Search

Most toxic industrial chemicals and chemical warfare agents are hydrophobic and can only be solubilized in organic solvents. However, most reagents employed for the degradation of these toxic compounds can only be dissolved in water. Hence, microemulsions are auspicious media for the decontamination of a variety of chemical warfare agents and pesticides. They allow for the solubilization of both the lipophilic toxics and the hydrophilic reagent. Alkyl oligoglucosides and plant derived solvents like rapeseed methyl ester enable the formulation of environmentally compatible bicontinuous microemulsions. In the present article the phase behavior of such a microemulsion is studied and the bicontinuous phase is identified. Small angle neutron scattering (SANS) and freeze fracture electron microscopy (FFEM) measurements are used to characterize the Structure of the bicontinuous phase and allow for an estimation of the total internal interface. Moreover, also the influence of the co-surfactant (1-pentanol) on the structural parameters of the bicontinuous phase is studied with SANS. (C) 2008 Elsevier Inc. All rights reserved.

The value of CT in the preoperative management of tumors of the sacrum is demonstrated. Essential informations for treatment planning are: involved sacral segment, infiltration of sacral foramina and nerve roots, involvement of the sacroiliac joints, ingression of the lumbar spine, infiltration of the pelvic organs and vessels, sciatic nerve and the dorsal soft tissues. In order to prove the competence of the CT in answering these questions we evaluated the CT-examinations of 30 pat. with 14 primary tumors, 9 metastatic tumors and 7 tumors involving secondary the sacrum. The CT findings were correlated with clinical symptoms and surgical reports in 11 pat., with clinical symptoms alone in 19 pat. There was good correlation in the criterias: location and number of involved segments (8/11, 17/19), infiltr. of SI-joints (11/11), infiltr. of lumbar spine (9/11, 18/19), and infiltr. of pelvic organs (10/11), worse correlation in the criterias: nerve root-involvement (2/11, 3/19), and sciatic nerve-infiltr. (7/11, 15/19). Our conclusions are that CT gives helpful preoperative informations deciding about extent of surgical procedure, and surgical approach. The major problem, however, consist in diagnosis of nerve root and sciatic nerve involvement, therefore in poor prediction of postoperative conservation of neural functions. The knowledge of CT-anatomy of sacrum- and important condition for correct segment-location of the tumor is refreshed by outlines of characteristic segmental CT-sections of the sacrum.

Die Radiologie hat in den letzten Jahrzehnten gewaltige technologische und damit organisatorische Anderungen erlebt. Diese Anderungen erfolgten mehr oder weniger im Gleichklang mit den gesamtstaatlichen Gesundheitsausgaben, wobei allerdings das individuelle frei verfugbare Einkommen im gleichen Zeitraum (1988–2003) doppelt so hoch gestiegen ist. Der Aufwand fur Medizintechnik betragt ca. 3–5% der nationalen Gesundheitsausgaben. Die Radiologie ist damit national, aber auch in einem Zentralkrankenhaus, kein wesentlicher Kostenfaktor. In den letzten Jahren ergab sich eine Zunahme der Schnittbilduntersuchungen um 2–3%, diese umfassen heute schon 30% aller radiologischen Untersuchungen.

The efficacy of DMARD therapy in rheumatoid arthritis (RA) can be judged by radiological analysis. This study aimed to determine the time-dependent progression of joint damage, acute-phase response, and rates of radiologic progression in early DMARD-treated RA patients over 10 years.We evaluated outpatient records, and radiographs of hands and feet of 54 early RA patients on DMARDs for 10 years. Radiographs were quantified by the Larsen method using recently developed quantification software.Radiological damage attenuated, with disease progression from baseline to Year 10 [correlation coefficient (r)=0.95, probability (p)0.001]. Radiographic scores progressed more rapidly during the first 5 years than thereafter. Cumulative erythrocyte sedimentation rate (ESR) was strongly correlated with radiological progression (p0.001, r=0.88).Our findings reveal a higher amount of radiographic RA progression during the first years of DMARD treatment. Thus, our data provide strong evidence for the importance of both early DMARD therapy and continuous radiographic assessments in RA.

The present investigation was a methodological study of a new method of quantification of a series of factors in the transverse dimension of the maxilla including the nose, maxillary bones and dental arches, based on computer tomographic (CT) scanning. The aim was to investigate a series of parameters thought to be relevant in the differential diagnosis of discrepancies in the morphology of this area and probably affected by orthodontic appliances. Based on a standardized CT scanning registration of 10 subjects, a series of points on the scans were identified and then measured in a special cephalometric computer system (linear and angular values). The quantitation was repeated by each observer and inter- and intra-observer differences were calculated. The results demonstrated that virtually all the parameters showed a high degree of reproducibility at both levels and confirmed the statistical suitability of the method described. The method will be used in a series of ongoing studies regarding the morphology and treatment of discrepancies of the midface and therefore supplement the relatively sparse information based on quantitative reports concerning this important anatomical area.

The capability of logical systems to express their own satisfaction relation is a key issue in mathematical logic. Our notion of self definability is based on encodings of pairs of the type (structure, formula) into single structures wherein the two components can be clearly distinguished. Hence, the ambiguity between structures and formulas, forming the basis for many classical results, is avoided. We restrict ourselves to countable, regular, logics over finite vocabularies. Our main theorem states that self definability, in this framework, is equivalent to the existence of complete problems under quantifier free reductions. Whereas this holds true for arbitrary structures, we focus on examples from Finite Model Theory. Here, the theorem sheds a new light on nesting hierarchies for certain generalized quantifiers. They can be interpreted as failure of self definability in the according extensions of first order logic. As a further application we study the possibility of the existence of recursive logics for PTIME. We restate a result of Dawar concluding from recursive logics to complete problems. We show that for the model checking Turing machines associated with a recursive logic, it makes no difference whether or not they may use built in clocks.

Soil samples from under a rainforest, a papaya plantation, a pure Brachiaria humidicola pasture and a B. humidicola/Desmodium ovalifolium sward from the humid tropical Bahia, Brazil, were analyzed for fertility parameters, litter quality, particulate light fraction [ PLF > 100 53 -100 μ m , 100 μm) PLF was of younger age than the finer PLF or whole soil samples. The age of the 53–100 μm PLF was very close to that of stabilized organic matter as indicated by 13C data, its low C-to-N ratio (15–17:1) and its turnover time was about 30 y. The PLF appeared not to consist of one uniform pool and thus may have to be subdivided to be useful for modelling purposes (e.g. active, passive pools and charcoal). The contribution of PLF and above ground litter to total soil N mineralization (anaerobic incubation) was highest in the undisturbed rainforest ( 12 16 % for the PLF/litter, respectively, in the 0–2 cm layer), but much less in the other systems. However, mineralization of PLF from different sources was unpredictably altered by the density agent. Introducing D. ovalifolium into these pastures increased, significantly, the amounts of N in PLF, decreased the C-to-N ratio of PLF and tended to increase, the mineralization potential despite its high lignin and polyphenol content. The combination of δ13C analysis and size/density separations, of surface samples in particular, allowed sensitive detection of changes in soil organic matter dynamics and soil fertility.

A neonate with absent pulmonary valve syndrome was examined by means of echocardiography and magnetic resonance imaging (MRI). MRI provided an excellent evaluation of the intracardial morphology, vessel anatomy, mediastinal structures, and shunt flow; and it was superior to echocardiography for detection of aortopulmonary collaterals and vessel abnormalities. This case report of an uncommon cardiac abnormality confirms that MRI is a useful complementary modality to echocardiography in neonates and is recommended for problems with central pulmonary vessels and their relation to tracheobronchial structures.

This study comprises 76 published judgments by German and Austrian civil courts between 1966 and 1993 concerning liability in the field of radiology. There has been a marked increase in the number of legal proceedings in the 1980's and even more so in the second half of this decade. This is due to an increased tendency to sue doctors without any legal cause in the hope of possible compensation. In 40.8% of the cases the doctor was held liable and required to compensate the patient for personal injury and suffering pain. Most of the cases were related to complications during the examination procedure. The reason most frequently cited by the courts for sentencing doctors was the fact that they did not previously inform the patient adequately about the examination and its possible consequences.

Die Untersuchung des Ober- und Unterkiefers mittels hochauflosender Computertomographie hat sich in den letzten Jahren als Standardverfahren in der implantologischen Diagnostik etabliert. Bei dieser als „Dental-CT“ bezeichnete Methode werden hochaulosende axiale Schichten des Kiefers angefertigt, die mittels geeigneter Software multiplanar reformatiert und auf Hardcopy im Masstab 1:1 dargestellt werden konnen. Dadurch gelingt es storende Artefakte von Metallfullungen auf die Okklusionsebene zu beschranken und eine uneingeschrankte Beurteilbarkeit des Kiefers zu ermoglichen. Daruber hinaus besteht die Moglichkeit navigierte Implantationsverfahren einzusetzen. In zunehmenden Mase wird das Dental-CT nunmehr auch fur die Diagnostik und praoperative Planung bei pathologischen Prozessen im Kieferbereich eingesetzt. Typische Indikationen, neben der praimplantologischen Diagnostik (Knochenangebot), sind retinierte Zahne, zystische und entzundliche Lasionen, Fremdkorperlokalisationen und Trauma. Da bei einer Dental-CT Untersuchung gelegentlich auch Kinder untersucht werden, ist aus strahlenhygienischen Grunden eine Minimierung der Strahlenexposition besonders wichtig. Diese kann durch richtige Anpassung der Untersuchungsprotokolle („low-dose Dental-CT“) einfach erreicht werden, wobei Dosiswerte erreichbar sind, die mit den niedrigen Werten von konventionellen Verfahren (OPTG, Zahnstatus) vergleichbar sind. Ziel dieses Beitrages ist die Untersuchungstechnik und Moglichkeiten der Dental-CT an Hand von Beispielen zu vermitteln. Lernziele: Dental-CT ist ein Standardverfahren in der praimplantologischen Diagnostik Hochauflosende Bildqualitat ist wesentlich und wird durch optimierte Protokolle erreicht Dental-CT ist als erganzendes Verfahren fur die Darstellung von pathologischen Veranderungen im Kieferbereich geeignet Korrespondierender Autor: Imhof H Univ. Klinik fur Radiodiagnostik, Abteilung fur Osteologie, Waehringer Guertel 18–20, 1090, Wien E-Mail: osteo-mr@meduniwien.ac.at

Tumorous lesions of the temporal bone excluding tumors of the cerebellopontine angle (CPA) are relatively rare. The publications of these lesions are mostly in the form of case reports.

Severe (high-energy) spinal injuries are common sequelae of acute traumas. The task of radiology is to establish the radiological diagnosis, classify it, judge stability and instability and lead further radiological evaluation in cases of non-agreement between the radiological diagnosis and the clinical (neurological) findings. While skeletal abnormalities are best diagnosed with spiral CT and to a lesser degree with plain-film radiographs, soft tissue lesions, such as cord injuries or ligament ruptures, are best outlined with emergency MRI. The classification of fractures depends on fracture (trauma)-biomechanics and location. All these efforts are necessary to get the best clinical outcome for the patient.

We propose a method called spatial autocorrelation analysis (SACA) to determine the spatial anisotropy of the trabecular bone in order to investigate osteoporosis. For demonstrating the potential of SACA we first evaluate the method on rectangular, simulated test patterns as a simple model for the anisotropic pore structure of the bone. As a next step towards biomedical application, photographic reference images of human vertebral bone were investigated by SACA. Osteoporotic bone structure could be clearly differentiated from non-osteoporotic sample images. Moreover, for demonstration of the applicability and potential of the method for in vivo characterization of osteoporosis, the microstructure of the human calcaneus was investigated by MR-microimaging on a young healthy male subject and an osteoporotic female. The measurements were performed using a high-field (3T) whole-body MR tomograph equipped with a special, strong head gradient system. The signal was acquired with a surface coil mounted on an in-house-built device for convenient immobilization of the subject's foot. Using a 3D gradient echo sequence a resolution of 0.254 x 0.254 x 2.188 mm3 was achieved in vivo. Selected images were inverted, gradient corrected for the inhomogeneous but sensitive detection by the surface coil, and subsequently analyzed by SACA. The anisotropy of bone structure detected by SACA is a possible candidate for noninvasive determination of the osteoporotic status, potentially complementing standard bone mineral density measurements.

Occupationally used high-frequency vibration is supposed to have negative effects on blood flow and muscle strength. Conversely, low-frequency vibration used as a training tool appears to increase muscle strength, but nothing is known about its effects on peripheral circulation. The aim of this investigation was to quantify alterations in muscle blood volume after whole muscle vibration--after exercising on the training device Galileo 2000 (Novotec GmbH, Pforzheim, Germany). Twenty healthy adults performed a 9-min standing test. They stood with both feet on a platform, producing oscillating mechanical vibrations of 26 Hz. Alterations in muscle blood volume of the quadriceps and gastrocnemius muscles were assessed with power Doppler sonography and arterial blood flow of the popliteal artery with a Doppler ultrasound machine. Measurements were performed before and immediately after exercising. Power Doppler indices indicative of muscular blood circulation in the calf and thigh significantly increased after exercise. The mean blood flow velocity in the popliteal artery increased from 6.5 to 13.0 cm x s(-1) and its resistive index was significantly reduced. The results indicate that low-frequency vibration does not have the negative effects on peripheral circulation known from occupational high-frequency vibration.

Background With high-resolution sonography (US) of joints affected by rheumatoid arthritis (RA) a detailed delineation of intra- and extraarticular soft-tissue abnormalities is possible. Power-Doppler is useful for the analysis of the vascularisation of inflamed tissue. The aim of the study was to evaluate the diagnostic value of Power-Doppler and B-Mode US in context with clinical examinations and conventional radiography. Objectives Methods To date, in 22 patients (5 males, 17 females) with different grades of RA (17 RF+, 5RF-) the wrists and MCP I-V and PIP II-V were scored with sonography (ATL HDI 5000, 5‑12 MHz Transducer, synthetic plastic blocks) with B-Mode and Power-Doppler application in standardised technique. Extension and severity of the inflamed tissue as well as vascularisation were scored. The results were correlated with benchmarks of the clinical and radiologic investigations. Radiographs were assessed according to the Larsen Score. The amount of time of US investigation was measured. Results With sonography, both extension and severity of wrist lesions could be delineated to better advantage than with radiography and clinical examination. This was also true for the MCP joints with the exception of MCP II, where most of the lesions detected by radiography were found. From 484 joints, 29% were found to be abnormal by clinical investigations. Erosions were detected in 26% with radiography, in 37% with sonography. Hypervascularisation was found in 36%. No significant difference of US abnormalities between patient groups with positive and negative RF could be found. A modern state-of-the-art Power Doppler program release is a necessary tool for semi-quantification. A standardised investigation technique with a median amount of time of 18 min provides sufficient quality measures. Conclusion Sonography detects more bone erosions than radiography and clinical examination. It supports the diagnosis of RA manifestations of the hand. References Fitzgerald O, Bresnihan B. Synovial vascularity is increased in rheumatoid arthritis: comment on the article by Stevens, et al.[letter]. Arthritis Rheum. 1992;35:1540–41 Hau M, Schultz H, Tony HP, Keberle M, Jahns R, Haerten R, Jenett M. Evaluation of pannus and vascularization of the metacarpophalangeal and proximal interphalangeal joints in rheumatoid arthritis by high-resolution ultrasound (multidimensional linear array). Arthritis Rheum. 1999;42(11):2303–8 Grassi W, Tittarelli E, Pirani O, Avaltroni D, Cervini C. Ultrasound examination of metacarpophalangeal joints in rheumatoid arthritis. Scand J Rheumatol. 1993;22:243–7

Objective: To explore the effects of rheumatic diseases and glucocorticoids on bone mass a group of patients suffering from systemic lupus erythematosus (SLE, n=18) and rheumatoid arthritis (RA, n=22) were examined. Design: We examined 40 patients and 48 controls with quantitative ultrasound (QUS) and dual-energy X-ray absorptiometry (DXA). Results: QUS (broadband ultrasound attenuation, BUA; speed of sound, SOS) values were found to be significantly lower in patients than in controls (P

There is little information about the interaction between melatonin, sexual steroids and neuroendocrine system in postmenopausal females, even if former research showed that melatonin is clearly involved in human physiology and pathophysiology. We evaluated the overnight urinary excretion of 6-sulfatoxymelatonin (6-SMT) using a radioimmunoassay in 60 postmenopausal women. The group has been divided into patients with insomnia (10), hyperprolactinemia (7), depression (9), obesity (7) and controls (27). Compared to controls 6-SMT values were significantly higher in depressive females. Patients with hyperprolactinemia showed a trend toward a significantly elevated average nocturnal melatonin concentration. Melatonin levels were significantly lower in patients with insomnia and obese postmenopausal females than in controls. Since previous studies described lower melatonin levels in postmenopausal than in premenopausal women, the indication of melatonin therapy, especially for sleep disorders in this collective, can be handled more generously. Melatonin should be prescribed restrictively in patients with depression and in those with hyperprolactinemia. The role of melatonin in obese females remains unclear.

A 37-year-old male patient with no significant past medical history presented with a 6-month history of intermittent epigastric pain which was partially relieved by antacid medication. Gastroscopy showed a peptic ulcer and the biopsies that were taken did not show signs of malignancy. Conservative treatment was initiated, but healing was prolonged, and the epigastric pain persisted. The patient was referred to our department for further diagnosis.

The interaction of melatonin to sterility and anovulation as well as related hormonal disorders has not been sufficiently examined yet. We set out to investigate the interaction between melatonin and hyperprolactinemia, hyperandrogenemia, hypothyreosis and obesity in premenopausal females.We evaluated the overnight urinary excretion of 6-sulfatoxymelatonin (6-SMT) in a group of 155 women using a radioimmunoassay.Melatonin levels in patients with hyperprolactinemia and hyperandrogenemia with normal body mass index are significantly higher compared to matched controls. Obese females without hormonal disorders showed statistically lower 6-sulfatoxymelatonin levels and in hypothyreotic females we found no difference in 6-sulfatoxymelatonin levels compared to controls.Melatonin plays an important role in patients with hormonal disorders such as hyperprolactinemia and hyperandrogenemia. Melatonin should be prescribed restrictively in all sterile patients. In patients with untreated hypothyreosis or obesity, melatonin seems to play a minor part; in those with hyperprolactinemia and hyperandrogenemia additionally to standard sterility treatment light therapy may improve the outcome.

BACKGROUND AND PURPOSE: On cross-sectional and panoramic reformatted images from axial (dental) CT scans of the mandible it may be difficult to identify the inferior alveolar neurovascular bundle (IANB) in patients lacking a clear-cut bony delimitation of the mandibular canal. Dental MR images are comparable to dental CT scans, which directly show the IANB; however, measurements of length may not be reliable owing to susceptibility artifacts and field inhomogeneities in the oral cavity. Therefore, the accuracy of length measurements on dental MR images was compared with that on dental CT scans and direct osteometry. METHODS: Dental T1-weighted MR imaging using a high-resolution turbo gradient-echo sequence and dental CT were performed in six anatomic specimens. The axial scans were reformatted as panoramic and cross-sectional reconstructions on a workstation and characteristic cross sections were obtained from all mandibles. The longest axis in the bucco-lingual and apico-basal directions, the distances from the top of the mandibular canal to the top of the alveolar ridge and from the bottom of the mandibular canal to the base of the mandible, and the diameter of the bone cortex at the alveolar ridge were measured with direct osteometry on the cross sections and compared with measurements on corresponding MR and CT reformatted images. RESULTS: The correlation between direct osteometry and dental MR and CT was strong, except for the bone cortex diameter at the top of the alveolar ridge, where only a moderate correlation was found. Means of comparable length measurements were not significantly different among the three methods. CONCLUSION: The accuracy of length measurements in the jaw bones obtained using dental MR is comparable to that of dental CT and is not significantly different from direct osteometry. Thus, dental MR is a potential alternative to CT for dental imaging.