Comprehension of pretense in children with autism

In an attempt to tap underlying competencies, the ability of children with autism to comprehend pretend acts carried out by an experimenter was compared with that shown by controls. These acts consisted of the pouring of a pretend substance from an appropriate container onto a target figure. There was no significant difference in the groups' ability to identify the pretend substance involved, to predict the pretend outcome of the actions, or to reflect on the pretend nature of the episodes. However, the performance of controls on these latter two tasks was surprisingly poor, limiting the implications that might be drawn from the observed absence of group differences in comprehension abilities.We are very grateful to the teachers and headteachers of the following schools for their cooperation and assistance throughout the period of this research: John Worrall School, Sheffield; Doucecroft School, Kelvedon; East Hill First and Middle School, Sheffield; East Hill Second School, Sheffield; Mossbrook School, Sheffield; Priory School, Doncaster; The Rowan School, Dore; St. Mary's School, Sheffield. We also thank James Russell for his helpful comments of earlier drafts of this paper.     

Risk factors for neck pain in office workers: a prospective study

Background  

Persisting neck pain is common in society. It has been reported that the prevalence of neck pain in office workers is much higher than in the general population. The costs to the worker, employer and society associated with work-related neck pain are known to be considerable and are escalating. The factors that place office workers at greater risk of developing neck pain are not understood. The aim of this study is to investigate the incidence and risk factors of work-related neck pain in Australian office workers.     

In vivo MRI of cancer cell fate at the single-cell level in a mouse model of breast cancer metastasis to the brain.

Metastasis (the spread of cancer from a primary tumor to secondary organs) is responsible for most cancer deaths. The ability to follow the fate of a population of tumor cells over time in an experimental animal would provide a powerful new way to monitor the metastatic process. Here we describe a magnetic resonance imaging (MRI) technique that permits the tracking of breast cancer cells in a mouse model of brain metastasis at the single-cell level. Cancer cells that were injected into the left ventricle of the mouse heart and then delivered to the brain were detectable on MR images. This allowed the visualization of the initial delivery and distribution of cells, as well as the growth of tumors from a subset of these cells within the whole intact brain volume. The ability to follow the metastatic process from the single-cell stage through metastatic growth, and to quantify and monitor the presence of solitary undivided cells will facilitate progress in understanding the mechanisms of brain metastasis and tumor dormancy, and the development of therapeutics to treat this disease.     

Mediastinal lymphoblastic lymphoma with an immature B-cell immunophenotype.

A 19-year-old woman presented with a large mediastinal mass, histologically shown to be malignant lymphoma of lymphoblastic type (LBL). Immunophenotypic and gene rearrangement analysis unequivocally demonstrated that the neoplasm was of B-cell lineage. The neoplastic cells expressed terminal deoxynucleotidyl transferase, the pan-B cell antigens CD19, CD20, and CD22, and were negative for immunoglobulins and numerous T-cell antigens tested. Southern blot analysis showed rearrangement of one allele of the immunoglobulin heavy chain gene while the immunoglobulin kappa and T-cell receptor beta chain genes were in the germline configuration. Thus, the immunophenotypic and molecular findings in this case correspond to an early stage of B-cell differentiation, the pre-pre B-cell stage as has been named by others. In contrast with LBL of immature T-cell lineage, precursor B-cell LBLs involving the mediastinum are truly rare. Occasional cases have been reported that have arisen elsewhere and subsequently involved the mediastinum at time of relapse or tumor progression. Well-documented examples of immature B-cell LBL arising in the mediastinum are virtually unreported. The site and cell population giving rise to this neoplasm is unknown. However, origin from precursors of normal thymic medullary B cells is proposed as one possibility.     

Primary stimulation of CD4+ cells in the presence of IL-4 or IFN-gamma alters the frequencies of cytokine-producing cells at restimulation.

The induction of specific effector functions in naive T cells may be directed by accessory signals during activation. These could be elicited through binding to cell surface molecules or through factors secreted by antigen-presenting cells or other simultaneously activated cells. We have investigated the influence of CD8+ cells and of exogenously added cytokines (interleukin (IL)-2, IL-4 and interferon (IFN)-gamma) on the cytokine production in splenic CD4+ T cells. IL-2, IL-4, IL-5 and IFN-gamma production in CD4+ cells was measured at the single cell level during primary mitogen stimulation in vitro in the presence or absence of factors or CD8+ cells. On day 5 the cells were restimulated with mitogen alone and analysed to evaluate the short-term development of cytokine-producing cells in such cultures. Preactivation in the presence of either exogenous IL-4 or IFN-gamma led to an increased production of IL-4 and IFN-gamma respectively at restimulation, and the effects of both IL-4 and IFN-gamma were augmented by IL-2. After preactivation in the presence of IL-2 and IL-4, every third CD4+ cell could be induced to produce IL-4. Exogenous IL-4 or IFN-gamma further decreased each other's production. Depletion of CD8+ cells before activation resulted in a slight increase of IL-4-producing cells, indicating that simultaneous activation of CD8+ cells will influence lymphokine production in CD4+ cells. The results suggest that the pattern of lymphokines induced in naive cells may be influenced by factors secreted by preactivated CD4+ and CD8+ cells, and that naive cells are preferentially 'recruited' to produce similar cytokines.     

Preliminary assessment of the Dex Frame for assisting children with specific learning difficulties

A device called the Dex Frame has recently been marketed as an aid for children with specific learning difficulties. Using a test of reading speed and a test of reading accuracy we have attempted to evaluate the device. Two groups of children with learning difficulties were used, one having sole use of the device and being allowed to carry it with them and a second group who only used the device when attending for remedial tuition and assessment. The results show that no significant improvement occurred in reading performance of the groups with learning difficulties using the Dex Frame as compared with a control group. The teachers of the groups did, however, feel that on an individual basis some children (< 10%) expressed that they felt more comfortable using the device.