R. Wu, Hai-Yuan Sun, Baoming Zhao, Geng Deng, Zhi‐Wu Yu
Structural properties of paeonol-encapsulated liposomes containing cholesterol or stigmasterol at 37°C have been investigated by synchrotron small-angle X-ray scattering (SAXS) and wide-angle X-ray scattering (WAXS) techniques. We compared the structural properties of pure dipalmitoylphosphatidylcholine (DPPC) liposomes, sterol–DPPC liposomes, and those of paeonol–sterol–DPPC liposomes at different molar ratios. Three conclusions can be drawn: First, phase separation occurs in both sterol–DPPC and paeonol–sterol–DPPC liposomes. Second, the incorporation of paeonol molecules into sterol– DPPC liposomes weakens the membrane order. Third, cholesterol has a stronger tendency to interact with DPPC as compared to its counterpart in plant, stigmasterol.
{"title":"Structural properties of paeonol encapsulated liposomes at physiological temperature: Synchrotron small-angle and wide-angle X-ray diffraction studies","authors":"R. Wu, Hai-Yuan Sun, Baoming Zhao, Geng Deng, Zhi‐Wu Yu","doi":"10.3233/BSI-160162","DOIUrl":"https://doi.org/10.3233/BSI-160162","url":null,"abstract":"Structural properties of paeonol-encapsulated liposomes containing cholesterol or stigmasterol at 37°C have been investigated by synchrotron small-angle X-ray scattering (SAXS) and wide-angle X-ray scattering (WAXS) techniques. We compared the structural properties of pure dipalmitoylphosphatidylcholine (DPPC) liposomes, sterol–DPPC liposomes, and those of paeonol–sterol–DPPC liposomes at different molar ratios. Three conclusions can be drawn: First, phase separation occurs in both sterol–DPPC and paeonol–sterol–DPPC liposomes. Second, the incorporation of paeonol molecules into sterol– DPPC liposomes weakens the membrane order. Third, cholesterol has a stronger tendency to interact with DPPC as compared to its counterpart in plant, stigmasterol.","PeriodicalId":44239,"journal":{"name":"Biomedical Spectroscopy and Imaging","volume":"5 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2016-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.3233/BSI-160162","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"69857361","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
A. Elka, Violetta Moulia, P. Spyridonos, N. Kourkoumelis
BACKGROUND: The successful discrimination of the subtle spectral characteristics of human skin in Raman spectra requires optimal acquisition parameters. We explore the translational momentum of Raman spectroscopy towards clinical practice by fine-tuning two basic experimental parameters (irradiance and integration time) of a portable Raman system used in skin measurements. OBJECTIVE: The aim of this study is to construct a generic protocol for recording the optimal Raman signal for in vivo skin measurements. METHODS: In vivo spectra were collected from two individuals of normal Fitzpatrick type III skin type. We assessed two different irradiation setups with three different integration times each by separating the raw signal from the noise using multivariate analysis. RESULTS: Our results showed that under a time threshold no optimal measurement conditions can be achieved. On the other hand, increased laser power and acquisition time do not offer a significant advantage over the selected lower values. Baseline correction is the most critical component for analysing normalized skin Raman spectra. CONCLUSIONS: A simple working protocol based on multivariate statistics offers the relative adjustment of irradiance and signal integration time among other experimental parameters that must be examined for optimal Raman measurements of skin.
{"title":"The effect of irradiance and integration time in in vivo normal skin Raman measurements assessed by multivariate statistical analysis","authors":"A. Elka, Violetta Moulia, P. Spyridonos, N. Kourkoumelis","doi":"10.3233/BSI-160140","DOIUrl":"https://doi.org/10.3233/BSI-160140","url":null,"abstract":"BACKGROUND: The successful discrimination of the subtle spectral characteristics of human skin in Raman spectra requires optimal acquisition parameters. We explore the translational momentum of Raman spectroscopy towards clinical practice by fine-tuning two basic experimental parameters (irradiance and integration time) of a portable Raman system used in skin measurements. OBJECTIVE: The aim of this study is to construct a generic protocol for recording the optimal Raman signal for in vivo skin measurements. METHODS: In vivo spectra were collected from two individuals of normal Fitzpatrick type III skin type. We assessed two different irradiation setups with three different integration times each by separating the raw signal from the noise using multivariate analysis. RESULTS: Our results showed that under a time threshold no optimal measurement conditions can be achieved. On the other hand, increased laser power and acquisition time do not offer a significant advantage over the selected lower values. Baseline correction is the most critical component for analysing normalized skin Raman spectra. CONCLUSIONS: A simple working protocol based on multivariate statistics offers the relative adjustment of irradiance and signal integration time among other experimental parameters that must be examined for optimal Raman measurements of skin.","PeriodicalId":44239,"journal":{"name":"Biomedical Spectroscopy and Imaging","volume":"5 1","pages":"217-223"},"PeriodicalIF":0.0,"publicationDate":"2016-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.3233/BSI-160140","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"69856496","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
R. Kiselev, I. Schie, S. Aškrabić, C. Krafft, J. Popp
Typical commercial Raman micro-spectroscopic systems do not offer much flexibility to the end user, thus limiting potential research applications. We present a design of a simple, highly flexible and portable confocal Raman microscope with a detailed list of parts. The system can perform spectral acquisition in different modes: single-point spectroscopy, hyperspectral point mapping or hyperspectral line mapping. Moreover, the microscope can be easily converted between inverted and upright configurations, which can be beneficial for specific situations. Fiber coupling enables to connect various lasers for excitation and spectrometer/CCD combinations for signal detection. The performance of the instrument is demonstrated via Raman spectroscopy at 785 nm excitation wavelength, single point mapping of pancreatic cancer cells placed onto a quartz substrate and line mapping of polystyrene beads.
{"title":"Design and first applications of a flexible Raman micro-spectroscopic system for biological imaging","authors":"R. Kiselev, I. Schie, S. Aškrabić, C. Krafft, J. Popp","doi":"10.3233/BSI-160141","DOIUrl":"https://doi.org/10.3233/BSI-160141","url":null,"abstract":"Typical commercial Raman micro-spectroscopic systems do not offer much flexibility to the end user, thus limiting potential research applications. We present a design of a simple, highly flexible and portable confocal Raman microscope with a detailed list of parts. The system can perform spectral acquisition in different modes: single-point spectroscopy, hyperspectral point mapping or hyperspectral line mapping. Moreover, the microscope can be easily converted between inverted and upright configurations, which can be beneficial for specific situations. Fiber coupling enables to connect various lasers for excitation and spectrometer/CCD combinations for signal detection. The performance of the instrument is demonstrated via Raman spectroscopy at 785 nm excitation wavelength, single point mapping of pancreatic cancer cells placed onto a quartz substrate and line mapping of polystyrene beads.","PeriodicalId":44239,"journal":{"name":"Biomedical Spectroscopy and Imaging","volume":"5 1","pages":"115-127"},"PeriodicalIF":0.0,"publicationDate":"2016-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.3233/BSI-160141","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"69856509","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
K. M. Khan, Ragesh Kumar, Hemant Krishna, K. D. Rao, S. Majumder
{"title":"A dual-modal optical system combining depth-sensitive laser induced fluorescence (LIF) spectroscopy and optical coherence tomography (OCT) for analyzing layered biological tissue","authors":"K. M. Khan, Ragesh Kumar, Hemant Krishna, K. D. Rao, S. Majumder","doi":"10.3233/BSI-160147","DOIUrl":"https://doi.org/10.3233/BSI-160147","url":null,"abstract":"","PeriodicalId":44239,"journal":{"name":"Biomedical Spectroscopy and Imaging","volume":"5 1","pages":"313-324"},"PeriodicalIF":0.0,"publicationDate":"2016-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.3233/BSI-160147","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"69856864","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Cholesterol, an essential component of higher eukaryotic membranes, was discovered more than two centuries ago. The development and progress of cholesterol research in the last 200 years has been truly fascinating, with elements of surprise, serendipity and intrigue. In this review, we trace this journey the way we see it, and follow it up with the role of membrane cholesterol in crucial areas of contemporary research (transbilayer domains, regulation of GPCR function and role in the entry of intracellular pathogens into host cells), with considerable footprint from our work. We believe that cholesterol will continue to surprise and fascinate future researchers, thereby justifying its evergreen nature.
{"title":"Cholesterol: An evergreen molecule in biology","authors":"G. Kumar, A. Chattopadhyay","doi":"10.3233/BSI-160159","DOIUrl":"https://doi.org/10.3233/BSI-160159","url":null,"abstract":"Cholesterol, an essential component of higher eukaryotic membranes, was discovered more than two centuries ago. The development and progress of cholesterol research in the last 200 years has been truly fascinating, with elements of surprise, serendipity and intrigue. In this review, we trace this journey the way we see it, and follow it up with the role of membrane cholesterol in crucial areas of contemporary research (transbilayer domains, regulation of GPCR function and role in the entry of intracellular pathogens into host cells), with considerable footprint from our work. We believe that cholesterol will continue to surprise and fascinate future researchers, thereby justifying its evergreen nature.","PeriodicalId":44239,"journal":{"name":"Biomedical Spectroscopy and Imaging","volume":"5 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2016-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.3233/BSI-160159","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"69856799","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Membrane proteins facilitate some of the most important cellular processes including energy conversion, ion trans- port 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, atten- uated 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.
{"title":"The early development and application of FTIR difference spectroscopy to membrane proteins: A personal perspective","authors":"K. Rothschild","doi":"10.3233/BSI-160148","DOIUrl":"https://doi.org/10.3233/BSI-160148","url":null,"abstract":"Membrane proteins facilitate some of the most important cellular processes including energy conversion, ion trans- port 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, atten- uated 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.","PeriodicalId":44239,"journal":{"name":"Biomedical Spectroscopy and Imaging","volume":"5 1","pages":"231-267"},"PeriodicalIF":0.0,"publicationDate":"2016-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.3233/BSI-160148","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"69856960","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
J. D. Meutter, Kheiro-Mouna Derfoufi, E. Goormaghtigh
BACKGROUND: Proteins are sensitive to environmental conditions. Whether they are produced for therapeutic purposes or for fundamental research, the integrity of their structure and post-traductional modifications are key issues. Measuring glycosylation or phosphorylation level as well as their secondary structure most often rely on complex and indirect experiments. Infrared spectroscopy presents a series of advantages related to its multivariate character. There is a lack of high-throughput methods able to analyse these parameters. OBJECTIVE: In this paper we attempted to combine protein microarrays and infrared imaging for high throughput analysis of proteins. METHODS: A protein microarrayer was used to produce protein microarrays on BaF2 slides transparent in the mid-infrared. Spot density was about 25 spots/mm 2 . A 128 × 128 focal plane array infrared detector was used to record images of the protein microarrays. RESULTS: We show that 100 µm diameter spot are easily analyzed. Spots obtained with low protein concentrations, resulting in an average of a single protein monolayer (ca 3 fg/µm 2 for a 66 kDa protein) provided good quality spectra. CONCLUSIONS: Infrared imaging is a label free, high throughput method, able to analyse protein microarrays and to take advantage from the wide information available in the infrared spectra.
{"title":"Analysis of protein microarrays by FTIR imaging","authors":"J. D. Meutter, Kheiro-Mouna Derfoufi, E. Goormaghtigh","doi":"10.3233/BSI-160137","DOIUrl":"https://doi.org/10.3233/BSI-160137","url":null,"abstract":"BACKGROUND: Proteins are sensitive to environmental conditions. Whether they are produced for therapeutic purposes or for fundamental research, the integrity of their structure and post-traductional modifications are key issues. Measuring glycosylation or phosphorylation level as well as their secondary structure most often rely on complex and indirect experiments. Infrared spectroscopy presents a series of advantages related to its multivariate character. There is a lack of high-throughput methods able to analyse these parameters. OBJECTIVE: In this paper we attempted to combine protein microarrays and infrared imaging for high throughput analysis of proteins. METHODS: A protein microarrayer was used to produce protein microarrays on BaF2 slides transparent in the mid-infrared. Spot density was about 25 spots/mm 2 . A 128 × 128 focal plane array infrared detector was used to record images of the protein microarrays. RESULTS: We show that 100 µm diameter spot are easily analyzed. Spots obtained with low protein concentrations, resulting in an average of a single protein monolayer (ca 3 fg/µm 2 for a 66 kDa protein) provided good quality spectra. CONCLUSIONS: Infrared imaging is a label free, high throughput method, able to analyse protein microarrays and to take advantage from the wide information available in the infrared spectra.","PeriodicalId":44239,"journal":{"name":"Biomedical Spectroscopy and Imaging","volume":"5 1","pages":"145-154"},"PeriodicalIF":0.0,"publicationDate":"2016-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.3233/BSI-160137","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"69856826","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
C. Tripon, C. Muntean, E. Surducan, I. Bratu, A. Halmagyi, A. Coste
{"title":"Structural response of genomic DNA from grapevine (Vitis vinifera L.) varieties to microwaves irradiation: A Fourier transform infrared spectroscopy assessment","authors":"C. Tripon, C. Muntean, E. Surducan, I. Bratu, A. Halmagyi, A. Coste","doi":"10.3233/BSI-160138","DOIUrl":"https://doi.org/10.3233/BSI-160138","url":null,"abstract":"","PeriodicalId":44239,"journal":{"name":"Biomedical Spectroscopy and Imaging","volume":"5 1","pages":"295-312"},"PeriodicalIF":0.0,"publicationDate":"2016-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.3233/BSI-160138","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"69856884","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
J. Ollesch, D. Theegarten, M. Altmayer, K. Darwiche, T. Hager, G. Stamatis, K. Gerwert
BACKGROUND: Lung cancer is the leading cause of death for male and female cancer patients alike. Early diagnosis improves prognosis. A blood test would be a valuable support. OBJECTIVE: Infrared spectroscopy provides a label-free biochemical fingerprint of a sample. A study was conducted on 161 patients with initial cancer suspicion to identify and verify spectral biomarker candidate patterns to detect non-small cell lung carcinoma (NSCLC). METHODS: Blood serum and plasma samples were analysed with an automated FTIR spectroscopic system. Two pattern recognition algorithms and two classifiers were applied. Monte Carlo cross validation was performed with linear discriminant analysis and random forest classification. RESULTS: Marker patterns for the discrimination of cancer from clinically relevant disease control patients were identified in FTIR spectra of blood samples. An accuracy of up to 79% was achieved. Squamous cell and adenocarcinoma patients were separable with an accuracy of 80%. CONCLUSIONS: The study demonstrates the applicability of FTIR spectroscopic blood testing for lung cancer detection. Evidence for cancer subtype discrimination is given. With an improved performance, the method could be developed as a routine diagnostic tool for blood testing detecting NSCLC.
{"title":"An infrared spectroscopic blood test for non-small cell lung carcinoma and subtyping into pulmonary squamous cell carcinoma or adenocarcinoma","authors":"J. Ollesch, D. Theegarten, M. Altmayer, K. Darwiche, T. Hager, G. Stamatis, K. Gerwert","doi":"10.3233/BSI-160144","DOIUrl":"https://doi.org/10.3233/BSI-160144","url":null,"abstract":"BACKGROUND: Lung cancer is the leading cause of death for male and female cancer patients alike. Early diagnosis improves prognosis. A blood test would be a valuable support. OBJECTIVE: Infrared spectroscopy provides a label-free biochemical fingerprint of a sample. A study was conducted on 161 patients with initial cancer suspicion to identify and verify spectral biomarker candidate patterns to detect non-small cell lung carcinoma (NSCLC). METHODS: Blood serum and plasma samples were analysed with an automated FTIR spectroscopic system. Two pattern recognition algorithms and two classifiers were applied. Monte Carlo cross validation was performed with linear discriminant analysis and random forest classification. RESULTS: Marker patterns for the discrimination of cancer from clinically relevant disease control patients were identified in FTIR spectra of blood samples. An accuracy of up to 79% was achieved. Squamous cell and adenocarcinoma patients were separable with an accuracy of 80%. CONCLUSIONS: The study demonstrates the applicability of FTIR spectroscopic blood testing for lung cancer detection. Evidence for cancer subtype discrimination is given. With an improved performance, the method could be developed as a routine diagnostic tool for blood testing detecting NSCLC.","PeriodicalId":44239,"journal":{"name":"Biomedical Spectroscopy and Imaging","volume":"5 1","pages":"129-144"},"PeriodicalIF":0.0,"publicationDate":"2016-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.3233/BSI-160144","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"69856592","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
This review summarises our infrared spectroscopy and density functional theory studies on the mutual interactions between enzymes and their substrates. We investigated phosphoenolpyruvate bound to ...
本文综述了红外光谱和密度泛函理论在酶与底物相互作用方面的研究进展。我们研究了磷酸烯醇丙酮酸结合…
{"title":"Two sides of the same coin : How enzymes distort substrates and vice versa. An infrared spectroscopic view on pyruvate kinase and Ca2+-ATPase","authors":"A. Barth","doi":"10.3233/BSI-160134","DOIUrl":"https://doi.org/10.3233/BSI-160134","url":null,"abstract":"This review summarises our infrared spectroscopy and density functional theory studies on the mutual interactions between enzymes and their substrates. We investigated phosphoenolpyruvate bound to ...","PeriodicalId":44239,"journal":{"name":"Biomedical Spectroscopy and Imaging","volume":"5 1","pages":"101-114"},"PeriodicalIF":0.0,"publicationDate":"2016-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.3233/BSI-160134","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"69856308","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}