Raman Spectra Of Blood Research Articles

Micro-Raman spectroscopy study of blood samples from myocardial infarction patients

Acute myocardial infarction (MI) is found to be a major causative factor for global mortality and morbidity. This situation demands necessity of developing efficient and rapid diagnostic tools to detect acute MI. Raman spectroscopy is a non-destructive optical diagnostic technique, which has high potential in probing biochemical changes in clinical samples during initiation and progress of diseases. In this work, blood was taken as the sample to examine inflammation in acute MI patients using Raman spectroscopy. Ratio of Raman peak intensities that corresponds to phenylalanine (1000 cm−1) and tyrosine (825 cm−1) can facilitate indirect information about tetrahydrobiopterin (BH4) availability, which can indicate inflammatory status in patients. This ratio obtained was higher for MI patients in comparison with control subjects. The decrease in phenylalanine and tyrosine ratio (Phe-Tyr ratio) is attributed to the prognosis of standard of care (medications like antiplatelets including aspirin, statin and revascularisation) leading to inflammation reduction. Phe-Tyr ratio estimated from the Raman spectra of blood can be exploited as a reliable method to probe inflammation due to MI. The method is highly objective, require only microliters of sample and minimal sample preparation, signifying its clinical utility.

Clinical Study on Raman Spectra of Blood, Saliva and Urine in Patients With Cancer Treated by Modern Therapy

Clinical Study on Raman Spectra of Blood, Saliva and Urine in Patients With Cancer Treated by Modern Therapy

Application of Raman spectroscopy in comparative study of antiobesity influence of oxytocin and freeze‐dried extracts of Uvariodendron anisatum Verdeck (Annonaceae) in Sprague Dawley rats

AbstractObesity is a condition affecting a substantial number of people in the world. Obese people have increased risks of developing chronic metabolic diseases such as type II diabetes, hypertension, and cancer, among others. Predicting potential development together with rapid diagnosis of the condition followed by early interventions is therefore necessary. This work investigated, first, utility of Raman spectroscopy in performing comparative antiobesity influence studies of oxytocin and a freeze‐dried extract of a local herbal plant exhibiting oxytocin‐like properties called Uvariodendron anisatum Verdeck (Annonaceae) (UAV) on diet induced obesity in Sprague Dawley rat models. Second, we looked for obesity biomarker Raman spectral bands. The blood extracted from the rats were applied onto conductive silver paste smeared glass slides and excited using a 785‐nm laser. Raman spectra of blood from oxytocin‐ and UAV‐treated rats displayed similar profiles with low doses of UAV (100 mg/kg of body weight) being more similar to oxytocin than high doses (200 mg/kg of body weight) as revealed by cosine similarity value of 0.997. Their profiles were also different from blood of obese and nonobese (normal controls) animals. A prominent peak in spectra of treated rats centred at 401 cm−1 can be oxytocin's biomarker band in blood. Comparison of average intensity trend of fructose bands at around 638 and 812 cm−1 between prepared fructose solution and blood of treated rats revealed elevated levels of fructose in blood of rats intraperitoneally injected oxytocin and UAV extracts. The result implied upregulation of fructose in oxytocin‐ and UAV‐treated animals. Principal component analysis confirmed that Raman spectral profiles from blood of obese rats were different from those of nonobese rats with bands ascribed to fructose (638, 812, and 1,217 cm−1) and branched chain amino acids (BCAAs; 478, 1,318, and 1,443 cm−1), being utilized in the segregation of the spectral data sets. It also showed that spectra from oxytocin‐treated and UAV‐treated rat's blood were similar implying identical influence of the drugs on the animals. The study showed potential of Raman spectroscopy as tool for quick obesity (or metabolic syndrome) screening with intensity of Raman bands associated with fructose and BCAAs as biomarkers. Besides, the same bands may be used in comparative efficacy studies of antiobesity drugs. The results reported here are rare in literature.

Sexing of chicken eggs by fluorescence and Raman spectroscopy through the shell membrane.

In order to provide an alternative to day-old chick culling in the layer hatcheries, a noninvasive method for egg sexing is required at an early stage of incubation before onset of embryo sensitivity. Fluorescence and Raman spectroscopy of blood offers the potential for precise and contactless in ovo sex determination of the domestic chicken (Gallus gallus f. dom.) eggs already during the fourth incubation day. However, such kind of optical spectroscopy requires a window in the egg shell, is thus invasive to the embryo and leads to decreased hatching rates. Here, we show that near infrared Raman and fluorescence spectroscopy can be performed on perfused extraembryonic vessels while leaving the inner egg shell membrane intact. Sparing the shell membrane makes the measurement minimally invasive, so that the sexing procedure does not affect hatching rates. We analyze the effect of the membrane above the vessels on fluorescence signal intensity and on Raman spectrum of blood, and propose a correction method to compensate for it. After compensation, we attain a correct sexing rate above 90% by applying supervised classification of spectra. Therefore, this approach offers the best premises towards practical deployment in the hatcheries.

Differentiation of human blood from animal blood using Raman spectroscopy: A survey of forensically relevant species

The identification of blood samples is a crucial facet of forensic investigations, particularly for violent crimes. One step in forensic serology (i.e., the analysis of bodily fluids) that is often skipped or overlooked is the determination that a bloodstain is of human or nonhuman origin. Typically, subsequent to identifying a stain as blood using a presumptive blood test, which have the propensity of providing false positive results, the stain is submitted for extraction of a DNA profile to compare with those in a database. It is extremely uncommon that evidentiary bloodstains are confirmed as being of human origin throughout the serological analysis. Therefore, time, money, and other resources can be wasted on obtaining a DNA profile from a bloodstain that may not be of human origin; if the intent was to obtain a human DNA profile and not that of an animal. This work demonstrates an important advancement of a previous study for nondestructive differentiation of human and animal blood using Raman spectroscopy coupled with partial least squares discriminant analysis (PLSDA). Raman spectra of blood from six species of animals, not previously accounted for, including chimpanzee, deer, elk, ferret, fish, and macaque were used to test a PLSDA classification method. These animal species are forensically relevant since they are (i) involved in wildlife crimes, (ii) consumed by humans, or (iii) known to produce a false positive result when their blood is tested with certain presumptive human blood tests. An external validation sensitivity of 1.00 and specificity of 0.93 for human class predictions was obtained from the PLSDA model constructed for this study. Using receiver operating characteristic (ROC) analysis of external human class predictions, the PLSDA model demonstrated 99% accuracy in being able to correctly classify any random blood sample as human or nonhuman. This is a significant advancement over the previous work and a very important finding as it demonstrates the superb selectivity of the developed method with high accuracy in being able to correctly predict the nonhuman origin of bloodstains from unknown animal species.