Characterization of cerebral blood flow dynamics with multiscale entropy

Based on the laser speckle contrast imaging (LSCI) and the multiscale entropy (MSE), we study in this work the blood flow dynamics at the levels of cerebral veins and the surrounding network of microcerebral vessels. We discuss how the phenylephrine-related acute peripheral hypertension is reflected in the cerebral circulation and show that the observed changes are scale-dependent, and they are significantly more pronounced in microcerebral vessels, while the macrocerebral dynamics does not demonstrate authentic inter-group distinctions. We also consider the permeability of blood–brain barrier (BBB) and study its opening caused by sound exposure. We show that alterations associated with the BBB opening can be revealed by the analysis of blood flow at the level of macrocerebral vessels

The laser technologies of targeted opening of blood-brain barrier for drug brain delivery

Here we show the photodynamic treatmen

Abstracts from the 20th International Symposium on Signal Transduction at the Blood-Brain Barriers

https://deepblue.lib.umich.edu/bitstream/2027.42/138963/1/12987_2017_Article_71.pd

The interaction between the meningeal lymphatics and blood-brain barrier

Here we show the interaction between the meningeal lymphatic system and the blood-brain barrier (BBB) function. In normal state, the meningeal lymphatic vessels are invisible on optical coherent tomography (OCT), while during the opening of the BBB, meningeal lymphatic vessels are clearly visualized by OCT in the area of cerebral venous sinuses. These results give a significant impulse in the new application of OCT for the study of physiology of meningeal lymphatic system as well as sheds light on novel strategies in the prognosis of the opening of the BBB related with many central nervous system diseases, such as stroke, brain trauma, Alzheimers disease, etc

ТИПЫ АДАПТАЦИИ ВЕГЕТАТИВНОЙ НЕРВНОЙ СИСТЕМЫ У БОЛЬНЫХ АРТЕРИАЛЬНОЙ ГИПЕРТЕНЗИЕЙ: КЛИНИКО- ЭХОКАРДИОГРАФИЧЕСКИЕ КОРРЕЛЯЦИИ

Methods. 152 patients (age 59.5 [55,5-63] years, 104 men, 48 women) with arterial hypertension were included in the study. All patients underwent echocardiography, the assessment of intima-media thickness, cardiointervalography at rest and during active orthostatic test (AOT) with the further assessment of adaptation with the ORTO expert diagnostic system. All patients were divided into three groups according to the obtained results: Group 1 consisted of patients with high adaptation (n = 24), Group 2 patients with altered adaptation mechanisms (n = 66), Group 3 patients with poor adaptation (n = 62).Results. A 9.5% increase in the intima-media thickness has been found in Group 3 compared to the other study groups (p = 0.0075). Very low frequency power in Group 3 was higher than in Group 1 (p = 0.02). The Et / At ratio in Group 2 and Group 3 was higher compared with Group 1 (p = 0.003). Univariate logistic regression analysis reported the probability of failure of the adaptation mechanisms with increased IMT> 0.9 mm (p = 0.01), Et / At ratio > 1.4 (p = 0.0004) and Et > 60 cm / sec (p = 0.009). Multiple logistic regression reported similar results.Conclusion. High adaptation was found in 16% of patients with hypertension, stress-altered adaptation mechanisms were observed in 43%, and poor adaptation in 41% of patients. Poor adaptation was associated with increased IMT and predominance of very low frequency in the spectral analysis of heart rate variability as well as with values of the right ventricular diastolic function.Цель  исследования.  Изучение   распространенности  и  клинических  корреляций  различных  типов адаптации вегетативной нервной системы у больных артериальной гипертензией (АГ).Материал  и  методы. В  исследование  включено 152   больных   артериальной   гипертензией   (возраст 59,5 [55,5-63] лет; 104 мужчин, 48 женщин). Всем пациентам  выполнена  эхокардиография,  оценка  комплекса   интима-медиа   (КИМ),   а   также   проведена кардиоинтервалография в покое и при активной ор- тостатической пробе (АОП) с оценкой типа адаптации при помощи диагностической системы ORTO eТКeМО. По ее результатам выделены: 1-я группа - с удовлетворительной адаптацией (И—24), 2-я группа - с напряжением механизмов адаптации (И—66), 3-я группа - с неудовлетворительной адаптацией (И—62).Результаты. В 3-й группе отмечено достоверное увеличение КИМ на 9,5% по сравнению с остальными пациентами  (р—0,0075).  Мощность  диапазона  очень низких частот VLF в 3-й группе была выше, чем в 1-й(р—0,02). Отношение Ет/Ат во 2-й и 3-й группах было выше по сравнению с 1-й группой (р—0,003). При однофакторном логистическом регрессионном анализе вероятность срыва механизмов адаптации возрастала с увеличением толщины КИМ‘0,9 мм (р—0,01), при увеличении отношения Ет/Ат ≥  1,4 (р—0,0004) и увеличение показателя Ет ≥60 см/сек (р—0,009). Эти же фак- торы сохранили свою значимость и при множествен- ной логистической регрессии.Заключение.   Удовлетворительный   тип    адап- тации  был  выявлен  у  16%  больных  АГ, напряжение механизмов  адаптации  наблюдалось у  43%, неудовлетворительная адаптация отмечена у 41% больных. Неадекватный  тип  адаптации  был  ассоциирован  с утолщением  КИМ  и  с  преобладанием  очень  низких частот при спектральном анализе ВРС, а также с параметрами диастолической функции правого желудочка сердца

The interaction between the meningeal lymphatics and blood-brain barrier

Here we show the interaction between the meningeal lymphatic system and the blood-brain barrier (BBB) function. In normal state, the meningeal lymphatic vessels are invisible on optical coherent tomography (OCT), while during the opening of the BBB, meningeal lymphatic vessels are clearly visualized by OCT in the area of cerebral venous sinuses. These results give a significant impulse in the new application of OCT for the study of physiology of meningeal lymphatic system as well as sheds light on novel strategies in the prognosis of the opening of the BBB related with many central nervous system diseases, such as stroke, brain trauma, Alzheimers disease, etc

Detection of melanoma cells in whole blood samples using spectral imaging and optical clearing

Most cancer deaths are associated with metastases resulting from the spread of circulating tumor cells (CTCs) from the primary tumor to vital organs. The existing methods for detection of CTCs as markers of metastasis progression are time consuming with several steps of sample processing, including red blood cell removal, labeling, immunomagnetic capture and isolation, which can lead to loss of CTCs. Here we introduce a method for detection and identification of CTCs using spectral absorption imaging of melanoma cells and optical clearing of whole blood samples. Verification of this approach was performed using phantoms of human melanoma cells and suspensions of mouse melanoma cells of line B16F10 alone and in mixture with blood. A method for improving detection sensitivity has been demonstrated applying optical clearing of mouse blood using biocompatible chemical agents. The findings suggest that the proposed diagnostic platform has the potential to detect quickly CTCs in whole blood samples from patients with melanoma

Target delivery of drug carriers in mice kidney glomeruli via renal artery. Balance between efficiency and safety

Targeting drug delivery systems is crucial to reducing the side effects of therapy. However, many of them are lacking effectiveness for kidney targeting, due to systemic dispersion and accumulation in the lungs and liver after intravenous administration. Renal artery administration of carriers provides their effective local accumulation but may cause irreversible vessel blockage. Therefore, the combination of the correct administration procedure, suitable drug delivery system, selection of effective and safe dosage is the key to sparing local therapy. Here, we propose the 3-μm sized fluorescent capsules based on poly-L-arginine and dextran sulfate for targeting the kidney via a mice renal artery. Hemodynamic study of the target kidney in combination with the histological analysis reveals a safe dose of microcapsules (20 × 106), which has not lead to irreversible pathological changes in blood flow and kidney tissue, and provides retention of 20.5 ± 3% of the introduced capsules in the renal cortex glomeruli. Efficacy of fluorescent dye localization in the target kidney after intra-arterial administration is 9 times higher than in the opposite kidney and after intravenous injection. After 24 h microcapsules are not observed in the target kidney when the safe dose of carriers is being used but a high level of fluorescent signal persists for 48 h indicating that fluorescent cargo accumulation in tissues. Injection of non-safe microcapsule dose leads to carriers staying in glomeruli for at least 48 h which has consequences of blood flow not being restored and tissue damage being observed in histology