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Advanced age has been associated with a wide range of defects in both the innate and adaptive immune systems including diminished specific antibody responses that increase the risk of invasive pneumococcal disease (IPD) and limit the effectiveness of vaccines. However, the elderly are a heterogeneous group and measures of overall frailty may be a better indicator of disease susceptibility (or vaccine response) than chronological age alone. 相似文献
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A controlled trial of scheduled replacement of central venous and pulmonary-artery catheters. 总被引:12,自引:0,他引:12
D K Cobb K P High R G Sawyer C A Sable R B Adams D A Lindley T L Pruett K J Schwenzer B M Farr 《The New England journal of medicine》1992,327(15):1062-1068
BACKGROUND. The incidence of infection increases with the prolonged use of central vascular catheters, but it is unclear whether changing catheters every three days, as some recommend, will reduce the rate of infection, It is also unclear whether it is safer to change a catheter over a guide wire or insert it at a new site. METHODS. We conducted a controlled trial in adult patients in intensive care units who required central venous or pulmonary-artery catheters for more than three days. Patients were assigned randomly to undergo one of four methods of catheter exchange: replacement every three days either by insertion at a new site (group 1) or by exchange over a guide wire (group 2), or replacement when clinically indicated either by insertion at a new site (group 3) or by exchange over a guide wire (group 4). RESULTS. Of the 160 patients, 5 percent had catheter-related bloodstream infections, 16 percent had catheters that became colonized, and 9 percent had major mechanical complications. The incidence rates (per 1000 days of catheter use) of bloodstream infection were 3 in group 1, 6 in group 2, 2 in group 3, and 3 in group 4; the incidence rates of mechanical complications were 14, 4, 8, and 3, respectively. Patients randomly assigned to guide-wire-assisted exchange were more likely to have bloodstream infection after the first three days of catheterization (6 percent vs. 0, P = 0.06). Insertions at new sites were associated with more mechanical complications (5 percent vs. 1 percent, P = 0.005). CONCLUSIONS. Routine replacement of central vascular catheters every three days does not prevent infection. Exchanging catheters with the use of a guide wire increases the risk of bloodstream infection, but replacement involving insertion of catheters at new sites increases the risk of mechanical complications. 相似文献
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J. M. Wardlaw M. S. Dennis R. I. Lindley R. J. Sellar C. P. Wadaw 《Journal of neurology》1996,243(3):274-279
The aim of the study reported here was to test the validity of a simple clinical classification of acute ischaemic stroke (Oxfordshire Community Stroke Project, OCSP) in predicting the site and size of cerebral infarction on computed tomography (CT). Consecutive patients admitted to hospital with acute ischaemic stroke were prospectively identified and classified into one of four clinical syndromes according to the OCSP classification, blind to the result of CT. The CT brain scans were classified blind to the clinical features into those demonstrating: small, medium or large cortical infarcts; small or large subcortical infarcts in the anterior circulation territory; and posterior cerebral circulation territory infarcts. A total of 108 patients were included. A recent infarct was seen. on the CT scan in 91 patients (84%), and the clinical classification correctly predicted the site and size of the cerebral infarct in 80 of these (88%; 95% confidence interval 77–92%). The positive predictive value was best for large cortical infarcts (0.94) and worst for small subcortical infarcts (0.63). The OCSP clinical classification is a reasonably valid way of predicting the site and size of cerebral infarction on CT and can, therefore, be used very early after stroke onset before the infarct appears on the scan. 相似文献
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R D Goldin M Wilkins S Dourakis J Parkin R Lindley 《Journal of clinical pathology》1993,46(11):1036-1038
AIMS--To assess histologically the amount of iron deposited in liver biopsy specimens from HIV positive patients; and to perform estimations of liver iron on tissue from patients with an increase in parenchymal stainable iron. To correlate the amount of blood transfused and the degree of iron overload. METHODS--Liver biopsy specimens (n = 120) from 109 HIV positive patients, 74 of whom had AIDS, were examined retrospectively and the amount of iron, as visualised with Perls's stain, was graded. Fibrosis was assessed using connective tissue stains. Estimations of liver iron were performed on tissue retrieved from paraffin wax blocks in cases with histological grade 3 or 4 iron overload. The amount of blood transfused before liver biopsy was determined from the notes for each patient. RESULTS--Fifteen of the 120 liver biopsy specimens had significantly increased amounts of iron in their hepatocytes, as assessed histologically, and this was confirmed in seven cases by measurement of liver iron. There was a close correlation between the amount of blood transfused and the degree of iron overload. In the initial biopsy specimens only one case showed portal tract expansion. Three of the five patients who had repeat biopsies, however, showed progressive fibrosis. CONCLUSION--Multiply transfused HIV positive patients may develop clinically important iron overload and are at risk of developing progressive fibrosis. Superimposed liver disease, especially viral hepatitis, in these high risk patients may exacerbate the effects of the iron overload. 相似文献
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Membrane permeability changes during stimulation of isolated salivary glands of Calliphora by 5-hydroxytryptamine. 总被引:3,自引:0,他引:3 下载免费PDF全文
1. The membrane resistance of isolated salivary glands was found to decrease in response to 5-HT. The change in resistance was calcium-dependent. 2. The resistance change of the apical membrane was found to be much greater than the change in resistance of the basal membrane. 3. Potential responses under current-clamped conditions showed that one part of the biphasic response to 5-HT (attributed to an increase in chloride permeability) could be reversed and the other part (attributed to an increase in a potassium pump) could not. 4. These observations have been incorporated into a model which, on evaluation, predicts all of the observed potential changes during the action of 5-HT. It suggests that the potential responses reflect changes in the internal chloride concentration produced by the calcium-dependent increases in chloride permeability. 相似文献
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The comparative effects of adhesive tape and three semirigid ankle orthoses on ankle functional range of motion were studied on 11 college football athletes. Maximum plantar flexion and maximum dorsiflexion were measured under five conditions to determine functional range of motion. Testing conditions included: control (no supportive device), adhesive tape with moleskin, the Airstirrup “Training” orthosis, the Active Ankle “Trainer” orthosis, and the Ankle Ligament Protector. A 200-Hz video camera was used to record subjects' motions in the sagittal plane while they ran a series of 40-yd sprints. Videotape was analyzed with the Peak Performance Technology Motion Measurement System. Data were analyzed with a Repeated Measures MANOVA. Differences were found among treatments for maximum plantar flexion and functional range of motion. Follow-up analyses indicated that the Ankle Ligament Protector was the only supportive device that was significantly more restrictive than the control. The Airstirrup, Active Ankle, and adhesive tape with moleskin do not significantly affect functional range of motion during running. 相似文献
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