Mannose-6-Phosphate/Insulin-Like Growth Factor 2 Receptor (M6P/IGF2-R) in Growth and Disease: A Review

This work aims to summarize the current knowledge about Mannose-6- Phosphate/Insulin-like Growth Factor 2 Receptor (M6P/IGF2-R) in the regulation of growth and development, and its involvement in tumor progression. M6P/IGF2-R binds both molecules sharing M6P signals and IGF2. The studies showed that M6P/IGF2-R is involved in the trafficking of mannnose-6-phosphorylated enzymes from the Trans-Golgi Network (TGN) to lysosomes and the uptake of secreted proenzymes from the plasma membrane to the lysosomes via clathrin-coated vesicles for their maturation. The M6P/IGF2-R acts as a scavenger that binds IGF2 and transports it to lysosomes for its degradation since IGF2 exerts its biological effects on cell proliferation and development by binding with lower affinity on IGF1 receptor, which is structurally similar to insulin receptor and different from the M6P/IGF2-R. The M6P/IGF2-R has also been studied in human cancer, and frequent losses of heterozygosity (LOH) at the 6q25-27 gene region with mutations in the remaining allele have been described. These results led to consider M6P/IGF2-R gene as a putative tumor suppressor and its potential prognostic value has been suggested

Nutritional properties of enriched local complementary flours

Abstract: This study aimed to identify the nutritional, functional, sensory and microbiological profile of experimental nutritional flours, produced with local products in Burkina Faso. The raw materials included maize (Zea mays), millet (Pennisetum glaucum) and rice (Oryza sativa). Local ingredients were pulps of Adansonia digitata and Parkia biglobosa and seeds of Cucurbita maxima and Moringa oleifera. Three formula were developed, the first (F1) with maize, the second (F2) with rice and the last (F3) with millet. Each of these cereals was mixed with predetermined portions of seeds and pulps in order to obtain enriched flour. Nutritional, microbiological and functional analysis and the acceptability criteria of these enriched flours were assessed and compared to Misola (F4), the existing local complementary flour. The fat content of experimental flours were respectively in the first (F1), second (F2) and third formula (F3) 15.91±0.01%, 11.82±0.02% and 17.02±0.02%. The carbohydrate range was 65.46±0.06%, 70.81±0.01% and 64.51±0.01% for F1, F2 and F3, while the energetic value is higher than recommended (453.07±0.05, 424.56±0.03 and 458.96±0.05 kcal respectively for F1, F2 and F3). Functional characteristics indicated the good viscosity (117, 119 and 121 mm/30 sec for F1, F2 and F3) least gelation (9, 6 and 7%) and water absorption capacity (2, 4 and 1 g/g). Trained sensory evaluation panellists gore the enriched flour porridge a score of acceptable. These enriched flours have great potential as a weaning food in resource-poor and technologically under-developed countries

Should digestion assays be used to estimate persistence of potential allergens in tests for safety of novel food proteins?

Food allergies affect an estimated 3 to 4% of adults and up to 8% of children in developed western countries. Results from in vitro simulated gastric digestion studies with purified proteins are routinely used to assess the allergenic potential of novel food proteins. The digestion of purified proteins in simulated gastric fluid typically progresses in an exponential fashion allowing persistence to be quantified using pseudo-first-order rate constants or half lives. However, the persistence of purified proteins in simulated gastric fluid is a poor predictor of the allergenic status of food proteins, potentially due to food matrix effects that can be significant in vivo. The evaluation of the persistence of novel proteins in whole, prepared food exposed to simulated gastric fluid may provide a more correlative result, but such assays should be thoroughly validated to demonstrate a predictive capacity before they are accepted to predict the allergenic potential of novel food proteins

Current challenges facing the assessment of the allergenic capacity of food allergens in animal models

Food allergy is a major health problem of increasing concern. The insufficiency of protein sources for human nutrition in a world with a growing population is also a significant problem. The introduction of new protein sources into the diet, such as newly developed innovative foods or foods produced using new technologies and production processes, insects, algae, duckweed, or agricultural products from third countries, creates the opportunity for development of new food allergies, and this in turn has driven the need to develop test methods capable of characterizing the allergenic potential of novel food proteins. There is no doubt that robust and reliable animal models for the identification and characterization of food allergens would be valuable tools for safety assessment. However, although various animal models have been proposed for this purpose, to date, none have been formally validated as predictive and none are currently suitable to test the allergenic potential of new foods. Here, the design of various animal models are reviewed, including among others considerations of species and strain, diet, route of administration, dose and formulation of the test protein, relevant controls and endpoints measured

Effet de l'hétérogénéité diélectrique sur un brin métallique à 915 MHz

The effect of window in the external dielectric surrounding a wire is examined by means of two approach methods. The first method yields analytical results but ignores the singularities in the dielectric to achieve this result. The second method integrates the singularities of the field in the window and yields a final result by means of numerical computations. The two methods are complementary and compatible, then they give results which are near to each other for the propagation constant. The second method is adapted to the best result of a given technical situation. This study has put in light that a window in the dielectric sheath locally increases the electric near field.This result can be used in hyperthermical applications in biology and in medecine, so the way to technological transferts are openedL'influence d'une discontinuité sous forme d'une fenêtre dans la gaine diélectrique entourant un brin métallique a été examinée à l'aide de deux méthodes approchées de calcul. La première méthode fournit des résultats analytiques mais la complexité des équations oblige à ignorer les singularités diélectriques ; la seconde méthode de simulation numérique permet la prise en compte des singularités de champ électrique dans la fenêtre mais elle n'est pas bien adaptée au calcul des impédances. Ces deux méthodes sont complémentaires et compatibles, car elles donnent des valeurs voisines des paramètres de propagation. La deuxième méthode parait mieux adaptée à la recherche d'une meilleure solution technique pour un besoin donne. D'autre part, cette étude a montré un renforcement localisé du champ du à la présence de la fenêtre, ce qui laisse augurer des applications hyperthermiques de génie biologique et médica

Effets de l'ingestion de l'alginate ou du carraghénate de sodium associés à la farine de soja ou à la caséine sur la disponibilité des protéines et les lipides plasmatiques du rat

Non disponible / Not availableDe faibles doses d'alginate ou de carraghénate de sodium ont été incorporées dans des régimes à base de soja ou de caséine, le tout étant chauffé. Alors que l'addition de l'alginate dans le soja a été sans effet, celle du carraghénate a provoqué une diminution de la digestibilité protéique et un retard de croissance persistant chez le rat. La supplémentation en méthionine des régimes contenant le carraghénate de sodium a supprimé ces effets. La digestion in vitro des échantillons de farine de soja ou de caséine a montré une inhibition de la protéolyse de ces dernières lorsque celles-ci contenaient le carraghénate de sodium. La présence de carraghénate de sodium dans les régimes a diminué le taux de triglycérides plasmatiques des animaux tout en étant sans effet sur le cholestérol

Interactions between β-lactoglobulin and pectins during in vitro gastric hydrolysis

International audienceThis paper deals with the influence of different levels of three pectins, low-methylated pectin (LMP), high-methylated pectin (HMP), and low-methylated and amidated pectin (LMA), on the in vitro gastric hydrolysis of â-lactoglobulin (â-lg). Proteolysis by pepsin consisted of a 2-h progressive reduction of pH. A turbidity measurement of â-lg-pectin mixtures was carried out during the proteolysis. The influence of pectins on pepsin enzymatic activity was also evaluated. â-Lg was resistant to peptic digestion. The presence of each of the three pectins at a concentration of 50 wt % increased the N release at all pH values considered, despite a significant inhibition of the pepsin enzymatic activity with the pectins. The turbidity of â-lg solutions during proteolysis was reduced by the addition of pectins, because of the formation of electrostatic complexes between this protein and pectins. The increase of N release could be a false positive result due to the difficulty of precipitating protein by trichloroacetic acid because of the formation of electrostatic complexes demonstrated by the decrease of turbidity

Effets des alginates et des carraghénates de sodium associés aux protéines de soja sur le coefficient d'efficacité protéique (CEP)

International audienc

Acid-formed pectin gel delays major incomplete kiwi fruit allergen Act c 1 proteolysis in in vitro gastrointestinal digestion

BACKGROUND: It is thought that food sensitisers must be able to reach the intestine in order to sensitise patients. Pectin is a gel-forming plant polysaccharide that can protect allergens from in vivo gastric digestion and in vitro pepsin digestion. The aim of this study was to examine if pectin gel formed in the acidic environment of the stomach can protect labile allergen from in vitro gastrointestinal digestion. RESULTS: Pectin forms a gel in the acidic conditions of gastric fluid up to a concentration of 1.0 +/- 0.14 g L(-1). Four allergenic fruits (kiwi, cherry, apple and banana) form gels in the same manner at the dilutions 14.8 +/- 0.4; 8.4 +/- 0.2, 9.4 +/- 0.35 and 29.1 +/- 0.2, respectively. The time necessary for dissolution of 50 g L(-1) pectin gel in intestinal fluid was found to be 70 +/- 0.2 min. Pectin gel formed in situ was able to protect Act c 1 from pepsin digestion for 1 h and from further intestinal digestion for one additional hour. CONCLUSION: Pectin gel in an acidic environment protects Act c 1 from pepsin digestion and dissolves slowly in the slightly basic environment of the intestine allowing the survival of fruit allergen for additional time and possible interaction with the gut immune system. (C) 2008 Society of Chemical Industr