[Clinical, electroencephalographic and biochemical aspects of the 1-dopa effect].
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Blood Glucose↗
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Results for “MANDELIC ACID”
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Pharmacokinetic studies of mabuterol, a new selective beta 2-stimulant. II: Urinary metabolites of mabuterol in rats and their pharmacological effects.
A selective beta 2-stimulating bronchodilator, dl-1- (4-amino-3-chloro-5-trifluoromethyl-phenyl)-2-tert.-butyl-amino-ethanol hydrochloride (mabuterol), is mainly metabolized by oxidative deamination pathway. Unchanged mabuterol and the following 6 types of metabolites, M-1 (hydroxylation of tert.-butyl group), M-2 (glycol), M-3 (mandelic acid), M-4 (aldehyde), M-5 (benzoic acid) and M-6 (hippuric acid) were identified by thin-layer chromatography and mass spectroscopy. Pharmacologically, only M-1 had effects on the airway resistance, blood pressure and heart rate, and the isolated organs. But its selective beta 2-stimulating effect was 2-10 times lower than that of mabuterol. M-1 antagonized the positive inotropic action induced by isoprenaline (isoproterenol). Other metabolites showed no appreciable activity.
Adrenergic beta-Agonists↗
[Catecholamines and their derivatives in the study of pheochromocytoma].
The biochemical diagnosis of pheochromocytoma is essentially based on the plasma and urinary levels of catecholamines and their derivatives, the metanephrines and vanyl-mandelic acid. The advantages and disadvantages of these investigations are reviewed, especially as regards the specificity and sensitivity of each test. The measurement of urinary metanephrine is the best test as its excretion is relatively higher, and it is rarely normal. The measurement of plasma catecholamines is more difficult but gives satisfactory results, but experience so far is limited.
Adrenal Gland Neoplasms↗
[Interrelationship between the activity of cholinergic processes and catecholamine metabolism in botulin poisoning].
Reversible inhibition of cholinergic processes in cats after pancreatectomy was accompanied by decreased urinary excretion of adrenaline, increased excretion of vanilyl mandelic acid, exhaustion of catecholamine stores in adrenal glands and increased content of noradrenaline in some tissues. Similar alterations occurred in the paralytic step of botulinic intoxication. Metabolism of catecholamines was much more distinctly impaired in previously pancreatectomized animals after development of botulinic and tetanic neurointoxications, which were accompanied by irreversible inhibition of acetylcholine liberation in myoneural synapses. Impairments of catecholamine metabolism were manifested in a decrease in total content of the substances studied in various tissues.
Acetylcholine↗
[Effect of the activity of adrenergic processes on tissue catecholamine concentrations].
Demedullation of adrenal glands caused a decrease in excretion of adrenaline and vanilyl mandelic acid with simultaneous increase of adrenaline content in various rat tissues. Predemedullation of adrenal glands prevented distinctly the alterations in catecholamine metabolism, which developed in botulinic and tetanic neurointoxications. The data obtained suggest that activation of adrenergic processes is of importance in genesis of the alterations observed in catecholamine metabolism under conditions of botulinic and tetanic intoxications.
Adrenal Medulla↗
[Pheochromocytoma].
We present a series of 11 patients with pheochromozytomas. We recommend screening for a catecholamine-producing tumor for every patient with hypertension. Screening and diagnosis are based on demonstration of an increased catecholamine production or -excretion. In our laboratory determination of urinary vanillin-mandelic-acid proved to be quite accurate. As 6 of our 11 pheochromozytomas were found extra-adrenally preoperative evaluation with regard to localization of these tumors appears as sound practice. According to our experience no single examination can be favoured. Therefore localization of these tumors is best accomplished by multiple diagnostic procedures. Morbidity and mortality depend directly upon preoperative recognition of a catecholamine-producing tumor and thus according management. We were able to gather data on 8 of 10 surviving patients 4--13 years postoperatively. Six of these are normotensive without any treatment.
Adolescent↗
Personality and long term exposure to organic solvents.
Personality, especially emotional reactions of two solvent exposed groups and a nonexposed reference group were described by means of 20 formal, content and check-list type of Rorschach variables. Another objective of the study was to explore the suitability and psychological meaning of other types of Rorschach variables than those applied earlier in the field of behavioral toxicology. The factor analyses grouped the applied variables into factors of Productivity, Ego Strength, Control of Emotionality, Defensive Introversion and Aggressiveness. One solvent group, a patient groups (N=53), was characterized by a high number of Organic signs and a low Genetic Level, indicating possible psychoorganic deterioration. The other solvent group, styrene exposed but subjectively healthy (N=98), was characterized by few emotional reactions, low Anxiety and a low number of Neurotic Signs. the long duration of exposure of the solvent patient group (mean 10.2 +/- 8.7 years) was related to variables of the Productivity factor, a finding that indicates a possible better adjustment of those exposed for a longer time. The duration of exposure of the styrene exposed group (mean 4.9 +/- 3.2 years) revealed a very slight relation to personality variables, but the mean urinary mandelic acid concentration, indicating the level of styrene exposure, correlated with increased emotional reactions. For the most part definite causal conclusions could not be drawn because of the cross-sectional design of the study.
Adult↗
Death from phaeochromocytoma: lessons from a post-mortem survey.
Despite advances in biochemical assessment and imaging, phaeochromocytoma remains a difficult diagnosis. Using the names of patients whose death certificate listed phaeochromocytoma as a cause of death, a retrospective survey of 62 deaths from phaeochromocytoma (48 benign, 14 malignant) was carried out. All deaths occurred between 1981 and 1989, so the pitfalls uncovered reflect recent practice. A substantial proportion presented with abdominal pain and vomiting, dyspnoea, left ventricular failure or hypotension rather than the classical symptoms. These presentations were more common in this autopsy series than in prospective series of consecutive patients. Diagnosis in the presence of classical symptoms was often delayed but, once it was made, elective excision was relatively safe. A personal or family history of symptoms suggesting inherited diseases associated with phaeochromocytoma was not always given due weight. Biochemical tests, particularly 24 hour urinary vanillyl mandelic acid, often gave contradictory results; the limits of their predictive power should be better appreciated. Anaesthesia and surgery in the presence of undiagnosed phaeochromocytoma was the cause of death in 16 of 62 cases. Recommendations to improve the accuracy of diagnosis are made.
Adolescent↗
Diencephalic epilepsy resembling pheochromocytoma: a first reported case in Thailand.
A 31 year old hypertensive patient suffered from a fluctuation of blood pressure. Pheochromocytoma was suspected because of the clinical history, and extremely labile blood pressure but did not respond to therapy with alpha adrenergic blocking agent and normal excretion rates of catecholamine and vanilly mandelic acid (VMA). An enlarged left adrenal gland from computerized tomographic scan was found. So left adrenalectomy was performed and the result was consistent with cortical adrenal hyperplasia. Fluctuation of blood pressure still occurred after surgery with the symptoms of epigastric oppression and focal epileptic attack of the left arm. Epileptic potential waves were seen during hyperventilation from electroencephalogram but showed normal magnetic resonance imaging computerized tomographic scan of the brain. Diencephalic epilepsy was diagnosed and treated with anticonvulsant (carbamazepine) and eventually all of the symptoms including labile blood pressure subsided.
Adrenal Gland Neoplasms↗
Studies of amine metabolites in affective illness and in schizophrenia: a comparative analysis.
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3,4-Dihydroxyphenylacetic Acid↗
Multiple endocrine neoplasia type IIb: a case report.
We reported a 14-year-old boy who had had multiple thyroid nodules for 4 yrs. Physical examination revealed marfanoid habitus, coarse facies with thick lips and prominent jaw. Mucosal neuromas were present on the buccal mucosa, tongue and upper eyelids. Thyroid scan demonstrated multiple, cold nodules and medullary thyroid carcinoma was confirmed by pathological examination. He was normotensive and his 24 hrs urinary vanillyl mandelic acid was in the normal range. Computerized tomography demonstrated normal adrenal glands. Multiple endocrine neoplasia type IIb (MEN IIb) was diagnosed by the appearance of typical phenotypic features, multiple mucosal neuromas and medullary thyroid carcinoma. The scarcity of such reports in children and the importance of early recognition of this disorder prompted us to describe this patient.
Adolescent↗
A trial to discriminate spontaneous regression from non-regression cases during mass screening for neuroblastoma.
We tried to discriminate between cases of spontaneous regression and non-regression during mass screening for neuroblastoma, taking advantage of differences in respect to the urinary homoranillic acid/vanillyl mandelic acid (HVA/VMA) ratio and the original tumor site among true positive, false negative and natural occurrence cases. After classifying them into a total of six groups depending on the two factors, ratio: < 1, 1-2 or > or = 2 and tumor site: adrenal or extra-adrenal in origin, we calculated the mathematical probability of a given true positive case being one of spontaneous regression. A tumor of extra-adrenal origin was likely to regress spontaneously, especially one with an HVA/VMA ratio < 1 or > or = 2 (82.2-100%). A tumor of adrenal origin with an HVA/VMA ratio < 1 seemed unlikely to regress spontaneously (0-4%). The present method, employing simple preoperative information, would be useful in future for the selection of true positive cases which should be observed without treatment.
Adrenal Gland Neoplasms↗
[Evidence of a pharmacokinetic-pharmacodynamic relationship between pharmaco-EEG in healthy subjects after administration of cyclandelate].
In an open randomized cross-over study 800 mg cyclandelate (Natil, CAS 456-59-7) was applicated to 24 young, male volunteers. Before and during 24 h after application of a single dose a 17-channel, quantitative topographical pharmaco-EEG was recorded. A significant increase of the spectral power density was observed in the alpha 2, beta 1 and beta 2 frequency bands starting 2 h after application until 4.5 h. The increase in beta 1 and beta 2 power was observed in the parietocentral area of the cortex. The difference between the circadian development of the EEG power and the development after medication was obvious after 3 until 4.5 h. For the beta frequencies only a weak statistical confirmation could be obtained, but for the alpha 2 frequency a significant difference between the circadian and the EEG power under cyclandelate was found using the sign test. Altogether a quantitative effect on brain activity was detected after oral application of cyclandelate, reaching its maximum before the blood concentration of the metabolites cyclandic glucuronide and mandelic acid reached their peak heights.
Adult↗
Kinetics of urinary excretion and effects on colour vision after exposure to styrene.
We evaluated the influence of the body burden of styrene on biological indices of exposure and the effects of this solvent on colour perception. The exposure of 19 workers was followed during a working week by personal sampling and biological monitoring. Although no significant difference in daily exposure was observed, pre-shift values of urinary styrene and urinary mandelic acid increased significantly during the week, and the regression line between external dose and biological exposure indices changed correspondingly. These data suggest that body burden can influence the results of biological monitoring of styrene. The effect of styrene on colour vision was evaluated in two further groups: 73 exposed workers and 53 referents and 36 pairs of workers and controls. A dose-related impairment was observed, which appeared to be synergistic with age and was not significantly improved by a one-month interruption of exposure. Our data show the need to improve biological monitoring of exposure to styrene and, in particular, to establish dose-effect and dose-response relationships between exposure and early effects. Urinary excretion of styrene and colour vision assessment represent, respectively, promising indices of exposure to and an effect of styrene.
Adult↗
Phaeochromocytoma--a rare cause of hypertension in an 11-year-old girl.
Severe sustained hypertension occurs in only 0.1% of the paediatric population and only about 2% of these patients will have an underlying endocrine cause. Phaeochromocytoma as a catecholamine-secreting tumour causing severe hypertension is exceedingly rare in children. A high index of suspicion and an awareness of the clinical spectrum are therefore necessary to make the diagnosis. Phaeochromocytomas can have protean manifestations which may be mistaken for a variety of clinical conditions. We highlight the problems encountered in making the diagnosis in an 11-year-old Chinese girl who presented with sustained hypertension, heart failure and transient renal impairment with two normal 24-hour urinary vanillyl mandelic acid (VMA) results before a third produced the diagnosis. We emphasize that total reliance on a single biochemical urinary screening is not acceptable. The measurement of urinary catecholamines or their metabolites increases the sensitivity of diagnosis. We recommend that in situations where biochemical screening is doubtful, appropriate imaging should be undertaken to exclude the diagnosis.
Adrenal Gland Neoplasms↗
Surveillance of early neurotoxic dysfunction.
Surveillance of early neurotoxic alterations was undertaken in 3 reinforced plastics plants, with a view to preventive intervention. Using a longitudinal study design, exposure parameters (environmental styrene in the respiratory zone of each worker and end-shift mandelic acid (MA)) and neurobehavioral performance (Neurobehavioral Core Test Battery and Field Assessment: Sensory Tests), were assessed at time zero (T0); recommendations were made to reduce exposure at jobsites with the highest risk. Reassessment was made two years later (T2). Complete exposure data was available for 118 workers at T0; 75 were still employed at T2; of these, 57 (76%) returned for testing. Those who returned had more seniority (p < 0.001) and higher MA (p < 0.01) and styrene (p < 0.05) levels at T0 than the others. Analyses, performed on the T0-T2 differences, showed improvement in exposure parameters in Plant 3, where lower levels were observed at T2 for styrene (p < 0.05) and MA (p < 0.001). workers in Plant 3 (n = 29) performed better (p < 0.05) at T2 for short term memory, perceptuo-motor speed, motor precision and manual dexterity; they reported more vigor (p < 0.05) and less anger (p = 0.07). This was not the case for the workers from the other plants. Generally, the T0-T2 difference in MA was associated (Spearman's Rho) with differences in color vision (p < 0.001), simple reaction time (mean and standard deviation), digit span forward, tension, fatigue and the number of symptoms (p < 0.05); aiming precision showed a similar tendency (p < 0.10). These findings suggest that group surveillance of early nervous system changes for jobs with exposure to neurotoxins, using a sensitive neurofunctional test battery, may be useful for preventive intervention.
Adult↗
[Usefulness of measurement of hormones in urine samples collected during the night period for the diagnosis of endocrine disorders].
It has been known that the measurement of adreno-cortical and medullary hormones in urine for 24 hours is the best way for diagnosis of the disease state. This is not only because hormone release shows circadian rhythm but also because the urinary excretion of hormones reflects the total amount of hormones produced for 24 hours. However, the civilized people, particularly the workers, are too busy to correct urine for 24 hours. Therefore, we aimed to evaluate whether the urine sample corrected for only 12 hours during night is useful for the diagnosis of adrenal diseases. Circadian rhythm of hormones in urine was evaluated by correcting urine every 4 hours in 18 normal adults. Diurnal variations of 17-ketosteroids (17-KS) and 17-hydroxycorticosteroids (17-OHCS) were evident; they showed the peak value during 8 AM and 12 AM, and the trough during 0 AM and 4 AM. Similarly, urinary noradrenaline and adrenaline showed the peak value at day time and the trough at night time. However, the rhythm was not observed in urinary dopamine and vanilyl mandelic acid (VMA). Under consideration of outpatient's convenience, urine sampled during night (between 8 PM and 8 AM) was evaluated. The amount of hormones during night was 35.9-46.9% of the total amount of the day, and the deviation was relatively small. The reference intervals (mean +/- 2SD) were as follows; 17-KS (n = 56, 2.8 +/- 2.4 mg/12 hours), 17-OHCS (n = 56, 2.0 +/- 2.0 mg/12 hours), 17-KGS (n = 52, 3.6 +/- 3.6 mg/12 hours), free cortisol (n = 43, 14.3 +/- 14.2 micrograms/12 hours), noradrenaline (n = 50, 12.9 +/- 9.8 micrograms/12 hours), adrenaline (n = 50, 2.1 +/- 4.0 micrograms/12 hours), dopamine (n = 50, 134 +/- 194 micrograms/12 hours), VMA (2.3 +/- 2.4 mg/12 hours). When the night periods urine in patients with adrenal disorders such as virilizing adrenocortical carcinoma, pituitary adenoma, adrenocortical hydroxylase deficiency, Addison's disease, hypopituitarism, Cushing's syndrome, pheochromocytoma was analyzed, the respective urinary hormone level corresponding to each disease was significantly changed from the reference interval. These results indicate that analysis of urine sample during night has advantage over the daily urine because the difference between normal and disease state is augmented when measured urinary during night.
Adenoma↗
Diagnostic difficulties associated with phaeochromocytoma--4 case illustrations.
The diagnosis of phaeochromocytoma can be extremely difficult with 40%-76% of cases escaping diagnosis during life. Until recently, the only available biochemical test for the detection of phaeochromocytoma in Singapore has been the 24-hour urinary vanillyl mandelic acid (VMA). Urinary VMA has been reported to have a high specificity (85%-100%) but variable sensitivity (28%-90%) in the diagnosis of this disease. In 1993, high performance liquid chromatography (HPLC) assays for the measurement of urinary catecholamines and metanephrines were introduced at the Singapore General Hospital. Since 1993, 4 cases of phaeochromocytoma have been detected at our institution. We report here, the diverse clinical presentations of these patients. The urinary-free catecholamine and catecholamine metabolite levels of these patients were compared with corresponding levels from 12 non-phaeochromocytoma patients. Using the reference value of 65.6 mumol/day, we found the urinary VMA to be a highly sensitive (100%) test with a specificity of only 31%. In contrast, a urinary total metanephrine level > or = 9,000 nmol/day was both sensitive (100%) as well as specific (100%).
Adrenal Gland Neoplasms↗