Comparison of test-retest reproducibility of DESPOT and 3D-QALAS for water and mapping.

Purpose: Relaxometry, specifically and mapping, has become an essential technique for assessing the properties of biological tissues related to various physiological and pathological conditions. Many techniques are being used to estimate and relaxation times, ranging from the traditional inversion or saturation recovery and spin-echo sequences to more advanced methods. Choosing the appropriate method for a specific application is critical since the precision and accuracy of and measurements are influenced by a variety of factors including the pulse sequence and its parameters, the inherent properties of the tissue being examined, the MRI hardware, and the image reconstruction.

Identification and Characterization of Chemotherapy-Resistant High-Risk Neuroblastoma Persister Cells.

Relapse rates in high-risk neuroblastoma remain exceedingly high. The malignant cells that are responsible for relapse have not been identified, and mechanisms of therapy resistance remain poorly understood. In this study, we used single-nucleus RNA sequencing and bulk whole-genome sequencing to identify and characterize the residual malignant persister cells that survive chemotherapy from a cohort of 20 matched diagnosis and definitive surgery tumor samples from patients treated with high-risk neuroblastoma induction chemotherapy.

Nuclear factor-κB activation by transforming growth factor-β1 drives tumour microenvironment-mediated drug resistance in neuroblastoma.

Background: Intrinsic and extrinsic factors in the tumour microenvironment (TME) contribute to therapeutic resistance. Here we demonstrate that transforming growth factor (TGF)-β1 produced in the TME increased drug resistance of neuroblastoma (NB) cells.

Methods: Human NB cell lines were tested in vitro for their sensitivity to Doxorubicin (DOX) and Etoposide (ETOP) in the presence of tumour-associated macrophages (TAM) and mesenchymal stromal cells/cancer-associated fibroblasts (MSC/CAF).

Fibroblasts and macrophages cooperate to create a pro-tumorigenic and immune resistant environment via activation of TGF-β/IL-6 pathway in neuroblastoma.

Tumor-associated macrophages (TAM) and cancer-associated fibroblasts (CAF) and their precursor mesenchymal stromal cells (MSC) are often detected together in tumors, but how they cooperate is not well understood. Here, we show that TAM and CAF are the most abundant nonmalignant cells and are present together in untreated human neuroblastoma (NB) tumors that are also poorly infiltrated with T and natural killer (NK) cells. We then show that MSC and CAF-MSC harvested from NB tumors protected human monocytes (MN) from spontaneous apoptosis in an interleukin (IL)-6 dependent mechanism.

To Estimate or to Forecast? Lessons From a Comparative Analysis of Four Bayesian Fitting Methods Based on Nonparametric Models.

Using pharmacokinetic (PK) models and Bayesian methods in dosing software facilitates the analysis of individual PK data and precision dosing. Several Bayesian methods are available for computing Bayesian posterior distributions using nonparametric population models. The objective of this study was to compare the performance of the maximum a posteriori (MAP) model, multiple model (MM), interacting MM (IMM), and novel hybrid MM(HMM) in estimating past concentrations and predicting future concentrations during therapy.

Neonatal brain metabolite concentrations: Associations with age, sex, and developmental outcomes.

Age and sex differences in brain metabolite concentrations in early life are not well understood. We examined the associations of age and sex with brain metabolite levels in healthy neonates, and investigated the associations between neonatal brain metabolite concentrations and developmental outcomes. Forty-one infants (36-42 gestational weeks at birth; 39% female) of predominantly Hispanic/Latina mothers (mean 18 years of age) underwent MRI scanning approximately two weeks after birth.

Intra-individual Pharmacokinetic Variability of Intravenous Busulfan in Hematopoietic Stem Cell-Transplanted Children.

Background: Busulfan therapeutic drug monitoring (TDM) is necessary to better achieve the target exposure in children before hematopoietic stem cell transplantation (HSCT). However, TDM-based dosing may be challenging if intra-individual pharmacokinetic variability (also denoted inter-occasion variability [IOV]) occurs during therapy.

Objectives: The objectives of this study were to describe and quantify busulfan IOV in children, and to investigate its potential determinants.

Evaluation of age-dependent treatment strategies for children and young adults with pineoblastoma: analysis of pooled European Society for Paediatric Oncology (SIOP-E) and US Head Start data.

Background: Pineoblastoma is a rare pineal region brain tumor. Treatment strategies have reflected those for other malignant embryonal brain tumors.

Patients And Methods: Original prospective treatment and outcome data from international trial groups were pooled.

Maternal prenatal iron status and tissue organization in the neonatal brain.

Background: Children prenatally exposed to inadequate iron have poorer motor and neurocognitive development. No prior study to our knowledge has assessed the influence of maternal prenatal iron intake on newborn brain tissue organization in full-term infants.

Methods: Third trimester daily iron intake was obtained using the Automated Self-Administered 24-h Dietary Recall with n = 40 healthy pregnant adolescents (aged 14-19 y).

Wnt pathway in atypical teratoid rhabdoid tumors.

Background: Atypical teratoid rhabdoid tumor (ATRT) is an aggressive pediatric brain tumor with limited therapeutic options. The hypothesis for this study was that the Wnt pathway triggered by the Wnt5B ligand plays an important role in ATRT biology. To address this hypothesis, the role of WNT5B and other Wnt pathway genes was analyzed in ATRT tissues and ATRT primary cell lines.

Use of the Palmaz stent in the treatment of severe tracheomalacia.

To present our experience with the use of the Palmaz stent in treating cases of severe, life-threatening tracheomalacia, and to report our experience with the use of tracheal stents in patients who have concomitant tracheotomies, we performed a retrospective study in a tertiary-care children's hospital. Nine patients with multiple congenital anomalies including severe tracheomalacia required placement of a Palmaz stent to prolong life. The congenital anomalies included congenital heart disease, congenital lung disease, meningomyelocele, laryngotracheoesophageal cleft, and tracheoesophageal fistula.

Thoracoscopic anterior spinal release and fusion: evolution of a faster, improved approach.

Purpose: The aim of this study was to compare the perioperative parameters and outcomes of video-assisted thoracoscopic surgery (VATS) with open thoracotomy for anterior release and fusion in the treatment of pediatric spinal deformities.

Methods: Twenty-six patients treated with VATS anterior spinal release and posterior spinal fusion by the authors were reviewed retrospectively. Fourteen age- and disease-matched patients who underwent open thoracotomy for anterior spinal release and posterior spinal fusion by the same group of surgeons during the same time period were evaluated for comparison.

A novel genetic island of meningitic Escherichia coli K1 containing the ibeA invasion gene (GimA): functional annotation and carbon-source-regulated invasion of human brain microvascular endothelial cells.

The IbeA (ibe10) gene is an invasion determinant contributing to E. coli K1 invasion of the blood-brain barrier. This gene has been cloned and characterized from the chromosome of an invasive cerebrospinal fluid isolate of E.

Acute myocarditis.

Myocarditis is defined as inflammation of the myocardium accompanied by myocellular necrosis. Acute myocarditis must be considered in patients who present with recent onset of cardiac failure or arrhythmia. Often there is a history of an antecedent flu-like illness.

Cellular mechanisms of microbial proteins contributing to invasion of the blood-brain barrier.

One of the least understood issues in the pathogenesis and pathophysiology of microbial infection of the central nervous system (CNS) is how microorganisms cross the blood-brain barrier (BBB), which separates brain interstitial space from blood and is formed by the tight junctions of brain microvascular endothelial cells (BMEC). BMEC monolayer and bilayer culture systems have been developed as in vitro models to dissect the mechanisms of adhesion and invasion involved in pathogenesis of CNS infection caused by microbes. Viral, bacterial, fungal and parasitic pathogens may breach the BBB and enter the CNS through paracellular, transcellular and/or Trojan horse mechanisms.

Bacterial penetration across the blood-brain barrier during the development of neonatal meningitis.

Bacterial pathogens may breach the blood-brain barrier (BBB) and invade the central nervous system through paracellular and/or transcellular mechanisms. Transcellular penetration, e.g.

Intestinal stoma complications in immunocompromised children.

Background/purpose: When performing an urgent gastrointestinal operation on an immunocompromised child, the pediatric surgeon may have to decide between performing an intestinal anastomosis (and risk leakage or sepsis) or creating an intestinal stoma. This study evaluates the postoperative course of those patients treated with intestinal stomas and the long-term survival rate of such patients.

Methods: A 13-year retrospective review of immunocompromised children with intestinal stomas was performed.

Venous ischemia as a cause of ureteral necrosis in transplanted ureters.

Background: Urologic complications after pediatric renal transplantation can adversely effect the outcome and may result in decreased graft survival. Efforts to prevent these complications are worthwhile. This study investigates the incidence of these complications in a clinical transplant program and reports on an animal model used to investigate one possible cause.

Tissue inhibitors of metalloproteinases (TIMP) in invasion and proliferation.

Tissue inhibitors of matrix metalloproteinases (TIMPs) are a family of natural inhibitors that control the activity of matrix metalloproteinases (MMPs) in the extracellular matrix (ECM). Four members of this family have been so far characterized in a variety of species. These inhibitors share a similar structural feature characterized by the presence of 12 cysteine residues involved in disulfide bonds and a similar function by their ability to form inhibitory complexes with MMPs.

Documentation of EWS gene rearrangements by fluorescence in-situ hybridization (FISH) in frozen sections of Ewing's sarcoma-peripheral primitive neuroectodermal tumor.

Prompt and accurate diagnosis of small round cell tumors warrants ancillary studies. Recently, two-color fluorescence in-situ hybridization (FISH) using probes for specific gene rearrangements has gained wide acceptance. EWS gene rearrangements, present in essentially 100% of Ewing's Sarcoma/peripheral primitive neuroectodermal tumor, were evaluated by FISH on frozen sections (FS) of tumor biopsies from 10 patients, plus a negative control, and in seven other malignant neoplasms of childhood.

Use of tubularized peritoneal free grafts as urethral substitutes in the rabbit.

As an alternative to bladder mucosa, free grafts of tubularized peritoneum were used as urethral substitutes in a rabbit model of hypospadias. In group 1, six mature rabbits underwent partial penile urethrectomy followed by interposition of a 2-cm-long peritoneal-lined tube graft. These animals had urethrograms performed at 3 months and were killed at 6 (n = 4) or 12 (n = 2) months.