Sarcoplasmic reticular Ca2+-ATPase inhibition paradoxically upregulates murine skeletal muscle Nav1.4 function

Skeletal muscle Na+ channels possess Ca2+- and calmodulin-binding sites implicated in Nav1.4 current (INa) downregulation following ryanodine receptor (RyR1) activation produced by exchange protein directly activated by cyclic AMP or caffeine challenge, effects abrogated by the RyR1-antagonist dantrolene which itself increased INa. These findings were attributed to actions of consequently altered cytosolic Ca2+, [Ca2+]i, on Nav1.4. We extend the latter hypothesis employing cyclopiazonic acid (CPA) challenge, which similarly increases [Ca2+]i, but through contrastingly inhibiting sarcoplasmic reticular (SR) Ca2+-ATPase. Loose patch clamping determined Na+ current (INa) families in intact native murine gastrocnemius skeletal myocytes, minimising artefactual [Ca2+]i perturbations. A bespoke flow system permitted continuous INa comparisons through graded depolarizing steps in identical stable membrane patches before and following solution change. In contrast to the previous studies modifying RyR1 activity, and imposing control solution changes, CPA (0.1 and 1 µM) produced persistent increases in INa within 1–4 min of introduction. CPA pre-treatment additionally abrogated previously reported reductions in INa produced by 0.5 mM caffeine. Plots of peak current against voltage excursion demonstrated that 1 µM CPA increased maximum INa by ~ 30%. It only slightly decreased half-maximal activating voltages (V0.5) and steepness factors (k), by 2 mV and 0.7, in contrast to the V0.5 and k shifts reported with direct RyR1 modification. These paradoxical findings complement previously reported downregulatory effects on Nav1.4 of RyR1-agonist mediated increases in bulk cytosolic [Ca2+]. They implicate possible local tubule-sarcoplasmic triadic domains containing reduced [Ca2+]TSR in the observed upregulation of Nav1.4 function following CPA-induced SR Ca2+ depletion.

DETEKSI DINI KEBUNTINGAN PADA SAPI BALI MENGGUNAKAN ASAM SULFAT (H2SO4).

The purpose of this study was to determine the appropriate dosage, time and method of diagnosing pregnancy in Balinese cattle using a mixture of urine and aquadest which was reacted with Sulfuric Acid (H2SO4). This research was conducted in February - March 2018 in Bongo village, Wonosari sub-district, Boalemo Regency, Gorontalo Province. The material used is urine urine samples, which have been artificially inseminated. Concentrated sulfuric acid (H2SO4) of 0.3 ml, 0.5 ml, 0.7 ml, 0.9 and 0.11 ml (according to treatment). The variables observed were fluorescence gas in solution, change in color of solution, time of change in solution. Data were analyzed using unidirectional variance analysis. The results showed pregnancy detection in Balinese cows who had been on IB in each treatment gave a very significant effect (P 0.01. The results of the BNT test revealed that the age of 6 days had the fastest time in detecting pregnancy with ± 6 seconds, at age 11 and 16 days have the fastest time in detecting pregnancy, with an average time of ± 5 seconds the pregnancy can be detected.

PENETAPAN KADAR SURFAKTAN ANIONIK PADA DETERJEN CUCI CAIR SECARA METODE TITRIMETRI

Washing liquid detergent is a one type clothes are cleaning needed by the community, good by the household, industry, hospitality, restaurant and others. One type of component in liquid washing detergent is a anionic surfactant. Based on SNI 06-4075-1996 concerning Liquid Wash Detergents, the minimum quality requirement for anionic surfactants levels is 15% - 35%. Analysis the surfactant anionic levels of this experiment take method titrimetry. Principal on method titrimetry speficially, anionics surfactants with text example hydrolyzed with sulfuric acid form cationic and anionic mixture. Anionics surfactants derived from results reaction between the ethanol and sulfuric acid which sulfuric ethanol. Titration with sulfuric acids until the color solution change from pink to bluish gray. Anionic surfactants levels the which obtained from each example of A-D in a row is a 17,43%, 7,64%; 8,89%; 8,64%. Anionics Surfactants that is a satisfy the meminimum quality requirement, namely 15%-35%.

Risk Factors and Consequences of Hyperaluminemia in a Peritoneal Dialysis Cohort

♦ BackgroundWidespread Al toxicity is unusual today. In 2005, Canadian peritoneal dialysis (PD) centers reported widespread hyperaluminemia in patients using dialysates from one specific manufacturer. Our objectives were to evaluate risk factors related to Al accumulation and to assess its clinical consequences in patients from 2 centers.♦ MethodsA retrospective closed cohort study was conducted in patients treated with PD in May 2005. A multivariate linear regression model was constructed to identify variables associated with a higher serum Al level in the exposed group at the moment of solution change. Using appropriate statistical methods, anemia and bone metabolism parameters were compared between the exposed and unexposed groups. Time to first peritonitis was estimated by the Kaplan–Meier method.♦ ResultsThe study cohort included 87 Al-exposed patients and 95 unexposed patients. In the exposed group, serum Al at the moment of solution change was influenced by the length of exposure to Al-containing dialysates and by PD creatinine clearance; serum Al was inversely correlated with renal creatinine clearance. No consequences of Al accumulation were observed. No difference was observed in the time to first peritonitis between patients who switched manufacturers and those who remained with the original manufacturer.♦ ConclusionsOur results suggest that hyperaluminemia is directly related to the length and extent of exposure to Al-containing dialysates; residual renal function is protective against Al accumulation. Because the problem was detected rapidly, no clinical consequences of hyperaluminemia were observed in the study cohort.

Nursing Leader: Mary O. Mundinger

Dr. Mary O. Mundinger was one of the earliest leaders in the proposal and creation of the doctor of nursing practice (DNP) degree. She is a prime model of an effective nurse leader. By her example, nursing leaders should carefully diagnose organizational problems, commit to making forward movement, and invest in others to sustain the solution. Change must include both passion and endurance. Allies with power and influence move the issue beyond where one could take it through sheer will alone. The purpose of this article is to discuss a single change agent and to use this analysis as a springboard for beginning leadership development.

Durability of a Drag Reducing Solution

Effectiveness of drag reduction by small addition of a surfactant in the turbulent flow of water depends on the structure and concentration of the additive, temperature of the solution and turbulence intensity, possible flow disturbance by a mechanical obstacle and the content of ions in water, but also on the age of the surfactant solution. We show how important aging effects are in connection with total surfactant concentration, in particular how rheological parameters of the drag reducing solution change with time.

Effect of Polymerization of Precursor Solutions on Crystallization and Morphology of Ce0.9Gd0.1O1.95 Powders

ABSTRACTSynthesis of Ce0.9Gd0.1O1.95 (CGO) powders from polymeric precursor solutions formed by mixing nitrates and ethylene glycol at 60-85 was investigated with emphasis on the effect of the polymerization of the precursor solution on the crystallization and morphology of the derived intermediate and the resultant oxide powders. It was revealed by FTIR that the molecular structures of the polymeric precursor solution change from aldehyde or ketone groups to carboxylic acid and carboxylate groups with increasing heating time. TG-DTA analyses demonstrated the temperature shifting and the disappearance of the exothermic reactions of the derived powders with different heating times of the polymeric precursor solutions. Furthermore, it was identified by XRD, SEM and TEM that the derived powders can be changed from well crystallized organic formates of Ce1-xGdx(HCOO)3 with dendritic growth to loose agglomerated cubic CGO powders with grain sizes below 10 nm.

Uptake Patterns of 11 Elements of Orange Trees in Solution Culture

Three trees each of `Valencia' orange (Citrus sinensis L. Osbeck) on rough lemon (C. limon L. Burm. f.) rootstocks that had been grown in solution culture since July 1989 were grown in two solutions from Oct. 1995 to Sept.1996. Solution 1 was a soil extract made by boiling field soil (1:2 soil:water) for 20 min and filtering. Solution 2 was a complete nutrient solution. The solutions were analyzed every 7 days and changed every 28 days. At each solution change, the newly prepared solutions were analyzed for 11 elements and their depletion was determined by weekly analysis. Nearly all the N, K, and Mn in Solution 1 was absorbed in the first 7 days after each solution change; in Solution 2, N and Mn were also absorbed in 7 days, but K absorption was variable; single trees sometimes needed 4 weeks to absorb all the potassium. Calcium and Mg were never completely absorbed and in contrast to Mn, traces of Fe, Zn, and Cu remained in both solutions after 4 weeks.

Depolarization-induced Ca entry via Na-Ca exchange triggers SR release in guinea pig cardiac myocytes

In mammalian heart muscle, Ca entry through L-type Ca channels is thought to be the primary trigger for the sarcoplasmic reticulum (SR) Ca release, which initiates contraction. The results of this study show that, in guinea pig myocytes with a normal internal Na (10 mM Na in pipette), another trigger mechanisms for SR release and contraction exists. A crucial feature of these experiments was the ability to change rapidly the extracellular environment of a single myocyte so that alterations of intracellular Ca and SR Ca load were minimized for each solution change. We found the following results. 1) A switch to Na-free solution 50 ms before depolarization led to an increase of phasic contraction without increasing L-type Ca current (Ica) or Ca loading of the SR. 2) Although rapid application of 20 microM nifedipine 3 s before a + 10-mV pulse blocked ICa completely, 43 +/- 11 (SE) % of the phasic contraction remained. Similar results were obtained by rapid switching to 150 microM Cd to block ICa. 3) Phasic contraction and ICa had different voltage dependence. With steps to positive potentials there was little ICa but still a substantial phasic contraction. 4) Under action potential conditions, 64.6 +/- 7.9% of the control phasic contraction remained after switching to 20 microM nifedipine to block ICa. 5) The contraction remaining with nifedipine was unaffected by adding 100 microM Ni. Because 100 microM Ni blocks T-type Ca channels, this shows that Ca entry via T-type Ca channels is not involved in triggering SR release. 6) The phasic contraction remaining after a rapid switch to nifedipine was blocked completely by adding 5 mM Ni. Because this concentration of Ni is known to block the Na-Ca exchange, this result suggests that the exchange plays a role in triggering SR release. Taken together, the present results indicate that depolarization-induced Ca entry on the Na-Ca exchange is able to trigger SR release and phasic contraction. This explanation can account for increased phasic contraction after a rapid switch to Na-free solution, persistence of a phasic contraction in the complete absence of ICa, substantial phasic contraction at positive test potentials where there is no ICa, and abolition of nifedipine-resistant contraction by 5 mM Ni.

Nutrient Composition of Sweetpotato Storage Roots Altered by Frequency of Nutrient Solution Change

The sweetpotato [Ipomoea batatas (L.) Lam] breeding clone TU-82-155 was grown during Spring 1990 and Summer 1991 in standard Tuskegee Univ. (Alabama) growth channels (0.15 × 0.15 × 1.2 m) for 120 days in a greenhouse using a hydroponic (nutrient film) system with a modified half-strength Hoagland nutrient solution. The nutrient solution was changed every 2, 14, or 28 days. Total N, oil, ash, amino acid, vitamin, and mineral concentrations in storage roots generally were higher and dry weight and starch concentration were lower with 2-day solution changes than with those less frequent.