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Background: Metastases to the central nervous system from different primary cancers are an oncologic challenge as the overall prognosis for these patients is generally poor. The incidence of brain metastases varies with type of primary cancer and is probably increasing due to improved therapies of extracranial metastases prolonging patient's overall survival and thereby time for brain metastases to develop. In addition, the greater access to improved neuroimaging techniques can provide earlier diagnosis. The aim of this study was to investigate the feasibility of using proton magnetic resonance spectroscopy (MRS) and multivariate analyses to characterize brain metastases originating from different primary cancers, to assess changes in spectra during radiation treatment and to correlate the spectra to clinical outcome after treatment., Methods: Patients (n = 26) with brain metastases were examined using single voxel MRS at a 3T clinical MR system. Five patients were excluded due to poor spectral quality. The spectra were obtained before start (n = 21 patients), immediately after (n = 6 patients) and two months after end of treatment (n = 4 patients). Principal component analysis (PCA) and partial least square regression analysis (PLS) were applied in order to identify clustering of spectra due to origin of metastases and to relate clinical outcome (survival) of the patients to spectral data from the first MR examination., Results: The PCA results indicated that brain metastases from primary lung and breast cancer were separated into two clusters, while the metastases from malignant melanomas showed no uniformity. The PLS analysis showed a significant correlation between MR spectral data and survival five months after MRS before start of treatment., Conclusion: MRS determined metabolic profiles analysed by PCA and PLS might give valuable clinical information when planning and evaluating the treatment of brain metastases, and also when deciding to terminate further therapies.

Background: High-resolution magic angle proton magnetic resonance spectroscopy (HR 1H MAS MRS) provides a broad metabolic mapping of intact tumor samples and allows for microscopy investigations of the samples after spectra acquisition. Experimental studies have suggested that the method can be used for detection of apoptosis, but this has not been investigated in a clinical setting so far. We have explored this hypothesis in cervical cancers by searching for metabolites associated with apoptosis that were not influenced by other histopathological parameters like tumor load and tumor cell density., Methods: Biopsies (n = 44) taken before and during radiotherapy in 23 patients were subjected to HR MAS MRS. A standard pulse-acquire spectrum provided information about lipids, and a spin-echo spectrum enabled detection of non-lipid metabolites in the lipid region of the spectra. Apoptotic cell density, tumor cell fraction, and tumor cell density were determined by histopathological analysis after spectra acquisition., Results: The apoptotic cell density correlated with the standard pulse-acquire spectra (p < 0.001), but not with the spin-echo spectra, showing that the lipid metabolites were most important. The combined information of all lipids contributed to the correlation, with a major contribution from the ratio of fatty acid -CH2 to CH3 (p = 0.02). In contrast, the spin-echo spectra contained the main information on tumor cell fraction and tumor cell density (p < 0.001), for which cholines, creatine, taurine, glucose, and lactate were most important. Significant correlations were found between tumor cell fraction and glucose concentration (p = 0.001) and between tumor cell density and glycerophosphocholine (GPC) concentration (p = 0.024) and ratio of GPC to choline (p < 0.001)., Conclusion: Our findings indicate that the apoptotic activity of cervical cancers can be assessed from the lipid metabolites in HR MAS MR spectra and that the HR MAS data may reveal novel information on the metabolic changes characteristic of apoptosis. These changes differed from those associated with tumor load and tumor cell density, suggesting an application of the method to explore the role of apoptosis in the course of the disease.

Purpose: The purpose of the present study was to investigate metabolic changes in different compartments of the rat lens (anterior, nuclear, posterior, and equatorial) after exposure to an acute double threshold dose of ultraviolet-B radiation (UVR-B) by using high-resolution magic angle spinning (HR-MAS) (1)H nuclear magnetic resonance (NMR) spectroscopy and pattern recognition (PR) METHODS: methods. One eye in each of 28 6-week-old female albino Sprague-Dawley rats was exposed to in vivo 7.5 kJ/m2 UVR-B for 15 minutes. The contralateral eye was left unexposed. One week after irradiation, all rats were killed, and both lenses were isolated. Each lens was cored by a trephine, and the cylinder was sliced into three portions (anterior, nuclear, and posterior). The lens material that remained after the coring process was analyzed as the equatorial region. Analysis of lens metabolism was performed by HR-MAS 1H NMR spectroscopy (14.1 T; Avance DRX600; Bruker BioSpin GmbH, Rheinstetten, Germany), and the metabolic profiles were statistically analyzed by the PR method of principal component analysis (PCA)., Results: Metabolic differences were detected among the compartments in the lens, both in samples from the contralateral nonexposed lenses and in samples from lenses exposed to in vivo UVR-B. In the rat lens, exposure to UVR-B caused changes in GSH, phosphocholine, myo-inositol, succinate, formate, and adenosine triphosphate (ATP)/adenosine diphosphate (ADP) and in levels of the amino acids phenylalanine, taurine, hypo-taurine, tyrosine, alanine, valine, isoleucine, and glutamate, that varied among lens compartments., Conclusions: HR-MAS 1H NMR spectroscopy, combined with PR methods (PCA), is effective for analysis of separate parts of the intact rat lens. To understand the biochemistry of the lens, it is important to divide the lens into sections, representing functionally and anatomically distinct compartments.

Background: Children with very low birth weight (VLBW) have a significantly increased risk of later neurodevelopmental problems, while infants born small for gestational age (SGA) at term are also at some risk of developing neurological impairment., Objective: To investigate possible brain metabolite differences in adolescents with VLBW, SGA at term and controls by proton in vivo magnetic resonance spectroscopy (MRS) at 1.5 T., Materials and Methods: MR spectra were acquired from volumes localized in the left frontal lobe, containing mainly white matter (54 subjects). Peak areas of N-acetyl aspartate (NAA), choline (Cho) and creatine (Cr) were determined, and the peak area ratio of NAA to Cr, total Cho to Cr, or NAA to Cho calculated. Probabilistic neural network (PNN) analysis was performed utilizing the chemical shift region containing resonances from NAA, Cho and Cr as inputs., Results: No significant difference in the peak area ratios could be found using the Kruskal-Wallis test. By application of PNN, a correct classification of 52 of the 54 adolescents with a sensitivity and specificity exceeding 93% for all groups was achieved., Conclusion: Small, yet systematic, differences in brain metabolite distribution among the groups were confirmed by PNN analysis.

Breast cancer is the most frequent form of cancer in women and improved diagnostic methods are desirable. Malignant cells have altered metabolism and metabolic mapping might become a tool in cancer diagnostics. High-resolution magic angle spinning (HR MAS) MR spectroscopy of tissue biopsies provides detailed information on metabolic composition. The 600 MHz 1H HR MAS spectra were acquired of breast cancer tissue from 85 patients and adjacent non-involved tissue from 18 of these patients. Tissue specimens were investigated by microscopy after MR analysis. The resulting spectra were examined by three different approaches. Relative intensities of glycerophosphocholine (GPC), phosphocholine (PC) and choline were compared for cancerous and non-involved specimens. Eight metabolites, choline, creatine, beta-glucose, GPC, glycine, myo-inositol, PC and taurine, were quantified from the recorded spectra and compared with tumor histological type and size, patient's lymph node status and tissue composition of sample. The spectra were also compared with tumor histological type and size, lymph node status and tissue composition of samples using principal component analysis (PCA). Tumor samples could be distinguished from non-involved samples (82% sensitivity, 100% specificity) based on relative intensities of signals from GPC, PC and choline in 1H HR MAS spectra. Tissue concentrations of metabolites showed few differences between groups of samples, which can be caused by limitations in the quantification procedure. Choline and glycine concentrations were found to be significantly higher in tumors larger than 2 cm compared with smaller tumors. PCA of MAS spectra from patients with invasive ductal carcinomas indicated a possible prediction of spread to axillary lymph nodes. Metabolite estimates and PCA of MAS spectra were influenced by the percentage of tumor cells in the investigated specimens., (2006 John Wiley & Sons, Ltd.)

Purpose: The aim of the study was to investigate the metabolic profiles of intact rabbit corneas and lenses exposed to UVA and UVB radiation by using high-resolution (HR) magic angle spinning (MAS) (1)H nuclear magnetic resonance (NMR) spectroscopy and pattern recognition methods., Methods: Adult albino rabbits were exposed to UVA (366 nm, 0.589 J/cm(2)) or UVB (312 nm, 1.667 J/cm(2)) radiation for 8 min, once a day for 5 days. Three days after the last irradiation day, samples of corneas and lenses were dissected. HR-MAS (1)H NMR spectroscopy combined with pattern recognition methods (principal component analysis and soft independent modelling of class analogy) and one-way ANOVA were applied to obtain metabolic information from intact corneal and lens tissue., Results: UVB irradiation caused statistically significant metabolic changes in the rabbit corneas. A decrease in metabolites as ascorbate (84%), myo-inositol (59%), hypotaurine (91%) and choline (76%) was observed. Exposure to UVA radiation caused no significant metabolic alteration in this tissue. The metabolic profile of the rabbit lenses showed no detectable changes after UVA or UVB exposure., Conclusions: The combination of HR-MAS (1)H NMR spectroscopy and multivariate methods proved effective to analyse intact corneal and lens tissue after exposure to UV radiation of different wavelengths. By avoiding extraction methods and obtaining complete metabolic profiles from one sample, HR-MAS (1)H NMR spectroscopy provided important information about metabolic alteration occurring in rabbit corneal and lens tissue after UV exposure.

This work investigates the suitability of (1)H NMR spectroscopy to identify the fate of some bioactive compounds in seafood submitted to several processing conditions and examines the possibility of using (1)H NMR spectroscopy profiling to classify such products. Perchloric acid extracts of cod white muscle from newly killed and (i) unprocessed, (ii) boiled, and (iii) fried fillets and from (iv) frozen fillets, (v) the frozen fillets after thawing, and (vi) their drip loss and from (vii) rehydrated cod klippfish (n = 5) were analyzed by 500 MHz (1)H NMR spectroscopy. It was possible to identify taurine, betaine, anserine, creatine, and trimethylamine oxide (TMAO) in all extracts examined, and frozen fish was recognizable by the presence of dimethylamine (DMA). None of the heating procedures seemed to induce the loss of bioactive compounds from the fillet, but freezing and thawing did: the compounds were lost in what is known as drip loss. About 80% of the samples were correctly classified using a probabilistic neural network procedure having as inputs the scores of the first 20 principal components of the principal component analysis of a selected region of the NMR spectra.

Purpose: This study was conducted to investigate metabolic changes in aqueous humor from rabbit eyes exposed to either UV-A or -B radiation, by using (1)H nuclear magnetic resonance (NMR) spectroscopy and unsupervised pattern recognition, Methods: methods. Both eyes of adult albino rabbits were irradiated with UV-A (366 nm, 0.589 J/cm(2)) or UV-B (312 nm, 1.667 J/cm(2)) radiation for 8 minutes, once a day for 5 days. Three days after the last irradiation, samples of aqueous humor were aspirated, and the metabolic profiles analyzed with (1)H NMR spectroscopy. The metabolic concentrations in the exposed and control materials were statistically analyzed and compared, with multivariate methods and one-way ANOVA., Results: UV-B radiation caused statistically significant alterations of betaine, glucose, ascorbate, valine, isoleucine, and formate in the rabbit aqueous humor. By using principal component analysis, the UV-B-irradiated samples were clearly separated from the UV-A-irradiated samples and the control group. No significant metabolic changes were detected in UV-A-irradiated samples., Conclusions: This study demonstrates the potential of using unsupervised pattern recognition methods to extract valuable metabolic information from complex (1)H NMR spectra. UV-B irradiation of rabbit eyes led to significant metabolic changes in the aqueous humor detected 3 days after the last exposure.

The neuronal ceroid lipofuscinoses (NCLs) are among the most severe inherited progressive neurodegenerative disorders of children. The purpose of this study was to compare the in vivo 1.5-T 1H magnetic resonance (MR) and ex vivo 14.3-T high-resolution (HR) magic angle spinning (MAS) 1H MR brain spectra of patients with infantile (CLN1) and juvenile (CLN3) types of NCL, to obtain detailed information about the alterations in the neuronal metabolite profiles in these diseases and to test the suitability of the ex vivo HR MAS (1)H MRS technique in analysis of autopsy brain tissue. Ex vivo spectra from CLN1 autopsy brain tissue (n = 9) significantly differed from those of the control (n = 9) and CLN3 (n = 5) groups, although no differences were found between the CLN3 and the control groups. Principal component analysis of ex vivo data showed that decreased levels of N-acetylaspartate (NAA), gamma-aminobutyric acid (GABA), glutamine, and glutamate as well as increased levels of inositols characterized the CLN1 spectra. Also, the intensity ratio of lipid methylene/methyl protons was decreased in spectra of CLN1 brain tissue compared with CLN3 and control brain tissue. In concordance with the ex vivo data, the in vivo spectra of late-stage patients with CLN1 (n = 3) revealed a dramatic decrease of NAA and a proportional increase of myo-inositol and lipids compared with control subjects. Again, the spectra of patients with CLN3 (n = 13) did not differ from those of controls (n = 15). In conclusion, the ex vivo and in vivo spectroscopic findings were in good agreement within all analyzed groups and revealed significant alterations in metabolite profiles in CLN1 brain tissue but not in CLN3 compared with controls. Furthermore, HR MAS 1H MR spectra facilitated refined detection of neuronal metabolites, including GABA, and composition of lipids in the autopsy brain tissue of NCL patients.

Objective: In recent years, high-resolution magic angle spinning (HR MAS) has provided the opportunity to explore detailed biochemical composition of intact tissue. Previous studies of intact cervical biopsies with high-resolution magnetic resonance spectroscopy (MRS) have correlated well with histopathology. Lactate level in cervical cancer tissue has been found to correlate to metastatic spread. The purpose of this study was to explore the potential of the HR MAS technique as a tool for chemical characterization of cervical cancer tissue., Materials and Methods: Tissue samples from the cervix were collected after hysterectomy from patients with cervical cancer (n=8) and patients with nonmalignant disease (n=8). The tissue specimens were analyzed using HR MAS MR spectroscopy combined with principal component analysis (PCA)., Results: The resulting spectra showed resolution comparable with high-resolution MR spectra of extracts. Multivariate analysis confirmed that MAS spectra classified according to patient diagnosis., Conclusion: Malignant tissue of the cervix differed from nonmalignant tissue with regard to higher levels of cholines and amino acid residues and lower levels of glucose.