[CD20-positive T cell lymphoma: clinicopathological features of five cases]

Objective: To investigate the clinicopathological characteristics of the T cell lymphomas with CD20 expression, and to better understand this rare entity. Methods: Two-hundred cases of T-cell lymphoma diagnosed in the Department of Pathology of the Affiliated Hospital of Qingdao University from November 2016 to February 2020 were examined, and 5 cases of CD20-positive T-cell lymphomas were identified and included. Combined with clinical data and review of the literature, the clinicopathological characteristics of the disease were analyzed. Results: The five patients were all male, and had an average age of 56 years (range, 47 to 64 years). There were 2 cases of monomorphic epitheliotropic intestinal T-cell lymphoma, 2 cases of mycosis fungoides (1 case was plaque stage and the other was tumor stage) and 1 case of indolent T-cell lymphoproliferative disorder of the gastrointestinal tract. Immunohistochemistry showed that all 5 cases expressed multiple T cell markers (CD3/CD4/CD5/CD7/CD8) and only one of B cell markers (CD20). Three of the 5 cases were negative for CD20 at the first diagnosis, while CD20 was diffusely positive on the second biopsy from the recurrence or progression of the disease, without expression of CD79a or PAX5. Epstein-Barr encoding region (EBER) in situ hybridization was negative in all 5 cases. T-cell receptor gene analysis showed monoclonal rearrangement of β or/and δ chains;Ig rearrangements were all polyclonal. None of the five patients were treated with rituximab, and 4 patients survived with disease and 1 patient survived without disease at the end of follow-up. Among them, the patient with mycosis fungoides at the cancerous stage has progressed rapidly and had poor quality of life. Conclusions: CD20-positive T-cell lymphoma is extremely rare. Its prognosis is closely related to the type of T-cell lymphoma, clinical stage and initial therapeutic effect. However, the expression of CD20 indicates the recurrence or progression of the disease, and the prognosis is relatively poor. When CD3 expression is absent in T-cell lymphoma, it is easy to be misdiagnosed as B-cell lymphoma. The combination of multiple immunohistochemical antibodies and molecular detection can improve the accuracy of diagnosis.

Symbiotic characteristics of Bradyrhizobium diazoefficiens USDA 110 mutants associated with shrubby sophora (Sophora flavescens) and soybean (Glycine max)

Site-specific insertion plasmid pVO155 was used to knockout the genes involved in the alternation of host range of strain Bradyrhizobium diazoefficiens USDA 110 from its original determinate-nodule-forming host soybean (Glycine max), to promiscuous and indeterminate-nodule-forming shrubby legume sophora (Sophora flavescens). Symbiotic phenotypes of these mutants inoculated to these two legumes, were compared to those infected by wild-type strain USDA 110. Six genes of the total fourteen Tn5 transposon mutated genes were broken using the pVO155 plasmid. Both Tn5 and pVO155-inserted mutants could nodulate S. flavescens with different morphologies of low-efficient indeterminate nodules. One to several rod or irregular bacteroids, containing different contents of poly-β-hydroxybutyrate or polyphosphate were found within the symbiosomes in nodulated cells of S. flavescens infected by the pVO155-inserted mutants. Moreover, none of bacteroids were observed in the pseudonodules of S. flavescens, infected by wild-type strain USDA 110. These mutants had the nodulation ability with soybean but the symbiotic efficiency reduced to diverse extents. These findings enlighten the complicated interactions between rhizobia and legumes, i. e., mutation of genes involved in metabolic pathways, transporters, chemotaxis and mobility could alter the rhizobial entry and development of the bacteroid inside the nodules of a new host legume.

Comparison of different fabrication techniques used for processing 3-dimensional, porous, biodegradable scaffolds from modified starch for bone tissue engineering

3 dimensional, porous, biodegradable scaffolds were fabricated using modified starch of varying degree of substitution (DS) by extrusion processing. Freeze drying/lyophilization was also employed to fabricate scaffolds from modified starch. The research efforts have been focused on the comparison of the above-mentioned techniques by comparing the properties of the fabricated scaffolds in the paradigm of bone tissue engineering. The physicomechanical properties like porosity, compressive strength and modulus, pore size and microstructure were tested and analyzed by liquid replacement, mechanical testing and scanning electron microscopy respectively. The biodegradability of scaffolds was evaluated by soaking the samples in aqueous medium and Hank's balanced salt solution at 37-degree invitro. The cytotoxicity studies on these scaffolds were also conducted. The scaffolds have a 3D structure consisting of interconnected pores with good porosity, pore size, adequate compressive strength and modulus and exhibit good biodegradability as well as biocompatibility. After further optimization in the processing conditions and parameters they could be made useful for bone tissue engineering.