Biomedical Spectroscopy and Imaging - Volume 3, issue 1

Authors: Sharma, Uma | Jagannathan, Naranamangalam R.

Article Type: Research Article

Abstract: Diffusion weighted imaging (DWI) is a magnetic resonance imaging (MRI) technique that provides information on in vivo diffusion of water molecules in tissues which is referred as apparent diffusion coefficient (ADC). The advantage of DWI is the intrinsic tissue contrast it provides because of its sensitivity to the changes in cellular environment. Malignant breast tissues are characterized by low ADC while benign breast tissues and normal breast tissues of volunteers show high ADC values. Addition of DWI as an adjunct to the contrast-enhanced MRI of breast lesions has been shown to improve the specificity and the diagnostic accuracy. Despite significant …technical improvements in DWI, small lesions are sometimes difficult to visualize on ADC maps due to low spatial resolution and it is often difficult to differentiate non-mass like lesions using ADC values. Further, ADC values have the potential to delineate necrotic portions of the tumor from the viable tumor regions. Studies have shown that DWI has the potential to predict early response of tumors to therapeutic intervention in breast tumors. In recent years, numerous applications of DWI in breast tissue evaluation have been documented; however, there is a need for standardized methods for acquisition and processing of diffusion data for effective clinical applications. Show more

Keywords: Diffusion weighted imaging (DWI), apparent diffusion coefficient (ADC), breast cancer, diagnosis, therapy response

DOI: 10.3233/BSI-130061

Citation: Biomedical Spectroscopy and Imaging, vol. 3, no. 1, pp. 1-13, 2014

Authors: Anwar Alebrahim, M. | Krafft, C. | Sekhaneh, W. | Sigusch, B. | Popp, J.

Article Type: Research Article

Abstract: BACKGROUND: Valuable structural and chemical properties can be obtained for dentin and enamel by vibrational spectroscopy. A better understanding of structural and chemical changes in deciduous dentition will contribute to improved dental restoration procedures for adolescents. OBJECTIVE: ATR-FTIR and Raman spectroscopy were applied to study human permanent and primary teeth. Slices were prepared from 10 German, 10 Turkish and 25 Jordanian teeth. METHODS: Raman images were collected at 785 nm excitation. FTIR images were collected using a germanium ATR accessory and focal plane array detector. Average Raman and infrared spectra were calculated for analysis. RESULTS: Our results …showed that (i) the mineral to matrix ratio is lower in primary teeth than in permanent teeth, (ii) the carbonate to phosphate ratio was higher for primary teeth, (iii) crystallinity was lower in primary teeth, and (iv) collagen cross-links occurred to be higher in primary teeth. FTIR and Raman data confirmed the results of each other. Deconvolution of the infrared band near 870 cm−1 reveals evidence for A2-type carbonate substitution on hydroxyapatite of primary teeth spectra in addition to the A and B type carbonate substitution that are also found in permanent teeth. CONCLUSIONS: Beside chemical and structural differences found between primary and permanent teeth, variations between the origin and age of the specimens were observed which requires further systematic investigations. Show more

Keywords: Permanent teeth, primary teeth, deciduous dentition, ATR-FTIR spectroscopy, Raman spectroscopy

DOI: 10.3233/BSI-130059

Citation: Biomedical Spectroscopy and Imaging, vol. 3, no. 1, pp. 15-27, 2014

Authors: Bombalska, Aneta | Mularczyk-Oliwa, Monika | Jankiewicz, Bartłomiej | Bartosewicz, Bartosz | Gajda-Rączka, Magdalena | Kaliszewski, Miron | Włodarski, Maksymilian | Kwaśny, Mirosław | Kopczyński, Krzysztof | Szpakowska, Małgorzata | Trafny, Elżbieta A.

Article Type: Research Article

Abstract: In recent years, growing threat of terrorist attacks with use of chemical or biological warfare agents is observed. Biological agents, due to often delayed effects, higher lethality and more difficult detection and identification compared to chemical agents, are especially dangerous. Therefore, rapid detection and discrimination of dangerous biological materials has become a security aim of considerable importance. Various analytical methods, including FTIR spectroscopy combined with statistical analysis have been used to discriminate various bioagents and their background interferents. The applicability for this purpose of another spectroscopic technique, Surface Enhanced Raman Spectroscopy (SERS), has also been intensively investigated in recent years. …In this work, the results of the application of FTIR technique performed in reflectance mode using Horizontal Attenuated Total Reflectance accessory (HATR) for discrimination of vegetative bacteria, bacterial spores and background interferents are discussed. Applied technique is shown to be capable of distinguishing between vegetative bacteria, bacterial spores and fungi against other biological specimens. In addition, the results of initial studies on application of plasmonic nanostructures for enhancement of Raman scattering signals of bacterial cells are discussed. Our studies have shown that it is possible to obtain Raman scattering signal from single bacterial cell in presence of single plasmonic nanostructure. Show more

Keywords: SERS, FTIR, fungi, bacteria, PCA, hierarchical cluster analysis

DOI: 10.3233/BSI-130060

Citation: Biomedical Spectroscopy and Imaging, vol. 3, no. 1, pp. 29-39, 2014

Authors: Jenkins, Richard O. | Kwok, Rachel W.L. | Goncharov, Nikolay V. | Haris, Parvez I.

Article Type: Research Article

Abstract: BACKGROUND: Candida spp. of yeasts are a major cause of nosocomial infections in intensive care units, with Candida albicans the most commonly isolated yeast species. Phenotypic identification of Candida spp. is labour- and time consuming, while rapid direct intact cell MALDI-TOF-MS is emerging as a rapid tool for identifying microorganisms. OBJECTIVES: To optimise a MALDI-TOF-MS protocol for discrimination of yeasts, with evaluation of various chemical pretreatments of cells for enhancing spectral richness and discriminatory power. METHOD: MALDI-TOF-MS of C. albicans was optimised with respect to matrix chemical(s), matrix solvent and target plating method. Various chemical pretreatments (solvents, reductants, …detergents) and application methods were evaluated for enhancement of spectral richness. Selected pretreatments were applied to MALDI-TOF-MS discrimination of a set of clinical isolates comprising Candida spp. and Cryptococcus neoformans. RESULTS: The optimized MALDI-TOF-MS protocol involved α-cyano-4-hydroxycinnamic acid (CHCA) as matrix chemical (in 1:1 acenonitrile:H2 O and 0.3% trifluoroacetic acid), with target plating by a sandwich method. Methanol or formate:isopropanol pretreatment of cells in a direct target plate application method enhanced spectral richness. The latter pretreatment facilitated discrimination of a set of clinical isolates comprising Candida spp. (C. albicans, C. boidinii, C. glabrata, C. guilliermondii, C. krusei, C. parapsilosis, C. tropicalis) and Cryptococcus neoformans with 100% clustering accuracy. CONCLUSION: MALDI-TOF-MS discrimination of Candida spp. is enhanced through chemical pretreatment of cells; formate:isopropanol pretreatment, with CHCA as matrix chemical in a sandwich target plating method, is highlighted as a protocol affording the best discriminatory power. Show more

Keywords: MALDI-TOF-MS, Candida, Cryptococcus, yeasts

DOI: 10.3233/BSI-140065

Citation: Biomedical Spectroscopy and Imaging, vol. 3, no. 1, pp. 41-50, 2014

Authors: Henke, Katharina | Odermatt, Meike | Welte, Wolfram | Hauser, Karin

Article Type: Research Article

Abstract: TtoA is a major outer membrane protein (Omp) with β-barrel structure from the thermophilic eubacterium T. thermophilus. FT-IR spectroscopy and SDS PAGE analysis were used to monitor the stability of detergent-solubilised TtoA under denaturing conditions. Heat as well as the common denaturants urea and SDS were applied to affect the TtoA structure. The protein has proven to be extremely thermostable in its native form. Denaturants likewise only have little effects on the protein's structure. In detail, a SDS concentration of 1% as is typical for Laemmli buffer does not have an impact on the structure of TtoA, even in combination …with a temperature of 99°C. The same holds true for urea concentrations below 8 M. Only the combination of highly concentrated urea or SDS in combination with incubating the protein at 99°C for 10 minutes leads to a change of the secondary structure in TtoA. Show more

Keywords: β-barrel, infrared spectroscopy, stability, outer membrane protein

DOI: 10.3233/BSI-140063

Citation: Biomedical Spectroscopy and Imaging, vol. 3, no. 1, pp. 51-56, 2014

Authors: de la Arada, Igor | Celeiro, José | Gonzalez-Velasco, Javier | Bilbao, Pedro | Arrondo, Jose Luis R.

Article Type: Research Article

Abstract: Radiotherapy is widely used in cancer treatment, with a growing interest in knowing the effect of irradiation at cellular and molecular level. Keratinocyte cells from normal (HOK) or cancer (SCC25) cell lines have been subjected to different doses of radiation. Transglutaminase, is an enzyme involved in many cellular processes including apoptosis, sensitive to irradiation with the activity modified in cancer cells. The activity has been measured in both cell lines obtaining a 75% difference in activity, non-attributable to calcium. After subjecting the cells to different doses the activity at different times after irradiation shows that the response of normal and …cancer cells is not alike, being the TGase activity in cancer cells less affected by irradiation. In both cases the activity is recovered after 24 h. The effect of irradiation on TGase activity on a purified protein has also been studied not only measuring the activity, but also to the changes of structure using IR spectroscopy. There is less effect of irradiation in the activity and small changes in the components of the amide I band associated with protein structure. The results would suggest that the effect of radiation is also dependent on the cellular structure. Show more

Keywords: Radiotherapy, irradiation, keratinocyte cells, TGase activity, infrared spectroscopy

DOI: 10.3233/BSI-140064

Citation: Biomedical Spectroscopy and Imaging, vol. 3, no. 1, pp. 57-61, 2014

Authors: Dezhampanah, H. | Rad Chokami, Kh.

Article Type: Research Article

Abstract: In this study, we have investigated interaction of sertraline hydrochloride as antidepressant drug in pharmaceutical formulation with eosin Y dye in aqueous buffered medium by optical absorption and fluorescence spectroscopic measurement. Strong hypochromic–bathochromic effects in absorbance and quenching in fluorescence were observed that showed strong binding of eosin Y to this drug via ion pair formation. In order to explain the nature of eosin Y-drug interaction, the equilibrium constants and other thermodynamic functions for the process of eosin Y-sertraline ion pair formation were calculated using the UV-Visible absorption data. The results showed that formation of ion pair between eosin …Y and sertraline was exothermic, characterized by large negative enthalpy and positive entropy changes. Show more

Keywords: Eosin Y, sertraline hydrochloride, ion pair, equilibrium constant, fluorescence spectroscopy

DOI: 10.3233/BSI-140066

Citation: Biomedical Spectroscopy and Imaging, vol. 3, no. 1, pp. 63-71, 2014