Recurrent Colonic Perforation in Geriatric Patients with Sigmoid Colostomy: Two Case Reports / 이화의대지

Recurrent colonic perforation in patients already having colostomy is extremely rare and only a few cases had been reported. Herein, we report 2 cases of recurrent colonic perforation at the proximal part of the colostomy in geriatric patients resulting from different causes, which might be caused by stercoral perforation and recurrent colonic ischemia, respectively. Based on our experience, surgeons should consider correcting chronic constipation even in patients who already have a colostomy.Additionally, transverse colostomy should be considered as a surgical treatment in patients with sigmoid colostomy for recurrent perforation due to colonic ischemia.

Minute Colon Perforation by a Nonabsorbable Suture Knot after Uterine Myomectomy / 이화의대지

We report a rare case of suture material-related colon perforation. A 60-year-old woman visited clinics because of the nonspecific abdominal discomfort for several months. There were no specific medical history except previous laparoscopic myomectomy 15 years ago. Colonoscopy and abdomen-pelvis computed tomography revealed an unknown foreign body penetrating the sigmoid colon wall adjacent to the uterus. We performed laparoscopic exploration with foreign body removal and primary colon wall repair. The foreign body was identified as a non-absorbable suture material suggestive of used in previous myomectomy. With recent trends for minimally invasive procedures in the field of pelvic organ surgery, surgeons, especially those without sufficient training have to pay attention to selecting the proper surgical suture materials. (Ewha Med J 2022;45(3):e7)

Generation of an osteoblast-based artificial niche that supports in vitro B lymphopoiesis

B lymphocytes are produced from hematopoietic stem cells (HSCs) through the highly ordered process of B lymphopoiesis, which is regulated by a complex network of cytokines, chemokines and cell adhesion molecules derived from the hematopoietic niche. Primary osteoblasts function as an osteoblastic niche (OBN) that supports in vitro B lymphopoiesis. However, there are significant limitations to the use of primary osteoblasts, including their relative scarcity and the consistency and efficiency of the limited purification and proliferation of these cells. Thus, development of a stable osteoblast cell line that can function as a biomimetic or artificial OBN is necessary. In this study, we developed a stable osteoblastic cell line, designated OBN4, which functions as an osteoblast-based artificial niche that supports in vitro B lymphopoiesis. We demonstrated that the production of a B220⁺ cell population from Lineage⁻ (Lin⁻) Sca-1⁺ c-Kit⁺ hematopoietic stem and progenitor cells (HSPCs) was increased ~1.7-fold by OBN4 cells relative to production by primary osteoblasts and OP9 cells in coculture experiments. Consistently, OBN4 cells exhibited the highest production of B220⁺ IgM⁺ cell populations (6.7±0.6–13.6±0.6%) in an IL-7- and stromal cell-derived factor 1-dependent manner, with higher production than primary osteoblasts (3.7±0.5–6.4±0.6%) and OP9 cells (1.8±0.6–3.9±0.5%). In addition, the production of B220⁺ IgM⁺ IgD⁺ cell populations was significantly enhanced by OBN4 cells (15.4±1.1–18.9±3.2%) relative to production by primary osteoblasts (9.5±0.6–14.6±1.6%) and OP9 cells (9.1±0.5–10.3±1.8%). We conclude that OBN4 cells support in vitro B lymphopoiesis of Lin⁻ Sca-1⁺ c-Kit⁺ HSPCs more efficiently than primary osteoblasts or OP9 stromal cells.