MR imaging of clear cell sarcoma (malignant melanoma of the soft parts): A multicenter correlative MRI-pathology study of 21 cases and literature review

Objective. To evaluate MR imaging and pathology findings in order to define the characteristic features of clear cell sarcoma of the soft tissues (malignant melanoma of the soft parts). Design and patients. MR examinations of 21 patients with histologically proven clear cell sarcoma of the musculoskeletal system were retrospectively reviewed and assessed for shape, homogeneity, delineation, signal intensities on T1- and T2-weighted images, contrast enhancement, relationship with adjacent fascia or tendon, secondary bone involvement, and intratumoral necrosis. In 19 cases the pathology findings were available for review and for a comparative MR-pathology study. Results. On T1-weighted images, lesions were isointense (n=3), hypointense (n=7) or slightly hyperintense to muscle (n=11). Immunohistochemical examination was performed in 17 patients. All 17 specimens showed positivity for HMB-45 antibody. In nine of 11 lesions with slightly increased signal intensity on T1-weighted images, a correlative MR imaging-pathology study was possible. All nine were positive to HMB-45 antibody. Conclusions. Clear cell sarcoma of the musculoskeletal system often has a benign-looking appearance on MR images. In up to 52% of patients, this lesion with melanocytic differentiation has slightly increased signal intensity on T1-weighted images compared with muscle. As the presence of this relative higher signal intensity on T1-weighted images is rather specific for tumors displaying melanocytic differentiation, radiologists should familiarize themselves with this rare entity and include it in their differential diagnosis when confronted with a well- defined, homogeneous, strongly enhancing mass with slightly higher signal intensity compared with muscle on native T1-weighted images

Cloning and expression in Escherichia coli of the TL-DNA gene 4 of Agrobacterium tumefaciens under the control of the PR promoter of bacteriophage λ

A plasmid was constructed that directs expression of the TL-DNA gene 4 protein in E. coli. The different steps of the construction were as follows: i) a region of gene 4 encoding the amino-terminal portion of the protein was fused in frame to DNA encoding an enzymatically active carboxy-terminal fragment of beta-galactosidase. The hybrid gene was poorly expressed from the upstream lambda PL promoter carried by the vector. ii) in order to generate an efficient procaryotic ribosome binding site, a DNA fragment carrying the lambda PR promoter with the nearby Shine-Dalgarno (SD) sequence of gene cro was placed in front of the gene 4-lacZ fusion. A recombinant plasmid, termed pGV793, that expressed efficiently a fused protein 4-beta-galactosidase was identified among the Lac+ clones. DNA sequencing analysis showed that pGV793 carried a hybrid ribosome binding site composed of the cro SD sequence, a five bp sequence and the ATG codon of gene 4. Plasmid pGV793 directed the synthesis of three polypeptides of molecular weight 132 Kd, 126 Kd and 122 Kd that carried beta-galactosidase antigenic determinants. The largest polypeptide had the expected size for the hybrid protein. The fusion proteins which accounted for about 0.5% of the total cellular proteins were purified by immunoadsorption using anti-beta-galactosidase antiserum. iii) the complete gene 4 coding sequence was reconstituted, with the lambda PR promoter in place. The resulting pGV822 plasmid expressed a polypeptide whose molecular weight 27 Kd corresponded to the expected size for the gene 4 product. The pI was about 7

Further insight on the transferred-DNA of octopine crown gall

Six octopine tumour lines incited by pTiB6S3, pTiAch5 and pTiA6 on tobacco, Arabidopsis and Petunia were studied by the Southern blotting hybridisation technique in order to define accurately the dimensions of the segments of plasmid origin transferred to the tumourous cell and their organisation in the plant genome. Emphasis has been put on the comparison between octopine and nopaline T-DNAs and on the lines presented here compared with those studied previously (Thomashow et al. 1980). The lenght of the transferred DNA segment does not depend on the plasmids used, nor on the host plants. The octopine T-DNA organisation in the cell nucleus is significantly different from that of nopaline T-DNAs: tandem arrangements of T-DNA segments could not be detected and the T-DNA itself is much shorter. The tumour lines described here can be compared to some extent with those studied by another group (Thomashow et al. 1980) by the same technique. However, some differences were observed. The transferred DNA was seen as a unique stretch of about 11 kb present only once per cell. No amplification of any part was noticed in any of these six lines. Examination of the restriction patterns presented by the boundary fragments of the T-DNA in these lines suggested that some of them were of common origin

Atraumatic bilateral scapular spine fracture several months after bilateral reverse total shoulder arthroplasty

We report an 89-year-old woman with bilateral atraumatic scapular spine fracture several months after bilateral reverse total shoulder arthroplasty (RTSA). Recently, RTSA has gained popularity in the surgical treatment of complex shoulder disorders such as cuff tear arthropathy. However, scapular fractures may occur several months after surgery as a late complication of this procedure. In this case report we focus on a relatively uncommon subtype, the scapular spine fracture. Although well-known in the orthopedic literature, radiologists are less familiar with this complication. To the best of our knowledge, bilateral scapular fractures have not yet been reported