Ellagic acid protects type II collagen induced arthritis in rat via diminution of IKB phosphorylation and suppression IKB-NF-kB complex activation: in vivo and in silico study.

OBJECTIVE: The present study was designed to explore the potential anti-inflammatory and anti-arthritic effects of ellagic acid (EA) in collagen-induced arthritis (CIA). METHODS: CIA rats were treated with MTX (0.25 mg/kg body wt.) and EA (50 mg/kg b.wt.) for a period of 20 days. The effects of treatment in the rats were assessed biochemically by analyzing inflammatory mediators (NF-kB, iNOS, TNF-α, IL-1ß, IL-6 and IL-10) and oxidative stress related parameters (MPO, NO, LPO, catalase, SOD, GSH). In addition, we also assessed the expression of some inflammatory mediators TNF-α, CD8 + though immunohistochemistry in the joint tissue. RESULTS: In the present study, we found expression and synthesis of transcription factor NF-kB was prominent in CIA rats. In addition, main pro-inflammatory cytokines such as TNF-α, IL-1ß, IL-6, and the anti-inflammatory IL-10, was also stand out. Further, reactive oxygen/nitrogen species was also elevated in CIA rats. Treatment with EA ameliorates all the above mentioned inflammatory and oxidative stress related parameters to near normal. Further, we also confirmed the expression of TNF-α, CD8+ T cells through immunohistochemistry was mitigates in joint tissue of EA treated rats. We find EA significantly inhibited the developmental phase of arthritis. CONCLUSION: These results suggest that EA act as potent anti-arthritic and anti-inflammatory agent that could be used as a tool for the development of new drug for the treatment of arthritis.

Clinical efficacy evaluation of 595-nm pulsed dye lasers, microwave tissue coagulation, and liquid nitrogen cryotherapy in the treatment of verruca vulgaris in children.

OBJECTIVE: To evaluate the clinical efficacy and safety of 595-nm pulsed dye laser in the treatment of verruca vulgaris in children and to compare the efficacy of this method against two other methods, microwave tissue coagulation and liquid nitrogen cryotherapy. METHODS: A total of 90 children being treated in the dermatology outpatient department of our hospital from 2019 to 2021 were selected and divided into three groups: the treatment group A (n = 30, treated with a 595-nm pulsed dye laser), treatment group B (n = 30, treated with microwave tissue coagulation), and treatment group C (n = 30, treated with liquid nitrogen cryotherapy). All the patients in the treatment group A, treatment group B, and treatment group C were treated once every two weeks, with a maximum of six treatments. RESULTS: The response rate of the treatment group A was 93.3%, which was higher than the 83.3% rate of treatment group B and the 66.7% rate of treatment group C. The average treatment times of the treatment group A (2.45 ± 1.10) were lower than group B (3.51 ± 0.98) and group C (4.63 ± 0.96). The adverse reaction rate in the treatment group A (16.7%) was significantly lower than that in treatment group B (56.7%) and treatment group C (63.3%). The differences were statistically significant (all p < 0.05). CONCLUSIONS: The 595-nm pulsed dye laser is safe and seems to be the most effective treatment for verruca vulgaris in children. Further high-level clinical trial is warranted to verify our results.

Ionic homeostasis, biochemical components and yield of Italian zucchini under nitrogen forms and salt stress / Homeostase iônica, componentes bioquímicos e produção da abobrinha italiana sob formas de nitrogênio e estresse salino

This research was carried out aiming at evaluating the effects of nitrate and ammonium ions on nutrient accumulation, biochemical components and yield of Italian zucchini (cv. Caserta) grown in a hydroponic system under salt stress conditions. The experiment was carried out in a greenhouse utilizing an experimental design in randomized blocks, arranged in a 2 x 5 factorial scheme, with 4 replications. The treatments consisted of two forms of nitrogen (nitrate - NO3- and ammonium - NH4+) and 5 electrical conductivity levels of irrigation water (ECw) (0.5, 2.0, 3.5, 5.0 and 6.5 dS m-1). The analysis of the results indicated that supply of N exclusively in NH4+ form promotes greater damage to the leaf membrane and reduction in accumulation of macronutrients and higher Na+/K+, Na+/Ca++ and Na+/Mg++ ratios in the shoots of zucchini plants. Electrical conductivity of irrigation water above 2.0 dS m-¹ reduces the accumulation of nutrients in shoot and yield of Italian zucchini plant. The toxicity of NH4+ under Italian zucchini plants overlap the toxicity of the salinity, since its fertilization exclusively with this form of nitrogen inhibits its production, being the NO3- form the most suitable for the cultivation of the species.

Este trabalho foi desenvolvido com o objetivo de avaliar os efeitos dos íons nitrato e amônio sobre o acúmulo de nutrientes e produção da abobrinha italiana (cv. Caserta) cultivada em sistema hidropônico sob estrese salino. O experimento foi conduzido em casa de vegetação utilizando o delineamento experimental em blocos casualizados, arranjados em esquema fatorial 2 x 5, com 4 repetições. Os tratamentos foram constituídos de duas formas de nitrogênio (nitrato - NO3- e amônio - NH4+) e cinco níveis de condutividade elétrica da água de irrigação (CEa) (0,5; 2,0; 3,5; 5,0 e 6,5 dS m-¹). As análises dos resultados indicaram que suprimento de N exclusivamente em forma de NH4+ promove maiores danos na membrana foliar e redução no acúmulo de macronutrientes e maiores relações Na+/K+, Na+/Ca++ e Na+/Mg++ na parte aérea das plantas de abobrinha. A irrigação com água a cima de 2,0 dS m-¹ reduz o acúmulo de nutrientes na parte aérea das plantas e a produção de abobrinha. A toxicidade do NH4+ sob abobrinha italiana sobrepõe-se à toxicidade da salinidade, pois a fertilização exclusiva com esta forma de nitrogênio inibe sua produção, sendo a forma NO3- a mais adequada para o cultivo da espécie.

Large-Scale Image Analysis for Investigating Spatio-Temporal Changes in Nuclear DNA Damage Caused by Nitrogen Atmospheric Pressure Plasma Jets.

The effective clinical application of atmospheric pressure plasma jet (APPJ) treatments requires a well-founded methodology that can describe the interactions between the plasma jet and a treated sample and the temporal and spatial changes that result from the treatment. In this study, we developed a large-scale image analysis method to identify the cell-cycle stage and quantify damage to nuclear DNA in single cells. The method was then tested and used to examine spatio-temporal distributions of nuclear DNA damage in two cell lines from the same anatomic location, namely the oral cavity, after treatment with a nitrogen APPJ. One cell line was malignant, and the other, nonmalignant. The results showed that DNA damage in cancer cells was maximized at the plasma jet treatment region, where the APPJ directly contacted the sample, and declined radially outward. As incubation continued, DNA damage in cancer cells decreased slightly over the first 4 h before rapidly decreasing by approximately 60% at 8 h post-treatment. In nonmalignant cells, no damage was observed within 1 h after treatment, but damage was detected 2 h after treatment. Notably, the damage was 5-fold less than that detected in irradiated cancer cells. Moreover, examining damage with respect to the cell cycle showed that S phase cells were more susceptible to DNA damage than either G1 or G2 phase cells. The proposed methodology for large-scale image analysis is not limited to APPJ post-treatment applications and can be utilized to evaluate biological samples affected by any type of radiation, and, more so, the cell-cycle classification can be used on any cell type with any nuclear DNA staining.

Is a 12-h Nitrox dive hazardous for pulmonary function?

PURPOSE: Prolonged exposure to a high partial pressure of oxygen leads to inflammation of pulmonary tissue [pulmonary oxygen toxicity (POT)], which is associated with tracheobronchial irritation, retrosternal pain and coughing, and decreases in vital capacity (VC). The nitric oxide (NO) concentration in exhaled gas (FeNO) has been used as an indicator of POT, but the effect of SCUBA diving on FeNO has rarely been studied. The study presented here aimed to assess alterations to pulmonary function and FeNO following a 12-h dive using breathing apparatus with a relatively high partial pressure of oxygen. METHODS: Six healthy, male, non-smoking military SCUBA divers were recruited (age 31.8 ± 2.7 years, height 179 ± 0.09 cm, and body weight 84.6 ± 14 kg). Each diver completed a 12-h dive using a demand-controlled semi-closed-circuit rebreather. During the 12 h of immersion, divers were subjected to 672 oxygen toxicity units (OTU). A complete pulmonary function test (PFT) was completed the day before and immediately after immersion. FeNO was measured using a Nobreath™ Quark (COSMED™, Rome, Italy), three times for each diver. The first datapoint was collected before the dive to establish the "basal state", a second was collected immediately after divers emerged from the water, and the final measurement was taken 24 h after the dive. RESULT: Despite prolonged inhalation of a hyperoxic hyperbaric gas mixture, no clinical pulmonary symptoms were observed, and no major changes in pulmonary function were detected. However, a major decrease in FeNO values was observed immediately after emersion [0-12 ppb (median, 3.8 ppb)], with a return to baseline [2-60 ppb (median, 26 ppb) 24 h later (3-73 ppb (median, 24.7 ppb)]. CONCLUSION: These results suggest that if the OTU remain below the recommended limit values, but does alter FeNO, this type of dive does not persistently impair lung function.

Perforación gástrica asociada al consumo de helado con nitrógeno líquido / Gastric perforation associated with the intake of ice cream with liquid nitrogen

La ingestión de nitrógeno líquido es una causa infrecuente de perforación gástrica, se conoce poco sobre como este compuesto afecta el tejido gastrointestinal, sus mecanismos de lesión y sus consecuencias clínicas. Cada vez es más frecuente el uso del nitrógeno líquido de forma comercial en productos de repostería y gastronomía, por lo que es importante reconocer sus potenciales efectos cuando la manipulación no es la adecuada. En este caso clínico describimos una perforación gástrica secundaria al consumo de helado preparado con nitrógeno líquido.

Liquid nitrogene ingestion is a frecuent cause of gastric perforation. It is unknown how this compound afects the gatrointestinal tissue, it mechanisisms of injury and the clinical consecuences. Nowadays, the use of liquid nitrogene in gastronomy is becoming a tendency, for this reason it is important to identify the potencial healt effects of this compound when is not correctly manipulated. The following article describes a secondary gastric perforation, as a consecuence of the consumption of ice cream prepared with liquid nitrogene.

Early detection of diving-related cognitive impairment of different nitrogen-oxygen gas mixtures using critical flicker fusion frequency.

INTRODUCTION: Cognitive impairment related to inert gas narcosis (IGN) is a threat to diving safety and operations at depth that might be reduced by using enriched air nitrox (EANx) mixtures. Using critical flicker fusion frequency (CFFF), a possible early detection of cognitive abilities/cerebral arousal impairment when breathing different oxygen (O2) fractions was investigated. METHODS: Eight male volunteers performed, in random order, two dry chamber dives breathing either air or EANx40 (40% O2-60% nitrogen) for 20 minutes (min) at 0.4 MPa. Cognition and arousal were assessed before the dive; upon arrival at 0.4 MPa; after 15 min exposure at 0.4 MPa; on surfacing and 30 min post-dive using behavioural computer-based testing psychology experiment building language (PEBL) and by CFFF while continuously recording brain oxygenation with near-infrared spectroscopy. RESULTS: In both breathing conditions, CFFF and PEBL demonstrated a significant inverse correlation (Pearson r of -0.90, P < 0.0001), improved cognitive abilities/cerebral arousal occurred upon arrival at 0.4 MPa followed by a progressive deterioration. Initial brain activation was associated with a significant increase in oxyhaemoglobin (HbO2) and a simultaneous decrease of deoxyhaemoglobin (HHb). The magnitude of the changes was significantly greater under EANx (P = 0.038). CONCLUSIONS: Since changes were not related to haemodynamic variables, HbO2 and HHb values indicate a significant, O2-dependent activation in the prefrontal cortex. Owing to the correlation with some tests from the PEBL, CFFF could be a convenient measure of cognitive performance/ability in extreme environments, likely under the direct influence of oxygen partial pressure, a potent modulator of IGN symptoms.

Nitrogen gas produces less behavioural and neurophysiological excitation than carbon dioxide in mice undergoing euthanasia.

Carbon dioxide (CO2) is one of the most commonly used gas euthanasia agents in mice, despite reports of aversion and nociception. Inert gases such as nitrogen (N2) may be a viable alternative to carbon dioxide. Here we compared behavioural and electrophysiological reactions to CO2 or N2 at either slow fill or rapid fill in C57Bl/6 mice undergoing gas euthanasia. We found that mice euthanised with CO2 increased locomotor activity compared to baseline, whereas mice exposed to N2 decreased locomotion. Furthermore, mice exposed to CO2 showed significantly more vertical jumps and freezing episodes than mice exposed to N2. We further found that CO2 exposure resulted in increased theta:delta of the EEG, a measure of excitation, whereas the N2 decreased theta:delta. Differences in responses were not oxygen-concentration dependent. Taken together, these results demonstrate that CO2 increases both behavioural and electrophysiological excitation as well as producing a fear response, whereas N2 reduces behavioural activity and central neurological depression and may be less aversive although still produces a fear response. Further studies are required to evaluate N2 as a suitable euthanasia agent for mice.

Inert gas narcosis in scuba diving, different gases different reactions.

PURPOSE: Underwater divers face several potential neurological hazards when breathing compressed gas mixtures including nitrogen narcosis which can impact diver's safety. Various human studies have clearly demonstrated brain impairment due to nitrogen narcosis in divers at 4 ATA using critical flicker fusion frequency (CFFF) as a cortical performance indicator. However, recently some authors have proposed a probable adaptive phenomenon during repetitive exposure to high nitrogen pressure in rats, where they found a reversal effect on dopamine release. METHODS: Sixty experienced divers breathing Air, Trimix or Heliox, were studied during an open water dive to a depth of 6 ATA with a square profile testing CFFF measurement before (T0), during the dive upon arriving at the bottom (6 ATA) (T1), 20 min of bottom time (T2), and at 5 m (1.5 ATA) (T3). RESULTS: CFFF results showed a slight increase in alertness and arousal during the deep dive regardless of the gas mixture breathed. The percent change in CFFF values at T1 and T2 differed among the three groups being lower in the air group than in the other groups. All CFFF values returned to basal values 5 min before the final ascent at 5 m (T3), but the Trimix measurements were still slightly better than those at T0. CONCLUSIONS: Our results highlight that nitrogen and oxygen alone and in combination can produce neuronal excitability or depression in a dose-related response.

Cyanobacterial Toxins of the Laurentian Great Lakes, Their Toxicological Effects, and Numerical Limits in Drinking Water.

Cyanobacteria are ubiquitous phototrophic bacteria that inhabit diverse environments across the planet. Seasonally, they dominate many eutrophic lakes impacted by excess nitrogen (N) and phosphorus (P) forming dense accumulations of biomass known as cyanobacterial harmful algal blooms or cyanoHABs. Their dominance in eutrophic lakes is attributed to a variety of unique adaptations including N and P concentrating mechanisms, N2 fixation, colony formation that inhibits predation, vertical movement via gas vesicles, and the production of toxic or otherwise bioactive molecules. While some of these molecules have been explored for their medicinal benefits, others are potent toxins harmful to humans, animals, and other wildlife known as cyanotoxins. In humans these cyanotoxins affect various tissues, including the liver, central and peripheral nervous system, kidneys, and reproductive organs among others. They induce acute effects at low doses in the parts-per-billion range and some are tumor promoters linked to chronic diseases such as liver and colorectal cancer. The occurrence of cyanoHABs and cyanotoxins in lakes presents challenges for maintaining safe recreational aquatic environments and the production of potable drinking water. CyanoHABs are a growing problem in the North American (Laurentian) Great Lakes basin. This review summarizes information on the occurrence of cyanoHABs in the Great Lakes, toxicological effects of cyanotoxins, and appropriate numerical limits on cyanotoxins in finished drinking water.

Long term storage in liquid nitrogen leads to only minor phenotypic and gene expression changes in the mammary carcinoma model cell line BT474.

BACKGROUND/AIM: Cancer cell lines are indispensible surrogate models in cancer research, as they can be used off-the-shelf, expanded to the desired extent, easily modified and exchanged between research groups for affirmation, reproduction or follow-up experiments.As malignant cells are prone to genomic instability, phenotypical changes may occur after certain passages in culture. Thus, cell lines have to be regularly authenticated to ensure data quality. In between experiments these cell lines are often stored in liquid nitrogen for extended time periods.Although freezing of cells is a necessary evil, little research is performed on how long-term storage affects cancer cell lines. Therefore, this study investigated the effects of a 28-year long liquid nitrogen storage period on BT474 cells with regard to phenotypical changes, differences in cell-surface receptor expression as well as cytokine and gene expressional variations. METHODS: Two batches of BT474 cells, one frozen in 1986, the other directly purchased from ATCC were investigated by light microscopy, cell growth analysis, flow cytometry and cytokine as well as whole-transcriptome expression profiling. RESULTS: The cell lines were morphologically indifferent and showed similar growth rates and similar cell-surface receptor expression. Transcriptome analysis revealed significant differences in only 26 of 40,716 investigated RefSeq transcripts with 4 of them being up-regulated and 22 down-regulated. CONCLUSION: This study demonstrates that even after very long periods of storage in liquid nitrogen, cancer cell lines display only minimal changes in their gene expression profiles. However, also such minor changes should be carefully assessed before continuation of experiments, especially if phenotypic alterations can be additionally observed.

Diving under the influence: issues in researching personality and inert gas narcosis.

BACKGROUND: This paper considers the relationship between measures of personality and mood states, and susceptibility to inert gas narcosis. It briefly reviews the topics of inert gas narcosis affecting personality, and personality affecting the susceptibility to inert gas narcosis. There appears to be is a theoretical argument for a possible relationship between measures of personality, mood states, and susceptibility to narcosis. Practically, such a relationship may speak to issues in selection, training and preparation, risk assessments, and even accident investigation in the diving and/or hyperbaric environment. MATERIALS AND METHODS: Twenty one divers completed measures of personality and mood states, and were then compressed to 709 kPa (equivalent to 60 msw) in a dry compression chamber, where they completed a task measuring speed of information processing, and a scale measuring subjective narcosis. RESULTS AND CONCLUSIONS: The main finding was the absence of any significant correlations between measures of personality traits and mood, and susceptibility to inert gas narcosis. Although the study found no evidence of any major relationship, it is presented as a case study to highlight some of the issues and pitfalls involved in such research. The lessons learned - including the careful defining and describing of concepts, and choosing of samples and measurements - are used to discuss some of the methodological and conceptual issues and future directions for researchers to consider.

Cellulitis Secondary to Liquid Nitrogen Cryotherapy: Case Report and Literature Review.

BACKGROUND: Liquid nitrogen cryotherapy is a commonly used technique to treat a wide variety of dermatologic conditions including actinic keratoses, non-melanoma skin cancers, verrucae, and seborrheic keratoses. The risks associated with liquid nitrogen cryotherapy are important to know and discuss with patients prior to treatment. OBJECTIVE: We report a case of cellulitis secondary to liquid nitrogen cryotherapy for actinic keratosis. We sought to review the literature for an estimate of secondary infection rates following cryotherapy treatment. METHODS: We searched Pubmed using the terms cryotherapy and infection or cellulitis. We then looked at articles classified as clinical trials where cryotherapy was used to treat skin conditions. We then selected clinical trials that listed cellulitis or infection as an adverse event. RESULTS AND CONCLUSION: There were no case reports, case series, or review articles detailing the risk of infection from liquid nitrogen cryotherapy. We found 8 articles classified as clinical trials on Pubmed that did list infection as an adverse event. The risk of infection from these studies varied from approximately 2% to 30%. There was a great degree of heterogeneity in treatment sites, length of treatment, and treatment targets. While it is difficult to determine the true incidence of infection from liquid nitrogen cryotherapy, clinicians should endeavor to inform patients of this potential risk.

Neurochemistry of Pressure-Induced Nitrogen and Metabolically Inert Gas Narcosis in the Central Nervous System.

Gases that are not metabolized by the organism are thus chemically inactive under normal conditions. Such gases include the "noble gases" of the Periodic Table as well as hydrogen and nitrogen. At increasing pressure, nitrogen induces narcosis at 4 absolute atmospheres (ATAs) and more in humans and at 11 ATA and more in rats. Electrophysiological and neuropharmacological studies suggest that the striatum is a target of nitrogen narcosis. Glutamate and dopamine release from the striatum in rats are decreased by exposure to nitrogen at a pressure of 31 ATA (75% of the anesthetic threshold). Striatal dopamine levels decrease during exposure to compressed argon, an inert gas more narcotic than nitrogen, or to nitrous oxide, an anesthetic gas. Inversely, striatal dopamine levels increase during exposure to compressed helium, an inert gas with a very low narcotic potency. Exposure to nitrogen at high pressure does not change N-methyl-d-aspartate (NMDA) glutamate receptor activities in Substantia Nigra compacta and striatum but enhances gama amino butyric acidA (GABAA) receptor activities in Substantia Nigra compacta. The decrease in striatal dopamine levels in response to hyperbaric nitrogen exposure is suppressed by recurrent exposure to nitrogen narcosis, and dopamine levels increase after four or five exposures. This change, the lack of improvement of motor disturbances, the desensitization of GABAA receptors on dopamine cells during recurrent exposures and the long-lasting decrease of glutamate coupled with the higher sensitivity of NMDA receptors, suggest a nitrogen toxicity induced by repetitive exposures to narcosis. These differential changes in different neurotransmitter receptors would support the binding protein theory. © 2016 American Physiological Society. Compr Physiol 6:1579-1590, 2016.

Tolerability and effectiveness of liquid nitrogen spray cryotherapy with very short freeze times in the treatment of xanthelasma palpebrarum.

Xanthelasma are cholesterol-filled, soft, yellow plaques that usually appear on the medial aspects of the eyelids bilaterally. They are always benign lesions so therapy is usually undertaken only for cosmetic reasons. Surgical excision, chemical peeling with tricholoroacetic acid, and laser ablation are commonly used treatments. Liquid nitrogen cryotherapy is a potentially effective but rarely used treatment due to the risk of intense eyelid swelling. We report on our experience with four of our patients, and propose an explanation for the effectiveness of gentle liquid nitrogen spray cryotherapy in xanthelasma. We consider that gentle liquid nitrogen cryotherapy should be used in the treatment of xanthelasma due to the ease of application and low risk of adverse effects.

[Effects of simulated nitrogen-oxygen saturation exposure at a water depth of 50m on expression of inflammatory mediators in external auditory canal of rabbits].

OBJECTIVE: To investigate the effects of simulated nitrogen-oxygen saturation exposure at a water depth of 50 m on the expression of inflammatory mediators including interleukin-6 (IL-6), interleukin-10 (IL-10), and tumor necrosis factor-alpha (TNF-α) in the external auditory canal (EAC) of rabbits. METHODS: Two batches of New Zealand rabbits were exposed to nitrogen-oxygen saturated at a water depth of 50 m. After exposure, the epithelial tissue in the EAC was analyzed using hematoxylin-eosin (HE) staining, and the changes in expression of inflammatory mediators including IL-6, IL-10, and TNF-α in the EAC of rabbits were determined by real-time polymerase chain reaction (PCR). RESULTS: According to the result of HE staining, more inflammatory cell infiltration, small vascular congestion, and mucosal edema in the EAC of rabbits were observed in the exposure group than in the control group. Additionally, compared with the control group, the exposure group had increased expression of IL-6 and TNF-α and reduced expression of IL-10 in the EAC of rabbits according to the result of real-time PCR. CONCLUSION: The nitrogen-oxygen saturation exposure at a water depth of 50 m can cause inflammatory injuries in the EAC of rabbits. The mechanism may be associated with increased expression of IL-6 and TNF-α and reduced expression of IL-10.

Atypical histopathologic features in a melanocytic nevus after cryotherapy and pregnancy.

Melanocytic nevi can undergo clinical and histopathologic changes during pregnancy, as well as after various forms of surgical and nonsurgical trauma. We report the case of a 9-month postpartum 29-year-old female who presented to her dermatologist with a clinically worrisome nevus. This nevus had been treated with liquid nitrogen by her primary care physician 6 months prior to presentation. Histopathologic evaluation revealed a crowded proliferation of atypical melanocytes at the dermal-epidermal junction overlying a scar. The dermal component contained scattered mitotic figures. A combined MART-1, tyrosinase and Ki-67 immunohistochemical study showed foci of increased melanocytic proliferation. These atypical features were interpreted as associated with both the prior cryotherapy, as well as her recent pregnancy. Knowledge of the clinical context in evaluating difficult melanocytic lesions is essential.

Impairment from gas narcosis when breathing air and enriched air nitrox underwater.

BACKGROUND: Nitrogen (N2) in air causes cognitive impairment from gas narcosis when breathed at increased ambient pressures. This impairment might be reduced by using enriched air nitrox (EANx) mixtures, which have a higher oxygen and lower N2 content compared to air. This study aimed to investigate if divers differed in memory ability and self-assessment when breathing air and EANx30. METHODS: The effect of depth (shallow vs. deep) and breathing gas (air vs. EANx30) on memory ability and subjective ratings of impairment was compared in 20 divers. RESULTS: Memory performance was significantly worse in deep water (Air: M = 22.1%, SD = 21.7%; EANx30: M = 22.1%, SD = 17.2%) compared to shallow water (Air: M = 29.2%, SD = 18.3%; EANx30: M = 33.3%, SD = 18.2%), but this impairment did not differ significantly between air and EANx30. Subjective ratings of impairment increased significantly from shallow water (Air: M = 5.2, SD = 5.9; EANx30: M = 3.0, SD = 4.4) to deep water (Air: M = 36.8, SD = 25.3; EANx30: M = 24.8, SD = 16.1) when breathing both air and EANx30. However, ratings were significantly lower when breathing EANx30 compared to air when in the deep water. DISCUSSION: It was concluded EANx30 does not reduce narcotic impairment over air. Additionally, divers were able to make a correct global self-assessment they were impaired by narcosis, but were unable to make a finer assessment, leading them to erroneously believe that EANx30 was less narcotic than air.

Alzheimer's disease: a gas model. The NADPH oxidase-Nitric Oxide system as an antibubble biomachinery.

Alzheimer's disease (AD) is a neurodegenerative disease of unknown origin. The pathological lesions that define AD would be linked to the insidious accumulation of nitrogen, having invaded the brain interstitial fluid (ISF) from the blood via the physiological cycling pool of vascular glucose transporters (GLUT-1). According to this hypothesis, the nitrogen nanobubbles, being chemically inert and actually indestructible for human beings, can not escape from the ISF anymore. They would exert a huge and deleterious pressure against cellular components, especially in microglia and in astrocytes. They could enhance the existing cell oxygen anisotropy, which might enhance the natural bubble nucleation of O2-2O2 in cells or in mitochondria. Indeed, with the help of a new symbolic representation for gas nuclei in chemical reactions, the NADPH oxidase-NO system is identified for the first time, as an antibubble biomachinery, able to break O2-2O2 bubbles up as it releases superoxide O2-. Superoxide is considered as a quantum bubble, which collapses through the reactivity of the gaseous NO radical. Their combination in soluble peroxinitrite provides the change from one state of matter to another, avoiding any risk of a bubble enlargement, and finally avoiding the risk of enzyme crowding or of a bulk pressure variation. However, a bubble is expected to entrap Nitric Oxide (NO), which leads theoretically to a decrease in its bioavailability, and is expected to trigger a guanylyl-cyclase-mediated inflammatory cascade, that could explain the inflammation in AD. In vitro, any increase in the hydrostatic pressure has already been linked to the microtubule disorganization. The amyloid deposits, also known as senile plaques, would behave as a sponge toward ISF nitrogen; Aß is considered as a foam-stabilizing agent. By taking the shape of cerebral amyloid angiopathy, the amyloid could confine the nitrogen leak from the blood, and progressively insulate the Blood-Brain Barrier against the pollutant. All these theoretical features finally lead to the death of the neurons. The comprehensive statement of the theoretical pro-inflammatory action of inert gases is a real upheaval for the whole medicine.

Physiological and behavioral responses of poultry exposed to gas-filled high expansion foam.

Disease control measures require poultry to be killed on farms to minimize the risk of disease being transmitted to other poultry and, in some cases, to protect public health. We assessed the welfare implications for poultry of the use of high-expansion gas-filled foam as a potentially humane, emergency killing method. In laboratory trials, broiler chickens, adult laying hens, ducks, and turkeys were exposed to air-, N2-, or CO2-filled high expansion foam (expansion ratio 300:1) under standardized conditions. Birds were equipped with sensors to measure cardiac and brain activity, and measurements of oxygen concentration in the foam were carried out. Initial behavioral responses to foam were not pronounced but included headshakes and brief bouts of wing flapping. Both N2- and CO2-filled foam rapidly induced ataxia/loss of posture and vigorous wing flapping in all species, characteristic of anoxic death. Immersion in air-filled, high expansion foam had little effect on physiology or behavior. Physiological responses to both N2- and CO2-filled foam were characterized by a pronounced bradyarrythymia and a series of consistent changes in the appearance of the electroencephalogram. These were used to determine an unequivocal time to loss of consciousness in relation to submersion. Mean time to loss of consciousness was 30 s in hens and 18 s in broilers exposed to N2-filled foam, and 16 s in broilers, 1 s in ducks, and 15 s in turkeys exposed to CO2-filled foam. Euthanasia achieved with anoxic foam was particularly rapid, which is explained by the very low oxygen concentrations (below 1%) inside the foam. Physiological observations and postmortem examination showed that the mode of action of high expansion, gas-filled foam is anoxia, not occlusion of the airway. These trials provide proof-of-principle that submersion in gas-filled, high expansion foam provides a rapid and highly effective method of euthanasia, which may have potential to provide humane emergency killing or routine depopulation.