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Since 2020, synchrotron radiation facilities in several Asia-Pacific countries have been collaborating in a major project called "SYNAPSE"(Synchrotrons for Neuroscience: an Asia-Pacific Scientific Enterprise). They use x-ray imaging to attack in a coordinated fashion one of the major issues in modern science: the structure of animal and human brains, including neurons and connections. The objective is to develop Google-like maps also including detailed structural and functional information for selected regions of interest. The sheer mass of data needed for the objective poses huge problems for the acquisition, processing, storage and use of images. In order to complete the task within a reasonable time, the key element of the SYNAPSE strategy is the parallel and coordinated work of several facilities on the same specimens. This article reviews different aspects of the enterprise, including the foundations of synchrotron radiation, coherence and of its role in advanced imaging, electron accelerators, x-ray optics and detectors. This will provide the foundation for an extensive presentation of the different components of SYNAPSE, with an overview of results already obtained within the consortium.

Mapping the large neural networks of animal and human brains is a fundamental but so far elusive task, because of the massive amount of data and the consequent prohibitively long image taking and processing times. We developed an effective strategy called “AXON” (Accelerated X-ray Observation of Neurons) to solve this problem. AXON can achieve comprehensive whole-brain mapping within a reasonable time by combining fast image taking and processing, plus two other critical performances: three-dimensional (3D) imaging with high and isotropic spatial resolution, and multi-scale resolution. We successfully tested this strategy with coordinated experiments at four synchrotron facilities in Japan, Taiwan, Singapore and Korea on two animal models, Drosophila and mouse. Its performances notably allowed full 3D mapping of the Drosophila brain in a few days. With reasonable improvements, AXON can deliver full mapping of large animal and human brains on a realistic time scale of a few years.

Determining the filtration function and biochemical status of kidney at the single glomerulus level remains hardly accessible, even from biopsies. Here, we provide evidence that IR spectro-microscopy is a suitable method to account for the filtration capacity of individual glomeruli along with related physio-pathological condition. A ∼4 μm voxel resolution 3D IR image reconstruction is built from consecutive tissue sections, thus, providing a 3D IR spectrum matrix of an individual glomerulus. The filtration capacity of glomeruli was quantitatively determined after BaSO4 perfusion, and additional chemical data could be used to determined oxidative stress effects and fibrosis, thus, combining functional and biochemical information from the same 3D IR spectrum matrix. This analytical approach was applied on mice with unilateral ureteral obstruction (UUO) inducing chronic kidney disease. Compared to the healthy condition, UUO induced a significant drop in glomeruli filtration capacity (−17 ± 8% at day 4 and −...

Here, we introduce a unique high-throughput infrared (IR) microscopy method that combines automated image correction and subsequent spectral data analysis for 3D-IR image reconstruction., Three-dimensional (3D) histology is the next frontier for modern anatomo-pathology. Characterizing abnormal parameters in a tissue is essential to understand the rationale of pathology development. However, there is no analytical technique, in vivo or histological, that is able to discover such abnormal features and provide a 3D distribution at microscopic resolution. Here, we introduce a unique high-throughput infrared (IR) microscopy method that combines automated image correction and subsequent spectral data analysis for 3D-IR image reconstruction. We performed spectral analysis of a complete organ for a small animal model, a mouse brain with an implanted glioma tumor. The 3D-IR image is reconstructed from 370 consecutive tissue sections and corrected using the X-ray tomogram of the organ for an accurate quantitative analysis of the chemical content. A 3D matrix of 89 × 106 IR spectra is generated, allowing us to separate the tumor mass from healthy brain tissues based on various anatomical, chemical, and metabolic parameters. We demonstrate that quantitative metabolic parameters can be extracted from the IR spectra for the characterization of the brain vs. tumor metabolism (assessing the Warburg effect in tumors). Our method can be further exploited by searching for the whole spectral profile, discriminating tumor vs. healthy tissue in a non-supervised manner, which we call ‘spectromics’.

IR microscopy was first conceptualized in 1949 and the first commercial system was launched 1983. With the appearance of FPA detectors in the 90's, FTIR microscopy became a technique of choice for histology. Two decades later, the release of QCLs working in the mid-IR range refuels this promise by accelerating tremendously the acquisition of IR images for large tissue areas with high-quality spectra for chemical mapping of parameters of interest. The new QCL-IR imaging system allows a 150× faster spectral data acquisition at equivalent S/N level. The quality of spectral data is comparable while applying spectral curve-fitting treatments, thus showing that laser sources offer reliable signal over a large spectral range. If QCL-IR imaging system seem to offer the opportunity to develop routines for anatomo-pathology, several technological challenges stand in front of us to reach this goal to define the specs of an IR microscope dedicated to hospital.

Analytical techniques allowed describing the morphology of fossils, up the 3D level, and more recently, molecular remains are also characterized to understand evolutionary aspects of disappeared species. The preservation of original organic components in fossils is controversial, but elucidating evolutionary processes and phylogenetic relationships is invaluable. Infrared (IR) microscopy is one of the most interesting analytical technique, due to its non-destructive utilization and its sensitivity for extracting most of the inorganic and organic information in fossils. However, utilization of IR microscopy has rapidly raised controversies in paleontology, essentially because the interpretation of spectral data remains limited to experienced spectroscopists and also due to the nature of fossilized tissues, becoming mostly inorganic after the mineralization process. This review discusses the most important discoveries made by the use of IR microscopy for the analysis of fossils and provides a comprehensive IR bands database for interpreting fossil inorganic and organic contents.

This work explores the potential of Fourier transform infrared (FTIR) spectroscopic imaging at the single-cell level combined with partial least squares (PLS) regression to investigate the cell’s response to drug/gold nanoparticles (AuNPs) conjugates. In a broader context, this study provides not only the effective differentiation between non-tumorigenic, mildly malignant and malignant cells, but above all proposes a novel approach to define the sensitivity of cancer cells to drugs. AuNPs can be widely and effectively used in biosensing and bioimaging applications. Three human breast cell lines, i.e. MCF10A (non-tumorigenic), MCF7 (metastatic, pleural effusion, mildly malignant) and MDA-MB-231 (metastatic, pleural effusion, malignant) have been exposed to different concentration of AuNPs (15 mg/L and 10 mg/L) and AuNPs/α-methyl-DL-tryptophan conjugates conjugates (10 mg/L NPs @ 3.75 × 10−6 M and 10 mg/L NPs @ 3.75 × 10−5 M). It is implied that the class values predicted by the PLS regression model indicate a very good separation between non-tumorigenic, mildly malignant and malignant cells. Furthermore, the FTIR-PLS approach shows that bands responsible for the segregation between the control cells and the cells treated with drug/AuNPs conjugate result from the changes in RNA/DNA, lipids and amide I and II vibrations. Drug/AuNPs conjugate affects the nucleic acids in all of the studied cell types. The performed analysis suggests that MCF-7 cell line is particularly sensitive to the drug treatment, which result in the drug interacting with nucleic acids and DNA conformational changes.

Mineralized bone forms when collagen-containing osteoid accrues mineral crystals. This is initiated rapidly (primary mineralization), and continues slowly (secondary mineralization) until bone is remodeled. The interconnected osteocyte network within the bone matrix differentiates from bone-forming osteoblasts; although osteoblast differentiation requires EphrinB2, osteocytes retain its expression. Here we report brittle bones in mice with osteocyte-targeted EphrinB2 deletion. This is not caused by low bone mass, but by defective bone material. While osteoid mineralization is initiated at normal rate, mineral accrual is accelerated, indicating that EphrinB2 in osteocytes limits mineral accumulation. No known regulators of mineralization are modified in the brittle cortical bone but a cluster of autophagy-associated genes are dysregulated. EphrinB2-deficient osteocytes displayed more autophagosomes in vivo and in vitro, and EphrinB2-Fc treatment suppresses autophagy in a RhoA-ROCK dependent manner. We conclude that secondary mineralization involves EphrinB2-RhoA-limited autophagy in osteocytes, and disruption leads to a bone fragility independent of bone mass., Osteoblasts mediate bone formation, and their differentiation requires expression of EphrinB2. Here, the authors show that EphrinB2 is also expressed by osteocytes, and that its genetic ablation in mice is associated with altered autophagy, elevated mineralization and brittle bone.

FTIR spectroscopy is used to identify poly-L-lysin fatty-acyl-chain (PLL-FAC) conjugates based on structural differences found between FAC species. Twenty-one PLL-FAC models were used, from C8 to C24, and with up to 5 unsaturation levels (C20:5). Curve fitting of the 3050-2800 cm(-1) spectral interval permitted extraction of IR bands belonging to the stretching vibration modes of methyl, methylene, and alkene groups. Based on molecular structure models in 3D, the number and position of methyl bands could be set according to chain length and unsaturation level. Band positions for ν-(C = C

Mid-infrared (IR), Raman, and X-ray fluorescence (XRF) spectroscopy methods, as well as mass spectrometry (MS), can be used for 3D chemical imaging. These techniques offer an invaluable opportunity to access chemical features of biological samples in a nonsupervised way. The global chemical information they provide enables the exploitation of a large array of chemical species or parameters, so-called 'spectromics'. Extracting chemical data from spectra is critical for the high-quality chemical analysis of biosamples. Furthermore, these are the only currently available techniques that can quantitatively analyze tissue content (e.g., molecular concentrations) and substructures (e.g., cells or blood vessels). The development of chemical-derived biological metadata appears to be a new way to exploit spectral information with machine learning algorithms.

The work presents a detailed analysis of adsorption geometry of nocodazole, an antineoplastic agent, deposited onto gold nanoparticle surface. This type of study is fundamental because of improving drugs delivery specifically to cancer cells. Simultaneously, it will revolutionize oncology, dramatically improving the effect of drugs while reducing or even eliminating adverse side effects for the patient. The analytical means are now mature to study very precisely the solid-liquid interactions that will foreshadow the development of new anti-cancer therapies. This research demonstrates the feasibility of surface-enhanced infrared absorption spectroscopy (SEIRA), surface-enhanced Raman spectroscopy (SERS) and polarization-modulated surface-enhanced infrared absorption nanospectroscopy (PM-SEIRA) to study adsorption phenomenon of a molecule at the solid/liquid interface. A novel approach combining the classical infrared spectroscopy (IR) with atomic force microscopy (AFM) is employed to more comprehensively describe the behavior of the drug adsorbed on metal surface at the nanoscale level. The performed analysis enabled to track subtle changes in nocodazole bonds arrangement upon adsorption. The observed changes provide evidence for strong interaction between the electron-rich thiophene ring and metal surface. It can also be inferred that charge-transfer mechanism contributes considerably to the SERS signal amplification.

Evidence has recently emerged that solid and diffuse tumors produce a specific extracellular matrix (ECM) for division and diffusion, also developing a specific interface with microvasculature. This ECM is mainly composed of collagens and their scaffolding appears to drive tumor growth. Although collagens are not easily analyzable by UV-fluorescence means, FTIR imaging has appeared as a valuable tool to characterize collagen contents in tissues, specially the brain, where ECM is normally devoid of collagen proteins. Here, we used FTIR imaging to characterize collagen content changes in growing glioma tumors. We could determine that C6-derived solid tumors presented high content of triple helix after 8–11 days of growth (typical of collagen fibrils formation; 8/8 tumor samples; 91 % of total variance), and further turned to larger α-helix (days 12–15; 9/10 of tumors; 94 % of variance) and β-turns (day 18–21; 7/8 tumors; 97 % of variance) contents, which suggest the incorporation of non-fibrillar collagen types in ECM, a sign of more and more organized collagen scaffold along tumor progression. The growth of tumors was also associated to the level of collagen produced (P

An original synthesis method based on X-ray irradiation produced gold nanoparticles (AuNPs) with two important properties for biomedical research: intense visible photoluminescence and very high accumulation in cancer cells. The nanoparticles, coated with MUA (11-mercaptoundecanoid acid), are very small (1.4 nm diameter); the above two properties are not present for even slightly larger sizes. The small MUA-AuNPs are non-cytotoxic (except for very high concentrations) and do not interfere with cancer cell proliferation. Multimodality imaging using visible light fluorescence and X-ray microscopy is demonstrated by tracing the nanoparticle-loaded tumor cells. (C) 2012 Elsevier Inc. All rights reserved.

Currently, only mass-spectrometry (MS) microscopy brings a quantitative analysis of chemical contents of tissue samples in 3D. Here, the reconstruction of a 3D quantitative chemical images of a biological tissue by FTIR spectro-microscopy is reported. An automated curve-fitting method is developed to extract all intense absorption bands constituting IR spectra. This innovation benefits from three critical features: (1) the correction of raw IR spectra to make them quantitatively comparable; (2) the automated and iterative data treatment allowing to transfer the IR-absorption spectrum into a IR-band spectrum; (3) the reconstruction of an 3D IR-band matrix (x, y, z for voxel position and a 4th dimension with all IR-band parameters). Spectromics, which is a new method for exploiting spectral data for tissue metadata reconstruction, is proposed to further translate the related chemical information in 3D, as biochemical and anatomical tissue parameters. An example is given with oxidative stress distribution and the reconstruction of blood vessels in tissues. The requirements of IR microscopy instrumentation to propose 3D digital histology as a clinical routine technology is briefly discussed.

Extremely brilliant infrared (IR) beams provided by synchrotron radiation sources are now routinely used in many facilities with available commercial spectrometers coupled to IR microscopes. Using these intense non-thermal sources, a brilliance two or three order of magnitude higher than a conventional source is achievable through small pinholes (

We demonstrate that, with appropriate staining, high-resolution X-ray microscopy can image complicated tissue structures—cerebellum and liver—and resolve large or small amounts of Au nanoparticles in these tissues. Specifically, images of tumor tissue reveal high concentrations of accumulated Au nanoparticles. PEG (poly(ethylene glycol)) coating is quite effective in enhancing this accumulation and significantly modifies the mechanism of uptake by reticuloendothelial system (RES) organs. Refereed/Peer-reviewed

Fourier transform infrared (FTIR) imaging has been used as a molecular histopathology tool on brain tissue sections after intracranial implantation and development of glioma tumors. Healthy brain tissue (contralateral lobe) as well as solid and diffuse tumor tissues were compared for their collagen contents. IR spectra were extracted from IR images for determining the secondary structure of protein contents and compared to pure product spectra of collagens (types I, III, IV, V, and VI). Multivariate statistical analyses of variance and correspondence factorial analysis were performed to differentiate healthy and tumor brain tissues as well as their classification according to their secondary structure profiles. Secondary structure profiles revealed that no collagen was present in healthy tissues; they are also significantly different from solid and diffuse tumors (p

FTIR microscopy with a focal plane array (FPA) of detectors enables routine chemical imaging on individual cells in only a few minutes. The brilliance of synchrotron radiation (SR) IR sources may enhance the signal obtained from such small biosamples containing small amounts of organic matter. We investigated individual cells obtained from a cell culture specifically developed for transmission FTIR imaging using either a Globar or an SR source coupled to the same instrumentation. SR-IR source focussing was optimized to control the energy distribution on the FPA of detectors. Here we show that accessing the IR absorption distribution from all the organic contents of cells at 1 x 1 microm pixel resolution was possible only with high circulating current (or = 1.2 A) illuminating a limited number of the FPA's detectors to increase the signal-to-noise ratio of IR images. Finally, a high-current SR ring is mandatory for collecting FTIR images of biosamples with a high contrast in minutes.

Fourier transform infrared imaging instrumentation has come of age for the rapid acquisition of biosample IR images, and thus now allows developing analytical methods based upon the molecular information of samples contents. For the biomedicine field, Fourier transform infrared imaging should be able to play a role in the molecular characterization of cells and tissues where no other analytical method provides quantitative information. Now, a compromise may be obtained between an acceptable acquisition time of IR images, which should never exceed a few tens of minutes, and the necessary spatial resolution (down to the diffraction limit, although limited for biology), spectral resolution (2 to 8 cm−1 for biosample analyses), and signal-to-noise ratio level, to provide a diagnostic answer to clinicians during the surgery time. Here, we will discuss the potential of Fourier transform infrared imaging in face to major pathologies (myopathies, brain tumors, metabolic diseases) for which current imaging methods remain unable to provide sufficient information for a precise diagnosis. Quantitative molecular information may be extracted from infrared images of samples as soon as samples volume/thickness is controlled as well as absorption and absorptivity of the molecules to analyze may be isolated from other absorbing compounds. In this context, metabolic parameters appear as the main targets for providing critical information about the physiological status of a biosample due to their characteristic infrared spectra. As examples, it will be shown how to isolate and quantify glucose, lactic-acid, urea, etc. absorptions from complex biosample infrared images.

The study investigated blood markers allowing discriminating physiological responses to on-water rowing races, notably regarding training volume of athletes and race duration. College (COL) and national (NAT) rowers performed a 1000- or 2000-m race. Capillary blood samples obtained before and post-race allowed an analysis of a wide range of serum parameters. COL rowers had a lower rowing experience and training volume than NAT. Races induced a higher lactate concentration increase in NAT compared to COL (10.45 ± 0.45 vs 13.05 ± 0.60; p ¼ 0.001). Race distance (2000 vs. 1000 m) induced a higher increase in fatty acids (0.81 ± 0.31 vs +0.67 ± 0. 41; p ¼ 0.05) and triglycerides concentration in NAT (0.33 ± 0.07 vs 0.15 ± 0.09; p ¼ 0.01), but remained comparable between NAT and COL for the 1000-m races. Amino acids concentrations increased in NAT (0.19 ± 0.03, p ¼ 0.01), but urea concentration increased only for NAT rowers having performed the 2000-m race (0.72 ± 0.22, p ¼ 0.05). Transferrin concentration decreased after the 2000-m race (-0.60 ± 0.25, p ¼ 0.05), and concentration changes of haptoglobin differed between NAT2000 (tendency to be reduced) and COL (tendency to by enhanced) (p ¼ 0.05). Our results confirmed that the training level in rowing is associated with higher glycolysis utilization during maximal 1000- and 2000-m exercise and no difference for similarly trained subjects at these two distances. Our study also demonstrated that a 2000-m race could initiate fatty and amino-acid metabolisms in highly trained subjects. Therefore, these changes in blood parameter responses to a characteristic rowing exercise highlighted the importance of monitoring the physiological effects of training in sporting conditions and according to individual characteristics. Key pointsRowing races despite their short duration could initiate fatty and amino-acids metabolisms.Effects of maximal exercise on metabolic blood parameters depend on individual capabilities, suggesting that the effects of exercise or training on a given blood parameter may be monitored relatively to individual maximal concentrations rather than by inter-individual comparison.High training level may lead to marked disruption of homeostasis which could be easily reversed by high recovery capabilities.

Thrombin inhibition protects against liver fibrosis. However, it is not known whether the thrombin profibrogenic effect is due to effects on blood coagulation or to signaling via protease-activated receptors (PARs). We took advantage of the lack of blood coagulation defects in PAR-1-knockout mice. Acute carbon tetrachloride (CCl4) toxicity was similar in wild-type (WT), PAR-1−/−, and PAR-1+/−mice as judged by aminotransferase levels, area of liver necrosis, and liver peroxidation measured by Fourier-transformed infrared spectroscopy. Fifteen mice/group received CCl4or its solvent for 6 wk (300 μl/kg, 3 times a week). Fibrosis area was increased 10-fold by CCl4treatment in WT mice. PAR-1 deficiency protected against fibrosis, with 36% and 56% decrease in PAR-1+/−and PAR-1−/−mice, respectively ( P < 0.001). Similar results were obtained for area of activated fibrogenic cells (64% and 79% decrease in PAR-1+/−and PAR-1−/−mice, respectively, P < 0.001). These findings were corroborated by measurements of type I collagen, matrix metalloproteinase-2, and PDGF-β receptor mRNA levels. There was also a significant decrease in T lymphocyte infiltration in PAR-1-deficient mice. Altogether, these results suggest that thrombin profibrogenic effects are independent of effects on blood coagulation and are instead due to direct effects on fibrogenic cells and possibly on T lymphocytes.

Fourier-transform infrared (FT-IR) spectral imaging was used for analyzing biochemical changes in tumor cells. Metabolic parameters of human lung A549/8 adenocarcinoma and U87 glioma cells were compared under stress conditions in culture along with tumor progression after cell implantation onto the chick embryo chorio-allantoic membrane. In cell culture, glucose consumption and lactic acid release were higher in U87 cells. A549/8 cells were less sensitive to oxidative stress as observed through changes in fatty acyl chains. In vivo biochemical mapping of highly (U87) vs. poorly (A549/8) angiogenic tumors provided results comparable to culture models. Therefore, FT-IR imaging allows detecting subtle chemical changes in tumors, which might be useful for diagnosis.

Tumor ischemia participates in angiogenesis and cancer progression through cellular responses to hypoxia and nutrient deprivation. However, the contribution of amino acids limitation to this process remains poorly understood. Using serum-free cell culture conditions, we tested the impact of L-glutamine deprivation on metabolic and angiogenic responses in A549/8 carcinoma cells. In these cells, lowering glutamine concentration modified the cell cycle distribution and significantly induced apoptosis/necrosis. Although glutamine deprivation led to a HIF-independent increase in VEGF-A mRNA, the corresponding protein level remained low and correlated with the inhibition of protein synthesis and activation of the GCN2/eIF2alpha pathway. Limitation of glutamine availability also hampers hypoxia- and hypoglycemia-induced VEGF-A protein upregulation. Thus, glutamine deprivation may have no direct effect on VEGF-dependent angiogenesis, compared to hypoxia or to glucose deprivation, and may instead be detrimental to cancer progression by antagonizing ischemia-induced stresses.

In search of specific label-free biomarkers for differentiation of two oral lesions, namely oral leukoplakia (OLK) and oral squamous-cell carcinoma (OSCC), Fourier-transform infrared (FTIR) spectroscopy was performed on paraffin-embedded tissue sections from 47 human subjects (eight normal (NOM), 16 OLK, and 23 OSCC). Difference between mean spectra (DBMS), Mann-Whitney's U test, and forward feature selection (FFS) techniques were used for optimising spectral-marker selection. Classification of diseases was performed with linear and quadratic support vector machine (SVM) at 10-fold cross-validation, using different combinations of spectral features. It was observed that six features obtained through FFS enabled differentiation of NOM and OSCC tissue (1782, 1713, 1665, 1545, 1409, and 1161 cm(-1)) and were most significant, able to classify OLK and OSCC with 81.3 % sensitivity, 95.7 % specificity, and 89.7 % overall accuracy. The 43 spectral markers extracted through Mann-Whitney's U Test were the least significant when quadratic SVM was used. Considering the high sensitivity and specificity of the FFS technique, extracting only six spectral biomarkers was thus most useful for diagnosis of OLK and OSCC, and to overcome inter and intra-observer variability experienced in diagnostic best-practice histopathological procedure. By considering the biochemical assignment of these six spectral signatures, this work also revealed altered glycogen and keratin content in histological sections which could able to discriminate OLK and OSCC. The method was validated through spectral selection by the DBMS technique. Thus this method has potential for diagnostic cost minimisation for oral lesions by label-free biomarker identification.

We tested the hypothesis that endurance training may reduce exercise oxidative stress damage on erythrocytes.Fifteen subjects performed a standardized endurance exercise at 75% of maximal oxygen consumption weekly during a 19-week training period. Blood samples taken before and after exercise were analyzed by Fourier transform-infrared (FT-IR) spectrometry to determine exercise-induced change in plasma concentrations and erythrocyte IR absorptions.Training first induced a stabilization of plasma concentration changes during exercise (unchanged for glucose, increased for lactate, triglycerides, glycerol, and fatty acids), whereas erythrocyte phospholipid alterations remained elevated (p0.05). Further, training reduced the exercise-induced erythrocyte lactate content increase (nuC-O; p0.05) and phospholipid alterations (nuC-H(n) and nuP=O; p0.05) during exercise. These changes paralleled the decrease of exercise-induced hemoconcentration (p0.05) and plasma lactate increase (p0.05).These correlated changes between plasma and erythrocyte parameters suggest that endurance training reduces erythrocyte susceptibility to oxidative stress.

This study was designed to describe changes in plasma fatty acyl moieties during a 2-h endurance exercise. Sixteen endurance-trained subjects cycled 2 h at 55% of maximal power output and capillary blood was sampled every 15 min. Fourier-transform infrared (FT-IR) spectrometry was used to determine correlated changes between plasma fatty acyl moieties (FAM) structural characteristics and metabolic parameters (oxygen consumption, respiratory exchange ratio, glucose, lactate, TG, glycerol, and albumin). Opposite changes were found between carbohydrate and fatty acid metabolism during the second hour of exercise, i.e., a decrease of glucose and lactate concentrations while albumin, FAM, and TG increased. For fatty acid metabolism, FAM and TG did not showed the same pattern of changes at the end of exercise, i.e., TG remained constant after 90 min while FAM continued to increase. This late FAM concentration increase was correlated to the changes in albumin concentration and the nu C=C-H/nu(as) CH3 and nu(as) CH2/nu(as) CH3 ratios. These ratios clearly showed that FAM unsaturation increased while chain length decreased. It was hypothesized that PUFA from TG adipose lipolysis ketone bodies (beta-hydroxybutyric acid) from liver may have been released in higher amounts as glycogen stores became depleted after 90 min of exercise.

Background We tested the hypothesis that endurance over-training could alter the favorable effects of well-tolerated training on lipid profile. Methods At weeks 1, 6, 15, 26, 36, and 47 of the training program, blood was drawn to test lipid profile of 20 endurance-trained rowers. Diet and caloric intake were controlled. Results Over-training was diagnosed in five subjects (loss of performance, asthenia, sleep disturbance…) at week 15 and lipid profile of well-trained and over-trained subjects were compared. Training improved cholesterolemic profile and lowered insulin resistance (HOMA-IR: −39 ± 9%; p = 0.02), and triglycerides concentration (−30 ± 6%; p = 0.05) in rowers who did not change to demonstrate over-training. Plasma LPL (+29 ± 11%; p = 0.01) and hepatic lipase (+5 ± 3%; p = 0.01) activities increased in this group suggesting higher TG utilization and turnover. After week 15 and regarding the well-trained condition for the five over-trained subjects, VLDL-TG (−13 ± 7 %; p = 0.03) and Apo-C 3 (−31 ± 13%; p = 0.01) concentrations decreased, while insulin resistance (+17 ± 7%; p = 0.03) and glycerol concentration (+17 ± 3%; p = 0.01) increased and hepatic lipase activity decreased (−14 ± 4%; p = 0.01). Conclusion Over-training was accompanied by alterations in the lipid profile, which appeared to be the consequence of over-training.

The objective of this study was to describe long-term detraining effects on lipid profile in previously highly endurance-trained athletes. The study design was longitudinal, with a 2-yr follow-up study of changes in lipid profile during hard training and detraining. Ten subjects trained for 2 yr (22 h/wk; two 47-wk training periods with a 5-wk recovery period), and the 10 others stopped training after wk 47. Main blood lipid profile parameters, energy intake, and body composition were measured at baseline (wk 1) and at wk 24, 47, 52, 76, and 99. Although food caloric intake was reduced (2411 +/- 256 vs. 5697 +/- 455 kcal/d, detraining vs. training), detraining induced a decrease in high density lipoprotein cholesterol and increases in fat mass (by 6.5 +/- 1.1 kg), body mass index, leptin, low density lipoprotein cholesterol, low density lipoprotein/high density lipoprotein ratio, and apolipoprotein B, although insulin resistance (determined by homeostasis model assessment) stabilization had previously occurred. Further disorders appeared in triglycerides (TG) metabolism during detraining, with a persistent increase in TG (from 1.0 +/- 0.3 to 1.4 +/- 0.3 mmol/liter), whereas glycerol decreased (from 88 +/- 9 to 73 +/- 8 micromol/liter), and very low density lipoprotein-TG, chylomicrons, and apolipoprotein C(3) remained stable. Plasma lipoprotein lipase activity decreased whereas hepatic lipase activity remained stable. As well as a rapid loss of endurance-training benefits for the cholesterolemic profile, detraining also induced disorders in TG metabolism, possibly as a result of the elevated TG turnover acquired with long-term hard training.

For determining exercise-induced changes in plasma molecular species, we investigated the feasibility of using two-dimensional correlation spectra (2D-COS) on 21 series of plasma samples obtained from progressive exercise tests. Intensities of 2D synchronous and asynchronous correlation peaks were compared to concentration evolutions of glucose, lactate, triglycerides (TG), glycerol, fatty acyl moieties, amino acids, proteins, and albumin [determined from plasma Fourier transform infrared (FTIR) spectra] and to performance and training levels of athletes. Synchronous 2D-COS allowed us to determine the linear relationship between protein and fatty acid concentration evolutions as exercise intensity increased (ν1 − ν2; 2959 vs 1656 and 1543 cm−1). Asynchronous 2D-COS allowed differentiation of fibrinolysis level in subjects during intense exercise, as well as parameters of fatty acid metabolism specifically related either to performance or to training levels. Furthermore, unexpected correlated evolutions of molecular species were highlighted by this method, showing that 2D spectrometry may also be used for experimental investigations on human physiology. This study has demonstrated that 2D-COS may be used for the treatment of complex biological samples, such as plasma. © 2004 Wiley Periodicals, Inc. Biopolymers, 2004

This study was designed to evaluate changes in erythrocyte contents during endurance moderate intensity exercise, a model of physiological oxidative stress. 16 endurance-trained subjects cycled 2 h at 55% of maximal aerobic capacity and blood was collected every 15 min. Transmission FT-IR spectrometry was used to analyze separately plasma and erythrocyte content changes during oxidative stress. Erythrocyte FT-IR spectra were corrected for hemoconcentration (Hc) before spectral areas integration of main IR absorbances belonging to phospholipids [nu(as)(CH(3)), [nu(as)(CH(2)), and nu(P=O)], proteins [nu(C=O) and delta(N-H)], and lactate [nu(C-O)] were used to determine erythrocyte content changes. Changes in nu(as)(CH(2)) and nu(P=O) absorbances while nu(as)(CH(3)) remained stable showed the magnitude of free radical attacks on phospholipids bilayer. Decrease in nu(C=O) and delta(N-H) absorbances while plasma and intracellular lactate, O(2) consumption, and Hc rose were linked to hemoglobin, and possibly spectrin, denaturation. Finally, the synergistic changes found between physiological, plasmatic and erythrocyte parameters showed that FT-IR spectrometry was a sufficiently accurate and sensitive method to determine acute changes in erythrocytes during moderate, physiological, oxidative stress.

The purpose of this study was to apply two-dimensional (2D) correlation Fourier-transform infrared (FT-IR) spectrometry to sets of plasma spectra obtained during a physical exercise. Seven male swimmers performed a maximal 400 m test in a 25 m swimming pool. On three other tests, the first 100, 200, and 300 m were swam on the same velocity basis of the 400 m test. 2D correlation spectra were obtained from blood samples taken at rest and after the 100, 200, 300, and 400 m tests. Exercise-induced changes in plasma concentrations and plasma spectra absorptions (νasCH3, νasCH2, νCO, νN–H, δNH2, and νCOO−) were compared to Z-values (correlation peak intensities) found on 2D correlation spectra. During exercise, linear changes were found for glucose, albumin (increases), triglycerides, and fatty acyl moieties (decreases), while lactate and amino-acids increased exponentially, and glycerol increased after 200 m (delayed). Asynchronous 2D-COS highlighted qualitative changes in fatty acid metabolism specifically related to performance (fatty acid selectivity), and allowed to distinguish the origin of urea formation between protein catabolism and amino-acid metabolism. This study has provided further evidence that 2D-FT-IR spectrometry may be used on complex biological samples, such as plasma.

Here, we review recent methodological developments for plasma analysis by Fourier-transform infrared (FT-IR) spectrometry to provide both a high sensitivity and a global overview of its biomolecular contents along with the variations of these ones. Transmittance FT-IR spectrometry has been used to analyze plasma micro samples (50 μl) using an iterative process. Results in accordance with clinical data were obtained from a single FT-IR spectrum for the following biomolecules: amino acids, fatty acids, albumin, glucose, fibrinogen, lactate, triglycerides, glycerol, urea, α 1 -antitrypsin, α 2 -macroglobulin, transferin, Apo-A 1 , Apo-B, Apo-C 3 , IgA, IgD, IgG 1 , IgG 2 , IgG 3 , IgG 4 , IgM, haptoglobin, α 1 -acid glycoprotein, cholesterol, and cholesterol esters. Therefore, as only micro samples are necessary, high frequency blood analysis become available. We also present a novel application of this method for the monitoring of inflammatory processes related to given metabolic stresses in rugby players. We show that an FT-IR spectrum constitutes a “metabolic photography” of the subject, allowing classification between metabolic groups (pathologic or others). It was used on difference spectra in order to raise “signal-to-noise” ratio by elimination of the unvarying spectral contribution. Among others, it allowed to uncover overtraining in high-level sportsmen several weeks before any physiologic or clinical symptom occurred.

Our purpose was to determine the plasma-volume (PV) change induced by a physical stress independent of the metabolic events that may interfere with physiological fluid shifts in to and out of the intravascular space. Our methods included using 178 exercise tests of varying duration and intensity for determination of PV change during exercise. Plasma Fourier transform infrared (FT-IR) spectra were used to compare hematocrit change to the total spectral area (4000–500 cm−1) and the protein and albumin concentration changes induced by exercise. Our results showed that exercise induced a raise in protein (+10.4 ± 3.1%) and albumin (+9.8 ± 3.3%) concentrations that significantly correlated with PV change (14.1 ± 5.2% of plasma volume; P = 0.05 with protein and albumin concentration changes). However, evolution of the total spectral area obtained from rest-plasma (524 ± 21 a.u.) and exercise-plasma (611 ± 26 a.u.; +14.1 ± 4.8%) FT-IR spectra showed a higher correlation level with PV change ( r = 0.98; P = 0.005; Sx/y = 1.26 a.u.). It is our conclusion that although exercise-induced changes in protein and albumin concentrations were found to correlate with PV change, the use of the total spectral area of the plasma FT-IR spectra allowed a more precise measurement of PV change.

Resume Objectif – L'objet de ce travail fut d'etudier les adaptations metaboliques de 7 nageuses et 8 nageurs en debut de saison d'entrainement. Methodes – Trois seances standardisees accompagnees, avant-apres, de micro prelevements sanguins analyses par spectrometrie infrarouge, furent realisees au cours des semaines 1, 3 et 5 de reprise d'entrainement. Resultats – La 1re semaine, la glycemie diminua plus chez les filles (– 1,101 mmol l–1) que chez les garcons (– 0,687 mmol l–1), alors que les triglycerides (TG) augmenterent chez les filles (0,184 mmol l–1) et diminuerent chez les garcons (– 0,094 mmol l–1). Ces derniers presenterent aussi une plus forte augmentation de l'uree (p Conclusions – Hormis la reaction immunitaire, a l'issue de cinq semaines d'entrainement, il semble que nageurs et nageuses atteignent les memes adaptations metaboliques apres avoir montre des reponses metaboliques provisoirement differentes entre eux.

We studied the effects of a twelve months endurance-training program on exercise-induced change in blood contents in thirteen rowers. A standardized testing-session (18 km rowing at 80 % of VO2max) was performed 19 times during the training program. Capillary blood samples were taken at rest and immediately post-exercise to analyse a wide range of serum concentrations. During exercise, glucose and lactate concentrations stabilized after only five training weeks and did not evolve from that point. Transport and hepatic protein concentrations increased with exercise up to the 15th week (p = 0.03), and remained stable from that point (p = 0.02). Evolution of exercise-induced change in alpha 1 -acid glycoprotein concentration revealed protein metabolism adaptations to training. Change in alpha 1 -acid glycoprotein concentrations were exactly opposite to that of urea and alpha 1 -antitrypsin (p = 0.01 and 0.002, respectively). Immunoglobulin concentrations exhibited important increases up to the 6th training week (p < 0.05), and a global stabilization was observed from that point. However, analysis of IgG subclasses highlighted significant changes that could not be found with the study of total IgG concentrations. Evolution of the exercise-induced change in Apo-A 1 /Apo-B concentrations ratio was also more informative about lipid metabolism than the Apo-A 1 and Apo-B concentrations taken individually. Indeed, evolution of metabolic changes during exercise should be carefully monitored during training to avoid interpretative errors on the training status of athlete.

Recent studies have shown that endurance overtraining could result from successive and cumulative alterations in metabolism, which become chronic during training. The onset of this process is a biochemical alteration in carbohydrate (saccharide) metabolism. During endurance exercises, the amount of saccharide chains from two blood glycoproteins (alpha(2)-macroglobulin and alpha(1)-acid glycoprotein) was found to have decreased, i.e. concentrations of these proteins remained unchanged but their quality changed. These saccharide chains were probably used for burning liver glycogen stores during exercise. This step was followed by alterations in lipid metabolism. The most relevant aspect of this step was that the mean chain length of blood fatty acids decreased, i.e. the same amount of fatty acids were found within the blood, but overtrained individuals presented shorter fatty acids than well-trained individuals. This suggests that alterations appeared in the liver synthesis of long-chain fatty acids or that higher peroxidation of blood lipoparticles occurred. For the final step of this overtraining process, it was found that these dysfunctions in carbohydrate/lipid metabolism led to the higher use of amino acids, which probably resulted from protein catabolism. The evolution of three protein concentrations (alpha(1)-acid glycoprotein, alpha(2)-macroglobulin and IgG(3)) correlated with this amino acid concentration increase, suggesting a specific catabolism of these proteins. At this time only, overtraining was clinically diagnosed through conventional symptoms. Therefore, this process described successive alterations in exercise metabolism that shifted from the main energetic stores of exercise (carbohydrates and lipids) towards molecular pools (proteins) normally not substantially used for the energetic supply of skeletal muscles. Now, a general biochemical model of the overtraining process may be proposed which includes most of the previously identified metabolic hypotheses.

Background Nanoparticles can be used for targeted drug delivery, in particular for brain cancer therapy. However, this requires a detailed analysis of nanoparticles from the associated microvasculature to the tumor, not easy because of the required high spatial resolution. The objective of this study is to demonstrate an experimental solution of this problem, based in vivo and post-mortem whole organ imaging plus nanoscale 3-dimensional (3D) X-ray microscopy. Results The use of gold nanoparticles (AuNPs) as contrast agents paved the way to a detailed high-resolution three dimensional (3D) X-ray and fluorescence imaging analysis of the relation between xenografted glioma cells and the tumor-induced angiogenic microvasculature. The images of the angiogenic microvessels revealed nanoparticle leakage. Complementary tests showed that after endocytotic internalization fluorescent AuNPs allow the visible-light detection of cells. Conclusions AuNP-loading of cells could be extended from the case presented here to other imaging techniques. In our study, they enabled us to (1) identify primary glioma cells at inoculation sites in mice brains; (2) follow the subsequent development of gliomas. (3) Detect the full details of the tumor-related microvasculature; (4) Finding leakage of AuNPs from the tumor-related vasculature, in contrast to no leakage from normal vasculature. Electronic supplementary material The online version of this article (doi:10.1186/s12951-015-0140-2) contains supplementary material, which is available to authorized users.

Global metabolic adaptations to physical conditioning were described in 15 subjects by FT-IR spectrometry as the method allowed determination of glucose (Glc), lactate (La), glycerol, triglycerides (TG), fatty acyl moieties (FAM), and total amino acids plasma concentrations. Subtraction of plasma FT-IR spectra obtained at resting state from the exercise spectra also allowed determination of the biomolecular response to exercise. On week 1, exercise induced a transient hypoglycemia, a lactatemia increase of 153%, a FAM depletion of 27%, and a TG concentration decrease of 28%. Protein contents increased by 2%, but these were partly catabolized for amino acid supply (+27%), suggesting an important metabolic stress during exercise. On week 3, exercise hypoglycemia had disappeared, lactate increase was diminished by 91%, TG contents were decreased by 14%, and proteins and amino acids exhibited higher absorption increases. On week 5, TG and FAM concentrations were markedly increased during exercise, protein absorption was still increased (+9%), but amino acid blood release was diminished by 81%. These results described positive adaptations to training. Furthermore, FAM concentration could be determined from plasma FT-IR spectra by using the 2996–2819 cm−1 spectral area [ νas(CH3), νas(CH2), νs(CH3), and νs(CH2) absorbance; 0.82 mMol·L−1, a.u. cm−1], as well as for amino acid concentration by using the ν(COO−) spectral area (1430–1360 cm−1; 0.062 g·L−1, a.u. × cm−1). FT-IR spectrometry was useful to determine simultaneously various plasma concentrations and most of the biomolecular changes through successive samples.

FT-IR spectrometry was used for plasma triglyceride and glycerol concentration measurements, based on their most characteristic IR absorbances within the 1200–800 cm−1interval. Plasma samples from 68 sportsmen were taken at rest and after an endurance exercise that induced important lipolysis. After subtraction of glucose and lactate absorbances from exercise plasma FT-IR spectra, triglyceride concentration was accurately determined using the spectral window centered at 1106 cm−1(0.86 ± 0.19 vs. 0.84 ± 0.17 mMol/L; r = 0.97, P < 0.01; SEP = 0.14 mMol/L). Total glycerol concentration (sum of glycerol and glyceryl residue concentrations) was determined using the spectral window centered at 926 cm−1, which was found common to triglycerides and glycerol (0.306 ± 0.057 vs. 0.326 ± 0.051 mMol/L; r = 0.98, P < 0.01; SEP = 0.02 mMol/L). Glycerol concentration could be determined using the spectral window centered at 852 cm−1(0.216 ± 0.039 vs. 0.231 ± 0.048 mMol/L; r = 0.95, P < 0.01; SEP = 0.03 mMol/L). However, weak glycerol concentration could be only indirectly determined by subtracting glyceryl residue concentration from total glycerol concentration that had been determined using the spectral window centered at 926 cm−1(0.191 ± 0.061 vs. 0.176 ± 0.051 mMol/L; r = 0.90, P < 0.05; SEP = 0.02 mMol/L). Indeed, FT-IR spectrometry appears to be an accurate method for multiple biomolecular concentration determination on plasma samples.

Blood chemical parameters were analyzed by Fourier-transform infrared spectrometry (notably for determining the concentrations of glucose, lactate, urea, glycerol, triglycerides, and proteins) in 14 top-class marathon runners (133.7±4.1 min at marathon, 10.1% difference between extremes) who performed a 10-km run at their individual marathon velocity. Marathon performance level was correlated to glycemia increase during exercise (9% difference between extremes; r=0.93; p

Top-level performances in endurance sports require several years of hard training loads. A major objective of this endurance training is to reach the most elevated metabolic adaptations the athlete will be able to support. As a consequence, overtraining is a recurrent problem that highly-trained athletes may experience during their career. Many studies have revealed that overtraining could be highlighted by various biochemical markers but a principal discrepancy in the diagnosis of overtraining stems from the fact that none of these markers may be considered as universal. In endurance sports, the metabolic aspects of training fatigue appear to be the most relevant parameters that may characterise overtraining when recovery is not sufficient, or when dietary habits do not allow an optimal replenishment of substrate stores. From the skeletal muscle functions to the overall energetic substrate availability during exercise, six metabolic schemes have been studied in relation to overtraining, each one related to a central parameter, i.e. carbohydrates, branched-chain amino acids, glutamine, polyunsaturated fatty acids, leptin, and proteins. We summarise the current knowledge on these metabolic hypotheses regarding the occurrence of overtraining in endurance sports.

The pathologic condition of a patient presenting a metabolic disease can change rapidly, and a variety of pathologic conditions are possible. Plasma Fourier-transform infrared (FT-IR) spectra were used to differentiate patients with type 1 diabetes, healthy subjects, and endurance-trained rowers. Analytic and classification methods that use the same plasma FT-IR spectra are described. Complete spectra (4000 to 500 cm(-1)) classifications led to a differentiation between most patients with type 1 diabetes and other subjects but not between control and trained subjects. Classification of defined absorption regions of spectra allowed different metabolic distinctions between populations. These were performed on the amide I and II absorption regions of proteins (1720 to 1480 cm(-1)); on the nu=CH, nu(as)CH(2), and nu(as)CH(3) absorption regions of lipids (3020 to 2880 cm(-1)); and on the nuC-O absorption region of saccharides (1300 to 900 cm(-1)). A classification that uses a combination of four absorption regions-nu=CH (3020 to 3000 cm(-1)), nu(as)CH(3) (3000 to 2950 cm(-1)), nuC-O (amide I: 1720 to 1600 cm(-1)), and nuC-O (carbonyle: 1300 to 900 cm(-1))-led to the formation of three exclusive clusters that comprised the defined populations. FT-IR spectroscopy is an exciting technique that allows a versatile approach to biologic samples from which analytic and statistical methods might be used for metabolic profile characterization and evaluation.

La biologie est un des champs majeurs de recherche parmi les sciences et techniques des activites physiques et sportives. De l’enfant au pratiquant de haut niveau, on y puise une meilleure comprehension de leur motricite et de leur performance physique. Nombreuses sont les techniques mises en œuvre au sein de ce champ disciplinaire pour mesurer et evaluer les differentes composantes biologiques susceptibles d’expliquer une partie de l’activite physique. Dans le domaine du sport, depuis l’exploration fonctionnelle des capacites physiologiques du sportif a l’analyse des processus biochimiques les plus fins du metabolisme energetique, de nombreuses interrogations ont pu trouver les reponses explicatives. L’objet de cet article est de tenter de dresser un bilan sur les dernieres evolutions des principales techniques d’analyse les plus couramment utilisees dans le domaine de la biologie du sport. De la seule determination de la lactatemie a la recherche des marqueurs biochimiques temoins de la fatigue ou du processus de surentrainement, des techniques enzymatiques aux methodes spectrales d’identification des metabolites, cette evolution vers la dimension moleculaire de la physiologie traduit bien la complexite qui est apparue dans les nouvelles questions posees par la biologie du sport.

Le present expose comprend deux parties. Chacune d’elles est presentee sous forme de questions auxquelles, a partir de donnees publiees, nous tentons d’apporter des reponses critiques et certaines reserves a des theories quelque fois trop hâtivement admises concernant les effets de l’acide lactique. La premiere partie est essentiellement consacree a l’etude de la production et du devenir du lactate au cours ou a l’issue de l’exercice. Elle devrait permettre de mieux fonder nos critiques : sur certains a priori concernant les effets du lactate, sur les concepts de « seuils anaerobies lactiques » (S.A.L.) et sur les theories qui les sous tendent. La seconde est beaucoup plus appliquee aux consequences supposees, mais non prouvees de l’accumulation lactique sur la fonction musculaire. Peut-on accepter encore aujourd’hui de soutenir que la glycolyse lactique a un mauvais rendement ? que l’accumulation lactique entraine fatigue, crampes et autres douleurs musculaires retardees ?

A longitudinal biological study of 20 elite rowers was performed using capillary blood (serum) FT-IR spectra to evaluate their training load adaptations and fatigue.Difference spectra (rest serum spectra subtracted to exercise serum spectra) were used to evaluate subjects' metabolic response to exercise. Spectra classifications were used for serum contents differentiation on the basis of biomolecular absorption.For two subjects, several metabolic differentiations were observed. These started with sugars metabolism on the fifth training week, followed successively by lipid metabolism and protein metabolism, when overtraining was clinically diagnosed. Several weeks further into the training program, the same onset of metabolic differentiations was observed for eight other subjects. When differentiations reached lipid metabolism, they were asked to reduce their training loads. Unlike the overtrained subjects, a rapid recovery was observed (3 vs 22 wk) and metabolism alterations disappeared.The fatigability limit in sportsmen seemed to be situated at a certain level of metabolic stress, beyond which a rapid overtraining process recover was no longer possible.