Biomedical Spectroscopy and Imaging - Volume 3, issue 3
Purchase individual online access for 1 year to this journal.
Price: EUR 110.00
Biomedical Spectroscopy and Imaging (BSI) is a multidisciplinary journal devoted to the timely publication of basic and applied research that uses spectroscopic and imaging techniques in different areas of life science including biology, biochemistry, biotechnology, bionanotechnology, environmental science, food science, pharmaceutical science, physiology and medicine. Scientists are encouraged to submit their work for publication in the form of original articles, brief communications, rapid communications, reviews and mini-reviews.
The journal is dedicated to providing a single forum for experts in spectroscopy and imaging as applied to biomedical problems, and also for life scientists who use these powerful methods for advancing their research work. BSI aims to promote communication, understanding and synergy across the diverse disciplines that rely on spectroscopy and imaging. It also encourages the submission of articles describing development of new devices and technologies, based on spectroscopy and imaging methods, for application in diverse areas including medicine, biomedical science, biomaterials science, environmental science, pharmaceutical science, proteomics, genomics, metabolomics, microbiology, biotechnology, genetic engineering, nanotechnology, etc.
Abstract: Infrared absorption spectra of carbon monoxide molecule coordinated by the heme iron of carbonmonoxy heme proteins are widely used to study their structure and dynamics. In this paper we use results of X-ray study of carbonmonoxy myoglobin to elucidate the structures of spectroscopically observed conformational substates of this protein. It is shown that A3 substate corresponds to the structure with water molecule hydrogen bonded to the distal histidine, whereas in the A1 conformation this molecule is absent. We also show that redistribution of electronic density of the distal histidine and the water molecule as a result of their…interaction must be taken into account when predicting their positions in the heme pocket.
Keywords: Myoglobin, infrared, protein dynamics, conformational substates
Abstract: BACKGROUND: The rabbit Vx2 liver tumor is a fast-growing carcinoma model commonly used to study tumor behaviours under cancer treatments. The reduction of tumor viability and the degree of induced necrosis are the common criteria to evaluate the efficacy of cancer treatments. Currently, it is not easy to perform a rapid and reproducible tissue quantification by histopathological analysis. OBJECTIVE: Our objective was to use infrared-imaging combined with linear-discriminant-analysis model (LDA) to automatically quantify the necrotic effect induced by doxorubicin-eluting-implants (DEI) on a Vx2 liver tumors model. METHODS: Three rabbits were subjected to DEI treatment and compared to a…control group (CTRL) of nine rabbits. Tumor bearing livers were resected, fixed in formalin and embedded in paraffin. On two consecutive sections, we performed hematoxylin–eosin–saffron (HES) staining and infrared-imaging. Infrared-images were then subjected to the LDA-model analysis. RESULTS: The LDA and HES images strongly correlated for viable and necrotic tumor tissues. For the DEI group, the model determined that the surface of viable tumor represented 0.24±5% of the tumor (CTRL: 55.71±17%, P<0.0001) and the necrotic tissue 66.46±20% of the tumor (CTRL: 18.45±12%, P<0.0001). CONCLUSIONS: Our results showed that infrared-imaging coupled with LDA-model analysis could be a helpful to easily and objectively assess the treatment efficacy.
Abstract: This work brings together previous work on catechol (1,2-dihydroxybenzene) and resorcinol (1,3-dihydroxybenzene) with recent results from experiments on hydroquinone (1,4-dihydroxybenzene). The experiments utilise time-resolved ion yield and velocity map imaging techniques to demonstrate how the position of the OH functional groups influences the excited state dynamics of these molecules. The mechanisms responsible for these dynamics are explored, with the focus on H-atom tunnelling mediated photodissociation. In all cases, tunnelling occurs beneath a conical intersection formed between the excited 11 ππ* state and the 11 πσ* state, which is dissociative along the O–H stretch coordinate. Tunnelling beneath this barrier yields high…kinetic energy (~5000–7000 cm−1 ) H-atoms. The excited state lifetime of these molecules ranges from hundreds of femtoseconds to several nanoseconds and is found to be dependent on excitation energy as well as the relative positions of the OH functional groups.
Abstract: BACKGROUND: During pathological and/or physiological processes, such as tumoral progression or aging, human skin undergoes molecular and structural changes mainly due to alterations of dermal structural proteins such as type I collagen. These modifications in dermis are probably due to collagen fibers rearrangement and reorientation which have not been thoroughly studied up to now. FT-IR (Fourier transform infrared) microspectroscopy associated to polarization measurement appears as an interesting method to determine in situ the alignment of type I collagen fibers. OBJECTIVE: In this paper, two different clustering algorithms were applied to determine different layers in human skin. Besides, we used…polarized FT-IR imaging to evaluate the molecular organization of dermal collagen. METHODS: To do this, a cryosection of skin from 48-year-old woman was analyzed. Acquired FT-IR images were firstly processed using K-means and fuzzy C-means (FCM). FCM was chosen on polarized FT-IR images in order to highlight the molecular orientation of dermal collagen fibrils. The ratio of Amide I/Amide II bands integrated intensities was computed in order to assess the orientation of collagen fibrils. RESULTS AND CONCLUSION: This methodology permitted to reveal the potential of polarized FT-IR microspectroscopy for the characterization of type I collagen network in human skin. Our approach could help to find innovative applications in dermatology as well as in cosmetics.
Keywords: Polarized FT-IR imaging, type I collagen, collagen orientation, clustering methods
Abstract: Disulfide bridges of bovine α-thrombin are studied using the analysis of the Raman spectral features in the spectral interval 500–550 cm−1 . The changes under study are caused by the transitions from lyophilized state to the native solution in PBS with a protein concentration of 2.8 mM (100 mg/ml) and from native solution to solution with partially reduced disulfide bridges. The reduction takes place when dithiothreitol (DTT) is added to the sample.
Abstract: BACKGROUND: The techniques of second harmonic generation (SHG) and two-photon excitation of fluorescence microscopy (TPEFM) have shown as powerful tools to investigate collagen and extracellular matrix components. OBJECTIVE: The aim of this study is evaluate the feasibility of using femtosecond lasers of high intensity as an auxiliary treatment of burn patients using an in vivo model, monitoring and characterizing the healing process by histology and SHG+TPEFM. METHODS: Samples from three dorsum areas of Wistar rats anaesthetized were burned by water vapour exposure and treated by debridement and laser ablation at the third day post burned. To differentiating the…healing process, skin fresh biopsies at four different days of study were evaluated by histology, TPEFM and SHG. RESULTS: Changes in the skin caused by vapour exposure were observed by histological images and characterized by TPEFM+SHG images. The healing process of burned skin was observed by regeneration of its morphology comparing histological images. The integrity of collagen and components of extracellular matrix are evidence of a normal skin detected by TPEFM+SHG. CONCLUSIONS: The methods used to characterize the tissue are useful to validate the femtosecond lasers ablation treatment of burned skin.
Abstract: The use of lasers on bone cut can provide a series of advantages for both the surgeon and the patient. However, for a safe and efficient application it is necessary to know the exact effects that the laser causes in the bone tissue. The aim of this work was to study the effects of Er,Cr:YSGG irradiation in bone tissue using the ATR-FTIR technique. Pieces of tibia rabbit bone were divided in six groups with three samples per group. In one of the groups the samples did not undergo any treatment; in the others the samples were laser irradiated with different…energy densities. The infrared spectra acquisition was made using an ATR accessory. For a semi-quantitative analysis, the area under each band was calculated and normalized by the phosphate band area of the same spectrum. The results showed a gradual material loss as the energy density increased in the bands of water, amide I, and carbonate, amide II, amide II and collagen. This is probably caused by the temperature rise due to laser irradiation. These results are the first steps in testing the Er,Cr:YSGG laser efficacy as a cutting tool, a pivotal aspect of its consolidation in clinical procedures.