bluuebunny/crossref_metadata_2025_split huggingface dataset:
Fluorescence Spectroscopy In Vivo
Authors: Ramanujam Nirmala 
Published: September 2006

AbstractDiagnostic techniques based on optical spectroscopy have the potential to link the biochemical and morphological properties of tissues to individual patient care. In particular, these techniques are fast, noninvasive and quantitative. Furthermore, they can be used to elucidate key tissue features, such as the cellular metabolic rate, vascularity, intravascular oxygenation and alterations in tissue morphology. These tissue features can be interpreted to shed light on a variety of clinical problems, such as precancerous and cancerous growth and atherosclerosis. The goal of this report is to review the development and application of optical spectroscopy in the ultraviolet (UV) and visible (VIS) spectral regions, as a diagnostic tool in clinical applications. A particular emphasis is placed on steady‐state, UV/VIS fluorescence spectroscopy for the detection of precancers and cancers, in vivo.
Glucose, In Vivo Assay of
Authors: Heise H.M. 
Published: September 2006

AbstractIn vivo glucose sensing and regulation is necessary for patients with carbohydrate metabolism disorders, particularly those caused by diabetes mellitus. Self‐monitoring of blood glucose is part of the daily routine for such patients, and the measurement of capillary blood glucose, using different enzymatic assays in combination with photometric or electrochemical detection, still remains the standard method. Research activities concentrate on developing minimally invasive and noninvasive methodologies, the latter being based on spectroscopic techniques exploiting optical glucose specific characteristics, i.e. wavelength‐dependent absorptivities and refractive indices, mainly in the near‐infrared (NIR), or the rotation of linearly polarized radiation in the visible range. Owing to the complexity of the integrally probed tissue, and the presence of many interfering compounds, only multivariate spectroscopic measurement strategies, using several wavelengths, can be used for a noninvasive in vivo assay of glucose. Further complications arise from the heterogeneous distribution of glucose in the intravascular, interstitial and intracellular space and differences in their dynamics. In contrast to the established reference methodology which uses capillary blood, especially for the hypoglycemic concentration range, the imprecision observed so far within several experimental optical approaches is regarded as unacceptable for patient self‐monitoring. Further research is needed to establish an in vivo glucose assay for diabetic patients, or for direct monitoring in intensive care units and operating theatres, based on optical spectroscopy.
Infrared Spectroscopy in Clinical and Diagnostic Analysis
Authors: Shaw R. Anthony , Mantsch Henry H. 
Published: September 2006

Abstract
The infrared spectrum of a mixture serves as the basis to quantitate its constituents, and a number of common clinical chemistry tests have proven to be feasible using this approach. This article reviews the infrared spectroscopy‐based analytical methods that have been developed for consideration as clinical assays, including serum analysis, urine analysis, amniotic fluid assays for the estimation of fetal lung maturity, and others. Because of the widespread interest in the potential for in vivo measurement of blood glucose using near‐infrared spectroscopy, a separate section is devoted to the analysis of glucose in whole blood.
A related technique uses the infrared spectrum of biomedical specimens directly as a diagnostic tool. For example, the spectra of serum and of synovial fluid have proven to be useful in the diagnosis of metabolic disorders and arthritis, respectively, without explicitly recovering their chemical composition from the spectra. Rather, characteristic spectral features and patterns have been identified as the basis to distinguish spectra corresponding to healthy patients from those corresponding to diseased patients. These applications are reviewed here.
Issues such as ease of use, speed, reliability, sample size, and calibration stability all play important roles in governing the practical acceptability of infrared spectroscopy‐based analytical methods. To provide a framework to illustrate these issues, descriptions are included for the various procedures that have been explored to wed successfully infrared spectroscopy to clinical chemistry.
Infrared Spectroscopy, Ex Vivo Tissue Analysis by
Authors: Jackson Michael , Mantsch Henry H. 
Published: September 2006

Abstract
Infrared (IR) spectroscopy provides information relating to the vibration of covalent bonds within molecules. The wavelength of light absorbed by a vibrating bond depends upon the atoms in the bond, the type of bond, the type of vibration and inter‐ and intramolecular interactions. For complex samples such as human tissues an IR spectrum therefore provides a direct indication of sample biochemistry. With the correct choice of sampling methodology (usually an IR microscope) information on the biochemical nature of disease states can be obtained from tissue samples, which can often be useful diagnostically. Variations in spectral signatures arising from nucleic acids, proteins and lipids can provide important information in a number of disease states, including Alzheimer's disease (AD), breast cancer and skin cancer.
The information obtained by IR spectroscopy is difficult to obtain with many other instrumental techniques. For example the signal‐to‐noise ratio obtained by IR microscopy is far superior to that seen with Raman methods, allowing more sophisticated data processing and so more information to be extracted. Furthermore, many species of interest cannot be studied in situ with other techniques. Nucleic acids are a case in point. Powerful techniques such as nuclear magnetic resonance spectroscopy provide no information concerning this material, while Raman techniques only provide information relating to individual nucleotides. In contrast, DNA and RNA give rise to IR signatures that provide information relating to nucleic acid content/structure.
To appreciate fully the information contained in the complex spectra obtained from human tissues and cells, a unique combination of expertise in spectroscopy, biochemistry and anatomy/histology is required. This combination allows the investigator to avoid potential artefacts due to incorrect sampling and spatial variations in sample composition and to attribute the major absorptions present in spectra to individual biochemical species. However, spectral interpretation is often a highly subjective process, a fact that is made worse when one considers that many thousands of spectra are often acquired from a single tissue section. The application of pattern recognition techniques to IR data removes this subjectivity and allows realistic processing of these large data sets. In addition, many new methods are being developed which allow presentation of these complex data sets in a form readily interpreted by the nonexpert.
Magnetic Resonance in Medicine, High Resolution Ex Vivo
Authors: Smith Ian C. , Blandford Dorothea E. 
Published: September 2006

AbstractNuclear magnetic resonance (NMR) spectroscopy, or magnetic resonance spectroscopy (MRS), is a powerful physical technique to determine the quantity and structure of chemical compounds in a specimen. It involves the interaction of radiofrequency (RF) electromagnetic radiation with a collection of nuclei immersed in a strong magnetic field. It is unique in its ability to provide nondestructive chemical analyses in vivo and in vitro. Moreover, no or very little pretreatment of the specimen is required prior to making a measurement. Spectra take only a few minutes to acquire, and it is not necessary to preselect the metabolites of interest in order to detect and quantify them. Its limitations are a lack of availability of instruments and large databases of spectral changes correlated with pathological conditions, and a detection sensitivity of approximately 1 µM.
Near‐Infrared Spectroscopy, In Vivo Tissue Analysis by
Authors: Sowa Michael G. , Leonardi Lorenzo , Matas Anna , Schattka Bernie J. , Hewko Mark D. , Payette Jeri R. , Mantsch Henry H. 
Published: September 2006

AbstractIn vivo near‐infrared (NIR) spectroscopy has the potential of becoming an important tool in a number of areas in clinical medicine. Technological developments in photonics that have been spurred on by the communication revolution have set the stage for rapid advancement of optical and NIR spectroscopy based on noninvasive or minimally invasive medical diagnostic techniques. The goal of this article is to review the current capabilities and limitations of in vivo NIR spectroscopy and highlight the impact of these capabilities and limitations in selected areas where NIR spectroscopy is being used to address clinical problems. The optical properties of tissues are briefly reviewed, as are the instrumental methods available to the experimentalist. These properties and methods largely dictate the feasibility of an in vivo spectroscopic diagnostic approach and constrain the scope of problems that can be tackled using optical–NIR spectroscopy. Some of the more successful applications are described, including studies of tissue oxygenation, ischemia, and viability. A number of factors that can confound interpretation of in vivo NIR results are discussed. The number and magnitude of confounding influences that arise in in vivo spectroscopy can be daunting to the experimentalist and may represent the largest barrier in transforming in vivo spectroscopic measurements into clinically meaningful and reliable information. In vivo NIR spectroscopy abounds with opportunity and challenge.
Magnetic Resonance, General Medical
Authors: Winter Patrick , Bansal Navin 
Published: September 2006

AbstractNuclear magnetic resonance (NMR) is the basic physical phenomenon in which certain nuclei absorb and emit radiofrequency (RF) radiation while in the presence of a magnetic field. The noninvasive nature of NMR techniques, including magnetic resonance imaging (MRI) and magnetic resonance spectroscopy (MRS), has allowed explosive developments in biomedical applications since the late 1970s. MRI of protons is now a widely accepted clinical imaging technique, whereas MRS of various nuclei, including31P,1H,13C,23Na, and19F, can provide a vast amount of metabolic and physiological information. MRI provides significant advantages over many other imaging techniques in terms of resolution, contrast, and its noninvasive nature. Although not as common in clinical medicine, MRS also provides valuable metabolic information that cannot be obtained by other techniques. This article reviews the fundamentals of spatial encoding, contrast, artifacts, and applications of MRI as well as some recent advances in the field. Some applications of biomedical MRS of various nuclei are also discussed.
Infrared Spectroscopy in Microbiology
Authors: Naumann Dieter 
Published: September 2006

AbstractInfrared (IR) spectra of intact microbial cells are highly specific fingerprint‐like signatures which are used to differentiate, classify, and identify diverse microbial species and strains. Microbial IR spectra are also useful to (1) detect in situ intracellular compounds or structures such as inclusion bodies, storage materials, and endospores, (2) monitor and quantify metabolically released CO2in response to various different substrates, and (3) characterize growth‐dependent phenomena and cell–drug interactions. The characteristic information, useful for microbial characterizations, is generally distributed over the entire IR region of the electromagnetic spectrum, i.e. over the near‐infrared (NIR), mid‐infrared (MIR), and far‐infrared (FIR). The spectral traits can be systematically extracted from the typically broad and complex spectral contours applying resolution enhancement techniques, difference spectroscopy, and pattern recognition methods such as factor‐analysis and cluster‐analysis, and artificial neural networks (ANNs). Additional applications arise by means of a light microscope coupled to the IR spectrometer. IR spectra of microcolonies containing less than 103cells are obtained from colony replica by a stamping technique that transfers microcolonies growing on culture plates to a special IR‐sample holder. Using a computer‐controlledx,y‐stage together with mapping and video techniques, the fundamental tasks of microbiological analysis, namely detection, enumeration, and differentiation of microorganisms, are perspectively integrated in one single apparatus.
Mass Spectrometry in Structural Biology
Authors: Schiller Jürgen , Arnold Klaus 
Published: September 2006

AbstractMass spectrometric methods may serve as powerful analytical methods in life sciences and medicine. Mass spectrometry (MS) is comparable in sensitivity to techniques based on chromatography or electrophoresis but has superior resolution. Although there are a number of suitable ionization methods, allowing the analysis of biological molecules that are of high molecular weight and low volatility, there are mainly two “soft‐ionization” techniques that confer only a minimum of degradation of the analyte: MALDI (matrix‐assisted laser desorption/ionization) and ESI (electrospray ionization).The following report provides a short overview on the advantages and drawbacks of MALDI analysis of biological samples. Whereas most applications of MALDI are in the field of protein analysis, the analysis of carbohydrates and lipids will also be comprehensively discussed. It will be shown that MALDI is a useful tool especially in the field of lipid analysis, whereas with carbohydrate analysis a number of problems still have to be solved. MALDI is a rapid and very sensitive (from the low picomolar to the attomolar range) tool that tolerates high amounts of impurities (in contrast to ESI), which are typically present in biological samples. A further advantage is that mainly singly charged ions are formed; this enables MALDI to be applied even to the analysis of crude mixtures. In comparison with ESI, MALDI is more sensitive and detects compounds of higher molecular weights, whereas ESI provides better mass resolution. Therefore, the combination of both methods is, in many cases, the ideal solution for a number of analytical problems.
Single Biomolecule Detection and Characterization
Authors: Greulich Karl Otto 
Published: September 2006

Abstract
In order to detect and analyze single biomolecules, near‐field microscopes and conventional far‐field microscopes are used. Spectroscopic experiments are now possible to test predictions of quantum mechanics in a very direct way. With biological macromolecules, chemical reactions can be seen directly in the microscope. Mechanical properties of individual macromolecules can be measured with very high precision. This allows a very basic process of life, the generation of motion, to be understood in its finest details. Finally, single molecule experiments allow the DNA molecule to be studied in its full, practically unlimited individuality.
Voltammetry In Vivo for Chemical Analysis of the Living Brain
Authors: O'Neill Robert D. , Lowry John P. 
Published: September 2006

AbstractThe mammalian brain is the most complex structure known to science. Our behavior, feelings, thoughts, and maybe even consciousness itself, may be a reflection of the interplay of electrical and chemical signaling that create these states, and how the physical brain gives rise to the properties of mind remains a major unanswered question. It is clear, however, that many of the drugs used empirically in the treatment of neurological disorders, such as Parkinson's disease, schizophrenia and depression, as well as mind‐altering substances of abuse, have specific chemical actions on nerve cells in the brain, highlighting the importance of chemical signaling in the functioning of neural networks.A growing number of methodologies are being developed, including sampling, spectroscopic and electrochemical, to study neurochemical phenomena in the living brain. One such set of techniques focuses on the detection of substances released from nerve cells, using amperometric electrodes and voltammetry in vivo (VIV) techniques. By implanting a microvoltametric electrode in a specific brain region, applying a suitable potential profile and recording the resulting faradaic current, changes in the concentration of a variety of substances in the extracellular fluid (ECF) can be monitored with sub‐second time resolution over extended periods. This allows investigations of the functions and roles of specific neurochemicals in neuronal signaling, drug actions, and well‐defined behaviors. The main limitations associated with VIV is, on the one hand, the limited number of ECF species that are electroactive, and on the other, the fact that electroactive substances present tend to oxidize at similar potentials, interfering with each other's detection. These restrictions are being overcome by ongoing developments, including the design of biosensors to broaden the range of target analytes and permselective membranes to block interference.
Glycolipid Analysis
Authors: Morrison Ian M. 
Published: September 2006

Abstract

Glycolipids are conjugated macromolecules that have a carbohydrate (oligosaccharide) component covalently bound to a lipid (diacylglycerol, ceramide, sterol or polyprenol) component. They are present both in procaryotes and eucaryotes but the carbohydrate components, as well as the lipid components, vary considerably between different animal, plant and microbial cells. The biological specificity of a glycolipid is due mainly to the carbohydrate structure. The amphipathic nature of glycolipids means that a single extraction scheme is impractical for all the different molecular species while special techniques are required to differentiate between the neutral glycolipids and acidic glycolipids (gangliosides). Thin‐layer chromatography (TLC) and high‐performance liquid chromatography (HPLC) are the major purification methods. Chemical methods are used to determine the carbohydrate and lipid profiles as well as the linkage analysis of both types of components and are used in conjunction with gas chromatography (GC), HPLC and TLC, sometimes coupled with mass spectroscopy (MS). Enzymatic methods can be used to determine the linkage sequence and anomeric configurations of the oligosaccharide structures and the same parameters are being determined by immunological methods with increasing frequency. Enzymatic methods are also used to establish the linkage analysis of the fatty acid in the diacylglycerol species. However, various MS and both
1
H‐ and
13
C‐NMR (nuclear magnetic resonance) methods, but mostly the former, are now invariably used to confirm the full structural features of an unknown glycolipid. The type of MS method used, matrix‐assisted laser desorption/ionization (MALDI), fast atom bombardment (FAB) or tandem mass spectrometry (MS/MS) will depend on the type of glycolipid.
Monosaccharides and Sugar Alcohol Analysis
Authors: Sturgeon Robert J. 
Published: September 2006

AbstractCarbohydrates, including monosaccharides and sugar alcohols, are widely distributed in nature, being found in plants, animals and micro‐organisms. They occur free, or in glycosidic linkage as polysaccharides or glycoconjugates (glycoproteins and glycolipids). It is important that suitable and sensitive methods are available for the analysis of these sugars, as in many cases only very small (microgram) amounts of material may be available. Polysaccharides and glycoconjugates must first be depolymerized to produce the monosaccharides quantitatively. The total carbohydrate released in these reactions may be determined by spectrophotometric or enzymic procedures.Numerous separation and detection methods are available to measure the individual sugar components. Paper and thin‐layer chromatography were two of the earliest techniques available, giving mainly qualitative values for individual sugar components. Major advances were made first in gas–liquid chromatography (GLC) and then with various types of liquid chromatography (LC) in the separation of individual sugars.High‐performance liquid chromatography (HPLC) and capillary electrophoresis (CE) are now two of the most commonly used techniques in sugar chromatography. Highly sophisticated detection systems, such as mass spectrometry (MS) for gas–liquid chromatographic separations, and spectrophotometric, fluorometric and electrochemical detection systems for LC of carbohydrates with suitable chromophores or fluorophores have been developed.Carbohydrates have been derivatized for use either in precolumn or postcolumn chromatography, resulting in the detection limit in the most sensitive systems approaching yoctomole levels for individual sugars.
Proteoglycan and Acidic Polysaccharide Analysis
Authors: Lauder Robert M. 
Published: September 2006

AbstractThe isolation and analysis of proteoglycans (PGs) and the acidic polysaccharide glycosaminoglycan (GAG) chains attached to them is an area of increasing importance. PGs are a structurally diverse group of complex macromolecules comprising a core protein, varying in size from 11 to 400 kDa, to which are attached one or more GAG chains of the same or a different type. These chains carry a negative charge derived mainly from sulfate groups and are composed of a repeating disaccharide, a hexosamine and either a hexuronic acid or, in keratan sulfate (KS), galactose.
Capillary Electrophoresis in Detection of Chemicals Related to the Chemical Weapons Convention
Authors: Boulet Camille A. 
Published: September 2006

AbstractThis article describes the application of capillary electrophoresis (CE) to the analysis of compounds relevant to the Chemical Weapons Convention (CWC). CE is an analytical technique that employs narrow‐bore, fused‐silica capillaries to perform high‐efficiency separations of analytes based on their mobilities in an electric field. In CE, analytes are dissolved in a buffer solution and placed in a capillary to which an electric field is applied. The analytes then migrate at a rate determined by their charge and size and are detected as they migrate past a detector. CE can analyze a broad range of compounds and is particularly applicable to the analysis of water‐soluble degradation products of scheduled compounds under the CWC. Compounds typically analyzed by CE include the hydrolysis products of nerve agents such as the alkylphosphonates and hydrolytic or oxidative products of the sulfur mustards such as thiodiglycol. The alkyphosphonates require the use of indirect ultraviolet (UV) detection or other detection methods as they do not possess a suitable UV chromophore. Degradation products of the sulfur mustards have been analyzed by micellar electrokinetic chromatography (MEKC) and direct UV detection. The ability of CE to analyze anionic, cationic, zwitterionic, and neutral CWC‐related compounds, whether they be chemical warfare (CW) degradation products or scheduled starting materials, without the requirement for elaborate sample processing or labeling procedures, is an important demonstration of the utility of CE for the analysis of CWC‐related compounds. CE can be an important screening method for rapid sample processing and further analysis for unambiguous identification. The relative ease of analysis should also increase its utility in field and on‐site analysis where minimizing the logistic burden is attractive.