Effect of defrosting on quantity of volatile amines in stored sardines and herring used for tuna fattening

Studied were the quantities of volatile amines, total volatile bases nitrogen (TVB‐N) and trimethylamine nitrogen (TMA‐N) in stored sardines (Sardina pilchardus) and herring (Clupea harengus) over a 24‐h period after defrosting. At the beginning of the experiment analyses showed TVB‐N quantities in the flesh of both species to be higher than the FAO‐recommended limit. TMA‐N concentrations exceeded the acceptance limit 6 h after defrosting in herring samples and after 12 h in sardines. During the entire experiment TMA‐N and TVB‐N concentrations in sardines were above the tolerance limit. The defrosting method usually applied in tuna farms is unsuitable for maintenance of a high quality food supply. Low quality baitfish can cause reduced weight gain as well as induce health problems and mortality in farmed tuna (Thunnus thynnus) populations.     

Evidence for a single glutamate receptor of the ionotropic kainate/quisqualate type

The kainate (KA) and the quisqualate (QUIS) receptors that activate cation channels in the central nervous system have previously been defined as two of the major glutamate receptor types. In amphibian brain, an exceptionally rich source of these sites, they can be coextracted by octylglucoside and shown to behave as one entity in all analyses made in solution. When partly purified by lectin affinity, ion-exchange chromatography or by sucrose gradient centrifugation, the two activities comigrate in a 1:1 ratio. When the QUIS component is bound to an immobilized specific QUIS agonist, the KA component is extracted in parallel with it. There are equivalent numbers of the QUIS and KA sites and the two sites show a single affinity series for the binding of glutamatergic agonists. We deduce that KA or QUIS select different conformations of a single KA/QUIS receptor binding site, leading thus to the different channel-opening events that have been reported for these two agonists.     

Exploring the dark genome: implications for precision medicine

Mammalian Genome - The increase in the number of both patients and healthcare practitioners who grew up using the Internet and computers (so-called “digital natives”) is likely to...     

Diversity and distribution of reptiles in Romania

The reptile fauna of Romania comprises 23 species, out of which 12 species reach here the limit of their geographic range. We compiled and updated a national database of the reptile species occurrences from a variety of sources including our own field surveys, personal communication from specialists, museum collections and the scientific literature. The occurrence records were georeferenced and stored in a geodatabase for additional analysis of their spatial patterns. The spatial analysis revealed a biased sampling effort concentrated in various protected areas, and deficient in the vast agricultural areas of the southern part of Romania. The patterns of species richness showed a higher number of species in the warmer and drier regions, and a relatively low number of species in the rest of the country. Our database provides a starting point for further analyses, and represents a reliable tool for drafting conservation plans.     

The poly-beta-hydroxybutyrate granule in vivo. A new insight based on NMR spectroscopy of whole cells

High resolution 13C NMR spectroscopy of live cells has been used to show that poly-beta-hydroxybutyrate (PHB) is predominantly in a mobile state within the storage granules of Alcaligenes eutrophus, Methylobacterium extorquens, and Methylobacterium AM1. Comparison of chemical and NMR analysis of PHB indicates that about 70% of the polymer in A. eutrophus gives sharp observable resonances. Temperature-dependent line widths and relaxation rates together with nuclear Overhauser effect measurements demonstrate that the observed material is effectively a mobile amorphous elastomer that is well above its glass transition temperature. The hydroxyvalerate-hydroxybutyrate copolymer produced by propionate-fed A. eutrophus has virtually the same mobility as the homopolymer. Evidence is presented indicating that water is an integral component of the PHB granule and that this component acts as a plasticizer for the polymer. These observations strongly suggest that the enzyme(s) responsible for PHB biosynthesis and consumption operate only on mobile hydrated material and that the solid granules characteristic of dried cells are partially artifactual. This model is supported by a reinterpretation of previously inexplicable biochemical results.     

Two new species of coccidia (Apicomplexa: Eimeriidae) from Madagascar Gekkonids

Two new species of coccidia (Apicomplexa: Eimeriidae) are described from the Madagascar giant day gecko, Phelsuma madagascariensis grandis, and the Golddust day gecko, P. laticauda. Both species of coccidia were found to infect the anterior one-half of the small intestine. Oocysts of Eimeria brygooi n. sp. are spherical or subspherical, 23.0 X 21.3 (18.8-25.2 X 16.4-23.2)micron; shape index (L/W) 1.1 (1.0-1.2). A micropyle, oocyst residuum, and polar granule are absent. Sporocysts are ovoid, 9.2 X 7.9 (8.0-10.0 X 7.2-8.8) micron; shape index 1.2 (1.0-1.3), with a Goussia-type suture; Stieda and substieda bodies are absent. A sporocyst residuum is present, 4.2 X 3.0 (3.2-6.4 X 2.4-4.0) micron. Sporozoites are elongate, with anterior and posterior refractile bodies. This coccidian was found to infect five of six (83%) P. m. grandis and one of five (20%) P. laticauda examined. Oocysts of Isospora gekkonis n. sp. are spherical or subspherical, 24.2 X 22.0 (21.6-26.4 X 20.0-23.6) micron; shape index 1.1 (1.0-1.2). A micropyle and oocyst residuum are absent; polar granule present. Sporocysts are ovoid, 12.2 X 9.4 (11.2-12.8 X 8.4-10.0) micron, with Stieda and substieda bodies; shape index 1.3 (1.2-1.4). A sporocyst residuum is present, either compact, 5.1 X 4.2 (4.0-7.2 X 3.2-5.6) micron or diffuse. Sporozoites are elongate, with anterior and posterior refractile bodies. Isospora gekkonis was found in two of six (33%) P. m. grandis and one of five (20%) P. laticauda. In addition, oocysts of Cryptosporidium sp. were found in the cloacas of two of six (33%) necropsied P. m. grandis.     

Chemistry of the collagen cross-links. Origin and partial characterization of a putative mature cross-link of collagen.

The conversion of the reducible divalent cross-links in collagen to non-reducible multivalent cross-links in mature collagen has resulted in the identification of several new amino acids as the putative mature cross-link. None of these compounds has completely satisfied the necessary criteria. We have now isolated an amino acid of high Mr, derived from lysine, that is only present in high-Mr peptides derived from mature collagen. Its increase with age of the tissue correlates with the decrease in the reducible cross-links, and it is present both in mature skin and bone, which are initially cross-linked through the aldimine and oxo-imine divalent cross-link respectively. We propose that this amino acid, as yet incompletely characterized and designated compound M, is a major cross-link of mature collagen.