Supplementation-induced change in muscle carnosine is paralleled by changes in muscle metabolism, protein glycation and reactive carbonyl species sequestering.

Carnosine is a performance-enhancing food supplement with a potential to modulate muscle energy metabolism and toxic metabolites disposal. In this study we explored interrelations between carnosine supplementation (2 g/day, 12 weeks) induced effects on carnosine muscle loading and parallel changes in (i) muscle energy metabolism, (ii) serum albumin glycation and (iii) reactive carbonyl species sequestering in twelve (M/F=10/2) sedentary, overweight-to-obese (BMI: 30.0+/-2.7 kg/m2) adults (40.1+/-6.2 years). Muscle carnosine concentration (Proton Magnetic Resonance Spectroscopy; 1H-MRS), dynamics of muscle energy metabolism (Phosphorus Magnetic Resonance Spectroscopy; 31P-MRS), body composition (Magnetic Resonance Imaging; MRI), resting energy expenditure (indirect calorimetry), glucose tolerance (oGTT), habitual physical activity (accelerometers), serum carnosine and carnosinase-1 content/activity (ELISA), albumin glycation, urinary carnosine and carnosine-propanal concentration (mass spectrometry) were measured. Supplementation-induced increase in muscle carnosine was paralleled by improved dynamics of muscle post-exercise phosphocreatine recovery, decreased serum albumin glycation and enhanced urinary carnosine-propanal excretion (all p<0.05). Magnitude of supplementation-induced muscle carnosine accumulation was higher in individuals with lower baseline muscle carnosine, who had lower BMI, higher physical activity level, lower resting intramuscular pH, but similar muscle mass and dietary protein preference. Level of supplementation-induced increase in muscle carnosine correlated with reduction of protein glycation, increase in reactive carbonyl species sequestering, and acceleration of muscle post-exercise phosphocreatine recovery.

Navigator based respiratory gating during acquisition and preparation phases for proton liver spectroscopy at 3 T.

Proton magnetic resonance spectroscopy ((1)H MRS) enables the non-invasive investigation of the human liver; however, because of technical difficulties it is not regularly used for diagnosis of liver diseases in clinical routine. Breathing motion is one of the major challenges, as it decreases spectral quality and leads to misplacement of the spectroscopic voxel. To overcome this problem, real-time navigator gating for spectral acquisition and preparation steps (B0 shimming, water frequency determination, receiver gain optimization, and water suppression) combined with short TE , optimized first order projection based B0 shimming, water suppression, and inner-volume saturated point resolved spectroscopy (PRESS) at 3 T is suggested. Simultaneous lipid and trimethylamine quantification is demonstrated by means of phantom, volunteer, and representative patient measurements. Precise localization of the voxel despite respiratory motion, increased spectral quality (higher signal-to-noise ratio and reduced linewidth) compared with measurements without respiratory gating, and the possibility of acquiring data without additional subject instructions regarding breathing enable robust and accurate liver (1)H MRS measurements with this novel acquisition protocol.

Stereotactic vacuum-assisted breast biopsy: our experience and comparison with stereotactic automated needle biopsy.

OBJECTIVES: To evaluate and compare the outcome of stereotactically guided percutaneous, directional, vacuum-assisted breast biopsy (VAB) with the outcome of those performed with 14-gauge automated gun. METHODS: Between January 2008 and January 2011, altogether 257 stereotactic biopsies were performed in our institute; 193 with the 14-gauge automated needle and 64 with a directional, vacuum-assisted instrument. Patients with malignant or high risk lesions were encouraged to undergo an excisional biopsy. We evaluated and compared concordance between the biopsy results and subsequent examinations (surgical excision or follow up) for both methods. RESULTS: VAB demonstrated 57 (89 %) benign lesions, 2 (3 %) high risk and 5 (8 %) malignant lesions. We obtained post-bioptic mammographic or histological evaluation for altogether 51 lesions, with one (12.5 %) false negative case, one case of underestimation of borderline lesion, and no false positive cases. Clusters of microcalcifiation were completely removed in 18 lesions (28 %). CONCLUSION: Vacuum-assisted biopsy outperformed the 14-gauge automated needle biopsy with a lower disease underestimation, sensitivity and false-negative rates; however these differences were not statistically significant due to small data files and relatively small number of identified malignant lesions in the vacuum-assisted biopsy group.VAB completely removed significantly more clusters of microcalcifications in comparison to the automated needle biopsy, which significantly reduced the need for surgery in benign lesions (Tab. 7, Fig. 3, Ref. 32).

The role of dynamic contrast-enhanced MRI in differentiation of local recurrence and residual soft-tissue tumor versus post-treatment changes.

OBJECTIVES: To evaluate the reliability of dynamic contrast-enhanced MRI in the diagnosis of local recurrence of malignant soft-tissue tumors after receiving treatment. METHODS: From March 2002 till December 2009 we performed dynamic contrast enhanced MRI in 95 patients with soft-tissue tumor after receiving treatment (surgery, radiotherapy, chemotherapy). Patients were classified according to five types of TIC. RESULTS: The recurrent disease was suspected in 47 patients and the biopsy was recommended. In 8 cases (TIC II), the biopsy was performed due to long-term post-treatment changes. Histological results proved STT recurrence in 45 patients; in 10 patients (8 with TIC II), biopsy revealed hypervascular granulation tissue, florid inflammation and reactive changes. The sensitivity for dynamic contrast-enhanced MR examination was 100 %, specificity 80 %, positive predictive value (PPV) 95.7 % and negative predictive value (NPV) 100 %. CONCLUSION: Our results indicate that TICs III, IV and V raise high suspicion of local tumor recurrence and require percutaneous imaging-guided biopsy. TIC of type II usually represents a pseudomass and the biopsy should be performed only in selected cases with increased risk of recurrent disease based on multidisciplinary approach. On the basis of literature review as well as our experiences we created a reliable algorithm proposed for diagnosing the residual or recurrent soft-tissue tumors (Tab. 2, Fig. 6, Ref. 20).

Fully adiabatic 31P 2D-CSI with reduced chemical shift displacement error at 7 T--GOIA-1D-ISIS/2D-CSI.

A fully adiabatic phosphorus (31P) two-dimensional (2D) chemical shift spectroscopic imaging sequence with reduced chemical shift displacement error for 7 T, based on 1D-image-selected in vivo spectroscopy, combined with 2D-chemical shift spectroscopic imaging selection, was developed. Slice-selective excitation was achieved by a spatially selective broadband GOIA-W(16,4) inversion pulse with an interleaved subtraction scheme before nonselective adiabatic excitation, and followed by 2D phase encoding. The use of GOIA-W(16,4) pulses (bandwidth 4.3-21.6 kHz for 10-50 mm slices) reduced the chemical shift displacement error in the slice direction ∼1.5-7.7 fold, compared to conventional 2D-chemical shift spectroscopic imaging with Sinc3 selective pulses (2.8 kHz). This reduction was experimentally demonstrated with measurements of an MR spectroscopy localization phantom and with experimental evaluation of pulse profiles. In vivo experiments in clinically acceptable measurement times were demonstrated in the calf muscle (nominal voxel volume, 5.65 ml in 6 min 53 s), brain (10 ml, 6 min 32 s), and liver (8.33 ml, 8 min 14 s) of healthy volunteers at 7 T. High reproducibility was found in the calf muscle at 7 T. In combination with adiabatic excitation, this sequence is insensitive to the B1 inhomogeneities associated with surface coils. This sequence, which is termed GOIA-1D-ISIS/2D-CSI (goISICS), has the potential to be applied in both clinical research and in the clinical routine.

Digital and manual cephalometric analysis.

OBJECTIVES: To compare the manual and digital cephalometric analyses and to research a new procedure of analog cephalogram digitalization. METHODS: 40 repeated measurements were used to evaluate the reproducibility and reliability of both methods. The analog x-ray was CHIRALUX2, the digital camera used was Canon PowerShot G5 and the digital tracing was done by Dolphin imaging version 10. The sample dispersion has been evaluated for each of the monitored cephalometric variables (SNA, SNB, ANB, PP/ML, inter-incisal angle and Wits). The difference of sample dispersion was tested (Morgan-Pitman). Four doctors processed 100 random analog cephalograms in total and evaluated them in a way established by Bland and Altman. RESULTS AND CONCLUSION: Validity and reproducibility of analyses carried out manually and digitally is in high mutual correlation and therefore the software analysis can fully substitute the manual method. The dispersion of values in repeated measurements was higher in manual method and therefore we consider the digital method more accurate (Fig. 4, Tab. 1, Ref. 15). Full Text (Free, PDF) www.bmj.sk.

Digitalization in radiology--6 years in the St. Elisabeth Oncology Institute.

OBJECTIVES: To determine advantages and specific problems of film-free digital hospital focused on radiology department. BACKGROUND: In the St. Elisabeth Oncology Institute in Bratislava we have more than 6-year experience with digital modalities and the PACS system. During this period many difficulties occurred and are expected to rise with an increasing number of digital modalities. METHODS: Statistical evaluation of a 6-year period in numerous graphs and schemes. RESULTS: The amount of data can be seen in graphs, which show the amount of examinations and data volume from different modalities for specific time period to October 2007 and present volumes and increase of data amount in megabytes (MB) in the last 6 years. CONCLUSION: Despite of systematic capacity increase it is a long-term archiving and economical problem. It is crucial to solve the daily amount of data, backup copies, type of archiving media, and priority of data accessibility (Tab. 1, Fig. 5, Ref. 9). Full Text (Free, PDF) www.bmj.sk.