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Phenotypic diversity in bacterial flagella-induced motility leads to complex collective swimming patterns, appearing as traveling bands with transient locally enhanced cell densities. Traveling bands are known to be a bacterial chemotactic response to self-generated nutrient gradients during growth in resource-limited microenvironments. In this work, we studied different parameters of Escherichia coli (E. coli) collective migration, in particular the quantity of bacteria introduced initially in a microfluidic chip (inoculum size) and their exposure to antibiotics (ampicillin, ciprofloxacin, and gentamicin). We developed a hybrid polymer-glass chip with an intermediate optical adhesive layer featuring the microfluidic channel, enabling high-content imaging of the migration dynamics in a single bacterial layer, i.e., bacteria are confined in a quasi-2D space that is fully observable with a high-magnification microscope objective. On-chip bacterial motility and traveling band analysis was performed based on individual bacterial trajectories by means of custom-developed algorithms. Quantifications of swimming speed, tumble bias and effective diffusion properties allowed the assessment of phenotypic heterogeneity, resulting in variations in transient cell density distributions and swimming performance. We found that incubation of isogeneic E. coli with different inoculum sizes eventually generated different swimming phenotype distributions. Interestingly, incubation with antimicrobials promoted bacterial chemotaxis in specific cases, despite growth inhibition. Moreover, E. coli filamentation in the presence of antibiotics was assessed, and the impact on motility was evaluated. We propose that the observation of traveling bands can be explored as an alternative for fast antimicrobial susceptibility testing. [ABSTRACT FROM AUTHOR]

Assays focusing on emerging biological phenomena in an animal's life can be performed during embryogenesis. While the embryo of Caenorhabditis elegans has been extensively studied, its biomechanical properties are largely unknown. Here, we demonstrate that cellular force microscopy (CFM), a recently developed technique that combines micro-indentation with high resolution force sensing approaching that of atomic force microscopy, can be successfully applied to C. elegans embryos. We performed, for the first time, a quantitative study of the mechanical properties of the eggshell of living C. elegans embryos and demonstrate the capability of the system to detect alterations of its mechanical parameters and shell defects upon chemical treatments. In addition to investigating natural eggshells, we applied different eggshell treatments, i.e., exposure to sodium hypochlorite and chitinase solutions, respectively, that selectively modified the multilayer eggshell structure, in order to evaluate the impact of the different layers on the mechanical integrity of the embryo. Finite element method simulations based on a simple embryo model were used to extract characteristic eggshell parameters from the experimental micro-indentation force-displacement curves. We found a strong correlation between the severity of the chemical treatment and the rigidity of the shell. Furthermore, our results showed, in contrast to previous assumptions, that short bleach treatments not only selectively remove the outermost vitelline layer of the eggshell, but also significantly degenerate the underlying chitin layer, which is primarily responsible for the mechanical stability of the egg. A tough egg to crack: By carefully probing the surface of Caenorhabiditis elegans eggs, researchers were able to quantify the physical strength of the various layers shielding the developing embryo. This worm species is a popular laboratory model, and the general structure of its embryonic eggshell has been closely analyzed. Little is known about the shell's mechanical characteristics, however, and researchers led by Roger Krenger of the EPFL and Jan Burri of the ETH in Switzerland employed a technique called cellular force microscopy (CFM) to address this question. CFM entails precisely prodding biological specimens with a microscale probe and collecting measurements of the resulting force. This allowed them to not only measure the rigidity of the intact egg, but also to assess the structural contributions of individual shell layers by performing measurements after using chemical treatments to remove these various strata. [ABSTRACT FROM AUTHOR]

Objectives: To evaluate objective and subjective image quality of a noise-optimized virtual monoenergetic imaging (VMI+) reconstruction technique in dual-energy computed tomography (DECT) angiography prior to transcatheter aortic valve replacement (TAVR).Methods: Datasets of 47 patients (35 men; 64.1 ± 10.9 years) who underwent DECT angiography of heart and vascular access prior to TAVR were reconstructed with standard linear blending (F_0.5), VMI+, and traditional monoenergetic (VMI) algorithms in 10-keV intervals from 40-100 keV. Signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR) of 564 arterial segments were evaluated. Subjective analysis was rated by three blinded observers using a Likert scale.Results: Mean SNR and CNR were highest in 40 keV VMI+ series (SNR, 27.8 ± 13.0; CNR, 26.3 ± 12.7), significantly (all p < 0.001) superior to all VMI series, which showed highest values at 70 keV (SNR, 18.5 ± 7.6; CNR, 16.0 ± 7.4), as well as linearly-blended F_0.5 series (SNR, 16.8 ± 7.3; CNR, 13.6 ± 6.9). Highest subjective image quality scores were observed for 40, 50, and 60 keV VMI+ reconstructions (all p > 0.05), significantly superior to all VMI and standard linearly-blended images (all p < 0.01).Conclusions: Low-keV VMI+ reconstructions significantly increase CNR and SNR compared to VMI and standard linear-blending image reconstruction and improve subjective image quality in preprocedural DECT angiography in the context of TAVR planning.Key Points: • VMI+ combines increased contrast with reduced image noise. • VMI+ shows substantially less image noise than traditional VMI. • 40-keV reconstructions show highest SNR/CNR of the aortic and iliofemoral access route. • Observers overall prefer 60 keV VMI+ images. • VMI+ DECT imaging helps improve image quality for TAVR planning. [ABSTRACT FROM AUTHOR]

Objectives: To compare quantitative image quality parameters in abdominal dual-energy computed tomography angiography (DE-CTA) using an advanced image-based (Mono+) reconstruction algorithm for virtual monoenergetic imaging and standard DE-CTA.Methods: Fifty-five patients (36 men; mean age, 64.2 ± 12.7 years) who underwent abdominal DE-CTA were retrospectively included. Mono + images were reconstructed at 40, 50, 60, 70, 80, 90 and 100 keV levels and as standard linearly blended M_0.6 images (60 % 100 kV, 40 % 140 kV). The contrast-to-noise ratio (CNR) and signal-to-noise ratio (SNR) of the common hepatic (CHA), splenic (SA), superior mesenteric (SMA) and left renal arteries (LRA) were objectively measured.Results: Mono+ DE-CTA series showed a statistically superior CNR for 40, 50, 60, 70 and 80 keV (P < 0.031) compared to M_0.6 images for all investigated arteries except SMA at 80 keV (P = 0.08). CNR at 40 keV revealed a mean relative increase of 287.7 % compared to linearly blended images among all assessed arteries (P < 0.001). SNR of Mono+ images was consistently significantly higher at 40, 50, 60 and 70 keV compared to M_0.6 for CHA and SA (P < 0.009).Conclusions: Compared to linearly blended images, Mono+ reconstructions at low keV levels of abdominal DE-CTA datasets significantly improve quantitative image quality.Key Points: • Mono+ combines increased attenuation with reduced image noise compared to standard DE-CTA. • Mono+ shows superior contrast-to-noise ratios at low keV compared to linearly-blended images. • Contrast-to-noise ratio in monoenergetic DE-CTA peaks at 40 keV. • Mono+ reconstructions significantly improve quantitative image quality at low keV levels. [ABSTRACT FROM AUTHOR]

Purpose: To evaluate feasibility of measuring parenchymal blood volume (PBV) of malignant hepatic tumours using C-arm CT, test the changes in PBV following repeated transarterial chemoembolization (TACE) and correlate these changes with the change in tumour size in MRI.Methods: 111 patients with liver malignancy were included. Patients underwent MRI and TACE in a 4- to 6-week interval. During intervention C-arm CT was performed. Images were post-processed to generate PBV maps. Blood volume data in C-arm CT and change in size in MRI were evaluated. The correlation between PBV and size was tested using Spearman rank test.Results: Pre-interventional PBV maps showed a mean blood volume of 84.5 ml/1000 ml ± 62.0, follow-up PBV maps after multiple TACE demonstrated 61.1 ml/1000 ml ± 57.5. The change in PBV was statistically significant (p = 0.02). Patients with initial tumour blood volume >100 ml/1000 ml dropped 7.1% in size and 47.2% in blood volume; 50-100 ml/1000 ml dropped 4.6% in size and 25.7% in blood volume; and <50 ml/1000 ml decreased 2.8% in size and increased 82.2% in blood volume.Conclusion: PBV measurement of malignant liver tumours using C-arm CT is feasible. Following TACE PBV decreased significantly. Patients with low initial PBV show low local response rates and further increase in blood volume, whereas high initial tumour PBV showed better response to TACE.Key Points: Parenchymal blood volume assessment of malignant hepatic lesions using C-arm CT is feasible. The parenchymal blood volume is reduced significantly following transarterial chemoembolization. Parenchymal blood volume can monitor the response of tumours after transarterial chemoembolization. Although not significant, high initial parenchymal blood volume yields better response to TACE. [ABSTRACT FROM AUTHOR]

Purpose: To assess the scope and determining risk factors related to the development of pneumothorax throughout CT-guided biopsy of pulmonary lesions in coaxial and non-coaxial techniques and the outcome of its management.Materials and Methods: The study included CT-guided percutaneous lung biopsies in 650 consecutive patients (407 males, 243 females; mean age 54.6 years, SD 5.2) from November 2008 to June 2013 in a retrospective design. Patients were classified according to lung biopsy technique into coaxial group (318 lesions) and non-coaxial group (332 lesions). Exclusion criteria for biopsy were lesions <5 mm in diameter, uncorrectable coagulopathy, positive-pressure ventilation, severe respiratory compromise, pulmonary arterial hypertension, or refusal of the procedure. Risk factors related to the occurrence of pneumothorax were classified into: (a) Technical risk factors, (b) patient-related risk factors, and (c) lesion-associated risk factors. Radiological assessments were performed by two radiologists in consensus. Mann-Whitney U test and Fisher's exact tests were used for statistical analysis. p values <0.05 were considered statistically significant.Results: The incidence of pneumothorax complicating CT-guided lung biopsy was less in the non-coaxial group (23.2 %, 77 out of 332) than the coaxial group (27 %, 86 out of 318). However, the difference in incidence between both groups was statistically insignificant (p = 0.14). Significant risk factors for the development of pneumothorax in both groups were emphysema (p < 0.001 in both groups), traversing a fissure with the biopsy needle (p value 0.005 in non-coaxial group and 0.001 in coaxial group), small lesion, less than 2 cm in diameter (p value of 0.02 in both groups), location of the lesion in the basal or mid sections of the lung (p = 0.003 and <0.001 in non-coaxial and coaxial groups, respectively), and increased needle track path within the lung tissue of more than 2.5 cm (p = 0.01 in both groups). The incidence of pneumothorax in the non-coaxial group was significantly correlated to the number of specimens obtained (p = 0.006). This factor was statistically insignificant in the coaxial group (p = 0.45). The biopsy yield was more diagnostic and conclusive in the coaxial group in comparison to the non-coaxial group (p = 0.008). Simultaneous incidence of pneumothorax and pulmonary hemorrhage was 27.3 % (21/77) in non-coaxial group and in 30.2 % (26/86) in coaxial group. Conservative management was sufficient for treatment of 91 out of 101 patients of pneumothorax in both groups (90.1 %). Manual evacuation of pneumothorax was efficient in 44/51 patients (86.3 %) in both groups and intercostal chest tube was applied after failure of manual evacuation (7 patients: 13.7 %), from which one patient developed a persistent air leakage necessitating pleurodesis.Conclusion: Pneumothorax complicating CT-guided core biopsy of pulmonary lesions, showed the insignificant difference between coaxial and non-coaxial techniques. However, both techniques have the same significant risk factors including small and basal lesions, increased lesion's depth from pleural surface, and increased length of aerated lung parenchyma crossed by biopsy needle and passing through pulmonary fissures in the needle tract. [ABSTRACT FROM AUTHOR]

In 2011, Konnopka et al. (Eur J Health Econ 12:345-352, 2011) published a top-down cost of illness study on the health burden, and direct and indirect costs of morbidity and mortality attributable to excess weight (BMI ≥25 kg/m(2)) in Germany in 2002. The objective of the current study was to update the 2002 estimates to the year 2008. To simplify comparisons, we closely followed the methods and assumptions of the original study, using 2008 data for most input parameters (e.g. prevalence, mortality, resource use, costs). Excess weight related deaths increased by 31% (from 36,653 to 47,964) and associated years of potential life lost (from 428,093 to 588,237) and quality adjusted life years lost (from 367,722 to 505,748) by about 37%, respectively. Excess weight caused €16,797 million in total costs in 2008 (+70%), of which €8,647 million were direct costs (corresponding to 3.27% of total German health care expenditures in 2008). About 73% (€12,235 million) of total excess weight related costs were attributable to obesity (BMI ≥30 kg/m(2)). The main drivers of direct costs were endocrinological (44%) and cardiovascular (38%) diseases. Indirect costs amounted to €8,150 million in 2008 (+62%), of which about two-thirds were indirect costs from unpaid work. The great majority of indirect costs were due to premature mortality (€5,669 million). The variation of input parameters (univariate sensitivity analyses) resulted in attributable costs between €8,978 million (-47% compared to base case) and €25,060 million (+49%). The marked increase in excess weight related costs can largely be explained by increases in the prevalence of overweight and obesity, and to a lesser extent from increases in resource consumption, as well as increases in (unit) costs and wages (comprising 5.5% inflation). [ABSTRACT FROM AUTHOR]

Objectives: To compare radiation exposure and image quality of second-generation 128-slice dual-source CT (DSCT) coronary angiography (cCTA) protocols. Materials and methods: We retrospectively analyzed data from four groups with 25 patients, each examined by one of the following DSCT cCTA protocols: prospectively ECG-gated high-pitch (group 1) or sequential (group 2) acquisition, retrospectively ECG-gated acquisition in dual-energy (DECT, group 3) or dual-source (group 4) mode. CT dose index volume, dose length product, estimated radiation dose, contrast-to-noise- and signal-to-noise-ratios were compared. Subjective image quality was rated by two observers blinded to the protocols. Results: High-pitch DSCT showed a mean estimated radiation dose of 1.27 ± 0.62 mSv, significantly ( p < 0.01) lower than sequential (2.04 ± 0.94 mSv), dual-energy (3.97 ± 1.29 mSv) or dual-source (8.11 ± 4.95 mSv) acquisition. Image noise showed no statistical difference ( p > 0.91), ranging from 15.2 ± 4.4 (group 2) up to 24.5 ± 22.0 (group 4). Each protocol showed diagnostic image quality in at least 98.1 % of evaluated coronary segments without significant differences ( p > 0.05). Conclusions: Prospectively ECG-gated DSCT protocols enable cCTA with significant dose reduction and consistently diagnostic image quality. In patients requiring retrospectively ECG-gated DSCT for functional analysis or due to arrhythmia, dual-energy mode should be preferred over dual-source mode as it significantly decreases estimated dose without compromising image quality. [ABSTRACT FROM AUTHOR]

Objectives: To define optimal keV settings for advanced monoenergetic (Mono+) dual-energy computed tomography (DECT) in patients with head and neck squamous cell carcinoma (SCC).Methods: DECT data of 44 patients (34 men, mean age 55.5 ± 16.0 years) with histopathologically confirmed SCC were reconstructed as 40, 55, 70 keV Mono + and M_0.3 (30 % 80 kV) linearly blended series. Attenuation of tumour, sternocleidomastoid muscle, internal jugular vein, submandibular gland, and noise were measured. Three radiologists with >3 years of experience subjectively assessed image quality, lesion delineation, image sharpness, and noise.Results: The highest lesion attenuation was shown for 40 keV series (248.1 ± 94.1 HU), followed by 55 keV (150.2 ± 55.5 HU; P = 0.001). Contrast-to-noise ratio (CNR) at 40 keV (19.09 ± 13.84) was significantly superior to all other reconstructions (55 keV, 10.25 ± 9.11; 70 keV, 7.68 ± 6.31; M_0.3, 5.49 ± 3.28; all P < 0.005). Subjective image quality was highest for 55 keV images (4.53; κ = 0.38, P = 0.003), followed by 40 keV (4.14; κ = 0.43, P < 0.001) and 70 keV reconstructions (4.06; κ = 0.32, P = 0.005), all superior (P < 0.004) to linear blending M_0.3 (3.81; κ = 0.280, P = 0.056).Conclusions: Mono + DECT at low keV levels significantly improves CNR and subjective image quality in patients with head and neck SCC, as tumour CNR peaks at 40 keV, and 55 keV images are preferred by observers.Key Points: • Mono + DECT combines increased contrast with reduced image noise, unlike linearly blended images. • Mono + DECT imaging allows for superior CNR and subjective image quality. • Head and neck tumour contrast-to-noise ratio peaks at 40 keV. • 55 keV images are preferred over all other series by observers. [ABSTRACT FROM AUTHOR]

Purpose: This study was done to investigate the dynamic changes of the aortic root during systole and diastole in patients with coronary artery calcification (CAC) using dual-source computed tomography (DSCT). Materials and methods: We retrospectively analysed 77 consecutive patients who underwent calcium-scoring and angiographic cardiac DSCT. The long- and short-axis dimensions, axis areas of the aortic annulus, sinotubular junction and ascending aorta at the level of the pulmonary trunk in diastole and systole were measured. Average dimensions and relative areal changes between diastole and systole (%RA) of aortic annulus, sinotubular junction and ascending aorta were compared. Results: Systolic and diastolic long- and short-axis dimensions of the aortic annulus in patients with CAC ( n = 44) demonstrated statistically significant differences (27.00 ± 2.84 mm vs. 28.04 ± 2.62 mm; P < 0.001; 21.78 ± 2.55 mm vs. 20.88 ± 2.31 mm; P < 0.001), while differences in average diameters and areas of the aortic annulus were nonsignificant ( P > 0.586). Systolic and diastolic axial areas of the sinotubular junction in patients with CAC demonstrated significant differences (7.21 ± 1.80 cm vs. 6.92 ± 1.75 cm; P < 0.001). The %RA of the ascending aorta in patients with severe CAC (CAC score >400; n = 15) was significantly reduced compared to patients with minimal-to-moderate CAC (CAC score <400; n = 29; 4.77 ± 2.88 vs. 7.51 ± 3.81, P = 0.014). Conclusions: In comparison with patients without CAC, the long- and short-axis dimensions of the aortic annulus and areas of the sinotubular junction show significant differences during the cardiac cycle in patients with CAC. The presence of severe CAC significantly influences the flexibility of the wall of the ascending aorta. [ABSTRACT FROM AUTHOR]

Introduction: To investigate low-tube-voltage 80-kVp computed tomography (CT) of head and neck primary and recurrent squamous cell carcinoma (SCC) regarding objective and subjective image quality. Methods: We retrospectively evaluated 65 patients (47 male, 18 female; mean age: 62.1 years) who underwent head and neck dual-energy CT (DECT) due to biopsy-proven primary ( n = 50) or recurrent ( n = 15) SCC. Eighty peak kilovoltage and standard blended 120-kVp images were compared. Attenuation and noise of malignancy and various soft tissue structures were measured. Tumor signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR) were calculated. Subjective image quality was rated by three reviewers using 5-point grading scales regarding overall image quality, lesion delineation, image sharpness, and image noise. Radiation dose was assessed as CT dose index volume (CTDI). Interobserver agreement was calculated using intraclass correlation coefficient (ICC). Results: Mean tumor attenuation (153.8 Hounsfield unit (HU) vs. 97.1 HU), SNR (10.7 vs. 8.3), CNR (8.1 vs. 4.8), and subjective tumor delineation (score, 4.46 vs. 4.13) were significantly increased (all P < 0.001) with 80-kVp acquisition compared to standard blended 120-kVp images. Noise of all measured structures was increased in 80-kVp acquisition ( P < 0.001). Overall interobserver agreement was good (ICC, 0.86; 95 % confidence intervals: 0.82-0.89). CTDI was reduced by 48.7 % with 80-kVp acquisition compared to standard DECT (4.85 ± 0.51 vs. 9.94 ± 0.81 mGy cm, P < 0.001). Conclusions: Head and neck CT with low-tube-voltage 80-kVp acquisition provides increased tumor delineation, SNR, and CNR for CT imaging of primary and recurrent SCC compared to standard 120-kVp acquisition with an accompanying significant reduction of radiation exposure. [ABSTRACT FROM AUTHOR]

Objectives: To evaluate quantitative dual-energy computed tomography (DECT) for phantomless analysis of cancellous bone mineral density (BMD) of vertebral pedicles and to assess the correlation with pedicle screw pull-out strength. Methods: Twenty-nine thoracic and lumbar vertebrae from cadaver specimens were examined with DECT. Using dedicated post-processing software, a pedicle screw vector was mapped (R1, intrapedicular segment of the pedicle vector; R2, intermediate segment; R3, intracorporal segment; global, all segments) and BMD was calculated. To invasively evaluate pedicle stability, pedicle screws were drilled through both pedicles and left pedicle screw pull-out strength was measured. Resulting values were correlated using the paired t test and Pearson's linear correlation. Results: Average pedicle screw vector BMD (R1, 0.232 g/cm; R2, 0.166 g/cm; R3, 0.173 g/cm; global, 0.236 g/cm) showed significant differences between R1-R2 ( P < 0.002) and R1-R3 ( P < 0.034) segments while comparison of R2-R3 did not reach significance ( P > 0.668). Average screw pull-out strength (639.2 N) showed a far stronger correlation with R1 ( r = 0.80; P < 0.0001) than global BMD ( r = 0.42; P = 0.025), R2 ( r = 0.37; P = 0.048) and R3 ( r = −0.33; P = 0.078) segments. Conclusions: Quantitative DECT allows for phantomless BMD assessment of the vertebral pedicle. BMD of the intrapedicular segment shows a significantly stronger correlation with pedicle screw pull-out strength than other segments. Key points: • Quantitative dual-energy CT enables evaluation of pedicle bone mineral density. • Intrapedicular segments show significant differences regarding bone mineral density. • Pedicle screw pull-out strength correlated strongest with R1 values. • Dual-energy CT may improve preoperative assessment before transpedicular screw fixation. [ABSTRACT FROM AUTHOR]

Objectives: To intra-individually compare single-portal-phase low-tube-voltage (100-kVp) computed tomography (CT) with 120-kVp images for short-term follow-up assessment of CT severity index (CTSI) of acute pancreatitis, interobserver agreement and radiation dose. Methods: We retrospectively analysed 66 patients with acute pancreatitis who underwent initial dual-contrast-phase CT (unenhanced, arterial, portal phase) at admission and short-term (mean interval 11.4 days) follow-up dual-contrast-phase dual-energy CT. The 100-kVp and linearly blended images representing 120-kVp acquisition follow-up CT images were independently evaluated by three radiologists using a modified CTSI assessing pancreatic inflammation, necrosis and extrapancreatic complications. Scores were compared with paired t test and interobserver agreement was evaluated using intraclass correlation coefficients (ICC). Results: Mean CTSI scores on unenhanced, portal- and dual-contrast-phase images were 4.9, 6.1 and 6.2 (120 kVp) and 5.0, 6.0 and 6.1 (100 kVp), respectively. Contrast-enhanced series showed a higher CTSI compared to unenhanced images ( P < 0.05) but no significant differences between single- and dual-contrast-phase series ( P > 0.7). CTSI scores were comparable for 100-kVp and 120-kVp images ( P > 0.05). Interobserver agreement was substantial for all evaluated series and subcategories (ICC 0.67-0.93). DLP of single-portal-phase 100-kVp images was reduced by 41 % compared to 120-kVp images (363.8 versus 615.9 mGy cm). Conclusions: Low-tube-voltage single-phase 100-kVp CT provides sufficient information for follow-up evaluation of acute pancreatitis and significantly reduces radiation exposure. Key Points: • Single-portal-phase CT provides sufficient evaluation for follow-up of acute pancreatitis. • Follow-up CT does not benefit from unenhanced or arterial-phase acquisition. • CT severity index scores are equal for dual-contrast-phase 100-/120-kVp acquisition (P > 0.05). • 100-kVp single-portal-phase follow-up CT of acute pancreatitis significantly reduces radiation exposure. [ABSTRACT FROM AUTHOR]

To compare non-linear and linear blending of cardiac dual-energy computed tomography (DECT) for optimal visualization of late iodine enhancement (LIE) in patients with chronic myocardial infarction (CMI). LIE-DECT data from 20 patients with known CMI were retrospectively analyzed. Images were reconstructed using non-linear blending center and width settings in the range of 0-500. Linear blending was performed with weighting factors 0.8 (80 % 100 kV, 20 % 140 kV), 0.6 and 0.3. 100-/140-kV data and blended images were analyzed. Contrast and percentage signal differences between infarcted and healthy myocardium and the left ventricle blood pool were computed. Statistical analysis was performed using repeated-measures analysis of variance and post hoc t tests. Non-linear blending showed the highest signal differences for all contrasts and analyses. Repeated-measures ANOVA tests confirmed the statistical differences between the investigated blending techniques ( P < 0.01). Paired-samples post hoc t tests confirmed the significance of these results ( P < 0.04). The ideal non-linear blending settings for best demarcation of CMI from healthy myocardium were a center of 65.8 ± 23.2 and a width of 0.0 ± 0.0. Non-linear blending of LIE-DECT improves display of LIE in patients with CMI in comparison with linear blending and non-post-processed image data from 100-/140-kV. [ABSTRACT FROM AUTHOR]

Objective: To investigate the impact of automated attenuation-based tube potential selection on image quality and exposure parameters in polytrauma patients undergoing contrast-enhanced thoraco-abdominal CT. Methods: One hundred patients were examined on a 16-slice device at 120 kV with 190 ref.mAs and automated mA modulation only. Another 100 patients underwent 128-slice CT with automated mA modulation and topogram-based automated tube potential selection (autokV) at 100, 120 or 140 kV. Volume CT dose index (CTDI), dose-length product (DLP), body diameters, noise, signal-to-noise ratio (SNR) and subjective image quality were compared. Results: In the autokV group, 100 kV was automatically selected in 82 patients, 120 kV in 12 patients and 140 kV in 6 patients. Patient diameters increased with higher kV settings. The median CTDI (8.3 vs. 12.4 mGy; −33 %) and DLP (594 vs. 909 mGy cm; −35 %) in the entire autokV group were significantly lower than in the group with fixed 120 kV ( p < 0.05 for both). Image quality remained at a constantly high level at any selected kV level. Conclusion: Topogram-based automated selection of the tube potential allows for significant dose savings in thoraco-abdominal trauma CT while image quality remains at a constantly high level. Key Points: • Automated kV selection in thoraco-abdominal trauma CT results in significant dose savings • Most patients benefit from a 100-kV protocol with relevant DLP reduction • Constantly good image quality is ensured • Image quality benefits from higher kV when arms are positioned downward [ABSTRACT FROM AUTHOR]

Objectives: To evaluate image quality and diagnostic accuracy of selective monoenergetic reconstructions of late iodine enhancement (LIE) dual-energy computed tomography (DECT) for imaging of chronic myocardial infarction (CMI). Methods: Twenty patients with a history of coronary bypass surgery underwent cardiac LIE-DECT and late gadolinium enhancement (LGE) magnetic resonance imaging (MRI). LIE-DECT images were reconstructed as selective monoenergetic spectral images with photon energies of 40, 60, 80, and 100 keV and the standard linear blending setting (M_0.6). Images were assessed for late enhancement, transmural extent, signal characteristics and subjective image quality. Results: Seventy-nine myocardial segments (23 %) showed LGE. LIE-DECT detected 76 lesions. Images obtained at 80 keV and M_0.6 showed a high signal-to-noise ratio (15.9; 15.1), contrast-to-noise ratio (4.2; 4.0) and sensitivity (94.9 %; 92.4 %) while specificity was identical (99.6 %). Differences between these series were not statistically significant. Transmural extent of LIE was overestimated in both series (80 keV: 40 %; M_0.6: 35 %) in comparison to MRI. However, observers preferred 80 keV in 13/20 cases (65 %, κ = 0.634) over M_0.6 (4/20 cases) regarding subjective image quality. Conclusions: Post-processing of LIE-DECT data with selective monoenergetic reconstructions at 80 keV significantly improves subjective image quality while objective image quality shows no significant difference compared to standard linear blending. Key Points: • Late enhancement dual-energy CT allows for detection of chronic myocardial infarction. • Monoenergetic reconstructions at 80 keV significantly improve subjective image quality. • 80 keV and standard linear blending reconstructions show no significant differences. • Extent of CMI detected with LIE-DECT is overestimated compared with MRI. [ABSTRACT FROM AUTHOR]

Enlargement and dysfunction of the right ventricle (RV) is a sign and outcome predictor of many cardiopulmonary diseases. Due to the complex geometry of the RV exact volumetry is cumbersome and time-consuming. We evaluated the performance of prototype software for fully automated RV segmentation and volumetry from cardiac CT data. In 50 retrospectively ECG-gated coronary CT angiography scans the endsystolic (RVVmin) and enddiastolic (RVVmax) volume of the right ventricle was calculated fully automatically by prototype software. Manual slice segmentation by two independent radiologists served as the reference standard. Measurement periods were compared for both methods. RV volumes calculated with the software were in strong agreement with the results from manual slice segmentation (Bland-Altman r = 0.95-0.98; p < 0.001; Lin's correlation Rho = 0.87-0.96, p < 0.001) for RVVmax and RVVmin with excellent interobserver agreement between both radiologists (r = 0.97; p < 0.001). The measurement period was significantly shorter with the software (153 ± 9 s) than with manual slice segmentation (658 ± 211 s). The prototype software demonstrated very good performance in comparison to the reference standard. It promises robust RV volume results and minimizes postprocessing time. [ABSTRACT FROM AUTHOR]

Objectives: To assess whether conservative treatment of pediatric patients with neurogenic detrusor overactivity (NDO) results in lower bladder pressure and increased expected bladder volume (EBV), we investigated the clinical and urodynamic effects of long-term intravesical oxybutynin instillation compared with a standard treatment of oral anticholinergic medication in patients with clean intermittent catheterization (CIC). Methods: A retrospective study was performed including 21 patients suffering from myelomeningocele and NDO. Initially, all patients were treated with oral anticholinergics and CIC. Ten of the 21 patients showed a sufficient response to the treatment and were included in group I (anticholinergics and CIC). The other 11 patients responded poorly to the initial treatment or developed side effects to oral medication. These patients were included in group II and treated with intravesical oxybutynin and CIC. The two groups were compared using clinical, sonographic and urodynamic examinations performed prior to starting treatment and repeated on an annual basis. Changes from baseline were analyzed with the Mann-Whitney U test. Results: Ten patients in group I and 11 in group II were investigated. Two of the 11 patients in group II stopped the treatment. The mean starting age was 8.1 (±6.6) years in group I and 12.5 (±4.5) years in group II. The mean follow-up time was 7.1 (±5.5) years in group I and 3.6 (±1.8) years in group II. Bladder capacity increased from 173 (±99) to 371 (±115) ml in group I and from 245 (±133) to 370 (±156) ml in group II. Six of the 10 patients in group I and 6/9 patients in group II reached normal EBV. Three of the 10 subjects in group I and 6/9 in group II had bladder compliance values >10 ml/cm HO. At final follow-up, the overall rate of urinary tract infections was equal. Social continence was achieved in 6/10 in group I and 7/9 in group II. Altogether, 19/21 patients responded to conservative management. Conclusions: In children with NDO, conservative medical treatment combined with CIC is feasible and provides an improved pattern of bladder function, which could help avoid bladder surgery. [ABSTRACT FROM AUTHOR]

Objective: To compare dose and image quality of 64-slice, first and second generation dual-energy CT (DECT) for CT pulmonary angiography (CTPA).Methods: Totally 120 patients, 30 in each group, underwent CTPA on a first generation (group 1: single-energy, 120 kV/145 mAs; group 2: DE, 140/80 kV, 70/350 mAs) or second generation dual-source DECT device (group 3: DE, 100/Sn140 kV, 120/102 mAs; group 4: DE, 80/Sn140 kV, 202/86 mAs). CTDIvol, DLP, background noise (BN), thorax diameter and attenuation in the pulmonary trunk were compared.Results: Thorax diameter and attenuation in the pulmonary trunk did not differ significantly (p > 0.4 and >0.19) between the groups. Mean CTDIvol and DLP were significantly lower (p < 0.003) in group 4 (6.2 ± 1.6 mGy/170 ± 41 mGycm) compared to group 1 (8.5 ± 2.6 mGy/235 ± 117 mGycm), group 2 (9.2 ± 3.3 mGy/224 ± 122 mGycm) and group 3 (8.7 ± 2.8 mGy/246 ± 86 mGycm). BN was significantly lower (p < 0.0001) in group 4 (12 ± 3 HU) and group 1 (13 ± 6 HU) compared to group 3 and 2 (16 ± 6 HU and 23 ± 9).Conclusion: The use of second generation DECT in 80/Sn140 kV configuration allows for significant dose reduction with image quality similar to 120 kV CTPA. [ABSTRACT FROM AUTHOR]

Objective: To investigate the role of perfusion defect (PD) size on dual energy CT pulmonary blood volume assessment as predictor of right heart strain and patient outcome and its correlation with d-dimer levels in acute pulmonary embolism (PE).Methods: 53 patients with acute PE who underwent DECT pulmonary angiography were retrospectively analyzed. Pulmonary PD size caused by PE was measured on DE iodine maps and quantified absolutely (VolPD) and relatively to the total lung volume (RelPD). Signs of right heart strain (RHS) on CT were determined. Information on d-dimer levels and readmission for recurrent onset of PE and death was collected.Results: D-dimer level was mildly (r = 0.43-0.47) correlated with PD size. Patients with RHS had significantly higher VolPD (215 vs. 73 ml) and RelPD (9.9 vs. 2.9%) than patients without RHS (p < 0.003). There were 2 deaths and 1 readmission due of PE in 18 patients with >5% RelPD, while no such events were found for patients with <5% RelPD.Conclusion: Pulmonary blood volume on DECT in acute PE correlates with RHS and appears to be a predictor of patient outcome in this pilot study. [ABSTRACT FROM AUTHOR]

Purpose: To compare the dose estimates and image quality of Dual Energy CT (DECT), Dual Source CT (DSCT) and 16-slice CT for coronary CT angiography (cCTA).Methods: Sixty-eight patients were examined with 16 - slice MDCT (group 1), 68 patients with DSCT (group 2) and 68 patients using DSCT in dual energy mode (DECT group 3). CT dose index volume, dose length product, effective dose, signal-to-noise, and contrast-to-noise ratio were compared. Subjective image quality was rated by two observers, blinded to technique.Results: The mean estimated radiation dose of all patients investigated on a 16 - slice MDCT was 12 ± 3.59 mSv, for DSCT in single energy 9.8 ± 4.77 mSv and for DECT 4.54 ± 1.87 mSv. Dose for CTA was significantly lower in group 3 compared to group 1 and 2. The image noise was significantly lower in Group 2 in comparison to group 1 and group 3. There was no significant difference in diagnostic image quality comparing DECT and DSCT.Conclusion: cCTA shows better dose levels at both DECT and DSCT compared to 16-slice CT. Further, DECT delivers significantly less dose than regular DSCT or single source single energy cCTA while maintaining diagnostic image quality. [ABSTRACT FROM AUTHOR]

Objective: Computed tomography (CT) of the paranasal sinus is the standard diagnostic tool for a wide range of indications in mostly younger patients. This study aims to assess the image quality of CT of the sinus by using a high-pitch dual-source technique with special regard to the radiation dose.Methods: Examinations were performed on a second-generation dual-source CT with a pitch factor of 3.0 (dual-source mode). Images were compared with those with a pitch factor of 0.9 on the same system (single-source mode) and with those of 16-slice CT. Image quality was evaluated by four blinded readers using a 5-point scale (1=poor, 5=excellent). Comparison of the dose length product (DLP) was used to estimate radiation exposure.Results: Seventy-three consecutive patients underwent imaging with the proposed CT protocols. The viewers rated the image quality of the dual-source image sets as nearly as good (3.62) as the single-source images on the same device (4.18) and those on 16-slice CT (3.7). DLP was cut to half of the dose [51 mGycm vs. 97.8 mGycm vs. 116.9 mGycm (p<0.01)].Conclusions: Using the proposed dual-source mode when examining the paranasal sinus, diagnostic image quality can be achieved while drastically lowering the patient's radiation exposure. [ABSTRACT FROM AUTHOR]

The aim of this study was to evaluate the clinical presentation, diagnosis and management of patients with intussusception, with special regard to the duration of symptoms, referral from other hospitals, outcome and complications related to delayed diagnosis. This retrospective study was performed using hospital charts, ultrasound and radiological reports and surgical notes from patients treated in our institution from 1996–2005. Altogether 98 patients were included in the study. The study revealed idiopathic intussusception in 95% of the cases. The remaining patients presented with Meckel’s diverticulum and schwannoma of the small bowel. We used ultrasound as the primary modality for diagnosis in all the patients, with a diagnostic accuracy of 100% in our study. Conservative treatment using an air enema was successful in 79.5% of cases. A higher rate of surgical intervention was found in patients who had symptoms for more than 24 h and in referred patients. Particular attention needs to be paid to the rapid diagnosis and appropriate treatment of intussusception. Uncertain cases should be urgently referred to specialised paediatric centres. Ultrasound should be the diagnostic method of choice, since it is very effective in making this diagnosis. The first treatment option for intussusception remains the enema. Delayed diagnosis leads to an increased number of open surgeries. [ABSTRACT FROM AUTHOR]

To evaluate tumor response after treating unresectable lung metastases with transpulmonary chemoembolization (TPCE) in palliative intention. From 2001 to 2005, 52 patients (mean: 59.8 years; 32 males/20 females) suffering from 106 unresectable lung metastases (mean:6 metastases/patient; range,1-21) were treated with 2-10 TPCE-sessions (mean: 3.3 sessions/patient). Metastases originated from primaries, including colorectal carcinoma (n = 20), breast cancer (n = 6), renal cellular carcinoma (n = 5), thyroid cancer (n = 4), cholangiocellular carcinoma (n = 2), leiomyosarcoma (n = 2), and others (n = 13). Tumor-feeding pulmonary arteries were selectively probed after puncturing the femoral vein, and administering 10 ml lipiodol, mitomycin C, and microspheres (Spherex) each via balloon catheter over pulmonary approach. During therapy, follow-up was accomplished at 4-week intervals using unenhanced and contrast-enhanced CT. After sequential therapy, follow-up was performed every 3 months for a period of 6 months up to 2.25 years. All patients tolerated the treatments well without major side effects or complications. In 24% (n = 13) moderate to high lipiodol uptake was found, while 75% (n = 39) of the tumors showed a low uptake. According to the RECIST criteria, "partial response" was achieved in 16 cases, "stable disease" in 11 cases, and "progressive disease" in 25 cases [mean survival: 17 months/median: 21.1 months (Kaplan-Meyer)]. According to these findings, TPCE is a well-tolerated procedure for palliative treatment of unresectable lung metastases. [ABSTRACT FROM AUTHOR]

The aim of the study was to evaluate the feasibility, safety and effectiveness of CT-guided and MR-thermometry-controlled laser-induced interstitial thermotherapy (LITT) in adrenal metastases. Nine patients (seven male, two female; average age 65.0 years; range 58.7-75.0 years) with nine unilateral adrenal metastases (mean diameter 4.3 cm) from primaries comprising colorectal carcinoma (n = 5), renal cell carcinoma (n = 1), oesophageal carcinoma (n = 1), carcinoid (n = 1), and hepatocellular carcinoma (n = 1) underwent CT-guided, MR-thermometry-controlled LITT using a 0.5 T MR unit. LITT was performed with an internally irrigated power laser application system with an Nd:YAG laser. A thermosensitive, fast low-angle shot 2D sequence was used for real-time monitoring. Follow-up studies were performed at 24 h and 3 months and, thereafter, at 6-month intervals (median 14 months). All patients tolerated the procedure well under local anaesthesia. No complications occurred. Average number of laser applicators per tumour: 1.9 (range 1-4); mean applied laser energy 33 kJ (range 15.3-94.6 kJ), mean diameter of the laser-induced coagulation necrosis 4.5 cm (range 2.5-7.5 cm). Complete ablation was achieved in seven lesions, verified by MR imaging; progression was detected in two lesions in the follow-up. The preliminary results suggest that CT-guided, MR-thermometry-controlled LITT is a safe, minimally invasive and promising procedure for treating adrenal metastases. [ABSTRACT FROM AUTHOR]

This study aims to evaluate the efficacy and safety of a neoadjuvant treatment protocol with repeated transarterial chemoembolization (TACE) before MR-guided laser-induced thermotherapy (LITT) for large-sized hepatocellular carcinomas (HCC). Repeated TACE (mean, 3.5 treatments per patient) was performed in 48 patients with neoadjuvant intention (the largest lesion was between 50 and 80 mm in diameter, and there were no more than five lesions). For the TACE treatment, we used 10 mg/m(2) mitomycin, 10 ml/m(2) Lipiodol and microspheres. The tumor volume was measured by MRI. Lipiodol retention of the tumors was evaluated with CT. After the diameter of the tumors had decreased to less than 50 mm, the patients were treated with MR-guided LITT 4 to 6 weeks after embolization. Repeated TACE reduced the tumor size in 32 patients (66.7%), forming the basis for performing MR-guided LITT procedures. These patients received one to four laser treatments (mean, 1.9 per patient) for tumor ablation, resulting in a median survival of 36.0 months after the first treatment. For the remaining patients, no reduction in tumor size was achieved in 12 patients and disease progression in 4 patients. Neoadjuvant TACE appears to be an effective treatment of large-sized HCC, which extends the indication for MR-guided LITT. [ABSTRACT FROM AUTHOR]

Interventional therapeutic methods are presented in Carney triad, which is a syndrome defined as the simultaneous presence of gastric leiomyosarcoma, extra-adrenal paraganglioma, and pulmonary chondroma. The paragangliomas in the carotid bifurcation and the mediastinum were successfully treated via transarterial embolization with particles. Three intrapulmonary chondromas were ablated using MRI-guided laser-induced thermotherapy (LITT) after previous devascularization via transvenous pulmonary particle embolization. In summary, interventional techniques could be a therapeutic option in patients suffering from Carney triad. [ABSTRACT FROM AUTHOR]

To assess the benefit of routinely used three-dimensional 1H-spectroscopy of the prostate combined with magnetic resonance imaging in patients with elevated prostate-specific antigen (PSA) levels and negative or no previous prostate biopsies. Fifty-four patients were examined with our combined imaging protocol, which consisted of transversal, coronal and sagittal T2-weighted fast spin echo sequences. For spectroscopy, we used a three-dimensional chemical shift imaging spin echo (3D-CSI-SE) sequence. The study population consisted of patients with elevated PSA levels and histologically proven prostate carcinoma and patients with elevated PSA levels and negative or no previous prostate biopsies. Examination time was 31 min, a time feasible for routine use. Eighty-eight tumour voxels and 67 control voxels of 27 patients with histologically proven prostate carcinoma were analysed. Ratios of (choline + creatine)/citrate [(Cho + Crea)/Cit] below 0.6 were classified as normal and above 0.6 as pathological. Applying this classification to 20 patients with tumour-suspicious lesions of the prostate and negative or no previous prostate biopsies, we could obtain a sensitivity and specificity for tumour detection of 100% and 69%, respectively. Our combined imaging protocol is feasible for routine use and can add valuable information for the diagnostic management of patients with negative or no previous prostate biopsies. [ABSTRACT FROM AUTHOR]

To assess the benefit of routinely used three-dimensional 1H-spectroscopy of the prostate combined with magnetic resonance imaging in patients with elevated prostate-specific antigen (PSA) levels and negative or no previous prostate biopsies. Fifty-four patients were examined with our combined imaging protocol, which consisted of transversal, coronal and sagittal T2-weighted fast spin echo sequences. For spectroscopy, we used a three-dimensional chemical shift imaging spin echo (3D-CSI-SE) sequence. The study population consisted of patients with elevated PSA levels and histologically proven prostate carcinoma and patients with elevated PSA levels and negative or no previous prostate biopsies. Examination time was 31 min, a time feasible for routine use. Eighty-eight tumour voxels and 67 control voxels of 27 patients with histologically proven prostate carcinoma were analysed. Ratios of (choline + creatine)/citrate [(Cho + Crea)/Cit] below 0.6 were classified as normal and above 0.6 as pathological. Applying this classification to 20 patients with tumour-suspicious lesions of the prostate and negative or no previous prostate biopsies, we could obtain a sensitivity and specificity for tumour detection of 100% and 69%, respectively. Our combined imaging protocol is feasible for routine use and can add valuable information for the diagnostic management of patients with negative or no previous prostate biopsies. [ABSTRACT FROM AUTHOR]

The purpose of this study was to examine the feasibility and safety of MR-guided biopsies with a transgluteal approach in patients with uncertain or suspicious prostate lesions. Twenty-five patients with uncertain or suspicious focal prostate lesions detected by high-field MR imaging of the prostate gland using endorectal coil imaging were biopsied with a transgluteal approach in a low-field MRI system (0.2 T, Concerto, Siemens). The procedures were guided using T1-weighted FLASH sequences. The prostate gland was biopsied repeatedly with a coaxial technique through a 15-gauge pencil tip with a 16-gauge biopsy handy (median 3.8 samples per patient). Complications and biopsy findings were documented retrospectively. Using T1-weighted sequences biopsy procedures were performed successfully with MR guidance in all cases without any side effects or complications. The median intervention time was 11.3 min. Pathological findings revealed ten cases of hyperplasia or atrophy, three cases of prostatitis, ten cases of carcinoma and two cases of normal tissue. The clinical follow-up showed that in two patients prostate cancer was missed at MR-guided biopsy. Transgluteal MR-guided biopsy of the prostate gland is a safe and promising approach for histological clarification of uncertain or suspicious lesions. [ABSTRACT FROM AUTHOR]

Gastrointestinal stromal tumours (GISTs), the most common mesenchymal tumours of the digestive tract, are largely resistant to chemo- and radiotherapy. They are currently defined by their overexpression of the KIT receptor tyrosine kinase (CD117), a member of the family of receptor tyrosine kinases (RTKs), and exhibit KIT mutations in more than 85% of cases. Additionally, in more than one-third of KIT wild-type GISTs, mutations of platelet-derived growth factor receptor alpha (PDGF-R alpha), which also belongs to the family of RTKs, were recently found. Since these data indicate that uncontrolled RTK signalling may be implicated in the pathogenesis of GISTs, RTKs and the activated downstream signalling cascades are attractive targets in the therapy of these tumours. Imatinib is a small-molecule inhibitor that selectively blocks the activity of the PDGF-R, ABL and KIT receptor tyrosine kinases by competitive binding to the adenosine triphosphate binding site of their catalytic domains. We herein review the molecular pathological, preclinical and clinical data that identify imatinib as a valuable new agent in the treatment of GISTs. [ABSTRACT FROM AUTHOR]

Five southern German university centers cooperated in comparing the effect of surgical vs. nonsurgical therapy strategies on survival and sphincter preservation in the treatment of anal cancer. A standardized questionnaire was used to evaluate retrospectively (mean follow-up 30 months) treatment strategy and outcome (survival, colostomy rate, colostomy-free survival) in patients treated between 1987 and 1996. Of the 142 patients 65% had squamous cell, 20% basaloid, 6% adeno-, and 1% undifferentiated carcinoma (8% histology not recorded); 9% were classified in UICC stage I, 37% in stage II, 25% in stage III, and 4% in stage IV (25% not recorded). Primary treatment consisted of local excision (10%), excision plus radio- and/or chemotherapy (17%), radiotherapy (20%), radio-chemotherapy (28%), or colostomy with or without resection, radiotherapy, and chemotherapy (23%). We observed no difference between these treatment groups in overall (P=0.43) or colostomy-free survival (P=0.14, log-rank). Primary colostomy was prevented in 77% of cases and decreased over the years. Mean overall survival (in months) was 42 in stage I, 38 in stage II, and 25 in stage III (P=0.0013); mean colostomy-free survival was 36 in stage I, 26 in stage II, and 16 in stage III (P=0.0021, log-rank). Outcome was not significantly related to therapeutic strategy (surgery or radio-chemotherapy. Primary surgical and nonsurgical strategies in treating anal cancer thus produced similar results, although radio-chemotherapy is usually recommended for sphincter-endangering anal cancer. Challenges to be met in the future include the prevention of metastasis and long-term preservation of anal sphincter function. [ABSTRACT FROM AUTHOR]

Prospects for a new biologically based strategy of cancer treatment are being discussed. While physically and chemically based therapies, such as radio- and chemotherapy, are not directed against cancer tissue only and have a suppressive effect on the immune system, immunotherapy and gene therapy, which are discussed here, try to be more selective and to stimulate rather than suppress antitumor immune mechanisms. On the basis of personal experience with these new technologies, good future prospects are predicted for the application of cancer vaccines and immune T lymphocytes for active specific immunization (ASI) and adoptive immunotherapy (ADI) respectively. While ASI strategies aim at micrometastases being affected by activated host immune T cells, and might find a place for postoperative adjuvant treatment in high-risk cancer patients, cellular therapies such as ADI do not require an intact host immune system and could therefore also find application in advanced stages of disease. In spite of the exciting new perspectives of immuno- and gene therapy for the cancer patient, this therapy is not yet a defined discipline and requires years of further research. [ABSTRACT FROM AUTHOR]

Male Wistar rats were treated concurrently with a combination of the carcinogen N-methyl- N′-nitro- N-nitrosoguanidine (MNNG; CAS 70-25-7) and the polyamine-synthesis inhibitor α-difluoromethylornithine (DFMO) at two different doses of 0.5% and 1.0% (w/v). Experimental groups were treated with (I) MNNG alone ( n=25), (II) MNNG plus 0.5% (w/v) DFMO ( n=25), (III) MNNG plus 1.0% (w/v) DFMO ( n=25), (IV) 1.0% (w/v) DFMO alone ( n=25). Group V represented untreated controls ( n=20). Both the carcinogen and DFMO were administered in drinking water. The treatment time with the carcinogen and DFMO was 35 weeks. After treatment was completed animals were followed for an additional 50 weeks to cover a total observation time of 85 weeks. Significantly fewer animals developed gastric adenocarcinoma in the two groups of animals that received a combined treatment of MNNG plus DFMO compared to animals treated with the carcinogen alone ( P<0.05 and 0.005). No benign or malignant neoplastic lesions were observed in the stomach or duodenum of animals treated with DFMO alone or in untreated controls. It is concluded that concurrent treatment with DFMO prevents the development of malignant gastric epithelial tumors induced by MNNG in rats. [ABSTRACT FROM AUTHOR]

The effect of N-methyl- N'-nitro- N-nitrosoguanidine (MNNG) on the mucin phenotype of non-metaplastic gastric mucosa in the rat was studied histochemically. Animals were exposed to MNNG in drinking water (83 mg/l) for 12 weeks. Carcinogen treatment was then discontinued and the animals (27 in the treatment group and 25 in the control group) were examined after another 44 weeks. Glycosylation was analysed with histochemical stains for sialomucins and sulphomucins and with peroxidase-conjugated lectins (GS-II, SBA, DBA, UEA-I, and WGA). Sialo-and sulphomucins remained quantitatively unchanged, only a slight increase of acid mucins in the antral glands was observed. The analysis of the lectin binding patterns, however, revealed a significant increase for WGA-binding glycoproteins in the surface mucous cells and gastric pits, while DBA binding was significantly decreased ( P<0.05). GS-II lectin bound specifically to the proliferative compartment in the gastric fundus, consisting of mucous neck cells, and was significantly increased after MNNG treatment. No specific alterations were detected in lectin binding to parietal or chief cells. It is concluded, therefore, that treatment of gastric mucosa with MNNG alters the glycoprotein metabolism before intestinal metaplasia can be observed. [ABSTRACT FROM AUTHOR]

The article investigates the presence of enteric intussusception in an adult population. The disease is commonly found in children. However, in this particular case, the HIV-positive patient showed positive symptoms such as abdominal pain and nausea. Dilated small-bowel loops were confirmed through plain abdominal X-ray. The appearance of intussusception consists of a thickened bowel.

Studies of the real-time dynamics of embryonic development require a gentle embryo handling method, the possibility of long-term live imaging during the complete embryogenesis, as well as of parallelization providing a population's statistics, while keeping single embryo resolution. We describe an automated approach that fully accomplishes these requirements for embryos of Caenorhabditis elegans, one of the most employed model organisms in biomedical research. We developed a microfluidic platform which makes use of pure passive hydrodynamics to run on-chip worm cultures, from which we obtain synchronized embryo populations, and to immobilize these embryos in incubator microarrays for long-term high-resolution optical imaging. We successfully employ our platform to investigate morphogenesis and mitochondrial biogenesis during the full embryonic development and elucidate the role of the mitochondrial unfolded protein response (UPRmt) within C. elegans embryogenesis. Our method can be generally used for protein expression and developmental studies at the embryonic level, but can also provide clues to understand the aging process and age-related diseases in particular. [ABSTRACT FROM AUTHOR]