A brain-enriched circular RNA controls excitatory neurotransmission and restricts sensitivity to aversive stimuli.

Circular RNAs (circRNAs) are a large class of noncoding RNAs. Despite the identification of thousands of circular transcripts, the biological significance of most of them remains unexplored, partly because of the lack of effective methods for generating loss-of-function animal models. In this study, we focused on circTulp4, an abundant circRNA derived from the Tulp4 gene that is enriched in the brain and synaptic compartments. By creating a circTulp4-deficient mouse model, in which we mutated the splice acceptor site responsible for generating circTulp4 without affecting the linear mRNA or protein levels, we were able to conduct a comprehensive phenotypic analysis. Our results demonstrate that circTulp4 is critical in regulating neuronal and brain physiology, modulating the strength of excitatory neurotransmission and sensitivity to aversive stimuli. This study provides evidence that circRNAs can regulate biologically relevant functions in neurons, with modulatory effects at multiple levels of the phenotype, establishing a proof of principle for the regulatory role of circRNAs in neural processes.

Recurrent pattern completion drives the neocortical representation of sensory inference.

When sensory information is incomplete or ambiguous, the brain relies on prior expectations to infer perceptual objects. Despite the centrality of this process to perception, the neural mechanism of sensory inference is not known. Illusory contours (ICs) are key tools to study sensory inference because they contain edges or objects that are implied only by their spatial context. Using cellular resolution, mesoscale two-photon calcium imaging and multi-Neuropixels recordings in the mouse visual cortex, we identified a sparse subset of neurons in the primary visual cortex (V1) and higher visual areas that respond emergently to ICs. We found that these highly selective 'IC-encoders' mediate the neural representation of IC inference. Strikingly, selective activation of these neurons using two-photon holographic optogenetics was sufficient to recreate IC representation in the rest of the V1 network, in the absence of any visual stimulus. This outlines a model in which primary sensory cortex facilitates sensory inference by selectively strengthening input patterns that match prior expectations through local, recurrent circuitry. Our data thus suggest a clear computational purpose for recurrence in the generation of holistic percepts under sensory ambiguity. More generally, selective reinforcement of top-down predictions by pattern-completing recurrent circuits in lower sensory cortices may constitute a key step in sensory inference.

Probing inter-areal computations with a cellular resolution two-photon holographic mesoscope.

Brain computation depends on intricately connected yet highly distributed neural networks. Due to the absence of the requisite technologies, causally testing fundamental hypotheses on the nature of inter-areal processing have remained largely out-of-each. Here we developed the first two photon holographic mesoscope, a system capable of simultaneously reading and writing neural activity patterns with single cell resolution across large regions of the brain. We demonstrate the precise photo-activation of spatial and temporal sequences of neurons in one brain area while reading out the downstream effect in several other regions. Investigators can use this new platform to understand feed-forward and feed-back processing in distributed neural circuits with single cell precision for the first time.

Coeliac disease in the COVID-19 pandemic: does HLA have a protective effect?

BACKGROUND: The coronavirus disease 2019 (COVID-19), an acute respiratory disease caused by a novel coronavirus (SARS-CoV-2), is emerging as a worldwide public health emergency. Several scientific contributions reported the potential relevance of human leukocyte antigen (HLA) polymorphism and susceptibility to viruses, such as SARS-CoV. In our study, we examined a population of coeliac subjects presenting the HLA haplotype DQ2 and/or DQ8. Our aim was to evaluate whether HLA DQ2 and/or DQ8 haplotype play a role in SARS-CoV-2-infection. The aim was also to evaluate the difficulty in following the gluten-free diet due to all the adversities produced by the pandemic, such as the food supply disruption, and the difficulties in managing the clinical follow-up. METHODS: 191 consecutive coeliac patients completed a questionnaire on their current clinical status, psychological effects, and management of the gluten-free diet experienced during the COVID-19 pandemic and questions regarding possible SARS-CoV-2 infection. RESULTS: Out of the 191 patients who participated in the study, 42 were full-blown coeliac and 149 were in remission. From the answers provided, 84.8% of patients declared that they no longer consider themselves vulnerable to COVID-19 as they suffer from coeliac disease; 94.2% of patients did not encounter any difficulties in managing the gluten-free diet or in acquiring specific foods and 64.9% of patients in our study underwent diagnostic testing for SARS-CoV-2. Out of this number, 31.5% did so due to contacts with subjects affected by COVID-19, 26.6% for work related reasons, 11.3% due to flu-like symptoms and 30.6% for other reasons. Only 5.8% of the enrolled patients received a diagnosis of COVID-19. Out of all the patients in our population who were diagnosed with COVID-19, 94.8% developed no symptoms and none of them needed hospitalization or intensive care. CONCLUSION: The hypothesis that the HLADQ2 and/or DQ8 haplotype plays a protective role against SARS-CoV-2 infection, as against other viral infections, is intriguingly suggestive.KEY MESSAGESCOVID-19 as a public health emergency;SARS-CoV-2 and possible complications in coeliac disease;Role of HLA DQ2 and/or DQ8 in SARS-CoV-2 infection.

High-performance microbial opsins for spatially and temporally precise perturbations of large neuronal networks.

The biophysical properties of existing optogenetic tools constrain the scale, speed, and fidelity of precise optogenetic control. Here, we use structure-guided mutagenesis to engineer opsins that exhibit very high potency while retaining fast kinetics. These new opsins enable large-scale, temporally and spatially precise control of population neural activity. We extensively benchmark these new opsins against existing optogenetic tools and provide a detailed biophysical characterization of a diverse family of opsins under two-photon illumination. This establishes a resource for matching the optimal opsin to the goals and constraints of patterned optogenetics experiments. Finally, by combining these new opsins with optimized procedures for holographic photostimulation, we demonstrate the simultaneous coactivation of several hundred spatially defined neurons with a single hologram and nearly double that number by temporally interleaving holograms at fast rates. These newly engineered opsins substantially extend the capabilities of patterned illumination optogenetic paradigms for addressing neural circuits and behavior.

Cholinergic modulation of dentate gyrus processing through dynamic reconfiguration of inhibitory circuits.

The dentate gyrus (DG) of the hippocampus plays a key role in memory formation, and it is known to be modulated by septal projections. By performing electrophysiology and optogenetics, we evaluated the role of cholinergic modulation in the processing of afferent inputs in the DG. We show that mature granule cells (GCs), but not adult-born immature neurons, have increased responses to afferent perforant path stimuli upon cholinergic modulation. This is due to a highly precise reconfiguration of inhibitory circuits, differentially affecting Parvalbumin and Somatostatin interneurons, resulting in a nicotinic-dependent perisomatic disinhibition of GCs. This circuit reorganization provides a mechanism by which mature GCs could escape the strong inhibition they receive, creating a window of opportunity for plasticity. Indeed, coincident activation of perforant path inputs with optogenetic release of acetylcholine produces a long-term potentiated response in GCs, essential for memory formation.

Light Modulates Important Pathogenic Determinants and Virulence in ESKAPE Pathogens Acinetobacter baumannii, Pseudomonas aeruginosa, and Staphylococcus aureus.

Light sensing has been extensively characterized in the human pathogen Acinetobacter baumannii at environmental temperatures. However, the influence of light on the physiology and pathogenicity of human bacterial pathogens at temperatures found in warm-blooded hosts is still poorly understand. In this work, we show that Staphylococcus aureus, Acinetobacter baumannii, and Pseudomonas aeruginosa (ESKAPE) priority pathogens, which have been recognized by the WHO and the CDC as critical, can also sense and respond to light at temperatures found in human hosts. Most interestingly, in these pathogens, light modulates important pathogenicity determinants as well as virulence in an epithelial infection model, which could have implications in human infections. In fact, we found that alpha-toxin-dependent hemolysis, motility, and growth under iron-deprived conditions are modulated by light in S. aureus Light also regulates persistence, metabolism, and the ability to kill competitors in some of these microorganisms. Finally, light exerts a profound effect on the virulence of these pathogens in an epithelial infection model, although the response is not the same in the different species; virulence was enhanced by light in A. baumannii and S. aureus, while in A. nosocomialis and P. aeruginosa it was reduced. Neither the BlsA photoreceptor nor the type VI secretion system (T6SS) is involved in virulence modulation by light in A. baumannii Overall, this fundamental knowledge highlights the potential use of light to control pathogen virulence, either directly or by manipulating the light regulatory switch toward the lowest virulence/persistence configuration.IMPORTANCE Pathogenic bacteria are microorganisms capable of producing disease. Dangerous bacterial pathogens, such as Staphylococcus aureus, Pseudomonas aeruginosa, and Acinetobacter baumannii, are responsible for serious intrahospital and community infections in humans. Therapeutics is often complicated due to resistance to multiple antibiotics, rendering them ineffective. In this work, we show that these pathogens sense natural light and respond to it by modulating aspects related to their ability to cause disease; in the presence of light, some of them become more aggressive, while others show an opposite response. Overall, we provide new understanding on the behavior of these pathogens, which could contribute to the control of infections caused by them. Since the response is distributed in diverse pathogens, this notion could prove a general concept.

Involvement of MAF/SPP1 axis in the development of bone marrow fibrosis in PMF patients.

Primary myelofibrosis (PMF) is a myeloproliferative neoplasm characterized by hyperplastic megakaryopoiesis and myelofibrosis. We recently described the upregulation of MAF (v-maf avian musculoaponeurotic fibrosarcoma oncogene homolog) in PMF CD34+ hematopoietic progenitor cells (HPCs) compared to healthy donor. Here we demonstrated that MAF is also upregulated in PMF compared with the essential thrombocytemia (ET) and polycytemia vera (PV) HPCs. MAF overexpression and knockdown experiments shed some light into the role of MAF in PMF pathogenesis, by demonstrating that MAF favors the megakaryocyte and monocyte/macrophage commitment of HPCs and leads to the increased expression of proinflammatory and profibrotic mediators. Among them, we focused our further studies on SPP1 and LGALS3. We assessed SPP1 and LGALS3 protein levels in 115 PMF, 47 ET and 24 PV patients plasma samples and we found that SPP1 plasma levels are significantly higher in PMF compared with ET and PV patients. Furthermore, in vitro assays demonstrated that SPP1 promotes fibroblasts and mesenchymal stromal cells proliferation and collagen production. Strikingly, clinical correlation analyses uncovered that higher SPP1 plasma levels in PMF patients correlate with a more severe fibrosis degree and a shorter overall survival. Collectively our data unveil that MAF overexpression contributes to PMF pathogenesis by driving the deranged production of the profibrotic mediator SPP1.

A clinical-molecular prognostic model to predict survival in patients with post polycythemia vera and post essential thrombocythemia myelofibrosis.

Polycythemia vera (PV) and essential thrombocythemia (ET) are myeloproliferative neoplasms with variable risk of evolution into post-PV and post-ET myelofibrosis, from now on referred to as secondary myelofibrosis (SMF). No specific tools have been defined for risk stratification in SMF. To develop a prognostic model for predicting survival, we studied 685 JAK2, CALR, and MPL annotated patients with SMF. Median survival of the whole cohort was 9.3 years (95% CI: 8-not reached-NR-). Through penalized Cox regressions we identified negative predictors of survival and according to beta risk coefficients we assigned 2 points to hemoglobin level <11 g/dl, to circulating blasts ⩾3%, and to CALR-unmutated genotype, 1 point to platelet count <150 × 109/l and to constitutional symptoms, and 0.15 points to any year of age. Myelofibrosis Secondary to PV and ET-Prognostic Model (MYSEC-PM) allocated SMF patients into four risk categories with different survival (P<0.0001): low (median survival NR; 133 patients), intermediate-1 (9.3 years, 95% CI: 8.1-NR; 245 patients), intermediate-2 (4.4 years, 95% CI: 3.2-7.9; 126 patients), and high risk (2 years, 95% CI: 1.7-3.9; 75 patients). Finally, we found that the MYSEC-PM represents the most appropriate tool for SMF decision-making to be used in clinical and trial settings.

Exchange-bias phenomenon: the role of the ferromagnetic spin structure.

The exchange bias of antiferromagnetic-ferromagnetic (AFM-FM) bilayers is found to be strongly dependent on the ferromagnetic spin configuration. The widely accepted inverse proportionality of the exchange bias field with the ferromagnetic thickness is broken in FM layers thinner than the FM correlation length. Moreover, an anomalous thermal dependence of both exchange bias field and coercivity is also found. A model based on springlike domain walls parallel to the AFM-FM interface quantitatively accounts for the experimental results and, in particular, for the deviation from the inverse proportionality law. These results reveal the active role the ferromagnetic spin structure plays in AFM-FM hybrids which leads to a new paradigm of the exchange bias phenomenon.

[Food sources and average intake of calcium in a representative sample of Spanish schoolchildren]. / Ingesta y fuentes de calcio en una muestra representativa de escolares españoles.

INTRODUCTION: There is controversy about the adequacy of calcium intake to that recommended in Spanish schoolchildren. Some studies indicate that the intake is inadequate in a variable percentage of children, while others insist on the danger of an excessive intake in a huge percentage of this population. AIM: To assess calcium intake and food sources of this nutrient in a representative sample of Spanish children and to judge the adequacy of its contribution to the coverage of recommended intakes. METHODS: 903 schoolchildren (7 to 11 years) from 10 Spanish provinces (Tarragona, Caceres, Burgos, Guadalajara, Valencia, Salamanca, Cordoba, Vizcaya, Lugo and Madrid) were studied. They constituted a representative sample of the Spanish schoolchildren population. The energy and nutrient intake was determined using a "Food record questionnaire" for 3 days, including a Sunday. Calcium intake was compared with the recommended intakes (RI) for the mineral. Weight and height were recorded and body mass index (BMI) calculated. RESULTS: In the studied group (55.3% girls and 44.7% of children), 30.7% had an excess body weight (23.3% overweight and 7.4% obesity). Calcium intake was 859.9 ± 249.2 mg / day (79.5% of the recommendations). 76.7% of children had intakes below 100% of those recommended and 40.1% below of 67% of RI. The ratios calcium/phosphorus (0.74 ± 0.21) and calcium/protein (10.1 ± 2.8) and the index of nutritional quality for calcium (0.78 ± 0.29) were lower than recommended in 91.6%, 99.8% and 81.1% of children, respectively. Dietary calcium came from dairy products (64.7%), dietetic products and infant formulae (7.6%), cereals (7.3%), vegetables (3.5%), fruits (3.4%), pre-cooked meals (3.3%), meats (2.8%), fishes (2.8%) and pulses (2.2%), with no differences by gender. CONCLUSION: Calcium intake was lower than recommended in 76.7% of the children and 40.1% had insufficient intake (< 67% of RI). Having in mind that the main calcium source was dairy products (64.7%), increase consumption of this food group is recommended, especially in the 37.1% of children who did not reach the 2 recommended servings per day.

Influence of temperature management on neurocognitive function in biological aortic valve replacement. A prospective randomized trial.

AIM: Aim of this study was to elucidate if postoperative neurocognitive function after biological aortic valve replacement (AVR) can be influenced by temperature management during cardiopulmonary bypass (CPB). METHODS: In this prospective randomized study, we measured the effect of mild hypothermic (32 °C, N.=30) vs. normothermic (37 °C, N.=30) CPB on neurocognitive function. All patients underwent elective isolated biological AVR (mean age 67 ± 8 years, mean additional EuroSCORE 5.6 ± 2.4). Neurocognitive function was objectively measured by means of objective P300 auditory-evoked potentials before surgery, one week and four months after surgery. Clinical data and outcome were monitored. RESULTS: P300 evoked potentials were comparable between patients operated with mild hypothermic (370 ± 30 ms) and normothermic CPB (373 ± 32 ms) before surgery (P=0.85). P300 peak latencies were prolonged (=impaired) in patients operated with normothermic (402 ± 29, P<0.0001) as well as with mild hypothermic CPB (405 ± 30 ms, P<0.0001) one week after surgery. Even four months after surgery, still impairment of P300 peak latencies could be documented in either patients operated with normothermic (394 ± 28 ms) and mild hypothermic CPB (400 ± 33 ms,) in repeated measures analysis of variance (P=0.042). Group comparison revealed no difference between patients operated with normothermic and mild hypothermic CPB at one week (P=0.54) and four months (P=0.67) after surgery. Clinical data as well as postoperative adverse events were comparable between the two groups. CONCLUSION: Normothermic temperature management during CPB is non-inferior to hypothermic in means of neuroprotection. Since patients after biological aortic valve replacement show a subclinical but measurable cognitive deficit up to four months after surgery, other factors have to be addressed to add further benefit to the extremely good results of open biological AVR.

Genetic association of HLA-DQB1 and HLA-DRB1 polymorphisms with alopecia areata in the Italian population.

BACKGROUND: Alopecia areata (AA) is a multifactorial disease characterized by hair loss especially from the scalp. As for other autoimmune conditions, the major histocompatibility complex (HLA) region is associated with AA susceptibility. OBJECTIVE: To provide evidence for the association of specific HLA-DQB1 and HLA-DRB1 alleles with AA in an Italian population, using a case-control approach. METHODS: We performed a case-control study to investigate whether HLA-DQB1 and -DRB1 alleles predispose to AA in the Italian population. HLA class II typing was performed in 85 patients with AA and 210 healthy controls from the same ethnic group. RESULTS: An increased frequency of DQB1*03, coding for DQ7 heterodimers, and a decreased rate of the DQB1*06 allele were observed in patients when compared with controls; the greatest and significant difference was in the group of cases with a more severe phenotype [AA>50% patients (more than 50% hair loss) vs. controls, P=4·5×10(-3) , P(c)=0·031, odds ratio (OR) 2·01, 95% confidence interval (CI) 1·22-3·31 and P=2·5×10(-3) , P(c)=0·017, OR 0·22, 95% CI 0·07-0·72, respectively]. DQB1*03, serologically related to DQ8 or coding for DQ9 molecules, was not associated with AA susceptibility. Out of all patients, 65·9% carried DQ7 heterodimers compared with 49·5% of the controls (P=7·3×10(-3) , OR 1·97, 95% CI 1·17-3·32) and DQ7 prevalence rose to 76·3% in patients with AA>50% (P=1·7×10(-3) , OR 3·28, 95% CI 1·48-7·27). No significant difference was found in the distribution of DRB1 variants or phenotypes among cases and controls. CONCLUSION: Our data show a correlation between the HLA-DQB1 locus and the occurrence of AA in Italy supporting DQB1*03(DQ7) as a predisposing allele for the disease and the relevance of the HLA genetic test in the clinical management of AA.

Validation of cardiac output measurement with the LiDCO™ pulse contour system in patients with impaired left ventricular function after cardiac surgery.

After cardiac surgery, patients with low left ventricular ejection fraction probably benefit the most from accurate monitoring of continuous cardiac output. Thirty patients with impaired ventricular function were studied, and intermittent bolus thermodilution and continuous pulse contour (LiDCO plus™) cardiac output compared. Following lithium dilution calibration, a total of 220 paired results were recorded. Thermodilution and LiDCO measurements ranged from 2.3 to 11.0 and 2.6 to 10.8 l.min(-1), respectively. Corresponding means (SD) were 6.1 (1.6) and 6.2 (1.9) l.min(-1), with coefficients of variance of 26 and 31%, respectively. The correlation coefficient was 0.82, bias 0.28 l.min(-1) with upper and lower limits of agreement 1.96 and -1.41 l.min(-1); the percentage error was 27%. LiDCO showed good correlation, marginal bias and acceptable limits of agreement and percentage error. It could therefore potentially replace thermodilution as a means of measuring cardiac output in the ICU, particularly when determination of pulmonary artery pressure is not required.

Effect of different air/steam convection cooking methods on turkey breast meat: physical characterization, water status and sensory properties.

Turkey breast samples were cooked using a forced convection oven at three relative humidity levels (RH=8, 35 and 88%) at 100°C. Cooking parameters (temperature, cook value, and yield), textural and sensory properties as well as water status of the samples were evaluated. The application of different RH levels resulted in different cooking performances and cooked meat quality. Low steam cooking conditions (RH=35%) significantly increased cooking yield (7% higher than the high steam cooking), moisture content and water-holding capacity and had a positive effect on perceived tenderness, as shown by sensory analysis, where steam cooked samples were perceived as the most tender. The more mobile protons of (1)H T(2) (relaxing at times longer than 1s) in low steam samples were related to the higher perceived tenderness. Low steam cooking allowed for less water consumption, making this process an attractive cooking method as compared to high steam, as it also resulted in higher quality cooked turkey meat.

Effects of highly active antiretroviral therapy on vaccine-induced humoral immunity in HIV-infected adults.

OBJECTIVES: The acquisition of adequate vaccine-induced humoral immunity is especially important in HIV-infected individuals, who are at increased risk of infections. The aim of the study was to assess the safety of administering a complete vaccination programme to successfully treated HIV-infected adults and to evaluate specific humoral responses and the effect of highly active antiretroviral therapy (HAART) interruption on these responses. METHODS: A placebo-controlled, double-blind clinical trial was designed and 26 HIV-infected adults enrolled. Study participants were randomized to receive either a complete immunization schedule with commercial vaccines or placebo for 12 months. HAART was then discontinued for 6 months. Specific humoral responses were evaluated at baseline, at month 12 and after HAART interruption and compared between groups. RESULTS: There were neither local nor systemic secondary effects related to vaccination. Specific humoral responses to vaccines were adequate, but a loss of immunoglobulin G titres was observed after HAART interruption in 12 study participants. CONCLUSIONS: HAART interruption may cause impairment of previously acquired vaccine-induced immunity in HIV-infected adults.

Relationship between A-line Autoregressive Index, Spectral Entropy and steady state predicted site-effect effective concentrations at 05-50-95 of propofol at different clinical endpoints.

AIM: Target controlled infusion intravenous anesthesia is a growing phenomenon. Nowadays, many anesthesiologists feel the need to monitor depth of anesthesia during total intravenous anesthesia, even though it is not a standard technique worldwide. Spectral Entropy (SE) is a relatively new depth of anesthesia index. The aim of this study was to investigate whether predicted site-effect propofol concentrations, A-line Autoregressive Index (AAI) and SE values are useful for predicting loss of verbal contact (LVC) and loss of consciousness (LOC) during steady-state conditions. METHODS: Forty-four patients scheduled for elective major abdominal surgery were recruited. All patients were unpremedicated. A target controlled infusion of propofol was administered using Schnider's pharmacokinetic model. The initial propofol infusion provided a site-effect concentration of 1.0 mcg mL-1, and was increased stepwise by 1.0 mcg mL-1 every 4 minutes until the concentration reached 6.0 mcg mL-1. A 4 minute interval was chosen to assure that steady state site-effect concentrations were obtained. AAI, SE and propofol site-effect concentrations were recorded when LVC occurred and also when LOC occurred. Population values for predicted site-effect concentrations at the clinical endpoints were estimated and correlated with AAI and SE values. RESULTS: In our study for LOC the effect-site concentration to include 90% of patients was 5.85 ?mcg mL-1 (5.70-5.90) and 3.4 mcg mL-1 (3.24-3.60) for LVC. In this study, 90% of patients lost verbal contact at an AAI value of 68 (64.6-71.4) and an SE value of 68.2 (66.2-70.2). LOC occurred in 90% of patients at an AAI value of 39.2 (37.2-41.1) and an SE value of 40.2 (38.1-41.3). CONCLUSIONS: LOC and LVC occur within a defined range of predicted site-effect concentrations. More emphasis should be given to site-effect concentrations. SE and AAI have similar values at different endpoints and similar correlation with Ceprop. AAI and SE are both useful tools in predicting both LVC and LOC.