Purification and Characterization of a Methyl-DNA Binding Protein Complex from Primary Erythroid Cells

The chicken embryonic β-type globin gene, ρ, is silenced on day five of embryogenesis. Concomitant with this silencing is methylation of cytosine residues in the promoter and proximal transcribed region of the gene, which is first detected on day seven and is complete in adult cells. Once methylated, expression of the gene cannot be induced unless the methylation is removed by treatment of cells with Sazacytidine. Therefore ρ-globin is a member of a small group of genes whose normal developmentally regulated expression is mediated at least in part by DNA methylation.A methyl-DNA binding complex, termed the MeCPC (Erythroid Methyl Cytosine-binding Protein Complex), has been found to bind to the methylated, but not unmethylated, ρ-globin promoter and proximal transcribed region in nuclear extracts from definitive erythrocytes. This complex has a stronger binding affinity for its cognate binding sequence, the methylated ρ-globin proximal transcribed region (M-ρ248), than for an artificial 5-methylcytosine-rich sequence (M-CG11).To define the components of the MeCPC, we developed two chromatographic procedures to purify the complex from adult chicken red blood cell nuclear extracts (Purification Strategies I and II). Mass spectrometry was performed on the MeCPC obtained by Purification Strategy I and proteins were identified by a novel application of peptide mass fingerprint data fitting. Four components of the previously-purified MeCPl transcriptional repression complex were identified in the sample: MBD2, RbAp48, HDAC2 and MTA1. Another identified protein, MENT, is a factor expressed only in chicken hematopoietic cells. These five proteins, as well as the MeCPl component Mi2, were found to tightly coelute by Western blotting of gel-filtration fractions from Purification Strategy II. Therefore, we conclude that these five proteins are components of the MeCPC.To confirm that MBD2 is associated with the ρ-globin gene in vivo, we perfomed the chromatin immunoprecipitation assay using anti-MBD2 antibodies. In adult erythrocytes, significant enrichment for MBD2 is seen at the transcriptionally inactive ρ-globin gene, but no enrichment is observed at the transcriptionally active βA globin gene. These experiments confirm that MBD2 binds to the methylated p-globin gene in adult chicken erythroid cells

Various Tumor-Mimicking Lesions in the Musculoskeletal System: Causes and Diagnostic Approach

Tumor-mimicking lesions in the musculoskeletal system can be defined as lesions mistaken as tumors due to the presence of palpation upon physical examination or a tumor-like appearance upon radiological examination. Moreover, tumor-mimicking lesions show diverse etiologies and anatomic locations. We illustrated the various tumor-mimicking lesions involving bone and soft tissue. In this review, the tumor-mimicking lesions were classified into those based on clinical examination and those based on radiological examination in musculoskeletal radiology. Awareness of the various causes of tumor-mimicking lesions, correctly obtaining clinical information, and the proper selection of imaging modality are important for the differentiation of tumor-mimicking lesions from true neoplasms

Symmetric Lipofibromatous Hamartoma Affecting Digital Nerves

Lipofibromatous hamartoma of the nerve is a benign tumor, which affects the major nerves and their branches in the human body. It is often found in the median nerve of the hand and is commonly associated with macrodactyly, but it is rarely found in the digital nerves at the peripheral level. This tumor is often found in young adults and may go through a self-limiting course. However, operation is indicated when the tumor size is large or when the associated nerve compressive symptoms are present. We have experienced a rare case of lipofibromatous hamartoma that symmetrically involved the volar digital nerves of both index fingers on the ulnar side. With the aid of a microscope, we dissected and removed the tumor as much as possible without sacrificing the nerve. No sensory change occurred in both fingers and no sign of recurrence was observed upon follow-up

Nodular Fasciitis with Cortical Erosion of the Hand

Nodular fasciitis is a benign, reactive myofibroblastic tumor that is often mistaken for a sarcoma because of its histological appearance and rapid growth. Involvement of a finger is extremely rare. We report a case of nodular fasciitis of the thumb, accompanied by bone erosion. Magnetic resonance findings suggested the possibility of a malignancy, which could have led to misdiagnosis as a malignant soft tissue sarcoma. Instead, the lesion was treated by excisional biopsy, which confirmed nodular fasciitis. There has been no evidence of local recurrence at recent follow-up, 1 year after surgery. This case illustrates that, to avoid unnecessarily aggressive surgery, nodular fasciitis must be included in the differential diagnosis for any finger lesion that resembles a sarcoma, even if bone erosion is present

Giant Cell Tumor of Soft Tissue: a Case with Atypical US and MRI Findings

We report the case of a giant cell tumor with diffuse interstitial hemorrhaging and unusually prominent cystic components in the soft tissue of the thigh which has not been reported previously. Magnetic resonance image (MRI), showed signal intensity typical of a giant cell tumor. However, because of its conspicuous large well-circumscribed cystic components, the differential diagnoses, based on the image findings from an ultrasonography (US) and MRI, were complicated epidermoid cyst, cystic change of a neurogenic tumor, and a parasitic cyst

Comparisons among computed tomographic features of adipose masses in dogs and cats

A better understanding of the CT features of different forms of canine and feline adipose tumors would be valuable for improving patient management and treatment. The purpose of this retrospective, cross-sectional study was to describe and compare the CT features of pathologically confirmed lipomas, infiltrative lipomas, and liposarcomas in a sample of canine and feline patients. A total of 50 animals (46 dogs, four cats) and a total of 60 lesions (23 lipomas, 20 infiltrative lipomas, and 17 liposarcomas) were included in the study. Lipomas appeared as round to oval-shaped (n = 21), well-marginated (n = 20) fat-attenuating lesions. Infiltrative lipomas appeared as homogeneous, fat-attenuating masses but, unlike lipomas, they were most commonly characterized by an irregular shape (75%; P < 0.001), and linear components, hyperattenuating relative to the surrounding fat (100%; P < 0.05). Liposarcomas were represented exclusively by heterogeneous lesions with soft tissue attenuating components with a multinodular appearance (76.5%; P < 0.05). Regional lymphadenopathy (n = 10) and amorphous mineralization (n = 4) were also observed in association with liposarcomas. Computed tomography can provide useful information regarding disease location, extent, and involvement of the adjacent structures. Tumor definition and shape were the most useful parameters to differentiate between lipomas and infiltrative lipomas. The presence of a heterogeneous mass, with a multinodular soft tissue component and associated regional lymphadenopathy and mineralization, were features favoring a diagnosis of liposarcoma

Do quantitative and qualitative shear wave elastography have a role in evaluating musculoskeletal soft tissue masses?

Objectives: To determine if quantitative and qualitative shear wave elastography have roles in evaluating musculoskeletal masses. Methods: 105 consecutive patients, prospectively referred for biopsy within a specialist sarcoma centre, underwent B-mode, quantitative (m/s) and qualitative (colour map) shear wave elastography. Reference was histology from subsequent biopsy or excision where possible. Statistical modelling was performed to test elastography data and/or B-mode imaging in predicting malignancy. Results: Of 105 masses, 39 were malignant and 6 had no histology but benign characteristics at 12 months. Radiologist agreement for B-mode and elastography was moderate to excellent Kw 0.52-0.64; PABAKw 0.85-0.90). B-Mode imaging had 78.8% specificity, 76.9% sensitivity for malignancy. Quantitatively, adjusting for age, B-mode and lesion volume there was no statistically significant association between longitudinal velocity and malignancy (OR [95% CI] 0.40[0.10, 1.60], p=0.193), but some evidence that higher transverse velocity was associated with decreased odds of malignancy (0.28[0.06, 1.28], p=0.101). Qualitatively malignant masses tended to be towards the blue spectrum (lower velocities); 39.5% (17/43) of predominantly blue masses were malignant, compared to 14.3% (1/7) of red lesions. Conclusions: Quantitatively and qualitatively there is no statistically significant association between shear wave velocity and malignancy. There is no clear additional role to B-mode imaging currently. Key Points: • Correlation between shear wave velocity and soft tissue malignancy was statistically insignificant• B-mode ultrasound is 76.9 % sensitive and 78.8 % specific• Statistical models show elastography does not significantly add to lesion assessmen