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1.
HNO ; 56(3): 325-7, 2008 Mar.
Artículo en Alemán | MEDLINE | ID: mdl-17333042

RESUMEN

Thrombosis of the internal jugular vein is a rare form of deep vein thrombosis with potentially life threatening complications. We report on a 46-year-old male presenting with dysphagia and neck swelling. An extensive thrombosis of the internal jugular vein was found on ultrasound of the neck. An interdisciplinary workup revealed an occult gastric carcinoma. This case demonstrates that concomitant malignancies may contribute to a thrombosis of the internal jugular vein, which is then the primary symptom presented by the patient.


Asunto(s)
Venas Yugulares/diagnóstico por imagen , Síndromes Paraneoplásicos/diagnóstico , Síndromes Paraneoplásicos/terapia , Neoplasias Gástricas/diagnóstico , Neoplasias Gástricas/cirugía , Trombosis de la Vena/diagnóstico , Trombosis de la Vena/terapia , Diagnóstico Diferencial , Humanos , Masculino , Persona de Mediana Edad , Resultado del Tratamiento , Ultrasonografía
2.
Biochim Biophys Acta ; 795(1): 100-7, 1984 Aug 15.
Artículo en Inglés | MEDLINE | ID: mdl-6466690

RESUMEN

The interaction of lipid hydroperoxides and secondary oxidation products with DNA was investigated by evaluating the fluorescence formed in the presence of metals and reducing agents. We also investigated the effect of malonaldehyde, because it has been generally considered responsible for the formation of fluorescence with DNA. However, malonaldehyde usually has been estimated by the notoriously unspecific thiobarbituric acid test. At low concentration of oxidation products (1 mM), fluorescence formation required the presence of metals and ascorbic acid. In contrast, a positive thiobarbituric acid reaction was obtained with many lipid oxidation products without metals or ascorbic acid. Monohydroperoxides from autoxidized methyl linoleate and linolenate produced the highest level of fluorescence. Hydroperoxy epidioxides of linolenate and dihydroperoxides of linoleate and linolenate were among the most active secondary products in forming fluorescence with DNA. In contrast, malonaldehyde produced very little fluorescence under our conditions. The thiobarbituric acid values did not correlate with fluorescence formation. This study showed that, in our model reaction system, DNA forms fluorescent products by the breakdown of lipid oxidation products in the presence of metals and ascorbic acid into reactive materials other than malonaldehyde. Therefore, the importance of malonaldehyde in its crosslinking properties with DNA may have been exaggerated in the literature.


Asunto(s)
ADN , Peróxidos Lipídicos , Metales , Ácido Ascórbico , Fenómenos Químicos , Química , Cisteína , Espectrometría de Fluorescencia , Tiobarbitúricos
3.
Biochim Biophys Acta ; 919(3): 239-44, 1987 Jun 23.
Artículo en Inglés | MEDLINE | ID: mdl-3593747

RESUMEN

To clarify the mechanism of fluorescence formation between DNA and lipid degradation products in the presence of ferric chloride and ascorbic acid, a number of carbonyl compounds and decomposition products of pure methyl linolenate hydroperoxides were examined. Keto derivatives of methyl ricinoleate, linoleate, and oleate, alkanals and 2-alkenals produced little or no fluorescence with DNA in the presence of ferric chloride-ascorbic acid. 2,4-Alkadienals were more active and 2,4,7-decatrienal was the most active. Mixtures of volatile aldehydes prepared from linolenate hydroperoxide decomposed either thermally or with iron and ascorbate had the same activity as 2,4,7-decatrienal. Higher molecular-weight products from the decomposition of methyl linolenate hydroperoxides showed relatively low activity. beta-Carotene, alpha-tocopherol and other antioxidants effectively reduced the amount of fluorescence formed by linolenate hydroperoxides. The results suggest that, in addition to hydroperoxide decomposition products, singlet oxygen and/or free radical species contribute significantly to the fluorescence formed from the interaction of methyl linolenate hydroperoxides with DNA in the presence of ferric chloride and ascorbic acid.


Asunto(s)
ADN , Peróxidos Lipídicos , Aldehídos , Antioxidantes , Ácido Ascórbico , Carotenoides , Fenómenos Químicos , Química , Cloruros , Compuestos Férricos , Radicales Libres , Gases , Oxígeno , Espectrometría de Fluorescencia , Vitamina E , beta Caroteno
4.
Chirurg ; 76(8): 757-64, 2005 Aug.
Artículo en Alemán | MEDLINE | ID: mdl-16028048

RESUMEN

Fetal surgery is a newly evolving multidisciplinary medical field, being performed in specialized centers. It deals with the treatment of selected fetuses with congenital anomalies that cause high morbidity and mortality. The aim of the surgical treatment is to avoid the development of progressive and eventually irreversible damage at birth. Examples of entities treated are obstructive uropathy leading to renal insufficiency, lung hypoplasia in severe congenital diaphragmatic hernia, severe congenital cystic adenomatoid malformation of the lung, and sacrococcygeal teratoma. This review describes principles of fetal surgery, physiopathologic processes of some of the anomalies treated in this way, and diagnostic and therapeutic approaches. Recently published results are presented and discussed.


Asunto(s)
Anomalías Congénitas/cirugía , Enfermedades Fetales/cirugía , Cóccix/cirugía , Anomalías Congénitas/diagnóstico , Anomalías Congénitas/etiología , Malformación Adenomatoide Quística Congénita del Pulmón/cirugía , Femenino , Muerte Fetal/etiología , Enfermedades Fetales/diagnóstico , Enfermedades Fetales/etiología , Hernia Diafragmática/cirugía , Hernias Diafragmáticas Congénitas , Humanos , Hidronefrosis/congénito , Hidronefrosis/cirugía , Recién Nacido , Trabajo de Parto Prematuro/etiología , Embarazo , Diagnóstico Prenatal , Pronóstico , Sacro/cirugía , Neoplasias de la Columna Vertebral/congénito , Neoplasias de la Columna Vertebral/cirugía , Teratoma/congénito , Teratoma/cirugía , Sistema Urinario/anomalías , Sistema Urinario/cirugía
5.
Chest ; 92(5): 836-8, 1987 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-3665597

RESUMEN

The possibility that venous blood could be withdrawn through a radial artery cannula when venous pressure is high was examined in 30 patients during cardiopulmonary bypass for coronary artery bypass operation. Progressive desaturation of radial artery blood occurred when venous pressure was equal to arterial pressure. Desaturation not only increased with duration of venous obstruction but also occurred immediately if the arterial tree was emptied after occlusion. We believe that these observations result from the transcapillary aspiration of deep venous blood and may produce a potential source of error in measuring arterial oxygen tension during cardiopulmonary resuscitation, cardiac tamponade, and profound right heart failure, as well as cardiopulmonary bypass.


Asunto(s)
Puente Cardiopulmonar , Oxígeno/sangre , Brazo/irrigación sanguínea , Arterias , Presión Sanguínea , Recolección de Muestras de Sangre , Humanos , Venas , Presión Venosa
6.
Metabolism ; 38(10): 983-9, 1989 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-2677612

RESUMEN

Sepsis and extensive burn injury produce clinical syndromes characterized in part by "insulin resistance," but it is unclear if these insulin resistant states are identical. To test if the maximal biological effectiveness of insulin is altered in septic or burned patients, eight septic patients and eight nonseptic patients recovering from severe burn injury were studied using the hyperinsulinemic eukalemic euglycemic clamp technique. Compared with bed-rested controls, the septic patients showed an insulin-induced plasma clearance of potassium, which was 183% higher (P less than .001), and a concomitant glucose clearance, which was 52% lower (P less than .001). Nonseptic burn patients also had a 91% increase in potassium clearance (P less than .05), but their maximal insulin-stimulated glucose uptake was not different from that of bedrested controls. When septic patients were compared with their nonseptic burned counterparts, there was no difference in potassium clearance in response to insulin, but glucose uptake by the septic patients was 47% lower (P less than .001). Insulin infusion completely suppressed hepatic glucose production in both septic patients and in nonseptic burn patients. The percent of whole body glucose uptake that was oxidized was not different between the septic patients and the nonseptic postburn patients in both the basal and insulin-stimulated states (38% and 51% v 38% and 42%, respectively). It is concluded that septic and postburn insulin resistance differ in that peripheral glucose uptake in sepsis, but not nonseptic burn injury, is refractory to pharmacologic insulin stimulation, whereas in both states insulin effectively stimulates potassium uptake.


Asunto(s)
Quemaduras/metabolismo , Resistencia a la Insulina , Sepsis/metabolismo , Adulto , Reposo en Cama , Glucemia/análisis , Técnica de Clampeo de la Glucosa , Humanos , Insulina/administración & dosificación , Insulina/sangre , Sistemas de Infusión de Insulina , Tasa de Depuración Metabólica , Potasio/sangre
7.
Science ; 152(3726): 1283, 1966 May 27.
Artículo en Inglés | MEDLINE | ID: mdl-5937125

Asunto(s)
Conducta , Cultura , Inuk , Alaska , Humanos
8.
Brain Res ; 117(2): 195-210, 1976 Nov 26.
Artículo en Inglés | MEDLINE | ID: mdl-990914

RESUMEN

Anterograde degeneration resulting from small lesions placed in either the insular or temporal cortex were traced with the Fink-Heimer reduced silver procedure. In neocortical regions ipsilateral to the lesion axonal degeneration was present in auditory subdivisions AI, AII, Ep, I, T, in the second somatosensory area (SII), in the anterior and middle suprasylvian gyrus, in the posteromedial suprasylvian and posterior lateral gyri, in the posterior splenial gyrus, in the anterior two-thirds of the cingulate gyrus and in the orbitofrontal regions. With respect to interhemispheric connections, evidence was obtained for a dual pattern of projection. In addition to significant amounts of axonal and terminal degeneration in the corresponding insular or temporal fields, axonal degeneration was also present in posterior AII. In the thalamus degeneration was found in the medial dorsal, suprageniculate, and lateral posterior-pulvinar nuclei. In the posterior nuclear group (Po) and the principal division of the medial geniculate (GMp) evidence was obtained for a topographic pattern of projection; significantly more degeneration occurred in caudal Po following insular lesions whereas with temporal lesions more degeneration occurred in caudal GMp. Degeneration was also found in the dorsal cortex of the ipsilateral inferior colliculus, bilaterally in the deep layers of the superior colliculus and the periventricular central gray region, ipsilaterally in the ventromedial aspects of the head and body of the caudate nucleus, and in the lateral and central nuclei of the amygdala. These findings are discussed in terms of their significance for a possible role for the insular and temporal neocortex (I-T) in both multimodal sensory discrimination and sensory-visceral integrative functions.


Asunto(s)
Corteza Cerebral/fisiología , Animales , Vías Auditivas , Ganglios Basales/fisiología , Gatos , Vías Eferentes , Sistema Límbico/fisiología , Mesencéfalo/fisiología , Degeneración Nerviosa , Lóbulo Temporal/fisiología , Tálamo/fisiología , Corteza Visual/fisiología
9.
J Exp Psychol Hum Percept Perform ; 6(4): 745-50, 1980 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-6449541

RESUMEN

With miniature microphones inserted into the external ear canals of a model and the sound source 90 degrees to left of midline, low-pass, and broadband noise bursts were picked up and recorded on magnetic tape. The bursts were generated in two highly contrasting acoustic environments: an anechoic and an echoic chamber. The taped sounds were played back monaurally and binaurally via headphones to 16 listeners seated in an acoustically neutral setting. They were instructed to estimate the distance of the stimuli. Apparent distances of bursts recorded in the echoic or reverberant chamber far exceeded those recorded in the anechoic chamber. It mattered not whether the sounds were presented monaurally or binaurally. What did influence distance estimates dramatically was the frequency composition of the stimuli. Low-pass sounds recorded in either acoustic environment were consistently judged to be further removed than high-pass sounds recorded in the same setting. They were also more likely to appear from behind the listener. In our moment-to-moment transaction with the acoustic environment, distant sounds generally have less acoustic energy in the higher audio frequency. We suggest that this lifetime of auditory experience influenced our listeners' scale of relative distance.


Asunto(s)
Percepción Auditiva , Percepción de Distancia , Localización de Sonidos , Aprendizaje Discriminativo , Dominancia Cerebral , Humanos , Enmascaramiento Perceptual
10.
J Chromatogr A ; 905(1-2): 85-102, 2001 Jan 05.
Artículo en Inglés | MEDLINE | ID: mdl-11206810

RESUMEN

Normal, high stearic acid and high lauric acid canola oil varieties were heated in the presence of air to allow autoxidation to occur. After the reaction, the oils were analyzed using a non-aqueous reversed-phase high-performance liquid chromatographic separation followed by detection using atmospheric pressure chemical ionization mass spectrometry. Oxidized products were separated and identified. The major autoxidation products which remained intact were epoxides and hydroperoxides. Two classes of epoxy triacylglycerols (TAGs) were formed. One class with the epoxy group replacing a site of unsaturation and one class adjacent to a site of unsaturation, as was previously reported for model TAGs. Intact oxidation products resulted mostly from oxidation of oleic acid, while oxidation products of linoleic and linolenic acid chains decomposed to yield chain-shortened species. Both neutral and polar chain-shortened products were observed. Polar chain-shortened decomposition products eluted at very short retention times and required a different chromatographic gradient to separate the molecules. This class of molecules was tentatively identified as core aldehydes. The high stearic acid canola oil yielded more intact oxidation products containing stearic acid, as expected. The high lauric acid oil produced intact oxidation products which contained lauric acid.


Asunto(s)
Cromatografía Liquida/métodos , Ácidos Grasos Monoinsaturados/química , Ingeniería Genética , Espectrometría de Masas/métodos , Oxidación-Reducción , Aceite de Brassica napus
11.
J Chromatogr A ; 852(2): 417-32, 1999 Aug 13.
Artículo en Inglés | MEDLINE | ID: mdl-10481980

RESUMEN

Oxidation products from triolein under model heated frying conditions have been analyzed using liquid chromatography with an evaporative light scattering detector and atmospheric pressure chemical ionization (APCI) mass spectrometric detection. Triolein was heated at 190 degrees C with 2% water added each hour, to simulate the moisture of a frozen product, until polar components reached approximately 30%. The samples were separated using reversed-phase high-performance liquid chromatography with APCI-MS detection. Triolein oxidation products included hydroperoxides, epoxides and a ketone. Other products were formed by shortening of an acyl chain on the intact triolein. Normal and oxygen-containing products formed by the dimerization of triolein were also observed. Other products included chain addition products formed by addition of acyl chain subunits to intact triolein to form higher molecular weight products.


Asunto(s)
Cromatografía Líquida de Alta Presión/métodos , Culinaria , Aceites de Plantas , Trioleína/química , Espectrometría de Masas , Volatilización
12.
J Chromatogr A ; 912(1): 187-90, 2001 Mar 30.
Artículo en Inglés | MEDLINE | ID: mdl-11307983

RESUMEN

Reversed-phase HPLC resolution and HPLC-flame ionization detection quantitation of model triacylglycerol positional isomer pairs (important in the study of food formulation lipids) after facile conversion to brominated derivatives is reported. The positional isomers in the triacylglycerol pairs were at least 98% resolved from each other during reversed-phase HPLC. Triacylglycerol quantitation obtained by HPLC-flame ionization detector was checked against standard positional isomer pairs known by mass. The flame ionization detection area percent gave absolute error range of 0.3-1.6% per triacylglycerol.


Asunto(s)
Bromo/química , Cromatografía Líquida de Alta Presión/métodos , Análisis de los Alimentos , Triglicéridos/análisis , Ionización de Llama , Isomerismo
13.
Physiol Behav ; 24(6): 1149-56, 1980 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-6774349

RESUMEN

Studies in the monkey have shown that cortex outside of the primary projection areas in the superior temporal gyrus and in the inferotemporal region in important for the execution of some auditory and visual descriminations. In this study, six monkeys were trained to perform four auditory and two visual discriminations. Retention tests were given prior to bilateral removal of the anterior part of the lateral surface of the superior temporal gyrus, the inferotemporal region, or both areas together. Superior temporal ablations elicited severe deficits on some auditory discriminations. Inferotemporal ablations caused little or no impairment on visual discriminations. This negative finding is attributed to the sequential rather than spatial mode of presentation of visual stimuli, and to overtraining. A single monkey trained on a spatial visual pattern problem without overtraining was impaired. Another monkey tranied to perform an auditory reverse intensity discrimination exhibited a deficit in ability to perform the problem after removal of auditory cortex within the lateral fissure.


Asunto(s)
Percepción Auditiva/fisiología , Corteza Cerebral/fisiología , Aprendizaje/fisiología , Percepción Visual/fisiología , Animales , Reacción de Prevención/fisiología , Haplorrinos , Macaca mulatta , Sobreaprendizaje/fisiología , Factores de Tiempo
14.
Am J Surg ; 131(3): 380-1, 1976 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-1259105

RESUMEN

A patient with a parathyroid adenoma located beneath the throid capsule and within a benign thyroid adenoma is reported on. To the best of our knowledge, this lesion has not previously been reported. This case points out the difficulties that may be encountered when it is necessary to locate a missing parathyroid gland in a patient with multinocular goiter. In this clinical setting there may be a role for use of the various technics recommended for preoperative localization of a parathyroid adenoma.


Asunto(s)
Coristoma/cirugía , Glándulas Paratiroides , Neoplasias de la Tiroides/cirugía , Adenoma/patología , Adenoma/cirugía , Humanos , Hiperparatiroidismo/patología , Hiperparatiroidismo/cirugía , Persona de Mediana Edad , Glándulas Paratiroides/patología , Glándulas Paratiroides/cirugía , Neoplasias de las Paratiroides/patología , Neoplasias de la Tiroides/patología
15.
J Agric Food Chem ; 49(1): 446-57, 2001 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-11170612

RESUMEN

Several margarine base stock candidates have previously been prepared for the purpose of finding better, more oxidatively stable food components: high-saturate vegetable oils, randomized vegetable oils, vegetable oil-hard stock blends, and interesterified vegetable oil-hard stock blends. Here are reported the triacylglycerol compositions of these products, determined using reverse-phase high-performance liquid chromatography (HPLC) coupled with a flame ionization detector or a quadrupole mass spectrometer with an atmospheric pressure chemical ionization source. Triacylglycerol percent composition results for samples of known composition (randomized and interesterified samples) exhibited less average error by HPLC coupled with a quadrupole mass spectrometer with an atmospheric pressure chemical ionization source, after application of response factors, than the results by HPLC coupled with a flame ionization detector. The fatty acid compositions calculated from the mass spectrometric data exhibited less average error than the fatty acid compositions resulting from the flame ionization detector data. The average error of the fatty acid compositions by the mass spectrometer was lowest for interesterified blend samples, next lowest for randomized samples, then followed by high-saturated fatty acid oils, normal oils, and blends. Analysis of the vegetable oil-hard stock blends by mass spectrometer required special treatment for calculation of response factors.


Asunto(s)
Cromatografía Líquida de Alta Presión/métodos , Margarina/análisis , Espectrometría de Masas/métodos , Triglicéridos/análisis , Aceite de Maíz/análisis , Ácidos Grasos/análisis , Ácidos Grasos Monoinsaturados/análisis , Aceites de Plantas/química , Aceite de Brassica napus , Aceite de Soja/análisis , Ácidos Esteáricos/análisis
16.
J Agric Food Chem ; 49(2): 899-905, 2001 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-11262047

RESUMEN

To determine sources of desirable deep-fried flavor in frying oils, degradation products from heated triolein and trilinolein with 5-31% polar compounds representing low to high deterioration were evaluated by purge-trap gas chromatography-mass spectrometry-olfactometry. (E,E)-2,4-Decadienal, 2-heptenal, 2-octenal, 2,4-nonadienal, and 2,4-octadienal produced deep-fried odor at moderate-strong intensities in heated trilinolein. However, unexpected aldehydes-2,4-decadienal, 2,4-undecadienal, 2,4-nonadienal, and 2-octenal (all <15 ppm)-were produced in triolein heated for 6 h. These dienals possibly were produced by hydroperoxidation and/or hydroxylation followed by dehydration of 2-alkenals. The 2-alkenals were produced from thermal decomposition of hydroperoxides, epoxides, and keto and dimeric compounds produced during the heating of triolein. These aldehydes produced low intensities of deep-fried odor in triolein. This information helps to explain sources of the deep-fried flavor that is characteristic of high linoleic frying oils but which is only at low intensity levels in high oleic frying oils.


Asunto(s)
Ácido Linoleico/química , Odorantes , Ácido Oléico/química , Gusto , Triglicéridos/química , Trioleína/química , Cromatografía Líquida de Alta Presión/métodos , Culinaria , Cromatografía de Gases y Espectrometría de Masas/métodos , Calor , Humanos , Volatilización
17.
Food Chem Toxicol ; 23(12): 1041-7, 1985 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-3908249

RESUMEN

Nine hydroperoxy and hydroperoxy-epidioxy oxidation products derived from either autoxidation (AO) or photosensitized oxidation (PO) of methyl linoleate (MLo) or methyl linolenate (MLn) were tested for mutagenic activity by the Salmonella typhimurium his+ reversion assay using strains TA100, TA98, TA102, TA97 and TA1537. All nine oxidation products, monohydroperoxides from AO-MLn (I) or from PO-MLn (II), dihydroperoxides from PO-MLo (III), AO-MLn (IV) or PO-MLn (V), hydroperoxy epidioxides from PO-MLo (VI), AO-MLn (VII) or PO-MLn (VIII) and hydroperoxy bis-epidioxides from PO-MLn (IX), were weakly mutagenic in strains TA97 and/or TA100. The hydroperoxy epidioxides (VI-IX) exhibited significantly greater activity in strain TA97 than did the monohydroperoxides (I, II) or the dihydroperoxides (III-V). In strain TA100, all of the oxidation products tested exhibited similar activity. No major differences between products derived from autoxidized and photooxidized MLn (I v. II, IV v. V, VII v. VIII) were obtained. Rat-liver S-9 reduced the toxicity of all oxidation products to the tester strains. The greatest mutant yields were usually obtained in the presence of S-9, but mutagenic potency was sometimes greater without S-9. The structural feature common to all of the mutagenic oxidation products was the presence of a hydroperoxy group, suggesting that this characteristic is responsible for the observed mutagenicity, either directly or through a common degradative pathway to reactive products of lower molecular weight.


Asunto(s)
Ácidos Linoleicos/toxicidad , Ácidos Linolénicos/toxicidad , Peróxidos Lipídicos/toxicidad , Mutágenos , Animales , Biotransformación , Técnicas In Vitro , Hígado/metabolismo , Masculino , Pruebas de Mutagenicidad , Oxidación-Reducción , Ratas , Ratas Endogámicas , Salmonella typhimurium/genética , Relación Estructura-Actividad
18.
Rofo ; 133(3): 258-61, 1980 Sep.
Artículo en Alemán | MEDLINE | ID: mdl-6451547

RESUMEN

Thirty-one carotid artery stenoses were produced in thirty dogs by three different techniques. Twenty-three of these could be cured by transfemoral percutaneous catheter dilatation. High grade tight stenoses may present resistance which cannot be overcome by the catheter. Histological examination of the dilated vessels showed circumscribed changes in the vessel wall, with destruction of elastic membranes. From our experience of catheter dilatation of pelvic and lower limb arteries and of renal arteries, we consider it feasible to use this technique in selected patients with carotid stenosis.


Asunto(s)
Arterias Carótidas/diagnóstico por imagen , Trombosis de las Arterias Carótidas/terapia , Cateterismo/métodos , Angiografía , Animales , Arterias Carótidas/patología , Trombosis de las Arterias Carótidas/patología , Dilatación/métodos , Perros
19.
Lipids ; 27(6): 442-6, 1992 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-27519670

RESUMEN

Trilinoleoylglycerol (LLL), trilinolenoylglycerol (LnLnLn) and four synthetic triacylglycerols were autoxidized and the volatile products were investigated to determine the effect of fatty acid glyceride position on the mechanism of hydroperoxide decomposition. Capillary gas chromatography provided a sensitive method to follow the volatile oxidation products of mixtures of LLL and LnLnLn and of synthetic triacylglycerols containing linoleate and linolenate in different known positions. The relative amount of linoleate oxidation was determined by analyzing for hexanal, 2-heptenal and 2,4-decadienal, and the relative amount of linolenate oxidation by analyzing for 2,4-heptadienal and 2,4,7-decatrienal. The volatiles from pure monohydroperoxides of LLL and LnLnLn were compared with those of the corresponding triacylglycerols by capillary gas chromatography. Significant differences in the distribution of volatile products were observed depending on the triacylglycerols precursor. A 1∶1 mixture of LLL and LnLnLn autoxidized at 40°C showed an equal contribution of linolenate and linoleate volatiles at a peroxide value of 34. The synthetic triacylglycerols LLnL and LLLn (L, linoleic; Ln, linolenic acid) formed initially about the same total volatiles, whereas LnLnL formed more volatiles than LnLLn. The ratio Ln to L volatile products was the same for the diL triacylglycerols, and higher for LnLnL than for LnLLn. This new information should permit us to better understand the influence of triacylglycerol structure on the relative oxidative stability of unsaturated triacylglycerols.

20.
Lipids ; 23(4): 295-8, 1988 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-27520006

RESUMEN

High-molecular weight compounds previously were found to be important secondary products from autoxidation of polyunsaturated fatty esters. The contribution of dimers to oxidative deterioration was investigated by analyzing their volatile thermal decomposition products by capillary gas chromatography-mass spectrometry. Dimers were isolated by gel permeation chromatography from autoxidized linolenate and from the corresponding monohydroperoxides, cyclic peroxides and dihydroperoxides. Major volatile decomposition products identified from these oxidative dimers were similar to those formed from the corresponding monomeric hydroperoxides. However, dimers from linolenate hydroperoxides produced more propanal and methyl 9-oxononanoate than the corresponding monomers but less methyl octanoate and much less or no 2,4-heptadienal and 2,4,7-decatrienal. Significant differences in minor volatile products also were observed between dimeric and monomeric products of methyl linolenate oxidation compounds. Mechanisms are suggested for the formation of volatile decomposition products from different dimeric structures. These dimers are believed to be important sources of volatile compounds contributing to flavor and oxidative deterioration of fats.

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