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)

Acute lymphatic leukemia (ALL) represents one of the most frequent malignancies in childhood. Central venous access ports or partly implanted silicone catheters are usually placed for high-dose chemotherapy in these children. We report two patients aged 7 and 3 years with acute lymphoblastic beta-cell leukemia (B-ALL), a less common subtype of ALL, which presented with hyperthermia (38.4 degrees C and 39 degrees C) during anesthesia with isoflurane for implantation of a central venous catheter. The hyperthermic reactions were accompanied by an increase in expired CO2 and acidosis as well as moderate elevation of heart rate and blood pressure. As in both patients the history and preoperative findings did not reveal signs of infection or other causes of fever, the observed alterations were interpreted as symptoms of malignant hyperthermia triggered either by succinylcholine or isoflurane, which were used in both children. In addition, the hyperthermia responded to administration of dantrolene sodium according to dose recommendations for treatment of malignant hyperthermia. In one of the patients, withdrawal of dantrolene during the initial postoperative hours was followed by a recurrent increase in body temperature, which once again could be suppressed by additional dantrolene infusion. According to the literature, malignant hyperthermia has occasionally been described in children with malignancies such as leukemia or Burkitt's lymphoma. Our observations indicate that children with B-ALL may be especially susceptible to malignant hyperthermia. Close monitoring of body temperature and expiratory CO2 are therefore indicated in these children, and dantrolene therapy should be started immediately in case of increased temperature during anesthesia.
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PMID:[Hyperthermic reaction in the perioperative phase in 2 children with acute lymphoblastic leukemia of B-cell type]. 292 70

To investigate possible abnormalities in erythrocyte membrane enzyme activities in the pharmacogenetic disorder MH, membrane ATPase activities have been examined in erythrocyte ghosts prepared from red blood cells of MHS and normal swine. While no differences were noted in Mg2+-ATPase activities, the (Na+, K+)-ATPase activity of MHS erythrocyte ghosts was less than that of normal ghosts. Ca2+-ATPase activity exhibited low- and high-affinity Ca2+-binding sites in both types of erythrocyte ghost. While the Km for Ca2+ was greater for normal than for MHS erythrocyte ghosts at the high-affinity Ca2+-binding site, the reverse was true at the low-affinity Ca2+-binding site. Irrespective of the type of calcium binding site occupied, the Vmax for normal erythrocyte ghost Ca2+-ATPase activity was greater than that for MHS ghosts. In the presence of calmodulin, there was now no difference between MHS and normal erythrocyte ghosts in either the Km for Ca2+ or the Vmax of the Ca2+-ATPase activity. To determine if the calcium pumping activity of intact MHS and normal pig erythrocytes differed, calcium efflux from the 45Ca-loaded erythrocytes was determined; this activity was significantly greater for MHS than for normal erythrocytes. Thus, the present study confirms that there are abnormalities in the membranes of MHS pig red blood cells. However, we conclude that these abnormalities are unlikely to result in an impaired ability of MHS erythrocytes to regulate their cytosolic Ca2+ concentration.
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PMID:Erythrocyte membrane ATPase and calcium pumping activities in porcine malignant hyperthermia. 296 54

This is the first report of a case of malignant hyperthermia (MH) from Saudi Arabia. MH was probably triggered by response to Halothane. The diagnosis was suspected by the clinical signs of tachycardia, severe rigidity, cyanosis and rising temperature. The case was successfully managed by vigorous cooling, dantrolene sodium and diuresis.
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PMID:Malignant hyperthermia in a Saudi child. 299 70

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

Tonsillectomy in adults and older children is typically accompanied by 7 to 14 days of pain. On the basis of clinical observations of patients treated perioperatively with dantrolene sodium for malignant hyperthermia, we hypothesized that pharyngeal muscle spasms are a major factor in tonsillectomy pain. We entered 113 patients, 11 years of age and older, into a double-blind, placebo-controlled study to evaluate the effectiveness of dantrolene sodium in reduction of tonsillectomy pain. Patients were randomly assigned either dantrolene (1.5 mg/kg per day) or placebo orally four times a day for 5 days postoperatively. On a standardized questionnaire, the patient recorded pain, diet, activity level, analgesics, and side effects, daily for 2 weeks. Also, alkaline phosphatase (alk phos) and serum aspartate aminotransferase (SGOT) levels were determined before the operation and 2 weeks after. Patients who received dantrolene had no significant differences in subjective pain, diet, or activity level scores from those of patients who received placebo. Dantrolene patients did, however, require significantly less analgesic use than placebo patients (p = 0.034, 0.015, and 0.005 for postoperative days 2, 3, and 4, respectively). There was no significant difference in side effects or changes in liver enzyme between the dantrolene and placebo groups. We conclude that dantrolene sodium, given in the dosage noted, is effective in reduction of analgesic requirements after tonsillectomy.
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PMID:Oral dantrolene sodium for tonsillectomy pain: a double-blind study. 312 47

Twenty malignant hyperthermia-susceptible pregnant patients were given dantrolene sodium orally for 5 days before delivery and 3 days after delivery. When cesarean section was necessary, triggering agents were avoided. No patient had a malignant hyperthermia reaction. No adverse effect of dantrolene sodium was detected by extensive testing of the fetus and neonate. The maternal predelivery dantrolene level was correlated with the noenatal cord blood dantrolene level (r = 0.837). The mean maternal predelivery dantrolene level was 0.99 +/- 0.5 microgram/ml, and the mean neonatal cord blood dantrolene level 0.68 +/- 0.3 microgram/ml. The time from the last dose of dantrolene to delivery was correlated with both the maternal dantrolene level and the neonatal cord blood level (r = 0.65). The half-life of dantrolene in the neonatal circulation was 20 hours. The controversy of oral dantrolene prophylaxis and the implications of this study with regard to further investigation are discussed.
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PMID:Dantrolene in pregnancy: lack of adverse effects on the fetus and newborn infant. 317 31

A 53 year old obese male presented with the signs and symptoms of acute appendicitis and a family history suggesting the possibility of a malignant hyperthermia trait. In spite of spinal anaesthesia the patient developed malignant hyperthermia during the appendicectomy and the attack was successfully aborted with the early use of dantrolene sodium (Dantrium, Norwich Eaton).
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PMID:Malignant hyperthermia and the conscious patient. 317 98

Two cases are presented of malignant hyperthermia in black patients. One patient developed signs of malignant hyperthermia during general anesthesia that was successfully treated with dantrolene sodium and cooling. A second patient was retrospectively diagnosed as having an atypical variant of malignant hyperthermia secondary to heat stroke and general anesthesia; this patient subsequently died. These cases illustrate that malignant hyperthermia can occur in blacks despite the very low incidence of this syndrome in nonwhite patients.
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PMID:Typical and atypical presentation of malignant hyperpyrexia in nonwhite patients. 325 Feb 81

The differences observed among rat strains in both basal [Na+]i and the several cation transport systems seem to be due to the different genetic background as clearly shown in F2 populations or after bone marrow transplantation in MHS. The same may be true for humans. In spite of all the caution taken in interpreting the data, because of the great possibility of methodological errors, it is likely that the differences observed in many laboratories are due to uneven genetic or ethnic composition of the samples studied, as shown by Dagher and Canessa. One intriguing observation is that most reports of "low Na-K cotransport" values in hypertensive patients are from Mediterranean countries (Italy, France, and Spain), whereas most reports of "high," or "not low Na-K cotransport," or very high values of countertransport came from populations originating from North Europe (Denmark, USA, South African whites). We are not aware of any study on erythrocyte Na-K cotransport performed in Great Britain (the greatest source of American immigrants). Indeed the difference in cotransport values between North and South European hypertensives might be due to different environmental factors, but if this is so, the difference does not depend on the salt consumption or plasma lipids that are similar in our high and low Na-K cotransport hypertensives (Cusi D et al, submitted). The picture seems relatively less confusing for calcium. The most consistent alterations in different models of hypertension is a decreased Ca-pump in SHR, MHS, and DOCA rats, reduced calcium binding in SHR and MHS, and reduced microsomal ATP dependent calcium uptake in SHR and DOCA rats. [Ca++]i, which is increased in established hypertension in man and rats, is normal in young prehypertensive rats and humans, and returns to normal values after pharmacological treatment of hypertension. This pattern of changes suggests that genetic control of these transport systems is weaker, and probably much influenced by different environmental conditions. However, because of the pivotal role of calcium in vascular smooth muscle cell concentration, its intracellular increase may be the common pathway of the different forms of hypertension. What remains unclear is the relation, if any, between calcium and sodium. Blaustein tried to find a link between them, but his hypotheses have yet to be confirmed.
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PMID:Role of cellular sodium and calcium metabolism in the pathogenesis of essential hypertension. 329 35

Erythrocyte membrane 22Na and 45Ca transport, osmotic stability and antigenic composition were investigated in 3 strains of rats with spontaneous hereditary hypertension (SHR, SHR SP, MHS), as well as normotensive controls for SHR and SHR SP (WKY) and for MHS (MHS). All strains of spontaneously hypertensive rats showed increased passive membrane permeability for sodium, that was due to increased operation rate of the Na+, K+-cotransport system. Metabolizing sodium is increased in the erythrocytes of Japanese rats (SHR and SHR SP), and decreased in Milan rats (MHS), as compared to normotensive controls. After four hours of incubation with orthovanadate, erythrocyte 45Ca levels were 2-3 times as high in SHR and SHR SP as they were in WKY. In the presence of valinomycin, erythrocyte resistance to hypoosmotic hemolysis was essentially higher in SHR and SHR SP than it was in WKY. These differences are related to a changed rate of anion transport through the band 3 protein. There were no differences in this respect between MHS and MNS. An antigen with a molecular weight of 37-39 kD was detected in erythrocyte membranes of WKY and could not be detected in erythrocytes of other rat groups, including the MNS. It is suggested that different molecular origins of membrane disorders may be an immediate cause of different mechanisms of arterial hypertension in Japanese and Milan animals.
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PMID:[Characteristics of the structural-functional status of erythrocyte membranes in 3 strains of rats with spontaneous genetic hypertension]. 335 98


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