Comparaison des effets nutritionnels de l'oléine de palme (huile de palme raffinée) à ceux de l'huile d'olive

Objectif : cette étude avait pour objectif de comparer les effets nutritionnels de l'oléine de palme à ceux de l'huile d'olive chez des rats.Méthodes : il s'agissait d'une étude expérimentale réalisée chez des rats Wistar mâles nourris avec un régime contenant 30% de lipides (oléine de palme et huile d'olive). Les rats avaient un libre accès à la nourriture et à l'eau. Après 12 semaines d'expériences, les animaux ont été sacrifiés et le sang aortique a été prélevé. Le plasma obtenu après traitement a été séparé en aliquotes qui ont servi au dosage des paramètres du profil lipidique (cholestérol total, triglycérides et HDL cholestérol); des paramètres du stress oxydant (SOD, GPx, TBARS, Thiols); de l'interleukine-6 et des transaminases (ALAT et ASAT).Résultats : Aucune différence significative n'a été observée entre l'huile d'Olive et l'Oléine de palme concernant les taux plasmatiques d'interleukine-6, de cholestérol total, de triglycérides, de HDL cholestérol, de GPx, des TBARS et des thiols. La consommation d'huile d'Olive a augmenté de façon significative l'activité de la SOD (p=0,0242) et l'activité de l'ALAT (p=0,0199).Conclusion : Cette étude a montré que la consommation de l'oléine de palme induit un profil lipidique non athéromateux et améliore le statut antioxydant

Blood-Brain Barrier Experiments with Clinical Magnetic Resonance Imaging and an Immunohistochemical Study

OBJECTIVE: The purpose of study was to evaluate the feasibility of brain magnetic resonance (MR) images of the rat obtained using a 1.5T MR machine in several blood-brain barrier (BBB) experiments. METHODS: Male Sprague-Dawley rats were used. MR images were obtained using a clinical 1.5T MR machine. A microcatheter was introduced via the femoral artery to the carotid artery. Normal saline (group 1, n = 4), clotted autologous blood (group 2, n = 4), triolein emulsion (group 3, n = 4), and oleic acid emulsion (group 4, n = 4) were infused into the carotid artery through a microcatheter. Conventional and diffusion-weighted images, the apparent coefficient map, perfusion-weighted images, and contrast-enhanced MR images were obtained. Brain tissue was obtained and triphenyltetrazolium chloride (TTC) staining was performed in group 2. Fluorescein isothiocyanate (FITC)-labeled dextran images and endothelial barrier antigen (EBA) studies were performed in group 4. RESULTS: The MR images in group 1 were of good quality. The MR images in group 2 revealed typical findings of acute cerebral infarction. Perfusion defects were noted on the perfusion-weighted images. The MR images in group 3 showed vasogenic edema and contrast enhancement, representing vascular damage. The rats in group 4 had vasogenic edema on the MR images and leakage of dextran on the FITC-labeled dextran image, representing increased vascular permeability. The immune reaction was decreased on the EBA study. CONCLUSION: Clinical 1.5T MR images using a rat depicted many informative results in the present study. These results can be used in further researches of the BBB using combined clinical MR machines and immunohistochemical examinations.

Intermediate production of mono- and diolein by an immobilized lipase from Candida antarctica

Lipase from Candida antarctica, fixed on macroporous acrylic resin, has been used for the intermediate production of mono- and diolein by hydrolysis of triolein. The effect of altering concentrations of triolein and glycerol and the function of the molecular sieve on the hydrolysis reaction of triolein were investigated. The highest hydrolysis yield was observed for the utmost concentration of triolein, which gave a hydrolysis optimum at the lower reaction time. Raising the concentration of triolein resulted in a 13.7 times increase in mono-and diolein during reaction period. Addition of glycerol to the reaction mixture had a considerably higher positive effect on the production of monolein than that of diolein. The use of a molecular sieve in the mixture was found to be the most effective environment tested, which demonstrated high activity and excellent selectivity toward the formation of intermediate monolein

Preparation of sustained release multivesicular liposome for thymopentin and preliminary study on its pharmacokinetics in rats / 药学学报

To optimize the formulation and preparation method of multivesicular liposome of thymopentin and to investigate its pharmacokinetics in rats, the multivesicular liposome of thymopentin was prepared by double emulsification method and the formulation was optimized by orthogonal design. The release characteristics of thymopentin from multivesicular liposome in PBS (pH 7.4) and in plasma were investigated. The multivesicular liposome of thymopentin labeled with fluorescein isothiocyanate was prepared by double emulsification method. Its pharmacokinetics was evaluated following intramuscular injection in rats. The optimal formulation of multivesicular liposome of thymopentin were formulated with 7.5% glucose in aqueous phase and 2.25 mol x L(-1) triolein, 2.68 mol x L(-1) DPPG and 16.96 mol x L(-1) DOPC in organic phase. The entrapment efficiency of the multivesicular liposome of thymopentin was above 85% and the mean particle size was about 22 microm. The in vitro release of thymopentin from multivesicular liposome in PBS (pH 7.4) and in plasma was found to be in a sustained manner. The release curves were fitted to Higuchi equation. The pharmacokinetics following intramuscular injection of the multivesicular liposome of thymopentin labeled with fluorescein isothiocyanate in rats showed that the peak concentration of thymopentin was lower and elimination of it was slower significantly than that of thymopentin labeled with fluorescein isothiocyanate solution in the same dose. The plasma concentration of thymopentin maintained above quantitative limitation at 120 h after administration of multivesicular liposome of thymopentin. The optimized formulation and preparation technology of multivesicular liposome of thymopentin with higher entrapment efficiency are feasible with good reproducibility. Multivesicular liposome of thymopentin showed significant sustained-release property following intramuscular injection in rats.

The Steroid Effect on the Blood-Ocular Barrier Change Induced by Triolein Emulsion as seen on Contrast-Enhanced MR Images

OBJECTIVE: The purpose of this study is to evaluate the effect of dexamethasone on the damaged blood-ocular barrier caused by triolein emulsion, using contrast-enhanced MR imaging. MATERIALS AND METHODS: An emulsion of 0.1-mL triolein in 20 mL of saline was infused into the carotid arteries of 32 cats, 12 cats were placed in the treatment group and 18 cats were placed in the Control group. Thirty minutes after the infusion of triolein emulsion, a set of orbital pre- and post-contrast T1-weighted MR images (T1WIs) were obtained. Infusion of 10 mg/kg dexamethasone into the ipsilateral carotid artery of each of the cats in the treatment group cats and 20 mL saline in each of the cats in the control group was given. A second set of pre- and post-contrast orbital T1WIs were obtained three hours following triolein emulsion infusion. Qualitative analysis was performed for the the anterior chamber (AC), the posterior chamber (PC), and in the vitreous humor of the ipsilateral and contralateral eyes. The signal intensity ratios of the ipsilateral eye over the contralateral eye were quantitatively evaluated in the three ocular chambers on the first and second set of T1WIs, and were then statistically compared. RESULTS: Qualitatively, the AC, the PC or the vitreous did not show immediate contrast enhancement on the first and the second set of post-contrast T1WIs. However, the AC and the PC showed delayed contrast enhancement for both groups of cats on the second pre-contrast T1WIs. No enhancement or minimally delayed enhancement was seen for the vitreous humor. Quantitatively, the signal intensity ratios in the PC of the treatment group of cats were statistically lower than the ratios of the control group of cats for the second set of T1WIs (p = 0.037). The AC and vitreous showed no statistically significant difference between the feline treatment group and control group (p > 0.05). CONCLUSION: Contrast-enhanced MR images revealed increased vascular permeability in the PC of the eye after infusion of triolein emulsion. Dexamethasone seems to decrease the breakdown of the blood-aqueous barrier in the PC.

Lipolysis of emulsion models of triglyceride-rich lipoproteins is altered in male patients with abdominal aorta aneurysm

Disorders of the lipid metabolism may play a role in the genesis of abdominal aorta aneurysm. The present study examined the intravascular catabolism of chylomicrons, the lipoproteins that carry the dietary lipids absorbed by the intestine in the circulation in patients with abdominal aorta aneurysm. Thirteen male patients (72 ± 5 years) with abdominal aorta aneurysm with normal plasma lipid profile and 13 healthy male control subjects (73 ± 5 years) participated in the study. The method of chylomicron-like emulsions was used to evaluate this metabolism. The emulsion labeled with 14C-cholesteryl oleate and ³H-triolein was injected intravenously in both groups. Blood samples were taken at regular intervals over 60 min to determine the decay curves. The fractional clearance rate (FCR) of the radioactive labels was calculated by compartmental analysis. The FCR of the emulsion with ³H-triolein was smaller in the aortic aneurysm patients than in controls (0.025 ± 0.017 vs 0.039 ± 0.019 min-1; P < 0.05), but the FCR of14C-cholesteryl oleate of both groups did not differ. In conclusion, as indicated by the triglyceride FCR, chylomicron lipolysis is diminished in male patients with aortic aneurysm, whereas the remnant removal which is traced by the cholesteryl oleate FCR is not altered. The results suggest that defects in the chylomicron metabolism may represent a risk factor for development of abdominal aortic aneurysm.

Temporary Opening of the Testis-blood Barrier by Triolein Fat Emulsion / 대한비뇨기과학회지

PURPOSE: Although the purpose of the blood-testis barrier (BTB) is to protect germ cells from harmful influences, it also impedes the delivery of chemotherapeutic agents to the testis. This study was undertaken to determine whether a triolein emulsion could transiently alter the permeability of the BTB in cats. MATERIALS AND METHODS: An emulsion of 0.05ml triolein in 20ml of saline or just 20ml of normal saline, as the control, were infused into the testicular arteries in 18 and 15 cats, respectively (embolic and control group). Pre- and post-contrast magnetic resonance images (MRIs) were obtained 30 minutes and 2 hours after embolization. Qualitative and quantitative analyses of the MRIs were performed via the presence and degree of contrast enhancement and the contrast enhancement ratios (CERs), respectively. An electron microscopy (EM) study was subsequently performed, using a lanthanum tracer, to correlate with the MRI results. RESULTS: Contrast enhancement of the testis was observed in both groups and at both time points, but was more prominent in the embolic group. The CERs in the embolic group were significantly higher than those in the control group (p=0.0001). In each group, the CERs at 2 hours were significantly lower than those at 30 minutes (p=0.006). In the EM study, the entry of lanthanum was markedly increased at 30 mins, but recovered at 2 hours after embolization compared to the control. CONCLUSIONS: Intra-arterial infusion of triolein emulsion transiently increased the permeability of the BTB. This result may be useful in future studies for a chemotherapy delivery system to the testis.

Experimental Model for Research on the Blood-Ocular Barrier

PURPOSE: The eyeball has 2 blood-ocular barriers, i.e., the blood-retinal and blood-aqueous barriers. The purpose of this study was to evaluate if triolein emulsion could disrupt the barriers, and we wanted to suggest as an experimental model for future blood-ocular barrier studies. MATERIALS AND METHODS: The triolein emulsion was made of 0.1 ml triolein and 20 ml normal saline, and this was infused into the carotid artery of ten cats (the experimental group). As a control group, only normal saline was infused in another ten cats. Precontrast and postcontrast T1-weighted MR images were obtained at 30 minutes and 3 hours after embolization in both groups. The signal intensities were evaluated qualitatively and quantitatively in the anterior and posterior chambers and also in the vitreus fluid. Statistical analysis was performed by employing the Kruskal Wallist test, Dunn's Multiple Comparison test and the Wilcoxon signed rank test. RESULTS: In the control group, no contrast enhancement was demonstrated in the anterior or posterior chamber or in the vitreus fluid of the ipsilateral or contralateral eyeball on the 30 minutes MR images. The anterior chambers of the ipsilateral and contralateral eyeballs revealed delayed contrast enhancement on the 3 hour MR images. In the experimental group, the 30 minute-postembolization MR images were not different from those of the control group. The 30 minute-postembolization MR images demonstrated delayed contrast enhancement in the anterior chamber of the ipsilateral and contralateral eyeballs and in the posterior chamber of the ipsilateral eyeball. The delayed contrast enhancement of the posterior chamber of the ipsilateral eyeball was statistically significant (p<0.05). CONCLUSION: The present study demonstrated significant contrast enhancement in the posterior chamber with infusion of the triolein emulsion, and this can serve as a model for blood-aqueous barrier studies.

Comparison of the CT and Pathologic Findings of Pulmonary Fat Embolism Induced by Triolein and Oleic Acid in Rabbits

PURPOSE: The aim of this study was to evaluate the CT findings of pulmonary fat embolism syndrome that was induced by triolein and oleic acid, along with its pathologic correlation. MATERIALS AND METHODS: 16 rabbits were included in this study. The rabbits in group I (n=8) were embolized with 0.2 mL triolein and the rabbits of group II (n=8) were embolized with 0.2 mL oleic acid through ear veins. HRCT scans were done prior to embolization and at 0.5, 4, 24, 48 and 72 hours post-embolization. The pathologic correlations were determined at 0.5, 24, 48 and 72 hours. RESULTS: At 24 hours, one group I rabbit showed abnormal CT findings that were composed of several 2-3 mm nodules and multiple ill-defined peripheral ground glass opacities. The pathologic finding of this rabbit at 48 hours was mainly intraarveolar edema. All the group II rabbits (n=8/8) showed ill-defined bilateral and peripheral ground glass opacities with (n=6/8) or without consolidations (n=2/8) on the 0.5 hour CT. All the rabbits (n=7/7) showed that the new ground glass opacities and ground glass opacities noted on the 0.5 hour CT were changed into consolidation. The margins of the ground glass opacities and consolidations were more sharpened on the 24 hours CT. All 6 rabbits (n=6/6) showed consolidations without ground glass opacities and the margins of the consolidations were more sharpened on the 48 hours CT. There was no significant interval change on the 72 hours CT. The pathologic findings of ground glass opacities were interstitial edema or mild intraalveolar edema. The pathologic findings of consolidation were intraalveolar edema, hemorrhage and coagulation necrosis. CONCLUSION: The CT findings after fat embolization using triolein and oleic acid were ill-defined peripheral ground glass opacities with/without consolidations. These findings occurred in only one triolein group with the time lag, but these findings were immediately and extensively seen in all group II rabbits. These CT findings may be important for making a diagnosis of pulmonary fat embolism syndrome.

Magnetic Resonance Imaging and Histologic Findings of Acute and Subacute Stage of Experimental Cerebral Fat Embolism in Cats

PURPOSE: To determine the magnetic resonance imaging (MRI) findings and natural history of cerebral fat embolism in a cat model, and to correlate the MRI and histologic findings. MATERIALS AND METHODS: Using the femoral arterial approach, the internel carotid artery of 11 cats was injected with 0.1 ml of triolein. T2-weighted (T2WI), T1-weighted (T1WI) and Gd-enhanced T1-weighted (Gd-T1WI) images were obtained serially at 2 hours, 1 and 4 days and 1, 2 and 3 weeks after embolization. Any abnormal signal intensity (SI) was evaluated. After MR imaging at 3 weeks, brain tissue was obtained for light microscopic (LM) examination using hematoxylin-eosin and Luxol fast blue staining, and for electron microscopic (EM) examination. The histologic and MRI findings were correlated. RESULTS: At 2 hours, lesions showed high SI at T2WI, iso- or low SI at T1WI, and strong enhancement at Gd-T1WI. The high SI seen at T2WI decreased thereafter, and most lesions became iso-intense. At week 3, however, small focal areas of high SI were seen in the grey matter of eight cats and in the white matter of three. The low SI noted at acute-stage T1W1 subsequcntly became normal, though in the areas in which T2W1 had depicted high SI, focal areas of low SI remained. Lesion enhancement demonstrated by Gd-T1WI decreased continuously from day 1, and at week 3, weak enhancement was seen at the margin of the remained hypointense lesions in the gray matter in five cats. At LM examination with hematoxylin-eosin staining revealed normal histologic findings in the greater park of an embolized lesion. Cystic change was observed in the gray matter of eight cats, and in the gray and white matter of three of the eight. At LM examination, Luxol fast blue, staining demonstrated demyelination around the cystic change occurring in the white matter, and EM examination of the embolized cortex revealed sporadic intracapillary fat vacuoles (n=11) and disruption of the blood-brain barrier (n=4). Most lesions were normal, however, and perivascular interstitial edema and cellular swelling were mild compared with the control side. CONCLUSION: Experimental cerebral fat embolism was clearly demonstrated by T2WI and Gd-T1WI images obtained at all time points. The greater part of an embolized lesion showed reversible findings at MR and histologic examination; irreversible focal necrosis was, however, observed in gray and white matter at week 3.

Lipasa hepática: efectos sobre el metabolismo lipídico y lipoproteico / Hepatic lipase: its effects on lipids and lipoproteins metabolism

La Lipasa Hepática (LH) es una enzima de síntesis y localización principalmente hepática. Como triglicérido hidrolasa y fosfolipasa interviene en la transformación de la lipoproteína de densidad intermedia (IDL) en lipoproteína de baja densidad (LDL) y en el catabolismo de la lipoproteína de alta densidad (HDL). Además actúa como ligando entre las lipoproteínas y distintos receptores de la superficie celular, en el catabolismo lipoproteico. En los últimos años, el estudio del polimorfisismo de su gen promotor (LIPC), ha esclarecido el comportamiento de la LH en diferentes situaciones metabólicas. Para la medida de su actividad, se validaron las condiciones finales del ensayo: sustrato de trioleína, sonicado en presencia de albúmina, en buffer Tris-HCl pH=9, con lisolecitina como emulgente, incubado en presencia de plasma post-heparínico. La actividad de la LH se encuentra bajo control hormonal; una disminución en su actividad genera un cuadro aterogénico, con hiperlipemia combinada y presencia de lipoproteínas aterogénicas. Por otro lado, un aumento marcado de LH, produce disminución de HDL y presencia de LDL pequeñas y densas. En este trabajo, se presentan los papeles lipolítico y no lipolítico de la LH, así como distintos factores que regulan su actividad y por lo tanto, su intervención en el proceso aterogénico

Diagnóstico por laboratorio del síndrome de absorción intestinal deficiente de origen intestinal / Diagnosis by laboratory in malabsorption syndrome-intestinal source

La absorción y digestión de alimentos se efectúa en una forma ordenada. En las porciones proximales del intestino delgado, las enzimas pancreáticas y la bilis convierten sustancias complejas en productos simples que por diversos mecanismos pasan la pared del enterocito y son transportados a través de la linfa y la circulación portal. El síndrome de absorción intestinal deficiente (SAID) puede ser secundario a enfermedades que alteran la digestión, la absorción, o ambas. En este trabajo revisamos las pruebas de laboratorio útiles para establecer un diagnóstico de SAID de origen intestinal, enfatizando aquellas, que se realizan en nuestro medio. Finalmente, proponemos una estrategia de diagnóstico que toma en cuenta las principales causas de SAID en México.

Experimental Study on Fat Absorption (I131-Triolein) from the Parasite Infected Intestine

The effects of Clonorchis sinensis, Hymenolepis nana and Toxocara canis infection on fat absorption in the intestine were studied. For this purpose, I131-Triolein was given to the animals which were infected by those parasites, and amounts of the excretion in the feces were counted and following results were obtained. In the Clonorchis sinensis infected group, the excretion of Triolein was increased to 4. 10~4.49% compared with that of the control group. In the Hymenolepis nana infected group, the excretion of Triolein was increased to 4~5% compared with that of control group. In the Toxocara canis infected group, the excretion was about twice as much as that of the control group. It is concluded that parasite infection in digestive system diminishes fat absorption in gastrointestinal tract of the host.