Increase cholinesterase activity in psychiatric patients treated with fluphenazine, lithium and amitryptyline - Abstract

This study was planned to determine the effects of antipsychotic and antidepressant drug therapy on serum cholinesterase in an out-patient sample population in Trinidad. Inhibition of cholinesterase by dibucaine (dibucaine number) and esterase activity were measured. Mean dibucaine number (81.9 ñ 2.37) in psychiatric patients was not different from the normal population (81.9 ñ 2.55). Quantitative esterase levels were significantly higher (12.37 ñ 3.57 U/ml; p<0.05) in comparison to the normal Trinidadian population (10.05 ñ 2.67 U/mL). Cholinesterase levels were significantly higher (p<0.05) in female schizophrenics than in depressed patients. A relationship between elevated enzyme activity and pathology of the disease or drug therapy could not be determined since most patients were on long term pharmacotherapy. The evaluation of cholinesterase activities in out patients indicates that drugs such as fluphenazine, lithium carbonate and amitriptyline may be associated with increase enzyme activity.(AU)

A 'silent' cholinesterase gene detected by western blotting

A 38 year old Asian Indian female with a history of prolonged succinylcholine-induced apnoea was shown to have negligible levels of serum cholinesterase as determined by the dibucaine number test and quantitative enzyme estimation by the modified Ellman method. Electrophoresis of the patients's serum on a 5-20 percent gradient gel stained with Fast Red TR and O-naphthyl acetate detected no cholinesterase inesterase gene in this individual. A family study was initiated to include 19 other members; a similar pattern of cholinesterase activity could be demonstrated in a sister of proband. Western blotting was performed on the sera of the two sisters and selected family members. The cholinesterase antigenic banding pattern of the sisters' sera expressing the 'silent' gene was similar to controls, with additional bands. The cholinesterase gene segregating in this family correspond to the Type II 'silent' gene was similar to controls, with additional bands. The cholinesterse gene segregating in this family correspond to the Type II 'silent' gene variant which has about 3 percent of usual enzyme activity (AU)

Atypical cholinesterase gene Ea: rarity in the Jamaican population - abstract

This paper reports on the rarity of the atypical cholinesterase gene Ea in the Jamaican population, via experimentally observed specific activities and percentage inhibition by dibucaine.. Homozygotes for the abnormal enzyme may develop prolonged apnoea when the muscle relaxant suxamethonium is administered prior to surgery. A total of 499 subjects were studied; of these 240 had normal serum cholinesterase activity (2669 ñ 514 mU/ml of serum) and normal dibucaine number 88. The remaining 259 subjects had lower than normal activity (1422 ñ 259 mU/ml) but normal dibucaine number 87. Homozygous carriage of the atypical gene is associated with dibucaine numbers below 20. Based upon these findings, the ensuing apnoea often caused by the abnormal enzyme (Ea) is therefore expected to be very rare among Jamaicans: 25 percent of our 17 subjects who underwent suxamenthonium administration had low cholinesterase activity (1479 ñ 210 mU/ml) but had normal dibucaine number 89 and suffered prolonged apnoea, lasting from 30 to 78 minutes. These preliminary results suggest that the determination of cholinesterase activity and dibucaine numbers may not always be the most reliable criteria to differentiate the suxamenthonium-sensitive and -insensitive subjects (AU)

Slient cholinesterase gene in an East Indian family in Trinidad - abstract

During a study to determine the frequency distribution of the enzyme pseudocholinesterase (Cholinesterase) in the population of Trinidad, an East Indian individual developed prolonged respiratory apnoea on administration of a routine dose of suxamethonium. This paper reports the results of analyses of the frequency distribution of pseudocholinesterase in the sera from the index case and 19 family members. Cholinesterase was detected qualitatively in the serum, using the Dibucaine Number (DN) and Fluoride Number (FN) tests (normal values: 78.8 per cent and 61.4 per cent, respectively), and quantitatively, using the modified Ellman method (normal plasma levels: 8:44 ñ 1.78 u/ml). Patients with low activity of the enzyme (inhibited < 20 per cent by dibucaine) are "suxamethonium-sensitive". DN and FN values in the serum of the index case could not be determined because of the negligible enzyme activity (0.17 u/ml). Of the 6 of 7 siblings available for testing, 1 was found with undeterminable DN and FN values and even lower enzyme activity (0.09 u/ml). The proband's marital partner, 2 children and father had normal enzyme patterns. This condition of `trace' enzyme activity is controlled by a `silent gene' (AU)

A study of the use and impact of pesticides in St. Lucia - abstract

This paper presents the results of a survey of 130 pesticide users designed to identify attitudes, gaps in knowledge, and unsafe practices which contribute to the risk of pesticide usage to health. A tintometric field method was compared to a standard laboratory method to detect cases of cholinesterase inhibition (pesticide poisoning). Sixty-five per cent of the agricultural workers and vector control officers never wear protective clothing. Their knowledge of routes of absorption was inadequate, but even if warnings are printed boldly on the product labels, <50 percent of the users were capable of consistently understanding written warnings. However, <60 percent of the individuals who understood the labels generally followed the advice provided. The 53 percent of respondents who had received training were no more likely than their untrained colleagues to adhere to safety practices. No significant differences existed between the cholinesterease levels of the exposed and the unexposed workers, but this may be the result of several conservative biases (AU)

Serum cholinesterase levels of vector control workers in Trinidad, West Indies (1979-1987)

During 1979-1987 studies were carried out in vitro on the serum cholinesterase levels of 46 vector control workers exposed to insecticides on a daily basis but without clinical manifestations of insecticide poisoning. The results were compared with those of a control group of workers who had not been exposed to insecticides at home or at work. Cholinesterase levels of both groups were determined by a standard colorimetric method. Suppressed serum cholinesterase levels were detected in all 46 workers exposed to insecticides, 25 of whom were aged 30-39 years. Four persons from the control group showed suppressed levels of enzyme; one of these had a genetically low level, and the other three were on medication when the low levels were recorded. (AU)

Serum cholinesterase levels of vector control workers in Trinidad, West Indies (1979-1982)

During the period 1979-1982, serum cholinesterase levels were determined in blood samples collected from workers employed at the Insect Vector Control Division, Trinidad, W.I. A total of 1,162 blood samples were collected, of which 116 showed suppressed cholinesterase levels. Those workers with low serum cholinesterase levels included 46 residual spraymen, 66 Aedes aegypti operators and 4 controls. The difference in numbers of spraymen and Aedes operators with low cholinesterase levels was significant (p<.001). No significant differences were found in the number of Aedes operators with low cholinesterase levels from North and South Trinidad. Similarly, no differences were found in the number of residual spraymen from North and South Trinidad with low cholinesterase levels. A total of 7 Aedes operators and 4 residual spraymen had persistently low serum cholinesterase levels. It is likely that the main areas of absorption were the hands and forearms, with further absorption occurring via respiration. The need for continuous monitoring and supervision of vector control workers who handle insecticides is stressed (AU)

Ultrastructural and neuropharmacological findings in the nerve/muscle system of a digenean (Cercaria caribbea LXXI Cable)

The surface morphology and organization of the neuromuscular system in Cercaria caribbea LXXI are investigated using scanning and transmission electron microscopy, respectively. Direct and indirect (sarconeural) nerve-muscle junctions are identified in the cercarial tail. Synaptic vesicles at the direct neuromuscular junction suggest cholinergic and aminoacidergic transmission. Those at the sarconeural junctions suggest catecholaminergic and/or serotonergic transmission. Acetylcholinesterase and non-specific cholinesterases were found in high concentrations in the proximal and distal tail. Flourescence histochemistry showed primary catecholamines and 5-HT in the body and tail. 5-HT in the tail may represent a slowly depleted store, perhaps associated with energy availability and utilization. (AU)

Malathion poisoning: A report of 2 cases

Two cases of malathion poisoning are described. Serum chlinesterase levels for the duration of their stay in the Intensive Care Unit were followed. Supportive ventilation in these patients could be discontinued before normal levels of cholinesterase activity in the serum were reached. Although the levels of serum cholinesterase activity rose steadily as the patients improved, clinical assessment provided a more important prognostic index than the actual cholinesterase values (AU)

Observations on enzymes in the human liver: general considerations and preliminary results

It has long been supposed that malnutrition predisposes the liver to injury. An attempt has been made to characterize this vulnerable state in biochemical terms. A diet deficient in protein causes the liver cell to lose a large proportion of its cytoplasmic protein and ribonucleic acid. It is suggested that this might lead to a disturbance in the amount or pattern of enzymes, which could have serious metabolic consequences. To test this hypothesis, measurements were first made of a number of single-enzyme systems, e.g. dehydrogenases transaminase choline esterase, cytochrome oxidase, cytochromec reductase. Only choline esterase was reduced in activity in the malnourished liver; the other enzymes were well preserved. Preliminary evidence suggests that more complex systems,involving a chain of enzymes, may be more easily damaged. (AU)

Observations on the activity of some enzymes in the human liver

Preliminary measurements have been made of the activity of some enzymes in the human liver in relation to nutritional state. Liver tissue was obtained by aspiration biopsy. The subjects were infants with moderate or severe malnutrition. Of the enzymes studied the most active were cytochrome oxidase, lactic dehydrogenase, and non-specific or pseudo-choline esterase. In the malnourished subjects there was a reduction in concentration of non-specific esterase in both liver and plasma. Normal levels were restored after feeding on a high protein diet. The significance of this finding is briefly discussed. (AU)