U–Pb zircon ages, geochemical and isotopic compositions of granitoids in Songpan-Garze fold belt, eastern Tibetan Plateau: constraints on petrogenesis and tectonic evolution of the basementevolution of the basement

The Songpan-Garze fold belt, located in the eastern part of the Tibetan Plateau, covers a huge triangular area bounded by the Yangtze (South China), the North China and the Tibetan Plateau blocks. In the northeastern part of the Songpan-Garze fold belt, the Yanggon and Maoergai granitoids provide insights into regional tectono-magmatic events, basement nature and tectonic evolution. U–Pb zircon SHRIMP dating shows that the Yanggon and Maoergai granitoids have magmatic crystallization ages of 221 ± 3.8 Ma and 216 ± 5.7 Ma, respectively. Both the granitoids display adakitic geochemical signatures, suggesting that their magma was derived from partial melting of thickened lower crust. Pb–Sr–Nd isotopic compositions for granitoids reveal that there is an unexposed Proterozoic basement in the Songpan-Garze belt, which has an affinity with the Yangtze block. During development of the Paleo-Tethys ocean, the basement of the Songpan-Garze belt would be a peninsula approaching the Paleo-Tethys ocean from the Yangtze block

Stimulation of secretory IgA and secretory component of immunoglobulins in small intestine of rats treated with Saccharomyces boulardii.

Saccharomyces boulardii (S.b.) is largely used in Western European countries for the treatment of acute infectious enteritis and antibiotic-induced gastrointestinal disorders. To study the mechanisms of the protective effect of S.b. against enteral pathogen infection, we assessed the response of the intestinal secretion of secretory IgA (s-IgA) and of the secretory component of immunoglobulins (SC) to oral administration of high doses (0.5 mg/g body weight, three times per day) of S.b. cells in growing rats. S.b. cells (biological activity: 2.8 x 10(9) viable cells/100 mg) were administered daily by gastric intubation to weanling rats from day 14 until day 22 postpartum. Control groups received either 0.9% saline or ovalbumin following the same schedule. Expressed per milligram of cell protein, SC content was significantly increased in crypt cells isolated from the jejunum (48.5% vs saline controls, P less than 0.05) as it was in the duodenal fluid (62.8% vs saline controls, P less than 0.01) of rats treated with S.b. Oral treatment with S.b. had no effect on the secretion of SC by the liver. In the duodenal fluid of rats treated with S.b. cells, the mean concentration of s-IgA was increased by 56.9% (P less than 0.01) over the concentration of s-IgA measured in saline controls.(ABSTRACT TRUNCATED AT 250 WORDS