Congenital goiter with hypothyroidism caused by a 5′ splice site mutation in the thyroglobulin gene

In this work we have extended our initial molecular studies of a consanguineous family with two affected goitrous siblings (H.S.N. and Ac.S.N.) with defective thyroglobulin (Tg) synthesis and secretion because of a homozygotic deletion of a fragment of 138 nucleotides (nt) in the central region of the Tg mRNA, identified previously in H.S.N. In order to identify the intron/exon boundaries and to analyze the regions responsible for pre-mRNA processing corresponding to a 138 nt deletion, we performed a screening of a human genomic library. The intron/exon junction sequences were determined from one positive clone by sequencing both strands of the DNA template. The results showed that the deletion mapped between positions 5549 and 5686 of the Tg mRNA and corresponded to exon 30. The positions of the exon limits differed by three nucleotides from the previously reported data obtained from direct sequencing of the deleted reverse transcriptase-polymerase chain reaction fragment from H.S.N. These variations are because the intron/exon junctions in this region were not available at the time when the deletion was first described. The deletion does not affect the reading frame of the resulting mRNA and is potentially fully translatable into a Tg polypeptide chain that is shortened by 46 residues. The same 138 nt deletion was observed in reverse transcriptase-polymerase chain reaction studies performed in the thyroid tissues from Ac.S.N. Genomic DNA analysis showed that a G to T transversion was observed at position +1 in the donor site of intron 30. Both affected patients (H.S.N. and Ac.S.N.) are homozygous for the mutation whereas the normal sister (At.S.N.) had a normal allele pattern. The functional consequences of the deletion are related to structural changes in the protein molecule that either could modify the normal routing of the translation product through the membrane system of the cell or could impair the coupling reaction. Probably the mutant Tg polypeptide might be functionally active in the production of thyroid hormone, because in the presence of a normal iodine ingestion (∼150 μg/day), Ac.S.N. was able to maintain normal serum levels of total triiodothyronine (T3) associated with relatively low serum total thyroxine (T4) with normal somatic development without signs of brain damage.Fil: Targovnik, Hector Manuel. Universidad de Buenos Aires. Facultad de Medicina. Hospital de Clínicas General San Martín; Argentina. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Departamento de Microbiología, Inmunología y Biotecnología. Cátedra de Genética y Biología Molecular; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Inmunología, Genética y Metabolismo. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Inmunología, Genética y Metabolismo; ArgentinaFil: Rivolta, Carina Marcela. Universidad de Buenos Aires. Facultad de Medicina. Hospital de Clínicas General San Martín; Argentina. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Departamento de Microbiología, Inmunología y Biotecnología. Cátedra de Genética y Biología Molecular; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Inmunología, Genética y Metabolismo. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Inmunología, Genética y Metabolismo; ArgentinaFil: Mendive, Fernando M.. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Departamento de Microbiología, Inmunología y Biotecnología. Cátedra de Genética y Biología Molecular; Argentina. Universidad de Buenos Aires. Facultad de Medicina. Hospital de Clínicas General San Martín; ArgentinaFil: Moya, Christian M.. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Departamento de Microbiología, Inmunología y Biotecnología. Cátedra de Genética y Biología Molecular; Argentina. Universidad de Buenos Aires. Facultad de Medicina. Hospital de Clínicas General San Martín; ArgentinaFil: Vono, Jussara. Universidade de Sao Paulo; BrasilFil: Medeiros Neto, Geraldo. Universidade de Sao Paulo; Brasi

Recent advances in the development of magnetically recoverable metal nanoparticle catalysts

The aim of this Account is to provide an overview of our current research activities on the design and modification of superparamagnetic nanomaterials for application in the field of magnetic separation and catalysis. First, an introduction of magnetism and magnetic separation is done. Then, the synthetic strategies that have been developed for generating superparamagnetic nanoparticles spherically coated by silica and other oxides, with a focus on well characterized systems prepared by methods that generate samples of high quality and easy to scale-up, are discussed. A set of magnetically recoverable catalysts prepared in our research group by the unique combination of superparamagnetic supports and metal nanoparticles is highlighted. This Account is concluded with personal remarks and perspectives on this research field

Disinfection of ocular cells and tissues by atmospheric-pressure cold plasma

Low temperature plasmas have been proposed in medicine as agents for tissue disinfection and have received increasing attention due to the frequency of bacterial resistance to antibiotics. Our previous studies (1) demonstrated that atmospheric-pressure cold plasma (APCP) generated by a new portable device that ionizes a flow of helium gas inactivated ocular pathogens in vitro. This study explored whether APCP inactivates ocular pathogens without causing significant tissue damage. We tested the APCP effects on cultured Pseudomonas aeruginosa, Staphylococcus aureus, A. fumigatus, ocular cells (conjunctival fibroblasts and keratocytes) and ex-vivo cornea. Exposure to APCP for 0.5–5 min significantly reduced microbial viability (colony-forming units) but not human cell viability (MTT assay and Tunel analysis). Since our previous study indicated that exposure to plasma increases intracellular reactive oxygen species (ROS) production, ROS levels in APCP exposed microorganisms and keratocytes were analyzed by 2’,7’-dichlorofluorescein diacetate (HDCF-DA) fluorescence. The potential genotoxic effects of plasma on cells and tissues were evaluated by analyses of thymine dimers (TD), genes and proteins involved in DNA damage and repair (OGG1, GPX, NRF2) at set time intervals. High levels of intracellular reactive oxygen species (ROS) were found in exposed microorganisms and cells. Immunoassay confirmed no induction of thymine dimers in corneal tissues. Conversely, a transient expression of genes and proteins recruited following oxidative stress was determined in ocular cells and corneas by qRT-PCR and Western blotting. In conclusion, a short application of APCP appears to be an efficient and rapid ocular disinfectant with ROS production likely causing pathogen killing and no substantial effects on ocular cells and tissues. The same APCP treatment to conjuntival fibroblasts and keratocytes caused a time-restricted formation of ROS and a change in some stress-response genes

Polymer versus phosphine stabilized Rh nanoparticles as components of supported catalysts : implication in the hydrogenation of cyclohexene model molecule

The solution synthesis of rhodium nanoparticles (Rh NPs) was achieved from the organometallic complex [Rh(η³-C₃H₅)₃] under mild reaction conditions in the presence of a polymer (PVP), a monophosphine (PPh₃) and a diphosphine (dppb) as a stabilizer, leading to very small Rh NPs of 2.2, 1.3 and 1.7 nm mean size, with PVP, PPh3 and dppb, respectively. The surface properties of these nanoparticles were compared using a model catalysis reaction namely, hydrogenation of cyclohexene, first under colloidal conditions and then under supported conditions after their immobilization onto an amino functionalized silica-coated magnetite support. PVP-stabilized Rh NPs were the most active catalyst whatever the catalytic conditions as a result of a strong coordination of the phosphine ligands at the metal surface that blocks some surface atoms even after several recycles of the supported nanocatalysts and limit the reactivity of the metallic surface

Latin Americans and Caribbeans in Europe. A cross-country analysis

With the beginning of the 21st century, there has been an acceleration of migratory flows from Latin America and the Caribbean (LAC) to Europe. As a result, and despite the negative impact of the economic crisis, 4.6 million Latin American and Caribbean immigrants reside in Europe, half of them in Spain. This article analyses the recent evolution of these migratory flows, their territorial distribution, and their demographic profiles according to the 2011 European census data disseminated by a new tool -the Census Hub- implemented by the European Statistical System. The analysis shows the existence of a high LAC immigrant concentration in Spain and in certain European cities, a marked young and feminized demographic profile, a great variety of educational levels and a different insertion in each European labour market, although many LAC immigrants work in low-skill occupations, being overqualified and underemployed in most of the countries

Investigation of the effects of atmospheric pressure cold plasma on human cells and tissues

Atmospheric pressure cold plasma (APCP) is a novel tool in medicine for tissue disinfection. We recently reported that 2 minutes of APCP generated by a new portable device that ionizes a flow of helium gas exerted an antimicrobial effect, mainly due to the action of reactive oxygen species (ROS) (P. Brun et al., 2012). Since ROS induced DNA lesions that could lead to point mutations, before using plasma in medical treatment it is important to ascertain the safe usage of this device. In the study presented, we analysed the presence of ROS levels, pre-mutagenic 8-oxodeoxyguanosine (8-OHdG) and the expression of OGG1, a DNA glycosylase specific for the removal of 8-OHdG lesions in cell (fibroblasts and keratocytes) cultures. ROS levels in APCP-exposed microorganisms and keratocytes were detected by 2’,7’-dichlorofluorescein diacetate (HDCF-DA) fluorescence; the potential genotoxic effects of plasma were evaluated by analyses of cell cycle distribution, externalization of phosphatidylserine, HPLC determination of 8-OHdG expression, qRT-PCR and Western blotting of OGG1 gene and protein, at set time intervals. Our results demonstrated that APCP induced ROS formation in exposed human cells, a transient 8-OHdG expression and a consequent adaptative OGG1 response at the transcriptional and translational level. In conclusion, the short application of APCP to cells and tissues has a disinfection effect and leads to time-restricted ROS generation and to oxidative-stress related responses

Supernormal functional reserve of apical segments in elite soccer players: an ultrasound speckle tracking handgrip stress study

<p>Abstract</p> <p>Background</p> <p>Ultrasound speckle tracking from grey scale images allows the assessment of regional strain derived from 2D regardless of angle intonation, and it is highly reproducible. The study aimed to evaluate regional left ventricular functional reserve in elite soccer players.</p> <p>Methods</p> <p>50 subjects (25 elite athletes and 25 sedentary controls), aged 26 ± 3.5, were submitted to an echo exam, at rest and after the Hand Grip (HG) test. Both standard echo parameters and strain were evaluated.</p> <p>Results</p> <p>Ejection fraction was similar in athletes and controls both at rest (athletes 58 ± 2 vs controls 57 ± 4 p ns) and after HG (athletes 60 ± 2 vs controls 58 ± 3 p ns). Basal (septal and anterior) segments showed similar strain values in athletes and controls both at rest (athletes S% -19.9 ± 4.2; controls S% -18.8 ± 4.9 p = ns) and after HG (athletes S% -20.99 ± 2.8; controls S% -19.46 ± 4.4 p = ns). Medium-apical segments showed similar strain values at rest (athletes S% -17.31 ± 2.3; controls S% -20.00 ± 5.3 p = ns), but higher values in athletes after HG (athletes S% -24.47 ± 2.8; controls S% -20.47 ± 5.4 p < 0.05)</p> <p>Conclusion</p> <p>In athletes with physiological myocardial hypertrophy, a brief isometric effort produces enhancement of the strain in medium-apical left ventricular segments, suggesting the presence of a higher regional function reserve which can be elicited with an inotropic challenge and suitable methods of radial function quantification such as 2D-derived strain.</p