Regulation of memory CD4 T-cell pool size and function by natural killer T cells in vivo

To develop more effective vaccines and strategies to regulate chronic inflammatory diseases, it is important to understand the mechanisms of immunological memory. Factors regulating memory CD4⁺ T helper (Th)-cell pool size and function remain unclear, however. We show that activation of type I invariant natural killer T (iNKT) cells with glycolipid ligands and activation of type II natural killer T (NKT) cells with the endogenous ligand sulfatide induced dramatic proliferation and expansion of memory, but not naïve, CD4 T cells. NKT cell-induced proliferation of memory Th1 and Th2 cells was dependent largely on the production of IL-2, with Th2-cell proliferation also affected by loss of IL-4. Type II NKT cells were also required for efficient maintenance of memory CD4 T cells in vivo. Activation of iNKT cells resulted in up-regulation of IFN-γ expression by memory Th2 cells. These IFN-γ–producing memory Th2 cells showed a decreased capability to induce Th2 cytokines and eosinophilic airway inflammation. Thus, activated NKT cells directly regulate memory CD4 T-cell pool size and function via the production of cytokines in vivo.     

Usefulness of prominently projected aortic arch on chest radiograph to predict severe tortuosity of the right subclavian or brachiocephalic artery in patients aged >44 years undergoing coronary angiography with a right radial artery approach

Although it is well known that certain characteristics, such as older age, female gender, hypertension, and high body mass index, are closely associated with severe arterial tortuosity among patients undergoing transradial coronary angiography, few data are available regarding useful predictors of severe arterial tortuosity among geriatric patients. The purpose of the present study was to evaluate the characteristics of geriatric patients with severe tortuosity of the right subclavian artery or brachiocephalic artery. The coronary angiographic reports of patients with severe tortuosity of the right subclavian artery or brachiocephalic artery and age- and gender-matched control patients were retrospectively evaluated. A total of 847 consecutive patients underwent right transradial coronary angiography. Of these patients, 48 (5.7%) had severe tortuosity (29 women, age 73.4 ± 8.6 years). The factors associated with severe arterial tortuosity were greater body mass index (odds ratio 1.17, p = 0.02), the presence of a prominently projected aortic arch on a chest radiograph (odds ratio 5.62, p <0.01), and lower serum creatinine value (odds ratio 0.05, p <0.01). In conclusion, the presence of a prominently projected aortic arch on the chest radiograph is a useful predictor of severe arterial tortuosity.     

Retrospective analysis of treatment outcomes in 70 patients with t(8;21) acute myeloid leukemia

We conducted a retrospective study to evaluate outcomes and prognostic factors of newly diagnosed patients with t(8;21) acute myeloid leukemia (AML). There were 70 patients (43 men and 27 women) with a median age of 48 years old (range, 17～76 years old). Sixty-five patients achieved complete remission (CR) after induction chemotherapy. Fifty-seven patients received consolidation chemotherapy based on the policy of not performing allogeneic hematopoietic stem cell transplantation (allo-HSCT) at the time of first CR. Twenty-seven of the 57 patients relapsed (relapse rate, 47%). The median time from the achievement of the first CR to relapse was 307 days (96～1,256 days). A white blood cell count of more than 25,400/μl at diagnosis was associated with a higher relapse rate than a white blood cell count of less than or equal to 25,400/μl (75% vs. 43%, P=0.04). Nineteen of the 25 relapsed patients who received re-induction therapy experienced a second CR (second CR rate, 76%). Twenty-six patients (5 with first CR, 12 with second CR, and 9 without remission) received allo-HSCT. The five-year overall survival and disease-free survival rates were 61% and 45%, respectively. Patients with t(8;21) AML had a high CR rate, but about half of them relapsed. However, this report could not show prognostic factors for the identification of patients who should receive allo-HSCT at the time of their first CR.