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A nonlinear model, based on the area difference elasticity theory, has been developed to predict the sequence of stomatocyte–discocyte–echinocyte transformation in red blood cells. This model coarsely grains the cell membrane into a triangular network, accounting for the shear deformation of membrane skeleton, the area dilation, volume variation, bending deformation, and area difference deformation of lipid bilayer. It exhibits linear behavior under small deformations and transits to nonlinear behavior under large deformations, mirroring the biomechanical response of the cell that is susceptible to small deformations but significantly resists large deformations. The model parameters are calibrated by determining the biconcave equilibrium shape from an ellipsoidal stress-free configuration. After calibration, the model is utilized to predict the stomatocyte–discocyte–echinocyte transformation and is compared with the previously published experimental observations and the numerical results. It has been shown that the equilibrium shapes of a red blood cell are achieved in a self-equilibrium of spring lengths, as well as the balance between the triangle areas and surface area, and the interplay among dihedral curvature and area differences. The nonlinear model is believed to be capable of predicting the deformation behavior of red blood cells in diverse shape-transforming scenarios, such as in microvascular circulation and microfluidic devices. [ABSTRACT FROM AUTHOR]

It is important to understand the dynamics of red blood cells (RBCs) in blood flow. This requires the formulation of coarse-grained RBC models that reproduce the hydrodynamic properties of blood accurately. One of the models that successfully reproduces the rheology and morphology of blood has been proposed by Fedosov et al. [Comput. Methods Appl. Mech. Eng. 199, 1937–1948 (2010)]. The proposed RBC model contains several parameters whose values are determined by either various experiments or physical requirements. In this study, we developed a new method of determining parameter values precisely from the fluctuations of the RBC membrane. Specifically, we studied the relationship between the spectra of the fluctuations and model parameters. Characteristic peaks were observed in the spectra, whose peak frequencies were dependent on the parameter values. In addition, we investigated the spectra of the radius of gyration. We identified the peaks originating from the spring potential and the volume-conserving potential appearing in the spectra. These results lead to the precise experimental determination of the parameters used in the RBC model. [ABSTRACT FROM AUTHOR]

Epidemiological studies reported associations between ozone (O 3) exposure and cardiovascular diseases, yet the biological mechanisms remain underexplored. Hypoxia is a shared pathogenesis of O 3 -associated diseases; therefore, we hypothesized that O 3 exposure may induce changes in hypoxia-related markers, leading to adverse cardiovascular effects. This study aimed to investigate associations of short-term O 3 exposure with hypoxic biomarkers and arterial stiffness. We conducted a panel study involving 210 young healthy residents in 2 cities at different altitudes on the Qinghai-Tibetan Plateau in China, where O 3 concentrations are high and particulate pollution is low. Participants underwent 4 repeated visits to assess ambient O 3 exposure levels, hypoxic biomarkers, and arterial stiffness. We applied linear mixed-effects models to assess the associations of O 3 exposure (lag1 to lag1-7 days) with hypoxic biomarkers and arterial stiffness, adjusted for confounders. Mediation analyses explored the hypoxia's role in O 3 -related arterial stiffness changes. We further examined effect modification by residence altitude and the robustness of results by including PM 2.5 (particulate matter ≤2.5 μm in aerodynamic diameter) or NO 2 in 2-pollutant models. O 3 exposure 1 to 7 days before visits was significantly associated with changes in multiple hypoxic biomarkers. A 10-ppb increase in O 3 exposure was linked to significant decreases in oxygen saturation (SpO 2) and increases in red blood cell count (RBC), hemoglobin concentration, and hematocrit, with maximum changes by −0.42%, 0.92%, 0.97%, and 1.92%, respectively. Laboratory analysis of mRNA and protein markers consistently indicated that O 3 exposure activated the hypoxia-inducible factor 1 (HIF-1) signaling pathway. Additionally, a 10-ppb increase in O 3 corresponded to a 1.04% to 1.33% increase in carotid-femoral pulse wave velocity (cfPWV), indicating increased arterial stiffness. RBC, hemoglobin concentration, and hematocrit increases significantly mediated the O 3 –cfPWV association, whereas the SpO 2 reduction had an insignificant mediating effect. Associations of O 3 with hypoxic biomarkers varied by altitude. The higher altitude group showed delayed associations with SpO₂ and HIF-1 expression but stronger associations with RBC indices. These associations remained robust after adjusting for copollutants. O 3 exposure may reduce oxygen availability, prompting compensatory increases in red blood cells and hemoglobin, which exacerbate arterial stiffening. These findings provide new insights into the mechanisms underlying O 3 -induced cardiovascular injury. [Display omitted] [ABSTRACT FROM AUTHOR]

The current study investigates the combined effect of different dietary vitamins E and selenium (sodium selenite, Se) on the growth, survival, feed utilization, nutrients digestibility, body composition, activity test evaluation, intestinal bacterial load, and hematological indices of European seabass, Dicentrarchus labrax fry. A feeding experiment was conducted in D. labrax using five different diets with the same proximate composition. Introvit-ES100 oral® (ES) provides 50 mg/mL vitamin E and 0.5 mg/mL selenium, a source of VE and Se. The only distinction between the diets was the level of VE and SE. Each diet was fed to triplicate groups of fish (initial weight: 0.13 g) for 84 days. The control diet (ES0%) did not contain any added ES. Diets 2–5 included varying: 50: 0.5 mg/kg (ES1%), 100: 1.0 mg/kg (ES2%), 150: 1.5 mg/kg (ES3%), and 200: 2.0 mg/kg (ES4%). The water quality parameters were temperature 22, with a pH range of 7.9–8.2, the salinity range is 31.3–32.4 ppt, and the nitrogen concentrations are as follows: N at 0.54, NH3 at 0.73, and NH4 at 0.77. The results showed that seabass fry had the highest FBW, WG, SGR, FL, and K values when fed 150: 1.5 mg kg−1 of VE and Se, respectively (ES3%). Fish provided the ES4% diet had the highest survival (%) and showed inferior growth performance. Apparent digestibility coefficient analysis, which included protein, lipid, and carbohydrate digestibility, revealed that the highest values were recorded in fish fed the ES3% diets. The highest body protein was recorded in ES3%; the lowest lipid content value was recorded in ES4%. The highest white blood cell count, red blood cell count, and hematocrit values were recorded in ES3%. While the highest hemoglobin values were recorded in ES4%. The highest activity test value was recorded in ES2% and ES3% diets. The lowest Vibrio sp. count was recorded in ES3%. While the Aeromonas sp. was not detected in all experimental treatments. The results indicated that supplementing the diet with 150 mg kg−1 of VE and 1.5 mg kg−1 of Se improved growth performance, feed utilization, and survival rates, resulting in increased production of D. labrax fry after weaning in marine hatcheries. [ABSTRACT FROM AUTHOR]

Background: The translocation of photoassimilates is a critical process that links the source and sink in plants, playing an irreplaceable role in maintaining source-sink balance, ensuring plant growth and development, and the formation of yield. Nevertheless, the mechanisms underlying the translocation of photosynthetic products in macroalgae are yet to be fully understood. The purpose of this study is to reveal the role of endocytosis in the translocation of photosynthetic products in the marine red alga Gracilariopsis lemaneiformis by investigating the uptake of photosynthetic products by endocytosis and the impact of endocytic activity on cellular ultrastructure, photosynthesis, and growth. Results: This study discovered that the endocytic activity in non-epidermal cells (NEC, sink cells) of G. lemaneiformis is significantly higher than that in epidermal cells (EC, source cells). NEC is capable of internalizing a greater amount of extracellular carbohydrates, such as sucrose, via endocytosis compared to EC. Further inhibition of endocytic activity in G. lemaneiformis using EIPA resulted in a significant reduction in the content of floridean starch within NEC, whereas the decrease in floridean starch content in EC was not statistically significant. Inhibition of endocytic activity led to an initial decline in photosynthetic efficiency of algal thalli within a few hours, which was followed by an increase as inhibition duration extended, yet the growth rate of the thalli remained substantially suppressed. Conclusions: These findings indicate that endocytosis in G. lemaneiformis plays a role in regulating the cellular uptake of extracellular photoassimilates, which in turn influences the storage substances in sink cells and the overall growth and development of the algae. This study sheds new light on the regulatory mechanisms governing photoassimilate translocation in macroalgae. [ABSTRACT FROM AUTHOR]

Ergothioneine (ERG) is a natural sulfur-containing amino acid found in many organisms, including humans. It accumulates at high concentrations in red blood cells and is distributed to various organs, including the brain. ERG has numerous health benefits and antioxidant capabilities, and it has been linked to various human physiological processes, such as anti-inflammatory, neuroprotective, and anti-aging effects. Accurate, rapid, and cost-effective quantification of ERG levels in human biofluids is crucial for understanding its role in oxidative stress-related diseases. Surface-enhanced Raman scattering (SERS) is an effective approach for measuring compounds at concentrations similar to those at which ERG is present in serum. However, while SERS has been used to characterize or detect ERG, quantification has not yet been achieved due to the variability in the signal enhancement that can arise during sample preparation and analysis. This study introduces a highly efficient and reliable technique for quickly (20 min is typical per sample) measuring ERG levels in human serum using SERS. This employs an internal standard highly specific for ERG which resulted in limit of quantification values of 0.71 μM. To validate this approach, we analysed real human serum with unknown ERG levels as a blind test set and primary reference levels of ERG were produced using a targeted UHPLC-MS/MS reference method. [ABSTRACT FROM AUTHOR]

• HO-1 and p-NF-kB p65 were increased in brain tissue of ICH mice. • Tat-NBD enhanced protective effect of HO-1 on nerve injury and hematoma clearance after ICH. • Tat-NBD enhanced promoting effect of HO-1 on M2 polarization of microglia after ICH. • HO-1 induced M2 polarization and phagocytosis via inhibiting NF-kB. • HO-1/NF-kB reduced neuronal damage via inducing microglia M2 polarization and phagocytosis. Microglia polarization plays a crucial role in inflammatory injury of brain following intracerebral hemorrhage (ICH). Heme oxygenase-1 (HO-1) has demonstrated protective properties against inflammation and promote hematoma clearance after ICH. The objective of this study was to explore impacts of HO-1 on microglia polarization and phagocytosis after ICH, along with the underlying mechanism. ICH model was constructed in C57BL/6 mice. Neurological deficit of ICH mice was evaluated. HE detected pathological changes of mouse brain tissue. Immunofluorescence staining tested co-localization between HO-1 or NF-κB p65 and IBA1. The expressions of gene and proteins were detected by RT-qPCR and Western blot, respectively. Flow cytometry determined microglial polarization phenotype and neuron apoptosis. Cell viability of neuron was assessed by CCK-8. Red blood cells labeled by PKH-26 and co-cultured with microglia for examining microglial erythrophagocytosis. Both HO-1 and NF-κB p65 phosphorylation were elevated in brain tissues of ICH mice. ZnPP, a HO-1 inhibitor, could exacerbate microglial M1 polarization and nerve injury, as well as repress microglial erythrophagocytosis in vitro and hematoma clearance in vivo. On the contrary, Tat-NBD, a NF-κB inhibitor, greatly suppressed microglial M1 polarization, and induced M2 polarization and microglial erythrophagocytosis, thus improving nerve injury and hematoma clearance after ICH. Notably, it was observed that NF-κB p65 could be activated by ZnPP treatment, and the regulatory roles of ZnPP on microglial polarization and erythrophagocytosis after ICH in vivo and in vitro were all diminished by Tat-NBD. Therefore, our data demonstrated that HO-1 alleviated nerve injury and induced M2 polarization and phagocytosis of microglia after ICH via inhibiting NF-κB signaling pathway, which could provide deepen the pathological understanding of ICH and provide potential intervention targets and drug candidate for ICH. [ABSTRACT FROM AUTHOR]

Red blood cell distribution width (RDW) is a prognostic factor in various disorders. This study aimed to assess the prognostic value of RDW in patients undergoing amputation for diabetic foot. We retrospectively analyzed data on 415 patients who underwent diabetic foot amputation between January 2009 and January 2019. After establishing an optimal cutoff value of preoperative RDW for all-cause mortality, univariable and multivariable analyses with Cox proportional hazard model for survivorship and logistic regression analysis for prolonged hospital length of stay (> 30 days) were performed to identify significant prognostic factors. A preoperative RDW of 14.5% was the optimal cutoff value for predicting all-cause mortality. RDW ≥ 14.5% was significantly associated with increased all-cause mortality (hazard ratio, 2.55; 95% confidence interval [CI], 1.55–4.19; P < 0.001) on multivariable Cox proportional model analysis. Preoperative RDW ≥ 14.5% was also associated with a prolonged hospital length of stay after surgery (odds ratio, 2.17; 95% CI, 1.29–3.66; P = 0.004). Higher preoperative RDW was an independent predictive factor for increased all-cause mortality and prolonged hospital length of stay after diabetic foot amputation. These results suggest that RDW may be a useful laboratory parameter for risk stratification in patients undergoing amputation for diabetic foot. [ABSTRACT FROM AUTHOR]

Background: Haemolytic disease of the foetus and newborn (HDFN) is an immune disorder driven by maternal alloimmunisation against foetal/newborn red blood cell antigens. HDFN can cause significant morbidity and mortality, with symptoms in the foetus ranging from mild anaemia to hydrops fetalis. While in newborns, HDFN can lead to severe forms of neonatal hyperbilirubinaemia and kernicterus. This systematic review (SR) aimed to identify and summarise real-world evidence (RWE) related to the patient burden/experience and economic burden of HDFN. Methods: Electronic database searches supplemented by handsearching of grey literature, were conducted to identify studies that reported the clinical patient burden/experience, and economic burden of HDFN in Europe, the Middle East, and Africa (EMEA). Data from eligible studies were summarised in a narrative synthesis due to heterogeneity between studies. Results: A total of 26 relevant publications were identified for inclusion in the SR, consisting of one study that directly measured Health Related Quality of Life, 9 studies reporting on proxy outcomes for patient burden and 18 studies reporting on economic burden (this includes two double-counted studies reporting more than one outcome type). Neurodevelopment, academic development, behaviour and personality were assessed as proxy outcomes for patient burden given the limited identification of patient-reported outcome data. These studies suggested potential neurodevelopmental impairments in children with HDFN. Despite these indirect insights into patient burden, identified data were limited and results should be interpreted with consideration of the inherent heterogeneity in design and endpoints assessed across RWE studies. Economic burden data were primarily limited to healthcare resource use outcomes, with limited reported data on healthcare costs, it is difficult to draw notable conclusions on the true economic burden of HDFN. Conclusions: The current SR provides a clear summary of the available evidence for the patient experience and economic burden of HDFN. While the limited evidence indicates that HDFN does confer a significant burden on patients, the review identifies the need for further well-powered and representative observational studies using well-defined outcome measures to aid a greater understanding of the burden and experience of HDFN. Trial registration: The protocol for this systematic review was registered in PROSPERO CRD42022328444. [ABSTRACT FROM AUTHOR]

Peptide-based drugs often fail in clinical trials due to their toxicity or hemolytic activity against red blood cells (RBCs). Existing methods predict hemolytic peptides but not the concentration (HC50) required to lyse 50% of RBCs. This study develops classification and regression models to identify and quantify hemolytic activity. These models train on 1926 peptides with experimentally determined HC50 against mammalian RBCs. Analysis indicates that hydrophobic and positively charged residues were associated with higher hemolytic activity. Among classification models, including machine learning (ML), quantum ML, and protein language models, a hybrid model combining random forest (RF) and a motif-based approach achieves the highest area under the receiver operating characteristic curve (AUROC) of 0.921. Regression models achieve a Pearson correlation coefficient (R) of 0.739 and a coefficient of determination (R²) of 0.543. These models outperform existing methods and are implemented in HemoPI2, a web-based platform and standalone software for designing peptides with desired HC50 values (http://webs.iiitd.edu.in/raghava/hemopi2/). Developed models predict and quantify hemolytic activity of peptides. A hybrid model achieves AUROC of 0.921, regression models show R = 0.739. Implemented in HemoPI2, enabling peptide design with desired HC50 values. [ABSTRACT FROM AUTHOR]

Background: Malaria parasites establish new permeation pathways (NPPs) at the red blood cell membrane to facilitate the transport of essential nutrients from the blood plasma into the infected host cell. The NPPs are critical to parasite survival and, therefore, in the pursuit of novel therapeutics are an attractive drug target. The NPPs of the human parasite, P. falciparum, have been linked to the RhopH complex, with the monoallelic paralogues clag3.1 and clag3.2 encoding the protein RhopH1/CLAG3 that likely forms the NPP channel-forming component. Yet curiously, the combined knockout of both clag3 genes does not completely eliminate NPP function. The essentiality of the clag3 genes is, however, complicated by three additional clag paralogs (clag2, clag8 and clag9) in P. falciparum that could also be contributing to NPP formation. Methods: Here, the rodent malaria species, P. berghei, was utilised to investigate clag essentiality since it contains only two clag genes, clagX and clag9. Allelic replacement of the regions encompassing the functional components of P. berghei clagX with either P. berghei clag9 or P. falciparum clag3.1 examined the relationship between the two P. berghei clag genes as well as functional orthology across the two species. An inducible P. berghei clagX knockout was created to examine the essentiality of the clag3 ortholog to both survival and NPP functionality. Results: It was revealed P. berghei CLAGX and CLAG9, which belong to two distinct phylogenetic clades, have separate non-complementary functions, and that clagX is the functional orthologue of P. falciparum clag3. The inducible clagX knockout in conjunction with a guanidinium chloride induced-haemolysis assay to assess NPP function provided the first evidence of CLAG essentiality to Plasmodium survival and NPP function in an in vivo model of infection. Conclusions: This work provides valuable insight regarding the essentiality of the RhopH1 clag genes to the NPPs functionality and validates the continued investigation of the RhopH complex as a therapeutic target to treat malaria infections. [ABSTRACT FROM AUTHOR]

Objective: This study aimed to investigate the correlation between the Hemoglobin-to-Red Blood Cell Distribution Width Ratio (HRR) and Peripheral Artery Disease (PAD) prevalence, utilizing data from the National Health and Nutrition Examination Survey (NHANES) between 1999 and 2004. Methods: The study employed a cross-sectional design, analyzing data from 5,196 participants aged 40 and above. PAD was diagnosed using the Ankle-Brachial Index (ABI), with ABI less than 0.9 indicating PAD. HRR, calculated as the ratio of hemoglobin (HB) to red blood cell distribution width (RDW), was stratified into quartiles. Covariates included demographic and clinical variables such as BMI, lipid profiles, and diabetes status. Logistic regression analysis was conducted to assess the relationship between HRR and PAD, adjusting for potential confounders. Results: The study found that higher HRR quartiles were associated with a decreased risk of PAD. After adjusting for confounders, the odds ratios for PAD in relation to the second, third, and fourth quartiles of HRR compared to the first quartile were 0.71, 0.62, and 0.44, respectively (P < 0.001). A one-unit increase in HRR corresponded to a 56% reduction in the probability of PAD. ROC analysis indicated HRR as a stronger protective factor for PAD compared to other variables. Stratified analyses revealed that younger age and lower BMI amplified the protective effect of HRR on PAD. Conclusion: The study demonstrated a significant inverse relationship between HRR and PAD, suggesting that HRR may serve as a protective factor against PAD. This finding highlights the potential role of HRR in the pathogenesis of PAD and its clinical implications. [ABSTRACT FROM AUTHOR]

Renal anemia stems mainly from chronic inflammation with elevated hepcidin levels, iron deficiency, and reduced red blood cell lifespan. Inadequate erythropoietin (EPO) production, worsened kidney function, leads to symptoms such as low energy, fatigue, and impaired physical function, significantly affecting patients' quality of life. We conducted a comprehensive search across electronic databases including PubMed, Embase, Cochrane Library, Chinese National Knowledge Infrastructure, Airiti library, and Wanfang, to compile recent clinical trials and pilot studies on conventional and complementary alternative medicine approaches for renal anemia. This discussion focuses on the hypoxia-inducible factor prolyl hydroxylase domain (HIF-PHD) axis theory, from lab research to clinical applications. It explores non-extracorporeal treatments for renal anemia, including pharmaceutical interventions, dietary strategies, and complementary and alternative medicine (CAM). The article details the effects of Roxadustat, Ferumoxytol, and Epodion. Clinical studies show that modulating the gut microbiome can reduce inflammation and improve renal anemia. Clinical trials suggest that CAM therapy can improve renal anemia through mechanisms such as enhanced iron metabolism, anti-inflammatory effects, reduced hepcidin levels, and increased EPO and HIF expressions. By synthesizing this information, the review aims to furnish valuable insights and treatment recommendations aimed at ameliorating renal anemia in individuals grappling with chronic kidney disease. [ABSTRACT FROM AUTHOR]

Research on the effects of melatonin on erythrocyte deformability has yielded mixed results. While some studies reported improvements, others found no effect, and a few even noted a deterioration in deformability. Moreover, the impact of melatonin may vary between healthy erythrocytes and those subjected to oxidative stress. This study investigated the dose-dependent effects of melatonin on erythrocytes under baseline conditions and oxidative stress, using both pre- and post-stress incubation protocols. Oxidative damage was induced with tert-butyl hydroperoxide (TBHP), and its extent was assessed via dichlorofluorescein fluorescence. Erythrocyte deformability was measured using ektacytometry, and osmotic resistance was assessed through hemolytic assays. The results showed that incubation with TBHP led to a dose-dependent decline in both erythrocyte deformability and osmotic resistance. While melatonin treatment had no observable effect on intact erythrocytes, it enhanced deformability in oxidatively damaged erythrocytes when administered before oxidative stress was induced. However, the beneficial effect was not evident when melatonin was applied after oxidative damage. Additionally, melatonin incubation had no impact on the ability of erythrocytes to resist the hypotonic environment. In conclusion, this study supports the notion that the antioxidant properties of melatonin can improve erythrocyte functional status, as reflected by enhanced deformability, but not osmotic resistance. Notably, this effect was observed only in erythrocytes that were exposed to oxidative damage after melatonin incubation, not in intact cells. [ABSTRACT FROM AUTHOR]

Atherosclerosis is caused by injury to the blood arteries and progressive oxidative stress. Blood cells play an important role in its development; thus, their protection is important. Naringenin (N) is documented to possess a protective action against atherosclerosis, and we hypothesize that its derivatives, naringin (Nr) and naringin dihydrochalcone (Nd), with slightly different structures, possess similar or better activity. Therefore, this research aimed to find the mechanism of protective action of N, Nr and Nd in relation to erythrocytes, peripheral blood mononuclear cells (PBMCs) and platelets in terms of their potential anti-atherosclerotic effect. Moreover, their physicochemical properties and the interaction of flavonoids with liposomes were studied. All flavonoids protected erythrocytes from AAPH- and H2O2-induced oxidation to varying degrees. None of them had a destructive effect on erythrocyte membrane, and they did not impact the metabolic activity of PBMC and platelets. Nr and Nd inhibited collagen-induced platelet aggregation better in tested concentrations than N. Studied compounds did not induce liposome aggregation, but N and Nd changed their dipole potential. Obtained results show that Nd possesses slightly better activity than N and may have a better potential health effect on blood cells, which is very important in the design of anti-atherosclerotic therapeutics. [ABSTRACT FROM AUTHOR]

Palladium(II) complexes with tris(2-carboxyethyl)phosphine (PdTCEP) show promise for biomedical applications due to their distinct chemical characteristics. This study explored the toxicity of PdTCEP towards normal human cells and examined its interactions with model cell membranes. Two cell types were used to evaluate cytotoxicity: human microvascular endothelial cells (HMEC-1) and red blood cells (RBCs). In HMEC-1 cells, PdTCEP reduced survival to about 80% at 15 µM, with the most significant drop—down to 40%—occurring at 40 µM. The production of reactive oxygen species (ROS) increased in a manner dependent on both dose and time, especially after 72 h of incubation. Despite these effects, PdTCEP caused only minor hemolysis in RBCs, with hemolysis levels staying below 10% even at higher concentrations. Fluorescence anisotropy measurements showed that PdTCEP minimally affects the hydrophobic core of the lipid bilayer, with slight changes observed at concentrations above 40 µM. Generalized polarization (GP) analysis indicated a slight decrease in lipid polar head packing with increasing PdTCEP concentration. Complementary FTIR analysis supported these findings by providing detailed insights into PdTCEP-membrane interactions. This research underscores PdTCEP's selective cytotoxicity and structural effects on membranes, suggesting its promise for more in-depth biological and pharmacological studies. [ABSTRACT FROM AUTHOR]

The use of nanoparticles is becoming increasingly apparent in a growing number of medical fields. To exploit the full potential of these particles, it is essential to examine their behavior in the blood and their possible interactions with blood cells. Dendritic core multi-shell DendroSol™ nanoparticles (DS-NPs) are able to penetrate into viable layers of human skin, but nothing is known about their interaction with blood cells. In the present study, we analyze the effect of DS-NPs on red blood cells (RBCs) using confocal laser scanning microscopy (CLSM), flow cytometry, sedimentation rate analysis, spectrophotometry, and hemolysis assays. DS-NPs labeled with Nile red (NR) were added to RBC suspensions and their accumulation in the area of the RBC membranes was demonstrated by CLSM as well as by flow cytometry. In the presence of DS-NPs, the RBCs show an increased sedimentation rate, which also confirms the binding of the NPs to the cells. Interestingly, in the presence of DS-NPs, the RBCs are stabilized against hypotonic hemolysis as well as against the hemolytic action of Triton X-100. This proven anti-hemolytic effect could be utilized to enhance the circulation time of RBCs loaded with drugs for prolonged sustained release and drug delivery with enhanced bioavailability. [ABSTRACT FROM AUTHOR]

Sickle cell disease (SCD) affects two-thirds of African and Indian children. Understanding the molecular mechanisms contributing to oxidative stress may be useful for therapeutic development in SCD. We evaluated plasma elemental levels of Indian SCD patients, trait, and healthy controls (n = 10 per group) via inductively coupled plasma mass spectrometry. In addition, erythrocyte metabolomics of Indian SCD and healthy (n = 5 per group) was carried out using liquid chromatography-mass spectrometry. Followed by assessment of antioxidant defense enzymes namely glutathione reductase (GR), superoxide dismutase (SOD), and catalase (CAT) in erythrocytes and plasma of Indian SCD patients (n = 31) compared with trait (n = 10) and healthy (n = 10). In SCD plasma an elevated plasma 24 Mg, 44Ca, 66Zn, 208Pb, 39K and reduced 57Fe, 77Se, and 85Rb levels indicated higher hemolysis and anemia. Erythrocyte metabolome of SCD patients clustered separately from healthy revealed 135 significantly deregulated metabolic features, including trimethyllysine, pyroglutamate, glutathione, aminolevulinate, and d-glutamine, indicating oxidative stress and membrane fragility. Repressed GR, SOD, and CAT activities were observed in SCD patients of which GR and CAT activities did not change under hypoxia. These findings lead to the hypothesis that SCD-associated metabolic deregulations and a shift to ATP-consuming aberrant γ-glutamyl cycle leads to anemia, dehydration, oxidative stress, and hemolysis driving the biomechanical pathophysiology of erythrocyte of SCD patients. Antioxid. Redox Signal. 42, 199–211. [ABSTRACT FROM AUTHOR]

Background: The ratio of red blood cell distribution width (RDW) to platelet ratio (RPR) may have prognostic value in several inflammation-related diseases. However, few studies have been conducted on the value of RPR for predicting the severity of pyogenic liver abscess (PLA). Methods: Patients receiving the diagnosis of PLA from February 2013 to December 2022 were enrolled in this retrospective study. We collected data related to baseline characteristics and laboratory results within the first 24 hours the  of admission. The receiver operating characteristic curve and the area under the curve (AUC) were used to evaluate the predictive ability of different indicators for severity in PLA. Results: A total of 278 patients were enrolled. For the prediction of sepsis in PLA, RPR had the highest AUC (0.83; 95% confidence interval [CI], 0.78–0.89) with a sensitivity of 0.78 and specificity of 0.82. For the prediction of septic shock, RPR also had the highest AUC (0.74; 95% CI, 0.60–0.88) with a sensitivity of 0.67 and specificity of 0.79. The best cutoff value for RPR to predict sepsis was 0.08 and to predict septic shock was 0.11. Conclusions: An increase in RPR level serves as a useful indicator with a predictive capacity for severity in PLA. [ABSTRACT FROM AUTHOR]

Introduction: Anemia is a prevalent complication of chronic kidney disease (CKD), primarily due to insufficient erythropoietin (EPO). Pegmolesatide (by Hansoh Pharma) is currently the only marketed long-acting EPO mimetic peptide (EMP) for the treatment of anemia in both dialysis and non-dialysis CKD patients. This paper aimed to explore the long-acting erythropoiesis stimulating molecular mechanism of Pegmolesatide. Methods: In vitro assays were utilized to assess Pegmolesatide erythropoietin receptor (EPOR) affinity, competitive binding, cell proliferation/survival, apoptosis, cell surface receptor expression, and signal transduction. Pharmacokinetics (PK) and Pharmacodynamics (PD) parameters were evaluated in BALB/c mice following single administration. Furthermore, two Phase II clinical trials in dialysis and non-dialysis chronic kidney disease (CKD) patients with anemia, respectively CTR20140533 and CTR20140539, assessed PK-PD and safety following repeated administration. Results: In vitro Pegmolesatide demonstrated enhanced binding stability and prolonged residency at EPOR, surpassing erythropoiesis-stimulating agents (ESAs) rHuEPO and Darbepoetin. This sustained EPOR binding facilitated heightened endogenous EPOR expression post-drug withdrawal, maintaining downstream signal transduction pathways (JAK2/STAT5, ERK1/2 MAPK) for erythropoiesis. Pegmolesatide promoted UT-7 cell proliferation & survival and suppressed apoptosis. Following a single 0.08 mg/kg dose of Pegmolesatide in BALB/c mice, reticulocyte count, red blood cells, hemoglobin, and hematocrit persisted at elevated levels 4-6 days after administration. In the two clinical Phase II studies dose-dependent increases in hemoglobin and prolonged response duration were independently observed. Pegmolesatide showed significant PK-PD dual prolongation effects and was well tolerated. Adverse events were mild and manageable, with no reports of severe anaphylaxis. Discussion: Preclinical and clinical evidence signifies that Pegmolesatide is a unique, potent PEGylated EPO-memetic peptide (EMP) with a prolonged PD efficacy and PK half-life and a good safety-tolerability profile. To elucidate further, future studies will address the endocytosis, intracellular degradation, and ligand release of EPOR subsequent to Pegmolesatide binding, thereby supplementing our understanding of the molecular mechanism at play. Trial registration: Phase IIa clinical study of Pegmolesatide on renal anemia, CTR20140533. Initial Public Notice 14 Jan 2015, http://www.chinadrugtrials.org.cn/clinicaltrials.searchlistdetail.dhtml. Phase II clinical study of Pegmolesatide on renal anemia, CTR20140539. Initial Public Notice 26 Jan 2015, http://www.chinadrugtrials.org.cn/clinicaltrials.searchlistdetail.dhtml. [ABSTRACT FROM AUTHOR]

Blood products frequently are administered to critically ill patients. Considering recent trials and practice variability, a comprehensive review of current evidence was deemed essential to offer pertinent guidance to critical care practitioners. This American College of Chest Physicians (CHEST) guidelines panel examined the literature on RBC transfusions among critically ill patients overall and specific subgroups, including patients with gastrointestinal bleeding, acute coronary syndrome (ACS), cardiac surgery, isolated troponin elevation, and septic shock, to provide evidence-based recommendations. A panel of experts developed six Population, Intervention, Comparator, and Outcome questions addressing RBC transfusions in critically ill patients and performed a comprehensive evidence review. The panel applied the Grading of Recommendations, Assessment, Development, and Evaluations approach to assess the certainty of evidence and to formulate and grade recommendations. A modified Delphi technique was used to reach consensus on the recommendations. The initial search identified a total of 3,082 studies, and after the initial screening, 38 articles were reviewed. Among them, 23 studies met inclusion criteria, comprising 22 randomized controlled trials and one cohort study. Based on the analysis of these studies, the panel formulated two strong and four conditional recommendations. The overall quality of evidence for recommendations ranged from very low to moderate. In most critically ill patients, a restrictive strategy was preferable to a permissive approach because it does not increase the risk of death or complications, but does decrease RBC use significantly. Data from critically ill subpopulations also supported a restrictive approach, except in patients with ACS, for whom favoring a restrictive approach could increase adverse outcomes. [ABSTRACT FROM AUTHOR]

Hypothermic oxygenated perfusion (HOPE) is an emerging technique for donor heart preservation that is currently being studied in multiple clinical trials with promising results. When compared to HOPE for other organs, cardiac protocols involve red blood cell (RBC) supplementation, despite absence of comparative evidence for its benefits. In this perspective paper, we discuss the pros and cons of the addition of RBCs during cardiac HOPE. Although the current clinical results with RBC supplementation during HOPE seem promising, potential downsides of RBC supplementation cannot be ruled out. The impact of supplemented RBCs during cardiac HOPE requires further investigation to improve HOPE protocols, to optimize heart preservation using this promising technology. [Display omitted] [ABSTRACT FROM AUTHOR]

The susceptibility of the human Red Blood Cells (RBCs) under the action of magnetic fields, either serves as a biomarker in medical tests, e.g.. Magnetic Resonance Imaging, Nuclear Magnetic Resonance, Magnetoencephalography, or it is used in diagnostic and therapeutical processes, e.g.. magnetophoresis for cell sorting. In the present manuscript we provide analytical expressions for the magnetic potential and the magnetic field strength vector, when a magnetic field is applied to a RBC, modeled as a two-layered inverted spheroid. We introduce this way in the model the biconcave shape of the RBC and its structure (membrane and cytocol) in a more realistic representation, as until now, the RBC's shape was considered either as a sphere or a spheroid. The solution inside the RBC is obtained in R-separable form in terms of Legendre functions of the first and of the second kind and cyclic trigonometric functions, by applying appropriate boundary conditions on each layer. Our results reveal a non-uniform magnetic field inside the RBC. Parametric study of the solution, for various values of the physical properties of the RBC, is also provided, demonstrating the diamagnetic or the paramagnetic property of the RBC, which is strongly related to the health condition of the blood. The obtained solution may also serve for the justification of experimental results. [ABSTRACT FROM AUTHOR]

Background: Colorectal cancer (CRC) is a prevalent global malignancy with substantial morbidity and mortality. Accurate prognostic evaluation is essential in CRC patient management. This study investigates the prognostic significance of red blood cell count (RBC) and Onodera's prognostic nutritional index (OPNI) in resectable CRC patients. Methods: A retrospective analysis of 210 CRC patients undergoing radical resection (January 2015–January 2017) assessed clinical and hematological factors, including RBC, albumin, hemoglobin, and OPNI. A novel comprehensive biomarker, R-OPNI, combining preoperative RBC with OPNI, was introduced. Correlations with patient survival were analyzed, and R-OPNI's independent prognostic value was assessed through univariate and multivariate Cox models. Predictive ability was compared to other factors using the receiver operating characteristic (ROC) method. Results: Higher RBC levels (≥ 3.9 × 1012/L) and elevated OPNI were associated with significantly improved overall survival. Lower R-OPNI scores (0 or 1) indicated notably poorer survival. Multivariate analysis confirmed R-OPNI's independent prognostic significance (HR: 0.273, 95% CI: 0.098–0.763, p = 0.013). R-OPNI (AUC = 0.732) demonstrated superior predictive value compared to individual prognostic factors. Conclusion: R-OPNI emerges as a robust, independent prognostic predictor for resectable CRC patients, emphasizing the importance of assessing preoperative nutritional status. [ABSTRACT FROM AUTHOR]

Evaporation of blood droplets and diluted blood samples is a topic of intensive research, as it is considered a potential low-cost diagnostic tool. So far, samples with a volume fraction down to a few percent of red blood cells have been studied, and these were reportedly dominated by a "coffee-ring" deposit. In this study, samples with lower volume fractions were used to investigate the growth of the evaporative deposit from sessile droplets in more detail. We observed that blood samples and salt solutions with less than 1% volume fraction of red blood cells are dominated by a central deposit. We characterized the growth process of this central deposit by evaporating elongated drops and determined that it is consistent with the Kardar-Parisi-Zhang process in the presence of quenched disorder. Our results showed a sensitivity of the deposit size to fibrinogen concentration and the shape of red blood cells, suggesting that this parameter could be developed into a new and cost-effective clinical marker for inflammation and red blood cell deformation.   [ABSTRACT FROM AUTHOR]

The list of standard abbreviations for JDS is available at adsa.org/jds-abbreviations-24. Nonstandard abbreviations are available in the Notes. Optimizing rumen development is key to preparing calves for weaning; however, it is unclear what effect rumen development has on calf health via ruminal infusion. This study investigated the effects of ruminal short-chain fatty acid (SCFA) concentrations and pH on hematology, gut morphology, and inflammation of liver and rumen tissues in dairy calves. Holstein calves (n = 32) had the rumen cannulated within the first week of life and at wk 2 were blocked by BW and randomly assigned in a 2 × 2 factorial arrangement of treatments. The treatments included 2 different SCFA concentrations (10 vs. 285 m M) and pH levels (5.2 vs. 6.2), yielding 4 treatment groups: low SCFA, low pH (LS-LP); low SCFA, high pH (LS-HP); high SCFA, low pH (HS-LP); and high SCFA, high pH (HS-HP). On wk 3, 5, and 7, calves underwent a 4-h reticulorumen wash procedure with a physiological buffer containing the various treatments. Blood samples were collected weekly after feeding. Rumen biopsies were taken after each infusion, and liver and rumen samples were harvested at necropsy at wk 7. Data were analyzed with repeated measures, using week, SCFA, and pH as fixed effects. Low rumen pH increased respiration rate, but no other changes in clinical parameters were observed. No differences were detected in red blood cells or platelet numbers. Total white blood cell numbers decreased in the LS-LP group from wk 5 to 7 but increased in the HS-LP group along with hemoglobin and the hematocrit during the same period. Cortisol and BHB levels were unchanged by treatment or time, whereas haptoglobin decreased over time regardless of treatment. Calf liver morphology was unaffected by treatment; ruminal tissue changes associated with epithelial cell sloughing tended to increase with low SCFA, and mucosal eosinophil infiltration increased with high SCFA. Gene expression was unchanged by treatment in both rumen (barrier function and inflammation) and liver (inflammation). Overall, the data demonstrate that stress and inflammatory responses can be affected by changing rumen environments. Notably, these changes are transient as values returned to pretreatment baseline levels after a period as short as a week. [ABSTRACT FROM AUTHOR]

The article "Effects of sotagliflozin on anaemia in patients with type 2 diabetes and chronic kidney disease stages 3 and 4" published in Diabetes, Obesity & Metabolism explores the impact of sotagliflozin on hemoglobin levels in patients with type 2 diabetes and chronic kidney disease. The study found that sotagliflozin increased hemoglobin levels in patients with moderate-severe CKD, regardless of the presence of anemia at baseline. The results suggest that sotagliflozin could be beneficial in managing anemia in this population, in addition to its known cardiorenal protective effects. [Extracted from the article]

The coronavirus disease 2019 (COVID-19) pandemic has significantly impacted the supply and transfusion of blood components. This study aims to evaluate changes in blood collection and transfusions during the period following the nationwide Level 3 alert (May–July 2021). We retrieved usage data for red blood cells (RBC) from the Taiwan National Health Insurance (NHI) database 2019–2021. During the Level 3 alert period, approximately 85% of COVID-19 cases (11,455/13,624) were in Taipei. In Taipei, blood collection declined by 26.34% and RBC transfusions decreased by 17.14% compared to pre-pandemic levels. RBC usage decreased across all service types, with a significant decrease observed in hematology/oncology by 15.62% (-483 patients, -2,425 units). In non-Taipei regions, blood collection declined by 12.54%, rebounding around one month earlier than in Taipei. The decline in RBC transfusions occurred one month later than in Taipei, with a much lower magnitude (4.57%). Strain on the blood supply occurred in May and June in both Taipei and non-Taipei regions. Among 7,532 hospitalized COVID-19 patients, approximately 6.9% patients required a total of 1,873 RBC transfusions. The rapid increase in COVID-19 inpatients did not significantly increase the burden of blood demands. During the Level 3 alert, the most significant decline in both RBC collection and transfusions was observed in Taipei. In non-Taipei regions, the decrease in RBC use was only marginal. Notably, there was a significant decrease in RBC use in hematology/oncology in Taipei. This study supports transfusion specialists in seeking efficient ways to address similar future challenges. [ABSTRACT FROM AUTHOR]

Iron Deficiency Anaemia (IDA) is the most prevalent form of anaemia, affecting 24.8% of the global population. An examination of the complete blood count (CBC) is performed to determine general health and the presence of illnesses. Accurate and timely diagnosis of IDA is essential for proper treatment, yet traditional methods can be time-consuming and costly. This study uses machine learning and computer vision techniques for the automatic identification of hypochromic microcytes from Peripheral Blood Smear (PBS) images to improve IDA diagnosis. Two approaches were implemented: first, a ResNet50 model was used to classify PBS images as Normal or IDA; second, the YOLOv7 object detection model was employed to localize hypochromic microcytes within the images. The YOLOv7 model was tested on 17 images containing 425 instances of hypochromic microcytes and demonstrated superior performance, achieving a test mean Average Precision (mAP) of 89% with faster inference times than ResNet50. By providing localized detection of hypochromic microcytes, YOLOv7 enhances diagnostic accuracy and speed compared to image-level classification. This study highlights the potential of object detection models for improving automated anaemia diagnosis, with implications for faster and more cost-effective healthcare solutions. [ABSTRACT FROM AUTHOR]

Cell-free DNA to determine the fetal RHD genotype from the maternal circulation was first described in 1993. High throughput assays using polymerase chain reaction technology were introduced in Europe and gained widespread acceptance in the management of the Rhesus alloimmunized pregnancy. The specificity and sensitivity of these assays approached 99%. As confidence was gained with these results, Scandinavian countries began to employ cell-free DNA for fetal RHD typing as an integral component of their introduction of antenatal Rhesus immune globulin in non-alloimmunized pregnancies. Since 40% of RhD-negative pregnant women will carry an RhD-negative fetus, doses of Rhesus immune globulin were conserved. Recently 2 U.S. companies have introduced cell-free DNA assays for RHD as part of their noninvasive prenatal testing assays. Both utilize next generation sequencing and have developed methodologies to detect the aberrant RHD pseudogene and the hybrid RHD-CE-D s genotype. In addition, excellent correlation studies with either neonatal genotyping or serology have been reported. The manufacturer of RhoGAM has recently announced a national shortage. Given the current availability of reliable cell-free DNA assays for determining the RHD status of the fetus, the time has come to implement this strategy to triage the antenatal use of Rhesus immune globulin in the U.S. [ABSTRACT FROM AUTHOR]

Tapirira guianensis is a tropical plant found in South America and is widely used by indigenous communities owing to its medicinal properties. Its seeds are rich in phenolic compounds that are known for their anti-inflammatory, antioxidant, and antimicrobial properties. Despite its traditional use, there are limited scientific data on the biological activities of its seed extracts, especially in the context of antimalarial and cytoprotective effects. In this study, we investigated the chemical composition, antioxidant potential, cytotoxic effects, and antimalarial properties of hydroethanolic, ethanolic, and aqueous seed extracts. A 1:1 (v/v) water/ethanol combination efficiently extracted bioactive compounds and delivered the highest phenolic compound content. Furthermore, the hydroethanolic extracts exhibited significant biological activities, including an ability to reduce cancer-cell viability, protect against damage caused by reactive oxygen species (ROS), and decrease chromosomal aberrations, while exhibiting high efficacy against both chloroquine-sensitive and chloroquine-resistant Plasmodium falciparum strains. Hence, the use of T. guianensis seed extract as a natural source of bioactive compounds with cytoprotective, antiproliferative, antioxidant, and antimalarial properties is innovative and highlights the need for additional in vivo studies to better elucidate its mechanisms of action and safety. [ABSTRACT FROM AUTHOR]

A series of interpenetrating polymer networks (IPNs) were prepared in the film form using 2-hydroxypropyl methacrylate (HPMA) polyethylene glycol methacrylate (PEG-MA) and hydroxypropyl-chitosan (HPCH) for controlled release of 5-fluorouracil (5-FU). The prepared IPNs formulations have been characterized using Fourier transform infrared (FTIR) spectroscopy, scanning electron microscopy (SEM), swelling, and contact angle studies. In addition, the platelet adhesion, red blood cell hemolysis, and permeability to 5-FU were also studied with prepared IPNs films. The prepared p(HPMA-co-PEG–MA/HPCH)-1-6 IPNs films were loaded with different amounts of 5-FU and the drug release was studied in a continuous release system. The drug 5-FU has four amine and oxygen groups, and these functional groups interact via hydrogen bonding interaction with PEG-MA and HPCH units of the IPNs, thus, the drug was slowly released. The amount of 5-FU release from the p(HPMA-co-PEG–MA/HPCH) networks increased when the ratio of HPMA decreased or HPCH increased. The antitumor activity of 5-FU released from the prepared IPNs and remaining biological activity was measured using a human hepatocellular carcinoma cell line (SNU398). In vitro studies showed that the tested IPNs formulations were effective for the growth of the SNU398 human hepatocellular carcinoma cells. These experimental results showed that the prepared IPN films exhibited suitable physio-chemical, biocompatibility, and desired drug release profiles, thus, they could be used in various biomedical applications such as wound dressing for skin treatment. [ABSTRACT FROM AUTHOR]

Purpose: Three‐dimensional hyperpolarized 129Xe gas exchange imaging suffers from low SNR and long breath‐holds, which could be improved using compressed sensing (CS). The purpose of this work was to assess whether gas exchange ratio maps are quantitatively preserved in CS‐accelerated dissolved‐phase 129Xe imaging and to investigate the feasibility of CS‐dissolved 129Xe imaging with reduced‐cost natural abundance (NA) xenon. Methods: 129Xe gas exchange imaging was performed at 1.5 T with a multi‐echo spectroscopic imaging sequence. A CS reconstruction with an acceleration factor of 2 was compared retrospectively with conventional gridding reconstruction in a cohort of 16 healthy volunteers, 5 chronic obstructive pulmonary disease patients, and 23 patients who were hospitalized following COVID‐19 infection. Metrics of comparison included normalized mean absolute error, mean gas exchange ratio, and red blood cell (RBC) image SNR. Dissolved 129Xe CS imaging with NA xenon was assessed in 4 healthy volunteers. Results: CS reconstruction enabled acquisition time to be halved, and it reduced background noise. Median RBC SNR increased from 6 (2–18) to 11 (2–100) with CS, and there was strong agreement between CS and gridding mean ratio map values (R2 = 0.99). Image fidelity was maintained for gridding RBC SNR > 5, but below this, normalized mean absolute error increased nonlinearly with decreasing SNR. CS increased the mean SNR of NA 129Xe images 3‐fold. Conclusion: CS reconstruction of dissolved 129Xe imaging improved image quality with decreased scan time, while preserving key gas exchange metrics. This will benefit patients with breathlessness and/or low gas transfer and shows promise for NA‐dissolved 129Xe imaging. [ABSTRACT FROM AUTHOR]

Purpose: To assess the regional amplitude and phase of dissolved 129Xe red blood cell (RBC) signal oscillations in the lung vasculature with keyhole spectroscopic imaging and to compare with previous methodology, which does not account for oscillation phase. Methods: 129Xe gas transfer was measured with a four‐echo 3D radial spectroscopic imaging sequence. Keyhole reconstruction‐based RBC signal oscillation amplitude mapping was applied retrospectively to data acquired from 28 healthy volunteers, 4 chronic thromboembolic pulmonary hypertension (CTEPH) patients, and 5 patients who were hospitalized due to COVID‐19 pneumonia and had residual lung abnormalities. Using a sliding window keyhole reconstruction, maps of RBC oscillation amplitude were corrected for regional phase difference. Repeatability of the phase‐adjusted oscillation amplitude was assessed in 8 healthy volunteers across three scans. Results: With sliding window keyhole reconstruction, regional phase differences were observed in the RBC signal oscillations: mean phase = (0.27 ± 0.19) rad in healthy volunteers, (0.24 ± 0.13) rad in CTEPH patients, and (0.33 ± 0.19) rad in patients with post‐COVID‐19 residual lung abnormality. The oscillation amplitude and phase maps were more heterogeneous (i.e., they showed increased coefficient of variation) for the CTEPH patients. The RBC oscillation amplitude was repeatable, and the mean three‐scan coefficient of variation was smaller when the phase adjustment was made (0.07 ± 0.04 compared with 0.16 ± 0.05). Conclusion: Sliding window keyhole reconstruction of radial dissolved 129Xe imaging reveals regional phase differences in the RBC oscillations, which are not captured when performing two phase keyhole reconstruction. This regional phase information may reflect the hemodynamic effect of the cardiac pulse wave in the pulmonary microvasculature. [ABSTRACT FROM AUTHOR]

This study investigates the effects of seasonal variations on the erythrocyte osmotic fragility and vital parameters of donkeys Equus africanus asinus at the National Animal Production Research Institute (NAPRI) in Shika, Kaduna State, Nigeria. The research focused on two key periods: the hot-dry season (April) and the rainy season (July). Twelve donkeys were classified into three age groups: young (1–3 years), adult (4–6 years), and old (7–9 years). Blood samples were collected at six-hour intervals over a 24-hour period, while dry-bulb and wet-bulb temperatures were measured to compute the temperature-humidity index (THI). Vital parameters including rectal temperature, respiratory rate, and heart rate were also recorded. Results showed higher dry-bulb temperatures (DBT) during the hot-dry season, with the lowest DBT of 12°C at 00:00 h and the highest of 25.5°C at 18:00 h. Young donkeys exhibited the highest erythrocyte osmotic fragility during the hot-dry season, while old donkeys showed elevated fragility during the rainy season. Results also demonstrated that erythrocyte osmotic fragility varied significantly with age and season, with young donkeys exhibiting the highest fragility during the hot-dry season at a 0.3% NaCl concentration. However, old donkeys showed increased fragility during the rainy season, which shows the influence of both age and environmental conditions on erythrocyte stability. Also, rectal temperatures were higher in young donkeys during the hot-dry season compared to adults, while heart rates showed significant elevation across all age groups during the rainy season. Overall, this study elucidates the physiological adaptations of donkeys to seasonal thermal stress, providing critical insights into their health management and welfare in varying climatic conditions. Understanding these dynamics is essential for optimizing donkey husbandry practices, especially in regions facing climate variability. These findings contribute valuable knowledge to the field of veterinary physiology and highlight the necessity of tailored management strategies to mitigate the impact of seasonal stressors on animal health. [ABSTRACT FROM AUTHOR]