The High-Mobility Group Box 1 protein (HMGB1) is a known nuclear protein which may be released from the nucleus into the cytoplasm and the extracellular space. It is believed that the mobilized HMGB1 plays role in the autoimmune processes as an alarmin, stimulating the immune response. In addition, muscle regeneration and differentiation may also be altered in the inflammatory surroundings.
View Article and Find Full Text PDFJ Muscle Res Cell Motil
March 2012
Although statins, the most widely used drugs in the treatment of hyperlipidaemia, are generally accepted as efficient and safe drugs their side-effects on skeletal muscle have been reported with increasing frequency. The lack of an animal model in which these side effects would consistently be observed is one of the important drawbacks in studying statin associated myopathy. To overcome this and enable the studying of the effects of fluvastatin on skeletal muscles an animal model with high blood cholesterol levels was developed.
View Article and Find Full Text PDFAlthough the alteration of purinoreceptor pattern on skeletal muscle is known to accompany physiological muscle differentiation and the pathogenesis of muscle dystrophy, the exact identity of and the relative contribution from the individual receptor subtypes to the purinergic signal have been controversial. To identify these subtypes in cultured myotubes of 5-10 nuclei, changes in intracellular calcium concentration and surface membrane ionic currents were detected and calcium fluxes calculated after the application of the subtype-specific agonists 2'3'-O-(benzoyl-4-benzoyl)-ATP (BzATP), 2-methyltio-ADP and UTP. The effectiveness of these agonists together with positive immunocytochemical staining revealed the presence of P2X(4), P2X(5), P2X(7), P2Y(1) and P2Y(4) receptors.
View Article and Find Full Text PDFAlthough extracellular adenosine triphosphate (ATP) has been generally accepted as the regulator of cellular differentiation, the relative contribution of the various purinoreceptor subtypes to purinergic signalling at distinct stages of skeletal muscle differentiation is still poorly understood. Here we measured extracellular ATP-evoked changes in intracellular calcium concentration and surface membrane ionic currents (I (ATP)), calculated the calcium flux (FL) entering the myoplasmic space and compared these parameters at different stages of differentiation on cultured mouse myotubes. The ATP-evoked FL displayed an early peak and then declined to a steady level.
View Article and Find Full Text PDFMaurocalcine (MCa), a 33 amino acid toxin obtained from scorpion venom, has been shown to interact with the isolated skeletal-type ryanodine receptor (RyR1) and to strongly modify its calcium channel gating. In this study, we explored the effects of MCa on RyR1 in situ to establish whether the functional interaction of RyR1 with the voltage-sensing dihydropyridine receptor (DHPR) would modify the ability of MCa to interact with RyR1. In developing skeletal muscle cells the addition of MCa into the external medium induced a calcium transient resulting from RyR1 activation and strongly inhibited the effect of the RyR1 agonist chloro-m-cresol.
View Article and Find Full Text PDFA 24-year old female, gravida III, para III, delivered a full-term infant by cesarean section. A maternal blood sample at the time of admission showed antibody in her serum that had apparent anti-e specificity and that her RBCs were e+. Further studies determined that the antibody was anti-hrS.
View Article and Find Full Text PDFAn immune complex mechanism for ceftriaxone sodium- induced severe autoimmune hemolytic anemia has previously been demonstrated using routine blood bank techniques. We describe herein a patient with severe hemolysis that subsided once the drug was discontinued. Serologic techniques demonstrated immune complex-mediated ceftriaxone-dependent red cell antibodies.
View Article and Find Full Text PDFChanges in intracellular calcium concentration ([Ca2+]i) evoked by prolonged depolarisation (120 mM KCl) or by the application of 15 mM caffeine were measured on skeletal muscle cells in primary culture. The extrusion rate (PVmax) of calcium from the myoplasm was determined, which in turn enabled the calculation of the calcium flux (Fl) underlying the measured calcium transients. PVmax was found to increase during differentiation, from 107 +/- 10 microM/s at the early myotube stage to 596 +/- 36 microM/s in secondary myotubes.
View Article and Find Full Text PDFThe effects of thymol on steps of excitation-contraction coupling were studied on fast-twitch muscles of rodents. Thymol was found to increase the depolarization-induced release of calcium from the sarcoplasmic reticulum, which could not be attributed to a decreased calcium-dependent inactivation of calcium release channels/ryanodine receptors or altered intramembrane charge movement, but rather to a more efficient coupling of depolarization to channel opening. Thymol increased ryanodine binding to heavy sarcoplasmic reticulum vesicles, with a half-activating concentration of 144 micro M and a Hill coefficient of 1.
View Article and Find Full Text PDFBezoars are concretions of foreign materials in the stomach, small intestine or bowel in people or animals, which impair GIT motility or cause intestinal obstruction. The authors describe an interesting case report of a 30-year-old imbecile with manifestation of simultaneous bezoar of stomach, ileum and caecum and its operative treatment. They describe a short characteristics of this clinical unit, which is reported in the literature only in a few case reports.
View Article and Find Full Text PDFThe authors retrospectively analyse a group (1991-2000) of 129 patients with malignancies of the stomach operated at the Surgical Department of The District Hospital in Lucenec. The operated patients were: males 83 (64%), females 46 (36%), mean age--63.4 years.
View Article and Find Full Text PDFAuthors refer about their experiences with operations of acute cholecystitis by laparoscopy. They have evaluated retrospectively 1600 cases of laparoscopic cholecystectomies (LCHE) realized in the period from 1994 to 2000. In 302 (18.
View Article and Find Full Text PDFThe effects of adenosine 5'-triphosphate (ATP) on human and mouse skeletal muscle fibres in primary culture were investigated. ATP-evoked changes in intracellular calcium concentration ([Ca(2+)](i)) were measured and compared with those induced by agonists of the nicotinic acetylcholine (Ach)- and P2X purinoreceptors. While ATP was effective on both myoblasts and multi-nucleated myotubes in the micromolar range, Ach failed to induce any change in [Ca(2+)](i) at early stages of development.
View Article and Find Full Text PDFThe authors present a review of revascularisation and reconstruction operations for arteriosclerosis in a group of 2341 patients (1754 (75%) operations). Direct reconstruction operations were made 825 times (47%), indirect operations--sympathectomy 598 times (34.1%) and endovascular intervention 331 times (18.
View Article and Find Full Text PDFJ Muscle Res Cell Motil
December 1996
The effects of low (10-100 microM) concentrations of tetracaine on intermembrane charge movement and on the rate of calcium release (Rrel) from the sarcoplasmic reticulum (SR) were studied in cut skeletal muscle fibres of the frog using the voltage clamp technique. The fibres were mounted in a single or double vaseline gap chamber to study the events near the contraction threshold or in a wide membrane potential range. Although the 'hump' component of charge movement (Q gamma) was suppressed to some extent, the voltage dependence and the parameters of the Boltzmann distribution were not modified significantly at tetracaine concentrations below 50 microM.
View Article and Find Full Text PDFActa Physiol Hung
June 1987
The effects of phlorizin on the membrane potential changes induced by cevadine were compared in the presence and absence of external chloride anions in frog skeletal muscle. The action of the drug on 24Na-efflux was also studied in chloride-free medium. In accordance with previous results, it was found that phlorizin reduced the frequency of the membrane potential oscillation (1 mmol/l) or fully inhibited the rhythmic activity (2 mmol/l) in the presence of chloride anions.
View Article and Find Full Text PDFThe effects of phlorizin and phloretin on the cable properties were investigated in frog sartorius muscle by conventional cable analysis. Actions of phloretin on voltage-dependent ionic conductances were also studied by analysis of the phase plane trajectories. Both drugs evoked a significant decrease in specific membrane resistance (Rm) in chloride-containing Ringer's solution.
View Article and Find Full Text PDFActa Physiol Hung
October 1986
The effects of phlorizin (2 X 10(-3) mol X l-1) on the Na transport of frog (Rana esculenta) sartorius muscle were investigated in glucose-free medium. Phlorizin decreased the rate coefficient of 24Na efflux by about 40%. The degree of inhibition was comparable to that caused by ouabain (10(-4) mol X l-1).
View Article and Find Full Text PDFThe effect of phlorizin on the parameters of cevadine induced membrane potential oscillation and the development of the potential changes were investigated in frog (Rana esculenta) sartorius muscles. The action of phlorizin on Na transport, water and cation contents of cevadine-treated muscles were also studied. On the effect of phlorizin applied at a concentration of 1 mmol/1 the frequency of the membrane potential oscillation evoked by cevadine decreased by about half, parallel with an about four-fold increase in the duration of the resting period and the prepotential.
View Article and Find Full Text PDFCevadine-induced changes in membrane potential, sodium transport, intracellular Na, K, and water content were investigated in sartorius muscles incubated in chloride-free (glutamate) Ringer. Cevadine sensitivity of muscles incubated in glutamate Ringer was about five times greater than that of muscles incubated in normal Ringer. Therefore, even 0.
View Article and Find Full Text PDFActa Physiol Hung
November 1984
The effects of phlorizin on the action potential and voltage-dependent ionic conductances were investigated in frog (Rana esculenta) sartorius muscles. In order to study the ionic currents, phase plane trajectories of the action potentials were analysed. As a consequence of lowering the overshoot by 19%, the amplitude of the action potential was decreased on the effect of phlorizin applied at a concentration of 2 mmol/l.
View Article and Find Full Text PDFActa Physiol Hung
January 1984
The voltage dependent ionic conductances were studied by analysing the phase plane trajectories of action potentials evoked by electrical stimulation of the sartorius muscles of the frog (Rana esculenta). The delayed outward potassium current was measured also under voltage clamp conditions on muscle fibres of either the frog (Rana esculenta) or Xenopus laevis. On analysing the effect of physostigmine decreasing the peak amplitude, the rate of both the rising and falling phases of the action potentials, it was revealed that the alkaloid at a concentration of 1 mmol/l reduced significantly both the delayed potassium conductance and the outward ionic current values during the action potentials.
View Article and Find Full Text PDFActa Physiol Acad Sci Hung
December 1982
The dependence of the membrane potential oscillation induced by cevadine on the actual transmembrane potential was studied in the frog sartorius muscle. 1. If the membrane potential oscillation is recorded for hours, its amplitude is seen to decrease slowly and smoothly and the membrane potential measured during the resting period among the waves of oscillation also decreases simultaneously.
View Article and Find Full Text PDFActa Physiol Acad Sci Hung
June 1982
1. The sensitizing effect of veratrum alkaloids to potassium is not specific. Reducing the concentration of chloride in Ringer's solution, or treating the muscle with nicotine in a concentration close to threshold after pretreatment with subliminal concentration of cevadine result in a marked mechanical response of the muscle.
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