Biomedical Spectroscopy and Imaging - Volume 5, issue 3

Authors: Haris, Parvez I.

Article Type: Research Article

DOI: 10.3233/BSI-160150

Citation: Biomedical Spectroscopy and Imaging, vol. 5, no. 3, pp. 225-230, 2016

Authors: Rothschild, Kenneth J.

Article Type: Review Article

Abstract: Membrane proteins facilitate some of the most important cellular processes including energy conversion, ion transport and signal transduction. While conventional infrared absorption provides information about membrane protein secondary structure, a major challenge is to develop a dynamic picture of the functioning of membrane proteins at the molecular level. The introduction of FTIR difference spectroscopy around 1980 to study structural changes in membrane proteins along with a number of associated techniques including protein isotope labeling, site-directed mutagenesis, polarization dichroism, attenuated total reflection and time-resolved spectroscopy have led to significant progress towards this goal. It is now possible to routinely detect conformational …changes of individual amino acid residues, backbone peptides, binding ligands, chromophores and even internal water molecules under physiological conditions with time-resolution down to nanoseconds. The advent of ultrafast pulsed-IR lasers has pushed this time-resolution down to femtoseconds. The early development of FTIR difference spectroscopy as applied to membrane proteins with special focus on bacteriorhodopsin is reviewed from a personal perspective. Show more

Keywords: Infrared spectroscopy, FTIR difference spectroscopy, Raman spectroscopy, retinal, rhodopsin, bacteriorhodopsin, membrane proteins

DOI: 10.3233/BSI-160148

Citation: Biomedical Spectroscopy and Imaging, vol. 5, no. 3, pp. 231-267, 2016

Authors: Kato, Yuki | Noguchi, Takumi

Article Type: Research Article

Abstract: Photosystem II (PSII) in plants and cyanobacteria performs light-driven water oxidation to obtain electrons necessary for CO2 fixation. In PSII, a series of electron transfer reactions take place from the Mn4 CaO5 cluster, the catalytic site of water oxidation, to a plastoquinone molecule via several redox cofactors. Light-induced Fourier transform infrared (FTIR) difference spectroscopy has been extensively used to investigate the structures and reactions of the redox cofactors in PSII. Recently, FTIR spectroelectrochemistry combined with the light-induced difference technique was applied to study the mechanism of electron-transfer regulation in PSII involving the quinone electron acceptors, QA and …QB , and the non-heme iron that bridges them. In this mini-review, this combined FTIR method is introduced, and obtained results about the redox reactions of the non-heme iron and QB , involving the long-range interaction of the Mn4 CaO5 cluster with the electron-acceptor side, are summarized. Show more

Keywords: Electron transfer, FTIR, photosynthesis, quinone, redox potential, spectroelectrochemistry

DOI: 10.3233/BSI-160146

Citation: Biomedical Spectroscopy and Imaging, vol. 5, no. 3, pp. 269-282, 2016

Authors: Stothers, Lynn | Macnab, Andrew

Article Type: Review Article

Abstract: Voiding dysfunction occurs due to the interplay of anatomic, physiologic and functional elements. Hence, integration of new imaging and spectroscopy modalities offers the potential for improving patient assessment by enabling the causal structural defects, formal staging of pelvic floor dysfunction and underlying physiologic mechanisms to be better defined. The purpose of this review is to outline the limitations of current imaging, and highlight the advantages of newer technologies in the evaluation of patients with voiding dysfunction due to loss of structural integrity of the pelvic floor.

Keywords: fNIRS, fMRI, MRI, MRO, NIRS, pelvis, prolapse, voiding dysfunction

DOI: 10.3233/BSI-160149

Citation: Biomedical Spectroscopy and Imaging, vol. 5, no. 3, pp. 283-294, 2016

Authors: Tripon, Carmen | Muntean, Cristina M. | Surducan, Emanoil | Bratu, Ioan | Halmagyi, Adela | Coste, Ana

Article Type: Research Article

Abstract: In this work, Fourier transform infrared (FT-IR) spectra of untreated and microwaves irradiated genomic DNAs extracted from leaves of different grapevine varieties, respectively, have been analyzed between 1800–800 cm−1 , in order to investigate their screening characteristic features and their structural response to microwaves treatment at 869–894 MHz frequency band. FT-IR vibrational modes for each of these cases, spectroscopic band assignments and structural interpretations of genomic DNAs are reported. No significant microwaves damage, concerning DNA bases structure, base pairing and base unstacking was found. Conformational changes of specific DNA segments and effects on deoxyribose seem to appear after microwaves irradiation. Grapevine varieties …dependent microwaves influence on the structure of DNA has been found. Best nucleic acids structural tolerance upon microwave irradiation, as compared with the non-exposed DNA has been found in the case of genomic DNA isolated from ‘Chasselas Doré’ grapevine variety. Show more

Keywords: Genomic DNA, grapevine varieties, FT-IR spectroscopy, microwaves irradiation

DOI: 10.3233/BSI-160138

Citation: Biomedical Spectroscopy and Imaging, vol. 5, no. 3, pp. 295-312, 2016

Authors: Khan, Khan Mohd. | Kumar, Ragesh | Krishna, Hemant | Rao, K. Divakar | Majumder, Shovan K.

Article Type: Research Article

Abstract: Background: There is a significant current interest in combining multiple modalities in a single optical system for a more complete characterization of tissue for improved diagnosis. Objective: We report development of a dual-modal optical system combing the depth-sensitive laser induced fluorescence (LIF) spectroscopy and optical coherence tomography (OCT) for analysis of layered biological tissues. Methods: A time-domain, real-time OCT system, assembled in-house, was used as the platform for developing the dual-modal system. It involved appropriate modification of the sample arm of the OCT for making the LIF excitation beam (337 nm) collinear with the OCT illumination …beam (1310 nm) and implementation of a confocal fluorescence configuration for rejecting the out-of-focus fluorescence light. Results: The system was first validated using a layered non-biological phantom prepared by placing a thin layer of tissue paper pasted over a green dye card of much larger thickness. A good correlation was observed between the OCT images and the fluorescence signal. The system was also used to record OCT images and fluorescence spectra from a chicken leg tissue covered with a thin layer of epithelial membrane. While OCT images showed the presence of two distinct layers, fluorescence spectra measured from these layers confirmed the biochemical difference between the two. Conclusions: In contrast to the dual-modal LIF-OCT systems reported earlier, the present system can sequentially record fluorescence signal and the OCT image from the same depth of a tissue sample thereby showing its potential for obtaining at once both morphological as well as biochemical information of the tissue layer from that depth. Show more

Keywords: Dual-modal system, combined LIF-OCT, depth-sensitive fluorescence spectra, layered tissue, NA

DOI: 10.3233/BSI-160147

Citation: Biomedical Spectroscopy and Imaging, vol. 5, no. 3, pp. 313-324, 2016