The detection and identification of single nucleotide polymorphism (SNP) is an important basis for the evaluation of individual medicine and the judgement of disease susceptibility. At present, SNP genotyping technology includes the Sanger sequencing, TaqMan probe quantitative polymerase chain reaction (qPCR), amplification-refractory mutation system (ARMS)-PCR, Kompetitive allele specific PCR (KASP), and next-generation sequencing (NGS), etc. However, there are some disadvantages such as high cost of development and detection, long detection period and easily occurring false-positive results to these technologies. Focusing on these limitations, we proposed a new SNP detection method named as universal probe-based intermediate primer-triggered qPCR (UPIP-qPCR). In this method, only two types of fluorescence-labeled probes were used for all SNP genotyping, thus, greatly reducing the cost of development and detection for SNP genotyping. In the amplification process, unlabeled intermediate primers with template specific recognition function were able to trigger probe hydrolysis and specific signal release. The sensitivity of UPIP-qPCR in SNP genotyping was 0.01 ng, the call rate was more than 99.1%, and the accuracy was more than 99.9%. This novel technology gave rise to the low cost and high accuracy of SNP genotyping, and provided a new and reliable SNP genotyping method for the development of precision medicine.

The literature describes multiple approaches for the repair of stenosed branch pulmonary arteries. Regardless of the technique, restenosis is undesirably and notoriously common. We describe a case of severe left pulmonary artery stenosis repaired with a novel technique in consideration of factors leading to restenosis. The native main pulmonary artery was transected and turned down to create a direct anastomosis with the left pulmonary artery. The child had a normal sized main pulmonary artery with tricuspid atresia and pulmonary atresia with ductus arteriosus feeding the severely stenosed left pulmonary artery. Our novel technique resulted in hemodynamically gratifying results with a tension free tissue-tissue anastomosis with potential for growth.

Background: Vernal keratoconjunctivitis (VKC) is a rare chronic conjunctivitis characterized by a predominantly eosinophil-mediated inflammatory disorder that could develop critical complications such as blindness. Oxidative stress plays a pivotal role in the pathogenesis of several allergic diseases. The role of oxidative stress has been hypothesized in VKC, but no study explored this issue.Furthermore, cyclosporine A (CsA) exerts an anti-inflammatory and antioxidant action on the conjunctiva. This study aims to assess oxidative stress in VKC patients and controls and to study the effect ofCsA on oxidative stress in these subjects. Methods:Thirty-six consecutive children, including 12 VKC(9 males, 75%; mean age 10,17; SD ± 2.48) patients without treatment,12 VKC treated with CsA(9 males, 75%; mean age 9,08; SD± 2.75) and 12 controls (CT) (7males,58%; mean age8,58; SD ±1,78) were recruited. A cross-sectional study was performed to compare H2O2 in the serum and the tears ofthese children. Results: Compared with CT and VKC children treated with CsA, VKCuntreated children had significantly higher values ofHydrogen peroxide (H2O2) in theserum and the tears.No significant differences were observed between CT and VKC treated with CsA. A significant correlation was found at the linear regression analysis between serum and tear H2O2 levels. Conclusion: This study provides the first report attesting that patients with VKC have high oxidative stress; furthermore, it suggests that CsA could have an anti-inflammatory and antioxidant action that could be useful to prevent the poor VKC outcome.

Congenital left atrial appendage aneurysm is an extremely rare anomaly. It is seen at any time ranging from fetal to ninth decade of life. Patients with left atrial appendage aneurysm may be asymptomatic, or present with dyspnea, arrhythmias, thromboembolic phenomenon. We report a case of prenatal diagnosis at 26 weeks of gestation , postnatal management and outcome of left atrial appendage aneurysm.

By analysing the evolution of the COVID-19 epidemic in the state of Minas Gerais, Brazil, we showed the importance of considering the sub-notification not only of deaths but also of infected cases. It was shown that the largely used criteria of a historical all-deaths baseline is not approachable in this case, where most of the deaths are associated with causes that should decrease due to social distancing and reduction of economic activities. A quite simple and intuitive model based on the Gompertz function was applied to estimate excess deaths and excess of infected cases. It fits well the data and predicts the evolution of the epidemic adequately. Based on these analyses, an excess of 21.638 deaths and 557.216 infected cases is predicted until the end of 2020, with an upper bound of the case fatality rate of around 2.4 % and a prevalence of 2.6 %. The geographical distribution of cases and deaths and its ethnic correlation are also presented. This study points out the necessity of governmental and private organizations working together to improve public awareness and stimulate social distancing to curb the viral infection, especially in critical places with high poverty.

A Kalman reduced form is obtained for linear systems over Hermite rings. This reduced form gives information of the set of assignable polynomials to a given linear system.

A better understanding of the innate and adaptive cells in the COVID-19 disease caused by the SARS-CoV-2 coronavirus is a necessity for the development of effective treatment methods and vaccines. We studied phenotypic features of innate and adaptive immune cells, oxidative burst, phagocytosis and apoptosis. One hundred and three patients with COVID-19 grouped according to their clinical features as mild (35%), moderate (40.8%), and severe (24.3%) were included in the study. Monocytes from all COVID-19 patients were CD16+ pro-inflammatory monocytes. Neutrophils were mature and functional. No defect has been found in ROS production of monocytes and neutrophils as well as no defect in their apoptosis. As bridging cells of the innate and adaptive immune system; the percentage of NK cells was in normal range whereas the percentages of CD3-CD8+CD56+ innate lymphoid and CD3+CD56+ NK like T cells were found to be high in the severe cases of COVID-19. Although absolute numbers of all lymphocyte subsets were low and showed a tendency for a gradual decrease in accord with the disease progression, in all COVID-19 patients, the lymphocyte subset with the most decreased absolute number was B lymphocytes, followed by CD4 + T cells in the severe cases. The percentages of regulatory, CD3+CD4-CD8-; HLA-DR+CD3+ and CD28-CD8+ cells were found to be significantly increased. Importantly, we demonstrated spontaneous caspase-3 activation and increased lymphocyte apoptosis. Altogether our data suggest that SARS-CoV- 2 primarily affects lymphocytes not innate cells. So that, it may interrupt the cross-talk between adaptive and innate immune systems.

Aortic atresia is uncommonly associated with atrioventricular and ventriculoarterial discordance.(1) Presence of severe regurgitation of Ebsteinoid malformation of the tricuspid valve in this subset results in reduced aortic blood flow in-utero. The hemodynamic explanation of this anomaly was reported by Celermajer and colleagues.(2) We report here a term neonate with this anomaly detect antenatally.

Introduction: Right ventricular (RV) pacing causes changes in the heart’s electrical and mechanical activation patterns. QRS duration is a useful surrogate marker of electrical dyssynchrony; longer QRS duration during RV pacing indicates poor prognosis. However, the mechanisms underlying longer QRS duration during RV pacing remain unclear; hence, we investigated factors predicting QRS prolongation during RV pacing. Methods and Results: We enrolled 211 patients who underwent catheter ablation for supraventricular tachyarrhythmia and showed no bundle-branch-block. Three-dimensional mapping for QRS duration during RV pacing from the RV outflow to RV apex was performed, and the difference in QRS duration was analyzed. The predisposing factors causing QRS >160 ms during RV apical pacing were also analyzed. QRS durations at baseline and during RV pacing from the RV outflow and at RV apex were 85.0±7.5 ms, 163.7±17.1 ms, and 156.2±16.1 ms, respectively. With respect to QRS duration, there was a significant correlation between RV outflow and RV apical pacing (r=0.658, p<0.001). The difference in QRS duration between RV outflow and apex in each patient was only 12.5±10.4 ms. Logistic multivariable regression analysis identified baseline QRS duration [odds ratio (OR) 1.24, 95% confidence interval (CI) 1.15 to 1.33, p<0.01], interventricular septum thickness (OR 1.20, 95% CI 1.02-1.40, p=0.025), left atrial diameter (OR 1.08, 95% CI 1.01-1.16, p=0.024), and E/e’ (OR 1.23, 95% CI 1.12-1.35, p<0.01) as significant predictors of prolonged QRS duration during RV apical pacing. Conclusion: QRS duration during RV pacing largely depends not on the pacing site, but on underlying structural heart diseases.

Introduction：Combing CA and LAAO into one procedure has become a prospective measurement for patients with nonvalvular atrial fibrillation. Data on the incidence of DRT in one-stop intervention, treatment strategy, and its clinical implications are limited. Methods：A meta-analysis of observational studies evaluating the incidence, treatment strategy, and clinical implications of DRT was conducted. Results：Overall 21 studies describing DRT events and one case were included in the study. The pooled incidence of DRT in one-stop intervention was 1.2% (range from 0% to 7.3%, 95%CI 0.7%-1.8%, I2=0). 56.25% of events were diagnosed in the first three months after the procedure. All cases were diagnosed with a trans-esophagus echocardiogram (TEE). All patients diagnosed with DRT were prescribed anticoagulants. And 63% (12/19) events were reported with complete thrombus resolution. Anticoagulation duration varied greatly from 30d to 6m. Unknown clinical events were reported relating to DRT. Conclusions：DRT is an uncommon complication of the one-stop intervention. It occurs mainly in the first three months after the procedure. Anticoagulation seems to be an appropriate method for dissolving thrombus.

Long-term application of high nitrogen and phosphorus fertilizer and mono-tillage practices can adversely affect soil health, carbon sequestration and crop growth. A 10-year field experiment was conducted in a wheat-maize cropping system on the Loess Plateau in China to explore fertilization and tillage methods that improve SOC sequestration and crop yields. We evaluated the effects of (1) fertilization (balanced fertilization (BF), low fertilization (LF), and conventional fertilization (CF)) and (2) alternating years of different tillage (no-tillage and subsoiling (NS), subsoiling and ploughing (SP), ploughing and no-tillage (PN)) or continuous ploughing tillage (PP) on input-C, SOC pool, and crop yields. BF and rotational tillage (NS, SP, and PN) increased the amount and stabilization rate of input-C, thereby increased SOC storage, and the highest effect was found in BF+NS treatment. Simultaneously, BF produced higher contents of SOC, readily oxidizable carbon (ROC), particulate organic carbon (POC) and dissolved organic carbon (DOC) and C pool management index (CMI) at 0-10 cm depth. For tillage, rotational tillage increased labile C contents and CMI at 0-10 cm, 20-35 cm and 35-50 cm depths, which improved soil quality. Crop yields showed an increase tendency with the increases of SOC content, labile C fraction contents, and CMI. Therefore, the higher yields of wheat and maize were found in BF and rotational tillage; the highest were in BF+NS treatment. Our finding suggested that NS combined with BF may be the best management to increase SOC storage, improve soil quality and productivity on China’s Loess Plateau.

We describe a novel surgical technique of 31 patients with histopathologically–confirmed placenta accreta spectrum (PAS) disorders managed by a multidisciplinary team using prophylactic infrarenal abdominal aortic cross-clamping technique during cesarean hysterectomy. We conclude that this new surgical procedure is a safe and effective technique to reduce operative blood loss. Hopefully, our pioneer work will stimulate others to develop protocols assessing this innovative technique to improve surgical outcome of PAS disorders.

Background SARS-CoV-2 is a novel coronavirus described for the first time in China in December 2019. This virus can cause a disease that ranges in spectrum from asymptomatic to severe respiratory disease with multiorgan failure, and the most severe cases are associated with some comorbidities and patient age. However, there are patients who do not have those risk factors who still develop serious disease. Methods In this study, we identified the presence of other respiratory viruses in positive cases of COVID-19 in Mexico to determine if any coinfections were correlated with more severe manifestations of COVID-19. We analysed 103 confirmed cases of COVID-19 using RT-qPCR for the detection of 16 other respiratory viruses. Results Of the cases analysed, 14 (13.6%) were cases of coinfection, and 92% of them never required hospitalization, even when comorbidities and advanced age were involved. There weren’t significant differences between the presence of comorbidities and the mean ages of the groups Conclusions These results suggest that coinfection is not related to more severe COVID-19 and that, depending on the virus involved, it could even lead to a better prognosis. We believe that our findings may lay the groundwork for new studies aimed at determining the biological mechanism by which this phenomenon occurs and for proposing corresponding strategies to limit the progression to severe cases of COVID-19.

IFITM family proteins have broad-spectrum antiviral capabilities. Preliminary studies in our laboratory have preliminarily proved that IFITMs have the effect of inhibiting influenza viruses. In order to further study its mechanism and role in the occurrence and development of influenza, relevant studies have been carried out. Fluorescence quantitative PCR detection, yeast two-hybrid test and optical confocal microscopy were used to investigate the effect of hIFITM3 on influenza virus replication, the interaction with hABHD16A and the expression of inflammation-related factors. In HEK293 cells, overexpression of hIFITM3 protein significantly inhibited the replication of influenza virus at 24h, 48h, and 72h; yeast two-hybrid experiment proved that IFITM3 interacts with ABHD16A; laser confocal microscopy observations showed that IFITM3 and ABHD16A co-localized in Cell membrane area; the expression level of inflammation-related factors in cells overexpressing hIFITM3 or hABHD16A was detected by fluorescence quantitative PCR, and the results showed that the mRNA levels of IL-1β, IL-6, IL-10, TNF-a and COX2 were significantly increased . But when IFITM3/ABHD16A was co-expressed, the mRNA expression levels of these cytokines were significantly reduced except for COX2. When influenza virus infected cells co-expressing IFITM3/ABHD16A, the expression level of inflammatory factors decreased compared with the control group, indicating that IFITM3 can play an important role in regulating inflammation balance. This study confirmed that hIFITM3 has an effect of inhibiting influenza virus replication. Furthermore, it was found that hIFITM3 interacts with hABHD16A, following which it can better inhibit the replication of influenza virus and the inflammatory response caused by the disease process.

Background: Central venous catheters (CVCs) are the main cause of venous thromboembolism (VTE) in critically ill children. The optimal first-line treatment for children with asymptomatic CVC-related VTE is unknown. Due to a paucity of clinical trials, clinical practice guidelines can offer only weak recommendations for the management of asymptomatic CVC- related VTE. Method: This case-based survey was designed to assess current trends in local management strategies for pediatric patients with an asymptomatic CVC- related thrombosis. The survey focused on the use of the thrombophilia testing, management approach, duration of anticoagulation, and the use of secondary prophylaxis. We hypothesize that there will be significant variation in these four management areas, in large part due to the aforementioned paucity of available data.REDCap® questions were sent to members of the Saudi Arabian Pediatric Hematology/Oncology Society (SAPHOS) clinical forum/email database. We used a hypothetical case scenario to assess management strategies for asymptomatic CVC-related VTE and secondary prophylaxis. Results: Seventy-one (30%) physicians responded to the survey. The majority of the respondents (83.3%) did not use thrombophilia testing. The far majority (95%) treated with anticoagulation. In contrast, the survey respondents varied widely in the duration of anticoagulation and the use of secondary prophylaxis. Conclusions: Asymptomatic CVC-related VTE is a common clinical entity with limited data guiding management. In Saudi Arabia, there remains considerable variability in clinical management. These findings will help identify crucial knowledge gaps in the management of asymptomatic CVC-related VTE and facilitate clinical trials that will help establish evidence-based treatment guidelines

There is no question that developing new medications in children is fraught with challenges, particularly for rare conditions including pediatric venous thromboembolism (VTE). This is due to both logistical and ethical considerations which are nicely described in a document on the Food & Drug Administration (FDA) website.[1] Furthermore, gaining an approval from the FDA for pediatric use requires a functional partnership between pharmaceutical companies (Pharma), academia, and the regulators/officers at the FDA. When this relationship works well, novel agents can be made available to children that have the assurance of efficacy and safety which is in the best interest of all involved parties, especially patients. The licensure of emicizumab for the prevention of bleeding in hemophilia A patients is one excellent example in which a serious unmet need for a rare disease was addressed in a timely manner (~18 months from the start of a phase 3 trial to approval), and where the labelled indication even includes the word “newborn” with respect to the included age groups. [2,3]Unfortunately, this is not the case with respect to anticoagulants in children, and there is plenty of blame to go around including Pharma, academia (myself included), but also the FDA. I know this all too well as I have had a front seat view having served as an advisor to the FDA on this very topic in 2011 as well as on several other occasions involving specific discussions regarding fondaparinux and rivaroxaban. Although the authors and investigators of this report [4] are to be commended for the significant effort it took to achieve an FDA-approved indication, one can’t help but feel that with respect at least to injectable anticoagulants that “the ship has sailed.” What do I mean by this? Enoxaparin is the most commonly used low molecular weight heparin (LMWH) and anticoagulant in children with fondaparinux also gaining more use with the prime advantage being that it is a once-a-day option. Despite dalteparin (a less commonly used LMWH) now being licensed for children [5], I doubt it will ever supersede enoxaparin in prescriptions nor does it have the advantages of fondaparinux, particularly once daily dosing.How did we arrive at such an unenviable situation? Certainly, it is nobody’s fault that enoxaparin does not have a pediatric indication—the author’s clearly explained the fact that enoxaparin came to the market prior to the Pediatric Research Equity Act (PREA), and at this point, despite the sheer volume of data on the pediatric use of enoxaparin, it will likely never be licensed for children. This is not the case, however, for fondaparinux which has been in regulatory limbo with respect to pediatric use for nearly 15 years. This, despite the fact that there is more published data on fondaparinux than dalteparin including a similarly (to dalteparin) designed, prospective, dose-finding, pharmacokinetic, efficacy and safety study [6-8], and the fact that the Pharma companies (the compound has changed hands a few times) have been in discussions with the FDA repeatedly. Unlike with dalteparin, the FDA has placed numerous and pointless hurdles upon the responsible Pharma for capricious reasons succeeding only in potentially putting children at increased risk of harm by, for example, requiring a dose-finding study when the dose of fondaparinux is already well-established. This is the antithesis of what the FDA should be doing. This unending process of which I have played a significant part as an academician has been nothing short of befuddling. While the FDA clearly went to great lengths to work with the sponsor to have dalteparin approved for children, they owe the pediatric hematology community an explanation on what has gone so wrong with fondaparinux.So, where does this leave us currently and what would I recommend pediatric hematologists do with the data from this report [4] and the licensure of dalteparin for children? Importantly, off-label use in the pediatric setting is quite common typically ranging around 50% depending on the setting [9] so there is no need for any pediatric treater to fret over prescribing anticoagulants as such. Thus, if you are comfortable using enoxaparin or fondaparinux based on the available data, the collective pediatric experience and your personal experience, then I would advocate that you continue to do so until there are better options (more on that later). If, however, you prefer to prescribe medications per the prescribing information (to the extent possible) and you find the data from this study compelling, then certainly you may choose dalteparin as your anticoagulant of choice for your pediatric patients with VTE.Above I discussed the current situation, however on a strongly positive note, there has been outstanding cooperation between Pharma, academicians and the FDA when it comes to the development of the direct oral anticoagulants (DOACs) which without a doubt will dramatically change the management of pediatric VTE. While I have been privy to discussions with the FDA regarding rivaroxaban and have served on the steering committee for the rivaroxaban and edoxaban studies, I am also aware of the productive discussions with respect to dabigatran and apixaban. This trilateral collaboration is the epitome of what PREA is for, and in the coming year or two, it is highly likely that several DOACs will be licensed for use in children and will also lead to the availability of pediatric-friendly formulations.In conclusion, the approval of dalteparin is on the one hand far too little and too late to be of any meaningful clinical use, yet it does set an example of what fruitful pediatric drug development can look like in hematology/oncology (and other specialties as well) particularly for rare diseases. It is incumbent upon the academic community not to request, but in fact to demand that Pharma fund proper studies (not just ones that “check the box”), and that the FDA review data in a fair and reasonable manner such that the future will be filled with more examples like dalteparin and fewer debacles like fondaparinux.Referenceshttps://www.fda.gov/drugs/drug-information-consumers/drug-research-and-children [Accessed September 9, 2020]Young G, Liesner R, Chang , Sidonio R, Oldenburg J, Jimenez-Yuste V, Mahlangu J, Kruse-Jarres R, Wang M, Uguen M, Doral MY, Wright LY, Schmitt C, Levy GG, Shima M, Mancuso ME. A multicenter, open-label, phase 3 study of emicizumab prophylaxis in children with hemophilia A with inhibitors. Blood 2019; 134: 2127-2138.https://www.accessdata.fda.gov/drugsatfda_docs/label/2017/761083s000lbl.pdf [Accessed September 9, 2020]Merino M, Richardson N, Reaman G, Ande A, Zvada S, Liu C, Hariharan S, De Claro A, Farrell A, Pazdur R. FDA approval summary: Dalteparin for the treatment of venous thromboembolism in pediatric patients. Pediatr Blood Cancer 2020 (in press).https://www.accessdata.fda.gov/drugsatfda_docs/label/2019/020287s072lbl.pdf [Accessed September 9, 2020]Young G, Yee DL, O’Brien SH, Khanna R, Barbour A, Nugent DJ. FondaKIDS: A prospective pharmacokinetic and safety study of fondaparinux in children between 1 and 18 years of age. Pediatr Blood Cancer 2011; 57: 1049-1054.Ko RH, Michieli C, Lira JL, Young G. FondaKIDS II: Long-term follow-up data of children receiving fondaparinux for treatment of venous thromboembolic events. Thromb Res 2014; 134: 643-647.Shen X, Wile R, Young G. FondaKIDS III: A long-term retrospective cohort study of fondaparinux for treatment of venous thromboembolism in children. Pediatr Blood Cancer 2020; 67:e28295.Yackey K, Stukus K, Cohen D, Kline D, Zhao S, Stanley R. Off-label prescribing practices in pediatrics: An update. Hosp Pediatr 2019; 9:186-193.

The production of purified virus particles with high quality and quantity for vaccine preparation requires scalable purification procedure in downstream step. A purification scheme based on combined strong anion-exchange and size exclusion chromatography (2D -AEC×SEC) is developed for production non-structural protein (NSP) free foot and mouth diseases (FMD) vaccine and the whole procedure is accomplished with 78 % recovery, 85 % virus yield and more than 90 % of residual DNA (rDNA) is removed from the purified vaccine. Due to use AEC as the first column, the injection volume increases four times compare to previous report. Alternatively, a mathematical modeling and simulation approach based on plate model chromatography are developed and matched with the experimental chromatography data to obtain better perception in predicting retention behavior and saving time in downstream scale-up method development. The analysis of purified virus particles by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE), dynamic light scattering (DLS) high performance size exclusion chromatography (HP-SEC), matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS), transmission electron microscopy (TEM) and biological test provide to the best quality of purified FMD virus.

We studied the psychosocial impact of the start of the COVID-19 pandemic on Dutch children with cancer in outpatient care and their caregivers (n=799) using regular monitoring and screening outcomes. No differences were observed between the pre-COVID-19 and COVID-19 era in health-related quality of life and fatigue of children. Fewer caregivers were distressed during the COVID-19 era than pre-COVID-19. In conclusion, the additional stress of COVID-19 did not deteriorate psychosocial functioning of children with cancer and their caregivers. Results may be explained by alleviating daily life changes, experience in coping with medical traumatic stress and appropriate care and support.

Individuals and populations time annual events such as migration and reproduction to match favorable times in their environment. Physiological preparations for reproduction rely on predictive cues such as day length to accurately time reproduction. In birds, preparation typically begins with light reception by the hypothalamus, which initiates multiple central and peripheral responses. We studied two closely related populations of a songbird, the dark-eyed junco, that live in a common winter environment but diverge in their timing of reproduction as spring approaches. One population is resident and initiates reproduction earlier than the other, which migrates northward prior to reproducing. We caught resident and migrant juncos from the field during early spring and collected hypothalamic and pituitary tissues. We used isobaric tandem mass tag (TMT) labeling to identify differentially expressed proteins (DEPs) as possible regulators of the seasonal divergence in reproductive timing. We found 3038 unique proteins expressed in the hypothalamus and pituitary proteome, among which we identified 75 DEPs. These were associated with hormones, neurotransmitter secretion, transport, neuropeptide synthesis, prohormone synthesis, neurogenesis, GnRH synthesis, release and stability, food intake, locomotion, and social behavior. Some of these proteins were associated with early breeding in resident juncos, and others were associated with increased food intake, fat metabolism, locomotor activity and phenology in migratory juncos. Our results provide new insight into the neuroendocrine regulation of the timing of reproduction and migration. This study provides the first evidence of a relationship between functional protein variation in the neuroendocrine tissues and seasonal divergence in reproductive timing.

Improving synchrony in young infant supported by noninvasive ventilation for severe bronchiolitis: Yes we can… so we should!C Milési, MD1, J Baleine, MD1, G Cambonie, MD, PhD11Department of Neonatal Medicine and Pediatric Intensive Care, Arnaud de Villeneuve Hospital, Montpellier University Hospital Center, Montpellier, FranceCorrespondence: Christophe Milési, MD, Department of Neonatal Medicine and Pediatric Intensive Care Unit, Arnaud de Villeneuve Hospital, Montpellier University Hospital, 371 Avenue du Doyen Gaston Giraud, 34295 Montpellier Cedex 5, FranceTel: +33 467 336 556, Fax: +33 467 336 228, e-mail:c-milesi@chu-montpellier.frWord count: 1391; references: 43Keywords: asynchrony, bronchiolitis, noninvasive ventilation, neurally adjusted ventilatory assist, infantAdmission to a pediatric intensive care unit (PICU) is required for 9-14% of infants with acute viral bronchiolitis (AVB) and evolving respiratory distress.1,2 In this context, AVB generally presents as severe obstructive lung disease, which causes an increased load on the respiratory muscles.3,4 As no pharmaceutical treatment currently in use is able to rapidly reduce airway obstruction, the management of these patients is focused on providing respiratory support to reduce respiratory muscle fatigue and prevent intubation. Noninvasive ventilation (NIV), delivered by continuous positive airway pressure (CPAP) or bilevel positive airway pressure (BiPAP), has traditionally been applied and is associated with reductions in intubation rates, ventilation-associated complications, and duration and cost of hospitalization.5,6 More recently, a third device was introduced to administer a heated and humidified mixture of air and oxygen with high-flow nasal cannulae (HFNC). PICU clinicians thus currently have at their disposal several respiratory assistance modalities for infants with moderate to severe AVB, but few high-grade evidence studies to guide their choice.7 Indeed, most of the studies carried out in this field have been observational, with comparisons with historical cohorts,5,6,8-10 or physiological, assessing differences with and without noninvasive respiratory support.4,11-13 In this issue of Pediatric Pulmonology , Delacroix et al. re-evaluates the use of BiPAP as the first-line respiratory support in less-than-6-months patients with bronchiolitis.14 In their single-center retrospective study, they report longer durations of noninvasive support and longer PICU stays in the patients supported with BiPAP compared with CPAP and HFNC. The authors should be congratulated for this analysis covering more than 250 infants, one of the largest cohorts treated with this device. This work usefully complements the information provided by two recent observational studies that focused on the comparison of these three techniques in this specific group of patients.15,16 The inherent limitation of these retrospective studies, whether monocentric14,16 or database-driven,15 is the presence of confounders, which influence both the choice of the initial respiratory support and the outcome. It was particularly interesting to note in Delacroix et al.’s study that the clinicians’ preferred choice was BiPAP, although no local written protocol required it in this situation. However, the BiPAP-treated group also included a higher rate of premature infants, a condition associated with the immaturity of immune defenses and airway development and ventilation-induced airway injury that predisposes to more severe bronchiolitis.17Several national and multinational surveys have demonstrated that pediatric intensivists currently select HFNC for initial respiratory care in cases of severe bronchiolitis.18,19 This popularity among caregivers appears to be associated with the perception of a technique that is easy to implement, with comparable effectiveness and fewer complications than CPAP.20 The physiological background for using CPAP in this instance is that the application of nearly constant pressure support is associated with rapid unloading of respiratory muscles, increased expiratory time, and concomitantly improved respiratory distress.4,11,21 Reduced respiratory effort and a change in breathing pattern suggest that CPAP improves the work of breathing by offsetting the patient’s inspiratory effort to overcome intrinsic end-expiratory pressure (PEEPi). In addition, positive airway pressure helps maintain airway patency and alleviate bronchiolar obstruction, a ‘stenting’ effect that in turn reduces respiratory system resistance. HFNC also generates some degree of airway distenting pressure, which supports inspiratory effort. The reduced diaphragmatic electrical activity and decreased esophageal pressure swings also confirm the effectiveness of HFNC to reduce the work of breathing in AVB.12,13 Randomized controlled trials, however, have found that neither CPAP nor HFNC reduces the need for intubation in infants with bronchiolitis, probably due to the current low occurrence of this event1,2,21-24 In practice, CPAP and HFNC are introduced early in the course of the disease—even as a preemptive measure in some cases—in infants generally not exhausted. While NIV is widely used to treat bronchiolitis,25 most clinicians, unlike in Delacroix et al.’s study,14 consider BiPAP the next step for patients failing with HFNC or CPAP.19 Failure rates vary widely, from 10% to 50% in the major randomized controlled studies,1,2,22-24and depend on multiple factors, the most important probably related to the criteria and delays in defining failure. According to the TRAMONTANE study, the main causes of failure are worsening respiratory distress, especially in patients supported by HFNC; patient discomfort, the leading cause in patients treated with CPAP; and the occurrence of apnea in a minority of cases in both groups.22 The very large cohort of almost 6500 patients collected by Clayton et al.15 in more than 90 PICUs in North America and Saudi Arabia gives credit to clinicians who turn to NIV in the event of failure, since this strategy seems to avoid escalation to invasive mechanical ventilation (IMV) in more than 70% of cases. There is a rationale for using BiPAP in infants with bronchiolitis and worsening respiratory failure, but is this technique being used optimally?Delacroix et al. point out that the unfavorable results in their BiPAP group may have resulted from a suboptimal patient-ventilator interaction.14 Indeed, use of pressure support in spontaneous/timed modes requires inspiratory synchrony, expiratory synchrony, and rapid compensation for leaks in order to reach pre-established pressure values during inspiration.26Infants, especially when exhausted, have a higher respiratory rate, lower tidal volume, and weaker inspiratory efforts, making synchronization with their ventilator more complex.27Patient-ventilator asynchrony is frequent during IMV or NIV with pressure support in infants and children.28,29 In an elegant physiological study performed in infants with AVB, Baudin et al. characterized the main inspiratory asynchronies with noninvasive pressure assist control ventilation from diaphragmatic electrical activity recordings.30 Autotriggering, double triggering, and above all non-triggered breaths were observed for nearly 40% of the respiratory cycles, highlighting difficulties in detecting inspiratory effort in patients younger than 6 months, the targeted population in the study by Delacroix et al.14 These triggering asynchronies are associated with leaks, notably when BiPAP is performed with a nasal interface.31 This issue is explained by the insufficient sensitivity of the triggers with regard to the modest volumes and flows generated during inspiration at this young age.32 In addition, airway obstruction and dynamic hyperinflation may increase the frequency of ineffective respiratory efforts.30 The asynchrony index could be even higher if premature and late cycling are considered, i.e., asynchronies related to excessively long or short ventilator inspiratory times in relation to the neural command.28 These expiratory asynchronies are influenced by the ventilator’s mode and algorithm and may be improved by adjustments of the cycling-off criterion, which remains a difficult bedside challenge.28 In adults, patient-ventilator asynchrony has been associated with increased duration of mechanical ventilation, sleep disorders, prolonged ICU stay, and increased mortality.33 Such a demonstration has not been made in pediatrics, but recognition of this phenomenon and the analysis of its risk factors and consequences are much more recent.34 Currently, technological advances in ventilators have opened new horizons regarding synchronization, even in this group of patients. NIV software, management of leaks, and turbines specifically dedicated to NIV are indisputable advances.35 Neurally adjusted ventilatory assist (NAVA), initially developed for intubated patients, offers another option. In the field of severe AVB, an early report highlighted the interest of NAVA in providing less aggressive IMV and more comfort to the child.36 Discomfort during NIV is common in infants,22 and the prescription of sedatives is systematically considered by some teams.37 The discomfort may have multiple origins, including intolerance of the interface, skin breakdown, conjunctivitis, and gastric distension.38 Patient-ventilator asynchrony is another important source,39 which can be significantly improved with NAVA. Indeed, the direct analysis of diaphragmatic depolarization reduces the trigger delay, leading to more effective synchronization than with conventional NIV, even after careful optimization of the expiratory trigger setting.28,30,40 The asynchrony index may be reduced to 2%-8%, i.e., lower than the critical threshold of 10% defined in the adult population,41 with a nasal interface and in the presence of large leaks. One of the restraints on using NAVA is the extra cost it entails. However, the targeted population is limited to HFNC or CPAP failure, corresponding to 10-15% of moderate to severe AVB.15 A recent physiological study in severe AVB infants found that, compared to CPAP, NAVA was associated with a decreased work of breathing, lower neural drive and lower Ti/Ttot ratio.42 The promising results of this study suggest that pediatric intensivists must be as ambitious in combating asynchrony as they have been in combating pain and discomfort.43The impact on patient outcome will be judged in randomized controlled trials targeting severe forms of the disease.Disclosure: The authors declare no conflict of interest.

We herein report a 10-month-old female infant with a 4-month history of diarrhea with electrolyte abnormalities and growth impairment. A 4-cm right adrenal tumor was detected by computed tomography. No metastasis or accumulation on I123-metaiodobenzylguanidine scintigraphy was recognized in the tumor. A vasoactive intestinal peptide-secreting neuroblastic tumor was suspected, and octreotide was started, but the diarrhea persisted. Tumor extirpation was performed laparoscopically. After tumor removal, the symptoms improved immediately, and her growth caught up by nine months after surgery. A minimally invasive approach for pediatric solid tumor is difficult, especially for neuroblastoma, but may be beneficial for the patient's recovery.

Pediatric pulmonologists, and, indeed, general pediatricians, are exposed to the causative virus of Covid-19 , SARS-CoV2, in their daily outpatient practices from both symptomatic and asymptomatic patients. This risk naturally increases with multiple exposures over time. We have developed a simple equation to calculate the probability of a practitioner remaining Covid free over a specified time interval, given the local population prevalence of virus, the transmissibility of the organism or “attack rate,” the mitigating effects of personal protective equipment (PPE), and the number of patients seen over the time interval. The equation can be used to construct a Kaplan Meier -like plot for remaining Covid free. Since studies of transmission of SARS-CoV2 suggest a spectrum between droplet and aerosol spread, even in asymptomatic patients and absence of aerosol generating procedures, the type of masks protection worn by medical practitioners may mitigate risk to different degrees. Eye protection may mitigate the risk further. While the risk of acquiring Covid-19 in a year of practice is low, it is not negligible. However it can be minimized. These considerations may be helpful in deciding local risk to the practitioner according to practice volume and in choosing the level of PPE that would result in minimizing that risk.

Chinese flowering cabbage (Brassica rapa var. parachinensis) is a popular and widely cultivated leaf vegetable crop in Asia. Here, we performed a high quality de novo assembly of the 384 Mb genome of 10 chromosomes of a typical cultivar of Chinese flowering cabbage with an integrated approach using PacBio, Illumina, and Hi-C technology. We modeled 47,598 protein-coding genes in this analysis and annotated 52% (205.9/384) of its genome as repetitive sequences including 17% in DNA elements and 22% in long terminal retrotransposons (LTRs). Phylogenetic analysis reveals the genome of the Chinese flowering cabbage has a closer evolutionary relationship with the AA diploid progenitor of the allotetraploid species, Brassica juncea. Comparative genomic analysis of Brassica species with different subgenome types (A, B and C) reveals that the pericentromeric regions on chromosome 5 and 6 of the AA genome have been significantly expanded compared to the orthologous genomic regions in the BB and CC genomes, largely drive by LTR-retrotransposon amplification. This lineage-specific expansion may play a role in the species divergence in the Brassica genus. Furthermore, we found that a large amount of structural variations (SVs) identified within B. rapa lines that could impact coding genes, suggesting the functional significance of SVs on Brassica genome evolution. Overall, our high-quality genome assembly of the Chinese flowering cabbage provides a valuable genetic resource for deciphering the genome evolution of Brassica species and it can potentially serve as the reference genome guiding the molecular breeding practice of B. rapa crops.

Background: The quantitative assessment of neuroblastoma cell content in bone marrow aspirates for response evaluation has been introduced recently. Data on the concordance of interobserver reports are lacking so far. Methods: Investigators of seven European countries representing national reference or large oncological centres convened in 2016. They agreed to quantitatively assess routine bone marrow smears of the participating institutions and to discuss the discrepant results in joint meetings. Results From 2017 through 2019, three cytology rounds with 24, 28, and 28 bone marrow samples were run evaluating the representativity of the smears (yes/(restricted)/no) and the presence of tumors cells (yes/no and %). The comparison of the reports using κ (Fleiss) and α (Krippendorff) statistics demonstrated no robust reliabilities. The agreement on the representativity was moderate to poor, on the presence of tumor cells moderate to good and on the percentage of tumor cells slight to moderate. Though the unquestioned value of cytology to detect even tiny metastatic cells in bone marrow, the investigators unanimously agreed that a reliable quantification of the tumor cell content in bone marrow smears is unrealistic. For the key issue of representativity, a new practical definition was developed. Conclusion For any work with bone marrow aspirates the representativity of the material is of paramount importance. A practical definition is proposed. A reliable quantitative cytological assessment of tumor cell content in bone marrow aspirates is not feasible in metastatic neuroblastoma. Therefore its use as response criterion should be re-considered.