BACKGROUND: There are no large-scale epidemiological studies on primary hyperparathyroidism (PHPT) in Russia. The high prevalence of the disease, the high risk of disability and death in this cohort of patients requires the study of the epidemiological and clinical structure of PHPT to determine the extent of medical care. AIM: Evaluate the frequency of PHPT detection and characterize its clinical forms in Russia using an online registry. METHODS: The object of the study is the database of the State Register of Patients with PHPT 1914 patients from 71 regions of the Russian Federation. New cases of the disease, as well as dynamic indicators are recorded when patients visit outpatient clinics or medical institutions. The analysis of data made at the end of December 2017 was carried out. The following parameters were evaluated: demographic and clinical indicators; indicators of phosphorus-calcium metabolism, the main forms of PHPT and its course, the primary characteristic of PHPT in hereditary syndromes and parathyroid carcinoma. Results are presented as mean and standard deviations, or medians and quartiles; descriptive statistics of qualitative attributes absolute and relative frequencies. RESULTS: the total number of patients with PHPT in the registry on 31 of December 2017 was 1914 cases (0.001% of the population of the Russian Federation). Identification of PHPT was 1.3 cases per 100 thousand of the population in Russia, 7.6 cases in Moscow, 6.1 cases per 100 thousand in the Moscow region. The average age of patients at the time of diagnosis was 55.6 10 years. The active phase of the disease was registered in 84.6% of patients (1620/1914), most of whom had a symptomatic PHPT 67.1% (1087/1620), and 32.9% a asymptomatic disease (533/1620). Symptomatic disease with visceral complications was detected in 15.8% cases (172/1087), with bone complications in 48.4% (526/1087). The mixed form of the disease was detected in 35.8% of patients with manifest form (389/1087). Normocalcemic variant PHPT (nPHPT) was registered in 14.5% cases (234/1620). Sporadic PHPT occurs in 83% of cases (1592/1914). 326 patients (17%) had a suspicion for hereditary form of the disease: average age was 31.2 12.3 years. A genetic analysis was conducted in 61 patients (3.2%): showed the mutation in the MEN1 gene in 2.9% of cases (55/1914) and the mutation in the CDC73 gene in 0.3% of cases (6/1914) (HPT-JT syndrome). Parathyroid carcinoma was confirmed in 1.8% of all patients (35/1914). Surgical treatment was performed in 64.5% of patients (1234/1914). Remission was achieved in 94% of cases (1160/1234), in 6% of cases relapse after surgical treatment or persistence of PHPT was recorded. CONCLUSION: detection of PHPT in the Russian Federation raised in comparison to 2016, which is associated with an active start of registration of patients in the regions. At this stage, it is necessary to modify the principles of registration and control, to make a platform for gathering information and calculating the necessary volumes of medical care for PHPT patients.

Мокрышева Наталья Георгиевнад-р мед. наук, руководитель Центра патологии околощитовидных желез 1

IntroductionChronic hypoparathyroidism is a relatively rare disease associated with multicomponent medical therapy and various complications. The analysis of large databases of patients with chronic hypoparathyroidism is a necessary tool to enhance quality of medical care, as well as to determine the optimal clinical and therapeutic approaches, and prognostic markers of the disease.The Aimof this study is to estimate the clinical and biochemical profile, long-term complications, medical therapy and disease control of the patients with chronic postsurgical and non-surgical hypoparathyroidism.Materials and Methodsthe cross-sectional, observational, continuous study was based on the Russian Registry of patients with hypoparathyroidism. 544 patients from 63 regions of the Russian Federation were included in this study.ResultsThe majority of cases had postsurgical etiology (88.4%). Postsurgical hypoparathyroidism prevailed in females (р<0.001). About a half of patients had blood calcium and phosphorus targets, 56 and 52% respectively. Nephrolithiasis was confirmed in 32.5%, nephrocalcinosis - in 12.3% of cases. The risk of nephrocalcinosis/nephrolithiasis increased by 1.85 times with disease duration more than 4.5 years. The cataract was found in 9.4%. The cut-off point for the development of cataracts was 9.5 years, with a 6.96-fold increased risk. The longer duration of hypoparathyroidism of any etiology was associated with more frequent cataract (p=0.0018).We found brain calcification in 4%, arrhythmias in 7.2% and neuropsychiatric symptoms in 5.15% of cases. Generally, the BMD in the studied group corresponded to age values, and there was no evidence for the phenomenon of high bone density. TBS was consistent with normal bone microarchitectonics. In our study, the majority of patients (83.5%) was treated with standard therapy of calcium and vitamin D supplements. 5 patients with severe disease course were treated with rhPTH (1–34).ConclusionsAnalysis of the presented database indicates insufficient diagnosis of the complications associated with chronic hypoparathyroidism. Overall, hypoparathyroidism is associated with higher risks of renal stone formation, decreased GFR, cataract especially in patients with longer duration of disease.

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The viscosity properties of melts of fibre-forming polypropylene (PP) and poly(butylene terephthalate) blends were investigated in the entire range of ratios at different stresses and shear rate gradients at 230-250°C. It was shown that melts of fibre-forming PP and PBT blends are weakly crosslinked systems. The effect of the mass ratio of PP and PBT on the apparent activation energy of viscous flow of melts of the blends was investigated at different shear stresses and shear rate gradients. It was hypothesized that this blend can be assigned to the group of limitedly compatible systems. The probability of compatibility of the polymers in the melt appears when up to 20% PBT is incorporated in the PP. The blends are not compatible for the remaining ratios of polymers in the investigated system.We know that the performance properties of articles made of polymer blends are determined to a significant degree by the mutual dispersion of the components. The complete (thermodynamic) compatibility of film-and fibre-forming polymers in a melt is a somewhat rare exception. The possibility of spontaneous molecular mixing of different macromolecules (their mutual solubility) is due to both the enthalpic and the entropic aspects of the process of attaining the equilibrium state [1].The important amount of accumulated experimental and theoretical data indicates the validity of the statement that the relaxation (and consequently structural-mechanical) characteristics of polymers in the viscous-flow and solid states are somewhat close. This is due to the cooperativity of deformation processes on the supramolecular level [2, 3], which substantiates the approach to predicting the possibility of combining different linear polymers in the solid state based on the results of studying the temperature dependence of the viscosity of melts of polymer blends in the entire range of ratios of components (naturally, outside of the binodal phase boundary). It is evident that the compatibility (mutual solubility) of polymers both in the solid state and in melts is determined by the same thermodynamic factors as the mutual solubility of low-molecular-weight compounds, but their primary structure and the flexibility of linear macromolecules must be taken into consideration [3], since molecular mixing can only be realized on the segmental level.According to the FloryScott concept [4], the thermodynamic compatibility of polymers in the solid state can be predicted with some degree of probability by comparing the solubility parameters of the components of the blend: (δ s.1 δ s.1 ) = = Δδ ≤ 1.5 (cal⋅cm -3 ) 0.5 ≡ 3075 (J⋅m -3 ) 0.5 , where the solubility parameters δ p.i of the miscible polymers can be validly estimated with the Askadskii method [5]:, 1