It is important to select an appropriate surrogate matrix for preparing calibration standards and quality control samples while quantitatively assaying for endogenous substances, because a blank matrix that does not contain the endogenous substance cannot be derived from the species from which the target study samples are collected. This is because the assay results might be affected, depending on the characteristics of the analyte in the surrogate matrix. Our discussion group that participated in the Japan Bioanalysis Forum discussed the recommended selection strategies, focusing on large and small molecules in ligand binding assays and LC–MS, respectively. We established an efficient selection strategy for a surrogate matrix, with simple compositions as the first candidates stated in this article.
Background
Dasatinib is a second-generation tyrosine kinase inhibitor that is indicated for the treatment of patients with chronic myeloid leukemia. Here, we report the case of a man with nephrotic syndrome that was caused by dasatinib.
Case presentation
A 40-year-old man with chronic myeloid leukemia was referred to our hospital because of proteinuria 1 month after dasatinib therapy was introduced. A percutaneous kidney biopsy was performed, diffuse glomerular endothelial injury and effacement of the foot process were noted, and the patient was diagnosed with dasatinib-induced nephrotic syndrome. Additionally, in an electron microscopy study, randomly arranged fibrils were observed in the mesangial and subendothelial regions. Switching from dasatinib to nilotinib led to a decrease in the proteinuria level, from 12 to 0.6 g/g creatinine, within 2 weeks. The patient was discharged from our department on the 25th day after hospitalization, without any drug aftereffects.
Conclusions
Drug-related nephrotic syndrome should be considered when nephrotic syndrome develops during treatment with dasatinib.
Liposarcoma of the uterine corpus is extremely rare. We performed a laparotomy on a 55-year-old woman with the complaints of abdominal distension and genital bleeding who was found to have a uterine tumor, 17 × 16 cm in diameter. The preoperative diagnosis was a lipoma or lipoleiomyoma of the uterine corpus. However, pathological examination revealed proliferation of mature adipocytes and lipoblast-like atypical cells with small, weakly pleomorphic nuclei and foamy or vacuolated cytoplasm present within a fibrous septum. Immunohistochemistry showed that the tumor cells were focally positive for mouse double minute 2 homolog (MDM2). The final pathological diagnosis was a well-differentiated liposarcoma of International Federation of Gynecology and Obstetrics (FIGO) stage IB (pT1bNxM0). On magnetic resonance imaging (MRI), T1 -weighted and fat-saturated images showed high and low intensity in the tumor, respectively, suggesting that this tumor contained a fat component. The septum inside the tumor had a contrast enhancement on T1-weighted, gadolinium-enhanced imaging. The septum was nonuniformly thickened and partially nodular. In hindsight, these findings may have suggested a well-differentiated liposarcoma in the uterine corpus rather than a lipoma or lipoleiomyoma. Clinicians should be aware of the possibility of a liposarcoma of the uterine corpus when a neoplasm contains adipose tissue and a nonuniformly thickened or partially nodular septum on MRI.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.