39 research outputs found
A high resolution atlas of gene expression in the domestic sheep (Ovis aries)
Sheep are a key source of meat, milk and fibre for the global livestock sector, and an important biomedical model. Global analysis of gene expression across multiple tissues has aided genome annotation and supported functional annotation of mammalian genes. We present a large-scale RNA-Seq dataset representing all the major organ systems from adult sheep and from several juvenile, neonatal and prenatal developmental time points. The Ovis aries reference genome (Oar v3.1) includes 27,504 genes (20,921 protein coding), of which 25,350 (19,921 protein coding) had detectable expression in at least one tissue in the sheep gene expression atlas dataset. Network-based cluster analysis of this dataset grouped genes according to their expression pattern. The principle of 'guilt by association' was used to infer the function of uncharacterised genes from their co-expression with genes of known function. We describe the overall transcriptional signatures present in the sheep gene expression atlas and assign those signatures, where possible, to specific cell populations or pathways. The findings are related to innate immunity by focusing on clusters with an immune signature, and to the advantages of cross-breeding by examining the patterns of genes exhibiting the greatest expression differences between purebred and crossbred animals. This high-resolution gene expression atlas for sheep is, to our knowledge, the largest transcriptomic dataset from any livestock species to date. It provides a resource to improve the annotation of the current reference genome for sheep, presenting a model transcriptome for ruminants and insight into gene, cell and tissue function at multiple developmental stages
Solitary Fibrous Tumour of Thyroid: Report of Two Cases with Immunohistochemical Features and Literature Review
Solitary fibrous tumour (SFT) is a rare tumour principally found in adults in the pleural cavity. Extrapleural occurrences are rare. Two cases of SFT of the thyroid gland are described in this paper showing their distinctive microscopical architecture, namely “patternless growth pattern”. It is characterized by a bland spindle-cell proliferation alternating hyper- and hypo-cellular areas, keloid-like hyalinization and a focal hemangiopericytoma-like vascular pattern. Tumour cells revealed a diffuse strong positivity for CD34, CD99, bcl-2 and Vimentin, but negativity for Desmin, EMA, AE1/AE3, SMA, S-100 and CD31 antibodies. The differential diagnosis of thyroid SFT includes different types of spindle cell proliferation, benign and malignant mesenchymal tumours, medullary thyroid carcinoma, fasciitis-like papillary carcinoma, and undifferentiated (anaplastic) carcinoma. However, the morphologic and immunohistochemical findings of SFT are so characteristic that this diagnosis seldom represent a difficulty
Orbital Infantile Myofibroma: a Case Report and Clinicopathologic Review of 24 Cases from the Literature
Isolated orbital infantile myofibroma are rare tumors in the head and neck. The mass-like clinical presentation and variable histologic features result in frequent misdiagnosis and potentially inappropriate clinical management. There are only a few reported cases in the English literature. Twenty-four patients with orbital infantile myofibroma or myofibromatosis were compiled from the English literature (Medline 1960–2011) and integrated with this case report. The patients included 14 males and 10 females, aged newborn to 10 years (mean, 34.8 months), who presented with a painless mass in the infra- or supraorbital regions, usually increasing in size andassociated with exophthalmos (n = 5). Females were on average older than their male counterparts (38.9 vs. 31.9 months, respectively; P = 0.71). The tumors were twice as frequent on the left (n = 16) than right (n = 8). Patients experienced symptoms for an average of 2.7 months before clinical presentation. The tumors involved the bone (n = 17) or the soft tissues (n = 7) of the orbit, with extension into the nasal or oral cavity (n = 3). The mean size was 3.0 cm, with a statistically significant difference between males and females (mean: 3.9 vs. 1.82; P = 0.0047), but without any differences based on age at presentation (P = 0.25), duration of symptoms (P = 0.66), or bone or soft tissue involvement (P = 0.51). Grossly, all tumors were well-circumscribed, firm to rubbery, homogenous, and white–grey. Histologically, the tumors were biphasic, showing whorled and nodular areas of fusiform cells with extracellular collagen, mixed with a population of small, primitive-appearing, darkly staining cells. Necrosis was not present, but mitoses could be seen. Tumors with immunohistochemistry performed showed strong and diffuse smooth muscle actin and vimentin immunoreactivity, but were negative with muscle specific actin, desmin, MYOD1, myogenin, S100 protein, GFAP, keratin, CD31, 34, Factor VIIIR-Ag, and CD45RB. The principle histologic differential diagnosis includes juvenile hyaline fibromatosis, fibrous hamartoma of infancy, fibromatosis coli, leiomyoma, infantile hemangiopericytoma, infantile fibrosarcoma, Ewing sarcoma/primitive neuroectodermal tumor, and lymphoma. All patients were managed with surgery. Recurrences developed in two patients at 4 and 6 months, respectively. Follow-up data was available on all but two patients (n = 22). These patients were either alive without evidence of disease (n = 18), alive but with disease (n = 3), or had died unrelated to this disease (i.e., neuroblastoma, n = 1). Orbital infantile myofibroma is a rare tumor, presenting in infancy as an enlarging mass of the orbit, with characteristic histomorphologic and immunophenotypic features. Orbital disease is usually isolated rather than part of systemic disease, and shows an excellent long-term prognosis, making appropriate separation from other conditions important