Age, sex and APOE-ε4 modify the balance between soluble and fibrillar ß-amyloid in non-demented individuals: topographical patterns across two independent cohorts.

Amyloid (Aß) pathology is the earliest detectable pathophysiological event along the Alzheimer's continuum, which can be measured both in the cerebrospinal fluid (CSF) and by Positron Emission Tomography (PET). Yet, these biomarkers identify two distinct Aß pools, reflecting the clearance of soluble Aß as opposed to the presence of Aß fibrils in the brain. An open question is whether risk factors known to increase Alzheimer's' disease (AD) prevalence may promote an imbalance between soluble and deposited Aß. Unveiling such interactions shall aid our understanding of the biological pathways underlying Aß deposition and foster the design of effective prevention strategies. We assessed the impact of three major AD risk factors, such as age, APOE-ε4 and female sex, on the association between CSF and PET Aß, in two independent samples of non-demented individuals (ALFA: n = 320, ADNI: n = 682). We tested our hypotheses both in candidate regions of interest and in the whole brain using voxel-wise non-parametric permutations. All of the assessed risk factors induced a higher Aß deposition for any given level of CSF Aß42/40, although in distinct cerebral topologies. While age and sex mapped onto neocortical areas, the effect of APOE-ε4 was prominent in the medial temporal lobe, which represents a target of early tau deposition. Further, we found that the effects of age and APOE-ε4 was stronger in women than in men. Our data indicate that specific AD risk factors affect the spatial patterns of cerebral Aß aggregation, with APOE-ε4 possibly facilitating a co-localization between Aß and tau along the disease continuum.

Static versus Functional PET: Making Sense of Metabolic Connectivity.

Recently, Jamadar et al. (2021, Metabolic and hemodynamic resting-state connectivity of the human brain: a high-temporal resolution simultaneous BOLD-fMRI and FDG-fPET multimodality study. Cereb Cortex. 31(6), 2855-2867) compared the patterns of brain connectivity or covariance as obtained from 3 neuroimaging measures: 1) functional connectivity estimated from temporal correlations in the functional magnetic resonance imaging blood oxygen level-dependent signal, metabolic connectivity estimated, 2) from temporal correlations in 16-s frames of dynamic [18F]-fluorodeoxyglucose-positron emission tomography (FDG-PET), which they designate as functional FDG-PET (fPET), and 3) from intersubject correlations in static FDG-PET images (sPET). Here, we discuss a number of fundamental issues raised by the Jamadar study. These include the choice of terminology, the interpretation of cross-modal findings, the issue of group- to single-subject level inferences, and the meaning of metabolic connectivity as a biomarker. We applaud the methodological approach taken by the authors, but wish to present an alternative perspective on their findings. In particular, we argue that sPET and fPET can both provide valuable information about brain connectivity. Certainly, resolving this conundrum calls for further experimental and theoretical efforts to advance the developing framework of PET-based brain connectivity indices.

Lifelong bilingualism and mechanisms of neuroprotection in Alzheimer dementia.

Lifelong bilingualism is associated with delayed dementia onset, suggesting a protective effect on the brain. Here, we aim to study the effects of lifelong bilingualism as a dichotomous and continuous phenomenon, on brain metabolism and connectivity in individuals with Alzheimer's dementia. Ninety-eight patients with Alzheimer's dementia (56 monolinguals; 42 bilinguals) from three centers entered the study. All underwent an [18F]-fluorodeoxyglucose positron emission tomography (PET) imaging session. A language background questionnaire measured the level of language use for conversation and reading. Severity of brain hypometabolism and strength of connectivity of the major neurocognitive networks was compared across monolingual and bilingual individuals, and tested against the frequency of second language life-long usage. Age, years of education, and MMSE score were included in all above mentioned analyses as nuisance covariates. Cerebral hypometabolism was more severe in bilingual compared to monolingual patients; severity of hypometabolism positively correlated with the degree of second language use. The metabolic connectivity analyses showed increased connectivity in the executive, language, and anterior default mode networks in bilingual compared to monolingual patients. The change in neuronal connectivity was stronger in subjects with higher second language use. All effects were most pronounced in the left cerebral hemisphere. The neuroprotective effects of lifelong bilingualism act both against neurodegenerative processes and through the modulation of brain networks connectivity. These findings highlight the relevance of lifelong bilingualism in brain reserve and compensation, supporting bilingual education and social interventions aimed at usage, and maintenance of two or more languages, including dialects, especially crucial in the elderly people.

Longitudinal pathways of cerebrospinal fluid and positron emission tomography biomarkers of amyloid-ß positivity.

Mismatch between CSF and PET amyloid-ß biomarkers occurs in up to ≈20% of preclinical/prodromal Alzheimer's disease individuals. Factors underlying mismatching results remain unclear. In this study we hypothesized that CSF/PET discordance provides unique biological/clinical information. To test this hypothesis, we investigated non-demented and demented participants with CSF amyloid-ß42 and [18F]Florbetapir PET assessments at baseline (n = 867) and at 2-year follow-up (n = 289). Longitudinal trajectories of amyloid-ß positivity were tracked simultaneously for CSF and PET biomarkers. In the longitudinal cohort (n = 289), we found that participants with normal CSF/PET amyloid-ß biomarkers progressed more frequently toward CSF/PET discordance than to full CSF/PET positivity (χ2(1) = 5.40; p < 0.05). Progression to CSF+/PET+ status was ten times more frequent in cases with discordant biomarkers, as compared to csf-/pet- cases (χ2(1) = 18.86; p < 0.001). Compared to the CSF+/pet- group, the csf-/PET+ group had lower APOE-ε4ε4 prevalence (χ2(6) = 197; p < 0.001; n = 867) and slower rate of brain amyloid-ß accumulation (F(3,600) = 12.76; p < 0.001; n = 608). These results demonstrate that biomarker discordance is a typical stage in the natural history of amyloid-ß accumulation, with CSF or PET becoming abnormal first and not concurrently. Therefore, biomarker discordance allows for identification of individuals with elevated risk of progression toward fully abnormal amyloid-ß biomarkers, with subsequent risk of neurodegeneration and cognitive decline. Our results also suggest that there are two alternative pathways ("CSF-first" vs. "PET-first") toward established amyloid-ß pathology, characterized by different genetic profiles and rates of amyloid-ß accumulation. In conclusion, CSF and PET amyloid-ß biomarkers provide distinct information, with potential implications for their use as biomarkers in clinical trials.

Clinical impact of 18F-FDG-PET among memory clinic patients with uncertain diagnosis.

PURPOSE: To assess the clinical impact and incremental diagnostic value of 18F-fluorodeoxyglucose (FDG-PET) among memory clinic patients with uncertain diagnosis. METHODS: The study population consisted of 277 patients who, despite extensive baseline cognitive assessment, MRI, and CSF analyses, had an uncertain diagnosis of mild cognitive impairment (MCI) (n = 177) or dementia (n = 100). After baseline diagnosis, each patient underwent an FDG-PET, followed by a post-FDG-PET diagnosis formulation. We evaluated (i) the change in diagnosis (baseline vs. post-FDG-PET), (ii) the change in diagnostic accuracy when comparing each baseline and post-FDG-PET diagnosis to a long-term follow-up (3.6 ± 1.8 years) diagnosis used as reference, and (iii) comparative FDG-PET performance testing in MCI and dementia conditions. RESULTS: FDG-PET led to a change in diagnosis in 86 of 277 (31%) patients, in particular in 57 of 177 (32%) MCI and in 29 of 100 (29%) dementia patients. Diagnostic change was greater than two-fold in the sub-sample of cases with dementia "of unclear etiology" (change in diagnosis in 20 of 32 (63%) patients). In the dementia group, after results of FDG-PET, diagnostic accuracy improved from 77 to 90% in Alzheimer's disease (AD) and from 85 to 94% in frontotemporal lobar degeneration (FTLD) patients (p < 0.01). FDG-PET performed better in dementia than in MCI (positive likelihood ratios >5 and < 5, respectively). CONCLUSION: Within a selected clinical population, FDG-PET has a significant clinical impact, both in early and differential diagnosis of uncertain dementia. FDG-PET provides significant incremental value to detect AD and FTLD over a clinical diagnosis of uncertain dementia.

Validation of FDG-PET datasets of normal controls for the extraction of SPM-based brain metabolism maps.

PURPOSE: An appropriate healthy control dataset is mandatory to achieve good performance in voxel-wise analyses. We aimed at evaluating [18F]FDG PET brain datasets of healthy controls (HC), based on publicly available data, for the extraction of voxel-based brain metabolism maps at the single-subject level. METHODS: Selection of HC images was based on visual rating, after Cook's distance and jack-knife analyses, to exclude artefacts and/or outliers. The performance of these HC datasets (ADNI-HC and AIMN-HC) to extract hypometabolism patterns in single patients was tested in comparison with the standard reference HC dataset (HSR-HC) by means of Dice score analysis. We evaluated the performance and comparability of the different HC datasets in the assessment of single-subject SPM-based hypometabolism in three independent cohorts of patients, namely, ADD, bvFTD and DLB. RESULTS: Two-step Cook's distance analysis and the subsequent jack-knife analysis resulted in the selection of n = 125 subjects from the AIMN-HC dataset and n = 75 subjects from the ADNI-HC dataset. The average concordance between SPM hypometabolism t-maps in the three patient cohorts, as obtained with the new datasets and compared to the HSR-HC standard reference dataset, was 0.87 for the AIMN-HC dataset and 0.83 for the ADNI-HC dataset. Pattern expression analysis revealed high overall accuracy (> 80%) of the SPM t-map classification according to different statistical thresholds and sample sizes. CONCLUSIONS: The applied procedures ensure validity of these HC datasets for the single-subject estimation of brain metabolism using voxel-wise comparisons. These well-selected HC datasets are ready-to-use in research and clinical settings.

In vitro virucidal efficacy of a dry steam disinfection system against Human Coronavirus, Human Influenza Virus, and Echovirus.

This in vitro study was aimed to assess the efficacy of dry steam in inactivating Human Coronavirus OC43 (HCoV-OC43) as surrogate of SARS-CoV-2, Human Influenza Virus A/H1N1/WSN/33 and Echovirus 7 on stainless steel, polypropylene, and cotton. The virus models were chosen on the basis of their transmission route and environmental resistance. Tests were carried out under a laminar flow cabinet, where two panels of each material were contaminated with a viral suspension. The inocula were left to dry and then the virus on untreated panel (control) was collected by swabbing in order to determine the initial titer. The other panel was treated using a professional vacuum cleaner equipped with a dry steam generator. Dry steam is generated in a boiler where tap water is heated up to 155 °C at 5.5 bar pressure and then during the passage along the flexible hose the temperature decreases to a value between 100 °C and 110 °C at the output. The dry steam was applied for four sec with a window wiper on metal and plastic panels or a brush covered by a microfiber cap on cotton, simulating the steam application during routine cleaning. After the treatment, infectious virus possibly remained on the surface was collected following the same swabbing procedure applied for controls. HCoV-OC43 and Echovirus 7 were titrated by end-point method on HCT-8 line cells and Vero cells, respectively, while Human Influenza Virus was quantified by plaque reduction assay on MDCK cells. Dry steam resulted effective against the three viruses on all tested materials, achieving a mean Log10 reduction factor ≥4 in viral titer of treated samples compared with controls according to UNI EN 14476:2019. Thus, dry steam may be proposed as an ease to use, effective, fast, and nontoxic alternative to chemicals for surface disinfection without damaging materials. Therefore, this device could be employed not only in healthcare facilities but also in occupational, domestic, and community settings, with advantages for environment and human health.

Brain metabolic signatures across the Alzheimer's disease spectrum.

PURPOSE: Given the challenges posed by the clinical diagnosis of atypical Alzheimer's disease (AD) variants and the limited imaging evidence available in the prodromal phases of atypical AD, we assessed brain hypometabolism patterns at the single-subject level in the AD variants spectrum. Specifically, we tested the accuracy of [18F]FDG-PET brain hypometabolism, as a biomarker of neurodegeneration, in supporting the differential diagnosis of atypical AD variants in individuals with dementia and mild cognitive impairment (MCI). METHODS: We retrospectively collected N = 67 patients with a diagnosis of typical AD and AD variants according to the IWG-2 criteria (22 typical-AD, 15 frontal variant-AD, 14 logopenic variant-AD and 16 posterior variant-AD). Further, we included N = 11 MCI subjects, who subsequently received a clinical diagnosis of atypical AD dementia at follow-up (21 ± 11 months). We assessed brain hypometabolism patterns at group- and single-subject level, using W-score maps, measuring their accuracy in supporting differential diagnosis. In addition, the regional prevalence of cerebral hypometabolism was computed to identify the most vulnerable core regions. RESULTS: W-score maps pointed at distinct, specific patterns of hypometabolism in typical and atypical AD variants, confirmed by the assessment of core hypometabolism regions, showing that each variant was characterized by specific regional vulnerabilities, namely in occipital, left-sided, or frontal brain regions. ROC curves allowed discrimination among AD variants and also non-AD dementia (i.e., dementia with Lewy bodies and behavioral variant of frontotemporal dementia), with high sensitivity and specificity. Notably, we provide preliminary evidence that, even in AD prodromal phases, these specific [18F]FDG-PET patterns are already detectable and predictive of clinical progression to atypical AD variants at follow-up. CONCLUSIONS: The AD variant-specific patterns of brain hypometabolism, highly consistent at single-subject level and already evident in the prodromal stages, represent relevant markers of disease neurodegeneration, with highly supportive diagnostic and prognostic role.

CSF p-tau/Aß42 ratio and brain FDG-PET may reliably detect MCI "imminent" converters to AD.

PURPOSE: To know whether mild cognitive impairment (MCI) patients will develop Alzheimer's disease (AD) dementia in very short time or remain stable is of crucial importance, also considering new experimental drugs usually tested within very short time frames. Here we combined cerebrospinal fluid (CSF) AD biomarkers and a neurodegeneration marker such as brain FDG-PET to define an objective algorithm, suitable not only to reliably detect MCI converters to AD dementia but also to predict timing of conversion. METHODS: We included 77 consecutive MCI patients with neurological/neuropsychological assessment, brain 18F-FDG-PET and CSF analysis available at diagnosis and a neuropsychological/neurological evaluation every 6 months for a medium- to a long-term follow-up (at least 2 and up to 8 years). Binomial logistic regression models and Kaplan-Meier survival analyses were performed to determine the best biomarker (or combination of biomarkers) in detecting MCI converters to AD dementia and then, among the converters, those who converted in short time frames. RESULTS: Thirty-five out of 77 MCI patients (45%) converted to AD dementia, with an average conversion time since MCI diagnosis of 26.07 months. CSF p-tau/Aß42 was the most accurate predictor of conversion from MCI to AD dementia (82.9% sensitivity; 90% specificity). CSF p-tau/Aß42 and FDG-PET-positive MCIs converted to AD dementia significantly earlier than the CSF-positive-only MCIs (median conversion time, 17.1 vs 31.3 months). CONCLUSIONS: CSF p-tau/Aß42 ratio and brain FDG-PET may predict both occurrence and timing of MCI conversion to full-blown AD dementia. MCI patients with both biomarkers suggestive for AD will likely develop an AD dementia shortly, thus representing the ideal target for any new experimental drug requiring short periods to be tested for.

Vulnerability of multiple large-scale brain networks in dementia with Lewy bodies.

Aberrations of large-scale brain networks are found in the majority of neurodegenerative disorders. The brain connectivity alterations underlying dementia with Lewy bodies (DLB) remain, however, still elusive, with contrasting results possibly due to the pathological and clinical heterogeneity characterizing this disorder. Here, we provide a molecular assessment of brain network alterations, based on cerebral metabolic measurements as proxies of synaptic activity and density, in a large cohort of DLB patients (N = 72). We applied a seed-based interregional correlation analysis approach (p < .01, false discovery rate corrected) to evaluate large-scale resting-state networks' integrity and their interactions. We found both local and long-distance metabolic connectivity alterations, affecting the posterior cortical networks, that is, primary visual and the posterior default mode network, as well as the limbic and attention networks, suggesting a widespread derangement of the brain connectome. Notably, patients with the lowest visual and attention cognitive scores showed the most severe connectivity derangement in regions of the primary visual network. In addition, network-level alterations were differentially associated with the core clinical manifestations, namely, hallucinations with more severe metabolic dysfunction of the attention and visual networks, and rapid eye movement sleep behavior disorder with alterations of connectivity of attention and subcortical networks. These multiple network-level vulnerabilities may modulate the core clinical and cognitive features of DLB and suggest that DLB should be considered as a complex multinetwork disorder.

Testing the diagnostic accuracy of [18F]FDG-PET in discriminating spinal- and bulbar-onset amyotrophic lateral sclerosis.

PURPOSE: The role for [18F]FDG-PET in supporting amyotrophic lateral sclerosis (ALS) diagnosis is not fully established. In this study, we aim at evaluating [18F]FDG-PET hypo- and hyper-metabolism patterns in spinal- and bulbar-onset ALS cases, at the single-subject level, testing the diagnostic value in discriminating the two conditions, and the correlations with core clinical symptoms severity. METHODS: We included 95 probable-ALS patients with [18F]FDG-PET scan and clinical follow-up. [18F]FDG-PET images were analyzed with an optimized voxel-based-SPM method. The resulting single-subject SPM-t maps were used to: (a) assess brain regional hypo- and hyper-metabolism; (b) evaluate the accuracy of regional hypo- and hyper metabolism in discriminating spinal vs. bulbar-onset ALS; (c) perform correlation analysis with motor symptoms severity, as measured by ALS-FRS-R. RESULTS: Primary motor cortex showed the most frequent hypo-metabolism in both spinal-onset (∼57%) and bulbar-onset (∼64%) ALS; hyper-metabolism was prevalent in the cerebellum in both spinal-onset (∼56.5%) and bulbar-onset (∼55.7%) ALS, and in the occipital cortex in bulbar-onset (∼62.5%) ALS. Regional hypo- and hyper-metabolism yielded a very low accuracy (AUC < 0.63) in discriminating spinal- vs. bulbar-onset ALS, as obtained from single-subject SPM-t-maps. Severity of motor symptoms correlated with hypo-metabolism in sensorimotor cortex in spinal-onset ALS, and with cerebellar hyper-metabolism in bulbar-onset ALS. CONCLUSIONS: The high variability in regional hypo- and hyper-metabolism patterns, likely reflecting the heterogeneous pathology and clinical phenotypes, limits the diagnostic potential of [18F]FDG-PET in discriminating spinal and bulbar onset patients.

Real-time monitoring of Pseudomonas aeruginosa biofilm formation on endotracheal tubes in vitro.

BACKGROUND: Pseudomonas aeruginosa is an opportunistic bacterial pathogen responsible for both acute and chronic infections in humans. In particular, its ability to form biofilm, on biotic and abiotic surfaces, makes it particularly resistant to host's immune defenses and current antibiotic therapies as well. Innovative antimicrobial materials, like hydrogel, silver salts or nanoparticles have been used to cover new generation catheters with promising results. Nevertheless, biofilm remains a major health problem. For instance, biofilm produced onto endotracheal tubes (ETT) of ventilated patients plays a relevant role in the onset of ventilation-associated pneumonia. Most of our knowledge on Pseudomonas aeruginosa biofilm derives from in vitro studies carried out on abiotic surfaces, such as polystyrene microplates or plastic materials used for ETT manufacturing. However, these approaches often provide underestimated results since other parameters, in addition to bacterial features (i.e. shape and material composition of ETT) might strongly influence biofilm formation. RESULTS: We used an already established biofilm development assay on medically-relevant foreign devices (CVC catheters) by a stably transformed bioluminescent (BLI)-Pseudomonas aeruginosa strain, in order to follow up biofilm formation on ETT by bioluminescence detection. Our results demonstrated that it is possible: i) to monitor BLI-Pseudomonas aeruginosa biofilm development on ETT pieces in real-time, ii) to evaluate the three-dimensional structure of biofilm directly on ETT, iii) to assess metabolic behavior and the production of microbial virulence traits of bacteria embedded on ETT-biofilm. CONCLUSIONS: Overall, we were able to standardize a rapid and easy-to-perform in vitro model for real-time monitoring Pseudomonas aeruginosa biofilm formation directly onto ETT pieces, taking into account not only microbial factors, but also ETT shape and material. Our study provides a rapid method for future screening and validation of novel antimicrobial drugs as well as for the evaluation of novel biomaterials employed in the production of new classes of ETT.

Symptomatic cerebrospinal fluid HIV-1 escape with no resistance-associated mutations following low-level plasma viremia.

The majority of neurologically symptomatic cerebrospinal fluid HIV-1 escape cases are connected with resistance-associated mutations and potentially explained by low cerebrospinal fluid antiretroviral concentrations. However, there are still significant knowledge gaps regarding the physiopathology and long-term management of neurosymptomatic viral escape. We report a case of Parkinson-like syndrome following cerebrospinal fluid HIV-1 escape in a 40-year-old female patient with an history of persistent low-level plasma viremia under treatment. No resistance-associated mutations, high viral diversity (env deep sequencing), adequate pharmacokinetics, atypical CD3-CD14-CD4+CD5-CD2-/+CD7-/+ lymphocytes, low-level Epstein-Barr virus replication, and white matter autoimmune reactivity were observed in the cerebrospinal fluid. Antiretroviral regimen modification led to rapid clinical and radiological improvements. This case may increase the current uncertain knowledge on the origin of cerebrospinal fluid HIV-1 and illustrates the consequences of uncontrolled compartmental viral replication; it also highlights the relevance and persistence of immune activation and the possibility of various detrimental mechanisms underlying neurosymptomatic viral escape.

Antiviral Activity of Synthetic Peptides Derived from Physiological Proteins.

BACKGROUND/AIMS: New antivirals are needed to supplement or replace currently used drugs. The aim of this study was to evaluate the antiviral activity of synthetic peptides derived from physiological proteins. METHODS: Vero cell monolayers were infected with herpes simplex virus 1, vesicular stomatitis virus, adenovirus, and coxsackievirus B5 strains in the presence of different concentrations of the selected peptides and viral yield was determined by plaque reduction assays to evaluate the antiviral activity of the peptides. Virucidal activity was evaluated by determining the residual infectivity of viral suspensions treated for 1 h with the peptides at the same concentrations as in the viral yield assays. RESULTS: Among the investigated peptides, the killer peptide proved to exert a considerable antiviral activity against herpes simplex virus, attributable to a direct effect on virus particles, while its derivative K10S showed to be effective against the four investigated virus strains only at the highest concentration tested, yet, the inhibitory effects were only partial. CONCLUSION: Overall, initial evidence is provided on the antiviral activity of several peptides, as well as of their derivatives. Further investigation is warranted to ascertain the mechanism of action in order to develop new potential antiviral drugs.

Herpes simplex virus-1 entrapped in Candida albicans biofilm displays decreased sensitivity to antivirals and UVA1 laser treatment.

BACKGROUND: Recently, we published data suggesting a mutualistic relationship between HSV-1 and Candida. albicans; in particular: (a) HSV-1 infected macrophages are inhibited in their anti-Candida effector function and (b) Candida biofilm protects HSV-1 from inactivation. The present in vitro study is aimed at testing the effects of Candida biofilm on HSV-1 sensitivity to pharmacological and physical stress, such as antiviral drugs (acyclovir and foscarnet) and laser UVA1 irradiation. We also investigated whether fungus growth pattern, either sessile or planktonic, influences HSV-1 sensitivity to antivirals. METHODS: Mature Candida biofilms were exposed to HSV-1 and then irradiated with laser light (UVA1, 355 λ). In another set of experiments, mature Candida biofilm were co-cultured with HSV-1 infected VERO cells in the presence of different concentrations of acyclovir or foscarnet. In both protocols, controls unexposed to laser or drugs were included. The viral yield of treated and untreated samples was evaluated by end-point titration. To evaluate whether this protective effect might occur in relation with a different growth pattern, HSV-1 infected cells were co-cultured with either sessile or planktonic forms of Candida and then assessed for susceptibility to antiviral drugs. RESULTS: UVA1 irradiation caused a 2 Log reduction of virus yield in the control cultures whereas the reduction was only 1 Log with Candida biofilm, regardless to the laser dose applied to the experimental samples (50 or 100 J/cm2). The presence of biofilm increased the IC90 from 18.4-25.6 J/cm2. Acyclovir caused a 2.3 Log reduction of virus yield in the control cultures whereas with Candida biofilm the reduction was only 0.5 Log; foscarnet determined a reduction of 1.4 Log in the controls and 0.2 Log in biofilm cultures. Consequently, the ICs50 for acyclovir and foscarnet increased by 4- and 12-folds, respectively, compared to controls. When HSV-1 was exposed to either sessile or planktonic fungal cells, the antiviral treatments caused approximately the same weak reduction of virus yield. CONCLUSIONS: These data demonstrate that: (1) HSV-1 encompassed in Candida biofilm is protected from inactivation by physical (laser) and pharmacological (acyclovir or foscarnet) treatments; (2) the drug antiviral activity is reduced at a similar extent for both sessile or planktonic Candida.

Diagnostics of the neuromyelitis optica spectrum disorders (NMOSD).

This document presents the guidelines for anti-aquaporin-4 (AQP4) antibody testing that has been developed following a consensus process built on questionnaire-based surveys, internet contacts, and discussions at workshops of the sponsoring Italian Association of Neuroimmunology (AINI) congresses. Essential clinical information on neuromyelitis optica spectrum disorders, indications and limits of anti-AQP4 antibody testing, instructions for result interpretation, and an agreed laboratory protocol (Appendix) are reported for the communicative community of neurologists and clinical pathologists.

Cerebrospinal fluid analysis and the determination of oligoclonal bands.

This document presents the guidelines for the cerebrospinal fluid (CSF) analysis and the determination of oligoclonal bands (OCBs) as pivotal tests in neuroinflammatory pathologies of the central nervous system. The guidelines have been developed following a consensus process built on questionnaire-based surveys, internet contacts, and discussions at workshops of the sponsoring Italian Association of Neuroimmunology (AINI) congresses. Essential clinical information on the pathologies in which the CSF analysis is indicated, and, particularly, on those characterized by the presence of OCBs in the intrathecal compartment, indications and limits of CSF analysis and OCB determination, instructions for result interpretation, and agreed laboratory protocols (Appendix) are reported for the communicative community of neurologists and clinical pathologists.

Virus-Mediated Metalloproteinase 1 Induction Revealed by Transcriptome Profiling of Bovine Herpesvirus 4-Infected Bovine Endometrial Stromal Cells.

Viral infections can cause genital tract disorders (including abortion) in cows, and bovine herpesvirus 4 (BoHV-4) is often present in endometritis-affected animals. A major problem with cattle uterine viral infections in general, and BoHV-4 in particular, is our limited understanding of the pathogenic role(s) that these infections play in the endometrium. A similar lack of knowledge holds for the molecular mechanisms utilized, and the host cell pathways affected, by BoHV-4. To begin to fill these gaps, we set up optimized conditions for BoHV-4 infection of a pure population of bovine endometrial stromal cells (BESCs) to be used as source material for RNA sequencing-based transcriptome profiling. Many genes were found to be upregulated (417) or downregulated (181) after BoHV-4 infection. As revealed by enrichment functional analysis on differentially expressed genes, BoHV-4 infection affects various pathways related to cell proliferation and cell surface integrity, at least three of which were centered on upregulation of matrix metalloproteinase 1 (MMP1) and interleukin 8 (IL8). This was confirmed by reverse transcription PCR, real-time PCR, Western-immunoblot analysis, and a luciferase assay with a bovine MMP1-specific promoter reporter construct. Further, it was found that MMP1 transcription was upregulated by the BoHV-4 transactivator IE2/RTA, leading to abnormally high metalloproteinase tissue levels, potentially leading to defective endometrium healing and unresolved inflammation. Based on these findings, we propose a new model for BoHV-4 action centered on IE2-mediated MMP1 upregulation and novel therapeutic interventions based on IFN gamma-mediated MMP1 downregulation.

Similarity between structural and proxy estimates of brain connectivity.

Functional magnetic resonance and diffusion weighted imaging have so far made a major contribution to delineation of the brain connectome at the macroscale. While functional connectivity (FC) was shown to be related to structural connectivity (SC) to a certain degree, their spatial overlap is unknown. Even less clear are relations of SC with estimates of connectivity from inter-subject covariance of regional F18-fluorodeoxyglucose uptake (FDGcov) and grey matter volume (GMVcov). Here, we asked to what extent SC underlies three proxy estimates of brain connectivity: FC, FDGcov and GMVcov. Simultaneous PET/MR acquisitions were performed in 56 healthy middle-aged individuals. Similarity between four networks was assessed using Spearman correlation and convergence ratio (CR), a measure of spatial overlap. Spearman correlation coefficient was 0.27 for SC-FC, 0.40 for SC-FDGcov, and 0.15 for SC-GMVcov. Mean CRs were 51% for SC-FC, 48% for SC-FDGcov, and 37% for SC-GMVcov. These results proved to be reproducible and robust against image processing steps. In sum, we found a relevant similarity of SC with FC and FDGcov, while GMVcov consistently showed the weakest similarity. These findings indicate that white matter tracts underlie FDGcov to a similar degree as FC, supporting FDGcov as estimate of functional brain connectivity.

Continuous ß-Amyloid CSF/PET Imbalance Model to Capture Alzheimer Disease Heterogeneity.

BACKGROUND AND OBJECTIVES: Discordance between CSF and PET biomarkers of ß-amyloid (Aß) might reflect an imbalance between soluble and aggregated species, possibly reflecting disease heterogeneity. Previous studies generally used binary cutoffs to assess discrepancies in CSF/PET biomarkers, resulting in a loss of information on the extent of discordance. In this study, we (1) jointly modeled Aß-CSF/PET data to derive a continuous measure of the imbalance between soluble and fibrillar pools of Aß, (2) investigated factors contributing to this imbalance, and (3) examined associations with cognitive trajectories. METHODS: Across 822 cognitively unimpaired (n = 261) and cognitively impaired (n = 561) Alzheimer's Disease Neuroimaging Initiative individuals (384 [46.7%] females, mean age 73.0 ± 7.4 years), we fitted baseline CSF-Aß42 and global Aß-PET to a hyperbolic regression model, deriving a participant-specific Aß-aggregation score (standardized residuals); negative values represent more soluble relative to aggregated Aß and positive values more aggregated relative to soluble Aß. Using linear models, we investigated whether methodological factors, demographics, CSF biomarkers, and vascular burden contributed to Aß-aggregation scores. With linear mixed models, we assessed whether Aß-aggregation scores were predictive of cognitive functioning. Analyses were repeated in an early independent validation cohort of 383 Amyloid Imaging to Prevent Alzheimer's Disease Prognostic and Natural History Study individuals (224 [58.5%] females, mean age 65.2 ± 6.9 years). RESULTS: The imbalance model could be fit (pseudo-R2 = 0.94) in both cohorts, across CSF kits and PET tracers. Although no associations were observed with the main methodological factors, lower Aß-aggregation scores were associated with larger ventricular volume (ß = 0.13, p < 0.001), male sex (ß = -0.18, p = 0.019), and homozygous APOE-ε4 carriership (ß = -0.56, p < 0.001), whereas higher scores were associated with increased uncorrected CSF p-tau (ß = 0.17, p < 0.001) and t-tau (ß = 0.16, p < 0.001), better baseline executive functioning (ß = 0.12, p < 0.001), and slower global cognitive decline (ß = 0.14, p = 0.006). In the validation cohort, we replicated the associations with APOE-ε4, CSF t-tau, and, although modestly, with cognition. DISCUSSION: We propose a novel continuous model of Aß CSF/PET biomarker imbalance, accurately describing heterogeneity in soluble vs aggregated Aß pools in 2 independent cohorts across the full Aß continuum. Aß-aggregation scores were consistently associated with genetic and AD-associated CSF biomarkers, possibly reflecting disease heterogeneity beyond methodological influences.