Perinatal thymic-derived CD8αß-expressing γδ T cells are innate IFN-γ producers that expand in IL-7R-STAT5B-driven neoplasms.

The contribution of γδ T cells to immune responses is associated with rapid secretion of interferon-γ (IFN-γ). Here, we show a perinatal thymic wave of innate IFN-γ-producing γδ T cells that express CD8αß heterodimers and expand in preclinical models of infection and cancer. Optimal CD8αß+ γδ T cell development is directed by low T cell receptor signaling and through provision of interleukin (IL)-4 and IL-7. This population is pathologically relevant as overactive, or constitutive, IL-7R-STAT5B signaling promotes a supraphysiological accumulation of CD8αß+ γδ T cells in the thymus and peripheral lymphoid organs in two mouse models of T cell neoplasia. Likewise, CD8αß+ γδ T cells define a distinct subset of human T cell acute lymphoblastic leukemia pediatric patients. This work characterizes the normal and malignant development of CD8αß+ γδ T cells that are enriched in early life and contribute to innate IFN-γ responses to infection and cancer.

Identification of fibroblast progenitors in the developing mouse thymus.

The thymus stroma constitutes a fundamental microenvironment for T-cell generation. Despite the chief contribution of thymic epithelial cells, recent studies emphasize the regulatory role of mesenchymal cells in thymic function. Mesenchymal progenitors are suggested to exist in the postnatal thymus; nonetheless, an understanding of their nature and the mechanism controlling their homeostasis in vivo remains elusive. We resolved two new thymic fibroblast subsets with distinct developmental features. Whereas CD140αß+GP38+SCA-1- cells prevailed in the embryonic thymus and declined thereafter, CD140αß+GP38+SCA-1+ cells emerged in the late embryonic period and predominated in postnatal life. The fibroblastic-associated transcriptional programme was upregulated in CD140αß+GP38+SCA-1+ cells, suggesting that they represent a mature subset. Lineage analysis showed that CD140αß+GP38+SCA-1+ maintained their phenotype in thymic organoids. Strikingly, CD140αß+GP38+SCA-1- generated CD140αß+GP38+SCA-1+, inferring that this subset harboured progenitor cell activity. Moreover, the abundance of CD140αß+GP38+SCA-1+ fibroblasts was gradually reduced in Rag2-/- and Rag2-/-Il2rg-/- thymi, indicating that fibroblast maturation depends on thymic crosstalk. Our findings identify CD140αß+GP38+SCA-1- as a source of fibroblast progenitors and define SCA-1 as a marker for developmental stages of thymic fibroblast differentiation.

Characterization of technical skill progress in a standardized rabbit model for training in laparoscopic duodenal atresia repair.

BACKGROUND: Laboratory skills training is an essential step before conducting minimally invasive surgery in clinical practice. Our main aim was to develop an animal model for training in clinically highly challenging laparoscopic duodenal atresia repair that could be useful in establishing a minimum number of repetitions to indicate safe performance of similar interventions on humans. MATERIALS AND METHODS: A rabbit model of laparoscopic duodenum atresia surgery involving a diamond-shaped duodeno-duodenostomy was designed. This approach was tested in two groups of surgeons: in a beginner group without any previous clinical laparoscopic experience (but having undergone previous standardized dry-lab training, n = 8) and in an advanced group comprising pediatric surgery fellows with previous clinical experience of laparoscopy (n = 7). Each participant performed eight interventions. Surgical time, expert assessment using the Global Operative Assessment of Laparoscopic Skills (GOALS) score, anastomosis quality (leakage) and results from participant feedback questionnaires were analyzed. RESULTS: Participants in both groups successfully completed all eight surgeries. The surgical time gradually improved in both groups, but it was typically shorter in the advanced group than in the beginner group. The leakage rate was significantly lower in the advanced group in the first two interventions, and it reached its optimal level after five operations in both groups. The GOALS and participant feedback scores showed gradual increases, evident even after the fifth surgery. CONCLUSIONS: Our data confirm the feasibility of this advanced pediatric laparoscopic model. Surgical time, anastomosis quality, GOALS score and self-assessment parameters adequately quantify technical improvement among the participants. Anastomosis quality reaches its optimal value after the fifth operation even in novice, but uniformly trained surgeons. A minimum number of wet-lab operations can be determined before surgery can be safely conducted in a clinical setting, where the development of further non-technical skills is also required.

Nanoparticles for Targeted Brain Drug Delivery: What Do We Know?

The blood-brain barrier (BBB) is a barrier that separates the blood from the brain tissue and possesses unique characteristics that make the delivery of drugs to the brain a great challenge. To achieve this purpose, it is necessary to design strategies to allow BBB passage, in order to reach the brain and target the desired anatomic region. The use of nanomedicine has great potential to overcome this problem, since one can modify nanoparticles with strategic molecules that can interact with the BBB and induce uptake through the brain endothelial cells and consequently reach the brain tissue. This review addresses the potential of nanomedicines to treat neurological diseases by using nanoparticles specially developed to cross the BBB.

Trans-umbilical laparoscopic-assisted appendectomy in the pediatric population: comparing single-incision and 2-trocar techniques.

INTRODUCTION: Trans-umbilical laparoscopic-assisted appendectomy (TULAA) combines advantages of open surgery with benefits of laparoscopy and can be performed either by single-incision or with two trocars; the present study aims to compare outcomes and cost of these techniques in a pediatric serie. MATERIAL AND METHODS: Patients undergoing TULAA between July 2013 and June 2014 were retrospectively reviewed. There were two groups: A (single-incision) - one umbilical trocar for a telescope with inbuilt working channel; and B (2-trocar) - one umbilical trocar for a 'standard' telescope plus a supra-pubic trocar for instruments. RESULTS: One-hundred and eighty-nine patients (112 males, age: 12[2-17] years) underwent TULAA; 32(17%) presented with perforated appendicitis. Group A encompassed 157 and group B 32 patients; age, gender, proportion of perforated appendicitis, and follow-up were similar. Operative time was 46 [21-145] min in group A, and 54.5[30-111] in group B (A vs B, p = 0.087). Length of hospital stay was 2 [1;22] days in group B, and 2 [0;24] in group A (A vs B, p = 0.136). The prevalence of post-operative complications was similar: 11 (7%) cases in group A and 2 (6.3%) intra-abdominal abscesses in group B. Using disposable trocars, the more expensive starting point of single-incision technique may be reversed after 27 procedures. CONCLUSION: Single-incision and 2-trocar TULAA are effective techniques with low complication rates and similar outcomes. Despite being technically more demanding, single incision may be advantageous because there are no visible scars, and potentially cheaper in hospitals where disposable trocars are used.

Intraoperative acidosis and hypercapnia during thoracoscopic repair of congenital diaphragmatic hernia and esophageal atresia/tracheoesophageal fistula.

BACKGROUND: Intraoperative hypercapnia and acidosis have been associated with thoracoscopic repair of both congenital diaphragmatic hernia and esophageal atresia/tracheoesophageal fistula. AIM: The aim of the present study was to investigate whether thoracoscopic repair of congenital diaphragmatic hernia or esophageal atresia/tracheoesophageal fistula was associated with acidosis and hypercapnia in a large group of neonates, and to analyze the effects of acidosis and hypercapnia on early postoperative outcomes. METHODS: We reviewed the charts of neonates who underwent open or thoracoscopic congenital diaphragmatic hernia or esophageal atresia/tracheoesophageal fistula repair (2004-2014). Patients with available intraoperative arterial gas values were included. Data (PaCO2 : mm Hg) were compared using paired/unpaired tests and are reported as difference [95% confidence interval]. RESULTS: Congenital diaphragmatic hernia: 187 neonates underwent open (n=153) or thoracoscopic (n=34) repair. Intraoperative arterial gas values were recorded in 96 open and in 23 thoracoscopic operations. Both groups had similar preoperative pH and PaCO2 , and developed intraoperative acidosis (open -0.08 [-0.11, -0.05] P<.001, thoracoscopic -0.14 [-0.24, -0.04] P=.01) and hypercapnia (open: 7.8 [3.2, 12.4], P=.002; thoracoscopic: 20.2 [-2.5, 43, P=.07). Intraoperatively, neonates undergoing thoracoscopic repair developed lower pH than those having open surgery (-0.06 [-0.01, -0.10] P=.018), but maintained similar levels of PaCO2 (-4.0 [-9.0, 4.4] P=.39). Esophageal atresia/tracheoesophageal fistula: 205 neonates underwent open (n=180) or thoracoscopic (n=25) repair. Intraoperative arterial gas values were recorded in 62 open and in 14 thoracoscopic operations. Both groups had similar preoperative pH and PaCO2 , and developed intraoperative acidosis (open: -0.09 [-0.14, -0.04], P<.001; thoracoscopic: 0.21 [-0.28, -0.14], P<.001) and hypercapnia (open: 9.2 [2.6, 15.7] P=.008; thoracoscopic: 15.2 [1.6, 28.7], P=.03). Intraoperatively, neonates undergoing thoracoscopic repair developed lower pH than those having open surgery (difference 0.08 [0.01, 0.15], P=.02) but maintained similar levels of PaCO2 (difference -1 [-9, 3], P=.35). CONCLUSION: Neonates undergoing operative repair of congenital diaphragmatic hernia and esophageal atresia/tracheoesophageal fistula develop intraoperative acidosis and hypercapnia, regardless of the approach used. However, this phenomenon is more severe during thoracoscopic repair. Novel modalities to reduce intraoperative gas derangements, particularly during thoracoscopic repair, need to be established.

Thoracoscopic Pleural Abrasion in Neonatal Recurrent Pneumothorax.

Recurrent pneumothorax is a rare neonatal condition and there are few cases reporting surgical treatment, mainly based on adult studies. We present a male, term newborn that after four recurrent spontaneous pneumothorax (treated with pleural needle aspiration and drains) underwent thoracoscopic mechanical pleural abrasion. There were no post-operatory complications and no recurrence reported until the second year of life. We believe that this technique is safe and effective and may play an important role in these cases.

The Early Postnatal Life: A Dynamic Period in Thymic Epithelial Cell Differentiation.

The microenvironments formed by cortical (c) and medullary (m) thymic epithelial cells (TECs) play a non-redundant role in the generation of functionally diverse and self-tolerant T cells. The role of TECs during the first weeks of the murine postnatal life is particularly challenging due to the significant augment in T cell production. Here, we critically review recent studies centered on the timely coordination between the expansion and maturation of TECs during this period and their specialized role in T cell development and selection. We further discuss how aging impacts on the pool of TEC progenitors and maintenance of functionally thymic epithelial microenvironments, and the implications of these chances in the capacity of the thymus to sustain regular thymopoiesis throughout life.

Nanotechnology Innovations to Enhance the Therapeutic Efficacy of Quercetin.

Quercetin is a flavonol present in many vegetables and fruits. Generally, quercetin can be found in aglycone and glycoside forms, mainly in leaves. The absorption of this compound occurs in the large and small intestine, where it suffers glucuronidation, sulfidation, and methylation to improve hydrophilicity. After metabolization, which occurs mainly in the gut, it is distributed throughout the whole organism and is excreted by feces, urine, and exhalation of carbon dioxide. Despite its in vitro cytotoxicity effects, in vivo studies with animal models ensure its safety. This compound can protect against cancer, cardiovascular diseases, chronic inflammation, oxidative stress, and neurodegenerative diseases due to its radical scavenging and anti-inflammatory properties. However, its poor bioavailability dampens the potential beneficial effects of this flavonoid. In that sense, many types of nanocarriers have been developed to improve quercetin solubility, as well as to design tissue-specific delivery systems. All these studies manage to improve the bioavailability of quercetin, allowing it to increase its concentration in the desired places. Collectively, quercetin can become a promising compound if nanotechnology is employed as a tool to enhance its therapeutic efficacy.

Learning Curves for Laparoscopic Repair of Inguinal Hernia and Communicating Hydrocele in Children.

INTRODUCTION: We analyzed the department and surgeon learning curves during implementation of the percutaneous internal ring suturing (PIRS) technique in our department. METHODS: Children proposed for inguinal hernia or communicating hydrocele repair were included (n = 607). After mentorship, all surgeons were free to propose open or PIRS repair. From gathered data, we assessed department and surgeon learning curves through cumulative experience focusing in perioperative complications, conversion, ipsilateral recurrence, postoperative complications, and metachronous hernia, with benchmarks defined by open repair. RESULTS: Department-centered analysis revealed that perioperative complications, conversion, and ipsilateral recurrence rates were higher in the beginning, reaching the benchmarks when each surgeon performed, at least, 35 laparoscopic repairs. Postoperative complications and metachronous hernia rates were independent from learning curves, with the metachronous hernia rate being significantly lower in PIRS patients. During the program, the percentage of males in those operated by PIRS progressively increased reaching the percentage of males, in our sample, when department operated over 230 cases. CONCLUSION: Thirty-five laparoscopic cases per surgeon are required for perioperative complications, conversion, and ipsilateral recurrence reach the benchmark. The gap between the percentage of males, in those operated by PIRS and in those proposed for surgery, monitors the confidence of the team in the program.

Prenatal and Postnatal Management of Congenital Pulmonary Airway Malformation.

Congenital pulmonary airway malformation (CPAM) is one of the most common lung lesions detected prenatally. Despite the research efforts made in the past few years, controversy and lack of clarity in the literature still exist regarding nomenclature, classification, pathogenesis and the management of CPAM. Therefore, it is of greatest importance to delineate the natural history of CPAMs and to create a consensus to guide the management and follow-up of these lesions. This review will focus on classification systems, highlighting the most recent advancements in pathogenesis, and current practice in the prenatal diagnosis of CPAM. Strategies of prenatal management and postnatal management will be reviewed. Long-term follow-up, including lung cancer risk, is discussed and an outcome perspective is presented.

Anatomic Thoracoscopic Repair of Esophageal Atresia.

BACKGROUND: The thoracoscopic approach to repair esophageal atresia (EA) with tracheoesophageal fistula (TEF) provides excellent view, allowing the most skillful surgeons to spare the azygos vein by performing the esophageal anastomosis over (on the right side) the azygos vein. Seeking the most anatomic repair, we started to perform the esophageal anastomosis underneath (on the left side) the azygos vein: anatomic thoracoscopic repair of esophageal atresia (ATREA). We aim to compare results of ATREA with the classic thoracoscopic repair. METHODS: During the last 4 years, in our center, all infants with EA with distal TEF were operated by thoracoscopy sparing the azygos vein. According to the surgical technique, two groups were created: Group A-treated with ATREA and Group B-treated with classic thoracoscopic repair over (on the right side) the azygos vein. We retrospectively collected data regarding features of the newborn (gestational age, gender, karyotype changes, associated anomalies, birth weight), surgery (operative technique, operative time, and surgical complications), hospitalization (duration of mechanical ventilation, thoracic drainage, time for the first feeding, time of admission, and early complications) and follow-up [tracheomalacia, gastroesophageal reflux disease (GERD), anastomotic stricture, recurrence of fistula]. RESULTS: Group A had seven newborns and Group B had four newborns. There were no statistically significant differences between both groups concerning the evaluated variables on surgery, hospitalization, and follow-up. Nevertheless, in Group A, there was an infant with a right aortic arch where ATREA was particularly useful as it avoided that the azygos vein and the aortic arch were left compressed in between the esophagus and trachea. Postoperatively, one patient of Group B had a major anastomotic leak with empyema requiring surgical re-intervention. During follow-up, anastomotic stricture requiring esophageal dilation occurred with similar rates in both groups. In Group B, one patient had severe and symptomatic tracheomalacia requiring aortopexy and severe GERD requiring fundoplication. No patients developed recurrent fistula. CONCLUSION: The ATREA is feasible in the great majority of patients with EA with TEF without compromising long-term results and might be particularly useful for those infants with malformations of the cardiac venous return vessels and/or major aortic malformations.

Pulmonary Myofibroblastic Tumour Involving the Pericardium and Left Atrium in an 18 Month Infant.

Inflammatory myofibroblastic tumor (IMT) is the most frequent primary lung tumor in children and it may be locally aggressive. The management of a locally advanced pulmonary IMT in an 18 month-old female child is presented.A left pulmonary mass was incidentally found on the computerized tomography (CT) scan of a child with persistent systemic inflammatory syndrome. Biopsy confirmed the diagnosis; after preoperative corticotherapy, left pneumonectomy was performed. The pericardium and left atrium were invaded and resected, requiring pericardial reconstruction. There is no relapse at four years of follow-up.Steroids play a role in tumor size reduction, but marginal resection is the gold standard. Extended approaches are feasible and often required in advanced cases.

Sparing internal thoracic vessels in thoracoscopic or submuscular correction of pectus carinatum: A porcine model study.

BACKGROUND: External compression is used for pectus carinatum (PC) treatment, but many patients are noncompliant. Costal cartilage resection (CCR) has been described as an alternative, but these approaches sacrifice the internal thoracic arteries (ITA). We aim to assess the feasibility of CCR sparing ITA comparing thoracoscopic and subcutaneous endoscopic approaches. METHODS: Twelve pigs were used as models for surgical PC correction and randomized for 2 groups: thoracoscopy (T) and subcutaneous (subpectoralis) endoscopy (SP). In both groups, CCR from 3rd 4th and 5th ribs was performed avoiding ITA damage. ITA preservation was confirmed by Doppler-ultrasound as well as postmortem injection of methylene blue. Four persons evaluated the procedures being difficult, using a 6-item modified validated scale. RESULTS: In both techniques, the procedure was accomplished in all animals sparing ITAs. CCR was faster in T than in SP (49±5 vs. 65±16minutes, p<0.05). T was classified as easier than SP (p<0.001) with a significantly higher score for all items, especially better image and tissue handling. DISCUSSION: Sparing the ITAs during CCR for correction of PC is feasible in a porcine model and might be a goal in humans. The thoracoscopic approach allows for a faster and easier procedure.

Duhamel pull-through assisted by transrectal port: a hybrid natural orifice transluminal endoscopic surgery approach.

One of the latest surgical innovations is natural orifice transluminal endoscopic surgery (NOTES). We hypothesize that the principles of NOTES could be applied to the laparoscopic Duhamel procedure. Between March 2008 and May 2010, 3 children underwent the laparoscopic Duhamel procedure assisted by transrectal NOTES. Three 5-mm transabdominal trocars were combined with a 12-mm transrectal trocar. We were able to safely apply the principles of NOTES, improving the performance of laparoscopic Duhamel pull-through using current instruments and technology. This new approach avoids the need of an extra transabdominal 12-mm trocar for the endoscopic stapler, allows an easier creation of a smaller rectal stump, and offers the possibility of an extra working port. This hybrid concept can be seen as a transition into the emerging field of NOTES in colorectal surgery.