Examination of periodontal tissue in modeling microgravity conditions

2018 ◽  
Vol 17 (2) ◽  
pp. 49-56
Author(s):  
M. A. Skedina ◽  
Z. O. Solov’Eva ◽  
A. A. Kovaleva ◽  
V. K. Ilyin

A complex assessment of the condition of periodontal tissues was carried out, including microcirculatory, microbiological and immunological studies in conditions simulating microgravity. Under conditions of a 5-day «dry» immersion, 8 male volunteers were subjected to blood flow velocity measuring in microcirculatory bed of periodontal disease, measuring of immunoglobulins level in the oral fluid, and investigations of periodontal microflora. On the 5th day of immersion and on 7-th day after immersion, there was a decrease in the blood flow velocity in the periodontal tissues in mandible (p≤0.05) in maxilla. Five main parodontopathogenic microorganisms predominated after experiment. At the same time, the growth trend of sIgA was noted, which, probably, can be associated with the appearance of parodontopathogenic microflora in the oral cavity. A comprehensive study showed a predisposition of periodontal tissues in conditions of immersion to inflammatory diseases and a decrease of periodontal disease barrier functions.

Author(s):  
V.K. Ilyin ◽  
V.N. Tsarev ◽  
M.A. Skedina ◽  
Z.O. Soloviova ◽  
E.N. Nikolaeva ◽  
...  

Введение. Условия космического полета приводят к изменению функциональных показателей многих органов и систем организма человека. Накопленный опыт показывает, что с увеличением длительности полета большое значение приобретают комплексные исследования состояния зубочелюстной системы. Цель исследования - изучение анаэробной составляющей микробиоты, иммунологических показателей ротовой жидкости и скорости кровотока в микроциркуляторном русле пародонта при моделировании невесомости. Методика. Наиболее адекватной моделью, воспроизводящей эффекты факторов полета в земных условиях, является «сухая» иммерсия. Было проведено комплексное обследование 20 мужчин добровольцев, в возрасте от 19 до 26 лет. В качестве модели микрогравитации использовали 5-суточную «сухую» иммерсию. Изучение состояния тканей пародонта включало микробиологические, иммунологические и микроциркуляторные исследования. Исследования выполняли в 1-е сут (фон), на 5-е сут иммерсии (выход) и на 7-е сут по окончании иммерсии. Качественный состав основных пародонтопатогенных видов микроорганизмов определяли методом полимеразной цепной реакцией. Концентрацию иммуноглобулинов (sIgA, IgA, IgМ) в ротовой жидкости - методом ИФА с помощью соответствующих наборов реагентов ЗАО «Вектор-Бест». Оценку кровотока в тканях пародонта проводили методом высокочастотной ультразвуковой допплеровской флуометрии ультразвуковым допплерографом «Минимакс-Допплер-К» (г. Санкт-Петербург) с датчиком непрерывного излучения, рабочая частота - 20 МГц. Результаты. Во время эксперимента в составе микробиоты пародонта обнаружено появление 5 основных пародонтопатогенных видов микроорганизмов (Aggregatibacter actinomycetemcomitans, Tannerella forsythia, Prevotella intermedia, Porphyromonas gingivalis, Treponema denticola). Отмечен рост концентрации в десневой жидкости sIgA, что связано с появлением пародонтопатогенной микробиоты. На 5-е сут и 7-е сут после «сухой» иммерсии у 12 человек отмечено статистически значимое снижение скорости кровотока в микроциркуляторном русле тканей пародонта как нижней, так и верхней челюсти. У 6 человек наблюдалась морфофункциональная перестройка микроциркуляторного русла в виде дилатации емкостных сосудов (венул) с частичным обеднением капиллярного звена, что свидетельствует о реакции венулярной компоненты на моделируемую микрогравитацию. Заключение. Комплексное исследование показало предрасположенность тканей пародонта в условиях «сухой» иммерсии к развитию воспалительных заболеваний и снижению барьерных функций пародонта.Comprehensive evaluation of 20 male volunteers aged 19-26 was conducted during exposure to 5-day “dry” immersion (DI). The aim was to examine periodontal tissues in the conditions of 5-day “dry” immersion, specifically, to study the anaerobic component of periodontal microbiota, immunological parameters of the oral fluid, and blood flow velocity in the periodontal microcirculation (PMC). Methods. Microgravity was modeled with the 5-day DI. Evaluation of the condition of periodontal tissues included microbiological, immunological, and microcirculatory studies. The studies were performed on day 1 (baseline), day 5 of immersion (completion), and day 7 upon the end of immersion. All studies were performed in the fasting state, before toothbrushing, in the supine position in the immersion bath, and in the sitting position 7 days after the immersion. PMC was studied at the same time points as in the immunoglobulin study. Blood flow in periodontal tissues was measured using the high-frequency ultrasonic Doppler fluorimetry (HFUDF) with a Minimax-Doppler-K ultrasonic dopplerograph (St. Petersburg) with a continuous radiation sensor at an operating frequency of 20 MHz. Results. Five major periodontopathogenic bacteria (Aggregatibacter actinomycetemcomitans, Tannerella forsythia, Prevotella intermedia, Porphyromonas gingivalis, and Treponema denticola) emerged as a part of the periodontal microbiota during the experiment. An increased concentration of sIgA was observed in the gingival fluid, which was associated with the emergence of periodontopathogenic microbiota. On day 5 of SI and day 7 following SI, 12 subjects had a statistically significant decrease in blood flow velocity in PMC of both the lower and upper jaws. 6 subjects showed morphological and functional rearrangement of the PMC, including dilation of capacitance vessels (venules) with partial capillary depletion, which indicated a venular component response to the conditions of modeled microgravity. Conclusion. This comprehensive study showed predisposition of periodontal tissues to development of inflammatory diseases and impaired functioning of the periodontal barrier under the conditions of DI.


2020 ◽  
Vol 133 (3) ◽  
pp. 773-779
Author(s):  
Christopher Wendel ◽  
Ricardo Scheibe ◽  
Sören Wagner ◽  
Wiebke Tangemann ◽  
Hans Henkes ◽  
...  

OBJECTIVECerebral vasospasm (CV) is a delayed, sustained contraction of the cerebral arteries that tends to occur 3–14 days after aneurysmal subarachnoid hemorrhage (aSAH) from a ruptured aneurysm. Vasospasm potentially leads to delayed cerebral ischemia, and despite medical treatment, 1 of 3 patients suffer a persistent neurological deficit. Bedside transcranial Doppler (TCD) ultrasonography is used to indirectly detect CV through recognition of an increase in cerebral blood flow velocity (CBFV). The present study aimed to use TCD ultrasonography to monitor how CBFV changes on both the ipsi- and contralateral sides of the brain in the first 24 hours after patients have received a stellate ganglion block (SGB) to treat CV that persists despite maximum standard therapy.METHODSThe data were culled from records of patients treated between 2013 and 2017. Patients were included if an SGB was administered following aSAH, whose CBFV was ≥ 120 cm/sec and who had either a focal neurological deficit or reduced consciousness despite having received medical treatment and blood pressure management. The SGB was performed on the side where the highest CBFV had been recorded with 8–10 ml ropivacaine 0.2%. The patient’s CBFV was reassessed after 2 and 24 hours.RESULTSThirty-seven patients (male/female ratio 18:19), age 17–70 years (mean age 49.9 ± 11.1), who harbored 13 clipped and 22 coiled aneurysms (1 patient received both a coil and a clip, and 3 patients had 3 untreated aneurysms) had at least one SGB. Patients received up to 4 SGBs, and thus the study comprised a total of 76 SGBs.After the first SGB, CBFV decreased in 80.5% of patients after 2 hours, from a mean of 160.3 ± 28.2 cm/sec to 127.5 ± 34.3 cm/sec (p < 0.001), and it further decreased in 63.4% after 24 hours to 137.2 ± 38.2 cm/sec (p = 0.007). A similar significant effect was found for the subsequent SGB. Adding clonidine showed no significant effect on either the onset or the duration of the SGB. Contralateral middle cerebral artery (MCA) blood flow was not reduced by the SGB.CONCLUSIONSTo the authors’ knowledge, this is the largest study on the effects of administering an SGB to aSAH patients after aneurysm rupture. The data showed a significant reduction in ipsilateral CBFV (MCA 20.5%) after SGB, lasting in about two-thirds of cases for over 24 hours with no major complications resulting from the SGB.


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