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<article article-type="research-article" dtd-version="1.3" xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xml:lang="ru"><front><journal-meta><journal-id journal-id-type="publisher-id">perinatology</journal-id><journal-title-group><journal-title xml:lang="ru">Российский вестник перинатологии и педиатрии</journal-title><trans-title-group xml:lang="en"><trans-title>Rossiyskiy Vestnik Perinatologii i Pediatrii (Russian Bulletin of Perinatology and Pediatrics)</trans-title></trans-title-group></journal-title-group><issn pub-type="ppub">1027-4065</issn><issn pub-type="epub">2500-2228</issn><publisher><publisher-name>Ltd. “The National Academy of Pediatric Science and Innovation”</publisher-name></publisher></journal-meta><article-meta><article-id pub-id-type="doi">10.21508/1027-4065-2024-69-6-59-65</article-id><article-id custom-type="elpub" pub-id-type="custom">perinatology-2091</article-id><article-categories><subj-group subj-group-type="heading"><subject>Research Article</subject></subj-group><subj-group subj-group-type="section-heading" xml:lang="ru"><subject>ОРИГИНАЛЬНЫЕ СТАТЬИ</subject></subj-group><subj-group subj-group-type="section-heading" xml:lang="en"><subject>ORIGINAL ARTICLES</subject></subj-group></article-categories><title-group><article-title>Динамика уровня белка плотных контактов энтероцитов Claudin-2 у детей первых  месяцев жизни</article-title><trans-title-group xml:lang="en"><trans-title>Dynamics of Claudin-2 tight junction protein levels in enterocytes of infants during the first  months of life</trans-title></trans-title-group></title-group><contrib-group><contrib contrib-type="author" corresp="yes"><contrib-id contrib-id-type="orcid">https://orcid.org/0000-0003-1062-7280</contrib-id><name-alternatives><name name-style="eastern" xml:lang="ru"><surname>Бавыкина</surname><given-names>И. А.</given-names></name><name name-style="western" xml:lang="en"><surname>Bavykina</surname><given-names>I. A.</given-names></name></name-alternatives><bio xml:lang="ru"><p>Бавыкина Ирина Анатольевна — д.м.н., доц. кафедры факультетской и паллиативной педиатрии</p><p>394036 Воронеж, ул. Студенческая, д. 10</p></bio><bio xml:lang="en"><p>Voronezh</p></bio><xref ref-type="aff" rid="aff-1"/></contrib><contrib contrib-type="author" corresp="yes"><name-alternatives><name name-style="eastern" xml:lang="ru"><surname>Бердников</surname><given-names>А. А.</given-names></name><name name-style="western" xml:lang="en"><surname>Berdnikov</surname><given-names>A. A.</given-names></name></name-alternatives><bio xml:lang="ru"><p>Бердников Андрей Анатольевич – зам. гл. врача по клинико-экспертной работе</p><p>394024 Воронеж, ул. Бурденко, д. 1</p></bio><bio xml:lang="en"><p>Voronezh</p></bio><xref ref-type="aff" rid="aff-2"/></contrib><contrib contrib-type="author" corresp="yes"><contrib-id contrib-id-type="orcid">https://orcid.org/0000-0002-3896-3297</contrib-id><name-alternatives><name name-style="eastern" xml:lang="ru"><surname>Звягин</surname><given-names>А. А.</given-names></name><name name-style="western" xml:lang="en"><surname>Zvyagin</surname><given-names>A. A.</given-names></name></name-alternatives><bio xml:lang="ru"><p>Звягин Александр Алексеевич — д.м.н., проф. кафедры пропедевтики детских болезней и поликлинической педиатрии</p><p>394036 Воронеж, ул. Студенческая, д. 10</p></bio><bio xml:lang="en"><p>Voronezh</p></bio><xref ref-type="aff" rid="aff-1"/></contrib><contrib contrib-type="author" corresp="yes"><contrib-id contrib-id-type="orcid">https://orcid.org/0000-0001-6251-2579</contrib-id><name-alternatives><name name-style="eastern" xml:lang="ru"><surname>Кубышкина</surname><given-names>А. В.</given-names></name><name name-style="western" xml:lang="en"><surname>Kubyshkina</surname><given-names>A. V.</given-names></name></name-alternatives><bio xml:lang="ru"><p>Кубышкина Анастасия Васильевна — зам. начальника центра подготовки научных и научно-педагогических кадров; к.м.н., врач–анестезиолог-реаниматолог</p><p>394036 Воронеж, ул. Студенческая, д. 10</p><p>394024 Воронеж, ул. Бурденко, д. 1</p></bio><bio xml:lang="en"><p>Voronezh</p></bio><xref ref-type="aff" rid="aff-3"/></contrib><contrib contrib-type="author" corresp="yes"><contrib-id contrib-id-type="orcid">https://orcid.org/0000-0001-5212-1005</contrib-id><name-alternatives><name name-style="eastern" xml:lang="ru"><surname>Антакова</surname><given-names>Л. Н.</given-names></name><name name-style="western" xml:lang="en"><surname>Antakova</surname><given-names>L. N.</given-names></name></name-alternatives><bio xml:lang="ru"><p>Антакова Любовь Николаевна — к.б.н., ст. науч. сотр. научно-исследовательского института экспериментальной биологии и медицины</p><p>394036 Воронеж, ул. Студенческая, д. 10</p></bio><bio xml:lang="en"><p>Voronezh</p></bio><xref ref-type="aff" rid="aff-1"/></contrib></contrib-group><aff-alternatives id="aff-1"><aff xml:lang="ru"><institution>ФГБОУ ВО «Воронежский государственный медицинский университет им. Н.Н. Бурденко» Минздрава России</institution><country>Россия</country></aff><aff xml:lang="en"><institution>Voronezh Burdenko State Medical University</institution><country>Russian Federation</country></aff></aff-alternatives><aff-alternatives id="aff-2"><aff xml:lang="ru"><institution>БУЗ ВО «Воронежская областная детская клиническая больница №1»</institution><country>Россия</country></aff><aff xml:lang="en"><institution>Voronezh Regional Children’s Clinical Hospital No. 1</institution><country>Russian Federation</country></aff></aff-alternatives><aff-alternatives id="aff-3"><aff xml:lang="ru"><institution>ФГБОУ ВО «Воронежский государственный медицинский университет им. Н.Н. Бурденко» Минздрава России; БУЗ ВО «Воронежская областная детская клиническая больница №1»</institution><country>Россия</country></aff><aff xml:lang="en"><institution>Voronezh Burdenko State Medical University; Voronezh Regional Children’s Clinical Hospital No. 1</institution><country>Russian Federation</country></aff></aff-alternatives><pub-date pub-type="collection"><year>2024</year></pub-date><pub-date pub-type="epub"><day>02</day><month>01</month><year>2025</year></pub-date><volume>69</volume><issue>6</issue><fpage>59</fpage><lpage>65</lpage><permissions><copyright-statement>Copyright &amp;#x00A9; Ltd. “The National Academy of Pediatric Science and Innovation”, 2024</copyright-statement><copyright-year>2024</copyright-year><copyright-holder xml:lang="ru">Ltd. “The National Academy of Pediatric Science and Innovation”</copyright-holder><copyright-holder xml:lang="en">Ltd. “The National Academy of Pediatric Science and Innovation”</copyright-holder><license xlink:href="https://www.ped-perinatology.ru/jour/about/submissions#copyrightNotice" xlink:type="simple"><license-p>https://www.ped-perinatology.ru/jour/about/submissions#copyrightNotice</license-p></license></permissions><self-uri xlink:href="https://www.ped-perinatology.ru/jour/article/view/2091">https://www.ped-perinatology.ru/jour/article/view/2091</self-uri><abstract><p>Неспецифичность симптомов нарушения толерантности к энтеральной нагрузке, отсутствие лабораторных и инструментальных методик, позволяющих определить ранние изменения проницаемости кишечной стенки, делают своевременную оценку состояния кишечного барьера у новорожденных сложной клинической задачей. Надежные и специфичные маркеры, позволяющие дифференцировать функциональные нарушения желудочно-кишечного тракта с начальными стадиями хирургической патологии у новорожденных — область, представляющая большой интерес для широкого круга специалистов.</p><sec><title>Цель исследования</title><p>Цель исследования. Оценка влияния гестационного возраста на уровень белка плотных контактов (Claudin-2) в сыворотке крови у детей в первые месяцы жизни.</p></sec><sec><title>Материалы и методы</title><p>Материалы и методы. В исследование включены 115 новорожденных с гестационным возрастом 33–41 нед (Me 38,0 [36,0; 39,0] нед). Дети разделены на группы в соответствии с гестационным возрастом: 1-я группа — доношенные, Me гестационного возраста 39,0 [38,0; 40,0] нед, n=80; 2-я группа — недоношенные, Me гестационного возраста 35,0 [34,5; 36,0] нед, n=35. Определяли уровень Claudin-2 в сыворотке крови в первые месяцы жизни. Результаты. Установлено увеличение концентрации сывороточного Claudin-2 с 3,434 [1,198; 7,866] нг/мл в первые 10 сут жизни до 5,147 [3,529; 8,211] нг/мл (p=0,02) к 1–1,5 мес, наиболее выраженное у доношенных (с 1,508 [1,004; 4,33] нг мл до 4,302 [3,188; 5,776] нг/мл; p&lt;0,001). Отмечена обратная связь гестационного возраста и концентрации Claudin-2 в первые дни жизни (–0,507; p&lt;0,001), ослабевающая к 1–1,5 месяцам (–0,342; p&lt;0,001). Выявили более высокие концентрации Claudin-2 у недоношенных в постменструальном возрасте 40–41 нед по сравнению с таковой у доношенных при рождении (p&lt;0,001).</p></sec><sec><title>Заключение</title><p>Заключение. Результаты демонстрируют влияние гестационного возраста на уровень Claudin-2 в первые месяцы жизни, что позволяет выдвинуть предположение об усиленной кишечной проницаемости у менее зрелых в гестационном отношении детей, опосредованной вариабельностью экспрессии Claudin-2.</p></sec></abstract><trans-abstract xml:lang="en"><p>The non-specific symptoms of impaired tolerance to enteral feeding and the lack of laboratory and instrumental methods for early detection of changes in intestinal permeability make timely assessment of the intestinal barrier in newborns a complex clinical challenge. Identifying reliable and specific markers that differentiate between functional gastrointestinal disorders and early stages of surgical pathology in newborns is an area of significant interest for a wide range of specialists.</p><sec><title>Purpose</title><p>Purpose. The study aimed to evaluate the impact of gestational age on the serum levels of Claudin-2, a tight junction protein in enterocytes, in infants during the first months of life.</p></sec><sec><title>Material and methods</title><p>Material and methods. The study included 115 newborns with gestational ages (GA) ranging from 33 to 41 weeks (median GA 38.0 [36.0–39.0] weeks). The infants were divided into two groups based on GA: Group 1 (term infants, median GA 39.0 [38.0–40.0] weeks, n=80) and Group 2 (preterm infants, median GA 35.0 [34.5–36.0] weeks, n=35). Serum Claudin-2 levels were measured during the first months of life using a Human CLDN2 enzyme immunoassay kit. Results. Serum Claudin-2 concentrations increased from 3.434 [1.198; 7.866] ng/ml in the first 10 days of life to 5.147 [3.529; 8.211] ng/ml (p=0.02) by 1–1.5 months, with the most pronounced increase observed in term infants (from 1.508 [1.004; 4.33] ng ml to 4.302 [3.188; 5.776] ng/ml, p&lt;0.001). An inverse correlation was noted between GA and Claudin-2 concentration in the first days of life (–0.507, p&lt;0.001), which weakened by 1–1.5 months (–0.342, p&lt;0.001). Additionally, higher Claudin-2 concentrations were observed in preterm infants at a postmenstrual age of 40–41 weeks compared to full-term infants at birth (p&lt;0.001).</p></sec><sec><title>Conclusion</title><p>Conclusion. The findings demonstrate the influence of GA on Claudin-2 levels in the first months of life, suggesting increased intestinal permeability in infants with lower gestational maturity, mediated by variable Claudin-2 expression.</p></sec></trans-abstract><kwd-group xml:lang="ru"><kwd>недоношенные</kwd><kwd>кишечная проницаемость</kwd><kwd>Claudin-2</kwd><kwd>белки плотных контактов</kwd><kwd>гестационный возраст</kwd></kwd-group><kwd-group xml:lang="en"><kwd>premature</kwd><kwd>intestinal permeability</kwd><kwd>Claudin-2</kwd><kwd>tight junction proteins</kwd><kwd>gestational age</kwd></kwd-group><funding-group><funding-statement xml:lang="ru">Коллективу БУЗ ВО ВОДБКБ№1 в лице Жидкова М.Л.  и коллективу НИИ ЭБМ ФГБОУ ВО ВГМУ  им. Н.Н. Бурденко МЗ России.</funding-statement><funding-statement xml:lang="en">To the staff of the Voronezh Regional Children’s Clinical  Hospital No. 1, represented by M.L. 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