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A R Eynard

Publications and source records attributed to A R Eynard.

At least 37 records · Page 2Linked to original sources
PubMed1999

Differential effects of dietary Oenothera, Zizyphus mistol, and corn oils, and essential fatty acid deficiency on the progression of a murine mammary gland adenocarcinoma.

The modulating effect of dietary enrichment in mistol seed oil (MO) containing 25% of alpha-linolenic acid (ALA), evening primrose oil (EPO) enriched in gamma-linolenic acid (GLA) and corn oil (CO) as sources of omega-6 and omega-9 fatty acids on the growth parameters of one transplantable mammary tumor were compared. Mice fed on different lipid formulae were inoculated with a mammary gland adenocarcinoma and different growth development tumor parameters were recorded. Results showed that corn oil feeding slowed down most of the tumor growth parameters, as did the EPO diet. MO also showed antitumor activity. Olein feeding, which induces an essential fatty acid deficiency (EFAD), increased the incidence and the multiplicity of metastases when compared with the controls. It may be concluded that a diet enriched in omega-6 fatty acids did not behave as a tumor promoter in this mammary gland tumor model. The antitumor activities of EPO and MO are corroborated in present experiments, suggesting that both oils may be of value in nutritional approaches of mammary gland tumor therapies. In addition, present data add further experimental proof about the proposed protumorigenic proneness induced by the EFAD state.

Adenocarcinoma↗
PubMed1999

N-3, n-6 and n-9 dietary fatty acids modulate the growth parameters of murine salivary gland tumors induced by dimethylbenzanthracene.

Variations in dietary fatty acid composition influence the biological behaviour of certain tumours. Diets enriched with oleic acid (18:1 n-9) seem to promote tumour progression on several lines due perhaps to the development of essential fatty acid deficiency (EFAD), whereas n-3 fatty acids have a protective effect. Since the role played by lipids on salivary gland tumorigenesis has not yet been studied, an experimental model is presented. BALB/c mice were fed on four different diets: control, corn oil, fish oil and olein groups. Salivary gland adenocarcinomas were chemically induced by using 9,10-dimethyl-1,2-benzanthracene. Animals were sacrificed at the 20th post-injection week and several tumour parameters were analysed. Linoleic acid showed no promoting activity. Tumour size was larger in the olein group than in fish oil fed mice, indicating that the oleic acid, linked to the induced EFAD condition, has a protumorigenic activity whereas n-3 polyunsaturated fatty acids appear to exert a protective effect.

9,10-Dimethyl-1,2-benzanthracene↗
PubMed1998

Quercetin enhances pretumorous lesions in the NMU model of rat pancreatic carcinogenesis.

The effect of dietary quercetin (Q) was evaluated in rats treated with nitrosomethylurea (NMU). Pancreatic nodules and focal acinar cell hyperplasias were observed in groups treated with NMU (87%) and Q-NMU (100%). Although rats with dysplastic foci (27%) were found in the NMU-treated group, Q-NMU treatment resulted in a significantly higher number of rats with dysplastic foci (73%). Furthermore, carcinomas in situ (12%) and one microcarcinoma (4%) were found in these animals. Mitosis was significantly increased and apoptosis was diminished in focal acinar cell hyperplasias of the Q-NMU group. Our present results support a promoting and progressing effect of quercetin in the NMU model of rat pancreatic carcinogenesis.

Animals↗
PubMed1998

Differential modulation by dietary n-6 or n-9 unsaturated fatty acids on the development of two murine mammary gland tumors having different metastatic capabilities.

It is widely known that dietary lipids can modify the ability of different cancers to grow up and metastasize, especially mammary gland tumors. However, it is still unclear whether n-6 fatty acids behave as tumor promoters in this gland cell population. The effect of different nutritional polyunsaturated fatty acids (PUFAs) on tumor growth parameters of two transplantable murine mammary gland adenocarcinomas of low and high metastatic ability was tested on hosts fed diets with corn oil (CO) rich in 18:2n-6, evening primrose oil (EPO) containing 18:3n-6 (GLA) and a third formula supplemented with olein (O) 18:1n-9, which induces an essential fatty acid deficiency (EFAD). Tumor growth parameters were not adversely affected in the corn oil group with respect to stock-fed controls. Furthermore, metastatic spreading diminished in this group. EPO showed a moderate antitumor activity whereas the n-9-enriched diet showed no clear-cut effects. In both mammary gland tumors, n-6 fatty acid-rich lipids formulae, containing GLA and linoleic acid, were not tumor promoters. On the contrary, both exhibited anticancer activity.

Adenocarcinoma↗
PubMed1998

Lipid and fatty acid composition of different fractions from rat urinary transitional epithelium.

The phospholipid composition of rat urinary transitional epithelium (TE) and the fatty acid composition of microsomal, mitochondrial, cytosolic, and plasma membrane (PM) subcellular fractions were investigated. PM marker enzymes and electron microscopy analysis were used to characterize the PM fraction, which showed a distinctive lipid composition compared to the general profile of PM from different sources. The levels of cholesterol and sphingomyelin were not enriched in the PM fraction; on the other hand, the increased amounts of glycosphingolipids and phosphatidylserine, and the decreased level of phosphatidylcholine followed the general features of a PM profile. This differential PM lipid composition may reflect the unique morphology of this mammal TE, consisting of concave plaques with an asymmetrical membrane unit. The distribution of the double bond across the PM indicated a higher unsaturation of the inner relative to the outer part of the PM hemileaflet. In addition, the presence of 20:3n-9 nonessential fatty acid in a normal TE may represent a characteristic fatty acid metabolism of this epithelium.

Animals↗
PubMed1998

Is the risk of urinary tract tumorigenesis enhanced by a marginal chronic essential fatty acid deficiency (EFAD)?

A considerable amount of experimental, clinical and epidemiological data indicate that dietary fats play a role in urinary tract tumorigenesis. In rodents, chronic essential fatty acid (EFA) deficiency seems to induce both urolithiasis and transitional hyperplasias, followed by a tendency for tumorigenesis of the urinary passages. High intake of saturated fats or non-EFAs, conditions that may induce EFA deficiency (EFAD) increase the risk of bladder cancer in case-control studies. In other cell populations, EFAs are beneficial as preventive and therapeutic nutrients for the treatment of cancer. Thus, it is reasonable to assume that abnormal metabolism and/or nutritional deprivation of EFA, by inducing a chronic or a subclinical EFA deficiency, may enhance the risk of urothelial tumorigenesis.

Epithelium↗
PubMed1998

Morphological and biological characterization of two mesenchymal murine tumors and the modulation of their growth parameters by n-3 and n-6 polyunsaturated fatty acids.

Certain tumor growth parameters (GP) of two mesenchymal transplantable tumors maintained on C57BL/6J mice were characterized. Considering that many experimental, clinical and epidemiologic data have indicated that n-3 and n-6 essential fatty acids are nutrients which may delay the development as well as improve the course of cancer, GPs were evaluated on hosts fed on a semisynthetic formula containing 5% of corn oil (CO) or cod liver oil (CLO) and stock diet (C group). Although survival and latency time of tumor-bearing mice were shortened, other GP as percentage of successful implants were improved by both oils in sarcoma-bearing hosts, suggesting that n-3 and n-6 fatty acids might play a modulating role for the development of these tumors.

Animals↗
PubMed1998

Eicosatrienoic acid (20:3 n-9) inhibits the expression of E-cadherin and desmoglein in human squamous cell carcinoma in vitro.

Eicosatrienoic acid (ETA 5,8,11, n-9) is abnormally increased by essential fatty acid deficiency (EFAD), a condition associated with alterations of cell proliferation and differentiation. In comparison to certain EFAs, addition of ETA at a low concentration resulted in a reduction in the expression of the cell-cell adhesion molecule, E-cadherin, and to a lesser degree, of desmoglein, along with increased invasion of Matrigel by human squamous cell carcinoma (SCC) cells in vitro. At higher concentrations, ETA stimulated the growth of SCC cells. As previously shown, n-6 EFAs (mainly 18:3 n-6, GLA), up-regulated the expression of E-cadherin and desmoglein. This is the first report showing that the abnormal 20:3 n-9 (Mead's acid) is a down regulator of antimetastatic E-cadherin and desmoglein expression.

8,11,14-Eicosatrienoic Acid↗
PubMed1998

Alcohol, methylxanthine-containing beverages, and colorectal cancer in Córdoba, Argentina.

The relationship between social class indicators, body mass index (BMI), selected life-style habits (alcohol, coffee, maté and tea drinking) and colorectal cancer was investigated in a case-control study conducted between 1993 and 1997 in Córdoba, Argentina, a relatively high mortality area of colorectal cancer. Cases were 190 patients below age 80 years with incident, histologically confirmed colorectal adenocarcinomas, and controls were 393 patients admitted to hospital for a wide spectrum of acute, non-neoplastic disorders. Higher social class, based on occupation of the head of the household, was significantly associated with colorectal cancer risk: the odds ratios (OR) and 95% confidence intervals (95% CI) were 1.9 (1.2-2.9) for intermediate and 2.0 (1.2-3.4) for the highest as compared to the lowest social class individuals. When compared with subjects whose BMI was < 25 kg/m2, the OR was 1.1 (0.7-1.6) for those with BMI 25 to 29 kg/m2, and 1.3 (0.7-2.3) for those > or = 30. In comparison with alcohol abstainers, the OR was 2.8 (1.6-5.1) for drinkers, and there was a significant trend in risk with dose. The association was observed with wine (the most common alcoholic beverage in Argentina), as well as for beer and spirits. The consumption of coffee, maté and tea was not significantly related to colorectal cancer, but the ORs were below unity (0.9 (0.7-1.3) for coffee, 0.9 (0.6-1.2) for maté and 0.8 (0.6-1.2) for tea drinkers). The relationship between social class, alcohol drinking and colorectal cancer were consistent across strata of sex and age. This study confirms that colorectal cancer has positive social class correlates. The association with alcohol drinking is apparently stronger than previously reported, and may be due to the role of chance and/or peculiar correlates of alcohol drinking in this Argentinean population.

Adult↗
PubMed1997

Does chronic essential fatty acid deficiency constitute a pro-tumorigenic condition?

Many experimental, clinical and epidemiological data indicate that n-3 and n-6 essential fatty acids are therapeutic nutrients which may delay the development as well as improve the course of cancer. The present hypothesis correlates well with these data and it is proposed that chronic essential fatty acid deficiency, when coexisting with chronic hyperproliferative states (hyperplasias) and de-differentiation (dysplasias) both acting synergistically, may constitute a pro-tumorigenic situation. Evidence showing that, indeed, these hyperproliferative states are consistently reported in essential fatty acid deficiency in many species, including humans, in malpighian layers of skin and the upper alimentary and urinary tracts, among others, is discussed.

Animals↗
PubMed1997

Proaggregatory and procoagulant properties of three murine mammary gland tumor cell lines with different metastatic capabilities.

We have investigated the in vitro proaggregatory and procoagulant properties of three murine tumor cell lines having different metastatic potentials. The characterization was carried out with appropriate procoagulant inhibitors and plasma deficient in factors VII and X. The proaggregatory properties of M2, M3 and MM3 cell lines increased according to their metastatic potentials. Their procoagulant activity were dependent on factor X. The prothrombotic abilities exhibited by neoplastic cells (NC), acting synergistically, might play a role in cancer dissemination.

Adenocarcinoma↗
PubMed1997

Dietary deficiency or enrichment of essential fatty acids modulates tumorigenesis in the whole body of cobalt-60-irradiated mice.

The effect of dietary polyunsaturated fatty acids (PUFAs) on whole body-induced tumorigenesis was assayed in mice fed on essential fatty acid sufficient (EFAS) or essential fatty acid deficient (EFAD) diets following cobalt-60 irradiation. Four groups of mice were maintained, one on a control stock diet and three on experimental diets: a) without added fat (fat free, FF); b) containing 5% olein (O), rich in n-9; and c) containing 5% corn oil, rich in n-6 EFA (CO). Only mice fed on FF or O diets showed clinical and biochemical signs of EFAD. Total incidence of tumors showed an increase in FF (P < 0.02) and O (P < 0.03) mice. Tumors developed mostly in the liver in each of the EFAD groups (P < 0.001). Slight promoting activity on lung tumorigenesis was recorded in the CO group when this parameter was compared in EFAD and EFA sufficient mice. It may be concluded that, when a tumor initiator injures the body as a whole, EFAD, achieved either through a fat-free or an oleic-supplemented diet, behaves as a general promoting condition for tumorigenesis. The borderline tumorigenic effect of n-6 corn oil on the lungs suggests that this effect, when present, is target specific.

Animals↗
PubMed1997

[Composition of saturated and unsaturated fatty acids of foods frequently consumed in Argentina].

The composition of food lipid, including total lipids, saturated, monosaturated, and polyunsaturated fatty acids was analysed in this study. Foods, which were frequently consumed in Argentina and include in this study were: lean and fatty red meats, "ossobucco" with or without bone marrow, lean and skinned chicken meager and fatty fish, several sausages (salami and blood sausage), several crackers, hand-made fatty bread, fried and baked biscuits, ice cream, milk-marmelade, edible oils and bovine tallow. The content of fatty acids grouped according to their families in the food and description of the formulation of each food are given in the current paper. The glossary will help to identify the preparation of foods and will be beneficial for the people in other countries of Latinoamérica.

Argentina↗
PubMed1995

Effects of dietary n-3, n-6 and n-9 polyunsaturated fatty acids on benzo(a)pyrene-induced forestomach tumorigenesis in C57BL6J mice.

The modulating effect of dietary polyunsaturated fatty acids (PUFAs) on benzo(a)pyrene-induced forestomach tumorigenesis was assayed in mice fed with corn oil (CO), olein (O), Zizyphus mistol seed oil (MO), cod liver oil (CLO), and mixed fat (Stock diet). The fatty acid composition of liver lipids correlated well with the fatty acid composition of each diet. Only mice fed the O diet showed biochemical and clinical evidences of essential fatty acid deficiency (EFAD). Only 3 animals developed well-differentiated invading squamous cell carcinomas in the O group. The papilloma incidence was reduced in MO and CLO with respect to the O group. Forestomach papillomatosis was increased in mice fed an n-9 enriched diet in comparison to stock and CO groups. In comparison with stock mice, the frequency of multiple epidermoidal hyperplasia (MEH) was significantly decreased in the CLO group. Animals fed n-3 enriched diets (MO and CLO) showed significant antipromoting effect. These findings indicate that dietary fat can modulate tumorigenesis initiated in mouse forestomach by benzo(a)pyrene. In addition, the lack of action of an n-6 fatty acid-enriched diet in our experimental model suggests that the effect of PUFAs on tumorigenesis has target-tissue specificity. Mistol seed oil might be of potential value as a natural vegetable antipromoter nutrient.

Animals↗
PubMed1995

Protective capability of dietary Zizyphus mistol seed oil, rich in 18:3, n-3, on the development of two murine mammary gland adenocarcinomas with high or low metastatic potential.

The modulating effect of dietary Zizyphus mistol seed oil, rich in the n-3 polyunsaturated fatty acid alpha-linolenic acid, on two murine mammary gland adenocarcinomas having low (M2) and high (MM3) metastatic abilities was investigated. Following tumor subcutaneous inoculation, 165 BALB/c mice were fed on a semisynthetic diet containing 5% of mistol oil which has 25% of 18:3, n-3 (mistol group). The other group received a stock diet (C group). Tumor growth parameters such as success of tumor implants (ST), latency time (LT), tumor growth (TG), tumor volume (TV), survival, and number and sites of metastases were recorded. Fatty acid profiles of liver lipids correlated well with dietary fatty acids, with a n-3/n-6 ratio of 0.90:1 in the mistol group against 0.24:1 in the C group. None of the tumor growth parameters were worse in the mistol group with respect to the controls. On the contrary, survival in M2 hosts and tumor weight in MM3-bearing mice were significantly ameliorated. A tendency towards a diminution of total number of metastases in both types of tumor was observed in the mistol group. From these results, it is suggested that Z. mistol seed oil may be of potential value in nutritional oncology.

Adenocarcinoma↗
PubMed1994

Isologous and heterologous platelet aggregation induced by tumor cells from three murine mammary gland adenocarcinomas with different metastatic abilities.

The addition of neoplastic cells (NC) isolated from murine mammary gland adenocarcinomas having moderate and high metastatic ability on in vitro heparinized mice platelet rich plasma (PRP) induced platelet aggregation. One non-metastatic line did not induce aggregation. The aggregatory effect was not correlated with the metastatic abilities. None of the three types of tumors did cause aggregation on whole blood or PRP of rats. These adenocarcinomas seem to be suitable models to study in vitro the interactions between platelets and tumor cells having metastatic and non-metastatic potentials.

Adenocarcinoma↗
PubMed1993

Platelet factors induce chemotactic migration of murine mammary adenocarcinoma cells with different metastatic capabilities.

The chemotactic response of neoplastic cells (NC) induced by soluble platelet factors was investigated. NC suspensions isolated from murine mammary gland adenocarcinomas having different metastatic capabilities were incubated in Boyden's chambers and challenged with (1) 'Early Platelet Factors' (EP), obtained from the soluble fraction of recently collagen-activated human platelets, and (2) 'Late Platelet Factors' (LP), isolated after 24 hours incubation of the platelet aggregates. Chemotaxis was expressed as the distance travelled by NC through nitrocellulose filters. NC isolated from M3, the tumour line having the stronger metastatic potential, showed a significant chemotactic response towards LP factors, whereas NC from the M2 line exhibiting the lower metastatic behaviour, showed a chemotactic response towards EP factors. Both tumour cell lines lacked motion capability towards the well known chemoattractant peptide N-f-Met-Leu-Phe-Phe as well as to serum, plasma, collagen type I or culture medium. The different chemotactic response of both tumour lines when they were challenged by concentration gradients of factors released by early or late collagen-activated human platelets, confirm a relationship between platelet activity and metastatic capabilities and suggests that platelet chemoattractants might play a role in the metastatic dissemination of these mammary gland adenocarcinomas.

Adenocarcinoma↗