The application of F magnetic resonance ex vivo imaging of three-dimensional cultured breast cancer cells to study the effect of δ-tocopherol

The aim of this study was to determine the role of δ-tocopherol in breast cancer cell growth ex vivo. Human gland mammary adenocarcinoma (MCF-7) and human T-lymphoblastoid (CEM) cells were cultured in the presence of δ-tocopherol at various concentrations (0-750 μM) for 5 days. We have grown 3D ex vivo breast cancer cell cultures in the hollow fiber bioreactor (HFBR). ¹⁹F magnetic resonance imaging (MRI) was used to evaluate oxygen concentration in the cell suspension and thus its viability.     

HDAC Inhibition Induces Increased Choline Uptake and Elevated Phosphocholine Levels in MCF7 Breast Cancer Cells

Histone deacetylase (HDAC) inhibitors have emerged as effective antineoplastic agents in the clinic. Studies from our lab and others have reported that magnetic resonance spectroscopy (MRS)-detectable phosphocholine (PC) is elevated following SAHA treatment, providing a potential noninvasive biomarker of response. Typically, elevated PC is associated with cancer while a decrease in PC accompanies response to antineoplastic treatment. The goal of this study was therefore to elucidate the underlying biochemical mechanism by which HDAC inhibition leads to elevated PC. We investigated the effect of SAHA on MCF-7 breast cancer cells using ¹³C MRS to monitor [1,2-¹³C] choline uptake and phosphorylation to PC. We found that PC synthesis was significantly higher in treated cells, representing 154±19% of control. This was within standard deviation of the increase in total PC levels detected by ³¹P MRS (129±7% of control). Furthermore, cellular choline kinase activity was elevated (177±31%), while cytidylyltransferase activity was unchanged. Expression of the intermediate-affinity choline transporter SLC44A1 and choline kinase α increased (144% and 161%, respectively) relative to control, as determined by mRNA microarray analysis with protein-level confirmation by Western blotting. Taken together, our findings indicate that the increase in PC levels following SAHA treatment results from its elevated synthesis. Additionally, the concentration of glycerophosphocholine (GPC) increased significantly with treatment to 210±45%. This is likely due to the upregulated expression of several phospholipase A2 (PLA₂) isoforms, resulting in increased PLA₂ activity (162±18%) in SAHA-treated cells. Importantly, the levels of total choline (tCho)-containing metabolites, comprised of choline, PC and GPC, are readily detectable clinically using ¹H MRS. Our findings thus provide an important step in validating clinically translatable non-invasive imaging methods for follow-up diagnostics of HDAC inhibitor treatment.     

Identification of mobile cholesterol compounds in experimental gliomas by (1)H MRS in vivo: effects of ganciclovir-induced apoptosis on lipids

This letter presents a novel identification and analysis of mobile cholesterol compounds in an experimental glioma model by (1)H MRS in vivo. The cholesterol compounds turned out to comprise as much as 17 mol% of MRS visible total lipids. The results also imply partly associated accumulation of (1)H MRS detectable cholesterol compounds and unsaturated lipids during gene therapy-induced apoptosis, and indicate that the contribution of cholesterol compounds cannot be bypassed in spectral lipid analysis. The introduced (1)H MRS approach facilitates a non-invasive follow-up of mobile cholesterol compounds, paving way for studies of tumour cholesterol metabolism in vivo.     

In vivo imaging of apoptosis in oncology: an update

In this review, data on noninvasive imaging of apoptosis in oncology are reviewed. Imaging data available are presented in order of occurrence in time of enzymatic and morphologic events occurring during apoptosis. Available studies suggest that various radiopharmaceutical probes bear great potential for apoptosis imaging by means of positron emission tomography and single-photon emission computed tomography (SPECT). However, for several of these probes, thorough toxicologic studies are required before they can be applied in clinical studies. Both preclinical and clinical studies support the notion that 99mTc-hydrazinonicotinamide-annexin A5 and SPECT allow for noninvasive, repetitive, quantitative apoptosis imaging and for assessing tumor response as early as 24 hours following treatment instigation. Bioluminescence imaging and near-infrared fluorescence imaging have shown great potential in small-animal imaging, but their usefulness for in vivo imaging in humans is limited to structures superficially located in the human body. Although preclinical tumor-based data using high-frequency-ultrasonography (US) are promising, whether or not US will become a routinely clinically useful tool in the assessment of therapy response in oncology remains to be proven. The potential of magnetic resonance imaging (MRI) and magnetic resonance spectroscopy (MRS) for imaging late apoptotic processes is currently unclear. Neither 31P MRS nor 1H MRS signals seems to be a unique identifier for apoptosis. Although MRI-measured apparent diffusion coefficients are altered in response to therapies that induce apoptosis, they are also altered by nonapoptotic cell death, including necrosis and mitotic catastrophe. In the future, rapid progress in the field of apoptosis imaging in oncology is expected.     

In vivo assessment of nodularin-induced hepatotoxicity in the rat using magnetic resonance techniques (MRI, MRS and EPR oximetry)

Acute nodularin-induced hepatotoxicity was assessed in vivo, in rats using magnetic resonance (MR) techniques, including MR imaging (MRI), MR spectroscopy (MRS), and electron paramagnetic resonance (EPR) oximetry. Nodularin is a cyclic hepatotoxin isolated from the cyanobacterium Nodularia spumigena. Three hours following the intraperitoneal (i.p.) administration of nodularin (LD50), a region of 'damage', characterized by an increase in signal intensity, was observed proximal to the porta hepatis (PH) region in T2-weighted MR images of rat liver. Image analysis of these regions of apparent 'damage' indicated a statistically significant increase in signal intensity around the PH region following nodularin administration, in comparison with controls and regions peripheral to the PH region. An increase in signal intensity was also observed proximal to the PH region in water chemical shift selective images (CSSI) of nodularin-treated rat livers, indicating that the increased signal observed by MRI is an oedematous response to the toxin. Microscopic assessment (histology and electron microscopy) and serum liver enzyme function tests (aminotransferase (ALT) and aspartate ALT (AST)) confirmed the nodularin-induced tissue injury observed by MRI. In vivo and in vitro MRS was used to detect alterations in metabolites, such as lipids, Glu+Gln, and choline, during the hepatotoxic response (2-3 h post-exposure). Biochemical assessment of perchloric acid extracts of nodularin-treated rat livers were used to confirm the MRS results. In vivo EPR oximetry was used to monitor decreasing hepatic pO2 (approximately 2-fold from controls) 2-3 h following nodularin exposure. In vivo MR techniques (MRI, MRS and EPR oximetry) are able to highlight effects that may not have been evident in single end point studies, and are ideal methods to follow tissue injury progression in longitudinally, increasing the power of a study through repeated measures, and decreasing the number of animals to perform a similar study using histological or biochemical techniques.     

Place de l’imagerie dans l’évaluation de l’efficacité des traitements dans le cancer du sein

This paper describes, from the current literature, the role of various imaging methods to assess the response to therapy in breast cancer. Two different clinical situations are considered: neoadjuvant chemotherapy of locally advanced breast cancer and the metastastic breast cancer. Significant clinical data are available for three criteria: the volume of the tumour, the uptake of fluorodeoxyglucose using PET and the perfusion of the tumor evaluated either by dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) or by PET using ¹⁵O water. ¹⁸F FDG PET allows prediction of the response after one or two cycles of neoadjuvant chemotherapy. New approaches will offer opportunities to refine the role of imaging in monitoring the response to chemotherapy. PET using thymidine as biomarker is promising in assessing the tissular proliferation. Estrogen analogs could be used to predict hormonally responsive breast cancer. Many other approaches, although less developed, might offer new insights in the response to therapy of breast cancer like magnetic resonance spectroscopy or optical imaging of hemoglobin oxygenation. Imaging also offers potential of monitoring the down-regulation of specialized receptors of the cell membrane in response to treatment: the most studied receptor in preclinical model has been the human epidermal growth factor receptor type 2 (HER2). Integrin, a family of cell adhesion receptor, is also an important target for imaging. Apoptosis, multidrug resistance and hypoxia can also be studied using appropriate biomarkers. To allow reliable multicenter trials of new drugs, these different imaging approaches still require an improved standardization of image acquisition and processing.     

Quantification of ethanol methyl 1H magnetic resonance signal intensity following intravenous ethanol administration in primate brain

In vivo ¹H magnetic resonance spectroscopy (MRS) can be used to directly monitor brain ethanol. Previously, studies of human subjects have lead to the suggestion that the ethanol methyl ¹H MRS signal intensity relates to tolerance to ethanol’s intoxicating effects. More recently, the ethanol ¹H MRS signal intensity has been recognized to vary between brain gray matter (GM), white matter (WM), and cerebrospinal fluid (CSF) due to differences in T₂ within these environments. The methods presented here extend ethanol MRS techniques to non-human primate subjects. Twelve monkeys were administered ethanol while sedated and positioned within a 3T MRI system. Chemical shift imaging (CSI) measurements were performed following intravenous infusion of 1 g/kg ethanol. Magnetic resonance imaging (MRI) data were also recorded for each monkey to provide volume fractions of GM, WM, and CSF for each CSI spectrum. To estimate co-variance of ethanol MRS intensity with GM, WM, and CSF volume fractions, the relative contribution of each tissue subtype was determined following corrections for radiofrequency pulse profile non-uniformity, chemical shift artifacts, and differences between the point spread function in the CSI data and the imaging data. The ethanol MRS intensity per unit blood ethanol concentration was found to differ between GM, WM, and CSF. Individual differences in MRS intensity were larger in GM than WM. This methodology demonstrates the feasibility of ethanol MRS experiments and analysis in non-human primate subjects, and suggests GM may be a site of significant variation in ethanol MRS intensity between individuals.     

Alteration in lipid composition differentiates breast cancer tissues: a <Superscript>1</Superscript>H HRMAS NMR metabolomic study

Introduction

Breast cancer is the most frequent diagnosed cancer among women with a mortality rate of 15% of all cancer related deaths in women. Breast cancer is heterogeneous in nature and produces plethora of metabolites allowing its early detection using molecular diagnostic techniques like magnetic resonance spectroscopy.

Objectives

To evaluate the variation in metabolic profile of breast cancer focusing on lipids as triglycerides (TG) and free fatty acids (FFA) that may alter in malignant breast tissues and lymph nodes from adjacent benign breast tissues by HRMAS ¹H NMR spectroscopy.

Methods

The ¹H NMR spectra recorded on 173 tissue specimens comprising of breast tumor tissues, adjacent tissues, few lymph nodes and overlying skin tissues obtained from 67 patients suffering from breast cancer. Multivariate statistical analysis was employed to identify metabolites acting as major confounders for differentiation of malignancy.

Result

Reduction in lipid content were observed in malignant breast tissues along with a higher fraction of FFA. Four small molecule metabolites e.g., choline containing compounds (Chocc), taurine, glycine, and glutamate were also identified as major confounders. The test set for prediction provided sensitivity and specificity of more than 90% excluding the lymph nodes and skin tissues.

Conclusion

Fatty acids composition in breast cancer using in vivo magnetic resonance spectroscopy (MRS) is gaining its importance in clinical settings (Coum et al. in Magn Reson Mater Phys Biol Med 29:1–4, 2016). The present study may help in future for precise evaluation of lipid classification including small molecules as a source of early diagnosis of invasive ductal carcinoma by employing in vivo magnetic resonance spectroscopic methods.

     

磁共振功能成像在监测乳腺癌新辅助化疗中的应用和进展

近年来,新辅助化疗在原发乳腺癌治疗中运用越来越广泛。影像学手段在评价新辅助化疗疗效、指导临床治疗方案的制定中发挥重要作用。磁共振功能成像的引入,可以加深对恶性乳腺肿瘤的病理生理活动及分子生物学特性的了解,监测化疗疗效,提高早期预测的准确性。本文总结功能学MRI(磁共振成像)探测乳腺癌患者生物标志物的研究现状及发展情况,描述各种生物学标志物特性,评价其潜在的临床应用价值和局限性。以下将对动态增强磁共振成像、弥散加权成像、血氧水平依赖成像以及波谱成像等几种磁共振功能学成像方法的原理进行描述,重点对其在监测乳腺癌新辅助化疗中的应用进行综述。     

High-field MR spectroscopy in the multiparametric MRI evaluation of breast lesions

IntroductionThe aim of this work was to assess the role of 3T-MR spectroscopy (MRS) in the multi-parametric MRI evaluation of breast lesions, using a pattern-recognition based classification method.Methods291 patients (301 lesions, median 2.3 cm³) were enrolled in the study (age 18–85 y, mean 54.2 y). T1-TSE (TR/TE = 400/10 ms) and T2-STIR imaging (TR/TE = 5000/60 ms), dynamic-contrast-enhanced MRI (DCE-MRI), apparent diffusion coefficient (ADC) (b = 0–800 s/mm²), and single-voxel MRS (10 × 10 × 10 mm³, PRESS, TR/TE = 3000 ms/135 ms) were performed by means of a 3T scanner. MRS results were accepted if the FWHM of the water peak was ⩽45 Hz. Total choline (tCho) was considered detected if the signal-to-noise ratio (SNR) of the 3.2 ppm peak was ⩾2. A classifier-based analysis (support-vector-machines, SVM) was performed with 4-dimensional vectors including type of margin, DCE-MRI kinetic curve type, ADC mean value, and tCho SNR. A comparison with 3-dimensional vectors (without tCho SNR) was used to assess MRS impact on sensitivity, specificity, and positive-negative predictive values (PPV-NPV) for malignancy.Results228 lesions (180 malignant/48 benign) showed acceptable spectral quality. Comparison of classification results with histopathological examination of surgical specimens showed sensitivity = 93.7%, specificity = 84.9%, PPV = 95.2%, NPV = 81.5% without the inclusion of MRS in the SVM analysis. When MRS was included, the figures increased to 95.1%, 90.7%, 97.2%, and 85.0%, respectively.ConclusionsInclusion of 3T-MRS in the multi-parametric MRI evaluation of breast lesions improved the performance of the SVM-based classifier, showing a possible role of high-field MR spectroscopy in the differential diagnosis between benign and malignant breast lesions. Further research is however needed to confirm this initial evidence.     

In Vivo NMR Studies of Neurodegenerative Diseases in Transgenic and Rodent Models

In vivo magnetic resonance spectroscopy (MRS) and magnetic resonance imaging (MRI) provide unique quality to attain neurochemical, physiological, anatomical, and functional information noninvasively. These techniques have been increasingly applied to biomedical research and clinical usage in diagnosis and prognosis of diseases. The ability of MRS to detect early yet subtle changes of neurochemicals in vivo permits the use of this technology for the study of cerebral metabolism in physiological and pathological conditions. Recent advances in MR technology have further extended its use to assess the etiology and progression of neurodegeneration. This review focuses on the current technical advances and the applications of MRS and MRI in the study of neurodegenerative disease animal models including amyotrophic lateral sclerosis, Alzheimer's, Huntington's, and Parkinson's diseases. Enhanced MR measurable neurochemical parameters in vivo are described in regard to their importance in neurodegenerative disorders and their investigation into the metabolic alterations accompanying the pathogenesis of neurodegeneration.     

The role of various modalities in breast imaging

Background: Breast cancer is the most common type of cancer in women worldwide. Mammography is considered the "gold standard" in the evaluation of the breast from an imaging perspective. Apart from mammography, ultrasound examination and magnetic resonance imaging are being offered as adjuncts to the preoperative workup. Recently, other new modalities like positron emission tomography, 99mTc-sestamibi scintimammography, and electrical impedance tomography (EIT) are also being offered. However, there is still controversy over the most appropriate use of these new modalities. Based on the literature, this review evaluates the role of various modalities used in the screening and diagnosis of breast cancer. Methods and Results: Based on relevant literatures this article gives an overview of the old and new modalities used in the field of breast imaging. A narrative literature review of all the relevant papers known to the authors was conducted. The search of literatures was done using pubmed and ovid search engines. Additional references were found through bibliography reviews of relevant articles. It was clear that though various new technics and methods have emerged, none have substituted mammography and it is still the only proven screening method for the breast as of date. Conclusion: From the literature it is clear that apropos modern radiology's impact on diagnosis, staging and patient follow-up, only one imaging technique has had a significant impact on screening asymptomatic individuals for cancer i.e.; low-dose mammography. Mammography is the only screening test proven in breast imaging. Positron emission tomography (PET) also plays an important role in staging breast cancer and monitoring treatment response. As imaging techniques improve, the role of imaging will continue to evolve with the goal remaining a decrease in breast cancer morbidity and mortality. Progress in the development and commercialisation of EIT breast imaging system will definitely help to promote other systems and applications based on the EIT and similar visualization methods. Breast ultrasound and breast magnetic resonance imaging (MRI) are frequently used adjuncts to mammography in today's clinical practice and these techniques enhance the radiologist's ability to detect cancer and assess disease extent, which is crucial in treatment planning and staging.     

Application of magnetic resonance imaging in zoology

Magnetic resonance imaging (MRI) is a noninvasive imaging technique that today constitutes one of the main pillars of preclinical and clinical imaging. MRI’s capacity to depict soft tissue in whole specimens ex vivo as well as in vivo, achievable voxel resolutions well below (100 μm)³, and the absence of ionizing radiation have resulted in the broad application of this technique both in human diagnostics and studies involving small animal model organisms. Unfortunately, MRI systems are expensive devices and have so far only sporadically been used to resolve questions in zoology and in particular in zoomorphology. However, the results from two recent studies involving systematic scanning of representative species from a vertebrate group (fishes) as well as an invertebrate taxon (sea urchins) suggest that MRI could in fact be used more widely in zoology. Using novel image data derived from representative species of numerous higher metazoan clades in combination with a comprehensive literature survey, we review and evaluate the potential of MRI for systematic taxon scanning. According to our results, numerous animal groups are suitable for systematic MRI scanning, among them various cnidarian and arthropod taxa, brachiopods, various molluscan taxa, echinoderms, as well as all vertebrate clades. However, various phyla in their entirety cannot be considered suitable for this approach mainly due to their small size (e.g., Kinorhyncha) or their unfavorable shape (e.g., Nematomorpha), while other taxa are prone to produce artifacts associated either with their biology (e.g., Echiura) or their anatomy (e.g., Polyplacophora). In order to initiate further uses of MRI in zoology, we outline the principles underlying various applications of this technique such as the use of contrast agents, in vivo MRI, functional MRI, as well as magnetic resonance spectroscopy. Finally, we discuss how future technical developments might shape the use of MRI for the study of zoological specimens.     

Phosphorus magnetic resonance spectroscopy: its utility in examining the membrane hypothesis of schizophrenia

A novel approach to understanding the pathophysiology of schizophrenia has been the investigation of membrane composition and functional perturbations, referred to as the "Membrane Hypothesis of Schizophrenia." The evidence in support of this hypothesis has been accumulating in findings in patients with schizophrenia of reductions in phospholipids and essential fatty acids various peripheral tissues. Postmortem studies indicate similar reductions in essential fatty acids in the brain. However, the use of magnetic resonance spectroscopy (MRS) has provided an opportunity to examine aspects of membrane biochemistry in vivo in the living brain. MRS is a powerful, albeit complex, noninvasive quantitative imaging tool that offers several advantages over other methods of in vivo biochemical investigations. It has been used extensively in investigating brain biochemistry in schizophrenia. Phosphorus MRS (31P MRS) can provide important information about neuronal membranes, such as levels of phosphomonoesters that reflect the building blocks of neuronal membranes and phosphodiesters that reflect breakdown products. 31P MRS can also provide information about bioenergetics. Studies in patients with chronic schizophrenia as well as at first episode prior to treatment show a variety of alterations in neuronal membrane biochemistry, supportive of the membrane hypothesis of schizophrenia. Below, we will briefly review the principles underlying 31P MRS and findings to date. Magnetic resonance spectroscopy (MRS) is a powerful, albeit complex, imaging tool that permits investigation of brain biochemistry in vivo. It utilizes the magnetic resonance imaging hardware. It offers several advantages over other methods of in vivo biochemical investigations. MRS is noninvasive, there is no radiation exposure, does not require the use of tracer ligands or contrast media. Because of it is relatively benign, repeated measures are possible. It has been used extensively in investigating brain biochemistry in schizophrenia.     

Stimulated rapid expression in vitro for early detection of in vivo T-cell receptor mutations induced by radiation exposure

The T-cell receptor (TCR) mutation assay for in vivo somatic mutations is a sensitive indicator of exposure to ionizing radiation. However, this assay cannot be immediately applied after radiation exposure because expression of a mutant phenotype may require as long as several months. In the present study, we eliminate this time lag by stimulating lymphocytes with a mitogen that can accelerate the turnover of TCR protein expression in T-cells. When lymphocytes obtained from healthy donors were irradiated with various doses of X-rays and cultured with human interleukin-2 after phytohemagglutinin (PHA) pulse stimulation, the mutant frequency (MF) of CD4⁺ T-cells increased dose dependently during the first 7 days, then decreased rapidly due to the growth disadvantage of mutant cells. This suggests that PHA stimulation can shorten the expression time of a mutant phenotype to within a week after radiation exposure. The relationship between radiation dose and TCR MF on the seventh day was best fitted by a linear-quadratic dose–response model. We applied this improved TCR mutation assay to gynecological cancer patients who received 5 days of localized radiotherapy, totaling about 10 Gy. The in vivo TCR MF in the patients did not change within a week after radiotherapy, whereas the in vitro TCR MF of PHA-stimulated lymphocytes from the same patients significantly increased 7 days after initiating culture. The estimated mean radiation dose to the peripheral blood lymphocytes of the cancer patients was about 0.9 Gy, based on the in vitro linear-quadratic dose–response curve. This estimated dose was close to that described in a previous report on unstable-type chromosome aberrations from cervical cancer patients after receiving the same course of radiotherapy. On the basis of these findings, we propose that the improved TCR mutation assay is a useful biological dosimeter for recent radiation exposure.     

1H/31P Polarization Transfer at 9.4 Tesla for Improved Specificity of Detecting Phosphomonoesters and Phosphodiesters in Breast Tumor Models

Purpose

To assess the ability of a polarization transfer (PT) magnetic resonance spectroscopy (MRS) technique to improve the detection of the individual phospholipid metabolites phosphocholine (PC), phosphoethanolamine (PE), glycerophosphocholine (GPC), and glycerophosphoethanolamine (GPE) in vivo in breast tumor xenografts.

Materials and Methods

The adiabatic version of refocused insensitive nuclei enhanced by polarization transfer (BINEPT) MRS was tested at 9.4 Tesla in phantoms and animal models. BINEPT and pulse-acquire (PA) ³¹P MRS was acquired consecutively from the same orthotopic MCF-7 (n = 10) and MDA-MB-231 (n = 10) breast tumor xenografts. After in vivo MRS measurements, animals were euthanized, tumors were extracted and high resolution (HR)-MRS was performed. Signal to noise ratios (SNRs) and metabolite ratios were compared for BINEPT and PA MRS, and were also measured and compared with that from HR-MRS.

Results

BINEPT exclusively detected metabolites with ¹H-³¹P coupling such as PC, PE, GPC, and GPE, thereby creating a significantly improved, flat baseline because overlapping resonances from immobile and partly mobile phospholipids were removed without loss of sensitivity. GPE and GPC were more accurately detected by BINEPT in vivo, which enabled a reliable quantification of metabolite ratios such as PE/GPE and PC/GPC, which are important markers of tumor aggressiveness and treatment response.

Conclusion

BINEPT is advantageous over PA for detecting and quantifying the individual phospholipid metabolites PC, PE, GPC, and GPE in vivo at high magnetic field strength. As BINEPT can be used clinically, alterations in these phospholipid metabolites can be assessed in vivo for cancer diagnosis and treatment monitoring.     

Cardiac diastolic dysfunction in high-fat diet fed mice is associated with lipotoxicity without impairment of cardiac energetics in vivo

Obesity is often associated with abnormalities in cardiac morphology and function. This study tested the hypothesis that obesity-related cardiomyopathy is caused by impaired cardiac energetics. In a mouse model of high-fat diet (HFD)-induced obesity, we applied in vivo cardiac ³¹P magnetic resonance spectroscopy (MRS) and magnetic resonance imaging (MRI) to investigate cardiac energy status and function, respectively. The measurements were complemented by ex vivo determination of oxygen consumption in isolated cardiac mitochondria, the expression of proteins involved in energy metabolism, and markers of oxidative stress and calcium homeostasis. We also assessed whether HFD induced myocardial lipid accumulation using in vivo ¹H MRS, and if this was associated with apoptosis and fibrosis. Twenty weeks of HFD feeding resulted in early stage cardiomyopathy, as indicated by diastolic dysfunction and increased left ventricular mass, without any effects on systolic function. In vivo cardiac phosphocreatine-to-ATP ratio and ex vivo oxygen consumption in isolated cardiac mitochondria were not reduced after HFD feeding, suggesting that the diastolic dysfunction was not caused by impaired cardiac energetics. HFD feeding promoted mitochondrial adaptations for increased utilization of fatty acids, which was however not sufficient to prevent the accumulation of myocardial lipids and lipid intermediates. Myocardial lipid accumulation was associated with oxidative stress and fibrosis, but not apoptosis. Furthermore, HFD feeding strongly reduced the phosphorylation of phospholamban, a prominent regulator of cardiac calcium homeostasis and contractility. In conclusion, HFD-induced early stage cardiomyopathy in mice is associated with lipotoxicity-associated oxidative stress, fibrosis, and disturbed calcium homeostasis, rather than impaired cardiac energetics.     

Proton magnetic resonance spectroscopy in the diagnosis of breast cancer

Magnetic resonance spectroscopy (MRS) is used in mammalogy to specify the data obtained by traditional radiodiagnostic techniques and provides a possibility of estimating the molecular composition of pathologically altered breast tissues. This information is employed for the differential diagnosis of malignant and benign neoplasms, as well as for monitoring and predicting the efficiency of chemotherapy for breast cancer. Some technical problems and the lack of a standardized approach to the procedure of a study and interpretation of its results hinder the wide introduction of spectroscopy into clinical practice. This paper reviews the data available in the literature on proton MRS and the technical and clinical aspects of application of this technique.     

Functional in vivo imaging of cysteine cathepsin activity in murine model of inflammation

Near-infrared fluorophore (NIRF)-labeled imaging probes are becoming increasingly important in bio-molecular imaging applications, that is, in animal models for tumor imaging or inflammation studies. In this study we showed that the previously introduced chemical concept of ‘Reverse Design’ represents an efficient strategy for the generation of selective probes for cysteine proteases from chemically optimized protease inhibitors for investigations in proteomic lysates as well as for in vivo molecular imaging studies. The newly developed activity-based probe AW-091 was demonstrated to be highly selective for cathepsin S in vitro and proved useful in monitoring cysteine cathepsin activity in vivo, that is, in zymosan-induced mouse model of inflammation. AW-091 showed higher signal-to-background ratios at earlier time points than the commercially available polymer-based ProSense680 (VisEn Medical) and thus represents an efficient new tool for studying early proteolytic processes leading to various diseases, including inflammation, cancer, and rheumatoid arthritis. In addition, the fluorescent signal originating from the cleaved AW-091 was shown to be reduced by the administration of an anti-inflammatory drug, dexamethasone and by the cathepsin inhibitor E-64, providing a valuable system for the evaluation of small-molecule inhibitors of cathepsins.     

Magnetic resonance spectroscopy and measurement of tau epitopes of autopsy proven sporadic Creutzfeldt-Jakob disease in a patient with non-specific initial EEG, MRI and negative 14-3-3 immunoblot

Limited potential of electroencephalogram (EEG), magnetic resonance images (MRI) and cerebrospinal fluid (CSF) test for 14-3-3 protein in the clinical diagnosis of sporadic Creutzfeldt-Jakob disease (sCJD) resulted in developments in diagnostic premortem tehniques. Recent studies provided evidence that magnetic resonance spectroscopy (MRS) and measurement of total-tau (T-tau) and phospho-tau (P-tau) may be useful to identify patients with CJD. We combined detected metabolic changes in the brain by MRS and measured T-tau and tau-pT181 by ELISA, and tau-pT231 by Westernblot in a patient with autopsy proven sCJD. Our results show that in contrast to negative CSF 14-3-3 protein, nonspecific EEG and MRI, MRS revealed metabolic alterations in regions of the brain that has appeared normal on MRI, and tau tests has shown measurable levels of phosphorylated and non-phosphorylated isoforms in CSF. We conclude that rapidly progressive dementia with negative 14-3-3 test and non-specific initial EEG and MRI must still be considered in the differential diagnosis of the sCJD. Combination of serial functional MRI along with MRS study and measurement of tau ratio could improve the early diagnosis of sCJD. The current case is the first attempt to study results of the use of MRS and tau tests in a case of sCJD with diagnostic dilemma.