Seawater exposure causes hydraulic damage in dying Sitka-spruce trees.

Sea-level rise is one of the most critical challenges facing coastal ecosystems under climate change. Observations of elevated tree mortality in global coastal forests are increasing, but important knowledge gaps persist concerning the mechanism of salinity stress-induced nonhalophytic tree mortality. We monitored progressive mortality and associated gas exchange and hydraulic shifts in Sitka-spruce (Picea sitchensis) trees located within a salinity gradient under an ecosystem-scale change of seawater exposure in Washington State, USA. Percentage of live foliated crown (PLFC) decreased and tree mortality increased with increasing soil salinity during the study period. A strong reduction in gas exchange and xylem hydraulic conductivity (Ks) occurred during tree death, with an increase in the percentage loss of conductivity (PLC) and turgor loss point (πtlp). Hydraulic and osmotic shifts reflected that hydraulic function declined from seawater exposure, and dying trees were unable to support osmotic adjustment. Constrained gas exchange was strongly related to hydraulic damage at both stem and leaf levels. Significant correlations between foliar sodium (Na+) concentration and gas exchange and key hydraulic parameters (Ks, PLC, and πtlp) suggest that cellular injury related to the toxic effects of ion accumulation impacted the physiology of these dying trees. This study provides evidence of toxic effects on the cellular function that manifests in all aspects of plant functioning, leading to unfavourable osmotic and hydraulic conditions.

Declining carbohydrate content of Sitka-spruce treesdying from seawater exposure.

Increasing sea levels associated with climate change threaten the survival of coastal forests, yet the mechanisms by which seawater exposure causes tree death remain poorly understood. Despite the potentially crucial role of nonstructural carbohydrate (NSC) reserves in tree survival, their dynamics in the process of death under seawater exposure are unknown. Here we monitored progressive tree mortality and associated NSC storage in Sitka-spruce (Picea sitchensis) trees dying under ecosystem-scale increases in seawater exposure in western Washington, USA. All trees exposed to seawater, because of monthly tidal intrusion, experienced declining crown foliage during the sampling period, and individuals with a lower percentage of live foliated crown (PLFC) died faster. Tree PLFC was strongly correlated with subsurface salinity and needle ion contents. Total NSC concentrations in trees declined remarkably with crown decline, and reached extremely low levels at tree death (2.4% and 1.6% in leaves and branches, respectively, and 0.4% in stems and roots). Starch in all tissues was almost completely consumed, while sugars remained at a homeostatic level in foliage. The decreasing NSC with closer proximity to death and near zero starch at death are evidences that carbon starvation occurred during Sitka-spruce mortality during seawater exposure. Our results highlight the importance of carbon storage as an indicator of tree mortality risks under seawater exposure.

Clinical spectrum and risk factors for mortality among seawater and freshwater critically ill drowning patients: a French multicenter study.

BACKGROUND: Drowning is a global threat and one of the leading causes of injury around the world. The impact of drowning conditions including water salinity on patients' prognosis remains poorly explored in Intensive Care Units (ICUs) patients. METHODS: We conducted a retrospective multicenter study on patients admitted to 14 ICUs in the west of France from January 2013 to January 2020. We first compared demographic and clinical characteristics at admission as well as clinical courses of these patients according to the salinity of drowning water. Then, we aimed to identify variables associated with 28-day survival using a Cox proportional hazard model. RESULTS: Of the 270 consecutive included patients, drowning occurred in seawater in 199 patients (73.7%) and in freshwater in 71 patients (26.3%). Day-28 mortality was observed in 55 patients (20.4%). Freshwater was independently associated with 28-day mortality (Adjusted Hazard Ratio (aHR) 1.84 [95% Confidence Interval (CI) 1.03-3.29], p = 0.04). A higher proportion of freshwater patients presented psychiatric comorbidities (47.9 vs. 19.1%; p < 0.0001) and the etiology of drowning appeared more frequently to be a suicide attempt in this population (25.7 vs. 4.2%; p < 0.0001). The other factors independently associated with 28-day mortality were the occurrence of a drowning-related cardiac arrest (aHR 11.5 [95% CI 2.51-52.43], p = 0.0017), duration of cardiopulmonary resuscitation (aHR 1.05 [95% CI 1.03-1.07], p < 0.0001) and SOFA score at day 1 (aHR 1.2 [95% CI 1.11-1.3], p < 0.0001). CONCLUSIONS: In this large multicenter cohort, freshwater drowning patients had a poorer prognosis than saltwater drowning patients. Reasons for such discrepancies include differences in underlying psychiatric comorbidity, drowning circumstances and severities. Patients with initial cardiac arrest secondary to drowning remain with a very poor prognosis.

Nrf2 protects against seawater drowning-induced acute lung injury via inhibiting ferroptosis.

BACKGROUND: Ferroptosis is a new type of nonapoptotic cell death model that was closely related to reactive oxygen species (ROS) accumulation. Seawater drowning-induced acute lung injury (ALI) which is caused by severe oxidative stress injury, has been a major cause of accidental death worldwide. The latest evidences indicate nuclear factor (erythroid-derived 2)-like 2 (Nrf2) suppress ferroptosis and maintain cellular redox balance. Here, we test the hypothesis that activation of Nrf2 pathway attenuates seawater drowning-induced ALI via inhibiting ferroptosis. METHODS: we performed studies using Nrf2-specific agonist (dimethyl fumarate), Nrf2 inhibitor (ML385), Nrf2-knockout mice and ferroptosis inhibitor (Ferrostatin-1) to investigate the potential roles of Nrf2 on seawater drowning-induced ALI and the underlying mechanisms. RESULTS: Our data shows that Nrf2 activator dimethyl fumarate could increase cell viability, reduced the levels of intracellular ROS and lipid ROS, prevented glutathione depletion and lipid peroxide accumulation, increased FTH1 and GPX4 mRNA expression, and maintained mitochondrial membrane potential in MLE-12 cells. However, ML385 promoted cell death and lipid ROS production in MLE-12 cells. Furthermore, the lung injury became more aggravated in the Nrf2-knockout mice than that in WT mice after seawater drowning. CONCLUSIONS: These results suggested that Nrf2 can inhibit ferroptosis and therefore alleviate ALI induced by seawater drowning. The effectiveness of ferroptosis inhibition by Nrf2 provides a novel therapeutic target for seawater drowning-induced ALI.

Seawater Immersion Aggravates Early Mitochondrial Dysfunction and Increases Neuronal Apoptosis After Traumatic Brain Injury.

Traumatic brain injury (TBI) is a major cause of death and disability in naval warfare. Due to the unique physiochemical properties of seawater, immersion in it exacerbates TBI and induces severe neural damage and complications. However, the characteristics and underlying mechanisms of seawater-immersed TBI remain unclear. Mitochondrial dysfunction is a major cause of TBI-associated brain damage because it leads to oxidative stress, decrease in energy production, and apoptosis. Thus, the present study aimed to further elucidate the current understanding of the pathology of seawater-immersed TBI, particularly the role of mitochondrial dysfunction, using a well-defined rat model of fluid percussion injury and a stretch injury model comprising cultured neurons. The biochemical and pathological markers of brain-related and neuronal injuries were evaluated. Histological analysis suggested that seawater immersion enhanced brain tissue injury and induced a significant increase in apoptosis in rats with TBI. Additionally, lactate dehydrogenase release occurred earlier and at higher levels in stretched neurons at 24 h after seawater immersion, which was consistent with more severe morphological changes and enhanced apoptosis. Furthermore, seawater immersion induced more rapid decreases in mitochondrial membrane potential, adenosine triphosphate (ATP) content, and H+-ATPase activity in the cortices of TBI rats. In addition, the immunochemical results revealed that seawater immersion further attenuated mitochondrial function in neurons exposed to stretch injury. The increases in neuronal damage and apoptosis triggered by seawater immersion were positively correlated with mitochondrial dysfunction in both in vivo and in vitro models. Thus, the present findings strengthen the current understanding of seawater-immersed TBI. Moreover, because seawater immersion aggravates mitochondrial dysfunction and contributes to post-traumatic neuronal cell death, it is important to consider mitochondria as a therapeutic target for seawater-immersed TBI.

Carbon Nanotube Reinforced High Density Polyethylene Materials for Offshore Sheathing Applications.

Multiwall carbon nanotube (CNT)-filled high density polyethylene (HDPE) nanocomposites were prepared by extrusion and considered for their suitability in the offshore sheathing applications. Transmission electron microscopy was conducted to analyse dispersion after bulk extrusion. Monolithic and nanocomposite samples were subjected to accelerated weathering and photodegradation (carbonyl and vinyl indices) characterisations, which consisted of heat, moisture (seawater) and UV light, intended to imitate the offshore conditions. The effects of accelerated weathering on mechanical properties (tensile strength and elastic modulus) of the nanocomposites were analysed. CNT addition in HDPE produced environmentally resilient nanocomposites with improved mechanical properties. The energy utilised to extrude nanocomposites was also less than the energy used to extrude monolithic HDPE samples. The results support the mass substitution of CNT-filled HDPE nanocomposites in high-end offshore applications.

Susceptibility of Nanophyetus salmincola Cercariae to Formalin, Hydrogen Peroxide, and Seawater.

The ability of formalin, PEROX-AID (hydrogen peroxide), and seawater to kill waterborne Nanophyetus salmincola cercariae was evaluated in vitro. Newly emerged cercariae survived for extended periods in freshwater, with 53-73% survival occurring in negative control groups after 24 h. Exposure to dilutions of formalin reduced this survival time, with 0% of cercariae surviving after 30 min in 450 µL/L, 40 min in 225 µL/L, and 300 min in 113 µL/L. Exposure to PEROX-AID (hydrogen peroxide) for 1 h resulted in reduced cercarial survival (16.4%) only at the highest concentration (100 µL/L), compared with 100% survival in the untreated controls and all lesser concentrations. Exposure to dilutions of seawater resulted in reduced cercarial survival only at high salinities (15.2-30.3‰), where 10-min exposures resulted in 0-20% survival. These results provide insights into options for prophylactic water treatment at salmonid enhancement facilities that experience high mortalities due to infections with Nanophyetus salmincola. Further, the intolerance of live cercariae to high salinities indicates that exposure to fish occurs primarily in the freshwater portions of watersheds.

Localized salt-dependent aquagenic urticaria, a rare subtype of urticaria: a case report.

Summary: Aquagenic urticaria (AU) is a rare form of chronic inducible urticaria elicited by water at any temperature. We describe the case of a 25-year-old atopic woman who presented to our unit with a 4-year history of recurrent urticarial rashes, highly pruritic, confined to the neck and lower part of the face, occurring solely on contact with sea water. The lesions were reproduced by challenge tests with aqueous 3.5% NaCl and other hypertonic aqueous solutions but not with 20% glucose neither tap water. Our case supports the existence of a distinct salt-dependent subtype of aquagenic urticaria (SDAU), which seems to be triggered mostly by sea bathing, affects young women and has a characteristic localization on the inferior facial contours and neck. To the best of our knowledge, only eight cases of SDAU have been reported in the literature.

[Prevalence of acid burns among asylum seekers hosted in an initial reception centre as an example of health assessment in a fragile population]. / La prevalenza di causticazioni in un centro di prima accoglienza per richiedenti asilo come esempio di valutazione sanitaria in una popolazione fragile.

OBJECTIVES: to evaluate the prevalence of acid burns among asylum seekers hosted in an initial reception centre and to evaluate if the prevalence is reduced after the introduction of the European Union (EU) regulation No. 29 (14th September 2016) that indirectly reduced the permanence time of the subjects on board of boats. DESIGN: cross-sectional study. SETTING AND PARTICIPANTS: 10,627 asylum seekers hosted in the centre for initial reception of Piedmont and Valle d'Aosta Regions (Northern Italy) between June 2016 and May 2017. MAIN OUTCOME MEASURES: frequencies of health problems and prevalence of second and third grade acid burns identified on arrival. RESULTS: among the asylum seekers coming to the centre, about 25% suffered at least from a mild disease, mainly cutaneous, respiratory, or digestive; 69 acid burns were identified (prevalence: 6.7‰, 95%CI 5.2-8.3), mainly located in the lower limbs and in the glutes. Median time between disembarkation and treatment is 2 days. Prevalence is significantly higher in women compared to men and a not-significant 20% reduction was observed comparing the situation before and after the introduction of the EU regulation No. 29. CONCLUSION: an assessment of the health status of asylum seekers that takes into account more than the identification of the rare life-threatening or infective diseases allows to take prompt action and to invest economical resources in the fields where they are more useful. This would facilitate a good health care for asylum seekers, that is the basis of an efficient functioning of services for integration.

Losartan, a selective antagonist of AT1 receptor, attenuates seawater inhalation induced lung injury via modulating JAK2/STATs and apoptosis in rat.

Losartan is a selective antagonist of AngⅠ type (AT1) receptor of Angiotensin Ⅱ (Ang Ⅱ), which is widely used as a clinical medicine for the hypertension. Recent studies have shown that losartan was shown to protect from acute lung injury (ALI). However, the underlying mechanism remains unclear. The aim of this research was to clarify whether Ang Ⅱ participated in the inflammatory response of ALI induced by seawater inhalation, and whether losartan had the protective effects on ALI by blocking the combination of Ang Ⅱ and AT1 receptor. In the current study, the severity of lung injury and the inflammatory reactions during seawater drowning induced ALI were assessed. Besides, we also detected the activation of relative pathways such as NF-κB, JAK2/STATs and apoptosis. The results showed that seawater inhalation could up-regulate the expression of Ang Ⅱ and AT1. While pretreatment of losartan (especially 15 mg/kg and 30 mg/kg) alleviated lung injury by inhibiting Ang-Ⅱ and AT1 receptor combination and in turn decreased the expression of p-NF-κB and activation of JAK2/STATs pathway. We also confirmed that losartan could reduce the apoptotic ratio of cells in the lung by modulating the phosphorylation of JNK and leak of cytochrome C to cytosol. Taken together, these findings demonstrate that losartan might have a therapeutic potential as an anti-inflammatory agent for treating SWI-ALI.

Physiological and behavioral responses to salinity in coastal Dice snakes.

Secondarily marine tetrapods have evolved adaptations to maintain their osmotic balance in a hyperosmotic environment. During the transition to a marine habitat, the evolution of a euryhaline physiology likely encompassed successive changes in behavior and physiology that released organisms from regular access to fresh water. Deciphering these key steps is a complicated task. In this study, we investigated a species of freshwater natricine snake in which some populations are known to use marine environments. We experimentally subjected 30 adult Dice snakes (Natrix tessellata) from a population inhabiting the Black Sea coast to three salinities corresponding to freshwater (~0.1‰), brackish water (~15.0‰), and full-strength seawater (~34.0‰) in order to investigate their physiological (variation of body mass, osmolality) and behavioral (activity, drinking behavior) responses to salinity. Our results show that coastal Dice snakes from the study population are relatively tolerant to salinity close to that recorded in the Black Sea, but that prolonged exposure to full-strength seawater increases osmolality, stimulates thirst, decreases the activity of snakes and may ultimately jeopardize survival. Collectively with previously published data, our results strongly suggest specific physiological adaptations to withstand hyperosmolality rather than to reduce intake of salt, in coastal populations or species of semi-aquatic snakes. Future comparative investigations of Dice snakes from populations restricted to freshwater environment might reveal the functional traits and the behavioral and physiological responses of coastal N. tessellata to life in water with elevated salinity.

Risk assessment of human health from exposure to the discharged ballast water after full-scale electrolysis treatment.

The presence of disinfection by-products (DBPs) releasing from ballast water management systems (BWMS) can cause a possible adverse effects on humans. The objectives of this study were to compute the Derived No Effect Levels (DNELs) for different exposure scenarios and to compare these levels with the exposure levels from the measured DBPs in treated ballast water. The risk assessment showed that when using animal toxicity data, all the DNELs values were approximately 10(3)-10(12) times higher than the exposure levels of occupational and general public exposure scenarios, indicating the level of risk was low (risk characterization ratios (RCRs) < 1). However, when using human data, the RCRs were higher than 1 for dichlorobromomethane and trichloromethane, indicating that the risk of adverse effects on human were significant. This implies that there are apparent discrepancies between risk characterization from animal and human data, which may affect the overall results. We therefore recommend that when appropriate, human data should be used in risk assessment as much as possible, although human data are very limited. Moreover, more appropriate assessment factors can be considered to be employed in estimating the DNELs for human when the animal data is selected as the dose descriptors.

The water penetration of different ventilation tubes.

The insertion of middle ear ventilation tubes remains one of the most common procedures for ENT surgeons. A common concern amongst patients undergoing such procedures is the effect on their ability to partake in swimming and other water sports. Currently there is little evidence comparing the penetration ability of different water solutions encountered by swimmers. This study compares the water penetration of four different water solutions for Shah, mini-Shah, T tube and titanium bobbin ventilation tubes. A model was constructed to replicate a grommet inserted through a tympanic membrane using a syringe barrel, latex membrane and one of the ventilation tubes. Four solutions (sea water, chlorinated water, freshwater and soapy water) were then pipetted down the barrel until penetration of the tube occurred. The volume required for penetration was recorded. For all tubes soapy water was the most penetrating, followed by seawater. Titanium bobbins required significantly less of each solution for penetration. Mini-Shah grommets required significantly more of all solutions except soapy water for penetration to occur. Shah grommets were more resistant to chlorinated and sea water than T tubes. Mini-Shah grommets appear to protect against water penetration into the middle ear cleft and their use should be considered in patients who are keen water-sport enthusiasts. Furthermore, swimmers in sea or chlorinated water seem to be at higher risk than freshwater swimmers. Titanium bobbins were relatively easily penetrated by all four solutions and should be avoided in keen swimmers.

Application of vacuum-assisted closure in seawater-immersed wound treatment under different negative pressures.

The therapeutic effect of vacuum-assisted closure (VAC) has been confirmed in many types of complex wounds, but there are few relevant reports regarding seawater-immersed wounds. The aim of this study was to determine the effect of VAC on seawater-immersed wound healing under different negative pressures and explore the optimal negative pressure value. Four purebred miniature pigs were used as the experimental animal models. Four acute, symmetrical wounds were made on each side of the spine and designated as the experimental group (wounds with 2 h of seawater immersion) and the control group (wounds without seawater immersion). Wounds were divided into a conventional dressing group and 3 further groups with different VAC therapies (negative pressure at either 120, 180, or 240 mmHg). The extent of wound healing, and speed of granulation growth and re-epithelialization were measured. Bacterial flora distribution in the wounds was observed, and fibronectin levels in the exudate of the wounds were tested. Results showed that seawater immersion aggravated wound injury and that VAC therapy with 180 mmHg negative pressure induced the fastest epidermis migration, obvious edema elimination, significant capillary proliferation, and the highest level of fibronectin, and that in wounds, the proportion of Gram-negative bacteria tended to decrease and that of Gram-positive bacteria tended to increase. Our results show that VAC promotes seawater-immersed wound healing and that 180 mmHg negative pressure may be optimal for wound healing.

Risk Factors for Vibrio parahaemolyticus Infection in a Southern Coastal Region of China.

OBJECTIVES: The objectives of the study were to identify dietary and medical risk factors for Vibrio parahaemolyticus (VP) infection in the coastal city Shenzhen in China. METHODS: In April-October 2012, we conducted a case-control study in two hospitals in Shenzhen, China. Laboratory-confirmed VP cases (N = 83) were matched on age, sex, and other social factors to healthy controls (N = 249). Subjects were interviewed using a questionnaire on medical history; contact with seawater; clinical symptoms and outcome; travel history over the past week; and dietary history 3 days prior to onset. Laboratory tests were used to culture, serotype, and genotype VP strains. We used logistic regression to calculate the odds ratios for the association of VP infection with potential risk factors. RESULTS: In multivariate analysis, VP infection was associated with having pre-existing chronic disease (adjusted odds ratio [aOR], 6.0; 95% confidence interval [CI], 1.5-23.7), eating undercooked seafood (aOR, 8.0; 95% CI, 1.3-50.4), eating undercooked meat (aOR, 29.1; 95% CI, 3.0-278.2), eating food from a street food vendor (aOR, 7.6; 95% CI, 3.3-17.6), and eating vegetable salad (aOR, 12.1; 95% CI, 5.2-28.2). CONCLUSIONS: Eating raw (undercooked) seafood and meat is an important source of VP infection among the study population. Cross-contamination of VP in other food (e.g., vegetables and undercooked meat) likely plays a more important role. Intervention should be taken to lower the risks of cross-contamination with undercooked seafood/meat, especially targeted at people with low income, transient workers, and people with medical risk factors.

[Localized salt-dependent aquagenic urticaria: A case report]. / Urticaire aquagénique localisée à l'eau de mer.

BACKGROUND: Aquagenic urticaria is a rare but well-known form of physical urticaria mainly affecting young women. It is characterised by the appearance of erythematous and pruritic plaques a few minutes after initial contact with water and irrespective of temperature. The physiopathology of this condition remains poorly understood. Herein, we report a case of localised aquagenic urticaria occurring solely on contact with seawater. PATIENTS AND METHODS: A 32-year-old woman reported onset of erythematous and pruritic plaques, confined to the neck and lower part of the face, several minutes after the start of bathing in seawater. Skin tests were carried out by applying wet compresses soaked in seawater (37°C for 30 min) to the areas in which the skin reaction usually occurred. A control test using a compress soaked in fresh water was carried out under identical conditions. An urticaria reaction was noted in the areas in contact with seawater, but no reaction was seen in the areas coming into contact with fresh water. Antihistamines taken on the days of bathing proved ineffective. DISCUSSION: A number of similar cases have been reported in the literature, enabling the characterisation of this particular form of aquagenic urticaria and allowing its principal characteristics to be defined. It appears to be dependent solely on the salt content of the water. It is reported by young women while bathing in seawater. The urticaria plaques show a predilection for the neck and lower part of the face, as in our case, as well as the shoulders on occasion. The efficacy of antihistamines is inconsistent. The prevalence of this as yet poorly known entity is doubtless underreported.

Inverse modulation of the energy sensor Snf1-related protein kinase 1 on hypoxia adaptation and salt stress tolerance in Arabidopsis thaliana.

Terrestrial plants are exposed to complex stresses of high salt-induced abscisic acid (ABA) and submergence-induced hypoxia when seawater floods fields. Many studies have investigated plant responses to individual stress conditions, but not so much for coupled or sequentially imposed stresses. We examined molecular regulatory mechanisms of gene expression underlying the cellular responses involved in crosstalk between salt and hypoxia stresses. Salt/ABA- and AtMYC2-dependent induction of a synthetic ABA-responsive element and the native RD22 promoters were utilized in our cell-based functional assays. Such promoter-based reporter induction was largely inhibited by hypoxia and hypoxia-inducible AKIN10 activity. Biochemical analyses showed that AKIN10 negatively modulates AtMYC2 protein accumulation via proteasome activity upon AKIN10 kinase activity-dependent protein modification. Further genetic analysis using transgenic plants expressing AKIN10 provided evidence that AKIN10 activity undermined AtMYC2-dependent salt tolerance. Our findings unravel a novel molecular interaction between the key signalling constituents leading crosstalk between salt and hypoxia stresses in Arabidopsis thaliana under the detrimental condition of submergence in saltwater.

Effect of seawater desalination and oil pollution on the lipid composition of blue mussels Mytilus edulis L. from the White Sea.

A study on the effect oil pollution under normal and reduced salinity had on blue mussels Mytilus edulis L. from the White Sea in an aquarium-based experiment and in the natural habitat revealed a change in gill total lipids as a compensatory response. The cholesterol concentration and the cholesterol/phospholipids ratio in gills were found to reflect the impact of the environmental factors (oil pollution and desalination), and evidence adaptive changes in the cell membrane structure. An elevated content of storage lipids (chiefly triacylglycerols) in the mussels in the aquarium experiment indicates, first of all, the uptake and accumulation of oil products in gill cells under both normal and reduced seawater salinity, while high triacylglycerols level in gill littoral mussels from 'control' biotope in the Gulf of Kandalaksha is primarily associated with the mussel׳s pre-spawning period.

Dermatological problems of asylum seekers arriving on boats: a case report from Australia and a brief review.

Assessing the skin of asylum seekers, immigrants, migrant workers, tourists or even locals who return from abroad, can be a confronting task due to the possibility of such people having non-autochthonous diseases. Primary-care physicians and dermatologists need to have a systematic approach in the assessment of such dermatoses. This article describes an interesting case of possible kerosene-induced and diesel-induced skin injury in an asylum seeker arriving on a boat. Dermatological conditions in asylum seekers and a suggested template for skin assessment are discussed.