Differential Impact of CD43 and CD28 on T-Cell Differentiation Depending on the Order of Engagement with the TCR.

The combination of signals from the T-cell receptor (TCR) and co-stimulatory molecules triggers transcriptional programs that lead to proliferation, cytokine secretion, and effector functions. We compared the impact of engaging the TCR with CD28 and/or CD43 at different time points relative to TCR engagement on T-cell function. TCR and CD43 simultaneous engagement resulted in higher CD69 and PD-1 expression levels than in TCR and CD28-stimulated cells, with a cytokine signature of mostly effector, inflammatory, and regulatory cytokines, while TCR and CD28-activated cells secreted all categories of cytokines, including stimulatory cytokines. Furthermore, the timing of CD43 engagement relative to TCR ligation, and to a lesser degree that of CD28, resulted in distinct patterns of expression of cytokines, chemokines, and growth factors. Complete cell activation was observed when CD28 or CD43 were engaged simultaneously with or before the TCR, but ligating the TCR before CD43 or CD28 failed to complete a cell activation program regarding cytokine secretion. As the order in which CD43 or CD28 and the TCR were engaged resulted in different combinations of cytokines that shape distinct T-cell immune programs, we analyzed their upstream sequences to assess whether the combinations of cytokines were associated with different sets of regulatory elements. We found that the order in which the TCR and CD28 or CD43 are engaged predicts the recruitment of specific sets of chromatin remodelers and TFSS, which ultimately regulate T-cell polarization and plasticity. Our data underscore that the combination of co-stimulatory molecules and the time when they are engaged relative to the TCR can change the cell differentiation program.

A Systematic Review on Deep Learning with CNNs Applied to Surface Defect Detection.

Surface defect detection with machine learning has become an important tool in industries and a large field of study for researchers or workers in recent years. It is necessary to have a simplified source of information that helps us to better focus on one type of surface. In this systematic review, we present a classification for surface defect detection based on convolutional neural networks (CNNs) focused on surface types. Findings: Out of 253 records identified, 59 primary studies were eligible. Following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines, we analyzed the structures of each study and the concepts related to defects and their types on surfaces. The presented review is mainly focused on finding a classification for the types of surfaces most used in industry (metal, building, ceramic, wood, and special). We delve into the specifics of each surface category, offering illustrative examples of their applications within both industrial and laboratory settings. Furthermore, we propose a new taxonomy of machine learning based on the obtained results and collected information. We summarized the studies and extracted the main characteristics such as type of surface, problem types, timeline, type of network, techniques, and datasets. Among the most relevant results of our analysis, we found that the metallic surface is the most used, as it is the one found in 62.71% of the studies, and the most prevalent problem type is classification, accounting for 49.15% of the total. Furthermore, we observe that transfer learning was employed in 83.05% of the studies, while data augmentation was utilized in 59.32%. Our findings also provide insights into the cameras most frequently employed, along with the strategies adopted to address illumination challenges present in certain articles and the approach to creating datasets for real-world applications. The main results presented in this review allow for a quick and efficient search of information for researchers and professionals interested in improving the results of their defect detection projects. Finally, we analyzed the trends that could open new fields of study for future research in the area of surface defect detection.

Pulmonary embolism in pediatrics: A 10-year experience from a tertiary center in Brazil

ABSTRACT Introduction: Although still rare, pulmonary embolism (PE) in children has been increasing over the years. Data regarding this group of patients are still sparse, which contributes to the lack of standardized prophylaxis protocols and the misdiagnosis. This study aimed to determine the incidence of pediatric PE at a Brazilian tertiary hospital, describe clinical characteristics and identify possible risk factors. We also analyzed the diagnosis and management of PE. Methods: This was a retrospective review of tertiary Brazilian single-center data of all pediatric patients (0 - 18 years) with acute PE, diagnosed radiologically, from September 2009 to May 2019. Results: The incidence of PE was 3.3 cases per 10,000 hospitalized children. All the twenty-three cases had some risk factor identified and sixteen of them (69.5%) had more than one risk factor. The most important were central venous catheter (39.1%), malignancy (34.8%) and recent surgery (34.8%). Among the children with identifiable symptoms (69.5%), the most common was dyspnea (56.2%). Only one patient did not receive antithrombotic therapy because of the high bleeding risk and most patients (70.6%) were treated for 3 to 6 months. Among the nineteen patients alive at the end of the six-month follow-up, ten (52.6%) repeated the PE image control. Seven of them (70.0%) had complete or partial resolution of the thrombosis and none had worsening images. Conclusion: Our lower incidence than that of the current literature may reflect underdiagnosis due to low suspicion of PE. At least one risk factor was identified in all patients, which emphasizes the importance of increasing awareness of high-risk children.

Associations of Body Condition Score at Calving, Parity, and Calving Season on the Performance of Dairy Cows and Their Offspring.

This study aimed to evaluate the impact of body condition score (BCS) at calving, parity, and the calving season on the performance of dairy cows and their offspring. Data from 521 Holstein cows that calved a female calf and had their BCS evaluated at calving from a single commercial farm located in Southern Brazil were used. Cows were categorized into five BCS classes: class 1: <3.0 (n = 19), class 2: 3.0-3.25 (n = 134), class 3: 3.5-3.75 (n = 160), class 4: 4.0-4.25 (n = 142), and class 5: >4.25 (n = 66). Data were also categorized by calving order (primiparous and multiparous dams) and by calving season. The study was designed as a prospective cohort study. Variables with normal distribution were analyzed by the MIXED procedure of SAS, while binary outcomes were analyzed by the GLIMMIX procedure of SAS. Daughters from primiparous dams were born lighter (39.1 ± 0.42 vs. 41.4 ± 0.29 kg, p < 0.01), but they had the same weights as the daughters from multiparous cows at weaning (121.5 ± 1.67 vs. 120.4 ± 1.58 kg, p = 0.20). As expected, primiparous cows showed lower (p < 0.01) 305-day milk yields than multiparous ones: 8633 ± 363 vs. 10,761 ± 249 kg, respectively. Regarding the calving season, cows that calved in the winter were the most productive ones, and those that calved in the fall had lower milk yields (p = 0.01). Calves born in the winter were heavier at birth (p < 0.01), calved younger (p = 0.04), and produced more milk at first lactation (p = 0.03). The BCS class had an impact (p < 0.01) on calf birth weights; daughters from Class 1 cows (BCS < 3.0) were lighter (38.0 ± 1.0 kg) than the calves from Class 5 cows with a BCS > 4.25 (41.9 ± 0.57 kg). Calves from dams with a BCS < 3 (Class 1) had a 31.8% culling rate until weaning, while calves from cows with a BCS of 3.0-3.25 (Class 2) had a 9.6% culling rate (p = 0.12). These results suggest that maternal and environmental factors, such as calving season and parity, in addition to the dams' body condition score at calving, are associated with different offspring performances.

Pulmonary embolism in pediatrics: A 10-year experience from a tertiary center in Brazil.

INTRODUCTION: Although still rare, pulmonary embolism (PE) in children has been increasing over the years. Data regarding this group of patients are still sparse, which contributes to the lack of standardized prophylaxis protocols and the misdiagnosis. This study aimed to determine the incidence of pediatric PE at a Brazilian tertiary hospital, describe clinical characteristics and identify possible risk factors. We also analyzed the diagnosis and management of PE. METHODS: This was a retrospective review of tertiary Brazilian single-center data of all pediatric patients (0 - 18 years) with acute PE, diagnosed radiologically, from September 2009 to May 2019. RESULTS: The incidence of PE was 3.3 cases per 10,000 hospitalized children. All the twenty-three cases had some risk factor identified and sixteen of them (69.5%) had more than one risk factor. The most important were central venous catheter (39.1%), malignancy (34.8%) and recent surgery (34.8%). Among the children with identifiable symptoms (69.5%), the most common was dyspnea (56.2%). Only one patient did not receive antithrombotic therapy because of the high bleeding risk and most patients (70.6%) were treated for 3 to 6 months. Among the nineteen patients alive at the end of the six-month follow-up, ten (52.6%) repeated the PE image control. Seven of them (70.0%) had complete or partial resolution of the thrombosis and none had worsening images. CONCLUSION: Our lower incidence than that of the current literature may reflect underdiagnosis due to low suspicion of PE. At least one risk factor was identified in all patients, which emphasizes the importance of increasing awareness of high-risk children.

A Real-Time Automated Defect Detection System for Ceramic Pieces Manufacturing Process Based on Computer Vision with Deep Learning.

Defect detection is a key element of quality control in today's industries, and the process requires the incorporation of automated methods, including image sensors, to detect any potential defects that may occur during the manufacturing process. While there are various methods that can be used for inspecting surfaces, such as those of metal and building materials, there are only a limited number of techniques that are specifically designed to analyze specialized surfaces, such as ceramics, which can potentially reveal distinctive anomalies or characteristics that require a more precise and focused approach. This article describes a study and proposes an extended solution for defect detection on ceramic pieces within an industrial environment, utilizing a computer vision system with deep learning models. The solution includes an image acquisition process and a labeling platform to create training datasets, as well as an image preprocessing technique, to feed a machine learning algorithm based on convolutional neural networks (CNNs) capable of running in real time within a manufacturing environment. The developed solution was implemented and evaluated at a leading Portuguese company that specializes in the manufacturing of tableware and fine stoneware. The collaboration between the research team and the company resulted in the development of an automated and effective system for detecting defects in ceramic pieces, achieving an accuracy of 98.00% and an F1-Score of 97.29%.

Plant-microbe symbiosis widens the habitability range of the Daisyworld.

Plant-microbe symbiosis is pervasive in the Earth's ecosystems and dates back to the early land colonisation by plants. Mutualistic partnership with rhizobia bacteria and mycorrhizal fungi promotes plant nutrition, growth and diversity, impacting important ecosystem functions. However, how the global behaviour and dynamical properties of an ecosystem are modified by plant-microbe symbiosis is still unclear. To tackle this theoretical question, we resorted to the Daisyworld as a toy model of the global ecosystem. We redesigned the original model to allow accounting for seed production, spreading, germination, and seedling development to mature seed-producing plants to describe how symbiotic and non-symbiotic daisy species differ in these key processes. Using the steady-state and bifurcation analysis of this model, we demonstrate that symbiosis with microbes broadens the habitability range of the Daisyworld by enhancing plant growth and/or facilitating plant access to otherwise uninhabitable nutrient-poor regions.

Illustrated State-of-the-Art Capsules of the ISTH 2022 Congress.

The ISTH London 2022 Congress is the first held (mostly) face-to-face again since the COVID-19 pandemic took the world by surprise in 2020. For 2 years we met virtually, but this year's in-person format will allow the ever-so-important and quintessential creativity and networking to flow again. What a pleasure and joy to be able to see everyone! Importantly, all conference proceedings are also streamed (and available recorded) online for those unable to travel on this occasion. This ensures no one misses out. The 2022 scientific program highlights new developments in hemophilia and its treatment, acquired and other inherited bleeding disorders, thromboinflammation, platelets and coagulation, clot structure and composition, fibrinolysis, vascular biology, venous thromboembolism, women's health, arterial thrombosis, pediatrics, COVID-related thrombosis, vaccine-induced thrombocytopenia with thrombosis, and omics and diagnostics. These areas are elegantly reviewed in this Illustrated Review article. The Illustrated Review is a highlight of the ISTH Congress. The format lends itself very well to explaining the science, and the collection of beautiful graphical summaries of recent developments in the field are stunning and self-explanatory. This clever and effective way to communicate research is revolutionary and different from traditional formats. We hope you enjoy this article and will be inspired by its content to generate new research ideas.

Technical performance of a lateral flow immunoassay for detection of anti-SARS-CoV-2 IgG in the outpatient follow-up of non-severe cases and at different times after vaccination: comparison with enzyme and chemiluminescent immunoassays.

This study assessed the technical performance of a rapid lateral flow immunochromatographic assay (LFIA) for the detection of anti-SARS-CoV-2 IgG and compared LFIA results with chemiluminescent immunoassay (CLIA) results and an in-house enzyme immunoassay (EIA). To this end, a total of 216 whole blood or serum samples from three groups were analyzed: the first group was composed of 68 true negative cases corresponding to blood bank donors, healthy young volunteers, and eight pediatric patients diagnosed with other coronavirus infections. The serum samples from these participants were obtained and stored in a pre-COVID-19 period, thus they were not expected to have COVID-19. In the second group of true positive cases, we chose to replace natural cases of COVID-19 by 96 participants who were expected to have produced anti-SARS-CoV-2 IgG antibodies 30-60 days after the vaccine booster dose. The serum samples were collected on the same day that LFIA were tested either by EIA or CLIA. The third study group was composed of 52 participants (12 adults and 40 children) who did or did not have anti-SARS-CoV-2 IgG antibodies due to specific clinical scenarios. The 12 adults had been vaccinated more than seven months before LFIA testing, and the 40 children had non-severe COVID-19 diagnosed using RT-PCR during the acute phase of infection. They were referred for outpatient follow-up and during this period the serum samples were collected and tested by CLIA and LFIA. All tests were performed by the same healthcare operator and there was no variation of LFIA results when tests were performed on finger prick whole blood or serum samples, so that results were grouped for analysis. LFIA's sensitivity in detecting anti-SARS-CoV-2 IgG antibodies was 90%, specificity 97.6%, efficiency 93%, PPV 98.3%, NPV 86.6%, and likelihood ratio for a positive or a negative result were 37.5 and 0.01 respectively. There was a good agreement (Kappa index of 0.677) between LFIA results and serological (EIA or CLIA) results. In conclusion, LFIA analyzed in this study showed a good technical performance and agreement with reference serological assays (EIA or CLIA), therefore it can be recommended for use in the outpatient follow-up of non-severe cases of COVID-19 and to assess anti-SARS-CoV-2 IgG antibody production induced by vaccination and the antibodies decrease over time. However, LFIAs should be confirmed by using reference serological assays whenever possible.

Acrosomal alkalinization occurs during human sperm capacitation.

Mammalian sperm capacitation is a prerequisite for successful fertilization. Capacitation involves biochemical and physiological modifications of sperm as they travel through the female reproductive tract. These modifications prepare the sperm to undergo the acrosome reaction (AR), an acrosome vesicle exocytosis that is necessary for gamete fusion. Capacitation requires an increase in both intracellular calcium ([Ca2+]i) and pH (pHi). Mouse sperm capacitation is accompanied by acrosomal alkalinization and artificial elevation of the acrosome pH (pHa) is sufficient to trigger the AR in mouse and human sperm, but it is unknown if pHa increases naturally during human sperm capacitation. We used single-cell imaging and image-based flow cytometry to evaluate pHa during capacitation and its regulation. We found that pHa progressively increases during capacitation. The V-ATPase, which immunolocalized to the acrosome and equatorial segment, is mainly responsible for the acidity of the acrosome. It is likely that the regulation of V-ATPase is at least in part responsible for the progressive increase in pHa during capacitation. Acrosome alkalinization was dependent on extracellular HCO3- and Ca2+. Inhibition of the HCO3--dependent adenylyl cyclase and protein kinase A induced significant pHa changes. Overall, alkalinization of the acrosome may be a key step in the path toward the AR.

Differences in children and adolescents with SARS-CoV-2 infection: a cohort study in a Brazilian tertiary referral hospital.

OBJECTIVES: To compare demographic/clinical/laboratory/treatments and outcomes among children and adolescents with laboratory-confirmed coronavirus disease 2019 (COVID-19). METHODS: This was a cross-sectional study that included patients diagnosed with pediatric COVID-19 (aged <18 years) between April 11, 2020 and April 22, 2021. During this period, 102/5,951 (1.7%) of all admissions occurred in neonates, children, and adolescents. Furthermore, 3,962 severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) detection samples were processed in patients aged <18 years, and laboratory-confirmed COVID-19 occurred in 155 (4%) inpatients and outpatients. Six/155 pediatric patients were excluded from the study. Therefore, the final group included 149 children and adolescents (n=97 inpatients and 52 outpatients) with positive SARS-CoV-2 results. RESULTS: The frequencies of sore throat, anosmia, dysgeusia, headache, myalgia, nausea, lymphopenia, pre-existing chronic conditions, immunosuppressive conditions, and autoimmune diseases were significantly reduced in children and adolescents (p<0.05). Likewise, the frequencies of enoxaparin use (p=0.037), current immunosuppressant use (p=0.008), vasoactive agents (p=0.045), arterial hypotension (p<0.001), and shock (p=0.024) were significantly lower in children than in adolescents. Logistic regression analysis showed that adolescents with laboratory-confirmed COVID-19 had increased odds ratios (ORs) for sore throat (OR 13.054; 95% confidence interval [CI] 2.750-61.977; p=0.001), nausea (OR 8.875; 95% CI 1.660-47.446; p=0.011), and lymphopenia (OR 3.575; 95% CI 1.355-9.430; p=0.010), but also had less hospitalizations (OR 0.355; 95% CI 0.138-0.916; p=0.032). The additional logistic regression analysis on patients with preexisting chronic conditions (n=108) showed that death as an outcome was significantly associated with pediatric severe acute respiratory syndrome (SARS) (OR 22.300; 95% CI 2.341-212.421; p=0.007) and multisystem inflammatory syndrome in children (MIS-C) (OR 11.261; 95% CI 1.189-106. 581; p=0.035). CONCLUSIONS: Half of the laboratory-confirmed COVID-19 cases occurred in adolescents. Individuals belonging to this age group had an acute systemic involvement of SARS-CoV-2 infection. Pediatric SARS and MIS-C were the most important factors associated with the mortality rate in pediatric chronic conditions with COVID-19.

Obesity as a Thrombogenic and Cardiovascular Risk Factor in Children.

BACKGROUND/AIMS: Obesity leads to increased risk of thromboembolic events in adults, but few studies have addressed the relationship between obesity and thrombogenic risk during childhood. The aim of this study was to evaluate the prothrombotic state of obese children in comparison with healthy children. METHODS: Thrombin generation, fibrinogen, and D-dimer levels, along with metabolic parameters, were measured in 72 prepubertal children, of which 47 were obese and 25 eutrophic. RESULTS: A significant increase in thrombin generation, fibrinogen, and dyslipidemia was found among obese patients. CONCLUSION: A prothrombotic state develops in childhood obesity during the prepubertal phase.

Prevalence and outcomes of thrombotic and hemorrhagic complications in pediatric acute promyelocytic leukemia in a tertiary Brazilian center

Abstract Introduction: Little attention is given to thrombosis associated with pediatric acute promyelocytic leukemia (APL). This study describes the thrombotic and hemorrhagic manifestations of APL in pediatric patients and evaluates their hemostasis, based on coagulation tests. Methods: Inclusion criteria were age 0-18 years and APL diagnosis between April 2005 and November 2017. Patients who had received blood transfusion prior to coagulation tests were excluded. Baseline coagulation tests, hematologic counts, and hemorrhagic/thrombotic manifestations were evaluated. Results: Median age was 10.7 years (1-15 years). The initial coagulation tests revealed a median Hgb of 8.3 g/dL (4.7-12.9 g/dL), median leucocyte count of 10.9 × 109/L (1.1-95.8 × 109/L), median platelet count of 31.8 × 109/L (2.0-109.0 × 109/L), median activated partial thromboplastin time (aPTT) of 31.7 s (23.0-50.4 s), median aPTT ratio of 1.0 (0.78-1.6), median thromboplastin time (PT) of 17.5 s (13.8-27.7 s), median PT activity of 62% (25-95 %), and median fibrinogen of 157.7 mg/dL (60.0-281.0 mg/dL). Three patients (13%) had thrombosis. At diagnosis, 21 patients (91.3%) had bruising, one patient (4.3%) had splenic vein and artery thrombosis and one patient (4.3%) presented without thrombohemorrhagic manifestations. During treatment, two patients (8.6%) had thrombosis. Conclusion: Knowledge of thrombosis in pediatric APL is important to determine its risk factors and the best way to treat and prevent this complication.

Discrete Dynamic Model of the Mammalian Sperm Acrosome Reaction: The Influence of Acrosomal pH and Physiological Heterogeneity.

The acrosome reaction (AR) is an exocytotic process essential for mammalian fertilization. It involves diverse physiological changes (biochemical, biophysical, and morphological) that culminate in the release of the acrosomal content to the extracellular medium as well as a reorganization of the plasma membrane (PM) that allows sperm to interact and fuse with the egg. In spite of many efforts, there are still important pending questions regarding the molecular mechanism regulating the AR. Particularly, the contribution of acrosomal alkalinization to AR triggering physiological conditions is not well understood. Also, the dependence of the proportion of sperm capable of undergoing AR on the physiological heterogeneity within a sperm population has not been studied. Here, we present a discrete mathematical model for the human sperm AR based on the physiological interactions among some of the main components of this complex exocytotic process. We show that this model can qualitatively reproduce diverse experimental results, and that it can be used to analyze how acrosomal pH (pH a ) and cell heterogeneity regulate AR. Our results confirm that a pH a increase can on its own trigger AR in a subpopulation of sperm, and furthermore, it indicates that this is a necessary step to trigger acrosomal exocytosis through progesterone, a known natural inducer of AR. Most importantly, we show that the proportion of sperm undergoing AR is directly related to the detailed structure of the population physiological heterogeneity.

Thromboprophylaxis after kidney transplantation in children: Ten-year experience of a single Brazilian center.

BACKGROUND: Kidney transplantation is the gold standard treatment for children with end-stage chronic kidney disease. Graft thrombosis is an important cause of graft failure, with high morbidity, mortality, and impact on quality of life and to the health system. The role of thromboprophylaxis in this setting is still uncertain. We describe the demographic characteristics and thrombotic risk factors in pediatric renal transplant recipients, determining the rate of renal graft thrombosis, and discuss the role of thromboprophylaxis. METHODS: This retrospective study reviewed 96 pediatric renal transplantations between 2008 and 2017 in a single hospital. Patients were assigned to one of two groups: children who did not receive thromboprophylaxis after transplantation and those who did. We reported their characteristics, comparing the incidence of graft thrombosis and hemorrhagic complications between the groups. RESULTS: Forty-nine patients (51%) received thromboprophylaxis. Thrombosis occurred in 5 patients who did not receive thromboprophylaxis (5.2%) compared with none in the group that did (p = .025). In all patients, renal graft thrombosis resulted in early graft loss. Thirteen patients had hemorrhagic complications. Seven were unrelated to pharmacological thromboprophylaxis (2 major, 1 moderate, and 4 minor bleeding, which either did not receive thromboprophylaxis or had bleeding prior to thromboprophylaxis), while six occurred during heparinization (2 major, 1 moderate, and 3 minor bleeding). There was no significant difference in the rate of hemorrhagic complications between the groups (p = .105). CONCLUSIONS: The rate of renal graft thrombosis was 5.2%. Thrombosis remains an important cause of early graft loss. Thromboprophylaxis was associated with a reduction in graft thrombosis without increased risk of bleeding.

A first-takes-all model of centriole copy number control based on cartwheel elongation.

How cells control the numbers of subcellular components is a fundamental question in biology. Given that biosynthetic processes are fundamentally stochastic it is utterly puzzling that some structures display no copy number variation within a cell population. Centriole biogenesis, with each centriole being duplicated once and only once per cell cycle, stands out due to its remarkable fidelity. This is a highly controlled process, which depends on low-abundance rate-limiting factors. How can exactly one centriole copy be produced given the variation in the concentration of these key factors? Hitherto, tentative explanations of this control evoked lateral inhibition- or phase separation-like mechanisms emerging from the dynamics of these rate-limiting factors but how strict centriole number is regulated remains unsolved. Here, a novel solution to centriole copy number control is proposed based on the assembly of a centriolar scaffold, the cartwheel. We assume that cartwheel building blocks accumulate around the mother centriole at supercritical concentrations, sufficient to assemble one or more cartwheels. Our key postulate is that once the first cartwheel is formed it continues to elongate by stacking the intermediate building blocks that would otherwise form supernumerary cartwheels. Using stochastic models and simulations, we show that this mechanism may ensure formation of one and only one cartwheel robustly over a wide range of parameter values. By comparison to alternative models, we conclude that the distinctive signatures of this novel mechanism are an increasing assembly time with cartwheel numbers and the translation of stochasticity in building block concentrations into variation in cartwheel numbers or length.

Plk4 triggers autonomous de novo centriole biogenesis and maturation.

Centrioles form centrosomes and cilia. In most proliferating cells, centrioles assemble through canonical duplication, which is spatially, temporally, and numerically regulated by the cell cycle and the presence of mature centrioles. However, in certain cell types, centrioles assemble de novo, yet by poorly understood mechanisms. Herein, we established a controlled system to investigate de novo centriole biogenesis, using Drosophila melanogaster egg explants overexpressing Polo-like kinase 4 (Plk4), a trigger for centriole biogenesis. We show that at a high Plk4 concentration, centrioles form de novo, mature, and duplicate, independently of cell cycle progression and of the presence of other centrioles. Plk4 concentration determines the temporal onset of centriole assembly. Moreover, our results suggest that distinct biochemical kinetics regulate de novo and canonical biogenesis. Finally, we investigated which other factors modulate de novo centriole assembly and found that proteins of the pericentriolar material (PCM), and in particular γ-tubulin, promote biogenesis, likely by locally concentrating critical components.

Prevalence and outcomes of thrombotic and hemorrhagic complications in pediatric acute promyelocytic leukemia in a tertiary Brazilian center.

INTRODUCTION: Little attention is given to thrombosis associated with pediatric acute promyelocytic leukemia (APL). This study describes the thrombotic and hemorrhagic manifestations of APL in pediatric patients and evaluates their hemostasis, based on coagulation tests. METHODS: Inclusion criteria were age 0-18 years and APL diagnosis between April 2005 and November 2017. Patients who had received blood transfusion prior to coagulation tests were excluded. Baseline coagulation tests, hematologic counts, and hemorrhagic/thrombotic manifestations were evaluated. RESULTS: Median age was 10.7 years (1-15 years). The initial coagulation tests revealed a median Hgb of 8.3 g/dL (4.7-12.9 g/dL), median leucocyte count of 10.9 × 109/L (1.1-95.8 × 109/L), median platelet count of 31.8 × 109/L (2.0-109.0 × 109/L), median activated partial thromboplastin time (aPTT) of 31.7 s (23.0-50.4 s), median aPTT ratio of 1.0 (0.78-1.6), median thromboplastin time (PT) of 17.5 s (13.8-27.7 s), median PT activity of 62% (25-95 %), and median fibrinogen of 157.7 mg/dL (60.0-281.0 mg/dL). Three patients (13%) had thrombosis. At diagnosis, 21 patients (91.3%) had bruising, one patient (4.3%) had splenic vein and artery thrombosis and one patient (4.3%) presented without thrombohemorrhagic manifestations. During treatment, two patients (8.6%) had thrombosis. CONCLUSION: Knowledge of thrombosis in pediatric APL is important to determine its risk factors and the best way to treat and prevent this complication.

Persistent symptoms and decreased health-related quality of life after symptomatic pediatric COVID-19: A prospective study in a Latin American tertiary hospital

OBJECTIVES: To prospectively evaluate demographic, anthropometric and health-related quality of life (HRQoL) in pediatric patients with laboratory-confirmed coronavirus disease 2019 (COVID-19) METHODS: This was a longitudinal observational study of surviving pediatric post-COVID-19 patients (n=53) and pediatric subjects without laboratory-confirmed COVID-19 included as controls (n=52) was performed. RESULTS: The median duration between COVID-19 diagnosis (n=53) and follow-up was 4.4 months (0.8-10.7). Twenty-three of 53 (43%) patients reported at least one persistent symptom at the longitudinal follow-up visit and 12/53 (23%) had long COVID-19, with at least one symptom lasting for >12 weeks. The most frequently reported symptoms at the longitudinal follow-up visit were headache (19%), severe recurrent headache (9%), tiredness (9%), dyspnea (8%), and concentration difficulty (4%). At the longitudinal follow-up visit, the frequencies of anemia (11% versus 0%, p=0.030), lymphopenia (42% versus 18%, p=0.020), C-reactive protein level of >30 mg/L (35% versus 0%, p=0.0001), and D-dimer level of >1000 ng/mL (43% versus 6%, p=0.0004) significantly reduced compared with baseline values. Chest X-ray abnormalities (11% versus 2%, p=0.178) and cardiac alterations on echocardiogram (33% versus 22%, p=0.462) were similar at both visits. Comparison of characteristic data between patients with COVID-19 at the longitudinal follow-up visit and controls showed similar age (p=0.962), proportion of male sex (p=0.907), ethnicity (p=0.566), family minimum monthly wage (p=0.664), body mass index (p=0.601), and pediatric pre-existing chronic conditions (p=1.000). The Pediatric Quality of Live Inventory 4.0 scores, median physical score (69 [0-100] versus 81 [34-100], p=0.012), and school score (60 [15-100] versus 70 [15-95], p=0.028) were significantly lower in pediatric patients with COVID-19 at the longitudinal follow-up visit than in controls. CONCLUSIONS: Pediatric patients with COVID-19 showed a longitudinal impact on HRQoL parameters, particularly in physical/school domains, reinforcing the need for a prospective multidisciplinary approach for these patients. These data highlight the importance of closer monitoring of children and adolescents by the clinical team after COVID-19.