Red Blood Cell Aggregation Research Articles

Relationship between capillary blood flow parameters measured in vivo and microrheologic parameters of blood measured in vitro in arterial hypertension and coronary heart disease

Introduction. Blood microcirculation and its microrheologic properties are impaired in cardiovascular diseases. Microrheologic properties are characterized by the red blood cells (RBC) ability to aggregate and disaggregate. Therefore, the correlation studies between RBC aggregation and microcirculation disorders in pathologies are of interest for the development of theoretical concepts related to blood flow and for clinical practice.Aim. To analyze the correlation between capillary blood flow parameters measured in vivo and microrheologic blood parameters measured in vitro in patients suffering arterial hypertension (AH) and coronary heart disease (CHD).Materials and methods. We studied 3 groups of people: patients suffering AH, patients suffering AH+CHD and healthy donors. The characteristic aggregation time and aggregation index were measured in vitro by laser aggregometry. Analysis of capillary blood velocity (CBV) and assessment of the presence and absence of RBC aggregates in the nail bed capillaries were performed in vivo using vital digital capillaroscopy (VDC).Results. RBC aggregation for groups of patients suffering AH and AH+CHD was increased compared to the control group. Thus, in these patients groups, the characteristic aggregation time significantly decreases by an average of (38±13) %. Comparison of the results obtained using in vitro and in vivo methods showed the aggregation index for individuals with high CBV was significantly lower than for individuals with low CBV. The tendency is that the number of aggregates in the capillaries increases with a decrease in CBV.Conclusion. RBC aggregation is increased in groups of patients suffering AH and AH+CHD compared to the control group. The correlation between parameters measured in vitro and in vivo is evident for patients divided into subgroups according to parameters measured using the VDC. The obtained results allow us to conclude that the used methods are applicable in clinical practice.

Влияние доноров газотрансмиттеров (оксида азота, сульфида водорода и монооксида углерода) на микрореологические свойства эритроцитов

Введение. Микрореологические свойства эритроцитов — их деформируемость и агрегация в значительной степени определяют текучесть цельной крови и ее кислородотранспортный потенциал. При этом эритроциты — это клетки-мишени, на которые действуют сигнальные молекулы. Последние могут регуляторно изменять микромеханические свойства эритроцитов и реологию крови в целом. К сигнальным молекулам относятся и газотрансмиттеры (ГТ) — такие соединения, как оксид азота (NO), сульфид водорода (H2S) и монооксид углерода (CO). Доноры ГТ могут быть основой для разработки лекарственных препаратов для коррекции реологических свойств крови. Цель работы: изучение изменений микрореологических характеристик эритроцитов под влиянием доноров трех газотрансмиттеров — NO, H2S и CO. Материалы и методы. Эритроциты и их восстановленные тени инкубировали с нитропруссидом натрия (НПН, 100 мкмоль) — донором NO, гидросульфидом натрия (NaHS, 100 мкмоль) — донором H2S и трикарбонилхлор (глицинат) рутением (II) (CORM-3, 50 мкмоль) — донором СО. После этого регистрировали деформируемость эритроцитов (ИУЭ), их агрегацию (ПАЭ) и вязкость суспензий (ВС). Результаты. Установлено, что под влиянием всех трех доноров ГТ происходят заметные изменения микрореологических характеристик эритроцитов и их теней (в среднем на 13–16%; p < 0,05). Важно заметить, что сдвиги ИУЭ, ПАЭ и ВС под влиянием доноров газотрансмиттеров были сходными по величине, и суммарная разница их микрореологических эффектов на три разных донора ГТ не превышала 3%. Заключение. На основании полученных данных и их анализа можно заключить, что эритроциты качественно и количественно примерно одинаково отвечают на действие трех разных доноров ГТ положительными изменениями их микрореологических характеристик и особенно агрегации, которая снижалась более чем на 30%. Background. Erythrocytes microrheological properties (deformability and aggregation) largely determine the fluidity of whole blood and its oxygen transport potential. At the same time erythrocytes are target cells for signaling molecules acting. The latter can regulate erythrocytes micromechanical properties and blood rheology in general. Signaling molecules also include gasotransmitters (GT) — compounds such as nitrogen oxide (NO), hydrogen sulfide (H2S) and carbon monoxide (CO). GT donors can form the basis of drugs for blood rheology correction. Objectives: to study the changes of erythrocytes microrheological characteristics under the influence of donors of three gasotransmitters — NO, H2S and CO. Materials/Methods. Erythrocytes and their restored shadows were incubated with sodium nitroprusside (SNP, 100 μmol) — NO donor, sodium hydrosulfide (NaHS, 100 μmol) — H2S donor, and with tricarbonylchlor (glycinate) ruthenium (II) (CORM-3, 50 μmol) — CO donor. Thereafter we registered erythrocytes deformability (ED), their aggregation (EA) and suspensions viscosity (SV). Results. All three GT donors noticeably changed microrheological characteristics of erythrocytes and their shadows (on average by 13–16%; p < 0.05). It’s important that the shifts of ED, EA, and SV under the influence of gasotransmitter donors were similar in magnitude, and the total difference in their microrheological effects on three different GT donors did not exceed 3%. Conclusions. Erythrocytes qualitatively and quantitatively approximately equally responded to the action of three different GT donors by positive changes in their microrheological characteristics and especially by aggregation that decreased by more than 30%.

A Molecular Communication Detection Method for the Deformability of Erythrocyte Membrane in Blood Vessels.

Molecular communication (MC) inspired drug delivery holds considerable promise as a new design for targeted therapy with high efficiency and minimal toxicity. The process of drug delivery can be modelled in a blood flow-based MC system, where nanoparticles (NPs) carry therapeutic agents through the blood vessel channels to the targeted diseased tissue. Most previous studies in the flow-based MC consider a Newtonian fluid with a laminar flow, which ignores the influence of red blood cells (RBCs). However, the nature of blood flow is a complex and non-Newtonian fluid composed of proteins, platelets, plasma and deformable cells, especially RBCs. The ability to change their shapes is essential to the proper functioning of RBCs in the microvasculature. Different shapes of RBCs have a great impact on the performance of blood flow. Changes in the properties and shapes of RBCs are often associated with different diseases, such as sickle cell anemia, diabetes, and malaria. Thus, it is highly important to establish a more realistic blood flow MC model considering the deformable cells. According to our previous study, the motion and adhesion of individual NPs are modelled through the Brownian adhesion dynamics. Subsequently, this paper establishes a particle-cell hybrid model in the flow-based MC, which focuses on the RBC deformation, aggregation, and dispersion in the blood suspension. Based on the state of the RBC deformation and aggregation in the vessels with different flow rates, this paper proposes a novel methodology for detecting the deformability of the cells. The blood state in terms of RBC deformability is determined by the difference in NPs' concentration at the receiving end., this paper sheds some light on the influence of RBCs on the motion of NPs, which provides new insights on the design of targeted drug delivery and the detection of vascular diseases.

Microfluidics in Sickle Cell Disease Research: State of the Art and a Perspective Beyond the Flow Problem

Sickle cell disease (SCD) is the monogenic hemoglobinopathy where mutated sickle hemoglobin molecules polymerize to form long fibers under deoxygenated state and deform red blood cells (RBCs) into predominantly sickle form. Sickled RBCs stick to the vascular bed and obstruct blood flow in extreme conditions, leading to acute painful vaso-occlusion crises (VOCs) – the leading cause of mortality in SCD. Being a blood disorder of deformed RBCs, SCD manifests a wide-range of organ-specific clinical complications of life (in addition to chronic pain) such as stroke, acute chest syndrome (ACS) and pulmonary hypertension in the lung, nephropathy, auto-splenectomy, and splenomegaly, hand-foot syndrome, leg ulcer, stress erythropoiesis, osteonecrosis and osteoporosis. The physiological inception for VOC was initially thought to be only a fluid flow problem in microvascular space originated from increased viscosity due to aggregates of sickled RBCs; however, over the last three decades, multiple molecular and cellular mechanisms have been identified that aid the VOC in vivo. Activation of adhesion molecules in vascular endothelium and on RBC membranes, activated neutrophils and platelets, increased viscosity of the blood, and fluid physics driving sickled and deformed RBCs to the vascular wall (known as margination of flow) – all of these come together to orchestrate VOC. Microfluidic technology in sickle research was primarily adopted to benefit from mimicking the microvascular network to observe RBC flow under low oxygen conditions as models of VOC. However, over the last decade, microfluidics has evolved as a valuable tool to extract biophysical characteristics of sickle red cells, measure deformability of sickle red cells under simulated oxygen gradient and shear, drug testing, in vitro models of intercellular interaction on endothelialized or adhesion molecule-functionalized channels to understand adhesion in sickle microenvironment, characterizing biomechanics and microrheology, biomarker identification, and last but not least, for developing point-of-care diagnostic technologies for low resource setting. Several of these platforms have already demonstrated true potential to be translated from bench to bedside. Emerging microfluidics-based technologies for studying heterotypic cell–cell interactions, organ-on-chip application and drug dosage screening can be employed to sickle research field due to their wide-ranging advantages.

Classification of red blood cell aggregation using empirical wavelet transform analysis of ultrasonic radiofrequency echo signals

Grading red blood cell (RBC) aggregation is important for the early diagnosis and prevention of related diseases such as ischemic cardio-cerebrovascular disease, type II diabetes, deep vein thrombosis, and sickle cell disease. In this study, a machine learning technique based on an adaptive analysis of ultrasonic radiofrequency (RF) echo signals in blood is proposed, and its feasibility for classifying RBC aggregation is explored. Using an adaptive empirical wavelet transform (EWT) analysis, the ultrasonic RF signals are decomposed into a series of empirical mode functions (EMFs); then, dominant empirical mode functions (DEMFs) are selected from the series. Six statistical characteristics, including the mean, variance, median, kurtosis, root mean square (RMS), and skewness are calculated for the locally normalized DEMFs, aiming to form primary feature vectors. Random forest (RDF) and support vector machine (SVM) classifiers are trained with the given feature vectors to obtain prediction models for RBC classification. Ultrasonic RF echo signals are acquired from five groups of six types of porcine blood samples with average numbers of aggregated RBCs of 1.04, 1.20, 1.83, 2.31, 2.72, and 4.28, respectively, to test the classification performance of the proposed method. The best subset with regard to the variance, kurtosis, and RMS is determined according to the maximum accuracy based on the RDF and SVM classifiers. The classification accuracies are 84.03 ± 3.13% for the RDF classifier, and 85.88 ± 2.99% for the SVM classifier. The mean classification accuracy of the SVM classifier is 1.85% better than that of the RDF classifier. In conclusion, the machine learning method is useful for the discrimination of varying degrees of RBC aggregation, and has potential for use in characterizing and monitoring the RBC aggregation in vessels.

Erratum: “A constitutive hemorheological model addressing both the deformability and aggregation of red blood cells” [Phys. Fluids 32, 103103 (2020)

Erratum: “A constitutive hemorheological model addressing both the deformability and aggregation of red blood cells” [Phys. Fluids <b>32</b>, 103103 (2020)

Rapid hemostasis accompanied by antibacterial action of calcium crosslinking tannic acid-coated mesoporous silica/silver Janus nanoparticles

It is important to control bleeding and prevent bacterial infection for the wound people. The effective way is to fabricate an asymmetric Janus matrial for realizing rapid hemostasis and promoting wound healing. Herein, mesoporous silica nanoparticles (MSN) modified by tannic acid (TA), silver nanoparticles, and calcium ions (Ca-TA-MSN@Ag) with Janus structure were prepared via redox and coordination reactions. These anisotropic snowman-like particles possess obvious chemical compartition, in which silver nanoparticles are embedding in large MSN body. During blood coagulation, TA with catechol structure acts as a vasoconstrictor. Then, Ca-TA-MSN@Ag with high specific surface area (510.62 m2·g−1) and large pore volume (0.48 m3·g−1) induces red blood cell aggregation to form three-dimensional network structure with fibrin. Additionally, calcium ions as clotting factor IV and negative charge of Ca-TA-MSN@Ag accelerate coagulation cascade reaction. These three synergistic effects on animal model showed that hemostatic time of Ca-TA-MSN@Ag was shortened by nearly 50% compared to that of MSN. Moreover, Ca-TA-MSN@Ag possessed good blood compatibility, biocompatibility and antibacterial activity (~99%) against E. coli and S. aureus. The anisotropic Janus particles of Ca-TA-MSN@Ag with hemostatic performance and antibacterial activity will be a promising biomaterial for designing wound dressings in clinical application.

\u03b2-Dispersion of blood during sedimentation

Aggregation of human red blood cells (RBC) is central to various pathological conditions from bacterial infections to cancer. When left at low shear conditions or at hemostasis, RBCs form aggregates, which resemble stacks of coins, known as ‘rouleaux’. We experimentally examined the interfacial dielectric dispersion of aggregating RBCs. Hetastarch, an RBC aggregation agent, is used to mimic conditions leading to aggregation. Hetastrach concentration is incrementally increased in blood from healthy donors to measure the sensitivity of the technique. Time lapse electrical impedance measurements were conducted as red blood cells form rouleaux and sediment in a PDMS chamber. Theoretical modeling was used for obtaining complex permittivity of an effective single red blood cell aggregate at various concentrations of hetastarch. Time response of red blood cells’ impedance was also studied to parametrize the time evolution of impedance data. Single aggregate permittivity at the onset of aggregation, evolution of interfacial dispersion parameters, and sedimentation kinetics allowed us to distinguish differential aggregation in blood.

Red Blood Cell Morphodynamics: A New Potential Marker in High-Risk Patients.

In the last years, a substantial contribution of red blood cells (RBCs) in cardiovascular homeostasis has been evidenced, as these cells are able to regulate cardiovascular function by the export of adenosine triphosphate and nitric oxide as well as to maintain redox balance through a well-developed antioxidant system. Recently a link between high-risk plaque (HRP) features and myocardial ischemia, in the absence of severe lumen stenosis, has been evidenced. Nonobstructive coronary artery disease (nonob CAD) has been associated in fact with a greater 1-year risk of myocardial infarction and all-cause mortality compared with no apparent CAD. This new evidence increases interest in searching new triggers to identify these high-risk patients, in the absence/or on top of traditional hazard markers. In this study, we investigated the existence of any association between RBC morphodynamics and HRP features in individuals with different grades of coronary stenosis detected by coronary computed tomography angiography (CCTA). Ninety-one consecutive individuals who underwent CCTA [33 no CAD; 26 nonobstructive (nonob), and 32 obstructive (ob) CAD] were enrolled. RBC morphodynamic features, i.e., RBC aggregability and deformability, were analyzed by means of Laser Assisted Optical Rotation Cell Analyzer (LoRRca MaxSis). The putative global RBC morphodynamic (RMD) score and the related risk chart, associating the extent of HRP (e.g., the non-calcified plaque volume) with both the RMD score and the max % stenosis were computed. In nonob CAD group only positive correlations between RBC rigidity, osmotic fragility or aggregability and HRP features (plaque necrotic core, fibro-fatty and fibro-fatty plus necrotic core plaque volumes) were highlighted. Interestingly, in this patient cohort three of these RBC morphodynamic features result to be independent predictors of the presence of non-calcified plaque volume in this patients group. The risk chart created shows that only in nonob CAD plaque vulnerability increases according to the score quartile. Findings of this work, by evidencing the association between erythrocyte morphodynamic characteristics assessed by LoRRca and plaque instability in a high-risk cohort of nonob CAD, suggest the use of these blood cell features in the identification of high-risk patients, in the absence of severe coronary stenosis.

Multimodal Diagnostics of Microrheologic Alterations in Blood of Coronary Heart Disease and Diabetic Patients.

Coronary heart disease (CHD) has serious implications for human health and needs to be diagnosed as early as possible. In this article in vivo and in vitro optical methods are used to study blood properties related to the aggregation of red blood cells in patients with CHD and comorbidities such as type 2 diabetes mellitus (T2DM). The results show not only a significant difference of the aggregation in patients compared to healthy people, but also a correspondence between in vivo and in vitro parameters. Red blood cells aggregate in CHD patients faster and more numerously; in particular the aggregation index increases by 20 ± 7%. The presence of T2DM also significantly elevates aggregation in CHD patients. This work demonstrates multimodal diagnostics and monitoring of patients with socially significant pathologies.

Evaluation method of the degree of red blood cell aggregation considering ultrasonic propagation attenuation by analyzing ultrasonic backscattering properties

Red blood cell (RBC) aggregation is one of the main factors that determines blood viscosity and an important indicator for evaluating blood properties. As a noninvasive and quantitative method for diagnosing blood properties, our research group estimated the size of RBC aggregates by fitting the scattered power spectrum from the blood vessel lumen with the theoretical scattering characteristics to evaluate the degree of RBC aggregation. However, it was assumed that the propagation attenuation of ultrasound in the vascular lumen was the same regardless of whether RBCs were aggregated or not, which caused systematic errors in the estimated size. To improve the size estimation accuracy, we calculated and corrected the attenuation of the blood vessel lumen during RBC aggregation and non-aggregation. The attenuation in the blood vessel lumen was calculated with the spectra acquired from two different depths. In the basic experiments using microparticles, the estimation accuracy decreased as the concentration increased in the case of the conventional method, but the estimated size tended to approach the true size irrespective of the concentration, removing the propagation attenuation component with the proposed method. In the in vivo experiment on the human hand dorsal vein, the size was estimated to be larger during RBC aggregation and smaller during non-aggregation using the proposed method. These results suggest that the proposed method can provide precise size estimation by considering the propagation attenuation component regardless of differences in blood conditions such as RBC concentration and degree of aggregation.

ОСОБЕННОСТИ СОСТОЯНИЯ МИКРОЦИРКУЛЯТОРНОГО РУСЛА И МЕМБРАННОГО ПИЩЕВАРЕНИЯ У НОВОРОЖДЕННЫХ ТЕЛЯТ ПРИ ДИСПЕПСИИ

The scientific article provides information about the study of the features of blood supply, the state of the microcirculatory bed in clinically healthy newborn calves, as well as in the case of their dyspepsia. It was found that in clinically healthy newborn calves, the microcirculatory bed of the conjunctiva of the eyeball is represented by all the links of microcirculation, namely: parallel arterioles and venules that end in the corresponding capillaries, they form a cellular structure on the conjunctiva. In calves with dyspepsia, there are marked changes in the microcirculation of certain areas of the conjunctiva of the eyeball. In this case, microcirculatory disorders are characterized by a change in the shape of the vessels, the unevenness of their caliber, the appearance of ampouleshaped extensions along the course of the vessels, the appearance of constrictions in them. The ratio of the diameter of the venules of the diameter of the arterioles is 1:4, and in healthy calves this ratio is 1:2. Intravascular changes are characterized by the appearance of aggregation of red blood cells (sludge phenomenon) in most vessels of the venular bed, as well as in capillaries and isolated cases in arterioles. Against the background of pronounced disorders in the microcirculatory bed, and as is known, they reflect a systemic circulatory disorder, we conducted parallel studies of membrane digestion, using the example of protein hydrolysis. It was found that in sick calves, there was a decrease in the enzymatic activity of glycyl-L-leucine dipeptidase along the proximal gradient. Thus, in calves with dyspepsia, there is a disorder of blood circulation in general and in the digestive system in particular, which is a determining factor in the occurrence of disorders of membrane digestion, which performs the intermediate and final stages of hydrolysis of nutrients.

3Pa5-1 A method for estimating size of red blood cell aggregates using power spectrum measured from a point scatterer

3Pa5-1 A method for estimating size of red blood cell aggregates using power spectrum measured from a point scatterer

Effect of regulating qi and invigorate blood circulation method on hemorrheology in rats with acute blood stasis syndrome and its network pharmacology research

To observe the effect of regulating qi and invigorate blood circulation method on hemorrheology in rats with acute blood stasis syndrome from the perspective of modern pharmacology, and use network pharmacology to explain its mechanism. Forty male Wistar rats were randomly divided into 6 groups. Except the blank control group, the other groups were injected with adrenaline hydrochloride and ice bath to establish the acute blood stasis syndrome model. Each group were administered Xuefu Zhuyu D ecoction, Jinlingzi Powder, Taohong Siwu Decoction, and Yanhusuo Decoction, and t he blank control group and model control group were given the same volume of saline, respectively. The blood rheology indexes such as red blood cell aggregation index of rats were measured. The TCMSP and Batman database were used to search for chemical components and targets of Jinlingzi Powder, and protein interaction analysis, GO enrichment analysis and KEGG analysis were performed on the common targets. The experimental results show that, compared with the model group, the blood rheology index levels of the Yanhusuo group and Taohong Siwu Decoction group are reduced, while the blood rheology index levels of the Xuefu Zhuyu Decoction group and the Jinlingzi S an group are significantly reduced. The network pharmacology predicts that Jinlingzi Powder has 44 active ingredients and 34 drug-disease shared targets, and KEGG analyzes 61 signaling pathways. Conclusion: IN the case of blood stasis syndrome, the effect of regulating qi with invigorate blood circulation is better than that of regulating qi alone. Network pharmacologic prediction showed that TNF signaling pathway was strongly correlated with hemorheology, and its action pathway was closely related to key tar gets IL6, TNF, CASP3.

Crushing effect of red blood cell aggregation by acoustic pressure and evaluation of cell damages

Crushing effect of red blood cell aggregation by acoustic pressure and evaluation of cell damages

Evaluation of hemorheological parameters as biomarkers of calcium metabolism and insulin resistance in postmenopausal women.

Calcium, vitamin D and insulin resistance are linked to osteoporosis and cardiovascular disease in menopause. Determine if hemorheological parameters related to blood viscosity in microcirculation are linked to calcium metabolism and insulin resistance in menopause. 25-Hydroxyvitamin D (25(OH)D)), 1, 25-dihydroxyvitamin D3 (1, 25(OH)2D), parathyroid hormone, ionized calcium, glucose, insulin and hemoglobin A1c were measured in blood from 43 volunteers. Red blood cells (RBC) aggregation, RBC deformability and whole blood viscosity were also performed. 25(OH)D showed a positive correlation with RBC deformability 0.60 Pa. Subjects with 25(OH)D≤29.00 ng/mL had lower RBC deformability 0.60 Pa, and higher RBC aggregation and higher HOMA-IR. Ionized calcium showed a negative correlation with RBC aggregation. Subjects with ionized calcium ≤1.24 mmol/L showed higher RBC aggregation. There was a positive correlation between HOMA-IR and RBC aggregation and HOMA-IR showed a negative correlation with RBC deformability 0.30 Pa. Subjects with HOMA-IR <1.80 showed lower RBC aggregation and higher RBC deformability at 0.30 Pa, 0.60 Pa, 1.20 Pa, 3.0 Pa and 6.0 Pa. Low 25(OH)D, low ionized calcium and high HOMA-IR are related to impaired hemorheology in menopause. RBC aggregation and deformability can be used as biomarkers of calcium metabolism and insulin resistance in menopause.

Rheologycal Parameters in Patients with Brain Infarct During COVID-19

In the description of the analytical clinical data of the patients with COVID-19 from difference country. In article shows detailed description of the rheological situation in patients with neuropathic during COVID-19. This data was compared with results of rheological study in analogical disease group patients without COVID-19. The article describes the effect of various anticoagulants on blood rheology, also describing protocols. In vivo, in vitro experiments, that studied a range of rheological parameters different anticoagulants. Measurement of RBC aggregation, RBC deformities, plasma viscosity were study with innovative technologies, quantitative methods. The work presents a scientific focus, after deep and increase research area is able to transport the newest conclusion to the clinical practice to treatment management of COVID-19.

Simulated Hypergravity Activates Hemostasis in Healthy Volunteers.

BackgroundHypergravity may promote human hemostasis thereby increasing thrombotic risk. Future touristic suborbital spaceflight will expose older individuals with chronic medical conditions, who are at much higher thromboembolic risk compared with professional astronauts, to hypergravity. Therefore, we tested the impact of hypergravity on hemostasis in healthy volunteers undergoing centrifugation.Methods and ResultsWe studied 20 healthy seated men before and after 15 minutes under 3 Gz hypergravity on a long‐arm centrifuge. We obtained blood samples for hemostasis testing before, immediately after, and 30 minutes after centrifugation. Tests included viscoelastic thromboelastometry, platelet impedance aggregometry, endothelial activation markers, blood rheology testing, microparticle analyses, and clotting factor analysis. Exposure to hypergravity reduced plasma volume by 12.5% (P=0.002) and increased the red blood cell aggregation index (P<0.05). With hypergravity, thrombelastographic clotting time of native blood shortened from 719±117 seconds to 628±89 seconds (P=0.038) and platetet reactivity increased (P=0.045). Hypergravity shortened partial thromboplastin time from 28 (26–29) seconds to 25 (24–28) seconds (P<0.001) and increased the activity of coagulation factors (eg, factor VIII 117 [93–134] versus 151 [133–175] %, P<0.001). Tissue factor concentration was 188±95 pg/mL before and 298±136 pg/mL after hypergravity exposure (P=0.023). Antithrombin (P=0.005), thrombin‐antithrombin complex (P<0.001), plasmin‐alpha2‐antiplasmin complex (0.002), tissue‐plasminogen activatior (P<0.001), and plasminogen activator inhibitor‐1 (P=0.002) increased with centrifugation. Statistical adjustment for plasma volume attenuated changes in coagulation.ConclusionsHypergravity triggers low‐level hemostasis activation through endothelial cell activation, increased viscoelasticity, and augmented platelet reactivity, albeit partly counteracted through endogenous coagulation inhibitors release. Hemoconcentration may contribute to the response.

Investigation of Hemostasis Using Plantain Sheath/Stem, Cassava Leaf and Snail Juices in Human Blood in-vitro

Inhabitants of most rural communities of West Africa have limited health care facilities and walk long distances to seek medical attention when injured. This sometimes lead to loss of blood and death. To minimize loss of blood from injured individuals by clot formation, juices from plantain sheath/stem, cassava leaf and snail are applied on injured areas. The present work therefore investigated Musa paradisiaca sheath/stem, Manihot essculanta leaf and Achatina marginata juices for hemostatic property using human blood in-vitro. Screening indicated these juices contain tannins, flavonoids and other secondary metabolites. Morphological studies showed formation of a protein network on adding each of the three juices to fresh whole blood, plasma and serum respectively. The protein network formed was as a result of interactions between tannins found in the juices and proteins in the blood components. Microscopic analysis revealed aggregation of red blood cells as each of the juices was added to whole blood. High molecular weight fibrinogen found in whole blood, could have been caused by tannins and flavonoids found present in the juices. Insoluble proteins increased blood viscosity and inhibited movement of the red blood cells. Coagulatory potencies expressed in Prothrombin Times (PTs), revealed the snail juice of 0.80 mL volume had the least time for clot formation (PT=10.02 seconds), and indicated its hemostatic property. This PT was lesser compared to that of the standard, liquid plastin (PT= 11.0-12.5 seconds). As volumes of the three juices were increased from 0.8 to 1.0 mL, their PTs correspondingly decreased (p< 0.05). The snail juice of 0.9 mL volume had the least PT of 8.52 seconds. The plantain stem juice of 0.9 mL volume was next to the snail juice in order of ranking with a PT of 10.79 seconds, and lastly the cassava leaf juice of 1.0 mL volume with a PT of 14.42 seconds. Comparatively, the PTs for the plantain stem and snail juices were the same as the PT for the liquid plastin (PT=11.0 to 12.5 seconds, p<0.050), and all the three juices had PTs within the range considered for substances to be hemostatic (≤ 20.0 seconds). This demonstrated an increased in hemostasis as volumes of the juices were increased, and therefore the plantain stem, cassava leaf and snail juices possess hemostatic property. A blend of the plantain stem and snail juices (1:1) revealed a lesser PT of 18.20 seconds compared to the PT of ≤ 20.0 seconds considered for hemostatic substances. Thus the plantain stem, cassava leaf and snail juices, and the blend of the plantain stem and snail juices (1:1) investigated in the present research work demonstrated hemostasis, and possess hemostatic property. This scientific evidence supports the use of plantain stem, cassava leaf and snail juices as hemostatic substances.

Development of a Surface-Functionalized Titanium Implant for Promoting Osseointegration: Surface Characteristics, Hemocompatibility, and In Vivo Evaluation

This study aimed to evaluate the impact of surface-modified biomedical titanium (Ti) dental implant on osseointegration. The surfaces were modified using an innovative dip-coating technique (IDCT; sandblasted, large-grit, and acid-etched, then followed by coating with the modified pluronic F127 biodegradable polymer). The surface morphology and hemocompatibility evaluations were investigated by field-emission scanning electron microscopy, while the contact analysis was observed by goniometer. The IDCT-modified Ti implant was also implanted in patients with missing teeth by single-stage surgical procedure then observed immediately and again four months after placement by cone-beam computerized tomography (CBCT) imaging. It was found that the IDCT-modified Ti implant was rougher than the dental implant without surface modification. Contact angle analysis showed the IDCT-modified Ti implant was lower than the dental implant without surface modification. The hemocompatibility evaluations showed greater red blood cell aggregation and fibrin filament formation on the IDCT-modified Ti implant. The radiographic and CBCT image displayed new bone formation at four months after the IDCT-modified Ti implant placement. Therefore, this study suggests that the IDCT-modified Ti dental implant has great potential to accelerate osseointegration.