Whittaker M

General

Full name : Whittaker Mary

First name : Mary

Mail : Department of Environmental Sciences, Polytechnic South West. Drakes Circus, Plymouth. Devon. PL4 8AA

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Country : United Kingdom

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References (75)

Title : Poster: Immunological studies of the apparent silent homozygotes for plasma cholinesterase using an ELISA technique -
Author(s) : Whittaker M , Jones JW
Ref : In: Cholinesterases: Structure, Function, Mechanism, Genetics, and Cell Biology , (Massoulie J, Barnard EA, Chatonnet A, Bacou F, Doctor BP, Quinn DM) American Chemical Society, Washington, DC :200 , 1991
PubMedID:

Title : Poster: Immunological studies of the plasma cholinesterase variants -
Author(s) : Mortensen V , Rasmussen-Loft AG , Norgaard-Pedersen B , Jones JW , Whittaker M
Ref : In: Cholinesterases: Structure, Function, Mechanism, Genetics, and Cell Biology , (Massoulie J, Barnard EA, Chatonnet A, Bacou F, Doctor BP, Quinn DM) American Chemical Society, Washington, DC :199 , 1991
PubMedID:

Title : Immunological studies of families segregating the silent gene for plasma cholinesterase - Whittaker_1991_Hum.Hered_41_77
Author(s) : Whittaker M , Jones JW , Braven J
Ref : Hum Hered , 41 :77 , 1991
Abstract : Seven families segregating apparently silent gene homozygotes have been investigated by enzyme-linked immunosorbent assays. These families confirm not only the heterogeneity of the silent gene in the form of E1s and E1t but in 3 families there is support for the segregation of the new gene E1x.
ESTHER : Whittaker_1991_Hum.Hered_41_77
PubMedSearch : Whittaker_1991_Hum.Hered_41_77
PubMedID: 1855785

Title : Quantification and phenotyping of serum cholinesterase by enzyme antigen immunoassay: methodological aspects and clinical applicability - Hangaard_1991_Scand.J.Clin.Lab.Invest_51_349
Author(s) : Hangaard J , Whittaker M , Rasmussen-Loft AG , Norgaard-Pedersen B
Ref : Scand J Clin Lab Invest , 51 :349 , 1991
Abstract : An enzyme antigen immunoassay for a specific determination of serum cholinesterase is described. Polyclonal and monoclonal antibodies against cholinesterase have been used. Hydrophobic binding of the specific antibody to a microtitre plate was followed by incubation with the samples, and the activity of the bound cholinesterase was assayed by the Ellman method. The procedure has been optimized and characterized, with respect to antigen specificity, and the applicability of the assay for cholinesterase phenotyping is demonstrated. The cholinesterase activities, dibucaine-, scoline-, fluoride- and urea numbers were comparable with established reference values. The high sensitivity and specificity of the assay has been used for determination of cholinesterase in amniotic and cerebrospinal fluids, and its applicability in clinical medicine is indicated.
ESTHER : Hangaard_1991_Scand.J.Clin.Lab.Invest_51_349
PubMedSearch : Hangaard_1991_Scand.J.Clin.Lab.Invest_51_349
PubMedID: 1947720

Title : Immunological studies of plasma cholinesterase during pregnancy and the puerperium -
Author(s) : Whittaker M , Jones JW , Braven J
Ref : Clinica Chimica Acta , 199 :223 , 1991
PubMedID: 1769108

Title : Immunological assay of erythrocyte acetylcholinesterase - Jones_1991_Clin.Chim.Acta_200_175
Author(s) : Jones JW , Whittaker M , Braven J
Ref : Clinica Chimica Acta , 200 :175 , 1991
Abstract : An immunoassay for the quantitation of erythrocyte surface acetylcholinesterase is described; using a red cell suspension, bound mouse monoclonal acetylcholinesterase antibody is detected by an alkaline phosphatase conjugated rabbit anti mouse IgG. Extraction is not required. In addition, the activity of erythrocyte surface acetylcholinesterase using dithiobisnitrobenzoate to detect released thiocholine has been measured. The coefficient of variation for each method is 7%. Reference ranges have been established for healthy adults and cord blood.
ESTHER : Jones_1991_Clin.Chim.Acta_200_175
PubMedSearch : Jones_1991_Clin.Chim.Acta_200_175
PubMedID: 1777967

Title : Cholinesterase deficiency and the Churg-Strauss syndrome - Taylor_1990_Anaesthesia_45_649
Author(s) : Taylor BL , Whittaker M , Van Heerden V , Britten J
Ref : Anaesthesia , 45 :649 , 1990
Abstract : We report two patients with the Churg-Strauss syndrome who were found to have decreased cholinesterase activity despite normal phenotypes. Suspicion of abnormal sensitivity to suxamethonium in the first case was raised after prolonged paralysis under anaesthesia. The findings in the second were incidental during the course of intensive care treatment. Both patients received immunosuppressive therapy. Differentiation between the effects of this and the disease process itself cannot be established.
ESTHER : Taylor_1990_Anaesthesia_45_649
PubMedSearch : Taylor_1990_Anaesthesia_45_649
PubMedID: 2400076

Title : Recognition of the Ek1Ek1 homozygote for plasma cholinesterase - Whittaker_1990_Hum.Hered_40_247
Author(s) : Whittaker M , Britten JJ
Ref : Hum Hered , 40 :247 , 1990
Abstract : A family is reported in which the propositus was found to be sensitive to suxamethonium. Both parents were heterozygote each having genotype Ea1Ek1. The sibling of the propositus had the most common phenotype as defined by dibucaine, fluoride and RO2 numbers. Genetic analysis, however, indicated that this sibling must be an Ek1Ek1 homozygote.
ESTHER : Whittaker_1990_Hum.Hered_40_247
PubMedSearch : Whittaker_1990_Hum.Hered_40_247
PubMedID: 2379931

Title : Heterogeneity of the silent gene for plasma cholinesterase. Immunological studies - Whittaker_1990_Hum.Hered_40_153
Author(s) : Whittaker M , Jones J , Braven J
Ref : Hum Hered , 40 :153 , 1990
Abstract : Rocket immuno-electrophoresis and enzyme-linked immunosorbent assays were used to estimate the amount of cholinesterase present in 29 apparent silent homozygotes. 26 of these samples were segregated into four groups representing zero, very low, low and high levels of immunoreactive protein. These groups may represent the genotypes E1sE1s, E1sE1t, E1tE1t and a new genotype E1xE1x, respectively. The possible genotypes of the remaining 3 individuals are discussed.
ESTHER : Whittaker_1990_Hum.Hered_40_153
PubMedSearch : Whittaker_1990_Hum.Hered_40_153
PubMedID: 2365375

Title : Activation of glycogen phosphorylase in rat pheochromocytoma PC12 cells and isolated hepatocytes by organophosphates - Kauffman_1990_Biochem.Pharmacol_39_347
Author(s) : Kauffman FC , Davis LH , Whittaker M
Ref : Biochemical Pharmacology , 39 :347 , 1990
Abstract : Several organophosphates including diisopropylfluorophosphonate (DPF) and a variety of compounds used as chemical warfare agents produced dose- and time-dependent increases in phosphorylase-a, the phosphorylated form of glycogen phosphorylase in rat pheochromocytoma cells, PC12, and isolated hepatocytes. Increases in phosphorylase-a did not occur in cells exposed to the carbamates, physostigmine or pyridostigmine, or to O-ethyl S-2-diisopropylaminoethylmethyl-phosphonathiolate (VX), an organophosphate which is protonated at physiological pH. When extracellular pH was increased to pH 8, VX acted like the other organophosphates and increased phosphorylase-a activity. The possibility that organophosphates increase phosphorylase-a in intact cells by releasing Ca2+ from intracellular binding sites is supported by the following findings: organophosphate-induced increases in phosphorylase-a did not correlate with changes in cyclic AMP in the two cell types studied; in PC12 cells, increases in this activity occurred in the absence of extracellular calcium and were not inhibited by the calcium channel blocker, verapamil; fluorescence of the calcium sensitive dye, Quin-2, in PC12 cells preloaded with the acetoxymethyl ester of the dye was increased by soman; finally, addition of the calcium ionophore, A23187, to PC12 cells maintained in calcium-free medium caused sarin-stimulated phosphorylase-a activity to return rapidly to basal levels. Collectively, these data argue strongly that organophosphates increase phosphorylase-a activity in intact cells via a novel mechanism involving release of calcium from intracellular binding sites.
ESTHER : Kauffman_1990_Biochem.Pharmacol_39_347
PubMedSearch : Kauffman_1990_Biochem.Pharmacol_39_347
PubMedID: 2302257

Title : Inheritance of low plasma cholinesterase activity in two families with a history of suxamethonium sensitivity [see comments] - Whittaker_1989_Anaesthesia_44_480
Author(s) : Whittaker M , Berry M , Britten JJ
Ref : Anaesthesia , 44 :480 , 1989
Abstract : An hypothesis advanced in 1970 concerning family inheritance of low enzymic activities of plasma cholinesterase has been substantiated. The recognition of three E1kE1s genotypes is reported in this family after investigation of a new generation. A second family with similar genetic characteristics is described.
ESTHER : Whittaker_1989_Anaesthesia_44_480
PubMedSearch : Whittaker_1989_Anaesthesia_44_480
PubMedID: 2757153

Title : Segregation of the E1j gene for plasma cholinesterase in family studies - Whittaker_1989_Hum.Hered_39_1
Author(s) : Whittaker M , Britten JJ
Ref : Hum Hered , 39 :1 , 1989
Abstract : Four families are reported in which the E1j gene is segregating. Two E1jE1k and one E1jE1f genotypes have been recognised by genetic analysis. The biochemical characteristics of several E1j genotypes are presented.
ESTHER : Whittaker_1989_Hum.Hered_39_1
PubMedSearch : Whittaker_1989_Hum.Hered_39_1
PubMedID: 2759619

Title : Family studies of the E1kE1s genotype for plasma cholinesterase - Whittaker_1988_Hum.Hered_38_228
Author(s) : Whittaker M , Britten JJ , Vyas AB , Hayes TC
Ref : Hum Hered , 38 :228 , 1988
Abstract : Six individuals in three families with a history of suxamethonium sensitivity have been found to have genotype E1kE1s. The biochemical data for the recognition of this genotype have been analysed and the mean values compared with similar parameters for the usual phenotype. Individuals with genotype E1kE1s will be sensitive to suxamethonium.
ESTHER : Whittaker_1988_Hum.Hered_38_228
PubMedSearch : Whittaker_1988_Hum.Hered_38_228
PubMedID: 3169797

Title : Recognition of two new phenotypes segregating the E1k allele for plasma cholinesterase - Whittaker_1988_Hum.Hered_38_233
Author(s) : Whittaker M , Britten JJ
Ref : Hum Hered , 38 :233 , 1988
Abstract : The first identification of the cholinesterase variants E1kE1k and E1kE1s is reported from a family study. The evidence is based on the biochemical parameters of enzymic activity, and dibucaine, fluoride and RO2 numbers. Two individuals appear to be homozygotes E1kE1k and two are heterozygotes E1kE1s with family evidence supportive of these genotypes. The heterozygotes E1kE1s will be sensitive to suxamethonium.
ESTHER : Whittaker_1988_Hum.Hered_38_233
PubMedSearch : Whittaker_1988_Hum.Hered_38_233
PubMedID: 3169798

Title : Some observations of levels of plasma cholinesterase activity within an obstetric population - Whittaker_1988_Anaesthesia_43_42
Author(s) : Whittaker M , Crawford JS , Lewis M
Ref : Anaesthesia , 43 :42 , 1988
Abstract : An account of plasma cholinesterase activity in samples of maternal and cord blood is presented. It is confirmed that plasma exchange markedly reduces the level of activity in maternal blood, and that the level is further reduced during the first 3-4 postnatal days. A particularly marked decrease was found in those cases in which spontaneous mid-trimester abortion occurred. The level of activity in maternal blood (excluding mothers subjected to plasma exchange) at the time of delivery, was higher than that in cord blood in 61% of cases. In 23% of cases the level of activity was appreciably (0.05 units) higher in cord blood, and two-thirds of these cord samples contained the E2+ electrophoretic variant of plasma cholinesterase. The mean levels of activity in maternal and cord blood of Rhesus negative patients were significantly lower than those among Rhesus positive patients but there was no such distinction between Rhesus positive and Rhesus negative males and nonpregnant females. We encountered an incidence of 1:228 abnormal phenotypes in a series of 1593 mothers who underwent Caesarean section under a technique of general anaesthesia which included a suxamethonium infusion. However, probably only two of the seven patients would definitely be sensitive when not pregnant.
ESTHER : Whittaker_1988_Anaesthesia_43_42
PubMedSearch : Whittaker_1988_Anaesthesia_43_42
PubMedID: 3125760

Title : E1h, a new allele at cholinesterase locus 1 - Whittaker_1987_Hum.Hered_37_54
Author(s) : Whittaker M , Britten JJ
Ref : Hum Hered , 37 :54 , 1987
Abstract : Unusual inhibition characteristics in two unrelated suxamethonium-sensitive individuals were indicative of a new allele, E1h, segregating with the E1a gene. Family studies substantiate this hypothesis and three new genotypes are recognised.
ESTHER : Whittaker_1987_Hum.Hered_37_54
PubMedSearch : Whittaker_1987_Hum.Hered_37_54
PubMedID: 3557462

Title : Recognition of the E1kE1f cholinesterase genotype in a family segregating three rare genes, E1k, E1f and E1a - Whittaker_1987_Hum.Hered_37_82
Author(s) : Whittaker M , Taylor F , Battersby EF
Ref : Hum Hered , 37 :82 , 1987
Abstract : The first identification of the cholinesterase variant E1kE1f is reported from a family study. The evidence is based on the determination of enzymic activity, dibucaine, fluoride and RO2 numbers. Three individuals appear to have this genotype, and family evidence is not at variance with our conclusions. All three individuals will be sensitive to suxamethonium.
ESTHER : Whittaker_1987_Hum.Hered_37_82
PubMedSearch : Whittaker_1987_Hum.Hered_37_82
PubMedID: 3583292

Title : Phenotyping of individuals sensitive to suxamethonium. The Cholinesterase Research Unit at the Royal Postgraduate Medical School - Whittaker_1987_Br.J.Anaesth_59_1052
Author(s) : Whittaker M , Britten JJ
Ref : British Journal of Anaesthesia , 59 :1052 , 1987
Abstract : Four hundred and thirty blood samples from suxamethonium-sensitive individuals have been phenotyped by the Cholinesterase Research Unit following its transfer from Exeter to the Hammersmith Hospital. The distribution of genotypes has been shown to be similar to that found in Exeter. Screening for the Elk and Elj genes has not yielded any major differences in the gene frequencies of sensitive individuals, even during pregnancy. The uneven sex distribution of the patients, as well as other unusual points that have arisen, are discussed. A new gene for the biosynthesis of cholinesterase has probably been identified.
ESTHER : Whittaker_1987_Br.J.Anaesth_59_1052
PubMedSearch : Whittaker_1987_Br.J.Anaesth_59_1052
PubMedID: 3651274

Title : Analysis of suxamethonium sensitivity following termination of pregnancy - Whittaker_1987_Br.J.Anaesth_59_1157
Author(s) : Whittaker M , Britten JJ
Ref : British Journal of Anaesthesia , 59 :1157 , 1987
Abstract : The cholinesterase genotypes in the majority (25/35) of patients with suxamethonium sensitivity following termination of pregnancy are heterozygotes with an E1a gene. Twelve of these patients have the genotype E1uE1a. The reported duration of apnoea is minimal in the heterozygotes lacking the E1a gene (about 5-10 min) and maximal in the homozygotes E1aE1a (about 35 min). With few exceptions, the heterozygotes having an E1a gene are apnoeic for 10-15 min. The apparent low frequency of suxamethonium in these patients is discussed.
ESTHER : Whittaker_1987_Br.J.Anaesth_59_1157
PubMedSearch : Whittaker_1987_Br.J.Anaesth_59_1157
PubMedID: 3663436

Title : Plasma cholinesterase changes during the puerperium - Robson_1986_Anaesthesia_41_243
Author(s) : Robson N , Robertson I , Whittaker M
Ref : Anaesthesia , 41 :243 , 1986
Abstract : Changes in plasma cholinesterase activity during the puerperium were studied in 16 women who received epidural analgesia for labour followed by vaginal delivery and in five women who underwent elective Caesarean section under epidural analgesia A consistent fall in cholinesterase activity was demonstrated during the first 2 to 3 days post partum followed by a rise to approximately normal nonpregnant values by the end of the puerperium An additional patient who manifested prolonged paralysis following an emergency Caesarean section under general anaesthesia including a suxamethonium infusion was also studied Possible mechanisms by which the transient decrease in cholinesterase activity is produced and its clinical significance are discussed
ESTHER : Robson_1986_Anaesthesia_41_243
PubMedSearch : Robson_1986_Anaesthesia_41_243
PubMedID: 3963327

Title : Application of stepwise discriminant analysis in the phenotyping of plasma cholinesterase variants - Turner_1985_Ann.Clin.Biochem_22_175
Author(s) : Turner JM , Hall RA , Whittaker M , Holder RL , Kricka LJ
Ref : Annals of Clinical Biochemistry , 22 :175 , 1985
Abstract : Discriminant function analysis has been applied to the results of activity and inhibitor measurements carried out on a series of 229 specimens using benzoylcholine and butyrylthiocholine as substrate. The discriminant function was more effective in differentiating cholinesterase genotypes than either a single test or a combination of two tests.
ESTHER : Turner_1985_Ann.Clin.Biochem_22_175
PubMedSearch : Turner_1985_Ann.Clin.Biochem_22_175
PubMedID: 4004108

Title : Plasma cholinesterase variants. Family studies of the E1k gene - Whittaker_1985_Hum.Hered_35_364
Author(s) : Whittaker M , Britten JJ
Ref : Hum Hered , 35 :364 , 1985
Abstract : The use of RO2-0683 as differential inhibitor has shown that 13% of 181 heterozygotes, believed to be E1uE1a, are in fact E1aE1k. The results indicate that slightly more than 1% of the British population could be homozygote E1kE1k. Analysis of 47 families segregating the E1aE1k phenotype in more than 2 blood relatives is restricted by the inability to differentiate the genotypes E1uE1k and E1kE1k from E1uE1u and E1uE1f.
ESTHER : Whittaker_1985_Hum.Hered_35_364
PubMedSearch : Whittaker_1985_Hum.Hered_35_364
PubMedID: 4054903

Title : Effects of storage and repeated freezing and thawing on plasma cholinesterase activity - Turner_1984_Ann.Clin.Biochem_21_363
Author(s) : Turner JM , Hall RA , Whittaker M , Kricka LJ
Ref : Annals of Clinical Biochemistry , 21 :363 , 1984
Abstract : Plasma cholinesterase activity, determined using either benzoyl choline or butyrylthiocholine as substrate, is stable for prolonged periods (greater than 12 months) when stored at -20 degrees C. Likewise, repeated freezing and thawing of plasma did not markedly affect cholinesterase activity.
ESTHER : Turner_1984_Ann.Clin.Biochem_21_363
PubMedSearch : Turner_1984_Ann.Clin.Biochem_21_363
PubMedID: 6508207

Title : Comparison of a commercially available assay system with two reference methods for the determination of plasma cholinesterase variants - Whittaker_1983_Clin.Chem_29_1746
Author(s) : Whittaker M , Britten JJ , Dawson PJ
Ref : Clinical Chemistry , 29 :1746 , 1983
Abstract : For assaying plasma cholinesterase (EC 3.1.1.8) activity and phenotyping by means of dibucaine inhibition, we have compared a commercially available kit, in which butyrylthiocholine is used as substrate, with two reference methods, one using benzoylcholine and the other propionylthiocholine. With 50 different samples of three of the most common genetic variants, we could clearly differentiate the variants with benzoylcholine and dibucaine, whereas there was some overlap of the E1uE1u and E1uE1a phenotypes with the other two substrates at 30 degrees C. The phenotypes were better differentiated at 25 degrees C, and in our hands the use of butyrylthiocholine was preferable to propionylthiocholine for phenotyping with dibucaine. The affinity of the usual and atypical homozygotes for fluoride with butyrylthiocholine gave an inverted response to the affinity of these variants for the anion with benzoylcholine. We suggest that this may be explained by the role of the chromogen or its products in the assay procedure with the thiocholine substrate.
ESTHER : Whittaker_1983_Clin.Chem_29_1746
PubMedSearch : Whittaker_1983_Clin.Chem_29_1746
PubMedID: 6616819

Title : Postoperative ileus, pregnancy-related cholinesterase deficiency and suxamethonium after-pains. A case report - Whittaker_1983_Br.J.Anaesth_55_581
Author(s) : Whittaker M , Crawford JS
Ref : British Journal of Anaesthesia , 55 :581 , 1983
Abstract : An account is presented of a patient who developed ileus, of greater or lesser severity, after each of seven operations (including two extra-abdominal and three Caesarean sections). During her most recent pregnancy, reviewed here, her plasma cholinesterase activity was found to be decreased and it remained low until at least the 6th day post-partum. However, as the normal activity had been gained by 6 weeks after delivery, the phenomenon had evidently been pregnancy-related. Despite receiving suxamethonium by infusion to completion of her Caesarean section, she did not show an abnormally prolonged response, although she did suffer considerable suxamethonium "after-pains". The question is posed of a possible relationship between the postoperative ileus, muscle pains and the decrease in cholinesterase activity.
ESTHER : Whittaker_1983_Br.J.Anaesth_55_581
PubMedSearch : Whittaker_1983_Br.J.Anaesth_55_581
PubMedID: 6860526

Title : Suxamethonium apnoea associated with pregnancy and liver dysfunction in a treated cretin - Ferguson_1983_Anaesthesia_38_567
Author(s) : Ferguson A , Whittaker M , Britten JJ , Perriss BW
Ref : Anaesthesia , 38 :567 , 1983
Abstract : A patient, with a history of cretinism, who developed suxamethonium apnoea as a consequence of a reduction in plasma cholinesterase activity secondary to the concurrence of pregnancy and liver dysfunction associated with pre-eclampsia is reported. The patient had a normal phenotype for plasma cholinesterase.
ESTHER : Ferguson_1983_Anaesthesia_38_567
PubMedSearch : Ferguson_1983_Anaesthesia_38_567
PubMedID: 6869716

Title : Studies on the inhibition by propranolol of some human erythrocyte membrane enzymes and plasma cholinesterase - Whittaker_1982_Clin.Chim.Acta_119_107
Author(s) : Whittaker M , Wicks RJ , Britten JJ
Ref : Clinica Chimica Acta , 119 :107 , 1982
Abstract : Human erythrocyte acetylcholinesterase and the plasma cholinesterase variants are not only inhibited by propranolol but have been found to show stereospecificity for its isomers. The erythrocyte enzyme has a greater affinity for the L-isomer than either the racemate or the D-isomer. In contrast the plasma cholinesterases have greater specificity for the D-isomer than the other isomer or racemate. The usual enzyme shows greater stereospecificity than the atypical enzyme and these findings present additional evidence that these enzyme variants differ in structure at the catalytic active site. Neither Na+ + K+ -ATPase nor Mg2+-ATPase show stereo-specificity for the isomers of propranolol although both enzymes are inhibited by the drug. The action of the drug on the four enzymes in blood samples obtained from patients having Huntington's disease was found to be identical to those observed on the enzymes in blood samples from healthy controls.
ESTHER : Whittaker_1982_Clin.Chim.Acta_119_107
PubMedSearch : Whittaker_1982_Clin.Chim.Acta_119_107
PubMedID: 6120772

Title : Differential inhibition of plasma cholinesterase variants using the dibutyrate analogue of pancuronium bromide - Whittaker_1981_Hum.Hered_31_242
Author(s) : Whittaker M , Britten JJ
Ref : Hum Hered , 31 :242 , 1981
Abstract : A steroid, the dibutyrate analogue of pancuronium bromide (9.8 X 10(-8)M), has been used as differential inhibitor in the study of the plasma cholinesterase variants. Pancuronium dibutyrate numbers have been measured for 190 individuals, and the mean values for six of the known genotypes, E1uE1u, E1uE1f, E1uE1a, E1fE1a, E1aE1a, and E1fE1f, have been calculated. Evidence is presented that a combination of the pancuronium dibutyrate number and the fluoride number give better resolution of the six genotypes than the combination of the pancuronium dibutyrate and the dibucaine number. This new differential inhibitor has real potential for revealing the probable existence of new genotypes.
ESTHER : Whittaker_1981_Hum.Hered_31_242
PubMedSearch : Whittaker_1981_Hum.Hered_31_242
PubMedID: 7287015

Title : Malignant hyperthermia and the fluoride-resistant gene - Whittaker_1981_Br.J.Anaesth_53_241
Author(s) : Whittaker M , Britten JJ
Ref : British Journal of Anaesthesia , 53 :241 , 1981
Abstract : One hundred and six individuals from 33 families with a history of malignant hyperthermia have been investigated for plasma cholinesterase variants. An increased frequency of the fluoride-resistant gene has been found. Although an adequate explanation for our results is elusive, some hypotheses are discussed.
ESTHER : Whittaker_1981_Br.J.Anaesth_53_241
PubMedSearch : Whittaker_1981_Br.J.Anaesth_53_241
PubMedID: 7470359

Title : Inhibition of the plasma cholinesterase variants by propranolol - Whittaker_1981_Br.J.Anaesth_53_511
Author(s) : Whittaker M , Britten JJ , Wicks RJ
Ref : British Journal of Anaesthesia , 53 :511 , 1981
Abstract : The inhibitory effect of (+/-) propranolol 1.69 x 10(-4)-1.69 x 10(-7) mol litre-1 on normal and atypical plasma cholinesterase variants was investigated. The atypical enzyme is less sensitive to inhibition by (+/-) propranolol or either of its enantiomorphs than the usual enzyme. Propranolol 8.45 x 10(-6) mol litre-1 was used as differential inhibitor of 643 plasma samples from individuals of known genotype. Although the measurement of propranolol inhibition alone is not always unambiguous for assigning a definite genotype to a given individual, the correlation of propranolol inhibition with fluoride inhibition gives clear differentiation of the E1uE1u and E1UE1f phenotypes as well as other phenotypes.
ESTHER : Whittaker_1981_Br.J.Anaesth_53_511
PubMedSearch : Whittaker_1981_Br.J.Anaesth_53_511
PubMedID: 7236476

Title : The plasma cholinesteerases: a new perspective. -
Author(s) : Brown SS , Kalow W , Pilz W , Whittaker M , Woronick CL
Ref : Advances in Clinical Chemistry , 22 :1 , 1981
PubMedID: 7027759

Title : A comparison of some methods of phenotyping the plasma cholinesterase variants using benzoylcholine as substrate - Whittaker_1981_Ann.Clin.Biochem_18_9
Author(s) : Whittaker M , Britten JJ
Ref : Annals of Clinical Biochemistry , 18 :9 , 1981
Abstract : Five differential inhibitors of plasma cholinesterase have been compared using benzoylcholine as substrate. None of the inhibitors (dibucaine, NaF, NaBr, NaCl, or pancuronium dibutyryloxy bromide) could be used singly to resolve all the variants. Better resolution was obtained when two inhibitors were used in conjunction. Clear differentiation of all six genotypes was obtained only with the combined use of pancuronium dibutyryloxy bromide and sodium fluoride. The limitations of some of the parameters are discussed.
ESTHER : Whittaker_1981_Ann.Clin.Biochem_18_9
PubMedSearch : Whittaker_1981_Ann.Clin.Biochem_18_9
PubMedID: 7259066

Title : Suxamethonium-induced jaw stiffness and myalgia associated with atypical cholinesterase: case report - Melvoll_1980_Can.Anaesth.Soc.J_27_283
Author(s) : Melvoll R , Stovner J , Whittaker M
Ref : Canadian Anaesthetist's Society Journal , 27 :283 , 1980
Abstract : An 11-year-old boy was given halothane, nitrous oxide and oxygen, pancuronium 0.4 mg and suxamethonium 100 mg for induction of anaesthesia. In response to this a marked jaw stiffness occurred which lasted for two minutes and the anaesthesia were terminated. Four hours of apnoea ensued and he suffered generalized severe myalgia lasting for one week. He was found to have atypical plasma cholinesterase with a dibucaine number of 12, indicating homozygocity. This was verified by study of the family. The case shows that prolonged jaw rigidity and myalgia may occur after suxamethonium in patients with atypical cholinesterase despite pretreatment with pancuronium.
ESTHER : Melvoll_1980_Can.Anaesth.Soc.J_27_283
PubMedSearch : Melvoll_1980_Can.Anaesth.Soc.J_27_283
PubMedID: 7378868

Title : Inhibition of the plasma cholinesterase variants by pancuronium bromide and some of its analogues - Whittaker_1980_Clin.Chim.Acta_108_89
Author(s) : Whittaker M , Britten JJ
Ref : Clinica Chimica Acta , 108 :89 , 1980
Abstract : Pancuronium bromide, a 3,17-diacetoxy-5 alpha-androstane, and three of its analogues, the 17-desoxy, the 3,17-dibutyryloxy and the 16-N-monoquaternary ammonium derivatives have been used as inhibitors of the usual and atypical plasma cholinesterase variants. In all cases the usual enzyme is more sensitive to inhibition by the substituted steroids than the dibucaine resistant enzyme. The relative affinities of the bis-quaternary ammonium compounds for either enzyme is in the order dibutyryloxy derivative > 17-desoxy derivative greater than or equal to pancuronium bromide. The monoquaternary compound has the least affinity of all the inhibitors for the usual enzyme but the greater affinity for the atypical enzyme. These observations show that the bis-quaternary compounds are very powerful differentiators of the variants. The monoquaternary derivative shows less differential inhibition, but provides additional evidence that the usual and dibucaine resistant variants differ in structure at or near their esteratic active site.
ESTHER : Whittaker_1980_Clin.Chim.Acta_108_89
PubMedSearch : Whittaker_1980_Clin.Chim.Acta_108_89
PubMedID: 6108807

Title : Plasma cholinesterase variants and the anaesthetist - Whittaker_1980_Anaesthesia_35_174
Author(s) : Whittaker M
Ref : Anaesthesia , 35 :174 , 1980
Abstract : Biochemical properties of plasma cholinesterase of significance to the anaesthetist are reviewed. The role of the genetic variants of the enzyme in suxamethonium sensitivity and hyperthermia are discussed with emphasis on the pregnant patient. Altered gene frequencies of the enzyme variants in some mental disorders is commented upon.
ESTHER : Whittaker_1980_Anaesthesia_35_174
PubMedSearch : Whittaker_1980_Anaesthesia_35_174
PubMedID: 6992635

Title : Plasma cholinesterase polymorphism in Down's syndrome - Whittaker_1977_Hum.Hered_27_52
Author(s) : Whittaker M , Berry M
Ref : Hum Hered , 27 :52 , 1977
Abstract : The plasma cholinesterase variants in 80 patients having Down's syndrome have been examined and compared with a random control sample of individuals domiciled in the same area. Neither a change in frequency of known C5+ variant nor any new variant has been found in the electrophoretic studies. A highly significant increase in frequency of the fluoride resistant gene as well as a significant decrease in frequency of the atypical gene has been found in the Down's syndrome individuals. This altered distribution of the rare phenotype of plasma cholinesterase in mental illness may lead to a useful diagnostic acid in genetic counselling.
ESTHER : Whittaker_1977_Hum.Hered_27_52
PubMedSearch : Whittaker_1977_Hum.Hered_27_52
PubMedID: 139357

Title : The plasma cholinesterase variants in mentally ill patients - Whittaker_1977_Br.J.Psychiatry_130_397
Author(s) : Whittaker M , Berry M
Ref : British Journal of Psychiatry , 130 :397 , 1977
Abstract : The distribution of the plasma cholinesterase variants found in 1,374 mentally ill patients differs from that of a random control sample. The patients are more likely to have a rare phenotype than an individual from the normal population. None of the diagnostic groups have been shown to differ in the distribution of the E1a gene, but there is strong statistical evidence that Group IV (psychosis) patients have a higher frequency of the E1f gene than the other groups. The overall frequency of the electrophoretic variant C5 + did not differ significantly from that observed in a Caucasian population, with the exception of the increase observed in Group IV c2. Twenty-eight unrelated patients with Huntington's chorea were found to have a significantly altered incidence of the C5 + variant and six patients from this group were found to have the rare E1f gene. Our results indicate that the plasma cholinesterase variants may provide some insight into the inheritance of Huntington's chorea.
ESTHER : Whittaker_1977_Br.J.Psychiatry_130_397
PubMedSearch : Whittaker_1977_Br.J.Psychiatry_130_397
PubMedID: 139958

Title : Plasma cholinesterase variants in patients having lithium therapy - Whittaker_1977_Clin.Chim.Acta_75_421
Author(s) : Whittaker M , Spencer R
Ref : Clinica Chimica Acta , 75 :421 , 1977
Abstract : The plasma cholinesterase variants of 190 mentally ill individuals having lithium prophylaxis have been examined. A significantly increased frequency of the E1f gene is reported. The effect of lithium nitrate and sodium nitrate on the plasma cholinesterase variants have been shown to be identical in the concentration range 25.0-50.0 mmol/l. The usual enzyme is slightly less sensitive to inhibition by either salt than the dibucaine resistant variant. The evidence suggest that the increased frequency of the E1f gene could be a genetic marker associated with some mental illness and not the result of lithium prophylaxis.
ESTHER : Whittaker_1977_Clin.Chim.Acta_75_421
PubMedSearch : Whittaker_1977_Clin.Chim.Acta_75_421
PubMedID: 852131

Title : Plasma cholinesterase and malignant hyperthermia [letter] -
Author(s) : Whittaker M , Spencer R , Searle J
Ref : British Journal of Anaesthesia , 49 :393 , 1977
PubMedID: 889656

Title : Serum cholinesterase variants in African leprosy patients resident in Rhodesia - Whittaker_1976_Hum.Hered_26_372
Author(s) : Whittaker M , Lowe RF , Ellis BP
Ref : Hum Hered , 26 :372 , 1976
Abstract : Blood samples from 580 African leprosy patients living in Rhodesia have been phenotyped for the plasma cholinesterase variants. The Africans have been grouped according to country of origin and tribal affiliation. We have found no individual with an Ea1 gene and are unable to resolve the contradictory evidence for an association between this gene and leprosy. The frequency of the Ef1 gene is higher than that usually found in Caucasian populations, being 0.046 in lepromatous leprosy patients and similar to the 0.056 found in healthy African controls. In tuberculoid leprosy patients the frequency is, however, significantly lower at 0.019. On the other hand, the frequency of the C5+ variant is essentially the same for the tuberculoid leprosy patients and the healthy controls (4%) while for the lepromatous leprosy patients it is about 7% approaching the 10-15% found in many Caucasian populations.
ESTHER : Whittaker_1976_Hum.Hered_26_372
PubMedSearch : Whittaker_1976_Hum.Hered_26_372
PubMedID: 992665

Title : The cholinesterase variants found in some African tribes living in Rhodesia - Whittaker_1976_Hum.Hered_26_380
Author(s) : Whittaker M , Lowe RF
Ref : Hum Hered , 26 :380 , 1976
Abstract : Blood samples from 1,614 Africans living in Rhodesia have been phenotyped for the cholinesterase variants at the E1 and E2 loci. 24% of the African population were non-Rhodesian by birth. 1,227 Rhodesians aligned themselves to 20 tribes, 191 Malawians to 8 tribes. 162 Mozambique Africans to 9 tribes and 34 Zambians to 8 tribes. A high frequency of 0.036 for the Ef1 gene, which varies from tribe to tribe, has been found in Rhodesian and Malawian Africans. Similar high frequencies for this gene are recorded for Zambian (0.045) and Mozambique Africans (0.034). The frequencies of the Es1 gene in these groups are 0.013 (Rhodesian), 0.009 (Malawian), and 0.016 (Mozambique African). The small Zambian sample showed evidence for neither the Es1 nor the C5+ electrophoretic variant. The absence of the Ea1 gene in the 1,613 Africans provides additional evidence of the rarity of this gene in negroid populations. The frequency of the C5+ variant in Rhodesian, Malawian and Mozambique Africans, although varying from tribe to tribe within the range of 0-8%, averages 3% in each group. These represent low frequencies for this variant when compared to other populations. No rare or 'private' electrophoretic variant has been found.
ESTHER : Whittaker_1976_Hum.Hered_26_380
PubMedSearch : Whittaker_1976_Hum.Hered_26_380
PubMedID: 992666

Title : Plasma cholinesterase studies on south-eastern Bantu of Mozambique - Whittaker_1975_Hum.Hered_25_296
Author(s) : Whittaker M , Reys L
Ref : Hum Hered , 25 :296 , 1975
Abstract : Blood samples from four Bantu tribes in South-East Mozambique have been phenotyped for the plasma cholinesterase variants of the E1 locus. A control roup of 153 Portuguese residents in Mozambique have also been phenotyped. The frequencies of both the E1a and E1f genes in the Portuguese population is very similar to those in other Caucasian populations. The absence of the E1a gene in the four Bantu tribes provides more evidence of the rarity of this gene in Negroid populations. There is an increased frequency of E1f gene in all tribes as compared with previous surveys. The Ronga and Bitonga tribes have similar E1f frequencies of 0.047 and 0.048, respectively. The Shangana has an E1f frequency of 0.060, and the corresponding figure for the Chopi tribe is 0.089. The latter is the highest recorded frequency for this gene. The results give some support to the doubts concerning the affiliation of the Chopi tribe.
ESTHER : Whittaker_1975_Hum.Hered_25_296
PubMedSearch : Whittaker_1975_Hum.Hered_25_296
PubMedID: 1184015

Title : Incidence of suxamethonium apnoea in patients undergoing E.C.T - Berry_1975_Br.J.Anaesth_47_1195
Author(s) : Berry M , Whittaker M
Ref : British Journal of Anaesthesia , 47 :1195 , 1975
Abstract : Plasma cholinesterase variants have been examined in blood samples obtained from 23 patients who, after an intravenous injection of suxamethonium 30 mg before e.c.t., had prolonged apnoea. Attempts have been made to screen the relatives of all patients shown to have an unusual plasma cholinesterase. The present study indicates an increased frequency of the fluoride-resistant variants in those psychiatric patients sensitive to suxamethonium.
ESTHER : Berry_1975_Br.J.Anaesth_47_1195
PubMedSearch : Berry_1975_Br.J.Anaesth_47_1195
PubMedID: 1218148

Title : The pseudocholinesterase variants. A family segregating for two homozygotes with the fluoride resistant gene -
Author(s) : Whittaker M , Berry M
Ref : Hum Hered , 22 :243 , 1972
PubMedID: 4562379

Title : The effect of phospholipase A on human erythrocyte acetylcholinesterase -
Author(s) : Whittaker M , Charlier AR
Ref : FEBS Letters , 22 :283 , 1972
PubMedID: 11946618

Title : Some characteristics of acetylcholinesterase extracted from human erythrocytes by three different detergents -
Author(s) : Jackson P , Whittaker M
Ref : Enzymologia , 43 :359 , 1972
PubMedID: 4646286

Title : Evidence for an abnormality in the erythrocyte membranes of patients having paroxysmal nocturnal haemoglobinuria and aplastic anemia -
Author(s) : Jackson P , Whittaker M
Ref : Clinica Chimica Acta , 41 :299 , 1972
PubMedID: 4645237

Title : The effects of lipases and proteases on usual and atypical serum cholinesterase -
Author(s) : Whittaker M , Charlier AR
Ref : Enzymologia , 42 :423 , 1972
PubMedID: 5038365

Title : Neuromuscular actions of lignocaine and prilocaine -
Author(s) : Laity JL , Whittaker M
Ref : British Journal of Pharmacology , 43 :431P , 1971
PubMedID: 4258170

Title : Changes in plasma cholinesterase isoenzymes due to oral contraceptives -
Author(s) : Whittaker M , Charlier AR , Ramaswamy S
Ref : J Reprod Fertil , 26 :373 , 1971
PubMedID: 5569652

Title : The effect in vitro of thyroxine, glucagon, thyrotrophin and antithyroid drugs on 'usual' and 'atypical' human plasma cholinesterase -
Author(s) : Whittaker M
Ref : J Endocrinol , 47 :177 , 1970
PubMedID: 4194092

Title : Initial experiences with the Cholinesterase Research Unit -
Author(s) : Whittaker M , Vickers MD
Ref : British Journal of Anaesthesia , 42 :1016 , 1970
PubMedID: 5488351

Title : Genetic aspects of succinylcholine sensitivity -
Author(s) : Whittaker M
Ref : Anesthesiology , 32 :143 , 1970
PubMedID: 4905600

Title : The serum cholinesterase variants. Differentiation by means of formaldehyde -
Author(s) : Whittaker M
Ref : Clinica Chimica Acta , 26 :141 , 1969
PubMedID: 5356589

Title : Properties of usual and atypical serum cholinesterases using o- nitrophenyl butyrate as substrate -
Author(s) : Whittaker M , Hardisty CA
Ref : Clinical Chemistry , 15 :445 , 1969
PubMedID: 5786800

Title : The frequency of the fluoride resistant gene in a population of British students -
Author(s) : Whittaker M
Ref : Acta Genet Stat Med , 18 :563 , 1968
PubMedID: 5756527

Title : Echothiophate iodide treatment of glaucoma in pregnancy -
Author(s) : Birks DA , Prior VJ , Silk E , Whittaker M
Ref : Archives of Ophthalmology , 79 :283 , 1968
PubMedID: 5640850

Title : Suxamethonium apnoea -
Author(s) : Whittaker M , Vickers MD
Ref : British Journal of Anaesthesia , 40 :393 , 1968
PubMedID: 5655458

Title : The pseudocholinesterase variants. Differentiation by means of sodium chloride -
Author(s) : Whittaker M
Ref : Acta Genet Stat Med , 18 :556 , 1968
PubMedID: 5756526

Title : Frequency of atypical pseudocholinesterase in groups of individuals of different ethnographical origin -
Author(s) : Whittaker M
Ref : Acta Genet Stat Med , 18 :567 , 1968
PubMedID: 5756528

Title : The pseudocholinesterase variants. Differentiation by means of alkyl alcohols -
Author(s) : Whittaker M
Ref : Acta Genet , 18 :325 , 1968
PubMedID:

Title : Differential inhibition of human serum cholinesterase with n-butyl alcohol: recognition of new phenotypes -
Author(s) : Whittaker M
Ref : Acta Genet , 18 :335 , 1968
PubMedID:

Title : An additional pseudocholinesterase phenotype occurring in suxamethonium apnoea -
Author(s) : Whittaker M
Ref : British Journal of Anaesthesia , 40 :579 , 1968
PubMedID: 5667302

Title : Suxamethonium apnoea -
Author(s) : Whittaker M , Vickers MD
Ref : British Medical Journal , 4 :254 , 1968
PubMedID: 5682332

Title : The pseudocholinesterase variants. A study of fourteen families selected via the fluoride resistant phenotype -
Author(s) : Whittaker M
Ref : Acta Genet , 17 :1 , 1967
PubMedID:

Title : A study of the pseudocholinesterase in 78 cases of apnoea following suxamethonium -
Author(s) : Thompson JC , Whittaker M
Ref : Acta Genet , 16 :209 , 1966
PubMedID:

Title : A study of the pseudocholinesterase in 78 cases of apnoea following suxamethonium -
Author(s) : Thompson JC , Whittaker M
Ref : Acta Genet Stat Med , 16 :209 , 1966
PubMedID: 5953708

Title : Pseudocholinesterase activity in thyroid disease -
Author(s) : Thompson JC , Whittaker M
Ref : Journal of Clinical Pathology , 18 :811 , 1965
PubMedID: 5844216

Title : Genetical studies on a new variant of serum cholinesterase detected by electrophoresis -
Author(s) : Harris H , Hopkinson DA , Robson EB , Whittaker M
Ref : Annals of Human Genetics , 26 :359 , 1963
PubMedID: 13952923

Title : Differential inhibition of usual and atypical serum cholinesterase by NACI and NaF -
Author(s) : Harris H , Whittaker M
Ref : Annals of Human Genetics , 17 :53 , 1963
PubMedID:

Title : Differential inhibition of the serum cholinesterase phenotypes by solanine and solanidine -
Author(s) : Harris H , Whittaker M
Ref : Annals of Human Genetics , 26 :73 , 1962
PubMedID: 13904837

Title : The serum cholinesterase variants. A study of twenty-two families selected via the intermediate phenotype -
Author(s) : Harris H , Whittaker M
Ref : Annals of Human Genetics , 26 :59 , 1962
PubMedID: 13904838

Title : Differential inhibition of serum cholinesterase with fluoride. Recognition of two new phenotypes -
Author(s) : Harris H , Whittaker M
Ref : Nature , 191 :496 , 1961
PubMedID: 13711731

Title : The pseudocholinesterase variants. Esterase levels and dibucaine numbers in families selected through suxamethonium sensitive individuels -
Author(s) : Harris H , Whittaker M , Lehmann H , Silk E
Ref : Acta Genet Stat Med , 10 :1 , 1960
PubMedID:

Title : Differential response of human serum cholinesterase types to an inhibitor in potato -
Author(s) : Harris H , Whittaker M
Ref : Nature , 183 :1808 , 1959
PubMedID: 14399950