Spectroscopy - Volume 21, issue 2

Authors: Gierlinger, Notburga | Schwanninger, Manfred

Article Type: Research Article

Abstract: To gain a better understanding on structure, chemical composition and properties of plant cells, tissues and organs several microscopic, chemical and physical methods have been applied during the last years. However, a knowledge gap exists about the location, quantity and structural arrangement of molecules in the native sample or what happens on the molecular level when samples are chemically or mechanically treated or how they respond to mechanical stress. These questions need to be answered to optimise utilization of plants in food industry and pharmacy and to understand structure-function relationships of plant cells to learn from natures unique. Advances in …combining microscopy with Raman spectroscopy have tackled this problem in a non-invasive way and provide chemical and structural information in situ without any staining or complicated sample preparation. In this review the different Raman techniques (e.g. near infrared Fourier Transform Raman spectroscopy (NIR-FT), resonance Raman spectroscopy, surface-enhanced Raman spectroscopy) are briefly described before approaches in plant science are summarised. Investigations on structural cell wall components, valuable plant substances, metabolites and inorganic substances are included with emphasis on Raman imaging. The introduction of the NIR-FT-Raman technique led to many applications on green plant material by eliminating the problem of sample fluorescence. For mapping and imaging of whole plant organs (seeds, fruits, leaves) the lateral resolution (~10 μm) of the NIR-FT technique is adequate, whereas for investigations on the lower hierarchical level of cells and cell walls the high resolution gained with a visible laser based system is needed. Examples on high resolution Raman imaging are given on wood cells, showing that changes in chemistry and orientation can be followed within and between different cell wall layers having dimensions smaller than 1 μm. In addition imaging the distribution of amorphous silica is shown on horsetail tissue, including an area scan from a cross section as well as a depth profiling within a silica rich knob of the outer stem wall. Show more

Keywords: Cellulose, cell walls, chemotaxonomy, crystallinity, hemicelluloses, inorganic substances, lignin, micromechanical studies, minerals, molecular stress, plant fibres, plant metabolites, silica, terpenes

Citation: Spectroscopy, vol. 21, no. 2, pp. 69-89, 2007

Authors: Xiao, Helan | Cai, Guoping | Liu, Mingyao

Article Type: Research Article

Abstract: Extracellular matrix (ECM) plays an important role in cell differentiation, growth, migration and apoptosis. Collagen is the most abundant protein family in vivo, but its function has still not been clearly defined yet. Reactive oxygen species (ROS) have a central role in oxidative cell stress. Electron spin resonance (ESR) spectroscopy indicates that type I collagen could uniquely scavenge hydroxyl radicals in dose- and time-dependent manner; whereas BSA and gelatin (a denatured collagen) have no such an effect. However, the mechanism by which type I collagen scavenges hydroxyl radicals is different from that of GSH, a well-known free radical scavenger. Using …a new method, two-dimensional FTIR correlation analysis, for the first time, we show that the order of functional group changes of type I collagen in this process is amide I earlier than amide II than amide III than –CH– than ν(C=O). The results indicates that the structure of the main chain of collagen changed first, followed by more residue group ν(C=O) exposed to hydroxyl radicals. The reaction with the carbonyl group in collagen causes the hydroxyl free radicals to be scavenged. Therefore, ECM can effectively scavenge ROS under normal physiological conditions. When the proteins of ECM were denatured in the same way as gelatin, they lost their function as a free radical scavenger. All of these results provide new insight into therapy or prevention of oxidative stress, apoptosis and ageing. Show more

Keywords: Free radicals, hydroxyl radicals, Fourier Transform Infrared Spectroscopy (FTIR), Two-Dimensional Fourier-Transform Infrared Correlation Spectroscopy (2D FTIR), type I collagen

Citation: Spectroscopy, vol. 21, no. 2, pp. 91-103, 2007

Authors: Mindukshev, Igor V. | Krivoshlyk, Vladimir V. | Ermolaeva, Elena E. | Dobrylko, Irina A. | Senchenkov, Evgeniy V. | Goncharov, Nikolay V. | Jenkins, Richard O. | Krivchenko, Alexander I.

Article Type: Research Article

Abstract: A low-angle light scattering technique, which has been applied previously to studies of blood platelets and Ehrlich ascite tumor cells, revealed differences in the dynamics of necrotic and apoptotic red blood cell death. Under hypotonic loading or in ammonia medium, red blood cells (RBC) swelled to a critical size (diameter approximately 13 μm) prior to hemolysis (necrosis). Under acidic loading, hemolysis occurred with less pronounced swelling of cells (diameter approximately 10 μm). Apoptosis induced by a calcium ionophore resulted in initial formation of echinocytes, followed by development of rounded red blood cells with uneven membrane, capable of agglomeration. In such …a way, RBC aggregation can precede the final stages of the RBC apoptosis when small cellular fragments are generated. On the basis of erythrograms of the cells hemolysing in ammonia medium, the echinocytic (preapoptotic) and stomatocytic (prenecrotic) RBC were discerned due to the very high resistance of apoptotic RBC to osmotic (ammonia) loading. Show more

Keywords: Hemolysis, erythrogram, necrosis, apoptosis, swelling, shrinkage

Citation: Spectroscopy, vol. 21, no. 2, pp. 105-120, 2007

Authors: Zinchenko, Valeriy P. | Goncharov, Nikolay V. | Teplova, Vera V. | Kasymov, Vitaliy A. | Petrova, Olga I. | Berezhnov, Alexey V. | Senchenkov, Evgeniy V. | Mindukshev, Igor V. | Jenkins, Richard O. | Radilov, Andrey S.

Article Type: Research Article

Abstract: Experiments were performed with rat liver mitochondria, Ehrlich ascite tumor cells (EATC) and cardiomyocytes, exposed to fluoroacetate (FA) or fluorocitrate (FC) in vitro. The effects of FA developed at much higher concentrations in comparison with FC and was dependent upon respiratory substrates: with pyruvate, FA induced a slow oxidation of pyridine nucleotides (NAD(P)H) and inhibition of respiration. NAD(P)H oxidation was prevented by incubation of mitochondria with cyclosporin A (CsA), an inhibitor of mitochondrial permeability transition pore. Studies of the NAD(P)H level and calcium response generated in EATC under activation with ATP via the metabotropic P2Y receptor, revealed a loss of …NAD(P)H from mitochondria resulting in a shift in the balance of mitochondrial and cytosolic NAD(P)H on exposure to FA. An increase of cytosolic [Ca2+ ] was observed in the cell lines exposed to FA and is explained by activation of plasma membrane calcium channels; this mechanism could have an impact on amplitude and rate of Ca2+ waves in cardiomyocytes, and cause the hypersensitivity of platelets reported on earlier. Highlighting the reciprocal relationship between intracellular NAD(P)H and calcium balance, we discuss metabolic pathway modulation in the context of development of an effective therapy for FA poisoning. Show more

Keywords: Fluoroacetate, intracellular calcium, pyridine nucleotides, mitochondria, membrane potential

Citation: Spectroscopy, vol. 21, no. 2, pp. 121-134, 2007

Authors: Gao, Xiaofei | Liu, Houyong | Song, Zhenghua | He, Xili | Dong, Faxin

Article Type: Research Article

Abstract: A novel chemiluminescence method for the assay of sudan I was designed using flow injection with chemiluminescence detection. The proposed method was based on the increment effect of sudan I on the chemiluminescence intensity in the luminol–KIO4 system. The increment of chemiluminescence intensity was correlated with the sudan I concentration in the range from 0.1 to 10 pg ml−1 , and the determination could be performed in 0.5 min in flow rate of 2 ml min−1 , including sampling and washing, giving a throughput of 120 h−1 with a relative standard deviation of less than 5.0%. The method …had been successfully applied to the assay of sudan I in Pixian douban, Golden mark guilin chilli sauce and Golden mark satay sauce, and the recovery was 90.0–103.8%. Show more

Keywords: Sudan I, chemiluminescence, luminol, flow injection

Citation: Spectroscopy, vol. 21, no. 2, pp. 135-141, 2007