Biology subjects

Fiorentini, L.

Publications and source records attributed to Fiorentini, L..

4 recordsLinked to original sources

bioRxiv2026

Distinct Multimodal Imaging Correlates of Depression in Middle-Aged Adults With and Without a Family History of Alzheimer Disease

BackgroundDepression is associated with risk for late-onset Alzheimers disease (LOAD), but its underlying pathogenesis in at-risk individuals remains unclear. We examined multimodal imaging correlates of depressive symptoms in cognitively normal middle-aged offspring of patients with LOAD (O-LOAD) compared with control individuals without LOAD history up to a 4th degree of kinship (HC). MethodsParticipants (n=58; 52{+/-}3 years; 74% female) underwent assessment with the Beck Depression Inventory-II (BDI), structural MRI, resting-state fMRI, FDG-PET, and PiB-PET. Resting-state fMRI data were available for 28 O-LOAD and 24 HC; PET data for 24 O-LOAD and 22 HC. General linear models tested associations between imaging measures and BDI, including group interactions. ResultsIn O-LOAD, higher BDI scores were associated with reduced cortical thickness in the left postcentral gyrus. Resting-state fMRI revealed significant group-by-BDI interactions involving cingulate and orbitofrontal networks. In O-LOAD, greater depressive symptom severity was associated with reduced cingulate connectivity across distributed corticolimbic, prefrontal, insular, occipital, and cerebellar regions ({beta} range -0.10 to -0.18). In HC, depressive symptoms were associated with reduced right orbitofrontal and somatosensory-medial orbitofrontal connectivity ({beta}=-0.13), with divergent patterns of cingulate connectivity. FDG-PET showed no significant associations with depressive symptoms. PiB-PET demonstrated regionally specific associations between amyloid signal and BDI in HC, involving an inverse pattern in anterior and posterior insular cortices. ConclusionsDepressive symptoms in middle-aged individuals at familial risk for LOAD are associated with distinct structural and functional alterations, involving circuitry subserving salience and reward, and suggesting early network-level mechanisms linking affective symptoms with vulnerability to neurodegeneration.

neuroscience↗

bioRxiv2025

Structural Connectivity Correlates of Response to Electroconvulsive Therapy in Treatment-Resistant Depression

BackgroundElectroconvulsive therapy (ECT) is the most effective option for treatment resistant depression (TRD). In this study, we sought to explore if structural connectivity of limbic networks has an association with response to ECT. MethodsWe studied 23 patients with TRD who underwent a course of bifrontal ECT, employing probabilistic tractography at baseline to assess structural connectivity between the thalamus (THA), posterior (PCC), subgenual cingulate cortices, anterior insula (aINS), amygdala and orbitofrontal and ventrolateral prefrontal cortices, hypothesizing that these hubs participate in the formation and refractoriness of depression symptoms. We also include 21 healthy subject as controls group (HC). ResultsConnectivity between left THA and left PCC was related to both baseline depression severity (R=0.504; p= 0.017) and clinical response (R=0.452; p=0.004). Right aINS-prefrontal connectivity was associated with less clinical response. Structural connectivity was globally higher in patients than in HC (F=2.488; p=0.007). ConclusionsThe association of ECT response with stronger structural connectivity between hubs supporting self-referential bodily experience as well as autobiographical memory encoding and retrieval deserves exploration as a predictor in persons with TRD. In turn, the right aINS is a major hub for the salience network and is involved in repetitive negative mentation. Stronger structural connectivity of this region may be a heuristically valid biomarker for refractory TRD. We discuss the potential of the present findings for the design of anatomically precise neuromodulation interventions that would be useful to treat TRD while circumventing cognitive side effects of ECT.

neuroscience↗

bioRxiv2024

From North to South: Transmission Dynamics of H1N1pdm09 Swine Influenza A Viruses in Italy

The influenza A H1N1pdm09 virus continues to be a significant pathogen, posing potential risks to both animal and human health due to its zoonotic potential. Italy, which has one of the largest swine populations in Europe, plays a crucial role in monitoring the evolution of influenza viruses in livestock. This study aims to address the existing knowledge gaps regarding the genetic diversity and transmission dynamics of H1N1pdm09 circulating in Italian swine populations. Utilizing whole genome sequencing and dynamic modeling, we conducted a comprehensive analysis of virus samples collected from swine farms across Italy. Our results reveal that multiple independent viral introductions have occurred into the country, with most cases resulting in self-limited infections and limited onward transmission. However, six distinct transmission clusters were identified, suggesting instances of sustained viral spread. These clusters were found across multiple regions of Italy, highlighting the broad geographic distribution of virus lineages. Our findings indicate that while many introductions led to localized containment, certain virus lineages were able to spread within specific regions of Italy. Through a detailed examination of selective pressures, we observed that most viral genes are under strong purifying selection in both swine and human hosts, as reflected by dN/dS ratios well below 1. The hemagglutinin (HA) gene exhibited a notably higher dN/dS ratio in swine ([~]0.28) compared to humans ([~]0.22), indicating slightly relaxed selection in swine. In contrast, other genes, such as neuraminidase (NA) and non-structural protein (NS), showed similarly strong purifying selection across both hosts. These results reflect a general trend of selective pressures affecting multiple viral components, rather than emphasizing specific genes. Our study emphasizes the importance of ongoing genomic surveillance in detecting viral circulation and mitigating risks to both animal and public health. Italys efforts contribute significantly to global influenza monitoring and highlight the importance of a One Health approach that integrates human, animal, and environmental health. These findings provide essential data to inform public health policies and enhance preparedness against future zoonotic influenza outbreaks.

microbiology↗

bioRxiv2018

GI-16 lineage (624/I or Q1), there and back again: the history of one of the major threat for poultry farming of our era

The genetic variability of Infectious bronchitis virus (IBV) is one of the main challenges for its control, hindering not only the development of effective vaccination strategies but also its classification and, consequently, epidemiology understanding. The 624/I and Q1 genotypes, now recognized to be part of the GI-16 lineage, represent an excellent example of the practical consequences of IBV molecular epidemiology limited knowledge. In fact, being their common origin unrecognized for a long time, independent epidemiological pictures were drawn for the two genotypes. To fix this misinterpretation, the present study reconstructs the history, population dynamics and spreading patterns of GI-16 lineage as a whole using a phylodynamic approach. A collection of worldwide available hypervariable region 1 and 2 (HVR12) and 3 (HVR3) sequences of the S1 protein was analysed together with 258 HVR3 sequences obtained from samples collected in Italy (the country where this genotype was initially identified) since 1963. The results demonstrate that after its emergence at the beginning of the XX century, GI-16 was able to persist until present days in Italy. Approximately in the late 1980s, it migrated to Asia, which became the main nucleus for further spreading to Middle East, Europe and especially South America, likely through multiple introduction events. A remarkable among-country diffusion was also demonstrated in Asia and South America. Interestingly, although most of the recent Italian GI-16 strains originated from ancestral viruses detected in the same country, a couple were closely related to Chinese ones, supporting a backward viral flow from China to Italy.\n\nBesides to the specific case-study results, this work highlights the misconceptions that originate from the lack of a unified nomenclature and poor molecular epidemiology data generation and sharing. This shortcoming appears particularly relevant since the described scenario could likely be shared by many other IBV genotypes and pathogens in general.

evolutionary biology↗