3 research outputs found
Pulmonary Embolism and Intracardiac Type A Thrombus with an Unexpected Outcome
Detection of right heart thrombi (RHT) in the context of pulmonary thromboembolism (PE) is uncommon (4–18%) and increases the risk of mortality beyond the presence of PE alone. Type A thrombi are serpiginous and highly mobile and are thought to be originated from large veins and captured in-transit within the right heart. Optimal management of RHT is still uncertain. A 79-year-old woman, with a history of recent total hysterectomy with adnexectomy and a Wells procedure, presented to the emergency department following an episode of syncope. Computed tomography revealed bilateral PE and the presence of a right atrial thrombus. Transthoracic echocardiography demonstrated a free-floating type A thrombus in the right atrium, protruding into the right ventricle, and signs of pulmonary hypertension and right ventricle dysfunction. Considering the recent surgery and clinical stability, treatment with heparin alone was decided. Subsequent clinical improvement was observed and echocardiographic follow-up revealed complete thrombus dissolution and complete recovery of right ventricle function. Most authors recommend treatment of PE with RHT with thrombolysis or embolectomy followed by anticoagulation, although evidence is scarce. Individual risk of hemorrhage and operatory-related mortality should be taken into account when defining the treatment strategy especially when benefit is not firmly established
Unveiling the neurotoxicity of methylmercury in fish (Diplodus sargus) through a regional morphometric analysis of brain and swimming behavior assessment
The current study aims to shed light on the neurotoxicity of MeHg in fish (white seabream - Diplodus sargus) by the combined assessment of: (i) MeHg toxicokinetics in the brain, (ii) brain morphometry (volume and number of neurons plus glial cells in specific brain regions) and (iii) fish swimming behavior (endpoints associated with the motor performance and the fear/anxiety-like status). Fish were surveyed for all the components after 7 (E7) and 14 (E14) days of dietary exposure to MeHg (8.7 mu gg(-1)), as well as after a post-exposure period of 28 days (PE28). MeHg was accumulated in the brain of D. sargus after a short time (E7) and reached a maximum at the end of the exposure period (E14), suggesting an efficient transport of this toxicant into fish brain. Divalent inorganic Hg was also detected in fish brain along the experiment (indicating demethylation reactions), although levels were 100-200 times lower than MeHg, which pinpoints the organic counterpart as the great liable for the recorded effects. In this regard, a decreased number of cells in medial pallium and optic tectum, as well as an increased hypothalamic volume, occurred at E7. Such morphometric alterations were followed by an impairment of fish motor condition as evidenced by a decrease in the total swimming time, while the fear/anxiety-like status was not altered. Moreover, at E14 fish swam a greater distance, although no morphometric alterations were found in any of the brain areas, probably due to compensatory mechanisms. Additionally, although MeHg decreased almost two-fold in the brain during post-exposure, the levels were still high and led to a loss of cells in the optic tectum at PE28. This is an interesting result that highlights the optic tectum as particularly vulnerable to MeHg exposure in fish. Despite the morphometric alterations reported in the optic tectum at PE28, no significant changes were found in fish behavior. Globally, the effects of MeHg followed a multiphasic profile, where homeostatic mechanisms prevented circumstantially morphometric alterations in the brain and behavioral shifts. Although it has become clear the complexity of matching brain morphometric changes and behavioral shifts, motor-related alterations induced by MeHg seem to depend on a combination of disruptions in different brain regions.Patricia Pereira (SFRH/BPD/69563/2010) benefits from Postdoctoral grant supported by "Fundacao para a Ciencia e a Tecnologia" (FCT). This work has been supported by the Research project financed by FCT PTDC/AAG-REC/2488/2012 (NEUTOXMER - Neurotoxicity of mercury in fish and association with morphofunctional brain alterations and behavior shifts), as well as by the Centre for Environmental and Marine Studies (CESAM). Authors are also grateful to Joana Raimundo, Fatima Brandao, Olinda Araujo and Olivia Cardoso for the support in the laboratory work
Metals(loids) targeting fish eyes and brain in a contaminated estuary - Uncovering neurosensory (un)susceptibility through bioaccumulation, antioxidant and morphometric profiles
This study examined the susceptibility of fish (Liza aurata) eyes and brain to metals(loids) contamination under realistic exposure conditions. A multidimensional approach was applied to fish caught at a chronically contaminated site (BAR) and at a reference site of the Tagus estuary (Portugal), which comprised metals(loids) accumulation in eyes and brain together with a battery of enzymatic and non-enzymatic antioxidants, as well as brain morphometry (i.e. cell density). Trace element levels in the blood, gills, liver and kidney allowed interpretations on their preferential pathway(s) to the eyes and brain. Metals(loids) accumulation pointed out the elevated vulnerability of the fish eyes at BAR, probably related with the direct waterborne uptake. Pb uptake in L. aurata eyes could be associated both with water and indirect pathways. At the most contaminated site, metals(loids) were on the basis of pro-oxidant conditions in the ocular tissues, while no indication of toxicity was recorded in the brain. Overall, the results disclosed a differential bioaccumulation among fish organs, suggesting that, in the L. aurata population studied, metal organotropism underlie the lower susceptibility of the brain comparing to the eyes. However, mechanisms remain little understood and further work is needed.CESAM (UID/AMB/50017 - POCI-01-0145-FEDER-007638), to FCT/MCTES through national funds (PIDDAC), and the co-funding by the FEDER, within the PT2020 Partnership Agreement and Compete 2020, and due for the Research Project NEUTOXMER project (FCT-PTDC/AAGREC/2488/2012) (which provided a research grant to Sónia Puga)info:eu-repo/semantics/publishedVersio