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BACKGROUND AND OBJECTIVES: Although ventriculoperitoneal (VP) shunts are a common treatment for hydrocephalus, there are complication risks including infections. Late complications such as ventriculitis from ascending abdominal infections can have severe consequences. However, the incidence of central nervous system (CNS) infections in VP shunt patients with abdominal infections is not well understood. We aimed to determine the incidence of CNS infections in VP shunt patients admitted with abdominal infections. METHODS: Using the National Inpatient Sample, we studied patients from 2016 to 2019 to determine the incidence of CNS infections in VP shunt patients admitted with abdominal infections. Results were compared with VP shunt patients admitted for primary pneumonia. RESULTS: Among 725 VP shunt patients presenting with abdominal infections, 20 (2.8%) had CNS infections. Chronic obstructive pulmonary disease, hypertension, older age, and a smoking history were more common in patients with CNS infections and primary abdominal infection (P < .05). Patients who developed CNS infection had a significantly higher likelihood of both blood transfusion and coma but a lower likelihood of seizures. VP shunt patients with CNS infections were more likely to undergo shunt removal (odds ratio [OR] = 23.167, P < .001). 4.1% of VP shunt patients with primary abdominal infections died during admission. In a population of primary abdominal infection and pneumonia patients with VP shunts, a multivariate logistic regression analysis controlling for age, sex, and comorbidities identified abdominal infection as an independent risk factor for both CNS infection (OR = 51.208, P < .001) and inpatient death (OR = 3.417, P < .001). Among 6620 VP shunt patients admitted with primary pneumonia, only 5 (0.1%) had CNS infection compared with 20 (2.8%) in those with a primary abdominal infection (OR = 37.532, P < .001), and mortality was 1.6% vs 4.1% for those with a primary abdominal infection (P < .05). CONCLUSION: CNS infections in VP-shunted patients with abdominal infections are relatively rare but may lead to increased risks of death and other serious adverse outcomes.
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BACKGROUND: Nerve transfer is a surgical technique in which a redundant or expendable fascicle is transferred or coapted to an injured nerve distal to the site of injury for the purpose of reinnervation. Successful nerve transfer is dependent on correct intraoperative identification of donor and recipient nerves. OBSERVATIONS: An 8-year-old male was recommended for ulnar nerve fascicle to biceps branch of musculocutaneous nerve transfer to restore elbow flexion weakness after a demyelinating spinal cord injury. The biceps branch was identified approximately midway along the upper arm. Proximal musculocutaneous nerve stimulation induced hand movement and electromyography activity in the median nerve muscles. Neurolysis of the thickened proximal structure revealed fusion of the musculocutaneous and median nerves. Because of the proximity of the median and musculocutaneous nerves, median rather than ulnar nerve fascicles were used as donors for transfer. LESSONS: The authors provide the first reported intraoperative finding of an anatomical variant in which the musculocutaneous nerve and median nerve were fused in the upper arm, confirmed through intraoperative electrical stimulation. Surgeons should be aware of this rare anatomical variant to ensure correct nerve identification when performing nerve transfers in the proximal upper extremity.
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Epistaxis is a commonly occurring phenomenon which is defined as "bleeding from inside the nose" and often presents as an emergency. The management of epistaxis involves many factors with regard to the treatment and ultimate control of the condition. Each patient presenting with epistaxis should be well assessed clinically and managed accordingly. Endoscopic sphenopalatine artery cauterization is a safe, simple and effective procedure in the management of refractory epistaxis. Moreover, in view of minimal morbidity, higher success rate, shorter hospital stays and higher patient satisfaction, our current practice is to consider this treatment option in the management of cases not responding to conservative treatment modalities. A total of 11 patients (8 males and 3 females) underwent sphenopalatine artery cauterization during the study period. All patients were hypertensive and were refractory to treatment with general measures, anterior nasal packing and Foley catheter. The mean age of the study population was 58.36 and the range was 39-70 years. The epistaxis was rapidly controlled in all patients without any intraoperative or postoperative complications. The follow up period was 60-90 days. Strict control of hypertension was done throughout the follow up period. None of the patients developed epistaxis in the follow up period. The sphenopalatine artery cauterization technique using nasal endoscope was safe, simple, fast and effective with low rates of morbidity and complications for the management of refractory epistaxis. It was concluded that endoscopic sphenopalatine artery cauterization should be considered as an immediate second line treatment where conservative measures fail and it is proved to be of low morbidity and cost effective.
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Medulloblastoma (MB) is the most common malignant pediatric posterior fossa tumor. Recent genetic, epigenetic, and transcriptomic analyses have classified MB into three subgroups, Wingless Type (WNT), Sonic Hedgehog (SHH), and non-WNT/non-SHH (originally termed Group 3 and Group 4), with discrete patient profiles and prognoses. WNT is the least common subgroup with the best prognosis, characterized by nuclear ß-catenin expression, mutations in Catenin beta-1 (CTNNB1), and chromosome 6 monosomy. SHH tumors contain mutations and alterations in GLI1, GLI2, SUFU, and PTCH1 genes, which constitutively activate the SHH pathway. Originally, the presence of TP53 gene alterations and/or MYC amplifications was considered the most reliable prognostic factor. However, recent molecular analyses have subdivided SHH MB into several subtypes with distinct characteristics such as age, TP53 mutation, MYC amplification, presence of metastases, TERT promoter alterations, PTEN loss, and other chromosomal alterations as well as SHH pathway-related gene mutations. The third non-WNT/non-SHH MB (Group3/4) subgroup is genetically highly heterogeneous and displays several molecular patterns, including MYC and OTX2 amplification, GFI1B activation, KBTBD4 mutation, GFI1 rearrangement, PRDM6 enhancer hijacking, KDM6A mutation, LCA histology, chromosome 10 loss, isochromosome 17q, SNCAIP duplication, and CDK6 amplification. However, based on molecular profiling and methylation patterns, additional non-WNT/non-SHH MB subtypes have been described. Recent WHO (2021) guidelines stratified MB into four molecular subgroups with four and eight further subgroups for SHH and non-WNT/non-SHH MB, respectively. In this review, we discuss advancements in genetics, epigenetics, and transcriptomics for better characterization, prognostication, and treatment of MB using precision medicine.
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Neoplasias Cerebelares , Meduloblastoma , Neoplasias Cerebelares/genética , Neoplasias Cerebelares/terapia , Criança , Aberrações Cromossômicas , Perfilação da Expressão Gênica , Proteínas Hedgehog/metabolismo , Humanos , Meduloblastoma/genética , Meduloblastoma/metabolismo , Meduloblastoma/terapia , MutaçãoRESUMO
BACKGROUND: Evidence regarding the utilization and outcomes of endovascular thrombectomy (EVT) for pediatric ischemic stroke is limited, and justification for its use is largely based on extrapolation from clinical benefits observed in adults. METHODS: Weighted discharge data from the National Inpatient Sample were queried to identify pediatric patients with ischemic stroke (<18 years old) during the period of 2010 to 2019. Complex samples statistical methods were used to characterize the profiles and clinical outcomes of EVT-treated patients. Propensity adjustment was performed to address confounding by indication for EVT based on disparities in baseline characteristics between EVT-treated patients and those medically managed. RESULTS: Among 7365 pediatric patients with ischemic stroke identified, 190 (2.6%) were treated with EVT. Utilization significantly increased in the post-EVT clinical trial era (2016-2019; 1.7% versus 4.0%; P<0.001), while the use of decompressive hemicraniectomy decreased (2.8% versus 0.7%; P<0.001). On unadjusted analysis, 105 (55.3%) EVT-treated patients achieved favorable functional outcomes at discharge (home or to acute rehabilitation), while no periprocedural iatrogenic complications or instances of contrast-induced kidney injury were reported. Following propensity adjustment, EVT-treated patients demonstrated higher absolute but nonsignificant rates of favorable functional outcomes in comparison with medically managed patients (55.3% versus 52.8%; P=0.830; adjusted hazard ratio, 1.01 [95% CI, 0.51-2.03]; P=0.972 for unfavorable outcome). Among patients with baseline National Institutes of Health Stroke Scale score >11 (75th percentile of scores in cohort), EVT-treated patients trended toward higher rates of favorable functional outcomes compared with those treated medically only (71.4% versus 55.6%; P=0.146). In a subcohort assessment of EVT-treated patients, those administered preceding thrombolytic therapy (n=79, 41.6%) trended toward higher rates of favorable functional outcomes (63.3% versus 49.5%; P=0.060). CONCLUSIONS: This cross-sectional evaluation of the clinical course and short-term outcomes of pediatric patients with ischemic stroke treated with EVT demonstrates that EVT is likely a safe modality which confers high rates of favorable functional outcomes.
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Isquemia Encefálica , Procedimentos Endovasculares , AVC Isquêmico , Acidente Vascular Cerebral , Adolescente , Criança , Estudos Transversais , Procedimentos Endovasculares/métodos , Humanos , Acidente Vascular Cerebral/terapia , Trombectomia/métodos , Resultado do TratamentoRESUMO
Aberrant signaling of mechanistic target of rapamycin (mTOR aka mammalian target of rapamycin) is shown to be linked to tumorigenesis of numerous malignancies including glioblastoma (GB). mTOR is a serine threonine kinase that functions by forming two multiprotein complexes. These complexes are named mTORC1 and mTORC2 and activate downstream substrates that execute cellular and metabolic functions. This signaling cascade of PI3K/AKT/mTOR is often upregulated due to frequent loss of the tumor suppressor PTEN, a phosphatase that functions antagonistically to PI3K. mTOR regulates cell growth, motility, and metabolism by forming two multiprotein complexes, mTORC1 and mTORC2, which are composed of special binding partners. These complexes are sensitive to distinct stimuli. mTORC1 is sensitive to nutrients and mTORC2 is regulated via PI3K and growth factor signaling. Since rapamycin and its analogue are less effective in treatment of GB, we used novel ATP-competitive dual inhibitors of mTORC1 and mTORC2, namely, Torin1, Torin2, and XL388. Torin2 caused a concentration dependent pharmacodynamic effects on inhibition of phosphorylation of the mTORC1 substrates S6KSer235/236 and 4E-BP1Thr37/46 as well as the mTORC2 substrate AKTSer473 resulting in suppression of tumor cell proliferation and migration. Torin1 showed similar effects only at higher doses. Another small molecule compound, XL388 suppressed cell proliferation at a higher dose but failed to inhibit cell migration. Torin1 suppressed phosphorylation of PRAS40Thr246, however, Torin2 completely abolished it. XL388 treatment inhibited the phosphorylation of PRAS40Thr246 at higher doses only. These findings underscore the use of novel compounds in treatment of cancer. In addition, formulation of third generation mTOR inhibitor "Rapalink-1" may provide new aspects to target mTOR pathways. Numerous inhibitors are currently being used in clinical trials that are aimed to target activated mTOR pathways.
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Glioblastoma , Proliferação de Células , Glioblastoma/tratamento farmacológico , Glioblastoma/genética , Glioblastoma/metabolismo , Humanos , Alvo Mecanístico do Complexo 1 de Rapamicina/metabolismo , Alvo Mecanístico do Complexo 2 de Rapamicina , Fosfatidilinositol 3-Quinases/genética , Fosfatidilinositol 3-Quinases/metabolismo , Proteínas Proto-Oncogênicas c-akt/metabolismo , Transdução de Sinais , Serina-Treonina Quinases TOR/genética , Serina-Treonina Quinases TOR/metabolismoRESUMO
Pediatric subdural hematomas (SDH) are associated with arachnoid cysts (AC), particularly in the middle cranial fossa (MCF). Operative management of these hemorrhages is a mainstay of treatment. Conservative management may be an option if there is minimal mass effect and the patient is mildly symptomatic. A 14-year-old male presented with right frontal headaches that worsened with activity. He was found to have a large right MCF AC. Scheduled routine outpatient follow-up CT of the head demonstrated bilateral SDH. There was no history of significant head trauma. He was admitted for close observation and his inpatient scans remained stable. Outpatient follow-up imaging over the course of three and a half years demonstrated resolution of SDH and decreased AC size. He denied headaches and continued doing well in school. ACs are a risk factor for the development of SDH in young male patients after minor trauma. Development of intracranial hypotension secondary to AC rupture may have contributed to the development of bilateral SDH in our patient. We demonstrate here that close clinical follow up with serial imaging may be considered a management strategy in these patients.
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Medulloblastomas are one of the most common malignant pediatric brain tumors. Therapy has evolved into multimodality treatments consisting of surgery, radiation, and adjuvant chemotherapy. While craniospinal radiation remains standard for patients older than 3 years of age, it is not free of side effects and long-term complications. The development of malignant gliomas following therapy is a well-documented phenomenon. However, the majority of these radiation-induced glioblastomas (RIG) are intracranial, and intraspinal lesions are rare. The patient is a 22-year-old female with a history of a posterior fossa medulloblastoma diagnosed 8 years prior for which she underwent surgical resection followed by adjuvant chemotherapy and craniospinal radiation. Surveillance imaging showed no evidence of recurrence or new lesions for the following 5 years. She presented with nausea and vomiting and imaging revealing a new intramedullary cervical spinal cord lesion. She then developed acute quadriplegia several days after presentation. She underwent a cervical laminectomy and resection of this lesion, which was initially diagnosed as recurrent medulloblastoma before genomic analysis ultimately revealed it to be a RIG. Spinal RIGs that occur secondary to treatment for an intracranial neoplasm are exceedingly rare. The majority of spinal cord RIGs have been reported secondary to treatment for tumors outside of the neuroaxis, while the majority of RIGs secondary to treatment for intracranial tumors remain intracranial. Nevertheless, RIGs are associated with a short clinical history, aggressive progression, and poor outcome.
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Neoplasias Cerebelares , Glioblastoma , Meduloblastoma , Adulto , Neoplasias Cerebelares/diagnóstico por imagem , Neoplasias Cerebelares/etiologia , Neoplasias Cerebelares/terapia , Criança , Feminino , Humanos , Meduloblastoma/diagnóstico por imagem , Meduloblastoma/terapia , Recidiva Local de Neoplasia , Medula Espinal , Adulto JovemRESUMO
INTRODUCTION: The use of decompressive craniectomy in children is controversial and often reserved for patients with refractory intracranial hypertension. Following decompression, skin closure in select cases can be challenging due to brain herniation and swelling through the craniectomy defect. In these cases, partial cortical debridement is sometimes performed. METHODS: We describe two cases in which a synthetic skin substitute was used to facilitate a tension-free closure, rather than performing a partial lobectomy. RESULTS: At 6-month follow-up, both patients are at preoperative cognitive baseline, with some residual hemiparesis. DISCUSSION: We believe that use of a synthetic skin substitute for skin closure after decompression is a suitable option for closure of traumatic scalp wounds and may contribute to improved functional outcome in patients with severe intraoperative brain swelling.
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Edema Encefálico , Craniectomia Descompressiva , Hipertensão Intracraniana , Pele Artificial , Criança , Humanos , Hipertensão Intracraniana/cirurgia , Couro Cabeludo/cirurgia , Resultado do TratamentoRESUMO
A spontaneous spinal epidural hematoma is a collection of blood in the spinal epidural space that occurs in the absence of trauma. They most commonly present in the fourth to fifth decade in life with acute onset neck or back pain with delayed neurologic deficit. However, this presentation is often complicated in children because of the limitations in the pediatric neurologic exam. Magnetic resonance imaging is the imaging modality of choice for diagnosis. Here is a rare case of an infant spontaneous spinal epidural hematoma whose diagnosis was delayed because of a recent history of fever and viral pharyngitis before his development of neurologic deficits. Spontaneous spinal epidural hematomas are a rare phenomenon, which often present with nonspecific symptoms in the pediatric population. This diagnosis should be considered to initiate treatment in a timely manner. The treatment typically is emergent surgical decompression to minimize the risk of permanent neurologic deficit.
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Hematoma Epidural Espinal/diagnóstico , Hematoma Epidural Espinal/cirurgia , Diagnóstico Diferencial , Humanos , Lactente , Imageamento por Ressonância Magnética , Masculino , Punção Espinal , TraqueostomiaRESUMO
Hemophagocytic lymphohistiocytosis (HLH) is a rare disease process characterized by aberrant immune system activation and an exaggerated inflammatory response. Establishing the diagnosis may be challenging and is achieved by satisfying a number of clinical criteria, in addition to demonstrating tissue hemophagocytosis. This syndrome is rapidly fatal if prompt diagnosis and treatment are not achieved. The authors present the case of a 17-year-old male patient with CNS HLH involving both the brain and spinal cord, highlighting the variable CNS manifestations in pediatric patients with HLH and the challenges that accompany establishing diagnosis.
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Activation of Mechanistic target of rapamycin (mTOR) signaling plays a crucial role in tumorigenesis of numerous malignancies including glioblastoma (GB). The Canonical PI3K/Akt/mTOR signaling cascade is commonly upregulated due to loss of the tumor suppressorm PTEN, a phosphatase that acts antagonistically to the kinase (PI3K) in conversion of PIP2 to PIP3. mTOR forms two multiprotein complexes, mTORC1 and mTORC2 which are composed of discrete protein binding partners to regulate cell growth, motility, and metabolism. These complexes are sensitive to distinct stimuli, as mTORC1 is sensitive to nutrients while mTORC2 is regulated via PI3K and growth factor signaling. The main function of mTORC1 is to regulate protein synthesis and cell growth through downstream molecules: 4E-BP1 (also called EIF4E-BP1) and S6K. On the other hand, mTORC2 is responsive to growth factor signaling by phosphorylating the C-terminal hydrophobic motif of some AGC kinases like Akt and SGK and it also plays a crucial role in maintenance of normal and cancer cells through its association with ribosomes, and is involved in cellular metabolic regulation. mTORC1 and mTORC2 regulate each other, as shown by the fact that Akt regulates PRAS40 phosphorylation, which disinhibits mTORC1 activity, while S6K regulates Sin1 to modulate mTORC2 activity. Allosteric inhibitors of mTOR, rapamycin and rapalogs, remained ineffective in clinical trials of Glioblastoma (GB) patients, in part due to their incomplete inhibition of mTORC1 as well as unexpected activation of mTOR via the loss of negative feedback loops. In recent years, novel ATP binding inhibitors of mTORC1 and mTORC2 suppress mTORC1 activity completely by total dephosphorylation of its downstream substrate pS6KSer235/236, while effectively suppressing mTORC2 activity, as demonstrated by complete dephosphorylation of pAKTSer473. Furthermore by these novel combined mTORC1/mTORC2 inhibitors reduced the proliferation and self-renewal of GB cancer stem cells. However, a search of more effective way to target mTOR has generated a third generation inhibitor of mTOR, "Rapalink", that bivalently combines rapamycin with an ATP-binding inhibitor, which effectively abolishes the mTORC1 activity. All in all, the effectiveness of inhibitors of mTOR complexes can be judged by their ability to suppress both mTORC1/mTORC2 and their ability to impede both cell proliferation and migration along with aberrant metabolic pathways.
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Alvo Mecanístico do Complexo 1 de Rapamicina/metabolismo , Alvo Mecanístico do Complexo 2 de Rapamicina/metabolismo , Transdução de Sinais , Animais , Proliferação de Células , Humanos , Alvo Mecanístico do Complexo 1 de Rapamicina/antagonistas & inibidores , Alvo Mecanístico do Complexo 1 de Rapamicina/genética , Alvo Mecanístico do Complexo 2 de Rapamicina/antagonistas & inibidores , Alvo Mecanístico do Complexo 2 de Rapamicina/genética , Proteínas Proto-Oncogênicas c-akt/genética , Proteínas Proto-Oncogênicas c-akt/metabolismoRESUMO
Brain metastases are the leading cause of morbidity and mortality among cancer patients, and are reported to occur in about 40% of cancer patients with metastatic disease in the United States of America. Primary tumor cells appear to detach from the parent tumor site, migrate, survive and pass through the blood brain barrier in order to establish cerebral metastases. This complex process involves distinct molecular and genetic mechanisms that mediate metastasis from these primary organs to the brain. Furthermore, an interaction between the invading cells and cerebral milieu is shown to promote this process as well. Here, we review the mechanisms by which primary cancer cells metastasize to the brain via a mechanism called epithelial-to-mesenchymal transition, as well as the involvement of certain microRNA and genetic aberrations implicated in cerebral metastases from the lung, breast, skin, kidney and colon. While the mechanisms governing the development of brain metastases remain a major hindrance in treatment, understanding and identification of the aforementioned molecular pathways may allow for improved management and discovery of novel therapeutic targets.
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Neoplasias Encefálicas/secundário , Animais , Barreira Hematoencefálica/patologia , Neoplasias Encefálicas/genética , Neoplasias Encefálicas/metabolismo , Neoplasias Encefálicas/patologia , Transição Epitelial-Mesenquimal , Humanos , Transdução de SinaisRESUMO
Conjoined twins are identical twins that have incompletely separated in utero. The prognosis for conjoined twins is poor and management in a skilled tertiary care centre is paramount for definitive care. We describe our experience with a telemedical consultation on conjoined twins in The Dominican Republic from our eHealth centre in Valhalla, NY. The patients were two month old, female, pygopagus conjoined twins. A multidisciplinary teleconference was initiated with the patients, their family, the referring paediatrician and our team. Based on this teleconsultation, the team felt as though the twins may be amenable to a surgical separation. They presented to our centre in Valhalla, NY, for a detailed physical examination and series of imaging studies. Soon after, the patients underwent a successful 21 h separation procedure and were discharged 12 weeks later. To our knowledge, this is one of the first reports of an international teleconsultation leading to a successful conjoined twin separation procedure.
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Consulta Remota/métodos , Gêmeos Unidos/cirurgia , Feminino , Humanos , Recém-Nascido , Prognóstico , Centros de Atenção Terciária/organização & administraçãoRESUMO
OBJECTIVE: Placement of intraventricular catheters in oncology patients can be associated with morbidity given their small to slit-like ventricles and underlying hematologic disorders. We studied the accuracy of placing Ommaya reservoirs using neuronavigation and a flexible neuroendoscope to verify catheter positioning. METHODS: Ommaya reservoirs placed in 25 oncology patients between 2013 and 2015 were retrospectively reviewed. Twenty-five ventricular catheters were placed using the AxiEM stealth frameless neuronavigation system and a flexible neuroendoscope. Postoperative catheter accuracy, operative complications, and postoperative complications were assessed. We discuss surgical protocol and technical nuances. RESULTS: All ventricular catheters were successfully placed into the ipsilateral (84%) or contralateral (16%) foramen of Monro. A single ventricular catheter pass was needed to cannulate the ventricle in 96% of patients. The mean accuracy was 4.09 ± 3.47 mm from the target, the ipsilateral foramen of Monro. One patient had a catheter tract hemorrhage seen on postoperative imaging related to thrombocytopenia. No postoperative neurologic deficits were seen. CONCLUSIONS: A combined neuronavigation and neuroendoscopic approach improved catheter tip accuracy compared with accuracy rates described in the literature using other techniques. This approach can be adapted toward routine clinical practice of placing ventricular shunt catheters and Ommaya reservoirs.
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Catéteres , Campos Eletromagnéticos , Neuroendoscópios , Neuronavegação/métodos , Procedimentos Neurocirúrgicos/instrumentação , Procedimentos Neurocirúrgicos/métodos , Adulto , Idoso , Feminino , Seguimentos , Humanos , Masculino , Carcinomatose Meníngea/diagnóstico por imagem , Carcinomatose Meníngea/cirurgia , Pessoa de Meia-Idade , Leucemia-Linfoma Linfoblástico de Células Precursoras/diagnóstico por imagem , Leucemia-Linfoma Linfoblástico de Células Precursoras/cirurgia , Estudos Retrospectivos , Adulto JovemRESUMO
The PI3K-AKT-mTOR signaling axis is central to the transformed phenotype of glioblastoma (GBM) cells, due to frequent loss of tumor suppressor PTEN (phosphatase and tensin homolog deleted on chromosome 10). The mechanistic target of rapamycin (mTOR) kinase is present in two cellular multi-protein complexes, mTORC1 and mTORC2, which have distinct subunit composition, substrates and mechanisms of action. Targeting the mTOR protein is a promising strategy for GBM therapy. However, neither of these complexes is fully inhibited by the allosteric inhibitor of mTOR, rapamycin or its analogs. Herein, we provide evidence that the combined inhibition of mTORC1/2, using the ATP-competitive binding inhibitor PP242, would effectively suppress GBM growth and dissemination as compared to an allosteric binding inhibitor of mTOR. GBM cells treated with PP242 demonstrated significantly decreased activation of mTORC1 and mTORC2, as shown by reduced phosphorylation of their substrate levels, p70 S6K(Thr389) and AKT(Ser473), respectively, in a dose-dependent manner. Furthermore, insulin induced activation of these kinases was abrogated by pretreatment with PP242 as compared with rapamycin. Unlike rapamycin, PP242 modestly activates extracellular regulated kinase (ERK1/2), as shown by expression of pERK(Thr202/Tyr204). Cell proliferation and S-phase entry of GBM cells was significantly suppressed by PP242, which was more pronounced compared to rapamycin treatment. Lastly, PP242 significantly suppressed the migration of GBM cells, which was associated with a change in cellular behavior rather than cytoskeleton loss. In conclusion, these results underscore the potential therapeutic use of the PP242, a novel ATP-competitive binding inhibitor of mTORC1/2 kinase, in suppression of GBM growth and dissemination.
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Neoplasias Encefálicas/metabolismo , Glioblastoma/metabolismo , Complexos Multiproteicos/metabolismo , Serina-Treonina Quinases TOR/metabolismo , Trifosfato de Adenosina/química , Ligação Competitiva , Linhagem Celular Tumoral , Movimento Celular , Proliferação de Células , Sobrevivência Celular , Quimiotaxia , MAP Quinases Reguladas por Sinal Extracelular/metabolismo , Humanos , Indóis/química , Insulina/química , Alvo Mecanístico do Complexo 1 de Rapamicina , Alvo Mecanístico do Complexo 2 de Rapamicina , Fenótipo , Fosforilação/efeitos dos fármacos , Ligação Proteica , Purinas/química , Fase S , Transdução de Sinais/efeitos dos fármacos , Sirolimo/químicaRESUMO
Gangliogliomas are rare tumors of the central nervous system that are usually found in the supratentorial compartment, although cases throughout the nervous system have been described. They are generally low-grade malignancies that are amenable to cure by surgical resection. Most manifest as seizures, though, based on location, they can present with focal neurological deficits. We present here a rare case of an infratentorial ganglioglioma presenting with hemorrhage. To our knowledge this is the only reported case of a hemorrhagic ganglioglioma and, as such, we examine its possible prognosis.
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Neoplasias Encefálicas/complicações , Ganglioglioma/complicações , Hemorragias Intracranianas/etiologia , Edema Encefálico/diagnóstico por imagem , Edema Encefálico/etiologia , Neoplasias Encefálicas/diagnóstico por imagem , Criança , Feminino , Quarto Ventrículo/diagnóstico por imagem , Ganglioglioma/diagnóstico por imagem , Humanos , Hidrocefalia/diagnóstico por imagem , Hidrocefalia/etiologia , Hemorragias Intracranianas/diagnóstico por imagem , Imageamento por Ressonância Magnética , Prognóstico , Terceiro Ventrículo/diagnóstico por imagem , Tomografia Computadorizada por Raios XRESUMO
Medulloblastoma is the most common malignant brain tumor in children. Recent studies have implicated sonic hedgehog (SHH) and insulin growth factor (IGF) as important mediators in deregulated pathways, which directly inactivate tuberous sclerosis complex, leading to activation of the serine/threonine kinase, mammalian target of rapamycin (mTOR). mTOR consists of two catalytic subunits of biochemically distinct complexes called mTORC1 and mTORC2. This study aims to further elucidate the role of the mTOR pathway, in the development of medulloblastoma, and assess the use of mTOR inhibitors as novel therapeutic agents. Medulloblastoma cells treated with mTORC1 inhibitor, rapamycin, down-regulated pERK expression initially; however ERK activation was evident upon prolonged treatment. Phosphorylation of mTORC1 substrate, p70S6K at thr389 was reduced by rapamycin and pretreatment with rapamycin abrogated platelet-derived growth factor (PDGF)-induced activation of S6K, as well as that of mTORC2 substrate pAKT(Ser473). Activation of AKT was decreased at 1, 3, and 6 h of treatment, but extended treatment with rapamycin increased expression of pAKT(Ser473). Expression of cyclic dependent kinase inhibitor, P27, decreased following PDGF and increased following rapamycin treatment, suggesting their respective impact on cell proliferation via cell cycle control. Cell proliferation was increased by 12-O-tetradecanoylphorbol-13-acetate (TPA) treatment of medulloblastoma cells, while it was suppressed following treatment with rapamycin or U0126 (MEK1/2 inhibitor). pp242, a novel combined mTORC1/2 inhibitor, and rapamycin limited proliferation by reducing the S-Phase entry as assessed by EdU incorporation, while PDGF increased EdU incorporation. pp242 reduced the number of cells entering the S-phase to a greater extent than did rapamycin. Migration of medulloblastoma cells towards fibronectin was suppressed in a time-dependent manner after rapamycin treatment. These results indicate that the mTOR pathway is involved in the pathogenesis of medulloblastoma, and that targeting this pathway may provide a strategy for therapy of medulloblastoma.
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Neoplasias Cerebelares/enzimologia , Meduloblastoma/enzimologia , Fosfatidilinositol 3-Quinases/metabolismo , Transdução de Sinais , Serina-Treonina Quinases TOR/metabolismo , Western Blotting , Linhagem Celular Tumoral , Neoplasias Cerebelares/patologia , Ativação Enzimática , Imunofluorescência , Humanos , Meduloblastoma/patologia , Fosforilação , Serina-Treonina Quinases TOR/antagonistas & inibidoresRESUMO
Deep brain stimulation (DBS) is a common surgical procedure used for the treatment of Parkinson's disease (PD) and essential tremor. A potential complication of this procedure is hardware failure. The authors report a case of DBS hardware failure in which repeated fractures of the extension wire were caused by abnormal rotational movements of the IPG placed in the loose subclavicular tissue of an overweight female. Implantation of the IPG in the suprascapular area prevented further extension wire fractures. This strategy may be especially relevant in overweight females with loose subclavicular tissue.
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OBJECT: All children born with a myelomeningocele at the authors' institution undergo aggressive treatment to maintain or improve functional outcome. Consequently, when any neurological, orthopedic, and/or urological changes are noted, a search for the cause is initiated. The most common cause of decline in a child born with a myelomeningocele is shunt malfunction. The second most common cause is tethering of the distal spinal cord at the site of the original back closure. In this report, the authors review the indicators of symptomatic spinal cord tethering and discuss the surgical interventions and outcomes in the children with myelomeningocele who underwent treatment at Children's Memorial Hospital from 1975 to 2008. METHODS: Among the 502 children who underwent original closure at Children's Memorial Hospital, a symptomatic tethered spinal cord developed in 114 (23%). Eighty-one patients (71%) have undergone 1 untethering procedure, and 33 patients (29%) have undergone multiple untetherings, for a total of 163 total surgeries. The indicators of symptomatic spinal cord tethering include scoliosis, decline in lower-extremity (LE) motor strength, LE contractures, LE spasticity, gait change, urinary changes, and pain. RESULTS: Pain has shown the best response to surgical untethering, with 100% of children experiencing postoperative improvement. The results of long-term follow-up (average 12 years, range 1 month-23.3 years) in this cohort demonstrated scoliosis progression after surgical untethering in 52% of patients, with 28% requiring spinal fusion. On the 3-month postoperative manual muscle test, 70% of patients showed improved LE muscle strength compared to preoperatively. Gait was also similarly improved after untethering as evaluated by an orthopedic surgeon. Spasticity improved in two-thirds of the cohort, and as expected, LE contractures were stable (78%) postoperatively, as assessed by orthopedic and rehabilitation medicine specialists. Urologically, 64% of patients showed improvements on postoperative bladder evaluation. CONCLUSIONS: Although this is a clinical outcome study with no control group, the authors' experience has been that tethered cord release is beneficial in maintaining neurological, urological, and orthopedic functioning in children born with a myelomeningocele.