In this task, you are given a passage which has a question and the context. You have to generate an answer to the question based on the information present in the context.

Q: Context: Allogeneic mesenchymal stem cells (MSCs) exhibit therapeutic effects in human autoimmune diseases such as systemic lupus erythematosus (SLE), but the underlying mechanisms remain largely unknown. The aim of this study was to investigate how allogeneic MSCs mediate immunosuppression in lupus patients.', 'The effects of allogeneic umbilical cord-derived MSCs (UC-MSCs) on inhibition of T cell proliferation were determined. MSC functional molecules were stimulated with peripheral blood mononuclear cells from healthy controls and SLE patients and examined by real-time polymerase chain reaction. CD4+ and CD8+ T cells were purified using microbeads to stimulate MSCs in order to determine cytokine expression by MSCs and to further determine which cell subset(s) or which molecule(s) is involved in inhibition of MSC-mediated T cell proliferation. The related signaling pathways were assessed. We determined levels of serum cytokines in lupus patients before and after UC-MSC transplantation.', 'Allogeneic UC-MSCs suppressed T cell proliferation in lupus patients by secreting large amounts of indoleamine 2,3-dioxygenase (IDO). We further found that interferon-γ (IFNγ), which is produced predominantly by lupus CD8+ T cells, is the key factor that enhances IDO activity in allogeneic MSCs and that it is associated with IFNGR1/JAK-2/STAT signaling pathways. Intriguingly, bone marrow-derived MSCs from patients with active lupus demonstrated defective IDO production in response to IFNγ and allogeneic CD8+ T cell stimulation. After allogeneic UC-MSC transplantation, serum IDO activity increased in lupus patients.\Question: Is a CD8 T cell/indoleamine 2,3-dioxygenase axis required for mesenchymal stem cell suppression of human systemic lupus erythematosus?

A: We found a previously unrecognized CD8+ T cell/IFNγ/IDO axis that mediates the therapeutic effects of allogeneic MSCs in lupus patients.
****
Q: Context: To study E2F3a expression and its clinical significance in children with acute lymphoblastic leukemia (ALL).', 'We quantified E2F3a expression at diagnosis in 148 children with ALL by real-time PCR. In the test cohort (n = 48), receiver operating characteristic (ROC) curve was used to find the best cut-off point to divide the patients into E2F3a low- and high-expression groups. The prognostic significance of E2F3a expression was investigated in the test cohort and confirmed in the validation cohort (n = 100). The correlations of E2F3a expression with the clinical features and treatment outcome of these patients were analyzed.', 'ROC curve analysis indicated that the best cut-off point of E2F3a expression was 0.3780. In the test cohort, leukemia-free survival (LFS) and event-free survival (EFS) of the low-expression group were lower than those of the high-expression group (log rank: P = 0.026 for both). This finding was verified in the validation cohort. LFS, EFS, and overall survival were also lower in the low-expression group than in the high-expression group (log rank, P = 0.015, 0.008, and 0.002 respectively). E2F3a low expression was correlated with the existence of BCR-ABL fusion. An algorithm composed of E2F3a expression and minimal residual disease (MRD) could predict relapse or induction failure more precisely than current risk stratification. These results were still significant in the ALL patients without BCR-ABL fusion.\Question: Does e2F3a gene expression have prognostic significance in childhood acute lymphoblastic leukemia?

A: Low expression of E2F3a was associated with inferior prognosis in childhood ALL. An algorithm composed of E2F3a expression and MRD could predict relapse or induction failure more precisely than that of the current risk stratification.
****
Q: Context: This study examined the relationship between plasma cholesterol and circulating triiodothyronine and oestradiol in 561 adolescent girls aged 11-17 with eating disorders.', 'Plasma total cholesterol, high-density lipoprotein cholesterol, serum triodothyronine and oestradiol were measured at assessment, and historical weight data were obtained from growth charts provided by the school health services. Cholesterol levels were related to weight change, menstrual status and serum hormones.', 'Plasma total cholesterol levels of >5.0 mmol/L were found in 38% of the 77 girls who were premenarcheal, 32% of the 199 with secondary amenorrhoea and 17% of those who were still menstruating. These cholesterol levels were inversely related to serum oestradiol and triiodothyronine concentrations, but not weight change, in amenorrhoic girls and were positively related to body mass index and inversely related to weight loss and serum triiodothyronine in girls who were still menstruating.\Question: Is plasma cholesterol related to menstrual status in adolescent girls with eating disorders and weight loss?

A:
Increased plasma total cholesterol was related to amenorrhoea in adolescent girls with eating disorders and weight loss. Oestrogens appeared to mediate the effect of starvation on cholesterol, most effectively in premenarcheal girls. Re-establishing menstruation is an important goal in the treatment of eating disorders, to avoid dyslipidaemia and the risk of future cardiovascular disease.
****