Imaging of pH in vivo using hyperpolarized 13C-labelled zymonic acid

Natural pH regulatory mechanisms can be overruled during several pathologies such as cancer, inflammation and ischaemia, leading to local pH changes in the human body. Here we demonstrate that ¹³C-labelled zymonic acid (ZA) can be used as hyperpolarized magnetic resonance pH imaging sensor. ZA is synthesized from [1-¹³C]pyruvic acid and its ¹³C resonance frequencies shift up to 3.0 p.p.m. per pH unit in the physiological pH range. The long lifetime of the hyperpolarized signal enhancement enables monitoring of pH, independent of concentration, temperature, ionic strength and protein concentration. We show in vivo pH maps within rat kidneys and subcutaneously inoculated tumours derived from a mammary adenocarcinoma cell line and characterize ZA as non-toxic compound predominantly present in the extracellular space. We suggest that ZA represents a reliable and non-invasive extracellular imaging sensor to localize and quantify pH, with the potential to improve understanding, diagnosis and therapy of diseases characterized by aberrant acid-base balance.

Local pH alterations can be manifestations of pathologies such as cancer, inflammation and ischaemia. Here Düwel et al. show hyperpolarized ¹³C-labelled zymonic acid can be used as a non-invasive probe to map and measure pH in vivo, suggesting it as a candidate for clinical imaging and a diagnostic tool.

Progressive pseudorheumatoid arthritis of childhood (PPAC). A hereditary disorder simulating rheumatoid arthritis

Five patients are described with a hereditary arthropathy affecting major and minor joints. The main features of this progressive connective tissue disorder are restricted joint mobility, osseous swelling of the interphalangeal and other joints, and platyspondyly. The condition is commonly misdiagnosed as "chronic juvenile polyarthritis with Scheuermann disease". It differs from the rheumatoid-factor-negative polyarticular form of rheumatoid arthritis and other rheumatoid spondylarthropathies by the absence of arthritic and other inflammatory changes, radiographically by the absence of destructive and the presence of dysplastic bone changes. The disorder does not seem to respond to the usual forms of antirheumatoid treatment. Histological studies showed a peculiar, nest-like clustering of chondrocytes in the resting and growth cartilage suggesting that pathogenetically this is a primary disorder of the articular cartilage.

[Azithromycin: an anti-inflammatory effect in chronic recurrent multifocal osteomyelitis? A preliminary report]

In this preliminary communication we report our experience with Azithromycin in patients with Chronic Recurring Multifocal Osteomyelitis (CRMO). Seven out of 13 patients, mainly teenager, showed a fast clinical improvement after they were started on Azithromycin. The immediate therapeutic effect of Azithromycin in patients with CRMO was surprising and lead us to the hypothesis that Azithromycin could have an antiphlogistic in addition to it's antibiotic effect in this disease setting. In patients with reactive chronic pelvic osteomyelitis Azithromycin obviously had a direct influence on the sympathic coxitis. Half of the patients reported an immediate reduction of pain and a significant improvement in range of movement after they were started on Azithromycin. In all cases the clinical and radiographic signs on MRI showed a reduction of the inflammatory process. Experimental animal models have recently shown that macrolids have independent additional antiinflammatory and immunomodulatory effects. The assumed local immunomodulatory effect of Azithromycin potentially is an additional activity to the already known synergistic antimicrobial and antiinflammatory effect. Right now we are in the process of collecting data from patients with SAPHO Syndrome who underwent bone-biopsies for microbiologic and histomorphologic investigations. All patients with the growth of propionibacterium acnes were started on a long-term antibiotic therapy with Azithromycin. This study will possibly help to answer the question of the additional antiphogistic/immunomodulatory effect of Azithromycin in this disease entity and the related CRMO.

MRI measurements of reporter-mediated increases in transmembrane water exchange enable detection of a gene reporter

Non-invasive imaging of gene expression can be used to track implanted cells in vivo but often requires the addition of an exogenous contrast agent that may have limited tissue access. We show that the urea transporter (UT-B) can be used as a gene reporter, where reporter expression is detected using 1H MRI measurements of UT-B-mediated increases in plasma membrane water exchange. HEK cells transfected with the reporter showed an increased apparent water exchange rate (AXR), which increased in line with UT-B expression. AXR values measured in vivo, in UT-B-expressing HEK cell xenografts, were significantly higher (about twofold, P < 0.0001), compared with non-expressing controls. Fluorescence imaging of a red fluorescent protein (mStrawberry), co-expressed with UT-B showed that UT-B expression correlated in a linear fashion with AXR. Transduction of rat brain cells in situ with a lentiviral vector expressing UT-B resulted in about a twofold increase in AXR at the site of virus injection.

Prognostic significance of DNA di-tetraploidy in neuroblastoma

BACKGROUND

Identification of biological factors may provide tools to discriminate poor risk neuroblastoma patients of diagnosis, to ultimately offer risk adapted treatment intensity.

PROCEDURES

Tumour cell DNA content, MYCN amplification (NMA), deletion of the short arm of chromosome 1 (del 1p) as well as three serological markers were assessed in 179 children with neuroblastoma.

RESULTS

Localised regional disease (stage 1 to 3) was diagnosed in 98 patients, and disseminated disease in 81 patients (65 with stage 4, 16 with stage 4s). Median age at diagnosis was 12 months and the median observation time 4 years. Sixty-seven of 179 patients had near di-tetraploid tumours (37%), with a significantly worse prognosis of 44% overall survival at 4 years in comparison with 88% in near triploid tumours (P < .001). The near di-tetraploid group showed a significant correlation with additional adverse biological factors (NMA, del 1p: P < 0.001), age over 1 year (P< 0.001), clinical stage 4 (P< 0.001), elevated ferritin (P = 0.023), and elevated LDH (P< 0.001). Multivariate analysis based on the overall (OS) and event free survival (EFS) estimations revealed that near di-tetraploidy was the most powerful biological factor, with a P-value of <0.001 for EFS and OS, followed by NMA (P = 0.015) for OS and del 1p (P= 0.047) for EFS.

CONCLUSIONS

This analysis underlines the important influence of near di-tetraploidy on prognosis, and suggests that more efforts should be undertaken to implement this factor in future studies.

[SAPHO syndrome: clinico-rheumatologic and radiologic differentiation and classification of a patient sample of 86 cases]

Synovitis (inflammatory arthritis), acne (pustulosa), pustulosis (psoriasis, palmoplantar pustulosis), hyperostosis (acquired), and ostitis (bland osteomyelitis) are symptoms forming the acronym SAPHO, which is a syndrome of nosologic heterogeneity. All entities forming the SAPHO syndrome are connected by a non-obligate dermatoskeletal association with an aseptic pustulous character. 86 cases were analyzed clinically, radiologically and by histology/histopathology. 31 adult patients showed the typical triad of pustulosis palmo-plantaris (psoriatica, PPP), sterno-costo-clavicular hyperostosis (SCCH), and "productive" spondylopathy, which we define as entity I. spondarthritis hyperostotica pustulopsoriatica (Spond.hyp.pp). Twelve adolescent and 13 adult patients showed entity no. II: chronic recurrent multifocal osteomyelitis (CRMO), being characterized by non-purulent osteomyelitis of plasma-cell sclerotic type, potentially being a reactive inflammatory process. 50% of the adult patients with CRMO showed PPP. Differentiation between these two entities is possible by detection of ossifying enthesiopathy in cases of Spond. hyp.pp and primarily chronic osteomyelitis in cases of CRMO. Two more entities or abortive forms of group I and II are III: the inflammatory syndrome of the anterior chest-wall (ACW syndrome) and IV: the more productive form of isolated sterno-costoclavicular hyperostosis (SCCH). Both are connected quite frequently to HLA-B-27-independent forms of spondarthritis and to pustulous dermatosis. More rarely we find osteo-articular symptoms in cases of acne pustulosa, which form group V: acne-associated spondarthritis and CRMO in the case of acne. Adult forms of CRMO with different forms of appearance (lumosacro-iliac hyperostosis with retroperitobeal fibrosis, pelvic type with affection of the hip-joint) are described. The immunologic theory of a "reactive osteomyelitis" potentially triggered by saprophytes is described. The inverse acne triad is brought in a context of skin symptoms. A case of intercurrent postpartum symptoms together with ulcerative colitis is described. Three cases of patients with Crohn's disease are described. Clinical features, radiological findings, and histopathological elements are brought together to determine the connections between the different entities and the possibilities of differentiation. With these elements together with bone-scan, it is often not necessary to obtain a bone specimen. Therapeutical possibilities, especially concerning CRMO, are discussed. "SAPHO syndrome" is more a sign-post on the way to a more subtle diagnosis when it comes to hyperostotic, skin-associated diseases, and it needs interdisciplinary work to clear the situation.

10 years' neuroblastoma screening in Europe: preliminary results of a clinical and biological review from the Study Group for Evaluation of Neuroblastoma Screening in Europe (SENSE)

Between January 1986 and May 1996, 870,313 children were tested in European neuroblastoma (NB) screening programmes. Among these children, 82 cases of NB (age range 4-24 months, median 11 months) were detected by screening. 83% of the patients had localised NB and 17% were diagnosed with generalised NB (stage 4, 10%; stage 4s, 7%). Unfavourable biological markers (MYCN amplification, loss of heterozygosity (LOH) 1p36, DNA di/tetraploidy) were observed in 14% of 76 biologically examined cases. The median follow-up time of all the patients was 21.5 months (range 1-101 months). To date, 69 patients are in complete remission (CR) and 2 patients have died due to therapy (stage 4, 1 patient; stage 3, 1 patient with unfavourable markers). Apart from screened patients, 16 other patients with NB were found who had previously had a normal screening test, i.e. 'false negative' patients (age range 10-41 months, median 31.5 months). The median interval between screening and diagnosis was 24.5 months (range 6-35 months). 11 of the 'false negative' patients suffered from generalised NB (stage 4) and 5 had localised NB at diagnosis. Unfavourable biological markers were observed in 7/12 patients. 5 patients have died, 2 achieved partial remission and 9 CR. 9 of the 11 patients with unfavourable biological markers diagnosed due to NB screening are currently in CR. It is very likely that, among the patients without unfavourable biological markers, we detected tumours which may have regressed spontaneously. These children may have undergone 'unnecessary,' but unavoidable, diagnostic procedures and therapy. To reduce the number of 'false negative' patients, a later screening could be helpful and should be evaluated.

Simultaneous characterization of tumor cellularity and the Warburg effect with PET, MRI and hyperpolarized 13C-MRSI

Modern oncology aims at patient-specific therapy approaches, which triggered the development of biomedical imaging techniques to synergistically address tumor biology at the cellular and molecular level. PET/MR is a new hybrid modality that allows acquisition of high-resolution anatomic images and quantification of functional and metabolic information at the same time. Key steps of the Warburg effect-one of the hallmarks of tumors-can be measured non-invasively with this emerging technique. The aim of this study was to quantify and compare simultaneously imaged augmented glucose uptake and LDH activity in a subcutaneous breast cancer model in rats (MAT-B-III) and to study the effect of varying tumor cellularity on image-derived metabolic information.

Methods: For this purpose, we established and validated a multimodal imaging workflow for a clinical PET/MR system including proton magnetic resonance (MR) imaging to acquire accurate morphologic information and diffusion-weighted imaging (DWI) to address tumor cellularity. Metabolic data were measured with dynamic [¹⁸F]FDG-PET and hyperpolarized (HP) ¹³C-pyruvate MR spectroscopic imaging (MRSI). We applied our workflow in a longitudinal study and analyzed the effect of growth dependent variations of cellular density on glycolytic parameters.

Results: Tumors of similar cellularity with similar apparent diffusion coefficients (ADC) showed a significant positive correlation of FDG uptake and pyruvate-to-lactate exchange. Longitudinal DWI data indicated a decreasing tumor cellularity with tumor growth, while ADCs exhibited a significant inverse correlation with PET standard uptake values (SUV). Similar but not significant trends were observed with HP-¹³C-MRSI, but we found that partial volume effects and point spread function artifacts are major confounders for the quantification of ¹³C-data when the spatial resolution is limited and major blood vessels are close to the tumor. Nevertheless, analysis of longitudinal data with varying tumor cellularity further detected a positive correlation between quantitative PET and ¹³C-data.

Conclusions: Our workflow allows the quantification of simultaneously acquired PET, MRSI and DWI data in rodents on a clinical PET/MR scanner. The correlations and findings suggest that a major portion of consumed glucose is metabolized by aerobic glycolysis in the investigated tumor model. Furthermore, we conclude that variations in cell density affect PET and ¹³C-data in a similar manner and correlations of longitudinal metabolic data appear to reflect both biochemical processes and tumor cellularity.

Die chronische rekurrierende multifokale Osteomyelitis in Assoziation mit chronisch entz�ndlichen Darmerkrankungen: Die enteropathische CRMO

The enterogenic reactive arthritides and entheropathic spondyloarthropathies are well-known entities. The so-called gut iteropathy concept offers an interesting working hypothesis to link the gut inflammation and the lymphocytic infiltration of the synovium. However, the association of rheumatic diseases belonging to the entity of the SAPHO syndrome with inflammatory bowel diseases (IBD) has only been rarely described in the literature. Among 138 cases of our (heterogenic) SAPHO cohort, we detected 5 patients (1 male, 4 females) with a proven association of SAPHO syndrome with IBD (in 4 cases Crohn's disease, in 1 case ulcerative colitis). Two patients belonged to the juvenileadolescent form and 3 to the adult form of SAPHO syndrome. In all cases the underlying osteoarticluar disease was classified as chronic recurrent multifocal osteomyelitis (CRMO), 2 of them presenting as inflammatory anterior chest wall syndrome. There was a strong association with psoriatic pustular dermatitis. Thus, we present 5 cases of "enteropathic CRMO" demonstrating several analogies to the enteropathic spondyloarthropathies. Both disease entities have in common i) metachronic development with osteoarticluar manifestations often preceding the gastrointestinal disease; ii) Crohn's like lesions that may develop from the stomach to the colon; iii) concomittent or intermittent skin pustulosis which mostly resolves; iiii) the gastrointestinal disease that often dominates the whole syndrome namely in the longterm follow-up. We suggest to transfer the hypothesis of the gut-synovium axis of enteropathic spondyloarthropathies to the entity of CRMO. This concept offers an opportunity to link the target organs gut mucosa, bone marrow and the skin via homing of antigen specific lymphocytes. This concept may help to better understand the pathogenesis of the "Skibo" (i. e., skin-bone) disease CRMO.

Cannabidiol converts NFκB into a tumor suppressor in glioblastoma with defined antioxidative properties

Background

The transcription factor NF-κB drives neoplastic progression of many cancers including primary brain tumors (glioblastoma [GBM]). Precise therapeutic modulation of NF-κB activity can suppress central oncogenic signaling pathways in GBM, but clinically applicable compounds to achieve this goal have remained elusive.

Methods

In a pharmacogenomics study with a panel of transgenic glioma cells, we observed that NF-κB can be converted into a tumor suppressor by the non-psychotropic cannabinoid cannabidiol (CBD). Subsequently, we investigated the anti-tumor effects of CBD, which is used as an anticonvulsive drug (Epidiolex) in pediatric neurology, in a larger set of human primary GBM stem-like cells (hGSC). For this study, we performed pharmacological assays, gene expression profiling, biochemical, and cell-biological experiments. We validated our findings using orthotopic in vivo models and bioinformatics analysis of human GBM datasets.

Results

We found that CBD promotes DNA binding of the NF-κB subunit RELA and simultaneously prevents RELA phosphorylation on serine-311, a key residue that permits genetic transactivation. Strikingly, sustained DNA binding by RELA-lacking phospho-serine 311 was found to mediate hGSC cytotoxicity. Widespread sensitivity to CBD was observed in a cohort of hGSC defined by low levels of reactive oxygen species (ROS), while high ROS content in other tumors blocked CBD-induced hGSC death. Consequently, ROS levels served as a predictive biomarker for CBD-sensitive tumors.

Conclusions

This evidence demonstrates how a clinically approved drug can convert NF-κB into a tumor suppressor and suggests a promising repurposing option for GBM therapy.

[Chronic recurrent multifocal osteomyelitis-- I. Review]

Juvenile and adolescent "Chronic Recurrent Multifocal Osteomyelitis" (CRMO) is described on the basis of literature and analysis of 43 own cases (23 cases in children or adolescents). This systemic, non-purulent inflammatory disease occurs mainly metaphyseal in long bones, in pelvic bones or as spondylitis and is not as rare as it seemed. Basis of the disease is a primarily chronic, sterile, in phase of onset often monotopic (e.g. clavicle) and later frequently polytopic osteomyelitis, possibly triggered by an immuno-pathological process (e.g. Proprionibacterium acnes), and showing histologically plasmacellular invasion and a sclerosing process in different stages. Association with pustulous dermatosis (psoriasis, acne, palmo-plantar pustulosis) is found in about 25 % of children and adolescents and in more than 50 % of the adult patients. 5 differents types of distribution of osteomyelitic lesions can be found by using Te99m-bone scan primarily, of which the "pelvic type" is the most common. Because of the close neighbourhood of meta-/epiphyseal osteomyelitic focuses, "sympathetic arthritis" with synovitis is seen frequently. A therapeutic approach with azithromycine and calcitonine is presented.

Diffusion of hyperpolarized (13) C-metabolites in tumor cell spheroids using real-time NMR spectroscopy

The detection of tumors noninvasively, the characterization of their progression by defined markers and the monitoring of response to treatment are goals of medical imaging techniques. In this article, a method which measures the apparent diffusion coefficients (ADCs) of metabolites using hyperpolarized (13) C diffusion-weighted spectroscopy is presented. A pulse sequence based on the pulsed gradient spin echo (PGSE) was developed that encodes both kinetics and diffusion information. In experiments with MCF-7 human breast cancer cells, we detected an ADC of intracellularly produced lactate of 1.06 ± 0.15 µm(2) /ms, which is about one-half of the value measured with pyruvate in extracellular culture medium. When monitoring tumor cell spheroids during progressive membrane permeabilization with Triton X-100, the ratio of lactate ADC to pyruvate ADC increases as the fraction of dead cells increases. Therefore, (13) C ADC detection can yield sensitive information on changes in membrane permeability and subsequent cell death. Our results suggest that both metabolic label exchange and (13) C ADCs can be acquired simultaneously, and may potentially serve as noninvasive biomarkers for pathological changes in tumor cells.

Next-generation heteronuclear decoupling for high-field biomolecular NMR spectroscopy

Ultra-high-field NMR spectroscopy requires an increased bandwidth for heteronuclear decoupling, especially in biomolecular NMR applications. Composite pulse decoupling cannot provide sufficient bandwidth at practical power levels, and adiabatic pulse decoupling with sufficient bandwidth is compromised by sideband artifacts. A novel low-power, broadband heteronuclear decoupling pulse is presented that generates minimal, ultra-low sidebands. The pulse was derived using optimal control theory and represents a new generation of decoupling pulses free from the constraints of periodic and cyclic sequences. In comparison to currently available state-of-the-art methods this novel pulse provides greatly improved decoupling performance that satisfies the demands of high-field biomolecular NMR spectroscopy.

In vivo measurement of apparent diffusion coefficients of hyperpolarized ¹³C-labeled metabolites

The combination of hyperpolarized MRS with diffusion weighting (dw) allows for determination of the apparent diffusion coefficient (ADC), which is indicative of the intra- or extracellular localization of the metabolite. Here, a slice-selective pulsed-gradient spin echo sequence was implemented to acquire a series of dw spectra from rat muscle in vivo to determine the ADCs of multiple metabolites after a single injection of hyperpolarized [1- ¹³C]pyruvate. An optimal control optimized universal-rotation pulse was used for refocusing to minimize signal loss caused by B1 imperfections. Non-dw spectra were acquired interleaved with the dw spectra and these were used to correct for signal decay during the acquisition as a result of T1 decay, pulse imperfections, flow etc. The data showed that the ADC values for [1- ¹³C]lactate (0.4-0.7 µm² /ms) and [1- ¹³C]alanine (0.4-0.9 µm² /ms) were about a factor of two lower than the ADC of [1- ¹³C]pyruvate (1.1-1.5 µm²/ms). This indicates a more restricted diffusion space for the former two metabolites consistent with lactate and alanine being intracellular. The higher ADC for pyruvate (similar to the proton ADC) reflected that the injected substance was not confined inside the muscle cells but also present extracellular.

In Vivo Metabolic Imaging of [1-13 C]Pyruvate-d3 Hyperpolarized By Reversible Exchange With Parahydrogen

Metabolic magnetic resonance imaging (MRI) using hyperpolarized (HP) pyruvate is becoming a non-invasive technique for diagnosing, staging, and monitoring response to treatment in cancer and other diseases. The clinically established method for producing HP pyruvate, dissolution dynamic nuclear polarization, however, is rather complex and slow. Signal Amplification By Reversible Exchange (SABRE) is an ultra-fast and low-cost method based on fast chemical exchange. Here, for the first time, we demonstrate not only in vivo utility, but also metabolic MRI with SABRE. We present a novel routine to produce aqueous HP [1-13 C]pyruvate-d3 for injection in 6 minutes. The injected solution was sterile, non-toxic, pH neutral and contained ≈30 mM [1-13 C]pyruvate-d3 polarized to ≈11 % (residual 250 mM methanol and 20 μM catalyst). It was obtained by rapid solvent evaporation and metal filtering, which we detail in this manuscript. This achievement makes HP pyruvate MRI available to a wide biomedical community for fast metabolic imaging of living organisms.

Autosomal dominant spastic paraplegia with anticipation maps to a 4-cM interval on chromosome 2p21-p24 in a large German family

Autosomal dominant familial spastic paraplegias (AD-FSP) are a group of genetically heterogeneous diseases characterised by a progressive spasticity of the lower limbs. Three loci have already been identified by genetic linkage studies on chromosomes 2p, 14q and 15q. Here we present linkage data from a large German family displaying AD-FSP with anticipation which confirms the existence of the FSP2 locus on chromosome 2p. The recombination events observed in our family define the critical region for the FSP2 gene to be within a 4-cM interval, flanked by markers D2S400 and D2S367. Moreover, clinical data from our family show evidence of anticipation, a phenomenon caused by trinucleotide expansion in several other neurodegenerative diseases.

Spatially resolved quantification of gadolinium(III)-based magnetic resonance agents in tissue by MALDI imaging mass spectrometry after in vivo MRI

Gadolinium(III)-based contrast agents improve the sensitivity and specificity of magnetic resonance imaging (MRI), especially when targeted contrast agents are applied. Because of nonlinear correlation between the contrast agent concentration in tissue and the MRI signal obtained in vivo, quantification of certain biological or pathophysiological processes by MRI remains a challenge. Up to now, no technology has been able to provide a spatially resolved quantification of MRI agents directly within the tissue, which would allow a more precise verification of in vivo imaging results. MALDI imaging mass spectrometry for spatially resolved in situ quantification of gadolinium(III) agents, in correlation to in vivo MRI, were evaluated. Enhanced kinetics of Gadofluorine M were determined dynamically over time in a mouse model of myocardial infarction. MALDI imaging was able to corroborate the in vivo imaging MRI signals and enabled in situ quantification of the gadolinium probe with high spatial resolution.

[Vertebral manifestation of chronic recurrent multifocal osteomyelitis (CRMO)]

Chronic recurrent multifocal osteomyelitis (CRMO) is a systemic osteo-articular disease that is characterized by a sterile, primarily chronic osteomyelitis with various distribution patterns of the individual lesions. In this article, we describe the "axial type" with predominant involvement of the spine, which represents 13 of our 41 CRMO cases of different age groups. The important element of its diagnosis is the typical lympho-plasmacellular spondylitis that can be detected and staged by scintigraphy, MRI and conventional radiography. Potentially affected are all vertebrae from the mid-cervical spine to the sacrum. One or several segments can be involved, sometimes as transient inflammatory edema, sometimes as "migratory spondylitis" or "saltatory spondylitis", but also as chronic sclerosing type with early radiographically detectable manifestation. Vertebral deformity due to compression and total collapse (vertebra plana) are rare. A complicated course with patulous perivertebral edema can lead to concomitant symptomatic inflammatory changes in adjacent regions and organs. In the course of CRMO, spondylodiscitis only develops as secondary destruction following the spondylitis. This can help to differentiate spondyloarthropathies from CRMO that is initially detected as primary lesion in the spine. While CRMO generally has a good prognosis, its radiological differentiation from rheumatologic conditions plays an important role.

Hyperpolarized 13C Diffusion MRS of Co-Polarized Pyruvate and Fumarate to Measure Lactate Export and Necrosis

Background: Non-invasive tumor characterization and monitoring are among the key goals of medical imaging. Using hyperpolarized ¹³C-labelled metabolic probes fast metabolic pathways can be probed in real-time, providing new opportunities for tumor characterization. In this in vitro study, we investigated whether measurement of apparent diffusion coefficient (ADC) measurements and magnetic resonance spectroscopy (MRS) of co-polarized ¹³C-labeled pyruvic acid and fumaric acid can non-invasively detect both necrosis and changes in lactate export, which are parameters indicative of tumor aggressiveness. Methods:¹³C-labeled pyruvic acid and fumaric acid were co-polarized in a preclinical hyperpolarizer and the dissolved compounds were added to prepared samples of 8932 pancreatic cancer and MCF-7 breast carcinoma cells. Extracellular lactate concentrations and cell viability were measured in separate assays. Results: The mean ratios of the ADC values of lactate and pyruvate (ADC_lac/ADC_pyr) between MCF-7 (0.533 ± 0.015, n = 3) and 8932 pancreatic cancer cells (0.744 ± 0.064, n = 3) showed a statistically significant difference (p = 0.048). 8932 cells had higher extracellular lactate concentrations in the extracellular medium (22.97 ± 2.53 ng/µl) compared with MCF-7 cells (7.52 ± 0.59 ng/µl; p < 0.001). Fumarate-to-malate conversion was only detectable in necrotic cells, thereby allowing clear differentiation between necrotic and viable cells. Conclusion: We provide evidence that MRS of hyperpolarized ¹³C-labelled pyruvic acid and fumaric acid, with their respective conversions to lactate and malate, are useful for characterization of necrosis and lactate efflux in tumor cells.

Chemical shift correlations from hyperpolarized NMR using a single SHOT

A significant challenge in realizing the promise of the dissolution dynamic nuclear polarization technique for signal enhancement in high-resolution NMR lies in the nonrenewability of the hyperpolarized spin state. This property prevents the application of traditional two-dimensional correlation spectroscopy, which relies on regeneration of spin polarization before each successive increment of the indirect dimension. Since correlation spectroscopy is one of the most important approaches for the identification and structural characterization of molecules by NMR, it is important to find easily applicable methods that circumvent this problem. Here, we introduce the application of scaling of heteronuclear couplings by optimal tracking (SHOT) to achieve this goal. SHOT decoupling pulses have been numerically optimized on the basis of optimal control algorithms to obtain chemical shift correlations in C-H groups, either by acquiring a single one-dimensional (13)C spectrum with (1)H off-resonance decoupling or vice versa. Vanillin, which contains a number of functional groups, was used as a test molecule, allowing the demonstration of SHOT decoupling tailored toward simplified and accurate data analysis. This strategy was demonstrated for two cases: First, a linear response to chemical shift offset in the correlated dimension was optimized. Second, a pulse with alternating linear responses in the correlated dimension was chosen as a goal to increase the sensitivity of the decoupling response to the chemical shift offset. In these measurements, error ranges of ±0.03 ppm for the indirectly determined (1)H chemical shifts and of ±0.4 ppm for the indirectly determined (13)C chemical shifts were found. In all cases, we show that chemical shift correlations can be obtained from information contained in a single scan, which maximizes the ratio of signal to stochastic noise. Furthermore, a comprehensive discussion of the robustness of the method toward nonideal conditions is included based on experimental and simulated data. Unique features of this technique include the abilities to control the accuracy of chemical shift determination in spectral regions of interest and to acquire such chemical shift correlations rapidly-the latter being of interest for potential application in real-time spectroscopy.

[Chronic recurrent multifocal osteomyelitis (CRMO)]

Chronic recurrent multifocal osteomyelitis (CRMO) is an unusual clinical entity. More than 200 cases are described in the literature and it is presented here with special reference to its radiological aspects. It is an acquired disease of the skeleton which occurs predominantly during childhood and adolescence. About ten per cent of cases begin in early or, rarely, in later adult life. This variant is described here for the first time and is discussed as "adult CRMO". The underlying pathology is a bland, predominantly lympho-plasma cellular osteomyelitis which is self-limiting and leads to bone sclerosis (Garrè). It probably involves an abnormal immune process which follows an infection but remains clinically latent and remains aseptic and sterile. In a quarter of cases there is an association with pustulosis palmo-plantaris and its relationship with psoriatic arthropathy is discussed. The clinical, histopathological and imaging features (radiological and particularly MRT) and the bone changes are described. This provides a spectrum of symptoms; the radiological differential diagnosis and the relationship with hyperostotic spondyloarthroses during adult life are discussed. The relationship between CRMO, the SAPHO syndrome and acquired hyperostosis syndrome are analysed.