Blood Cell Morphology Research Articles

Cardiopulmonary bypass in a rat model may shorten the lifespan of stored red blood cells by activating caspase-3.

Red blood cell transfusion is required for many types of surgery against cardiovascular disease, and the function of transfused cells appears to decline over time. The present study examined whether transfusion also reduces red blood cell lifespan in a rat model. Bypass in rats were established by connecting a roll pump to the femoral artery and vein. Then FITC-labeled stored red blood cells from rats were transfused in the animals, and the cells in circulation were counted after transfusion. In separate experiments, stored red blood cells were incubated with bypass plasma in vitro, and the effects of incubation were assessed on cell morphology, redox activity, ATP level, caspase-3 activity, and phosphatidylserine exposure on the cell surface. These in vivo and in vitro experiments were also performed after pretreating the stored red blood cells with the caspase-3 inhibitor Z-DEVD-FMK. Bypass significantly decreased the number of circulating FITC-labeled stored red blood cells and increased the proportions of monocytes, neutrophils and splenic macrophages that had phagocytosed the red blood cells. In vitro, bypass plasma altered the morphology of red blood cells and increased oxidative stress, caspase-3 activity and phosphatidylserine exposure, while decreasing ATP level. Pretreating stored red blood cells with Z-DEVD-FMK attenuated the effects of bypass on caspase-3 activity, but not oxidative stress, in stored red blood cells. Bypass appears to shorten the lifespan of stored red blood cells, at least in part by activating caspase-3 in the cells.

A genome-wide association study of blood cell morphology identifies cellular proteins implicated in disease aetiology

Blood cells contain functionally important intracellular structures, such as granules, critical to immunity and thrombosis. Quantitative variation in these structures has not been subjected previously to large-scale genetic analysis. We perform genome-wide association studies of 63 flow-cytometry derived cellular phenotypes—including cell-type specific measures of granularity, nucleic acid content and reactivity—in 41,515 participants in the INTERVAL study. We identify 2172 distinct variant-trait associations, including associations near genes coding for proteins in organelles implicated in inflammatory and thrombotic diseases. By integrating with epigenetic data we show that many intracellular structures are likely to be determined in immature precursor cells. By integrating with proteomic data we identify the transcription factor FOG2 as an early regulator of platelet formation and α-granularity. Finally, we show that colocalisation of our associations with disease risk signals can suggest aetiological cell-types—variants in IL2RA and ITGA4 respectively mirror the known effects of daclizumab in multiple sclerosis and vedolizumab in inflammatory bowel disease.

Avian Erythrocytes and Agranulocytes - a Review

This study reports on the morphology of red blood cells and agranulocytes in various types of birds, such as rheas, emus, ostriches, chickens, and geese. Though all of them have the typical avian similarity in blood cells, yet there are some differences. Along with normal and mature erythrocytes, lymphocytes, and monocytes, the present study also focuses on rubricytes, reticulocytes, poikilocytes, polychromatophilic erythrocytes, reactive lymphocytes, pleomorphic monocyte nuclei, etc.

Computational analysis of peripheral blood smears detects disease-associated cytomorphologies

Many hematological diseases are characterized by altered abundance and morphology of blood cells and their progenitors. Myelodysplastic syndromes (MDS), for example, are a group of blood cancers characterised by cytopenias, dysplasia of hematopoietic cells and blast expansion. Examination of peripheral blood slides (PBS) in MDS often reveals changes such as abnormal granulocyte lobulation or granularity and altered red blood cell (RBC) morphology; however, some of these features are shared with conditions such as haematinic deficiency anemias. Definitive diagnosis of MDS requires expert cytomorphology analysis of bone marrow smears and complementary information such as blood counts, karyotype and molecular genetics testing. Here, we present Haemorasis, a computational method that detects and characterizes white blood cells (WBC) and RBC in PBS. Applied to over 300 individuals with different conditions (SF3B1-mutant and SF3B1-wildtype MDS, megaloblastic anemia, and iron deficiency anemia), Haemorasis detected over half a million WBC and millions of RBC and characterized their morphology. These large sets of cell morphologies can be used in diagnosis and disease subtyping, while identifying novel associations between computational morphotypes and disease. We find that hypolobulated neutrophils and large RBC are characteristic of SF3B1-mutant MDS. Additionally, while prevalent in both iron deficiency and megaloblastic anemia, hyperlobulated neutrophils are larger in the latter. By integrating cytomorphological features using machine learning, Haemorasis was able to distinguish SF3B1-mutant MDS from other MDS using cytomorphology and blood counts alone, with high predictive performance. We validate our findings externally, showing that they generalize to other centers and scanners. Collectively, our work reveals the potential for the large-scale incorporation of automated cytomorphology into routine diagnostic workflows.

Quantitative Determination of Surface Morphology of Red Blood Cell

In this study, the determination of the surface morphology of red blood cell (RBC) from interferogram image obtained by quantitative phase imaging (QPI) method is presented. QPI, is an optical measurement method frequently used in recent years, allows to obtain quantitative data for different samples (cell, thin film surface, etc.). Many measurement setups at the micrometer level and with nanometer precision have been designed for quantitative surface determination. Among these, white light diffraction phase microscopy (WDPM) is a design that combines the advantages of off-axis holography-specific speed and phase sensitivity associated with common path interferometry. Interferogram image of RBCs have been formed by the WDPM setup. Analysis of this image has been carried out by Fourier transform. As a result of this analysis, three-dimensional (3D), dynamic (observable from all angles) and height-known profiles of RBCs have been created. From the height profiles, the parameters related to the morphology of RBCs as the projected surface area (PSA), diameter (D), mean corpuscular volume (MCV) and total surface area occupied by the cell (SA), have been determined quantitatively. In addition, two-dimensional images, obtained by examining blood samples with light microscopy and scanning electron microscopy (SEM), have been compared with the data achieved by WDPM. The advantages and disadvantages of WDPM and light microscopy and SEM, which are commonly used in biomedical measurements, are discussed through the results. In this way, it was possible to see the difference between QPI and traditional methods used to imaging the cell surface.

RedTell: an AI tool for interpretable analysis of red blood cell morphology.

Introduction: Hematologists analyze microscopic images of red blood cells to study their morphology and functionality, detect disorders and search for drugs. However, accurate analysis of a large number of red blood cells needs automated computational approaches that rely on annotated datasets, expensive computational resources, and computer science expertise. We introduce RedTell, an AI tool for the interpretable analysis of red blood cell morphology comprising four single-cell modules: segmentation, feature extraction, assistance in data annotation, and classification. Methods: Cell segmentation is performed by a trained Mask R-CNN working robustly on a wide range of datasets requiring no or minimum fine-tuning. Over 130 features that are regularly used in research are extracted for every detected red blood cell. If required, users can train task-specific, highly accurate decision tree-based classifiers to categorize cells, requiring a minimal number of annotations and providing interpretable feature importance. Results: We demonstrate RedTell's applicability and power in three case studies. In the first case study we analyze the difference of the extracted features between the cells coming from patients suffering from different diseases, in the second study we use RedTell to analyze the control samples and use the extracted features to classify cells into echinocytes, discocytes and stomatocytes and finally in the last use case we distinguish sickle cells in sickle cell disease patients. Discussion: We believe that RedTell can accelerate and standardize red blood cell research and help gain new insights into mechanisms, diagnosis, and treatment of red blood cell associated disorders.

Morphologic appearance of peripheral blood cells from Zovawk pigs (Sus scrofa domesticus) visualized by transmission electron microscopy.

Ultrastructural information regarding the peripheral blood cells of local (Zovawk) pigs from Mizoram, India, is not available in the scientific literature. The present study was designed to reveal the fine structural details of the blood cells from these local pigs using a transmission electron microscope (TEM). Blood samples were collected from 12 healthy Zovawk pigs of either sex and processed according to a standard protocol. Processed blood samples were then sent to the All India Institute of Medical Sciences, New Delhi, for further processing and imaging under TEM. Different types of blood cells were viewed under TEM, and different characteristics of these cells were assessed. In the present study, erythrocytes are elongated, biconcave, and nucleated without cytoplasmic organelles. Neutrophils are round with 2-5 lobed nuclei surrounded by cytoplasm with an indistinct bilayered nuclear membrane. The cytoplasm is packed with membrane bound round, oval, and elongated cytoplasmic granules. Eosinophils areround to oval with 2-3 lobed nuclei with distinct nuclear membranes. Basophils are spherical and contained small, medium, and large electron-dense granules. Lymphocytes are small, medium, and large and contained all cellular components. Monocytes are irregularly spherical with slight nuclear indentations. The platelets are elongated, oval, or rounded, with a few pseudopods at the cell surface. From the present study, we can conclude that the ultrastructural morphology of blood cells from Zovawk pigs resembles those of other domestic animals. However, a few differences have been observed.

Computer vision quantitation of erythrocyte shape abnormalities provides diagnostic, prognostic, and mechanistic insight

AbstractExamination of red blood cell (RBC) morphology in peripheral blood smears can help diagnose hematologic diseases, even in resource-limited settings, but this analysis remains subjective and semiquantitative with low throughput. Prior attempts to develop automated tools have been hampered by their poor reproducibility and limited clinical validation. Here, we present a novel, open-source machine-learning approach (denoted as RBC-diff) to quantify abnormal RBCs in peripheral smear images and generate an RBC morphology differential. RBC-diff cell counts showed high accuracy for single-cell classification (mean AUC, 0.93) and quantitation across smears (mean R2, 0.76 compared with experts, interexperts R2, 0.75). RBC-diff counts were concordant with the clinical morphology grading for 300 000+ images and recovered the expected pathophysiologic signals in diverse clinical cohorts. Criteria using RBC-diff counts distinguished thrombotic thrombocytopenic purpura and hemolytic uremic syndrome from other thrombotic microangiopathies, providing greater specificity than clinical morphology grading (72% vs 41%; P < .001) while maintaining high sensitivity (94% to 100%). Elevated RBC-diff schistocyte counts were associated with increased 6-month all-cause mortality in a cohort of 58 950 inpatients (9.5% mortality for schist. >1%, vs 4.7% for schist; <0.5%; P < .001) after controlling for comorbidities, demographics, clinical morphology grading, and blood count indices. RBC-diff also enabled the estimation of single-cell volume-morphology distributions, providing insight into the influence of morphology on routine blood count measures. Our codebase and expert-annotated images are included here to spur further advancement. These results illustrate that computer vision can enable rapid and accurate quantitation of RBC morphology, which may provide value in both clinical and research contexts.

Improving White Blood Cell Morphology Education Through Standardized Questions

Medical laboratory scientists routinely evaluate blood smears in the clinical laboratory. A high level of skill in white blood cell morphology is required to do the task quickly and accurately. Educational approaches to teaching white blood cell morphology consist of showing examples of cells to students and allowing them to practice using trial and error to hone their skills. Student progress with this traditional approach is often quite slow. In order to expedite the learning process, we created a series of questions that can guide morphological identification; these questions focus on the shape and description of the nucleus, cytoplasm, granules and cell overall. We hypothesized that white blood cells can be accurately and uniformly identified using the criteria we’ve outlined. We confirmed the accuracy of this approach to white blood cell identification using a random forest classifier algorithm on a data set of 3600 cells that we had previously categorized. Our approach has the potential to standardize white blood cell morphology training in undergraduate medical laboratory scientist programs, and could help improve the consistency of manual differential results between hospital laboratories. This work is funded by a Teaching Development Grant from the Brigham Young University College of Life Sciences This is the full abstract presented at the American Physiology Summit 2023 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.

Biocompatibility of magnetic nanoparticles synthesized through green routed with a focus on hematological and histological analysis

The interaction of metal nanoparticles (MNPs) with blood cells and tissues is essential from the perspectives of biocompatibility and the production of novel drug delivery systems. In the present study, biosynthesized-Fe3O4 nanoparticles (bio-Fe3O4 NPs) were prepared and bio-modified using Daphne mucronata Royle leaf extracts. The physicochemical properties of bio-Fe3O4 NPs were determined using UV–Visible spectroscopy, Energy-dispersive X-ray spectroscopy (EDX), X-ray powder diffraction (XRD), dynamic light scattering (DLS), and Fourier transform infrared (FT‐IR) analyses. According to the SEM analysis, the bio-Fe3O4 NPs are spherical-shaped with a size range of 10–30 nm. Antibacterial effects of bio-Fe3O4 NPs against Staphylococcus aureus ATCC 43300 and Pseudomonas aeruginosa ATCC 27853 bacteria were measured by minimum inhibition/bactericidal concentrations (MIC and MBC tests). Result showed that the bio-Fe3O4 NPs (300 ppm) revealed highest antibacterial effect on S. aureus ATCC 43300. Also, bio-Fe3O4 NPs have different cell viability in the human breast cancer cell line (MCF-7) and mouse embryonic fibroblast (MEF). The interaction of bio-Fe3O4 NPs with blood cells and the complete blood count (CBC) factor illustrated that the morphology of blood cells and platelet clumping did not influence by nanoparticles. Furthermore, histological analysis of the liver, spleen, and kidney did not show any abnormality upon exposure to 100 mg kg−1 bio-Fe3O4 NPs treated samples. Hence, the biosynthesized Fe3O4 NPs are a good candidate for applications in medical fields.

Membrane Lesions and Reduced Life Span of Red Blood Cells in Preeclampsia as Evidenced by Atomic Force Microscopy.

Preeclampsia (PE) presents with maternal de novo hypertension and significant proteinuria and is one of the leading causes of maternal and perinatal morbidity and mortality with unknown etiology. The disease is associated with inflammatory vascular response and severe red blood cell (RBC) morphology changes. This study examined the nanoscopic morphological changes of RBCs from PE women versus normotensive healthy pregnant controls (PCs) and non-pregnant controls (NPCs) applying atomic force microscopy (AFM) imaging. The results revealed that the membrane of fresh PE RBCs differed significantly from healthy ones by the presence of invaginations and protrusions and an increased roughness value (Rrms) (4.7 ± 0.8 nm for PE vs. 3.8 ± 0.5 nm and 2.9 ± 0.4 nm for PCs and NPCs, respectively). PE-cells aging resulted in more pronounced protrusions and concavities, with exponentially increasing Rrms values, in contrast to the controls, where the Rrms parameter decreased linearly with time. The Rrms, evaluated on a 2 × 2 µm2 scanned area, for senescent PE cells (13 ± 2.0 nm) was significantly higher (p < 0.01) than that of PCs (1.5 ± 0.2 nm) and NPCs (1.9 ± 0.2 nm). Furthermore, the RBCs from PE patients appeared fragile, and often only ghosts were observed instead of intact cells at 20-30 days of aging. Oxidative-stress simulation on healthy cells led to RBC membrane features similar to those observed for PE cells. The results demonstrate that the most pronounced effects on RBCs in PE patients are related to impaired membrane homogeneity and strongly altered roughness values, as well as to vesiculation and ghost formation in the course of cell aging.

Autosomal Recessively Inherited Glucose Transporter-1 Deficiency Syndrome with Acanthocytosis: A Case Report

AbstractGlucose transporter-1 deficiency syndrome (GLUT-1DS) is a rare, autosomal dominantly inherited disorder due to a heterozygous mutation in the gene solute channel 2A1 (SLC2A1).This gene encodes the glucose transporter protein-1. Autosomal recessive inheritance is extremely rare. Similarly, only very few reports are found in the literature of hematological manifestations in this syndrome. We report an autosomal recessively inherited GLUT-1DS, due to a de novo mutation, with the classical infantile presentation associated with concomitant acanthocytosis. In this case report, the second child born to consanguineous parents with initial refractory neonatal seizures and subsequent poorly controlled epilepsy and developmental regression is discussed. The most notable investigation findings supportive of his underlying diagnosis were very low cerebrospinal fluid (CSF) glucose and CSF lactate levels. His CSF:plasma glucose ratio was 1:7.6. He was anemic with a hemoglobin of 8.8 g/dL with his blood film showing marked acanthocytosis. His elder brother who also had refractory epilepsy and developmental regression had similar hypoglycorrhachia, low CSF:plasma glucose ratio, and mild anemia with acanthocytosis, and he died before establishment of a diagnosis. Our patient was diagnosed to have a novel mutation SLC2A1 c.184A &gt; G p.(Thr62Ala), for which both parents were heterozygous, confirming autosomal recessive inheritance. Commencement of a ketogenic diet resulted in improvement of his seizures and slow gain in development. It also resulted in gradual disappearance of acanthocytes from his peripheral blood. This case describes a rare case of classical GLUT-1DS, autosomal recessively inherited, due to a novel mutation. The acanthocytosis in his blood smear is another rare association minimally reported in GLUT-1DS. The cause of his abnormal red blood cell morphology is unclear. It is possibly related to cation leakage reported in some rare mutations of the SLC2A1 gene needs reference.

Practical Clinical Consensus Guidelines for the Management of Cancer Associated Anemia in Low- and Middle-Income Countries.

Purvish M. ParikhCancer-associated anemia (CAA) remains a major unmet need that compromises overall survival (OS) and quality of life (QoL). Currently, available guidelines do not take into consideration the unique challenges in low- and middle-income countries (LMIC). Our CAA patients have to battle preexisting impaired nutritional status, depleted body iron stores, financial limitations, and difficulty in having easily accessible affordable healthcare. Hence, we fulfilled the need of guidelines for LMIC. A group of subject experts were put together, given background literature, met in a face-to-face discussion, voted using Delphi process, and finally agreed on the contents of this guideline document. As many as 50% of cancer patients will have significant anemia (hemoglobin < 10 g/dL) at initial diagnosis. It is most commonly seen with gastrointestinal malignancies, head and neck cancers, and acute leukemias. The hemoglobin falls further after initiation of cancer directed therapy, due to chemotherapy itself or heightened nutritional deficiency. Its evaluation should include tests for complete blood count, red blood cell morphology, reticulocyte count, Coombs test, and levels of vitamin B12 and folic acid. Iron status should be monitored using test to measure serum iron, total iron binding capacity, transferring saturation, and serum ferritin levels. A minimum of 50% of cancer patients with anemia require iron supplements. The preferred mode of therapy is with intravenous (IV) iron using ferric carboxymaltose (FCM). Most patients respond satisfactorily to single dose of 1000 mg. It is also safe and does not require use of a test dose. Significant anemia is found in at least half of all cancer patients in India, South Asian Association for Regional Cooperation region, and other LMIC countries. Its awareness among healthcare professionals will prevent it from remaining undiagnosed (in up to 70% of all cancer patients) and adversely affecting OS and QoL. The benefits of treating them with IV iron therapy are quick replenishment of iron stores, hemoglobin returning to normal, better QoL, and avoiding risk of infections/reactions with blood transfusions. Many publications have proven the value of single-dose FCM in such clinical situations. CAA has been proven to be an independent prognostic factor that adversely affects both QoL and OS in cancer patients. Use of FCM as single IV dose of 1000 mg is safe and effective in the majority of patients with CAA.

Artificial Intelligence-based online platform assists blood cell morphology learning: A mixed-methods sequential explanatory designed research

Background The study aimed to evaluate the effectiveness of learning blood cell morphology by learning on our Artificial intelligence (AI)-based online platform. Methods Our study is based on mixed-methods sequential explanatory design and crossover design. Thirty-one third-year medical students were randomly divided into two groups. The two groups had platform learning and microscopy learning in diferent sequences with pretests and posttests, respectively. Students were interviewed, and the records were coded and analyzed by NVivo 12.0. Results For both groups, test scores increased significantly after online-platform learning. Feasibility was the most mentioned advantage of the platform. The AI system could inspire the students to compare the similarities and differences between cells and help them understand the cells better. Students had positive perspectives on the online-learning platform. Conclusion The AI-based online platform could assist medical students in blood cell morphology learning. The AI system could function as a more knowledgeable other (MKO) and guide the students through their zone of proximal development (ZPD) to achieve mastery. It could be an effective and beneficial complement to microscopy learning. Students had very positive perspectives on the AI-based online learning platform. It should be integrated into the course and curriculum to facilitate the students. Practice points The AI-based online platform could assist medical students in blood cell morphology learning. The AI system could function as an MKO and guide the students through their ZPD to achieve mastery. The AI-based online platform could be an effective and beneficial complement to microscopy learning. The AI-based online platform should be integrated into the curriculum to facilitate the students.

Mechanochemical Synergism of Reactive Oxygen Species Influences on RBC Membrane.

The influences of various factors on blood lead to the formation of extra reactive oxygen species (ROS), resulting in the disruption of morphology and functions of red blood cells (RBCs). This study considers the mechanisms of the mechanochemical synergism of OH• free radicals, which are most active in the initiation of lipid peroxidation (LPO) in RBC membranes, and H2O2 molecules, the largest typical diffusion path. Using kinetic models of differential equations describing CH2O2t and COH•t, we discuss two levels of mechanochemical synergism that occur simultaneously: (1) synergism that ensures the delivery of highly active free radicals OH• to RBC membranes and (2) a positive feedback system between H2O2 and OH•, resulting in the partial restoration of spent molecules. As a result of these ROS synergisms, the efficiency of LPO in RBC membranes sharply increases. In blood, the appearance of OH• free radicals is due to the interaction of H2O2 molecules with free iron ions (Fe2+) which arise as a result of heme degradation. We experimentally established the quantitative dependences of COH• CH2O2 using the methods of spectrophotometry and nonlinear curve fitting. This study extends the analysis of the influence of ROS mechanisms in RBC suspensions.

Validation of the International Consensus Group Criteria for Slide Review Following Automated Complete Blood Count at Jimma Medical Center, Ethiopia.

The international consensus group suggested criteria for action following automated complete blood count and white blood cell differential analysis. These criteria were set based on data from laboratories of developed countries. It is highly important to validate the criteria in developing countries where infectious diseases are still rampant that can affect blood cell count and morphology. Thus, this study aimed to validate the consensus group criteria for slide review at Jimma Medical Center, Ethiopia from November 1, 2020 to February 30, 2021. The study comprised a total of 1685 patient samples from the daily laboratory workload of CBC analysis. The samples were collected in K2-EDTA tubes (Becton Dickinson) and analyzed using Coulter DxH 800 and Sysmex XT-1880 hematology analyzers. A slide review was done on two Wright-stained slides for each sample. All statistical analyses were performed using SPSS version 20 software. There were 39.8% positive findings, the majority of which were related to red blood cells. The false negative and false positive rates for Sysmex and Coulter analyzer were 2.4% vs 4.8%; and 4.6% vs 4.7%, respectively. The false negative rate was unacceptably higher when we used physicians' triggered slide review, which was 17.3% and 17.9% for Sysmex and Coulter analyzers, respectively. Generally, the consensus group rules are suitable to use in our setting. However, we might still need to modify the rules, particularly to reduce the review rates. It is also necessary to confirm the rules with case mixes proportionally derived from the source population.

Deep ensemble learning enables highly accurate classification of stored red blood cell morphology

Changes in red blood cell (RBC) morphology distribution have emerged as a quantitative biomarker for the degradation of RBC functional properties during hypothermic storage. Previously published automated methods for classifying the morphology of stored RBCs often had insufficient accuracy and relied on proprietary code and datasets, making them difficult to use in many research and clinical applications. Here we describe the development and validation of a highly accurate open-source RBC morphology classification pipeline based on ensemble deep learning (DL). The DL-enabled pipeline utilized adaptive thresholding or semantic segmentation for RBC identification, a deep ensemble of four convolutional neural networks (CNNs) to classify RBC morphology, and Kalman filtering with Hungarian assignment for tracking changes in the morphology of individual RBCs over time. The ensembled CNNs were trained and evaluated on thousands of individual RBCs from two open-access datasets previously collected to quantify the morphological heterogeneity and washing-induced shape recovery of stored RBCs. Confusion matrices and reliability diagrams demonstrated under-confidence of the constituent models and an accuracy of about 98% for the deep ensemble. Such a high accuracy allowed the CNN ensemble to uncover new insights over our previously published studies. Re-analysis of the datasets yielded much more accurate distributions of the effective diameters of stored RBCs at each stage of morphological degradation (discocyte: 7.821 ± 0.429 µm, echinocyte 1: 7.800 ± 0.581 µm, echinocyte 2: 7.304 ± 0.567 µm, echinocyte 3: 6.433 ± 0.490 µm, sphero-echinocyte: 5.963 ± 0.348 µm, spherocyte: 5.904 ± 0.292 µm, stomatocyte: 7.080 ± 0.522 µm). The effective diameter distributions were significantly different across all morphologies, with considerable effect sizes for non-neighboring classes. A combination of morphology classification with cell tracking enabled the discovery of a relatively rare and previously overlooked shape recovery of some sphero-echinocytes to early-stage echinocytes after washing with 1% human serum albumin solution. Finally, the datasets and code have been made freely available online to enable replication, further improvement, and adaptation of our work for other applications.

Bionic design of a curvature-adjustable flexure hinge inspired by red blood cells

Recent years have witnessed an ever-increasing research interest in experience-driven and topology-optimization design of flexure hinges for use in compliant mechanisms. In this paper, we report the bionic design of a new notch flexure hinge with adjustable curvatures inspired by the biconcave disk morphology of red blood cells. The biconcave shape maintains red blood cells excellent deformability and surface properties that motivates the bio-inspired design by learning from nature. By imitating the biconcave shape of red blood cells using the quartic Bézier curve, the contour of a cluster of bio-inspired flexure hinges in the presence of positive and negative curvatures can be parametrically adjusted. The closed-form equations of compliance, precision and the maximum stress of the bio-inspired flexure hinge are derived based on Castigliano's second theorem and Timoshenko beam theory. Comparative studies verify the well precision and low stress of such a new flexure hinge. At last, an amplified piezoelectric actuator is designed with the bio-inspired flexure hinge as an application case. Also interestingly, adjustable curvatures of the presented bio-inspired flexure hinge make the simultaneous shape and parameter optimization effective.

Characteristics of endotoxemia in different ways of treatment of experimental burn in rats

The article evaluates the dynamics of toxemia and detoxification capabilities of various wound dressings in thermal burn injury in rats in the experiment. A wound dressing based on collagen and chitosan Collachit® and a membrane wound dressing containing a hyperosmolar solution in the cavity were compared. Studies of the dynamics of toxemia in burn disease after experimental thermal injury were carried out on Wistar rats (n=20). Analysis of the results of the study was carried out on the basis of clinical, morphological and biochemical parameters of the peripheral blood of rats with experimental burn injury. The study of the morphology of blood cells is carried out according to generally accepted methods. Biochemical manifestations of endotoxemia are established by the dynamics of ALT, AST, urea, creatinine. In the 1st group of rats (n=10), the Collachit® wound dressing was applied. In the 2nd group (n=10), a semi -permeable membrane filled with a hyperosmolar solution, constituting a necrolytic enzyme, was fixed on the surface of the burn. As a result, it was found that burn toxemia in rats proceeded in 2 phases and was accompanied by depression, food refusal, leukocytosis, increased LII, liver transferases, creatinine and urea. Hematological deviations were characterized by non-uniform dynamics, corresponding to the phase of burn toxemia with maximum increases on days 1-2 and 5-7, a fall on days 3-4, and days 8-10. Hematological manifestations of toxemia depended on the method of treatment and were less pronounced with the use of membrane wound dressings than with collachitis. External signs of toxemia do not in all cases correspond to the hematological and biochemical profile of toxemia, which indicates the possibility of a latent course of burn disease with some methods of treatment. The applied wound dressings had a pronounced antiseptic efficacy, characterized by the absence of purulent-inflammatory complications over the entire period of the experiment.

The hematopoietic potential ofmethanolic and aqueous extracts of Portulaca oleracea in a phenylhydrazine model of anemia.

Portulaca oleracea, commonly known as Purslane, is traditionally used as a sour, diuretic, and cooling herb with hemostatic properties. The present study evaluates the antianemic effect of methanolic and aqueous extracts of P. oleracea in a phenylhydrazine model of anemia. Phenylhydrazine (60 mg/kg/day, i.p., two consecutive days) was used to induce anemia in rats. The aqueous and methanolic extracts of P. oleracea were prepared, and three methods of treatment were defined with two doses (500 and 750 mg/kg, i.p.). The hematological parameters and blood cell morphology, total and direct bilirubin, and morphology, and pathology of bone marrow were evaluated. The results showed that the methanolic extract has better effects than aqueous extract in improving phenylhydrazine-induced anemia. Our results showed that administration of 500 and 750 mg/kg of P. oleracea methanolic extracts for 4 days could protect against the development of anemia caused by phenylhydrazine. In summary, the methanolic extracts of P. oleracea might be effective in phenylhydrazine-induced anemia.