 20 hours per week, without physical or mental limitations restricting the type or amount of work they could do at baseline. After longitudinal attrition, the remaining study sample was 3411 (87% of the original study sample who did not die or become pregnant during the survey period). MAIN RESULTS Low job control in 1994 was associated with worse than expected self-rated health in 2002, both directly and indirectly via a lower physical activity level in 1996. Adjustment for other factors associated with low socioeconomic status did not attenuate these relationships to a large extent. No differences were found in the effects of job control on physical activity or health status between socioeconomic groups (high and low education and high and low household income). CONCLUSIONS The inclusion of other factors associated with lower socioeconomic status did not attenuate the direct and indirect effects of job control on health status. The finding that low job control is associated with lower physical activity levels deserves further investigation, given the increasing concern about rising levels of obesity in the developed world.
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Affiliation(s)
- P M Smith
- Institute for Work & Health, Toronto, ON, Canada.
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Smith PM, Mustard CA. Comparing the risk of work-related injuries between immigrants to Canada and Canadian-born labour market participants. Occup Environ Med 2008; 66:361-7. [PMID: 18614627 DOI: 10.1136/oem.2007.038646] [Citation(s) in RCA: 66] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
OBJECTIVES To examine the burden of work-related injuries among immigrants to Canada compared to Canadian-born labour force participants. METHODS Using data from the 2003 and 2005 Canadian Community Health Surveys (n = 99,115), two nationally representative population samples, we examined the risk of self-reported, activity limiting work-related injuries among immigrants with varying time periods since arrival in Canada. Models were adjusted for hours of work in the last 12 months as well as various demographic and work-related variables. RESULTS Immigrant men in their first 5 years in Canada reported lower rates of activity limiting injuries compared to Canadian-born respondents. Surprisingly, the percentage of injuries that required medical attention was much higher among recent immigrants compared to Canadian-born respondents, resulting in an increased risk of activity limiting injuries requiring medical attention among immigrant men compared to Canadian-born labour force participants. No excess risk was found among female immigrants compared to Canadian-born female labour market participants. CONCLUSIONS Immigrant men in their first 5 years in Canada are at increased risk of work-related injuries that require medical attention. A similar risk is not present among immigrant women. Further, given differences in the number of activity limiting injuries requiring medical attention across immigrant groups, we believe this excess risk among immigrant men may be underestimated in the current data source. Future research should attempt to fully capture the barriers faced by immigrants in obtaining safe employment, the number of injuries that are sustained by immigrants while working, and the consequences of these injuries.
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Affiliation(s)
- P M Smith
- Institute for Work & Health, 481 University Ave, Suite 800, Toronto, ON, Canada
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Smith PM, Talbot CE, Jeffery ND. Findings on low-field cranial MR images in epileptic dogs that lack interictal neurological deficits. Vet J 2008; 176:320-5. [PMID: 17499532 DOI: 10.1016/j.tvjl.2007.03.003] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2006] [Revised: 03/09/2007] [Accepted: 03/12/2007] [Indexed: 11/26/2022]
Abstract
Recurrent seizuring is a common neurological problem in dogs and can present diagnostic difficulties for the attending clinician. Associated interictal neurological deficits strongly suggest brain disease but the frequency of structural abnormalities in patients without such deficits is unknown. In this study the prevalence of clinically significant magnetic resonance imaging (MRI) abnormalities was determined in two groups of interictally normal dogs, those younger than 6 years and those older than 6 years of age. In the former group, only 1/46 dogs (2.2%) had significant MRI abnormalities, whereas in the latter group, 8/30 (26.7%) were abnormal. None of the dogs had an identifiable metabolic cause for the seizures. These findings suggest that the diagnostic yield of advanced neuroimaging techniques in young seizuring dogs without interictal neurological deficits is low, but reaffirms their value in similar older individuals.
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Affiliation(s)
- P M Smith
- Department of Veterinary Medicine, University of Cambridge, Madingley Road, Cambridge, UK.
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Abstract
Antiperspirant compositions have traditionally relied upon aluminium-based active compounds to reduce sweating. Titanium is a physiologically inert metal, and titanium metal chelates appear to induce superficial physical pore blockage to provide effective antiperspirancy in a variety of product types. Titanium metal chelates can be formed from titanium alkoxides and organic acids. Conflicting opinions as to the salt structure exist and, in the case of part-neutralized ammonium titanium lactate (ATL) salt, evidence has been seen for a range of ligands bound to different strengths at different stages of hydrolysis. Aluminium is thought to work by ductal diffusion to give antiperspirancy via neutralization to a polymeric, relatively superficial gel obstruction. ATL mimics conventional alumiunium salts in that it is mainly a topical antiperspirant active, with ATL-treated skin restored to normal patterns of sweating activity after a few tape-strips. Under acidic and near-neutral pH conditions, the ATL active is relatively stable to hydrolysis and can be formulated into topical compositions as either an aqueous solution of the active or as a free-flowing powder in anhydrous systems. When judged by an in vitro efficacy technique which is thought to predict in vivo performance, ATL functions as an effective antiperspirant.
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Affiliation(s)
- D B Hagan
- Unilever Research Port Sunlight Laboratory, Bebington, Wirral UK
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Smith PM, Haughland SP, Jeffery ND. Brain abscess in a dog immunosuppressed using cyclosporin. Vet J 2007; 173:675-8. [PMID: 16690333 DOI: 10.1016/j.tvjl.2006.01.014] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2005] [Revised: 01/11/2006] [Accepted: 01/13/2006] [Indexed: 01/18/2023]
Abstract
This report describes a dog that developed brain abscesses following prolonged immunosuppression with cyclosporin. Bacteria within the abscess were most likely Nocardia, an organism well recognised in immunosuppressed humans, and probably reached the brain through haematogenous spread from a more long-standing abscess in the mediastinum. Bacterial brain abscesses developing in this manner are very rare in dogs and this case highlights the wider range of possible diagnoses that need to be considered in immunosuppressed patients and the care with which potent drugs such as cyclosporin should be used.
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Affiliation(s)
- P M Smith
- Department of Veterinary Medicine, University of Cambridge, Madingley Road, Cambridge, CB3 0ES, UK.
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Abstract
Orexin-A is a neuropeptide, primarily produced in the lateral hypothalamic/perifornical hypothalamus. Orexin receptors and immunoreactive neuronal fibres are widely distributed throughout the brain, suggesting integrative neurotransmitter roles in a variety of physiological systems. Intracerebroventricular injections of orexin-A increase blood pressure and stimulate drinking, and the subfornical organ (SFO), a circumventricular structure implicated in autonomic control, is a potential site at which orexin may act to exert these effects. We have therefore used microinjection techniques to examine the effects of orexin-A administered directly into the SFO on blood pressure and heart rate in urethane anaesthetised male Sprague-Dawley rats. Orexin-A microinjection (50 fmol) into the SFO caused site-specific decreases in blood pressure (SFO: mean area under curve (AUC) = -681.7 +/- 46.8 mmHg*s, n = 22 versus non-SFO: 63.68 +/- 54.69 mmHg*s, n = 15, P < 0.001), and heart rate (SFO: mean AUC = -26.7 +/- 2.8 beats, n = 22, versus non-SFO: mean AUC = 1.62 +/- 2.1 beats, n = 15, P < 0.001). Vagotomy did not alter the hypotensive or bradycardic responses elicited by orexin-A microinjection. Prior alpha-adrenoceptor blockade with phenoxybenzamine (1 mg/kg, i.v.) masked the orexin-A induced blood pressure (mean AUC = -122.6 +/- 17.6 mmHg*s, n = 4, P < 0.01 paired t-test) and heart rate (mean AUC = -6.7 +/- 1.7 beats, n = 4, P < 0.05, paired test) response. The orexin-A induced heart rate response was attenuated when beta-adrenoceptors were blocked with propranolol (1 mg/kg, i.v.; mean AUC = 0.6 +/- 2.8 beats, n = 5, P < 0.01 paired t-test). These studies demonstrate that microinjection of orexin-A into the SFO causes site specific decreases in blood pressure and heart rate which is mediated by a reduction in sympathetic tone.
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Affiliation(s)
- P M Smith
- Department of Physiology, Queen's University, Kingston, Ontario, Canada
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Abstract
The principal aim of this study was to examine how different ramp rates influenced the attainment of peak physiological responses during incremental arm crank ergometry (ACE). Additionally, the study examined whether there was any evidence for the development of an "excess" VO (2) during ACE due to upward curvi-linearity in the VO (2)-work rate relationship, and whether this was influenced by the ramp rate. Sixteen physically active, though non-specifically trained, men (mean +/- S age 30 +/- 8 years; height 1.79 +/- 0.07 m; body mass 84.7 +/- 13.2 kg) volunteered to participate. Having completed a familiarisation test, all subjects returned to the laboratory to complete two ramp tests on an electrically-braked ergometer in a counter-balanced order. Both ramp tests started at 60 W with work rate subsequently incremented by either 6 or 12 W . min (-1). Pulmonary gas exchange was measured breath-by-breath throughout the tests. Subjects achieved a greater final work rate during the 12 W . min (-1) test compared to the 6 W . min (-1) test (168 +/- 28 vs. 149 +/- 26 W; p < 0.001). The VO (2peak) (3.06 +/- 0.65 vs. 2.96 +/- 0.48 L . min (-1); p = 0.27), HR (peak) (179 +/- 15 vs. 177 +/- 16 b . min (-1); p = 0.17) and V.E (peak) (112 +/- 22 vs. 105 +/- 16 L . min (-1); p = 0.09) were not different between the tests, but VCO (2peak) (3.54 +/- 0.64 vs. 3.27 +/- 0.46 L . min (-1); p = 0.01) RER (peak) (1.17 +/- 0.07 vs. 1.11 +/- 0.06; p < 0.001), and end-exercise blood (lactate) (11.9 +/- 2.1 vs. 10.8 +/- 2.6 mmol . L (-1); p = 0.005) were all higher in the 12 W . min (-1) test. An "excess" VO (2) was observed in 13 out of 16 tests at 12 W . min (-1) and in 15 out of 16 tests at 6 W . min (-1). Neither the magnitude of the "excess" VO (2) (0.42 +/- 0.41 vs. 0.37 +/- 0.18 L . min (-1); p = 0.66) nor the VO (2) at which the V.O (2)-work rate relationship departed from linearity (2.17 +/- 0.34 vs. 2.18 +/- 0.32 L . min (-1); p = 0.94) were significantly different between the two ramp tests. These data indicate that differences in ramp rate within the range of 6 - 12 W . min (-1) influence the peak values of work rate, VCO (2) and RER, but do not influence peak values of VO (2) or HR during ACE. The development of an "excess" VO (2) appears to be a common feature of ramp exercise in ACE, although the mechanistic basis for this effect is presently unclear.
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Affiliation(s)
- P M Smith
- Centre for Sport and Exercise Science, University of Greenwich, Chatham, Kent, UK.
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Smith PM, Doherty M, Price MJ. The effect of crank rate on physiological responses and exercise efficiency using a range of submaximal workloads during arm crank ergometry. Int J Sports Med 2006; 27:199-204. [PMID: 16541375 DOI: 10.1055/s-2005-837620] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
Abstract
This study examined the effects of variations in crank rate on physiological responses during submaximal arm ergometry. Fifteen non-specifically trained male subjects volunteered to participate in this study. Each subject undertook a discontinuous arm crank ergometry test (30, 50, 70, 90 W) on three separate occasions using crank rates of 50, 70, and 90 rev.min(-1). Respiratory parameters and heart rate were continuously monitored. An 80-microL capillary blood sample was obtained immediately following each exercise bout for the determination of whole blood lactate. Measures of efficiency were calculated using specific caloric equivalents of oxygen consumption (V(O2)). Heart rate was lowest (p < 0.05) at 30, 50, and 70 W using 50 rev.min(-1). Values of gross and net efficiency tended to be higher (p < 0.05) using 50 rev.min (-1) at the lower absolute workloads, but no differences (p > 0.05) were observed between the three crank rates at 90 W. No differences (p > 0.05) were observed between crank rates for delta efficiency. This study confirms that variations in crank rate can influence gross and net values of V(O2) and exercise efficiency at low absolute workloads, but crank rate ceases to be an influential factor at moderate workloads. Further research is required to identify the specific mechanisms underpinning the observations reported in the present study relating to the interaction between crank rate, workload, and exercise efficiency during arm crank ergometry.
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Affiliation(s)
- P M Smith
- Center of Sport and Exercise Science, University of Greenwich, Chatham Maritime, Kent, United Kingdom.
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Affiliation(s)
- G L Walmsley
- Department of Veterinary Medicine, University of Cambridge, Madingley Road, Cambridge CB3 0ES
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Dawson LJ, Stanbury J, Venn N, Hasdimir B, Rogers SN, Smith PM. Antimuscarinic antibodies in primary Sjögren's syndrome reversibly inhibit the mechanism of fluid secretion by human submandibular salivary acinar cells. ACTA ACUST UNITED AC 2006; 54:1165-73. [PMID: 16572451 DOI: 10.1002/art.21764] [Citation(s) in RCA: 111] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
OBJECTIVE Sjögren's syndrome (SS) is an autoimmune condition affecting salivary glands, for which a clearly defined pathogenic autoantibody has yet to be identified. Autoantibodies that bind to the muscarinic M3 receptors (M3R), which regulate fluid secretion in salivary glands, have been proposed in this context. However, there are no previous data that directly show antisecretory activity. This study was undertaken to investigate and characterize the antisecretory activity of anti-M3R. METHODS Microfluorimetric Ca2+ imaging and patch clamp electrophysiologic techniques were used to measure the secretagogue-evoked increase in [Ca2+]i and consequent activation of Ca2+-dependent ion channels in individual mouse and human submandibular acinar cells. Together, these techniques form a sensitive bioassay that was used to determine whether IgG isolated from patients with primary SS and from control subjects has antisecretory activity. RESULTS IgG (2 mg/ml) from patients with primary SS reduced the carbachol-evoked increase in [Ca2+]i in both mouse and human acinar cells by approximately 50%. IgG from control subjects had no effect on the Ca2+ signal. Furthermore, the inhibitory action of primary SS patient IgG on the Ca2+ signal was acutely reversible. We repeated our observations using rabbit serum containing antibodies raised against the second extracellular loop of M3R and found an identical pattern of acutely reversible inhibition. Anti-M3R-positive serum had no effect on Ca2+-dependent ion channel activation evoked by the direct intracellular infusion of inositol 1,4,5-triphosphate. CONCLUSION These observations show for the first time that IgG from patients with primary SS contains autoantibodies capable of damaging saliva production and contributing to xerostomia. The unusual but not unprecedented acute reversibility of the effects of anti-M3 autoantibodies is the subject of further research.
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Affiliation(s)
- L J Dawson
- The University of Liverpool, and Aintree Hospitals, Liverpool, UK.
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Affiliation(s)
- L J Dawson
- Oral Surgery, University of Liverpool Dental School, Room 1.10, Edwards Building, Daulby Street, Liverpool L69 3GN, UK.
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Affiliation(s)
- P M Smith
- Department of Veterinary Medicine, University of Cambridge, Madingley Road, Cambridge CB3 0ES
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Jeffery ND, Smith PM, Lakatos A, Ibanez C, Ito D, Franklin RJM. Clinical canine spinal cord injury provides an opportunity to examine the issues in translating laboratory techniques into practical therapy. Spinal Cord 2006; 44:584-93. [PMID: 16520817 DOI: 10.1038/sj.sc.3101912] [Citation(s) in RCA: 84] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
STUDY DESIGN Review. OBJECTIVES To highlight the value of investigating the effects of putative therapeutic interventions in clinical spinal cord injury (SCI) in domestic dogs. SETTING England, UK. METHODS Many experimental interventions in laboratory rodents have been shown to ameliorate the functional deficits caused by SCI; the challenge now is to determine whether they can be translated into useful clinical techniques. Important differences between clinical SCI in human patients and that in laboratory rodents are in the size of the spinal cord and heterogeneity of injury severity. A further key issue is whether the statistical difference in outcome in the laboratory will translate into a useful difference in clinical outcome. Here, we stress the value of investigating the effects of putative therapies in clinical SCI in domestic dogs. The causes of injury, ability to categorise the severity and methods available to measure outcome are very similar between canine and human patients. Furthermore, postmortem tissue more rapidly becomes available from dogs because of their short lifespan than from human patients. RESULTS The role that investigation of canine SCI might play is illustrated by our preliminary trials on intraspinal transplantation of olfactory glial cells for severe SCI. CONCLUSIONS This canine translational model provides a means of 'filtering' putative treatments before human application.
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Affiliation(s)
- N D Jeffery
- Department of Veterinary Medicine, University of Cambridge, Cambridge, UK
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Jeffery ND, Talbot CE, Smith PM, Bacon NJ. Acquired idiopathic laryngeal paralysis as a prominent feature of generalised neuromuscular disease in 39 dogs. Vet Rec 2006; 158:17. [PMID: 16400098 DOI: 10.1136/vr.158.1.17] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
A retrospective evaluation of 17 dogs treated surgically for idiopathic acquired laryngeal paralysis demonstrated a marked variability in outcome, with many dogs continuing to exhibit weakness and exercise tolerance. In a subsequent prospective study, 22 consecutive affected dogs were tested for neurological deficits by neurological examination, electrodiagnostic evaluation, and blood analysis to measure thyroxine and thyroid-stimulating hormone and to detect any evidence of myasthenia gravis. Clinical neurological deficits and/or electrodiagnostic abnormalities were found in each case. There was limited evidence that specific neurological deficits were associated with a poor prognosis for full recovery of exercise tolerance. None of the dogs was positive for anti-acetylcholine receptor antibodies, and only three showed evidence of thyroid dysfunction.
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Affiliation(s)
- N D Jeffery
- Department of Veterinary Medicine, University of Cambridge, Madingley Road, Cambridge CB3 0ES, UK
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Abstract
Spinal shock is the loss of muscle tone and segmental spinal reflexes that develops caudal to a severe spinal cord injury. Although little recognized in the veterinary literature, spinal shock occurs in animals and is important in both accurate lesion localization and case management. In this review, we consider why spinal shock occurs and discuss the subsequent physiologic alterations, including the development of reflex hyperactivity. We also discuss differences in the expression of spinal shock between species and suggest why recovery of reflexes is relatively rapid in animals compared with humans. Finally, the implications for clinicians dealing with animals in the period immediately after severe spinal injury are considered.
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Affiliation(s)
- P M Smith
- Department of Clinical Veterinary Medicine, Madingley Rd, Cambridge CB3 0ES, UK.
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Abstract
The purpose of this study was to use the meta-analytic approach to examine the effects of caffeine ingestion on ratings of perceived exertion (RPE). Twenty-one studies with 109 effect sizes (ESs) met the inclusion criteria. Coding incorporated RPE scores obtained both during constant load exercise (n=89) and upon termination of exhausting exercise (n=20). In addition, when reported, the exercise performance ES was also computed (n=16). In comparison to placebo, caffeine reduced RPE during exercise by 5.6% (95% CI (confidence interval), -4.5% to -6.7%), with an equivalent RPE ES of -0.47 (95% CI, -0.35 to -0.59). These values were significantly greater (P<0.05) than RPE obtained at the end of exercise (RPE % change, 0.01%; 95% CI, -1.9 to 2.0%; RPE ES, 0.00, 95% CI, -0.17 to 0.17). In addition, caffeine improved exercise performance by 11.2% (95% CI; 4.6-17.8%). Regression analysis revealed that RPE obtained during exercise could account for approximately 29% of the variance in the improvement in exercise performance. The results demonstrate that caffeine reduces RPE during exercise and this may partly explain the subsequent ergogenic effects of caffeine on performance.
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Affiliation(s)
- M Doherty
- Division of Sport and Exercise Science, University of Luton, Luton, Beds LU1 3JU, UK.
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Smith PM, Doherty M, Drake D, Price MJ. The influence of step and ramp type protocols on the attainment of peak physiological responses during arm crank ergometry. Int J Sports Med 2005; 25:616-21. [PMID: 15532006 DOI: 10.1055/s-2004-817880] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
The present study examined the impact of two exercise protocols on the attainment of peak physiological responses during arm crank ergometry (ACE). Fourteen physically active, although non-specifically trained male subjects completed two V.O (2) peak tests using an electrically braked arm ergometer (Lode Angio, Groningen, Netherlands). The tests consisted of a stepwise or rampwise increase in external workload. The order of tests was randomised and each test was separated by at least two days. Respiratory data were collected continuously using an on-line gas analysis system with sample time set at 30 s. Fingertip capillary blood samples ( approximately 20 microL) were collected at volitional exhaustion and at minute intervals for 7 min of passive recovery for the determination of peak whole blood lactate concentration. Time on the test (T (lim); s), peak minute power (PMP; W), and total work done (TWD; kJ) were also recorded. In addition to determining systematic bias using separate independent t-tests, the level of agreement was also examined by way of calculating the 95 % limits of agreement. Sub-maximal values of V.O (2), V.E, and HR were similar (p > 0.05) between test when the amount of external work completed was taken into consideration. There was no systematic bias (p > 0.05) for mean (+/- s) peak values of V.O (2) (3.12 [0.37] vs. 3.04 [0.38] L . min (-1)) or any other parameter between the step and ramp tests, respectively. Mean values of T (lim), PMP, and TWD were also similar (p > 0.05) between tests. However, the level of agreement for peak values of all test parameters was low. It is therefore concluded that while either test can be considered as being suitable for the purpose of eliciting V.O (2) peak and other physiological responses using ACE, they should not be used interchangeably for the purpose of assessing parameters linked to the aerobic capacity of the upper-body.
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Affiliation(s)
- P M Smith
- Department of Sport, Exercise and Biomedical Sciences, University of Luton, United Kingdom.
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Dawson LJ, Caulfield VL, Stanbury JB, Field AE, Christmas SE, Smith PM. Hydroxychloroquine therapy in patients with primary Sjogren's syndrome may improve salivary gland hypofunction by inhibition of glandular cholinesterase. Rheumatology (Oxford) 2005; 44:449-55. [PMID: 15590764 DOI: 10.1093/rheumatology/keh506] [Citation(s) in RCA: 63] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
OBJECTIVE To determine whether (i) cholinesterase activity is increased in the saliva of patients with primary Sjogren's syndrome (pSS), (ii) increased levels of cholinesterase of lymphocyte origin could interfere with the secretory activity of submandibular acinar cells, and (iii) hydroxychloroquine at therapeutic doses could interfere with cholinesterase activity. METHODS The Ellman method was used to determine the levels of salivary cholinesterase activity and the K(i) of both chloroquine and hydroxychloroquine for serum cholinesterase. The ability of lymphocyte cholinesterase to inhibit the acetylcholine (ACh)-evoked rise in [Ca(2+)](i) in mouse submandibular acinar cells was determined using fura-2 microfluorimetry. RESULTS Patients with pSS had significantly higher levels of cholinesterase activity in both their unstimulated (P < 0.05) and stimulated saliva (P < 0.0001) compared with control subjects. Lymphocyte cholinesterase was capable of inhibiting the ACh-evoked rise in [Ca(2+)](i). The in vitro K(i) for hydroxychloroquine inhibition of cholinesterase was 0.38 +/- 1.4 microM. CONCLUSION These data suggest that increased levels of cholinesterase present in the salivary glands of patients with pSS may contribute to glandular hypofunction and provide evidence that the therapeutic enhancement of salivary secretion in patients with pSS by hydroxychloroquine may be mediated by inhibition of glandular cholinesterase activity, although further in vivo investigation is needed.
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Affiliation(s)
- L J Dawson
- Clinical Dental Sciences, University of Liverpool, UK.
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Lucía A, Balmer J, Davison RCR, Pérez M, Santalla A, Smith PM. Effects of the rotor pedalling system on the performance of trained cyclists during incremental and constant-load cycle-ergometer tests. Int J Sports Med 2005; 25:479-85. [PMID: 15459827 DOI: 10.1055/s-2004-820941] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
The aim of this study was to determine the effects of Rotor, a new cycle crank configuration that effectively allows the pedals to move independently throughout the duty cycle, on indices of endurance cycling performance in trained cyclists. Ten cyclists (5 Rotor users and 5 non-users; age (mean +/- SD): 22 +/- 5 y; VO(2)max: 69.5 +/- 5.1 mL. kg(-1).min(-1)) volunteered to participate in the study. On four separate days, the subjects performed four cycle-ergometer tests, i.e. two incremental tests and two 20-min tests. An imposed crank rate of 75 rev.min(-1) was used during all tests. The incremental protocol started at 112.5 W, and the power output was increased by 37.5 W every 3 min until volitional exhaustion. The 20-min tests were performed at a fixed power output equivalent to 80 % of the highest power output that the cyclists maintained for a complete 3-min period during incremental tests. Both types of tests were performed with the conventional crank system and the Rotor following a counter-balanced, cross-over design. Gas exchange parameters were measured in all the tests and blood lactate was determined at the end of each 3-min period (incremental tests) and at the end of the 20-min tests. A three factor (pedalling system used during the tests x habitual pedalling system x power output [incremental tests] or time [20-min tests]) ANOVA with repeated measures on power output (incremental tests) or time (20-min tests) was used to analyse several indices of performance, e.g. peak power output, VO(2)max, lactate threshold, onset of blood lactate accumulation, economy, delta, and gross efficiency. No differences (p > 0.05) were found between the Rotor and conventional systems for any of the aforementioned variables. It seems that the theoretical advantage brought about by the Rotor system, i.e. improved contra-lateral cooperation of both legs, would be minimized in trained cyclists. Although field studies are needed to assess the possible implications, in terms of actual racing, of the new system, commonly used indicators of endurance cycling performance do not seem to be improved with the Rotor in trained cyclists.
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Affiliation(s)
- A Lucía
- Facultad de Ciencias de la Actividad Física y el Deporte, Universidad Europea de Madrid, 28670 Madrid, Spain.
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Harmer AR, Smith PM, Gallacher DV. Local and global calcium signals and fluid and electrolyte secretion in mouse submandibular acinar cells. Am J Physiol Gastrointest Liver Physiol 2005; 288:G118-24. [PMID: 15308468 DOI: 10.1152/ajpgi.00096.2004] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Polarized Ca(2+) signals that originate at and spread from the apical pole have been shown to occur in acinar cells from lacrimal, parotid, and pancreatic glands. However, "local" Ca(2+) signals, that are restricted to the apical pole of the cell, have been previously demonstrated only in pancreatic acinar cells in which the primary function of the Ca(2+) signal is to regulate exocytosis. We show that submandibular acinar cells, in which the primary function of the Ca(2+) signal is to drive fluid and electrolyte secretion, are capable of both Ca(2+) waves and local Ca(2+) signals. The generally accepted model for fluid and electrolyte secretion requires simultaneous Ca(2+)-activation of basally located K(+) channels and apically located Cl(-) channels. Whereas a propagated cell-wide Ca(2+) signal is clearly consistent with this model, a local Ca(2+) signal is not, because there is no increase in intracellular Ca(2+) concentration at the basal pole of the cell. Our data provide the first direct demonstration, in submandibular acinar cells, of the apical and basal location of the Cl(-) and K(+) channels, respectively, and confirm that local Ca(2+) signals do not Ca(2+)-activate K(+) channels. We reevaluate the model for fluid and electrolyte secretion and demonstrate that Ca(2+)-activation of the Cl(-) channels is sufficient to voltage-activate the K(+) channels and thus demonstrate that local Ca(2+) signals are sufficient to support fluid secretion.
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Affiliation(s)
- A R Harmer
- Clinical Dental Sciences, The University of Liverpool, Liverpool L69 3GN, UK
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Smith PM, Mustard CA. Examining the associations between physical work demands and work injury rates between men and women in Ontario, 1990-2000. Occup Environ Med 2004; 61:750-6. [PMID: 15317915 PMCID: PMC1763671 DOI: 10.1136/oem.2003.009860] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
AIMS To describe the decline in injury rates between 1990 and 2000 within occupations stratified across three levels of physical demands and gender, adjusting for industry, in Canada's largest province. METHODS Records of injury compensation claims were obtained from the Ontario Workplace Safety & Insurance Board. The population likely to be insured by the Ontario Workplace Safety & Insurance Board was estimated from Statistics Canada's Labour Force Survey. Injury rates were calculated by three broad levels of physical demands, separately for men and women. RESULTS Injury rates decreased across each grouping of lower physical demands at work for both men and women, with the largest absolute differences in manual occupational groups (high physical demands). Occupations classified as manual (high physical demands) and mixed (moderate physical demands) showed larger differences in injury rates between genders than did non-manual (low physical demands), although the directions of these differences were not always consistent across different natures of injury classification. CONCLUSIONS The absolute reduction in injury rates in Ontario between 1990 and 2000 was dominated by the reduction in injury rates for men and women in manual and mixed occupations. However, not all types of injury have declined to the same extent. A large proportion of differences in injury rates between men and women can be attributed to the differential labour force participation across occupations and industries, as well as the differential tasks within occupational groups.
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Affiliation(s)
- P M Smith
- Institute for Work & Health, 481 University Ave, Suite 800, Toronto, ON, Canada M5G 2E9.
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Dawson LJ, Allison HE, Stanbury J, Fitzgerald D, Smith PM. Putative anti-muscarinic antibodies cannot be detected in patients with primary Sjogren's syndrome using conventional immunological approaches. Rheumatology (Oxford) 2004; 43:1488-95. [PMID: 15353609 DOI: 10.1093/rheumatology/keh389] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
OBJECTIVE To determine whether autoantibodies directed against muscarinic M3 receptors are present in the serum of patients with primary Sjogren's syndrome (pSS), and if so whether these autoantibodies inhibit secretion by intact salivary acinar cells. METHODS IgG was purified by affinity chromatography using protein G from sera collected from 15 patients with pSS. Antibody detection was by Western blotting, whole-cell enzyme-linked immunosorbent assay (ELISA) and immunoblotting. The antisecretory activity of the IgG faction was determined using fura-2 microfluorimetry to measure changes in intracellular Ca(2+) activity ([Ca(2+)](i)) in human and mouse salivary gland acinar cells and in Chinese hamster ovary (CHO) cells transfected with human M3 receptors (CHO-M3). RESULTS We found no specific M3 receptor recognition by the IgG fraction obtained from pSS patients using either Western blotting or ELISA or immunoblot techniques in which epitope conformation were preserved. Chronic exposure to pSS IgG had no effect on agonist-evoked Ca(2+) signals measured in human or mouse submandibular acinar cells or in CHO-M3 cells. However, acute application of IgG from Sjogren's syndrome patients produced a rapidly reversible reduction in the agonist-stimulated elevation in [Ca(2+)](i). CONCLUSION These data represent the first demonstration of salivary acinar cell inhibition by pSS IgG; however, this inhibition was found to be reversible. Our data also show that pSS IgG binding to M3R cannot be visualized by conventional immunological approaches.
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Affiliation(s)
- L J Dawson
- Clinical Dental Sciences, University of Liverpool, Liverpool, UK.
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Abstract
Most fitness assessments either use a constant load to exhaustion (exercise capacity test) or an "all-out" effort (performance test). The purpose of this study was to determine the reliability of a high-intensity assessment that combined a constant load element with a performance test. Ten moderately trained male cyclists completed a ramp test to voluntary exhaustion in order to measure maximum minute power output (mean +/- s, 349.3 w +/- 55.0 w). On two other occasions subjects cycled at a constant load at maximum minute power output for 2-min immediately followed by a 1-min performance test. All tests were conducted on the subjects' own bicycles using a Kingcycle trade mark test rig. Power output was measured each second using SRM trade mark Power Cranks. The data were analysed by measuring the reliability of each 30 s of the 3-min test together with the peak power and the peak cadence achieved in the performance element of the test. There was no systematic bias in the data from trial 1 to trial 2 for any of the 6, 30 s blocks of the test, the peak power (mean, 95 % CI, 413.8 w, 357.8 - 469.7 w and 403.8 w, 339.9 - 467.6 w, trial 1 and trial 2, respectively) or peak cadence (95.0 rev x min(-1), 89.5 - 100.5 rev x min(-1) and 95.1 rev x min(-1), 90.0 - 100.1 rev x min(-1), trial 1 and trial 2, respectively). Mean (+/- s) total distance over the 3-min was 2.23 +/- 0.23 km and 2.26 +/- 0.26 km for trial 1 and trial 2 respectively (p > 0.05). The coefficients of variation ranged from 0.9 - 5.4 % and the intraclass correlation coefficients ranged from 0.96 - 0.99. It is concluded that in moderately trained subjects, the 3-min combination test provides reliable data and could therefore be used for short-term, high-intensity cycling intervention studies.
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Affiliation(s)
- M Doherty
- Department of Sport, Exercise and Biomedical Sciences, University of Luton, Luton, UK.
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Abstract
The present study reports the development of a culture system for the analysis of 35S-sulphate release from odontoblasts in vitro. Pulpless longitudinally split rat incisors were cultured in supplemented minimum essential medium (alphaMEM) with 20 microCi 35S-sulphate per ml, 20 microCi 3H-mannitol per ml for 1h. Teeth were then transferred to fresh unlabelled media and aliquots of media were removed and the level of 35S-sulphate 3H-mannitol determined. Results indicated a two phase release of 35S-sulphate into the media, and comparison with pulp tissue indicated a specific release pattern. Transport of sulphate is essential for correct synthesis and glycosylation of macromolecules such as proteoglycans (PG). Previous studies have shown that post-translational modifications of these proteins can be influenced by excess fluoride, resulting in decreased sulphation and elongation of glycosaminoglycan (GAG) chains. Therefore the influence of fluoride on sulphate transport, using the optimised culture system was also investigated. Inclusion of 6mM fluoride during pulse labelling caused a significant decrease of 35S-sulphate (P<0.0001) during the initial release phase. Inclusion of 3 and 6mM fluoride only in the post-labelling incubation media resulted in a significant decrease in the release of 35S-sulphate (P<0.0001), during the total time course. The influence of fluoride was not dose dependent. Inclusion of a specific chloride channel blocker SITS, into the culture system indicated that 35S-sulphate transport may in part be via this route. Fluoride would therefore appear to influence the transport of 35S-sulphate across the odontoblast membrane, potentially via a chloride channel.
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Affiliation(s)
- A M Milan
- Department of Clinical Dental Sciences, The University of Liverpool, Edwards Building, Daulby Street, Liverpool L69 3GN, UK.
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Smith PM, Lakatos A, Barnett SC, Jeffery ND, Franklin RJM. Cryopreserved cells isolated from the adult canine olfactory bulb are capable of extensive remyelination following transplantation into the adult rat CNS. Exp Neurol 2002; 176:402-6. [PMID: 12359182 DOI: 10.1006/exnr.2002.7936] [Citation(s) in RCA: 78] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Abstract
Naturally occurring spinal cord injury in dogs provides a potentially powerful intermediate model for testing the efficacy of therapeutic strategies developed in experimental rodent models before phase 1 trials in human patients. A particularly promising strategy involves transplantation of olfactory ensheathing cells (OECs) that both promote axon regeneration and generate new myelin sheaths. As a first step in developing OEC transplantation in the canine intermediate model we describe the isolation, purification, and characterization of OECs from adult dog olfactory bulb. We also show that the canine OEC behaves in a manner similar to its rodent counterpart following transplantation into demyelinating lesions in rat spinal cord and that these properties are retained following cryopreservation.
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Affiliation(s)
- P M Smith
- Department of Clinical Veterinary Medicine, University of Cambridge, Madingley Road, United Kingdom
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Abstract
The subfornical organ (SFO) has been repeatedly identified as a CNS site that plays a critical role in sensing multiple physiological variables of the "milieu interieur" and, through efferent projections to other CNS sites, initiating physiological responses to change. Many recent in vitro patch-clamp studies have examined the cellular mechanisms underlying the sensory abilities of these specialized CNS neurons. The primary limitation of these studies, however, has been the inability to identify homogeneous groups of SFO neurons for such investigation. We report here the development of techniques to permit patch clamp recording from dissociated SFO neurons identified according to their in vivo projection site. SFO neurons were labeled by injection of fluorescently labeled, retrogradely transported microspheres into the hypothalamic paraventricular nucleus (PVN) 3 days prior to cell dissociation. Patch-clamp recordings from these SFO-PVN neurons revealed both sodium currents, potassium currents, action potentials, input resistance and membrane potential which were all similar to SFO cells prepared from animals with no prior tracer injection. Labeled SFO-->PVN cells were also found to be osmosensitive and responsive to angiotensin II, suggesting specific functional roles for this anatomically defined group of SFO neurons. Intriguingly, our post hoc analysis also demonstrated that all labeled neurons demonstrated a unique electrophysiological profile dominated by a large transient potassium conductance such that the transient/sustained potassium current ratio, or degree of inactivation was, on average, greater than 4.0. Utilization of these tracing techniques to permit the in vitro recording from cells with known in vivo connections will permit study of intrinsic mechanisms that underlie physiological responses of anatomically defined populations of neurons.
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Affiliation(s)
- J W Anderson
- Department of Physiology, Queen's University, Kingston, ON, Canada K7L 3N6
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Ottenbacher KJ, Gonzales VA, Smith PM, Illig SB, Fiedler RC, Granger CV. Satisfaction with medical rehabilitation in patients with cerebrovascular impairment. Am J Phys Med Rehabil 2001; 80:876-84. [PMID: 11821665 DOI: 10.1097/00002060-200112000-00002] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
OBJECTIVE Overall satisfaction has important social and economic implications for patients who have received inpatient medical rehabilitation. We conducted this study to examine the overall satisfaction level at 3- to 6-mo follow-up for inpatients with cerebrovascular impairments discharged from medical rehabilitation. DESIGN The study was retrospective using information from a national database representative of medical rehabilitation patients across the United States. Information submitted in 1997 and 1998 to the Uniform Data System for Medical Rehabilitation by 177 hospital and rehabilitation facilities from 40 states was examined. The final sample included 8,900 patient records. The main outcome measure was the level of satisfaction with medical rehabilitation at 80-180 days postdischarge follow-up. RESULTS A logistic regression model including ten independent variables was used to predict satisfied vs. dissatisfied at follow-up. Three statistically significant variables were included in the final model and correctly classified 95.1% of the patients. Higher FIM instrument discharge scores were associated with increased satisfaction. Further analysis of the FIM instrument subscales indicated that higher ratings in transfers, social cognition, and locomotion were significantly associated with increased satisfaction. CONCLUSION We identified several functional variables associated with increased satisfaction after medical rehabilitation in persons with stroke. The ability to objectively assess patient satisfaction is important as consumer-based outcome measures are integrated in accreditation and healthcare evaluation.
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Affiliation(s)
- K J Ottenbacher
- University of Texas Medical Branch, Galveston, Texas 77555-1028, USA
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Smith PM, Sim FJ, Barnett SC, Franklin RJ. SCIP/Oct-6, Krox-20, and desert hedgehog mRNA expression during CNS remyelination by transplanted olfactory ensheathing cells. Glia 2001; 36:342-53. [PMID: 11746771 DOI: 10.1002/glia.1121] [Citation(s) in RCA: 42] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Olfactory ensheathing cells (OECs), although having a separate developmental origin to Schwann cells, are able to generate myelin sheaths following transplantation into areas of CNS demyelination that are remarkably similar to those made by Schwann cells. The transcriptional control of Schwann cell myelination has been well documented, in particular the role of SCIP/Oct-6 and Krox-20. It is not known, however, whether these transcription factors are also expressed when OECs assume a myelinating phenotype. In this study, we addressed this question by using a transplantation approach to generate myelinating OECs and then examined the expression of SCIP/Oct-6 and Krox-20 mRNA by in situ hybridization using oligonucleotide probes. We also examined the expression of desert hedgehog (Dhh), a Schwann cell-derived signaling molecule that is responsible for regulating the development of the connective tissue elements in peripheral nerve, which bear similarities to the morphologies adopted by nonmyelinating transplanted cells. Our results indicate that both Krox-20 and Dhh mRNA are strongly expressed by transplanted OECs, with SCIP mRNA present at much lower levels. The expression of Krox-20 relative to the expression of P0 mRNA by the transplanted OECs is consistent with its playing a similar role in OEC myelination to that in Schwann cell myelination, while the expression of Dhh suggests a possible mechanism for the diverse morphologies that cells adopt following OEC transplantation into the damaged CNS. Taken together, our results provide further evidence for the close similarity of OECs and Schwann cells and suggest that, despite their separate origins, the manner in which they generate a peripheral-type myelin sheath involves similar regulatory mechanisms.
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Affiliation(s)
- P M Smith
- Department of Clinical Veterinary Medicine, University of Cambridge, Cambridge, UK
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