A Banach space $X$ has Pełczyński's property (V) if for every Banach space $Y$ every unconditionally converging operator $T\colon X\to Y$ is weakly compact. H. Pfitzner proved that $C^*$-algebras have Pełczyński's property (V). In the preprint (Krulišová, (2015)) the author explores possible quantifications of the property (V) and shows that $C(K)$ spaces for a compact Hausdorff space $K$ enjoy a quantitative version of the property (V). In this paper we generalize this result by quantifying Pfitzner's theorem. Moreover, we prove that in dual Banach spaces a quantitative version of the property (V) implies a quantitative version of the Grothendieck property., Hana Krulišová., and Obsahuje bibliografii
We determined and characterized the Mg2+-dependent, Ca2+-stimulated ATPase (Ca-ATPase) activity in cell plasma membranes from the myometrium of pregnant women, and compared these characteristics to those of the active Ca2+-transport already demonstrated in this tissue. Similarly to the Ca2+-transport system, the Ca2+-ATPase is Mg2+-dependent, stimulated by calmodulin, and inhibited by vanadate. The Km for Ca2+ activation is 0.40 m M, very similar to that found for active calcium transport, i.e. 0.25 m M. Consequently, this Ca2+-ATPase can be responsible for the active calcium transport across the plasma membranes of smooth muscle cells., F. Carrera, T. Proverbio, R. Marín, F. Proverbio., and Obsahuje bibliografii
Intracellular free Ca2+ is one of important biological signals regulating a number of cell functions. It has been discussed widely and extensively in several cell types during the past two decades. Attention has been paid to the Ca2+ transportation in mesenchymal stem cells in recent years as mesenchymal stem cells have gained considerable interest due to their potential for cell replacement therapy and tissue engineering. In this paper, roles of intracellular Ca2+ oscillations and its transporters in mesenchymal stem cells have been reviewed., B. Ye., and Obsahuje bibliografii a bibliografické odkazy
The present study was devised to assess the effects of cadmium chloride (CdCl2) administration on certain andrological, endocrinological and biochemical alterations in adult male rabbits (n=24). The animals were assigned to control (n=8) and experimental (n=16) group. Experimental group was orally administered with 1.5 mg/kg body weight of CdCl2. The trials were carried out for a total of 5 weeks and blood sampling was carried out on weekly basis. A gradual decrease was noticed for body weight in the experimental group from week 1 to 5, being significantly lower in week 4 and 5 (P<0.05). A similar decremented trend was noticed for serum testosterone level being significantly lower in experimental group in week 4 and 5 (P<0.001). Significantly lower values were noticed for prolactin in experimental group in week 4 and 5 (P<0.05), than in the control. On the contrary, serum cortisol level showed a gradual increase in experimental group, from week 1 to 5, being significantly higher in week 4 and 5 (P<0.05). Regarding the biochemical attributes, all the parameters under study revealed a gradually ascending trend. Statistical significance was, however, achieved in varying weeks and at varying levels. The total protein and albumin were significantly higher in week 4 and 5 (P<0.01); alanine aminotransferase in week 2 (P<0.01), 3 (P<0.001), 4 (P<0.01) and 5 (P<0.001); aspartate aminotransferase in week 1, 2, 3, 4 and 5 (P<0.01); and alkaline phosphatase in week 1, 2 (P<0.01), 3, 4 and 5 (P<0.0001), respectively. Overall mortality rate in experimental group was 68.75 (11/16). In a nutshell, Cd exposure results in adverse effects on all physiological parameters of body and may lead to lethal consequences., S. Sajjad, H. Malik, U. Farooq, F. Rashid, H. Nasim, S. Tariq, S. Rehman., and Obsahuje bibliografii
We studied cadmium toxicity in murine hepatocytes in vitro. Cadmium effects on intracellular free Ca2+ concentration ([Ca2+]i) were assayed, using a laser scanning confocal microscope with a fluorescent probe, Fluo-3/AM. The results showed that administration of cadmium chloride (CdCl2, 5, 10, 25 μM) resulted in a dose-dependent decrease of hepatocyte viability and an elevated aspartate aminotransfe rase (AST) activity in the culture medium (p<0.05 for 25 μM CdCl2 vs. control). Significant increases of lactate dehydrogenase (LDH) activities in 10 and 25 μM CdCl2-exposed groups were observed (p<0.05 and p<0.01, respectively). A greatly decreased albumin content and a more malondialdehyde (MDA) formation also occurred after CdCl2 treatment. The Ca2+ concentrations in the culture medium of CdCl2-exposed hepatocytes were significantly decreased, while [Ca2+]i appeared to be significantly elevated (p<0.05 or p<0.01 vs. control). We found that in Ca2+-containing hydroxyethyl piperazine ethanesulfonic acid-buffered salt solution (HBSS) only, CdCl2 elicited [Ca2+]i increases, which comprised an initially slow ascent and a strong elevated phase. However, in Ca2+-containing HBSS with addition of 2-aminoethoxydiphenyl borane (2-APB), CdCl2 caused a mild [Ca 2+] i elevation in the absence of an initial rise phase. Removal of extracellular Ca2+ showed that CdCl2 induced an initially slow [Ca2+]i rise alone without being followed by a markedly elevated phase, but in a Ca2+-free HBSS with addition of 2-APB, CdCl2 failed to elicit the [Ca2+]i elevation. These results suggest that abnormal Ca2+ homeostasis due to cadmium may be an important mechanism of the development of the toxic effect in murine hepatocytes. [Ca2+]i elevation in acutely cadmium-exposed hepatocytes is closely related to the extracellular Ca2+ entry and an excessive release of Ca2+ from intracellular stores., S. S. Wang, L. Chen, S. K. Xia., and Obsahuje bibliografii a bibliografické odkazy
Cíl: Cílem práce bylo shromáždit dostupná klinická, radiologická a patologická data o kalcifikujícím pseudotumoru nervové osy (CAPNON). Soubor: Soubor je tvořen kazuistikou a současně přehledem všech pacientů publikovaných v anglické literatuře, vyhledaných v databázi PubMed pomocí klíčových slov: calcifying pseudoneoplasm, calcifying pseudotumour, brain stone, cerebral calculi a fibro‑osseous lesion. Zahrnuty jsou taktéž všechny citace případů v nalezených publikacích. Výsledky: Včetně naší pacientky jsme v literatuře nalezli celkem 72 pacientů. Intrakraniálně bylo lokalizováno 62 % těchto lézí, v páteřním kanále 31 % a v kranio‑cervikálním přechodu zbylých 7 %. Průměrný věk výskytu je 45,6 (rozmezí 2–83) let. U intrakraniální lokalizace byla tato léze nalezena supratentoriálně v 74 % a infratentoriálně v 26 %. Z nejčastějším projevů intrakraniálních CAPNON jsme nalezli epilepsii v 33,3 %, bolesti hlavy v 24 %, nebo některý z příznaků zadní jámy v 16,7 %. U pacientů s epilepsii byl CAPNON nalezen v temporálním laloku v 50 %. U CAPNON nalezených v páteřním kanále byla dominantním projevem bolest v 82 %, následovaná poruchou chůze v 27 %. V kranio‑cervikálním přechodu byla dominantním příznakem bolest v 80 %. Závěr: CAPNON je velmi vzácnou, benigní, pomalu rostoucí lézí centrální nervové soustavy. Ve většině případů ji nalezneme intrakraniálně s lehkou převahou u mužského pohlaví. Původ této léze není zcela jasný. Diagnóza CAPNON by měla být zvažována setkáme‑li se s nálezem solidně kalcifikované léze při vyšetření CT mozku a hypodenzní léze v T1 a T2 obraze při vyšetření MR. Léčebnou modalitou je radikální odstranění této léze. Incidentální léze musí být monitorovány, jelikož mohou růst a stát se symptomatickými. Klíčová slova: kalcifikující pseudotumor – mozkový kámen – fibro-oseozní léze Autoři deklarují, že v souvislosti s předmětem studie nemají žádné komerční zájmy. Redakční rada potvrzuje, že rukopis práce splnil ICMJE kritéria pro publikace zasílané do biomedicínských časopisů., Aim: The aim of this study was to summarize clinical, radiological and pathological data on calcifying pseudoneoplasm of the neural axis (CAPNON). Methods: A case report of a female patient with CAPNON is presented. In addition, all CAPNON patient case histories published in English language are included. Articles were identified via PubMed searches using the following key words: calcifying pseudoneoplasm, calcifying pseudotumour, brain stone, cerebral calculi and fibro‑osseous lesion. All cases referenced within the identified publications are also included in this review. Results: Seventy two cases were identified, including our case report. Of these, 62% were intracranial, 31% spinal and 7% were located in the cranio‑cervical junction (CCJ). The mean age of the CAPNON patients was 45.6 (range 2–83) years. 74% of intracranial CAPNON were supratentorial and 26% were infratentorial. Symptoms of intracranial CAPNON included epilepsy in 33.3%, headaches in 24% and posterior fossa symptoms in 16.7%. The majority of patients with epileptic seizures had lesions in the temporal lobe (50%). Pain was the dominant symptom in 82% and gait disorder in 27% of spinal CAPNON cases. Pain was the dominant symptom (80%) in CCJ CAPNON. Conclusion: CAPNON is a rare, benign, slowly‑growing lesion of the central nervous system. In the majority of cases, location is intracranial and there is a slightly higher prevalence in men. The origin of CAPNON remains unclear. CAPNON should be considered whenever a CT scan reveals a calcified lesion combined with hypointensity on T1 and T2-weighted MRI. Radical removal is the treatment of choice. Incidental lesions must be monitored, as they may grow and become symptomatic., and T. Krejčí, P. Buzrla, Z. Večeřa, L. Křen, S. Potičný, O. Krejčí, T. Paleček, R. Lipina
Exocytotic machinery in neuronal and endocrine tissues is sensitive to changes in intracellular Ca2+ concentration. Endocrine cell models, that are most frequently used to study the mechanisms of regulated exocytosis, are pancreatic beta cells, adrenal chromaffin cells and pituitary cells. To reliably study the Ca2+ sensitivity in endocrine cells, accurate and fast determination of Ca2+ dependence in each tested cell is required. With slow photo-release it is possible to induce ramp-like increase in intracellular Ca2+ concentration ([Ca2+]i) that leads to a robust exocytotic activity. Slow increases in the [Ca2+] i revealed exocytotic phases with different Ca2+ sensitivities that have been largely masked in step-like flash photo-release experiments. Strikingly, in the cells of the three described model endocrine tissues (beta, chromaffin and melanotroph cells), distinct Ca2+ sensitivity ‘classes’ of secretory vesicles have been observed: a highly Ca2+ -sensitive, a medium Ca2+ -sensitive and a low Ca2+ - sensitive kinetic phase of secretory vesicle exocytosis. We discuss that a physiological modulation of a cellular activity, e.g. by activating cAMP/PKA transduction pathway, can switch the secretory vesicles between Ca2+ sensitivity classes. This significantly alters late steps in the secretory release of hormones even without utilization of an additional Ca2+ sensor protein., J. Dolenšek, M. Skelin, M. S. Rupnik., and Obsahuje bibliografii a bibliografické odkazy
Experimental and epidemiological studies suggest that calcium intake is inversely related to weight gain. Calcium of dairy origin has been shown to be more effective in promoting weight loss. However, clinical studies yielded controversial results concerning the role of calcium intake in weight change. The aim of this study was to ascertain whether the addition of calcium can affect the outcome of 3-week weight management (WM) with a hypocaloric diet characterized by a decreased calcium intake. Overweight/obese women (n=67; BMI 32.2±4.1 kg/m2; age 49.1±12.1 years) underwent a 4-week comprehensive WM program. WM included a 7 MJ/day diet resulting in a stable weight during the first week and a 4.5 MJ/day diet with mean daily calcium intake 350 mg during the second to fourth week. Participants were divided into three age- and BMI-matched groups who received placebo or calcium (500 mg/day). Calcium was administered either as carbonate or calcium of dairy origin (Lactoval). There was no significant difference in weight loss in response to WM between the placebo-treated and calcium-treated groups. However, addition of calcium to the diet resulted in a lower hunger score in the Eating Inventory as well as a decrease in plasma resistin levels. Body composition measured by bioimpedance demonstrated that added calcium leads to preservation of fat-free mass. Nevertheless, a greater loss of fat-free mass in the placebo group might be partly due to a greater loss of water., K. Kabrnová-Hlavatá, V. Hainer, M. Gojová, P. Hlavatý, V. Kopský, J. Nedvídková, M. Kunešová, J. Pařízková, M. Wagenknecht, M. Hill, J. Drbohlav., and Obsahuje bibliografii a bibliografické odkazy
Previous data concerning the action of calcium (Ca) on gastric acid secretion (GAS) indicated that calcium ions increase GAS elicited by gastrin released through a vagal mechanism, and also by a direct effect on parietal cells. Our research showed that the stimulating effect of calcium on gastric acid secretion can be antagonized by verapamil administration, which reduces gastric acid secretion . In the present study we followed the effect induced by administration of calcium and Ca-chelating agents (disodium EDTA) on gastric acid secretion and on carbonic anhydrase (CA) activity. We selected two groups of healthy volunteers: Group I (n=21) received a single i.v. dose of CaCl2 (15 mg/kg b.w.), whereas Group II (n=22) received a single i.v. dose of disodium EDTA (5 mg/kg b.w.). We determined blood calcium before and after treatment, gastric acid secretion at 2 hours, erythrocyte CA II activity, and CA IV activity in membrane parietal cells, which were isolated from gastric mucosa obtained by endoscopic biopsy. Assessment of carbonic anhydrase activity was achieved by the stopped-flow method. In Group I calcium administration increased blood calcium, HCl output, CA II and CA IV activity as compared to initial values. In Group II, disodium EDTA reduced blood calcium, HCl output, CA II and CA IV activity as compared to initial values. The results demonstrated that increased blood calcium and GAS values after calcium administration correlated with the increase of erythrocyte CA II and parietal cell CA IV activity, while disodium EDTA induced a reversed process. Our results also show that cytosolic CA II and membrane CA IV values are sensitive to calcium changes and they directly depend on these levels. Our data suggest that intra- and extracellular pH changes induced by carbonic anhydrase might account for the modulation of the physiological and pathological secretory processes in the organism., I. Puscas, M. Coltau, M. Baican, G. Domuta, A. Hecht., and Obsahuje bibliografii
The rationale for the topical application of capsaicin and other vanilloids in the treatment of pain is that such compounds selectively excite and subsequently desensitize nociceptive neurons. This desensitization is triggered by the activation of vanilloid receptors (TRPV1), which leads to an elevation in intracellular free Ca2+ levels. Depending on the vanilloid concentration and duration of exposure, the Ca2+ influx via TRPV1 desensitizes the channels themselves, which may represent not only a feedback mechanism protecting the cell from toxic Ca2+ overload, but also likely contributes to the analgesic effects of capsaicin. This review summarizes the current state of knowledge concerning the mechanisms that underlie the acute capsaicin-induced Ca2+-dependent desensitization of TRPV1 channels and explores to what extent they may contribute to capsaicin-induced analgesia. In view of the polymodal nature of TRPV1, we illustrate how the channels behave in their desensitized state when activated by other stimuli such as noxious heat or depolarizing voltages. We also show that the desensitized channel can be strongly reactivated by capsaicin at concentrations higher than those previously used to desensitize it. We provide a possible explanation for a high incidence of adverse effects of topical capsaicin and point to a need for more accurate clinical criteria for employing it as a reliable remedy., L. Vyklický, K. Nováková-Toušová, J. Benedikt, A. Samad, F. Touška, V. Vlachová., and Obsahuje bibliografii a bibliografické odkazy