scholarly journals The Biochemical Activity of Enterotoxin and Non-Enterotoxin Producing Staphylococci

1977 ◽  
Vol 18 (2) ◽  
pp. 266-273
Author(s):  
Marie-Louise Danielsson ◽  
Bo Hellberg
Keyword(s):  
Biochemical Activity

Experimental Prediction of the Evolution of Cefepime Resistance From the CMY-2 AmpC β-Lactamase

Genetics ◽  
2003 ◽  
Vol 164 (1) ◽  
pp. 23-29
Author(s):  
Miriam Barlow ◽  
Barry G Hall
Keyword(s):  
Good Predictor ◽  
Evolutionary Potential ◽  
Biochemical Activity ◽  
Class A ◽  
Naturally Occurring ◽  
Experimental Prediction ◽  
Lactam Antibiotic ◽  
High Level ◽  
Level Resistance

Abstract Understanding of the evolutionary histories of many genes has not yet allowed us to predict the evolutionary potential of those genes. Intuition suggests that current biochemical activity of gene products should be a good predictor of the potential to evolve related activities; however, we have little evidence to support that intuition. Here we use our in vitro evolution method to evaluate biochemical activity as a predictor of future evolutionary potential. Neither the class C Citrobacter freundii CMY-2 AmpC β-lactamase nor the class A TEM-1 β-lactamase confer resistance to the β-lactam antibiotic cefepime, nor do any of the naturally occurring alleles descended from them. However, the CMY-2 AmpC enzyme and some alleles descended from TEM-1 confer high-level resistance to the structurally similar ceftazidime. On the basis of the comparison of TEM-1 and CMY-2, we asked whether biochemical activity is a good predictor of the evolutionary potential of an enzyme. If it is, then CMY-2 should be more able than the TEMs to evolve the ability to confer higher levels of cefepime resistance. Although we generated CMY-2 evolvants that conferred increased cefepime resistance, we did not recover any CMY-2 evolvants that conferred resistance levels as high as the best cefepime-resistant TEM alleles.

scholarly journals Numerical analysis of the characteristics ofCorynebacterium diphtheriaestrains isolated in Victoria from 1962 to 1971

1975 ◽  
Vol 75 (3) ◽  
pp. 413-424
Author(s):  
L. F. Gibson
Keyword(s):  
Numerical Analysis ◽  
Common Ancestor ◽  
Corynebacterium Diphtheriae ◽  
The State ◽  
The Other ◽  
Blood Agar ◽  
Antigenic Structure ◽  
Gradual Change ◽  
Biochemical Activity ◽  
Highly Active

SUMMARYA study of the incidence of diphtheria in the State of Victoria, Australia, was carried out. Numerical analysis of the characteristics of 264 strains ofCorynebacterium diphtheriaeisolated between 1962 and 1971 placed them into 18 varieties plus six strains which were unique in their combination of reactions to the characteristics examined. During the 10-year period, some varieties appeared inter mittently and were recognized by certain defining characteristics but exhibited a gradual change in their antigenic structure. In contrast, when the outbreaks were examined over shorter periods of time, a number of varieties and single strains were found which differed greatly from each other yet possessed the same major serotype antigen. These findings are discussed in terms of a 'one-parent' concept in which the varieties and single strains represent phases of a common ancestor.By inspection and analysis of the characteristics of the strains, certain associations were apparent. For instance, a correlation was found between the antigenic structure of the organism and the colonial appearance on tellurite blood agar. Similarly, correlation was observed between bacteriophage type, diphthericin type and biochemical activity in that a strain which was highly active in one of the properties was also very active in the other two.

scholarly journals Biochemical Activity and Hypoglycemic Effects ofRumex obtusifoliusL. Seeds Used in Armenian Traditional Medicine

2018 ◽  
Vol 2018 ◽  
pp. 1-9 ◽  
Author(s):  
Anush Aghajanyan ◽  
Armine Nikoyan ◽  
Armen Trchounian
Keyword(s):  
Herbal Remedy ◽  
Density Lipoprotein ◽  
Ethanol Extract ◽  
Liver Glycogen ◽  
Lipoprotein Cholesterol ◽  
Current Therapy ◽  
Total Phenolic ◽  
Control Group ◽  
Biochemical Activity ◽  
Cholesterol Levels

Diabetes mellitus (DM) is a serious chronic metabolic disorder. Various diseases are being treated with medicinal plants and that is because of the less side effects of the current therapy. The diversity of plants in Armenia is due to the singularity of natural environment. However, biochemical activity of these plants has not been studied well. Thus, the goal was to investigate biochemical activity and antihyperglycemic properties ofRumex obtusifoliusL. in rabbits with hyperglycemia. The high content of total phenolic compounds, flavonoids, and tannins has been determined in this plant extract. Oral administration of ethanol extract showed significant effect on hyperglycemia, reducing fasting glucose levels (57.3%, p<0.05), improving glucose tolerance, and increasing liver glycogen content (1.5-fold, p<0.01) compared to the hyperglycemic control group. Furthermore, ethanol extract ofR. obtusifoliusreduced total cholesterol, low-density lipoprotein cholesterol levels, and vice versa increased high-density lipoprotein cholesterol levels and also decreased liver enzymes levels (alanine aminotransferase and aspartate aminotransferase) compared with untreated group. These findings suggest thatR. obtusifoliusmay have beneficial effects and should be supplement, as herbal remedy in the treatment of DM.

scholarly journals Silver Nanoparticles Effects on In Vitro Germination, Growth, and Biochemical Activity of Tomato, Radish, and Kale Seedlings

Materials ◽  
2021 ◽  
Vol 14 (18) ◽  
pp. 5340
Author(s):  
Alicja Tymoszuk
Keyword(s):  
Silver Nanoparticles ◽  
Practical Importance ◽  
Plant Cells ◽  
Dry Weight ◽  
Guaiacol Peroxidase ◽  
In Vitro Germination ◽  
Vegetable Crops ◽  
Fresh Weight ◽  
Biochemical Activity

The interactions between nanoparticles and plant cells are still not sufficiently understood, and studies related to this subject are of scientific and practical importance. Silver nanoparticles (AgNPs) are one of the most commonly produced and used nanomaterials. This study aimed to investigate the influence of AgNPs applied at the concentrations of 0, 50, and 100 mg·L−1 during the process of in vitro germination as well as the biometric and biochemical parameters of developed seedlings in three vegetable species: Solanum lycopersicum L. ‘Poranek’, Raphanus sativus L. var. sativus ‘Ramona’, and Brassica oleracea var. sabellica ‘Nero di Toscana’. The application of AgNPs did not affect the germination efficiency; however, diverse results were reported for the growth and biochemical activity of the seedlings, depending on the species tested and the AgNPs concentration. Tomato seedlings treated with nanoparticles, particularly at 100 mg·L−1, had shorter shoots with lower fresh and dry weights and produced roots with lower fresh weight. Simultaneously, at the biochemical level, a decrease in the content of chlorophylls and carotenoids and an increase in the anthocyanins content and guaiacol peroxidase (GPOX) activity were reported. AgNPs-treated radish plants had shorter shoots of higher fresh and dry weight and longer roots with lower fresh weight. Treatment with 50 mg·L−1 and 100 mg·L−1 resulted in the highest and lowest accumulation of chlorophylls and carotenoids in the leaves, respectively; however, seedlings treated with 100 mg·L−1 produced less anthocyanins and polyphenols and exhibited lower GPOX activity. In kale, AgNPs-derived seedlings had a lower content of chlorophylls, carotenoids, and anthocyanins but higher GPOX activity of and were characterized by higher fresh and dry shoot weights and higher heterogeneous biometric parameters of the roots. The results of these experiments may be of great significance for broadening the scope of knowledge on the influence of AgNPs on plant cells and the micropropagation of the vegetable species. Future studies should be aimed at testing lower or even higher concentrations of AgNPs and other NPs and to evaluate the genetic stability of NPs-treated vegetable crops and their yielding efficiency.

scholarly journals Growth Regulators Affect the Growth and Biochemical Activity of Curcuma longa Plants Grown in vitro

2019 ◽  
Vol 11 (10) ◽  
pp. 277 ◽  
Author(s):  
Meire Pereira de Souza Ferrari ◽  
Mayara dos Santos Queiroz ◽  
Matheus Marquezini de Andrade ◽  
Jessica Rezende Trettel ◽  
Hélida Mara Magalhães
Keyword(s):  
Antioxidant Activity ◽  
Enzymatic Activity ◽  
Growth Regulators ◽  
Curcuma Longa ◽  
Ms Medium ◽  
Biochemical Activity ◽  
Root Collar Diameter ◽  
Collar Diameter ◽  
Root Collar

This study aimed to evaluate the in vitro growth and biochemical activity of Curcuma longa explants using different MS medium formulations and growth regulators. In all the experiments, plants were grown in MS medium supplemented with agar (6.5 g L-1) and pH adjusted to 5.8. In the first assay, the MS culture medium at 70% strength, supplemented with 30 g L-1 of sucrose, and without the addition of activated carbon, resulted in the highest number of shoots. The sucrose concentration of 60 g L-1, combined with the addition of actived charcoalin half-strength MS medium, resulted in the increased root dry mass, root collar diameter, and relative chlorophyll index. In the second assay, the highest root collar diameter and dry matter of shoots and roots were found in the MS medium supplemented with 4.44 BAP, 0.46 KIN, and 1.08 NAA. The MS medium with 8.88 BAP, 0.92 KIN, and 2.16 &mu;M NAA resulted in the highest number of shoots (7.75), number of leaves (35), and shoot length (88.57 mm). The antioxidant activity was significantly higher in the treatments that resulted in better plantlets growth performance, demonstrating that the antioxidant activity is related to other factors such as a possible role of growth regulators on the elicitation of compounds in plants. Superoxide dismutase had a high enzymatic activity in both assays, whereas the enzymatic activity of catalase and ascorbate peroxidase was dependent on the culture media used.

scholarly journals The Course Of Chronic Liver Disease In Patients With Covid-2019 (Literature Review And Own Data)

2021 ◽  
Vol 03 (09) ◽  
pp. 69-74
Author(s):  
Muxamedova Z.R. ◽  
Keyword(s):  
Liver Disease ◽  
Literature Review ◽  
Liver Diseases ◽  
Chronic Liver ◽  
Chronic Liver Diseases ◽  
Biochemical Activity ◽  
Severe Liver ◽  
Risk Of Mortality ◽  
The World ◽  
Severe Liver Damage

The pandemic of the new coronavirus COVID-19 has switched medicine around the world on the primary fight against this infection. Patients with chronic liver diseases require increased attention of doctors during an epidemic, since against the background of an exacerbation of their disease, not only the risk of contracting the COVID 19 viral infection increases, but also its more severe course. Patients with confirmed COVID-19 with severe liver damage - high biochemical activity. According to some reports, patients with a severe course of COVID-19 have an increase in ALT levels, a decrease in the number of platelets, a decrease in the level of albumin, and a connection (although not all indicators) with a higher risk of mortality is possible.

scholarly journals Transport of Alzheimer’s associated amyloid-β catalyzed by P-glycoprotein

PLoS ONE ◽  
2021 ◽  
Vol 16 (4) ◽  
pp. e0250371
Author(s):  
James W. McCormick ◽  
Lauren Ammerman ◽  
Gang Chen ◽  
Pia D. Vogel ◽  
John G. Wise
Keyword(s):  
Cell Culture ◽  
Atp Hydrolysis ◽  
Amyloid Β ◽  
Md Simulations ◽  
Membrane Transporter ◽  
Biochemical Activity ◽  
Glycoprotein P ◽  
P Glycoprotein ◽  
Hydrolysis Activity

P-glycoprotein (P-gp) is a critical membrane transporter in the blood brain barrier (BBB) and is implicated in Alzheimer’s disease (AD). However, previous studies on the ability of P-gp to directly transport the Alzheimer’s associated amyloid-β (Aβ) protein have produced contradictory results. Here we use molecular dynamics (MD) simulations, transport substrate accumulation studies in cell culture, and biochemical activity assays to show that P-gp actively transports Aβ. We observed transport of Aβ40 and Aβ42 monomers by P-gp in explicit MD simulations of a putative catalytic cycle. In in vitro assays with P-gp overexpressing cells, we observed enhanced accumulation of fluorescently labeled Aβ42 in the presence of Tariquidar, a potent P-gp inhibitor. We also showed that Aβ42 stimulated the ATP hydrolysis activity of isolated P-gp in nanodiscs. Our findings expand the substrate profile of P-gp, and suggest that P-gp may contribute to the onset and progression of AD.

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