No abstract available

[en] Insulitis is considered the histopathological hallmark of type I diabetes. In the non-obese diabetic (NOD) mouse, diabetes has never been observed in the absence of insulitis. The in vivo detection of insulitis could be of relevance for early prediction of diabetes. As approximately 15% of islet-infiltrating lymphocytes express interleukin 2 receptors, the authors have labelled recombinant inter-leukin 2 with ¹²³I and used this radiopharmaceutical to detect insulitis by gamma camera imaging. The authors studied 71 prediabetic NOD and 27 normal Balb/c mice. Labelled α-lactalbumin was used as the control protein. In the first set of experiments the tissue distribution of radiolabelled interleukin 2 in isolated organs from animals sacrificed at different time points was studied. Higher radioactivity was detected in the pancreas of NOD mice injected with labelled interleukin 2, as compared to NOD mice receiving labelled α-lactalbumin. In another set of experiments, gamma camera images have been acquired after injection of ¹²³I-labelled interleukin 2. Radioactivity in the pancreatic region of prediabetic NOD and Balb/c mice showed similar kinetics to those observed by single organ counting, with higher accumulation in the pancreatic region of NOD mice. Finally, a positive correlation was found between the radioactivity in the pancreas and the extent of lymphocytic infiltration. This study demonstrates that ¹²³I-labelled interleukin 2 administered intravenously accumulates specifically in the inflamed pancreas of diabetes-prone NOD mice, suggesting its potential application in human insulin-dependent diabetes mellitus. 34 refs., 6 figs., 1 tab

[en] Lake Massaciuccoli (7 km², 15 km north of Pisa, Tuscany), occupies a shallow depression on a coastal marshy plain.The lake is connected to the sea by a 8 km channel with sluices flowing through an old sandpit pond. Hydrochemistry and stable isotopes are applied to investigate water, salt and nutrient inputs into the lake from drainage channels, groundwater and the sea. In general, the ion concentrations plotted versus Cl^- suggest mixing with seawater, but do not allow to discriminate between contributions of continental water versus seawater - which vary seasonally - nor between those from farming practices and redox processes. Vice-versa, hydrochemistry and isotopic tracers (²H, ¹¹B, ¹³C, ¹⁸O, ³⁴S) combined together, highlight the water mass dynamics and the role of continental waters, show the organic matter cycles and the anthropogenic contributions, and allow to define the main redox processes and their rates. (author)

[en] From 1986, boron isotope data in natural substances increased sharply in scientific publications. Analytical difficulties derived from complex geochemical matrices have been faced and interlaboratory calibrations reported in the boron literature. Boron isotopes are nowdays applied to investigate boron origin and migration in natural waters, sources of boron contamination, water-rock interactions and also contribute to water resource management. This is especially important in those areas where boron content exceeds the local regulations for drinking water supply and boron sources need to be identified. ISOBORDAT, an interactive database on boron isotope composition and content in natural waters is presented to the wider community of boron isotope users. The database's structure, scope and applications are reported, along with a discussion on δ¹¹B values obtained in Italian waters. In the database boron data are structured in the following categories: rainwater, rivers, lakes, groundwater and potential contaminants. New categories (medium and high enthalpy fluids from volcanic and geothermal areas) are anticipated. ISOBORDAT aims to be as interactive as possible and will be developed taking into account information and suggestions received. The database is continually undergoing revision to keep pace with continuous data publication. Indications of data that are missing at present are greatly appreciated. (author)

[en] We have studied the influence of Al substitution on the crystal and magnetic structure of the Laves hydrides Y(Mn_1-xAl_x)₂H_y with maximal hydrogen content (y=4±0.3). A small amount of Al breaks the magnetic long-range order, which was stabilized in the pure compound YMn₂H_4.3 by a peculiar hydrogen superstructure. This strong effect of the Al substitution is not directly related to the dilution of the magnetic Mn lattice, but to the onset of hydrogen disorder in the interstitial sites