The expressions of MUM-1 and Bcl-6 in ALK-negative systemic anaplastic large cell lymphoma with skin involvement and primary cutaneous anaplastic large cell lymphoma.

BACKGROUND: It is important to differentiate between primary cutaneous anaplastic large cell lymphoma (PC-ALCL) and ALK-negative systemic ALCL with skin involvement, as the prognoses and treatments for these two diseases are considerably different. OBJECTIVE: This study aimed to compare the expressions of multiple myeloma oncogene 1 (MUM-1) and B-cell lymphoma 6 (Bcl-6) in PC-ALCL and ALK-negative systemic ALCL. METHODS: This retrospective qualitative study investigated the clinical features of 7 patients with ALK-negative PC-ALCL, 5 patients with ALK-negative systemic ALCL with skin involvement, and 6 patients with ALK-positive systemic ALCL with skin involvement. The MUM-1 and Bcl-6 expressions were evaluated using immunohistochemistry. RESULTS: The MUM-1 expression rates were 85.7% in the PC-ALCL cases and 100% in the ALK-negative systemic ALCL with skin involvement cases. The Bcl-6 expression rates were 28.5% in the PC-ALCL cases and 20% in the ALK-negative systemic ALCL cases with skin involvement. CONCLUSION: Although the cutaneous manifestations of ALK-negative systemic ALCL and PC-ALCL are similar, the prognoses and treatment approaches are considerably different. Our results indicate that MUM-1 expression is commonly expressed in both types of ALCL, but Bcl-6 is less commonly expressed in PC-ALCL cases and systemic ALCL with skin involvement cases.

Antibiotics-Associated Hemorrhagic Colitis Caused by Klebsiella oxytoca: Two Case Reports.

Nowadays, Klebsiella oxytoca is described as a causative organism for antibiotic-associated hemorrhagic colitis (AAHC). Here we report two cases of pediatric AAHC, from which K. oxytoca was cultured after starting amoxicillin-clavulanate or amoxicillin treatment. The patients developed severe abdominal pain and a large amount of bloody diarrhea. K. oxytoca was obtained in intestinal fluid culture of a boy through the colonoscopy. On the other hand, colonic tissue culture and intestinal fluid culture were negative of the other patient. K. oxytoca was detected in stool culture when he was admitted. These cases showed characteristic endoscopic findings of segmental hemorrhagic colitis, and both boys recovered spontaneously within 2-3 days after they stopped taking the antibiotics. Therefore, in children who develop relatively large amount of bloody diarrhea after antibiotic treatment, we should consider AAHC caused by K. oxytoca.

Clinical features and prognosis of Asian patients with acral lentiginous melanoma who have nodal nevi in their sentinel lymph node biopsy specimen.

BACKGROUND: Nodal melanocytic nevi (NNs) encountered during sentinel lymph node biopsy (SLB) for malignant melanoma are usually difficult to distinguish from metastatic melanoma. However, NNs have not been well studied in acral lentiginous melanoma (ALM) in Asian populations. OBJECTIVE: To investigate the clinical characteristics and significance of NNs in SLB specimens from patients with ALM. METHODS: We retrospectively analyzed 84 patients with ALM who underwent SLB between June 2010 and July 2017. RESULTS: Of the 84 patients with ALM, 9 (10.7%) had NNs in their SLB specimens. NNs were significantly more common in SLB specimens than in specimens not obtained by SLB. The presence of pre-existing melanocytic lesions was found to be associated with NNs (P < .001). The 5-year overall survival was significantly higher in patients with ALM with NNs than in patients with a positive SLB result (P = .047). Distant recurrence in patients with ALM with NNs was significantly lower than in patients a positive SLB result (P = .03). LIMITATIONS: The small sample size, single-center study design, and retrospective nature of the study were the limitations. CONCLUSION: In Asian populations, the prevalence of NNs in ALM is similar to that reported in Europe and the United States. The rates of distant recurrence and overall survival in patients with ALM who have NNs are similar to those of patients who do not have metastatic melanoma.

Adherent cells generated during long-term culture of human umbilical cord blood CD34+ cells have characteristics of endothelial cells and beneficial effect on cord blood ex vivo expansion.

Hematopoiesis depends on the association of hematopoietic stem cells with stromal cells that constitute the hematopoietic microenvironment. The in vitro development of the endothelial cell from umbilical cord blood (UCB) is not well established and has met very limited success. In this study, UCB CD34(+) cells were cultured for 5 weeks in a stroma-free liquid culture system using thrombopoietin, flt3 ligand, and granulocyte-colony stimulating factor. By week 4-5, we found that firmly adherent fibroblast-like cells were established. These cells showed characteristics of endothelial cells expressing von Willebrand factor, human vascular cell adhesion molecule-1, human intracellular adhesion molecule-1, human CD31, E-selectin, and human macrophage. Furthermore, when comparing an ex vivo system without an established endothelial monolayer to an ex vivo system with an established endothelial monolayer, better expansion of total nucleated cells, CD34(+) cells, and colony-forming units (CFUs)-granulocyte-macrophage and CFUs-granulocyte-erythroid-megakaryocyte-macrophage were found during culture. This phenomenon was in part due to the fact that a significant reduction of apoptotic fractions was found in the CD34(+) cells, which were cultured on the adherent monolayer for up to 5 weeks. To gather quantitative data on the number of endothelial cells derived from a given number of CD34 cells, we performed limiting dilution assay by using Poisson distribution: the number of tested cells (linear scale) producing a 37% negative culture (logarithmic scale) is the number of cells containing one endothelial cell. By this method, one endothelial cell may be found from 314 CD34(+) cells after 5 weeks of culture. These results suggest that the UCB CD34(+) cell fraction contains endothelial cell precursors, establishing the hematopoietic microenvironment and providing the beneficial effects through downregulating apoptosis on UCB expansion protocols. These observations may provide insight for future cellular therapy or graft engineering.