Biomedical optical analytical techniques to analyse the medicinal drugs and optical properties of tissues

Abstract: The spectral bio-diagnosis of normal human body saliva sample shows the following functional compounds and it is related to various proteins and enzymes. Because of the presence of water in the saliva sample, the hydroxyl group is observed in the form of O–H at 3,305 cm−1, because of the presence of lipids, the functional group C–H is obtained from 2,928 to 2,856 cm−1, due to the presence of amide-I in the form of C=N and C=C obtained at 1,658 cm−1, the proteins are exhibited. Due to the presence of aliphatic CH2, the Lipids, Adenine, Cytosine, Collagen are observed at 1,455 cm−1, because of the presence of Carbohydrates, Phospholipids, Nucleic acids, the functional groups C=O and P=O from 1,159 to 1,064 cm−1 are exhibited. Due to the presence of Phenylalanine, Tyrosine, Cystine and Hydroxyapatite C–C twist, C–C stretch, C–S stretch and PO42− are observed at 748 and 483 cm−1. Silver nanoparticle has attracted considerable interest due to their extensive applicability in various areas such as electronics, catalysis, chemistry, energy and medicine. To study the opto-electronics properties of the samples, it was mixed with silver nanoparticles and characterized.

Abstract: Needle insertion for minimally-invasive surgery is a technique explored and studied for percutaneous procedure, diagnosis, localised therapeutic drug-delivery, and biopsy. While the instruments and techniques determine the success of every surgical procedure, minimal attention was given to the medium, interaction between tissue and needle, development tools and surgical techniques. This paper addresses the interaction by studying the needle deflection during insertion into porcine back tissue and simulated flesh-like tissue (gelatine). A customised testing set-up measures and quantifies these interactions. Needle deflection magnitude and insertion forces were measured and correlated to define the bio-mechanical properties of back abdomen tissue. Needle deflections were measured for gelatine analogues developed to model consistency of the tissues in the back lumbar region. Mathematical two-dimensional (2D) force-model was developed to provide understanding on the mechanics of needle insertion. This study was the first-step in developing a deflection feedback controlled surgical instrument in the needle-assisted percutaneous operation.

Abstract: This consensus statement from the members of the American Neurogastroenterology and Motility Society and the Society of Nuclear Medicine recommends a standardized method for measuring gastric emptying (GE) by scintigraphy. A low-fat, egg-white meal with imaging at 0, 1, 2, and 4 h after meal ingestion, as described by a published multicenter protocol, provides standardized information about normal and delayed GE. Adoption of this standardized protocol will resolve the lack of uniformity of testing, add reliability and credibility to the results, and improve the clinical utility of the GE test.

Abstract: There is a real need for improvements in cancer detection. Significant problems are encountered when utilising the gold standard of excisional biopsy combined with histopathology. This can include missed lesions, perforation and high levels of inter- and intra-observer discrepancies. The clinical requirements for an objective, non-invasive real time probe for accurate and repeatable measurement of tissue pathological state are overwhelming. This study has evaluated the potential for Raman spectroscopy to achieve this goal. The technique measures the molecular specific inelastic scattering of laser light within tissue, thus enabling the analysis of biochemical changes that precede and accompany disease processes. Initial work has been carried out to optimise a commercially available Raman microspectrometer for tissue measurements; to target potential malignancies with a clinical need for diagnostic improvements (oesophagus, colon, breast, and prostate) and to build and test spectral libraries and prediction algorithms for tissue types and pathologies. This study has followed rigorous sample collection protocols and histopathological analysis using a board of expert pathologists. Only the data from samples with full agreement of a homogeneous pathology have been used to construct a training data set of Raman spectra. Measurements of tissue specimens from the full spectrum of different pathological groups found in each tissue have been made. Diagnostic predictive models have been constructed and optimised using multivariate analysis techniques. They have been tested using cross-validation or leave-one-out and demonstrated high levels of discrimination between pathology groups (greater than 90% sensitivity and specificity for all tissues). However larger sample numbers are required for further evaluation. The discussions outline the likely work required for successful implementation of in vivo Raman detection of early malignancies.

Abstract: Metabolic Profiling: Its Role in Biomarker Discovery and Gene Function Analysis offers guidelines to currently available technology and bioinformatics and database strategies now being developed. Evidence is presented that metabolic profiling is a valuable addition to genomics and proteomics strategies devoted to drug discovery and development, and that metabolic profiling offers numerous advantages.

Abstract: Raman spectroscopy (RS) is an optical technique that provides an objective method of pathological diagnosis based on the molecular composition of tissue. Studies have shown that the technique can accurately identify and grade prostatic adenocarcinoma (CaP) in vitro. This study aimed to determine whether RS was able to differentiate between CaP cell lines of varying degrees of biological aggressiveness. Raman spectra were measured from two well-differentiated, androgen-sensitive cell lines (LNCaP and PCa 2b) and two poorly differentiated, androgen-insensitive cell lines (DU145 and PC 3). Principal component analysis was used to study the molecular differences that exist between cell lines and, in conjunction with linear discriminant analysis, was applied to 200 spectra to construct a diagnostic algorithm capable of differentiating between the different cell lines. The algorithm was able to identify the cell line of each individual cell with an overall sensitivity of 98% and a specificity of 99%. The results further demonstrate the ability of RS to differentiate between CaP samples of varying biological aggressiveness. RS shows promise for application in the diagnosis and grading of CaP in clinical practise as well as providing molecular information on CaP samples in a research setting.

Abstract: We successfully acquire the in vivo Raman spectrum of melanin from human skin using a rapid near-infrared (NIR) Raman spectrometer. The Raman signals of in vivo cutaneous melanin are similar to those observed from natural and synthetic eumelanins. The melanin Raman spectrum is dominated by two intense and broad peaks at about 1580 and 1380 cm ˛1 , which can be interpreted as originating from the in-plane stretching of the aromatic rings and the linear stretching of the C-C bonds within the rings, along with some contributions from the C-H vibrations in the methyl and methylene groups. Variations in the peak frequencies and bandwidths of these two Raman signals due to differing biological environments have been observed in melanin from different sources. The ability to ac- quire these unique in vivo melanin signals suggests that Raman spec- troscopy may be a useful clinical method for noninvasive in situ analysis and diagnosis of the skin. © 2004 Society of Photo-Optical Instrumenta-