Zerstörungsfreie Bestimmung von Cholesterol und Collagen in arteriosklerotischen Plaques mittels NIR-Spektroskopie

Eine der häufigsten Todesursachen in den Industrieländern ist nach wie vor der Herzinfarkt infolge sklerotischer Veränderungen der Arterien. Moderne bildgebende Verfahren (Ultraschalltechniken, tomographische Verfahren) ermöglichen die Darstellung der Lumenveränderungen in den Arterien, können jedoch die chemische Zusammensetzung einer arteriosclerotischen Ablagerung (Plaque) nicht wiedergeben. Die Kenntnis der Plaquezusammensetzung wäre jedoch ein wichtiges Kriterium für die Einschätzung der Plaquevulnerabilität und könnte somit therapeutische Entscheidungen unterstützen. Ziel unserer Untersuchungen war es nachzuweisen, ob mittels Nahinfrarot-Spektroskopie die Bestimmung von Komponenten der Arterienwand (Cholesterol, Kollagen) möglich ist. Untersucht wurden 82 verschiedene Arterienareale autoptisch gewonnener humaner Aorten und Modellmischungen. Die NIR-Spektren wurden mit einem FT-Spektrophotometer und drei unterschiedlichen Fasersonden (1.: optisches Fenster d=4mm, 2.: d=1mm, 3.: d=400µm mit rechtwinklig zur Faserrichtung austretendem Meßstrahl) aufgenommen. Die chemische Referenzanalytik erfolgte mittels HPLC, die chemometrische Auswertung mit dem PLS (partial least square) Model. Weiterhin wurde die Eindringtiefe des Meßstrahles in das Gewebe untersucht. Unsere Untersuchungen zeigen, daß die NIR-Spektroskopie ein geeignetes Arbeitsmittel für die quantitative Bestimmung von Arterienwandbestandteilen ist. Für die Realisierung von in-vivo-Untersuchungen mit einem entsprechendem NIR-Katheter müssen jedoch noch viele technische Details geklärt werden

Virus-Induced Type I Interferon Deteriorates Control of Systemic Pseudomonas Aeruginosa Infection

BACKGROUND: Type I interferon (IFN-I) predisposes to bacterial superinfections, an important problem during viral infection or treatment with interferon-alpha (IFN-alpha). IFN-I-induced neutropenia is one reason for the impaired bacterial control; however there is evidence that more frequent bacterial infections during IFN-alpha-treatment occur independently of neutropenia. METHODS: We analyzed in a mouse model, whether Pseudomonas aeruginosa control is influenced by co-infection with the lymphocytic choriomeningitis virus (LCMV). Bacterial titers, numbers of neutrophils and the gene-expression of liver-lysozyme-2 were determined during a 24 hours systemic infection with P. aeruginosa in wild-type and Ifnar(-/-) mice under the influence of LCMV or poly(I:C). RESULTS: Virus-induced IFN-I impaired the control of Pseudomonas aeruginosa. This was associated with neutropenia and loss of lysozyme-2-expression in the liver, which had captured P. aeruginosa. A lower release of IFN-I by poly(I:C)-injection also impaired the bacterial control in the liver and reduced the expression of liver-lysozyme-2. Low concentration of IFN-I after infection with a virulent strain of P. aeruginosa alone impaired the bacterial control and reduced lysozyme-2-expression in the liver as well. CONCLUSION: We found that during systemic infection with P. aeruginosa Kupffer cells quickly controlled the bacteria in cooperation with neutrophils. Upon LCMV-infection this cooperation was disturbed

Basal cell carcinoma risk and solar UV exposure in occupationally relevant anatomic sites: do histological subtype, tumor localization and Fitzpatrick phototype play a role? A population-based case-control study

Background A two-fold risk increase to develop basal cell carcinoma was seen in outdoor workers exposed to high solar UV radiation compared to controls. However, there is an ongoing discussion whether histopathological subtype, tumor localization and Fitzpatrick phototype may influence the risk estimates. Objectives To evaluate the influence of histological subtype, tumor localization and Fitzpatrick phototype on the risk to develop basal cell carcinoma in highly UV-exposed cases and controls compared to those with moderate or low solar UV exposure. Methods Six hundred forty-three participants suffering from incident basal cell carcinoma in commonly sun-exposed anatomic sites (capillitium, face, lip, neck, dorsum of the hands, forearms outside, décolleté) of a population-based, case-control, multicenter study performed from 2013 to 2015 in Germany were matched to controls without skin cancer. Multivariate logistic regression analysis was conducted stratified for histological subtype, phototype 1/2 and 3/4. Dose-response curves adjusted for age, age2, sex, phototype and non-occupational UV exposure were calculated. Results Participants with high versus no (OR 2.08; 95% CI 1.24–3.50; p = 0.006) or versus moderate (OR 2.05; 95% CI 1.15–3.65; p = 0.015) occupational UV exposure showed a more than two-fold significantly increased risk to develop BCC in commonly UV-exposed body sites. Multivariate regression analysis did not show an influence of phototype or histological subtype on risk estimates. The restriction of the analysis to BCC cases in commonly sun-exposed body sites did not influence the risk estimates. The occupational UV dosage leading to a 2-fold increased basal cell carcinoma risk was 6126 standard erythema doses. Conclusion The risk to develop basal cell carcinoma in highly occupationally UV-exposed skin was doubled consistently, independent of histological subtype, tumor localization and Fitzpatrick phototype

Determination of the calibration factor of polysulphone film UV dosemeters for terrestrial solar radiation.

Polysulphone film is used as a personal UV dosemeter in dermatological or epidemiological studies. The relative efficiency of this detector does not exactly match the action spectrum as proposed by the International Commission on Non-Ionizing Radiation Protection (ICNIRP) and to which the UV dose and exposure limits refer. Therefore, the calibration of the dosemeter depends on the spetrum. In the present paper the variation of the calibration factor for terrestrial solar UV spectra is analysed on the basis of a two year observation period at a site near Munich. Germany. A detailed error estimation is included. It is shown that the variation of the calibration factor within this class of spectra is the main contribution to the total uncertainty of the dose determination, which can be up to 40%. The shape of the spectrum of terrestrial solar UV radiation is mainly determined by the total ozone column and the solar elevation angle. It is shown how the calibration depends on these two parameters and how this additional information can help to reduce the measurement error to a residual uncertainty of 17%. Exposure studies of terrestrial solar UV radiation using polysulphone film as a dosemeter would gain in accuracy if total ozone column values at the study's site could be measured or taken from satellite or weather service data. The interpretation of the magnitude of the dose uncertainty depends on the further use of these data

UV-Personendosimetrie. T. B: Mit Verwendung des Polysulfonfilms als UV-Sensor Schlussbericht

SIGLEAvailable from TIB Hannover: F00B1544 / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekBundesministerium fuer Bildung und Forschung (BMBF), Bonn (Germany)DEGerman

UV-Personendosimetrie. T. A: Mit Verwendung des Biofilms als UV-Sensor Abschlussbericht

Available from TIB Hannover: F00B871 / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekSIGLEBundesministerium fuer Bildung und Forschung (BMBF), Bonn (Germany)DEGerman