A chronic cavitary form of pulmonary aspergillosis may occur with mild immunosuppression or underlying lung disease. In this "semi-invasive" type, the fungus is intermediate between a simple saprophyte and an invasive pathogen. Aspergillus may produce extensive lung destruction despite the lack of vascular invasion. The absence of a previous cavity distinguishes such cases from secondary noninvasive mycetomas. Radiographic features include a chronic infiltrate, progressive cavitation, and subsequent mycetoma formation. Biopsy may be helpful; however, marked squamous metaplasia can produce false-positive Class V cytological findings even though malignancy is excluded. This variety of aspergillosis supports the concept that the traditional allergic, saprophytic, and invasive forms may represent a spectrum of disease dependent on host immune status and lung architecture.
This cross-sectional brain volumetric study indicates structural alterations early in HIV infection. The findings challenge the prevailing assumption that the brain is spared in this period. Revisiting the question of the brain's vulnerability to processes unfolding in the initial virus-host interaction and the early natural history may yield new insights into neurologic injury in HIV infection and inform neuroprotection strategies.
Limited information is available concerning changes that occur in the brain early in human immunodeficiency virus (HIV) infection. This investigation evaluated resting-state functional connectivity, which is based on correlations of spontaneous blood oxygen level-dependent functional magnetic resonance imaging (fMRI) oscillations between brain regions, in 15 subjects within the first year of HIV infection and in 15 age-matched controls. Resting-state fMRI data for each session were concatenated in time across subjects to create a single 4D dataset and decomposed into 36 independent component analysis (ICA) using Multivariate Exploratory Linear Optimized Decomposition into Independent Components. ICA components were back-reconstructed for each subject's 4D data to estimate subject-specific spatial maps using the dual-regression technique. Comparison of spatial maps between HIV and controls revealed significant differences in the lateral occipital cortex (LOC) network. Reduced coactivation in left inferior parietal cortex within the LOC network was identified in the HIV subjects. Connectivity strength within this region correlated with performance on tasks involving visual-motor coordination (Grooved Pegboard and Rey Figure Copy) in the HIV group. The findings indicate prominent changes in resting-state functional connectivity of visual networks early in HIV infection. This network may sustain injury in association with the intense viremia and brain viral invasion before immune defenses can contain viral replication. Resting-state functional connectivity may have utility as a noninvasive neuroimaging biomarker for central nervous system impairment in early HIV infection.
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