https://www.fertstert.org/article/S0015-0282(07)03049-X/pdf

Noninvasive metabolomic profiling of embryo culture media using Raman and near-infrared spectroscopy correlates with reproductive potential of embryos in women undergoing in vitro fertilization

Retrieval of chlorophyll concentration from leaf reflectance spectra using wavelet analysis.

Hydrophilic interaction liquid chromatography (HILIC), although not a new technique, has enjoyed a recent renaissance with the introduction of robust and reproducible stationary phases. It is consequently finding application in metabolomics studies, which have traditionally relied on the stability of reversed phases (RPs), since the biofluids analyzed are predominantly aqueous and thus contain many polar analytes. HILIC's retention of those polar compounds and use of solvents readily compatible with mass spectrometry have seen its increasing adoption in studies of complex aqueous metabolomes. This review describes the stationary phases and their features, surveys HILIC-LC-MS's role in metabolomics experiments, discusses approaches to data extraction and analysis including multivariate analysis, and reviews the literature on HILIC-MS applications in metabolomics.

Metabolomic applications of HILIC-LC-MS.

BACKGROUND: The morphology of an embryo has a limited predictive value for assessing viability and ongoing pregnancy, therefore new selection tools are needed to maintain success rates with single-embryo transfer (SET). In this study, we investigated if metabolomic profiling of biomarkers of embryo culture medium by near-infrared (NIR) spectroscopy has a correlation with ongoing pregnancy in SET. METHODS: A total of 333 patients scheduled for in vitro fertilization (IVF) with SET were included in the study. Embryos were selected for transfer by morphological criteria on Days 2 and 3 of in vitro culture, and left over culture media samples were analyzed by NIR spectroscopy. RESULTS: The NIR spectral analysis produced unique metabolomic profiles that correlated to an embryo's reproductive potential. Resulting relative viability scores between positive and negative pregnancy outcomes were statistically significant (P < 0.03). A logistic regression of factors correlated to pregnancy outcomes showed that maternal age, percent fragmentation and relative viability scores all demonstrated a relationship. The extent of the correlation was determined by accuracy computation, where the accuracy of assessing viable embryos on Day 3 by metabolomic profiling was 53.6% and the accuracy of the morphological selection was 38.5%. In addition, the positive predictive value of metabolomic profiling was 0.365 and the negative predictive value was 0.830. CONCLUSIONS: NIR metabolomic profiling of spent embryo culture media was able to distinguish viable embryos from non-viable embryos for reproduction.

Metabolomic profiling by near-infrared spectroscopy as a tool to assess embryo viability: a novel, non-invasive method for embryo selection

Noninvasive metabolomic profiling as an adjunct to morphology for noninvasive embryo assessment in women undergoing single embryo transfer.

Parsimonious calibration models for near-infrared spectroscopy using wavelets and scaling functions

The sections in this article are


Introduction
Light Propagation in Tissue
Tissue Properties
Models of Light Propagation in Turbid Media


Instrumentation
Light Sources
Continuous-Wavelength Light Sources
Discrete-Wavelength Light Sources


Wavelength Selection
Filters
Dispersive Elements
Interferometers


Detectors
SW-NIR
LW-NIR


Light Delivery and Collection
Direct Contact
Fiber Optic
Optical Relay Lens System




Respiratory Components
Hemoglobin
Myoglobin
Cytochrome C Oxidase
Glucose and Lactate


Structural Components
Water
Protein and Lipids
Temperature
pH


Conclusion

In Vivo Near-Infrared Spectrometry

Multiresolution analysis for quantification of optical properties in scattering media using pulsed photon time-of-flight measurements

La presente etude porte sur la quantification des proprietes optiques d'echantillons hautement diffusifs par analyse en transformee de Haar (TH) de la distribution des temps de vol de photons transmis. Des echantillons de composition connue (100 < μ s < 250 mm - 1 et 0 < μ a < 0.050 mm - 1 ), obtenus a partir de lait et d'un colorant hydrosoluble, ont ete analyses. Apres avoir calcule la TH des distributions temps-de-vol de photons, les combinaisons les plus parcimonieuses d'ondelettes pour estimer les proprietes optiques ont ete determinees. De plus, nous avons examine l'utilite d'un logarithme calcule soit avant ou apres la TH, ainsi qu'une correction des donnees pour la dispersion. Les resultats montrent que les estimations de dispersion necessitent un logarithme dans le pretraitement. Les coefficients de diffusion furent estimes avec un coefficient de variation (CV) de 2.9% et r2 = 0.99 en utilisant trois ondelettes modulees a moins de 0.8 GHz. Les determinations de l'absorption ont ete realisees avec un CV de 7.9% et r2 = 0.99 en se basant sur un logarithme avant la TH et sur la division des coefficients d'ondelettes par une valeur estimee de μ s . Alternativement, l'absorption peut etre estimee en utilisant un logarithme apres la TH avec une correction pour la dispersion, menant a un CV de 9.6% avec r 2 = 0.98. Cette derniere sequence de traitement de donnees se prete a etre executee directement dans un instrument en utilisant un reseau d'interrupteurs et de compteurs. Au total, trois interrupteurs modules a moins de 0.8 GHz pourraient etre suffisants pour estimer a la fois la dispersion et l'absorption. Les resultats presentes suggerent que les composantes electroniques haute vitesse des instruments habituellement utilises pour mesurer le temps de vol de photons pourraient etre remplacees, et qu'une partie de l'analyse des donnees pourrait etre câblee, creant ainsi un instrument plus simple.

Optical property determination of turbid media by time-resolved transmittance measurements and wavelet transform analysis

A method to independently quantify the absorption and the scattering properties of samples based on the analysis of the Haar transform (HT) of photon time-of-flight (TOF) distributions is described. A series of reflectance photon TOF measurements were acquired from absorbing/scattering milk samples of known composition (0 < μa < 0.025 mm-1; 100 < μs < 250 mm-1). The HT of the profiles was calculated, and the regression based on the most parsimonious subset of wavelets was determined by the genetic algorithm (GA). In addition, the utility of computing the logarithm of the profiles or of the absolute value of the wavelet coefficients before the GA was studied. Results show that the absorption coefficient could be estimated with a coefficient of variation (C.V.) of 6.7% and an r2 of 0.99 by use of the log of selected wavelets of frequency less than 800 MHz. Scattering coefficients were estimated with a C.V. of 2.3% and an r2 of 0.99 with the log of wavelets of frequency less than 400 MHz. The above results suggest that a simplified instrument based on low-frequency switches could be developed to quantify the optical properties of highly scattering media.

Claudia E. W. Gributs

Papers

Parsimonious calibration models for near-infrared spectroscopy using wavelets and scaling functions

In Vivo Near-Infrared Spectrometry

Multiresolution analysis for quantification of optical properties in scattering media using pulsed photon time-of-flight measurements

Optical property determination of turbid media by time-resolved transmittance measurements and wavelet transform analysis

Haar transform analysis of photon time-of-flight measurements for quantification of optical properties in scattering media