327 research outputs found

    Decadal timescale shift in the ^14C record of a central equatorial Pacific coral

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    Coral skeletal radiocarbon records reflect seawater Δ^14C and are useful for reconstructing the history of water mass movement and ventilation in the tropical oceans. Here, we reconstructed the inter-annual variability in central equatorial Pacific surface water Δ^14C from 1922–1956 using near-monthly 14C measurements in a Porites sp. coral skeleton (FI5A) from the windward side of Fanning Island (3°54'32"N, 159°18'88"W). The most pronounced feature in this record is a large, positive shift in the Δ^14C between 1947 and 1956 that coincides with the switch of the Pacific Decadal Oscillation (PDO) from a positive to a negative phase in the mid-1940s. Although the absolute Δ^14C values from 1950–1955 in FI5A differ from the Δ^14C values of another coral core collected from the opposite side of the island, both records show a large, positive shift in their Δ^14C records at that time. The relative increase in the Δ^14C of each record is consistent with the premise that a common mechanism is controlling the Δ^14C records within each coral record. Overall, the Fanning Δ^14C data support the notion that a significant amount of subtropical seawater is arriving at the Equator, but does not allow us to determine the mechanism for its transport

    FRI0499 ACROMEGALY ARTROPATHY: IS THERE SOMETHING MORE BEHIND THE PAIN? A CROSS-SECTIONAL STUDY TO EVALUATE RHEUMATIC DISEASE IN GROWTH HORMONE SECRETING TUMOR PATIENTS

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    Background:Acromegaly is a rare disease with a remarkable impact on patients, both in terms of life expectancy and quality of life. Osteo-articular complications are one of the most frequently reported bothers. The "acromegaly artropathy" characterizes more than 70% of patients at diagnosis. Artropathy affects both spine and peripheral joints. A recent prospective study documented progression of acromegalic arthropathy identified as a worsening of osteophytes and joint space narrowing in 72–74% of patients despite long-term biochemical control. In addiction the Literature has occasionally reported cases of simultaneous presence of rheumatic diseases (rheumatoid arthritis, polymyalgia rheumatica, undifferentiated connective tissue diseases) and acromegaly and in all these cases the treatment has been delayed, because of wrong symptoms attribution to acromegaly artropathy.Objectives:The primary goal of the study is to better characterize joint pain in acromegaly patients and to evaluate the prevalence of rheumatic disease in growth hormone (GH) secreting pituitary tumor patients.Methods:We enrolled 20 acromegaly subjects (AS) and 20 control subjects (CS). In each subject immunological pattern (rheumatoid factor – RF; antinuclear antibodies - ANA, ENA; anti-citrullinated protein antibodies - ACPA; erythrocyte sedimentation rate – ESR) has been evaluated; they, also, underwent bilateral joint ultrasound of hands and wrists and nail capillaroscopy. The Chi square test and the Fisher's exact test were used to evaluate the association between binary variables, while the Spearman's test to evaluate the correlation of continuous ones. A multiple or logistic regression model was calculated in order to define the association between the capillaroscopic alterations and other detected variables.Results:Articular pain emerged as significantly more frequent in AS (p = 0.0269). No statistically significant differences are detected regarding immunological pattern. ANA and ENA screening resulted positive in 10% in AS and in 5% in CS. No IgA ACPA were detected in AS or CS, while IgG ACPA were positive only in one AS subject. No significant differences were detected between IgM and IgG RFin the two groups (AS 5% and CS 0%). Three fold higher IgG FR in AS compared to CS were detected. ESR levels were significantly higher than CS (p = 0.0405), as well as increased power doppler (PWD) articular uptake (AS 30% vs CS 5% p 0.081). The capillaroscopic evaluation showed a significant difference in almost each parameter that has been evaluated (logistic regression: number of enlargement p 0.004, hemorragies p 0.01 and capillaries p 0.001), showing a moderate-severe microangiopathy in AS. Interestingly, analyzing only the acromegaly cohort, we noticed higher GH levels at the enrollment in patients which developed capillary enlargements (GH: 0.95 ng/ml IQ 0,6-1,6) compared to other ones (GH: 0.55 ng/ml IQ 0.4-0.7; p = 0.08) and a significant lower number of hemorrhages (p = 0.02) in patients treated with GH antagonist pegvisomant.Conclusion:Our results demonstrated that joint damage in acromegaly does not seem to have an autoimmune etiology. Therefore, articular damage is mechanical and increased ESR and PWD alterations seems to confirm the presence of an inflammatory component. In addition, acromegaly is characterized by a microvascular pattern of moderate-severe microangiopathy, without correlation to IGF-I, but GH levels. Although requiring further confirmatory studies, our preliminary results seem to indicate how the capillaroscopic examination could be useful to detect earlier microangiopathy and to identify patients with a greater risk of macroangiopathy development..References:[1]Claessen KMJA et al. Bone and joint disorders in acromegaly. Neuroendocrinology. 2016;103(1):86-95.[2]Örük G et al. Is every joint symptom related to acromegaly? Endocrine. 2013 Apr;43(2):404-11.Disclosure of Interests:None declare

    Can heterotrophic uptake of dissolved organic carbon and zooplankton mitigate carbon budget deficits in annually bleached corals?

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    Annual coral bleaching events due to increasing sea surface temperatures are predicted to occur globally by the mid-century and as early as 2025 in the Caribbean, and severely impact coral reefs. We hypothesize that heterotrophic carbon (C) in the form of zooplankton and dissolved organic carbon (DOC) is a significant source of C to bleached corals. Thus, the ability to utilize multiple pools of fixed carbon and/or increase the amount of fixed carbon acquired from one or more pools of fixed carbon (defined here as heterotrophic plasticity) could underlie coral acclimatization and persistence under future ocean-warming scenarios. Here, three species of Caribbean coral—Porites divaricata, P. astreoides, and Orbicella faveolata—were experimentally bleached for 2.5 weeks in two successive years and allowed to recover in the field. Zooplankton feeding was assessed after single and repeat bleaching, while DOC fluxes and the contribution of DOC to the total C budget were determined after single bleaching, 11 months on the reef, and repeat bleaching. Zooplankton was a large C source for P. astreoides, but only following single bleaching. DOC was a source of C for single-bleached corals and accounted for 11–36 % of daily metabolic demand (CHARDOC), but represented a net loss of C in repeat-bleached corals. In repeat-bleached corals, DOC loss exacerbated the negative C budgets in all three species. Thus, the capacity for heterotrophic plasticity in corals is compromised under annual bleaching, and heterotrophic uptake of DOC and zooplankton does not mitigate C budget deficits in annually bleached corals. Overall, these findings suggest that some Caribbean corals may be more susceptible to repeat bleaching than to single bleaching due to a lack of heterotrophic plasticity, and coral persistence under increasing bleaching frequency may ultimately depend on other factors such as energy reserves and symbiont shuffling

    GH therapy in adult GH deficiency: a review of treatment schedules and the evidence for low starting doses.

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    Recombinant human growth hormone (GH) has been licensed for use in adult patients with GH deficiency (GHD) for over 15 years. Early weight- and surface area-based dosing regimens were effective but resulted in supraphysiological levels of insulin-like growth factor-I (IGF-I) and increased incidence of side effects. Current practice has moved towards individualized regimens, starting with low GH doses and gradually titrating the dose according to the level of serum IGF-I to achieve an optimal dose. Here we present the evidence supporting the dosing recommendations of current guidelines and consider factors affecting dose responsiveness and parameters of treatment response. The published data discussed here lend support for the use of low GH dosing regimens in adult GHD. The range of doses defined as 'low dose' in the studies discussed here (~1-4 mg/week) is in accordance with those recommended in current guidelines and encompasses the dose range recommended by product labels

    Pre-treatment effects on coral skeletal delta\u3csup\u3e13\u3c/sup\u3eC and delta\u3csup\u3e18\u3c/sup\u3eO

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    Pre-treatments are often used to remove organic “contaminant” material prior to isotopic analyses of coral skeletal samples. Here we conducted three experiments to test the pre-treatment effect of water, 30% hydrogen peroxide (H2O2), and household bleach [5.25% sodium hypochlorite (NaClO3) and 0.15% sodium hydroxide (NaOH)], on the stable isotopic composition of coral skeletal samples. First, using a mass balance approach we calculated the expected change in skeletal delta13C due to the removal of all organic carbon. The model showed that (1) the removal of organic carbon (which has a low delta13C value relative to skeletal delta13C) from the skeletal sample should theoretically result in a higher delta13C value of the remaining organic-carbon-free carbonate, and that (2) only at the highest concentrations of skeletal organic carbon within the tissue layer of corals is the contribution of the organic carbon to the overall delta13C skeletal value potentially large enough to be detectable by mass spectrometry. We then conducted two sets of experiments to test the model where we pre-treated a large number of skeletal samples from five species of corals with water, H2O2, bleach, or no pre-treatment for 24 h. Skeletal delta13C generally decreased significantly with water, bleach, and H2O2 pre-treatments which is contrary to the model-predicted increase in delta13C following such pre-treatments. Thus, organic carbon within the skeleton is not a net source of contamination to delta13C analyses. Skeletal delta18O decreased the most with water and bleach pre-treatments. In addition, the effect of H2O2 or bleach pre-treatments on either delta13C or delta18O was not consistent among species or locations. The direction of change in delta13C and delta18O with pre-treatments was no different for skeletal samples taken within or below the tissue layer. Based on our results, we suggest that pre-treatment is not necessary and recommend that pre-treatment not be performed on coral skeletal samples prior to stable isotope analysis to avoid any pre-treatment-induced variability that could significantly compromise inter-colony and inter-species comparisons

    Investigating Coral Bleaching in a Changing Climate: Our State of Understanding and Opportunities to Push the Field Forward

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    [First Paragraph] Coral reefs throughout the world are facing the consequences of large-scale changes in Earth’s climate. In particular, ocean warming is leading to frequent coral bleaching, which is threatening the long-term stability of coral reefs. Coral bleaching is a stress response that results in the disassociation of the mutualistic symbioses (i.e., dysbiosis) between corals and their endosymbiotic algae (Symbiodinium spp.). In the past two decades, there have been four substantial bleaching events, which have affected large geographic areas across the globe, including the worst recorded bleaching event on the Great Barrier Reef in 2016 (Berkelmans et al. 2004; Eakin et al. 2010; Stella et al. 2016). These large-scale bleaching events, in combination with many local-scale stressors, have contributed substantially to global declines in coral populations. In addition, bleaching may lead to compromised coral immunity, possibly resulting in additional mortality by a range of post-bleaching diseases (Maynard et al. 2015, Randall et al. 2014). Given their link to patterns of global-climate change and projections of increased warming in the coming decades, mass coral bleaching events are a key concern. In addition, current climate projections estimate that global bleaching is expected to occur annually by late this century, with more than 90% of reefs facing long-term degradation (Frieler et al. 2012). Furthermore, in locations such as the Caribbean, frequent thermal anomalies and consecutive annual bleaching events are expected to be common in less than 25 years (van Hooidonk et al. 2015). In fact, large-scale bleaching two years in a row was documented for the first time in 2014-2015 in Hawaii and in the Florida Keys. However, not all corals (and other symbiotic cnidarians) are equally susceptible to thermal stress, and some corals have been shown to recover from bleaching more quickly than others. Likewise, not all reefs are equally susceptible, and depending on local conditions, susceptibility can vary from one event to the next. Such variability in resilience could be a cornerstone to reef persistence over the coming century. However, the research needed to test this hypothesis remains to be performed

    Increased prevalence of impulse control disorder symptoms in endocrine diseases treated with dopamine agonists: a cross-sectional study

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    INTRODUCTION: Impulse control disorders (ICDs) have been described as a side effect of dopamine agonists (DAs) in neurological as well as endocrine conditions. Few studies have evaluated the neuropsychological effect of DAs in hyperprolactinemic patients, and these have reported a relationship between DAs and ICDs. Our objective was to screen for ICD symptoms in individuals with DA-treated endocrine conditions. MATERIALS AND METHODS: A cross-sectional analysis was conducted on 132 patients with pituitary disorders treated with DAs (DA exposed), as well as 58 patients with pituitary disorders and no history of DA exposure (non-DA exposed). Participants responded to the full version of the Questionnaire for Impulsive-Compulsive Disorders in Parkinson’s disease (QUIP). RESULTS: Compared with the non-DA-exposed group, a higher prevalence of DA-exposed patients tested positive for symptoms of any ICD or related behavior (52% vs. 31%, p < 0.01), any ICD (46% vs. 24%, p < 0.01), any related behavior (31% vs. 17%, p < 0.05), compulsive sexual behavior (27% vs. 14%, p < 0.04), and punding (20% vs. 7%, p < 0.02) by QUIP. On univariate analysis, DA treatment was associated with a two- to threefold increased risk of any ICD or related behavior [odds ratio (OR) 2.43] and any ICD (OR 2.70). In a multivariate analysis, independent risk factors for any ICD or related behavior were DA use (adjusted OR 2.22) and age (adjusted OR 6.76). Male gender was predictive of the risk of hypersexuality (adjusted OR 3.82). DISCUSSION: Despite the QUIP limitations, a clear sign of increased risk of ICDs emerges in individuals with DA-treated pituitary disorders. Our data contribute to the growing evidence of DA-induced ICDs in endocrine conditions
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