Autism Spectrum Disorder and screen time during lockdown: an Italian study.

Background: Lockdown due to Covid-19 pandemic brought deep changes to the daily lives of children with Autism Spectrum Disorder (ASD), greatly increasing their amount of time spent at home. Methods: A cohort of 243 parents of children with ASD (2-15 years old) completed an original online survey regarding the child's screen time and the modification of the ASD symptomatology during lockdown to investigate the relationship between them. Results: The data show that high solitary screen time is related with the worsening of ASD core symptoms. Conclusions: This study may help to increase awareness in the excessive use of screen in children with ASD during the lockdown, both during the pandemic as well as after it ends

Quantifying interactions between accommodation and vergence in a binocularly normal population

AbstractStimulation of the accommodation system results in a response in the vergence system via accommodative vergence cross-link interactions, and stimulation of the vergence system results in an accommodation response via vergence accommodation cross-link interactions. Cross-link interactions are necessary in order to ensure simultaneous responses in the accommodation and vergence systems. The crosslink interactions are represented most comprehensively by the response AC/A (accommodative vergence) and CA/C (vergence accommodation) ratios, although the stimulus AC/A ratio is measured clinically, and the stimulus CA/C ratio is seldom measured in clinical practice. The present study aims to quantify both stimulus and response AC/A and CA/C ratios in a binocularly normal population, and determine the relationship between them. 25 Subjects (mean±SD age 21.0±1.9years) were recruited from the university population. A significant linear relationship was found between the stimulus and response ratios, for both AC/A (r2=0.96, p<0.001) and CA/C ratios (r2=0.40, p<0.05). Good agreement was found between the stimulus and response AC/A ratios (95% CI −0.06 to 0.24MA/D). Stimulus and response CA/C ratios are linearly related. Stimulus CA/C ratios were higher than response ratios at low values, and lower than response ratios at high values (95% CI −0.46 to 0.42D/MA). Agreement between stimulus and response CA/C ratios is poorer than that found for AC/A ratios due to increased variability in vergence responses when viewing the Gaussian blurred target. This study has shown that more work is needed to refine the methodology of CA/C ratio measurement

Broadly directed virus-specific CD4+ T cell responses are primed during acute hepatitis C infection, but rapidly disappear from human blood with viral persistence

Vigorous proliferative CD4+ T cell responses are the hallmark of spontaneous clearance of acute hepatitis C virus (HCV) infection, whereas comparable responses are absent in chronically evolving infection. Here, we comprehensively characterized the breadth, specificity, and quality of the HCV-specific CD4+ T cell response in 31 patients with acute HCV infection and varying clinical outcomes. We analyzed in vitro T cell expansion in the presence of interleukin-2, and ex vivo staining with HCV peptide-loaded MHC class II tetramers. Surprisingly, broadly directed HCV-specific CD4+ T cell responses were universally detectable at early stages of infection, regardless of the clinical outcome. However, persistent viremia was associated with early proliferative defects of the HCV-specific CD4+ T cells, followed by rapid deletion of the HCV-specific response. Only early initiation of antiviral therapy was able to preserve CD4+ T cell responses in acute, chronically evolving infection. Our results challenge the paradigm that HCV persistence is the result of a failure to prime HCV-specific CD4+ T cells. Instead, broadly directed HCV-specific CD4+ T cell responses are usually generated, but rapid exhaustion and deletion of these cells occurs in the majority of patients. The data further suggest a short window of opportunity to prevent the loss of CD4+ T cell responses through antiviral therapy

Biophysical characterisation of P. falciparum infected-red blood cells: consequences for diagnosis

Diagnosis of malaria in asymptomatic individuals is hampered by the lack of tools able to detect very low parasite densities. Microfluidics is emerging as a possible approach to address this issue. In particular, label-free sorting (i.e. exploiting the cell biophysical properties) of P. falciparum-infected red blood cells (iRBCs) from uninfected cells, and subsequent enrichment of parasite-infected RBCs within a blood sample may be an efficient and cost-effective way to increase the sensitivity of available methods used for malaria diagnosis in the field. However, the development of any sorting device based on cell biophysical properties requires a priori knowledge of when the difference in these properties between infected and uninfected RBCs (uRBCs) occurs. By the employment of leading-edge techniques in the field (real-time deformability cytometry (RT-DC) and microfluidic impedance cytometry (MIC)), the mechanical and dielectric properties of infected and uRBCs were studied over the P. falciparum-intraerythrocytic life cycle in vitro. Significant differences in biophysical properties between iRBCs and uRBCs occurred at around 12 hours post-invasion (hpi). Furthermore, the parasite age (defined as hpi) of P. falciparum parasites in vivo was also studied using a newly-developed method. This method applied real-time quantitative PCR (RT-qPCR) of three time-specific genes which are differentially expressed over the ring stage of the parasite, the only stage present in the peripheral blood of an infected person. Results obtained from the RT-qPCR analysis of highly synchronised in vitro grown ring-stage parasites at different times post-invasion were used to generate a predictive model which allowed the estimation of parasite ages (hpi). Moreover, discrimination between synchronous (with a single parasite age) or asynchronous (with multiple parasite ages) infections was achieved in naturally infected individuals. This novel method was further utilised to estimate parasite age and synchronicity status in samples from patients with uncomplicated malaria collected in Accra, Ghana. By coupling the results obtained from the study of the biophysical properties in vitro and parasite ages in vivo it was possible to determine the potential of mechanical and dielectric properties for label-free sorting of P. falciparum-infected and uninfected RBCs

Identification of an expanded population of activated CD4(+) CD25(+) T cells expressing CD45RO and IL-7R in kidney transplant recipients

Recent studies have shown that CD4+ CD25+ T cells belong to two functionally different T lymphocytes, i.e. regulatory T cells (Treg) or activated T cells (Tact), which can be distinguished based on the expression of CD45RO and IL-7R: Treg (FoxP3+) are CD45RO+ IL-7R- , whereas Tact (FoxP3- ) are CD45RO+ IL- 7R+. In order to determine if a CD4+ CD25+ CD45RO+ IL-7R+ activated T cell population might be identified in kidney transplant recipients, we studied 27 healthy subjects (HS) and 23 kidney recipients, of whom 17 had stable graft function under standard immunosuppression (IS), 5 had biopsy-proven chronic humoral rejection (CHR), and one was a stable "tolerant" patient who had discontinued IS for more than 2 years. Phenotypical analysis by flow cytometry and functional assays by MLR were performed. Overall, the Tact population was found to be significantly increased in 87% of the transplant recipients (mean: 18.8±10.1% of CD4+ CD25+ T cells) compared to HS (mean: 4.5±2.0%; P&lt;0.0001). In the 5 patients with CHR, this Tact population was highly expanded (31.3±9.3%; P&lt;0.0001), whereas it was comparable to HS in the "tolerant" recipient (4.7%). Intermediate levels (16.0±6.9%; P&lt;0.0001) were found in the 17 stable recipients. In CHR, the proliferative capacity of the Tact population was found to be 5-fold higher when stimulated by irradiated donor PBMC as compared to a stimulation by irradiated 3rd party PBMC. After kidney transplantation, an expanded circulating CD4+ CD25+ T cell population characterized by the expression of CD45RO and IL-7R was found in most recipients, particularly in those with CHR. In a patient with long-term operational tolerance, this Tact population was similar to HS. Measuring circulating Tact may become a useful monitoring tool after transplantation

HCV infection after liver transplantation is associated with lower levels of alloreactive CD4+CD25+CD45RO+IL-7R+high+ T cells

Aim: Expression of IL-7R discriminates alloreactive CD4 T cells (Foxp3 negative), from IL-7Rlow regulatory CD4 T cells (Foxp3 positive). Chronic hepatitis C virus infection (HCV) reduces expression of IL-7R on T cells thus promoting persistence of infection. The aim of this study was to analyze the effect of HCV infection on the expression of IL-7R of activated CD4+ T cells in liver transplant patients. Patients and methods: We analyzed PBMC from liver transplant recipients for the expression of CD4, CD25, FoxP3, IL-7R (24 HCV negative and 29 HCV-chronically infected). We compared these data with non-transplanted individuals (52 HCV-chronically infected patients and 38 healthy donors). Results: In HCV-infected liver transplant recipients, levels of CD4+CD25+CD45RO+IL-7R+ T cells were significantly reduced (10.5+/-0.9%) when compared to non-HCV-infected liver transplant recipients (17.6+/-1.4%) (P&lt;0.001), while both groups (HCV-infected and negative transplant recipients) had significantly higher levels than healthy individuals (6.6+/-0.9%) (P&lt;0.0001). After successful antiviral therapy (sustained antiviral response), 6 HCV-infected transplant recipients showed an increase of CD4+CD25+CD45RO+IL-7R+ T cells, reaching levels similar to that of non-HCVinfected recipients (10.73+/-2.63% prior therapy versus 21.7+/-6.3% after clearance of HCV). (P&lt;0.05) In 4 non-responders (i.e. HCVRNA remaining present in serum), levels of CD4+CD25+CD45RO+IL-7R+ T cells remained unmodified during and after antiviral treatment (11.8+/- 3.3% versus 11.3+/-3.3% respectively). Conclusions: Overall, these data indicate that CD4+CD25+CD45RO+IL-7R+ T cells appear to be modulated by chronic HCV infection after liver transplantation. Whether lower levels of alloreactive T cells in HCV-infected liver transplant recipients are associated with a tolerogenic profile remains to be studied

Dielectric characterization of Plasmodium falciparum infected red blood cells using microfluidic impedance cytometry

Although malaria is the world’s most life-threatening parasitic disease, there is no clear understanding of how certain biophysical properties of infected cells change during the malaria infection cycle. In this article, we use microfluidic impedance cytometry to measure the dielectric properties of Plasmodium falciparum-infected red blood cells (i-RBCs) at specific time-points during the infection cycle. Individual parasites were identified within i-RBCs using Green Fluorescent Protein (GFP) emission. The dielectric properties of cell sub-populations were determined using the multi-shell model. Analysis showed that the membrane capacitance and cytoplasmic conductivity of i-RBCs increased along the infection time-course, due to membrane alterations caused by parasite infection. The volume ratio occupied by the parasite was estimated to vary from &lt;10% at earlier stages, to ~90% at later stages. This knowledge could be used to develop new label-free cell sorting techniques for sample pre-enrichment, improving diagnosis

Dataset for &quot;Dielectric characterization of Plasmodium falciparum infected red blood cells using microfluidic impedance cytometry&quot; article

The dataset contains the experimental data and Matlab codes needed to generate the figures of the article &#39;Dielectric characterization of Plasmodium falciparum infected red blood cells using microfluidic impedance cytometry&#39; by C. Honrado, L. Ciuffreda, D. Spencer, L. Ranford-Cartwright and H. Morgan in Royal Society Interface.</span