Shear Wave Dispersion Imaging for the Characterization of Focal Liver Lesions - A Pilot study

PURPOSE

Shear wave dispersion imaging is a novel ultrasound-based technique, which analyzes the speed of different shear wave components depending on their frequency. The dispersion of shear wave speed correlates with the viscosity of the liver parenchyma. The aim of this prospective study was to evaluate the use of shear wave dispersion imaging in focal liver lesions in the non-cirrhotic liver.

METHODS

Patients with unclear focal liver lesions in B-mode ultrasound were prospectively assigned to shear wave dispersion imaging (m/s/kHz). Measurements were conducted within the lesion and in the liver parenchyma of the right liver lobe using an intercostal window. Histology and contrast-enhanced ultrasound served as the reference for the characterization of the lesions.

RESULTS

Out of 46 patients included in this study, 24 had liver metastases and 22 had benign liver lesions. Benign lesions consisted mostly of hemangiomas (n=12) and focal nodular hyperplasia (n=8). Malignant lesions showed significantly lower shear wave dispersion (13.0±2.45 m/s/kHz) compared to benign tumors (15.2±2.74 m/s/kHz, p<0.01). In further subgroup analysis, the difference was significant for hemangiomas (15.32±2.42 m/s/kHz, p=0.04) but not for FNHs (14.98±3.36 m/s/kHz, p=0.38). The dispersion of reference liver parenchyma did not differ significantly between the groups (p=0.54).

CONCLUSION

The quantification of viscosity by shear wave dispersion is a new parameter for the characterization of focal liver lesions with higher dispersion values in hemangiomas and lower dispersion values in metastases. However, it cannot differentiate reliably between benign and malignant lesions.

Linkage between growth retardation and pituitary cell morphology in a dystrophin-deficient pig model of Duchenne muscular dystrophy

OBJECTIVE

Human patients with Duchenne muscular dystrophy (DMD) commonly exhibit a short stature, but the pathogenesis of this growth retardation is not completely understood. Due to the suspected involvement of the growth hormone/insulin-like growth factor 1 (GH/IGF1) system, controversial therapeutic approaches have been developed, including both GH- administration, as well as GH-inhibition. In the present study, we examined relevant histomorphological and ultrastructural features of adenohypophyseal GH-producing somatotroph cells in a porcine DMD model.

METHODS

The numbers and volumes of immunohistochemically labelled somatotroph cells were determined in consecutive semi-thin sections of plastic resin embedded adenohypophyseal tissue samples using unbiased state-of-the-art quantitative stereological analysis methods.

RESULTS

DMD pigs displayed a significant growth retardation, accounting for a 55% reduction of body weight, accompanied by a significant 50% reduction of the number of somatotroph cells, as compared to controls. However, the mean volumes of somatotroph cells and the volume of GH-granules per cell were not altered. Western blot analyses of the adenohypophyseal protein samples showed no differences in the relative adenohypophyseal GH-abundance between DMD pigs and controls.

CONCLUSION

The findings of this study do not provide evidence for involvement of somatotroph cells in the pathogenesis of growth retardation of DMD pigs. These results are in contrast with previous findings in other dystrophin-deficient animal models, such as the golden retriever model of Duchenne muscular dystrophy, where increased mean somatotroph cell volumes and elevated volumes of intracellular GH-granules were reported and associated with DMD-related growth retardation. Possible reasons for the differences of somatotroph morphology observed in different DMD models are discussed.

Bounding Global Aerosol Radiative Forcing of Climate Change

Aerosols interact with radiation and clouds. Substantial progress made over the past 40 years in observing, understanding, and modeling these processes helped quantify the imbalance in the Earth's radiation budget caused by anthropogenic aerosols, called aerosol radiative forcing, but uncertainties remain large. This review provides a new range of aerosol radiative forcing over the industrial era based on multiple, traceable, and arguable lines of evidence, including modeling approaches, theoretical considerations, and observations. Improved understanding of aerosol absorption and the causes of trends in surface radiative fluxes constrain the forcing from aerosol-radiation interactions. A robust theoretical foundation and convincing evidence constrain the forcing caused by aerosol-driven increases in liquid cloud droplet number concentration. However, the influence of anthropogenic aerosols on cloud liquid water content and cloud fraction is less clear, and the influence on mixed-phase and ice clouds remains poorly constrained. Observed changes in surface temperature and radiative fluxes provide additional constraints. These multiple lines of evidence lead to a 68% confidence interval for the total aerosol effective radiative forcing of -1.6 to -0.6 W m-2, or -2.0 to -0.4 W m-2 with a 90% likelihood. Those intervals are of similar width to the last Intergovernmental Panel on Climate Change assessment but shifted toward more negative values. The uncertainty will narrow in the future by continuing to critically combine multiple lines of evidence, especially those addressing industrial-era changes in aerosol sources and aerosol effects on liquid cloud amount and on ice clouds.

Health literacy of commercial industry managers: an exploratory qualitative study in Germany

Background

Managers have been neglected in health literacy research. There still is little known about the health literacy status and needs of commercial industry managers. This study reduces the existing knowledge gap by presenting findings of an exploratory qualitative study.

Methods

We conducted 23 separate semi-structured interviews of managers from all management levels (low, middle and top) and experts in the field of health management and/or personnel management. The qualitative interviews were analysed according to Mayring’s content analytic approach using MAXQDA.

Results

The findings indicate that managers do have considerable information levels about existing health topics and relevant problems but have difficulties of discernment as to which sources of information can be activated or accessed in a timely fashion due to work and information overload. Even those who devise strategies often fail in implementing health-literate behavior. Experts and managers had fairly consistent views on the importance of health literacy among managers. Most agreed that mental health was neglected and that company conditions were important in influencing the ability to act in a way that promoted health literacy. The findings also show that strengthening of managerial self-perception, self-regulation and self-control, raising awareness and ability to take personal responsibility for one’s own health, developing skills in handling large amounts of information and fostering open and trusting communication are all essential.

Conclusions

The findings provide specific points which are important for promoting health literacy among managers. The study underscores the need to incorporate and integrate different perspectives in the implementation of health literacy interventions. To develop health-promoting companies, further research has to provide guides to action for managers and investigate ways in which health literacy can be promoted among managers on all hierarchical levels.

Key messages

Industry managers in this study agreed that their mental health has been neglected and company conditions were important in influencing the ability to act in a way that promoted health literacy. This study reduces the knowledge gap about the health literacy of managers. Further research should focus on promoting mental health and providing guides to action for managers and companies.

Registered Replication Report: Rand, Greene, and Nowak (2012)

In an anonymous 4-person economic game, participants contributed more money to a common project (i.e., cooperated) when required to decide quickly than when forced to delay their decision (Rand, Greene & Nowak, 2012), a pattern consistent with the social heuristics hypothesis proposed by Rand and colleagues. The results of studies using time pressure have been mixed, with some replication attempts observing similar patterns (e.g., Rand et al., 2014) and others observing null effects (e.g., Tinghög et al., 2013; Verkoeijen & Bouwmeester, 2014). This Registered Replication Report (RRR) assessed the size and variability of the effect of time pressure on cooperative decisions by combining 21 separate, preregistered replications of the critical conditions from Study 7 of the original article (Rand et al., 2012). The primary planned analysis used data from all participants who were randomly assigned to conditions and who met the protocol inclusion criteria (an intent-to-treat approach that included the 65.9% of participants in the time-pressure condition and 7.5% in the forced-delay condition who did not adhere to the time constraints), and we observed a difference in contributions of -0.37 percentage points compared with an 8.6 percentage point difference calculated from the original data. Analyzing the data as the original article did, including data only for participants who complied with the time constraints, the RRR observed a 10.37 percentage point difference in contributions compared with a 15.31 percentage point difference in the original study. In combination, the results of the intent-to-treat analysis and the compliant-only analysis are consistent with the presence of selection biases and the absence of a causal effect of time pressure on cooperation.

Tigecycline resistance in clinical isolates of Enterococcus faecium is mediated by an upregulation of plasmid-encoded tetracycline determinants tet(L) and tet(M)

OBJECTIVES

Tigecycline represents one of the last-line therapeutics to combat multidrug-resistant bacterial pathogens, including VRE and MRSA. The German National Reference Centre for Staphylococci and Enterococci has received 73 tigecycline-resistant Enterococcus faecium and Enterococcus faecalis isolates in recent years. The precise mechanism of how enterococci become resistant to tigecycline remains undetermined. This study documents an analysis of the role of efflux pumps in tigecycline resistance in clinical isolates of Enterococcus spp.

METHODS

Various tigecycline MICs were found for the different isolates analysed. Tigecycline-resistant strains were analysed with respect to genome and transcriptome differences by means of WGS and RT-qPCR. Genes of interest were cloned and expressed in Listeria monocytogenes for verification of their functionality.

RESULTS

Detailed comparative whole-genome analyses of three isogenic strains, showing different levels of tigecycline resistance, revealed the major facilitator superfamily (MFS) efflux pump TetL and the ribosomal protection protein TetM as possible drug resistance proteins. Subsequent RT-qPCR confirmed up-regulation of the respective genes. A correlation of gene copy number and level of MIC was inferred from further qPCR analyses. Expression of both tet(L) and tet(M) in L. monocytogenes unequivocally demonstrated the potential to increase tigecycline MICs upon acquisition of either locus.

CONCLUSIONS

Our results indicate that increased expression of two tetracycline resistance determinants, a tet(L)-encoded MFS pump and a tet(M)-encoded ribosomal protection protein, is capable of conferring tigecycline resistance in enterococcal clinical isolates.

[Duration of inability for work and return to physical work after arthroscopic and open labrum refixation]

BACKGROUND AND INTRODUCTION

The duration of inability for work according to work load and the rate of successful return to work after open and arthroscopic Bankart repair (BR) due to anterior shoulder dislocation has not yet been examined with regard to validated work strain by the REFA classification. Thus, the objective of this study was to determine the duration of inability to work according to work load (REFA criteria) after open and arthroscopic BR as well as the rate of successful return to the original occupation.

PATIENTS AND METHODS

A total of 93 patients (20 f/73 m) with isolated anterior arthroscopic or open BR due to posttraumatic anterior shoulder instability with no items of hyperlaxity were included in this study. There were 72 patients with arthroscopic and 21 patients with open BR. The postoperative aftercare was standardised and identical. The clinical assessment included the Constant and Murley scores, UCLA shoulder and the Rowe score for shoulder instability. Average follow-up time was 48.3 months (SD ± 23.6 months) with a mean age of 37.1 years (SD ± 14.4 years). The work load was classified according to the German REFA Association. Operation time, duration of inability for work and clinical outcome were analysed and compared according to the operation technique.

RESULTS

Mean incapacity for work in the group of arthroscopic BR was 3.3 months (SD ± 2.5) and 2.7 months (SD + 2.3 months; p = 0.37) in the group of open BR demonstrating no statistical difference. Both mean time for surgery (p = 0.0003) and in-hospital stay (p = 0.0083) showed significant differences when comparing patients with low work load (REFA 0-1) and higher work load (REFA 2-4) irrespective of the surgical approach. Overall analysis showed an average time of 2.3 months (SD ± 1.5) to return to work for patients with low work load (REFA 0-1) and 4.2 months (SD ± 2.9) for individuals with high work load (REFA 2-4) revealing significant differences (p = 0.0006). The mean inability for work after arthroscopic BR for patients with REFA 0-1 was 2.4 months (SD ± 1.6) and 4.2 months (± 2,9; p = 0.0053) for patients with REFA 2-4 revealing a significant difference. The mean inability for work after open BR for individuals with REFA 0-1 was 1.8 months (± 1.0) and 4.3 months (± 3.3; p = 0.1196) for individuals with REFA 2-4. Two out of 35 patients (5.7 %) with low work load (REFA 0-1) and 10 out of 37 patients (27 %) with high work load (REFA 2-4) could not return to their original occupation after arthroscopic BR. One out of 14 patients (7.1 %) with low work load (REFA 0-1) and 4 out of 7 patients (57.1 %) with high work load (REFA 2-4) could not return to their original occupation after open BR. Comparing these results between arthroscopic and open BR, no significant differences were obtained (chi-square, Pearson). Recurrent shoulder dislocation occurred in the arthroscopic group in 14.3 % (REFA 0-1) and 8.1 % (REFA 2-4) compared to the open procedure group in 0 % (REFA 0-1) and 14 % (REFA 2-4) revealing no statistically significant differences.

CONCLUSION

This study showed equivalent results after performing open and arthroscopic BR with significantly shorter operation times and in-hospital stays after arthroscopic BR. Higher work loads caused longer inability for work irrespective of the chosen surgical technique. On the basis of these results we recommend arthroscopic BR as the standard primary procedure, while the overall rate of return to work without restrictions of 81.7 % has to be improved in the future.

Importance of charge fluctuations for the topological phase in SmB(6)

Typical Kondo insulators (KIs) can have a nontrivial Z_{2} topology because the energy gap opens at the Fermi energy (E_{F}) by a hybridization between odd- and even-parity bands. SmB_{6} deviates from such KI behavior, and it has been unclear how the insulating phase occurs. Here, we demonstrate that charge fluctuations are the origin of the topological insulating phase in SmB_{6}. Our angle-resolved photoemission spectroscopy results reveal that with decreasing temperature the bottom of the d-f hybridized band at the X[over ¯] point, which is predicted to have odd parity and is required for a topological phase, gradually shifts from below to above E_{F}. We conclude that SmB_{6} is a charge-fluctuating topological insulator.

Climatology of nocturnal low-level jets over North Africa and implications for modeling mineral dust emission

[1] This study presents the first climatology for the dust emission amount associated with Nocturnal Low-Level Jets (NLLJs) in North Africa. These wind speed maxima near the top of the nocturnal boundary layer can generate near-surface peak winds due to shear-driven turbulence in the course of the night and the NLLJ breakdown during the following morning. The associated increase in the near-surface wind speed is a driver for mineral dust emission. A new detection algorithm for NLLJs is presented and used for a statistical assessment of NLLJs in 32 years of ERA-Interim reanalysis from the European Centre for Medium-Range Weather Forecasts. NLLJs occur in 29% of the nights in the annual and spatial mean. The NLLJ climatology shows a distinct annual cycle with marked regional differences. Maxima of up to 80% NLLJ frequency are found where low-level baroclinicity and orographic channels cause favorable conditions, e.g., over the Bodélé Depression, Chad, for November-February and along the West Saharan and Mauritanian coast for April-September. Downward mixing of NLLJ momentum to the surface causes 15% of mineral dust emission in the annual and spatial mean and can be associated with up to 60% of the total dust amount in specific areas, e.g., the Bodélé Depression and south of the Hoggar-Tibesti Channel. The sharp diurnal cycle underlines the importance of using wind speed information with high temporal resolution as driving fields for dust emission models. Citation: Fiedler, S., K. Schepanski, B. Heinold, P. Knippertz, and I. Tegen (2013), Climatology of nocturnal low-level jets over North Africa and implications for modeling mineral dust emission, J. Geophys. Res. Atmos., 118, 6100-6121, doi:10.1002/jgrd.50394.

The role of deep convection and nocturnal low-level jets for dust emission in summertime West Africa: Estimates from convection-permitting simulations

[1] Convective cold pools and the breakdown of nocturnal low-level jets (NLLJs) are key meteorological drivers of dust emission over summertime West Africa, the world's largest dust source. This study is the first to quantify their relative contributions and physical interrelations using objective detection algorithms and an off-line dust emission model applied to convection-permitting simulations from the Met Office Unified Model. The study period covers 25 July to 02 September 2006. All estimates may therefore vary on an interannual basis. The main conclusions are as follows: (a) approximately 40% of the dust emissions are from NLLJs, 40% from cold pools, and 20% from unidentified processes (dry convection, land-sea and mountain circulations); (b) more than half of the cold-pool emissions are linked to a newly identified mechanism where aged cold pools form a jet above the nocturnal stable layer; (c) 50% of the dust emissions occur from 1500 to 0200 LT with a minimum around sunrise and after midday, and 60% of the morning-to-noon emissions occur under clear skies, but only 10% of the afternoon-to-nighttime emissions, suggesting large biases in satellite retrievals; (d) considering precipitation and soil moisture effects, cold-pool emissions are reduced by 15%; and (e) models with parameterized convection show substantially less cold-pool emissions but have larger NLLJ contributions. The results are much more sensitive to whether convection is parameterized or explicit than to the choice of the land-surface characterization, which generally is a large source of uncertainty. This study demonstrates the need of realistically representing moist convection and stable nighttime conditions for dust modeling. Citation: Heinold, B., P. Knippertz, J. H. Marsham, S. Fiedler, N. S. Dixon, K. Schepanski, B. Laurent, and I. Tegen (2013), The role of deep convection and nocturnal low-level jets for dust emission in summertime West Africa: Estimates from convection-permitting simulations, J. Geophys. Res. Atmos., 118, 4385-4400, doi:10.1002/jgrd.50402.

Graveyards - special landfills

Graveyards have been a matter of controversial debate for many years in terms of the risk they pose to the environment. However, literature data are inconclusive and there are no systematic studies available from modern graveyards with special reference to soil found in the vicinity of the coffin. To our knowledge, the present study is the first to systematically investigate a comprehensive exhumation series (involving 40 graves) in order to determine burial-related changes in matter and element content. Human burials lead to the accumulation of certain elements, with higher than normal levels of N, C, Zn, Ba, Ca and Na being observed in soils below coffins. Decomposition material inside coffins has much higher levels of heavy metals and alkaline elements than the surrounding soil. However, the major problem observed was the large quantity of synthetic bedding material which is more likely to lead to the formation of adipocere under the moist conditions given. Adipocere formation, which is the result of the anaerobic bacterial hydrolysis of fat, is known to interrupt the natural decomposition process and delay the post-mortem release of elements. We assume that once the inhumed matter has completely decomposed, much higher than normal levels of pollutants will be released into and have an ecological effect on the soil and water environment.

Temperature dependence of greenhouse gas emissions from three hydromorphic soils at different groundwater levels

Wetlands contribute considerably to the global greenhouse gas (GHG) balance. In these ecosystems, groundwater level (GWL) and temperature, two factors likely to be altered by climate change, exert important control over CO(2), CH(4) and N(2)O fluxes. However, little is known about the temperature sensitivity (Q(10)) of the combined GHG emissions from hydromorphic soils and how this Q(10) varies with GWL. We performed a greenhouse experiment in which three different (plant-free) hydromorphic soils from a temperate spruce forest were exposed to two GWLs (an intermediate GWL of -20 cm and a high GWL of -5 cm). Net CO(2), CH(4) and N(2)O fluxes were measured continuously. Here, we discuss how these fluxes responded to synoptic temperature fluctuations. Across all soils and GWLs, CO(2) emissions responded similarly to temperature and Q(10) was close to 2. The Q(10) of the CH(4) and N(2)O fluxes also was similar across soil types. GWL, on the other hand, significantly affected the Q(10) of both CH(4) and N(2)O emissions. The Q(10) of the net CH(4) fluxes increased from about 1 at GWL = -20 cm to 3 at GWL = -5 cm. For the N(2)O emissions, Q(10) varied around 2 for GWL = -20 cm and around 4 for GWL = -5 cm. This substantial GWL-effect on the Q(10) of CH(4) and N(2)O emissions was, however, hardly reflected in the Q(10) of the total GHG emissions (which varied around 2), because the contribution of these gases was relatively small compared to that of CO(2).

The cannabinoid receptor-1 antagonist rimonabant inhibits platelet activation and reduces pro-inflammatory chemokines and leukocytes in Zucker rats

BACKGROUND AND PURPOSE

We investigated the effect of rimonabant on inflammation and enhanced platelet reactivity in type 2 diabetic Zucker rats, an experimental model of impaired glucose tolerance and the metabolic syndrome.

EXPERIMENTAL APPROACH

Rimonabant (10 mg kg(-1) by gavage) was fed for 2 weeks to 3-month-old male obese Zucker rats as an impaired glucose tolerance model and for 10 weeks to 6-month-old male obese Zucker rats as a model of the metabolic syndrome. RANTES (Regulated upon Activation, Normal T cell Expressed, and Secreted) and MCP-1 (monocyte chemotactic protein-1) serum levels were determined by ELISA. Leukocyte populations were quantitatively assessed using a veterinary differential blood cell counter. Platelet activation was assessed by flow-cytometry, platelet aggregation, and adhesion of isolated platelets to immobilized fibrinogen.

KEY RESULTS

RANTES and MCP-1 serum levels were increased in obese vs lean Zucker rats and significantly reduced by long-term treatment with rimonabant, which slowed weight gain in rats with the metabolic syndrome. Neutrophils and monocytes were significantly increased in young and old obese vs lean Zucker rats and lowered by rimonabant. Platelet-bound fibrinogen was significantly enhanced in obese vs lean Zucker rats of both age, and was reduced by rimonabant. Platelets from obese rats were more sensitive to thrombin-induced aggregation and adhesion to fibrinogen, which were both attenuated by rimonabant therapy.

CONCLUSIONS AND IMPLICATIONS

We demonstrate positive modulation of circulating neutrophil and monocyte numbers, reduced platelet activation and lower RANTES and MCP-1 levels by rimonabant in Zucker rats. This may potentially contribute to a reduction of cardiovascular risk.

Alkylphenols in sediments of the Atlantic Rainforest south-west of São Paulo, Brazil

Concentrations of technical 4-nonylphenol, 4-n-octylphenol, and 4-tert-octylphenol were investigated in surface water and sediment samples of four reservoirs southwest of São Paulo. Three of them (Takimoto 1, Takimoto 2, Pedro) were established in intensively cropped landscapes, one (Morro Grande) was surrounded by dense forests. Total alkylphenol concentrations in sediments generally ranged between 1 and 10 microgkg-1dw with 4-tert-octylphenol being the dominant alkylphenol. Because 4-tert-octylphenol concentration patterns at Takimoto 2, Pedro, and in the Morro Grande forest reservoir were found to be quite similar (upto 5 microgkg-1dw), this value is considered as the ubiquitous background level. In contrast, the Takimoto 1 sediments showed significantly higher 4-tert-octylphenol concentrations, possibly due to accelerated inputs from adjacent intensively cropped fields. Analysed alkylphenols were not detectable in water samples.

Characterization of soils containing adipocere

The formation of adipocere (commonly known as grave wax), a spontaneous inhibition of postmortem changes, has been extensively analyzed in forensic science. However, soils in which adipocere formation occurs have never been described in detail. Therefore, this study is intended as a first step in the characterization of soils containing adipocere. Two grave soils (Gleyic Anthrosols) that prevent the timely reuse of graves due to the occurrence of adipocere and a control soil (Gleyic Luvisol) were selected from a cemetery in the Central Black Forest (Southwest Germany). Descriptions of soil morphology and a wide assay of physical, chemical, and microbiologic soil characteristics were accomplished. In contrast to the control soil, the grave soils were characterized by lower bulk density and pH. The degradation of the soil structure caused by digging led to a higher water table and the expansion of the reducing conditions in the graves where the prevalent absence of oxygen in range of the coffins inhibited decomposition processes. Although the formation of adipocere led to the conservation of the buried corpses, phosphorus, dissolved organic carbon, and cadavarine leaching from the graves was observed. Microbial biomass and microbial activity were higher in the control soil and hence reflected the inert character of adipocere. The study results clearly show the need for additional approaches in forensic, pedologic, and microbiologic research.

Imaging lobular breast carcinoma: comparison of synchrotron radiation DEI-CT technique with clinical CT, mammography and histology

Different modalities for imaging cancer-bearing breast tissue samples are described and compared. The images include clinical mammograms and computed tomography (CT) images, CT images with partly coherent synchrotron radiation (SR), and CT and radiography images taken with SR using the diffraction enhanced imaging (DEI) method. The images are evaluated by a radiologist and compared with histopathological examination of the samples. Two cases of lobular carcinoma are studied in detail. The indications of cancer are very weak or invisible in the conventional images, but the morphological changes due to invasion of cancer become pronounced in the images taken by the DEI method. The strands penetrating adipose tissue are seen clearly in the DEI-CT images, and the histopathology confirms that some strands contain the so-called 'Indian file' formations of cancer cells. The radiation dose is carefully measured for each of the imaging modalities. The mean glandular dose (MGD) for 50% glandular breast tissue is about 1 mGy in conventional mammography and less than 0.25 mGy in projection DEI, while in the clinical CT imaging the MGD is very high, about 45 mGy. The entrance dose of 95 mGy in DEI-CT imaging gives rise to an MGD of 40 mGy, but the dose may be reduced by an order of magnitude, because the contrast is very large in most images.

[Follicle centre lymphoma: treatment results for stage I and II]

PURPOSE

Radiotherapy is a curative treatment modality in the early stages of follicle centre lymphoma. Survival rates, patterns of failure and prognostic factors were evaluated in a retrospective analysis.

PATIENTS AND METHODS

116 patients with follicle centre lymphoma stage I and II were treated between 1970 and 1999 in Dresden. Therapy modalities were radiotherapy alone (103 patients) or combined radiotherapy/chemotherapy (13 patients). Radiotherapy was applied as involved-field-(IFI)- (104 patients), extended-field- (nine patients) or total-nodal- (three patients) irradiation. Patients received doses between 25 Gy and 50 Gy (median 35 Gy).

RESULTS

The 5- and 10-year actuarial overall survival rates were 76% and 51%. Relapse free survival was 62% and 48% respectively. The median follow-up was 4,0 years. Relapses after complete remission were registered in 44 cases. Six patients have had in-field-recurrences. The majority of out-field-recurrences were nodal relapses (50%). 11% of relapses occurred outside of lymph nodes or were disseminated failures (18%). Significant favorable prognostic factors identified by multivariate and univariate analysis were low age (age < 50 years vs. age > 50 years), low stage and performance of bipedal lymphangiography as primary staging procedure.

CONCLUSIONS

Radiotherapy is an effective and tolerable treatment modality for follicle centre lymphoma in the early stages I and II. We registered a high proportion of nodal recurrences, which may be minimized by prophylactic extended radiotherapy.

Lack of cell death enhancement after irradiation with monochromatic synchrotron X rays at the K-shell edge of platinum incorporated in living SQ20B human cells as cis-diamminedichloroplatinum (II)

In this paper we describe the results of experiments using synchrotron radiation to trigger the Auger effect in living human cancer cells treated with a widely used chemotherapy drug: cis-diamminedichloroplatinum (II) (cisplatin). The experiments were carried out at the ID17 beamline of the European Synchrotron Radiation Facility, which produces a high-fluence monochromatic beam that is adjustable from 20 to 80 keV. Cisplatin was chosen as the carrier of platinum atoms in the cells because of its alkylating-like activity and the irradiation was done with monochromatic beams above and below the platinum K-shell edge (78.39 keV). Cell survival curves were comparable with those obtained for the same cells under conventional irradiation conditions. At a low dose of cisplatin (0.1 microM, 48 h), no difference was seen in survival when the cells were irradiated above and below the K-shell edge of platinum. Higher cisplatin concentrations were investigated to enhance the cellular platinum content. The results with 1 microM cisplatin for 12 h showed no difference when the cells were irradiated with beams above or below the platinum K-shell edge with the exception of the higher cell death resulting from drug toxicity. The intracellular content of platinum was significant, as measured macroscopically by inductively coupled plasma mass spectrometry. Its subcellular localization and particularly its presence in the cell nucleus were verified by microscopic synchrotron X-ray fluorescence. This was the first known attempt at K-shell edge photon activation of stable platinum in living cells with a platinum complex used for chemotherapy. Its evident toxicity in these cells leads us to put forth the hypothesis that cisplatin toxicity can mask the enhancement of cell death induced by the irradiation above the K-shell edge. However, K-shell edge photon activation of stable elements provides a powerful technique for the understanding of the biological effects of Auger processes. Further avenues of development are discussed.

Quantitative functional lung imaging with synchrotron radiation using inhaled xenon as contrast agent

Small airways play a key role in the distribution of ventilation and in the matching of ventilation to perfusion. The purpose of this study was to introduce an imaging method that allows measurement of regional lung ventilation and evaluation of the function of airways with a small diameter. The experiments were performed at the Medical Beamline of the European Synchrotron Radiation Facility. Monochromatic synchrotron radiation beams were used to obtain quantitative respiration-gated images of lungs and airways in two anaesthetized and mechanically ventilated rabbits using inhaled stable xenon (Xe) gas as a contrast agent. Two simultaneous images were acquired at two different energies, above and below the K-edge of Xe. Logarithmic subtraction of the two images yields absolute Xe concentrations. This technique is known as K-edge subtraction (KES) radiography. Two-dimensional planar and CT images were obtained showing spatial distribution of Xe concentrations within the airspaces, as well as the dynamics of filling with Xe. Bronchi down to 1 mm in diameter were visible both in the subtraction radiographs and in tomographic images. Absolute concentrations of Xe gas were calculated within the tube carrying the inhaled gas mixture, small and large bronchi, and lung tissue. Local time constants of ventilation with Xe were obtained by following the evolution of gas concentration in sequential computed tomography images. The results of this first animal study indicate that KES imaging of lungs with Xe gas as a contrast agent has great potential in studies of the distribution of ventilation within the lungs and of airway function, including airways with a small diameter.

Feasibility of synchrotron radiation computed tomography on rats bearing glioma after iodine or gadolinium injection. Jeune Equipe RSRM-UJF

The purpose of this work was to demonstrate the feasibility of a new imaging technique called synchrotron radiation computed tomography (SRCT). This technique leads to a direct assessment of the in vivo concentration of an iodine- or gadolinium-labeled compound. Rats bearing C6 glioma were imaged by MRI prior to the SRCT experiment. The SRCT experiments were performed after a 1.3 g I/kg (n = 5) or a 0.4 g Gd/kg (n = 5) injection. Finally, brains were sampled for histology. The SRCT images exhibited contrast enhancement at the tumor location. Ten minutes after injection, iodine and gadolinium tissular concentrations were equal to 0.80 ( +/- 0.40) mg/cm3 and 0.50 ( +/- 0.10) mg/cm3, respectively in the peripheral area of the tumor (respective background value: 0.20 +/- 0.02 to 0.10 +/- 0.01). Correlation to MRI and histology revealed that the contrast uptake occurred in the most vascularized area of the tumor. The present study summarizes the feasibility of in vivo SRCT to obtain quantitative information about iodine and gadolinium-labeled compounds. Beyond brain tumor pathology, the SRCT appears as a complementary approach to MRI and CT, for studying iodine- and gadolinium-labeled compounds by the direct achievement of the tissular concentration value in the tissue.

Initial stability of fully and partially cemented femoral stems

OBJECTIVE

To test the initial stability of a newly designed partially cemented femoral stem in comparison with a fully cemented conventional stem.

DESIGN

An in vitro study to determine the interface motion between femoral stem and bone as a response to loading.

BACKGROUND

The aim of the new prosthesis design is a proximal load transfer by a defined partial cement fixation in the proximal femur region and a slim prosthesis stem in the distal region. Before a clinical study can be started, the new stem has to show an initial stability comparable to that of fully cemented prostheses.

METHOD

Six paired fresh cadaveric femora were used for the testing of the new partially cemented stem (Option 3000, Mathys Orthopaedics, Bettlach, Switzerland) and a fully cemented stem (Weber Shaft, AlloPro, Baar, Swizerland). Under cyclic loading up to 1600 N hip joint forces, the interface motion between implants and bone was measured at six locations.

RESULTS

Both stems showed uncritical interface motions below 43 microm. However, the Option 3000 stem exhibited significantly smaller motions in the proximal region and slightly larger movements in the distal regions than the Weber prosthesis.

CONCLUSIONS

The new type of partially cemented stem provided a comparable initial stability to the fully cemented Weber prosthesis. Relevance The high initial stability of the Option 3000 stem justified the clinical use of the new implant. More than 100 implantations in the last three years, with very good preliminary clinical results, support the preclinical findings.

Objective comparison of image quality and dose between conventional and synchrotron radiation mammography

The shape of the energy spectrum produced by an x-ray tube has a great importance in mammography. Many anode-filtration combinations have been proposed to obtain the most effective spectrum shape for the image quality-dose relationship. On the other hand, third generation synchrotrons such as the European Synchrotron Radiation Facility in Grenoble are able to produce a high flux of monoenergetic radiation. It is thus a powerful tool to study the effect of beam energy on image quality and dose in mammography. An objective method was used to evaluate image quality and dose in mammography with synchrotron radiation and to compare them to standard conventional units. It was performed systematically in the energy range of interest for mammography through the evaluation of a global image quality index and through the measurement of the mean glandular dose. Compared to conventional mammography units, synchrotron radiation shows a great improvement of the image quality-dose relationship, which is due to the beam monochromaticity and to the high intrinsic collimation of the beam, which allows the use of a slit instead of an anti-scatter grid for scatter rejection.

First human transvenous coronary angiography at the European Synchrotron Radiation Facility

The first operation of the European Synchrotron Radiation Facility (ESRF) medical beamline is reported in this paper. The goal of the angiography project is to develop a reduced risk imaging technique, which can be used to follow up patients after coronary intervention. After the intravenous injection of a contrast agent (iodine) two images are produced with monochromatic beams, bracketing the iodine K-edge. The logarithmic subtraction of the two measurements results in an iodine enhanced image, which can be precisely quantified. A research protocol has been designed to evaluate the performances of this method in comparison with the conventional technique. Patients included in the protocol have previously undergone angioplasty. If a re-stenosis is suspected, the patient is imaged both at the ESRF and at the hospital with the conventional technique, within the next few days. This paper reports the results obtained with the first patients. To date, eight patients have been imaged and excellent image quality was obtained.

Research at the European Synchrotron Radiation Facility medical beamline

The application of synchrotron radiation in medical research has become a mature field of research at synchrotron facilities worldwide. In the relatively short time that synchrotrons have been available to the scientific community, their characteristic beams of UV and X-ray radiation have been applied to virtually all areas of medical science which use ionizing radiation. The ability to tune intense monochromatic beams over wide energy ranges differentiates these sources from standard clinical and research tools. At the European Synchrotron Radiation Facility (Grenoble, France), a major research facility is operational on an advanced wiggler radiation beamport, ID17. The beamport is designed to carry out a broad range of research ranging from cell radiation biology to in vivo human studies. Medical imaging programs at ID17 include transvenous coronary angiography, computed tomography, mammography and bronchography. In addition, a major research program on microbeam radiation therapy is progressing. This paper will present a very brief overview of the beamline and the imaging and therapy programs.

In vivo K-edge imaging with synchrotron radiation

We present in this paper two imaging techniques using contrast agents assessed with in vivo experiments. Both methods are based on the same physical principle, and were implemented at the European Synchrotron Radiation Facility medical beamline. The first one is intravenous coronary angiography using synchrotron radiation X-rays. This imaging technique has been planned for human studies in the near future. We describe the first experiments that were carried out with pigs at the ESRF. The second imaging mode is computed tomography using synchrotron radiation on rats bearing brain tumors. Owing to synchrotron radiation physical properties, these new imaging methods provide additional information compared to conventional techniques. After infusion of the contrast agent, it is possible to derive from the images the concentration of the contrast agent in the tumor area for the computed tomography and in any visible vessel for the angiography method.

Fixed-exit monochromator for computed tomography with synchrotron radiation at energies 18-90 keV

A fixed-exit monochromator has been constructed for computed tomography (CT) studies at the Medical Beamline of the European Synchrotron Radiation Facility. A non-dispersive pair of bent Laue-type crystals is used, and the first crystal is water-cooled. The monochromator operates at energies from 18 to 90 keV, and the maximum width of the beam is 150 mm. The performance of the monochromator is studied with respect to the beam intensity and energy distributions, and a close agreement is found between the calculated and experimental results. The intensity is between 10(9) and 10(10) photons s(-1) mm(-2) under typical operating conditions. The harmonic content of a 25 keV beam is about 30% at the minimum wiggler gap of 25 mm (field 1.57 T) and decreases by an order of magnitude when the gap is increased to 60 mm (field 0.62 T). The experimental set-up for CT studies includes dose monitors, goniometers and translation stages for positioning and scanning the object, and a 432-element linear-array Ge detector. Examples from phantom studies and in vivo animal experiments are shown to illustrate the spatial resolution and contrast of the reconstructed images.

PhaG-mediated synthesis of Poly(3-hydroxyalkanoates) consisting of medium-chain-length constituents from nonrelated carbon sources in recombinant Pseudomonas fragi

Recently, a new metabolic link between fatty acid de novo biosynthesis and biosynthesis of poly(3-hydroxy-alkanoate) consisting of medium-chain-length constituents (C(6) to C(14)) (PHA(MCL)), catalyzed by the 3-hydroxydecanoyl-[acyl-carrier-protein]:CoA transacylase (PhaG), has been identified in Pseudomonas putida (B. H. A. Rehm, N. Krüger, and A. Steinbüchel, J. Biol. Chem. 273:24044-24051, 1998). To establish this PHA-biosynthetic pathway in a non-PHA-accumulating bacterium, we functionally coexpressed phaC1 (encoding PHA synthase 1) from Pseudomonas aeruginosa and phaG (encoding the transacylase) from P. putida in Pseudomonas fragi. The recombinant strains of P. fragi were cultivated on gluconate as the sole carbon source, and PHA accumulation to about 14% of the total cellular dry weight was achieved. The respective polyester was isolated, and GPC analysis revealed a weight average molar mass of about 130,000 g mol(-1) and a polydispersity of 2.2. The PHA was composed mainly (60 mol%) of 3-hydroxydecanoate. These data strongly suggested that functional expression of phaC1 and phaG established a new pathway for PHA(MCL) biosynthesis from nonrelated carbon sources in P. fragi. When fatty acids were used as the carbon source, no PHA accumulation was observed in PHA synthase-expressing P. fragi, whereas application of the beta-oxidation inhibitor acrylic acid mediated PHA(MCL) accumulation. The substrate for the PHA synthase PhaC1 is therefore presumably directly provided through the enzymatic activity of the transacylase PhaG by the conversion of (R)-3-hydroxydecanoyl-ACP to (R)-3-hydroxydecanoyl-CoA when the organism is cultivated on gluconate. Here we demonstrate for the first time the establishment of PHA(MCL) synthesis from nonrelated carbon sources in a non-PHA-accumulating bacterium, employing fatty acid de novo biosynthesis and the enzymes PhaG (a transacylase) and PhaC1 (a PHA synthase).

Dielectrophoretic sorting of particles and cells in a microsystem

There are highly sensitive analytical techniques for probing cellular and molecular events in very small volumes. The development of microtools for effective sample handling and separation in such volumes remains a challenge. Most devices developed so far use electrophoretic and chromatographic separation methods. We show that forces generated by ac fields under conditions of negative dielectrophoresis (DEP) can also be used. Miniaturized electrode arrays are housed in a microchannel and driven with high-frequency ac. A laminar liquid flow carries particles past the electrodes. Modification of the ac drive changes the particle trajectories. We have handled latex particles of micrometer size and living mammalian cells in a device which consists of the following four elements: a planar funnel which concentrates particles from a 1-mm-wide stream to a beam of about 50-micron width, an aligner which narrows the beam further and acts to break up particle aggregates, a field cage which can be used to trap particles, and a switch which can direct particles into one of two output channels. The electrodes are made from platinum/titanium and indium tin oxide (ITO) on glass substrates. Particle concentration and switching could be achieved for linear flow velocities up to about 10 mm s-1. The combination of this new method with high-performance optical detection offers prospects for miniaturized flow cytometry.