Atypical clinical presentation and long-term survival in a patient with optic nerve medulloepithelioma: a case report

<p>Abstract</p> <p>Introduction</p> <p>Medulloepithelioma is a rare congenital tumor of the primitive medullary neuroepithelium. A significant proportion of patients with medulloepithelioma arising from the optic nerve die from intracranial spread or cerebral metastasis. Because it has no known distinct clinical features and because of its low frequency, this tumor presents within the first two to six years of life and is usually misdiagnosed clinically as a different type of optic nerve tumor. Here, we describe a new and atypical case of medulloepithelioma of the optic nerve in a 12-year-old boy. To the best of our knowledge, he is the oldest reported patient to present with this disease and, now as an adult, has the longest documented period of disease-free survival.</p> <p>Case presentation</p> <p>A 12-year-old Caucasian boy with headache and unilateral amaurosis was referred for a presumed optic nerve glioma to our hospital. A computed tomography scan showed optic nerve enlargement, and fundoscopy showed a whitish mass at the optic disc. Our patient had been followed at his local hospital for four years for an 'optic disc cyst' with no change or progression. He experienced mild progressive visual impairment during that period. He was admitted for resection, and a histopathological analysis revealed a medulloepithelioma of the optic nerve. Supplemental orbital radiotherapy was performed. He remained disease-free for 25 years.</p> <p>Conclusions</p> <p>Medulloepithelioma of the optic nerve can clinically mimic more common pediatric tumors, such as optic glioma, meningioma, or retinoblastoma. Thus, medulloepithelioma should be included in the differential diagnoses of pediatric optic nerve lesions. Fundoscopy in these patients may provide relevant information for diagnosis. Anterior optic nerve medulloepitheliomas may behave differently from and have a better prognosis than medulloepitheliomas that have a more posterior location. Our case report illustrates that long-term survival can be achieved in patients with this malignant tumor.</p

Genome Analysis of Planctomycetes Inhabiting Blades of the Red Alga

Porphyra is a macrophytic red alga of the Bangiales that is important ecologically and economically. We describe the genomes of three bacteria in the phylum Planctomycetes (designated P1, P2 and P3) that were isolated from blades of Porphyra umbilicalis (P.um.1). These three Operational Taxonomic Units (OTUs) belong to distinct genera; P2 belongs to the genus Rhodopirellula, while P1 and P3 represent undescribed genera within the Planctomycetes. Comparative analyses of the P1, P2 and P3 genomes show large expansions of distinct gene families, which can be widespread throughout the Planctomycetes (e.g., protein kinases, sensors/response regulators) and may relate to specific habitat (e.g., sulfatase gene expansions in marine Planctomycetes) or phylogenetic position. Notably, there are major differences among the Planctomycetes in the numbers and sub-functional diversity of enzymes (e.g., sulfatases, glycoside hydrolases, polysaccharide lyases) that allow these bacteria to access a range of sulfated polysaccharides in macroalgal cell walls. These differences suggest that the microbes have varied capacities for feeding on fixed carbon in the cell walls of P.um.1 and other macrophytic algae, although the activities among the various bacteria might be functionally complementary in situ. Additionally, phylogenetic analyses indicate augmentation of gene functions through expansions arising from gene duplications and horizontal gene transfers; examples include genes involved in cell wall degradation (e.g., κ-carrageenase, alginate lyase, fucosidase) and stress responses (e.g., efflux pump, amino acid transporter). Finally P1 and P2 contain various genes encoding selenoproteins, many of which are enzymes that ameliorate the impact of environmental stresses that occur in the intertidal habitat

Thousands of Rab GTPases for the Cell Biologist

Rab proteins are small GTPases that act as essential regulators of vesicular trafficking. 44 subfamilies are known in humans, performing specific sets of functions at distinct subcellular localisations and tissues. Rab function is conserved even amongst distant orthologs. Hence, the annotation of Rabs yields functional predictions about the cell biology of trafficking. So far, annotating Rabs has been a laborious manual task not feasible for current and future genomic output of deep sequencing technologies. We developed, validated and benchmarked the Rabifier, an automated bioinformatic pipeline for the identification and classification of Rabs, which achieves up to 90% classification accuracy. We cataloged roughly 8.000 Rabs from 247 genomes covering the entire eukaryotic tree. The full Rab database and a web tool implementing the pipeline are publicly available at www.RabDB.org. For the first time, we describe and analyse the evolution of Rabs in a dataset covering the whole eukaryotic phylogeny. We found a highly dynamic family undergoing frequent taxon-specific expansions and losses. We dated the origin of human subfamilies using phylogenetic profiling, which enlarged the Rab repertoire of the Last Eukaryotic Common Ancestor with Rab14, 32 and RabL4. Furthermore, a detailed analysis of the Choanoflagellate Monosiga brevicollis Rab family pinpointed the changes that accompanied the emergence of Metazoan multicellularity, mainly an important expansion and specialisation of the secretory pathway. Lastly, we experimentally establish tissue specificity in expression of mouse Rabs and show that neo-functionalisation best explains the emergence of new human Rab subfamilies. With the Rabifier and RabDB, we provide tools that easily allows non-bioinformaticians to integrate thousands of Rabs in their analyses. RabDB is designed to enable the cell biology community to keep pace with the increasing number of fully-sequenced genomes and change the scale at which we perform comparative analysis in cell biology