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The Global ETD Search service is a free service for researchers
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Showing 351 to 360 of 372 (0.012 seconds)| 351 |
Effect of Moderate Exercise on Proliferative Responses of Peripheral Blood Mononuclear CellsSmith, J, Chi, D, Salazar, S, Krish, G., Berk, S., Reynolds, S., Cambron, G. 01 June 1993 (has links)
We studied the effects of 30 minutes of exercise on T lymphocyte counts and proliferative responses of peripheral blood mononuclear cells (PBMC) in 25 runners. Exercise resulted in a T lymphocytosis in the immediate post-exercise period in all subjects (p < 0.001), and reduced CD4+/CD8+ ratios in 22/25 subjects (p = 0.001). The change was due primarily to a 2.2-fold increase in CD8+ cells (p < 0.001). Exercise also reduced PBMC mitogenic responses to phytohemagglutinin (PHA) in 13/14 subjects (p = 0.049), and to pokeweed mitogen (PWM) in 11/14 subjects (p = 0.022), but not to concanavalin A. Postrun sera from 5 of 6 subjects inhibited PHA but not PWM responses of resting autologous PBMC with normal CD4+/CD8+ ratios (p < or = 0.05): indomethacin and monocyte depletion blocked the serum inhibition (p = 0.003, p = 0.0006, respectively). We conclude that post-exercise suppression of mitogenic responses to PHA is due to the release of a serum factor(s) capable of inducing prostaglandin synthesis by circulating monocytes, whereas exercise-induced suppression of PWM responses depends primarily on the reversal of CD4+/CD8+ ratios.
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Recognition Performance on Words Interrupted (10 Ips, 50% Duty Cycle) With Two Interruption Patterns Referenced to Word Onset: Young Listeners With Normal Hearing for Pure Tones and Older Listeners With Sensorineural Hearing LossWilson, Richard H., Irish, Staci E. 01 January 2015 (has links)
OBJECTIVE: To determine in an interrupted word paradigm (Maryland CNCs; 10 ips, 50% duty cycle) if different locations of the interruption pattern produce different recognition performances. DESIGN: Repeated measures using two interruption patterns that were complementary halves referenced to word onset; one started with word onset (0-ms), the other started 50 ms later. The hypothesis was that recognition performance would be better on the 0-ms condition than on the 50-ms condition, but there would be some words with the reverse relation. STUDY SAMPLE: Twenty-four young adults with normal hearing for pure tones and 32 older adults (mean = 67 years) with sensorineural hearing loss participated. RESULTS: With the young listeners mean recognition performance on the 0-ms condition (63.1%) was significantly better than the mean performance on the 50-ms condition (47.8%). About twice as many words had better performance on the 0-ms condition. With the older listeners, who were given only stimuli on which performances were > 58% by the young normals, performances on the two conditions were the same. CONCLUSIONS: The hypothesis was supported with the young listeners. The equal performance by the older listeners on the two conditions was attributed to the manner in which the words were selected.
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Cerebral venous outflow resistance and interpretation of cervical plethysmography data with respect to the diagnosis of chronic cerebrospinal venous insufficiencyBeggs, Clive B., Shepherd, Simon J., Zamboni, P. January 2014 (has links)
No / PURPOSE: To investigate cerebrospinal fluid (CSF) dynamics in the aqueduct of Sylvius (AoS) in chronic cerebrospinal venous insufficiency (CCSVI)-positive and -negative healthy individuals using cine phase contrast imaging. MATERIALS AND METHODS: Fifty-one healthy individuals (32 CCSVI-negative and 19 age-matched CCSVI-positive subjects) were examined using Doppler sonography (DS). Diagnosis of CCSVI was established if subjects fulfilled >/=2 venous hemodynamic criteria on DS. CSF flow and velocity measures were quantified using a semiautomated method and compared with clinical and routine 3T MRI outcomes. RESULTS: CCSVI was associated with increased CSF pulsatility in the AoS. Net positive CSF flow was 32% greater in the CCSVI-positive group compared with the CCSVI-negative group (P = 0.008). This was accompanied by a 28% increase in the mean aqueductal characteristic signal (ie, the AoS cross-sectional area over the cardiac cycle) in the CCSVI-positive group compared with the CCSVI-negative group (P = 0.021). CONCLUSION: CSF dynamics are altered in CCSVI-positive healthy individuals, as demonstrated by increased pulsatility. This is accompanied by enlargement of the AoS, suggesting that structural changes may be occurring in the brain parenchyma of CCSVI-positive healthy individuals.
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Jugular venous reflux and white matter abnormalities in Alzheimer's disease: a pilot studyChung, C.P., Beggs, Clive B., Wang, P.N., Bergsland, N., Shepherd, Simon J., Cheng, C.Y., Ramasamy, D.P., Dwyer, Michael G., Hu, H.H., Zivadinov, R. January 2014 (has links)
yes / To determine whether jugular venous reflux (JVR) is associated with cerebral white matter changes (WMCs) in individuals with Alzheimer's disease (AD), we studied 12 AD patients 24 mild cognitive impairment (MCI) patients, and 17 elderly age- and gender-matched controls. Duplex ultrasonography and 1.5T MRI scanning was applied to quantify cerebral WMCs [T2 white matter (WM) lesion and dirty-appearing-white-matter (DAWM)]. Subjects with severe JVR had more frequently hypertension (p = 0.044), more severe WMC, including increased total (p = 0.047) and periventricular DAWM volumes (p = 0.008), and a trend for increased cerebrospinal fluid volumes (p = 0.067) compared with the other groups. A significantly decreased (65.8%) periventricular DAWM volume (p = 0.01) in the JVR-positive AD individuals compared with their JVR-negative counterparts was detected. There was a trend for increased periventricular and subcortical T2 WMC lesion volumes in the JVR-positive AD individuals compared with their JVR-negative counterparts (p = 0.073). This phenomenon was not observed in either the control or MCI groups. In multiple regression analysis, the increased periventricular WMC lesion volume and decreased DAWM volume resulted in 85.7% sensitivity and 80% specificity for distinguishing between JVR-positive and JVR-negative AD patients. These JVR-WMC association patterns were not seen in the control and MCI groups. Therefore, this pilot study suggests that there may be an association between JVR and WMCs in AD patients, implying that cerebral venous outflow impairment might play a role in the dynamics of WMCs formation in AD patients, particularly in the periventricular regions. Further longitudinal studies are needed to confirm and validate our findings.
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Factors influencing European consumer uptake of personalised nutrition. Results of a qualitative analysisStewart-Knox, Barbara, Kuznesof, S., Robinson, J., Rankin, A., Orr, K., Duffy, M., Poinhos, R., de Almeida, M.D.V., Macready, A.L., Gallagher, C., Berezowska, A., Fischer, A.R.H., Navas-Carretero, S., Riemer, M., Traczyk, I., Gjelstad, I.M.F., Mavrogianni, C., Frewer, L.J. January 2013 (has links)
The aim of this research was to explore consumer perceptions of personalised nutrition and to compare these across three different levels of "medicalization": lifestyle assessment (no blood sampling); phenotypic assessment (blood sampling); genomic assessment (blood and buccal sampling). The protocol was developed from two pilot focus groups conducted in the UK. Two focus groups (one comprising only "older" individuals between 30 and 60 years old, the other of adults 18-65 yrs of age) were run in the UK, Spain, the Netherlands, Poland, Portugal, Ireland, Greece and Germany (N=16). The analysis (guided using grounded theory) suggested that personalised nutrition was perceived in terms of benefit to health and fitness and that convenience was an important driver of uptake. Negative attitudes were associated with internet delivery but not with personalised nutrition per se. Barriers to uptake were linked to broader technological issues associated with data protection, trust in regulator and service providers. Services that required a fee were expected to be of better quality and more secure. An efficacious, transparent and trustworthy regulatory framework for personalised nutrition is required to alleviate consumer concern. In addition, developing trust in service providers is important if such services to be successful.
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Patient and other factors influencing the prescribing of cardiovascular prevention therapy in the general practice setting with and without nurse assessmentMohammed, Mohammed A., El Sayed, C., Marshall, T. January 2012 (has links)
Although guidelines indicate when patients are eligible for antihypertensives and statins, little is known about whether general practitioners (GPs) follow this guidance. To determine the factors influencing GPs decisions to prescribe cardiovascular prevention drugs. DESIGN OF STUDY: Secondary analysis of data collected on patients whose cardiovascular risk factors were measured as part of a controlled study comparing nurse-led risk assessment (four practices) with GP-led risk assessment (two practices). SETTING: Six general practices in the West Midlands, England. PATIENTS: Five hundred patients: 297 assessed by the project nurse, 203 assessed by their GP. MEASUREMENTS: Cardiovascular risk factor data and whether statins or antihypertensives were prescribed. Multivariable logistic regression models investigated the relationship between prescription of preventive treatments and cardiovascular risk factors. RESULTS: Among patients assessed by their GP, statin prescribing was significantly associated only with a total cholesterol concentration >/= 7 mmol/L and antihypertensive prescribing only with blood pressure >/= 160/100 mm Hg. Patients prescribed an antihypertensive by their GP were five times more likely to be prescribed a statin. Among patients assessed by the project nurse, statin prescribing was significantly associated with age, sex, and all major cardiovascular risk factors. Antihypertensive prescribing was associated with blood pressures >/= 140/90 mm Hg and with 10-year cardiovascular risk. LIMITATIONS: Generalizability is limited, as this is a small analysis in the context of a specific cardiovascular prevention program. CONCLUSIONS: GP prescribing of preventive treatments appears to be largely determined by elevation of a single risk factor. When patients were assessed by the project nurse, prescribing was much more consistent with established guidelines.
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The Rivermead Mobility Index allows valid comparisons between subgroups of patients undergoing rehabilitation after stroke who differ with respect to age, sex, or side of lesionRoorda, L.D., Green, J.R., Houwink, A., Bagley, Pamela J., Smith, J., Molenaar, I.W., Geurts, A.C. January 2012 (has links)
To investigate differential item functioning or item bias of the Rivermead Mobility Index (RMI) and its impact on the drawing of valid comparisons with the RMI between subgroups of patients after stroke who differ with respect to age, sex, or side of lesion. DESIGN: Cross-sectional study. SETTING: A rehabilitation center in the Netherlands and 2 stroke rehabilitation units and the wider community in the United Kingdom. PARTICIPANTS: The RMI was completed for patients undergoing rehabilitation after stroke (N=620; mean age +/- SD, 69.2+/-12.5y; 297 [48%] men; 269 [43%] right hemisphere lesion, and 304 [49%] left hemisphere lesion). INTERVENTIONS: Not applicable. MAIN OUTCOME MEASURES: Mokken scale analysis was used to investigate differential item functioning of the RMI between subgroups of patients who differed with respect to age (young vs older), sex (men vs women), and side of stroke lesion (right vs left hemisphere). RESULTS: No differential item functioning was found for any of the comparison subgroups. CONCLUSIONS: The RMI allows valid comparisons to be made between subgroups of patients undergoing rehabilitation after stroke who differ with respect to age, sex, or side of lesion.
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Item hierarchy-based analysis of the Rivermead Mobility Index resulted in improved interpretation and enabled faster scoring in patients undergoing rehabilitation after strokeRoorda, L.D., Green, J.R., Houwink, A., Bagley, Pamela J., Smith, J., Molenaar, I.W., Geurts, A.C. January 2012 (has links)
To enable improved interpretation of the total score and faster scoring of the Rivermead Mobility Index (RMI) by studying item ordering or hierarchy and formulating start-and-stop rules in patients after stroke. DESIGN: Cohort study. SETTING: Rehabilitation center in the Netherlands; stroke rehabilitation units and the community in the United Kingdom. PARTICIPANTS: Item hierarchy of the RMI was studied in an initial group of patients (n=620; mean age +/- SD, 69.2+/-12.5y; 297 [48%] men; 304 [49%] left hemisphere lesion, and 269 [43%] right hemisphere lesion), and the adequacy of the item hierarchy-based start-and-stop rules was checked in a second group of patients (n=237; mean age +/- SD, 60.0+/-11.3y; 139 [59%] men; 103 [44%] left hemisphere lesion, and 93 [39%] right hemisphere lesion) undergoing rehabilitation after stroke. INTERVENTIONS: Not applicable. MAIN OUTCOME MEASURES: Mokken scale analysis was used to investigate the fit of the double monotonicity model, indicating hierarchical item ordering. The percentages of patients with a difference between the RMI total score and the scores based on the start-and-stop rules were calculated to check the adequacy of these rules. RESULTS: The RMI had good fit of the double monotonicity model (coefficient H(T)=.87). The interpretation of the total score improved. Item hierarchy-based start-and-stop rules were formulated. The percentages of patients with a difference between the RMI total score and the score based on the recommended start-and-stop rules were 3% and 5%, respectively. Ten of the original 15 items had to be scored after applying the start-and-stop rules. CONCLUSIONS: Item hierarchy was established, enabling improved interpretation and faster scoring of the RMI.
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Cancelled surgeries and payment by results in the English National Health ServiceMcIntosh, Bryan, Cookson, G., Jones, S. January 2012 (has links)
OBJECTIVES: To model the frequency of 'last minute' cancellations of planned elective procedures in the English NHS with respect to the patient and provider factors that led to these cancellations. METHODS: A dataset of 5,288,604 elective patients spell in the English NHS from January 1st, 2007 to December 31st, 2007 was extracted from the Hospital Episode Statistics. A binary dependent variable indicating whether or not a patient had a Health Resource Group coded as S22--'Planned elective procedure not carried out'--was modeled using a probit regression estimated via maximum likelihood including patient, case and hospital level covariates. RESULTS: Longer waiting times and being admitted on a Monday were associated with a greater rate of cancelled procedures. Male patients, patients from lower socio-economic groups and older patients had higher rates of cancelled procedures. There was significant variation in cancellation rates between hospitals; Foundation Trusts and private facilities had the lowest cancellation rates. CONCLUSIONS: Further research is needed on why Foundation Trusts exhibit lower cancellation rates. Hospitals with relatively high cancellation rates should be encouraged to tackle this problem. Further evidence is needed on whether hospitals are more likely to cancel operations where the procedure tariff is lower than the S22 tariff as this creates a perverse incentive to cancel. Understanding the underlying causes of why male, older and patients from lower socio-economic groups are more likely to have their operations cancelled is important to inform the appropriate policy response. This research suggests that interventions designed to reduce cancellation rates should be targeted to high-cancellation groups.
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Ethnicity and differences between clinic and ambulatory blood pressure measurementsMartin, U., Haque, M.S., Wood, S., Greenfield, S.M., Gill, P.S., Mant, J., Mohammed, Mohammed A., Heer, G., Johal, A., Kaur, R., Schwartz, C.L., McManus, R.J. January 2015 (has links)
Yes / This study investigated the relationship of ethnicity to the differences between blood pressure (BP) measured in a clinic setting and by ambulatory blood pressure monitoring (ABPM) in individuals with a previous diagnosis of hypertension (HT) and without a previous diagnosis of hypertension (NHT). A cross-sectional comparison of BP measurement was performed in 770 participants (white British (WB, 39%), South Asian (SA, 31%), and African Caribbean (AC, 30%)) in 28 primary care clinics in West Midlands, United Kingdom. Mean differences between daytime ABPM, standardized clinic (mean of 3 occasions), casual clinic (first reading on first occasion), and last routine BP taken at the general practitioner practice were compared in HT and NHT individuals. Daytime systolic and diastolic ABPM readings were similar to standardized clinic BP (systolic: 128 (SE 0.9) vs. 125 (SE 0.9) mm Hg (NHT) and 132 (SE 0.7) vs. 131 (SE 0.7) mm Hg (HT)) and were not associated with ethnicity to a clinically important extent. When BP was taken less carefully, differences emerged: casual clinic readings were higher than ABPM, particularly in the HT group where the systolic differences approached clinical relevance (131 (SE 1.2) vs. 129 (SE 1.0) mm Hg (NHT) and 139 (SE 0.9) vs. 133 (SE 0.7) mm Hg (HT)) and were larger in SA and AC hypertensive individuals (136 (SE 1.5) vs. 133 (SE 1.2) mm Hg (WB), 141 (SE 1.7) vs. 133 (SE 1.4) mm Hg (SA), and 142 (SE 1.6) vs. 134 (SE 1.3) mm Hg (AC); mean differences: 3 (0-7), P = 0.03 and 4 (1-7), P = 0.01, respectively). Differences were also observed for the last practice reading in SA and ACs. BP differences between ethnic groups where BP is carefully measured on multiple occasions are small and unlikely to alter clinical management. When BP is measured casually on a single occasion or in routine care, differences appear that could approach clinical relevance.
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