Search results for " release"
showing 10 items of 535 documents
Role of calcineurin in Ca2+-induced release of catecholamines and neuropeptides
1998
Neurotransmission requires rapid docking, fusion, and recycling of neurotransmitter vesicles. Several of the proteins involved in this complex Ca2+-regulated mechanism have been identified as substrates for protein kinases and phosphatases, e.g., the synapsins, synaptotagmin, rabphilin3A, synaptobrevin, munc18, MARCKS, dynamin I, and B-50/GAP-43. So far most attention has focused on the role of kinases in the release processes, but recent evidence indicates that phosphatases may be as important. Therefore, we investigated the role of the Ca2+/calmodulin-dependent protein phosphatase calcineurin in exocytosis and subsequent vesicle recycling. Calcineurin-neutralizing antibodies, which blocke…
BRAIN-TARGETED SOLID LIPID NANOPARTICLES CONTAINING RILUZOLE: PREPARATION, CHARACTERIZATION AND BIODISTRIBUTION
2009
Aim: Developments within nanomedicine have revealed a great potential for drug delivery to the brain. In this study nanoparticulate systems as drug carriers for riluzole, with sufficiently high loading capacity and small particle size, were prepared to a reach therapeutic drug level in the brain. Materials & method: Solid lipid nanoparticles containing riluzole have great potential as drug-delivery systems for amyotrophic lateral sclerosis and were produced by using the warm oil-in-water microemulsion technique. The resulting systems obtained were approximately 88 nm in size and negatively charged. Drug-release profiles demonstrated that a drug release was dependent on medium pH. Biodi…
Characterization of a Ryanodine Receptor inPeriplaneta Americana
1997
Specific binding sites for the alkaloid ryanodine were characterized in membrane preparations from sarcoplasmatic reticulum of Periplaneta americana skeletal muscle. Binding of [3H]ryanodine was optimal at pH 8 and at CaCl2 concentration of about 300 mumol l-1. The Ca-chelating agents EGTA (100 mumol l-1) and EDTA (100 mumol l-1) abolished 95% and 90% of the [3H]ryanodine binding respectively. Preincubation with Ca2+ (100 mumol l-1) restored the ryanodine binding in presence of up to 300 mumol l-1 EGTA. Radioligand binding experiments showed one class of high affinity binding sites for ryanodine. Determination of rate constants revealed 7.05 x 10(6) l mol-1 min-1 for associating and 3.77 x …
OnabotulinumtoxinA: how deep will it go?
2014
First-line treatment of overactive bladder syndrome (OAB) is based on conservative measures and oral medication such asmuscarinic receptor antagonists and, more recently, b3-adrenoceptor agonists.While this provides effective symptom relief for many patients, for others it has insufficient efficacy and/or intolerable side effects. The potent neurotoxin onabotulinumtoxinA (BoNT-A) has shown efficacy in placebo-controlled trials in patients with neurogenic voiding dysfunction or OAB [1], largely including patients exhibiting an insufficient treatment response to muscarinic antagonists. Although the role of a strong placebo component in the beneficial effects of oral treatment is well known, a…
Ethanol Modulates Corticotropin Releasing Hormone Release From the Rat Hypothalamus: Does Acetaldehyde Play a Role?
2010
BACKGROUND AND METHODS Ethanol (EtOH) activates hypothalamic-pituitary-adrenal (HPA) axis, resulting in adrenocorticotropin hormone, glucocorticoid release, and in modifications of the response of the axis to other stressors. The initial site of EtOH action within the HPA system seems to be the hypothalamus. Thus, to determine the mechanisms responsible for these effects, we investigated: (i) whether EtOH was able to release corticotrophic releasing hormone (CRH) from incubated hypothalamic explants; (ii) whether acetaldehyde (ACD), its first metabolite formed in the brain by catalase activity, might play a role in EtOH activity. To this aim, rat hypothalamic explants were incubated with: (…
Extended-release guanfacine hydrochloride in 6-17-year olds with ADHD: a randomised-withdrawal maintenance of efficacy study.
2015
Background Extended-release guanfacine hydrochloride (GXR), a selective α2A-adrenergic agonist, is a nonstimulant medication for attention-deficit/hyperactivity disorder (ADHD). This phase 3, double-blind, placebo-controlled, randomised-withdrawal study evaluated the long-term maintenance of GXR efficacy in children/adolescents with ADHD. Methods Children/adolescents (6–17 years) with ADHD received open-label GXR (1–7 mg/day). After 13 weeks, responders were randomised to GXR or placebo in the 26-week, double-blind, randomised-withdrawal phase (RWP). The primary endpoint was the percentage of treatment failure (≥50% increase in ADHD Rating Scale version IV total score and ≥2-point increase …
Endoscopic carpal tunnel release: results with special consideration to possible complications.
2000
Single-portal endoscopic carpal tunnel release (Agee technique) was carried out in 148 patients. Of these, 100 were examined clinically and electrophysiologically 1 day before surgery and 1 and 3 months thereafter. Ten patients experienced transient ulnar neuropraxia and two patients complained postoperatively of intense pain in the middle and ring fingers. Three patients suffered residual symptoms. In one of these an incomplete release of the distal portion of the retinaculum flexorum was suspected and later confirmed by magnetic resonance imaging. Another patient had applied for pension due to problems associated with a vertebral fracture in addition to his carpal tunnel symptoms. A third…
Case Control Study of Neuroblastoma in West-Germany after the Chernobyl Accident
1996
Background To explore possible causes of a 1988 incidence peak of infant neuroblastoma in west German regions which were contaminated with more than 6000 Bq/m2 Cs137 from the Chernobyl accident. The primary working hypothesis was that parents of the diseased children had been contaminated by an excessive intake of locally produced food, especially mushrooms or deer. Design Case control study with 1:2 (cases:controls) matching. Data were collected from the children's parents by questionnaires and telephone interviews. Setting Nation-wide study (former FRG) based on the German Childhood Cancer Registry. Subjects Cases born in 1988 and reported with a neuroblastoma to the registry until March …
Running-induced muscle injury and myocellular enzyme release in rats
1994
The relationships and time course of exercise-induced muscle damage, estimated by beta-glucuronidase activity and microscopy, to muscle swelling, estimated by muscle water content and microscopy, and to the serum activity of creatine kinase (CK) and the concentration of carbonic anhydrase III were studied in rats 2, 12, 48, and 96 h after 90 min of intermittent running uphill (+13.5 degrees) or downhill (-13.5 degrees) at a speed of 17 m/min. The injury was more pronounced in soleus after uphill running and in the red parts of quadriceps femoris and in the white part of vastus lateralis after downhill running, whereas triceps brachii was not damaged. Increase in muscle water content preced…
[3H]-DA release evoked by low pH medium and internal H+ accumulation in rat hypothalamic synaptosomes: involvement of calcium ions
2003
The pH fluctuations have been often interpreted as an insufficient regulation or as a consequence of the onset of pathological events, such as ischemia, in which a significant decrease in pH levels occurs. Neurotransmitter release appears to be affected by pH drop significantly. In this study, we investigated the effect of an extracellular and an intracellular acidification on tritiated dopamine release ([3H]-DA release), from superfused rat hypothalamic synaptosomes. When compared to basal release, extracellular acidification, due to a reduction in the external pH of the nominally carbonic-free superfusion media, provoked a significant increase in [3H]-DA release that showed a sensitivenes…