Hematological investigations in a case of intravascular hemolysis due to Clostridium perfringens infection.

A patient presented with fever, severe pain and edematous tight due to hip trauma and was scheduled for urgent fasciotomy. Following physical examination, laboratory analyses were requested, and results revealed anemia and severe infection. As the patient's condition was serious, a new set of samples was sent to the laboratory four hours later. Following centrifugation, severely hemolyzed dark-colored serum and plasma samples were obtained and in vitro hemolysis was suspected. The collection of samples was repeated, but a new set of samples was also hemolyzed with a significant decrease in the hemoglobin value. At that point, in vivo hemolysis was suspected, and samples were processed according to standard laboratory procedures for hemolytic samples. Following confirmation of the gas gangrene diagnosis by clinicians, the cause of hemolysis was attributed to the cytotoxic activity of α-toxin produced by the anaerobic gram-positive bacterium Clostridium perfringens. An insight into the laboratory procedure that could help to narrow down the causes of hemolysis and single out C. perfringens as a cause of intravascular hemolysis was given.

Bacillus velezensis iturins inhibit the hemolytic activity of Staphylococcus aureus.

Bovine mastitis caused by S. aureus has a major economic impact on the dairy sector. With the crucial need for new therapies, anti-virulence strategies have gained attention as alternatives to antibiotics. Here we aimed to identify novel compounds that inhibit the production/activity of hemolysins, a virulence factor of S. aureus associated with mastitis severity. We screened Bacillus strains obtained from diverse sources for compounds showing anti-hemolytic activity. Our results demonstrate that lipopeptides produced by Bacillus spp. completely prevented the hemolytic activity of S. aureus at certain concentrations. Following purification, both iturins, fengycins, and surfactins were able to reduce hemolysis caused by S. aureus, with iturins showing the highest anti-hemolytic activity (up to 76% reduction). The lipopeptides showed an effect at the post-translational level. Molecular docking simulations demonstrated that these compounds can bind to hemolysin, possibly interfering with enzyme action. Lastly, molecular dynamics analysis indicated general stability of important residues for hemolysin activity as well as the presence of hydrogen bonds between iturins and these residues, with longevous interactions. Our data reveals, for the first time, an anti-hemolytic activity of lipopeptides and highlights the potential application of iturins as an anti-virulence therapy to control bovine mastitis caused by S. aureus.

Characterization of Three Polysaccharide-Based Hydrogels Derived from Laminaria japonica and Their Hemostatic Properties.

Three Laminaria japonica polysaccharides (LJPs) extracted via water extraction (LJP-W), acid extraction (LJP-A), and enzymatic extraction (LJP-E) were used as raw materials to be cross-linked with chitosan and polyvinyl alcohol to prepare hydrogels. Compared with conventional hydrogel systems, all three types of LJP-based polysaccharide hydrogels exhibited better swelling properties (14 times their original weight) and the absorption ability of simulated body fluid (first 2 h: 6-10%). They also demonstrated better rigidity and mechanical strength. Young's modulus of LJP-E was 4 times that of the blank. In terms of hemostatic properties, all three polysaccharide hydrogels did not show significant cytotoxic and hemolytic properties. The enzyme- and acid-extracted hydrogels (LJP-Gel-A and LJP-Gel-E) demonstrated better whole-blood coagulant ability compared with the water-extracted hydrogel (LJP-Gel-W), as evidenced by the whole blood coagulation index being half that of LJP-Gel-W. Additionally, the lactate dehydrogenase viabilities of LJP-Gel-A and LJP-Gel-E were significantly higher, at about four and three times those of water extraction, respectively. The above results suggested that LJP-Gel-A and LJP-Gel-E exhibited better blood coagulation capabilities than LJP-Gel-W, due to their enhanced platelet enrichment and adhesion properties. Consequently, these hydrogels are more conducive to promoting coagulation and have good potential for wound hemostasis.

Comparison of blood profiles between housed and grazing Korean indigenous cattle (Hanwoo).

The objective of this study was to compare the hematology profiles of Korean indigenous cattle (Hanwoo) raised in a barn (housed) or on pasture (grazing). Our findings showed significant differences in the red blood cell (RBC) profiles of these 2 groups. When compared to cattle raised in a barn, a significant decrease in hematocrit (P = 0.000), hemoglobin (P = 0.000), and red blood cells (RBCs) (P = 0.000) and a significant increase in mean cell volume (P = 0.015) and reticulocytes (P = 0.000) were observed in grazing cattle, which indicate regenerative anemia. Furthermore, indirect bilirubin was significantly higher in grazing cattle, which indicates intravascular hemolysis and neutropenia (P = 0.000), and monocytosis (P = 0.000) was also identified. To the best of our knowledge, this is the first study that demonstrates changes in reticulocyte count and indirect bilirubin levels secondary to regenerative intravascular hemolysis in grazing cattle.

L'objectif de cette étude était de comparer les profils hématologiques de bovins coréens indigènes (Hanwoo) gardés dans une étable ou au pâturage. Nos résultats ont montré des différences significatives dans les profils des globules rouges de ces 2 groupes. Lorsque comparé aux bovins gardés dans l'étable, une réduction significative de l'hématocrite (P = 0,000), de l'hémoglobine (P = 0,000), et des globules rouges (P = 0,000) et une augmentation significative du volume cellulaire moyen (P = 0,015) et des réticulocytes (P = 0,000) ont été observées chez les bovins au pâturage, ce qui indique une anémie régénératrice. Également, la bilirubine indirecte était significativement plus élevée chez les bovins au pâturage, indicatif d'une hémolyse intravasculaire, et une neutropénie (P = 0,000) et une monocytose (P = 0,000) furent également identifiées. Au meilleur de nos connaissances, ceci est la première étude qui démontre des changements dans le dénombrement des réticulocytes et les niveaux de bilirubine indirecte secondaires à une hémolyse intravasculaire régénérative chez des bovins au pâturage.(Traduit par Docteur Serge Messier).

[Expert consensus on clonal screening and monitoring of complement inhibitor therapy in paroxysmal nocturnal hemoglobinuria (2024)].

Paroxysmal nocturnal hemoglobinuria (PNH) is a rare clonal disease with abnormal hematopoietic stem cells that causes intravascular hemolytic anemia, thrombosis, and peripheral blood cytopenia. It has a chronic progressive course and can be fatal in severe cases if not treated aggressively. Complement inhibitors are the first-line recommended treatment for hemolysis-related symptoms of PNH. With the rapid development of new complement inhibitors, it is critical to quickly screen and confirm the diagnosis, identify patients with complement inhibitor indications, and monitor breakthrough hemolysis and extravascular hemolysis during complement inhibitor therapy. Drawing on the most recent guidelines, works of literature, and meta-reviews from around the world, as well as combining with experience from the experts, this consensus focused on PNH screening principles, the significance of PNH cloning detection, and post-treatment monitoring of terminal complement inhibitors, which may contribute to a better understanding of diagnosis and treatment monitoring in the era of complement inhibitors.

[Eculizumab in patients with paroxysmal nocturnal hemoglobinuria: a real-world study in China].

Objective: To evaluate the efficacy and safety of eculizumab in the treatment of paroxysmal nocturnal hemoglobinuria (PNH) in China. Methods: Data from PNH patients who received at least 3 months of full-dose eculizumab and were followed for at least 3 months between December 2022 and July 2023 were retrospectively collected. We evaluated changes in clinical and laboratory parameters after 1, 2, 3, and 6 months of eculizumab treatment. The rates of breakthrough hemolysis (BTH), extravascular hemolysis (EVH), and the occurrence of adverse reactions were also monitored. Results: The study included nine patients, six males and three females, with a median age of 54 (28-69) years. 5 of the patients had classic PNH, while 4 had PNH/AA. The number of episodes of hemoglobinuria was 5 (1-25) per month before eculizumab. 4 patients required blood transfusion, 5 had thrombosis and one had renal impairment before eculizumab. The median time to eculizumab was 6 (3-7) months and the followup period was 3 (3-6) months after treatment. The number of episodes of hemoglobinuria following eculizumab was 0 (0-1). During the followup period, no additional thrombotic events occurred. LDH at any time after eculizumab was lower than at baseline, and some patients' HGB increased. All transfused patients became transfusion-independent after receiving eculizumab. The FACIT-Fatigue score improved by an average of 17.3 points following treatment. 2 patients developed BTH and improved with symptomatic treatment. There were three adverse events that caused mild symptoms. There are no serious adverse events or deaths. Conclusion: Eculizumab can effectively control the hemolytic-related symptoms of PNH in China, reducing the need for blood transfusions to some extent, while also demonstrating a higher safety profile.

Metahemoglobinemia y hemólisis intravascular aguda después de una intoxicación por naftaleno en un paciente pediátrico / Methemoglobinemia and acute intravascular hemolysis after naphthalene poisoning in a pediatric patient

La intoxicación por naftaleno es poco frecuente en los niños. Es causada por la ingesta, la inhalación o el contacto con la piel de sustancias que contienen naftaleno. Los pacientes suelen tener orina de color marrón oscuro, diarrea acuosa y vómito bilioso. Los signos incluyen fiebre, taquicardia, hipotensión y valores bajos en la oximetría de pulso, incluso con oxigenoterapia. Los análisis de sangre detectan anemia hemolítica, metahemoglobinemia, insuficiencia renal e hiperbilirrubinemia. Además del tratamiento sintomático, se hacen transfusiones de eritrocitos y se les administran ácido ascórbico, azul de metileno y N-acetilcisteína. En este artículo, presentamos el caso de un paciente masculino de 23 meses de edad con metahemoglobinemia y hemólisis intravascular aguda que recibió atención en la unidad de cuidados intensivos durante cinco días por intoxicación por naftaleno. Si bien la intoxicación por naftaleno es muy poco frecuente, tiene consecuencias mortales y se debe ejercer precaución con su uso y venta.

Poisoning by naphthalene is uncommon in children. It is a type of poisoning brought on by ingesting, inhaling, or coming into touch with naphthalene-containing substances on the skin. Patients typically present with an initial onset of dark brown urine, watery diarrhea, and bile vomit. The signs include fever, tachycardia, hypotension, and low pulse oximetry readings even with oxygen support. Hemolytic anemia, methemoglobinemia, renal failure, and hyperbilirubinemia are all detected in blood tests. Erythrocyte transfusion, ascorbic acid, methylene blue, and N-acetylcysteine (NAC) therapies are provided to inpatients in addition to symptomatic treatment. We present a 23-month-old male patient who developed methemoglobinemia and acute intravascular hemolysis, who was followed up in the intensive care unit for five days due to naphthalene intoxication. Although naphthalene poisoning is very rare, it should be known that it has fatal consequences, and more care should be taken in its use and sale.

Passenger lymphocyte syndrome following minor ABO-mismatched liver transplantation.

Passenger lymphocyte syndrome is an immunologic disorder observed in solid organ and haematopoietic stem cell transplantation in which B lymphocytes within a donor graft are transferred to the recipient and subsequently produce circulating antibodies against host red blood cell antigens. The syndrome is most likely to occur in minor ABO blood group mismatched or Rh incompatible transplantation. Although generally mild and self-limited, the resulting haemolytic burden has the potential to increase the risk of infection, graft failure and death. The phenomenon is observed in the transplantation of any solid organ with lymphoid tissue, including the liver. We present a structured case report of passenger lymphocyte syndrome following minor ABO-mismatched liver transplantation, which was initially complicated by blood loss anaemia early in the postoperative period. By reviewing the limited literature of this disorder following liver transplantation, we emphasise common clinical findings and treatment strategies as well as introduce chimerism analysis to confirm resolution.

COMPARING THE EFFECTS OF DIPOTASSIUM ETHYLENEDIAMINETETRAACETIC ACID AND LITHIUM HEPARIN ON HEMATOLOGIC VALUES IN BLANDING'S TURTLES (EMYDOIDEA BLANDINGII), PAINTED TURTLES (CHRYSEMYS PICTA), AND COMMON SNAPPING TURTLES (CHELYDRA SERPENTINA).

Hematology is a routine component of clinical management in veterinary patients. Anticoagulant choice can profoundly influence morphologic assessment of erythrocytes, leukocytes, thrombocytes, and their subsequent quantification. Previous chelonian studies suggest that lithium heparin (LH) is a superior anticoagulant due to hemolysis resulting from dipotassium ethylenediaminetetraacetic acid (dEDTA) in some species. The aim of this study was to compare the effects of dEDTA and LH on hematologic values in Blanding's turtles (Emydoidea blandingii, n = 35), painted turtles (Chrysemys picta, n = 34), and common snapping turtles (Chelydra serpentina, n = 36). We collected samples from free-ranging turtles and immediately divided whole blood into LH and dEDTA tubes. Packed cell volume, total solids, erythrocyte sedimentation rate, white blood cell counts, and differential leukocyte counts were determined. Hemolysis was observed macro- and microscopically in dEDTA samples from painted turtles and common snapping turtles. Packed cell volume and heterophil:lymphocyte was lower and erythrocyte sedimentation rate was higher in LH samples from painted turtles (p, 0.05). In snapping turtles, the PCV, number of monocytes, and number of eosinophils was lower in LH samples (p, 0.05). In Blanding's turtles, the number of eosinophils and basophils was higher in LH samples, while heterophil counts were lower (p, 0.05). Anticoagulant choice created constant and proportional bias for multiple analytes in a species-dependent fashion. LH is the recommended anticoagulant for hematology in painted turtles and common snapping turtles. Either LH or dEDTA may be used in Blanding's turtles, though anticoagulant-specific reference intervals may be necessary.

Red Blood Cell Storage with Xenon: Safe or Disruption?

Xenon, an inert gas commonly used in medicine, has been considered as a potential option for prolonged preservation of donor packed red blood cells (pRBCs) under hypoxic conditions. This study aimed to investigate how xenon affects erythrocyte parameters under prolonged storage. In vitro model experiments were performed using two methods to create hypoxic conditions. In the first method, xenon was introduced into bags of pRBCs which were then stored for 42 days, while in the second method, xenon was added to samples in glass tubes. The results of our experiment showed that the presence of xenon resulted in notable alterations in erythrocyte morphology, similar to those observed under standard storage conditions. For pRBC bags, hemolysis during storage with xenon exceeded the acceptable limit by a factor of six, whereas the closed-glass-tube experiment showed minimal hemolysis in samples exposed to xenon. Notably, the production of deoxyhemoglobin was specific to xenon exposure in both cell suspension and hemolysate. However, this study did not provide evidence for the purported protective properties of xenon.

Development of pH-Sensitive Nanoparticle Incorporated into Dissolving Microarray Patch for Selective Delivery of Methotrexate.

PURPOSE: Rheumatoid arthritis (RA) is a systemic autoimmune disease that attacks human joints. Methotrexate (MTX), as one the most effective medications to treat RA, has limitations when administered either orally or by injection. To overcome this limitation, we formulated MTX through a smart nanoparticle (SNP) combined with dissolving microarray patch (DMAP) to achieve selective-targeted delivery of RA. METHODS: SNP was made using the combination of polyethylene glycol (PEG) and polycaprolactone (PCL) polymers, while DMAP was made using the combination of hyaluronic acid and polyvinylpyrrolidone K-30. SNP-DMAP was then evaluated for its mechanical and chemical characteristics, ex vivo permeation test, in vivo pharmacokinetic study, hemolysis, and hen's egg test-chorioallantoic membrane (HET-CAM) test. RESULT: The results showed that the characteristics of the SNP-DMAP-MTX formulas meet the requirements for transdermal delivery, with the particle size of 189.09 ±12.30 nm and absorption efficiency of 65.40 ± 5.0%. The hemolysis and HET-CAM testing indicate that this formula was non-toxic and non-irritating. Ex vivo permeation shows a concentration of 51.50 ± 3.20 µg/mL of SNP-DMAP-MTX in PBS pH 5.0. The pharmacokinetic profile of SNP-DMAP-MTX showed selectivity and sustained release compared with oral and DMAP-MTX with values of t1/2 (4.88 ± 0 h), Tmax (8 ± 0 h), Cmax (0.50 ± 0.04 µg/mL), AUC (3.15 ± 0.54 µg/mL.h), and mean residence time (MRT) (9.13 ± 0 h). CONCLUSION: The developed SNP-DMAP-MTX has been proven to deliver MTX transdermal and selectively at the RA site, potentially avoiding conventional MTX side effects and enhancing the effectiveness of RA therapy.

Phosphatase-degradable nanoparticles providing sustained drug release.

AIM: The study aimed to develop enzyme-degradable nanoparticles comprising polyphosphates and metal cations providing sustained release of the antibacterial drug ethacridine (ETH). METHODS: Calcium polyphosphate (Ca-PP), zinc polyphosphate (Zn-PP) and iron polyphosphate nanoparticles (Fe-PP NPs) were prepared by co-precipitation of sodium polyphosphate with cations and ETH. Developed nanocarriers were characterized regarding particle size, PDI, zeta potential, encapsulation efficiency and drug loading. Toxicological profile of nanocarriers was assessed via hemolysis assay and cell viability on human blood erythrocytes and HEK-293 cells, respectively. The enzymatic degradation of NPs was evaluated in presence of alkaline phosphatase (ALP) monitoring the release of monophosphate, shift in zeta potential and particle size as well as drug release. The antibacterial efficacy against Escherichia coli was determined via microdilution assay. RESULTS: NPs were obtained in a size range between 300 - 480 nm displaying negative zeta potential values. Encapsulation efficiency was in the range of 83.73 %- 95.99 %. Hemolysis assay underlined sufficient compatibility of NPs with blood cells, whereas drug and NPs showed a concentration dependent effect on HEK-293 cells viability. Ca- and Zn-PP NPs exhibited remarkable changes in zeta potential, particle size, monophosphate and drug release upon incubation with ALP, compared to Fe-PP NPs showing only minor differences. The released ETH from Ca- and Zn-PP nanocarriers retained the antibacterial activity against E. coli, whereas no antibacterial effect was observed with Fe-PP NPs. CONCLUSION: Polyphosphate nanoparticles cross-linked with divalent cations and ETH hold promise for sustained drug delivery triggered by ALP for parental administration.

Pediatric hemolysis in emergency departments: Prevalence, risk factors, and clinical implications.

OBJECTIVE: This study aimed to analyze the prevalence, risk factors, and clinical implications of hemolyzed laboratory samples in the pediatric emergency department (ED), a subject on which existing data remains scarce. METHODS: We conducted a multi-site observational cohort analysis of pediatric ED encounters in Metro Detroit, Michigan, United States. The study included participants below 18 years of age who had undergone peripheral intravenous catheter (PIVC) placement and laboratory testing. The primary outcome was the presence of hemolysis, and secondary outcomes included identifying risk factors for hemolysis and assessing the impact of hemolysis on PIVC failure. RESULTS: Between January 2021 and May 2022, 10,462 ED encounters met inclusion criteria, of which 14.0% showed laboratory evidence of hemolysis. The highest proportion of hemolysis occurred in the infant (age 0-1) population (20.1%). Multivariable regression analysis indicated higher odds of hemolysis for PIVCs placed in the hand/wrist in the toddler (age 2-5) and child (age 6-11) subgroups. PIVCs placed in the hand/wrist also demonstrated higher odds of failure in infants. CONCLUSIONS: Hemolysis in the pediatric ED population is a frequent complication that occurs at similar rates as in adults. PIVCs placed in the hand/wrist were associated with higher odds of hemolysis compared to those placed in the antecubital fossa. Clinicians should consider alternative locations for PIVC placement if clinically appropriate. Further research is needed to better understand the clinical implications of pediatric hemolysis.

Clinical implications of inaccurate potassium determination in hemolyzed pediatric blood specimens.

BACKGROUND: Analysis of whole blood specimens is rapid and saves blood, but hemolysis may go undetected and compromise the accuracy of potassium measurement. We aimed to define the frequency and magnitude of error in whole blood potassium measurement. METHODS: 34 months of whole blood and plasma potassium data were extracted from patients aged less than 2 years at the time of sample acquisition. Hemolysis was detected using the plasma "H index." The magnitude of potassium bias was estimated from the difference between paired whole blood and plasma measurement separated by less than 2 h. RESULTS: 56,000 of the 105,000 data points were from plasma and 20 % of these had significant hemolysis. Rates of hemolysis (nearing 50 %) were greatest in the neonatal nursery. Of 662 proximal whole blood and plasma paired results, 8 % had elevated whole blood potassium with a normal plasma value and 4 % had a normal whole blood potassium with reduced plasma potassium. The bias between whole blood and plasma potassium ranged from -1.0 to 4.0 mmol/L. CONCLUSIONS: The use of whole blood analysis brings with it significant risk for error in potassium measurement. Better tools to detect hemolysis in these types of specimens are indicated.

Dissociation Phenomenon of Erythrocyte Agglutination and Its Application to Assay of Functional Activity of the Complement System in Clinical Laboratory.

OBJECTIVE: The objective of the study was to validate the dissociation phenomenon of erythrocyte agglutination which is based on erythrocyte fragments and to apply it in the functional activity assay of the complement system. METHODS: The dissociation-agglutination effect of erythrocyte fragments was validated by detecting the number of free erythrocytes after the action of erythrocyte fragments on agglutinated erythrocytes. The number of free erythrocytes produced after hemolysis of agglutinated erythrocytes caused by complements and complement activators(CAs) was detected by auto hematology analyzer and the results were indicated by mean hemoglobin concentration of erythrocytes (MCHC). We optimized the test conditions and validated the inter-batch stability, explored the resolution of the assay method, and assayed for the total complement activity (AC) and the CAs activated complement activity (ACA) in serum from patients and healthy individual groups. RESULTS: Erythrocyte fragments have a dissociative effect on agglutinated erythrocytes. The auto hematology analyzer was able to detect AC and ACA, where AC showed an inverse correlation with MCHC, and ACA demonstrated a positive correlation with MCHC. The inter-batch CV of AC, ACA, and ACA/AC was found to be 5%, 9%, and 11.7%, respectively, with good stability. The study found that serum samples from acute phase reaction patients showed significant differences in ACA compared with healthy individuals, with a p value of 0.018; serum samples from patients with nephrotic syndrome showed significant differences in AC, ACA, and ACA/AC compared with healthy individuals, with p values of 0.014, 0.002, and 0.041, respectively. CONCLUSION: Erythrocyte fragments have dissociation-agglutination effect. The complement system immunological functional detection method, based on this effect, has potential clinical application value due to its sensitivity and accuracy.

Cationicity Enhancement on the Hydrophilic Face of Ctriporin Significantly Reduces Its Hemolytic Activity and Improves the Antimicrobial Activity against Antibiotic-Resistant ESKAPE Pathogens.

The ESKAPE pathogen-associated antimicrobial resistance is a global public health issue, and novel therapeutic strategies are urgently needed. The short cationic antimicrobial peptide (AMP) family represents an important subfamily of scorpion-derived AMPs, but high hemolysis and poor antimicrobial activity hinder their therapeutic application. Here, we recomposed the hydrophilic face of Ctriporin through lysine substitution. We observed non-linear correlations between the physiochemical properties of the peptides and their activities, and significant deviations regarding the changes of antimicrobial activities against different bacterial species, as well as hemolytic activity. Most importantly, we obtained two Ctriporin analogs, CM5 and CM6, these two have significantly reduced hemolytic activity and more potent antimicrobial activities against all tested antibiotic-resistant ESKAPE pathogens. Fluorescence experiments indicated they may perform the bactericidal function through a membrane-lytic action model. Our work sheds light on the potential of CM5 and CM6 in developing novel antimicrobials and gives clues for optimizing peptides from the short cationic AMP family.

Antimicrobial Indole-3-Carboxamido-Polyamine Conjugates Target Bacterial Membranes and Are Antibiotic Potentiators.

Small molecules that can restore the action of legacy antibiotics toward drug-resistant bacteria represent an area of ongoing research interest. We have previously reported indole-3-glyoxylamido and indole-3-acetamido-polyamine conjugates that exhibit intrinsic activity toward bacterial and fungal species, and the ability to enhance the action of doxycycline toward the Gram-negative bacteria Pseudomonas aeruginosa; however, these desirable activities were commonly associated with unfavorable cytotoxicity and/or red blood cell hemolytic properties. In this paper, we report the synthesis and biological investigation of a new class of α,ω-di(indole-3-carboxamido)polyamine derivatives, leading to the identification of several analogues that exhibit antimicrobial- and antibiotic-potentiating activities without detectable cytotoxic or hemolytic properties. 5-Bromo-substituted indole analogues 3 and 12-18 were generally more broad-spectrum in their activity than others in the set, with 13b (polyamine PA-3-6-3) being particularly notable for its anti-Staphylococcus aureus, Acinetobacter baumannii, and Cryptococcus neoformans activities (MIC ≤ 0.28 µM). The same analogue also restored the action of doxycycline toward P. aeruginosa with a 21-fold enhancement, while the corresponding 5-bromo-indole-3-carboxamide-PA3-7-3 analogue was able to enhance the action of both doxycycline and erythromycin toward P. aeruginosa and Escherichia coli, respectively. The analogue 13b was capable of disrupting the bacterial membrane of both S. aureus and methicillin-resistant S. aureus (MRSA) and the outer membrane of P. aeruginosa, suggesting that membrane perturbation could be a mechanism of action of both intrinsic antimicrobial activities and antibiotic potentiation.

Acalypha indica induced acute oxidative haemolysis and methaemoglobinaemia: two case reports.

BACKGROUND: Herbal products and traditional remedies are commonly used by individuals worldwide for the management of common ailments, even though most are not without risks. Acalypha indica is a popular medicinal plant consumed in some Asian countries. CASE PRESENTATION: This case report presents a 40-year-old previously unevaluated Sri Lankan female and her 8-year-old son who presented with severe glucose-6-phosphate dehydrogenase (G6PD) deficiency related acute intravascular oxidative haemolysis and methaemoglobinaemia precipitated by Acalypha indica consumption, successfully managed with supportive care and blood transfusion. CONCLUSIONS: This case highlights the potential hemolytic and methaemoglobinaemic effects of ingesting oxidant herbal products and the importance of considering such exposures in patients presenting with hemolysis and multiorgan involvement, particularly in communities where herbal product intake is popular. Healthcare providers should be aware of the risks associated with traditional remedies and maintain a high index of suspicion to ensure prompt recognition and appropriate management.

Hematin- and Hemin-Induced Spherization and Hemolysis of Human Erythrocytes Are Independent of Extracellular Calcium Concentration.

Pathologies such as malaria, hemorrhagic stroke, sickle cell disease, and thalassemia are characterized by the release of hemoglobin degradation products from damaged RBCs. Hematin (liganded with OH-) and hemin (liganded with Cl-)-are the oxidized forms of heme with toxic properties due to their hydrophobicity and the presence of redox-active Fe3. In the present study, using the original LaSca-TM laser particle analyzer, flow cytometry, and confocal microscopy, we showed that both hematin and hemin induce dose-dependent RBC spherization and hemolysis with ghost formation. Hematin and hemin at nanomolar concentrations increased [Ca2+]i in RBC; however, spherization and hemolysis occurred in the presence and absence of calcium, indicating that both processes are independent of [Ca2+]i. Both compounds triggered acute phosphatidylserine exposure on the membrane surface, reversible after 60 min of incubation. A comparison of hematin and hemin effects on RBCs revealed that hematin is a more reactive toxic metabolite than hemin towards human RBCs. The toxic effects of heme derivatives were reduced and even reversed in the presence of albumin, indicating the presence in RBCs of the own recovery system against the toxic effects of heme derivatives.