Immunoreactive creatine kinase-MB and creatine kinase isozyme concentrations during treatment of hypothyroid patients

Using a highly sensitive enzyme immunoassay (EIA) system, we determined creatine kinase isozymes, namely creatine kinase-MB and creatine kinase-MM, in sera of patients suffering from primary hypothyroidism with concomitant signs of myocardial affections before and during treatment. After oral administration of L-thyroxine, the augmented mass concentrations of serum creatine kinase-MB and creatine kinase-MM, and the increased catalytic activity concentrations of serum total creatine kinase and creatine kinase-MB gradually decreased in inverse proportion to the increased concentrations of serum triiodothyronine (T3) and thyroxine (T4). By the 6th to 8th week after treatment, the elevated levels of serum total creatine kinase and creatine kinase-MB catalytic activity concentrations (assayed by a routine method) and serum creatine kinase-MM mass concentrations (assayed by EIA) declined to normal values, while serum T3, T4, and thyroid stimulating hormone attained normal values. Serum creatine kinase-MB mass concentrations (assayed by EIA), however, still remained at the higher level, without complete recovery from myocardial damage, as shown by electrocardiogram (ECG). These data indicate that metabolic distortion still exists in the myocardium, as revealed by the high creatine kinase-MB mass concentration, especially as assayed by EIA, even though the plasma levels of thyroid hormones had returned to normal.

Cushing's syndrome with cortisol hypersecretion from one of bilateral adrenocortical adenomas: report of a case

We report herein the case of a 40-year-old man with Cushing's syndrome, diagnosed by clinical manifestations and endocrinological studies, who was found to have bilateral adrenocortical adenomas, one of which hypersecreted cortisol. The Cushing's syndrome was therefore attributed to primary adrenocortical disease, and the right adrenal tumor was resected and histologically diagnosed as a so-called black adenoma. After resection of the right tumor, the left adrenal tumor showed no signs of cortisol hypersecretion for the 23 months of follow-up until the patient died of peritonitis subsequent to the rupture of a duodenal ulcer. The left adrenal tumor was examined at autopsy and found to be a cortical adenoma. These data imply that the adrenal adenomas developed primarily from the adrenal gland itself, and that one of the tumors was well differentiated and secreted excess hormones, while the other remained in cell proliferation without hypersecretion.

Tyrosine hydroxylase indicates cell differentiation of catecholamine biosynthesis in neuroendocrine tumors

The intracellular localization of tyrosine hydroxylase (TH), which is the rate limiting enzyme in catecholamine (CA) biosynthesis, and its activity in various adrenal and other neuroendocrine tumors was studied. TH was strongly localized in adrenal medulla, pheochromocytoma, and paraganglioma, but was scatteredly expressed in neuroblastoma. TH was not detected in adrenocortical tumors, ganglioneuroma, and other neuroendocrine tumors. Neuron specific enolase (NSE) was found in all neuroendocrine tumors, but Grimelius staining showed only the secreting granules of the tumor cells. TH activity was significantly high in pheochromocytoma and paraganglioma as compared with that in normal adrenal gland, whereas TH activity was low in a neuroblastoma and was undetectable in other tumors. These findings indicate that TH correlates well with the biosynthetic function of CA in the tumor cell and, thus, both the immunostaining of TH and the measurement of its activity in adreno-medullary and related tumors may provide some information about the process of cell differentiation in these tumors.

[Structure and function of TRAP]

Thyroid hormone receptor (THR) binds to specific thyroid hormone response element (TRE). Using an electrophoretic mobility shift assay (gel-shift), Murray and Towel recently found that cell nuclear extracts enhance the binding of THR to TRE. This protein has been designated T3 receptor auxiliary protein (TRAP). Retinoid X receptors (RXR alpha, beta) can function as TRAP. TRAP forms a heterodimer with THR through the ligand binding domain of both receptors. This area contains leucine zipper like heptad repeats which can form amphipathic alpha-helixes. The ligand (9-cis retinoic acid) of RXR may or may not synergistically increase T3/THR-mediated transactivation. The effects of 9-cis retinoic acid depends on the nature of the TRE. One of the functions of TRAP may be to alter the expression of T3-regulated genes.

Localization of Cu/Zn and Mn superoxide dismutase in various thyroid disorders

The intracellular localization of Cu/Zn- and Mn-superoxide dismutase (SOD), which catalyze the dismutation of superoxide radicals (O2-) to O2 and H2O2, was studied in the thyroid tissue of various thyroid disorders by an immunohistochemical technique. The concentrations of both SODs in those tissues were measured also by a sandwich enzyme immunoassay technique. Copper/zinc-SOD in thyroid tissues were identified by immunocytochemical staining in most cases of papillary carcinoma and in some cases of other thyroid disorders. In normal follicular cells this enzyme is localized in the perinuclear cytoplasm, whereas in thyroid tumor or hyperplastic follicular cells it exists homogeneously in cytoplasm. Manganese-SOD stained strongly in papillary carcinoma and papillary-growing cells in the thyroid tissue of adenoma and Graves' disease. The concentrations of Cu/Zn-and Mn-SOD in thyroid tumor tissues and hyperplastic follicular disorders were significantly higher than those in normal thyroid tissue when they were compared as a function of protein or deoxyribonucleic acid contents. The ratio of Mn-SOD to Cu/Zn-SOD was significantly higher only in papillary carcinoma, except for other thyroid disorders as compared with that in the normal thyroid. In conclusion, SOD seems to be related to cell proliferation and differentiation in the thyroid follicular cell because Cu/Zn-SOD changes its localization in tumor and hyperplastic follicular cells and because the Mn-SOD concentration is increased in papillary carcinoma or papillary-growing cells.

Enhancement of DNA polymerase beta activity in the pituitary gland by hormonal feedback

The activity of DNA polymerase beta (beta-enzyme) in bovine and rat pituitary glands was remarkably higher in the anterior than in the posterior lobe. In sucrose gradient centrifugation, the activity in the anterior lobe of the bovine pituitary gland appeared at the sedimentation constant, 3.3 S, while that of rat pituitary gland appeared at 3.3 S, 7.3 S and 12 S, respectively. The activity in each fraction increased in the anterior lobes of rat pituitaries that were stimulated to release TSH by decreased thyroid hormone levels induced by an antithyroid drug. These results suggest that the activity of the beta-enzyme is high in the cells of the anterior lobe which are hyperfunctioned to produce pituitary thyreotrophic hormone and may be controlled by hormonal feedback regulation.

[Experiment on validity of skin resistance level as an index of arousal level]

It is important in establishing and improving work management and work planning to estimate the arousal level of workers during operation and monitoring tasks. This paper proposes a technique based on experimental results to estimate the arousal level during job execution. In this experiment, both a monotonous low workload task which degrades the arousal level and a high workload task which has an awakening action were alternately applied to five subjects for three hours. Skin resistance level (SRL) as an index of arousal level of the autonous nervous system was measured with subjective drowsiness and task performance, that is, signal omission probability for low workload task and both reaction time and error probability for high workload task, as indexes of arousal level of the central nervous system. The following results were obtained. (1) The results suggested that SRL as an index of arousal level of the autonous nervous system is significantly related and correlated with subjective drowsiness and signal omission probability as indexes of arousal level of the central nervous system. (2) The average reaction time and the error probability tended to increase by the application of high workload when the arousal level was degraded. The influence of degraded arousal continued for a short time and showed an unfavorable effect on task execution. The degree of this influence, however, differed between subjects. (3) SRL can be used as an index of arousal level of the autonous nervous system because the measurement is comparatively easy and is little influenced by artifacts due to body movements. (4) Using SRL at initial high workload period as the standard value, it is possible to quantify the SRL value at arbitrary time by estimating how many times the standard value goes into the SRL value. Based on this quantified value as an index of arousal level, comparison with task performance can be made. The proposed index of arousal level of the autonous nervous system showed a significant correlation with indexes of the central nervous system. This technique can be applied to various kinds of estimation on human characteristics accompanied with changes in arousal level.

[A review on assessment techniques for workers' physical and mental conditions by physiological measurements]

It was only a several decades ago that physiological measurements were recognized as effective indicators of human physical and mental conditions in occupational health or ergonomics. The recent rapid progress in sensor and signal processing techniques, however, made these available for practical evaluation techniques. This paper is an overview of the accumulated techniques in several fields including experimental psychology, physiology, medical sciences, and ergonomics. The major topics described herein are as follows: 1) properties and merits of physiological measurements compared with the other techniques, 2) applicability of various physiological indicators evaluated from noninvasive, ambulatory and continuous monitoring techniques, 3) practical physiological measurements and signal processing systems which can be applied at actual workplaces and environment, 4) effective and useful evaluation techniques of physiological indicators such as ECG, blood pressure, respiratory parameters, EEG, EBP, EMG, body movements, body temperature, perspiration, eye movements, CFF and electrodermal activities. Our review of 235 published papers has shown that physiological measurements have made a significant contribution to the assessment of physical and mental workload, CNS (central nervous system) activity level and work performance. However, further studies should be made on detail mechanisms and individual variations.

Cushing's syndrome induced by hypersecretion of cortisol from only one of bilateral adrenocortical tumors

A case of Cushing's syndrome induced by the unilateral (right side) dominance of cortisol secretion in the face of bilateral adrenal tumors is reported. The adrenal tumor resected on the right side was a so-called black adenoma and histologically without any findings of nodular hyperplasia. After resection of the adrenal adenoma, no findings of cortisol hypersecretion from the remaining adrenal tumor on the left side were observed until the present, suggesting that the tumor of the left adrenal gland is a nonfunctioning adenoma. These data imply that the adrenal adenomas have primarily developed from the adrenal gland itself, rather than from micronodular hyperplasia by corticotropin stimulation, and that one of these tumors produces excess hormones initially by corticotropin stimulation, but the other remains in cell proliferation.

Electrofocusing analysis of DNA polymerase beta in hypophysectomized rat testis

Isoelectric focusing studies indicated that three peaks of DNA polymerase beta (beta-enzyme) activity were focused at isoelectric point of 7.1, 8.2 and 9.1 in testes of sham-operated rats, whereas in testes of hypophysectomized rats only two peaks of the beta-enzyme activity appeared at pH 7.1 and 9.1 and the peak at pH 8.2 was reconstituted by the treatment of gonadotropins and testosterone. In the brain hypophysectomy did not affect the activities of isoelectrically different beta-enzymes. These facts imply that under in vivo conditions the beta-enzymes in testes focused at different isoelectric points are modified with unknown factors and the beta-enzyme focused at pH 8.2 is affected by pituitary hormones.

[Basic research on measurement of mental work load utilizing physiological information]

Various definitions and models have been proposed to evaluate mental work load, for example, task time analysis method and secondary task method based on single channel model. However, an evaluating method utilizing physiological information has been comparatively newly proposed. Therefore, this method has not been adequately examined with respect to its relation to be heretofore proposed methods and to its practical usefulness in evaluating mental work load. In this study comparison was made of various evaluating methods, i.e. task time analysis method, secondary task method, method utilizing physiological information, and subjective score method with emphasis on the method utilizing physiological information when a modeled experiment was conducted. In evaluating the regression by the experimental results, the adopted standard was time shared fraction (TSF), which was computed as the relative required time compared to actual permitted time based on the single channel model. The main results can be summarized as follows: (1) The evaluated TSF value is a useful index if it can be computed, because it reflects the individual ability of each subject, is proportional to the amount of given information, and is most faithful to the definition of single channel model. (2) The TSF value is significantly correlated to the value obtained by existing secondary task method and subjective score method. Thus, this result justifies the above mention. (3) In the adopted physiological indicators of this experiment, SRRP (skin resistance reflex pulse rate) has the strongest correlation to TSF value. Furthermore, this SRRP is relatively not affected by individual difference and is significantly correlated to subjective score and secondary task in the constant condition of atmospheric temperature and subject's arousal level and in the repetitive task.

Spontaneous recovery from hypopituitarism due to postpartum hemorrhage

A rare case is presented of a woman with spontaneous recovery from hypopituitarism following postpartum hemorrhage. One month after delivery, serum thyroid hormone, TSH, LH and FSH levels were low, and their secretion from the pituitary gland responded poorly to the TRH and LH-RH tests. Pituitary TSH response was normal 3 months after delivery. In the LH-RH test, pituitary LH and FSH response returned to normal at 2 months. Pituitary GH secretion and serum cortisol levels induced by ITT already responded normally one month postpartum. Excessive secretion of pituitary PRL was observed 3 months after delivery and improved gradually thereafter. These results indicate that the secretion of pituitary tropic hormones was sensitive to pituitary ischemia in the following order: TSH, gonadotropin, GH and ACTH. The disturbance of these hormones also persisted in the same order.

Hormonal regulation of DNA polymerase-beta activity in the rat thyroid gland

Using hypophysectomized rats, it has been shown that DNA polymerase-beta activity in the adrenal gland and testis is largely influenced by pituitary trophic hormones. Sucrose gradient centrifugation of thyroid extracts revealed three peaks of DNA polymerase-beta activity sedimenting at 3.3S, 7.3S and 12S. Of these, hypophysectomy induced a decrease in the 3.3S DNA polymerase-beta, whereas other molecular forms were affected only slightly. DNA polymerase-alpha and -gamma activities were unaffected by hypophysectomy. These changes in DNA polymerase-beta caused by hypophysectomy were reversed by daily i.p. injection of TSH. Furthermore, stimulation of the thyroid by excess TSH induced by the administration of 1-methyl-2-mercaptoimidazole resulted in an increase of all forms of thyroid DNA polymerase-beta. These results show that the level of DNA polymerase is relatively constant after hypophysectomy but that DNA polymerase-beta in the rat thyroid gland is also modulated by TSH mainly through the change of activity of the polymerase-beta which sediments at 3.3S.

DNA polymerase beta in human thyroid of Graves' disease and thyroid tumors

We have shown that the level of DNA polymerase beta of rat adrenal cortex is regulated by pituitary trophic hormones and may correlate with their endocrine function. Here we measured DNA polymerase beta activity in human thyroid tissues of various benign and malignant thyroid disorders in order to verify the correlation between DNA polymerase beta activity and endocrine function. In Graves' disease (hyperfunction), the level of DNA polymerase beta per cell was three times higher than in normal thyroid, while in undifferentiated thyroid carcinomas this enzyme level was lower than normal. Furthermore, DNA polymerase beta in the crude extracts of cancer cells showed larger molecular forms, ranging from five to 12S, upon sucrose gradient sedimentation. These observations further support the hypothesis that the activity of DNA polymerase beta correlates, in part, with the functional level of the endocrine organ and with cell differentiation.

Production of the alpha subunit of guanine nucleotide-binding protein GO by neuroendocrine tumors

We have found that neuroendocrine tumors (including neuroblastoma, ganglioneuroma, gut carcinoid, pheochromocytoma, medullary thyroid carcinoma, insulinoma, glucagonoma, prolactinoma, carotid body tumor, and small cell lung carcinoma) produce considerable amounts (about 1000-80,000 ng/g tissue) of the alpha subunit of guanine nucleotide-binding protein, GO (GO alpha), whereas nonneuroendocrine tumors contain less than 300 ng of GO alpha/g tissue. GO alpha in the neuroendocrine tumors was present both in the soluble fraction, and cholate-extractable membrane-bound fraction of tissues. Immunoblots of membrane fractions of neuroblastoma and carcinoid tissues confirmed that the immunoreactive substance in the tumor tissues was GO alpha. Immunohistochemically, GO alpha was localized consistently in the cell membrane and occasionally in the cytoplasm of neuroendocrine tumors. GO alpha was also detected in sera of 73% patients with neuroblastoma at diagnosis, whereas serum GO alpha concentrations in control children, or patients with nonneuroendocrine tumors were lower than the detection limit of the immunoassay method employed. Serum GO alpha concentrations in patients with neuroblastoma changed with the clinical course; they fell in patients responding to treatment and increased in patients who relapsed. Since GO alpha, a specific protein in the neural and neuroendocrine cells, was found to be produced in considerable amounts by all types of neuroendocrine tumors but not in nonneuroendocrine tumors, GO alpha might be a useful biomarker for neuroendocrine tumors.

[An experimental study on the prediction of heat stress of workers in a hot environment, with special reference to the relation between wearing suits, work load and environmental temperature]

Hardly any practical approaches have been made on prediction of appearance of heat-stress hazard, although basic studies have extensively been made, including various heat-stress indices. Hence, in the present paper, an applicational prediction equation is presented with regard to the permissible working time without heat-stress hazard on the basis of experimental results. The purpose of this experiment was to examine the significant correlations between elevated rectal temperature, working conditions such as wearing suits, work load, and environmental temperature. The results obtained can be summarized as follows. (1) A critical level of environmental temperature exists. When this level is exceeded, physiological indices such as rectal temperature rapidly increased. According to experimental results, the critical level was about 30 degrees C and the heavier the work load, the lower was the critical level. (2) Moreover, the heavier the wearing suit, the lower became the temperature level. This finding indicated that it was important to choose a suitable apparel under a hot environment in order to keep the workers safe from heat-stress hazard. (3) A general prediction equation of raising the level of rectal temperature compared with that of initial condition was proposed by analysing each experimental condition (suit, work load, and environmental temperature) by use of second order multiple regression method. This equation showed that elevation of rectal temperature was assumed to be proportional to the logarithm of the working periods. (4) The predicted values by this equation corresponded with the experimental values within +/- 0.2-0.3 degrees C, and the correlation coefficient was 0.96. This equation suggests that heavier suits elevated the rectal temperature about 2-3 degrees C when the work load and environmental temperature were moderate. (5) It is possible to predict the permissible working period by this equation. This may be applied to the working plan effectively. Appropriate working conditions can be chosen with regard to apparel, environmental temperature, and work load.

Serum beta-enolase in acute myocardial infarction

The enzyme beta-enolase (alpha beta and beta beta forms) is present in skeletal and heart muscle and catalyses the glycolysis of 2-phosphoglycerate to phosphoenolpyruvate. The enzyme was measured in serum samples from patients with acute myocardial infarction, angina pectoris, congestive heart failure, and idiopathic cardiomyopathy. Serum concentrations of beta-enolase were significantly increased in acute myocardial infarction but not in the other cardiovascular diseases. Activity peaked approximately 12 to 14 hours after an acute attack of chest pain, and then gradually decreased as the patient recovered. The rise and fall in beta-enolase concentration were faster and steeper than those of creatine kinase activity, particularly in patients in whom activities of both these enzymes were less high. The assay of beta-enolase, which is highly specific and sensitive, has considerable advantages for the early diagnosis of myocardial infarction and the diagnosis of a second episode of myocardial infarction because beta-enolase concentration increases very early and rapidly and clears quickly. These data imply that serum beta-enolase may be a more effective marker for early myocardial infarction, particularly in milder cases, than measurement of creatine kinase activity.

Increase in S-100b protein content in thyroid carcinoma

S-100b protein was detectable in the soluble fraction of thyroid tissue. The concentration of S-100b protein in thyroid carcinoma tissue was three to five times higher than in normal thyroid tissue and thyroid adenoma. It is, however, not higher in the thyroid tissue of Graves' disease. The increase of S-100b protein concentration was not remarkable in carcinomatous tissue of the stomach and other digestive organs. The calmodulin content in the thyroid carcinoma tissue increased but the increment was low compared to that of S-100b protein. These data suggest that S-100b protein may play a significant role in cell maturation or differentiation.

[Change in serum thyroid hormone levels in patients with acute myocardial infarction]

It has been reported that there is a decrease in the serum concentration of thyroid hormones in non-thyroidal illness. In the present study we made serial measurements of serum concentration of thyroid hormones [triiodothyronine (T3), thyroxine (T4), free triiodothyronine (FT3), free thyroxine (FT4), reverse triiodothyronine (rT3)], thyroid stimulating hormone (TSH) and thyroxine binding globulin (TBG) in 10 patients with acute myocardial infarction (AMI, Grade I, according to the classification of Killip & Forrester) during 14 days after onset. In the early phase of AMI, serum T3, T4, FT3 and FT4 levels decreased while rT3 increased. TSH and TBG levels, however, were unchanged. In the patients with a high peak creatine phosphokinase activity (greater than or equal to 400 mU/ml), the decrease in thyroid hormone and increase in serum rT3 levels were greater than in patients with a low peak value (less than 400 mU/ml), suggesting a correlation between severity of AMI and changes in serum thyroid hormone levels. Especially, serum FT3 levels fell below the lower limit of controls within 14 days, with the lowest levels and the rT3 peak on the third day after onset. These data suggest that in AMI peripheral conversion of T4 favours rT3 production and that low levels of serum FT3 and T3 protect the infarcted heart muscle against thyroid hormone action.

Congenital goiter sustaining normal level of serum triiodothyronine

We attempted to elucidate the deficient site of thyroid hormone biosynthesis in the thyroid gland and the mechanism of sustaining normal T3 level in sera of a patient with congenital goiter. TY, a 8-yr-old boy, first noted the onset of a diffuse goiter at the age of 2. There was no clinical evidence of hypothyroidism except for the slight impairment of intellectual development and the awkward physical activity. BMR, T3-RSU and T4 showed low values (-13%, 20.8% and 2.2 micrograms/dl), but serum T3 was normal (180 ng/dl). Serum TSH was 18 microU/ml. The intrathyroidal T3 and T4 were slightly low. Thyroidal 131I uptake was high, but KSCN discharge test was negative. Percent distribution of 131I labelled amino acids in the pancreatin digested thyroid homogenate was 17.4% in MIT, 33.4% in DIT and 11.3% in T3 and T4. Thyroid iodide peroxidase activities in mitochondrial and microsomal fractions were slightly low (19.6 and 26.8 (normal: 32 +/- 3.0 and 37.4 +/- 9.5) mumoles/mg protein). The activity was not increased by the addition of hematin. Thyroglobulin was found to be normal. A biological half life of 131I labelled T4 was shorter (3.5 days) than that of the normal. Electron microscopic examination exhibited the increment and expansion of endoplasmic reticulum in the follicular cell. Low iodide peroxidase activity of this patient may correlate to low T3 and T4 level in the thyroid cell. Moreover, shortened biological half life of T4 implies that normal T3 level in serum is sustained by the accelerated conversion of T4 to T3 in peripheral tissues.(ABSTRACT TRUNCATED AT 250 WORDS)

Effect of calmodulin inhibitors on thyroid hormone secretion

The effect of calmodulin inhibitors, N-(6-aminohexyl)-5-chloro-1-naphthalene sulfonamide (W-7) and trifluoperazine, on TSH-induced thyroid hormone secretion from rat thyroid was examined in vivo and in vitro. The ip administration of 5 mg W-7 to the rat inhibited T4 and T3 secretion from rat thyroids at 2, 3, and 4 h after the ip injection of 2 IU TSH, and so did the ip injection of trifluoperazine at 3 and 4 h. However, the ip injection of N-(6-aminohexyl)-1-naphthalene sulfonamide as a control substance did not show any significant inhibition of T4 and T3 release. To identify the site of action of calmodulin, the effect of W-7 on (Bu)2cAMP-induced thyroid hormone secretion was tested in vitro. One hundred micromolar W-7 completely inhibited T4 release from the rat thyroid when it was enhanced by TSH or (Bu)2cAMP, suggesting that the inhibitory effect of W-7 is subsequent to cAMP formation. These results suggest that calmodulin may play a role in thyroid hormone secretion from the thyroid, acting beyond cAMP formation.

Immunohistochemical study of neuron-specific enolase and CA 19-9 in pancreatic disorders. The value of neuron-specific enolase as a marker for islet cell and nerve tissue

Immunohistochemical studies of neuron-specific enolase were performed on pancreatic tissues from patients with insulinoma, nonfunctioning islet cell tumor, chronic pancreatitis, and pancreatic adenocarcinoma, and from 5 normal patients. The concentration of neuron-specific enolase was also measured in the sera of patients and in the pancreatic tissue, and the tissues were stained for carbohydrate antigen 19-9 by immunohistochemical techniques. Neuron-specific enolase was localized in nerve fibers, normal islet cells, and islet cell tumors; its concentration was elevated only in the tissue of islet cell tumors and in serum from patients with insulinoma. In the pancreatic tissue of pancreatitis or pancreatic adenocarcinoma, various changes in acini and islets were present. The altered islets stained clearly for neuron-specific enolase and could easily be distinguished from altered, unstained acini in cases of pancreatitis or pancreatic adenocarcinoma. Islets in the pancreatic tissue remained intact with various morphologic changes, although acini had degenerated severely. Carbohydrate antigen 19-9 was localized in all the carcinoma cells in the pancreatic tissue and in some of the normal pancreatic ducts. No cells were simultaneously immunostained by anti-neuron-specific enolase and anti-carbohydrate antigen 19-9 antibodies. Thus, neuron-specific enolase is a good marker for islet cell tumor, and is valuable for examining islets in pancreas with various disorders both alone and in combination with other tumor markers.

Enolase subunits in patients with neuroendocrine tumors

Concentrations of the alpha-, beta-, and gamma-subunits of enolase in surgically resected tumors and serum obtained from patients with various endocrine tumors were measured by a sensitive enzyme immunoassay system. Tissue concentrations of the gamma-subunit were significantly elevated in patients with neuroendocrine tumors concurrent with high concentrations of the gamma-subunit in their serum, which fell to normal in 90% of those who underwent tumor resection. Immunohistochemical analysis revealed that considerable amounts of the gamma-subunit were contained specifically in these tumors. These results indicate that the gamma-subunit of enolase is a useful marker for diagnosing and monitoring patients with neuroendocrine tumors.

High activity of cyclic 3',5'-nucleotide phosphodiesterase in sera of patient with phaeochromocytoma

Our previous observations that serum cyclic 3',5'-nucleotide phosphodiesterase activity varied in thyroid disorders and was positively correlated with thyroid function stimulated us to investigate the phosphodiesterase levels in sera of patients with pituitary and adrenal disorders, and the response to glucagon in normal subjects. Both serum cyclic AMP phosphodiesterase (cyclic AMP-PDE) and cyclic GMP phosphodiesterase (cyclic GMP-PDE) activities were measured at a low substrate concentration. Serum cyclic AMP-PDE activity was elevated in five patients with phaeochromocytoma and was not elevated in patients with Cushing's syndrome or acromegaly, compared to the level in normal subjects. Increased enzyme activities returned to normal after resection of the tumours. Intramuscular injection of glucagon to five healthy subjects elevated cyclic AMP levels and cyclic AMP-PDE activity in plasma. These results imply that the increased cyclic AMP level by the activation of cyclase may have induced cyclic AMP-PDE in the target organ and the soluble cyclic AMP-PDE may leak into blood vessels from target organs.

Effect of somatostatin and dopaminergic agents on bovine pituitary phosphodiesterase activity

The effects of somatostatin and dopaminergic agents on pituitary cyclic nucleotide phosphodiesterases that had been partially purified through DEAE cellulose column chromatography were studied. Somatostatin, L-dopa, dopamine and CB-154(2-bromo-alpha-ergocriptine) competitively inhibited the pituitary cyclic AMP phosphodiesterase activity, especially that of the low Km enzyme. This inhibition was most potent in the case of somatostatin and CB-154.