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Physiological Activity (physiological + activity)
Selected AbstractsTemperature Effects on Anti-Predator Behaviour in Rhabdophis tigrinus, a Snake with Toxic Nuchal GlandsETHOLOGY, Issue 9 2001Akira Mori Many contextual factors affect the anti-predator behaviour of animals. In ectotherms, in which most physiological activities depend on body temperature, ambient temperature is one of the most important of these factors. We examined the effects of temperature on the anti-predator behaviour of an ectotherm, the Japanese grass snake (Rhabdophis tigrinus). This species has a large repertoire of anti-predator behavioural responses. Among these responses are several anti-predator displays that appear to be unique to this species and perhaps others in a small group of closely related species possessing nuchal glands containing toxic secretions that may be derived from their toxic toad diet. Snakes were tested at room temperatures of 14, 22 and 30°C with order of temperatures balanced. A long wand modified to simulate initial contact by a predator was used as the stimulus. Snakes exhibited rather passive responses (neck flatten, body flatten, neck arch and immobile) more frequently at low temperatures, and fled more frequently at high temperatures. The dorsal facing posture, a characteristic posture directed against the stimulus, was observed more frequently at low temperatures. Threatening, assertive responses such as strike were rarely observed. These results showed that R. tigrinus shifts its anti-predator behaviour from multiple passive responses to active flight responses with increasing temperature. This snake species thus appears to rely more on its nuchal glands as a predator deterrent at low ambient temperatures. Consistent individual variation was also observed, and its adaptive and causal bases are discussed. [source] Effects of azadirachtin and of simpler epoxy-alcohols on survival and behaviour of Galleria mellonella (Lepidoptera)JOURNAL OF APPLIED ENTOMOLOGY, Issue 7 2007C. Charbonneau Abstract:, Investigations into the toxicity of three simpler molecules based on the epoxy-alcohol fragment of azadirachtin have revealed insecticidal activity on the greater wax moth Galleria mellonella L. larvae. The simpler epoxy-alcohols doses giving 50% mortalities (LD50) for G. mellonella larvae were in the increasing order from glycidol (0.022 mg/g), 4,5-epoxy-2-pentanol (0.068 mg/g) and finally, glycerol diglycidyl ether (0.147 mg/g). The three epoxy-alcohols exhibited higher insecticidal activity when compared with the commercial neem product for which the dose giving 50% mortalities was 10.6 mg/g and to azadirachtin that killed the larvae only by injection (dose of 0.20 mg/g of larvae body weight). Our results confirm the importance of the epoxy-alcohol junction between the two parts of the azadirachtin molecule for the biological activity. Other effects of the epoxy-alcohols tested were blackening of larvae and morphological deformities of some adults hatching. In future, the molecules should be complexified (degree of ramification, length of chain and presence of bulky ramified substituent) to obtain an insecticide as toxic for insects only and environmentally safe as azadirachtin but more stable, and their physiological activities on insect's tissues and cells should be studied. [source] REPRODUCTIVE ISOLATION BY SEX PHEROMONES IN THE CLOSTERIUM PERACEROSUM,STRIGOSUM,LITTORALE COMPLEX (ZYGNEMATALES, CHAROPHYCEAE),JOURNAL OF PHYCOLOGY, Issue 5 2008Yuki Tsuchikane The Closterium peracerosum,strigosum,littorale (C. psl.) complex consists of unicellular algae and is known to be composed of several reproductively isolated mating groups of heterothallic strains. Group I-E is completely isolated from mating groups II-A and II-B, groups II-A and II-B are partially isolated from each other, and only mating-type plus (mt+) cells of group II-A and mating-type minus (mt,) cells of group II-B form zygotes. Based on the alignment of 1506 group I introns, significant phylogenetic relationships were observed among mating groups II-A and II-B, while mating group I-E was distant from groups II-A and II-B. Sexual cell division in both mating-type cells of group II-A was stimulated in conditioned media in which cells of group II-B had been cultured. When mt, cells of group II-B were stimulated in conditioned medium derived from group II-A, mt+ cells of group II-B did not respond to the conditioned medium. Conditioned media derived from group I-E did not exhibit sexual cell division (SCD),inducing activity against any strain except those within its own group. From the alignment of deduced amino acid sequences from orthologous protoplast-release-inducing protein (PR-IP) Inducer genes, we detected a significant similarity among groups II-A and II-B, and mating group I-E had low similarity to other mating groups. The existing degree of reproductive isolation can be partially explained by differences in molecular structures and physiological activities of sex pheromones of these heterothallic mating groups. [source] Preparation and antioxidant activity of wheat gluten hydrolysates (WGHs) using ultrafiltration membranesJOURNAL OF THE SCIENCE OF FOOD AND AGRICULTURE, Issue 5 2008Xiangzhen Kong Abstract BACKGROUD: Many hydrolysates from animal and plant proteins have been found to possess physiological activities. Wheat gluten, an important by-product of the wheat starch industry, is produced worldwide in enormous quantities. In this study, wheat gluten hydrolysates (WGHs) were obtained by enzymatic hydrolysis and fractionated using ultrafiltration membranes. The antioxidant activities of the hydrolysates were investigated by various antioxidant assays, including the ability to inhibit the autoxidation of linoleic acid and the scavenging effect on free radicals. Amino acid composition and molecular weight distribution were also evaluated to determine their relationship with antioxidant activity. RESULTS: The pepsin hydrolysate (PeWGH) had the highest activity and was ultrafiltrated into three major types, PeWGH I (5,10 kDa), PeWGH II (3,5 kDa) and PeWGH III (<3 kDa). PeWGH III showed stronger inhibition of the autoxidation of linoleic acid and higher scavenging activity against 2,2-diphenyl-1-picrylhydrazyl, superoxide and hydroxyl free radicals. Furthermore, PeWGH III had the highest total hydrophobic amino acid content (45.11 g per 100 g protein), and its molecular weight distribution ranged from 1700 to 100 Da. CONCLUSION: The low molecular weight and amino acid composition of PeWGHs were found to be strongly correlated with their antioxidant activity. PeWGH could be used as a natural antioxidant in the pharmaceutical and food industries in the future. Copyright © 2008 Society of Chemical Industry [source] Potential of resveratrol in anticancer and anti-inflammatory therapyNUTRITION REVIEWS, Issue 8 2008Chibuike C Udenigwe Phytochemicals present in food have shown significant prospects in the treatment and management of a vast array of human diseases. Resveratrol is a stilbene-type aromatic phytoalexin predominantly found in grapes, peanuts, berries, turmeric, and other food products. Resveratrol has been reported to exhibit several physiological activities including anticancer and anti-inflammatory activities in vitro and in experimental animal models, as well as in humans. Anticancer activity of this compound is mainly due to induction of apoptosis via several pathways, as well as alteration of gene expressions, all leading to a decrease in tumor initiation, promotion, and progression. Resveratrol exhibits anti-inflammatory activity through modulation of enzymes and pathways that produce mediators of inflammation and also induction of programmed cell death in activated immune cells. Resveratrol has been shown to produce no adverse effects, even when consumed at high concentrations. Hence, resveratrol possesses good potential to be used as an adjunctive or alternative therapy for cancer and inflammatory diseases. [source] An integrated database of flavonoidsBIOFACTORS, Issue 3 2006Takashi Kinoshita Abstract Flavonoids are polyphenolic compounds that occur ubiquitously in foods of plant origin. Some of these molecules exhibit various physiological activities. Among existing drugs, there are a huge number of compounds bearing a flavonoid-related skeleton. Because of the relevance for pharmaceutical research, it would be beneficial to collect these compounds into a database. Recently, various databases of chemicals were compiled to help biological and/or chemical research, but no comprehensive database of flavonoids with chemical structures and physicochemical parameters, supposedly related to their activity, is available yet. The aim of this research was to merge the information about flavonoids of plant origin and flavonoids used as medicines into a database. Moreover, predictions of activities against various targets were performed using a virtual screening procedure to demonstrate a possible application of the database for pharmaceutical research. [source] The role of thymidine phosphorylase, an angiogenic enzyme, in tumor progressionCANCER SCIENCE, Issue 11 2004Shin-ichi Akiyama Thymidine phosphorylase (TP), an enzyme involved in pyrimidine metabolism, is identical with an angiogenic factor, platelet-derived endothelial cell growth factor (PD-ECGF). TP is overex-pressed in various tumors and plays an important role in angiogenesis, tumor growth, invasion and metastasis. The enzymatic activity of TP is required for the angiogenic effect of TP. A novel, specific TP inhibitor, TPI, inhibits angiogenesis induced by overexpression of TP in KB/TP cells (human KB epidermoid carcinoma cells transfected with TP cDNA), as well as the growth and metastasis of KB/TP cells in vivo. 2-Deoxy-D-ribose, the degradation product of thymidine generated by TP activity, has both angiogenic and chemotactic activity. Both 2-deoxy-D-ribose and TP inhibit a hypoxia-induced apoptotic pathway. These findings suggest that 2-deoxy-D-ribose is a downstream mediator of TP function. 2-Deoxy-L-ribose, a stereoisomer of 2-deoxy-D-ribose, inhibits the promotion of angiogenesis, tumor growth and metastasis by TP. Although the mechanism of the action of 2-deoxy-D-ribose is still unknown, 2-deoxy-L-ribose may inhibit the physiological activities of 2-deoxy-D-ribose, and consequently those of TP. Inhibition of TP activity and function appears to be a promising approach for the chemotherapy of various tumors. [source] On the differential lipolytic capabilities of rat spleen and cardiac muscle.CELL BIOCHEMISTRY AND FUNCTION, Issue 2 2007An in vitro incubation in conjunction with chromatographic, densitometric analysis Abstract The phospholipid profiles of newborn, young adult and aged rat heart and spleen and their in vitro response to endogenous phospholipases at pH 7.4 and 38°C for 60,min were analysed by thin layer chromatography (TLC) technology and densitometry measurement. The noticeable high level of cardiolipin (CL) and its preferential deacylation, as detected by the formation of monolysocardiolipin (MLCL) and concurrent reduction of CL level were the most prevalent lipolytic events of rat cardiac muscle (newborn, young adult and aged) but the least prevalent in rat spleen. The level of ethanolamine plasmalogen (PE) was high in both the rat spleen and cardiac muscle (newborn, young adult and aged). Following in vitro incubation, the reduction in the level of PE and the high level of lyso alkenyl PE produced were most conspicuous in rat spleen (newborn, young adult and aged) and noticeably less in rat cardiac muscle. These data clearly illustrate the differential response of the endogenous substrates (phospholipids) to the endogenous phospholipases of these two tissues, and probably are related to their physiological activities in vivo. Copyright © 2006 John Wiley & Sons, Ltd. [source] A New Frontier in Soy Bioactive Peptides that May Prevent Age-related Chronic DiseasesCOMPREHENSIVE REVIEWS IN FOOD SCIENCE AND FOOD SAFETY, Issue 4 2005Wenyi Wang ABSTRACT During gastrointestinal digestion or food processing of proteins, small peptides can be released and may act as regulatory compounds with hormone-like activities. Numerous biologically active peptides (bioactive peptides) have been identified. Most bioactive peptides are derived from milk and dairy products, with the most common being angiotensin converting enzyme inhibitory peptides. Soybean protein and soybean derived peptides also play an important role in soybean physiological activities, particularly those related to the prevention of chronic diseases. However, the bioactive potential of soybean derived bioactive peptides is yet to be fully appreciated. After a general introduction of approaches and advances in bioactive peptides from food sources, this review focuses on bioactive peptides derived from soybean proteins and their physiological properties. Technological approaches to generate bioactive peptides, their isolation, purification, characterization, and quantification, and further application in food and drug design are also presented. Safety concerns, such as potential toxicity, allergenicity, and sensory aspect of these peptides are likewise discussed. [source] CE-ESI-MS/MS as a rapid screening tool for the comparison of protein,ligand interactionsELECTROPHORESIS, Issue 7 2010Thomas Hoffmann Abstract In drug development, the combinatorial synthesis of drug libraries is common use, therefore efficient tools for the characterization of drug candidates and the extent of interaction between a drug and its target protein is a central question of analytical interest. While biological activity is tested today by enzyme assays, MS techniques attract more and more attention as an alternative for a rapid comparison of drug,target interactions. CE enables the separation of proteins and drug,enzyme complexes preserving their physiological activity in aqueous media. By hyphenating CE with ESI-MS/MS, the binding strength of enzyme inhibitors can be deduced from MS/MS experiments, which selectively release the inhibitor from the drug,target complex after CID. In this study, ,-chymotrypsin (CT), a serine protease, was chosen as a model compound. Chymostatin is a naturally occurring peptide aldehyde binding to CT through a hemiacetal bond and electrostatic interaction. First, a CE separation was developed, which allows the analysis of ,-CT and a chymotrypsin,chymostatin complex under MS-compatible conditions. The use of neutral-coated CE capillaries was mandatory to reduce analyte,wall interactions. ESI-quadrupole ion trap-MS was worked out to demonstrate the selective drug release after CID. Fragmentation of the drug,enzyme complex was monitored in dependence from the excitation energy in the ion trap, leading to the V50 voltage that enables 50% complex fragmentation as a reference value for chymotrypsin,chymostatin complex. A stable CE-ESI-MS/MS setup was established, which preserves the drug,enzyme complexes during ionization,desolvation processes. With this optimized setup, different CT inhibitors could be investigated and compared. [source] Effects of fire on surface carbon, energy and water vapour fluxes over campo sujo savanna in central BrazilFUNCTIONAL ECOLOGY, Issue 6 2003A. J. B. Santos Summary 1Tower-based eddy covariance measurements were used to quantify the effect of fire on subsequent carbon dioxide fluxes and water and surface energy balance characteristics for campo sujo savanna located near Brasília in Central Brazil (15°56, S, 47°51, W). Campo sujo is a xeromorphic, open shrub savanna with very scattered but definitely visible shrubs and tree-like shrub elements. We studied two areas, one exposed to a prescribed fire late in the dry season, and a second that had not been burned for the previous 4 years. 2The fire on 22 September 1998 consumed an estimated 26 mol C m,2. Immediately after the fire, evapotranspiration rates decreased and the savanna became a stronger net source of CO2 to the atmosphere. This was attributed to the removal of the still slightly physiologically active grass layer and higher soil CO2 efflux rates as a consequence of elevated surface soil temperatures post-burning. 3On the commencement of the first rains in early October 1998, this situation was reversed, with the burned area rapidly becoming a stronger sink for CO2 and with higher evapotranspiration rates than a nearby unburned (control) area. This difference persisted throughout the wet season (until at least June 1999) and was attributable to greater physiological activity of the regrowing vegetation in the burned area. Early in the growing season, higher soil evaporation rates may also have contributed to faster water use by the previously burned area. 4Overall, we estimate an annual gross primary productivity for the burned area of 135 mol C m,2 year,1, with that for the unburned area being 106 mol C m,2 year,1. Estimated ecosystem respiration rates were more similar on an annual basis (96 and 82 mol C m,2 year,1 for the burned and unburned areas, respectively), giving rise to a substantially higher net ecosystem productivity for the previously burned area (38 vs 24 mol C m,2 year,1). 5Stimulation of photosynthetic activity in the rapid post-fire growth phase means that the negative effects of fire on the ecosystem carbon balance were more or less neutralized after only 12 months. [source] Anatomical perspectives on adult neural stem cellsJOURNAL OF ANATOMY, Issue 3 2005C. Watts Abstract The concept of stem cells within the adult brain is not new. However, only recently have scientific techniques become sufficiently advanced to identify them although this remains problematic and the technology is still developing. Nevertheless, it is now generally recognized that stem cells are restricted to two germinal regions within the intact brain. From here they can migrate to specific destinations where they integrate with existing circuitry. Their identity remains controversial but a growing body of evidence suggests it may have an astrocytic phenotype. Within the germinal regions the stem cells are confined to a niche environment and are capable of responding to environmental signals generated locally in an autocrine or paracrine fashion. The niche environment is also modulated by more generalized systemic and physiological activity. These observations are exciting in their own right and form the basis of this review. They are also beginning to alter how we think about neural injury and disease and to impact on the development of novel therapies. [source] Profiling bacterial survival through a water treatment process and subsequent distribution systemJOURNAL OF APPLIED MICROBIOLOGY, Issue 1 2005D. Hoefel Abstract Aims:, To profile fractions of active bacteria and of bacteria culturable with routine heterotrophic plate count (HPC) methods through a typical water treatment process and subsequent distribution system. In doing so, investigate how water treatment affects both bacterial abundance and diversity, and reveal the identities of active bacteria not detected by traditional HPC culture. Methods and Results:, Profiling active fractions was performed by flow cytometric cell sorting of either membrane-intact (BacLightTM kit) or enzymatically active (carboxyfluorescein diacetate, CFDA) bacteria, followed by eubacterial 16S rDNA-directed PCR and denaturing gradient gel electrophoresis (DGGE). Water treatment significantly reduced active bacterial numbers detected by the BacLightTM kit and CFDA assay by 2·89 and 2·81 log respectively. Bacterial diversity was also reduced from >20 DGGE bands in the active fractions of reservoir water to only two bands in the active fractions of finished water. These two bands represented Stenotrophomonas maltophila, initially culturable by HPC, and a Burkholderia -related species. Both species maintained measurable traits of physiological activity in distribution system bulk water but were undetected by HPC. Conclusions:, Flow cytometric cell sorting with PCR-DGGE, to assess water treatment efficacy, identified active bacteria from a variety of major phylogenetic groups undetected by routine HPC. Following treatment S. maltophila and a Burkholderia -related species retained activity and entered distribution undetected by HPC. Significance and Impact of the Study:, Methods used here demonstrate how water treatment operators can better monitor water treatment plant efficacy and assess distribution system instability by the detection and identification of active bacteria recalcitrant to routine HPC culture. [source] Radial growth responses to drought of Pinus sylvestris and Quercus pubescens in an inner-Alpine dry valleyJOURNAL OF VEGETATION SCIENCE, Issue 6 2007Pascale Weber Abstract Question: Lower montane treeline ecotones such as the inner Alpine dry valleys are regarded as sensitive to climate change. In the dry Valais valley (Switzerland) the composition of the widespread, low altitude Pinus forests is shifting towards a mixed deciduous state. The sub-boreal P. sylvestris shows high mortality rates, whereas the deciduous sub-mediterranean Quercus pubescens is spreading. These species may act as early indicators of climate change. We evaluate this hypothesis by focusing on their differences in drought tolerance, which are hardly known, but are likely to be crucial in the current forest shift and also for future forest development. Methods: We used dendroecological methods to detect species-specific patterns in the growth response to drought. The relationship between radial growth of 401 trees from 15 mixed stands and drought was analysed by calculating response functions using yearly tree-ring indices and monthly drought indices. PCA was applied to the response ratios to discover spatial patterns of drought response. Results: A species-specific response to moisture as well as a sub-regional differentiation of the response patterns were found. While Quercus showed a response mainly to the conditions of the previous autumn and those of current spring, Pinus did not start responding before May, but showed responses throughout the whole summer. Quercus may restrict physiological activity to moist periods; growth of Pinus was much more dependent on prior growth. Conclusions: Given that the climate is changing towards (1) longer summer drought periods, (2) higher mean temperatures and (3) shifted seasonally of moisture availability, Quercus may benefit from adapting better to drier conditions. Pinus may increasingly face problems related to drought stress as it depends on summer moisture and has a smaller adaptive capacity due to its long-lived photosynthetic tissue. [source] Structure and Photoreaction of Photoactive Yellow Protein, a Structural Prototype of the PAS Domain Superfamily,PHOTOCHEMISTRY & PHOTOBIOLOGY, Issue 1 2007Yasushi Imamoto Photoactive yellow protein (PYP) is a water-soluble photosensor protein found in purple photosynthetic bacteria. Unlike bacterial rhodopsins, photosensor proteins composed of seven transmembrane helices and a retinal chromophore in halophilic archaebacteria, PYP is a highly soluble globular protein. The ,/, fold structure of PYP is a structural prototype of the PAS domain superfamily, many members of which function as sensors for various kinds of stimuli. To absorb a photon in the visible region, PYP has a p -coumaric acid chromophore binding to the cysteine residue via a thioester bond. It exists in a deprotonated trans form in the dark. The primary photochemical event is photo-isomerization of the chromophore from trans to cis form. The twisted cis chromophore in early intermediates is relaxed and finally protonated. Consequently, the chromophore becomes electrostatically neutral and rearrangement of the hydrogen-bonding network triggers overall structural change of the protein moiety, in which local conformational change around the chromophore is propagated to the N-terminal region. Thus, it is an ideal model for protein conformational changes that result in functional change, responding to stimuli and expressing physiological activity. In this paper, recent progress in investigation of the photoresponse of PYP is reviewed. [source] In the face of anger: Startle modulation to graded facial expressionsPSYCHOPHYSIOLOGY, Issue 5 2010Jonathan P. Dunning Abstract In the present study, the startle reflex was examined with respect to the degree of anger displayed in facial expressions. To this end, 52 participants viewed faces that were morphed to display 0, 20, 40, 60, 80, or 100% anger. As the percentage of anger in faces increased from 0 to 100%, faces were perceived as increasingly angry; however, relative to neutral facial expressions, startle amplitude was only potentiated to maximally angry faces. These data imply a non-linear relationship between the intensity of angry faces and defensive physiological activity. This pattern of startle modulation suggests a categorical distinction between threatening (100% anger) and other facial expressions presented. These results are further discussed in terms of existing data, and how this paradigm might be utilized in psychopathology research. [source] The effect of antecedent fatiguing activity on the relationship between perceived exertion and physiological activity during a constant load exercise taskPSYCHOPHYSIOLOGY, Issue 5 2007Roger Eston Abstract This study assessed the relationship between the rate of change of the rating of perceived exertion (RPE), physiological activity, and time to volitional exhaustion. After completing a graded exercise test, 10 participants cycled at a constant load equating to 75% of peak oxygen uptake (V, O2peak) to exhaustion. Participants performed two further constant load exercise tests at 75%V, O2peak in a fresh state condition within the next 7 days. The RPE was regressed against time and percentage of the time (%time) to volitional exhaustion in both conditions. Despite a lower respiratory exchange ratio (RER) and higher heart rate at the start of the exercise bout in the fatigued condition, there were no differences in RPE at the onset or completion of exercise. As expected, the rate of increase in RPE was greater in the fatigued condition, but there were no differences when expressed against %time. Results suggest that RPE is set at the start of exercise using a scalar internal timing mechanism, which regulates RPE by altering the gain of the relationship with physiological parameters such as heart rate and RER when these are altered by previous fatiguing exercise. [source] Analysis of derivatized and underivatized theanine enantiomers by high-performance liquid chromatography/atmospheric pressure ionization-mass spectrometryRAPID COMMUNICATIONS IN MASS SPECTROMETRY, Issue 3 2004Meera J. Desai Theanine, a naturally occurring non-proteinic amino acid found in tea leaves, has demonstrated wide-ranging physiological activity, from lowering blood pressure to enhancing the anti-tumor activity of chemotherapeutic drugs. The chiral nature of theanine suggests that enantiospecificity plays a significant role in its various pharmacological functions. Using the Chirobiotic T (teicoplanin) chiral stationary phase, native and derivatized theanine enantiomers were separated and detected via high-performance liquid chromatography (HPLC) coupled to atmospheric pressure ionization mass spectrometry (API-MS). With the use of flow rates compatible with each ionization source, native theanine standards achieved excellent sensitivity and detection limits (10,ng/mL) for both atmospheric pressure chemical ionization (APCI) and electrospray ionization (ESI). Optimum sensitivity and detection limits for derivatized theanine standards were achieved using ESI-MS. The enantiomeric composition of six commercially available L -theanine samples was evaluated using the high-flow APCI-MS method and confirmed with photodiode array detection. Five of the six products contained significant amounts of D -theanine. Only one product, SunTheanine®, appeared to contain only the L -theanine enantiomer. Copyright © 2004 John Wiley & Sons, Ltd. [source] Plasmid DNA electrotransfer for intracellular and secreted proteins expression: new methodological developments and applicationsTHE JOURNAL OF GENE MEDICINE, Issue S1 2004Carole Bloquel Abstract In vivo electrotransfer is a physical method of gene delivery in various tissues and organs, relying on the injection of a plasmid DNA followed by electric pulse delivery. The importance of the association between cell permeabilization and DNA electrophoresis for electrotransfer efficiency has been highlighted. In vivo electrotransfer is of special interest since it is the most efficient non-viral strategy of gene delivery and also because of its low cost, easiness of realization and safety. The potentiality of this technique can be further improved by optimizing plasmid biodistribution in the targeted organ, plasmid structure, and the design of the encoded protein. In particular, we found that plasmids of smaller size were electrotransferred more efficiently than large plasmids. It is also of importance to study and understand kinetic expression of the transgene, which can be very variable, depending on many factors including cellular localization of the protein, physiological activity and regulation. The most widely targeted tissue is skeletal muscle, because this strategy is not only promising for the treatment of muscle disorders, but also for the systemic secretion of therapeutic proteins. Vaccination and oncology gene therapy are also major fields of application of electrotransfer, whereas application to other organs such as liver, brain and cornea are expanding. Many published studies have shown that plasmid electrotransfer can lead to long-lasting therapeutic effects in various pathologies such as cancer, blood disorders, rheumatoid arthritis or muscle ischemia. DNA electrotransfer is also a powerful laboratory tool to study gene function in a given tissue. Copyright © 2004 John Wiley & Sons, Ltd. [source] Pharmacological and Functional Characterization of Novel EP and DP Receptor Agonists: DP1 Receptor Mediates Penile Erection in Multiple SpeciesTHE JOURNAL OF SEXUAL MEDICINE, Issue 2 2008Nadia Brugger PhD ABSTRACT Introduction., Despite the widespread use of prostaglandin E1 as an efficacious treatment for male erectile dysfunction for more than two decades, research on prostanoid function in penile physiology has been limited. Aim., To characterize the pharmacological and physiological activity of novel subtype-selective EP and DP receptor agonists. Methods., Radioligand binding and second messenger assays were used to define receptor subtype specificity of the EP and DP agonists. Functional activity was further characterized using isolated human and rabbit penile cavernosal tissue in organ baths. In vivo activity was assessed in rabbits and rats by measuring changes in cavernous pressure after intracavernosal injection of receptor agonists. Main Outcome Measures., Receptor binding and signal transduction, smooth muscle contractile activity, erectile function. Results., In organ bath preparations of human cavernosal tissue contracted with phenylephrine, EP2- and EP4-selective agonists exhibited variable potency in causing relaxation. One of the compounds caused mild contraction, and none of the compounds was as effective as PGE1 (EC50 = 0.23 µM). There was no consistent correlation between the pharmacological profile (receptor binding and second messenger assays) of the EP agonists and their effect on cavernosal tissue tone. In contrast, the DP1-selective agonist AS702224 (EC50 =29 nM) was more effective in relaxing human cavernosal tissue than either PGE1, PGD2 (EC50 = 58 nM), or the DP agonist BW245C (EC50 =59 nM). In rabbit cavernosal tissue, PGE1 and PGD2 caused only contraction, while AS702224 and BW245C caused relaxation. Intracavernosal administration of AS702224 and BW245C also caused penile tumescence in rabbits and rats. For each compound, the erectile response improved with increasing dose and was significantly higher than vehicle alone. Conclusions., These data suggest that AS702224 is a potent DP1-selective agonist that causes penile erection. The DP1 receptor mediates relaxation in human cavernosal tissue, and stimulates pro-erectile responses in rat and rabbit. Thus, rabbits and rats can be useful models for investigating the physiological function of DP1 receptors. Brugger N, Kim NN, Araldi GL, Traish AM, and Palmer SS. Pharmacological and functional characterization of novel EP and DP receptor agonists: DP1 receptor mediates penile erection in multiple species. J Sex Med 2008;5:344,356. [source] AtKC1, a conditionally targeted Shaker-type subunit, regulates the activity of plant K+ channelsTHE PLANT JOURNAL, Issue 1 2008Geoffrey Duby Summary Amongst the nine voltage-gated K+ channel (Kv) subunits expressed in Arabidopsis, AtKC1 does not seem to form functional Kv channels on its own, and is therefore said to be silent. It has been proposed to be a regulatory subunit, and to significantly influence the functional properties of heteromeric channels in which it participates, along with other Kv channel subunits. The mechanisms underlying these properties of AtKC1 remain unknown. Here, the transient (co-)expression of AtKC1, AKT1 and/or KAT1 genes was obtained in tobacco mesophyll protoplasts, which lack endogenous inward Kv channel activity. Our experimental conditions allowed both localization of expressed polypeptides (GFP-tagging) and recording of heterologously expressed Kv channel activity (untagged polypeptides). It is shown that AtKC1 remains in the endoplasmic reticulum unless it is co-expressed with AKT1. In these conditions heteromeric AtKC1-AKT1 channels are obtained, and display functional properties different from those of homomeric AKT1 channels in the same context. In particular, the activation threshold voltage of the former channels is more negative than that of the latter ones. Also, it is proposed that AtKC1-AKT1 heterodimers are preferred to AKT1-AKT1 homodimers during the process of tetramer assembly. Similar results are obtained upon co-expression of AtKC1 with KAT1. The whole set of data provides evidence that AtKC1 is a conditionally-targeted Kv subunit, which probably downregulates the physiological activity of other Kv channel subunits in Arabidopsis. [source] Effects on Lipid Peroxidation and Antioxidative Enzymes of Euonymus alatus in Cultured Rat HepatocytesBASIC AND CLINICAL PHARMACOLOGY & TOXICOLOGY, Issue 1 2009Kyung-Woon Kim In this paper, we investigate the effects of E. alatus on cultured hepatocyte cell system and lipid peroxidation in hydrogen peroxide (H2O2) treatment conditions. The study covers the physiological activity (the antioxidative activity and the nitrite-scavenging effect) of E. alatus. H2O2 that can produce intracellular free radical was used for inducer of the peroxidation of cellular lipids. Treatment of E. alatus attenuated in cell killing enhanced by increasing concentrations of H2O2. The increased malondialdehyde level induced by H2O2 treatment was reduced by pre-treatment of E. alatus. Furthermore, addition of E. alatus in cell culture medium significantly reduced cell killing and content of intracellular antioxidants. Changes in nitrite-scavenging effect of E. alatus at various concentrations (5,25 mg/ml) and various pH levels (pH 1.2, 4.2 and 6.0) were also observed. The present study was also done to investigate the effects of E. alatus on cultured hepatocyte cell system, H2O2 -induced cytotoxicity and antioxidative enzyme activities, including catalase, superoxide dismutase, glutathione peroxidase and glutathione S-transferase in H2O2 treatment conditions. E. alatus treatment had significant protective or elevating activities on these antioxidative enzyme activities compared to a normal group. The results indicate that E. alatus provides a strong antioxidant protection of cells against H2O2 -induced oxidative stress. [source] Phospholipid profile of rat testis, its unique high level of monolysocardiolipin and its lipolytic capabilities in vitro.CELL BIOCHEMISTRY AND FUNCTION, Issue 4 2008A chromatographic analysis Abstract The phospholipid profiles of testes and heart of 1-, 3-, and 6-month-old rats and their in vitro response to the endogenous phospholipases at pH 7.4 and 38°C for 60,min were analyzed by TLC technology and densitometry. A noticeable high level of monolysocardiolipin (MLCL) was shown in rat testes of all samples analyzed (1-, 3-, and 6-month-old), both control and incubated. In contrast, rat heart control samples revealed a high level of CL and no MLCL was detected. MLCL was only produced subsequent to in vitro incubation of whole tissue homogenate at pH 7.4 and 38°C for 60,min, with concurrent reduction of CL. Alkenyl phosphatidyl ethanolamine (PE) was the major plasmalogen of rat testes. Following in vitro incubation, (a) a very low level of lyso PE plasmalogen was produced only in 3- and 6-month-old rat testes, (b) ceramide was also produced in all testes analyzed with concurrent reduction of sphingomyelin indicating the action of sphingomyelinase. These data clearly illustrate, for the first time, the presence of high levels of MLCL in all rat testes studied which probably is related to the physiological activity in vivo and requires further investigation. Copyright © 2008 John Wiley & Sons, Ltd. [source] | ||||||||||||||||