Spectroscopy - Volume 25, issue 1

Authors: Guevara, Ramón | Stothers, Lynn | Macnab, Andrew

Article Type: Research Article

Abstract: Background: Near-infrared spectroscopy (NIRS) has recognized potential but limited application for non-invasive diagnostic evaluation. Data analysis methodology that reproducibly distinguishes between the presence or absence of physiologic abnormality could broaden clinical application of this optical technique. Methods: Sample data sets from simultaneous NIRS bladder monitoring and invasive urodynamic pressure-flow studies (UDS) are used to illustrate how a diagnostic algorithm is constructed using classification and regression tree (CART) analysis. Misclassification errors of CART and linear discriminant analysis (LDA) are computed and examples of other urological NIRS data likely amenable to CART analysis presented. Results: CART generated a clinically relevant …classification algorithm (error 4%) using 46 data sets of changes in chromophore concentration composed of the whole time series without specifying features. LDA did not (error 16%). Using CART NIRS data provided comparable discriminant ability to the UDS diagnostic nomogram for the presence or absence of obstructive pathology (88% specificity, 84% precision). Pilot data examples from children with and without voiding dysfunction and women with mild or severe pelvic floor muscle dysfunction also show potentially diagnostic differences in chromophore concentration. Conclusions: CART analysis can likely be applied in other NIRS monitoring applications intended to classify patients into those with and without pathology. Show more

Keywords: Classification and regression tree (CART), diagnostic algorithm, linear discriminant analysis, near-infrared spectroscopy, urodynamics

DOI: 10.3233/SPE-2010-0486

Citation: Spectroscopy, vol. 25, no. 1, pp. 1-11, 2011

Authors: Yu, Yun | Lin, Juqiang | Wu, Yanan | Feng, Shangyuan | Li, Yongzeng | Huang, Zufang | Chen, Rong | Zeng, Haishan

Article Type: Research Article

Abstract: Electroporation assisted metallic nanoparticle delivery has been shown by our previous work to significantly reduce the time of sample preparation for surface-enhanced Raman spectroscopy (SERS) measurements of biological cells. In this paper, we report our experimental work to optimize the electroporation parameters, including adjustment of the pulse pattern, operation temperature, and electroporation buffer, for fastest delivery of silver nanoparticles into living C666 cells (a human nasopharyngeal carcinoma cell line). The delivery efficiency was evaluated by the integrated intensity of whole cell SERS spectrum. Our work concluded that the silver nanoparticle delivery rate is best under the electroporation condition of using …4 consecutive 350 V (875 V/cm) rectangular electric pulses of 1, 10, 10 and 1 ms durations, respectively. Low temperature (0–4°C) is necessary for keeping cell viability during the electroporation process and it also improves the delivery efficiency of silver nanoparticles. The serum in the buffer has no obvious effect on the delivery efficiency. Show more

Keywords: Surface-enhanced Raman scattering (SERS), electroporation, silver nanoparticle delivery, C666 cell

DOI: 10.3233/SPE-2010-0493

Citation: Spectroscopy, vol. 25, no. 1, pp. 13-21, 2011

Authors: Lin, Duo | Lin, Juqiang | Wu, Yanan | Feng, Shangyuan | Li, Yongzeng | Yu, Yun | Xi, Gangqin | Zeng, Haishan | Chen, Rong

Article Type: Research Article

Abstract: The single-cell Raman spectra of human Burkitt's lymphoma cells (CA46) including cells treated with different doses of paclitaxel and controls without paclitaxel can be detected by confocal micro-Raman spectroscopy. It shows that the Raman bands at 1094 cm−1 assigned to the symmetric stretching vibration mode of O–P–O in the DNA backbone, 1338 cm−1 and 1578 cm−1 due to adenine and guanine of DNA all decrease in intensity with increasing drug dose. On the contrary, the intensity of peaks at 1257 cm−1 due to characteristic vibration of α-helix of Amide III and 1658 cm−1 due to …characteristic vibration of α-helix of Amide I both increases with increasing drug dose. Multivariate statistical methods, such as Principle Components Analysis (PCA) and Linear Discriminant Analysis (LDA) were employed to discriminate normal lymphoma cells (CA46) and cells treated with different doses of paclitaxel. It was found that the sensitivity and specificity of differentiating the treated and untreated cell groups increase with drug doses and approach 100% for the high drug dose, consistent with the perception that the cytotoxicity increases with drug dose. These results suggest that Raman spectroscopy combined with multivariate analysis could become a useful tool for assessing the cytotoxicity of drugs such as paclitaxel on human lymphoma cells. Show more

Keywords: Raman spectroscopy, paclitaxel, lymphoma, CA46, Principle Components Analysis (PCA), Linear Discriminant Analysis (LDA)

DOI: 10.3233/SPE-2011-0497

Citation: Spectroscopy, vol. 25, no. 1, pp. 23-32, 2011

Authors: Muntean, Cristina M. | Leopold, Nicolae | Halmagyi, Adela | Valimareanu, Sergiu

Article Type: Research Article

Abstract: Ultrasensitive detection of nucleic acids is demonstrated through exploiting the effect of surface-enhanced Raman scattering (SERS). In this work the SERS spectra of eight genomic DNAs from leaves of apple trees grown in the field (Malus domestica Borkh., Fam. Rosaceae, cultivars. Florina, Idared, Rebra, Goldrush, Romus 3, Romus 4 and the rootstocks M9 and M26) have been analyzed in the wavenumber range 200–1800 cm−1 . SERS signatures, spectroscopic band assignments and structural interpretations of these plant genomic DNAs are reported. SERS spectra of nucleic acids are compared here with caution, because these signals are time-dependent and are strongly influenced by …DNA amount in the measured sample volume. Similarities of the SERS spectra of genomic DNAs extracted from apple leaves of Goldrush, Rebra and Florina cultivars, respectively, have been detected. Besides, the SERS spectra, corresponding to DNA from M9, Romus 4 and M26, leaves, respectively, show similar features and well resolved bands. Based on this work, specific plant DNA-ligand interactions or DNA structural changes induced by plant stress conditions associated with their natural environment, might be further investigated using surface-enhanced Raman spectroscopy. Show more

Keywords: Surface-enhanced Raman scattering (SERS), genomic DNA, apple leaves

DOI: 10.3233/SPE-2010-0491

Citation: Spectroscopy, vol. 25, no. 1, pp. 33-43, 2011

Authors: Tomečková, Vladimíra | Gajová, Alena | Veliká, Beáta | Saxunová, Lýdia | Hertelyová, Zdenka

Article Type: Research Article

Abstract: This study was carried out to investigate isolated liver mitochondrial functions after paracetamol administration by monitoring of liver mitochondrial fluorescence properties as well as prooxidative properties of paracetamol. Paracetamol was administered to rat (in subtoxic 500 mg·kg−1 dose) in vivo. The effect of this dose was compared with the subtoxic and toxic dose of paracetamol added to mitochondria in vitro (1 and 1.5) mg paracetamol/mg mitochondrial protein. Subtoxic dose of paracetamol in vitro did not change mitochondrial fluorescence, but it significantly decreased mitochondrial fluorescence in vivo in comparison with control mitochondrial group. Toxic dose of paracetamol in vitro significantly …decreased mitochondrial fluorescence. The enzymatic activity of superoxide dismutase (SOD) significantly decreased after paracetamol administration in vitro and in vivo. While both activities of glutathione peroxidase (GPx) and glutathione reductase (GR) significantly increased in dependence upon paracetamol doses. Our experiment showed, that paracetamol participates in formation of free radicals and confirms previous studies, in which paracetamol administration caused elevation of antioxidative enzymes activities in dependence on dose, which is considered therapeutically as subtoxic and toxic. Show more

Keywords: Paracetamol, superoxide dismutase, glutathione peroxidase, glutathione reductase, fluorescence, synchronous fluorescence spectra

DOI: 10.3233/SPE-2011-0501

Citation: Spectroscopy, vol. 25, no. 1, pp. 45-51, 2011

Authors: Bratu, I. | Borodi, G. | Kacsó, Iren | Moldovan, Z. | Filip, C. | Dragan, Felicia | Vasilescu, M. | Simon, S.

Article Type: Research Article

Abstract: The aim of the present paper was to obtain new solid forms of Norfloxacin. For this purpose Norfloxacin was recrystallized from: acetic acid and its mixtures with several organic solvents. By recrystallization of Norfloxacin from acetic acid and from its mixture with several organic solvents a new solvate was found. To evidence this new solid form of Norfloxacin different investigation techniques were used: powder X-ray diffraction, FTIR, DSC, 13 C NMR spectroscopy and mass spectrometry. The solvate is consisting on Norfloxacin and acetic acid in 1:1 molar ratio and crystallizes in triclinic system and the cell parameters were determined also.

Keywords: FTIR, powder X-ray diffraction, DSC, MS, 13C NMR, Norfloxacin – acetic acid solvate

DOI: 10.3233/SPE-2010-0492

Citation: Spectroscopy, vol. 25, no. 1, pp. 53-62, 2011