Melanoma cell growth inhibition by beta gamma-CAT, which is a novel non-lens betagamma-crystallin and trefoil factor complex from frog Bombina maxima skin

In vertebrates, non-lens beta gamma-crystallins are widely expressed in various tissues but their functions are unknown. The molecular mechanisms of trefoil factors, initiators of mucosal healing and being greatly involved in tumorigenesis, have remained

Inhibition of seafood-borne bacteria in cooked mackerel (Rastrelliger kanagurta) fish meat by lactic acid bacteria

Antagonistic activity of lactic acid bacteria (LAB) namely Streptococcus faecalis, Pediococcus cerevisiae and Lactobacillus casei was tested against seafood-borne bacteria such as Staphylococcus aureus, Bacillus cereus, Escherichia coli, Clostridium perfringens and Listeria monocytogenes. Three lactic acid bacteria such as Streptococcus faecalis, Lactobacillus casei and Pediococcus cerevisiae were coated on cooked mackerel meat, individually and in combination against fish-borne bacteria. S. faecalis inhibited C. perfringens in individual coat by 3.7 log units as compared to control, whereas L. casei did not inhibit C. perfringens. P. cerevisiae inhibited S. aureus by 5 log units. L. casei, inhibited L. monocytogenes by 3.3 log units on the third day of storage as compared to control. On the other hand, S. aureus and B. cereus were inhibited on the third and second day by 4.9 log and 5.2 log units respectively. B. cereus, S. aureus, L. monocytogenes were the most sensitive to all three LAB. C. perfringens was the least inhibited among all the seafood-borne bacteria tried. Multiple LAB or LAB strains in combination showed much earlier inhibitory activity on seafood-borne bacteria than single LAB coat.

Synthesis and HIV-1 integrase inhibition activity of some N-arylindoles

Eight simple N-arylindoles were designed, synthesized and evaluated as human immunodeficiency virus (HIV)-1 integrase inhibitors in vitro for the first time. Among these compounds, 3b, 3e and 3g demonstrated significant anti-HIV-1 integrase activity. Espe

Effect of adrenalectomy and corticosterone replacement on prepulse inhibition and locomotor activity in mice

1 Stress is a risk factor in psychiatric illnesses such as schizophrenia. The aim of the present study was to investigate the effect of different circulating levels of the adrenal steroid corticosterone (CORT) on locomotor hyperactivity and prepulse inhibition of acoustic startle, two behavioural animal models of aspects of schizophrenia. 2 Male C57BL/6J mice (n = 10 per group) were anaesthetised with isoflurane and sham-operated or adrenalectomised (ADX). ADX mice were implanted with 50 mg pellets consisting of 100% cholesterol, or 2, 10 or 50 mg of CORT mixed with cholesterol. CORT pellet implantation dose dependently increased plasma CORT levels 3 weeks after surgery. Starting 1 week after surgery, mice were tested for prepulse inhibition after injection of saline or 5 mg kg(-1) of haloperidol. 3 In intact mice and in mice implanted with 10 mg of CORT, haloperidol treatment significantly increased prepulse inhibition (average values from 38 - 42 to 52%). Similar results were observed when testing the mice for amphetamine-induced locomotor hyperactivity (5 mg kg(-1)). In contrast, there was no significant effect of haloperidol in mice implanted either with cholesterol or 2 or 50 mg of CORT. 4 These results in behavioural animal models of schizophrenia suggest an important role of the stress hormone CORT in modulating dopaminergic activity in this illness.

Environmental enrichment and chronic restraint stress in ICR mice: Effects on prepulse inhibition of startle and Y-maze spatial recognition memory

In most studies regarding the improving or therapeutical effects induced by enriched environment (EE), EE was performed after the stress treatment or in patients with certain diseases. In the current study, the effects of chronic restraint stress (6 h/day) in mice living in an enriched environment or standard environment (SE) were tested. Mice were randomly divided into 4 groups: non-stressed or stressed mice housed in SE or EE conditions (SE, stress + SE, EE, stress + EE). Prepulse inhibition (PPI) of startle was tested after the 2 weeks or 4 weeks stress and/or EE treatment and 1 or 2 weeks withdrawal from the 4 weeks treatment. After the 4 weeks treatment, spatial recognition memory in Y-maze was also tested. The results showed that EE increased PPI in stressed and non-stressed mice after 2 weeks treatment. No effect of EE on PPI was found after the 4 weeks treatment. 4 weeks chronic restraint stress increased PPI in mice housed in standard but not EE conditions. Stressed mice showed deficits on the 1 h delay version of the Y-maze which could be prevented by living in an enriched environment. Our results indicated that living in an enriched environment reversed the impairing effects of chronic restraint stress on spatial recognition memory. However, EE did not change the effects of stress on PPI. (C) 2010 Elsevier B.V. All rights reserved.

Interaction of corticosterone and nicotine in regulation of prepulse inhibition in mice

The aim of the present Study was to investigate if different levels of circulating corticosterone (CORT) modulate the effect of nicotine on prepulse inhibition (PPI), a measure of sensorimotor gating that is disrupted in schizophrenia and other mental illnesses. Four groups of mice were investigated: sham-operated, adrenalectomized (ADX) and implanted with a cholesterol pellet, ADX and implanted with a 10 mg CORT pellet, or ADX and 50 mg, of CORT. Different CORT levels or doses of nicotine did not significantly affect startle responses. Baseline PPI was significantly reduced in mice implanted with the highest dose of CORT. In ADX mice implanted with cholesterol, nicotine treatment influenced PPI depending on the prepulse intensity. In ADX mice implanted with 50 mg of CORT, treatment with 10 mg/kg of nicotine caused a significant increase in PPI at all prepulse intensities. Binding studies showed that corticosterone treatment had significantly affected nicotinic acetylcholine receptor (nAChR) density in the mouse brain. Treatment with 50 mg CORT decreased I-125-epibatidine binding in the globus pallidus and I-125-alpha-bungarotoxin binding in the claustrum. These results suggest a possible interaction of corticosterone and nicotine at the level of the alpha4- and alpha7-type nAChR in the regulation of PPI. In situations of high circulating levels of corticosterone, nicotine may be beneficial to restore disruption of PPI. (C) 2004 Elsevier Ltd. All rights reserved.

Glycine uptake regulates hippocampal network activity via glycine receptor-mediated tonic inhibition

Functional glycine receptors (GlyRs) are enriched in the hippocampus, but their role in hippocampal function remains unclear. Since the concentration of ambient glycine is determined by the presence of powerful glycine transporter (GlyT), we blocked the r

Inhibitory plasticity balances excitation and inhibition in sensory pathways and memory networks

Cortical neurons receive balanced excitatory and inhibitory synaptic currents. Such a balance could be established and maintained in an experience-dependent manner by synaptic plasticity at inhibitory synapses. We show that this mechanism provides an explanation for the sparse firing patterns observed in response to natural stimuli and fits well with a recently observed interaction of excitatory and inhibitory receptive field plasticity. The introduction of inhibitory plasticity in suitable recurrent networks provides a homeostatic mechanism that leads to asynchronous irregular network states. Further, it can accommodate synaptic memories with activity patterns that become indiscernible from the background state but can be reactivated by external stimuli. Our results suggest an essential role of inhibitory plasticity in the formation and maintenance of functional cortical circuitry.

Inhibition of no tail (ntl) gene expression in zebrafish by external guide sequence (EGS) technique

External guide sequence (EGS) technique, a branch of ribozyme strategy, can be enticed to cleave the target mRNA by forming a tRNA-like structure. In the present study, no tail gene (ntl), a key gene participating in the formation of normal tail, was used as a target for ribonuclease (RNase) P-mediated gene disruption in zebrafish in vivo. Transient expression of pH1-m3/4 ntl-EGS or pH1-3/4 ntl-EGS produced the full no tail phenotype at long-pec stage in proportion as 24 or 35%, respectively. As is expected that the full-length ntl mRNA of embryos at 50% epiboly stage decreased relative to control when injected the embryos with 3/4 EGS or m3/4 EGS RNA. Interestingly, ntl RNA transcripts, including the cleaved by EGS and the untouched, increased. Taken together, these results indicate that EGS strategy can work in zebrafish in vivo and becomes a potential tool for degradation of targeted mRNAs.

Inhibition of progesterone receptor activity in recombinant yeast by soot from fossil fuel combustion emissions and air particulate materials

Numerous environmental pollutants have been detected for estrogenic activity by interacting with the estrogen receptor, but little information is available about their interactions with the progesterone receptor. In this study, emission samples generated by fossil fuel combustion (FFC) and air particulate material (APM) collected from an urban location near a traffic line in a big city of China were evaluated to interact with the human progesterone receptor (hPR) signaling pathway by examining their ability to interact with the activity of hPR expressed in yeast. The results showed that the soot of a petroleum-fired vehicle possessed the most potent anti-progesteronic activity, that of coal-fired stove and diesel fired agrimotor emissions took the second place, and soot samples of coal-fired heating work and electric power station had lesser progesterone inhibition activity. The anti-progesteronic activity of APM was between that of soot from petroleum-fired vehicle and soot from coal-fired establishments and diesel fired agrimotor. Since there was no other large pollution source near the APM sampling sites, the endocrine disrupters were most likely from vehicle emissions, tire attrition and house heating sources. The correlation analysis showed that a strong relationship existed between estrogenic activity and anti-progesteronic activity in emissions of fossil fuel combustion. The discoveries that some environmental pollutants with estrogenic activity can also inhibit OR activity indicate that further studies are required to investigate potential mechanisms for the reported estrogenic activities of these pollutants. (c) 2005 Elsevier B.V. All rights reserved.

Inhibition of the predatory activity of the copepod Mesocyclops notius by Microcystis spp.

The feeding rate of the copepod Mesocyclops notius on two species of cladocerans (Daphnia carinata and Ceriodaphnia cornuta) decreased with increasing environmental concentration of 64-122 mum colonial Microcystis spp. Rate of copepod feeding on Moina micrura was unaffected by the presence of Microcystis spp. Mesocyclops notius rarely preyed on Diaphanosoma brachyurum.

Comparative study on in vitro inhibition of grass carp (Ctenopharyngodon idellus) and mouse protein phosphatases by microcystins

Microcystins isolated from toxic cyanobacteria are potent inhibitors of protein phosphatases 1 and 2A (PP1 and PP2A). The inhibitory effects of three structural variants of microcystins (microcystin-LR, -YR, and -RR) on protein phosphatases isolated and purified from the liver and kidney of grass carp (Ctenopharyngodon idellus) were investigated using the P-32 radiometric assay. The relationships between percentage inhibition of protein phosphatase activity and microcystin levels followed a typical dose-dependent sigmoid curve. These results were compared to those obtained from mouse PP2A. The degree and pattern of inhibition of both fish and mouse protein phosphatases by microcystins were similar. Protein phosphatases in crude fish tissue homogenates showed similar inhibition patterns as purified fish PP2A toward microcystins. (C) 2000 by John Wiley & Sons, Inc.

A settlement inhibition assay with cyprid larvae of the barnacle Balanus amphitrite

A settlement inhibition assay using barnacle cyprid larvae, Balanus amphitrite, was developed with Cd2+ and phenol as standard reference toxicants. Mean percentage settlement of cyprid larvae showed a progressive reduction with increasing concentrations of Cd2+ and phenol. A significant reduction in settlement was found when cyprids were exposed to 0.1 mgL(-1) Cd2+ or 10 mgL(-1) phenol. The assay was used to assess the sublethal toxicity of three oil dispersants (Vecom B-1425 GL, Norchem OSD-570 and Corexit 9905) commonly used in Hong Kong waters. Results of this investigation show that the barnacle settlement inhibition assay can be incorporated into the battery of tests currently available for ecotoxicological assessment of marine contaminants. (C) 1997 Elsevier Science Ltd.

A phototaxis inhibition assay using barnacle larvae

The effects of sublethal concentrations of phenol and cadmium on the phototactic responses of the stage II nauplii of the barnacle Balanus amphitrite were investigated. Increased toxicant concentrations caused a reduction in phototactic responses. Balanus amphitrite nauplii exposed to nominal phenol concentrations of 100 ppm and higher for 1-12 h failed to exhibit phototactic responses, while longer exposure times of 24 and 48 h reduced the lowest observable effect concentration (LOECs) to 80 and 60 ppm, respectively. For cadmium, the LOECs, based on nominal concentrations, for B. amphitrite following 1, 6, 12, 24, and 48 h exposures were 20, 4.5, 4.0, 1, and 0.75 ppm, respectively. The LOECs can be significantly reduced by increasing the duration of exposure to the toxicants. A good relationship exists between the phototactic response and toxicant concentration as well as exposure time. Results of this study indicate that the toxicant-induced reduction in phototactic responses of barnacle larvae can be used in a sensitive, rapid screening test for ecotoxicological assessments. (C) 1997 by John Wiley & Sons, Inc.