STUDIES ON THE EFFECTS OF PHAGOCYTIC STIMULATION ON MICROBIAL DISEAS: VI. SOME FACTORS DECREASING PHAGOCYTIC ACTIVITY OF MONOCYTES AGAINST TUBERCLE BACILLI, STRAIN BCG

1956 ◽  
Vol 34 (1) ◽  
pp. 580-586
Author(s):  
László Kátó ◽  
Béla Gözsy
Keyword(s):  
Mechanism Of Action ◽  
Phagocytic Activity ◽  
Point Of View ◽  
Experimental Tuberculosis

An antihistamine if present in a concentration of 0.1 to 100 μgm. per ml. decreased considerably the in vitro phagocytic activity of normal monocytes. The stimulated phagocytic activity of monocytes by histamine or 1,4-dimethyl-7-isopropyl-bicyclo-decapentane was antagonized by the antihistamines. Monocytes withdrawn from antihistamine treated animals showed a markedly lesser phagocytic activity than monocytes from untreated animals. The results are discussed from the point of view of the mechanism of action of 1,4-dimethyl-7-isopropyl-bicyclo-decapentane in experimental tuberculosis.

STUDIES ON THE EFFECTS OF PHAGOCYTIC STIMULATION ON MICROBIAL DISEAS: VI. SOME FACTORS DECREASING PHAGOCYTIC ACTIVITY OF MONOCYTES AGAINST TUBERCLE BACILLI, STRAIN BCG

1956 ◽  
Vol 34 (3) ◽  
pp. 580-586
Author(s):  
László Kátó ◽  
Béla Gözsy
Keyword(s):  
Mechanism Of Action ◽  
Phagocytic Activity ◽  
Point Of View ◽  
Experimental Tuberculosis

An antihistamine if present in a concentration of 0.1 to 100 μgm. per ml. decreased considerably the in vitro phagocytic activity of normal monocytes. The stimulated phagocytic activity of monocytes by histamine or 1,4-dimethyl-7-isopropyl-bicyclo-decapentane was antagonized by the antihistamines. Monocytes withdrawn from antihistamine treated animals showed a markedly lesser phagocytic activity than monocytes from untreated animals. The results are discussed from the point of view of the mechanism of action of 1,4-dimethyl-7-isopropyl-bicyclo-decapentane in experimental tuberculosis.

The Effect of Dipyridamole and RA 233 on Human Platelet Function in Vitro

1973 ◽  
Vol 29 (03) ◽  
pp. 694-700 ◽  
Author(s):  
Paul L. Rifkin ◽  
Marjorie B. Zucker
Keyword(s):  
Mechanism Of Action ◽  
Human Blood ◽  
Glass Bead ◽  
Heart Valves ◽  
Human Platelet ◽  
Drug Effects ◽  
Simple Relation ◽  
Prosthetic Heart Valves ◽  
Induced Aggregation

SummaryDipyridamole (Persantin) is reported to prolong platelet survival and inhibit embolism in patients with prosthetic heart valves, but its mechanism of action is unknown. Fifty jxM dipyridamole failed to reduce the high percentage of platelets retained when heparinized human blood was passed through a glass bead column, but prolonged the inhibition of retention caused by disturbing blood in vitro. Possibly the prostheses act like disturbance. Although RA 233 was as effective as dipyridamole in inhibiting the return of retention, it was less effective in preventing the uptake of adenosine into erythrocytes, and more active in inhibiting ADP-induced aggregation and release. Thus there is no simple relation between these drug effects.

Enzyme Promiscuous Activity: How to Define it and its Evolutionary Aspects

2020 ◽  
Vol 27 (5) ◽  
pp. 400-410
Author(s):  
Valentina De Luca ◽  
Luigi Mandrich
Keyword(s):  
Gene Evolution ◽  
Sequence Divergence ◽  
High Specificity ◽  
Industrial Applications ◽  
Point Of View ◽  
Enzyme Promiscuity ◽  
Primary Activity ◽  
Starting Point ◽  
Main Activity

: Enzymes are among the most studied biological molecules because better understanding enzymes structure and activity will shed more light on their biological processes and regulation; from a biotechnological point of view there are many examples of enzymes used with the aim to obtain new products and/or to make industrial processes less invasive towards the environment. Enzymes are known for their high specificity in the recognition of a substrate but considering the particular features of an increasing number of enzymes this is not completely true, in fact, many enzymes are active on different substrates: this ability is called enzyme promiscuity. Usually, promiscuous activities have significantly lower kinetic parameters than to that of primary activity, but they have a crucial role in gene evolution. It is accepted that gene duplication followed by sequence divergence is considered a key evolutionary mechanism to generate new enzyme functions. In this way, promiscuous activities are the starting point to increase a secondary activity in the main activity and then get a new enzyme. The primary activity can be lost or reduced to a promiscuous activity. In this review we describe the differences between substrate and enzyme promiscuity, and its rule in gene evolution. From a practical point of view the knowledge of promiscuity can facilitate the in vitro progress of proteins engineering, both for biomedical and industrial applications. In particular, we report cases regarding esterases, phosphotriesterases and cytochrome P450.

Insecticidal Active Rotenoids from Plant Parts and Callus Culture of Medicago sativa L. from a Semiarid Region of India (Rajasthan)

2020 ◽  
Vol 16 (6) ◽  
pp. 937-941
Author(s):  
Sharad Vats ◽  
Preeti Mehra
Keyword(s):  
Medicago Sativa ◽  
Callus Culture ◽  
Point Of View ◽  
Semiarid Region ◽  
Disease Vectors ◽  
Vector Borne Diseases ◽  
Plant Parts ◽  
Resistant Varieties ◽  
Medicago Sativa L

Background: Vector-borne diseases are quite prevalent globally and are one of the major causes of deaths due to infectious diseases. There is an availability of synthetic insecticides, however, their excessive and indiscriminate use have resulted in the emergence of resistant varieties of insects. Thus, a search for novel biopesticide has become inevitable. Methods: Rotenoids were isolated and identified from different parts of Medicago sativa L. This group of metabolites was also identified in the callus culture, and the rotenoid content was monitored during subculturing for a period of 10 months. Enhancement of the rotenoid content was evaluated by feeding precursors in a tissue culture medium. Results: Four rotenoids (elliptone, deguelin, rotenone and Dehydrorotenone) were identified, which were confirmed using spectral and chromatographic techniques. The maximum rotenoid content was found in the seeds (0.33±0.01%), followed by roots (0.31±0.01%) and minimum in the aerial parts (0.20±0.05%). A gradual decrease in the rotenoid content was observed with the ageing of subcultured tissue maintained for 10 months. The production of rotenoids was enhanced up to 2 folds in the callus culture using amino acids, Phenylalanine and Methionine as precursors as compared to the control. The LC50 value of the rotenoids was found to be 91 ppm and 162 ppm against disease vectors of malaria and Dracunculiasis, respectively. Conclusion: The study projects M. sativa as a novel source of biopesticide against the disease vectors of malaria and Dracunculiasis. The use of precursors to enhance the rotenoid content in vitro can be an effective venture from a commercial point of view.

scholarly journals In vitro activities of novel catecholate siderophores against Plasmodium falciparum.

1996 ◽  
Vol 40 (9) ◽  
pp. 2094-2098 ◽  
Author(s):  
B Pradines ◽  
F Ramiandrasoa ◽  
L K Basco ◽  
L Bricard ◽  
G Kunesch ◽  
...  
Keyword(s):  
Plasmodium Falciparum ◽  
Mechanism Of Action ◽  
Ribonucleotide Reductase ◽  
Antimalarial Activity ◽  
Iron Chelators ◽  
Resistant Clone ◽  
Iron Deprivation ◽  
Level Of Activity ◽  
Susceptible Clone

The activities of novel iron chelators, alone and in combination with chloroquine, quinine, or artemether, were evaluated in vitro against susceptible and resistant clones of Plasmodium falciparum with a semimicroassay system. N4-nonyl,N1,N8-bis(2,3-dihydroxybenzoyl) spermidine hydrobromide (compound 7) demonstrated the highest level of activity: 170 nM against a chloroquine-susceptible clone and 1 microM against a chloroquine-resistant clone (50% inhibitory concentrations). Compounds 6, 8, and 10 showed antimalarial activity with 50% inhibitory concentrations of about 1 microM. Compound 7 had no effect on the activities of chloroquine, quinine, and artemether against either clone, and compound 8 did not enhance the schizontocidal action of either chloroquine or quinine against the chloroquine-resistant clone. The incubation of compound 7 with FeCI3 suppressed or decreased the in vitro antimalarial activity of compound 7, while no effect was observed with incubation of compound 7 with CuSO4 and ZnSO4. These results suggest that iron deprivation may be the main mechanism of action of compound 7 against the malarial parasites. Chelator compounds 7 and 8 primarily affected trophozoite stages, probably by influencing the activity of ribonucleotide reductase, and thus inhibiting DNA synthesis.

In Vitro Methods for the Assessment of L-Cysteine Conjugate Toxicity

1994 ◽  
Vol 22 (2) ◽  
pp. 72-80
Author(s):  
Lorraine D. Buckberry ◽  
Harriet J. Adcock ◽  
Jeremy Adler ◽  
Ian S. Blagbrough ◽  
Peter J. Gaskin ◽  
...  
Keyword(s):  
Mechanism Of Action ◽  
Mammalian Species ◽  
Mercapturic Acid ◽  
Assay Method ◽  
Cellular Toxicity ◽  
In Vitro Methods ◽  
Metabolic Route ◽  
Assay Methods ◽  
Chang Liver

L-Cysteine conjugates are normally metabolised via N-acetylation to produce a mercapturic acid. However, a recently identified metabolic route (C-S lysis) may lead to the generation of an unstable thiol which has been demonstrated to be responsible for toxicity in various mammalian species. Human Chang liver cells were challenged with a number of established L-cysteine conjugates. The cellular toxicity of these compounds was determined using a range of assay procedures, which provided differing information, depending on the assay method used. These observations were then investigated in order to establish which system would provide the most reliable indication of C-S lyase toxicity and whether any information on the mechanism of action could be obtained by these assay methods.

scholarly journals Potential of Probiotic Frozen Blackcurrant Products: Consumer Preference, Physicochemical Characterization, and Cell Viability

Foods ◽  
2021 ◽  
Vol 10 (4) ◽  
pp. 792
Author(s):  
Kati Väkeväinen ◽  
Noora Rinkinen ◽  
Roosa-Maria Willman ◽  
Jenni Lappi ◽  
Kaisa Raninen ◽  
...  
Keyword(s):  
Storage Time ◽  
Physicochemical Characterization ◽  
Consumer Preference ◽  
Nutritional Composition ◽  
Point Of View ◽  
Raw Material ◽  
Frozen Food ◽  
High Viability ◽  
Food Applications

Blackcurrant is a healthy, affordable, and traditionally gardened berry that, thus far, has been underused in food applications. From the consumers’ point of view, the acidic taste of blackcurrants is a challenge; therefore, these berries have mainly been utilized for sugary juice production. This research study aimed to develop a frozen vegan blackcurrant product with pleasant sensory properties and potential probiotic function. A candidate probiotic, Lactoplantibacillus plantarum Q823, was used in the manufacturing process. The physicochemical properties, nutritional composition, and consumer preference for the developed product were assessed, as was the viability of L. plantarum Q823 during storage time and in an in vitro gastrointestinal model. Consumers (n = 71) perceived the developed product to be pleasant. L. plantarum Q823 had high viability counts (log colony forming units (cfu) g−1 7.0 ± 0.38) in the final product, although the viability of L. plantarum Q823 during storage time needs to be enhanced to obtain a probiotic product. Thus, within an optimized formulation, blackcurrant berries represent a potential raw material for functional frozen food products.

scholarly journals Effect of memantine, an anti-Alzheimer’s drug, on rodent microglial cells in vitro

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Toru Murakawa-Hirachi ◽  
Yoshito Mizoguchi ◽  
Masahiro Ohgidani ◽  
Yoshinori Haraguchi ◽  
Akira Monji
Keyword(s):  
Neuronal Death ◽  
Phagocytic Activity ◽  
Microglial Cell ◽  
Cell Function ◽  
Microglial Cells ◽  
Phagocytosis Assay ◽  
Intracellular Ca ◽  
Β Amyloid ◽  
The Brain

AbstractThe pathophysiology of Alzheimer’s disease (AD) is related to neuroinflammatory responses mediated by microglia. Memantine, an antagonist of N-methyl-d-aspartate (NMDA) receptors used as an anti-Alzheimer’s drug, protects from neuronal death accompanied by suppression of proliferation and activation of microglial cells in animal models of AD. However, it remains to be tested whether memantine can directly affect microglial cell function. In this study, we examined whether pretreatment with memantine affects intracellular NO and Ca2+ mobilization using DAF-2 and Fura-2 imaging, respectively, and tested the effects of memantine on phagocytic activity by human β-Amyloid (1–42) phagocytosis assay in rodent microglial cells. Pretreatment with memantine did not affect production of NO or intracellular Ca2+ elevation induced by TNF in rodent microglial cells. Pretreatment with memantine also did not affect the mRNA expression of pro-inflammatory (TNF, IL-1β, IL-6 and CD45) or anti-inflammatory (IL-10, TGF-β and arginase) phenotypes in rodent microglial cells. In addition, pretreatment with memantine did not affect the amount of human β-Amyloid (1–42) phagocytosed by rodent microglial cells. Moreover, we observed that pretreatment with memantine did not affect 11 major proteins, which mainly function in the phagocytosis and degradation of β-Amyloid (1–42), including TREM2, DAP12 and neprilysin in rodent microglial cells. To the best of our knowledge, this is the first report to suggest that memantine does not directly modulate intracellular NO and Ca2+ mobilization or phagocytic activity in rodent microglial cells. Considering the neuroinflammation hypothesis of AD, the results might be important to understand the effect of memantine in the brain.

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