| 1. |
- Greve, Tanja M., et al.
(författare)
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FTIR imaging and ATR-FT-Far-IR synchrotron spectroscopy of pig ear skin
- 2010
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Ingår i: Spectroscopy: An International Journal. - 0712-4813. ; 24:1-2, s. 105-111
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Konferensbidrag (refereegranskat)abstract
- FTIR imaging was performed on pig ear skin samples cryo-sectioned perpendicular to the skin surface. The OH-stretch region revealed the distribution of water; the amide II band gave the protein distribution; the C=O stretch and C-H stretch regions showed the variation in lipids. Water and proteins were similarly distributed. Triglycerides were predominantly found in the deeper skin layers whereas free fatty acids and ceramides were more dominant in the upper layers. ATR-FT-Far-IR spectroscopy with synchrotron radiation was used on full thickness pig ear skin biopsies. The Far-IR spectra showed hands in the region from 100-150 cm(-1) due to hydrogen bonded proteins and a band around 180 cm(-1) arising from "free" water.
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| 2. |
- Krasteva, Maria, et al.
(författare)
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A dialysis accessory for attenuated total reflection infrared spectroscopy
- 2006
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Ingår i: Spectroscopy. - 0712-4813. ; 20:3, s. 89-94
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Tidskriftsartikel (refereegranskat)abstract
- A dialysis accessory for attenuated total reflection (ATR) infrared spectroscopy is described together with an evaluation based on known systems with well-studied infrared spectra, such as chemical oxidation and reduction of cytochrome c and substrate binding to the Ca2+-ATPase. Changes in the infrared spectra of the two proteins are successfully monitored with the dialysis accessory. The accessory was developed in our laboratory for the diamond 9-reflections SensIR ATR unit. It can be used to study absorbance changes of macromolecules which are induced by low molecular weight compounds, for example the binding of substrates, inhibitors or ions to macromolecules as well as effects of pH, ionic strength or denaturants on the structure of macromolecules. The dialysis accessory confines the macromolecule of interest to a sample compartment created between the ATR crystal and the dialysis membrane. On the other side of the dialysis membrane, a reservoir for the sample medium is created. In this way the low molecular weight compound of interest can exchange freely between the reservoir and the sample compartment via the dialysis membrane. This provides a flexible way to change sample conditions for the macromolecule of interest, allowing for example initiation of ligand binding.
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| 3. |
- Lindskog, M, et al.
(författare)
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Monitoring intracellular metabolites in neuroblastoma with 1H NMR spectroscopy: effects of growth factor withdrawal and modulation of lipid metabolism
- 2004
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Ingår i: SPECTROSCOPY-AN INTERNATIONAL JOURNAL. - : Hindawi Limited. - 0712-4813. ; 18:2, s. 123-132
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Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)abstract
- 1H NMR spectroscopy has previously been employed to detect and monitor changes in the lipid metabolism of neuroblastoma cells upon cytotoxic treatment. Here, we addressed the question whether altered growth conditions, by presence or absence of serum, would impact on the metabolites detectable with1H NMR spectroscopy. Chronic serum deprivation of SH‒SY5Y human neuroblastoma cells resulted in a decrease in the intracellular content of several metabolites, in particular total choline. This metabolic effect was paralleled by significant growth inhibition. In addition, we investigated the potential functional origin of intracellular1H NMR visible lipids in SH‒SY5Y cells. A drop in lipid methylene protons could be observed shortly after serum‒withdrawal. Contrary, removal of lipoproteins from the serum led to a pronounced increase in intracellular lipids, as did inhibition of de novo sterol synthesis by lovastatin. In conclusion, we demonstrate that intracellular total choline in neuroblastoma cells in vitro is highly dependent on the availability of growth factors. Furthermore, we show that1H NMR visible lipids decrease upon serum‒withdrawal but are accumulated when cholesterol supply is abrogated. The biological and potential clinical implications of these findings are discussed.
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| 4. |
- O'Maille, G, et al.
(författare)
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Metabolomics relative quantitation with mass spectrometry using chemical derivatization and isotope labeling
- 2008
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Ingår i: SPECTROSCOPY-AN INTERNATIONAL JOURNAL. - : Hindawi Limited. - 0712-4813. ; 22:5, s. 327-343
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Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)abstract
- Comprehensive detection and quantitation of metabolites from a biological source constitute the major challenges of current metabolomics research. Two chemical derivatization methodologies, butylation and amination, were applied to human serum for ionization enhancement of a broad spectrum of metabolite classes, including steroids and amino acids. LC-ESI-MS analysis of the derivatized serum samples provided a significant signal elevation across the total ion chromatogram to over a 100-fold increase in ionization efficiency. It was also demonstrated that derivatization combined with isotopically labeled reagents facilitated the relative quantitation of derivatized metabolites from individual as well as pooled samples.
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| 5. |
- Orädd, Greger, et al.
(författare)
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Pfg NMR studies of lateral diffusion in oriented lipid bilayers
- 2005
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Ingår i: SPECTROSCOPY-AN INTERNATIONAL JOURNAL. - 0712-4813. ; 19:4, s. 191-8
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Tidskriftsartikel (refereegranskat)abstract
- The pfg-NMR diffusion technique is proposed to have an appreciable potential for future biophysical investigations in the field of membrane biology. Topics like transport of molecules both across and in the plane of the membrane can be successfully studied, as well as the formation of lipid domains and their intrinsic dynamics can be scrutinized. This short review will introduce the fundamental aspects of orientation dependent NMR interactions and the technique of macroscopically oriented bilayers for eliminating the unwanted effects of those interactions. The pfg-NMR technique will be briefly introduced and finally, some recent results illustrating the potential of the method are presented.
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| 6. |
- Ramser, Kerstin, et al.
(författare)
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The combination of resonance Raman spectroscopy, optical tweezers and microfluidic systems applied to the study of various heme-containing single cells
- 2008
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Ingår i: Spectroscopy (Ottawa). - 0712-4813 .- 1875-922X. ; 22:4, s. 287-295
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Tidskriftsartikel (refereegranskat)abstract
- Several recent studies on the function of neuroglobin (Ngb), a hemoprotein predominantly expressed in the brain, point toward a neuro-protective role during hypoxic-ischemic injuries. The exact mechanism by which Ngb protects the cell against H2O2-induced cell death remains to be elucidated. Hence, new tools need to be developed in order to study the protein in vivo or under physiological conditions. In this summary of our work, we demonstrate how resonance Raman spectroscopy, optical tweezers and microfluidic systems were combined to mimic in vivo conditions in an in vitro milieu. The setup has been tested on several globin-containing cells: hemoglobin (Hb) within single red blood cells (RBCs), a nerve globin present in the nerve cord of the annelid Aphrodite aculeata (A. aculeata), and wild-type (wt) human neuroglobin (NGB) overexpressed in Escherichia coli (E. coli) bacteria. The feasibility of the setup regarding sensitivity and photo-induced effects and the results regarding the oxygen uptake and release will be discussed and compared for each system. The summary of the results show that the method is promising and the setup will be developed further to monitor the dependence of the neuronal action potential on nerve globins.
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| 7. |
- Szabo, BK, et al.
(författare)
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Dynamic MR imaging as a predictor of prognosis in breast cancer
- 2006
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Ingår i: SPECTROSCOPY-AN INTERNATIONAL JOURNAL. - : Hindawi Limited. - 0712-4813. ; 20:1, s. 19-28
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Forskningsöversikt (övrigt vetenskapligt/konstnärligt)abstract
- Contrast-enhanced MR imaging (CE-MRI) has become a widely accepted complementary method for diagnosing breast cancer. It has been suggested for evaluating patients with breast implants, patients at risk of tumour multifocality or recurrence, search for occult primary cancer in presence of axillary metastasis and monitoring the effect of preoperative chemotherapy. The clinical usefulness of MR imaging in patients with increased genetic risk of breast cancer is still under investigation. There is scientific evidence to support the hypothesis that CE-MRI may carry the prognostic significance of angiogenesis, and one of the future indications of this method can be the prognostic evaluation of breast cancer patients by the functional mapping of the angiogenic activity of tumours. On the basis of the promising results of recent reports, further large-scale studies are needed to evaluate the impact of MR parameters on long term overall survival of patients with breast cancer.
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| 8. |
- Voinova, Marina V., 1958, et al.
(författare)
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On dissipation of quartz crystal microbalance as a mechanical spectroscopy tool
- 2004
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Ingår i: Spectroscopy. - 0712-4813. ; 18:4, s. 537-544
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Tidskriftsartikel (refereegranskat)abstract
- We report on theoretical analysis of dissipative effects in quartz crystal resonator applications to the dynamics of complex biological fluids and soft polymer films. As a mechanical spectroscopy tool, the quartz resonator can probe the storage and loss moduli μ(ω) of a thin material sample in small amplitude oscillations where polymers exhibit linear viscoelasticity. We show how viscosity (internal friction) and slippage (interfacial friction) of the sample affect the acoustical characteristics of the quartz resonator. With respect to biosensor's application, we present rigorous expressions for the resonant frequency and damping of the quartz crystal which allow to quantify friction effects and even distinguish between them in resonator measurements performing on various frequencies. Possible application of the results in electronic nose and electronic tongue sensors is discussed.
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