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Nicola J.P.,Yale University | Nicola J.P.,National University of Crdoba | Reyna-Neyra A.,Yale University | Saenger P.,Winthrop University | And 7 more authors.
Journal of Clinical Endocrinology and Metabolism | Year: 2015

Context: Iodide (I-), an essential constituent of the thyroid hormones, is actively accumulated in the thyroid by the Na+/I- symporter (NIS), a key plasma membrane protein encoded by the slc5a5 gene. Mutations in slc5a5 cause I- transport defects (ITDs), autosomal-recessive disorders in which I- accumulation is totally or partially impaired, leading to congenital hypothyroidism. The characterization of NIS mutants has yielded significant insights into the molecular mechanism of NIS. Objective: This study aimed to determine the basis of a patient's ITD clinical phenotype, by sequencing her slc5a5 gene. Design: Genomic DNA was purified and the slc5a5 gene sequence determined. Functional in vitro studies were performed to characterize the V270E NIS mutant. Patient: The index patient was diagnosed with hypothyroidism with minimal radioiodide uptake in a normally located, although enlarged, thyroid gland. Results: We identified a new NIS mutation: V270E. The patient had the compound heterozygous NIS mutation R124H/V270E. R124H NIS has been characterized previously. We show that V270E markedly reduces I- uptake via a pronounced (but not total) impairment of the protein's plasma membrane targeting. Remarkably, V270E is intrinsically active. Therefore, a negative charge at position 270 interferes with NIS cell surface trafficking. The patient's minimal I- uptake enabled sufficient thyroid hormone biosynthesis to prevent cognitive impairment. Conclusions: A nonpolar residue at position 270, which all members of the SLC5A family have, is required for NIS plasma membrane targeting. Copyright © 2015 by the Endocrine Society.

Dos Santos-Mallet J.R.,Oswaldo Cruz Foundation | Muller G.A.,Federal University of Santa Catarina | Muller G.A.,Federal University of Paran | Gleiser R.M.,National University of Crdoba | And 4 more authors.
Journal of the American Mosquito Control Association | Year: 2010

The eggs of Aedes scapularis analyzed by scanning electron microscopy are black and elliptical in outline, measuring approximately 620.4 ± 16.74 μm long and 163.7 ± 16.90 m (n 10) wide, with an egg index (length/width ratio) of 3.79. The anterior extremity tapered abruptly from a width of 51.6 μm, while such tapering was more gradual at the posterior extremity, from a width of 61.4 m. The ventral surface of the chorionic coating presented cells with a tubular aspect containing tubercles in rows at a density of 5 to 9 per cell with 2 different sizes, the largest measuring 7.23 ± 0.98 m in a longitudinal diameter and the smallest 4.15 ± 0.53 μm (n 30). In the dorsal region, the external chorionic reticulum had a porous appearance, and its thickness ranged from 2.5 to 4.1 μm. Isolated tubercles presented wide variation per cell. In the central region of some chorionic cells were tubercles of greater diameter, characterized as central tubercles of 8.45 ± 0.67 μm, and around them 3 to 5 smaller tubercles measuring 2.57 ± 0.26 μm. The micropylar apparatus presented a collar with a very evident molding and edges with defined margins for the transition area and a thickness of around 11.1 μm. The micropyle disc margins were raised, measuring around 17.8 μm in diameter and 229 m in circumference. The micropyle orifice was very evident, with a diameter of 1.41 μm. © 2010 by The American Mosquito Control Association, Inc.

Ochoa J.A.,Scorpion Systematics Research Group | Ochoa J.A.,University of Sao Paulo | Ojanguren Affilastro A.A.,Museo Argentino de Ciencias Naturales Bernardino Rivadavia | Mattoni C.I.,National University of Crdoba | Prendini L.,Scorpion Systematics Research Group
Bulletin of the American Museum of Natural History | Year: 2011

The systematics of the Andean scorpion genus, Orobothriurus Maury, 1976 (Bothriuridae Simon, 1880), is revised. New locality records, obtained during recent field expeditions, distribution maps, and a key to identification of the 15 known species, are provided. Six new species are described: Orobothriurus calchaqui, n. sp., from northwestern Argentina; Orobothriurus compagnuccii, n. sp., from the central Andes of Argentina; Orobothriurus huascaran, n. sp., from central Peru; Orobothriurus quewerukana, n. sp., from southern Peru and northern Chile; Orobothriurus ramirezi, n. sp., from central Chile; and Orobothriurus tamarugal, n. sp., from northern Chile. The known distribution of Orobothriurus and the altitude record for scorpions are discussed. The world's altitude record for a scorpion, previously reported as 5550 m, is demonstrated to be 4910 m. © 2011 American Museum of Natural History.

Gordillo S.,CONICET | Gordillo S.,National University of Crdoba | Martinelli J.,University of Chile | Cardenas J.,University of Chile | Sol Bayer M.,University of Chile
Journal of the Marine Biological Association of the United Kingdom | Year: 2011

This paper evaluates if the bivalve Tawera gayi from southern South America represents an opportunity to test ecological variability and environmental changes during the last 6000 years in southern South America. For this purpose, we analyse both modern and fossil (mid-to-late Holocene) T. gayi shells from Tierra del Fuego using different techniques, including taphonomy, stable isotopes, cathodoluminiscence (CL) and linear morphometrics. Taphonomic analysis shows that differences between modern and fossil shells appear best related to local variations of physical factors such as current speed, wave action and freshwater input along the non-uniform Beagle Channel coast. However, slight changes of hydraulic energy regimes throughout the Holocene cannot be ruled out. The analysis of stable isotopes on T. gayi shells indicates a mixing of oceanic waters with freshwater from precipitation, river runoff and glacier meltwater during the mid-to-late Holocene. The high depletion of 18O at ~4400 years before present would be associated with a period of warmer temperatures, the so-called Hypsithermal. Under CL modern and fossil T. gayi shells show a well defined pattern related to the growth dynamics of the shell, which can lead to a better understanding of its biology, adding details to further palaeoenvironmental analysis. Finally, conventional metrics shows that fossil T. gayi shells are smaller and shorter than modern shells. These differences could be related to Holocene environmental changes, but here are best explained on the basis of a predator-prey relationship. This study shows that T. gayi may be a good candidate for looking at evidences of environmental changes in southern South America, and multi-proxy data are necessary to better understand the driving mechanisms of ecological variability and changes over short geological time intervals of few thousands of years. © 2011 Marine Biological Association of the United Kingdom.

Pighn S.A.,National University of Crdoba | Billoni O.V.,National University of Crdoba | Stariolo D.A.,Federal University of Rio Grande do Sul | Cannas S.A.,National University of Crdoba
Journal of Magnetism and Magnetic Materials | Year: 2010

We present the complete zero temperature phase diagram of a model for ultrathin films with perpendicular anisotropy. The whole parameter space of relevant coupling constants is studied in first order anisotropy approximation. Because the ground state is known to be formed by perpendicular stripes separated by Bloch walls, a standard variational approach is used, complemented with specially designed Monte Carlo simulations. We can distinguish four regimes according to the different nature of striped domains: a high anisotropy Ising regime with sharp domain walls, a saturated stripe regime with thicker walls inside which an in-plane component of the magnetization develops, a narrow canted-like regime, characterized by a sinusoidal variation of both the in-plane and the out of plane magnetization components, which upon further decrease of the anisotropy leads to an in-plane ferromagnetic state via a spin reorientation transition (SRT). The nature of domains and walls are described in some detail together with the variation of domain width with anisotropy, for any value of exchange and dipolar interactions. Our results, although strictly valid at T=0, can be valuable for interpreting data on the evolution of domain width at finite temperature, a still largely open problem. © 2010 Elsevier B.V. All rights reserved.

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