Loss of heterozygosity and microsatellite instability in de novo versus ex-adenoma carcinomas of the colorectum

Small adenocarcinomas of the colorectum showing no evidence of origin from an adenoma have been called de novo carcinomas, a name that implies an origin via a different molecular genetic mechanism than the usual colorectal carcinoma which develops from an adenoma. Using microsatellite analysis, 35 early (pT1) de novo and 36 pT1 ex-adenoma carcinomas were compared using 8 microsatellite loci at 6 different chromosomal loci (1p, 2p, 8p, 5q, 17p, and 18q) known or hypothesized to be important for colorectal carcinogenesis. The rate of loss of heterozygosity (LOH) at the 17p locus (near the p53 gene) was significantly higher in the de novo than in the ex-adenoma group (73 vs. 37%, P = 0.004). The rates of LOH at the other loci (including the APC and DCC genes) and the rate of MSI were not significantly different in the two groups. These results indicate that de novo carcinomas of the colorectum develop via a similar carcinogenetic pathway as conventional ex-adenoma carcinomas; however, their higher rate of LOH at 17p is evidence for a biologically more advanced lesion with more frequent p53 mutations, consistent with clinicopathological data indicating that de novo carcinomas are more aggressive than ex-adenoma carcinomas.     

Inventory on the dietary assessment tools available and needed in africa: a prerequisite for setting up a common methodological research infrastructure for nutritional surveillance,research, and prevention of diet-related non-communicable diseases

Objective: To carry out an inventory on the availability, challenges, and needs of dietary assessment (DA) methods in Africa as a pre-requisite to provide evidence, and set directions (strategies) for implementing common dietary methods and support web-research infrastructure across countries. Methods: The inventory was performed within the framework of the “Africa's Study on Physical Activity and Dietary Assessment Methods” (AS-PADAM) project. It involves international institutional and African networks. An inventory questionnaire was developed and disseminated through the networks. Eighteen countries responded to the dietary inventory questionnaire. Results: Various DA tools were reported in Africa; 24-Hour Dietary Recall and Food Frequency Questionnaire were the most commonly used tools. Few tools were validated and tested for reliability. Face-to-face interview was the common method of administration. No computerized software or other new (web) technologies were reported. No tools were standardized across countries. Conclusions: The lack of comparable DA methods across represented countries is a major obstacle to implement comprehensive and joint nutrition-related programmes for surveillance, programme evaluation, research, and prevention. There is a need to develop new or adapt existing DA methods across countries by employing related research infrastructure that has been validated and standardized in other settings, with the view to standardizing methods for wider use.     

Permeation Through Plastic Dangerous Goods Packaging During Transport in Freight Containers – Detection of Potentially Explosive Mixtures in Containers Under Normal Conditions of Carriage

The key point within the scope of this research project was to find out whether there was a risk of creating an explosive atmosphere by permeation of flammable liquid compounds during transport of dangerous goods in freight containers under normal conditions of carriage. Therefore, all aspects that had an influence on the formation of such an atmosphere had to be considered. The most important influencing factors were permeation, air change in the freight container and ambient temperature. The first step was to investigate the permeation with different packaging materials, charge and temperatures. Furthermore, the air change rates of different freight containers were measured. A few climate tests with containers on ships, e.g. to Singapore, were performed to assess normal conditions of carriage. Another important point was measuring the solvent (toluene) concentration in the gas phase in a freight container loaded with plastic intermediate bulk containers (IBCs) filled with toluene. To confirm that the measured values were in the right range, the toluene concentration in the gas phase in a container was calculated with different packaging materials, air change rates and temperatures. The results of the measurements and calculations have shown that safety layers in the packaging wall, e.g. the copolymer of ethylene and vinyl alcohol (EVOH) and polyamide, can reduce the rate of permeation by more than a decimal power, but the lower explosive limit of toluene is easily reached within a few hours at 40°C charge temperature if there is no barrier. Copyright © 2012 John Wiley & Sons, Ltd.     

Bioaccessibility of provitamin A carotenoids in bananas (Musa spp.) and derived dishes in African countries

Bananas and plantains (Musa spp.) constitute an important component of the diet in Africa. Substantial levels of provitamin A carotenoids (pVACs) in Musa fruit have been reported, but the bioaccessibility of these pVACs remains unknown. In this study, we used an in vitro digestion model to assess the bioaccessibility (i.e. the transfer into micelles) of pVACs from boiled bananas and derived dishes using the Eastern Democratic Republic of Congo as a study context. In particular, the effect of different food ingredients added to boiled bananas on pVAC’s bioaccessibility was studied. The bioaccessibility of all-trans β-carotene ranged from 10% to 32%, depending on the food recipes, and was modified, particularly when pVACs-rich ingredients (palm oil/amaranth) were added. Efficiency of micellarization of all-trans β-carotene was similar to that of all-trans α-carotene and depended on the cultivar (Musilongo, plantain type, 16%; Vulambya, East African cooking type, 28%), while that of the 13-cis isomer was higher (21–33.5%). Taking into account bioaccessibility, the estimated vitamin A activity was significantly different across the different Musa-based dishes tested. Results are discussed in terms of recommendations to help reduce vitamin A deficiency in Musa-dependent African communities.     

Glucons?ureverg?rung durch Milchs?urebakterien des Weines

Zusammenfassung Insgesamt 116 verschiedene, überwiegend aus Wein isolierte Stämme von Milchsäure-bakterien der GattungenLactobacillus, Leuconostoc, Pediococcus undStreptococcus wurden auf die Fähigkeit zur Verwertung von Gluconsäure untersucht. Bis auf einzelne Ausnahmen wurde Gluconsäure von denLactobacillus-Arten, die den UntergattungenStreptobacterium undBetabacterium angehörten, und der Mehrzahl derLeuconostoc-Stämme vergoren. VonPediococcus wurde Gluconsäure nicht abgebaut. Bei wachsenden Kulturen und ruhenden Zellen vonLactobacillus brevis, Lactobacillus casei undLeuconostoc oenos waren die Endprodukte des Gluconsäureabbaus Milchsäure, Essigsäure, Äthanol und CO₂. Milchsäure entsteht aus Gluconsäure in annähernd äquimolaren Mengen. In einem aus Wein und Hefeextrakt bestehenden Medium (pH 3,5) wurden 0,5 g Gluconsäure und 4,5 g Äpfelsäure je 1 vonLactobacillus brevis undLeuconostoc oenos vollständig abgebaut.

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Fermentation of gluconic acid by lactic acid bacteria isolated from wine

Summary The fermentation of gluconic acid was investigated in 116 different strains of lactic acid bacteria belonging to the generaLactobacillus, Leuconostoc, Pediococcus andStreptococcus. Most of the strains were isolated from wine. Gluconic acid was fermented by nearly all species of the genusLactobacillus (belonging to the subgeneraStreptobacterium andBetabacterium and by most strains ofLeuconostoc. The pediococci did not ferment gluconic acid. Growing cultures and resting cells ofLactobacillus brevis, Lactobacillus casei andLeuconostoc oenos formed lactic acid, acetic acid, ethanol and CO₂ from gluconic acid. Lactic acid was formed in about equimolar amounts from gluconic acid.Lactobacillus brevis andLeuconostoc oenos metabolised completely 0.5 g of gluconic acid and 4.5 g of malic acid per liter when cultured in a medium consisting of wine and a small amount of yeast extract (at pH 3.5).

     

Enhanced mechanical properties of epoxy composites using cellulose micro- and nano-crystals

Epoxy polymers are commonly utilized in structural applications due to their high bearing capacity and excellent chemical resistance. However, their inherent brittleness poses a significant challenge for their use in high shock and fracture strength products. To address this shortcoming, fillers can be incorporated into the polymer during preparation. In this study, we aimed to investigate the effect of incorporating cellulose-based fillers, namely cellulose nanocrystals (CNCs) and microcrystalline cellulose (MCC), on the mechanical properties of epoxy polymer composites. The study evaluated the impact of various factors, including filler concentration, particle size, and moisture content, on the mechanical properties of the composites. The results demonstrated that the incorporation of CNC or MCC powders at concentrations below 5% could enhance the mechanical properties of the resulting epoxy composites without adversely affecting their surface and thermal properties. The maximum tensile strength and fracture toughness of the filler-based epoxy composites were achieved at 2 and 4 wt% for CNCs and MCC, respectively. CNCs with a smaller particle size distribution were found to be much more effective than MCC in improving the mechanical properties of the epoxy composites. Furthermore, utilizing dried fillers resulted in a higher improvement in tensile strength, which was achieved at lower filler concentrations.     

Desalination of a brick by application of an electric DC field

Salts in masonry can cause various problems as decay of the masonry itself, lost adhesion of plaster and hygroscopic moisture. Chlorides are among the most common building salts and the present paper is focused on removal of chlorides from a brick in an applied electric field as a step towards developing an electrochemical desalination method for brick masonry. Experiments were conducted in laboratory scale with one type of bricks that were contaminated with either NaCl or KCl through submersion in salt solutions prior to application of current. It was seen that NaCl was slower supplied to the brick during submersion and slower removed in the applied electric field than KCl. This indicates that the removal rate of chloride depends on the associated cation and this must be taken into account when desiding the duration of full scale actions. The electrochemical desalination was very efficient and 99% removal of chloride was obtained. The final concentration in the brick after treatment was less than 10 mg Cl/kg and this concentration is unproblematic. When low salt concentrations were reached during the electrochemical treatment, electroosmotic dewatering of the brick started, showing that electroosmotic dewatering occurs at low ionic concentrations.