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1.
Braz. j. biol ; 84: e249617, 2024. graf
Artigo em Inglês | LILACS, VETINDEX | ID: biblio-1345540

RESUMO

Abstract Hibernation is a natural condition of animals that lives in the temperate zone, although some tropical lizards also experience hibernation annually, such as the lizard native from South America, Salvator merianae, or "tegu" lizard. Even though physiological and metabolic characteristic associated with hibernation have been extensively studied, possible alterations in the red blood cells (RBC) integrity during this period remains unclear. Dehydration and fasting are natural consequences of hibernating for several months and it could be related to some cellular modifications. In this study, we investigated if the osmotic tolerance of RBCs of tegu lizard under hibernation is different from the cells obtained from animals while normal activity. Additionally, we indirectly investigated if the RBCs membrane of hibernating tegus could be associated with oxidation by quantifying oxidized biomolecules and the activity of antioxidant enzymes. Our findings suggest that RBCs are more fragile during the hibernation period, although we did not find evidence of an oxidative stress scenario associated with the accentuated fragility. Even though we did not exclude the possibility of oxidative damage during hibernation, we suggested that an increased RBCs volume as a consequence of hypoosmotic blood during hibernation could also affect RBCs integrity as noted.


Resumo A hibernação é uma condição natural dos animais que vivem na zona temperada, embora alguns lagartos tropicais também experenciem hibernação anualmente, como é o caso do lagarto nativo da América do Sul, Salvator merianae ou "teiú". Embora as características fisiológicas e metabólicas associadas à hibernação tenham sido amplamente estudadas, possíveis alterações na integridade das hemácias durante esse período ainda permanecem obscuras. A desidratação e o jejum são consequências naturais da hibernação por vários meses e podem estar relacionadas a algumas modificações celulares. Neste estudo, investigamos se a tolerância osmótica de hemácias do lagarto teiú sob hibernação são diferentes das células obtidas de animais em atividade normal. Além disso, investigamos indiretamente por meio da quantificação de biomoléculas oxidadas e da atividade de enzimas antioxidantes se a membrana das hemácias dos teiús em hibernação poderia estar associada à oxidação. Nossos resultados sugerem que as hemácias possuem maior fragilidade durante o período de hibernação, embora não tenhamos encontrado evidências de um cenário de estresse oxidativo associado à essa fragilidade acentuada. Embora não tenhamos excluído a possibilidade de dano oxidativo durante a hibernação, sugerimos que um aumento no volume das hemácias como consequência de sangue hipoosmótico durante a hibernação também poderia afetar a integridade de hemácias, tal como foi observado.


Assuntos
Animais , Hibernação , Lagartos , Oxirredução , Estresse Oxidativo , Eritrócitos
2.
Braz. j. biol ; 84: e251289, 2024. tab, graf
Artigo em Inglês | LILACS, VETINDEX | ID: biblio-1355889

RESUMO

Abstract The present research was made to determine the micronuclei and cytotoxic capacity of the antidepressant venlafaxine in an in vivo acute and subchronic assays in mouse. In the first study, we administered once 5, 50, and 250 mg/kg of the drug, and included a negative and a daunorubicin treated group. Observations were daily made during four days. The subchronic assay lasted 5 weeks with daily administration of venlafaxine (1, 5, and 10 mg/kg) plus a negative and an imipramine administered groups. Observations were made each week. In the first assay results showed no micronucleated polychromatic erythrocytes (MNPE) increase, except with the high dose at 72 h. The strongest cytotoxic effect was found with 250 mg/kg at 72 h (a 51% cytotoxic effect in comparison with the mean control level). In the subchronic assay no MNPE increase was found; however, with the highest dose a significant increase of micronucleated normochromatic erythrocytes was observed in the last three weeks (a mean of 51% respect to the mean control value). A cytotoxic effect with the two high doses in the last two weeks was observed (a polychromatic erythrocyte mean decrease of 52% respect to the mean control value). Results suggest caution with venlafaxine.


Resumo A presente pesquisa foi feita para determinar a capacidade micronuclei e citotóxica do antidepressivo venlafaxina em ensaios agudos e subcrônicos in vivo em camundongos. No primeiro estudo, administramos uma vez 5, 50 e 250 mg/kg do medicamento e incluímos um grupo negativo e um grupo tratado com daunorubicina. As observações foram feitas diariamente durante quatro dias. O ensaio subcrônico durou cinco semanas com administração diária de venlafaxina (1, 5, e 10 mg/kg) mais um grupo negativo e um grupo administrado de imipramina. As observações foram feitas a cada semana. No primeiro ensaio, os resultados não mostraram aumento de eritrócitos policromáticos micronucleados (MNPE), exceto com a dose elevada a 72 h. O efeito citotóxico mais forte foi encontrado com 250 mg/kg a 72 h (um efeito citotóxico de 51% em comparação com o nível médio de controle). No ensaio subcrônico não foi encontrado aumento de MNPE; entretanto, com a dose mais alta, um aumento significativo de eritrócitos normocromáticos micronucleados foi observado nas últimas três semanas (média de 51% em relação ao valor médio de controle). Foi observado um efeito citotóxico com as duas altas doses nas últimas duas semanas (uma diminuição média de 52% em relação ao valor médio de controle dos eritrócitos policromáticos). Os resultados sugerem cautela com a venlafaxina.


Assuntos
Animais , Coelhos , Dano ao DNA , Antineoplásicos , Testes para Micronúcleos , Relação Dose-Resposta a Droga , Eritrócitos , Cloridrato de Venlafaxina/toxicidade
3.
Sensors (Basel) ; 23(2)2023 Jan 10.
Artigo em Inglês | MEDLINE | ID: mdl-36679593

RESUMO

The purpose of the recent work is to give a better explanation of how Dean vortices affect lateral focusing, and to understand how cell morphology can alter the focusing position compared to spherical particles. The position and extent of the focused region were investigated using polystyrene fluorescent beads with different bead diameters (Ø = 0.5, 1.1, 1.97, 2.9, 4.8, 5.4, 6.08, 10.2, 15.8, 16.5 µm) at different flow rates (0.5, 1, 2 µL/s). Size-dependent focusing generated a precise map of the equilibrium positions of the spherical beads at the end of the periodically altering channels, which gave a good benchmark for focusing multi-dimensional particles and cells. The biological samples used for experiments were rod-shaped Escherichia coli (E. coli), discoid biconcave-shaped red blood cells (RBC), round or ovoid-shaped yeast, Saccharomyces cerevisiae, and soft-irregular-shaped HeLa cancer-cell-line cells to understand how the shape of the cells affects the focusing position at the end of the channel.


Assuntos
Técnicas Analíticas Microfluídicas , Microfluídica , Humanos , Microfluídica/métodos , Escherichia coli , Eritrócitos , Saccharomyces cerevisiae , Células HeLa , Técnicas Analíticas Microfluídicas/métodos
4.
Med Klin Intensivmed Notfmed ; 118(1): 30-34, 2023 Feb.
Artigo em Alemão | MEDLINE | ID: mdl-36598517

RESUMO

Hemolytic anemia (HA) is caused by premature destruction or degradation of red blood cells (RBC). Low hemoglobin, suppressed haptoglobin, reticulocytosis as well as an elevation of lactate dehydrogenase and bilirubin are common laboratory findings in HA. Intracorpuscular HA due to defects of the RBC themselves are distinguished from extracorpuscular HA due to external factors. Severity of symptoms such as fatigue and dyspnea depend on the degree of anemia. For optimal treatment of HA, a detailed evaluation of the patient history (including hereditary RBC defects, B symptoms and travel history) is necessary. Additional diagnostics (hematological diagnostics, infectious disease diagnostics, immunological diagnostics, computed tomography [CT] scan) should be performed according to the patient's individual requirements. Treatment of HA depends on the etiology. If HA is immune-mediated, immunosuppressive therapy is indicated, whereas HA due to infections usually improves after adequate anti-infective therapy. Anti-infective therapy should also be considered in patients with sickle cell disease who present with severe HA. In general, HA can be treated effectively in most cases.


Assuntos
Anemia Hemolítica , Medicina , Humanos , Anemia Hemolítica/diagnóstico , Anemia Hemolítica/terapia , Eritrócitos , Diagnóstico Diferencial
5.
J Nanobiotechnology ; 21(1): 15, 2023 Jan 16.
Artigo em Inglês | MEDLINE | ID: mdl-36647056

RESUMO

BACKGROUND: Malaria remains a serious threat to global public health. With poor efficacies of vaccines and the emergence of drug resistance, novel strategies to control malaria are urgently needed. RESULTS: We developed erythrocyte membrane-camouflaged nanoparticles loaded with artemether based on the growth characteristics of Plasmodium. The nanoparticles could capture the merozoites to inhibit them from repeatedly infecting normal erythrocytes, owing to the interactions between merozoites and heparin-like molecules on the erythrocyte membrane. Modification with a phosphatidylserine-targeting peptide (CLIPPKF) improved the drug accumulation in infected red blood cells (iRBCs) from the externalized phosphatidylserine induced by Plasmodium infection. In Plasmodium berghei ANKA strain (pbANKA)-infected C57BL/6 mice, the nanoparticles significantly attenuated Plasmodium-induced inflammation, apoptosis, and anemia. We observed reduced weight variation and prolonged survival time in pbANKA-challenged mice, and the nanoparticles showed good biocompatibility and negligible cytotoxicity. CONCLUSION: Erythrocyte membrane-camouflaged nanoparticles loaded with artemether were shown to provide safe and effective protection against Plasmodium infection.


Assuntos
Malária , Merozoítos , Animais , Camundongos , Membrana Eritrocítica , Fosfatidilserinas , Biomimética , Camundongos Endogâmicos C57BL , Malária/tratamento farmacológico , Malária/prevenção & controle , Eritrócitos , Artemeter/farmacologia , Plasmodium berghei , Plasmodium falciparum
6.
PLoS One ; 18(1): e0280282, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-36626386

RESUMO

Complement Receptor Type 1 (CR1) is a malaria-associated gene that encodes a transmembrane receptor of erythrocytes and is crucial for malaria parasite invasion. The expression of CR1 contributes to the rosetting of erythrocytes in the brain bloodstream, causing cerebral malaria, the most severe form of the disease. Here, we study the history of adaptation against malaria by analyzing selection signals in the CR1 gene. We used whole-genome sequencing datasets of 907 healthy individuals from malaria-endemic and non-endemic populations. We detected robust positive selection in populations from the hyperendemic regions of East India and Papua New Guinea. Importantly, we identified a new adaptive variant, rs12034598, which is associated with a slower rate of erythrocyte sedimentation and is linked with a variant associated with low levels of CR1 expression. The combination of the variants likely drives natural selection. In addition, we identified a variant rs3886100 under positive selection in West Africans, which is also related to a low level of CR1 expression in the brain. Our study shows the fine-resolution history of positive selection in the CR1 gene and suggests a population-specific history of CR1 adaptation to malaria. Notably, our novel approach using population genomic analyses allows the identification of protective variants that reduce the risk of malaria infection without the need for patient samples or malaria individual medical records. Our findings contribute to understanding of human adaptation against cerebral malaria.


Assuntos
Malária Cerebral , Receptores de Complemento 3b , Humanos , Eritrócitos , Malária Cerebral/genética , Malária Cerebral/metabolismo , Papua Nova Guiné , Receptores de Complemento 3b/genética , Seleção Genética , Genética Populacional , Índia
7.
Crit Care ; 27(1): 25, 2023 01 17.
Artigo em Inglês | MEDLINE | ID: mdl-36650557

RESUMO

BACKGROUND: In-hospital acute resuscitation in trauma has evolved toward early and balanced transfusion resuscitation with red blood cells (RBC) and plasma being transfused in equal ratios. Being able to deliver this ratio in prehospital environments is a challenge. A combined component, like leukocyte-depleted red cell and plasma (RCP), could facilitate early prehospital resuscitation with RBC and plasma, while at the same time improving logistics for the team. However, there is limited evidence on the clinical benefits of RCP. OBJECTIVE: To compare prehospital transfusion of combined RCP versus RBC alone or RBC and plasma separately (RBC + P) on mortality in trauma bleeding patients. METHODS: Data were collected prospectively on patients who received prehospital transfusion (RBC + thawed plasma/Lyoplas or RCP) for traumatic hemorrhage from six prehospital services in England (2018-2020). Retrospective data on patients who transfused RBC from 2015 to 2018 were included for comparison. The association between transfusion arms and 24-h and 30-day mortality, adjusting for age, injury mechanism, age, prehospital heart rate and blood pressure, was evaluated using generalized estimating equations. RESULTS: Out of 970 recruited patients, 909 fulfilled the study criteria (RBC + P = 391, RCP = 295, RBC = 223). RBC + P patients were older (mean age 42 vs 35 years for RCP and RBC), and 80% had a blunt injury (RCP = 52%, RBC = 56%). RCP and RBC + P were associated with lower odds of death at 24-h, compared to RBC alone (adjusted odds ratio [aOR] 0.69 [95%CI: 0.52; 0.92] and 0.60 [95%CI: 0.32; 1.13], respectively). The lower odds of death for RBC + P and RCP vs RBC were driven by penetrating injury (aOR 0.22 [95%CI: 0.10; 0.53] and 0.39 [95%CI: 0.20; 0.76], respectively). There was no association between RCP or RBC + P with 30-day survival vs RBC. CONCLUSION: Prehospital plasma transfusion for penetrating injury was associated with lower odds of death at 24-h compared to RBC alone. Large trials are needed to confirm these findings.


Assuntos
Serviços Médicos de Emergência , Ferimentos e Lesões , Humanos , Adulto , Transfusão de Eritrócitos , Transfusão de Componentes Sanguíneos , Estudos Retrospectivos , Plasma , Hemorragia/terapia , Ressuscitação , Eritrócitos , Inglaterra , Ferimentos e Lesões/complicações , Ferimentos e Lesões/terapia
8.
Biomolecules ; 13(1)2023 Jan 09.
Artigo em Inglês | MEDLINE | ID: mdl-36671515

RESUMO

The membrane of the human red cell consists of a lipid bilayer and a so-called membrane skeleton attached on the cytoplasmic side of the bilayer. Upon the deformation of red cells, energy is dissipated in their cytoplasm and their membrane. As to the membrane, three contributions can be distinguished: (i) A two-dimensional shear deformation with the membrane viscosity as the frictional parameter; (ii) A motion of the membrane skeleton relative to the bilayer; (iii) A relative motion of the two monolayers of the bilayer. The frictional parameter in contributions (ii) and (iii) is a frictional coefficient specific for the respective contribution. This perspective describes the history up to recent advances in the knowledge of these contributions. It reviews the mechanisms of energy dissipation on a molecular scale and suggests new ones, particularly for the first contribution. It proposes a parametric fitting expected to shed light on the discrepant values found for the membrane viscosity by different experimental approaches. It proposes strategies that could allow the determination of the frictional coefficients pertaining to the second and the third contribution. It highlights the consequences characteristic times have on the state of the red cell membrane in circulation as well as on the adaptation of computer models to the red cell history in an in vitro experiment.


Assuntos
Membrana Eritrocítica , Eritrócitos , Humanos , Membrana Eritrocítica/metabolismo , Bicamadas Lipídicas/metabolismo , Simulação por Computador , Citoplasma , Membrana Celular
9.
Biosensors (Basel) ; 13(1)2023 Jan 09.
Artigo em Inglês | MEDLINE | ID: mdl-36671952

RESUMO

The utilizations of microfluidic chips for single RBC (red blood cell) studies have attracted great interests in recent years to filter, trap, analyze, and release single erythrocytes for various applications. Researchers in this field have highlighted the vast potential in developing micro devices for industrial and academia usages, including lab-on-a-chip and organ-on-a-chip systems. This article critically reviews the current state-of-the-art and recent advances of microfluidics for single RBC analyses, including integrated sensors and microfluidic platforms for microscopic/tomographic/spectroscopic single RBC analyses, trapping arrays (including bifurcating channels), dielectrophoretic and agglutination/aggregation studies, as well as clinical implications covering cancer, sepsis, prenatal, and Sickle Cell diseases. Microfluidics based RBC microarrays, sorting/counting and trapping techniques (including acoustic, dielectrophoretic, hydrodynamic, magnetic, and optical techniques) are also reviewed. Lastly, organs on chips, multi-organ chips, and drug discovery involving single RBC are described. The limitations and drawbacks of each technology are addressed and future prospects are discussed.


Assuntos
Anemia Falciforme , Técnicas Analíticas Microfluídicas , Humanos , Microfluídica/métodos , Eritrócitos , Testes Hematológicos , Dispositivos Lab-On-A-Chip
10.
Indian J Pathol Microbiol ; 66(1): 209, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-36656246
11.
Hematology ; 28(1): 2161215, 2023 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-36607150

RESUMO

The use of blood products to resuscitate injured and massively bleeding patients in the prehospital and early in-hospital phase of the resuscitation is increasing. Using group O red blood cells (RBC) and low titer group O whole blood (LTOWB) avoids an immediate hemolytic reaction from recipient's naturally occurring anti-A and - B, but choosing the RhD type for these products is more nuanced and requires the balancing of product availability and survival benefit against the risk of D-alloimmunization, especially in females of childbearing potential (FCP) due to the possible future occurrence of hemolytic disease of the fetus and newborn (HDFN). Recent models have estimated the risk of fetal/neonatal death from HDFN resulting from D-alloimmunization of an FCP during her trauma resuscitation at between 0-6.5% depending on her age at the time of the transfusion and other societal factors including trauma mortality, her age when she becomes pregnant, frequency of different RHD genotypes in the population, and the probability that the woman will have children with different fathers; this is counterbalanced by an approximately 24% risk of death from hemorrhagic shock. This review will discuss the different models of HDFN outcomes following RhD-positive transfusion as well as the results of recent surveys where the public was asked about their preferences for urgent transfusion in light of the risks of fetal/neonatal adverse events.


Assuntos
Anemia Hemolítica Autoimune , Eritroblastose Fetal , Gravidez , Feminino , Recém-Nascido , Criança , Humanos , Eritroblastose Fetal/etiologia , Eritroblastose Fetal/terapia , Eritrócitos , Transfusão de Sangue , Feto
12.
Mymensingh Med J ; 32(1): 265-267, 2023 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-36594332

RESUMO

Paroxysmal nocturnal haemoglobinuria (PNH) is a rare disorder of hematopoietic stem cells. The occurrence of PNH in a patient with systemic lupus erythematosus (SLE) is even rarer. One such presentation was seen in a 19 years old woman who presented with fever, multiple joint pain, photosensitivity, oral ulcer, hair loss and was diagnosed as a case of SLE and was admitted in Bangabandhu Sheikh Mujib Medical University (BSMMU), Dhaka, Bangladesh on 7th February 2019. Subsequently she developed progressive anaemia and passing of dark colored urine. Flow cytometry analysis showed PNH clone within red cells. We report this case so that clinicians are aware about this association between PNH and SLE. Informed written consent was obtained from the patient for the publication of this case report, the copy of which is available with the authors.


Assuntos
Hemoglobinúria Paroxística , Lúpus Eritematoso Sistêmico , Feminino , Humanos , Adulto Jovem , Adulto , Hemoglobinúria Paroxística/complicações , Hemoglobinúria Paroxística/diagnóstico , Bangladesh , Eritrócitos , Lúpus Eritematoso Sistêmico/complicações , Lúpus Eritematoso Sistêmico/diagnóstico , Citometria de Fluxo
13.
BMC Nephrol ; 24(1): 1, 2023 Jan 03.
Artigo em Inglês | MEDLINE | ID: mdl-36597041

RESUMO

BACKGROUND: The improvement of anaemia over time by erythropoiesis stimulating agent (ESA) is associated with better survival in haemodialysis patients. We previously reported that erythrocyte creatine content, a marker of erythropoietic capacity, was a reliable marker to estimate the effectiveness of ESA. The aim of this study was to examine the accuracy and clinical usefulness of erythrocyte creatine content to predict the improvement of anaemia in haemodialysis patients. METHODS: ESA dose was fixed 3 months prior to the enrollment and was maintained throughout the study period. Erythrocyte creatine content and haematologic indices were measured at baseline in 92 patients receiving maintenance haemodialysis. Haemoglobin was also measured 3 months after. Improvement of anaemia was defined as ≥ 0.8 g/dL change in haemoglobin from baseline to 3 months. RESULTS: Erythrocyte creatine content was significantly higher in 32 patients with improvement of anaemia compared to 60 patients with no improvement of anaemia (2.47 ± 0.74 vs. 1.57 ± 0.49 µmol/gHb, P = 0.0001). When 9 variables (erythrocyte creatine content, ESA dose, reticulocyte, haptoglobin, haemoglobin at baseline, serum calcium, intact parathyroid hormone, transferrin saturation and serum ferritin) were used in the multivariate logistic regression analysis, erythrocyte creatine emerged as the most important variable associated with the improvement of anaemia (P = 0.0001). The optimal cut-off point of erythrocyte creatine content to detect the improvement of anaemia was 1.78 µmol/gHb (Area under the curve: 0.86). Sensitivity and specificity of erythrocyte creatine content to detect the improvement of anaemia were 90.6% and 83.3%. CONCLUSION: Erythrocyte creatine content is a reliable marker to predict the improvement of anaemia 3 months ahead in patients receiving maintenance haemodialysis.


Assuntos
Anemia , Eritropoetina , Hematínicos , Oxibato de Sódio , Humanos , Creatina , Anemia/diagnóstico , Anemia/etiologia , Anemia/terapia , Eritrócitos/química , Diálise Renal/efeitos adversos , Hematínicos/uso terapêutico , Hemoglobinas/análise
14.
J Evid Based Integr Med ; 28: 2515690X221150526, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-36617811

RESUMO

Malaria-associated cardiac injury has been reported to be the primary cause of death due to severe malaria. The discovery of substances showing a protective effect on cardiac injury during malaria infection is urgently needed. Hence, the purpose of this study was to evaluate the efficacy of Gymnema inodorum leaf extract (GIE) on cardiac function in mice infected with Plasmodium berghei. ICR mice were treated with 1 × 107 infected red blood cells of P. berghei ANKA (PbANKA), administered orally with GIE in 100, 250 and 500 mg/kg body weight of mice. Creatine phosphokinase (CPK) and echocardiography were carried out. It was found that CPK and heart-weight to body-weight (HW/BW) ratios were significantly higher in untreated mice than the healthy control. Moreover, impaired cardiac function in the untreated group was observed as indicated by changes in echocardiography. Interestingly, GIE exerted a protective effect on cardiac injury induced by PbANKA infection. Our results demonstrated that the parasitemia percentage, CPK, HW/BW ratio, and echocardiography in GIE treated mice were improved. However, there was no significant difference between GIE dosages. Therefore, GIE possessed a cardio-protective effect during malaria infection in mice.


Assuntos
Malária , Plasmodium berghei , Animais , Camundongos , Extratos Vegetais/farmacologia , Camundongos Endogâmicos ICR , Malária/tratamento farmacológico , Eritrócitos
16.
J Trauma Nurs ; 30(1): 14-19, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-36633340

RESUMO

BACKGROUND: Hyperkalemia is associated with the rapid transfusion of packed red blood cells in trauma patients. Rapid infusers can infuse blood up to 500 ml/min. OBJECTIVE: This study aimed to determine whether infusing packed red blood cells through a rapid infuser impacts the potassium levels of the infused blood. METHODS: Two baseline samples were obtained to measure potassium and hemolysis scores in 12 units of expired blood prior to infusion. The blood was then infused via the Belmont Rapid Infuser into collection bags at varying infusion rates (50, 100, 250, and 500 ml/min) utilizing different gauge catheter sizes (18-gauge, 16-gauge, and Cordis catheter). Two postinfusion blood samples were collected and tested for potassium and hemolysis scores and compared with preinfusion values. This process was then repeated with fresh blood. RESULTS: The potassium levels of the samples taken from each unit prior to infusion (average difference 0.245) and after infusion (average difference 0.08) correlated well. There was no difference in potassium levels pre- and postinfusion at any infusion rate after accounting for catheter size and age of blood. The median potassium level of the fresh blood was 5.025 prior to infusion and 4.875 after infusion. The median potassium level of the expired blood was 16.05 prior to infusion and 16.4 postinfusion. There was no significant difference in the hemolysis scores between the preinfusion and postinfusion samples. CONCLUSIONS: Hyperkalemia in trauma patients undergoing massive transfusions is not a result of mechanical hemolysis from the high rates of blood infusion.


Assuntos
Hiperpotassemia , Humanos , Hemólise , Transfusão de Sangue , Potássio , Eritrócitos
17.
Malar J ; 22(1): 5, 2023 Jan 05.
Artigo em Inglês | MEDLINE | ID: mdl-36604655

RESUMO

BACKGROUND: Polymorphisms in ATP2B4 coding for PMCA4b, the primary regulator of erythrocyte calcium concentration, have been shown by GWAS and cross-sectional studies to protect against severe malaria but the mechanism remains unknown. METHODS: Using a recall-by-genotype design, we investigated the impact of a common haplotype variant in ATP2B4 using in vitro assays that model erythrocyte stage malaria pathogenesis. Ninety-six donors representing homozygote (carriers of the minor allele, C/C), heterozygote (T/C) and wildtype (T/T) carriers of the tagging SNP rs1541252 were selected from a cohort of over 12,000 participants in the Keneba Biobank. RESULTS: Red blood cells (RBCs) from homozygotes showed reduced PMCA4b protein expression (mean fluorescence intensities (MFI = 2428 ± 124, 3544 ± 159 and 4261 ± 283], for homozygotes, heterozygotes and wildtypes respectively, p < 0.0001) and slower rates of calcium expulsion (calcium t½ ± SD = 4.7 ± 0.5, 1.8 ± 0.3 and 1.9 ± 0.4 min, p < 0.0001). Growth of a Plasmodium falciparum laboratory strain (FCR3) and two Gambian field isolates was decreased in RBCs from homozygotes compared to heterozygotes and wildtypes (p < 0.01). Genotype group did not affect parasite adhesion in vitro or var-gene expression in malaria-infected RBCs. Parasite growth was inhibited by a known inhibitor of PMCA4b, aurintricarboxylic acid (IC50 = 122uM CI: 110-134) confirming its sensitivity to calcium channel blockade. CONCLUSION: The data support the hypothesis that this ATP2B4 genotype, common in The Gambia and other malaria-endemic areas, protects against severe malaria through the suppression of parasitaemia during an infection. Reduction in parasite density plays a pivotal role in disease outcome by minimizing all aspects of malaria pathogenesis. Follow up studies are needed to further elucidate the mechanism of protection and to determine if this ATP2B4 genotype carries a fitness cost or increases susceptibility to other human disease.


Assuntos
Malária Falciparum , ATPases Transportadoras de Cálcio da Membrana Plasmática , Adulto , Humanos , Cálcio/metabolismo , Estudos Transversais , Eritrócitos/parasitologia , Gâmbia , Malária Falciparum/genética , ATPases Transportadoras de Cálcio da Membrana Plasmática/genética , ATPases Transportadoras de Cálcio da Membrana Plasmática/metabolismo , Plasmodium falciparum , Polimorfismo de Nucleotídeo Único
18.
Sci Rep ; 13(1): 745, 2023 Jan 13.
Artigo em Inglês | MEDLINE | ID: mdl-36639503

RESUMO

The fraction of red blood cells adopting a specific motion under low shear flow is a promising inexpensive marker for monitoring the clinical status of patients with sickle cell disease. Its high-throughput measurement relies on the video analysis of thousands of cell motions for each blood sample to eliminate a large majority of unreliable samples (out of focus or overlapping cells) and discriminate between tank-treading and flipping motion, characterizing highly and poorly deformable cells respectively. Moreover, these videos are of different durations (from 6 to more than 100 frames). We present a two-stage end-to-end machine learning pipeline able to automatically classify cell motions in videos with a high class imbalance. By extending, comparing, and combining two state-of-the-art methods, a convolutional neural network (CNN) model and a recurrent CNN, we are able to automatically discard 97% of the unreliable cell sequences (first stage) and classify highly and poorly deformable red cell sequences with 97% accuracy and an F1-score of 0.94 (second stage). Dataset and codes are publicly released for the community.


Assuntos
Anemia Falciforme , Redes Neurais de Computação , Humanos , Eritrócitos , Aprendizado de Máquina , Movimento (Física)
19.
BMC Pediatr ; 23(1): 19, 2023 Jan 13.
Artigo em Inglês | MEDLINE | ID: mdl-36639749

RESUMO

BACKGROUND: The hemolytic nature of hemolytic disease of the newborn (HDN) is described as the abnormal destruction and decomposition of red blood cells, causing heterogeneous manifestations such as abnormal red blood cell volume and morphology. Mean corpuscular volume (MCV) and red blood cell volume distribution width (RDW) are commonly used parameters related to red blood cell volume. Total serum bilirubin (TSB) is routinely monitored among newborns. This study aims to explore the value of MCV and RDW, combined with TSB, to improve the efficiency of HDN diagnosis. METHODS: Three hundred eighty-eight children with HDN and 371 children with non-HDN pathological jaundice who were diagnosed and treated in the neonatal department of our hospital from January 2019 to December 2020 were included in the study. Clinical data collected include examination results of laboratory indicators, such as MCV, coefficient of variation of red blood cell volume distribution width (RDW-CV), standard deviation of red blood cell volume distribution width (RDW-SD), and TSB. The differences in the indicators between the two groups of children were retrospectively analyzed. RESULTS: 1) The detection rate of HDN in children in the early group was higher than that in the late group (P < 0.001). 2) The early-stage group had lower TSB levels and higher values of MCV, RDW-CV and RDW-SD (P < 0.001). Compared with the children in the non-HDN group, the indices in the HDN group were higher in the early stage (P < 0.001). 3) In the early stage, the TSB, MCV, RDW-CV, and RDW-SD were positively correlated with the diagnosis of HDN (P < 0.001). Early monitoring of TSB, MCV, RDW-CV and RDW-SD was valuable for HDN detection, the area under the curve (AUC) was 0.729, 0.637, 0.715, and 0.685, respectively (P < 0.001). 4) After a binary logistic analysis at TSB > 163.3 µmol/L, MCV > 96.35fL, and RDW-CV > 16.05%, the diagnosis rate of HDN increased (P < 0.001). The AUC of the HDN detected using the combined indicators was 0.841. CONCLUSION: At MCV > 96.35fL or RDW-CV > 16.05%, children with jaundice in three days of birth (especially children with TSB > 163.3 µmol/L) should be screened for HDN. A combination of TSB, MCV, and RDW-CV can improve the early detection rate of HDN, contribute to reduce the readmission rate and risk of hyperbilirubinemia.


Assuntos
Índices de Eritrócitos , Icterícia , Criança , Humanos , Recém-Nascido , Estudos Retrospectivos , Eritrócitos , Icterícia/diagnóstico , Bilirrubina
20.
Indian J Pathol Microbiol ; 66(1): 188-190, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-36656239

RESUMO

Introduction: Autoimmune hemolytic anemia (AIHA) is a rare complication of chicken pox. In adults, such AIHA is due to warm antibodies. We report a case of cold antibody AIHA following chicken pox in a young female. Case Report: A 24-year-old female presented with clinical and laboratory features consistent with hemolytic anemia 5 days after the onset of chicken pox. Her hemoglobin levels dropped rapidly during the course of admission from 7.9 to 3.8 g/dL with evidence of ongoing haemolysis in the form of rising total and indirect bilirubin. Peripheral smear revealed red cell agglutinates and erythrophagocytosis. Direct Coomb's test (DCT) was positive for C3d suggesting a cold antibody AIHA. Since test for Donath Landsteiner antibody was negative, and all other tests for common causes of hemolytic anemia were noncontributory, it was presumed to be due to chicken pox. The fulminant course necessitated a short course of oral steroids to which she responded with rise in hemoglobin and no further hemolysis. Two weeks later, her peripheral smear was normal and DCT negative. Conclusion: In patients presenting with acute onset anemia following chicken pox, possibility of cold antibody AIHA must be considered and appropriate testing pursued. Despite lack of empiric evidence, short course of steroids may be beneficial if drop in hemoglobin is rapid with evidence of fulminant hemolysis, showing no abatement after first week.


Assuntos
Anemia Hemolítica Autoimune , Varicela , Feminino , Humanos , Anemia Hemolítica Autoimune/etiologia , Anemia Hemolítica Autoimune/complicações , Varicela/complicações , Varicela/diagnóstico , Eritrócitos , Hemoglobinas , Hemólise , Adulto Jovem
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