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BACKGROUND: A person's risk for acquiring infection and their role in continued transmission has traditionally been assessed on the basis of individual characteristics. Recently, network studies have attempted to relate individual risks to position in the wider network. GOAL: To assess the importance of local and global network structures in assessing the risk of acquiring and transmitting infection. STUDY DESIGN: An individual-based simulation model was used to construct a variety of potential network structures and track the transmission of infection over time. Logistic and Poisson regression were used to identify which measures of network position influence a person's risk for acquiring and transmitting infection. RESULTS: Measures of local centrality were more important to risk of acquisition, whereas global centrality mattered more to transmission. Continuous snowball sampling, rather than a fixed number of waves, better estimates a person's risks. CONCLUSIONS: There is an asymmetry regarding the risk of acquiring and transmitting infection.  相似文献   
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Brain imaging techniques such as MRI and PET have the potential for identifying central nervous system involvement in SLE. They may also help elucidate the mechanisms giving rise to the widely diverging manifestations of CNS involvement in SLE. This report documents an intensive longitudinal study of three women with neuropsychiatric SLE. PET and neuropsychological evaluation were both used to examine the co-occurrence of behavioural/cognitive deficits with alterations in regional brain glucose metabolism. In all three patients, FDG uptake indicated abnormalities which were not identified on CT scan, but corresponded well with localisable cognitive deficits. Changes in each patient's cognitive profile on reassessment paralleled changes on PET. These findings support the suggestion that cognitive deficits in SLE patients reflect primary CNS involvement.  相似文献   
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Summary: Purpose: Convulsive status epilepticus (CSE) is a major medical and neurological emergency that is associated with significant morbidity and mortality. Despite this high morbidity and mortality, most acute care facilities in the United States cannot evaluate patients with EEG monitoring during or immediately after SE. The present study was initiated to determine whether control of CSE by standard treatment protocols was sufficient to terminate electrographic seizures. Methods: One hundred sixty-four prospective patients were evaluated at the Medical College of Virginia/VCU Status Epilepticus Program. Continuous EEG monitoring was performed for a minimum of 24 h after clinical control of CSE. SE and seizure types were defined as described previously. A standardized data form entry system was compiled for each patient and used to evaluate the data collected. Results: After CSE was controlled, continuous EEG monitoring demonstrated that 52% of the patients had no after-SE ictal discharges (ASIDS) and manifested EEG patterns of generalized slowing, attenuation, periodic lateralizing epileptiform discharges (PLEDS), focal slowing, and/or burst suppression. The remaining 48% demonstrated persistent electrographic seizures. More than 14% of the patients manifested nonconvulsive SE (NCSE) predominantly of the complex partial NCSE seizure (CPS) type (2). These patients were comatose and showed no overt clinical signs of convulsive activity. Clinical detection of NCSE in these patients would not have been possible with routine neurological evaluations without use of EEG monitoring. The clinical presentation, mortality, morbidity, and demographic information on this population are reported. Conclusions: Our results demonstrate that EEG monitoring after treatment of CSE is essential to recognition of persistent electrographic seizures and NCSE unresponsive to routine therapeutic management of CSE. These findings also suggest that EEG monitoring immediately after control of CSE is an important diagnostic test to guide treatment plans and to evaluate prognosis in the management of SE.  相似文献   
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Antibody polyspecificity and neutralization of HIV-1: a hypothesis   总被引:1,自引:0,他引:1  
HIV-1 has evolved many ways to evade protective host immune responses, thus creating a number of problems for HIV vaccine developers. In particular, durable, broadly specific neutralizing antibodies to HIV-1 have proved difficult to induce with current HIV-1 vaccine candidates. The recent observation that some broadly neutralizing anti-HIV-1 envelope monoclonal antibodies have polyspecific reactivities to host antigens have raised the hypothesis that one reason antibodies against some of the conserved HIV-1 envelope trimer neutralizing epitopes are not routinely made may be down-regulation of some specificities of anti-HIV-1 antibody producing B cells by host B cell tolerance mechanisms.  相似文献   
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