Search results for "Techniques"
showing 10 items of 4426 documents
Glutamatergic activation of hippocampal phospholipase D: postnatal fading and receptor desensitization.
2002
Abstract: Phospholipase D (PLD) activity was determined in rat hippocampal slices between postnatal days 3 and 35. After birth, basal PLD activity was low and, within 2 weeks, increased to reach a plateau that was maintained up to the adult age. Likewise the response to glutamate developed postnatally to reach a maximum at day 8, but then faded rapidly and was almost absent at day 35. Activation of PLD by 4β-phorbol 12β,13α-dibutyrate (PDB) was independent of age, whereas the effect of aluminum fluoride (AlF4−) increased to a plateau within the first week. At day 8, PLD stimulation by glutamate via metabotropic receptors involved protein kinase C activation, but was independent of Ca2+ infl…
Effect of suturing the femoral portion of a four-strand graft during an ACL reconstruction
2014
Purpose A suture passed along the part of the graft that will be inserted into the femoral tunnel is widely used by surgeons, because it could prevent the graft sliding on the femoral fixation device during pulling from the tibial side. The aim of this study was to evaluate the biomechanical effects of suturing the intratunnel femoral part of the graft during an anterior cruciate ligament (ACL) reconstruction. Methods Bovine digital extensor tendons and tibias were harvested from 20 fresh-frozen mature bovine knees ranging in age from 18 to 24 months. Quadruple-strand bovine tendons were passed through the tibial tunnel and secured distally with a bioabsorbable interference screw. In one ha…
Different effects of pioglitazone and rosiglitazone on lipid metabolism in mouse cultured liver explants.
2010
Background Pioglitazone (PIO) and rosiglitazone (ROSI) are widely used as oral antidiabetic agents for treatment of type 2 diabetes. Although these medications exert similar effects on blood glucose, recent clinical studies indicated that PIO has a more pronounced beneficial effect on lipid parameters than ROSI. In order to get further insight into the lipid effects of both drugs, we tested whether PIO, compared to ROSI, could exert direct effects on lipid liver metabolism in relation with plasma lipids. Methods We performed in vitro studies using mice liver slices incubated 21 h either with ROSI (1 µmol/L) or PIO (7.5 µmol/L). Results We showed that both glitazones slightly reduced HMG-CoA…
Different mechanism of relaxation induced by aporphine alkaloids in rat uterus.
1993
Abstract We have examined the uterine relaxant action of three aporphine molecules (S-glaucine, S-boldine and R-apomorphine) in two experimental conditions, with and without calcium in the bathing solution, and compared these effects with those obtained with the calcium antagonists verapamil and diltiazem. The present study shows that the alkaloids relax the uterine muscle but with different mechanisms of action. In Ca2+-containing solution all three alkaloids relaxed the uterus previously contracted by KCl or acetylcholine, but in Ca2+-free medium only R-apomorphine was able to relax oxytocin-induced contraction. The calcium antagonists, verapamil and diltiazem, relaxed KCl- or acetylcholi…
Effects of polymorphisms in endothelial nitric oxide synthase and folate metabolizing genes on the concentration of serum nitrate, folate, and plasma…
2015
Abstract Objectives A number of studies have explored the effects of dietary nitrate on human health. Nitrate in the blood can be recycled to nitric oxide, which is an essential mediator involved in many important biochemical mechanisms. Nitric oxide is also formed in the body from l -arginine by nitric oxide synthase. The aim of this study was to investigate whether genetic polymorphisms in endothelial nitric oxide synthase (eNOS) and genes involved in folate metabolism affect the concentration of serum nitrate, serum folate, and plasma total homocysteine in healthy individuals after folic acid supplementation. Methods In a randomized double-blind, crossover study, participants were given …
The effect of two sulphur-containing pesticides, fenitrothion and endosulfan, on glutathione (GSH) content and on GSH S-transferase and gamma-glutamy…
1988
The glutathione (GSH) system of Procambarus clarkii (P.c.), the American red crayfish, is used as a marker of the effects of Fenitrothion (FT) and Endosulfan (ES), organophosphorus and organochlorinated insecticides, respectively. This system has been shown to be sensitive to different heavy metals poisoning, thus it has a double interest as marker for environmental contamination and as a potential source of xenobiotics or their metabolites to humans, since it is being fished commercially. The GSH content of the organ decreased 24 h after treatment with FT. FT promotes a 2-fold induction of GSH S-transferase (GST) activity at 6 h which is followed by a decrease of it at 24 h. The latter coi…
3D reconstruction techniques made easy: know-how and pictures
2005
Three-dimensional reconstructions represent a visual-based tool for illustrating the basis of three-dimensional post-processing such as interpolation, ray-casting, segmentation, percentage classification, gradient calculation, shading and illumination. The knowledge of the optimal scanning and reconstruction parameters facilitates the use of three-dimensional reconstruction techniques in clinical practise. The aim of this article is to explain the principles of multidimensional image processing in a pictorial way and the advantages and limitations of the different possibilities of 3D visualisation.
Analysis of the hyperpolarizing effects of forskolin in guinea-pig atrial heart muscle.
1988
The effects of forskolin on action potential configuration and on both uptake and efflux of 86Rb+ were studied in guinea-pig left atria. The action potential was prolonged by forskolin in the plateau range but shortened at the end of repolarization; maximal upstroke velocity and amplitude of slow response potentials were enhanced. In partially depolarized preparations, the resting potential was increased by forskolin; this effect was not prevented by atropine 1 μmol/1. Forskolin augmented the rate constant of 86Rb+ efflux in beating and in resting preparations. The uptake of 86Rbs+ was enhanced by forskolin in resting preparations. It is concluded that forskolin stimulates the Na+, K+ -pump…
Dithiothreitol prevents age-associated decrease in oocyte/conceptus viability in vitro.
1998
The present study was designed to ascertain whether the negative effects on reproductive potential of post-ovulatory ageing in vitro of oocytes can be prevented by antioxidant therapy. Mouse metaphase II (MII) oocytes were aged in vitro for 12 h prior to insemination in the presence of varying concentrations of L-ascorbic acid, 6-methoxy-2,5,7,8-tetramethylchromane-2-carboxylic acid (Trolox), L-cystine dihydrochloride, ethylenediaminetetraacetic acid (EDTA), beta-mercaptoethanol and DL-dithiothreitol (DTT). In-vitro ageing of oocytes was associated with lower fertilization rate, higher proportion of concepti exhibiting cellular fragmentation at 24 h post-insemination and lower percentage of…
Comparison of biometric measurements using partial coherence interferometry and applanation ultrasound
2003
Abstract Purpose To compare and contrast axial length (AL) measurements assessed by ultrasound biometry and optical biometry. Setting Department of Ophthalmology, Johannes Gutenberg-University, Mainz, Germany. Methods Optical biometry and ultrasound biometry were performed in 360 eyes to measure AL. Results In eyes with a clear-appearing crystalline lens, there was a statistically significant median difference in AL measurements between the 2 methods in eyes with a normal or long length. In eyes with cataract, there was a statistically significant median difference in AL measurements in eyes with a normal or short length. In these cases, optical biometry produced larger readings than ultras…