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1.
Heliyon ; 9(10): e21133, 2023 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-37916073

RESUMO

Ecosystem degradation and fossil fuel depletion are the two foremost concerns to look for alternative fuels. Rapid population growth is primarily accountable for higher consumption of fossil fuel sources, although engine technology is achieving milestones in terms of fuel efficiency and lower exhaust emissions in order to contribute towards a sustainable environment. The main root cause of global warming is carbon dioxide emissions; therefore, it is imperative to assess the impact of alternative fuels in diesel engines with an aim to minimize carbon emissions. A current study deals with the reduction of carbon emissions and improvement of efficiency through addition of manganese nano-additive to di-ethyl ether and diesel fuel blend in particulate form. Fuel blends were formed by adding various proportions of manganese to high-speed diesel fuel and stirring the mixture while heating it for 10 min. The blends were then tested in diesel engines at two distinct loads and five engine speed ranges. Emission analyzer was used to ascertain the CO2 output of engine. At higher loads for 10 % diethyl ether in diesel, the increase in brake thermal efficiency was 24.19, 28.17 and 26.86 % when the manganese amount in blend was changed as 250 mg, 375 mg and 500 mg respectively. On the other side CO2 emissions increase by 11.57, 30.52 and 20.33 % for manganese concentrations of 250 mg, 375 mg and 500 mg respectively. Analysis performed with Design Expert 13 showed that the desirability was 0.796 for a blend of 375 mg manganese at 1300 rpm and 4500 W load with 33.0611 % BTE, 334.011kg/kWh BSFC, 67.8821Nm torque, and 6.072 % CO2. Therefore, it can be deduced that manganese nanoparticle blends improved engine performance but CO2 emissions also increase which can be responsible for global warming and it should be reduced through catalytic converters.

2.
Front Oncol ; 13: 1221611, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37576901

RESUMO

Introduction: Medulloblastoma is the most common type of malignant pediatric brain tumor with group 4 medulloblastomas (G4 MBs) accounting for 40% of cases. However, the molecular mechanisms that underlie this subgroup are still poorly understood. Point mutations are detected in a large number of genes at low incidence per gene while the detection of complex structural variants in recurrently affected genes typically requires the application of long-read technologies. Methods: Here, we applied linked-read sequencing, which combines the long-range genome information of long-read sequencing with the high base pair accuracy of short read sequencing and very low sample input requirements. Results: We demonstrate the detection of complex structural variants and point mutations in these tumors, and, for the first time, the detection of extrachromosomal DNA (ecDNA) with linked-reads. We provide further evidence for the high heterogeneity of somatic mutations in G4 MBs and add new complex events associated with it. Discussion: We detected several enhancer-hijacking events, an ecDNA containing the MYCN gene, and rare structural rearrangements, such a chromothripsis in a G4 medulloblastoma, chromoplexy involving 8 different chromosomes, a TERT gene rearrangement, and a PRDM6 duplication.

3.
Sensors (Basel) ; 23(12)2023 Jun 07.
Artigo em Inglês | MEDLINE | ID: mdl-37420557

RESUMO

Traffic accidents present significant risks to human life, leading to a high number of fatalities and injuries. According to the World Health Organization's 2022 worldwide status report on road safety, there were 27,582 deaths linked to traffic-related events, including 4448 fatalities at the collision scenes. Drunk driving is one of the leading causes contributing to the rising count of deadly accidents. Current methods to assess driver alcohol consumption are vulnerable to network risks, such as data corruption, identity theft, and man-in-the-middle attacks. In addition, these systems are subject to security restrictions that have been largely overlooked in earlier research focused on driver information. This study intends to develop a platform that combines the Internet of Things (IoT) with blockchain technology in order to address these concerns and improve the security of user data. In this work, we present a device- and blockchain-based dashboard solution for a centralized police monitoring account. The equipment is responsible for determining the driver's impairment level by monitoring the driver's blood alcohol concentration (BAC) and the stability of the vehicle. At predetermined times, integrated blockchain transactions are executed, transmitting data straight to the central police account. This eliminates the need for a central server, ensuring the immutability of data and the existence of blockchain transactions that are independent of any central authority. Our system delivers scalability, compatibility, and faster execution times by adopting this approach. Through comparative research, we have identified a significant increase in the need for security measures in relevant scenarios, highlighting the importance of our suggested model.


Assuntos
Blockchain , Dirigir sob a Influência , Internet das Coisas , Humanos , Acidentes de Trânsito/prevenção & controle , Concentração Alcoólica no Sangue
5.
Nature ; 609(7929): 1021-1028, 2022 09.
Artigo em Inglês | MEDLINE | ID: mdl-36131014

RESUMO

Medulloblastoma (MB) comprises a group of heterogeneous paediatric embryonal neoplasms of the hindbrain with strong links to early development of the hindbrain1-4. Mutations that activate Sonic hedgehog signalling lead to Sonic hedgehog MB in the upper rhombic lip (RL) granule cell lineage5-8. By contrast, mutations that activate WNT signalling lead to WNT MB in the lower RL9,10. However, little is known about the more commonly occurring group 4 (G4) MB, which is thought to arise in the unipolar brush cell lineage3,4. Here we demonstrate that somatic mutations that cause G4 MB converge on the core binding factor alpha (CBFA) complex and mutually exclusive alterations that affect CBFA2T2, CBFA2T3, PRDM6, UTX and OTX2. CBFA2T2 is expressed early in the progenitor cells of the cerebellar RL subventricular zone in Homo sapiens, and G4 MB transcriptionally resembles these progenitors but are stalled in developmental time. Knockdown of OTX2 in model systems relieves this differentiation blockade, which allows MB cells to spontaneously proceed along normal developmental differentiation trajectories. The specific nature of the split human RL, which is destined to generate most of the neurons in the human brain, and its high level of susceptible EOMES+KI67+ unipolar brush cell progenitor cells probably predisposes our species to the development of G4 MB.


Assuntos
Diferenciação Celular , Neoplasias Cerebelares , Meduloblastoma , Metencéfalo , Diferenciação Celular/genética , Linhagem da Célula , Neoplasias Cerebelares/classificação , Neoplasias Cerebelares/genética , Neoplasias Cerebelares/patologia , Cerebelo/embriologia , Cerebelo/patologia , Subunidades alfa de Fatores de Ligação ao Core/genética , Proteínas Hedgehog/metabolismo , Histona Desmetilases , Humanos , Antígeno Ki-67/metabolismo , Meduloblastoma/classificação , Meduloblastoma/genética , Meduloblastoma/patologia , Metencéfalo/embriologia , Metencéfalo/patologia , Proteínas Musculares , Mutação , Fatores de Transcrição Otx/deficiência , Fatores de Transcrição Otx/genética , Proteínas Repressoras , Proteínas com Domínio T/metabolismo , Fatores de Transcrição
7.
Nat Commun ; 12(1): 1749, 2021 03 19.
Artigo em Inglês | MEDLINE | ID: mdl-33741928

RESUMO

Sonic hedgehog medulloblastoma encompasses a clinically and molecularly diverse group of cancers of the developing central nervous system. Here, we use unbiased sequencing of the transcriptome across a large cohort of 250 tumors to reveal differences among molecular subtypes of the disease, and demonstrate the previously unappreciated importance of non-coding RNA transcripts. We identify alterations within the cAMP dependent pathway (GNAS, PRKAR1A) which converge on GLI2 activity and show that 18% of tumors have a genetic event that directly targets the abundance and/or stability of MYCN. Furthermore, we discover an extensive network of fusions in focally amplified regions encompassing GLI2, and several loss-of-function fusions in tumor suppressor genes PTCH1, SUFU and NCOR1. Molecular convergence on a subset of genes by nucleotide variants, copy number aberrations, and gene fusions highlight the key roles of specific pathways in the pathogenesis of Sonic hedgehog medulloblastoma and open up opportunities for therapeutic intervention.


Assuntos
Neoplasias Cerebelares/genética , Regulação Neoplásica da Expressão Gênica , Proteínas Hedgehog/genética , Meduloblastoma/genética , Transcriptoma , Adolescente , Adulto , Criança , Pré-Escolar , Feminino , Redes Reguladoras de Genes , Variação Genética , Humanos , Lactente , Masculino , Pessoa de Meia-Idade , Transdução de Sinais/genética , Adulto Jovem
8.
Front Neurol ; 11: 606478, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33329369

RESUMO

The robustness of brain structural networks, estimated from diffusion MRI data, may be relevant to cognition. We investigate whether measures of network robustness, such as Ollivier-Ricci curvature, can explain cognitive impairment in multiple sclerosis (MS). We assessed whether local (i.e., cortical area) and/or global (i.e., whole brain) robustness, differs between cognitively impaired (MSCI) and non-impaired (MSNI) MS patients. Fifty patients, with Expanded Disability Status Scale mean (m): 3.2, disease duration m: 12 years, and age m: 40 years, were enrolled. Cognitive impairment scores were estimated from the Minimal Assessment of Cognitive Function in Multiple Sclerosis. Images were obtained in a 3T MRI using a diffusion protocol with a 2 min acquisition time. Brain structural networks were created using 333 cortical areas. Local and global robustness was estimated for each individual, and comparisons were performed between MSCI and MSNI patients. 31 MSCI and 10 MSNI patients were included in the analyses. Brain structural network robustness and centrality showed significant correlations with cognitive impairment. Measures of network robustness and centrality identified specific cortical areas relevant to MS-related cognitive impairment. These measures can be obtained on clinical scanners and are succinct yet accurate potential biomarkers of cognitive impairment.

9.
Nat Neurosci ; 23(7): 842-853, 2020 07.
Artigo em Inglês | MEDLINE | ID: mdl-32424282

RESUMO

Many immunotherapies act by enhancing the ability of cytotoxic T cells to kill tumor cells. Killing depends on T cell recognition of antigens presented by class I major histocompatibility complex (MHC-I) proteins on tumor cells. In this study, we showed that medulloblastomas lacking the p53 tumor suppressor do not express surface MHC-I and are therefore resistant to immune rejection. Mechanistically, this is because p53 regulates expression of the peptide transporter Tap1 and the aminopeptidase Erap1, which are required for MHC-I trafficking to the cell surface. In vitro, tumor necrosis factor (TNF) or lymphotoxin-ß receptor agonist can rescue expression of Erap1, Tap1 and MHC-I on p53-mutant tumor cells. In vivo, low doses of TNF prolong survival and synergize with immune checkpoint inhibitors to promote tumor rejection. These studies identified p53 as a key regulator of immune evasion and suggest that TNF could be used to enhance sensitivity of tumors to immunotherapy.


Assuntos
Neoplasias Cerebelares/imunologia , Meduloblastoma/imunologia , Evasão Tumoral/imunologia , Fator de Necrose Tumoral alfa/imunologia , Proteína Supressora de Tumor p53/imunologia , Animais , Neoplasias Cerebelares/genética , Neoplasias Cerebelares/metabolismo , Meduloblastoma/genética , Meduloblastoma/metabolismo , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Endogâmicos NOD , Camundongos SCID , Transplante de Neoplasias , Fator de Necrose Tumoral alfa/metabolismo , Proteína Supressora de Tumor p53/genética , Proteína Supressora de Tumor p53/metabolismo
10.
Cell ; 181(6): 1329-1345.e24, 2020 06 11.
Artigo em Inglês | MEDLINE | ID: mdl-32445698

RESUMO

Posterior fossa A (PFA) ependymomas are lethal malignancies of the hindbrain in infants and toddlers. Lacking highly recurrent somatic mutations, PFA ependymomas are proposed to be epigenetically driven tumors for which model systems are lacking. Here we demonstrate that PFA ependymomas are maintained under hypoxia, associated with restricted availability of specific metabolites to diminish histone methylation, and increase histone demethylation and acetylation at histone 3 lysine 27 (H3K27). PFA ependymomas initiate from a cell lineage in the first trimester of human development that resides in restricted oxygen. Unlike other ependymomas, transient exposure of PFA cells to ambient oxygen induces irreversible cellular toxicity. PFA tumors exhibit a low basal level of H3K27me3, and, paradoxically, inhibition of H3K27 methylation specifically disrupts PFA tumor growth. Targeting metabolism and/or the epigenome presents a unique opportunity for rational therapy for infants with PFA ependymoma.


Assuntos
Ependimoma/genética , Ependimoma/metabolismo , Epigenoma/genética , Neoplasias Infratentoriais/genética , Neoplasias Infratentoriais/metabolismo , Animais , Neoplasias Encefálicas/genética , Neoplasias Encefálicas/metabolismo , Linhagem Celular , Proliferação de Células/genética , Metilação de DNA/genética , Epigenômica/métodos , Histonas/genética , Histonas/metabolismo , Humanos , Lactente , Lisina/genética , Lisina/metabolismo , Masculino , Camundongos Endogâmicos C57BL , Mutação/genética
12.
Nat Commun ; 10(1): 4937, 2019 10 30.
Artigo em Inglês | MEDLINE | ID: mdl-31666510

RESUMO

Although brain functionality is often remarkably robust to lesions and other insults, it may be fragile when these take place in specific locations. Previous attempts to quantify robustness and fragility sought to understand how the functional connectivity of brain networks is affected by structural changes, using either model-based predictions or empirical studies of the effects of lesions. We advance a geometric viewpoint relying on a notion of network curvature, the so-called Ollivier-Ricci curvature. This approach has been proposed to assess financial market robustness and to differentiate biological networks of cancer cells from healthy ones. Here, we apply curvature-based measures to brain structural networks to identify robust and fragile brain regions in healthy subjects. We show that curvature can also be used to track changes in brain connectivity related to age and autism spectrum disorder (ASD), and we obtain results that are in agreement with previous MRI studies.


Assuntos
Envelhecimento/fisiologia , Encéfalo/diagnóstico por imagem , Vias Neurais/diagnóstico por imagem , Adolescente , Adulto , Idoso , Transtorno do Espectro Autista/diagnóstico por imagem , Transtorno do Espectro Autista/fisiopatologia , Encéfalo/fisiologia , Encéfalo/fisiopatologia , Criança , Pré-Escolar , Imagem de Difusão por Ressonância Magnética , Feminino , Humanos , Imageamento por Ressonância Magnética , Masculino , Pessoa de Meia-Idade , Modelos Teóricos , Vias Neurais/fisiologia , Vias Neurais/fisiopatologia , Adulto Jovem
13.
Nature ; 574(7780): 707-711, 2019 10.
Artigo em Inglês | MEDLINE | ID: mdl-31664194

RESUMO

In cancer, recurrent somatic single-nucleotide variants-which are rare in most paediatric cancers-are confined largely to protein-coding genes1-3. Here we report highly recurrent hotspot mutations (r.3A>G) of U1 spliceosomal small nuclear RNAs (snRNAs) in about 50% of Sonic hedgehog (SHH) medulloblastomas. These mutations were not present across other subgroups of medulloblastoma, and we identified these hotspot mutations in U1 snRNA in only <0.1% of 2,442 cancers, across 36 other tumour types. The mutations occur in 97% of adults (subtype SHHδ) and 25% of adolescents (subtype SHHα) with SHH medulloblastoma, but are largely absent from SHH medulloblastoma in infants. The U1 snRNA mutations occur in the 5' splice-site binding region, and snRNA-mutant tumours have significantly disrupted RNA splicing and an excess of 5' cryptic splicing events. Alternative splicing mediated by mutant U1 snRNA inactivates tumour-suppressor genes (PTCH1) and activates oncogenes (GLI2 and CCND2), and represents a target for therapy. These U1 snRNA mutations provide an example of highly recurrent and tissue-specific mutations of a non-protein-coding gene in cancer.


Assuntos
Neoplasias Cerebelares/genética , Proteínas Hedgehog/genética , Meduloblastoma/genética , RNA Nuclear Pequeno/genética , Adolescente , Adulto , Processamento Alternativo , Proteínas Hedgehog/metabolismo , Humanos , Mutação , Sítios de Splice de RNA , Splicing de RNA
14.
Sci Rep ; 9(1): 13611, 2019 09 20.
Artigo em Inglês | MEDLINE | ID: mdl-31541170

RESUMO

Medulloblastoma is a malignant pediatric tumor that arises from neural progenitors in the cerebellum. Despite a five-year survival rate of ~70%, nearly all patients incur adverse side effects from current treatment strategies that drastically impact quality of life. Roughly one-third of medulloblastoma are driven by aberrant activation of the Sonic Hedgehog (SHH) signaling pathway. However, the scarcity of genetic mutations in medulloblastoma has led to investigation of other mechanisms contributing to cancer pathogenicity including epigenetic regulation of gene expression. Here, we show that Helicase, Lymphoid Specific (HELLS), a chromatin remodeler with epigenetic functions including DNA methylation and histone modification, is induced by Sonic Hedgehog (SHH) in SHH-dependent cerebellar progenitor cells and the developing murine cerebella. HELLS is also up-regulated in mouse and human SHH medulloblastoma. Others have shown that HELLS activity generally results in a repressive chromatin state. Our results demonstrate that increased expression of HELLS in our experimental systems is regulated by the oncogenic transcriptional regulator YAP1 downstream of Smoothened, the positive transducer of SHH signaling. Elucidation of HELLS as one of the downstream effectors of the SHH pathway may lead to novel targets for precision therapeutics with the promise of better outcomes for SHH medulloblastoma patients.


Assuntos
Proteínas Adaptadoras de Transdução de Sinal/metabolismo , Proteínas de Ciclo Celular/metabolismo , DNA Helicases/genética , Meduloblastoma/genética , Proteínas Adaptadoras de Transdução de Sinal/genética , Adulto , Animais , Proteínas de Ciclo Celular/genética , Células Cultivadas , Neoplasias Cerebelares/patologia , Cerebelo/metabolismo , Criança , Cromatina/metabolismo , Montagem e Desmontagem da Cromatina/genética , DNA Helicases/metabolismo , Epigênese Genética/genética , Feminino , Proteínas Hedgehog/metabolismo , Proteínas Hedgehog/fisiologia , Humanos , Masculino , Meduloblastoma/metabolismo , Camundongos , Células-Tronco Neurais/metabolismo , Neurônios/metabolismo , Qualidade de Vida , Transdução de Sinais , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo , Ativação Transcricional , Regulação para Cima , Proteínas de Sinalização YAP
15.
Nature ; 572(7767): 67-73, 2019 08.
Artigo em Inglês | MEDLINE | ID: mdl-31043743

RESUMO

Study of the origin and development of cerebellar tumours has been hampered by the complexity and heterogeneity of cerebellar cells that change over the course of development. Here we use single-cell transcriptomics to study more than 60,000 cells from the developing mouse cerebellum and show that different molecular subgroups of childhood cerebellar tumours mirror the transcription of cells from distinct, temporally restricted cerebellar lineages. The Sonic Hedgehog medulloblastoma subgroup transcriptionally mirrors the granule cell hierarchy as expected, while group 3 medulloblastoma resembles Nestin+ stem cells, group 4 medulloblastoma resembles unipolar brush cells, and PFA/PFB ependymoma and cerebellar pilocytic astrocytoma resemble the prenatal gliogenic progenitor cells. Furthermore, single-cell transcriptomics of human childhood cerebellar tumours demonstrates that many bulk tumours contain a mixed population of cells with divergent differentiation. Our data highlight cerebellar tumours as a disorder of early brain development and provide a proximate explanation for the peak incidence of cerebellar tumours in early childhood.


Assuntos
Neoplasias Cerebelares/genética , Neoplasias Cerebelares/patologia , Evolução Molecular , Feto/metabolismo , Regulação da Expressão Gênica no Desenvolvimento , Regulação Neoplásica da Expressão Gênica , Transcrição Gênica , Animais , Neoplasias Cerebelares/classificação , Cerebelo/citologia , Cerebelo/embriologia , Cerebelo/metabolismo , Criança , Feminino , Feto/citologia , Glioma/classificação , Glioma/genética , Glioma/patologia , Humanos , Meduloblastoma/classificação , Meduloblastoma/genética , Meduloblastoma/patologia , Camundongos , Análise de Sequência de RNA , Análise de Célula Única , Fatores de Tempo , Transcriptoma/genética
16.
Oncogene ; 38(10): 1702-1716, 2019 03.
Artigo em Inglês | MEDLINE | ID: mdl-30348991

RESUMO

Medulloblastoma (MB) is the most frequent malignant pediatric brain tumor, representing 20% of newly diagnosed childhood central nervous system malignancies. Although advances in multimodal therapy yielded a 5-year survivorship of 80%, MB still accounts for the leading cause of childhood cancer mortality. In this work, we describe the epigenetic regulator BMI1 as a novel therapeutic target for the treatment of recurrent human Group 3 MB, a childhood brain tumor for which there is virtually no treatment option beyond palliation. Current clinical trials for recurrent MB patients based on genomic profiles of primary, treatment-naive tumors will provide limited clinical benefit since recurrent metastatic MBs are highly genetically divergent from their primary tumor. Using a small molecule inhibitor against BMI1, PTC-028, we were able to demonstrate complete ablation of self-renewal of MB stem cells in vitro. When administered to mice xenografted with patient tumors, we observed significant reduction in tumor burden in both local and metastatic compartments and subsequent increased survival, without neurotoxicity. Strikingly, serial in vivo re-transplantation assays demonstrated a marked reduction in tumor initiation ability of recurrent MB cells upon re-transplantation of PTC-028-treated cells into secondary recipient mouse brains. As Group 3 MB is often metastatic and uniformly fatal at recurrence, with no current or planned trials of targeted therapy, an efficacious targeted agent would be rapidly transitioned to clinical trials.


Assuntos
Neoplasias Cerebelares/tratamento farmacológico , Meduloblastoma/tratamento farmacológico , Células-Tronco Neoplásicas/efeitos dos fármacos , Complexo Repressor Polycomb 1/antagonistas & inibidores , Bibliotecas de Moléculas Pequenas/administração & dosagem , Animais , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Neoplasias Cerebelares/genética , Neoplasias Cerebelares/metabolismo , Criança , Epigênese Genética , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Humanos , Meduloblastoma/genética , Meduloblastoma/metabolismo , Camundongos , Células-Tronco Neoplásicas/citologia , Células-Tronco Neoplásicas/metabolismo , Complexo Repressor Polycomb 1/genética , Bibliotecas de Moléculas Pequenas/farmacologia , Resultado do Tratamento , Regulação para Cima/efeitos dos fármacos , Ensaios Antitumorais Modelo de Xenoenxerto
17.
Dev Cell ; 48(2): 167-183.e5, 2019 01 28.
Artigo em Inglês | MEDLINE | ID: mdl-30554998

RESUMO

SUFU alterations are common in human Sonic Hedgehog (SHH) subgroup medulloblastoma (MB). However, its tumorigenic mechanisms have remained elusive. Here, we report that loss of Sufu alone is unable to induce MB formation in mice, due to insufficient Gli2 activation. Simultaneous loss of Spop, an E3 ubiquitin ligase targeting Gli2, restores robust Gli2 activation and induces rapid MB formation in Sufu knockout background. We also demonstrated a tumor-promoting role of Sufu in Smo-activated MB (∼60% of human SHH MB) by maintaining robust Gli activity. Having established Gli2 activation as a key driver of SHH MB, we report a comprehensive analysis of its targetome. Furthermore, we identified Atoh1 as a target and molecular accomplice of Gli2 that activates core SHH MB signature genes in a synergistic manner. Overall, our work establishes the dual role of SUFU in SHH MB and provides mechanistic insights into transcriptional regulation underlying Gli2-mediated SHH MB tumorigenesis.


Assuntos
Transformação Celular Neoplásica/genética , Proteínas Nucleares/genética , Proteínas Repressoras/genética , Proteína Gli2 com Dedos de Zinco/genética , Animais , Proteínas Hedgehog/genética , Humanos , Meduloblastoma/genética , Camundongos
18.
Sci Rep ; 8(1): 14894, 2018 10 05.
Artigo em Inglês | MEDLINE | ID: mdl-30291261

RESUMO

Intraoperative image-guided surgical navigation for craniospinal procedures has significantly improved accuracy by providing an avenue for the surgeon to visualize underlying internal structures corresponding to the exposed surface anatomy. Despite the obvious benefits of surgical navigation, surgeon adoption remains relatively low due to long setup and registration times, steep learning curves, and workflow disruptions. We introduce an experimental navigation system utilizing optical topographical imaging (OTI) to acquire the 3D surface anatomy of the surgical cavity, enabling visualization of internal structures relative to exposed surface anatomy from registered preoperative images. Our OTI approach includes near instantaneous and accurate optical measurement of >250,000 surface points, computed at >52,000 points-per-second for considerably faster patient registration than commercially available benchmark systems without compromising spatial accuracy. Our experience of 171 human craniospinal surgical procedures, demonstrated significant workflow improvement (41 s vs. 258 s and 794 s, p < 0.05) relative to benchmark navigation systems without compromising surgical accuracy. Our advancements provide the cornerstone for widespread adoption of image guidance technologies for faster and safer surgeries without intraoperative CT or MRI scans. This work represents a major workflow improvement for navigated craniospinal procedures with possible extension to other image-guided applications.


Assuntos
Encéfalo , Interpretação de Imagem Assistida por Computador/métodos , Imageamento Tridimensional , Imageamento por Ressonância Magnética/métodos , Medula Espinal , Cirurgia Assistida por Computador , Animais , Encéfalo/diagnóstico por imagem , Encéfalo/cirurgia , Humanos , Imageamento Tridimensional/instrumentação , Imageamento Tridimensional/métodos , Curva de Aprendizado , Neurocirurgiões/educação , Medula Espinal/diagnóstico por imagem , Medula Espinal/cirurgia , Cirurgia Assistida por Computador/instrumentação , Cirurgia Assistida por Computador/métodos , Suínos
20.
Cell ; 172(5): 1050-1062.e14, 2018 02 22.
Artigo em Inglês | MEDLINE | ID: mdl-29474906

RESUMO

While the preponderance of morbidity and mortality in medulloblastoma patients are due to metastatic disease, most research focuses on the primary tumor due to a dearth of metastatic tissue samples and model systems. Medulloblastoma metastases are found almost exclusively on the leptomeningeal surface of the brain and spinal cord; dissemination is therefore thought to occur through shedding of primary tumor cells into the cerebrospinal fluid followed by distal re-implantation on the leptomeninges. We present evidence for medulloblastoma circulating tumor cells (CTCs) in therapy-naive patients and demonstrate in vivo, through flank xenografting and parabiosis, that medulloblastoma CTCs can spread through the blood to the leptomeningeal space to form leptomeningeal metastases. Medulloblastoma leptomeningeal metastases express high levels of the chemokine CCL2, and expression of CCL2 in medulloblastoma in vivo is sufficient to drive leptomeningeal dissemination. Hematogenous dissemination of medulloblastoma offers a new opportunity to diagnose and treat lethal disseminated medulloblastoma.


Assuntos
Meduloblastoma/irrigação sanguínea , Meduloblastoma/patologia , Neoplasias Meníngeas/irrigação sanguínea , Neoplasias Meníngeas/secundário , Aloenxertos , Animais , Linhagem Celular Tumoral , Quimiocina CCL2/metabolismo , Cromossomos Humanos Par 10/genética , Feminino , Humanos , Masculino , Meduloblastoma/genética , Camundongos SCID , Células Neoplásicas Circulantes , Parabiose
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