156 research outputs found
A retrospective study on IVF outcome in euthyroid patients with anti-thyroid antibodies: effects of levothyroxine, acetyl-salicylic acid and prednisolone adjuvant treatments
<p>Abstract</p> <p>Background</p> <p>Anti-thyroid antibodies (ATA), even if not associated with thyroid dysfunction, are suspected to cause poorer outcome of in vitro fertilization (IVF).</p> <p>Methods</p> <p>We retrospectively analyzed: (a) the prevalence of ATA in euthyroid infertile women, (b) IVF outcome in euthyroid, ATA+ patients, and (c) the effect of adjuvant treatments (levothyroxine alone or associated with acetylsalicylic acid and prednisolone) on IVF results in ATA+ patients. One hundred twenty-nine euthyroid, ATA+ women undergoing IVF were compared with 200 matched, ATA-controls. During IVF cycle, 38 ATA+ patients did not take any adjuvant treatment, 55 received levothyroxin (LT), and 38 received LT +acetylsalicylic acid (ASA)+prednisolone (P).</p> <p>Results</p> <p>The prevalence of ATA among euthyroid, infertile patients was 10.5%, similar to the one reported in euthyroid women between 18 and 45 years. ATA+ patients who did not receive any adjuvant treatment showed significantly poorer ovarian responsiveness to stimulation and IVF results than controls. ATA+ patients receiving LT responded better to ovarian stimulation, but had IVF results as poor as untreated ATA+ women. Patients receiving LT+ASA+P had significantly higher pregnancy and implantation rates than untreated ATA+ patients (PR/ET 25.6% and IR 17.7% vs. PR/ET 7.5% and IR 4.7%, respectively), and overall IVF results comparable to patients without ATA (PR/ET 32.8% and IR 19%).</p> <p>Conclusion</p> <p>These observations suggest that euthyroid ATA+ patients undergoing IVF could have better outcome if given LT+ASA+P as adjuvant treatment. This hypothesis must be verified in further randomized, prospective studies.</p
An improved model of the Edgeworth-Kuiper debris disk
(Abridged) We access the expected EKB dust disk properties by modeling. We
treat the debiased population of the known transneptunian objects (TNOs) as
parent bodies and generate the dust with our collisional code. The resulting
dust distributions are modified to take into account the influence of
gravitational scattering and resonance trapping by planets on migrating dust
grains as well as the effect of sublimation. A difficulty is that the amount
and distribution of dust are largely determined by sub-kilometer-sized bodies.
These are directly unobservable, and their properties cannot be accessed by
collisional modeling, because objects larger than 10...60m in the present-day
EKB are not in a collisional equilibrium. To place additional constraints, we
use in-situ measurements of the New Horizons spacecraft within 20AU. We show
that the TNO population has to have a break in the size distribution at s<70km.
However, even this still leaves us with several models that all correctly
reproduce a nearly constant dust impact rates in the region of giant planet
orbits and do not violate the constraints from the non-detection of the EKB
dust thermal emission by the COBE spacecraft. The modeled EKB dust disks, which
conform to the observational constraints, can either be transport-dominated or
intermediate between the transport-dominated and collision-dominated regime.
The in-plane optical depth of such disks is tau(r>10AU)~10^-6 and their
fractional luminosity is f_d~10^-7. Planets and sublimation are found to have
little effect on dust impact fluxes and dust thermal emission. The spectral
energy distribution of an EKB analog, as would be seen from 10pc distance,
peaks at wavelengths of 40...50\mum at F~0.5mJy, which is less than 1% of the
photospheric flux at those wavelengths. Therefore, exact EKB analogs cannot be
detected with present-day instruments such as Herschel/PACS.Comment: 10 pages, 8 figures, accepted for publication in Astronomy and
Astophysic
Complex circular subsidence structures in tephra deposited on large blocks of ice: Varða tuff cone, Öræfajökull, Iceland
Several broadly circular structures up to 16 m in diameter, into which higher strata have sagged and locally collapsed, are present in a tephra outcrop on southwest Öræfajökull, southern Iceland. The tephra was sourced in a nearby basaltic tuff cone at Varða. The structures have not previously been described in tuff cones, and they probably formed by the melting out of large buried blocks of ice emplaced during a preceding jökulhlaup that may have been triggered by a subglacial eruption within the Öræfajökull ice cap. They are named ice-melt subsidence structures, and they are analogous to kettle holes that are commonly found in proglacial sandurs and some lahars sourced in ice-clad volcanoes. The internal structure is better exposed in the Varða examples because of an absence of fluvial infilling and reworking, and erosion of the outcrop to reveal the deeper geometry. The ice-melt subsidence structures at Varða are a proxy for buried ice. They are the only known evidence for a subglacial eruption and associated jökulhlaup that created the ice blocks. The recognition of such structures elsewhere will be useful in reconstructing more complete regional volcanic histories as well as for identifying ice-proximal settings during palaeoenvironmental investigations
Helicobacter pylori Type IV Secretion Apparatus Exploits β1 Integrin in a Novel RGD-Independent Manner
Translocation of the Helicobacter pylori (Hp) cytotoxin-associated gene A (CagA) effector protein via the cag-Type IV Secretion System (T4SS) into host cells is a major risk factor for severe gastric diseases, including gastric cancer. However, the mechanism of translocation and the requirements from the host cell for that event are not well understood. The T4SS consists of inner- and outer membrane-spanning Cag protein complexes and a surface-located pilus. Previously an arginine-glycine-aspartate (RGD)-dependent typical integrin/ligand type interaction of CagL with α5β1 integrin was reported to be essential for CagA translocation. Here we report a specific binding of the T4SS-pilus-associated components CagY and the effector protein CagA to the host cell β1 Integrin receptor. Surface plasmon resonance measurements revealed that CagA binding to α5β1 integrin is rather strong (dissociation constant, KD of 0.15 nM), in comparison to the reported RGD-dependent integrin/fibronectin interaction (KD of 15 nM). For CagA translocation the extracellular part of the β1 integrin subunit is necessary, but not its cytoplasmic domain, nor downstream signalling via integrin-linked kinase. A set of β1 integrin-specific monoclonal antibodies directed against various defined β1 integrin epitopes, such as the PSI, the I-like, the EGF or the β-tail domain, were unable to interfere with CagA translocation. However, a specific antibody (9EG7), which stabilises the open active conformation of β1 integrin heterodimers, efficiently blocked CagA translocation. Our data support a novel model in which the cag-T4SS exploits the β1 integrin receptor by an RGD-independent interaction that involves a conformational switch from the open (extended) to the closed (bent) conformation, to initiate effector protein translocation
Exotic state photoproduction
It is shown that the list of unusual mesons planned for a careful study in
photoproduction can be extended by the exotic states with which should be looked for in the decay
channels in the reactions and . The full classification of the states by their
quantum numbers is presented. A simple model for the spin structure of the , , and reaction amplitudes is formulated and the tentative estimates of the
corresponding cross sections at the incident photon energy
GeV are obtained: b, b, b, and b. The problem of the
signal extraction from the natural background due to the other production channels is discussed. In particular the estimates are
presented for the , , and reaction cross sections.
Our main conclusion is that the search for the exotic
states is quite feasible at JEFLAB facility. The expected yield of the events in a 30-day run at the 100% detection
efficiency approximates events.Comment: 19 pages, revtex, 1 figure in postscipt, some comments and references
added, a few minor typos corrected, to be published in Phys. Rev.
DNA glycosylases involved in base excision repair may be associated with cancer risk in BRCA1 and BRCA2 mutation carriers
Integrated asset modeling and development optimization of a sector of oil-gas condensate field X
Seronegative Neuromyelitis Optica Spectrum - The challenges on disease definition and pathogenesis
Identification of Novel Genetic Loci Associated with Thyroid Peroxidase Antibodies and Clinical Thyroid Disease
Peer reviewe
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