Potassium Loading Research Articles

Simultaneous soot combustion and nitrogen oxides storage on potassium-promoted hydrotalcite-based CoMgAlO catalysts

A series of potassium-promoted hydrotalcite-based CoMgAlO mixed oxide catalysts used for simultaneous soot combustion and nitrogen oxides storage were prepared by impregnation method. The techniques of TG/DTA, XRD, H 2-TPR and in situ DRIFTS were employed for catalyst characterization. Over the catalyst containing 7.5% or 10% K, the soot ignition temperature ( T i = 260 °C) and total removal temperature ( T f = 390 °C) are decreased by 180 °C and 273 °C, respectively, as compared with the uncatalyzed reaction. The results of kinetic calculation show that the presence of K-promoted catalysts decreases the activation energy of soot combustion from 207 kJ/mol to about 160 kJ/mol. When 400 ppm NO is introduced, lower characteristic temperatures or higher reaction rate for soot oxidation is achieved. Simultaneously, relatively larger nitrogen oxides storage capacity is obtained. It is revealed by H 2-TPR that the addition of K increases the amount of active Co sites and the mobility of bulk lattice oxygen due to the low melting point of K-containing compounds, the low valence of K + and the strong interaction between K and Mg(Al). For nitrogen oxides storage, different routes via chelating bidentate nitrates, monodentate nitrates and ionic nitrates are confirmed by in situ DRIFTS over the CoMgAlO catalysts with potassium loadings of 0, 1.5 and 7.5%, respectively.

Urinary Kallikrein and Blood Pressure – Gender-Different Response to Potassium Supplementation in SHR

Aims: To test whether blood pressure is affected by potassium supplementation which modifies urinary kallikrein (UK) in SHR of either sex, and to elucidate the mechanisms involved. Design: In SHR and WKY blood pressure, renal function and hormonal profile were studied after 1% oral potassium supplementation starting at 4 weeks of age and throughout until 12 weeks of age. Results were compared with those of untreated SHR and WKY of either sex. Results: Systolic blood pressure (mm Hg) started to rise in SHR and was significantly different at 6–8 weeks of age: 153.5 ± 7.9 versus 100 ± 5.6 in female and 157 ± 7.7 versus 98.4 ± 6.8 in male rats (p < 0.01). Systolic blood pressure increased progressively in female and male rats reaching 164.5 ± 4.8 and 204.5 ± 7.6, respectively, at 12 weeks of age. At this time systolic blood pressure was higher in male than in female SHR (p < 0.01) and UK activity (UKa; nkat/day/100 g body weight) was slightly lower in male SHR. After 1% oral potassium supplementation administered from 4 to 12 weeks of age, a decrease in systolic blood pressure was seen in male SHR: 204.5 ± 7.6 versus 173.5 ± 7.9 (p < 0.05); and 164.5 ± 4.8 versus 156.8 ± 5.5 in female rats (NS) at 12 weeks of age, concomitant with an increase in UKa, particularly in male rats (29.35 ± 1.92 versus 36.54 ± 2.61, p < 0.05). As expected, plasma aldosterone (pg/ml), increased markedly after potassium treatment from 129 ± 31.4 in untreated female and male SHR and WKY to 528 ± 180.7 in SHR and 473 ± 88.4 in WKY (p < 0.05 in both cases). After potassium supplementation, potassium excretion was significantly correlated with both aldosterone levels and UKa (p < 0.001 in both cases). No significantly concurrent changes in plasma renin activity were observed, but instead a significant decrease was seen in SHR (p < 0.01). The potassium blood pressure-lowering effect was blunted by aldosterone receptor antagonist treatment that also decreased UKa from 36.5 ± 2.61 to 19.5 ± 1.9, particularly in male SHR. No attempt was made in this experimental setting to block kallikrein or kinin receptors. Conclusions: UKa increases as a consequence of aldosterone stimulation by potassium load since an aldosterone receptor blockade abolishes UKa increment and blood pressure fall. These results further support the hypothesis that the kallikrein kinin system plays a role in blood pressure regulation and they also show a gender different response to potassium load in relation to UKa and blood pressure.

Aldosterone‐dependent and ‐independent effects on renal potassium excretion

Aldosterone (aldo) is released from adrenal glands upon potassium (K) loading and hyperkalemia. It stimulates renal K excretion via the ROMK K‐channel and via activation of the apical epithelial sodium channel (ENaC) providing the electrochemical driving force for K secretion. Previous studies using adrenalectomized rodent models showed that both aldo‐dependent and ‐independent effects are important for renal K excretion. Here we characterized a mouse model lacking aldosterone synthase and thus endogenous aldo production. Under basal conditions, KO mice are slightly hyperkalemic but excrete similar quantities of K with urine as WT mice. K loading with food (3% and 5% for 2 days) induced kaliuresis in WT and KO mice. KO mice excreted a 3–4 fold higher volume of diluted urine after 5% K‐loading and were mildly hyperkalemic. Immunohistochemistry revealed that K‐loading (3% K) induced a translocation of ROMK and ENaC from intracellular compartments to the apical membrane of the renal collecting system in WT mice. While the translocation of ENaC was lacking, the translocation of ROMK was even more pronounced in KO mice. Thus, the renal adaptation to K‐loading involves an aldo‐dependent translocation of ENaC and an aldo‐independent translocation of ROMK. This defect is likely compensated by increased apical targeting of ROMK, a higher urinary flow and reduced concentration of urine, which possibly increases flow‐stimulated K secretion and prevents life‐threatening hyperkalemia.

Synthesis and Application of Quantum Dot-Tagged Fluorescent Microbeads

Direct reaction of herringbone, platelet, or narrow, tubular herringbone graphitic carbon nanofibers (GCNFs) with molten potassium gives K/GCNF intercalates with stoichiometric control of potassium loading. Intercalate formation is confirmed by powder X-ray diffraction and micro-Raman spectroscopy. K/GCNF intercalates act as radical-anion alkene polymerization catalysts and reduce water with stoichiometric formation of hydrogen gas. Stage-1 K/narrow, tubular GCNF intercalate exhibits thermionic emission at 300 degrees C. Stage-1 K/herringbone GCNF intercalate is an excellent thermionic emitter having high thermal stability up to 1000 degrees C. K/GCNF intercalates have much reduced work functions of ca. 2.2 eV with localized emission showing a work function of 1.6 eV.

Adverse Effects of Sodium Chloride on Bone in the Aging Human Population Resulting from Habitual Consumption of Typical American Diets , ,

A typical American diet contains amounts of sodium chloride far above evolutionary norms and potassium far below those norms. It also contains larger amounts of foods that are metabolized to noncarbonic acids than to organic bases. At baseline, in a steady state, diets that contain substantial sodium chloride and diets that are net acid producing each independently induce and sustain increased acidity of body fluid. With increasing age, the kidney’s ability to excrete daily net acid loads declines, invoking homeostatically increased utilization of base stores (bone, skeletal muscle) on a daily basis to mitigate the otherwise increasing baseline metabolic acidosis, which results in increased calciuria and net losses of body calcium. Those effects of net acid production and its attendant increased body fluid acidity may contribute to development of osteoporosis and renal stones, loss of muscle mass, and age-related renal insufficiency. The inverted ratio of potassium to sodium in the diet compared with preagricultural diets affects cardiovascular function adversely and contributes to hypertension and stroke. The diet can return to its evolutionary norms of net base production inducing low-grade metabolic alkalosis and a high potasium-to-sodium ratio by 1) greatly reducing content of energy-dense nutrient-poor foods and potassium-poor acid-producing cereal grains, which would entail increasing consumption of potassium-rich net base-producing fruits and vegetables for maintenance of energy balance, and 2) greatly reducing sodium chloride consumption. Increasingly, evidence supports the health benefits of reestablishing evolutionary norms of dietary net base loads and high potassium and low sodium chloride loads. We focus here on the American diet’s potential effects on bone through its superphysiologic content of sodium chloride.

An unusual case of acute hyperkalemia during pregnancy

We report a rare case of acute hyperkalemia in a patient with chronic kidney disease and intrauterine fetal demise. We propose that the hyperkalemia was due to a potassium load introduced into the maternal circulation as a result of intrauterine fetal demise and uterine rupture.

Potassium Effects on Activated-Carbon-Supported Iron Catalysts for Fischer−Tropsch Synthesis

The effect of potassium on the activity, selectivity, and distribution of products (hydrocarbons and oxygenates) was studied over iron catalysts supported on activated carbon (AC) for Fischer−Tropsch synthesis (FTS). This is part of a wider study on the incremental effects of components (including the support) of a multicomponent (Fe−Cu−Mo−K/AC) FTS catalyst. The range of potassium loading used was 0−2 wt %. A fixed-bed reactor was used under the conditions of 260−300 °C, 300 psig, and 3 Nl/g cat/h, using syngas with a H2/CO molar feed ratio of 0.9. Both FTS and water−gas shift activities increase after the addition of 0.9 wt % potassium, whereas an opposite trend is observed with the addition of 2 wt % potassium. This is shown to be the result of interaction between the decrease of both the activation energy (Ea) and the pre-exponental factor (k0) with the amount of potassium promoter added. Detectable hydrocarbons up to C34 and oxygenates up to C5 are formed on the Fe/AC catalysts with or without potass...

Processing of stored packed red blood cells using autotransfusion devices decreases potassium and microaggregates: a prospective, randomized, single‐blinded in vitro study

The aim of the study was to compare the potential of autotransfusion devices to reduce non-infectious complications related to transfusion of long-stored packed red blood cells (PRBC; n= 57), such as changes in electrolytes, blood cells and the load of free microaggregates. Following a baseline measurement, a blood pool of three PRBC was divided into three equal volumes and washed with either the Haemonetics Cell Saver (HCS) or the continuous autotransfusion system (C.A.T.S), using the quality (CATS(quality)) and emergency (CATS(emergency)) mode. After the washing procedure, measurements for electrolytes, blood cells and free microaggregates were repeated (n= 19 each). Compared with baseline, the investigated autotransfusion devices reduced the median load of potassium (baseline: 52 mEq L(-1); HCS: 4 mEq L(-1); CATS(quality): 4 mEq L(-1); CATS(emergency): 17 mEq L(-1); each P < 0.001), restored a physiologic electrolyte balance and significantly decreased the load of leucocytes, glucose and protein. Whereas the quantity of microaggregates was not reduced by HCS, CATS(emergency) decreased the load of cell fragments below 7.8 microm (P < 0.05 vs. baseline). Using CATS(quality) decreased the load of cell fragments not only to a diameter below 7.8 microm (P < 0.001 vs. baseline) but also of microaggregates between 7.8 and 17.6 microm (P < 0.05 vs. baseline). In situations where long-stored PRBC have to be transfused, the procedure described here may be feasible to reduce clinically relevant side effects, i.e. hyperkalaemia and microvascular obstruction secondary to free cell fragments. This approach could be especially useful in patients undergoing massive transfusion and/or suffering from renal failure.

Washing of irradiated red blood cells prevents hyperkalaemia during cardiopulmonary bypass in neonates and infants undergoing surgery for complex congenital heart disease

High concentrations of potassium and lactate in irradiated red cells transfused during cardiopulmonary bypass may have detrimental effects on infants and neonates undergoing cardiac surgery. The effects of receiving washed and unwashed irradiated red cells from the cardiopulmonary circuit on serum potassium and lactate concentrations were compared. The study population included neonates and infants undergoing heart surgery for complex congenital heart disease. A control group (n=11) received unwashed irradiated red cells and the study group (n=11) received irradiated red cells washed in a cell saver (Dideco Electa) using 900ml of 0.9% saline prior to pump priming. Potassium and lactate concentrations were compared before, during and after bypass. Washing irradiated red cells reduced donor blood [potassium] from>20 to 0.8+/-0.1mmol/l, and [lactate] from 13.7+/-0.5 to 5.0+/-0.3mmol/l (p<0.001). The resulting prime had significantly lower [potassium] and [lactate] than the unwashed group (potassium 2.6+/-0.1 vs 8.1+/-0.4mmol/l, p<0.001; lactate 2.6+/-0.2 vs 4.6+/-0.3mmol/l, p<0.001). Peak [potassium] in the unwashed group occurred 3 minutes after going on bypass (4.9+/-0.3mmol/l) and during rewarming (4.9+/-0.4mmol/l). These were significantly higher than the washed group (3.1+/-0.1, p<0.001 and 3.0+/-0.1mmol/l, p<0.001). The [potassium] was greater than 6.0mmol/l for 4 out of these 11 unwashed patients compared with none of the washed group. Immediately post-bypass the washed group had significantly lower serum [potassium] (3.2+/-0.1 vs 4.2+/-0.2mmol/l, p=0.002). There was no significant difference in [lactate] between groups during and after cardiopulmonary bypass. The washing of irradiated red cells reduces potassium and lactate loads and prevents hyperkalaemia during cardiopulmonary bypass. The washing of irradiated red cells should be considered in neonates and infants undergoing cardiac surgery for complex congenital heart disease.

Surface Irrigation of Dairy Farm Effluent, Part II: System Design and Operation

Dairy farms with as many as 200 cows still handle their wastewaters and solid manures separately. Because of the large volume produced and their low nutrient load, these dairy farm effluents (DE) are costly and time consuming to land spread using conventional equipment, such as the tanker. The purpose of this study was to test the equipment and cost to determine the cost of the equipment adapted for the simplified surface irrigation of DE and to establish best management practices to reduce risks of groundwater contamination. The project was conducted on two dairy farms in South Western of Montreal, Canada, where typical DE were applied to irrigated plots of 0·5 and 0·3 ha, respectively, and the groundwater quality was compared to a control plot of the same size. Groundwater quality was monitored for nutrients (total nitrogen, total phosphorus, total potassium and pH) and bacterial counts (total coliforms, faecal coliforms, and faecal streptococci). A manure pump and conventional water irrigation pipes were satisfactory in irrigating with the DE without clogging as long as the DE was collected in a tank separate from that of the solid manure. During all applications, subsurface seepage losses occurred, but these would not be lost to the watercourse when applied in quantities respecting irrigation guidelines and on soils where the groundwater table was at or below the depth of the subsurface drains. Nevertheless, these seepage losses represented less than 1% of the total volume of DE applied, and the seepage nutrient and bacterial load was generally less than half of that of the irrigated DE. The surface irrigation system reduced the cost of land spreading DE from CAN $3·25 m−3 (conventional tanker) to CAN $1·10 m−3 (surface irrigation). The heavy total potassium load of the DE requires the rotation of the irrigation plot, on an annual basis.

Advances in Potassium Catalyzed NOx Reduction by Carbon Materials: An Overview

The research work conducted in our group concerning the study of the potassium-catalyzed NOx reduction by carbon materials is presented. The importance of the different variables affecting the NOx−carbon reactions is discussed, e.g. carbon porosity, coal rank, potassium loading, influence of the binder used, and effect of the gas composition. The catalyst loading is the main feature affecting the selectivity for NOx reduction against O2 combustion. The NOx reduction without important combustion in O2 occurs between 350 and 475 °C in the presence of the catalyst. The presence of H2O in the gas mixture enhances NOx reduction at low carbon conversions, but as the reaction proceeds, it decreases as the selectivity does. The presence of CO2 diminishes the activity and selectivity of the catalyst. SO2 completely inhibits the catalytic activity of potassium due to sulfate formation.

Type 2 Pseudohypoaldosteronism: New Insights Into Renal Potassium, Sodium, and Chloride Handling

Type 2 Pseudohypoaldosteronism: New Insights Into Renal Potassium, Sodium, and Chloride Handling

Causes of Hypocitraturia in Recurrent Calcium Stone Formers: Focusing on Urinary Potassium Excretion

Multiple factors associated with hypocitraturia have been identified. However, limited studies addressing the causal relationship to hypocitraturia are available. We therefore conducted this study to determine factors associated with hypocitraturia and show their causal relationship in recurrent calcium stone formers. Dietary review and 24-hour urine samples were obtained from all recurrent calcium stone formers referred for metabolic workup in the stone clinic. One month of oral potassium chloride supplementation was prescribed to stone formers to determine the causal relationship between urinary potassium and citrate levels. Eighty-three subjects, 44 men and 39 women, were recruited to participate in this study. Hypocitraturia (citrate < 300 mg/d [<1.43 mmol/d]) was found in 50.6% of subjects. Four independent urinary variables associated with hypocitraturia were identified, including potassium level, net gastrointestinal alkaline absorption, calcium level, and titratable acid. Urinary potassium level was the strongest predictor of urinary citrate level. Hypocitraturic subjects also had lower fruit intake compared with subjects with high urinary citrate levels. Potassium chloride supplementation to a subgroup of this population (n = 58) resulted in a significant increase in urinary citrate excretion (350.73 +/- 27.25 versus 304.15 +/- 30.00 mg/d [1.67 +/- 0.13 versus 1.45 +/- 0.14 mmol/d]; P < 0.02), but no alteration in fractional excretion of citrate (19.7% +/- 2.7% versus 23.1% +/- 2.4%; P > 0.05). Hypocitraturia was found to be a common risk factor associated with recurrent calcium stone formation and low urinary potassium level, low alkaline absorption, low urinary calcium level, and high titratable acid excretion. Hypocitraturia is predominantly of dietary origin. Estimation of fruit intake should be included in the metabolic evaluation for recurrent calcium stone formation.

Noble-free potassium-bimetallic catalysts supported on beta-zeolite for the simultaneous removal of NO x and soot from simulated diesel exhaust

This paper deals with the activity of the KCu and KCo catalysts supported on beta-zeolite for the simultaneous NO x /soot removal from a simulated diesel exhaust, containing C 3H 6 as model hydrocarbon. In order to reveal the effect of potassium, the corresponding monometallic catalysts (Co/beta and Cu/beta) were analyzed and different potassium loadings were used. In addition, for comparative purpose, the performance of a platinum based catalyst (Pt/beta) was studied. All noble-free catalysts show, at 450 °C, a high activity for the simultaneous NO x /soot removal. Among them, K1Cu/beta presents the best global performance at 350 and 450 °C achieving a high soot consumption rate (comparable to platinum catalysts) and the highest NO x reduction. In contrast to platinum catalysts, K1Cu/beta has the advantage that the main reaction products are N 2 and CO 2.

Seasonal Bacteriological Analysis of Gola River Water Contaminated with Pulp Paper Mill Waste in Uttaranchal, India

The seasonal physico-chemical and microbial quality of Gola river water has been analyzed after confluence of pulp paper mill waste. The study revealed that it has enhanced 20-30 times pollution load of BOD, COD, TDS, TSS, sulphate, chloride, sodium, nitrate, potassium, lignin and phenol after mixing of pulp paper mill waste with river water in all season. Further, it induced the bacterial growth by increasing most probable number value of E. coli was 1.57 x 10(4), 1.6 x 10(4), 1.37 x 10(4) and SPC count was 1.68 x 10(4), 1.64 x 10(4), 1.67 x 10(4)/100 ml during summer, monsoon, winter respectively. While the most probable number value in river water before mixing of pulp paper mill waste was 1.4 x 10(2), 1.82 x 10(2), 1.5 x 10(2) and SPC count was 2.8 x 10(3), 2.89 x 10(3), 2.78 x 10(3)/100 ml during summer, monsoon and winter respectively. This indicated from 88-114 fold increase in most probable number value of E. coli and 56.55-60.0 times increase in SPC count of river water after mixing of effluent in summer, monsoon and winter. Moreover, the most probable number value in effluent itself before mixing was 3.4 x 10(2), 3.3 x 10(2), 2.8 x 10(2) and SPC count was 6 x 10(4), 6.5 x 10(4), 6 x 10(4)/100 ml during summer, monsoon, winter, respectively. Furthermore, it was revealed that the seasonal variation also regulated the bacterial population dynamics as per the physico-chemical quality, in which E. coli was found highest at the rate of (5.9 x 10(4)), E. aerogenes (5.3 x 10(4)), P. aeruginosa (1.3 x 10(4)), S. aureus (3.2 x 10(3)), K. pneumoniae (2.6 x 10(4)), Enteritidis (1.1 x 10(4)) on monsoon season and V. cholerae (7.4 x 10(2)), V. vulnificus (9.2 x 10(2))/100 ml in river water when contaminated with pulp paper mill waste in monsoon season. Thus, the monsoon season showed presence of FC and TC indicated the thermo-tolerant and disease causing group of bacterial population in effluent and its sequence was observed as monsoon>summer>winter. This indicated the growth of many pathogenic and non-pathogenic bacteria for health hazards with contamination of pulp paper waste in aquatic ecosystem within the vicinity of pulp paper mill industry.

WNK1 kinase isoform switch regulates renal potassium excretion

Members of the WNK family of serine/threonine kinases have been implicated as important modulators of salt homeostasis, regulating the balance between renal sodium reabsorption and potassium excretion. Gain-of-expression mutations in the WNK1 gene uncouple Na(+) and K(+) balance and cause a familial disorder of diminished renal potassium excretion, excessive sodium retention, and hypertension (pseudohypoaldosteronism type II or Gordon's syndrome). Alternative splicing of the WNK1 gene produces a kidney-specific short form of WNK1 (KS-WNK1) and a more ubiquitous long form (L-WNK1), but it is not clear how either of these isoforms influence renal potassium excretion. Here we demonstrate that KS-WNK1 and L-WNK1 converge in a pathway to regulate the renal outer-medullary K(+) channel, Kir1.1. Reconstitution studies in Xenopus oocytes reveal that L-WNK1 significantly inhibits Kir1.1 by reducing cell surface localization of the channel. A catalytically inactive L-WNK1 mutant has no inhibitory effect on Kir1.1, indicating that channel inhibition depends on kinase activity. KS-WNK1, lacking an intact kinase domain, does not directly alter Kir1.1. Instead, KS-WNK1 negatively regulates L-WNK1 to release Kir1.1 from inhibition. Acute dietary potassium loading increases the relative abundance of KS-WNK1 to L-WNK1 transcript and protein in the kidney, indicating that physiologic up-regulation of Kir1.1 activity involves a WNK1 isoform switch and KS-WNK1-mediated release from L-WNK1 inhibition. Thus, these observations provide evidence for the physiological regulation of Na(+) and K(+) balance by a kinase isoform switch mechanism.

Aldosterone Antagonism in Chronic Kidney Disease

Angiotensin-converting enzyme (ACE) inhibitors are potent members of the arsenal to treat chronic kidney disease (CKD). By reducing blood pressure (BP) and disproportionately decreasing intraglomerular pressure, this class of drugs also reduces proteinuria and slows progression of CKD (1,2). Given the high prevalence of cardiovascular disease in this population, it is noteworthy that ACE inhibitors also decrease the incidence of stroke, myocardial infarction (MI), and cardiovascular mortality in patients who are at high cardiovascular risk (3). More recently, data reporting similar benefits of angiotensin receptor blockers (ARB) support their use in the treatment of CKD as well, especially in individuals with type 2 diabetes (4). Furthermore, one sizable study suggested that the combination of an ACE inhibitor and ARB may be more effective than either agent alone (5). Parving and colleagues (6) called attention to the effects of high-dose ARB therapy, up to three times the recommended dose, as an additional means of effectively interrupting the renin-angiotensin-aldosterone system (RAAS). By logical extension, further blockade of the RAAS by direct antagonism of aldosterone also may prove beneficial. Indeed, aldosterone seems to be a potent effector of renal injury (7–9). In the rare cases of primary aldosteronism and its functional analogue, the even more rare Liddle’s syndrome, the observed renal injury probably is independent of the more proximal elements of the RAAS (10,11). Animal models provide an expeditious tool for assessing pathophysiologic change and the efficacy of intervention. The classic model of primary aldosteronism, the mineralocorticoid–nephrectomy–high-salt model of hypertension, develops systemic and glomerular capillary hypertension and sustains renal damage (12). In the remnant kidney model of CKD, ACE inhibitors and ARB attenuate renal injury (13). However, this protection, which is associated with suppression of aldosterone secretion, is abrogated by exogenous aldosterone infusion with return of …

Pseudohyperkalemia in serum: the phenomenon and its clinical magnitude

We investigated in detail the difference between serum and plasma potassium levels in patients with several conditions associated with pseudohyperkalemia. In total, 435 patients with either thrombocytoses, erythrocytoses, leucocytoses, or a mixed-type disorder and 30 healthy controls were included. In each case, the index Dk [serum potassium minus plasma potassium] and the index Dk100 (Dk x 100,000/platelets), which indicates the Dk value that corresponds to platelets of 100,000/mm(3), were estimated. Median Dk was significantly higher in the groups with platelet, erythrocyte, or mixed-type disorders than in the controls (P=0.001). Among these groups, Dk values were significantly higher in patients with thrombocytosis or mixed-type disorders compared with those with erythrocytosis (P<0.001, for both). Furthermore, no significant difference was observed in Dk values between controls and patients with white blood cell disorders (P=0.74). Dk values did not exceed 2.61 mmol/L, whereas Dk100 values were inversely related to platelet counts (r=-0.351, P<0.01). In conclusion, pseudohyperkalemia is mainly present in patients with thrombocytosis or mixed-type disorders, probably as a result of the degranulation of platelets, which offers a potassium load to the surrounding plasma at the time of clot formation in vitro. However, the degree of pseudohyperkalemia does not increase proportionally with the increase of platelet counts, which may be associated with transfer of part of potassium load from the plasma back into red and white blood cells.

μSR study on ferrimagnetic properties of potassium clusters incorporated into low silica X zeolite

Potassium clusters are stabilized in the cages of low silica X zeolite, where the cages with the inside diameter of ∼13 A are arrayed in a diamond structure. The average number of potassium atoms per cage, n, is changed from ∼6.3 to the saturated value of ∼8.8 by controlling the guest potassium loading density. The temperature dependence of magnetization shows the typical behavior of the N-type ferrimagnetism at n∼6.8 and n∼8.3. The zero field μSR spectra show significant increase in the relaxation rate below the Curie temperature, 5 K, in the sample with n∼6.8. The time dependence of asymmetry shows almost full amplitude of decrease, indicating that the internal field below the magnetic phase transition arises in the almost full volume of the sample. The longitudinal field μSR spectra at 1.7 K show the typical decoupling behavior of a static internal field. A model of ferrimagnetism is proposed based on the structure of the zeolite, where a magnetic sublattice of itinerant electron ferromagnetism is assumed.

Paralysis Periodica Paramyotonica Caused by SCN4A Arg1448Cys Mutation

Paralysis periodica paramyotonica is an overlapping disease that shares the features of paramyotonia characteristic of paramyotonia congenita (PC) and periodic paralysis characteristic of hyperkalemic periodic paralysis. We report the case of a 23-year-old man with paralysis periodica paramyotonica. His father and a younger brother also exhibited a similar phenotype. A SCN4A Arg1448Cys mutation was detected in this family. The affected family members exhibited marked shifts in compound muscle action potential amplitudes on exercise test, and muscle weakness could be induced by potassium loading and cold exposure. This case demonstrates that SCN4A Arg1448Cys can produce paralysis periodica paramyotonica. Other genetic or environmental factors may modulate the manifestation of SCN4A Arg1448Cys mutation.