Increasing the field of view in grating based X-ray phase contrast imaging using stitched gratings.

Grating based X-ray differential phase contrast imaging (DPCI) allows for high contrast imaging of materials with similar absorption characteristics. In the last years' publications, small animals or parts of the human body like breast, hand, joints or blood vessels have been studied. Larger objects could not be investigated due to the restricted field of view limited by the available grating area. In this paper, we report on a new stitching method to increase the grating area significantly: individual gratings are merged on a carrier substrate. Whereas the grating fabrication process is based on the LIGA technology (X-ray lithography and electroplating) different cutting and joining methods have been evaluated. First imaging results using a 2×2 stitched analyzer grating in a Talbot-Lau interferometer have been generated using a conventional polychromatic X-ray source. The image quality and analysis confirm the high potential of the stitching method to increase the field of view considerably.

Intracellular cytokine patterns in Behçet's disease in comparison to ankylosing spondylitis--influence of treatment with interferon-alpha2a.

OBJECTIVE: Treatment of Behçet's disease (BD) with human recombinant interferon-alpha2a (IFN-alpha2a) has proven clinically effective. The mechanism of action is unknown. This is the first study investigating the influence of IFN-alpha2a on intracellular cytokines in T-cells in patients with BD in comparison to healthy controls and to patients with ankylosing spondylitis (AS). METHODS: Cytokine expression of T-cells was investigated in 10 patients with BD before and 4 and 12 weeks after initiation of treatment with IFN-alpha2a. 10 patients with AS and 10 healthy individuals served as controls. Peripheral blood mononuclear cells were assayed by flow cytometry for the cell surface markers CD3, CD8 and CD4 and for the intracellular cytokines interleukin 2 (IL 2), tumor necrosis factor-alpha (TNF-alpha), interferon-gamma (IFN-gamma) and interleukin 4 (IL 4). RESULTS: The fraction of CD3+ and CD4+ T-cells producing IL 2 was significantly lower in untreated BD and AS patients compared to healthy controls (p = 0.02 and 0.007). However, the number of IFN-g-producing CD3+ T-cells in untreated BD patients was elevated in comparison to both control groups (p = 0.05). T-cell cytokine analysis of BD patients revealed a significant increase of IL 2-production in T-cells during IFN-alpha2a treatment (p < 0.001). CD4+ T-cells producing IFN-gamma and TNF-alpha increased significantly (p = 0.002 and p = 0.01). CONCLUSION: In BD and AS, CD3+ and CD4+ T-cells producing IL 2 are reduced. This may hint at a similarity in the pathogenesis of these HLA-class I-associated disorders. IFN-alpha2a induces restoration of IL 2-production in patients with BD which is likely to be one mechanism of action of IFN-alpha2a.

Cytokines, cytokine antagonists and soluble adhesion molecules in patients with ocular Behçet's disease treated with human recombinant interferon-alpha2a. Results of an open study and review of the literature.

OBJECTIVE: To elucidate the influence that interferon-alpha exerts on the cytokine network in active ocular Behçet's disease (BD). METHODS: Fifty patients with active ocular BD were treated with human recombinant interferon-alpha2a (rhIFN-alpha2a). Serum was analysed for the presence of IL-10, TNF-alpha, IL-8, IL-6, sIL-2R, IFN-gamma, IFN-alpha, IL-12, IL-4, sTNFRI (p55), sTNFRII (p75), IL-1RA, G-CSF, sE-selectin, sVCAM-1, sICAM-1 and neopterin before initiation of and at several time points during IFN treatment and compared to 21 healthy controls. RESULTS: The levels of IFN-alpha IL1-RA and sTNFRII were significantly increased in the patients at baseline in comparison to healthy controls. During treatment with rhIFN-alpha2a, when remission was achieved as defined by the scoring system used, a significant increase in levels of IFN-alpha, IL-2R, TNF-alpha, sTNF-RII, sICAM-1, sVCAM-1, neopterin in the serum was observed, with a tendency towards increased IL-1RA as well. In contrast, leuko- and thrombocyte counts and sE-selectin serum levels significantly decreased. Positive correlations were found between IFN dosage or serum levels and sVCAM-I, neopterin, sTNF-RII and sIL-2R, between sVCAM-1, sIL-2R, TNF-alpha, sTNF-RII and neopterin, sICAM-I and sVCAM-1, sIL2-R and sTNF-RII, and, finally, between sIL2-R and sICAM-I. CONCLUSIONS: IFN-alpha exerts diverse influences mainly on cytokine antagonists and soluble adhesion molecules. Because sTNF-RII and IL-1RA were increased by IFN-alpha treatment, these might be interesting alternative treatment options in refractory BD. Some of the side-effects of IFN-alpha may be caused by activation of monocytes, which is reflected by an increase in neopterin serum levels.

[The action of flumazenil in combination with fentanyl on spontaneous respiration]. / Die Wirkung von Flumazenil in Kombination mit Fentanyl auf die Spontanatmung.

Whereas the efficacy of flumazenil (Fl) for improving vigilance in the presence of other benzodiazepine agonists (BZA) is undoubted, its effect on BZA- and/or opioid agonists (OA)-induced respiratory depression is the subject of controversies. Some authors describe an improvement of a midazolam (Mi)-induced increase in paCO2, whereas others cannot find any influence on diazepam-induced respiratory depression. In two studies in which Fl was used to antagonize Mi/Fentanyl (Fe) anaesthesia we found even worse oxygen saturation values than with placebo (Pl). All our previous studies indicate a slight intrinsic activity of Fl on respiration in the presence of opioids. We therefore investigated the influence of Fl and Pl on expiratory pCO2 and oxygen saturation (SAT). METHODS. A group of 15 male, healthy volunteers aged 20-30 years gave written informed consent to participate in this double blind study, which was approved by our Institutional Review Board. Each subject received 3 micrograms/kg body wt. Fe + 0.5 mg Fl and 1 week later 3 micrograms/kg body wt. Fe + 5 ml NaCl 0.9% (Pl) i.v., in random order. They were undisturbed and breathed spontaneously. The following parameters were measured: SAT, pCO2 and heart rate (HR) continuously, using a pulse oximeter (SAT, H) and CO2 infrared absorption monitor (Oscar, Messrs., Datex). The blood pressure was recorded before and after a 5-min preinjection period (baseline) and at the end of the procedure (25 min). The data were stored in a microcomputer (Multitalent, Messrs. ZAK) and transmitted to a PC after each trial. STATISTICS. The groups were compared with the Wilcoxon rank sum test. P less than 0.05 is significant. RESULTS. In trials 1 and 2 there was an increase of pCO2 and a drop in SAT. The changes in pCO2 and SAT were more pronounced after Fe+Fl in 12 subjects (80%), as against 1 subject with the opposite result. There were 2 subjects who showed no difference between trials 1 and 2. The combination of Fe and Fl caused significantly higher increases in pCO2 (P = 0.007) and more pronounced decreases in SAT (P = 0.04) than Fe and Pl. DISCUSSION. These results indicate a slight enhancement of Fe-induced respiratory depression by Fl. In a previous study it could be shown that Fl antagonized the respiratory depressive effect of Mi, but baseline paCO2 was not completely recovered. In previous studies respiratory function impaired by Mi+Fe was initially improved by Fl, but rebound effects on SAT were observed, which were more pronounced than those after Pl. Therefore, respiratory function must be closely monitored in Fl-antagonized patients after Mi/Fe anaesthesia.