МЕТОДИКА ОБРАБОТКИ ЭКСПЕРИМЕНТАЛЬНЫХ ДАННЫХ ПРИ МОДЕЛИРОВАНИИ ДИСПЕРСИИ ИМПЕДАНСА БИОЛОГИЧЕСКИХ ТКАНЕЙ С ПОМОЩЬЮ СХЕМЫ ЗАМЕЩЕНИЯ ФРИКЕ

Purpose. Modeling the dispersion of the biological tissue impedance of vegetable and animal origin using the Fricke equivalent circuit; development of a technique for experimental data processing to determine the approximation coefficients of the dispersion of the biological tissue impedance for this equivalent circuit; study of the features of the equivalent circuit at modeling the dispersion of the impedance, resistance, and reactance; the definition of the frequency domain in which using of the equivalent circuit is correct; revealing and generalization of the main regularities of dissipation of biological tissue impedance of vegetable and animal origin. Methodology. The technique is based on the scientific provisions of theoretical electrical engineering – the theory of the electromagnetic field in nonlinear media in modeling the dispersion of the biological tissue impedance. Results. The electric circuit of the Fricke equivalent circuit allows modeling the dependences of the impedance module of biological tissues, active and reactive components of impedance with acceptable accuracy for practical purposes in the frequency domain from 103 to 106 Hz. The equation of impedance of the Fricke equivalent circuit for biological tissues makes it possible to approximate the frequency dependences of the impedance modulus, active and reactive parts of the total resistance only by using the approximation coefficients corresponding to each part. The developed method for determining the values of the approximation coefficients of the impedance equation for the Fricke equivalent circuit for biological tissues allows to determine these values with high accuracy for various biological tissues. It is shown that the frequency dependences of the active component of the total resistance for tissues of vegetable and animal origin are similar. Originality. The developed technique operates with the normalized values of the impedance modulus of the Fricke equivalent circuit, the active and reactive components of the impedance as a function of frequency, which allows a comparative analysis of the dependencies of these parameters of various biological tissues of plant and animal origin. Practical value. The approximate dependences of the absolute impedance modulus, active and reactive components of the impedance allow modeling processes occurring in biological tissues with the passage of a current of different frequency. Dependence of the impedance of biological tissue can be applied to the design of diagnostic and control equipment to determine the properties of tissues of animal and vegetable origin, including developing more effective medical equipment.Разработана методика обработки экспериментальных данных для определения коэффициентов аппроксимации импеданса биологических тканей растительного и животного происхождения при моделировании дисперсии импеданса с помощью схемы замещения Фрике. Проведен анализ свойств схемы замещения Фрике, ее возможностей и особенностей при моделировании дисперсии импеданса, резистанса и реактанса. Показано, что при нормировании дисперсии активные составляющие импеданса для тканей растительного и животного происхождения подобны

АНАЛИЗ КОНСТРУКЦИЙ ШИХТОВАННЫХ МАГНИТОПРОВОДОВ СИЛОВЫХ ТРЕХФАЗНЫХ ТРАНСФОРМАТОРОВ

Analysis and research into properties and parameters of different-type laminated magnetic cores of three-phase power transformers are conducted. Most of new laminated magnetic core designs are found to have significant shortcomings resulted from design and technological features of their manufacturing. These shortcomings cause increase in ohmic loss in the magnetic core, which eliminates advantages of the new core configurations and makes them uncompetitive as compared with the classical laminated magnetic core design.Проведен анализ и исследование свойств и параметров различных типов шихтованных магнитопроводов силовых трехфазных трансформаторов. Установлено, что большинство новых конструкций шихтованных магнитопроводов, обладают серьезными недостатками, вызванными конструктивными и технологическими особенностями процесса их изготовления. Эти недостатки ведут к увеличению активных потерь в магнитопроводе, что нивелирует их достоинства и не позволяет им конкурировать с классической шихтованной конструкцией магнитопровода.Проведено аналіз та дослідження властивостей й параметрів різних типів шихтованих магнітопроводів силових трифазних трансформаторів. Встановлено, що більшість нових конструкцій шихтованих магнітопроводів мають серйозні недоліками, викликані конструкційними й технологічними особливостями процесу їх виготовлення. Ці недоліки ведуть до збільшення активних втрат у магнітопроводі, що нівелює їх переваги та не дозволяє їм конкурувати із класичною шихтованою конструкцією магнітопроводу

GCK-MODY diabetes course in persons over 18 years of age: prospective observation

Most young patients with hyperglycemia have type 1 diabetes and type 2 diabetes but up to 10% of all cases of the disease occur in MODY (Maturity Onset Diabetes of the Young). Published abstracts show features of the debut, laboratory and genetic characteristics of MODY in the Russian population. However there is a small amount of data on the clinical course of this nosology in the Russian Federation.Aim: To investigate the characteristics of the 3-year course of GCK-MODY diagnosed after 18 years.Materials and methods: 85 probands and 46 relatives of the first and second degrees of kinship with a clinical diagnosis of GCK-MODY were examined: biochemical and hormonal blood tests, ultrasound, molecular genetic studies. Patients were invited for a follow-up visit 3 years after verification of the pathogenic mutations associated with GCK-MODY. Examination, biochemical and hormonalanalyzes , ultrasound were done in second visit.Results: The diagnosis GCK-MODY was verified by a molecular genetic study in 25 probands (29.4%). In 33 of 46 (71.7%) relatives of patients with GCK-MODY were diagnosed identical mutations. In 31 patients with GCK-MODY diagnosed after 18 years, a dynamic observation was performed for three years. Most patients over 18 years of age did not have clinical manifestations of carbohydrate metabolism disorders when diagnosing GCK-MODY and follow up visit. Skin rashes and allergic reactions prevailed among concomitant pathologies. Patients with GCK-MODY had preserved β-cell secretion, HbA1c targets were achieved. Low fasting hyperglycemia prevailed which persisted even after treatment correction. Among the characteristics of carbohydrate metabolism, biochemical, lipid and hormonal parameters during GCK-MODY verification and after three years of observation no significant differences were obtained, which indicates a stable course of the disease. Half of the patients achieved normoglycemia by rational nutrition, two people with GCK-MODY within three years after determining the diagnosis were transferred from insulin therapy to oral glucose-lowering drugs. Among oral glucose-lowering drugs prior to GCK-MODY verification most patients used metformin, 3 years later — dipeptidyl peptidase-4 inhibitors.Conclusion. The results of a three-year follow-up of a group of patients with GCK-MODY demonstrate a non-progressive course of this type of diabetes with stable indicators of carbohydrate metabolism and low fasting hyperglycemia that persists after 3 years of observation. With the verification of GCK-MODY and the achievement of the target values of glycated hemoglobin and postprandial glycaemia by rational nutrition, even if a low level of fasting hyperglycemia is determined, the prescription of oral glucose-lowering drugs is not indicated in most cases

Base mucronutrients and food groups consumption, associations with the risk of fatal cardiovascular disease development in people with type 2 diabetes: a prospective cohort study

Aim. To study the relation between the consumption of the main macronutrients and food groups with the risk of fatal outcomes from cardiovascular diseases (CVD) in people with newly diagnosed diabetes and those who are informed about type 2 diabetes mellitus (T2DM). Material and methods. This prospective analysis included 681 people (284 men and 397 women) with T2DM at baseline HAPIEE (Health, Alcohol and Psychosocial factors In Eastern Europe) 2003 (05) – December 31, 2018 and averaged 14.7 ± 0.7 years. There were 207 incident CV mortality during follow-up period (107 men, 100 women). The questionnaire on the presence of T2DM included information on the awareness of individuals about the presence of T2DM (“Did the doctor tell you that you have T2DM?”). The actual nutrition data included information on the consumption of 147 foods. The hazard ratio was estimated using Cox regression. Results and discussion. In men who aware of T2DM, the risk of developing a fatal CV event decreases with an increase in the consumption of “all-season” fruits (HR 0.413; 95 % confidence interval (CI) 0.234-0.786) and increases with an increase in the consumption of chicken eggs (HR 1.907 95 % CI 1.051-3.437), and alcohol (HR 1.031; 95 % CI 1.001- 1.061). In men who are unaware of T2DM, with an increase in nut consumption, the risk of developing fatal CV events decreases (HR 0.821; 95 % CI 0.679-0.992) and increases with increasing consumption of dairy products (HR 1.105; 95 % CI 1.000-1.221). In women aware of T2DM, consumption of white bread increases the risk (HR 1.489; 95 % CI 1.105-2.004), on the contrary, consumption of black bread reduces the risk of an undesirable outcome (HR 0.575; 95 % CI 0.424-0.818). Conclusions. In men who aware of T2DM, the most significant risk factors were the poor all-season fruits intake and excessive chicken eggs consumption. In women with type 2 diabetes, an increase in white bread consumption is of importance to increasing the risk of an undesirable CV outcome, and an increase in black bread consumption counts for reducing the risk

Тhe prevalence of metabolically healthy obesity: data from the epidemiological survey in of Novosibirsk

Background: Obesity is associated with numerous metabolic complications, such as type 2 diabetes mellitus (DM2), dyslipidemia, arterial hypertension (AH), cardiovascular diseases and some forms of cancer. Nevertheless, the literature describes a group of obese individuals who are more resistant to the development of metabolic disorders. At present, this phenomenon is known as "Metabolically healthy obesity", "metabolically healthy obesity" (MZO). Despite the presence of excess weight or obesity, a favorable metabolic profile can be observed in this cohort of patients, characterized by preserved insulin sensitivity, absence of arterial hypertension, normal lipid, hormonal profile, absence of inflammation and unchanged hepatic transaminases. Aims: To study the prevalence of metabolically healthy obesity (MHO) and its characteristics in men and women at the age of 45–69 years in Novosibirsk. Materials and methods: To study covered 3197 persons from the base of the international project HAPPIE. They had a body mass index (BMI ≥ 30 kg/m²). «Metabolically healthy obesity» was determined as obesity (BMI ≥ 30 kg/m², with 2 and fewer components of metabolic syndrome (MS) by criteria NCEP ATP III, 2001. Statistical analisys SPSS-13. Results: The prevalence of metabolic healthy obesity (MHO) was 42% (38% for men and 43% for women). The examined people with MHO have reliably more favorable average level of TG, HDL-cholesterol, indicators of blood glucose, systolic arterial pressure and diastolic arterial pressure and less waist circumference. In the groups withMHO and MS abdominal obesity is common in men at 95 and 71%, in women at 99 and 90%; hyperTG – in men at 74 and 9%, in women at 72 and 5,5%; lower level HDL-cholesterol in 16 and 1% for men, and in 44,5% and 3% for women; AP in 96 and 77% and 94 and 71% in men and women respectively, the frequency fasting of hyperglycaemia 77 and 21% in men and 60 and 5% in women was markedly different. According to the data obtained by us, the frequency in the sample is high and amounted to 42%. In the subgroup the most commonly found is the MHO phenotype – 53%, than in the men -38%, р <0,001 Conclusions: According to our data, the frequency of metabolic healthy obesity in the sample is high and amounted to 42%. In the female subgroup, a metabolically healthy phenotype is more common 43% than in the male 38%, p <0.001. Metabolically healthy obese individuals are characterized by a significantly lower incidence of fasting hyperglycaemia and dyslipidemia

Diabetes mellitus associated with the mutation of the ABCC8 gene (MODY 12): features of clinical course and therapy

Maturity-Onset Diabetes of the Young (MODY) is a heterogeneous group of diseases associated with genes mutations leading to dysfunction of pancreatic β-cells. Among the 14 identified MODY variants, MODY 1–5 are the most studied. The article reports a MODY 12 clinical case, with mutation in ABCC8, encoding the sulphonylurea receptor. Diabetes mellitus manifested in a 27-year-old man with hyperglycaemia up to 24 mmol/L, without ketosis. Non-proliferative diabetic retinopathy, microalbuminuria, dyslipidaemia and carotid atherosclerosis were revealed upon initial examination. The levels of pancreatic islet cell antibodies and glutamate decarboxylase antibodies were negative, while the level of C-peptide was within the normal range. Insulin therapy in the basal-bolus regimen was provided with a gradual dose reduction due to frequent hypoglycaemia. The preproliferative retinopathy with macular oedema was revealed after 4 months of therapy, and panretinal photocoagulation of both eyes was performed. A molecular genetics study revealed a mutation in the gene ABCC8, the same mutation was found in patient’s mother and uncle. Insulin therapy was cancelled, and the treatment of gliclazide MR 60 mg/day was initiated, which resulted in extreme glycaemic excursions. Thereby, sodium–glucose cotranporter-2 (SGLT2) inhibitor dapagliflozin 10 mg/day was added. A reduction in glucose variability parameters were observed on combination therapy. After 6 months till 1.5 years of treatment, glycaemic control was optimal, no hypoglycaemic episodes were observed. This case study demonstrates clinical features of MODY 12, and the potential of combination of sulfonylurea and SGLT2 inhibitor in the treatment of this disease

The frequency of metabolically healthy and unhealthy phenotypes in women aged 25–44 years with different levels of thyroid-stimulating hormone, prolactin, leptin

Reports that the risk of developing cardiovascular diseases in obesity is not the same, led to the allocation of metabolically healthy and unhealthy phenotypes (MHP and MUHP), this concept is based on the ability of adipose tissue to produce a number of adipokines, one of which is leptin. Hormones such as thyroid-stimulating hormone (TSH) and prolactin (PRL) are interesting from the point of view of their effect on metabolism. Aim of the study was to investigate the prevalence of MHP and MUHP in young women with different body mass index (BMI) and hormonal status (TSH, PRL, leptin) in different phenotypes. Material and methods. A group of women (n = 655) was selected from a representative sample of the Novosibirsk population aged 25–44 to study clinical and laboratory parameters. The design is a cross – sectional, observational, single – centre study. IDF, 2005 and NCEP ATP III, 2001 criteria were used to evaluate the MHP and MUHP. Results and discussion. The prevalence of MUHP in young women in Novosibirsk was 22.3 %, MHP – 77.7 % according to IDF, 2005; according to NCEP ATP III, 2001 – 13.1 and 86.9 %, respectively. The prevalence of MUHP increased with increasing BMI from 4.0 to 72.0 % according to IDF, 2005 and from 2.3 to 58.0 % according to NCEP ATP III, 2001, respectively. In obese women, MUHP was detected twice as often as MHP – 72 and 28 % according to IDF, 2005, 58 and 42 % according to NCEP ATP III, 2001. TSH and PRL do not provide information about metabolic health in young women. Leptin content is associated with BMI. The threshold value of the leptin level was 18.3 ng/ml with maximum sensitivity and specificity (Se = 53.3 %, Sp = 81.5 %), 14.5 ng/ml with equal sensitivity and specificity (Se = 65.7 %, Sp = 65.7 %). The area under ROC curve (AUC) for diagnosis of MUHP was 0.727 (SE = 0.029, p < 0.0001). Conclusion. The frequency of MHP in young women decreases with increasing BMI. MUHP is 3.5 times less common than MHP according to IDF criteria, 2005. TSH and PRL are not associated with the metabolic phenotype in young women. A leptin level more than 18.3 ng/ml has been identified as one of the markers for the recognition of MUHP in women aged 25–44 years, regardless of BMI

A rare splice site mutation in the gene encoding glucokinase/hexokinase 4 in a patient with MODY type 2

The article presents a variant of maturity onset diabetes of the young type 2, caused by a rare mutation in the GCK gene. Maturity onset diabetes of the young (MODY) is a hereditary form of diabetes with an autosomal dominant type of inheritance, an onset at a young age, and a primary defect in pancreatic β-cell function. This type of diabetes is different from classical types of diabetes mellitus (DM1 and DM2) in its clinical course, treatment strategies, and prognosis. Clinical manifestations of MODY are heterogeneous and may vary even among members of the same family, i. e., carriers of identical mutations. This phenotypic variation is due to the interaction of mutations with different genetic backgrounds and the influence of environmental factors (e. g., lifestyle). Using next-generation sequencing technology, the c.580–1G>A substitution (IVS5 –1G>A, rs1554335421) located in an acceptor splice site of intron 5 of the GCK gene was found in a proband. The identified variant cosegregated with a pathological phenotype in the examined family members. The GCK gene encodes glucokinase (hexokinase 4), which catalyzes the first step in a large number of glucose metabolic pathways such as glycolysis. Mutations in this gene are the cause of MODY2. The illness is characterized by an insignificant increase in the fasting glucose level, is a well-controlled disease without medication, and has a low prevalence of micro- and macrovascular complications of diabetes. The presented case of MODY2 reveals the clinical significance of a mutation in the splice site of the GCK gene. When nonclassical diabetes mellitus is being diagnosed in young people and pregnant women, genetic testing is needed to verify the diagnosis and to select the optimal treatment method