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1.
AJNR Am J Neuroradiol ; 43(10): 1437-1444, 2022 10.
Artigo em Inglês | MEDLINE | ID: mdl-36137654

RESUMO

BACKGROUND AND PURPOSE: MCA aneurysms are still commonly clipped surgically despite the recent development of a number of endovascular tools and techniques. We measured clinical uncertainty by studying the reliability of decisions made for patients with middle cerebral artery (MCA) aneurysms. MATERIALS AND METHODS: A portfolio of 60 MCA aneurysms was presented to surgical and endovascular specialists who were asked whether they considered surgery or endovascular treatment to be an option, whether they would consider recruitment of the patient in a randomized trial, and whether they would provide their final management recommendation. Agreement was studied using κ statistics. Intrarater reliability was assessed with the same, permuted portfolio of cases of MCA aneurysm sent to the same specialists 1 month later. RESULTS: Surgical management was the preferred option for neurosurgeons (n = 844/1320; [64%] responses/22 raters), while endovascular treatment was more commonly chosen by interventional neuroradiologists (1149/1500 [76.6%] responses/25 raters). Interrater agreement was only "slight" for all cases and all judges (κ = 0.094; 95% CI, 0.068-0.130). Agreement was no better within specialties or with more experience. On delayed requestioning, 11 of 35 raters (31%) disagreed with themselves on at least 20% of cases. Surgical management and endovascular treatment were always judged to be a treatment option, for all patients. Trial participation was offered to patients 65% of the time. CONCLUSIONS: Individual clinicians did not agree regarding the best management of patients with MCA aneurysms. A randomized trial comparing endovascular with surgical management of patients with MCA aneurysms is in order.


Assuntos
Embolização Terapêutica , Procedimentos Endovasculares , Aneurisma Intracraniano , Humanos , Tomada de Decisão Clínica , Reprodutibilidade dos Testes , Incerteza , Aneurisma Intracraniano/diagnóstico por imagem , Aneurisma Intracraniano/cirurgia , Procedimentos Neurocirúrgicos/métodos , Resultado do Tratamento , Estudos Retrospectivos
2.
Neuroradiology ; 64(12): 2363-2371, 2022 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-35695927

RESUMO

PURPOSE: The natural evolution of unruptured intracranial aneurysms (UIA) is indeed difficult to predict at the individual level. OBJECTIVE: In a large prospective multicentric European cohort, we aimed to evaluate whether the PHASES, UCAS, and ELPASS scores in patients with aneurysmal subarachnoid hemorrhage would have predicted a high risk of aneurysmal rupture or growth. METHODS: Academic centers treating patients with intracranial aneurysms were invited to prospectively collect de-identified data from all patients admitted at their institution for a subarachnoid hemorrhage-related to intracranial aneurysmal rupture between January 1 and March 31, 2021 through a trainee-led research collaborative network. Each responding center was provided with an electronic case record form (CRF) which collected all the elements of the PHASES, ELAPSS, and UCAS scores. RESULTS: A total of 319 patients with aneurysmal subarachnoid hemorrhage were included at 17 centers during a 3-month period. One hundred eighty-three aneurysms (57%) were less than 7 mm. The majority of aneurysms were located on the anterior communicating artery (n = 131, 41%). One hundred eighty-four patients (57%), 103 patients (32%), and 58 (18%) were classified as having a low risk of rupture or growth, according to the PHASES, UCAS, and ELAPSS scores, respectively. CONCLUSION: In a prospective study of European patients with aneurysmal subarachnoid hemorrhage, we showed that 3 common risk-assessment tools designed for patients with unruptured intracranial aneurysms would have not identified most patients to be at high or intermediate risk for rupture, questioning their use for decision-making in the setting of unruptured aneurysms.


Assuntos
Aneurisma Roto , Aneurisma Intracraniano , Hemorragia Subaracnóidea , Humanos , Hemorragia Subaracnóidea/diagnóstico por imagem , Aneurisma Intracraniano/complicações , Aneurisma Intracraniano/diagnóstico por imagem , Aneurisma Intracraniano/terapia , Estudos Prospectivos , Aneurisma Roto/diagnóstico por imagem , Fatores de Risco
3.
Eur J Neurol ; 27(10): 2031-2035, 2020 10.
Artigo em Inglês | MEDLINE | ID: mdl-32449311

RESUMO

BACKGROUND AND PURPOSE: It is currently unknown whether mechanical thrombectomy (MT) for ischaemic stroke patients with low initial Alberta Stroke Program Early Computed Tomography Score (ASPECTS) is clinically beneficial or even harmful. The purpose of this study was to investigate whether failed or incomplete MT in acute large vessel occlusion stroke with an initial ASPECTS ≤ 5 is associated with worse clinical outcome compared to patients not undergoing MT. METHODS: This observational cohort study included a consecutive sample of patients with anterior circulation stroke and initial ASPECTS ≤ 5 admitted between March 2015 and August 2019. Failed recanalization was defined as Thrombolysis in Cerebral Infarction (TICI) score 0-2a, and incomplete recanalization as TICI 2b. Clinical outcome was assessed using the modified Rankin Scale (mRS) at 90 days defining very poor clinical outcome as mRS > 4. RESULTS: One hundred and seventy patients were included. Ninety-nine patients underwent MT and 71 patients received best medical treatment only. Clinical outcome after failed or incomplete MT (TICI 0-2b) was significantly better compared to patients with medical treatment only (median mRS 5, interquartile range 4-6 vs 5-6, P = 0.03). In multivariable logistic regression analysis, failed or incomplete MT (TICI 0-2b) showed a significantly reduced likelihood for very poor outcome (odds ratio 0.39, 95% confidence interval 0.19-0.83, P = 0.01). Failed MT (TICI 0-2a) was not associated with a worse outcome compared to best medical treatment. CONCLUSIONS: Patients with failed or incomplete recanalization results (TICI 0-2b) showed a reduced likelihood for very poor outcome compared with those who did not receive MT. Evidence from randomized trials is needed to confirm that even failed or incomplete MT is not harmful in these patients.


Assuntos
Isquemia Encefálica , Acidente Vascular Cerebral , Alberta , Isquemia Encefálica/diagnóstico por imagem , Isquemia Encefálica/tratamento farmacológico , Isquemia Encefálica/cirurgia , Humanos , Estudos Retrospectivos , Acidente Vascular Cerebral/diagnóstico por imagem , Acidente Vascular Cerebral/tratamento farmacológico , Acidente Vascular Cerebral/cirurgia , Trombectomia , Resultado do Tratamento
4.
Clin Res Cardiol ; 108(10): 1147-1162, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-30868222

RESUMO

OBJECTIVES: As underlying heart diseases of right ventricular tachyarrhythmias, ARVC causes wall-motion abnormalities based on fibrofatty myocardial degeneration, while RVOT-VT and BrS are thought to lack phenotypic MR characteristics. To examine whether cardiac magnetic resonance (CMR) feature tracking (FT) in addition to ARVC objectively facilitates detection of myocardial functional impairments in RVOT-VT and BrS. METHODS: Cine MR datasets of four retrospectively enrolled, age-matched study groups [n = 65; 16 ARVC, 26 RVOT-VT, 9 BrS, 14 healthy volunteers (HV)] were independently assessed by two distinctly experienced investigators regarding myocardial function using CMR-FT. Global strain (%) and strainrate (s-1) in radial and longitudinal orientation were assessed at RVOT as well as for left (LV) and right (RV) ventricle at a basal, medial and apical section with the addition of a biventricular circumferential orientation. RESULTS: RV longitudinal and radial basal strain (%) in ARVC (- 12.9 ± 4.2; 11.4 ± 5.1) were significantly impaired compared to RVOT-VT (- 18.0 ± 2.5, p ≤ 0.005; 16.4 ± 5.2, p ≤ 0.05). Synergistically, RVOT endocardial radial strain (%) in ARVC (33.8 ± 22.7) was significantly lower (p ≤ 0.05) than in RVOT-VT (54.3 ± 14.5). For differentiation against BrS, RV basal and medial radial strain values (%) (13.3 ± 6.1; 11.8 ± 2.9) were significantly reduced when compared to HV (21.0 ± 6.9, p ≤ 0.05; 20.1 ± 6.6, p ≤ 0.005), even in case of a normal RV ejection fraction (EF) (> 45%; n = 6) (12.0 ± 2.7 vs. 20.1 ± 6.6, p ≤ 0.05). CONCLUSIONS: CMR-FT facilitates relevant differentiation in patients with right ventricular tachyarrhythmias: between ARVC against RVOT-VT and HV as well as between BrS with even a preserved EF against HV.


Assuntos
Displasia Arritmogênica Ventricular Direita/diagnóstico , Síndrome de Brugada/diagnóstico , Eletrocardiografia/métodos , Ventrículos do Coração/diagnóstico por imagem , Imagem Cinética por Ressonância Magnética/métodos , Contração Miocárdica/fisiologia , Disfunção Ventricular Direita/diagnóstico , Displasia Arritmogênica Ventricular Direita/fisiopatologia , Síndrome de Brugada/fisiopatologia , Diagnóstico Diferencial , Feminino , Seguimentos , Ventrículos do Coração/fisiopatologia , Humanos , Masculino , Pessoa de Meia-Idade , Miocárdio/patologia , Reprodutibilidade dos Testes , Estudos Retrospectivos , Disfunção Ventricular Direita/fisiopatologia
5.
Radiologe ; 58(9): 850-854, 2018 Sep.
Artigo em Alemão | MEDLINE | ID: mdl-29971452

RESUMO

PURPOSE: Headaches are a very common symptom and imaging is important to rule out symptomatic causes. For clinical differentiation between primary and secondary headaches an exact anamnesis and neurological examination are important. The aim of this study is therefore to identify anamnestic and neurological information that is associated with secondary headaches. Moreover, this study gives an overview of the causes and differential diagnoses of secondary headaches. METHODS: We performed a retrospective analysis of 239 patients ≥18 years with headaches who had undergone computed tomography or magnetic resonance imaging. The impact of basic characteristics such as age and gender as well as anamnestic (pain intensity, thromboembolic risk profile) and clinical information (neurological deficit, papilledema, reduced vigilance) was tested by χ2 test at the significance level p < 0.05. RESULTS: In all, 27 of the included patients (11.3%) showed intracranial pathologies that required treatment. The most frequent pathologies were intracranial hypertension (9 patients), cerebral mass lesions (7 patients) and thrombosis of the cranial sinus/veins (3 patients). There was a significant association of a pathologic imaging finding and neurological deficits (p = 0.001) and a papilledema (p < 0.001). Reduced vigilance, pain intensity and thromboembolic risk factors as well as age and gender showed no significant association. CONCLUSIONS: A neurological deficit and especially papilledema are hints towards secondary headaches and should result in computed tomography or magnetic resonance imaging. Other factors such as reduced vigilance, pain intensity, age and gender have no relevant impact on the occurrence of intracranial pathologies.


Assuntos
Cefaleia , Imageamento por Ressonância Magnética , Humanos , Exame Neurológico , Estudos Retrospectivos , Tomografia Computadorizada por Raios X
7.
Clin Neuroradiol ; 27(2): 193-197, 2017 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-26637183

RESUMO

BACKGROUND: The increasing use of endovascular treatments has led to higher recanalization rates and better clinical outcomes compared with intravenous thrombolysis alone. Stent retrievers represent the latest development for recanalization of large vessel occlusions. Decompressive hemicraniectomy has proved beneficial in patients suffering from rising intracranial pressure after malignant stroke. AIMS AND/OR HYPOTHESIS: We investigated the effect of the implementation of stent retriever treatment on the frequency of hemicraniectomy as a surrogate marker for infarct size and thus for poor neurological outcome. METHODS: Patients with acute ischemic stroke were retrospectively studied. We compared the frequency of hemicraniectomy following proximal artery occlusion of the internal carotid artery and middle cerebral artery main stem in the years before (2009 and 2010) and after (2012 and 2013) introducing stent retrievers. RESULTS: Overall, 497 patients with proximal arterial occlusion were included in the study. Of 253 patients admitted in the years 2009 and 2010 44 (17.4 %) and of 244 patients admitted in 2012 and 2013, 20 (8.2 %) received a hemicraniectomy. This decrease in the proportion of hemicraniectomies was statistically significant (p < 0.01). CONCLUSIONS: The findings in this study illustrate a significantly reduced rate of hemicraniectomies in patients with proximal artery occlusions after implementation of thrombectomy with stent retriever. Hereby, we could show a significant reduction of malignant infarctions after thrombectomy with stent retriever.


Assuntos
Infarto Cerebral/epidemiologia , Craniectomia Descompressiva/estatística & dados numéricos , Reoperação/estatística & dados numéricos , Stents/estatística & dados numéricos , Acidente Vascular Cerebral/epidemiologia , Acidente Vascular Cerebral/cirurgia , Trombectomia/estatística & dados numéricos , Adulto , Idoso , Idoso de 80 Anos ou mais , Infarto Cerebral/diagnóstico por imagem , Infarto Cerebral/cirurgia , Terapia Combinada/estatística & dados numéricos , Remoção de Dispositivo/instrumentação , Remoção de Dispositivo/estatística & dados numéricos , Alemanha/epidemiologia , Humanos , Masculino , Pessoa de Meia-Idade , Complicações Pós-Operatórias/etiologia , Complicações Pós-Operatórias/cirurgia , Estudos Retrospectivos , Fatores de Risco , Acidente Vascular Cerebral/diagnóstico por imagem , Trombectomia/instrumentação
8.
Rofo ; 188(5): 451-8, 2016 May.
Artigo em Inglês | MEDLINE | ID: mdl-26844423

RESUMO

PURPOSE: Intracranial hypotension has been reported as a complication of accidental drainage after surgical treatment in several cases. Application of negative pressure systems (wound drains, VAC(®)-therapy, chest tube drainage) had typically led to severe intracranial hypotension including intracranial hemorrhage and tonsillar herniation. In the last year the authors observed 2 cases of accidental spinal drainage of CSF in patients with neurological deficits, regressing after reduction of the device suction. MATERIAL AND METHODS: We conducted a systematic PubMed-based research of the literature to study the variety and frequency of the reported symptoms from 1st of January 1980 until 1st of October 2015. RESULTS: Reviewing the literature 24 relevant citations including 27 reported cases of posttraumatic or postoperative loss of CSF leading to neurological symptoms were identified. All 15 reported cases in which a negative pressure suction device had been applied showed severe neurological and radiological symptoms such as coma or brain herniation and intracranial hemorrhage. In all cases patients recovered rapidly after removal of the suction device. Milder symptoms were observed in the patients without negative pressure suction, mainly only presenting with headaches or cranial nerve involvement.Additionally, we give an overview about current recommendations regarding cranial and spinal imaging to rule out dural laceration and cranial hypotension. CONCLUSION: Patients with dural laceration complicated by accidental drainage of CSF can present with life-threatening conditions. Increasing use of negative pressure suction devices makes the reported condition an important differential diagnosis. A precise radiological examination can help to rule out dural laceration and intracranial hypotension. KEY POINTS: • Undetected dural laceration complicated by negative pressure suction drains can induce life-threatening symptoms.• Increasing use of negative pressure suction devices makes the reported condition an important differential diagnosis for radiologists Citation Format: • Sporns PB, Schwindt W, Cnyrim CD et al. Undetected Dural Leaks Complicated by Accidental Drainage of Cerebrospinal Fluid (CSF) can Lead to Severe Neurological Deficits. Fortschr Röntgenstr 2016; 188: 451 - 458.


Assuntos
Dano Encefálico Crônico/etiologia , Vazamento de Líquido Cefalorraquidiano/epidemiologia , Vazamento de Líquido Cefalorraquidiano/etiologia , Derivações do Líquido Cefalorraquidiano , Dura-Máter/lesões , Hipotensão Intracraniana/etiologia , Erros Médicos , Sucção/efeitos adversos , Dano Encefálico Crônico/epidemiologia , Estudos Transversais , Humanos , Hipotensão Intracraniana/epidemiologia , Cuidados Pós-Operatórios/efeitos adversos
12.
J Chem Ecol ; 31(12): 2761-73, 2005 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-16365703

RESUMO

A radial diffusion assay was employed to quantify condensed tannins (CT) in feed and feces of mule deer (Odocoileus hemionus) and white-tailed deer (O. virginianus). This biological assay measures the precipitation of bovine serum albumin (BSA), with the area of the precipitation ring being proportional to the amount of extracted CT applied to the well. CT extracted from the bark of white spruce (Picea glauca) was used as the standard. CT were extracted with 70% (v/v) aqueous acetone and precipitated with 50% (v/v) aqueous methanol or 70% (v/v) aqueous acetone. Functional range of CT weights for suitable ring measurement was 0.5-4.0 mg, and equilibrium was achieved within an incubation period of 24 hr. Methanol (50%) was a more effective precipitation solvent than acetone (70%) having 13 +/- 4% greater specific activity (P < 0.05) and superior capabilities for predicting CT content. Precipitation rings were evaluated on images magnified on a photocopier. Ring diameters measured on a 200% enlarged photocopy provided the most precise estimate of ring area (R2 = 0.98). This convenient method reduced analysis times and enhanced accuracy and precision of tannin quantification. Analytical consequences and future research requirements are considered.


Assuntos
Ração Animal/análise , Fezes/química , Taninos/isolamento & purificação , Animais , Cervos , Imunodifusão , Padrões de Referência , Reprodutibilidade dos Testes
13.
J Agric Food Chem ; 51(21): 6137-44, 2003 Oct 08.
Artigo em Inglês | MEDLINE | ID: mdl-14518935

RESUMO

Successful quantification of the glucose produced by enzyme hydrolysis of starch was achieved by a matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) protocol, using sorbitol as an internal standard. The starch contents measured by MALDI-TOF MS of corn starch, fiber-enriched oat flour derivatives, oat and barley flours, and barley flour/corn starch composites were evaluated in comparison to a widely accepted and validated method of starch determination, which relies on enzyme colorimetry (EC). The average starch content measured in a series of corn starch samples of different masses was 93 and 101% for EC and MALDI-TOF MS, respectively, values that represent the estimated purity of the sample. There was an agreement of 99% between the starch contents determined by the two analytical methods for complex flour-derived samples. Starch values estimated by MALDI-TOF MS consistently showed a greater degree of variability than those determined by EC, but this limitation was readily compensated by rapid acquisition of multiple mass spectra. This study is the first to report the quantification of glucose by MALDI-TOF MS, and it offers new perspectives into the potential utility of MALDI-TOF MS as a definitive tool for monosaccharide analysis and rapid starch determination in complex samples.


Assuntos
Colorimetria , Glucose/análise , Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por Matriz , Amido/análise , Avena/química , Farinha/análise , Glucana 1,4-alfa-Glucosidase/metabolismo , Hordeum/química , Hidrólise , Sorbitol/análise , Zea mays/química , alfa-Amilases/metabolismo
14.
J Agric Food Chem ; 51(18): 5367-75, 2003 Aug 27.
Artigo em Inglês | MEDLINE | ID: mdl-12926885

RESUMO

Sulfamethazine (SMT) and its major metabolite, N(4)-acetylsulfamethazine (NA-SMT), were each recovered from spiked water (0.1 ppb) and 10% (w/v) aqueous suspensions of soil (1 ppb) or composted manure (1 ppb), by using a three-stage solid phase immunoextraction (SPIE) system, followed by detection with matrix-assisted laser/desorption ionization time-of-flight mass spectrometry (MALDI-TOF MS). Sulfonamide recovery rates are reported for separate stages of the SPIE system and for trace-level sulfonamide SPIE extraction from the environmental samples. SPIE MALDI-TOF MS is a rapid and definitive technique with potentially better efficiency relative to other established trace-level sulfonamide analytical methods. SPIE MALDI-TOF MS required 1.5 h per batch (8-24 samples/batch) for sample enrichment, 5 min per batch for probe preparation, and 5 min per sample to acquire and process the spectrum. This is the first time MALDI-TOF MS has been reported as a potential means of detecting trace-level drug residues in complex environmental samples.


Assuntos
Anti-Infecciosos/análise , Resíduos de Drogas/análise , Poluentes Ambientais/análise , Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por Matriz , Sulfametazina/análise , Esterco/análise , Sensibilidade e Especificidade , Solo/análise , Sulfametazina/análogos & derivados , Água/análise
15.
J Agric Food Chem ; 49(7): 3335-40, 2001 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-11453772

RESUMO

Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) is a new technique that can be used to determine the molecular composition of polysorbate emulsifiers, which are commonly used as food additives. This is the first study to offer such a detailed examination of these heterogeneous compounds. MALDI-TOF MS is a powerful tool that can provide a polysorbate mass profile in less than two minutes. 2',4',6'-Trihydroxyacetophenone monohydrate was chosen to be an ideal matrix, as it easily facilitated desorption and ionization, provided good resolution, and allowed for fast and simple preparation of the sample. By addition of aqueous 0.01 M potassium chloride, species were resolved exclusively as potassium adducts in the positive ion mode. MALDI-TOF MS analysis before and after saponification indicated the presence of unbound ethylene oxide polymers, as well as free and esterified sorbitan- and sorbide-based species. Some evidence for the presence of disorbitan-based species was provided. Also illustrated were the polydispersity of the oxyethylene chains, the degree of esterification, and the identity of esterified fatty acids.


Assuntos
Aditivos Alimentares/análise , Polissorbatos/análise , Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por Matriz/métodos , Emulsões
16.
J Agric Food Chem ; 49(2): 543-8, 2001 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-11261989

RESUMO

A sample purification technique was developed for the detection of potato glycoalkaloids (GAs) in blood serum by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS). GAs were extracted from spiked serum (5 mL) using a C(18) solid-phase extraction cartridge. The GAs were then selectively captured on antibody-coated agarose beads. The agarose beads were washed with water and the GAs eluted with 25 microL of methanol. MALDI-TOF MS was used to detect the GAs in the methanol eluent. Immunoaffinity sample purification of the GAs effectively reduced the signal suppression observed during the analysis of unpurified samples. alpha-Chaconine and alpha-solanine were detected in serum spiked with 1 ng/mL of each GA.


Assuntos
Solanina/sangue , Animais , Anticorpos , Cromatografia de Afinidade/métodos , Feminino , Coelhos , Sensibilidade e Especificidade , Solanina/análogos & derivados , Solanina/isolamento & purificação , Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por Matriz/métodos
17.
J Agric Food Chem ; 48(9): 4079-82, 2000 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-10995317

RESUMO

Glycoalkaloids (GAs) occur naturally in potatoes and are toxic to humans and animals. The objective of the present study was to evaluate the performance of a solution-phase immunoassay coupled to capillary electrophoresis with laser-induced fluorescence (CE-LIF) detection for the determination of total glycoalkaloids in potatoes. The immunoassay was based on a competition between potato glycoalkaloids and fluorescently labeled solanidine. Reaction products were separated in the capillary zone electrophoresis mode. A calibration curve of signal vs log[GA] was linear from 50 to 400 nM. The CV for duplicate and day-to-day analyses averaged 5.7% and 12%, respectively. Spike recoveries ranged from 85 to 97% for spike levels ranging from 43 to 170 microg/g fresh potato. Potato samples with GA concentrations ranging from <40 to >200 microg/g were successfully analyzed, indicating that immuno-CE-LIF is a rapid alternative to traditional ELISA and HPLC methods.


Assuntos
Alcaloides/análise , Eletroforese Capilar/métodos , Solanum tuberosum/química , Espectrometria de Fluorescência/métodos , Estudos de Avaliação como Assunto , Imunoensaio , Lasers , Soluções
18.
J Agric Food Chem ; 48(8): 3330-5, 2000 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-10956111

RESUMO

High-performance liquid chromatography (HPLC) has been widely used as a reliable technique to quantify anthocyanins in food samples. Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) is a new technique that is having a great impact on food analysis. This study is the first to compare HPLC and MALDI-TOF MS quantifications of anthocyanins. The analyses were carried out for highbush blueberries at different stages of anthocyanin formation. In general, both techniques provided comparable quantitative anthocyanin profiles for the samples. HPLC could distinguish anthocyanin isomers, whereas MALDI-TOF MS proved to be more rapid in the accurate identification and quantification of anthocyanins with different masses. A single MALDI-TOF MS run took just 4 min. MALDI-TOF MS analysis can serve as a rapid alternative to HPLC for the analysis of anthocyanins in fruits.


Assuntos
Antocianinas/análise , Cromatografia Líquida de Alta Pressão/métodos , Frutas/química , Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por Matriz/métodos
19.
J Agric Food Chem ; 48(7): 2807-11, 2000 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-10898626

RESUMO

Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) is a relatively new technique that is having a great impact on analyses. This study is the first to demonstrate the use of linear MALDI-TOF MS to identify and quantify coccidiostats in poultry feeds. 2,5-Dihydroxybenzoic acid (DHB) was found to be the best matrix. In MALDI-TOF MS, coccidiostats form predominantly [M + Na](+) ions, with additional small amounts of [M + K](+) and [M - H + 2Na](+) ions, and no obvious fragment ions. Salinomycin and narasin were unstable in the concentrated DHB matrix solution but were stable when dried on the MALDI-TOF MS probe. A simple fast Sep-pak C18 cartridge purification procedure was developed for the MALDI-TOF MS quantification of coccidiostats in poultry feeds. The MALDI-TOF MS limit of detection for lasalocid, monensin, salinomycin, and narasin standards was 251, 22, 24, and 24 fmol, respectively. The method detection limit for salinomycin and narasin in poultry feeds was 2.4 microgram/g.


Assuntos
Ração Animal/análise , Coccidiostáticos/análise , Animais , Galinhas , Modelos Químicos , Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por Matriz
20.
J Agric Food Chem ; 48(5): 1657-62, 2000 May.
Artigo em Inglês | MEDLINE | ID: mdl-10820074

RESUMO

Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) is a new technique that is having a great impact on food analysis. This study is the first to demonstrate the use of MALDI-TOF MS to identify flavonol glycosides in food samples. 2',4',6'-Trihydroxyacetophenone was chosen as the best matrix because it worked for crude sample extracts and ionized flavonol glycosides in both positive and negative MALDI-TOF MS modes. In the positive mode, multiple ion forms were observed for flavonol glycosides, including [M + H](+), [M + Na](+), [M + K](+), and [M - H + Na + K](+), with further fragmentation through loss of glycosidic residues. The negative mode for all flavonol glycosides resulted in [M - H](-) ion formation without detectable fragmentation. The multiple ions in the positive mode gave more information on individual flavonol glycoside structures than the negative mode. Flavonol glycosides showed similar intensities or responses in the positive mode, while kaempferol glycosides exhibited much less response than quercetin glycosides in negative mode.


Assuntos
Flavonoides/química , Análise de Alimentos , Glicosídeos/análise , Flavonóis , Glicosídeos/química , Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por Matriz
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