NO-steroids: potent anti-inflammatory drugs with bronchodilating activity in vitro.

The synthesis of nitric oxide (NO) releasing anti-inflammatory molecules is an innovative strategy to design novel anti-inflammatory drugs. These compounds slowly release NO, via an enzymatic pathway conferring new biological activities. Here we report the potent anti-inflammatory profile and the bronchodilator effect of nitro-derivatives of steroids, prednisolone, especially. The experiments were performed on guinea pig trachea or perfused bronchioles precontracted by methacholine. We demonstrated for the first time that unlike the parent compounds which produced weak bronchodilation at the maximum used dose (10(-4) M), NO-steroids caused a significant bronchodilating activity up to 70% of the maximal relaxation induced by 10(-4) M papaverine. This effect was epithelium- and endogenous-independent but cGMP-dependent. Taken together these data suggest that NO-steroids possessed a more potent anti-inflammatory activity than native compounds coupled with a concentration-dependent bronchodilating activity. Further studies are required to determine if NO-steroids will be effective as anti-inflammatory agents in the clinic.     

Involvement of cyclooxygenase 2 in the protective effect of 17beta-estradiol on hypercholesterolemic rabbit aorta

The involvement of cyclooxygenase (COX) in the effects of 17beta-estradiol was investigated on hypercholesterolemic rabbits aorta. Acetylsalycilic acid, nimesulide, or SQ22536 was used as respective antagonist of COX-1, COX-2, or adenylate cyclase using aortic rings precontracted with phenylephrine and exposed to cumulative concentrations of acetylcholine (ACh). The relaxation effect of ACh was impaired by hypercholesterolemia and restored by an 8-week 17beta-estradiol treatment. In the control group treated with estrogen, nimesulide, acetylsalycilic acid, or SQ22536 slightly reduced the response to ACh. In hypercholesterolemic rabbits treated with estrogen, nimesulide significantly reduced the maximal relaxation and shifted to the right the relaxation curve of ACh, whereas acetylsalycilic acid did not modify the maximal response to ACh but displaced slightly the concentration-response curve. SQ22536 reduced the relaxant effect of ACh down to the level obtained in the presence of nimesulide. These results suggest that the protective effect of 17beta-estradiol against hypercholesterolemia involved COX-2/adenylate cyclase pathway.     

Antiproliferative effects of nitrosulindac on human colon adenocarcinoma cell lines

Nonsteroidal anti-inflammatory drugs (NSAIDs) reduce the incidence of colon cancer, but their use is limited by toxicity in the gastrointestinal tract. The coupling of a nitric oxide-releasing moiety to NSAIDs strongly reduces these side effects. We demonstrated that the NO-releasing sulindac (nitrosulindac) has much more potent effects on colon adenocarcinoma cell lines compared to sulindac. Moreover, it could inhibit the growth of cells in soft agar experiments, demonstrating the antineoplastic activity at low concentration of nitrosulindac. However, this reduction in the growth of colon cancer cells seemed to be independent of the classical apoptosis pathway and could be explained by a cytostatic effect. Nitrosulindac caused a light perturbation of the cell cycle parameters not linked to a modification of the levels of p21 or the proliferating cell nuclear antigen. Moreover, neither sulindac, nor nitrosulindac, were able to inhibit the NF-kappa B pathway. These data suggested that nitrosulindac could be a better solution compared to other NSAIDs in the treatment of colon cancer.     

The design and synthesis of the high efficacy, non-peptide CCK1 receptor agonist PD170292

The design, synthesis and biological actions of a novel, non-peptide CCK1 receptor agonist (PD 170292) which exhibits a similar pharmacological profile to the CCK analogue JMV180 is reported. PD 170292 was designed based on a consideration of the structures of a peptide based CCK1 receptor selective agonist and a peptoid CCK2 receptor selective antagonist.     

Effect of phytase supplementation on phosphorus digestibility in low-phytate barley fed to finishing pigs

Forty crossbred barrows (Camborough 15 Line female×Canabred sire) weighing an average of 79.6±8.0?kg were used in a factorial design experiment (5 barleys×2 enzyme levels) conducted to determine the effects of phytase supplementation on nutrient digestibility in low-phytate barleys fed to finishing pigs. The pigs were assigned to one of 10 dietary treatments comprised of a normal 2-rowed, hulled variety of barley (CDC Fleet, 0.26% phytate) or 2 low-phytate hulled genotypes designated as LP422 (0.14% phytate) and LP635 (0.09% phytate). A normal, hulless barley (CDC Dawn, 0.26% phytate) and a hulless genotype designated as LP422H (0.14% phytate) were also included. All barleys were fed with and without phytase (Natuphos 5000 FTU/kg). The diets fed contained 98% barley, 0.5% vitamin premix, 0.5% trace mineral premix, 0.5% NaCl and 0.5% chromic oxide but no supplemental phosphorus. The marked feed was provided for a 7-day acclimatization period, followed by a 3-day faecal collection. In the absence of phytase, phosphorus digestibility increased substantially (P<0.05) as the level of phytate in the barley declined. For the hulled varieties, phosphorus digestibility increased from 12.9% for the normal barley (0.26% phytate) to 35.3 and 39.8% for the two low-phytate genotypes (0.14 and 0.09% phytate respectively). For the hulless varieties, phosphorus digestibility increased from 9.2% for the normal barley (0.26% phytate) to 34.7% for the hulless variety with 54% of the normal level of phytate (0.14% phytate). In contrast, when phytase was added to the diet, there was little difference in phosphorus digestibility between pigs fed normal barley and those fed the low-phytate genotypes (significant barley×enzyme interaction, P=0.01). For the hulled varieties, phosphorus digestibility was 50.1% for the barley with the normal level of phytate (0.26% phytate) compared with 51.1 and 52.4% for the varieties with 54 and 35% of the normal level of phytate (0.14 and 0.09% phytate respectively). For the hulless varieties, phosphorus digestibility increased from 47.1% for the normal barley (0.26% phytate) to 54.4% for the hulless variety with 54% of the normal level of phytate (0.14% phytate). In conclusion, both supplementation with phytase and selection for low-phytate genotypes of barley were successful in increasing the digestibility of phosphorus for pigs. Unfortunately, the effects did not appear to be additive. Whether or not swine producers will choose low-phytate barley or supplementation with phytase as a means to improve phosphorus utilization, will likely depend on the yield potential of low-phytate barley and the additional costs associated with supplementation with phytase.     

Dendritic cells are host cells for mycobacteria in vivo that trigger innate and acquired immunity.

In the present study, we investigated in vivo the infection and APC functions of dendritic cells (DC) and macrophages (Mphi) after administration of live mycobacteria to mice. Experiments were conducted with Mycobacterium bovis bacillus Calmette-Guerin (BCG) or a rBCG expressing a reporter Ag. Following infection of mice, DC and Mphi were purified and the presence of immunogenic peptide/MHC class II complexes was detected ex vivo on sorted cells, as was the secretion of IL-12 p40. We show in this study that DC is a host cell for mycobacteria, and we provide an in vivo detailed picture of the role of Mphi and DC in the mobilization of immunity during the early stages of a bacterial infection. Strikingly, BCG bacilli survive but remain stable in number in the DC leukocyte subset during the first 2 wk of infection. As Ag presentation by DC is rapidly lost, this suggests that DC may represent a hidden reservoir for mycobacteria.     

Widespread distribution of deletions of the bgl operon in natural isolates of Escherichia coli

A deletion that includes the bgl (beta-glucoside utilization) operon of Escherichia coli was originally detected in several rarely occurring natural isolates that utilize cellobiose. Here I show that bgl deletions are present in 95% of the Cel+ isolates obtained from diverse sources. They are also present in 29% of the Cel- strains in two different collections of natural isolates of E. coli. At least three versions of bgl deletions are present in E. coli populations. In the most common version approximately 8 kb of DNA around the bgl region of E. coli K12 is replaced by a specific 6.5-kb DNA fragment. In another version a deletion of similar length is not replaced by the same sequence. A third version involves deletion of approximately 14 kb without the replacement fragment being present. The distribution of these deletions suggests that the version 1 deletion occurred very early in the history of E coli. It also appears likely that there is selection for bgl deletions in Cel+ strains of E. coli. The presence of the version 1 deletion within distantly related phylogenetic groups of E. coli provides evidence for recombination within natural populations of E coli.      

Heterologous Expression and Biochemical Characterization of a New Chloroperoxidase Isolated from the Deep-Sea Hydrothermal Vent Black Yeast Hortaea werneckii UBOCC-A-208029

Marine Biotechnology - The initiation of this study relies on a targeted genome-mining approach to highlight the presence of a putative vanadium-dependent haloperoxidase-encoding gene in the...