Untersuchungen zum partiellen Ab- und Umbau von Kollagen aus Lederfasern unter erhoehtem Druck und erhoehter Temperatur und zur Verarbeitbarkeit der Reaktionsprodukte durch Extrusion und Spritzguss

Ziel des Forschungsvorhabens war die Untersuchng des Verhaltens von Kollagen- und Lederfasern bei Temperatur- und Druckeinwirkung. Zur Ermittlung guenstiger Bedingungen fuer den partiellen Abbau des Kollagens wurden Temperatur, Druck, Reaktionszeit und Probenfeuchte in weiten Grenzen variiert. Waehrend trockenes Kollagen bis ca.230 - 240 Grad C unter irreversibler Zerstoerung der Struktur schmilzt, entstehen beim Erhitzen von Kollagen bei Wassergehalten von ca. 10% durch partiellen Abbau gelatine- bzw. leimaehnliche Produkte. Ihr Anteil steigt mit der Temperatur, dem Wassergehalt und der Reaktionszeit. Dieser Abbau kann unter statischen (Pressen) und dynamischen Bedingungen (Kneter) durchgefuehrt werden. Eine thermoplastische Verarbeitung der Produkte erscheint auf Grund der erreichbaren Eigenschaften nicht sinnvollSIGLEAvailable from TU Bergakademie, Freiberg (DE)-FILK gGmbH, under shelf-number:9621 / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekBundesministerium fuer Wirtschaft BMWi, Bonn (Germany); Projekttraeger Arbeitsgemeinschaft industrieller Forschungsvereinigungen Otto von Guericke e.V. AiF, Bonn, Berlin (Germany)DEGerman

Surveillance for Presumed BD-IPMN of the Pancreas: Stability, Size, and Age Identify Targets for Discontinuation.

Background and aimsCurrently, most patients with branch duct intraductal papillary mucinous neoplasms (BD-IPMN) are offered indefinite surveillance, resulting in health care costs with questionable benefits regarding cancer prevention. This study sought to identify patients where the risk of cancer is equivalent to an age-matched population, thereby justifying discontinuation of surveillance.MethodsInternational multicenter study involving presumed BD-IPMN without worrisome features (WF) or high-risk stigmata (HRS) at diagnosis who underwent surveillance. Clusters of individuals at risk for cancer development were defined according to cyst size and stability for at least 5 years, and age-matched controls were used for comparison using standardized incidence ratios (SIRs) for pancreatic cancer.ResultsOf 3844 patients with presumed BD-IPMN, 775 (20.2%) developed WF and 68 (1.8%) HRS after a median surveillance of 53 (IQR 53) months. Some 164 patients (4.3%) underwent surgery. Of the overall cohort, 1617 patients (42%) remained stable without developing WF or HRS for at least 5 years. In patients 75 years or older, the SIR was 1.12 (95%CI 0.23-3.39), and in patients 65 years or older with stable lesions below 15mm in diameter after 5 years, the SIR was 0.95 (95%CI 0.11-3.42). The all-cause mortality for patients who did not develop WF or HRS for at least 5 years was 4.9% (n= 79), while the disease-specific mortality was 0.3% (n=5).ConclusionsThe risk of developing pancreatic malignancy in presumed BD-IPMN without WF or HRS after 5 years of surveillance is comparable to that of the general population depending on cyst size and patient age. Surveillance discontinuation could be justified after 5 years of stability in patients older than 75 years with cysts < 30 mm, and in patients 65 years or older who have cysts ≤ 15 mm

Students' participation in collaborative research should be recognised

Letter to the editor