G-CSF administration is neuroprotective following transient cerebral ischemia even in the absence of a functional NOS-2 gene

Granulocyte colony-stimulating factor (G-CSF) is a candidate neuroprotective factor following cerebral ischemia. To determine whether G-CSF acts partly through the inhibition of nitric oxide synthase (NOS)-2 expression, we administered G-CSF to male NOS-2−/− mice after cerebral ischemia. Although male NOS-2−/− mice exhibit resistance to the gross effects of cerebral ischemia, they display neuronal loss and skilled motor deficits following cerebral ischemia. Administration of G-CSF during reperfusion reduced motor deficit and neuronal loss. Thus, G-CSF is still effective in NOS-2 gene-deficient mice, suggesting that part of the mechanism of action is independent of NOS-2.     

An in vitro study into the corrosion of intra-oral magnets in the presence of dental amalgam

The aim of this investigation was to study the corrosion behaviour and products of uncoated neodymium-iron-boron magnets in the presence of dental amalgam. Microcosm plaques were grown on discs of neodymium-iron-boron magnets or amalgam in a constant depth film fermentor. The biofilms were supplied with artificial saliva and growth was determined by viable counting. The results showed that the neodymium-iron-boron magnets corroded with an average daily weight loss of 0.115 +/- 0.032 per cent. However, when the magnets were in close proximity to the amalgam the amount of corrosion was reduced to a daily loss of 0.066 +/- 0.023 per cent. The highest loss of constituent elements from the corrosion products of the magnets was observed for iron. The composition of the microcosm plaques altered markedly between the two materials with less streptococci and more Veillonella spp. present in the biofilms grown on magnets in the presence of amalgam. The corrosion of neodymium-iron-boron magnets is limited and in the presence of amalgam is reduced further. This suggests that amalgam present in the mouth will not cause an increased clinical risk in terms of biocompatibility with neodymium-iron-boron magnets.     

Giant congenital melanocytic nevi in a patient with brain structural malformations and multiple lipomatosis

We present a 9-year-old boy diagnosed from birth with giant congenital melanocytic nevi. He had central structural brain malformations of hemimegalencephaly of the right frontotemporal lobe and left occipitoparietal lobe, choroid plexus hypertrophy, and a Dandy-Walker variant. In addition, he developed multiple lipomatoses. These lesions were cutaneous except for two at the cerebellopontine angles, which were present from birth. This patient represents a rarely documented example of two histopathologies resulting in serious complications. The diagnostic issues and histopathologic process are discussed.     

Further characterisation of a thromboembolic model of stroke in the rat

We have used magnetic resonance imaging (MRI) techniques to characterise a rat model of thromboembolic stroke. The consequences of acute perfusion deficit associated with a middle cerebral artery occlusion (MCAo) by a newly formed thrombus was mapped by interrogation of the tissue oxygenation status using gradient echo methods and production of T2* maps. Final infarct size was subsequently assessed at 24-h post-ischaemia by histology with 2,3,5-triphenyltetrazolium chloride (TTC) staining. Animals displayed an infarct volume of 178.7+/-84.2 mm(3) (mean+/-S.D.) with a large coefficient of variation (47%) and range of values (85.6--265.5 mm(3)). This variability provided us with an opportunity to assess the relationships between early imaging observations and eventual infarct size. For a single cerebral slice, at the centre of the MCA territory, a relationship between the area of reduced T2* at 1 and 2 h post MCAo correlated highly with final lesion area (Spearman rank correlation, r=0.98, P<0.01, n=9). Lesion volumes in the thromboembolic MCAo model were compared with a 120-min occlusion, 22-h reperfusion protocol using an intraluminal thread MCAo approach. For the thromboembolic model, the total lesion volume was found to be smaller (178.7+/-84.2 vs. 243.3+/-50.1 mm(3), mean+/-S.D., Student's t-test P=0.046) and showed a greater variability (coefficient of variations: 47% vs. 21%). These data underline the relative variability of this embolic model and provide important preliminary information regarding the value of early changes in T2* in predicting eventual infarct size.     

Obesity in leukemia survivors: the familial contribution

A high prevalence of obesity in survivors of acute lymphoblastic leukemia (ALL) has been described, but genetic and social influence in obesity has not been analyzed in this group of patients. The authors studied a population of 33 long-term (25 females, 8 males) in first remission who had reached their final height. All patients received cranial irradiation as part of their central nervous system (CNS)-directed therapy and no patient received growth hormone. The body mass index (BMI: weight/height²) of patients and their biological parents was calculated and submitted to statistical analysis. Obesity was defined as BMI greater than the 85th centile. No excessive obesity was found among the males at final height. Fifty-six percent of the females were obese. In this group of 14 obese female survivors 59% had obese mother, but only 14% had obese fathers. The results indicate a significant maternal predisposition to obesity.     

T-cell lymphomas mask slower developing B-lymphoid and myeloid tumours in transgenic mice with broad haemopoietic expression of MYC

Deregulation of MYC expression occurs in many haematological malignancies. Previous studies modelling MYC-induced lymphomagenesis in the mouse used transgenic vectors that directed MYC overexpression in a lineage-specific manner. Here, we describe a transgenic mouse strain in which constitutive MYC expression is driven broadly in haemopoiesis by a vector containing regulatory elements of the Vav gene. Healthy young VavP-MYC17 mice had multiple haemopoietic abnormalities, most notably increased size and numbers of B-lymphoid cells, monocytes and megakaryocytes. The mice rapidly developed tumours and, surprisingly, these were exclusively T-cell lymphomas, mostly of mature CD4(+) CD8(-) T cells, a tumour type that is seldom seen in mouse models. To examine tumour development in the absence of the susceptible T cells, we bred VavP-MYC17 mice lacking the Rag1 recombinase. They survived longer and succumbed to tumours of several different haemopoietic cell types: pre-T cells, pro-B cells, macrophages and unusual progenitor cells. Thus, although T-lineage cells have the shortest latent period to transformation, the VavP-MYC17 transgene drives malignant transformation of multiple cell types and VavP-MYC17 mice provide a new model for tumours of multiple haemopoietic lineages.     

A narrative review shows the unvalidated use of self-report questionnaires for individual medication as outcome measures

OBJECTIVE: Accurate individualized data on drug consumption is required for a number of purposes. While electronic medication event monitoring is the best objective measure available, self-report tools would be a useful alternative in certain situations. We searched for validated self-completion questionnaires suitable for measuring change in medication. METHODS: A systematic search of the English language literature since 1980, and a narrative literature review. RESULTS: Few articles described the development or use of self-report methods to measure change in medication over time. We found no questionnaire that was commonly used for this purpose, nor one that had been evaluated and published. Considerable work has been undertaken to develop questionnaires or diaries for individual projects, but because these tools and their validation are rarely published, they are not available for other researchers to use, and comparison across studies is difficult. Some work has been done developing diary formats and the Medication Quantification Scale converts complex medication change data to a single numerical score. CONCLUSION: Medication change is rarely considered as an outcome, and when it is measured, nonstandardized methods are used. More attention needs to be given to developing self-report tools and validating them across a range of criteria.