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Steve F. Perry - One of the best experts on this subject based on the ideXlab platform.
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Cardio-respiratory effects of Chloramine-T exposure in rainbow trout
Experimental Biology Online, 1999Co-Authors: Mark D. Powell, Steve F. PerryAbstract:In order to establish whether the blood gas respiratory disturbances noted with exposure to Chloramine-T are due to differences in the rates of uptake of O_2 and excretion of CO_2 or gill blood flow, adult rainbow trout ( Oncorhynchus mykiss ) were fitted with dorsal aorta and bulbus arteriosus catheters to facilitate blood pressure recordings, an ultrasonic blood flow probe and opercular impedance electrodes. Fish received either a 45-min static exposure to 9 mg l^−1 Chloramine-T or tap water (control) and continuous recordings of blood pressure, and ventilation frequency and amplitude were made. Pre- and post-exposure arterial and venous blood samples were taken and analyzed for O_2 and CO_2 content, hemoglobin concentration and hematocrit. Chloramine-T exposure had no effect on any of the continuously recorded parameters. However, individual measurements (made immediately prior to and following exposure) of cardiac output and O_2 uptake rates increased significantly following exposure to Chloramine-T compared to before exposure. CO_2 excretion rates were unaffected by Chloramine-T exposure. Calculation of the perfusion convection requirement showed a significant increase for CO_2 but not for O_2. It was concluded that increases in O_2 uptake resulted from increased cardiac output but that CO_2 excretion, a diffusion-limited process, was not increased due to additional diffusive limitations caused by the irritant effect of Chloramine-T.
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Response of rainbow trout (Oncorhynchus mykiss) to a graded hypoxia following repeated intermittent exposure to Chloramine-T
Aquaculture, 1998Co-Authors: Mark D. Powell, François Haman, Glenda M. Wright, Steve F. PerryAbstract:Abstract The physiological effects of repeated exposure to 9 mg l −1 Chloramine-T, a common aquaculture disinfectant for rainbow trout, were examined using a graded hypoxic challenge. Using an extracorporeal circulation, continuous measurements of blood PO 2 , PCO 2 and pH were made and correlated with decreasing water PO 2 . Ventilation amplitude and frequency were also monitored. Following the graded hypoxic challenge, the gills were removed and processed for microscopy for morphometric measurements and the determination of the number of branchial mucous cells. Fish treated with Chloramine-T exhibited a higher arterial PO 2 during hypoxia between 10.1 and 11.2 kPa when compared with untreated controls; there were no differences in arterial PCO 2 or pH between the two groups. Chloramine-T-treated fish had an elevated pre-hypoxic ventilation frequency as compared with the controls. However, under the graded hypoxia, control fish elevated their ventilation frequency, whereas Chloramine-T-treated fish did not. Both Chloramine-T-treated and control fish increased their ventilation amplitude during the graded hypoxia and there were no differences between control and Chloramine-T-treated fish. The fish treated with Chloramine-T had a reduced thickness of the gill epithelial blood-to-water diffusion barrier but higher numbers of mucous cells as compared with controls. We suggest that although there was a mucous cell hyperplasia in response to repeated Chloramine-T exposure, the thinning of the lamellar epithelium was sufficient to offset any diffusive limitations, thus ensuring that gas exchange was not adversely affected.
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Acid–base and ionic fluxes in rainbow trout (Oncorhynchus mykiss) during exposure to Chloramine-T
Aquatic Toxicology, 1998Co-Authors: Mark D. Powell, Steve F. PerryAbstract:The effects of Chloramine-T and its degradation products, sodium hypochlorite (NaOCl) and para-toluenesulphonamide (pTSA), on whole body acid–base and branchial and renal ion (Na+and Cl−) fluxes were examined in rainbow trout (Oncorhynchus mykiss). Exposure to Chloramine-T (3.5 h, 18 mg l−1) resulted in increases in plasma total CO2 but no coincident rise in PaCO2 or reduction in blood pH. Exposure of fish to 2, 9 or 18 mg l−1 Chloramine-T (3.5 h duration) resulted in a reduction in net acid uptake suggesting the development of a metabolic alkalosis. Exposure to the Chloramine-T breakdown product pTSA (dissolved in DMSO) resulted in increased net acid uptake (decreased acid excretion) suggesting a metabolic acidosis. Whole body ion fluxes demonstrated increases in the losses of both Na+and Cl− with Chloramine-T, NaOCl and pTSA. However, the effect of DMSO alone could not be isolated. Confirmatory studies using fish in which the urinary bladder (to allow collection of urine) and dorsal aorta (to allow injection of [14C]polyethylene glycol 4000 ([14C]PEG), an extracellular fluid marker) were catheterised, revealed that changes in whole body ion fluxes during Chloramine-T exposure could not be explained by increased renal efflux through urine flow, glomerular filtration or renal clearance. Branchial effluxes of [14C]PEG were not significantly affected by Chloramine-T exposure suggesting that the changes in whole body ionic fluxes were caused by transcellular rather than paracellular processes.
Mark D. Powell - One of the best experts on this subject based on the ideXlab platform.
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Influence of Oxygen on the Toxicity of Chloramine-T to Atlantic Salmon Smolts in Freshwater and Seawater
Journal of Aquatic Animal Health, 2004Co-Authors: Mark D. Powell, James O. HarrisAbstract:Abstract Chloramine-T is a widely used disinfectant for the treatment of gill diseases of fish in freshwater, and more recently attention has turned to its use in seawater. However, despite the wide use of Chloramine-T, few studies have examined its acute toxicity to fish. In this study we examined the acute (within 12 h) toxicity of freshwater- and seawater-acclimated Atlantic salmon Salmo salar smolts under aerated (100% air saturation with O2) and oxygen supersaturation conditions (200% air saturation with O2). Chloramine-T was more acutely toxic to salmon in seawater than to those in freshwater, and oxygen supersaturation enhanced the toxicity in both sea- and freshwater. In aerated freshwater the median lethal times (LT50s) for Chloramine-T concentrations of 50 and 25 mg/L were 166.8 and 474.3 min, respectively; in aerated seawater they were 119.1 and 297.3 min, respectively. However, in freshwater at 200% air saturation with oxygen, the 50 and 25 mg/L LT50s were 133.6 and 190.9 min, respectively; in...
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Cardio-respiratory effects of Chloramine-T exposure in rainbow trout
Experimental Biology Online, 1999Co-Authors: Mark D. Powell, Steve F. PerryAbstract:In order to establish whether the blood gas respiratory disturbances noted with exposure to Chloramine-T are due to differences in the rates of uptake of O_2 and excretion of CO_2 or gill blood flow, adult rainbow trout ( Oncorhynchus mykiss ) were fitted with dorsal aorta and bulbus arteriosus catheters to facilitate blood pressure recordings, an ultrasonic blood flow probe and opercular impedance electrodes. Fish received either a 45-min static exposure to 9 mg l^−1 Chloramine-T or tap water (control) and continuous recordings of blood pressure, and ventilation frequency and amplitude were made. Pre- and post-exposure arterial and venous blood samples were taken and analyzed for O_2 and CO_2 content, hemoglobin concentration and hematocrit. Chloramine-T exposure had no effect on any of the continuously recorded parameters. However, individual measurements (made immediately prior to and following exposure) of cardiac output and O_2 uptake rates increased significantly following exposure to Chloramine-T compared to before exposure. CO_2 excretion rates were unaffected by Chloramine-T exposure. Calculation of the perfusion convection requirement showed a significant increase for CO_2 but not for O_2. It was concluded that increases in O_2 uptake resulted from increased cardiac output but that CO_2 excretion, a diffusion-limited process, was not increased due to additional diffusive limitations caused by the irritant effect of Chloramine-T.
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Response of rainbow trout (Oncorhynchus mykiss) to a graded hypoxia following repeated intermittent exposure to Chloramine-T
Aquaculture, 1998Co-Authors: Mark D. Powell, François Haman, Glenda M. Wright, Steve F. PerryAbstract:Abstract The physiological effects of repeated exposure to 9 mg l −1 Chloramine-T, a common aquaculture disinfectant for rainbow trout, were examined using a graded hypoxic challenge. Using an extracorporeal circulation, continuous measurements of blood PO 2 , PCO 2 and pH were made and correlated with decreasing water PO 2 . Ventilation amplitude and frequency were also monitored. Following the graded hypoxic challenge, the gills were removed and processed for microscopy for morphometric measurements and the determination of the number of branchial mucous cells. Fish treated with Chloramine-T exhibited a higher arterial PO 2 during hypoxia between 10.1 and 11.2 kPa when compared with untreated controls; there were no differences in arterial PCO 2 or pH between the two groups. Chloramine-T-treated fish had an elevated pre-hypoxic ventilation frequency as compared with the controls. However, under the graded hypoxia, control fish elevated their ventilation frequency, whereas Chloramine-T-treated fish did not. Both Chloramine-T-treated and control fish increased their ventilation amplitude during the graded hypoxia and there were no differences between control and Chloramine-T-treated fish. The fish treated with Chloramine-T had a reduced thickness of the gill epithelial blood-to-water diffusion barrier but higher numbers of mucous cells as compared with controls. We suggest that although there was a mucous cell hyperplasia in response to repeated Chloramine-T exposure, the thinning of the lamellar epithelium was sufficient to offset any diffusive limitations, thus ensuring that gas exchange was not adversely affected.
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Acid–base and ionic fluxes in rainbow trout (Oncorhynchus mykiss) during exposure to Chloramine-T
Aquatic Toxicology, 1998Co-Authors: Mark D. Powell, Steve F. PerryAbstract:The effects of Chloramine-T and its degradation products, sodium hypochlorite (NaOCl) and para-toluenesulphonamide (pTSA), on whole body acid–base and branchial and renal ion (Na+and Cl−) fluxes were examined in rainbow trout (Oncorhynchus mykiss). Exposure to Chloramine-T (3.5 h, 18 mg l−1) resulted in increases in plasma total CO2 but no coincident rise in PaCO2 or reduction in blood pH. Exposure of fish to 2, 9 or 18 mg l−1 Chloramine-T (3.5 h duration) resulted in a reduction in net acid uptake suggesting the development of a metabolic alkalosis. Exposure to the Chloramine-T breakdown product pTSA (dissolved in DMSO) resulted in increased net acid uptake (decreased acid excretion) suggesting a metabolic acidosis. Whole body ion fluxes demonstrated increases in the losses of both Na+and Cl− with Chloramine-T, NaOCl and pTSA. However, the effect of DMSO alone could not be isolated. Confirmatory studies using fish in which the urinary bladder (to allow collection of urine) and dorsal aorta (to allow injection of [14C]polyethylene glycol 4000 ([14C]PEG), an extracellular fluid marker) were catheterised, revealed that changes in whole body ion fluxes during Chloramine-T exposure could not be explained by increased renal efflux through urine flow, glomerular filtration or renal clearance. Branchial effluxes of [14C]PEG were not significantly affected by Chloramine-T exposure suggesting that the changes in whole body ionic fluxes were caused by transcellular rather than paracellular processes.
P S Burge - One of the best experts on this subject based on the ideXlab platform.
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Occupational asthma caused by chloramines in indoor swimming-pool air
European Respiratory Journal, 2002Co-Authors: K. M. Thickett, J. S. Mccoach, J. M. Gerber, Steven Sadhra, P S BurgeAbstract:The first series of three workers who developed occupational asthma following exposure to airborne chloramines in indoor chlorinated swimming pools is reported. Health problems of swimmers in indoor pools have traditionally been attributed to the chlorine in the water. Chlorine reacts with bodily proteins to form chloramines; the most volatile and prevalent in the air above swimming pools is nitrogen trichloride. Two lifeguards and one swimming teacher with symptoms suggestive of occupational asthma kept 2-hourly measurements of peak expiratory flow at home and at work, analysed using the occupational asthma system (OASYS) plotter, and/or had specific bronchial challenge testing to nitrogen trichloride, or a workplace challenge. Air measurement in one of the pools showed the nitrogen trichloride levels to be 0.1-0.57 mg x m(-3), which was similar to other studies. Two workers had peak expiratory flow measurements showing occupational asthma (OASYS-2 scores 2.88 and 3.8), both had a positive specific challenge to nitrogen trichloride at 0.5 mg x m(-3) with negative challenges to chlorine released from sodium hypochlorite. The third worker had a positive workplace challenge. Swimming-pool asthma due to airborne nitrogen trichloride can occur in workers who do not enter the water because of this chloramine. The air above indoor swimming pools therefore needs to be assessed and managed as carefully as the water.
Mitsuo Komatsu - One of the best experts on this subject based on the ideXlab platform.
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Electrophilic cyclization of N-alkenylamides using a Chloramine-T/I2 system
Tetrahedron, 2006Co-Authors: Yoshinobu Morino, Mitsuo Komatsu, Ikumasa Hidaka, Yoji Oderaotoshi, Satoshi MinakataAbstract:Abstract A new protocol for the cyclization of N-alkenylamides using Chloramine-T and iodine is described. When N-alkenylsulfonamides are treated with Chloramine-T and iodine, three- to six-membered N-heterocycles are obtained with complete stereoselectivity. The method is compatible with the cyclization of the allylbenzamide or allylbenzthioamide to afford an oxazoline or thiazoline derivative, respectively. Mechanistic studies indicate that the Chloramine-T/I2 system functions as an effective iodonium species.
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Development of New Synthetic Methods of Heterocycles Using Chloramine-T as a Nitrogen Source
Journal of Synthetic Organic Chemistry Japan, 2003Co-Authors: Satoshi Minakata, Mitsuo KomatsuAbstract:We have exploited the novel strategies for construction of N-heterocycles using Chloramine-T as an N 1 unit. Copper (I) chloride or iodine was found to be a good catalyst for aziridination of various alkenes with Chloramine-T. The combination of Chloramine-T and silver nitrate directly led to not only aziridines from alkenes including α, β-unsaturated carbonyl compounds but also bicyclic pyrrolidines from 1, 6-dienes. The synthesis of pyrrolidine derivatives was achieved efficiently and stereoselectively from alkenyl iodides and Chloramine-T, in which the iodo group of the substrates has multiple functions to perform the cyclization. Furthermore, organic-solvent-free aziridination of alkenes was developed by utilizing Chloramine-T-I2 system under phase-transfer catalyst conditions or under the reaction media of silica and water.
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nitrogen atom transfer to alkenes utilizing chloramine t as a nitrogen source
Tetrahedron Letters, 1998Co-Authors: Takashi Ando, Satoshi Minakata, Ilhyong Ryu, Mitsuo KomatsuAbstract:Abstract Aziridination of alkenes proceeds successfully using Chloramine-T (N-chloro-N-sodio-p-toluenesulfonamide). When anhydrous Chloramine-T was added to an acetonitrile solution of alkenes in the presence of various CuCl catalysts and MS-5A, the corresponding aziridines were obtained in moderate to good yields.
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Iodine-catalyzed aziridination of alkenes using Chloramine-T as a nitrogen source
Tetrahedron, 1998Co-Authors: Takashi Ando, Satoshi Minakata, Daisuke Kano, Ilhyong Ryu, Mitsuo KomatsuAbstract:Abstract Iodine was found to be an efficient catalyst for the aziridination of alkenes utilizing Chloramine-T (N-chloro-N-sodio-p-toluenesulfonamide) as a nitrogen source. For example, when two equivalents of styrene were added to Chloramine-T in the presence of a catalytic amount of iodine in a 1 : 1 solvent mixture of acetonitrile and neutral buffer, the corresponding aziridine 1 was obtained in 91% yield. The reaction could be applied to other acyclic and cyclic alkenes such as 1-octene and cyclohexene. The aziridination of p-substituted styrene derivatives 2–5 with Chloramine-T showed that electron-rich alkenes reacted faster than electron-poor ones. Several Chloramine-T analogs were also examined and were found to give the corresponding aziridines 8–10 in only moderate yields.
Keiko Wada - One of the best experts on this subject based on the ideXlab platform.
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Investigation of oxidative degradation of polyamide reverse osmosis membranes by monochloramine solutions
Journal of Membrane Science, 2006Co-Authors: Maurício Kipper Da Silva, Isabel Cristina Tessaro, Keiko WadaAbstract:The aim of this work was to study the effect of monochloramine solutions on polyamide membranes in the reverse osmosis process. Chloramines could represent a good alternative to replace free chlorine in the water disinfection process, resulting in higher water quality and minor environmental impact. The experiments were carried out in a bench-scale reverse osmosis unit using highly concentrated monochloramine solutions and two different commercial reverse osmosis polyamide membranes. The monochloramine solutions were prepared with an excess of ammonium chloride and commercial sodium hypochlorite in order to assure predominantly monochloramine formation with total consumption of free chlorine. Besides the iron that always was present, experiments were also conducted by adding aluminum to the chloramine solution, to determine whether this substance can act as a catalyst in the membrane degradation process. The membrane performance was evaluated before and after exposition to the oxidative solutions by using water and 2000 ppm concentrated NaCl solutions. It has been verified that the permeate flux increases continuously with the exposition time of the membranes to the monochloramine solutions. The salt passage also presented some changes, however monochloramines seems to be less aggressive than free chlorine and chlorine dioxide under similar operating conditions. Further systematic studies are required to determine precisely the effect of iron or aluminum on the membrane degradation process.