Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 10 de 10
Filter
Add more filters










Publication year range
1.
J Chromatogr A ; 1429: 53-64, 2016 Jan 15.
Article in English | MEDLINE | ID: mdl-26718187

ABSTRACT

A novel molecularly imprinted solid phase extraction (MISPE) methodology followed by liquid chromatography tandem mass spectrometry (LC-MS/MS) has been developed using cylindrical shaped molecularly imprinted pills for detection of Δ(9)-tetrahydrocannabinol (THC), 11-nor-Δ(9)-tetrahydrocannabinol carboxylic acid (THC-COOH), cannabinol (CBN) and cannabidiol (CBD) in urine and oral fluid (OF). The composition of the molecular imprinted polymer (MIP) was optimized based on the screening results of a non-imprinted polymer library (NIP-library). Thus, acrylamide as functional monomer and ethylene glycol dimethacrylate as cross-linker were selected for the preparation of the MIP, using catechin as a mimic template. MISPE pills were incubated with 0.5 mL urine or OF sample for adsorption of analytes. For desorption, the pills were transferred to a vial with 2 mL of methanol:acetic acid (4:1) and sonicated for 15 min. The elution solvent was evaporated and reconstituted in methanol:formic acid (0.1%) 50:50 to inject in LC-MS/MS. The developed method was linear over the range from 1 to 500 ng mL(-1) in urine and from 0.75 to 500 ng mL(-1) in OF for all four analytes. Intra- and inter-day imprecision were <15%. Extraction recovery was 50-111%, process efficiency 15.4-54.5% and matrix effect ranged from -78.0 to -6.1%. Finally, the optimized and validated method was applied to 4 urine and 5 OF specimens. This is the first method for the determination of THC, THC-COOH, CBN and CBD in urine and OF using MISPE technology.


Subject(s)
Body Fluids/chemistry , Cannabinoids/analysis , Chemistry Techniques, Analytical/instrumentation , Chemistry Techniques, Analytical/methods , Water , Chromatography, Liquid , Dronabinol/analysis , Humans , Methacrylates/chemistry , Polymers/chemistry , Saliva/chemistry , Solid Phase Extraction , Solvents/chemistry , Tandem Mass Spectrometry , Urine/chemistry
2.
JAMA Ophthalmol ; 131(7): 933-6, 2013 Jul.
Article in English | MEDLINE | ID: mdl-23700141

ABSTRACT

In 1585, the renowned French royal surgeon Jacques Guillemeau published his Traité des maladies de l'oeil. The book is divided into 9 unequal sections devoted to the description of eye anatomy and ophthalmological diseases including muscle, membrane, and humor disorders; optic nerve damage; and eyelid affections. Section 3, in particular, focuses on a form of ophthalmoplegia involving progressive paralysis of extraocular muscles. Here we describe and discuss Guillemeau's theoretical framework and practical approach to this ophthalmological disorder. To determine whether this physician was possibly influenced by the thought of antique and contemporary learned men, we reviewed some fundamental ideas on cranial nerves and their paralysis as presented by authors such as Herophilus of Chalcedon, Erasistratus of Ceos, Claudius Galen, Andreas Vesalius, and Leonhard Fuchs.


Subject(s)
Ophthalmoplegia/history , France , History, 16th Century , Humans , Ophthalmology/history
3.
Bol. latinoam. Caribe plantas med. aromát ; 12(3): 302-312, mayo 2013. ilus
Article in English | LILACS | ID: lil-723576

ABSTRACT

We studied antioxidant, antibacterial and tripanocide activities of Alvaradoa subovata extracts. The ethanolic extracts showed the greatest DPPH radical scavenging capacity, especially that of bark with an IC50 = 4.7 +/- 0.18 ug/mL. Wood dichloromethane extract displayed growth inhibition of the phytopathogenic bacteria Xanthomona axonopodis in the disk diffusion assay and showed a MIC value of 100 ug/ml. It also showed growth inhibition of Trypanosoma cruzi (IC50 = 0.063 +/- 0.003 mg/mL). A fraction of this extract, which has emodin as the main component, showed tripanocide activity (60 percent of growth inhibition at 100 ug/mL). The main compounds in wood dichloromethane extract were anthraquinones, identified as chrysophanol and emodin, and coumarins, of which scopoletin was identified. These three compound s could serve as analytical markers of the extract. The results of this study show that wood extract of A. subovata constitute a source of bioactive compounds such as antiparasitic and pesticides agents.


En el presente trabajo se estudió la actividad antioxidante, antibacteriana y tripanocida de extractos de Alvaradoa subovata. La mayor actividad depuradora de radicales libres se observó en el extracto etanólico de corteza (CI50 = 4.7 +/- 0.18 ug/mL). El extracto en diclorometano de madera inhibió el crecimiento de la bacteria fitopatógena Xanthomona axonopodis con una CIM = 100 ug/mL. El mismo extracto mostró inhibición del crecimiento de Trypanosoma cruzi (CI50 = 0.063 +/- 0.003 mg/mL). Una fracción de este extracto (100 ug/mL), cuyo componente mayoritario es emodina, inhibió en un 60 por ciento el crecimiento del parásito. Los compuestos mayoritarios detectados en el extracto de madera fueron antraquinonas, entre las cuales se identificaron emodina y crisofanol, y la cumarina escopoletina. Estos tres compuestos podrían servir como marcadores analíticos del extracto. Los resultados de este trabajo muestran que los extractos de A. subovata constituyen una fuente de compuestos bioactivos con potencial como antiparasitarios y plaguicidas.


Subject(s)
Anti-Bacterial Agents/pharmacology , Plant Extracts/pharmacology , Simaroubaceae/chemistry , Trypanocidal Agents/pharmacology , Antioxidants/pharmacology , Biphenyl Compounds/chemistry , Free Radical Scavengers , Microbial Sensitivity Tests , Picrates/chemistry , Xanthomonas
4.
ACS Appl Mater Interfaces ; 5(8): 3281-9, 2013 Apr 24.
Article in English | MEDLINE | ID: mdl-23537090

ABSTRACT

In this paper, investigations were carried out on catechin-loaded maleic anhydride (MAH)-modified polypropylenes (PP). Two maleic-modified polypropylenes (PPMAH) with different maleic concentrations have been blended with PP and catechin to obtain composites of improved catechin retention with the aim of studying the possible interactions between these grafted polymers with antioxidants, and a secondary interest in developing an active antioxidant packaging. Composite physicochemical properties were measured by thermal analysis (thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), and oxidation induction time (OIT)) and infrared spectroscopy studies. Catechin release profiles into food simulants were obtained by HPLC-PDA-QqQ, following European legislation. Antiradical activity of composites was analyzed by the ABTS and DPPH method. The formation of intermolecular hydrogen bonds between catechin and functionalized PP has been confirmed by Fourier transform infrared (FTIR) studies. Besides, a small fraction of ester bonds, formed as a result of a chemical reaction between a fraction of the hydrolyzed anhydride and the catechin hydroxyl groups, is not discarded. OIT results also showed an increase in antioxidant effectiveness caused by the presence of catechin- and maleic-modified PPMAH in the blend formulations. Incorporation of MAH-grafted PP increased substantially the retention rate of catechin, being dependent on the MAH content of the grafted polypropylene. The described interactions between catechin and maleic groups, together with changes in PP morphology in comparison with reference PP explained lower antioxidant release. Besides formulation, antioxidant release was dependent on the type of food, the temperature, and the time.


Subject(s)
Catechin/chemistry , Food Packaging/instrumentation , Maleic Anhydrides/chemistry , Polymers/chemistry , Polypropylenes/chemistry , Kinetics
5.
J Sep Sci ; 33(22): 3595-603, 2010 Nov.
Article in English | MEDLINE | ID: mdl-20931612

ABSTRACT

This article investigates the applicability of HPLC-UV, ultra performance LC-evaporative light-scattering detection (UPLC-ELSD), HPLC-ESI(+)-MS and HPLC-hybrid linear ion trap (LTQ) Orbitrap MS for the analysis of different non-ionic antistatic additives, Span 20, Span 60, Span 65, Span 80, Span 85 (sorbitan fatty acid esters), Atmer 129 (glycerol fatty acid ester) and Atmer 163 (ethoxylated alkylamine). Several alkyl chain length or different degrees of esterification of polyol derivatives can be present in commercial mixtures of these polymer additives. Therefore, their identification and quantification is complicated. Qualitative composition of the studied compounds was analysed by MS. HPLC-UV, UPLC-ELSD and HPLC-LTQ Orbitrap MS methods were applied to the quantitative determination of the different Spans, Atmer 129 and Atmer 163, respectively. Quality parameters of these methods were established and no derivatization was necessary.

6.
J Sep Sci ; 33(17-18): 2698-706, 2010 Sep.
Article in English | MEDLINE | ID: mdl-20665765

ABSTRACT

A chromatographic method using ultra performance LC with ultraviolet spectrophotometry detection system (UPLC-UV-visible (UV/Vis)) (UPLC, ultra performance LC) was developed to determine Chimassorb 944 and Tinuvin 770, high- and low-molecular mass hindered amine light stabilizers, respectively. The use of a bridge ethylene hybrid-based particles C(18) UPLC column, being compatible with a buffered mobile phase adjusted to pH 11.5, was used to achieve a satisfactory elution of possible non-ionizated units of polymeric Chimassorb 944. In addition, a HPLC with positive ion mode ESI and hybrid linear ion trap (LTQ) Fourier transform (FT) Orbitrap MS detection system (HPLC-UV/Vis-ESI-LTQ(FT)Orbitrap) was used for screening and identification purposes. Reliable determinations of monomeric units of Chimassorb 944 and molecule of Tinuvin 770 were achieved by HPLC-ESI(+)-LTQ FT Orbitrap MS method using scan mode. Quality parameters of UPLC-UV/Vis method were evaluated. Obtained LODs and LOQs were 3.41 and 11.4 mg/L for Tinuvin 770 and 0.83 and 2.78 mg/L for Chimassorb 944, respectively. Satisfactory quality parameters of this chromatography method provided the chance to count on a good tool to know the compliance with legal requirements.

7.
Rev Chilena Infectol ; 26(6): 511-4, 2009 Dec.
Article in Spanish | MEDLINE | ID: mdl-20098784

ABSTRACT

Campylobacter jejuni is a common agent of enterocolitis in humans. Campylobacteriosis has been recognized as a zoonotic disease whose reservoir is the intestinal flora of poultry. The reposition of fluid and electrolytes is the recommended treatment, and antimicrobials are required only in severe and/or in prolonged disease. Given the emergence of resistance to drugs commonly used in the treatment of acute diarrhea, we studied the antimicrobial susceptibility of 73 strains of Campylobacter jejuni isolated from stool culture. The antimicrobials tested were: erythromycin, azithromycin, ampicillin and ciprofloxacin. Of the 73 strains tested by E-test, 32.4% were resistant to ciprofloxacin and 6.4% were resistant to ampicillin. Resistance to erythromycin and azithromycin was not detected. The surveillance of antimicrobial resistance of Campylobacter jejuni is important in the evaluation of empirically used antimicrobials in the treatment of bacterial enterocolitis.


Subject(s)
Anti-Bacterial Agents/pharmacology , Campylobacter jejuni/drug effects , Feces/microbiology , Adolescent , Adult , Aged , Campylobacter Infections/microbiology , Child , Chile , Humans , Microbial Sensitivity Tests , Middle Aged , Prospective Studies , Young Adult
8.
J Sep Sci ; 30(15): 2452-9, 2007 Oct.
Article in English | MEDLINE | ID: mdl-17722192

ABSTRACT

An analytical method for the simultaneous separation and quantitation of ten colorants and six antioxidants used as polymer additives has been developed by transferring chromatographic conditions from two independent HPLC methods to a single ultraperformance liquid chromatography system. An experimental design was carried out to achieve the best elution gradient for separation of all the studied compounds with the best possible peak resolution and in the shortest possible analysis time. The new method gives good values for the analytical quality parameters evaluated.

9.
Cardiology ; 104(1): 45-50, 2005.
Article in English | MEDLINE | ID: mdl-15942174

ABSTRACT

BACKGROUND: In patients with acute coronary syndrome (ACS), the prevalence of a primary inflammatory pathogenic component of coronary instability, as detectable by elevated C-reactive protein (CRP), varies considerably. The aim of the present study was to assess the prevalence of inflammation in patients with ACS according to the different electrocardiographic (ECG) patterns on admission. METHODS: Hundred and thirty-six consecutive patients with the diagnosis of acute myocardial infarction were divided in three groups according to the ECG pattern on admission. Group 1 included 59 patients with ST segment elevation, group 2 included 50 patients with ST depression and/or T wave inversion and group 3 included 27 patients with no ECG changes. CRP was measured on admission in all patients. For the prevalence of inflammation analysis, we used a cutoff value of 3 mg/l. RESULTS: CRP was above cutpoint significantly more often in patients with ST depression and/or T wave inversion (44.1% in group 1, 70% in group 2 and 40.7% in group 3; p=0.009). Patients with similar ECG pattern and CRP levels above the cutpoint presented a poorer outcome (coronary death, myocardial infarction and recurrence of instability) at one-year follow-up: 54 versus 27% for group 1, 74 versus 27% for group 2 and 45 versus 31% for group 3. CONCLUSIONS: Patients with ST depression and/or T wave inversion on admission exhibit a higher prevalence of elevated CRP than those with ST elevation or no ECG changes, suggesting an important heterogeneity of the role of inflammatory triggers of the clinical syndromes of coronary instability.


Subject(s)
C-Reactive Protein/analysis , Electrocardiography , Myocardial Infarction/physiopathology , Aged , Female , Humans , Inflammation , Male , Myocardial Infarction/blood , Prognosis
10.
J Agric Food Chem ; 52(21): 6414-7, 2004 Oct 20.
Article in English | MEDLINE | ID: mdl-15479000

ABSTRACT

The antifungal activity of the essential oil of the aerial parts of Bupleurum gibraltarium was evaluated against Plasmopara halstedii. Fungus spores were inoculated in sunflower seedlings, previously treated with several essential oil solutions, and the sporulation percentage was measured after an 11-day treatment. The oil at a concentration of 5.0 mL/L clearly inhibited the fungus sporulation. The contact between fungus sporangia and essential oil was minimized, so it seems that the oil pretreatment could activate the defense response of the sunflower seedlings against the pathogen invasion. The main compounds in the oil were sabinene (31.1%), alpha-pinene (15.6%), and 2,3,4-trimethylbenzaldehyde (10.9%), among a total of 65 components identified.


Subject(s)
Bupleurum/chemistry , Fungi/drug effects , Fungicides, Industrial/pharmacology , Helianthus/microbiology , Oils, Volatile/pharmacology , Oomycetes/drug effects
SELECTION OF CITATIONS
SEARCH DETAIL
...