Effects of pertussis toxin and <i>Bordetella pertussis</i> lipo-oligosaccharide on the specific toxicity and potency of whole-cell pertussis vaccines

Scientific relevance. The content of Bordetella pertussis lipo-oligosaccharide (LOS) and the residual levels of active pertussis toxin (PT) are generally accepted to be the primary factors that determine the reactogenicity of whole-cell pertussis vaccines. To improve the quality of whole-cell pertussis vaccines, it is both relevant and necessary to study the relationship between the toxicity of B. pertussis bacterial cell components and the main quality parameters of these vaccines, including their potency and specific toxicity, as termed in the WHO recommendations and the European Pharmacopoeia.Aim. This study aimed to analyse the effects of B. pertussis LOS and residual active PT on the specific toxicity and potency of adsorbed diphtheria, tetanus, and whole-cell pertussis (DTwP) vaccines.Materials and methods. The authors tested 57 commercial batches of adsorbed DTwP vaccines for compliance with the regulatory standards and product specification files. Vaccine batches that failed specific toxicity tests formed Group 1, and the other batches were designated as Group 2. The potency was tested in F1 CBA/Ca×C57BL/6J hybrid mice with experimentally induced meningoencephalitis that were immunised with DTwP and reference vaccines. The authors assessed the specific toxicity of DTwP vaccines by changes in body weight following intraperitoneal administration. The toxic activity was assessed indirectly by changes in body weight in the first 16–24 h (B. pertussis LOS) and on day 7 (PT) after dosing. The authors used Spearman’s rank correlation coefficient to measure the strength of correlation between the toxic activity of vaccine components and the specific toxicity and potency of the vaccine, which were established using the same vaccine batches.Results. The authors measured the toxic activity of LOS and residual active PT in the vaccine batches studied. The correlation coefficients between the specific toxicity and potency of the vaccines and the toxic activity of LOS were 0.113 (p&gt;0.05) and 0.049 (p&gt;0.05), respectively. Similarly, the correlation coefficients between the specific toxicity and potency of the vaccines and the toxic activity of PT accounted for 0.595 (p&lt;0.01) and –0.534 (p&lt;0.01), respectively.Conclusions. The authors studied the toxic activity of B. pertussis LOS and residual active PT in whole-cell pertussis vaccines and found an inverse correlation between the potency of the vaccines and the toxic activity of residual active PT. The study demonstrated that the specific toxicity test for whole-cell pertussis vaccines fails to detect and quantify B. pertussis LOS in the samples. The authors advise to determine the content of LOS in the B. pertussis strains intended for the production of whole-cell pertussis vaccines, which is not yet an accepted practice in the Russian Federation

Влияние коклюшного токсина и липоолигосахарида Bordetella pertussis на специфическую токсичность и защитную активность цельноклеточной коклюшной вакцины

Scientific relevance. The content of Bordetella pertussis lipo-oligosaccharide (LOS) and the residual levels of active pertussis toxin (PT) are generally accepted to be the primary factors that determine the reactogenicity of whole-cell pertussis vaccines. To improve the quality of whole-cell pertussis vaccines, it is both relevant and necessary to study the relationship between the toxicity of B. pertussis bacterial cell components and the main quality parameters of these vaccines, including their potency and specific toxicity, as termed in the WHO recommendations and the European Pharmacopoeia.Aim. This study aimed to analyse the effects of B. pertussis LOS and residual active PT on the specific toxicity and potency of adsorbed diphtheria, tetanus, and whole-cell pertussis (DTwP) vaccines.Materials and methods. The authors tested 57 commercial batches of adsorbed DTwP vaccines for compliance with the regulatory standards and product specification files. Vaccine batches that failed specific toxicity tests formed Group 1, and the other batches were designated as Group 2. The potency was tested in F1 CBA/Ca×C57BL/6J hybrid mice with experimentally induced meningoencephalitis that were immunised with DTwP and reference vaccines. The authors assessed the specific toxicity of DTwP vaccines by changes in body weight following intraperitoneal administration. The toxic activity was assessed indirectly by changes in body weight in the first 16–24 h (B. pertussis LOS) and on day 7 (PT) after dosing. The authors used Spearman’s rank correlation coefficient to measure the strength of correlation between the toxic activity of vaccine components and the specific toxicity and potency of the vaccine, which were established using the same vaccine batches.Results. The authors measured the toxic activity of LOS and residual active PT in the vaccine batches studied. The correlation coefficients between the specific toxicity and potency of the vaccines and the toxic activity of LOS were 0.113 (p&gt;0.05) and 0.049 (p&gt;0.05), respectively. Similarly, the correlation coefficients between the specific toxicity and potency of the vaccines and the toxic activity of PT accounted for 0.595 (p&lt;0.01) and –0.534 (p&lt;0.01), respectively.Conclusions. The authors studied the toxic activity of B. pertussis LOS and residual active PT in whole-cell pertussis vaccines and found an inverse correlation between the potency of the vaccines and the toxic activity of residual active PT. The study demonstrated that the specific toxicity test for whole-cell pertussis vaccines fails to detect and quantify B. pertussis LOS in the samples. The authors advise to determine the content of LOS in the B. pertussis strains intended for the production of whole-cell pertussis vaccines, which is not yet an accepted practice in the Russian Federation.Актуальность. Главными факторами, определяющими реактогенность коклюшной цельноклеточной вакцины, принято считать содержание липоолигосахарида Bordetella pertussis и остаточное содержание активного коклюшного токсина. Изучение токсического воздействия коклюшных компонентов бактериальной клетки B. pertussis на основные показатели качества цельноклеточной коклюшной вакцины (защитную активность и специфическую токсичность — термины, принятые в рекомендациях ВОЗ и Европейской фармакопее) актуально и необходимо для повышения качества препарата.Цель. Изучение токсического влияния липоолигосахарида B. pertussis и остаточного количества активного коклюшного токсина, присутствующих в цельноклеточной адсорбированной коклюшно-дифтерийно-столбнячной вакцине, на специфическую токсичность и защитную активность препарата.Материалы и методы. Исследовали 57 коммерческих серий адсорбированной коклюшно-дифтерийно-столбнячной вакцины на соответствие показателей качества требованиям нормативной документации. К группе 1 отнесли серии, не выдержавшие испытания по показателю «Специфическая токсичность»; к группе 2 — соответствующие требованиям. Защитную активность определяли в тесте экспериментального менингоэнцефалита на мышах линии F1 CBA×C57Bl/6j, иммунизированных АКДС- и референс-вакцинами. Специфическую токсичность препарата определяли в тесте изменения массы тела мышей после внутрибрюшинного введения вакцины АКДС. Токсическое действие липоолигосахарида оценивали опосредованно — через изменение массы тела мышей в первые 16–24 ч; коклюшного токсина — на 7-е сутки. Корреляционный анализ тесноты связи между установленными показателями токсического действия исследуемых компонентов и показателями специфической токсичности и защитной активности, полученными в этих же сериях вакцины, проводили при помощи коэффициента ранговой корреляции Спирмена.Результаты. Опосредованно определили токсическое действие липоолигосахарида и остаточного количества активного коклюшного токсина в исследуемых сериях. Коэффициенты корреляции между показателями специфической токсичности и защитной активности вакцины и показателями токсического действия липоолигосахарида составили 0,113 (р&gt;0,05) и 0,049 (р&gt;0,05) соответственно, для коклюшного токсина — 0,595 (р&lt;0,01) и –0,534 (р&lt;0,01) соответственно.Выводы. Выявили и оценили токсическое действие липоолигосахарида B. pertussis и остаточного количества активного коклюшного токсина в цельноклеточной вакцине; установили обратную корреляционную связь между защитной активностью вакцины и токсическим действием остаточного уровня активного коклюшного токсина. Тесты продемонстрировали, что показатель, оценивающий специфическую токсичность цельноклеточной коклюшной вакцины, не отражает присутствие и содержание липоолигосахарида в вакцине. Опираясь на результаты исследования, можно утверждать, что в производственных коклюшных штаммах, используемых для изготовления цельноклеточной коклюшной вакцины, целесообразно определять содержание липоолигосахарида B.pertussis, что в Российской Федерации в настоящее время не принято

The effectiveness of spatially cross-linked polymer in the postoperative epidural fibrosis prevention: an experimental study

Introduction. Epidural fibrosis is an urgent problem in modern spinal surgery and orthopedics. The formation of connective tissue in the epidural space after performing surgical interventions on the spinal column inevitably leads to adhesion of the latter to the dura mater and compression of neural structures, followed by the formation of clinical and neurological symptoms. The  search for literary sources in domestic and foreign scientific databases has demonstrated the presence of several works studying the effectiveness of barrier methods for preventing the development of epidural fibrosis. It should be noted that the results of these studies are ambiguous and largely contradictory.The purpose was to study the effectiveness of using a spatially cross-linked polymer in the postoperative lumbar epidural fibrosis prevention in an experiment.Materials and methods. The study included 26 male Wistar rats (average body weight 338.5±9.07 g), which were divided into two groups: Group I (control, n = 12): animals underwent laminectomy at the level of vertebral bodies LVII – SI  without application of spatially crosslinked polymer; Group II (experimental, n = 14): animals underwent laminectomy at the level of vertebral bodies LVII – SI  followed by application of a spatially cross-linked polymer to the dura mater. The morphological and instrumental parameters were studied.Results. Significant differences were noted in the severity of epidural fibrosis (χ2 = 14.846, p = 0.003), the number of newly formed vessels (F = 14.371, p&lt;0.001), the number of fibroblasts (F = 11.158, p&lt;0.001), as well as in the severity of vertebral stenosis channe l according to multislice computed tomography (χ2 = 17.207, p=0.002) between the control and experimental groups of animals.Conclusion. Application of a spatially cross-linked polymer to the dura mater is an effective way to prevent the development of postoperative epidural fibrosis

Acute myocardial ischemia: changes of free circulating mtDNA level in blood after occlusion of the upper one-third left descending branch of the coronary artery

The aim of the present study is to analyze the dynamics of free circulating mtDNA level in blood after occlusion of the upper one-third left descending branch of the coronary artery. We showed that the concentration of free circulating mtDNA of blood tends to decrease 24 hours after ligation; it increased and reached values close to control samples 48 and 72 hours after ligation. These data define the need in further investigation of the dynamics of this parameter during later periods of myocardial infarction modeling that will contribute to objective evaluation of its significance for acute myocardial damage diagnostics and prognosis

The level of blood plasma mitochondrial DNA upon acute myocardium damage in experiment

The aim of the present investigation is to study the level of plasma mtDNA as a potential marker of cardiomyocyte damage in 2 and 4 h after subcutaneous injection of adrenaline and during the formed morphological alterations of the myocardium (3 days). Methods. Real time PCR. Male Wistar rats were used as the experimental animals. Results. It was shown that during the increase in the activity of cytolysis biomarkers, at the first hours after adrenaline injection, no reliable increase is observed in the level of free circulating blood mtDNA. A tendency of 2.5-fold increase in this parameter was established at the third day after adrenaline injection during the development of acute inflammatory process in the myocardium. On the whole, further researches are needed on the dynamics of mtDNA level upon acute damage of the myocardium in experimental and clinical investigations for unbiased estimation of the prospects of using the parameter in laboratory diagnostics