The Influence of Perceptual Training on Working Memory in Older Adults

Normal aging is associated with a degradation of perceptual abilities and a decline in higher-level cognitive functions, notably working memory. To remediate age-related deficits, cognitive training programs are increasingly being developed. However, it is not yet definitively established if, and by what mechanisms, training ameliorates effects of cognitive aging. Furthermore, a major factor impeding the success of training programs is a frequent failure of training to transfer benefits to untrained abilities. Here, we offer the first evidence of direct transfer-of-benefits from perceptual discrimination training to working memory performance in older adults. Moreover, using electroencephalography to evaluate participants before and after training, we reveal neural evidence of functional plasticity in older adult brains, such that training-induced modifications in early visual processing during stimulus encoding predict working memory accuracy improvements. These findings demonstrate the strength of the perceptual discrimination training approach by offering clear psychophysical evidence of transfer-of-benefit and a neural mechanism underlying cognitive improvement

Modulation of Aβ(42 )low-n oligomerization using a novel yeast reporter system

BACKGROUND: While traditional models of Alzheimer's disease focused on large fibrillar deposits of the Aβ(42 )amyloid peptide in the brain, recent work suggests that the major pathogenic effects may be attributed to SDS-stable oligomers of Aβ(42). These Aβ(42 )oligomers represent a rational target for therapeutic intervention, yet factors governing their assembly are poorly understood. RESULTS: We describe a new yeast model system focused on the initial stages of Aβ(42 )oligomerization. We show that the activity of a fusion of Aβ(42 )to a reporter protein is compromised in yeast by the formation of SDS-stable low-n oligomers. These oligomers are reminiscent of the low-n oligomers formed by the Aβ(42 )peptide in vitro, in mammalian cell culture, and in the human brain. Point mutations previously shown to inhibit Aβ(42 )aggregation in vitro, were made in the Aβ(42 )portion of the fusion protein. These mutations both inhibited oligomerization and restored activity to the fusion protein. Using this model system, we found that oligomerization of the fusion protein is stimulated by millimolar concentrations of the yeast prion curing agent guanidine. Surprisingly, deletion of the chaperone Hsp104 (a known target for guanidine) inhibited oligomerization of the fusion protein. Furthermore, we demonstrate that Hsp104 interacts with the Aβ(42)-fusion protein and appears to protect it from disaggregation and degradation. CONCLUSION: Previous models of Alzheimer's disease focused on unravelling compounds that inhibit fibrillization of Aβ(42), i.e. the last step of Aβ(42 )assembly. However, inhibition of fibrillization may lead to the accumulation of toxic oligomers of Aβ(42). The model described here can be used to search for and test proteinacious or chemical compounds for their ability to interfere with the initial steps of Aβ(42 )oligomerization. Our findings suggest that yeast contain guanidine-sensitive factor(s) that reduce the amount of low-n oligomers of Aβ(42). As many yeast proteins have human homologs, identification of these factors may help to uncover homologous proteins that affect Aβ(42 )oligomerization in mammals

Imaging findings in noncraniofacial childhood rhabdomyosarcoma

Rhabdomyosarcoma (RMS) is the most common soft-tissue sarcoma of childhood. This paper is focuses on imaging for diagnosis, staging, and follow-up of noncraniofacial RMS

Imaging findings in craniofacial childhood rhabdomyosarcoma

Rhabdomyosarcoma (RMS) is the commonest paediatric soft-tissue sarcoma constituting 3–5% of all malignancies in childhood. RMS has a predilection for the head and neck area and tumours in this location account for 40% of all childhood RMS cases. In this review we address the clinical and imaging presentations of craniofacial RMS, discuss the most appropriate imaging techniques, present characteristic imaging features and offer an overview of differential diagnostic considerations. Post-treatment changes will be briefly addressed

ISSN exercise & sport nutrition review: research & recommendations

Sports nutrition is a constantly evolving field with hundreds of research papers published annually. For this reason, keeping up to date with the literature is often difficult. This paper is a five year update of the sports nutrition review article published as the lead paper to launch the JISSN in 2004 and presents a well-referenced overview of the current state of the science related to how to optimize training and athletic performance through nutrition. More specifically, this paper provides an overview of: 1.) The definitional category of ergogenic aids and dietary supplements; 2.) How dietary supplements are legally regulated; 3.) How to evaluate the scientific merit of nutritional supplements; 4.) General nutritional strategies to optimize performance and enhance recovery; and, 5.) An overview of our current understanding of the ergogenic value of nutrition and dietary supplementation in regards to weight gain, weight loss, and performance enhancement. Our hope is that ISSN members and individuals interested in sports nutrition find this review useful in their daily practice and consultation with their clients

Trisomy of leukemic cell chromosomes 4 and 10 identifies children with B-progenitor cell acute lymphoblastic leukemia with a very low risk of treatment failure: a Pediatric Oncology Group study

Abstract To account for the superior prognosis of hyperdiploid, B-progenitor acute lymphoblastic leukemia (ALL), we investigated the influence of trisomy in 1021 children greater than or equal to 1 year old by recursive partitioning analysis. The patients were treated according to a stratified, randomized study testing antimetabolite-based therapies. Trisomies of several individual chromosomes were associated with a better prognosis in a univariate statistical analysis. Of greater importance, trisomy of both chromosomes 4 and 10 identified a subgroup of patients (n = 180) with an extremely favorable 4-year event-free survival (EFS). Combined trisomy of chromosomes 4 and 10 retained its prognostic significance after stratification of patients by DNA index, age, and leukocyte count. Among patients with a DNA index greater than 1.16, patients with trisomies of both chromosomes 4 and 10 had a 4-year EFS of 96.6% (n = 161, SE = 3.8%), whereas patients with neither or only one of these trisomies had a 4-year EFS of 70.4% (n = 73, SE = 11.5%). All 19 patients with a DNA index less than or equal to 1.16 but with trisomies of chromosomes 4 and 10 remain in remission, suggesting that favorable chromosome trisomy dominates in a situation in which the cellular DNA content of less than or equal to 1.16 predicts a less favorable outcome. We conclude that combined trisomy of chromosomes 4 and 10 independently predicts EFS among children with B-progenitor ALL. Patients within the B-progenitor group who have this feature (about 20% of those with clonal abnormalities) are likely to be cured with antimetabolite-based chemotherapy--an approach that should produce few significant late effects.</jats:p

Trisomy of leukemic cell chromosomes 4 and 10 identifies children with B-progenitor cell acute lymphoblastic leukemia with a very low risk of treatment failure: a Pediatric Oncology Group study

To account for the superior prognosis of hyperdiploid, B-progenitor acute lymphoblastic leukemia (ALL), we investigated the influence of trisomy in 1021 children greater than or equal to 1 year old by recursive partitioning analysis. The patients were treated according to a stratified, randomized study testing antimetabolite-based therapies. Trisomies of several individual chromosomes were associated with a better prognosis in a univariate statistical analysis. Of greater importance, trisomy of both chromosomes 4 and 10 identified a subgroup of patients (n = 180) with an extremely favorable 4-year event-free survival (EFS). Combined trisomy of chromosomes 4 and 10 retained its prognostic significance after stratification of patients by DNA index, age, and leukocyte count. Among patients with a DNA index greater than 1.16, patients with trisomies of both chromosomes 4 and 10 had a 4-year EFS of 96.6% (n = 161, SE = 3.8%), whereas patients with neither or only one of these trisomies had a 4-year EFS of 70.4% (n = 73, SE = 11.5%). All 19 patients with a DNA index less than or equal to 1.16 but with trisomies of chromosomes 4 and 10 remain in remission, suggesting that favorable chromosome trisomy dominates in a situation in which the cellular DNA content of less than or equal to 1.16 predicts a less favorable outcome. We conclude that combined trisomy of chromosomes 4 and 10 independently predicts EFS among children with B-progenitor ALL. Patients within the B-progenitor group who have this feature (about 20% of those with clonal abnormalities) are likely to be cured with antimetabolite-based chemotherapy--an approach that should produce few significant late effects.</jats:p

tdic(9;12): a nonrandom chromosome abnormality in childhood B-cell precursor acute lymphoblastic leukemia: a Pediatric Oncology Group Study

Abstract In a review of 432 children with newly diagnosed acute lymphoblastic leukemia (ALL), we identified a new nonrandom translocation, tdic(9;12)(p1?1;p1?2), in the leukemic marrow cells of eight patients. Seven had hypodiploid karyotypes that lacked chromosomes 9 and 12 and contained a der(12), tdic(9;12); the eighth had a pseudodiploid karyotype with two normal 9 chromosomes, one normal 12 and the der(12), tdic(9;12). Abnormalities involving chromosomes other than 9 and 12 were noted in four of the eight patients. All cells with the tdic(9;12) expressed both the common ALL antigen and HLA-DR. Cytoplasmic immunoglobulin, a marker of pre-B ALL, was detected in one case with the tdic(9;12) but was absent in the other seven. Our results suggest that the tdic(9;12)(p1?1;p1?2) rearrangement is specifically associated with leukemic B cell precursors.</jats:p

tdic(9;12): a nonrandom chromosome abnormality in childhood B-cell precursor acute lymphoblastic leukemia: a Pediatric Oncology Group Study

In a review of 432 children with newly diagnosed acute lymphoblastic leukemia (ALL), we identified a new nonrandom translocation, tdic(9;12)(p1?1;p1?2), in the leukemic marrow cells of eight patients. Seven had hypodiploid karyotypes that lacked chromosomes 9 and 12 and contained a der(12), tdic(9;12); the eighth had a pseudodiploid karyotype with two normal 9 chromosomes, one normal 12 and the der(12), tdic(9;12). Abnormalities involving chromosomes other than 9 and 12 were noted in four of the eight patients. All cells with the tdic(9;12) expressed both the common ALL antigen and HLA-DR. Cytoplasmic immunoglobulin, a marker of pre-B ALL, was detected in one case with the tdic(9;12) but was absent in the other seven. Our results suggest that the tdic(9;12)(p1?1;p1?2) rearrangement is specifically associated with leukemic B cell precursors.</jats:p