scholarly journals The Site of Action of the Antiterminator Protein N from the Lambdoid Phage H-19B

2007 ◽  
Vol 282 (42) ◽  
pp. 30997-31007 ◽  
Author(s):  
Anoop Cheeran ◽  
Nanci R. Kolli ◽  
Ranjan Sen
Keyword(s):  
Lambdoid Phage ◽  
Site Of Action

Site of action of ethacrynic acid

1966 ◽  
Vol 118 (2) ◽  
pp. 117-122 ◽  
Author(s):  
W. J. Flanigan
Keyword(s):  
Ethacrynic Acid ◽  
Site Of Action

Effects of Ellagic Acid upon the Rabbit Fibrinolytic System

1972 ◽  
Vol 27 (01) ◽  
pp. 063-071
Author(s):  
S. G Iatridis ◽  
P. G Iatridis
Keyword(s):  
Continuous Infusion ◽  
Ellagic Acid ◽  
Animal Experimentation ◽  
Inhibitory Effect ◽  
In Vivo Studies ◽  
Clot Lysis ◽  
Hageman Factor ◽  
Lysis Activity ◽  
Site Of Action

SummaryThe present investigation deals with in vivo studies of possible relations of active Hageman factor (HFa) to the problems of thrombolysis. The study is based upon animal experimentation in which 40 normal, 5 dicumarolized and 5 heparinized rabbits each received ellagic acid (Elac 10-2 M) by intravenous continuous infusion at a rate of 1 ml/min for a period of 25 min. The data suggest that the Elac infusion induced in vivo activation of HF. Streptokinase (SK) injection 25 min from the start of Elac i. v. infusion failed to induce clot lysis in blood drawn one min after its injection. The phenomenon was more prominent with low (SK 250 U or 500 U) concentrations of SK. With higher concentrations, SK-induced clot lysis activity was not affected by Elac infusion.In dicumarolized and heparinized rabbits Elac infusion still counteracted the fibrinolysis activating effect of low concentration of SK. The possibility that the above described phenomenon was due to either hypercoagulability or to a non-specific inhibitory effect of Elac upon SK was explored and excluded.It is concluded that HFa and SK have the same site of action. Thus it seems that HFa may block the precursor upon which SK acts by forming a complex with it. It is stressed that activation of this precursor by HFa requires a suitable surface.

Low melatonin as a contributor to SARS-CoV-2 disease

2020 ◽  
Vol 3 (4) ◽  
pp. 558-576
Author(s):  
Seithikurippu R Pandi-Perumal ◽  
Daniel P Cardinali ◽  
Russel J Reiter ◽  
Gregory M Brown
Keyword(s):  
Reactive Oxygen Species ◽  
Oxidative Phosphorylation ◽  
Pineal Gland ◽  
Oxygen Species ◽  
Cytokine Storm ◽  
Major Site ◽  
Immune Modulator ◽  
Inflammatory Agent ◽  
Site Of Action ◽  
Extrapineal Melatonin

That the pineal gland is a source of melatonin is widely known; however, by comparison, few know of the much larger pool of extrapineal melatonin. That pool is widely distributed in all animals, including those that do not have a pineal gland, e.g., insects.  Extrapineal melatonin is not released into the blood but is used locally to function as an antioxidant, anti-inflammatory agent, etc. A major site of action of peripherally-produced melatonin is the mitochondria where it neutralizes reactive oxygen species (ROS) that are generated during oxidative phosphorylation. Its role also includes major actions as an immune modulator reducing overreactions to foreign agents while simultaneously boosting immune processes. During a pandemic such as coronavirus disease 2019 (COVID-19), caused by the virus SARS-CoV-2, melatonin is capable of suppressing the damage inflicted by the cytokine storm. The implications of melatonin in susceptibility and treatment of COVID-19 disease are discussed. 

THYROID STIMULATORS AND THYROID STIMULATION

1971 ◽  
Vol 66 (3) ◽  
pp. 558-576 ◽  
Author(s):  
Gerald Burke
Keyword(s):  
Regulatory System ◽  
Control Site ◽  
Thyroid Cell ◽  
Primary Control ◽  
Physico Chemical ◽  
Site Of Action ◽  
Long Acting

ABSTRACT A long-acting thyroid stimulator (LATS), distinct from pituitary thyrotrophin (TSH), is found in the serum of some patients with Graves' disease. Despite the marked physico-chemical and immunologic differences between the two stimulators, both in vivo and in vitro studies indicate that LATS and TSH act on the same thyroidal site(s) and that such stimulation does not require penetration of the thyroid cell. Although resorption of colloid and secretion of thyroid hormone are early responses to both TSH and LATS, available evidence reveals no basic metabolic pathway which must be activated by these hormones in order for iodination reactions to occur. Cyclic 3′, 5′-AMP appears to mediate TSH and LATS effects on iodination reactions but the role of this compound in activating thyroidal intermediary metabolism is less clear. Based on the evidence reviewed herein, it is suggested that the primary site of action of thyroid stimulators is at the cell membrane and that beyond the(se) primary control site(s), there exists a multifaceted regulatory system for thyroid hormonogenesis and cell growth.

Nanotechnology Based Delivery Systems of Drugs Currently Used to Treat Alzheimer’s Disease

2020 ◽  
Vol 10 (3) ◽  
pp. 228-247
Author(s):  
Niloufar Choubdar ◽  
Sara Avizheh
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Polymeric Nanoparticles ◽  
Biological Fluids ◽  
Delivery Systems ◽  
Original Research ◽  
Sustained Drug Release ◽  
The Past ◽  
Site Of Action ◽  
Therapeutic Compound

Alzheimer’s Disease (AD) is one of the most common forms of dementia affecting over 46 million people, according to AD International. Over the past few decades, there has been considerable interest in developing nanomedicines. Using nanocarriers, the therapeutic compound could be delivered to the site of action where it gets accumulated. This accumulation, therefore, reduces the required doses for therapy. Alternatively, using nanocarriers decreases the side effects. Nanotechnology has had a great contribution in developing Drug Delivery Systems (DDS). These DDS could function as reservoirs for sustained drug release or control the pharmacokinetics and biodistribution of the drugs. In the current review, we have collected 38 original research articles using nanotechnology as DDS for the clinically used cholinesterase inhibitor drugs donepezil (DPZ), Rivastigmine (Riv), and galantamine (Gal) used for AD treatment from 2002 to 2017 from Scopus and PubMed databases. Regarding DDS used for DPZ, most of the research in recent years dealt with polymeric nanoparticles (NPs) including Poly-D, L-Lactide-Co-Glycolide (PLGA), and chitosans (CHs), then Liposomes (LPs), nanogels, and natural products, respectively. In terms of Riv most of the research performed was focused on polymeric NPs including PLGA, polylactic acid (PLA), Poly-Ε-Caprolactone (PCL), poly-alkyl-cyanoacrylates, CH, gelatin and then LPs. The highest application of NPs in regard to Gal was related to modified LPs and polymeric NPs. Polymeric NPs demonstrate safety, higher stability in biological fluids and against enzymatic metabolism, biocompatibility, bioavailability, and improved encapsulation efficacy. LPs, another major delivery system used, demonstrate biocompatibility, ease of surface modification, and amphiphilic nature.

Effects of Diphenylether Herbicides on Reactions of Mitochondria and Chloroplasts

Weed Science ◽  
1970 ◽  
Vol 18 (5) ◽  
pp. 636-642 ◽  
Author(s):  
D. E. Moreland ◽  
W. J. Blackmon ◽  
H. G. Todd ◽  
F. S. Farmer
Keyword(s):  
Electron Transport ◽  
Oxygen Uptake ◽  
Spinacia Oleracea ◽  
White Potato ◽  
Light Reaction ◽  
Site Of Action ◽  
Transport Inhibitors ◽  
Atp Generation ◽  
A Site ◽  
Limited Oxygen

Effects of three diphenylether herbicides [2,4-dichlorophenyl-p-nitrophenyl ether (nitrofen); 2,4,6-trichlorophenyl-4′-nitrophenyl ether (hereinafter referred to as MC-1478); and 2,4′-dinitro-4-trifluoromethyl-diphenylether (hereinafter referred to as C-6989)] were measured on phosphorylation and electron transport in spinach(Spinacia oleraceaL.) chloroplasts, and mung bean(Phaseolus aureusL., var. Jumbo) and white potato tuber(Solarium tuberosumL.) mitochondria. All of the diphenylethers acted primarily as inhibitors of chloroplast noncyclic electron transport, and the coupled photophosphorylation. The compounds ranked in the following decreasing order of inhibitory effectiveness: MC-1478 ≥ C-6989 >> nitrofen. A site of action close to light reaction II was suggested. At high molar concentrations, marginal interference with cyclic electron transport or phosphorylation was obtained. In mitochondria, MC-1478 and nitrofen acted primarily as electron transport inhibitors with malate, NADH, and succinate as substrates. MC-1478 was a slightly stronger inhibitor than nitrofen. Only slight stimulation of ADP-limited oxygen uptake was obtained during the oxidation of NADH and succinate; whereas, strong inhibition of oxygen uptake was obtained with malate. C-6989 also weakly stimulated ADP-limited oxygen uptake with NADH and succinate but differed from the two chlorinated diphenylethers in that electron transport was not inhibited when ADP was present in excess. Interference with ATP generation could be one of the mechanisms through which the phytotoxicity of diphenylether herbicides is expressed.

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