[Frequency, relevance, causes of and strategies for prevention of medication errors]

Drug therapy has led to major advances in medicine. The beneficial effects of drug therapy are coupled with the inevitable risk of adverse drug reactions especially in elderly patients. Many adverse drug reactions are preventable. The electronic health card that will be introduced in Germany starting in 2006 is designed to support electronic decision support to prevent medication errors. Studies have demonstrated that CPOES can reduce medication errors by 80%. The necessary steps to improve medication safety in Germany are outlined and discussed.

Altered CD46-mediated T cell co-stimulation in haemodialysis patients

While most of our understanding of immune dysfunction in dialysis patients involves alterations in CD28-CD80/86 signalling, nothing is known of CD46-mediated co-stimulation of T cells in these patients. Because C3b/C4b bind to CD46 and complement activation occurs during haemodialysis (HD), we addressed whether CD46-mediated T cell activation is altered in HD (n = 9), peritoneal dialysis (PD) (n = 10) and predialysis patients (n = 8) compared to healthy controls (HC) (n = 8). T cell surface markers, T cell proliferation and interleukin (IL)-10 production were studied in CD4(+)T cells. In addition, CD46 splice-variants and IL-10 promoter gene polymorphisms were studied by reverse transcription (RT) or amplification refractory mutation system-polymerase chain reaction (ARMS-PCR), respectively. In all uraemic patients, irrespective of the stage of renal insufficiency or dialysis modality, a significant increase in the percentage of CD25 positivity in naive CD4(+)T cells was found (64% +/- 21%versus 23% +/- 18%, P < 0.001). Lymphocytes of HD patients proliferated in greater numbers and produced more IL-10 after co-stimulation with anti-CD46 than after co-stimulation with anti-CD28. This was also found in CD4(+)T cells of PD patients, albeit to a lesser extent. In contrast, with T cells of predialysis patients and of HC, co-stimulation via CD28 was more efficient. The observed alterations in T cell proliferation and IL-10 production were associated neither with CD46 splice variants nor with IL-10 promoter gene polymorphisms. Lymphocytes of HD patients show an increased response on CD46 co-stimulation. These data suggest that ongoing complement activation in HD patients may lead to alterations in acquired immunity.

Unilaterally applied stimuli in a frequency discrimination task are represented bilaterally in primary somatosensory cortex

Psychophysical studies have shown that there is somatotopically organized interaction in tasks involving somatosensory memory. In order to test the hypothesis that the ipsilateral somatosensory cortex contributes to the psychophysically demonstrated interaction, neuromagnetic steady-state responses induced by vibro-tactile stimuli were investigated in a frequency discrimination task. Subjects were requested to indicate whether two stimuli (first and test stimulus) presented subsequently at the index finger of one hand differed with respect to frequency. An interference stimulus interpolated between both stimuli was applied at the little or the index finger of either the left or right hand. Results show that in the present memory task, bilateral activation was found mainly for the test stimulus although stimuli were applied uni-laterally. As revealed by dipole analysis, sources ipsilateral to the side of stimulation were predominantly located in primary somatosensory cortex.

Disseminierte intravasale Gerinnung, Perimyokarditis und bilaterales Pleuraempyem bei adultem Still-Syndrom

HISTORY

A 21-year-old man was admitted to the hospital because of high fever, arthralgias and myalgias. One week before he was treated with penicillin G orally because of cough and sore throat.

PHYSICAL EXAMINATION

The critically ill patient presented with a red throat and cervical lymphadenopathy. Lung auscultation revealed reduced respiratory sounds at both base, heart auscultation revealed a pericardial friction rub. Dermatologic examinations were normal.

INVESTIGATIONS

Laboratory findings were notable for anemia, thrombopenia and leukocytosis, disseminated intravascular coagulation and markedly elevated CRP (309 mg/l). Electrogram showed inferior and lateral ST segment depression. Echocardiography showed pericardial effusion. Chest CT scan revealed bilateral pleural effusion, a left-sided small infiltrate and enlarged mediastinal lymph nodes. Abdominal ultrasound confirmed hepatosplenomegaly and ascites.

TREATMENT AND CLINICAL COURSE

A diagnosis of parapneumonic bilateral pleural empyema, perimyocarditis and disseminated intravascular coagulation was made. Despite institution of empiric antibiotic therapy, no clinical improvement was observed. After exclusion of infectious, autoimmune or malignant disease, clinical and laboratory data, especially marked hyperferritinemia, helped to establish the diagnosis of adult-onset Still's disease. Immunosuppressive treatment with prednisolone and azathioprin resulted in remission.

CONCLUSION

Adult-onset Still's disease is a rare inflammatory disorder of unknown origin, which may affect multiple organs. The diagnosis is based on a diagnostic score, which includes a number of clinical and laboratory findings, published by Yamaguchi in 1992. Marked hyperferritinemia represents an additional diagnostic clue to the disease.

Trichosporon asahii infection of a dialysis PTFE arteriovenous graft

Trichosporon species are the causative agents of superficial skin infections, such as white piedra. Immunocompromised hosts, particularly those with underlying hematological malignancy, are at risk of developing invasive infection, which usually progresses to disseminated life-threatening disease. Peritonitis caused by Trichosporon has been described in end-stage renal disease patients treated with continuous ambulatory peritoneal dialysis. Here, we report on a Trichosporon infection of an arteriovenous graft in a patient on chronic hemodialysis. The infection was successfully treated with fluconazole and total surgical resection of the graft.

Small vessel stents for intracranial angioplasty: in vitro evaluation of in-stent stenoses using CT angiography

Our aim was to determine whether CT angiography is suitable for the evaluation of in-stent restenoses in small vessel stents for intracranial angioplasty. Therefore, we simulated stenoses with degrees of 25, 50, 75 and 90% in a total of 12 stents with different designs (MEDTRONIC AVE; ABBOT BioDivYsio, GUIDANT Neurolink, TERUMO Tsunami, COOK V-Flex Plus) and sizes (3.0 mm, 4.0 mm). For each stenosis, the apparent stenotic degree (ASD) was measured by CT angiography. Subjective (viewing at the CT images) and objective (acquisition of a density profile) evaluations were made after the stents were filled with a solution of 0.9% NaCl and with a diluted contrast medium. It was not possible to visualize the patent lumen in any of the stenotic stent segments by viewing at the CT images. After objective evaluation, the degree of the stenoses was generally overestimated. In the group with the 3.0-mm stents, ASD ranged from 73.6 to 100% in 25% degree stenoses. With the exception of one stent, stenoses with a degree of more than 25% appeared as vessel obstruction (ASD = 100%) in the 3.0-mm group. In the 4.0-mm group, the mean ASD was 60% for 25% degree stenoses, 76% for 50% degree stenoses, 91% for 75% degree stenoses and 96% for 95% degree stenoses. The minimum diameter of stents for differentiation between in-stent restenosis and vessel occlusion using CT angiography is 4.0 mm. In CT angiography, the degrees of in-stent stenoses are generally overestimated. The evaluation of in-stent restenoses only seems to be possible when CT angiographic images before and after contrast application are evaluated objectively by density profiles.

Impact of donor dopamine on immediate graft function after kidney transplantation

Optimizing medical donor management may have a considerable impact on transplantation outcome. This study investigated the effect of donor dopamine on initial graft function in renal allograft recipients, involving 254 consecutive recipients of a cadaver kidney, aged 18-74 years, transplanted between 1990 and 2003. Immunosuppression was based on cyclosporine. Patients were grouped according to donor use of dopamine during intensive care. Delayed graft function (DGF), and serial creatinine concentrations were compared between the groups. Dopamine-treated and -untreated donors were very similar regarding hemodynamics and renal function. Delayed graft function occurred in 47/158 treated and 48/96 untreated kidneys (p = 0.001). Donor dopamine was associated with a more rapid decrease of s-creatinine, which became obvious on the first postoperative day. Of patients in the treated and untreated group, respectively, 81.9% and 65.8% reached a s-creatinine level less than 2 mg/dL during the first month (p = 0.005). Donor dopamine remained predictive of a normalized s-creatinine level [HR 1.71; 95% CI 1.22-2.41] after controlling for confounding factors by multivariate Cox regression. Donor dopamine is associated with improvements of initial graft function after kidney transplantation. The beneficial effect of dopamine is achievable without side-effects for the recipients, and correlates with superior long-term graft survival.

The musician's brain: functional imaging of amateurs and professionals during performance and imagery

We compared activation maps of professional and amateur violinists during actual and imagined performance of Mozart's violin concerto in G major (KV216). Execution and imagination of (left hand) fingering movements of the first 16 bars of the concerto were performed. Electromyography (EMG) feedback was used during imagery training to avoid actual movement execution and EMG recording was employed during the scanning of both executed and imagined musical performances. We observed that professional musicians generated higher EMG amplitudes during movement execution and showed focused cerebral activations in the contralateral primary sensorimotor cortex, the bilateral superior parietal lobes, and the ipsilateral anterior cerebellar hemisphere. The finding that professionals exhibited higher activity of the right primary auditory cortex during execution may reflect an increased strength of audio-motor associative connectivity. It appears that during execution of musical sequences in professionals, a higher economy of motor areas frees resources for increased connectivity between the finger sequences and auditory as well as somatosensory loops, which may account for the superior musical performance. Professionals also demonstrated more focused activation patterns during imagined musical performance. However, the auditory-motor loop was not involved during imagined performances in either musician group. It seems that the motor and auditory systems are coactivated as a consequence of musical training but only if one system (motor or auditory) becomes activated by actual movement execution or live musical auditory stimuli.

Acute and chronic endocrine effects of noise: Review of the research conducted at the Institute for Water, Soil and Air Hygiene

This is a review of the research into endocrine effects of noise since the early 1980s at the Institute for Water, Soil and Air Hygiene. According to our knowledge, no other group has studied systematically the endocrine effects of acute and chronic noise exposure. Mechanisms of acute noise-induced stress reactions as well as long-term increase of stress hormones in animal and persons under chronic noise exposure were studied. Our theoretical background was Henry's psychophysiological stress model with the two reaction alternatives : (i) The fight-flight reaction, characterised by an increase in adrenalin and noradrenaline (ii) The defeat reaction with increased cortisol. Extremely intense acute noise exposure near the threshold of pain caused an increased release of cortisol from the suprarenal cortex but acute noise exposure with levels between 90 and 100 dB(A) caused an increase of catecholamines. Non-habituated noise increased primarily the release of adrenalin from the suprarenal medulla, whereas habituated noise caused a chronic increase of noradrenaline from the sympathetic synapses under longterm noise exposure at work. Environmental noise exposure (Leq >/= 60 dB(A)) caused catecholamine increase if activities such as conversation, concentration, recreation etc were disturbed through noise. In sleeping persons, traffic noise with only Leq >/= 30 dB (A) and Lmax >/= 55 dB(A) caused significant acute increase of cortisol, which developed into chronic increase if the noise exposure was repeated consistently. Parallel to cortisol, chronic noradrenaline increase was also observed. Based upon the empirical results, a noise stress model was developed which is a first step forward in the theoretical understanding of endocrine noise effects.

Detection and follow-up of homonymous visual field defects - perimetric essentials for evaluation of spontaneous recovery

Clinical detection and follow-up of homonymous visual field defects require appropriate perimetric procedures: since postgeniculate lesions are usually characterised by absolute scotomata, time consuming threshold methods can be replaced by supraliminal strategies with comparatively high stimulus densities. Compared with equidistant rectangular grids, a centripetal stimulus condensation represents the physiological conditions more adequately and thus is more effective. It allows one to differentiate central changes of the visual field, like macular sparing or splitting, which also interfere with reading performance. This procedure requires test points to be located to either side of the vertical meridian, rather than directly on it. Multimodal assessment of visual subfunctions (using static, kinetic or colour test points, random dot patterns or optokinetic stimulation) specifies the effect of the lesion in different channels or regions of the visual pathways. Automation of perimetric procedures and continuous monitoring of fixation are important tools, enhancing the quality of examination and follow-up. The above mentioned psychophysical techniques for detection of functional defects and documentation of eventual recovery, as well as matching neuroimaging findings, are demonstrated by illustrative cases.

Feature-specific electrophysiological correlates of texture segregation

Discrimination between a figure and its surround is an important first step of pattern recognition. This discrimination usually relies, as a first step, on the detection of borders between a figure and its surround, for example based on spatial gradients in luminance, colour, or texture. There is evidence that neurones in the visual cortex are specifically activated by segregation between textures, but the relation between segregation based on different types of features such as colour, luminance, and motion is unclear. Evoked EEG potentials specific to texture segregation were investigated in 17 observers in two separate experiments and by means of functional magnetic resonance imaging in a separate study (Fahle et al., in preparation). Differences in either luminance, colour, line orientation, motion, or stereoscopic depth defined a checkerboard pattern. Patterns defined by each of these features elicited segregation-specific potentials. In contrast to earlier reports (Vision Research 37 (1997) 1409), however, we find pronounced differences between the segregation-specific potentials evoked through different features, especially regarding their peak latencies. The topographical distribution of the activity evoked reveals different polarities and partly specific locations for different stimulus features, indicating the existence of different processors for texture segregation based on different features.

Endovascular stent-graft placement versus conventional open surgery in infrarenal aortic aneurysm: a prospective study on acute phase response and clinical outcome

BACKGROUND

For the treatment of aortic aneurysm, stent-graft implantation is an alternative method to open surgery. There is no study comparing both methods with regard to endotoxaemia, the acute phase cascade, and clinical outcome.

METHODS

In this prospective study, we enrolled 40 patients (34 males, 6 females; mean age 72.1+/-7.5 [58-92] years) with infrarenal abdominal aortic aneurysm who underwent aortic surgery. Comparable groups of patients were treated with open (n=20) or endovascular (n=20) stent-graft implantation. To characterize the inflammatory response, plasma levels of endotoxin, endotoxin-neutralizing capacity (ENC), interleukin-6 (IL-6), C-reactive protein (CRP), and white blood cell count were determined. In all patients, measurements were performed on admission, skin suture, 4 h and from the first to fifth postoperative day. As parameters for the clinical outcome, we assessed daily temperature, lung function, pain, duration of postoperative hospital stay, and morbidity. Wilcoxon rank test was used for statistical analysis.

RESULTS

In both groups, a significant increase of endotoxin plasma levels and a decrease of ENC was found already after skin incision. IL-6 levels peaked 4 h postoperatively in both groups, whereas CRP rose at the first postoperative day, reaching a maximum at day 2. Conventionally operated patients had significantly higher plasma levels of endotoxin, IL-6, and CRP and lower ENC during and after surgery than patients with stent-graft implantation. Moreover, patients with endovascular stent grafting had significant less postoperative pain, less restriction of total vital capacity, a shorter hospital stay, and a lower morbidity.

CONCLUSIONS

Endovascular stent grafting of infrarenal aortic aneurysm seems to be superior not only in terms of the inflammatory response but also in overall clinical outcome.

Polymorphisms of the ICAM-1 gene are associated with inflammatory bowel disease, regardless of the p-ANCA status

The intercellular adhesion molecule-1 (ICAM-1) is of paramount importance for the initiation and propagation of various inflammatory conditions. An increased frequency of allele R241 of the ICAM-1 gene was previously described in p-ANCA-negative as compared to p-ANCA-positive ulcerative colitis and vice versa in Crohn's disease. One hundred sixteen healthy unrelated controls, 121 patients with ulcerative colitis, and 96 patients with Crohn's disease were genotyped for two polymorphisms of the ICAM-1 gene (R/G241, exon 4; and K/E469, exon 6), employing dot-blot hybridization and stratified according to their p-ANCA status. When compared with the control group the frequency of the allele R241 (P = 0.024) and the heterozygous genotype R/G241, P = 0.032) were significantly increased in ulcerative colitis, whereas the homozygous genotype G/G241 was found less frequently (P = 0.022). The heterozygous genotype K/E469 was observed less frequently (P = 0.001 and 0.037, resp.) than the homozygous genotype E/E469, which was more frequent in Crohn's disease and ulcerative colitis (P = 0.002 and 0.012, respectively). Further significant differences concerning the allele or genotype distribution were not observed. After stratification for the p-ANCA status significant differences concerning the frequencies of both the R241 and the E469 alleles were not detected when p-ANCA-positive inflammatory bowel disease and p-ANCA-negative inflammatory bowel disease were compared. Ulcerative colitis and Crohn's disease are associated with polymorphisms of the ICAM-1 gene, which might therefore represent a functional candidate gene. However, the observed associations are independent of the p-ANCA status.

Dynamic organization of the somatosensory cortex induced by motor activity

Intensive and long-lasting experience of altered sensory input induces permanent changes in the functional organization of the somatosensory cortex. In addition, an increasing body of evidence suggests the existence of dynamic, short-term and task-dependent adaptation of representational maps within somatosensory cortex. It is hypothesized that somatosensory maps can, not only, be acquired within a short period of time, but might also be set up during periods of training related to specific tasks and subsequently activated dynamically upon performance of that particular task. In order to test this hypothesis we studied the functional organization of somatosensory cortex for a heavily overlearned and frequently performed task for which no new acquisition of a sensory map had to be assumed. To this end, the functional organization of somatosensory cortex for handwriting was compared with the organization during rest in healthy humans. Functional organization of the somatosensory cortex was assessed using non-invasive, neuromagnetic source imaging based on tactile stimulation of the thumb (D1) and little finger (D5) during writing and rest. In different blocks, subjects wrote with their right, dominant and their left hand, respectively. During writing, D1 and D5 of the writing hand were stimulated. To test the reliability of our results all measurements were repeated after 1 week. It was found that amplitudes of somatosensory evoked magnetic fields with latencies of 45 ms were reduced during writing compared with rest. This finding is in accordance with the sensorimotor gating effect. Using source localization we could show that cortical representations of D1 and D5 are more distant during writing with either hand compared with rest. Our data suggest that somatosensory cortical maps undergo rapid modulation depending on task-specific involvement of sensory processing in daily-life overlearned movements. As it is unlikely that a new sensory map is always acquired when a frequently used task such as writing is performed, we suggest that somatosensory cortex switches between different, concurrently pre-existing maps depending on actual requirements. Task-dependent activation of pre-existing maps might be a powerful mechanism to optimize stimulus processing.

Automation, task difficulty, and aircrew performance

The effects of an automated system on team processes and performance were assessed in a laboratory simulation. Two-person crews were required to fly a complex emergency-response scenario under conditions of low and high workload. These flights were completed with or without the aid of an autopilot. The results indicated that the autopilot was effective in reducing subjective workload. However, the automation was associated with improved performance on only 1 of 4 performance measures. Furthermore, it was observed that problem-solving performance was worse in the autopilot condition during the high-workload flights. Investigation of crew process data indicated that workload savings afforded by the autopilot might have been invested in more explicit coordination. The results are discussed in terms of their implications for military aviators' performance, system design, and team training.

The distribution of mislocalizations across fingers demonstrates training-induced neuroplastic changes in somatosensory cortex

The somatosensory system has been shown to alter its cortical activation patterns in reaction to changes in the attended sensory input to certain body parts. Whether these modifications in the functional organization of the somatosensory cortex of humans also result in perceptual changes has rarely been investigated. Here we used near-threshold tactile stimuli to the center of the fingertips to evoke mislocalizations to fingers other than the stimulated. In healthy untrained subjects, the distribution of the mislocalizations from each of the fingers was different from a distribution expected if the subjects were purely guessing the position of the stimulus. The digits next to the stimulated one receive a higher number of mislocalizations than digits further away from the stimulated digits. This decrease can be accounted for by digit-overlapping receptive fields in combination with the sequential representation of the digits in the primary somatosensory cortex. In a second experiment subjects received 20 h of simultaneous stimulation of the left thumb and little finger in the context of a perceptual task. For both hands, the distribution of mislocalization from these fingers was analyzed at the beginning and the end of the training. For the left hand, the number of assigned mislocalizations to the most distant neighbor digit (i.e., the simultaneously stimulated digit in the training) increased while the number of mislocalizations toward the direct neighboring digit decreased with the training. This change did not occur in the untrained right hand, or in the untrained subjects. We conclude that the distribution of mislocalization to fingers other than the stimulated can be used to investigate perceptual changes paralleling training-induced modifications in the activation patterns of the somatosensory cortex.

Treatment of chronic renal allograft rejection in rats with a low-molecular-weight heparin (reviparin)

BACKGROUND

Low-molecular-weight heparin (LMWH) has been shown to prolong survival of rat cardiac allografts independently from immunosuppressive treatment. Furthermore, long-term treatment reduces the development of chronic graft vascular disease after experimental heart transplantation. The aim of the present study was to determine whether treatment with the LMWH reviparin has a beneficial effect on chronic rejection in a rat renal allograft model.

METHODS

Kidneys of Fisher (F344) rats were transplanted into unilaterally nephrectomized Lewis (LEW) recipients. LEW-->LEW isografts served as controls. Animals were treated with cyclosporine (5 mg/kg/d) for the first 10 days. Nephrectomy of the remaining kidney was performed after 10 days. Allografted animals were treated either with reviparin (2 mg/kg/d subcutaneously) for 24 weeks (Allo-24), from week 12 to 24 (Allo-12), or with vehicle for 24 weeks. Proteinuria was determined at regular intervals. Kidneys were harvested after 24 weeks for histomorphological and immunohistochemical evaluation.

RESULTS

No major bleeding complications were observed in reviparin-treated animals. Proteinuria was significantly reduced in allografted animals both by early as well as by late-onset treatment with reviparin. Transplant glomerulopathy was diminished in Allo-24 and in Allo-12 groups compared to vehicle-treated animals, whereas tubulointerstitial inflammation was influenced only in animals immediately treated with reviparin. Immunohistochemical studies demonstrated a marked reduction of renal monocyte and T-cell infiltration as well as expression of MHC II by treatment with reviparin.

CONCLUSIONS

Treatment with the LMWH reviparin significantly improved chronic renal allograft rejection in the F344-to-LEW rat model, both after early and late start of therapy. Although the exact mechanisms of this beneficial effect remain unclear, our data offer a potential new therapeutical approach for prevention of chronic allograft nephropathy.

The Kapandji technique for fixation of distal radius fractures--a biomechanical comparison of primary stability

The goal of this study was to compare Kapandji-K-wiring and established K-wiring techniques of the distal radius fracture for primary stability in a biomechanical model: dorsal K-wiring according to Kapandji using different angles of the K-wire, parallel and diagonal alignment of the K-wires. A new testing system which uses a synthetic material enabled us to carry out the cantilever bending test. By application of a lower load, the Kapandji procedure shows a higher reactive torque and stiffness. A higher reaction force of the other techniques, especially of the parallel wiring, are only observable under high-grade bending stress. Application of the Kapandji procedure with K-wires at a smaller angle to the axis of the radius results in the highest primary stability of the procedures investigated in the essential range of initial deformation.

Therapeutic administration of an endothelin-A receptor antagonist after acute ischemic renal failure dose-dependently improves recovery of renal function

Endothelin (ET) is known to reduce glomerular filtration rate and renal blood flow and is a possible mediator of acute renal failure (ARF). We recently demonstrated that the administration of a very high dose of the ET(A)-receptor antagonist LU 135252 (LU) accelerates recovery from postischemic acute renal failure by an improvement of renal perfusion in a rat model. The aim of this study was to investigate whether this effect of LU is dose dependent. ARF was induced in rats by clamping both renal arteries. Serum creatinine was measured and endogenous creatinine clearance and fractional sodium excretion were calculated up to 4 days after acute ischemia. Rats were treated either with the selective ET(A)-receptor antagonist LU or with vehicle only after reperfusion. LU in doses of 0.5, 1, or 5 mg/kg per day was infused via a femoral vein using an osmotic minipump. Serum creatinine was increased approximately eightfold after induction of ARF. Creatinine clearance decreased from 4.35 +/- 0.26 ml/min before acute renal failure to 0.15 +/- 0.02, 0.54 +/- 0.1, and 1.49 +/- 0.19 ml/min on days 1, 2, and 4 after ischemia (p < 0.05). Fractional sodium excretion increased from baseline 0.77 +/- 0.05% to 7.5 +/- 1.21 % on day 1 and 8.53 +/- 1.34% on day 2 (p < 0.05). Treatment with LU improved kidney function dose relatedly. There was no significant change in creatinine clearance, but compared with controls, with doses of 0.5 mg/kg per day and 1 mg/kg per day (0.28 +/- 0.1, 0.88 +/- 0.22, and 1.93 +/- 0.24 ml/min on days 1, 2, and 4), we noted a significant increase under 5 mg/kg per day (day 1: 0.62 +/- 0.17 ml/min; day 2: 1.38 +/- 0.26 ml/min; and day 4: 2.45 +/- 0.21 ml/min; p < 0.05). Fractional sodium excretion decreased dose-relatedly to a maximally 2.48 +/- 0.58% on day 1 and 2.25 +/- 0.71 % on day 2 after treatment with the highest dose when compared with untreated control rats (p < 0.05). Our data support the hypothesis that ET plays a major role in ARF. It can be concluded from these results that recovery from ischemic ARF is significantly and dose-dependently enhanced by treatment with a selective ET(A)-receptor antagonist.

Two-dimensional angular light-scattering in aqueous NaCl single aerosol particles during deliquescence and efflorescence

We present a new method to analyze two--dimensional angular light--scattering patterns of single aerosol particles by image processing. An asymmetry parameter can be calculated to determine the solid--to--liquid partitioning in micron sized composite particles similar to using temporal light--scattering intensity fluctuations. We use the scattering patterns of the deliquescence of a NaCl crystal to prove the feasibility of the method. In addition we show that even fast processes like the efflorescence from a supersaturated solution droplet can be analyzed where temporal fluctuation analysis fails. We find that efflorescence cannot be described as a time reversed deliquescence. There is indication that during efflorescence a solid shell grows at the surface of the liquid droplet which finally collapses due to mechanical stress.