[The role of immunohistochemical examination in the differential diagnosis of atypical tumors and carcinomas of parathyroid glands]. / Rol' immunogistokhimicheskogo analiza v differentsial'noi diagnostike atipicheskikh opukholei i kartsinom okoloshchitovidnykh zhelez.

Differential diagnosis of atypical parathyroid tumors (APT) and parathyroid carcinomas (PC) is important in determining further management and prognosis. Morphologic diagnosis is sometimes difficult, in which case it is supplemented by immunohistochemical (IHC) examination. OBJECTIVE: Studying the role of IHC analysis in the differential diagnosis of APT and PC. MATERIAL AND METHODS: The study included 44 patients with morphologic diagnosis of the APT established after surgical treatment for primary hyperparathyroidism on the basis of Endocrinology Research Centre during 2018-2023. All cases underwent IHC examination with evaluation of CD31/CD34 and parathormone (PTH) expression for identification of vascular invasion, Ki-67, parafibromin. RESULTS: According to the results of IHC analysis in 8/44 patients (18.2%) the diagnosis of APT was revised in favor of the PC: in 7 of them vascular invasion was detected; in 1 patient the additional series of slices in the surrounding fatty tissue revealed foci of tumor growth, confirmed by positive reaction with antibodies to PTH. According to IHC results, the material was divided into 2 groups: APT and PC. There were no differences in clinical and morphological characteristics, Ki-67% level and parafibromin expression between the groups. CONCLUSION: Assessment of clinical and laboratory-instrumental data at the preoperative stage does not allow differentiating APT from PC. In case of APT diagnosis and detection of suspicious morphological features, it is necessary to perform IHC examination to exclude PC.

[The algorithm for morphological assessment of malignant potential of adrenocortical tumors using mathematical modeling method]. / Algoritm morfologicheskoi otsenki zlokachestvennogo potentsiala adrenokortikal'nykh opukholei s ispol'zovaniem metoda matematicheskogo modelirovaniya.

OBJECTIVE: To develop the mathematical model with high sensitivity and specificity to assess the malignant potential of adrenal cortical tumors, which can be used to diagnose adrenocortical carcinoma (ACC) in adults. MATERIAL AND METHODS: Pathomorphological examination of surgical and consultative material of adrenocortical neoplasms was carried out. All cases were verified according to the WHO Classification of adrenal gland tumors (5th ed., 2022), the tumor's histogenesis was confirmed by immunohistochemical examination. Statistical analysis of the histological and immunohistochemical factors in terms of their value in relation to the diagnosis of ACC was carried out on Python 3.1 in the Google Colab environment. ROC analysis was used to identify critical values of predictors. The cut-off point was selected according to the Youden`s index. Logistic regression analysis using l1-regularisation was performed. To validate the model, the initial sample was divided into training and test groups in the ratio of 9:1, respectively. RESULTS: The study included 143 patients divided into training (128 patients) and test (15 patients) samples. A prognostic algorithm was developed, which represent a diagnostically significant set of indicators of the currently used Weiss scale. The diagnosis is carried out in 3 stages. This mathematical model showed 100% accuracy (95% CI: 96-100%) on the training and test samples. CONCLUSION: The developed algorithm could solve the problem of subjectivity and complexity in the interpretation of some of the criteria of current diagnostic algorithms. The new model is unique in that, unlike others, it allows verification of all morphological variants of ACC.

[Diabetes mellitus type 2: National Russian guidelines vs real clinical practice].

According to the "Federal Law on the Fundamentals of Protection of the Public Health", medical care for patients should be provided in accordance with National Russian guidelines for the relevant nosology, which are based on the principles of evidence-based medicine. The article presents an analysis of the compliance with the completeness of implementation of National Russian guidelines in the treatment of patients with type 2 diabetes mellitus (DM 2) in real clinical practice. The analysis of the actual state of management of DM 2 patients was carried out from the Federal Register of diabetes as of 01.01.2023. Incomplete compliance with the guidelines on the frequency of measuring glycated hemoglobin, the rate of intensification of hypoglycemic therapy, and the appointment of new classes of hypoglycemic drugs was established. Possible reasons for the identified discrepancies between real practice and guidelines requirements are discussed, as well as possible measures to overcome these discrepancies.

[Clinical importance of evaluation of circulating miRNA expression and epicardial adipose tissue thickness as predictors of cardiovascular pathology in young patients with type 1 diabetes mellitus].

Cardiovascular disease (CVD) in type 1 diabetes mellitus (T1DM) is preceded by asymptomatic changes in the geometry of the heart. The only symptoms of the beginning of cardiac remodeling and concomitant predictors of an unfavorable cardiovascular prognosis are: thickening of epicardial fat (EAT), secreting a number of adipokines, and cardiospecific miRNAs. To improve the effectiveness of prevention of CVD in young patients with DM1, a search was made for structural-functional and epigenetic markers. AIM: To assess the state of the cardiovascular system according to MRI-heart with T1 mapping in T1DM without CVD. To reveal the relationship of epigenetic markers (circulating miR-126-5p, miR-21-5p) and adipokines with cardiovascular system in T1DM. Suggested personalized approach to patients with T1DM with initial manifestations of joint remodeling and/or exclusion of cardiospecific microRNA. MATERIALS AND METHODS: The study included 40 patients: 30 with T1DM (age 26.2±7.4 years), 10 without T1DM (26.4±8.2). The patients underwent a general clinical examination, bioimpedancemetry, electrocardiography, MRI of the heart with T1 mapping, determination of adiponectin, resistin, visfatin, NT-proBNP, miR-126-5p, miR-21-5p. RESULTS: Patients with T1DM had lower levels of cardioprotective miR-126-5p (p=0.046). According to MRI of the heart in T1DM, signs of vascular remodeling were revealed - thickening of the interventricular septum (p=0.001), posterior wall (p=0.012) and relative size of the walls (p=0.048) of the left ventricle, an increase in EAT density (p=0.001). Diffuse vascular fibrosis was found in 16% of patients from the T1DM group. Also, in T1DM, the expression of visfatin is increased (p=0.036) and adiponectin is reduced (p=0.043). CONCLUSION: Structural and functional changes in the cardiovascular system (including thickening of the EAT), shifts in miR-126-5p expression and adipokines profile are observed already at a young age in patients with T1DM. In T1DM, diffuse vascular fibrosis is detected in 16% of patients. The data obtained were used to identify the group increased risk of developing CVD in T1DM and served as the basis for determining the timing of the start of preventive therapy.

[Adipokines and the cardiorespiratory system in young patients with type 1 diabetes mellitus].

Early screening of complications of diabetes mellitus (DM) is one of the priorities for public health. Most patients with type 1 diabetes mellitus (T1DM) are patients of working age. New strategies for the primary prevention of cardiovascular disease (CVD) are needed to prevent their early disability. AIM: To assess the predictive value of adipokines in relation to a personalized approach to the need for an in-depth examination of young patients with T1DM. MATERIALS AND METHODS: The study included 98 patients without CVD: 70 patients with T1DM (mean age 26.4±8.1 years) and 28 patients without DM (mean age 27±9 years). All patients underwent a general clinical examination, the levels of adipokines were determined, ergospirometry, echocardiography, and bioimpedancemetry were performed. RESULTS: Changes in the cardiorespiratory system in patients with T1DM were revealed, in comparison with persons without T1DM: anaerobic threshold was reached faster (p=0.001), maximum oxygen consumption was lower (p=0.048), metabolic equivalent was reduced (p=0.0001). Signs of myocardial remodeling were found in the T1DM group: there was an increase in the relative wall thickness (p=0.001), the posterior wall of the left ventricle (p=0.001), myocardial mass index (p=0.049), in comparison with persons without T1DM. Changes in the adipokines system were revealed: higher levels of resistin (p=0.002) and visfatin (p=0.001), lower level of adiponectin (p=0.040) in T1DM. A positive correlation was found between posterior wall of the left ventricle and visfatin (p=0.014) and a negative relationship between adiponectin and relative wall thickness (p=0.018) in T1DM. CONCLUSION: In T1DM, even at a young age, there are multifactorial changes in the heart, which can be detected even at the preclinical stage. The data obtained can be used to identify groups of patients at high risk of developing dangerous CVD in T1DM, which can form the basis for determining the timing of the start of preventive therapy.

[Modern problems of hyper- and hypoparathyroidism].

The parathyroid glands are the most important regulators of mineral metabolism. The parathyroid glands were first discovered only in 1880 and their function went the long way unrecognized. Even the term "parathyroid gland" itself speaks of the initial misconception of it as an underdeveloped part of the thyroid. To date, there is a large amount of data regarding the role of this endocrine gland in the human body and the significant changes associated with their dysfunction, including such widespread diseases such primary, secondary and tertiary hyperparathyroidism, hypoparathyroidism. This review covers the problem of the main disturbances in calcium-phosphorus metabolism, presents the results of databases of patients with primary hyperparathyroidism and hypoparathyroidism, as well as current epidemiological trends in Russia and in the world.

[Mineral metabolism and COVID-19: is there a connection?]

Due to global spread of COVID-19, the search for new factors that could influence its clinical course becomes highly important. This review summarize the relevant publications on the association between immune system and the main regulators of mineral homeostasis including. In addition, we have highlighted the various aspects of phosphorus-calcium metabolism related to the acute respiratory diseases and in particular to COVID-19. The data about the calcium-phosphorus metabolism in SARS-CoV-2 infection is required to understand the possible clinical implications and to develop new therapeutic and preventive interventions.

[Neuroendocrine markers in parathyroid tumors]. / Neiroendokrinnye markery v opukholyakh okoloshchitovidnykh zhelez.

The parathyroid glands (PTGs) are a key regulator of calcium and phosphorus metabolism in the human body. In terms of their, morphological and immunophenotypic characteristics, PTGs are neuroendocrine organs, and their neoplasms are neuroendocrine tumors. These neoplasms include adenoma and cancer; in addition, glandular hyperplasia may develop, which is most characteristic of multiple endocrine neoplasia (MEN1, MEN2a, and MEN4) syndromes. The morphological characteristics of pathologically altered PTGs in MEN syndromes are variable. The analysis and generalization of knowledge about the features and expression of various immunohistochemical markers in PTG tissue in health and in diseases are useful in the practical work of not only pathologists, but also clinicians of various specialties.

[The role of vitamin D in seasonal acute respiratory viral infections and COVID-19].

A link between vitamin D deficiency and susceptibility to infectious diseases was suggested over a hundred years ago. Epidemiological studies show a strong association between seasonal fluctuations in vitamin D levels and the incidence of various infectious diseases, including septic shock, acute respiratory infections, and influenza. Our understanding of vitamin D metabolism and its extra-skeletal functions has improved significantly over the past three decades, and the discovery that the vitamin D receptor and 1a-hydroxylase, an enzyme needed to convert vitamin D to its active form, is present in the cells of the immune system, revolutionized in this area. Recent studies have shown that vitamin D regulates the expression of specific endogenous antimicrobial peptides in immune cells, modulates the immune response and the course of autoimmune processes; these actions indicate the potential role of vitamin D in modulating the immune response to various infectious diseases. This publication reviews the literature on the effects of vitamin D on immunity, its potential in the prevention and treatment of viral diseases, with a particular focus on COVID-19.

[Dynamic changes of renin-angiotensin-aldosterone system parameters after surgery of primary hyperparathyroidism].

AIM: To study an activity of the Renin-Angiotensin-Aldosterone System (RAAS) components in patients with primary hyperparathyroidism (PHPT) before and after parathyroidectomy (PTE). MATERIALS AND METHODS: A comparative study of patients with PHPT and control group. The first stage of the study included 56 patients with PHPT (group 1) before and on the third day after PTE. The second stage was carried out in 27 patients with remission of PHPT (group 2). All patients and healthy volunteers were tested for the main parameters of phosphorus-calcium metabolism and the RAAS parameters (plasma renin activity PRA, serum aldosterone, angiotensin II AT II). RESULTS: Patients with active PHPT demonstrated changes in RAAS activity (lower PRA, higher AT II level) comparing to control group, that have statistical significance in group 1 (p0.001 for both parameters). There were no significant differences in aldosterone levels (p1=0.090;p2=0.140). On the third day after PTE (group 1), a decrease in aldosterone level (p=0.009) and a tendency to decrease in PRA (p=0.030) were detected. However, an increase in PRA (p=0.018), a decrease in AT II concentration (p=0.032) comparing to the initial values and their normalization were observed 12 months after surgery when permanent normal serum calcium and PTH levels had been achieved. There were controversial correlations between the parameters of phosphorus-calcium metabolism and RAAS. The influence of angiotensin-converting-enzyme inhibitors and AT II receptor blockers on phosphorus-calcium metabolism in patients with PHPT was not observed. CONCLUSION: In patients with PHPT, there were no сlear correlations of phosphorus-calcium metabolism parameters with RAAS, however an increase of AT II concentration was noted, that can take part in a development of hypertension for this endocrinopathy. PTE can have a positive effect on AT II level.

[Morphofunctional features of non-functioning pituitary adenomas]. / Morfofunktsional'nye osobennosti gormonal'no-neaktivnykh adenom gipofiza.

Non-functioning pituitary adenomas (NFPAs) account for about 30% of all pituitary tumors. NFPAs are characterized by the lack of secretory potential or its weak expression insufficient for determination of the blood level of adenohypophyseal tropic hormones and for development of a specific clinical picture. Morphologically, NFPAs are a heterogeneous group of tumors, the classification of which was previously based only on immunoreactivity for pituitary tropic hormones. The WHO revised its Classification of Tumors of Endocrine Organs (4th edition) in 2017. The main changes relate to adenohypophysial-cell lineage for the designation of adenomas into subtypes. The introduction of transcription factor antibodies has become a fundamentally new approach to the classification of NFPAs, which is necessary to recognize less differentiated tumor types. This paper provides information on the new histopathological classification of pituitary adenomas, on the theories of silent adenomas, and on the proliferative and prognostic markers of NFPAs.

[Clinical and morphological characteristics of parathyroid carcinoma]. / Kliniko-morfologicheskaia kharakteristika raka okoloshchitovidnoi zhelezy.

Parathyroid carcinoma (PTC) is a rare malignant tumor with the clinical manifestation of hyperparathyroidism, reliable morphological signs of invasive growth, and poor clinical prognosis. The differential diagnosis of PTC due to the rarity of this pathology, not always explicit morphological criteria, and the lack of a certain immunohistochemical panel is complex and needs further clarification. The paper summarizes an update on the clinical and morphological characteristics of PTC.

Vitamin D: effects on pregnancy, maternal, fetal and postnatal outcomes.

A high prevalence of vitamin D deficiency and its negative consequences for health is identified as area of primary concern for scientists and clinicians worldwide. Vitamin D deficiency affects not only bone health but many socially significant acute and chronic diseases. Observational studies support that pregnant and lactating women, children and teenagers represent the high risk groups for developing vitamin D deficiency. Current evidence highlights a crucial role of vitamin D in providing the fetal life-support system and fetus development, including implantation, placental formation, intra- and postpartum periods. Hypovitaminosis D during pregnancy is associated with a higher incidence of placental insufficiency, spontaneous abortions and preterm birth, preeclampsia, gestational diabetes, impaired fetal and childhood growth, increased risk of autoimmune diseases for offsprings. Potential mechanisms for the observed associations contain metabolic, immunomodulatory and antiinflammatory effects of vitamin D. Epigenetic modifications in vitamin D-associated genes and fetal programming are of particular interest. The concept of preventing vitamin D deficiency is actively discussed, including supplementation in different ethnic groups, required doses, time of initiation and therapy duration, influence on gestation and childbirth. An adequate supply of vitamin D during pregnancy improves the maternal and fetal outcomes, short and long term health of the offspring. Still current data on relationship between maternal vitamin D status and pregnancy outcomes remains controversial. The large observational and interventional randomized control trials are required to create evidence-based guidelines for the supplementation of vitamin D in pregnant and lactating women.

[Recombinant human parathyroid hormone in the therapy of hypoparathyroidism]. / Rekombinantnyi paratireoidnyi gormon cheloveka v terapii gipoparatireoza.

Hypoparathyroidism is an endocrine disease that results from deficiency or complete absence of parathyroid hormone (PTH), a biologically active 84-amino acid polypeptide. Standard therapy for chronic hypoparathyroidism includes oral calcium salts and active vitamin D metabolites and is aimed at maintaining a balance between optimal near-normal serum calcium concentration and normocalcuria. Traditional treatment regimens not always lead to the compensation for calcium and phosphorus metabolism. Until recently, hypoparathyroidism is the only endocrine disorder that has not been treated with the recombinant hormone. To date, two recombinant PTH forms have been synthesized, which can be used as pathogenetic therapy for hypoparathyroidism. This review is dedicated to replacement therapy for hypoparathyroidism, by using both the full-length PTH molecule (1-84) and its shorter, but fully active, PTH form (1-34). This review considers stages in the developmental of hormone replacement therapy for hypoparathyroidism, discusses the most rational dosing regimens, and compares their efficacy and safety, as well as prospects for the development of this area.

[Calciuria as a metabolic marker for various conditions and diseases].

The article analyzes the literature on the features of human calcium homeostasis. The authors describe the etiopathogenetic role of calcitropic hormones, the plasma and urine acid-base status, various ions, lifestyle and nutrition and other factors contributing to hypercalciuria due to increased intestinal absorption, bone resorption, impairment of tubular calcium reabsorption, etc. They discuss the role of calciuria as a factor in forming urinary calculi and present their own observations.

[Benign paroxysmal positional vertigo: modern concepts of its etiology and pathogenesis]. / Dobrokachestvennoe paroksizmal'noe pozitsionnoe golovokruzhenie: sovremennye predstavleniia ob étiologii i patogeneze.

The objective of the present review of the literature is the analysis of the currently available data concerning etiology and pathogenesis of benign paroxysmal positional vertigo (BPPV). The special emphasis is placed on the modern hypotheses of BPPV formation that collectively account for not more than 15% of all known cases of this condition. The best explored are the following causes of benign paroxysmal positional vertigo: vestibular neuronitis, head injuries, and disorders in the middle ear. During the recent years, much attention has been given to the role of disturbances of calcium metabolism and osteoporosis in etiology of benign paroxysmal positional vertigo. It is supposed that pathogenesis of vertiginous attacks can be explained in terms of the canalolithiasis and cupulolithiasis theories.

[CDC73 mutations in young patients with primary hyperparathyroidism: A description of two clinical cases]. / Mutatsii v gene CDC73 u molodykh patsientok s pervichnym giperparatireozom (opisanie dvukh klinicheskikh sluchaev).

The article describes two clinical cases of severe primary hyperparathyroidism (PHPT) caused by parathyroid carcinoma in young female patients who underwent molecular genetic testing to rule out the hereditary forms of PHPT. In both patients, heterozygous germline nonsense mutations of tumor suppressor gene CDC73 encoding parafibromin (p.R91X and p.Q166X) were identified using next-generation sequencing with Ion Torrent Personal Genome Machine (Thermo Fisher Scientific - Life Technologies, USA). It is the first description of CDC73 mutations in Russia, one of the mutations is described for the first time in the world. Identification of germline mutations in the CDC73 gene in patients with PHPT necessitates regular lifelong screening for other manifestations of hyperparathyroidism-jaw tumor syndrome (HPT-JT), PHPT recurrence due to parathyroid carcinoma as well, and identification of mutation carriers among first-degree relatives.

[Multiple endocrine neoplasia type 1 syndrome with three classical components and chiasm glioma: specific features of target organ lesions and a clinical observation].

The article briefly reviews the specific features of target-organ lesions in multiple endocrine neoplasia type 1 (MEN1) syndrome and a clinical case of genetically confirmed MEN1 syndrome in a young female patient. Despite the relative rarity of this disease, timely diagnosis, treatment and screening for its main components are very important for the overall prognosis of patients with MEN1 and their first-degree relatives who are MEN1 gene mutation carriers. The described case is noteworthy for a number of specific features. The authors could find no account of optic chiasm glioma within the framework of MEN1 in the literature. Moreover, therapy-resistant somatoprolactinoma engages attention, which points to its aggressive nature with pituitary adenoma that is not been clearly visualized on magnetic resonance imaging. Of interest is the order of detection of neoplasms, in particular the manifestation of hypoglycemic episodes as a sign of organic hyperinsulinism. which have been initially regarded as epileptic seizures, after the use of sustained-release somatostatin analogues for the treatment of acromegaly.

[TYPE 1 MULTIPLE ENDOCRINE NEOPLASIA SYNDROME AND FAMILIAL ISOLATED HYPERPARATHYROIDISM].

Type 1 multiple endocrine neoplasia syndrome (MEN-1) is a rare autosomal dominant disorder caused by mutation in the MEN-1 gene and manifest as a combination of tumours of parathyroid glands, endocrine pancreas, and adenohypophysis. Familial isolated hyperparathyroidism (FIHP) is another rare autosomal dominant disorder characterized by the development ofparathyroid tumours as the sole endocrinopathy within a single family. The notion of FIHP encompasses different hereditary forms of primary hyperparathyroidism, such as a variant of MEN-1 syndrome. This paper is a brief literature review of the problems related to primary hyperparathyroidism, MEN-1, and FIHP. Also, It describes a family presenting with genetically confirmed MEN-1 syndrome, manifest as primary hyperparathyroidism.

[Multiple endocrine neoplasia type 1 variants and phenocopies].

Multiple endocrine neoplasia type 1 (MEN1) is a rare autosomal dominant hereditary disease due to a mutation in the MENI tumor suppressor gene. The risk of the disease in first-degree relatives of MEN1 mutation carriers is 50%. MENI gene mutations are not identified in 10-30% of familiar MEN1 patients and in 60-80% of sporadic MEN1 cases, which can be explained by mutations in the noncoding regions of the MEN1 gene, large gene deletions or mutations in other yet unknown genes. Molecular genetic testing can exclude the diagnosis of MEN1 in patients who do not harbor the MEN1 mutation, thus revealing a MEN1 phenocopy. This obviates the need for annual screening for the early detection of other remaining components of the disease and its risk in progeny.