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81.
Virtual auditory space (VAS) stimuli based on outer ear transfer functions became increasingly important in spatial hearing research. However, few studies have investigated the match between responses of auditory neurons to VAS and free-field (FF) stimulation. This study validates acoustic spatial receptive fields (SRFs) of 183 individual midbrain units using both VAS and FF stimuli. The first-spike latency, which varied systematically across SRFs, was 14.9 +/- 8.3 (SD) ms in FF, and 15.1 +/- 8.3 ms in VAS. Spike-count-based SRFs measured 0-20 dB above the neural threshold covered on average 44.5 +/- 18.0% of the recorded sphere in FF and 45.5 +/- 18.7% in VAS. The average deviation of the centroid position of SRFs using FF and VAS stimuli was 7.4 degrees azimuth and 3.3 degrees elevation. The average spike rate remained unchanged. The SRF overlap recorded using FF and VAS stimuli (mean: 71.3 +/- 12.6%) or repeated FF stimuli (70.2 +/- 14.2%) was high and strongly correlated (r = 0.96; P < 0.05). The SRF match observed with FF and VAS stimuli was not significantly altered over a range of stimulus levels (paired t-test P = 0.51; n = 6). Randomized VAS barely affected SRF sizes, centroids, or maximum spike count but decreased the average minimum response to 59% compared with sequential stimulation (paired t-test; P = 0.05; n = 26). SRF recordings in VAS excluding the acoustic distortions of the recording equipment differed from those in VAS incorporating the equipment (paired t-test P = 0.01; n = 5). In conclusion, neurophysiological recordings demonstrate that individualized VAS stimuli provided a good simulation of a FF environment. 相似文献
82.
Clinical and cost-effectiveness of a new nurse-led continence service: a randomised controlled trial 总被引:3,自引:0,他引:3
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Kate S Williams R Phil Assassa Nicola J Cooper David A Turner Christine Shaw Keith R Abrams Christopher Mayne Carol Jagger Ruth Matthews Michael Clarke Catherine W McGrother The Leicestershire MRC Incontinence Study Team 《The British journal of general practice》2005,55(518):696-703
BACKGROUND: Continence services in the UK have developed at different rates within differing care models, resulting in scattered and inconsistent services. Consequently, questions remain about the most cost-effective method of delivering these services. AIM: To evaluate the impact of a new service led by a continence nurse practitioner compared with existing primary/secondary care provision for people with urinary incontinence and storage symptoms. DESIGN OF STUDY: Randomised controlled trial with a 3- and 6-month follow-up in men and women (n = 3746) aged 40 years and over living in private households (intervention [n = 2958]; control [n = 788]). SETTING: Leicestershire and Rutland, UK. METHOD: The continence nurse practitioner intervention comprised a continence service provided by specially trained nurses delivering evidence-based interventions using predetermined care pathways. They delivered an 8-week primary intervention package that included advice on diet and fluids; bladder training; pelvic floor awareness and lifestyle advice. The standard care arm comprised access to existing primary care including GP and continence advisory services in the area. Outcome measures were recorded at 3 and 6 months post-randomisation. RESULTS: The percentage of individuals who improved (with at least one symptom alleviated) at 3 months was 59% in the intervention group compared with 48% in the standard care group (difference of 11%, 95% CI = 7 to 16; P<0.001) The percentage of people reporting no symptoms or 'cured' was 25% in the intervention group and 15% in the standard care group (difference of 10%, 95% CI = 6 to 13, P = 0.001). At 6 months the difference was maintained. There was a significant difference in impact scores between the two groups at 3 and 6 months. CONCLUSIONS: The continence nurse practitioner-led intervention reduced the symptoms of incontinence, frequency, urgency and nocturia at 3 and 6 months; impact was reduced; and satisfaction with the new service was high. 相似文献
83.
84.
Genetic diversity and identification of human infection by amplification of the chlamydial 60-kilodalton cysteine-rich outer membrane protein gene. 总被引:1,自引:5,他引:1
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The 60-kDa cysteine-rich outer membrane protein genes of Chlamydia psittaci, Chlamydia pneumoniae, and Chlamydia trachomatis have very different 5' ends, but two areas flanking this variable region show absolute sequence conservation. This observation permitted differentiation of the three species of Chlamydia by the polymerase chain reaction (PCR), forming the basis of a diagnostic test for chlamydial infections. The PCR product containing the variable region of the respective 60-kDa CrP genes was also subjected to restriction endonuclease digestion, enabling differentiation of individual type strains of C. psittaci. Differentiation was possible between lymphogranuloma venereum and trachoma isolates of C. trachomatis. The PCR-based diagnostic test was successful with all strains of chlamydiae studied. The PCR primers showed high specificity and did not produce any product with common bacterial pathogens that may share the same sites of infection. 相似文献
85.
A case of Wilms' tumor in an adult is reported, showing, by restriction fragment length polymorphism analysis of somatic and tumor DNA, the loss of alleles from the short arm of chromosome 11. Loss of alleles in this region has previously been reported in childhood Wilms' tumor. The findings of this study indicate that adult Wilms' tumor and childhood Wilms' tumor may share a common pathogenic pathway. These results may also be useful in differentiating between Wilms' tumor and renal cell carcinoma or sarcoma in adults when the histologic findings are unclear. 相似文献
86.
PCR amplification introduces errors into mononucleotide and dinucleotide repeat sequences. 总被引:3,自引:0,他引:3
The polymerase chain reaction (PCR) is used universally for accurate exponential amplification of DNA. We describe a high error rate at mononucleotide and dinucleotide repeat sequence motifs. Subcloning of PCR products allowed sequence analysis of individual DNA molecules from the product pool and revealed that: (1) monothymidine repeats longer than 11 bp are amplified with decreasing accuracy, (2) repeats generally contract during PCR because of the loss of repeat units, (3) Taq and proofreading polymerase Pfu generate similar errors at mononucleotide and dinucleotide repeats, and (4) unlike the parent PCR product pool, individual clones containing a single repeat length produce no "shadow bands". These data demonstrate that routine PCR amplification alters mononucleotide and dinucleotide repeat lengths. Such sequences are common components of genetic markers, disease genes, and intronic splicing motifs, and the amplification errors described here can be mistaken for polymorphisms or mutations. 相似文献
87.
Protection against pneumococcal infection in mice conferred by phosphocholine-binding antibodies: specificity of the phosphocholine binding and relation to several types. 总被引:3,自引:9,他引:3
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![点击此处可从《Infection and immunity》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Some anti-phosphocholine antibodies protect mice against challenge with certain, but not all, pneumococcal types. We found that both their isotype and reactivity with the cell wall C-polysaccharide of encapsulated pneumococci, as measured by immunodiffusion, were important in predicting the protective activity of anti-phosphocholine antibodies. We propose that the specificity of the protective antibodies includes the backbone of the phosphocholine-containing structure. 相似文献
88.
Clarke JR Kaye S Babiker AG Hooker MH Tedder R Weber JN 《Journal of virological methods》2000,88(2):117-124
89.
G. E. Alakpa S. C. Clarke A. F. Fagbenro-Beyioku 《Clinical microbiology and infection》2003,9(7):731-733
Although reports of Cyclospora infection continue to increase globally, few cases have been reported from the African continent. We present 11 cases of cyclosporiasis detected from stool samples submitted to seven major hospital laboratories in Lagos, Nigeria between March 1999 and April 2000. 相似文献
90.
A549 lung epithelial cells grown as three-dimensional aggregates: alternative tissue culture model for Pseudomonas aeruginosa pathogenesis 总被引:5,自引:0,他引:5
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Carterson AJ Höner zu Bentrup K Ott CM Clarke MS Pierson DL Vanderburg CR Buchanan KL Nickerson CA Schurr MJ 《Infection and immunity》2005,73(2):1129-1140
A three-dimensional (3-D) lung aggregate model was developed from A549 human lung epithelial cells by using a rotating-wall vessel bioreactor to study the interactions between Pseudomonas aeruginosa and lung epithelial cells. The suitability of the 3-D aggregates as an infection model was examined by immunohistochemistry, adherence and invasion assays, scanning electron microscopy, and cytokine and mucoglycoprotein production. Immunohistochemical characterization of the 3-D A549 aggregates showed increased expression of epithelial cell-specific markers and decreased expression of cancer-specific markers compared to their monolayer counterparts. Immunohistochemistry of junctional markers on A549 3-D cells revealed that these cells formed tight junctions and polarity, in contrast to the cells grown as monolayers. Additionally, the 3-D aggregates stained positively for the production of mucoglycoprotein while the monolayers showed no indication of staining. Moreover, mucin-specific antibodies to MUC1 and MUC5A bound with greater affinity to 3-D aggregates than to the monolayers. P. aeruginosa attached to and penetrated A549 monolayers significantly more than the same cells grown as 3-D aggregates. Scanning electron microscopy of A549 cells grown as monolayers and 3-D aggregates infected with P. aeruginosa showed that monolayers detached from the surface of the culture plate postinfection, in contrast to the 3-D aggregates, which remained attached to the microcarrier beads. In response to infection, proinflammatory cytokine levels were elevated for the 3-D A549 aggregates compared to monolayer controls. These findings suggest that A549 lung cells grown as 3-D aggregates may represent a more physiologically relevant model to examine the interactions between P. aeruginosa and the lung epithelium during infection. 相似文献