Delayed Lesions on Diffusion-Weighted Imaging in Initially Lesion-Negative Stroke Patients.

BACKGROUND AND PURPOSE: Lesions on diffusion-weighted imaging (DWI) occasionally appear on follow-up magnetic resonance imaging (MRI) among initially DWI-negative but clinically suspicious stroke patients. We established the prevalence of positive conversion in DWI-negative stroke and determined the clinical factors associated with it. METHODS: This retrospective, observational, single-center study included 5,271 patients hospitalized due to stroke/transient ischemic attack (TIA) in a single university hospital during 2010 to 2017. Patients without initial DWI lesions underwent follow-up DWI imaging as a routine practice. Adjusted hazard ratios (aHRs) for recurrent stroke risk according to positive conversion were determined using Cox proportional hazard regression. Adjusted odds ratios (aORs) and 95% confidence intervals (CIs) for positive conversion among initially DWI-negative patients were estimated. RESULTS: In total, 694 (13.2%) patients (mean±standard deviation age, 62.9±13.7 years; male, 404 [58.2%]) were initially DWI-negative. Among them, 22.5% had positive-conversion on follow-up DWI. Positive conversion was associated with a higher risk of recurrent stroke (aHR, 3.12; 95% CI, 1.56 to 6.26). Early neurologic deterioration (aOR, 15.1; 95% CI, 5.71 to 47.66), atrial fibrillation (aOR, 6.17; 95% CI, 3.23 to 12.01), smoking (aOR, 3.76; 95% CI, 2.19 to 6.63), pre-stroke dependency (aOR, 1.62; 95% CI, 1.15 to 2.27), objective hemiparesis (aOR, 4.39; 95% CI, 1.90 to 10.32), longer symptom duration (aOR, 2.17; 95% CI, 1.57 to 3.08), high cholesterol (aOR, 4.70; 95% CI, 1.78 to 12.77), National Institutes of Health Stroke Scale score (aOR, 1.44; 95% CI, 1.08 to 1.91), and high systolic blood pressure (aOR, 1.01; 95% CI, 1.00 to 1.02) were associated with a higher incidence of lesions with delayed appearance. Regarding the location of lesions on follow-up DWI, 34.6% and 21.2% were in the cortex and brainstem, respectively. CONCLUSIONS: In DWI-negative stroke/TIA, positive conversion is associated with a higher risk of recurrent stroke. DWI-negative stroke with factors related to positive conversion may require follow-up MRI for a definitive diagnosis.

Tcea3 regulates the vascular differentiation potential of mouse embryonic stem cells.

Tcea3 is present in high concentrations in mouse embryonic stem cells (mESCs) and functions to activate Lefly1, a negative regulator of Nodal signaling. The Nodal pathway has numerous biological activities, including mesoderm induction and patterning in early embryogenesis. Here, we demonstrate that the suppression of Tcea3 in mESCs shifts the cells from pluripotency into enhanced mesoderm development. Vascular endothelial growth factor A (VEGFA) and VEGFC, major transcription factors that regulate vasculogenesis, are activated in Tcea3 knocked down (Tcea3 KD) mESCs. Moreover, differentiating Tcea3 KD mESCs have perturbed gene expression profiles with suppressed ectoderm and activated mesoderm lineage markers. Most early differentiating Tcea3 KD cells expressed Brachyury-T, a mesoderm marker, whereas control cells did not express the gene. Finally, development of chimeric embryos that included Tcea3 KD mESCs was perturbed.

Comparison of immunomodulatory properties of mesenchymal stem cells derived from adult human tissues.

Mesenchymal stem cells (MSCs), which evoke only minimal immune reactivity, may have anti-inflammatory and immunomodulatory effects. In this study, we conducted a comparative analysis of the immunomodulatory properties of MSCs derived from adult human tissues including bone marrow (BM), adipose tissues (AT), umbilical cord blood (CB), and cord Wharton's jelly (WJ). Using a multiple cytokine detection assay, we showed that there were no significant differences in levels of secreted factors from non-stimulated MSCs. We compared the immunosuppressive effect of BM-MSCs, AT-MSCs, CB-MSCs, and WJ-MSCs on phytohemagglutinin-induced T-cell proliferation. AT-MSCs, CB-MSCs, and WJ-MSCs effectively suppressed mitogen-induced T-cell proliferation as effectively as did BM-MSCs. Levels of interferon (IFN)-gamma and tumor necrosis factor (TNF)-alpha secreted from activated T-cells increased over time, but these levels were significantly reduced when cocultured with each type of MSCs. In addition, the expression of hepatocyte growth factor, IL-10, transforming growth factor-beta(1), cyclooxygenase (COX)-1, and COX-2 were unchanged in MSCs treated with IFN-gamma and/or TNF-alpha, while indoleamine 2,3-dioxygenase (IDO) expression increased. IFN-gamma and/or TNF-alpha produced by activated T-cells were correlated with induction of IDO expression by MSCs, which, in turn, suppressed T-cell proliferation. These findings suggest that MSCs derived from AT, CB, or WJ could be substituted for BM-MSCs for treatment of allogeneic conflicts.

Clinical value of new staging systems for multiple myeloma.

PURPOSE: We wanted to investigate the validity of the recently introduced Southwest Oncology Group (SWOG) staging system and the International Staging System (ISS) by comparing both systems with the widely accepted Durie/Salmon (DS) system for multiple myeloma patients. MATERIALS AND METHODS: Between 1992 and 2005, 85 multiple myeloma patients (men: women 41:44, median age: 63 years (range: 36~87)) with available baseline values of albumin and beta(2)-microglobulin were enrolled. The clinical and laboratory data were retrospectively obtained. RESULTS: According to the ISS, 11 patients were stage I (12.9%), 30 patients stage II (35.3%) and 44 patients stage III (51.8%). The median survivals of the ISS stages I, II and III were 78.6 months, 31.8 months and 15.1 months, respectively (p=0.015). The DS staging system was not able to predict the survival. For the SWOG staging system, 14 patients were stage I (16.4%), 27 patients stage II (31.8%), 27 patients stage III (31.8%) and 17 patients were stage IV (20.0%). The median survivals of the SWOG staging system stage I, II, III and IV were 78.6 months, 31.8 months, 11.6 months and 24.8 months, respectively (p=0.0075). CONCLUSION: The ISS staging system showed better reliability, simplicity and predictability for survival than the DS and SWOG staging systems for multiple myeloma patients.