70 research outputs found
Bilirubin decreases NOS2 expression via inhibition of NAD(P)H oxidase: implications for protection against endotoxic shock in rats.
We investigated a possible beneficial role for bilirubin, one of the products of heme degradation by the cytoprotective enzyme heme oxygenase-1 in counteracting Escherichia coli endotoxin-mediated toxicity. Homozygous jaundice Gunn rats, which display high plasma bilirubin levels due to deficiency of glucuronyl transferase activity, and Sprague-Dawley rats subjected to sustained exogenous bilirubin administration were more resistant to endotoxin (LPS)-induced hypotension and death compared with nonhyperbilirubinemic rats. LPS-stimulated production of nitric oxide (NO) was significantly decreased in hyperbilirubinemic rats compared with normal animals; this effect was associated with reduction of inducible NO synthase (NOS2) expression in renal, myocardial, and aortic tissues. Furthermore, NOS2 protein expression and activity were reduced in murine macrophages stimulated with LPS and preincubated with bilirubin at concentrations similar to that found in the serum of hyperbilirubinemic animals. This effect was secondary to inhibition of NAD(P)H oxidase since 1) inhibition of NAD(P)H oxidase attenuated NOS2 induction by LPS, 2) bilirubin decreased NAD(P)H oxidase activity in vivo and in vitro, and 3) down-regulation of NOS2 by bilirubin was reversed by addition of NAD(P)H. These findings indicate that bilirubin can act as an effective agent to reduce mortality and counteract hypotension elicited by endotoxin through mechanisms involving a decreased NOS2 induction secondary to inhibition of NAD(P)H oxidase
New and confirmed records of fishes from the Cabo Verde archipelago based on photographic and genetic data
In recent decades the Cabo Verde ichthyofauna has been studied more extensively, and nowadays photo-recording is employed as a valuable asset under special caution and consideration. Four species reported here are new records for Cabo Verde: Carlarius sp., sea catfish; Serranus cabrilla, comber; Branchiostegus semifasciatus, African tilefish and Lutjanus dentatus, African coastal snapper. The presence in Cabo Verde of Glaucostegus cemiculus, blackchin guitarfish; Elops senegalensis, Senegalese ladyfish; Lophius spp., bathydemersal monkfishes; Rachycentron canadum, cobia; Pagrus auriga, African seabream; Lutjanus dentatus, African coastal snapper and Mugil cephalus, grey mullet, was re-confirmed by photo-records. Squalus megalops, cosmopolitan spurdog, was identified by genetic fingerprinting. The, two littoral species, P. auriga and M. cephalus, are firmly established in the archipelago and additional information on their occurrence is given. The findings reported in the present contribution may well be the result of a wider sharing of information between fishermen and other seafarers and scientists, rather than an indicator of recent faunal changes
European Red List of Marine Fishes
The European Red List is a review of the conservation
status of European species according to IUCN regional
Red Listing guidelines. It identifies those species that are
threatened with extinction at the regional level, so that
appropriate conservation action can be taken to improve
their status. This Red List publication summarises results
for all described native European marine fishes.Postprin
A computer-aided framework for subsurface identification of white shark pigment patterns
Subsurface video footage can be used as a successful identification tool for various marine organisms; however, processing of such information has proven challenging. This study tests the use of automated software to assist with photo-identification of the great white shark Carcharodon carcharias in the region of Gansbaai, on the south coast of South Africa. A subsurface photo catalogue was created from underwater video footage. Single individuals were identified by using pigmentation patterns. From this catalogue, two images of the head for each individual were inserted into automated contour-recognition software (Interactive Individual Identification System Beta Contour 3.0). One image was used to search the database, the other served as a reference image. Identification was made by means of a contour, assigned using the software to the irregular border of grey and white on the shark’s head. In total, 90 different contours were processed. The output provided ranks, where the first match would be a direct identification of the individual. The method proved to be accurate, in particular for high-quality images where 88.24% and 94.12%, respectively, were identified by two independent analysts as first match, and with all individuals identified within the top 10 matches. The inclusion of metadata improved accuracy and precision, allowing identification of even low-quality images.Keywords: Carcharodon carcharias, computer-aided identification, contour recognition, mark-recapture, photo-identification, underwate
Action du principe antitoxique polytissulaire (patp) sur la souris akr genetiquement leucemique traitee par le para- -di-(2-chloroethyl)-1-phenylalanine (pdcpa).
Phase transitions in Co nanoclusters grown by pulsed laser deposition
The crystalline structure of Co clusters embedded in an amorphous Al2O3 matrix was studied
by transmission electron microscopy (TEM) and electron diffraction (TED). In the first stage
of the growth a metastable structure (body-centred-cubic) is observed. A face-centred-cubic
phase (fcc) is found when the size of the clusters increases ( nm). The hexagonal-close-packed phase arises in the fcc phase by a succession of stacking faults at the largest sizes. The mechanisms of phase transformation have been determined by using high
resolution electron microscopy (HREM). The chemical nature of the clusters, in particular the
existence of Co-O bonds, was investigated by using electron energy loss spectroscopy
(EELS)
Acute food deprivation reduces expression of diazepam-binding inhibitor, the precursor of the anorexigenic octadecaneuropeptide ODN, in mouse glial cells
International audienceIn the central nervous system of mammals, the gene encoding diazepam-binding inhibitor (DBI) is exclusively expressed in glial cells. Previous studies have shown that central administration of a DBI processing product, the octadecaneuropeptide ODN, causes a marked inhibition of food consumption in rodents. Paradoxically, however, the effect of food restriction on DBI gene expression has never been investigated. Here, we show that in mice, acute fasting dramatically reduces DBI mRNA levels in the hypothalamus and the ependyma bordering the third and lateral ventricles. I.p. injection of insulin, but not of leptin, selectively stimulated DBI expression in the lateral ventricle area. These data support the notion that glial cells, through the production of endozepines, may relay peripheral signals to neurons involved in the central regulation of energy homeostasis
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