No abstract

Early clinical cardiotoxicity in children treated with anthracycline is rare. A high maximal dose, or cumulative dose of anthracycline, female sex, black race, presence of trisomy 21, and treatment with amsacrine increase the risk for anthracycline-associated cardiotoxicity.

A panel of 24 healthy seropositive donors have been followed prospectively over a period of 15 months and monitored (1) for the level of EB virus shedding in the throat by means of a sensitive cord-blood transformation assay; (2) for the level of virus-infected B cells in the blood via a new in vitro protocol where "spontaneous transformation" can be seen to titrate against input cell number; (3) for anti-EB viral antibody titres and (4) for the prevailing level of virus-specific memory T cells in the circulation. Six donors shed easily detectable levels of EB virus into throat washings on every occasion of testing, whilst 16 other donors shed lower levels of virus detectable in throat washings on a majority (10 donors) or on a minority (6 donors) of test occasions; only 2/24 donors gave no evidence of virus shedding at any time. There was a direct relationship between the EB virus shedder status of an individual (i.e., the level of virus replication in the pharynx) and the number of infected B cells present in the circulation. These results indicate that chronic, usually low-grade, replication of the virus at some permissive site in the oro- and/or naso-pharynx is very often a stable accompaniment of the asymptomatic EB virus carrier state, and may indeed be essential for the long-term maintenance of that state.

Multiple-choice testing procedures that do not provide corrective feedback facilitate neither learning nor retention. In Studies 1 and 2, the performance of participants evaluated with the Immediate Feedback Assessment Technique (IF AT) , a testing method providing immediate feedback and enabling participants to answer until correct, was compared to that of participants responding to identical tests with Scantron answer sheets. Performance on initial tests did not differ, but when retested after delays of 1 day or 1 week, participants evaluated with the IF AT demonstrated higher scores and correctly answered more questions that had been initially answered incorrectly than did participants evaluated with Scantron forms. In Study 3, immediate feedback and answering until correct was available to all participants using either the IF AT or a computerized testing system on initial tests, with the final test completed by all participants using Scantron forms. Participants initially evaluated with the IF AT demonstrated increased retention and correctly responded to more items that had initially been answered incorrectly. Active involvement in the assessment process plays a crucial role in the acquisition of information, the incorporation of accurate information into cognitive processing mechanisms, and the retrieval of correct answers during retention tests. Results of Studies 1-3 converge to indicate that the IF AT method actively engages learners in the discovery process and that this engagement promotes retention and the correction of initially inaccurate response strategies.Testing and assessment are integral to the educational process. When university or college education takes place as tutorials or in classrooms with a small number of participants, essay examinations are preferred, as they are relatively easy to construct, they allow the instructor to assess the depth and breadth of participant understanding, and they

Lymphoblasts of two tissue culture strains (EB1 and EB2) from different biopsy specimens of Burkitt's lymphoma have been examined in thin sections by electron microscopy, and have each been found to carry a morphologically identical virus. The virus was observed in samples taken over many months, being present in about 1 to 2 per cent of the cells in two forms: Immature particles about 75 mµ in diameter which were seen in both the nucleus and cytoplasm; and larger mature particles with a diameter of 110 to 115 mµ, which were either within membrane-bounded cytoplasmic spaces or at the cell surface. There was some indication that the particles matured by budding through the cytoplasmic membranes. Both types of particle occurred in dead degenerating cells or, less frequently, in intact altered cells. The characteristic alterations of the latter included margination of the chromatin, fragmentation of the nuclear envelope, beaded opaque material in the mitochondria, and, with one of the cell strains (EB1), sheaves of altered spindle tubules. All attempts to isolate and identify the virus carried by the two strains of lymphoblasts failed. No pathological effects were caused in 8-day chick embryos inoculated either with whole lymphoblasts or extracts of disrupted lymphoblasts, using the intraallantoic, amniotic, and chorioallantoic routes, and the extraembryonic fluids of such chicks were without haemagglutinating activity for human, chicken, guinea pig, or monkey erythrocytes. Whole lymphoblasts or lymphoblast extracts were likewise without effect when inoculated intraperitoneally into newborn hamsters or two strains of newborn mice. Similar lymphoblast inocula did not cause detectable changes in 9 different test tissue culture systems even after 8 blind passages. The nature of the unknown, unidentified virus in the cultured lymphoblasts from Burkitt's lymphomas is considered and its possible relationship to the cells discussed.

Students prepared for classroom examinations by completing practice tests, with selected items from these practice tests repeated, in either the original or in a modified wording, on classroom examinations and a final examination. The availability of immediate self-corrective feedback on Study 1 practice tests (0, 3, or 6 practice tests) was varied , while in Study 2, the timing of feedback provided during practice tests (immediate, end of test, 24-hour delay, control) was varied . Performance on examinations was elevated by the provision of immediate feedback on practice tests in both studies, especially when test items were presented in their original wording, with some generalization observed on items presented in a modified wording. Predictions made in accordance with the interference-perseveration hypothesis and the delayretention effect were not supported. These results demonstrate considerable potential for immediate self-corrective feedback, delivered during test preparation through the Immediate Feedback Assessment Technique, to enhance performance on classroom examinations and to promote the retention of factual information during the academic semester.

No abstract

Schizophrenia is associated with deficits in cortical plasticity that affect sensory brain regions and lead to impaired cognitive performance. Here we examined underlying neural mechanisms of auditory plasticity deficits using combined behavioural and neurophysiological assessment, along with neuropharmacological manipulation targeted at the N-methyl-D-aspartate type glutamate receptor (NMDAR). Cortical plasticity was assessed in a cohort of 40 schizophrenia/schizoaffective patients relative to 42 healthy control subjects using a fixed reference tone auditory plasticity task. In a second cohort (n = 21 schizophrenia/schizoaffective patients, n = 13 healthy controls), event-related potential and event-related time-frequency measures of auditory dysfunction were assessed during administration of the NMDAR agonist d-serine. Mismatch negativity was used as a functional read-out of auditory-level function. Clinical trials registration numbers were NCT01474395/NCT02156908 Schizophrenia/schizoaffective patients showed significantly reduced auditory plasticity versus healthy controls (P = 0.001) that correlated with measures of cognitive, occupational and social dysfunction. In event-related potential/time-frequency analyses, patients showed highly significant reductions in sensory N1 that reflected underlying impairments in θ responses (P < 0.001), along with reduced θ and β-power modulation during retention and motor-preparation intervals. Repeated administration of d-serine led to intercorrelated improvements in (i) auditory plasticity (P < 0.001); (ii) θ-frequency response (P < 0.05); and (iii) mismatch negativity generation to trained versus untrained tones (P = 0.02). Schizophrenia/schizoaffective patients show highly significant deficits in auditory plasticity that contribute to cognitive, occupational and social dysfunction. d-serine studies suggest first that NMDAR dysfunction may contribute to underlying cortical plasticity deficits and, second, that repeated NMDAR agonist administration may enhance cortical plasticity in schizophrenia.