12 research outputs found
Effect of colchicine on physiological and biochemical properties of <i>Rhodococcus qingshengii</i>
The genus Rhodococcus includes polymorphic non-spore-forming gram-positive bacteria belonging to the class Actinobacteria. Together with Mycobacterium and Corynebacterium, Rhodococcus belongs to the Mycolata group. Due to their relatively high growth rate and ability to form biof ilms, Rhodococcus are a convenient model for studying the effect of biologically active compounds on pathogenic Mycolata. Colchicine was previously found to reduce biof ilm formation by P. carotovorum VKM B-1247 and R. qingshengii VKM Ac-2784D. To understand the mechanism of action of this alkaloid on the bacterial cell, we have studied the change in the fatty acid composition and microviscosity of the R. qingshengii VKM Ac-2784D membrane. Nystatin, which is known to reduce membrane microviscosity, is used as a positive control. It has been found that colchicine at concentrations of 0.01 and 0.03 g/l and nystatin (0.03 g/l) have no signif icant effect on the survival of R. qingshengii VKM Ac-2784D cultivated in a buffered saline solution with 0.5 % glucose (GBSS). However, colchicine (0.03 g/l) signif icantly inhibits biof ilm formation. Rhodococcus cells cultivated for 24 hours in GBSS with colchicine acquire a rounded shape. Colchicine at 0.01 g/l concentration increases C16:1(n-7), C17:0, C20:1(n-9) and C21:0 fatty acids. The microviscosity of the membrane of individual cells was distributed from the lowest to the highest values of the generalized laurdan f luorescence polarization index (GP), which indicates a variety of adaptive responses to this alkaloid. At a higher concentration of colchicine (0.03 g/l) in the membranes of R. qingshengii VKM Ac-2784D cells, the content of saturated fatty acids increases and the content of branched fatty acids decreases. This contributes to an increase in membrane microviscosity, which is conf irmed by the data on the GP fluorescence of laurdan. All of the above indicates that colchicine induces a rearrangement of the Rhodococcus cell membrane, probably in the direction of increasing its microviscosity. This may be one of the reasons for the negative effect of colchicine on the formation of R. qingshengii VKM Ac-2784D biof ilms
Influence of exogenous NO donator and variations in the Ca2+ content on transport activity related to tonoplast proton pumps in ontogenesis and under hyperosmotic stress
The effect of dihydroquercetin on active and passive ion transport systems in plant vacuolar membrane
The dynamics of hormonal status of developing red beet root (Beta vulgaris L.) in correlation with the dynamics of sugar accumulation
Proteins as Morphogenetic Markers in Callus Cultures of Buckwheat Fagopyrum tataricum (L.) Gaertn with Different Morphogenetic Potential
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Global taxonomic, functional, and phylogenetic diversity of bees in apple orchards
An essential prerequisite to safeguard pollinator species is characterisation of the multifaceted diversity of crop pollinators and identification of the drivers of pollinator community changes across biogeographical gradients. The extent to which intensive agriculture is associated with the homogenisation of biological communities at large spatial scales remains poorly understood. In this study, we investigated diversity drivers for 644 bee species/morphospecies in 177 commercial apple orchards across 33 countries and four global biogeographical biomes. Our findings reveal significant taxonomic dissimilarity among biogeographical zones. Interestingly, despite this dissimilarity, species from different zones share similar higher-level phylogenetic groups and similar ecological and behavioural traits (i.e. functional traits), likely due to habitat filtering caused by perennial monoculture systems managed intensively for crop production. Honey bee species dominated orchard communities, while other managed/manageable and wild species were collected in lower numbers. Moreover, the presence of herbaceous, uncultivated open areas and organic management practices were associated with increased wild bee diversity. Overall, our study sheds light on the importance of large-scale analyses contributing to the emerging fields of functional and phylogenetic diversity, which can be related to ecosystem function to promote biodiversity as a key asset in agroecosystems in the face of global change pressures
Effect of rosiglitazone on the frequency of diabetes in patients with impaired glucose tolerance or impaired fasting glucose: a randomised controlled trial
Background Rosiglitazone is a thiazolidinedione that reduces insulin resistance and might preserve insulin secretion. The aim of this study was to assess prospectively the drugs ability to prevent type 2 diabetes in individuals at high risk of developing the condition
the European trial on Reduction of Cardiac Events with Perindopril in Stable Coronary Artery Disease Investigators. Efficacy of perindopril in reduction of cardiovascular events among patients with stable coronary artery disease: randomised, double-blind, placebo-controlled, multicentre trial (the EUROPA trial).
Background Treatment with angiotensin-converting-enzyme
(ACE) inhibitors reduces the rate of cardiovascular events
among patients with left-ventricular dysfunction and those at
high risk of such events. We assessed whether the ACE
inhibitor perindopril reduced cardiovascular risk in a low-risk
population with stable coronary heart disease and no apparent
heart failure.
Methods We recruited patients from October, 1997, to June,
2000. 13 655 patients were registered with previous
myocardial infarction (64%), angiographic evidence of coronary
artery disease (61%), coronary revascularisation (55%), or a
positive stress test only (5%). After a run-in period of 4 weeks,
in which all patients received perindopril, 12 218 patients
were randomly assigned perindopril 8 mg once daily (n=6110),
or matching placebo (n=6108). The mean follow-up was
4·2 years, and the primary endpoint was cardiovascular death,
myocardial infarction, or cardiac arrest. Analysis was by
intention to treat.
Findings Mean age of patients was 60 years (SD 9), 85% were
male, 92% were taking platelet inhibitors, 62% blockers, and
58% lipid-lowering therapy. 603 (10%) placebo and 488 (8%)
perindopril patients experienced the primary endpoint, which
yields a 20% relative risk reduction (95% CI 9–29, p=0·0003)
with perindopril. These benefits were consistent in all
predefined subgroups and secondary endpoints. Perindopril
was well tolerated.
Interpretation Among patients with stable coronary heart
disease without apparent heart failure, perindopril can
significantly improve outcome. About 50 patients need to be
treated for a period of 4 years to prevent one major
cardiovascular event. Treatment with perindopril, on top of
other preventive medications, should be considered in all
patients with coronary heart disease