A rare variant of the superficial ulnar artery, and its clinical implications: a case report

The superficial ulnar artery is a rare variation of the upper limb arterial system that arises from the brachial or axillary artery and runs superficial to the muscles arising from the medial epicondyle [1-3]. The incidence is about 0.7 to 7% [1,4,5]. In our routine dissections we found a superficial ulnar artery, which crossed the cubital fossa superficial to the bicipital aponeurosis making it highly vulnerable to intra-arterial injection. This is a rare variation that every medical and nursing staff member should know about

Wnt5a induces ROR1 to complex with HS1 to enhance migration of chronic lymphocytic leukemia cells.

ROR1 (receptor tyrosine kinase-like orphan receptor 1) is a conserved, oncoembryonic surface antigen expressed in chronic lymphocytic leukemia (CLL). We found that ROR1 associates with hematopoietic-lineage-cell-specific protein 1 (HS1) in freshly isolated CLL cells or in CLL cells cultured with exogenous Wnt5a. Wnt5a also induced HS1 tyrosine phosphorylation, recruitment of ARHGEF1, activation of RhoA and enhanced chemokine-directed migration; such effects could be inhibited by cirmtuzumab, a humanized anti-ROR1 mAb. We generated truncated forms of ROR1 and found its extracellular cysteine-rich domain or kringle domain was necessary for Wnt5a-induced HS1 phosphorylation. Moreover, the cytoplamic, and more specifically the proline-rich domain (PRD), of ROR1 was required for it to associate with HS1 and allow for F-actin polymerization in response to Wnt5a. Accordingly, we introduced single amino acid substitutions of proline (P) to alanine (A) in the ROR1 PRD at positions 784, 808, 826, 841 or 850 in potential SH3-binding motifs. In contrast to wild-type ROR1, or other ROR1P→︀A mutants, ROR1P(841)A had impaired capacity to recruit HS1 and ARHGEF1 to ROR1 in response to Wnt5a. Moreover, Wnt5a could not induce cells expressing ROR1P(841)A to phosphorylate HS1 or activate ARHGEF1, and was unable to enhance CLL-cell motility. Collectively, these studies indicate HS1 plays an important role in ROR1-dependent Wnt5a-enhanced chemokine-directed leukemia-cell migration

Differential Prox-1 and CD 31 expression in mucousae, cutaneous and soft tissue vascular lesions and tumors

The study of lymphatic vessels and lymphatic tumors has been hampered with difficulty due to the overlapping morphological features between blood and lymphatic endothelial cells, as well as to the lack of specific lymphatic endothelial markers. Over the last few years, lymphatic vessels and lymphangiogenesis have received great attention owing to their putative implications in terms of metastatic dissemination and the promise of targets for lymphangiogenic therapy. Prox-1 is a nuclear transcription factor that plays a major role during embryonic lymphangiogenesis and is deemed to be a useful marker for differentiating lymphatic endothelial cells from the other blood vessels endothelial cells. Here, we describe a double-immunostaining strategy for formalin-fixed, paraffinembedded tissues that aims at evaluating the distribution of Prox-1 and CD 31 – a cytoplasmic pan-endothelial marker -in a series of 28 mucousae, cutaneous and soft tissue vascular lesions and tumors, including hemangiomas, lymphangiomas, lymphangiectasia, and Kaposi’s sarcomas. Our results showed that in non-lesional mucousae and skin, Prox-1 decorated exclusively the nuclei of endothelial cells in lymphatic vessels. Prox-1 stained almost all the benign lymphatic vascular lesions/tumors (91%) and was absent or only focally positive in 75% of blood vascular tumors. CD 31 stained endothelial cells of blood vessels of superficial and deep dermal plexuses, lymphatics, and all blood vascular lesions/tumors. Kaposi’s sarcomas were all positive for both CD 31 and Prox-1 markers. In conclusion, although Prox-1 expression in vascular lesions/tumors was not entirely restricted to tumors with known lymphatic differentiation, CD 31/Prox-1 double-immunolabeling can be used as an adjunct marker to identify lymphatic vessels in routinely processed formalin-fixed, paraffin-embedded samples