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51.
Fabrizio Stefani F. Benzoni S.-Y. Yang M. Pichon P. Galli C. A. Chen 《Coral reefs (Online)》2011,30(4):1033-1049
A combined morphological and genetic study of the coral genus Stylophora investigated species boundaries in the Gulf of Aden, Yemen. Two mitochondrial regions, including the hypervariable IGS9 spacer
and the control region, and a fragment of rDNA were used for phylogenetic analysis. Results were compared by multivariate
analysis on the basis of branch morphology and corallite morphometry. Two species were clearly discriminated by both approaches.
The first species was characterised by small corallites and a low morphological variability and was ascribed to a new geographical
record of Stylophora madagascarensis on the basis of its phylogenetic distinction and its morphological similarity to the type material. The second species was
characterised by larger corallite size and greater morphological variability and was ascribed to Stylophora pistillata. The analysis was extended to the intrageneric level for other S.
pistillata populations from the Red Sea and the Pacific Ocean. Strong internal divergence was evident in the genus Stylophora. S. pistillata populations were split into two highly divergent Red Sea/Gulf of Aden and western Pacific lineages with significant morphological
overlap, which suggests they represent two distinct cryptic species. The combined use of morphological and molecular approaches,
so far proved to be a powerful tool for the re-delineation of species boundaries in corals, provided novel evidence of cryptic
divergence in this group of marine metazoans. 相似文献
52.
Patrick MF Derkx Thomas Janzen Kim I Sørensen Jeffrey E Christensen Birgitte Stuer-Lauridsen Eric Johansen 《Microbial cell factories》2014,13(Z1):S5
The food industry is constantly striving to develop new products to fulfil the ever changing demands of consumers and the strict requirements of regulatory agencies. For foods based on microbial fermentation, this pushes the boundaries of microbial performance and requires the constant development of new starter cultures with novel properties. Since the use of ingredients in the food industry is tightly regulated and under close scrutiny by consumers, the use of recombinant DNA technology to improve microbial performance is currently not an option. As a result, the focus for improving strains for microbial fermentation is on classical strain improvement methods. Here we review the use of these techniques to improve the functionality of lactic acid bacteria starter cultures for application in industrial-scale food production. Methods will be described for improving the bacteriophage resistance of specific strains, improving their texture forming ability, increasing their tolerance to stress and modulating both the amount and identity of acids produced during fermentation. In addition, approaches to eliminating undesirable properties will be described. Techniques include random mutagenesis, directed evolution and dominant selection schemes. 相似文献
53.
A Yay D Akkuş H Yapıslar E Balcıoglu MF Sonmez S Ozdamar 《Biotechnic & histochemistry》2014,89(8):552-557
Nitric oxide (NO) plays a significant role in the development of diabetic nephropathy. We investigated the effects of an antioxidant, carnosine, on streptozotocin (STZ)-induced renal injury in diabetic rats. We used four groups of eight rats: group 1, control; group 2, carnosine treated; group 3, untreated diabetic; group 4, carnosine treated diabetic. Kidneys were removed and processed, and sections were stained with periodic acid-Schiff (PAS) and subjected to eNOS immunohistochemistry. Examination by light microscopy revealed degenerated glomeruli, thickened basement membrane and glycogen accumulation in the tubules of diabetic kidneys. Carnosine treatment prevented the renal morphological damage caused by diabetes. Moreover, administration of carnosine decreased somewhat the oxidative damage of diabetic nephropathy. Appropriate doses of carnosine might be a useful therapeutic option to reduce oxidative stress and associated renal injury in diabetes mellitus. 相似文献
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Activation kinetics of the sodium and potassium conductances were re-examined in fresh axons of Loligo forbesi exhibiting very little if any potassium accumulation and a very small leak conductance, special attention being paid to the initial lag phase which precedes the turning-on of the conductances. The axons were kept intact and voltage-clamped at 2–3°C.In all cases, the rising phase of the currents could be fitted with very good accuracy using the Hodgkin-Huxley (1952) equations although, in most cases, the turning-on of the conductance did not coincide with the beginning of the depolarizing test pulse. The delay which separates the change in potential and the turning-on of current (the activation delay) was analyzed quantitatively for different prepulse and pulse potentials. The measured activation delay differed significantly from the delay predicted by the original HH equations. This difference (the non-HH delay) varied with prepulse and pulse potentials. For the potassium current, the relationship between the non-HH delay and pulse potential for a constant prepulse was bell shaped, the maximum value (0.7 ms for a prepulse to –80 mV) being reached for about 0 mV For this same current, the relationship between the non-HH delay and the prepulse potential for a constant pulse potential was sigmoidal, starting from a minimum value of around 0.5 ms at –100 mV and rising to 5 ms at –15 mV Essentially similar results were obtained for the sodium current although the non-HH delay was three to five times smaller and the dependency upon prepulse potential not significant. These results are in agreement with previous observations on squid axons and frog nodes of Ranvier and suggest that the opening of an ionic channel is preceded by a short but essential voltage-dependent conformational change of the channel protein.
Offprint requests to: Y. Pichon 相似文献
56.
Laurent Pichon Annie Hampe Thierry Giffon Gwenaelle Carn Jean Yves Legall Veronique David 《Immunogenetics》1996,44(4):259-267
In an effort to initiate steps designed to characterize the idiopathic hemochromatosis disease gene, the HLA-A/HLA-F region where this gene is in disequilibrium linkage with some polymorphic markers has been overlapped by a yeast artificial
chromosome (YAC) contig. In order to achieve the physical mapping of these YACs and of the corresponding genomic region, we
subcloned one of the YACs involved. A computer-assisted analysis of the sequence of one subclone led to the isolation of a
potential exon that proved to belong to a new expressed messenger named HCGIX. After Southern blot analysis, the corresponding cDNA clone was found to belong to a new multigene family whose members are
dispersed throughout the HLA class I region and are closely associated with members of another recently described multigene family designated PERB11. The data reported here suggest that these two multigene families form a cluster that have been dispersed together throughout
the telomeric part of the major histocompatibility complex and have been involved in the genesis of this human class I region.
Received: 23 February 1996 / Revised: 23 April 1996 相似文献
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Marie-Josee MF Lemoy Angela Colagross Schouten Don R Canfield 《Comparative medicine》2016,66(1):59-62
Bioabsorbable hemostatic agents such as oxidized regenerated cellulose are widely used to control intraoperative diffuse capillary bleeding. Compared with electrocautery or ligation, oxidized regenerated cellulose has the advantage of controlling bleeding without occluding the vessel lumen or causing thermal injuries to adjacent tissue. Although the manufacturer recommends removal of the material once hemostasis is achieved, oxidized regenerated cellulose is a bioabsorbable hemostatic agent and is often left in the surgical bed to prevent subsequent bleeding after surgical closure. However, noninvasive imaging techniques have revealed granulomatous foreign-body reactions that mimic infection or tumor recurrence. We present a case report of sterile peritonitis and granuloma formation secondary to the presence of oxidized regenerated cellulose after intestinal resection to excise a colonic adenocarcinoma in an aged rhesus macaque.Bioabsorbable hemostatic agents such as oxidized regenerated cellulose (for example, Surgicel) are widely used to control intraoperative diffuse capillary bleeding. Compared with electrocautery or ligation, oxidized regenerated cellulose has the advantage of controlling bleeding without occluding the vessel lumen or causing thermal injuries to adjacent tissue.16Oxidized regenerated cellulose is formed by dissolving the α-cellulose of decomposed wood pulp in an alkaline solution and subsequently regenerating it as a continuous fiber. This fiber is then woven into a gauze and oxidized.17,22 Oxidized regenerated cellulose is supplied as a substrate that is flexible, malleable, and trimable.16The mechanism of hemostasis of oxidized regenerated cellulose is reportedly associated with its caustic activity.2 The oxidation of cellulose produces a low-pH organic acid that reacts with blood, thus forming an artificial clot and causing platelet aggregation.18Although the manufacturer recommends the removal of oxidized regenerated cellulose once hemostasis is achieved,8 the product, a bioabsorbable hemostatic agent, is often left in situ within the surgical bed to prevent bleeding after surgical procedures. The biodegradation and elimination of oxidized regenerated cellulose from the tissue occurs in 2 phases.14 Polyanhydroglucuronic acid, the major functional unit of oxidized regenerated cellulose, is readily soluble. This acid is degraded extracellulary and systematically cleared from the system approximately 18 h after implantation.13,14 The remaining fibrous residue, however, requires macrophage phagocytosis for clearance and can be observed within macrophages for at least 48 h after implantation.13 Unfortunately, these fibrous residues have a prolonged degradation, and their persistence for as long as 7 mo after surgery has been confirmed histologically.7Despite the biocompatibility of oxidized regenerated cellulose, granulomatous foreign-body reactions that imitate infection or tumor recurrence have been revealed by using noninvasive imaging techniques.1,11,12,15,17,18,22 Here we describe a case of peritonitis and granuloma formation secondary to the presence of oxidized regenerated cellulose after an intestinal resection to excise a colonic adenocarcinoma in an aged rhesus macaque. 相似文献
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