28 research outputs found

    Characterization of metabolites in infiltrating gliomas using ex vivo &supl;H high-resolution magic angle spinning spectroscopy.

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    Gliomas are routinely graded according to histopathological criteria established by the World Health Organization. Although this classification can be used to understand some of the variance in the clinical outcome of patients, there is still substantial heterogeneity within and between lesions of the same grade. This study evaluated image-guided tissue samples acquired from a large cohort of patients presenting with either new or recurrent gliomas of grades II-IV using ex vivo proton high-resolution magic angle spinning spectroscopy. The quantification of metabolite levels revealed several discrete profiles associated with primary glioma subtypes, as well as secondary subtypes that had undergone transformation to a higher grade at the time of recurrence. Statistical modeling further demonstrated that these metabolomic profiles could be differentially classified with respect to pathological grading and inter-grade conversions. Importantly, the myo-inositol to total choline index allowed for a separation of recurrent low-grade gliomas on different pathological trajectories, the heightened ratio of phosphocholine to glycerophosphocholine uniformly characterized several forms of glioblastoma multiforme, and the onco-metabolite D-2-hydroxyglutarate was shown to help distinguish secondary from primary grade IV glioma, as well as grade II and III from grade IV glioma. These data provide evidence that metabolite levels are of interest in the assessment of both intra-grade and intra-lesional malignancy. Such information could be used to enhance the diagnostic specificity of in vivo spectroscopy and to aid in the selection of the most appropriate therapy for individual patients

    Two-year follow-up of the pharmacokinetics of immunosuppressive drugs in a neonate who underwent heart transplantation

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    Abstract: The pharmacokinetic properties of immunosuppressive drugs are quite different in newborns than in adults and few studies describe the pharmacokinetics of these drugs in pediatric heart transplant recipients. We report on the two-year follow up of a neonate who underwent heart transplantation for Hypoplastic Left Heart Syndrome on day of life 9. Two different immunosuppressive regimens were used: cyclosporine, azathioprine and prednisone in the early postoperative period, followed by the routine tacrolimus and mycophenolate mofetil combination plus prednisone from post-transplant day 22. Our findings demonstrate marked variability in immunosuppressive pharmacokinetic profiles early post-transplant. Frequent monitoring of drug levels is required to ensure that they remain within the therapeutic range. After the first 2-3 months post-transplant, changes in immunosuppressive drug levels are less marked and correlate more with the administered dosage

    Tpa-Induced Differentiation of Human Rhabdomiosarcoma Cells: Expression of the Myogenic Regulatory Factors.

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    RD cells (a cell line derived from a human rhabdomyosarcoma) undergo a very limited myogenic differentiation despite the fact that they express several myogenic determination genes. Since we have previously shown (Aguanno et ai., Cancer Res. 50, 3377, 1990) that the tumor promoter 12-0-tetradecanoylphorbol13-acetate (TPA) induces myogenic differentiation in these cells, in this paper we investigate the mechanism by which TPA interferes with the expression and/or function of the myogenic determination genes. Northern blot analysis revealed that RD cells express the myf3 (the human analog of MyoD) and myf4 (the human analog of myogenin) transcripts, but not myf5 or myf6 transcripts. The myf3 and the myf4 gene products are correctly translated and accumulated in the nuclei as shown by immunofluorescence analysis. The tumor promoter (TPA) does not modify the pattern of expression of the myf factors while it induces the accumulation of muscle-specific transcripts, such as ïĄ-actin and fast myosin light chain I, and their corresponding proteins. On the other hand, within 1 day of treatment, TPA inhibits the expression of the Id gene, which is a negative regulator of MyoD activity. However, while the TPA-induced inhibition of Id message accumulation correlates with differentiation, cell confluence also causes a reduction in Id message accumulation, without inducing differentiation. Under our experimental conditions, overexpression of any of the myf cDNAs in RD cells does induce spontaneous differentiation but enhances the effect of TPA treatment independently from the level of the expressed message. These data suggest that differentiation of RD cells is likely to depend upon the activity of complexes containing the various members of the MyoD family, which can be regulated by proteins affecting MyoD dimerization such as Id, but also by other mechanisms induced by TPA, such as phosphorylation
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