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Latest Paper:
Top Curr Chem. 2012 ;316 :79-124
21769718
Faculty of Chemistry, University of Warsaw, Pasteura 1, 02093, Warsaw, Poland.
Fourier transform can be effectively used for processing of sparsely sampled multidimensional data sets. It provides the possibility to acquire NMR spectra of ultra-high dimensionality and/or resolution which allow easy resonance assignment and precise determination of spectral parameters, e.g., coupling constants. In this chapter, the development and applications of non-uniform Fourier transform is presented.
Institute for Neuroanatomy, Faculty of Medicine, RWTH Aachen University, Aachen, Germany.
Brain region specificity is a feature characteristic of neurodegenerative disorders, such as Huntington's disease (HD). We have studied the brain region-specific vulnerability of striatal compared with cortical and mesencephalic astrocytes treated with 3-nitropropionic acid (NPA), an in vitro model of HD. Mitochondrial dysfunction is involved in neurodegenerative processes. We have previously demonstrated a causal relationship between NPA-induced transcription of the cytochrome c oxidase (COX) subunit IV isoform (cox4i2) and increased oxidative stress leading to higher rates of necrotic cell death in striatal astrocytes by the application of a small interfering RNA knockdown system. Here, we have investigated the correlation of COX IV-2 protein expression with intracellular ATP content, mitochondrial peroxide production, and viability of astrocytes from three different brain regions. In cortical and mesencephalic astrocytes, NPA caused an elevation of cox4i2 transcription as in striatal astroglia. However, increased COX IV-2 and decreased COX IV-1 protein expression levels have been observed only in striatal astrocytes. In agreement with our hypothesis, Striatal astrocytes showed the highest levels of peroxide production and necrotic cell death rates compared with cortical and mesencephalic astroglia. Thus, we suggest that the higher vulnerability of astrocytes from the striatum in our in vitro model of HD is, at least in part, based on brain region-specific differences of the COX IV-2/COX IV-1 protein ratios and accompanied elevated oxidative stress.
Institute for Neuroanatomy, Faculty of Medicine, RWTH Aachen University, Wendlingweg 2, D-52074 Aachen, Germany.
Mitochondria play a pivotal role in the regulation of energy metabolism and apoptotic pathways. Properties and functions of mitochondria might render subsets of selectively vulnerable neurons intrinsically susceptible to a different extent to cellular stress and degeneration. We have investigated the effect of 3-nitropropionic acid (NPA), a mitochondrial toxin and mimicking symptoms of Huntington's disease (HD) when applied systemically, on mitochondrial function and viability of primary neurons isolated from mouse brain striatum and cortex. We observed a higher vulnerability of striatal compared with cortical neurons in response to NPA treatment. This effect might be correlated with the transcription pattern of cytochrome c oxidase (EC 1.9.3.1.; COX) subunit IV isoforms. In cortical neurons, NPA induced a down-regulation of the COX IV-2/COX IV-1 ratio, whereas an up-regulation was found in striatal neurons. Previously, we have shown that an increased COX IV-2/COX IV-1 ratio is responsible for a higher enzyme activity which is paralleled by elevated intracellular ATP levels at the expense of increased mitochondrial peroxide production. These effects could also be demonstrated in striatal neurons. On the contrary, a decreased COX IV-2/COX IV-1 ratio was observed in cortical neurons which was accompanied by a decrease in intracellular ATP content and no significant changes in mitochondrial peroxide production. We propose that COX isoform IV-2 mediates increased oxidative stress that is, at least in part, responsible for a higher vulnerability of striatal compared with cortical neurons against NPA. This mechanism, in turn, may serve as an explanation for brain region-specific differences in the neuronal susceptibility to toxic conditions.
Institute for Neuroanatomy, Faculty of Medicine, RWTH Aachen University, Wendlingweg 2, 52074 Aachen, Germany.
Many neurodegenerative diseases, such as Morbus Parkinson, exhibit a gender-dependency showing a higher incidence in men than women. Most of the neurodegenerative disorders involve either causally or consequently a dysfunction of mitochondria. Therefore, neuronal mitochondria may demonstrate a gender-specificity with respect to structural and functional characteristics of these organelles during toxic and degenerative processes. The application of 6-OHDA (6-hydroxydopamine) in vitro and in vivo represents a well-accepted experimental model of Parkinson's disease causing Parkinsonian symptoms. Besides the known effects of 6-OHDA on mitochondria and neuronal survivability, we aimed to demonstrate that the mitochondrial neurotoxin affects the morphology and survival of primary dopaminergic and non-dopaminergic neurons in the mesencephalon in a gender-specific manner by influencing the transcription of mitochondrial genes, ATP and reactive oxygen species production. Our data suggest that cell death in response to 6-OHDA is primarily caused due to increased oxidative stress which is more pronounced in male than in female mesencephalic neurons.
J Neuroendocrinol. 2009 Jul 21;:
19686448
Cit:1
Institute of Neuroanatomy, Faculty of Medicine, RWTH Aachen University, Wendlingweg 2, D-52074 Aachen, Germany.
Abstract Estrogens are powerful endogenous and exogenous neuroprotective hormones in animal models of brain injury including focal cerebral ischemia. This protective effect has been proven under a variety of different treatments and injury paradigms such as in vivo and in vitro stroke conditions. Neuroprotection in the CNS by progesterone is less defined. In the present study, cultured cortical and midbrain mouse neurons and human neuroblastoma cells (SH-SY5Y) were exposed to combined glucose-serum deprivation (CGSD), which is regarded as a reliable model mimicking the effects of ischemia in vitro. Cell viability was assayed using LDH release and metabolic activity. Conditions for CGSD treatment were chosen to yield half-maximal cell death rates. Validity of CGSD in vitro was compared with permanent middle cerebral artery occlusion (MCAO) in vivo. CGSD for 4h induced half-maximal neuronal cell death. MCAO in vivo for the same period resulted in significant neuronal loss also suggesting the validity of CGSD as a suitable stroke-like in vitro model. Combined steroid treatment (17ss-estradiol and progesterone) but not the application of single steroids abolished CGSD-induced cell death of cortical neurons in vitro. In contrast, no cell protection was found in midbrain neurons or neuroblastoma cells. The co-application of estrogen (ICI 182,780) or progesterone (RU-486) receptor antagonists did not obviously counteract protective steroid effects. This suggests operation of non-classical steroid mechanisms and their implication in mediation of hormonal effects. The surplus of combined protective hormonal effects might be due to observed influence of progesterone application on neuronal estradiol synthesis. Our data clearly highlight the potential of a combined steroid treatment under toxic degenerative brain pathologies.
Magn Reson Chem. 2009 Jul 1;:
19572259
Chemistry Department, University of Warsaw, Pasteura 1, 02-093 Warsaw, Poland.
The complete assignment of (1)H and (13)C chemical shifts of natural abundance prenol-10 is reported for the first time. It was achieved using 3D NMR experiments, which were based on random sampling of the evolution time space followed by multidimensional Fourier transform. This approach makes it possible to acquire 3D NMR spectra in a reasonable time and preserves high resolution in indirectly detected dimensions. It is shown that the interpretation of 3D COSY-HMBC and 3D TOCSY-HSQC spectra is crucial in the structural analysis of prenol-10. Copyright (c) 2009 John Wiley & Sons, Ltd.
Glia. 2009 Mar 20;:
19306371
Cit:8
Institute for Neuroanatomy, Faculty of Medicine, RWTH Aachen University, Aachen, Germany.
Astrocyte mitochondria play an important role for energy supply and neuronal survival in the brain. Toxic and degenerative processes are largely associated with mitochondrial dysfunction. We, therefore, investigated the effect of 3-nitropropionic acid (NPA), a mitochondrial toxin and in vitro model of Huntington's disease (HD), on mitochondrial function and viability of primary striatal astrocytes. Although NPA is known as an irreversible inhibitor of succinate dehydrogenase, we observed an increase of astrocyte ATP levels after NPA treatment. This effect could be explained by NPA-mediated alterations of cytochrome c oxidase subunit IV isoform (COX IV) expression. The up-regulation of COX isoform IV-2 caused an increased enzyme activity at the expense of elevated mitochondrial peroxide production causing increased cell death. The application of a small interfering RNA against COX IV-2 revealed the causal implication of COX isoform IV-2 in NPA-mediated elevation of oxidative stress and necrotic cell death. Thus, we propose a novel, additional mechanism of NPA-induced cell stress and death which is based on structural and functional changes of astrocyte COX and which could indirectly impair neuronal survival.(c) 2009 Wiley-Liss, Inc.
Magn Reson Chem. 2008 Nov 7;:
18991321
Cit:1
Chemistry Department, University of Warsaw, Pasteura 1, 02-093 Warsaw, Poland.
An application of 3D version of HSQC-TOCSY experiment for the measurement of heteronuclear coupling constants of organic compounds yielding complex spectra is proposed. The approach presented here is based on the optimized random sampling of the evolution time space followed by Multidimensional Fourier Transform (MFT).In this study, we show that the interpretation of omega(3)-(13)C coupled (1)H-(13)C 3D HSQC-TOCSY spectra with E.COSY-type multiplets allows one to evaluate heteronuclear coupling constants of strychnine with high accuracy, whereas the employment of 2D methods is associated with signal overlap and use of conventionally recorded 3D NMR spectra cannot provide accurate results in an overnight experiment. Copyright (c) 2008 John Wiley & Sons, Ltd.
The quality of pain relief during the first 24 hours following day case surgery has been poorly documented. This study was conducted to evaluate the quality of postoperative pain relief when using dexibuprofen or paracetamol. 127 patients in the age group 17-78 who underwent day case surgery were asked to complete questionnaire 24 hours after the end of the operation. The majority of patients (74,02%) had pain after operation. 66,14% had only mild pain (VAS 1-5), 7,87% had difficulty in sleeping at night due to severe pain (VAS 6-8). In 88,89% of outpatients the use of dexibuprofen or paracetamol was effective with pain relief.
M Misiak,
H M Asatrian,
K Bieri,
M Czakon,
A Czarnecki,
T Ewerth,
A Ferroglia,
P Gambino,
M Gorbahn,
C Greub,
U Haisch,
A Hovhannisyan,
T Hurth,
A Mitov,
V Poghosyan,
M Slusarczyk,
M Steinhauser
Institute of Theoretical Physics, Warsaw University, PL-00-681 Warsaw, Poland and Theoretical Physics Division, CERN, CH-1211 Geneva 23, Switzerland.
Combining our results for various O(alpha_{s};{2}) corrections to the weak radiative B-meson decay, we are able to present the first estimate of the branching ratio at the next-to-next-to-leading order in QCD. We find B(B[over ]-->X_{s}gamma)=(3.15+/-0.23)x10;{-4} for E_{gamma}>1.6 GeV in the B[over ]-meson rest frame. The four types of uncertainties: nonperturbative (5%), parametric (3%), higher-order (3%), and m_{c}-interpolation ambiguity (3%) have been added in quadrature to obtain the total error.
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