Design and synthesis of some thiazolyl and thiadiazolyl derivatives of antipyrine as potential non-acidic anti-inflammatory,analgesic and antimicrobial agents

The synthesis of two groups of structure hybrids comprising basically the antipyrine moiety attached to either polysubstituted thiazole or 2,5-disubstituted-1,3,4-thiadiazole counterparts through various linkages is described. Twelve out of the newly synthesized compounds were evaluated for their anti-inflammatory activity using two different screening protocols; namely, the formalin-induced paw edema and the turpentine oil-induced granuloma pouch bioassays, using diclofenac Na as a reference standard. The ulcerogenic effects and acute toxicity (ALD₅₀) values of these compounds were also determined. Meanwhile, the analgesic activity of the same compounds was evaluated using the rat tail withdrawal technique. Additionally, the synthesized compounds were evaluated for their in vitro antimicrobial activity. In general, compounds belonging to the thiazolylantipyrine series exhibited better biological activities than their thiadiazolyl structure variants. Collectively, compounds 6, 10, 26, and 27 proved to display distinctive anti-inflammatory and analgesic profiles with a fast onset of action. All of the tested compounds revealed super GI safety profile and are well tolerated by the experimental animals with high safety margin (ALD₅₀ > 3.0 g/kg). Meanwhile, compounds 7, 10, 11, and 23 are considered to be the most active broad spectrum antimicrobial members in this study. Compound 10 could be identified as the most biologically active member within this study with an interesting dual anti-inflammatory analgesic and antibacterial profile.     

Identifying the neural circuitry of alcohol craving and relapse vulnerability

With no further intervention, relapse rates in detoxified alcoholics are high and usually exceed 80% of all detoxified patients. It has been suggested that stress and exposure to priming doses of alcohol and to alcohol-associated stimuli (cues) contribute to the relapse risk after detoxification. This article focuses on neuronal correlates of cue responses in detoxified alcoholics. Current brain imaging studies indicate that dysfunction of dopaminergic, glutamatergic and opioidergic neurotransmission in the brain reward system (ventral striatum including the nucleus accumbens) can be associated with alcohol craving and functional brain activation in neuronal systems that process attentional relevant stimuli, reward expectancy and experience. Increased functional brain activation elicited by such alcohol-associated cues predicted an increased relapse risk, whereas high brain activity elicited by affectively positive stimuli may represent a protective factor and was correlated with a decreased prospective relapse risk. These findings are discussed with respect to psychotherapeutic and pharmacological treatment options.     

Comparison of Immune Restoration in Early versus Late Alpha Interferon Therapy against Hepatitis C Virus

Early alpha interferon (IFN-α) therapy against hepatitis C virus (HCV) rescues polyfunctional, virus-specific memory CD8⁺ T cells, but whether immune restoration is possible during late therapy remains controversial. We compared immune restoration of HCV-specific memory T cells in patients who cleared HCV infection spontaneously and following early or late IFN therapy. Multifunctional CD4⁺ and CD8⁺ memory T cells were detected in spontaneous resolvers and in individuals treated early following an acute infection. In contrast, limited responses were detected in patients treated during chronic infection, and the phenotype of HCV-specific cells was influenced by autologous viral sequences. Our data suggest that irreversible damage to the HCV-specific memory T-cell response is associated with chronic HCV infection.The majority of acute hepatitis C virus (HCV) infections become chronic, with persistent viremia and serious liver complications (12). Alpha interferon (IFN-α)-based therapy is the only approved treatment for chronic HCV; its success rate ranges from 40 to 90% depending on the infecting genotype (9, 18). The success of therapy is characterized by a sustained virological response (SVR), defined as undetectable HCV RNA in plasma at 6 months after termination of therapy. SVR rates are greatly enhanced if therapy is started between 3 and 6 months following acute HCV infection, but the underlying mechanisms are not well understood (27, 28). We have demonstrated that early interferon therapy for HCV can rescue and select for long-lived polyfunctional CD8⁺ memory T cells (1). Treatment-induced memory T cells were similar in phenotype and function to natural memory T cells generated following spontaneously resolved infection. They expressed high levels of CD127 and Bcl-2 (CD127^hi, Bcl-2^hi) and low levels of PD1 (PD1^lo) and were polyfunctional in nature (1). However, restoration of HCV-specific memory CD4⁺ T cells has not been examined. Furthermore, whether immune restoration is possible following the late initiation of therapy during the chronic phase remains controversial. Kamal et al. demonstrated that SVR is associated with a recovery in HCV-specific CD4⁺ T-cell responses (13). In contrast, Barnes et al. and Rahman et al. demonstrated that the induction of HCV-specific immunity during therapy does not correlate with outcomes (2, 21).     

Geographical variation in temporal and spatial vocalization patterns of male harbour seals in the mating season

In the aquatically mating harbour seal, Phoca vitulina, oestrous females show marked differences in spatial and temporal distribution between geographical areas. This suggests that the males' display behaviour may also vary between areas. We recorded male vocalizations in two areas, the Moray Firth and Orkney, U.K. In the Moray Firth, females haul out on a few intertidal sandbars and travel along predictable routes to forage at sea. In Orkney, female haul out sites are much less influenced by tidal availability and females are much more dispersed. In the Moray Firth, males vocalized only during a short mating season, from 1 July to 12 August. Vocalizations varied significantly with the tide, the peak at high tide clearly coinciding with the period when most females were in the water. In contrast, vocalizations in Orkney were significantly related to both tidal and diel patterns. We suggest that the timing of male vocalizations reflects differences in female availability between sites. In the inner Moray Firth, vocalizations were heard throughout the females' range, whereas vocalizations in Orkney were heard only in two discrete areas. However, at both sites the density of vocalizing males was highest in narrow channels and/or along predictable female travel routes. Therefore, males clearly adapt their temporal and spatial behaviour patterns to variations in female distribution and density. These results suggest that male mating strategies in aquatically mating pinnipeds are more variable than was previously envisaged. Copyright 1999 The Association for the Study of Animal Behaviour.     

Age-independent,gray matter-localized,brain-enhanced oxidative stress in male fischer 344 rats: brain levels of F(2)-isoprostanes and F(4)-neuroprostanes

While studies showed that aging is accompanied by increased exposure of the brain to oxidative stress, others have not detected any age-correlated differences in levels of markers of oxidative stress. Use of conventional markers of oxidative damage in vivo, which may be formed ex vivo and/or eliminated by endogenous metabolism, may explain these conflicting results. Recently, F₂-isoprostanes and F₄-neuroprostanes, peroxidation products of arachidonic acid and docosahexaenoic acid, respectively, have been identified as sensitive and reliable markers of oxidative injury. Therefore, this study was designed to quantify brain levels of F₂-isoprostanes and F₄-neuroprostanes and their precursors in 4, 10, 50, and 100 week old male Fischer 344 rats. Data show that levels of F₂-isoprostanes and F₄-neuroprostanes were comparable in all animal age groups. However, levels of F₄-neuroprostanes were approximately 20-fold higher than those of F₂-isoprostanes in all age groups, despite the fact that brain levels of docosahexaenoic acid were only twice as high as those of arachidonic acid. Based on our findings, it is concluded that aging is not accompanied by enhanced brain susceptibility to oxidative stress. Furthermore, the metabolically active gray matter of the brain, where docosahexaenoic acid is abundant, appears more susceptible to oxidative stress than the white matter.     

Variation of Giemsa C-band and fluorochrome banded karyotypes,and relationships inAllium subgen.Molium

The somatic karyotypes of 10 taxa belonging toAllium subgen.Molium (Liliaceae) from the Mediterranean area have been investigated using Giemsa C-band and fluorochrome (Hoechst, Quinacrine) banding techniques. A wide range of banding patterns has been revealed. InAllium moly (2n = 14),A. oreophilum (2n = 16) andA. paradoxum (2n = 16) C-banding is restricted to a region on each side of the nucleolar organisers and the satellites show reduced fluorescence with fluorochromes. The satellites are also C-banded and with reduced fluorescence inA. triquetrum (2n = 18), but two other chromosome pairs also have telomeric bands which are not distinguished by fluorochrome treatment. InA. erdelii (2n = 16) 4 pairs of metacentric chromosomes have telomeric C-bands while 2 pairs of telocentric chromosomes have centromeric C-banding. InA. subhirsutum (2n = 14),A. neapolitanum (2n = 28),A. trifoliatum subsp.hirsutum (2n = 14) andA. trifoliatum subsp.trifoliatum (2n = 21) chromosomes with long centromeres, consisting of a centromere and nucleolar organiser are positively C-banded on each side of the constriction. InA. subhirsutum banding is confined to the pair of chromosomes with this feature, whereas inA. neapolitanum one additional chromosome pair has telomeric bands and inA. trifoliatum there are varying numbers of chromosomes with centromeric and telomeric bands, depending on the subspecies.A. zebdanense (2n = 18) shows no C-bands. The banding patterns in this subgenus are compared with those recorded for otherAllium species and with the sectional divisions in the genus. Evidence from the banding patterns for allopolyploidy inA. trifoliatum subsp.trifoliatum andA. neapolitanum is discussed.     

Analysis of Binding Interaction Between Antibacterial Ciprofloxacin and Human Serum Albumin by Spectroscopic Techniques

To develop an efficient method for extracting and purifying the active ingredient, arctiin, from Fructus arctii and to investigate the protective effect of arctiin against glucose-induced rat aortic endothelial cell (RAEC) injury was investigated. Using a L9 (34) orthogonal array and two-step column chromatography (with AB-8 macroporous resin) arctiin extraction was optimized using a reflux method with 70 % ethanol. The RAECs were then treated with different concentrations of arctiin (1, 10, or 100 μg/ml). The effects of arctiin on cell viability in a high glucose medium, malondialdehyde (MDA) levels, and lactate dehydrogenase were measured using commercially available assays. After extraction, the purity of arctiin reached 95.7 %. In rats, arctiin was shown to stimulate the proliferation of RAECs in a high glucose medium in a dose-dependent manner. Exposure of RAECs to high glucose resulted in a significant increase in MDA and release of lactate dehydrogenase. This was accompanied by significant increase in nitric oxide release and expression of antiendothelial nitric oxide synthase. This technique resulted in relatively pure arctiin extraction. Furthermore, the results from this study suggest that arctiin could potentially function as a protector against vascular endothelial cell injury and further investigation is warranted.     

Ionizing radiation-induced instant pairing of heterochromatin of homologous chromosomes in human cells

Using fluorescence in situ hybridization with human band-specific DNA probes we examined the effect of ionizing radiation on the intra-nuclear localization of the heterochromatic region 9q12-->q13 and the euchromatic region 8p11.2 of similar sized chromosomes 9 and 8 respectively in confluent (G1) primary human fibroblasts. Microscopic analysis of the interphase nuclei revealed colocalization of the homologous heterochromatic regions from chromosome 9 in a proportion of cells directly after exposure to 4 Gy X-rays. The percentage of cells with paired chromosomes 9 gradually decreased to control levels during a period of one hour. No significant changes in localization were observed for chromosome 8. Using 2-D image analysis, radial and inter-homologue distances were measured for both chromosome bands. In unexposed cells, a random distribution of the chromosomes over the interphase nucleus was found. Directly after irradiation, the average inter-homologue distance decreased for chromosome 9 without alterations in radial distribution. The percentage of cells with inter-homologue distance <3 micro m increased from 11% in control cells to 25% in irradiated cells. In contrast, irradiation did not result in significant changes in the inter-homologue distance for chromosome 8. Colocalization of the heterochromatic regions of homologous chromosomes 9 was not observed in cells irradiated on ice. This observation, together with the time dependency of the colocalization, suggests an underlying active cellular process. The biological relevance of the observed homologous pairing remains unclear. It might be related to a homology dependent repair process of ionizing radiation induced DNA damage that is specific for heterochromatin. However, also other more general cellular responses to radiation-induced stress or change in chromatin organization might be responsible for the observed pairing of heterochromatic regions.     

A limited survey of aflatoxins and fumonisins in retail maizebased products in the UK using immunoassay detection

A total of 27 maize-based products destined for human consumption were collected from retail outlets within the city of Glasgow in the UK and were analysed for the presence of aflatoxins using immunoaftinity column chromatography with fluorescence detection and for fumonisins by competitive ELISA. Aflatoxins were detected at a trace level below 4 in eight (30%) of the 27 samples tested, no sample contained aflatoxins at a high level although one sample of sweetcorn did contain aflatoxins at a level of 5-10 Fumonisins were detected in eight (30%) of the samples at levels from 1 to 8mgkg^-1 and a further eight samples contained fumonisin at a level below 1 mgkg^-1 but above the detectable level. The highest concentration of fumonisins was found in a sample of fine corn meal at 8-12mgkg^-1.