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Braz. j. biol ; 82: e235927, 2022. tab, graf
Article in English | LILACS | ID: biblio-1249226


Abstract Glutamine synthetase (GS), encoded by glnA, catalyzes the conversion of L-glutamate and ammonium to L-glutamine. This ATP hydrolysis driven process is the main nitrogen assimilation pathway in the nitrogen-fixing bacterium Azospirillum brasilense. The A. brasilense strain HM053 has poor GS activity and leaks ammonium into the medium under nitrogen fixing conditions. In this work, the glnA genes of the wild type and HM053 strains were cloned into pET28a, sequenced and overexpressed in E. coli. The GS enzyme was purified by affinity chromatography and characterized. The GS of HM053 strain carries a P347L substitution, which results in low enzyme activity and rendered the enzyme insensitive to adenylylation by the adenilyltransferase GlnE.

Resumo A glutamina sintetase (GS), codificada por glnA, catalisa a conversão de L-glutamato e amônio em L-glutamina. Este processo dependente da hidrólise de ATP é a principal via de assimilação de nitrogênio na bactéria fixadora de nitrogênio Azospirillum brasilense. A estirpe HM053 de A. brasilense possui baixa atividade GS e excreta amônio no meio sob condições de fixação de nitrogênio. Neste trabalho, os genes glnA das estirpes do tipo selvagem e HM053 foram clonados em pET28a, sequenciados e superexpressos em E. coli. A enzima GS foi purificada por cromatografia de afinidade e caracterizada. A GS da estirpe HM053 possui uma substituição P347L que resulta em baixa atividade enzimática e torna a enzima insensível à adenililação pela adenililtransferase GlnE.

Bacterial Proteins/genetics , Azospirillum brasilense/enzymology , Azospirillum brasilense/genetics , Ammonium Compounds , Glutamate-Ammonia Ligase/genetics , Escherichia coli/genetics
Braz. j. biol ; 82: e233567, 2022. tab, graf
Article in English | LILACS | ID: biblio-1249220


Abstract 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.

Resumo 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.

Ammonium Compounds , Nitrogen , Plant Roots/chemistry , Salt Stress , Homeostasis , Italy , Nitrates
Arq. Inst. Biol ; 88: e00502019, 2021. ilus, graf
Article in English | LILACS, VETINDEX | ID: biblio-1146668


The present study assessed the efficacy of formulated biocontrol agents and nitrogen fertilization on southern blight control. Antagonism test in vitro was performed to assess the inhibitory activity of Bacillus methylotrophicus and Trichoderma asperellum against the growth of Sclerotium rolfsii. Tomato seedlings were transplanted into the substrate added with ammonium nitrate doses and inoculated with the formulated biocontrol agents Ônix (B. methylotrophicus) or Quality (T. asperellum). Subsequently, seedlings were inoculated with S. rolfsii. Plant mortality, shoot and root weight were assessed 11 days after the last inoculation. Agents had effective inhibitory activity against S. rolfsii; thus, they could reduce southern blight severity when combined with ammonium nitrate. However, plant mortality was not reduced by them.(AU)

Bacillus , Trichoderma , Lycopersicon esculentum , In Vitro Techniques , Pest Control, Biological , Ammonium Compounds
Rev. chil. obstet. ginecol. (En línea) ; 85(supl.1): S67-S74, set. 2020. tab, graf
Article in Spanish | LILACS | ID: biblio-1138650


INTRODUCCIÓN: La reciente pandemia por SARS-CoV-2 (COVID-19) ha hecho resurgir preocupación sobre la exposición inadvertida del equipo quirúrgico a agentes infecciosos transmisibles por vía aérea durante el acto quirúrgico. El objetivo de este trabajo es describir la confección de un sistema de filtrado simple y de bajo costo que permite reducir el riesgo de exposición al virus, particularmente en el proceso de aspiración, recambio y remoción del neumoperitoneo en cirugía laparoscópica. MATERIALES Y MÉTODO: Se diseñó e implementó un circuito cerrado de evacuación y de filtrado del neumoperitoneo en cirugías ginecológicas laparoscópicas en un centro de salud terciario. El circuito incluye un filtro HEPA (High Efficiency Particulate Air) y una trampa de vacío que contiene una solución de inactivación en base a amonio cuaternario o hipoclorito de sodio. RESULTADOS: Desde su implementación se han realizado 17 cirugías laparoscópicas ginecológicas por diversas patologías. Dos de ellas fueron en pacientes Covid-19 (+). A la fecha no se han reportado contagios en el equipo médico que participó en la cirugía. CONCLUSIONES: Es posible implementar un sistema de evacuación del neumoperitoneo en cirugía laparoscópica presumiblemente eficaz en minimizar el riesgo de exposición al virus SARS-COV-2 (Covid-19). Su bajo costo lo hace especialmente recomendable en países en vías de desarrollo.

INTRODUCTION: The recent SARS-CoV-2 (COVID-19) pandemics has raised concern on the incidental exposition of health team to air transmissible infectious agents during surgeries. The main goal of this work is to communicate a simple and low-cost filtering system allowing to reduce the risk of contagion related to the virus, associated with pneumoperitoneum removal during surgical laparoscopy. METHODS: A closed circuit of gas removal and filtering was developed and implemented in laparoscopic gynecologic procedures at a tertiary teaching hospital. The circuit included an HEPA (High Efficiency Particulate Air) filter and a vacuum trap containing an inactivating solution based on quaternary ammonium or sodium hypochlorite. RESULTS: Since its introduction, seventeen laparoscopic surgeries have been carried out for different gynecologic pathologies. Two of them in Covid (+) cases. To date, no contagion has been reported among health teammates participating in these surgeries. CONCLUSIONS: It is possible to implement a pneumoperitoneum evacuation system in laparoscopic surgery presumably effective in minimizing the risk of exposure to the SARS-COV-2 virus (Covid-19). Its low cost makes it especially recommended in developing countries.

Humans , Female , Pneumonia, Viral/prevention & control , Gynecologic Surgical Procedures/methods , Coronavirus Infections/prevention & control , Pandemics/prevention & control , Pneumonia, Viral/transmission , Pneumoperitoneum , Security Measures , Sodium Hypochlorite , Laparoscopy/methods , Infectious Disease Transmission, Patient-to-Professional/prevention & control , Coronavirus Infections/transmission , Low Cost Technology , Ammonium Compounds , Betacoronavirus
Electron. j. biotechnol ; 37: 25-33, Jan. 2019. tab, graf, ilus
Article in English | LILACS | ID: biblio-1051225


Background: Ammonium stress is a prime limiting phenomenon that occurs during methane formation from poultry manure. It is caused by elevated ammonium nitrogen concentrations that result from substrate decomposition. The amounts of methane formed depend on the activity of methanogenic microbes. Results: During the research reported in this paper, the response of a mesophilic consortium inhabiting a biogas reactor to rising load of poultry manure was investigated. The taxonomic composition of bacterial population was mostly typical, however syntrophic bacteria were not detected. This absence resulted in limitation of succession of some methanogenic microorganisms, especially obligate hydrogenotrophs. The methanogenic activity of the consortium was totally dependent on the activity of Methanosaeta. Inhibition of methanoganesis was noticed at ammonium nitrogen concentration of 3.68 g/L, total cessation occurred at 5.45 g/L. Significant amounts of acetic acid in the fermentation pulp accompanied the inhibition. Conclusions: The effectiveness of the consortium was totally dependent on the metabolic activity of the acetoclastic Methanoseata genus and lack of SAOB did not allow hydrogenotrophic methanogens to propagate and lead to cessation of biogas production at an elevated ammonium concentration at which acetoclastic methanogens were inhibited.

Methanosarcinaceae/metabolism , Biofuels , Microbiota , Anaerobiosis , Poultry , Stress, Physiological , Polymerase Chain Reaction , DNA Fingerprinting , Chromatography, High Pressure Liquid , Archaea/metabolism , Biodiversity , Fermentation , Microbial Consortia , Ammonium Compounds , Manure , Methane , Nitrogen
Rev. argent. microbiol ; 51(4): 371-380, dic. 2019. graf
Article in English | LILACS | ID: biblio-1057403


Abstract Cattle manure composting was performed in an aerated vessel. Community structure and diversity of ammonia-oxidizing bacteria (AOB) and ammonia-oxidizing archaea (AOA) were investigated using polymerase chain reaction and denaturing gradient gel electrophoresis (PCR-DGGE) techniques targeting the ammonia monooxygenase alpha subunit (amoA) gene and the correlation between AOB and AOA communities and environmental factors was explored. Thirteen (13) AOB sequences were obtained, which were closely related to Nitrosomonas spp., Nitrosomonas eutropha, and Nitrosospira spp. and uncultured bacteria, among which Nitrosomonas spp. were predominant. Excessively high temperature and high ammonium concentration were not favorable for AOB growth. Five AOA sequences, belonging to Candidatus Nitrososphaera gargensis and to an uncultured archaeon, were obtained. During composting, community diversity of AOB and AOA fluctuated, with AOA showing a higher Shannon-Wiener index. The AOB community changed more dramatically in the mesophilic stage and the early thermophilic stage, whereas the most obvious AOA community succession occurred in the late thermophilic stage, the cooling stage and the maturity stage. Water content, total nitrogen (TN) and ammonium concentration were more relevant to the AOB community structure, while higher correlations were observed between ammonia, nitrate and TN and the AOA community. AOB community diversity was negatively correlated with pH (r = -0.938, p < 0.01) and water content (r = -0.765, p < 0.05), while positively correlated with TN (r = 0.894, p < 0.01). AOA community diversity was negatively correlated with ammonium concentration (r = -0.901, p < 0.01). Ammonium concentration played an important role in the succession of AOB and AOA communities during composting.

Resumen Se llevó a cabo un compostaje de estiércol de ganado en un recipiente aireado. Se investigó la estructura de la comunidad y la diversidad de bacterias oxidantes del amoníaco (AOB) y las arqueas oxidantes del amoníaco (AOA) mediante el uso de las técnicas de reacción en cadena de la polimerasa y la electroforesis en gel con gradiente de desnaturalización (PCR-DGGE) dirigidas al gen de la subunidad alfa de la amonio monooxigenasa (amoA), y se exploró la correlación entre las comunidades AOB, AOA y los factores ambientales. Se obtuvieron 13 secuencias de AOB, las cuales se relacionaron estrechamente con Nitrosomonas spp., Nitrosomonas eutropha y Nitrosospira spp., y bacterias no cultivadas, entre las cuales fueron predominantes las Nitrosomonas spp. La temperatura excesivamente alta y la concentración de amonio elevada no fueron favorables para el crecimiento de las AOB. Se obtuvieron 5 secuencias de AOA, pertenecientes a Candidatus Nitrososphaera gargensis y un Archaeon no cultivado. Durante el compostaje, la diversidad de AOB y AOA fluctuó y las AOA mostraron un índice de Shannon-Wiener más alto. La comunidad de AOB cambió significativamente en la etapa mesofílica y la etapa termofílica temprana, mientras que la sucesión más obvia de la comunidad AOA ocurrió en la etapa termofílica tardía y las etapas de enfriamiento y de maduración. El contenido de agua, el nitrógeno total (TN) y la concentración de amonio fueron más relevantes para la estructura de la comunidad AOB, mientras que se observaron correlaciones mayores entre amoníaco, nitrato y TN, y la comunidad AOA. La diversidad de la comunidad AOB se correlacionó negativamente con el pH (r= -0,938; p < 0,01) y el contenido de agua (r = -0,765; p < 0,05), mientras que se relacionó positivamente con TN (r = 0,894; p < 0,01). La diversidad de la comunidad AOA se correlacionó negativamente con la concentración de amonio (r = -0,901; p < 0,01). La concentración de amonio desempenó un papel importante en la sucesión de las comunidades AOB y AOA durante el compostaje.

Bacteria/growth & development , Archaea/growth & development , Nitrification , Ammonium Compounds/analysis , Polymerase Chain Reaction/methods , Oxidants/chemistry , Electrophoresis/methods , Manure/microbiology
Braz. j. biol ; 79(4): 646-650, Nov. 2019. tab
Article in English | LILACS | ID: biblio-1001475


Abstract Deionized ammonium (NH3) acute toxicity (LC50-96h) in Patagonian blenny juveniles (Eleginops maclovinus) was assessed. Concentrations of deionized ammonium in salt water were prepared by using 24.09 ± 2.1 g ammonium chloride (NH4Cl). Fish were exposed in triplicates to different ammonium concentrations: 0.05; 0.094; 0.175; 0.325 and 0.605 mg NH3 L-1. Additionally, a control group was included. Experimental fish were kept at a photoperiod of 16:8h. Average temperatures were 16.24 ± 1.40 °C. Oxygen concentration was 7.16 ± 0.40 mg L -1. Water pH was 7.89 ± 0.2. LC50-96 h, was estimated by using Probit statistical method (95% intervals) using EPA software (1993). Juveniles of E. maclovinus showed a LC50-96h of 0.413mg NH3 L-1 value, different from most marine species. This study presents the first record of ammonium toxicity in marine species of Chile.

Resumo A toxicidade aguda (LC50-96h) de amônia deionizada (NH3 ) em Babosas-da-Patagônia (Eleginops maclovinus) juvenis foi avaliada. As concentrações de sal de amônia deionizada em água foram preparados com 24,09 ± 2,1 g de cloreto de amônio (NH4Cl). Os peixes foram expostos em triplicata a diferentes concentrações de amônia: 0,05; 0,094; 0,175; 0,325 e 0,605 mg L-1 de NH3. Além disso, um grupo de controle foi incluído. Peixes experimentais foram mantidos em fotoperíodo de 16: 8h. As temperaturas médias foram 16,24 + 1,40 °C. A concentração de oxigênio foi 16.24 +1.40°C mg L-1 . O pH da água foi de 7,89 + 0,2. h LC50-96h, foi estimada usando o método estatístico de Probit (intervalos de 95%) usando o software EPA (1993). E. maclovinus juvenis apresentaram uma LC 50-96h de 0.413mg NH3 L-1 valor diferente da maioria das espécies marinhas. Este estudo apresenta o primeiro registro de toxicidade amónio em espécies marinhas do Chile.

Animals , Perciformes/growth & development , Perciformes/physiology , Ammonium Compounds/toxicity , Fish Diseases/chemically induced , Temperature , Water Pollutants, Chemical/toxicity , Chile
Article in English | WPRIM | ID: wpr-764033


The present study aimed at evaluating serum immunoglobulin G (IgG) avidity to Porphyromonas gingivalis in elderly patients with mild and severe chronic periodontitis. The avidity of antibodies against P. gingivalis present in the sera of 18 patients with mild chronic periodontitis and 18 patients with severe chronic periodontitis was evaluated using an ammonium thiocyanate-dissociated enzyme-linked immunosorbent assay (ELISA). The results showed that the mean absorbance value in serum IgG antibody titers was significantly higher in the severe chronic periodontitis group than in the mild chronic periodontitis group (198 ± 35 ELISA unit [EU] vs. 142 ± 32 EU, p < 0.01). However, there was no significant difference between the two groups in antibody avidity (65 ± 57 EU vs. 54 ± 27 EU). These findings suggest that humoral immune responses to P. gingivalis between mild and severe chronic periodontitis in elderly patients are characterized by the differences in the quantity rather than the quality of the antibodies.

Aged , Ammonium Compounds , Antibodies , Antibody Affinity , Chronic Periodontitis , Enzyme-Linked Immunosorbent Assay , Geriatrics , Humans , Immunity, Humoral , Immunoglobulin G , Immunoglobulins , Porphyromonas gingivalis , Porphyromonas
Article in English | WPRIM | ID: wpr-742424


Apixaban, an inhibitor of direct factor Xa, is used for the treatment of venous thromboembolic events or prevention of stroke. Unlike many other anticoagulant agents, it does not need periodic monitoring. However, monitoring is still required to determine the risk of bleeding due to overdose or surgery. Usually, apixaban concentrations are indirectly quantified using an anti-factor Xa assay. However, this method has a relatively narrow analytical concentration range, poor selectivity, and requires an external calibrator. Therefore, the goal of current study was to establish an analytical method for determining plasma levels of apixaban using ultra performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS). To this end, apixaban was separated using 2.5 mM ammonium formate (pH 3.0) (A) and 100% methanol containing 0.1% formic acid (B) using the gradient method with a Thermo hypersil GOLD column. The mass detector condition was optimized using the electrospray ionization (ESI) positive mode for apixaban quantification. The developed method showed sufficient linearity (coefficient of determination [r² ≥ 0.997]) at calibration curve ranges. The percentage (%) changes in accuracy, precision, and all stability tests were within 15% of the nominal concentration. Apixaban concentration in plasma from healthy volunteers was quantified using the developed method. The mean maximum plasma concentration (C(max)) was 371.57 ng/mL, and the median time to achieve the C(max) (T(max)) was 4 h after administration of 10 mg apixaban alone. Although the results showed low extraction efficiency (~16%), the reproducibility (% change was within 15% of nominal concentration) was reliable. Therefore, the developed method could be used for clinical pharmacokinetic studies.

Ammonium Compounds , Anticoagulants , Calibration , Chromatography, Liquid , Factor Xa , Healthy Volunteers , Hemorrhage , Humans , Mass Spectrometry , Methanol , Methods , Plasma , Stroke , Tandem Mass Spectrometry
Article in Korean | WPRIM | ID: wpr-758417


PURPOSE: Owing to the increased agricultural use of the herbicide glufosinate ammonium (GLA), the incidence of GLA poisoning has recently increased. Therefore, we investigated the possible predictive factors associated with severe complications following GLA poisoning. METHODS: A retrospective analysis of medical records was conducted based on 76 patients who had visited our regional emergency medical center with GLA poisoning from 2006 to 2017. Severe complications were defined as respiratory failure requiring intubation, systolic blood pressure less than 90 mmHg, Glasgow Coma Scale (GCS) less than 8, and presence of seizure. RESULTS: Age, ingested amount and ingested amount per weight were significantly greater in the severe group (p<0.001). PSS grade 2 or higher was more common in the severe group (p<0.001), and In addition, the APACHE II score was significantly higher in the severe group (p<0.001), as were the SOFA scores (p=0.002). Serum ammonia levels were significantly higher in the severe group (p=0.007), while MDRD-GFR was smaller in the severe group (p=0.002). The spot urine protein levels were significantly higher in the severe group (p=0.005), as was the urine protein to creatinine ratio (p=0.001). Upon multivariate analysis, the amount ingested per weight and PSS grade 2 or higher were identified as significant predictors. CONCLUSION: Our study showed that MDRD-GFR was significantly lower in the severe group after GLA poisoning. PSS grade 2 or higher and ingested amount per weight may be useful to evaluate the severity of complications after GLA poisoning.

Ammonia , Ammonium Compounds , APACHE , Blood Pressure , Creatinine , Emergencies , Glasgow Coma Scale , Humans , Incidence , Intubation , Medical Records , Multivariate Analysis , Poisoning , Respiratory Insufficiency , Retrospective Studies , Seizures
Rev. biol. trop ; 66(3): 1101-1117, jul.-sep. 2018. tab, graf
Article in English | LILACS, SaludCR | ID: biblio-977370


Abstract Human pressures have placed many tropical estuaries in developing countries under increased levels of stress. The Caroni Swamp Ramsar Site, the largest mangrove swamp along the west coast of Trinidad, has been subjected to high levels of anthropogenic impacts including hydrological alteration and pollution from land-based sources since the 1920's. While most of these impacts have been well documented, limited information exists on the macrobenthic communities in the swamp. This study addresses the paucity of information. The macrobenthic fauna in the main waterways of Caroni Swamp was sampled at 12 locations using a Van Veen 0.025 m2 grab, once in the dry (April) and wet (August) season of 2015 with a total of 144 samples. The samples were sorted, counted and species were identified to the lowest possible taxonomic level. A total of 55 taxa were identified with polychaetes being the most abundant taxa. The ecological status of the macrobenthos was assessed using AZTI's Marine Biotic Index (AMBI) and the multivariate-AMBI (M-AMBI). Physicochemical parameters were measured with a YSI multiparameter metre. Chemical analyses were also conducted on nitrates, nitrites, ammonia and reactive phosphates using standard methods. Overall, AMBI characterised the Caroni Swamp as "slightly disturbed" with a macrobenthic community of "poor" ecological status according to M-AMBI. Generally, the quality of the environment improves from the dry season to the wet season. However, seasonal variations in AMBI and M-AMBI were found to be site specific as some showed improvement in ecological status and macrozoobenthos quality while others showed degradation from the dry season to the wet season. The stations to the North of the swamp showed improvement from the dry season to the wet season while the opposite was observed in the more Southern stations. One notable characteristic of the swamp was the high levels of pollutants, particularly ammonia, recorded in one of its major waterways, the Caroni River. This is in contrast to the other waterways within the swamp which experience much lower levels of pollutant input from land-based sources. The assessment of the Caroni Swamp using AMBI and M-AMBI may be useful for informing management strategies to conserve the wetland and improve environmental quality. Rev. Biol. Trop. 66(3): 1101-1117. Epub 2018 September 01.

Resumen Los estuarios tropicales de países en desarrollo han experimentado un aumento en los niveles de estrés debido a la presión humana. El sitio Ramsar pantano Caroní, el manglar más grande de la costa oeste de Trinidad, ha estado sujeto a altos niveles de impacto antropogénico, incluyendo alteraciones hidrológicas y contaminación de fuentes terrestres desde la década de 1920. Aunque la mayoría de estos impactos han sido bien documentados, existe información limitada sobre las comunidades macrobentónicas en el pantano. Este estudio aborda esta escasez de información. Se muestreó la fauna macrobentónica en el canal principal del pantano Caroní en 12 localidades utilizando una draga Van Veen de 0.025 m2, una vez durante la época seca (Abril) y la época lluviosa (Agosto) 2015, con un total de 144 muestras. Las muestras fueron ordenadas, contadas y las especies se identificaron al menor nivel taxonómico posible. Se identificaron un total de 55 taxa, siendo los poliquetos el taxa más abundante. El estatus ecológico del macrobentos se evaluó utilizando el Índice Marino Biótico de AZTI (AMBI) y el AMBI-multivariado (M-AMBI). Los parámetros fisicoquímicos se midieron con un multiparámetro YSI. Los análisis químicos también se realizaron para nitratos, nitritos, amonio y fostatos activos utilizando métodos estándar. En conjunto, el índice AMBI caracterizó el pantano Caroní como "levemente alterado" con una comunidad macrobentónica de categoría "pobre" de acuerdo al M-AMBI. Generalmente, la calidad de los ambientes incrementa desde la época seca hasta la época lluviosa. Sin embargo, las variaciones estacionales en los índices AMBI y M-AMBI fueron específicas a la localidad, mostrando algunas un incremento en el estatus ecológico y calidad del macrozoobentos, mientras que otros mostraron una degradación de la época seca a la época lluviosa. Las estaciones al norte del pantano mostraron una mejora de la época seca a la época lluviosa, mientras que se presentó lo contrario en las estaciones más al sur. Una característica notable del pantano fueron los altos niveles de contaminantes, particularmente amonio, registrado en uno de los canales principales del río Caroní. Esto contrasta con los otros canales del pantano que experimentan niveles menores de aporte de contaminantes de fuentes terrestres. La evaluación del pantano Caroní utilizando los índíces AMBI y M-AMBI puede ser una base útil de información para las estrategias de manejo y conservación del humedal y mejorar su calidad ambiental.

Polychaeta/growth & development , Seasons , Trinidad and Tobago , Benthic Fauna/analysis , Benthic Fauna/adverse effects , Benthic Flora/analysis , Wetlands , Ammonium Compounds/adverse effects , Human Activities , Water Pollutants/adverse effects , Environment
Article in English | WPRIM | ID: wpr-716967


BACKGROUND: Iodine deficiency (ID) has become a concern not only among pregnant women, but in women of childbearing age as well. In fact, a recent report suggested that women with moderate to severe ID may experience a significantly longer time to conceive. This study aimed to investigate iodine status in Filipino women of childbearing age. METHODS: The iodine status of 6,194 Filipino women aged 15 to 45 years old was assessed through urinary iodine analysis. A casual spot urine sample was collected from women in households participating in the eighth National Nutrition Survey conducted by the Food and Nutrition Research Institute. The sample was analyzed using ammonium persulfate digestion followed by the Sandell-Kolthoff colorimetric reaction. A median urinary iodine concentration (UIC) of less than 100 µg/L was used to define ID. RESULTS: The median UIC was 123 µg/L, indicative of adequate iodine nutrition; however, 21.5% of participants had a UIC below 50 µg/L. The median UIC of women who lived in urban areas (142 µg/L), belonged to the middle to richest class (>124 µg/L), had reached a college education (136 µg/L), and used iodized salt (15 ppm and above; 148 to 179 µg/L) reflected adequate iodine nutrition. ID was found to have been eliminated in the regions of Central Luzon, Eastern Visayas, Calabarzon, Mimaropa, and the National Capital, while mild ID was identified in Western Visayas, Southern and Western Mindanao, and in the Autonomous Region in Muslim Mindanao. CONCLUSION: Pockets of ID among women of childbearing age exist in the Philippines. Proper information through education and the use of adequately iodized salt are key measures for improving the iodine status of the studied population.

Academies and Institutes , Ammonium Compounds , Digestion , Education , Family Characteristics , Female , Humans , Iodine , Islam , Nutrition Surveys , Philippines , Pregnant Women
Yonsei Medical Journal ; : 633-642, 2018.
Article in English | WPRIM | ID: wpr-715899


PURPOSE: To investigate the effects of Helicobacter pylori (H. pylori)-CagA and the urease metabolite NH₄⁺ on mucin expression in AGS cells. MATERIALS AND METHODS: AGS cells were transfected with CagA and/or treated with different concentrations of NH₄⁺CL. Mucin gene and protein expression was assessed by qPCR and immunofluorescence assays, respectively. RESULTS: CagA significantly upregulated MUC5AC, MUC2, and MUC5B expression in AGS cells, but did not affect E-cadherin and MUC6 expression. MUC5AC, MUC6, and MUC2 expression in AGS cells increased with increasing NH₄⁺ concentrations until reaching a peak level at 15 mM. MUC5B mRNA expression in AGS cells (NH₄⁺ concentration of 15 mM) was significantly higher than that at 0, 5, and 10 mM NH₄⁺. No changes in E-cadherin expression in AGS cells treated with NH₄⁺ were noted, except at 20 mM. The expression of MUC5AC, MUC2, and MUC6 mRNA in CagA-transfected AGS cells at an NH₄⁺ concentration of 15 mM was significantly NH₄⁺ concentration, and was significantly higher compared to that in untreated cells. No significant change in the expression of E-cadherin mRNA in CagA-transfected AGS cells was observed. Immunofluorescence assays confirmed the observed changes. CONCLUSION: H. pylori may affect the expression of MUC5AC, MUC2, MUC5B, and MUC6 in AGS cells via CagA and/or NH₄⁺, but not E-cadherin.

Ammonium Chloride , Ammonium Compounds , Cadherins , Fluorescent Antibody Technique , Helicobacter pylori , Helicobacter , Mucins , RNA, Messenger , Stomach , Urease , Virulence
Article in English | WPRIM | ID: wpr-742411


This study aimed to develop a UPLC-MS/MS method for determining plasma levels of L-aspartic acid and L-asparagine and the activity of L-asparaginase. L-aspartic acid, L-asparagine, and L-aspartic acid-2,3,3-d3 were extracted from human plasma by protein precipitation with sulfosalicylic acid (30%, v/v). The plasma samples were analyzed using an Imtakt Intrada amino acid analysis column with 25 mM ammonium formate and 0.5% formic acid in acetonitrile as the mobile phase with step gradient method at a flow rate of 0.5 mL/min. The injection volume was 5 µL, and the total run time was 15 min. Inter- and intra-batch accuracies (%) ranged from 96.62–106.0% for L-aspartic acid and 89.85–104.8%, for L-asparagine, and the coefficient of variation (CV%) did not exceed 7%. The validation results for L-aspartic acid and L-asparagine satisfied the specified criterion, however, the results for L-asparaginase activity assay showed a borderline validity. This study could be a foundation for further development of therapeutic drug monitoring systems using UPLC-MS/MS.

Ammonium Compounds , Asparagine , Aspartic Acid , Drug Monitoring , Humans , Methods , Plasma
Article in English | WPRIM | ID: wpr-742404


An ultra performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) method was developed and validated for the quantification of donepezil in human plasma. Donepezil and donepezil-D4 were extracted from human plasma by liquid-liquid extraction using a mixture of hexane and ethyl acetate (70:30 v/v). The extracted samples were analyzed using a Thermo Hypersil Gold C18 column with 5% acetic acid in 20 mM ammonium acetate buffer (pH 3.3) and 100% acetonitrile as a mobile phase with the 60:40 (v:v) isocratic method, at a flow rate of 0.3 mL/min. The injection volume was 3 µL, and the total run time was 3 min. Inter- and intra-batch accuracies ranged from 98.0% to 110.0%, and the precision was below 8%. The developed method was successfully applied to the quantification of donepezil in human plasma. The mean (standard deviation) maximum concentration and the median (range) time to maximum concentration were 8.6 (2.0) ng/mL and 2.0 h (1.0~5.0 h), respectively, in healthy Koreans after oral administration of 5 mg donepezil.

Acetic Acid , Administration, Oral , Ammonium Compounds , Humans , Liquid-Liquid Extraction , Mass Spectrometry , Methods , Plasma
Article in English | WPRIM | ID: wpr-715160


PURPOSE: Glufosinate ammonium poisoning can cause seizures, even after a symptom-free period. This study was conducted to evaluate the relationship between serum neuron specific enolase (NSE) level and the occurrence of seizures in patients with acute glufosinate ammonium poisoning. METHODS: For this retrospective observational study, data from patients diagnosed with acute glufosinate ammonium poisoning were collected between January 2016 and June 2016. Serum NSE was measured within 2 hours of arrival at the emergency department. The patients were divided into a seizure group and a non-seizure group. RESULTS: The seizure group included eight of the 15 total patients (53.3%). The serum NSE level was significantly higher in the seizure group than in the non-seizure group (32.4±11.9 ng/mL vs. 19.5±5 ng/mL, p=0.019). The amount of glufosinate ingested and initial and peak serum ammonia levels were significantly higher in the seizure group than in the non-seizure group. There was no significant difference in the area under the curve of the serum NSE level or the initial and peak serum ammonia levels in terms of predicting the occurrence of seizures. CONCLUSION: In acute glufosinate poisoning, initial serum NSE levels may help in prediction of seizures.

Ammonia , Ammonium Compounds , Biomarkers , Emergency Service, Hospital , Herbicides , Humans , Neurons , Observational Study , Phosphopyruvate Hydratase , Poisoning , Retrospective Studies , Seizures
Article in English | WPRIM | ID: wpr-740756


BACKGROUND/AIMS: Irritable bowel syndrome (IBS) is a common disease characterized by intestinal dysmotility, the mechanism of which remains elusive. We aim to determine whether the high-affinity choline transporter 1 (CHT1), a determinant of cholinergic signaling capacity, modulates intestinal motility associated with stress-induced IBS. METHODS: A rat IBS model was established using chronic water avoidance stress (WAS). Colonic pathological alterations were evaluated histologically and intestinal motility was assessed by intestinal transit time and fecal water content (FWC). Visceral sensitivity was determined by visceromotor response to colorectal distension. RT-PCR, western blotting, and immunostaining were performed to identify colonic CHT1 expression. Contractility of colonic muscle strips was measured using isometric transducers. enzyme-linked immunosorbent assay was used to measure acetylcholine (ACh). We examined the effects of MKC-231, a choline uptake enhancer, on colonic motility. RESULTS: After 10 days of WAS, intestinal transit time was decreased and fecal water content increased. Visceromotor response magnitude in WAS rats in response to colorectal distension was significantly enhanced. Protein and mRNA CHT1 levels in the colon were markedly elevated after WAS. The density of CHT1-positive intramuscular interstitial cells of Cajal and myenteric plexus neurons in WAS rats was higher than in controls. Ammonium pyrrolidine dithiocarbamate partly reversed CHT1 upregulation and alleviated colonic hypermotility in WAS rats. Pharmacological enhancement of CHT1 activity by MKC-231 enhanced colonic motility in control rats via upregulation of CHT1 and elevation of ACh production. CONCLUSION: Upregulation of CHT1 in intramuscular interstitial cells of Cajal and myenteric plexus neurons is implicated in chronic stress-induced colonic hypermotility by modulation of ACh synthesis via nuclear factor-kappa B signaling.

Acetylcholine , Ammonium Compounds , Animals , Blotting, Western , Choline , Colon , Enzyme-Linked Immunosorbent Assay , Gastrointestinal Motility , Interstitial Cells of Cajal , Irritable Bowel Syndrome , Models, Animal , Myenteric Plexus , Neurons , Rats , RNA, Messenger , Transducers , Up-Regulation , Water
Article in English | WPRIM | ID: wpr-196851


A simple, rapid, and reliable UPLC-MS/MS method was developed and validated for the determination of tadalafil in human plasma. The plasma samples were deproteinized with acetonitrile. Chromatographic separation was performed on a Shiseido C18 (100 × 2.1 mm, 2.7 µm) column with isocratic elution using 2.0 mM ammonium acetate and acetonitrile (55:45, v/v) with 0.1% formic acid at a flow rate of 0.7 mL/min. The total run time was 1 min per sample. The quantitative analysis was performed using multiple reaction monitoring at transition of m/z 390.4 → 268.3 for tadalafil and m/z 475.3 → 283.3 for sildenafil as an internal standard. The method was fully validated over a concentration range of 5–1,000 ng/mL with a lower quantification limit of 5 ng/mL. Intra- and inter-day precision (relative standard deviation, %RSD) were within 8.4% and accuracy (relative error, %RE) was lower than -3.2%. The developed and validated method was successfully applied to a pharmacokinetic study of tadalafil (20 mg) in Korean healthy male subjects (n = 12).

Ammonium Compounds , Humans , Male , Methods , Pharmacokinetics , Plasma , Sildenafil Citrate , Tadalafil