Gas chromatographic analysis of histamine in mahi-mahi (Coryphaena hippurus)

Several authors have studied histamine using gas chromatography (GC) as a tool for quantitation, but the methods used were not always suitable depending on the kind of food. Problems frequently cited include incomplete histamine elution from the columns and peak tailing. Histamine is of interest because it is the factor common to all cases of scombroid poisoning, it has physiological and biological activity, and it is a chemical indicator of fish quality. In this study a modified GC method was used to quantify histamine in mahi-mahi (Coryphaena hippurus). Mean recovery was 67% for the GC method, compared with 90% for the AOAC fluorometric method. There was a 0.96 correlation of the GC histamine values with those of the AOAC fluorometric method. A temperature program, splitless/split injection, and analyte cleanup were essential for GC properties. Histamine retention time was 8.2 min. The method allowed peak height to be used for quantitation and simultaneous analysis of cadaverine and putrescine.     

The product space conditions the development of nations

Economies grow by upgrading the products they produce and export. The technology, capital, institutions, and skills needed to make newer products are more easily adapted from some products than from others. Here, we study this network of relatedness between products, or "product space," finding that more-sophisticated products are located in a densely connected core whereas less-sophisticated products occupy a less-connected periphery. Empirically, countries move through the product space by developing goods close to those they currently produce. Most countries can reach the core only by traversing empirically infrequent distances, which may help explain why poor countries have trouble developing more competitive exports and fail to converge to the income levels of rich countries.     

Impact of silviculture on dead wood and on the distribution and frequency of tree microhabitats in montane beech-fir forests of the Pyrenees

In forest ecosystems, the level of biodiversity is strongly linked to dead wood and tree microhabitats. To evaluate the influence of current forest management on the availability of dead wood and on the abundance and distribution of microhabitats, we studied the volume and diversity of dead wood objects and the distribution and frequency of cavities, dendrothelms, cracks, bark losses and sporophores of saproxylic fungi in montane beech-fir stands. We compared stands unmanaged for 50 or 100 years with continuously managed stands. A total of 1,204 live trees and 460 dead wood objects were observed. Total dead wood volume, snag volume and microhabitat diversity were lower in the managed stands, but the total number of microhabitats per ha was not significantly different between managed and unmanaged stands. Cavities were always the most frequent microhabitat and cracks the least frequent. Dendrothelm and bark loss were favored by management. Beech (Fagus sylvatica) carried many more microhabitats than silver fir (Abies alba), especially cavities, dendrothelms and bark losses. Fir very scarcely formed dendrothelms. Secondary tree species played an important role by providing cracks and bark losses. The proportion of microhabitat-bearing trees increased dramatically above circumference thresholds of 225 cm for beech and 215 cm for fir. Firs with a circumference of less than 135 cm did not carry microhabitats. In order to conserve microhabitat-providing trees and to increase the volume of dead wood in managed stands, we recommend conserving trees that finish their natural cycle over 10–20% of the surface area.     

Impact of genetic and environmental factors on einkorn wheat (Triticum monococcum L. subsp. monococcum) polysaccharides

To evaluate the effect of genotype, year and location on 1000 kernel weight, falling number, alpha- and beta-amylase activity, pasting properties, β-glucan, fructan, total starch, amylose, resistant starch and dietary fibre contents of wholemeal flour, four einkorns and one control bread wheat were cropped in Italy for two years in four different locations.     

Assessment of genetic diversity of Highland bananas from the National Banana Germplasm Collection at Rubona,Rwanda using RAPD markers

The genetic similarities of 49 accessions of bananas from The National Banana Collection at Rubona were investigated using random amplified polymorphic DNA markers. A total of 120 primers were screened for their usefulness in amplifying DNA fragments of four cultivars belonging to the subgroup Mutika–Lujugira. Fifteen random primers were selected for more detailed analysis, on the basis of providing reproducible amplification and revealing a high level of variation between the four cultivars. The genetic similarity was estimated using a simple matching coefficient which showed the lowest value of 0.46 between ‘Ingumba’ and ‘Ishika’ and the highest value of 0.85 between ‘Kirayenda’ and ‘Inyabukuwe’. The data of matrix of coefficient of similarity was subjected to cluster analysis using the unweighted pair group method with arithmetic average (UPGMA). Each accession was clearly separated. The results of this study are important for the curation of the banana germplasm collection in Eastern Central Africa and for future breeding of this crop.     

Rectovaginal fistula following colectomy with an end-to-end anastomosis stapler for a colorectal adenocarcinoma

An 11-year-old, female neutered Labrador retriever was presented with a micro-invasive differentiated papillar adenocarcinoma at the colorectal junction. A colorectal end-to-end anastomosis stapler device was used to perform resection and anastomosis using a transanal technique. A rectovaginal fistula was diagnosed two days later. An exploratory laparotomy was conducted and the fistula was identified and closed. Early dehiscence of the colon was also suspected and another colorectal anastomosis was performed using a manual technique. Comparison to a conventional manual technique of intestinal surgery showed that the use of an automatic staple device was quicker and easier. To the authors' knowledge, this is the first report of a rectovaginal fistula occurring after end-to-end anastomosis stapler colorectal resection-anastomosis in the dog. To minimise the risk of this potential complication associated with the limited surgical visibility, adequate tissue retraction and inspection of the anastomosis site are essential.     

Evaluation of heat damage, sugars, amylases and colour in breads from einkorn, durum and bread wheat flours

To limit nutritional losses and optimise bread processing, heat damage indices (furosine, glucosylisomaltol, hydroxymethylfurfural), sugars, α-amylase, β-amylase and colour were monitored during bread manufacturing from refined flour of three einkorn, three bread and one durum wheat samples. The heat damage indices increased only during the baking step. Furosine was significantly lower in einkorn (on average, 9.3 ± 5.33 and 25.3 ± 10.70 mg/100 g protein in crumb and crust, respectively) than in bread wheat (31.6 ± 3.05 and 115.6 ± 13.53) and durum wheat (36.2 ± 2.82 and 165.0 ± 3.17). Glucosylisomaltol and hydroxymethylfurfural were detected only in the crust, with lower levels in einkorn (on average, 2.3 ± 1.78 and 10.0 ± 7.79 mg/kg DM, respectively) than in bread wheat (13.1 ± 5.57 and 42.8 ± 10.64) and durum wheat (18.9 ± 1.11 and 57.2 ± 0.80). The different behaviour of einkorn was probably related to its moderate β-amylase activity, and thus the low maltose content of its dough. Colour was correlated with heat damage, as einkorn breads were lighter than the others.The results show that einkorn bread undergoes lower heat damage than analogous products from durum and bread wheat, thus probably better preserving its nutritional value.     

Antiprotozoal activities of organic extracts from French marine seaweeds

Marine macrophytes contain a variety of biologically active compounds, some reported to have antiprotozoal activity in vitro. As a part of a screening program to search for new natural antiprotozoals, we screened hydroalcoholic and ethyl acetate extracts of 20 species of seaweeds from three phyla (Rhodophyta, Heterokontophyta and Chlorophyta), sampled along the Normandy (France) coast. We tested them in vitro against the protozoa responsible for three major endemic parasitic diseases: Plasmodium falciparum, Leishmania donovani and Trypanosoma cruzi. The selectivity of the extracts was also evaluated by testing on a mammalian cell line (L6 cells). Ethyl acetate extracts were more active than hydroalcoholic ones. Activity against T. cruzi and L. donovani was non-existent to average, but almost half the extracts showed good activity against P. falciparum. The ethyl acetate extract of Mastocarpus stellatus showed the best antiplasmodial activity as well as the best selectivity index (IC(50) = 2.8 μg/mL; SI > 30). Interestingly, a red algae species, which shares phylogenetic origins with P. falciparum, showed the best antiplasmodial activity. This study is the first to report comparative antiprotozoal activity of French marine algae. Some of the species studied here have not previously been biologically evaluated.