An intronic deletion in megakaryoblastic leukemia 1 is associated with hyperproliferation of B cells in triplets with Hodgkin lymphoma

Megakaryoblastic leukemia 1 (MKL1) is a coactivator of serum response factor and together regulate transcription of actin cytoskeleton genes. MKL1 is associated with hematologic malignancies and immunodeficiency, but its role in B cells is unexplored. Here we examined B cells from monozygotic triplets with an intronic deletion in MKL1, two of whom were previously treated for Hodgkin lymphoma. To investigate MKL1 and B cell responses in HL pathogenesis, we generated Epstein Barr virus-transformed lymphoblastoid cell lines from the triplets and two controls. While cells from the Hodgkin lymphoma treated patients had a phenotype close to healthy controls, cells from the undiagnosed triplet had increased MKL1 mRNA, increased MKL1 protein, and elevated expression of MKL1-dependent genes. This was associated with elevated actin content, increased cell spreading, decreased expression of CD11a integrin molecules, and delayed aggregation. Moreover, cells from the undiagnosed triplet proliferated faster, displayed a higher proportion of cells with hyperploidy, and formed large tumors in vivo. This phenotype was reversible by inhibiting MKL1 activity. Interestingly, cells from the triplet treated for Hodgkin lymphoma in 1985 contained two subpopulations: one with high expression of CD11a that behaved like control cells and the other with low expression of CD11a that formed large tumors in vivo similar to cells from the undiagnosed triplet. This implies that pre-malignant cells had re-emerged a long time after treatment. Together, these data suggest that dysregulated MKL1 activity participates in B cell transformation and Hodgkin lymphoma pathogenesis

HIV Risk Behavior Self-Report Reliability at Different Recall Periods

Few studies have investigated the optimal length of recall period for self-report of sex and drug-use behaviors. This meta-analysis of 28 studies examined the test-retest reliability of three commonly used recall periods: 1, 3, and 6 months. All three recall periods demonstrated acceptable test-retest reliability, with the exception of recall of needle sharing behaviors and 6-months recall of some sex behaviors. For most sex behaviors, a recall period of 3 months was found to produce the most reliable data; however, 6 months was best for recalling number of sex partners. Overall, shorter periods were found to be more reliable for recall of drug-use behaviors, though the most reliable length of recall period varied for different types of drugs. Implications of the findings and future directions for research are discussed

Failure of Working Memory Training to Enhance Cognition or Intelligence

Fluid intelligence is important for successful functioning in the modern world, but much evidence suggests that fluid intelligence is largely immutable after childhood. Recently, however, researchers have reported gains in fluid intelligence after multiple sessions of adaptive working memory training in adults. The current study attempted to replicate and expand those results by administering a broad assessment of cognitive abilities and personality traits to young adults who underwent 20 sessions of an adaptive dual n-back working memory training program and comparing their post-training performance on those tests to a matched set of young adults who underwent 20 sessions of an adaptive attentional tracking program. Pre- and post-training measurements of fluid intelligence, standardized intelligence tests, speed of processing, reading skills, and other tests of working memory were assessed. Both training groups exhibited substantial and specific improvements on the trained tasks that persisted for at least 6 months post-training, but no transfer of improvement was observed to any of the non-trained measurements when compared to a third untrained group serving as a passive control. These findings fail to support the idea that adaptive working memory training in healthy young adults enhances working memory capacity in non-trained tasks, fluid intelligence, or other measures of cognitive abilities.National Institutes of Health (U.S.) (Blueprint for Neuroscience Research (T90DA022759/R90DA023427)United States. Defense Advanced Research Projects Agency (government contract no. NBCHC070105)United States. Dept. of Defense (National Defense Science and Engineering Fellowship)Massachusetts Institute of Technology (Sheldon Razin (1959) Fellowship

Cytoskeletal control of B cell responses to antigens.

The actin cytoskeleton is essential for cell mechanics and has increasingly been implicated in the regulation of cell signalling. In B cells, the actin cytoskeleton is extensively coupled to B cell receptor (BCR) signalling pathways, and defects of the actin cytoskeleton can either promote or suppress B cell activation. Recent insights from studies using single-cell imaging and biophysical techniques suggest that actin orchestrates BCR signalling at the plasma membrane through effects on protein diffusion and that it regulates antigen discrimination through the biomechanics of immune synapses. These mechanical functions also have a role in the adaptation of B cell subsets to specialized tasks during antibody responses

Efficacy and Safety of Human Intravenous Immunoglobulin 10% (Panzyga®) in Patients with Primary Immunodeficiency Diseases: a Two-Stage, Multicenter, Prospective, Open-Label Study

PurposeTo assess the efficacy and safety of panzyga® (intravenous immunoglobulin 10%) in preventing serious bacterial infections (SBIs) in patients with primary immunodeficiency diseases (PIDs), a prospective, open-label, multicenter, phase 3 study and an open-label extension study were undertaken.MethodsInitially, the study drug (infusion rate ≤0.08 mL/kg/min) was administered at intervals of 3 or 4 weeks for 12 months, followed by 3 months of panzyga® at infusion rates increasing from 0.08 to 0.14 mL/kg/min. The primary endpoint in the main study was the rate of SBIs per patient-year on treatment. Secondary outcomes included non-serious infections, work/school absence, episodes of fever, quality of life, and adverse events (AEs).ResultsThe main study enrolled 51 patients (35% female, mean age 26.8 years), with 21 participating in the extension study. The rate of SBIs per patient-year was 0.08 in the total population; there were four SBIs in the 4-weekly treatment group (2/30 patients) and none in the 3-weekly group (n = 21). Compared with 4-weekly treatment, 3-weekly treatment was associated with a higher rate of upper respiratory tract infections (RTIs), ear infections, and work/school absences, but a lower rate of lower RTIs and fever. Treatment was generally well tolerated; no AE led to treatment withdrawal or death.ConclusionsOverall, the use of panzyga® in patients with antibody-deficient PID was associated with a low rate of AEs and was effective in preventing SBIs, exceeding US FDA and European Medicines Agency recommendations for efficacy