Development of new methods of investigation modified the approaches to epidemiological analysis of diseases associated with iodine deficiency. Iodine deficiency was evaluated by the level of iodine in environmental objects, while iodine consumption by man was neglected. Today it is recommended to measure urinary iodine excretion Instead of measuring it in water and soil. More than 80% iodine is excreted through the kidneys, and therefore, iodine concentration in the urine reflects its consumption with food. This method of evaluating iodine deficiency has not been used in Russia before.

We evaluated the prevalence of iodine deficiency in Russia, tried a method for measuring urinary iodine concentrations, and introduced it into practice. Iodine was measured in a portion of urine by the cerium arsenite method.

Studies were carried out in 10853 children in 25 regions of Russia. Iodine deficiency of different severity was detected in all regions. Actual iodine consumption by children is 40—80 mcg/day, while the WHO-approved norm is 150 mcg/day. The lowest iodine concentrations were observed in the rural residents (30— 58 mcg/liter); in the urban residents the median of iodine concentration was higher (50—78 mcg/liter, vs. the norm — 100 mcg/liter).

Iodine deficiency was more expressed in Eastern regions of Russia, where medium iodine deficiency predominated (30—52 mcg/liter), and in some regions severe iodine deficiency (16—20 mcg/liter) was observed. Regular intake of 100 mcg potassium iodide normalized the median of iodine concentration in the urine and notably reduced the number of children with low urinary iodine concentrations.

The paper presents clinicomorphological characteristics of follicular tumors of the thyroid in young persons exposed to low-dose radiation after the Chernobyl accident. Follicular thyroid adenomas were more frequent (89.4%) and follicular cancer less so. Most of the patients were females (89.4%). No correlations were found between morphological structure of the tumors, symptoms, tumor size and thickness of the capsule. Radiodiagnosis showed that the majority of tumors (63.9%) were "cold". 14.9% of cases had multinodular thyroid lesions. Oxyphilic cell composition of the tumor was registered in 14.9% patients. Formation of papillary structures took place in 52.4% of the follicular adenomas. Epidemiological and molecular-genetic studies should be performed to elucidate the role of the radiation factor in induction of morphological changes in thyroid tissue.

The disease history, levels of ТЗ, T4, ТТН were investigated and thyroid ultrasonography was made in 111 patients with diffuse toxic goiter (DTG) admitted to hospital in 1984—1993. Of them, '83 had primary DTG, 28 had recurrent thyrotoxicosis. The diagnosis was made in 1978—1993, the treatment was performed in different medical institutions according to the patients ’ residence. The analysis showed that endocrinologists of different clinics practice different policy of thyrostatic treatment (different initial doses of the drugs, different duration of their administration). Out of 98 patients treated with mercasolil recurrence arose in 68%, persistent euthyrosis in 35%, hypothyroidism in 2%>. It is demonstrated that outcome of the conservative treatment does not depend on the initial dose of mercasolil or adjuvant levo-thyroxine but solely on the duration of continuous treatment. After 52 operations recurrences occurred in 35%, hypothyroidism in 36%, euthyrosis in 29%. Recurrent thyrotoxicosis developed as a rule within a year after thyrostatic treatment (84%) and within 5 years after operation (94%).

A 4-year neonatal screening for infantile hypothyroidism (IH) performed in the Moscow Region in 1995—1998 under relevant Federal program has detected 29 neonates with IH. The cases distribution in the Region was sporadic with the mean frequency of 1:6286. By the incidence of retesting, 53 districts of Moscow region were grouped into 3 groups (Pl, P2, P3), differing by the functional activity of the thyroid. The incidence of retests was significantly higher in P3 region vs. P2 and P3 regions (РЗ > P2 > P3) and correlated with the incidence of transitory hypothyrosis and published data on high level of technogenic pollution of the territories, and presence of markers of ecology-related diseases. Epidemiological values of neonatal screening for congenital hypothyrosis indicate that iodine deficiency in the Moscow region can be regarded as characteristic moderately severe.

Plasma and erythrocyte concentrations of lipid acyl hydroperoxides, malonic dialdehyde (MDA), and a-tocopherol were measured in 45patients with diffuse toxic goiter (DTG) before and after thyrostatic therapy and in 26 of these patients 3—6 months after subtotal resection of the thyroid in a state of euthyrosis. The initial link in lipid peroxidation (LPO) was activated in erythrocytes and plasma in hyperthyrosis, while toxic LPO product MDA accumulated only in the plasma. The level of one ofpotent antioxidants a-tocopherol was decreased at all stages of examination in erythrocytes, while in the plasma it was decreased only before therapy. Estimation of the Horvitt index and LPO-antioxidant defense conjugation index (a-tocopherol requirement, content, or insufficiency) in the plasma and erythrocytes showed decreased content of vitamin E in tissues of patients with DTG, which recommends antioxidant therapy to DTG patients.

Vascular complications of diabetes are the main cause of disability and mortality. That is why the efforts of numerous scientific laboratories and scientists are aimed at elucidating the mechanisms of the pathogenesis of these disorders.

The results of many studies, and in particular, DCCT (The Diabetes Control and Complication Trial) indicate that hyperglycemia is one of the main causes of the development of late vascular complications of diabetes. Chronic hyperglycemia initiates the development of changes in the vascular wall using several mechanisms: by activating the polyol pathway of glucose metabolism, glycosylation of various proteins, oxidative stress, etc.

There are few observations in the literature that indicate an increased frequency of thyroid nodular pathology (thyroid gland) with total hypercorticism syndrome [3,6, 8-13, 15-17]. According to some reports, palpable formations and nodular changes in ultrasound of this organ are found in patients with Itsenko-Cushing's disease 2.5-3 times more often than in the population (10% versus 4% [14] and 60% versus 20% [7 ] respectively). Moreover, in clinically similar cases of the combination "thyroid gland + hypercorticism", the morphological nature of the pathology of the thyroid and pituitary-adrenal system is characterized by pronounced polymorphism.

In clinical practice, the greatest difficulties for diagnosis are polyendocrinopathies. Of these, polyendocrine syndromes are the least studied, in which the functions of several peripheral endocrine glands are initially impaired. The main cause of this pathology are autoimmune lesions [5, 6].

То prove the hypothesis that onset of hyperthyroidism may be attributed not only to hyperactivity of beta-adrenergic system but also to enhanced endothelial impacts on the tone of smooth muscle cells, the authors studied the role of endothelium in regulation of functional activity of arterial vessels in hypothyroidism. The experiments were made on isolated aortic segments of euthyroid and hyperthyroid female rats. Contractile and endothelium-dependent dilatations of the aortic segments in response to noradrenaline and carbacholine, respectively, were studied. It was shown that in hyperthyroidism contractile reactions of the aorta to noradrenalin are less expressed as a result of low sensitivity of the smooth muscle cells to this agonist and strong inhibitory effect of endothelium on these reactions. Dilatatory endothelium-dependent reactions of the isolated aorta in hyperthyroidism are more expressed. Enhancement of carbacholine dilatotory effects may be due to endothelial hyperpolarising factor, whose eficiency grows with a thyroxin-stimulated rise in the number of units of the Na*K*A TPase pump. The findings indicate an essential role of endothelium in mechanisms of hyperthyroid circulatory disorders.

The effects of vitamin E (VE) on early-stage diabetic nephropathy were studied in experimental insulin-dependent diabetes mellitus. Absolute insulin deficiency was modelled with an intravenous injection of ditisone to male rabbits (35 mg/kg). Vitamin E (tocoferoli acetatas) was given orally as gelatin capsules, 100 mg per animal daily for 2 months. VE-fed rabbits exhibited a significant lowering of basal hyperglycemia, rise of basal insulinemia, and better glucose tolerance than diabetic control. VE also normalized ditisone-increased level of cholesterol, beta-lipoproteins and reduced concentrations of dienic conjugates in blood serum of the diabetic animals. Angioprotective effect of VE manifesting in lowering of microalbuminuria, mass of the kidney and thickness of basal glomerular membrane validates the efficiency of VE in prevention or attenuation of clinical nephropathy in patients with diabetes mellitus.

Jahangir Khakimovich Khamidov (on the occasion of his 70th birthday)

Stefan Makarovich Pavlenko (on the occasion of the 100th anniversary of his birth)