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Sample records for auratus potential mechanisms

  1. Mechanisms explaining nursery habitat association: how do juvenile snapper (Chrysophrys auratus) benefit from their nursery habitat?

    Science.gov (United States)

    Parsons, Darren M; Middleton, Crispin; Spong, Keren T; Mackay, Graeme; Smith, Matt D; Buckthought, Dane

    2015-01-01

    Nursery habitats provide elevated survival and growth to the organisms that associate with them, and as such are a crucial early life-stage component for many fishes and invertebrates. The exact mechanisms by which these benefits are afforded to associated organisms, however, are often unclear. Here we assessed potential explanations of the nursery function of structurally complex habitats for post-settlement snapper, Chrysophrys auratus, in New Zealand. Specifically, we deployed Artificial Seagrass Units (ASUs) and used a combination of video observation, netting and diet analysis of associated post-settlement snapper as well describing potential prey within the micro-habitats surrounding ASUs. We did not observe any predation attempts and few potential predators, suggesting that for snapper the nursery value of structurally complex habitats is not as a predation refuge. The diet of post-settlement snapper mostly consisted of calanoid and cyclopoid copepods, which were most commonly sampled from within the water column. Nearly all suspected feeding events were also observed within the water column. When considering the velocity of water flow at each ASU, plankton sampling revealed a greater availability of copepods with increasing current strength, while netting and video observation demonstrated that the abundance of snapper was highest at sites with intermediate water velocity. This study highlights that the interaction between water flow and food availability may represent an important trade-off between energy expenditure and food intake for post-settlement snapper. Structurally complex habitats may mediate this relationship, allowing snapper to access sites with higher food availability while reducing swimming costs. This mechanism may have broader relevance, potentially explaining the importance of estuarine nursery habitats for other species.

  2. Mechanisms explaining nursery habitat association: how do juvenile snapper (Chrysophrys auratus benefit from their nursery habitat?

    Directory of Open Access Journals (Sweden)

    Darren M Parsons

    Full Text Available Nursery habitats provide elevated survival and growth to the organisms that associate with them, and as such are a crucial early life-stage component for many fishes and invertebrates. The exact mechanisms by which these benefits are afforded to associated organisms, however, are often unclear. Here we assessed potential explanations of the nursery function of structurally complex habitats for post-settlement snapper, Chrysophrys auratus, in New Zealand. Specifically, we deployed Artificial Seagrass Units (ASUs and used a combination of video observation, netting and diet analysis of associated post-settlement snapper as well describing potential prey within the micro-habitats surrounding ASUs. We did not observe any predation attempts and few potential predators, suggesting that for snapper the nursery value of structurally complex habitats is not as a predation refuge. The diet of post-settlement snapper mostly consisted of calanoid and cyclopoid copepods, which were most commonly sampled from within the water column. Nearly all suspected feeding events were also observed within the water column. When considering the velocity of water flow at each ASU, plankton sampling revealed a greater availability of copepods with increasing current strength, while netting and video observation demonstrated that the abundance of snapper was highest at sites with intermediate water velocity. This study highlights that the interaction between water flow and food availability may represent an important trade-off between energy expenditure and food intake for post-settlement snapper. Structurally complex habitats may mediate this relationship, allowing snapper to access sites with higher food availability while reducing swimming costs. This mechanism may have broader relevance, potentially explaining the importance of estuarine nursery habitats for other species.

  3. PTHrP potentiating estradiol-induced vitellogenesis in sea bream (Sparus auratus, L.)

    NARCIS (Netherlands)

    Bevelander, G.S.; Hang, X.; Abbink, W.; Spanings, F.A.T.; Canario, A.V.; Flik, G.

    2006-01-01

    In fish, vitellogenin is an important nutritional precursor protein produced solely in the liver and released into the blood where it binds calcium. In the gilthead sea bream (Sparus auratus) 17beta-Estradiol (E2) plays an important role in the synthesis of vitellogenin, but also the pituitary

  4. Probiotic potential of Bacillus velezensis JW: Antimicrobial activity against fish pathogenic bacteria and immune enhancement effects on Carassius auratus.

    Science.gov (United States)

    Yi, Yanglei; Zhang, Zhenhua; Zhao, Fan; Liu, Huan; Yu, Lijun; Zha, Jiwei; Wang, Gaoxue

    2018-04-24

    This study evaluated the probiotic potential of B. velezensis JW through experimental and genomic analysis approaches. Strain JW showed antimicrobial activity against a broad range of fish pathogenic bacteria including Aeromonas hydrophila, Aeromonas salmonicida, Lactococcus garvieae, Streptococcus agalactiae, and Vibrio Parahemolyticus. Fish (Carassius auratus) were fed with the diets containing 0 (control), 10 7 , and 10 9  cfu/g of B. velezensis JW for 4 weeks. Various immune parameters were examined at 1, 2, 3, and 4 weeks of post-feeding. Results showed that JW supplemented diets significantly increased acid phosphatase (ACP), alkaline phosphatase (AKP), and glutathione peroxidase (GSH-PX) activity. The mRNA expression of immune-related genes in the head kidney of C. auratus was measured. Among them, the interferon gamma gene (IFN- γ) and tumor necrosis factor-α (TNF-α) showed higher expression after 3 and 4 weeks of feeding (P velezensis JW has the potential to be developed as a probiotic agent in aquaculture. Copyright © 2018. Published by Elsevier Ltd.

  5. Perception of scent over-marks by golden hamsters (Mesocricetus auratus): novel mechanisms for determining which individual's mark is on top.

    Science.gov (United States)

    Johnston, R E; Bhorade, A

    1998-09-01

    Hamsters preferentially remember or value the top scent of a scent over-mark. What cues do they use to do this? Using habituation-discrimination techniques, we exposed male golden hamsters (Mesocricetus auratus) on 3 to 4 trials to genital over-marks from 2 females and then tested subjects for their familiarity with these 2 scents compared with that of a novel female's secretion. Preferential memory for 1 of the 2 individuals' scents did not occur if the 2 marks did not overlap or did not overlap but differed in age, but it did occur if a region of overlap existed or 1 mark apparently occluded another (but did not overlap it). Thus, hamsters use regions of overlap and the spatial configuration of scents to evaluate over-marks. These phenomena constitute evidence for previously unsuspected perceptual abilities, including olfactory scene analysis, which is analogous to visual and auditory scene analysis.

  6. Singular potentials in quantum mechanics

    Energy Technology Data Exchange (ETDEWEB)

    Aguilera-Navarro, V.C. [Instituto de Fisica Teorica (IFT), Sao Paulo, SP (Brazil); Koo, E. Ley [Universidad Nacional Autonoma de Mexico, Mexico City (Mexico). Inst. de Fisica

    1995-10-01

    This paper is a review of some mathematical methods as recently developed and applied to deal with singular potentials in Quantum Mechanics. Regular and singular perturbative methods as well as variational treatments are considered. (author). 25 refs.

  7. Thyroid function and cold acclimation in the hamster, Mesocricetus auratus

    International Nuclear Information System (INIS)

    Tomasi, T.E.; Horwitz, B.A.

    1987-01-01

    Basal metabolic rate (BMR), thyroxine utilization rate (T 4 U), and triiodothyronine utilization rate (T 3 U) were measured in cold-acclimated (CA) and room temperature-acclimated (RA) male golden hamsters, Mesocricetus auratus. Hormone utilization rates were calculated via the plasma disappearance technique using 125 I-labeled hormones and measuring serum hormone levels via radioimmunoassay. BMR showed a significant 28% increase with cold acclimation. The same cold exposure also produced a 32% increase in T 4 U, and a 204% increase in T 3 U. The much greater increase in T 3 U implies that previous assessments of the relationship between cold acclimation and thyroid function may have been underestimated and that cold exposure induces both quantitative and qualitative changes in thyroid function. It is concluded that in the cold-acclimated state, T 3 U more accurately reflects thyroid function than does T 4 U. A mechanism for the cold-induced change in BMR is proposed

  8. Kin discrimination in cannibalistic tadpoles of the Green Poison Frog, Dendrobates auratus (Anura, Dendrobatidae)

    OpenAIRE

    Heather M. Gray; Kyle Summers; Roberto Ibáñez D.

    2009-01-01

    Cannibalizing a related individual can reduce the inclusive fitness of the cannibal. Hence, mechanisms that allow a tadpole to recognize and modify its behavior toward kin may reduce the inclusive fitness costs of cannibalism. Alternatively, ecological factors may cause preferential treatment of kin to be too costly to be favored by selection. We tested these two predictions in the Green Poison Frog, Dendrobates auratus. The effect of kinship on larval cannibalism was examined through a serie...

  9. Kin discrimination in cannibalistic tadpoles of the Green Poison Frog, Dendrobates auratus (Anura, Dendrobatidae

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    Heather M. Gray

    2009-07-01

    Full Text Available Cannibalizing a related individual can reduce the inclusive fitness of the cannibal. Hence, mechanisms that allow a tadpole to recognize and modify its behavior toward kin may reduce the inclusive fitness costs of cannibalism. Alternatively, ecological factors may cause preferential treatment of kin to be too costly to be favored by selection. We tested these two predictions in the Green Poison Frog, Dendrobates auratus. The effect of kinship on larval cannibalism was examined through a series of kin-discrimination trials. The behavior of large tadpoles was observed when presented with two small, tethered tadpoles, one a clutchmate and one an unrelated tadpole. In these simultaneous presentation tests, tadpoles displayed a significant preference for attacking kin. In a series of timed trials, pairs of unequally sized tadpoles were placed together in containers. The majority (70% of large tadpoles took less than24 hr to consume the small tadpole. Kinship did not affect the survival time of the small tadpole. Our results are consistent with observations that D. auratus is an indiscriminate predator. As conspecifics may be serious competitors, their swift elimination would be an advantage, particularly in the small, nutrient-poor poolsused by this species.

  10. Quantum mechanical streamlines. I - Square potential barrier

    Science.gov (United States)

    Hirschfelder, J. O.; Christoph, A. C.; Palke, W. E.

    1974-01-01

    Exact numerical calculations are made for scattering of quantum mechanical particles hitting a square two-dimensional potential barrier (an exact analog of the Goos-Haenchen optical experiments). Quantum mechanical streamlines are plotted and found to be smooth and continuous, to have continuous first derivatives even through the classical forbidden region, and to form quantized vortices around each of the nodal points. A comparison is made between the present numerical calculations and the stationary wave approximation, and good agreement is found between both the Goos-Haenchen shifts and the reflection coefficients. The time-independent Schroedinger equation for real wavefunctions is reduced to solving a nonlinear first-order partial differential equation, leading to a generalization of the Prager-Hirschfelder perturbation scheme. Implications of the hydrodynamical formulation of quantum mechanics are discussed, and cases are cited where quantum and classical mechanical motions are identical.

  11. Radioecological studies of {sup 137}Cs in limnological ecosystems. Accumulation and excretion of {sup 137}Cs in goldfish, Carassius auratus auratus, from diets

    Energy Technology Data Exchange (ETDEWEB)

    Miyake, Sadaaki; Motegi, Misako; Oosawa, Takashi; Nakazawa, Kiyoaki [Saitama Inst. of Public Health, Urawa (Japan); Ogata, Hiromitsu; Izumo, Yoshiro; Nakamura, Fumio

    1996-06-01

    Accumulation and excretion Of {sup 137}Cs in goldfish, Carassius auratus auratus, from radioactive diets (killifish, Oryzias latipes, meats accumulated {sup 137}Cs in the radioactive freshwater) or control diets (killifish meats mixed {sup 137}CsCl) were investigated in order to elucidate the accumulation mechanism of the radionuclide in natural living fishes. The accumulation of {sup 137}Cs, expressed in concentration ratio, in whole body of the fish showed a increasing tendency in proportion to the rearing time. On the other hand, the excretion of {sup 137}Cs, expressed in retention rate, in whole body rearing by administration of non-radioactive commercial diets after the accumulation above for 7 days, demonstrated a rapid decreasing at first few days, and followed a gradual decreasing tendency (the biological half lives were about 1.5 days and 52 days, respectively). As for the tissues and organs, higher accumulation and higher excretion were found in the viscera than those in the muscle. It is so suggested that the metabolic turnover rate of this radionuclide for the viscera is more rapid than that for the muscle. From the experimental results, it was confirmed that the relative contribution by ingestion of the radioactive diets in the accumulation of {sup 137}Cs in natural environmental fish was comparatively higher in comparison with uptake of the radionuclide in the radioactive freshwater. With regard to the difference between the radioactive diets and the control diets, the accumulation of {sup 137}Cs in whole body of the fish from the radioactive diets was less than that from the control diets to rearing 5 days, but afterward was not different. The difference of the accumulation between these diets will be attributable to that of the metabolic turnover between these diets. (author)

  12. Growth Responses and Survival of the Goldfish, Carassius auratus ...

    African Journals Online (AJOL)

    Five sets of 20-day old goldfish fry, Carassius auratus with average weights of 0.167 ± 0.003 g were reared for eight weeks in plastic bowls for growth and survival studies. One set (labelled MN) was fed Moina and Cyclops. A second set (labelled FM) was fed fishmeal, and a third set (labelled AF) was fed a 45% protein ...

  13. Zinc diethyldithiocarbamate allergenicity: potential haptenation mechanisms.

    Science.gov (United States)

    Chipinda, Itai; Hettick, Justin M; Simoyi, Reuben H; Siegel, Paul D

    2008-08-01

    Zinc diethyldithiocarbamate (ZDEC) and its disulfide, tetraethylthiuram disulfide (TETD), are rubber accelerators and contact allergens that cross-react in some individuals. This study explored potential protein haptenation mechanisms of ZDEC and its oxidation products. ZDEC oxidation/reduction products and sites of protein binding were assessed using high-performance liquid chromatography and mass spectrometry. The murine local lymph node assay (LLNA) was employed to probe haptenation mechanisms of ZDEC by examining its allergenicity along with its oxidation products and through elimination of oxidation and chelation mechanisms by substituting cobalt for zinc [cobalt (II) dithiocarbamate, CoDEC]. Oxidation of ZDEC by hypochlorous acid (bleach, HOCl), iodine, or hydrogen peroxide resulted in production of TETD, tetraethylthiocarbamoyl disulfide, and tetraethyldicarbamoyl disulfide (TEDCD). Albumin thiols reduced TETD with subsequent mixed disulfide formation/haptenation. ZDEC directly chelated the copper ion on the active site of the superoxide dismutase, whereas CoDEC did not bind to Cu proteins or form mixed disulfides with free thiols. ZDEC, sodium diethyldithiocarbamate, TEDCD, and TETD were all positive in the LLNA except CoDEC, which was non-allergenic. The thiol is the critical functional group in ZDEC's allergenicity, and haptenation is predominantly through chelation of metalloproteins and formation of mixed disulfides.

  14. BIOCHEMICAL AND HISTOLOGICAL EFFECTS OF DELTAMETHRIN EXPOSURE ON THE GILLS OF CARASSIUS AURATUS GIBELIO (Pisces Cyprinidae

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    DIANA COSTIN

    2007-05-01

    Full Text Available This study investigated the alterations in the activities of several antioxidant enzymes inthe gills of the freshwater fish Carassius auratus gibelio exposed to deltamethrin. To getthis goal, groups of 10 individuals were exposed for one, two, three, seven and fourteendays to sublethal concentration of deltamethrin (2 µg/L. Another group was used ascontrol. The activities of catalase, gluthatione peroxidase and gluthatione reductasewere significantly decreased, while the glutathione-S-transferase was up-regulated. Allfish, exposed to 2 µg/L deltamethrin revealed gills morphological alterations after 48h ofexposure which were accentuated after 14 days. In the gills hyperemia, fusion ofsecondary lamellae, epithelial layer rupture and chloride cells proliferation wereobserved. These results suggest that an immediate adaptive response to the oxidativestress appeared, demonstrating alterations in the antoxidant defense mechanism in thegills of deltamethrin intoxicated fish.

  15. BIOCHEMICAL AND HISTOLOGICAL EFFECTS OF DELTAMETHRIN EXPOSURE ON THE GILLS OF CARASSIUS AURATUS GIBELIO (Pisces Cyprinidae

    Directory of Open Access Journals (Sweden)

    COSTIN DIANA

    2007-01-01

    Full Text Available This study investigated the alterations in the activities of several antioxidant enzymesin the gills of the freshwater fish Carassius auratus gibelio exposed to deltamethrin.To get this goal, groups of 10 individuals were exposed for one, two, three, sevenand fourteen days to sublethal concentration of deltamethrin (2 g/L. Anothergroup was used as control. The activities of catalase, gluthatione peroxidase andgluthatione reductase were significantly decreased, while the glutathione-Stransferasewas up-regulated. All fish, exposed to 2glL deltamethrin revealed gillsmorphological alterations after 48h of exposure which were accentuated after 14days. In the gills hyperemia, fusion of secondary lamellae, epithelial layer ruptureand chloride cells proliferation were observed. These results suggest that animmediate adaptive response to the oxidative stress appeared, demonstratingalterations in the antoxidant defense mechanism in the gills of deltamethrinintoxicated fish.

  16. Hepatic oxidative stress biomarker responses in freshwater fish Carassius auratus exposed to four benzophenone UV filters.

    Science.gov (United States)

    Liu, Hui; Sun, Ping; Liu, Hongxia; Yang, Shaogui; Wang, Liansheng; Wang, Zunyao

    2015-09-01

    Benzophenone (BP) type UV filters are widely used in many personal care products to protect human from UV irradiation. Despite the estrogenic potencies to fish and the environmental occurrences of BP derivatives in aquatic systems, little information is available regarding their effects on the antioxidant defense system in fish. In this work, the oxidative stress induced in livers of Carassius auratus was assessed using four biomarkers. The integrated biomarker response (IBR) was applied to assess the overall antioxidant status in fish. Moreover, liver tissues were also studied histologically. The changes in the activities of antioxidant enzymes and glutathione levels suggested that BPs generates oxidative stress in fish. The IBR index revealed that the hepatic oxidative toxicity followed the order BP-1>BP-2>BP-4>BP-3. The histopathological analysis revealed lesions caused by BPs. This investigation provides essential information for assessing the potential ecological risk of BP-type UV filters. Copyright © 2015 Elsevier Inc. All rights reserved.

  17. NMR-based metabolomics approach to study the toxicity of lambda-cyhalothrin to goldfish (Carassius auratus)

    Energy Technology Data Exchange (ETDEWEB)

    Li, Minghui [State Key Laboratory of Natural Medicines, Department of Natural Medicinal Chemistry, China Pharmaceutical University, 24 Tong Jia Xiang, Nanjing 210009 (China); Wang, Junsong, E-mail: wang.junsong@gmail.com [Center for Molecular Metabolism, School of Environmental and Biological Engineering, Nanjing University of Science and Technology, 200 Xiao Ling Wei Street, Nanjing 210094 (China); Lu, Zhaoguang; Wei, Dandan; Yang, Minghua [State Key Laboratory of Natural Medicines, Department of Natural Medicinal Chemistry, China Pharmaceutical University, 24 Tong Jia Xiang, Nanjing 210009 (China); Kong, Lingyi, E-mail: cpu_lykong@126.com [State Key Laboratory of Natural Medicines, Department of Natural Medicinal Chemistry, China Pharmaceutical University, 24 Tong Jia Xiang, Nanjing 210009 (China)

    2014-01-15

    Highlights: •A goldfish model was established to investigate the toxicity of lambda-cyhalothrin (LCT) exposure on multiple organs. •NMR based metabolomics approach were firstly used to provide a global view of the toxicity of LCT. •LCT induced neurotransmitters and osmoregulatory imbalances, oxidative stress, energy and amino acid metabolic disorders. •Glutamate–glutamine–GABA axis as a potential target for LCT toxicity was first found. -- Abstract: In this study, a {sup 1}H nuclear magnetic resonance (NMR) based metabolomics approach was applied to investigate the toxicity of lambda-cyhalothrin (LCT) in goldfish (Carassius auratus). LCT showed tissue-specific damage to gill, heart, liver and kidney tissues of goldfish. NMR profiling combined with statistical methods such as orthogonal partial least squares discriminant analysis (OPLS-DA) and two-dimensional statistical total correlation spectroscopy (2D-STOCSY) was developed to discern metabolite changes occurring after one week LCT exposure in brain, heart and kidney tissues of goldfish. LCT exposure influenced levels of many metabolites (e.g., leucine, isoleucine and valine in brain and kidney; lactate in brain, heart and kidney; alanine in brain and kidney; choline in brain, heart and kidney; taurine in brain, heart and kidney; N-acetylaspartate in brain; myo-inositol in brain; phosphocreatine in brain and heart; 2-oxoglutarate in brain; cis-aconitate in brain, and etc.), and broke the balance of neurotransmitters and osmoregulators, evoked oxidative stress, disturbed metabolisms of energy and amino acids. The implication of glutamate–glutamine–gamma-aminobutyric axis in LCT induced toxicity was demonstrated for the first time. Our findings demonstrated the applicability and potential of metabolomics approach for the elucidation of toxicological effects of pesticides and the underlying mechanisms, and the discovery of biomarkers for pesticide pollution in aquatic environment.

  18. Hierarchical structure and cytocompatibility of fish scales from Carassius auratus

    International Nuclear Information System (INIS)

    Fang, Zhou; Wang, Yukun; Feng, Qingling; Kienzle, Arne; Müller, Werner E.G.

    2014-01-01

    To study the structure and the cytocompatibility of fish scales from Carassius auratus, scanning electron microscopy (SEM) was used to observe the morphology of fish scales treated with different processing methods. Based on varying morphologies and components, the fish scales can be divided into three regions on the surface and three layers in vertical. The functions of these three individual layers were analyzed. SEM results show that the primary inorganic components are spherical or cubic hydroxyapatite (HA) nanoparticles. The fish scales have an ∼ 60° overlapped plywood structure of lamellas in the fibrillary plate. The plywood structure consists of co-aligned type I collagen fibers, which are parallel to the HA lamellas. X-ray diffraction (XRD), thermogravimetric analysis/differential scanning calorimetry (TGA/DSC) and Fourier transform infrared (FTIR) analysis indicate that the main components are HA and type I collagen fibers. MC3T3-E1 cell culture results show a high cytocompatibility and the ability to guide cell proliferation and migration along the scale ridge channels of the fish scales. This plywood structure provides inspiration for a structure-enhanced composite material. - Highlights: • The Carassius auratus fish scale can be divided into 3 layers rather than 2. • The functions of these three individual layers were firstly analyzed. • The fish scale shows a high cytocompatibility. • The fish scale can guide cells migration along the scale ridge channels

  19. The study of the peptide composition of the supernatants from mealworm Tenebrio molitor larvae and goldfish Carassius auratus during cold acclimation

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    А. К. Гулевский

    2016-11-01

    Full Text Available The molecular-mass distribution of peptides from supernatants, obtained from the tissues of larvae Tenebrio molitor and goldfish Carassius auratus during cold acclimation, has been determined by chromatography. The results showed that peptide spectrum of the supernatants from larvae T. molitor and C. auratus varied during cold acclimation. The supernatants from non-acclimated larvae of T. molitor and deacclimated fish possessed the highest number of peptide fractions. Furthermore, the cold-acclimated larvae of T. molitor had the peptide fractions of the low molecular weight (ca. 5.4×102 ÷22.6×102 Da, and non-acclimated insects had the peptides of the high molecular weight (ca. 46.8×102÷66×102 Da. Next, the organ-specific changes of the peptide composition of the goldfish during winter deacclimation have been revealed. Specifically, the low molecular weight peptides (ca. (14.1 ± 0.3×102 and (6.75 ± 0.25×102 Da, have been detected in the C. auratus muscles, and both the high (ca. (67.83 ± 0.21×102 ( ca. 64.16 ± 0.26×102 Da and low (ca. (34.1 ± 1.0×102 and (14.29 ± 0.15×102 Da molecular weight peptides have been detected in the liver. Quantitative and qualitative changes in the peptide spectra from supernatants of the T. molitor and C. auratus during cold acclimation could be one of the mechanisms of their natural adaptation to low temperatures.

  20. Homocysteine, alcoholism and its potential epigenetic mechanism

    Science.gov (United States)

    Kamat, Pradip K.; Mallonee, Carissa J.; George, Akash K.; Tyagi, Suresh C.; Tyagi, Neetu

    2016-01-01

    Alcohol is the most socially accepted addictive drug. Alcohol consumption is associated with some health problems such as neurological, cognitive, behavioral deficits, cancer, heart and liver disease. Mechanisms of alcohol-induced toxicity are presently not yet clear. One of the mechanisms underlying alcohol toxicity has to do with its interaction with amino acid-homocysteine (Hcy), which has been linked with brain neurotoxicity. Elevated homocysteine (Hcy) impairs with various physiological mechanisms in the body, especially metabolic pathways. Hcy metabolism is predominantly controlled by epigenetic regulation such as DNA methylation, histone modifications, and acetylation. An alteration in these processes leads to epigenetic modification. Therefore, in this review, we summarize the role of Hcy metabolism abnormalities in alcohol-induced toxicity with epigenetic adaptation and their influences on cerebrovascular pathology. PMID:27805256

  1. A multi-biomarker assessment of single and combined effects of norfloxacin and sulfamethoxazole on male goldfish (Carassius auratus).

    Science.gov (United States)

    Liu, Jianchao; Lu, Guanghua; Wu, Donghai; Yan, Zhenhua

    2014-04-01

    In the present study, the sublethal effects of norfloxacin alone and in combination with sulfamethoxazole in goldfish (Carassius auratus) were investigated, the biomarkers including acetylcholinesterase (AChE) in brain, 7-ethoxyresorufin O-deethylase (EROD), glutathione S-transferase (GST), and superoxides dismutase (SOD) activities in liver, vitellogenin (Vtg) in serum and DNA damage in gonad were determined after 1, 2, 4 and 7 days of exposure. Brain AChE activity was significantly inhibited by norfloxacin (≥0.4 mg/L) after 4 and 7 days and the mixtures with sulfamethoxazole (≥0.24 mg/L) after 4 days of exposure, and significant concentration-response relationships were obtained. Liver EROD, GST and SOD activities were significantly increased by the individual and mixed pharmaceuticals in most cases and exhibited analogously bell-shaped concentration-response curves. Serum Vtg was increased by the highest concentration of norfloxacin and two higher concentrations of the mixtures. Higher concentrations of the test antibiotics induced significant DNA damage in a concentration- and time-dependent manner. The results indicated that selected antibiotics possesses cytotoxic and genotoxic potential against the non-target organism C. auratus. Copyright © 2014 Elsevier Inc. All rights reserved.

  2. Potential Mechanisms of Exercise in Gestational Diabetes

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    Saeid Golbidi

    2013-01-01

    Full Text Available Gestational diabetes mellitus (GDM is defined as glucose intolerance first diagnosed during pregnancy. This condition shares same array of underlying abnormalities as occurs in diabetes outside of pregnancy, for example, genetic and environmental causes. However, the role of a sedentary lifestyle and/or excess energy intake is more prominent in GDM. Physically active women are less likely to develop GDM and other pregnancy-related diseases. Weight gain in pregnancy causes increased release of adipokines from adipose tissue; many adipokines increase oxidative stress and insulin resistance. Increased intramyocellular lipids also increase cellular oxidative stress with subsequent generation of reactive oxygen species. A well-planned program of exercise is an important component of a healthy lifestyle and, in spite of old myths, is also recommended during pregnancy. This paper briefly reviews the role of adipokines in gestational diabetes and attempts to shed some light on the mechanisms by which exercise can be beneficial as an adjuvant therapy in GDM. In this regard, we discuss the mechanisms by which exercise increases insulin sensitivity, changes adipokine profile levels, and boosts antioxidant mechanisms.

  3. Estudios inmunologicos en hamsters (Cricetus auratus infectados con Schistosoma mansoni

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    Eduardo Monge

    1986-08-01

    Full Text Available Los resultados de este trabajo muestran que el hamster (Cricetus auratus puede ser utilizado como un modelo experimental para estudios inmunológicos en la infección por Schistosoma mansoni. Los datos obtenidos, relativos a inmunidad concomitante, producción de anticuerpo letal e inmunosupresión se asemejan a los conseguidos en otros modelos experimentales ya establecidos. Estas observaciones indican que el hámster, además de ser un hospedero satisfactorio para el mantenimiento del parásito en el laboratorio, puede ser considerado como un modelo experimental alterno cuyo crecimiento y mantenimiento son relativamente simples y además es un animal de fácil manejo.

  4. BIOCHEMISTRY PANEL REFERENCE INTERVALS FOR JUVENILE GOLDFISH (CARASSIUS AURATUS).

    Science.gov (United States)

    Adamovicz, Laura A; Trosclair, Macy R; Lewbart, Gregory A

    2017-09-01

    Reference intervals for diagnostic tests are vitally important for clinical decision making. Despite the popularity of pet goldfish (Carassius auratus), reference intervals have not been generated for routine biochemistry panel analytes in this species. This study establishes de novo reference intervals for packed cell volume and total solids, using 47 apparently healthy immature goldfish, and for 11 common chemistry panel analytes (albumin, aspartate aminotransferase, calcium, creatine kinase, globulin, blood glucose, sodium, potassium, phosphorous, total protein, and uric acid) using 39 immature goldfish. Robust reference intervals were generated following recommendations of the American Society for Veterinary Clinical Pathology. Linear regression was used to demonstrate a statistically significant relationship between body weight and calcium, albumin, total protein, potassium, packed cell volume, and total solids. The results of this study serve as a useful baseline for future reference interval generation in goldfish.

  5. Vitamin D and Bone Health; Potential Mechanisms

    Directory of Open Access Journals (Sweden)

    J.J. Strain

    2010-07-01

    Full Text Available Osteoporosis is associated with increased morbidity, mortality and significant economic and health costs. Vitamin D is a secosteriod hormone essential for calcium absorption and bone mineralization which is positively associated with bone mineral density [BMD]. It is well-established that prolonged and severe vitamin D deficiency leads to rickets in children and osteomalacia in adults. Sub-optimal vitamin D status has been reported in many populations but it is a particular concern in older people; thus there is clearly a need for effective strategies to optimise bone health. A number of recent studies have suggested that the role of vitamin D in preventing fractures may be via its mediating effects on muscle function (a defect in muscle function is one of the classical signs of rickets and inflammation. Studies have demonstrated that vitamin D supplementation can improve muscle strength which in turn contributes to a decrease in incidence of falls, one of the largest contributors to fracture incidence. Osteoporosis is often considered to be an inflammatory condition and pro-inflammatory cytokines have been associated with increased bone metabolism. The immunoregulatory mechanisms of vitamin D may thus modulate the effect of these cytokines on bone health and subsequent fracture risk. Vitamin D, therefore, may influence fracture risk via a number of different mechanisms.

  6. Potential degradation mechanisms of stylolitic limestones

    Science.gov (United States)

    Aly, Nevin; Török, Ákos; Aguilar Sanchez, Asel Maria; Wangler, Timothy

    2017-04-01

    Stylolites are irregular rough surfaces formed due to the pressure-solution process and commonly developed in carbonate stones. Stylolite formation is usually accompanied by the accumulation of insoluble residues i.e. organic matter, oxides and clays on the stylolitic surfaces. The amount and the type of these clays may play a significant role in the deterioration of the host stone. This study presents the characterization of various stylolitic limestones containing different amounts of clays and used extensively as building cladding and decorative stones in Israel and in Hungary. The first case study focuses on two lithotypes from Israel, both of them are biocalcirudite-calcarenite with high amount of bioclasts. Abundance of open stylolites filled partially with organic matter and minor amounts of clays exist in the first lithotype with cream colour. The second lithotype has grey colour and contains organic matter and pyrite dispersed throughout the stone and more concentrated within the stylolites along with clay and dolomite crystal. Both lithotypes exhibit signs of decay just after a few years of exposure. The first studied Hungarian limestone is a red Jurassic carbonate (ammonitico rosso type) that was formed in pelagic marine environment. This wackestone contains abundant pelagic microfossils. The limestone has been used from Roman period in Central Europe in Hungary, Romania and Poland. The stylolites are seen as darker bedding parallel seams containing minor amounts of clay and hematite. Small amount of clay is also found in isolated nodules. The second Hungarian lithotype is also a Jurassic limestone which contains less clay than the previous one. This yellowish-white limestone is strongly cemented and contains red intersecting stylolites that do not follow the bedding planes or stratification. The main aim of this study is to understand and evaluate the damage mechanism of different stylolitic limestones. Samples were exposed to multiple thermal and wet

  7. Dyslipidemia in Obesity: Mechanisms and Potential Targets

    Directory of Open Access Journals (Sweden)

    Jan Willem F. Elte

    2013-04-01

    Full Text Available Obesity has become a major worldwide health problem. In every single country in the world, the incidence of obesity is rising continuously and therefore, the associated morbidity, mortality and both medical and economical costs are expected to increase as well. The majority of these complications are related to co-morbid conditions that include coronary artery disease, hypertension, type 2 diabetes mellitus, respiratory disorders and dyslipidemia. Obesity increases cardiovascular risk through risk factors such as increased fasting plasma triglycerides, high LDL cholesterol, low HDL cholesterol, elevated blood glucose and insulin levels and high blood pressure. Novel lipid dependent, metabolic risk factors associated to obesity are the presence of the small dense LDL phenotype, postprandial hyperlipidemia with accumulation of atherogenic remnants and hepatic overproduction of apoB containing lipoproteins. All these lipid abnormalities are typical features of the metabolic syndrome and may be associated to a pro-inflammatory gradient which in part may originate in the adipose tissue itself and directly affect the endothelium. An important link between obesity, the metabolic syndrome and dyslipidemia, seems to be the development of insulin resistance in peripheral tissues leading to an enhanced hepatic flux of fatty acids from dietary sources, intravascular lipolysis and from adipose tissue resistant to the antilipolytic effects of insulin. The current review will focus on these aspects of lipid metabolism in obesity and potential interventions to treat the obesity related dyslipidemia.

  8. Viscoelastic Characteristics of Fins, Muscle and Skin in Crucian Carp (Carassius Auratus) Described by the Fractional Zener Model

    International Nuclear Information System (INIS)

    Chen Ming; Jia Lai-Bing; Yin Xie-Zhen

    2011-01-01

    Fish are supposed to be able to adapt to various underwater environments. The mechanical properties of the body of a fish is of essential importance in order to explore the source of high efficiency during fish swimming. We investigate the viscoelastic properties of the fins, muscle and skin of Crucian carp (carassius auratus). A fractional Zener model is used to fit the relaxation force and the results show that the model can describe the relaxation process well. With a Fourier transform, we discuss the response functions of the fins, muscle and skin of Crucian carp under the external excitation of a harmonic force. Comparison of these results with the cruising frequency of Crucian carp shows that the dissipation due to internal viscoelasticity during cruising is small. (cross-disciplinary physics and related areas of science and technology)

  9. Genetic variation and population history of three Carassius auratus populations in Huaihe River, China.

    Science.gov (United States)

    Chen, Wei; Zhao, Yuanjun; Yang, Chengzhong

    2016-11-01

    In order to investigate the relationships of drainage history of Huaihe River with the genetic history of Carassius auratus along the river, we examined the genetic variations and population histories of three wild C. auratus populations in Huaihe River based on the D-loop gene. The results showed that their nucleotide and haplotype diversities were ranged from 0.00268 to 0.00651 and from 0.863 to 0.902, respectively, and their genetic distance was quite small. The analysis of molecular variance demonstrated that a frequent inter-population connection and large historic gene flows occurred among the three populations. Demographic analysis indicated that expansions had been happened in three populations. After investigating the historic process of the Huaihe River, we presumed that both nature and artificial factors may play important roles in shaping the genetic structure of the three populations. The present study also provided genetic information of C. auratus for further conservation of its germplasm resources.

  10. Development of Taenia pisiformis in golden hamster (Mesocricetus auratus

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    Maravilla Pablo

    2011-07-01

    Full Text Available Abstract The life cycle of Taenia pisiformis includes canines as definitive hosts and rabbits as intermediate hosts. Golden hamster (Mesocricetus auratus is a rodent that has been successfully used as experimental model of Taenia solium taeniosis. In the present study we describe the course of T. pisiformis infection in experimentally infected golden hamsters. Ten females, treated with methyl-prednisolone acetate were infected with three T. pisiformis cysticerci each one excised from one rabbit. Proglottids released in faeces and adults recovered during necropsy showed that all animals were infected. Eggs obtained from the hamsters' tapeworms, were assessed for viability using trypan blue or propidium iodide stains. Afterwards, some rabbits were inoculated with eggs, necropsy was performed after seven weeks and viable cysticerci were obtained. Our results demonstrate that the experimental model of adult Taenia pisiformis in golden hamster can replace the use of canines in order to study this parasite and to provide eggs and adult tapeworms to be used in different types of experiments.

  11. Vitamin A supplementation in diets for Goldfish (Carassius auratus

    Directory of Open Access Journals (Sweden)

    Edionei Maico Fries

    2014-09-01

    Full Text Available Vitamin A is important to the proper development and functioning of the body, appearing in several metabolic functions. This experiment was conducted with aim evaluate to the vitamin A supplementation in diets for Goldfish Carassius auratus. The experimental was completely randomized with six treatments (0, 2.000, 4.000, 8.000, 16.000 and 32.000 IU of vitamin A kg-1 diet with four repetitions into 24 experimental cages, with capacity for 150 liters useful volume, made of mesh shading, installed inside a masonry circular tank with a capacity of 25 m3 of water. 192 fish with an average initial weight of 6.66±0.57 g and initial length of 7.30±0.33 cm, feed at 8h, 11h, 14h and 17h at satiety were used. Evaluated the effects on productive performance and intensity of yellow-red coloring of the skin of the fish were. The Linear Response Plateau analysis of weight gain and length total, feed conversion and daily growth rate versus vitamin A requirement estimate showed 2,624, 2,385 and 2,358, 4,381 and 2,866 IU of vitamin A per kg diet, respectively. The data indicated that this vitamin has little or no influence on the intensity of the skin color of the Goldfish.

  12. Students' Conceptual Difficulties in Quantum Mechanics: Potential Well Problems

    Science.gov (United States)

    Ozcan, Ozgur; Didis, Nilufer; Tasar, Mehmet Fatih

    2009-01-01

    In this study, students' conceptual difficulties about some basic concepts in quantum mechanics like one-dimensional potential well problems and probability density of tunneling particles were identified. For this aim, a multiple choice instrument named Quantum Mechanics Conceptual Test has been developed by one of the researchers of this study…

  13. Exactly Solvable Quantum Mechanical Potentials: An Alternative Approach.

    Science.gov (United States)

    Pronchik, Jeremy N.; Williams, Brian W.

    2003-01-01

    Describes an alternative approach to finding exactly solvable, one-dimensional quantum mechanical potentials. Differs from the usual approach in that instead of starting with a particular potential and seeking solutions to the related Schrodinger equations, it begins with known solutions to second-order ordinary differential equations and seeks to…

  14. Baseline survey of the fish fauna of a highly eutrophic estuary and evidence for its colonisation by Goldfish (Carassius auratus

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    James R. Tweedley

    2017-09-01

    Full Text Available Abstract This study represents the first quantitative survey of the fish fauna of the highly eutrophic Vasse and Wonnerup estuaries, part of the Ramsar-listed Vasse-Wonnerup Wetland System in south-western Australia. Sampling at five sites in each of these estuaries occurred in January 2012 (austral summer to provide a species inventory and determine whether the number of species, total density and fish community composition differed between the two water bodies. A total of 18,148 fish were recorded, representing six species across four families. Three species that can complete their life cycle within estuaries, i.e. the atherinids Lepthatherina wallacei and Atherinosoma elongata and the gobiid Pseudogobius olorum, dominated the fish fauna, accounting for >99% of all fish collected. No significant inter-estuary differences were observed in the mean number of species, mean total density or fish community composition. Although the fish community was depauperate in terms of the number of species, total density was high, reflecting the presence of permanent and seasonal barriers to the immigration of marine species into these estuaries and the highly productive nature of this system, respectively. Two introduced freshwater species, i.e. the Eastern Gambusia Gambusia holbrooki and the Goldfish, Carassius auratus, were recorded in the Vasse Estuary. As C. auratus was found in mesohaline conditions, individuals may be able to use the estuary as a ‘saltbridge’ to gain access to other tributaries and/or the Wonnerup Estuary, and thus expand their distribution. These findings are of concern given the potential deleterious biological and ecological effects of these alien species.

  15. Chlorpheniramine impairs functional recovery in Carassius auratus after telencephalic ablation

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    D.C. Garção

    2009-04-01

    Full Text Available We determined the effect of an H1 receptor antagonist on the functional recovery of Carassius auratus submitted to telencephalic ablation. Five days after surgery the fish underwent a spatial-choice learning paradigm test. The fish, weighing 6-12 g, were divided into four groups: telencephalic ablation (A or sham lesion (S and saline (SAL or chlorpheniramine (CPA, ip, 16 mg/kg. For eight consecutive days each animal was trained individually in sessions separated by 24 h (alternate days. Training trials (T1-T8 consisted of finding the food in one of the feeders, which were randomly blocked for each subject. Animals received an intraperitoneal injection of SAL or CPA 10 min after the training trials. The time spent by the animals in each group to find the food (latency was analyzed separately at T1 and T8 by the Kruskal-Wallis test, followed by the Student Newman-Keuls test. At T1 the latencies (mean ± SEM of the A-SAL (586.3 ± 13.6 and A-CPA (600 ± 0 groups were significantly longer than those of the S-SAL (226.14 ± 61.15 and S-CPA (356.33 ± 68.8 groups. At T8, the latencies of the A-CPA group (510.11 ± 62.2 remained higher than those of the other groups, all of which showed significantly shorter latencies (A-SAL = 301.91 ± 78.32; S-CPA = 191.58 ± 73.03; S-SAL = 90.28 ± 41 compared with T1. These results support evidence that training can lead to functional recovery of spatial-choice learning in telencephalonless fish and also that the antagonist of the H1 receptor impairs it.

  16. The Coulomb potential in quantum mechanics and related topics

    International Nuclear Information System (INIS)

    Haeringen, H. van.

    1978-01-01

    This dissertation consists of an analytic study of the Coulomb interaction in nonrelativistic quantum mechanics and some related topics. The author investigates in a number of self-contained articles various interesting and important properties of the Coulomb potential. Some of these properties are shared by other potentials which also play a role in quantum mechanics. For such related interactions a comparative study is made. The principal difficulties in the description of proton-deuteron scattering and break-up reactions, due to the Coulomb interaction, are studied by working out a simple model. The bound states are studied for the Coulomb plus Yamaguchi potential, for the symmetric shifted Coulomb potential, and for local potentials with an inverse-distance-squared asymptotic behaviour. (Auth.)

  17. 1/N expansion for invariant potentials in quantum mechanics

    International Nuclear Information System (INIS)

    Avan, J.; Vega, H.J. de

    1983-01-01

    The 1/N series for a general O(N) invariant potential in quantum mechanics is analyzed in the functional integral approach. We solve the stationary-point equation (here it is a non-linear and non-local equation). The instanton solutions and their action are expressed in closed form. Potentials of different shapes are analyzed. The Kth order of the 1/N expansion for the ground state energy is obtained from the instanton solution up to order K -1 . This asymptotic formula reads in terms of quadratures of the potential. The series appears to be Borel summable for a wide class of potentials. (orig.)

  18. Carassius auratus gibelio—the most successful invasive fish in waters of the Czech Republic

    Czech Academy of Sciences Publication Activity Database

    Lusková, Věra; Lusk, Stanislav; Halačka, Karel; Vetešník, Lukáš

    2010-01-01

    Roč. 1, č. 3 (2010), s. 176-180 ISSN 2075-1117 R&D Projects: GA MŽP SP/2D4/55/07 Institutional research plan: CEZ:AV0Z60930519 Keywords : invasive alien fish * Carassius auratus gibelio * sex ratio * ploidy status * impact Subject RIV: EH - Ecology, Behaviour

  19. Biogeography and evolution of the Carassius auratus-complex in East Asia

    Directory of Open Access Journals (Sweden)

    Iguchi Kei'ichiro

    2010-01-01

    Full Text Available Abstract Background Carassius auratus is a primary freshwater fish with bisexual diploid and unisexual gynogenetic triploid lineages. It is distributed widely in Eurasia and is especially common in East Asia. Although several genetic studies have been conducted on C. auratus, they have not provided clear phylogenetic and evolutionary descriptions of this fish, probably due to selection bias in sampling sites and the DNA regions analysed. As the first step in clarifying the evolutionary entity of the world's Carassius fishes, we attempted to clarify the phylogeny of C. auratus populations distributed in East Asia. Results We conducted a detailed analysis of a large dataset of mitochondrial gene sequences [CR, 323 bp, 672 sequences (528 sequenced + 144 downloaded; CR + ND4 + ND5 + cyt b, 4669 bp in total, 53 sequences] obtained from C. auratus in East Asia. Our phylogeographic analysis revealed two superlineages, one distributed mainly among the Japanese main islands and the other in various regions in and around the Eurasian continent, including the Ryukyus and Taiwan. The two superlineages include seven lineages with high regional specificity that are composed of endemic populations indigenous to each region. The divergence time of the seven lineages was estimated to be 0.2 million years ago (Mya by a fossil-based method and 1.0-1.9 Mya by the molecular clock method. The antiquity and endemism of these lineages suggest that they are native to their respective regions, although some seem to have been affected by the artificial introduction of C. auratus belonging to other lineages. Triploids of C. auratus did not form a monophyletic lineage but were clustered mostly with sympatric diploids. Conclusions The results of the present study revealed the existence of two superlineages of C. auratus in East Asia that include seven lineages endemic to each of the seven regions examined. The lack of substantial genetic separation between triploids and

  20. Mechanism Of Environmental Franchising In The Sustainable Development Potential

    OpenAIRE

    Inna Illyashenko

    2011-01-01

    Reveals the types of environmental franchising: franchise environmental goods, manufacturing, service and environmental business format. Presents the methodological principles for the formation mechanisms of environmental franchise in implementing sustainable development potential. Proved economic, legal and organizational technology contractual relations regarding environmental franchise.

  1. New Potentials for Old: The Darboux Transformation in Quantum Mechanics

    Science.gov (United States)

    Williams, Brian Wesley; Celius, Tevye C.

    2008-01-01

    The Darboux transformation in quantum mechanics is reviewed at a basic level. Examples of how this transformation leads to exactly solvable potentials related to the "particle in a box" and the harmonic oscillator are shown in detail. The connection between the Darboux transformation and some modern operator based approaches to quantum mechanics…

  2. Skin healing and scale regeneration in fed and unfed sea bream, Sparus auratus

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    Canario Adelino VM

    2011-10-01

    Full Text Available Abstract Background Fish scales are an important reservoir of calcium and phosphorus and together with the skin function as an integrated barrier against environmental changes and external aggressors. Histological studies have revealed that the skin and scales regenerate rapidly in fish when they are lost or damaged. In the present manuscript the histological and molecular changes underlying skin and scale regeneration in fed and fasted sea bream (Sparus auratus were studied using a microarray 3 and 7 days after scale removal to provide a comprehensive molecular understanding of the early stages of these processes. Results Histological analysis of skin/scales revealed 3 days after scale removal re-epithelisation and formation of the scale pocket had occurred and 53 and 109 genes showed significant up or down-regulation, respectively. Genes significantly up-regulated were involved in cell cycle regulation, cell proliferation and adhesion, immune response and antioxidant activities. 7 days after scale removal a thin regenerated scale was visible and only minor changes in gene expression occurred. In animals that were fasted to deplete mineral availability the expression profiles centred on maintaining energy homeostasis. The utilisation of fasting as a treatment emphasised the competing whole animal physiological requirements with regard to barrier repair, infection control and energy homeostasis. Conclusions The identification of numerous genes involved in the mitotic checkpoint and cell proliferation indicate that the experimental procedure may be useful for understanding cell proliferation and control in vertebrates within the context of the whole animal physiology. In response to skin damage genes of immune surveillance were up-regulated along with others involved in tissue regeneration required to rapidly re-establish barrier function. Additionally, candidate fish genes were identified that may be involved in cytoskeletal re

  3. Identification, tissue distribution and characterization of two heat shock factors (HSFs) in goldfish (Carassius auratus).

    Science.gov (United States)

    Kim, So-Sun; Chang, Ziwei; Park, Jang-Su

    2015-04-01

    Heat shock proteins (HSPs) are synthesized rapidly in response to a variety of physiological or environmental stressors, whereas the transcriptional activation of HSPs is regulated by a family of heat shock factors (HSFs). In vertebrates, multiple HSFs (HSF1-4) have been reported to have different roles in response to a range of stresses. This paper reports the cDNA cloning of two goldfish (Carassius auratus) HSF gene families, HSF1 and three isoforms of HSF2. Both HSF1 and HSF2s showed high homology to the known HSFs from other organisms, particularly the zebrafish. Different patterns of HSF1 and HSF2 mRNA expression were detected in several goldfish tissues, highlighting their distinct roles. In cadmium (Cd)-treated tissues, the responses of HSP70 showed less difference. However, the increase in HSF1 and HSF2 in these tissues differs considerable. In particular, HSF2 was induced strongly in the heart and liver. On the other hand, in heart tissue, HSF1 showed the smallest increment. These results suggest the potential role of HSF2 in assisting HSF1 in these tissues. In another in vitro experiment of hepatocyte cultures, Cd exposure caused similar patterns of goldfish HSF1 and HSF2 mRNA expression and induction of the HSP70 protein. On the other hand, an examination of the characterization of recombinant proteins showed that HSF1 undergoes a conformation change induced by heat shock above 30 °C and approaches each other in the trimer, whereas HSF2 could not sense thermal stress directly. Furthermore, immune-blot analysis of HSFs showed that both monomers and trimmers of HSF1 were observed in cadmium-induced tissues, whereas HSF2 were all in monomeric. These results show that HSF1 and HSF2 play different roles in the transcription of heat shock proteins. Copyright © 2015 Elsevier Ltd. All rights reserved.

  4. The potential mechanisms for motor complications of Parkinson's disease

    Directory of Open Access Journals (Sweden)

    SUN Sheng-gang

    2013-08-01

    Full Text Available Parkinson's disease (PD is a common neurodegenerative disease. Dopaminergic replacement therapy is still considered as a major treatment for PD. However, long-term dopaminergic replacement therapy for PD patients is frequently associated with the development of motor complications. To date, the mechanisms underlying motor complications have not been completely understood yet. Moreover, parts of motor complications are lack of therapeutic alternatives. All these characters make this disorder difficult and challenging to manage. Increasing number of researches have been proposed in recent years for elucidating the underlying mechanisms of levodopa-related motor complications, resulting in much progression. For better understanding the management of motor complications, here we provide an overview of the current knowledge of the potential mechanisms, including the pharmacodynamic and pharmacokinetic mechanisms of levodopa and levodopa-associated neurotransmitter systems.

  5. Phenotypic and molecular variation in the green and black poison-dart frog Dendrobates auratus (Anura: Dendrobatidae) from Costa Rica

    OpenAIRE

    Lisa D Patrick; Mahmood Sasa

    2009-01-01

    The green and black poison-dart frog Dendrobates auratus exhibits high intraspecific variation in hue color and pattern throughout its range, making it a very popular species in the pet trade. We analyzed the correspondence between color variation and molecular variation of D. auratus from Costa Rica using RAPD analysis. Twenty-six random primers were analyzed for variation in 99 individuals from seven populations. Color pattern was scored from digital images of the dorsal and ventral views. ...

  6. Antidiabetic Effects of Carassius auratus Complex Formula in High Fat Diet Combined Streptozotocin-Induced Diabetic Mice

    Directory of Open Access Journals (Sweden)

    Zhi-Hong Wang

    2014-01-01

    Full Text Available Carassius auratus complex formula, including Carassius auratus, Rhizoma dioscoreae, Lycium chinense, and Rehmannia glutinosa Libosch, is a combination prescription of traditional Chinese medicine, which has always been used to treat diabetes mellitus in ancient China. In this study, we provided experimental evidence for the use of Carassius auratus complex formula in the treatment of high fat diet combined streptozotocin- (STZ- induced type 2 diabetes. Carassius auratus complex formula aqueous extract was prepared and the effects of it on blood glucose, serum insulin, adipose tissue weight, oral glucose tolerance test (OGTT, total cholesterol, and triglyceride (TG levels in mice were measured. Moreover, adiponectin, TG synthesis related gene expressions, and the inhibitory effect of aldose reductase (AR were performed to evaluate its antidiabetic effects. After the 8-week treatment, blood glucose, insulin levels, and adipose tissue weight were significantly decreased. OGTT and HOMA-IR index showed improved glucose tolerance. It could also lower plasma TG, TC, and liver TG levels. Furthermore, Carassius auratus complex formula could inhibit the activity of AR and restore adiponectin expression in serum. Based on these findings, it is suggested that Carassius auratus complex formula possesses potent anti-diabetic effects on high fat diet combined STZ-induced diabetic mice.

  7. In vivo genotoxicity evaluation of atrazine and atrazine-based herbicide on fish Carassius auratus using the micronucleus test and the comet assay.

    Science.gov (United States)

    Cavas, Tolga

    2011-06-01

    Atrazine is a selective triazine herbicide used to control broadleaf and grassy weeds mainly in corn, sorghum, sugarcane, pineapple, and other crops, and in conifer reforestation planting fields. It has been showed that atrazine is one of the most frequently detected pesticides in agricultural streams and rivers, over the past two decades. Although the toxic properties of atrazine are well known, the data on the genotoxic effects of atrazine on aquatic organisms are rather scarce. Thus, in the present study we aimed to evaluate the genotoxic effects of atrazine and an atrazine-based herbicide (Gesaprim®) on a model fish species Carassius auratus L., 1758, (Pisces: Cyprinidae) using the micronucleus test and the comet assay in peripheral blood erythrocytes. Fish were exposed to 5, 10 and 15 μg/L atrazine and to its commercial formulation for 2, 4 and 6 days. Ethyl methane sulfonate (EMS) at a single dose of 5 mg/L was used as positive control. Our results revealed significant increases in the frequencies of micronuclei and DNA strand breaks in erythrocytes of C. auratus, following exposure to commercial formulation of atrazine and thus demonstrated the genotoxic potential of this pesticide on fish. Copyright © 2011 Elsevier Ltd. All rights reserved.

  8. Yogurt and Cardiometabolic Diseases: A Critical Review of Potential Mechanisms.

    Science.gov (United States)

    Fernandez, Melissa Anne; Panahi, Shirin; Daniel, Noémie; Tremblay, Angelo; Marette, André

    2017-11-01

    Associations between yogurt intake and risk of diet-related cardiometabolic diseases (CMDs) have been the subject of recent research in epidemiologic nutrition. A healthy dietary pattern has been identified as a pillar for the prevention of weight gain and CMDs. Epidemiologic studies suggest that yogurt consumption is linked to healthy dietary patterns, lifestyles, and reduced risk of CMDs, particularly type 2 diabetes. However, to our knowledge, few to no randomized controlled trials have investigated yogurt intake in relation to cardiometabolic clinical outcomes. Furthermore, there has been little attempt to clarify the mechanisms that underlie the potential beneficial effects of yogurt consumption on CMDs. Yogurt is a nutrient-dense dairy food and has been suggested to reduce weight gain and prevent CMDs by contributing to intakes of protein, calcium, bioactive lipids, and several other micronutrients. In addition, fermentation with bacterial strains generates bioactive peptides, resulting in a potentially greater beneficial effect of yogurt on metabolic health than nonfermented dairy products such as milk. To date, there is little concrete evidence that the mechanisms proposed in observational studies to explain positive results of yogurt on CMDs or parameters are valid. Many proposed mechanisms are based on assumptions that commercial yogurts contain strain-specific probiotics, that viable yogurt cultures are present in adequate quantities, and that yogurt provides a minimum threshold dose of nutrients or bioactive components capable of exerting a physiologic effect. Therefore, the primary objective of this review is to investigate the plausibility of potential mechanisms commonly cited in the literature in order to shed light on the inverse associations reported between yogurt intake and various cardiometabolic health parameters that are related to its nutrient profile, bacterial constituents, and food matrix. This article reviews current gaps and challenges

  9. The potential role of neuropathic mechanisms in dry eye syndromes

    Directory of Open Access Journals (Sweden)

    Charles W. Mcmonnies

    2017-01-01

    Full Text Available Dry eye syndromes can involve both nociceptive and neuropathic symptoms. Nociceptive symptoms are the normal physiological responses to noxious stimuli. Neuropathic symptoms are caused by a lesion or disease of the somatosensory nervous system and can be the result of hypersensitisation of peripheral or central corneal and conjunctival somatosensory nerves. For example, inflammation could induce neuroplastic peripheral sensitisation of the ocular surface or lid wiper and exacerbate nociceptive symptoms. Neuropathic symptoms may explain the incommensurate relation between signs and symptoms in some dry eye syndromes although absence of signs of a dry eye syndrome may also be a consequence of inappropriate methods used when examining for them. Involvement of neuropathic mechanisms may also help explain dry eye symptoms which occur in association with reduced corneal sensitivity. This review includes a discussion of the potential for ocular symptoms involving neuropathic mechanisms to contribute to psychosocial problems such as depression, stress, anxiety and sleep disorders as well as for these types of psychosocial problems to contribute to neuropathic mechanisms and dry eye syndromes. Failure to consider the possibility that neuropathic mechanisms can contribute to dry eye syndromes may reduce accuracy of diagnosis and the suitability of treatment provided. Dry eye symptoms in the absence of commensurate evidence of tear dysfunction, and unsatisfactory response to tear dysfunction therapies should prompt consideration of neuropathic mechanisms being involved. Symptoms which persist after local anaesthetic instillation are more likely to be neuropathic in origin. Reducing inflammation may help limit any associated neuroplastic hypersensitivity.

  10. Action of neuro-hypophysis hormones on sodium exchanges of Carassius auratus L

    International Nuclear Information System (INIS)

    Julien, Monique

    1960-01-01

    This academic work reports the use of radio-sodium as indicator of sodium exchanges to simultaneously measure the gill input flow and the output gill and urinary flows. This technique has been applied in the case of a common soft water fish (Carassius auratus L.) to study the possible action of neuro-hypophysis extracts on these flows, and the action of these hormones on urinary excretion [fr

  11. Estudio ultraestructural en testículo de hamster vasectomizado (Mesocricetus auratus)

    OpenAIRE

    Ureña, Francisco; Malavasi, Jollyana

    2016-01-01

    The ultrastructure of adult hamster (Mesocricetus auratus) testis was studied by means of light and electron microscopes during fourteen months after bilateral vasectomy. In all the vasectomized animals there was marked degeneration of the seminiferous tubules as well as reduction of spermatogenesis. The thickening of the basal membrane was quite evident and showed extensive infolding. In the Sertoli cells, the presence of spherical or oval membrane-bound granules, vacuoles and degenerating c...

  12. Topical treatment of experimental cutaneous leishmaniasis in golden hamster (Mesocricetus auratus) with formulations containing pentamidine

    OpenAIRE

    COMANDOLLI-WYREPKOWSKI, Claudia Dantas; GRAFOVA, Iryna; NAIFF, Maricleide de Farias; AVELLA, Maurizio; GENTILE, Gennaro; GRAFOV, Andriy; FRANCO, Antonia Maria Ramos

    2017-01-01

    ABSTRACT Current treatment of cutaneous leishmaniasis (CL) relies mainly on pentavalent antimonials salts and second-line drugs include pentamidine and amphotericin B, but these therapies have side effects and require parenteral administration. The aim of this work was to evaluate the topical formulations containing pentamidine isethionate (PI) in the experimental treatment of cutaneous leishmaniasis (CL). Golden hamsters (Mesocricetus auratus) were infected in the nose with Leishmania (Leish...

  13. Erythrocyte profile of diploid and triploid silver crucian carp (Carassius auratus)

    Czech Academy of Sciences Publication Activity Database

    Vetešník, Lukáš; Halačka, Karel; Lusková, Věra; Lusk, Stanislav

    2006-01-01

    Roč. 75, č. 2 (2006), s. 203-207 ISSN 0001-7213 R&D Projects: GA ČR GA206/05/2159 Institutional research plan: CEZ:AV0Z60930519 Keywords : Carassius auratus * complete red blood count * erythrocyte nuclear dimensions Subject RIV: EG - Zoology Impact factor: 0.491, year: 2006 http://vfu-www.vfu.cz/acta-vet/vol75/75-203.pdf

  14. Music listening after stroke: beneficial effects and potential neural mechanisms.

    Science.gov (United States)

    Särkämö, Teppo; Soto, David

    2012-04-01

    Music is an enjoyable leisure activity that also engages many emotional, cognitive, and motor processes in the brain. Here, we will first review previous literature on the emotional and cognitive effects of music listening in healthy persons and various clinical groups. Then we will present findings about the short- and long-term effects of music listening on the recovery of cognitive function in stroke patients and the underlying neural mechanisms of these music effects. First, our results indicate that listening to pleasant music can have a short-term facilitating effect on visual awareness in patients with visual neglect, which is associated with functional coupling between emotional and attentional brain regions. Second, daily music listening can improve auditory and verbal memory, focused attention, and mood as well as induce structural gray matter changes in the early poststroke stage. The psychological and neural mechanisms potentially underlying the rehabilitating effect of music after stroke are discussed. © 2012 New York Academy of Sciences.

  15. The Potential Role of Cache Mechanism for Complicated Design Optimization

    International Nuclear Information System (INIS)

    Noriyasu, Hirokawa; Fujita, Kikuo

    2002-01-01

    This paper discusses the potential role of cache mechanism for complicated design optimization While design optimization is an application of mathematical programming techniques to engineering design problems over numerical computation, its progress has been coevolutionary. The trend in such progress indicates that more complicated applications become the next target of design optimization beyond growth of computational resources. As the progress in the past two decades had required response surface techniques, decomposition techniques, etc., any new framework must be introduced for the future of design optimization methods. This paper proposes a possibility of what we call cache mechanism for mediating the coming challenge and briefly demonstrates some promises in the idea of Voronoi diagram based cumulative approximation as an example of its implementation, development of strict robust design, extension of design optimization for product variety

  16. Conduction and scattering mechanisms in potential modulated inversion layers

    International Nuclear Information System (INIS)

    Almaggoussi, A.; Sicart, J.; Robert, J.L.; Vincent, G.

    1991-01-01

    A quantitative approach to the polycrystalline semiconductor model using an original e-beam irradiation method is proposed. The e-beam was scanned along lines parallel and perpendicular to the drain-source direction in a metal-oxide-semiconductor field-effect transistor (MOSFET) structure. Consequently, the electrostatic surface potential ψ s was periodically modulated and appeared similar to that of a polycrystalline semiconductor. The threshold voltage shift, effective and field-effect mobilities were measured as a function of both the irradiation period and dose. Conductivity and Hall effect measurements were performed between 4 and 400 K and a two-mobility conduction model is proposed to interpret the dependence of the carrier concentration and Hall mobility on temperature. Potential modulation scattering and screening mechanisms were studied by varying the gate voltage. The results are compared with those obtained in polysilicon thin layers and polysilicon MOSFETs

  17. Probiotics and Alcoholic Liver Disease: Treatment and Potential Mechanisms

    Directory of Open Access Journals (Sweden)

    Fengyuan Li

    2016-01-01

    Full Text Available Despite extensive research, alcohol remains one of the most common causes of liver disease in the United States. Alcoholic liver disease (ALD encompasses a broad spectrum of disorders, including steatosis, steatohepatitis, and cirrhosis. Although many agents and approaches have been tested in patients with ALD and in animals with experimental ALD in the past, there is still no FDA (Food and Drug Administration approved therapy for any stage of ALD. With the increasing recognition of the importance of gut microbiota in the onset and development of a variety of diseases, the potential use of probiotics in ALD is receiving increasing investigative and clinical attention. In this review, we summarize recent studies on probiotic intervention in the prevention and treatment of ALD in experimental animal models and patients. Potential mechanisms underlying the probiotic function are also discussed.

  18. Hatchery Vaccination Against Poultry Viral Diseases: Potential Mechanisms and Limitations.

    Science.gov (United States)

    Abdul-Cader, Mohamed Sarjoon; Palomino-Tapia, Victor; Amarasinghe, Aruna; Ahmed-Hassan, Hanaa; De Silva Senapathi, Upasama; Abdul-Careem, Mohamed Faizal

    Commercial broiler and layer chickens are heavily vaccinated against economically important viral diseases with a view of preventing morbidity, mortality, and production impacts encountered during short production cycles. Hatchery vaccination is performed through in ovo embryo vaccination prehatch or spray and subcutaneous vaccinations performed at the day of hatch before the day-old chickens are being placed in barns with potentially contaminated environments. Commercially, multiple vaccines (e.g., live, live attenuated, and viral vectored vaccines) are available to administer through these routes within a short period (embryo day 18 prehatch to day 1 posthatch). Although the ability to mount immune response, especially the adaptive immune response, is not optimal around the hatch, it is possible that the efficacy of these vaccines depends partly on innate host responses elicited in response to replicating vaccine viruses. This review focuses on the current knowledge of hatchery vaccination in poultry and potential mechanisms of hatchery vaccine-mediated protective responses and limitations.

  19. Potential Mechanisms of Cancer Prevention by Weight Control

    Science.gov (United States)

    Jiang, Yu; Wang, Weiqun

    Weight control via dietary caloric restriction and/or physical activity has been demonstrated in animal models for cancer prevention. However, the underlying mechanisms are not fully understood. Body weight loss due to negative energy balance significantly reduces some metabolic growth factors and endocrinal hormones such as IGF-1, leptin, and adiponectin, but enhances glucocorticoids, that may be associated with anti-cancer mechanisms. In this review, we summarized the recent studies related to weight control and growth factors. The potential molecular targets focused on those growth factors- and hormones-dependent cellular signaling pathways are further discussed. It appears that multiple factors and multiple signaling cascades, especially for Ras-MAPK-proliferation and PI3K-Akt-anti-apoptosis, could be involved in response to weight change by dietary calorie restriction and/or exercise training. Considering prevalence of obesity or overweight that becomes apparent over the world, understanding the underlying mechanisms among weight control, endocrine change and cancer risk is critically important. Future studies using "-omics" technologies will be warrant for a broader and deeper mechanistic information regarding cancer prevention by weight control.

  20. Potential mechanisms for imperfect synchronization in parkinsonian basal ganglia.

    Directory of Open Access Journals (Sweden)

    Choongseok Park

    Full Text Available Neural activity in the brain of parkinsonian patients is characterized by the intermittently synchronized oscillatory dynamics. This imperfect synchronization, observed in the beta frequency band, is believed to be related to the hypokinetic motor symptoms of the disorder. Our study explores potential mechanisms behind this intermittent synchrony. We study the response of a bursting pallidal neuron to different patterns of synaptic input from subthalamic nucleus (STN neuron. We show how external globus pallidus (GPe neuron is sensitive to the phase of the input from the STN cell and can exhibit intermittent phase-locking with the input in the beta band. The temporal properties of this intermittent phase-locking show similarities to the intermittent synchronization observed in experiments. We also study the synchronization of GPe cells to synaptic input from the STN cell with dependence on the dopamine-modulated parameters. Earlier studies showed how the strengthening of dopamine-modulated coupling may lead to transitions from non-synchronized to partially synchronized dynamics, typical in Parkinson's disease. However, dopamine also affects the cellular properties of neurons. We show how the changes in firing patterns of STN neuron due to the lack of dopamine may lead to transition from a lower to a higher coherent state, roughly matching the synchrony levels observed in basal ganglia in normal and parkinsonian states. The intermittent nature of the neural beta band synchrony in Parkinson's disease is achieved in the model due to the interplay of the timing of STN input to pallidum and pallidal neuronal dynamics, resulting in sensitivity of pallidal output to the phase of the arriving STN input. Thus the mechanism considered here (the change in firing pattern of subthalamic neurons through the dopamine-induced change of membrane properties may be one of the potential mechanisms responsible for the generation of the intermittent synchronization

  1. Report on the observed response of Javan lutungs (Trachypithecus auratus mauritius) upon encountering a reticulated python (Python reticulatus).

    Science.gov (United States)

    Tsuji, Yamato; Prayitno, Bambang; Suryobroto, Bambang

    2016-04-01

    We observed an encounter between a reticulated python (Python reticulatus) and a group of wild Javan lutungs (Trachypithecus auratus mauritius) at the Pangandaran Nature Reserve, West Java, Indonesia. A python (about 2 m in length) moved toward a group of lutungs in the trees. Upon seeing the python, an adult male and several adult female lutungs began to emit alarm calls. As the python approached, two adult and one sub-adult female jumped onto a branch near the python and began mobbing the python by shaking the branch. During the mobbing, other individuals in the group (including an adult lutung male) remained nearby but did not participate. The python then rolled into a ball-like shape and stopped moving, at which point the lutungs moved away. The total duration of the encounter was about 40 min, during which time the lutungs stopped feeding and grooming. Group cohesiveness during and after the encounter was greater than that before the encounter, indicating that lutungs adjust their daily activity in response to potential predation risk.

  2. Bee venom therapy: Potential mechanisms and therapeutic applications.

    Science.gov (United States)

    Zhang, Shuai; Liu, Yi; Ye, Yang; Wang, Xue-Rui; Lin, Li-Ting; Xiao, Ling-Yong; Zhou, Ping; Shi, Guang-Xia; Liu, Cun-Zhi

    2018-04-11

    Bee venom is a very complex mixture of natural products extracted from honey bee which contains various pharmaceutical properties such as peptides, enzymes, biologically active amines and nonpeptide components. The use of bee venom into the specific points is so called bee venom therapy, which is widely used as a complementary and alternative therapy for 3000 years. A growing number of evidence has demonstrated the anti-inflammation, the anti-apoptosis, the anti-fibrosis and the anti-arthrosclerosis effects of bee venom therapy. With these pharmaceutical characteristics, bee venom therapy has also been used as the therapeutic method in treating rheumatoid arthritis, amyotrophic lateral sclerosis, Parkinson's disease, Alzheimer's disease, liver fibrosis, atherosclerosis, pain and others. Although widely used, several cases still reported that bee venom therapy might cause some adverse effects, such as local itching or swelling. In this review, we summarize its potential mechanisms, therapeutic applications, and discuss its existing problems. Copyright © 2018 Elsevier Ltd. All rights reserved.

  3. Nanoparticles and potential neurotoxicity: focus on molecular mechanisms

    Directory of Open Access Journals (Sweden)

    Davide Lovisolo

    2018-01-01

    Full Text Available The last decades have seen an explosive increase in the development of nanoparticles and in their use in consumer, industrial and medical applications. Their fast diffusion has also raised widespread concern about the potential toxic effects on living organisms, including humans: at the nanoscale, they can interact with subcellular components such as membranes, proteins, lipids, nucleic acids, thus inducing unpredicted functional perturbations in cells and tissues. The nervous tissue is a particular sensitive target, because its cellular components (mainly neurons and glial cells are tightly regulated and metabolically exigent biological entities. While the literature on the potential toxicity of nanoparticles has grown in parallel with their utilization, the available data on neurotoxicity are less abundant. In particular, information on the neuronal molecular targets of nanoparticles is still largely incomplete. A better understanding of this issue is highly relevant for the rational and controlled design of nanoparticles, both for their general utilization and more specifically for their use in the promising field of nanoneuromedicine. In this review, we will discuss the available information on the mechanisms involved in the interaction between nanoobjects and cells of the nervous system, focusing on the known molecular actors, both at the plasma membrane and in intracellular compartments.

  4. Linking Pesticide Exposure with Pediatric Leukemia: Potential Underlying Mechanisms.

    Science.gov (United States)

    Hernández, Antonio F; Menéndez, Pablo

    2016-03-29

    Leukemia is the most common cancer in children, representing 30% of all childhood cancers. The disease arises from recurrent genetic insults that block differentiation of hematopoietic stem and/or progenitor cells (HSPCs) and drives uncontrolled proliferation and survival of the differentiation-blocked clone. Pediatric leukemia is phenotypically and genetically heterogeneous with an obscure etiology. The interaction between genetic factors and environmental agents represents a potential etiological driver. Although information is limited, the principal toxic mechanisms of potential leukemogenic agents (e.g., etoposide, benzene metabolites, bioflavonoids and some pesticides) include topoisomerase II inhibition and/or excessive generation of free radicals, which may induce DNA single- and double-strand breaks (DNA-DSBs) in early HSPCs. Chromosomal rearrangements (duplications, deletions and translocations) may occur if these lesions are not properly repaired. The initiating hit usually occurs in utero and commonly leads to the expression of oncogenic fusion proteins. Subsequent cooperating hits define the disease latency and occur after birth and may be of a genetic, epigenetic or immune nature (i.e., delayed infection-mediated immune deregulation). Here, we review the available experimental and epidemiological evidence linking pesticide exposure to infant and childhood leukemia and provide a mechanistic basis to support the association, focusing on early initiating molecular events.

  5. Potential Mechanisms and Functions of Intermittent Neural Synchronization

    Directory of Open Access Journals (Sweden)

    Sungwoo Ahn

    2017-05-01

    Full Text Available Neural synchronization is believed to play an important role in different brain functions. Synchrony in cortical and subcortical circuits is frequently variable in time and not perfect. Few long intervals of desynchronized dynamics may be functionally different from many short desynchronized intervals although the average synchrony may be the same. Recent analysis of imperfect synchrony in different neural systems reported one common feature: neural oscillations may go out of synchrony frequently, but primarily for a short time interval. This study explores potential mechanisms and functional advantages of this short desynchronizations dynamics using computational neuroscience techniques. We show that short desynchronizations are exhibited in coupled neurons if their delayed rectifier potassium current has relatively large values of the voltage-dependent activation time-constant. The delayed activation of potassium current is associated with generation of quickly-rising action potential. This “spikiness” is a very general property of neurons. This may explain why very different neural systems exhibit short desynchronization dynamics. We also show how the distribution of desynchronization durations may be independent of the synchronization strength. Finally, we show that short desynchronization dynamics requires weaker synaptic input to reach a pre-set synchrony level. Thus, this dynamics allows for efficient regulation of synchrony and may promote efficient formation of synchronous neural assemblies.

  6. Canada's potential role in the Clean Development Mechanism

    International Nuclear Information System (INIS)

    Pape-Salmon, A.

    2000-01-01

    The role that Canada might play in the Kyoto Protocol's Clean Development Mechanism (CDM) is discussed. The CDM prescribes the way in which industrialized countries could create emission reduction credits for greenhouse gas emission reduction projects in developing countries which, in turn they could use to meet their own commitments and possibly reduce their cost of compliance with the Kyoto Protocol. While Canada does not see itself as a CDM project investor, it strongly supports private sector involvement in the CDM and believes that it has a role to play in assisting CDM investments by the Canadian private sector by facilitating desirable outcomes via international negotiations on the rules and modalities for the CDM which would minimize transaction costs; give prominence to aspects that Canada recognizes as necessary precursors to mobilizing private sector involvement in CDM activities; maximize the flexibility for use of the CDM; allow for conversion of credits between different Kyoto Mechanisms; allow for the certification of emissions sequestration from sinks; and maximize the environmental and sustainable development benefits of CDM projects. Canada also supports, along with the other members of the 'Umbrella group', the fewest possible restrictions and significant autonomy to the private sector to implement a variety of project activities in developing countries. This report provides a detailed examination of the Canadian government's views on the CDM, Canada's participation in international emission reduction projects, the factors that drive Canadian demand for greenhouse gas emission reduction offsets and the potential demand for CDM offsets, Canada's greenhouse gas emission inventory and projections, the approach of Canadian corporate investors in the CDM and Canadian technology and expertise in greenhouse gas emission reductions. Various appendices to the report contain further details on a number of cooperation agreements between Canada and other

  7. Annatto in diets Carassius auratus goldfish fingerlings: growth performance and skin pigmentation

    Directory of Open Access Journals (Sweden)

    Edionei Maico Fries

    2014-12-01

    Full Text Available This study evaluated the effect of adding annatto as agent pigmentation on the staining characteristics of the skin, muscle and productive performance of Carassius auratus, reared in 0.15 m3 (dimensions 0.50 x 0.50 x 0.65 m hapas disposed within a circular masonry tank of 25 m3. We used 336 C. auratus fingerlings completely randomized design in 28 hapas with seven treatments and four replicates with 12 fish per unit. The addition of annatto levels were 0.0, 0.25, 0.50, 1.00, 2.00, 4.00 and 8.00%. Fish with an average initial weight of 1.12 ± 0.18 g and length of 4.31 ± 0.44 cm, were fed the 08, 11, 14 and 17 hours. The b * colorimetric characteristics (yellow showed significant at 96 and 141 days in the Hunter coordinate system with the addition of 2.0 and 1.0% annatto in the diet, respectively, and the coordinate system of CMYK and 96 days for C (cyan, and 141 days for the Y (yellow, with the addition of 8.0 to 2.0% annatto in the diet, respectively. We observed differences (P <0.05 average final weight, weight gain, feed conversion, daily growth rate and feed efficiency. It is recommended a diet containing 1.0% added annatto to C. auratus to better performance and 1.0 to 4.0% added annatto to intensified light fish skin.

  8. Mechanisms Mediating Pediatric Severe Asthma and Potential Novel Therapies

    Directory of Open Access Journals (Sweden)

    Aldara Martin Alonso

    2017-07-01

    Full Text Available Although a rare disease, severe therapy-resistant asthma in children is a cause of significant morbidity and results in utilization of approximately 50% of health-care resources for asthma. Improving control for children with severe asthma is, therefore, an urgent unmet clinical need. As a group, children with severe asthma have severe and multiple allergies, steroid resistant airway eosinophilia, and significant structural changes of the airway wall (airway remodeling. Omalizumab is currently the only add-on therapy that is licensed for use in children with severe asthma. However, limitations of its use include ineligibility for approximately one-third of patients because of serum IgE levels outside the recommended range and lack of clinical efficacy in a further one-third. Pediatric severe asthma is thus markedly heterogeneous, but our current understanding of the different mechanisms underpinning various phenotypes is very limited. We know that there are distinctions between the factors that drive pediatric and adult disease since pediatric disease develops in the context of a maturing immune system and during lung growth and development. This review summarizes the current data that give insight into the pathophysiology of pediatric severe asthma and will highlight potential targets for novel therapies. It is apparent that in order to identify novel treatments for pediatric severe asthma, the challenge of undertaking mechanistic studies using age appropriate experimental models and airway samples from children needs to be accepted to allow a targeted approach of personalized medicine to be achieved.

  9. Accumulation and health risk assessment of trace elements in Carassius auratus gibelio from subsidence pools in the Huainan coalfield in China.

    Science.gov (United States)

    Lu, Lanlan; Liu, Guijian; Wang, Jie; Liu, Yuan

    2017-08-30

    Microelement (As, Cd, Cr, Cu, Ni, Pb, and Zn) concentrations were determined in the muscle, skin, gill, and liver tissues of Carassius auratus gibelio collected from subsidence pools at three different coal mines in the Huainan coalfield in China. The concentrations of elements in the water were within the allowable levels for raising fish. However, the higher levels of these metals in sediment may pose potential harm on fish. It was found that the concentrations of Cr, Ni, and Zn in all fish tissues were higher, while As, Cd, and Pb levels were relatively low. Microelement accumulation appeared to be more widespread in subsidence pools than that in natural water. Elements accumulated in fish tissues differently: the highest metal concentrations were generally found in the liver tissues of the fish analyzed, whereas the lowest were recorded in the muscles. The mean element concentrations in muscle tissue from C. auratus gibelio collected from subsidence pools (As, 0.16 mg/kg; Cd, 0.06 mg/kg; Cr, 6.21 mg/kg; Cu, 1.61 mg/kg; Ni, 3.88 mg/kg; Pb, 1.76 mg/kg; and Zn, 12.80 mg/kg dry weight) were far below the allowable limit of the hygienic standard in fish proposed by the Ministry of Health in China, suggesting that the fish were safe for human consumption. A health risk assessment also suggested there was no risk from the analyzed elements for inhabitants near the Huainan coalfield that consume fish.

  10. The potential biological mechanisms of arsenic-induced diabetes mellitus

    International Nuclear Information System (INIS)

    Tseng, C.-H.

    2004-01-01

    Although epidemiologic studies carried out in Taiwan, Bangladesh, and Sweden have demonstrated a diabetogenic effect of arsenic, the mechanisms remain unclear and require further investigation. This paper reviewed the potential biological mechanisms of arsenic-induced diabetes mellitus based on the current knowledge of the biochemical properties of arsenic. Arsenate can substitute phosphate in the formation of adenosine triphosphate (ATP) and other phosphate intermediates involved in glucose metabolism, which could theoretically slow down the normal metabolism of glucose, interrupt the production of energy, and interfere with the ATP-dependent insulin secretion. However, the concentration of arsenate required for such reaction is high and not physiologically relevant, and these effects may only happen in acute intoxication and may not be effective in subjects chronically exposed to low-dose arsenic. On the other hand, arsenite has high affinity for sulfhydryl groups and thus can form covalent bonds with the disulfide bridges in the molecules of insulin, insulin receptors, glucose transporters (GLUTs), and enzymes involved in glucose metabolism (e.g., pyruvate dehydrogenase and α-ketoglutarate dehydrogenase). As a result, the normal functions of these molecules can be hampered. However, a direct effect on these molecules caused by arsenite at physiologically relevant concentrations seems unlikely. Recent evidence has shown that treatment of arsenite at lower and physiologically relevant concentrations can stimulate glucose transport, in contrary to an inhibitory effect exerted by phenylarsine oxide (PAO) or by higher doses of arsenite. Induction of oxidative stress and interferences in signal transduction or gene expression by arsenic or by its methylated metabolites are the most possible causes to arsenic-induced diabetes mellitus through mechanisms of induction of insulin resistance and β cell dysfunction. Recent studies have shown that, in subjects with chronic

  11. Ranking mechanical pulps for their potential to photoyellow

    Science.gov (United States)

    Umesh P. Agarwal

    2000-01-01

    Recently found experimental evidence has provided strong support for an alternative photoyellowing mechanism that suggests that pulp- photoyellowing occurs due to direct photooxidation of hydroquinones (present in mechanical pulps) top-quinones. Because hydroquinones were found to be present in pulps, it may be possible to quantify them. Quantification of mechanical-...

  12. Potential Mechanisms Underlying Centralized Pain and Emerging Therapeutic Interventions

    Directory of Open Access Journals (Sweden)

    Olivia C. Eller-Smith

    2018-02-01

    Full Text Available Centralized pain syndromes are associated with changes within the central nervous system that amplify peripheral input and/or generate the perception of pain in the absence of a noxious stimulus. Examples of idiopathic functional disorders that are often categorized as centralized pain syndromes include fibromyalgia, chronic pelvic pain syndromes, migraine, and temporomandibular disorder. Patients often suffer from widespread pain, associated with more than one specific syndrome, and report fatigue, mood and sleep disturbances, and poor quality of life. The high degree of symptom comorbidity and a lack of definitive underlying etiology make these syndromes notoriously difficult to treat. The main purpose of this review article is to discuss potential mechanisms of centrally-driven pain amplification and how they may contribute to increased comorbidity, poorer pain outcomes, and decreased quality of life in patients diagnosed with centralized pain syndromes, as well as discuss emerging non-pharmacological therapies that improve symptomology associated with these syndromes. Abnormal regulation and output of the hypothalamic-pituitary-adrenal (HPA axis is commonly associated with centralized pain disorders. The HPA axis is the primary stress response system and its activation results in downstream production of cortisol and a dampening of the immune response. Patients with centralized pain syndromes often present with hyper- or hypocortisolism and evidence of altered downstream signaling from the HPA axis including increased Mast cell (MC infiltration and activation, which can lead to sensitization of nearby nociceptive afferents. Increased peripheral input via nociceptor activation can lead to “hyperalgesic priming” and/or “wind-up” and eventually to central sensitization through long term potentiation in the central nervous system. Other evidence of central modifications has been observed through brain imaging studies of functional

  13. Sex differences in ischaemic stroke: potential cellular mechanisms.

    Science.gov (United States)

    Chauhan, Anjali; Moser, Hope; McCullough, Louise D

    2017-04-01

    Stroke remains a leading cause of mortality and disability worldwide. More women than men have strokes each year, in part because women live longer. Women have poorer functional outcomes, are more likely to need nursing home care and have higher rates of recurrent stroke compared with men. Despite continued advancements in primary prevention, innovative acute therapies and ongoing developments in neurorehabilitation, stroke incidence and mortality continue to increase due to the aging of the U.S. Sex chromosomes (XX compared with XY), sex hormones (oestrogen and androgen), epigenetic regulation and environmental factors all contribute to sex differences. Ischaemic sensitivity varies over the lifespan, with females having an "ischaemia resistant" phenotype that wanes after menopause, which has recently been modelled in the laboratory. Pharmacological therapies for acute ischaemic stroke are limited. The only pharmacological treatment for stroke approved by the Food and Drug Administration (FDA) is tissue plasminogen activator (tPA), which must be used within hours of stroke onset and has a number of contraindications. Pre-clinical studies have identified a number of potentially efficacious neuroprotective agents; however, nothing has been effectively translated into therapy in clinical practice. This may be due, in part, to the overwhelming use of young male rodents in pre-clinical research, as well as lack of sex-specific design and analysis in clinical trials. The review will summarize the current clinical evidence for sex differences in ischaemic stroke, and will discuss sex differences in the cellular mechanisms of acute ischaemic injury, highlighting cell death and immune/inflammatory pathways that may contribute to these clinical differences. © 2017 The Author(s). published by Portland Press Limited on behalf of the Biochemical Society.

  14. Survivin-T34A: molecular mechanism and therapeutic potential

    Directory of Open Access Journals (Sweden)

    Jonathan R Aspe

    2010-12-01

    Full Text Available Jonathan R Aspe, Nathan R WallCenter for Health Disparities Research and Molecular Medicine, Division of Biochemistry and Microbiology, Department of Basic Sciences, Loma Linda University, Loma Linda, CA, USAAbstract: The inhibitor of apoptosis protein survivin's threonine 34 to alanine (T34A mutation abolishes a phosphorylation site for p34(cdc2–cyclin B1, resulting in initiation of the mitochondrial apoptotic pathway in cancer cells; however, it has little known direct effects on normal cells. The possibility that targeting survivin in this way may provide a novel approach for selective cancer gene therapy has yet to be fully evaluated. Although a flurry of work was undertaken in the late 1990s and early 2000s, only minor advances on this mutant have recently taken place. We recently described that cells generated to express a stable form of the mutant protein released this survivin-T34A to the conditioned medium. When this conditioned medium was collected and deposited on naive tumor cells, conditioned medium T34A was as effective as some chemotherapeutics in the induction of tumor cell apoptosis, and when combined with other forms of genotoxic stressors potentiated their killing effects. We hope with this review to revitalize the T34A field, as there is still much that needs to be investigated. In addition to determining the therapeutic dose and the duration of drug therapy required at the disease site, a better understanding of other key factors is also important. These include knowledge of target cell populations, cell-surface receptors, changes that occur in the target tissue at the molecular and cellular level with progression of the disease, and the mechanism and site of therapeutic action.Keywords: survivin, T34A, apoptosis, proliferation, therapy

  15. Common carp (Cyprinus carpio) and goldfish (Carassius auratus) were not susceptible to challenge with ranavirus under certain challenge conditions

    DEFF Research Database (Denmark)

    Jensen, Britt Bang; Reschova, S.; Cinkova, K.

    2011-01-01

    Goldfish, Carassius auratus, and common carp, Cyprinus carpio, were challenged with a panel of 8 different piscine and amphibian ranavirus isolates. Goldfish were exposed at a water temperature of 16 degrees C and 23 degrees C, and carp at 15 degrees C and 25 degrees C. No significant mortality...

  16. Many branches, one root: First evidence for a monophyly of the morphologically highly diverse goldfish (Carassius auratus)

    Czech Academy of Sciences Publication Activity Database

    Rylková, K.; Kalous, L.; Šlechtová, Vendula; Bohlen, Jörg

    2010-01-01

    Roč. 302, 1-2 (2010), s. 36-41 ISSN 0044-8486 R&D Projects: GA ČR GA206/05/2159 Institutional research plan: CEZ:AV0Z50450515 Keywords : Goldfish * Carassius auratus * Phylogenetics Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 2.044, year: 2010

  17. Review and assessment of mechanic village potentials for small ...

    African Journals Online (AJOL)

    This is suggested because developing countries are yet to enforce environmentally friendly automobile workshops and mechanic practice. If all automobile repair works in different cities are confined to mechanic villages, collection, preservation, recycling and reuse of spent oil will become effective. The goal is to stop the ...

  18. Enzymatic complex in diets for gold fish fingerlings (Carassius auratusComplexo enzimático na dieta de alevinos de kinguio (Carassius auratus

    Directory of Open Access Journals (Sweden)

    Arcângelo Augusto Signor

    2013-06-01

    Full Text Available Aiming to evaluate the enzymatic complex supplementation in diets for goldfish fingerlings (Carassius auratus, 240 fish weighing initially 1,36 ± 0,02g, randomly distributed in 20 tanks with 150L, in four treatments and five replications, with twelve fish in each experimental unit were used. The fish were fed at 8:00 and 11:00 a.m. and 2:00 and 5:00 p.m. with diets containing different inclusion levels (0; 0,033; 0,066 e 0,099% of enzymatic complex (amilase, protease, celulase, lipase, ?-glucanase and phytase, and formulated with 32,36% of digestible protein and 3.023kcal of digestible energy kg-1. There were no differences observed (P>0,05 in the mean final weight, weight gain, total length, standard length, survival and carcass composition. However, the fish apparent feed conversion was impaired by the supplementation of enzymatic complex with 0,099% in diet. The use of enzymatic complex does not provides benefits in the productive performance for goldfish fingerlings. Objetivando avaliar a suplementação de complexo enzimático em dietas de alevinos de kinguios (Carassius auratus, foram utilizados 240 peixes com peso inicial de 1,36 ± 0,02g, distribuídos aleatoriamente, em 20 tanques de 150L, em quatro tratamentos e cinco repetições, com 12 peixes em cada unidade experimental. Os peixes foram arraçoados as 8h, 11h, 14h e 17h, com dietas contendo diferentes níveis de inclusão (0; 0,033; 0,066 e 0,099% de complexo enzimático (amilase, protease, celulase, lipase, b-glucanase e fitase, e formuladas para conter 32,36% de proteína digestível e 3.023kcal de energia digestível kg-1. Não foram observadas diferenças no peso final, ganho de peso, comprimento total, comprimento padrão, sobrevivência e composição de carcaça. No entanto, a conversão alimentar aparente dos peixes alimentados com rações contendo 0,099% do complexo enzimático foi inferior em relação aos alimentados com as demais dietas. Conclui-se que a utiliza

  19. Crescimento e sobrevivência de larvas de peixe vermelho (Carassius auratus alimentadas com microdietas comerciais Growth and survival of Carassius auratus larvae fed commercial micro diets

    Directory of Open Access Journals (Sweden)

    P. Rema

    2009-06-01

    Full Text Available Para avaliar o desempenho de dois alimentos comerciais para larvas de peixes ornamentais e analisar o efeito que a suplementação em vitaminas e minerais teria sobre a sobrevivência e o crescimento dessas, foi realizado um ensaio de crescimento de 21 dias, com 4800 larvas de peixe vermelho (Carassius auratus, distribuídas por 24 grupos (200 indivíduos por grupo. Cada grupo foi alojado em tanques de 5L de capacidade, ligados a um sistema de recirculação de água. Quatro grupos foram alocados a um controle de jejum, em que os animais não foram alimentados, e os restantes 20 grupos foram utilizados em cinco tratamentos, em quadruplicado. Em cada um dos cinco tratamentos, os peixes ingeriram uma das seguintes dietas: R (referência, C1 (SERA vipan® baby, C2 (SERA® microgran, C1v e C2v (C1 e C2, respectivamente, reforçadas em vitaminas e minerais. As taxas de sobrevivência e crescimento dos peixes do tratamento R foram maiores que as obtidas nos outros tratamentos (PA 21-day growth trial was performed to evaluate two ornamental fish larvae commercial diets and the effect of mineral and vitamin supplementation of the same commercial microdiets on growth and survival of goldfish larvae (Carassius auratus. A total of 4,800 larvae were randomly distributed in 24 groups of 200 individuals. Each group was housed in a 5L tank, connected to a recirculating water system. Four groups were assigned to a fastening control. The animals in these groups did not receive any food. The remaining 20 groups were distributed in five treatments, in quadruplicate. The animals of each treatment were fed one of five experimental diets: R (reference, C1 (SERA vipan® baby, C2 (SERA® microgran, C1v, and C2v (C1 and C2, respectively, reinforced with minerals and vitamins. At the end of the trial, high survival and growth rates were observed in R treatment. There were significant differences in total length and total weight among dietary treatments. Considering the

  20. Potential Role of Probiotics in Mechanism of Intestinal Immunity

    Directory of Open Access Journals (Sweden)

    Imran Rashid Rajput and Wei Fen Li*

    2012-06-01

    Full Text Available Probiotics are nonpathogenic bacteria exert a constructive influence on health or physiology of the host. Effect of probiotics in the intestinal defense against variety of diseases is well known. The probiotics are involved in the mechanism of intestinal defense, support as antagonist against pathogens, improve intestinal epithelial layer and boost the innate as well as adaptive immunity. However these responses are also exerted by intestinal components. The intestinal components as well as probiotics play a reciprocal role to enhance the immune response of the individual. The possibilities of mechanism of action include the stimulation of epithelial cells, activation of dendritic cells via toll-like receptors (TLRs, conversely produce cytokines. These observations reviewed together advocate that specific immunomodulatory properties of probiotic bacteria should be focusing on mechanism of action via antigen presenting cells (APC.

  1. Performance potential of mechanical ventilation systems with minimized pressure loss

    DEFF Research Database (Denmark)

    Terkildsen, Søren; Svendsen, Svend

    2013-01-01

    In many locations mechanical ventilation has been the most widely used principle of ventilation over the last 50 years but the conventional system design must be revised to comply with future energy requirements. This paper examines the options and describes a concept for the design of mechanical....... This corresponds to 10-15% of the power consumption for conventional mechanical ventilation systems thus enabling the system to fulfil future energy requirements in buildings....... ventilation systems with minimal pressure loss and minimal energy use. This can provide comfort ventilation and avoid overheating through increased ventilation and night cooling. Based on this concept, a test system was designed for a fictive office building and its performance was documented using building...

  2. On Mechanical Mixed Potential, Content and Co-Content

    NARCIS (Netherlands)

    Jeltsema, Dimitri; Scherpen, Jacquelien M.A.

    2003-01-01

    In this paper a novel co-energy modelling framework is presented for a relevant class of linear and nonlinear mechanical systems. The approach uses the classical Brayton-Moser equations which are deduced from a (port-)Hamiltonian description. The approach allows classical results from electrical

  3. Potential mechanisms behind contrast medium-induced nephropathy

    African Journals Online (AJOL)

    How contrast medium-induced nephropathy (CIN) comes about is poorly understood, although CIN is a common cause of acute renal failure. Hitherto, the various studies performed have led to different interpretations and partially contradictory conclusions. This article aimed to review the mechanisms underlying CIN and to ...

  4. Child Care Subsidy Use and Child Development: Potential Causal Mechanisms

    Science.gov (United States)

    Hawkinson, Laura E.

    2011-01-01

    Research using an experimental design is needed to provide firm causal evidence on the impacts of child care subsidy use on child development, and on underlying causal mechanisms since subsidies can affect child development only indirectly via changes they cause in children's early experiences. However, before costly experimental research is…

  5. Antioxidative and proline potentials as a protective mechanism in ...

    African Journals Online (AJOL)

    Stress can define as all negative factors affecting plant growth. One of the most important problems among stress factors is salt stress. Antioxidant responses are tested in Soybean (Glycine max. L.) cv., “A3935” grown under 0, 50, 100 and 150 mM NaCl in order to investigate the plants protective mechanisms against salt ...

  6. Condition factor and diet of Chrysichthys nigrodigitatus and Chrysichthys auratus (Siluriformes: Bagridae from Aiba Reservoir, Iwo, Nigeria

    Directory of Open Access Journals (Sweden)

    Oluwatosin Ebenezer Atobatele

    2011-09-01

    Full Text Available Chrysichthys nigrodigitatus and C. auratus are important, highly valued and threatened freshwater species. To contribute with their ecological knowledge, the condition factor and diet of these two congeneric species were studied between April 2005 and April 2006. Food items of fish were evaluated by occurrence and numerical abundance methods, and the possible changes among sexes, seasons and sizes were considered. Results showed that generally C. nigrodigitatus were better conditioned than C. auratus. The males of C. nigrodigitatus and females of C. auratus were in better condition than their respective opposite sex throughout the year, and during the wet season compared to the dry. The food items of C. nigrodigitatus and C. auratus were similar and comprised twelve species belonging to five groups: Insecta (three species, Crustacea (five species, Arachnida (one species, Rotifera (one species and Mollusca (two species. Other food items included fish scales, unidentified green eggs, plant parts, detritus and sand. Insecta and Crustacea dominated the food items in both species. For C. nigrodigitatus, insect consumption increased with fish size, while Crustacea items decreased (from 89.59% for 8.1cm - 12.0cm size class to 1.58% for 20.1cm - 26.0cm size class. However, while C. auratus smaller sized fish preferred Crustacea (98.72% for 8.1cm -12.0cm size class, larger sized fish had both groups in relatively similar amounts. Schoener Overlap Index for both species and between seasons is 1.00. Diet breadth ranged from 0.00-1.47 for C. nigrodigitatus and 0.00-1.32 for C. auratus. Food Richness ranged from 0.00-1.44 for both species. Gut Repletion Index for C. nigrodigitatus and C. auratus are 76.39% and 76.27% respectively. Although, there is considerable similarity and overlap in the utilization of food resource for both coexisting species, condition factor and feeding behavior suggest strategies to reduce intra- and inter-specific competition. Rev

  7. Performance potential of mechanical ventilation systems with minimized pressure loss

    DEFF Research Database (Denmark)

    Terkildsen, Søren; Svendsen, Svend

    2013-01-01

    simulations that quantify fan power consumption, heating demand and indoor environmental conditions. The system was designed with minimal pressure loss in the duct system and heat exchanger. Also, it uses state-of-the-art components such as electrostatic precipitators, diffuse ceiling inlets and demand......In many locations mechanical ventilation has been the most widely used principle of ventilation over the last 50 years but the conventional system design must be revised to comply with future energy requirements. This paper examines the options and describes a concept for the design of mechanical...... ventilation systems with minimal pressure loss and minimal energy use. This can provide comfort ventilation and avoid overheating through increased ventilation and night cooling. Based on this concept, a test system was designed for a fictive office building and its performance was documented using building...

  8. Mental imagery in music performance: underlying mechanisms and potential benefits.

    Science.gov (United States)

    Keller, Peter E

    2012-04-01

    This paper examines the role of mental imagery in music performance. Self-reports by musicians, and various other sources of anecdotal evidence, suggest that covert auditory, motor, and/or visual imagery facilitate multiple aspects of music performance. The cognitive and motor mechanisms that underlie such imagery include working memory, action simulation, and internal models. Together these mechanisms support the generation of anticipatory images that enable thorough action planning and movement execution that is characterized by efficiency, temporal precision, and biomechanical economy. In ensemble performance, anticipatory imagery may facilitate interpersonal coordination by enhancing online predictions about others' action timing. Overlap in brain regions subserving auditory imagery and temporal prediction is consistent with this view. It is concluded that individual differences in anticipatory imagery may be a source of variation in expressive performance excellence and the quality of ensemble cohesion. Engaging in effortful musical imagery is therefore justified when artistic perfection is the goal. © 2012 New York Academy of Sciences.

  9. Sleep Duration and Diabetes Risk: Population Trends and Potential Mechanisms

    Science.gov (United States)

    Grandner, Michael A.; Seixas, Azizi; Shetty, Safal; Shenoy, Sundeep

    2016-01-01

    Sleep is important for regulating many physiologic functions that relate to metabolism. Because of this, there is substantial evidence to suggest that sleep habits and sleep disorders are related to diabetes risk. In specific, insufficient sleep duration and/or sleep restriction in the laboratory, poor sleep quality, and sleep disorders such as insomnia and sleep apnea have all been associated with diabetes risk. This research spans epidemiologic and laboratory studies. Both physiologic mechanisms such as insulin resistance, decreased leptin, and increased ghrelin and inflammation and behavioral mechanisms such as increased food intake, impaired decision-making, and increased likelihood of other behavioral risk factors such as smoking, sedentary behavior, and alcohol use predispose to both diabetes and obesity, which itself is an important diabetes risk factor. This review describes the evidence linking sleep and diabetes risk at the population and laboratory levels. PMID:27664039

  10. Antioxidative and proline potentials as a protective mechanism in ...

    African Journals Online (AJOL)

    Jane

    2011-07-04

    Jul 4, 2011 ... The plants were uprooted randomly on 30 DAS and the enzymatic antioxidant potentials were analyzed. The fresh and dry weights and the chlorophyll content are reduced with increasing NaCl concentration. Proline concentration increased at high salinity compared to untreated plants. Moreover, salinity ...

  11. Antioxidative and proline potentials as a protective mechanism in ...

    African Journals Online (AJOL)

    Jane

    2011-07-04

    Jul 4, 2011 ... Stress can define as all negative factors affecting plant growth. One of the most important problems among stress factors is salt stress. Antioxidant responses ... High-salt stress disrupts the homeostasis in water potential and ion distribution at both the cellular and the whole plant levels (Errabii et al., 2007).

  12. Mechanism of the potentiation of thrombolysis by pentoxifylline (Trental)

    Energy Technology Data Exchange (ETDEWEB)

    Ambrus, J.L.; Ambrus, C.M.; Mahfzah, M.; Markus, J.A.; Klein, E.; Gastpar, H.

    1987-01-01

    Streptokinase induced thrombolysis of radioactive labeled human fibrin clots was potentiated by simultaneous treatment with pentoxifylline (Trental). This appears to be due in part to the prevention of platelet aggregation on the clot. In addition, release of t-PA and PgI2 from the endothelium and increases in red cell deformability may also play a role.

  13. MALATHION INDUCED HISTOLOGICAL MODIFICATIONS IN GILLS AND KIDNEY OF CARASSIUS AURATUS GIBELIO

    Directory of Open Access Journals (Sweden)

    ANDREA CRISTINA STAICU

    2008-05-01

    Full Text Available Malathion is an organophosphorous insecticide, used in agriculture and a possible source of environmental poisoning. During malathion metabolization, mitochondria generates reactive oxygen species, responsible for significant structural changes. In this study, gills and kidney histological changes in Carassius auratus gibelio exposed to 0.05 mg/l malathion were investigated. In kidney, the effects were dramatic. The 24 -72 hours exposure to malathion induced cytoplasm vacuolization and changes in cell and nuclear volumes. In addition, necrotic renal tubules appeared, nuclear malformations of epithelial cells, anisokary, nuclei pycnosis and nuclei hypertrophy, were noticed. Epithelial ruptures, secondary lamellae fusion and hyperplasia of branchial epithelium, vascular congestion were the main changes noticed soon after pollutant exposure. We suggest that structural changes in gill and kidney could be used as good response to aquatic pollution with organophosphorous insecticides.

  14. Hamsters' (Mesocricetus auratus) memory in a radial maze analog: the role of spatial versus olfactory cues.

    Science.gov (United States)

    Tonneau, François; Cabrera, Felipe; Corujo, Alejandro

    2012-02-01

    The golden hamster's (Mesocricetus auratus) performance on radial maze tasks has not been studied a lot. Here we report the results of a spatial memory task that involved eight food stations equidistant from the center of a circular platform. Each of six male hamsters depleted the food stations along successive choices. After each choice and a 5-s retention delay, the hamster was brought back to the center of the platform for the next choice opportunity. When only one baited station was left, the platform was rotated to evaluate whether olfactory traces guided hamsters' choices. Results showed that despite the retention delay hamsters performed above chance in searching for food. The choice distributions observed during the rotation probes were consistent with spatial memory and could be explained without assuming guidance by olfactory cues. The radial maze analog we devised could be useful in furthering the study of spatial memory in hamsters.

  15. LDH ACTIVITY IN COPPER INTOXICATION OF CARASSIUS AURATUS GIBELIO GILLS AND INTESTINE

    Directory of Open Access Journals (Sweden)

    DANIELA TEODORESCU

    2008-05-01

    Full Text Available The pathological effects of two sublethal concentrations (100 μg/l and 250 μg/l of copper (CuSO4x5H2O on goldfish Carassius auratus gibelio were studied for 7,14 and 21 days. The specific activity of LDH in gills and intestine, two target organs that uptake the metal from the water were assayed. In gills at 100 μg Cu2+/l the specific activity of LDH was gradually decreasing, while in the intestine, after 7 days of exposure, the enzymatic activity was distinct significantly increased. LDH activity demonstrated a hypoxic condition and a stimulation of glycolysis. In the both organs ,the 250 μg Cu2+/l concentration generated a decrease of LDH specific activity after 7 days followed by an increase of this after 14 and 21 days of exposure. Histologically, the modifications are, generally, directly correlated with the toxicant dose and exposure time.

  16. Negative effect of 17-beta-estradiol on growth parameters of goldfish (Carassius auratus

    Directory of Open Access Journals (Sweden)

    Reza Tarkhani

    2015-03-01

    Full Text Available Objective: To evaluate the effects of 17-beta-estradiol on growth factors of goldfish (Carassius auratus. Methods: To perform the test, 17-beta-estradiol was given 3 months period to fish at different doses as followed: control group, Group 1: 10 mg/kg food, Group 2: 25 mg/kg food and Group 3: 50 mg/kg food. For this purpose, a solution of hormone in pure ethanol used to spray on food. Feeding was done 3 times daily as an appetite. Comparing the mean values measured for length and weight using ANOVA. Results: Indicated with increase length and weight, the effects of the hormone get more distinct, so that with increase concentration of hormone, reduce weight and length. Conclusions: Estradiol along with testosterone and progesterone regulates final stages of oocyte maturation and ovulation. Various studies have proven the different concentrations of this hormone has different effects on the growth of different fishes.

  17. Memory for individual scent in hamsters (Mesocricetus auratus) as assessed by habituation methods.

    Science.gov (United States)

    Johnston, R E

    1993-06-01

    The memory of hamsters (Mesocricetus auratus) for the flank scent of other male hamsters was investigated in a series of habituation experiments. In 2 types of habituation tasks (Experiments 1 and 2), male hamsters habituated to the flank scent of 1 male and then increased their level of investigation to that of a novel male; similar results were obtained when the intervals between trials ranged from 1 s to 2 days. When the test trial was 10 or 21 days after habituation (Experiment 3), males discriminated between familiar and novel flank scents at 10 days but not at 21 days. The results demonstrate recognition of familiar and unfamiliar individual odors and excellent memory for these differences. Habituation techniques yield extremely robust results and may be useful for investigations of other aspects of individual signatures.

  18. EGFR transactivation: mechanisms, pathophysiology and potential therapies in cardiovascular system

    Science.gov (United States)

    Forrester, Steven J.; Kawai, Tatsuo; Elliott, Katherine J.; O’Brien, Shannon; Thomas, Walter; Harris, Raymond C.; Eguchi, Satoru

    2017-01-01

    Accumulating studies suggest that the epidermal growth factor receptor (EGFR) activation is associated with the physiology and pathophysiology of the cardiovascular system, and inhibition of EGFR activity is emerging as a potential therapeutic strategy to treat diseases, including hypertension, cardiac hypertrophy, renal fibrosis and abdominal aortic aneurysm. The capacity of G protein-coupled receptor (GPCR) agonists, such as angiotensin II (AngII), to promote EGFR signaling is well described – a process termed EGFR “transactivation” – yet delineating the molecular processes and functional relevance of this crosstalk has been challenging. Moreover, these critical findings are dispersed among many different fields. The aim of our review is to highlight the recent advancement of the signaling cascades and downstream consequences of EGFR transactivation within the cardiovascular renal system in vitro and in vivo. We will also focus on linking EGFR transactivation to animal models of the disease as well as the potential therapeutic applications. PMID:26566153

  19. THE ACTION OF CORAGEN INSECTICIDE ON CERTAIN PHYSIOLOGICAL BIOMARKERS ON CARASSIUS AURATUS GIBELIO BLOCH L. 1758

    Directory of Open Access Journals (Sweden)

    Claudiu Alexandru Baciu

    2015-12-01

    Full Text Available In our researches we have determined the variation of certain physiological indexes, such as the oxygen consume, the breathing rhythm, the glycaemia and the number of red blood cells under the action of Coragen insecticide on Carassius auratus gibelio Bloch. Under the action of Coragen, we have registered significant changes in the oxygen consume, the breathing rhythm, the number of red blood cells and glycemia at the Carassius auratus gibelio Bloch items, considered as answers to the stress provoked by emissions. The highest variations of the physiological indexes, from the perspective of the percentage, were noticed at the glycemia, which at the mark was 28 mg/dl, and in the treated sample, with 0.1 ml/l Coragen is 42 mg/dl, representing a 50% growth and at the breathing rhythm in 24 hours, where values significantly decreased with 41.18% at the concentration of 0.07 ml/l and with 39.33% at the concentrations of 0.05 and 0.1 ml/l Coragen. The slightest variations of the physiological indexes, from the perspective of percentage, were noticed at the oxygen consumption, which, at the mark is of 55.302 ml oxygen/kg/hour, and for the treated sample, with 0.1 ml/l Coragen is 34.81 ml oxygen/kg/hour, representing a decrease of 37.06% in 24 hours and the number of red blood cells, where the values have significantly decrease with 9.58%, 13.48%, respectively 18.44% for the concentrations of 0.05, 0.07 and 0.1 ml/l Coragen.

  20. POTENTIAL PATHOPHYSIOLOGICAL MECHANISMS OF ULTRAFINE PARTICLE TOXIC EFFECTS IN HUMANS

    Directory of Open Access Journals (Sweden)

    JASMINA JOVIĆ-STOŠIĆ

    2008-03-01

    Full Text Available Epidemiological and clinical studies suggested the association of the particulate matter ambient air pollution and the increased morbidity and mortality, mainly from respiratory and cardiovascular diseases. The size of particles has great influence on their toxicity, because it determines the site in the respiratory tract where they deposit. The most well established theory explaining the mechanisms behind the increased toxicity of ultrafine particles (UFP, < 0.1 µm is that it has to do with the increased surface area and/or the combination with the increased number of particles. Biological effects of UFP are also determined by their shape and chemical composition, so it is not possible to estimate their toxicity in a general way. General hypothesis suggested that exposure to inhaled particles induces pulmonary alveolar inflammation as a basic pathophysiological event, triggering release of various proinflammatory cytokines. Chronic inflammation is a very important underlying mechanism in the genesis of atherosclerosis and cardiovascular diseases. UFP can freely move through the circulation, but their effects on the secondary organs are not known yet, so more studies on recognizing toxicological endpoints of UFP are needed. Determination of UFP toxicity and the estimation of their internal and biologically active dose are necessary for the evidence based conclusions connecting air pollution by UFP and human diseases.

  1. Antidiabetic potentials of Momordica charantia: multiple mechanisms behind the effects.

    Science.gov (United States)

    Chaturvedi, Padmaja

    2012-02-01

    Momordica charantia fruits are used as a vegetable in many countries. From time immemorial, it has also been used for management of diabetes in the Ayurvedic and Chinese systems of medicine. Information regarding the standardization of this vegetable for its usage as an antidiabetic drug is scanty. There are many reports on its effects on glucose and lipid levels in diabetic animals and some in clinical trials. Reports regarding its mechanism of action are limited. So in the present review all the information is considered to produce some concrete findings on the mechanism behind its hypoglycemic and hypolipidemic effects. Studies have shown that M. charantia repairs damaged β-cells, increases insulin levels, and also enhance the sensitivity of insulin. It inhibits the absorption of glucose by inhibiting glucosidase and also suppresses the activity of disaccharidases in the intestine. It stimulates the synthesis and release of thyroid hormones and adiponectin and enhances the activity of AMP-activated protein kinase (AMPK). Effects of M. charantia like transport of glucose in the cells, transport of fatty acids in the mitochondria, modulation of insulin secretion, and elevation of levels of uncoupling proteins in adipose and skeletal muscles are similar to those of AMPK and thyroxine. Therefore it is proposed that effects of M. charantia on carbohydrate and fat metabolism are through thyroxine and AMPK.

  2. Molecular mechanism and potential targets for bone metastasis

    International Nuclear Information System (INIS)

    Iguchi, Haruo

    2007-01-01

    The incidence of bone metastasis has been increasing in all cancers in recent years. Bone metastasis is associated with substantial morbidity, including bone pain, pathological fracture, neurological deficit and/or hypercalcemia. Thus, the management of bone metastasis in patients is a clinically significant issue. In the process of bone metastasis, the primary mechanism responsible for bone destruction is cancer cell-mediated stimulation of osteoclastic bone resorption, which results in osteolysis and release of various growth factors from the bone matrix. These growth factors are prerequisites for successful colonization and subsequent invasive growth of cancer cells in bone, which is called a 'vicious cycle.' Thus, it is important to elucidate what molecules are involved in this step of bone destruction, and the understanding of these molecular mechanisms could lead to develop molecular-target therapies for bone metastasis. Bisphosphonates introduced in the treatment for bone metastasis have been shown to reduce skeletal morbidity. In Japan, the most potent bisphosphonate, zoledronate (ZOMETA), was introduced in this past April, and a phase III clinical trial of humanized anti-receptor activator of NF-κB ligand (RANKL) monoclonal antibody (Denosumab) against bone metastasis is under way as a global study. These new agents, which are targeted to osteoclasts, are considered to be standard management in the care of bone metastasis patients in combination with chemotherapy and/or hormone therapy. (author)

  3. Cap buckling as a potential mechanism of atherosclerotic plaque vulnerability.

    Science.gov (United States)

    Abdelali, Maria; Reiter, Steven; Mongrain, Rosaire; Bertrand, Michel; L'Allier, Philippe L; Kritikou, Ekaterini A; Tardif, Jean-Claude

    2014-04-01

    Plaque rupture in atherosclerosis is the primary cause of potentially deadly coronary events, yet about 40% of ruptures occur away from the plaque cap shoulders and cannot be fully explained with the current biomechanical theories. Here, cap buckling is considered as a potential destabilizing factor which increases the propensity of the atherosclerotic plaque to rupture and which may also explain plaque failure away from the cap shoulders. To investigate this phenomenon, quasistatic 2D finite element simulations are performed, considering the salient geometrical and nonlinear material properties of diverse atherosclerotic plaques over the range of physiological loads. The numerical results indicate that buckling may displace the location of the peak von Mises stresses in the deflected caps. Plaque buckling, together with its deleterious effects is further observed experimentally in plaque caps using a physical model of deformable mock coronary arteries with fibroatheroma. Moreover, an analytical approach combining quasistatic equilibrium equations with the Navier-Bresse formulas is used to demonstrate the buckling potential of a simplified arched slender cap under intraluminal pressure and supported by foundations. This analysis shows that plaque caps - calcified, fibrotic or cellular - may buckle in specific undulated shapes once submitted to critical loads. Finally, a preliminary analysis of intravascular ultrasonography recordings of patients with atherosclerotic coronary arteries corroborates the numerical, experimental and theoretical findings and shows that various plaque caps buckle in vivo. By displacing the sites of high stresses in the plaque cap, buckling may explain the atherosclerotic plaque cap rupture at various locations, including cap shoulders. Copyright © 2013 Elsevier Ltd. All rights reserved.

  4. Curcumin and endometriosis: Review on potential roles and molecular mechanisms.

    Science.gov (United States)

    Arablou, Tahereh; Kolahdouz-Mohammadi, Roya

    2018-01-01

    Endometriosis, an estrogen-dependent inflammatory disease, is one of the most common chronic gynecological disorders affecting women in reproductive age. It is characterized by the presence of endometrial-like tissue outside the uterus. The exact pathophysiology of endometriosis is not still well-known, but the immune system and inflammation have been considered as pivotal factors in disease progression. Turmeric, an important spice all around the world, is obtained from the rhizomes of Curcuma longa, a member of the Zingiberaceae family. It has been used in the prevention and treatment of many diseases since ancient times. Curcumin is the principal polyphenol isolated from turmeric. Several evidences have shown the anti-inflammatory, antioxidant, anti-tumor, anti-angiogenesis, and anti-metastatic activities of curcumin. In this review, relevant articles on the effect of curcumin on endometriosis and possible molecular mechanisms are discussed. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

  5. Plant effects on soil denitrification - a review of potential mechanisms

    Science.gov (United States)

    Malique, Francois; Butterbach-Bahl, Klaus; Dannenmann, Michael

    2017-04-01

    Denitrification is a microbial process occurring in soils, both producing and consuming the potent greenhouse gas nitrous oxide (NO), competing for nitrate with plants and hydrological leaching pathways, removing nutrients and reactive nitrogen from the biosphere, and closing the global nitrogen cycle. Despite its obvious importance, denitrification remained among the least well quantified biogeochemical processes in soils. This is due to enormous methodological difficulties involved in the direct quantification of soil microbial denitrification rates (mainly with regard to the terminal product N2) and the denitrification nitrogen gas product ratios (NO:N2O:N2), Plants may affect denitrification through a myriad of mechanisms such as e.g., competition for nitrate and water, through oxygen consumption, by regulating litter quality and changing soil pH, and via the exudation of labile carbon or secondary plant compounds involved in shaping the rhizospheric microbial community. However, plant effects on denitrification so far hardly were quantified so that the actual extent of plant control on denitrification is largely unknown. Here, we summarize the current knowledge on mechanisms how plants can affect denitrification rates and N gas product ratios in soils at temporal scales from hours to days and years. We review earlier research to quantify plant effects on denitrification as well as critically discuss the limited methods currently available to quantify plant-soil-denitrifier interactions. Finally, we provide pointers to use plants as tools to manage denitrification, e.g. to improve N use efficiency in agricultural ecosystems and to minimize soil nitrous oxide emissions.

  6. Adolescent Anabolic/Androgenic Steroids: Aggression and Anxiety During Exposure Predict Behavioral Responding During Withdrawal in Syrian Hamsters (Mesocricetus auratus)

    OpenAIRE

    Ricci, Lesley A.; Morrison, Thomas R.; Melloni, Richard H.

    2013-01-01

    In the U.S. and worldwide anabolic/androgenic steroid use remains high in the adolescent population. This is concerning given that anabolic/androgenic steroid use is associated with a higher incidence of aggressive behavior during exposure and anxiety during withdrawal. This study uses pubertal Syrian hamsters (Mesocricetus auratus) to investigate the hypothesis that an inverse behavioral relationship exists between anabolic/androgenic steroid-induced aggression and anxiety across adolescent ...

  7. Changes of ploidy and sexuality status of "Carassius auratus" populations in the drainage area of the River Dyje (Czech Republic)

    Czech Academy of Sciences Publication Activity Database

    Lusková, Věra; Halačka, Karel; Vetešník, Lukáš; Lusk, Stanislav

    2004-01-01

    Roč. 4, č. 2 (2004), s. 165-171 ISSN 1642-3593. [International Symposium on the Ecology of Fluvial Fishes /9./. Lodz, 23.06.2003-26.06.2003] R&D Projects: GA ČR GA206/00/0668; GA AV ČR IBS5045111 Institutional research plan: CEZ:AV0Z6093917 Keywords : Carassius auratus * goldfish * ploidy status Subject RIV: EH - Ecology, Behaviour

  8. Morphometric characteristics and growth of Carassius auratus in the lower part of the River Dyje (Czech Republic)

    Czech Academy of Sciences Publication Activity Database

    Vetešník, Lukáš; Lusk, Stanislav; Halačka, Karel; Spurný, P.

    2004-01-01

    Roč. 4, č. 2 (2004), s. 215-221 ISSN 1642-3593. [International Symposium on the Ecology of Fluvial Fishes /9./. Lodz, 23.06.2003-26.06.2003] R&D Projects: GA ČR GA206/00/0668; GA AV ČR IBS5045111; GA AV ČR KSK6005114 Institutional research plan: CEZ:AV0Z6093917 Keywords : Carassius auratus * ploidy status Subject RIV: EG - Zoology

  9. The Effects of Calorie Restriction in Depression and Potential Mechanisms

    Science.gov (United States)

    Zhang, Yifan; Liu, Changhong; Zhao, Yinghao; Zhang, Xingyi; Li, Bingjin; Cui, Ranji

    2015-01-01

    Depression, also called major depressive disorder, is a neuropsychiatric disorder jeopardizing an increasing number of the population worldwide. To date, a large number of studies have devoted great attention to this problematic condition and raised several hypotheses of depression. Based on these theories, many antidepressant drugs were developed for the treatment of depression. Yet, the depressed patients are often refractory to the antidepressant therapies. Recently, increasing experimental evidences demonstrated the effects of calorie restriction in neuroendocrine system and in depression. Both basic and clinical investigations indicated that short-term calorie restriction might induce an antidepressant efficacy in depression, providing a novel avenue for treatment. Molecular basis underlying the antidepressant actions of calorie restriction might involve multiple physiological processes, primarily including orexin signaling activation, increased CREB phosphorylation and neurotrophic effects, release of endorphin and ketone production. However, the effects of chronic calorie restriction were quite controversial, in the cases that it often resulted in the long-term detrimental effects via inhibiting the function of 5-HT system and decreasing leptin levels. Here we review such dual effects of calorie restriction in depression and potential molecular basis behind these effects, especially focusing on antidepressant effects. PMID:26412073

  10. Potential mechanism for Calvados-related oesophageal cancer.

    Science.gov (United States)

    Linderborg, Klas; Joly, Jean Pierre; Visapää, Jukka-Pekka; Salaspuro, Mikko

    2008-02-01

    The old Normandian habit of consumption of hot Calvados is associated with an increased risk of oesophageal cancer compared to other alcoholic beverages. The role of alcohol consumption in the risk of oesophageal cancer is well established. The first metabolite of alcohol, acetaldehyde is a potential local carcinogen in humans. Accordingly, different acetaldehyde concentrations in different beverages could account for some of the variations in cancer risk with regard to the type of alcoholic beverage. Eighteen samples of farm-made Calvados were collected in Normandy. Samples of commercially available beverages were purchased, including factory-made Calvados, other spirits, wines, beer and cider. The samples were analysed gas-chromatically for acetaldehyde and ethanol concentrations. All results are expressed as mean+/-SD. The mean acetaldehyde concentration of all Calvados samples (1781+/-861 microM, n =25) differed highly significantly (pcognac had the highest mean acetaldehyde concentration of the measured beverages. The high concentration of acetaldehyde combined with possible effects of the high temperature at which Calvados is consumed could account for the increased risk of Calvados-related oesophageal cancer.

  11. Potentials of Industrie 4.0 and Machine Learning for Mechanical Joining

    OpenAIRE

    Jäckel, Mathias

    2017-01-01

    -Sensitivity analysis of the influence of component properties and joining parameters on the joining result for self-pierce riveting -Possibilities to link mechanical joining technologies with the automotive process chain for quality and flexibility improvements -Potential of using machine learning to reduce automotive product development cycles in relation to mechanical joining -Datamining for machine learning at mechanical joining

  12. Neural mechanisms of individual and sexual recognition in Syrian hamsters (Mesocricetus auratus).

    Science.gov (United States)

    Petrulis, Aras

    2009-06-25

    Recognizing the individual and sexual identities of conspecifics is critical for adaptive social behavior and, in most mammals this information is communicated primarily by chemosensory cues. Due to its heavy reliance on odor cues, we have used the Syrian hamster as our model species for investigating the neural regulation of social recognition. Using lesion, electrophysiological and immunocytochemical techniques, separate neural pathways underlying recognition of individual odors and guidance of sex-typical responses to opposite-sex odors have been identified in both male and female hamsters. Specifically, we have found that recognition of individual odor identity requires olfactory bulb connections to entorhinal cortex (ENT) rather than other chemoreceptive brain regions. This kind of social memory does not appear to require the hippocampus and may, instead, depend on ENT connections with piriform cortex. In contrast, sexual recognition, through either differential investigation or scent marking toward opposite-sex odors, depends on both olfactory and vomeronasal system input to the corticomedial amygdala. Preference for investigating opposite-sex odors requires primarily olfactory input to the medial amygdala (ME) whereas appropriately targeted scent marking responses require vomeronasal input to ME as well as to other structures. Within the ME, the anterior section (MEa) appears important for evaluating or classifying social odors whereas the posterodorsal region (MEpd) may be more involved in generating approach to social odors. Evidence is presented that analysis of social odors may initially be done in MEa and then communicated to MEpd, perhaps through micro-circuits that separately process male and female odors.

  13. Waterborne gemfibrozil challenges the hepatic antioxidant defense system and down-regulates peroxisome proliferator-activated receptor beta (PPARβ) mRNA levels in male goldfish (Carassius auratus)

    International Nuclear Information System (INIS)

    Mimeault, C.; Trudeau, V.L.; Moon, T.W.

    2006-01-01

    The lipid regulator gemfibrozil (GEM) is one of many human pharmaceuticals found in the aquatic environment. We previously demonstrated that GEM bioconcentrates in blood and reduces plasma testosterone levels in goldfish (Carassius auratus). In this study, we address the potential of an environmentally relevant waterborne concentration of GEM (1.5 μg/l) to induce oxidative stress in goldfish liver and whether this may be linked to GEM acting as a peroxisome proliferator (PP). We also investigate the autoregulation of the peroxisome proliferator-activated receptors (PPARs) as a potential index of exposure. The three PPAR subtypes (α, β, and γ) were amplified from goldfish liver cDNA. Goldfish exposed to a concentration higher (1500 μg/l) than environmentally relevant for 14 and 28 days significantly reduce hepatic PPARβ mRNA levels (p < 0.001). Levels of CYP1A1 mRNA were unchanged. GEM exposure significantly induced the antioxidant defense enzymes catalase (p < 0.001), glutathione peroxidase (p < 0.001) and glutathione-S-transferase (p = 0.006) but not acyl-CoA oxidase or glutathione reductase. As GEM exposure failed to increase levels of thiobarbituric reactive substances (TBARS), we conclude that a sub-chronic exposure to GEM upregulates the antioxidant defense status of the goldfish as an adaptive response to this human pharmaceutical

  14. MECHANISMS OF GROWTH AND TRANSFORMATION OF HUMAN AND INTELLECTUAL POTENTIALS IN CORPORATION OF KNOWLEDGE ECONOMY

    OpenAIRE

    Lanskaya D. V.

    2013-01-01

    The article considers the mechanisms of growth, transformation of human and intellectual potentials in the corporation capitals, and also the mechanisms of fixing of their carriers in a corporation for the purpose of ensuring growth of competitive force of corporation of knowledge economy; in particular, we have investigated basic mechanisms of interaction of owners of human and intellectual capitals with a vertical of the economic power of corporation and the mechanism of an intellectual ren...

  15. Sialoglycoprotein Isolated from Eggs of Carassius auratus Ameliorates Osteoporosis: An Effect Associated with Regulation of the Wnt/β-Catenin Pathway in Rodents.

    Science.gov (United States)

    Wang, Fei; Wang, Yiming; Zhao, Yanlei; Zhan, Qiping; Yu, Peng; Wang, Jingfeng; Xue, Changhu

    2016-04-13

    In the current study, ovariectomized (OVX) rats and the senescence-accelerated mouse strain P6 (SAMP6) were employed to establish models of postmenopausal osteoporosis and senile osteoporosis, respectively. The effects of treatment with sialoglycoprotein isolated from the eggs of Carassius auratus (Ca-SGP) on these two types of osteoporosis were investigated in vivo. Results showed that Ca-SGP significantly increased bone mineral density, ameliorated trabecular bone microstructure, and improved bone biomechanical properties in both OVX rats and SAMP6. The osteogenesis related Wnt/β-catenin pathway was targeted to study the underlying mechanism of Ca-SGP activity. In postmenopausal osteoporosis, Ca-SGP suppressed the activation of Wnt/β-catenin signal via down-regulating the expression of key genes including LRP5, β-catenin, and Runx2, suggesting that overactive osteogenesis was controlled by Ca-SGP. The bone formation was sharply weakened in senile osteoporosis, whereas Ca-SGP treatment promoted osteoblast activity by stimulating the Wnt/β-catenin signal. In conclusion, Ca-SGP ameliorated these two types of osteoporosis by normalizing bone anabolism.

  16. Sialoglycoproteins prepared from the eggs of Carassius auratus prevent bone loss by inhibiting the NF-κB pathway in ovariectomized rats.

    Science.gov (United States)

    Xia, Guanghua; Wang, Jingfeng; Sun, Shuhong; Zhao, Yanlei; Wang, Yiming; Yu, Zhe; Wang, Shanshan; Xue, Changhu

    2016-02-01

    In this study, we investigated the improvement of osteoporosis by sialoglycoproteins isolated from the eggs of Carassius auratus (Ca-SGP) in ovariectomized rats. Ca-SGP was supplemented to ovariectomized Sprague-Dawley rats for 90 days. The results showed that Ca-SGP treatment remarkably prevented the reduction of bone mass, improved cancellous bone structure and biochemical properties. Ca-SGP also significantly decreased the serum contents of TRAP, Cath-K, MMP-9, DPD, CTX-1, Ca, and P. Mechanism investigation revealed that Ca-SGP significantly increased the OPG/RANKL ratio in mRNA expression, protein expression and serum content. Further research suggested that NF-κB signaling pathways were inhibited by suppressing the mRNA and protein expressions of NFATc1 and TRAF6, diminishing the mRNA expression and phosphorylation of NF-κB p65, three key transcription factors in NF-κB pathways. These results suggest that Ca-SGP can improve osteoporosis by inhibiting bone resorption via suppressing the activation of osteoclastogenesis related NF-κB pathways.

  17. Morphology and morphometric relationships of the sagitta of Diapterus auratus (Perciformes: Gerreidae from Veracruz, Mexico

    Directory of Open Access Journals (Sweden)

    Verónica Rivera Félix

    2013-03-01

    Full Text Available Sagittae otoliths are the most studied because of their morphological variability and size; the sagittae may also have valuable taxonomic use and for D. auratus has not yet been described. In the present study we present a morphological description of the sagitta otolith and an analysis of its correlation with various morphometric parameters. The biological material was captured with a beach seine in the coasts of Alvarado and Port of Veracruz, from November 2009 to June 2010. Sagittae were extracted, cleaned, photographed (SEM and optical, and measured. The analysis included the correlations between sagitta’s length and width, versus the fish standard length, height and weight, for a total of 449 fishes. The comparison between left and right sagitta showed no significant difference in both otolith length and width (t-tests, pLos otolitos sagitta son los más estudiados debido a su variabilidad morfológica y a su tamaño, sin embargo, los otolitos de D. auratus no han sido estudiados hasta el momento. En el presente estudio, se muestra una descripción completa de la morfología y un análisis morfométrico de diversas medidas. El análisis incluye las relaciones entre el ancho y largo de la sagitta contra la longitud cefálica, longitud estándar, altura y peso de 449 peces. El material biológico fue capturado con un chinchorro playero en las costas de Alvarado y el Puerto de Veracruz de noviembre 2009 a junio 2010. Las sagittae fueron extraídas, limpiadas, fotografiadas (SEM y ópticas y medidas. La comparación entre el otolito derecho e izquierdo no mostró diferencias significativas entre el ancho y largo (prueba de t, p<0.05 para cada sexo. El otolito derecho fue utilizado para las relaciones de las distintas medidas del otolito del pez y del otolito de hembras y machos; la prueba de Fisher (d.f. 161 and 143, p<0.001 no mostró diferencias significativas de las pendientes e intersecciones entre ellos. La relación longitud del otolito

  18. Persistence of experimental Rocio virus infection in the golden hamster (Mesocricetus auratus

    Directory of Open Access Journals (Sweden)

    Daniele Freitas Henriques

    2012-08-01

    Full Text Available Rocio virus (ROCV is an encephalitic flavivirus endemic to Brazil. Experimental flavivirus infections have previously demonstrated a persistent infection and, in this study, we investigated the persistence of ROCV infection in golden hamsters (Mesocricetus auratus. The hamsters were infected intraperitoneally with 9.8 LD50/0.02 mL of ROCV and later anaesthetised and sacrificed at various time points over a 120-day period to collect of blood, urine and organ samples. The viral titres were quantified by real-time-polymerase chain reaction (qRT-PCR. The specimens were used to infect Vero cells and ROCV antigens in the cells were detected by immunefluorescence assay. The levels of antibodies were determined by the haemagglutination inhibition technique. A histopathological examination was performed on the tissues by staining with haematoxylin-eosin and detecting viral antigens by immunohistochemistry (IHC. ROCV induced a strong immune response and was pathogenic in hamsters through neuroinvasion. ROCV was recovered from Vero cells exposed to samples from the viscera, brain, blood, serum and urine and was detected by qRT-PCR in the brain, liver and blood for three months after infection. ROCV induced histopathological changes and the expression of viral antigens, which were detected by IHC in the liver, kidney, lung and brain up to four months after infection. These findings show that ROCV is pathogenic to golden hamsters and has the capacity to cause persistent infection in animals after intraperitoneal infection.

  19. Effects of dietary antioxidant of tomato extract and lycopene on Carassius auratus and Xiphophorus maculatus

    Directory of Open Access Journals (Sweden)

    Cynthia Montoya M.

    2014-06-01

    Full Text Available Objective. Evaluate the effect on tegument pigmentation, survival, growth and antioxidant capacity in diets supplemented with tomato extract and lycopene as additives in experimental feed for Carassius auratus and Xiphophorus maculatus. Materials and methods. The additives were added in different concentrations to a basic diet. We performed beginning and an ending biometrics for 100% of the population in each bioassay. The growth and survival of organisms were evaluated. The antioxidant capacity was analyzed by ABTS assay, both in the tomato extract sample as well as in foods used in different bioassays. The concentration of lycopene was determined in food and liver and muscle samples of fish fed with it. Acquired pigmentation of fish was assessed through photographs analyzed with Adobe Photoshop®. The results were evaluated by analysis of variance, and when differences were found (p0.05 on pigmentation and growth of the organisms under the established experimental conditions was obtained. Significant differences in antioxidant capacity (p<0.05 were obtained in foods with added lycopene. Conclusions. The inclusion of lycopene or tomato extract in food for the organisms used is not recommended to improve pigmentation, but further studies are needed to demonstrate antioxidant effect.

  20. Composition of Gut Microbiota in the Gibel Carp (Carassius auratus gibelio) Varies with Host Development.

    Science.gov (United States)

    Li, Xinghao; Zhou, Li; Yu, Yuhe; Ni, Jiajia; Xu, Wenjie; Yan, Qingyun

    2017-07-01

    To understand how a bacteria-free fish gut ecosystem develops microbiota as the fish ages, we performed a 1-year study on the gut microbiota of hatchling gibel carp (Carassius auratus gibelio). Our results indicate that the gut microbial diversity increases significantly as the fish develop. The gut microbial community composition showed significant shifts corresponding to host age and appeared to shift at two time points despite consistent diet and environmental conditions, suggesting that some features of the gut microbial community may be determined by the host's development. Dietary and environmental changes also seem to cause significant shifts in the fish gut microbial community. This study revealed that the gut microbiota of gibel carp assemble into distinct communities at different times during the host's development and that this process is less affected by the surrounding environment than by the host diet and development. Community phylogenetic analyses based on the net relatedness index further showed that environmental filtering (host selection) deterministically governs the gut microbial community composition. More importantly, the influence of host-associated deterministic filtering tends to weaken significantly over the course of the host's development. However, further studies are needed to assess whether this host development-dependent shift in gut microbiota will still exist under different rearing strategies.

  1. Acute ammonia toxicity in crucian carp Carassius auratus and effects of taurine on hyperammonemia.

    Science.gov (United States)

    Ren, Qianyan; Li, Ming; Yuan, Lixia; Song, Meize; Xing, Xiaodan; Shi, Ge; Meng, Fanxing; Wang, Rixin

    2016-12-01

    The four experimental groups were carried out to test the response of crucian carp Carassius auratus to ammonia toxicity and taurine: group 1 was injected with NaCl, group 2 was injected with ammonium acetate, group 3 was injected with ammonium acetate and taurine, and group 4 was injected with taurine. Fish in group 2 had the highest ammonia and glutamine contents, and the lowest glutamate content in liver and brain. Serum superoxide dismutase (SOD), glutathione (GSH) activities, red cell count (RBC), white cell count (WBC), lysozyme (LYZ) activity, complement C3 content of fish in group 2 reflected the lowest, but malondialdehyde content was the highest. Importantly, serum SOD and GSH activites, RBC, WBC, and LYZ activity, C3, C4 and total immunoglobulin contents of fish in group 3 were significantly higher than those of fish in group 2. This study indicates that ammonia exerts its toxic effects by interfering with amino acid transport, inducing ROS generation, leading to malondialdehyde accumulation and immunosuppression of crucian carp. The exogenous taurine could mitigate the adverse effect of high ammonia level on fish physiological disorder. Copyright © 2016 Elsevier Inc. All rights reserved.

  2. Cell proliferation and hair cell addition in the ear of the goldfish, Carassius auratus

    Science.gov (United States)

    Lanford, P. J.; Presson, J. C.; Popper, A. N.

    1996-01-01

    Cell proliferation and hair cell addition have not been studied in the ears of otophysan fish, a group of species who have specialized hearing capabilities. In this study we used the mitotic S-phase marker bromodeoxyuridine (BrdU) to identify proliferating cells in the ear of one otophysan species, Carassius auratus (the goldfish). Animals were sacrificed at 3 h or 5 days postinjection with BrdU and processed for immunocytochemistry. The results of the study show that cell proliferation occurs in all of the otic endorgans and results in the addition of new hair cells. BrdU-labeled cells were distributed throughout all epithelia, including the primary auditory endorgan (saccule), where hair cell phenotypes vary considerably along the rostrocaudal axis. This study lays the groundwork for our transmission electron microscopy study of proliferative cells in the goldfish ear (Presson et al., Hearing Research 100 (1996) 10-20) as well as future studies of hair cell development in this species. The ability to predict, based on epithelial location, the future phenotype of developing hair cells in the saccule of the goldfish make that endorgan a particularly powerful model system for the investigation of early hair cell differentiation.

  3. Comparative aspects of calcium dynamics in calcified tissues in the goldfish Carassius auratus

    International Nuclear Information System (INIS)

    Ichii, Taro; Mugiya, Yasuo

    1983-01-01

    The comparative nature of calcium physiology in bone, scales and otoliths was studied in young goldfish, Carassius auratus. Net calcium uptake by the fish was estimated to be 143 μg/g body weight/day. Of that, 79 % was distributed in bone, 13 % in scales, 3.5 % in otoliths and 4.5 % in soft tissues. Scales showed the highest incorporation of 45 Ca per mg-tissue weight after 1 or 2 days in 45 Ca-containing water; bone came second and otoliths last. However, 35 days after transfer to non-radioactive water, the order of descending radioactivity had changed to otoliths, bone and scales, reflecting different rates of calcium turnover. In bone, prelabeled 45 Ca activity increased for the first 2 days after transfer and then decreased gradually (biological half-life, Tsub(0.5) = 94 days). In otoliths, prelabeled radioactivity consistently increased for 35 days. Scales showed two phases of calcium turnover. They lost about 33 % of their prelabeled radioactivity during the first 7 days (Tsub(0.5) = 10.5 days) in non-radioactive water, but thereafter the rate of decrease slowed down greatly (Tsub(0.5) = 210 days). These two phases of calcium turnover were found in the osseous layer (including calcium crystals in the fibrillary plate) of scales, indicating the presence of physiologically labile as well as stable forms of calcium in the layer. (author)

  4. PATHOLOGICAL TISSUE LESIONS INDUCED BY CHRONIC CADMIUM INTOXICATION IN SILVER CRUCIAN CARP CARASSIUS AURATUS GIBELIO

    Directory of Open Access Journals (Sweden)

    NICULA MARIOARA

    2009-10-01

    Full Text Available The purpose of this work was to describe the histopathological effects of chronic cadmium intoxication on liver, gill, kidney, intestine and striated muscle in silver crucian carp Carassius auratus gibelio. 25 immature 1+-year-old crucian carp were obtained from a private fishfarm and acclimated to laboratory conditions. After a 21 days exposure to a sublethal cadmium concentration (1.625 ppm from a Cd (CH3COO2 x2H2O stock solution, liver, gill, kidney, small intestine and striated muscle were sampled and processed for histological examination. Histopathological alterations induced by studied heavy metal in the tissues of silver crucian carp specimenes were: nephrocite hypertrophic processes, distruction of intercellular jonctions, stratification of epitelium and congestions both in renal glomerulis and in interstitium; hyalinizations, congestions of blood vassels and vacuolations associated with lipid accumulation at the hepatic level; into intestinal mucosa revealed rich leucocyte infiltrates, with numerous leucocytes situated intraepithelial; branchial lamelles with disordered aspect and multilayered epithelium, vascular ectasias and leucocyte infiltrates into subepithelial connective tissue at the gill level; miolisis processes in peripheral muscular fibers manifested by contractile apparatus alteration on large areas.

  5. Benzocaína e eugenol como anestésicos para o quinguio (Carassius auratus

    Directory of Open Access Journals (Sweden)

    F. Bittencourt

    2012-12-01

    Full Text Available Avaliaram-se os tempos de indução e recuperação de quinguios (Carassius auratus expostos a dois anestésicos, eugenol e benzocaína. Foram utilizados 128 juvenis com peso médio de 2,07±0,53g e comprimento total médio de 5,51±0,56cm. A benzocaína mostrou ser mais eficiente do que o eugenol em relação ao tempo, tanto para indução ao coma quanto para a recuperação à fuga e também no que diz respeito à sobrevivência. As doses de benzocaína com melhores resultados foram de 87,5 e 100mg.L-1. O eugenol proporcionou demora na indução e na recuperação dos animais, além de ter apresentado mortalidades quando as doses anestésicas foram elevadas.

  6. Mathematical modelling of nutrient balance of a goldfish (Carassius auratus Linn. recirculating aquaculture system (GRAS

    Directory of Open Access Journals (Sweden)

    Sudeep Puthravilakom Sadasivan Nair

    2010-08-01

    Full Text Available In the present study, a goldfish (Carassius auratus Linn. recirculating aquaculture system (GRAS has been developed. The GRAS consisted of a culture tank, a screen filter and a foam fractionator for removal of particulate and dissolved solids and a trickling filter for conversion of ammonium- and nitrite-nitrogen to relatively harmless nitrate-nitrogen. The culture of goldfish at a stocking density of 1.08 kg/m3 was continued for a period of two and half months. Based on mass balance analysis of ammonium- and nitrate-nitrogen and assuming the trickling filter to be a plug flow reactor, a model was formulated to determine the necessary recirculation flow rate at different times of culture for maintaining the major nutrients, viz., ammonium- and nitrate-nitrogen below their permissible limits. The model was calibrated and validated using the real time data obtained from the experimental run. The high values of coefficient of determination and low values of root mean square error show the effectiveness of the model.

  7. Imaging Action Potential in Single Mammalian Neurons by Tracking the Accompanying Sub-Nanometer Mechanical Motion.

    Science.gov (United States)

    Yang, Yunze; Liu, Xian-Wei; Wang, Hui; Yu, Hui; Guan, Yan; Wang, Shaopeng; Tao, Nongjian

    2018-03-28

    Action potentials in neurons have been studied traditionally by intracellular electrophysiological recordings and more recently by the fluorescence detection methods. Here we describe a label-free optical imaging method that can measure mechanical motion in single cells with a sub-nanometer detection limit. Using the method, we have observed sub-nanometer mechanical motion accompanying the action potential in single mammalian neurons by averaging the repeated action potential spikes. The shape and width of the transient displacement are similar to those of the electrically recorded action potential, but the amplitude varies from neuron to neuron, and from one region of a neuron to another, ranging from 0.2-0.4 nm. The work indicates that action potentials may be studied noninvasively in single mammalian neurons by label-free imaging of the accompanying sub-nanometer mechanical motion.

  8. Estimating the size of the potential market for the Kyoto flexibility mechanisms

    NARCIS (Netherlands)

    Zhang, Zhong Xiang

    1999-01-01

    The Kyoto Protocol incorporates emissions trading, joint implementation and the clean development mechanism to help Annex I countries to meet their Kyoto targets at a lower overall cost. This paper aims to estimate the size of the potential market for all three flexibility mechanisms under the Kyoto

  9. Potential mechanisms linking probiotics to diabetes: a narrative review of the literature

    OpenAIRE

    Miraghajani, Maryam; Dehsoukhteh, Somayeh Shahraki; Rafie, Nahid; Hamedani, Sahar Golpour; Sabihi, Sima; Ghiasvand, Reza

    2017-01-01

    ABSTRACT CONTEXT AND OBJECTIVE: Some studies have suggested a wide range of possible mechanisms through which probiotics may play a role in diabetes prevention and treatment. However, the underlying mechanisms are not fully understood. We conducted this study to review the potential mechanisms suggested for the effect of probiotics in diabetes. DESIGN AND SETTING: Narrative review conducted at the Food Security Research Center of Isfahan. METHODS: A search in the electronic databases ME...

  10. Nuclear Magnetic Shielding Constants from Quantum Mechanical/Molecular Mechanical Calculations Using Polarizable Embedding: Role of the Embedding Potential

    DEFF Research Database (Denmark)

    Steinmann, Casper; Olsen, Jógvan Magnus Haugaard; Kongsted, Jacob

    2014-01-01

    We present NMR shielding constants obtained through quantum mechanical/molecular mechanical (QM/MM) embedding calculations. Contrary to previous reports, we show that a relatively small QM region is sufficient, provided that a high-quality embedding potential is used. The calculated averaged NMR...... shielding constants of both acrolein and acetone solvated in water are based on a number of snapshots extracted from classical molecular dynamics simulations. We focus on the carbonyl chromophore in both molecules, which shows large solvation effects, and we study the convergence of shielding constants...

  11. The Double-Well Potential in Quantum Mechanics: A Simple, Numerically Exact Formulation

    Science.gov (United States)

    Jelic, V.; Marsiglio, F.

    2012-01-01

    The double-well potential is arguably one of the most important potentials in quantum mechanics, because the solution contains the notion of a state as a linear superposition of "classical" states, a concept which has become very important in quantum information theory. It is therefore desirable to have solutions to simple double-well potentials…

  12. Photoperiodic modulation of thyroid hormone receptor (TR-α), deiodinase-2 (Dio-2) and glucose transporters (GLUT 1 and GLUT 4) expression in testis of adult golden hamster, Mesocricetus auratus.

    Science.gov (United States)

    Verma, Rakesh; Haldar, Chandana

    2016-12-01

    Phenomenon of seasonal reproduction is being regulated by changes in day length or photoperiod. The molecular mechanism underlying the event of photoperiodic regulation of testis and thyroid functions along with glucose uptake transporters has never been reported for golden hamster, M. auratus. The present study was performed to investigate the effect of photoperiod on the expression of key thyroid hormone receptor (TR-α), deiodinase-2 (Dio-2) and glucose uptake transporters (GLUT-1 & GLUT-4) in testicular germ cell and Leydig cells, and its correlation with the testicular androgen receptor (AR), germ cell proliferation factor (PCNA) and cell survival factor (Bcl-2) in testis of adult golden hamster, Mesocricetus auratus. Hamsters were exposed to different photoperiodic regimes i.e. critical photoperiod (CP), short day (SD) and long day (LD) for 10weeks. LD induces upregulation of thyroidal and gonadal activity as evident by active thyroid gland and testicular histoarchitecture, peripheral total thyroid (tT3, tT4) and testosterone hormone profiles when compared with SD exposed hamsters. Further, LD increased the expression of testicular TR-α, Dio-2, GLUT-1, GLUT-4 along with testicular AR and glucose content thereby enhancing germ cell proliferation and survival as reflected by increased PCNA and Bcl-2 expression when compared to SD exposed hamsters. Thus, it can be suggested that testicular thyroid hormone status is being regulated by photoperiod and is possibly involved in seasonal adaptation to reproductive phenomenon of golden hamster. Copyright © 2016 Elsevier B.V. All rights reserved.

  13. Uptake and accumulation of mercury from dental amalgam in the common goldfish, Carassius auratus

    Energy Technology Data Exchange (ETDEWEB)

    Kennedy, C.J

    2003-03-01

    Exposure of fish to concentrations of dental amalgam typically found in waste discharge leads to mercury accumulation in tissues. - In this study, the bioavailability and accumulation of mercury from external environmental exposure to mixed, cured, milled, sieved and proportioned dental amalgam was examined in the common goldfish, Carassius auratus. Fish were exposed to dental amalgam (particle size range from <0.10 to 3.15 mm) in order to represent the particle size and distribution of that found within the typical dental office wastewater discharge stream. Experimental amalgam water loadings were 0 g/l, 0.5 g/l and 1 g/l in glass aquaria at 15 deg. C for 28 days. Fish tissues were sampled at 5 min and 28 days of exposure, and the liver, brain, muscle and whole body analyzed for total mercury using cold vapor atomic fluorescence spectroscopy. Mercury was found in several tissues examined and generally increased with exposure to higher amounts of dental amalgam. The highest levels were found in the whole body (17.68{+-}5.73 {mu}g/g) followed by the liver (0.80{+-}0.16 {mu}g/g) and muscle (0.47{+-}0.16 {mu}g/g). The lowest concentrations were seen in the brain (0.28{+-}0.19 {mu}g/g). Compared to controls, concentrations in the whole body, muscle and liver in fish exposed for 28 days to the highest concentration of amalgam were 200-, 233-, and 40-fold higher, respectively. This study shows that mercury from an environmental exposure to representative samples of dental amalgam typically found within the dental wastewater discharge stream is bioavailable to fish and may accumulate in internal tissues.

  14. Reproductive activity of the frog Dendrobates auratus Girard in captivity breeding

    Directory of Open Access Journals (Sweden)

    Romana Křížová

    2010-01-01

    Full Text Available Research of the reproduction activities of Dendrobates auratus Girard, 1855 is part of a broader ana­ly­sis of the problems encountered when keeping frogs from the family Dendrobatidae in captivity. The aim is to achieve an optimization of measures for successful breeding of these amphibians, for both the amateur hobbyist and conservationist alike. Due to the wide area they have colonized, many colour variations exist; the reproduction parameters of six differently coloured examples of the species were tracked. The collection of data happened in standardized conditions over two consecutive years (2007, 2008 and was aimed at measuring five indicators concerning reproduction, understanding of egg-laying dynamics during a year, measuring the risk of stock loss during different stages of development and determining if any differences existed between the different colour variations in these parameters. A noticable alternating cycle of rest and reproduction activities has been observed between equinoxes. In the harvest there were usually 5–10 eggs with an average incubation period of 10 days (8–18 at a temperature of 22 °C. The total duration of development was on average 74 days (64–103. The number of eggs in a harvest and the duration of incubation were statistically dif­fe­rent with the blue form between different observed periods. Total mortality rate during ontogenesis reached 10–53%, the highest losses were in the period when the tadpole left its egg and began developing its hind legs, 5–60%. The optimisation of breeding conditions has been reccommended. Secondary be­ne­fits of this study research was the collection of new knowledge about ethology of this species in captivity.

  15. Effects of carbofuran, diuron, and nicosulfuron on acetylcholinesterase activity in goldfish (Carassius auratus).

    Science.gov (United States)

    Bretaud, S; Toutant, J P; Saglio, P

    2000-10-01

    Juvenile goldfish (Carassius auratus) were exposed to three widely used pesticides; carbofuran, diuron, and nicosulfuron. Acetylcholinesterase (AChE) activity and molecular forms of AChE were first characterized in brain and skeletal muscle of unexposed fish. Skeletal muscle had higher AChE activity than brain (306 and 215 nmol/min/mg protein, respectively). In brain, four molecular forms of AChE were found: A12, G4, G2, and G1. In the muscle, three molecular forms were found A12, A8, and G2. AChE activity was then evaluated in both tissues of fish exposed to different concentration of pesticides (5, 50, and 500 microg/L) for 6, 12, 24, and 48 h. In brain, AChE activity was significantly inhibited during all the periods of exposure in response to 50 microg/L (19-28%) and 500 microg/L (85-87%) carbofuran. Such effect was observed in the muscle only at 500 microg/L (86-92%). Carbofuran had no effect on the distribution of molecular forms. Significant inhibitions (9-12%) of brain AChE activity were also observed in response to diuron and nicosulfuron at 500 microg/L during all periods of exposure and for 50 microg/L nicosulfuron after 24 and 48 h. This study pointed out short-term effects of exposure to sublethal concentrations of the three pesticides, ranging among different chemical families, on brain and muscle AChE in goldfish. Copyright 2000 Academic Press.

  16. The environmental regulation of maturation in goldfish, Carassius auratus: effects of various LED light spectra.

    Science.gov (United States)

    Shin, Hyun Suk; Habibi, Hamid R; Choi, Cheol Young

    2014-02-01

    While there have been a number of studies on the effects of photoperiod and duration of light and dark exposure, much less information is available on the importance of light intensity. This study investigated the effects of exposure of goldfish, Carassius auratus exposed to white fluorescent bulbs, and red (peak at 630nm), and green (530nm) light emitting diodes (LEDs) at approximately 0.9W/m(2) (12-h light:12-h dark) for four months on a number of hormones of the hypothalamus-pituitary-gonad (HPG) axis, in vivo and in vitro. We investigated the effects of native GnRH molecules (gonadotropin-releasing hormones; salmon GnRH, sGnRH; and chicken GnRH-II, cGnRH-II), gonadotropin hormones (GTHα; follicle-stimulating hormone, FSH-β; luteinizing hormone, LH-β2), kisspeptin 1 (Kiss1) and G protein-coupled receptor 54 (GPR54) mRNA levels. Furthermore, we measured LH and 17α-hydroxypregnenolone levels in plasma and we performed gonad histological observations. GnRHs, Kiss1, GPR54 and GTH mRNA and plasma LH and 17α-hydroxypregnenolone levels in the in vivo and in vitro groups exposed to green LEDs were significantly higher than the other groups. Histological analysis revealed the presence of oocytes in the yolk stage in fish exposed to green light. These results suggest that green wavelengths regulate the HPG axis and enhance sexual maturation in goldfish. Copyright © 2013 Elsevier Inc. All rights reserved.

  17. Hyperglycemia Augments the Adipogenic Transdifferentiation Potential of Tenocytes and Is Alleviated by Cyclic Mechanical Stretch.

    Science.gov (United States)

    Wu, Yu-Fu; Huang, Yu-Ting; Wang, Hsing-Kuo; Yao, Chung-Chen Jane; Sun, Jui-Sheng; Chao, Yuan-Hung

    2017-12-28

    Diabetes mellitus is associated with damage to tendons, which may result from cellular dysfunction in response to a hyperglycemic environment. Tenocytes express diminished levels of tendon-associated genes under hyperglycemic conditions. In contrast, mechanical stretch enhances tenogenic differentiation. However, whether hyperglycemia increases the non-tenogenic differentiation potential of tenocytes and whether this can be mitigated by mechanical stretch remains elusive. We explored the in vitro effects of high glucose and mechanical stretch on rat primary tenocytes. Specifically, non-tenogenic gene expression, adipogenic potential, cell migration rate, filamentous actin expression, and the activation of signaling pathways were analyzed in tenocytes treated with high glucose, followed by the presence or absence of mechanical stretch. We analyzed tenocyte phenotype in vivo by immunohistochemistry using an STZ (streptozotocin)-induced long-term diabetic mouse model. High glucose-treated tenocytes expressed higher levels of the adipogenic transcription factors PPAR γ and C/EBPs. PPARγ was also highly expressed in diabetic tendons. In addition, increased adipogenic differentiation and decreased cell migration induced by high glucose implicated a fibroblast-to-adipocyte phenotypic change. By applying mechanical stretch to tenocytes in high-glucose conditions, adipogenic differentiation was repressed, while cell motility was enhanced, and fibroblastic morphology and gene expression profiles were strengthened. In part, these effects resulted from a stretch-induced activation of ERK (extracellular signal-regulated kinases) and a concomitant inactivation of Akt. Our results show that mechanical stretch alleviates the augmented adipogenic transdifferentiation potential of high glucose-treated tenocytes and helps maintain their fibroblastic characteristics. The alterations induced by high glucose highlight possible pathological mechanisms for diabetic tendinopathy

  18. Calcium handling in Sparus auratus: effects of water and dietary calcium levels on mineral composition, cortisol and PTHrP levels.

    NARCIS (Netherlands)

    Abbink, W.; Bevelander, G.S.; Rotllant, J.; Canario, A.V.; Flik, G.

    2004-01-01

    Juvenile gilthead sea bream (Sparus auratus L.; 10-40 g body mass) were acclimatized in the laboratory to full strength (34 per thousand) or dilute (2.5 per thousand) seawater and fed normal, calcium-sufficient or calcium-deficient diet for nine weeks. Mean growth rate, whole-body calcium and

  19. Physiological and condition-related traits in the gynogenetic-sexual Carassius auratus complex: different investments promoting the coexistence of two reproductive forms?

    Czech Academy of Sciences Publication Activity Database

    Šimková, A.; Hyršl, P.; Halačka, Karel; Vetešník, Lukáš

    2015-01-01

    Roč. 15, č. 154 (2015), s. 154 ISSN 1471-2148 R&D Projects: GA ČR GAP505/12/0375 Institutional support: RVO:68081766 Keywords : Carassius auratus * gene expression * growth Subject RIV: EG - Zoology Impact factor: 3.406, year: 2015

  20. Peroral Echinococcus multilocularis egg inoculation in Myodes glareolus, Mesocricetus auratus and Mus musculus (CD-1 IGS and C57BL/6j)

    DEFF Research Database (Denmark)

    Woolsey, Ian David; Jensen, Per Moestrup; Deplazes, Peter

    2016-01-01

    Echinococcus multilocularis transmission predominantly occurs in Europe between the red fox (Vulpes vulpes) and various species of rodent intermediate hosts. We infected 3 species of rodent, Myodes glareolus (n = 47), Mesocricetus auratus (n = 11) and outbred Mus musculus (CD-1 IGS) (n = 9...

  1. Phenotypic and molecular variation in the green and black poison-dart frog Dendrobates auratus (Anura: Dendrobatidae from Costa Rica

    Directory of Open Access Journals (Sweden)

    Lisa D Patrick

    2009-11-01

    Full Text Available The green and black poison-dart frog Dendrobates auratus exhibits high intraspecific variation in hue color and pattern throughout its range, making it a very popular species in the pet trade. We analyzed the correspondence between color variation and molecular variation of D. auratus from Costa Rica using RAPD analysis. Twenty-six random primers were analyzed for variation in 99 individuals from seven populations. Color pattern was scored from digital images of the dorsal and ventral views. In general, frogs from the Caribbean coast had significantly more light coloration than black color but cannot be grouped by population based only on hue pattern. Only 3 RAPD primers were found to be polymorphic, representing a total of 16 loci. Most of the molecular variation encountered here occurs within populations, thus making unclear the degree of population structure and differentiation. Further examination of COI mtDNA sequences from our samples also supports these results. Partial Mantel correlations suggested that the pattern of molecular variation is not congruent with the variation in color pattern in this species, an outcome that is discussed in terms of phenotypic evolution. Rev. Biol. Trop. 57 (Suppl. 1: 313-321. Epub 2009 November 30.

  2. Models of intracellular mechanisms of plant bioelectrical potentials caused by combined stimulation

    Directory of Open Access Journals (Sweden)

    D. V. Chernetchenko

    2014-10-01

    Full Text Available This paper deals with bioelectrical potentials of the plants recorded during different types of stimuli and combined stimulus as well. All registrations were observed on the leaves of the corn. We used different stimuli, such as cold, heat, photo- and electrical stimulation, and certain combination of this stimuli. Hardware and software system for automated recording of bioelectrical potentials has been successfully used in this work. We proposed the universal pattern of bioelectrical potentials’ recording which allowed to detect the response of the biological object to different stimuli and various combinations of these stimuli. This pattern can be used for the deeper understanding of biological mechanisms of electrical potentials’ generation in cells and discovering of processes of accommodation of whole organisms to these stimuli. Integrated system of recording and biometrical processing was used for analysis of corn leaves electrical responses to the thermal stimuli. The dynamics of these potentials was studied, with the quantitative analysis of the potential level stabilization.We calculated the ratio of amplitude of response potentials to the first response amplitude. Mathematical models of the plant cell were used for studying of intracellular mechanisms of biopotentials gereration. As a result of modeling, we revealed that electrical response of the cells was based on selectiveconductivity of cell membrane for Н+ and Ca2+ ions. Therefore, we showed the biophysical relation of plant potentials to underlying intracellular biophysical mechanisms during thermal and combined stimulation.

  3. Exploring potential mechanisms of action of natalizumab in secondary progressive multiple sclerosis

    DEFF Research Database (Denmark)

    Sellebjerg, Finn; Cadavid, Diego; Steiner, Deborah

    2016-01-01

    progressive MS (SPMS), for which approved disease-modifying therapies are limited. In this review, we summarize the pathophysiological mechanisms involved in the development of SPMS and the rationale and clinical potential for natalizumab, which is currently approved for the treatment of relapsing forms of MS...

  4. Deciphering potential mechanisms of anaerobic soil disinfestation (ASD)-mediated control of Pratylenchus penetrans

    Science.gov (United States)

    Pratylenchus penetrans is a component of the apple replant disease (ARD) causal pathogen complex. The potential role for biological mechanisms contributing to ASD-mediated suppression of P. penetrans was examined in greenhouse study using orchard soil with a history of ARD. Populations of P. penetra...

  5. An empirical review of potential mediators and mechanisms of prolonged exposure therapy.

    Science.gov (United States)

    Cooper, Andrew A; Clifton, Erin G; Feeny, Norah C

    2017-08-01

    Prolonged exposure (PE) is an empirically-supported treatment for posttraumatic stress disorder (PTSD), but the precise mechanism(s) by which PE promotes symptom change are not well established. Understanding how PE works is critical to improving clinical outcomes, advancing dissemination efforts, and enhancing transdiagnostic models of psychopathology. However, mechanisms research conducted in clinical treatment settings is complex, and findings may be difficult to interpret without appropriate context. This is the first review of potential mechanisms of PE to provide such context, by rigorously evaluating empirical findings in line with essential criteria for effective research on mechanisms (or mediators). We begin by describing six putative mechanisms identified by emotional processing theory and contemporary models of fear extinction, before thoroughly reviewing empirical findings from clinical research on PE and similar PTSD treatments. We provide a detailed description of each study and mechanism test, as well as ratings of strength of evidence and quality of evaluation based on a novel rating scheme. We highlight variables with strong evidence (belief change and between-session habituation), intermediate evidence (inhibitory learning and emotional engagement), and minimal support (narrative organization and within-session habituation). After discussing limitations of the extant literature and this review, we summarize specific challenges for research on PE mechanisms and highlight directions for future study based on clinical and research implications. Copyright © 2017 Elsevier Ltd. All rights reserved.

  6. Mechanical strain promotes osteoblast ECM formation and improves its osteoinductive potential

    Directory of Open Access Journals (Sweden)

    Guo Yong

    2012-10-01

    Full Text Available Abstract Background The extracellular matrix (ECM provides a supportive microenvironment for cells, which is suitable as a tissue engineering scaffold. Mechanical stimulus plays a significant role in the fate of osteoblast, suggesting that it regulates ECM formation. Therefore, we investigated the influence of mechanical stimulus on ECM formation and bioactivity. Methods Mouse osteoblastic MC3T3-E1 cells were cultured in cell culture dishes and stimulated with mechanical tensile strain. After removing the cells, the ECMs coated on dishes were prepared. The ECM protein and calcium were assayed and MC3T3-E1 cells were re-seeded on the ECM-coated dishes to assess osteoinductive potential of the ECM. Results The cyclic tensile strain increased collagen, bone morphogenetic protein 2 (BMP-2, BMP-4, and calcium levels in the ECM. Compared with the ECM produced by unstrained osteoblasts, those of mechanically stimulated osteoblasts promoted alkaline phosphatase activity, elevated BMP-2 and osteopontin levels and mRNA levels of runt-related transcriptional factor 2 (Runx2 and osteocalcin (OCN, and increased secreted calcium of the re-seeded MC3T3-E1 cells. Conclusion Mechanical strain promoted ECM production of osteoblasts in vitro, increased BMP-2/4 levels, and improved osteoinductive potential of the ECM. This study provided a novel method to enhance bioactivity of bone ECM in vitro via mechanical strain to osteoblasts.

  7. Comparative antioxidant status in freshwater fish Carassius auratus exposed to six current-use brominated flame retardants: A combined experimental and theoretical study

    International Nuclear Information System (INIS)

    Feng, Mingbao; Qu, Ruijuan; Wang, Chao; Wang, Liansheng; Wang, Zunyao

    2013-01-01

    Highlights: •A combined experimental and theoretical approach was used for risk assessments of six BFRs in fish. •Oxidative stress biomarkers were measured for toxicity identification. •Toxicity order was proposed via the integrated biomarker response. •Theoretical calculations were performed to analyze the BFRs toxicity. -- Abstract: Decabromodiphenyl ether (BDE-209) and several non-polybrominated diphenyl ether (PBDE) brominated flame retardants (BFRs), such as tetrabromobisphenol A (TBBPA), hexabromocyclododecane (HBCD), decabromodiphenyl ethane (DBDPE), hexabromobenzene (HBB) and pentabromotoluene (PBT), are persistent halogenated contaminants ubiquitously detected in aquatic systems. However, data on comparative toxicological effects of these BFRs are lacking for fish. In this study, a combined experimental and theoretical approach was used to compare and analyze the effects of these BFRs on biochemical biomarkers in liver of Carassius auratus injected intraperitoneally with different doses (10 and 100 mg/kg) for 7, 14 and 30 days. Oxidative stress was evoked evidently for the prolonged exposure, represented by the significantly altered indices (superoxide dismutase, catalase, glutathione peroxidase, reduced glutathione, and malondialdehyde). The integrated biomarker response (IBR) index ranked biotoxicity as: PBT > HBB > HBCD > TBBPA > BDE-209 > DBDPE. Quantum chemical calculations (electronic parameters, frontier molecular orbitals, and Wiberg bond order) were performed for theoretical analysis. Notably, some descriptors were correlated with the toxicity order, probably implying the existence of a potential structure–activity relationship when more BFRs were included. Besides, theoretical calculations also provided some valuable information regarding the molecular characteristics and metabolic pathways of these current-use BFRs, which may facilitate the understanding on their environmental behavior and fate. Overall, this study adopted a combined

  8. Comparative antioxidant status in freshwater fish Carassius auratus exposed to six current-use brominated flame retardants: A combined experimental and theoretical study

    Energy Technology Data Exchange (ETDEWEB)

    Feng, Mingbao; Qu, Ruijuan; Wang, Chao; Wang, Liansheng; Wang, Zunyao, E-mail: wangzun315cn@163.com

    2013-09-15

    Highlights: •A combined experimental and theoretical approach was used for risk assessments of six BFRs in fish. •Oxidative stress biomarkers were measured for toxicity identification. •Toxicity order was proposed via the integrated biomarker response. •Theoretical calculations were performed to analyze the BFRs toxicity. -- Abstract: Decabromodiphenyl ether (BDE-209) and several non-polybrominated diphenyl ether (PBDE) brominated flame retardants (BFRs), such as tetrabromobisphenol A (TBBPA), hexabromocyclododecane (HBCD), decabromodiphenyl ethane (DBDPE), hexabromobenzene (HBB) and pentabromotoluene (PBT), are persistent halogenated contaminants ubiquitously detected in aquatic systems. However, data on comparative toxicological effects of these BFRs are lacking for fish. In this study, a combined experimental and theoretical approach was used to compare and analyze the effects of these BFRs on biochemical biomarkers in liver of Carassius auratus injected intraperitoneally with different doses (10 and 100 mg/kg) for 7, 14 and 30 days. Oxidative stress was evoked evidently for the prolonged exposure, represented by the significantly altered indices (superoxide dismutase, catalase, glutathione peroxidase, reduced glutathione, and malondialdehyde). The integrated biomarker response (IBR) index ranked biotoxicity as: PBT > HBB > HBCD > TBBPA > BDE-209 > DBDPE. Quantum chemical calculations (electronic parameters, frontier molecular orbitals, and Wiberg bond order) were performed for theoretical analysis. Notably, some descriptors were correlated with the toxicity order, probably implying the existence of a potential structure–activity relationship when more BFRs were included. Besides, theoretical calculations also provided some valuable information regarding the molecular characteristics and metabolic pathways of these current-use BFRs, which may facilitate the understanding on their environmental behavior and fate. Overall, this study adopted a combined

  9. Rac1 in human diseases: The therapeutic potential of targeting Rac1 signaling regulatory mechanisms.

    Science.gov (United States)

    Marei, Hadir; Malliri, Angeliki

    2017-07-03

    Abnormal Rac1 signaling is linked to a number of debilitating human diseases, including cancer, cardiovascular diseases and neurodegenerative disorders. As such, Rac1 represents an attractive therapeutic target, yet the search for effective Rac1 inhibitors is still underway. Given the adverse effects associated with Rac1 signaling perturbation, cells have evolved several mechanisms to ensure the tight regulation of Rac1 signaling. Thus, characterizing these mechanisms can provide invaluable information regarding major cellular events that lead to aberrant Rac1 signaling. Importantly, this information can be utilized to further facilitate the development of effective pharmacological modulators that can restore normal Rac1 signaling. In this review, we focus on the pathological role of Rac1 signaling, highlighting the benefits and potential drawbacks of targeting Rac1 in a clinical setting. Additionally, we provide an overview of available compounds that target key Rac1 regulatory mechanisms and discuss future therapeutic avenues arising from our understanding of these mechanisms.

  10. Swim bladder function and buoyancy control in pink snapper (Pagrus auratus) and mulloway (Argyrosomus japonicus).

    Science.gov (United States)

    Stewart, John; Hughes, Julian M

    2014-04-01

    Physoclist fish are able to regulate their buoyancy by secreting gas into their hydrostatic organ, the swim bladder, as they descend through the water column and by resorbing gas from their swim bladder as they ascend. Physoclists are restricted in their vertical movements due to increases in swim bladder gas volume that occur as a result of a reduction in hydrostatic pressure, causing fish to become positively buoyant and risking swim bladder rupture. Buoyancy control, rates of swim bladder gas exchange and restrictions to vertical movements are little understood in marine teleosts. We used custom-built hyperbaric chambers and laboratory experiments to examine these aspects of physiology for two important fishing target species in southern Australia, pink snapper (Pagrus auratus) and mulloway (Argyrosomus japonicus). The swim bladders of pink snapper and mulloway averaged 4.2 and 4.9 % of their total body volumes, respectively. The density of pink snapper was not significantly different to the density of seawater (1.026 g/ml), whereas mulloway were significantly denser than seawater. Pink snapper secreted gas into their swim bladders at a rate of 0.027 ± 0.005 ml/kg/min (mean ± SE), almost 4 times faster than mulloway (0.007 ± 0.001 ml/kg/min). Rates of swim bladder gas resorption were 11 and 6 times faster than the rates of gas secretion for pink snapper and mulloway, respectively. Pink snapper resorbed swim bladder gas at a rate of 0.309 ± 0.069 ml/kg/min, 7 times faster than mulloway (0.044 ± 0.009 ml/kg/min). Rates of gas exchange were not affected by water pressure or water temperature over the ranges examined in either species. Pink snapper were able to acclimate to changes in hydrostatic pressure reasonably quickly when compared to other marine teleosts, taking approximately 27 h to refill their swim bladders from empty. Mulloway were able to acclimate at a much slower rate, taking approximately 99 h to refill their swim bladders. We estimated that the

  11. Dynamic Action Potential Restitution Contributes to Mechanical Restitution in Right Ventricular Myocytes From Pulmonary Hypertensive Rats.

    Science.gov (United States)

    Hardy, Matthew E L; Pervolaraki, Eleftheria; Bernus, Olivier; White, Ed

    2018-01-01

    We investigated the steepened dynamic action potential duration (APD) restitution of rats with pulmonary artery hypertension (PAH) and right ventricular (RV) failure and tested whether the observed APD restitution properties were responsible for negative mechanical restitution in these myocytes. PAH and RV failure were provoked in male Wistar rats by a single injection of monocrotaline (MCT) and compared with saline-injected animals (CON). Action potentials were recorded from isolated RV myocytes at stimulation frequencies between 1 and 9 Hz. Action potential waveforms recorded at 1 Hz were used as voltage clamp profiles (action potential clamp) at stimulation frequencies between 1 and 7 Hz to evoke rate-dependent currents. Voltage clamp profiles mimicking typical CON and MCT APD restitution were applied and cell shortening simultaneously monitored. Compared with CON myocytes, MCT myocytes were hypertrophied; had less polarized diastolic membrane potentials; had action potentials that were triggered by decreased positive current density and shortened by decreased negative current density; APD was longer and APD restitution steeper. APD90 restitution was unchanged by exposure to the late Na + -channel blocker (5 μM) ranolazine or the intracellular Ca 2+ buffer BAPTA. Under AP clamp, stimulation frequency-dependent inward currents were smaller in MCT myocytes and were abolished by BAPTA. In MCT myocytes, increasing stimulation frequency decreased contraction amplitude when depolarization duration was shortened, to mimic APD restitution, but not when depolarization duration was maintained. We present new evidence that the membrane potential of PAH myocytes is less stable than normal myocytes, being more easily perturbed by external currents. These observations can explain increased susceptibility to arrhythmias. We also present novel evidence that negative APD restitution is at least in part responsible for the negative mechanical restitution in PAH myocytes. Thus

  12. Potential mechanisms of phthalate ester embryotoxicity in the abalone Haliotis diversicolor supertexta

    Energy Technology Data Exchange (ETDEWEB)

    Zhou Jin [L-304, Life Sciences Division, Graduate School at Shenzhen, Tsinghua University, Shenzhen University Town, Xili, Shenzhen City 518055 (China); Cai Zhonghua, E-mail: caizh@sz.tsinghua.edu.cn [L-304, Life Sciences Division, Graduate School at Shenzhen, Tsinghua University, Shenzhen University Town, Xili, Shenzhen City 518055 (China); Key Laboratory of Aquatic-Ecology, Tianjin Agricultural University, Lishui Road 112, Tianjin 300384 (China); Xing Kezhi [Key Laboratory of Aquatic-Ecology, Tianjin Agricultural University, Lishui Road 112, Tianjin 300384 (China)

    2011-05-15

    The effects and associated toxicological mechanisms of five phthalate esters (PAEs) on abalone embryonic development were investigated by exposing the embryos to a range of PAEs concentrations (0.05, 0.2, 2 and 10 {mu}g/mL). The results showed that PAEs could significantly reduce embryo hatchability, increase developmental malformations, and suppress the metamorphosis of abalone larvae. The possible toxicological mechanisms of PAEs to abalone embryos included, affecting the Na{sup +}-K{sup +}-pump and Ca{sup 2+}-Mg{sup 2+}-pump activities, altering the peroxidase (POD) level and the malondialdehyde (MDA) production, damaging the extraembryonic membranes structure, as well as disrupting endocrine-related genes (gpx, cyp3a, and 17{beta}-hsd 12) expression properties. Taken together, this work showed that PAEs adversely affected the embryonic ontogeny of abalone. The abilities of PAEs affecting the osmoregulation, inducing oxidative stress, damaging embryo envelope structure, and causing physiological homeostasis disorder, are likely to be a part of the common mechanisms responsible for their embryonic toxicity. - Highlights: > PAEs affected abalone hatchability, morphogenesis and metamorphosis behavior. > The toxicity of the five PAEs to embryogenesis was ranked as DBP > DEP > DMP > DOP > DEHP. > The osmoregulation disorder and oxidative damage are the potential mechanisms. - Potential mechanisms of PAEs on abalone embryogenesis are osmoregulation disorder, oxidative damage and physiological dysfunction.

  13. Potential mechanisms linking probiotics to diabetes: a narrative review of the literature

    Directory of Open Access Journals (Sweden)

    Maryam Miraghajani

    Full Text Available ABSTRACT CONTEXT AND OBJECTIVE: Some studies have suggested a wide range of possible mechanisms through which probiotics may play a role in diabetes prevention and treatment. However, the underlying mechanisms are not fully understood. We conducted this study to review the potential mechanisms suggested for the effect of probiotics in diabetes. DESIGN AND SETTING: Narrative review conducted at the Food Security Research Center of Isfahan. METHODS: A search in the electronic databases MEDLINE (PubMed, Cochrane Library, Web of Science and Google scholar was performed up to October 2016. RESULTS: The initial search yielded 1214 reports. After removing duplicates, 704 titles and abstracts were screened. Finally, out of 83 full-text articles that were reviewed for eligibility, 30 articles were included in the final analysis. The anti-diabetic mechanisms for probiotics reported encompass intraluminal and direct effects on the intestinal mucosa and microbiota (n = 13, anti-inflammatory and immunomodulatory effects (n = 10, antioxidative effects (n = 5, effects on endoplasmic reticulum (ER stress and expression of genes involved in glucose homeostasis and insulin resistance (n = 6, with some studies pointing to more than one mechanism. CONCLUSION: The results may throw some light on the capacity of probiotics as a novel approach towards controlling diabetes. However, further human studies are warranted to elucidate and confirm the potential role of probiotics in diabetes prevention and treatment. Also, it needs to be ascertained whether the effectiveness of probiotics in diabetes prevention and treatment is dependent on the strain of the microorganisms.

  14. Preparation and ultrastructure of spermatozoa from green poison frogs, Dendrobates auratus, following hormonal induced spermiation (Amphibia, Anura, Dendrobatidae).

    Science.gov (United States)

    Lipke, Christian; Meinecke-Tillmann, Sabine; Meyer, Wilfried; Meinecke, Burkhard

    2009-07-01

    Few ultrastructural studies have been performed on members of the Dendrobatidae, although such investigations can be useful for the understanding of reproductive patterns, as a diagnostic method for males in breeding programs for endangered amphibians and for phylogenetic analysis. The sperm ultrastructure of the Green Poison Frog, Dendrobates auratus, from Panama is described following induced spermiation in living animals. To date only testicular spermatozoa in other dendrobatid frogs have been analysed. Moreover, an electron microscopic preparation method (transmission and scanning electron microscopy) for dendrobatid sperm cells in low concentration is presented. Sperm cells from stimulated frogs (100 IU human chorionic gonadotropin, hCG, twice at an interval of 1h) were recovered via cloaca lavage using 600 microl isotonic phosphate-free amphibian saline (IPS). Centrifuged flushings (5 min, 173 x g) were deposited on microscopic slides. Adherent spermatozoa were treated with Karnovsky fixative (overnight, 4 degrees C). After postfixation (2h, 1% osmium tetroxide), samples were dehydrated in series of ascending acetones (30-100%). For transmission electron microscopy sperm cells were encapsulated using Epon and 1.5% 2,4,6-tris(dimethylaminomethyl)phenol (DMP 30). Ultrathin sections (70 nm) were cut and stained with uranyl acetate (30 min) and lead citrate (5 min). Sperm cells are filiform with a 21.1+/-2.7 microm long and arcuated head and a single tail (35.0+/-4.2 microm length). Their acrosomal complex is located at the anterior portion of the head and consists of the acrosomal vesicle which has low electron density, and the subjacent electron-dense subacrosomal cone. In transverse section, the nucleus is circular (1.9+/-0.2 microm diameter) and conical in longitudinal section. It is surrounded by several groups of mitochondria. The chromatin is highly condensed and electron-dense but shows numerous electron-lucent inclusions. A short midpiece has a

  15. Motivation by potential gains and losses affects control processes via different mechanisms in the attentional network.

    Science.gov (United States)

    Paschke, Lena M; Walter, Henrik; Steimke, Rosa; Ludwig, Vera U; Gaschler, Robert; Schubert, Torsten; Stelzel, Christine

    2015-05-01

    Attentional control in demanding cognitive tasks can be improved by manipulating the motivational state. Motivation to obtain gains and motivation to avoid losses both usually result in faster reaction times and stronger activation in relevant brain areas such as the prefrontal cortex, but little is known about differences in the underlying neurocognitive mechanisms of these types of motivation in an attentional control context. In the present functional magnetic resonance imaging (fMRI) study, we tested whether potential gain and loss as motivating incentives lead to overlapping or distinct neural effects in the attentional network, and whether one of these conditions is more effective than the other. A Flanker task with word stimuli as targets and distracters was performed by 115 healthy participants. Using a mixed blocked and event-related design allowed us to investigate transient and sustained motivation-related effects. Participants could either gain money (potential gain) or avoid losing money (potential loss) in different task blocks. Participants showed a congruency effect with increased reaction times for incongruent compared to congruent trials. Potential gain led to generally faster responses compared to the neutral condition and to stronger improvements than potential loss. Potential loss also led to shorter response times compared to the neutral condition, but participants improved mainly during incongruent and not during congruent trials. The event-related fMRI data revealed a main effect of congruency with increased activity in the left inferior frontal gyrus (IFG) and inferior frontal junction area (IFJ), the pre-supplementary motor area (pre-SMA), bilateral insula, intraparietal sulcus (IPS) and visual word form area (VWFA). While potential gain led to increased activity in a cluster of the IFJ and the VWFA only during incongruent trials, potential loss was linked to activity increases in these regions during incongruent and congruent trials. The

  16. Music and Memory in Alzheimer's Disease and The Potential Underlying Mechanisms.

    Science.gov (United States)

    Peck, Katlyn J; Girard, Todd A; Russo, Frank A; Fiocco, Alexandra J

    2016-01-01

    With population aging and a projected exponential expansion of persons diagnosed with Alzheimer's disease (AD), the development of treatment and prevention programs has become a fervent area of research and discovery. A growing body of evidence suggests that music exposure can enhance memory and emotional function in persons with AD. However, there is a paucity of research that aims to identify specific underlying neural mechanisms associated with music's beneficial effects in this particular population. As such, this paper reviews existing anecdotal and empirical evidence related to the enhancing effects of music exposure on cognitive function and further provides a discussion on the potential underlying mechanisms that may explain music's beneficial effect. Specifically, this paper will outline the potential role of the dopaminergic system, the autonomic nervous system, and the default network in explaining how music may enhance memory function in persons with AD.

  17. Idiosyncratic Drug-Induced Liver Injury (IDILI: Potential Mechanisms and Predictive Assays

    Directory of Open Access Journals (Sweden)

    Alexander D. Roth

    2017-01-01

    Full Text Available Idiosyncratic drug-induced liver injury (IDILI is a significant source of drug recall and acute liver failure (ALF in the United States. While current drug development processes emphasize general toxicity and drug metabolizing enzyme- (DME- mediated toxicity, it has been challenging to develop comprehensive models for assessing complete idiosyncratic potential. In this review, we describe the enzymes and proteins that contain polymorphisms believed to contribute to IDILI, including ones that affect phase I and phase II metabolism, antioxidant enzymes, drug transporters, inflammation, and human leukocyte antigen (HLA. We then describe the various assays that have been developed to detect individual reactions focusing on each of the mechanisms described in the background. Finally, we examine current trends in developing comprehensive models for examining these mechanisms. There is an urgent need to develop a panel of multiparametric assays for diagnosing individual toxicity potential.

  18. Cellular and Molecular Mechanisms of Diabetic Atherosclerosis: Herbal Medicines as a Potential Therapeutic Approach

    Directory of Open Access Journals (Sweden)

    Jinfan Tian

    2017-01-01

    Full Text Available An increasing number of patients diagnosed with diabetes mellitus eventually develop severe coronary atherosclerosis disease. Both type 1 and type 2 diabetes mellitus increase the risk of cardiovascular disease associated with atherosclerosis. The cellular and molecular mechanisms affecting the incidence of diabetic atherosclerosis are still unclear, as are appropriate strategies for the prevention and treatment of diabetic atherosclerosis. In this review, we discuss progress in the study of herbs as potential therapeutic agents for diabetic atherosclerosis.

  19. [Emissions trading potential : a mechanism to meet sustainability requirements for developing countries

    International Nuclear Information System (INIS)

    Govendor, V.

    1998-01-01

    The objectives of the Clean Development Mechanism (CDM) (sustainable development, adaptation to negative impacts, achieving compliance by developed nations, emission reduction against a defined baseline), and potential mechanisms for managing the CDM were described. In effect, the CDM is a means to ensure cost efficient greenhouse gas emissions reductions. It is also a tool to promote sustainable development in developing countries. As for managing CDM, the mechanism must include equitable regional representation, and balanced representation between developed and developing nations. It was emphasized that the mandate must be clear and unambiguous, and should include clarification of eligible projects, liaison between agencies and COP/MOP, managing the adaptation fund, oversee allocations to adaptation projects, and audit 'certified emission reduction' (CER) certified by CDM agencies. CERs should be based on solid technical definition and should be carefully verified, and joint implementation (JI) and emission trading should be measured and assessed against common criteria

  20. BODY WEIGHT AS A DETERMINANT OF CLINICAL EVOLUTION IN HAMSTERS (Mesocricetus auratus INFECTED WITH Leishmania (Viannia panamensis

    Directory of Open Access Journals (Sweden)

    Angela Maria Gomez-Galindo

    2013-09-01

    Full Text Available SUMMARY The clinical outcome of infection with Leishmania species of the subgenus Viannia in hamster model (Mesocricetus auratus has shown to be different depending on experimental protocol. Body weight has been a relevant determinant of the clinical outcome of the infection in hamsters with visceral leishmaniasis but its importance as a clinical parameter in hamsters with cutaneous leishmaniasis is not known. In this study, the clinical evolution of infection with L. (V panamensis was evaluated in juvenile and adult male hamsters during 11 weeks by comparing clinical parameters such as attitude, temperature, respiratory rate, appearance of the stool, and body weight between infected and non-infected groups. Results showed that body weight decreased in adult hamsters after infection by L. (V panamensis; this observation supports the use of body weight as an additional parameter to define the management or treatment of cutaneous leishmaniasis in infected adult hamsters used as an animal experimental model for leishmaniasis.

  1. Seco-limonoid derived from Raputia heptaphylla promotes the control of cutaneous leishmaniasis in hamsters (Mesocricetus auratus).

    Science.gov (United States)

    Granados-Falla, Diana; Gomez-Galindo, Angela; Daza, Alejandro; Robledo, Sara; Coy-Barrera, Carlos; Cuca, Luis; Delgado, Gabriela

    2016-03-01

    The rational search of novel bioactive molecules against pathogens with immunomodulatory activity is presently one of the most significant approaches to discover and design new therapeutic agents for effective control of infectious diseases, such as the infection caused by Leishmania parasites. In the present study, we evaluated the therapeutic efficacy of the recently characterized immunomodulatory compound 11α,19β-dihydroxy-7-acetoxy-7-deoxoichangin, a seco-limonoid derived from the bark of Raputia heptaphylla (Pittier) using: (1) peritoneal macrophages and (2) Mesocricetus auratus hamsters infected with Leishmania (V.) panamensis and Leishmania (L.) amazonensis. We observed the ability of this seco-limonoid to induce the effective control of the parasite either in vitro [determining an effective concentration 50 (EC50) of 59 µ m at the infection model] and in vivo (inducing clinical improvement or even cure in infected animals treated compared with the groups of animals treated with vehicle solution or meglumine antimoniate).

  2. Occurrence and intensity of parasites in goldfish (Carassius auratus L. from Guilan province fish ponds, north Iran

    Directory of Open Access Journals (Sweden)

    Roohi Javad Daghigh

    2016-03-01

    Full Text Available In this survey 109 specimens of goldfish (Carassius auratus were collected from Guilan fish ponds during 2012-13. After recording biometric characteristics, common parasitology methods were used. In the present study 11 parasite species were recovered from goldfish. Parasitofauna consisted of two protozoans: Ichthyophthirius multifiliis and Trichodina sp.; one digenean trematodes: Diplostomum spathaceum; six monogenean trematodes: Dactylogyrus vastator, Dactylogyrus formosus, Dactylogyrus baueri, Dactylogyrus anchoratus and Gyrodactylus sp.; one crustacean: copepodid stage of Lernaea cyprinacea and one nematodes larvae. All the monogeneans found during the current study are considered new locality records for goldfish in Guilan province, Iran. Mean intensity of infection and abundances of parasite species (with prevalences >10% among seasons were tested by the Kruskal-Wallis test (KW, multiple comparisons and Conover-Inman test. Results have shown that monogeneans had the highest prevalence values (49.54% in goldfish in Guilan fish ponds.

  3. Promoting adaptive flood risk management: the role and potential of flood recovery mechanisms

    Directory of Open Access Journals (Sweden)

    Priest Sally J

    2016-01-01

    Full Text Available There is a high potential for recovery mechanisms to be used to incentivise the uptake of flood mitigation and loss reduction measures, undertake adaptation and promote community resilience. Indeed, creating a resilient response to flooding requires flood risk management approaches to be aligned and it needs to be ensured that recovery mechanisms to not provide disincentives for individuals and business to take proactive action to reduce risk. However, the degree to which it is desirable and effective for insurers and governments providing compensation to promote resilience and risk reduction depends upon how the cover or compensation is organised and the premiums which are charged. A review of international flood recovery mechanisms has been undertaken to identify firstly the types of schemes that exist and their characteristics. Analysis of existing instruments highlights that there are various potential approaches to encourage or require the uptake of flood mitigation and also discourage the construction of new development in high flood risk. However despite the presence of these instruments, those organising recovery mechanisms could be doing much more to incentivise increased resilience.

  4. Cadmium transfer and detoxification mechanisms in a soil-mulberry-silkworm system: phytoremediation potential.

    Science.gov (United States)

    Zhou, Lingyun; Zhao, Ye; Wang, Shuifeng

    2015-11-01

    Phytoremediation has been proven to be an environmentally sound alternative for the recovery of contaminated soils, and the economic profit that comes along with the process might stimulate its field use. This study investigated cadmium (Cd) transfer and detoxification mechanisms in a soil-mulberry-silkworm system to estimate the suitability of the mulberry and silkworm as an alternative method for the remediation of Cd-polluted soil; it also explored the underlying mechanisms regulating the trophic transfer of Cd. The results show that both the mulberry and silkworm have high Cd tolerance. The transfer factor suggests that the mulberry has high potential for Cd extraction from polluted soil. The subcellular distribution and chemical forms of Cd in mulberry leaves show that cell wall deposition and vacuolar compartmentalization play important role in Cd tolerance. In the presence of increasing Cd concentrations in silkworm food, detoxification mechanisms (excretion and homeostasis) were activated so that excess Cd was excreted in fecal balls, and metallothionein levels in the mid-gut, the posterior of the silk gland, and the fat body of silkworms were enhanced. And, the Cd concentrations in silk are at a low level, ranging from 0.02 to 0.21 mg kg(-1). Therefore, these mechanisms of detoxification can regulate Cd trophic transfer, and mulberry planting and silkworm breeding has high phytoremediation potential for Cd-contaminated soil.

  5. The Problems of Realizing the Innovative Potential of Science and Mechanisms for their Solution

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    Ianchenko Zinayida B.

    2017-06-01

    Full Text Available The aim of the article is revealing reasons for the low payoff of science in terms of the effectiveness of the research activity and demand for its results in economic spheres, identifying problems in the innovation activity of research institutions and reasons for their arising, searching for fundamental approaches to the development of a strategy and mechanisms for realization of the innovative potential of science to strengthen its position in the real sector. The study used general scientific methods, including: systems approach — to systematize the problems of the innovation activity of research institutions; methods of theoretical generalization — to study the theoretical principles of the scientific and innovation activity; methods of analysis and synthesis — to search for fundamental approaches to the development of mechanisms for realization of the innovative potential of science. The used concepts of scientific activity and innovations are generalized. The author’s definition of the term “innovation” is proposed. The main reasons of the minor impact of science on the economy are systematized, the mechanisms for their elimination are offered. Based on the comprehensive analysis of the reasons for losing by science its impact on the economy, the ways of realizing the innovative potential of science are improved. The results of the research can be used in reforming domestic scientific research institutions.

  6. Reproductive endocrine-disrupting effects of triclosan: Population exposure, present evidence and potential mechanisms

    International Nuclear Information System (INIS)

    Wang, Cai-Feng; Tian, Ying

    2015-01-01

    Triclosan has been used as a broad-spectrum antibacterial agent for over 40 years worldwide. Increasing reports indicate frequent detection and broad exposure to triclosan in the natural environment and the human body. Current laboratory studies in various species provide strong evidence for its disrupting effects on the endocrine system, especially reproductive hormones. Multiple modes of action have been suggested, including disrupting hormone metabolism, displacing hormones from hormone receptors and disrupting steroidogenic enzyme activity. Although epidemiological studies on its effects in humans are mostly negative but conflicting, which is typical of much of the early evidence on the toxicity of EDCs, overall, the evidence suggests that triclosan is an EDC. This article reviews human exposure to triclosan, describes the current evidence regarding its reproductive endocrine-disrupting effects, and discusses potential mechanisms to provide insights for further study on its endocrine-disrupting effects in humans. - Highlights: • Triclosan is widely detected in human urine, blood and breast milk. • Laboratory studies suggest reproductive endocrine-disrupting effects of triclosan. • Laboratory studies suggest estrogenic properties of triclosan. • There are three potential mechanisms regarding the estrogenic effect of triclosan. • Prospective epidemiological studies on vulnerable populations are needed. - This review summarizes current evidence on human exposure to triclosan, and its reproductive endocrine-disrupting effects and potential mechanisms.

  7. Ultrastructural patterns of secretory activity in poison cutaneous glands of larval and juvenile Dendrobates auratus (Amphibia, Anura).

    Science.gov (United States)

    Angel, R; Delfino, G; Parra, G J

    2003-01-01

    A transmission electron-microscope study has been performed on larval and juvenile skin of the Central American arrow-frog Dendrobates auratus to investigate early secretory processes and maturational changes in the serous (poison) glands. Poison biosynthesis involves the endoplasmic reticulum (both smooth and rough types), as well as Golgi stacks which release early serous product as secretory vesicles (or pre-granules). These vesicles contain fine-grained material, along with single electron-opaque bodies, spheroidal in shape, that accompany the grained product throughout its post-Gogian, maturational change. The first steps of this process involve condensation and lead to the formation of secretory granules with a glomerular-like substructure, resulting from a thick, random aggregation of rods (secretory granule subunits). Advanced maturational activity causes the loss of peculiar granule substructure: the dense bodies split into fragments, whereas the thick glomerular arrangement becomes looser, until the secretory product changes into a dispersed material. This ultrastructural study revealed biosynthesis and maturation processes in close sequence, suggesting the poison of D. auratus contains proteins and/or peptides as well as lipophilic compounds. Molecules of both these classes are known to perform several roles relevant to survival strategies in extant anurans. Furthermore, the ephemeral granules with a glomerular-like substructure detected in tadpoles and froglets exhibit the complex patterns of mature poisons in adult specimens of other anurans: Hylidae and related families. This agrees with current trends in the taxonomy of these advanced frogs and underlines the pertinence of an ontogenetic approach in investigating anuran phylogenesis.

  8. Chemical compounds from anthropogenic environment and immune evasion mechanisms: potential interactions

    Science.gov (United States)

    Kravchenko, Julia; Corsini, Emanuela; Williams, Marc A.; Decker, William; Manjili, Masoud H.; Otsuki, Takemi; Singh, Neetu; Al-Mulla, Faha; Al-Temaimi, Rabeah; Amedei, Amedeo; Colacci, Anna Maria; Vaccari, Monica; Mondello, Chiara; Scovassi, A. Ivana; Raju, Jayadev; Hamid, Roslida A.; Memeo, Lorenzo; Forte, Stefano; Roy, Rabindra; Woodrick, Jordan; Salem, Hosni K.; Ryan, Elizabeth P.; Brown, Dustin G.; Lowe, Leroy; Lyerly, H.Kim

    2015-01-01

    An increasing number of studies suggest an important role of host immunity as a barrier to tumor formation and progression. Complex mechanisms and multiple pathways are involved in evading innate and adaptive immune responses, with a broad spectrum of chemicals displaying the potential to adversely influence immunosurveillance. The evaluation of the cumulative effects of low-dose exposures from the occupational and natural environment, especially if multiple chemicals target the same gene(s) or pathway(s), is a challenge. We reviewed common environmental chemicals and discussed their potential effects on immunosurveillance. Our overarching objective was to review related signaling pathways influencing immune surveillance such as the pathways involving PI3K/Akt, chemokines, TGF-β, FAK, IGF-1, HIF-1α, IL-6, IL-1α, CTLA-4 and PD-1/PDL-1 could individually or collectively impact immunosurveillance. A number of chemicals that are common in the anthropogenic environment such as fungicides (maneb, fluoxastrobin and pyroclostrobin), herbicides (atrazine), insecticides (pyridaben and azamethiphos), the components of personal care products (triclosan and bisphenol A) and diethylhexylphthalate with pathways critical to tumor immunosurveillance. At this time, these chemicals are not recognized as human carcinogens; however, it is known that they these chemicalscan simultaneously persist in the environment and appear to have some potential interfere with the host immune response, therefore potentially contributing to promotion interacting with of immune evasion mechanisms, and promoting subsequent tumor growth and progression. PMID:26002081

  9. Perchlorate formation on Mars through surface radiolysis-initiated atmospheric chemistry: A potential mechanism

    Science.gov (United States)

    Wilson, Eric H.; Atreya, Sushil K.; Kaiser, Ralf I.; Mahaffy, Paul R.

    2016-08-01

    Recent observations of the Martian surface by the Phoenix lander and the Sample Analysis at Mars indicate the presence of perchlorate (ClO4-). The abundance and isotopic composition of these perchlorates suggest that the mechanisms responsible for their formation in the Martian environment may be unique in our solar system. With this in mind, we propose a potential mechanism for the production of Martian perchlorate: the radiolysis of the Martian surface by galactic cosmic rays, followed by the sublimation of chlorine oxides into the atmosphere and their subsequent synthesis to form perchloric acid (HClO4) in the atmosphere, and the surface deposition and subsequent mineralization of HClO4 in the regolith to form surface perchlorates. To evaluate the viability of this mechanism, we employ a one-dimensional chemical model, examining chlorine chemistry in the context of Martian atmospheric chemistry. Considering the chlorine oxide, OClO, we find that an OClO flux as low as 3.2 × 107 molecules cm-2 s-1 sublimated into the atmosphere from the surface could produce sufficient HClO4 to explain the perchlorate concentration on Mars, assuming an accumulation depth of 30 cm and integrated over the Amazonian period. Radiolysis provides an efficient pathway for the oxidation of chlorine, bypassing the efficient Cl/HCl recycling mechanism that characterizes HClO4 formation mechanisms proposed for the Earth but not Mars.

  10. How Do Corporate Governance Mechanisms Affect A Firm’s Potential For Bankruptcy?

    Directory of Open Access Journals (Sweden)

    Rhesa Theodorus Hanani

    2015-03-01

    Full Text Available The purpose of this thesis is to understand the effects of corporate governance mechanisms on the potential for bankruptcy. This study is done by utilizing the linear regression fixed effect vector decomposition model on 30 listed firms from the consumer goods sector of Indonesia Stock Exchange during the 2010-2012 periods. The results of the study indicate that: the board of commissioners’ independence and size of the commissioners’ board pose a significant positive effect on the potential for bankruptcy; the presence of an audit committee and the presence of a nomination and remuneration committee pose a significant negative effect and institutional ownership and managerial ownership do not significantly affect the potential for bankruptcy.

  11. Cannabinoid hyperemesis syndrome: potential mechanisms for the benefit of capsaicin and hot water hydrotherapy in treatment.

    Science.gov (United States)

    Richards, John R; Lapoint, Jeff M; Burillo-Putze, Guillermo

    2018-01-01

    Cannabinoid hyperemesis syndrome is a clinical disorder that has become more prevalent with increasing use of cannabis and synthetic cannabinoids, and which is difficult to treat. Standard antiemetics commonly fail to alleviate the severe nausea and vomiting characteristic of the syndrome. Curiously, cannabinoid hyperemesis syndrome patients often report dramatic relief of symptoms with hot showers and baths, and topical capsaicin. In this review, we detail the pharmacokinetics and pharmacodynamics of capsaicin and explore possible mechanisms for its beneficial effect, including activation of transient receptor potential vanilloid 1 and neurohumoral regulation. Putative mechanisms responsible for the benefit of hot water hydrotherapy are also investigated. An extensive search of PubMed, OpenGrey, and Google Scholar from inception to April 2017 was performed to identify known and theoretical thermoregulatory mechanisms associated with the endocannabinoid system. The searches resulted in 2417 articles. These articles were screened for relevant mechanisms behind capsaicin and heat activation having potential antiemetic effects. References from the selected articles were also hand-searched. A total of 137 articles were considered relevant and included. Capsaicin: Topical capsaicin is primarily used for treatment of neuropathic pain, but it has also been used successfully in some 20 cases of cannabinoid hyperemesis syndrome. The pharmacokinetics and pharmacodynamics of capsaicin as a transient receptor potential vanilloid 1 agonist may explain this effect. Topical capsaicin has a longer half-life than oral administration, thus its potential duration of benefit is longer. Capsaicin and transient receptor potential vanilloid 1: Topical capsaicin binds and activates the transient receptor potential vanilloid 1 receptor, triggering influx of calcium and sodium, as well as release of inflammatory neuropeptides leading to transient burning, stinging, and itching. This elicits

  12. Multiple mechanisms involved in the large-spectrum therapeutic potential of cannabidiol in psychiatric disorders

    Science.gov (United States)

    Campos, Alline Cristina; Moreira, Fabricio Araújo; Gomes, Felipe Villela; Del Bel, Elaine Aparecida; Guimarães, Francisco Silveira

    2012-01-01

    Cannabidiol (CBD) is a major phytocannabinoid present in the Cannabis sativa plant. It lacks the psychotomimetic and other psychotropic effects that the main plant compound Δ9-tetrahydrocannabinol (THC) being able, on the contrary, to antagonize these effects. This property, together with its safety profile, was an initial stimulus for the investigation of CBD pharmacological properties. It is now clear that CBD has therapeutic potential over a wide range of non-psychiatric and psychiatric disorders such as anxiety, depression and psychosis. Although the pharmacological effects of CBD in different biological systems have been extensively investigated by in vitro studies, the mechanisms responsible for its therapeutic potential are still not clear. Here, we review recent in vivo studies indicating that these mechanisms are not unitary but rather depend on the behavioural response being measured. Acute anxiolytic and antidepressant-like effects seem to rely mainly on facilitation of 5-HT1A-mediated neurotransmission in key brain areas related to defensive responses, including the dorsal periaqueductal grey, bed nucleus of the stria terminalis and medial prefrontal cortex. Other effects, such as anti-compulsive, increased extinction and impaired reconsolidation of aversive memories, and facilitation of adult hippocampal neurogenesis could depend on potentiation of anandamide-mediated neurotransmission. Finally, activation of TRPV1 channels may help us to explain the antipsychotic effect and the bell-shaped dose-response curves commonly observed with CBD. Considering its safety profile and wide range of therapeutic potential, however, further studies are needed to investigate the involvement of other possible mechanisms (e.g. inhibition of adenosine uptake, inverse agonism at CB2 receptor, CB1 receptor antagonism, GPR55 antagonism, PPARγ receptors agonism, intracellular (Ca2+) increase, etc.), on CBD behavioural effects. PMID:23108553

  13. Lifelong bilingualism and neural reserve against Alzheimer's disease: a review of findings and potential mechanisms.

    Science.gov (United States)

    Gold, Brian T

    2015-03-15

    Alzheimer's disease (AD) is a progressive brain disorder that initially affects medial temporal lobe circuitry and memory functions. Current drug treatments have only modest effects on the symptomatic course of the disease. In contrast, a growing body of evidence suggests that lifelong bilingualism may delay the onset of clinical AD symptoms by several years. The purpose of the present review is to summarize evidence for bilingualism as a reserve variable against AD and discuss potential underlying neurocognitive mechanisms. Evidence is reviewed suggesting that bilingualism may delay clinical AD symptoms by protecting frontostriatal and frontoparietal executive control circuitry rather than medial temporal lobe memory circuitry. Cellular and molecular mechanisms that may contribute to bilingual cognitive reserve effects are discussed, including those that may affect neuronal metabolic functions, dynamic neuronal-glial interactions, vascular factors, myelin structure and neurochemical signaling. Future studies that may test some of these potential mechanisms of bilingual CR effects are proposed. Copyright © 2014 Elsevier B.V. All rights reserved.

  14. Impacts of prenatal triclosan exposure on fetal reproductive hormones and its potential mechanism.

    Science.gov (United States)

    Wang, Caifeng; Chen, Limei; Zhao, Shasha; Hu, Yi; Zhou, Yijun; Gao, Yu; Wang, Weiye; Zhang, Jun; Tian, Ying

    2018-02-01

    Triclosan (TCS) has been widely detected in pregnant women. The reproductive endocrine-disrupting effects of TCS have been observed in humans and animals. Little is known about the potential impact of prenatal TCS exposure on fetal reproductive development as well as its potential mechanism. We investigated the potential effect of prenatal TCS exposure on fetal reproductive hormones in cord blood and its potential mechanism in relation to placental steroidogenic enzymes. Urinary TCS was detected among 537 healthy pregnant women from a prospective cohort in China. Four reproductive hormones in cord blood, namely E 2 (n=430), T (n=424), LH (n=428) and FSH (n=373), and three steroidogenic enzymes in placenta, namely P450arom (n=233), 3β-HSD (n=227) and 17β-HSD (n=222), were measured. Prenatal TCS exposure was associated with increased testosterone concentrations in cord blood in a dose-dependent manner. Infants with prenatal TCS levels >0.6μg/L had, on average, a 0.23ng/mL (95% CI: 0.05, 0.45, p=0.02) higher testosterone concentrations in cord blood compared to those with prenatal TCS levels prenatal TCS exposure was associated with increased testosterone and decreased E 2 concentrations in cord blood among male infants. Adverse associations were found between the prenatal TCS exposure and concentrations of three placental steroidogenic enzymes. 3β-HSD and P450arom demonstrated mediating effects in the association between prenatal TCS exposure and testosterone concentrations in cord blood. Our findings suggested potential impacts of prenatal TCS exposure on reproductive hormones in cord blood mediated by steroidogenic enzymes, and male infants were more vulnerable. Copyright © 2017 Elsevier Ltd. All rights reserved.

  15. Potential of wind power projects under the Clean Development Mechanism in India.

    Science.gov (United States)

    Purohit, Pallav; Michaelowa, Axel

    2007-07-30

    So far, the cumulative installed capacity of wind power projects in India is far below their gross potential (tax benefits, long term financing schemes etc., for more than 10 years etc. One of the major barriers is the high costs of investments in these systems. The Clean Development Mechanism (CDM) of the Kyoto Protocol provides industrialized countries with an incentive to invest in emission reduction projects in developing countries to achieve a reduction in CO2 emissions at lowest cost that also promotes sustainable development in the host country. Wind power projects could be of interest under the CDM because they directly displace greenhouse gas emissions while contributing to sustainable rural development, if developed correctly. Our estimates indicate that there is a vast theoretical potential of CO2 mitigation by the use of wind energy in India. The annual potential Certified Emissions Reductions (CERs) of wind power projects in India could theoretically reach 86 million. Under more realistic assumptions about diffusion of wind power projects based on past experiences with the government-run programmes, annual CER volumes by 2012 could reach 41 to 67 million and 78 to 83 million by 2020. The projections based on the past diffusion trend indicate that in India, even with highly favorable assumptions, the dissemination of wind power projects is not likely to reach its maximum estimated potential in another 15 years. CDM could help to achieve the maximum utilization potential more rapidly as compared to the current diffusion trend if supportive policies are introduced.

  16. Mechanisms of action of ligands of potential-dependent sodium channels.

    Science.gov (United States)

    Tikhonov, D B

    2008-06-01

    Potential-dependent sodium channels play a leading role in generating action potentials in excitable cells. Sodium channels are the site of action of a variety of modulator ligands. Despite numerous studies, the mechanisms of action of many modulators remain incompletely understood. The main reason that many important questions cannot be resolved is that there is a lack of precise data on the structures of the channels themselves. Structurally, potential-dependent sodium channels are members of the P-loop channel superfamily, which also include potassium and calcium channels and glutamate receptor channels. Crystallization of a series of potassium channels showed that it was possible to analyze the structures of different members of the superfamily using the "homologous modeling" method. The present study addresses model investigations of the actions of ligands of sodium channels, including tetrodotoxin and batrachotoxin, as well as local anesthetics. Comparison of experimental data on sodium channel ligands with x-ray analysis data allowed us to reach a new level of understanding of the mechanisms of channel modulation and to propose a series of experimentally verifiable hypotheses.

  17. Supersymmetric quantum mechanics: Engineered hierarchies of integrable potentials and related orthogonal polynomials

    Energy Technology Data Exchange (ETDEWEB)

    Balondo Iyela, Daddy [International Chair in Mathematical Physics and Applications (ICMPA–UNESCO Chair), University of Abomey–Calavi, 072 B. P. 50 Cotonou, Republic of Benin (Benin); Centre for Cosmology, Particle Physics and Phenomenology (CP3), Institut de Recherche en Mathématique et Physique (IRMP), Université catholique de Louvain U.C.L., 2, Chemin du Cyclotron, B-1348 Louvain-la-Neuve (Belgium); Département de Physique, Université de Kinshasa (UNIKIN), B.P. 190 Kinshasa XI, Democratic Republic of Congo (Congo, The Democratic Republic of the); Govaerts, Jan [International Chair in Mathematical Physics and Applications (ICMPA–UNESCO Chair), University of Abomey–Calavi, 072 B. P. 50 Cotonou, Republic of Benin (Benin); Centre for Cosmology, Particle Physics and Phenomenology (CP3), Institut de Recherche en Mathématique et Physique (IRMP), Université catholique de Louvain U.C.L., 2, Chemin du Cyclotron, B-1348 Louvain-la-Neuve (Belgium); Hounkonnou, M. Norbert [International Chair in Mathematical Physics and Applications (ICMPA–UNESCO Chair), University of Abomey–Calavi, 072 B. P. 50 Cotonou, Republic of Benin (Benin)

    2013-09-15

    Within the context of supersymmetric quantum mechanics and its related hierarchies of integrable quantum Hamiltonians and potentials, a general programme is outlined and applied to its first two simplest illustrations. Going beyond the usual restriction of shape invariance for intertwined potentials, it is suggested to require a similar relation for Hamiltonians in the hierarchy separated by an arbitrary number of levels, N. By requiring further that these two Hamiltonians be in fact identical up to an overall shift in energy, a periodic structure is installed in the hierarchy which should allow for its resolution. Specific classes of orthogonal polynomials characteristic of such periodic hierarchies are thereby generated, while the methods of supersymmetric quantum mechanics then lead to generalised Rodrigues formulae and recursion relations for such polynomials. The approach also offers the practical prospect of quantum modelling through the engineering of quantum potentials from experimental energy spectra. In this paper, these ideas are presented and solved explicitly for the cases N= 1 and N= 2. The latter case is related to the generalised Laguerre polynomials, for which indeed new results are thereby obtained. In the context of dressing chains and deformed polynomial Heisenberg algebras, some partial results for N⩾ 3 also exist in the literature, which should be relevant to a complete study of the N⩾ 3 general periodic hierarchies.

  18. Potential mechanisms behind the antioxidant actions of prolactin in the retina.

    Science.gov (United States)

    Thébault, Stéphanie

    2017-07-01

    Causes for age-related retinal diseases are numerous and complex, and they are intertwined with the natural vision decline that accompanies aging. The elucidation of endogenous mechanisms that help maintain retinal function under conditions that are threatening for the eye and happen during natural aging is therefore critical in developing new prevention and therapeutic strategies against age-related retinal degeneration. Our lab recently reported that the hormone of lactation, prolactin, helps the retinal pigment epithelium to survive via antioxidant actions that result in the inhibition of sirtuin2-dependent cell death (EbioMedicine issue of May). The mechanism behind the antioxidant activity of prolactin remains elusive. The main purposes of my commentary are to discuss mechanisms that could explain this effect in the context of previously identified defense mechanisms against oxidative stress and focus particularly on the potential regulation of reduced glutathione levels by prolactin. I also briefly comment on how our study contributes to cell biology, which as the foundational science for understanding neurodegeneration, may accelerate progress in disease prevention and cures. Copyright © 2017 Elsevier Ltd. All rights reserved.

  19. The Cardioprotective Effects of Hydrogen Sulfide in Heart Diseases: From Molecular Mechanisms to Therapeutic Potential.

    Science.gov (United States)

    Shen, Yaqi; Shen, Zhuqing; Luo, Shanshan; Guo, Wei; Zhu, Yi Zhun

    2015-01-01

    Hydrogen sulfide (H2S) is now recognized as a third gaseous mediator along with nitric oxide (NO) and carbon monoxide (CO), though it was originally considered as a malodorous and toxic gas. H2S is produced endogenously from cysteine by three enzymes in mammalian tissues. An increasing body of evidence suggests the involvement of H2S in different physiological and pathological processes. Recent studies have shown that H2S has the potential to protect the heart against myocardial infarction, arrhythmia, hypertrophy, fibrosis, ischemia-reperfusion injury, and heart failure. Some mechanisms, such as antioxidative action, preservation of mitochondrial function, reduction of apoptosis, anti-inflammatory responses, angiogenic actions, regulation of ion channel, and interaction with NO, could be responsible for the cardioprotective effect of H2S. Although several mechanisms have been identified, there is a need for further research to identify the specific molecular mechanism of cardioprotection in different cardiac diseases. Therefore, insight into the molecular mechanisms underlying H2S action in the heart may promote the understanding of pathophysiology of cardiac diseases and lead to new therapeutic targets based on modulation of H2S production.

  20. The Cardioprotective Effects of Hydrogen Sulfide in Heart Diseases: From Molecular Mechanisms to Therapeutic Potential

    Directory of Open Access Journals (Sweden)

    Yaqi Shen

    2015-01-01

    Full Text Available Hydrogen sulfide (H2S is now recognized as a third gaseous mediator along with nitric oxide (NO and carbon monoxide (CO, though it was originally considered as a malodorous and toxic gas. H2S is produced endogenously from cysteine by three enzymes in mammalian tissues. An increasing body of evidence suggests the involvement of H2S in different physiological and pathological processes. Recent studies have shown that H2S has the potential to protect the heart against myocardial infarction, arrhythmia, hypertrophy, fibrosis, ischemia-reperfusion injury, and heart failure. Some mechanisms, such as antioxidative action, preservation of mitochondrial function, reduction of apoptosis, anti-inflammatory responses, angiogenic actions, regulation of ion channel, and interaction with NO, could be responsible for the cardioprotective effect of H2S. Although several mechanisms have been identified, there is a need for further research to identify the specific molecular mechanism of cardioprotection in different cardiac diseases. Therefore, insight into the molecular mechanisms underlying H2S action in the heart may promote the understanding of pathophysiology of cardiac diseases and lead to new therapeutic targets based on modulation of H2S production.

  1. Mechanisms of radiation interaction with DNA: Potential implications for radiation protection

    International Nuclear Information System (INIS)

    Sinclair, W.K.; Fry, R.J.M.

    1987-01-01

    An overview of presentations and discussions which took place at the US Department of Energy/Commission of European Communities (DOE/CEC) workshop on ''Mechanisms of Radiation Interaction with DNA: Potential Implications for Radiation Protection,'' held at San Diego, California, January 21-22, 1987, is provided. The Department has traditionally supported fundamental research on interactions of ionizing radiation with different biological systems and at all levels of biological organization. The aim of this workshop was to review the base of knowledge in the area of mechanisms of radiation action at the DNA level, and to explore ways in which this information can be applied to the development of scientifically sound concepts and procedures for use in the field of radiation protection

  2. Fundamental transport mechanisms, fabrication and potential applications of nanoporous atomically thin membranes

    Science.gov (United States)

    Wang, Luda; Boutilier, Michael S. H.; Kidambi, Piran R.; Jang, Doojoon; Hadjiconstantinou, Nicolas G.; Karnik, Rohit

    2017-06-01

    Graphene and other two-dimensional materials offer a new approach to controlling mass transport at the nanoscale. These materials can sustain nanoscale pores in their rigid lattices and due to their minimum possible material thickness, high mechanical strength and chemical robustness, they could be used to address persistent challenges in membrane separations. Here we discuss theoretical and experimental developments in the emerging field of nanoporous atomically thin membranes, focusing on the fundamental mechanisms of gas- and liquid-phase transport, membrane fabrication techniques and advances towards practical application. We highlight potential functional characteristics of the membranes and discuss applications where they are expected to offer advantages. Finally, we outline the major scientific questions and technological challenges that need to be addressed to bridge the gap from theoretical simulations and proof-of-concept experiments to real-world applications.

  3. A Gut Feeling to Cure Diabetes: Potential Mechanisms of Diabetes Remission after Bariatric Surgery

    Directory of Open Access Journals (Sweden)

    Young Min Cho

    2014-12-01

    Full Text Available A cure for type 2 diabetes was once a mere dream but has now become a tangible and achievable goal with the unforeseen success of bariatric surgery in the treatment of both obesity and type 2 diabetes. Popular bariatric procedures such as Roux-en-Y gastric bypass and sleeve gastrectomy exhibit high rates of diabetes remission or marked improvement in glycemic control. However, the mechanism of diabetes remission following these procedures is still elusive and appears to be very complex and encompasses multiple anatomical and physiological changes. In this article, calorie restriction, improved β-cell function, improved insulin sensitivity, and alterations in gut physiology, bile acid metabolism, and gut microbiota are reviewed as potential mechanisms of diabetes remission after Roux-en-Y gastric bypass and sleeve gastrectomy.

  4. Mechanism of Action and Clinical Potential of Fingolimod for the Treatment of Stroke

    Directory of Open Access Journals (Sweden)

    Wentao Li

    2016-08-01

    Full Text Available Fingolimod (FTY720 is an orally bio-available immunomodulatory drug currently approved by the FDA for the treatment of multiple sclerosis. Currently, there is a significant interest in the potential benefits of FTY720 on stroke outcomes. FTY720 and the sphingolipid signaling pathway it modulates has a ubiquitous presence in the central nervous system and both rodent models and pilot clinical trials seem to indicate that the drug may improve overall functional recovery in different stroke subtypes. Although the precise mechanisms behind these beneficial effects are yet unclear, there is evidence that FTY720 has a role in regulating cerebrovascular responses, blood brain barrier permeability, and cell survival in the event of cerebrovascular insult. In this article, we critically review the data obtained from the latest laboratory findings and clinical trials involving both ischemic and hemorrhagic stroke, and attempt to form a cohesive picture of FTY720’s mechanisms of action in stroke

  5. Maternal childhood trauma, postpartum depression, and infant outcomes: Avoidant affective processing as a potential mechanism.

    Science.gov (United States)

    Choi, Karmel W; Sikkema, Kathleen J; Vythilingum, Bavi; Geerts, Lut; Faure, Sheila C; Watt, Melissa H; Roos, Annerine; Stein, Dan J

    2017-03-15

    Women who have experienced childhood trauma may be at risk for postpartum depression, increasing the likelihood of negative outcomes among their children. Predictive pathways from maternal childhood trauma to child outcomes, as mediated by postpartum depression, require investigation. A longitudinal sample of South African women (N=150) was followed through pregnancy and postpartum. Measures included maternal trauma history reported during pregnancy; postpartum depression through six months; and maternal-infant bonding, infant development, and infant physical growth at one year. Structural equation models tested postpartum depression as a mediator between maternal experiences of childhood trauma and children's outcomes. A subset of women (N=33) also participated in a lab-based emotional Stroop paradigm, and their responses to fearful stimuli at six weeks were explored as a potential mechanism linking maternal childhood trauma, postpartum depression, and child outcomes. Women with childhood trauma experienced greater depressive symptoms through six months postpartum, which then predicted negative child outcomes at one year. Mediating effects of postpartum depression were significant, and persisted for maternal-infant bonding and infant growth after controlling for covariates and antenatal distress. Maternal avoidance of fearful stimuli emerged as a potential affective mechanism. Limitations included modest sample size, self-report measures, and unmeasured potential confounders. Findings suggest a mediating role of postpartum depression in the intergenerational transmission of negative outcomes. Perinatal interventions that address maternal trauma histories and depression, as well as underlying affective mechanisms, may help interrupt cycles of disadvantage, particularly in high-trauma settings such as South Africa. Copyright © 2017. Published by Elsevier B.V.

  6. A review of potential neurotoxic mechanisms among three chlorinated organic solvents

    International Nuclear Information System (INIS)

    Bale, Ambuja S.; Barone, Stan; Scott, Cheryl Siegel; Cooper, Glinda S.

    2011-01-01

    The potential for central nervous system depressant effects from three widely used chlorinated solvents, trichloroethylene (TCE), perchloroethylene (PERC), and dichloromethane (DCM), has been shown in human and animal studies. Commonalities of neurobehavioral and neurophysiological changes for the chlorinated solvents in in vivo studies suggest that there is a common mechanism(s) of action in producing resultant neurotoxicological consequences. The purpose of this review is to examine the mechanistic studies conducted with these chlorinated solvents and to propose potential mechanisms of action for the different neurological effects observed. Mechanistic studies indicate that this solvent class has several molecular targets in the brain. Additionally, there are several pieces of evidence from animal studies indicating this solvent class alters neurochemical functions in the brain. Although earlier evidence indicated that these three chlorinated solvents perturb the lipid bilayer, more recent data suggest an interaction between several specific neuronal receptors produces the resultant neurobehavioral effects. Collectively, TCE, PERC, and DCM have been reported to interact directly with several different classes of neuronal receptors by generally inhibiting excitatory receptors/channels and potentiating the function of inhibitory receptors/channels. Given this mechanistic information and available studies for TCE, DCM, and PERC, we provide hypotheses on primary targets (e.g. ion channel targets) that appear to be most influential in producing the resultant neurological effects. - Research highlights: → Comparison of neurological effects among TCE, PERC, and DCM. → Correlation of mechanistic findings to neurological effects. → Data support that TCE, PERC, and DCM interact with several ion channels to produce neurological changes.

  7. Potential of AbiS as defence mechanism determined by conductivity measurement

    DEFF Research Database (Denmark)

    Holubová, Jitka; Josephsen, Jytte

    2007-01-01

    Aim: To compare pH and conductivity used in the determination of growth in reconstituted skim milk (RSM), to determine whether the presence of one or two plasmids in Lactococcus lactis had any influence on growth, and whether AbiS improved bacteriophages resistance of L. lactis. Methods and Results...... either AbiS1 or the restriction modification system LlaBIII was present. Conclusions: The earliest detection of growth was observed by measuring pH, rather than conductance. The plasmid-encoded AbiS system has a potential to be used as a phage resistance mechanisms in L. lactis during milk fermentations...

  8. Mechanically Reconfigurable Microstrip Lines Loaded with Stepped Impedance Resonators and Potential Applications

    Directory of Open Access Journals (Sweden)

    J. Naqui

    2014-01-01

    Full Text Available This paper is focused on exploring the possibilities and potential applications of microstrip transmission lines loaded with stepped impedance resonators (SIRs etched on top of the signal strip, in a separated substrate. It is shown that if the symmetry plane of the line (a magnetic wall is perfectly aligned with the electric wall of the SIR at the fundamental resonance, the line is transparent. However, if symmetry is somehow ruptured, a notch in the transmission coefficient appears. The notch frequency and depth can thus be mechanically controlled, and this property can be of interest for the implementation of sensors and barcodes, as it is discussed.

  9. Cannabinoids from Cannabis sp.: mechanism of their activity and potential health benefits in human body

    OpenAIRE

    Dąbrowski, Grzegorz; Skrajda, Marta

    2017-01-01

    Dąbrowski Grzegorz, Skrajda Marta, Cannabinoids from Cannabis sp.: mechanism of their activity and potential health benefits in human body. Journal of Education, Health and Sport. 2017;7(8):936-945. eISSN 2391-8306. DOI http://dx.doi.org/10.5281/zenodo.995625 http://ojs.ukw.edu.pl/index.php/johs/article/view/4876 The journal has had 7 points in Ministry of Science and Higher Education parametric evaluation. Part B item 1223 (26.01.2017). 1223 Jo...

  10. Prediction of Tetraoxygen Reaction Mechanism with Sulfur Atom on the Singlet Potential Energy Surface

    Directory of Open Access Journals (Sweden)

    Ashraf Khademzadeh

    2014-01-01

    Full Text Available The mechanism of S+O4 (D2h reaction has been investigated at the B3LYP/6-311+G(3df and CCSD levels on the singlet potential energy surface. One stable complex has been found for the S+O4 (D2h reaction, IN1, on the singlet potential energy surface. For the title reaction, we obtained four kinds of products at the B3LYP level, which have enough thermodynamic stability. The results reveal that the product P3 is spontaneous and exothermic with −188.042 and −179.147 kcal/mol in Gibbs free energy and enthalpy of reaction, respectively. Because P1 adduct is produced after passing two low energy level transition states, kinetically, it is the most favorable adduct in the 1S+1O4 (D2h atmospheric reactions.

  11. Reaction Mechanisms on Multiwell Potential Energy Surfaces in Combustion (and Atmospheric) Chemistry

    International Nuclear Information System (INIS)

    Osborn, David L.

    2017-01-01

    Chemical reactions occurring on a potential energy surface with multiple wells are ubiquitous in low temperature combustion and the oxidation of volatile organic compounds in earth’s atmosphere. The rich variety of structural isomerizations that compete with collisional stabilization make characterizing such complex-forming reactions challenging. This review describes recent experimental and theoretical advances that deliver increasingly complete views of their reaction mechanisms. New methods for creating reactive intermediates coupled with multiplexed measurements provide many experimental observables simultaneously. Automated methods to explore potential energy surfaces can uncover hidden reactive pathways, while master equation methods enable a holistic treatment of both sequential and well-skipping pathways. Our ability to probe and understand nonequilibrium effects and reaction sequences is increasing. These advances provide the fundamental science base for predictive models of combustion and the atmosphere that are crucial to address global challenges.

  12. Reaction Mechanisms on Multiwell Potential Energy Surfaces in Combustion (and Atmospheric) Chemistry

    Science.gov (United States)

    Osborn, David L.

    2017-05-01

    Chemical reactions occurring on a potential energy surface with multiple wells are ubiquitous in low-temperature combustion and in the oxidation of volatile organic compounds in Earth's atmosphere. The rich variety of structural isomerizations that compete with collisional stabilization makes characterizing such complex-forming reactions challenging. This review describes recent experimental and theoretical advances that deliver increasingly complete views of their reaction mechanisms. New methods for creating reactive intermediates coupled with multiplexed measurements provide many experimental observables simultaneously. Automated methods to explore potential energy surfaces can uncover hidden reactive pathways, and master equation methods enable a holistic treatment of both sequential and well-skipping pathways. Our ability to probe and understand nonequilibrium effects and reaction sequences is increasing. These advances provide the fundamental science base for predictive models of combustion and the atmosphere that are crucial to address global challenges.

  13. Plant-Microbial Interactions Define Potential Mechanisms of Organic Matter Priming in the Rhizosphere

    Science.gov (United States)

    Zhalnina, K.; Cho, H. J.; Hao, Z.; Mansoori, N.; Karaoz, U.; Jenkins, S.; White, R. A., III; Lipton, M. S.; Deng, K.; Zhou, J.; Pett-Ridge, J.; Northen, T.; Firestone, M. K.; Brodie, E.

    2015-12-01

    In the rhizosphere, metabolic processes of plants and microorganisms are closely coupled, and together with soil minerals, their interactions regulate the turnover of soil organic C (SOC). Plants provide readily assimilable metabolites for microorganisms through exudation, and it has been hypothesized that increasing concentrations of exudate C may either stimulate or suppress rates of SOC mineralization (rhizosphere priming). Both positive and negative rhizosphere priming has been widely observed, however the underlying mechanisms remain poorly understood. To begin to identify the molecular mechanisms underlying rhizosphere priming, we isolated a broad range of soil bacteria from a Mediterranean grassland dominated by annual grass. Thirty-nine heterotrophic bacteria were selected for genome sequencing and both rRNA gene analysis and metagenome coverage suggest that these isolates represent naturally abundant strain variants. We analyzed their genomes for potential metabolic traits related to life in the rhizosphere and the decomposition of polymeric SOC. While the two dominant groups, Alphaproteobacteria and Actinobacteria, were enriched in polymer degrading enzymes, Alphaproteobacterial isolates contained greater gene copies of transporters related to amino acid, organic acid and auxin uptake or export, suggesting an enhanced metabolic potential for life in the root zone. To verify this metabolic potential, we determined the enzymatic activities of these isolates and revealed preferences of strains to degrade certain polymers (xylan, cellulose or lignin). Fourier Transform Infrared spectroscopy is being used to determine which polymeric components of plant roots are targeted by specific strains and how exudates may impact their degradation. To verify the potential of isolates to assimilate root exudates and export key metabolites we are using LC-MS/MS based exometabolomic profiling. The traits hypothesized and verified here (transporters, enzymes, exudate uptake

  14. Chemical compounds from anthropogenic environment and immune evasion mechanisms: potential interactions.

    Science.gov (United States)

    Kravchenko, Julia; Corsini, Emanuela; Williams, Marc A; Decker, William; Manjili, Masoud H; Otsuki, Takemi; Singh, Neetu; Al-Mulla, Faha; Al-Temaimi, Rabeah; Amedei, Amedeo; Colacci, Anna Maria; Vaccari, Monica; Mondello, Chiara; Scovassi, A Ivana; Raju, Jayadev; Hamid, Roslida A; Memeo, Lorenzo; Forte, Stefano; Roy, Rabindra; Woodrick, Jordan; Salem, Hosni K; Ryan, Elizabeth P; Brown, Dustin G; Bisson, William H; Lowe, Leroy; Lyerly, H Kim

    2015-06-01

    An increasing number of studies suggest an important role of host immunity as a barrier to tumor formation and progression. Complex mechanisms and multiple pathways are involved in evading innate and adaptive immune responses, with a broad spectrum of chemicals displaying the potential to adversely influence immunosurveillance. The evaluation of the cumulative effects of low-dose exposures from the occupational and natural environment, especially if multiple chemicals target the same gene(s) or pathway(s), is a challenge. We reviewed common environmental chemicals and discussed their potential effects on immunosurveillance. Our overarching objective was to review related signaling pathways influencing immune surveillance such as the pathways involving PI3K/Akt, chemokines, TGF-β, FAK, IGF-1, HIF-1α, IL-6, IL-1α, CTLA-4 and PD-1/PDL-1 could individually or collectively impact immunosurveillance. A number of chemicals that are common in the anthropogenic environment such as fungicides (maneb, fluoxastrobin and pyroclostrobin), herbicides (atrazine), insecticides (pyridaben and azamethiphos), the components of personal care products (triclosan and bisphenol A) and diethylhexylphthalate with pathways critical to tumor immunosurveillance. At this time, these chemicals are not recognized as human carcinogens; however, it is known that they these chemicalscan simultaneously persist in the environment and appear to have some potential interfere with the host immune response, therefore potentially contributing to promotion interacting with of immune evasion mechanisms, and promoting subsequent tumor growth and progression. © The Author 2015. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  15. Thermo-mechanical stress analysis of cryopreservation in cryobags and the potential benefit of nanowarming.

    Science.gov (United States)

    Solanki, Prem K; Bischof, John C; Rabin, Yoed

    2017-06-01

    Cryopreservation by vitrification is the only promising solution for long-term organ preservation which can save tens of thousands of lives across the world every year. One of the challenges in cryopreservation of large-size tissues and organs is to prevent fracture formation due to the tendency of the material to contract with temperature. The current study focuses on a pillow-like shape of a cryobag, while exploring various strategies to reduce thermo-mechanical stress during the rewarming phase of the cryopreservation protocol, where maximum stresses are typically found. It is demonstrated in this study that while the level of stress may generally increase with the increasing amount of CPA filled in the cryobag, the ratio between width and length of the cryobag play a significant role. Counterintuitively, the overall maximum stress is not found when the bag is filled to its maximum capacity (when the filled cryobag resembles a sphere). Parametric investigation suggests that reducing the initial rewarming rate between the storage temperature and the glass transition temperature may dramatically decrease the thermo-mechanical stress. Adding a temperature hold during rewarming at the glass transition temperature may reduce the thermo-mechanical stress in some cases, but may have an adverse effect in other cases. Finally, it is demonstrated that careful incorporation of volumetric heating by means on nanoparticles in an alternating magnetic field, or nanowarming, can dramatically reduce the resulting thermo-mechanical stress. These observations display the potential benefit of a thermo-mechanical design of the cryopreservation protocols in order to prevent structural damage. Copyright © 2017 Elsevier Inc. All rights reserved.

  16. Organizational mechanism for imlementation of the travel agency financial potential development strategy

    Directory of Open Access Journals (Sweden)

    І.V. Saukh

    2017-03-01

    Full Text Available The article discusses the implementation of the financial development strategy as a set of means required for its accomplishment, including consecutive execution of this strategy, creation of the communication channels, distribution of duties between the parties to the strategic plan, and formation of the system of strategic control. The research analyzes the scientific and methodological approaches used to implement the strategy and form the organizational mechanism of this process within the development of the company's financial potential, based on the use of systemic approach and the concept of strategic change. The paper reveals that travel companies are not able to apply the unified approach to accomplish this strategy, because the process of its implementation is creative and informal. Moreover, it is greatly influenced by the activity of each business. The organizational mechanism of this strategic development embraces a complex of levels, stages, instruments and methods of organizational change. Their systemic application contributes to the development of the company's financial strength. The structure of this organizational mechanism is described as the result of the analysis of traditional and situational methodological approaches to the strategy's formalization and implementation. It centers around the concept of strategic change and seamless cooperation of the target, subject-to-object (injunctive and process-related (regulatory subsystems of the developed mechanism. The mechanism allows to pinpoint and implement the strategies aimed at the development of the company's financial resources and its other structural units. In order to simplify the process of coordination of the subjects implementing the strategy in real-time business activities, the operogram for strategic analysis of the financial development is created. It can be used to optimize the duration of this analysis and allocate the company’s resources in the most

  17. Assessment of clean development mechanism potential of large-scale energy efficiency measures in heavy industries

    International Nuclear Information System (INIS)

    Hayashi, Daisuke; Krey, Matthias

    2007-01-01

    This paper assesses clean development mechanism (CDM) potential of large-scale energy efficiency measures in selected heavy industries (iron and steel, cement, aluminium, pulp and paper, and ammonia) taking India and Brazil as examples of CDM project host countries. We have chosen two criteria for identification of the CDM potential of each energy efficiency measure: (i) emission reductions volume (in CO 2 e) that can be expected from the measure and (ii) likelihood of the measure passing the additionality test of the CDM Executive Board (EB) when submitted as a proposed CDM project activity. The paper shows that the CDM potential of large-scale energy efficiency measures strongly depends on the project-specific and country-specific context. In particular, technologies for the iron and steel industry (coke dry quenching (CDQ), top pressure recovery turbine (TRT), and basic oxygen furnace (BOF) gas recovery), the aluminium industry (point feeder prebake (PFPB) smelter), and the pulp and paper industry (continuous digester technology) offer promising CDM potential

  18. Rapid, computer vision-enabled murine screening system identifies neuropharmacological potential of two new mechanisms

    Directory of Open Access Journals (Sweden)

    Steven L Roberds

    2011-09-01

    Full Text Available The lack of predictive in vitro models for behavioral phenotypes impedes rapid advancement in neuropharmacology and psychopharmacology. In vivo behavioral assays are more predictive of activity in human disorders, but such assays are often highly resource-intensive. Here we describe the successful application of a computer vision-enabled system to identify potential neuropharmacological activity of two new mechanisms. The analytical system was trained using multiple drugs that are used clinically to treat depression, schizophrenia, anxiety, and other psychiatric or behavioral disorders. During blinded testing the PDE10 inhibitor TP-10 produced a signature of activity suggesting potential antipsychotic activity. This finding is consistent with TP-10’s activity in multiple rodent models that is similar to that of clinically used antipsychotic drugs. The CK1ε inhibitor PF-670462 produced a signature consistent with anxiolytic activity and, at the highest dose tested, behavioral effects similar to that of opiate analgesics. Neither TP-10 nor PF-670462 was included in the training set. Thus, computer vision-based behavioral analysis can facilitate drug discovery by identifying neuropharmacological effects of compounds acting through new mechanisms.

  19. Seawater-drowning-induced acute lung injury: From molecular mechanisms to potential treatments.

    Science.gov (United States)

    Jin, Faguang; Li, Congcong

    2017-06-01

    Drowning is a crucial public safety problem and is the third leading cause of accidental fatality, claiming ~372,000 lives annually, worldwide. In near-drowning patients, acute lung injury (ALI) or acute respiratory distress syndrome (ARDS) is one of the most common complications. Approximately 1/3 of near-drowning patients fulfill the criteria for ALI or ARDS. In the present article, the current literature of near-drowning, pathophysiologic changes and the molecular mechanisms of seawater-drowning-induced ALI and ARDS was reviewed. Seawater is three times more hyperosmolar than plasma, and following inhalation of seawater the hyperosmotic seawater may cause serious injury in the lung and alveoli. The perturbing effects of seawater may be primarily categorized into insufficiency of pulmonary surfactant, blood-air barrier disruption, formation of pulmonary edema, inflammation, oxidative stress, autophagy, apoptosis and various other hypertonic stimulation. Potential treatments for seawater-induced ALI/ARDS were also presented, in addition to suggestions for further studies. A total of nine therapeutic strategies had been tested and all had focused on modulating the over-activated immunoreactions. In conclusion, seawater drowning is a complex injury process and the exact mechanisms and potential treatments require further exploration.

  20. Seawater-drowning-induced acute lung injury: From molecular mechanisms to potential treatments

    Science.gov (United States)

    Jin, Faguang; Li, Congcong

    2017-01-01

    Drowning is a crucial public safety problem and is the third leading cause of accidental fatality, claiming ~372,000 lives annually, worldwide. In near-drowning patients, acute lung injury (ALI) or acute respiratory distress syndrome (ARDS) is one of the most common complications. Approximately 1/3 of near-drowning patients fulfill the criteria for ALI or ARDS. In the present article, the current literature of near-drowning, pathophysiologic changes and the molecular mechanisms of seawater-drowning-induced ALI and ARDS was reviewed. Seawater is three times more hyperosmolar than plasma, and following inhalation of seawater the hyperosmotic seawater may cause serious injury in the lung and alveoli. The perturbing effects of seawater may be primarily categorized into insufficiency of pulmonary surfactant, blood-air barrier disruption, formation of pulmonary edema, inflammation, oxidative stress, autophagy, apoptosis and various other hypertonic stimulation. Potential treatments for seawater-induced ALI/ARDS were also presented, in addition to suggestions for further studies. A total of nine therapeutic strategies had been tested and all had focused on modulating the over-activated immunoreactions. In conclusion, seawater drowning is a complex injury process and the exact mechanisms and potential treatments require further exploration. PMID:28587319

  1. Genomic sequencing of a strain of Acinetobacter baumannii and potential mechanisms to antibiotics resistance.

    Science.gov (United States)

    Zhao, Lei; Li, Hongru; Zhu, Ziwen; Wakefield, Mark R; Fang, Yujiang; Ye, Ying

    2017-06-01

    Acinetobacter baumannii has been becoming a great challenge to clinicians due to their resistance to almost all available antibiotics. In this study, we sequenced the genome from a multiple antibiotics resistant Acinetobacter baumannii stain which was named A. baumannii-1isolated from China by SMRT sequencing technology to explore its potential mechanisms to antibiotic resistance. We found that several mechanisms might contribute to the antibiotic resistance of Acinetobacter baumannii. Specifically, we found that SNP in genes associated with nucleotide excision repair and ABC transporter might contribute to its resistance to multiple antibiotics; we also found that specific genes associated with bacterial DNA integration and recombination, DNA-mediated transposition and response to antibiotics might contribute to its resistance to multiple antibiotics; Furthermore, specific genes associated with penicillin and cephalosporin biosynthetic pathway and specific genes associated with CHDL and MBL β-lactamase genes might contribute to its resistance to multiple antibiotics. Thus, the detailed mechanisms by which Acinetobacter baumannii show extensive resistance to multiple antibiotics are very complicated. Such a study might be helpful to develop new strategies to control Acinetobacter baumannii infection. Copyright © 2017 Elsevier B.V. All rights reserved.

  2. An overview of potential molecular mechanisms involved in VSMC phenotypic modulation.

    Science.gov (United States)

    Zhang, Ming-Jie; Zhou, Yi; Chen, Lei; Wang, Yan-Qin; Wang, Xu; Pi, Yan; Gao, Chang-Yue; Li, Jing-Cheng; Zhang, Li-Li

    2016-02-01

    The fully differentiated medial vascular smooth muscle cells (VSMCs) of mature vessels keep quiescent and contractile. However, VSMC can exhibit the plasticity in phenotype switching from a differentiated and contractile phenotype to a dedifferentiated state in response to alterations in local environmental cues, which is called phenotypic modulation or switching. Distinguishing from its differentiated state expressing more smooth muscle (SM)-specific/selective proteins, the phenotypic modulation in VSMC is characterized by an increased rate of proliferation, migration, synthesis of extracellular matrix proteins and decreased expression of SM contractile proteins. Although it has been well demonstrated that phenotypic modulation of VSMC contributes to the occurrence and progression of many proliferative vascular diseases, little is known about the details of the molecular mechanisms of VSMC phenotypic modulation. Growing evidence suggests that variety of molecules including microRNAs, cytokines and biochemical factors, membrane receptors, ion channels, cytoskeleton and extracellular matrix play important roles in controlling VSMC phenotype. The focus of the present review is to provide an overview of potential molecular mechanisms involved in VSMC phenotypic modulation in recent years. To clarify VSMC differentiation and phenotypic modulation mechanisms will contribute to producing cell-based therapeutic interventions for aberrant VSMC differentiation-related diseases.

  3. Biological Communities in Desert Varnish and Potential Implications for Varnish Formation Mechanisms

    Science.gov (United States)

    Lang-Yona, Naama; Maier, Stefanie; Macholdt, Dorothea; Rodriguez-Caballero, Emilio; Müller-Germann, Isabell; Yordanova, Petya; Jochum, Klaus-Peter; Andreae, Meinrat O.; Pöschl, Ulrich; Weber, Bettina; Fröhlich-Nowoisky, Janine

    2017-04-01

    Desert varnishes are thin, orange to black coatings found on rocks in arid and semi-arid environments on Earth. The formation mechanisms of rock varnish are still under debate and the involvement of microorganisms in this process remains unclear. In this work we aimed to identify the microbial community occurring in rock varnish to potentially gain insights into the varnish formation mechanism. For this purpose, rocks coated with desert varnish were collected from the Anza-Borrego Desert, California, USA, as well as soils from underneath the rocks. DNA from both varnish coatings and soil samples was extracted and subsequently used for metagenomic analysis, as well as for q-PCR analyses for specific species quantification. The element composition of the varnish coatings was analyzed and compared to the soil samples. Rock varnish shows similar depleted elements, compared to soil, but Mn and Pb are 50-60 times enriched compared to the soil samples, and about 100 times enriched compared to the upper continental crust. Our genomic analyses suggest unique populations and different protein functional groups occurring in the varnish compared to soil samples. We discuss these differences and try to shed light on the mechanism of Mn oxyhydroxide production in desert varnish formation.

  4. Integrated network analysis reveals potentially novel molecular mechanisms and therapeutic targets of refractory epilepsies.

    Directory of Open Access Journals (Sweden)

    Hongwei Chu

    Full Text Available Epilepsy is a complex neurological disorder and a significant health problem. The pathogenesis of epilepsy remains obscure in a significant number of patients and the current treatment options are not adequate in about a third of individuals which were known as refractory epilepsies (RE. Network medicine provides an effective approach for studying the molecular mechanisms underlying complex diseases. Here we integrated 1876 disease-gene associations of RE and located those genes to human protein-protein interaction (PPI network to obtain 42 significant RE-associated disease modules. The functional analysis of these disease modules showed novel molecular pathological mechanisms of RE, such as the novel enriched pathways (e.g., "presynaptic nicotinic acetylcholine receptors", "signaling by insulin receptor". Further analysis on the relationships between current drug targets and the RE-related disease genes showed the rational mechanisms of most antiepileptic drugs. In addition, we detected ten potential novel drug targets (e.g., KCNA1, KCNA4-6, KCNC3, KCND2, KCNMA1, CAMK2G, CACNB4 and GRM1 located in three RE related disease modules, which might provide novel insights into the new drug discovery for RE therapy.

  5. Forever Young: Mechanisms of Natural Anoxia Tolerance and Potential Links to Longevity

    Directory of Open Access Journals (Sweden)

    Anastasia Krivoruchko

    2010-01-01

    Full Text Available While mammals cannot survive oxygen deprivation for more than a few minutes without sustaining severe organ damage, some animals have mastered anaerobic life. Freshwater turtles belonging to the Trachemys and Chrysemys genera are the champion facultative anaerobes of the vertebrate world, often surviving without oxygen for many weeks at a time. The physiological and biochemical mechanisms that underlie anoxia tolerance in turtles include profound metabolic rate depression, post-translational modification of proteins, strong antioxidant defenses, activation of specific stress-responsive transcription factors, and enhanced expression of cyto-protective proteins. Turtles are also known for their incredible longevity and display characteristics of “negligible senescence.” We propose that the robust stress-tolerance mechanisms that permit long term anaerobiosis by turtles may also support the longevity of these animals. Many of the mechanisms involved in natural anoxia tolerance, such as hypometabolism or the induction of various protective proteins/pathways, have been shown to play important roles in mammalian oxygen-related diseases and improved understanding of how cells survive without oxygen could aid in the understanding and treatment of various pathological conditions that involve hypoxia or oxidative stress. In the present review we discuss the recent advances made in understanding the molecular nature of anoxia tolerance in turtles and the potential links between this tolerance and longevity.

  6. Study of the 3D Euler equations using Clebsch potentials: dual mechanisms for geometric depletion

    Science.gov (United States)

    Ohkitani, Koji

    2018-02-01

    After surveying analyses of the 3D Euler equations using the Clebsch potentials scattered over the literature, we report some preliminary new results. 1. Assuming that flow fields are free from nulls of the impulse and the vorticity fields, we study how constraints imposed by the Clebsch potentials lead to a degenerate geometrical structure, typically in the form of depletion of nonlinearity. We consider a vorticity surface spanned by \\boldsymbol ω and another material vector \\boldsymbol {W} such that \\boldsymbol γ=\\boldsymbol ω× \\boldsymbol {W}, where \\boldsymbol γ is the impulse variable in geometric gauge. We identify dual mechanism for geometric depletion and show that at least of one them is acting if \\boldsymbol {W} does not develop a null. This suggests that formation of singularity in flows endowed with Clebsch potentials is less likely to happen than in more general flows. Some arguments are given towards exclusion of ‘type I’ blowup. A mathematical challenge remains to rule out singularity formation for flows which have Clebsch potentials everywhere. 2. We exploit classical differential geometry kinematically to write down the Gauss-Weingarten equations for the vorticity surface of the Clebsch potential in terms of fluid dynamical variables, as are the first, second and third fundamental forms. In particular, we derive a constraint on the size of the Gaussian curvature near the point of a possible singularity. On the other hand, an application of the Gauss-Bonnet theorem reveals that the tangential curvature of the surface becomes large in the neighborhood of near-singularity. 3. Using spatially-periodic flows with highly-symmetry, i.e. initial conditions of the Taylor-Green vortex and the Kida-Pelz flow, we present explicit formulas of the Clebsch potentials with exceptional singular surfaces where the Clebsch potentials are undefined. This is done by connecting the known expressions with the solenoidal impulse variable (i.e. the

  7. Potential of wind power projects under the Clean Development Mechanism in India

    Directory of Open Access Journals (Sweden)

    Michaelowa Axel

    2007-07-01

    Full Text Available Abstract Background So far, the cumulative installed capacity of wind power projects in India is far below their gross potential (≤ 15% despite very high level of policy support, tax benefits, long term financing schemes etc., for more than 10 years etc. One of the major barriers is the high costs of investments in these systems. The Clean Development Mechanism (CDM of the Kyoto Protocol provides industrialized countries with an incentive to invest in emission reduction projects in developing countries to achieve a reduction in CO2 emissions at lowest cost that also promotes sustainable development in the host country. Wind power projects could be of interest under the CDM because they directly displace greenhouse gas emissions while contributing to sustainable rural development, if developed correctly. Results Our estimates indicate that there is a vast theoretical potential of CO2 mitigation by the use of wind energy in India. The annual potential Certified Emissions Reductions (CERs of wind power projects in India could theoretically reach 86 million. Under more realistic assumptions about diffusion of wind power projects based on past experiences with the government-run programmes, annual CER volumes by 2012 could reach 41 to 67 million and 78 to 83 million by 2020. Conclusion The projections based on the past diffusion trend indicate that in India, even with highly favorable assumptions, the dissemination of wind power projects is not likely to reach its maximum estimated potential in another 15 years. CDM could help to achieve the maximum utilization potential more rapidly as compared to the current diffusion trend if supportive policies are introduced.

  8. Potential Triggering Mechanisms for the 2006-2007 Half Dome Rockfalls, Yosemite National Park, California

    Science.gov (United States)

    Stock, G. M.

    2007-12-01

    Yosemite Valley is one of the most active areas of rockfall in the world, allowing for detailed examination of individual rockfall events. A rockfall database going back to 1857 reveals that more than half of all documented rockfalls were not associated with a recognizable triggering mechanism. Between July 2006 and June 2007, a series of at least eight rockfalls occurred from a single release point on the Northwest Face of Half Dome in eastern Yosemite Valley. The largest of these rockfalls occurred at 18:46 on July 27th, 2007, and had an approximate volume of 735 m3. Interestingly, all of the rockfalls occurred during the summer (June-August), with no apparent activity at the release point during the winter and spring, typically considered peak seasons for rockfall. In addition to mapping rockfall volumes and the distribution of rock debris, I investigated the geologic and hydrologic factors contributing to failure, including bedrock lithology, degree of weathering, joint density and orientation, and release point geometry. I also analyzed a number of potential rockfall triggering mechanisms, including earthquakes, precipitation, freeze-thaw, and thermal stresses. Although a number of factors contributed to weakening of the rock mass, no specific triggering mechanism(s) can be confidently linked to the rockfalls. Rather, the rockfalls likely resulted from progressive strain weakening of an overhanging arch, with initial small rockfalls destabilizing the rock mass to the point that a large failure occurred. The supposition that summertime rockfalls with unrecognized triggers are unusual has been used to support claims that rockfalls below Glacier Point were caused by wastewater discharges, but the 2006-2007 Half Dome rockfalls, which occurred in a wilderness setting, demonstrate that subtle, even unrecognizable, natural processes trigger summertime rockfalls in Yosemite Valley.

  9. How to make the clean development mechanism sustainable-The potential of rent extraction

    International Nuclear Information System (INIS)

    Muller, Adrian

    2007-01-01

    The clean development mechanism (CDM) should foster sustainable development and greenhouse gas emission reductions. The design of the CDM and first experience suggest that it may not achieve these goals. Developing countries hosting CDM projects may lose cheap emission reduction possibilities for their own future use, and sustainable development and technology transfer may not take place. On the other hand, the CDM has the potential to generate considerable rents if permit prices are high or costs low. To account for equity and distributional issues, a deliberate decision on how to distribute these rents could be taken and the potential failure of the CDM in meeting its goals calls for some further regulation. I suggest to combine these two issues and to extract the rents by a profit tax. Ideally, the tax revenues could contribute to national sustainable development strategies, to offset external costs imposed by CDM projects and to extract part of the resource rent they may generate. The international character of the CDM could offer a frame for internationally coordinated tax design. This would hedge against a potential race to the bottom

  10. Beat-to-beat variability of cardiac action potential duration: underlying mechanism and clinical implications.

    Science.gov (United States)

    Nánási, Péter P; Magyar, János; Varró, András; Ördög, Balázs

    2017-10-01

    Beat-to-beat variability of cardiac action potential duration (short-term variability, SV) is a common feature of various cardiac preparations, including the human heart. Although it is believed to be one of the best arrhythmia predictors, the underlying mechanisms are not fully understood at present. The magnitude of SV is basically determined by the intensity of cell-to-cell coupling in multicellular preparations and by the duration of the action potential (APD). To compensate for the APD-dependent nature of SV, the concept of relative SV (RSV) has been introduced by normalizing the changes of SV to the concomitant changes in APD. RSV is reduced by I Ca , I Kr , and I Ks while increased by I Na , suggesting that ion currents involved in the negative feedback regulation of APD tend to keep RSV at a low level. RSV is also influenced by intracellular calcium concentration and tissue redox potential. The clinical implications of APD variability is discussed in detail.

  11. CO2 emissions mitigation potential of solar home systems under clean development mechanism in India

    International Nuclear Information System (INIS)

    Purohit, Pallav

    2009-01-01

    The Government of India has taken several initiatives for promotion of solar energy systems in the country during the last two decades. A variety of policy measures have been adopted which include provision of financial and fiscal incentives to the potential users of solar energy systems however, only 0.4 million solar home systems (SHSs) have been installed so far that is far below their respective potential. One of the major barriers is the high costs of investments in these systems. The clean development mechanism (CDM) of the Kyoto Protocol provides industrialized (Annex-I) countries with an incentive to invest in emission reduction projects in developing (non-Annex-I) countries to achieve a reduction in carbon dioxide (CO 2 ) emissions at lowest cost that also promotes sustainable development in the host country. SHSs could be of interest under the CDM because they directly displace greenhouse gas (GHG) emissions while contributing to sustainable rural development, if developed correctly. In this study an attempt has been made to estimate the CO 2 mitigation potential of SHSs under CDM in India.

  12. On the Power Spectrum of Motor Unit Action Potential Trains Synchronized With Mechanical Vibration.

    Science.gov (United States)

    Romano, Maria; Fratini, Antonio; Gargiulo, Gaetano D; Cesarelli, Mario; Iuppariello, Luigi; Bifulco, Paolo

    2018-03-01

    This study provides a definitive analysis of the spectrum of a motor unit action potential train (MUAPT) elicited by mechanical vibratory stimulation via a detailed and concise mathematical formulation. Experimental studies demonstrated that MUAPs are not exactly synchronized with the vibratory stimulus but show a variable latency jitter, whose effects have not been investigated yet. Synchronized action potential train was represented as a quasi-periodic sequence of a given MU waveform. The latency jitter of action potentials was modeled as a Gaussian stochastic process, in accordance to the previous experimental studies. A mathematical expression for power spectrum of a synchronized MUAPT has been derived. The spectrum comprises a significant continuous component and discrete components at the vibratory frequency and its harmonics. Their relevance is correlated to the level of synchronization: the weaker the synchronization the more relevant is the continuous spectrum. Electromyography (EMG) rectification enhances the discrete components. The derived equations have general validity and well describe the power spectrum of actual EMG recordings during vibratory stimulation. Results are obtained by appropriately setting the level of synchronization and vibration frequency. This paper definitively clarifies the nature of changes in spectrum of raw EMG recordings from muscles undergoing vibratory stimulation. Results confirm the need of motion artifact filtering for raw EMG recordings during stimulation and strongly suggest to avoid EMG rectification that significantly alters the spectrum characteristics.

  13. Initial sexual maturity and fecundity of the goldfish Carassius auratus (Perciformes: Cyprynidae under semi-controlled conditions

    Directory of Open Access Journals (Sweden)

    A.A Ortega-Salas

    2006-12-01

    Full Text Available We studied the time of initial sexual maturity and the fecundity of the goldfish Carassius auratus under semi-controlled conditions. During the study the water temperature fluctuated from 21 to 30 ºC, the pH between 7 and 8, and the dissolved oxygen between 5.5 and 7 ppm. Sixty days old juvenile fish received prophylactic treatments of brackish water (15 ‰ and methylene blue baths (1 %, and they were fed with live Daphnia magna. The initial sexual maturity occurred between 225 and 233 days of captivity. Mean absolute fecundity was 2 347 (± 302.2 SD ova per gonad, and mean relative fecundity was 63.44 eggs/g fish weight. Gonadosomatic index was between 7.5 and 9.0. Our data will allow ornamental fish producers to calculate the time of initial maturity and fecundity for this species. Rev. Biol. Trop. 54 (4: 1113-1116. Epub 2006 Dec. 15.Estudiamos el tiempo inicial de madurez sexual y la fecundidad del pez dorado Carassius auratus en condiciones semi-controladas. Durante el estudio la temperatura del gua varió de 21 a 30 ºC, el pH entre 7 y 8, y el oxígeno disuelto entre 5.5 y 7 ppm. Jóvenes de 60 días de edad recibieron tratamiento profiláctico con agua salobre (15 ‰, y baños de azul de metileno (1 %. Se les alimentó con Daphnia magna. La madurez sexual inicial fue tras 225 a 233 días en cautiverio. La fecundidad absoluta media fue de 2 347 (±302.2 DS óvulos por gónada y la fecundidad relativa fue de 63.44 óvulos/g del peso del pez. El índice gonadosomático se calculó entre 7.5 and 9.0.

  14. Potential trajectories of the upcoming forest trading mechanism in Pará State, Brazilian Amazon.

    Directory of Open Access Journals (Sweden)

    Brenda Brito

    Full Text Available In 2012, the Brazilian government revised the federal Forest Code that governs the use of forest resources on rural properties. The revisions included a forest trading mechanism whereby landowners who deforested more than what is legally allowed before 2008 could absolve their deforestation "debts" by purchasing Environmental Reserve Quotas (CRA from landowners who conserved more forest than legally required. CRA holds promise as a tool to complement command-and-control initiatives to reduce deforestation and incentivize restoration. However, the success of this instrument depends on how its implementation is governed. This study builds on a few recent assessments of the potential of the CRA in Brazil-but that are focused on biophysical potential-by assessing how a few key implementation decisions may influence the CRA market development. Specifically, this study estimates how decisions on who can participate will likely influence the potential forest surplus and forest debt for the CRA market, and takes into account governance characteristics relevant to the State of Pará, eastern Amazonia. In particular, the study evaluates the effects in the CRA market eligibility after simulating a validation of properties in the environmental rural registry (CAR and assessing different scenarios surrounding land tenure status of properties. Results show how regulatory decisions on CRA market eligibility will determine the extent to which CRA will serve as a tool to support forest conservation or as a low-cost path to help illegal deforesters to comply with legislation, but with limited additional environmental benefits. The study reviews regulatory options that would reduce the risk of forest oversupply, and thereby increase the additionality of the areas eligible for CRA. Overall, the study demonstrates the importance of including governance as well as biophysical characteristics in assessing the potential of forest trading tools to deliver additional

  15. Potential trajectories of the upcoming forest trading mechanism in Pará State, Brazilian Amazon.

    Science.gov (United States)

    Brito, Brenda

    2017-01-01

    In 2012, the Brazilian government revised the federal Forest Code that governs the use of forest resources on rural properties. The revisions included a forest trading mechanism whereby landowners who deforested more than what is legally allowed before 2008 could absolve their deforestation "debts" by purchasing Environmental Reserve Quotas (CRA) from landowners who conserved more forest than legally required. CRA holds promise as a tool to complement command-and-control initiatives to reduce deforestation and incentivize restoration. However, the success of this instrument depends on how its implementation is governed. This study builds on a few recent assessments of the potential of the CRA in Brazil-but that are focused on biophysical potential-by assessing how a few key implementation decisions may influence the CRA market development. Specifically, this study estimates how decisions on who can participate will likely influence the potential forest surplus and forest debt for the CRA market, and takes into account governance characteristics relevant to the State of Pará, eastern Amazonia. In particular, the study evaluates the effects in the CRA market eligibility after simulating a validation of properties in the environmental rural registry (CAR) and assessing different scenarios surrounding land tenure status of properties. Results show how regulatory decisions on CRA market eligibility will determine the extent to which CRA will serve as a tool to support forest conservation or as a low-cost path to help illegal deforesters to comply with legislation, but with limited additional environmental benefits. The study reviews regulatory options that would reduce the risk of forest oversupply, and thereby increase the additionality of the areas eligible for CRA. Overall, the study demonstrates the importance of including governance as well as biophysical characteristics in assessing the potential of forest trading tools to deliver additional environmental

  16. Parenting practices as potential mechanisms for child adjustment following mass trauma.

    Science.gov (United States)

    Gewirtz, Abigail; Forgatch, Marion; Wieling, Elizabeth

    2008-04-01

    Trauma research has identified a link between parental adjustment and children's functioning and the sometimes ensuing intergenerational impact of traumatic events. The effects of traumatic events on children have been demonstrated to be mediated through their impact on children's parents. However, until now, little consideration has been given to the separate and more proximal mechanism of parenting practices as potential mediators between children's adjustment and traumatic events. To shed some light in this arena, we review literature on trauma, adversity, and resilience, and discuss how parenting practices may mediate trauma and adverse environmental contexts. Using a social interaction learning perspective (Forgatch & Knutson, 2002; Patterson, 2005), we propose a prevention research framework to examine the role that parenting practices may play in influencing children's adjustment in the wake of trauma exposure. The article concludes by providing a specific model and role for evidence-based parenting interventions for children exposed to mass trauma.

  17. Hunger and Satiety Mechanisms and Their Potential Exploitation in the Regulation of Food Intake.

    Science.gov (United States)

    Amin, Tehmina; Mercer, Julian G

    2016-03-01

    Effective strategies to combat recent rises in obesity levels are limited. The accumulation of excess body fat results when energy intake exceeds that expended. Energy balance is controlled by hypothalamic responses, but these can be overridden by hedonic/reward brain systems. This override, combined with unprecedented availability of cheap, energy-dense, palatable foods, may partly explain the increase in overweight and obesity. The complexity of the processes that regulate feeding behaviour has driven the need for further fundamental research. Full4Health is an EU-funded project conceived to advance our understanding of hunger and satiety mechanisms. Food intake has an impact on and is also affected by the gut-brain signalling which controls hunger and appetite. This review describes selected recent research from Full4Health and how new mechanistic findings could be exploited to adapt and control our physiological responses to food, potentially providing an alternative solution to addressing the global problems related to positive energy balance.

  18. Thymidylate Limitation Potentiates Cephalosporin Activity toward Enterococci via an Exopolysaccharide-Based Mechanism.

    Science.gov (United States)

    Hoff, Jessica S; Kristich, Christopher J

    2016-06-17

    Multidrug resistant enterococci are major causes of nosocomial infections. Prior therapy with cephalosporins increases the risk of developing an enterococcal infection due to the intrinsic resistance of enterococci to these antibiotics. While progress has been made toward understanding the genetic and biochemical mechanisms of cephalosporin resistance, available data indicate that as-yet-unidentified resistance factors must exist. Here, we describe results of a screen to identify small molecules capable of sensitizing enterococci to broad-spectrum cephalosporins. We found that both Enterococcus faecalis and Enterococcus faecium were sensitized to broad and expanded-spectrum cephalosporins when thymidylate production was impaired, whether by direct inhibition of thymidylate synthase, or by limiting production of cofactors required for its activity. Cephalosporin potentiation is the result of altered exopolysaccharide production due to reduced dTDP-glucose synthesis. Hence, exopolysaccharide production is a previously undescribed contributor to the intrinsic cephalosporin resistance of enterococci and serves as a new target for antienterococcal therapeutics.

  19. Reproductive endocrine-disrupting effects of triclosan: Population exposure, present evidence and potential mechanisms.

    Science.gov (United States)

    Wang, Cai-Feng; Tian, Ying

    2015-11-01

    Triclosan has been used as a broad-spectrum antibacterial agent for over 40 years worldwide. Increasing reports indicate frequent detection and broad exposure to triclosan in the natural environment and the human body. Current laboratory studies in various species provide strong evidence for its disrupting effects on the endocrine system, especially reproductive hormones. Multiple modes of action have been suggested, including disrupting hormone metabolism, displacing hormones from hormone receptors and disrupting steroidogenic enzyme activity. Although epidemiological studies on its effects in humans are mostly negative but conflicting, which is typical of much of the early evidence on the toxicity of EDCs, overall, the evidence suggests that triclosan is an EDC. This article reviews human exposure to triclosan, describes the current evidence regarding its reproductive endocrine-disrupting effects, and discusses potential mechanisms to provide insights for further study on its endocrine-disrupting effects in humans. Copyright © 2015 Elsevier Ltd. All rights reserved.

  20. Inhibition of enzyme activity by nanomaterials: potential mechanisms and implications for nanotoxicity testing.

    Science.gov (United States)

    Maccormack, Tyson J; Clark, Rhett J; Dang, Michael K M; Ma, Guibin; Kelly, Joel A; Veinot, Jonathan G C; Goss, Greg G

    2012-08-01

    The objective of this study was to investigate whether nanoparticle-exposure affects enzyme function and to determine the mechanisms responsible. Silicon, Au, and CdSe nanoparticles were synthesized in house and their physicochemical properties were characterized. The activity of purified lactate dehydrogenase (LDH) was inhibited or abolished by all nanoparticles tested. Inhibition was dependent upon particle core and surface-functional group composition. Inhibition of LDH was absent in crude tissue homogenates, in the presence of albumin, and at the isoelectric point of the protein, indicating that nanoparticles bind non-specifically to abundant proteins via a charge interaction. Circular dichroism spectroscopy suggests that the structure of LDH may be altered by nanoparticles in a manner different from that of bulk controls. We present new data on the specific physicochemical properties of nanoparticles that may lead to bioactivity and highlight a number of potentially serious problems with common nanotoxicity testing methods.

  1. Ti-Ag-Pd alloy with good mechanical properties and high potential for biological applications

    Science.gov (United States)

    Zadorozhnyy, V. Yu.; Shi, X.; Gorshenkov, M. V.; Kozak, D. S.; Wada, T.; Louzguine-Luzgin, D. V.; Inoue, A.; Kato, H.

    2016-04-01

    Ti-based alloys containing Ag were produced by tilt-casting method and their properties were studied. Even in its as-cast state, Ti94Ag3Pd3 showed relatively high tensile properties, good electrochemical behavior, and good biocompatibility. The relatively good mechanical properties of the as-cast α-Ti-type Ti94Ag3Pd3 alloy (tensile strength up to 850 MPa and elongation of ~10%) can be explained by its severely deformed, fine crystalline structure. The high biocompatibility of Ti94Ag3Pd3 can be explained by the Ag-Pd interaction, which inhibits the release of Ag ions from the surface. Ag, in combination with Pd has no toxic effects and demonstrates useful antimicrobial properties. The Ti94Ag3Pd3 alloy shows a good potential to be applied as a biomedical implant alloy.

  2. Smoking and increased Alzheimer’s disease risk: A review of potential mechanisms

    Science.gov (United States)

    Durazzo, Timothy C.; Mattsson, Niklas; Weiner, Michael W.

    2014-01-01

    Background Cigarette smoking has been linked with both increased and decreased risk for Alzheimer’s disease (AD). This is relevant for the US military because the prevalence of smoking in the military is approximately 11% higher than in civilians. Methods Systematic review of published studies on the association between smoking and increased risk for AD, and preclinical and human literature on the relationships between smoking, nicotine exposure and AD-related neuropathology. Original data from comparisons of smoking and never-smoking cognitively normal elders on in vivo amyloid imaging are also presented. Results Overall, the literature indicates that former/active smoking is related to a significantly increased risk for AD. Cigarette smoke/smoking is associated with AD neuropathology in preclinical models and humans. Smoking-related cerebral oxidative stress is a potential mechanism promoting AD pathophysiology and increased risk for AD. Conclusions A reduction in the incidence of smoking will likely reduce the future prevalence of AD. PMID:24924665

  3. Potential protective mechanisms of aryl hydrocarbon receptor (AHR) signaling in benign prostatic hyperplasia

    Science.gov (United States)

    Mehta, Vatsal; Vezina, Chad M.

    2011-01-01

    The aryl hydrocarbon receptor (AHR) is an evolutionarily conserved ligand activated transcription factor best known for its role in mediating toxic responses to dioxin-like environmental contaminants. However, AHR signaling has also emerged as an active participant in processes of normal development and disease progression. Here, we review the role of AHR signaling in prostate development and disease processes, with a particular emphasis on benign prostatic hyperplasia (BPH). Inappropriate AHR activation has recently been associated with a decreased risk of symptomatic BPH in humans and has been shown to impair prostate development and disrupt endocrine signaling in rodents. We highlight known physiological responses to AHR activation in prostate and other tissues and discuss potential mechanisms by which it may act in adult human prostate to protect against symptomatic BPH. PMID:21684673

  4. Mechanisms of radiation interaction with DNA: Potential implications for radiation protection

    Energy Technology Data Exchange (ETDEWEB)

    1988-01-01

    The Office of Health and Environmental Research (OHER) of the US Department of Energy conducts a broad multidisciplinary research program which includes basic biophysics, biophysical chemistry, molecular and cellular biology as well as experimental animal studies and opportunistic human studies. This research is directed at understanding how low levels of radiation of various qualities produce the spectrum of biological effects that are seen for such exposures. This workshop was entitled ''Mechanisms of Radiation Interaction with DNA: Potential Implications for Radiation Protection.'' It ws jointly sponsored by the Department of Energy and the Commission of European Communities. The aim of the workshop was to review the base of knowledge in the area of mechanisms of radiation action at the DNA level, and to explore ways in which this information can be applied to the development of scientifically sound concepts and procedures for use in the field of radiation protection. The overview of research provided by this multidisciplinary group will be helpful to the Office in program planning. This report includes a summary of the presentations, extended abstracts, the meeting agenda, research recommendations, and a list of participants. Individual papers are processed separately for the data base.

  5. Psychological Stress and skin aging: a review of possible mechanisms and potential therapies.

    Science.gov (United States)

    Dunn, Jeffrey H; Koo, John

    2013-06-15

    The link between psychological stress and aging is intuitive although the underlying mechanisms are not well defined. Evidence suggests that chronic psychological stress stimulates the autonomic nervous system, renin-angiotensin system, and the hypothalamic-pituitary-adrenal axis when the body attempts to resolve perceived threats to homeostasis. Prolonged activation of these pathways can result in chronic immune dysfunction, increased production of reactive oxygen species, and DNA damage, which are known to contribute to the again of skin and other tissues. Despite the lack of conclusive evidence directly linking psychological stress to skin aging, mechanisms by which stress leads to immune dysfunction, oxidative radicals, and ultimately DNA damage via neuronal, endocrine, and immune modulation may present a possible intervention for skin aging. In addition to the wide array of anti-oxidant therapies being developed to combat aging, the topical use of beta-blockers such as timolol, angiotensin receptor blockers such as valsartan, glucocorticoid blockers such as mifepristone, and cholinergic modulators including botulinum toxin, might be potential therapeutic strategies to prevent skin aging. Given the current understanding of these pathways, it would be premature to utilize such modalities for prevention of skin aging at this time, but future research into this type of topical pharmacologic anti-aging intervention may be promising.

  6. Mechanisms of radiation interaction with DNA: Potential implications for radiation protection

    International Nuclear Information System (INIS)

    1988-01-01

    The Office of Health and Environmental Research (OHER) of the US Department of Energy conducts a broad multidisciplinary research program which includes basic biophysics, biophysical chemistry, molecular and cellular biology as well as experimental animal studies and opportunistic human studies. This research is directed at understanding how low levels of radiation of various qualities produce the spectrum of biological effects that are seen for such exposures. This workshop was entitled ''Mechanisms of Radiation Interaction with DNA: Potential Implications for Radiation Protection.'' It ws jointly sponsored by the Department of Energy and the Commission of European Communities. The aim of the workshop was to review the base of knowledge in the area of mechanisms of radiation action at the DNA level, and to explore ways in which this information can be applied to the development of scientifically sound concepts and procedures for use in the field of radiation protection. The overview of research provided by this multidisciplinary group will be helpful to the Office in program planning. This report includes a summary of the presentations, extended abstracts, the meeting agenda, research recommendations, and a list of participants. Individual papers are processed separately for the data base

  7. Potential mechanisms underlying anxiety and depression in Parkinson's disease: consequences of L-DOPA treatment

    Science.gov (United States)

    Eskow Jaunarajs, Karen L.; Angoa-Perez, Mariana; Kuhn, Donald M.; Bishop, Christopher

    2010-01-01

    Though the most recognizable symptoms of Parkinson's disease (PD) are motor-related, many patients also suffer from debilitating affective symptoms that deleteriously influence quality of life. Dopamine (DA) loss is likely involved in the onset of depression and anxiety in PD. However, these symptoms are not reliably improved by DA replacement therapy with L-3,4-dihydroxyphenylalanine (L-DOPA). In fact, preclinical and clinical evidence suggests that L-DOPA treatment may worsen affect. Though the neurobiological mechanisms remain unclear, recent research contends that L-DOPA further perturbs the function of the norepinephrine and serotonin systems, already affected by PD pathology, which have been intimately linked to the development and expression of anxiety and depression. As such, this review provides an overview of the clinical characteristics of affective disorders in PD, examines the utility of animal models for the study of anxiety and depression in PD, and finally, discusses potential mechanisms by which DA loss and subsequent L-DOPA therapy influence monoamine function and concomitant affective symptoms. PMID:20615430

  8. Benefits of Nut Consumption on Insulin Resistance and Cardiovascular Risk Factors: Multiple Potential Mechanisms of Actions

    Directory of Open Access Journals (Sweden)

    Yoona Kim

    2017-11-01

    Full Text Available Epidemiological and clinical studies have indicated that nut consumption could be a healthy dietary strategy to prevent and treat type 2 diabetes (T2DM and related cardiovascular disease (CVD. The objective of this review is to examine the potential mechanisms of action of nuts addressing effects on glycemic control, weight management, energy balance, appetite, gut microbiota modification, lipid metabolism, oxidative stress, inflammation, endothelial function and blood pressure with a focus on data from both animal and human studies. The favourable effects of nuts could be explained by the unique nutrient composition and bioactive compounds in nuts. Unsaturated fatty acids (monounsaturated fatty acids and polyunsaturated fatty acids present in nuts may play a role in glucose control and appetite suppression. Fiber and polyphenols in nuts may also have an anti-diabetic effect by altering gut microbiota. Nuts lower serum cholesterol by reduced cholesterol absorption, inhibition of HMG-CoA reductase and increased bile acid production by stimulation of 7-α hydroxylase. Arginine and magnesium improve inflammation, oxidative stress, endothelial function and blood pressure. In conclusion, nuts contain compounds that favourably influence glucose homeostasis, weight control and vascular health. Further investigations are required to identify the most important mechanisms by which nuts decrease the risk of T2DM and CVD.

  9. Potentially dangerous fih of the Paraiba Estuary: Identifiation and envenomation mechanisms

    Directory of Open Access Journals (Sweden)

    Anderson Kelvin Saraiva Macêdo

    2017-11-01

    Full Text Available Objective: To present venomous and poisonous fish species in the Paraiba Estuary, Paraiba State, Brazil, with a description of the envenomation mechanisms and characteristics of the toxins. Methods: Fishes were caught by beach seine in the dry and rainy season (November 2013 and June 2014 and bimonthly between May 2016 and March 2017. Results: Eight potentially dangerous species belonging to the families Batrachoididae, Ariidae and Tetraodontidae were identified. The representatives of the former two families, toadfish and catfish, respectively had specific venom inoculating apparatuses that could penetrate tissues, releasing toxins that caused injuries mainly to fishermen. The family Tetraodontidae had poisonous species, once the pufferfish could accumulate biotoxins (especially tetrodotoxin, which is a neurotoxin produced by bacteria. Despite being toxic for consumption, these fish were often consumed by fishermen and their families. Conclusions: The present study is the first record of venomous and poisonous species in the Paraiba Estuary and contributes to the knowledge of the identification of the species and the mechanisms that cause severe envenomation and even deaths in artisanal fishing communities. Such knowledge is fundamental to future campaigns aimed at the prevention of injuries involving fish in the region and in other estuarine environments, where such fishes are common.

  10. The Anticonvulsant Effects of Ketogenic Diet on Epileptic Seizures and Potential Mechanisms.

    Science.gov (United States)

    Zhang, Yifan; Xu, Jingwei; Zhang, Kun; Yang, Wei; Li, Bingjin

    2018-01-01

    Epilepsy is a syndrome of brain dysfunction induced by the aberrant excitability of certain neurons. Despite advances in surgical technique and anti-epileptic drug in recent years, recurrent epileptic seizures remain intractable and lead to a serious morbidity in the world. The ketogenic diet refers to a high-fat, low-carbohydrate and adequate-protein diet. Currently, its beneficial effects on epileptic seizure reduction have been well established. However, the detailed mechanisms underlying the anti-epileptic effects of ketogenic diet are still poorly understood. In this article, the possible roles of ketogenic diet on epilepsy were discussed. Data was obtained from the websites including Web of Science, Medline, Pubmed, Scopus, based on these keywords: "Ketogenic diet" and "epilepsy". As shown in both clinical and basic studies, the therapeutic effects of ketogenic diet might involve neuronal metabolism, neurotransmitter function, neuronal membrane potential and neuron protection against ROS. In this review, we systematically reviewed the effects and possible mechanisms of ketogenic diet on epilepsy, which may optimize the therapeutic strategies against epilepsy. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

  11. Limb Remote Ischemic Conditioning: Mechanisms, Anesthetics, and the Potential for Expanding Therapeutic Options

    Directory of Open Access Journals (Sweden)

    Gangling Chen

    2018-02-01

    Full Text Available Novel and innovative approaches are essential in developing new treatments and improving clinical outcomes in patients with ischemic stroke. Remote ischemic conditioning (RIC is a series of mechanical interruptions in blood flow of a distal organ, following end organ reperfusion, shown to significantly reduce infarct size through inhibition of oxidation and inflammation. Ischemia/reperfusion (I/R is what ultimately leads to the irreversible brain damage and clinical picture seen in stroke patients. There have been several reports and reviews about the potential of RIC in acute ischemic stroke; however, the focus here is a comprehensive look at the differences in the three types of RIC (remote pre-, per-, and postconditioning. There are some limited uses of preconditioning in acute ischemic stroke due to the unpredictability of the ischemic event; however, it does provide the identification of biomarkers for clinical studies. Remote limb per- and postconditioning offer a more promising treatment during patient care as they can be harnessed during or after the initial ischemic insult. Though further research is needed, it is imperative to discuss the importance of preclinical data in understanding the methods and mechanisms involved in RIC. This understanding will facilitate translation to a clinically feasible paradigm for use in the hospital setting.

  12. Limb Remote Ischemic Conditioning: Mechanisms, Anesthetics, and the Potential for Expanding Therapeutic Options

    Science.gov (United States)

    Chen, Gangling; Thakkar, Mrugesh; Robinson, Christopher; Doré, Sylvain

    2018-01-01

    Novel and innovative approaches are essential in developing new treatments and improving clinical outcomes in patients with ischemic stroke. Remote ischemic conditioning (RIC) is a series of mechanical interruptions in blood flow of a distal organ, following end organ reperfusion, shown to significantly reduce infarct size through inhibition of oxidation and inflammation. Ischemia/reperfusion (I/R) is what ultimately leads to the irreversible brain damage and clinical picture seen in stroke patients. There have been several reports and reviews about the potential of RIC in acute ischemic stroke; however, the focus here is a comprehensive look at the differences in the three types of RIC (remote pre-, per-, and postconditioning). There are some limited uses of preconditioning in acute ischemic stroke due to the unpredictability of the ischemic event; however, it does provide the identification of biomarkers for clinical studies. Remote limb per- and postconditioning offer a more promising treatment during patient care as they can be harnessed during or after the initial ischemic insult. Though further research is needed, it is imperative to discuss the importance of preclinical data in understanding the methods and mechanisms involved in RIC. This understanding will facilitate translation to a clinically feasible paradigm for use in the hospital setting. PMID:29467715

  13. Phytoremediation potential of the novel atrazine tolerant Lolium multiflorum and studies on the mechanisms involved

    Energy Technology Data Exchange (ETDEWEB)

    Merini, Luciano J. [Catedra de Microbiologia Industrial y Biotecnologia, Universidad de Buenos Aires (Argentina); Bobillo, Cecilia [Servicio de Huellas Digitales Geneticas, Facultad de Farmacia y Bioquimica, Microbiologia Industrial y Biotecnologia, Universidad de Buenos Aires, Junin 956, BS As (Argentina); Cuadrado, Virginia [Catedra de Microbiologia Industrial y Biotecnologia, Universidad de Buenos Aires (Argentina); Corach, Daniel [Servicio de Huellas Digitales Geneticas, Facultad de Farmacia y Bioquimica, Microbiologia Industrial y Biotecnologia, Universidad de Buenos Aires, Junin 956, BS As (Argentina); Giulietti, Ana M., E-mail: agiule@ffyb.uba.a [Catedra de Microbiologia Industrial y Biotecnologia, Universidad de Buenos Aires (Argentina)

    2009-11-15

    Atrazine impact on human health and the environment have been extensively studied. Phytoremediation emerged as a low cost, environmental friendly biotechnological solution for atrazine pollution in soil and water. In vitro atrazine tolerance assays were performed and Lolium multiflorum was found as a novel tolerant species, able to germinate and grow in the presence of 1 mg kg{sup -1} of the herbicide. L. multiflorum presented 20% higher atrazine removal capacity than the natural attenuation, with high initial degradation rate in microcosms. The mechanisms involved in atrazine tolerance such as mutation in psbA gene, enzymatic detoxification via P{sub 450} or chemical hydrolysis through benzoxazinones were evaluated. It was demonstrated that atrazine tolerance is conferred by enhanced enzymatic detoxification via P{sub 450}. Due to its atrazine degradation capacity in soil and its agronomical properties, L. multiflorum is a candidate for designing phytoremediation strategies for atrazine contaminated agricultural soils, especially those involving run-off avoiding. - Finding of a novel atrazine-tolerant species, as a potential candidate for phytoremediating herbicide-contaminated agriculture soils and elucidation of the mechanisms involved in tolerance.

  14. Phytoremediation potential of the novel atrazine tolerant Lolium multiflorum and studies on the mechanisms involved

    International Nuclear Information System (INIS)

    Merini, Luciano J.; Bobillo, Cecilia; Cuadrado, Virginia; Corach, Daniel; Giulietti, Ana M.

    2009-01-01

    Atrazine impact on human health and the environment have been extensively studied. Phytoremediation emerged as a low cost, environmental friendly biotechnological solution for atrazine pollution in soil and water. In vitro atrazine tolerance assays were performed and Lolium multiflorum was found as a novel tolerant species, able to germinate and grow in the presence of 1 mg kg -1 of the herbicide. L. multiflorum presented 20% higher atrazine removal capacity than the natural attenuation, with high initial degradation rate in microcosms. The mechanisms involved in atrazine tolerance such as mutation in psbA gene, enzymatic detoxification via P 450 or chemical hydrolysis through benzoxazinones were evaluated. It was demonstrated that atrazine tolerance is conferred by enhanced enzymatic detoxification via P 450 . Due to its atrazine degradation capacity in soil and its agronomical properties, L. multiflorum is a candidate for designing phytoremediation strategies for atrazine contaminated agricultural soils, especially those involving run-off avoiding. - Finding of a novel atrazine-tolerant species, as a potential candidate for phytoremediating herbicide-contaminated agriculture soils and elucidation of the mechanisms involved in tolerance.

  15. Mechanism of Bacterial Inactivation by (+)-Limonene and Its Potential Use in Food Preservation Combined Processes

    Science.gov (United States)

    Espina, Laura; Gelaw, Tilahun K.; de Lamo-Castellví, Sílvia; Pagán, Rafael; García-Gonzalo, Diego

    2013-01-01

    This work explores the bactericidal effect of (+)-limonene, the major constituent of citrus fruits' essential oils, against E. coli. The degree of E. coli BJ4 inactivation achieved by (+)-limonene was influenced by the pH of the treatment medium, being more bactericidal at pH 4.0 than at pH 7.0. Deletion of rpoS and exposure to a sub-lethal heat or an acid shock did not modify E. coli BJ4 resistance to (+)-limonene. However, exposure to a sub-lethal cold shock decreased its resistance to (+)-limonene. Although no sub-lethal injury was detected in the cell envelopes after exposure to (+)-limonene by the selective-plating technique, the uptake of propidium iodide by inactivated E. coli BJ4 cells pointed out these structures as important targets in the mechanism of action. Attenuated Total Reflectance Infrared Microspectroscopy (ATR-IRMS) allowed identification of altered E. coli BJ4 structures after (+)-limonene treatments as a function of the treatment pH: β-sheet proteins at pH 4.0 and phosphodiester bonds at pH 7.0. The increased sensitivity to (+)-limonene observed at pH 4.0 in an E. coli MC4100 lptD4213 mutant with an increased outer membrane permeability along with the identification of altered β-sheet proteins by ATR-IRMS indicated the importance of this structure in the mechanism of action of (+)-limonene. The study of mechanism of inactivation by (+)-limonene led to the design of a synergistic combined process with heat for the inactivation of the pathogen E. coli O157:H7 in fruit juices. These results show the potential of (+)-limonene in food preservation, either acting alone or in combination with lethal heat treatments. PMID:23424676

  16. Mechanism of bacterial inactivation by (+-limonene and its potential use in food preservation combined processes.

    Directory of Open Access Journals (Sweden)

    Laura Espina

    Full Text Available This work explores the bactericidal effect of (+-limonene, the major constituent of citrus fruits' essential oils, against E. coli. The degree of E. coli BJ4 inactivation achieved by (+-limonene was influenced by the pH of the treatment medium, being more bactericidal at pH 4.0 than at pH 7.0. Deletion of rpoS and exposure to a sub-lethal heat or an acid shock did not modify E. coli BJ4 resistance to (+-limonene. However, exposure to a sub-lethal cold shock decreased its resistance to (+-limonene. Although no sub-lethal injury was detected in the cell envelopes after exposure to (+-limonene by the selective-plating technique, the uptake of propidium iodide by inactivated E. coli BJ4 cells pointed out these structures as important targets in the mechanism of action. Attenuated Total Reflectance Infrared Microspectroscopy (ATR-IRMS allowed identification of altered E. coli BJ4 structures after (+-limonene treatments as a function of the treatment pH: β-sheet proteins at pH 4.0 and phosphodiester bonds at pH 7.0. The increased sensitivity to (+-limonene observed at pH 4.0 in an E. coli MC4100 lptD4213 mutant with an increased outer membrane permeability along with the identification of altered β-sheet proteins by ATR-IRMS indicated the importance of this structure in the mechanism of action of (+-limonene. The study of mechanism of inactivation by (+-limonene led to the design of a synergistic combined process with heat for the inactivation of the pathogen E. coli O157:H7 in fruit juices. These results show the potential of (+-limonene in food preservation, either acting alone or in combination with lethal heat treatments.

  17. Formation mechanism of self-potential at ISL-amenable interlayer oxidation zone sandstone-type uranium deposit and the simulation and application of self-potential anomalies

    International Nuclear Information System (INIS)

    Tang Hongzhi; Liu Qingcheng; Su Zhaofeng; Gong Yuling

    2006-01-01

    Based on the analysis of geochemical characteristics and metallogenic physico-chemical conditions of ISL-amenable sandstone-type uranium deposits, the formation mechanism of self-potential field is discussed, a mathematic calculation model has been set up, and the simulation calculation has been performed for self-potential anomalies above uranium ore bodies of ordinary form, features of survey curve are analysed and methods for correcting topography at self-potential anomalies are discussed, and a simulation curve of self-potential in the area of slope topography has been presented. Finally, the availability of the method is demonstrated by an example. (authors)

  18. Disrupting mycorrhizal mutualisms: a potential mechanism by which exotic tamarisk outcompetes native cottonwoods.

    Science.gov (United States)

    Meinhardt, Kelley A; Gehring, Catherine A

    2012-03-01

    The disruption of mutualisms between plants and mycorrhizal fungi is a potentially powerful mechanism by which invasives can negatively impact native species, yet our understanding of this mechanism's role in exotic species invasion is still in its infancy. Here, we provide several lines of evidence indicating that invasive tamarisk (Tamarix sp.) negatively affects native cottonwoods (Populus fremontii) by disrupting their associations with arbuscular mycorrhizal (AM) and ectomycorrhizal (EM) fungi. At a field site in the early stages of tamarisk invasion, cottonwoods with tamarisk neighbors had reduced EM colonization and altered EM fungal community composition relative to cottonwoods with native neighbors, leading to reductions in EM propagule abundance in the soil beneath tamarisk. Similarly, AM colonization of cottonwoods was reduced with a tamarisk neighbor, but there were no significant changes in AM fungal spore communities or propagule abundance. Root colonization by nonmycorrhizal fungi, including potential pathogens, was higher in cottonwoods with tamarisk neighbors. A greenhouse experiment in which AM and EM inoculation and plant neighbor were manipulated in a fully factorial design showed that cottonwoods benefited from mycorrhizas, especially EM, in terms of shoot biomass when grown with a conspecific, but shoot biomass was similar to that of nonmycorrhizal controls when cottonwoods were grown with a tamarisk neighbor. These results are partially explained by a reduction in EM but not AM colonization of cottonwoods by a tamarisk neighbor. Tamarisk neighbors negatively affected cottonwood specific leaf area, but not chlorophyll content, in the field. To pinpoint a mechanism for these changes, we measured soil chemistry in the field and the growth response of an EM fungus (Hebeloma crustuliniforme) to salt-amended media in the laboratory. Tamarisk increased both NO3- concentrations and electrical conductivity 2.5-fold beneath neighboring cottonwoods in

  19. Potential Mechanisms for Cancer Resistance in Elephants and Comparative Cellular Response to DNA Damage in Humans.

    Science.gov (United States)

    Abegglen, Lisa M; Caulin, Aleah F; Chan, Ashley; Lee, Kristy; Robinson, Rosann; Campbell, Michael S; Kiso, Wendy K; Schmitt, Dennis L; Waddell, Peter J; Bhaskara, Srividya; Jensen, Shane T; Maley, Carlo C; Schiffman, Joshua D

    2015-11-03

    Evolutionary medicine may provide insights into human physiology and pathophysiology, including tumor biology. To identify mechanisms for cancer resistance in elephants and compare cellular response to DNA damage among elephants, healthy human controls, and cancer-prone patients with Li-Fraumeni syndrome (LFS). A comprehensive survey of necropsy data was performed across 36 mammalian species to validate cancer resistance in large and long-lived organisms, including elephants (n = 644). The African and Asian elephant genomes were analyzed for potential mechanisms of cancer resistance. Peripheral blood lymphocytes from elephants, healthy human controls, and patients with LFS were tested in vitro in the laboratory for DNA damage response. The study included African and Asian elephants (n = 8), patients with LFS (n = 10), and age-matched human controls (n = 11). Human samples were collected at the University of Utah between June 2014 and July 2015. Ionizing radiation and doxorubicin. Cancer mortality across species was calculated and compared by body size and life span. The elephant genome was investigated for alterations in cancer-related genes. DNA repair and apoptosis were compared in elephant vs human peripheral blood lymphocytes. Across mammals, cancer mortality did not increase with body size and/or maximum life span (eg, for rock hyrax, 1% [95% CI, 0%-5%]; African wild dog, 8% [95% CI, 0%-16%]; lion, 2% [95% CI, 0%-7%]). Despite their large body size and long life span, elephants remain cancer resistant, with an estimated cancer mortality of 4.81% (95% CI, 3.14%-6.49%), compared with humans, who have 11% to 25% cancer mortality. While humans have 1 copy (2 alleles) of TP53, African elephants have at least 20 copies (40 alleles), including 19 retrogenes (38 alleles) with evidence of transcriptional activity measured by reverse transcription polymerase chain reaction. In response to DNA damage, elephant lymphocytes underwent p53-mediated apoptosis

  20. Sex hormones and adult hippocampal neurogenesis: Regulation, implications, and potential mechanisms.

    Science.gov (United States)

    Mahmoud, Rand; Wainwright, Steven R; Galea, Liisa A M

    2016-04-01

    Neurogenesis within the adult hippocampus is modulated by endogenous and exogenous factors. Here, we review the role of sex hormones in the regulation of adult hippocampal neurogenesis in males and females. The review is framed around the potential functional implications of sex hormone regulation of adult hippocampal neurogenesis, with a focus on cognitive function and mood regulation, which may be related to sex differences in incidence and severity of dementia and depression. We present findings from preclinical studies of endogenous fluctuations in sex hormones relating to reproductive function and ageing, and from studies of exogenous hormone manipulations. In addition, we discuss the modulating roles of sex, age, and reproductive history on the relationship between sex hormones and neurogenesis. Because sex hormones have diverse targets in the central nervous system, we overview potential mechanisms through which sex hormones may influence hippocampal neurogenesis. Lastly, we advocate for a more systematic consideration of sex and sex hormones in studying the functional implications of adult hippocampal neurogenesis. Copyright © 2016 Elsevier Inc. All rights reserved.

  1. Application potential of grapefruit peel as dye sorbent: Kinetics, equilibrium and mechanism of crystal violet adsorption

    International Nuclear Information System (INIS)

    Saeed, Asma; Sharif, Mehwish; Iqbal, Muhammad

    2010-01-01

    This study reports the sorption of crystal violet (CV) dye by grapefruit peel (GFP), which has application potential in the remediation of dye-contaminated wastewaters using a solid waste generated by the citrus fruit juice industry. Batch adsorption of CV was conducted to evaluate the effect of initial pH, contact time, temperature, initial dye concentration, GFP adsorbent dose, and removal of the adsorbate CV dye from aqueous solution to understand the mechanism of sorption involved. Sorption equilibrium reached rapidly with 96% CV removal in 60 min. Fit of the sorption experimental data was tested on the pseudo-first and pseudo-second-order kinetics mathematical equations, which was noted to follow the pseudo-second-order kinetics better, with coefficient of correlation ≥0.992. The equilibrium process was well described by the Langmuir isotherm model, with maximum sorption capacity of 254.16 mg g -1 . The GFP was regenerated using 1 M NaOH, with up to 98.25% recovery of CV and could be reused as a dye sorbent in repeated cycles. GFP was also shown to be highly effective in removing CV from aqueous solution in continuous-flow fixed-bed column reactors. The study shows that GFP has the potential of application as an efficient sorbent for the removal of CV from aqueous solutions.

  2. A look at the possible mechanism and potential of magneto therapy.

    Science.gov (United States)

    Jacobson, J I

    1991-03-07

    A testable theoretical model for the mechanism of magneto-therapy is presented. The theory delineated is the equation mc2 = Bvl coulomb which sets in dual resonance gravitational and electromagnetic potentials. This proposed unification of Einstein's gravity and Maxwell's electromagnetism is designated Jacobson's resonance and is a general expression of Zeeman and cyclotron resonance. The application of this theory involves the utilization of exogenously sourced very weak magnetic fields on the order of magnitude 10(-8) gauss to reorient the atomic crystal lattice structures of genomic magnetic domains. Examples of genomic magnetic domains are homeoboxes and oncogenes and associated structures like peptide hormone trophic factors. Various phenomena are also analyzed in terms of how they may relate to biological systems such as solitons, phonons, cyclotron resonance, the piezoelectric effect, the fractional quantum Hall effect, string theory, and biologically closed electric circuits. The potential of magneto-therapy in the treatment of various genomic and associated disorders is explored. The ultimate question "Can an oncogene be electromagnetically induced into becoming a structurally homologous normal gene?" is posed.

  3. Physical activity and telomere length: Impact of aging and potential mechanisms of action.

    Science.gov (United States)

    Arsenis, Nicole C; You, Tongjian; Ogawa, Elisa F; Tinsley, Grant M; Zuo, Li

    2017-07-04

    Telomeres protect the integrity of information-carrying DNA by serving as caps on the terminal portions of chromosomes. Telomere length decreases with aging, and this contributes to cell senescence. Recent evidence supports that telomere length of leukocytes and skeletal muscle cells may be positively associated with healthy living and inversely correlated with the risk of several age-related diseases, including cancer, cardiovascular disease, obesity, diabetes, chronic pain, and stress. In observational studies, higher levels of physical activity or exercise are related to longer telomere lengths in various populations, and athletes tend to have longer telomere lengths than non-athletes. This relationship is particularly evident in older individuals, suggesting a role of physical activity in combating the typical age-induced decrements in telomere length. To date, a small number of exercise interventions have been executed to examine the potential influence of chronic exercise on telomere length, but these studies have not fully established such relationship. Several potential mechanisms through which physical activity or exercise could affect telomere length are discussed, including changes in telomerase activity, oxidative stress, inflammation, and decreased skeletal muscle satellite cell content. Future research is needed to mechanistically examine the effects of various modalities of exercise on telomere length in middle-aged and older adults, as well as in specific clinical populations.

  4. Vitamin D as an adjunctive therapy in asthma. Part 1: A review of potential mechanisms.

    LENUS (Irish Health Repository)

    Kerley, Conor P

    2015-02-27

    Vitamin D deficiency (VDD) is highly prevlalent worldwide. The classical role for vitamin D is to regulate calcium absorption form the gastrointestinal tract and influence bone health. Recently vitamin D receptors and vitamin D metabolic enzymes have been discovered in numerous sites systemically supporting diverse extra-skeletal roles of vitamin D, for example in asthmatic disease. Further, VDD and asthma share several common risk factors including high latitude, winter season, industrialization, poor diet, obesity, and dark skin pigmentation. Vitamin D has been demonstrated to possess potent immunomodulatory effects, including effects on T cells and B cells as well as increasing production of antimicrobial peptides (e.g. cathelicidin). This immunomodulation may lead to asthma specific clinical benefits in terms of decreased bacterial\\/viral infections, altered airway smooth muscle-remodeling and -function as well as modulation of response to standard anti-asthma therapy (e.g. glucocorticoids and immunotherapy). Thus, vitamin D and its deficiency have a number of biological effects that are potentially important in altering the course of disease pathogenesis and severity in asthma. The purpose of this first of a two-part review is to review potential mechanisms whereby altering vitamin D status may influence asthmatic disease.

  5. Honey as a Potential Natural Antioxidant Medicine: An Insight into Its Molecular Mechanisms of Action

    Science.gov (United States)

    Ahmed, Sarfraz; Sulaiman, Siti Amrah; Baig, Atif Amin; Ibrahim, Muhammad; Liaqat, Sana; Fatima, Saira; Jabeen, Sadia; Shamim, Nighat

    2018-01-01

    Honey clasps several medicinal and health effects as a natural food supplement. It has been established as a potential therapeutic antioxidant agent for various biodiverse ailments. Data report that it exhibits strong wound healing, antibacterial, anti-inflammatory, antifungal, antiviral, and antidiabetic effects. It also retains immunomodulatory, estrogenic regulatory, antimutagenic, anticancer, and numerous other vigor effects. Data also show that honey, as a conventional therapy, might be a novel antioxidant to abate many of the diseases directly or indirectly associated with oxidative stress. In this review, these wholesome effects have been thoroughly reviewed to underscore the mode of action of honey exploring various possible mechanisms. Evidence-based research intends that honey acts through a modulatory road of multiple signaling pathways and molecular targets. This road contemplates through various pathways such as induction of caspases in apoptosis; stimulation of TNF-α, IL-1β, IFN-γ, IFNGR1, and p53; inhibition of cell proliferation and cell cycle arrest; inhibition of lipoprotein oxidation, IL-1, IL-10, COX-2, and LOXs; and modulation of other diverse targets. The review highlights the research done as well as the apertures to be investigated. The literature suggests that honey administered alone or as adjuvant therapy might be a potential natural antioxidant medicinal agent warranting further experimental and clinical research. PMID:29492183

  6. Vitiligo blood transcriptomics provides new insights into disease mechanisms and identifies potential novel therapeutic targets.

    Science.gov (United States)

    Dey-Rao, Rama; Sinha, Animesh A

    2017-01-28

    Significant gaps remain regarding the pathomechanisms underlying the autoimmune response in vitiligo (VL), where the loss of self-tolerance leads to the targeted killing of melanocytes. Specifically, there is incomplete information regarding alterations in the systemic environment that are relevant to the disease state. We undertook a genome-wide profiling approach to examine gene expression in the peripheral blood of VL patients and healthy controls in the context of our previously published VL-skin gene expression profile. We used several in silico bioinformatics-based analyses to provide new insights into disease mechanisms and suggest novel targets for future therapy. Unsupervised clustering methods of the VL-blood dataset demonstrate a "disease-state"-specific set of co-expressed genes. Ontology enrichment analysis of 99 differentially expressed genes (DEGs) uncovers a down-regulated immune/inflammatory response, B-Cell antigen receptor (BCR) pathways, apoptosis and catabolic processes in VL-blood. There is evidence for both type I and II interferon (IFN) playing a role in VL pathogenesis. We used interactome analysis to identify several key blood associated transcriptional factors (TFs) from within (STAT1, STAT6 and NF-kB), as well as "hidden" (CREB1, MYC, IRF4, IRF1, and TP53) from the dataset that potentially affect disease pathogenesis. The TFs overlap with our reported lesional-skin transcriptional circuitry, underscoring their potential importance to the disease. We also identify a shared VL-blood and -skin transcriptional "hot spot" that maps to chromosome 6, and includes three VL-blood dysregulated genes (PSMB8, PSMB9 and TAP1) described as potential VL-associated genetic susceptibility loci. Finally, we provide bioinformatics-based support for prioritizing dysregulated genes in VL-blood or skin as potential therapeutic targets. We examined the VL-blood transcriptome in context with our (previously published) VL-skin transcriptional profile to address

  7. Nanoscale copper in the soil–plant system – toxicity and underlying potential mechanisms

    Energy Technology Data Exchange (ETDEWEB)

    Anjum, Naser A., E-mail: anjum@ua.pt [CESAM-Centre for Environmental and Marine Studies & Department of Chemistry, University of Aveiro, 3810-193 Aveiro (Portugal); Adam, Vojtech [Department of Chemistry and Biochemistry, Faculty of Agronomy, Mendel University in Brno, Zemedelska 1, CZ-613 00 Brno (Czech Republic); Central European Institute of Technology, Brno University of Technology, Technicka 3058/10, CZ-616 00 Brno (Czech Republic); Kizek, Rene [Central European Institute of Technology, Brno University of Technology, Technicka 3058/10, CZ-616 00 Brno (Czech Republic); Duarte, Armando C.; Pereira, Eduarda [CESAM-Centre for Environmental and Marine Studies & Department of Chemistry, University of Aveiro, 3810-193 Aveiro (Portugal); Iqbal, Muhammad [Department of Botany, Faculty of Science, Hamdard University, New Delhi 110062 (India); Lukatkin, Alexander S. [Department of Botany, Plant Physiology and Ecology, N.P. Ogarev Mordovia State University, Bolshevistskaja Str., 68. Saransk 430005 (Russian Federation); Ahmad, Iqbal, E-mail: ahmadr@ua.pt [CESAM-Centre for Environmental and Marine Studies & Department of Chemistry, University of Aveiro, 3810-193 Aveiro (Portugal); CESAM-Centre for Environmental and Marine Studies & Department of Biology, University of Aveiro, 3810-193 Aveiro (Portugal)

    2015-04-15

    Nanoscale copper particles (nano-Cu) are used in many antimicrobial formulations and products for their antimicrobial activity. They may enter deliberately and/or accidentally into terrestrial environments including soils. Being the major ‘eco-receptors’ of nanoscale particles in the terrestrial ecosystem, soil–microbiota and plants (the soil–plant system) have been used as a model to dissect the potential impact of these particles on the environmental and human health. In the soil–plant system, the plant can be an indirect non-target organism of the soil-associated nano-Cu that may in turn affect plant-based products and their consumers. By all accounts, information pertaining to nano-Cu toxicity and the underlying potential mechanisms in the soil–plant system remains scanty, deficient and little discussed. Therefore, based on some recent reports from (bio)chemical, molecular and genetic studies of nano-Cu versus soil–plant system, this article: (i) overviews the status, chemistry and toxicity of nano-Cu in soil and plants, (ii) discusses critically the poorly understood potential mechanisms of nano-Cu toxicity and tolerance both in soil–microbiota and plants, and (iii) proposes future research directions. It appears from studies hitherto made that the uncontrolled generation and inefficient metabolism of reactive oxygen species through different reactions are the major factors underpinning the overall nano-Cu consequences in both the systems. However, it is not clear whether the nano-Cu or the ion released from it is the cause of the toxicity. We advocate to intensify the multi-approach studies focused at a complete characterization of the nano-Cu, its toxicity (during life cycles of the least-explored soil–microbiota and plants), and behavior in an environmentally relevant terrestrial exposure setting. Such studies may help to obtain a deeper insight into nano-Cu actions and address adequately the nano-Cu-associated safety concerns in the

  8. Whitings as a Potential Mechanism for Controlling Atmospheric Carbon Dioxide Concentrations – Final Project Report

    Energy Technology Data Exchange (ETDEWEB)

    Brady D. Lee; William A. Apel; Michelle R. Walton

    2006-03-01

    Species of cyanobacteria in the genera Synechococcus and Synechocystis are known to be the catalysts of a phenomenon called "whitings", which is the formation and precipitation of fine-grained CaCO3 particles. Whitings occur when the cyanobacteria fix atmospheric CO2 through the formation of CaCO3 on their cell surfaces which leads to precipitation to the ocean floor and subsequent entombment in mud. Whitings represent one potential mechanism for CO2 sequestration. Research was performed to determine the ability of various strains of Synechocystis and Synechococcus to calcify when grown in microcosms amended with 2.5 mM HCO3- and 3.4 mM Ca2+. Results indicated that while all strains tested have the ability to calcify, only two, Synechococcus species, strains PCC 8806 and PCC 8807, were able to calcify to the extent that CaCO3 was precipitated. Enumeration of the cyanobacterial cultures during testing indicated that cell density did not appear to have an effect on calcification. Factors that had the greatest effect on calcification were CO2 removal and subsequent generation of alkaline pH. As CO2 was removed, growth medium pH increased and soluble Ca2+ was removed from solution. The largest increases in growth medium pH occurred when CO2 levels dropped below 400 ppmv. Precipitation of CaCO3 catalyzed by the growth and physiology of cyanobacteria in the Genus Synechococcus represents a potential mechanism for sequestration of atmospheric CO2 produced during the burning of coal for power generation. Synechococcus sp. strain PCC 8806 and Synechococcus sp. strain PCC 8807 were tested in microcosm experiments for their ability to calcify when exposed to a fixed calcium concentration of 3.4 mM and dissolved inorganic carbon concentrations of 0.5, 1.25 and 2.5 mM. Synechococcus sp. strain PCC 8806 removed calcium continuously over the duration of the experiment producing approximately 18.6 mg of solid-phase calcium. Calcium removal occurred over a two-day time period when

  9. Nanoscale copper in the soil–plant system – toxicity and underlying potential mechanisms

    International Nuclear Information System (INIS)

    Anjum, Naser A.; Adam, Vojtech; Kizek, Rene; Duarte, Armando C.; Pereira, Eduarda; Iqbal, Muhammad; Lukatkin, Alexander S.; Ahmad, Iqbal

    2015-01-01

    Nanoscale copper particles (nano-Cu) are used in many antimicrobial formulations and products for their antimicrobial activity. They may enter deliberately and/or accidentally into terrestrial environments including soils. Being the major ‘eco-receptors’ of nanoscale particles in the terrestrial ecosystem, soil–microbiota and plants (the soil–plant system) have been used as a model to dissect the potential impact of these particles on the environmental and human health. In the soil–plant system, the plant can be an indirect non-target organism of the soil-associated nano-Cu that may in turn affect plant-based products and their consumers. By all accounts, information pertaining to nano-Cu toxicity and the underlying potential mechanisms in the soil–plant system remains scanty, deficient and little discussed. Therefore, based on some recent reports from (bio)chemical, molecular and genetic studies of nano-Cu versus soil–plant system, this article: (i) overviews the status, chemistry and toxicity of nano-Cu in soil and plants, (ii) discusses critically the poorly understood potential mechanisms of nano-Cu toxicity and tolerance both in soil–microbiota and plants, and (iii) proposes future research directions. It appears from studies hitherto made that the uncontrolled generation and inefficient metabolism of reactive oxygen species through different reactions are the major factors underpinning the overall nano-Cu consequences in both the systems. However, it is not clear whether the nano-Cu or the ion released from it is the cause of the toxicity. We advocate to intensify the multi-approach studies focused at a complete characterization of the nano-Cu, its toxicity (during life cycles of the least-explored soil–microbiota and plants), and behavior in an environmentally relevant terrestrial exposure setting. Such studies may help to obtain a deeper insight into nano-Cu actions and address adequately the nano-Cu-associated safety concerns in the

  10. Criteria, potentials and costs of forestry activities to sequester carbon within the framework of the clean development mechanism

    NARCIS (Netherlands)

    Waterloo, M.J.; Spiertz, P.H.; Diemont, W.H.; Emmer, I.; Aalders, E.; Wichink Kruit, R.J.; Kabat, P.

    2003-01-01

    Forest activities in developing countries can be used to sequester carbon for gaining emission reductions within the Clean Development Mechanism of the Kyoto Protocol. This study has assessed the potentials and costs for carbon sequestration through afforestation, reforestation and deforestation

  11. Standard metabolic rate predicts growth trajectory of juvenile Chinese crucian carp (Carassius auratus under changing food availability

    Directory of Open Access Journals (Sweden)

    Ling-Qing Zeng

    2017-09-01

    Full Text Available Phenotypic traits vary greatly within populations and can have a significant influence on aspects of performance. The present study aimed to investigate the effects of individual variation in standard metabolic rate (SMR on growth rate and tolerance to food deprivation in juvenile Chinese crucian carp (Carassius auratus under varying levels of food availability. To address this issue, 19 high and 16 low SMR individuals were randomly assigned to a satiation diet for 3 weeks, whereas another 20 high and 16 low SMR individuals were assigned to a restricted diet (approximately 50% of satiation for the same period. Then, all fish were completely food-deprived for another 3 weeks. High SMR individuals showed a higher growth rate when fed to satiation, but this advantage of SMR did not exist in food-restricted fish. This result was related to improved feeding efficiency with decreased food intake in low SMR individuals, due to their low food processing capacity and maintenance costs. High SMR individuals experienced more mass loss during food deprivation as compared to low SMR individuals. Our results here illustrate context-dependent costs and benefits of intraspecific variation in SMR whereby high SMR individuals show increased growth performance under high food availability but had a cost under stressful environments (i.e. food shortage.

  12. Standard metabolic rate predicts growth trajectory of juvenile Chinese crucian carp (Carassius auratus) under changing food availability.

    Science.gov (United States)

    Zeng, Ling-Qing; Zhang, An-Jie; Killen, Shaun S; Cao, Zhen-Dong; Wang, Yu-Xiang; Fu, Shi-Jian

    2017-09-15

    Phenotypic traits vary greatly within populations and can have a significant influence on aspects of performance. The present study aimed to investigate the effects of individual variation in standard metabolic rate (SMR) on growth rate and tolerance to food deprivation in juvenile Chinese crucian carp ( Carassius auratus ) under varying levels of food availability. To address this issue, 19 high and 16 low SMR individuals were randomly assigned to a satiation diet for 3 weeks, whereas another 20 high and 16 low SMR individuals were assigned to a restricted diet (approximately 50% of satiation) for the same period. Then, all fish were completely food-deprived for another 3 weeks. High SMR individuals showed a higher growth rate when fed to satiation, but this advantage of SMR did not exist in food-restricted fish. This result was related to improved feeding efficiency with decreased food intake in low SMR individuals, due to their low food processing capacity and maintenance costs. High SMR individuals experienced more mass loss during food deprivation as compared to low SMR individuals. Our results here illustrate context-dependent costs and benefits of intraspecific variation in SMR whereby high SMR individuals show increased growth performance under high food availability but had a cost under stressful environments (i.e. food shortage). © 2017. Published by The Company of Biologists Ltd.

  13. Morphological, histological and molecular characterization of Myxobolus kingchowensis and Thelohanellus cf. sinensis infecting gibel carp Carassius auratus gibelio (Bloch, 1782).

    Science.gov (United States)

    Zhang, Bo; Zhai, Yanhua; Gu, Zemao; Liu, Yang

    2018-06-26

    A Myxobolus species and a Thelohanellus species infecting Carassius auratus gibelio (Bloch, 1782) were redescribed by their morphological, histological and molecular characterization. In the present study, the Myxobolus species infecting the muscle was identified as Myxobolus kingchowensis Chen et Ma, 1998 by the morphological and molecular data. Histologically, mature spores of M. kingchowensis were observed in the intercellular and connective tissue of muscle, though the plasmodia were not found. In addition, scattered spores also occurred in the intercellular of haematopoietic cells, intraepithelial of the renal tubules and interior of the melano-macrophage centres. Phylogenetic analysis showed that M. kingchowensis clustered in the clade of muscle-infecting Myxobolus species, further supporting muscle as the infection site of M. kingchowensis. The present Thelohanellus species infecting the gills was identified conspecific as Thelohanellus sinensis reported in Sun (2006) (mark it as T. sinensis-Sun)based on spore morphology, biological traits (host specificity and organ specificity), and molecular data. However, compared with the original description of T. sinensis Chen et Hsieh, 1960, the present Thelohanellus species and T. sinensis-Sun both infecting the gills of gibel carp are distinguishable from the original description in the host and infection site, which made the validity of T. sinensis-Sun dubious. Due to the absence of molecular data in the original description of T. sinensis, we suggest marking the present species and T. sinensis-Sun as T. cf. sinensis to avoid the confusion until T. sinensis is obtained from the type host and type infection site.

  14. Burst-swimming performance predicts the outcome of cannibalistic interactions in green poison frog larvae (Dendrobates auratus).

    Science.gov (United States)

    Wilcox, Sean C; Lappin, A Kristopher

    2013-11-01

    Whole-animal performance (e.g., swimming speed, bite force) functions as a fundamental link between organism and environment and, as such, performance characteristics are important in determining the outcomes of agonistic interactions, both interspecific and intraspecific. Cannibalism is an intraspecific agonistic interaction for which winners may be expected to exhibit superior performance in characteristics relevant to cannibalistic behavior. The larvae of the Green Poison Frog (Dendrobates auratus) exhibit cannibalistic behavior in which "fast-starts" (i.e., high velocity and acceleration from a resting position) are used in attempts to bite and avoid being bitten by conspecifics. We tested the hypothesis that superior fast-start swimming performance is positively associated with winning cannibalistic interactions between similarly sized individuals. Fast-starts by larvae were imaged with a high-speed camera, and pairs of size-matched individuals then underwent interaction trials to determine whether swimming performance is associated with winning a cannibalistic interaction. Linear acceleration of the snout tip, approximating the position of the mouthparts used to attack an opponent, was significantly greater in winners than losers. At the estimated center of mass, generally representing a target for an attacking opponent, linear velocity and acceleration were significantly greater in winners than losers. Understanding the role of performance in intraspecific interactions can help elucidate how they contribute to population dynamics, and thus how such interactions ultimately drive morphological and behavioral evolution. © 2013 Wiley Periodicals, Inc.

  15. Ectocommensal and ectoparasites in goldfish Carassius auratus (Linnaeus, 1758 in farmed in the State of São Paulo

    Directory of Open Access Journals (Sweden)

    Carla Renata Serantoni Moyses

    Full Text Available Concomitant infections by several parasitic genera are rare, very debilitating and often lethal to fish reared under commercial breeding conditions. Were describe a multiple and concurrent parasite infestation in cultured goldfish Carassius auratus with skin damage (nodules and/or ulceration. Fish with skin lesions underwent necropsy, and the skin and gills were scraped and examined. Histopathological examination with Hematoxylin-Eosin and Giemsa stain, and an ultrastructure study using transmission and scanning electron microscopy were conducted. In the skin, we identified multiple-parasite infestations by Gyrodactylidae, Epistylis sp., Trichodina sp., Ichthyophthirius multifiliis, Tetrahymena sp. and Ichthyobodo necator,associated with epithelial cell hyperplasia and epidermal sloughing. Although no gross lesions were observed, were identified a large number of parasites in the gills (Epistylis sp., Piscinoodinium sp., Ichthyophthirius multifiliis, Trichodina sp., Apiosoma sp., Hexamitasp. and cysts of a trematode digenean. The observed trematodes were not identified. The associated microscopic lesions were epithelial hypertrophic and hyperplasic and exhibited fusion of secondary lamellae and epithelial cell detachment. This is the first description of a protozoan Vorticella sp. parasitizing goldfish in Brazil. Multiple ectoparasitism by protozoa and Platyhelminthes, with or without apparent tissue damage, can be fatal for goldfish raised on farms with poor management.

  16. Evaluation of the Leishmanicidal Activity of Rutaceae and Lauraceae Ethanol Extracts on Golden Syrian Hamster (Mesocricetus auratus) Peritoneal Macrophages.

    Science.gov (United States)

    Chávez Enciso, N A; Coy-Barrera, E D; Patiño, O J; Cuca, L E; Delgado, Gabriela

    2014-05-01

    Traditional medicine has provided a number of therapeutic solutions for the control of infectious agents, cancers, and other diseases. After screening a wide variety of Colombian plant extracts, we have identified promising antileishmanial activity in ethanol extracts from Ocotea macrophylla (Lauraceae) and Zanthoxyllum monophyllum (Rutaceae). In this study, we evaluated the in vitro activity of two ethanol extracts, one from Ocotea macrophylla and the other from Zanthoxyllum monophyllum and one alkaloid fraction of ethanol extract of Zanthoxyllum monophyllum, on peritoneal macrophages isolated from golden Syrian hamsters (Mesocricetus auratus) infected with Leishmania panamensis and Leishmania major promastigotes. All of the extracts studied displayed promising (≥2) selectivity indices (S/I), the most significant of which were for ethanol extract of Zanthoxyllum monophyllum against Leishmania panamensis (S/I=12) and alkaloid fraction of ethanol extract of Zanthoxyllum monophyllum against Leishmania major (S/I=11). These results support the use of ethanol extracts and alkaloid fractions isolated from Ocotea macrophylla and Zanthoxyllum monophyllum, respectively; as therapeutic options for cutaneous leishmaniasis.

  17. Glucose-6-phosphate isomerase is an endogenous inhibitor to myofibril-bound serine proteinase of crucian carp (Carassius auratus).

    Science.gov (United States)

    Sun, Le-Chang; Zhou, Li-Gen; Du, Cui-Hong; Cai, Qiu-Feng; Hara, Kenji; Su, Wen-Jin; Cao, Min-Jie

    2009-06-24

    Glucose-6-phosphate isomerase (GPI) was purified to homogeneity from the skeletal muscle of crucian carp ( Carassius auratus ) by ammonium sulfate fractionation, column chromatographies of Q-Sepharose, SP-Sepharose, and Superdex 200 with a yield of 8.0%, and purification folds of 468. The molecular mass of GPI was 120 kDa as estimated by gel filtration, while on sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE), two subunits (55 and 65 kDa) were identified, suggesting that it is a heterodimer. Interestingly, GPI revealed specific inhibitory activity toward a myofibril-bound serine proteinase (MBSP) from crucian carp, while no inhibitory activity was identified toward other serine proteinases, such as white croaker MBSP and crucian carp trypsin. Kinetic analysis showed that GPI is a competitive inhibitor toward MBSP, and the K(i) was 0.32 microM. Our present results indicated that the multifunctional protein GPI is an endogenous inhibitor to MBSP and may play a significant role in the regulation of muscular protein metabolism in vivo.

  18. The stimulatory effect of LED light spectra on genes related to photoreceptors and skin pigmentation in goldfish (Carassius auratus).

    Science.gov (United States)

    Shin, Hyun Suk; Choi, Cheol Young

    2014-08-01

    This study aimed to assess differences in genes related to skin color of goldfish (Carassius auratus) exposed to light-emitting diodes (LEDs): red, green, and purple. We investigated differences in the expression of mammalian-like melanopsin (Opn4m), rhodopsin (RH), melanin-concentrating hormone (MCH), melanin-concentrating hormone receptor (MCH-R), and proopiomelanocortin (POMC) in goldfish exposed to different LED light spectra. Opn4m, RH, MCH, and MCH-R mRNA levels were significantly higher in the green and purple LED groups than in the white fluorescent bulb (control) and red LED groups. Furthermore, skin cells were isolated to measure the MCH-R mRNA expression levels. The results show that the mRNA expression levels were significantly higher in the green and purple LED groups than in the control and red LED groups. In addition, body weights in the green and purple LED groups were significantly higher than those in the control and red LED groups. However, POMC mRNA expression levels in the green and purple LED groups were significantly lower than those in the control and red LED groups. These results suggest that specific wavelengths regulate fish skin color through neuropeptide hormones and photoreceptors, and POMC, which is related to stress hormones and melatonin, is associated with stress levels as well as skin color.

  19. Effects of nutritional history on stress response in gibel carp (Carassius auratus gibelio) and largemouth bass (Micropterus salmoides).

    Science.gov (United States)

    Jiang, Danli; Wu, Yubo; Huang, Di; Ren, Xing; Wang, Yan

    2017-08-01

    The stress response of omnivorous gibel carp (Carassius auratus gibelio) and carnivorous largemouth bass (Micropterus salmoides) with different nutritional history were evaluated. A 2×2 layout, including two fish species (gibel carp or largemouth bass) and two nutritional history (fasted or fed to satiation for four weeks), was used. After feeding or fasting, the fishes were subjected to an acute handling. Fasting resulted in decrease of plasma glucose level and liver glycogen content of gibel carp and largemouth bass. After handling stress, plasma levels of cortisol, glucose and lactate of gibel carp and largemouth bass increased, regardless the fasted fish or fed fish. During the period from 0h to 24h post-stress, the fasted gibel carp exhibited lower plasma cortisol and glucose levels, brain and liver glycogen contents, and liver phosphoenolpyruvate carboxykinase (PEPCK) activity compared with the fed counterpart. The plasma glucose level, brain glucose level, brain and liver glycogen contents were lower, while the liver PEPCK and hexokinase (HK) activities were higher, in the faster largemouth bass than the fed counterpart. This study indicates that nutritional history can influence stress response of gibel carp and largemouth bass, and the stress response is less severe in the fasted fish relative to the fed counterpart. This study also reveals that gibel carp and largemouth bass may have different strategies in response to fasting and acute handling stress. Copyright © 2017 Elsevier Inc. All rights reserved.

  20. Mechanical, dynamic-mechanical and thermal properties of soy protein-based thermoplastics with potential biomedical applications

    NARCIS (Netherlands)

    Vaz, C.A.; Mano, J.F.; Fossen, M.; Tuil, van R.F.; Graaf, de L.A.; Reis, R.L.; Cunha, A.A.

    2002-01-01

    In this study the tensile and the dynamic-mechanical behavior of injection-molded samples of various soy protein thermoplastic compounds were evaluated as a function of the amount of glycerol, type and amount of ceramic reinforcement, and eventual incorporation of coupling agents. The incorporation

  1. Quantum Mechanics/Molecular Mechanics Method Combined with Hybrid All-Atom and Coarse-Grained Model: Theory and Application on Redox Potential Calculations.

    Science.gov (United States)

    Shen, Lin; Yang, Weitao

    2016-04-12

    We developed a new multiresolution method that spans three levels of resolution with quantum mechanical, atomistic molecular mechanical, and coarse-grained models. The resolution-adapted all-atom and coarse-grained water model, in which an all-atom structural description of the entire system is maintained during the simulations, is combined with the ab initio quantum mechanics and molecular mechanics method. We apply this model to calculate the redox potentials of the aqueous ruthenium and iron complexes by using the fractional number of electrons approach and thermodynamic integration simulations. The redox potentials are recovered in excellent accordance with the experimental data. The speed-up of the hybrid all-atom and coarse-grained water model renders it computationally more attractive. The accuracy depends on the hybrid all-atom and coarse-grained water model used in the combined quantum mechanical and molecular mechanical method. We have used another multiresolution model, in which an atomic-level layer of water molecules around redox center is solvated in supramolecular coarse-grained waters for the redox potential calculations. Compared with the experimental data, this alternative multilayer model leads to less accurate results when used with the coarse-grained polarizable MARTINI water or big multipole water model for the coarse-grained layer.

  2. Potential mechanisms supporting the value of motor cortex stimulation to treat chronic pain syndromes

    Directory of Open Access Journals (Sweden)

    Marcos Fabio DosSantos

    2016-02-01

    Full Text Available Throughout the first years of the twenty-first century, neurotechnologies such as motor cortex stimulation (MCS, transcranial magnetic stimulation (TMS and transcranial direct current stimulation (tDCS have attracted scientific attention and been considered as potential tools to centrally modulate chronic pain, especially for those conditions more difficult to manage and refractory to all types of available pharmacological therapies. Interestingly, although the role of the motor cortex in pain has not been fully clarified, it is one of the cortical areas most commonly targeted by invasive and non-invasive neuromodulation technologies. Recent studies have provided significant advances concerning the establishment of the clinical effectiveness of primary motor cortex stimulation to treat different chronic pain syndromes. Concurrently, the neuromechanisms related to each method of primary motor cortex (M1 modulation have been unveiled. In this respect, the most consistent scientific evidence originates from MCS studies, which indicate the activation of top-down controls driven by M1 stimulation. This concept has also been applied to explain M1-TMS mechanisms. Nevertheless, activation of remote areas in the brain, including cortical and subcortical structures, has been reported with both invasive and non-invasive methods and the participation of major neurotransmitters (e.g. glutamate, GABA and serotonin as well as the release of endogenous opioids has been demonstrated. In this critical review, the putative mechanisms underlying the use of motor cortex stimulation to provide relief from chronic migraine and other types of chronic pain are discussed. Emphasis is placed on the most recent scientific evidence obtained from chronic pain research studies involving MCS and non-invasive neuromodulation methods (e.g. tDCS and TMS, which are analyzed comparatively.

  3. Potential Mechanisms Supporting the Value of Motor Cortex Stimulation to Treat Chronic Pain Syndromes.

    Science.gov (United States)

    DosSantos, Marcos F; Ferreira, Natália; Toback, Rebecca L; Carvalho, Antônio C; DaSilva, Alexandre F

    2016-01-01

    Throughout the first years of the twenty-first century, neurotechnologies such as motor cortex stimulation (MCS), transcranial magnetic stimulation (TMS), and transcranial direct current stimulation (tDCS) have attracted scientific attention and been considered as potential tools to centrally modulate chronic pain, especially for those conditions more difficult to manage and refractory to all types of available pharmacological therapies. Interestingly, although the role of the motor cortex in pain has not been fully clarified, it is one of the cortical areas most commonly targeted by invasive and non-invasive neuromodulation technologies. Recent studies have provided significant advances concerning the establishment of the clinical effectiveness of primary MCS to treat different chronic pain syndromes. Concurrently, the neuromechanisms related to each method of primary motor cortex (M1) modulation have been unveiled. In this respect, the most consistent scientific evidence originates from MCS studies, which indicate the activation of top-down controls driven by M1 stimulation. This concept has also been applied to explain M1-TMS mechanisms. Nevertheless, activation of remote areas in the brain, including cortical and subcortical structures, has been reported with both invasive and non-invasive methods and the participation of major neurotransmitters (e.g., glutamate, GABA, and serotonin) as well as the release of endogenous opioids has been demonstrated. In this critical review, the putative mechanisms underlying the use of MCS to provide relief from chronic migraine and other types of chronic pain are discussed. Emphasis is placed on the most recent scientific evidence obtained from chronic pain research studies involving MCS and non-invasive neuromodulation methods (e.g., tDCS and TMS), which are analyzed comparatively.

  4. Electrophysiological potentials reveal cortical mechanisms for mental imagery, mental simulation, and grounded (embodied cognition

    Directory of Open Access Journals (Sweden)

    Haline E. Schendan

    2012-09-01

    Full Text Available Grounded cognition theory proposes that cognition, including meaning, is grounded in sensorimotor processing. The mechanism for grounding cognition is mental simulation, which is a type of mental imagery that re-enacts modal processing. To reveal top-down, cortical mechanisms for mental simulation of shape, event-related potentials were recorded to face and object pictures preceded by mental imagery of a picture. Mental imagery of the identical face or object (congruous condition facilitated not only categorical perception (VPP/N170 but also later visual knowledge (N3[00] complex and linguistic knowledge (N400 for faces more than objects, and strategic semantic analysis (late positive complex between 200 and 700 ms. The later effects resembled semantic congruity effects with pictures. Mental imagery also facilitated category decisions, as a P3(00 peaked earlier for congruous than incongruous (other category pictures, resembling the case when identical pictures repeat immediately. Thus mental imagery mimics semantic congruity and immediate repetition priming processes with pictures. Perception control results showed the opposite for faces and were in the same direction for objects: Perceptual repetition adapts (and so impairs processing of perceived faces from categorical perception onwards, but primes processing of objects during categorical perception, visual knowledge processes, and strategic semantic analysis. For both imagery and perception, differences between faces and objects support domain-specificity and indicate that cognition is grounded in modal processing. Altogether, this direct neural evidence reveals that top-down processes of mental imagery sustain an imagistic representation that mimics perception well enough to prime subsequent perception and cognition. This also suggests that automatic mental simulation of the visual shape of faces and objects operates between 200 and 400 ms, and strategic mental simulation operates between

  5. Cow's Milk and Immune Function in the Respiratory Tract: Potential Mechanisms.

    Science.gov (United States)

    Perdijk, Olaf; van Splunter, Marloes; Savelkoul, Huub F J; Brugman, Sylvia; van Neerven, R J Joost

    2018-01-01

    milk may influence homing of lymphocytes to the upper respiratory tract. This review focuses on potential mechanisms via which cow's milk or its components can influence immune function in the intestine and the upper respiratory tract. Unraveling these complex mechanisms may contribute to the development of novel dietary approaches in allergy and asthma prevention.

  6. Cow’s Milk and Immune Function in the Respiratory Tract: Potential Mechanisms

    Directory of Open Access Journals (Sweden)

    Olaf Perdijk

    2018-02-01

    in milk, we speculate that raw milk may influence homing of lymphocytes to the upper respiratory tract. This review focuses on potential mechanisms via which cow’s milk or its components can influence immune function in the intestine and the upper respiratory tract. Unraveling these complex mechanisms may contribute to the development of novel dietary approaches in allergy and asthma prevention.

  7. Short-chain carboxylic acids, a new class of teratogens: studies of potential biochemical mechanisms

    Energy Technology Data Exchange (ETDEWEB)

    Coakley, M.E.; Rawlings, S.J.; Brown, N.A.

    1986-12-01

    Certain short-chain carboxylic acids (SCCA) appear to share a common teratogenic potential, although the structural requirements for activity remain obscure. By using a whole rat embryo culture model system, several biochemical processes have been examined, either as potential initial sites of teratogenic action or as early steps in the pathway to malformation. Valproate, methoxyacetate, and butyrate were the prototype SCCA examined. Measurement of (/sup 14/C)glucose utilization and lactate production confirmed that energy production by the early organogenesis embryo is predominantly from glycolysis. While the positive control agent, iodoacetate, caused a significant inhibition of lactate production, none of the SCCA affected this process or glucose utilization at teratogenic concentrations. Pinocytosis by the visceral yolk sac (VYS) was measured by the uptake of (/sup 125/I)polyvinylpyrrolidone. This process ultimately supplies the embryo with amino-acids and is essential for normal development. SCCA induce morphological abnormalities of the VYS in embryo culture. Pinocytosis was slightly reduced by valproate, but not the other SCCA. However, comparison with the action of an antiserum, for which inhibition of pinocytosis is the initial teratogenic insult, suggests that this is not the mechanism for valproate. Incorporation of (/sup 3/H)thymidine into embryo or yolk sac was not affected after 3 hr of SCCA exposure, but there was a marked effect of the positive control, hydroxyurea. This suggests that DNA synthesis is not directly influenced by SCCA. It can be concluded that SCCA do not exert their teratogenic effects by actions on glycolysis; maintenance of cellular acetyl CoA; pinocytosis or DNA synthesis. These observations contrast with preliminary results which suggest significant effects of SCCA on embryonic and yolk sac lipid metabolic pathways.

  8. Phenoxybenzamine in Complex Regional Pain Syndrome: Potential Role and Novel Mechanisms

    Science.gov (United States)

    Inchiosa, Mario A.

    2013-01-01

    There is a relatively long history of the use of the α-adrenergic antagonist, phenoxybenzamine, for the treatment of complex regional pain syndrome (CRPS). One form of this syndrome, CRPS I, was originally termed reflex sympathetic dystrophy (RSD) because of an apparent dysregulation of the sympathetic nervous system in the region of an extremity that had been subjected to an injury or surgical procedure. The syndrome develops in the absence of any apparent continuation of the inciting trauma. Hallmarks of the condition are allodynia (pain perceived from a nonpainful stimulus) and hyperalgesia (exaggerated pain response to a painful stimulus). In addition to severe, unremitting burning pain, the affected limb is typically warm and edematous in the early weeks after trauma but then progresses to a primarily cold, dry limb in later weeks and months. The later stages are frequently characterized by changes to skin texture and nail deformities, hypertrichosis, muscle atrophy, and bone demineralization. Earlier treatments of CRPS syndromes were primarily focused on blocking sympathetic outflow to an affected extremity. The use of an α-adrenergic antagonist such as phenoxybenzamine followed from this perspective. However, the current consensus on the etiology of CRPS favors an interpretation of the symptomatology as an evidence of decreased sympathetic activity to the injured limb and a resulting upregulation of adrenergic sensitivity. The clinical use of phenoxybenzamine for the treatment of CRPS is reviewed, and mechanisms of action that include potential immunomodulatory/anti-inflammatory effects are presented. Also, a recent study identified phenoxybenzamine as a potential intervention for pain mediation from its effects on gene expression in human cell lines; on this basis, it was tested and found to be capable of reducing pain behavior in a classical animal model of chronic pain. PMID:24454356

  9. Phenoxybenzamine in Complex Regional Pain Syndrome: Potential Role and Novel Mechanisms

    Directory of Open Access Journals (Sweden)

    Mario A. Inchiosa

    2013-01-01

    Full Text Available There is a relatively long history of the use of the α-adrenergic antagonist, phenoxybenzamine, for the treatment of complex regional pain syndrome (CRPS. One form of this syndrome, CRPS I, was originally termed reflex sympathetic dystrophy (RSD because of an apparent dysregulation of the sympathetic nervous system in the region of an extremity that had been subjected to an injury or surgical procedure. The syndrome develops in the absence of any apparent continuation of the inciting trauma. Hallmarks of the condition are allodynia (pain perceived from a nonpainful stimulus and hyperalgesia (exaggerated pain response to a painful stimulus. In addition to severe, unremitting burning pain, the affected limb is typically warm and edematous in the early weeks after trauma but then progresses to a primarily cold, dry limb in later weeks and months. The later stages are frequently characterized by changes to skin texture and nail deformities, hypertrichosis, muscle atrophy, and bone demineralization. Earlier treatments of CRPS syndromes were primarily focused on blocking sympathetic outflow to an affected extremity. The use of an α-adrenergic antagonist such as phenoxybenzamine followed from this perspective. However, the current consensus on the etiology of CRPS favors an interpretation of the symptomatology as an evidence of decreased sympathetic activity to the injured limb and a resulting upregulation of adrenergic sensitivity. The clinical use of phenoxybenzamine for the treatment of CRPS is reviewed, and mechanisms of action that include potential immunomodulatory/anti-inflammatory effects are presented. Also, a recent study identified phenoxybenzamine as a potential intervention for pain mediation from its effects on gene expression in human cell lines; on this basis, it was tested and found to be capable of reducing pain behavior in a classical animal model of chronic pain.

  10. Properties and ionic mechanisms of action potential adaptation, restitution, and accommodation in canine epicardium

    Science.gov (United States)

    Decker, Keith F.; Heijman, Jordi; Silva, Jonathan R.; Hund, Thomas J.; Rudy, Yoram

    2009-01-01

    Computational models of cardiac myocytes are important tools for understanding ionic mechanisms of arrhythmia. This work presents a new model of the canine epicardial myocyte that reproduces a wide range of experimentally observed rate-dependent behaviors in cardiac cell and tissue, including action potential (AP) duration (APD) adaptation, restitution, and accommodation. Model behavior depends on updated formulations for the 4-aminopyridine-sensitive transient outward current (Ito1), the slow component of the delayed rectifier K+ current (IKs), the L-type Ca2+ channel current (ICa,L), and the Na+-K+ pump current (INaK) fit to data from canine ventricular myocytes. We found that Ito1 plays a limited role in potentiating peak ICa,L and sarcoplasmic reticulum Ca2+ release for propagated APs but modulates the time course of APD restitution. IKs plays an important role in APD shortening at short diastolic intervals, despite a limited role in AP repolarization at longer cycle lengths. In addition, we found that ICa,L plays a critical role in APD accommodation and rate dependence of APD restitution. Ca2+ entry via ICa,L at fast rate drives increased Na+-Ca2+ exchanger Ca2+ extrusion and Na+ entry, which in turn increases Na+ extrusion via outward INaK. APD accommodation results from this increased outward INaK. Our simulation results provide valuable insight into the mechanistic basis of rate-dependent phenomena important for determining the heart's response to rapid and irregular pacing rates (e.g., arrhythmia). Accurate simulation of rate-dependent phenomena and increased understanding of their mechanistic basis will lead to more realistic multicellular simulations of arrhythmia and identification of molecular therapeutic targets. PMID:19168720

  11. Initial Response by a Native Beetle, Chrysochus auratus (Coleoptera: Chrysomelidae), to a Novel Introduced Host-Plant, Vincetoxicum rossicum (Gentianales: Apocynaceae).

    Science.gov (United States)

    deJonge, R B; Bourchier, R S; Smith, S M

    2017-06-01

    Native insects can form novel associations with introduced invasive plants and use them as a food source. The recent introduction into eastern North America of a nonnative European vine, Vincetoxicum rossicum (Kleopow) Barbar., allows us to examine the initial response of a native chrysomelid beetle, Chrysochus auratus F., that feeds on native plants in the same family as V. rossicum (Apocynaceae). We tested C. auratus on V. rossicum and closely related or co-occurring native plants (Apocynum spp., Asclepias spp., and Solidago canadensis L.) using all life stages of the beetle in lab, garden, and field experiments. Experiments measured feeding (presence or absence and amount), survival, oviposition, and whether previous exposure to V. rossicum in the lab or field affected adult beetle feeding. Beetles fed significantly less on V. rossicum than on native Apocynum hosts. Adult beetles engaged in exploratory feeding on leaves of V. rossicum and survived up to 10 d. Females oviposited on V. rossicum, eggs hatched, and larvae fed initially on the roots; however, no larvae survived beyond second instar. Beetles collected from Apocynum cannabinum L. field sites intermixed with V. rossicum were less likely to feed on this novel nonnative host than those collected from colonies further from and less likely to be exposed to V. rossicum (>5 km). Our experimental work indicates that V. rossicum may act as an oviposition sink for C. auratus and that this native beetle has not adapted to survive on this recently introduced novel host plant. © The Authors 2017. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  12. Reproductive biology of Catfish Chrysichthys auratus, Geoffroy Saint-Hilaire, 1809, (Family: Bagridae from Damietta branch of the River Nile, Egypt

    Directory of Open Access Journals (Sweden)

    Evelyn Ragheb

    2016-09-01

    Full Text Available Reproductive biology of 803 specimens of Chrysichthys auratus from Damietta branch of the River Nile, Egypt was studied between January and December 2010. The overall sex ratio (M:F = 1:1.18 was significant at P < 0.05 and the ratio showed insignificant variation in summer and autumn. The length of the onset sexual maturity was 12.3 cm SL at age 1.34 years for males and 9.7 cm SL at age 0.56 years for females. C. auratus showed prolonged spawning season extending from October to June with a peak in March for both sexes and the fish restart their reproductive cycle in July. The maximum value for GSI and GI were shown in March for both sexes (GSI = 0.49% ± 0.30 and 11.17% ± 9.65 for males and females respectively and GI = 1.02% ± 0.64 for males and 22.85% ± 20.00 for females. The reproductive load was 0.464 and 0.366 for males and females respectively. The study of ova diameters showed protracted and indefinite spawning period with diameters ranging from 0.3 to 3.0 mm (mean value = 1.53 ± 0.45. The absolute fecundity ranged from 696 to 4687 eggs but the relative fecundity was from 70 to 247 eggs/unit fish length. The results showed that C. auratus has different life history strategies in Egyptian River Nile water than any other African Rivers.

  13. Mechanisms underlying the wound healing potential of propolis based on its in vitro antioxidant activity.

    Science.gov (United States)

    Cao, Xue-Ping; Chen, Yi-Fan; Zhang, Jiang-Lin; You, Meng-Meng; Wang, Kai; Hu, Fu-Liang

    2017-10-15

    Propolis is a resinous substance collected by honeybees, Apis mellifera, from various plant sources. Having various pharmacological and biological activities, it has been used in folk medicine and complementary therapies since ancient times. To evaluate the effects and underlying mechanism of the protective effects of the ethanol extract of Chinese propolis (EECP) on L929 cells injured by hydrogen peroxide (H 2 O 2 ). The wound healing activities of EECP in L929 cells with H 2 O 2 -induced damage were investigated. The main components of EECP were analyzed by RP-HPLC, and the free radical scavenging capacity and reducing power were also measured. The effects of EECP on the expression of antioxidant-related genes in fibroblast L929 cells were determined using qRT-PCR and western blotting. EECP had significant protective effects against cell death induced by H 2 O 2 and significantly inhibited the decline of collagen mRNA expression caused by H 2 O 2 in L929 cells. EECP induced the expression of antioxidant-related genes, such as HO-1, GCLM, and GCLC, which has great implications for the potential of propolis to alleviate oxidative stress in wound tissues. The protective effects of propolis have great implications for using propolis as a wound healing regent. Copyright © 2017 Elsevier GmbH. All rights reserved.

  14. Genetic programs of the developing tuberal hypothalamus and potential mechanisms of their disruption by environmental factors.

    Science.gov (United States)

    Nesan, Dinushan; Kurrasch, Deborah M

    2016-12-15

    The hypothalamus is a critical regulator of body homeostasis, influencing the autonomic nervous system and releasing trophic hormones to modulate the endocrine system. The developmental mechanisms that govern formation of the mature hypothalamus are becoming increasingly understood as research in this area grows, leading us to gain appreciation for how these developmental programs are susceptible to disruption by maternal exposure to endocrine disrupting chemicals or other environmental factors in utero. These vulnerabilities, combined with the prominent roles of the various hypothalamic nuclei in regulating appetite, reproductive behaviour, mood, and other physiologies, create a window whereby early developmental disruption can have potent long-term effects. Here we broadly outline our current understanding of hypothalamic development, with a particular focus on the tuberal hypothalamus, including what is know about nuclear coalescing and maturation. We finish by discussing how exposure to environmental or maternally-derived factors can perhaps disrupt these hypothalamic developmental programs, and potentially lead to neuroendocrine disease states. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

  15. Efficacy of Morin as a Potential Therapeutic Phytocomponent: Insights into the Mechanism of Action

    Directory of Open Access Journals (Sweden)

    Amarendranath Choudhury

    2017-11-01

    Full Text Available Morin (3,5,7,29,49-pentahydroxyflavone is a yellow colour natural bioflavonoid abundantly available in different species of Moraceae family. Besides this, Morin is also harvested from several other sources like tea, coffee, cereals, fruits and red wine. Anti-oxidant, anti-inflammatory, and antiproliferative potency of Morin is well established in both in vivo and in vitro experiments. Among all major sources of Morin, Almond (Prunus dulcis, Fig (Chlorophora tinctoria, and Indian guava (Psidium guajava contains high quantity of it. Easy availability, less side effects and robust functional properties have encouraged the use of these plants in the traditional herbal medicine. In last few decades, the studies on Morin have opened up a whole new era in the therapeutic medicine. Besides anti-oxidant, anti-inflammatory, and antiproliferative activity, Morin has also been reported as a potential neuroprotective agent against many neurological diseases including Alzheimer’s disease, Parkinson’s disease, and cerebral ischemia. According to published reports, the underlying neuroprotective mechanism of Morin is focused mainly on its capacity to inhibit oxidative stress in brain. However, recent data also supports its efficacy in neuroprotection by effectively interacting in the β‒amyloid pathways, inflammatory pathways, and apoptotic pathways. In the present review, we have accumulated all the protective contributions of Morin and intended to drag a mechanistic pathway containing the molecular events leading to the protection against various anomalies.

  16. Energy Drinks and Their Impact on the Cardiovascular System: Potential Mechanisms12

    Science.gov (United States)

    Grasser, Erik Konrad; Charrière, Nathalie; Loonam, Cathríona R; Dulloo, Abdul G; Montani, Jean-Pierre

    2016-01-01

    Globally, the popularity of energy drinks is steadily increasing. Scientific interest in their effects on cardiovascular and cerebrovascular systems in humans is also expanding and with it comes a growing number of case reports of adverse events associated with energy drinks. The vast majority of studies carried out in the general population report effects on blood pressure and heart rate. However, inconsistencies in the current literature render it difficult to draw firm conclusions with regard to the effects of energy drinks on cardiovascular and cerebrovascular variables. These inconsistencies are due, in part, to differences in methodologies, volume of drink ingested, and duration of postconsumption measurements, as well as subject variables during the test. Recent well-controlled, randomized crossover studies that used continuous beat-to-beat measurements provide evidence that cardiovascular responses to the ingestion of energy drinks are best explained by the actions of caffeine and sugar, with little influence from other ingredients. However, a role for other active constituents, such as taurine and glucuronolactone, cannot be ruled out. This article reviews the potentially adverse hemodynamic effects of energy drinks, particularly on blood pressure and heart rate, and discusses the mechanisms by which their active ingredients may interact to adversely affect the cardiovascular system. Research areas and gaps in the literature are discussed with particular reference to the use of energy drinks among high-risk individuals. PMID:27633110

  17. Potential Mechanisms for Racial and Ethnic Differences in Antimüllerian Hormone and Ovarian Reserve

    Directory of Open Access Journals (Sweden)

    Reshef Tal

    2013-01-01

    Full Text Available Accumulating evidence suggests that reproductive potential and function may be different across racial and ethnic groups. Racial differences have been demonstrated in pubertal timing, infertility, outcomes after assisted reproductive technology (ART treatment, and reproductive aging. Recently, racial differences have also been described in serum antimüllerian hormone (AMH, a sensitive biomarker of ovarian reserve, supporting the notion that ovarian reserve differs between racial/ethnic groups. The existence of such racial/ethnic differences in ovarian reserve, as reflected by AMH, may have important clinical implications for reproductive endocrinologists. However, the mechanisms which may underlie such racial differences in ovarian reserve are unclear. Various genetic factors and environmental factors such as obesity, smoking, and vitamin D deficiency which have been shown to correlate with serum AMH levels and also display significant racial/ethnic variations are discussed in this review. Improving our understanding of racial differences in ovarian reserve and their underlying causes may be essential for infertility treatment in minority women and lead to better reproductive planning, improved treatment outcomes, and timely interventions which may prolong reproductive lifespan in these women.

  18. Effects of shift work and intermittent noise exposure on hearing: mechanisms and prophylactic potential.

    Science.gov (United States)

    Borchgrevink, Hans M

    2009-01-01

    It is well established that intermittent noise exposure characteristically produces less hearing loss than equal energy/intensity continuous noise in animal models. Ongoing different shift work regimes open for direct studies on hearing effects of intermittent noise exposure in man without ethical concern. Amazingly, few such studies are reported. In one recent study in the present volume, noise-exposed employees working 12 hours a day for two consecutive days followed by two days off, the cycle then repeated, had significantly lower permanent hearing loss than employees working nine-hour shifts from 8 am to 5 pm Monday to Friday. This commentary refers to the few studies reported, gives a short overview of the mechanisms behind noise-induced hearing loss and the protective effect of intermittent exposure, and concludes that direct studies in man on the effects of different shift work regimes on occupational hearing loss under specified noise conditions represent a prophylactic potential that calls for increased research activity. Such studies might pave the way for direct use of more optimal intermittent noise exposure regimes in future design of the noise exposure workday/-week and make future hearing conservation programs more effective.

  19. Energy Drinks and Their Impact on the Cardiovascular System: Potential Mechanisms.

    Science.gov (United States)

    Grasser, Erik Konrad; Miles-Chan, Jennifer Lynn; Charrière, Nathalie; Loonam, Cathríona R; Dulloo, Abdul G; Montani, Jean-Pierre

    2016-09-01

    Globally, the popularity of energy drinks is steadily increasing. Scientific interest in their effects on cardiovascular and cerebrovascular systems in humans is also expanding and with it comes a growing number of case reports of adverse events associated with energy drinks. The vast majority of studies carried out in the general population report effects on blood pressure and heart rate. However, inconsistencies in the current literature render it difficult to draw firm conclusions with regard to the effects of energy drinks on cardiovascular and cerebrovascular variables. These inconsistencies are due, in part, to differences in methodologies, volume of drink ingested, and duration of postconsumption measurements, as well as subject variables during the test. Recent well-controlled, randomized crossover studies that used continuous beat-to-beat measurements provide evidence that cardiovascular responses to the ingestion of energy drinks are best explained by the actions of caffeine and sugar, with little influence from other ingredients. However, a role for other active constituents, such as taurine and glucuronolactone, cannot be ruled out. This article reviews the potentially adverse hemodynamic effects of energy drinks, particularly on blood pressure and heart rate, and discusses the mechanisms by which their active ingredients may interact to adversely affect the cardiovascular system. Research areas and gaps in the literature are discussed with particular reference to the use of energy drinks among high-risk individuals. © 2016 American Society for Nutrition.

  20. Natural product modulators of human sensations and mood: molecular mechanisms and therapeutic potential.

    Science.gov (United States)

    Pluskal, Tomáš; Weng, Jing-Ke

    2018-03-05

    Humans perceive physical information about the surrounding environment through their senses. This physical information is registered by a collection of highly evolved and finely tuned molecular sensory receptors. A multitude of bioactive, structurally diverse ligands have evolved in nature that bind these molecular receptors. The complex, dynamic interactions between the ligands and the receptors lead to changes in our sensory perception or mood. Here, we review our current knowledge of natural products and their derived analogues that interact specifically with human G protein-coupled receptors, ion channels, and nuclear hormone receptors to modulate the sensations of taste, smell, temperature, pain, and itch, as well as mood and its associated behaviour. We discuss the molecular and structural mechanisms underlying such interactions and highlight cases where subtle differences in natural product chemistry produce drastic changes in functional outcome. We also discuss cases where a single compound triggers complex sensory or behavioural changes in humans through multiple mechanistic targets. Finally, we comment on the therapeutic potential of the reviewed area of research and draw attention to recent technological developments in genomics, metabolomics, and metabolic engineering that allow us to tap the medicinal properties of natural product chemistry without taxing nature.

  1. Thymidylate limitation potentiates cephalosporin activity towards enterococci via an exopolysaccharide-based mechanism

    Science.gov (United States)

    Hoff, Jessica S.; Kristich, Christopher J.

    2016-01-01

    Multi-drug resistant enterococci are major causes of nosocomial infections. Prior therapy with cephalosporins increases the risk of developing an enterococcal infection due to the intrinsic resistance of enterococci to these antibiotics. While progress has been made towards understanding the genetic and biochemical mechanisms of cephalosporin resistance, available data indicate that as-yet-unidentified resistance factors must exist. Here we describe results of a screen to identify small molecules capable of sensitizing enterococci to broad-spectrum cephalosporins. We found that both Enterococcus faecalis and Enterococcus faecium were sensitized to broad and expanded-spectrum cephalosporins when thymidylate production was impaired, whether by direct inhibition of thymidylate synthase, or by limiting production of cofactors required for its activity. Cephalosporin potentiation is the result of altered exopolysaccharide production due to reduced dTDP-glucose synthesis. Hence, exopolysaccharide production is a previously undescribed contributor to the intrinsic cephalosporin resistance of enterococci and serves as new target for anti-enterococcal therapeutics. PMID:27008338

  2. [Effects of biochar on soil nutrients leaching and potential mechanisms: A review].

    Science.gov (United States)

    Liu, Yu-xue; Lyu, Hao-hao; Shi, Yan; Wang, Yao-feng; Zhong, Zhe-ke; Yang, Sheng-mao

    2015-01-01

    Controlling soil nutrient leaching in farmland ecosystems has been a hotspot in the research field of agricultural environment. Biochar has its unique physical and chemical properties, playing a significant role in enhancing soil carbon storage, improving soil quality and increasing crop yield. As a kind of new exogenous material, biochar has the potential in impacting soil nutrient cycling directly or indirectly, and has profound influences on soil nutrient leaching. This paper analyzed the intrinsic factors affecting how biochar affects soil nutrient leaching, such as the physical and chemical properties of biochar, and the interaction between biochar and soil organisms. Then the latest literatures regarding the external factors, including biochar application rates, soil types, depth of soil layer, fertilization conditions and temporal dynamics, through which biochar influences soil nutrient (especially nitrogen and phosphorus) leaching were reviewed. On that basis, four related action mechanisms were clarified, including direct adsorption of nutrients by biochar due to its micropore structure or surface charge, influencing nutrient leaching through increasing soil water- holding capacity, influencing nutrient cycling through the interaction with soil microbes, and preferential transport of absorbed nutrients by fine biochar particles. At last future research directions for better understanding the interactions between biochar and nutrient leaching in the soil were proposed.

  3. [Effect of ferulic acid on cholesterol efflux in macrophage foam cell formation and potential mechanism].

    Science.gov (United States)

    Chen, Fu-xin; Wang, Lian-kai

    2015-02-01

    The formation of macrophage-derived foam cells is a typical feature of atherosclerosis (AS). Reverse cholesterol efflux (RCT) is one of important factors for the formation of macrophage foam cells. In this study, macrophage form cells were induced by oxidized low density lipoprotein (ox-LDL) and then treated with different concentrations of ferulic acid, so as to observe the effect of ferulic acid on the intracellular lipid metabolism in the ox-LDL-induced macrophage foam cell formation, the cholesterol efflux and the mRNA expression and protein levels of ATP binding cassette transporter A1 (ABCA1) and ATP binding cassette transporter G1 (ABCG1) that mediate cholesterol efflux, and discuss the potential mechanism of ferulic acid in resisting AS. According to the findings, compared with the control group, the ox-LDL-treated group showed significant increase in intracellular lipid content, especially for the cholesterol content; whereas the intracellular lipid accumulation markedly decreased, after the treatment with ferulic acid. The data also demonstrated that the mRNA and protein expressions of ABCA1 and ABCG1 significantly increased after macrophage foam cells were treated with different concentrations of ferulic acid. In summary, ferulic acid may show the anti-atherosclerosis effect by increasing the surface ABCA1 and ABCG1 expressions of macrophage form cells and promoting cholesterol efflux.

  4. The pDynamo Program for Molecular Simulations using Hybrid Quantum Chemical and Molecular Mechanical Potentials.

    Science.gov (United States)

    Field, Martin J

    2008-07-01

    The pDynamo program has been developed for the simulation of molecular systems using hybrid quantum chemical (QC) and molecular mechanical (MM) potentials. pDynamo is written in a mixture of the computer languages Python and C and is a successor to the previous version of Dynamo, now denoted fDynamo, that was written in Fortran 90 (J. Comput. Chem. 2000, 21, 1088). The current version of Dynamo has a similar range of functionality to the older one but extends it in some significant ways, including the addition of a density functional theory QC capability. This paper gives a general description of pDynamo and outlines some of the advantages and disadvantages that have been encountered in switching computer languages. Some technical aspects of the implementation of pDynamo's algorithms are also discussed and illustrated with the results of example calculations. pDynamo is available on the Web at the address http://www.pdynamo.org and is released under the CeCILL license which is equivalent to the GNU general public license but conforms to the principles of French law.

  5. HLA Preferences for Conserved Epitopes: A Potential Mechanism for Hepatitis C Clearance

    Directory of Open Access Journals (Sweden)

    Xiangyu eRao

    2015-10-01

    Full Text Available Hepatitis C virus (HCV infections affect more than 170 million people worldwide. Most of these individuals are chronically infected, but some clear the infection rapidly. Host factors seem to play a key role in HCV clearance, among them the human leukocyte antigen (HLA class I molecules. Certain HLA molecules, e.g. B*27 and B*57, are associated with viral clearance. To identify potential mechanisms for these associations, we assess epitope distribution differences between HLA molecules using experimentally verified and in silico predicted HCV epitopes. Specifically, we show that the NS5B protein harbors the largest fraction of conserved regions among all HCV proteins, which could be good targets for cytotoxic T cell (CTL responses. We find that the protective HLA-B*27 molecule preferentially presents cytotoxic T cell (CTL epitopes from NS5B, and in general presents the most strongly conserved epitopes among the 23 HLA molecules analyzed. In contrast, HLA molecules known to be associated with HCV persistence do not have similar preferences, and appear to target the variable P7 protein. Overall, our analysis suggests that by targeting highly constrained - and thereby conserved - regions of HCV, the protective HLA molecule HLA-B*27 reduces the ability of HCV to escape the cytotoxic T cell response of the host. For visualizing the distribution of both experimentally verified and predicted epitopes across the HCV genome, we created the HCV epitope browser, which is available at theory.bio.uu.nl/ucqi/hcv.

  6. Recent evidence and potential mechanisms underlying weight gain and insulin resistance due to atypical antipsychotics

    Directory of Open Access Journals (Sweden)

    Ana Maria Volpato

    2013-09-01

    Full Text Available Objective: Atypical antipsychotics (AAPs promote obesity and insulin resistance. In this regard, the main objective of this study was to present potential mechanisms and evidence concerning side effects of atypical antipsychotics in humans and rodents. Method: A systematic review of the literature was performed using the MEDLINE database. We checked the references of selected articles, review articles, and books on the subject. Results: This review provides consistent results concerning the side effects of olanzapine (OL and clozapine (CLZ, whereas we found conflicting results related to other AAPs. Most studies involving humans describe the effects on body weight, adiposity, lipid profile, and blood glucose levels. However, it seems difficult to identify an animal model replicating the wide range of changes observed in humans. Animal lineage, route of administration, dose, and duration of treatment should be carefully chosen for the replication of the findings in humans. Conclusions: Patients undergoing treatment with AAPs are at higher risk of developing adverse metabolic changes. This increased risk must be taken into account when making decisions about treatment. The influence of AAPs on multiple systems is certainly the cause of such effects. Specifically, muscarinic and histaminergic pathways seem to play important roles.

  7. Gastrointestinal obstruction caused by solidification and coagulation of enteral nutrition: pathogenetic mechanisms and potential risk factors

    Directory of Open Access Journals (Sweden)

    Leonello G

    2018-04-01

    Full Text Available Grazia Leonello,1 Antonio Giacomo Rizzo,1 Viviane Di Dio,2 Antonio Soriano,3 Claudia Previti,3 Grazia Giulia Pantè,3 Claudio Mastrojeni,1 Sebastiano Pantè1 1Department of Human Pathology of Adults and Evolutive Era “Gaetano Barresi”, University of Messina, Messina, Italy; 2Health Research Institute Bonino Pulejo, Piemonte Hospital, Messina, Italy; 3Department of Medical and Surgery Science, University of Messina, Messina, Italy Abstract: Enteral nutrition (EN is preferred in order to provide nutrition and reduce catabolism in critically ill patients. Recent studies suggest that the use of EN is successful and complications are rare. However, an underestimated mechanical complication of tube feedings seen in critically ill patients is the coagulation and solidification of the EN causing gastrointestinal obstruction. This report describes two clinical cases (1.23% of all cases seen at our clinic of obstruction and perforation of the small bowel secondary to the solidification of EN. The understanding and early recognition of this potential complication are essential for the prevention and successful treatment of this condition. Keywords: enteral nutrition, gastrointestinal contents, intestinal obstruction, small-bowel bezoar

  8. Associations of Musculoskeletal Pain With Mobility in Older Adults: Potential Cerebral Mechanisms.

    Science.gov (United States)

    Cruz-Almeida, Yenisel; Rosso, Andrea; Marcum, Zachary; Harris, Tamara; Newman, Anne B; Nevitt, Michael; Satterfield, Suzanne; Yaffe, Kristine; Rosano, Caterina

    2017-09-01

    Musculoskeletal pain is highly prevalent and limits mobility in older adults. A potential mechanism by which pain affects mobility could be through its negative impact on the brain. We examined whether structural integrity of cerebral gray and white matter (WM) mediated the relationship between pain and mobility in community-dwelling older adults. Musculoskeletal pain, gait speed, and neuroimaging data were obtained concurrently from the Health ABC study (mean age = 83/56% female, n = 212). Microstructural gray matter integrity was measured by mean diffusivity (MD), WM microstructure and macrostructure were measured by fractional anisotropy (FA) and WM hyperintensities (WMH), respectively. Regression models were adjusted for gray matter atrophy, age, gender, medication use, and obesity. Bootstrapped mediation methods were used (1,000 bootstrapped samples, 95% confidence intervals). The associations of musculoskeletal pain with WMH (β = .19, p mobility, although pre-existing WM integrity may also simultaneously amplify pain and decrease mobility. Future studies are needed to further understand whether successful pain management may significantly improve both brain health and mobility. © The Author 2017. Published by Oxford University Press on behalf of The Gerontological Society of America. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  9. Interaction among hERG channel blockers is a potential mechanism of death in caffeine overdose.

    Science.gov (United States)

    Zheng, Jifeng; Zhao, Wei; Xu, Kai; Chen, Qingmao; Chen, Yingying; Shen, Yueliang; Xiao, Liping; Jiang, Liqin; Chen, Yuan

    2017-04-05

    Caffeine overdose death is due to cardiac arrest, but its mechanism has not been explored in detail. In this study, our data showed that caffeine significantly prolonged the heart rate-corrected QT interval (QTc) of rabbits in vivo (PCaffeine was also found to be a hERG channel blocker with an IC 50 of 5.04mM (n=5). Although these two findings likely link caffeine overdose death with hERG channel blockade, the amount of caffeine consumption needed to reach the IC 50 is very high. Further study demonstrated that addition another hERG blocker could lower the consumption of caffeine significantly, no matter whether two hERG blockers share the same binding sites. Our data does not rule out other possibility, however, it suggests that there is a potential causal relationship between caffeine overdose death with hERG channel and the interaction among these hERG blockers. Published by Elsevier B.V.

  10. Molecular characterization of HIV-1 subtype C gp-120 regions potentially involved in virus adaptive mechanisms.

    Directory of Open Access Journals (Sweden)

    Alessandra Cenci

    Full Text Available The role of variable regions of HIV-1 gp120 in immune escape of HIV has been investigated. However, there is scant information on how conserved gp120 regions contribute to virus escaping. Here we have studied how molecular sequence characteristics of conserved C3, C4 and V3 regions of clade C HIV-1 gp120 that are involved in HIV entry and are target of the immune response, are modulated during the disease course. We found an increase of "shifting" putative N-glycosylation sites (PNGSs in the α2 helix (in C3 and in C4 and an increase of sites under positive selection pressure in the α2 helix during the chronic stage of disease. These sites are close to CD4 and to co-receptor binding sites. We also found a negative correlation between electric charges of C3 and V4 during the late stage of disease counteracted by a positive correlation of electric charges of α2 helix and V5 during the same stage. These data allow us to hypothesize possible mechanisms of virus escape involving constant and variable regions of gp120. In particular, new mutations, including new PNGSs occurring near the CD4 and CCR5 binding sites could potentially affect receptor binding affinity and shield the virus from the immune response.

  11. Dysfunctional Hematopoietic Stem Cell Biology: Underlying Mechanisms and Potential Therapeutic Strategies

    Directory of Open Access Journals (Sweden)

    Anja Geiselhart

    2012-01-01

    Full Text Available Fanconi anemia (FA is the most common inherited bone marrow failure syndrome. FA patients suffer to varying degrees from a heterogeneous range of developmental defects and, in addition, have an increased likelihood of developing cancer. Almost all FA patients develop a severe, progressive bone marrow failure syndrome, which impacts upon the production of all hematopoietic lineages and, hence, is thought to be driven by a defect at the level of the hematopoietic stem cell (HSC. This hypothesis would also correlate with the very high incidence of MDS and AML that is observed in FA patients. In this paper, we discuss the evidence that supports the role of dysfunctional HSC biology in driving the etiology of the disease. Furthermore, we consider the different model systems currently available to study the biology of cells defective in the FA signaling pathway and how they are informative in terms of identifying the physiologic mediators of HSC depletion and dissecting their putative mechanism of action. Finally, we ask whether the insights gained using such disease models can be translated into potential novel therapeutic strategies for the treatment of the hematologic disorders in FA patients.

  12. Measuring short distance dispersal of Alliaria petiolata and determining potential long distance dispersal mechanisms

    Directory of Open Access Journals (Sweden)

    Christopher A. Loebach

    2018-03-01

    Full Text Available Introduction Alliaria petiolata, an herbaceous plant, has invaded woodlands in North America. Its ecology has been thoroughly studied, but an overlooked aspect of its biology is seed dispersal distances and mechanisms. We measured seed dispersal distances in the field and tested if epizoochory is a potential mechanism for long-distance seed dispersal. Methods Dispersal distances were measured by placing seed traps in a sector design around three seed point sources, which consisted of 15 second-year plants transplanted within a 0.25 m radius circle. Traps were placed at intervals ranging from 0.25–3.25 m from the point source. Traps remained in the field until a majority of seeds were dispersed. Eight probability density functions were fitted to seed trap counts via maximum likelihood. Epizoochory was tested as a potential seed dispersal mechanism for A. petiolata through a combination of field and laboratory experiments. To test if small mammals transport A. petiolata seeds in their fur, experimental blocks were placed around dense A. petiolata patches. Each block contained a mammal inclusion treatment (MIT and control. The MIT consisted of a wood-frame (31 × 61× 31 cm covered in wire mesh, except for the two 31 × 31 cm ends, placed over a germination tray filled with potting soil. A pan filled with bait was placed in the center of the tray. The control frame (11 × 31 × 61 cm was placed over a germination tray and completely covered in wire mesh to exclude animal activity. Treatments were in the field for peak seed dispersal. In March, trays were moved to a greenhouse and A. petiolata seedlings were counted and then compared between treatments. To determine if A. petiolata seeds attach to raccoon (Procyon lotor and white-tailed deer (Odocoileus virginianus fur, wet and dry seeds were dropped onto wet and dry fur. Furs were rotated 180 degrees and the seeds that remained attached were counted. To measure seed retention, seeds

  13. Reconsideration of atmospheric CO2 lifetime: potential mechanism for explaining CO2 missing sink

    Science.gov (United States)

    Kikuchi, R.; Gorbacheva, T.; Gerardo, R.

    2009-04-01

    Carbon cycle data (Intergovernmental Panel on Climate Change 1996) indicate that fossil fuel use accounts for emissions to the atmosphere of 5.5±0.5 GtC (Gigatons of carbon) annually. Other important processes in the global CO2 budget are tropical deforestation, estimated to generate about 1.6±1.0 GtC/yr; absorption by the oceans, removing about 2.0±0.8 GtC/yr; and regrowth of northern forests, taking up about 0.5±0.5 GtC/yr. However, accurate measurements of CO2 show that the atmosphere is accumulating only about 3.3±0.2 GtC/yr. The imbalance of about 1.3±1.5 GtC/yr, termed the "missing sink", represents the difference between the estimated sources and the estimated sinks of CO2; that is, we do not know where all of the anthropogenic CO2 is going. Several potential mechanisms have been proposed to explain this missing carbon, such as CO2 fertilization, climate change, nitrogen deposition, land use change, forest regrowth et al. Considering the complexity of ecosystem, most of ecosystem model cannot handle all the potential mechanisms to reproduce the real world. It has been believed that the dominant sink mechanism is the fertilizing effects of increased CO2 concentrations in the atmosphere and the addition to soils of fixed nitrogen from fossil-fuel burning and agricultural fertilizers. However, a recent analysis of long-term observations of the change in biomass and growth rates suggests that such fertilization effects are much too small to explain more than a small fraction of the observed sink. In addition, long-term experiments in which small forest patches and other land ecosystems have been exposed to elevated CO2 levels for extended periods show a rapid decrease of the fertilization effect after an initial enhancement. We will explore this question of the missing sink in atmospheric CO2 residence time. Radioactive and stable carbon isotopes (13-C/12-C) show the real CO2 lifetime is about 5 years; i.e. CO2 is quickly taken out of the atmospheric

  14. Effects of Dietary Lipid Levels on Growth Performance, Apparent Digestibility Coefficients of Nutrients, and Blood Characteristics of Juvenile Crucian Carp (Carassius auratus gibelio)

    OpenAIRE

    Wang, Aimin; Han, Guangming; Lv, Fu; Yang, Wenping; Huang, Jintian; Yin, Xiaoling

    2014-01-01

    In this study, the effects of dietary lipid levels on growth, apparent digestibility, and blood biochemical indices of juveniles crucian carp (Carassius auratus gibelio) were evaluated. Triplicate groups of fish (average weight 2.05±0.02 g) were fed four isonitrogenous experimental diets formulated with increasing levels (13.6, 61.3, 115, and 259.8 g kg-1) of lipid. The weight gain (WG), specific growth rate (SGR) was highest in fish fed 115 g kg-1 of lipid, the WG and SGR of 259.8 g kg-1 lip...

  15. Diet-induced lipid accumulation in phospholipid transfer protein-deficient mice: its atherogenicity and potential mechanism[S

    Science.gov (United States)

    Yeang, Calvin; Qin, Shucun; Chen, Kailian; Wang, David Q-H.; Jiang, Xian-Cheng

    2010-01-01

    A high saturated fat diet induces free cholesterol and phospholipid accumulation in the plasma of phospholipid transfer protein (Pltp)-deficient mice. In this study, we examined the atherogenic consequence of this phenomenon and investigated the possible mechanism(s). Pltp KO/Apoe KO mice that were fed a coconut oil-enriched high-fat diet (COD) for 7 weeks had higher plasma free cholesterol (149%), phospholipids (15%), and sphingomyelin (54%) than Apoe KO controls. In contrast to chow-fed animals, COD-fed Pltp KO/Apoe KO mice had the same atherosclerotic lesion size as that of Apoe KO mice. Similar to Pltp KO mice, plasma from COD-fed Pltp KO/Apoe KO mice contained VLDL/LDL-sized lamellar particles. Bile measurement indicated that COD-fed Pltp KO mice have 33% less hepatic cholesterol output than controls. In conclusion, COD-fed, Pltp-deficient mice are no longer protected from atherosclerosis and have impaired biliary lipid secretion, which is associated with free cholesterol and phospholipid accumulation. PMID:20543142

  16. Gene expression profile analysis of colorectal cancer to investigate potential mechanisms using bioinformatics

    Directory of Open Access Journals (Sweden)

    Kou YB

    2015-04-01

    phosphorylation and Parkinson’s disease. DEGs, such as FOS, FN1, PPP1CC, and CYP2B6, may be used as potential targets for CRC diagnosis and treatment. Keywords: molecular mechanisms, network module, enrichment analysis

  17. Assessing the potential of surrogate EPS to mimic natural biofilm mechanical properties

    Science.gov (United States)

    Thom, Moritz; Schimmels, Stefan

    2017-04-01

    Biofilms growing on benthic sediments may increase the resistance towards erosion considerably by the sticky nature of extracellular polymeric substances (EPS). The EPS is a biopolymer which is secreted by the microorganisms inhabiting the biofilm matrix and may be regarded as natural glue. However, laboratory studies on the biostabilization effect mediated by biofilms are often hampered by the unavailability of "environmental" flumes in which light intensities, water temperature and nutrient content can be controlled. To allow investigations on biostabilization in "traditional" flume settings the use of surrogate materials is studied. Another advantage of using appropriate surrogates is the potential to reduce the experimental time, as compared to cultivating natural biofilms, the surrogates can readily be designed to mimic biofilms at different growth stages. Furthermore, the use of surrogates which are expected to have more homogeneous mechanical properties could facilitate fundamental studies to improve our knowledge on biostabilization. Even though a number of studies have already utilized EPS surrogates it is not clear how to mix them to correctly mimic natural EPS mechanical properties. In this study the adhesiveness (a measure of stickiness) on the surface of several EPS surrogates (e.g. Xanthan Gum, sodium alginate) is measured. These surrogates which are originally used in the food industry as rheology modifiers are mixed by adding water to a powder at a desired concentration (C). The measured surface adhesion of different surrogates at different concentrations ranged from 0.5 to 6.7 N/m2, which is well in line with values found for laboratory cultured biofilms. We found that the surrogate characteristics differed largely especially in regard to a) the response of the adhesiveness to increased concentrations (powder to water) and b) in their rheological characteristics. A seemingly promising surrogate for the use in biostabilization studies is Xanthan Gum

  18. Homogenization mechanism of the residual surface potential of insulating specimens under electron beam irradiation

    International Nuclear Information System (INIS)

    Li Jingjing; Zhang Haibo; Feng Renjian

    2007-01-01

    A homogenized surface potential is desirable for the observation of a pre-irradiated insulating specimen using a scanning electron microscope because the residual surface potential may affect the imaging properties of the specimen. To homogenize the residual surface potential, the specimen should be subjected to the irradiation of an electron beam with the total electron yield greater than one. The expression of the equilibrium potential is derived based on the charge balance condition in the equilibrium state and the potential value is found to increase mainly with the secondary electron (SE) yield and the most probable emission energy of SEs. Further numerical calculations of SE trajectories show that affected by different surface potentials, SEs leave or return to the specimen surface to change the net charge flux into the specimen. This thereby increases the surface potential below the equilibrium potential and decreases that above the equilibrium potential, homogenizing the surface potential

  19. Using Molecular Docking Analysis to Discovery Dregea sinensis Hemsl. Potential Mechanism of Anticancer, Antidepression, and Immunoregulation.

    Science.gov (United States)

    Liu, Xiujie; Shi, Yu; Deng, Yulin; Dai, Rongji

    2017-01-01

    Dregea sinensis Hemsl. plant of the genus Dregea volubilis (Asclepiadaceae), plays a vital role in anticancer, antidepression, and immunoregulation. Steroidal glycosides are the main constituents of this herb, which were significant biological active ingredients. The objective of this study is to recognize the mechanism of anticancer, antidepression, and immunoregulation of D. sinensis Hemsl. Seventy-two steroidal glycosides of D. sinensis Hemsl. were evaluated on the docking behavior of tumor-associated proteins (PI3K, Akt, mTOR), depression-related proteins (MAO-A, MAO-B) and immune-related proteins (tumor necrosis factor-α [TNF-α], tumor necrosis factor receptor 2 [TNFR2], interleukin-2Rα [IL-2Rα]) using Discovery Studio version 3.1 (Accelrys, San Diego, USA). The molecular docking analysis revealed that mostly steroidal glycosides of D. sinensis Hemsl. exhibited powerful interaction with the depression-related protein (MAO-A) and the immune-related proteins (TNFR2, IL-2Rα). Some ligands exhibited high binding energy for the tumor-associated proteins (PI3K, Akt, mTOR) and the immune-related protein (TNF-α), but MAO-B showed none interaction with the ligands. This study has paved better understanding of steroidal glycosides from D. sinensis Hemsl. as potential constituents to the prevention of associated cancer, depression and disorders of immunoregulation. The ligand database was consist of 72 steroidal glycosides from Dregea sinensis HemslSteroidal glycosides had the potential to dock with the tumor-associated proteins (PI3K, Akt, mTOR)Steroidal glycosides were bounded with MAO-A rather than MAO-B, accorded with the inhibitor selectivity of MAOs, can be considered as potent candidate inhibitors of MAO-A72 ligands got high interaction with TNFR2 and IL-2Rα, regard the steroidal glycoside as powerful candidate inhibitors of TNFR2 and IL-2Rα. Abbreviations used: PI3K: Phosphatidyl inositol 3-kinase; Akt: Protein kinase B; mTOR: Mammalian target of

  20. Semicarbazide-induced thyroid disruption in Japanese flounder (Paralichthys olivaceus) and its potential mechanisms.

    Science.gov (United States)

    Yue, Zonghao; Yu, Miao; Zhang, Xiaona; Dong, Yifei; Tian, Hua; Wang, Wei; Ru, Shaoguo

    2017-06-01

    Semicarbazide (SMC) is a carcinogenic and genotoxic substance that has been found in aquatic systems. SMC may also cause thyroid follicular epithelial cell injury in rats, but the thyroid-disrupting properties of SMC and its potential mechanisms remain unclear. In this study, we exposed fertilized eggs of Japanese flounder (Paralichthys olivaceus) to 1, 10, 100, and 1000μg/L SMC for 55 d to assess the impact of SMC exposure on the thyroid system. The number of larvae in each metamorphic stage was counted, the concentrations of whole-body thyroid hormones (THs) 3,5,3'-triiodothyronine (T3) and thyroxine (T4) were measured, and the transcription levels of genes involved in the hypothalamic-pituitary-thyroid (HPT) axis and gamma-aminobutyric acid (GABA) synthesis were quantified. The results showed that 10μg/L SMC significantly increased whole-body T3 levels, and 100 and 1000μg/L SMC markedly enhanced whole-body T4 and T3 levels. Furthermore, 100μg/L SMC exposure shortened the time it took for flounder larvae to complete metamorphosis by 2 d as compared to the control group. Thus, this study demonstrated that SMC exerted thyroid-disrupting effects on Japanese flounder. SMC-mediated stimulation of TH levels was primarily related to transcriptional alterations of pituitary-derived thyroid stimulating hormone β-subunit (tshβ) and hepatic deiodinase (id). In the 10 and 100μg/L SMC exposure groups, the increased TH levels may have resulted from inhibition of TH metabolism caused by down-regulation of id3 mRNA expression, while at 1000μg/L SMC-exposed group, up-regulation of tshβ and id1 transcripts was expected to enhance the synthesis of T4 and the conversion of T4 to T3 and, consequently, result in higher T4 and T3 levels. In addition, 1000μg/L SMC-induced down-regulation in glutamic acid decarboxylase gad65 and gad67 transcription may have also contributed to the increased TH levels. The thyroid-disrupting effects of 10 and 100μg/L SMC indicated that

  1. Anticancer activity and potential mechanisms of 1C, a ginseng saponin derivative, on prostate cancer cells

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    Xu De Wang

    2018-04-01

    Full Text Available Background: AD-2 (20(R-dammarane-3b, 12b, 20, 25-tetrol; 25-OH-PPD is a ginsenoside and isolated from Panax ginseng, showing anticancer activity against extensive human cancer cell lines. In this study, effects and mechanisms of 1C ((20R-3b-O-(L-alanyl-dammarane-12b, 20, 25-triol, a modified version of AD-2, were evaluated for its development as a novel anticancer drug. Methods: MTT assay was performed to evaluate cell cytotoxic activity. Cell cycle and levels of reactive oxygen species (ROS were determined using flow cytometry analysis. Western blotting was employed to analyze signaling pathways. Results: 1C concentration-dependently reduces prostate cancer cell viability without affecting normal human gastric epithelial cell line-1 viability. In LNCaP prostate cancer cells, 1C triggered apoptosis via Bcl-2 family-mediated mitochondria pathway, downregulated expression of mouse double minute 2, upregulated expression of p53 and stimulated ROS production. ROS scavenger, N-acetylcysteine, can attenuate 1C-induced apoptosis. 1C also inhibited the proliferation of LNCaP cells through inhibition on Wnt/β-catenin signaling pathway. Conclusion: 1C shows obvious anticancer activity based on inducing cell apoptosis by Bcl-2 family-mediated mitochondria pathway and ROS production, inhibiting Wnt/β-catenin signaling pathway. These findings demonstrate that 1C may provide leads as a potential agent for cancer therapy. Keywords: 1C, AD-2, apoptosis, reactive oxygen species, Wnt/β-catenin pathway

  2. Protective effects and potential mechanisms of Pien Tze Huang on cerebral chronic ischemia and hypertensive stroke

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    Kwong Wing

    2010-10-01

    Full Text Available Abstract Background Stroke caused by brain ischemia is the third leading cause of adult disability. Active prevention and early treatment of stroke targeting the causes and risk factors may decrease its incidence, mortality and subsequent disability. Pien Tze Huang (PZH, a Chinese medicine formula, was found to have anti-edema, anti-inflammatory and anti-thrombotic effects that can prevent brain damage. This study aims to investigate the potential mechanisms of the preventive effects of Pien Tze Huang on brain damage caused by chronic ischemia and hypertensive stroke in rats. Methods The effects of Pien Tze Huang on brain protein expression in spontaneously hypertensive rat (SHR and stroke prone SHR (SHRsp were studied with 2-D gel electrophoresis and mass spectrometric analysis with a matrix-assisted laser desorption/ionization time-of-flight (MALDI-TOF/TOF tandem mass spectrometer and on brain cell death with enzyme link immunosorbent assay (ELISA and immunostaining. Results Pien Tze Huang decreased cell death in hippocampus and cerebellum caused by chronic ischemia and hypertensive stroke. Immunostaining of caspase-3 results indicated that Pien Tze Huang prevents brain cells from apoptosis caused by ischemia. Brain protein expression results suggested that Pien Tze Huang downregulated QCR2 in the electron transfer chain of mitochondria preventing reactive oxygen species (ROS damage and possibly subsequent cell death (caspase 3 assay as caused by chronic ischemia or hypertensive stroke to hippocampus and cerebellum. Conclusion Pien Tze Huang showed preventive effects on limiting the damage or injury caused by chronic ischemia and hypertensive stroke in rats. The effect of Pien Tze Huang was possibly related to prevention of cell death from apoptosis or ROS/oxidative damage in mitochondria.

  3. Mitochondrial Protection and Anti-aging Activity of Astragalus Polysaccharides and Their Potential Mechanism

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    Xiao-Juan Xin

    2012-02-01

    Full Text Available The current study was performed to investigate mitochondrial protection and anti-aging activity of Astragalus polysaccharides (APS and the potential underlying mechanism. Lipid peroxidation of liver and brain mitochondria was induced by Fe2+–Vit C in vitro. Thiobarbituric acid (TBA colorimetry was used to measure the content of thiobarbituric acid reactive substances (TBARS. Mouse liver mitochondrial permeability transition (PT was induced by calcium overload in vitro and spectrophotometry was used to measure it. The scavenging activities of APS on superoxide anion (O2•- and hydroxyl radical (•OH, which were produced by reduced nicotinamide adenine dinucleotide (NADH—N-Methylphenazonium methyl sulfate (PMS and hydrogen peroxide (H2O2–Fe2+ system respectively, were measured by 4-nitrobluetetrazolium chloride (NBT reduction and Fenton reaction colorimetry respectively. The Na2S2O3 titration method was used to measure the scavenging activities of APS on H2O2. APS could inhibit TBARS production, protect mitochondria from PT, and scavenge O2•-, •OH and H2O2 significantly in a concentration-dependent manner respectively. The back of the neck of mice was injected subcutaneously with D-galactose to induce aging at a dose of 100 mg/kg/d for seven weeks. Moreover, the activities of catalase (CAT, surperoxide dismutase (SOD and glutathione peroxidase (GPx and anti-hydroxyl radical which were assayed by using commercial monitoring kits were increased significantly in vivo by APS. According to this research, APS protects mitochondria by scavenging reactive oxygen species (ROS, inhibiting mitochondrial PT and increasing the activities of antioxidases. Therefore, APS has the effect of promoting health.

  4. Effects of Danshen tablets on pharmacokinetics of atorvastatin calcium in rats and its potential mechanism.

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    Sun, Sen; Wang, Rong; Fan, Jie; Zhang, Guoqing; Zhang, Hai

    2018-12-01

    Danshen tablets (DST), an effective traditional Chinese multi-herbal formula, are often combined with atorvastatin calcium (AC) for treating coronary heart disease in the clinic. This study investigated the effects of DST on the pharmacokinetics of AC and the potential mechanism. The pharmacokinetics of AC (1 mg/kg) with or without pretreatment of DST (100 mg/kg) were investigated using LC-MS/MS. The effects of DST (50 μg/mL) on the metabolic stability of AC were also investigated using rat liver microsome incubation systems. The results indicated that C max (23.87 ± 4.27 vs. 38.94 ± 5.32 ng/mL), AUC (0- t ) (41.01 ± 11.32 vs. 77.28 ± 12.92 ng h/mL), and t 1/2 (1.91 ± 0.18 vs. 2.74 ± 0.23 h) decreased significantly (p < 0.05) when DST and AC were co-administered, which suggested that DST might influence the pharmacokinetic behavior of AC when they are co-administered. The metabolic stability (t 1/2 ) of AC was also decreased (25.7 ± 5.2 vs. 42.5 ± 6.1) with the pretreatment of DST. This study indicated that the main components in DST could accelerate the metabolism of AC in rat liver microsomes and change the pharmacokinetic behaviors of AC. So these results showed that the herb-drug interaction between DST and AC might occur when they were co-administered. Therefore, the clinical dose of AC should be adjusted when DST and AC are co-administered.

  5. Nanobodies targeting norovirus capsid reveal functional epitopes and potential mechanisms of neutralization.

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    Anna D Koromyslova

    2017-11-01

    Full Text Available Norovirus is the leading cause of gastroenteritis worldwide. Despite recent developments in norovirus propagation in cell culture, these viruses are still challenging to grow routinely. Moreover, little is known on how norovirus infects the host cells, except that histo-blood group antigens (HBGAs are important binding factors for infection and cell entry. Antibodies that bind at the HBGA pocket and block attachment to HBGAs are believed to neutralize the virus. However, additional neutralization epitopes elsewhere on the capsid likely exist and impeding the intrinsic structural dynamics of the capsid could be equally important. In the current study, we investigated a panel of Nanobodies in order to probe functional epitopes that could trigger capsid rearrangement and/ or interfere with HBGA binding interactions. The precise binding sites of six Nanobodies (Nano-4, Nano-14, Nano-26, Nano-27, Nano-32, and Nano-42 were identified using X-ray crystallography. We showed that these Nanobodies bound on the top, side, and bottom of the norovirus protruding domain. The impact of Nanobody binding on norovirus capsid morphology was analyzed using electron microscopy and dynamic light scattering. We discovered that distinct Nanobody epitopes were associated with varied changes in particle structural integrity and assembly. Interestingly, certain Nanobody-induced capsid morphological changes lead to the capsid protein degradation and viral RNA exposure. Moreover, Nanobodies employed multiple inhibition mechanisms to prevent norovirus attachment to HBGAs, which included steric obstruction (Nano-14, allosteric interference (Nano-32, and violation of normal capsid morphology (Nano-26 and Nano-85. Finally, we showed that two Nanobodies (Nano-26 and Nano-85 not only compromised capsid integrity and inhibited VLPs attachment to HBGAs, but also recognized a broad panel of norovirus genotypes with high affinities. Consequently, Nano-26 and Nano-85 have a great

  6. Nanobodies targeting norovirus capsid reveal functional epitopes and potential mechanisms of neutralization

    Science.gov (United States)

    2017-01-01

    Norovirus is the leading cause of gastroenteritis worldwide. Despite recent developments in norovirus propagation in cell culture, these viruses are still challenging to grow routinely. Moreover, little is known on how norovirus infects the host cells, except that histo-blood group antigens (HBGAs) are important binding factors for infection and cell entry. Antibodies that bind at the HBGA pocket and block attachment to HBGAs are believed to neutralize the virus. However, additional neutralization epitopes elsewhere on the capsid likely exist and impeding the intrinsic structural dynamics of the capsid could be equally important. In the current study, we investigated a panel of Nanobodies in order to probe functional epitopes that could trigger capsid rearrangement and/ or interfere with HBGA binding interactions. The precise binding sites of six Nanobodies (Nano-4, Nano-14, Nano-26, Nano-27, Nano-32, and Nano-42) were identified using X-ray crystallography. We showed that these Nanobodies bound on the top, side, and bottom of the norovirus protruding domain. The impact of Nanobody binding on norovirus capsid morphology was analyzed using electron microscopy and dynamic light scattering. We discovered that distinct Nanobody epitopes were associated with varied changes in particle structural integrity and assembly. Interestingly, certain Nanobody-induced capsid morphological changes lead to the capsid protein degradation and viral RNA exposure. Moreover, Nanobodies employed multiple inhibition mechanisms to prevent norovirus attachment to HBGAs, which included steric obstruction (Nano-14), allosteric interference (Nano-32), and violation of normal capsid morphology (Nano-26 and Nano-85). Finally, we showed that two Nanobodies (Nano-26 and Nano-85) not only compromised capsid integrity and inhibited VLPs attachment to HBGAs, but also recognized a broad panel of norovirus genotypes with high affinities. Consequently, Nano-26 and Nano-85 have a great potential to

  7. Xenoestrogens elicit a modulation of endocannabinoid system and estrogen receptors in 4NP treated goldfish, Carassius auratus.

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    Pomatto, Valentina; Palermo, Francesco; Mosconi, Gilberto; Cottone, Erika; Cocci, Paolo; Nabissi, Massimo; Borgio, Luca; Polzonetti-Magni, Alberta M; Franzoni, Maria Fosca

    2011-10-01

    Based on pharmacological, behavioral and neuroanatomical studies, the endocannabinoids appear to be pivotal in some important neuroendocrine regulations of both vertebrates and invertebrates. Interestingly, a well developed endocannabinoid system was recently demonstrated by us in different bonyfish brain areas which control reproduction, energy balance and stress. Fish in particular are very sensitive to different types of stressors which can heavily affect their reproductive activity and negatively reverberate on aquaculture. Since recent new data have been reported on endocrine disruptors (EDs) impact on zebrafish receptor CB1 expression, in the present research we have investigated the response of the endocannabinoid system to acute treatment with an environmental stressor such as the xenoestrogen nonylphenol (4NP) in the brain and peripheral tissues of the goldfish Carassius auratus. First of all the estrogenic effects induced by 4NP were demonstrated by a dose-dependent increase of plasma levels and gene expression of the biomarker vitellogenin, then changes in cannabinoid receptors and anandamide degradative enzyme, the fatty acid amide hydrolase (FAAH), were analysed by means of Real Time PCR. As the exposure to EDs may lead to an activation of estrogen receptors and affects the Aromatase (AROB) transcription, changes in mRNA levels for ER subtypes and AROB were also evaluated. Our results confirm in goldfish the effect of 4NP on ERα and ERβ1 receptors and point out a different sensitivity of CB1 and CB2 for this compound, suggesting distinct roles of these cannabinoid receptors in some adaptive processes to contrast stress induced by xenoestrogen exposure. Copyright © 2011 Elsevier Inc. All rights reserved.

  8. Brain Mapping of Ghrelin O-Acyltransferase in Goldfish (Carassius Auratus): Novel Roles for the Ghrelinergic System in Fish?

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    Blanco, Ayelén M; Sánchez-Bretaño, Aída; Delgado, María J; Valenciano, Ana I

    2016-06-01

    Ghrelin O-acyltransferase (GOAT) is the enzyme responsible for acylation of ghrelin, a gut-brain hormone with important roles in many physiological functions in vertebrates. Many aspects of GOAT remain to be elucidated, especially in fish, and particularly its anatomical distribution within the different brain areas has never been reported to date. The present study aimed to characterize the brain mapping of GOAT using RT-qPCR and immunohistochemistry in a teleost, the goldfish (Carassius auratus). Results show that goat transcripts are expressed in different brain areas of the goldfish, with the highest levels in the vagal lobe. Using immunohistochemistry, we also report the presence of GOAT immunoreactive cells in different encephalic areas, including the telencephalon, some hypothalamic nuclei, pineal gland, optic tectum and cerebellum, although they are especially abundant in the hindbrain. Particularly, an important signal is observed in the vagal lobe and some fiber tracts of the brainstem, such as the medial longitudinal fasciculus, Mauthneri fasciculus, secondary gustatory tract and spinothalamic tract. Most of the forebrain areas where GOAT is detected, particularly the hypothalamic nuclei, also express the ghs-r1a ghrelin receptor and other appetite-regulating hormones (e.g., orexin and NPY), supporting the role of ghrelin as a modulator of food intake and energy balance in fish. Present results are the first report on the presence of GOAT in the brain using imaging techniques. The high presence of GOAT in the hindbrain is a novelty, and point to possible new functions for the ghrelinergic system in fish. Anat Rec, 299:748-758, 2016. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

  9. Determination of polychlorinated biphenyls and total mercury in two fish species (Esox lucius and Carassius auratus) in Anzali Wetland, Iran.

    Science.gov (United States)

    Sakizadeh, Mohammad; Esmaeili Sari, Abas; Abdoli, Asghar; Bahramifar, Nader; Hashemi, Seyed Hossein

    2012-05-01

    The Anzali Wetland is one of the most important ecosystems in the north of Iran, and parts of it were registered as a Ramsar site in 1975. However, even though, due to many problems, including eutrophication produced by inflow of excess nutrients and organic materials, the wetland was also listed on the Montreux Record indicating the need to take urgent remedial action. This study was conducted to study the levels of polychlorinated biphenyls (PCBs) and total mercury (THg) in two fish species (Esox lucius and Carassius auratus) as bio-indicators of the ecosystem condition in eastern part of Anzali Wetland. The sampling was carried out in six different periods between years 2009 and 2010. The results showed that the amounts of PCBs in the muscle of northern pike were below the detection limit of gas chromatography, whereas the average concentration in goldfish was 0.449 mg/kg wet weight. Some possible reasons for the higher levels of PCBs in goldfish in comparison with pike have been discussed. No significant (p < 0.05) correlation was observed between PCBs and biological factors (weight, length, lipid content) for both species. On the other hand, the mean concentration of THg in the muscle of pike and goldfish were 182.22 and 75.27 ng/g dry weight, respectively. Although these concentrations were below US-EPA criterion for human consumption (0.3 mg/kg), it pointed up a significant deterioration of the ecosystem condition during the past years. Finally, statistical analysis revealed a significant correlation between THg with weight and an insignificant correlation with length for pike specimens.

  10. Cutaneous myxosarcoma in a Syrian hamster (Mesocricetus auratusMixossarcoma cutâneo em um Hamster Sírio

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    Renée Laufer Amorim

    2011-08-01

    Full Text Available The pathological findings in a 2-years-old Syrian hamster (Mesocricetus auratus with a cutaneous myxosarcoma are described. Grossly, there was a large cutaneous mass in the right cervical region. Microscopical evaluation revealed a myxosarcoma characterized by pleomorphic, fusiform cells loosely arranged, randomly distributed, and presenting a moderate amount of basophilic amorphous stroma. There were hemorrhagic areas within the tumor. The basophilic amorphous stroma was positive to Alcian blue confirming the presence of a mucopolysaccharide matrix. Immunohistochemically, the neoplastic cells expressed vimentin, and were negative for cytokeratin or glial fibrillary acidic protein (GFAP.São descritos os achados anatomopatológicos de um caso de mixossarcoma cutâneo em um Hamster Sírio de 2 anos de idade. Macroscopicamente, foi evidenciada um grande massa cutânea na região cervical lateral direita. A microscopia revelou a presença de um caso de mixossarcoma caracterizado por células fusiformes pleomórficas, frouxamente arranjadas, distribuídas aleatoriamente e, apresentando quantidade moderada de substância basofílica amorfa no estroma e áreas hemorrágicas. O estroma basofílico amorfo foi positivo na coloração Alcian blue, confirmando a presença de matriz mucopolissacarídea. Na imunoistoquímica, as células neoplásicas expressaram vimentina e foram negativas para a marcação de citoqueratina e proteína ácida fibrilar (GFAP.

  11. Adolescent anabolic/androgenic steroids: Aggression and anxiety during exposure predict behavioral responding during withdrawal in Syrian hamsters (Mesocricetus auratus).

    Science.gov (United States)

    Ricci, Lesley A; Morrison, Thomas R; Melloni, Richard H

    2013-11-01

    In the U.S. and worldwide anabolic/androgenic steroid use remains high in the adolescent population. This is concerning given that anabolic/androgenic steroid use is associated with a higher incidence of aggressive behavior during exposure and anxiety during withdrawal. This study uses pubertal Syrian hamsters (Mesocricetus auratus) to investigate the hypothesis that an inverse behavioral relationship exists between anabolic/androgenic steroid-induced aggression and anxiety across adolescent exposure and withdrawal. In the first experiment, we examined aggression and anxiety during adolescent anabolic/androgenic steroid exposure and withdrawal. Adolescent anabolic/androgenic steroid administration produced significant increases in aggression and decreases in anxiety during the exposure period followed by significant decreases in aggression and increases in anxiety during anabolic/androgenic steroid withdrawal. In a second experiment, anabolic/androgenic steroid exposed animals were separated into groups based on their aggressive response during the exposure period and then tested for anxiety during exposure and then for both aggression and anxiety during withdrawal. Data were analyzed using a within-subjects repeated measures predictive analysis. Linear regression analysis revealed that the difference in aggressive responding between the anabolic/androgenic steroid exposure and withdrawal periods was a significant predictor of differences in anxiety for both days of testing. Moreover, the combined data suggest that the decrease in aggressive behavior from exposure to withdrawal predicts an increase in anxiety-like responding within these same animals during this time span. Together these findings indicate that early anabolic/androgenic steroid exposure has potent aggression- and anxiety-eliciting effects and that these behavioral changes occur alongside a predictive relationship that exists between these two behaviors over time. © 2013.

  12. Adolescent Anabolic/Androgenic Steroids: Aggression and Anxiety During Exposure Predict Behavioral Responding During Withdrawal in Syrian Hamsters (Mesocricetus auratus)

    Science.gov (United States)

    Ricci, Lesley A.; Morrison, Thomas R.; Melloni, Richard H.

    2014-01-01

    In the U.S. and worldwide anabolic/androgenic steroid use remains high in the adolescent population. This is concerning given that anabolic/androgenic steroid use is associated with a higher incidence of aggressive behavior during exposure and anxiety during withdrawal. This study uses pubertal Syrian hamsters (Mesocricetus auratus) to investigate the hypothesis that an inverse behavioral relationship exists between anabolic/androgenic steroid-induced aggression and anxiety across adolescent exposure and withdrawal. In the first experiment, we examined aggression and anxiety during adolescent anabolic/androgenic steroid exposure and withdrawal. Adolescent anabolic/androgenic steroid administration produced significant increases in aggression and decreases in anxiety during the exposure period followed by significant decreases in aggression and increases in anxiety during anabolic/androgenic steroid withdrawal. In a second experiment, anabolic/androgenic steroid exposed animals were separated into groups based on their aggressive response during the exposure period and then tested for anxiety during exposure and then for both aggression and anxiety during withdrawal. Data were analyzed using a within subjects repeated measures predictive analysis. Linear regression analysis revealed that the difference in aggressive responding between the anabolic/androgenic steroid exposure and withdrawal periods was a significant predictor of differences in anxiety for both days of testing. Moreover, the combined data suggest that the decrease in aggressive behavior from exposure to withdrawal predicts an increase in anxiety-like responding within these same animals during this time span. Together these findings indicate that early anabolic/androgenic steroid exposure has potent aggression- and anxiety- eliciting effects and that these behavioral changes occur alongside a predictive relationship that exists between these two behaviors over time. PMID:24126136

  13. Membrane phospholipid fatty acid composition regulates cardiac SERCA activity in a hibernator, the Syrian hamster (Mesocricetus auratus.

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    Sylvain Giroud

    Full Text Available Polyunsaturated fatty acids (PUFA have strong effects on hibernation and daily torpor. Increased dietary uptake of PUFA of the n-6 class, particularly of Linoleic acid (LA, C18:2 n-6 lengthens torpor bout duration and enables animals to reach lower body temperatures (T(b and metabolic rates. As previously hypothesized, this well-known influence of PUFA may be mediated via effects of the membrane fatty acid composition on sarcoplasmic reticulum (SR Ca(2+-ATPase 2a (SERCA in the heart of hibernators. We tested the hypotheses that high proportions of n-6 PUFA in general, or specifically high proportions of LA (C18:2 n-6 in SR phospholipids (PL should be associated with increased cardiac SERCA activity, and should allow animals to reach lower minimum T(b in torpor. We measured activity of SERCA from hearts of hibernating and non-hibernating Syrian hamsters (Mesocricetus auratus in vitro at 35 °C. Further, we determined the PL fatty acid composition of the SR membrane of these hearts. We found that SERCA activity strongly increased as the proportion of LA in SR PL increased but was negatively affected by the content of Docosahexaenoic acid (DHA; C22:6 n-3. SR PL from hibernating hamsters were characterized by high proportions of LA and low proportions of DHA. As a result, SERCA activity was significantly higher during entrance into torpor and in torpor compared to inter-bout arousal. Also, animals with increased SERCA activity reached lower T(b during torpor. Interestingly, a subgroup of hamsters which never entered torpor but remained euthermic throughout winter displayed a phenotype similar to animals in summer. This was characterized by lower proportions of LA and increased proportions of DHA in SR membranes, which is apparently incompatible with torpor. We conclude that the PUFA composition of SR membranes affects cardiac function via modulating SERCA activity, and hence determines the minimum T(b tolerated by hibernators.

  14. Radioactive tracers in the study of energy turnover by a grazing insect (Chrysochus auratus Fab. ; coleoptera chrysomelidae)

    Energy Technology Data Exchange (ETDEWEB)

    Williams, E.C. Jr.; Reichle, D.E.

    1968-01-01

    Radioisotope tags of rubidium-86 and phosphorus-32 were used to measure food consumption by the chrysomelid beetle Chrysochus auratus feeding upon the old field herb Apocynum cannabinum. The elimination of isotope by beetles which had fed upon tagged plants was used to estimate the rates of food consumption. For individuals at isotopic equilibrium with their food base, isotope input (I) equals the biological turnover of isotope: I = kQ/sub e/M/a, where k is the turnover rate of isotope, Q/sub e/ is the equilibrium concentration of isotope in the beetles, M is mass (mg dry wt), and a is the assimilation coefficient for the particular radioisotope. Turnover rates (k) were calculated from biological half-lives (T/sub b/), where k = 0.693/T/sub b/. The biological half-life of YWRb in Chrysochus was one day, while that of TSP was 7.5 days in females and 10.2 days in males. The calorific value of Apocynum leaves was 4625 cal/g dry wt (5640 cal/g ash-free wt); that of Chrysochus was 5227 cal/g dry wt (5537 cal/g ash-free wt). Individuals consumed 56.8% (15.9 mg) of their dry body weight in food per day. Of the ingested foliage, 43% of the ash-free dry matter was digested, 56% of the energy assimilated, and 71% of the ash content assimilated. The calorific value (cal/g) of digested food was 1.17 times greater than that consumed. Beetles assimilated 87% of the YWRb and 74% of the TSP present in food. Ranking of turnover times showed Chrysochus to be most conservative in its expenditure of food energy and dry matter, followed by mineral constituents. 9 references, 3 figures, 3 tables.

  15. Acupuncture therapy: mechanism of action, efficacy, and safety: a potential intervention for psychogenic disorders?

    Science.gov (United States)

    2014-01-01

    Scientific bases for the mechanism of action of acupuncture in the treatment of pain and the pathogenic mechanism of acupuncture points are briefly summarized. The efficacy and safety of acupuncture therapy is discussed based on the results of German clinical trials. A conclusion on the role for acupuncture in the treatment of psychogenic disorders could not be reached. PMID:24444292

  16. Mechanism of Formation of the Resource Potential of the Management and Organisation Enterprise Development: Strategic and Tactical Aspects

    Directory of Open Access Journals (Sweden)

    Slastianykova Anzhelika I.

    2014-02-01

    Full Text Available The article considers influence of factors – reasons of origination of crisis phenomena – upon resource potential with the aim of study of management and organisation enterprise development. It identifies that correlation of managed and unmanaged processes at an enterprise is achieved only through correct selection of tactical and strategic orientation, which should take into account specific features of various types of crises, and also the process of their deployment and ways of prevention and elimination. The article generalises influence of factors – reasons of origination of crisis phenomena – upon resource potential with the aim of study of the management and organisation development of an enterprise and building a mechanism. It improves a mechanism of formation of the resource potential of the management and organisation development of an enterprise at tactical and strategic levels. It allowed finding out that managerial impact on formation and maintenance of key factors influences the formation, management and application of the enterprise resource potential.

  17. The toxicity of cadmium to three aquatic organisms (Photobacterium phosphoreum, Daphnia magna and Carassius auratus) under different pH levels.

    Science.gov (United States)

    Qu, R-J; Wang, X-H; Feng, M-B; Li, Y; Liu, H-X; Wang, L-S; Wang, Z-Y

    2013-09-01

    This study investigated the effect of pH on cadmium toxicity to three aquatic organisms: Photobacterium phosphoreum, Daphnia magna and Carassius auratus. The acute toxicity of Cd(2+) to P. phosphoreum and D. magna at five pH values (5.0, 6.0, 7.0, 8.0, and 9.0) was assessed by calculating EC50 values. We determined that Cd(2+) was least toxic under acidic conditions, and D. magna was more sensitive to the toxicity of Cd than P. phosphoreum. To evaluate Cd(2+)-induced hepatic oxidative stress in C. auratus at three pH levels (5.0, 7.25, 9.0), the activity of antioxidant enzymes (superoxide dismutase, catalase and glutathione peroxidase), the level of glutathione and the malondialdehyde content in the liver were measured. Oxidative damage was observed after 7d Cd exposure at pH 9.0. An important finding of the current research was that Cd(2+) was generally more toxic to the three test organisms in alkaline environments than in acidic environments. Copyright © 2013 Elsevier Inc. All rights reserved.

  18. Combined or Individual Effects of Dietary Probiotic Pedicoccus acidilactici and Nucleotide on Growth Performance, Intestinal Microbiota, Hemato-biochemical Parameters, and Innate Immune Response in Goldfish (Carassius auratus).

    Science.gov (United States)

    Mehdinejad, Nooshin; Imanpour, Mohammad Reza; Jafari, Valiollah

    2017-06-21

    This study investigated the effect of dietary supplementation of probiotic Pedicoccus acidilactici and nucleotide (separately or combined) on growth performance, intestinal microbiota, hemato-immunological parameters, and immunity response in goldfish (Carassius auratus). Fish (average weight 5-6 g) were acclimatized and divided into eight experimental diets supplemented with P. acidilactici of different concentrations (0.1, 0.2, and 0.3% diet) and nucleotides (0 and 0.5% diet) for 6 months. Fish fed with experimental diets showed significant differences in terms of final weight, weight gain, feed conversion ratio, daily growth rate, and condition factor when compared to control diet (P < 0.05). Fish fed with probiotic (0.3%) separately and combined with nucleotide (0.5%) had highest RBC and WBC when compared to other diets (P < 0.05), while the highest values for Hb and Hct as well as total protein, glucose, albumin, and globulin were observed in probiotic (0.2%) and nucleotide (0.5%) combined diet. Serum lysozyme and anti-protease activities were significantly higher in probiotic (0.1 and 0.2%) and nucleotide (0.5%) combined diets. Similarly, these two diets combined showed the highest colonization of P. acidilactici when compared to other diets. In conclusion, combined dietary probiotic and nucleotide improve the growth performance, hemato-biochemical parameters, and intestine growth in C. auratus.

  19. Insight into potential mechanisms of hypobaric hypoxia-induced learning and memory deficit - Lessons from rat studies.

    Science.gov (United States)

    Qaid, Eya; Zakaria, R; Sulaiman, S F; Yusof, Na Mohd; Shafin, N; Othman, Z; Ahmad, A H; Aziz, Cb Abd

    2017-12-01

    Impairment of memory is one of the most frequently reported symptoms during sudden hypoxia exposure in human. Cortical atrophy has been linked to the impaired memory function and is suggested to occur with chronic high-altitude exposure. However, the precise molecular mechanism(s) of hypoxia-induced memory impairment remains an enigma. In this work, we review hypoxia-induced learning and memory deficit in human and rat studies. Based on data from rat studies using different protocols of continuous hypoxia, we try to elicit potential mechanisms of hypobaric hypoxia-induced memory deficit.

  20. Extended semen for artificial insemination in swine as a potential transmission mechanism for infectious Chlamydia suis.

    Science.gov (United States)

    Hamonic, G; Pasternak, J A; Käser, T; Meurens, F; Wilson, H L

    2016-09-01

    Although typically unnoticed, Chlamydia infections in swine have been shown to be both widespread and may impact production characteristics and reproductive performance in swine. Serum titers suggest Chlamydia infection within boar studs is common, and infected boars are known to shed chlamydia in their ejaculates. Although the transmission of viruses in chilled extended semen (ES) is well established, the inclusion of antibiotics in commercially available extender is generally believed to limit or preclude the transmission of infectious bacteria. The objective of this study was to evaluate the potential of ES used in artificial insemination to support transmission of the obligate intracellular bacteria Chlamydia suis (C suis) under standard industry conditions. First, the effect of C suis on sperm quality during storage was assessed by flow cytometry. Only concentrations above 5 × 10(5) viable C suis/mL caused significant spermicidal effects which only became evident after 7 days of storage at 17 °C. No significant effect on acrosome reaction was observed using any chlamydial concentration. Next, an in vitro infection model of swine testicular fibroblast cells was established and used to evaluate the effect of chilled storage on C suis viability under variable conditions. Storage in Androhep ES reduced viability by 34.4% at a multiplicity of infection of 1.25, an effect which increased to 53.3% when the multiplicity of infection decreased to 0.1. Interestingly, storage in semen extender alone (SE) or ES with additional antibiotics had no effect on bacterial viability. To rule out a secondary effect on extender resulting from metabolically active sperm, C suis was stored in fresh and expended SE and again no significant effect on bacterial viability was observed. Fluorescent microscopy of C suis in ES shows an association between bacteria and the remaining gel fraction after storage suggesting that the apparent reduction of bacterial viability in the presence

  1. Biomass Carbon in the South Mexican Pacific Coast: Exploring Mangrove Potential to REDD+ Mechanisms

    Science.gov (United States)

    Bejarano, M.; Amezcua-Torrijos, I.

    2014-12-01

    Mangroves have the highest carbon stocks amongst tropical forests. In Mexico, however, little is known about their potential to mitigate climate change. In this work, we estimated biomass carbon stocks in the Southern Mexican Pacific Coast (~69,000 ha). We quantified above and belowground biomass carbon stocks at (1) the regional scale along two environmental strata (i.e. dry and wet), and (2) at the local scale along three geomorphological types of mangroves (i.e. fringe, estuarine and basin). Regional strata were defined using intensity and influence of rivers and, the mean annual precipitation and evapotranspiration ratio (i.e., wet dry). By lowering the stressing environmental conditions (e.g., low salinity and high sediment accumulation), we expected the highest stocks in mangroves growing in wet and estuarine strata at the regional scale and local scale, respectively. Quantifications were carried out in sixty-six sites chosen through stratified randomized design in which six strata were obtained by a full combination of regional and local strata. In all strata, aboveground carbon represents 64-67% of total carbon. Total biomass carbon was higher in wet than dry stratum (W: 87.3 ± 6.9, D: 47.0 ± 5.0, p<0.001). While at local scale, total biomass carbon was high in estuarine mangroves of both wet and dry regions (W: 91.6 ± 7.8, D: 77.6 ± 14.8, p<0.001), and these were statistically similar to fringe wet mangroves (110.9 ± 24.2, p<0.001), the stratum with the highest total carbon. Following a conservative approach, the Mexican Southern Pacific Coast is storing near 20,344 Gg CO2e. If the historical annual deforestation rate of 0.54% continues, this region could emit between 0.03 and 14.4 Gg of CO2e ha/year, out of which wet estuarine mangroves would have the highest emission values. Evidence suggests that these mangroves are the most important strata in which REDD+ mechanisms could be implemented due to (1) their carbon stocks, and (2) their highest

  2. Potential treatment mechanisms in a mindfulness-based intervention for people with progressive multiple sclerosis.

    Science.gov (United States)

    Bogosian, Angeliki; Hughes, Alicia; Norton, Sam; Silber, Eli; Moss-Morris, Rona

    2016-11-01

    To explore putative mediators of a mindfulness-based intervention to decrease distress in people with multiple sclerosis (MS) and to explore the patients' perspectives on this intervention. We used an explanatory mixed methods design incorporating quantitative data from a pilot randomized control trial and a qualitative interview study with people who completed the mindfulness intervention. People with MS (n = 40) completed standardized measures of distress (outcome), and acceptance, decentring, self-compassion, and self-efficacy (potential mediators). Semi-structured interviews (n = 15) of patients' experiences of the mindfulness intervention were analysed deductively and inductively. Decentring post-intervention explained 13% of the 3-month change in distress and between 27% and 31% of concurrent changes in distress. Acceptance changed only slightly, and as a result, the indirect effect accounts for only 2% of future distress and between 3% and 11% of concurrent distress. Qualitative data showed that acceptance and self-compassion needed more time to develop, whereas decentring could be implemented readily after being introduced in the sessions. Self-efficacy also had a large mediating effect. Participants in their interviews talked about group dynamics and prior expectations as essential elements that determine their engagement with the course and their level of satisfaction. Mindfulness interventions for people with a chronic progressive condition may benefit from focusing on helping them to accept daily challenges and teach them to recognize their thoughts and feelings, allowing time for acceptance and self-compassion to develop. Group dynamics also play a fundamental role in the success of the mindfulness interventions. Statement of Contribution What is already known on this subject? Mindfulness courses improve psychological well-being for people with chronic conditions. Mindfulness courses have been successful in improving psychological well-being and

  3. Immune responses to live and inactivated Nocardia seriolae and protective effect of recombinant interferon gamma (rIFN γ) against nocardiosis in ginbuna crucian carp, Carassius auratus langsdorfii.

    Science.gov (United States)

    Nayak, Sukanta Kumar; Shibasaki, Yasuhiro; Nakanishi, Teruyuki

    2014-08-01

    Looking into the fact that substantial mortality and morbidity is associated with intracellular Gram +ve bacterium, Nocardia seriolae infection, an effective vaccine against this pathogen is necessary to control the significant losses in aquaculture practices. Therefore, an attempt was made to evaluate the effect of live (sub-lethal) and inactivated (antigenic form) N. seriolae on cellular and humoral immunity in ginbuna crucian carp, Carassius auratus langsdorfii as well as the therapeutic potency of recombinant interferon gamma (rIFN γ) against N. seriolae infection. Effect of live and inactivated N. seriolae immunisation on the proliferation of CD4(+) T cells, CD8α(+) T cells and surface Ig M(+) cells in peripheral blood leucocytes, spleen, head kidney and trunk kidney of ginbuna was studied after 1st, 3rd, 7th, 15th and 30th day post immunisation. The percentage of CD8α(+) T cells in spleen and head kidney of ginbuna was significantly higher at 3rd day post immunisation. Similarly, surface Ig M(+) cells level was found to increase in both live and inactivated N. seriolae immunised groups. On the contrary, high percentage of CD4(+) T cells was observed in live N. seriolae immunised group in both the head and trunk kidneys at 30th day post immunisation. The humoral immune response to live and inactivated N. seriolae immunised ginbuna showed high antibody titre at 15th day post immunisation but the level declined subsequently in both the immunised groups. On challenge with virulent N. seriolae (1.2 × 10(8) CFU/ml), the relative percent survival was 62.5 and 75 in live and inactivated N. seriolae immunised groups, respectively. Furthermore, we have also studied the therapeutic potency of rIFN γ and found the possible involvement of IFN γ in resistance mechanism in fish. Administration of rIFN γ into ginbuna (at 10 μg/fish) one day before challenge study was found to protect ginbuna. The relative percent survival of ginbuna was 43.75 and 60 when

  4. Multiscale Mechanics of Articular Cartilage: Potentials and Challenges of Coupling Musculoskeletal, Joint, and Microscale Computational Models

    Science.gov (United States)

    Halloran, J. P.; Sibole, S.; van Donkelaar, C. C.; van Turnhout, M. C.; Oomens, C. W. J.; Weiss, J. A.; Guilak, F.; Erdemir, A.

    2012-01-01

    Articular cartilage experiences significant mechanical loads during daily activities. Healthy cartilage provides the capacity for load bearing and regulates the mechanobiological processes for tissue development, maintenance, and repair. Experimental studies at multiple scales have provided a fundamental understanding of macroscopic mechanical function, evaluation of the micromechanical environment of chondrocytes, and the foundations for mechanobiological response. In addition, computational models of cartilage have offered a concise description of experimental data at many spatial levels under healthy and diseased conditions, and have served to generate hypotheses for the mechanical and biological function. Further, modeling and simulation provides a platform for predictive risk assessment, management of dysfunction, as well as a means to relate multiple spatial scales. Simulation-based investigation of cartilage comes with many challenges including both the computational burden and often insufficient availability of data for model development and validation. This review outlines recent modeling and simulation approaches to understand cartilage function from a mechanical systems perspective, and illustrates pathways to associate mechanics with biological function. Computational representations at single scales are provided from the body down to the microstructure, along with attempts to explore multiscale mechanisms of load sharing that dictate the mechanical environment of the cartilage and chondrocytes. PMID:22648577

  5. Combining enamel matrix proteins with mechanical stimuli potentiates human periodontal ligament fibroblasts proliferation and periodontium remodeling.

    Science.gov (United States)

    Zou, Rui; Wan, Wanting; Li, Jingjing; Du, Chanyuan; Wang, Yijie; Qian, Tian; Niu, Lin

    2018-02-27

    Collagen I (Col-I) and matrix metalloproteinase-1 (MMP-1) have been implicated in the regeneration and remodeling of the periodontium. Studies have shown that enamel matrix proteins (EMPs) and mechanical stimuli can promote the synthesis and degradation, respectively, of Col-I and MMP-1. However, the effects of the combination of EMPs and mechanical stimuli on human periodontal ligament are not known. Our aim was to test the combined effects of EMPs and mechanical stimuli on the proliferation of human periodontal ligament fibroblasts (HPDLFs) and Col-I and MMP-1 mRNA expression. Primary HPDLFs were isolated using an enzyme digestion method. To select the optimum EMP concentration and the optimum magnitude and loading time of mechanical stimuli, HPDLFs were stimulated with gradient concentration of EMPs (0 µg/mL, 25 µg/mL, 50 µg/mL, 100 µg/mL and 200 µg/mL) and mechanical stimuli (0 kPa, 25 kPa, 50 kPa, 100 kPa, and 200 kPa for 0 h, 3 h, 6 h, 12 h, and 24 h), respectively. The cell proliferative response was tested by the MTT assay. The impact of EMPs combined with mechanical stimuli on Col-I and MMP-1 mRNA expression were measured by reverse transcription polymerase chain reaction. 100 µg/mL of EMPs and a 50 kPa mechanical stimulus were chosen as the optimum parameters due to the higher proliferation rates than other doses. The combination of 100 µg/mL of EMPs and a 50 kPa mechanical stimulus significantly stimulated HPDLFs proliferation and increased Col-I and MMP-1 expression levels compared with incubation with two factors alone. We concluded that the combination of EMPs and mechanical stimulus have synergistic effects on cell growth, cell number, collagen turnover, and periodontium remodeling.

  6. Formation of compensation mechanism of regional enterprises’ human resources regeneration in the labor potential development system

    OpenAIRE

    Alexeev, I.; Voloshyn, O.

    2013-01-01

    The article substantiates the formation principles of administration bodies in implementation of compensation mechanism of human resources regeneration. It defines stages of the preparatory period of forming administration bodies of human resources regeneration with the primary units for training and exploitation of human resources, for which was designed the organizational structure of enterprise’s personnel departments subdivisions. A model of a compensation mechanism for regeneration of...

  7. Pilot-scale UV/H2O2 advanced oxidation process for municipal reuse water: Assessing micropollutant degradation and estrogenic impacts on goldfish (Carassius auratus L.).

    Science.gov (United States)

    Shu, Zengquan; Singh, Arvinder; Klamerth, Nikolaus; McPhedran, Kerry; Bolton, James R; Belosevic, Miodrag; Gamal El-Din, Mohamed

    2016-09-15

    Low concentrations (ng/L-μg/L) of emerging micropollutant contaminants in municipal wastewater treatment plant effluents affect the possibility to reuse these waters. Many of those micropollutants elicit endocrine disrupting effects in aquatic organisms resulting in an alteration of the endocrine system. A potential candidate for tertiary municipal wastewater treatment of these micropollutants is ultraviolet (UV)/hydrogen peroxide (H2O2) as an advanced oxidation process (AOP) which was currently applied to treat the secondary effluent of the Gold Bar Wastewater Treatment Plant (GBWWTP) in Edmonton, AB, Canada. A new approach is presented to predict the fluence-based degradation rate constants (kf') of environmentally occurring micropollutants including carbamazepine [(0.87-1.39) × 10(-3) cm(2)/mJ] and 2,4-Dichlorophenoxyacetic acid (2,4-D) [(0.60-0.91) × 10(-3) cm(2)/mJ for 2,4-D] in a medium pressure (MP) UV/H2O2 system based on a previous bench-scale investigation. Rather than using removal rates, this approach can be used to estimate the performance of the MP UV/H2O2 process for degrading trace contaminants of concern found in municipal wastewater. In addition to the ability to track contaminant removal/degradation, evaluation of the MP UV/H2O2 process was also accomplished by identifying critical ecotoxicological endpoints (i.e., estrogenicity) of the treated wastewater. Using quantitative PCR, mRNA levels of estrogen-responsive (ER) genes ERα1, ERα2, ERβ1, ERβ2 and NPR as well as two aromatase encoding genes (CYP19a and CYP19b) in goldfish (Carassius auratus L.) were measured during exposure to the GBWWTP effluent before and after MP UV/H2O2 treatment (a fluence of 1000 mJ/cm(2) and 20 mg/L of H2O2) in spring, summer and fall. Elevated expression of estrogen-responsive genes in goldfish exposed to UV/H2O2 treated effluent (a 7-day exposure) suggested that the UV/H2O2 process may induce acute estrogenic disruption to goldfish principally because

  8. Competition between inverse piezoelectric effect and deformation potential mechanism in undoped GaAs revealed by ultrafast acoustics

    Directory of Open Access Journals (Sweden)

    Pezeril T.

    2013-03-01

    Full Text Available By using the picosecond ultrasonics technique, piezoelectric effect in GaAs undoped sample at both faces (A[111] and B[-1-1-1] is experimentally studied. We demonstrate that piezoelectric generation of sound can dominate in GaAs material over the deformation potential mechanism even in the absence of static externally applied or built-in electric field in the semiconductor material. In that case, the Dember field, caused by the separation of photo-generated electrons and holes in the process of supersonic diffusion, is sufficient for the dominance of the piezoelectric mechanism during the optoacoustic excitation. The experimental results on the sample at both faces reveal that in one case (A face, the two mechanisms, piezoelectric effect and deformation potential, can compensate each other leading to a large decrease of the measured Brillouin oscillation magnitude.

  9. Lifelong Bilingualism and Neural Reserve against Alzheimer’s disease: A Review of Findings and Potential Mechanisms

    Science.gov (United States)

    Gold, Brian T.

    2014-01-01

    Alzheimer’s disease (AD) is a progressive brain disorder that initially affects medial temporal lobe circuitry and memory functions. Current drug treatments have only modest effects on the symptomatic course of the disease. In contrast, a growing body of evidence suggests that lifelong bilingualism may delay the onset of clinical AD symptoms by several years. The purpose of the present review is to summarize evidence for bilingualism as a reserve variable against AD and discuss potential underlying neurocognitive mechanisms. Evidence is reviewed suggesting that bilingualism may delay clinical AD symptoms by protecting frontostriatal and frontoparietal executive control circuitry rather than medial temporal lobe memory circuitry. Cellular and molecular mechanisms that may contribute to bilingual cognitive reserve effects are discussed, including those that may affect neuronal metabolic functions, dynamic neuronal-glial interactions, vascular factors, myelin structure and neurochemical signaling. Future studies that may test some of these potential mechanisms of bilingual CR effects are proposed. PMID:25496781

  10. On the solution of an inverse problem for confining potentials in quantum mechanics

    International Nuclear Information System (INIS)

    Gostev, V.B.; Mineev, V.S.; Frenkin, A.R.

    1982-01-01

    The problem of plotting confining (unlimitedly increasing on the infinity) potentials of the central field by the given energy spectrum is discussed. The radial Schroedinger equation has pure discrete spectrum with infinite number of levels for these potentials. The problem is solved using the Helfand-Levitan equation with a certain reference potential V(r) for which spectral characteristics differ from the given ones only in the finite number of elements. The regular solutions PHIsub(l)(E, r) of the Schroedinger equation for the reference potential V(r) are supposed to be known. The initial potential and regular solutions of the Schroedinger equation are restored by the reference potential V(r) and regular PHIsub(l)(E, r) functions by means of the known formulas. It is observed from the paper data that confining potentials with any type of spectrum can be restored. Choice of the corresponding reference potential providing Fredholm nature of the Helfand-Levitan equation is the basic problem in this case

  11. Infection-Induced Thrombin Production: A Potential Novel Mechanism for Preterm Premature Rupture of Membranes (PPROM).

    Science.gov (United States)

    Feng, Liping; Allen, Terrence K; Marinello, William P; Murtha, Amy P

    2018-04-13

    decidua cells was perinuclear and cytoplasmic. Prothrombin mRNA and protein expression in fetal membranes was significantly increased by U. parvum, but not lipopolysaccharide, treatments in a dose-dependent manner. Specifically, U. parvum at a dose of 1x10 7 cfu/ml significantly increased both prothrombin mRNA (fold changes in amnion: 4.1±1.9; chorion: 5.7±4.2; decidua: 10.0±5.4; FM: 9.2±3.0) and protein expression (fold changes in amnion: 138.0±44.0; chorion: 139.6±15.1; decidua: 56.9±29.1; fetal membrane: 133.1±40.0) compared to untreated controls. U. parvum at a dose of 1x10 6 cfu/ml significantly upregulated prothrombin protein expression in chorion cells (fold change: 54.9±5.3) and prothrombin mRNA expression in decidua cells (fold change: 4.4±1.9). Our results demonstrate that prothrombin can be directly produced by fetal membrane amnion, chorion, and decidua cells. Further, prothrombin production can be stimulated by U. parvum exposure in fetal membranes. These findings represent a potential novel underlying mechanism of U. parvum-induced rupture of fetal membranes. Copyright © 2018 Elsevier Inc. All rights reserved.

  12. Bone and skeletal muscle: Key players in mechanotransduction and potential overlapping mechanisms.

    Science.gov (United States)

    Goodman, Craig A; Hornberger, Troy A; Robling, Alexander G

    2015-11-01

    The development and maintenance of skeletal muscle and bone mass is critical for movement, health and issues associated with the quality of life. Skeletal muscle and bone mass are regulated by a variety of factors that include changes in mechanical loading. Moreover, bone mass is, in large part, regulated by muscle-derived mechanical forces and thus by changes in muscle mass/strength. A thorough understanding of the cellular mechanism(s) responsible for mechanotransduction in bone and skeletal muscle is essential for the development of effective exercise and pharmaceutical strategies aimed at increasing, and/or preventing the loss of, mass in these tissues. Thus, in this review we will attempt to summarize the current evidence for the major molecular mechanisms involved in mechanotransduction in skeletal muscle and bone. By examining the differences and similarities in mechanotransduction between these two tissues, it is hoped that this review will stimulate new insights and ideas for future research and promote collaboration between bone and muscle biologists.(1). Copyright © 2015 Elsevier Inc. All rights reserved.

  13. Potential neural mechanisms underlying the effectiveness of early intervention for children with autism spectrum disorder

    Science.gov (United States)

    Sullivan, Katherine; Stone, Wendy L.; Dawson, Geraldine

    2014-01-01

    Although evidence supports the efficacy of early intervention for improving outcomes for children with autism spectrum disorder (ASD), the mechanisms underlying their effectiveness remain poorly understood. This paper reviews the research literature on the neural bases of the early core deficits in ASD and proposes three key features of early intervention related to the neural mechanisms that may contribute to its effectiveness in improving deficit areas. These features include (1) the early onset of intensive intervention which capitalizes on the experience-expectant plasticity of the immature brain, (2) the use of treatment strategies that address core deficits in social motivation through an emphasis on positive social engagement and arousal modulation, and (3) promotion of complex neural networks and connectivity through thematic, multi-sensory and multi-domain teaching approaches. Understanding the mechanisms of effective early intervention will enable us to identify common or foundational active ingredients for promoting optimal outcomes in children with ASD. PMID:25108609

  14. Radiatively Generating the Higgs Potential and Electroweak Scale via the Seesaw Mechanism.

    Science.gov (United States)

    Brivio, Ilaria; Trott, Michael

    2017-10-06

    The minimal seesaw scenario can radiatively generate the Higgs potential to induce electroweak symmetry breaking while supplying an origin of the Higgs vacuum expectation value from an underlying Majorana scale. If the Higgs potential and (derived) electroweak scale have this origin, the heavy SU(3)×SU(2)×U(1)_{Y} singlet states are expected to reside at m_{N}∼10-500  PeV for couplings |ω|∼10^{-4.5}-10^{-6} between the Majorana sector and the standard model. In this framework, the usual challenge of the electroweak scale hierarchy problem with a classically assumed potential is absent as the electroweak scale is not a fundamental scale. The new challenge is the need to generate or accommodate PeV Majorana mass scales while simultaneously suppressing tree-level contributions to the potential in ultraviolet models.

  15. Assessment of water pollution in the Tronto River (Italy) by applying useful biomarkers in the fish model Carassius auratus.

    Science.gov (United States)

    Palermo, F A; Mosconi, G; Angeletti, M; Polzonetti-Magni, A M

    2008-08-01

    The Tronto River (southern Marche region of central Italy) is located in an area with neighboring industrial activities and is contaminated with domestic and industrial wastewater. Water quality data analyses revealed the presence of a mixture of low levels of heavy metals and organic compounds. The effects of long-term exposure to Tronto River water on juvenile Carassius auratus were evaluated with an integrated approach using xenoestrogens biomarkers, such as vitellogenin (VTG) and ER beta-1 mRNA expression, and stress parameters (i.e., cortisol and glucose in the blood and glycogen in the liver). Treatment with Tronto River water did not induce VTG synthesis in fish and did not affect ER beta-1 mRNA expression. Moreover, cortisol titers found in the plasma of fish exposed to Tronto River water were lower than those found in the control group. Regarding energy parameters, treatment with Tronto River water induced an increase in plasma glucose and a depletion of liver glycogen reserves.The effects of Tronto River water were studied in parallel with those of 4-NP and CdCl(2). The 4-NP at the dose of 22 microg/L induced the synthesis of peripheral vitellogenin and increase of ER beta-1 titers; on the contrary, CdCl2 exposure at the concentration of 22 microg/L did not induce significant changes on plasma VTG and/or hepatic ER beta-1 levels. In addition, no significant changes in plasma cortisol levels in fish exposed to 4-NP or CdCl(2) were found. Fish exposed to CdCl(2) displayed liver glycogen depletion, but no significant increase in plasma glucose was observed. On the contrary, a 30-day exposure to 4-NP induced only a slight decrease of glycogen reserves without any changes in plasma glucose levels. In conclusion, our study demonstrated that long-term exposure of juvenile goldfish to the water of the Tronto River significantly affects both stress and energy parameters. There is evidence that pollutants, present in Tronto River water, were not able to induce

  16. Mechanism

    Directory of Open Access Journals (Sweden)

    Yao Yu

    2010-01-01

    Full Text Available The kinematics analysis method of a novel 3-DOF wind tunnel mechanism based on cable-driven parallel mechanism is provided. Rodrigues' parameters are applied to express the transformation matrix of the wire-driven mechanism in the paper. The analytical forward kinematics model is described as three quadratic equations using three Rodridgues' parameters based on the fundamental theory of parallel mechanism. Elimination method is used to remove two of the variables, so that an eighth-order polynomial with one variable is derived. From the equation, the eight sets of Rodridgues' parameters and corresponding Euler angles for the forward kinematical problem can be obtained. In the end, numerical example of both forward and inverse kinematics is included to demonstrate the presented forward-kinematics solution method. The numerical results show that the method for the position analysis of this mechanism is effective.

  17. A potential biochemical mechanism underlying the influence of sterol deprivation stress on Caenorhabditis elegans longevity

    Science.gov (United States)

    To investigate the biochemical mechanism for sterol-mediated alteration in aging in Caenorhabditis elegans, we established sterol depletion conditions by treating worms with azacoprostane, which reduced mean lifespan of adult C. elegans by 35%. Proteomic analyses of egg proteins from treated and un...

  18. POTENTIAL MECHANISMS RESPONSIBLE FOR CHLOROTRIAZINE-INDUCED ALTERATIONS IN CATECHOLAMINES IN PHEOCHROMOCYTOMA (PC12) CELLS

    Science.gov (United States)

    ABSTRACTPotential Mechanisms Responsible for Chlorotriazine-induced Changes in Catecholamine Metabolism in Pheochromocytoma (PC12) Cells*PARIKSHIT C. DAS1, WILLIAM K. McELROY2 , AND RALPH L. COOPER2+ 1Curriculum in Toxicology, University of North Carolina, Chape...

  19. Effect of potential factors in manufacturing process on mechanical properties of F82H

    Energy Technology Data Exchange (ETDEWEB)

    Sakasegawa, Hideo, E-mail: sakasegawa.hideo@jaea.go.jp [Japan Atomic Energy Agency, Rokkasho, Aomori 039-3212 (Japan); Tanigawa, Hiroyasu [Japan Atomic Energy Agency, Rokkasho, Aomori 039-3212 (Japan); Tanigawa, Hisashi; Hirose, Takanori [Japan Atomic Energy Agency, Naka, Ibaraki 311-0193 (Japan)

    2014-10-15

    Highlights: • Effects of hot forging and cooling method on mechanical properties were studied. • Differences, inhomogeneity, and anisotropy in tensile and Charpy impact properties were observed for plates with a lower hot forging level. • No significant difference was observed in tensile and Charpy impact properties between air cooled and water quenched samples. - Abstract: A DEMO reactor requires over 3500 tons of reduced activation ferritic/martensitic steel. To prepare such a large quantity of the material with appropriate mechanical properties, it is important to study the effect of various factors in the manufacturing process for mass production. In our work, we focused on the effects of hot forging and the cooling method after normalizing, which have not been previously studied. Plates with three different thicknesses were fabricated from slabs with two different hot forging reduction ratios, and the tensile and Charpy impact properties were evaluated for each of these plates. The plates made using a lower hot forging reduction ratio had different tensile properties, and inhomogeneity and anisotropy were observed in the Charpy impact test results. These results indicate that the hot forging operation to which the ingot is initially subjected must be sufficiently high to ensure that the appropriate mechanical properties are achieved. To test the effect of the cooling method, plates cooled in air and those quenched in water after normalizing were prepared, and tensile and Charpy impact tests were performed on these plates. No significant differences were observed indicating that air cooling is sufficient to obtain the appropriate mechanical properties.

  20. Potential Mechanization in the Flue-Cured Tobacco Industry--with Emphasis on Human Resource Adjustment.

    Science.gov (United States)

    McElroy, Robert C.; And Others

    Large numbers of people are still employed in production, marketing, and processing of flue-cured tobacco in eight agricultural subregions in five southeastern states. Mechanization and new technology which is being introduced could result in substantial economic and social problems unless new economic opportunities are developed. However,…

  1. Identifying potential mechanisms enabling acidophily in the ammonia-oxidising archaeon 'Candidatus Nitrosotalea devanaterra'

    NARCIS (Netherlands)

    Lehtovirta-Morely, Laura E.; Sayavedra-Soto, L.; Gallois, Nicolas; Schouten, S.; Stein, L.Y.; Prosser, James I.; Nicol, G.W.

    Ammonia oxidation is the first and rate-limiting step in nitrification and is dominated by two distinct groups of microorganisms in soil: ammonia-oxidizing archaea (AOA) and ammonia-oxidizing bacteria (AOB). AOA are often more abundant than AOB and dominate activity in acid soils. The mechanism of

  2. Deciphering spreading mechanisms in amyotrophic lateral sclerosis: clinical evidence and potential molecular processes.

    Science.gov (United States)

    Pradat, Pierre-François; Kabashi, Edor; Desnuelle, Claude

    2015-10-01

    The aim of this review is to refer to recent arguments supporting the existence of specific propagation mechanisms associated with spreading of neuron injury in amyotrophic lateral sclerosis (ALS). Misfolded ALS-linked protein accumulation can induce aggregation of their native equivalent isoforms through a mechanism analogous to the infectious prion proteins initiation and its propagation. Although ALS is clinically heterogeneous, a shared characteristic is the focal onset and the progressive extension to all body regions. Being viewed until now as just summation of the increased number of affected neurons, dispersion is now rather considered as the result of a seeded self-propagating process. A sequential regional spreading pattern is supported by the distribution of TDP-43 aggregates in ALS autopsy cases. Electrophysiology and advanced neuroimaging methods also recently provided some evidence for propagation of lesions both in the brain and spinal cord, more longitudinal studies being still needed. Lesions are supposed to spread cell-to-cell regionally or through connected neuronal pathway. At the molecular level, the prion-like spreading is an emerging mechanism hypothesis, but other machineries such as those that are in charge of dealing with misfolded proteins and secretion of deleterious peptides may be involved in the propagation of neuron loss. Deciphering the mechanisms underlying spreading of ALS symptoms is of crucial importance to better understand this neurodegenerative disease, build new and appropriate animal models and to define novel therapeutic targets.

  3. The mechanics of the gibbon foot and its potential for elastic energy storage during bipedalism.

    Science.gov (United States)

    Vereecke, Evie E; Aerts, Peter

    2008-12-01

    The mechanics of the modern human foot and its specialization for habitual bipedalism are well understood. The windlass mechanism gives it the required stability for propulsion generation, and flattening of the arch and stretching of the plantar aponeurosis leads to energy saving. What is less well understood is how an essentially flat and mobile foot, as found in protohominins and extant apes, functions during bipedalism. This study evaluates the hypothesis that an energy-saving mechanism, by stretch and recoil of plantar connective tissues, is present in the mobile gibbon foot and provides a two-dimensional analysis of the internal joint mechanics of the foot during spontaneous bipedalism of gibbons using a four-link segment foot model. Available force and pressure data are combined with detailed foot kinematics, recorded with a high-speed camera at 250 Hz, to calculate the external joint moments at the metatarsophalangeal (MP), tarsometatarsal (TM) and talocrural (TC) joints. In addition, instantaneous joint powers are estimated to obtain insight into the propulsion-generating capacities of the internal foot joints. It is found that, next to a wide range of motion at the TC joint, substantial motion is observed at the TM and MP joint, underlining the importance of using a multi-segment foot model in primate gait analyses. More importantly, however, this study shows that although a compliant foot is less mechanically effective for push-off than a ;rigid' arched foot, it can contribute to the generation of propulsion in bipedal locomotion via stretch and recoil of the plantarflexor tendons and plantar ligaments.

  4. Potential mechanisms of cadmium removal from aqueous solution by Canna indica derived biochar

    International Nuclear Information System (INIS)

    Cui, Xiaoqiang; Fang, Siyu; Yao, Yiqiang; Li, Tingqiang; Ni, Qijun; Yang, Xiaoe; He, Zhenli

    2016-01-01

    The objective of this study was to investigate the mechanisms of cadmium (Cd) sorption on biochars produced at different temperature (300–600 °C) and their quantitative contribution. The sorption isotherms and kinetics of Cd 2+ sorption on biochars were determined and fitted to different models. The Cd 2+ sorption data could be well described by a simple Langmuir model, and the pseudo second order kinetic model best fitted the kinetic data. The maximum sorption capacity (Q m ) obtained from the Langmuir model for CIB500 was 188.8 mg g −1 , which was greater than that of biochars produced at other temperature. Precipitation with minerals, ion exchange, complexation with surface oxygen-containing functional groups, and coordination with π electrons were the possible mechanisms of Cd 2+ sorption on the biochars. The contribution of each mechanism varied with the pyrolysis temperature. With increasing pyrolysis temperature, the contribution of surface complexation and metal ion exchange decreased from 24.5% and 43.3% to 0.7% and 4.7%, while the contribution of precipitation and Cd 2+ -π interaction significantly increased from 29.7% and 2.5% to 89.5% and 5.1%, respectively. Overall, the precipitation with minerals and metal ion exchange dominated Cd 2+ sorption on the biochars (accounted for 73.0–94.1%), and precipitation with minerals was the primary mechanism of Cd 2+ sorption on the high-temperature biochars (≥ 500 °C) (accounted for 86.1–89.5%). - Highlights: • Sorption capacity of metal on biochars is affected by pyrolysis temperature. • Biochar derived from Canna indica at 500 °C has a high sorption capacity for Cd 2+ . • Cd 2+ sorption on the biochars fits a pseudo second order and Langmuir model. • Precipitation and ion exchange mechanisms dominated Cd 2+ sorption on the biochars.

  5. Protective role of Nrf2 against mechanical-stretch-induced apoptosis in mouse fibroblasts: a potential therapeutic target of mechanical-trauma-induced stress urinary incontinence.

    Science.gov (United States)

    Li, Qiannan; Li, Bingshu; Liu, Cheng; Wang, Linlin; Tang, Jianming; Hong, Li

    2018-01-10

    We investigated the protective effect and underlying molecular mechanism of nuclear factor-E2-related factor 2 (Nrf2) against mechanical-stretch-induced apoptosis in mouse fibroblasts. Normal cells, Nrf2 silencing cells, and Nrf2 overexpressing cells were respectively divided into two groups-nonintervention and cyclic mechanical strain (CMS)-subjected to CMS of 5333 μ (1.0 Hz for 4 h), six groups in total (control, CMS, shNfe212, shNfe212 + CMS, LV-shNfe212, and LV-shNfe212 + CMS). After treatment, cell apoptosis; cell-cycle distribution; expressions of Nrf2, Bax, Bcl-2, Cyt-C, caspase-3, caspase-9, cleaved-caspase-3, and cleaved-caspase-9; mitochondrial membrane potential (ΔΨm); reactive oxygen species (ROS); and malondialdehyde (MDA) levels were measured. Thirty virgin female C57BL/6 mice were divided into two groups: control (without intervention) and vaginal distension (VD) groups, which underwent VD for 1 h with an 8-mm dilator (0.3 ml saline). Leak-point pressure (LPP) was tested on day 7 after VD; Nrf2 expression, apoptosis, and MDA levels were then measured in urethra and anterior vaginal wall. Mechanical stretch decreased Nrf2 messenger RNA (mRNA) and protein expressions. Overexpression of Nrf2 alleviated mechanical-stretch-induced cell apoptosis; S-phase arrest of cell cycle; up-regulation of Bax, cytochrome C (Cyt-C), ROS, MDA, ratio of cleaved-caspase-3/caspase-3 and cleaved-caspase-9/caspase-9; and exacerbated the decrease of Bcl2 and ΔΨm in L929 cells. On the contrary, silencing of Nrf2 showed opposite effects. Besides, VD reduced LPP levels and Nrf2 expression and increased cell apoptosis and MDA generation in the urethra and anterior vaginal wall. Nrf2 exhibits a protective role against mechanical-stretch -induced apoptosis on mouse fibroblasts, which might indicate a potential therapeutic target of mechanical-trauma-induced stress urinary incontinence (SUI).

  6. A mechanically-induced colon cancer cell population shows increased metastatic potential

    KAUST Repository

    Tang, Xin

    2014-05-29

    Background: Metastasis accounts for the majority of deaths from cancer. Although tumor microenvironment has been shown to have a significant impact on the initiation and/or promotion of metastasis, the mechanism remains elusive. We previously reported that HCT-8 colon cancer cells underwent a phenotypic transition from an adhesive epithelial type (E-cell) to a rounded dissociated type (R-cell) via soft substrate culture, which resembled the initiation of metastasis. The objective of current study was to investigate the molecular and metabolic mechanisms of the E-R transition.Methods: Global gene expressions of HCT-8 E and R cells were measured by RNA Sequencing (RNA-seq); and the results were further confirmed by real-time PCR. Reactive oxygen species (ROS), anoikis resistance, enzyme activity of aldehyde dehydrogenase 3 family, member A1 (ALDH3A1), and in vitro invasion assay were tested on both E and R cells. The deformability of HCT-8 E and R cells was measured by atomic force microscopy (AFM). To study the in vivo invasiveness of two cell types, athymic nude mice were intra-splenically injected with HCT-8 E or R cells and sacrificed after 9 weeks. Incidences of tumor development and metastasis were histologically evaluated and analyzed with Fisher\\'s exact test.Results: Besides HCT-8, E-R transition on soft substrates was also seen in three other cancer cell lines (HCT116, SW480 colon and DU145 prostate cancer). The expression of some genes, such as ALDH3A1, TNS4, CLDN2, and AKR1B10, which are known to play important roles in cancer cell migration, invasion, proliferation and apoptosis, were increased in HCT-8 R cells. R cells also showed higher ALDH3A1 enzyme activity, higher ROS, higher anoikis resistance, and higher softness than E cells. More importantly, in vitro assay and in vivo animal models revealed that HCT-8 R cells were more invasive than E cells.Conclusions: Our comprehensive comparison of HCT-8 E and R cells revealed differences of molecular

  7. The limit passage of space curvature in problems of celestial mechanics with the generalized Kepler and Hooke potentials

    Science.gov (United States)

    Vozmishcheva, Tatiana

    2016-09-01

    The connection between the problems of celestial mechanics: the Kepler problem, the two-center problem and the two body problem in spaces of constant curvature with the generalized Kepler and Hooke potentials is investigated. The limit passage in the two-center and two body problems in the Lobachevsky space and on a sphere is carried out as λto0 (λ is the curvature of the corresponding space) for the two potentials. The potentials and metrics in spaces under study are written in the gnomonic coordinates. It is shown that as the curvature radius tends to infinity, the generalized gravitational and elastic potentials transform to the Kepler and Hooke forms in the Euclidean space.

  8. Clinical evidence and potential mechanisms of Chinese medicines for the treatment of diabetic retinopathy

    Directory of Open Access Journals (Sweden)

    Jian Huo

    2018-03-01

    Full Text Available Diabetic retinopathy is one of the main causes of visual impairment and blindness on a global scale. At present, the limitations of anti-vascular endothelial growth factor agents, steroids, laser photocoagulation, and vitreous surgery have led to a growing awareness of the role of Chinese medicines in the treatment of diabetic retinopathy. This review first describes the ingredients and characteristics of the formulae including Chinese herbal formulaes, Chinese patent drugs and ancient processed drugs and summarizes the application of Chinese medicines and their mechanisms of action in the treatment of diabetic retinopathy. Due to the complexity of Chinese medicines, in-depth mechanisms, side effects of herb, and drug interactions need to be elaborated in future research. Chinese medicines have the potencial to protect the residual eyesight and delay the progression of disease, thereby offering a beneficial, exploitable option in the treatment/prevention of diabetic retinopathy.

  9. Chronic Lowering of Blood Pressure by Carotid Baroreflex Activation: Mechanisms and Potential for Hypertension Therapy

    Science.gov (United States)

    Lohmeier, Thomas E.; Iliescu, Radu

    2011-01-01

    Recent technical advances have renewed interest in device-based therapy for the treatment of drug-resistant hypertension. Findings from recent clinical trials regarding the efficacy of electrical stimulation of the carotid sinus for the treatment of resistant hypertension are reviewed here. The main goal of this article, however, is to summarize the preclinical studies that have provided insight into the mechanisms that account for the chronic blood pressure lowering effects of carotid baroreflex activation. Some of the mechanisms identified were predictable and confirmed by experimentation. Others have been surprising and controversial and resolution will require further investigation. Although feasibility studies have been promising, firm conclusions regarding the value of this device-based therapy for the treatment of resistant hypertension awaits the results of current multicenter trials. PMID:21357283

  10. A Gut Feeling to Cure Diabetes: Potential Mechanisms of Diabetes Remission after Bariatric Surgery

    OpenAIRE

    Cho, Young Min

    2014-01-01

    A cure for type 2 diabetes was once a mere dream but has now become a tangible and achievable goal with the unforeseen success of bariatric surgery in the treatment of both obesity and type 2 diabetes. Popular bariatric procedures such as Roux-en-Y gastric bypass and sleeve gastrectomy exhibit high rates of diabetes remission or marked improvement in glycemic control. However, the mechanism of diabetes remission following these procedures is still elusive and appears to be very complex and en...

  11. Potential Mechanisms for IgG4 Inhibition of Immediate Hypersensitivity Reactions.

    Science.gov (United States)

    James, Louisa K; Till, Stephen J

    2016-03-01

    IgG4 is the least abundant IgG subclass in human serum, representing less than 5% of all IgG. Increases in IgG4 occur following chronic exposure to antigen and are generally associated with states of immune tolerance. In line with this, IgG4 is regarded as an anti-inflammatory antibody with a limited ability to elicit effective immune responses. Furthermore, IgG4 attenuates allergic responses by inhibiting the activity of IgE. The mechanism by which IgG4 inhibits IgE-mediated hypersensitivity has been investigated using a variety of model systems leading to two proposed mechanisms. First by sequestering antigen, IgG4 can function as a blocking antibody, preventing cross-linking of receptor bound IgE. Second IgG4 has been proposed to co-stimulate the inhibitory IgG receptor FcγRIIb, which can negatively regulate FcεRI signaling and in turn inhibit effector cell activation. Recent advances in our understanding of the structural features of human IgG4 have shed light on the unique functional and immunologic properties of IgG4. The aim of this review is to evaluate our current understanding of IgG4 biology and reassess the mechanisms by which IgG4 functions to inhibit IgE-mediated allergic responses.

  12. Mechanical Myocardial Injury and Angiogenesis: An Association with Therapeutic Potential for Advanced Ischemic Coronary Artery Disease.

    Science.gov (United States)

    Slepian, Marvin J.

    2001-08-01

    The healing response of tissue after mechanical injury is a highly evolved complex response that serves as a natural defense mechanism. Tissue wounds typically heal in a temporal sequence of stages. A vital phase of wound healing is the generation of loose reparative tissue that is neovascularized and rich in angiogenic substrates--that of granulation tissue formation. A therapeutic strategy that has emerged for the treatment of patients with advanced atherosclerotic ischemic coronary disease is to therapeutically manipulate the wound healing process and induce injury in the myocardium to stimulate islands of neovascularization. This paper reviews the response of tissue, particularly the myocardium, to various forms of injury. Also discussed is the emerging hypothesis of a threshold of injury (balancing adequate injury to induce neovascularizatioin versus excessive injury resulting in adjacent myocardial damage with contractile dysfunction without additional angiogenic benefit). Initial animal and human studies from our laboratory and that of collaborators, with a new method of injury-induced angiogenesis referred to as mechanical myocardial channeling, are reviewed.

  13. Attentional Mechanisms in Sports via Brain-Electrical Event-Related Potentials

    Science.gov (United States)

    Hack, Johannes; Memmert, Daniel; Rup, Andre

    2009-01-01

    In this study, we examined attention processes in complex, sport-specific decision-making tasks without interdependencies from anticipation. Psychophysiological and performance data recorded from advanced and intermediate level basketball referees were compared. Event-related potentials obtained while judging game situations in foul recognition…

  14. Quantum mechanics of yr and non-yr -symmetric potentials in three ...

    Indian Academy of Sciences (India)

    2016-06-17

    Jun 17, 2016 ... Abstract. With a view of exploring new vistas with regard to the nature of complex eigenspectra of a non-. Hermitian Hamiltonian, the quasi-exact solutions of the Schrödinger equation are investigated for a shifted harmonic potential under the framework of extended complex phase-space approach.

  15. Potential mechanisms of cadmium removal from aqueous solution by Canna indica derived biochar

    Energy Technology Data Exchange (ETDEWEB)

    Cui, Xiaoqiang; Fang, Siyu; Yao, Yiqiang; Li, Tingqiang [Ministry of Education Key Laboratory of Environmental Remediation and Ecological Health, College of Environmental and Resource Sciences, Zhejiang University, Hangzhou 310058 (China); Ni, Qijun [The 702 Research Institute of China Shipbuilding Industry Corporation, Wuxi 214082 (China); Yang, Xiaoe, E-mail: xyang@zju.edu.cn [Ministry of Education Key Laboratory of Environmental Remediation and Ecological Health, College of Environmental and Resource Sciences, Zhejiang University, Hangzhou 310058 (China); He, Zhenli [Indian River Research and Education Center, Institute of Food and Agricultural Sciences, University of Florida, Fort Pierce, FL 34951 (United States)

    2016-08-15

    The objective of this study was to investigate the mechanisms of cadmium (Cd) sorption on biochars produced at different temperature (300–600 °C) and their quantitative contribution. The sorption isotherms and kinetics of Cd{sup 2+} sorption on biochars were determined and fitted to different models. The Cd{sup 2+} sorption data could be well described by a simple Langmuir model, and the pseudo second order kinetic model best fitted the kinetic data. The maximum sorption capacity (Q{sub m}) obtained from the Langmuir model for CIB500 was 188.8 mg g{sup −1}, which was greater than that of biochars produced at other temperature. Precipitation with minerals, ion exchange, complexation with surface oxygen-containing functional groups, and coordination with π electrons were the possible mechanisms of Cd{sup 2+} sorption on the biochars. The contribution of each mechanism varied with the pyrolysis temperature. With increasing pyrolysis temperature, the contribution of surface complexation and metal ion exchange decreased from 24.5% and 43.3% to 0.7% and 4.7%, while the contribution of precipitation and Cd{sup 2+}-π interaction significantly increased from 29.7% and 2.5% to 89.5% and 5.1%, respectively. Overall, the precipitation with minerals and metal ion exchange dominated Cd{sup 2+} sorption on the biochars (accounted for 73.0–94.1%), and precipitation with minerals was the primary mechanism of Cd{sup 2+} sorption on the high-temperature biochars (≥ 500 °C) (accounted for 86.1–89.5%). - Highlights: • Sorption capacity of metal on biochars is affected by pyrolysis temperature. • Biochar derived from Canna indica at 500 °C has a high sorption capacity for Cd{sup 2+}. • Cd{sup 2+} sorption on the biochars fits a pseudo second order and Langmuir model. • Precipitation and ion exchange mechanisms dominated Cd{sup 2+} sorption on the biochars.

  16. Advection of Potential Temperature in the Atmosphere of Irradiated Exoplanets: A Robust Mechanism to Explain Radius Inflation

    Energy Technology Data Exchange (ETDEWEB)

    Tremblin, P. [Maison de la Simulation, CEA-CNRS-INRIA-UPS-UVSQ, USR 3441, CEA Paris-Saclay, F-91191 Gif-Sur-Yvette (France); Chabrier, G.; Mayne, N. J.; Baraffe, I.; Debras, F.; Drummond, B.; Manners, J. [Astrophysics Group, University of Exeter, EX4 4QL Exeter (United Kingdom); Amundsen, D. S. [Department of Applied Physics and Applied Mathematics, Columbia University, New York, NY 10025 (United States); Fromang, S., E-mail: pascal.tremblin@cea.fr [Laboratoire AIM, CEA/DSM-CNRS-Université Paris 7, Irfu/Service d’Astrophysique, CEA Paris-Saclay, F-91191 Gif-sur-Yvette (France)

    2017-05-20

    The anomalously large radii of strongly irradiated exoplanets have remained a major puzzle in astronomy. Based on a two-dimensional steady-state atmospheric circulation model, the validity of which is assessed by comparison to three-dimensional calculations, we reveal a new mechanism, namely the advection of the potential temperature due to mass and longitudinal momentum conservation, a process occurring in the Earth’s atmosphere or oceans. In the deep atmosphere, the vanishing heating flux forces the atmospheric structure to converge to a hotter adiabat than the one obtained with 1D calculations, implying a larger radius for the planet. Not only do the calculations reproduce the observed radius of HD 209458b, but also reproduce the observed correlation between radius inflation and irradiation for transiting planets. Vertical advection of potential temperature induced by non-uniform atmospheric heating thus provides a robust mechanism to explain the inflated radii of irradiated hot Jupiters.

  17. Advection of Potential Temperature in the Atmosphere of Irradiated Exoplanets: A Robust Mechanism to Explain Radius Inflation

    Science.gov (United States)

    Tremblin, P.; Chabrier, G.; Mayne, N. J.; Amundsen, D. S.; Baraffe, I.; Debras, F.; Drummond, B.; Manners, J.; Fromang, S.

    2017-01-01

    The anomalously large radii of strongly irradiated exoplanets have remained a major puzzle in astronomy. Based on a two-dimensional steady-state atmospheric circulation model, the validity of which is assessed by comparison to three-dimensional calculations, we reveal a new mechanism, namely the advection of the potential temperature due to mass and longitudinal momentum conservation, a process occurring in the Earth's atmosphere or oceans. In the deep atmosphere, the vanishing heating flux forces the atmospheric structure to converge to a hotter adiabat than the one obtained with 1D calculations, implying a larger radius for the planet. Not only do the calculations reproduce the observed radius of HD 209458b, but also reproduce the observed correlation between radius inflation and irradiation for transiting planets. Vertical advection of potential temperature induced by non-uniform atmospheric heating thus provides a robust mechanism to explain the inflated radii of irradiated hot Jupiters.

  18. Potential of magnetic nanofiber scaffolds with mechanical and biological properties applicable for bone regeneration.

    Science.gov (United States)

    Singh, Rajendra K; Patel, Kapil D; Lee, Jae Ho; Lee, Eun-Jung; Kim, Joong-Hyun; Kim, Tae-Hyun; Kim, Hae-Won

    2014-01-01

    Magnetic nanofibrous scaffolds of poly(caprolactone) (PCL) incorporating magnetic nanoparticles (MNP) were produced, and their effects on physico-chemical, mechanical and biological properties were extensively addressed to find efficacy for bone regeneration purpose. MNPs 12 nm in diameter were citrated and evenly distributed in PCL solutions up to 20% and then were electrospun into nonwoven nanofibrous webs. Incorporation of MNPs greatly improved the hydrophilicity of the nanofibers. Tensile mechanical properties of the nanofibers (tensile strength, yield strength, elastic modulus and elongation) were significantly enhanced with the addition of MNPs up to 15%. In particular, the tensile strength increase was as high as ∼25 MPa at 15% MNPs vs. ∼10 MPa in pure PCL. PCL-MNP nanofibers exhibited magnetic behaviors, with a high saturation point and hysteresis loop area, which increased gradually with MNP content. The incorporation of MNPs substantially increased the degradation of the nanofibers, with a weight loss of ∼20% in pure PCL, ∼45% in 10% MNPs and ∼60% in 20% MNPs. Apatite forming ability of the nanofibers tested in vitro in simulated body fluid confirmed the substantial improvement gained by the addition of MNPs. Osteoblastic cells favored the MNPs-incorporated nanofibers with significantly improved initial cell adhesion and subsequent penetration through the nanofibers, compared to pure PCL. Alkaline phosphatase activity and expression of genes associated with bone (collagen I, osteopontin and bone sialoprotein) were significantly up-regulated in cells cultured on PCL-MNP nanofibers than those on pure PCL. PCL-MNP nanofibers subcutaneously implanted in rats exhibited minimal adverse tissue reactions, while inducing substantial neoblood vessel formation, which however, greatly limited in pure PCL. In vivo study in radial segmental defects also signified the bone regeneration ability of the PCL-MNP nanofibrous scaffolds. The magnetic, bone

  19. Mechanisms Fostering Social Entrepreneurship as Potential Instruments for Economic Development: The Eastern Partnership Perspective

    Directory of Open Access Journals (Sweden)

    Plotnieks Dāvis

    2014-10-01

    Full Text Available With its plan to assign 600 million euros through the European Neighbourhood Instrument for Eastern Partnership countries, the European Union intended to increase the efficiency of institutions, attenuate social problems, and create an environment that fosters economic growth and human well-being in Armenia, Azerbaijan, Belarus, Georgia, Moldova, and Ukraine. A few scholars have criticized the amount of funding and planned initiatives of the European Neighbourhood Instrument as insufficient and suggested that in order to foster cooperation and support reforms in its Eastern Partnership countries, more action should be taken. In times when European Commission budget is under constraints of consolidation and increase of aid for supporting European Neighbourhood countries is hardly possible, alternative solutions for tempering social problems need to be assessed. Various scientists, philanthropists and entrepreneurs see social entrepreneurship as a tool for solving social problems in a sustainable way where business thinking is being combined with non-profit philosophy. Contrary to government support and intervention for solving social problems, social entrepreneurship is already being used as tool that initially addresses joint needs--solve social problems and create revenue that provides much needed income for sustainable business initiatives. This paper analyzes the concept of social entrepreneurship, examples where social entrepreneurship is solving social problems, and mechanisms that can foster these phenomena. The aim of this paper is to examine different mechanisms of how governments can foster the creation and development of social entrepreneurship. Unique survey data derived from a project examining social entrepreneurship in Europe is used. It is concluded that by adopting mechanisms proven in various developed countries, the Eastern Partnership countries can stimulate social entrepreneurship, thus attenuating social problems and

  20. MECHANISMS IN ENDOCRINOLOGY: Diabetic cardiomyopathy: pathophysiology and potential metabolic interventions state of the art review.

    Science.gov (United States)

    Levelt, Eylem; Gulsin, Gaurav; Neubauer, Stefan; McCann, Gerry P

    2018-04-01

    Heart failure is a major cause of morbidity and mortality in type 2 diabetes. Type 2 diabetes contributes to the development of heart failure through a variety of mechanisms, including disease-specific myocardial structural, functional and metabolic changes. This review will focus on the contemporary contributions of state of the art non-invasive technologies to our understanding of diabetic cardiomyopathy, including data on cardiac disease phenotype, cardiac energy metabolism and energetic deficiency, ectopic and visceral adiposity, diabetic liver disease, metabolic modulation strategies and cardiovascular outcomes with new classes of glucose-lowering therapies. © 2018 The authors.

  1. Review of numerical methods for simulation of mechanical heart valves and the potential for blood clotting.

    Science.gov (United States)

    Zakaria, Mohamad Shukri; Ismail, Farzad; Tamagawa, Masaaki; Aziz, Ahmad Fazli Abdul; Wiriadidjaja, Surjatin; Basri, Adi Azrif; Ahmad, Kamarul Arifin

    2017-09-01

    Even though the mechanical heart valve (MHV) has been used routinely in clinical practice for over 60 years, the occurrence of serious complications such as blood clotting remains to be elucidated. This paper reviews the progress that has been made over the years in terms of numerical simulation method and the contribution of abnormal flow toward blood clotting from MHVs in the aortic position. It is believed that this review would likely be of interest to some readers in various disciplines, such as engineers, scientists, mathematicians and surgeons, to understand the phenomenon of blood clotting in MHVs through computational fluid dynamics.

  2. Deep Potential Molecular Dynamics: A Scalable Model with the Accuracy of Quantum Mechanics

    Science.gov (United States)

    Zhang, Linfeng; Han, Jiequn; Wang, Han; Car, Roberto; E, Weinan

    2018-04-01

    We introduce a scheme for molecular simulations, the deep potential molecular dynamics (DPMD) method, based on a many-body potential and interatomic forces generated by a carefully crafted deep neural network trained with ab initio data. The neural network model preserves all the natural symmetries in the problem. It is first-principles based in the sense that there are no ad hoc components aside from the network model. We show that the proposed scheme provides an efficient and accurate protocol in a variety of systems, including bulk materials and molecules. In all these cases, DPMD gives results that are essentially indistinguishable from the original data, at a cost that scales linearly with system size.

  3. Quantum mechanics of yr and non-yr -symmetric potentials in three ...

    Indian Academy of Sciences (India)

    2016-06-17

    Jun 17, 2016 ... iH2(x1,p1,x2,p2,x3,p3) leads to several interesting features regarding the integrability of the associated real system. In the quantum context, on the other hand, analyticity of H(x,y,z,px,py,pz) gets trans- lated into that of the complex potential. A complex. Hamiltonian is no longer Hermitian and ordinarily does.

  4. Pro-oxidant iron in exhaled breath condensate: a potential excretory mechanism.

    Science.gov (United States)

    Mumby, S; Chung, K F; McCreanor, J E; Moloney, E D; Griffiths, M J D; Quinlan, G J

    2011-09-01

    Pro-oxidant iron provides a potential measure of iron-catalysed oxidative stress in biological fluids. This study aimed, to investigate if the Bleomycin technique for measurement of pro-oxidant iron in biological fluids could be utilised for determinations in exhaled breath condensate (EBC). Secondly, to measure levels of pro-oxidant iron in EBC from asthmatics after exposure to polluting city environments. Retrospective analysis of samples of EBC and bronchoalveolar lavage fluid (BALF). Pro-oxidant iron levels were determined by the Bleomycin method. Transferrin levels were determined by radial diffusion immunoassay and lactoferrin by ELISA. Patients undergoing surgery necessitating cardiopulmonary bypass, normal healthy controls, "healthy" smokers, and asthmatics (mild and moderate). Pro-oxidant iron was significantly decreased (ppro-oxidant iron in EBC were significantly (ppro-oxidant iron content post exposure to city environments (ppro-oxidant iron detectable in EBC and paired BALF from patients undergoing cardiopulmonary bypass (pre and post surgery) suggest a potential for EBC determinations. Significantly elevated levels in EBC from smokers relative to control subjects provide further support for this technique. In asthma disease severity and environmental exposure influenced levels of pro-oxidant iron measured in EBC indicating a potential for enhanced iron-catalysed oxidative stress. Copyright © 2011 Elsevier Ltd. All rights reserved.

  5. Trypanosoma cruzi induces trophoblast differentiation: a potential local antiparasitic mechanism of the human placenta?

    Science.gov (United States)

    Liempi, A; Castillo, C; Duaso, J; Droguett, D; Sandoval, A; Barahona, K; Hernández, A; Galanti, N; Maya, J D; Kemmerling, U

    2014-12-01

    The congenital transmission of Trypanosoma cruzi (T. cruzi) is responsible for one-third of new Chagas disease cases each year. During congenital transmission, the parasite breaks down the placental barrier formed by the trophoblast, basal laminae and villous stroma. The observation that only 5% of infected mothers transmit the parasite to the fetus implies that the placenta may impair parasite transmission. The trophoblast undergoes continuous epithelial turnover, which is considered part of innate immunity. Therefore, we propose that T. cruzi induces differentiation in the trophoblast as part of a local antiparasitic mechanism of the placenta. We analyzed β-human chorionic gonadotropin (β-hCG) and syncytin protein expression in HPCVE and BeWo cells using immunofluorescence and western blotting. Additionally, β-hCG secretion into the culture medium was measured by ELISA. We assessed the differentiation of trophoblastic cells in BeWo cells using the two-color fusion assay and by determining desmoplakin re-distribution. T. cruzi trypomastigotes induce β-hCG secretion and protein expression as well as syncytin protein expression in HPCVE and BeWo cells. Additionally, the parasite induces the trophoblast fusion of BeWo cells. T. cruzi induces differentiation of the trophoblast, which may contribute to increase the trophoblast turnover. The turnover could be a component of local antiparasitic mechanisms in the human placenta. Copyright © 2014 Elsevier Ltd. All rights reserved.

  6. Potential of different mechanical and thermal treatments to control off-flavour generation in broccoli puree.

    Science.gov (United States)

    Koutidou, Maria; Grauwet, Tara; Van Loey, Ann; Acharya, Parag

    2017-02-15

    The aim of this study was scientifically investigate the impact of the sequence of different thermo-mechanical treatments on the volatile profile of differently processed broccoli puree, and to investigate if any relationship persists between detected off-flavour changes and microstructural changes as a function of selected process conditions. Comparison of the headspace GC-MS fingerprinting of the differently processed broccoli purees revealed that an adequate combination of processing steps allows to reduce the level of off-flavour volatiles. Moreover, applying mechanical processing before or after the thermal processing at 90°C determines the pattern of broccoli tissue disruption, resulting into different microstructures and various enzymatic reactions inducing volatile generation. These results may aid the identification of optimal process conditions generating a reduced level of off-flavour in processed broccoli. In this way, broccoli can be incorporated as a food ingredient into mixed food products with limited implications on sensorial consumer acceptance. Copyright © 2016 Elsevier Ltd. All rights reserved.

  7. New Insights on plant salt tolerance mechanisms and their potential use for breeding

    Directory of Open Access Journals (Sweden)

    Moez HANIN

    2016-11-01

    Full Text Available Soil salinization is a major threat to agriculture in arid and semi-arid regions, where water scarcity and inadequate drainage of irrigated lands severely reduce crop yield. Salt accumulation inhibits plant growth and reduces the ability to uptake water and nutrients, leading to osmotic or water-deficit stress. Salt is also causing injury of the young photosynthetic leaves and acceleration of their senescence, as the Na+ cation is toxic when accumulating in cell cytosol resulting in ionic imbalance and toxicity of transpiring leaves. To cope with salt stress, plants have evolved mainly two types of tolerance mechanisms based on either limiting the entry of salt by the roots, or controlling its concentration and distribution. Understanding the overall control of Na+ accumulation and functional studies of genes involved in transport processes, will provide a new opportunity to improve the salinity tolerance of plants relevant to food security in arid regions. A better understanding of these tolerance mechanisms can be used to breed crops with improved yield performance under salinity stress. Moreover, associations of cultures with nitrogen-fixing bactéria and arbuscular mycorrhizal fungi could serve as an alternative and sustainable strategy to increase crop yields in salt affected fields.

  8. Potential psychological & neural mechanisms in binge eating disorder: Implications for treatment.

    Science.gov (United States)

    Kober, Hedy; Boswell, Rebecca G

    2018-03-01

    Binge Eating Disorder (BED) is a newly-established eating disorder diagnosis in the 5th edition of the Diagnostic and Statistical Manual of Mental Disorders (DSM-5). Although systematic research on BED is in its infancy and many studies feature small samples, several observations emerge. First, we review diagnostic, developmental, and socio-demographic features of BED. Next, although BED and obesity are linked and frequently co-occur, we review data suggesting that BED is a distinct phenotype. Importantly, we take a mechanism-focused approach and propose four psychological processes with neurobiological bases that may uniquely differentiate BED from obesity: emotion reactivity, food-cue reactivity, food craving, and cognitive control. Further, we propose that interactions between impairments in cognitive control and increased emotional reactivity, food-cue reactivity, and craving may underlie emotion dysregulation and promote binge eating. Consistently, neuroimaging studies point towards neural alterations in the response to rewards and to food specifically, and suggest preliminary links between impaired cognitive-control-related neural activity and binge eating. However, additional systematic work is required in this area. We conclude with a detailed review of treatment approaches to BED; specifically, we suggest that psychological and pharmacological treatments that target core mechanisms - including cognitive control and emotion/craving dysregulation - may be particularly effective. Copyright © 2018 Elsevier Ltd. All rights reserved.

  9. Astrocytes are involved in trigeminal dynamic mechanical allodynia: potential role of D-serine.

    Science.gov (United States)

    Dieb, W; Hafidi, A

    2013-09-01

    Trigeminal neuropathic pain affects millions of people worldwide. Despite decades of study on the neuronal processing of pain, mechanisms underlying enhanced pain states after injury remain unclear. N-methyl-D-aspartate (NMDA) receptor-dependent changes play a critical role in triggering central sensitization in neuropathic pain. These receptors are regulated at the glycine site through a mandatory endogenous co-agonist D-serine, which is synthesized by astrocytes. Therefore, the present study was carried out to determine whether astrocytes are involved, through D-serine secretion, in dynamic mechanical allodynia (DMA) obtained after chronic constriction of the infraorbital nerve (CCI-IoN) in rats. Two weeks after CCI-IoN, an important reaction of astrocytes was present in the medullary dorsal horn (MDH), as revealed by an up-regulation of glial fibrillary acidic protein (GFAP) in allodynic rats. In parallel, an increase in D-serine synthesis, which co-localized with its synthesis enzyme serine racemase, was strictly observed in astrocytes. Blocking astrocyte metabolism by intracisternal delivery of fluorocitrate alleviated DMA. Furthermore, the administration of D-amino-acid oxidase (DAAO), a D-serine-degrading enzyme, or that of L-serine O-sulfate (LSOS), a serine racemase inhibitor, significantly decreased pain behavior in allodynic rats. These results demonstrate that astrocytes are involved in the modulation of orofacial post-traumatic neuropathic pain via the release of the gliotransmitter D-serine.

  10. Chemical changes and shelf life of surimi of Carassius auratus (Carassius carassius gibelio during storage at super chilling and freezing temperatures

    Directory of Open Access Journals (Sweden)

    M. Afsar Sangari

    2017-07-01

    Full Text Available Production of Surimi from low value fish is a method recommended to increase fish consumption nowadays. In this study, Carassius auratus gibelio was used to produce surimi. Experimental treatments were surimi stored at freezing temperature (-18˚C (group 1 and surimi maintained at super chilling temperature (-3˚C (group 2. The experiment lasted 60 days and approximate composition (moisture, protein, fat, ash and pH, chemical spoilage were examined and oxidation tests including total base volatile nitrogen (TVB-N and Tiubarbutic acid (TBA were carried out periodically. According to the statistical values of fat, pH, TVB-N and TBA were significantly higher in treatment 2 in comparison to treatment 1 during the maintenance period (p

  11. Laboratory evaluation of different formulations of Stress Coat® for slime production in goldfish (Carassius auratus and koi (Cyprinus carpio

    Directory of Open Access Journals (Sweden)

    Raghunath B. Shivappa

    2017-09-01

    Full Text Available A study was carried out to assess the effect of Stress Coat® on slime production in goldfish (Carassius auratus and koi (Cyprinus carpio. The study also investigated histological changes that might be associated with slime producing cells, and wound healing in koi. Several formulations of Stress Coat® were investigated and the results showed that polyvinylpyrrolidone (PVP, also known as povidone, an ingredient of Stress Coat®, when used alone, showed significantly higher slime production in goldfish than salt and Stress Coat® without PVP after 25 h. The results also showed that koi treated with compounds containing PVP showed better wound healing than those not exposed to PVP. Histology results showed no difference between compounds tested with regards to density and number of slime producing cells.

  12. Genome sequencing and annotation of Aeromonas veronii strain Ae52, a multidrug-resistant isolate from septicaemic gold fish (Carassius auratus in Sri Lanka

    Directory of Open Access Journals (Sweden)

    S.S.S. De S. Jagoda

    2017-03-01

    Full Text Available Here we report the draft genome sequence and annotation of A. veronii strain Ae52 isolated from the kidney of a morbund, septicaemic gold fish (Carassius auratus in Sri Lanka. This clinical isolate showed resistance to multiple antimicrobials; amoxicillin, neomycin, trimethoprim-sulphonamide, chloramphenicol, tetracycline, enrofloxacin, erythromycin and nitrofurantoin. The size of the draft genome is 4.56 Mbp with 58.66% of G + C content consisting 4328 coding sequences. It harbors a repertoire of putative antibiotic resistant determinants that explains the genetic basis of its resistance to various classes of antibiotics. The genome sequence has been deposited in DDBJ/EMBL/GenBank under the accession numbers BDGY01000001-BDGY01000080.

  13. Endocrine disrupting effects of waterborne fluoxetine exposure on the reproductive axis of female goldfish, Carassius auratus.

    Science.gov (United States)

    Mennigen, Jan A; Zamora, Jacob M; Chang, John P; Trudeau, Vance L

    2017-11-01

    Evidence suggests that pharmaceuticals and personal care products reach urban watersheds, bioconcentrate in fish, and potentially disrupt physiological homeostasis. These impairments often affect hormone functions. Selective serotonin reuptake inhibitors (SRRIs) are increasingly studied with regards to their endocrine disrupting effects on teleost physiological processes, including reproduction. To examine whether FLX effects on the endocrine regulation of reproductive physiology in goldfish are sex-specific, we exposed sexually recrudescent female goldfish to two waterborne concentrations of FLX (0.54μg/L and 54μg/L) using an experimental design previously used for sexually mature male goldfish. To evaluate possible endocrine disrupting effects, we quantified the gonadosomatic index, circulating hormone concentrations (luteinizing hormone, LH; growth hormone, GH; 17-β estradiol, E 2 ; and testosterone, T), and the expression of isotocin and vasotocin in the telencephalon, gonadotropin subunits and GH in the pituitary, and gonadotropin receptors, GH receptors, and aromatase in the ovary. Female goldfish exposed to 0.54μg/L FLX exhibited a significant decrease in circulating E 2 , and conversely, a significant increase in circulating LH and ovarian aromatase mRNA levels, suggesting disruption of E 2 -mediated feedback on LH release. These results, when compared with those previously observed in males, reveal that waterborne exposure to environmentally relevant levels of FLX sex-specifically disrupts the reproductive endocrine axis in goldfish, characterized by a decrease in E 2 in females, and conversely, estrogen-like effects in males. These data emphasize the importance of studying the effect of endocrine disrupting chemicals on both sexes. Copyright © 2017 Elsevier Inc. All rights reserved.

  14. Mechanics

    CERN Document Server

    Hartog, J P Den

    1961-01-01

    First published over 40 years ago, this work has achieved the status of a classic among introductory texts on mechanics. Den Hartog is known for his lively, discursive and often witty presentations of all the fundamental material of both statics and dynamics (and considerable more advanced material) in new, original ways that provide students with insights into mechanical relationships that other books do not always succeed in conveying. On the other hand, the work is so replete with engineering applications and actual design problems that it is as valuable as a reference to the practicing e

  15. Phosphorus in Hermatypic Coral Skeleton: Incorporation Mechanisms and a Potential Seawater Phosphate Proxy

    Science.gov (United States)

    Lavigne, M. G.; Sherrell, R. M.; Linsley, B. K.; Desenfant, F.

    2006-12-01

    Records of surface water nutrient availability with sub-seasonal resolution would provide crucial evidence in understanding the effects of annual to centennial scale climate variability on oceanic primary production. A direct coral proxy for seawater phosphate would complement low resolution records from established but quantitatively uncertain indirect proxies such as planktonic foraminiferal Cd/Ca. Very recently, Montagna et al. (2006) suggested that LA-ICP-MS measurements of P/Ca in deep sea corals could be used to reconstruct deep water phosphate, although the unknown phosphorus incorporation mechanism adds uncertainty to this emerging proxy.1 Our group is investigating the chemical form and incorporation mechanism for phosphorus in the hermatypic corals Montastrea faveolata (Martinique, Caribbean) and Porites lutea (Rarotonga, South Pacific) using laser ablation and solution phase ICP-MS techniques. We have well calibrated analyses of cleaned and uncleaned micro-drilled samples for a number of trace elements including P by solution phase HR-ICP-MS in Caribbean Montastrea coral. We have also analyzed the Rarotonga Porites coral by LA-ICP-MS resulting in high resolution (~ bi-weekly) phosphorus data over ~ 2.5 years. Phosphorus was resistant to rigorous solution cleaning of the drilled Martinique coral samples. This suggests incorporation largely in inorganic lattice-bound sites rather than as residual organic P or in association with Fe- Mn oxides. High skeletal P/Ca values are found just under the growing surface in the Martinique coral, decreasing exponentially within several millimeters, suggesting that organic P is remineralized quickly, leaving the residual ~constant signal. Both of these corals from the upper 20m had lower P/Ca than deep sea corals (100 - 1200 μmol/mol)1, and the mean P/Ca in Rarotonga Porites (~46 μmol/mol) is higher than in the Martinique Montastrea (18 μmol/mol). Both observations are consistent with the increase in PO4 with depth

  16. Metal accumulation and antioxidant defenses in the freshwater fish Carassius auratus in response to single and combined exposure to cadmium and hydroxylated multi-walled carbon nanotubes

    Energy Technology Data Exchange (ETDEWEB)

    Qu, Ruijuan; Wang, Xinghao; Wang, Zunyao, E-mail: wangzun315cn@163.com; Wei, Zhongbo; Wang, Liansheng

    2014-06-30

    Highlights: • Cd and OH-MWCNTs have a synergistic effect on Carassius auratus. • OH-MWCNTs significantly increased Cd accumulation in liver after 12 d exposure. • Co-exposure to Cd and OH-MWCNTs evoked severe hepatic oxidative stress. - Abstract: The effects of cadmium, hydroxylated multi-walled carbon nanotubes, and their mixture on metal accumulation and antioxidant defenses were studied using the goldfish Carassius auratus as the test organism. The fish were exposed to 0.1 mg/L Cd, 0.5 mg/L OH-MWCNTs, or 0.1 mg/L Cd + 0.5 mg/L OH-MWCNTs for 3 and 12 days. Then, the Cd concentration was determined in the gill, liver and muscle. Moreover, hepatic antioxidant enzyme activity (superoxide dismutase, catalase and glutathione peroxidase), glutathione level and malondialdehyde content were also measured. A continuous accumulation of Cd was observed throughout the experimental period. Cd accumulation in tissues occurred in the following order: gill > liver > muscle at 3 days and liver > gill > muscle at 12 days. The concentrations of Cd in the livers of fish exposed to the combination of Cd + OH-MWCNTs were significantly higher than those in fish exposed to either single chemical after 12 d of exposure. Meanwhile, the mixture evoked severe oxidative stress in the exposed fish, as indicated by significant inhibition of SOD, CAT and GPx activity, a remarkable decrease in GSH level, and simultaneous elevation of MDA content. These results suggested that the effect of the combined factors on metal accumulation and oxidative stress biomarkers was more obvious than that of single factors at longer exposure durations.

  17. Parasitological and histological analysis of a new species of the genus Thalohanellus and description of a myxozoan parasite (Myxosporea: Bivalvulida from cultured ornamental goldfish, Carassius auratus L.

    Directory of Open Access Journals (Sweden)

    Mandira Saha

    2017-11-01

    Full Text Available An ornamental fish parasitological survey of West Bengal, India during the year 2014–16 revealed that goldfish, Carassius auratus, was the most susceptible species for myxozoan infestation. This communication revealed the presence of two myxosporean species belonging to the genera Myxobolus and Thelohanellus. Although myxozoan infestation has been determined by isolating small to large, spherical to ellipsoidal plasmodia up to 0.5–2.5 mm were filled with disporic pansporoblasts and mature spores. M. ichkeulensis and one new species T. dipaki n. sp. have been isolated infecting the ornamental goldfish (Carassius auratus for the first time in India. In the present study, new host, and new locality for M. ichkeulensis have been reported. The description of M. ichkeulensis is being considered as a first report from India. Spore of T. dipaki n. sp. measures uniquely 13.99 ± 0.60 × 9.82 ± 0.60 μm in size, having a one globular pyriform polar capsule measuring 7.45 ± 0.62 × 5.91 ± 0.39 μm. The severity of newly isolated myxozoan infestation has also been assessed by the histopathological changes of fins of the hostfish. A combination of light and scanning electron microscopic observation along with its severity of infestation, comparison of same and closely related species has been incorporated to identify the new species. The paper deals with the diversity, distribution and taxonomic descriptions of new and known myxozoan species along with new host, locality records and incidence of infestation.

  18. Evaluation of potential sources and transport mechanisms of fecal indicator bacteria to beach water, Murphy Park Beach, Door County, Wisconsin

    Science.gov (United States)

    Juckem, Paul F.; Corsi, Steven R.; McDermott, Colleen; Kleinheinz, Gregory; Fogarty, Lisa R.; Haack, Sheridan K.; Johnson, Heather E.

    2013-01-01

    Fecal Indicator Bacteria (FIB) concentrations in beach water have been used for many years as a criterion for closing beaches due to potential health concerns. Yet, current understanding of sources and transport mechanisms that drive FIB occurrence remains insufficient for accurate prediction of closures at many beaches. Murphy Park Beach, a relatively pristine beach on Green Bay in Door County, Wis., was selected for a study to evaluate FIB sources and transport mechanisms. Although the relatively pristine nature of the beach yielded no detection of pathogenic bacterial genes and relatively low FIB concentrations during the study period compared with other Great Lakes Beaches, its selection limited the number of confounding FIB sources and associated transport mechanisms. The primary sources of FIB appear to be internal to the beach rather than external sources such as rivers, storm sewer outfalls, and industrial discharges. Three potential FIB sources were identified: sand, swash-zone groundwater, and Cladophora mats. Modest correlations between FIB concentrations in these potential source reservoirs and FIB concentrations at the beach from the same day illustrate the importance of understanding transport mechanisms between FIB sources and the water column. One likely mechanism for transport and dispersion of FIB from sand and Cladophora sources appears to be agitation of Cladophora mats and erosion of beach sand due to storm activity, as inferred from storm indicators including turbidity, wave height, current speed, wind speed, sky visibility, 24-hour precipitation, and suspended particulate concentration. FIB concentrations in beach water had a statistically significant relation (p-value ‹0.05) with the magnitude of these storm indicators. In addition, transport of FIB in swash-zone groundwater into beach water appears to be driven by groundwater recharge associated with multiday precipitation and corresponding increased swash-zone groundwater discharge at

  19. Ants in a hospital environment and their potential as mechanical bacterial vectors

    Directory of Open Access Journals (Sweden)

    Wanda Ramos dos Santos Lima

    2013-09-01

    Full Text Available Introduction We studied the richness and abundance of ant species, their bacteria and the bacteria isolated from patient clinical samples. Methods Ants were collected with baited traps at 64 sites in a public hospital in São Luis, State of Maranhão, Brazil. Results In total, 1,659 ants from 14 species were captured. The most frequent species were Crematogaster victima, Solenopsis saevissima, Tapinoma melanocephalum, Camponotus vittatus and Paratrechina fulva. Forty-one species of bacteria were isolated from the ants and 18 from patients. Conclusions Ants are potential vehicles for pathogenic and opportunistic bacteria, and they can represent a risk factor in nosocomial infections.

  20. Ants in a hospital environment and their potential as mechanical bacterial vectors.

    Science.gov (United States)

    Lima, Wanda Ramos dos Santos; Marques, Sirlei Garcia; Rodrigues, Fernanda Souto; Rebêlo, José Manuel Macário

    2013-01-01

    We studied the richness and abundance of ant species, their bacteria and the bacteria isolated from patient clinical samples. Ants were collected with baited traps at 64 sites in a public hospital in São Luis, State of Maranhão, Brazil. In total, 1,659 ants from 14 species were captured. The most frequent species were Crematogaster victima, Solenopsis saevissima, Tapinoma melanocephalum, Camponotus vittatus and Paratrechina fulva. Forty-one species of bacteria were isolated from the ants and 18 from patients. Ants are potential vehicles for pathogenic and opportunistic bacteria, and they can represent a risk factor in nosocomial infections.

  1. The Cardioprotective Effects of Hydrogen Sulfide in Heart Diseases: From Molecular Mechanisms to Therapeutic Potential

    OpenAIRE

    Yaqi Shen; Zhuqing Shen; Shanshan Luo; Wei Guo; Yi Zhun Zhu

    2015-01-01

    Hydrogen sulfide (H2S) is now recognized as a third gaseous mediator along with nitric oxide (NO) and carbon monoxide (CO), though it was originally considered as a malodorous and toxic gas. H2S is produced endogenously from cysteine by three enzymes in mammalian tissues. An increasing body of evidence suggests the involvement of H2S in different physiological and pathological processes. Recent studies have shown that H2S has the potential to protect the heart against myocardial infarction, a...

  2. Quantum mechanics of lattice gas automata: One-particle plane waves and potentials

    International Nuclear Information System (INIS)

    Meyer, D.A.

    1997-01-01

    Classical lattice gas automata effectively simulate physical processes, such as diffusion and fluid flow (in certain parameter regimes), despite their simplicity at the microscale. Motivated by current interest in quantum computation we recently defined quantum lattice gas automata; in this paper we initiate a project to analyze which physical processes these models can effectively simulate. Studying the single particle sector of a one-dimensional quantum lattice gas we find discrete analogs of plane waves and wave packets, and then investigate their behavior in the presence of inhomogeneous potentials. copyright 1997 The American Physical Society

  3. Potential risks of nanotechnology to humans and environment: implications and response mechanisms in Africa

    CSIR Research Space (South Africa)

    Musee, N

    2011-11-01

    Full Text Available www.csir.co.za ENM exposure routes, uptake and potential translocation Dermal Oral Inhalation Ocular Lymphatic System Gastro- intestinal Tract Organs Circulatory System (blood) Respiratory Tract Brain Nasal Cavity Yokel et al. 2011 N... fibrosarcoma cells (left) and human skin/carcinoma cells (right). (A) unexposed cells; (B?F) 24 h after exposure to 3.12, 6.25, 12.5, 25 & 50 ?g/mL nAg respectively (magnification 200?). ? At higher concentrations cells became less polyhedral, more fusiform...

  4. Let the sun shine in: mechanisms and potential for therapeutics in skin photodamage.

    Science.gov (United States)

    Wondrak, Georg T

    2007-05-01

    Photoaging and photocarcinogenesis are the two Janus faces of skin photodamage. Reactivity-based design of prototype agents that antagonize, modulate and reverse the chemistry of skin photodamage holds promise in delivering unprecedented therapeutic benefit. In contrast to structure-based approaches that use selective ligands to target macromolecules, reactivity-based drug discovery uses chemical reagents as therapeutics to target reactive chemical species as key mediators of skin photo-oxidative stress. The following classes of reactivity-based agents for skin photoprotection can be distinguished based on their mechanism of action: direct antagonists of photo-oxidative stress (sunscreens, quenchers of photo-excited states, antioxidants, redox modulators and glycation inhibitors) and skin photo-adaptation inducers (nuclear factor erythroid 2-related factor 2 [Nrf2] activators, heat-shock response inducers and metallothionein inducers).

  5. Aging and atherosclerosis: mechanisms, functional consequences, and potential therapeutics for cellular senescence.

    Science.gov (United States)

    Wang, Julie C; Bennett, Martin

    2012-07-06

    Atherosclerosis is classed as a disease of aging, such that increasing age is an independent risk factor for the development of atherosclerosis. Atherosclerosis is also associated with premature biological aging, as atherosclerotic plaques show evidence of cellular senescence characterized by reduced cell proliferation, irreversible growth arrest and apoptosis, elevated DNA damage, epigenetic modifications, and telomere shortening and dysfunction. Not only is cellular senescence associated with atherosclerosis, there is growing evidence that cellular senescence promotes atherosclerosis. This review examines the pathology of normal vascular aging, the evidence for cellular senescence in atherosclerosis, the mechanisms underlying cellular senescence including reactive oxygen species, replication exhaustion and DNA damage, the functional consequences of vascular cell senescence, and the possibility that preventing accelerated cellular senescence is a therapeutic target in atherosclerosis.

  6. Integrated modeling and field study of potential mechanisms forinduced seismicity at The Geysers Goethermal Field, California

    Energy Technology Data Exchange (ETDEWEB)

    Rutqvist, Jonny; Majer, Ernie; Oldenburg, Curt; Peterson, John; Vasco, Don

    2006-06-07

    In this paper, we present progress made in a study aimed atincreasing the understanding of the relative contributions of differentmechanisms that may be causing the seismicity occurring at The Geysersgeothermal field, California. The approach we take is to integrate: (1)coupled reservoir geomechanical numerical modeling, (2) data fromrecently upgraded and expanded NCPA/Calpine/LBNL seismic arrays, and (3)tens of years of archival InSAR data from monthly satellite passes. Wehave conducted a coupled reservoir geomechanical analysis to studypotential mechanisms induced by steam production. Our simulation resultscorroborate co-locations of hypocenter field observations of inducedseismicity and their correlation with steam production as reported in theliterature. Seismic and InSAR data are being collected and processed foruse in constraining the coupled reservoir geomechanicalmodel.

  7. Beyond COX-1: the effects of aspirin on platelet biology and potential mechanisms of chemoprevention.

    Science.gov (United States)

    Ornelas, Argentina; Zacharias-Millward, Niki; Menter, David G; Davis, Jennifer S; Lichtenberger, Lenard; Hawke, David; Hawk, Ernest; Vilar, Eduardo; Bhattacharya, Pratip; Millward, Steven

    2017-06-01

    After more than a century, aspirin remains one of the most commonly used drugs in western medicine. Although mainly used for its anti-thrombotic, anti-pyretic, and analgesic properties, a multitude of clinical studies have provided convincing evidence that regular, low-dose aspirin use dramatically lowers the risk of cancer. These observations coincide with recent studies showing a functional relationship between platelets and tumors, suggesting that aspirin's chemopreventive properties may result, in part, from direct modulation of platelet biology and biochemistry. Here, we present a review of the biochemistry and pharmacology of aspirin with particular emphasis on its cyclooxygenase-dependent and cyclooxygenase-independent effects in platelets. We also correlate the results of proteomic-based studies of aspirin acetylation in eukaryotic cells with recent developments in platelet proteomics to identify non-cyclooxygenase targets of aspirin-mediated acetylation in platelets that may play a role in its chemopreventive mechanism.

  8. Repaglinide-gemfibrozil drug interaction: inhibition of repaglinide glucuronidation as a potential additional contributing mechanism.

    Science.gov (United States)

    Gan, Jinping; Chen, Weiqi; Shen, Hong; Gao, Ling; Hong, Yang; Tian, Yuan; Li, Wenying; Zhang, Yueping; Tang, Yuwei; Zhang, Hongjian; Humphreys, William Griffith; Rodrigues, A David

    2010-12-01

    To further explore the mechanism underlying the interaction between repaglinide and gemfibrozil, alone or in combination with itraconazole. Repaglinide metabolism was assessed in vitro (human liver subcellular fractions, fresh human hepatocytes, and recombinant enzymes) and the resulting incubates were analyzed, by liquid chromatography-mass spectrometry (LC-MS) and radioactivity counting, to identify and quantify the different metabolites therein. Chemical inhibitors, in addition to a trapping agent, were also employed to elucidate the importance of each metabolic pathway. Finally, a panel of human liver microsomes (genotyped for UGT1A1*28 allele status) was used to determine the importance of UGT1A1 in the direct glucuronidation of repaglinide. The results of the present study demonstrate that repaglinide can undergo direct glucuronidation, a pathway that can possibly contribute to the interaction with gemfibrozil. For example, [³H]-repaglinide formed glucuronide and oxidative metabolites (M2 and M4) when incubated with primary human hepatocytes. Gemfibrozil effectively inhibited (∼78%) both glucuronide and M4 formation, but had a minor effect on M2 formation. Concomitantly, the overall turnover of repaglinide was also inhibited (∼80%), and was completely abolished when gemfibrozil was co-incubated with itraconazole. These observations are in qualitative agreement with the in vivo findings. UGT1A1 plays a significant role in the glucuronidation of repaglinide. In addition, gemfibrozil and its glucuronide inhibit repaglinide glucuronidation and the inhibition by gemfibrozil glucuronide is time-dependent. Inhibition of UGT enzymes, especially UGT1A1, by gemfibrozil and its glucuronide is an additional mechanism to consider when rationalizing the interaction between repaglinide and gemfibrozil. © 2010 The Authors. British Journal of Clinical Pharmacology © 2010 The British Pharmacological Society.

  9. Reduced neophobia: a potential mechanism explaining the emergence of self-medicative behavior in sheep.

    Science.gov (United States)

    Egea, A Vanina; Hall, Jeffery O; Miller, James; Spackman, Casey; Villalba, Juan J

    2014-08-01

    Gastrointestinal helminths challenge ruminants in ways that reduce their fitness. In turn, ruminants have evolved physiological and behavioral adaptations that counteract this challenge. For instance, emerging behavioral evidence suggests that ruminants self-select medicinal compounds and foods that reduce parasitic burdens. However, the mechanism/s leading to self-medicative behaviors in sick animals is still unknown. We hypothesized that when homeostasis is disturbed by a parasitic infection, consumers should respond by increasing the acceptability of novel foods relative to healthy individuals. Three groups of lambs (N=10) were dosed with 0 (Control-C), 5000 (Medium-M) and 15000 (High-H) L3 stage larvae of Haemonchus contortus. When parasites had reached the adult stage, all animals were offered novel foods and flavors in pens and then novel forages at pasture. Ingestive responses by parasitized lambs were different from non-parasitized Control animals and they varied with the type of food and flavor on offer. Parasitized lambs consumed initially more novel beet pulp and less novel beet pulp mixed with tannins than Control lambs, but the pattern reversed after 9d of exposure to these foods. Parasitized lambs ingested more novel umami-flavored food and less novel bitter-flavored food than Control lambs. When offered choices of novel unflavored and bitter-flavored foods or different forage species to graze, parasitized lambs selected a more diverse array of foods than Control lambs. Reductions in food neophobia or selection of a more diverse diet may enhance the likelihood of sick herbivores encountering novel medicinal plants and nutritious forages that contribute to restore health. Published by Elsevier Inc.

  10. Catecholamine biosynthesis pathway potentially involved in banana defense mechanisms to crown rot disease.

    Science.gov (United States)

    Lassois, L; De Clerck, C; Frettinger, P; De Lapeyre De Bellaire, L; Lepoivre, P; Haïssam Jijakli, M

    2011-01-01

    Variations in Cavendish bananas susceptibility to crown rot disease have been observed (Lassois et al., 2010a), but the molecular mechanisms underlying these quantitative host-pathogen relationships were still unknown. The present study was designed to compare gene expression between bananas (Musa acuminata, AAA, 'Grande-Naine') showing a high post-harvest susceptibility (S+) and bananas showing a low post-harvest susceptibility (S-) to crown rot disease. This comparison was performed between crowns (S+ and S-) collected one hour before standardized artificial inoculations with Colletotrichum musae. Fruit susceptibility was evaluated through lesion size on the crown 13 days later. Gene expression comparisons were performed with the cDNA-AFLP technique (Lassois et al., 2009). This revealed that a gene showing a strong homology with a dopamine-beta-monooxygenase (DoH) is differently expressed between S+ and S (Lassois et al., 2011). Furthermore, semi-quantitative real-time RT-PCR analyses between S+ and S- were applied to confirm the differential expression results for DoH obtained by cDNA-AFLP. Two biological replicates were tested. These semi-quantitative analyses were performed not only on tissues collected one hour before C. musae inoculation but also on crown tissues collected 13 days after inoculation. The real-time RT-PCR confirmed that DoH was upregulated in the S tissues collected at harvest, just before C. musae inoculation. This gene was also highly upregulated in the S- tissues collected 13 days after crown inoculation. Similar results were obtained for both biological replicates. Our results suggest that catecholamine's could play a role in banana defense mechanisms to crown rot disease.

  11. Gender-related differences in irritable bowel syndrome: Potential mechanisms of sex hormones

    Science.gov (United States)

    Meleine, Mathieu; Matricon, Julien

    2014-01-01

    According to epidemiological studies, twice as many women as men are affected by irritable bowel syndrome (IBS) in western countries, suggesting a role for sex hormones in IBS pathophysiology. Despite growing evidence about the implications of sex hormones in IBS symptom modulation, data on mechanisms by which they influence disease development are sparse. This review aims to determine the state of knowledge about the role of sex hormones in sensorimotor dysfunctions and to address the possible interplay of sex hormones with common risk factors associated with IBS. The scientific bibliography was searched using the following keywords: irritable bowel syndrome, sex, gender, ovarian hormone, estradiol, progesterone, testosterone, symptoms, pain, sensitivity, motility, permeability, stress, immune system, brain activity, spinal, supraspinal, imaging. Ovarian hormones variations along the menstrual cycle affect sensorimotor gastrointestinal function in both healthy and IBS populations. They can modulate pain processing by interacting with neuromodulator systems and the emotional system responsible for visceral pain perception. These hormones can also modulate the susceptibility to stress, which is a pivotal factor in IBS occurrence and symptom severity. For instance, estrogen-dependent hyper-responsiveness to stress can promote immune activation or impairments of gut barrier function. In conclusion, whereas it is important to keep in mind that ovarian hormones cannot be considered as a causal factor of IBS, they arguably modulate IBS onset and symptomatology. However, our understanding of the underlying mechanisms remains limited and studies assessing the link between IBS symptoms and ovarian hormone levels are needed to improve our knowledge of the disease evolution with regard to gender. Further studies assessing the role of male hormones are also needed to understand fully the role of sex hormones in IBS. Finally, investigation of brain-gut interactions is critical

  12. Role of the placenta in fetal programming: underlying mechanisms and potential interventional approaches.

    Science.gov (United States)

    Jansson, Thomas; Powell, Theresa L

    2007-07-01

    Adverse influences during fetal life alter the structure and function of distinct cells, organ systems or homoeostatic pathways, thereby 'programming' the individual for an increased risk of developing cardiovascular disease and diabetes in adult life. Fetal programming can be caused by a number of different perturbations in the maternal compartment, such as altered maternal nutrition and reduced utero-placental blood flow; however, the underlying mechanisms remain to be fully established. Perturbations in the maternal environment must be transmitted across the placenta in order to affect the fetus. Here, we review recent insights into how the placenta responds to changes in the maternal environment and discuss possible mechanisms by which the placenta mediates fetal programming. In IUGR (intrauterine growth restriction) pregnancies, the increased placental vascular resistance subjects the fetal heart to increased work load, representing a possible direct link between altered placental structure and fetal programming of cardiovascular disease. A decreased activity of placental 11beta-HSD-2 (type 2 isoform of 11beta-hydroxysteroid dehydrogenase) activity can increase fetal exposure to maternal cortisol, which programmes the fetus for later hypertension and metabolic disease. The placenta appears to function as a nutrient sensor regulating nutrient transport according to the ability of the maternal supply line to deliver nutrients. By directly regulating fetal nutrient supply and fetal growth, the placenta plays a central role in fetal programming. Furthermore, perturbations in the maternal compartment may affect the methylation status of placental genes and increase placental oxidative/nitrative stress, resulting in changes in placental function. Intervention strategies targeting the placenta in order to prevent or alleviate altered fetal growth and/or fetal programming include altering placental growth and nutrient transport by maternally administered IGFs (insulin

  13. An Examination of Drag Reduction Mechanisms in Marine Animals, with Potential Applications to Uninhabited Aerial Vehicles

    Science.gov (United States)

    Musick, John A.; Patterson, Mark R.; Dowd, Wesley W.

    2002-01-01

    Previous engineering research and development has documented the plausibility of applying biomimetic approaches to aerospace engineering. Past cooperation between the Virginia Institute of Marine Science (VIMS) and NASA focused on the drag reduction qualities of the microscale dermal denticles of shark skin. This technology has subsequently been applied to submarines and aircraft. The present study aims to identify and document the three-dimensional geometry of additional macroscale morphologies that potentially confer drag reducing hydrodynamic qualities upon marine animals and which could be applied to enhance the range and endurance of Uninhabited Aerial Vehicles (UAVs). Such morphologies have evolved over eons to maximize organismal energetic efficiency by reducing the energetic input required to maintain cruising speeds in the viscous marine environment. These drag reduction qualities are manifested in several groups of active marine animals commonly encountered by ongoing VIMS research programs: namely sharks, bony fishes such as tunas, and sea turtles. Through spatial data acquired by molding and digital imagery analysis of marine specimens provided by VIMS, NASA aims to construct scale models of these features and to test these potential drag reduction morphologies for application to aircraft design. This report addresses the efforts of VIMS and NASA personnel on this project between January and November 2001.

  14. Novel Browning Agents, Mechanisms, and Therapeutic Potentials of Brown Adipose Tissue

    Directory of Open Access Journals (Sweden)

    Umesh D. Wankhade

    2016-01-01

    Full Text Available Nonshivering thermogenesis is the process of biological heat production in mammals and is primarily mediated by brown adipose tissue (BAT. Through ubiquitous expression of uncoupling protein 1 (Ucp1 on the mitochondrial inner membrane, BAT displays uncoupling of fuel combustion and ATP production in order to dissipate energy as heat. Because of its crucial role in regulating energy homeostasis, ongoing exploration of BAT has emphasized its therapeutic potential in addressing the global epidemics of obesity and diabetes. The recent appreciation that adult humans possess functional BAT strengthens this prospect. Furthermore, it has been identified that there are both classical brown adipocytes residing in dedicated BAT depots and “beige” adipocytes residing in white adipose tissue depots that can acquire BAT-like characteristics in response to environmental cues. This review aims to provide a brief overview of BAT research and summarize recent findings concerning the physiological, cellular, and developmental characteristics of brown adipocytes. In addition, some key genetic, molecular, and pharmacologic targets of BAT/Beige cells that have been reported to have therapeutic potential to combat obesity will be discussed.

  15. Morphological and mechanical characterization of chitosan-calcium phosphate composites for potential application as bone-graft substitutes

    Directory of Open Access Journals (Sweden)

    Guilherme Maia Mulder van de Graaf

    Full Text Available Introduction: Bone diseases, aging and traumas can cause bone loss and lead to bone defects. Treatment of bone defects is challenging, requiring chirurgical procedures. Bone grafts are widely used for bone replacement, but they are limited and expensive. Due to bone graft limitations, natural, semi-synthetic, synthetic and composite materials have been studied as potential bone-graft substitutes. Desirable characteristics of bone-graft substitutes are high osteoinductive and angiogenic potentials, biological safety, biodegradability, bone-like mechanical properties, and reasonable cost. Herein, we prepared and characterized potential bone-graft substitutes composed of calcium phosphate (CP - a component of natural bone, and chitosan (CS - a biocompatible biopolymer. Methods CP-CS composites were synthetized, molded, dried and characterized. The effect of drying temperatures (38 and 60 °C on the morphology, porosity and chemical composition of the composites was evaluated. As well, the effects of drying temperature and period of drying (3, 24, 48 and 72 hours on the mechanical properties - compressive strength, modulus of elasticity and relative deformation-of the demolded samples were investigated. Results Scanning electron microscopy and gas adsorption-desorption analyses of the CS-CP composites showed interconnected pores, indicating that the drying temperature played an important role on pores size and distribution. In addition, drying temperature have altered the color (brownish at 60 °C due to Maillard reaction and the chemical composition of the samples, confirmed by FTIR. Conclusion Particularly, prolonged period of drying have improved mechanical properties of the CS-CP composites dried at 38 °C, which can be designed according to the mechanical needs of the replaceable bone.

  16. Potential Mechanisms Driving Population Variation in Spatial Memory and the Hippocampus in Food-caching Chickadees.

    Science.gov (United States)

    Croston, Rebecca; Branch, Carrie L; Kozlovsky, Dovid Y; Roth, Timothy C; LaDage, Lara D; Freas, Cody A; Pravosudov, Vladimir V

    2015-09-01

    Harsh environments and severe winters have been hypothesized to favor improvement of the cognitive abilities necessary for successful foraging. Geographic variation in winter climate, then, is likely associated with differences in selection pressures on cognitive ability, which could lead to evolutionary changes in cognition and its neural mechanisms, assuming that variation in these traits is heritable. Here, we focus on two species of food-caching chickadees (genus Poecile), which rely on stored food for survival over winter and require the use of spatial memory to recover their stores. These species also exhibit extensive climate-related population level variation in spatial memory and the hippocampus, including volume, the total number and size of neurons, and adults' rates of neurogenesis. Such variation could be driven by several mechanisms within the context of natural selection, including independent, population-specific selection (local adaptation), environment experience-based plasticity, developmental differences, and/or epigenetic differences. Extensive data on cognition, brain morphology, and behavior in multiple populations of these two species of chickadees along longitudinal, latitudinal, and elevational gradients in winter climate are most consistent with the hypothesis that natural selection drives the evolution of local adaptations associated with spatial memory differences among populations. Conversely, there is little support for the hypotheses that environment-induced plasticity or developmental differences are the main causes of population differences across climatic gradients. Available data on epigenetic modifications of memory ability are also inconsistent with the observed patterns of population variation, with birds living in more stressful and harsher environments having better spatial memory associated with a larger hippocampus and a larger number of hippocampal neurons. Overall, the existing data are most consistent with the

  17. Kidney disease models: tools to identify mechanisms and potential therapeutic targets

    Science.gov (United States)

    Bao, Yin-Wu; Yuan, Yuan; Chen, Jiang-Hua; Lin, Wei-Qiang

    2018-01-01

    Acute kidney injury (AKI) and chronic kidney disease (CKD) are worldwide public health problems affecting millions of people and have rapidly increased in prevalence in recent years. Due to the multiple causes of renal failure, many animal models have been developed to advance our understanding of human nephropathy. Among these experimental models, rodents have been extensively used to enable mechanistic understanding of kidney disease induction and progression, as well as to identify potential targets for therapy. In this review, we discuss AKI models induced by surgical operation and drugs or toxins, as well as a variety of CKD models (mainly genetically modified mouse models). Results from recent and ongoing clinical trials and conceptual advances derived from animal models are also explored. PMID:29515089

  18. Insights into potential pathogenesis mechanisms associated with Campylobacter jejuni-induced abortion in ewes.

    Science.gov (United States)

    Sanad, Yasser M; Jung, Kwonil; Kashoma, Isaac; Zhang, Xiaoli; Kassem, Issmat I; Saif, Yehia M; Rajashekara, Gireesh

    2014-11-25

    Campylobacter jejuni is commonly found in the gastrointestinal tract of many food-animals including sheep without causing visible clinical symptoms of disease. However, C. jejuni has been implicated in ovine abortion cases worldwide. Specifically, in the USA, the C. jejuni sheep abortion (SA) clone has been increasingly associated with sheep abortion. In vivo studies in sheep (the natural host) are needed to better characterize the virulence potential and pathogenesis of this clone. Pregnant ewes intravenously (IV) or orally inoculated with ovine or bovine abortion-associated C. jejuni SA clones exhibited partial or complete uterine prolapse with retained placenta, and abortion or stillbirth, whereas delivery of healthy lambs occurred in pregnant ewes inoculated with C. jejuni 81-176 or in the uninfected group. In sheep inoculated with the SA clone, histopathological lesions including suppurative necrotizing placentitis and/or endometritis coincided with: 1) increased apoptotic death of trophoblasts, 2) increased expression of the host genes (e.g. genes encoding interleukin IL-6 and IL-15) related to cellular necrosis and pro-inflammatory responses in uterus, and 3) decreased expression of the genes encoding GATA binding protein 6, chordin, and insulin-like 3 (INSL3) that account for embryonic development in uterus. Immunohistochemistry revealed localization of bacterial antigens in trophoblasts lining the chorioallantoic membrane of ewes inoculated with the C. jejuni SA clone. The results showed that C. jejuni SA clones are capable of causing abortion or stillbirth in experimentally infected sheep. Furthermore, down- or up-regulation of specific genes in the uterus of infected pregnant ewes might implicate host genes in facilitating the disease progression. Since the C. jejuni SA strains share genotypic similarities with clones that have been isolated from human clinical cases of gastroenteritis, these strains might represent a potential public health risk.

  19. BIOLOGICAL CHARACTERISTICS OF PRUSSIAN CARP (CARASSIUS AURATUS GIBELIO (BLOCH, 1782 COMMERCIAL STOCK OF THE DNIEPER-BUG ESTUARY

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    К. Heina

    2017-09-01

    Full Text Available Purpose. To provide the biological assessment of the silver Prussian carp (Carassius auratus gibelio (Bloch, 1782 commercial stock of the Dnieper-Bug estuary in the conditions of the transformed Dnieper river flow. Methodology. During the analysis of the biological state of the Prussian carp commercial stock, the main attention was given to the dynamics of age and sexual structure, length-weight growth rate, absolute fecundity and condition factor. The basic data were collected during the work of control-observation stations of the Institute of Fisheries in the Dnieper-Bug estuary during the current century. The collection and processing of ichthyological materials were performed in accordance with the generally accepted methodologies. Findings. The analysis showed that during the current century, the age structure of the Prussian carp of the Dnieper-Bug estuary was the most labile among other commercial cyprinids. It was found that as a result of an increase in the right wing of the age series, there was a gradual increase of the mean weighted age of its commercial stock. At the beginning of studies (2001-2002, the core of the stock was formed by age-3-6 fish (up ; however in subsequent years, a displacement of dominant groups toward the dominance of age-4-7 fish (more than 80% of the total stock was observed. At the same time, the relative number of age-3 fish (recruits was at a relatively high level – up to 10.6%. The linear growth varied more intensively until the age-5, but it reduced with ageing and did not show high variability. The body weight most variable was in age-4 fish (Cv=9.62%. The noted insignificant deviations in the body weight growth rate of the right wing of the age series was due to stable predominance of females in the stock structure, which were characterized by a variability of the mean weight as a result of different development of gonads. The dynamics of the age-related changes in the condition factor indicated on a

  20. A potential tension-sensing mechanism that ensures timely anaphase onset upon metaphase spindle orientation.

    Science.gov (United States)

    Rajagopalan, Srividya; Bimbo, Andrea; Balasubramanian, Mohan K; Oliferenko, Snezhana

    2004-01-06

    The spindle orientation checkpoint (SOC) in fission yeast has been proposed to delay metaphase-to-anaphase transition when the spindle poles are misaligned with respect to the long axis of the cell. This checkpoint is activated in the absence of either an actomyosin division ring or astral microtubules. Although the SOC could be overridden in the absence of the transcription factor Atf1p, its mechanistic nature remained unclear. Here, we show that the SOC-triggered metaphase delay depends on a subset of the spindle assembly checkpoint (SAC) components Mph1p and Bub1p. Based on this finding and a detailed imaging of the spindle orientation process, we hypothesized that the spindle pole might contain proteins capable of sensing the achievement of spindle alignment. We identified the kendrin-like spindle pole body resident Pcp1p as a candidate molecule. A targeted mutation in its central domain specifically triggered the SOC in spite of the presence of oriented spindles, causing a metaphase delay that could be relieved in the absence of Mph1p, Bub1p, and Atf1p. Thus, Pcp1p might provide a link between the mechanical process of spindle alignment and the signal transduction that initiates anaphase.

  1. Metatranscriptome Analysis of Fig Flowers Provides Insights into Potential Mechanisms for Mutualism Stability and Gall Induction.

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    Ellen O Martinson

    Full Text Available A striking property of the mutualism between figs and their pollinating wasps is that wasps consistently oviposit in the inner flowers of the fig syconium, which develop into galls that house developing larvae. Wasps typically do not use the outer ring of flowers, which develop into seeds. To better understand differences between gall and seed flowers, we used a metatranscriptomic approach to analyze eukaryotic gene expression within fig flowers at the time of oviposition choice and early gall development. Consistent with the unbeatable seed hypothesis, we found significant differences in gene expression between gall- and seed flowers in receptive syconia prior to oviposition. In particular, transcripts assigned to flavonoids and carbohydrate metabolism were significantly up-regulated in gall flowers relative to seed flowers. In response to oviposition, gall flowers significantly up-regulated the expression of chalcone synthase, which previously has been connected to gall formation in other plants. We propose several genes encoding proteins with signal peptides or associations with venom of other Hymenoptera as candidate genes for gall initiation or growth. This study simultaneously evaluates the gene expression profile of both mutualistic partners in a plant-insect mutualism and provides insight into a possible stability mechanism in the ancient fig-fig wasp association.

  2. Potential markers and metabolic processes involved in the mechanism of radiation-induced heart injury.

    Science.gov (United States)

    Slezak, Jan; Kura, Branislav; Babal, Pavel; Barancik, Miroslav; Ferko, Miroslav; Frimmel, Karel; Kalocayova, Barbora; Kukreja, Rakesh C; Lazou, Antigone; Mezesova, Lucia; Okruhlicova, Ludmila; Ravingerova, Tanya; Singal, Pawan K; Szeiffova Bacova, Barbara; Viczenczova, Csilla; Vrbjar, Norbert; Tribulova, Narcis

    2017-10-01

    Irradiation of normal tissues leads to acute increase in reactive oxygen/nitrogen species that serve as intra- and inter-cellular signaling to alter cell and tissue function. In the case of chest irradiation, it can affect the heart, blood vessels, and lungs, with consequent tissue remodelation and adverse side effects and symptoms. This complex process is orchestrated by a large number of interacting molecular signals, including cytokines, chemokines, and growth factors. Inflammation, endothelial cell dysfunction, thrombogenesis, organ dysfunction, and ultimate failing of the heart occur as a pathological entity - "radiation-induced heart disease" (RIHD) that is major source of morbidity and mortality. The purpose of this review is to bring insights into the basic mechanisms of RIHD that may lead to the identification of targets for intervention in the radiotherapy side effect. Studies of authors also provide knowledge about how to select targeted drugs or biological molecules to modify the progression of radiation damage in the heart. New prospective studies are needed to validate that assessed factors and changes are useful as early markers of cardiac damage.

  3. Coumarins as Potential Antioxidant Agents Complemented with Suggested Mechanisms and Approved by Molecular Modeling Studies

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    Yasameen K. Al-Majedy

    2016-01-01

    Full Text Available Syntheses of coumarins, which are a structurally interesting antioxidant activity, was done in this article. The modification of 7-hydroxycoumarin by different reaction steps was done to yield target compounds. Molecular structures were characterized by different spectroscopical techniques (Fourier transformation infrared and nuclear magnetic resonance. Antioxidant activities were performed by using various in vitro spectrophometric assays against 1,1-diphenyl-2-picrylhydrazyl (DPPH radical and hydrogen peroxide (H2O2. All compounds exhibited high efficiency as antioxidants compared to ascorbic acid. The highest efficiency scavenging activity was found for compound 3 (91.0 ± 5.0, followed by compounds 2 and 4 (88.0 ± 2.00; and 87.0 ± 3.00. Ascorbic acid C was used as a standard drug with a percentage inhibition of 91.00 ± 1.5. The mechanism of the synthesized compounds as antioxidants was also studied. Hartree–Fock–based quantum chemical studies have been carried out with the basis set to 3-21G, in order to obtain information about the three-dimensional (3D geometries, electronic structure, molecular modeling, and electronic levels, namely HOMO (highest occupied molecular orbital and LUMO (lowest unoccupied molecular orbital, to understand the antioxidant activity for the synthesized compounds.

  4. Potential of garlic (Allium sativum in lowering high blood pressure: mechanisms of action and clinical relevance

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    Ried K

    2014-12-01

    Full Text Available Karin Ried, Peter Fakler National Institute of Integrative Medicine, Melbourne, VIC, Australia Abstract: Garlic supplements have shown promise in the treatment of uncontrolled hypertension, lowering blood pressure (BP by about 10 mmHg systolic and 8 mmHg diastolic, similar to standard BP medication. Aged garlic extract, which contains S-allylcysteine as the bioactive sulfur compound, in particular is standardizable and highly tolerable, with little or no known harmful interaction when taken with other BP-reducing or blood-thinning medication. Here we describe biologically plausible mechanisms of garlic's BP-lowering effect. Garlic-derived polysulfides stimulate the production of the vascular gasotransmitter hydrogen sulfide (H2S and enhance the regulation of endothelial nitric oxide (NO, which induce smooth muscle cell relaxation, vasodilation, and BP reduction. Several dietary and genetic factors influence the efficiency of the H2S and NO signaling pathways and may contribute to the development of hypertension. Sulfur deficiency might play a part in the etiology of hypertension, and could be alleviated with supplementation of organosulfur compounds derived from garlic. Keywords: garlic, S-allylcysteine, hydrogen sulfide (H2S, nitric oxide (NO, redox signaling, hypertension

  5. Metatranscriptome Analysis of Fig Flowers Provides Insights into Potential Mechanisms for Mutualism Stability and Gall Induction.

    Science.gov (United States)

    Martinson, Ellen O; Hackett, Jeremiah D; Machado, Carlos A; Arnold, A Elizabeth

    2015-01-01

    A striking property of the mutualism between figs and their pollinating wasps is that wasps consistently oviposit in the inner flowers of the fig syconium, which develop into galls that house developing larvae. Wasps typically do not use the outer ring of flowers, which develop into seeds. To better understand differences between gall and seed flowers, we used a metatranscriptomic approach to analyze eukaryotic gene expression within fig flowers at the time of oviposition choice and early gall development. Consistent with the unbeatable seed hypothesis, we found significant differences in gene expression between gall- and seed flowers in receptive syconia prior to oviposition. In particular, transcripts assigned to flavonoids and carbohydrate metabolism were significantly up-regulated in gall flowers relative to seed flowers. In response to oviposition, gall flowers significantly up-regulated the expression of chalcone synthase, which previously has been connected to gall formation in other plants. We propose several genes encoding proteins with signal peptides or associations with venom of other Hymenoptera as candidate genes for gall initiation or growth. This study simultaneously evaluates the gene expression profile of both mutualistic partners in a plant-insect mutualism and provides insight into a possible stability mechanism in the ancient fig-fig wasp association.

  6. Anabolic-Androgenic Steroids and Condom Use: Potential Mechanisms in Adolescent Males

    Science.gov (United States)

    Blashill, Aaron J.; Gordon, Janna R.; Safren, Steven A.

    2013-01-01

    Previous research has revealed a significant bivariate relationship between anabolic androgenic steroid (AAS) use and reduced condom use among adolescent boys. However, to date, no known studies have explored the psychological mechanisms that may explain this relationship. Thus, the current study sought to examine two possible mediators in the association between AAS and condom use—depressive symptoms and substance use. Data were extracted from a nationally representative sample of U.S. adolescents. Participants were 3,780 U.S. high school boys who responded to self-report items assessing a number of health behaviors, including symptoms of depression, substance use, AAS use, and use of condoms during their most recent act of intercourse. Both depression and substance use were significant mediators in the relationship between AAS and condom use. However, when these effects were contrasted, the indirect effect of substance use was significantly stronger in magnitude than the effect of depression. Although AAS use is associated with sexual risk behaviors among adolescent boys, significant variance in this relationship is accounted for by elevated levels of depression and substance use, with substance use demonstrating a particularly salient pathway. PMID:23718635

  7. Self-propulsion of dew drops on lotus leaves: a potential mechanism for self cleaning.

    Science.gov (United States)

    Watson, Gregory S; Gellender, Marty; Watson, Jolanta A

    2014-01-01

    This study shows that condensation on the hierarchically structured lotus leaf can facilitate self-propulsion of water droplets off the surface. Droplets on leaves inclined at high angles can be completely removed from the surface by self-propulsion with the assistance of gravity. Due to the small size of mobile droplets, light breezes may also fully remove the propelled droplets, which are typically projected beyond the boundary layer of the leaf cuticle. Moreover the self-propelled droplets/condensate were able to remove contaminants (eg silica particles) from the leaf surface. The biological significance of this process may be associated with maintaining a healthy cuticle surface when the action of rain to clean the surface via the lotus effect is not possible (due to no precipitation). Indeed, the native lotus plants in this study were located in a region with extended time periods (several months) without rain. Thus, dew formation on the leaf may provide an alternative self-cleaning mechanism during times of drought and optimise the functional efficiency of the leaf surface as well as protecting the surface from long term exposure to pathogens such as bacteria and fungi.

  8. Self-disgust as a potential mechanism underlying the association between PTSD and suicide risk.

    Science.gov (United States)

    Brake, C Alex; Rojas, Sasha M; Badour, Christal L; Dutton, Courtney E; Feldner, Matthew T

    2017-04-01

    Suicide risk is highly prevalent among individuals with posttraumatic stress disorder (PTSD). Self-disgust, defined as disgust directed internally and comprised of disgust with oneself (disgusting self) and with one's behaviors (disgusting ways), may impact this increased risk. The present study examined self-disgust as a putative mechanism linking PTSD symptoms with suicide risk. A sample of 347 trauma-exposed undergraduates completed measures of PTSD symptoms, suicide risk, self-disgust, and depressive symptoms. Controlling for depressive symptoms, a process model indicated PTSD symptoms were positively linked to suicide risk via increased disgusting self but not disgusting ways. Process models examining individual PTSD symptom clusters revealed positive, indirect links between all PTSD symptom clusters except alterations in arousal and reactivity and suicide risk via disgusting self. These findings expand on growing literature documenting the importance of self-disgust in trauma-related pathology by identifying connections with suicide risk. Future directions and clinical considerations are discussed. Copyright © 2017 Elsevier Ltd. All rights reserved.

  9. Ketogenic diets as an adjuvant cancer therapy: History and potential mechanism

    Science.gov (United States)

    Allen, Bryan G.; Bhatia, Sudershan K.; Anderson, Carryn M.; Eichenberger-Gilmore, Julie M.; Sibenaller, Zita A.; Mapuskar, Kranti A.; Schoenfeld, Joshua D.; Buatti, John M.; Spitz, Douglas R.; Fath, Melissa A.

    2014-01-01

    Cancer cells, relative to normal cells, demonstrate significant alterations in metabolism that are proposed to result in increased steady-state levels of mitochondrial-derived reactive oxygen species (ROS) such as O2•−and H2O2. It has also been proposed that cancer cells increase glucose and hydroperoxide metabolism to compensate for increased levels of ROS. Given this theoretical construct, it is reasonable to propose that forcing cancer cells to use mitochondrial oxidative metabolism by feeding ketogenic diets that are high in fats and low in glucose and other carbohydrates, would selectively cause metabolic oxidative stress in cancer versus normal cells. Increased metabolic oxidative stress in cancer cells would in turn be predicted to selectively sensitize cancer cells to conventional radiation and chemotherapies. This review summarizes the evidence supporting the hypothesis that ketogenic diets may be safely used as an adjuvant therapy to conventional radiation and chemotherapies and discusses the proposed mechanisms by which ketogenic diets may enhance cancer cell therapeutic responses. PMID:25460731

  10. Mechanical properties of electrospun bilayer fibrous membranes as potential scaffolds for tissue engineering.

    Science.gov (United States)

    Pu, Juan; Komvopoulos, Kyriakos

    2014-06-01

    Bilayer fibrous membranes of poly(l-lactic acid) (PLLA) were fabricated by electrospinning, using a parallel-disk mandrel configuration that resulted in the sequential deposition of a layer with fibers aligned across the two parallel disks and a layer with randomly oriented fibers, both layers deposited in a single process step. Membrane structure and fiber alignment were characterized by scanning electron microscopy and two-dimensional fast Fourier transform. Because of the intricacies of the generated electric field, bilayer membranes exhibited higher porosity than single-layer membranes consisting of randomly oriented fibers fabricated with a solid-drum collector. However, despite their higher porosity, bilayer membranes demonstrated generally higher elastic modulus, yield strength and toughness than single-layer membranes with random fibers. Bilayer membrane deformation at relatively high strain rates comprised multiple abrupt microfracture events characterized by discontinuous fiber breakage. Bilayer membrane elongation yielded excessive necking of the layer with random fibers and remarkable fiber stretching (on the order of 400%) in the layer with fibers aligned in the stress direction. In addition, fibers in both layers exhibited multiple localized necking, attributed to the nonuniform distribution of crystalline phases in the fibrillar structure. The high membrane porosity, good mechanical properties, and good biocompatibility and biodegradability of PLLA (demonstrated in previous studies) make the present bilayer membranes good scaffold candidates for a wide range of tissue engineering applications. Copyright © 2014 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

  11. Methylation on RNA: A Potential Mechanism Related to Immune Priming within But Not across Generations.

    Science.gov (United States)

    Castro-Vargas, Cynthia; Linares-López, César; López-Torres, Adolfo; Wrobel, Katarzyna; Torres-Guzmán, Juan C; Hernández, Gloria A G; Wrobel, Kazimierz; Lanz-Mendoza, Humberto; Contreras-Garduño, Jorge

    2017-01-01

    Invertebrate immune priming is a growing field in immunology. This phenomenon refers to the ability of invertebrates to generate a more vigorous immune response to a second encounter with a specific pathogen and can occur within and across generations. Although the precise mechanism has not been elucidated, it has been suggested that methylation of DNA is a cornerstone for this phenomenon. Here, using a novel method of analytical chemistry (a reversed-phase liquid chromatography procedure) and the beetle Tenebrio molitor as a model system, we did not find evidence to support this hypothesis taking into account the percentage of methylated cytosine entities in DNA (5mdC) within or across generations. However, we found a lower percentage of methylated cytosine entities in RNA (5mC) within but not across generations in immune priming experiments with adults against the bacteria Micrococcus lysodeikticus and larvae against the fungus Metarhizium anisopliae . To our knowledge, this is the first report suggesting a role of differential methylation on RNA during immune priming within generations.

  12. Ketogenic diets as an adjuvant cancer therapy: History and potential mechanism.

    Science.gov (United States)

    Allen, Bryan G; Bhatia, Sudershan K; Anderson, Carryn M; Eichenberger-Gilmore, Julie M; Sibenaller, Zita A; Mapuskar, Kranti A; Schoenfeld, Joshua D; Buatti, John M; Spitz, Douglas R; Fath, Melissa A

    2014-01-01

    Cancer cells, relative to normal cells, demonstrate significant alterations in metabolism that are proposed to result in increased steady-state levels of mitochondrial-derived reactive oxygen species (ROS) such as O2(•-)and H2O2. It has also been proposed that cancer cells increase glucose and hydroperoxide metabolism to compensate for increased levels of ROS. Given this theoretical construct, it is reasonable to propose that forcing cancer cells to use mitochondrial oxidative metabolism by feeding ketogenic diets that are high in fats and low in glucose and other carbohydrates, would selectively cause metabolic oxidative stress in cancer versus normal cells. Increased metabolic oxidative stress in cancer cells would in turn be predicted to selectively sensitize cancer cells to conventional radiation and chemotherapies. This review summarizes the evidence supporting the hypothesis that ketogenic diets may be safely used as an adjuvant therapy to conventional radiation and chemotherapies and discusses the proposed mechanisms by which ketogenic diets may enhance cancer cell therapeutic responses. © 2014 Published by Elsevier Ltd.

  13. Ketogenic diets as an adjuvant cancer therapy: History and potential mechanism

    Directory of Open Access Journals (Sweden)

    Bryan G. Allen

    2014-01-01

    Full Text Available Cancer cells, relative to normal cells, demonstrate significant alterations in metabolism that are proposed to result in increased steady-state levels of mitochondrial-derived reactive oxygen species (ROS such as O2•−and H2O2. It has also been proposed that cancer cells increase glucose and hydroperoxide metabolism to compensate for increased levels of ROS. Given this theoretical construct, it is reasonable to propose that forcing cancer cells to use mitochondrial oxidative metabolism by feeding ketogenic diets that are high in fats and low in glucose and other carbohydrates, would selectively cause metabolic oxidative stress in cancer versus normal cells. Increased metabolic oxidative stress in cancer cells would in turn be predicted to selectively sensitize cancer cells to conventional radiation and chemotherapies. This review summarizes the evidence supporting the hypothesis that ketogenic diets may be safely used as an adjuvant therapy to conventional radiation and chemotherapies and discusses the proposed mechanisms by which ketogenic diets may enhance cancer cell therapeutic responses.

  14. Aquatic respiration as a potential survival mechanism of Brephidium pseudofea (Lepidoptera: Lycaenidae) larvae to intertidal environments.

    Science.gov (United States)

    Warren, V; Daniels, J C; Hahn, D A

    2011-10-01

    The eastern pygmy blue, Brephidium pseudofea (Morrison) (Lepidoptera: Lycaenidae: Polyommatinae), inhabits intertidal environments that are periodically flooded. The immature stages are subject to salt or brackish water inundation during this time and therefore must endure many stressors, including respiratory limitation and salt exposure. Our goal was to investigate possible mechanisms used by the larval stages of B. pseudofea to endure periodic tidal inundation by using physiological and morphological analyses in comparison with several species of terrestrial lepidopteran larvae. A review of tidal charts showed that the immature stages of B. pseudofea would be prone to complete inundation two to five times per month during the summer months (May to August) and partial submersion for up to 20 d per month during the rest of the year. Larvae of several terrestrial lepidopteran species studied consumed oxygen under water for a limited period, but B. pseudofea demonstrated substantially higher oxygen consumption. Light microscopy of B. pseudofea larvae revealed small air pockets in and around the spiracles when submerged in tap water; these air pockets disappeared when exposed to detergent solution. The resulting air pockets may function as a diffusion layer for oxygen to be absorbed from the surrounding water or may act in conjunction with trans-cuticular gas exchange to meet the larva's respiratory needs. Morphological examination by scanning electron microscopy showed that B. psudofea larvae have distinctively small, clavate setae that appear insufficient to effectively support a functional plastron.

  15. Potential mechanisms for cell-based gene therapy to treat HIV/AIDS.

    Science.gov (United States)

    Herrera-Carrillo, Elena; Berkhout, Ben

    2015-02-01

    An estimated 35 million people are infected with HIV worldwide. Anti-retroviral therapy (ART) has reduced the morbidity and mortality of HIV-infected patients but efficacy requires strict adherence and the treatment is not curative. Most importantly, the emergence of drug-resistant virus strains and drug toxicity can restrict the long-term therapeutic efficacy in some patients. Therefore, novel treatment strategies that permanently control or eliminate the virus and restore the damaged immune system are required. Gene therapy against HIV infection has been the topic of intense investigations for the last two decades because it can theoretically provide such a durable anti-HIV control. In this review we discuss two major gene therapy strategies to combat HIV. One approach aims to kill HIV-infected cells and the other is based on the protection of cells from HIV infection. We discuss the underlying molecular mechanisms for candidate approaches to permanently block HIV infection, including the latest strategies and future therapeutic applications. Hematopoietic stem cell-based gene therapy for HIV/AIDS may eventually become an alternative for standard ART and should ideally provide a functional cure in which the virus is durably controlled without medication. Recent results from preclinical research and early-stage clinical trials support the feasibility and safety of this novel strategy.

  16. Potential Mechanism of Action of meso-Dihydroguaiaretic Acid on Mycobacterium tuberculosis H37Rv

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    Aldo F. Clemente-Soto

    2014-12-01

    Full Text Available The isolation and characterization of the lignan meso-dihydroguaiaretic acid (MDGA from Larrea tridentata and its activity against Mycobacterial tuberculosis has been demonstrated, but no information regarding its mechanism of action has been documented. Therefore, in this study we carry out the gene expression from total RNA obtained from M. tuberculosis H37Rv treated with MDGA using microarray technology, which was validated by quantitative real time polymerase chain reaction. Results showed that the alpha subunit of coenzyme A transferase of M. tuberculosis H37Rv is present in both geraniol and 1-and 2-methylnaphthalene degradation pathways, which are targeted by MDGA. This assumption was supported by molecular docking which showed stable interaction between MDGA with the active site of the enzyme. We propose that inhibition of coenzyme A transferase of M. tuberculosis H37Rv results in the accumulation of geraniol and 1-and 2-methylnaphtalene inside bacteria, causing membrane destabilization and death of the pathogen. The natural product MDGA is thus an attractive template to develop new anti-tuberculosis drugs, because its target is different from those of known anti-tubercular agents.

  17. Central Sensitization of Mechanical Nociceptive Pathways Is Associated with a Long-Lasting Increase of Pinprick-Evoked Brain Potentials.

    Science.gov (United States)

    van den Broeke, Emanuel N; Lambert, Julien; Huang, Gan; Mouraux, André

    2016-01-01

    Intense or sustained nociceptor activation, occurring, for example, after skin injury, can induce "central sensitization," i.e., an increased responsiveness of nociceptive neurons in the central nervous system. A hallmark of central sensitization is increased mechanical pinprick sensitivity in the area surrounding the injured skin. The aim of the present study was to identify changes in brain activity related to this increased pinprick sensitivity. In 20 healthy volunteers, increased pinprick sensitivity was induced using high frequency electrical stimulation of the forearm skin (HFS). Mechanical pinprick stimulation (64 and 90 mN) was used to elicit event-related brain potentials (ERPs). The recordings were performed before, 20 min after and 45 min after applying HFS. The contralateral non-sensitized arm served as control. Pinprick stimulation of 64 mN, but not 90 mN, applied in the area of increased pinprick sensitivity elicited a significant increase of a late-latency positive wave, between 300 and 1100 ms after stimulus onset and was maximal at midline posterior electrodes. Most importantly, this increase in EEG activity followed the time course of the increase in pinprick perception, both being present 20 and 45 min after applying HFS. Our results show that the central sensitization of mechanical nociceptive pathways, manifested behaviorally as increased pinprick sensitivity, is associated with a long-lasting increase in pinprick-evoked brain potentials provided that a 64 mN stimulation intensity is used.

  18. Lipid peroxidation is another potential mechanism besides pore-formation underlying hemolysis of tentacle extract from the jellyfish Cyanea capillata.

    Science.gov (United States)

    Wang, Tao; Wen, Xiao-Juan; Mei, Xiao-Bin; Wang, Qian-Qian; He, Qian; Zheng, Jie-Min; Zhao, Jie; Xiao, Liang; Zhang, Li-Ming

    2013-01-09

    This study was performed to explore other potential mechanisms underlying hemolysis in addition to pore-formation of tentacle extract (TE) from the jellyfish Cyanea capillata. A dose-dependent increase of hemolysis was observed in rat erythrocyte suspensions and the hemolytic activity of TE was enhanced in the presence of Ca2+, which was attenuated by Ca2+ channel blockers (Diltiazem, Verapamil and Nifedipine). Direct intracellular Ca2+ increase was observed after TE treatment by confocal laser scanning microscopy, and the Ca2+ increase could be depressed by Diltiazem. The osmotic protectant polyethylenglycol (PEG) significantly blocked hemolysis with a molecular mass exceeding 4000 Da. These results support a pore-forming mechanism of TE in the erythrocyte membrane, which is consistent with previous studies by us and other groups. The concentration of malondialdehyde (MDA), an important marker of lipid peroxidation, increased dose-dependently in rat erythrocytes after TE treatment, while in vitro hemolysis of TE was inhibited by the antioxidants ascorbic acid-Vitamin C (Vc)-and reduced glutathione (GSH). Furthermore, in vivo hemolysis and electrolyte change after TE administration could be partly recovered by Vc. These results indicate that lipid peroxidation is another potential mechanism besides pore-formation underlying the hemolysis of TE, and both Ca2+ channel blockers and antioxidants could be useful candidates against the hemolytic activity of jellyfish venoms.

  19. Lipid Peroxidation Is another Potential Mechanism besides Pore-Formation Underlying Hemolysis of Tentacle Extract from the Jellyfish Cyanea capillata

    Directory of Open Access Journals (Sweden)

    Tao Wang

    2013-01-01

    Full Text Available This study was performed to explore other potential mechanisms underlying hemolysis in addition to pore-formation of tentacle extract (TE from the jellyfish Cyanea capillata. A dose-dependent increase of hemolysis was observed in rat erythrocyte suspensions and the hemolytic activity of TE was enhanced in the presence of Ca2+, which was attenuated by Ca2+ channel blockers (Diltiazem, Verapamil and Nifedipine. Direct intracellular Ca2+ increase was observed after TE treatment by confocal laser scanning microscopy, and the Ca2+ increase could be depressed by Diltiazem. The osmotic protectant polyethylenglycol (PEG significantly blocked hemolysis with a molecular mass exceeding 4000 Da. These results support a pore-forming mechanism of TE in the erythrocyte membrane, which is consistent with previous studies by us and other groups. The concentration of malondialdehyde (MDA, an important marker of lipid peroxidation, increased dose-dependently in rat erythrocytes after TE treatment, while in vitro hemolysis of TE was inhibited by the antioxidants ascorbic acid—Vitamin C (Vc—and reduced glutathione (GSH. Furthermore, in vivo hemolysis and electrolyte change after TE administration could be partly recovered by Vc. These results indicate that lipid peroxidation is another potential mechanism besides pore-formation underlying the hemolysis of TE, and both Ca2+ channel blockers and antioxidants could be useful candidates against the hemolytic activity of jellyfish venoms.

  20. Family-based interpersonal psychotherapy for depressed preadolescents: examining efficacy and potential treatment mechanisms.

    Science.gov (United States)

    Dietz, Laura J; Weinberg, Rebecca J; Brent, David A; Mufson, Laura

    2015-03-01

    To conduct a randomized controlled trial to evaluate the preliminary efficacy of family-based interpersonal psychotherapy (FB-IPT) for treating depression in preadolescents (aged 7-12 years) as compared to child-centered therapy (CCT), a supportive and nondirective treatment that closely approximates the standard of care for pediatric depression in community mental health. Preadolescents with depression (N = 42) were randomly assigned FB-IPT or CCT. Pre- and posttreatment assessments included clinician-administered measures of depression, parent- and child-reported depression and anxiety symptoms, and parent-child conflict and interpersonal impairment with peers. Preadolescents receiving FB-IPT had higher rates of remission (66.0% versus 31%), a greater decrease in depressive symptoms from pre- to posttreatment, and lower depressive symptoms at posttreatment (R(2) = 0.35, ΔR(2) = 0.22; B = -8.15, SE = 2.61, t[37] = -3.13, p = .002, F(2) = 0.28) than did preadolescents with depression receiving CCT. Furthermore, preadolescents in the FB-IPT condition reported significant reductions in anxiety and interpersonal impairment compared with preadolescents in the CCT condition. Changes in social and peer impairment from pre- to posttreatment were associated with preadolescents' posttreatment depressive symptoms. There was a significant indirect effect for decreased social impairment accounting for the association between the FB-IPT and preadolescents' posttreatment depressive symptoms. Findings indicate FB-IPT is an effective treatment for preadolescent depression and support further investigation of interpersonal mechanisms by which FB-IPT may reduce preadolescent depression. Clinical trial registration information-Phase II Study of Family Based Interpersonal Psychotherapy (FB-IPT) for Depressed Preadolescents; http://clinicaltrials.gov; NCT02054312. Copyright © 2015 American Academy of Child and Adolescent Psychiatry. Published by Elsevier Inc. All rights

  1. Harmaline Tremor: Underlying Mechanisms in a Potential Animal Model of Essential Tremor

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    Adrian Handforth

    2012-09-01

    Full Text Available Background: Harmaline and harmine are tremorigenic β-carbolines that, on administration to experimental animals, induce an acute postural and kinetic tremor of axial and truncal musculature. This drug-induced action tremor has been proposed as a model of essential tremor. Here we review what is known about harmaline tremor.Methods: Using the terms harmaline and harmine on PubMed, we searched for papers describing the effects of these β-carbolines on mammalian tissue, animals, or humans.Results: Investigations over four decades have shown that harmaline induces rhythmic burst-firing activity in the medial and dorsal accessory inferior olivary nuclei that is transmitted via climbing fibers to Purkinje cells and to the deep cerebellar nuclei, then to brainstem and spinal cord motoneurons. The critical structures required for tremor expression are the inferior olive, climbing fibers, and the deep cerebellar nuclei; Purkinje cells are not required. Enhanced synaptic norepinephrine or blockade of ionic glutamate receptors suppresses tremor, whereas enhanced synaptic serotonin exacerbates tremor. Benzodiazepines and muscimol suppress tremor. Alcohol suppresses harmaline tremor but exacerbates harmaline-associated neural damage. Recent investigations on the mechanism of harmaline tremor have focused on the T-type calcium channel.Discussion: Like essential tremor, harmaline tremor involves the cerebellum, and classic medications for essential tremor have been found to suppress harmaline tremor, leading to utilization of the harmaline model for preclinical testing of antitremor drugs. Limitations are that the model is acute, unlike essential tremor, and only approximately half of the drugs reported to suppress harmaline tremor are subsequently found to suppress tremor in clinical trials.

  2. Deuterium content of water increases depression susceptibility: the potential role of a serotonin-related mechanism.

    Science.gov (United States)

    Strekalova, Tatyana; Evans, Matthew; Chernopiatko, Anton; Couch, Yvonne; Costa-Nunes, João; Cespuglio, Raymond; Chesson, Lesley; Vignisse, Julie; Steinbusch, Harry W; Anthony, Daniel C; Pomytkin, Igor; Lesch, Klaus-Peter

    2015-01-15

    Environmental factors can significantly affect disease prevalence, including neuropsychiatric disorders such as depression. The ratio of deuterium to protium in water shows substantial geographical variation, which could affect disease susceptibility. Thus the link between deuterium content of water and depression was investigated, both epidemiologically, and in a mouse model of chronic mild stress. We performed a correlation analysis between deuterium content of tap water and rates of depression in regions of the USA. Next, we used a 10-day chronic stress paradigm to test whether 2-week deuterium-depleted water treatment (91 ppm) affects depressive-like behavior and hippocampal SERT. The effect of deuterium-depletion on sleep electrophysiology was also evaluated in naïve mice. There was a geographic correlation between a content of deuterium and the prevalence of depression across the USA. In the chronic stress model, depressive-like features were reduced in mice fed with deuterium-depleted water, and SERT expression was decreased in mice treated with deuterium-treated water compared with regular water. Five days of predator stress also suppressed proliferation in the dentate gyrus; this effect was attenuated in mice fed with deuterium-depleted water. Finally, in naïve mice, deuterium-depleted water treatment increased EEG indices of wakefulness, and decreased duration of REM sleep, phenomena that have been shown to result from the administration of selective serotonin reuptake inhibitors (SSRI). Our data suggest that the deuterium content of water may influence the incidence of affective disorder-related pathophysiology and major depression, which might be mediated by the serotoninergic mechanisms. Copyright © 2014 The Authors. Published by Elsevier B.V. All rights reserved.

  3. Potential mechanisms for the association between fall birth and food allergy.

    Science.gov (United States)

    Keet, C A; Matsui, E C; Savage, J H; Neuman-Sunshine, D L; Skripak, J; Peng, R D; Wood, R A

    2012-06-01

    Season of birth has been reported as a risk factor for food allergy, but the mechanisms by which it acts are unknown. Two populations were studied: 5862 children from the National Health and Nutrition Examination Survey (NHANES) III and 1514 well-characterized food allergic children from the Johns Hopkins Pediatric Allergy Clinic (JHPAC). Food allergy was defined as self-report of an acute reaction to a food (NHANES), or as milk, egg, and peanut allergy. Logistic regression compared fall or nonfall birth between (i) food allergic and nonallergic subjects in NHANES, adjusted for ethnicity, age, income, and sex, and (ii) JHPAC subjects and the general Maryland population. For NHANES, stratification by ethnicity and for JHPAC, eczema were examined. Fall birth was more common among food allergic subjects in both NHANES (OR, 1.91; 95% CI, 1.31-2.77) and JHPAC/Maryland (OR, 1.31; 95% CI, 1.18-1.47). Ethnicity interacted with season (OR, 2.34; 95% CI, 1.43-3.82 for Caucasians; OR, 1.19; 95% CI, 0.77-1.86 for non-Caucasians; P = 0.04 for interaction), as did eczema (OR, 1.47; 95% CI, 1.29-1.67 with eczema; OR, 1.00; 95% CI, 0.80-1.23 without eczema; P = 0.002 for interaction). Fall birth is associated with increased risk of food allergy, and this risk is greatest among those most likely to have seasonal variation in vitamin D during infancy (Caucasians) and those at risk for skin barrier dysfunction (subjects with a history of eczema), suggesting that vitamin D and the skin barrier may be implicated in seasonal associations with food allergy. © 2012 John Wiley & Sons A/S.

  4. Mechanisms of Anorexia Cancer Cachexia Syndrome and Potential Benefits of Traditional Medicine and Natural Herbs.

    Science.gov (United States)

    Ming-Hua, Cong; Bao-Hua, Zou; Lei, Yu

    Anorexia cancer cachexia syndrome is prevalent in advanced cancer patients, which is featured by anorexia, decreased dietary intake, body weight loss (skeletal muscle mass loss), and is unable to be reversed by routine nutritional support therapy. Up to now, the main mechanisms involved in cancer cachexia include excessive systemic inflammation, which is represented by increased plasma levels of IL-1, IL-6, TNF-alpha, tumor-induced factors, such as PIF and LMF. These factors eventually act on orexigenic and anorexigenicneurons located in the hypothalamus or protein and lipid metabolism of peripheral tissues, which lead to anorexia, decreased dietary intake, enhanced basic metabolism rate and hypercatabolism. The treatment modality includes early nutritional intervention, physical activity and drug treatment. However, studies about drugs used to treat cachexia are always controversial or merely effective in stimulating appetite and increasing body weight, though not lean body mass. The main target of pharmaceutical treatment is to improve appetite, decrease systemic inflammation and promote anabolic metabolism. Nevertheless, the treatment effectiveness of chemical drugs are not reaching consensus by existing cachexia guidelines. Complementary and alternative medicine (CAM) is recently known as a promising treatment to improve cachaxia status and quality of life of cancer patients. Traditional Chinese medicine (TCM) and natural herbal medicines have been used in the treatment of cancer for thousands of years worldwide, particularly in China. More and more research show that traditional Hanfang (Chinese medicines) and some natural herbs with less side reactions, have the effects of antagonizing pro-inflammatory cytokines, enhancing immune system, inhibiting protein catabolism, boosting the appetite and body weight, which maybe a promising treatment strategy and development tendency for anorexia cancer cachexia syndrome.

  5. Isotope Exchange: a Potential Mechanism Regulating the Natural and Anthropogenic Pb Isotope Budget in Coastal Waters

    Science.gov (United States)

    Chen, M.; Boyle, E. A.; Zurbrick, C.; Carrasco, G. G.; Switzer, A.; Zhao, N.

    2016-02-01

    Two independent studies on anthropogenic Pb and Pb isotopes in coastal corals from the northern Arabian Gulf and the Singapore Straits have shown an isotopic excursion where the main Pb sources discharging to the water move to more crustal-like values, indicating that the Pb in coastal waters might exchange isotopically with crustal particulates without propotional change in concentration. To investigate this issue, Pb isotope exchange is assessed through a closed-system exchange experiment using estuarine waters collected at the Johor River mouth (discharging to the Singapore Straits). During the experiment, a known amount of NBS-981 (206Pb/207Pb=1.093) was spiked into the unfiltered Johor water (dissolved 206Pb/207Pb = 1.199) and the changing isotopic composition of the dissolved Pb was monitored. Shortly after the spike addition, dissolved Pb exhibited 206Pb/207Pb=1.178, reflecting the influence of the spike. Within the following few days, the 206Pb/207Pb in the water increased to >1.190 with limited changes of the dissolved Pb concentration. The observations in closed-system experiment agree with the isotope difference between Singapore aerosol and seawater in our 2-year-long field observations. The kinetics of isotope exchange were assessed using a simple model, which reproduced >70% of the observed Pb isotope variance. Both the close-system experiment and field measurements imply that isotope exchange can be an important mechanism for regulating the Pb and Pb isotopes in coastal waters. Investigations on the distribution of Pb and Pb isotope in estuaries and coastal waters should further assess the role of isotope exchange in ocean Pb chemistry.

  6. Migraine in Gulf War Illness and Chronic Fatigue Syndrome: Prevalence, potential mechanisms, and evaluation

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    Rakib eRayhan

    2013-07-01

    Full Text Available Objective: To assess the prevalence of headache subtypes in Gulf War Illness and Chronic Fatigue Syndrome compared to controls. Background: Migraines are reported in Chronic Fatigue Syndrome (CFS. Approximately, 25% of the military personnel who served in the 1990-1991 Persian Gulf War have developed Gulf War Illness (GWI. Symptoms in GWI share considerable overlap with CFS, including headache complaints. The type and prevalence of headaches in GWI have not been adequately assessed.Methods: 50 GWI, 39 CFS and 45 controls were examined. Participants had structured headache evaluations based on the 2004 International Headache Society criteria. All subjects had history and physical examinations, measurements of systemic hyperalgesia (dolorimetry, assessments for exclusionary indicators, fatigue and symptom related questionnaires. Results: Migraines were detected in 64% of GWI (odds ratio, 11.6, [±95% CI, 4.1 to 32.5] and 82% of CFS subjects (odds ratio, 22.5, [±95% CI, 7.8 to 64.8] compared to only 13% of controls. There was a predominance of females in the CFS compared to GWI and controls. However, gender did not influence migraine status (x2= 2.7; P = 0.101. Measures of fatigue, pain, and other ancillary criteria were comparable between GWI and CFS subjects with and without headache. Conclusion: Results validate previous findings of migraine in CFS and confirms similar increased prevalence in GWI compared to controls. This suggests GWI and CFS subjects share pathophysiological mechanisms that underlie migraine attacks and contribute to the extensive overlap of symptom constructs and disease pathophysiology. The high migraine prevalence warrants the inclusion of a structured headache evaluation that coincides with clinical assessments of GWI and CFS diagnosis.

  7. Potential mechanism for osseointegration of dental implants in Zucker diabetic fatty rats.

    Science.gov (United States)

    Liu, Zhonghao; Zhou, Wenjuan; Tangl, Stefan; Liu, Shutai; Xu, Xin; Rausch-Fan, Xiaohui

    2015-10-01

    Our aim was to investigate the impact of diabetes mellitus and different durations of glycaemic control on early osseointegration of dental implants, and to explore possible mechanisms by measuring the expression of integrin α5β1 and fibronectin in bone around the implant. We divided 33 male Zucker diabetic fatty (ZDF) rats aged 3 months into 3 groups. The first group comprised diabetic rats with dental implants (controls); the second group was treated with insulin and implants were placed simultaneously (exenatide alone group); and the third group was treated with insulin until the serum glucose was at a constant concentration (implants were then inserted (exenatide+normal glucose group). Rats were killed 7, 14, 30, and 60 days after implants had been inserted. The expression of integrin α5β1 and fibronectin in bone around the implants was detected by immunohistochemical analysis in each group. The expression in the exenatide+normal glucose group was stronger than in the other 2 groups. Fourteen days after implantation, expression of integrin α5β1 in the exenatide alone group was significantly stronger than that in the control group (p=0.027), and 60 days after implantation the expression of fibronectin in the exenatide alone group was also significantly stronger than that among the controls (p=0.001). Both fibronectin and integrin α5β1 participate in the adhesion of osteoblasts and act as signals at the bone/implant interface. Diabetes interferes with the osseointegration of implants by deferring expression of fibronectin and integrin α5β1. Copyright © 2015 The British Association of Oral and Maxillofacial Surgeons. Published by Elsevier Ltd. All rights reserved.

  8. Amphetamine elevates nucleus accumbens dopamine via an action potential-dependent mechanism that is modulated by endocannabinoids.

    Science.gov (United States)

    Covey, Dan P; Bunner, Kendra D; Schuweiler, Douglas R; Cheer, Joseph F; Garris, Paul A

    2016-06-01

    The reinforcing effects of abused drugs are mediated by their ability to elevate nucleus accumbens dopamine. Amphetamine (AMPH) was historically thought to increase dopamine by an action potential-independent, non-exocytotic type of release called efflux, involving reversal of dopamine transporter function and driven by vesicular dopamine depletion. Growing evidence suggests that AMPH also acts by an action potential-dependent mechanism. Indeed, fast-scan cyclic voltammetry demonstrates that AMPH activates dopamine transients, reward-related phasic signals generated by burst firing of dopamine neurons and dependent on intact vesicular dopamine. Not established for AMPH but indicating a shared mechanism, endocannabinoids facilitate this activation of dopamine transients by broad classes of abused drugs. Here, using fast-scan cyclic voltammetry coupled to pharmacological manipulations in awake rats, we investigated the action potential and endocannabinoid dependence of AMPH-induced elevations in nucleus accumbens dopamine. AMPH increased the frequency, amplitude and duration of transients, which were observed riding on top of slower dopamine increases. Surprisingly, silencing dopamine neuron firing abolished all AMPH-induced dopamine elevations, identifying an action potential-dependent origin. Blocking cannabinoid type 1 receptors prevented AMPH from increasing transient frequency, similar to reported effects on other abused drugs, but not from increasing transient duration and inhibiting dopamine uptake. Thus, AMPH elevates nucleus accumbens dopamine by eliciting transients via cannabinoid type 1 receptors and promoting the summation of temporally coincident transients, made more numerous, larger and wider by AMPH. Collectively, these findings are inconsistent with AMPH eliciting action potential-independent dopamine efflux and vesicular dopamine depletion, and support endocannabinoids facilitating phasic dopamine signalling as a common action in drug reinforcement

  9. Amphetamine elevates nucleus accumbens dopamine via an action potential-dependent mechanism that is modulated by endocannabinoids

    Science.gov (United States)

    Covey, Dan P.; Bunner, Kendra D.; Schuweiler, Douglas R.; Cheer, Joseph F.; Garris, Paul A.

    2018-01-01

    The reinforcing effects of abused drugs are mediated by their ability to elevate nucleus accumbens dopamine. Amphetamine (AMPH) was historically thought to increase dopamine by an action potential-independent, non-exocytotic type of release called efflux, involving reversal of dopamine transporter function and driven by vesicular dopamine depletion. Growing evidence suggests that AMPH also acts by an action potential-dependent mechanism. Indeed, fast-scan cyclic voltammetry demonstrates that AMPH activates dopamine transients, reward-related phasic signals generated by burst firing of dopamine neurons and dependent on intact vesicular dopamine. Not established for AMPH but indicating a shared mechanism, endocannabinoids facilitate this activation of dopamine transients by broad classes of abused drugs. Here, using fast-scan cyclic voltammetry coupled to pharmacological manipulations in awake rats, we investigated the action potential and endocannabinoid dependence of AMPH-induced elevations in nucleus accumbens dopamine. AMPH increased the frequency, amplitude and duration of transients, which were observed riding on top of slower dopamine increases. Surprisingly, silencing dopamine neuron firing abolished all AMPH-induced dopamine elevations, identifying an action potential-dependent origin. Blocking cannabinoid type 1 receptors prevented AMPH from increasing transient frequency, similar to reported effects on other abused drugs, but not from increasing transient duration and inhibiting dopamine uptake. Thus, AMPH elevates nucleus accumbens dopamine by eliciting transients via cannabinoid type 1 receptors and promoting the summation of temporally coincident transients, made more numerous, larger and wider by AMPH. Collectively, these findings are inconsistent with AMPH eliciting action potential-independent dopamine efflux and vesicular dopamine depletion, and support endocannabinoids facilitating phasic dopamine signalling as a common action in drug reinforcement

  10. Curcumin as a potential candidate for treating hyperlipidemia: A review of cellular and metabolic mechanisms.

    Science.gov (United States)

    Panahi, Yunes; Ahmadi, Yasin; Teymouri, Manouchehr; Johnston, Thomas P; Sahebkar, Amirhossein

    2018-01-01

    Curcumin is an herbal polyphenol extensively investigated for antioxidant, anti-inflammatory, and hypolipidaemic properties. In the present review, the efficacy of curcumin for improving a plasma lipid profile has been evaluated and compared with statins, a well-known class of medicines for treating hypercholesterolemia and hyperlipidaemia. Curcumin is presumably most effective in reducing triglyceride (TG), while statins are most efficient in lowering low-density lipoproteins-cholesterol (LDL-C). Additionally, various molecular and metabolic mediators of cholesterol and plasma lipid homeostasis are discussed in relation to how they are modulated by curcumin or statins. Overall, curcumin influences the same mediators of plasma lipid alteration as statins do. Almost all the pathways through which cholesterol trafficking takes place are affected by these agents. These include gastrointestinal absorption of dietary cholesterol, hepatocellular removal of plasma cholesterol, the mediators of reverse cholesterol transport, and removal of cholesterol from peripheral tissues. Moreover, the reactive oxygen species (ROS) scavenging potential of curcumin limits the risk of lipid peroxidation that triggers inflammatory responses causing cardiovascular diseases (CVD) and atherosclerosis. Taken together, curcumin could be used as a safe and well-tolerated adjunct to statins to control hyperlipidaemia more effectively than statins alone. © 2017 Wiley Periodicals, Inc.

  11. Potentials of Mangifera indica in the treatment of depressive-anxiety disorders: possible mechanisms of action.

    Science.gov (United States)

    Ishola, Ismail O; Awodele, Olufunsho; Eluogu, Chinedum O

    2016-09-01

    Mangifera indica (Anacardiaceae) is an important herb in the traditional African and Ayurvedic medicines. The stem barks are used in the treatment of hypertension, insomnia, tumour, depression, rheumatism and as a tonic. This study was carried out to investigate antidepressant- and anxiolytic-like effect of the hydroethanol stem bark extract of M. indica (HeMI) in mice. HeMI (12.5-100 mg/kg, p.o.) was administered 1 h before subjecting the animal to the forced swim test (FST), tail suspension test (TST) and elevated plus maze tests (EPM). HeMI (12.5-100 mg/kg, p.o.) treatment produced significant reduction in immobility time [F(6.56)=8.35, pindica through interaction with 5-HT2 receptor, α2-adrenoceptor and dopamine D2-receptors. Also, an anxiolytic-like effect through its affinity for 5-HT2 and benzodiazepine receptors. Hence, M. indica could be a potential phytotherapeutic agent in the treatment of mixed anxiety-depressive illness.

  12. Mechanisms of generation of membrane potential resonance in a neuron with multiple resonant ionic currents.

    Directory of Open Access Journals (Sweden)

    David M Fox

    2017-06-01

    Full Text Available Neuronal membrane potential resonance (MPR is associated with subthreshold and network oscillations. A number of voltage-gated ionic currents can contribute to the generation or amplification of MPR, but how the interaction of these currents with linear currents contributes to MPR is not well understood. We explored this in the pacemaker PD neurons of the crab pyloric network. The PD neuron MPR is sensitive to blockers of H- (IH and calcium-currents (ICa. We used the impedance profile of the biological PD neuron, measured in voltage clamp, to constrain parameter values of a conductance-based model using a genetic algorithm and obtained many optimal parameter combinations. Unlike most cases of MPR, in these optimal models, the values of resonant- (fres and phasonant- (fϕ = 0 frequencies were almost identical. Taking advantage of this fact, we linked the peak phase of ionic currents to their amplitude, in order to provide a mechanistic explanation the dependence of MPR on the ICa gating variable time constants. Additionally, we found that distinct pairwise correlations between ICa parameters contributed to the maintenance of fres and resonance power (QZ. Measurements of the PD neuron MPR at more hyperpolarized voltages resulted in a reduction of fres but no change in QZ. Constraining the optimal models using these data unmasked a positive correlation between the maximal conductances of IH and ICa. Thus, although IH is not necessary for MPR in this neuron type, it contributes indirectly by constraining the parameters of ICa.

  13. Mechanisms in endocrinology: vitamin D as a potential contributor in endocrine health and disease.

    Science.gov (United States)

    Muscogiuri, Giovanna; Mitri, Joanna; Mathieu, Chantal; Badenhoop, Klaus; Tamer, Gonca; Orio, Francesco; Mezza, Teresa; Vieth, Reinhold; Colao, Annamaria; Pittas, Anastassios

    2014-09-01

    It has been suggested that vitamin D may play a role in the pathogenesis of several endocrine diseases, such as hyperparathyroidism, type 1 diabetes (T1DM), type 2 diabetes (T2DM), autoimmune thyroid diseases, Addison's disease and polycystic ovary syndrome (PCOS). In this review, we debate the role of vitamin D in the pathogenesis of endocrine diseases. Narrative overview of the literature synthesizing the current evidence retrieved from searches of computerized databases, hand searches and authoritative texts. Evidence from basic science supports a role for vitamin D in many endocrine conditions. In humans, inverse relationships have been reported not only between blood 25-hydroxyvitamin D and parathyroid hormone concentrations but also with risk of T1DM, T2DM, and PCOS. There is less evidence for an association with Addison's disease or autoimmune thyroid disease. Vitamin D supplementation may have a role for prevention of T2DM, but the available evidence is not consistent. Although observational studies support a potential role of vitamin D in endocrine disease, high quality evidence from clinical trials does not exist to establish a place for vitamin D supplementation in optimizing endocrine health. Ongoing randomized controlled trials are expected to provide insights into the efficacy and safety of vitamin D in the management of endocrine disease. © 2014 European Society of Endocrinology.

  14. Anthocyanins in obesity-associated thrombogenesis: a review of the potential mechanism of action.

    Science.gov (United States)

    Thompson, Kiara; Pederick, Wayne; Santhakumar, Abishek Bommannan

    2016-05-18

    Platelet dysfunction, oxidative stress and dyslipidemia are important contributors to pro-thrombotic progression particularly in obese and hyper-cholesterolemic populations. Becoming an increasingly widespread endemic, obesity causes a dysfunction in the metabolic system by initiating endothelial dysfunction; increasing free radical production; lipid peroxidation; platelet hyperactivity and aggregation; thereby accelerating thrombogenesis. In the event of increased free radical generation under pro-thrombotic conditions, antioxidants act as scavengers in reducing physiological oxidative stress; free radical-mediated thrombosis and hemostatic function. Anthocyanin, a subclass of the polyphenol family flavonoids has been shown to exhibit anti-dyslipidemic and anti-thrombotic properties by virtue of its antioxidant activity. Current anti-platelet/coagulant therapeutics target specific receptor pathways to relieve the extent of dysfunction and plaque acceleration in pro-thrombotic individuals. Though effective, they have been associated with high bleeding risk and increased response variability. The following review focuses on the potential role of natural dietary anthocyanins in targeting simultaneous mechanistic pathways in alleviating platelet activation, dyslipidemia, and oxidative stress-associated thrombus acceleration in obese pro-thrombotic populations.

  15. The Effects of Mechanical and Thermal Stimuli on Local Field Potentials and Single Unit Activity in Parkinson's Disease Patients.

    Science.gov (United States)

    Belasen, Abigail; Youn, Youngwon; Gee, Lucy; Prusik, Julia; Lai, Brant; Ramirez-Zamora, Adolfo; Rizvi, Khizer; Yeung, Philip; Shin, Damian S; Argoff, Charles; Pilitsis, Julie G

    2016-10-01

    Chronic pain is a major, debilitating symptom of Parkinson's disease (PD). Although, deep brain stimulation (DBS) has been shown to improve pain outcomes, the mechanisms underlying this phenomenon are unclear. Microelectrode recording allows us to measure both local field potentials (LFPs) and single neuronal unit activity (SUA). In this study, we examined how single unit and LFP oscillatory activity in the basal ganglia are impacted by mechanical and thermal sensory stimuli and explored their role in pain modulation. We assessed changes in LFPs and SUAs in the subthalamic nucleus (STN), globus pallidus interna (Gpi), and globus pallidus externa (Gpe) following exposure with mechanical or thermal stimuli. Sensory thresholds were determined pre-operatively using quantitative sensory testing. Based on these data, patients were exposed to innocuous and noxious mechanical, pressure, and thermal stimuli at individualized thresholds. In the STN, LFP alpha oscillatory activity and SUA increased in response to innocuous mechanical stimuli; SUA further increased in response to noxious mechanical, noxious pressure, and noxious thermal stimuli (p thermal stimuli; SUA also increased in response to innocuous thermal stimuli (p thermal stimuli increased LFP gammaactivity; noxious pressure stimuli decreased low betaactivity; SUA increased in response to noxious thermal stimuli (p thermal stimuli alter basal ganglia LFPs and SUAs in PD. While STN SUA increases nearly uniformly to all sensory stimuli, SUA in the pallidal nuclei respond solely to thermal stimuli. Similarly, thermal stimuli yield increases in pallidal LFP activity, but not STN activity. We speculate that DBS may provide analgesia through suppression of stimuli-specific changes in basal ganglia activity, supporting a role for these nuclei in sensory and pain processing circuits. © 2016 International Neuromodulation Society.

  16. Review article: potential mechanisms of action of rifaximin in the management of irritable bowel syndrome with diarrhoea.

    Science.gov (United States)

    Pimentel, M

    2016-01-01

    The role of gut microbiota in the pathophysiology of irritable bowel syndrome (IBS) is supported by various lines of evidence, including differences in mucosal and faecal microbiota between patients with IBS and healthy individuals, development of post-infectious IBS, and the efficacy of some probiotics and nonsystemic antibiotics (e.g. rifaximin). To review the literature regarding the role of rifaximin in IBS and its potential mechanism(s) of action. A literature search was conducted using the terms 'rifaximin', 'irritable bowel syndrome' and 'mechanism of action'. Rifaximin was approved in 2015 for the treatment of IBS with diarrhoea. In contrast to other currently available IBS therapies that require daily administration to maintain efficacy, 2-week rifaximin treatment achieved symptom improvement that persisted ≥12 weeks post-treatment. The mechanisms of action of rifaximin, therefore, may extend beyond direct bactericidal effects. Data suggest that rifaximin may decrease host proinflammatory responses to bacterial products in patients with IBS. In some cases, small intestinal bacterial overgrowth (SIBO) may play a role in the clinical symptoms of IBS. Because of the high level of solubility of rifaximin in the small intestine, rifaximin may reset microbial diversity in this environment. Consistent with this hypothesis, rifaximin has antibiotic efficacy against isolates derived from patients with SIBO. Resetting microbial diversity via rifaximin use may lead to a decrease in bacterial fermentation and a reduction in the clinical symptoms of IBS. © 2015 John Wiley & Sons Ltd.

  17. Lhermitte's Syndrome After Chemo-IMRT of Head and Neck Cancer: Incidence, Doses, and Potential Mechanisms

    Science.gov (United States)

    Pak, Daniel; Vineberg, Karen; Feng, Felix; Haken, Randall K. Ten; Eisbruch, Avraham

    2012-01-01

    Purpose We have observed a higher rate of Lhermitte's syndrome (LS) after chemo-IMRT of head and neck cancer than the published rates after conventional radiotherapy. We hypothesized that the inhomogeneous spinal cord dose distributions produced by IMRT caused a “bath and shower” effect, characterized by low doses in the vicinity of high doses, reducing spinal cord tolerance. Methods and Materials 73 patients with squamous cell carcinoma of the oropharynx participated in a prospective study of IMRT concurrent with weekly carboplatin and taxol. 15 (21%) reported LS in at least 2 consecutive follow-up visits. Mean dose, maximum dose, partial (Vd) as well as the absolute volume (cc) of spinal cord receiving specified doses (≥10 Gy, 20 Gy, 30 Gy, 40 Gy), and the pattern of dose distributions at the “anatomical” (from the base of the skull to the aortic arch) and “plan-related” (from the top through the bottom of the PTV's) spinal cords were compared between LS and 34 non-LS patients. Results LS patients had significantly higher spinal cord mean doses, V30, V40, and volumes receiving ≥30 and ≥ 40 Gy compared to the non-LS patients (p shower”) in LS compared to non-LS patients. Conclusions Greater mean dose, V30, V40, and cord volumes receiving ≥30 and ≥40 Gy characterized LS compared to non-LS patients. “Bath and shower” effects could not be validated in this study as a potential contributor to LS. The higher than expected rates of LS may be due to the specific concurrent chemotherapy agents, or to more accurate identification of LS in the setting of a prospective study. PMID:22284690

  18. Calcium sensing receptor as a novel mediator of adipose tissue dysfunction: mechanisms and potential clinical implications

    Directory of Open Access Journals (Sweden)

    Roberto Bravo

    2016-09-01

    Full Text Available Obesity is currently a serious worldwide public health problem, reaching pandemic levels. For decades, dietary and behavioral approaches have failed to prevent this disease from expanding, and health authorities are challenged by the elevated prevalence of co-morbid conditions. Understanding how obesity-associated diseases develop from a basic science approach is recognized as an urgent task to face this growing problem. White adipose tissue is an active endocrine organ, with a crucial influence on whole-body homeostasis. White adipose tissue dysfunction plays a key role linking obesity with its associated diseases such as type 2 diabetes mellitus, cardiovascular disease and some cancers. Among the regulators of white adipose tissue physiology, the calcium-sensing receptor has arisen as a potential mediator of white adipose tissue dysfunction. Expression of the receptor has been described in human preadipocytes, adipocytes, and the human adipose cell lines LS14 and SW872. The evidence suggests that calcium-sensing receptor activation in the visceral (i.e. unhealthy white adipose tissue is associated with an increased proliferation of adipose progenitor cells and elevated adipocyte differentiation. In addition, exposure of adipose cells to calcium-sensing receptor activators in vitro elevates proinflammatory cytokine expression and secretion. An increased proinflammatory environment in white adipose tissue plays a key role in the development of white adipose tissue dysfunction that leads to peripheral organ fat deposition and insulin resistance, among other consequences. We propose that calcium-sensing receptor may be one relevant therapeutic target in the struggle to confront the health consequences of the current worldwide obesity pandemic.

  19. Mnemonic discrimination of similar face stimuli and a potential mechanism for the "other race" effect.

    Science.gov (United States)

    Chang, Allen; Murray, Elizabeth; Yassa, Michael A

    2015-10-01

    Face recognition is an important component of successful social interactions in humans. A large literature in social psychology has focused on the phenomenon termed the "other race" (ORE) effect, the tendency to be more proficient with face recognition within one's own ethnic group compared with other ethnic groups. Several potential hypotheses have been proposed for this effect, including perceptual expertise, social grouping, and holistic face processing. Recent work on mnemonic discrimination (i.e., the ability to resolve mnemonic interference among similar experiences) may provide a mechanistic account for the ORE. In the current study, we examined how discrimination and generalization in the presence of mnemonic interference may contribute to the ORE. We developed a database of computerized faces divided evenly among ethnic origins (Black, Caucasian, East Asian, South Asian), as well as morphed face stimuli that varied in the amount of similarity to the original stimuli (30%, 40%, 50%, and 60% morphs). Participants first examined the original unmorphed stimuli during study, then during test were asked to judge the prior occurrence of repetitions (targets), morphed stimuli (lures), and new stimuli (foils). We examined participants' ability to correctly reject similar morphed lures and found that it increased linearly as a function of face dissimilarity. We additionally found that Caucasian participants' mnemonic discrimination-generalization functions were sharply tuned for Caucasian faces but considerably less tuned for East Asian and Black faces. These results suggest that expertise plays an important role in resolving mnemonic interference, which may offer a mechanistic account for the ORE. (c) 2015 APA, all rights reserved).

  20. Analysis of Autophagy Genes in Microalgae: Chlorella as a Potential Model to Study Mechanism of Autophagy

    Science.gov (United States)

    Jiang, Qiao; Zhao, Li; Dai, Junbiao; Wu, Qingyu

    2012-01-01

    Background Microalgae, with the ability to mitigate CO2 emission and produce carbohydrates and lipids, are considered one of the most promising resources for producing bioenergy. Recently, we discovered that autophagy plays a critical role in the metabolism of photosynthetic system and lipids production. So far, more than 30-autophagy related (ATG) genes in all subtypes of autophagy have been identified. However, compared with yeast and mammals, in silico and experimental research of autophagy pathways in microalgae remained limited and fragmentary. Principal Findings In this article, we performed a genome-wide analysis of ATG genes in 7 microalgae species and explored their distributions, domain structures and evolution. Eighteen “core autophagy machinery” proteins, four mammalian-specific ATG proteins and more than 30 additional proteins (including “receptor-adaptor” complexes) in all subtypes of autophagy were analyzed. Data revealed that receptor proteins in cytoplasm-to-vacuole targeting and mitophagy seem to be absent in microalgae. However, most of the “core autophagy machinery” and mammalian-specific proteins are conserved among microalgae, except for the ATG9-cycling system in Chlamydomonas reinhardtii and the second ubiquitin-like protein conjugation complex in several algal species. The catalytic and binding residues in ATG3, ATG5, ATG7, ATG8, ATG10 and ATG12 are also conserved and the phylogenetic tree of ATG8 coincides well with the phylogenies. Chlorella contains the entire set of the core autophagy machinery. In addition, RT-PCR analysis verified that all crucial ATG genes tested are expressed during autophagy in both Chlorella and Chlamydomonas reinhardtii. Finally, we discovered that addition of 3-Methyladenine (a PI3K specific inhibitor) could suppress the formation of autophagic vacuoles in Chlorella. Conclusions Taken together, Chlorella may represent a potential model organism to investigate autophagy pathways in photosynthetic

  1. Mechanical unfolding of proteins: reduction to a single-reaction coordinate unfolding potential, and an application of the Jarzynski Relation

    Science.gov (United States)

    Olmsted, Peter; West, Daniel; Paci, Emanuele

    2007-03-01

    Single molecule force spectroscopy (AFM, optical tweezers, etc) has revolutionized the study of many biopolymers, including DNA, RNA, and proteins. In this talk I will discuss recent work on modelling of mechanical unfolding of proteins, as often probed by AFM. I will address two issues in obtaining a coarse-grained description of protein unfolding: how to project the entire energy landscape onto an effective one dimensional unfolding potential, and how to apply the Jarzynski Relation to extract equilibrium free energies from nonequilibrium unfolding experiments.

  2. Will C3 crops enhanced with the C4 CO2-concentrating mechanism live up to their full potential (yield)?

    Science.gov (United States)

    Driever, Steven M; Kromdijk, Johannes

    2013-10-01

    Sustainably feeding the world's growing population in future is a great challenge and can be achieved only by increasing yield per unit land surface. Efficiency of light interception and biomass partitioning into harvestable parts (harvest index) has been improved substantially via plant breeding in modern crops. The conversion efficiency of intercepted light into biomass still holds promise for yield increase. This conversion efficiency is to a great extent constrained by the metabolic capacity of photosynthesis, defined by the characteristics of its components. Genetic manipulations are increasingly applied to lift these constraints, by improving CO2 or substrate availability for the photosynthetic carbon reduction cycle. Although these manipulations can lead to improved potential growth rates, this increase might be offset by a decrease in performance under stress conditions. In this review, we assess possible positive or negative effects of the introduction of a CO2-concentrating mechanism in C3 crop species on crop potential productivity and yield robustness.

  3. Identification of potential neuromotor mechanisms of manual therapy in patients with musculoskeletal disablement: rationale and description of a clinical trial

    Directory of Open Access Journals (Sweden)

    Kulig Kornelia

    2009-05-01

    Full Text Available Abstract Background Many health care practitioners use a variety of hands-on treatments to improve symptoms and disablement in patients with musculoskeletal pathology. Research to date indirectly suggests a potentially broad effect of manual therapy on the neuromotor processing of functional behavior within the supraspinal central nervous system (CNS in a manner that may be independent of modification at the level of local spinal circuits. However, the effect of treatment speed, as well as the specific mechanism and locus of CNS changes, remain unclear. Methods/Design We developed a placebo-controlled, randomized study to test the hypothesis that manual therapy procedures directed to the talocrural joint in individuals with post-acute ankle sprain induce a change in corticospinal excitability that is relevant to improve the performance of lower extremity functional behavior. Discussion This study is designed to identify potential neuromotor changes associated with manual therapy procedures directed to the appendicular skeleton, compare the relative effect of treatment speed on potential neuromotor effects of manual therapy procedures, and determine the behavioral relevance of potential neuromotor effects of manual therapy procedures. Trial Registration http://www.clinicaltrials.gov identifier NCT00847769.

  4. Identification of up-regulated proteins potentially involved in the antagonism mechanism of Bacillus amyloliquefaciens G1.

    Science.gov (United States)

    Cao, Haipeng; Zheng, Weidong; He, Shan; Wang, Hao; Wang, Tu; Lu, Liqun

    2013-06-01

    The use of Bacillus probiotics has been demonstrated as a promising method in the biocontrol of bacterial diseases in aquaculture. However, the molecular antibacterial mechanism of Bacillus still remains unclear. In order to explore the antibacterial mechanism of the potential antagonistic Bacillus amyloliquefaciens strain G1, comparative proteomics between B. amyloliquefaciens strain G1 and its non-antagonistic mutant strain was investigated. The 2-dimensional electrophoresis gel maps of their total extracted proteins were described and 42 different proteins were found to be highly expressed in strain G1 in comparison with those in the mutant strain. 35 of these up-regulated proteins were successfully identified using MALDI-TOF-TOF MS and databank analysis, and their biological functions were analyzed through the KEGG database. The increased expression of these proteins suggested that high levels of energy metabolism, biosynthesis and stress resistance could play important roles in strain G1's antagonism. To our knowledge, this is the first report on the proteins involved in the antagonism mechanism of B. amyloliquefaciens using a proteomic approach and the proteomic data also contribute to a better understanding of the molecular basis for the antagonism of B. amyloliquefaciens.

  5. Mechanics

    CERN Document Server

    Chester, W

    1979-01-01

    When I began to write this book, I originally had in mind the needs of university students in their first year. May aim was to keep the mathematics simple. No advanced techniques are used and there are no complicated applications. The emphasis is on an understanding of the basic ideas and problems which require expertise but do not contribute to this understanding are not discussed. How­ ever, the presentation is more sophisticated than might be considered appropri­ ate for someone with no previous knowledge of the subject so that, although it is developed from the beginning, some previous acquaintance with the elements of the subject would be an advantage. In addition, some familiarity with element­ ary calculus is assumed but not with the elementary theory of differential equations, although knowledge of the latter would again be an advantage. It is my opinion that mechanics is best introduced through the motion of a particle, with rigid body problems left until the subject is more fully developed. Howev...

  6. Noninvasive Evaluation of Bladder Wall Mechanical Properties as a Function of Filling Volume: Potential Application in Bladder Compliance Assessment.

    Directory of Open Access Journals (Sweden)

    Ivan Nenadic

    Full Text Available We propose a novel method to monitor bladder wall mechanical properties as a function of filling volume, with the potential application to bladder compliance assessment. The proposed ultrasound bladder vibrometry (UBV method uses ultrasound to excite and track Lamb waves on the bladder wall from which its mechanical properties are derived by fitting measurements to an analytical model. Of particular interest is the shear modulus of bladder wall at different volumes, which we hypothesize, is similar to measuring the compliance characteristics of the bladder.Three experimental models were used: 1 an ex vivo porcine model where normal and aberrant (stiffened by formalin bladders underwent evaluation by UBV; 2 an in vivo study to evaluate the performance of UBV on patients with clinically documented compliant and noncompliant bladders undergoing UDS; and 3 a noninvasive UBV protocol to assess bladder compliance using oral hydration and fractionated voiding on three healthy volunteers.The ex vivo studies showed a high correlation between the UBV parameters and direct pressure measurement (R2 = 0.84-0.99. A similar correlation was observed for 2 patients with compliant and noncompliant bladders (R2 = 0.89-0.99 undergoing UDS detrusor pressure-volume measurements. The results of UBV on healthy volunteers, performed without catheterization, were comparable to a compliant bladder patient.The utility of UBV as a method to monitor changes in bladder wall mechanical properties is validated by the high correlation with pressure measurements in ex vivo and in vivo patient studies. High correlation UBV and UDS in vivo studies demonstrated the potential of UBV as a bladder compliance assessment tool. Results of studies on healthy volunteers with normal bladders demonstrated that UBV could be performed noninvasively. Further studies on a larger cohort are needed to fully validate the use of UBV as a clinical tool for bladder compliance assessment.

  7. The infinite well and Dirac delta function potentials as pedagogical, mathematical and physical models in quantum mechanics

    Science.gov (United States)

    Belloni, M.; Robinett, R. W.

    2014-07-01

    The infinite square well and the attractive Dirac delta function potentials are arguably two of the most widely used models of one-dimensional bound-state systems in quantum mechanics. These models frequently appear in the research literature and are staples in the teaching of quantum theory on all levels. We review the history, mathematical properties, and visualization of these models, their many variations, and their applications to physical systems. quote>For the ISW and the attractive DDF potentials, Eq. (4) implies, as expected, that energy eigenfunctions will have a kink-a discontinuous first derivative at the location of the infinite jump(s) in the potentials. However, the large |p| behavior of the momentum-space energy eigenfunction given by Eq. (5) will be |ϕ(p)|∝1/p2. Therefore for the ISW and the attractive DDF potentials, expectation value of p will be finite, but even powers of p higher than 2 will not lead to convergent integrals. This analysis proves that despite the kinks in the ISW and attractive DDF eigenfunctions, is finite, and therefore yield appropriate solutions to the Schrödinger equation.The existence of power-law ‘tails’ of a momentum distribution as indicated in Eq. (5) in the case of ‘less than perfect’ potentials [41], including a 1/p2 power-law dependence for a singular potential (such as the DDF form) may seem a mathematical artifact, but we note two explicit realizations of exactly this type of behavior in well-studied quantum systems.As noted below (in Section 6.2) the momentum-space energy eigenfunction of the ground state of one of the most familiar (and singular) potentials, namely that of the Coulomb problem, is given by ϕ1,0,0(p)=√{8p0/π}p0/2 where p0=ħ/a0 with a0 the Bohr radius. This prediction for the p-dependence of the hydrogen ground state momentum-space distribution was verified by Weigold [42] and collaborators with measurements taken out to p-values beyond 1.4p0; well out onto the power-law

  8. Mechanical

    Directory of Open Access Journals (Sweden)

    Maha R. Mohamed

    2013-08-01

    Full Text Available Various pozzolanic cement pastes based on ordinary Portland cement (OPC, granulated blast furnace slag (GBFS and metakaolin (MK were studied. Mixes were prepared using a water/solid ratio (W/S of 0.25 wt.%. Hydration characteristics of the different hardened cement pastes were investigated via the examination of chemically-combined water content, compressive strength, and X-ray diffraction analysis under normal curing conditions at various time intervals up to 90 days. Thermal analysis (DTA/TGA was carried out for the mix containing 30% Mk and GBFS at 28 days. The electrical conductivity was measured during the early stages of hydration for the various cement pastes at 30 °C. Moreover, the corrosion potential of reinforced steel embedded in the metakaolin–slag–cement system was studied in comparison to their corresponding ordinary Portland cement, to evaluate the probability of steel corrosion. The results showed that the values of Wn% in these blended pastes are higher than blended pastes with slag or metakaolin only. Also, mix containing 70% OPC, 15% Mk and 15% GBFS has higher compressive strength and corrosion resistance than the net cement paste. The results of thermal analysis indicate that the presence of 30% GBFS and MK consumed the CH formed as a result of the hydration of OPC (pozzolanic reaction.

  9. Acute failure of action potential conduction in mdx muscle reveals new mechanism of contraction-induced force loss

    Science.gov (United States)

    Call, Jarrod A; Warren, Gordon L; Verma, Mayank; Lowe, Dawn A

    2013-01-01

    A primary feature of skeletal muscle lacking the protein dystrophin, as occurring in Duchenne muscular dystrophy, is a hypersensitivity to contraction-induced strength loss. We tested the hypothesis that the extensive strength loss results from an impairment in the electrophysiological function of the plasmalemma specifically impaired action potential development. Anterior crural muscles from mdx and wildtype mice performed a single bout of 100 electrically stimulated eccentric contractions in vivo. Electromyography, specifically the M-wave, was analysed during muscle contraction to assess the ability of the tibialis anterior muscle plasmalemma to generate and conduct action potentials. During eccentric contractions, wildtype mice exhibited a 36% loss in torque about the ankle but mdx mice exhibited a greater torque loss of 73% (P eccentric contractions. These findings (i) suggest a major plasmalemma-based mechanism of strength loss underlying contraction-induced injury in Duchenne muscular dystrophy distinctly different from that for healthy muscle, and (ii) demonstrate dystrophin is critical for maintaining action potential generation and conduction after eccentric contractions. PMID:23753524

  10. Entropic potential field formed for a linear-motor protein near a filament: Statistical-mechanical analyses using simple models

    Science.gov (United States)

    Amano, Ken-ichi; Yoshidome, Takashi; Iwaki, Mitsuhiro; Suzuki, Makoto; Kinoshita, Masahiro

    2010-07-01

    We report a new progress in elucidating the mechanism of the unidirectional movement of a linear-motor protein (e.g., myosin) along a filament (e.g., F-actin). The basic concept emphasized here is that a potential field is entropically formed for the protein on the filament immersed in solvent due to the effect of the translational displacement of solvent molecules. The entropic potential field is strongly dependent on geometric features of the protein and the filament, their overall shapes as well as details of the polyatomic structures. The features and the corresponding field are judiciously adjusted by the binding of adenosine triphosphate (ATP) to the protein, hydrolysis of ATP into adenosine diphosphate (ADP)+Pi, and release of Pi and ADP. As the first step, we propose the following physical picture: The potential field formed along the filament for the protein without the binding of ATP or ADP+Pi to it is largely different from that for the protein with the binding, and the directed movement is realized by repeated switches from one of the fields to the other. To illustrate the picture, we analyze the spatial distribution of the entropic potential between a large solute and a large body using the three-dimensional integral equation theory. The solute is modeled as a large hard sphere. Two model filaments are considered as the body: model 1 is a set of one-dimensionally connected large hard spheres and model 2 is a double helical structure formed by two sets of connected large hard spheres. The solute and the filament are immersed in small hard spheres forming the solvent. The major findings are as follows. The solute is strongly confined within a narrow space in contact with the filament. Within the space there are locations with sharply deep local potential minima along the filament, and the distance between two adjacent locations is equal to the diameter of the large spheres constituting the filament. The potential minima form a ringlike domain in model 1

  11. Modulation of vitellogenin synthesis through estrogen receptor beta-1 in goldfish (Carassius auratus) juveniles exposed to 17-β estradiol and nonylphenol

    International Nuclear Information System (INIS)

    Soverchia, L.; Ruggeri, B.; Palermo, F.; Mosconi, G.; Cardinaletti, G.; Scortichini, G.; Gatti, G.; Polzonetti-Magni, A.M.

    2005-01-01

    Many synthetic chemicals, termed xenoestrogens, have been shown to interact as agonists with the estrogen receptor (ER) to elicit biological responses similar to those of natural hormones. To date, the regulation of vitellogenesis in oviparous vertebrates has been widely used for evaluation of estrogenic effects. Therefore, Carassius auratus juveniles were chosen as a fish model for studying the effects of estradiol-17β and different concentrations (10 -6 and 10 -7 M) of 4-nonylphenol (4-NP) on the expression of liver ERβ-1 subtype; plasma vitellogenin and sex steroids (androgens and estradiol-17β) were also evaluated together with the bioaccumulation process, through mass-spectrometry. C. auratus is a species widespread in the aquatic environment and, on the toxicological point of view, can be considered a good 'sentinel' species. Juveniles of goldfish were maintained in tanks with only tap water or water with different concentrations (10 -6 and 10 -7 M) of 4-nonylphenol (4-NP), or 10 -7 M of estradiol-17β. After 3 weeks of treatment, animals were anesthetized within 5 min after capture, and blood was immediately collected into heparinized syringes by cardiac puncture and stored at -70 deg. C; the gonads were fixed, then frozen and stored at -70 deg. C; the whole fish, liver, and muscle tissues were harvested and immediately stored at -70 deg. C for molecular biology experiments and bioaccumulation measurements. The estrogenic effects of 4-NP were evidenced by the presence of plasma vitellogenin in juveniles exposed both to estradiol-17β and the two doses of 4-NP; moreover, exposure to 4-NP also increased aromatization of androgens, as suggested by decreasing androgens and increasing estradiol-17β plasma levels. The changes of these parameters were in agreement with the increasing transcriptional rate of ERβ-1 mRNA in the liver, demonstrating that both estradiol-17β and 4-NP modulate the vitellogenin rate through interaction with the ERβ-1 subtype. The

  12. Potential Molecular Mechanisms on the Role of the Sigma-1 Receptor in the Action of Cocaine and Methamphetamine

    Science.gov (United States)

    Yasui, Yuko; Su, Tsung-Ping

    2016-01-01

    The sigma-1 receptor (Sig-1R) is an endoplasmic reticulum membrane protein that involves a wide range of physiological functions. The Sig-1R has been shown to bind psychostimulants including cocaine and methamphetamine (METH) and thus has been implicated in the actions of those psychostimulants. For example, it has been demonstrated that the Sig-1R antagonists mitigate certain behavioral and cellular effects of psychostimulants including hyperactivity and neurotoxicity. Thus, the Sig-1R has become a potential therapeutic target of medication development against drug abuse that differs from traditional monoamine-related strategies. In this review, we will focus on the molecular mechanisms of the Sig-1R and discuss in such a manner with a hope to further understand or unveil unexplored relations between the Sig-1R and the actions of cocaine and METH, particularly in the context of cellular biological relevance. PMID:27088037

  13. Chemical Potential Evaluation of Thermoelectric and Mechanical Properties of Zr2CoZ (Z = Si, Ge) Heusler Alloys

    Science.gov (United States)

    Yousuf, Saleem; Gupta, Dinesh C.

    2018-04-01

    The electronic, mechanical and thermoelectric properties of Zr2CoZ (Z = Si, Ge) Heusler alloys are investigated by the full-potential linearized augmented plane wave method. Using the Voigt-Reuss approximation, we calculated the various elastic constants, the shear and Young's moduli, and Poisson's ratio which predict the ductile nature of the alloys. Thermoelectric coefficients viz., Seebeck, electrical conductivity and figure of merit show Zr2CoZ alloys as n-type thermoelectric materials showing a linearly increasing Seebeck coefficient with temperature mainly because of the existence of almost flat conduction bands along L to D directions of a high symmetry Brillouin zone. The efficiency of conversion was measured as the figure of merit by taking into effect the lattice thermal part that achieves an upper-limit of 0.14 at 1200 K which may favour their use for waste heat recovery at higher temperatures.

  14. Influencing Mechanism of Potential Factors on Passengers’ Long-Distance Travel Mode Choices Based on Structural Equation Modeling

    Directory of Open Access Journals (Sweden)

    Yun Wang

    2017-10-01

    Full Text Available Understanding the public transportation users’ preferences to long-distance travel modes would contribute to reasonable developing policies and resource allocation. This paper aims to explore the influencing mechanism of potential factors on the long-distance travel mode choice. A survey was conducted to collect the data. The analysis of variance (ANOVA approach was applied to analyze the correlation relationship between potential factors and travel mode choice behavior. The results showed that, except gender, service demand for safety and departure time, all of the other factors significantly influenced the travel mode choice behavior. Specifically, passengers with higher education level and income level were more likely to choose high-speed railway (HSR and plane; passengers caring about travel expense were more likely to choose ordinary train, whereas plane and HSR may be chosen more by passengers caring more about comfort, punctuality and efficiency; the more passengers were satisfied with travel modes’ service performance, the more they would be likely to choose them; the most competitive distance ranges for coach, ordinary train, HSR and plane were below 500 km, 500–1000 km, 500–1500 km and over 1500 km, respectively. Besides, the structural equation modeling (SEM technique was applied to investigate the influencing mechanism of factors on the long-distance travel mode choice. The results revealed that travel distance was the most significant variable directly influencing passengers’ mode choices, followed by the service demand, performance evaluation, and personal attributes. Furthermore, personal attributes were verified to have an indirect effect on travel mode choice behavior by significantly affecting the service demand and performance evaluation.

  15. Potential climatic mechanisms associated with the mega drought at 4200 cal yr BP: linking proxy data with modern climate analogues

    Science.gov (United States)

    Carter, V.; Shinker, J. J.

    2017-12-01

    Roughly 4200 years ago, a 150-year long mega drought occurred in the central Rocky Mountains, as indicated by pollen evidence from lake sediments from Long Lake, south-eastern Wyoming. However, pollen evidence does not record the climate mechanisms that caused the drought; they only provide evidence that the drought occurred. A modern climate analogue technique using North American Regional Reanalysis data was applied to the sedimentary data in order to identify possible synoptic and dynamic patterns that may have caused the mega drought at 4200 cal yr BP. Our results suggest warm and dry conditions were a result of anomalously higher-than-normal geopotential heights that were centred over the Great Plains beginning in the spring and persisting through the fall. Drought conditions during the growing seasons was the result of the anomalous high-pressure ridge, which suppressed moisture transport via the low level jet from the Gulf of Mexico, as well as brought in dry continental air from in the interior region of North America. The conditions associated with modern analogues offer a potential climate mechanism that caused the mega drought 4200 years ago, and likely led to the changes in vegetation composition as evidenced by the pollen record from Long Lake, Wyoming.

  16. The impact of cocaine on adult hippocampal neurogenesis: Potential neurobiological mechanisms and contributions to maladaptive cognition in cocaine addiction disorder.

    Science.gov (United States)

    Castilla-Ortega, Estela; Ladrón de Guevara-Miranda, David; Serrano, Antonia; Pavón, Francisco J; Suárez, Juan; Rodríguez de Fonseca, Fernando; Santín, Luis J

    2017-10-01

    After discovering that addictive drugs alter adult neurogenesis, the potential role of adult-born hippocampal neurons in drug addiction has become a promising research field, in which cocaine is the most frequently investigated drug. Although a substantial amount of pre-clinical evidence has accumulated, additional studies are required to reveal the mechanisms by which cocaine modulates adult hippocampal neurogenesis (AHN) and determine whether these adult-born neurons have a role in cocaine-related behaviors, such as cocaine-mediated cognitive symptoms. First, this review will summarize the cocaine-induced alterations in a number of neurobiological factors (neurotransmitters, neurotrophins, glucocorticoids, inflammatory mediators) that likely regulate both hippocampal-dependent learning and adult hippocampal neurogenesis after cocaine exposure. A separate section will provide a detailed review of the available literature that challenges the common view that cocaine reduces adult hippocampal neurogenesis. In fact, cocaine has a short-term anti-proliferative role, but the young adult-born neurons are apparently spared, or even enhanced, following certain cocaine protocols. Thus, we will try to reconcile this evidence with the hippocampal-dependent cognitive symptoms that are typically observed in cocaine addicts, and we will propose new directions for future studies to test the relevant hypothesis. Based on the evidence presented here, the regulation of adult hippocampal neurogenesis might be one of the many mechanisms by which cocaine sculpts hippocampus-dependent learning. Copyright © 2017 Elsevier Inc. All rights reserved.

  17. Chemisorption of estrone in nylon microfiltration membranes: Adsorption mechanism and potential use for estrone removal from water.

    Science.gov (United States)

    Han, Jie; Qiu, Wei; Hu, Jiangyong; Gao, Wei

    2012-03-01

    Estrone is a representative steroid estrogen contaminant that has been detected in effluents from sewage treatment facilities, as well as in surface and ground waters. Our study shows that estrone can be readily removed from water via a unique chemisorption mechanism using nylon microfiltration membranes. Experiments on a laboratory in-line filtration system showed instant removal of estrone from 200 μg/l aqueous solutions by 0.45-μm nylon membranes (ca. 35 L per m(2) membrane). Comparisons with 0.45-μm PVDF, PTFE and glass microfiber membranes suggested that the significant estrone adsorption in nylon membrane should be predominately driven by a different mechanism rather than common physical adsorption. Fourier transform infrared spectroscopy study on nylon membranes and a model compound, N-methylacetamide, showed that the significant adsorption originated from the hydrogen bonding between terminal -OH groups on estrone molecules and nucleophile -C=O groups in amide groups of nylon 6,6. The saturated nylon membrane showed very low leachability in ambient water, while it could be effectively regenerated in alkaline or ethanol solutions. Preliminary reusability study showed that the membrane maintained a consistent adsorption capacity for estrone during ten cycles of reuse. The chemisorption-based polymeric adsorption may provide a new alternative approach for removing estrone and potentially other trace organic contaminants from water. Copyright © 2011 Elsevier Ltd. All rights reserved.

  18. An update on potential molecular mechanisms underlying the actions of snake venom L-amino acid oxidases (LAAOs).

    Science.gov (United States)

    Paloschi, Mauro Valentino; Pontes, Adriana Silva; Soares, Andreimar Martins; Zuliani, Juliana Pavan

    2017-11-08

    LAAOs (EC 1.4.3.2) are found in concentrations that vary according to each species of snakes; Viperidae, Crotalidae and Elapidae contain 1-9% of this enzyme in their venoms. This review focuses on an update on molecular mechanisms, platelet activities, antimicrobial, antiprotozoal, induction of apoptosis and inflammatory potential underlying the actions of SV-LAAOs. Snake venom LAAOs (SV-LAAOs) have become an interesting subject for pharmacological, structural and molecular studies. Although the mechanisms of action of these enzymes are not well understood they are a subject of a variety of studies, because LAAOs are multifunctional enzymes exhibiting a wide range of pharmacological effects, including the inhibition or induction of platelet aggregation, hemolysis and hemorrhage, in addition to the stimulation of apoptosis, the activation of leukocytes and the formation of edema. Moreover, SV-LAAOs play an important role in bactericidal, cytotoxic, anti-parasitic, anti-tumor, and antiviral activities. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

  19. Potential Mechanism of Action of 3′-Demethoxy-6-O-demethyl-isoguaiacin on Methicillin Resistant Staphylococcus aureus

    Directory of Open Access Journals (Sweden)

    Juan Manuel J. Favela-Hernández

    2015-07-01

    Full Text Available Bacterial infections represent one of the main threats to global public health. One of the major causative agents associated with high morbidity and mortality infections in hospitals worldwide is methicillin-resistant Staphylococcus aureus. Therefore, there is a need to develop new antibacterial agents to treat these infections, and natural products are a rich source of them. In previous studies, we reported that lignan 3′-demethoxy-6-O-demethylisoguaiacin, isolated and characterized from Larrea tridentate, showed the best activity towards methicillin-resistant S. aureus. Thus, the aim of this study was to determine the potential molecular mechanism of the antibacterial activity of 3′-demethoxy-6-O-demethylisoguaiacin against methicillin-resistant S. aureus using microarray technology. Results of microarray genome expression were validated by real-time polymerase chain reaction (RT-PCR. The genetic profile expression results showed that lignan 3′-demethoxy-6-O-demethylisoguaiacin had activity on cell membrane affecting proteins of the ATP-binding cassette (ABC transport system causing bacteria death. This molecular mechanism is not present in any antibacterial commercial drug and could be a new target for the development of novel antibacterial agents.

  20. Pipeline integrity management: integration of geotechnical and mechanical assessment to control potential risks due to external forces

    Energy Technology Data Exchange (ETDEWEB)

    Malpartida Moya, John E.; Sota, Giancarlo Massucco de la; Seri, Walter [Compania Operadora de Gas del Amazonas, Lima (Peru)

    2009-07-01

    Every pipeline integrity management system evaluates and controls various threats. On pipelines which have particular characteristics as it is the case of the Andean pipelines and pipelines crossing jungles, one of the main threats are the external forces. Even, this threat causes a greater number of failures than other threats like corrosion or the third part damage. Facing this situation, the pipeline integrity management system of TgP has achieved an important development in the use and suitable handling of the information provided by diverse techniques of pipeline mechanical inspection and geotechnical inspection of the right-of-way (ROW). This document presents our methodology, which interrelate information of the in-line inspection, information of geotechnical inspections of the ROW, instrumentation (Strain Gages), topographic monitoring, among others. All this information is supported in a Geographic Information System (GIS) which allows us to integrate the information. By means of the pipeline integrity management system we control potential risks due to external forces, we have been able to act before events become critical, with no occurrence of failures. This system allows us simultaneously to optimize efforts and preserve the mechanical integrity of our pipelines, not producing neither personal nor environmental nor economical affectation. (author)

  1. Potential Mechanism of Action of 3'-Demethoxy-6-O-demethyl-isoguaiacin on Methicillin Resistant Staphylococcus aureus.

    Science.gov (United States)

    Favela-Hernández, Juan Manuel J; Clemente-Soto, Aldo F; Balderas-Rentería, Isaías; Garza-González, Elvira; Camacho-Corona, María del Rayo

    2015-07-08

    Bacterial infections represent one of the main threats to global public health. One of the major causative agents associated with high morbidity and mortality infections in hospitals worldwide is methicillin-resistant Staphylococcus aureus. Therefore, there is a need to develop new antibacterial agents to treat these infections, and natural products are a rich source of them. In previous studies, we reported that lignan 3'-demethoxy-6-O-demethylisoguaiacin, isolated and characterized from Larrea tridentate, showed the best activity towards methicillin-resistant S. aureus. Thus, the aim of this study was to determine the potential molecular mechanism of the antibacterial activity of 3'-demethoxy-6-O-demethylisoguaiacin against methicillin-resistant S. aureus using microarray technology. Results of microarray genome expression were validated by real-time polymerase chain reaction (RT-PCR). The genetic profile expression results showed that lignan 3'-demethoxy-6-O-demethylisoguaiacin had activity on cell membrane affecting proteins of the ATP-binding cassette (ABC) transport system causing bacteria death. This molecular mechanism is not present in any antibacterial commercial drug and could be a new target for the development of novel antibacterial agents.

  2. Green and gold kiwifruit peel ethanol extracts potentiate pentobarbital-induced sleep in mice via a GABAergic mechanism.

    Science.gov (United States)

    Yang, Hyejin; Lee, Young-Chul; Han, Kyoung-Sik; Singh, Harjinder; Yoon, Minseok; Park, Ji-Hae; Cho, Chang-Won; Cho, Suengmok

    2013-01-01

    Kiwifruit is one of the most popular fruits worldwide, and it has various biological properties, including antioxidant, anti-allergic, and cardiovascular protective effects. The peel of kiwifruit, which is a by-product of processing, is a good source of flavonoids; however, its bioactivity has not been widely investigated. In this study, we evaluated the hypnotic effects of green (GRPE, Actinidia deliciosa) and gold (GOPE, Actinidia chinensis) kiwifruit peel ethanol extracts and their solvent fractions, and the possible underlying mechanisms. Oral GRPE and GOPE administration (125-1000mg/kg) produced a dose-dependent decrease in sleep latency and an increase in sleep duration in pentobarbital-treated mice. Among three different solvent fractions of GRPE and GOPE, ethyl acetate (EA) fractions had the greatest effect on sleep duration at 250mg/kg. The total flavonoid contents of solvent fractions were proportional to sleep duration. Like diazepam (a GABA(A)-benzodiazepine (BZD) receptor agonist), the hypnotic effects of GRPE, GOPE, and their EA fractions were fully inhibited by flumazenil (a GABA(A)-BZD receptor antagonist). These results suggest that potentiation effects of GRPE and GOPE on pentobarbital-induced sleep in mice may be modulated by a GABAergic mechanism. Copyright © 2012 Elsevier Ltd. All rights reserved.

  3. Anti-ulcer effect and potential mechanism of licoflavone by regulating inflammation mediators and amino acid metabolism.

    Science.gov (United States)

    Yang, Yi; Wang, Shuai; Bao, Yong-Rui; Li, Tian-Jiao; Yang, Guan-Lin; Chang, Xin; Meng, Xian-Sheng

    2017-03-06

    Glycyrrhiza is the dry root and rhizome of the leguminous plant, Glycyrrhiza uralensis Fisch., Glycyrrhiza inflata Bat. or Glycyrrhiza glabra L., which was firstly cited in Shennong's Herbal Classic in Han dynasty and was officially listed in the Chinese Pharmacopoeia, has been widely used in China during the past millennia. Licoflavone is the major component of Glycyrrhiza with anti-ulcer activity. The present study is based on clarifying the anti-ulcer effect of licoflavone, aiming at elucidating the possible molecule mechanisms of its action for treating gastric ulcer rats induced by acetic acid. Rats were divided into 7 groups, and drugs were administered from on the day after the onset of gastric ulcer (day 3) until day 11 of the experiment once daily continuously. The plasma were analyzed by high-performance liquid chromatography combined with time-of-flight mass spectrometry (HPLC/ESI-TOF-MS), significant different metabolites were investigated to explain its therapeutic mechanism. Furthermore, quantitative real time polymerase chain reaction (RT-PCR) analysis was performed to detect the expression of RNA in stomach tissue for verifying the above results. Licoflavone can effectively cure the gastric ulcer, particularly the middle dose group. According to the statistical analysis of the plasma different metabolites from each groups and the expression of genes in tissues, sixteen significant different metabolites, including histamine, tryptophan, arachidonic acid, phingosine-1-phosphate etc., contributing to the treatment of gastric ulcer were discovered and identified. In RT-PCR analysis, the results of the expression of RNA were corresponded with what we discovered. Our study indicated licoflavone plays the role of treating gastric ulcer by regulating inflammation mediators and amino acid metabolism. We demonstrated that metabolomics technology combined with gene technology is a useful tool to search different metabolites and to dissect the potential

  4. Effects of triclosan on hormones and reproductive axis in female Yellow River carp (Cyprinus carpio): Potential mechanisms underlying estrogen effect.

    Science.gov (United States)

    Wang, Fan; Guo, Xiangmeng; Chen, Wanguang; Sun, Yaowen; Fan, Chaojie

    2017-12-01

    Triclosan (TCS), a member of the class of compounds called pharmaceutical and personal care products (PPCPs), is a broad antibacterial and antifungal agent found in a lot of consumer products. However, TCS hormone effect mechanism in teleost female fish is not clear. Female Yellow River carp (Cyprinus carpio) were exposed to 1/20, 1/10 and 1/5 LC 50 TCS (96h LC 50 of TCS to carp) under semi-static conditions for 42days. Vitellogenin (Vtg), 17β-estradiol (E 2 ), testosterone(T), estrogen receptor (Er), gonadotropin (GtH), and gonadotropin-releasing hormone (GnRH) levels were measured by enzyme-linked immunosorbent assay (ELISA). Meanwhile, we also examined the mRNA expressions of aromatase, GtHs-β, GnRH, and Er by quantitative real-time PCR (qRT-PCR). The results indicated that 1/5 LC 50 TCS induced Vtg in hepatopancreas of female carps by interference with the hypothalamic-pituitary-gonadal (HPG) axis at multiple potential loci through three mechanisms: (a) TCS exposure enhanced the mRNA expression of hypothalamus and gonadal aromatase which converts androgens into estrogens, subsequently increasing serum concentrations of E 2 to induce Vtg in hepatopancreas; (b) TCS treatment increased GnRH and GtH-β mRNA expression and secretion, causing the disturbance of reproductive endocrine and the increase of E 2 to induce Vtg in hepatopancreas; (c) TCS exposure enhanced synthesis and secretion of Er, then it bound to Er to active Vtg synthesis. These mechanisms showed that TCS may induce Vtg production in female Yellow River carp by Er-mediated and non-Er-mediated pathways. Copyright © 2017 Elsevier Inc. All rights reserved.

  5. The viral transactivator HBx protein exhibits a high potential for regulation via phosphorylation through an evolutionarily conserved mechanism

    Directory of Open Access Journals (Sweden)

    Hernández Sergio

    2012-10-01

    Full Text Available Abstract Background Hepatitis B virus (HBV encodes an oncogenic factor, HBx, which is a multifunctional protein that can induce dysfunctional regulation of signaling pathways, transcription, and cell cycle progression, among other processes, through interactions with target host factors. The subcellular localization of HBx is both cytoplasmic and nuclear. This dynamic distribution of HBx could be essential to the multiple roles of the protein at different stages during HBV infection. Transactivational functions of HBx may be exerted both in the nucleus, via interaction with host DNA-binding proteins, and in the cytoplasm, via signaling pathways. Although there have been many studies describing different pathways altered by HBx, and its innumerable binding partners, the molecular mechanism that regulates its different roles has been difficult to elucidate. Methods In the current study, we took a bioinformatics approach to investigate whether the viral protein HBx might be regulated via phosphorylation by an evolutionarily conserved mechanism. Results We found that the phylogenetically conserved residues Ser25 and Ser41 (both within the negative regulatory domain, and Thr81 (in the transactivation domain are predicted to be phosphorylated. By molecular 3D modeling of HBx, we further show these residues are all predicted to be exposed on the surface of the protein, making them easily accesible to these types of modifications. Furthermore, we have also identified Yin Yang sites that might have the potential to be phosphorylated and O-β-GlcNAc interplay at the same residues. Conclusions Thus, we propose that the different roles of HBx displayed in different subcellular locations might be regulated by an evolutionarily conserved mechanism of posttranslational modification, via phosphorylation.

  6. Mechanisms of the harmful effects of bacterial semen infection on ejaculated human spermatozoa: potential inflammatory markers in semen.

    Science.gov (United States)

    Fraczek, Monika; Kurpisz, Maciej

    2015-01-01

    The invasion of the male reproductive tract by microorganisms, and its subsequent consequences for sperm fertilizing potential, has been intensely discussed. The role of the bacteria that are responsible for the colonization and contamination of the male urogenital tract, rather than its infection, in diminished sperm parameters raises the most controversy. There are numerous premises suggesting that bacterial semen infection is associated with male infertility. However, the molecular mechanism by which the fertility is affected is complex and multifactorial, and still presents a puzzle. Some authors have suggested that direct interactions between bacteria and human spermatozoa facilitate sperm immobilization, affect sperm morphology, and thus weaken the ability of sperm to fertilize. On the other hand, the massive infiltration of activated leukocytes into the inflammatory site may be associated with impairment of sperm fertilizing potential, due to oxidative, apoptotic, and immune processes. This review presents current research trends and aims to summarize the present knowledge of semen inflammation and causative bacterial agents in the male urogenital tract, with its consequence on seminological parameters, and male fertility status.

  7. Microarray profiling analysis of long non-coding RNAs expression in tendinopathy: identification for potential biomarkers and mechanisms.

    Science.gov (United States)

    Zhang, Qiang; Ge, Heng'an; Jiang, Yuqing; Cheng, Biao; Zhou, Dong; Xu, Nanwei

    2015-12-01

    The role of lncRNAs in pathologies of tendinopathy has not been researched so far, this study aims to identify the role and potent mechanism of lncRNAs in tendinopathy with a bioinformatic analysis. The gene profile of GSE26051 based on the platform of Affymetrix Human Genome U133B Array condensed was downloaded from Gene Expression Omnibus. A total of 46 specimens (including 23 normal samples and 23 tendinopathy specimens) were available. Compared with the control samples, differentially expressed genes (DEGs) of tendinopathy was identified the by packages in R. The selected DEGs were further analysed using bioinformatics methods including co-expression and enrichment analysis to detect the potential role of lncRNAs. A total of 40 different expressed lncRNAs were identified. However, most of the identified lncRNAs have not been researched before. And this study only annotate one of the identified lncRNAs successfully, the LOC100507027 (myoregulin), with the potential role in regulating skeletal muscle tissue development and skeletal muscle organ development. © 2016 The Authors. International Journal of Experimental Pathology © 2016 International Journal of Experimental Pathology.

  8. Apoptosis induced by low-intensity ultrasound in vitro: Alteration of protein profile and potential molecular mechanism

    Science.gov (United States)

    Feng, Yi; Wan, Mingxi

    2017-03-01

    To analyze the potential mechanism related to the apoptosis induced by low intensity focused ultrasound, comparative proteomic method was introduced in the study. After ultrasound irradiation (3.0 W/cm2, 1 minute, 6 hours incubation post-irradiation), the human SMMC-7721 hepatocarcinoma cells were stained by trypan blue to detect the morphologic changes, and then the percentage of early apoptosis were tested by the flow cytometry with double staining of FITC-labelled Annexin V/Propidium iodide. Two-dimensional SDS polyacrylamide gel electrophoresis was used to get the protein profile and some proteins differently expressed after ultrasound irradiation were identified by MALDI-TOF mass spectrometry. It's proved early apoptosis of cells were induced by low intentisy focused ultrasound. After ultrasound irradiation, the expressing characteristics of several proteins changed, in which protein p53 and heat shock proteins are associated with apoptosis initiation. It is suggested that the low-intensity ultrasound-induced apoptotic cancer therapy has the potential application via understanding its relevant molecular signaling and key proteins. Moreover, the comparative proteomic method is proved to be useful to supply information about the protein expression to analyze the metabolic processes related to bio-effects of biomedical ultrasound.

  9. Mechanism of ROS scavenging and antioxidant signalling by redox metallic and fullerene nanomaterials: Potential implications in ROS associated degenerative disorders.

    Science.gov (United States)

    Akhtar, Mohd Javed; Ahamed, Maqusood; Alhadlaq, Hisham A; Alshamsan, Aws

    2017-04-01

    The balance between oxidation and anti-oxidation is believed to be critical in maintaining healthy biological systems. However, our endogenous antioxidant defense systems are incomplete without exogenous antioxidants and, therefore, there is a continuous demand for exogenous antioxidants to prevent stress and ageing associated disorders. Nanotechnology has yielded enormous variety of nanomaterials (NMs) of which metallic and carbonic (mainly fullerenes) NMs, with redox property, have been found to be strong scavengers of ROS and antioxidants in preclinical in vitro and in vivo models. Redox activity of metal based NMs and membrane translocation time of fullerene NMs seem to be the major determinants in ROS scavenging potential exhibited by these NMs. A comprehensive knowledge about the effects of ROS scavenging NMs in cellular antioxidant signalling is largely lacking. This review compiles the mechanisms of ROS scavenging as well as antioxidant signalling of the aforementioned metallic and fullerene NMs. Direct interaction between NMs and proteins does greatly affect the corona/adsorption formation dynamics but such interaction does not provide the explanation behind diverse biological outcomes induced by NMs. Indirect interaction, however, that could occur via NMs uptake and dissolution, NMs ROS induction and ROS scavenging property, and NMs membrane translocation time seem to work as a central mode of interaction. The usage of potential antioxidant NMs in biological systems would greatly impact the field of nanomedicine. ROS scavenging NMs hold great promise in the future treatment of ROS related degenerative disorders. Copyright © 2017 Elsevier B.V. All rights reserved.

  10. Mechanisms of Kappa Opioid Receptor Potentiation of Dopamine D2 Receptor Function in Quinpirole-Induced Locomotor Sensitization in Rats

    Science.gov (United States)

    Escobar, Angélica P; González, Marcela P; Meza, Rodrigo C; Noches, Verónica; Henny, Pablo; Gysling, Katia; España, Rodrigo A; Fuentealba, José A

    2017-01-01

    Abstract Background Increased locomotor activity in response to the same stimulus is an index of behavioral sensitization observed in preclinical models of drug addiction and compulsive behaviors. Repeated administration of quinpirole, a D2/D3 dopamine agonist, induces locomotor sensitization. This effect is potentiated and accelerated by co-administration of U69593, a kappa opioid receptor agonist. The mechanism underlying kappa opioid receptor potentiation of quinpirole-induced locomotor sensitization remains to be elucidated. Methods Immunofluorescence anatomical studies were undertaken in mice brain slices and rat presynaptic synaptosomes to reveal kappa opioid receptor and D2R pre- and postsynaptic colocalization in the nucleus accumbens. Tonic and phasic dopamine release in the nucleus accumbens of rats repeatedly treated with U69593 and quinpirole was assessed by microdialysis and fast scan cyclic voltammetry. Results Anatomical data show that kappa opioid receptor and D2R colocalize postsynaptically in medium spiny neurons of the nucleus accumbens and the highest presynaptic colocalization occurs on the same dopamine terminals. Significantly reduced dopamine levels were observed in quinpirole, and U69593-quinpirole treated rats, explaining sensitization of D2R. Presynaptic inhibition induced by kappa opioid receptor and D2R of electrically evoked dopamine release was faster in U69593-quinpirole compared with quinpirole-repeatedly treated rats. Conclusions Pre- and postsynaptic colocalization of kappa opioid receptor and D2R supports a role for kappa opioid receptor potentiating both the D2R inhibitory autoreceptor function and the inhibitory action of D2R on efferent medium spiny neurons. Kappa opioid receptor co-activation accelerates D2R sensitization by contributing to decrease dopamine release in the nucleus accumbens. PMID:28531297

  11. The potential for social contextual and group biases in team decision-making: biases, conditions and psychological mechanisms.

    Science.gov (United States)

    Jones, P E; Roelofsma, P H

    2000-08-01

    This paper provides a critical review of social contextual and group biases that are relevant to team decision-making in command and control situations. Motivated by the insufficient level of attention this area has received, the purpose of the paper is to provide an insight into the potential that these types of biases have to affect the decision-making of such teams. The biases considered are: false consensus, groupthink, group polarization and group escalation of commitment. For each bias the following four questions are addressed. What is the descriptive nature of the bias? What factors induce the bias? What psychological mechanisms underlie the bias? What is the relevance of the bias to command and control teams? The analysis suggests that these biases have a strong potential to affect team decisions. Consistent with the nature of team decision-making in command and control situations, all of the biases considered tend to be associated with those decisions that are important or novel and are promoted by time pressure and high levels of uncertainty. A concept unifying these biases is that of the shared mental model, but whereas false consensus emanates from social projection tendencies, the rest emanate from social influence factors. The authors also discuss the 'tricky' distinction between teams and groups and propose a revised definition for command and control team. Finally, the authors emphasize the need for future empirical research in this area to pay additional attention to the social side of cognition and the potential that social biases have to affect team decision-making.

  12. Effects of melatonin and green-wavelength LED light on the physiological stress and immunity of goldfish, Carassius auratus, exposed to high water temperature.

    Science.gov (United States)

    Jung, Seo Jin; Kim, Na Na; Choi, Young Jae; Choi, Ji Yong; Choi, Young-Ung; Heo, Youn Seong; Choi, Cheol Young

    2016-10-01

    This study investigated the effects of increasing water temperature (22-30 °C) on the physiological stress response and immunity of goldfish, Carassius auratus, and the ability of green light-emitting diode (LED) irradiation or melatonin injections to mitigate this temperature-induced stress. To evaluate the effects of either green-wavelength LED light or melatonin on stress in goldfish, we measured plasma triiodothyronine (T3), thyroxine (T4), and thyroid hormone receptor (TR) mRNA expression; plasma cortisol and glucose; and immunoglobulin M (IgM) and lysozyme mRNA expression. The thyroid hormone activities, TR mRNA expression, and plasma cortisol and glucose were higher in goldfish exposed to high-temperature water, but were lower after exposure to melatonin or green-wavelength LED light. Lysozyme mRNA expression and plasma IgM activity and protein expression were lower after exposure to high water temperatures and higher after melatonin or green-wavelength LED light treatments. Therefore, high water temperature induced stress and decreased immunity; however, green-wavelength LED light and melatonin treatments mitigated the effects of stress and enhanced immunity. The benefits of melatonin decreased with time, whereas those of green-wavelength LED treatment did not.

  13. Yellow fever virus isolated from a fatal post vaccination event: an experimental comparative study with the 17DD vaccine strain in the Syrian hamster (Mesocricetus auratus

    Directory of Open Access Journals (Sweden)

    Sueli Guerreiro Rodrigues

    2004-01-01

    Full Text Available In order to investigate the pathogenicity of the virus strain GOI 4191 that was isolated from a fatal adverse event after yellow fever virus (YFV vaccination, an experimental assay using hamsters (Mesocricetus auratus as animal model and YFV 17DD vaccine strain as virus reference was accomplished. The two virus strains were inoculated by intracerebral, intrahepatic and subcutaneous routes. The levels of viremia, antibody response, and aminotransferases were determined in sera; while virus, antigen and histopathological changes were determined in the viscera. No viremia was detected for either strain following infection; the immune response was demonstrated to be more effective to strain GOI 4191; and no significant aminotransferase levels alterations were detected. Strain GOI 4191 was recovered only from the brain of animals inoculated by the IC route. Viral antigens were detected in liver and brain by immunohistochemical assay. Histothological changes in the viscera were characterized by inflammatory infiltrate, hepatocellular necrosis, and viral encephalitis. Histological alterations and detection of viral antigen were observed in the liver of animals inoculated by the intrahepatic route. These findings were similar for both strains used in the experiment; however, significant differences were observed from those results previously reported for wild type YFV strains.

  14. Development of the leptospirosis by experimental infection in hamsters (Mesocricetus auratus with Leptospira interrogans serovar Canicola, strain LO4, by intact and scratched skin exposures

    Directory of Open Access Journals (Sweden)

    Carolina de Sousa Américo Batista

    2010-10-01

    Full Text Available The establishment and evolution of leptospirosis in hamster (Mesocricetus auratus by experimental infection with Leptospira interrogans serovar Canicola, LO4 strain, by intact and scratched skin exposures, having as control the intraperitoneal route, were evaluated. Hundred-twenty female hamsters distributed in two groups according to inoculation route (intact and scratched skin were used. Infectious inoculum was constituted by a pure culture of L. interrogans serovar Canicola (strain LO4, isolated from liver from a slaughtered swine in Londrina, Paraná state and typified by agglutinins adsortion technique with monoclonal antibody kit at the Royal Tropical Institute, Amsterdam, the Netherlands. The animals were observed twice a day during 21 days. Animals that died were necropsied and kidneys, liver, genital tract (uterus and ovaries and brain were aseptically collected. On the 21st post-inoculation day, surviving animals were euthanized. In these animals, serum samples were also collected by cardiac puncture to antileptospires agglutinins research using microscopic agglutination test (MAT. Fresh direct microscopy and microbiological culture were used for the detection of leptospires. Scratched skin route induced larger lethality when compared to intact skin route, with establishment and evolution of leptospirosis. On the other hand, intact skin route induced renal and/or genital carrier state more frequently. LO4 strain presented low immunogenic power, characterized by soroconversion at the MAT in only one inoculated animal.

  15. Effects of melatonin injection or green-wavelength LED light on the antioxidant system in goldfish (Carassius auratus) during thermal stress.

    Science.gov (United States)

    Jung, Seo Jin; Choi, Young Jae; Kim, Na Na; Choi, Ji Yong; Kim, Bong-Seok; Choi, Cheol Young

    2016-05-01

    We tested the mitigating effects of melatonin injections or irradiation from green-wavelength light-emitting diodes (LEDs) on goldfish (Carassius auratus) exposed to thermal stress (high water temperature, 30 °C). The effects of the two treatments were assessed by measuring the expression and activity levels of the antioxidant enzymes, superoxide dismutase and catalase, plasma hydrogen peroxide, lipid hydroperoxide, and lysozyme. In addition, a comet assay was conducted to confirm that high water temperature damaged nuclear DNA. The expression and activity of the antioxidant enzymes, plasma hydrogen peroxide, and lipid hydroperoxide were significantly higher after exposure to high temperature and were significantly lower in fish that received melatonin or LED light than in those that received no mitigating treatment. Plasma lysozyme was significantly lower after exposure to high temperature and was significantly higher after exposure to melatonin or LED light. The comet assay revealed that thermal stress caused a great deal of damage to nuclear DNA; however, treatment with melatonin or green-wavelength LED light prevented a significant portion of this damage from occurring. These results indicate that, although high temperatures induce oxidative stress and reduce immune system strength in goldfish, both melatonin and green-wavelength LED light inhibit oxidative stress and boost the immune system. LED treatment increased the antioxidant and immune system activity more significantly than did melatonin treatment. Copyright © 2016 Elsevier Ltd. All rights reserved.

  16. CYP27A1 expression in gilthead sea bream (Sparus auratus, L.): effects of calcitriol and parathyroid hormone-related protein.

    Science.gov (United States)

    Bevelander, Gideon S; Pinto, Elsa S L C; Canario, Adelino V M; Spanings, Tom; Flik, Gert

    2008-03-01

    Little is known about vitamin D metabolism in fishes. Several reports have shown hydroxylase activities in various organs to produce vitamin D metabolites, but the enzymes involved have not been isolated or characterized. We isolated and characterized a renal mitochondrial hydroxylase, CYP27A1, that governs vitamin D metabolism in gilthead sea bream, Sparus auratus. The enzyme is highly expressed in kidney and to a far lesser extent in liver. When treated with 25-hydroxy vitamin D or calcitriol, the kidney responded differentially and time dependently with CYP27A1 mRNA expression levels. This response substantiates a role for CYP27A1 in fish vitamin D metabolism. This notion is strengthened by upregulation of CYP27A1 in sea bream treated with parathyroid hormone-related protein (PTHrP), and suggests an original role for PTHrP in calcitriol-regulated processes n fish similar to the role of PTH in mammalian vitamin D-dependent processes.

  17. Are there common mechanisms in sensation seeking and reality distortion in schizophrenia? A study using memory event-related potentials.

    Science.gov (United States)

    Guillem, François; Pampoulova, Tania; Stip, Emmanuel; Todorov, Christo; Lalonde, Pierre

    2005-05-15

    A growing literature suggests that the characteristics of sensation seeking and reality distortion expressed in schizophrenia share several mechanisms. In a previous study, the comparison of patients with high vs. low reality distortion using event-related potentials (ERPs) recorded in a recognition memory task for unfamiliar faces identified neural and cognitive anomalies specifically related to the expression of these symptoms. As a follow-up, this study investigated the ERP correlates of sensation seeking in schizophrenia using the same recognition memory protocol. ERPs have been recorded in controls (N=21) and schizophrenia patients separated into high (HSS; N=13) and low (LSS; N=17) scorers according to Zuckerman's Sensation Seeking Scale. The results show a reduced P2a that was found unrelated to reality distortion in the previous study of reality distortion. It identifies interference inhibition impairment as being specifically related to sensation seeking. On the other hand, HSS scorers display enhanced fronto-central and normal P600 effects also found in high reality distortion patients. These results indicate inappropriate context processing and mnemonic binding common to sensation seeking and reality distortion. LSS scorers also display a reduced temporal N300 similar to that found in low reality distortion patients. This anomaly could reflect the lower reactivity to emotionally significant stimuli that underlies anhedonia symptoms. Finally, the N400 effect and a late frontal effect are found in both HSS and LSS. Since they were unrelated to reality distortion, these indices have been related to basic aspects of schizophrenia, e.g., deficient knowledge integration, or other mechanisms, e.g. anxiety or impulsivity. In summary, the present study examines the strategy of investigating variables, such as temperamental characteristics, in addition to symptoms, to show how discrete impairments may contribute to the expression of the illness.

  18. Metal resistance mechanisms in Gram-negative bacteria and their potential to remove Hg in the presence of other metals.

    Science.gov (United States)

    Giovanella, Patricia; Cabral, Lucélia; Costa, Alexandre Pereira; de Oliveira Camargo, Flávio Anastácio; Gianello, Clesio; Bento, Fátima Menezes

    2017-06-01

    Contamination of the environment by heavy metals has been increasing in recent years due to industrial activities. Thus research involving microorganisms capable of surviving in multi-contaminated environments is extremely important. The objectives of the present study were to evaluate the removal of mercury alone and in the presence of cadmium, nickel and lead by four mercury-resistant microorganisms; estimate the removal of Cd, Ni and Pb; understand the mechanisms involved (reduction, siderophores, biofilms, biosorption and bioaccumulation) in the metal resistance of the isolate Pseudomonas sp. B50D; and determine the capacity of Pseudomonas sp. B50D in removing Hg, Cd, Ni and Pb from an industrial effluent. It was shown that the four isolates evaluated were capable of removing from 62% to 95% of mercury from a culture medium with no addition of other metals. The isolate Pseudomonas sp. B50D showed the best performance in the removal of mercury when evaluated concomitantly with other metals. This isolate was capable of removing 75% of Hg in the presence of Cd and 91% in the presence of Ni and Pb. With respect to the other metals it removed 60%, 15% and 85% of Cd, Ni and Pb, respectively. In tests with effluent, the isolate Pseudomonas sp. B50D removed 85% of Hg but did not remove the other metals. This isolate presented reduction, biosorption, biofilm production and siderophore production as its metal resistance mechanisms. Pseudomonas sp. B50D was thus a candidate with potential for application in the bioremediation of effluents with complex metal contaminations. Copyright © 2017 Elsevier Inc. All rights reserved.

  19. Neurofeedback of slow cortical potentials: neural mechanisms and feasibility of a placebo-controlled design in healthy adults

    Directory of Open Access Journals (Sweden)

    Holger eGevensleben

    2014-12-01

    Full Text Available To elucidate basic mechanisms underlying neurofeedback we investigated neural mechanisms of training of slow cortical potentials by considering EEG- and fMRI. Additionally, we analyzed the feasibility of a double-blind, placebo-con