Search results for "Potassium"
showing 10 items of 930 documents
Photo-induced chemiluminometric determination of Karbutilate in a continuous-flow Multicommutation assembly
2006
The present paper deals with the chemiluminescent determination of the herbicide Karbutilate on the basis of its previous photodegradation by using a low-pressure Hg lamp as UV source in a continuous-flow multicommutation assembly (a solenoid valves set). The pesticide solution was segmented by a solenoid valve and sequentially alternated with segments of the 0.001 mol l(-1) of NaOH solution, the suitable media for the formation of photo-fragments; then it passes through the photo-reactor and was lead to the flow-cell after being divided in small segments which were sequentially alternated with the oxidizing system; 2 x 10(-5) mol l(-1) of potassium permanganate in 0.2% pyrophosphoric acid.…
Novel missense mutation in the ATP1A2 gene associated with atypical sporapedic hemiplegic migraine
2019
Hemiplegic migraine (HM) is a rare subtype of migraine with aura in which attacks include transient motor weakness or hemiparesis that can last several days. HM is linked to mutations in three different genes, CACNA1A, ATP1A2 and SCN1A, which encode for ion transporters. The clinical spectrum includes atypical symptoms such as impaired consciousness, epileptic seizures, permanent cerebellar ataxia or mental retardation. We describe a novel mutation found in the ATP1A2 gene in a patient with late-onset HM. His attacks were characterised by motor weakness associated with altered mental status, diplopia and ataxia. He also showed up MRI abnormalities and incomplete response to prophylactic the…
Xenon Improves Neurologic Outcome and Reduces Secondary Injury Following Trauma in an In Vivo Model of Traumatic Brain Injury*
2014
Objectives: To determine the neuroprotective efficacy of the inert gas xenon following traumatic brain injury and to determine whether application of xenon has a clinically relevant therapeutic time window. Design: Controlled animal study. Setting: University research laboratory. Subjects: Male C57BL/6N mice (n = 196). Interventions: Seventy-five percent xenon, 50% xenon, or 30% xenon, with 25% oxygen (balance nitrogen) treatment following mechanical brain lesion by controlled cortical impact. Measurements and Main Results: Outcome following trauma was measured using 1) functional neurologic outcome score, 2) histological measurement of contusion volume, and 3) analysis of locomotor functio…
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 …
Inhibitory effects of N-valproyl-L-tryptophan on high potassium, low calcium and low magnesium-induced CA1 hippocampal epileptiform bursting activity…
2012
N-valproyl-l-tryptophan (VPA-Tryp), new antiepileptic drug, was tested on CA1 hippocampal epileptiform bursting activity obtained by increasing potassium and lowering calcium and magnesium concentrations in the fluid perfusing rat brain slices. Each slice was treated with a single concentration (0.2, 0.5, 1 or 2 mM) of Valproate (VPA) or VPA-Tryp. Both burst duration and interburst frequency during and after treatment were off-line compared with baseline values. For both parameters, the latency and the length of statistically significant response periods as well as the magnitude of drug-induced responses were calculated. VPA-Tryp evoked fewer and weaker early excitatory effects than VPA on …
CA125-Guided Diuretic Treatment Versus Usual Care in Patients With Acute Heart Failure and Renal Dysfunction
2020
BACKGROUND: The optimal diuretic treatment strategy for patients with acute heart failure and renal dysfunction remains unclear. Plasma carbohydrate antigen 125 (CA125) is a surrogate of fluid overload and a potentially valuable tool for guiding decongestion therapy. The aim of this study was to determine if a CA125-guided diuretic strategy is superior to usual care in terms of short-term renal function in patients with acute heart failure and renal dysfunction at presentation. METHODS: This multicenter, open-label study randomized 160 patients with acute heart failure and renal dysfunction into 2 groups (1:1). Loop diuretics doses were established according to CA125 levels in the CA125-gui…
Increased contraction to noradrenaline by vasopressin in human renal arteries
2002
Arginine vasopressin (AVP) not only acts directly on blood vessels through vasopressin V1 receptor stimulation but also may modulate adrenergic-mediated responses in animal experiments. The aim of the present study was to assess whether subpressor concentrations of AVP could contribute to an abnormal adrenergic contractile response of human renal arteries.Renal artery rings were obtained from 27 patients undergoing nephrectomy. The rings were suspended in organ bath chambers for isometric recording of tension.AVP (10(-10) mol/l) and the vasopressin V1 receptor agonist [Phe2, Orn8]-vasotocin (10(-10) mol/l) produced a leftward shift of the concentration-response curve to noradrenaline (half-…
SODIUM FRACTION EXCRETION RATE IN NOCTURNAL ENURESIS CORRELATES WITH NOCTURNAL POLYURIA AND OSMOLALITY
2004
Abstract: Purpose: We verify the sodium fraction excretion rate (FE Na) and potassium fraction excretion WE K) rates in monosymptomatic nocturnal enuresis. We also correlate FE Na and FE K to urinary osmolality, nocturnal polyuria and vasopressin in the same population. Materials and Methods: A total of 438 children 6 to 15 years old (mean age 9.7) presenting with monosymptomatic nocturnal enuresis were recruited from different centers. Inclusion criteria were 3 or greater wet nights a week, no daytime incontinence and no treatment in the previous 2 months. Exclusion criteria were cardiopathy, endocrinopathy, psychiatric problems and urinary tract abnormalities. Micturition chart, diurnal (…
A1 receptors mediate adenosine inhibitory effects in mouse ileum via activation of potassium channels.
2008
Abstract Aims We investigated the effects induced by exogenous adenosine on the spontaneous contractile activity of the longitudinal muscle of a mouse ileum, the receptor subtypes activated, the involvement of enteric nerves and whether opening of K + channels was a downstream event leading to the observed effects. Main methods Mechanical responses of the mouse ileal longitudinal muscle to adenosine were examined in vitro as changes in isometric tension. Key findings Adenosine caused a concentration-dependent reduction of the spontaneous contraction amplitude of the ileal longitudinal muscle up to its complete disappearance. This effect induced was markedly reduced by an A 1 receptor antago…
Current and birth weights exert independent influences on nocturnal pressure-natriuresis relationships in normotensive children.
1998
The objective was to study the impact of birth weight on the relationship between ambulatory blood pressure and urinary sodium excretion in children and adolescents. The study included 134 healthy children (61 boys), all Caucasians, who were born at term after a normotensive pregnancy. For each subject, a 24-hour ambulatory blood pressure monitoring and a complete urine collection were simultaneously performed according to the protocols designed. Average ambulatory blood pressure (BP) and the urinary excretion rates for sodium, potassium, and creatinine were calculated separately for 24-hour, awake, and sleep periods defined by a mini-diary. The excretion rate of sodium during sleep time w…