Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 41
Filtrar
1.
JMIR Form Res ; 6(10): e40215, 2022 Oct 17.
Artigo em Inglês | MEDLINE | ID: mdl-36219745

RESUMO

BACKGROUND: COVID-19 has caused nearly 1 million deaths in the United States, not to mention job losses, business and school closures, stay-at-home orders, and mask mandates. Many people have suffered increased anxiety and depression since the pandemic began. Not only have mental health symptoms become more prevalent, but alcohol consumption has also increased during this time. Helplines offer important insight into both physical and mental wellness of a population by offering immediate, anonymous, cheap, and accessible resources for health and substance use disorders (SUD) that was unobstructed by many of the mandates of the pandemic. Further, the pandemic also launched the use of wastewater surveillance, which has the potential for tracking not only population infections but also consumption of substances such as alcohol. OBJECTIVE: This study assessed the feasibility of using multiple public surveillance metrics, such as helpline calls, COVID-19 cases, and alcohol metabolites in wastewater, to better understand the need for interventions or public health programs in the time of a public health emergency. METHODS: Ethanol metabolites were analyzed from wastewater collected twice weekly from September 29 to December 4, 2020, in a Midwestern state. Calls made to the helpline regarding housing, health care, and mental health/SUD were correlated with ethanol metabolites analyzed from wastewater samples, as well as the number of COVID-19 cases during the sampling period. RESULTS: Correlations were observed between COVID-19 cases and helpline calls regarding housing and health care needs. No correlation was observed between the number of COVID-19 cases and mental health/SUD calls. COVID-19 cases on Tuesdays were correlated with the alcohol metabolite ethyl glucuronide (EtG). Finally, EtG levels were negatively associated with mental health/SUD helpline calls. CONCLUSIONS: Although helpline calls provided critical services for health care and housing-related concerns early in the pandemic, evidence suggests helpline calls for mental health/SUD-related concerns were unrelated to COVID-19 metrics. Instead, COVID metrics were associated with alcohol metabolites in wastewater. Although this research was formative, with continued and expanded monitoring of population metrics, such as helpline usage, COVID-19 metrics, and wastewater, strategies can be implemented to create precision programs to address the needs of the population.

2.
Water Environ Res ; 92(10): 1741-1750, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-32762100

RESUMO

A review of 79 papers published in 2019 is presented. The topics ranged from detailed descriptions of analytical methods, to fate and occurrence studies, to ecological effects and sampling techniques for a wide variety of emerging contaminants likely to occur in agricultural environments. New methods and studies on veterinary pharmaceuticals, antibiotics, anthelmintics, and engineered nanomaterials in agricultural environments continue to expand our knowledge base on the occurrence and potential impacts of these compounds. This review is divided into the following sections: Introduction, Analytical Methods, Antibiotics in Agroecosystems, Pharmaceutical Fate and Occurrence, Anthelmintics and Engineered Nanomaterials. PRACTITIONER POINTS: New research describes innovative new techniques for emerging contaminant detection in agricultural settings Newer classes of contaminants include human and veterinary pharmaceuticals Research in nanomaterials show that these also occur in agricultural environments and will likely be topics of future work.


Assuntos
Preparações Farmacêuticas , Drogas Veterinárias , Poluentes Químicos da Água , Agricultura , Monitoramento Ambiental , Humanos , Poluentes Químicos da Água/análise
3.
Bull Environ Contam Toxicol ; 103(6): 808-813, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31602500

RESUMO

Certain microbes can biotransform antibiotics. Little is known about these microbes or the biotransformation processes. The objective of this study was to determine the effects of background nutrient conditions on a sulfonamide degrading culture and on its biotransformation of sulfadiazine (SDZ) with respect to transformation kinetics and transformation products. The mixed culture capable of degrading SDZ consisted primarily of three genera, Brevibacterium, Castellaniella and Leucobacter. The maximum biotransformation rate was 4.55 mg L-1 d-1 in the absence of background nutrients. Among the three background nutrient conditions tested, diluted R2A medium lead to the highest maximum SDZ biotransformation rates, followed by humic acid and glucose. 2-aminopyrimidine was the major SDZ biotransformation product under the background nutrient conditions tested, while another previously reported biotransformation product, sulfanilic acid, was further degraded by the mixed culture. The findings from this study can help improve our estimation of the fate of antibiotics in the environment.


Assuntos
Antibacterianos/metabolismo , Meios de Cultura/química , Microbiologia do Solo , Poluentes do Solo/metabolismo , Sulfadiazina/metabolismo , Actinobacteria/metabolismo , Alcaligenaceae/metabolismo , Biodegradação Ambiental , Biotransformação , Brevibacterium/metabolismo , Glucose/química , Substâncias Húmicas/análise , Cinética , Pirimidinas/química
4.
Water Environ Res ; 91(10): 1103-1113, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31420905

RESUMO

A review of 82 papers published in 2018 is presented. The topics ranged from detailed descriptions of analytical methods, to fate and occurrence studies, to ecological effects and sampling techniques for a wide variety of emerging contaminants likely to occur in agricultural environments. New methods and studies on veterinary pharmaceuticals, microplastics, and engineered nanomaterials in agricultural environments continue to expand our knowledge base on the occurrence and potential impacts of these compounds. This review is divided into the following sections: Introduction, Analytical Methods, Fate and Occurrence, Pharmaceutical Metabolites, Anthelmintics, Microplastics, and Engineered Nanomaterials. PRACTITIONER POINTS: New research describes innovative new techniques for emerging contaminant detection in agricultural settings. Newer classes of contaminants include human and veterinary pharmaceuticals. Research in microplastics and nanomaterials shows that these also occur in agricultural environments and will likely be topics of future work.


Assuntos
Monitoramento Ambiental , Poluentes Químicos da Água , Agricultura , Ecologia , Humanos , Plásticos
5.
Water Environ Res ; 90(10): 1348-1370, 2018 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-30126486

RESUMO

A total of 75 papers published in 2017 were reviewed ranging from detailed descriptions of analytical methods, to fate and occurrence studies, to ecological effects and sampling techniques for a wide variety of emerging contaminants likely to occur in agricultural environments. New methods and studies on veterinary pharmaceuticals, steroids, antibiotic resistance genes, and engineered nanoparticles agricultural environments continue to expand our knowledge base on the occurrence and potential impacts of these compounds. This review is divided into the following sections: Introduction, Analytical Methods, Fate and Occurrence, Pharmaceutical Metabolites, Anthelmintics, Antibiotic Resistence Genes, and Engineered Nanomaterials.


Assuntos
Agricultura , Monitoramento Ambiental , Poluentes Ambientais/análise , Poluentes Ambientais/metabolismo
6.
J Sep Sci ; 41(5): 1074-1082, 2018 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-29232050

RESUMO

Affinity sorbents using bovine serum albumin as a binding agent were developed and tested for the extraction of environmental contaminants from water. Computer simulations based on a countercurrent distribution model were also used to study the behavior of these sorbents. Several model drugs, pesticides, and hormones of interest as emerging contaminants were considered in this work, with carbamazepine being used as a representative analyte when coupling the albumin column on-line with liquid chromatography and tandem mass spectrometry. The albumin column was found to be capable of extracting carbamazepine from aqueous solutions that contained trace levels of this analyte. Further studies of the bovine serum albumin sorbent indicated that it had higher retention under aqueous conditions than a traditional C18 support for most of the tested emerging contaminants. Potential advantages of using these protein-based sorbents included the low cost of bovine serum albumin and its ability to bind to a relatively wide range of drugs and related compounds. It was also shown how simulations could be used to describe the elution behavior of the model compounds on the bovine serum albumin sorbents as an aid in optimizing the retention and selectivity of these supports for use with liquid chromatography or methods such as liquid chromatography with tandem mass spectrometry.


Assuntos
Hormônios/análise , Praguicidas/análise , Preparações Farmacêuticas/análise , Soroalbumina Bovina/química , Poluentes Químicos da Água/análise , Adsorção , Animais , Sítios de Ligação , Bovinos , Cromatografia Líquida/instrumentação , Espectrometria de Massas em Tandem/instrumentação
7.
Water Environ Res ; 89(10): 897-920, 2017 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-28954647

RESUMO

A total of 79 papers published in 2016 were reviewed ranging from detailed descriptions of analytical methods, to fate and occurrence studies, to ecological effects and sampling techniques for a wide variety of emerging contaminants likely to occur in agricultural environments. New methods and studies on veterinary pharmaceuticals, steroids, antibiotic resistance genes, cyanotoxins, and potential effects of biochar use in agricultural environments continue to expand our knowledge base on the occurrence and potential impacts of these compounds. This review is divided into the following sections: Introduction, Analytical Methods, Steroid Hormones, Anthelmintics, Antibiotic Fate and Occurrence, Antibiotic Resistance Genes, Cyanotoxins, and Implications of Biochar in Agricultural Environments.


Assuntos
Agricultura , Monitoramento Ambiental , Poluentes Ambientais/análise , Ecologia
8.
Water Environ Res ; 88(10): 913-29, 2016 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-27620078

RESUMO

A total of 59 papers published in 2015 were reviewed ranging from detailed descriptions of analytical methods, to fate and occurrence studies, to ecological effects and sampling techniques for a wide variety of emerging contaminants likely to occur in agricultural environments. New methods and studies on veterinary pharmaceuticals, steroids, antibiotic resistance genes in agricultural environments continue to expand our knowledge base on the occurrence and potential impacts of these compounds. This review is divided into the following sections: Introduction, Analytical Methods, Steroid Hormones, Pharmaceutical Contaminants, Transformation Products, and "Antibiotic Resistance, Drugs, Bugs and Genes".


Assuntos
Agricultura , Monitoramento Ambiental , Poluentes Ambientais , Ecologia , Preparações Farmacêuticas
9.
Water Environ Res ; 87(10): 868-1937, 2015 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-26420073

RESUMO

A total of 43 papers published in 2014 were reviewed ranging from detailed descriptions of analytical methods, to fate and occurrence studies, to measuring and predicting biological effects for a wide variety of emerging contaminants likely to occur in agricultural environments. New methods and studies on veterinary pharmaceuticals, natural and synthetics steroids, and antibiotic resistance genes in agricultural environments continue to expand our knowledge base on the occurrence and potential impacts of these compounds. This review is divided into the following sections: Introduction, Analytical Methods, Occurrence and Fate, Antibiotic Resistance Genes, and Risk Assessment.

10.
Toxins (Basel) ; 6(2): 488-508, 2014 Jan 28.
Artigo em Inglês | MEDLINE | ID: mdl-24476710

RESUMO

Several groups of microorganisms are capable of producing toxins in aquatic environments. Cyanobacteria are prevalent blue green algae in freshwater systems, and many species produce cyanotoxins which include a variety of chemical irritants, hepatotoxins and neurotoxins. Production and occurrence of potent neurotoxic cyanotoxins ß-N-methylamino-L-alanine (BMAA), 2,4-diaminobutyric acid dihydrochloride (DABA), and anatoxin-a are especially critical with environmental implications to public and animal health. Biomagnification, though not well understood in aquatic systems, is potentially relevant to both human and animal health effects. Because little is known regarding their presence in fresh water, we investigated the occurrence and potential for bioaccumulation of cyanotoxins in several Nebraska reservoirs. Collection and analysis of 387 environmental and biological samples (water, fish, and aquatic plant) provided a snapshot of their occurrence. A sensitive detection method was developed using solid phase extraction (SPE) in combination with high pressure liquid chromatography-fluorescence detection (HPLC/FD) with confirmation by liquid chromatography-tandem mass spectrometry (LC/MS/MS). HPLC/FD detection limits ranged from 5 to 7 µg/L and LC/MS/MS detection limits were <0.5 µg/L, while detection limits for biological samples were in the range of 0.8-3.2 ng/g depending on the matrix. Based on these methods, measurable levels of these neurotoxic compounds were detected in approximately 25% of the samples, with detections of BMAA in about 18.1%, DABA in 17.1%, and anatoxin-a in 11.9%.


Assuntos
Diamino Aminoácidos/análise , Aminobutiratos/análise , Toxinas Bacterianas/análise , Tropanos/análise , Poluentes Químicos da Água/análise , Animais , Toxinas de Cianobactérias , Monitoramento Ambiental , Peixes , Lagos , Nebraska , Traqueófitas/química , Abastecimento de Água
11.
Toxicon ; 76: 316-25, 2013 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-24140919

RESUMO

Blue-green algae, also known as cyanobacteria, can produce several different groups of toxins in the environment including hepatotoxins (microcystins), neurotoxic non-protein amino acids ß-methylamino-l-alanine (BMAA), and 2,4-diaminobutyric (DABA), as well as the bicyclic amine alkaloid anatoxin-a. Few studies have addressed the methods necessary for an accurate determination of cyanotoxins in environmental samples, and none have been published that can detect these cyanotoxins together in a single sample. Cyanotoxins occur in a wide range of environmental samples including water, fish, and aquatic plant samples. Using polymeric cation exchange solid phase extraction (SPE) coupled with liquid chromatography and fluorescence detection (HPLC/FD), and liquid chromatography ion trap tandem mass spectrometry (LC/MS/MS), these compounds can for the first time be simultaneously quantified in a variety of environmental sample types. The extraction method for biological samples can distinguish bound and free cyanotoxins. Detection limits for water ranged from 5 to 7 µg/L using HPLC/FD, while detection limits for and LC/MS were in the range of 0.8-3.2 µg/L.


Assuntos
Diamino Aminoácidos/análise , Aminobutiratos/análise , Cianobactérias/química , Monitoramento Ambiental/métodos , Tropanos/análise , Cromatografia Líquida de Alta Pressão , Cromatografia Líquida , Toxinas de Cianobactérias , Água Doce/química , Espectrometria de Massas em Tandem
12.
Food Microbiol ; 35(2): 108-15, 2013 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-23664261

RESUMO

The effect of nitrite and erythorbate on Clostridium perfringens spore germination and outgrowth in ham during abusive cooling (15 h) was evaluated. Ham was formulated with ground pork, NaNO2 (0, 50, 100, 150 or 200 ppm) and sodium erythorbate (0 or 547 ppm). Ten grams of meat (stored at 5 °C for 3 or 24 h after preparation) were transferred to a vacuum bag and inoculated with a three-strain C. perfringens spore cocktail to obtain an inoculum of ca. 2.5 log spores/g. The bags were vacuum-sealed, and the meat was heat treated (75 °C, 20 min) and cooled within 15 h from 54.4 to 7.2 °C. Residual nitrite was determined before and after heat treatment using ion chromatography with colorimetric detection. Cooling of ham (control) stored for 3 and 24 h, resulted in C. perfringens population increases of 1.46 and 4.20 log CFU/g, respectively. For samples that contained low NaNO2 concentrations and were stored for 3 h, C. perfringens populations of 5.22 and 2.83 log CFU/g were observed with or without sodium erythorbate, respectively. Residual nitrite was stable (p > 0.05) for both storage times. Meat processing ingredients (sodium nitrite and sodium erythorbate) and their concentrations, and storage time subsequent to preparation of meat (oxygen content) affect C. perfringens spore germination and outgrowth during abusive cooling of ham.


Assuntos
Ácido Ascórbico/farmacologia , Clostridium perfringens/efeitos dos fármacos , Conservação de Alimentos/métodos , Conservantes de Alimentos/farmacologia , Produtos da Carne/microbiologia , Nitrito de Sódio/farmacologia , Esporos Bacterianos/crescimento & desenvolvimento , Animais , Clostridium perfringens/crescimento & desenvolvimento , Contagem de Colônia Microbiana , Conservação de Alimentos/instrumentação , Esporos Bacterianos/efeitos dos fármacos , Suínos , Temperatura , Vácuo
13.
Pest Manag Sci ; 69(2): 285-91, 2013 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-22933384

RESUMO

BACKGROUND: Neonicotinoid insecticides are generally efficacious against many turfgrass pests, including several important phloem-feeding insects. However, inconsistencies in control of western chinch bugs, Blissus occiduus, have been documented in field efficacy studies. This research investigated the efficacy of three neonicotinoid insecticides (clothianidin, imidacloprid and thiamethoxam) against B. occiduus in buffalograss under field conditions and detected statistically significant differences in B. occiduus numbers among treatments. A subsequent study documented the relative quantity and degradation rate of these insecticides in buffalograss systemic leaf tissues, using HPLC. RESULTS: Neonicotinoid insecticides initially provided significant reductions in B. occiduus numbers, but mortality diminished over the course of the field studies. Furthermore, while all three neonicotinoids were present in the assayed buffalograss leaf tissues, imidacloprid concentrations were significantly higher than those of clothianidin and thiamethoxam. Over the course of the 28 day study, thiamethoxam concentrations declined 700-fold, whereas imidacloprid and clothianidin declined only 70-fold and 60-fold respectively. CONCLUSIONS: Field studies continued to verify inconsistencies in B. occiduus control with neonicotinoid insecticides. This is the first study to document the relative concentrations of topically applied neonicotinoid insecticides in buffalograss systemic leaf tissues.


Assuntos
Heterópteros/efeitos dos fármacos , Imidazóis/toxicidade , Inseticidas/toxicidade , Nitrocompostos/toxicidade , Poaceae/parasitologia , Animais , Controle de Insetos , Neonicotinoides , Doenças das Plantas/parasitologia , Folhas de Planta/parasitologia
14.
Anal Bioanal Chem ; 405(5): 1759-71, 2013 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-23208286

RESUMO

Analytical methods for the determination of several natural and synthetic steroids in water and solid samples were developed using liquid chromatography tandem mass spectrometry. Atmospheric pressure photoionization (APPI) in positive mode was used as the source which appeared to reduce background and interferences as compared to electrospray ionization. Toluene was identified as the most appropriate dopant and its concentration optimized to enhance ionization efficiency. Method detection limits were in the low-nanogram-per-liter range for water samples using on-line solid-phase extraction and near 0.2 ng/g using microwave-assisted solvent extraction for solid samples. This on-line method, using APPI as a source and toluene as a dopant, is beneficial as it saves time due to on-line extraction and reduces interference and matrix effects using gas-phase photoionization. Groundwater, wastewater, runoff, and soil samples were collected and analyzed using the method indicating that traces of several androgens, estrogens, and other steroid-like compounds do occur in samples impacted by animal waste.


Assuntos
Poluentes do Solo/análise , Solo/análise , Extração em Fase Sólida/métodos , Esteroides/análise , Espectrometria de Massas em Tandem/métodos , Poluentes Químicos da Água/análise , Água/análise , Cromatografia Líquida/métodos , Limite de Detecção , Micro-Ondas , Poluentes do Solo/isolamento & purificação , Esteroides/isolamento & purificação , Poluentes Químicos da Água/isolamento & purificação
15.
Ann Vasc Surg ; 26(8): 1106-13, 2012 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-22835564

RESUMO

Leg swelling is a common cause for vascular surgical evaluation, and iliocaval obstruction due to May-Thurner syndrome (MTS) can be difficult to diagnose. Physical examination and planar radiographic imaging give anatomic information but may miss the fundamental pathophysiology of MTS. Similarly, duplex ultrasonographic examination of the legs gives little information about central impedance of venous return above the inguinal ligament. We have modified the technique of duplex ultrasonography to evaluate the flow characteristics of the leg after tourniquet-induced venous engorgement, with the objective of revealing iliocaval obstruction characteristic of MTS. Twelve patients with signs and symptoms of MTS were compared with healthy control subjects for duplex-derived maximal venous outflow velocity (MVOV) after tourniquet-induced venous engorgement of the leg. The data for healthy control subjects were obtained from a previous study of asymptomatic volunteers using the same MVOV maneuvers. The tourniquet-induced venous engorgement mimics that caused during vigorous exercise. A right-to-left ratio of MVOV was generated for patient comparisons. Patients with clinical evidence of MTS had a mean right-to-left MVOV ratio of 2.0, asymptomatic control subjects had a mean ratio of 1.3, and MTS patients who had undergone endovascular treatment had a poststent mean ratio of 1.2 (P = 0.011). Interestingly, computed tomography and magnetic resonance imaging results, when available, were interpreted as positive in only 53% of the patients with MTS according to both our MVOV criteria and confirmatory venography. After intervention, the right-to-left MVOV ratio in the MTS patients was found to be reduced similar to asymptomatic control subjects, indicating a relief of central venous obstruction by stenting the compressive MTS anatomy. Duplex-derived MVOV measurements are helpful for detection of iliocaval venous obstruction, such as MTS. Right-to-left MVOV ratios and postengorgement spectral analysis are helpful adjuncts to duplex imaging for leg swelling. The MVOV maneuvers are well tolerated by patients and yields physiological data regarding central venous obstruction that computed tomography and magnetic resonance imaging fail to detect.


Assuntos
Veia Ilíaca/diagnóstico por imagem , Síndrome de May-Thurner/diagnóstico por imagem , Ultrassonografia Doppler Dupla , Adulto , Velocidade do Fluxo Sanguíneo , Constrição Patológica , Procedimentos Endovasculares/instrumentação , Feminino , Humanos , Hiperemia/diagnóstico por imagem , Hiperemia/fisiopatologia , Veia Ilíaca/fisiopatologia , Imageamento por Ressonância Magnética , Masculino , Síndrome de May-Thurner/fisiopatologia , Síndrome de May-Thurner/terapia , Flebografia/métodos , Valor Preditivo dos Testes , Fluxo Sanguíneo Regional , Estudos Retrospectivos , Stents , Tomografia Computadorizada por Raios X , Torniquetes , Resultado do Tratamento , Adulto Jovem
16.
IUBMB Life ; 64(2): 169-79, 2012 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-22162200

RESUMO

Depurinating DNA adducts formed by aromatic hydrocarbons and catechol estrogen quinones play a major role in cancer initiation. Most of these adducts depurinate instantaneously, but some guanine adducts depurinate from DNA with half-lives of hours. We report here, that after 10 h at 37 °C, reaction of estradiol-3,4-quinone (E(2)-3,4-Q) with ds-DNA to yield N7Gua and N3Ade adducts was complete and more efficient than with ss-DNA. When E(2)-3,4-Q reacted with t-RNA, no adducts were detected after 10 h, and the level of N3Ade and N7Gua adducts after 10 days was less than half that with ss-DNA after 10 h. Reaction of E(2)-3,4-Q and dG yielded 4-OHE(2)-1-N7dG, which spontaneously depurinated to yield 4-OHE(2)-1-N7Gua. To investigate the mechanism of depurination, E(2)-3,4-Q was reacted with carbocyclicdeoxyguanosine, in which the ring oxygen of the deoxyribose moiety is substituted with CH(2) , and depurination was observed. The results from this experiment demonstrate that the oxocarbenium ion mechanism plays the major role in depurination and provides the first experimental evidence for this mechanism. A newly discovered ß-elimination mechanism also plays a minor role in depurination. Understanding why the depurinating estrogen-DNA adducts come from DNA, and not from RNA, underscores the critical role that these adducts play in initiating cancer.


Assuntos
Carcinógenos/química , Transformação Celular Neoplásica , Adutos de DNA/química , Dano ao DNA , Estradiol/análogos & derivados , Ciclopentanos/química , Adutos de DNA/síntese química , DNA de Cadeia Simples/química , Desoxiguanosina/análogos & derivados , Desoxiguanosina/química , Estradiol/química , Humanos , Concentração de Íons de Hidrogênio , Cinética , Purinas/química , RNA de Transferência/química
17.
Food Chem Toxicol ; 49(7): 1560-4, 2011 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-21473896

RESUMO

Blue-green algae (BGA) have been consumed as food and herbal medicine for centuries. However, safety for their consumption has not been well investigated. This study was undertaken to evaluate in vitro and in vivo toxicity of cultivated Nostoc commune var. sphaeroides Kützing (NO) and Spirulina platensis (SP). Neither NO nor SP contained detectable levels of microcystin (MC)-LA, MC-RR, MC-LW and MC-LR by LC/MS/MS. Cell viability remained ∼70-80% when HepG2 cells were incubated with 0-500 µg/ml of hexane, chloroform, methanol and water-extractable fractions of NO and SP. Four-week-old male and female C57BL/6J mice were fed an AIN-93G/M diet supplemented with 0%, 2.5% or 5% of NO and SP (wt/wt) for 6 months. For both genders, BGA-rich diets did not induce noticeable abnormality in weight gain and plasma alanine aminotransferase (ALT) and aspartate aminotransferase concentrations except a significant increase in plasma ALT levels by 2.5% NO supplementation in male mice at 6 month. Histopathological analysis of livers, however, indicated that BGA did not cause significant liver damage compared with controls. In conclusion, our results suggest that NO and SP are free of MC and the long-term dietary supplementation of up to 5% of the BGA may be consumed without evident toxic side-effects.


Assuntos
Suplementos Nutricionais/toxicidade , Avaliação Pré-Clínica de Medicamentos/métodos , Nostoc commune/química , Spirulina/química , Testes de Toxicidade/métodos , Alanina Transaminase/sangue , Animais , Aspartato Aminotransferases/sangue , Toxinas Bacterianas/análise , Sobrevivência Celular , Cromatografia Líquida , Feminino , Células Hep G2 , Humanos , Fígado/patologia , Masculino , Toxinas Marinhas/análise , Espectrometria de Massas , Camundongos , Camundongos Endogâmicos C57BL , Microcistinas/análise
18.
Environ Sci Technol ; 45(8): 3643-9, 2011 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-21452829

RESUMO

The chemical oxidant permanganate (MnO(4)(-)) has been shown to effectively transform hexahydro-1,3,5-trinitro-1,3,5-triazine (RDX) at both the laboratory and field scales. We treated RDX with MnO(4)(-) with the objective of quantifying the effects of pH and temperature on destruction kinetics and determining reaction rates. A nitrogen mass balance and the distribution of reaction products were used to provide insight into reaction mechanisms. Kinetic experiments (at pH ∼ 7, 25 °C) verified that RDX-MnO(4)(-) reaction was first-order with respect to MnO(4)(-) and initial RDX concentration (second-order rate: 4.2 × 10(-5) M(-1) s(-1)). Batch experiments showed that choice of quenching agents (MnSO(4), MnCO(3), and H(2)O(2)) influenced sample pH and product distribution. When MnCO(3) was used as a quenching agent, the pH of the RDX-MnO(4)(-) solution was relatively unchanged and N(2)O and NO(3)(-) constituted 94% of the N-containing products after 80% of the RDX was transformed. On the basis of the preponderance of N(2)O produced under neutral pH (molar ratio N(2)O/NO(3) ∼ 5:1), no strong pH effect on RDX-MnO(4)(-) reaction rates, a lower activation energy than the hydrolysis pathway, and previous literature on MnO(4)(-) oxidation of amines, we propose that RDX-MnO(4)(-) reaction involves direct oxidation of the methylene group (hydride abstraction), followed by hydrolysis of the resulting imides, and decarboxylation of the resulting carboxylic acids to form N(2)O, CO(2), and H(2)O.


Assuntos
Substâncias Explosivas/química , Compostos de Manganês/química , Óxidos/química , Triazinas/química , Poluentes Químicos da Água/química , Substâncias Explosivas/análise , Cinética , Oxirredução , Triazinas/análise , Poluentes Químicos da Água/análise
19.
J Food Sci ; 75(6): E323-9, 2010 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-20722916

RESUMO

This study was conducted to evaluate the effect of pulsed electric field (PEF) treatment on anthocyanin extraction from red cabbage using water as a solvent. Mashed cabbage was placed in a batch treatment chamber and subjected to PEF (2.5 kV/cm electric field strength; 15 micros pulse width and 50 pulses, specific energy 15.63 J/g). Extracted anthocyanin concentrations (16 to 889 microg/mL) were determined using HPLC. Heat and light stabilities of the control and PEF-treated samples, having approximately the same initial concentrations, were studied. PEF treatments enhanced total anthocyanin extraction in water from red cabbage by 2.15 times with a higher proportion of nonacylated forms than the control (P < 0.05). The heat and light stabilities of the PEF-treated samples and control samples were not significantly different (P > 0.05). Practical Application: An innovative pretreatment technology, pulsed electric field processing, enhanced total anthocyanin extraction in water from red cabbage by 2.15 times. Manufacturers of natural colors can use this technology to extract anthocyanins from red cabbage efficiently.


Assuntos
Antocianinas/isolamento & purificação , Antioxidantes/isolamento & purificação , Brassica/química , Corantes de Alimentos/isolamento & purificação , Tecnologia de Alimentos/métodos , Folhas de Planta/química , Acilação , Antocianinas/análise , Antocianinas/química , Antocianinas/efeitos da radiação , Antioxidantes/análise , Antioxidantes/química , Antioxidantes/efeitos da radiação , Cromatografia Líquida de Alta Pressão , Técnicas Eletroquímicas/instrumentação , Corantes de Alimentos/análise , Corantes de Alimentos/química , Corantes de Alimentos/efeitos da radiação , Luz/efeitos adversos , Espectrometria de Massas , Fatores de Tempo
20.
J Surg Res ; 160(1): 9-13, 2010 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-19726059

RESUMO

BACKGROUND: A primary component in the development of intimal hyperplasia (IH) in response to vascular injury is basement membrane remodeling. Matrix metalloproteinases (MMPs) play a major role in this process by degradation of basement membrane proteins, mainly collagen type IV. Vascular injury initiates an inflammatory cascade with the release of tumor necrosis factor-alpha (TNFalpha), interleukin-1beta (IL-1beta), and C-reactive protein (CRP). We hypothesize serum levels of these elements may serve as biomarkers of the development of IH. METHODS AND RESULTS: At baseline, 2, 7, 10, and 14 days post-balloon angioplasty of the carotid artery, rat tissue samples were stained with Masson trichrome elastin to examine IH. Intima:media ratios (I:M) increased significantly over time postinjury. Serum samples were collected at the time of tissue sampling, and levels of MMP-2, MMP-9, collagen type IV, TNFalpha, IL-1beta, and CRP were assayed using sandwich enzyme-linked immunosorbent assay (ELISA). MMP-2 serum levels at 7, 10, and 14 days postinjury were significantly elevated compared with baseline. Other elements were not significantly elevated. CONCLUSION: Early and persistent elevation in the serum levels of MMP-2 may be a useful biomarker of basement membrane remodeling and the presence of IH.


Assuntos
Lesões das Artérias Carótidas/sangue , Colágeno Tipo IV/metabolismo , Citocinas/sangue , Metaloproteinase 2 da Matriz/sangue , Túnica Íntima/patologia , Animais , Biomarcadores/sangue , Lesões das Artérias Carótidas/patologia , Feminino , Hiperplasia , Período Pós-Operatório , Ratos , Ratos Sprague-Dawley
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...