5,872 research outputs found
The use of PC at work and job satisfaction
No full textThere is a strong association between the use of PC at work (and PC literacy) and the overall job satisfaction and intended early retirement, particularly for white collar workers
The analysis shows that individuals with high PC skills and having a job that requires the use of a computer are more satisfied with their jobs and less keen to retire early
Over-skilled women (who have PC skills but do not need them for their jobs) are more satisfied with their jobs and less likely to desire to retire as soon as possibl
Mineralocorticoid effector mechanism of liquorice derivatives in human mononuclear leukocytes.
No full textThe mineralocorticoid effector mechanism of glycyrrhetinic acid and of its ester derivative carbenoxolone was evaluated in human mononuclear leukocytes by radioreceptorassay and measurement of intracellular sodium and potassium after incubation of the cells with or without the drugs. The affinity of both compounds for mineralocorticoid receptors in this human model was also compared with that found in kidney cytosol from adrenalectomized rats. Glycyrrhetinic acid possesses a measurable affinity for mineralocorticoid receptors in mononuclear leukocytes, which is 1:3,000 that of aldosterone itself. Carbenoxolone does not bind to the receptors in mononuclear leukocytes, in contrast with kidney cytosol where the drugs show a parallel affinity. The mean intracellular content of sodium in mononuclear leukocytes from 7 volunteers was 35% higher (p less than 0.05) after incubation with 3 mumol glycyrrhetinic acid than after incubation with an equivalent amount of carbenoxolone, or in medium alone. The effect of glycyrrhetinic acid was completely reversed by addition of canrenone for the period of incubation. We conclude that the syndrome of pseudohyperaldosteronism from carbenoxolone is thus probably not related to a direct agonist effect of the drug at the level of mineralocorticoid receptors, but that any action must follow in vivo conversion into glycyrrhetinic acid by hydrolysis
A PC parallel port button box provides millisecond response time accuracy under Linux
No full textFor psychologists, it is sometimes necessary to measure people's reaction times to the nearest millisecond. This article describes how to use the PC parallel port to receive signals from a button box to achieve millisecond response time accuracy. The workings of the parallel port, the corresponding port addresses, and a simple Linux program for controlling the port are described. A test of the speed and reliability of button box signal detection is reported. If the reader is moderately familiar with Linux, this article should provide sufficient instruction for him or her to build and test his or her own parallel port button box. This article also describes how the parallel port could be used to control an external apparatus
Effect of aldosterone on sodium and potassium concentrations in human mononuclear leukocytes
No full textThe in vitro effect of aldosterone on intracellular sodium and potassium concentration was investigated in human mononuclear leukocytes (HML). HML were separated from blood by a Percoll gradient and intracellular Na+ and K+ were determined before and after incubation for 1 h at 37 degrees C. The intracellular (ic) Na+ and K+ concentrations after separation of HML were 17 +/- 5 and 59 +/- 18 mmol/kg wet cells (mean +/- SD, n = 6), respectively. In the absence of aldosterone the ic Na+ concentration decreased to 12 +/- 4, whereas the ic Na+ concentration remained constant at 18 +/- 8 mmol/kg wet cells when aldosterone (1.4 nM) was added to the incubation medium. In parallel, the ic K+ concentration decreased without added aldosterone but remained constant with aldosterone. The effect of aldosterone on the ic Na+ and K+ concentrations of HML was blocked by the aldosterone antagonist canrenone (140 nM). Cortisol at a physiological concentration (40 nM) did not alter ic Na and K concentrations in these cells. The results suggest that aldosterone binding to specific receptors in human mononuclear leukocytes significantly contributes to the regulation of monovalent cation levels in these cells. Thus, this easily accessible model of HML allows study of the effects of mineralocorticoids in relation to their receptors in intact cells in normal and pathological states
Lack of effect of aldosterone on intracellular sodium and potassium in mononuclear leucocytes from patients with pseudohypoaldosteronism.
No full textIn three patients with pseudohypoaldosteronism the effects of aldosterone on intracellular sodium and potassium were studied and compared with normal controls in whom aldosterone prevents the loss of sodium and potassium in vitro. Mononuclear leukocytes were incubated with or without aldosterone (1.4 nM) in RPMI-1640 for 1 h at 37 degrees C. After two washes in isotonic MgCl2 the wet cell pellets were weighted and intracellular sodium and potassium determined by flame photometry, results are expressed as mmol/kg wet cells. In the patients intracellular sodium fell from 18, 23 and 29 mmol/kg to 14, 18 and 11 mmol/kg, respectively, in the absence of aldosterone. With aldosterone added to the incubation medium sodium was not different from values obtained without aldosterone (15, 20 and 13 mmol/kg). Corresponding values for potassium were 89, 48 and 75 mmol/kg before and 68, 32 and 51 mmol/kg after incubation without and 69, 36 and 54 mmol/kg after incubation with aldosterone. Thus, incubation with aldosterone did not show an effect on intracellular sodium and potassium as seen in normals. Baseline values of sodium and potassium before the incubation were within the normal range. From these results it is concluded that in patients with pseudohypoaldosteronism the absent or decreased number of mineralocorticoid receptors in mononuclear leucocytes are accompanied by a lack of response of intracellular sodium and potassium to aldosterone in vitro. However, normal baseline intracellular electrolyte concentrations in these patients may indicate that mineralocorticoids are not involved in the maintenance of normal levels of intracellular sodium and potassium
Parallel determination of mineralocorticoid and glucocorticoid receptors in T- and B-lymphocytes of human spleen
No full textThe binding characteristics of glucocorticoid and mineralocorticoid receptors were determined in T- and B-lymphocytes from the spleen of four deceased kidney donors. The number of glucocorticoid and mineralocorticoid receptors was equivalent in T- and B-cells (respectively, 1308 +/- 364 and 1335 +/- 520 glucocorticoid receptors per cell, and 174 +/- 29 and 164 +/- 24 mineralocorticoid receptors per cell). The number of binding sites per cell was 5- to 10-fold higher for dexamethasone than for aldosterone. The apparent dissociation constant of dexamethasone for glucocorticoid receptors was 2-fold higher than that of aldosterone for mineralocorticoid receptors. In conclusion, subpopulations of human lymphocytes have an equal number of glucocorticoid and mineralocorticoid receptors
Aldosterone Influences the Potassium and Sodium Concentration In Human Mononuclear Leukocytes
No full textEffect of aldosterone on potassium and sodium concentrations in mononuclear leukocytes from normal subjects and from a patient with pseudohypoaldosteronism
No full textAldosterone receptors in different types of primary hyperaldosteronism
No full textThe number of mineralocorticoid-binding sites on mononuclear leukocytes and plasma aldosterone (aldo) concentrations were measured in patients with different types of primary hyperaldosteronism. Patients with unilateral adenoma and patients with bilateral adrenal hyperplasia had a significantly lower (P less than 0.001) mean number of binding sites for aldo [144 +/- 36 (+/- SD; n = 6) and 140 +/- 28 sites/cell (n = 4), respectively] compared with normal subjects (292 +/- 110 sites/cell; n = 25). In four patients with dexamethasone-suppressible hyperaldosteronism, mineralocorticoid-binding sites in mononuclear leukocytes were normal (291 +/- 108 sites/cell). In all patients undergoing surgery for unilateral adenoma, the receptors normalized 3 months after the operation. In two patients the reduction in receptors persisted for a short time after surgery even though the plasma aldo level had already normalized. We conclude that mineralocorticoid excess produces down-regulation of mineralocorticoid receptors, which, in turn, might contribute to the genesis of the aldo escape phenomenon
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