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.

Context: Some subjects with suspected asthma and a negative exercise challenge test (ECT) demonstrate improved expiratory flow rates after administration of bronchodilators (BD) at the end of the ECT (unpublished observation). This study investigated whether this response predicts the presence of bronchial hyperreactivity (BHR).', 'The study population included 133 young adults (29.4% women) 21.1 +/- 4.2 years of age who underwent ECT and a methacholine challenge test (MCT). A receiver-operator-characteristic curve was used to calculate the optimal cutoff level of the response to BD as a predictor of BHR according to MCT.', 'Using a MCT cutoff level of PC(20) </= 4 mg/mL showed BHR in 12.8% of subjects. Failure to improve FEV(1) by 8% after BD administration predicted the absence of BHR with sensitivity, specificity, and positive and negative predictive values of 76.5%, 68.4%, 25.3%, and 95.5%, respectively. Avoiding MCT in subjects with less than 8% response to BD would have saved 62.5% of the MCTs and would have missed only four (3%) patients with BHR.\Question: Does response to bronchodilators after exercise challenge predict bronchial hyperreactivity?
BD should be administered routinely after ECT, as the response may be used as a simple, inexpensive tool to predict BHR in young patients and may substantially reduce the number of unnecessary MCTs.

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?
We found a previously unrecognized CD8+ T cell/IFNγ/IDO axis that mediates the therapeutic effects of allogeneic MSCs in lupus patients.

Context: The DSM-5 encompasses a wide range of symptoms for Major Depressive Disorder (MDD). Symptoms are commonly added up to sum-scores, and thresholds differentiate between healthy and depressed individuals. The underlying assumption is that all patients diagnosed with MDD have a similar condition, and that sum-scores accurately reflect the severity of this condition. To test this assumption, we examined the number of DSM-5 depression symptom patterns in the "Sequenced Treatment Alternatives to Relieve Depression" (STAR*D) study.', 'We investigated the number of unique symptom profiles reported by 3703 depressed outpatients at the beginning of the first treatment stage of STAR*D.', 'Overall, we identified 1030 unique symptom profiles. Of these profiles, 864 profiles (83.9%) were endorsed by five or fewer subjects, and 501 profiles (48.6%) were endorsed by only one individual. The most common symptom profile exhibited a frequency of only 1.8%. Controlling for overall depression severity did not reduce the amount of observed heterogeneity.\Question: Is depression a consistent syndrome : An investigation of unique symptom patterns in the STAR*D study?

Symptoms were dichotomized to construct symptom profiles. Many subjects enrolled in STAR*D reported medical conditions for which prescribed medications may have affected symptom presentation.