Red Blood Cell Morphology Research Articles

Ferroportin inhibition attenuates plasma iron, oxidant stress, and renal injury following red blood cell transfusion in guinea pigs.

Red blood cell (RBC) transfusions result in the sequestration and metabolism of storage-damaged RBCs within the spleen and liver. These events are followed by increased plasma iron concentrations that can contribute to oxidant stress and cellular injury. We hypothesized that administration of a ferroportin inhibitor (FPN-INH) immediately after acute RBC exchange transfusion could attenuate posttransfusion circulatory compartment iron exposure, by retaining iron in spleen and hepatic macrophages. Donor guinea pig blood was leukoreduced, and RBCs were preserved at 4°C. Recipient guinea pigs (n = 5/group) were exchange transfused with donor RBCs after refrigerator preservation and dosed intravenously with a small-molecule FPN-INH. Groups included transfusion with vehicle (saline), 5 mg/kg or 25 mg/kg FPN-INH. A time course of RBC morphology, plasma non-transferrin-bound iron (NTBI) and plasma hemoglobin (Hb) were evaluated. End-study spleen, liver, and kidney organ iron levels, as well as renal tissue oxidation and injury, were measured acutely (24-hr after transfusion). RBC transfusion increased plasma NTBI, with maximal concentrations occurring 8 hours after transfusion. Posttransfusion iron accumulation resulted in tubule oxidation and acute kidney injury. FPN inhibition increased spleen and liver parenchymal/macrophage iron accumulation, but attenuated plasma NTBI, and subsequent renal tissue oxidation/injury. In situations of acute RBC transfusion, minimizing circulatory NTBI exposure by FPN inhibition may attenuate organ-specific adverse consequences of iron exposure.

Convolutional neural networks based focal loss for class imbalance problem: a case study of canine red blood cells morphology classification

Morphologies of red blood cells are normally interpreted by a pathologist. It is time-consuming and laborious. Furthermore, a misclassified red blood cell morphology will lead to false disease diagnosis and improper treatment. Thus, a decent pathologist must truly be an expert in classifying red blood cell morphology. In the past decade, many approaches have been proposed for classifying human red blood cell morphology. However, those approaches have not addressed the class imbalance problem in classification. A class imbalance problem---a problem where the numbers of samples in classes are very different---is one of the problems that can lead to a biased model towards the majority class. Due to the rarity of every type of abnormal blood cell morphology, the data from the collection process are usually imbalanced. In this study, we aimed to solve this problem specifically for classification of dog red blood cell morphology by using a Convolutional Neural Network (CNN)---a well-known deep learning technique---in conjunction with a focal loss function, adept at handling class imbalance problem. The proposed technique was conducted on a well-designed framework: two different CNNs were used to verify the effectiveness of the focal loss function and the optimal hyper-parameters were determined by 5-fold cross-validation. The experimental results show that both CNNs models augmented with the focal loss function achieved higher $F_{1}$-scores, compared to the models augmented with a conventional cross-entropy loss function that does not address class imbalance problem. In other words, the focal loss function truly enabled the CNNs models to be less biased towards the majority class than the cross-entropy did in the classification task of imbalanced dog red blood cell data.

The Safety and Exploration of the Pharmacokinetics of Intrapleural Liposomal Curcumin.

BackgroundMalignant pleural effusion (MPE) is the accumulation of fluid in the pleural cavity as a result of malignancies affecting the lung, pleura and mediastinal lymph nodes. Curcumin, a compound found in turmeric, has anti-cancer properties that could not only treat MPE accumulation but also reduce cancer burden. To our knowledge, direct administration of curcumin into the pleural cavity has never been reported, neither in animals nor in humans.PurposeTo explore the compartmental distribution, targeted pharmacokinetics and the safety profile of liposomal curcumin following intrapleural and intravenous administration.MethodsLiposomal curcumin (16 mg/kg) was administered into Fischer 344 rats by either intrapleural injection or intravenous infusion. The concentration of curcumin in plasma and tissues (lung, liver and diaphragm) were measured using ultra-performance liquid chromatography-mass spectrometry (UPLC-MS). Blood and tissues were examined for pathological changes.ResultsNo pleural or lung pathologies were observed following intrapleural liposomal curcumin administration. Total curcumin concentration peaked 1.5 hrs after the administration of intrapleural liposomal curcumin and red blood cell morphology appeared normal. A red blood cells abnormality (echinocytosis) was observed immediately and at 1.5 hrs after intravenous infusion of liposomal curcumin.ConclusionThese results indicate that liposomal curcumin is safe when administered directly into the pleural cavity and may represent a viable alternative to intravenous infusion in patients with pleural-based tumors.

Single red blood cell analysis reveals elevated hemoglobin in poikilocytes.

.Abnormally shaped red blood cells (RBCs), called poikilocytes, can cause anemia. At present, the biochemical abnormalities in poikilocytes are not well understood. Normal RBCs and poikilocytes were analyzed using whole-blood and single-cell methods. Poikilocytes were induced in rat blood by intragastrically administering titanium dioxide () nanoparticles. Complete blood count and inductively coupled plasma mass spectrometry analyses were performed on whole-blood to measure average RBC morphology, blood hemoglobin (HGB), iron content, and other blood parameters. Follow-up confocal Raman spectroscopy was performed on single RBCs to analyze cell-type-specific HGB content. Two types of poikilocytes, acanthocytes and echinocytes, were observed in blood samples, along with normal RBCs. Acanthocytes (diameter ) and echinocytes () were microscopically larger () than normal RBCs () found in control blood samples (no administration). Similarly, mean corpuscular volume was higher () in whole-blood () than in control whole-blood (). Poikilocytes also had higher HGB content. Mean corpuscular hemoglobin was higher () in whole-blood () than in control whole-blood (). Iron content was higher () in whole-blood () than in control whole-blood (), which supports elevated HGB as iron is found in HGB. HGB-associated Raman bands at 1637, 1585, and had higher () amplitudes in acanthocytes and echinocytes than in RBCs from control blood and normal RBCs from blood. Further, the band had a lower () amplitude in normal RBCs from versus control RBCs. This represents biochemical abnormalities in normal appearing RBCs. Overall, poikilocytes, especially acanthocytes, have elevated HGB.

Nuclear factor-kB and nitric oxide synthases in red blood cells: good or bad in obesity? A preliminary study.

Emerging evidence suggests that red blood cells (RBCs) are involved in many functions essential for life. Nuclear factor-kB (NF-kB), nitric oxide synthases (inducible nitric oxide synthase -iNOS-, endothelial nitric oxide synthase -eNOS-) and interleukin-1β (-IL-1β-) are all proteins that have been identified in RBCs. In nucleated cells, such as white blood cells (WBCs), these proteins have well investigated roles, linked to stress and inflammation. It is not the same in erythrocytes. For this reason, we considered obese patients for studying the morphology of RBCs. We studied a possible correlation between their morphological changes and several protein expressions. Moreover, we compared the results about the aforementioned proteins and antioxidant markers with those obtained in WBCs from healthy and obese patients before and after omega-3 polyunsaturated fatty acid supplementation. This latter scientific point is important in order to determine whether there are differences in the expression of nucleated and anucleated cells. The morphology of RBCs changed in obese patients, but it is significantly restored after six weeks of supplementation. The expression of antioxidant enzymes changed in RBCs and WBCs in obesity but all proteins restore their positivity after supplementation. We found that: the presence of NF-kB, antioxidant enzymes and eNOS in healthy RBCs could indicate a role of these proteins as regulators of cellular metabolism; obese WBCs showed a higher NF-kB, iNOS and IL-1β positivity, whereas eNOS presence did not significantly change in these cells. We tried to explain the different positivity of NF-kB, proposing a dual role for this protein, as prolifespan and as proinflammatory processes, depending on examined cells. In conclusion, we have considered the literature that focuses on the omega- 6/omega-3 ratio. The ratio changed from the past, especially in people whose diet is strongly westernized worsening the state of health of the patient and leading to an higher incidence of obesity. Our study hypothesizes that the supplementation could help to restore the correct ratio.

The influence and impact of smoking on red blood cell morphology and buccal microflora: A case-control study.

BackgroundTobacco smoking is a major health issue worldwide. In addition to several health problems, smoking can also cause buccal cavity ulcers and buccal cavity cancer in case of chronic smoking. Tobacco smoking may also lead to deranged morphology of red blood cells (RBCs), which results in reduced oxygen carrying capacity of the blood.Aim(a) To investigate and compare the changes in the RBC morphology of smokers and nonsmokers. (b) To investigate and compare the normal buccal flora of smokers and nonsmokers.MethodologyA total of 81 men were included in the study. Study population was divided into two groups: group 1; smokers (n = 50) and group 2; nonsmokers, which served as control (n = 31). After informed written consent from the study participants, a 5 mL of venous blood was drawn under sterile conditions for complete blood analysis and RBC morphology. Samples from buccal cavity were collected by cotton swab and cultured in sterile petri dishes to identify the bacterial growth. Data of RBC morphology and buccal microbiota were compared between smokers and nonsmokers.ResultsBuccal microflora results showed heavy growth in smokers compared with nonsmokers. Mean values of RBCs, Platelets, WBCs, HGB (hemoglobin), and MCV (mean corpuscular volume) did not differ between smokers and nonsmokers. Mean red cell distribution (RDW) width significantly was lower in smokers than nonsmokers. Macrocytic RBCs was more in smokers (60%) compared with nonsmokers (4%).ConclusionsOur results showed an increase in the percentage of macrocytic RBCs and a decrease in the red cell distribution width (RDW) in smokers compared with nonsmokers. Buccal Microflora was significantly higher in smoker group in contrast to nonsmoker group.

Postmortem Evaluation of Autolytic Changes in Morphology of Red Blood Cells and Haemogram Pattern for Estimation of Time since Death

The accurate estimation of time since death sometimes is very important for forensic experts in administration of justice. Various cells and tissues of the body showed significant changes with respect to post-mortem interval and one such sample is blood. The aim of this study is to assess the post-mortem autolytic changes in morphology of red blood cells and haemogram pattern for estimation of time since death. The present study was a cross sectional one and non random purposive sampling was done. The blood samples from 60 dead bodies which were brought for postmortem examination in the mortuary and preserved in <4°C temperature was taken after taking into consideration inclusion and exclusion criteria. The time since death was recorded and studied with respect to autolytic changes in RBC morphology and haemogram pattern. On meticulous examination of all the blood samples there were certain changes observed in the RBCs shape, intactness, central pallor and peripheral redness with respect to post-mortem interval. However, no statistical significance was correlated in the haemogram (RBC count, Hemoglobin, haematocrit, MCV, MCH and MCHC) with respect to time since death.

Changes in morphology of red blood cells with overdose of retinol palmitate

Changes in morphology of red blood cells with overdose of retinol palmitate

Действие низкоинтенсивного лазерного излучения различных диапазонов на морфологию эритроцитов

It is shown that under the influence of technological stress on the body of cattle, there is a violation of the ratio of normal forms of red blood cells – discocytes and their pathological forms – stomatocytes, echinocytes, the most common are echinocytes. To correct impaired body functions, the effect of continuous and fractional exposure to low-intensity laser radiation with wavelengths of 830 nm and 650 nm was studied. The obtained data indicate that the NILI with a wavelength of 650 nm and 830 nm does not have a negative effect on the morphology of bovine red blood cells. The stimulating and normalizing effect of low-intensity laser radiation on red blood cells was most pronounced in a continuous mode of exposure with a wavelength of 830 nm.

A New Electronic Instrumentation Approach for the Acquisition of Microscopic Blood Smear Images for the Automatic Diagnosis of Anemia

Anemia is a blood abnormality that affects the quantity and quality of red blood cells in the human body. This sometimes banal sign spares no continent and no social stratum. This anomaly is generally appreciated through biological analyzes of patients’ blood. These analyzes, which boil down to the knowledge of hemato-metric constants, cannot by themselves allow the characterization of certain forms of anemia in the sense that most anemia are related to the morphology and color of red blood cells. Our work in this paper is to perform blood smears on patients and perform a morphological and colorimetric analysis of red blood cells on these smears. This approach allowed us to highlight on each erythrocyte morphological and colorimetric descriptors to accurately identify the types of anemia by image processing methods. This identification is performed in an automated environment to allow pathologists to respond quickly to anemia-related emergencies and also improve the treatment to be conducted. This automation required the implementation of a new approach to electronic instrumentation and the acquisition of microscopic blood smear images for the automatic and rapid diagnosis of anemia.

Laboratory Approach to Hemolytic Anemia.

Hemolytic anemias are a group of disorders with varied clinical and molecular heterogeneity. They are characterized by decreased levels of circulating erythrocytes in blood. The pathognomic finding is a reduced red cell life span with severe anemia or, compensated hemolysis accompanied by reticulocytosis. The diagnostic workup or laboratory approach for hemolytic anemias is based on methodical step-wise testing which includes red blood cell morphology, hematological indices with increased reticulocyte count along with clinical features of hemolytic anemias. If conventional laboratory tests are unable to detect the underlying cause of hemolysis, genetic testing is recommended. Sanger sequencing along with conventional testing is the most efficient way to diagnose the underlying genetic causes, especially in thalassemias/hemoglobinopathies, if required. However, hemolytic anemias being highly heterogeneous disorders, next-generation sequencing-based screening is rapidly becoming an efficient way to decipher the etiologies where common causes have been excluded.

Effects of Polyphenol Compounds and Nitrogen Oxide Donors on Lipid Oxidation, Membrane-Skeletal Proteins, and Erythrocyte Structure under Hypoxia.

This study shows that membrane-associated cytoskeletal protein structures and the erythrocyte morphology undergo profound changes during hypoxia. Hypoxia also intensified oxidative processes in the lipid phase of the bilayer of red blood cell membranes. Sodium nitroprusside impaired the morphology of red blood cells and altered quantitative and qualitative composition of membrane-skeletal proteins. The findings suggest that hypoxia causes changes at all levels of red blood cell organization, which can cause the functional disorders of hemoglobin oxygen-transporting properties and, eventually, the complete degradation of red blood cells. The use of flavonoids has a protective effect against hypoxia.

Understanding the coffee-ring effect of red blood cells for engineering paper-based blood analysis devices

Red blood cells (RBCs), the most abundant cellular component in whole blood, are an important health indicator, and the morphology and behavior of RBCs on porous paper substrates plays a key role in the interpretation of the diagnostic results of paper-based blood analysis. The wetting of paper by a blood sample containing dispersed RBCs drives the allocation of RBCs through the fibre network. A blood stain left on paper, therefore, provides a wealth of information about the distribution and transport behaviors of RBCs. In this work, we studied the morphology and formation of and factors influencing the typical shape of blood stains, an RBC-based “coffee ring”, on paper substrates at both macroscopic and cellular levels. The results show that the ring-shaped RBC stain formed on paper is mainly the result of the combined effect of capillary wicking, filtration and evaporation flux, and is influenced by the fibre structure, RBC incubation time, relative humidity and paper additives. Most importantly, control of RBC stains was achieved by paper structure engineering and the dynamic transportation of RBCs on paper was quantified. These findings provide valuable insight into the control of the spatial distribution of RBCs on porous materials, which will be beneficial for the design of desirable paper-based diagnostics. A paper-based microfluidic device with advanced features was then fabricated to detect the hematocrit level, demonstrating the significance of this study for blood-based analysis and diagnostics on paper.

Evaluating the quality of red blood cell concentrates irradiated before or after cryopreservation.

Cryopreserved red blood cell concentrates (RCCs) are often required for patients with rare blood groups. Although transfusions from blood relatives are irradiated before transfusion, research has yet to make clear if this is necessary in cryopreserved RCCs. Given insufficient evidence to the contrary, irradiation of cryopreserved RCCs has been recommended, but the effect of irradiation timing is unknown. Therefore, this study was performed to assess the effect of RCC irradiation pre- and postcryopreservation on RCC quality. Nine whole blood units from healthy donors were processed into RCCs using the buffy coat method. ABO- and Rh-matched units were pooled and split into three groups: precryopreservation irradiation (pre-CIG), postcryopreservation irradiation (post-CIG), and nonirradiated controls. Hemoglobin, hematocrit, white blood cell (WBC) count, extracellular potassium, mean cell volume, red blood cell (RBC) morphology, and RBC deformability were measured. Extracellular potassium was greater in the irradiated conditions when compared to the nonirradiated controls and was greater in the post-CIG group when compared to the pre-CIG group (p < 0.05). WBC counts decreased after cryopreservation in all groups to values lower than the sensitivity of the assay. RBC deformability was greater in the post-CIG group when compared to the pre-CIG group and control group. No other significant differences were observed between groups. Irradiation of RCCs can be performed pre- or postcryopreservation with little effect on the RCC product, as both irradiated groups resulted in RCCs that were comparable to the nonirradiated cryopreserved RCCs.

Complementary Base Editing Approaches for the Treatment of Sickle Cell Disease and Beta Thalassemia

Sickle cell disease (SCD) and Beta thalassemia are disorders of beta globin production and function that lead to severe anemia and significant disease complications across a multitude of organ systems. Autologous transplantation of hematopoietic stem cells engineered through the upregulation of fetal hemoglobin (HbF) or correction of the beta globin gene have the potential to reduce disease burden in patients with beta hemoglobinopathies. Base editing is a recently developed technology that enables precise modification of the genome without the introduction of double strand DNA breaks. Gamma globin gene promoters were comprehensively screened with cytosine and adenine base editors (ABE) for the identification of alterations that would derepress HbF. Three regions were identified that significantly upregulated HbF, and the most effective nucleotide residue conversions are supported by natural variation seen in patients with hereditary persistence of fetal hemoglobin (HPFH). ABEs have been developed that significantly increase the level of HbF following nucleotide conversion at key regulatory motifs within the HBG1 and HBG2 promoters. CD34+ hematopoietic stem and progenitor cells (HSPC) were purified at clinical scale and edited using a process designed to preserve self-renewal capacity. Editing at two independent sites with different ABEs reached 94 percent and resulted in up to 63 percent gamma globin by UPLC. The levels of HbF observed should afford protection to the majority of SCD and Beta thalassemia patients based on clinical observations of HPFH and non-interventional therapy that links higher HbF dosage with milder disease (Ngo et al, 2011 Brit J Hem; Musallam et al, 2012 Blood). Directly correcting the Glu6Val mutation of SCD has been a recent goal of genetic therapies designed for the SCD population. Current base editing technology cannot yet convert mutations like those that result from the A-T transversion in sickle beta globin; however, ABE variants have been designed to recognize and edit the opposite stranded adenine residue of valine. This results in the conversion of valine to alanine and the production of a naturally occurring variant known as Hb G-Makassar. Beta globin with alanine at this position does not contribute to polymer formation, and patients with Hb G-Makassar present with normal hematological parameters and red blood cell morphology. SCD patient fibroblasts edited with these ABE variants achieve up to 70 percent conversion of the target adenine. CD34 cells from healthy donors were then edited with a lead ABE variant, targeting a synonymous mutation in an adjacent proline that resides within the editing window and serves as a proxy for editing the SCD mutation. The average editing frequency was 40 percent. Donor myeloid chimerism documented at these levels in the allogeneic transplant setting exceeds the 20 percent that is required for reversing the sickle phenotype (Fitzhugh et al, 2017 Blood). These next generation editing approaches provide a promising new modality for treating patients with Beta thalassemia and SCD. Disclosures No relevant conflicts of interest to declare.

A Novel Composition of Endogenous Metabolic Modulators, AXA4010, Impacts Adhesion, Inflammation and RBC Membrane Deformability in Preclinical Models of Sickle Cell Disease

Background: In sickle cell disease (SCD), red blood cell (RBC) sickling propagates hemolysis, inflammation, vascular and endothelial injury with associated disruption in metabolic pathways including nitric oxide depletion, oxidative stress and an increased anabolic and energetic demand due to high RBC turnover. These metabolic functions highlight the role of amino acid biology in blood health and diseases such as SCD, which has motivated numerous individual amino acid (AA) based clinical studies. Here, we measured AA profiles of SCD plasma samples and examined the impact of combinations of AAs and metabolites on preclinical models of vascular adhesion, inflammation, and RBC function. This combined work serves as the basis for investigational product AXA4010, a composition of 10 distinct AAs and metabolites designed to target and support RBC, inflammatory, endothelial and vascular health, with the potential to impact the multifaceted pathology of SCD. Methods: Plasma AA profiles of SCD adults (n=38) and healthy adults (n=40) were measured by LC-MS analysis. Plasma AA profiles from SCD adults informed the design of a defined "SCD medium" used for culturing primary human lung microvascular endothelial cells (HLMVEC) as a preclinical SCD model of adhesion and inflammation. HLMVEC cells cultured in "SCD medium" were co-treated with TNFα and either AXA4010, components of AXA4010, or individual constituent AAs/metabolites, and adhesion, inflammation, and cell migration pathways were characterized using functional assays. Healthy RBCs were treated ex vivo with AXA4010 or individual constituents and stressed using tert-Butyl hydroperoxide (t-BuOOH) treatment, RBC deformability was characterized by ektacytometry (LORRCA, RR Mechatronics). Results: When compared to age-match controls, plasma AA profiles of SCD adults had significantly reduced arginine (-36%, p = 1.8e-4), leucine (-38%, p = 3.6e-6), valine (-36%, p = 2.8e-8), lysine (-38%, p = 6.2e-9), and histidine (-23%, p = 2.8e-4). In "SCD medium" cultured HLMVECs treated with TNFα, we observed AXA4010 reduced markers of adhesion (↓VCAM-1, ↓ICAM-1), inflammation (↓IL-6), and cell migration (↓MCP-1) in a dose dependent manner. In RBCs, we observed AXA4010 protected against t-BuOOH induced loss of RBC deformability. Deconvolution of AXA4010 and subset components revealed unexpected combinatorial interactions and potentiating effects of the constituents within the composition. Conclusion: We combined human plasma AA profiling and combinatorial cell-based experimentation to design AXA4010. In primary human cell systems with AXA4010 we observed improved adhesion, inflammation, and RBC morphology markers, which are associated with blood health and SCD pathogenesis, in a composition specific manner. These results warrant clinical investigation of AXA4010, which we have now initiated in a cohort of SCD subjects to investigate safety, tolerability and impact on blood physiology. Disclosures Hamill: Axcella Health: Employment. Carroll:Axcella Health: Employment. Wani:Axcella Health: Employment. Russell:Axcella Health: Employment. Steuert:Axcella Health: Employment. Nitzel:Axcella Health: Employment. Downey:Axcella Health: Employment. Cokol:Axcella Health: Employment. Afeyan:Axcella Health: Employment. Marukian:Axcella Health: Employment. Tramontin:Axcella Health: Employment.

Distribusi Southeast Asia Ovalocytosis (SAO) pada Berbagai Populasi Masyarakat di Kepulauan Sunda Kecil

The presence of some genetic markers related to malaria as hemoglobinopathies, enzymophaties and ovalocytosis in populations of Lesser Sunda Islands are presumed to be quite high, since this archipelago is mostly malaria endemic. To elucidate the problem, a series of observations had been done among 579 blood samples which were collected from five different populations (Balinese, Sasak, Sumbawanese, Sumbanese, and Alorese) representing inhibitant of Lesser Sunda Islands. In this paper we present the distribution of Southeast Asia Ovalocytosis (SAO) which was detected by microscopic examination of the red blood cell morphology. Among these, 38 subjects were suspected as SAO whereas the incidence ranges from 2.2% in Balinese to 15.7% in Alorese. It was predicted that the high incidence of SAO in Alorese might be associated with malaria selection to compensate the absence of hemoglobinophaties in this population.

Natural cryoprotectants combinations of l-proline and trehalose for red blood cells cryopreservation

Cryopreservation of red blood cells (RBCs) holds great potential benefits for supplying transfusion timely in emergencies. Currently, glycerol is the main cryoprotectant permitted in clinical therapy for RBCs cryopreservation, but its broad application is limited by the toxicity and complex deglycerolization process. Successful cryopreservation of RBCs using more effective materials should be studied to reduce freezing damage, increase biocompatibility, and save processing time. Herein, a simple protocol using natural cryoprotectants combinations of l-proline and trehalose attains a low degree of hemolysis (11.2 ± 2.73%) after thawing compared to glycerol. Furthermore, the morphology of RBCs and the activities of Na+/K+-ATPase and Ca2+/Mg2+-ATPase maintain well. Further mechanism study shows that l-proline plays an important role in decreasing the freezing points and inhibiting the growth of ice crystal by permeating into cells during the freezing process. While trehalose works as an inhibitor of ice growth in the freezing process and ice recrystallization in the thawing process. This simple l-proline & trehalose combinations protocol is a promising method to replace current time-consuming and labor-intensive cryopreservation methods of RBCs.

The stability of spherocyte membranes: Theoretical study

Human red blood cell (RBC) membranes are typically biconcave-shaped under physiological conditions, and membranes of other shapes, such as spherical, are also observed in pathological RBCs. It has been suggested that there is a relationship between the RBC membrane's material properties, morphologies and physiological functions. The present work studies how various factors affect the morphologies of the RBC membrane based on a free energy functional in continuum elasticity descriptions. In particular, the instability conditions of a diseased spherocyte's spherical shape is obtained explicitly, which determines the region in the phase diagram constructed by two dimensionless state variables defined by elastic moduli, osmotic pressure, etc., in which the spherocyte's membrane can exist in a stable form. In this phase diagram, each point represents the statistical results for a large number of samples observed in recent experiments. Within this stable region of spherocyte's membrane, the spherical RBC membrane is in the global minimal state whereas in the adjacent region on the other side of the boundary, the echinocyte's membrane corresponds to the global minimal state. Our results could be used as a theoretical guide for clinical applications in related diseases, such as malaria, and are in quantitative agreement with recent dynamic optical measurements on the morphological transition of the RBC membrane (see Park Y. et al. Proc. Natl. Acad. Sci. U.S.A., 107 (2010) 6731).

To Study the Effect of Oxygen Carrying Capacity on Exosomes of Red Blood Cells in Different Storage Times

Background: Blood is a fluid tissue composed of blood cells and plasma. It mainly transports oxygen, nutrients and metabolites for various tissues and organs of the body. Among them, red blood cells are the important means of oxygen transport. After the blood is stored for a period of time, the structure and properties of the red blood cells will change, which results in a decrease in the oxygen carrying capacity, and the change in the oxygen carrying capacity will also have a certain impact on their exosomes. Methods: Therefore, our research is to detect some carry oxygen function related indicators of red blood cells in different storage times, including effective oxygen uptake (Q), P50, 2, 3-DPG, Na+-K+-ATP. Electron microscopy was used to observe the morphology of red blood cells and the characteristics of secreting exosomes. Western Blot was used to detect the expression of phenotypes CD63 and CD81 of exosomes, and the expression of mitochondrial riboprotein MRPS35 of exosomes was also detected to explore the mechanism of decreased function of red blood cells with the extension of preservation time. Results: Changes in the rheological properties and oxygen-carrying functions of erythrocytes during the preservation process are all appearances, underlying which lies the damage mechanism at the molecular level of erythrocytes. Conclusion:Erythrocytes secrete exosomes, which resulted in abnormal expression of related proteins in mitochondria to increase ROS, mitochondrial apoptosis, and finally changes or damage to erythrocytes. Funding Statement: This work is supported by Key Disciplines Group Construction Project of Pudong Health Bureau of Shanghai (No.PWZxq2017-10), and National Natural Science Foundation of China (No. 81671919, 81870147). Declaration of Interests: All of the authors have no conflict of interest in this research. Ethics Approval Statement: Ethical approval was given by Gongli hospital, The Second Military Medical University.