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41.
The hemagglutinins of influenza viruses isolated from humans typically prefer binding to sialic acid in an alpha2,6 linkage. Presumably, the virus uses the presence of these receptors on the respiratory tract to gain entrance into the host cell. The ST6Gal I sialyltransferase knock-out mouse lacks the main enzyme necessary for the attachment of alpha2,6 sialic acid to N-linked glycoproteins on the cell surface. Yet even in the absence of detectable alpha2,6 sialic acid in the mouse respiratory tract, human influenza viruses can still infect these mice and grow to similar titers in the lung and trachea as compared to wild-type animals. This work demonstrates that the presence of a major alpha2,6 sialic acid on N-linked glycoproteins is not essential for human influenza virus infection in mice. 相似文献
42.
Akihiro Takamiya Annemiek Dols Louise Emsell Christopher Abbott Antoine Yrondi Carles Soriano Mas Martin Balslev Jorgensen Pia Nordanskog Didi Rhebergen Eric van Exel Mardien L Oudega Filip Bouckaert Mathieu Vandenbulcke Pascal Sienaert Patrice Pran Marta Cano Narcis Cardoner Anders Jorgensen Olaf B Paulson Paul Hamilton Robin Kampe Willem Bruin Hauke Bartsch Olga Therese Ousdal Ute Kessler Guido van Wingen Leif Oltedal Taishiro Kishimoto 《Schizophrenia bulletin》2022,48(2):514
Psychotic major depression (PMD) is hypothesized to be a distinct clinical entity from nonpsychotic major depression (NPMD). However, neurobiological evidence supporting this notion is scarce. The aim of this study is to identify gray matter volume (GMV) differences between PMD and NPMD and their longitudinal change following electroconvulsive therapy (ECT). Structural magnetic resonance imaging (MRI) data from 8 independent sites in the Global ECT-MRI Research Collaboration (GEMRIC) database (n = 108; 56 PMD and 52 NPMD; mean age 71.7 in PMD and 70.2 in NPMD) were analyzed. All participants underwent MRI before and after ECT. First, cross-sectional whole-brain voxel-wise GMV comparisons between PMD and NPMD were conducted at both time points. Second, in a flexible factorial model, a main effect of time and a group-by-time interaction were examined to identify longitudinal effects of ECT on GMV and longitudinal differential effects of ECT between PMD and NPMD, respectively. Compared with NPMD, PMD showed lower GMV in the prefrontal, temporal and parietal cortex before ECT; PMD showed lower GMV in the medial prefrontal cortex (MPFC) after ECT. Although there was a significant main effect of time on GMV in several brain regions in both PMD and NPMD, there was no significant group-by-time interaction. Lower GMV in the MPFC was consistently identified in PMD, suggesting this may be a trait-like neural substrate of PMD. Longitudinal effect of ECT on GMV may not explain superior ECT response in PMD, and further investigation is needed. 相似文献
43.
The purpose of the present study was to examine the outcome profiles of a large number of patients with locally advanced
adenocarcinoma of the prostate following radical perineal prostatectomy (RPP) for clinically organ-confined disease. Of 1662
men who underwent RPP performed by a single surgeon between January 1972 and January 1999, 692 patients (41.6%) aged a median
of 66.1 years were found to have extracapsular disease on pathological evaluation. The extent of disease was categorized as
either specimen-confined (n=355) or margin-positive (n=337). The histological grade of the cancer was characterized using the Gleason score. Time to biochemical failure, defined
as a prostate-specific antigen (PSA) level of ≥0.5 ng/ml, and cancer-associated survival were the end points of our outcome
analysis using the Kaplan-Meier product-limit method. The median time to cancer-associated death for patients with specimen-
confined and margin-positive disease was 18.5 and 13.1 years, respectively. After 5 years, 37% and 54% of the patients with
specimen-confined and margin-positive disease, respectively, had PSA failure. Prostate cancer patients with a Gleason score
of 5–6, 7, and 8–10 experienced a median time to cancer-associated death of 19.9, 19.2, and 10.5 years, respectively. A subset
of patients undergoing adjunctive radiation therapy (XRT) relapsed biochemically after a median period of approximately 18 months.
RPP provides a substantial disease-control benefit in patients with specimen-confined cancer. The time to biochemical failure
and the time to cancer-associated death are significantly influenced by the biology of the underlying disease, necessitating
long-term follow-up in the outcome analysis of any modality of treatment for prostate cancer. A benefit of early adjunctive
XRT for local failure remains to be determined. 相似文献
44.
The present study investigated the effect of attention on brain activation in a dichotic listening situation. Dichotic listening is a technique to study laterality effects in the auditory sensory modality. Two different stimuli were presented simultaneously, one in each ear. Twelve subjects listened to lists of consonant-vowel syllables, or short musical instrument passages, with the task of detecting a "target" syllable or musical instrument by pressing a button. The target stimulus appeared an equal number of times in the left and right ear. The subjects were instructed to either concentrate on the stimuli presented in both ears, or only on the left or right ear stimulus. Brain activation was measured with 15O-PET, and significant changes in regional normalized counts (rNC) were evaluated using statistical parametric mapping (SPM96) software. Concentrating on either the right or left ear stimulus significantly decreased activity bilaterally in the temporal lobes compared to concentrating on both ear stimuli, at the expense of an increased activation in the right posterior and inferior superior parietal lobe. The CV-syllables activated areas corresponding to the classic language areas of Broca and Wernicke. The musical instrument stimuli mainly activated areas in visual association cortex, cerebellum, and the hippocampus. An interpretation of the findings is that attention has a facilitating effect for auditory processing, causing reduced activation in the primary auditory cortex when attention is explicitly recruited. The observed activations in the parietal lobe during the focused attention conditions could be part of a modality non-specific "attentional network". 相似文献
45.
Heterogeneity of neocortical cerebral blood flow deficits in dementia of the Alzheimer type: a [99mTc]-d,l-HMPAO SPECT study. 下载免费PDF全文
G Waldemar P Bruhn M Kristensen A Johnsen O B Paulson N A Lassen 《Journal of neurology, neurosurgery, and psychiatry》1994,57(3):285-295
Regional cerebral blood flow (rCBF) was measured with high resolution brain dedicated single photon emission computer tomography (SPECT) and [99mTc]-d,l-hexamethyl-propylene-amine-oxime (HMPAO) in 25 patients with probable Alzheimer's disease and in 25 control subjects, selected according to rigorous inclusion and exclusion criteria. The aim was to analyse the topography of rCBF deficits in individual patients. In the group of patients with Alzheimer's disease as a whole, global CBF was reduced, but a factorial analysis of variance did not show disproportionate reduction of rCBF in any brain region. A parametric analysis of the rCBF data in individual patients was carried out with reference to normal values for internal rCBF ratios and to 13 different abnormal rCBF patterns. These theoretical patterns were predefined by showing significant hypoperfusion in at least one, or in any relevant combination of two, three, or four, of four major brain regions (a left and right frontal and a left and right posterior region). All patients with Alzheimer's disease and none of the control subjects had an abnormal rCBF pattern. Eleven of the 13 different patterns were seen in the patients. Frontal changes were seen in 19 (76%) of the patients, more often than previously reported. No single Alzheimer's disease pattern could be derived from our data. The number of regions with hypoperfusion, but not the presence of frontal changes, correlated significantly with the duration of disease. It is concluded that a clinical diagnosis of probable Alzheimer's disease is associated with heterogeneous patterns of rCBF deficits as measured with SPECT and [99mTc]-d,l-HMPAO. This heterogeneity may reflect different stages of the disease or cognitive subtypes and help explain published discrepancies concerning the topography of hypoperfusion in Alzheimer's disease. An analysis of individual rCBF data may add important information in the investigation of diseases with heterogeneous effects on the brain. 相似文献
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48.
Victoria L. Goosey-Tolfrey Thomas A. W. Paulson Keith Tolfrey Roger G. Eston 《European journal of applied physiology》2014,114(6):1251-1258
Purpose
To assess the validity of predicting peak oxygen uptake ( $ {\dot{\text{V}}}{\text{O}}_{{\text{2peak}}}$ ) from differentiated ratings of perceived exertion (RPE) obtained during submaximal wheelchair propulsion.Methods
Three subgroups of elite male wheelchair athletes [nine tetraplegics (TETRA), nine paraplegics (PARA), eight athletes without spinal cord injury (NON-SCI)] performed an incremental speed exercise test followed by graded exercise to exhaustion ( $ {\dot{\text{V}}}{\text{O}}_{{\text{2peak}}}$ test). Oxygen uptake ( $ {\dot{\text{V}}}{\text{O}}_2$ ), heart rate (HR) and differentiated RPE (Central RPEC, Peripheral RPEP and Overall RPEO) were obtained for each stage. The regression lines for the perceptual ranges 9–15 on the Borg 6–20 scale ratings were performed to predict $ {\dot{\text{V}}}{\text{O}}_{{\text{2peak}}}$ .Results
There were no significant within-group mean differences between measured $ {\dot{\text{V}}}{\text{O}}_{{\text{2peak}}}$ (mean 1.50 ± 0.39, 2.74 ± 0.48, 3.75 ± 0.33 L min?1 for TETRA, PARA and NON-SCI, respectively) and predicted $ {\dot{\text{V}}}{\text{O}}_{{\text{2peak}}}$ determined using HR or differentiated RPEs for any group (P > 0.05). However, the coefficients of variation (CV %) between measured and predicted $ {\dot{\text{V}}}{\text{O}}_{{\text{2peak}}}$ using HR showed high variability for all groups (14.3, 15.9 and 9.7 %, respectively). The typical error ranged from 0.14 to 0.68 L min?1 and the CV % between measured and predicted $ {\dot{\text{V}}}{\text{O}}_{{\text{2peak}}}$ using differentiated RPE was ≤11.1 % for TETRA, ≤7.5 % for PARA and ≤20.2 % for NON-SCI.Conclusions
Results suggest that differentiated RPE may be used cautiously for TETRA and PARA athletes when predicting $ {\dot{\text{V}}}{\text{O}}_{{\text{2peak}}}$ across the perceptual range of 9–15. However, predicting $ {\dot{\text{V}}}{\text{O}}_{{\text{2peak}}}$ is not recommended for the NON-SCI athletes due to the large CV %s (16.8, 20.2 and 18.0 %; RPEC, RPEP and RPEO, respectively). 相似文献49.
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