Faqja 1 nga 54 rezultatet
BACKGROUND
Skeletal muscle fibers from malignant hyperthermia (MH)-susceptible humans and swine are markedly more sensitive to ryanodine receptor (RyR1) agonists than those from normal individuals. Reproducible shifts in the dose-response of skeletal muscle to caffeine and halothane are the basis of
Malignant hyperthermia (MH) is an autosomal-dominant disorder of skeletal muscle, triggered by volatile anaesthetics and depolarizing muscle relaxants. The causative defect lies in the control of Ca(2+) release from the sarcoplasmic reticulum in skeletal muscle. Numerous mutations have been detected
BACKGROUND
The preservative 4-chloro-m-cresol (4CmC) is a specific activator of sarcoplasmic Ca2- release and induces contractures in skeletal muscles of malignant hyperthermia susceptible (MHS) patients in vitro. Clinical formulas of heparin contain 4CmC. We studied whether (a) these heparin
OBJECTIVE
The in vitro contracture test with halothane and caffeine is the gold standard for the diagnosis of susceptibility to malignant hyperthermia (MH). However, the sensitivity of the in vitro contracture test is between 97 and 99% and its specificity is 78-94% with the consequence that
BACKGROUND
Chlorocresols are used as preservatives in numerous commercial drugs that have been shown to induce myoplasmic Ca2+ release; the most potent isoform is 4-chloro-m-cresol. The aims of this study were to (1) examine the in vivo effects of 4-chloro-m-cresol on swine susceptible to malignant
Malignant hyperthermia (MH) is an inherited skeletal muscle disorder triggered by commonly used anesthetics. Mutated ryanodine receptors have been identified as molecular targets. The sensitivity of myotubes from individuals classified by the in vitro contracture test as MH susceptible (MHS), normal
Standardization of the in vitro contracture test (IVCT) for malignant hyperthermia (MH) susceptibility has resulted in very rare false negative tests. However, false positive results stigmatizing the patient seem to be more frequent than false negative results and make supplementary tests desirable.
To clarify the contracture response to 4-chloro-m-cresol (4-CmC) in malignant hyperthermia (MH) equivocal (MHE) muscle, we studied the effect of cumulative concentrations of 4-CmC. In vitro contracture test (IVCT) was performed in 35 probands according to the European MH test protocol. Surplus
OBJECTIVE
4-chloro-m-cresol (4-CmC), commonly used as preservative, has been shown to induce contractures in skeletal muscle specimens from individuals susceptible to malignant hyperthermia (MH). It has been suggested that a defect of the calcium release channel of the skeletal muscle sarcoplasmic
Malignant hyperthermia (MH) is a potentially fatal pharmacogenetic syndrome caused by exposure to halogenated volatile anesthetics and/or depolarizing muscle relaxants. We have measured intracellular Ca(2+) concentration ([Ca(2+)](i)) using double-barreled, Ca(2+)-selective microelectrodes in
BACKGROUND
4-Chloro-m-cresol (4-CmC) induces marked contractures in skeletal muscle specimens from individuals susceptible to malignant hyperthermia (MHS). In contrast, 4-CmC induces only small contractures in specimens from normal (MHN) patients. 4-CmC is a preservative within a large number of
BACKGROUND
In vitro contracture test (IVCT) for diagnosis of MH in our laboratory has a sensitivity of 100% and a specificity of 93%. The results are equivocal in 10-15%, and supplementary tests may thus be required. We have tested the hypothesis that 4-chloro-m-cresol (4-cmc) may be useful for a
Single-channel recordings have indicated that ryanodine receptor (RyR1) mutation Arg615Cys of porcine malignant hyperthermia-susceptible (MHS) muscle is not directly associated with the enhanced caffeine sensitivity of MH(S) muscle [1]. In the present study, the effect of a novel activator of RyR1,
Purpose: This study aimed to evaluate whether the three ryanodine receptor type 1 (RYR1) variants (p.Ser2345Thr, p.Ser2345Arg, and p.Lys3367Arg) which we identified in Japanese malignant hyperthermia (MH) patients with a clinical grading
Malignant hyperthermia is an inherited autosomal disorder of skeletal muscle in which certain volatile anesthetics and depolarizing muscle relaxants trigger an abnormally high release of Ca2+ from the intracellular Ca2+ store, the sarcoplasmic reticulum. In about 50% of cases, malignant hyperthermia