[Quality of life of Crohn's disease patients]. / Kvalita zivota u Crohnovy nemoci.

BACKGROUND: The assessment of the quality of life in chronic diseases has started to move from clinical studies to practice. The main goal of the project was to assess the quality of life of Crohn's disease patients from two Czech centres by means of Czech versions of the general World Health Organization Quality of Life--BREF and specific Inflammatory Bowel Disease Questionnaire, to compare the quality of life of patients with an active disease and those in remission and to compare the quality of life with the general Czech population. METHODS AND RESULTS: 103 patients with Crohn's disease underwent a survey performed by means of two Czech versions of quality of life questionnaire. The dataset consisted of 53 men and 50 women; the average age of patients was 42 years. Increased activity was observed in 45 patients; 58 patients were in remission. By means of WHOQOL-BREF, we found the average global score of quality of life and satisfaction with health in our group to be 3.5 (Czech standard 3.8) and 2.8 (Czech standard 3.7), respectively. The results were compared to the Czech standards. A negative influence of disease activity was statistically significant (p < 0.001) in all domains using either of the two questionnaires. Clinical factors such as the use of corticosteroids or immunosuppressives, and the history of surgery influenced some domains. CONCLUSIONS: The results from our study indicate that the disease activity may have a significant impact on the quality of life in Crohn's disease patients. A combination of the general and specific questionnaire may identify factors that would otherwise remain unappreciated properly. The quality of life of patients in remission was comparable to that of the general Czech population.

Intracellular sodium modulates mitochondrial calcium signaling in vascular endothelial cells.

We have investigated the role of extramitochondrial Na(+) for the regulation of mitochondrial Ca(2+) concentration ([Ca(2+)](m)) in permeabilized single vascular endothelial cells. [Ca(2+)](m) was measured by loading the cells with the membrane-permeant Ca(2+) indicator fluo-3/AM and subsequent removal of cytoplasmic fluo-3 by surface membrane permeabilization with digitonin. An elevation of extramitochondrial Ca(2+) resulted in a dose-dependent increase in the rate of Ca(2+) accumulation into mitochondria (k(0.5) = 3 microm) via the mitochondrial Ca(2+) uniporter. In the presence of 10 mm extramitochondrial Na(+) ([Na(+)](em)), repetitive application of brief pulses of high Ca(2+) (2-10 microm) to simulate cytoplasmic [Ca(2+)] oscillations caused transient increases of [Ca(2+)](m) characterized by a fast rising phase that was followed by a slow decay. Removal of extramitochondrial Na(+) or inhibition of mitochondrial Na(+)/Ca(2+) exchange with clonazepam blocked mitochondrial Ca(2+) efflux and resulted in a net accumulation of Ca(2+) by the mitochondria. Half-maximal activation of mitochondrial Na(+)/Ca(2+) exchange occurred at [Na(+)](em) = 4.4 mm, which is well within the physiological range of cytoplasmic [Na(+)]. This study provides evidence that Ca(2+) efflux from the mitochondria in vascular endothelial cells occurs solely via Na(+)/Ca(2+) exchange and emphasizes the important role of intracellular Na(+) for mitochondrial Ca(2+) regulation.

Capacitative Ca2+ entry is graded with degree of intracellular Ca2+ store depletion in bovine vascular endothelial cells.

1. In endothelial cells, release of Ca2+ from endoplasmic reticulum (ER) Ca2+ stores activates Ca2+ influx via the capacitative Ca2+ entry (CCE) pathway. In cultured bovine pulmonary artery endothelial cells, we investigated the relationship between intracellular Ca2+ store load and CCE activity, as well as the kinetics of CCE activation and deactivation, by simultaneously measuring changes in [Ca2+]i and unidirectional manganese (Mn2+) entry through the CCE pathway. 2. Submaximal concentrations of ATP caused quantal release of Ca2+ from the ER, resulting in a dose-dependent depletion of Ca2+ stores and acceleration of Mn2+ entry. Mn2+ entry rate, as a measure of CCE activity, was graded with the amount of released Ca2+. Maximal activation of CCE did not require complete store depletion. 3. Slow depletion of the ER by exposure to the ER Ca2+ pump inhibitor cyclopiazonic acid resulted in a delayed activation of CCE, revealing a temporal dissociation between release of Ca2+ from intracellular stores and activation of CCE. 4. During [Ca2+]i oscillations, at frequencies higher than 0.5 spikes min-1, each Ca2+ spike resulted in a progressive acceleration of CCE without leading to oscillations of Ca2+ entry. In contrast, low frequency [Ca2+]i oscillations were paralleled by transient CCE that was activated and deactivated with each Ca2+ spike, resulting in an oscillatory pattern of Ca2+ entry. 5. It is concluded that CCE is a rapidly activating process which is graded with store depletion and becomes fully activated before complete depletion. The duration of CCE activation correlates with the degree of store depletion and the time that is required to refill depleted stores. Overall, a mechanism of graded CCE prevents exhaustion of intracellular Ca2+ reserves and provides an efficient way to respond to variable degrees of intracellular store depletion.

Dynamic regulation of [Ca2+]i by plasma membrane Ca(2+)-ATPase and Na+/Ca2+ exchange during capacitative Ca2+ entry in bovine vascular endothelial cells.

The dynamic regulation of Ca2+ extrusion by the plasma membrane Ca(2+)-ATPase (PMCA) and Na+/Ca2+ exchange (NCX) was investigated in single cultured calf pulmonary artery endothelial (CPAE) cells using indo-1 microfluorimetry to measure cytoplasmic Ca2+ concentration ([Ca2+]i). The quantitative analysis of the recovery from an increase of [Ca2+]i elicited by activation of capacitative Ca2+ entry (CCE) served to characterize kinetic parameters of these Ca2+ extrusion systems in the intact cell. In CPAE cells the PMCA is activated in a Ca(2+)- and time-dependent manner. Full activation of the pump occurs only after [Ca2+]i has been elevated for at least 1 min which results in an increase of the affinity of the pump for Ca2+ and an increase in the apparent maximal extrusion rate (Vmax). Application of calmodulin antagonists W-7 and calmidazolium chloride (compound R 24571) revealed that calmodulin is a major regulator of PMCA activity in vivo. Sequential and simultaneous inhibition of PMCA and NCX suggested that both contribute to Ca2+ extrusion in a non-additive fashion. The activity of one system is dynamically adjusted to compensate for changes in the extrusion rate by the alternative transporter. It was concluded that in vascular endothelial cells, the PMCA functions as a calmodulin-regulated, high-affinity Ca2+ removal system. The contribution by the low-affinity NCX to Ca2+ clearance became apparent at [Ca2+]i > approximately 150 nM under conditions of submaximal activation of the PMCA.

Time-dependent modulation of capacitative Ca2+ entry signals by plasma membrane Ca2+ pump in endothelium.

In vascular endothelial cells, depletion of intracellular Ca2+ stores elicited capacitative Ca2+ entry (CCE) that resulted in biphasic changes of intracellular Ca2+ concentration ([Ca2+]i) with a rapid initial peak of [Ca2+]i followed by a gradual decrease to a sustained plateau level. We investigated the rates of Ca2+ entry, removal, and sequestration during activation of CCE and their respective contributions to the biphasic changes of [Ca2+]i. Ca2+ buffering by mitochondria, removal by Na+/Ca2+ exchange, and a fixed electrical driving force for Ca2+ (voltage-clamp experiments) had little effect on the CCE signal. The rates of entry of Mn2+ and Ba2+, used as unidirectional substitutes for Ca2+ entry through the CCE pathway, were constant and did not follow the concomitant changes of [Ca2+]i. Pharmacological inhibition of the plasma membrane Ca2+ pump, however, abolished the secondary decay phase of the CCE transient. The disparity between the biphasic changes of [Ca2+]i and the constant rate of Ca2+ entry during CCE was the result of a delayed, Ca(2+)-dependent activation of the pump. These results suggest an important modulatory role of the plasma membrane Ca2+ pump in the net cellular gain of Ca2+ during CCE.

Effect of "core" 2'5'-oligoadenylates on the phosphorylation-dependent calcium channels in GH3 cells.

The effect of intracellular application of isolated and purified forms of "core" oligoadenylates (2',5',ApApA, 2',5'ApApepoxyA and 3',5'ApApA) on the phosphorylation-dependent calcium channels in GH3 cells was investigated. The role of Mg2+ ions in realizing of the processes of enhancement of phosphorylation-dependent calcium currents and prolongation of their wash-out during whole-cell patch-clamp experiments was examined.

Glucocorticoid modulation of calcium currents in growth hormone 3 cells.

Clonal malignant pituitary growth hormone 3 cells were used for the analysis of the influence of hydrocortisone and dexamethasone on voltage-gated calcium currents and hormone secretion. The whole-cell patch-clamp technique was used. The presence of low-threshold inactivating and high-threshold persisting components in the total calcium current was shown; they could be separated at less negative holding potential level. Some increase in current densities of both components was observed as early as 30 min after treatment with 10(-6) mol/l glucocorticoids. The increase was maximal for both types of currents after 2 h of incubation; however, the high-threshold component was affected much more strongly (current density increased by more than four-fold) than the low-threshold one (current density increased by about a three-fold). Potentiation of currents was blocked by actinomycine D (10(-4) M), suggesting that protein synthesis was required. A substantial increase in growth hormone secretion (measured by radioimmunoassay method) was observed in the same cells after 2 h of incubation with hydrocortisone, while the secretion of prolactin remained even slightly depressed.