Bone Marrow Mesenchymal Stem Cells Expanded Inside the Nichoid Micro-Scaffold: a Focus on Anti-Inflammatory Response.

Purpose: Mesenchymal stem cells (MSCs) represent a promising source for stem cell therapies in numerous diseases, including pediatric respiratory system diseases. Characterized by low immunogenicity, high anti-inflammatory, and immunoregulatory features, MSCs demonstrated an excellent therapeutic profile in numerous in vitro and preclinical models. MSCs reside in a specialized physiologic microenvironment, characterized by a unique combination of biophysical, biochemical, and cellular properties. The exploitation of the 3D micro-scaffold Nichoid, which simulates the native niche, enhanced the anti-inflammatory potential of stem cells through mechanical stimulation only, overcoming the limitation of biochemical and xenogenic growth factors application. Materials and Methods: In this work, we expanded pediatric bone marrow MSCs (BM-MSCs) inside the Nichoid and performed a complete cellular characterization with different approaches including viability assays, immunofluorescence analyses, RNA sequencing, and gene expression analysis. Results: We demonstrated that BM-MSCs inside the scaffold remain in a stem cell quiescent state mimicking the condition of the in vivo environment. Moreover, the gene expression profile of these cells shows a significant up-regulation of genes involved in immune response when compared with the flat control. Conclusion: The significant changes in the expression profile of anti-inflammatory genes could potentiate the therapeutic effect of BM-MSCs, encouraging the possible clinical translation for the treatment of pediatric congenital and acquired pulmonary disorders, including post-COVID lung manifestations. Lay Summary: Regenerative medicine is the research field integrating medicine, biology, and biomedical engineering. In this context, stem cells, which are a fundamental cell source able to regenerate tissues and restore damage in the body, are the key component for a regenerative therapeutic approach. When expanded outside the body, stem cells tend to differentiate spontaneously and lose regenerative potential due to external stimuli. For this reason, we exploit the scaffold named Nichoid, which mimics the in vivo cell niche architecture. In this scaffold, mesenchymal stem cells "feel at home" due to the three-dimensional mechanical stimuli, and our findings could be considered as an innovative culture system for the in vitro expansion of stem cells for clinical translation. Future Perspective: The increasing demand of safe and effective cell therapies projects our findings toward the possibility of improving cell therapies based on the use of BM-MSCs, particularly for their clinical translation in lung diseases.

Six-month multidisciplinary follow-up in multisystem inflammatory syndrome in children: An Italian single-center experience.

Background: A severe multisystem inflammatory syndrome in children (MIS-C) related to SARS-CoV-2 has been described after infection. A limited number of reports have analyzed the long-term complications related to pro-inflammatory status in MIS-C. We evaluated multiorgan impairment at the 6-month follow-up in MIS-C. Methods: We enrolled 33 pediatric patients consecutively hospitalized for MIS-C and monitored for almost 6 months. The inter-relationship of patient's features and disease severity at admission with long term complications was studied by multivariate analysis. Results: Endo-metabolic derangement, cardiac injury, respiratory, renal and gastrointestinal manifestations and neurological involvement are part of the initial presentation. The most abnormalities appear to resolve within the first few weeks, without significant long term dysfunction at the 6-months follow-up, except for endocrine (non-thyroidal illness syndrome in 12.1%, insulin resistance in 21.2%) and neurological system (27.3% cognitive or psychological, behavioral, adaptive difficulties). Endocrine and heart involvement at admission represent a significant factor on the long term sequelae; however no association between severity score and long-term outcome was noted. Conclusions: The severity of initial clinical presentation may be associated to organ domain, however it is not related to long term sequelae. The prevalent organ restoration supports a predominant indirect immune-mediated injury triggered by a systemic inflammatory response; however a direct damage due to the viral entry could be not excluded. Eventhought our preliminary results seem to suggest that MIS-C is not a long-term risk condition for children health, a longer follow-up is mandatory to confirm this hypothesis.

Epidemiological and Clinical Profile of Pediatric Burns in the COVID-19 Era: The Experience of a Reference Center.

Pediatric burns represent a significant public health problem. We analyzed the characteristics of pediatric burns in a reference center, in order to identify better strategies for prevention and care. Burn patients admitted to the pediatric departments of our hospital from January 2020 to June 2022 were retrospectively evaluated. Age, gender, the etiology of injuries, the total burn surface area (TBSA), the degree of burns, the length of hospital stay (LOS), concomitant SARS-CoV-2 infection, and burn surface microbial colonization were analyzed. Forty-seven patients were included in the analysis (M:F = 1:0.67). Most of the cases involved patients between 0 and 4 years of age (83%). Hot liquid burns accounted for 79% of cases, flame burns for 9%, thermal burns for 6%, scald burns for 4% and chemical burns for 2%. Mean TBSA was 14 ± 11%. A second-degree lesion was detected in 79% of patients and third-degree in 21%. Mean LOS was 17 days. No additional infection risks or major sequelae were reported in patients with SARS-CoV-2 infection. Fifteen different species of bacteria plus C. parapsilosis were isolated, while no anaerobic microorganisms were detected. In the light of our experience, we recommend a carefully planned and proactive management strategy, always multidisciplinary, to ensure the best care for the burned child.

Pediatric Surgical Care During the COVID-19 Lockdown: What Has Changed and Future Perspectives for Restarting in Italy. The Point of View of the Italian Society of Pediatric Surgery.

Background: The coronavirus disease 2019 (COVID-19) time exacerbated some of the conditions already considered critical in pediatric health assistance before the pandemic. A new form of pediatric social abandonment has arisen leading to diagnostic delays in surgical disorders and a lack of support for the chronic ones. Health services were interrupted and ministerial appointments for pediatric surgical healthcare reprogramming were postponed. As a result, any determination to regulate the term "pediatric" specificity was lost. The aim is, while facing the critical issues exacerbated by the COVID-19 pandemic, to rebuild future perspectives of pediatric surgical care in Italy. Methods: Each Pediatric Society, including the Italian Society of Pediatric Surgery (SICP), was asked by the Italian Federation of Pediatric Associations and Scientific Societies to fill a questionnaire, including the following the main issues: evaluation of pre-pandemic criticalities, pediatric care during the pandemic and recovery, and current criticalities. The future care model of our specialty was analyzed in the second part of the questionnaire. Results: Children are seriously penalized both for surgical treatment as well as for the diagnostic component. In most centers, the pediatric surgical teams have been integrated with the adult ones and the specificity of training the pediatric operating nursing is in danger of survival. "Emotional" management of the child is not considered by the general management and the child has become again an adults patient of reduced size. Conclusion: A new functional pediatric surgical model needs to be established in general hospitals, including activities for day surgery and outpatient surgery. To support the care of the fragile child, a national health plan for the pediatric surgery is required.

Very High Negative Concordance Rate of RT-PCR for SARS-CoV-2 in Nasopharyngeal Swab and Tracheo-Bronchial Aspirate in Children

Reliable testing methods for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in children are essential to allow normal activities. Diagnosis of SARS-CoV-2 infection is currently based on real-time reverse transcriptase-polymerase chain reaction (RT-PCR) performed on nasopharyngeal (NP) swabs;concerns have been raised regarding NP swab accuracy in children to detect the virus because of potential lack of cooperation of the patients or due to general uncertainties about concordance between high and low respiratory tract specimens in children. The aim of the study (IRB approval: ST/2020/405) is to prospectively compare RT-PCR results on NP and tracheo-bronchial aspirate (TA) in children admitted to the hospital for surgery or admitted to the Pediatric Intensive Care Unit (PICU) of a tertiary children hospital in Milano, Italy, during a peak of COVID-19 infections in the city. A total of 385 patients were enrolled in the study: 364 from surgical theater and 21 from PICU. Two patients (0.5%) tested positive on TA and were negative on NP;both cases occurred in November 2020, during a peak of infection in the city. Specificity of NP swab was.995 (95% CI: 0.980–0.999). Two patients with positive NP swabs tested negative on TA. Conclusion Our study shows that the specificity of SARS-CoV-2 RT-PCR on TA swab, compared to results of SARS-CoV-2 RT-PCR on NP, was very high for negative cases in our pediatric cohort during a period of high epidemiological pressure.

SARS-CoV-2 Exposed Mesenchymal Stromal Cell from Congenital Pulmonary Airway Malformations: Transcriptomic Analysis and the Expression of Immunomodulatory Genes.

The inflammatory response plays a central role in the complications of congenital pulmonary airway malformations (CPAM) and severe coronavirus disease 2019 (COVID-19). The aim of this study was to evaluate the transcriptional changes induced by SARS-CoV-2 exposure in pediatric MSCs derived from pediatric lung (MSCs-lung) and CPAM tissues (MSCs-CPAM) in order to elucidate potential pathways involved in SARS-CoV-2 infection in a condition of exacerbated inflammatory response. MSCs-lung and MSCs-CPAM do not express angiotensin-converting enzyme 2 (ACE2) and transmembrane serine protease 2 (TRMPSS2). SARS-CoV-2 appears to be unable to replicate in MSCs-CPAM and MSCs-lung. MSCs-lung and MSCs-CPAM maintained the expression of stemness markers MSCs-lung show an inflammatory response (IL6, IL1B, CXCL8, and CXCL10), and the activation of Notch3 non-canonical pathway; this route appears silent in MSCs-CPAM, and cytokine genes expression is reduced. Decreased value of p21 in MSCs-lung suggested no cell cycle block, and cells did not undergo apoptosis. MSCs-lung appears to increase genes associated with immunomodulatory function but could contribute to inflammation, while MSCs-CPAM keeps stable or reduce the immunomodulatory receptors expression, but they also reduce their cytokines expression. These data indicated that, independently from their perilesional or cystic origin, the MSCs populations already present in a patient affected with CPAM are not permissive for SARS-CoV-2 entry, and they will not spread the disease in case of infection. Moreover, these MSCs will not undergo apoptosis when they come in contact with SARS-CoV-2; on the contrary, they maintain their staminality profile.

Transcriptomic Analysis of HCN-2 Cells Suggests Connection among Oxidative Stress, Senescence, and Neuron Death after SARS-CoV-2 Infection.

According to the neurological symptoms of SARS-CoV-2 infection, it is known that the nervous system is influenced by the virus. We used pediatric human cerebral cortical cell line HCN-2 as a neuronal model of SARS-CoV-2 infection, and, through transcriptomic analysis, our aim was to evaluate the effect of SARS-CoV-2 in this type of cells. Transcriptome analyses revealed impairment in TXN gene, resulting in deregulation of its antioxidant functions, as well as a decrease in the DNA-repairing mechanism, as indicated by the decrease in KAT5. Western blot analyses of SOD1 and iNOS confirmed the impairment of reduction mechanisms and an increase in oxidative stress. Upregulation of CDKN2A and a decrease in CDK4 and CDK6 point to the blocking of the cell cycle that, according to the deregulation of repairing mechanism, has apoptosis as the outcome. A high level of proapoptotic gene PMAIP1 is indeed coherent with neuronal death, as also supported by increased levels of caspase 3. The upregulation of cell-cycle-blocking genes and apoptosis suggests a sufferance state of neurons after SARS-CoV-2 infection, followed by their inevitable death, which can explain the neurological symptoms reported. Further analyses are required to deeply explain the mechanisms and find potential treatments to protect neurons from oxidative stress and prevent their death.

SARS-CoV-2 Infected Pediatric Cerebral Cortical Neurons: Transcriptomic Analysis and Potential Role of Toll-like Receptors in Pathogenesis.

Different mechanisms were proposed as responsible for COVID-19 neurological symptoms but a clear one has not been established yet. In this work we aimed to study SARS-CoV-2 capacity to infect pediatric human cortical neuronal HCN-2 cells, studying the changes in the transcriptomic profile by next generation sequencing. SARS-CoV-2 was able to replicate in HCN-2 cells, that did not express ACE2, confirmed also with Western blot, and TMPRSS2. Looking for pattern recognition receptor expression, we found the deregulation of scavenger receptors, such as SR-B1, and the downregulation of genes encoding for Nod-like receptors. On the other hand, TLR1, TLR4 and TLR6 encoding for Toll-like receptors (TLRs) were upregulated. We also found the upregulation of genes encoding for ERK, JNK, NF-κB and Caspase 8 in our transcriptomic analysis. Regarding the expression of known receptors for viral RNA, only RIG-1 showed an increased expression; downstream RIG-1, the genes encoding for TRAF3, IKKε and IRF3 were downregulated. We also found the upregulation of genes encoding for chemokines and accordingly we found an increase in cytokine/chemokine levels in the medium. According to our results, it is possible to speculate that additionally to ACE2 and TMPRSS2, also other receptors may interact with SARS-CoV-2 proteins and mediate its entry or pathogenesis in pediatric cortical neurons infected with SARS-CoV-2. In particular, TLRs signaling could be crucial for the neurological involvement related to SARS-CoV-2 infection.

Impaired Glucose-Insulin Metabolism in Multisystem Inflammatory Syndrome Related to SARS-CoV-2 in Children.

An interaction between metabolic glucose impairment and coronavirus disease 2019 is reported. The development of a severe multisystem inflammatory syndrome in children (MIS-C) related to SARS-CoV-2 infection has been described. We evaluated the impact of MIS-C on glycemic patterns in pediatric patients. A group of 30 children and adolescents affected by MIS-C were considered; all patients were normal weight. Clinical and biochemical assessments, including surrogate markers of insulin resistance (IR) such as homeostasis model analysis-IR (HOMA-IR) and triglyceride-glucose (TyG) indexes, were recorded. Patients were also invited to undergo an intermittently scanned continuous glucose monitoring (isCGM). HOMA-IR index was calculated in 18 patients (60%), of which 17 (94%) revealed a pathological value. TyG index was computed for all patients and pathological values were detected in all cases. In 15 patients, isCGM data were recorded on average for 9 days (±3 days). Overall, average glucose was 105 mg/dL (±16 mg/dL) and average time spent in the 70-180 mg/dL range (TIR) was 93.76%, with nearly 10% of glucose readings in the 141-180 mg/dL range; glycemic fluctuations over the hyperglycemic threshold were detected in four patients. Regular glucose monitoring may be useful to prevent metabolic imbalance and obtain a better outcome.

Supporting the Regional Network for Children with Burn Injuries in a Pediatric Referral Hospital for COVID-19.

Considerable reorganization of the regional network for pediatric burn treatment during the pandemic was required to cope with severe burn injuries in small children. In support of the emergency network for burns during the COVID-19 pandemic, we referred to regional indications for centralization in our hospital for all children aged less than 5 years who presented with severe burns, >15% of total body surface area (TBSA), or who necessitated admittance to the pediatric intensive care unit (PICU). A new service with a dedicated management protocol was set up to treat pediatric burns in our SARS-CoV-2 pediatric hospital during the lockdown period. A multidisciplinary burn treatment team was set up to offer compassionate and comprehensive burn care. Patient's clinical data, burn features, treatment and follow up were recorded. A higher number of admissions was recorded from February to December 2020 compared with the same period in 2019 (52 vs. 32 admissions). Eighteen patients were admitted to the COVID-19 Service (10 M/8 F; 3.10 ± 2.6 yrs); ten children (55.5%) were hospitalized in the ward and eight in the ICU (44.5%). Fifty percent of the cases presented with lesions extending over >15% TBSA; in one case, TBSA was 35%. All patients suffered 2nd-degree burns; while five patients also had 3rd degree lesions covering more than 15% TBSA. All of the injuries occurred at home. No major secondary infections were recorded. Successful treatment was achieved in 94.4% of cases. The average length of stay was 15.2 ± 12.6 days. A proactive, carefully planned service, involving a multidisciplinary team, was created to ensure appropriate care in a pediatric hospital during the COVID-19 period, despite the effective pandemic associated challenges. Better health promotion in pediatric burn cases should also include dedicated TBSA assessment and a database of children's burn characteristics.

Organizational aspects of pediatric anesthesia and surgery between two waves of Covid-19.

BACKGROUND: The initial wave of the Covid-19 pandemic has hit Italy, and Lombardy in particular, with violence, forcing to reshape all hospitals' activities; this happened even in pediatric hospitals, although the young population seemed initially spared from the disease. "Vittore Buzzi" Children's Hospital, which is a pediatric/maternal hospital located in Milan (Lombardy Region), had to stop elective procedures-with the exception of urgent/emergent ones-between February and May 2020 to leave space and resources to adults' care. We describe the challenges of reshaping the hospital's identity and structure, and restarting pediatric surgery and anesthesia, from May on, in the most hit area of the world, with the purpose to avoid and contain infections. Both patients and caregivers admitted to hospital have been tested for Sars-CoV-2 in every case. METHODS: Observational cohort study via review of clinical charts of patients undergoing surgery between 16th May and 30th September 2020, together with SARS-CoV -2 RT-PCR testing outcomes, and comparison to same period surgeries in 2019. RESULTS: An increase of approximately 70% in pediatric surgeries (OR 1.68 [1.33-2.13], P < .001) and a higher increase in the number of surgeries were reported (OR 1.75 (1.43-2.15), P < .001). Considering only urgent procedures, a significant difference in the distribution of the type of surgery was observed (Chi-squared P-value < .001). Sars-CoV-2-positive patients have been 0.8% of total number; 14% of these was discovered through caregiver's positivity. CONCLUSION: We describe our pathway for safe pediatric surgery and anesthesia and the importance of testing both patient and caregiver.

The Challenges of a Children's Hospital during the COVID-19 Pandemic: The Pediatric Surgeon's Point of View.

During the coronavirus disease of 2019 (COVID-19) emergency, in the pediatric surgical setting, it has been essential to avoid and contain infections as well as to protect both the patients and the surgical team. During this emergency, procedures and workflow were adapted to provide the safest possible environment for both the surgical team and the patients. Pediatric surgical activities were reorganized during the COVID-19 pandemic at the "Vittore Buzzi" Children's Hospital, which is a pediatric/maternal hospital located in Milan (Lombardy Region), Italy. Resources were optimized in order to maintain high levels of care and quality of assistance. During the COVID-19 emergency, the pediatric surgical department at the "Vittore Buzzi" Children's Hospital became an acute care surgical service. For the reorganization of surgical activities, institutional protocols were adapted in order to preserve the pediatric-specific characteristics of our service; five crucial points were specifically addressed. The pediatric surgical procedures carried out during the initial two months of the Italian lockdown are also reported. Continuity of care was maintained for children affected by severe diseases, such as tumors and neurosurgical conditions, whose treatment could not be deferred. Telemedicine and telecommunication were adopted as quick-support modalities for pre- and post-operative care. This reorganization allowed us to preserve the "pediatric specificity" and all care-related procedures offered at this high-quality/high-volume surgical care referral center.

Appendicitis in Children in a Large Italian COVID-19 Pandemic Area.

Introduction: The coronavirus disease 2019 (COVID-19) pandemic has dramatically changed the routine activities of pediatric surgical centers, and it determined the reduction of admissions in the pediatric emergency departments (PED). We reviewed the records of patients affected by acute appendicitis (AA) during the COVID-19 pandemic period in a large Italian COVID-19 pandemic area. Methods: Data regarding demographics, age, macroscopic and microscopic findings, and time between symptom onset and PED admission of patients affected by confirmed AA in the period between March and April 2020 were considered. The data were compared with those obtained during the same period of 2019, 2018, and 2017 in the included centers. Data were quoted as median (range) or absolute number. Non-parametric statistical tests were used to compare groups. A p ≤ 0.05 was regarded as significant. Since only anonymous data have been used and the data storage meets current data protection regulations, ethical committee approval was not required for this study. Results: Eighty-six patients underwent surgical appendectomy for AA between February 20th, 2020 and April 20th, 2020; 32.5% were complicated appendicitis and 67.5% were uncomplicated. Fifty-three patients were males and 33 were females. Patients' age ranged from 3 to 17 years and the median age was 10 years. The median time between the onset of symptoms and the admission in PED was 1.85 days. The average time between the symptom onset and PED admission was 1.8 days. Conclusions: Although fear from the COVID-19 pandemic determined a delayed diagnosis of serious pediatric diseases, the increasing prevalence and severity of AA were not demonstrated in the most COVID-19-affected areas of Italy.

The Challenges of a Children’s Hospital during the COVID-19 Pandemic: The Pediatric Surgeon’s Point of View

During the coronavirus disease of 2019 (COVID-19) emergency, in the pediatric surgical setting, it has been essential to avoid and contain infections as well as to protect both the patients and the surgical team. During this emergency, procedures and workflow were adapted to provide the safest possible environment for both the surgical team and the patients. Pediatric surgical activities were reorganized during the COVID-19 pandemic at the “Vittore Buzzi”Children’s Hospital, which is a pediatric/maternal hospital located in Milan (Lombardy Region), Italy. Resources were optimized in order to maintain high levels of care and quality of assistance. During the COVID-19 emergency, the pediatric surgical department at the “Vittore Buzzi”Children’s Hospital became an acute care surgical service. For the reorganization of surgical activities, institutional protocols were adapted in order to preserve the pediatric-specific characteristics of our service;five crucial points were specifically addressed. The pediatric surgical procedures carried out during the initial two months of the Italian lockdown are also reported. Continuity of care was maintained for children affected by severe diseases, such as tumors and neurosurgical conditions, whose treatment could not be deferred. Telemedicine and telecommunication were adopted as quick-support modalities for pre- and post-operative care. This reorganization allowed us to preserve the “pediatric specificity”and all care-related procedures offered at this high-quality/high-volume surgical care referral center.