A Rare Case of Terminal Ileum Gastrointestinal Stromal Tumor in a Young Caucasian Adult.

Gastrointestinal stromal tumors (GISTs) are rare in young individuals and typically affect older adults. We present the case of a previously healthy male who presented with severe hematochezia, fatigue, and dizziness. Colonoscopy did not demonstrate any colonic mass. CT of the pelvis with contrast revealed a pelvic mass measuring 7.4 cm. Biopsy confirmed a low-grade mixed-type GIST of the terminal ileum. Surgical resection was successfully performed. Histopathological analysis further characterized the tumor, and the patient was discharged with consideration of adjuvant imatinib therapy. This case underscores the importance of thorough diagnostic evaluation and multidisciplinary management for atypical presentations of gastrointestinal bleeding in young patients.

Chemokine Assay Matrix Defines the Potency of Human Bone Marrow Mesenchymal Stromal Cells.

Potency analysis of mesenchymal stromal cells (MSCs) is required for their use in advanced clinical trials. Assay matrix strategy evaluating more than a single property of MSCs is an emerging strategy in potency analysis. Here we developed an assay matrix approach focusing on the secretory chemokine responses of MSCs using multiplex analytical method. MSCs' innate fitness in secreting matrix of chemokines is correlated with their metabolic fitness in differential degrees. In addition, innately secreting chemokines are correlated among themselves in a unique pattern. MSC's matrix chemokine responses to exogenous stimulation of IFNγ and/or TNFα are distinct. However, the combination of IFNγ and TNFα is superior than individual stimulations in eliciting robust and broad matrix chemokine responses of MSCs. Correlation matrix analysis has identified that chemokine responses to IFNγ and/or TNFα display unique correlative secretion patterns. MSC and peripheral blood mononuclear cells coculture analysis has identified the correlation matrix responses of chemokines that predicted immune suppression. In addition, MSC-mediated blocking of T-cell proliferation predominantly correlates with chemokines in an inverse manner. Knockdown of chemokines has demonstrated that MSC-sourced inherent chemokines do not actively play a role in T-cell suppression and thus are the bystander predictors of T-cell suppression. The present analysis of MSC's matrix chemokine responses can be deployed in the advanced potency analysis of MSCs.