[Determination of prolactin reference intervals in different age groups].

BACKGROUND: Clinical diagnostic laboratories (CDL) have at their disposal various automated systems for the measurement of biochemical parameters and markers such as prolactin. Each of the test systems manufactures offers its own alternate design of the method, which makes standardization difficult. In endocrinological practice, the problem of result discrepancies often arises. In hormonal assays, the clinical picture of patients sometimes does not correspond to the reference values provided by the manufacturers, which determines the need to develop the method-specific reference values for a specific population. The difficulty in interpreting basal prolactin levels is not only due to a transient increase in the hormone levels caused by stress or excessive physical exertion, but also due to a significant variability of indicators in the same patient, even if all recommendations for blood sampling are followed. AIM: The aim of the study to determine the reference values in serum samples of women, men and children of different age groups for the VITROS Immunodiagnostic Systems and compare the results with the "expected prolactin levels" recommended by the method manufacturerMATERIALS AND METHODS: The monocentric study included 879 serum samples of apparently healthy subjects who were admitted to the Endocrinology Research Center. Measurements were performed using the VITROS ECi 3600 automatic chemiluminescence analyzer (Ortho-Clinical Diagnostics, Great Britain). RESULTS: For adult men and women reference values were 66-436 and 94-500 mIU/l respectively. When comparing the results of prolactin determination in women and men of the studied cohort with the "expected values" of the VITROS ECi 3600 manufacturer a systematic shift towards an increase in lower and upper limits of the reference values was found in both -cohorts. CONCLUSION: The obtained reference values of prolactin can be use in the determination of prolactin in the Russian population for VITROS ECi 3600 Immunodiagnostic Systems.

[Calcitonin measurement in fine-needle washout fluids in detecting medullary thyroid cancer].

BACKGROUND: The diagnostic value of calcitonin measurement in fine-needle aspiration biopsy wash-out fluid is a promising tool in the diagnosis of medullary thyroid cancer. AIMS: We assessed the potential usefulness and the diagnostic significance of Ct-FNAB alone in comparison with cytology in the diagnosis and localization of primary or metastatic MTC. MATERIALS AND METHODS: For this purpose, we retrospectively examined data from 67 patients with suspicious thyroid nodules and/or lymph nodes who ultimately underwent surgical treatment at the Endocrinology Research Centre in 2015-2020. The primary endpoint of the study was to evaluate the diagnostic accuracy of Ct-FNAB when compared to cytological examination. The secondary endpoint was to determine the optimal diagnostic level for use in clinical practice. RESULTS: The obtained results showed that high Ct-FNAB concentrations were present in all histologically proven MTC, either in thyroid gland (sensitivity 92.5%, specificity 100%) or neck masses (sensitivity 88.5%, specificity 100%). The optimal diagnostic threshold for Ct-FNAB values from thyroid nodes was > 122 pg/ml, from lymph nodes >35.8 pg/ml. CONCLUSIONS: Our findings suggest that Ct-FNAB is a highly reliable diagnostic procedure to identify primary and recurrent/metastatic MTC. The actual relevance of this technique in the management of MTC needs further longitudinal studies in a larger number of patients.

Analytical platforms Vitros ECi 3600 and Cobas 6000: comparative analysis of prolactin measurement.

Prolactin is a polypeptide hormone secreted by the lactotrophic cells of the anterior pituitary gland and has a wide range of biological effects in the human body. Accurate measurements of prolactin concentration are essential in obtaining biochemical data to support clinical decisions in the diagnosis, treatment and prevention of diseases of the pituitary gland, reproductive, immune and other body systems. The aim of our study is to carry out a comparative analysis of the serum prolactin measurement determined by the two analytical platforms Vitros ECi 3600 (Ortho-Clinical Diagnostics) and Cobas 6000 (Roche). Serum samples from 664 patients undergoing examination at the Endocrinology Research Center were included in the study. Comparative analysis of serum prolactin measurement showed that results obtained by the two analytical systems are consistent with each other (r = 0.89, p<0,05). Clinically accuracy of prolactin measurement and to a large extent using the same method is of particular importance in primary diagnosis, treatment and long-term follow-up of the patient.

[Aldosterone- and cortisol-co-secreting adrenal tumors: an uneasy sum of well-known parts (review)].

Primary aldosteronism (PA) is the most common form of secondary arterial hypertension. In patients with PA, more so than in the general population, there is a prevalence of insulin resistance, diabetes mellitus, metabolic syndrome, osteoporosis, and symptoms of depression; these conditions are more likely to manifest a gluco- rather than mineralocorticoid excess. This fact is of particular importance in light of recent studies that have shown that PA is often associated with glucocorticoid excess. Since the first reports of cases of combined secretion of aldosterone and cortisol in 1979, the number of cases of so-called Connshing syndrome has increased. An analysis of data from recent studies suggests that hypercortisolism in PA is closely associated with an increased risk of cardiovascular complications, metabolic disorders and post-surgical adrenal insufficiency. The most important diagnostic problem in adenomas with combined secretion is the risk of false interpretation of the results of adrenal venous sampling (AVS). The indications that suggest aldosterone-and-cortisol-co-producing adenoma are the lack of suppression of cortisol levels following a night test with 1mg of dexamethasone, and an adrenal tumo of over 2.5cm. As an alternative test capable of differentiating this type of tumor, a number of researchers have proposed measuring the level of so-called hybrid steroids in the peripheral plasma and urine. Taking into account the high prevalence and potential risks, ruling out of excess corisol secretion is obligatory in all cases of PA before AVS and when planning surgery.

[Primary hyperaldosteronism: difficulties in diagnosis].

Primary hyperaldosteronism (PA) - is the clinical syndrome, results from autonomous of the major regulators of secretion, aldosterone overproduction by a tumorous or hyperplastic tissue in adrenal cortex. Being the most frequent cause of secondary hypertension, PA may be represented by disorders with unilateral or bilateral aldosterone overproduction and differential diagnosis between them is crucial for choosing a right therapeutic approache: lifelong medical therapy with mineralocorticoid receptor antagonists or unilateral adrenalectomy. Adrenal venous sampling (AVS) is currently the «gold standard¼ test for identifying laterality of excess hormone production, unlike imaging tests, sensitivity and specificity of which is not enough, due to inability to evaluate functional activity with confidence, and also to limitations in detecting tiny abnormalities of adrenals, such as microadenoma or hyperplasia. Excluding certain cases, AVS is recommended to patients with confirmed PA, planning surgical treatment, to determine the lateralization of aldosterone hypersecretion. Described clinical case of patient with confirmed lateralization from adrenal without any detected lesions on CT-imaging and nonfunctioning tumour on contralateral side, highlights the importance of using AVS for decision to refer patients for surgery.

[The comparative analysis of the results of detection of testosterone in blood serum applying analyzers Architect and Vitros and tandem mass-spectrometry, a highly efficient fluid chromatography technique.]

The testosterone is a key element of hypothalamus hypophysis gonad system. Its physiological role in males is well known and consists primarily in formation of male phenotype and support of spermatogenesis. The evaluation of androgenic status is necessary in case of such wide specter of clinical symptoms and pathological states as hypogonadism, delayed of premature puberty, polycystic ovary syndrome, particular types of cancer, etc. The precise measurements of testosterone concentrations have a decisive value in case of receiving biochemical data for supporting clinical decisions at diagnostic, treatment and prevention of androgenic diseases. The purpose of the study is to carry out a comparative analysis of the results of detection of testosterone in blood serum using analyzers Architect 2000 and Vitros 3600 and applying technique of highly-effective fluid chromatography - a tandem mass-spectrometry. The analysis was applied to samples of blood serum from 230 patients send to the endocrinological research center of Minzdrav of Russia. The comparative analysis of the results of detection of concentrations of testosterone demonstrated consistent difference in absolute values. However, a statistically significant correlation (р < 0,05) between values of testosterone obtained by different techniques was established. The correlation coefficient in different groups of patients made up to 0,894-0,920 and 0,955--0,965 correspondingly to comparing the results of Architect and Vitros and highly-effective fluid chromatography - a tandem mass-spectrometry. The calculated percentage of distribution of the results of detection of content of testosterone by the ranges of expected values demonstrated an admissible comparativeness of obtained results from point of view of practical diagnostic. The choice of technique of detection of biochemical parameters in case of primary diagnostic is very important. However, even more important is the application of the very same technique in treatment and long-term observation of patient.

[The modification of technique of detection of free cortizol in urine.]

The detection of free cortizol in day urine is an informative marker for diagnosing conditions of hypo- and hypercorticism. Up to 1% of cortizol, in invariable form and with no association with proteins and secreted by adrenal cortex, is excreted with urine during a day. The level of free cortizol in urine has no dependencies from day variation of hormone in blood and hence it reflects total secretion of cortizol by adrenal cortex. Besides, as a rule a direct proportional dependence exists between level of free cortizol in urine and level of biologically active cortizol in blood. The developers of automated systems propose various techniques of detecting cortizol not only in blood but in other biological fluids too. In our laboratory techniques of detection of level of free cortizol in day urine were approved, modified and adapted meant for analyzer Vitros ECi (Ortho Clinical Diagnostics, Great Britain) and analyzer Cobas 6000 (Hoffmann-La Roche, Switzerland). The comparison of results obtained by these techniques was carried out (r = 0,96-1). The reproducibility of detection of cortizol was evaluated by force of analysis of every sample of urine in one and various settings. The spread made up to 1,7-3,7% for one setting and 5,2-6,7% for various settings. The schemes were proposed to detect level of free cortizol in urine for analyzer Vitros ECi (with preliminary extraction by diethyl ether and subsequent removal of water fraction by force of freezing), and also for analyzer Elecsys (with preliminary extraction by dichlormethane and subsequent separation of phases by centrifugation and evaporation of organic phase by force of vacuum concentrator).

Comparative Analysis of Clinical, Hormonal and Morphological Studies in Patients with Neuroendocrine ACTH-Producing Tumours.

This paper highlights the problem of neuroendocrine tumours (NETs) with clinical symptoms of hypercorticism caused by hypersecretion of adrenocorticotropic hormone (ACTH) by tumour cells. In most cases (85%), the tumours were localized in the pituitary gland (Cushing's disease); 15% of the patients had an extrapituitary tumour that manifest as an ectopic ACTH secretion (EAS). Comparative analysis of clinical, hormonal, histological, and immunohistochemical characteristics of pituitary and extrapituitary ACTH-secreting NET was performed. It included 46 patients with CD and 38 ones exhibiting ectopic ACTH secretion (EAS). Results of the study suggest differences between CD and EAS in terms of the severity of clinical manifestations and duration of the disease. Hormonal studies showed that EAS unlike CD was associated with high plasma ACTH and cortisol levels, late-evening salivary cortisol and daily urinary free cortisol, the absence of a 60% or greater reduction of cortisol in the HDDST test, and the presence of a low (less than 2) ACTH gradient in response to desmopressin administration with catheterization of cavernous sinuses. The study of morphofunctional characteristics of the removed NET demonstrated the ability of both pituitary and extrapituitary NETs to express ACTH as well as GH, PRL, LH, and FSH. The angiogenic markers (CD31 and VEGF) were detected with equal frequency regardless of the NET localization. The histological structure of all corticotropinomas suggested their benign origin, but extrapituitary NETs were represented by different morphological types with varying malignancy, invasiveness, and metastatic properties. A higher cell proliferation potential (Ki-67) was documented for NET in patients presenting with an ectopic ACTH secretion compared to those having corticotropinomas.

[The saliva cortisol level test using the automatic immunochemical analyzer Cobas e601 (Roche) to diagnose endogenous hypercorticalism in patients with obesity].

The saliva cortisol level test applies to diagnose endogenous hypercorticalism. However the methods of die format immunoassay traditionally used do not make it possible to get the study results on-the-fly. Also, reference interval and optimal takeoffs differ under implementing various techniques of cortisol tests. The purpose of actual study is to investigate the possibilities of electrochemiluminescent technique of testing free cortisol in saliva. The device Cobas e601 was applied to diagnose endogenous hypercorticalism in patients with obesity. The saliva samples were collected at 11 PM from 98 healthy volunteers and 123 patients with obesity (in 45 cases endogenous hypercorticalism was diagnosed). In total, 205 persons donated saliva at 11 PM two days running to evaluate the technique reproducibility. The samples of 197 individuals were frozen to implement the immune-enzyme assay. The minor test with dexamethasone was applied to patients with suspected endogenous hypercorticalism. The diagnosis of endogenous hypercorticalism was finally confirmed after the results of histological analysis of post-operative material or autopsy. Among healthy volunteers, the reference interval on indicators consisted 0.5-9.4 nMol/l. The correlation coefficient under free cortisol measuring at the same time two days running was -0.785. The optimal takeoff to diagnose endogenous hypercorticalism in patients with obesity consisted 9.4 nMol/l, sensitivity--84.4% (95% confidence band 71.2-92.2%), specificity--92.3% (95% confidence band 84.2-96.4%), predictive value of positive result--11.0 (95% confidence band 5.0-23.9), predictive value of negative result--0.17 (95% confidence band 0.08-0.33) and likelihood ratio for positive result--65.1 (95% confidence band 20.4-207.6). The two-fold cortisol test in saliva using immune-enzyme assay and minor test with dexamethasone with their diagnostic capabilities corresponded to one-fold saliva free cortisol test using electrochemiluminescent technique. The one-fold free cortisol test in saliva collected in 11 PM using the analyzer Cobas e601 for electrochemiluminescent immunoanalysis is a convenient and informative endogenous hypercorticalism screening technique in patients with obesity.

[The diagnostic value of macroprolactin in hyperprolactinemia].

Macroprolactinemia (MP) in which there is a discrepancy between prolactin (P) levels and clinical symptoms has recently generated great interest among physicians of various specialties since not the whole of P is biologically active. The diagnosis of this condition is a topical problem. The purpose of the investigation was to detect high molecular-weight or big big P in patients with hyperprolactinemia (HP) of various genesis and to define its clinical importance. A hundred and one females with HP (P > 700 mU/l) were examined. In each patient, biologically active monomeric P was measured via treatment of polyethylene glycol (PEG) 6000. MP was detected in 23% of the examinees. Among them, only 11 females had clinical symptoms of the disease: 72.7% complained about menstrual irregularities; galactorrhea and headache were observed in 18.3 and 9.0%, respectively. The remaining 12 females had no clinical symptoms of HP. MP in which the clinical symptoms are feebly marked has been found to be not a rare condition. The determination of big big P in HP is of diagnostic value. It is recommended that the serum separation diagnostic technique using PEG should be made routine in the examination of patients with HP, particularly in the discrepancy of biochemical and clinical data and in idiopathic HP.

[Adrenal cortical steroidogenesis and adrenal androgen secretion in Cushing disease].

The daily time course of changes In the secretion of dehydroepiandrosterone, its sulfate, and Cortisol, as well as their precursors (17-α-hydroxypregnenolone, 17-α-hydroxyprogesterone, and 11-deoxycortisol) was studied in patients with Itsenko-Cushing syndrome and disease. The mean daily blood concentrations were calculated for each hormone. The activity of the enzymatic systems of steroidogenesis was estimated from the ratio of the mean daily concentrations of the precursor of an enzymatic reaction to those of its product. The findings suggest that production of elevated concentrations of corticosteroids (both Cortisol and androgens) through the Δ5-pathway with the enhanced activity of 11ß-hydroxylase and sulfatase is characteristic of patients with Itsenko-Cushing disease. In patients with Itsenko-Cushing syndrome, the generation of higher Cortisol levels is accomplished through the Δ4-pathway whereas the synthesis of androgens through the Δ5-pathway is minimal due to the decreased activity of 17,20-desmolase.

[Biochemical markers of congenital adrenal hyperplasia and impaired steroidogenesis].

The paper deals with the problems In the biochemical diagnosis of congenital adrenal hyperplasia caused mainly by adrenal 21-hydroxylase deficiency. It presents data on the adrenal cortical synthesis of corticosteroids and discusses whether different biochemical markers, including the levels of blood deoxycortisol and those of urinary pregnantriol and pregnantriolone, may be used in neonatal screening and later diagnosis of congenital adrenal hyperplasia.

[Elevated level of methylated catecholamine derivatives is a pathognomic laboratory sign of pheochromocytoma].

The levels of the methylated catecholamine derivatives (MCD) metanephrine and normetanephrine were measured in 46 patients operated on. The patients were divided into 2 groups: 1) 24 patients in whom chromaffinoma was histologically detected; their age varied from 9 to 75 years (mean 37.8 years); 2) 22 patients who had undergone adrenal cortical tumors or retroperitoneal tumors of extraadrenal genesis; their age ranged from 11 to 67 years (mean 44.3 years). In this group of patients, a histological study revealed aldosteromas in 7 cases, hormonally inactive adrenal cortical adenomas in 6, adrenocortical carcinoma in 5, corticosteroma in 1, adrenal lymphosarcoma in 1, adrenolypoma in 1, and renal cancer in 1. In all the patients from Group 1, there was an increase of one MCD index for instance of less than 110% of the upper normal range. The average excess of MCD levels over the upper normal range is 456% for metanephrine and 574% for normetanephrine. No increase in the level of daily MCD excretion was found in 21 out of the 22 Group 2 patients with nonchromaffin adrenal and retroperitoneal tumors. In this group, 1 patient with histologically verified mixed-cell adenocarcinoma of the adrenal cortex was observed to have a daily metanephrlne excretion increase by 17% above the upper reference range. Thus, the sensitivity of the method was 100%; its specificity was 95.5%. The lower confidence diagnostic interval for the values of daily MCD excretion was 714 ng/day for metanephrlne and 1500 ng/day for normetanephrine. The procedure for determining free MCD in plasma has a high sensitivity and specificity and may be once used as a screening for the symptomatic nature of disease in patients with arterial hypertension.

[Diagnostic value of the determination of total testosterone in the serum and free biologically active testosterone in the saliva in men].

The study was undertaken to provide evidence that the salivary concentration of free testosterone (FT) well correlates with the serum level of unbound testosterone in men. Recent articles demonstrate that the results obtained by the use of especially automatic systems are incorrect. Anew luminescence enzyme immunoassay has been now put into practice. Its high analytical (6.2 pmol/l) and functional (17.3 pmol/l) sensitivities allow the quantification of minor salivary concentrations. In healthy males, the morning salivary concentration was 369 pl/lmo (median) with a range of 263-544 pmol/l, which is statistically higher than that in males with androgen deficiency (215 pl/lmol/I (median) with a range of 51-249 pmol/l. Once-weekly remeasurement of salivary FT during 5 weeks showed the high stability of results over time with a variation coefficient of 9% (range 5-23%). The study indicated that FT in the morning salivary sample well correlates with the calculated FR in the blood of both healthy males (R = 0.754; p = 0.001) and patients with androgen deficiency (R = 0.889; p = 0.0001).

[The nonclassical form of congenital adrenal cortical dysfunction in adolescent girls].

The study was undertaken to define the frequency of nonclasslcal 21-hydroxylase deficiency confirmed by CYP21 gene mutations in girls with pubertal hyperandrogenlsm, to estimate the value of clinical and hormonal markers of nonclasslcal 21-hydroxylase deficiency. Eighty-five girls aged 5-17 years who had hyperandrogenlsm (pubertas precox, hirsutism, acne vulgaris). All the examinees underwent adrenocorticotropic hormone (ACTH) (Synacthen-depot) test. After detecting the hormonal markers oj"nonclassical21-hy-droxylase deficiency (the baseline level of 17- О HP being was above 9 nmol/l and/or above 45 nmol/l after A CTH stimulation), the authors analyzed the most common CYP21 gene mutations. The frequency of nonclassical 21-hydroxylase deficiency supported by CYP21 mutations In the girls with hyperadrogenlsm was 8.3%. There were no clinical differences between the nonclassical form of 21-hydroxylase deficiency and other forms of hyperandrogenlsm. The high baseline 17-OHP ( > 20 nmol/l) is the most specific hormonal marker of nonclasslcal 21-hydroxylase deficiency. Glucocorticoid therapy is indicated for patients with substantially accelerated growth and bone maturation and in those with menstrual irregularities as oligomenorrhea or amenorrhea.

[Early and late results of neurosurgical treatment with Itsenko-Cushing disease].

То study the efficiency of neurosurgical treatment of the Itsenko-Cushing disease (1CD), the authors analyzed the early and late results of adenomectomy in 99 patients (90 females and 9 males) with ICD. The diagnosis of ICD was verified on the basis of hormonal studies, functional tests, and the results of topic diagnosis. All the patients had an active stage of the disease and a pituitary tumor, as evidenced by magnetic resonance Imaging (MRI). Out of the 99 patients, 75% had a microadenoma of the pituitary and 25% had its macroadenoma. No correlation was found between the sizes of a tumor, the duration of the disease, and the severity of hy-percorticism. The Indication for surgery was a well-defined localized pituitary tumor as verified by MRI. The patients tolerated a neurosurgery well and complications as incoming diabetes insipidus were observed only in 12%, which is in agreement with the data available in the literature. Algorithms were developed for postoperative management of these patients. The findings have indicated that the development of the hormonal and clinical signs of hypocorticism serves as a good predictive marker of a radically performed operation. Six months after surgery, 82% of the patients were at remission. At an average 8.6-year follow-up, remission continued to be in 69(85.2%) of 81 patients. After surgery, patients with ICD should be, however, followed up since 14% developed a recurrence in the late postoperative period.

[Effect of desmopressin on the production of corticosteroids in patients with different forms of hypercorticism].

То investigate the direct effect of desmopressin (DP), a vasopressin agonist, on the adrenal cortex, the authors studied a response of the pituitary and all three adrenal cortical areas in patients with different forms ofhypercorticism (active stage): ACTH-dependent Itsenko-Cushing syndrome, ectopic ACTH-dependent syndrome, corticosteroma. The levels of ACTH, cortisol, dehydroepiandros-terone sulfate, and aldosterone were used to assess a response to DP 15, 30, 60, 90, and 120 minutes after administration. There were several types of a response of corticosteroids to DP: 1) an increase in the level of ACTH and, subsequently, in the concentration of either all test steroids, one of the steroids, or two steroids in different combinations; 2) an elevation of the concentration of steroids in different combinations irrespective the response of ACTH to DP. Thus, there are patients with hypercorticism whose adrenals respond to DP by the higher synthesis and secretion of glucocorticoids (cortisol), mineralcorticoids (aldosterone), and adrenal androgens (dehydroepiandrosterone sulfate). The findings suggest that there are "ectopic" receptors to vasopressin in the adrenal cortex of patients.

[Comparative analysis of the determination of serum testosterobe levels by different methods].

The serum concentration of total testosterone were measured in 100 male patients aged 19-65 years who had visited the clinic and polyclinic of the Endocrinology Research Center, Russian Academy of Medical Sciences for complaints about different dysfunctions of the endocrine glands. Testosterone was measured by the well-known currently available technologies: automatic Vitros ECi, Architect, and Access multianalyzers, manual Delfia and DRS enzyme immunoassay kits, and radioimmunoassay (RIA) that had been developed within the framework of the WHO Human Reproduction Programme and adjusted by the reference assay (gas chromatography/mass spectroscopy). The closest results were obtained when determining the level of testosterone by RIA and by means of the Vitros ECi multianalyzer (13.1 vs 13.0 nmol/l, medians). All other technologies demonstrated a low correlation with RIS and had positive biases, especially with the use of the Delfia kits (as high as 60 and, at low concentrations, 100%). The positive bias tends to decrease in patients with higher testosterone levels ( > 10 nmol/l) for all studied methods.

[The specific features of thyrotoxicosis and euthyroid hyperthyroxinemia developed due to the use of cordarone]. / Osobennosti tireotoksikoza i eutireoidnoi gipertiroksinemii, razvivaiushchikhsia na fone priema kordarona.

Thyrotoxicosis (TT) is one of the thyroid (T) dysfunctions occurring with the use of cordarone. The clinical features of TT were studied in cordarone-treated patients living in Moscow and its regions (mild and moderate iodine deficiency regions). The patients were examined by using currently available procedures for measuring thyroid-stimulating hormone, free thyroxine, free triiodothyronine, antibodies to TH, TPO, interleukin-6 (IL-6), and C-reactive protein (CRP), and by employing T ultrasound study, Holter ECG monitoring. TT was ascertained to develop in the presence of both the pathologically altered (16/23, 69%) and intact T (7/23, 31%). Examining the course of cardiac arrhythmias (CA) in developed TT has established that this condition gives rise to their recurrence. As compared with the control group, the patients with TT were not found to have higher levels of IL-6 and CRP (p > 0.05; Mann-Whitney test). Therapy with thyrostatic agents alone or in combination with glucocorticosteroids normalizes the levels of thyroid hormonesfollowing, on the average, 2-3 months. Euthyroid hyperthyxinemia (EHT) is frequently recorded with the use of cordarone. Examination of 20 patients with EHT has revealed organic pathology in 13 (65%) patients and its absence in 7 (35%). Recurrences of prior CA have not been found in EHT (p < 0.05; McNemar test). The confidence interval for the difference of relative frequencies of signs did not include 0). Thus, TT is a condition that leads to the fact that cordarone loses its antiarrhythmic effects and TT requires compulsory treatment. If required, therapy should be performed during the continued administration of the drug. EHT is not thyrotoxicosis, which is to be followed up.

Endocrine and reproductive health status of men who had experienced short-term radiation exposure at Chernobyl.

Hormonal and semen parameters in 416 men aged 25-45 years were examined: 328 were men who cleaned the territory around the Chernobyl nuclear reactor (called 'liquidators') and 88 were healthy age-matched controls. The dose of radiation received by the liquidators was 0.16 +/- 0.08 Gy. LH, FSH, prolactin, testosterone and cortisol levels were assayed using WHO-matched reagents. Semen analyses were performed according to the WHO Manual (1992). The mean concentration of all hormones in liquidators and controls were within the WHO-defined normal range. The mean levels of LH and cortisol in liquidators were significantly lower (p = 0.013 and p < 0.001, respectively) and testosterone significantly higher (p = 0.023) than in controls. The variations in hormone levels in liquidators were not correlated with the acquired doses of radiation as measured by personal dosimeters (film badges). Semen parameters in a subgroup of 70 liquidators were within the normal WHO-defined range. The percentage of normal forms of spermatozoa in liquidators (35.0 +/- 13.1%) was significantly lower (p < 0.015) than in a control group (42.8 +/- 8.9%). The study has shown that exposure of men to relatively short-term radiation did not cause long-lasting disruption of their endocrine status and spermatogenesis. The study was 7-9 years retrospective and it is therefore impossible to infer what the immediate effects of the radiation exposure were on these parameters.