Solitary plasmacytoma of the mesentery with nodular amyloid deposits: a case report with immunohistochemical evaluation

The mesentery is unusual site for plasmacytoma. We have observed a solitary primary mesenteric plasmacytoma with marked nodular deposits of Congophilic amyloid in a 38 year-old man. We believe the present case represents the first case of primary extraosseous mesenteric plasmacytoma in the English literature. The clinical picture, pathologic findings and immuno-histochemical studies are discussed. Autopsy and long-term follow up are needed to determine whether this patient is at risk of developing multiple myeloma, local recurrence, metastatic foci or probable complications related to amyloidosis.     

Experiences of introducing new drugs for drug-resistant TB at the ALERT Hospital,Addis Ababa,Ethiopia, 2017–2019

BACKGROUND:Drug-resistant TB (DR-TB) remains a major public health concern. DR-TB patient data from ALERT (All Africa Leprosy, Tuberculosis and Rehabilitation Training Centre) Hospital, Addis Ababa, Ethiopia, who received bedaquiline (BDQ) and/or delamanid (DLM) containing regimens were analysed.RESULTS:From 2017 to 2019, 51 DR-TB patients were enrolled. Of 33 patients, 31 (93.9%) had culture converted at 6 months. Of those with final outcomes, 77% (n = 10) were cured. Thirty (58.8%) developed adverse events, the most frequent of which were gastrointestinal disorders (70%), haematological disorders (16.7%) and QTc prolongation (16.7%). Twenty patients discontinued the offending drug permanently.CONCLUSION:With close monitoring, introduction of new DR-TB regimens brought good early results, which encouraged wider programmatic implementation in Ethiopia.     

Optimizing a 3D model system for molecular manipulation of tenogenesis

Purpose: Tendon injuries are clinically challenging due to poor healing. A better understanding of the molecular events that regulate tendon differentiation would improve current strategies for repair. The mouse model system has been instrumental to tendon studies and several key molecules were initially established in mouse. However, the study of gene function has been limited by the absence of a standard in vitro tendon system for efficiently testing multiple mutations, physical manipulations, and mis-expression. The purpose of this study is therefore to establish such a system.Methods: We adapted an existing design for generating three-dimensional (3D) tendon constructs for use with mouse progenitor cells harboring the ScxGFP tendon reporter and the Rosa26-TdTomato Cre reporter. Using these cells, we optimized the parameters for construct formation, inducing tenogenesis via transforming growth factor-β2 (TGFβ2), and genetic recombination via an adenovirus encoding Cre recombinase. Finally, for proof of concept, we used Smad4 floxed cells and tested the robustness of the system for gene knockdown.Results: We found that TGFβ2 treatment induced a tenogenic phenotype depending on the timing of initiation. Addition of TGFβ2 after 3D “tensioning” enhanced tendon differentiation. Interestingly, while TGFβ2-induced proliferation depended on Smad4, tenogenic parameters such as ScxGFP expression and fibril diameter were independent of Smad4.Conclusions: Our results demonstrate the feasibility of this optimized system for harnessing the power of mouse genetics for in vitro applications.