Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Resultados 1 - 20 de 56
Filtrar
1.
Proteome Sci ; 15: 4, 2016.
Artículo en Inglés | MEDLINE | ID: mdl-28270742

RESUMEN

BACKGROUND: Eggshells which consist largely of calcareous outer shell and shell membranes, constitute a significant part of poultry hatchery waste. The shell membranes (ESM) not only contain proteins that originate from egg whites but also from the developing embryos and different contaminants of microbial and environmental origins. As feed supplements, during post hatch growth, the hatchery egg shell membranes (HESM) have shown potential for imparting resistance of chickens to endotoxin stress and exert positive health effects. Considering that these effects are mediated by the bioactive proteins and peptides present in the membrane, the objective of the study was to identify the protein profiles of hatchery eggshell membranes (HESM). METHODS: Hatchery egg shell membranes were extracted with acidified methanol and a guanidine hydrochloride buffer then subjected to reduction/alkylation, and trypsin digestion. The methanol extract was additionally analyzed by matrix assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF-MS). The tryptic digests were analyzed by liquid chromatography and tandem mass spectrometry (LC-MS-MS) to identify the proteins. RESULTS: Our results showed the presence of several proteins that are inherent and abundant in egg white such as, ovalbumin, ovotransferrin, ovocleidin-116, and lysozyme, and several proteins associated with cytoskeletal, cell signaling, antimicrobial, and catalytic functions involving carbohydrate, nucleic acid, and protein metabolisms. There were some blood derived proteins most likely originating from the embryos and several other proteins identified with different aerobic, anaerobic, gram positive, gram negative, soil, and marine bacterial species some commensals and others zoonotic. CONCLUSION: The variety of bioactive proteins, particularly the cell signaling and enzymatic proteins along with the diverse microbial proteins, make the HESM suitable for nutritional and biological application to improve post hatch immunity of poultry.

2.
Avian Dis ; 54(4): 1166-71, 2010 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-21313835

RESUMEN

Tibial dyschondroplasia (TD) is a poultry leg problem that affects the proximal growth plate of the tibia, preventing its transition to bone. To understand the disease-induced proteomic changes, we compared the protein extracts of cartilage from normal and TD-affected growth plates. TD was induced by feeding thiram to chickens 2 wk before tissue harvest. Proteins were extracted from whole tissues and from conditioned media (CM) prepared by incubating appropriate growth plate tissues in serum-free culture medium for 48 hr. The extracts were prefractionated to contain proteins ranging between 10 and 100 kD. Equal amounts of proteins were subjected to 2D gel electrophoresis with three individual samples per group. The gels were silver stained, and digital images were compared and analyzed with Melanie software to determine differentially expressed protein spots. On comparison of two sets of gels, 47 matching spots were detected in tissue extracts and 27 in CM extracts. Among the matching spots, 12 were determined to be down-regulated in tissue extracts (P < or = 0.05) and two in CM extracts (P < or = 0.05) of TD-affected growth plates. Altogether, 32 protein spots could be identified in both tissue and CM extracts by in-gel trypsin digestion, followed by peptide mass fingerprinting and mass spectrometry (MS)/MS fragmentation. The down-regulated proteins included alpha-enolase, G protein, origin recognition complex, peptidyl prolyl isomerase, calumenin, type II collagen precursor, and the expressed sequence tag pgm2n.pk014.f20, a protein with homology to human reticulocalbin-3 (RCN3). Most of the downregulated proteins are associated with signal transduction, energy metabolism, and secretory functions that are integral to cell viability. Consistent with our earlier findings that the TD chondrocytes are nonviable, the current results suggest that thiram very likely interferes with basic metabolic functions of chondrocytes, leading to their death and, consequently, to the pathogenesis of TD.


Asunto(s)
Cartílago/metabolismo , Regulación de la Expresión Génica/fisiología , Placa de Crecimiento/metabolismo , Osteocondrodisplasias/veterinaria , Enfermedades de las Aves de Corral/metabolismo , Proteómica , Animales , Pollos , Osteocondrodisplasias/metabolismo
3.
J Econ Entomol ; 102(6): 2224-32, 2009 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-20069852

RESUMEN

The purpose of this study was to develop and evaluate lures for adult green June beetles, Cotinis nitida (L.) (Coleoptera: Scarabaeidae), for future use in a mass trapping program. Volatile organic compounds collected from headspace of green June beetles feeding on fermenting ripe apple (Malus spp.), the natural lure that elicits feeding aggregations, were identified and confirmed by gas chromatography and mass spectrometry. Yellow funnel traps baited with 91% isopropanol or the five component blend were equally effective in eliciting aggregation behavior and often more attractive to green June beetles than the natural lure. In 2008, three trap lines adjacent and parallel to the perimeter of two vineyards, each with 12 Xpando yellow funnel traps baited with either 91% isopropanol or the five component blend, differed in catch of green June beetles across sample dates, and sample date by bait interaction but there were no differences among these two baits. A season total of 324,007 green June beetle were captured by these 36 baited traps. A brief review is included of fermentation volatiles attractive to insects. We conclude with the potential cost to use mass trapping against adult green June beetles.


Asunto(s)
Escarabajos/química , Conducta Alimentaria , Control de Insectos , Feromonas/aislamiento & purificación , Compuestos Orgánicos Volátiles/aislamiento & purificación , Animales , Femenino , Fermentación , Frutas , Masculino , Malus
4.
Poult Sci ; 88(2): 372-9, 2009 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-19151352

RESUMEN

Matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF-MS) was used to screen avian heterophils in the m/z range of 1 to 20 kDa with an objective to identify specific cell-associated peptides that may be reflective of their functional physiology. The MALDI-TOF-MS profiles of crude heterophil extract showed a high intensity peak with average mass of m/z 3916.1 for chicken and m/z 4129.6 for turkey. To identify these peaks, we first purified m/z 3916.1 from chicken bone marrow extract using reverse-phase high performance liquid chromatography (RP-HPLC). Edman sequencing and peptide mass fingerprinting exclusively confirmed this peptide as beta-defensin 2 (BD2) or gallinacin-2, a broad-range antimicrobial peptide. A Uniprot database search followed by the MASCOT sequence query revealed m/z 4129.6 to be the corresponding turkey ortholog of avian beta-defensin 2 (AvBD2), also called turkey heterophil peptide 2. Both AvBD2 peptides are 36 amino acids long including a highly conserved region with 6 invariant cysteines forming the 3 disulfide bonds characteristic of defensins. The method confirmed the existence of the complete mature peptide sequence of the turkey heterophilic BD2 previously proposed based on cDNA analysis. These results demonstrate that screening of the crude extract by MALDI-TOF-MS can identify cell- or tissue-associated peptides in their functional or mature forms, raising the possibility that such peptides can be used as biomarkers in their altered physiological states.


Asunto(s)
Anticuerpos Heterófilos/metabolismo , Células Sanguíneas/metabolismo , Pollos/fisiología , Pavos/fisiología , beta-Defensinas/química , beta-Defensinas/aislamiento & purificación , Secuencia de Aminoácidos , Animales , Cromatografía Líquida de Alta Presión , Datos de Secuencia Molecular , Espectrometría de Masa por Ionización de Electrospray , Espectrometría de Masa por Láser de Matriz Asistida de Ionización Desorción
5.
Biochem Pharmacol ; 38(2): 279-87, 1989 Jan 15.
Artículo en Inglés | MEDLINE | ID: mdl-2914011

RESUMEN

The binding of [ring-3H]4,4'-methylenebis(2-chloroaniline) (MOCA) to rat liver DNA following i.p. injection is demonstrated. Three discrete adducts were eluted on HPLC following enzymic hydrolysis to the nucleoside level. Three adducts, with the same retention times on HPLC, were present after i.p. injection of the N-acetyl derivative of MOCA tritiated in the benzene rings. Only two of these adducts were found when the N-acetyl derivative, tritiated on the acetyl group, was used. Thus, at least one of the adducts formed by MOCA is not acetylated. The N-hydroxy derivative of MOCA was synthesised and reacted with DNA in vitro. Following enzymic hydrolysis of this DNA, the major product was shown to co-elute with the radiolabelled non-acetylated adduct produced in the liver DNA of animals injected with [ring-3H]MOCA. This same compound was also isolated following the reaction of N-hydroxy-4-amino-3-chlorobenzyl alcohol with DNA, and subsequent enzymic hydrolysis. The NMR and mass spectra of the synthetic adduct were consistent with N-(deoxyadenosin-8-yl)-4-amino-3-chlorobenzyl alcohol. Thus, the major adduct formed in vivo has involved cleavage of the bond between the methylene bridge and one of the aromatic nuclei of MOCA.


Asunto(s)
Compuestos de Bencidrilo/metabolismo , Daño del ADN , ADN/metabolismo , Metilenobis (cloroanilina)/metabolismo , Acetilación , Animales , Biotransformación , Cromatografía Líquida de Alta Presión , Técnicas In Vitro , Hígado/metabolismo , Espectroscopía de Resonancia Magnética , Masculino , Ratas , Relación Estructura-Actividad
6.
J Am Soc Mass Spectrom ; 5(2): 58-63, 1994 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-24222516

RESUMEN

Product-ion studies of source-produced ions corresponding to acetylated and nonacetylated N (2)- and C8-substituted aminofluorene adducts of deoxyguanosine were conducted to identify specific fragmentation pathways differentiating the isomers and to determine the influence of the acetyl group on the fragmentation of the arylamide modified deoxyguanosine adducts. The collision-induced dissociation spectra of the BHZ 2 (+) ion and other significant source-produced ions showed no evidence to suggest that ketene loss (deacetylation) resulted in significant alteration of the structure of the adducts. However, other significant ion formation processes, particularly loss of water from the N (2)-substituted arylamide did appear to require rearrangement, likely involving bond formation between the carcinogen moiety (acetyl group) and the N1 or N2 position of the guanine base. The combined loss of ketene and water constitute a fragmentation pattern specific for the N (2)-arylamide, 3-(deoxyguanosin-N (2)-yl)-2-acetylaminofluorene.

7.
J Am Soc Mass Spectrom ; 3(4): 360-71, 1992 May.
Artículo en Inglés | MEDLINE | ID: mdl-24243047

RESUMEN

An analytical strategy using fast atom bombardment (FAB) ionization and tandem mass spectrometry has been developed to determine the molecular weight and major fragment ions, and to provide limited structural characterization of low picomole levels of carcinogen-nucleoside adducts. This strategy consists of three main components: (1) the sensitivity for analysis by FAB combined with mass spectrometry is increased via chemical derivatization; (2) the nucleoside adducts are selectively detected by using constant neutral loss scans; and (3) structurally characteristic fragments are obtained by using daughter ion scans. Trimethylsilyl derivatized arylamine-nucleoside adducts have been detected at levels as low as a few picomoles by using this approach. After experimental determination of the mass of the BH 2 (+) fragment ion, daughter ion spectra have been used to probe the structure specificity associated with collision-activated decomposition of this fragment. With model C-8 substituted arylamine adducts [N-(deoxyguanosin-8-yl)-4-aminobiphenyl, N-(deoxyadenosin--yl)-4-aminobiphenyl, and N-(deoxyguanosin-8-yl)-2-aminofluorene], nucleoside-specific and carcinogen-specific fragmentation have been observed in daughter ion spectra.

8.
J Am Soc Mass Spectrom ; 6(4): 248-56, 1995 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-24214170

RESUMEN

The use of fast-atom bombardment ionization-tandem mass spectrometry approaches, with collision energies on the order of 30-50 eV, was developed for the analysis of low picomole quantities of polycyclic aromatic hydrocarbon dihydrodiol-epoxide deoxynucleoside adducts. This strategy combines three experimental techniques: (1) product ion scans, (2) constant neutral loss scans, and (3) precursor ion scans. Product ion scans of the protonated molecule or the BH 2 (+) ion that results from loss of the deoxyribose were dominated by fragments associated with cleavage of the sigma bond between the dihydrodiol-epoxide moiety and the nucleobase. Constant neutral loss scans were based upon the loss of deoxyribose (116 u) or the combined loss of the deoxynucleoside, water, and carbon monoxide (313 u); precursor ion scans utilized the latter fragment. The formation of trimethylsilyl derivatives increased the sensitivity of analysis, which allowed the simultaneous detection of DNA adducts in a mixture.

9.
Environ Health Perspect ; 99: 191-3, 1993 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-8319622

RESUMEN

Current methodologies for the detection and isolation of carcinogen-DNA adducts have advanced beyond the capabilities of the methods used to elucidate their structures. This difficulty seriously limits the potential use of DNA-carcinogen adducts in human dosimetry. We have investigated two general strategies for the analysis of model arylamine-nucleoside adducts using desorption ionization mass spectrometry (MS). Using fast atom bombardment MS-MS with constant neutral loss scans, we can identify the protonated molecule of derivatized adducts in samples as small as 1 pmole, and then apply daughter ion MS-MS scans to obtain structure-specific fragmentation. Using this strategy we have differentiated adducts having the same carcinogen and different bases [e.g., N-(deoxyadenosin-8-yl)-4-aminobiphenyl and N-(deoxyguanosin-8-yl)-4- aminobiphenyl] or the same base and different carcinogens [e.g., N-(deoxyguanosin-8-yl)-4- aminobiphenyl and N-(deoxyguanosin-8-yl)-2-aminofluorene]. In the second approach we used laser desorption time-of-flight MS to obtain spectra from adduct samples as small as 20 fmole. These data indicate that MS can be used for the analysis of very low (picomole-femtomole) levels of nucleoside adducts, including isomers, and that desorption ionization MS and MS-MS have significant potential for applications in human dosimetry.


Asunto(s)
Carcinógenos/toxicidad , ADN/análisis , ADN/efectos de los fármacos , Espectrometría de Masa Bombardeada por Átomos Veloces/métodos , Carcinógenos/análisis , Daño del ADN , Estudios de Evaluación como Asunto , Humanos , Microquímica/métodos
10.
Environ Health Perspect ; 102 Suppl 6: 11-6, 1994 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-7889831

RESUMEN

Analysis of carcinogen-DNA adducts has been regarded as a useful means of assessing human exposure to chemical carcinogens. We have established a method for quantitation of 4-aminobiphenyl (4-ABP)-DNA adducts by alkaline hydrolysis and gas chromatography with negative ion chemical ionization mass spectrometry (GC-NICI-MS). Aliquots of DNA (typically 100 micrograms/ml) were spiked with an internal standard, d9-4-ABP, and were hydrolyzed in 0.05 N NaOH at 130 degrees C overnight. The liberated 4-ABP was extracted with hexane and derivatized using pentafluoropropionic anhydride in trimethylamine for 30 min at room temperature prior to GC-NICI-MS. With in vitro [3H]N-hydroxy-4-ABP modified DNA standards, we observed 59 +/- 7% (n = 9) recovery of the 4-ABP and a linear correlation between hydrolyzed 4-ABP and the adduct levels ranging from about 1 in 10(8) to 1 in 10(4) nucleotides (r = 0.999, n = 9). The method was further validated by comparison of the results with that obtained by the 32P-postlabeling method. There was excellent agreement (r = 0.994, p < 0.001) between the two methods for quantitation of the adduct in eight samples of Salmonella typhimurium DNA treated with 4-ABP and rat liver S9, although the 32P-postlabeling method gave slightly higher values. The DNA adducts in 11 human lung and 8 urinary bladder mucosa specimens were then determined by our GC-NICI-MS method. The adduct levels were found to be < 0.32 to 49.5 adducts per 10(8) nucleotides in the lungs and < 0.32 to 3.94 adducts per 10(8) nucleotides in the bladder samples.(ABSTRACT TRUNCATED AT 250 WORDS)


Asunto(s)
Compuestos de Aminobifenilo/análisis , Carcinógenos/análisis , Aductos de ADN/análisis , Pulmón/química , Vejiga Urinaria/química , Álcalis , Cromatografía de Gases y Espectrometría de Masas , Humanos , Hidrólisis , Reproducibilidad de los Resultados
11.
Environ Health Perspect ; 102 Suppl 6: 177-83, 1994 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-7889844

RESUMEN

We have been interested in the structure-activity relationships of nitro-polycyclic aromatic hydrocarbons (nitro-PAHs), and have focused on the correlation of structural and electronic features with biological activities, including mutagenicity and tumorigenicity. In our studies, we have emphasized 1-, 2-, 3-, and 6-nitrobenzo[a]pyrenes (nitro-B[a]Ps) and related compounds, all of which are derived from the potent carcinogen benzo[a]pyrene. While 1-, 2-, and 3-nitro-B[a]P are potent mutagens in Salmonella, 6-nitro-B[a]P is a weak mutagen. In vitro metabolism of 1- and 3-nitro-B[a]P has been found to generate multiple pathways for mutagenic activation. The formation of the corresponding trans-7,8-dihydrodiols and 7,8,9,10-tetrahydrotetrols suggests that 1- and 3-nitro-B[a]P trans-7,8-diol-9,10-epoxides are ultimate metabolites of the parent nitro-B[a]Ps. We have isolated a DNA adduct from the reaction between 3-nitro-B[a]P trans-7,8-diol-anti9,10-epoxide and calf thymus DNA, and identified it as 10-(deoxyguanosin-N2-yl)-7,8,9-trihydroxy-7,8,9,10-tetrahydro-3-ni tro-B[a]P . The same adduct was identified from in vitro metabolism of [3H]3-nitro-B[a]P by rat liver microsomes in the presence of calf thymus DNA. A DNA adduct of 3-nitro-B[a]P formed from reaction of N-hydroxy-3-amino-B[a]P, prepared in situ with calf thymus DNA was also isolated. This adduct was identified as 6-(deoxyguanosin-N2-yl)-3-amino-B[a]P. The same adduct was obtained from incubating DNA with 3-nitro-B[a]P in the presence of the mammalian nitroeductase, xanthine oxidase, and hypoxanthine.(ABSTRACT TRUNCATED AT 250 WORDS)


Asunto(s)
Carcinógenos/toxicidad , Aductos de ADN/biosíntesis , Mutágenos/toxicidad , Compuestos Policíclicos/toxicidad , Animales , Biotransformación , Carcinógenos/farmacocinética , Mutágenos/farmacocinética , Compuestos Policíclicos/farmacocinética , Salmonella typhimurium/genética , Estereoisomerismo , Relación Estructura-Actividad
12.
FEMS Microbiol Lett ; 177(1): 131-5, 1999 Aug 01.
Artículo en Inglés | MEDLINE | ID: mdl-10436931

RESUMEN

A strain of the saprobic fungus Mucor ramannianus, isolated from a forest, was used to demonstrate the potential for ciprofloxacin biotransformation by zygomycetes in the environment. The fungus carried out the regioselective N-acetylation of ciprofloxacin to a single product, which was purified from culture extracts by high-performance liquid chromatography. The metabolite was identified by mass and nuclear magnetic resonance spectrometry as 1-cyclopropyl-6-fluoro-1,4-dihydro-4-oxo-7-(4-acetyl-1-piperazinyl)-3- quinolinecarboxylic acid.


Asunto(s)
Ciprofloxacina/análogos & derivados , Ciprofloxacina/metabolismo , Mucor/metabolismo , Acetilación , Biotransformación , Cromatografía Líquida de Alta Presión , Espectroscopía de Resonancia Magnética , Estructura Molecular
13.
J Chromatogr A ; 888(1-2): 85-92, 2000 Aug 04.
Artículo en Inglés | MEDLINE | ID: mdl-10949475

RESUMEN

A RP-HPLC method with photodiode array detection and LC-electrospray ionization (ESI) MS confirmation was established for the determination of major active components in St. John's Wort dietary supplement capsules. The samples alternatively were extracted with ethanol-acetone (2:3) using a 55 degrees C water-bath shaker or an ambient temperature ultrasonic bath. Extracts were separated by RP-C18 chromatography using a 95-min water-methanol-acetonitrile-trifluoroacetic acid gradient. The major components were identified by photodiode array detection and then confirmed by LC-ESI-MS. The quantification of components was performed using an internal standard (luteolin). This method may serve as a valuable tool for the quality evaluation of St. John's Wort dietary supplement products.


Asunto(s)
Cromatografía Líquida de Alta Presión/métodos , Suplementos Dietéticos/análisis , Hypericum/química , Plantas Medicinales , Calibración , Reproducibilidad de los Resultados , Espectrometría de Masa por Ionización de Electrospray , Espectrofotometría Ultravioleta
14.
Mutat Res ; 378(1-2): 97-112, 1997 Aug 01.
Artículo en Inglés | MEDLINE | ID: mdl-9288889

RESUMEN

4-Aminobiphenyl (ABP) is a recognized human bladder carcinogen, whose presence in cigarette smoke results in DNA adduct formation in the human urothelium. Since preliminary studies indicated that even higher levels of ABP-DNA adducts may be present in human peripheral lung, we utilized a sensitive immunochemical assay, in combination with 32P-postlabeling, to quantify the major 4-aminobiphenyl (ABP)-DNA adduct, N-(guan-8-yl)-ABP, in surgical samples of peripheral lung tissue from smokers and ex-smokers. No differences in adduct levels were detected between smokers and ex-smokers by immunoassay. In contrast, the 32P-postlabeling method showed statistically significant differences between adduct levels in smokers and ex-smokers; however, a relatively high background of smoking-related adducts chromatograph near the major ABP adducts and may compromise estimation of the level of ABP-DNA adducts in smokers. Furthermore, the levels measured by 32P-postlabeling were 20- to 60-fold lower than that measured by immunoassay. Since 32P-postlabeling may underestimate and immunochemical assays may overestimate adduct levels in the lung, selected samples were also evaluated by GC/MS. The immunochemical and GC/MS data were concordant, leading us to conclude that N-(guan-8-yl)-ABP adducts were not related to smoking status. Since ABP-DNA adduct levels in human lung did not correlate with smoking status as measured by immunoassay and GC/MS, the metabolic activation capacity of human lung microsomes and cytosols was examined to determine if another exposure (e.g., 4-nitrobiphenyl) might be responsible for the adduct. The rates of microsomal ABP N-oxidation were below the limit of detection, which was consistent with a lack of detectable cytochrome P4501A2 in human lung. N-Hydroxy-ABP O-acetyltransferase (but not sulfotransferase) activity was detected in cytosols and comparative measurements of N-acetyltransferase (NAT) using p-aminobenzoic acid and sulfamethazine indicated that NAT1 and NAT2 contributed to this activity. 4-Nitrobiphenyl reductase activity was found in lung microsomes and cytosols, with the reaction yielding ABP and N-hydroxy-ABP. Lung microsomes also demonstrated high peroxidative activation of ABP, benzidine, 4,4'-methylene-bis(2-chloroaniline), 2-aminofluorene, and 2-naphthylamine. The preferred co-oxidant was hydrogen peroxide and the reaction was strongly inhibited by sodium azide but not by indomethacin or eicosatetraynoic acid, which suggested the primary involvement of myeloperoxidase rather than prostaglandin H synthase or lipoxygenase. This was confirmed by immunoinhibition and immunoprecipitation studies using solubilized human lung microsomes and antisera specific for myeloperoxidase. These data suggest that ABP-DNA adducts in human lung result from some environmental exposure to 4-nitrobiphenyl. The bioactivation pathways appear to involve: (1) metabolic reduction to N-hydroxy-ABP and subsequent O-acetylation by NAT1 and/or NAT2; and (2) metabolic reduction to ABP and subsequent peroxidation by myeloperoxidase. The myeloperoxidase activity appears to be the highest peroxidase activity measured in mammalian tissue and is consistent with the presence of neutrophils and polymorphonuclear leukocytes surrounding particulate matter derived from cigarette smoking.


Asunto(s)
Compuestos de Aminobifenilo/metabolismo , Carcinógenos/metabolismo , Aductos de ADN/análisis , Guanosina/análogos & derivados , Pulmón/metabolismo , Radioisótopos de Fósforo/metabolismo , Aciltransferasas/metabolismo , Bencidinas/metabolismo , Benzo(a)pireno/metabolismo , Biotransformación , Compuestos de Bifenilo/metabolismo , Citosol/metabolismo , Aductos de ADN/inmunología , Ensayo de Inmunoadsorción Enzimática , Cromatografía de Gases y Espectrometría de Masas , Guanosina/análisis , Humanos , Hígado/metabolismo , Pulmón/química , Microsomas/enzimología , Microsomas/metabolismo , Oxidación-Reducción , Peroxidasa/metabolismo , Peroxidasas/metabolismo , Fumar , Sulfotransferasas/metabolismo
15.
J Agric Food Chem ; 48(5): 1673-7, 2000 May.
Artículo en Inglés | MEDLINE | ID: mdl-10820077

RESUMEN

Improper application of antibiotic chemicals to livestock and aquaculture species may lead to the occurrence of residues in food supplies. An appropriate depletion period is needed after the administration of drugs to animals for ensuring that residues in edible tissues are below established tolerance levels. This study was conducted to determine incurred amoxicillin residues in catfish muscle following oral administration. Dosed fish were harvested after four depletion periods, and muscle fillets were analyzed for amoxicillin residues using an HPLC method with precolumn derivatization and fluorescence detection. The residue levels in fish after a 6-h depletion ranged from 40 to 64 ng/g with one exception at 297 ng/g. Average residue levels decreased to 5.4 and 2. 8 ng/g after 24- and 48-h depletions, respectively. Residue levels after a 72-h depletion decreased to below the method's limit of quantitation (1.2 ng/g). An LC-MS/MS confirmatory method was developed. Confirmation of the presence of amoxicillin was demonstrated in incurred fish samples containing residues at approximately 50-300 ng/g.


Asunto(s)
Amoxicilina/análisis , Cromatografía Líquida de Alta Presión/métodos , Residuos de Medicamentos/análisis , Músculos/química , Penicilinas/análisis , Administración Oral , Amoxicilina/administración & dosificación , Animales , Ictaluridae , Penicilinas/administración & dosificación , Espectrometría de Fluorescencia
16.
Adv Exp Med Biol ; 392: 93-103, 1996.
Artículo en Inglés | MEDLINE | ID: mdl-8850608

RESUMEN

A method is presented for determining the purity of the mycotoxin fumonisin B1 (FB1) by high performance liquid chromatography (HPLC) with evaporative light scattering detection (ELSD). The ELSD is a universal HPLC detector that exhibits a non-linear relationship between analyte amount and the resulting response. A log-log plot of ELSD response with the mass of FB1 injected was used as a calibration curve for determining the quantities of both FB1 and also individual impurities present in samples. Assumptions related to the uniformity of ELSD response for different but related compounds and other issues implied in this use of ELSD data were examined. One potential error produced by use of this method for purity analysis comes from the ELSD's decreased sensitivity for low-concentration analytes. Because analytes become more dilute the longer they remain on a chromatographic column, this sensitivity discrimination can be related to the retention times at which they appear. The ELSD response for FB1 at retention time 15.5 minutes was used to construct a general purpose calibration curve. Whenever a peak appeared at any time other than 15.5 minutes, the discrimination effect was corrected using a an empirically determined weighting factor and a proportion calculated from the retention time difference compared to 15.5 minutes. Purities for two fumonisin samples were calculated using both the ELSD method described above and an electrospray/mass spectrometric method. The quantitative assumptions underlying each method were discussed in order to understand and reconcile differences between the two sets of purity values obtained.


Asunto(s)
Carcinógenos Ambientales/análisis , Cromatografía Líquida de Alta Presión/métodos , Fumonisinas , Micotoxinas/análisis , Luz , Micotoxinas/aislamiento & purificación , Dispersión de Radiación
17.
J Anal Toxicol ; 14(4): 247-51, 1990.
Artículo en Inglés | MEDLINE | ID: mdl-1975634

RESUMEN

Elimination and metabolic profiles of the glucuronide products of doxylamine and its N-demethylated metabolites were determined after the oral administration of (14C)-doxylamine succinate (13.3 and 133 mg/kg doses) to male and female Fischer 344 rats. The cumulative urinary and fecal eliminations of these conjugated doxylamine metabolites at the 13.3 mg/kg dose were 44.4 +/- 4.2% and 47.3 +/- 8.1% of the total recovered dose for male and female rats, respectively. The cumulative urinary and fecal eliminations of conjugated doxylamine metabolites at the 133 mg/kg dose were 55.2 +/- 2.6% and 47.9 +/- 2.5% of the total recovered dose for male and female rats, respectively. The conjugated doxylamine metabolites that were isolated, quantitated, and identified are doxylamine O-glucuronide, N-desmethyl-doxylamine O-glucuronide, and N,N-didesmethyldoxylamine O-glucuronide.


Asunto(s)
Doxilamina/metabolismo , Heces/análisis , Antagonistas de los Receptores Histamínicos H1/metabolismo , Piridinas/metabolismo , Administración Oral , Animales , Cromatografía Líquida de Alta Presión , Doxilamina/administración & dosificación , Doxilamina/análogos & derivados , Doxilamina/orina , Femenino , Antagonistas de los Receptores Histamínicos H1/administración & dosificación , Antagonistas de los Receptores Histamínicos H1/orina , Masculino , Espectrometría de Masas/métodos , Estructura Molecular , Ratas , Ratas Endogámicas F344 , Factores Sexuales
18.
Mol Neurobiol ; 48(2): 363-7, 2013 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-23813100

RESUMEN

Dodecafluoropentane emulsion (DDFPe) in 250 nm nanodroplets seems to swell modestly to accept and carry large amounts of oxygen in the body at >29 °C. Small particle size allows oxygen delivery even into hypoxic tissue unreachable by erythrocytes. Using permanent cerebral embolic occlusion in rabbits, we assessed DDFPe dose response as a neuroprotectant at 7 and 24 h post-embolization without lysis of arterial obstructions and investigated blood pharmacokinetics. New Zealand White rabbits (N = 56) received cerebral angiography and embolic spheres (diameter = 700-900 µm) occluded middle and/or anterior cerebral arteries. Intravenous DDFPe dosing (2 % w/v emulsion) began at 60 min and repeated every 90 min until sacrifice at 7 or 24 h post-embolization. Seven-hour groups: (1) control (embolized without treatment, N = 6), and DDFPe treatment: (2) 0.1 ml/kg (N = 7), (3) 0.3 ml/kg (N = 9), (4) 0.6 ml/kg (N = 8). Twenty-four-hour groups: (5) control (N = 16), and DDFPe treatment: (6) 0.1 ml/kg (N = 10). Infarcts as percent of total brain volume were determined using vital stains on brain sections. Other alert normal rabbits (N = 8) received IV doses followed by rapid arterial blood sampling and GC-MS analysis. Percent infarct volume means significantly decreased for all DDFPe-treated groups compared with controls, p = <0.004 to <0.03. Blood DDFP (gas) half-life was 1.45 ± 0.17 min with R = 0.958. Mean blood clearance was 78.5 ± 24.9 ml/min/kg (mean ± SE). Intravenous DDFPe decreases ischemic stroke infarct volumes. Blood half-life values are very short. The much longer therapeutic effect, >90 min, suggests multiple compartments. Lowest effective dose and maximum effective therapy duration are not yet defined. Rapid development is warranted.


Asunto(s)
Infarto Cerebral/tratamiento farmacológico , Fluorocarburos/uso terapéutico , Fármacos Neuroprotectores/uso terapéutico , Accidente Cerebrovascular/tratamiento farmacológico , Animales , Encéfalo/efectos de los fármacos , Encéfalo/patología , Infarto Cerebral/patología , Modelos Animales de Enfermedad , Emulsiones , Fluorocarburos/sangre , Fluorocarburos/farmacología , Fármacos Neuroprotectores/farmacología , Conejos , Accidente Cerebrovascular/patología , Factores de Tiempo
19.
Curr Med Chem ; 18(1): 79-90, 2011.
Artículo en Inglés | MEDLINE | ID: mdl-21110813

RESUMEN

Globally, diabetes and obesity are two of the most common metabolic diseases of the 21(st) century. Increasingly, not only adults but children and adolescents are being affected. New approaches are needed to prevent and treat these disorders and to reduce the impact of associated disease-related complications. Industrial-scale production using plant-root cultures can produce quantities and quality of inexpensive bioactive small molecules with nutraceutical and pharmaceutical properties. Using this approach, and targeting these diseases, a next generation approach to tackling this emerging global health crisis may be developed. Adventitious roots cultured in bioreactors under controlled and reproducible conditions have been shown effective for production of natural products. The liquid-phase airlift bioreactor in particular has been used successfully for culturing roots on an industrial-scale and thus may provide an economical production platform for expressing promising plant-based antidiabetic and antioxidant molecules. This review focuses on a next-generation, scalable, bioprocessing approach for adventitious and hairy root cultures that are a pesticide-free, seasonally-independent, plant-based source of three molecules that have shown promise for the therapeutic management of diabetes and obesity: corosolic acid, resveratrol and ginsenosides.


Asunto(s)
Antioxidantes/metabolismo , Reactores Biológicos , Hipoglucemiantes/metabolismo , Antioxidantes/química , Antioxidantes/farmacología , Arachis/citología , Arachis/metabolismo , Biotecnología , Ginsenósidos/biosíntesis , Ginsenósidos/química , Ginsenósidos/farmacología , Hipoglucemiantes/química , Hipoglucemiantes/farmacología , Raíces de Plantas/citología , Raíces de Plantas/metabolismo , Resveratrol , Estilbenos/química , Estilbenos/farmacología , Triterpenos/química , Triterpenos/farmacología
SELECCIÓN DE REFERENCIAS
Detalles de la búsqueda