scholarly journals Effects of Nanosilver Exposure on Cholinesterase Activities, CD41, and CDF/LIF-Like Expression in ZebraFish (Danio rerio) Larvae

2013 ◽  
Vol 2013 ◽  
pp. 1-12 ◽  
Author(s):  
Marzhan Myrzakhanova ◽  
Chiara Gambardella ◽  
Carla Falugi ◽  
Antonietta M. Gatti ◽  
Grazia Tagliafierro ◽  
...  
Keyword(s):  
Immune System ◽  
Acetylcholinesterase Activity ◽  
Whole Body ◽  
Tail Bud ◽  
Risk Of Mortality ◽  
Dependent Inhibition ◽  
Vertebrate Model ◽  
Dose Dependent Inhibition ◽  
20 Nm ◽  
System 1

Metal nanosolicoparticles are suspected to cause diseases in a number of organisms, including man. In this paper, we report the effects of nanosilver (Ag, 1–20 nm particles) on the early development of the zebrafish, a well-established vertebrate model. Embryos at the midgastrula stage were exposed to concentrations ranging from 100 to 0.001 mg/L to verify the effects on different endpoints: lethality, morphology, expression of cholinergic molecules, and development of the immune system. (1) Relative risk of mortality was exponential in the range between 0.001 and 10 mg/L. Exposure to 100 mg/L caused 100% death of embryos before reaching the tail-bud stage. (2) Developmental anomalies were present in the 72 h larvae obtained from embryos exposed to nanosilver: whole body length, decreased eye dimension, and slow response to solicitation by gentle touch with a needle tip, with a significant threshold at 0.1 mg/L. (3) Dose-dependent inhibition of acetylcholinesterase activity was significant among the exposures, except between 1 mg/L and 10 mg/L. (4) The distribution of CD41+ cells and of CDF/LIF-like immunoreactivity was altered according to the Ag concentration. The possible effect of nanosilver in impairing immune system differentiation through the inhibition of molecules related to the cholinergic system is discussed.

scholarly journals Cytosolic free calcium elevation mediates the phagosome-lysosome fusion during phagocytosis in human neutrophils.

1990 ◽  
Vol 110 (5) ◽  
pp. 1555-1564 ◽  
Author(s):  
M E Jaconi ◽  
D P Lew ◽  
J L Carpentier ◽  
K E Magnusson ◽  
M Sjögren ◽  
...  
Keyword(s):  
Median Duration ◽  
Laser Scanning ◽  
Confocal Laser ◽  
Human Neutrophils ◽  
Free Calcium ◽  
Cytosolic Free Calcium ◽  
Dependent Inhibition ◽  
Dose Dependent Inhibition ◽  
20 Nm ◽  
Phagosomal Membrane

Cytosolic free calcium ([Ca2+]i) and fusion of secondary granules with the phagosomal membrane (phagosome-lysosome fusion, P-L fusion) were assessed in single adherent human neutrophils during phagocytosis of C3bi-opsonized yeast particles. Neutrophils were loaded with the fluorescent dye fura2/AM and [Ca2+]i was assessed by dual excitation microfluorimetry. Discharge of lactoferrin, a secondary granule marker into the phagosome was verified by immunostaining using standard epifluorescence, confocal laser scanning and electron microscopy. In Ca2(+)-containing medium, upon contact with a yeast particle, a rapid rise in [Ca2+]i was observed, followed by one or more Ca2+ peaks (maximal value 1,586 nM and median duration 145 s): P-L fusion was detected in 80% of the cells after 5-10 min. In Ca2(+)-free medium the amplitude, frequency and duration of the [Ca2+]i transients were decreased (maximal value 368 nM, mostly one single Ca2+ peak and median duration 75 s): P-L fusion was decreased to 52%. Increasing the cytosolic Ca2+ buffering capacity by loading the cells with MAPT/AM led to a dose-dependent inhibition both of [Ca2+]i elevations and P-L fusion. Under conditions where basal [Ca2+]i was reduced to less than 20 nM and intracellular Ca2+ stores were depleted, P-L fusion was drastically inhibited while the cells ingested yeast particles normally. P-L fusion could be restored in Ca2(+)-buffered cells containing ingested particles by elevating [Ca2+]i with the Ca2(+)-ionophore ionomycin. The present findings directly indicate that although the ingestion step of phagocytosis is a Ca2(+)-independent event, [Ca2+]i transients triggered upon contact with opsonized particles are necessary to control the subsequent fusion of secondary granules with the phagosomal membrane.

Differences between antigenic determinants of pig and cat zona pellucida proteins

Reproduction ◽  
2000 ◽  
pp. 15-23 ◽  
Author(s):  
K Jewgenow ◽  
M Rohleder ◽  
I Wegner
Keyword(s):  
In Vitro Fertilization ◽  
Zona Pellucida ◽  
Antigenic Determinants ◽  
Vitro Fertilization ◽  
Contraceptive Vaccine ◽  
Sperm Binding ◽  
Dependent Inhibition ◽  
Dose Dependent Inhibition ◽  
Dose Dependent

Despite many efforts, the control of reproduction in feral cat populations is still a problem in urban regions around the world. Immunocontraception is a promising approach; thus the present study examined the suitability of the widely used pig zona pellucida proteins (pZP) for contraception in feral domestic cats. Purified zona pellucida proteins obtained from pig and cat ovaries were used to produce highly specific antisera in rabbits. Antibodies against pZP raised in rabbits or lions were not effective inhibitors of either in vitro sperm binding (cat spermatozoa to cat oocytes) or in vitro fertilization in cats, whereas antibodies against feline zona pellucida proteins (fZP) raised in rabbits showed a dose-dependent inhibition of in vitro fertilization. Immunoelectrophoresis, ELISA and immunohistology of ovaries confirmed these results, showing crossreactivity of anti-fZP sera to fZP and to a lesser extent to pZP, but no interaction of anti-pZP sera with fZP. It is concluded that cat and pig zonae pellucidae express a very small number of shared antigenic determinants, making the use of pZP vaccine in cats questionable. A contraceptive vaccine based on feline zona pellucida determinants will be a better choice for the control of reproduction in feral cats if immunogenity can be achieved.

Antioxidant effects and in vitro cytotoxicity on human cancer cell lines of flavonoid-rich Flamboyant (Delonix regia (Bojer) Raf.) flower extract

2020 ◽  
Vol 21 ◽  
Author(s):  
Putthiporn Khongkaew ◽  
Phanphen Wattanaarsakit ◽  
Konstantinos I. Papadopoulos ◽  
Watcharaphong Chaemsawang
Keyword(s):  
Cell Line ◽  
Cell Lines ◽  
Cancer Cell ◽  
Leukemia Cell ◽  
Leukemia Cell Line ◽  
Flower Extract ◽  
Dependent Inhibition ◽  
Dose Dependent Inhibition ◽  
Murine Leukemia Cell ◽  
Dose Dependent

Background: Cancer is a noncommunicable disease with increasing incidence and mortality rates both worldwide and in Thailand. Its apparent lack of effective treatments is posing challenging public health issues. Introduction: Encouraging research results indicating probable anti-cancer properties of the Delonix regia flower extract (DRE) have prompted us to evaluate the feasibility of developing a type of product for future cancer prevention or treatment. Methods and Results: In the present report, using High Performance Liquid Chromatography (HPLC), we demonstrate in the DRE, the presence of high concentrations of three identifiable flavonoids, namely rutin 4.15±0.30 % w/w, isoquercitrin 3.04±0.02 %w/w, and myricetin 2.61±0.01 % w/w respectively while the IC50 of DPPH and ABTS assay antioxidation activity was 66.88±6.30 µg/ml and 53.65±7.24 µg/ml respectively. Discussion: Our cancer cell line studies using the MTT assay demonstrated DREs potent and dose dependent inhibition of murine leukemia cell line (P-388: 35.28±4.07% of cell viability remaining), as well as of human breast adenocarcinoma (MCF-7), human cervical carcinoma (HeLa), human oral cavity carcinoma (KB), and human colon carcinoma (HT-29) cell lines in that order of magnitude. Conclusion: Three identifiable flavonoids (rutin, isoquercitrin and myricetin) with high antioxidation activity and potent and dose dependent inhibition of murine leukemia cell line and five other cancer cell lines were documented in the DRE. The extract’s lack of cytotoxicity in 3 normal cell lines is a rare advantage not usually seen in current antineoplastic agents. Yet another challenge of the DRE was its low dissolution rate and long-term storage stability, issues to be resolved before a future product can be formulated.

Investigation on the antibacterial activity of electronic cigarette liquids (ECLs): a proof of concept study

2020 ◽  
Vol 21 ◽  
Author(s):  
Virginia Fuochi ◽  
Massimo Caruso ◽  
Rosalia Emma ◽  
Aldo Stivala ◽  
Riccardo Polosa ◽  
...  
Keyword(s):  
Antibacterial Activity ◽  
Bacterial Species ◽  
A549 Cells ◽  
Bactericidal Effect ◽  
Minimal Bactericidal Concentration ◽  
Viability Assay ◽  
Dependent Inhibition ◽  
Dose Dependent Inhibition ◽  
Dose Dependent

Background: The key ingredients of e-cigarettes liquid are commonly propane-1,2-diol (also called propylene glycol) and propane-1,2,3-triol (vegetal glycerol) and their antimicrobial effects are already established. The nicotine and flavors which are often present in e-liquids can interfere with the growth of some microorganisms. Objective: The effect of the combining these elements in e-liquids is unknown. The aim of the study was to investigate the possible effects of these liquids on bacterial growth in the presence or absence of nicotine and flavors. Methods: Susceptibilities of pathogenic strains (Klebsiella pneumoniae, Staphylococcus aureus, Pseudomonas aeruginosa, Acinetobacter baumannii, Escherichia coli, Enterococcus faecalis and Sarcina lutea) were studied by means of a multidisciplinary approach. Cell viability and antioxidant assays were also evaluated. Results: All e-liquids investigated showed antibacterial activity against at least one pathogenic strain. A higher activity was correlated to the presence of flavors and nicotine. Discussion: In most cases the value of minimal bactericidal concentration is equal to the value of minimal inhibitory concentration showing that these substances have a bactericidal effect. This effect was observed in concentrations up to 6.25% v/v. Antioxidant activity was also correlated to presence of flavors. Over time, the viability assay in human epithelial lung A549 cells showed a dose-dependent inhibition of cell growth. Conclusion: Our results have shown that flavors considerably enhance the antibacterial activity of propane-1,2-diol and propane-1,2,3-triol. This study provides important evidence that should be taken into consideration in further investigative approaches, to clarify the different sensitivity of the various bacterial species to e-liquids, including the respiratory microbiota, to highlight the possible role of flavors and nicotine.

scholarly journals In VitroActivities of Hexaazatrinaphthylenes against Leishmania spp.

2015 ◽  
Vol 59 (5) ◽  
pp. 2867-2874 ◽  
Author(s):  
Atteneri López-Arencibia ◽  
Daniel García-Velázquez ◽  
Carmen M. Martín-Navarro ◽  
Ines Sifaoui ◽  
María Reyes-Batlle ◽  
...  
Keyword(s):  
Therapeutic Agents ◽  
Content Type ◽  
Inhibition Effect ◽  
Intracellular Amastigotes ◽  
Dependent Inhibition ◽  
Leishmania Spp ◽  
Dose Dependent Inhibition ◽  
Dose Dependent ◽  
Potential Use

ABSTRACTThein vitroactivity of a novel group of compounds, hexaazatrinaphthylene derivatives, against two species ofLeishmaniais described in this study. These compounds showed a significant dose-dependent inhibition effect on the proliferation of the parasites, with 50% inhibitory concentrations (IC50s) ranging from 1.23 to 25.05 μM against the promastigote stage and 0.5 to 0.7 μM against intracellular amastigotes. Also, a cytotoxicity assay was carried out to in order to evaluate the possible toxic effects of these compounds. Moreover, different assays were performed to determine the type of cell death induced after incubation with these compounds. The obtained results highlight the potential use of hexaazatrinaphthylene derivatives againstLeishmaniaspecies, and further studies should be undertaken to establish them as novel leishmanicidal therapeutic agents.

μ-Opiate Receptors in Neuronal Primary Cultures from Cerebral Cortex

1990 ◽  
Vol 17 (3) ◽  
pp. 177-181
Author(s):  
Peter S. Eriksson ◽  
Elisabeth Hansson ◽  
Lars Rönnbäck
Keyword(s):  
Cerebral Cortex ◽  
Primary Cultures ◽  
Opiate Receptors ◽  
Neuronal Cultures ◽  
Camp Accumulation ◽  
Dependent Inhibition ◽  
Dose Dependent Inhibition ◽  
Neuronal Primary Cultures ◽  
Dose Dependent ◽  
Μ Receptor

The presence of μ-opioid receptors was demonstrated as effects of receptor stimulation on PGE1-induced cAMP accumulation in neuronal-enriched primary cultures from rat cerebral cortex. Morphine was used as a μ-receptor agonist. There was a dose-dependent inhibition of the PGE1-stimulated cAMP accumulation by morphine, blocked by the μ-receptor antagonist naloxone. These findings suggest that these neuronal cultures express μ-receptors, possibly connected to adenylate cyclase via an inhibitory Gi-protein. The probable use of functional μ-receptors in neurotoxicological tests is discussed.

EFFECT OF INTRAVENTRICULAR ADMINISTRATION OF NORADRENALINE ON WATER DIURESIS IN GOATS

1975 ◽  
Vol 66 (3) ◽  
pp. 375-383 ◽  
Author(s):  
G. VANDEPUTTE-VAN MESSOM ◽  
G. PEETERS
Keyword(s):  
Intraventricular Administration ◽  
Excretion Ratio ◽  
Dose Response Relationship ◽  
Water Diuresis ◽  
3Rd Ventricle ◽  
Dependent Inhibition ◽  
Dose Dependent Inhibition ◽  
High Doses ◽  
Excretion Rates ◽  
Dose Dependent

SUMMARY During water diuresis in conscious goats, noradrenaline (NA), its antagonists phentolamine, phenoxybenzamine and propranolol and also atropine were administered into the 3rd ventricle. The subsequent effects on water diuresis and on the excretion rates of Na+, K+ and Cl− were investigated. Infusion of NA into the 3rd ventricle induced a strong and significant antidiuretic response and a decrease in the Na+: K+ excretion ratio; these effects were dose-dependent. High doses of NA produced a significant increase in urinary K+ excretion. Similar results were observed after i.v. administration of arginine-vasopressin. Pretreatment with phentolamine injected into the 3rd ventricle produced a dose-dependent inhibition of the NA-induced antidiuretic effects. Phenoxybenzamine also blocked the response to NA but a dose-response relationship was not apparent. Atropine and propranolol did not block the response to NA.

Human kidney 11β-hydroxysteroid dehydrogenase: regulation by adrenocorticotropin?

1996 ◽  
Vol 134 (3) ◽  
pp. 301-307 ◽  
Author(s):  
S Diederich ◽  
M Quinkler ◽  
K Miller ◽  
P Heilmann ◽  
M Schöneshöfer ◽  
...  
Keyword(s):  
Human Kidney ◽  
Kinetic Studies ◽  
Hydroxysteroid Dehydrogenase ◽  
Inhibitory Effect ◽  
Benjamin Franklin ◽  
Dependent Inhibition ◽  
Direct Inhibitory Effect ◽  
Dose Dependent Inhibition ◽  
Endogenous Substrates ◽  
Radioactive Detection

Diederich S, Quinkler M, Miller K, Heilmann P, Schöneshöfer M, Oelkers W. Human kidney 11βhydroxysteroid dehydrogenase: regulation by adrenocorticotropin? Eur J Endocrinol 1996;134:301–7. ISSN 0804–4643 In ectopic adrenocorticotropin (ACTH) syndrome (EAS) with higher ACTH levels than in pituitary Cushing's syndrome and during ACTH infusion, the ratio of cortisol to cortisone in plasma and urine is increased, suggesting inhibition of renal 11β-hydroxysteroid dehydrogenase (11β-HSD) by ACTH or by ACTH-dependent steroids. Measuring the conversion of cortisol to cortisone by human kidney slices under different conditions, we tested the possibility of 11β-HSD regulation by ACTH and corticosteroids. Slices prepared from unaffected parts of kidneys removed because of renal cell carcinoma were incubated with unlabeled or labeled cortisol, and cortisol and cortisone were quantitated after HPLC separation by UV or radioactive detection. The 11β-HSD activity was not influenced by incubation with increasing concentrations (10−12–10−9 mol/l) of ACTH (1–24 or 1–39) for 1 h. Among 12 ACTH-dependent steroids tested (10−9–10−6 mol/l), only corticosterone (IC50 = 2 × 10−7 mol/l), 18-OH-corticosterone and 11βOH-androstenedione showed a significant dose-dependent inhibition of 11β-HSD activity. The percentage conversion rate of cortisol to cortisone was concentration dependent over the whole range of cortisol concentrations tested (10−8–10−5 mol/l). A direct inhibitory effect of ACTH on 11β-HSD is, therefore, unlikely. The only steroids inhibiting the conversion of cortisol to cortisone are natural substrates for 11β-HSD Kinetic studies show a saturation of the enzyme at high cortisol concentrations. Thus, the reduced percentage renal cortisol inactivation in EAS seems to be due mainly to overload of the enzyme with endogenous substrates (cortisol, corticosterone and others) rather than to direct inhibition of 11β-HSD by ACTH or ACTHdependent steroids, not being substrates of 11β-HSD. S Diederich, Department of Endocrinology, Klinikum Benjamin Franklin, Freie Universität Berlin, Hindenburgdamm 30, 12200 Berlin, Germany

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