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1.
Spinal Cord ; 61(10): 548-555, 2023 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-37749189

RESUMO

STUDY DESIGN: Multicentre, cross-sectional study. OBJECTIVES: To determine if clinical measures of poor mental health (MH-) and neuropathic pain (NP) are related to increased CVD risk in individuals with chronic spinal cord injury (SCI), and further elucidate the relationships between CVD risk, autonomic function, NP, and MH-. SETTING: Eight SCI rehabilitation centres in the Netherlands. METHODS: Individuals (n = 257) with a traumatic, chronic (≥10 yrs) SCI, with age at injury between 18-35 years, completed a self-report questionnaire and a one-day visit to a rehabilitation centre for testing. CVD risk was calculated using Framingham risk score. NP was inferred using The Douleur Neuropathique 4 clinical examination, and MH- was assessed using the five-item Mental Health Inventory questionnaire. Cardiovascular autonomic function was determined from peak heart rate during maximal exercise (HRpeak). RESULTS: There was a high prevalence of both NP (39%) and MH- (45%) following SCI. MH- was significantly correlated with an adverse CVD risk profile (r = 0.174; p = 0.01), increased the odds of adverse 30-year CVD risk by 2.2 (CI 0.92-2.81, p = 0.02), and is an important variable in determining CVD risk (importance=0.74, p = 0.05). Females (p = 0.05) and those with a higher HRpeak (p = 0.046) tended to be more likely to have NP. CONCLUSIONS: Clinical measures of MH-, but not NP, are important factors for increased CVD risk following SCI. NP tended to be more prevalent in those with more preserved cardiovascular autonomic function. The interrelationships between secondary consequences of SCI are complex and need further exploration.


Assuntos
Doenças Cardiovasculares , Neuralgia , Traumatismos da Medula Espinal , Feminino , Humanos , Recém-Nascido , Traumatismos da Medula Espinal/complicações , Traumatismos da Medula Espinal/epidemiologia , Saúde Mental , Doenças Cardiovasculares/etiologia , Doenças Cardiovasculares/complicações , Estudos Transversais , Neuralgia/complicações
2.
Spinal Cord ; 59(7): 716-729, 2021 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-33070157

RESUMO

STUDY DESIGN: Multicentre, cross-sectional study. OBJECTIVES: To identify which markers of obesity, injury characteristics and autonomic function variables are related to cardiovascular disease (CVD) risk after spinal cord injury (SCI), and establish cut-points for detection and risk management. SETTING: Eight SCI rehabilitation centres in the Netherlands. METHODS: Individuals (n = 257) with a traumatic, chronic (≥10 years) SCI, with age at injury between 18 and 35 years, completed a self-report questionnaire and a one-day visit to a rehabilitation centre for testing. Three anthropometric measures were tested: body mass index (BMI); waist circumference (WC); and waist-to-height ratio (WHtR). Injury characteristics included: American Spinal Injury Association impairment scale (AIS); duration of injury (DOI); and neurological level of injury (LOI). Cardiovascular autonomic function was assessed from peak heart rate during maximal exercise (HRpeak). Systolic arterial pressure (SAP) and aerobic capacity (VO2peak) were also determined. CVD risk was calculated using the Framingham risk score (FRS). RESULTS: All anthropometric variables were associated with FRS, with WC showing the strongest correlation (r = 0.41, p < 0.001) and greatest area under the curve (0.73) for 10-year CVD risk (%). WC, DOI, SAP, HRpeak, LOI, and VO2peak (variable importance: 0.81, 1.0, 0.98, 0.98, 0.66, 0.68, respectively) were important predictive variables for 10-year CVD risk in individuals with SCI. CONCLUSIONS: We confirm that WC is a simple, practical measure of CVD risk, and along with DOI and markers of cardiovascular autonomic function, plays a role in the increased CVD risk following SCI.


Assuntos
Doenças Cardiovasculares , Traumatismos da Medula Espinal , Adolescente , Adulto , Índice de Massa Corporal , Doenças Cardiovasculares/diagnóstico , Doenças Cardiovasculares/epidemiologia , Doenças Cardiovasculares/etiologia , Estudos Transversais , Humanos , Fatores de Risco , Traumatismos da Medula Espinal/complicações , Traumatismos da Medula Espinal/diagnóstico , Traumatismos da Medula Espinal/epidemiologia , Circunferência da Cintura , Adulto Jovem
3.
Neuroimage ; 210: 116551, 2020 04 15.
Artigo em Inglês | MEDLINE | ID: mdl-31978542

RESUMO

PURPOSE: Based on a deep learning neural network (NN) algorithm, a super fast and easy to implement data analysis method was proposed for myelin water imaging (MWI) to calculate the myelin water fraction (MWF). METHODS: A NN was constructed and trained on MWI data acquired by a 32-echo 3D gradient and spin echo (GRASE) sequence. Ground truth labels were created by regularized non-negative least squares (NNLS) with stimulated echo corrections. Voxel-wise GRASE data from 5 brains (4 healthy, 1 multiple sclerosis (MS)) were used for NN training. The trained NN was tested on 2 healthy brains, 1 MS brain with segmented lesions, 1 healthy spinal cord, and 1 healthy brain acquired from a different scanner. RESULTS: Production of whole brain MWF maps in approximately 33 â€‹s can be achieved by a trained NN without graphics card acceleration. For all testing regions, no visual differences between NN and NNLS MWF maps were observed, and no obvious regional biases were found. Quantitatively, all voxels exhibited excellent agreement between NN and NNLS (all R2>0.98, p â€‹< â€‹0.001, mean absolute error <0.01). CONCLUSION: The time for accurate MWF calculation can be dramatically reduced to less than 1 â€‹min by the proposed NN, addressing one of the barriers facing future clinical feasibility of MWI.


Assuntos
Água Corporal/diagnóstico por imagem , Encéfalo/diagnóstico por imagem , Aprendizado Profundo , Imageamento por Ressonância Magnética/métodos , Esclerose Múltipla/diagnóstico por imagem , Bainha de Mielina , Neuroimagem/métodos , Adulto , Estudos de Viabilidade , Feminino , Humanos , Masculino , Pessoa de Meia-Idade
4.
Spinal Cord ; 58(9): 980-987, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-32371940

RESUMO

STUDY DESIGN: Multicenter prospective cohort. OBJECTIVE: To discern neurological- and functional recovery in patients with a traumatic thoracic spinal cord injury (TSCI), conus medullaris syndrome (CMS), and cauda equina syndrome (CES). SETTING: Specialized spinal cord injury centers in Europe. METHOD: Lower extremity motor score (LEMS) and spinal cord independent measure (SCIM) scores from patients with traumatic TSCI, CMS, and CES were extracted from the EMSCI database. Scores from admittance and during rehabilitation at 1, 3, 6, and 12 months were compared. Linear mixed models were used to statistically analyse differences in outcome, which were corrected for the ASIA Impairment Scale (AIS) in the acute phase. RESULTS: Data from 1573 individuals were analysed. Except for the LEMS in patients with a CES AIS A, LEMS, and SCIM significantly improved over time for patients with a TSCI, CMS, and CES. Irrespectively of the AIS score, recovery in 12 months after trauma as measured by the LEMS showed a statistically significant difference between patients with a TSCI, CMS, and CES. Analysis of SCIM score showed no difference between patients with TSCI, CMS, or CES. CONCLUSION: Difference in recovery between patients with a traumatic paraplegia is based on neurological (motor) recovery. Regardless the ceiling effect in CES patients, patients with a mixed upper and lower motor neuron syndrome (CMS) showed a better recovery compared with patients with a upper motor neuron syndrome (TSCI). These findings enable stratifications of patients with paraplegia according to the level and severity of SCI.


Assuntos
Síndrome da Cauda Equina/fisiopatologia , Doença dos Neurônios Motores/fisiopatologia , Avaliação de Resultados em Cuidados de Saúde , Paraplegia/fisiopatologia , Recuperação de Função Fisiológica/fisiologia , Compressão da Medula Espinal/fisiopatologia , Traumatismos da Medula Espinal/fisiopatologia , Adulto , Síndrome da Cauda Equina/etiologia , Síndrome da Cauda Equina/reabilitação , Europa (Continente) , Feminino , Humanos , Vértebras Lombares/lesões , Masculino , Pessoa de Meia-Idade , Doença dos Neurônios Motores/etiologia , Doença dos Neurônios Motores/reabilitação , Paraplegia/etiologia , Paraplegia/reabilitação , Estudos Prospectivos , Compressão da Medula Espinal/etiologia , Compressão da Medula Espinal/reabilitação , Traumatismos da Medula Espinal/complicações , Traumatismos da Medula Espinal/reabilitação , Vértebras Torácicas/lesões
5.
Health Rep ; 29(3): 11-16, 2018 Mar 21.
Artigo em Inglês | MEDLINE | ID: mdl-29561565

RESUMO

BACKGROUND: The prevalence of pain among people with a variety of individual neurological conditions has been estimated. However, information is limited about chronic pain among people with neurological conditions overall, and about the conditions for which chronic pain is most prevalent. To fill these information gaps, a common method of pain assessment is required. DATA AND METHODS: The data are from the Survey on Living with Neurological Conditions in Canada, a cross-sectional national survey. Based on self-reports, chronic pain was assessed for 16 neurological conditions. Multivariable logistic regression was used to produce odds ratios and 95% confidence intervals (CIs). RESULTS: Close to 1.5 million individuals aged 15 or older who lived in private households reported having been diagnosed with a neurological condition. The overall prevalence of chronic pain for the 16 neurological conditions combined was 36% (95% CI: 31% to 42%). The odds of chronic pain were significantly elevated among individuals with spinal cord trauma. DISCUSSION: Chronic pain is highly prevalent among people with neurological conditions, particularly those with spinal cord trauma. These results suggest a need to target health services and direct research to improved pain management, and thereby reduce the burden of neurological disease.


Assuntos
Dor Crônica/epidemiologia , Doenças do Sistema Nervoso , Autorrelato , Adulto , Idoso , Canadá/epidemiologia , Estudos Transversais , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Prevalência , Inquéritos e Questionários
6.
Neuroepidemiology ; 44(3): 130-7, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-25896718

RESUMO

BACKGROUND: Individuals with spinal cord injury (SCI) have a more than twofold increased risk of heart disease and stroke compared with able-bodied individuals. The increased risk appears to be in excess of the risk conferred by several well-established risk factors, including diabetes, hypertension, and sex. This raises the question whether other factors, secondary to SCI, are also contributing to the development of cardiovascular disease (CVD). Two potential factors associated with SCI and CVD are pain and depression. Both are frequently reported among individuals with SCI, develop in the acute stages of injury, and are commonly described as severe. Therefore, the primary aim of this study was to examine the relationship between pain (and types of pain) and depression with CVD among individuals with SCI. METHODS: A total of 1,493 individuals (referred sample) with chronic SCI participated in a self-report cross-sectional multicenter Canada-wide survey from 2011-2012 (mean age ± standard deviation: 49.6 ± 13.9 years). RESULTS: After adjustment for age, sex, and injury characteristics, neuropathic pain and depression were significantly and independently associated with CVD (adjusted odds ratio and 95% confidence interval: 2.27 (1.21, 4.60) for neuropathic pain; 4.07 (2.10, 7.87) for depression). In contrast to neuropathic pain, non-neuropathic pain was not significantly associated with CVD (p = 0.13). CONCLUSION: In conclusion, these data illustrate important interrelationships between secondary complications following SCI, as well as raise the possibility of neuropathic pain (versus nociceptive pain) as a novel and emerging risk factor for CVD.


Assuntos
Doenças Cardiovasculares/epidemiologia , Depressão/epidemiologia , Neuralgia/epidemiologia , Traumatismos da Medula Espinal/epidemiologia , Adulto , Idoso , Canadá/epidemiologia , Doenças Cardiovasculares/etiologia , Comorbidade , Estudos Transversais , Depressão/etiologia , Feminino , Inquéritos Epidemiológicos , Humanos , Incidência , Masculino , Pessoa de Meia-Idade , Modelos Teóricos , Neuralgia/etiologia , Prevalência , Risco , Traumatismos da Medula Espinal/complicações
7.
Neuroinformatics ; 20(1): 155-172, 2022 01.
Artigo em Inglês | MEDLINE | ID: mdl-34101115

RESUMO

The rise of functional magnetic resonance imaging (fMRI) has led to a deeper understanding of cortical processing of pain. Central to these advances has been the identification and analysis of "functional networks", often derived from groups of pre-selected pain regions. In this study our main objective was to identify functional brain networks related to pain perception by examining whole-brain activation, avoiding the need for a priori selection of regions. We applied a data-driven technique-Constrained Principal Component Analysis for fMRI (fMRI-CPCA)-that identifies networks without assuming their anatomical or temporal properties. Open-source fMRI data collected during a thermal pain task (33 healthy participants) were subjected to fMRI-CPCA for network extraction, and networks were associated with pain perception by modelling subjective pain ratings as a function of network activation intensities. Three functional networks emerged: a sensorimotor response network, a salience-mediated attention network, and the default-mode network. Together, these networks constituted a brain state that explained variability in pain perception, both within and between individuals, demonstrating the potential of data-driven, whole-brain functional network techniques for the analysis of pain imaging data.


Assuntos
Mapeamento Encefálico , Imageamento por Ressonância Magnética , Encéfalo/diagnóstico por imagem , Mapeamento Encefálico/métodos , Humanos , Imageamento por Ressonância Magnética/métodos , Dor/diagnóstico por imagem , Percepção da Dor
8.
J AOAC Int ; 104(2): 288-299, 2021 May 21.
Artigo em Inglês | MEDLINE | ID: mdl-33280025

RESUMO

The fatty acid composition of fats and oils is commonly determined by gas chromatography after preparing fatty acid methyl esters (FAME). Capillary columns coated with polyethylene glycol emerged as the preferred separation tool for the quantification of the polyunsaturated fatty acids contained primarily in marine oils. However, their selectivity is inadequate for measuring the trans fatty acids (TFA) contained in refined vegetable oils, dairy fats, and marine oils. Highly polar 100% poly(biscyanopropyl siloxane) capillary columns provide the necessary selectivity, but small differences in the phase polarity caused by column age, conditioning, or manufacturing variations affect the reproducibility of their separations of these complex samples. In this study, a simple procedure is described to compensate for small variations in column selectivity by adjusting the elution temperature. The balance between the dipole-induced dipole interactions and dispersive interactions was determined by measuring selectivity factors [SF(i)] corresponding to the elution of an unsaturated FAME such as 18:3n-3 relative to two saturated FAME such as 20:0 and 22:0. Knowing the SF(i) provided by the installed capillary column at a given elution temperature, and the SF(i) of the target separation, we propose a simple calculation to determine the necessary elution temperature adjustment to achieve (or restore) the desired separation. After determining the SF(i) which provides the optimal separation of TFA, the novel methodology was applied to the separation of refined vegetable oils, butter fats, and marine oils.


Assuntos
Gorduras , Ácidos Graxos , Cromatografia Gasosa , Ésteres/análise , Reprodutibilidade dos Testes
10.
J Chromatogr A ; 1619: 460955, 2020 May 24.
Artigo em Inglês | MEDLINE | ID: mdl-32081485

RESUMO

The complexity of determining the composition of animal tissue lipids is greatly increased by the presence of plasmalogens in which the alkyl chain is linked to glycerol by an enol ether bond instead of being esterified. Acidic methanolysis of animal tissue lipids provides the simultaneous scission of acyl and alkenyl ether moieties, but the complexity of the products of reaction poses a great challenge in their gas chromatographic analysis. Two-dimensional gas chromatography with online reduction (GC-OR × GC) provided the resolution of all components contained in acid methanolyzed animal lipids, taking advantage of the selective hydrogenation of alkenyl ether methanolysis products prior to the second-dimension separation (2D). In this study, we also studied the chemical transformations occurring during the acidic methanolysis of animal lipids and the subsequent gas chromatographic analysis. In particular, we observed that using methanolysis reagents contaminated with water resulted in the undesired formation of fatty aldehydes, and we made recommendations on how to avoid these side reactions using proper methanolysis conditions. Products of acidic methanolysis were studied by GC-OR × GC, GC-MS, NMR spectroscopy, and GC with flame ionization detection (GC-FID). We defined the GC-FID elution order of animal lipid acidic methanolysis products using 100 m × 0.25 mm 100% bis(cyanopropyl)siloxane columns and two different set of elution conditions: isothermal elution at 180°C, and a temperature program optimized for dairy fats. A simple procedure for isolating dimethyl acetals (DMA) prior to GC analysis is also described.


Assuntos
Técnicas de Química Analítica/métodos , Cromatografia Gasosa , Lipídeos/química , Acetais/isolamento & purificação , Tecido Adiposo/química , Animais , Hidrogenação , Metabolismo dos Lipídeos , Espectroscopia de Ressonância Magnética , Plasmalogênios/química , Plasmalogênios/metabolismo , Siloxanas/química , Temperatura
11.
J AOAC Int ; 92(5): 1284-300, 2009.
Artigo em Inglês | MEDLINE | ID: mdl-19916366

RESUMO

Trans fatty acids are found in a variety of foods like dairy and meat products, but the major dietary sources are products that contain commercially hydrogenated fats. There has been a renewed need for accurate analytical methods for the quantitation of total trans fat since mandatory requirements to declare the amount of trans fat present in food products and dietary supplements were issued in many countries. Official capillary GC and IR methodologies are the two most common validated methods used to identify and quantify trans fatty acids for regulatory compliance. The present article provides a comprehensive discussion of the GC and IR techniques, including the latest attenuated total reflection (ATR)-FTIR methodology called the negative second derivative ATR-FTIR procedure, which is currently being validated in an international collaborative study. The identification and quantitation of trans fatty acid isomers by GC is reviewed and an alternative GC method is proposed using two temperature programs and combining their results; this proposed method deals more effectively with the resolution of large numbers of geometric and positional monoene, diene, and triene fatty acid isomers present in ruminant fats. In addition, the different methylation procedures that affect quantitative conversion to fatty acid methyl esters are reviewed. There is also a lack of commercial chromatographic standards for many trans fatty acid isomers. This review points to potential sources of interferences in the FTIR determination that may lead to inaccurate results, particularly at low trans levels. The presence of high levels of saturated fats may lead to interferences in the FTIR spectra observed for trans triacylglycerols (TAGs). TAGs require no derivatization, but have to be melted prior to IR measurement. While GC is currently the method of choice, ATR-FTIR spectroscopy is a viable, rapid alternative, and a complementary method to GC for a more rapid determination of total trans fats for food labeling purposes.


Assuntos
Cromatografia Gasosa/métodos , Análise de Alimentos/métodos , Rotulagem de Alimentos/legislação & jurisprudência , Rotulagem de Alimentos/métodos , Política Nutricional , Espectrofotometria Infravermelho/métodos , Espectroscopia de Infravermelho com Transformada de Fourier/métodos , Ácidos Graxos trans/metabolismo , Dieta , Gorduras na Dieta/análise , Gorduras/química , Humanos , Metilação , Temperatura , Estados Unidos
12.
CNS Drugs ; 33(5): 503-511, 2019 05.
Artigo em Inglês | MEDLINE | ID: mdl-30949923

RESUMO

BACKGROUND: Recent observational studies have shown an association between gabapentinoid anticonvulsants and greater motor recovery after spinal cord injury. There is preclinical evidence to suggest that other anticonvulsants, such as sodium channel blockers, may also confer beneficial effects. PURPOSE: The aim of the current study was to determine if non-gabapentinoid anticonvulsants were associated with neurological recovery after acute, traumatic spinal cord injury. METHODS: This was an observational cohort study using data from the Sygen clinical trial. The primary outcome was total motor score recovery in the first year after injury. Anticonvulsant use was extracted from concomitant medication records; individuals were classified based on early administration (within 30 days of injury), or late/no administration. Motor recovery was compared using linear mixed effects regression models with a drug-by-time interaction, and adjustment for confounders. A secondary analysis incorporated a propensity score matched cohort. RESULTS: Of the cohort (n = 570), 6% received anticonvulsants (carbamazepine, phenytoin, clonazepam, phenobarbital, and valproic acid) early after injury. After adjustments for initial injury level and severity, early exposure to non-gabapentinoid anticonvulsants was not associated with motor neurological outcomes (p = 0.38 for all anticonvulsants, p = 0.83 for sodium channel blockers, p = 0.82 in propensity-matched cohort). CONCLUSION: Non-gabapentinoid anticonvulsant exposure was not associated with greater or lesser neurological recovery. This suggests that these medications, as administered for the acute management of spinal cord injury, do not impact long-term neurological outcomes.


Assuntos
Anticonvulsivantes/farmacologia , Traumatismos da Medula Espinal/tratamento farmacológico , Anticonvulsivantes/administração & dosagem , Anticonvulsivantes/uso terapêutico , Estudos de Coortes , Intervenção Médica Precoce , Humanos , Atividade Motora/efeitos dos fármacos , Recuperação de Função Fisiológica , Índices de Gravidade do Trauma , Resultado do Tratamento
13.
J Pain ; 20(5): 557-565, 2019 05.
Artigo em Inglês | MEDLINE | ID: mdl-30503860

RESUMO

Recent temporal trends in the population prevalence of chronic pain in Canada on a national and provincial level are unknown. Five cycles of the Canadian Community Health Survey (2000/2001, 2007/2008, 2009/2010, 2011/2012, and 2013/2014) were used to derive population-based estimates of the self-reported prevalence of chronic pain. Sensitivity analyses examined chronic pain prevalence among those reporting no other chronic health conditions. The prevalence of chronic pain among the general Canadian population increased by almost 4.0% (to 21.0%) in 2011/2012, after being in the range of 15.7 to 17.2% from 2000 to 2009/2010. The sudden increase in prevalence was observed 1) across all provinces in Canada, 2) in all age categories, and 3) among Canadians with no other chronic health conditions. Increasing chronic pain prevalence in Canada, most significantly occurring between 2010 and 2012, and including among healthy and young individuals, emphasizes the need for targeted research and resources to help alleviate chronic pain. PERSPECTIVE: This study uncovers a significant increase in chronic pain prevalence in Canada between 2009/2010 and 2011/2012, driven by younger Canadians that are free of the most common chronic health conditions. This discovery emphasizes the importance of further directed research and resources to help mitigate the trend of increasing chronic pain.


Assuntos
Dor Crônica/epidemiologia , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Canadá/epidemiologia , Criança , Estudos Transversais , Feminino , Inquéritos Epidemiológicos , Humanos , Masculino , Pessoa de Meia-Idade , Prevalência , Adulto Jovem
14.
Lipids ; 43(3): 259-73, 2008 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-18214567

RESUMO

Milk fat is a complex mixture of geometric and positional isomers of monounsaturated and polyunsaturated, including short-, long- and branch-chain fatty acids (FAs). There has been partial success to resolve this mixture of FAs using different GC temperature programs, or a combination of GC isothermal and temperature programs. To overcome the problem associated with overlapping isomers prior silver-ion separation was recommended. However, this procedure is time consuming and not practical for routine analysis. In addition, previous methods focused mainly on the trans and cis isomers of 18:1. The present method takes advantage of differences in the relative elution times between different types of FAs. The method involved analyzing each milk fat using the same highly polar 100-m capillary column and GC instrument, and conducting two separations using temperature programs that plateau at 175 and 150 degrees C. The relative shift among the geometric and positional isomers at these two temperature settings was enough to permit identification of most of the trans and cis 16:1, 18:1 and 20:1, the c/t-18:2 and the c/c/t-18:3 isomers found in milk fat. The identity of these FAs was confirmed by prior separation of the total fatty acid methyl esters (FAMEs) of milk fat using Ag(+)-SPE columns, and comparing the fractions to the total milk fat. The Ag(+)-SPE technique was modified to obtain pure saturated, trans- and cis-monounsaturated and diunsaturated FAMEs. By combining the results from these two separate GC analyses, knowing the elution order, it was possible to determine most of the geometric and positional isomers of 16:1, 18:1, 20:1, 18:2 and 18:3 without a prior silver-ion separation. Only few minor FAs could not be resolved, notable the conjugated linoleic acid isomers that still required the complimentary Ag(+)-HPLC separation. The two GC temperature programs have been successfully used to routinely analyze most FA isomers in total milk and beef fats in about 200 min without the use of prior silver-ion separations.


Assuntos
Cromatografia Gasosa/métodos , Gorduras/análise , Ácidos Linoleicos Conjugados/análise , Ácidos Linoleicos/análise , Leite/química , Extração em Fase Sólida/métodos , Animais , Bovinos , Gorduras/isolamento & purificação , Isomerismo , Ácidos Linoleicos/isolamento & purificação
15.
Lipids ; 53(11-12): 1097-1112, 2018 11.
Artigo em Inglês | MEDLINE | ID: mdl-30652315

RESUMO

Extra virgin olive oils (EVOO) command higher prices because they contain health-promoting nutrients and desirable sensory characteristics. Many targeted methods have limited success in determining olive oil authenticity. Therefore, attention has been paid to rapid spectroscopic methods that provide the composition of multiple components. A Fourier transform near infrared (FT-NIR) method was reported that identified five major fatty acids and volatiles in EVOO, plus four models that identify common adulterants and their content. However, it did not include diacylglycerol (DAG) and unesterified fatty acids (FFA) known to be associated with freshness of the oil. The newly improved FT-NIR method now includes 1,2-DAG and 1,3-DAG models based on the DAG isomer content in freshly prepared EVOO, and a FFA model based on quantitative addition of oleic acid. The new FT-NIR method was used to reassess previously used EVOO products to evaluate their freshness. Based on these results and review of the published data, we propose several revisions to the EVOO regulation: limit FFA to ≤0.5%, include 1,2-DAG and 1,3-DAG in standard, place no limit on 1,2-DAG because it characterizes the oils, set the 1,3-DAG content to ≤1.0%, and lower the content of 18:2n-6 to 1.5%.


Assuntos
Diglicerídeos/análise , Ácidos Graxos não Esterificados/química , Azeite de Oliva/química , Espectroscopia de Infravermelho com Transformada de Fourier/métodos
16.
J Agric Food Chem ; 66(4): 842-855, 2018 Jan 31.
Artigo em Inglês | MEDLINE | ID: mdl-29291262

RESUMO

Incubation of DHA with sheep rumen fluid resulted in 80% disappearance in 6 h. The products were analyzed as their fatty acid (FA) methyl esters by GC-FID on SP-2560 and SLB-IL111 columns. The GC-online reduction × GC and GC-MS techniques demonstrated that all DHA metabolites retained the C22 structure (no evidence of chain-shortening). Two new transient DHA products were identified: mono-trans methylene interrupted-DHA and monoconjugated DHA (MC-DHA) isomers. Identification of MC-DHA was confirmed by their predicted elution using equivalent chain length differences from C18 FA, their molecular ions, and the 22:5 products formed which were the most abundant at 6 h. The 22:5 structures were established by fragmentation of their 4,4-dimethyloxazoline derivatives, and all 22:5 products contained an isolated double bond, suggesting formation via MC-DHA. The most abundant c4,c7,c10,t14,c19-22:5 appeared to be formed by unknown isomerases. Results suggest that the initial biohydrogenation of DHA was analogous to that of C18 FA.


Assuntos
Ácidos Docosa-Hexaenoicos/metabolismo , Rúmen/microbiologia , Ovinos , Animais , Cromatografia Gasosa/métodos , Ácidos Docosa-Hexaenoicos/química , Esterificação , Ácidos Graxos/metabolismo , Hidrogenação
17.
J Agric Food Chem ; 55(4): 1164-9, 2007 Feb 21.
Artigo em Inglês | MEDLINE | ID: mdl-17253708

RESUMO

The fatty acid and tocopherol compositions of three heartnut (Juglans ailanthifolia var. cordiformis) varieties (Imshu, Campbell CW1, and Campbell CW3) were examined and compared with those of two Persian walnut (Juglans regia L.) varieties (Combe and Lake). The major fatty acids found in heartnuts and walnuts were identified by gas chromatography as linoleic (18:2n-6), alpha-linolenic (18:3n-3), oleic (18:1n-9), palmitic (16:0), and stearic acid (18:0). Polyunsaturated fatty acids were the main group of fatty acids found in both heartnut and walnut, ranging from 73.07 to 80.98%, and were significantly higher in heartnut than in Persian walnuts (P < 0.001). In addition, heartnuts had significantly higher levels of 18:2n-6 and lower levels of 18:3n-3 compared to the Persian walnuts. gamma-Tocopherol was the main tocopherol homologue present in both types of nuts, followed by delta- and alpha-tocopherol. The highest concentration of gamma-tocopherol was found in Combe Persian walnut at 267.87 mug/g, followed by Lake Persian walnut and Imshu, Campbell CW1, and CW3 heartnut at 205.45, 187.33, 161.84, and 126.46 mug/g, respectively. Tocopherols, particularly the gamma-tocopherol, were found to contribute the most to the strong total antioxidant activities of both walnut and heartnut oils using either the free radical 2,2-diphenyl-1-picrylhydrazyl assay or the photochemiluminescence method.


Assuntos
Antioxidantes/análise , Ácidos Graxos/análise , Juglans/química , Nozes/química , Tocoferóis/análise , Cromatografia Gasosa , gama-Tocoferol/análise
18.
Lipids ; 42(4): 361-82, 2007 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-17406931

RESUMO

The total lipids of the longissimus dorsi muscle were analyzed from commercial adult Sarda sheep in Sardina taken from local abattoirs, and in the subsequent year from three local farms in the Sassari region that provided some information on the amount and type of supplements fed to the pasture-fed sheep. The complete lipid analysis of sheep meat included the fatty acids from O-acyl and N-acyl lipids, including the trans- and conjugated linoleic acid (CLA) isomers and the alk-1-enyl ethers from the plasmalogenic lipids. This analysis required the use of a combination of acid- and base-catalyzed methylation procedures, the former to quantitate the O-acyl, N-acyl and alkenyl ethers, and the latter to determine the content of CLA isomers and their metabolites. A combination of gas chromatographic and silver-ion separation techniques was necessary to quantitate all of the meat lipid constituents, which included a prior separation of the trans-octadecenoic acids (18:1) and a separation of fatty acid methyl esters and the dimethylacetals (DMAs) from the acyl and alk-1-enyl ethers, respectively. The alk-1-enyl moieties of the DMAs were analyzed as their stable cyclic acetals. In general, about half of the meat lipids were triacylglycerols, even though excess fat was trimmed from the meat. The higher fat content in the meat appears to be related to the older age of these animals. The variation in the trans-18:1 and CLA isomer profiles of the Sarda sheep obtained from the abattoirs was much greater than in the profiles from the sheep from the three selected farms. Higher levels of 10t-18:1, 7t9c-18:2, 9t11c-18:2 and 10t12c-18:2 were observed in the commercial sheep meat, which reflected the poorer quality diets of these sheep compared to those from the three farms, which consistently showed higher levels of 11t-18:1, 9c11t-18:2 and 11t13c-18:2. In the second study, sheep were provided with supplements during the spring and summer grazing season, which contributed to higher levels of 11t-18:1 and 9c11t-18:2. The farm that provided a small amount of supplements during the spring had the better lipid profile at both time periods. The polyunsaturated fatty acid (PUFA) content was higher in the meat from Sarda sheep from the three farms than in the meat from those sheep obtained from commercial slaughter operations. The plasmalogenic lipid content ranged from 2 to 3% of total lipids, the alk-1-enyl ethers consisted mainly of saturated and monounsaturated moieties, and the trans-18:1 profile was similar to that of the FA. The n-6 (6-8%) and n-3 PUFA (2-3%) contents, the n-6/n-3 ratio (3:1), as well as the saturated fatty acid (SFA) content (42-45%) and the SFA to PUFA ratio (4:1 to 5:1) of the Sarda sheep from the three farms were comparable to sheep meat lipids found in similar commercial operations in Europe. Inclusion of small amounts of supplements for the grazing Sarda sheep resulted in improved quality of sheep meat lipids.


Assuntos
Ácidos Graxos/análise , Ácidos Linoleicos Conjugados/análise , Carne/análise , Ácidos Graxos trans/análise , Animais , Cromatografia Gasosa , Cromatografia Líquida de Alta Pressão , Cromatografia em Camada Fina , Ácidos Graxos/química , Ácidos Graxos Insaturados/análise , Ácidos Graxos Insaturados/química , Isomerismo , Ácidos Linoleicos Conjugados/química , Ovinos , Ácidos Graxos trans/química , Triglicerídeos/análise , Triglicerídeos/química
19.
Lipids ; 42(6): 509-18, 2007 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-17492324

RESUMO

Muskox (Ovibos moschatus) are ruminant animals native to the far north and little is known about their fatty acid composition. Subcutaneous adipose tissue (backfat) from 16 wild muskox was analyzed and compared to backfat from 16 barley fed beef cattle. Muskox backfat composition differed substantially from beef and the most striking difference was a high content of 18:0 (26.8 vs. 9.77%). This was accompanied by higher levels of most other saturated fatty acids except beef had more 16:0. Muskox backfat also had a lower level of cis-18:1 and this was related to a lower expression of steroyl-CoA desaturase mRNA. Beef backfat had a higher level of total trans-18:1 (4.25 vs. 2.67%). The most prominent trans-18:1 isomers in beef backfat were 10t-18:1 (2.13%) and 11t-18:1 (0.77%) whereas the most prominent isomers in muskox backfat were 11t-18:1 (1.41%), 13t/14t- (0.27%) and 16t-18:1 (0.23%). The total conjugated linoleic acid (CLA) content was higher in beef backfat than muskox (0.67 vs. 0.50%) with 9c,11t-18:2 as the most abundant CLA isomer. The second most abundant CLA isomer in beef backfat was 7t,9c-18:2 (0.10%) whereas in muskox it was 11t13c-18:2 (0.04%). Muskox backfat had a higher content of 18:3n-3 and its elongation and desaturation products 20:5n-3, 22:5n-3 and 22:6n-3 and a lower n-6/n-3 ratio. Overall, the high forage diet of muskox seemed to produce a healthier fatty acid profile and highlighted the need to develop feeding strategies for intensively raising beef that will not negatively impacting fatty acid composition.


Assuntos
Gorduras na Dieta/análise , Ácidos Linoleicos Conjugados/análise , Carne/análise , Ruminantes/fisiologia , Gordura Subcutânea/química , Ácidos Graxos trans/análise , Ração Animal , Animais , Composição Corporal , Bovinos , Ácidos Graxos Dessaturases/metabolismo , Ácidos Graxos/análise , Ácidos Graxos Insaturados/análise , Hordeum , Metabolismo dos Lipídeos/fisiologia , Músculo Esquelético/química , Músculo Esquelético/metabolismo , Especificidade da Espécie , Gordura Subcutânea/metabolismo
20.
Meat Sci ; 124: 39-47, 2017 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-27835833

RESUMO

The objective of the present study was to assess the fatty acid composition of horse-meat available at the retail market in northern Spain. Horse steaks (Longissimus thoracis et lumborum muscle; n=82) were purchased from butcher-shops and large grocery stores throughout six northern regions of Spain in two different seasons. Fat content differed significantly among regions (1.12 to 2.77%). Samples with higher intramuscular fat content presented the highest percentages of total monounsaturated fatty acids and the lowest contents of dimethylacetal and polyunsaturated fatty acids (PUFA), while the opposite was found in the leanest samples. A high variability was observed in the muscle and subcutaneous n-3 PUFA content. Overall, total n-3 PUFA content ranged between 1.17% and 18.9% in muscle fat and between 1.52% and 27.9% in backfat. Interestingly, almost 5% of surveyed loins from horse carcasses (4 out of 82) contained over 300mg of linolenic acid per 100g of meat which could have been marketed as a "source" of n-3 FAs according to Commission Regulation (EU) No 116/2010.


Assuntos
Ácidos Graxos/análise , Cavalos , Carne/análise , Animais , Gorduras na Dieta/análise , Ácidos Graxos Monoinsaturados/análise , Ácidos Graxos Ômega-3/análise , Ácidos Graxos Insaturados/análise , Análise de Alimentos , Músculo Esquelético/química , Valor Nutritivo , Espanha
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