Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0024591 (malignant hyperthermia)
 2,353 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The King-Denborough syndrome (KDS) is characterized by dysmorphic features, myopathy, and malignant hyperthermia (MH). Physiologic contracture testing for MH susceptibility has not been reported in KDS. A young boy with KDS underwent muscle biopsy evaluation at age 3 years that documented an abnormal contracture response to halothane, indicating MH susceptibility. Histopathology demonstrated small type II fibers associated with type I hypertrophy. Contracture testing of muscle obtained from the patient's mother was positive, while a sibling's test was negative. This case is the first to demonstrate susceptibility to MH with KDS by using physiologic contracture testing. The presence of positive MH results in both the patient and his mother suggest one of the following: (1) KDS may be part of the spectrum of autosomal dominantly inherited MH; (2) the locus for MH and for KDS may be linked closely and inherited concurrently, or; (3) the association of MH and KDS may be coincidental.
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PMID:King-Denborough syndrome: contracture testing and literature review. 290 59

Sarcolemmal properties implicated in the skeletal muscle disorder, malignant hyperthermia (MH), were examined using sarcolemma-membrane vesicles isolated from normal and MH-susceptible (MHS) porcine skeletal muscle. MHS and normal sarcolemma did not differ in the distribution of the major proteins, cholesterol or phospholipid content, vesicle size and sidedness, (Na+ + K+)-ATPase activity, ouabain binding, or adenylate cyclase activity (total and isoproterenol sensitivity). The regulation of the initial rates of MHS and normal sarcolemmal ATP-dependent calcium transport (calcium uptake after 1 min) by Ca2+ (K1/2 = 0.64-0.81 microM), calmodulin, and cAMP-dependent protein kinase were similar. However, when sarcolemmal calcium content was measured at either 2 or 20 min after the initiation of active calcium transport, a significant difference between MHS and normal sarcolemmal calcium uptake became apparent, with MHS sarcolemma accumulating approximately 25% less calcium than normal sarcolemma. Calcium transport by MHS and normal sarcolemma, at 2 or 20 min, had a similar calmodulin dependence (C1/2 = 150 nM), and was stimulated to a similar extent by cAMP-dependent protein kinase or calmodulin. Halothane inhibited MHS and normal sarcolemmal active calcium uptake in a similar fashion (half-maximal inhibition at 10 mM halothane), while dantrolene (30 microM) and nitrendipine (1 microM) had little effect on either MHS or normal sarcolemmal calcium transport. After 20 min of ATP-supported calcium uptake, 2 mM EGTA plus 10 microM sodium orthovanadate were added to initiate sarcolemmal calcium efflux. Following an initial rapid phase of calcium release, an extended slow phase of calcium efflux (k = 0.012 min-1) was similar for both MHS and normal sarcolemma vesicles. We conclude that although a number of sarcolemmal properties, including passive calcium permeability, are normal in MH, a small but significant defect in MHS sarcolemmal ATP-dependent calcium transport may contribute to the abnormal calcium homeostasis and altered contractile properties of MHS skeletal muscle.
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PMID:Skeletal muscle sarcolemma in malignant hyperthermia: evidence for a defect in calcium regulation. 302 85

Malignant hyperthermia is a seemingly rare genetic myopathy. Hypermetabolic crisis accompanied by a rise in body temperature to as high as 44 degrees C is its hallmark. Malignant hyperthermia is usually triggered by potent inhalated anesthetics and/or depolarizing muscle relaxants. Because of the extraordinary risk of death in patients who are at risk, plastic surgeons may be reluctant to operate on these patients. Five such patients were referred to the Plastic Surgery Service and the UCLA Malignant Hyperthermia Center for anesthetic and surgical management following plastic surgical procedures aborted for first episodes of malignant hyperthermia. They were anesthetized with nitrous oxide, barbiturates, opiates, tranquilizers, and nondepolarizing muscle relaxants. The patients were not treated prophylactically with dantrolene. Cardiac monitoring, end-tidal pCO2, and rectal temperatures were followed. After completion of their plastic surgical procedures, all five patients had a vastus lateralis muscle biopsy performed and subsequent caffeine/halothane contracture studies completed. The contracture study was positive in all patients studied. No anesthetic or surgical complications were encountered. This study demonstrates that patients at risk of developing malignant hyperthermia crisis can have plastic surgical procedures performed safely while undergoing appropriately selected general anesthesia.
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PMID:Malignant hyperthermia in plastic surgery. 317 76

Six children of similar ethnic origin with congenital myopathy, cleft palate, malignant hyperthermia (or susceptibility to malignant hyperthermia), and skeletal anomalies are presented. The findings are remarkably consistent among our patients, 3 of whom were related. This syndrome is likely to be inherited as an autosomal recessive trait. Children with this disorder are likely to undergo surgery with general anesthesia for facial or skeletal deformities and should be recognized as predisposed to developing malignant hyperthermia.
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PMID:Congenital myopathy with cleft palate and increased susceptibility to malignant hyperthermia: King syndrome? 324 76

Susceptibility to malignant hyperthermia is a rare inherited myopathy. Hypermetabolic crises accompanied by a rise in body temperature to as high as 44 degrees C are the hallmark of malignant hyperthermia episodes. These are triggered by inhalational anesthetic agents or depolarizing muscle-relaxant drugs. A similar condition exists in pigs; however, in addition to drug-induced attacks, episodes of malignant hyperthermia occur in these animals as a result of stress. It has been proposed that stress-induced malignant hyperthermia occurs in man. The present paper presents a case of stress-induced malignant hyperthermia in a 21-year-old man in whom the inciting stress was a head injury.
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PMID:Stress-induced malignant hyperthermia in a head-injured patient. Case report. 333 48

Malignant hyperthermia (MH) is a seemingly rare genetic myopathy. Hypermetabolic crises accompanied by a rise in body temperature to as high as 44 degrees C are its hallmark. These are usually triggered by potent inhalation anesthetics or depolarizing muscle relaxants. Because of the extraordinary risk of death in patients who are at risk, otolaryngologists may be reluctant to operate on these patients. Ten such patients undergoing tonsillectomy and adenoidectomy, myringotomy with ventilation tube insertion, and nasal polypectomy were anesthetized with nitrous oxide, barbiturates, opiates, tranquilizers and non-depolarizing muscle relaxants without complication. The patients were not treated prophylactically with dantrolene. Cardiac monitoring and rectal temperatures were followed. All ten patients had vastus lateralis muscle biopsy performed and subsequent caffeine/halothane contracture studies completed. The contracture study was positive in eight out of the patients studied. No anesthetic or surgical complications were encountered. This study demonstrates that patients at risk of developing MH crisis can have otolaryngologic procedures performed safely while undergoing appropriately selected general anesthesia.
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PMID:Prospective management of malignant hyperthermia in the otolaryngological patient. 339 52

We studied the cases of fifteen patients who had central core disease, a non-progressive congenital myopathy that is usually inherited as an autosomal dominant trait. As infants, the patients had poor muscle tone and developmental delay, and as adolescents and adults, they had varying degrees of proximal muscle weakness and tended to use the Gower maneuver. The most common musculoskeletal problems were dislocation or subluxation of the hip, pes planus, and hypermobility of the joints. The most serious orthopaedic problems were in the hips: ten patients had a total of nine dislocations and six subluxations, nine being present at birth and six developing later. Only nine hips were stable after the initial treatment, and there was a propensity for hip-joint contractures. Scoliosis and patellar instability were also seen. Although patients who have central core disease have been reported to be at increased risk for malignant hyperthermia, this did not occur in our patients.
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PMID:Orthopaedic aspects of central core disease. 340 75

Malignant hyperthermia is a seemingly rare genetic myopathy. Hypermetabolic crisis accompanied by a rise in body temperature to as high as 44 degrees C is its hallmark. Malignant hyperthermia is usually triggered by potent inhaled anesthetics or depolarizing muscle relaxants. Because of the extraordinary risk of death in patients who are susceptible, neurosurgeons may be reluctant to operate on these patients. Three such patients were referred to the Neurosurgery Service and the UCLA Malignant Hyperthermia Center after neurosurgical procedures aborted for first episodes of malignant hyperthermia. They were anesthetized with nitrous oxide, barbiturates, opiates, tranquilizers, and nondepolarizing muscle relaxants. The patients were not treated prophylactically with dantrolene. Cardiac monitoring, end-tidal pCO2, and rectal temperatures were followed. After completion of the neurosurgical procedures, all three patients had a vastus lateralis muscle biopsy and subsequent caffeine/halothane contracture studies. The contracture study was positive in all patients. No anesthetic or surgical complication was encountered. This study demonstrates that neurosurgical procedures can be performed safely in patients at risk of developing malignant hyperthermia while they undergo appropriately selected general anesthesia.
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PMID:Neurosurgery in the malignant hyperthermia-susceptible patient. 341 64

Malignant hyperthermia (MH) is a hereditary myopathy, triggered when susceptible patients are exposed to a depolarizing muscle relaxant and/or potent volatile anesthetics. We have studied the effects of dantrolene on the free [Ca2+]i of intercostal muscle biopsies obtained from two MH-susceptible patients before and after administration of dantrolene orally (2.5 mg/kg for 3 days) and intravenously (1.0 mg/kg 2 hours before the biopsy). The free [Ca2+]i was measured by Ca2+-selective microelectrodes. The mean resting free [Ca2+]i in the MH-susceptible muscle before dantrolene treatment was 0.42 +/- 0.01 microM (mean +/- SEM, n = 12). The administration of dantrolene reduced this value to 0.27 +/- 0.01 microM (n = 14). There was no detectable difference in the resting membrane potential after dantrolene. These results represent the first direct demonstration that dantrolene is able to reduce the resting free [Ca2+]i in skeletal muscle of MH-susceptible patients.
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PMID:Dantrolene sodium is able to reduce the resting ionic [Ca2+]i in muscle from humans with malignant hyperthermia. 356 41

The content and distribution of acetylcholinesterase (AChE) activity in the skeletal muscle disorder malignant hyperthermia (MH) was examined. The AChE activity of sarcolemma membranes isolated from MH-susceptible (MHS) swine was increased twofold when compared with normal sarcolemma. The total AChE activity of muscle extracts was also doubled in MHS tissue; however, the relative distribution between low-salt extractable (globular forms) and high-salt extractable (asymmetric forms) AChE activities were similar in MHS and normal muscle. Our results suggest that, for as yet unexplained reasons, both the sarcolemmal and total AChE activity of skeletal muscle is increased in porcine MH.
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PMID:Increased skeletal muscle acetylcholinesterase activity in porcine malignant hyperthermia. 368 45


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