Specific Interaction Between Damaged Bases in DNA and Repair Enzymes

1999 ◽  
pp. 127-138
Author(s):  
Kosuke Morikawa
Keyword(s):  
Specific Interaction ◽  
Repair Enzymes

Heparin Counteracts the Antiaggregating Effect of Prostacyclin by Potentiating Platelet Aggregation

1983 ◽  
Vol 49 (02) ◽  
pp. 081-083 ◽  
Author(s):  
Vittorio Bertelé ◽  
Maria Carla Roncaglioni ◽  
Maria Benedetta Donati ◽  
Giovanni de Gaetano
Keyword(s):  
Platelet Aggregation ◽  
Human Platelet ◽  
Specific Interaction ◽  
Inhibitory Effect ◽  
Effective Inhibitor ◽  
Inhibitory Potency ◽  
Human Platelet Aggregation

SummaryIt has recently been reported that heparin neutralizes the inhibitory effect of prostacyclin (PGI2) on human platelet aggregation. The mechanism of this interaction has not yet been unequivocally established. We present here evidence that heparin (Liquemin Roche) does not react directly with PGI2 but counteracts its inhibitory effect by potentiating platelet aggregation. In the absence of heparin, PGI2 was a less effective inhibitor of platelet aggregation induced by the combination of ADP and serotonin than by ADP alone. Moreover, the inhibitory effect of PGI2 was similarly reduced when increasing the concentrations of ADP (in the absence of heparin). The lack of a specific interaction between heparin and PGI2 is supported by the observation that, in the presence of heparin, other prostaglandins such as PGD2 and PGE1, and a non-prostanoid compound such as adenosine also appeared to lose their inhibitory potency. It is concluded that heparin opposes platelet aggregation inhibitory effect of PGI2 by enhancement of platelet aggregation.

Correlation between in vitro and in vivo Data of Radiolabeled Peptide for Tumor Targeting

2019 ◽  
Vol 19 (12) ◽  
pp. 950-960
Author(s):  
Soghra Farzipour ◽  
Seyed Jalal Hosseinimehr
Keyword(s):  
Tumor Targeting ◽  
Single Photon ◽  
Specific Binding ◽  
Specific Interaction ◽  
Photon Emission ◽  
Emission Computed Tomography ◽  
Mixed Effect ◽  
Radiolabeled Peptides

Tumor-targeting peptides have been generally developed for the overexpression of tumor specific receptors in cancer cells. The use of specific radiolabeled peptide allows tumor visualization by single photon emission computed tomography (SPECT) and positron emission tomography (PET) tools. The high affinity and specific binding of radiolabeled peptide are focusing on tumoral receptors. The character of the peptide itself, in particular, its complex molecular structure and behaviors influence on its specific interaction with receptors which are overexpressed in tumor. This review summarizes various strategies which are applied for the expansion of radiolabeled peptides for tumor targeting based on in vitro and in vivo specific tumor data and then their data were compared to find any correlation between these experiments. With a careful look at previous studies, it can be found that in vitro unblock-block ratio was unable to correlate the tumor to muscle ratio and the success of radiolabeled peptide for in vivo tumor targeting. The introduction of modifiers’ approaches, nature of peptides, and type of chelators and co-ligands have mixed effect on the in vitro and in vivo specificity of radiolabeled peptides.

Successful Control of a Co-Infection Caused by Candida albicans and Pseudomonas aeruginosa in Keratitis

2020 ◽  
Vol 20 ◽  
Author(s):  
Debarati Paul ◽  
Suman Saha ◽  
Neelam Singh ◽  
Jayansgu Sengupta ◽  
Santi M. Mandal
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Candida Albicans ◽  
Histopathological Examination ◽  
Specific Interaction ◽  
Major Threat ◽  
Effective Combination ◽  
Male Farmer ◽  
Successful Control ◽  
The Right ◽  
Corneal Button

Introduction: Nowadays, co-infection by interspecific organisms is major threat in infection control. To identify the effective combination of drugs to control the keratitis caused by Candida albicans with Pseudomonas aeruginosa are attributed in this study. Materilas and Methods: The patient of a 47 years old male farmer with infection in the right eye which showed redness and watering was treated with fortified cefazolin and fortified tobramycin before referral. No pigmentation or vascularisation was noted. The excised corneal button was also subjected to microbiological and histopathological examination. Results: A rare case of keratitis caused by co-infection of Candida albicans with Pseudomonas aeruginosa was identified. Results confirmed the inter-specific interaction of the two microorganisms. Conclusion: Cases of co-infection by Candida and Pseudomonas are not abundantly reported and difficult to treat. In this case, treatment involved Amphotercin-B and ciprofloxacin, effectively eradicated the infection. This therapy may be successfully implied for such cases of co-infection in future.

EFFECT OF MMSC AND HSC ON REPARATIVE REGENERATION OF THE LIVER UNDER CONDITIONS OF ITS TOXIC DAMAGE

2020 ◽  
Vol 17 (3) ◽  
pp. 243-248
Author(s):  
I.Yu. Maklakova ◽  
◽  
V.V. Bazarniy ◽  
D.Yu. Grebnev ◽  
◽  
...  
Keyword(s):  
Dna Repair ◽  
Carbon Tetrachloride ◽  
Mitotic Activity ◽  
Liver Damage ◽  
Inflammatory Activity ◽  
Control Group ◽  
Nacl Solution ◽  
Repair Enzymes ◽  
Toxic Liver Damage ◽  
Hsc Transplantation

The aim of this study was to study the effect of combined MMSC and HSC transplantation on liver regeneration under conditions of toxic carbon tetrachloride damage. Materials and methods. The study was performed on white male mice with toxic liver damage by intraperitoneal administration of carbon tetrachloride at a dose of 50 µl per mouse once. An hour after modeling liver damage, placental MMSCs and HSCs were administered intravenously at a dose of 4 million cells/kg and 330 thousand cells/kg, respectively, suspended in 0.2 ml of 0.9% NaCl solution. Control group animals were given 0.9% NaCl solution-0.2 ml intravenously. On days 1, 3, and 7 after cell transplantation, changes in inflammatory activity in the liver were evaluated, and mitotic and apoptotic indices were determined. On the 7th day after the introduction of cells, the activity of DNA repair enzymes of the PARP family was analyzed. Results. Combined MMSC and HSC transplantation leads to a decrease in the index of inflammatory activity in the liver due to a decrease in necrosis, hepatocyte dystrophy, and a decrease in infiltration. As a result of the study, an increase in the activity of PARP repair enzymes was found, which led to a decrease in programmed cell death. Also, cotransplantation of MMSCs and HSCs was accompanied by increased mitotic activity of hepatocytes. Conclusion. Cotransplantation of MMSCs and HSCs under conditions of toxic liver damage reduces the inflammatory response, stimulates the mitotic activity of hepatocytes, and increases the activity of enzymes of the DNA repair system. Activation of the liver's reparative system, in turn, reduces the programmed death of hepatocytes.

Solvation and redox properties of [Co(en)3]3+-[Co(en)3]2+ system

1980 ◽  
Vol 45 (2) ◽  
pp. 335-338 ◽  
Author(s):  
Adéla Kotočová ◽  
Ulrich Mayer
Keyword(s):  
Hydrogen Bond ◽  
Lewis Acid ◽  
Specific Interaction ◽  
Redox Properties ◽  
Solvation Effect ◽  
Interacting Particles ◽  
Acid Base ◽  
Polar Solvents ◽  
Oxidation Reduction ◽  
Solvent Molecules

The solvation effect of a number of nonaqueous polar solvents was studied on the oxidation-reduction properties of the [Co(en)3]3+-[Co(en)3]2+ system. Interactions of these ions with the solvent molecules are discussed in terms of their coordination, which is accompanied by a specific interaction of the Lewis acid-base type, namely formation of a hydrogen bond between the interacting particles. This is the main controlling factor of the redox properties of the studied system.

scholarly journals Recent advances in understanding NRF2 as a druggable target: development of pro-electrophilic and non-covalent NRF2 activators to overcome systemic side effects of electrophilic drugs like dimethyl fumarate

F1000Research ◽  
2017 ◽  
Vol 6 ◽  
pp. 2138 ◽  
Author(s):  
Takumi Satoh ◽  
Stuart Lipton
Keyword(s):  
Side Effects ◽  
Specific Interaction ◽  
Dimethyl Fumarate ◽  
Carnosic Acid ◽  
European Medicines Agency ◽  
Related Factor ◽  
Inflammatory Phase ◽  
First Case ◽  
Systemic Side Effects ◽  
Transcriptional Pathway

Dimethyl fumarate (DMF) is an electrophilic compound previously called BG-12 and marketed under the name Tecfidera®. It was approved in 2013 by the US Food and Drug Administration and the European Medicines Agency for the treatment of relapsing multiple sclerosis. One mechanism of action of DMF is stimulation of the nuclear factor erythroid 2-related factor 2 (NRF2) transcriptional pathway that induces anti-oxidant and anti-inflammatory phase II enzymes to prevent chronic neurodegeneration. However, electrophiles such as DMF also produce severe systemic side effects, in part due to non-specific S-alkylation of cysteine thiols and resulting depletion of glutathione. This mini-review presents the present status and future strategy for NRF2 activators designed to avoid these side effects. Two modes of chemical reaction leading to NRF2 activation are considered here. The first mode is S-alkylation (covalent reaction) of thiols in Kelch-like ECH-associated protein 1 (KEAP1), which interacts with NRF2. The second mechanism involves non-covalent pharmacological inhibition of protein-protein interactions, in particular domain-specific interaction between NRF2 and KEAP1 or other repressor proteins involved in this transcriptional pathway. There have been significant advances in drug development using both of these mechanisms that can potentially avoid the systemic side effects of electrophilic compounds. In the first case concerning covalent reaction with KEAP1, monomethyl fumarate and monoethyl fumarate appear to represent safer derivatives of DMF. In a second approach, pro-electrophilic drugs, such as carnosic acid from the herb Rosmarinus officinalis, can be used as a safe pro-drug of an electrophilic compound. Concerning non-covalent activation of NRF2, drugs are being developed that interfere with the direct interaction of KEAP1-NRF2 or inhibit BTB domain and CNC homolog 1 (BACH1), which is a transcriptional repressor of the promoter where NRF2 binds.

scholarly journals Development of an HTS Assay for the Search of Anti-influenza Agents Targeting the Interaction of Viral RNA with the NS1 Protein

2008 ◽  
Vol 13 (7) ◽  
pp. 581-590 ◽  
Author(s):  
Marta Maroto ◽  
Yolanda Fernandez ◽  
Juan Ortin ◽  
Fernando Pelaez ◽  
M. Angerles Cabello
Keyword(s):  
Influenza A Virus ◽  
Influenza A ◽  
Cytopathic Effect ◽  
Nonstructural Protein ◽  
Specific Interaction ◽  
Chemical Compounds ◽  
Viral Rna ◽  
Ns1 Protein ◽  
Rna Molecules ◽  
Novel Target

The NS1 protein is a nonstructural protein encoded by the influenza A virus. It is responsible for many alterations produced in the cellular metabolism upon infection by the virus and for modulation of virus virulence. The NS1 protein is able to perform a large variety of functions due to its ability to bind various types of RNA molecules, from both viral and nonviral origin, and to interact with several cell factors. With the aim of exploring whether the binding of NS1 protein to viral RNA (vRNA) could constitute a novel target for the search of anti-influenza drugs, a filter-binding assay measuring the specific interaction between the recombinant His-NS1 protein from influenza A virus and a radiolabeled model vRNA ( 32P-vNSZ) was adapted to a format suitable for screening and easy automation. Flashplate® technology (PerkinElmer, Waltham, MA), either in 96- or 384-well plates, was used. The Flashplate® wells were precoated with the recombinant His-NS1 protein, and the binding of His-NS1 to a 35S-vNSZ probe was measured. A pilot screening of a collection of 27,520 mixtures of synthetic chemical compounds was run for inhibitors of NS1 binding to vRNA. We found 3 compounds in which the inhibition of NS1 binding to vRNA, observed at submicromolar concentrations, was correlated with a reduction of the cytopathic effect during the infection of cell cultures with influenza virus. These results support the hypothesis that the binding of NS1 to vRNA could be a novel target for the development of anti-influenza drugs. ( Journal of Biomolecular Screening 2008:581-590)

scholarly journals SIR2-Induced Inviability Is Suppressed by Histone H4 Overexpression

Genetics ◽  
2002 ◽  
Vol 162 (2) ◽  
pp. 973-976 ◽  
Author(s):  
Mirela Matecic ◽  
Shelagh Stuart ◽  
Scott G Holmes
Keyword(s):  
Specific Interaction ◽  
Histone H3 ◽  
Yeast Cells ◽  
High Expression ◽  
Histone H4

Abstract We have identified histone H4 as a high-expression suppressor of Sir2-induced inviability in yeast cells. Overexpression of histone H3 does not suppress Sir2-induced lethality, nor does overexpression of histone H4 alleles associated with silencing defects. These results suggest a direct and specific interaction between Sir2 and H4 in the silencing mechanism.

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