Detoxification of ochratoxin A,a food contaminant: Prevention of growth of Aspergillus ochraceus and its production of ochratoxin A

The toxicity of ochratoxin A (OTA), a mycotoxin produced by fungi ofAspergillus orPenicillium genera is now well documented. Its nephrotoxicity, immunosuppression, teratogenicity, and carcinogenicity have been widely studied. Physical and biochemical methods have been studied to prevent these toxinogenicAspergillus andPenicillium from producing OTA, and/or to destroy the mycotoxin when already produced in a liquid or a solid medium. Repeated freezing at ? 20?C and thawing at + 26?C aleatory reduce OTA production in a liquid medium. Exposure to UV B for different periods of time is efficient in preventing OTA production in a liquid medium. Gamma-irradiation from 2 to 5 kGy gives good results in preventing the production of OTA or destroying it when already produced. Carboxypeptidase is very efficient at 5 units/50 ml in a liquid medium for cleaving the OTA already produced.     

Dependence creating properties of lipotropin C-fragment (beta-endorphin): evidence for its internal control of behavior

The C-fragment of lipotropin (β-endorphin) possesses reinforcing properties, in that this peptide, like heroin, induced intraventricular self-administering behavior in drug naive rats. Only mild behavioral signs reminiscent of physical dependence were present. After injection into the nucleus raphé magnus, C-Fragment appeared to act as a discriminative stimulus in rats trained to discriminate fentanyl from saline. These data indicate that naturally occuring C-Fragment exerts powerful control of behavior, which may be of significance for the understanding of the mechanisms underlying opiate dependence.     

Cryopreservation of ectomycorrhizal fungi has minor effects on root colonization of Pinus sylvestris plantlets and their subsequent nutrient uptake capacity

The use of ectomycorrhizal (ECM) fungi for afforestation, bioremediation, and timber production requires their maintenance over long periods under conditions that preserve their genetic, phenotypic, and physiological stability. Cryopreservation is nowadays considered as the most suitable method to maintain the phenotypic and genetic stability of a large number of filamentous fungi including the ECM fungi. Here, we compared the ability of eight ECM fungal isolates to colonize Pinus sylvestris roots and to transport inorganic phosphate (Pi) and NH₄ ⁺ from the substrate to the plant after cryopreservation for 6 months at ?130 °C or after storage at 4 °C. Overall, the mode of preservation had no significant effect on the colonization rates of P. sylvestris, the concentrations of ergosterol in the roots and substrate, and the uptake of Pi and NH₄ ⁺. Comparing the isolates, differences were sometimes observed with one or the other method of preservation. Suillus bovinus exhibited a reduced ability to form mycorrhizas and to take up Pi following cryopreservation, while one Suillus luteus isolate exhibited a decreased ability to take up NH₄ ⁺. Conversely, Hebeloma crustuliniforme, Laccaria bicolor, Paxillus involutus, and Pisolithus tinctorius exhibited a reduced ability to form mycorrhizas after storage at 4 °C, although this did not result in a reduced uptake of Pi and NH₄ ⁺. Cryopreservation appeared as a reliable method to maintain important phenotypic characteristics (i.e., root colonization and nutrient acquisition) of most of the ECM fungal isolates studied. For 50 % of the ECM fungal isolates, the colonization rate was even higher with the cultures cryopreserved at ?130 °C as compared to those stored at 4 °C.     

The role of fish-poultry integration on fish growth performance,yields and economic benefits among smallholder farmers in sub-Saharan Africa,Tanzania

Aquaculture practices from sub-Saharan Africa are characterised by low production, owing to improper technology. Production can be increased through integrating fish farming with other existing on-farm activities, particularly livestock husbandry. We assessed the role of fish-poultry integration on all male Nile tilapia, Oreochromis niloticus growth performance, yields and economic benefits among smallholder farmers in sub-Saharan Africa, Tanzania. The study also compared phytoplankton species composition, abundance and biomass between the fish-poultry integration and non-integrated system. After 180 days of the experiment, all male O. niloticus cultured under fish-poultry integration exhibited significantly higher growth rates than those in the non-integrated system (p < 0.05). Gross fish yield (GFY), net fish yield (NFY) and net annual yields (NAY) obtained from fish-poultry integration were significantly higher than those from non-integrated system (p < 0.05). Partial enterprise budget analysis revealed that fish-poultry integration was more profitable than the non-integrated system. Moreover, fish-poultry integrated system produced significantly higher phytoplankton abundance and biomass than those from the non-integrated system. Results demonstrate that rural smallholder farmers can achieve higher growth rate, farm net yields and income by integrating all male O. niloticus with other on-farm activities than practising a stand-alone fish culture system.     

Use of a conflict procedure in pigeons to characterize anxiolytic drug activity: evaluation of N-methyl-D-aspartate antagonists.

Because of its apparent effectiveness in detecting non-benzodiazepine anxiolytic agents, a recently introduced conflict procedure in pigeons was used to evaluate possible anti-punishment activity of various N-methyl-d-aspartate (NMDA) antagonists. Punished responding was significantly increased by competitive NMDA antagonists (CPP, CGS 19755), but not by noncompetitive NMDA antagonists acting at either the ion channel (PCP, ketamine, MK-801), the glycine site (kynurenic acid, 7-chlorokynurenic acid, ACPC), or the polyamine site (ifenprodil) of the NMDA receptor complex; the proposed glutamate antagonist, riluzole, was also ineffective.     

Cardiovascular drugs inhibit MMP-9 activity from human THP-1 macrophages

It is now recognized that atherosclerosis complications are related to the unstable character of the plaque rather than its volume. Vulnerable plaques often contain a large lipid core, a reduced content of smooth muscle cells, and accumulation of inflammatory cells. Colocalization of macrophages and active matrix metalloproteinases (MMPs) is likely relevant for atherosclerotic lesion disruption. Nevertheless, MMP activity and regulation by cardiovascular drugs remains poorly defined. In this study, we evaluated the effects of avasimibe, fluvastatin, and peroxisome proliferator-activated receptor (PPAR) ligands on 92-kDa gelatinase B (MMP-9) secretion by human THP-1 macrophages. THP-1 macrophages were treated with compounds for 48 h, and secreted MMP-9 protein was quantified by immunoassay. Avasimibe, fluvastatin, and PPARalpha agonists (fenofibric acid and Wy-14643) significantly reduced, in a concentration-dependent manner, MMP-9 protein (up to 67 +/- 5% for fenofibric acid). In these assays, the PPARgamma selective agonist rosiglitazone displayed a lower efficacy than other compounds. Enzymatic activity of MMP-9 was also decreased by all cardiovascular drugs tested. MMP-9 protein/activity inhibition by cardiovascular drugs was due, at least in part, to a decrease in MMP-9 mRNA. These results show that THP-1 macrophages could be an useful cellular model to investigate effects of compounds on plaque vulnerability through MMP-9 activity.     

IL-15 is highly expressed in inflammatory bowel disease and regulates local T cell-dependent cytokine production

IL-15 shares biological activities but no significant sequence homology with IL-2. It induces T cell recruitment to sites of inflammation, T cell proliferation, and cytokine production and rescue from apoptosis. The aim of this study was to investigate expression of IL-15 and its effects on proinflammatory cytokine production in inflammatory bowel disease (IBD). Immunohistochemistry demonstrated local IL-15 production by macrophages in inflamed mucosa from IBD patients. Isolated lamina propria mononuclear cells from these patients but not from controls produced IL-15 when stimulated with LPS or IFN-gamma. Moreover, lamina propria T cells (LP-T) from IBD patients were more responsive to IL-15 as compared with controls, and IL-15 alone without a primary T cell stimulus induced IFN-gamma and TNF production by isolated IBD LP-T cells, especially by LP-T cells from patients with Crohn's disease. LP-T cells from IBD patients could induce CD40-CD40 ligand (CD40L) interaction-dependent TNF and IL-12 production by monocytes in a coculture system. This capacity of LP-T cells was strongly enhanced by preincubation in IL-15 and was the result of higher CD40L expression after culture in IL-15. These data indicate that IL-15 is overexpressed in the inflamed mucosa in IBD and that IL-15 enhances local T cell activation, proliferation, and proinflammatory cytokine production by both T cells and macrophages, the latter via a CD40-CD40L interaction-dependent mechanism. Treatment directed against IL-15 may have therapeutic potential in IBD.     

Ligand-receptor interactions as controlled by wild-type and mutant Thr(370)Lys alpha2B-adrenoceptor-Galpha15 fusion proteins

Fusion proteins were constructed between either a wild-type or mutant Thr370Lys alpha2B-adrenoceptor (alpha2B AR) and a mouse Galpha15 protein to analyze ligand-receptor interactions at a receptor/Galpha15 protein density ratio of 1. Activation of the wild-type alpha2B AR-Galpha15 fusion protein in CHO-K1 cells by (-)-adrenaline induced a time- and concentration-dependent (pEC50 = 7.37+/-0.13) increase in the intracellular Ca2+ concentration, which could be antagonized by RX 811059 (pK(B) = 7.55+/-0.15). Whereas d-medetomidine and oxymetazoline were as efficacious agonists as (-)-adrenaline, the following ligands displayed partial agonist properties: BRL 44408 < atipamezole < clonidine < UK 14304 < BHT 920. A comparison with the mutant Thr370Lys alpha2B AR-Galpha15 fusion protein displayed similar Ca2+ kinetics and a ligand-mediated receptor activation profile characterized by higher potencies and greater maximal Ca2+ responses for the ligands being investigated, including the putative antagonists dexefaroxan and idazoxan. RX 811059 and RX 821002 remained silent. Similar conclusions could be made on enhancement of the ligands' intrinsic activities by coexpression of the mutant Thr370Lys alpha2B AR with either a Galpha15 or Galphao Cys351Ile protein. The Thr370Lys alpha2B AR-Galpha protein interactions may modify the tertiary structure of the mutant receptor in such a way that some putative alpha2 AR antagonists are capable of stabilizing an active receptor conformation, thereby generating positive efficacy.     

Autoradiography of Serotonin 5-HT1A Receptor-Activated G Proteins in Guinea Pig Brain Sections by Agonist-Stimulated [35S]GTPγS Binding

Abstract: G protein activation mediated by serotonin 5-HT_1A and 5-HT_1B/D receptors in guinea pig brain was investigated by using quantitative autoradiography of agonist-stimulated [³⁵S]GTPγS binding to brain sections. [³⁵S]GTPγS binding was stimulated by the mixed 5-HT_1A/5-HT_1B/D agonist L694247 in brain structures enriched in 5-HT_1A binding sites, i.e., hippocampus (+140 ± 14%), dorsal raphe (+70 ± 8%), lateral septum (+52 ± 12%), cingulate (+36 ± 8%), and entorhinal cortex (+34 ± 5%). L694247 caused little or no stimulation of [³⁵S]GTPγS binding in brain regions with high densities of 5-HT_1B/D binding sites (e.g., substantia nigra, striatum, central gray, and dorsal subiculum). The [³⁵S]GTPγS binding response was antagonized by WAY100635 (10 µM) and methiothepin (10 µM). In contrast, the 5-HT_1B inverse agonist SB224289 (10 µM) did not affect the L694247-mediated [³⁵S]GTPγS binding response, and the mixed 5-HT_1B/D antagonist GR127935 (10 µM) yielded a partial blockade. The distribution pattern of the [³⁵S]GTPγS binding response and the antagonist profile suggest the L694247-mediated response in guinea pig brain to be mediated by 5-HT_1A receptors. In addition to L694247, 8-hydroxy-2-(di-n-propylamino)tetralin, and flesinoxan also stimulated [³⁵S]GTPγS binding; their maximal responses varied between 46 and 52% compared with L694247, irrespective of the brain structure being considered. Sumatriptan, rizatriptan, and zolmitriptan (10 µM) stimulated [³⁵S]GTPγS binding in the hippocampus by 20–50%. Naratriptan, CP122638, and dihydroergotamine stimulated [³⁵S]GTPγS binding to a similar level as L694247 in hippocampus, lateral septum, and dorsal raphe. It appears that under the present experimental conditions, G protein activation through 5-HT_1A but not 5-HT_1B/D receptors can be measured in guinea pig brain sections.     

Nuclear gene trees and the phylogenetic relationships of the mangabeys (Primates: Papionini)

Phylogenetic relationships of mangabeys within the Old World monkey tribe Papionini are inferred from analyses of nuclear DNA sequences from five unlinked loci. The following conclusions are strongly supported, based on congruence among trees derived for the five separate gene regions: (1) mangabeys are polyphyletic within the Papionini; (2) Cercocebus is the sister taxon to the genus Mandrillus; and (3) Lophocebus belongs to a clade with Papio and Theropithecus, with Papio as its most likely sister taxon. Morphologically based phylogenies positing mangabey monophyly were evaluated by mapping the sequences for each locus on these trees. The data seem to fit these trees poorly in both maximum-parsimony and likelihood analyses. Incongruence among nuclear gene trees occurred in the interrelationships among Lophocebus, Papio, and Theropithecus. Several factors that may account for this incongruence are discussed, including sampling error, random lineage sorting, and introgression.