Modern endoscopic solutions in pediatric practice and topical issues of pediatric gastroenterology with the use of new endoscopic technologies are discussed. Attention is drawn to the need for the use of existing modern endoscopic and gastroenterological protocols for the diagnosis of diseases of the gastrointestinal tract, as well as the creation of new protocols for the most common nosological forms; the role of correct and high-quality endoscopic and pathomorphological interpretation of the data obtained for the verification of the diagnosis of gastrointestinal diseases is emphasized.

This literature review covers the pathophysiological features of water and sodium exchange in newborns. The main mechanisms regulating fluid and electrolyte balance in newborns are poorly studied. The volume and composition of the extracellular fluid are provided by the functional activity of the kidneys under the control of the neuroendocrine system. The antidiuretic hormone plays the main role in the regulation of water excretion by the kidneys. The volume of intracellular fluid depends on the passive water transport with the participation of aquaporins. Lability of water and electrolyte metabolism in newborns may be accompanied by hyponatremia. For various pathological conditions in the neonatal period, certain types of hyponatremias are characteristic. Correction of hyponatremia should be carried out taking into account its pathophysiological type. Hyponatremia is a common complication associated with severe neonatal brain damage. Hyponatremia contributes to brain damage as an independent factor. The study of indicators of water and electrolyte balance in the neonatal period has an important prognostic value for early detection of damage to the central nervous system.

The problem of intrauterine growth retardation is currently relevant, as it is one of the causes of neonatal morbidity and mortality. Purpose. To study the course of the neonatal period and evaluate the content of arginine and glutamic acid in full-term newborns depending on the severity of intrauterine growth retardation.
Material and methods. 78 full-term newborns with intrauterine growth retardation according to hypotrophic type were examined. The content of glutamic acid and arginine in blood serum was determined in the early neonatal period by capillary electrophoresis using an unmodified quartz capillary (Kapel-105, Lumeks, St. Petersburg, Russia).
Results. Markers of the formation of a severe degree of intrauterine growth retardation were identified: increased levels of glutamic acid and arginine, taking into account impaired cerebral blood flow in the early neonatal period. A model is proposed for predicting the persistence of a severe degree of intrauterine growth retardation in newborns by the end of the neonatal period.
Conclusion. The proposed diagnostic criteria make it possible to start specific therapy in a timely manner in order to prevent the formation of a severe degree of intrauterine growth retardation.

Neonatal sepsis is a problem still relevant for healthcare in Russia and worldwide due to high mortality and resistance to treatment. Generalization of infection in newborns occurs because of innate immunity deficiency that particularly leads to neutrophil and monocyte malfunction. Nowadays clinical practice of neonatal sepsis diagnostics does not include phagocytes functional testing.
Purpose. The study aims at evaluating the ability of sepsis biomarkers (CRP, PCT, lactate, CD64, CD16, HLA-DR) to differentiate the pathogenesis of organ dysfunction in newborns in the ICU setting.
Material and methods. We assessed the surface expression of neutrophil CD64 and CD16, as well as monocytic HLA-DR in newborn ICU patients with different genesis of multiple organ failure — sepsis, asphyxia and combined; as well as different outcomes of hospitalization in the ICU — survivors and deaths.
Results. We have shown a significant increase in the neutrophil CD64 expression and a decrease in the monocytic HLA-DR in infectious and combined genesis of multiple organ failure compared with severe asphyxia; deaths were associated with reduced expression of neutrophil CD16.
Conclusion. Our data could substantiate combined use of the phagocytes functional testing indicators together with conventional sepsis biomarkers in order to increase their prognostic and predictive value.

Neuronal ceroid lipofuscinosis type 2 (NCL2) is a severe, continuously progressive hereditary metabolic disease for which there is an effective enzyme replacement therapy.
Purpose. To study the opinions of specialists (pediatric neurologists, neurologists-epileptologists, geneticists) about the obstacles to the early diagnosis of neuronal ceroid lipofuscinosis type 2 in patients.
Material and methods. The study was conducted by the method of in-depth interviews. 25 physicians dealing with NCL2 pts took part in the interview.
Results. From 2000 to 2021, 45 patients with NCL2 were identified in the Russian Federation. Data on the course of the disease were obtained from 38 patients aged 3 to 11 years, of which 16 received enzyme replacement therapy. At the time of the interview, 32/38 were alive, 4/32 had died, and outcome data for 2 patients were missing. The age of onset of the first symptoms varied significantly: from 1 year 10 months to 3 years 6 months. The median age at which children were diagnosed with NCL2 was 52 months, or 4 years 5 months, but it varied from 12 to 96 months. At the time of diagnosis, in addition to epileptic seizures and delayed speech development, ataxia and loss of motor development, as well as other symptoms, were already noted. EEG was performed in 73% of all cases (with photostimulation only in 34%). MRI at an early stage of the disease was performed in only 40%. Only 46% of patients receive (or have ever received) enzyme replacement therapy. In 41% of cases, enzyme replacement therapy was not prescribed due to the long-term diagnosis of NCL2, which led to a palliative status and refusal of the patients’ parents from therapy.
Conclusion. Early diagnosis of NCL2 is difficult due to the non-specificity of the first symptoms, as well as due to the poor awareness of doctors about the disease and the main methods of its diagnosis, which leads to late prescribing of enzyme replacement therapy.

Primary ciliary dyskinesia is a rare genetically determined pathology that leads to chronic inflammatory damage to the respiratory tract, hearing organs and impaired fertility. This article presents the preliminary results of a study conducted in the clinic aimed at the possibility of predicting the clinical course of the disease depending on the genetic variants of the disease, which enables, with timely diagnosis, personalizing the approach to the treatment of children with such a disabling disease as primary ciliary dyskinesia.
Purpose. To determine the clinical and genetic variants of primary ciliary dyskinesia, and to identify patterns of disease development.
Material and methods. The study included children from 0 to 18 years old with a verified defect of the ciliary apparatus, by analyzing the mobility of the cilia of the ciliary epithelium of the mucous membrane of the respiratory tract, and who underwent a next generation sequencing exome study.
Results. The study revealed characteristic patterns of target organ damage, prevailing in a group of children with impaired cilia assembly factor, as well as in a group of children with damaged dynein arms.
Conclusion. Thus, conducting a genetic examination in children with suspected primary ciliary dyskinesia is relevant not only to confirm the disease, but also to predict the course of the disease.

Recurrent episodes of bronchial obstruction in preschool children are one of the important risk factors for the development of bronchial asthma.
Purpose. The study aimed at investigating the clinical and immunological characteristics of children with acute bronchitis and to determine the clinical effectiveness of course anti-inflammatory therapy.
Material and methods. The study was a single-center prospective cohort, including 1–5-year-old patients with acute bronchitis (main group, n = 109): a group with acute simple bronchitis (n = 34) and acute obstructive bronchitis (n = 75). Reference group: children of health group 2 (n = 29). Clinical and anamnestic and laboratory methods were used. Patients with a positive API (Asthma Predictive Index) were administered montelukast at a dose of 4 mg orally once a day for 3 months (control points at 1 and 3 months), reference patients received symptomatic therapy for respiratory infection. The end point of the study is the absence of bronchial obstruction. The effectiveness of the use of Montelukast was evaluated by calculating the clinical index, efficiency coefficient.
Results. A statistically significant predominance of intoxication symptoms was found in patients with acute simple bronchitis (p = 0.02), signs of respiratory failure (p < 0.001), and peripheral eosinophilia — in children with acute obstructive bronchitis (p = 0.02). In etiology, rhinovirus significantly prevailed in patients with bronchial obstruction, and RS virus prevailed in patients with acute simple bronchitis (p = 0.02). The cytokine profile of patients with acute obstructive bronchitis is characterized by a decrease in the levels of macrophage inflammatory proteins (p = 0.01) and IL-8 (p = 0.048). A prolonged course of montelukast in children with a positive API significantly reduces the severity of subsequent acute respiratory infections, reduces the frequency of bronchial obstruction and the risk of bronchial asthma (p < 0.001).
Conclusion. Evaluation of the results of montelukast therapy demonstrated clinical efficacy in patients with a positive API index.

Purpose. The study assessed left ventricle longitudinal strain of the endocardial, middle, and epicardial layers in children from one to five years old, born with low, very low, and extremely low body weight.
Material and methods. The study was performed in 204 children aged from one to five years; of these, 53 children were prematurely born late in pregnancy, 103 children were born very preterm, and 48 children were born healthy and full-term. The left ventricle longitudinal strain of the endocardial, middle, and epicardial layers was assessed off-line using the Speckle Tracking Imaging-2D Strain technology.
Results. Disturbance of the transmural gradient strain of left ventricle wall were detected in 11.32% of prematurely born late in pregnancy children and in 16.5% of very preterm children. A decrease of left ventricle segments strain was registered in 33.96% of children prematurely born late in pregnancy and in 18.44% very preterm children. In children of the same age, born healthy and full-term, transmural wall gradient disturbances and decrease of strain in left ventricle segments were not observed. In children prematurely born late in pregnancy, the disturbance of the transmural strain gradient of left ventricle and the decrease of strain in left ventricle segments are not associated with left ventricle remodeling.
Conclusion. The development of the cardiovascular system in children of early and preschool age, born prematurely with low, very low, and extremely low body weight, is characterized by disturbances in the transmural strain gradient of left ventricle wall, due to the processes of postnatal growth and development of the child’s heart, which requires monitoring on an outpatient basis in polyclinic in childhood — by a pediatric cardiologist and a pediatrician, and in adulthood — by a cardiologist and therapist.

Maladaptation processes in the cardiovascular system in child athletes are associated with changes in electrophysiological processes in the myocardium. To identify risk groups for the development of the cardiovascular system pathology among this contingent, it is possible to use a non-invasive technique: ECG dispersion mapping.
Purpose. To identify changes in electrophysiological processes in the myocardium of the left and right ventricles in child athletes in response to physical activity.
Material and methods. 279 healthy children without chronic disease aged from 12 to 18 years were under observation. A group of 209 children involved in sports has been identified. The gender distribution is as follows: 153 boys (73%) and 56 girls (27%). The reference group included 70 children not involved in sports. All child athletes had access to the training and competition process. Within the study group, 4 subgroups were allocated in accordance with sports: A subgroup — children attending the football section (51 boys); B — basketball (37 boys and 22 girls); C — volleyball (29 boys and 27 girls); D — martial arts (36 boys and 7 girls). All children underwent dispersion mapping of the electrocardiogram using the Cardiovisor software and hardware complex before and after the exercise test. The processes of depolarization and repolarization in the myocardium of the left and right ventricles were analyzed on the basis of G3–G6 indices. Statistical processing of the results was carried out using MS Excel, Stata.
Results. The analysis of electrophysiological processes in the myocardium of the left and right ventricles in child athletes showed statistically significant differences in comparison with the reference group. In all G3-G6 indicators in the main group, a moderate deviation was noted, while all values in the reference group were within normal limits in more than 92%. Moderate physical exertion led to the registration of both moderate and pronounced electrophysiological disturbances in the myocardium, especially in children engaged in highly dynamic sports, namely basketball.

Systemic lupus erythematosus is an immunopathological disease which is characterized by a poor prognosis. Biologics applied in the disease treatment allow reducing the corticosteroid toxicity and controlling the disease.
Purpose. To evaluate the efficacy and safety of rituximab therapy in children with systemic lupus erythematosus.
Material and methods. The retrospective study included data of 48 patients with systemic lupus erythematosus treated with rituximab. Systemic lupus erythematosus was diagnosed based on the SLICC classification criteria. Patients were assessed at baseline disease status, at the time of rituximab initiation and follow-up. The indications for the rituximab were: lupus nephritis, CNS involvement, and hematological involvement resistant to the standard therapy, and in cases of severe corticosteroid toxicity.
Results. During rituximab therapy the significant decrease of the SELENA–SLEDAI activity index was observed. There was a significant decrease of the level of antibodies against dsDNA, normalization of the levels of hemoglobin, ESR, complement C4. The proportion of patients with cytopenia decreased up to their complete absence in patients receiving therapy for three years. The number of patients with active lupus nephritis decreased from 16 at the time of rituximab initiation to 1 after 3 years of therapy. Significant dynamics of proteinuria and hematuria was noted, except for 1 patient. The daily dose of corticosteroids was reduced by 90% from baseline in patients treated for 3 years. Serious adverse events included three deaths in patients with high systemic lupus erythematosus activity with uncontrolled macrophage activation syndrome associated with infections. Various infectious complications, hypogammaglobulinemia, which required replacement therapy with intravenous immunoglobulin, were also recorded.
Conclusion. Rituximab can be considered as an option for the treatment of severe forms of systemic lupus erythematosus which are resistant to standard therapy. Further studies are required to evaluate efficacy and safety.

The control of urine retention and urination function in children is finally established by the age of 4–5 — it is at this age that the type of urination becomes adult. The stages of the formation of urination function are based on many factors — a decrease in the physiological hypersensitivity of the M-cholinergic receptors of the bladder to acetylcholine, an increase in inhibitory supraspinal effects on the parasympathetic reflex arc, which provides a level of intravesical pressure, on the process of myelination of the brain pathways, on the maturation of the higher cortical center of urination and strengthening of connections with subcortical structures. A tabular assessment of the manifestations of delay and impaired bladder function in children allows us to determine the level of maturity of the system responsible for the urination function. The development of control over the urination is greatly hindered by wearing diapers, failure to provide potty training, and improper water intake schedule in children. The authors of the article identified three age groups of children with enuresis and delayed formation of bladder function and determined at what age which disorders are most relevant. Assessment of the maturity of urination in children with enuresis allows us to analyze the stages of delayed bladder function. In the younger age group (6–7 years), the delay in the formation of self-service skills in the implementation of the act of urination prevailed, including the use of a gender-unreasonable posture. At the age of 8–11 years, there was a predominance of delayed formation of emptying reflexes. At the age of 12–14, there were signs of hypoactivity of the bladder.

The article discusses the main risk factors for the formation of insufficiency and deficiency of vitamin D in children. Particular attention is paid to the course and dietary preferences of the mother during pregnancy, the intake of vitamin and mineral complexes, the nutrition of the child after birth, the type of feeding, the subsidy of vitamin D preparations and complementary foods. 1246 children under four years of age with no history of vitamin D deficiency were examined. With clinical manifestations of rickets, 52 children were identified, who underwent determination of 25(OH) D in serum, while low availability was detected in 21.1%, vitamin D insufficiency — in 63.4% of children, deficiency — in 15.3% of cases. There was an interaction between the use of dairy products enriched with a vitamin-mineral complex containing vitamin D and Ca, the use of therapeutic doses of vitamin D, and an increase in the level of 25 (OH) D in the blood serum.

Congenital tuberculosis is a fatal disease in the absence of treatment. The diagnosis is difficult due to polymorphic and nonspecific symptoms in neonates, as well as the lack of alertness of neonatologists and pediatricians. Less than 500 confirmed cases of congenital tuberculosis have been described in the available literature. Mortality ranges from 15 to 33%. Early diagnosis and adequate therapy are essential to improve the prognosis of the disease. Two cases of pulmonary congenital tuberculosis in premature neonates with a positive maternal and familial history of tuberculosis is presented. The clinical symptoms and radiological features started on the days 24 and 48 of life, respectively. Shortness of breath, low blood oxygen level requiring oxygen therapy, fever, and impaired general well-being revealed. The chest X-ray revealed bilateral polysegmental infiltrative lesions with the formation of a cavity of destruction in one case. The diagnosis was established after the detection of M. tuberculosis DNA in gastric aspirates. Patients received therapy according to a regimen designed for multidrug-resistant tuberculosis, including conventional anti-TB drugs in combination with linezolid, fluoroquinolones, meropenem, and aminoglycosides. The infectious syndrome in a premature newborn associated with pneumonia resistant to standard antibiotic therapy, the presence of tuberculosis in the mother, relatives, or siblings require a work-up for the detection of M. tuberculosis and instrumental diagnostics. Early diagnosis and treatment are critical for improving the prognosis of the disease.

Lysosomal acid lipase deficiency is a chronic hereditary degenerative disease, substantially worsening quality of life and leading to lethal outcome. The condition is caused by a mutation of the LIPA gene, that is encoding lysosomal acid lipase, resulting in build-up of cholesterol esters and triglycerides. Clinical-pattern is quite variable: from rapidly worsening lethal infant form and severe infant cases with cirrhosis and liver dysfunction in adolescents to subclinical, mostly asymptomatic forms, manifesting in adults. Thus, major part of patients remains unexamined and the pathology itself undiagnosed, so the real incidence is unclear. This article describes clinical case of the diagnostics of lysosomal acid lipase deficiency in RNO-Alania. Efficiency and safety of enzyme substitution treatment is shown.

The reason for the publication of this article was the increase in the number of children with long-standing organic foreign bodies in the respiratory tract, the late diagnosis of which causes severe complications. The article presents the three most significant cases from the general series, when the diagnosis and treatment tactics at the stages of treatment were associated with errors both at the prehospital stage and in the hospital. In the first clinical case, as it turned out, the child had aspired multiple foreign bodies. The first bronchoscopy revealed one solid foreign body. Due to severe fibrinous-purulent endobronchitis and contact bleeding, the bronchoscopy procedure was aborted. However, after 10 days, the child independently coughed up the second seed, which was a surprise to us. Control bronchoscopy after 3 weeks revealed no foreign bodies. In the second clinical observation, a child developed bronchiectasis due to a long stay of a foreign body in the respiratory tract. The third case demonstrates the diagnosis and treatment tactics in a child with a foreign body against the background of a coronavirus infection. In the first and third cases, the results of treatment were satisfactory. In the second case, a long stay of peanuts in the respiratory tract led to bronchiectasis in the lower lobe of the left lung, which required its removal. In the follow-up, there are no complaints, the child grows and develops according to age. The study analyzes the mistakes made at the stages of diagnosis and treatment of children with foreign bodies in the respiratory tract.
Conclusion. Young children with long-term and atypically current respiratory diseases, dubious and even normal radiological picture with the absence of comprehensive information on the anamnesis of diseases should alert the doctor to the possibility of aspiration of a foreign body in the respiratory tract and serve as the basis for performing bronchoscopy.

Myocardial remodeling is well-known to be both an adaptive option under certain conditions of life (sports, pregnancy, etc.), and the result of cardiovascular pathology. The study of the features of cardiac remodeling includes the involvement of cardiomyocytes in the process by the level of troponins, creatine phosphokinase, and its cardiac isoform as markers of ischemia and necrosis. Also, neurohormonal rearrangement is evaluated using a natriuretic peptide, and endothelial dysfunction is determined using a C–reactive protein. The level of matrix metalloproteinases (MMP) and their tissue inhibitors (TIMP) reflects the degree of the proteolytic activity and collagen fibers’ degradation. However, there are no clear biochemical markers of “adaptive heart” and pathological changes in different age periods, in the climatic environment, various types and severity of sports loads, especially when evaluating matrix metalloproteinases and their tissue inhibitors. The primary task in determining the criteria for pathological remodeling of the myocardium becomes the definition of normative indicators.
The aim of the study was to determine the reference values of the main biochemical markers of cardiac remodeling in healthy adolescents living in the Far North. The levels of troponin I, creatine phosphokinase-MV, aspartate aminotransferase did not exceed the generally accepted standard values. There were correlations between lactate dehydrogenase, aspartate aminotransferase, and mass-growth indicators of adolescents. Markers of extracellular matrix degradation (MMP-9, TIMP-1 and TIMP-4, MMP-9/ TIMP-1) differed from the data available in the published studies, which is probably due to the influence of tissue hypoxia associated with the climatic living conditions and the age in children of the study group.

Infant deaths like a litmus paper reflects the level of development of the medical care in the country. The active development of this industry in general and pediatric medicine in particular made it possible to reduce this indicator significantly, but its structure has changed. Now the contribution of congenital malformations has become more significant than 10–15 and even 40 years ago. New reality provides new challenges to the professional community in medical terms as much as in organizational and legislative terms. We present the current system of organizing care for children with congenital malformations, implemented in the Moscow Region, which includes obstetric service (screening for malformations, expert examination and prenatal counseling, delivery in a specialized perinatal center), neonatal, pediatric surgical (prenatal counseling, surgical care in the delivery room, correction of malformations in the neonatal period, subsequent staged treatment and observation) and pediatric services (follow-up observation). The proposed algorithm is aimed at reducing the likelihood of a child being born with an undiagnosed or lethal defect, preventing the uncontrolled development of a critical condition, and providing the most optimal and safe method of surgical treatment and postoperative management tactics. The introduction of such a system will not only reduce infant mortality, but also reduce the disability of the child population.

The survival rate among children with cancer was significantly improved in recent years. About 40% of these patients, however, suffer from late complications of anticancer treatment. Risk factors of late kidney impairment include beginning of specific treatment before the age of 5 years; pre-existing kidney pathology; high cumulative dose of chemotherapy agents and radiation; surgery, including neurotomy. It is currently impossible to predict individual long-term effects of therapy. For this reason, the International Cancer Group suggests that all children who have undergone specific antitumor therapy be included in the risk group for the development of longterm complications, and to follow up asymptomatic patients surviving cancer without kidney function and structure impairment with at least yearly monitoring of blood pressure, blood count, urinalysis, serum creatinine, urea, K, Na, Ca, P, Mg, alkaline phosphatase. We described the spectrum of kidney diseases including ureterohydronephrosis, renovascular hypertension, Fanconi syndrome, and postradiation nephrosclerosis manifested from 8 months to 8 years after specific antitumor treatment.

The article discusses the prospects of rehabilitation of children with congenital cardiovascular anomaly, including those after surgery. The author provides evidence that it is essential to create a system of physical, psychological, and social rehabilitation for this category of patients at all stages of medical care: in hospital, at the sanatorium, and during the follow-up, taking into account the basic principles of rehabilitation (an early start, a stage-by-stage approach, coherence, continuity, consistency, individualization of the rehabilitation plan, etc.). The sanatorium treatment at the famous climatic and balneological children’s health resorts of the Black Sea coast appears to be the most physiologically relevant stage contributing to the improvement of the regulatory processes of cardiac activity and providing optimal results of restorative treatment and rehabilitation for the young patients with congenital heart defects in the remote postoperative period. The creation of the All-Russian Rehabilitation Center for children with cardiovascular pathology, including children after heart surgery, in the Republic of the Crimea should be considered in the context of the further development and implementation of measures in accordance with the List of Instructions of the President of the Russian Federation following the meeting of the Coordinating Council under the President of the Russian Federation on the implementation of the National Strategy of Action in the Interests of Children for 2012–2017 of March 31, 2017.