Search results for "Concentration"
showing 10 items of 1906 documents
Early postoperative substitution procedure of the antioxidant ascorbic acid.
2005
Postoperatively reduced concentration of ascorbic acid (AA) in plasma (or =45.5 micromol/l (or =800 microg/dl)) is commonly interpreted as increased metabolic requirements, but it is not shown yet that the patient benefits from a substitution toward normal levels of AA. This is due to the missing knowledge on how to substitute AA effectively to normal plasma values in postoperative patients. Therefore, a postoperative AA substitution procedure "overnight" to normal values in plasma was investigated on a postoperative intensive care unit (ICU) in a university hospital.Fifty-seven operated patients were randomly assigned to a control- or intervention group (CG and IG, respectively). In all pa…
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 …
Improving opportunities for effective management of gastro-oesophageal reflux disease
2002
The recent introduction of proton pump inhibitors has extraordinarily improved the therapeutic approach to gastro-oesophageal reflux disease. The concept of decreasing gastric acid secretion and increasing the pH in the lower oesophagus has been demonstrated to be therapeutically effective and the higher the level of pH achieved, the better the results. In spite of the evident efficacy of these molecules, there are still many patients who will continue to have symptoms despite medical treatment. Proton pump inhibitors suppress gastric acidity, but this effect shows a remarkable interindividual variation depending on different reasons. Thus, it is still possible to optimise medical therapy f…
Endothelial Cell Swelling and Brain Perfusion
1997
Background: Whereas the contribution of glial swelling to no-reflow conditions in the ischemic penumbra or during reperfusion after global ischemia is widely discussed, little is known about cell volume control of endothelial cells under reperfusion conditions. Methods: The effect of extracellular acidosis-a key mediator of secondary brain damage-on cell volume was studied in the GM7373 endothelial cell line. Experiments were performed at pH = 6.0 in the presence or absence of bicarbonate, and during exposure to inhibitors of specific transport systems such as ethyl isopropyl amiloride or 4,4'-diisothiocyanatostilbene-2,2'-disulfonic acid. Results: Endothelial swelling to 111.1 ± 3.4% was f…
pH stability of ophthalmic solutions.
2004
Background In this study, we evaluated the pH value of 17 ophthalmic solutions, and we investigated whether the pH of these solutions changed over time after the bottle was opened. Methods Fifteen bottles of each type of solution were chosen at random from different production lots. A 0.05-ml increment was taken from each bottle and was measured daily using a micropH 2002 Crison pH-meter over a period of 30 days. Results The results revealed differences between the pH values of the solutions; nine solutions presented pH values within ocular comfort range and eight solutions presented pH values between 3.5 and 6.4. Ten solutions presented non-statistically significant variations over time ( …
Stimulatory effects of DB-c-AMP and adrenaline on myocardial contraction and 45Ca exchange. Experiments at reduced calcium concentration and low freq…
1973
The effects of adrenaline (2.2×10−6 M) and cyclic N6-2′-O-dibutyryl-adenosine-3′,5′-monophosphate (DB-c-AMP; 10−3 M) on mechanical performance, 45Ca uptake and total tissue calcium concentration were investigated in electrically stimulated left auricles isolated from female rats weighing 180–220 g. The experiments were performed at reduced [Ca]e of 0.45 mM and at various frequencies of stimulation (0–120 beats/min). In the first series of experiments 45Ca incubation time was 5 min. Under these conditions DB-c-AMP as well as adrenaline enhanced contractile force to 300–450% of the control values at all frequencies tested (Fig.1). This increase in contractile force was accompanied by a signif…
Osmolality of various viscoelastic substances: comparative study.
2000
Abstract Purpose To determine the osmolality of various viscoelastic substances. Setting Department of Ophthalmology, Johannes Gutenberg-University, Mainz, and Institute for Medical Device Testing, Memmingen, Germany. Methods The analysis was carried out according to the European Pharmacopoeia by means of a calibrated osmometer using the freezing-point depression method. Each syringe was analyzed as a duplicate analysis. Results Mean osmolalities (mOsmol/kg) of the sodium hyaluronate viscoelastic substances were Allervisc® 299; Allervisc® Plus 307; Amvisc® Plus 335; AMO Vitrax® 284; Biolon® 279; Dispasan® 311; Dispasan® Plus 314; Healon® 295; Healon GV® 312; Healon®5 322; HYA-Ophtal® 376; M…
Hyperammonemic encephalopathy after urinary diversion. Diet therapy
2016
Unpredictable Performance of pH-Dependent Coatings Accentuates the Need for Improved Predictive in Vitro Test Systems.
2017
First introduced in the second half of the 19th century, enteric coatings are commonly used to protect acid-labile drugs, reduce the risk of gastric side effects due to irritating drugs, or for local drug delivery to the lower gastrointestinal (GI) tract. The currently available enteric-coatings are based on pH-sensitive weakly acidic polymers. Despite the long history of their use, the causes behind their performance often being unpredictable have not been properly investigated with most of the attention being focused only on the gastric emptying. However, little attention has been given to the postgastric emptying disintegration and dissolution of these dosage forms. This lack of attentio…