scholarly journals THE INHIBITORY EFFECT OF ACRIDINE ON THE SPOROGONY OF A COCCIDIUM (EIMERIA STIEDÆ)

1924 ◽  
Vol 40 (2) ◽  
pp. 263-267 ◽  
Author(s):  
Paul A. Lewis
Keyword(s):  
Inhibitory Effect ◽  
Protozoan Parasites ◽  
Other Substances ◽  
Acridine Hydrochloride ◽  
Further Development ◽  
Eimeria Stiedae

The development or ripening of the oocyst of the coccidium of the rabbit is prevented by acridine hydrochloride provided that the cysts are exposed to the action of the chemical before development has started. After sporoblasts are formed acridine does not prevent further development. Many other substances, some of them known to be active against certain protozoan parasites, have no influence on the ripening of the oocysts of the coccidium.

Phagocytic specificity during sexual development in Dictyostelium discoideum

1986 ◽  
Vol 32 (2) ◽  
pp. 79-82 ◽  
Author(s):  
Keith E. Lewis ◽  
Danton H. O'Day
Keyword(s):  
Dictyostelium Discoideum ◽  
Concanavalin A ◽  
Sexual Development ◽  
Wheat Germ ◽  
Giant Cells ◽  
Inhibitory Effect ◽  
Sexual Cycle ◽  
Type I ◽  
Further Development ◽  
Type Receptor

During the sexual cycle of Dictyostelium discoideum, zygote giant cells develop and serve as foci for further development by chemoattracting and cannibalizing hundreds of local amoebae. Previous work has shown that the phagocytic process bears similarities to and differences from asexual endocytosis. In the present study, sexual phagocytosis in D. discoideum was found to be species and developmental stage specific. It was inhibited selectively by glucose and concanavalin A. Although a partial, inhibitory effect of mannose on phagocytosis was not statistically significant, alpha-methylmannosamine, like alpha-methyl-glucose, significantly restored the phagocytic competence of giant cells treated with concanavalin A. Other sugars (N-acetyl glucosamine, N-acetylgalactosamine, and galactose) and lectins (wheat germ agglutinin, Ulex europus type I, and Ricinis communis agglutinin type I) had no significant effect on sexual phagocytosis. Together these data indicate that a glucose-type receptor is involved in selective uptake of D. discoideum amoebae by giant cells.

Prejunctional adrenergic inhibition by aggregating platelets in canine blood vessels

1985 ◽  
Vol 249 (3) ◽  
pp. H685-H689 ◽  
Author(s):  
R. R. Lorenz ◽  
P. M. Vanhoutte
Keyword(s):  
Blood Vessels ◽  
Inhibitory Effect ◽  
Adrenergic Nerve ◽  
Saphenous Veins ◽  
Other Substances ◽  
Adrenergic Nerve Endings ◽  
Adrenergic Neurotransmission ◽  
Prejunctional Inhibition ◽  
Serotonergic Antagonist ◽  
Stimulation Of

Experiments were performed to determine the effect of aggregating platelets on adrenergic neurotransmission. Rings of canine saphenous veins and left circumflex coronary arteries were incubated with [3H]norepinephrine and suspended for superfusion. Aggregating platelets and exogenous 5-hydroxytryptamine decreased the overflow of [3H]norepinephrine evoked by electrical stimulation of the adrenergic nerve endings. The reduction of transmitter overflow caused by 5-hydroxytryptamine was prevented by the serotonergic antagonist methiothepin in a concentration that did not significantly affect the release of 5-hydroxytryptamine or thromboxane B2 from the aggregating platelets. Methiothepin decreased but did not abolish the inhibitory effect of aggregating platelets on neurotransmitter overflow. These experiments demonstrate that 5-hydroxytryptamine and other substances released from aggregating platelets can exert prejunctional inhibition of adrenergic neurotransmission in isolated blood vessels.

scholarly journals Screening and Application of Chitin Synthase Inhibitors

Processes ◽  
2020 ◽  
Vol 8 (9) ◽  
pp. 1029
Author(s):  
Xiaozai Shi ◽  
Shuo Qiu ◽  
Yingling Bao ◽  
Hanchi Chen ◽  
Yuele Lu ◽  
...  
Keyword(s):  
Antifungal Activity ◽  
Inhibitory Concentration ◽  
Inhibitory Effect ◽  
Chitin Synthase ◽  
Fungal Cell ◽  
Ic50 Value ◽  
Further Development ◽  
Fungicide Target ◽  
Better Than

Chitin is an important part of the fungal cell wall, but is not found in plants and mammals, so chitin synthase (CHS) can be a green fungicide target. In this paper, 35 maleimide compounds were designed and synthesized as CHS inhibitors. All the screened compounds showed different degrees of CHS inhibitory activity and antifungal activity in vitro. In particular, the half–inhibitory concentration (IC50) value of compound 20 on CHS was 0.12 mM, and the inhibitory effect was better than that of the control polyoxin B (IC50 = 0.19 mM). At the same time, this compound also showed good antifungal activity and has further development value.

Effect of 2-(4-chlorophenylthio) ethylamine hydrochloride on lycopene biosynthesis in pepper fruits

2020 ◽  
pp. 1-6
Author(s):  
Li Li ◽  
Shi-Lin Tian ◽  
Shi-Lun Xu
Keyword(s):  
Developmental Stages ◽  
Quantitative Polymerase Chain Reaction ◽  
Polymerase Chain Reaction Analysis ◽  
Inhibitory Effect ◽  
Development Stage ◽  
Metabolic Product ◽  
Normal Expression ◽  
Other Substances ◽  
Lycopene Content ◽  
Polymerase Chain

Lycopene is an intermediate metabolic product of the capsanthin biosynthesis pathway in pepper fruits and is one of the strongest antioxidants found in plants. During the ripening of pepper fruits, lycopene is almost completely transformed into the downstream metabolic product capsanthin as well as other substances. As a result, lycopene cannot be enriched in ripe pepper fruits; however, the lycopene content can be increased by 2-(4-chlorophenylthio) ethylamine hydrochloride (CPTA) treatment, using the optimal concentration at the optimal development stage of pepper fruits. The current study tested different CPTA concentrations and fruit developmental stages to increase the lycopene content in pepper fruits. The results showed that the lycopene content was significantly enriched in pepper fruits treated with 0.1% CPTA applied at the turning stage. Real-time quantitative polymerase chain reaction analysis showed that CPTA treatment significantly promoted the expression of the upstream genes (Psy and PDS) involved in the anabolic metabolism of lycopene; however, CPTA treatment had a significant inhibitory effect on the downstream gene (Lcyb) of lycopene synthesis. Therefore, in pepper fruits, CPTA inhibits the normal expression of the Lcyb gene downstream of lycopene, thus achieving notable lycopene enrichment.

scholarly journals Participation of Insulin-Like Growth Factor 1 in Articular Cartilage Remodeling

2021 ◽  
pp. 22-29
Author(s):  
Tatyana Ovcharova ◽  
◽  
Yuliya Zimina ◽  
Pavel Krylov ◽  
◽  
...  
Keyword(s):  
Phylogenetic Analysis ◽  
Growth Factor ◽  
Cartilage Damage ◽  
Cartilage Tissue ◽  
Laboratory Research ◽  
Insulin Like Growth Factor ◽  
Related Organism ◽  
Other Substances ◽  
Long Time ◽  
Further Development

Upon cartilage damage its natural recovery takes a long time. This is due to several reasons: the absence of blood vessels and low metabolic activity. In this regard, it is relevant to study the mechanism of operation of all components involved in the remodeling of cartilage tissue. For this purpose, protein insulin-like growth factor 1 (IGF-1) was taken as an object of research, since one of its main functions is regulation of cell proliferation, which is closely related to the process of cartilage tissue repair. It is known that in recent years, scientific studies have been conducted on the effect of IGF-1 on the remodeling of cartilage tissues, but in combination with other substances that stimulate more active cell regeneration. This review presents the features of the functional properties and protein structure and its main influence on chondrocyte proliferation for further development of accelerated and effective methods of IGF-1 action on cell growth and repair. The phylogenetic analysis of IGF-1 showed the most related organism for human IGF-1 and structural differences of its protein from human, which are inextricably linked with the functional characteristics of each of the organisms. The results of phylogenetic analysis in the future will identify the object for laboratory research in this question and the search for optimal ways to accelerate the process of remodeling of cartilage joints.

scholarly journals Synthesis and Biological Activity Evaluation of Novel 5-Methyl-7-phenyl-3H-thiazolo[4,5-b]pyridin-2-ones

2021 ◽  
Vol 89 (4) ◽  
pp. 52
Author(s):  
Andrii Lozynskyi ◽  
Yulian Konechnyi ◽  
Julia Senkiv ◽  
Ihor Yushyn ◽  
Dmytro Khyluk ◽  
...  
Keyword(s):  
Pathogenic Bacteria ◽  
Antimicrobial Agents ◽  
Inhibitory Effect ◽  
Binding Energies ◽  
Moderate Activity ◽  
Reference Drug ◽  
Potent Inhibitory Effect ◽  
Bacteria And Fungi ◽  
Cytotoxicity Effects ◽  
Further Development

A series of 5-methyl-7-phenyl-3H-thiazolo[4,5-b]pyridin-2-ones has been designed, synthesized, and characterized by spectral data. Target compounds were screened for their antimicrobial activity against some pathogenic bacteria and fungi, and most of them showed moderate activity, especially compound 3g, which displayed the potent inhibitory effect against Pseudomonas aeruginosa and Escherichia coli with MIC value of 0.21 μM. The active thiazolopyridine derivatives 3c, 3f, and 3g were screened for their cytotoxicity effects on HaCat, Balb/c 3T3 cells using MTT assay, which revealed promising results. In silico assessment for compounds 3c, 3f, and 3g also revealed suitable drug-like parameters and ADME properties. The binding interactions of the most active compound 3g were performed through molecular docking against MurD and DNA gyrase, with binding energies and an inhibitory constant compared to the reference drug ciprofloxacin. The tested thiazolo[4,5-b]pyridines constitute an exciting background for the further development of new synthetic antimicrobial agents.

scholarly journals Characterization of Plasmodium Atg3-Atg8 Interaction Inhibitors Identifies Novel Alternative Mechanisms of Action in Toxoplasma gondii

2017 ◽  
Vol 62 (2) ◽  
Author(s):  
Joseph M. Varberg ◽  
Kaice A. LaFavers ◽  
Gustavo Arrizabalaga ◽  
William J. Sullivan
Keyword(s):  
Toxoplasma Gondii ◽  
Drug Targets ◽  
Inhibitory Effect ◽  
Protozoan Parasites ◽  
Conjugation System ◽  
Content Type ◽  
Similar Inhibitory Effect ◽  
High Concentrations

ABSTRACT Protozoan parasites, including the apicomplexan pathogens Plasmodium falciparum (which causes malaria) and Toxoplasma gondii (which causes toxoplasmosis), infect millions of people worldwide and represent major human disease burdens. Despite their prevalence, therapeutic strategies to treat infections caused by these parasites remain limited and are threatened by the emergence of drug resistance, highlighting the need for the identification of novel drug targets. Recently, homologues of the core autophagy proteins, including Atg8 and Atg3, were identified in many protozoan parasites. Importantly, components of the Atg8 conjugation system that facilitate the lipidation of Atg8 are required for both canonical and parasite-specific functions and are essential for parasite viability. Structural characterization of the P. falciparum Atg3-Atg8 (PfAtg3-Atg8) interaction has led to the identification of compounds that block this interaction. Additionally, many of these compounds inhibit P. falciparum growth in vitro, demonstrating the viability of this pathway as a drug target. Given the essential role of the Atg8 lipidation pathway in Toxoplasma, we sought to determine whether three PfAtg3-Atg8 interaction inhibitors identified in the Medicines for Malaria Venture Malaria Box exerted a similar inhibitory effect in Toxoplasma. While all three inhibitors blocked Toxoplasma replication in vitro at submicromolar concentrations, they did not inhibit T. gondii Atg8 (TgAtg8) lipidation. Rather, high concentrations of two of these compounds induced TgAtg8 lipidation and fragmentation of the parasite mitochondrion, similar to the effects seen following starvation and monensin-induced autophagy. Additionally, we report that one of the PfAtg3-Atg8 interaction inhibitors induces Toxoplasma egress and provide evidence that this is mediated by an increase in intracellular calcium in response to drug treatment.

scholarly journals Chern-Simons Topology Geometrics for the generation of the RoccustyrnaTM molecule, a ligand targeting COVID-19-SARS-COV-2 SPIKE D614G binding sites

2020 ◽  
Author(s):  
Ioannis Grigoriadis
Keyword(s):  
Decision Tree ◽  
Quality Data ◽  
Optimum Number ◽  
Active Chemical ◽  
New Chemical Entities ◽  
Other Substances ◽  
Computational Resources ◽  
Further Development ◽  
Chern Simons

Abstract SARS coronavirus 2 (SARS-CoV-2) encoding a SARS-COV-2 SPIKE D614G mutation in the viral spike (S) protein predominate over time in locales where it is found, implying that this change enhances viral transmission. It has also been observed that retroviruses pseudotyped with SG614 infected ACE2-expressing cells markedly more efficiently than those with SD614. The availability of newer modeling techniques, powerful computational resources, and good-quality data have made it possible to generate reliable predictions for new chemical entities, impurities, chemicals, natural products, and a lot of other substances fuelling further development and growth of the field to balance the trade-off between the molecular complexity and the quality of such predictions that cannot be obtained by any other method. In this article, we effectively use a decision tree to obtain an optimum number of small chemical active chemical features from a collection of thousands of them utilizing a shallow neural network and jointly free energy cumulative feature ranking method with decision tree taking both network parameters and input toxicity benchmark features into account. In this paper, we strongly combine methods that are simple in machine learning characteristics, efficient in computing resource usage, and powerful to achieve very high accuracy levels for the in-silico generation of the AI-Quantum designed molecule the RoccustyrnaTM small molecule, a multi-targeting druggable scaffold (1Z)-2‐{((2S,3S,5R)‐5‐ (2‐amino‐6‐oxo‐6,9‐dihydro‐1H‐purin‐9‐yl)‐3‐hydroxyoxolan‐2‐yl)methylidene}‐2‐cyano‐1‐({((2S,4R,5R)‐2‐methyl‐2‐(methylamino)‐1,6‐diazabicyclo(3.2.0)heptan‐4‐yl)oxy}imino)‐1lambda5,2lambda5‐azaphosphiridin‐1‐ylium.targeting the COVID-19-SARS-COV-2 SPIKE D614G mutation using Chern-Simons Topology Euclidean Geometric in a Lindenbaum-Tarski generated QSAR automating modeling and Artificial Intelligence-Driven Predictive Neural Networks.

scholarly journals Peptide Inhibition of Topoisomerase IB from Plasmodium falciparum

2011 ◽  
Vol 2011 ◽  
pp. 1-10 ◽  
Author(s):  
Amit Roy ◽  
Ilda D'Annessa ◽  
Christine J. F. Nielsen ◽  
David Tordrup ◽  
Rune R. Laursen ◽  
...  
Keyword(s):  
Plasmodium Falciparum ◽  
Topoisomerase I ◽  
Mechanistic Explanation ◽  
Inhibitory Effect ◽  
Drug Resistant ◽  
Protozoan Parasites ◽  
New Class ◽  
Topoisomerase Ib ◽  
Essential Enzyme ◽  
Ligation Step

Control of diseases inflicted by protozoan parasites such as Leishmania, Trypanosoma, and Plasmodium, which pose a serious threat to human health worldwide, depends on a rather small number of antiparasite drugs, of which many are toxic and/or inefficient. Moreover, the increasing occurrence of drug-resistant parasites emphasizes the need for new and effective antiprotozoan drugs. In the current study, we describe a synthetic peptide, WRWYCRCK, with inhibitory effect on the essential enzyme topoisomerase I from the malaria-causing parasite Plasmodium falciparum. The peptide inhibits specifically the transition from noncovalent to covalent DNA binding of P. falciparum topoisomerase I, while it does not affect the ligation step of catalysis. A mechanistic explanation for this inhibition is provided by molecular docking analyses. Taken together the presented results suggest that synthetic peptides may represent a new class of potential antiprotozoan drugs.

scholarly journals Study on the Photochemical Reaction Process of 4-methyl-7-Hydroxycoumarin and Its Mechanism by Multi-Spectroscopic Technologies

2021 ◽  
Vol 2112 (1) ◽  
pp. 012023
Author(s):  
Qian Tang ◽  
Zhengping Xian ◽  
Lingjing Li ◽  
Hongyu Cao ◽  
Lihao Wang ◽  
...  
Keyword(s):  
Fluorescence Spectroscopy ◽  
Photochemical Reaction ◽  
Structural Changes ◽  
Blue Shift ◽  
Inhibitory Effect ◽  
Reaction Process ◽  
New Materials ◽  
Characteristic Peak ◽  
Other Substances ◽  
Slight Blue Shift

Abstract The photochemical reaction process of 4-methyl-7-hydroxycoumarin (7H4MC) was studied by UV-Vis spectrometer and fluorescence spectroscopy. The results have shown that the characteristic peak of the UV-Vis spectra at 323 nm of 7H4MC undergoes a significant decrease in absorbance and a slight blue shift when was illuminated; the absorbance of the absorption peak at 279 nm rises, and there is a tendency for new peaks to appear. May be, there are structural changes or new materials generation. The addition of imidazole, VC, 3-indole methanol, GSH and other substances also have different effects on the photochemical reaction of 7H4MC. Among them, only imidazole has a certain inhibitory effect on the process of its photochemical reaction.

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