A continuing clinical education course to maintain clinical competencies and foster new clinical knowledge during the graduate school years of MD-PhD training.

Introduction: Most students in MD-PhD programs take a leave of absence from medical school to complete PhD training, which promotes a natural loss of clinical skills and knowledge and could negatively impact a student's long-term clinical knowledge. To address this concern, clinical refresher courses in the final year of PhD training have traditionally been used; however, effectiveness of such courses versus a longitudinal clinical course spanning all PhD training years is unclear.

Methods: The University of Alabama at Birmingham MD-PhD Program implemented a comprehensive continuing clinical education (CCE) course spanning PhD training years that features three course components: (1) clinical skills; (2) clinical knowledge; and (3) specialty exposure activities.

Updates in the Management of Central and Peripheral Nervous System Tumors among Patients with Neurofibromatosis Type 1 and Neurofibromatosis Type 2.

Background: Neurofibromatosis type 1 and neurofibromatosis type 2 are unrelated, distinct genetic disorders characterized by the development of central and peripheral nervous system tumors.

Summary: Neurofibromatosis type 1 is the most common inherited tumor predisposition syndrome with a lifelong increased risk of benign and malignant tumor development, such as glioma and nerve sheath tumors. Neurofibromatosis type 2 classically presents with bilateral vestibular schwannoma, yet it is also associated with non-vestibular schwannoma, meningioma, and ependymoma.

Clinical Reasoning: A 12-Month-Old Male Child With Staring Episodes, Ataxia, and Right-sided Weakness.

, or raccoon roundworm, is a rare cause of eosinophilic meningoencephalitis with historically poor clinical outcomes. Symptoms of neural larval migrans begin approximately 2-4 weeks after ingestion with fatigue, nausea, fever, and lethargy and then rapidly progress to weakness, incoordination, ataxia, seizures, altered mental status, and finally coma. Only 31 other cases of CNS neural larval migrans have been reported, with more than 25% being lethal.

Characteristics of Moyamoya Syndrome in Pediatric Patients With Neurofibromatosis Type 1.

Background: Moyamoya syndrome (MMS) is a progressive cerebral arteriopathy with increased incidence in children with neurofibromatosis type 1 (NF1). Despite the potential for significant neurological morbidity including stroke, little is known about the natural history, and no guidelines exist for screening and management of NF1-associated MMS.

Methods: We identified 152 literature cases of children aged ≤18 years with NF1-associated MMS.

R-Ras subfamily proteins elicit distinct physiologic effects and phosphoproteome alterations in neurofibromin-null MPNST cells.

Background: Loss of the Ras GTPase-activating protein neurofibromin promotes nervous system tumor pathogenesis in patients with neurofibromatosis type 1 (NF1). Neurofibromin loss potentially hyperactivates classic Ras (H-Ras, N-Ras, K-Ras), M-Ras, and R-Ras (R-Ras, R-Ras2/TC21) subfamily proteins. We have shown that classic Ras proteins promote proliferation and survival, but not migration, in malignant peripheral nerve sheath tumor (MPNST) cells.

Defining Gene Functions in Tumorigenesis by Ex vivo Ablation of Floxed Alleles in Malignant Peripheral Nerve Sheath Tumor Cells.

The development of new drugs that precisely target key proteins in human cancers is fundamentally altering cancer therapeutics. However, before these drugs can be used, their target proteins must be validated as therapeutic targets in specific cancer types. This validation is often performed by knocking out the gene encoding the candidate therapeutic target in a genetically engineered mouse (GEM) model of cancer and determining what effect this has on tumor growth.

Establishment and genomic characterization of a sporadic malignant peripheral nerve sheath tumor cell line.

Malignant peripheral nerve sheath tumors (MPNSTs) are aggressive Schwann cell-derived neoplasms that occur sporadically or in patients with neurofibromatosis type 1 (NF1). Preclinical research on sporadic MPNSTs has been limited as few cell lines exist. We generated and characterized a new sporadic MPNST cell line, 2XSB, which shares the molecular and genomic features of the parent tumor.

ErbB4 promotes malignant peripheral nerve sheath tumor pathogenesis via Ras-independent mechanisms.

Background: We have found that erbB receptor tyrosine kinases drive Ras hyperactivation and growth in NF1-null malignant peripheral nerve sheath tumors (MPNSTs). However, MPNSTs variably express multiple erbB receptors with distinct functional characteristics and it is not clear which of these receptors drive MPNST pathogenesis. Here, we test the hypothesis that altered erbB4 expression promotes MPNST pathogenesis by uniquely activating key cytoplasmic signaling cascades.

Mice with missense and nonsense NF1 mutations display divergent phenotypes compared with human neurofibromatosis type I.

Neurofibromatosis type 1 (NF1) is a common genetic disorder characterized by the occurrence of nerve sheath tumors and considerable clinical heterogeneity. Some translational studies have been limited by the lack of animal models available for assessing patient-specific mutations. In order to test therapeutic approaches that might restore function to the mutated gene or gene product, we developed mice harboring NF1 patient-specific mutations including a nonsense mutation (c.

Reversible improvement in severe freezing of gait from Parkinson's disease with unilateral interleaved subthalamic brain stimulation.

Freezing of gait causes considerable morbidity in patients with Parkinson's disease and is often refractory to conventional treatments. In this double-blind, randomized evaluation, unilateral interleaved deep brain stimulation in the subthalamic nucleus/substantia nigra pars reticulata region significantly improved freezing of gait in a patient with advanced Parkinson's disease.

Classic Ras Proteins Promote Proliferation and Survival via Distinct Phosphoproteome Alterations in Neurofibromin-Null Malignant Peripheral Nerve Sheath Tumor Cells.

Neurofibromin, the tumor suppressor encoded by the neurofibromatosis type 1 (NF1) gene, potentially suppresses the activation of H-Ras, N-Ras, and K-Ras. However, it is not known whether these classic Ras proteins are hyperactivated in NF1-null nerve sheath tumors, how they contribute to tumorigenesis, and what signaling pathways mediate their effects. Here we show that H-Ras, N-Ras, and K-Ras are coexpressed with their activators (guanine nucleotide exchange factors) in neurofibromin-null malignant peripheral nerve sheath tumor (MPNST) cells, and that all 3 Ras proteins are activated.

Combinatorial therapy with tamoxifen and trifluoperazine effectively inhibits malignant peripheral nerve sheath tumor growth by targeting complementary signaling cascades.

Chemotherapeutic agents effective against malignant peripheral nerve sheath tumors (MPNSTs) are urgently needed. We recently found that tamoxifen potently impedes xenograft growth. In vitro, tamoxifen inhibits MPNST proliferation and survival in an estrogen receptor-independent manner; these effects are phenocopied by the calmodulin inhibitor trifluoperazine.

Neuregulin-1 overexpression and Trp53 haploinsufficiency cooperatively promote de novo malignant peripheral nerve sheath tumor pathogenesis.

Malignant peripheral nerve sheath tumors (MPNSTs) are Schwann cell-derived malignancies that arise from plexiform neurofibromas in patients with mutation of the neurofibromin 1 (NF1) gene. We have shown that the growth factor neuregulin-1 (NRG1) also contributes to human neurofibroma and MPNST pathogenesis and that outbred C57BL/6J × SJL/J transgenic mice overexpressing NRG1 in Schwann cells (P0-GGFβ3 mice) recapitulate the process of neurofibroma-MPNST progression. However, it is unclear whether NRG1 acts predominantly within NF1-regulated signaling cascades or instead activates other essential cascades that cooperate with NF1 loss to promote tumorigenesis.