Demonstration by immunoblotting of heterogeneity in the autoantibody response directed against fat cells in Graves' disease

AbstractGuinea pig fat cell membranes (FCM) have been widely used in preference to thyroid membranes as a source of TSH receptors to investigate TSH receptor antibodies in Graves' disease, because FCM are ostensibly free of other thyroid antigens. However, by FCM immunoblotting we have found: (i) 8 of 10 normal sera bound to determinants at 38 and 190 kDa; (ii) 17 other determinants were recognised by 60% of Graves' or Hashimoto sera and by 20% of normal sera; (iii) three determinants at 65–90 kDa were recognised by 5 of 13 Graves' but by none of the normal or Hashimoto sera; and (iv) none of the determinants recognised appeared to be related to the TSH receptor

The Sanandaj–Sirjan Zone in the Neo-Tethyan suture, western Iran: Zircon U–Pb evidence of late Palaeozoic rifting of northern Gondwana and mid-Jurassic orogenesis

The Zagros Orogen, marking the closure of the Neo-Tethyan Ocean, formed by continental collision beginning in the late Eocene to early Miocene. Collision was preceded by a complicated tectonic history involving Pan-African orogenesis, Late Palaeozoic rifting forming Neo-Tethys, followed by Mesozoic convergence on the ocean\u27s northern margin and ophiolite obduction on its southern margin. The Sanandaj-Sirjan Zone is a metamorphic belt in the Zagros Orogen of Gondwanan provenance. Zircon ages have established Pan-African basement igneous and metamorphic complexes in addition to uncommon late Palaeozoic plutons and abundant Jurassic plutonic rocks. We have determined zircon ages from units in the northwestern Sanandaj-Sirjan Zone (Golpaygan region). A sample of quartzite from the June Complex has detrital zircons with U-Pb ages mainly in 800-1050 Ma with a maximum depositional age of 547 ± 32 Ma (latest Neoproterozoic¿earliest Cambrian). A SHRIMP U-Pb zircon age of 336 ± 9 Ma from gabbro in the June Complex indicates a Carboniferous plutonic event that is also recorded in the far northwestern Sanandaj-Sirjan Zone. Together with the Permian Hasanrobat Granite near Golpaygan, they all are considered related to rifting marking formation of Neo-Tethys. Scarce detrital zircons from an extensive package of metasedimentary rocks (Hamadan Phyllite) have ages consistent with the Triassic to Early Jurassic age previously determined from fossils. These ages confirm that an orogenic episode affected the Sanandaj-Sirjan Zone in the Early to Middle Jurassic (Cimmerian Orogeny). Although the Cimmerian Orogeny in northern Iran reflects late Triassic to Jurassic collision of the Turan platform (southern Eurasia) and the Cimmerian microcontinent, we consider that in the Sanandaj-Sirjan Zone a tectonothermal event coeval with the Cimmerian Orogeny resulted from initiation of subduction and closure of rift basins along the northern margin of Neo-Tethys

The Mesoproterozoic to early Neoproterozoic passive margin Lajeado Group and Apiaí Gabbro, Southeastern Brazil

The Lajeado Group in the Ribeira Belt, southeastern Brazil, corresponds to an open-sea carbonate platform, comprised of seven overlapping siliciclastic and carbonatic formations, intruded in its upper portion by the Apiaí Gabbro. These rocks have a Neoproterozoic tectonometamorphic overprint related to arc magmatism and the Brasiliano collisional orogeny. Geochronological constraints are given by new U-Pb SHRIMP and LA-ICP-MS data for Lajeado Group detrital zircons and for magmatic zircons from the Apiaí Gabbro. The youngest detrital zircons in the Lajeado Group are 1400–1200 Ma, and constrain its maximum age of deposition to be <1200 Ma, whereas the 877 ± 8 Ma age for magmatic zircons in the Apiaí Gabbro give the minimum age. Detritus source areas are mainly Paleoproterozoic (2200–1800 Ma) with some Archean and Mesoproterozoic contribution (1500–1200 Ma), with distal or tectonic stable cratonic character. The Lajeado Group should be a Stenian–Tonian carbonate platform passive margin of a continent at this time, namely the Columbia/Nuna or the Rodinia. The Apiaí Gabbro displays similar age to other intrusive basic rocks in the Lajeado and Itaiacoca groups and represents tholeiitic MORB-like magmatism that we relate to the initial break-up of a Mesoproterozoic continent and the formation of the Brasiliano oceans