The impact of National Containment Measures on a Pediatric Italian regional Hub for COVID-19, an observational study

Background Numerous studies described the epidemiological link and main clinical features of pediatric COVID-19, during the first pandemic period. Our study encompasses several different phases since the National Lockdown in Italy. The primary outcome is (I) to analyze the prevalence of positive NST (Nasopharyngeal Swab Test) among the largest Italian Pediatric cohort admitted to a single regional PED Hub for COVID-19 during an eight-month period. Secondary outcomes are: (II) the description of trend of admissions in our PED and (III) the categorization of the positive patients according to clinical manifestations and epidemiological link. Methods We described 316 patients with a positive NST for SARS-CoV2, on a total of 5001 nasopharyngeal swabs performed among 13,171 admissions at our PED, over a period starting from March 17th, 2020 to December 1st, 2020. Age, epidemiological link, clinical features and hospitalizations were analyzed according to different lockdown phases. Data were collected anonymously from electronic records and analyzed using SPSS 22.00 statistics software (Chicago, IL). Results Thirty-six percent of total admissions have been tested. During the post lockdown period, we performed the highest percentage of NST (Nasopharyngeal Swab Test) 49.7%, and among them 7.9% were positive. The prevalence of infection during a 10-month period was 2.3%. Mean age was 6.5 years old. Familial Link accounted for the 67.7% of infection, while Extrafamilial and Unknown link accounted for 17 and 14.9%, respectively. Familial link is predominant during all phases. Seventeen patients showed an intra-scholastic link, and the highest prevalence was observed in the 7–10 years age group, with a prevalence of 12.8% (5 patients). Fever was the most frequent symptom (66%), in particular among preschooler children aged 0–6 years (71.9%). Older children were more frequently symptomatic. Seven patients were admitted with MIS-C diagnosis. Conclusions Different levels of containment measures caused important changes in number of positive NST for SARS-CoV2. Familial link was predominant in our cohort, during all phases of Lockdown. The risk of being infected at home is four time greater than the risk of being infected from an extra familial individual. Further studies are needed to evaluate the clear impact of intra-scholastic link. The constant improvement in knowledge on onset symptoms and risk factor for SARS-CoV2 infection and its complications (e.g. MIS-C), can impact on number of hospitalizations, ICU admissions and early management.

Endothelial Cdk5 deficit leads to the development of spontaneous epilepsy through CXCL1/CXCR2-mediated reactive astrogliosis

Blood–brain barrier (BBB) dysfunction has been suggested to play an important role in epilepsy. However, the mechanism mediating the transition from cerebrovascular damage to epilepsy remains unknown. Here, we report that endothelial cyclin-dependent kinase 5 (CDK5) is a central regulator of neuronal excitability. Endothelial-specific Cdk5 knockout led to spontaneous seizures in mice. Knockout mice showed increased endothelial chemokine (C-X-C motif) ligand 1 (Cxcl1) expression, decreased astrocytic glutamate reuptake through the glutamate transporter 1 (GLT1), and increased glutamate synaptic function. Ceftriaxone restored astrocytic GLT1 function and inhibited seizures in endothelial Cdk5-deficient mice, and these effects were also reversed after silencing Cxcl1 in endothelial cells and its receptor chemokine (C-X-C motif) receptor 2 (Cxcr2) in astrocytes, respectively, in the CA1 by AAV transfection. These results reveal a previously unknown link between cerebrovascular factors and epileptogenesis and provide a rationale for targeting endothelial signaling as a potential treatment for epilepsy.

Estimation and testing for panel data partially linear single-index models with errors correlated in space and time

We consider a panel data partially linear single-index models (PDPLSIM) with errors correlated in space and time. A serially correlated error structure is adopted for the correlation in time. We propose using a semiparametric minimum average variance estimation (SMAVE) to obtain estimators for both the parameters and unknown link function. We not only establish an asymptotically normal distribution for the estimators of the parameters in the single index and the linear component of the model, but also obtain an asymptotically normal distribution for the nonparametric local linear estimator of the unknown link function. Then, a fitting of spatial and time-wise correlation structures is investigated. Based on the estimators, we propose a generalized F-type test method to deal with testing problems of index parameters of PDPLSIM with errors correlated in space and time. It is shown that under the null hypothesis, the proposed test statistic follows asymptotically a [Formula: see text]-distribution with the scale constant and degrees of freedom being independent of nuisance parameters or functions. Simulated studies and real data examples have been used to illustrate our proposed methodology.

FIERY1 promotes microRNA accumulation by suppressing rRNA-derived small interfering RNAs in Arabidopsis

Plant microRNAs (miRNAs) associate with ARGONAUTE1 (AGO1) to direct post-transcriptional gene silencing and regulate numerous biological processes. Although AGO1 predominantly binds miRNAs in vivo, it also associates with endogenous small interfering RNAs (siRNAs). It is unclear whether the miRNA/siRNA balance affects miRNA activities. Here we report that FIERY1 (FRY1), which is involved in 5′−3′ RNA degradation, regulates miRNA abundance and function by suppressing the biogenesis of ribosomal RNA-derived siRNAs (risiRNAs). In mutants of FRY1 and the nuclear 5′−3′ exonuclease genes XRN2 and XRN3, we find that a large number of 21-nt risiRNAs are generated through an endogenous siRNA biogenesis pathway. The production of risiRNAs correlates with pre-rRNA processing defects in these mutants. We also show that these risiRNAs are loaded into AGO1, causing reduced loading of miRNAs. This study reveals a previously unknown link between rRNA processing and miRNA accumulation.