Spectroscopy - Volume 17, issue 2-3

Authors: Macnab, Andrew J. | Gagnon, Roy E. | Gagnon, Faith A. | Blackstock, Derek | LeBlanc, Jacques G.

Article Type: Research Article

Abstract: During cardiac surgery, bypass pumps rely on pressure monitors to evaluate flow. We studied whether it would be possible to optimize pump flow by monitoring changes in cerebral cytochrome a,a3 using NIRS to maintain cyt redox status at its pre‐bypass level. Method: 18 healthy 7–45 kg swine were placed on bypass for repeated cycles of cooling and re‐warming from 36 to 15 to 36°C in 3°C steps. Between each cycle, the swine's bypass pump blood flow rate was adjusted to restore cytochrome redox status to its pre‐bypass value. Results: In all swine trials, the number of pump flow alterations …imposed by NIRS monitoring ranged from 0 to 42, the average being 14 per trial. The best trial had 22 pump flow adjustments during which the range of cytochrome redox status change was 0.50±0.06 μmol l−1 . The average trial had a range of cytochrome redox status change of 1.50±0.22 μmol l−1 . Conclusion: NIRS‐driven alterations in pump flow rate to maintain pre‐bypass cytochrome redox status can be achieved successfully in the animal model. Show more

Keywords: Spectrophotometry, nasopharyngeal, cytochrome, NIRO‐300, oxygenation status

Citation: Spectroscopy, vol. 17, no. 2-3, pp. 477-482, 2003

Authors: Macnab, Andrew J. | Gagnon, Roy E. | Gagnon, Faith A. | LeBlanc, Jacques G.

Article Type: Research Article

Abstract: Near infrared spectroscopy (NIRS) monitors changes in oxygenated haemoglobin (HbO2 ), and redox status of cytochromeaa3 (cyt) continuously and non‐invasively in living tissue. We present examples where clinically relevant changes in HbO2 and/or cyt were detected in real time, allowing intervention to avert potentially harmful hypoxic‐ischaemic damage to the brain and/or spinal cord. Brain monitoring: In children undergoing surgery on cardiopulmonary bypass, observations include that: atrial fibrillation (cardiac arrhythmia) lowered cerebral HbO2 concentration; concealed haemorrhage decreased cerebral HbO2 concentration; inadequate level of anaesthetic resulted in spikes of changes in volume with interventions such as suturing; circulatory …arrest reduced brain HbO2 and cyt redox status; and bypass pump problems compromised cerebral blood flow. Spinal cord monitoring: In the experimental animal, we observed that NIRS detected ischaemic change immediately following aortic compression, spinal column distraction (instrumentation to separate the vertebrae), and hypoxia. In an infant requiring release of a congenitally tethered spinal cord, we observed that traction on the spinal cord of the infant resulted in decreased total haemoglobin concentration. Summary: NIRS brain monitoring probably represents the “standard of care” during cardiac surgery because adverse events can be detected and quantified. Similarly, spinal cord monitoring could reduce ischaemic spinal cord damage in spinal cord surgery and aortic aneurysm repair. Show more

Citation: Spectroscopy, vol. 17, no. 2-3, pp. 483-490, 2003

Authors: Zhang, Zhi‐Yi

Article Type: Research Article

Abstract: The LC/MS/MS warfarin assay, combining stereo‐ and regioselective cytochrome P450 (CYP) form‐specific warfarin hydroxylation with sensitive and specific LC/MS/MS detection technique, is emerging to be a promising tool for the study of CYP‐associated drug–drug interactions for new chemical entities (NCEs) during drug discovery process.

Citation: Spectroscopy, vol. 17, no. 2-3, pp. 491-502, 2003

Authors: Brandon Bravo Bruinsma, G.J. | van Echteld, C.J.A.

Article Type: Research Article

Abstract: Hemodynamic instability of the brain dead potential heart donor is an exclusion criterion for heart donation for transplantation. Based on the results of myocardial biopsies it has been reported that brain death‐related catecholamine induced damage of the heart causes depletion of high‐energy phosphates which could explain contractile dysfunction. Our group has shown in a series of 31 P MRS experiments in cats that neither the onset of brain death, nor the hemodynamic deterioration which follows, nor its treatment with high dosages of dopamine affect the heart energetically as expressed by PCr/ATP ratios. However, after cardioplegic arrest and explantation, an initial …and prolonged lower ATP content and an anomalous higher PCr/ATP ratio in the brain death group was found when compared with controls during long‐term unperfused cold storage of the hearts. During subsequent reperfusion of the hearts, ATP and PCr levels in the brain death group were lower than in controls but equal partial recovery of PCr/ATP ratios was observed in both groups. It was concluded that PCr/ATP ratios need to be interpreted with great caution. Secondly, brain death‐related hemodynamic instability is not related to significant changes of myocardial energy metabolism. Thirdly, brain death does affect the myocardial energy metabolism but the impact became apparent only during hypothermic storage and subsequent reperfusion of the donor heart. Show more

Citation: Spectroscopy, vol. 17, no. 2-3, pp. 503-510, 2003

Authors: Wang, Gangfeng | Hsieh, Yunsheng | Cheng, K.‐C. | Ng, Kwokei | Korfmacher, Walter A.

Article Type: Research Article

Abstract: A high‐throughput semi‐automated procedure for simultaneously stability evaluation of multiple compounds in plasma using direct single column high‐performance liquid chromatography (HPLC) combined with tandem mass spectrometry (MS/MS) was developed to eliminate the laborious procedures that are traditionally used for stability studies. Untreated human, monkey, mouse and rat plasma samples containing ten drug components were directly injected into a mixed‐functional column that provided both protein removal and chromatographic functionality. Ten test compounds were simultaneously assayed using a tandem mass spectrometer in the positive ion mode using multiple reaction monitoring (MRM). Plasma samples containing ten test compounds were placed in a thermostatic …autosampler and then sequentially monitored in one analytical procedure. The time between each injection was set about 7 minutes. The peak responses of the test compounds in individual plasma samples were repeatedly determined every 28 minutes. Drug stability in plasma was indicated by the change of the mass chromatographic peak areas for the test compounds and was observed to be a function of animal species, incubation time and incubation temperature. The potential for matrix ionization suppression on the direct single column HPLC‐MS/MS system was also investigated using the post‐column infusion technique. The proposed cassette assay procedure provides an analytical throughput ten times greater than the single component approach for the evaluation of drug stability in plasma without compromising data quality. Show more

Citation: Spectroscopy, vol. 17, no. 2-3, pp. 511-519, 2003

Authors: Thomas, M. Albert | Binesh, Nader | Yue, Kenneth | Banakar, Shida | Wyckoff, Nathaniel | Huda, Amir | Marumoto, Alan | Raman, Steve

Article Type: Research Article

Abstract: Localized 2D shift‐correlated MR spectra (L‐COSY) of human prostates were recorded using an endorectal “receive” coil. Typically, 4 ml voxels were placed in the peripheral zones of the prostate. Seven healthy volunteers and one BPH patient have participated in this study so far. The total acquisition time for a 2D L‐COSY was approximately 20 minutes. A 1.5 Tesla GE scanner with a body coil for RF transmission and a pelvic phased‐array coil combined with a disposable rectal coil for reception was used. The 2D L‐COSY spectra showed cross peaks due to citrate, spermine and occasionally choline, creatine and lipids. The …2D cross peaks due to both the multiplets of spermine were clearly resolved from choline and creatine which has been a major problem with the conventional MR spectroscopic techniques. In contrast to 2D JPRESS, improved spectral dispersion, less crowded 2D cross peaks and unequivocal detection of both multiplets of spermine were monitored in 2D L‐COSY. Pilot results suggest that localized 2D L‐COSY can be successfully implemented in human prostates on a clinical scanner. Show more

Keywords: Prostate, spermine, citrate, 2D L‐COSY, endorectal

Citation: Spectroscopy, vol. 17, no. 2-3, pp. 521-527, 2003

Authors: Kataoka, Mikio | Kamikubo, Hironari | Nakagawa, Hiroshi | Parker, Stewart F. | Smith, Jeremy C.

Article Type: Research Article

Abstract: We have applied inelastic neutron scattering (INS) to the understanding of protein dynamics. INS spectrum of staphylococcal nuclease (SNase) at 25 K in the energy range between 100 and 4000 cm−1 is compared with the result of normal mode calculation. The theoretical spectrum is in general agreement with experiment and is used to assign the peaks. INS spectra show some significant differences for the folded and the unfolded SNase. The intensity distribution of INS spectrum is different from protein to protein reflecting the differences in amino acid composition. INS is unique and effective for the study of protein dynamics, …especially for comparison with theory. Show more

Citation: Spectroscopy, vol. 17, no. 2-3, pp. 529-535, 2003

Authors: Ohlenschläger, Oliver | Wöhnert, Jens | Ramachandran, Ramadurai | Sich, Christian | Görlach, Matthias

Article Type: Research Article

Abstract: Ribonucleic acids (RNA) and RNA–protein complexes are essential components of biological information transfer, catalytic processes and are associated with regulatory functions. This broad range of biological functions is paralleled at the conformational level by a large number of non‐canonical structural elements or sequences with non‐standard backbone conformations, e.g., loops, bulges, pseudo‐knots and complex tertiary folds. NMR spectroscopy has evolved to a powerful tool for the determination of ribonucleic acid structures of up to 20 kDa. Uniform or selective stable isotope labelling aids in solving assignment problems arising from the inherently limited chemical shift dispersion and overlap of resonances for larger …nucleotide sequences. Recent developments of multi‐dimensional heteronuclear NMR pulse sequences allow e.g., to directly observe the hydrogen bonding pattern of canonical Watson–Crick base pairs as well as of unusual types of base pairs, thereby opening up a fast access to secondary structure screening of RNA. Detailed conformational descriptions are obtained using conventional NOE and J coupling‐derived data, nowadays supplemented by information from residual dipolar couplings. The latter method also provides a new means for the probing of dynamical features of ribonucleic acids. Show more

Keywords: RNA, NMR, structure determination, stable isotope labelling

Citation: Spectroscopy, vol. 17, no. 2-3, pp. 537-547, 2003

Authors: Miura, Hajime | McCully, Kevin | Chance, Britton

Article Type: Research Article

Abstract: Near infrared spectroscopy (NIRS) is a developing technique that measures the balance between muscle oxygen consumption and oxygen supply that is noninvasive and potentially portable. Differential absorption of light in the 600–900 nm region detects the changes in small vessel hemoglobin oxygen saturation and blood volume. Recent developments include the combining of multiple light sources and photodetectors to provide “images” of oxygen saturation and blood volume of wide regions of muscle. Using multiple NIRS imaging device, we monitored localized muscle metabolism during various exercises in the field as well as in the laboratory. In healthy subjects, the regional differences in …oxygen saturation and blood volume were detected in the medial head of the gastrocnemius muscle during a standing plantar flexion exercise, consistent with differences in intramuscular pressure. Patients with peripheral arterial disease (PAD) showed slower recovery for both oxygenation and blood volume after exercise. Treatment for PAD resulted in improvements in NIRS‐measured recovery times. In summary, NIRS devices have the ability to detect and monitor impaired muscle circulation. In addition, NIRS devices with multiple channels have the potential to evaluate the regional differences in oxygen status. Multiple NIRS imaging devices have the potential to play an important role in monitoring exercise prescription and clinical uses. Show more

Citation: Spectroscopy, vol. 17, no. 2-3, pp. 549-558, 2003

Authors: Auguin, D. | Catherinot, V. | Malliavin, T.E. | Pons, J.L. | Delsuc, M.A.

Article Type: Research Article

Abstract: We are here addressing the problem of the automatic determination of a protein structure at atomic resolution, by using only the signal recorded on three spectra: 2D 15 N HSQC, 3D 15 N NOESY‐HSQC and TOCSY‐HSQC. A modified version of the neural network RESCUE (J.L. Pons and M.A. Delsuc, J. Biomol. NMR 15 (1999), 15–26), N15‐RESCUE, is developed in order to predict the amino‐acid type from only the 15 N, HN, Hα and Hβ chemical shifts. The spatial distances between protein residues are estimated by automatic comparison of columns extracted from a 3D 15 N NOESY‐HSQC spectrum, using the FIRE …method (T.E. Malliavin, P. Barthe and M.A. Delsuc, Theor. Chem. Accts 106 (2001), 91–97). The predictions provided by both FIRE and N15‐RESCUE methods are then used for the determination of a preliminary NMR structure of the protein p8. A mean RMSD value of 2.31±0.86 Å is observed between the coordinates of heavy atoms from helices αI and αII, and the αIII helix is taking random orientations with respect to the other helices. This random orientation is a consequence of the lack of predicted proximities between αIII and αII, and is in agreement with other independent observations made on p8 structure. Show more

Keywords: Nuclear magnetic resonance, NMR, structure prediction, computer‐aided assignment, data processing, neural network, chemical shift index

Citation: Spectroscopy, vol. 17, no. 2-3, pp. 559-568, 2003

Authors: Severcan, Feride | Kaptan, Neşe | Turan, Belma

Article Type: Research Article

Abstract: Application of mid infrared spectroscopy in diabetic tissues will be presented which highlight the promise of this technique in medical research. Examples presented mainly will focus on diabetic rat heart crude membranes. Diabetes mellitus (DM) was induced in rats by streptozotocin (STZ) injection that is one of the most popular experimental models for the study of type I diabetes. The shift in the peak positions, bandwidths and the intensity of the bands in FTIR spectra were analyzed to have valuable structural and functional information, which may have diagnostic value. In the diabetic membranes significant increase was observed in lipid order …and lipids concentration. While the concentration of saturated lipids increases, the concentration of unsaturated lipids decreases. In addition, broadening of the amide I bands and the appearance of the new band around 1640 cm−1 together with the decrease in the amide I to amide II ratio indicate the structural changes occurring in proteins of diabetic membranes. A dramatic increase in oligosaccarite band (1042 cm−1 ) and a decrease in olefinic stretching band (3012 cm−1 ), were also observed. Show more

Keywords: Diabetes, heart membrane, FTIR

Citation: Spectroscopy, vol. 17, no. 2-3, pp. 569-577, 2003

Authors: Breen, E.J. | Holstein, W.L. | Hopwood, F.G. | Smith, P.E. | Thomas, M.L. | Wilkins, M.R.

Article Type: Research Article

Abstract: High throughput proteomics is realized not only by the use of automated hardware but also by the application of efficient, automated software routines to complex data. In this paper, we present the recent developments of our software tool Peak Harvester for the automatic harvesting of monoisotopic peaks from MALDI‐TOF mass spectra of peptides. Peak Harvester uses advanced mathematical morphology to convert mass spectra into stick representations. Poisson modeling of theoretical isotopic distributions is then applied to derive the monoisotopic peptide mass from an isotopically resolved group of peaks. The accuracy of Peak Harvester is demonstrated via the analysis of peptide …spectra from low concentrations of bovine serum albumin blotted onto PVDF membranes and of tryptic digested platelet proteins derived from human blood following two‐dimensional gel electrophoresis. The results demonstrate the power of this software as it can accurately assign monoisotopic masses, including those from overlapping isotopic distributions, and picks masses as accurately as an experienced human operator. We have further developed Peak Harvester to include peak harvesting from MALDI‐TOF Post Source Decay (PSD) experiments. Here we demonstrate the versatility of the software by both the analysis of PSD data from 2DE and the analysis of peptide mass spectra collected directly from tryptic digests on a PVDF membrane. Show more

Keywords: Mathematical morphology, proteomics, MALDI‐TOF, isotopic distribution, Poisson, identification

Citation: Spectroscopy, vol. 17, no. 2-3, pp. 579-595, 2003

Authors: de Oliveira Nunes, Lilian | Martin, Aírton Abrahão | Silveira Jr., Landulfo | Zampieri, Marcelo

Article Type: Research Article

Abstract: Early detection of cancer is still a great challenge in clinical oncology. Recently, Raman spectroscopy has been used for skin lesion detection. FT‐Raman spectroscopy is a modern analytical tool and its use for cancer diagnosis will lead to several advantages for the patient as, for example, real time and less invasive diagnosis. The primary objective of this work was to use FT‐Raman spectroscopy to detect spectral changes between benign and malignant (basal cell carcinoma – BCC) skin tissues. Those spectral changes can provide important information about the biochemical alterations between these two types of tissues. We have analyzed by FT‐Raman …eight set of samples histopathologically diagnosed as BCC and made a comparison with five set of samples diagnosed as benign tissue. We have found that the main spectral differences between these samples were in the shift region of 1220–1300 cm−1 and 1640–1680 cm−1 . The vibration bands in these regions correspond to the amide III and to the amide I vibrations, respectively. Principal components analysis applied over all 13 samples could identify tissue type with 100% of sensitivity and specificity. Show more

Keywords: FT‐Raman spectroscopy, skin cancer, diagnosis, principal components analysis

Citation: Spectroscopy, vol. 17, no. 2-3, pp. 597-602, 2003

Authors: Sergi, Giuseppe | Bertani, Roberta | Calliari, Irene | Lupoli, Lucia | Berton, Adriano | Volpato, Stefania | Enzi, Giuliano

Article Type: Research Article

Abstract: Large interest is into the determination of body fluids because of changes in body water in a wide variety of physiological and pathological conditions. Here methods based on dilution of tracers, are reported, for the extracellular water (ECW) and total body water (TBW) determinations on the same sample. As for ECW, bromide is used as tracer and its concentration is determined by energy dispersive X‐ray spectrometry; while as for TBW, D2 O is used as tracer and HOD is determined by FT IR. Both methods represent significant improvements with respect the procedures described in the literature in terms of availability, …reproducibility and accuracy. Show more

Citation: Spectroscopy, vol. 17, no. 2-3, pp. 603-611, 2003

Authors: Minunni, M.

Article Type: Research Article

Abstract: DNA sensing is an emerging technology based on hybridisation reaction between an immobilised DNA probe and a molecular target, consisting of a probe complementary sequence in solution. Many application have been developed in the field of environmental, food and clinical analysis. Surface plasmon resonance and piezoelectric sensing are reported as transduction principles for DNA‐based devices. These techniques are able to monitor in real‐time and without the use of any label the hybridisation reaction between nucleic acids. Particular attention is given to Genetically Modified Organism detection.

Keywords: Biosensor, DNA sensing, nucleic acids, hybridisation reaction

Citation: Spectroscopy, vol. 17, no. 2-3, pp. 613-625, 2003

Authors: Boyar, Handan | Turan, Belma | Severcan, Feride

Article Type: Research Article

Abstract: Diabetes mellitus (DM) can be accepted as a heterogenous multi organ disorder that can affect various systems of the human body. Disorders include retinopathy, neuropathy, cardiomyopathy, musculoskeletal abnormalities such as diminished bone formation and bone healing retardation. Low bone mineral density is often mentioned as a complication for patients with insulin dependent diabetes mellitus (type I DM). Streptozotocin (STZ) induced diabetic rats are good models for investigation of the complications of insulin dependent diabetes. In the present study, the effects of STZ induced diabetes on the mineral environment of rat bones namely femur and tibia were studied by Fourier transform …infrared (FTIR) spectroscopic technique. The results revealed that mineral crystal sizes increased and carbonate content decreased for diabetic femur and tibia. These changes can be due to the formation of osteoporosis which is widely seen in diabetic patients. Show more

Keywords: Diabetes, FTIR, rat bone, femur, tibia, mineral crystal size

Citation: Spectroscopy, vol. 17, no. 2-3, pp. 627-633, 2003

Article Type: Correction

Citation: Spectroscopy, vol. 17, no. 2-3, pp. 635-635, 2003

Article Type: Other

Citation: Spectroscopy, vol. 17, no. 2-3, pp. 637-637, 2003