556 research outputs found

    Hypoxia and hypoxia inducible factor-1Ξ± are required for normal endometrial repair during menstruation

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    About a quarter of pre-menopausal women will suffer from heavy menstrual bleeding in their lives. Here, Maybin and colleagues show hypoxia and subsequent activation of HIF-1Ξ± during menses are required forΒ normal endometrial repair, and identify pharmacological stabilisation of HIF-1Ξ± as a potential therapeutic strategy for this debilitating condition

    Omalizumab may decrease IgE synthesis by targeting membrane IgE+ human B cells

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    Omalizumab, is a humanized anti-IgE monoclonal antibody used to treat allergic asthma. Decreased serum IgE levels, lower eosinophil and B cell counts have been noted as a result of treatment. In vitro studies and animal models support the hypothesis that omalizumab inhibits IgE synthesis by B cells and causes elimination of IgE-expressing cells either by induction of apoptosis or induction of anergy or tolerance. METHODS: We examined the influence of omalizumab on human tonsillar B cell survival and on the genes involved in IgE synthesis. Tonsillar B cells were stimulated with IL-4 plus anti-CD40 antibody to induce class switch recombination to IgE production in the presence or absence of omalizumab. Cell viability was assessed and RNA extracted to examine specific genes involved in IgE synthesis. CONCLUSIONS: We found that omalizumab reduced viable cell numbers but this was not through induction of apoptosis. IL-4R and germline CÏ¡ mRNA levels were decreased as well as the number of membrane IgE+ cells in B cells treated with omalizumab. These data suggest that omalizumab may decrease IgE synthesis by human B cells by specifically targeting membrane IgE-bearing B cells and inducing a state of anergy

    Regulation of mammary gland branching morphogenesis by the extracellular matrix and its remodeling enzymes.

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    A considerable body of research indicates that mammary gland branching morphogenesis is dependent, in part, on the extracellular matrix (ECM), ECM-receptors, such as integrins and other ECM receptors, and ECM-degrading enzymes, including matrix metalloproteinases (MMPs) and their inhibitors, tissue inhibitors of metalloproteinases (TIMPs). There is some evidence that these ECM cues affect one or more of the following processes: cell survival, polarity, proliferation, differentiation, adhesion, and migration. Both three-dimensional culture models and genetic manipulations of the mouse mammary gland have been used to study the signaling pathways that affect these processes. However, the precise mechanisms of ECM-directed mammary morphogenesis are not well understood. Mammary morphogenesis involves epithelial 'invasion' of adipose tissue, a process akin to invasion by breast cancer cells, although the former is a highly regulated developmental process. How these morphogenic pathways are integrated in the normal gland and how they become dysregulated and subverted in the progression of breast cancer also remain largely unanswered questions

    Transcriptional landscape of bone marrow-derived very small embryonic-like stem cells during hypoxia

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    <p>Abstract</p> <p>Background</p> <p>Hypoxia is a ubiquitous feature of many lung diseases and elicits cell-specific responses. While the effects of hypoxia on stem cells have been examined under <it>in vitro </it>conditions, the consequences of <it>in vivo </it>oxygen deprivation have not been studied.</p> <p>Methods</p> <p>We investigated the effects of <it>in vivo </it>hypoxia on a recently characterized population of pluripotent stem cells known as very small embryonic-like stem cells (VSELs) by whole-genome expression profiling and measuring peripheral blood stem cell chemokine levels.</p> <p>Results</p> <p>We found that exposure to hypoxia in mice mobilized VSELs from the bone marrow to peripheral blood, and induced a distinct genome-wide transcriptional signature. Applying a computationally-intensive methodology, we identified a hypoxia-induced gene interaction network that was functionally enriched in a diverse array of programs including organ-specific development, stress response, and wound repair. Topographic analysis of the network highlighted a number of densely connected hubs that may represent key controllers of stem cell response during hypoxia and, therefore, serve as putative targets for altering the pathophysiologic consequences of hypoxic burden.</p> <p>Conclusions</p> <p>A brief exposure to hypoxia recruits pluripotent stem cells to the peripheral circulation and actives diverse transcriptional programs that are orchestrated by a selective number of key genes.</p

    Bi-allelic variants in TSPOAP1, encoding the active zone protein RIMBP1, cause autosomal recessive dystonia

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    Dystonia is a debilitating hyperkinetic movement disorder, which can be transmitted as a monogenic trait. Here, we describe homozygous frameshift, nonsense and missense variants in TSPOAP1, encoding the active zone RIM-binding protein 1 (RIMBP1), as a novel genetic cause of autosomal recessive dystonia in seven subjects from three unrelated families. Subjects carrying loss-of-function variants presented with juvenile-onset progressive generalized dystonia, associated with intellectual disability and cerebellar atrophy. Conversely, subjects carrying a pathogenic missense variant (p.Gly1808Ser) presented with isolated adult-onset focal dystonia. In mice, complete loss of RIMBP1, known to reduce neurotransmission, led to motor abnormalities reminiscent of dystonia, decreased Purkinje cell dendritic arborization, and reduced numbers of cerebellar synapses. In vitro analysis of the p.Gly1808Ser variant showed larger spike-evoked calcium transients and enhanced neurotransmission, suggesting that RIMBP1-linked dystonia can be caused by either reduced or enhanced rates of spike-evoked release in relevant neural networks. Our findings establish a direct link between dysfunction of the presynaptic active zone and dystonia and highlight the critical role played by well-balanced neurotransmission in motor control and disease pathogenesis

    Pre-operative pulmonary assessment for patients with hip fracture

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    Hip fracture is a common injury among the elderly. Although patients who receive hip fracture surgery carry the best functional recovery compared to other treatment modalities, the presence of postoperative pulmonary complications, such as atelectasis, pneumonia, and pulmonary thromboembolism, may contribute to increased length of hospital stay, perioperative morbidity, and mortality. This review aims to provide evidence-based recommendations for preoperative assessment and perioperative strategies to reduce the risk of pulmonary complications after hip fracture surgery. Clinical assessment and basic laboratory results are sufficient to stratify the risk of postoperative pulmonary complications. Well-documented risk factors for pulmonary complications include advanced age, poor general health status, current infections, pre-existing cardiopulmonary diseases, hypoalbuminemia, and impaired renal function. Apart from optimizing the patient's medical conditions, interventions such as lung expansion maneuvers and thromboprophylaxis have been proven to be effective in reducing the risk of pulmonary complications after hip fracture surgery

    Dynamics of Wind Setdown at Suez and the Eastern Nile Delta

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    BACKGROUND: Wind setdown is the drop in water level caused by wind stress acting on the surface of a body of water for an extended period of time. As the wind blows, water recedes from the upwind shore and exposes terrain that was formerly underwater. Previous researchers have suggested wind setdown as a possible hydrodynamic explanation for Moses crossing the Red Sea, as described in Exodus 14. METHODOLOGY/PRINCIPAL FINDINGS: This study analyzes the hydrodynamic mechanism proposed by earlier studies, focusing on the time needed to reach a steady-state solution. In addition, the authors investigate a site in the eastern Nile delta, where the ancient Pelusiac branch of the Nile once flowed into a coastal lagoon then known as the Lake of Tanis. We conduct a satellite and modeling survey to analyze this location, using geological evidence of the ancient bathymetry and a historical description of a strong wind event in 1882. A suite of model experiments are performed to demonstrate a new hydrodynamic mechanism that can cause an angular body of water to divide under wind stress, and to test the behavior of our study location and reconstructed topography. CONCLUSIONS/SIGNIFICANCE: Under a uniform 28 m/s easterly wind forcing in the reconstructed model basin, the ocean model produces an area of exposed mud flats where the river mouth opens into the lake. This land bridge is 3-4 km long and 5 km wide, and it remains open for 4 hours. Model results indicate that navigation in shallow-water harbors can be significantly curtailed by wind setdown when strong winds blow offshore

    Outcome of Patients With Newly Diagnosed Systemic Light-Chain Amyloidosis Associated With Deletion of 17p

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    We analyzed 44 patients with newly diagnosed systemic light-chain amyloidosis (AL) and del 17p, a rare finding in AL. Predictors of overall and progression-free survival were cardiac involvement at diagnosis and hematologic response to therapy, respectively. Median survivals of patients with > 50% and ≀ 50% del 17p plasma cells were 28 and 52 months (P =.08). Introduction: Deletion 17p (del 17p) portends a poor prognosis in myeloma, but its significance in light-chain amyloidosis is unknown. Patients and Methods: We identified patients with light-chain amyloidosis and del 17p at diagnosis, and analyzed presenting characteristics, treatments, and clinical outcomes. All had baseline biopsy results showing amyloid and serologic and marrow studies, including standard fluorescence in-situ hybridization determinations of del 17p using commercial probes. Consensus criteria for hematologic and organ involvement, progression, and response were used. Kaplan-Meier (log rank) analyses and Cox regression analysis of baseline variables were used to identify predictors of overall and progression-free survival (PFS). Six-month landmark analyses were performed to assess the impact of treatment-related variables. Results: We identified 44 patients from 7 countries with median marrow and del 17p plasma cells of 22% (range, 3%-100%) and 30% (2%-93%). Ninety-five percent had cardiac involvement, including 44% stage III. Two-thirds of the patients initially received bortezomib-based therapy. Forty-nine percent of patients experienced complete response or very good partial response, with median time to best response of 4 months (range, 1-28 months). Median overall survival and PFS were 49 and 32 months. Cardiac stage and hematologic response were the key predictors of outcomes. Patients with > 50% and ≀ 50% del 17p in clonal plasma cells had median survivals of 28 and 52 months, respectively (P =.08). In landmark analyses, only hematologic response predicted both overall survival and PFS. Conclusion: Cardiac stage, hematologic response, and del 17p percentage impact outcomes in these cases. Emphasis should be placed on optimizing supportive care and achieving a deep hematologic response
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