Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 20 de 110
Filter
1.
Cell ; 2024 Jul 04.
Article in English | MEDLINE | ID: mdl-38986619

ABSTRACT

Posterior fossa group A (PFA) ependymoma is a lethal brain cancer diagnosed in infants and young children. The lack of driver events in the PFA linear genome led us to search its 3D genome for characteristic features. Here, we reconstructed 3D genomes from diverse childhood tumor types and uncovered a global topology in PFA that is highly reminiscent of stem and progenitor cells in a variety of human tissues. A remarkable feature exclusively present in PFA are type B ultra long-range interactions in PFAs (TULIPs), regions separated by great distances along the linear genome that interact with each other in the 3D nuclear space with surprising strength. TULIPs occur in all PFA samples and recur at predictable genomic coordinates, and their formation is induced by expression of EZHIP. The universality of TULIPs across PFA samples suggests a conservation of molecular principles that could be exploited therapeutically.

3.
Genome Res ; 34(3): 426-440, 2024 04 25.
Article in English | MEDLINE | ID: mdl-38621828

ABSTRACT

Genome structural variations within species are rare. How selective constraints preserve gene order and chromosome structure is a central question in evolutionary biology that remains unsolved. Our sequencing of several genomes of the appendicularian tunicate Oikopleura dioica around the globe reveals extreme genome scrambling caused by thousands of chromosomal rearrangements, although showing no obvious morphological differences between these animals. The breakpoint accumulation rate is an order of magnitude higher than in ascidian tunicates, nematodes, Drosophila, or mammals. Chromosome arms and sex-specific regions appear to be the primary unit of macrosynteny conservation. At the microsyntenic level, scrambling did not preserve operon structures, suggesting an absence of selective pressure to maintain them. The uncoupling of the genome scrambling with morphological conservation in O. dioica suggests the presence of previously unnoticed cryptic species and provides a new biological system that challenges our previous vision of speciation in which similar animals always share similar genome structures.


Subject(s)
Genome , Urochordata , Animals , Urochordata/genetics , Urochordata/classification , Evolution, Molecular , Female , Phylogeny , Male , Synteny
4.
Nat Commun ; 15(1): 2114, 2024 Mar 08.
Article in English | MEDLINE | ID: mdl-38459018

ABSTRACT

Remote sensing observations of Searles Lake following the 2019 moment magnitude 7.1 Ridgecrest, California, earthquake reveal an area where surface ejecta is arranged in a repeating hexagonal pattern that is collocated with a solution-mining operation. By analyzing geologic and geotechnical data, here we show that the hexagonal surface ejecta is likely not a result of liquefaction. Instead, we propose dissolution cavity collapse (DCC) as an alternative driving mechanism. We support this theory with pre-event Interferometric Synthetic Aperture Radar data, which reveals differential subsidence patterns and the creation of subsurface void space. We also find that DCC is likely triggered at a lower shaking threshold than classical liquefaction. This and other unknown mechanisms can masquerade as liquefaction, introducing bias into liquefaction prediction models that rely on liquefaction inventories. This paper also highlights the opportunities and drawbacks of using remote sensing data to disentangle the complex factors that influence earthquake-triggered ground failure.

5.
J Neurosurg Pediatr ; 33(4): 359-366, 2024 Apr 01.
Article in English | MEDLINE | ID: mdl-38215438

ABSTRACT

OBJECTIVE: Relatively little is known about the safety and accuracy of catheter placement for oncolytic viral therapy in children with malignant brain tumors. Accordingly, this study combines data from two phase I clinical trials that employed viral immunotherapy across two institutions to describe the adverse event profile, safety, and accuracy associated with the stereotactic placement and subsequent removal of intratumoral catheters. METHODS: Children with progressive/recurrent supratentorial malignant tumors were enrolled in two clinical trials (NCT03043391 and NCT02457845) and treated with either the recombinant polio:rhinovirus (lerapolturev) or the genetically modified oncolytic herpesvirus (G207). Age, sex, race, tumor diagnosis, and tumor location were analyzed. Events related to the catheter placement or removal were categorized. A catheter that was either pulled back or could not be used was defined as "misplaced." Neuronavigation software was used to analyze the accuracy of catheter placement for NCT03043391. Descriptive statistics were performed. RESULTS: Nineteen patients were treated across the two completed trials with a total of 49 catheters. The mean ± SD (range) age was 14.1 ± 3.6 (7-19) years. All tumors were grade 3 or 4 gliomas. Nonlobar catheter tip placement included the corpus callosum, thalamus, insula, and cingulate gyrus. Six of 19 patients (31.6%) had minor hemorrhage noted on CT; however, no patients were symptomatic and/or required intervention related to these findings. One of 19 patients had a delayed CSF leak after catheter removal that required oversewing of the surgical site. No patients developed infection or a neurological deficit. In 7 patients with accuracy data, the mean ± SD distance of the planned trajectory (PT) to the catheter tip was 1.57 ± 1.6 mm, the mean angle of the PT to the catheter was 2.43° ± 2.1°, and the greatest distance of PT to the catheter in the parallel plane was 1.54 ± 1.5 mm. Three of 49 (6.1%) catheters were considered misplaced. CONCLUSIONS: Although instances of minor hemorrhage were encountered, they were clinically asymptomatic. One of 49 catheters required intervention for a CSF leak. Congruent with previous studies in the literature, the stereotactic placement of catheters in these pediatric tumor patients was accurate with approximately 95% of catheters having been adequately placed.


Subject(s)
Brain Neoplasms , Neoplasm Recurrence, Local , Child , Humans , Adolescent , Neoplasm Recurrence, Local/therapy , Brain Neoplasms/diagnostic imaging , Brain Neoplasms/therapy , Catheters , Immunotherapy , Hemorrhage
6.
Transl Oncol ; 40: 101875, 2024 Feb.
Article in English | MEDLINE | ID: mdl-38183802

ABSTRACT

HSV G207, a double-stranded, DNA virus, and the polio:rhinovirus chimera, PVSRIPO, a single positive-strand RNA virus, are viral immunotherapies being used to treat pediatric malignant brain tumors in clinical trials. The purpose of this work is to elucidate general response patterns and putative biomarkers of response. Multiple pediatric high-grade glioma and medulloblastoma cell lines were treated with various multiplicities of infection of G207 or PVSRIPO. There was a significant inverse correlation between expression of one HSV cellular receptor, CD111, and the lethal dose of 50% of cells (LD50) of cells treated with G207 (r = -0.985, P<0.001) but no correlation between PVSRIPO cellular receptor expression (CD155) and LD50. RNA sequencing of control cells and cells treated for 8 and 24 h revealed that there were few shared differentially expressed (DE) genes between cells treated with PVSRIPO and G207: GCLM, LANCL2, and RBM3 were enriched whilst ADAMTS1 and VEGFA were depleted. Likewise, there were few shared DE genes enriched between medulloblastoma and high-grade glioma cell lines treated with G207: GPSM2, CHECK2, SEPTIN2, EIF4G2, GCLM, GDAP1, LANCL2, and PWP1.  Treatment with G207 and PVSRIPO appear to cause disparate gene enrichment and depletion suggesting disparate molecular mechanisms in malignant pediatric brain tumors.

7.
Glob Chang Biol ; 30(1): e17020, 2024 Jan.
Article in English | MEDLINE | ID: mdl-37947122

ABSTRACT

Gelatinous zooplankton are increasingly recognized to play a key role in the ocean's biological carbon pump. Appendicularians, a class of pelagic tunicates, are among the most abundant gelatinous plankton in the ocean, but it is an open question how their contribution to carbon export might change in the future. Here, we conducted an experiment with large volume in situ mesocosms (~55-60 m3 and 21 m depth) to investigate how ocean acidification (OA) extreme events affect food web structure and carbon export in a natural plankton community, particularly focusing on the keystone species Oikopleura dioica, a globally abundant appendicularian. We found a profound influence of O. dioica on vertical carbon fluxes, particularly during a short but intense bloom period in the high CO2 treatment, during which carbon export was 42%-64% higher than under ambient conditions. This elevated flux was mostly driven by an almost twofold increase in O. dioica biomass under high CO2 . This rapid population increase was linked to enhanced fecundity (+20%) that likely resulted from physiological benefits of low pH conditions. The resulting competitive advantage of O. dioica resulted in enhanced grazing on phytoplankton and transfer of this consumed biomass into sinking particles. Using a simple carbon flux model for O. dioica, we estimate that high CO2 doubled the carbon flux of discarded mucous houses and fecal pellets, accounting for up to 39% of total carbon export from the ecosystem during the bloom. Considering the wide geographic distribution of O. dioica, our findings suggest that appendicularians may become an increasingly important vector of carbon export with ongoing OA.


Subject(s)
Seawater , Urochordata , Animals , Seawater/chemistry , Ecosystem , Carbon Dioxide/chemistry , Carbon , Hydrogen-Ion Concentration , Plankton , Phytoplankton , Urochordata/physiology , Oceans and Seas
8.
Childs Nerv Syst ; 40(3): 673-684, 2024 Mar.
Article in English | MEDLINE | ID: mdl-37812266

ABSTRACT

PURPOSE: Intraventricular hemorrhage (IVH) of prematurity can lead to hydrocephalus, sometimes necessitating permanent cerebrospinal fluid (CSF) diversion. We sought to characterize the relationship between head circumference (HC) and ventricular size in IVH over time to evaluate the clinical utility of serial HC measurements as a metric in determining the need for CSF diversion. METHODS: We included preterm infants with IVH born between January 2000 and May 2020. Three measures of ventricular size were obtained: ventricular index (VI), Evan's ratio (ER), and frontal occipital head ratio (FOHR). The Pearson correlations (r) between the initial (at birth) paired measurements of HC and ventricular size were reported. Multivariable longitudinal regression models were fit to examine the HC:ventricle size ratio, adjusting for the age of the infant, IVH grade (I/II vs. III/IV), need for CSF diversion, and sex. RESULTS: A total of 639 patients with an average gestational age of 27.5 weeks were included. IVH grade I/II and grade III/IV patients had a positive correlation between initial HC and VI (r = 0.47, p < 0.001 and r = 0.48, p < 0.001, respectively). In our longitudinal models, patients with a low-grade IVH (I/II) had an HC:VI ratio 0.52 higher than those with a high-grade IVH (p-value < 0.001). Patients with low-grade IVH had an HC:ER ratio 12.94 higher than those with high-grade IVH (p-value < 0.001). Patients with low-grade IVH had a HC:FOHR ratio 12.91 higher than those with high-grade IVH (p-value < 0.001). Infants who did not require CSF diversion had an HC:VI ratio 0.47 higher than those who eventually did (p < 0.001). Infants without CSF diversion had an HC:ER ratio 16.53 higher than those who received CSF diversion (p < 0.001). Infants without CSF diversion had an HC:FOHR ratio 15.45 higher than those who received CSF diversion (95% CI (11.34, 19.56), p < 0.001). CONCLUSIONS: There is a significant difference in the ratio of HC:VI, HC:ER, and HC:FOHR size between patients with high-grade IVH and low-grade IVH. Likewise, there is a significant difference in HC:VI, HC:ER, and HC:FOHR between those who did and did not have CSF diversion. The routine assessments of both head circumference and ventricle size by ultrasound are important clinical tools in infants with IVH of prematurity.


Subject(s)
Hydrocephalus , Infant, Premature, Diseases , Infant , Infant, Newborn , Humans , Infant, Premature , Cerebral Ventricles/surgery , Hydrocephalus/surgery , Gestational Age , Infant, Premature, Diseases/surgery , Cerebral Hemorrhage/surgery , Retrospective Studies
9.
Front Cell Dev Biol ; 11: 1323378, 2023.
Article in English | MEDLINE | ID: mdl-38130951

ABSTRACT

A single Aurora kinase found in non-vertebrate deuterostomes is assumed to represent the ancestor of vertebrate Auroras A/B/C. However, the tunicate Oikopleura dioica, a member of the sister group to vertebrates, possesses two Aurora kinases (Aurora1 and Aurora2) that are expressed in proliferative cells and reproductive organs. Previously, we have shown that Aurora kinases relocate from organizing centers to meiotic nuclei and were enriched on centromeric regions as meiosis proceeds to metaphase I. Here, we assessed their respective functions in oogenic meiosis using dsRNA interferences. We found that Aurora1 (Aur1) was involved in meiotic spindle organization and chromosome congression, probably through the regulation of microtubule dynamics, whereas Aurora2 (Aur2) was crucial for chromosome condensation and meiotic spindle assembly. In vitro kinase assays showed that Aur1 and Aur2 had comparable levels of kinase activities. Using yeast two-hybrid library screening, we identified a few novel interaction proteins for Aur1, including c-Jun-amino-terminal kinase-interacting protein 4, cohesin loader Scc2, and mitochondrial carrier homolog 2, suggesting that Aur1 may have an altered interaction network and participate in the regulation of microtubule motors and cohesin complexes in O. dioica.

10.
Gels ; 9(10)2023 Oct 12.
Article in English | MEDLINE | ID: mdl-37888386

ABSTRACT

Autologous fat grafting is hampered by unpredictable outcomes due to high tissue resorption. Hydrogels based on enzymatically pretreated tunicate nanocellulose (ETC) and alginate (ALG) are biocompatible, safe, and present physiochemical properties capable of promoting cell survival. Here, we compared in situ and ex situ crosslinking of ETC/ALG hydrogels combined with lipoaspirate human adipose tissue (LAT) to generate an injectable formulation capable of retaining dimensional stability in vivo. We performed in situ crosslinking using two different approaches; inducing Ca2+ release from CaCO3 microparticles (CMPs) and physiologically available Ca2+ in vivo. Additionally, we generated ex situ-crosslinked, 3D-bioprinted hydrogel-fat grafts. We found that in vitro optimization generated a CMP-crosslinking system with comparable stiffness to ex situ-crosslinked gels. Comparison of outcomes following in vivo injection of each respective crosslinked hydrogel revealed that after 30 days, in situ crosslinking generated fat grafts with less shape retention than 3D-bioprinted constructs that had undergone ex situ crosslinking. However, CMP addition improved fat-cell distribution and cell survival relative to grafts dependent on physiological Ca2+ alone. These findings suggested that in situ crosslinking using CMP might promote the dimensional stability of injectable fat-hydrogel grafts, although 3D bioprinting with ex situ crosslinking more effectively ensured proper shape stability in vivo.

11.
Neurooncol Adv ; 5(1): vdad095, 2023.
Article in English | MEDLINE | ID: mdl-37781087

ABSTRACT

Background: Medulloblastoma is the most common malignant pediatric brain tumor, and leptomeningeal dissemination (LMD) of medulloblastoma both portends a poorer prognosis at diagnosis and is incurable at recurrence. The biological mechanisms underlying LMD are unclear. The Abelson (ABL) tyrosine kinase family members, ABL1 and ABL2, have been implicated in cancer cell migration, invasion, adhesion, metastasis, and chemotherapy resistance, and are upstream mediators of the oncogene c-MYC in fibroblasts and lung cancer cells. However, their role in medulloblastoma has not yet been explored. The purpose of this work was to elucidate the role of ABL1/2 in medulloblastoma LMD. Methods: ABL1 and ABL2 mRNA expression of patient specimens was analyzed. shRNA knockdowns of ABL1/2 and pharmacologic inhibition of ABL1/2 were used for in vitro and in vivo analyses of medulloblastoma LMD. RNA sequencing of ABL1/2 genetic knockdown versus scrambled control medulloblastoma was completed. Results: ABL1/2 mRNA is highly expressed in human medulloblastoma and pharmacologic inhibition of ABL kinases resulted in cytotoxicity. Knockdown of ABL1/2 resulted in decreased adhesion of medulloblastoma cells to the extracellular matrix protein, vitronectin (P = .0013), and significantly decreased tumor burden in a mouse model of medulloblastoma LMD with improved overall survival (P = .0044). Furthermore, both pharmacologic inhibition of ABL1/2 and ABL1/2 knockdown resulted in decreased expression of c-MYC, identifying a putative signaling pathway, and genes/pathways related to oncogenesis and neurodevelopment were differentially expressed between ABL1/2 knockdown and control medulloblastoma cells. Conclusions: ABL1 and ABL2 have potential roles in medulloblastoma LMD upstream of c-MYC expression.

12.
Lancet Child Adolesc Health ; 7(7): 471-478, 2023 07.
Article in English | MEDLINE | ID: mdl-37004712

ABSTRACT

BACKGROUND: Outcomes of recurrent paediatric high-grade glioma are poor, with a median overall survival of less than 6 months. Viral immunotherapy, such as the polio-rhinovirus chimera lerapolturev, is a novel approach for treatment of recurrent paediatric high-grade glioma and has shown promise in adults with recurrent glioblastoma. The poliovirus receptor CD155 is ubiquitously expressed in malignant paediatric brain tumours and is a treatment target in paediatric high-grade glioma. We aimed to assess the safety of lerapolturev when administered as a single dose intracerebrally by convection enhanced delivery in children and young people with recurrent WHO grade 3 or grade 4 glioma, and to assess overall survival in these patients. METHODS: This phase 1b trial was done at the Duke University Medical Center (Durham, NC, USA). Patients aged 4-21 years with recurrent high-grade malignant glioma (anaplastic astrocytoma, glioblastoma, anaplastic oligoastrocytoma, anaplastic oligodendroglioma, or anaplastic pleomorphic xanthoastrocytoma) or anaplastic ependymoma, atypical teratoid rhabdoid tumour, or medulloblastoma with infusible disease were eligible for this study. A catheter was tunnelled beneath the scalp for a distance of at least 5 cm to aid in prevention of infection. The next day, lerapolturev at a dose of 5 × 107 median tissue culture infectious dose in 3 mL infusate loaded in a syringe was administered via a pump at a rate of 0·5 mL per h as a one-time dose. The infusion time was approximately 6·5 h to compensate for volume of the tubing. The primary endpoint was the proportion of patients with unacceptable toxic effects during the 14-day period after lerapolturev treatment. The study is registered with ClinicalTrials.gov, NCT03043391. FINDINGS: Between Dec 5, 2017, and May 12, 2021, 12 patients (11 unique patients) were enrolled in the trial. Eight patients were treated with lerapolturev. The median patient age was 16·5 years (IQR 11·0-18·0), five (63%) of eight patients were male and three (38%) were female, and six (75%) of eight patients were White and two (25%) were Black or African American. The median number of previous chemotherapeutic regimens was 3·50 (IQR 1·25-5·00). Six of eight patients had 26 treatment-related adverse events attributable to lerapolturev. There were no irreversible (ie, persisted longer than 2 weeks) treatment-related grade 4 adverse events or deaths. Treatment-related grade 3 adverse events included headaches in two patients and seizure in one patient. Four patients received low-dose bevacizumab on-study for treatment-related peritumoural inflammation or oedema, diagnosed by both clinical symptoms plus fluid-attenuated inversion recovery MRI. The median overall survival was 4·1 months (95% CI 1·2-10·1). One patient remains alive after 22 months. INTERPRETATION: Convection enhanced delivery of lerapolturev is safe enough in the treatment of recurrent paediatric high-grade glioma to proceed to the next phase of trial. FUNDING: Solving Kids Cancer, B+ Foundation, Musella Foundation, and National Institutes of Health.


Subject(s)
Astrocytoma , Brain Neoplasms , Cerebellar Neoplasms , Glioblastoma , Glioma , Poliomyelitis , Adult , Humans , Child , Male , Female , Adolescent , Rhinovirus , Neoplasm Recurrence, Local/therapy , Glioma/drug therapy , Brain Neoplasms/therapy , Immunotherapy
13.
J Neurosurg Pediatr ; : 1-14, 2023 Mar 03.
Article in English | MEDLINE | ID: mdl-36883640

ABSTRACT

OBJECTIVE: The authors of this study evaluated the safety and efficacy of stereotactic laser ablation (SLA) for the treatment of drug-resistant epilepsy (DRE) in children. METHODS: Seventeen North American centers were enrolled in the study. Data for pediatric patients with DRE who had been treated with SLA between 2008 and 2018 were retrospectively reviewed. RESULTS: A total of 225 patients, mean age 12.8 ± 5.8 years, were identified. Target-of-interest (TOI) locations included extratemporal (44.4%), temporal neocortical (8.4%), mesiotemporal (23.1%), hypothalamic (14.2%), and callosal (9.8%). Visualase and NeuroBlate SLA systems were used in 199 and 26 cases, respectively. Procedure goals included ablation (149 cases), disconnection (63), or both (13). The mean follow-up was 27 ± 20.4 months. Improvement in targeted seizure type (TST) was seen in 179 (84.0%) patients. Engel classification was reported for 167 (74.2%) patients; excluding the palliative cases, 74 (49.7%), 35 (23.5%), 10 (6.7%), and 30 (20.1%) patients had Engel class I, II, III, and IV outcomes, respectively. For patients with a follow-up ≥ 12 months, 25 (51.0%), 18 (36.7%), 3 (6.1%), and 3 (6.1%) had Engel class I, II, III, and IV outcomes, respectively. Patients with a history of pre-SLA surgery related to the TOI, a pathology of malformation of cortical development, and 2+ trajectories per TOI were more likely to experience no improvement in seizure frequency and/or to have an unfavorable outcome. A greater number of smaller thermal lesions was associated with greater improvement in TST. Thirty (13.3%) patients experienced 51 short-term complications including malpositioned catheter (3 cases), intracranial hemorrhage (2), transient neurological deficit (19), permanent neurological deficit (3), symptomatic perilesional edema (6), hydrocephalus (1), CSF leakage (1), wound infection (2), unplanned ICU stay (5), and unplanned 30-day readmission (9). The relative incidence of complications was higher in the hypothalamic target location. Target volume, number of laser trajectories, number or size of thermal lesions, or use of perioperative steroids did not have a significant effect on short-term complications. CONCLUSIONS: SLA appears to be an effective and well-tolerated treatment option for children with DRE. Large-volume prospective studies are needed to better understand the indications for treatment and demonstrate the long-term efficacy of SLA in this population.

14.
Acta Neuropathol Commun ; 11(1): 50, 2023 03 25.
Article in English | MEDLINE | ID: mdl-36966348

ABSTRACT

Gangliogliomas are brain tumors composed of neuron-like and macroglia-like components that occur in children and young adults. Gangliogliomas are often characterized by a rare population of immature astrocyte-appearing cells expressing CD34, a marker expressed in the neuroectoderm (neural precursor cells) during embryogenesis. New insights are needed to refine tumor classification and to identify therapeutic approaches. We evaluated five gangliogliomas with single nucleus RNA-seq, cellular indexing of transcriptomes and epitopes by sequencing, and/or spatially-resolved RNA-seq. We uncovered a population of CD34+ neoplastic cells with mixed neuroectodermal, immature astrocyte, and neuronal markers. Gene regulatory network interrogation in these neuroectoderm-like cells revealed control of transcriptional programming by TCF7L2/MEIS1-PAX6 and SOX2, similar to that found during neuroectodermal/neural development. Developmental trajectory analyses place neuroectoderm-like tumor cells as precursor cells that give rise to neuron-like and macroglia-like neoplastic cells. Spatially-resolved transcriptomics revealed a neuroectoderm-like tumor cell niche with relative lack of vascular and immune cells. We used these high resolution results to deconvolute clinically-annotated transcriptomic data, confirming that CD34+ cell-associated gene programs associate with gangliogliomas compared to other glial brain tumors. Together, these deep transcriptomic approaches characterized a ganglioglioma cellular hierarchy-confirming CD34+ neuroectoderm-like tumor precursor cells, controlling transcription programs, cell signaling, and associated immune cell states. These findings may guide tumor classification, diagnosis, prognostication, and therapeutic investigations.


Subject(s)
Brain Neoplasms , Ganglioglioma , Neural Stem Cells , Child , Humans , Ganglioglioma/pathology , Transcriptome , Neural Plate/pathology , Neural Stem Cells/pathology , Brain Neoplasms/pathology
15.
Biomater Adv ; 137: 212828, 2022 Jun.
Article in English | MEDLINE | ID: mdl-35929261

ABSTRACT

Extracellular matrix fibril components, such as collagen, are crucial for the structural properties of several tissues and organs. Tunicate-derived cellulose nanofibrils (TNC) combined with living cells could become the next gold standard for cartilage and soft-tissue repair, as TNC fibrils present similar dimensions to collagen, feasible industrial production, and chemically straightforward and cost-efficient extraction procedures. In this study, we characterized the physical properties of TNC derived from aquaculture production in Norwegian fjords and evaluated its biocompatibility regarding induction of an inflammatory response and foreign-body reactions in a Wistar rat model. Additionally, histologic and immunohistochemical analyses were performed for comparison with expanded polytetrafluoroethylene (ePTFE) as a control. The average length of the TNC as determined by atomic force microscopy was tunable from 3 µm to 2.4 µm via selection of a various number of passages through a microfluidizer, and rheologic analysis showed that the TNC hydrogels were highly shear-thinning and with a viscosity dependent on fibril length and concentration. As a bioink, TNC exhibited excellent rheological and printability properties, with constructs capable of being printed with high resolution and fidelity. We found that post-print cross-linking with alginate stabilized the construct shape and texture, which increased its ease of handling during surgery. Moreover, after 30 days in vivo, the constructs showed a highly-preserved shape and fidelity of the grid holes, with these characteristics preserved after 90 days and with no signs of necrosis, infection, acute inflammation, invasion of neutrophil granulocytes, or extensive fibrosis. Furthermore, we observed a moderate foreign-body reaction involving macrophages, lymphocytes, and giant cells in both the TNC constructs and PTFE controls, although TNC was considered a non-irritant biomaterial according to ISO 10993-6 as compared with ePTFE. These findings represent a milestone for future clinical application of TNC scaffolds for tissue repair. One sentence summary: In this study, the mechanical properties of tunicate nanocellulose are superior to nanocellulose extracted from other sources, and the biocompatibility is comparable to that of ePTFE.


Subject(s)
Tissue Engineering , Urochordata , Animals , Biocompatible Materials/chemistry , Cellulose/pharmacology , Collagen/pharmacology , Rats , Rats, Wistar , Tissue Engineering/methods
16.
Pediatr Neurosurg ; 57(4): 295-300, 2022.
Article in English | MEDLINE | ID: mdl-35512661

ABSTRACT

INTRODUCTION: Intraoperative neuromonitoring (IONM) is commonly used during surgery of the spine and spinal cord for early surveillance of iatrogenic injury to the central and peripheral nervous system. However, for infants and young children under 3 years of age, the use of IONM is challenging due to incomplete central and peripheral myelination. CASE PRESENTATION: We report a case of a T4-T6 dermal sinus tract (DST) that was resected on day of life 23, with the successful use of IONM. CONCLUSION: To our knowledge, this is the youngest reported case of the use of IONM in the surgical correction of a DST in a neonatal patient. This case demonstrates the potential efficacy of IONM in neonatal spine surgery and the techniques used to adapt the technology to an immature nervous system.


Subject(s)
Fistula , Intraoperative Neurophysiological Monitoring , Spina Bifida Occulta , Child , Child, Preschool , Evoked Potentials, Motor/physiology , Humans , Infant , Infant, Newborn , Intraoperative Neurophysiological Monitoring/methods , Neurosurgical Procedures/methods , Retrospective Studies , Spina Bifida Occulta/diagnostic imaging , Spina Bifida Occulta/surgery , Spine
17.
Oncogene ; 41(19): 2663-2671, 2022 05.
Article in English | MEDLINE | ID: mdl-35430605

ABSTRACT

Brain tumors result in significant morbidity and mortality in both children and adults. Recent data indicate that immunotherapies may offer a survival benefit after standard of care has failed for malignant brain tumors. Modest results from several late phase clinical trials, however, underscore the need for more refined, comprehensive strategies that incorporate new mechanistic and pharmacologic knowledge. Recently, oncometabolism has emerged as an adjunct modality for combinatorial treatment approaches necessitated by the aggressive, refractory nature of high-grade glioma and other progressive malignant brain tumors. Manipulation of metabolic processes in cancer and immune cells that comprise the tumor microenvironment through controlled targeting of oncogenic pathways may be utilized to maximize the efficacy of immunotherapy and improve patient outcomes. Herein, we summarize preclinical and early phase clinical trial research of oncometabolism-based therapeutics that may augment immunotherapy by exploiting the biochemical and genetic underpinnings of brain tumors. We also examine metabolic pathways related to immune cells that target tumor cells, termed "tumor immunometabolism". Specifically, we focus on glycolysis and altered glucose metabolism, including glucose transporters, hexokinase, pyruvate dehydrogenase, and lactate dehydrogenase, glutamine, and we discuss targeting arginase, adenosine, and indoleamine 2,3-dioxygenase, and toll-like receptors. Lastly, we summarize future directions targeting metabolism in combination with emerging therapies such as oncolytic virotherapy, vaccines, and chimeric antigen receptor T cells.


Subject(s)
Brain Neoplasms , Glioma , Oncolytic Virotherapy , Adult , Brain Neoplasms/genetics , Child , Glioma/therapy , Humans , Immunotherapy/methods , Oncolytic Virotherapy/methods , Tumor Microenvironment
18.
Carbohydr Polym ; 286: 119284, 2022 Jun 15.
Article in English | MEDLINE | ID: mdl-35337506

ABSTRACT

Alginate has been used for decades for cell encapsulation. Cellulose nanofibrils (CNF) from tunicates are desirable in biomedicine due to high molecular weight, purity, crystallinity, and sustainable production. We prepared microbeads of 400-600 µm of alginate and tunicate CNF. Greater size, dispersity and aspect ratio were observed in microbeads with higher fractions of CNF. CNF content in Ca-crosslinked alginate microbeads decreased stability upon saline exposure, whereas crosslinking with calcium (50 mM) and barium (1 mM) yielded stable microbeads. The Young's moduli of gel cylinders decreased when exchanging alginate with CNF, and slightly increased permeability to dextran was observed in microbeads containing CNF. Encapsulation of MC3T3 cells revealed high cell viability after encapsulation (83.6 ± 0.4%) in beads of alginate and CNF. NHDFs showed lower viability but optimizing mixing and production techniques of microbeads increased cell viability (from 66.2 ± 5.3% to 72.7 ± 7.5%).


Subject(s)
Alginates , Urochordata , Animals , Cell Encapsulation , Cellulose/pharmacology , Microspheres
19.
J Craniofac Surg ; 33(5): 1327-1330, 2022.
Article in English | MEDLINE | ID: mdl-34930880

ABSTRACT

ABSTRACT: Blood loss is a main cause of morbidity after craniofacial procedures. The purpose of this study is to identify the incidence and predictors for transfusion of blood products in the endoscopic assisted strip craniectomy population. Data was prospectively collected from a single-center multi-surgeon cohort of 78 consecutive patients who underwent endoscopic assisted strip craniectomy for craniosynostosis between July 2013 and December 2020. The authors reviewed patient and treatment characteristics and outcomes. Of the 78 patients, 26 patients were transfused yielding an overall rate of transfusion of 33%. The most common fused suture was sagittal (n = 42, 54%) followed by metopic (n = 15, 19%), multiple (n = 10, 13%), coronal (n = 7, 9%) and finally lambdoid (n = 4, 5%). On univariate analysis, patients' weight in the transfusion cohort were significantly lower than those who did not receive a transfusion (5.6 ± 1.1 versus 6.5 ± 1.1 kg, P = 0.0008). The transfusion group also had significantly lower preoperative hemoglobin compared to the non-transfusion group (10.6 versus 11.1, P = .049). Eleven percent patients admitted to step-down received a transfusion, whereas 39% of patients admitted to the pediatric intensive care unit received a transfusion ( P = 0.042). On multivariate analysis, only higher patient weight (operating room [OR] 0.305 [0.134, 0.693], P = 0.005) was protective against a transfusion, whereas colloid volume (OR 1.018 [1.003, 1.033], P = 0.019) predicted the need for a transfusion.Our results demonstrate that endoscopic craniosynostosis cases carry a moderate risk of transfusion. individuals with lower weight and those that receive colloid volume are also at elevated risk.


Subject(s)
Craniosynostoses , Blood Loss, Surgical , Blood Transfusion/methods , Child , Craniosynostoses/epidemiology , Craniotomy/methods , Endoscopy/methods , Humans , Infant , Neurosurgical Procedures , Retrospective Studies , Treatment Outcome
20.
Transl Pediatr ; 11(12): 2040-2056, 2022 Dec.
Article in English | MEDLINE | ID: mdl-36643672

ABSTRACT

Background and Objective: The goal of this narrative review is to report and summarize the completed pediatric immunotherapy clinical trials for primary CNS tumors. Pediatric central nervous system (CNS) tumors are the most common cause of pediatric solid cancer in children aged 0 to 14 years and the leading cause of cancer mortality. Survival rates for some pediatric brain tumors have improved, however, there remains a large portion of pediatric brain tumors with poor survival outcomes despite advances in treatment. Cancer immunotherapy is a growing field that has shown promise in the treatment of pediatric brain tumors that have historically shown a poor response to treatment. This narrative review provides a summary and discussion of the published literature focused on treating pediatric brain tumors with immunotherapy. Methods: MEDLINE via PubMed, Embase and Scopus via Elsevier were searched. The search utilized a combination of keywords and subject headings to include pediatrics, brain tumors, and immunotherapies. Manuscripts included in the analysis included completed clinical studies using any immunotherapy intervention with a patient population that consisted of at least half pediatric patients (<18 years) with primary CNS tumors. Conference abstracts were excluded as well as studies that did not include completed safety or primary outcome results. Key Content and Findings: Search results returned 1,494 articles. Screening titles and abstracts resulted in 180 articles for full text review. Of the 180 articles, 18 were included for analysis. Another two articles were ultimately included after review of references and inclusion of newly published articles, for a total of 20 included articles. Immunotherapies included dendritic cell vaccines, oncolytic virotherapy/viral immunotherapy, chimeric antigen receptor (CAR) T-cell therapy, peptide vaccines, immunomodulatory agents, and others. Conclusions: In this review, 20 published articles were highlighted which use immunotherapy in the treatment of primary pediatric brain tumors. To date, most of the studies published utilizing immunotherapy were phase I and pilot studies focused primarily on establishing safety and maximum dose-tolerance and toxicity while monitoring survival endpoints. With established efficacy and toxicity profiles, future trials may progress to further understanding the overall survival and quality of life benefits to pediatric patients with primary brain tumors.

SELECTION OF CITATIONS
SEARCH DETAIL