3,336 research outputs found
In vitro study of the interaction between some fluoroquinolones and extracts of kola nitida seed
The cup diffusion method (CD) was used to evaluate the in vitro interaction of some fluoroquinolones (ciprofloxacin, pefloxacin and levofloxacin) with extracts of Kola nitida seed (KNS) against a clinical isolate of Escherichia coli. Minimum inhibitory concentration (MIC) of the drugs was determinedseparately and in combination with KNS extract in ratios of 0:5, 1:4, 2:3, 3:2, 4:1 and 5:0 against E. coli. The result of the study revealed that the MIC of the drugs decreased when combined with KNS extract. In other words, KNS extract potentiated the effects of the fluoroquinolones against E. coli
A study of the in vitro interaction of cotrimoxazole and ampicillin using the checkerboard method
In this study, the in vitro interaction of two standard antibiotics – cotrimoxazole and ampicillin trihydrate were studied by the checkerboard technique, using clinical isolates of P. aeruginosa, Staphylococcus aureus and Salmonella typhi. The organisms were exposed to the individual antibiotics as well as different combination ratios of the same, and the zones of inhibition as well as the minimum inhibitory concentrations (MICs) measured. Synergistic interactions were recorded by the antibiotics against Staph. aureus and S. typhi while indifferent interaction occurred with P. aeruginosa. P. aeruginosa however, showed resistance to the two antibiotics when they were used alone. The implication is that cotrimoxazole and ampicillin can be used in combination as a superior treatment of infections caused by Staph. aureus and S. typhi
Can dileptons reveal the in-medium properties of vector mesons?
Dilepton production from both pion-pion and kaon-antikaon annihilation in
heavy-ion collisions is studied using the relativistic transport model. The
formation of a rho meson from pion-pion annihilation and a phi meson from
kaon-antikaon annihilation, their propagation in the medium, and their decay
into dileptons are explicitly treated. Including the medium modifications of
the masses and widths of vector mesons as predicted by the QCD sum-rule
calculations, we study their effects on the dilepton invariant mass spectra
from heavy-ion collisions at SIS/GSI energies.Comment: 22 pages, 11 figures available upon request to [email protected]
The Prrx1eGFP Mouse Labels the Periosteum During Development and a Subpopulation of Osteogenic Periosteal Cells in the Adult
The identity of the cells that form the periosteum during development is controversial with current dogma suggesting these are derived from a Sox9-positive progenitor. Herein, we characterize a newly created Prrx1eGFP reporter transgenic mouse line during limb formation and postnatally. Interestingly, in the embryo Prrx1eGFP-labeled cells become restricted around the Sox9-positive cartilage anlage without themselves becoming Sox9-positive. In the adult, the Prrx1eGFP transgene live labels a subpopulation of cells within the periosteum that are enriched at specific sites, and this population is diminished in aged mice. The green fluorescent protein (GFP)-labeled subpopulation can be isolated using fluorescence-activated cell sorting (FACS) and represents approximately 8% of all isolated periosteal cells. The GFP-labeled subpopulation is significantly more osteogenic than unlabeled, GFP-negative periosteal cells. In addition, the osteogenic and chondrogenic capacity of periosteal cells in vitro can be extended with the addition of fibroblast growth factor (FGF) to the expansion media. We provide evidence to suggest that osteoblasts contributing to cortical bone formation in the embryo originate from Prrx1eGFP-positive cells within the perichondrium, which possibly piggyback on invading vascular cells and secrete new bone matrix. In summary, the Prrx1eGFP mouse is a powerful tool to visualize and isolate periosteal cells and to quantify their properties in the embryo and adult. © 2022 The Authors. JBMR Plus published by Wiley Periodicals LLC on behalf of American Society for Bone and Mineral Research
Evidence of general economic principles of bargaining and trade from 2,000 classroom experiments
Standardized classroom experiments provide evidence about how well scientific results reproduce when nearly identical methods are used. We use a sample of around 20,000 observations to test reproducibility of behaviour in trading and ultimatum bargaining. Double-auction results are highly reproducible and are close to equilibrium predictions about prices and quantities from economic theory. Our sample also shows robust correlations between individual surplus and trading order, and autocorrelation of successive price changes, which test different theories of price dynamics. In ultimatum bargaining, the large dataset provides sufficient power to identify that equal-split offers are accepted more often and more quickly than slightly unequal offers. Our results imply a general consistency of results across a variety of different countries and cultures in two of the most commonly used designs in experimental economics
Does the aldosterone: renin ratio predict the efficacy of spironolactone over bendroflumethiazide in hypertension? A clinical trial protocol for RENALDO (RENin-ALDOsterone) study
<p>Background: High blood pressure is an important determinant of cardiovascular disease risk. Treated hypertensives do not attain a risk level equivalent to normotensives. This may be a consequence of suboptimal blood pressure control to which indiscriminate use of antihypertensive drugs may contribute. Indeed the recent ALLHAT[1]study suggests that thiazides should be given first to virtually all hypertensives. Whether this is correct or whether different antihypertensive therapies should be targeted towards different patients is a major unresolved issue, which we address in this study.</p>
<p>The measurement of the ratio of aldosterone: renin is used to identify hypertensive subjects who may respond well to treatment with the aldosterone antagonist spironolactone. It is not known if subjects with a high ratio have aldosteronism or aldosterone-sensitive hypertension is debated but it is important to know whether spironolactone is superior to other diuretics such as bendroflumethiazide in this setting.</p>
<p>Methods/design: The study is a double-blind, randomised, crossover, controlled trial that will randomise 120 hypertensive subjects to 12 weeks treatment with spironolactone 50 mg once daily and 12 weeks treatment with bendroflumethiazide 2.5 mg once daily. The 2 treatment periods are separated by a 2-week washout period. Randomisation is stratified by aldosterone: renin ratio to include equal numbers of subjects with high and low aldosterone: renin ratios.</p>
<p>Primary Objective – To test the hypothesis that the aldosterone: renin ratio predicts the antihypertensive response to spironolactone, specifically that the effect of spironolactone 50 mg is greater than that of bendroflumethiazide 2.5 mg in hypertensive subjects with high aldosterone: renin ratios.</p>
<p>Secondary Objectives – To determine whether bendroflumethiazide induces adverse metabolic abnormalities, especially in subjects with high aldosterone: renin ratios and if baseline renin measurement predicts the antihypertensive response to spironolactone and/or bendrofluazide.</p>
<p>Discussion: The numerous deleterious effects of hypertension dictate the need for a systematic approach for its treatment. In spite of various therapies, resistant hypertension is widely prevalent. Among various factors, primary aldosteronism is an important cause of resistant hypertension and is now more commonly recognised. More significantly, hypertensives with primary aldosteronism are also exposed to various other deleterious effects of excess aldosterone. Hence treating hypertension with specific aldosterone antagonists may be a better approach in this group of patients. It may lead on to better blood pressures with fewer medications.</p>
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