Although positron emission tomography (PET) is an established diagnostic method in brain and lung cancer, its use is often confined to research. The authors report a case of a minimally symptomatic intramedullary spinal cord metastasis, an uncommon and often diagnostically challenging lesion, that was confirmed by PET. A 37-year-old man with a history of metastatic renal cell carcinoma treated with systemic agents, an autologous stem cell transplant, and local palliative radiotherapy with a 2-month history of vague right foot numbness and right leg dysesthesias was found to have an intramedullary lesion at the level of T12. Although the findings of magnetic resonance imaging suggested central necrosis, a PET scan revealed a metabolically active lesion and confirmed the diagnosis of intramedullary metastasis. PET can be used to detect and confirm intramedullary spinal cord metastatic carcinoma. PET imaging may have a vital role in clinical diagnosis by helping to distinguish diagnostically troublesome lesions based on metabolic activity.

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Environmental tobacco smoke (ETS) has been linked to deleterious health effects, particularly pulmonary and cardiac disease; yet, the general public considers ETS benign to brain function in adults. In contrast, epidemiological data have suggested that ETS impacts the brain and potentially modulates neurodegenerative disease. The present study begins to examine yet unknown biochemical effects of ETS on the adult mammalian brain. In the developed animal model, adult male rats were exposed to ETS 3 h a day for 3 weeks. Biochemical data showed altered glial fibrillary acid protein levels as a main treatment effect of ETS, suggestive of reactive astrogliosis. Yet, markers of oxidative and cell stress were unaffected by ETS exposure in the brain regions examined. Increased proteolytic degradation of αII-spectrin by caspase-3 and the dephosphorylation of serine 116 on PEA-15 indicated greater apoptotic cell death modulated by the extrinsic pathway in the brains of ETS-exposed animals. Further, β-synuclein was upregulated by ETS, a neuroprotective protein previously reported to exhibit anti-apoptotic and anti-fibrillogenic properties. These findings demonstrate that ETS exposure alters the neuroproteome of the adult rat brain, and suggest modulation of inflammatory and cell death processes.

Background: Environmental tobacco smoke (ETS) exposure is linked to developmental deficits and disorders with known cerebellar involvement. However, direct biological effects and underlying neurochemical mechanisms remain unclear.Objectives: We sought to identify and evaluate underlying neurochemical change in the rat cerebellum with ETS exposure during critical period development.Methods: We exposed rats to daily ETS (300, 100, and 0 µg/m3 total suspended particulate) from postnatal day 8 (PD8) to PD23 and then assayed the response at the behavioral, neuroproteomic, and cellular levels.Results: Postnatal ETS exposure induced heightened locomotor response in a novel environment on par initially with amphetamine stimulation. The cerebellar mitochondrial subproteome was significantly perturbed in the ETS-exposed rats. Findings revealed a dose-dependent up-regulation of aerobic processes through the modification and increased translocation of Hk1 to the mitochondrion with corresponding heightened ATP synthase expression. ETS exposure also induced a dose-dependent increase in total Dnm1l mitochondrial fission factor; although more active membrane-bound Dnm1l was found at the lower dose. Dnm1l activation was associated with greater mitochondrial staining, particularly in the molecular layer, which was independent of stress-induced Bcl-2 family dynamics. Further, electron microscopy associated Dnm1l-mediated mitochondrial fission with increased biogenesis, rather than fragmentation.Conclusions: The critical postnatal period of cerebellar development is vulnerable to the effects of ETS exposure, resulting in altered behavior. The biological effect of ETS is underlain in part by a Dnm1l-mediated mitochondrial energetic response at a time of normally tight control. These findings represent a novel mechanism by which environmental exposure can impact neurodevelopment and function.

In this study, various proteomics-based methods were utilized to examine the 14-3-3 protein family in Arabidopsis thaliana. A protein extract was prepared from an Arabidopsis hypocotyl suspension culture and analyzed by two-dimensional gel electrophoresis and immunoblotting with a 14-3-3 monoclonal antibody that recognizes multiple Arabidopsis isoforms. Protein spots that cross-reacted with the monoclonal antibody as well as the surrounding spots were analyzed by high performance liquid chromatography in conjunction with electrospray-tandem mass spectrometry. Nine separate spots contained 14-3-3s and each spot contained multiple 14-3-3 isoforms. Every isoform observed was verified by the identification of at least one isoform-specific peptide. Further analysis by mass spectrometry revealed that the isoforms Chi, Upsilon, Omega, Phi, and Lambda were acetylated on their N termini and no non-acetylated N termini were recovered. These data, together with the distribution of isoforms and the confirmation that 14-3-3s are not complexed during urea denaturing isoelectric focusing, supports the conclusion that Arabidopsis 14-3-3s are acetylated in vivo and are significantly affected by other post-translational modifications.

Ion exchange chromatography is a fractionation technique applicable to the separation of brain-derived proteins based on charge. Proteome complexity overwhelms analytical approaches, which is mitigated by fractioning samples into simpler solutions. In this chapter we will cover the design, optimization, and execution of an ion exchange experiment for the separation of a brain lysate. Furthermore, helpful tips and pitfall will be revealed to aid with potential problems that may arise. The discussed proteomic methodology is applicable to multidimensional separations ahead of bottom-up or top-down proteomic strategies for characterizing the neuroproteome.

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