308 research outputs found

    Cesarean Scar Defect Manifestations during Pregnancy and Delivery

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    The cesarean scar is a significant risk factor for the following pregnancies and especially deliveries. In this chapter, we discussed the diagnosis, incidence, detection, manifestations, and prognosis of pregnancy and delivery with cesarean scars. A systematic review of current literature showed that a manifestation of cesarean scars during the following pregnancies is not predictable, in general, although modern visualization technologies could reveal some specific features of scar defects that are associated with complications during pregnancy and delivery. However, there is no factor, which could serve as the main prognostic guide for obstetricians to make a decision for VBAC, thus Edwin Cragin’s phrase “once a cesarean, always a cesarean” has represented the essential healthcare issue over the century. At the moment, the most reasonable measurements to prevent uterine scar complications are reducing the rate of Cesarean Sections, opening the uterus transversely in the lower segment, and stitching the uterus with one layer only continuously using a big needle preferable by Stark technique of Cesarean section

    Nitrated nucleosome levels and neuropsychiatric events in systemic lupus erythematosus; a multi-center retrospective case-control study.

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    BACKGROUND: In patients with systemic lupus erythematosus (SLE) there is no serological test that will reliably distinguish neuropsychiatric (NP) events due to active SLE from those due to other causes. Previously we showed that serum levels of nitrated nucleosomes (NN) were elevated in a small number of patients with NPSLE. Here we measured serum NN in samples from a larger population of patients with SLE and NP events to see whether elevated serum NN could be a marker for NPSLE. METHODS: We obtained serum samples from patients in the Systemic Lupus International Collaborative Clinics (SLICC) inception cohort. This included 216 patients with NP events and two matched controls with SLE but no NP events for each of these patients. For the NP patients we tested samples taken before, during and after the NP event. RESULTS: Twenty-six patients had events attributed to SLE according to the most stringent SLICC attribution rule. In these patients there was no association between onset of event and elevated serum NN. In 190 patients in whom events were not attributed to SLE by the SLICC rules, median serum NN was elevated at the onset of event (P = 0.006). The predominant clinical features in this group of 190 patients were headache, mood disorders and anxiety. CONCLUSIONS: Serum NN levels rise at the time of an NP event in a proportion of patients with SLE. Further studies are needed to determine the value of serum NN as a biomarker for NPSLE

    Murine 5T multiple myeloma cells induce angiogenesis in vitro and in vivo

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    Multiple myeloma is a B cell malignancy. Recently, it has been demonstrated that bone marrow samples of patients with multiple myeloma display an enhanced angiogenesis. The mechanisms involved seem to be multiple and complex. We here demonstrate that the murine 5T multiple myeloma models are able to induce angiogenesis in vitro by using a rat aortic ring assay and in vivo by determining the microvessel density. The rat aortic rings cultured in 5T multiple myeloma conditioned medium exhibit a higher number of longer and more branched microvessels than the rings cultured in control medium. In bone marrow samples from 5T multiple myeloma diseased mice, a statistically significant increase of the microvessel density was observed when compared to bone marrow samples from age-matched controls. The angiogenic phenotype of both 5T multiple myeloma cells could be related, at least in part, to their capacity to produce vascular endothelial growth factor. These data clearly demonstrate that the 5T multiple myeloma models are good models to study angiogenesis in multiple myeloma and will allow to unravel the mechanisms of neovascularisation, as well as to test new putative inhibitors of angiogenesis

    Mysid crustaceans as standard models for the screening and testing of endocrine-disrupting chemicals

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    Author Posting. © Springer, 2007. This is the author's version of the work. It is posted here by permission of Springer for personal use, not for redistribution. The definitive version was published in Ecotoxicology 16 (2007): 205-219, doi:10.1007/s10646-006-0122-0.Investigative efforts into the potential endocrine-disrupting effects of chemicals have mainly concentrated on vertebrates, with significantly less attention paid to understanding potential endocrine disruption in the invertebrates. Given that invertebrates account for at least 95% of all known animal species and are critical to ecosystem structure and function, it remains essential to close this gap in knowledge and research. The lack of progress regarding endocrine disruption in invertebrates is still largely due to: (1) our ignorance of mode-of-action, physiological control, and hormone structure and function in invertebrates; (2) lack of a standardized invertebrate assay; (3) the irrelevance to most invertebrates of the proposed activity-based biological indicators for endocrine disruptor exposure (androgen, estrogen and thyroid); (4) limited field studies. Past and ongoing research efforts using the standard invertebrate toxicity test model, the mysid shrimp, have aimed at addressing some of these issues. The present review serves as an update to a previous publication on the use of mysid shrimp for the evaluation of endocrine disruptors (Verslycke et al., 2004a). It summarizes recent investigative efforts that have significantly advanced our understanding of invertebrate-specific endocrine toxicity, population modeling, field studies, and transgeneration standard test development using the mysid model.Supported by a Fellowship of the Belgian American Educational Foundation

    Diapause as escape strategy to exposure to toxicants: response of Brachionus calyciforus to arsenic

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    Invertebrate organisms commonly respond to environmental fluctuation by entering diapause. Production of diapause in monogonont rotifers involves a previous switch from asexual to partial sexual reproduction. Although zooplankton have been used in ecotoxicological assays, often their true vulnerability to toxicants is underestimated by not incorporating the sexual phase. We experimentally analyzed traits involved in sexual reproduction and diapause in the cyclically parthenogenetic freshwater rotifer, Brachionus calyciflorus, exposed to arsenic, a metalloid naturally found in high concentrations in desert zones, focusing on the effectiveness of diapause as an escape response in the face of an adverse condition. Addition of sublethal concentrations of arsenic modified the pattern of diapause observed in the rotifer: investment in diapause with arsenic addition peaked earlier and higher than in non-toxicant conditions, which suggests that sexual investment could be enhanced in highly stressed environmental conditions by increased responsiveness to stimulation. Nevertheless, eggs produced in large amount with arsenic, were mostly low quality, and healthy-looking eggs had lower hatching success, therefore it is unclear whether this pattern is optimum in an environment with arsenic, or if rather arsenic presence in water bodies disturbs the optimal allocation of offspring entering diapause. We observed high accumulation of arsenic in organisms exposed to constant concentration after several generations, which suggests that arsenic may be accumulated transgenerationally. The sexual phase in rotifers may be more sensitive to environmental conditions than the asexual one, therefore diapause attributes should be considered in ecotoxicological assessment because of its ecological and evolutionary implications on lakes biodiversity

    The presence of intermediate-mass black holes in globular clusters and their connection with extreme horizontal branch stars

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    By means of a multimass isotropic and spherical model that includes the self-consistent treatment of a central intermediate-mass black hole (IMBH), the influence of this black hole on the morphological and physical properties of globular clusters is investigated. In agreement with recent numerical studies, it is found that a cluster (with mass M) hosting an IMBH (with mass M_BH) shows, outside the region of gravitational influence of the black hole, a core-like profile resembling a King profile with concentration c < 2, although with a slightly steeper behaviour in the core region. In particular, the core logarithmic slope is s < 0.25 for reasonably low IMBH masses (M_BH < M/100), and c decreases monotonically with M_BH. Completely power-law density profiles (similar to, for example, those of collapsed clusters) are admitted only in the presence of a black hole with an unrealistic M_BH > M. The mass range estimate 12s - 4.8 < log (M_BH/M)< -1.1c - 0.69, depending on the morphological parameters, is deduced by considering a wide range of models. Applying this estimate to a set of 39 globular clusters, it is found that NGC 2808, NGC 6388, M80, M13, M62, M54 and G1 (in M31) probably host an IMBH. For them, the scaling laws M_BH ~ 0.09(M/M_sol)^{0.7} M_sol and M_BH ~ 50[sigma/ (km s^-1)]^{1.2} M_sol are identified from weighted least-squares fits. An important result of this 'collective' study is that a strong correlation exists between the presence of an extreme blue horizontal branch and the presence of an IMBH. In particular, the presence of a central IMBH in M13 and NGC 6388 could explain why these clusters possess extreme horizontal-branch stars, in contrast to their 'second parameter' counterparts M3 and 47 Tuc.Comment: LaTeX, 15 pages, 8 figures, 4 tables included. Final version with new G1 data. Accepted for publication on MNRAS. The definitive version is available at www.blackwell-synergy.co

    Molecular characterization of occult hepatitis B virus infection in patients with end-stage liver disease in Colombia.

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    ABSTARCT: Hepatitis B virus (HBV) occult infection (OBI) is a risk factor to be taken into account in transfusion, hemodialysis and organ transplantation. The aim of this study was to identify and characterize at the molecular level OBI cases in patients with end-stage liver disease. METHODS: Sixty-six liver samples were obtained from patients with diagnosis of end-stage liver disease submitted to liver transplantation in Medellin (North West, Colombia). Samples obtained from patients who were negative for the surface antigen of HBV (n = 50) were tested for viral DNA detection by nested PCR for ORFs S, C, and X and confirmed by Southern-Blot. OBI cases were analyzed by sequencing the viral genome to determine the genotype and mutations; additionally, viral genome integration events were examined by the Alu-PCR technique. RESULTS: In five cases out of 50 patients (10%) the criteria for OBI was confirmed. HBV genotype F (subgenotypes F1 and F3), genotype A and genotype D were characterized in liver samples. Three integration events in chromosomes 5q14.1, 16p13 and 20q12 affecting Receptor-type tyrosine-protein phosphatase T, Ras Protein Specific Guanine Nucleotide Releasing Factor 2, and the zinc finger 263 genes were identified in two OBI cases. Sequence analysis of the viral genome of the 5 OBI cases showed several punctual missense and nonsense mutations affecting ORFs S, P, Core and X. CONCLUSIONS: This is the first characterization of OBI in patients with end-stage liver disease in Colombia. The OBI cases were identified in patients with HCV infection or cryptogenic cirrhosis. The integration events (5q14.1, 16p13 and 20q12) described in this study have not been previously reported. Further studies are required to validate the role of mutations and integration events in OBI pathogenesis

    On the nature of the brightest globular cluster in M81

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    We analyse the photometric, chemical, star formation history and structural properties of the brightest globular cluster (GC) in M81, referred to as GC1 in this work, with the intention of establishing its nature and origin. We find that it is a metal-rich ([Fe/H] = -0.60 +/- 0.10), alpha-enhanced ([alpha/Fe] similar to 0.20 +/- 0.05), core-collapsed (core radius r(c) = 1.2 pc, tidal radius r(t) = 76r(c)), old (&gt; 13 Gyr) cluster. It has an ultraviolet excess equivalent of similar to 2500 blue horizontal branch stars. It is detected in X-rays indicative of the presence of low-mass binaries. With a mass of 1.0 x 10(7) M-circle dot, the cluster is comparable in mass to M31-G1 and is four times more massive than omega Cen. The values of r(c), absolute magnitude and mean surface brightness of GC1 suggest that it could be, like massive GCs in other giant galaxies, the left-over nucleus of a dissolved dwarf galaxy
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