Effects of macrocyclic lactone anthelmintics on feeding and pharyngeal pumping in Trichostrongylus colubriformis in vitro

Parasitology ◽  
2002 ◽  
Vol 125 (5) ◽  
pp. 477-484 ◽  
Author(s):  
J. C. SHERIFF ◽  
A. C. KOTZE ◽  
N. C. SANGSTER ◽  
R. J. MARTIN
Keyword(s):  
Electrical Activity ◽  
Macrocyclic Lactone ◽  
Inhibitory Effect ◽  
Drug Uptake ◽  
Trichostrongylus Colubriformis ◽  
Pump Frequency ◽  
Pharyngeal Pumping ◽  
The Difference ◽  
Relative Potencies

The effects of macrocyclic lactone anthelmintics (MLs) on feeding by Trichostrongylus colubriformis nematodes in vitro were examined using inulin uptake as a measure of ingestion and electropharyngeograms as a record of the electrical events associated with pharyngeal pumping. Inulin uptake was inhibited by the 4 MLs tested (EC50s 0.045–4.57 nM), with an order of potency of eprinomectin (most potent), ivermectin, ivermectin monosaccharide, and ivermectin aglycone. The MLs caused both the frequency and amplitude of pharyngeal electrical events to decrease. In individual worms the inhibition of pump frequency preceded the inhibition of pump amplitude. The order of potency of the MLs as inhibitors of frequency was ivermectin aglycone, ivermectin, ivermectin monosaccharide and eprinomectin. The difference compared with the inulin assay results are probably due to the dynamics of drug uptake in the two systems. It was possible that the nematodes in the electrophysiology experiments were effectively orally ligated by enclosure of the worm's head in the recording pipette which contained no drug. Despite this difference in relative potencies, both the ingestion assays and the electrical events indicate that MLs are potent inhibitors of the pharynx in T. colubriformis in vitro. The sequence of effects on pharyngeal electrical activity suggests that ML action involves an initial inhibitory effect on the rate of pharyngeal contractions, followed by a decrease in the amplitude of the potentials associated with pharyngeal pumping events.

Macrophages in Skin Cancer: Quantitative and Functional Studies

1979 ◽  
Vol 65 (3) ◽  
pp. 309-316 ◽  
Author(s):  
Franco Dammacco ◽  
Antonio Miglietta ◽  
Mario Lospalluti ◽  
Carlo Meneghini ◽  
Lorenzo Bonomo
Keyword(s):  
Skin Cancer ◽  
Surgical Excision ◽  
Inhibitory Effect ◽  
Average Percentage ◽  
Functional Studies ◽  
Macrophage Chemotaxis ◽  
Primary Neoplasm ◽  
The Difference

The number of tumor-infiltrating macrophages was estimated in 43 patients with skin cancer, including 18 cases of squamous cell and 25 cases of basal cell carcinoma. Macrophages were identified in cell cultures by 2 assays, namely phagocytosis and resistance to detachment by trypsin. The average percentage of adherent cells for the 2 groups of skin tumors was 4.5 ± 2.6 and 10.2 ± 5.2, respectively, and the difference was statistically significant. Follow-up studies after surgical excision of the primary neoplasm showed a relatively low macrophage content in 2 of the 4 cases in which local recurrences occurred. Preliminary functional studies suggested that soluble factors may be released by neoplastic cells, accounting for the inhibitory effect of tumor cell supernatants on macrophage Chemotaxis in vitro.

scholarly journals Changes in the Density and Composition of Rhizosphere Pathogenic Fusarium and Beneficial Trichoderma Contributing to Reduced Root Rot of Intercropped Soybean

2021 ◽  
Author(s):  
Xiaoli Chang ◽  
Huiting Xu ◽  
Li Yan ◽  
Dan Zhu ◽  
Wei Wang ◽  
...  
Keyword(s):  
Root Rot ◽  
Cell Walls ◽  
Rhizosphere Soil ◽  
Fusarium Species ◽  
Inhibitory Effect ◽  
Trichoderma Species ◽  
Soybean Root ◽  
The Difference ◽  
Rhizosphere Microbial Community

Abstract BackgroundThe dynamic of soil-borne disease is closely related to the rhizosphere microbial communities. Maize-soybean intercropping can suppress soybean root rot as compared to monoculture. However, it is still unknown whether rhizosphere microbial community participates in the regulation of intercropped soybean root rot.MethodsIn this study, the difference of rhizosphere Fusarium and Trichoderma community was compared between healthy or root-rotted soybean rhizosphere soil from soybean monoculture and maize-soybean intercropping, and the inhibitory effect of potential biocontrol Trichoderma against pathogenic Fusarium were examined.ResultsThe abundance of rhizosphere Fusarium was remarkably different between intercropping and monoculture, while Trichoderma was largely accumulated in healthy rhizosphere soil of intercropping rather than monoculture. Four rhizosphere Fusarium species identified were all pathogenic to soybean but displayed distinct composition and isolation proportion in the corresponding soil types. As the dominant and most aggressive species, F. oxysporum was more frequently isolated in diseased soil of monoculture. Furthermore, of three Trichoderma species identified, T. harzianum dramatically increased in the rhizosphere of intercropping rather than monoculture as compared to T. virens and T. afroharzianum. For in-vitro antagonism test, Trichoderma strains had antagonistic effects on F. oxysporum with the percentage of mycelial inhibition ranging of 50.59%-92.94%, and they displayed good mycoparasitic abilities against F. oxysporum through coiling around and entering into the hyphae, expanding along cell-cell lumen and even dissolving cell walls of target fungus.ConclusionThese results indicate maize-soybean intercropping significantly increase the density and composition proportion of beneficial Trichoderma to antagonist the pathogenic Fusarium species, thus contributing to the suppression of soybean root rot under intercropping.

scholarly journals Antibodies that protect humans against Plasmodium falciparum blood stages do not on their own inhibit parasite growth and invasion in vitro, but act in cooperation with monocytes.

1990 ◽  
Vol 172 (6) ◽  
pp. 1633-1641 ◽  
Author(s):  
H Bouharoun-Tayoun ◽  
P Attanath ◽  
A Sabchareon ◽  
T Chongsuphajaisiddhi ◽  
P Druilhe
Keyword(s):  
Plasmodium Falciparum ◽  
Inhibitory Effect ◽  
Parasite Growth ◽  
Normal Blood ◽  
Blood Monocytes ◽  
Western Blots ◽  
The Difference

IgG extracted from the sera of African adults immune to malaria were injected intravenously into eight Plasmodium falciparum-infected nonimmune Thai patients. Clinical and parasitological improvement was reproducibly obtained in each case. After the disappearance of the transferred Ig, recrudescent parasites were equally susceptible to the same Ig preparation. High levels of antibodies to most parasite proteins were detected by Western blots in the receivers' sera (taken before transfer) as in the donors' Ig, thus indicating that the difference was qualitative rather than quantitative between donors and receivers. In vitro, the clinically effective Ig had no detectable inhibitory effect on either penetration or intra-erythrocytic development of the parasite. On the contrary, they sometimes increased parasite growth. In contrast, these IgG, as the receivers' Ig collected 4 d after transfer, but not those collected before transfer, proved able to exert an antibody-dependent cellular inhibitory (ADCI) effect in cooperation with normal blood monocytes. Results were consistent among the seven isolates studied in vitro, as with the recrudescent parasites. Thus, the results obtained in the ADCI assay correlate closely with clinical and parasitological observations.

Inhibitory Effect of Sodium Pumping on Spontaneous Contractility of Rabbit Myometrium

1974 ◽  
Vol 52 (4) ◽  
pp. 786-790 ◽  
Author(s):  
Anthony Johns ◽  
David M. Paton
Keyword(s):  
Isometric Force ◽  
Inhibitory Effect ◽  
Mechanical Activity ◽  
Free Medium ◽  
Membrane Hyperpolarization ◽  
Sodium Pumping ◽  
Displacement Transducers ◽  
Force Displacement ◽  
Relative Potencies

The effects of K+ and related cations on the spontaneous contractility of estrogen-dominated rabbit myometrial strips were examined in vitro with isometric force-displacement transducers. Addition of 5–40 mM KCl, RbCl, or CsCl caused increased contractility of strips in medium containing 5.4 mM K+. Removal of K+ from the medium generally increased contractility. Addition of KCl, RbCl, CsCl, or LiCl to strips in K+-free medium caused an immediate rapid inhibition of contractility, the relative potencies being K+ = Rb+ > Cs+ > Li+. This effect was produced by 0.25–40 mM KCl or RbCl and was inhibited by 10−5 M ouabain. It was concluded that addition of K+, Rb+, Cs+, or Li+ to tissues in K+-free medium probably activated electrogenic Na+ pumping with resultant membrane hyperpolarization and inhibition of mechanical activity.

Inhibitory Effect of Polyionic Compounds on the Adsorption of Herpes Simplex Virus Type 1 (KOS)

1997 ◽  
Vol 8 (1) ◽  
pp. 32-37 ◽  
Author(s):  
Y-W Yang ◽  
J-C Yang
Keyword(s):  
Molecular Weight ◽  
Herpes Simplex Virus ◽  
Herpes Simplex ◽  
Vero Cells ◽  
Cellular Membrane ◽  
Inhibitory Effect ◽  
The Difference ◽  
Simplex Virus ◽  
Hsv 1

The polyionic compounds, including dextran sulphates and poly-L-lysines, were evaluated for their inhibitory effect on the cytopathic effect of herpes simplex virus (HSV-1, KOS) in vitro. The anti-HSV activities of poly-L-lysines were found to increase with increasing molecular weight of the polymers. Both dextran sulphates and poly-L-lysines were found to block adsorption of HSV-1 to Vero cells. The inhibitory effect of adsorption of [3H] labelled virus was related to the molecular weight of the polymers. Polymers of higher molecular weight were found to be more effective than the lower molecular weight samples in inhibiting virus adsorption. The results from the microelectrophoresis measurements demonstrated that poly-L-lysines adsorb and confer positive charges on the Vero cells. Dextran sulphates, on the other hand, may adsorb onto the HSV-1 membrane surfaces instead of binding onto the cell membranes and interfere with adsorption of virions to the cells. The inhibitory effects of these polymers on viral cytopathogenic effect were probably attributable to the electrostatic and steric hindrance effects exerted by the polymers as reflected in the difference in zeta potential of cellular membrane treated with these compounds.

scholarly journals THE INFLUENCE OF COLLOIDS UPON THE DIFFUSION OF HÆMOLYSINS

1906 ◽  
Vol 8 (4) ◽  
pp. 547-563 ◽  
Author(s):  
Simon Flexner ◽  
Hideyo Noguchi
Keyword(s):  
Salt Solution ◽  
Inhibitory Effect ◽  
The Body ◽  
Toxic Chemicals ◽  
Toxic Substances ◽  
Square Root ◽  
Living Body ◽  
Fluid Media ◽  
The Difference

Acids, alkalies, salts, glucosides, and certain toxins diffuse more quickly into 0.9 per cent. salt solution than into agar-agar and gelatin suspensions. The inhibitory effect of the colloids grows with increase in concentration, which increase affects both the velocity and extent of the diffusion. In the case of gelatin the degree of diffusion is approximately in inverse proportion to the square root of the concentration. Agar-agar in strengths up to 2 per cent. inhibits far less than gelatin in 10 per cent. suspensions; and the difference in degree of inhibition exercised by 0.5 per cent. and 2 per cent. agar-agar is a small one. Hæmolytic substances diffuse from gelatin into agar-agar more slowly than from saline into agar-agar. But the velocity of diffusion from agar-agar into gelatin is greater than from saline into gelatin. The effects of differences in concentration of the hæmolytic agent vary according to the agent and the manner of its solution. When the hæmolyser is dissolved in salt solution the diffusion of 1/100 N. and 1/1000 N. solutions (saponin) is almost identical; while with solanin the stronger solutions diffuse faster. When the hæmolyser is dissolved in the colloid diffusion into fluid media is nearly proportional to the concentrations of the hæmolytic agent. The velocity of diffusion into and from colloids is in general proportional to the square root of the time. Acids, alkalies, salts, and glucosides act in a manner which is in agreement with this rule. Cobra lysin and tetanolysin do not act in conformity with the rule. Cobra lysin appears to diffuse into colloids more slowly, proportionally, than cobra neurotoxin, and tetanospasmin more slowly than tetanolysin. The biological method described in this paper for studying diffusion in colloids is applicable to hæmolytic and some other toxic substances, and, with accuracy possibly only to such substances possessing relatively simple compositions. Since all diffusion in the living body takes place within colloidal media of different concentrations, it would seem desirable to perfect methods through which the interaction of toxic chemicals and the fluids and cells of the body may in a manner be imitated in vitro. Through this means our knowledge of toxicology may well be extended.

Fabrication of Calcium Sulfate Coated Selenium Nanoparticles and Corresponding In-Vitro Cytotoxicity Effects Against 4T1 Breast Cancer Cell Line

2021 ◽  
Author(s):  
Elnaz Faghfuri ◽  
Ramak Ajideh ◽  
Faranak Shahverdi ◽  
Mina Hosseini ◽  
Faranak Mavandadnejad ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Cancer Cells ◽  
Calcium Sulfate ◽  
Cancer Cell Line ◽  
Inhibitory Effect ◽  
In Vitro Cytotoxicity ◽  
Selenium Nanoparticles ◽  
The Difference ◽  
Cytotoxicity Effects

Background: The inhibitory effect of selenium nanoparticles (SeNPs) on cancer cells has been reported in many studies. In this study, the purpose was to compare the in vitro effects of SeNPs and calcium sulfate coated selenium nanoparticles (CaSO4@ SeNPs) on breast cancer cells. Methods: CaSO4@SeNPs and SeNPs were chemically synthesized and characterized with Field Emission Scanning Electron Microscope (FESEM) and energy-dispersive X-ray spectroscopy (EDX). By applying MTT assay, the cytotoxicity effect of both nanomaterials on the 4T1 cancer cells was investigated. Results: While LD50 of SeNPs on 4T1 cancer cells was 80 µg, the LD50 of CaSO4@SeNPs was reported to be only 15 µg. The difference between the inhibition rates obtained for SeNPs and CaSO4@SeNPs was statistically significant (p=0.05). In addition, at higher concentrations (50 µg) of CaSO4@SeNPs, the cytotoxicity was 100% more than SeNPs alone.   Conclusion: According to the result of the present work, it can be concluded that de-coration of SeNPs with calcium sulfate leads to an increase in potency by decreasing the effective dose. This effect can be attributed to activation of intrinsic apoptosis signaling and/or pH regulatory properties of CaSO4@SeNPs. However, further studies are still needed to determine the exact corresponding mechanisms of this synergistic effect.

Yangambin Cytotoxicity: A Pharmacologically Active Lignan Obtained from Ocotea duckei Vattimo (Lauraceae)

2008 ◽  
Vol 63 (9-10) ◽  
pp. 681-686 ◽  
Author(s):  
Rubens L. Monte Neto ◽  
M. A. Sousa ◽  
Celidarque S. Dias ◽  
José M. Barbosa Filho ◽  
Márcia R. Oliveira
Keyword(s):  
Trypan Blue ◽  
Inhibitory Effect ◽  
In Vitro Models ◽  
In Vitro Cytotoxicity ◽  
Blue Dye ◽  
Reduction Assay ◽  
Mtt Reduction ◽  
The Difference ◽  
Pharmacologically Active

The in vitro cytotoxic potential of yangambin was evaluated. Yangambin is a pharmacologically active furofuran lignan obtained from the leaves of Ocotea duckei. It is the major compound from the lignoids fraction. Yangambin presented low cytotoxicity in all in vitro models analyzed. Its cytotoxicity to murine macrophages was measured by the Trypan blue dye exclusion test and MTT reduction assay, resulting in high CC50 values of 187.0 μg/mL (383.3 μm) and 246.7 μg/mL (504.3 μm), respectively. The difference obtained in the inhibitory concentrations aforementioned can be explained, at least in part, by the different principles of the methods. While the MTT reduction assay evaluates the ability of yangambin to inhibit the activity of the mitochondrial enzyme succinate dehydrogenase, the Trypan blue dye exclusion test evaluates possible damages to the integrity of the cytoplasmic membrane which result in cell death. The capacity of yangambin to inhibit the sea urchin embryonic development showed that it has low antimitotic and teratogenic potential, once continued exposure of embryos to concentrations up to 500 μg/mL (1.025 μm) did not result in an inhibitory effect on the first egg cleavages. Such low in vitro cytotoxicity is correlated with the low acute toxicity previously studied. All these data, together with the various therapeutic properties of yangambin, make this lignan a promising one for a new drug.

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